diff --git a/-J_xL4IGhJA.txt b/-J_xL4IGhJA.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1f839b9a9ceb37d02bb4b1ec0a7f51c0cc6444b --- /dev/null +++ b/-J_xL4IGhJA.txt @@ -0,0 +1,10995 @@ +align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +I'd like to welcome you to this course + + align:start position:0% +I'd like to welcome you to this course + + + align:start position:0% +I'd like to welcome you to this course +on computer science actually that's a + + align:start position:0% +on computer science actually that's a + + + align:start position:0% +on computer science actually that's a +terrible way to start computer science + + align:start position:0% +terrible way to start computer science + + + align:start position:0% +terrible way to start computer science +is a terrible name for this business + + align:start position:0% +is a terrible name for this business + + + align:start position:0% +is a terrible name for this business +first of all it's not a science it uh + + align:start position:0% +first of all it's not a science it uh + + + align:start position:0% +first of all it's not a science it uh +might be engineering or it might be art + + align:start position:0% +might be engineering or it might be art + + + align:start position:0% +might be engineering or it might be art +well we'll actually see that computer + + align:start position:0% +well we'll actually see that computer + + + align:start position:0% +well we'll actually see that computer +so-called science actually has a lot in + + align:start position:0% +so-called science actually has a lot in + + + align:start position:0% +so-called science actually has a lot in +common with magic you'll see that in + + align:start position:0% +common with magic you'll see that in + + + align:start position:0% +common with magic you'll see that in +this course so it's not a science it's + + align:start position:0% +this course so it's not a science it's + + + align:start position:0% +this course so it's not a science it's +also not really very much about + + align:start position:0% +also not really very much about + + + align:start position:0% +also not really very much about +computers and it's not about computers + + align:start position:0% +computers and it's not about computers + + + align:start position:0% +computers and it's not about computers +in the same sense that that physics is + + align:start position:0% +in the same sense that that physics is + + + align:start position:0% +in the same sense that that physics is +not really about particle accelerators + + align:start position:0% +not really about particle accelerators + + + align:start position:0% +not really about particle accelerators +and biology is not really about + + align:start position:0% +and biology is not really about + + + align:start position:0% +and biology is not really about +microscopes and petri dishes and it's + + align:start position:0% +microscopes and petri dishes and it's + + + align:start position:0% +microscopes and petri dishes and it's +not about computers in the same set + + align:start position:0% +not about computers in the same set + + + align:start position:0% +not about computers in the same set +sense that geometry is not really about + + align:start position:0% +sense that geometry is not really about + + + align:start position:0% +sense that geometry is not really about +using surveying instruments in fact + + align:start position:0% +using surveying instruments in fact + + + align:start position:0% +using surveying instruments in fact +there's a lot of commonality between + + align:start position:0% +there's a lot of commonality between + + + align:start position:0% +there's a lot of commonality between +computer science and geometry geometry + + align:start position:0% +computer science and geometry geometry + + + align:start position:0% +computer science and geometry geometry +first of all is another subject with a + + align:start position:0% +first of all is another subject with a + + + align:start position:0% +first of all is another subject with a +lousy name the name comes from Gaia + + align:start position:0% +lousy name the name comes from Gaia + + + align:start position:0% +lousy name the name comes from Gaia +meaning the earth and Metron meaning to + + align:start position:0% +meaning the earth and Metron meaning to + + + align:start position:0% +meaning the earth and Metron meaning to +measure geometry originally meant + + align:start position:0% +measure geometry originally meant + + + align:start position:0% +measure geometry originally meant +measuring the earth were or surveying + + align:start position:0% +measuring the earth were or surveying + + + align:start position:0% +measuring the earth were or surveying +and the reason for that was that + + align:start position:0% +and the reason for that was that + + + align:start position:0% +and the reason for that was that +thousands of years ago the Egyptian + + align:start position:0% +thousands of years ago the Egyptian + + + align:start position:0% +thousands of years ago the Egyptian +priesthood + + align:start position:0% +priesthood + + + align:start position:0% +priesthood +developed the rudiments of geometry in + + align:start position:0% +developed the rudiments of geometry in + + + align:start position:0% +developed the rudiments of geometry in +order to figure out how to restore the + + align:start position:0% +order to figure out how to restore the + + + align:start position:0% +order to figure out how to restore the +boundaries of fields that were destroyed + + align:start position:0% +boundaries of fields that were destroyed + + + align:start position:0% +boundaries of fields that were destroyed +in the annual flooding of the Nile to + + align:start position:0% +in the annual flooding of the Nile to + + + align:start position:0% +in the annual flooding of the Nile to +the Egyptians who did that geometry + + align:start position:0% +the Egyptians who did that geometry + + + align:start position:0% +the Egyptians who did that geometry +really was the use of surveying + + align:start position:0% +really was the use of surveying + + + align:start position:0% +really was the use of surveying +instruments now the reason that we think + + align:start position:0% +instruments now the reason that we think + + + align:start position:0% +instruments now the reason that we think +computer science is about computers is + + align:start position:0% +computer science is about computers is + + + align:start position:0% +computer science is about computers is +pretty much the same reason that the + + align:start position:0% +pretty much the same reason that the + + + align:start position:0% +pretty much the same reason that the +Egyptians thought geometry was about + + align:start position:0% +Egyptians thought geometry was about + + + align:start position:0% +Egyptians thought geometry was about +surveying instruments and that is when + + align:start position:0% +surveying instruments and that is when + + + align:start position:0% +surveying instruments and that is when +some field is just getting started and + + align:start position:0% +some field is just getting started and + + + align:start position:0% +some field is just getting started and +you don't really understand it very well + + align:start position:0% +you don't really understand it very well + + + align:start position:0% +you don't really understand it very well +it's very easy to confuse the essence of + + align:start position:0% +it's very easy to confuse the essence of + + + align:start position:0% +it's very easy to confuse the essence of +what you're doing with the tools that + + align:start position:0% +what you're doing with the tools that + + + align:start position:0% +what you're doing with the tools that +you use and indeed on some absolute + + align:start position:0% +you use and indeed on some absolute + + + align:start position:0% +you use and indeed on some absolute +scale of things we probably know less + + align:start position:0% +scale of things we probably know less + + + align:start position:0% +scale of things we probably know less +about the essence of computer science + + align:start position:0% +about the essence of computer science + + + align:start position:0% +about the essence of computer science +than the ancient Egyptians really knew + + align:start position:0% +than the ancient Egyptians really knew + + + align:start position:0% +than the ancient Egyptians really knew +about genomics + + align:start position:0% + + + + align:start position:0% + +well what's what I mean by the essence + + align:start position:0% +well what's what I mean by the essence + + + align:start position:0% +well what's what I mean by the essence +of computer science what I mean by the + + align:start position:0% +of computer science what I mean by the + + + align:start position:0% +of computer science what I mean by the +essence of geometry see it's certainly + + align:start position:0% +essence of geometry see it's certainly + + + align:start position:0% +essence of geometry see it's certainly +true that these Egyptians went off and + + align:start position:0% +true that these Egyptians went off and + + + align:start position:0% +true that these Egyptians went off and +used surveying instruments but when we + + align:start position:0% +used surveying instruments but when we + + + align:start position:0% +used surveying instruments but when we +look back on them after a couple of + + align:start position:0% +look back on them after a couple of + + + align:start position:0% +look back on them after a couple of +thousand years we say gee what they were + + align:start position:0% +thousand years we say gee what they were + + + align:start position:0% +thousand years we say gee what they were +doing the important stuff they were + + align:start position:0% +doing the important stuff they were + + + align:start position:0% +doing the important stuff they were +doing was to begin to formalize notions + + align:start position:0% +doing was to begin to formalize notions + + + align:start position:0% +doing was to begin to formalize notions +about space and time to start a way of + + align:start position:0% +about space and time to start a way of + + + align:start position:0% +about space and time to start a way of +talking about mathematical truths + + align:start position:0% +talking about mathematical truths + + + align:start position:0% +talking about mathematical truths +formally that led to the axiomatic + + align:start position:0% +formally that led to the axiomatic + + + align:start position:0% +formally that led to the axiomatic +method that led to serve all of modern + + align:start position:0% +method that led to serve all of modern + + + align:start position:0% +method that led to serve all of modern +mathematics figuring out a way to talk + + align:start position:0% +mathematics figuring out a way to talk + + + align:start position:0% +mathematics figuring out a way to talk +precisely about so-called declarative + + align:start position:0% +precisely about so-called declarative + + + align:start position:0% +precisely about so-called declarative +knowledge what is true well similarly + + align:start position:0% +knowledge what is true well similarly + + + align:start position:0% +knowledge what is true well similarly +think in the future people will look + + align:start position:0% +think in the future people will look + + + align:start position:0% +think in the future people will look +back and say yes those those primitives + + align:start position:0% +back and say yes those those primitives + + + align:start position:0% +back and say yes those those primitives +in the 20th century we're fiddling + + align:start position:0% +in the 20th century we're fiddling + + + align:start position:0% +in the 20th century we're fiddling +around with these gadgets called + + align:start position:0% +around with these gadgets called + + + align:start position:0% +around with these gadgets called +computers but really what they were + + align:start position:0% +computers but really what they were + + + align:start position:0% +computers but really what they were +doing is starting to learn how to + + align:start position:0% +doing is starting to learn how to + + + align:start position:0% +doing is starting to learn how to +formalize formalize intuitions about + + align:start position:0% +formalize formalize intuitions about + + + align:start position:0% +formalize formalize intuitions about +process how to do things starting to to + + align:start position:0% +process how to do things starting to to + + + align:start position:0% +process how to do things starting to to +develop a way to talk precisely about + + align:start position:0% +develop a way to talk precisely about + + + align:start position:0% +develop a way to talk precisely about +about how to knowledge as opposed to + + align:start position:0% +about how to knowledge as opposed to + + + align:start position:0% +about how to knowledge as opposed to +geometry that talks about what is true + + align:start position:0% +geometry that talks about what is true + + + align:start position:0% +geometry that talks about what is true +we give you an example of that + + align:start position:0% + + + + align:start position:0% + +take a look here is a piece of a piece + + align:start position:0% +take a look here is a piece of a piece + + + align:start position:0% +take a look here is a piece of a piece +of mathematics right that says what a + + align:start position:0% +of mathematics right that says what a + + + align:start position:0% +of mathematics right that says what a +square root is and if the square root of + + align:start position:0% +square root is and if the square root of + + + align:start position:0% +square root is and if the square root of +the x is the number Y such that Y + + align:start position:0% +the x is the number Y such that Y + + + align:start position:0% +the x is the number Y such that Y +squared is equal to x and Y is greater + + align:start position:0% +squared is equal to x and Y is greater + + + align:start position:0% +squared is equal to x and Y is greater +than zero now that's a fine piece of + + align:start position:0% +than zero now that's a fine piece of + + + align:start position:0% +than zero now that's a fine piece of +mathematics but just telling you what a + + align:start position:0% +mathematics but just telling you what a + + + align:start position:0% +mathematics but just telling you what a +square root is doesn't really say + + align:start position:0% +square root is doesn't really say + + + align:start position:0% +square root is doesn't really say +anything about about how you might go + + align:start position:0% +anything about about how you might go + + + align:start position:0% +anything about about how you might go +out and find one right so let's contrast + + align:start position:0% +out and find one right so let's contrast + + + align:start position:0% +out and find one right so let's contrast +that with a piece of imperative + + align:start position:0% +that with a piece of imperative + + + align:start position:0% +that with a piece of imperative +knowledge right how you might go out and + + align:start position:0% +knowledge right how you might go out and + + + align:start position:0% +knowledge right how you might go out and +find a square root this in fact also + + align:start position:0% +find a square root this in fact also + + + align:start position:0% +find a square root this in fact also +comes from Egypt not not a not ancient + + align:start position:0% +comes from Egypt not not a not ancient + + + align:start position:0% +comes from Egypt not not a not ancient +ancient Egypt this isn't an algorithm + + align:start position:0% +ancient Egypt this isn't an algorithm + + + align:start position:0% +ancient Egypt this isn't an algorithm +due to here on earth alexandria called + + align:start position:0% +due to here on earth alexandria called + + + align:start position:0% +due to here on earth alexandria called +how to find a square root by successive + + align:start position:0% +how to find a square root by successive + + + align:start position:0% +how to find a square root by successive +averaging and what it says is that in + + align:start position:0% +averaging and what it says is that in + + + align:start position:0% +averaging and what it says is that in +order to find a square root in order to + + align:start position:0% +order to find a square root in order to + + + align:start position:0% +order to find a square root in order to +find a square root you make a guess + + align:start position:0% +find a square root you make a guess + + + align:start position:0% +find a square root you make a guess +you improve that guess and the way you + + align:start position:0% +you improve that guess and the way you + + + align:start position:0% +you improve that guess and the way you +improve the guess is to average the + + align:start position:0% +improve the guess is to average the + + + align:start position:0% +improve the guess is to average the +guess and x over the gas and we'll talk + + align:start position:0% +guess and x over the gas and we'll talk + + + align:start position:0% +guess and x over the gas and we'll talk +a little bit later about what why that's + + align:start position:0% +a little bit later about what why that's + + + align:start position:0% +a little bit later about what why that's +a reasonable thing and you keep + + align:start position:0% +a reasonable thing and you keep + + + align:start position:0% +a reasonable thing and you keep +improving to guess until it's good + + align:start position:0% +improving to guess until it's good + + + align:start position:0% +improving to guess until it's good +enough but that's a method that's how to + + align:start position:0% +enough but that's a method that's how to + + + align:start position:0% +enough but that's a method that's how to +do something as opposed to declarative + + align:start position:0% +do something as opposed to declarative + + + align:start position:0% +do something as opposed to declarative +knowledge that says what you're looking + + align:start position:0% +knowledge that says what you're looking + + + align:start position:0% +knowledge that says what you're looking +for + + align:start position:0% +for + + + align:start position:0% +for +right that's a process + + align:start position:0% + + + + align:start position:0% + +well what's the process in general it's + + align:start position:0% +well what's the process in general it's + + + align:start position:0% +well what's the process in general it's +kind of hard to say you can think of it + + align:start position:0% +kind of hard to say you can think of it + + + align:start position:0% +kind of hard to say you can think of it +as like a magical spirit that sort of + + align:start position:0% +as like a magical spirit that sort of + + + align:start position:0% +as like a magical spirit that sort of +listen the computer and does something + + align:start position:0% +listen the computer and does something + + + align:start position:0% +listen the computer and does something +and the thing that directs the process + + align:start position:0% +and the thing that directs the process + + + align:start position:0% +and the thing that directs the process +is a pattern of rules called a procedure + + align:start position:0% + + + + align:start position:0% + +so procedures are the are the spells if + + align:start position:0% +so procedures are the are the spells if + + + align:start position:0% +so procedures are the are the spells if +you like that control these magical + + align:start position:0% +you like that control these magical + + + align:start position:0% +you like that control these magical +spirits that are the processes and well + + align:start position:0% +spirits that are the processes and well + + + align:start position:0% +spirits that are the processes and well +I guess you know everyone needs a + + align:start position:0% +I guess you know everyone needs a + + + align:start position:0% +I guess you know everyone needs a +magical language and sorcerers but real + + align:start position:0% +magical language and sorcerers but real + + + align:start position:0% +magical language and sorcerers but real +sorcerer is used ancient Akkadian or or + + align:start position:0% +sorcerer is used ancient Akkadian or or + + + align:start position:0% +sorcerer is used ancient Akkadian or or +Sumerian or Babylonian or whatever we're + + align:start position:0% +Sumerian or Babylonian or whatever we're + + + align:start position:0% +Sumerian or Babylonian or whatever we're +gonna conjure up spirits in a magical + + align:start position:0% +gonna conjure up spirits in a magical + + + align:start position:0% +gonna conjure up spirits in a magical +language called Lisp + + align:start position:0% +language called Lisp + + + align:start position:0% +language called Lisp +which is a language designed for talking + + align:start position:0% +which is a language designed for talking + + + align:start position:0% +which is a language designed for talking +about for casting the spells that are + + align:start position:0% +about for casting the spells that are + + + align:start position:0% +about for casting the spells that are +procedures to direct the prophesies now + + align:start position:0% +procedures to direct the prophesies now + + + align:start position:0% +procedures to direct the prophesies now +it's very easy to learn Lisp in fact in + + align:start position:0% +it's very easy to learn Lisp in fact in + + + align:start position:0% +it's very easy to learn Lisp in fact in +a few minutes I'm going to teach you + + align:start position:0% +a few minutes I'm going to teach you + + + align:start position:0% +a few minutes I'm going to teach you +essentially all of Lisp and teach you + + align:start position:0% +essentially all of Lisp and teach you + + + align:start position:0% +essentially all of Lisp and teach you +essentially all of the rules and you + + align:start position:0% +essentially all of the rules and you + + + align:start position:0% +essentially all of the rules and you +shouldn't find that uh that particularly + + align:start position:0% +shouldn't find that uh that particularly + + + align:start position:0% +shouldn't find that uh that particularly +surprising that's sort of like saying + + align:start position:0% +surprising that's sort of like saying + + + align:start position:0% +surprising that's sort of like saying +it's very easy to learn the rules of + + align:start position:0% +it's very easy to learn the rules of + + + align:start position:0% +it's very easy to learn the rules of +chess and indeed in a few minutes you + + align:start position:0% +chess and indeed in a few minutes you + + + align:start position:0% +chess and indeed in a few minutes you +can tell somebody the rules of chess but + + align:start position:0% +can tell somebody the rules of chess but + + + align:start position:0% +can tell somebody the rules of chess but +of course that's very different from + + align:start position:0% +of course that's very different from + + + align:start position:0% +of course that's very different from +saying you understand the implications + + align:start position:0% +saying you understand the implications + + + align:start position:0% +saying you understand the implications +of those rules and how to use those + + align:start position:0% +of those rules and how to use those + + + align:start position:0% +of those rules and how to use those +rules to become a masterful chess player + + align:start position:0% +rules to become a masterful chess player + + + align:start position:0% +rules to become a masterful chess player +well listen it's the same way we're + + align:start position:0% +well listen it's the same way we're + + + align:start position:0% +well listen it's the same way we're +going to state the rules in a few + + align:start position:0% +going to state the rules in a few + + + align:start position:0% +going to state the rules in a few +minutes and we'll be very easy to see + + align:start position:0% +minutes and we'll be very easy to see + + + align:start position:0% +minutes and we'll be very easy to see +but what's really hard is going to be + + align:start position:0% +but what's really hard is going to be + + + align:start position:0% +but what's really hard is going to be +the implications of those rules right + + align:start position:0% +the implications of those rules right + + + align:start position:0% +the implications of those rules right +how you exploit those rules to be a + + align:start position:0% +how you exploit those rules to be a + + + align:start position:0% +how you exploit those rules to be a +master programmer and the implications + + align:start position:0% +master programmer and the implications + + + align:start position:0% +master programmer and the implications +of those rules are going to take us the + + align:start position:0% +of those rules are going to take us the + + + align:start position:0% +of those rules are going to take us the +well the whole rest of the subject and + + align:start position:0% +well the whole rest of the subject and + + + align:start position:0% +well the whole rest of the subject and +of course way beyond okay so in computer + + align:start position:0% +of course way beyond okay so in computer + + + align:start position:0% +of course way beyond okay so in computer +science we're in the business of + + align:start position:0% +science we're in the business of + + + align:start position:0% +science we're in the business of +formalizing is sort of have to + + align:start position:0% +formalizing is sort of have to + + + align:start position:0% +formalizing is sort of have to +imperative knowledge like how to do + + align:start position:0% +imperative knowledge like how to do + + + align:start position:0% +imperative knowledge like how to do +stuff and the real issues of computer + + align:start position:0% +stuff and the real issues of computer + + + align:start position:0% +stuff and the real issues of computer +science are of course not + + align:start position:0% +science are of course not + + + align:start position:0% +science are of course not +you know it's telling people how to do + + align:start position:0% +you know it's telling people how to do + + + align:start position:0% +you know it's telling people how to do +square is so that that was all it was + + align:start position:0% +square is so that that was all it was + + + align:start position:0% +square is so that that was all it was +there wouldn't be no big deal the real + + align:start position:0% +there wouldn't be no big deal the real + + + align:start position:0% +there wouldn't be no big deal the real +problems come when we try to build very + + align:start position:0% +problems come when we try to build very + + + align:start position:0% +problems come when we try to build very +very large system + + align:start position:0% +very large system + + + align:start position:0% +very large system +the computer programs that are that are + + align:start position:0% +the computer programs that are that are + + + align:start position:0% +the computer programs that are that are +thousands of pages long so wrong that + + align:start position:0% +thousands of pages long so wrong that + + + align:start position:0% +thousands of pages long so wrong that +nobody can really hold them in their + + align:start position:0% +nobody can really hold them in their + + + align:start position:0% +nobody can really hold them in their +heads all at once and the only reason + + align:start position:0% +heads all at once and the only reason + + + align:start position:0% +heads all at once and the only reason +that that's possible is because there + + align:start position:0% +that that's possible is because there + + + align:start position:0% +that that's possible is because there +are techniques there techniques for + + align:start position:0% +are techniques there techniques for + + + align:start position:0% +are techniques there techniques for +controlling the complexity of these + + align:start position:0% +controlling the complexity of these + + + align:start position:0% +controlling the complexity of these +large systems and these techniques for + + align:start position:0% +large systems and these techniques for + + + align:start position:0% +large systems and these techniques for +component controlling complexity or what + + align:start position:0% +component controlling complexity or what + + + align:start position:0% +component controlling complexity or what +this course is really that and in some + + align:start position:0% +this course is really that and in some + + + align:start position:0% +this course is really that and in some +sense that's really what computer + + align:start position:0% +sense that's really what computer + + + align:start position:0% +sense that's really what computer +science is about now that may seem like + + align:start position:0% +science is about now that may seem like + + + align:start position:0% +science is about now that may seem like +a very strange thing to say because they + + align:start position:0% +a very strange thing to say because they + + + align:start position:0% +a very strange thing to say because they +after all a lot of people besides + + align:start position:0% +after all a lot of people besides + + + align:start position:0% +after all a lot of people besides +computer scientists deal with + + align:start position:0% +computer scientists deal with + + + align:start position:0% +computer scientists deal with +controlling complexity are they a large + + align:start position:0% +controlling complexity are they a large + + + align:start position:0% +controlling complexity are they a large +airliner is an extremely complex system + + align:start position:0% +airliner is an extremely complex system + + + align:start position:0% +airliner is an extremely complex system +and the aeronautical engineers who + + align:start position:0% +and the aeronautical engineers who + + + align:start position:0% +and the aeronautical engineers who +design that or you know are dealing with + + align:start position:0% +design that or you know are dealing with + + + align:start position:0% +design that or you know are dealing with +immense complexity but there's a + + align:start position:0% +immense complexity but there's a + + + align:start position:0% +immense complexity but there's a +difference between that kind of + + align:start position:0% +difference between that kind of + + + align:start position:0% +difference between that kind of +complexity and what we deal with in + + align:start position:0% +complexity and what we deal with in + + + align:start position:0% +complexity and what we deal with in +computer science and that is that that + + align:start position:0% +computer science and that is that that + + + align:start position:0% +computer science and that is that that +computer science and sometimes isn't + + align:start position:0% +computer science and sometimes isn't + + + align:start position:0% +computer science and sometimes isn't +real you see when an engineer is + + align:start position:0% +real you see when an engineer is + + + align:start position:0% +real you see when an engineer is +designing a physical system that's made + + align:start position:0% +designing a physical system that's made + + + align:start position:0% +designing a physical system that's made +out of real parts like the engineer to + + align:start position:0% +out of real parts like the engineer to + + + align:start position:0% +out of real parts like the engineer to +worry about that has to address problems + + align:start position:0% +worry about that has to address problems + + + align:start position:0% +worry about that has to address problems +of tolerance and approximation and noise + + align:start position:0% +of tolerance and approximation and noise + + + align:start position:0% +of tolerance and approximation and noise +in the system so for example as an + + align:start position:0% +in the system so for example as an + + + align:start position:0% +in the system so for example as an +electrical engineer I can go off and + + align:start position:0% +electrical engineer I can go off and + + + align:start position:0% +electrical engineer I can go off and +easily build a one stage amplifier or a + + align:start position:0% +easily build a one stage amplifier or a + + + align:start position:0% +easily build a one stage amplifier or a +two stage amplifier and I can imagine + + align:start position:0% +two stage amplifier and I can imagine + + + align:start position:0% +two stage amplifier and I can imagine +cascading a lot of them to build a + + align:start position:0% +cascading a lot of them to build a + + + align:start position:0% +cascading a lot of them to build a +million stage amplifier but it's + + align:start position:0% +million stage amplifier but it's + + + align:start position:0% +million stage amplifier but it's +ridiculous to build such a thing because + + align:start position:0% +ridiculous to build such a thing because + + + align:start position:0% +ridiculous to build such a thing because +by the long before the million stage the + + align:start position:0% +by the long before the million stage the + + + align:start position:0% +by the long before the million stage the +thermal noise in those components way at + + align:start position:0% +thermal noise in those components way at + + + align:start position:0% +thermal noise in those components way at +the beginning is going to get amplified + + align:start position:0% +the beginning is going to get amplified + + + align:start position:0% +the beginning is going to get amplified +and make the whole thing meaningless + + align:start position:0% +and make the whole thing meaningless + + + align:start position:0% +and make the whole thing meaningless +computer science deals with idealized + + align:start position:0% +computer science deals with idealized + + + align:start position:0% +computer science deals with idealized +components we know as much as we want + + align:start position:0% +components we know as much as we want + + + align:start position:0% +components we know as much as we want +about these little program and data + + align:start position:0% +about these little program and data + + + align:start position:0% +about these little program and data +pieces that we're fitting things + + align:start position:0% +pieces that we're fitting things + + + align:start position:0% +pieces that we're fitting things +together right so there's we don't have + + align:start position:0% +together right so there's we don't have + + + align:start position:0% +together right so there's we don't have +to worry about tolerance and that means + + align:start position:0% +to worry about tolerance and that means + + + align:start position:0% +to worry about tolerance and that means +that in building a large program + + align:start position:0% +that in building a large program + + + align:start position:0% +that in building a large program +there's not all that much difference + + align:start position:0% +there's not all that much difference + + + align:start position:0% +there's not all that much difference +between what I can build and what I can + + align:start position:0% +between what I can build and what I can + + + align:start position:0% +between what I can build and what I can +imagine because the parts are these + + align:start position:0% +imagine because the parts are these + + + align:start position:0% +imagine because the parts are these +abstract entities that I know as much as + + align:start position:0% +abstract entities that I know as much as + + + align:start position:0% +abstract entities that I know as much as +as much as I want I know about them as + + align:start position:0% +as much as I want I know about them as + + + align:start position:0% +as much as I want I know about them as +precisely as I like so as opposed to + + align:start position:0% +precisely as I like so as opposed to + + + align:start position:0% +precisely as I like so as opposed to +other kinds of engineering where the + + align:start position:0% +other kinds of engineering where the + + + align:start position:0% +other kinds of engineering where the +constraints on which you can build are + + align:start position:0% +constraints on which you can build are + + + align:start position:0% +constraints on which you can build are +the constraints of physical systems the + + align:start position:0% +the constraints of physical systems the + + + align:start position:0% +the constraints of physical systems the +constraints of physics and noise and + + align:start position:0% +constraints of physics and noise and + + + align:start position:0% +constraints of physics and noise and +approximation the constraints imposed in + + align:start position:0% +approximation the constraints imposed in + + + align:start position:0% +approximation the constraints imposed in +building large software systems are the + + align:start position:0% +building large software systems are the + + + align:start position:0% +building large software systems are the +limitations of our own minds so in that + + align:start position:0% +limitations of our own minds so in that + + + align:start position:0% +limitations of our own minds so in that +sense computer science is like an + + align:start position:0% +sense computer science is like an + + + align:start position:0% +sense computer science is like an +abstract form of engineering it's the + + align:start position:0% +abstract form of engineering it's the + + + align:start position:0% +abstract form of engineering it's the +kind of engineering where you ignore the + + align:start position:0% +kind of engineering where you ignore the + + + align:start position:0% +kind of engineering where you ignore the +constraints that are imposed by reality + + align:start position:0% + + + + align:start position:0% + +ok well what are what are some of these + + align:start position:0% +ok well what are what are some of these + + + align:start position:0% +ok well what are what are some of these +techniques they're not special to + + align:start position:0% +techniques they're not special to + + + align:start position:0% +techniques they're not special to +computer science first technique which + + align:start position:0% +computer science first technique which + + + align:start position:0% +computer science first technique which +is used in all of engineering is kind of + + align:start position:0% +is used in all of engineering is kind of + + + align:start position:0% +is used in all of engineering is kind of +abstraction called blackbox abstraction + + align:start position:0% + + + + align:start position:0% + +it takes something and uh they'll build + + align:start position:0% +it takes something and uh they'll build + + + align:start position:0% +it takes something and uh they'll build +a box of doubt yet let's see for example + + align:start position:0% + + + + align:start position:0% + +look at that square root method I might + + align:start position:0% +look at that square root method I might + + + align:start position:0% +look at that square root method I might +want to take that and build a box that + + align:start position:0% +want to take that and build a box that + + + align:start position:0% +want to take that and build a box that +says to find the square root of x and + + align:start position:0% +says to find the square root of x and + + + align:start position:0% +says to find the square root of x and +that might be a whole complicated set of + + align:start position:0% +that might be a whole complicated set of + + + align:start position:0% +that might be a whole complicated set of +rules and that might end up being a kind + + align:start position:0% +rules and that might end up being a kind + + + align:start position:0% +rules and that might end up being a kind +of thing where I can put in say 36 and + + align:start position:0% +of thing where I can put in say 36 and + + + align:start position:0% +of thing where I can put in say 36 and +say what's the square root of 36 and out + + align:start position:0% +say what's the square root of 36 and out + + + align:start position:0% +say what's the square root of 36 and out +comes 6 and the important thing is that + + align:start position:0% +comes 6 and the important thing is that + + + align:start position:0% +comes 6 and the important thing is that +I'd like to design that so that if + + align:start position:0% +I'd like to design that so that if + + + align:start position:0% +I'd like to design that so that if +George comes along and we'd like to + + align:start position:0% +George comes along and we'd like to + + + align:start position:0% +George comes along and we'd like to +compute the square root of a plus the + + align:start position:0% +compute the square root of a plus the + + + align:start position:0% +compute the square root of a plus the +square root of B you can take this thing + + align:start position:0% +square root of B you can take this thing + + + align:start position:0% +square root of B you can take this thing +and use it as a as a module without + + align:start position:0% +and use it as a as a module without + + + align:start position:0% +and use it as a as a module without +having to look inside and build + + align:start position:0% +having to look inside and build + + + align:start position:0% +having to look inside and build +something that looks like this I mean a + + align:start position:0% +something that looks like this I mean a + + + align:start position:0% +something that looks like this I mean a +and B square root box and another square + + align:start position:0% +and B square root box and another square + + + align:start position:0% +and B square root box and another square +root box and then something that adds + + align:start position:0% +root box and then something that adds + + + align:start position:0% +root box and then something that adds +that would put out the answer and you + + align:start position:0% +that would put out the answer and you + + + align:start position:0% +that would put out the answer and you +can see just from the fact that I want + + align:start position:0% +can see just from the fact that I want + + + align:start position:0% +can see just from the fact that I want +to do that is from George's point of + + align:start position:0% +to do that is from George's point of + + + align:start position:0% +to do that is from George's point of +view the internals of what's in here + + align:start position:0% +view the internals of what's in here + + + align:start position:0% +view the internals of what's in here +should not be important so for instance + + align:start position:0% +should not be important so for instance + + + align:start position:0% +should not be important so for instance +shouldn't matter that when I wrote this + + align:start position:0% +shouldn't matter that when I wrote this + + + align:start position:0% +shouldn't matter that when I wrote this +I said I want to find the square root of + + align:start position:0% +I said I want to find the square root of + + + align:start position:0% +I said I want to find the square root of +x I could have said the square root of Y + + align:start position:0% +x I could have said the square root of Y + + + align:start position:0% +x I could have said the square root of Y +or the square root of ay or or anything + + align:start position:0% +or the square root of ay or or anything + + + align:start position:0% +or the square root of ay or or anything +at all but that's the fundamental notion + + align:start position:0% +at all but that's the fundamental notion + + + align:start position:0% +at all but that's the fundamental notion +of putting something in a box using + + align:start position:0% +of putting something in a box using + + + align:start position:0% +of putting something in a box using +blackbox abstraction to suppress detail + + align:start position:0% +blackbox abstraction to suppress detail + + + align:start position:0% +blackbox abstraction to suppress detail +and the reason for that is you want to + + align:start position:0% +and the reason for that is you want to + + + align:start position:0% +and the reason for that is you want to +go off and build your bigger boxes now + + align:start position:0% +go off and build your bigger boxes now + + + align:start position:0% +go off and build your bigger boxes now +there's another reason for doing + + align:start position:0% +there's another reason for doing + + + align:start position:0% +there's another reason for doing +blackbox abstraction other than you want + + align:start position:0% +blackbox abstraction other than you want + + + align:start position:0% +blackbox abstraction other than you want +to suppress detail for building bigger + + align:start position:0% +to suppress detail for building bigger + + + align:start position:0% +to suppress detail for building bigger +boxes sometimes + + align:start position:0% +boxes sometimes + + + align:start position:0% +boxes sometimes +you want to say that your way of doing + + align:start position:0% +you want to say that your way of doing + + + align:start position:0% +you want to say that your way of doing +something your how to method is an + + align:start position:0% +something your how to method is an + + + align:start position:0% +something your how to method is an +instance of a more general thing and + + align:start position:0% +instance of a more general thing and + + + align:start position:0% +instance of a more general thing and +you'd like your language to be able to + + align:start position:0% +you'd like your language to be able to + + + align:start position:0% +you'd like your language to be able to +express their generality let me show you + + align:start position:0% +express their generality let me show you + + + align:start position:0% +express their generality let me show you +another example sticking with square + + align:start position:0% +another example sticking with square + + + align:start position:0% +another example sticking with square +roots let's go back and take another + + align:start position:0% +roots let's go back and take another + + + align:start position:0% +roots let's go back and take another +look at that slide with the square root + + align:start position:0% +look at that slide with the square root + + + align:start position:0% +look at that slide with the square root +algorithm on it remember what that says + + align:start position:0% +algorithm on it remember what that says + + + align:start position:0% +algorithm on it remember what that says +that says in order to to do something I + + align:start position:0% +that says in order to to do something I + + + align:start position:0% +that says in order to to do something I +make a guess and I improve that guess + + align:start position:0% +make a guess and I improve that guess + + + align:start position:0% +make a guess and I improve that guess +and I sort of keep improving that yes + + align:start position:0% +and I sort of keep improving that yes + + + align:start position:0% +and I sort of keep improving that yes +very nice reduce so there's a general + + align:start position:0% +very nice reduce so there's a general + + + align:start position:0% +very nice reduce so there's a general +strategy of are looking for something + + align:start position:0% +strategy of are looking for something + + + align:start position:0% +strategy of are looking for something +and the way I find it is that I keep + + align:start position:0% +and the way I find it is that I keep + + + align:start position:0% +and the way I find it is that I keep +improving it + + align:start position:0% +improving it + + + align:start position:0% +improving it +now that's a particular case of another + + align:start position:0% +now that's a particular case of another + + + align:start position:0% +now that's a particular case of another +kind of strategy for finding a fixed + + align:start position:0% +kind of strategy for finding a fixed + + + align:start position:0% +kind of strategy for finding a fixed +point of something see a fixed point of + + align:start position:0% +point of something see a fixed point of + + + align:start position:0% +point of something see a fixed point of +the function a fixed point of the + + align:start position:0% +the function a fixed point of the + + + align:start position:0% +the function a fixed point of the +function is something this is the ru6 + + align:start position:0% +function is something this is the ru6 + + + align:start position:0% +function is something this is the ru6 +point of the function f is a value Y + + align:start position:0% +point of the function f is a value Y + + + align:start position:0% +point of the function f is a value Y +such that that f of y equals y and the + + align:start position:0% +such that that f of y equals y and the + + + align:start position:0% +such that that f of y equals y and the +way I might do that you + + align:start position:0% +way I might do that you + + + align:start position:0% +way I might do that you +start with a guess and if I want + + align:start position:0% +start with a guess and if I want + + + align:start position:0% +start with a guess and if I want +something that doesn't change when I + + align:start position:0% +something that doesn't change when I + + + align:start position:0% +something that doesn't change when I +keep applying FSI I'll keep applying up + + align:start position:0% +keep applying FSI I'll keep applying up + + + align:start position:0% +keep applying FSI I'll keep applying up +over and over until that result doesn't + + align:start position:0% +over and over until that result doesn't + + + align:start position:0% +over and over until that result doesn't +change very much that's so there's a + + align:start position:0% +change very much that's so there's a + + + align:start position:0% +change very much that's so there's a +general strategy and then for example to + + align:start position:0% +general strategy and then for example to + + + align:start position:0% +general strategy and then for example to +compute the square root of x I can try + + align:start position:0% +compute the square root of x I can try + + + align:start position:0% +compute the square root of x I can try +and find a fixed point of the function + + align:start position:0% +and find a fixed point of the function + + + align:start position:0% +and find a fixed point of the function +which takes Y to the average of x over Y + + align:start position:0% +which takes Y to the average of x over Y + + + align:start position:0% +which takes Y to the average of x over Y +and the idea of that is that if I really + + align:start position:0% +and the idea of that is that if I really + + + align:start position:0% +and the idea of that is that if I really +had y equal to the square root of x then + + align:start position:0% +had y equal to the square root of x then + + + align:start position:0% +had y equal to the square root of x then +y and x over Y would be the same value + + align:start position:0% +y and x over Y would be the same value + + + align:start position:0% +y and x over Y would be the same value +they'd both be the square root of x + + align:start position:0% +they'd both be the square root of x + + + align:start position:0% +they'd both be the square root of x +right + + align:start position:0% +right + + + align:start position:0% +right +x over the square root of x is the + + align:start position:0% +x over the square root of x is the + + + align:start position:0% +x over the square root of x is the +square root of x and so the average if Y + + align:start position:0% +square root of x and so the average if Y + + + align:start position:0% +square root of x and so the average if Y +were equal to the square root of x then + + align:start position:0% +were equal to the square root of x then + + + align:start position:0% +were equal to the square root of x then +the average wouldn't change right so the + + align:start position:0% +the average wouldn't change right so the + + + align:start position:0% +the average wouldn't change right so the +square root of x is a fixed point of + + align:start position:0% +square root of x is a fixed point of + + + align:start position:0% +square root of x is a fixed point of +that particular function now what I'd + + align:start position:0% +that particular function now what I'd + + + align:start position:0% +that particular function now what I'd +like to have I'd like to express the + + align:start position:0% +like to have I'd like to express the + + + align:start position:0% +like to have I'd like to express the +general strategy for finding six points + + align:start position:0% +general strategy for finding six points + + + align:start position:0% +general strategy for finding six points +so what I might imagine doing is to find + + align:start position:0% +so what I might imagine doing is to find + + + align:start position:0% +so what I might imagine doing is to find +is to be able to use my language to + + align:start position:0% +is to be able to use my language to + + + align:start position:0% +is to be able to use my language to +define a box that says fixed point just + + align:start position:0% +define a box that says fixed point just + + + align:start position:0% +define a box that says fixed point just +like I could make a box that says square + + align:start position:0% +like I could make a box that says square + + + align:start position:0% +like I could make a box that says square +root and I'd like to be able to express + + align:start position:0% +root and I'd like to be able to express + + + align:start position:0% +root and I'd like to be able to express +this in my language all right so I'd + + align:start position:0% +this in my language all right so I'd + + + align:start position:0% +this in my language all right so I'd +like to express not only the imperative + + align:start position:0% +like to express not only the imperative + + + align:start position:0% +like to express not only the imperative +how-to knowledge of a particular thing + + align:start position:0% +how-to knowledge of a particular thing + + + align:start position:0% +how-to knowledge of a particular thing +like square root but I'd like to be able + + align:start position:0% +like square root but I'd like to be able + + + align:start position:0% +like square root but I'd like to be able +to express the imperative knowledge of + + align:start position:0% +to express the imperative knowledge of + + + align:start position:0% +to express the imperative knowledge of +how to do a general thing like how to + + align:start position:0% +how to do a general thing like how to + + + align:start position:0% +how to do a general thing like how to +find six points and in fact let's go + + align:start position:0% +find six points and in fact let's go + + + align:start position:0% +find six points and in fact let's go +back and look at that slide again she + + align:start position:0% +back and look at that slide again she + + + align:start position:0% +back and look at that slide again she +not only is + + align:start position:0% + + + + align:start position:0% + +is this a piece of imperative knowledge + + align:start position:0% +is this a piece of imperative knowledge + + + align:start position:0% +is this a piece of imperative knowledge +how to find a fixed point but over here + + align:start position:0% +how to find a fixed point but over here + + + align:start position:0% +how to find a fixed point but over here +on the bottom there's another piece of + + align:start position:0% +on the bottom there's another piece of + + + align:start position:0% +on the bottom there's another piece of +imperative knowledge which is one way to + + align:start position:0% +imperative knowledge which is one way to + + + align:start position:0% +imperative knowledge which is one way to +compute square is is to apply this + + align:start position:0% +compute square is is to apply this + + + align:start position:0% +compute square is is to apply this +general fixed point method so I'd like + + align:start position:0% +general fixed point method so I'd like + + + align:start position:0% +general fixed point method so I'd like +to also be able to express that in + + align:start position:0% +to also be able to express that in + + + align:start position:0% +to also be able to express that in +period of knowledge what would that look + + align:start position:0% +period of knowledge what would that look + + + align:start position:0% +period of knowledge what would that look +like that would say this fixed point box + + align:start position:0% +like that would say this fixed point box + + + align:start position:0% +like that would say this fixed point box +is such that if I input to it the + + align:start position:0% +is such that if I input to it the + + + align:start position:0% +is such that if I input to it the +function that takes Y to the average of + + align:start position:0% +function that takes Y to the average of + + + align:start position:0% +function that takes Y to the average of +Y and X over Y then what should come out + + align:start position:0% +Y and X over Y then what should come out + + + align:start position:0% +Y and X over Y then what should come out +of that fixed point box is a method for + + align:start position:0% +of that fixed point box is a method for + + + align:start position:0% +of that fixed point box is a method for +finding square is so in these boxes + + align:start position:0% +finding square is so in these boxes + + + align:start position:0% +finding square is so in these boxes +we're building we're not only building + + align:start position:0% +we're building we're not only building + + + align:start position:0% +we're building we're not only building +boxes that you input numbers and output + + align:start position:0% +boxes that you input numbers and output + + + align:start position:0% +boxes that you input numbers and output +numbers we can be building in boxes that + + align:start position:0% +numbers we can be building in boxes that + + + align:start position:0% +numbers we can be building in boxes that +in effect compute methods like finding + + align:start position:0% +in effect compute methods like finding + + + align:start position:0% +in effect compute methods like finding +square roots and my take is they're in + + align:start position:0% +square roots and my take is they're in + + + align:start position:0% +square roots and my take is they're in +point inputs functions like Y goes to + + align:start position:0% +point inputs functions like Y goes to + + + align:start position:0% +point inputs functions like Y goes to +the average of y and x over y like we + + align:start position:0% +the average of y and x over y like we + + + align:start position:0% +the average of y and x over y like we +can you want to do that see the reason + + align:start position:0% +can you want to do that see the reason + + + align:start position:0% +can you want to do that see the reason +this is a procedure will end up being a + + align:start position:0% +this is a procedure will end up being a + + + align:start position:0% +this is a procedure will end up being a +procedure as we'll see whose value is + + align:start position:0% +procedure as we'll see whose value is + + + align:start position:0% +procedure as we'll see whose value is +another procedure the reason we want to + + align:start position:0% +another procedure the reason we want to + + + align:start position:0% +another procedure the reason we want to +do that is because procedures are going + + align:start position:0% +do that is because procedures are going + + + align:start position:0% +do that is because procedures are going +to be our ways of talking about + + align:start position:0% +to be our ways of talking about + + + align:start position:0% +to be our ways of talking about +imperative knowledge and the way to make + + align:start position:0% +imperative knowledge and the way to make + + + align:start position:0% +imperative knowledge and the way to make +that very powerful is to be able to talk + + align:start position:0% +that very powerful is to be able to talk + + + align:start position:0% +that very powerful is to be able to talk +about other kinds of knowledge so here + + align:start position:0% +about other kinds of knowledge so here + + + align:start position:0% +about other kinds of knowledge so here +is a procedure that mystech talks about + + align:start position:0% +is a procedure that mystech talks about + + + align:start position:0% +is a procedure that mystech talks about +another procedure by the general + + align:start position:0% +another procedure by the general + + + align:start position:0% +another procedure by the general +strategy that itself talks about general + + align:start position:0% +strategy that itself talks about general + + + align:start position:0% +strategy that itself talks about general +strategy okay well our first topic in + + align:start position:0% +strategy okay well our first topic in + + + align:start position:0% +strategy okay well our first topic in +this course there'll be three major + + align:start position:0% +this course there'll be three major + + + align:start position:0% +this course there'll be three major +major topics will be blackbox + + align:start position:0% +major topics will be blackbox + + + align:start position:0% +major topics will be blackbox +abstraction let's look at that in a + + align:start position:0% +abstraction let's look at that in a + + + align:start position:0% +abstraction let's look at that in a +little bit more detail what we're going + + align:start position:0% +little bit more detail what we're going + + + align:start position:0% +little bit more detail what we're going +to do is we will + + align:start position:0% + + + + align:start position:0% + +we'll start out talking about how list + + align:start position:0% +we'll start out talking about how list + + + align:start position:0% +we'll start out talking about how list +is built up at a primitive object like + + align:start position:0% +is built up at a primitive object like + + + align:start position:0% +is built up at a primitive object like +what is the language supply with us and + + align:start position:0% +what is the language supply with us and + + + align:start position:0% +what is the language supply with us and +we'll see that there are primitive + + align:start position:0% +we'll see that there are primitive + + + align:start position:0% +we'll see that there are primitive +procedures and primitive data then we're + + align:start position:0% +procedures and primitive data then we're + + + align:start position:0% +procedures and primitive data then we're +going to see how do you take those + + align:start position:0% +going to see how do you take those + + + align:start position:0% +going to see how do you take those +primitives and combine them to make more + + align:start position:0% +primitives and combine them to make more + + + align:start position:0% +primitives and combine them to make more +complicated things that means of + + align:start position:0% +complicated things that means of + + + align:start position:0% +complicated things that means of +combinations and what we'll see is that + + align:start position:0% +combinations and what we'll see is that + + + align:start position:0% +combinations and what we'll see is that +there ways of putting things together + + align:start position:0% +there ways of putting things together + + + align:start position:0% +there ways of putting things together +putting primitive procedures together to + + align:start position:0% +putting primitive procedures together to + + + align:start position:0% +putting primitive procedures together to +make more complicated procedures and + + align:start position:0% +make more complicated procedures and + + + align:start position:0% +make more complicated procedures and +we'll see how to put primitive data + + align:start position:0% +we'll see how to put primitive data + + + align:start position:0% +we'll see how to put primitive data +together to make compound data then + + align:start position:0% +together to make compound data then + + + align:start position:0% +together to make compound data then +we'll say well having made those + + align:start position:0% +we'll say well having made those + + + align:start position:0% +we'll say well having made those +compound things how do you abstract them + + align:start position:0% +compound things how do you abstract them + + + align:start position:0% +compound things how do you abstract them +how do you put those black boxes around + + align:start position:0% +how do you put those black boxes around + + + align:start position:0% +how do you put those black boxes around +them so you can use them as components + + align:start position:0% +them so you can use them as components + + + align:start position:0% +them so you can use them as components +in more complex things and we'll see + + align:start position:0% +in more complex things and we'll see + + + align:start position:0% +in more complex things and we'll see +that's done by defining procedures and a + + align:start position:0% +that's done by defining procedures and a + + + align:start position:0% +that's done by defining procedures and a +technique for dealing with compound data + + align:start position:0% +technique for dealing with compound data + + + align:start position:0% +technique for dealing with compound data +called data abstraction and then what's + + align:start position:0% +called data abstraction and then what's + + + align:start position:0% +called data abstraction and then what's +maybe the most important thing is going + + align:start position:0% +maybe the most important thing is going + + + align:start position:0% +maybe the most important thing is going +from just the rule to add as an expert + + align:start position:0% +from just the rule to add as an expert + + + align:start position:0% +from just the rule to add as an expert +work how do you express common patterns + + align:start position:0% +work how do you express common patterns + + + align:start position:0% +work how do you express common patterns +of doing things like saying well there's + + align:start position:0% +of doing things like saying well there's + + + align:start position:0% +of doing things like saying well there's +a general method of fixed point and + + align:start position:0% +a general method of fixed point and + + + align:start position:0% +a general method of fixed point and +square root is a particular case of that + + align:start position:0% +square root is a particular case of that + + + align:start position:0% +square root is a particular case of that +and we're going to use I've already + + align:start position:0% +and we're going to use I've already + + + align:start position:0% +and we're going to use I've already +hinted at it something called + + align:start position:0% +hinted at it something called + + + align:start position:0% +hinted at it something called +higher-order procedures namely + + align:start position:0% +higher-order procedures namely + + + align:start position:0% +higher-order procedures namely +procedures whose inputs and outputs are + + align:start position:0% +procedures whose inputs and outputs are + + + align:start position:0% +procedures whose inputs and outputs are +themselves procedures and then we'll + + align:start position:0% +themselves procedures and then we'll + + + align:start position:0% +themselves procedures and then we'll +also see something very interesting + + align:start position:0% +also see something very interesting + + + align:start position:0% +also see something very interesting +we'll see as we go further and further + + align:start position:0% +we'll see as we go further and further + + + align:start position:0% +we'll see as we go further and further +on and become more abstract they'll be + + align:start position:0% +on and become more abstract they'll be + + + align:start position:0% +on and become more abstract they'll be +very well the line between what we + + align:start position:0% +very well the line between what we + + + align:start position:0% +very well the line between what we +consider to be data and what we consider + + align:start position:0% +consider to be data and what we consider + + + align:start position:0% +consider to be data and what we consider +to be procedures is going to blur at an + + align:start position:0% +to be procedures is going to blur at an + + + align:start position:0% +to be procedures is going to blur at an +incredible rate well that's a that's our + + align:start position:0% +incredible rate well that's a that's our + + + align:start position:0% +incredible rate well that's a that's our +first subject blackbox abstraction let's + + align:start position:0% +first subject blackbox abstraction let's + + + align:start position:0% +first subject blackbox abstraction let's +look at the second topic he introduced + + align:start position:0% +look at the second topic he introduced + + + align:start position:0% +look at the second topic he introduced +it like this he suppose I I want to + + align:start position:0% +it like this he suppose I I want to + + + align:start position:0% +it like this he suppose I I want to +express the idea and remember we're + + align:start position:0% +express the idea and remember we're + + + align:start position:0% +express the idea and remember we're +we're talking about ideas I don't want + + align:start position:0% +we're talking about ideas I don't want + + + align:start position:0% +we're talking about ideas I don't want +to express the idea that I can take + + align:start position:0% +to express the idea that I can take + + + align:start position:0% +to express the idea that I can take +something + + align:start position:0% +something + + + align:start position:0% +something +and multiply it by the sum of two other + + align:start position:0% +and multiply it by the sum of two other + + + align:start position:0% +and multiply it by the sum of two other +things so for example I might say if I + + align:start position:0% +things so for example I might say if I + + + align:start position:0% +things so for example I might say if I +add one entry and multiply that by 2 I + + align:start position:0% +add one entry and multiply that by 2 I + + + align:start position:0% +add one entry and multiply that by 2 I +get a but I'm talking about the general + + align:start position:0% +get a but I'm talking about the general + + + align:start position:0% +get a but I'm talking about the general +idea of what's called linear combination + + align:start position:0% +idea of what's called linear combination + + + align:start position:0% +idea of what's called linear combination +that you can add two things and multiply + + align:start position:0% +that you can add two things and multiply + + + align:start position:0% +that you can add two things and multiply +them by something else very easy when I + + align:start position:0% +them by something else very easy when I + + + align:start position:0% +them by something else very easy when I +think about it for numbers but suppose I + + align:start position:0% +think about it for numbers but suppose I + + + align:start position:0% +think about it for numbers but suppose I +I also want to use that same idea to + + align:start position:0% +I also want to use that same idea to + + + align:start position:0% +I also want to use that same idea to +think about I could add two vectors a 1 + + align:start position:0% +think about I could add two vectors a 1 + + + align:start position:0% +think about I could add two vectors a 1 +and a 2 and then scale them by some say + + align:start position:0% +and a 2 and then scale them by some say + + + align:start position:0% +and a 2 and then scale them by some say +after X and get another vector or I + + align:start position:0% +after X and get another vector or I + + + align:start position:0% +after X and get another vector or I +might say I want to think about a 1 and + + align:start position:0% +might say I want to think about a 1 and + + + align:start position:0% +might say I want to think about a 1 and +a 2 as being polynomials and I might + + align:start position:0% +a 2 as being polynomials and I might + + + align:start position:0% +a 2 as being polynomials and I might +want to add those two polynomials and + + align:start position:0% +want to add those two polynomials and + + + align:start position:0% +want to add those two polynomials and +then multiply them by 2 to get a more + + align:start position:0% +then multiply them by 2 to get a more + + + align:start position:0% +then multiply them by 2 to get a more +complicated one or a 1 and H you might + + align:start position:0% +complicated one or a 1 and H you might + + + align:start position:0% +complicated one or a 1 and H you might +be electrical signals and I might want + + align:start position:0% +be electrical signals and I might want + + + align:start position:0% +be electrical signals and I might want +to think of that summing those two + + align:start position:0% +to think of that summing those two + + + align:start position:0% +to think of that summing those two +electrical signals and then amp putting + + align:start position:0% +electrical signals and then amp putting + + + align:start position:0% +electrical signals and then amp putting +the whole thing to an amplifier + + align:start position:0% +the whole thing to an amplifier + + + align:start position:0% +the whole thing to an amplifier +multiplying it by by some factor of 2 or + + align:start position:0% +multiplying it by by some factor of 2 or + + + align:start position:0% +multiplying it by by some factor of 2 or +something the idea is I want to think + + align:start position:0% +something the idea is I want to think + + + align:start position:0% +something the idea is I want to think +about the general notion of that now if + + align:start position:0% +about the general notion of that now if + + + align:start position:0% +about the general notion of that now if +our language is going to be a good + + align:start position:0% +our language is going to be a good + + + align:start position:0% +our language is going to be a good +language for expressing those kind of + + align:start position:0% +language for expressing those kind of + + + align:start position:0% +language for expressing those kind of +general ideas I really really can do + + align:start position:0% +general ideas I really really can do + + + align:start position:0% +general ideas I really really can do +that so I'd like to be able to say I'm + + align:start position:0% +that so I'd like to be able to say I'm + + + align:start position:0% +that so I'd like to be able to say I'm +going to multiply by X the sum of a 1 + + align:start position:0% +going to multiply by X the sum of a 1 + + + align:start position:0% +going to multiply by X the sum of a 1 +and a 2 and I'd like that to express the + + align:start position:0% +and a 2 and I'd like that to express the + + + align:start position:0% +and a 2 and I'd like that to express the +general idea of all different kinds of + + align:start position:0% +general idea of all different kinds of + + + align:start position:0% +general idea of all different kinds of +things that a 1 and a 2 could be now if + + align:start position:0% +things that a 1 and a 2 could be now if + + + align:start position:0% +things that a 1 and a 2 could be now if +you think about that there's a problem + + align:start position:0% +you think about that there's a problem + + + align:start position:0% +you think about that there's a problem +because after all the actual primitive + + align:start position:0% +because after all the actual primitive + + + align:start position:0% +because after all the actual primitive +operations that go on in the machine are + + align:start position:0% +operations that go on in the machine are + + + align:start position:0% +operations that go on in the machine are +obviously going to be different if I'm + + align:start position:0% +obviously going to be different if I'm + + + align:start position:0% +obviously going to be different if I'm +adding two numbers than finally adding + + align:start position:0% +adding two numbers than finally adding + + + align:start position:0% +adding two numbers than finally adding +two polynomials or if I'm adding the + + align:start position:0% +two polynomials or if I'm adding the + + + align:start position:0% +two polynomials or if I'm adding the +representation of two electrical signals + + align:start position:0% +representation of two electrical signals + + + align:start position:0% +representation of two electrical signals +or waveforms somewhere there has to be + + align:start position:0% +or waveforms somewhere there has to be + + + align:start position:0% +or waveforms somewhere there has to be +the knowledge of the kinds of various + + align:start position:0% +the knowledge of the kinds of various + + + align:start position:0% +the knowledge of the kinds of various +things that you can add and the ways of + + align:start position:0% +things that you can add and the ways of + + + align:start position:0% +things that you can add and the ways of +adding them + + align:start position:0% + + + + align:start position:0% + +construct such a system the question is + + align:start position:0% +construct such a system the question is + + + align:start position:0% +construct such a system the question is +where do I put that knowledge how do I + + align:start position:0% +where do I put that knowledge how do I + + + align:start position:0% +where do I put that knowledge how do I +think about the different kinds of + + align:start position:0% +think about the different kinds of + + + align:start position:0% +think about the different kinds of +choices I have and if tomorrow George + + align:start position:0% +choices I have and if tomorrow George + + + align:start position:0% +choices I have and if tomorrow George +comes up with a new kind of object that + + align:start position:0% +comes up with a new kind of object that + + + align:start position:0% +comes up with a new kind of object that +might be added and multiplied how do I + + align:start position:0% +might be added and multiplied how do I + + + align:start position:0% +might be added and multiplied how do I +add George's new object to the system + + align:start position:0% +add George's new object to the system + + + align:start position:0% +add George's new object to the system +without screwing up everything that was + + align:start position:0% +without screwing up everything that was + + + align:start position:0% +without screwing up everything that was +already here but well that's going to be + + align:start position:0% +already here but well that's going to be + + + align:start position:0% +already here but well that's going to be +the the second big topic the way of + + align:start position:0% +the the second big topic the way of + + + align:start position:0% +the the second big topic the way of +controlling that kind of complexity and + + align:start position:0% +controlling that kind of complexity and + + + align:start position:0% +controlling that kind of complexity and +the way you do that is by establishing + + align:start position:0% +the way you do that is by establishing + + + align:start position:0% +the way you do that is by establishing +conventional interfaces agreed-upon ways + + align:start position:0% +conventional interfaces agreed-upon ways + + + align:start position:0% +conventional interfaces agreed-upon ways +of plugging things together just like in + + align:start position:0% +of plugging things together just like in + + + align:start position:0% +of plugging things together just like in +electrical engineering people have + + align:start position:0% +electrical engineering people have + + + align:start position:0% +electrical engineering people have +standard impedances for connectors and + + align:start position:0% +standard impedances for connectors and + + + align:start position:0% +standard impedances for connectors and +then you know if you build something + + align:start position:0% +then you know if you build something + + + align:start position:0% +then you know if you build something +with one of those standard impedances + + align:start position:0% +with one of those standard impedances + + + align:start position:0% +with one of those standard impedances +you can plug it together with something + + align:start position:0% +you can plug it together with something + + + align:start position:0% +you can plug it together with something +else like that's going to be our second + + align:start position:0% +else like that's going to be our second + + + align:start position:0% +else like that's going to be our second +large topic conventional interfaces what + + align:start position:0% +large topic conventional interfaces what + + + align:start position:0% +large topic conventional interfaces what +we're going to see is when first we're + + align:start position:0% +we're going to see is when first we're + + + align:start position:0% +we're going to see is when first we're +going to talk about the problem of + + align:start position:0% +going to talk about the problem of + + + align:start position:0% +going to talk about the problem of +generic operations which is the one I + + align:start position:0% +generic operations which is the one I + + + align:start position:0% +generic operations which is the one I +alluded to things like plus that that + + align:start position:0% +alluded to things like plus that that + + + align:start position:0% +alluded to things like plus that that +have to work with all different kinds of + + align:start position:0% +have to work with all different kinds of + + + align:start position:0% +have to work with all different kinds of +data + + align:start position:0% + + + + align:start position:0% + +we talked about generic operations then + + align:start position:0% +we talked about generic operations then + + + align:start position:0% +we talked about generic operations then +we're going to talk about really + + align:start position:0% +we're going to talk about really + + + align:start position:0% +we're going to talk about really +large-scale structures how do you put + + align:start position:0% +large-scale structures how do you put + + + align:start position:0% +large-scale structures how do you put +together very large programs that model + + align:start position:0% +together very large programs that model + + + align:start position:0% +together very large programs that model +the kinds of complex systems in the real + + align:start position:0% +the kinds of complex systems in the real + + + align:start position:0% +the kinds of complex systems in the real +world that you'd like to model and what + + align:start position:0% +world that you'd like to model and what + + + align:start position:0% +world that you'd like to model and what +we're going to see is that there are two + + align:start position:0% +we're going to see is that there are two + + + align:start position:0% +we're going to see is that there are two +very important metaphors for putting + + align:start position:0% +very important metaphors for putting + + + align:start position:0% +very important metaphors for putting +together such systems one is called + + align:start position:0% +together such systems one is called + + + align:start position:0% +together such systems one is called +object-oriented programming where you + + align:start position:0% +object-oriented programming where you + + + align:start position:0% +object-oriented programming where you +sort of think of your system as a kind + + align:start position:0% +sort of think of your system as a kind + + + align:start position:0% +sort of think of your system as a kind +of society full of little things that + + align:start position:0% +of society full of little things that + + + align:start position:0% +of society full of little things that +interact by sending information between + + align:start position:0% +interact by sending information between + + + align:start position:0% +interact by sending information between +them and then the second one is + + align:start position:0% +them and then the second one is + + + align:start position:0% +them and then the second one is +operations on aggregates called streams + + align:start position:0% +operations on aggregates called streams + + + align:start position:0% +operations on aggregates called streams +where you think of a large system put + + align:start position:0% +where you think of a large system put + + + align:start position:0% +where you think of a large system put +together kind of like a signal + + align:start position:0% +together kind of like a signal + + + align:start position:0% +together kind of like a signal +processing engineer puts together a + + align:start position:0% +processing engineer puts together a + + + align:start position:0% +processing engineer puts together a +large electrical system that's going to + + align:start position:0% +large electrical system that's going to + + + align:start position:0% +large electrical system that's going to +be our second topic now the third thing + + align:start position:0% +be our second topic now the third thing + + + align:start position:0% +be our second topic now the third thing +we're going to come to the third basic + + align:start position:0% +we're going to come to the third basic + + + align:start position:0% +we're going to come to the third basic +technique for controlling complexity is + + align:start position:0% +technique for controlling complexity is + + + align:start position:0% +technique for controlling complexity is +making new languages sometimes when + + align:start position:0% +making new languages sometimes when + + + align:start position:0% +making new languages sometimes when +you're sort of overwhelmed by the + + align:start position:0% +you're sort of overwhelmed by the + + + align:start position:0% +you're sort of overwhelmed by the +complexity of a design the way that you + + align:start position:0% +complexity of a design the way that you + + + align:start position:0% +complexity of a design the way that you +control that complexity is to pick a new + + align:start position:0% +control that complexity is to pick a new + + + align:start position:0% +control that complexity is to pick a new +design language and the purpose of the + + align:start position:0% +design language and the purpose of the + + + align:start position:0% +design language and the purpose of the +new design language will be to highlight + + align:start position:0% +new design language will be to highlight + + + align:start position:0% +new design language will be to highlight +different aspects of the system it'll + + align:start position:0% +different aspects of the system it'll + + + align:start position:0% +different aspects of the system it'll +suppress some kinds of details and + + align:start position:0% +suppress some kinds of details and + + + align:start position:0% +suppress some kinds of details and +emphasize other kinds of detail this is + + align:start position:0% +emphasize other kinds of detail this is + + + align:start position:0% +emphasize other kinds of detail this is +going to be the sort of the most magical + + align:start position:0% +going to be the sort of the most magical + + + align:start position:0% +going to be the sort of the most magical +part of the course we're going to start + + align:start position:0% +part of the course we're going to start + + + align:start position:0% +part of the course we're going to start +out by actually looking at the + + align:start position:0% +out by actually looking at the + + + align:start position:0% +out by actually looking at the +technology for building new computer + + align:start position:0% +technology for building new computer + + + align:start position:0% +technology for building new computer +languages and will be the first thing + + align:start position:0% +languages and will be the first thing + + + align:start position:0% +languages and will be the first thing +we're going to do is actually build in + + align:start position:0% +we're going to do is actually build in + + + align:start position:0% +we're going to do is actually build in +Lisp a problem we're going to express in + + align:start position:0% +Lisp a problem we're going to express in + + + align:start position:0% +Lisp a problem we're going to express in +list the process of interpreting list + + align:start position:0% +list the process of interpreting list + + + align:start position:0% +list the process of interpreting list +itself and that's going to be a very + + align:start position:0% +itself and that's going to be a very + + + align:start position:0% +itself and that's going to be a very +sort of self circular thing there's a + + align:start position:0% +sort of self circular thing there's a + + + align:start position:0% +sort of self circular thing there's a +little mystical symbol that have to do + + align:start position:0% +little mystical symbol that have to do + + + align:start position:0% +little mystical symbol that have to do +with that will see itself the process of + + align:start position:0% +with that will see itself the process of + + + align:start position:0% +with that will see itself the process of +interpreting lists is sort of a a giant + + align:start position:0% +interpreting lists is sort of a a giant + + + align:start position:0% +interpreting lists is sort of a a giant +wheel of two processes apply an eval + + align:start position:0% +wheel of two processes apply an eval + + + align:start position:0% +wheel of two processes apply an eval +which sort of constantly reduce + + align:start position:0% +which sort of constantly reduce + + + align:start position:0% +which sort of constantly reduce +expressions to each other then we're + + align:start position:0% +expressions to each other then we're + + + align:start position:0% +expressions to each other then we're +gonna see all sorts of other magical + + align:start position:0% +gonna see all sorts of other magical + + + align:start position:0% +gonna see all sorts of other magical +things here's another another magical + + align:start position:0% +things here's another another magical + + + align:start position:0% +things here's another another magical +system symbol this is kind of the sort + + align:start position:0% +system symbol this is kind of the sort + + + align:start position:0% +system symbol this is kind of the sort +of the why operator which is in some + + align:start position:0% +of the why operator which is in some + + + align:start position:0% +of the why operator which is in some +sense the expression of infinity inside + + align:start position:0% +sense the expression of infinity inside + + + align:start position:0% +sense the expression of infinity inside +our + + align:start position:0% +our + + + align:start position:0% +our +Sidra language we'll take a look at that + + align:start position:0% +Sidra language we'll take a look at that + + + align:start position:0% +Sidra language we'll take a look at that +in any case this section of the course + + align:start position:0% +in any case this section of the course + + + align:start position:0% +in any case this section of the course +is called metalinguistic abstraction + + align:start position:0% + + + + align:start position:0% + +talking abstract + + align:start position:0% +talking abstract + + + align:start position:0% +talking abstract +by talking about how you construct new + + align:start position:0% +by talking about how you construct new + + + align:start position:0% +by talking about how you construct new +languages as I said we're going to start + + align:start position:0% +languages as I said we're going to start + + + align:start position:0% +languages as I said we're going to start +out by looking at the process of + + align:start position:0% +out by looking at the process of + + + align:start position:0% +out by looking at the process of +interpretation we're going to look at + + align:start position:0% +interpretation we're going to look at + + + align:start position:0% +interpretation we're going to look at +this apply eval loop and build lists + + align:start position:0% +this apply eval loop and build lists + + + align:start position:0% +this apply eval loop and build lists +then just to show you that this is very + + align:start position:0% +then just to show you that this is very + + + align:start position:0% +then just to show you that this is very +general we're going to use exactly the + + align:start position:0% +general we're going to use exactly the + + + align:start position:0% +general we're going to use exactly the +same technology to build a very + + align:start position:0% +same technology to build a very + + + align:start position:0% +same technology to build a very +different kind of language so called + + align:start position:0% +different kind of language so called + + + align:start position:0% +different kind of language so called +logic programming language where you + + align:start position:0% +logic programming language where you + + + align:start position:0% +logic programming language where you +don't really talk about procedures at + + align:start position:0% +don't really talk about procedures at + + + align:start position:0% +don't really talk about procedures at +all that have inputs and outputs what + + align:start position:0% +all that have inputs and outputs what + + + align:start position:0% +all that have inputs and outputs what +you do is talk about relations between + + align:start position:0% +you do is talk about relations between + + + align:start position:0% +you do is talk about relations between +things and then finally we're going to + + align:start position:0% +things and then finally we're going to + + + align:start position:0% +things and then finally we're going to +talk about how you implement these + + align:start position:0% +talk about how you implement these + + + align:start position:0% +talk about how you implement these +things very concretely on the very + + align:start position:0% +things very concretely on the very + + + align:start position:0% +things very concretely on the very +simplest kind of machines even though + + align:start position:0% +simplest kind of machines even though + + + align:start position:0% +simplest kind of machines even though +we'll see something like this which is + + align:start position:0% +we'll see something like this which is + + + align:start position:0% +we'll see something like this which is +this is a picture of the of the chip + + align:start position:0% +this is a picture of the of the chip + + + align:start position:0% +this is a picture of the of the chip +which is the Lisp interpreter that we + + align:start position:0% +which is the Lisp interpreter that we + + + align:start position:0% +which is the Lisp interpreter that we +will be talking about then in hardware + + align:start position:0% +will be talking about then in hardware + + + align:start position:0% +will be talking about then in hardware +okay well there's there's an outline of + + align:start position:0% +okay well there's there's an outline of + + + align:start position:0% +okay well there's there's an outline of +the course three big topics black out + + align:start position:0% +the course three big topics black out + + + align:start position:0% +the course three big topics black out +box abstraction conventional interfaces + + align:start position:0% +box abstraction conventional interfaces + + + align:start position:0% +box abstraction conventional interfaces +middle linguistic abstraction + + align:start position:0% +middle linguistic abstraction + + + align:start position:0% +middle linguistic abstraction +now let's take a break now and then + + align:start position:0% +now let's take a break now and then + + + align:start position:0% +now let's take a break now and then +we'll get started + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +well let's let's actually start in + + align:start position:0% +well let's let's actually start in + + + align:start position:0% +well let's let's actually start in +learning list now actually we'll start + + align:start position:0% +learning list now actually we'll start + + + align:start position:0% +learning list now actually we'll start +out by learning something much more + + align:start position:0% +out by learning something much more + + + align:start position:0% +out by learning something much more +important maybe the very most important + + align:start position:0% +important maybe the very most important + + + align:start position:0% +important maybe the very most important +thing in this course which is not list + + align:start position:0% +thing in this course which is not list + + + align:start position:0% +thing in this course which is not list +in particular of course but rather a + + align:start position:0% +in particular of course but rather a + + + align:start position:0% +in particular of course but rather a +general framework for thinking about + + align:start position:0% +general framework for thinking about + + + align:start position:0% +general framework for thinking about +languages they already alluded to when + + align:start position:0% +languages they already alluded to when + + + align:start position:0% +languages they already alluded to when +somebody tells you they're going to show + + align:start position:0% +somebody tells you they're going to show + + + align:start position:0% +somebody tells you they're going to show +you a language what you should say is + + align:start position:0% +you a language what you should say is + + + align:start position:0% +you a language what you should say is +all right what I'd like you to tell me + + align:start position:0% +all right what I'd like you to tell me + + + align:start position:0% +all right what I'd like you to tell me +is what are the what are the primitive + + align:start position:0% +is what are the what are the primitive + + + align:start position:0% +is what are the what are the primitive +elements what is the language come with + + align:start position:0% +elements what is the language come with + + + align:start position:0% +elements what is the language come with +then what are the ways you put those + + align:start position:0% +then what are the ways you put those + + + align:start position:0% +then what are the ways you put those +together what are the means of + + align:start position:0% +together what are the means of + + + align:start position:0% +together what are the means of +combination what are the things that + + align:start position:0% +combination what are the things that + + + align:start position:0% +combination what are the things that +allow you to take these primitive + + align:start position:0% +allow you to take these primitive + + + align:start position:0% +allow you to take these primitive +elements and build bigger things out of + + align:start position:0% +elements and build bigger things out of + + + align:start position:0% +elements and build bigger things out of +them what are the ways of putting things + + align:start position:0% +them what are the ways of putting things + + + align:start position:0% +them what are the ways of putting things +together and then what are the means of + + align:start position:0% +together and then what are the means of + + + align:start position:0% +together and then what are the means of +abstraction how do we take those + + align:start position:0% +abstraction how do we take those + + + align:start position:0% +abstraction how do we take those +complicated things and draw those boxes + + align:start position:0% +complicated things and draw those boxes + + + align:start position:0% +complicated things and draw those boxes +around them how do we name them so that + + align:start position:0% +around them how do we name them so that + + + align:start position:0% +around them how do we name them so that +we can now use them as if they were + + align:start position:0% +we can now use them as if they were + + + align:start position:0% +we can now use them as if they were +primitive elements in making still more + + align:start position:0% +primitive elements in making still more + + + align:start position:0% +primitive elements in making still more +complex things and so on and so on and + + align:start position:0% +complex things and so on and so on and + + + align:start position:0% +complex things and so on and so on and +so on so when someone says to you gee I + + align:start position:0% +so on so when someone says to you gee I + + + align:start position:0% +so on so when someone says to you gee I +have a great new computer language you + + align:start position:0% +have a great new computer language you + + + align:start position:0% +have a great new computer language you +don't say how many characters does it + + align:start position:0% +don't say how many characters does it + + + align:start position:0% +don't say how many characters does it +take to invert a matrix that it's + + align:start position:0% +take to invert a matrix that it's + + + align:start position:0% +take to invert a matrix that it's +irrelevant right what you say is how if + + align:start position:0% +irrelevant right what you say is how if + + + align:start position:0% +irrelevant right what you say is how if +the language did not come with matrices + + align:start position:0% +the language did not come with matrices + + + align:start position:0% +the language did not come with matrices +built-in or with something else then how + + align:start position:0% +built-in or with something else then how + + + align:start position:0% +built-in or with something else then how +could I then build that thing what are + + align:start position:0% +could I then build that thing what are + + + align:start position:0% +could I then build that thing what are +the means of combination which would + + align:start position:0% +the means of combination which would + + + align:start position:0% +the means of combination which would +allow me to do that and then what are + + align:start position:0% +allow me to do that and then what are + + + align:start position:0% +allow me to do that and then what are +the needs of the abstraction which allow + + align:start position:0% +the needs of the abstraction which allow + + + align:start position:0% +the needs of the abstraction which allow +me then to use those are the elements in + + align:start position:0% +me then to use those are the elements in + + + align:start position:0% +me then to use those are the elements in +making more complicated things yet well + + align:start position:0% +making more complicated things yet well + + + align:start position:0% +making more complicated things yet well +we're going to see that list has some + + align:start position:0% +we're going to see that list has some + + + align:start position:0% +we're going to see that list has some +primitive data and some primitive + + align:start position:0% +primitive data and some primitive + + + align:start position:0% +primitive data and some primitive +procedures in fact let's let's really + + align:start position:0% +procedures in fact let's let's really + + + align:start position:0% +procedures in fact let's let's really +start and here's a piece of primitive + + align:start position:0% +start and here's a piece of primitive + + + align:start position:0% +start and here's a piece of primitive +data and Lisp let's say + + align:start position:0% +data and Lisp let's say + + + align:start position:0% +data and Lisp let's say +right number three actually from being + + align:start position:0% +right number three actually from being + + + align:start position:0% +right number three actually from being +very pedantic that's not the number + + align:start position:0% +very pedantic that's not the number + + + align:start position:0% +very pedantic that's not the number +three that's some symbol that represents + + align:start position:0% +three that's some symbol that represents + + + align:start position:0% +three that's some symbol that represents +no Plato's concept of the number three + + align:start position:0% +no Plato's concept of the number three + + + align:start position:0% +no Plato's concept of the number three +right and here's another here's some + + align:start position:0% +right and here's another here's some + + + align:start position:0% +right and here's another here's some +more primitive data in Lisp right it's + + align:start position:0% +more primitive data in Lisp right it's + + + align:start position:0% +more primitive data in Lisp right it's +seventeen point four actually some + + align:start position:0% +seventeen point four actually some + + + align:start position:0% +seventeen point four actually some +representation of seventeen point four + + align:start position:0% +representation of seventeen point four + + + align:start position:0% +representation of seventeen point four +and here's another one five + + align:start position:0% + + + + align:start position:0% + +here's another primitive object that's + + align:start position:0% +here's another primitive object that's + + + align:start position:0% +here's another primitive object that's +built in Lisp addition actually use the + + align:start position:0% +built in Lisp addition actually use the + + + align:start position:0% +built in Lisp addition actually use the +same kind of pedantic this is a name for + + align:start position:0% +same kind of pedantic this is a name for + + + align:start position:0% +same kind of pedantic this is a name for +the primitive method of adding things + + align:start position:0% +the primitive method of adding things + + + align:start position:0% +the primitive method of adding things +just like this is a name for Plato's + + align:start position:0% +just like this is a name for Plato's + + + align:start position:0% +just like this is a name for Plato's +number three + + align:start position:0% +number three + + + align:start position:0% +number three +this is a name for Plato's concept of + + align:start position:0% +this is a name for Plato's concept of + + + align:start position:0% +this is a name for Plato's concept of +how you how you add things but sure + + align:start position:0% +how you how you add things but sure + + + align:start position:0% +how you how you add things but sure +those are some primitive the elements I + + align:start position:0% +those are some primitive the elements I + + + align:start position:0% +those are some primitive the elements I +can put them together I can say gee + + align:start position:0% +can put them together I can say gee + + + align:start position:0% +can put them together I can say gee +watch the sum of three and seventeen + + align:start position:0% +watch the sum of three and seventeen + + + align:start position:0% +watch the sum of three and seventeen +point four and five the way I do that is + + align:start position:0% +point four and five the way I do that is + + + align:start position:0% +point four and five the way I do that is +to say let's apply the Sun operator to + + align:start position:0% +to say let's apply the Sun operator to + + + align:start position:0% +to say let's apply the Sun operator to +these three numbers and I should get + + align:start position:0% +these three numbers and I should get + + + align:start position:0% +these three numbers and I should get +what eight seventeen twenty five point + + align:start position:0% +what eight seventeen twenty five point + + + align:start position:0% +what eight seventeen twenty five point +four I should be able to ask Lisp what + + align:start position:0% +four I should be able to ask Lisp what + + + align:start position:0% +four I should be able to ask Lisp what +the value of this is and we'll return + + align:start position:0% +the value of this is and we'll return + + + align:start position:0% +the value of this is and we'll return +twenty five point four + + align:start position:0% + + + + align:start position:0% + +let's introduce some names this thing + + align:start position:0% +let's introduce some names this thing + + + align:start position:0% +let's introduce some names this thing +that I typed + + align:start position:0% + + + + align:start position:0% + +it's called a combination and a + + align:start position:0% +it's called a combination and a + + + align:start position:0% +it's called a combination and a +combination consistent general of + + align:start position:0% +combination consistent general of + + + align:start position:0% +combination consistent general of +applying an operator so this is an + + align:start position:0% +applying an operator so this is an + + + align:start position:0% +applying an operator so this is an +operator to some operands these are the + + align:start position:0% +operator to some operands these are the + + + align:start position:0% +operator to some operands these are the +operands + + align:start position:0% + + + + align:start position:0% + +and of course I can make more complex + + align:start position:0% +and of course I can make more complex + + + align:start position:0% +and of course I can make more complex +things the reason I can get complexity + + align:start position:0% +things the reason I can get complexity + + + align:start position:0% +things the reason I can get complexity +out of this is because the operands + + align:start position:0% +out of this is because the operands + + + align:start position:0% +out of this is because the operands +themselves in general can be + + align:start position:0% +themselves in general can be + + + align:start position:0% +themselves in general can be +combinations so for instance I could say + + align:start position:0% +combinations so for instance I could say + + + align:start position:0% +combinations so for instance I could say +what is the sum of 3 and the product of + + align:start position:0% +what is the sum of 3 and the product of + + + align:start position:0% +what is the sum of 3 and the product of +five and six and eight and two and I + + align:start position:0% +five and six and eight and two and I + + + align:start position:0% +five and six and eight and two and I +should get let's say 30 40 43 so this + + align:start position:0% +should get let's say 30 40 43 so this + + + align:start position:0% +should get let's say 30 40 43 so this +should tell me that that's 43 forming + + align:start position:0% +should tell me that that's 43 forming + + + align:start position:0% +should tell me that that's 43 forming +combinations well is that basic means + + align:start position:0% +combinations well is that basic means + + + align:start position:0% +combinations well is that basic means +the combination that we'll be looking at + + align:start position:0% +the combination that we'll be looking at + + + align:start position:0% +the combination that we'll be looking at +and then well you see some some syntax + + align:start position:0% +and then well you see some some syntax + + + align:start position:0% +and then well you see some some syntax +here Lisp uses what's called prefix + + align:start position:0% +here Lisp uses what's called prefix + + + align:start position:0% +here Lisp uses what's called prefix +notation which means that the operator + + align:start position:0% + + + + align:start position:0% + +that the operator is written to the left + + align:start position:0% +that the operator is written to the left + + + align:start position:0% +that the operator is written to the left +of the operands it's just a convention + + align:start position:0% +of the operands it's just a convention + + + align:start position:0% +of the operands it's just a convention +and notice it's fully parenthesized and + + align:start position:0% +and notice it's fully parenthesized and + + + align:start position:0% +and notice it's fully parenthesized and +the parenthesis make it completely + + align:start position:0% +the parenthesis make it completely + + + align:start position:0% +the parenthesis make it completely +unambiguous so by looking at this I can + + align:start position:0% +unambiguous so by looking at this I can + + + align:start position:0% +unambiguous so by looking at this I can +see that there's the operator and there + + align:start position:0% +see that there's the operator and there + + + align:start position:0% +see that there's the operator and there +1 2 3 4 operands right and I can see + + align:start position:0% +1 2 3 4 operands right and I can see + + + align:start position:0% +1 2 3 4 operands right and I can see +that the second operand here is itself + + align:start position:0% +that the second operand here is itself + + + align:start position:0% +that the second operand here is itself +some combination that has one Operator + + align:start position:0% +some combination that has one Operator + + + align:start position:0% +some combination that has one Operator +and two operands parentheses in list + + align:start position:0% +and two operands parentheses in list + + + align:start position:0% +and two operands parentheses in list +they're a little bit or are very unlike + + align:start position:0% +they're a little bit or are very unlike + + + align:start position:0% +they're a little bit or are very unlike +parentheses and conventional mathematics + + align:start position:0% +parentheses and conventional mathematics + + + align:start position:0% +parentheses and conventional mathematics +mathematics we sort of use them to mean + + align:start position:0% +mathematics we sort of use them to mean + + + align:start position:0% +mathematics we sort of use them to mean +grouping and it sort of doesn't hurt if + + align:start position:0% +grouping and it sort of doesn't hurt if + + + align:start position:0% +grouping and it sort of doesn't hurt if +sometimes you leave out parentheses if + + align:start position:0% +sometimes you leave out parentheses if + + + align:start position:0% +sometimes you leave out parentheses if +people understand that that's a group + + align:start position:0% +people understand that that's a group + + + align:start position:0% +people understand that that's a group +and in general it doesn't hurt if you + + align:start position:0% +and in general it doesn't hurt if you + + + align:start position:0% +and in general it doesn't hurt if you +put in extra parentheses that because + + align:start position:0% +put in extra parentheses that because + + + align:start position:0% +put in extra parentheses that because +that maybe makes the grouping more + + align:start position:0% +that maybe makes the grouping more + + + align:start position:0% +that maybe makes the grouping more +distinct list is not like that enlist + + align:start position:0% +distinct list is not like that enlist + + + align:start position:0% +distinct list is not like that enlist +you cannot leave out parentheses and you + + align:start position:0% +you cannot leave out parentheses and you + + + align:start position:0% +you cannot leave out parentheses and you +cannot put in extra parentheses right + + align:start position:0% +cannot put in extra parentheses right + + + align:start position:0% +cannot put in extra parentheses right +because putting in parentheses always + + align:start position:0% +because putting in parentheses always + + + align:start position:0% +because putting in parentheses always +mean exactly and precisely this is a + + align:start position:0% +mean exactly and precisely this is a + + + align:start position:0% +mean exactly and precisely this is a +combination which has meaning apply an + + align:start position:0% +combination which has meaning apply an + + + align:start position:0% +combination which has meaning apply an +operator to operands and if I lift this + + align:start position:0% +operator to operands and if I lift this + + + align:start position:0% +operator to operands and if I lift this +out + + align:start position:0% +out + + + align:start position:0% +out +let those parentheses out it would mean + + align:start position:0% +let those parentheses out it would mean + + + align:start position:0% +let those parentheses out it would mean +something else in fact the way to think + + align:start position:0% +something else in fact the way to think + + + align:start position:0% +something else in fact the way to think +about this is really what I'm doing when + + align:start position:0% +about this is really what I'm doing when + + + align:start position:0% +about this is really what I'm doing when +I write something like this is writing a + + align:start position:0% +I write something like this is writing a + + + align:start position:0% +I write something like this is writing a +tree so this combination is a tree that + + align:start position:0% +tree so this combination is a tree that + + + align:start position:0% +tree so this combination is a tree that +has a plus and then a 3 and then there's + + align:start position:0% +has a plus and then a 3 and then there's + + + align:start position:0% +has a plus and then a 3 and then there's +something else and an 8 and a 2 and then + + align:start position:0% +something else and an 8 and a 2 and then + + + align:start position:0% +something else and an 8 and a 2 and then +there's something else here is itself + + align:start position:0% +there's something else here is itself + + + align:start position:0% +there's something else here is itself +little subtree that has a star and a + + align:start position:0% +little subtree that has a star and a + + + align:start position:0% +little subtree that has a star and a +five and a six and the way to think of + + align:start position:0% +five and a six and the way to think of + + + align:start position:0% +five and a six and the way to think of +that is really what's going on or we're + + align:start position:0% +that is really what's going on or we're + + + align:start position:0% +that is really what's going on or we're +writing these trees and parentheses are + + align:start position:0% +writing these trees and parentheses are + + + align:start position:0% +writing these trees and parentheses are +just a way to write this two-dimensional + + align:start position:0% +just a way to write this two-dimensional + + + align:start position:0% +just a way to write this two-dimensional +structure as a linear character string + + align:start position:0% +structure as a linear character string + + + align:start position:0% +structure as a linear character string +because at least one whisper started and + + align:start position:0% +because at least one whisper started and + + + align:start position:0% +because at least one whisper started and +people had teletypes or punch cards or + + align:start position:0% +people had teletypes or punch cards or + + + align:start position:0% +people had teletypes or punch cards or +whatever this was more convenient they + + align:start position:0% +whatever this was more convenient they + + + align:start position:0% +whatever this was more convenient they +couldn't maybe if lists started today we + + align:start position:0% +couldn't maybe if lists started today we + + + align:start position:0% +couldn't maybe if lists started today we +would the syntax of Lisp would look like + + align:start position:0% +would the syntax of Lisp would look like + + + align:start position:0% +would the syntax of Lisp would look like +that well let's let's look at what that + + align:start position:0% +that well let's let's look at what that + + + align:start position:0% +that well let's let's look at what that +actually looks like on the computer + + align:start position:0% +actually looks like on the computer + + + align:start position:0% +actually looks like on the computer +right here I have a lisp interaction + + align:start position:0% +right here I have a lisp interaction + + + align:start position:0% +right here I have a lisp interaction +setup there's an editor and on the top + + align:start position:0% +setup there's an editor and on the top + + + align:start position:0% +setup there's an editor and on the top +I'm going to type some values and ask + + align:start position:0% +I'm going to type some values and ask + + + align:start position:0% +I'm going to type some values and ask +Lisp what they are so for instance I can + + align:start position:0% +Lisp what they are so for instance I can + + + align:start position:0% +Lisp what they are so for instance I can +say to Lisp what's the value of that + + align:start position:0% +say to Lisp what's the value of that + + + align:start position:0% +say to Lisp what's the value of that +symbol that's 3 and I asked to evaluate + + align:start position:0% +symbol that's 3 and I asked to evaluate + + + align:start position:0% +symbol that's 3 and I asked to evaluate +it and there you see list is returned on + + align:start position:0% +it and there you see list is returned on + + + align:start position:0% +it and there you see list is returned on +the bottom and said oh yeah that's 3 or + + align:start position:0% +the bottom and said oh yeah that's 3 or + + + align:start position:0% +the bottom and said oh yeah that's 3 or +I can say what's the sum of 3 & 4 & 8 + + align:start position:0% +I can say what's the sum of 3 & 4 & 8 + + + align:start position:0% +I can say what's the sum of 3 & 4 & 8 +what's that combination and ask list to + + align:start position:0% +what's that combination and ask list to + + + align:start position:0% +what's that combination and ask list to +evaluate it + + align:start position:0% + + + + align:start position:0% + +and that's 15 well I can type in + + align:start position:0% +and that's 15 well I can type in + + + align:start position:0% +and that's 15 well I can type in +something more complicated I can say + + align:start position:0% +something more complicated I can say + + + align:start position:0% +something more complicated I can say +what's the sum of the product of three + + align:start position:0% +what's the sum of the product of three + + + align:start position:0% +what's the sum of the product of three +and the sum of seven and nineteen and a + + align:start position:0% +and the sum of seven and nineteen and a + + + align:start position:0% +and the sum of seven and nineteen and a +half and you'll notice here that list + + align:start position:0% +half and you'll notice here that list + + + align:start position:0% +half and you'll notice here that list +has something built in that helped me + + align:start position:0% +has something built in that helped me + + + align:start position:0% +has something built in that helped me +keep track of all these parentheses + + align:start position:0% +keep track of all these parentheses + + + align:start position:0% +keep track of all these parentheses +watch as I type the next closed + + align:start position:0% +watch as I type the next closed + + + align:start position:0% +watch as I type the next closed +parenthesis which is going to close the + + align:start position:0% +parenthesis which is going to close the + + + align:start position:0% +parenthesis which is going to close the +combination starting with the star the + + align:start position:0% +combination starting with the star the + + + align:start position:0% +combination starting with the star the +opening one will flash there I'll rub + + align:start position:0% +opening one will flash there I'll rub + + + align:start position:0% +opening one will flash there I'll rub +this out and do it again type closed and + + align:start position:0% +this out and do it again type closed and + + + align:start position:0% +this out and do it again type closed and +you see that closed as the plus closed + + align:start position:0% +you see that closed as the plus closed + + + align:start position:0% +you see that closed as the plus closed +again that quizzes the star right now + + align:start position:0% +again that quizzes the star right now + + + align:start position:0% +again that quizzes the star right now +I'm back to the sum and maybe I'm going + + align:start position:0% +I'm back to the sum and maybe I'm going + + + align:start position:0% +I'm back to the sum and maybe I'm going +to add that all to for that closes the + + align:start position:0% +to add that all to for that closes the + + + align:start position:0% +to add that all to for that closes the +plus now I have a complete combination + + align:start position:0% +plus now I have a complete combination + + + align:start position:0% +plus now I have a complete combination +and I can ask this for the value of that + + align:start position:0% +and I can ask this for the value of that + + + align:start position:0% +and I can ask this for the value of that +that kind of paren balancing is + + align:start position:0% +that kind of paren balancing is + + + align:start position:0% +that kind of paren balancing is +something that's that's built into a lot + + align:start position:0% +something that's that's built into a lot + + + align:start position:0% +something that's that's built into a lot +of Lisp systems to help you keep track + + align:start position:0% +of Lisp systems to help you keep track + + + align:start position:0% +of Lisp systems to help you keep track +because it is kind of hard just by hand + + align:start position:0% +because it is kind of hard just by hand + + + align:start position:0% +because it is kind of hard just by hand +doing all these parentheses there's + + align:start position:0% +doing all these parentheses there's + + + align:start position:0% +doing all these parentheses there's +another there's another kind of + + align:start position:0% +another there's another kind of + + + align:start position:0% +another there's another kind of +convention for keeping track of + + align:start position:0% +convention for keeping track of + + + align:start position:0% +convention for keeping track of +parentheses let me write another + + align:start position:0% +parentheses let me write another + + + align:start position:0% +parentheses let me write another +complicated combination let's take the + + align:start position:0% +complicated combination let's take the + + + align:start position:0% +complicated combination let's take the +sum of the product of 3 & 5 and add that + + align:start position:0% +sum of the product of 3 & 5 and add that + + + align:start position:0% +sum of the product of 3 & 5 and add that +to something and now what I'm going to + + align:start position:0% +to something and now what I'm going to + + + align:start position:0% +to something and now what I'm going to +do is I'm going to indent so that the + + align:start position:0% +do is I'm going to indent so that the + + + align:start position:0% +do is I'm going to indent so that the +operands are written vertically what's + + align:start position:0% +operands are written vertically what's + + + align:start position:0% +operands are written vertically what's +the sum of that and the product of 47 + + align:start position:0% +the sum of that and the product of 47 + + + align:start position:0% +the sum of that and the product of 47 +and let's say the product of 47 with the + + align:start position:0% +and let's say the product of 47 with the + + + align:start position:0% +and let's say the product of 47 with the +difference of 20 and 6.8 that means + + align:start position:0% +difference of 20 and 6.8 that means + + + align:start position:0% +difference of 20 and 6.8 that means +subtract 6.8 from 20 you see the + + align:start position:0% +subtract 6.8 from 20 you see the + + + align:start position:0% +subtract 6.8 from 20 you see the +parentheses close close the - close the + + align:start position:0% +parentheses close close the - close the + + + align:start position:0% +parentheses close close the - close the +store and now let's get another operator + + align:start position:0% +store and now let's get another operator + + + align:start position:0% +store and now let's get another operator +you see the list editor here it's + + align:start position:0% +you see the list editor here it's + + + align:start position:0% +you see the list editor here it's +indenting to the right position + + align:start position:0% +indenting to the right position + + + align:start position:0% +indenting to the right position +automatically help me keep track hey do + + align:start position:0% +automatically help me keep track hey do + + + align:start position:0% +automatically help me keep track hey do +that again I'll close that last + + align:start position:0% +that again I'll close that last + + + align:start position:0% +that again I'll close that last +parenthesis again is he it balances the + + align:start position:0% +parenthesis again is he it balances the + + + align:start position:0% +parenthesis again is he it balances the +plus + + align:start position:0% + + + + align:start position:0% + +right now I can say what's the value of + + align:start position:0% +right now I can say what's the value of + + + align:start position:0% +right now I can say what's the value of +that all right so uh those two things + + align:start position:0% +that all right so uh those two things + + + align:start position:0% +that all right so uh those two things +indenting to the right level which is + + align:start position:0% +indenting to the right level which is + + + align:start position:0% +indenting to the right level which is +called pretty printing and flashing + + align:start position:0% +called pretty printing and flashing + + + align:start position:0% +called pretty printing and flashing +parentheses are two things that a lot of + + align:start position:0% +parentheses are two things that a lot of + + + align:start position:0% +parentheses are two things that a lot of +systems have have built in to help you + + align:start position:0% +systems have have built in to help you + + + align:start position:0% +systems have have built in to help you +keep track and you should learn how to + + align:start position:0% +keep track and you should learn how to + + + align:start position:0% +keep track and you should learn how to +use them okay well those are the + + align:start position:0% +use them okay well those are the + + + align:start position:0% +use them okay well those are the +primitives there's a means of + + align:start position:0% +primitives there's a means of + + + align:start position:0% +primitives there's a means of +combination now let's go up to the means + + align:start position:0% +combination now let's go up to the means + + + align:start position:0% +combination now let's go up to the means +of abstraction right I'd like to be able + + align:start position:0% +of abstraction right I'd like to be able + + + align:start position:0% +of abstraction right I'd like to be able +to take the idea that I do some + + align:start position:0% +to take the idea that I do some + + + align:start position:0% +to take the idea that I do some +combination like this and abstract it + + align:start position:0% +combination like this and abstract it + + + align:start position:0% +combination like this and abstract it +and give it a simple name so I can use + + align:start position:0% +and give it a simple name so I can use + + + align:start position:0% +and give it a simple name so I can use +that as an element and I do that in Lisp + + align:start position:0% +that as an element and I do that in Lisp + + + align:start position:0% +that as an element and I do that in Lisp +with define so I could say for example + + align:start position:0% +with define so I could say for example + + + align:start position:0% +with define so I could say for example +define a to be the product of five and + + align:start position:0% +define a to be the product of five and + + + align:start position:0% +define a to be the product of five and +five and now I could say so say for + + align:start position:0% +five and now I could say so say for + + + align:start position:0% +five and now I could say so say for +example two lists what is the product of + + align:start position:0% +example two lists what is the product of + + + align:start position:0% +example two lists what is the product of +a and a this should be 25 and there + + align:start position:0% +a and a this should be 25 and there + + + align:start position:0% +a and a this should be 25 and there +should be six twenty five and then + + align:start position:0% +should be six twenty five and then + + + align:start position:0% +should be six twenty five and then +crucial thing I can now use a here I've + + align:start position:0% +crucial thing I can now use a here I've + + + align:start position:0% +crucial thing I can now use a here I've +used it in the combination but I could + + align:start position:0% +used it in the combination but I could + + + align:start position:0% +used it in the combination but I could +use that in other more complicated + + align:start position:0% +use that in other more complicated + + + align:start position:0% +use that in other more complicated +things that I need in turn so I could + + align:start position:0% +things that I need in turn so I could + + + align:start position:0% +things that I need in turn so I could +say define B to be the sum of will say a + + align:start position:0% +say define B to be the sum of will say a + + + align:start position:0% +say define B to be the sum of will say a +and the product of five and a you close + + align:start position:0% +and the product of five and a you close + + + align:start position:0% +and the product of five and a you close +the plus let's take a look at that on + + align:start position:0% +the plus let's take a look at that on + + + align:start position:0% +the plus let's take a look at that on +the computer see how that looks + + align:start position:0% +the computer see how that looks + + + align:start position:0% +the computer see how that looks +it's all I'll just type what I wrote on + + align:start position:0% +it's all I'll just type what I wrote on + + + align:start position:0% +it's all I'll just type what I wrote on +the board I can say define + + align:start position:0% + + + + align:start position:0% + +a to be the product of five and five + + align:start position:0% + + + + align:start position:0% + +I'll tell that to lift and notice what + + align:start position:0% +I'll tell that to lift and notice what + + + align:start position:0% +I'll tell that to lift and notice what +Lisp responded there with with an A in + + align:start position:0% +Lisp responded there with with an A in + + + align:start position:0% +Lisp responded there with with an A in +the bottom in general when you type in a + + align:start position:0% +the bottom in general when you type in a + + + align:start position:0% +the bottom in general when you type in a +definition that lifts it responds with + + align:start position:0% +definition that lifts it responds with + + + align:start position:0% +definition that lifts it responds with +the knee the symbol being defined and I + + align:start position:0% +the knee the symbol being defined and I + + + align:start position:0% +the knee the symbol being defined and I +could say the list what is the product + + align:start position:0% +could say the list what is the product + + + align:start position:0% +could say the list what is the product +of a and a it says that's 625 I can + + align:start position:0% +of a and a it says that's 625 I can + + + align:start position:0% +of a and a it says that's 625 I can +define B to be the sum of a and the + + align:start position:0% +define B to be the sum of a and the + + + align:start position:0% +define B to be the sum of a and the +product of five and a close a friend + + align:start position:0% +product of five and a close a friend + + + align:start position:0% +product of five and a close a friend +closes the store close the press close + + align:start position:0% +closes the store close the press close + + + align:start position:0% +closes the store close the press close +the define this says okay be there on + + align:start position:0% +the define this says okay be there on + + + align:start position:0% +the define this says okay be there on +the bottom and now I can tell you list + + align:start position:0% +the bottom and now I can tell you list + + + align:start position:0% +the bottom and now I can tell you list +what's the value of B and I can say + + align:start position:0% +what's the value of B and I can say + + + align:start position:0% +what's the value of B and I can say +something more complicated like what's + + align:start position:0% +something more complicated like what's + + + align:start position:0% +something more complicated like what's +the sum of a and the quotient of B and + + align:start position:0% +the sum of a and the quotient of B and + + + align:start position:0% +the sum of a and the quotient of B and +five that slash is divided another + + align:start position:0% +five that slash is divided another + + + align:start position:0% +five that slash is divided another +primitive operator I've divided you by + + align:start position:0% +primitive operator I've divided you by + + + align:start position:0% +primitive operator I've divided you by +far the entity to a this is okay that's + + align:start position:0% +far the entity to a this is okay that's + + + align:start position:0% +far the entity to a this is okay that's +55 all right so there's what it looks + + align:start position:0% +55 all right so there's what it looks + + + align:start position:0% +55 all right so there's what it looks +like there's the basic means of defining + + align:start position:0% +like there's the basic means of defining + + + align:start position:0% +like there's the basic means of defining +some something it's the simplest kind of + + align:start position:0% +some something it's the simplest kind of + + + align:start position:0% +some something it's the simplest kind of +naming but it's not really very powerful + + align:start position:0% +naming but it's not really very powerful + + + align:start position:0% +naming but it's not really very powerful +see what I'd really like to name we're + + align:start position:0% +see what I'd really like to name we're + + + align:start position:0% +see what I'd really like to name we're +talking about general methods I'd like + + align:start position:0% +talking about general methods I'd like + + + align:start position:0% +talking about general methods I'd like +to name or the general idea that for + + align:start position:0% +to name or the general idea that for + + + align:start position:0% +to name or the general idea that for +example I could multiply five by five or + + align:start position:0% +example I could multiply five by five or + + + align:start position:0% +example I could multiply five by five or +six by six Oh + + align:start position:0% + + + + align:start position:0% + +thousand and one by a thousand and one a + + align:start position:0% +thousand and one by a thousand and one a + + + align:start position:0% +thousand and one by a thousand and one a +thousand 1.7 by a thousand and 1.7 right + + align:start position:0% +thousand 1.7 by a thousand and 1.7 right + + + align:start position:0% +thousand 1.7 by a thousand and 1.7 right +I'd like to be able to name the general + + align:start position:0% +I'd like to be able to name the general + + + align:start position:0% +I'd like to be able to name the general +idea of multiplying something by itself + + align:start position:0% + + + + align:start position:0% + +we know what that is that's called + + align:start position:0% +we know what that is that's called + + + align:start position:0% +we know what that is that's called +squaring the way I can do that and Lisp + + align:start position:0% +squaring the way I can do that and Lisp + + + align:start position:0% +squaring the way I can do that and Lisp +is I can say you're fine just square + + align:start position:0% + + + + align:start position:0% + +something X multiply X by itself and + + align:start position:0% +something X multiply X by itself and + + + align:start position:0% +something X multiply X by itself and +then having having done that I could say + + align:start position:0% +then having having done that I could say + + + align:start position:0% +then having having done that I could say +so list for example what's the square of + + align:start position:0% +so list for example what's the square of + + + align:start position:0% +so list for example what's the square of +10 and this will say a hundred yeah + + align:start position:0% +10 and this will say a hundred yeah + + + align:start position:0% +10 and this will say a hundred yeah +let's actually look at that a little + + align:start position:0% +let's actually look at that a little + + + align:start position:0% +let's actually look at that a little +more closely Yeah right there's the + + align:start position:0% +more closely Yeah right there's the + + + align:start position:0% +more closely Yeah right there's the +definition of square to square something + + align:start position:0% +definition of square to square something + + + align:start position:0% +definition of square to square something +right multiply it by itself all right + + align:start position:0% +right multiply it by itself all right + + + align:start position:0% +right multiply it by itself all right +you see this X here right that X is kind + + align:start position:0% +you see this X here right that X is kind + + + align:start position:0% +you see this X here right that X is kind +of a pronoun which is the something that + + align:start position:0% +of a pronoun which is the something that + + + align:start position:0% +of a pronoun which is the something that +I'm going to square and then what I do + + align:start position:0% +I'm going to square and then what I do + + + align:start position:0% +I'm going to square and then what I do +with it is I multiply X by multiply it + + align:start position:0% +with it is I multiply X by multiply it + + + align:start position:0% +with it is I multiply X by multiply it +by itself okay right so there's a + + align:start position:0% +by itself okay right so there's a + + + align:start position:0% +by itself okay right so there's a +notation for a for defining a procedure + + align:start position:0% +notation for a for defining a procedure + + + align:start position:0% +notation for a for defining a procedure +actually this is a little bit confusing + + align:start position:0% +actually this is a little bit confusing + + + align:start position:0% +actually this is a little bit confusing +because sort of how I might use square + + align:start position:0% +because sort of how I might use square + + + align:start position:0% +because sort of how I might use square +and I say square of X or square of 10 + + align:start position:0% +and I say square of X or square of 10 + + + align:start position:0% +and I say square of X or square of 10 +but it's not making it very clear that + + align:start position:0% +but it's not making it very clear that + + + align:start position:0% +but it's not making it very clear that +I'm actually naming something so let me + + align:start position:0% +I'm actually naming something so let me + + + align:start position:0% +I'm actually naming something so let me +write this definition in another way + + align:start position:0% +write this definition in another way + + + align:start position:0% +write this definition in another way +that makes a little bit more clear that + + align:start position:0% +that makes a little bit more clear that + + + align:start position:0% +that makes a little bit more clear that +I'm naming something I'll say define + + align:start position:0% + + + + align:start position:0% + +Square to be lambda of X times X X + + align:start position:0% + + + + align:start position:0% + +here I'm meaning something square but + + align:start position:0% +here I'm meaning something square but + + + align:start position:0% +here I'm meaning something square but +just like over here I'm naming something + + align:start position:0% +just like over here I'm naming something + + + align:start position:0% +just like over here I'm naming something +a the thing that I'm naming square here + + align:start position:0% +a the thing that I'm naming square here + + + align:start position:0% +a the thing that I'm naming square here +I named the thing I named a was the + + align:start position:0% +I named the thing I named a was the + + + align:start position:0% +I named the thing I named a was the +value of this combination here the thing + + align:start position:0% +value of this combination here the thing + + + align:start position:0% +value of this combination here the thing +that I'm naming square is this thing + + align:start position:0% +that I'm naming square is this thing + + + align:start position:0% +that I'm naming square is this thing +that begins with lambda and lambda is + + align:start position:0% +that begins with lambda and lambda is + + + align:start position:0% +that begins with lambda and lambda is +lisps way of saying make up procedure + + align:start position:0% + + + + align:start position:0% + +let's look at that more closely on the + + align:start position:0% +let's look at that more closely on the + + + align:start position:0% +let's look at that more closely on the +slide the way I read that definition is + + align:start position:0% +slide the way I read that definition is + + + align:start position:0% +slide the way I read that definition is +to say I define Square to be make a + + align:start position:0% +to say I define Square to be make a + + + align:start position:0% +to say I define Square to be make a +procedure that's what the lambda is make + + align:start position:0% +procedure that's what the lambda is make + + + align:start position:0% +procedure that's what the lambda is make +a procedure with an argument named X and + + align:start position:0% +a procedure with an argument named X and + + + align:start position:0% +a procedure with an argument named X and +what it does is return the result of + + align:start position:0% +what it does is return the result of + + + align:start position:0% +what it does is return the result of +multiplying X by itself now in general + + align:start position:0% +multiplying X by itself now in general + + + align:start position:0% +multiplying X by itself now in general +we're going to be using we're going to + + align:start position:0% +we're going to be using we're going to + + + align:start position:0% +we're going to be using we're going to +be using this top form of defining this + + align:start position:0% +be using this top form of defining this + + + align:start position:0% +be using this top form of defining this +because it's a little bit more + + align:start position:0% +because it's a little bit more + + + align:start position:0% +because it's a little bit more +convenient but don't lose sight of the + + align:start position:0% +convenient but don't lose sight of the + + + align:start position:0% +convenient but don't lose sight of the +fact that it's really this in fact as + + align:start position:0% +fact that it's really this in fact as + + + align:start position:0% +fact that it's really this in fact as +far as the Lisp interpreter is concerned + + align:start position:0% +far as the Lisp interpreter is concerned + + + align:start position:0% +far as the Lisp interpreter is concerned +there's no difference between typing + + align:start position:0% +there's no difference between typing + + + align:start position:0% +there's no difference between typing +this to it and typing this to it and + + align:start position:0% +this to it and typing this to it and + + + align:start position:0% +this to it and typing this to it and +there's a word for that we're sort of + + align:start position:0% +there's a word for that we're sort of + + + align:start position:0% +there's a word for that we're sort of +syntactic sugar + + align:start position:0% +syntactic sugar + + + align:start position:0% +syntactic sugar +what syntactic sugar means it's having + + align:start position:0% +what syntactic sugar means it's having + + + align:start position:0% +what syntactic sugar means it's having +somewhat more convenient surface forms + + align:start position:0% +somewhat more convenient surface forms + + + align:start position:0% +somewhat more convenient surface forms +for typing something so this is just + + align:start position:0% +for typing something so this is just + + + align:start position:0% +for typing something so this is just +really syntactic sugar for this + + align:start position:0% +really syntactic sugar for this + + + align:start position:0% +really syntactic sugar for this +underlying weak thing with the lambda + + align:start position:0% +underlying weak thing with the lambda + + + align:start position:0% +underlying weak thing with the lambda +and the reason you should remember that + + align:start position:0% +and the reason you should remember that + + + align:start position:0% +and the reason you should remember that +is don't forget that when I write + + align:start position:0% +is don't forget that when I write + + + align:start position:0% +is don't forget that when I write +something like this I'm really naming + + align:start position:0% +something like this I'm really naming + + + align:start position:0% +something like this I'm really naming +something I'm naming something square + + align:start position:0% +something I'm naming something square + + + align:start position:0% +something I'm naming something square +and the something that I'm naming square + + align:start position:0% +and the something that I'm naming square + + + align:start position:0% +and the something that I'm naming square +is a procedure that's getting + + align:start position:0% +is a procedure that's getting + + + align:start position:0% +is a procedure that's getting +constructed ok well let's let's look at + + align:start position:0% +constructed ok well let's let's look at + + + align:start position:0% +constructed ok well let's let's look at +that on the computer too so I'll come in + + align:start position:0% +that on the computer too so I'll come in + + + align:start position:0% +that on the computer too so I'll come in +I'll say define square of X give you + + align:start position:0% +I'll say define square of X give you + + + align:start position:0% +I'll say define square of X give you +times X X + + align:start position:0% + + + + align:start position:0% + +and I can + + align:start position:0% + + + + align:start position:0% + +you know I'll tell this fat to square + + align:start position:0% +you know I'll tell this fat to square + + + align:start position:0% +you know I'll tell this fat to square +you have named something square and now + + align:start position:0% +you have named something square and now + + + align:start position:0% +you have named something square and now +having done that I can ask list for + + align:start position:0% +having done that I can ask list for + + + align:start position:0% +having done that I can ask list for +what's the square of a thousand and one + + align:start position:0% + + + + align:start position:0% + +or in general I could say what's the + + align:start position:0% +or in general I could say what's the + + + align:start position:0% +or in general I could say what's the +square of the sum of five and seven + + align:start position:0% + + + + align:start position:0% + +all right square twelves 144 or I can + + align:start position:0% +all right square twelves 144 or I can + + + align:start position:0% +all right square twelves 144 or I can +use square itself as an element in some + + align:start position:0% +use square itself as an element in some + + + align:start position:0% +use square itself as an element in some +combination I can say what's the sum of + + align:start position:0% +combination I can say what's the sum of + + + align:start position:0% +combination I can say what's the sum of +the square of 3 and the square of 4 + + align:start position:0% + + + + align:start position:0% + +hey 1916 is 25 or I can use square as an + + align:start position:0% +hey 1916 is 25 or I can use square as an + + + align:start position:0% +hey 1916 is 25 or I can use square as an +element in some much more complicated + + align:start position:0% +element in some much more complicated + + + align:start position:0% +element in some much more complicated +thing I can say what's the what's the + + align:start position:0% +thing I can say what's the what's the + + + align:start position:0% +thing I can say what's the what's the +square of the square of the square of + + align:start position:0% +square of the square of the square of + + + align:start position:0% +square of the square of the square of +1,001 + + align:start position:0% + + + + align:start position:0% + +there's the square of the square of the + + align:start position:0% +there's the square of the square of the + + + align:start position:0% +there's the square of the square of the +square of 1,001 or I can say the list + + align:start position:0% +square of 1,001 or I can say the list + + + align:start position:0% +square of 1,001 or I can say the list +what is square itself what's the value + + align:start position:0% +what is square itself what's the value + + + align:start position:0% +what is square itself what's the value +of that and Lisp returns some + + align:start position:0% +of that and Lisp returns some + + + align:start position:0% +of that and Lisp returns some +conventional way of telling me that + + align:start position:0% +conventional way of telling me that + + + align:start position:0% +conventional way of telling me that +that's a procedure does compound + + align:start position:0% +that's a procedure does compound + + + align:start position:0% +that's a procedure does compound +procedure Square and what the value of + + align:start position:0% +procedure Square and what the value of + + + align:start position:0% +procedure Square and what the value of +square is this procedure and the thing + + align:start position:0% +square is this procedure and the thing + + + align:start position:0% +square is this procedure and the thing +with the Stars and the brackets are just + + align:start position:0% +with the Stars and the brackets are just + + + align:start position:0% +with the Stars and the brackets are just +lisps conventional way of describing + + align:start position:0% +lisps conventional way of describing + + + align:start position:0% +lisps conventional way of describing +that let's look at two more examples of + + align:start position:0% +that let's look at two more examples of + + + align:start position:0% +that let's look at two more examples of +defining this right here there are two + + align:start position:0% +defining this right here there are two + + + align:start position:0% +defining this right here there are two +more procedures I can define the average + + align:start position:0% +more procedures I can define the average + + + align:start position:0% +more procedures I can define the average +of x and y to be the sum of x and y / - + + align:start position:0% +of x and y to be the sum of x and y / - + + + align:start position:0% +of x and y to be the sum of x and y / - +we're having had average and mean square + + align:start position:0% +we're having had average and mean square + + + align:start position:0% +we're having had average and mean square +having had average in square I can use + + align:start position:0% +having had average in square I can use + + + align:start position:0% +having had average in square I can use +that to talk about the mean square of + + align:start position:0% +that to talk about the mean square of + + + align:start position:0% +that to talk about the mean square of +something which is the average of the + + align:start position:0% +something which is the average of the + + + align:start position:0% +something which is the average of the +square of X and the square of Y so for + + align:start position:0% +square of X and the square of Y so for + + + align:start position:0% +square of X and the square of Y so for +example having done that I could say + + align:start position:0% +example having done that I could say + + + align:start position:0% +example having done that I could say +what's the mean square of 2 + 3 and I + + align:start position:0% +what's the mean square of 2 + 3 and I + + + align:start position:0% +what's the mean square of 2 + 3 and I +should get the average of 4 + 9 which is + + align:start position:0% +should get the average of 4 + 9 which is + + + align:start position:0% +should get the average of 4 + 9 which is +6 and 1/2 the key thing here is that + + align:start position:0% +6 and 1/2 the key thing here is that + + + align:start position:0% +6 and 1/2 the key thing here is that +having defined square I can use it as if + + align:start position:0% +having defined square I can use it as if + + + align:start position:0% +having defined square I can use it as if +it were primitive right so if we look + + align:start position:0% +it were primitive right so if we look + + + align:start position:0% +it were primitive right so if we look +here on the slide I look at mean square + + align:start position:0% +here on the slide I look at mean square + + + align:start position:0% +here on the slide I look at mean square +write the person defining mean square + + align:start position:0% +write the person defining mean square + + + align:start position:0% +write the person defining mean square +doesn't have to know at this point + + align:start position:0% +doesn't have to know at this point + + + align:start position:0% +doesn't have to know at this point +whether Square was something built into + + align:start position:0% +whether Square was something built into + + + align:start position:0% +whether Square was something built into +the language or whether it was a + + align:start position:0% +the language or whether it was a + + + align:start position:0% +the language or whether it was a +procedure that was defined and that's + + align:start position:0% +procedure that was defined and that's + + + align:start position:0% +procedure that was defined and that's +key thing in Lisp that you not make + + align:start position:0% +key thing in Lisp that you not make + + + align:start position:0% +key thing in Lisp that you not make +arbitrary distinctions between things + + align:start position:0% +arbitrary distinctions between things + + + align:start position:0% +arbitrary distinctions between things +that happen to be primitive in the + + align:start position:0% +that happen to be primitive in the + + + align:start position:0% +that happen to be primitive in the +language and things that happen to be + + align:start position:0% +language and things that happen to be + + + align:start position:0% +language and things that happen to be +built in person you think that shouldn't + + align:start position:0% +built in person you think that shouldn't + + + align:start position:0% +built in person you think that shouldn't +even have to know so the things you + + align:start position:0% +even have to know so the things you + + + align:start position:0% +even have to know so the things you +construct get used with all the power + + align:start position:0% +construct get used with all the power + + + align:start position:0% +construct get used with all the power +and flexibility as if they were + + align:start position:0% +and flexibility as if they were + + + align:start position:0% +and flexibility as if they were +primitives in fact can drive that home + + align:start position:0% +primitives in fact can drive that home + + + align:start position:0% +primitives in fact can drive that home +by + + align:start position:0% +by + + + align:start position:0% +by +looking on the computer one more time we + + align:start position:0% +looking on the computer one more time we + + + align:start position:0% +looking on the computer one more time we +talked about plus and in fact if I come + + align:start position:0% +talked about plus and in fact if I come + + + align:start position:0% +talked about plus and in fact if I come +here on the computer screen and say what + + align:start position:0% +here on the computer screen and say what + + + align:start position:0% +here on the computer screen and say what +is the value of plus notice what Lisp + + align:start position:0% +is the value of plus notice what Lisp + + + align:start position:0% +is the value of plus notice what Lisp +types out on the bottom there typed that + + align:start position:0% +types out on the bottom there typed that + + + align:start position:0% +types out on the bottom there typed that +compound procedure plus because in this + + align:start position:0% +compound procedure plus because in this + + + align:start position:0% +compound procedure plus because in this +system it turns out that the addition + + align:start position:0% +system it turns out that the addition + + + align:start position:0% +system it turns out that the addition +operator is itself a compound procedure + + align:start position:0% +operator is itself a compound procedure + + + align:start position:0% +operator is itself a compound procedure +and if I didn't just type that in you'd + + align:start position:0% +and if I didn't just type that in you'd + + + align:start position:0% +and if I didn't just type that in you'd +never know that and it wouldn't make any + + align:start position:0% +never know that and it wouldn't make any + + + align:start position:0% +never know that and it wouldn't make any +difference anyway we don't care it's + + align:start position:0% +difference anyway we don't care it's + + + align:start position:0% +difference anyway we don't care it's +below the level of the abstraction that + + align:start position:0% +below the level of the abstraction that + + + align:start position:0% +below the level of the abstraction that +we're dealing with so the key thing is + + align:start position:0% +we're dealing with so the key thing is + + + align:start position:0% +we're dealing with so the key thing is +you cannot tell should not be able to + + align:start position:0% +you cannot tell should not be able to + + + align:start position:0% +you cannot tell should not be able to +tell in general the difference between + + align:start position:0% +tell in general the difference between + + + align:start position:0% +tell in general the difference between +things that are built-in and things that + + align:start position:0% +things that are built-in and things that + + + align:start position:0% +things that are built-in and things that +are compound why is that because the + + align:start position:0% +are compound why is that because the + + + align:start position:0% +are compound why is that because the +things that are compound have an + + align:start position:0% +things that are compound have an + + + align:start position:0% +things that are compound have an +abstraction wrapper wrapped around them + + align:start position:0% +abstraction wrapper wrapped around them + + + align:start position:0% +abstraction wrapper wrapped around them +okay we've seen almost all the elements + + align:start position:0% +okay we've seen almost all the elements + + + align:start position:0% +okay we've seen almost all the elements +of Lisp now there's only one more we + + align:start position:0% +of Lisp now there's only one more we + + + align:start position:0% +of Lisp now there's only one more we +have to look at and that is how to make + + align:start position:0% +have to look at and that is how to make + + + align:start position:0% +have to look at and that is how to make +a case analysis let me show you what I + + align:start position:0% +a case analysis let me show you what I + + + align:start position:0% +a case analysis let me show you what I +mean we might want to think about the + + align:start position:0% +mean we might want to think about the + + + align:start position:0% +mean we might want to think about the +the mathematical definition of the + + align:start position:0% +the mathematical definition of the + + + align:start position:0% +the mathematical definition of the +absolute value functions I might say the + + align:start position:0% +absolute value functions I might say the + + + align:start position:0% +absolute value functions I might say the +absolute value of X is the function + + align:start position:0% +absolute value of X is the function + + + align:start position:0% +absolute value of X is the function +which has the property that it's + + align:start position:0% +which has the property that it's + + + align:start position:0% +which has the property that it's +negative of the X for X less than 0 it's + + align:start position:0% +negative of the X for X less than 0 it's + + + align:start position:0% +negative of the X for X less than 0 it's +0 for X equal to 0 and it's X for X + + align:start position:0% +0 for X equal to 0 and it's X for X + + + align:start position:0% +0 for X equal to 0 and it's X for X +greater than 0 and let's pass a way of + + align:start position:0% +greater than 0 and let's pass a way of + + + align:start position:0% +greater than 0 and let's pass a way of +making case analyses let me define for + + align:start position:0% +making case analyses let me define for + + + align:start position:0% +making case analyses let me define for +you absolute value they define the + + align:start position:0% +you absolute value they define the + + + align:start position:0% +you absolute value they define the +absolute value of X is conditional right + + align:start position:0% +absolute value of X is conditional right + + + align:start position:0% +absolute value of X is conditional right +this means case analysis cond okay if X + + align:start position:0% +this means case analysis cond okay if X + + + align:start position:0% +this means case analysis cond okay if X +is less than 0 the answer is negate X + + align:start position:0% + + + + align:start position:0% + +right what I've written here is a clause + + align:start position:0% +right what I've written here is a clause + + + align:start position:0% +right what I've written here is a clause +this is a this whole thing is a + + align:start position:0% +this is a this whole thing is a + + + align:start position:0% +this is a this whole thing is a +conditional clause and it has two parts + + align:start position:0% +conditional clause and it has two parts + + + align:start position:0% +conditional clause and it has two parts +this part here is a is a predicate or a + + align:start position:0% +this part here is a is a predicate or a + + + align:start position:0% +this part here is a is a predicate or a +condition that's a condition and the + + align:start position:0% +condition that's a condition and the + + + align:start position:0% +condition that's a condition and the +condition is expressed by something + + align:start position:0% +condition is expressed by something + + + align:start position:0% +condition is expressed by something +called a predicate and a predicate and + + align:start position:0% +called a predicate and a predicate and + + + align:start position:0% +called a predicate and a predicate and +Lisp is some sort of thing that returns + + align:start position:0% +Lisp is some sort of thing that returns + + + align:start position:0% +Lisp is some sort of thing that returns +either true or false and you see Lisp + + align:start position:0% +either true or false and you see Lisp + + + align:start position:0% +either true or false and you see Lisp +has a primitive procedure less then that + + align:start position:0% +has a primitive procedure less then that + + + align:start position:0% +has a primitive procedure less then that +tests whether something is true or false + + align:start position:0% +tests whether something is true or false + + + align:start position:0% +tests whether something is true or false +and the other part of a clause is an + + align:start position:0% +and the other part of a clause is an + + + align:start position:0% +and the other part of a clause is an +action or a thing to do in the case + + align:start position:0% +action or a thing to do in the case + + + align:start position:0% +action or a thing to do in the case +where that's true and here what I'm + + align:start position:0% +where that's true and here what I'm + + + align:start position:0% +where that's true and here what I'm +doing is negating X the negation + + align:start position:0% +doing is negating X the negation + + + align:start position:0% +doing is negating X the negation +operator + + align:start position:0% +operator + + + align:start position:0% +operator +well the minus sign and Lisp is a little + + align:start position:0% +well the minus sign and Lisp is a little + + + align:start position:0% +well the minus sign and Lisp is a little +bit funny if there are more than if + + align:start position:0% +bit funny if there are more than if + + + align:start position:0% +bit funny if there are more than if +there are two or more arguments if + + align:start position:0% +there are two or more arguments if + + + align:start position:0% +there are two or more arguments if +there's two arguments and subtract the + + align:start position:0% +there's two arguments and subtract the + + + align:start position:0% +there's two arguments and subtract the +second one from the first we saw that if + + align:start position:0% +second one from the first we saw that if + + + align:start position:0% +second one from the first we saw that if +there's one argument it negates it all + + align:start position:0% +there's one argument it negates it all + + + align:start position:0% +there's one argument it negates it all +right so this corresponds to that and + + align:start position:0% +right so this corresponds to that and + + + align:start position:0% +right so this corresponds to that and +then there's another Cronk laws it says + + align:start position:0% +then there's another Cronk laws it says + + + align:start position:0% +then there's another Cronk laws it says +in the case where X is equal to 0 the + + align:start position:0% +in the case where X is equal to 0 the + + + align:start position:0% +in the case where X is equal to 0 the +answer is 0 and the case where X is + + align:start position:0% +answer is 0 and the case where X is + + + align:start position:0% +answer is 0 and the case where X is +greater than 0 the answer is X close + + align:start position:0% +greater than 0 the answer is X close + + + align:start position:0% +greater than 0 the answer is X close +that Clause close the cond + + align:start position:0% +that Clause close the cond + + + align:start position:0% +that Clause close the cond +close the definition there's a + + align:start position:0% +close the definition there's a + + + align:start position:0% +close the definition there's a +definition of absolute value and you see + + align:start position:0% +definition of absolute value and you see + + + align:start position:0% +definition of absolute value and you see +it's a case analysis that looks very + + align:start position:0% +it's a case analysis that looks very + + + align:start position:0% +it's a case analysis that looks very +much like the case analysis you use in + + align:start position:0% +much like the case analysis you use in + + + align:start position:0% +much like the case analysis you use in +mathematics ok there's a somewhat + + align:start position:0% +mathematics ok there's a somewhat + + + align:start position:0% +mathematics ok there's a somewhat +different way of writing a restricted + + align:start position:0% +different way of writing a restricted + + + align:start position:0% +different way of writing a restricted +case analysis often you have a case + + align:start position:0% +case analysis often you have a case + + + align:start position:0% +case analysis often you have a case +analysis where you only have one case + + align:start position:0% +analysis where you only have one case + + + align:start position:0% +analysis where you only have one case +where you test something and then + + align:start position:0% +where you test something and then + + + align:start position:0% +where you test something and then +depending on whether it's true or false + + align:start position:0% +depending on whether it's true or false + + + align:start position:0% +depending on whether it's true or false +you do something and here's another + + align:start position:0% +you do something and here's another + + + align:start position:0% +you do something and here's another +definition of the absolute value which + + align:start position:0% +definition of the absolute value which + + + align:start position:0% +definition of the absolute value which +looks almost the same which says if X is + + align:start position:0% +looks almost the same which says if X is + + + align:start position:0% +looks almost the same which says if X is +less than 0 the result is negate X + + align:start position:0% +less than 0 the result is negate X + + + align:start position:0% +less than 0 the result is negate X +otherwise the answer is X and we'll be + + align:start position:0% +otherwise the answer is X and we'll be + + + align:start position:0% +otherwise the answer is X and we'll be +using if a lot but again the thing to + + align:start position:0% +using if a lot but again the thing to + + + align:start position:0% +using if a lot but again the thing to +remember is that this form of absolute + + align:start position:0% +remember is that this form of absolute + + + align:start position:0% +remember is that this form of absolute +value that you're looking at here + + align:start position:0% +value that you're looking at here + + + align:start position:0% +value that you're looking at here +and then this one over here that I wrote + + align:start position:0% +and then this one over here that I wrote + + + align:start position:0% +and then this one over here that I wrote +on the board are essentially the same + + align:start position:0% +on the board are essentially the same + + + align:start position:0% +on the board are essentially the same +and if and Condor or whichever way you + + align:start position:0% +and if and Condor or whichever way you + + + align:start position:0% +and if and Condor or whichever way you +like it you can think of con distinct + + align:start position:0% +like it you can think of con distinct + + + align:start position:0% +like it you can think of con distinct +tactic sugar for if or you can think of + + align:start position:0% +tactic sugar for if or you can think of + + + align:start position:0% +tactic sugar for if or you can think of +if as syntactic sugar for con and it + + align:start position:0% +if as syntactic sugar for con and it + + + align:start position:0% +if as syntactic sugar for con and it +doesn't make any difference person + + align:start position:0% +doesn't make any difference person + + + align:start position:0% +doesn't make any difference person +implementing a list system will pick one + + align:start position:0% +implementing a list system will pick one + + + align:start position:0% +implementing a list system will pick one +and implement the other in terms of that + + align:start position:0% +and implement the other in terms of that + + + align:start position:0% +and implement the other in terms of that +and it doesn't matter which one you pick + + align:start position:0% + + + + align:start position:0% + +okay why don't we break now and then + + align:start position:0% +okay why don't we break now and then + + + align:start position:0% +okay why don't we break now and then +take some questions how come sometimes + + align:start position:0% +take some questions how come sometimes + + + align:start position:0% +take some questions how come sometimes +when I write to fine + + align:start position:0% +when I write to fine + + + align:start position:0% +when I write to fine +I put an open paren here and say define + + align:start position:0% +I put an open paren here and say define + + + align:start position:0% +I put an open paren here and say define +open paren something or other and + + align:start position:0% +open paren something or other and + + + align:start position:0% +open paren something or other and +sometimes when I write this I don't put + + align:start position:0% +sometimes when I write this I don't put + + + align:start position:0% +sometimes when I write this I don't put +an open paren okay the answer is this + + align:start position:0% +an open paren okay the answer is this + + + align:start position:0% +an open paren okay the answer is this +particular form of define where you say + + align:start position:0% +particular form of define where you say + + + align:start position:0% +particular form of define where you say +define some expression is this very + + align:start position:0% +define some expression is this very + + + align:start position:0% +define some expression is this very +special thing for defining procedures + + align:start position:0% +special thing for defining procedures + + + align:start position:0% +special thing for defining procedures +but again what it really means is I'm + + align:start position:0% +but again what it really means is I'm + + + align:start position:0% +but again what it really means is I'm +defining the symbol square to be there + + align:start position:0% +defining the symbol square to be there + + + align:start position:0% +defining the symbol square to be there +so way you should think about it is what + + align:start position:0% +so way you should think about it is what + + + align:start position:0% +so way you should think about it is what +to find us is you right to find and the + + align:start position:0% +to find us is you right to find and the + + + align:start position:0% +to find us is you right to find and the +second thing you write is the symbol + + align:start position:0% +second thing you write is the symbol + + + align:start position:0% +second thing you write is the symbol +here no open paren the symbol you're + + align:start position:0% +here no open paren the symbol you're + + + align:start position:0% +here no open paren the symbol you're +defining and what you're defining it to + + align:start position:0% +defining and what you're defining it to + + + align:start position:0% +defining and what you're defining it to +be that's like here and like here that's + + align:start position:0% +be that's like here and like here that's + + + align:start position:0% +be that's like here and like here that's +the sort of the basic way you use define + + align:start position:0% +the sort of the basic way you use define + + + align:start position:0% +the sort of the basic way you use define +and then there's this special syntactic + + align:start position:0% +and then there's this special syntactic + + + align:start position:0% +and then there's this special syntactic +trick which allows you to define + + align:start position:0% +trick which allows you to define + + + align:start position:0% +trick which allows you to define +procedures that look like this so the + + align:start position:0% +procedures that look like this so the + + + align:start position:0% +procedures that look like this so the +difference is it's whether or not you're + + align:start position:0% +difference is it's whether or not you're + + + align:start position:0% +difference is it's whether or not you're +defining a procedure + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +all right well believe it or not you + + align:start position:0% +all right well believe it or not you + + + align:start position:0% +all right well believe it or not you +actually now know enough Lisp to write + + align:start position:0% +actually now know enough Lisp to write + + + align:start position:0% +actually now know enough Lisp to write +essentially any numerical procedure that + + align:start position:0% +essentially any numerical procedure that + + + align:start position:0% +essentially any numerical procedure that +you'd write in a language like Fortran + + align:start position:0% +you'd write in a language like Fortran + + + align:start position:0% +you'd write in a language like Fortran +or basic or whatever essentially any + + align:start position:0% +or basic or whatever essentially any + + + align:start position:0% +or basic or whatever essentially any +other language you probably think that's + + align:start position:0% +other language you probably think that's + + + align:start position:0% +other language you probably think that's +a that's not believable right because + + align:start position:0% +a that's not believable right because + + + align:start position:0% +a that's not believable right because +you know that these languages have + + align:start position:0% +you know that these languages have + + + align:start position:0% +you know that these languages have +things like four statements and and do + + align:start position:0% +things like four statements and and do + + + align:start position:0% +things like four statements and and do +until a while or something but uh we + + align:start position:0% +until a while or something but uh we + + + align:start position:0% +until a while or something but uh we +don't really need any of that fact we're + + align:start position:0% +don't really need any of that fact we're + + + align:start position:0% +don't really need any of that fact we're +not gonna use any of that in this course + + align:start position:0% +not gonna use any of that in this course + + + align:start position:0% +not gonna use any of that in this course +let me let me show you why again looking + + align:start position:0% +let me let me show you why again looking + + + align:start position:0% +let me let me show you why again looking +back at that square root let's go back + + align:start position:0% +back at that square root let's go back + + + align:start position:0% +back at that square root let's go back +to this square root algorithm of Heron + + align:start position:0% +to this square root algorithm of Heron + + + align:start position:0% +to this square root algorithm of Heron +of Alexandria remember what that said it + + align:start position:0% +of Alexandria remember what that said it + + + align:start position:0% +of Alexandria remember what that said it +said to find an approximation to the + + align:start position:0% +said to find an approximation to the + + + align:start position:0% +said to find an approximation to the +square root of x you make a guess you + + align:start position:0% +square root of x you make a guess you + + + align:start position:0% +square root of x you make a guess you +improve that guess by averaging the + + align:start position:0% +improve that guess by averaging the + + + align:start position:0% +improve that guess by averaging the +guess and x over the guess you keep + + align:start position:0% +guess and x over the guess you keep + + + align:start position:0% +guess and x over the guess you keep +improving that until the guess is good + + align:start position:0% +improving that until the guess is good + + + align:start position:0% +improving that until the guess is good +enough and already alluded to the idea + + align:start position:0% +enough and already alluded to the idea + + + align:start position:0% +enough and already alluded to the idea +the idea is that if the initial guess + + align:start position:0% +the idea is that if the initial guess + + + align:start position:0% +the idea is that if the initial guess +that she took if that initial guess was + + align:start position:0% +that she took if that initial guess was + + + align:start position:0% +that she took if that initial guess was +actually equal to the square root of x + + align:start position:0% +actually equal to the square root of x + + + align:start position:0% +actually equal to the square root of x +then G here would be equal to x over G + + align:start position:0% + + + + align:start position:0% + +so if you hit the square root averaging + + align:start position:0% +so if you hit the square root averaging + + + align:start position:0% +so if you hit the square root averaging +them wouldn't change it if the G that + + align:start position:0% +them wouldn't change it if the G that + + + align:start position:0% +them wouldn't change it if the G that +you picked was larger than the square + + align:start position:0% +you picked was larger than the square + + + align:start position:0% +you picked was larger than the square +root of x then x over G will be smaller + + align:start position:0% +root of x then x over G will be smaller + + + align:start position:0% +root of x then x over G will be smaller +than the square root of x so that when + + align:start position:0% +than the square root of x so that when + + + align:start position:0% +than the square root of x so that when +you average G and x over G you get + + align:start position:0% +you average G and x over G you get + + + align:start position:0% +you average G and x over G you get +something in between all right so if you + + align:start position:0% +something in between all right so if you + + + align:start position:0% +something in between all right so if you +pick a G that's that's too small your + + align:start position:0% +pick a G that's that's too small your + + + align:start position:0% +pick a G that's that's too small your +answer will be too large if you pick a G + + align:start position:0% +answer will be too large if you pick a G + + + align:start position:0% +answer will be too large if you pick a G +that's too large if your G is larger + + align:start position:0% +that's too large if your G is larger + + + align:start position:0% +that's too large if your G is larger +than the square root of x and x over G + + align:start position:0% +than the square root of x and x over G + + + align:start position:0% +than the square root of x and x over G +will be smaller than the square root of + + align:start position:0% +will be smaller than the square root of + + + align:start position:0% +will be smaller than the square root of +x so averaging always gives you + + align:start position:0% +x so averaging always gives you + + + align:start position:0% +x so averaging always gives you +something in between and then it's not + + align:start position:0% +something in between and then it's not + + + align:start position:0% +something in between and then it's not +quite trivial but it's it's possible to + + align:start position:0% +quite trivial but it's it's possible to + + + align:start position:0% +quite trivial but it's it's possible to +show that in fact if G misses the square + + align:start position:0% +show that in fact if G misses the square + + + align:start position:0% +show that in fact if G misses the square +root of x by a little bit the average of + + align:start position:0% +root of x by a little bit the average of + + + align:start position:0% +root of x by a little bit the average of +G and x over G will actually keep + + align:start position:0% +G and x over G will actually keep + + + align:start position:0% +G and x over G will actually keep +getting closer to the square root of x + + align:start position:0% +getting closer to the square root of x + + + align:start position:0% +getting closer to the square root of x +so if you keep doing this enough you'll + + align:start position:0% +so if you keep doing this enough you'll + + + align:start position:0% +so if you keep doing this enough you'll +eventually get as close as you want and + + align:start position:0% +eventually get as close as you want and + + + align:start position:0% +eventually get as close as you want and +then there's another fact that you can + + align:start position:0% +then there's another fact that you can + + + align:start position:0% +then there's another fact that you can +always start out this process by using 1 + + align:start position:0% +always start out this process by using 1 + + + align:start position:0% +always start out this process by using 1 +as an initial guess + + align:start position:0% +as an initial guess + + + align:start position:0% +as an initial guess +and always converge to the square root + + align:start position:0% +and always converge to the square root + + + align:start position:0% +and always converge to the square root +of the axe and so that's this method of + + align:start position:0% +of the axe and so that's this method of + + + align:start position:0% +of the axe and so that's this method of +success of the averaging due to Heron of + + align:start position:0% +success of the averaging due to Heron of + + + align:start position:0% +success of the averaging due to Heron of +Alexandria let's uh let's write it and + + align:start position:0% +Alexandria let's uh let's write it and + + + align:start position:0% +Alexandria let's uh let's write it and +Lisp well the central idea is what does + + align:start position:0% +Lisp well the central idea is what does + + + align:start position:0% +Lisp well the central idea is what does +it mean to try a guess for the square + + align:start position:0% +it mean to try a guess for the square + + + align:start position:0% +it mean to try a guess for the square +root of x let's write that + + align:start position:0% +root of x let's write that + + + align:start position:0% +root of x let's write that +so we'll say fine to try a guess for the + + align:start position:0% +so we'll say fine to try a guess for the + + + align:start position:0% +so we'll say fine to try a guess for the +square root of x what do we do we'll say + + align:start position:0% +square root of x what do we do we'll say + + + align:start position:0% +square root of x what do we do we'll say +if the guess is good enough the guess is + + align:start position:0% +if the guess is good enough the guess is + + + align:start position:0% +if the guess is good enough the guess is +good enough to be a guess for the square + + align:start position:0% +good enough to be a guess for the square + + + align:start position:0% +good enough to be a guess for the square +root of x then as an answer we'll take + + align:start position:0% +root of x then as an answer we'll take + + + align:start position:0% +root of x then as an answer we'll take +the guess otherwise we will try the + + align:start position:0% +the guess otherwise we will try the + + + align:start position:0% +the guess otherwise we will try the +improved guess we'll improve that guess + + align:start position:0% +improved guess we'll improve that guess + + + align:start position:0% +improved guess we'll improve that guess +for the square root of x and we'll try + + align:start position:0% +for the square root of x and we'll try + + + align:start position:0% +for the square root of x and we'll try +that as a guess for the square root of x + + align:start position:0% +that as a guess for the square root of x + + + align:start position:0% +that as a guess for the square root of x +close the try close the if close the + + align:start position:0% +close the try close the if close the + + + align:start position:0% +close the try close the if close the +define so that's how we try a guess and + + align:start position:0% +define so that's how we try a guess and + + + align:start position:0% +define so that's how we try a guess and +then the next part of the process said + + align:start position:0% +then the next part of the process said + + + align:start position:0% +then the next part of the process said +in order to compute square roots + + align:start position:0% +in order to compute square roots + + + align:start position:0% +in order to compute square roots +we'll say define to compute the square + + align:start position:0% +we'll say define to compute the square + + + align:start position:0% +we'll say define to compute the square +root of the X we will try one as a guess + + align:start position:0% +root of the X we will try one as a guess + + + align:start position:0% +root of the X we will try one as a guess +for the square root of x well we have to + + align:start position:0% +for the square root of x well we have to + + + align:start position:0% +for the square root of x well we have to +define a couple more things we have to + + align:start position:0% +define a couple more things we have to + + + align:start position:0% +define a couple more things we have to +say how is it guess good enough and how + + align:start position:0% +say how is it guess good enough and how + + + align:start position:0% +say how is it guess good enough and how +do we improve a guess so let's look at + + align:start position:0% +do we improve a guess so let's look at + + + align:start position:0% +do we improve a guess so let's look at +that the algorithm to improve the guess + + align:start position:0% +that the algorithm to improve the guess + + + align:start position:0% +that the algorithm to improve the guess +right to improve a guess for the square + + align:start position:0% +right to improve a guess for the square + + + align:start position:0% +right to improve a guess for the square +root of x we average that was the + + align:start position:0% +root of x we average that was the + + + align:start position:0% +root of x we average that was the +algorithm we average to guess with the + + align:start position:0% +algorithm we average to guess with the + + + align:start position:0% +algorithm we average to guess with the +quotient of dividing X by the guess + + align:start position:0% +quotient of dividing X by the guess + + + align:start position:0% +quotient of dividing X by the guess +all right that's how we improve a guess + + align:start position:0% +all right that's how we improve a guess + + + align:start position:0% +all right that's how we improve a guess +and to tell whether he guess is good + + align:start position:0% +and to tell whether he guess is good + + + align:start position:0% +and to tell whether he guess is good +enough well we have to decide something + + align:start position:0% +enough well we have to decide something + + + align:start position:0% +enough well we have to decide something +let's this is supposed to be a guess for + + align:start position:0% +let's this is supposed to be a guess for + + + align:start position:0% +let's this is supposed to be a guess for +the square root of x so one possible + + align:start position:0% +the square root of x so one possible + + + align:start position:0% +the square root of x so one possible +thing you can do is say when you take + + align:start position:0% +thing you can do is say when you take + + + align:start position:0% +thing you can do is say when you take +that guess and square it do you get + + align:start position:0% +that guess and square it do you get + + + align:start position:0% +that guess and square it do you get +something very close to X for example so + + align:start position:0% +something very close to X for example so + + + align:start position:0% +something very close to X for example so +what that one way to say that is to say + + align:start position:0% +what that one way to say that is to say + + + align:start position:0% +what that one way to say that is to say +I square the guess subtract X from that + + align:start position:0% +I square the guess subtract X from that + + + align:start position:0% +I square the guess subtract X from that +and see if the absolute value of that + + align:start position:0% +and see if the absolute value of that + + + align:start position:0% +and see if the absolute value of that +whole thing is less than some small + + align:start position:0% +whole thing is less than some small + + + align:start position:0% +whole thing is less than some small +number which depends on my purposes + + align:start position:0% +number which depends on my purposes + + + align:start position:0% +number which depends on my purposes +right okay so there's a there's a + + align:start position:0% +right okay so there's a there's a + + + align:start position:0% +right okay so there's a there's a +complete procedure for how to compute + + align:start position:0% +complete procedure for how to compute + + + align:start position:0% +complete procedure for how to compute +the square root of x let's look at the + + align:start position:0% +the square root of x let's look at the + + + align:start position:0% +the square root of x let's look at the +structure of that a little bit all right + + align:start position:0% +structure of that a little bit all right + + + align:start position:0% +structure of that a little bit all right +have the whole thing I have the notion + + align:start position:0% +have the whole thing I have the notion + + + align:start position:0% +have the whole thing I have the notion +of how to how to compute a square root + + align:start position:0% +of how to how to compute a square root + + + align:start position:0% +of how to how to compute a square root +that's some kind of module right that's + + align:start position:0% +that's some kind of module right that's + + + align:start position:0% +that's some kind of module right that's +some kind of black box it's defined in + + align:start position:0% +some kind of black box it's defined in + + + align:start position:0% +some kind of black box it's defined in +terms of right it's defined in terms of + + align:start position:0% +terms of right it's defined in terms of + + + align:start position:0% +terms of right it's defined in terms of +how to try a guess for the square root + + align:start position:0% +how to try a guess for the square root + + + align:start position:0% +how to try a guess for the square root +of x try is to find in terms of well + + align:start position:0% +of x try is to find in terms of well + + + align:start position:0% +of x try is to find in terms of well +telling whether something is good enough + + align:start position:0% +telling whether something is good enough + + + align:start position:0% +telling whether something is good enough +and telling how to improve something so + + align:start position:0% +and telling how to improve something so + + + align:start position:0% +and telling how to improve something so +good enough try us to find in terms of + + align:start position:0% +good enough try us to find in terms of + + + align:start position:0% +good enough try us to find in terms of +good enough and improve and let's see + + align:start position:0% +good enough and improve and let's see + + + align:start position:0% +good enough and improve and let's see +what else I still in Wolfe you'll go + + align:start position:0% +what else I still in Wolfe you'll go + + + align:start position:0% +what else I still in Wolfe you'll go +down this tree good enough was defined + + align:start position:0% +down this tree good enough was defined + + + align:start position:0% +down this tree good enough was defined +in terms of absolute value and square + + align:start position:0% +in terms of absolute value and square + + + align:start position:0% +in terms of absolute value and square +and improve was defined in terms of + + align:start position:0% +and improve was defined in terms of + + + align:start position:0% +and improve was defined in terms of +something called averaging and then some + + align:start position:0% +something called averaging and then some + + + align:start position:0% +something called averaging and then some +other primitive operators so try square + + align:start position:0% +other primitive operators so try square + + + align:start position:0% +other primitive operators so try square +roots defined in terms of try tries to + + align:start position:0% +roots defined in terms of try tries to + + + align:start position:0% +roots defined in terms of try tries to +find in terms of good enough and improve + + align:start position:0% +find in terms of good enough and improve + + + align:start position:0% +find in terms of good enough and improve +but also try itself so try is also + + align:start position:0% +but also try itself so try is also + + + align:start position:0% +but also try itself so try is also +defined in terms of how to try itself + + align:start position:0% +defined in terms of how to try itself + + + align:start position:0% +defined in terms of how to try itself +well that may give you give you some + + align:start position:0% +well that may give you give you some + + + align:start position:0% +well that may give you give you some +problem right here your high school + + align:start position:0% +problem right here your high school + + + align:start position:0% +problem right here your high school +geometry teacher probably told you that + + align:start position:0% +geometry teacher probably told you that + + + align:start position:0% +geometry teacher probably told you that +it's it's naughty to try and define + + align:start position:0% +it's it's naughty to try and define + + + align:start position:0% +it's it's naughty to try and define +things in terms of themselves because it + + align:start position:0% +things in terms of themselves because it + + + align:start position:0% +things in terms of themselves because it +doesn't make sense but that's false + + align:start position:0% +doesn't make sense but that's false + + + align:start position:0% +doesn't make sense but that's false +all right sometimes it makes perfect + + align:start position:0% +all right sometimes it makes perfect + + + align:start position:0% +all right sometimes it makes perfect +sense to defy the things in terms of + + align:start position:0% +sense to defy the things in terms of + + + align:start position:0% +sense to defy the things in terms of +themselves and this is a case and we can + + align:start position:0% +themselves and this is a case and we can + + + align:start position:0% +themselves and this is a case and we can +look at that we can write down what this + + align:start position:0% +look at that we can write down what this + + + align:start position:0% +look at that we can write down what this +means + + align:start position:0% +means + + + align:start position:0% +means +you'd say suppose I ask Lisp what the + + align:start position:0% +you'd say suppose I ask Lisp what the + + + align:start position:0% +you'd say suppose I ask Lisp what the +square root of two is what's the square + + align:start position:0% +square root of two is what's the square + + + align:start position:0% +square root of two is what's the square +root of two mean well that means I try + + align:start position:0% +root of two mean well that means I try + + + align:start position:0% +root of two mean well that means I try +one as a guess for this square root of + + align:start position:0% +one as a guess for this square root of + + + align:start position:0% +one as a guess for this square root of +two right now I look I say gee is is one + + align:start position:0% +two right now I look I say gee is is one + + + align:start position:0% +two right now I look I say gee is is one +a good enough guess for the square root + + align:start position:0% +a good enough guess for the square root + + + align:start position:0% +a good enough guess for the square root +of two and that depends on the test that + + align:start position:0% +of two and that depends on the test that + + + align:start position:0% +of two and that depends on the test that +good enough does and in this case we'll + + align:start position:0% +good enough does and in this case we'll + + + align:start position:0% +good enough does and in this case we'll +do good enough we'll say no one is not a + + align:start position:0% +do good enough we'll say no one is not a + + + align:start position:0% +do good enough we'll say no one is not a +good enough guess for the square root of + + align:start position:0% +good enough guess for the square root of + + + align:start position:0% +good enough guess for the square root of +two so that will reduce to saying I have + + align:start position:0% +two so that will reduce to saying I have + + + align:start position:0% +two so that will reduce to saying I have +to try the improved and improved improve + + align:start position:0% +to try the improved and improved improve + + + align:start position:0% +to try the improved and improved improve +one as a guess for the square root of + + align:start position:0% +one as a guess for the square root of + + + align:start position:0% +one as a guess for the square root of +two and try that as a guess for the + + align:start position:0% +two and try that as a guess for the + + + align:start position:0% +two and try that as a guess for the +square root of two improving one for + + align:start position:0% +square root of two improving one for + + + align:start position:0% +square root of two improving one for +this as a guess for the square root of + + align:start position:0% +this as a guess for the square root of + + + align:start position:0% +this as a guess for the square root of +two means I averaged one and two divided + + align:start position:0% +two means I averaged one and two divided + + + align:start position:0% +two means I averaged one and two divided +by one all right so this is going to be + + align:start position:0% +by one all right so this is going to be + + + align:start position:0% +by one all right so this is going to be +the average this piece here will be the + + align:start position:0% +the average this piece here will be the + + + align:start position:0% +the average this piece here will be the +average of one and the quotient of two + + align:start position:0% +average of one and the quotient of two + + + align:start position:0% +average of one and the quotient of two +by one and so that's that's this piece + + align:start position:0% +by one and so that's that's this piece + + + align:start position:0% +by one and so that's that's this piece +here and I'm going to try right and this + + align:start position:0% +here and I'm going to try right and this + + + align:start position:0% +here and I'm going to try right and this +is 1.5 so this square root of two + + align:start position:0% +is 1.5 so this square root of two + + + align:start position:0% +is 1.5 so this square root of two +reduces to trying one for the square + + align:start position:0% +reduces to trying one for the square + + + align:start position:0% +reduces to trying one for the square +root of two which reduces to trying 1.5 + + align:start position:0% +root of two which reduces to trying 1.5 + + + align:start position:0% +root of two which reduces to trying 1.5 +as a guess for the square root of two + + align:start position:0% +as a guess for the square root of two + + + align:start position:0% +as a guess for the square root of two +all right so that makes that makes sense + + align:start position:0% +all right so that makes that makes sense + + + align:start position:0% +all right so that makes that makes sense +let's look at the rest of the process + + align:start position:0% +let's look at the rest of the process + + + align:start position:0% +let's look at the rest of the process +here if I try 1.5 all right that reduces + + align:start position:0% +here if I try 1.5 all right that reduces + + + align:start position:0% +here if I try 1.5 all right that reduces +1.5 turns out to be not good enough as a + + align:start position:0% +1.5 turns out to be not good enough as a + + + align:start position:0% +1.5 turns out to be not good enough as a +guess for the square root of 2 so that + + align:start position:0% +guess for the square root of 2 so that + + + align:start position:0% +guess for the square root of 2 so that +reduces to trying the average of 1.5 and + + align:start position:0% +reduces to trying the average of 1.5 and + + + align:start position:0% +reduces to trying the average of 1.5 and +2 divided by 1.5 as a guess for the + + align:start position:0% +2 divided by 1.5 as a guess for the + + + align:start position:0% +2 divided by 1.5 as a guess for the +square root of 2 + + align:start position:0% +square root of 2 + + + align:start position:0% +square root of 2 +that average turns out to be one point + + align:start position:0% +that average turns out to be one point + + + align:start position:0% +that average turns out to be one point +three three three so this whole thing + + align:start position:0% +three three three so this whole thing + + + align:start position:0% +three three three so this whole thing +reduces to trying one point three three + + align:start position:0% +reduces to trying one point three three + + + align:start position:0% +reduces to trying one point three three +three is a guess for the square root of + + align:start position:0% +three is a guess for the square root of + + + align:start position:0% +three is a guess for the square root of +two and then so on right that reduces to + + align:start position:0% +two and then so on right that reduces to + + + align:start position:0% +two and then so on right that reduces to +another called a good enough one point + + align:start position:0% +another called a good enough one point + + + align:start position:0% +another called a good enough one point +for something or other and then it keeps + + align:start position:0% +for something or other and then it keeps + + + align:start position:0% +for something or other and then it keeps +going until the process finally stops + + align:start position:0% +going until the process finally stops + + + align:start position:0% +going until the process finally stops +with something that that good enough + + align:start position:0% +with something that that good enough + + + align:start position:0% +with something that that good enough +thinks is good enough which in this case + + align:start position:0% +thinks is good enough which in this case + + + align:start position:0% +thinks is good enough which in this case +is is 1.4142 something or other all + + align:start position:0% +is is 1.4142 something or other all + + + align:start position:0% +is is 1.4142 something or other all +right so the process makes makes perfect + + align:start position:0% +right so the process makes makes perfect + + + align:start position:0% +right so the process makes makes perfect +sense by the way is called a recursive + + align:start position:0% +sense by the way is called a recursive + + + align:start position:0% +sense by the way is called a recursive +definition and the ability to make + + align:start position:0% +definition and the ability to make + + + align:start position:0% +definition and the ability to make +recursive definitions is a source of + + align:start position:0% +recursive definitions is a source of + + + align:start position:0% +recursive definitions is a source of +incredible power and is can already see + + align:start position:0% +incredible power and is can already see + + + align:start position:0% +incredible power and is can already see +I've hinted at it's the thing that + + align:start position:0% +I've hinted at it's the thing that + + + align:start position:0% +I've hinted at it's the thing that +effectively allows you to do these + + align:start position:0% +effectively allows you to do these + + + align:start position:0% +effectively allows you to do these +infinite computations that go on until + + align:start position:0% +infinite computations that go on until + + + align:start position:0% +infinite computations that go on until +something is true right without having + + align:start position:0% +something is true right without having + + + align:start position:0% +something is true right without having +any other constructs other than the + + align:start position:0% +any other constructs other than the + + + align:start position:0% +any other constructs other than the +ability to call a procedure let's see + + align:start position:0% +ability to call a procedure let's see + + + align:start position:0% +ability to call a procedure let's see +there's one more thing that I say let me + + align:start position:0% +there's one more thing that I say let me + + + align:start position:0% +there's one more thing that I say let me +show you a variant of this definition of + + align:start position:0% +show you a variant of this definition of + + + align:start position:0% +show you a variant of this definition of +square root come on the slide here's a + + align:start position:0% +square root come on the slide here's a + + + align:start position:0% +square root come on the slide here's a +here's a sort of the same thing what + + align:start position:0% +here's a sort of the same thing what + + + align:start position:0% +here's a sort of the same thing what +I've done here is packaged the + + align:start position:0% +I've done here is packaged the + + + align:start position:0% +I've done here is packaged the +definitions of improve and good enough + + align:start position:0% +definitions of improve and good enough + + + align:start position:0% +definitions of improve and good enough +and try inside square root so in effect + + align:start position:0% +and try inside square root so in effect + + + align:start position:0% +and try inside square root so in effect +what I've done is I've built a square + + align:start position:0% +what I've done is I've built a square + + + align:start position:0% +what I've done is I've built a square +root box so I built a box that's this + + align:start position:0% +root box so I built a box that's this + + + align:start position:0% +root box so I built a box that's this +square root procedure that someone can + + align:start position:0% +square root procedure that someone can + + + align:start position:0% +square root procedure that someone can +use they might put in 36 and get out six + + align:start position:0% +use they might put in 36 and get out six + + + align:start position:0% +use they might put in 36 and get out six +and then packaged inside this box are + + align:start position:0% +and then packaged inside this box are + + + align:start position:0% +and then packaged inside this box are +the definitions of try and good enough + + align:start position:0% + + + + align:start position:0% + +and improve right so they're hidden + + align:start position:0% +and improve right so they're hidden + + + align:start position:0% +and improve right so they're hidden +inside this box and the reason for doing + + align:start position:0% +inside this box and the reason for doing + + + align:start position:0% +inside this box and the reason for doing +that is that if someone's using the + + align:start position:0% +that is that if someone's using the + + + align:start position:0% +that is that if someone's using the +square root if George is using the + + align:start position:0% +square root if George is using the + + + align:start position:0% +square root if George is using the +square of George probably doesn't care + + align:start position:0% +square of George probably doesn't care + + + align:start position:0% +square of George probably doesn't care +very much that when I implemented square + + align:start position:0% +very much that when I implemented square + + + align:start position:0% +very much that when I implemented square +root I had things inside they're called + + align:start position:0% +root I had things inside they're called + + + align:start position:0% +root I had things inside they're called +try and good enough and improve and in + + align:start position:0% +try and good enough and improve and in + + + align:start position:0% +try and good enough and improve and in +fact Harry might have a cube root + + align:start position:0% +fact Harry might have a cube root + + + align:start position:0% +fact Harry might have a cube root +procedure that has try and good enough + + align:start position:0% +procedure that has try and good enough + + + align:start position:0% +procedure that has try and good enough +and improve and in order to not get the + + align:start position:0% +and improve and in order to not get the + + + align:start position:0% +and improve and in order to not get the +whole system confused would be good for + + align:start position:0% +whole system confused would be good for + + + align:start position:0% +whole system confused would be good for +Harry to package his internal procedures + + align:start position:0% +Harry to package his internal procedures + + + align:start position:0% +Harry to package his internal procedures +inside his cube root procedure way this + + align:start position:0% +inside his cube root procedure way this + + + align:start position:0% +inside his cube root procedure way this +is called block structure this + + align:start position:0% +is called block structure this + + + align:start position:0% +is called block structure this +particular way of packaging internals + + align:start position:0% +particular way of packaging internals + + + align:start position:0% +particular way of packaging internals +inside of a definition and let's go back + + align:start position:0% +inside of a definition and let's go back + + + align:start position:0% +inside of a definition and let's go back +and look at the slide again the way to + + align:start position:0% +and look at the slide again the way to + + + align:start position:0% +and look at the slide again the way to +read this this kind of procedure is to + + align:start position:0% +read this this kind of procedure is to + + + align:start position:0% +read this this kind of procedure is to +say to define square root well inside + + align:start position:0% +say to define square root well inside + + + align:start position:0% +say to define square root well inside +that definition + + align:start position:0% +that definition + + + align:start position:0% +that definition +I'll have the definition of an improve + + align:start position:0% +I'll have the definition of an improve + + + align:start position:0% +I'll have the definition of an improve +and the definition of good enough and + + align:start position:0% +and the definition of good enough and + + + align:start position:0% +and the definition of good enough and +the definition of try and then subject + + align:start position:0% +the definition of try and then subject + + + align:start position:0% +the definition of try and then subject +to those definitions the way I do square + + align:start position:0% +to those definitions the way I do square + + + align:start position:0% +to those definitions the way I do square +root is to try 1 and notice here I don't + + align:start position:0% +root is to try 1 and notice here I don't + + + align:start position:0% +root is to try 1 and notice here I don't +have to say 1 as a guest for the square + + align:start position:0% +have to say 1 as a guest for the square + + + align:start position:0% +have to say 1 as a guest for the square +root of the X because since it's all + + align:start position:0% +root of the X because since it's all + + + align:start position:0% +root of the X because since it's all +inside this square root it sort of has + + align:start position:0% +inside this square root it sort of has + + + align:start position:0% +inside this square root it sort of has +this X known + + align:start position:0% + + + + align:start position:0% + +okay well let me let me summarize we + + align:start position:0% +okay well let me let me summarize we + + + align:start position:0% +okay well let me let me summarize we +started out with the idea that what + + align:start position:0% +started out with the idea that what + + + align:start position:0% +started out with the idea that what +we're going to be doing is expressing + + align:start position:0% +we're going to be doing is expressing + + + align:start position:0% +we're going to be doing is expressing +imperative knowledge and in fact here's + + align:start position:0% +imperative knowledge and in fact here's + + + align:start position:0% +imperative knowledge and in fact here's +a here's a slide that summarizes the way + + align:start position:0% +a here's a slide that summarizes the way + + + align:start position:0% +a here's a slide that summarizes the way +we we looked at lists we started out by + + align:start position:0% +we we looked at lists we started out by + + + align:start position:0% +we we looked at lists we started out by +looking at some primitive elements and + + align:start position:0% +looking at some primitive elements and + + + align:start position:0% +looking at some primitive elements and +addition and multiplication some + + align:start position:0% +addition and multiplication some + + + align:start position:0% +addition and multiplication some +predicates for testing whether + + align:start position:0% +predicates for testing whether + + + align:start position:0% +predicates for testing whether +something's less than or something's + + align:start position:0% +something's less than or something's + + + align:start position:0% +something's less than or something's +equal and in fact we saw a really + + align:start position:0% +equal and in fact we saw a really + + + align:start position:0% +equal and in fact we saw a really +sneakily in the system we're actually + + align:start position:0% +sneakily in the system we're actually + + + align:start position:0% +sneakily in the system we're actually +using these aren't actually primitives + + align:start position:0% +using these aren't actually primitives + + + align:start position:0% +using these aren't actually primitives +but it doesn't matter what matters is + + align:start position:0% +but it doesn't matter what matters is + + + align:start position:0% +but it doesn't matter what matters is +we're going to use them as if they're + + align:start position:0% +we're going to use them as if they're + + + align:start position:0% +we're going to use them as if they're +primitives we're not going to look + + align:start position:0% +primitives we're not going to look + + + align:start position:0% +primitives we're not going to look +inside we also have some primitive data + + align:start position:0% +inside we also have some primitive data + + + align:start position:0% +inside we also have some primitive data +and some numbers we saw some means of + + align:start position:0% +and some numbers we saw some means of + + + align:start position:0% +and some numbers we saw some means of +composition means of combination the + + align:start position:0% +composition means of combination the + + + align:start position:0% +composition means of combination the +basic one being composing functions and + + align:start position:0% +basic one being composing functions and + + + align:start position:0% +basic one being composing functions and +building combinations with operators and + + align:start position:0% +building combinations with operators and + + + align:start position:0% +building combinations with operators and +operands and there were some other + + align:start position:0% +operands and there were some other + + + align:start position:0% +operands and there were some other +things like cond and if and define but + + align:start position:0% +things like cond and if and define but + + + align:start position:0% +things like cond and if and define but +the main thing about define in + + align:start position:0% +the main thing about define in + + + align:start position:0% +the main thing about define in +particular was that it was the means of + + align:start position:0% +particular was that it was the means of + + + align:start position:0% +particular was that it was the means of +abstraction it was the way that we named + + align:start position:0% +abstraction it was the way that we named + + + align:start position:0% +abstraction it was the way that we named +things you can also see from this slide + + align:start position:0% +things you can also see from this slide + + + align:start position:0% +things you can also see from this slide +not only where we've been but holes we + + align:start position:0% +not only where we've been but holes we + + + align:start position:0% +not only where we've been but holes we +have to fill in at some point we'll have + + align:start position:0% +have to fill in at some point we'll have + + + align:start position:0% +have to fill in at some point we'll have +to talk about how you combine primitive + + align:start position:0% +to talk about how you combine primitive + + + align:start position:0% +to talk about how you combine primitive +data to get compound data and how you + + align:start position:0% +data to get compound data and how you + + + align:start position:0% +data to get compound data and how you +abstract data so you can use large globs + + align:start position:0% +abstract data so you can use large globs + + + align:start position:0% +abstract data so you can use large globs +of data as if they were primitive so + + align:start position:0% +of data as if they were primitive so + + + align:start position:0% +of data as if they were primitive so +that's where that's where we're going + + align:start position:0% +that's where that's where we're going + + + align:start position:0% +that's where that's where we're going +but before we do that for the next + + align:start position:0% +but before we do that for the next + + + align:start position:0% +but before we do that for the next +couple of lectures we're going to be + + align:start position:0% +couple of lectures we're going to be + + + align:start position:0% +couple of lectures we're going to be +talking about first of all how it is + + align:start position:0% +talking about first of all how it is + + + align:start position:0% +talking about first of all how it is +that you make a link between these + + align:start position:0% +that you make a link between these + + + align:start position:0% +that you make a link between these +procedures we write and the processes + + align:start position:0% +procedures we write and the processes + + + align:start position:0% +procedures we write and the processes +that happen in the machine and then how + + align:start position:0% +that happen in the machine and then how + + + align:start position:0% +that happen in the machine and then how +it is that you start using the power of + + align:start position:0% +it is that you start using the power of + + + align:start position:0% +it is that you start using the power of +Lisp to talk not only about these + + align:start position:0% +Lisp to talk not only about these + + + align:start position:0% +Lisp to talk not only about these +individual little computations but about + + align:start position:0% +individual little computations but about + + + align:start position:0% +individual little computations but about +general conventional methods of doing + + align:start position:0% +general conventional methods of doing + + + align:start position:0% +general conventional methods of doing +things okay are there any questions yes + + align:start position:0% +things okay are there any questions yes + + + align:start position:0% +things okay are there any questions yes +if we define a using parentheses instead + + align:start position:0% +if we define a using parentheses instead + + + align:start position:0% +if we define a using parentheses instead +of as we did what would be the + + align:start position:0% +of as we did what would be the + + + align:start position:0% +of as we did what would be the +difference if I wrote this if I really + + align:start position:0% +difference if I wrote this if I really + + + align:start position:0% +difference if I wrote this if I really +that what I would be doing is defining a + + align:start position:0% +that what I would be doing is defining a + + + align:start position:0% +that what I would be doing is defining a +procedure named a in this case a + + align:start position:0% +procedure named a in this case a + + + align:start position:0% +procedure named a in this case a +procedure of no arguments + + align:start position:0% +procedure of no arguments + + + align:start position:0% +procedure of no arguments +which one Iran it would give me back + + align:start position:0% +which one Iran it would give me back + + + align:start position:0% +which one Iran it would give me back +five times five I mean you come over the + + align:start position:0% +five times five I mean you come over the + + + align:start position:0% +five times five I mean you come over the +same thing except for you really got a + + align:start position:0% +same thing except for you really got a + + + align:start position:0% +same thing except for you really got a +different right and the difference the + + align:start position:0% +different right and the difference the + + + align:start position:0% +different right and the difference the +difference would be in the old one let + + align:start position:0% +difference would be in the old one let + + + align:start position:0% +difference would be in the old one let +me be a little bit clearer here let's + + align:start position:0% +me be a little bit clearer here let's + + + align:start position:0% +me be a little bit clearer here let's +let's call this a like here and that + + align:start position:0% +let's call this a like here and that + + + align:start position:0% +let's call this a like here and that +pretend here just for contrast + + align:start position:0% +pretend here just for contrast + + + align:start position:0% +pretend here just for contrast +I wrote define D to be the product of + + align:start position:0% +I wrote define D to be the product of + + + align:start position:0% +I wrote define D to be the product of +five and five and the difference between + + align:start position:0% +five and five and the difference between + + + align:start position:0% +five and five and the difference between +those let's think about interactions + + align:start position:0% +those let's think about interactions + + + align:start position:0% +those let's think about interactions +with the Lisp interpreter I would take a + + align:start position:0% +with the Lisp interpreter I would take a + + + align:start position:0% +with the Lisp interpreter I would take a +type in a and list would return twenty + + align:start position:0% +type in a and list would return twenty + + + align:start position:0% +type in a and list would return twenty +five I could type in D if I just type in + + align:start position:0% +five I could type in D if I just type in + + + align:start position:0% +five I could type in D if I just type in +D Lisp would return compound procedure D + + align:start position:0% +D Lisp would return compound procedure D + + + align:start position:0% +D Lisp would return compound procedure D +because that's what it is it's a + + align:start position:0% +because that's what it is it's a + + + align:start position:0% +because that's what it is it's a +procedure I could run D I could say + + align:start position:0% +procedure I could run D I could say + + + align:start position:0% +procedure I could run D I could say +what's the value of running D here is a + + align:start position:0% +what's the value of running D here is a + + + align:start position:0% +what's the value of running D here is a +combination with no operands and I see + + align:start position:0% +combination with no operands and I see + + + align:start position:0% +combination with no operands and I see +there no operands I didn't put any after + + align:start position:0% +there no operands I didn't put any after + + + align:start position:0% +there no operands I didn't put any after +D and it would say oh that's 25 or I + + align:start position:0% +D and it would say oh that's 25 or I + + + align:start position:0% +D and it would say oh that's 25 or I +could say district just for completeness + + align:start position:0% +could say district just for completeness + + + align:start position:0% +could say district just for completeness +if I typed in what's the value of + + align:start position:0% +if I typed in what's the value of + + + align:start position:0% +if I typed in what's the value of +running a I get an error the error would + + align:start position:0% +running a I get an error the error would + + + align:start position:0% +running a I get an error the error would +be the same one as as over there I'd be + + align:start position:0% +be the same one as as over there I'd be + + + align:start position:0% +be the same one as as over there I'd be +the error would say sorry 25 which is + + align:start position:0% +the error would say sorry 25 which is + + + align:start position:0% +the error would say sorry 25 which is +the value of a is not an operator that I + + align:start position:0% +the value of a is not an operator that I + + + align:start position:0% +the value of a is not an operator that I +can apply to something + + align:start position:0% +can apply to something + + + align:start position:0% +can apply to something +[Music] \ No newline at end of file diff --git a/-Zg3fxOmjVs.txt b/-Zg3fxOmjVs.txt new file mode 100644 index 0000000000000000000000000000000000000000..a2e716f15223e43e2772d771152f2185b2cc47fb --- /dev/null +++ b/-Zg3fxOmjVs.txt @@ -0,0 +1,174 @@ +Okay, here's our final contract for how procedure +calls will work: + +The calling procedure ("caller") will +PUSH the argument values onto the stack in + +reverse order +Branch to the entry point of the callee, putting + +the return address into the linkage pointer. + +When the callee returns, remove the argument +values from the stack. + +The called procedure ("callee") will +Perform the promised computation, leaving + +the result in R0. + +Jump to the return address when the computation +has finished + +Remove any items it has placed on the stack, +leaving the stack as it was when the procedure + +was entered. + +Note that the arguments were PUSHed on the +stack by the caller, so it will be up to the + +caller to remove them. + +Preserve the values in all registers except +R0, which holds the return value. + +So the caller can assume any values placed +in registers before a nested call will be + +there when the nested call returns. + +We saw the code template for procedure calls +on an earlier slide. + +Here's the template for the entry point to +a procedure F. + +The code saves the caller's LP and BP values, +initializes BP for the current stack frame + +and allocates words on the stack to hold any +local variable values. + +The final step is to PUSH the value of any +registers (besides R0) that will be used by + +the remainder of the procedure's code. + +The template for the exit sequence mirrors +the actions of the entry sequence, restoring + +all the values saved by the entry sequence, +performing the POP operations in the reverse + +of the order of the PUSH operations in the +entry sequence. + +Note that in moving the BP value into SP we've +reset the stack to its state at the point + +of the MOVE(SP,BP) in the entry sequence. + +This implicitly undoes the effect of the ALLOCATE +statement in the entry sequence, so we don't + +need a matching DEALLOCATE in the exit sequence. + +The last instruction in the exit sequence +transfers control back to the calling procedure. + +With practice you'll become familiar with +these code templates. + +Meanwhile, you can refer back to this slide +whenever you need to generate code for a procedure + +call. + +Here's the code our compiler would generate +for the C implementation of factorial shown + +on the left. + +The entry sequence saves the caller's LP and +BP, then initializes BP for the current stack + +frame. + +The value of R1 is saved so we can use R1 +in code that follows. + +The exit sequence restores all the saved values, +including that for R1. + +The code for the body of the procedure has +arranged for R0 to contain the return value + +by the time execution reaches the exit sequence. + +The nested procedure call passes the argument +value on the stack and removes it after the + +nested call returns. + +The remainder of the code is generated using +the templates we saw in the previous lecture. + +Aside from computing and pushing the values +of the arguments, there are approximately + +10 instructions needed to implement the linking +approach to a procedure call. + +That's not much for a procedure of any size, +but might be significant for a trivial procedure. + +As mentioned earlier, some optimizing compilers +can make the tradeoff of inlining small non-recursive + +procedures saving this small amount of overhead. + +So have we solved the activation record storage +issue for recursive procedures? + +Yes! + +A new stack from is allocated for each procedure +call. + +In each frame we see the storage for the argument +and return address. + +And as the nested calls return the stack frames +will be deallocated in inverse order. + +Interestingly we can learn a lot about the +current state of execution by looking at the + +active stack frames. + +The current value of BP, along the older values +saved in the activation records, allow us + +to identify the active procedure calls and +determine their arguments, the values of any + +local variables for active calls, and so on. + +If we print out all this information at any +given time we would have a "stack trace" showing + +the progress of the computation. + +In fact, when an problem occurs, many language +runtimes will print out that stack trace to + +help the programmer determine what happened. + +And, of course, if you can interpret the information +in the stack frames, you can show you understand + +our conventions for procedure call and return. + +Don't be surprised to find such a question +on a quiz :) \ No newline at end of file diff --git a/-mrxN8XcQOQ.txt b/-mrxN8XcQOQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..b98612427e77e3760d197ca93d564ababa57fa26 --- /dev/null +++ b/-mrxN8XcQOQ.txt @@ -0,0 +1,12735 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay let's start uh so let + + align:start position:0% +ocw.mit.edu okay let's start uh so let + + + align:start position:0% +ocw.mit.edu okay let's start uh so let +me just mention uh brief uh first let me + + align:start position:0% +me just mention uh brief uh first let me + + + align:start position:0% +me just mention uh brief uh first let me +just mention briefly uh this uh story + + align:start position:0% +just mention briefly uh this uh story + + + align:start position:0% +just mention briefly uh this uh story +regarding the de brain + + align:start position:0% +regarding the de brain + + + align:start position:0% +regarding the de brain +and the he + + align:start position:0% +and the he + + + align:start position:0% +and the he +mechanism uh which we uh discussed at + + align:start position:0% +mechanism uh which we uh discussed at + + + align:start position:0% +mechanism uh which we uh discussed at +the end of last lecture so there was a + + align:start position:0% +the end of last lecture so there was a + + + align:start position:0% +the end of last lecture so there was a +pide problem uh which was related to + + align:start position:0% +pide problem uh which was related to + + + align:start position:0% +pide problem uh which was related to +this + + align:start position:0% +this + + + align:start position:0% +this +um yes I expected maybe the P problem + + align:start position:0% +um yes I expected maybe the P problem + + + align:start position:0% +um yes I expected maybe the P problem +was a little bit tough because we did + + align:start position:0% +was a little bit tough because we did + + + align:start position:0% +was a little bit tough because we did +not go to many details uh we did not go + + align:start position:0% +not go to many details uh we did not go + + + align:start position:0% +not go to many details uh we did not go +to many details + + align:start position:0% +to many details + + + align:start position:0% +to many details +um um yeah so in grading we will be very + + align:start position:0% +um um yeah so in grading we will be very + + + align:start position:0% +um um yeah so in grading we will be very +um flexible because we + + align:start position:0% +um flexible because we + + + align:start position:0% +um flexible because we +um um yeah but so let me just say a few + + align:start position:0% +um um yeah but so let me just say a few + + + align:start position:0% +um um yeah but so let me just say a few +more things about that just to make sure + + align:start position:0% +more things about that just to make sure + + + align:start position:0% +more things about that just to make sure +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um yeah so here is the say the the + + align:start position:0% +um yeah so here is the say the the + + + align:start position:0% +um yeah so here is the say the the +action if you have n say if you suppose + + align:start position:0% +action if you have n say if you suppose + + + align:start position:0% +action if you have n say if you suppose +you have n de brains + + align:start position:0% +you have n de brains + + + align:start position:0% +you have n de brains +together and then in such case so this + + align:start position:0% +together and then in such case so this + + + align:start position:0% +together and then in such case so this +is a l effective action for the Mist de + + align:start position:0% +is a l effective action for the Mist de + + + align:start position:0% +is a l effective action for the Mist de +freedom on the D brain so which you have + + align:start position:0% +freedom on the D brain so which you have + + + align:start position:0% +freedom on the D brain so which you have +a gauge field which is a matrix and then + + align:start position:0% +a gauge field which is a matrix and then + + + align:start position:0% +a gauge field which is a matrix and then +you also have a a uh a scalar field a l + + align:start position:0% +you also have a a uh a scalar field a l + + + align:start position:0% +you also have a a uh a scalar field a l +of scalar fields which are also inbi + + align:start position:0% +of scalar fields which are also inbi + + + align:start position:0% +of scalar fields which are also inbi +matrices and the L of scalar field is + + align:start position:0% +matrices and the L of scalar field is + + + align:start position:0% +matrices and the L of scalar field is +the same as number of transverse + + align:start position:0% +the same as number of transverse + + + align:start position:0% +the same as number of transverse +Dimensions okay and we also + + align:start position:0% +Dimensions okay and we also + + + align:start position:0% +Dimensions okay and we also +discussed that the uh the the scalar + + align:start position:0% +discussed that the uh the the scalar + + + align:start position:0% +discussed that the uh the the scalar +Fields can be considered as be as + + align:start position:0% +Fields can be considered as be as + + + align:start position:0% +Fields can be considered as be as +describing the transverse dynamics of + + align:start position:0% +describing the transverse dynamics of + + + align:start position:0% +describing the transverse dynamics of +the brain say say let's consider you + + align:start position:0% +the brain say say let's consider you + + + align:start position:0% +the brain say say let's consider you +have a case of a yeah let's consider you + + align:start position:0% +have a case of a yeah let's consider you + + + align:start position:0% +have a case of a yeah let's consider you +have a single single + + align:start position:0% +have a single single + + + align:start position:0% +have a single single +brain and there's only one trans + + align:start position:0% +brain and there's only one trans + + + align:start position:0% +brain and there's only one trans +Direction say let's call it uh um say + + align:start position:0% +Direction say let's call it uh um say + + + align:start position:0% +Direction say let's call it uh um say +the the five direction there's only one + + align:start position:0% +the the five direction there's only one + + + align:start position:0% +the the five direction there's only one +direction say Five One + + align:start position:0% + + + + align:start position:0% + +Direction then the the essentially + + align:start position:0% +Direction then the the essentially + + + align:start position:0% +Direction then the the essentially +location of the brain then essentially + + align:start position:0% +location of the brain then essentially + + + align:start position:0% +location of the brain then essentially +the expectation value of 51 can be + + align:start position:0% +the expectation value of 51 can be + + + align:start position:0% +the expectation value of 51 can be +considered say yeah suppose this is the + + align:start position:0% +considered say yeah suppose this is the + + + align:start position:0% +considered say yeah suppose this is the +direction of X1 and the corresponding + + align:start position:0% +direction of X1 and the corresponding + + + align:start position:0% +direction of X1 and the corresponding +scal of field is 51 and then then + + align:start position:0% +scal of field is 51 and then then + + + align:start position:0% +scal of field is 51 and then then +expectation value of 51 can be + + align:start position:0% +expectation value of 51 can be + + + align:start position:0% +expectation value of 51 can be +considered as a location of the brain + + align:start position:0% +considered as a location of the brain + + + align:start position:0% +considered as a location of the brain +and and this F is the string which U + + align:start position:0% +and and this F is the string which U + + + align:start position:0% +and and this F is the string which U +ending on this brain and come back to + + align:start position:0% +ending on this brain and come back to + + + align:start position:0% +ending on this brain and come back to +itself + + align:start position:0% +itself + + + align:start position:0% +itself +okay so now let's consider if you have + + align:start position:0% +okay so now let's consider if you have + + + align:start position:0% +okay so now let's consider if you have +two brains uh now consider you have M + + align:start position:0% +two brains uh now consider you have M + + + align:start position:0% +two brains uh now consider you have M +brains again there only one transverse + + align:start position:0% +brains again there only one transverse + + + align:start position:0% +brains again there only one transverse +Direction and I have EMB + + align:start position:0% +Direction and I have EMB + + + align:start position:0% +Direction and I have EMB +braines this one transverse Direction + + align:start position:0% +braines this one transverse Direction + + + align:start position:0% +braines this one transverse Direction +which again this X1 and now you can just + + align:start position:0% +which again this X1 and now you can just + + + align:start position:0% +which again this X1 and now you can just +separate them so now let's consider the + + align:start position:0% +separate them so now let's consider the + + + align:start position:0% +separate them so now let's consider the +process which you separate this embrane + + align:start position:0% +process which you separate this embrane + + + align:start position:0% +process which you separate this embrane +into say completely separate + + align:start position:0% + + + + align:start position:0% + +in different locations say so this is X1 + + align:start position:0% +in different locations say so this is X1 + + + align:start position:0% +in different locations say so this is X1 +X2 to xn okay to + + align:start position:0% +X2 to xn okay to + + + align:start position:0% +X2 to xn okay to +XM so so this situation can be + + align:start position:0% +XM so so this situation can be + + + align:start position:0% +XM so so this situation can be +considered as a situation so in this + + align:start position:0% +considered as a situation so in this + + + align:start position:0% +considered as a situation so in this +case the f is a a f is M byn matrices + + align:start position:0% +case the f is a a f is M byn matrices + + + align:start position:0% +case the f is a a f is M byn matrices +and then this can be considered as five + + align:start position:0% +and then this can be considered as five + + + align:start position:0% +and then this can be considered as five +having a expectation + + align:start position:0% +having a expectation + + + align:start position:0% +having a expectation +value which is only in the diagonal + + align:start position:0% +value which is only in the diagonal + + + align:start position:0% +value which is only in the diagonal +entry + + align:start position:0% + + + + align:start position:0% + +okay which is only in the diagonal + + align:start position:0% +okay which is only in the diagonal + + + align:start position:0% +okay which is only in the diagonal +entry uh uh and each diagonal + + align:start position:0% +entry uh uh and each diagonal + + + align:start position:0% +entry uh uh and each diagonal +entry describes the location of the uh + + align:start position:0% +entry describes the location of the uh + + + align:start position:0% +entry describes the location of the uh +HD brain and it's natural to think that + + align:start position:0% +HD brain and it's natural to think that + + + align:start position:0% +HD brain and it's natural to think that +why this is diagonal entry because the + + align:start position:0% +why this is diagonal entry because the + + + align:start position:0% +why this is diagonal entry because the +diagonal entry describe the string which + + align:start position:0% +diagonal entry describe the string which + + + align:start position:0% +diagonal entry describe the string which +ending on the brain itself okay so this + + align:start position:0% +ending on the brain itself okay so this + + + align:start position:0% +ending on the brain itself okay so this +is one one one one string and this is + + align:start position:0% +is one one one one string and this is + + + align:start position:0% +is one one one one string and this is +two two string and n n string and so the + + align:start position:0% +two two string and n n string and so the + + + align:start position:0% +two two string and n n string and so the +diagonal string uh uh is the excitation + + align:start position:0% +diagonal string uh uh is the excitation + + + align:start position:0% +diagonal string uh uh is the excitation +on the brain itself and the off diagonal + + align:start position:0% +on the brain itself and the off diagonal + + + align:start position:0% +on the brain itself and the off diagonal +corresponding to essentially + + align:start position:0% +corresponding to essentially + + + align:start position:0% +corresponding to essentially +corresponding to excitation between the + + align:start position:0% +corresponding to excitation between the + + + align:start position:0% +corresponding to excitation between the +stream between the brains and so it's + + align:start position:0% +stream between the brains and so it's + + + align:start position:0% +stream between the brains and so it's +natural that the location of the brain + + align:start position:0% +natural that the location of the brain + + + align:start position:0% +natural that the location of the brain +and then just corresponding to the + + align:start position:0% +and then just corresponding to the + + + align:start position:0% +and then just corresponding to the +diagonal INRI okay and so so now we can + + align:start position:0% +diagonal INRI okay and so so now we can + + + align:start position:0% +diagonal INRI okay and so so now we can +generalize to to the general Dimensions + + align:start position:0% +generalize to to the general Dimensions + + + align:start position:0% +generalize to to the general Dimensions +now they more now Suppose there are two + + align:start position:0% +now they more now Suppose there are two + + + align:start position:0% +now they more now Suppose there are two +transverse + + align:start position:0% +transverse + + + align:start position:0% +transverse +Dimensions okay suppose now there are + + align:start position:0% +Dimensions okay suppose now there are + + + align:start position:0% +Dimensions okay suppose now there are +two transverse dimensions me call X1 and + + align:start position:0% +two transverse dimensions me call X1 and + + + align:start position:0% +two transverse dimensions me call X1 and +X2 and then now you have two scal + + align:start position:0% +X2 and then now you have two scal + + + align:start position:0% +X2 and then now you have two scal +Fields so now the story is a little bit + + align:start position:0% +Fields so now the story is a little bit + + + align:start position:0% +Fields so now the story is a little bit +more complicated because when you have + + align:start position:0% +more complicated because when you have + + + align:start position:0% +more complicated because when you have +two transverse directions say if you + + align:start position:0% +two transverse directions say if you + + + align:start position:0% +two transverse directions say if you +have more than two transverse Direction + + align:start position:0% +have more than two transverse Direction + + + align:start position:0% +have more than two transverse Direction +now you have long Tri potential + + align:start position:0% +now you have long Tri potential + + + align:start position:0% +now you have long Tri potential +term and uh and the lot + + align:start position:0% +term and uh and the lot + + + align:start position:0% +term and uh and the lot +configuration say supposed to F have low + + align:start position:0% +configuration say supposed to F have low + + + align:start position:0% +configuration say supposed to F have low +space time dependent than lot of + + align:start position:0% +space time dependent than lot of + + + align:start position:0% +space time dependent than lot of +configuration say the uh so the uh say + + align:start position:0% +configuration say the uh so the uh say + + + align:start position:0% +configuration say the uh so the uh say +the minimum of the potential the must + + align:start position:0% +the minimum of the potential the must + + + align:start position:0% +the minimum of the potential the must +for correspond into the configuration + + align:start position:0% +for correspond into the configuration + + + align:start position:0% +for correspond into the configuration +which the commutator of 5 and 5 b to be + + align:start position:0% +which the commutator of 5 and 5 b to be + + + align:start position:0% +which the commutator of 5 and 5 b to be +zero for for all all say say right now + + align:start position:0% +zero for for all all say say right now + + + align:start position:0% +zero for for all all say say right now +we just two have trans say so we have + + align:start position:0% +we just two have trans say so we have + + + align:start position:0% +we just two have trans say so we have +two transverse directions so we only + + align:start position:0% +two transverse directions so we only + + + align:start position:0% +two transverse directions so we only +have two okay but you can generalize to + + align:start position:0% +have two okay but you can generalize to + + + align:start position:0% +have two okay but you can generalize to +any number of transverse directions okay + + align:start position:0% +any number of transverse directions okay + + + align:start position:0% +any number of transverse directions okay +so that + + align:start position:0% +so that + + + align:start position:0% +so that +means that the five all the five + + align:start position:0% +means that the five all the five + + + align:start position:0% +means that the five all the five +correspond all the scal of field they + + align:start position:0% +correspond all the scal of field they + + + align:start position:0% +correspond all the scal of field they +have to commute with each + + align:start position:0% + + + + align:start position:0% + +other that means they can be + + align:start position:0% +other that means they can be + + + align:start position:0% +other that means they can be +simultaneous + + align:start position:0% +simultaneous + + + align:start position:0% +simultaneous +diagonalized okay that means it be + + align:start position:0% +diagonalized okay that means it be + + + align:start position:0% +diagonalized okay that means it be +simultaneously diagonalized then that + + align:start position:0% +simultaneously diagonalized then that + + + align:start position:0% +simultaneously diagonalized then that +means we can choose a + + align:start position:0% +means we can choose a + + + align:start position:0% +means we can choose a +basis then we can choose a basis say if + + align:start position:0% +basis then we can choose a basis say if + + + align:start position:0% +basis then we can choose a basis say if +I write five the The Collection all the + + align:start position:0% +I write five the The Collection all the + + + align:start position:0% +I write five the The Collection all the +all the + + align:start position:0% + + + + align:start position:0% + +de then I can simultaneous diagonalize + + align:start position:0% +de then I can simultaneous diagonalize + + + align:start position:0% +de then I can simultaneous diagonalize +them and uh and then they have the + + align:start position:0% +them and uh and then they have the + + + align:start position:0% +them and uh and then they have the +following form okay so so each X + + align:start position:0% +following form okay so so each X + + + align:start position:0% +following form okay so so each X +so each X1 corresponding to so each + + align:start position:0% +so each X1 corresponding to so each + + + align:start position:0% +so each X1 corresponding to so each +Vector corresponding to yes say for + + align:start position:0% +Vector corresponding to yes say for + + + align:start position:0% +Vector corresponding to yes say for +example here is X1 yeah I should I use a + + align:start position:0% +example here is X1 yeah I should I use a + + + align:start position:0% +example here is X1 yeah I should I use a +different notation so let me call the + + align:start position:0% +different notation so let me call the + + + align:start position:0% +different notation so let me call the +space time y1 Y 2 and uh and say this is + + align:start position:0% +space time y1 Y 2 and uh and say this is + + + align:start position:0% +space time y1 Y 2 and uh and say this is +X2 Etc so so this defines the + + align:start position:0% +X2 Etc so so this defines the + + + align:start position:0% +X2 Etc so so this defines the +configuration which you have one D brain + + align:start position:0% +configuration which you have one D brain + + + align:start position:0% +configuration which you have one D brain +here and One D brain at this point and + + align:start position:0% +here and One D brain at this point and + + + align:start position:0% +here and One D brain at this point and +at X3 and Etc okay and again it's only + + align:start position:0% +at X3 and Etc okay and again it's only + + + align:start position:0% +at X3 and Etc okay and again it's only +the diagonal inch + + align:start position:0% +the diagonal inch + + + align:start position:0% +the diagonal inch +uh describe the location of the de Brin + + align:start position:0% +uh describe the location of the de Brin + + + align:start position:0% +uh describe the location of the de Brin +the diagonal in describe location of + + align:start position:0% +the diagonal in describe location of + + + align:start position:0% +the diagonal in describe location of +debrin and this because the because they + + align:start position:0% +debrin and this because the because they + + + align:start position:0% +debrin and this because the because they +all diagonal and the commutator is zero + + align:start position:0% +all diagonal and the commutator is zero + + + align:start position:0% +all diagonal and the commutator is zero +and these are the low configurations + + align:start position:0% +and these are the low configurations + + + align:start position:0% +and these are the low configurations +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so this is a very important lesson it + + align:start position:0% +so so this is a very important lesson it + + + align:start position:0% +so so this is a very important lesson it +tells you that even you have a potential + + align:start position:0% +tells you that even you have a potential + + + align:start position:0% +tells you that even you have a potential +still the deeper end you can put it + + align:start position:0% +still the deeper end you can put it + + + align:start position:0% +still the deeper end you can put it +anywhere you want and you have the + + align:start position:0% +anywhere you want and you have the + + + align:start position:0% +anywhere you want and you have the +freedom to put the Deep you don't break + + align:start position:0% +freedom to put the Deep you don't break + + + align:start position:0% +freedom to put the Deep you don't break +translation symmetry + + align:start position:0% +translation symmetry + + + align:start position:0% +translation symmetry +okay uh any more uh any questions on + + align:start position:0% + + + + align:start position:0% + +this of course when you say when the + + align:start position:0% +this of course when you say when the + + + align:start position:0% +this of course when you say when the +scal of field develop expectation such + + align:start position:0% +scal of field develop expectation such + + + align:start position:0% +scal of field develop expectation such +such expectation value and then your + + align:start position:0% +such expectation value and then your + + + align:start position:0% +such expectation value and then your +original you engage symmetry is broken + + align:start position:0% +original you engage symmetry is broken + + + align:start position:0% +original you engage symmetry is broken +and then broken the uh uh broken into + + align:start position:0% +and then broken the uh uh broken into + + + align:start position:0% +and then broken the uh uh broken into +the uh just in the St the + + align:start position:0% +the uh just in the St the + + + align:start position:0% +the uh just in the St the +story um yeah to whatever subgroup + + align:start position:0% +story um yeah to whatever subgroup + + + align:start position:0% +story um yeah to whatever subgroup +Allowed by this um so if all the X1 are + + align:start position:0% +Allowed by this um so if all the X1 are + + + align:start position:0% +Allowed by this um so if all the X1 are +if all of them are are different then + + align:start position:0% +if all of them are are different then + + + align:start position:0% +if all of them are are different then +you only then the remaining just youu + + align:start position:0% +you only then the remaining just youu + + + align:start position:0% +you only then the remaining just youu +one to the power n because now you just + + align:start position:0% +one to the power n because now you just + + + align:start position:0% +one to the power n because now you just +have each brand separated then you just + + align:start position:0% +have each brand separated then you just + + + align:start position:0% +have each brand separated then you just +have to you one to the power n + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +good okay so so now let Let's uh um move + + align:start position:0% +good okay so so now let Let's uh um move + + + align:start position:0% +good okay so so now let Let's uh um move +to new + + align:start position:0% +to new + + + align:start position:0% +to new +stuff so now let's say a little bit + + align:start position:0% +stuff so now let's say a little bit + + + align:start position:0% +stuff so now let's say a little bit +about the difference in Super Screen + + align:start position:0% +about the difference in Super Screen + + + align:start position:0% +about the difference in Super Screen +Theory so what we said so far actually + + align:start position:0% +Theory so what we said so far actually + + + align:start position:0% +Theory so what we said so far actually +applies to De brains in both a bosonic + + align:start position:0% +applies to De brains in both a bosonic + + + align:start position:0% +applies to De brains in both a bosonic +string and in super + + align:start position:0% +string and in super + + + align:start position:0% +string and in super +string so now let's say a little bit + + align:start position:0% +string so now let's say a little bit + + + align:start position:0% +string so now let's say a little bit +more about the + + align:start position:0% + + + + align:start position:0% + +differ + + align:start position:0% +differ + + + align:start position:0% +differ +okay so as we discussed before when we + + align:start position:0% +okay so as we discussed before when we + + + align:start position:0% +okay so as we discussed before when we +quantize the open string that the Deep + + align:start position:0% +quantize the open string that the Deep + + + align:start position:0% +quantize the open string that the Deep +brains in bonic + + align:start position:0% + + + + align:start position:0% + +stream always have a + + align:start position:0% + + + + align:start position:0% + +tum always have a open screen + + align:start position:0% + + + + align:start position:0% + +tum + + align:start position:0% + + + + align:start position:0% + +no matter what deep you have because the + + align:start position:0% +no matter what deep you have because the + + + align:start position:0% +no matter what deep you have because the +as we discussed before the quantization + + align:start position:0% +as we discussed before the quantization + + + align:start position:0% +as we discussed before the quantization +the Zero Point Energy on the stren is + + align:start position:0% +the Zero Point Energy on the stren is + + + align:start position:0% +the Zero Point Energy on the stren is +the same and no matter which dimension + + align:start position:0% +the same and no matter which dimension + + + align:start position:0% +the same and no matter which dimension +of the brain is ETC and you always have + + align:start position:0% +of the brain is ETC and you always have + + + align:start position:0% +of the brain is ETC and you always have +a open string T + + align:start position:0% + + + + align:start position:0% + +here uh attack + + align:start position:0% +here uh attack + + + align:start position:0% +here uh attack +here so that + + align:start position:0% +here so that + + + align:start position:0% +here so that +means as we said before t means that you + + align:start position:0% +means as we said before t means that you + + + align:start position:0% +means as we said before t means that you +are + + align:start position:0% +are + + + align:start position:0% +are +sitting if you have a if you have a + + align:start position:0% +sitting if you have a if you have a + + + align:start position:0% +sitting if you have a if you have a +scale + + align:start position:0% +scale + + + align:start position:0% +scale +fields which have a negative mass square + + align:start position:0% +fields which have a negative mass square + + + align:start position:0% +fields which have a negative mass square +that means you essentially sitting at + + align:start position:0% +that means you essentially sitting at + + + align:start position:0% +that means you essentially sitting at +the top of the potential in the top of + + align:start position:0% +the top of the potential in the top of + + + align:start position:0% +the top of the potential in the top of +some potential and so that's why you get + + align:start position:0% +some potential and so that's why you get + + + align:start position:0% +some potential and so that's why you get +the netive mass square and so that means + + align:start position:0% +the netive mass square and so that means + + + align:start position:0% +the netive mass square and so that means +we have this is unstable + + align:start position:0% + + + + align:start position:0% + +configuration because if you say give + + align:start position:0% +configuration because if you say give + + + align:start position:0% +configuration because if you say give +the tan a little bit of valve then the T + + align:start position:0% +the tan a little bit of valve then the T + + + align:start position:0% +the tan a little bit of valve then the T +want to roll down and then then you move + + align:start position:0% +want to roll down and then then you move + + + align:start position:0% +want to roll down and then then you move +away from this configuration okay + + align:start position:0% +away from this configuration okay + + + align:start position:0% +away from this configuration okay +okay uh you move away from this + + align:start position:0% +okay uh you move away from this + + + align:start position:0% +okay uh you move away from this +configuration + + align:start position:0% +configuration + + + align:start position:0% +configuration +so when you go to super + + align:start position:0% + + + + align:start position:0% + +stream so we also discussed before that + + align:start position:0% +stream so we also discussed before that + + + align:start position:0% +stream so we also discussed before that +for the for the bosonic stram the close + + align:start position:0% +for the for the bosonic stram the close + + + align:start position:0% +for the for the bosonic stram the close +stram sector also has a attack here and + + align:start position:0% +stram sector also has a attack here and + + + align:start position:0% +stram sector also has a attack here and +then you can get rid of those tens by by + + align:start position:0% +then you can get rid of those tens by by + + + align:start position:0% +then you can get rid of those tens by by +going to the Super stream okay so + + align:start position:0% +going to the Super stream okay so + + + align:start position:0% +going to the Super stream okay so +similarly uh uh go going to the Super + + align:start position:0% +similarly uh uh go going to the Super + + + align:start position:0% +similarly uh uh go going to the Super +string the + + align:start position:0% +string the + + + align:start position:0% +string the +difference of certain + + align:start position:0% + + + + align:start position:0% + +Dimensions not for all Dimensions but + + align:start position:0% +Dimensions not for all Dimensions but + + + align:start position:0% +Dimensions not for all Dimensions but +only only for some + + align:start position:0% +only only for some + + + align:start position:0% +only only for some +Dimensions do not have + + align:start position:0% + + + + align:start position:0% + +Tums so they are + + align:start position:0% + + + + align:start position:0% + +stable + + align:start position:0% +stable + + + align:start position:0% +stable +so the lowest modes are just a massless + + align:start position:0% +so the lowest modes are just a massless + + + align:start position:0% +so the lowest modes are just a massless +mode they don't have lactive mass square + + align:start position:0% +mode they don't have lactive mass square + + + align:start position:0% +mode they don't have lactive mass square +modes + + align:start position:0% + + + + align:start position:0% + +okay uh and uh um in + + align:start position:0% + + + + align:start position:0% + +particular in + + align:start position:0% +particular in + + + align:start position:0% +particular in +particular so this I will this is a long + + align:start position:0% +particular so this I will this is a long + + + align:start position:0% +particular so this I will this is a long +story uh this is somewhat long story + + align:start position:0% +story uh this is somewhat long story + + + align:start position:0% +story uh this is somewhat long story +which I will not explain here uh but I + + align:start position:0% +which I will not explain here uh but I + + + align:start position:0% +which I will not explain here uh but I +will just uh make the statement in + + align:start position:0% +will just uh make the statement in + + + align:start position:0% +will just uh make the statement in +particular you you can show that for + + align:start position:0% +particular you you can show that for + + + align:start position:0% +particular you you can show that for +those stable de brains in super string + + align:start position:0% +those stable de brains in super string + + + align:start position:0% +those stable de brains in super string +they always carry a conserved + + align:start position:0% + + + + align:start position:0% + +charge so I will explain where does this + + align:start position:0% +charge so I will explain where does this + + + align:start position:0% +charge so I will explain where does this +conserved charge come from and they + + align:start position:0% +conserved charge come from and they + + + align:start position:0% +conserved charge come from and they +always carry some conserved charge and + + align:start position:0% +always carry some conserved charge and + + + align:start position:0% +always carry some conserved charge and +which which is also a reason why they're + + align:start position:0% +which which is also a reason why they're + + + align:start position:0% +which which is also a reason why they're +stable and the second feature is that + + align:start position:0% +stable and the second feature is that + + + align:start position:0% +stable and the second feature is that +the the world volume Theory + + align:start position:0% + + + + align:start position:0% + +is super + + align:start position:0% + + + + align:start position:0% + +symmetric okay super symmetric so in + + align:start position:0% +symmetric okay super symmetric so in + + + align:start position:0% +symmetric okay super symmetric so in +addition to this + + align:start position:0% + + + + align:start position:0% + +A5 so in addition to this a this a alpha + + align:start position:0% +A5 so in addition to this a this a alpha + + + align:start position:0% +A5 so in addition to this a this a alpha +five we looking at + + align:start position:0% + + + + align:start position:0% + +here so in addition to + + align:start position:0% + + + + align:start position:0% + +Alpha and F A which we already see in + + align:start position:0% +Alpha and F A which we already see in + + + align:start position:0% +Alpha and F A which we already see in +the bosonic Stream there are also M + + align:start position:0% + + + + align:start position:0% + +fans so so the open string excitations + + align:start position:0% +fans so so the open string excitations + + + align:start position:0% +fans so so the open string excitations +also include M + + align:start position:0% + + + + align:start position:0% + +fans uh they also include Mass fans and + + align:start position:0% +fans uh they also include Mass fans and + + + align:start position:0% +fans uh they also include Mass fans and +in particular the the L + + align:start position:0% +in particular the the L + + + align:start position:0% +in particular the the L +Series well of all of them together is a + + align:start position:0% +Series well of all of them together is a + + + align:start position:0% +Series well of all of them together is a +super symmetric version of this it's a + + align:start position:0% +super symmetric version of this it's a + + + align:start position:0% +super symmetric version of this it's a +Super Y series a super symmetric version + + align:start position:0% +Super Y series a super symmetric version + + + align:start position:0% +Super Y series a super symmetric version +of this and it's some kind of Super + + align:start position:0% + + + + align:start position:0% + +Y + + align:start position:0% +Y + + + align:start position:0% +Y +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +we uh so now let me + + align:start position:0% +we uh so now let me + + + align:start position:0% +we uh so now let me +um let me elaborate a little bit on the + + align:start position:0% +um let me elaborate a little bit on the + + + align:start position:0% +um let me elaborate a little bit on the +first point that they carry a conserve + + align:start position:0% +first point that they carry a conserve + + + align:start position:0% +first point that they carry a conserve +chart + + align:start position:0% +chart + + + align:start position:0% +chart +okay now let me mate a little bit on the + + align:start position:0% +okay now let me mate a little bit on the + + + align:start position:0% +okay now let me mate a little bit on the +first + + align:start position:0% +first + + + align:start position:0% +first +point so + + align:start position:0% +point so + + + align:start position:0% +point so +um so let me go to the one elaborate + + align:start position:0% +um so let me go to the one elaborate + + + align:start position:0% +um so let me go to the one elaborate +more on one so let me just remind you + + align:start position:0% +more on one so let me just remind you + + + align:start position:0% +more on one so let me just remind you +again the bosonic part of + + align:start position:0% + + + + align:start position:0% + +the bonic + + align:start position:0% +the bonic + + + align:start position:0% +the bonic +part of + + align:start position:0% + + + + align:start position:0% + +mat closed supering + + align:start position:0% +mat closed supering + + + align:start position:0% +mat closed supering +Spectrum + + align:start position:0% + + + + align:start position:0% + +which we briefly mentioned + + align:start position:0% + + + + align:start position:0% + +before so this is soal the type two + + align:start position:0% +before so this is soal the type two + + + align:start position:0% +before so this is soal the type two +string soal type two string yeah when I + + align:start position:0% +string soal type two string yeah when I + + + align:start position:0% +string soal type two string yeah when I +say the super string I always mean type + + align:start position:0% +say the super string I always mean type + + + align:start position:0% +say the super string I always mean type +two stren + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so if you qu the super string then + + align:start position:0% +so so if you qu the super string then + + + align:start position:0% +so so if you qu the super string then +you find there again you find the + + align:start position:0% +you find there again you find the + + + align:start position:0% +you find there again you find the +metric you find a graviton then you find + + align:start position:0% +metric you find a graviton then you find + + + align:start position:0% +metric you find a graviton then you find +this an symmetric tensor and you find + + align:start position:0% +this an symmetric tensor and you find + + + align:start position:0% +this an symmetric tensor and you find +this scal Fields just as what we did in + + align:start position:0% +this scal Fields just as what we did in + + + align:start position:0% +this scal Fields just as what we did in +the uh in the bonic stream but but there + + align:start position:0% +the uh in the bonic stream but but there + + + align:start position:0% +the uh in the bonic stream but but there +are some additional uh M this + + align:start position:0% +are some additional uh M this + + + align:start position:0% +are some additional uh M this +mode depending on your conation or how + + align:start position:0% +mode depending on your conation or how + + + align:start position:0% +mode depending on your conation or how +you treat the fance in the super string + + align:start position:0% +you treat the fance in the super string + + + align:start position:0% +you treat the fance in the super string +then there can be say 2 a or 2 + + align:start position:0% +then there can be say 2 a or 2 + + + align:start position:0% +then there can be say 2 a or 2 +B there two type of super string and one + + align:start position:0% +B there two type of super string and one + + + align:start position:0% +B there two type of super string and one +and and for 2 a you have one additional + + align:start position:0% +and and for 2 a you have one additional + + + align:start position:0% +and and for 2 a you have one additional +one form field and additional three form + + align:start position:0% +one form field and additional three form + + + align:start position:0% +one form field and additional three form +field + + align:start position:0% +field + + + align:start position:0% +field +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh and for 2B you have additional Scala + + align:start position:0% +uh and for 2B you have additional Scala + + + align:start position:0% +uh and for 2B you have additional Scala +field and additional two form + + align:start position:0% +field and additional two form + + + align:start position:0% +field and additional two form +field and additional four form + + align:start position:0% + + + + align:start position:0% + +field + + align:start position:0% +field + + + align:start position:0% +field +okay in + + align:start position:0% +okay in + + + align:start position:0% +okay in +particular this is so- called + + align:start position:0% +particular this is so- called + + + align:start position:0% +particular this is so- called +selfdual I will explain that a little + + align:start position:0% +selfdual I will explain that a little + + + align:start position:0% +selfdual I will explain that a little +bit in the 2B container sa du for + + align:start position:0% + + + + align:start position:0% + +form and + + align:start position:0% +form and + + + align:start position:0% +form and +this this additional field are called + + align:start position:0% +this this additional field are called + + + align:start position:0% +this this additional field are called +the raon remon field typically just a l + + align:start position:0% +the raon remon field typically just a l + + + align:start position:0% +the raon remon field typically just a l +called raon remon + + align:start position:0% +called raon remon + + + align:start position:0% +called raon remon +field and so this are called field + + align:start position:0% +field and so this are called field + + + align:start position:0% +field and so this are called field +okay uh C1 C3 uh C1 and C3 that's right + + align:start position:0% +okay uh C1 C3 uh C1 and C3 that's right + + + align:start position:0% +okay uh C1 C3 uh C1 and C3 that's right +they all called one field + + align:start position:0% + + + + align:start position:0% + +yeah so the story is essentially the + + align:start position:0% +yeah so the story is essentially the + + + align:start position:0% +yeah so the story is essentially the +same very similar as what we did for the + + align:start position:0% +same very similar as what we did for the + + + align:start position:0% +same very similar as what we did for the +bosonic string for the bosonic string + + align:start position:0% +bosonic string for the bosonic string + + + align:start position:0% +bosonic string for the bosonic string +you only have + + align:start position:0% +you only have + + + align:start position:0% +you only have +X on worksheet when you quantize X then + + align:start position:0% +X on worksheet when you quantize X then + + + align:start position:0% +X on worksheet when you quantize X then +you find the graviton you find the dot b + + align:start position:0% +you find the graviton you find the dot b + + + align:start position:0% +you find the graviton you find the dot b +you find the five and in the super + + align:start position:0% +you find the five and in the super + + + align:start position:0% +you find the five and in the super +string you put some additional fans on + + align:start position:0% +string you put some additional fans on + + + align:start position:0% +string you put some additional fans on +the worksheet and those fans give you + + align:start position:0% +the worksheet and those fans give you + + + align:start position:0% +the worksheet and those fans give you +additional modes and then you will uh + + align:start position:0% +additional modes and then you will uh + + + align:start position:0% +additional modes and then you will uh +have those additional uh that will also + + align:start position:0% +have those additional uh that will also + + + align:start position:0% +have those additional uh that will also +give rise to additional Mist modes in + + align:start position:0% +give rise to additional Mist modes in + + + align:start position:0% +give rise to additional Mist modes in +the SpaceTime and uh and those are this + + align:start position:0% +the SpaceTime and uh and those are this + + + align:start position:0% +the SpaceTime and uh and those are this +remon Fields okay um also there are they + + align:start position:0% +remon Fields okay um also there are they + + + align:start position:0% +remon Fields okay um also there are they +also Mass this fans which I we not right + + align:start position:0% +also Mass this fans which I we not right + + + align:start position:0% +also Mass this fans which I we not right +here yes so why is it the type 2 a and + + align:start position:0% +here yes so why is it the type 2 a and + + + align:start position:0% +here yes so why is it the type 2 a and +type 2 b string theory they appear to be + + align:start position:0% +type 2 b string theory they appear to be + + + align:start position:0% +type 2 b string theory they appear to be +very very different which seems bad it + + align:start position:0% +very very different which seems bad it + + + align:start position:0% +very very different which seems bad it +just seems like there's this arbitrary + + align:start position:0% +just seems like there's this arbitrary + + + align:start position:0% +just seems like there's this arbitrary +choice about how you go about doing the + + align:start position:0% +choice about how you go about doing the + + + align:start position:0% +choice about how you go about doing the +mathematics and you get this spectrum of + + align:start position:0% +mathematics and you get this spectrum of + + + align:start position:0% +mathematics and you get this spectrum of +particles or the Spectrum so how do you + + align:start position:0% +particles or the Spectrum so how do you + + + align:start position:0% +particles or the Spectrum so how do you +get around this problem + + align:start position:0% +get around this problem + + + align:start position:0% +get around this problem +um this is not the problem this is a + + align:start position:0% +um this is not the problem this is a + + + align:start position:0% +um this is not the problem this is a +fact of + + align:start position:0% +fact of + + + align:start position:0% +fact of +life um okay this is just what you + + align:start position:0% +life um okay this is just what you + + + align:start position:0% +life um okay this is just what you +find this is just what you find so which + + align:start position:0% +find this is just what you find so which + + + align:start position:0% +find this is just what you find so which +one is + + align:start position:0% +one is + + + align:start position:0% +one is +right uh uh + + align:start position:0% +right uh uh + + + align:start position:0% +right uh uh +um + + align:start position:0% + + + + align:start position:0% + +um they both can be right and they both + + align:start position:0% +um they both can be right and they both + + + align:start position:0% +um they both can be right and they both +can be wrong and uh and our our goal + + align:start position:0% +can be wrong and uh and our our goal + + + align:start position:0% +can be wrong and uh and our our goal +just to find all possible theories are + + align:start position:0% +just to find all possible theories are + + + align:start position:0% +just to find all possible theories are +there and uh and and these are just a + + align:start position:0% +there and uh and and these are just a + + + align:start position:0% +there and uh and and these are just a +loud + + align:start position:0% +loud + + + align:start position:0% +loud +quantizations a lot consistent + + align:start position:0% +quantizations a lot consistent + + + align:start position:0% +quantizations a lot consistent +quantizations okay yeah and and both + + align:start position:0% +quantizations okay yeah and and both + + + align:start position:0% +quantizations okay yeah and and both +both of them give you consistent quantum + + align:start position:0% +both of them give you consistent quantum + + + align:start position:0% +both of them give you consistent quantum +gravity and uh if I have time if this is + + align:start position:0% +gravity and uh if I have time if this is + + + align:start position:0% +gravity and uh if I have time if this is +a stren three class If This Were a stren + + align:start position:0% +a stren three class If This Were a stren + + + align:start position:0% +a stren three class If This Were a stren +class then I would explain that actually + + align:start position:0% +class then I would explain that actually + + + align:start position:0% +class then I would explain that actually +uh secretly they are equivalent + + align:start position:0% +uh secretly they are equivalent + + + align:start position:0% +uh secretly they are equivalent +SEC they equivalent okay and uh um yeah + + align:start position:0% +SEC they equivalent okay and uh um yeah + + + align:start position:0% +SEC they equivalent okay and uh um yeah +so so in some sense uh they're not that + + align:start position:0% +so so in some sense uh they're not that + + + align:start position:0% +so so in some sense uh they're not that +different I see yeah + + align:start position:0% + + + + align:start position:0% + +yeah okay anyway for our purpose at the + + align:start position:0% +yeah okay anyway for our purpose at the + + + align:start position:0% +yeah okay anyway for our purpose at the +perative level uh uh when we consider + + align:start position:0% +perative level uh uh when we consider + + + align:start position:0% +perative level uh uh when we consider +the coupling string coupling to be small + + align:start position:0% +the coupling string coupling to be small + + + align:start position:0% +the coupling string coupling to be small +then then they appear to be different + + align:start position:0% +then then they appear to be different + + + align:start position:0% +then then they appear to be different +uh and yeah we have two type of stren + + align:start position:0% +uh and yeah we have two type of stren + + + align:start position:0% +uh and yeah we have two type of stren +here okay and let me mention a little + + align:start position:0% +here okay and let me mention a little + + + align:start position:0% +here okay and let me mention a little +bit those forms so this all these are + + align:start position:0% +bit those forms so this all these are + + + align:start position:0% +bit those forms so this all these are +anti- symmetric + + align:start position:0% +anti- symmetric + + + align:start position:0% +anti- symmetric +potentials so this anti symmetric + + align:start position:0% + + + + align:start position:0% + +potentials are + + align:start position:0% + + + + align:start position:0% + +generations of the uh of the ma Max real + + align:start position:0% + + + + align:start position:0% + +field the max real field a + + align:start position:0% +field the max real field a + + + align:start position:0% +field the max real field a +mu + + align:start position:0% +mu + + + align:start position:0% +mu +okay so so mathematically you can write + + align:start position:0% +okay so so mathematically you can write + + + align:start position:0% +okay so so mathematically you can write +the uh uh uh say for example + + align:start position:0% +the uh uh uh say for example + + + align:start position:0% +the uh uh uh say for example +mathematically you can write the gauge + + align:start position:0% +mathematically you can write the gauge + + + align:start position:0% +mathematically you can write the gauge +field a + + align:start position:0% +field a + + + align:start position:0% +field a +mu as a so-called one + + align:start position:0% +mu as a so-called one + + + align:start position:0% +mu as a so-called one +form so-called one form and a mu is just + + align:start position:0% +form so-called one form and a mu is just + + + align:start position:0% +form so-called one form and a mu is just +coecient of this one form and then and + + align:start position:0% +coecient of this one form and then and + + + align:start position:0% +coecient of this one form and then and +then the field strings is just the + + align:start position:0% +then the field strings is just the + + + align:start position:0% +then the field strings is just the +derivative is just exterior derivative + + align:start position:0% +derivative is just exterior derivative + + + align:start position:0% +derivative is just exterior derivative +of this one + + align:start position:0% +of this one + + + align:start position:0% +of this one +form and then the uh + + align:start position:0% +form and then the uh + + + align:start position:0% +form and then the uh +Lin will be just minus one quarter F mu + + align:start position:0% +Lin will be just minus one quarter F mu + + + align:start position:0% +Lin will be just minus one quarter F mu +mu F mu mu okay construct from this uh + + align:start position:0% +mu F mu mu okay construct from this uh + + + align:start position:0% +mu F mu mu okay construct from this uh +procedure + + align:start position:0% +procedure + + + align:start position:0% +procedure +okay so you can just gener + + align:start position:0% +okay so you can just gener + + + align:start position:0% +okay so you can just gener +mathematically straightforward to + + align:start position:0% +mathematically straightforward to + + + align:start position:0% +mathematically straightforward to +generalize this to higher dimensional + + align:start position:0% +generalize this to higher dimensional + + + align:start position:0% +generalize this to higher dimensional +forms so for example we can consider n + + align:start position:0% +forms so for example we can consider n + + + align:start position:0% +forms so for example we can consider n +form which is the uh n component + + align:start position:0% +form which is the uh n component + + + align:start position:0% +form which is the uh n component +tensor + + align:start position:0% +tensor + + + align:start position:0% +tensor +but all indices are fully antisymmetric + + align:start position:0% +but all indices are fully antisymmetric + + + align:start position:0% +but all indices are fully antisymmetric +with each + + align:start position:0% + + + + align:start position:0% + +other okay so all the indices are fully + + align:start position:0% +other okay so all the indices are fully + + + align:start position:0% +other okay so all the indices are fully +an symmetric with each other so this are + + align:start position:0% +an symmetric with each other so this are + + + align:start position:0% +an symmetric with each other so this are +fully + + align:start position:0% + + + + align:start position:0% + +antisymmetric okay depend on the + + align:start position:0% +antisymmetric okay depend on the + + + align:start position:0% +antisymmetric okay depend on the +convention sometimes we also put the one + + align:start position:0% +convention sometimes we also put the one + + + align:start position:0% +convention sometimes we also put the one +over factorial here okay + + align:start position:0% +over factorial here okay + + + align:start position:0% +over factorial here okay +anyway um so so you can Define such + + align:start position:0% +anyway um so so you can Define such + + + align:start position:0% +anyway um so so you can Define such +object such the generation of a and the + + align:start position:0% +object such the generation of a and the + + + align:start position:0% +object such the generation of a and the +corresponding fi strings for this + + align:start position:0% +corresponding fi strings for this + + + align:start position:0% +corresponding fi strings for this +C we also call + + align:start position:0% +C we also call + + + align:start position:0% +C we also call +F so we + + align:start position:0% +F so we + + + align:start position:0% +F so we +call so the F strength for C is just a m + + align:start position:0% +call so the F strength for C is just a m + + + align:start position:0% +call so the F strength for C is just a m +plus one form which is exterior + + align:start position:0% +plus one form which is exterior + + + align:start position:0% +plus one form which is exterior +derivative of + + align:start position:0% +derivative of + + + align:start position:0% +derivative of +DC okay and then this is n plus one form + + align:start position:0% +DC okay and then this is n plus one form + + + align:start position:0% +DC okay and then this is n plus one form +again this is a fully antisymmetric + + align:start position:0% +again this is a fully antisymmetric + + + align:start position:0% +again this is a fully antisymmetric +tensor now with n plus y indices okay + + align:start position:0% +tensor now with n plus y indices okay + + + align:start position:0% +tensor now with n plus y indices okay +and then you can write down your + + align:start position:0% +and then you can write down your + + + align:start position:0% +and then you can write down your +L similarly by by generalizing this you + + align:start position:0% +L similarly by by generalizing this you + + + align:start position:0% +L similarly by by generalizing this you +can write as one + + align:start position:0% +can write as one + + + align:start position:0% +can write as one +over maybe let me write it here can + + align:start position:0% +over maybe let me write it here can + + + align:start position:0% +over maybe let me write it here can +write it the grin as - 1/ half time M + + align:start position:0% + + + + align:start position:0% + +factorial 2 * m factorial not 2 m + + align:start position:0% +factorial 2 * m factorial not 2 m + + + align:start position:0% +factorial 2 * m factorial not 2 m +factorial 2 * m factorial f 1 mu + + + align:start position:0% +factorial 2 * m factorial f 1 mu + + + + align:start position:0% +factorial 2 * m factorial f 1 mu + +1 F mu1 mu + 1 okay so f is a two form f + + align:start position:0% +1 F mu1 mu + 1 okay so f is a two form f + + + align:start position:0% +1 F mu1 mu + 1 okay so f is a two form f +is M plus one form so so it's a tensor + + align:start position:0% +is M plus one form so so it's a tensor + + + align:start position:0% +is M plus one form so so it's a tensor +with M plus one indices a fully anti + + align:start position:0% +with M plus one indices a fully anti + + + align:start position:0% +with M plus one indices a fully anti +symmetric symmetric under those + + align:start position:0% + + + + align:start position:0% + +fields so so those field essentially + + align:start position:0% +fields so so those field essentially + + + align:start position:0% +fields so so those field essentially +have this kind of structure okay + + align:start position:0% +have this kind of structure okay + + + align:start position:0% +have this kind of structure okay +essentially have this kind of structure + + align:start position:0% +essentially have this kind of structure + + + align:start position:0% +essentially have this kind of structure +and uh say the one form is is very + + align:start position:0% +and uh say the one form is is very + + + align:start position:0% +and uh say the one form is is very +similar to our Max well so this is a + + align:start position:0% +similar to our Max well so this is a + + + align:start position:0% +similar to our Max well so this is a +three form and this is a + + align:start position:0% +three form and this is a + + + align:start position:0% +three form and this is a +scaler then just a massive scaler then + + align:start position:0% +scaler then just a massive scaler then + + + align:start position:0% +scaler then just a massive scaler then +this is a two form whose failed strength + + align:start position:0% +this is a two form whose failed strength + + + align:start position:0% +this is a two form whose failed strength +will be a three form and then this is a + + align:start position:0% +will be a three form and then this is a + + + align:start position:0% +will be a three form and then this is a +four form such + + align:start position:0% + + + + align:start position:0% + +okay and just by + + align:start position:0% +okay and just by + + + align:start position:0% +okay and just by +definition just + + align:start position:0% +definition just + + + align:start position:0% +definition just +like here there's a gauge symmetry + + align:start position:0% +like here there's a gauge symmetry + + + align:start position:0% +like here there's a gauge symmetry +because F equal to + + align:start position:0% +because F equal to + + + align:start position:0% +because F equal to +Da here because this is f equal to DC so + + align:start position:0% +Da here because this is f equal to DC so + + + align:start position:0% +Da here because this is f equal to DC so +there's a gauge + + align:start position:0% + + + + align:start position:0% + +symmetry because I can add + + align:start position:0% +symmetry because I can add + + + align:start position:0% +symmetry because I can add +CN the total + + align:start position:0% +CN the total + + + align:start position:0% +CN the total +derivative of n n +1 n minus one + + align:start position:0% +derivative of n n +1 n minus one + + + align:start position:0% +derivative of n n +1 n minus one +form okay so I can make a gug symmetry + + align:start position:0% +form okay so I can make a gug symmetry + + + align:start position:0% +form okay so I can make a gug symmetry +so so so Lambda n minus one can be n m + + align:start position:0% +so so so Lambda n minus one can be n m + + + align:start position:0% +so so so Lambda n minus one can be n m +minus y + + align:start position:0% + + + + align:start position:0% + +form + + align:start position:0% +form + + + align:start position:0% +form +and because of this Square equal to + + align:start position:0% +and because of this Square equal to + + + align:start position:0% +and because of this Square equal to +zero then f is in wariant okay so FN + + align:start position:0% +zero then f is in wariant okay so FN + + + align:start position:0% +zero then f is in wariant okay so FN +plus one is in + + align:start position:0% + + + + align:start position:0% + +wariant so if you put this into here and + + align:start position:0% +wariant so if you put this into here and + + + align:start position:0% +wariant so if you put this into here and +because this is the because this is + + align:start position:0% +because this is the because this is + + + align:start position:0% +because this is the because this is +already a total derivative and so so f + + align:start position:0% +already a total derivative and so so f + + + align:start position:0% +already a total derivative and so so f +is + + align:start position:0% + + + + align:start position:0% + +invariant + + align:start position:0% +invariant + + + align:start position:0% +invariant +um so uh + + align:start position:0% + + + + align:start position:0% + +so there's a gauge symmetry then there + + align:start position:0% +so there's a gauge symmetry then there + + + align:start position:0% +so there's a gauge symmetry then there +will be a conserved charge say + + align:start position:0% +will be a conserved charge say + + + align:start position:0% +will be a conserved charge say +associated with those M forms okay uh uh + + align:start position:0% +associated with those M forms okay uh uh + + + align:start position:0% +associated with those M forms okay uh uh +you can Define conserve charge associate + + align:start position:0% +you can Define conserve charge associate + + + align:start position:0% +you can Define conserve charge associate +with those M + + align:start position:0% + + + + align:start position:0% + +forms so so far any + + align:start position:0% +forms so so far any + + + align:start position:0% +forms so so far any +questions so yes maybe so this C field + + align:start position:0% +questions so yes maybe so this C field + + + align:start position:0% +questions so yes maybe so this C field +does it denote Firs or B B it's all + + align:start position:0% +does it denote Firs or B B it's all + + + align:start position:0% +does it denote Firs or B B it's all +bosons that uh it + + align:start position:0% +bosons that uh it + + + align:start position:0% +bosons that uh it +looks so this anti symmetric has nothing + + align:start position:0% +looks so this anti symmetric has nothing + + + align:start position:0% +looks so this anti symmetric has nothing +to do with form no uh this just the + + align:start position:0% +to do with form no uh this just the + + + align:start position:0% +to do with form no uh this just the +indices this just indices which is + + align:start position:0% +indices this just indices which is + + + align:start position:0% +indices this just indices which is +symmetric this is not the uh this is not + + align:start position:0% +symmetric this is not the uh this is not + + + align:start position:0% +symmetric this is not the uh this is not +the uh location SpaceTime location yeah + + align:start position:0% +the uh location SpaceTime location yeah + + + align:start position:0% +the uh location SpaceTime location yeah +this just + + align:start position:0% +this just + + + align:start position:0% +this just +indices it's the same thing as in F mu + + align:start position:0% +indices it's the same thing as in F mu + + + align:start position:0% +indices it's the same thing as in F mu +in F mu the IND this anti symmetric yeah + + align:start position:0% +in F mu the IND this anti symmetric yeah + + + align:start position:0% +in F mu the IND this anti symmetric yeah +it's the same thing + + align:start position:0% +it's the same thing + + + align:start position:0% +it's the same thing +here + + align:start position:0% +here + + + align:start position:0% +here +and are people comfortable with this + + align:start position:0% +and are people comfortable with this + + + align:start position:0% +and are people comfortable with this +differential form + + align:start position:0% +differential form + + + align:start position:0% +differential form +rotation + + align:start position:0% + + + + align:start position:0% + +yes B sounds they're all B + + align:start position:0% + + + + align:start position:0% + +sounds sorry h and f are where are their + + align:start position:0% +sounds sorry h and f are where are their + + + align:start position:0% +sounds sorry h and f are where are their +supern oh the super part I did not write + + align:start position:0% +supern oh the super part I did not write + + + align:start position:0% +supern oh the super part I did not write +them down so they are also fonics they + + align:start position:0% +them down so they are also fonics they + + + align:start position:0% +them down so they are also fonics they +also M + + align:start position:0% + + + + align:start position:0% + +Fons yeah we will not worry we will not + + align:start position:0% +Fons yeah we will not worry we will not + + + align:start position:0% +Fons yeah we will not worry we will not +need to worry about them so there are M + + align:start position:0% +need to worry about them so there are M + + + align:start position:0% +need to worry about them so there are M +fans in + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +right yeah just come from uh because uh + + align:start position:0% +right yeah just come from uh because uh + + + align:start position:0% +right yeah just come from uh because uh +um when you go to super string you have + + align:start position:0% +um when you go to super string you have + + + align:start position:0% +um when you go to super string you have +additional Fons on the worksheet and + + align:start position:0% +additional Fons on the worksheet and + + + align:start position:0% +additional Fons on the worksheet and +then they can give you additional uh + + align:start position:0% +then they can give you additional uh + + + align:start position:0% +then they can give you additional uh +masses modes essentially come from + + align:start position:0% +masses modes essentially come from + + + align:start position:0% +masses modes essentially come from +them yeah the + + align:start position:0% +them yeah the + + + align:start position:0% +them yeah the +story the real story is a littleit more + + align:start position:0% +story the real story is a littleit more + + + align:start position:0% +story the real story is a littleit more +complicated because actually in the + + align:start position:0% +complicated because actually in the + + + align:start position:0% +complicated because actually in the +super string even those come from those + + align:start position:0% +super string even those come from those + + + align:start position:0% +super string even those come from those +Fons War sheet Fons yeah but anyway uh + + align:start position:0% +Fons War sheet Fons yeah but anyway uh + + + align:start position:0% +Fons War sheet Fons yeah but anyway uh +because you have add fance to the W + + align:start position:0% +because you have add fance to the W + + + align:start position:0% +because you have add fance to the W +sheet then you have more more + + align:start position:0% +sheet then you have more more + + + align:start position:0% +sheet then you have more more +possibilities than that give rise to + + align:start position:0% +possibilities than that give rise to + + + align:start position:0% +possibilities than that give rise to +those modes yeah that's the r story that + + align:start position:0% +those modes yeah that's the r story that + + + align:start position:0% +those modes yeah that's the r story that +modes are also for bz not for FS no + + align:start position:0% +modes are also for bz not for FS no + + + align:start position:0% +modes are also for bz not for FS no +these + + align:start position:0% +these + + + align:start position:0% +these +are these are all the SpaceTime bonic + + align:start position:0% +are these are all the SpaceTime bonic + + + align:start position:0% +are these are all the SpaceTime bonic +fields which are low excitations of the + + align:start position:0% +fields which are low excitations of the + + + align:start position:0% +fields which are low excitations of the +strings and they how they arise on the W + + align:start position:0% +strings and they how they arise on the W + + + align:start position:0% +strings and they how they arise on the W +sheet whether they come from fans or + + align:start position:0% +sheet whether they come from fans or + + + align:start position:0% +sheet whether they come from fans or +from bosons on the W sheet it's a + + align:start position:0% +from bosons on the W sheet it's a + + + align:start position:0% +from bosons on the W sheet it's a +separate issue yeah and uh in fact all + + align:start position:0% +separate issue yeah and uh in fact all + + + align:start position:0% +separate issue yeah and uh in fact all +of them actually arise from war she + + align:start position:0% +of them actually arise from war she + + + align:start position:0% +of them actually arise from war she +fans but their space time + + align:start position:0% +fans but their space time + + + align:start position:0% +fans but their space time +bons yes that's for the spin ority of + + align:start position:0% +bons yes that's for the spin ority of + + + align:start position:0% +bons yes that's for the spin ority of +these yeah you you just work out their + + align:start position:0% +these yeah you you just work out their + + + align:start position:0% +these yeah you you just work out their +uh their representations under the um + + align:start position:0% +uh their representations under the um + + + align:start position:0% +uh their representations under the um +under the St laen symetry okay it's + + align:start position:0% +under the St laen symetry okay it's + + + align:start position:0% +under the St laen symetry okay it's +not they're all integer spin they're all + + align:start position:0% +not they're all integer spin they're all + + + align:start position:0% +not they're all integer spin they're all +integer spin they're all integer spin + + align:start position:0% +integer spin they're all integer spin + + + align:start position:0% +integer spin they're all integer spin +reputations say of the Len group and not + + align:start position:0% +reputations say of the Len group and not + + + align:start position:0% +reputations say of the Len group and not +like fans then will be half integer + + align:start position:0% + + + + align:start position:0% + +yeah yeah they they're generating + + align:start position:0% +yeah yeah they they're generating + + + align:start position:0% +yeah yeah they they're generating +representations of the rotational group + + align:start position:0% +representations of the rotational group + + + align:start position:0% +representations of the rotational group +yeah so so so they are like a spin two + + align:start position:0% +yeah so so so they are like a spin two + + + align:start position:0% +yeah so so so they are like a spin two +SP no normally we don't call them spin + + align:start position:0% +SP no normally we don't call them spin + + + align:start position:0% +SP no normally we don't call them spin +two or spin three when when we call spin + + align:start position:0% +two or spin three when when we call spin + + + align:start position:0% +two or spin three when when we call spin +two we mean the fully symmetric indices + + align:start position:0% +two we mean the fully symmetric indices + + + align:start position:0% +two we mean the fully symmetric indices +symmetric and + + align:start position:0% +symmetric and + + + align:start position:0% +symmetric and +we never call uh uh yeah we don't call + + align:start position:0% +we never call uh uh yeah we don't call + + + align:start position:0% +we never call uh uh yeah we don't call +them spin uh yeah but yeah just the + + align:start position:0% +them spin uh yeah but yeah just the + + + align:start position:0% +them spin uh yeah but yeah just the +representation of L group it's yeah just + + align:start position:0% +representation of L group it's yeah just + + + align:start position:0% +representation of L group it's yeah just +some representations uh this integer um + + align:start position:0% +some representations uh this integer um + + + align:start position:0% +some representations uh this integer um +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +good and in the case of the + + align:start position:0% +good and in the case of the + + + align:start position:0% +good and in the case of the +Maxwell we + + align:start position:0% +Maxwell we + + + align:start position:0% +Maxwell we +know that for the one + + align:start position:0% +know that for the one + + + align:start position:0% +know that for the one +form for the for the case of the + + align:start position:0% + + + + align:start position:0% + +Maxwell it source we are familiar with + + align:start position:0% +Maxwell it source we are familiar with + + + align:start position:0% +Maxwell it source we are familiar with +this it's a source is a point + + align:start position:0% + + + + align:start position:0% + +particle okay + + align:start position:0% +particle okay + + + align:start position:0% +particle okay +so we can we can CLE + + align:start position:0% +so we can we can CLE + + + align:start position:0% +so we can we can CLE +the so the point particle interact say + + align:start position:0% +the so the point particle interact say + + + align:start position:0% +the so the point particle interact say +with this + + align:start position:0% +with this + + + align:start position:0% +with this +external EV potential in the following + + align:start position:0% + + + + align:start position:0% + +way so suppose a particle following some + + align:start position:0% +way so suppose a particle following some + + + align:start position:0% +way so suppose a particle following some +trajectory described by uh by X + + align:start position:0% +trajectory described by uh by X + + + align:start position:0% +trajectory described by uh by X +mutal and then and then this particle + + align:start position:0% +mutal and then and then this particle + + + align:start position:0% +mutal and then and then this particle +will interact with this gate uh this + + align:start position:0% +will interact with this gate uh this + + + align:start position:0% +will interact with this gate uh this +Vector potential in the following way + + align:start position:0% +Vector potential in the following way + + + align:start position:0% +Vector potential in the following way +this is familiar from E and + + align:start position:0% +this is familiar from E and + + + align:start position:0% +this is familiar from E and +M uh so you just integrate essentially + + align:start position:0% +M uh so you just integrate essentially + + + align:start position:0% +M uh so you just integrate essentially +this a along the trajectory + + align:start position:0% +this a along the trajectory + + + align:start position:0% +this a along the trajectory +uh of the particle and you can write it + + align:start position:0% +uh of the particle and you can write it + + + align:start position:0% +uh of the particle and you can write it +this in the more compact mathematical + + align:start position:0% +this in the more compact mathematical + + + align:start position:0% +this in the more compact mathematical +form you just say you integrate along + + align:start position:0% +form you just say you integrate along + + + align:start position:0% +form you just say you integrate along +the + + align:start position:0% +the + + + align:start position:0% +the +trajectory and they and a is a one form + + align:start position:0% +trajectory and they and a is a one form + + + align:start position:0% +trajectory and they and a is a one form +and you just integrate this one form + + align:start position:0% +and you just integrate this one form + + + align:start position:0% +and you just integrate this one form +along the trajectory okay and uh so this + + align:start position:0% +along the trajectory okay and uh so this + + + align:start position:0% +along the trajectory okay and uh so this +is um say it's so-call + + align:start position:0% +is um say it's so-call + + + align:start position:0% +is um say it's so-call +pullback of this one form a to c okay to + + align:start position:0% +pullback of this one form a to c okay to + + + align:start position:0% +pullback of this one form a to c okay to +see okay yeah so this is the + + align:start position:0% +see okay yeah so this is the + + + align:start position:0% +see okay yeah so this is the +mathematical language um um um yeah + + align:start position:0% +mathematical language um um um yeah + + + align:start position:0% +mathematical language um um um yeah +similarly you can generalize to this + + align:start position:0% +similarly you can generalize to this + + + align:start position:0% +similarly you can generalize to this +higher dimensional + + align:start position:0% +higher dimensional + + + align:start position:0% +higher dimensional +forms + + align:start position:0% +forms + + + align:start position:0% +forms +so so one form naturally coup to a point + + align:start position:0% +so so one form naturally coup to a point + + + align:start position:0% +so so one form naturally coup to a point +particle which can be considered as a + + align:start position:0% +particle which can be considered as a + + + align:start position:0% +particle which can be considered as a +zero dimensional + + align:start position:0% +zero dimensional + + + align:start position:0% +zero dimensional +object so a p+ one + + align:start position:0% + + + + align:start position:0% + +form p+ one form then + + align:start position:0% + + + + align:start position:0% + +naturally + + align:start position:0% +naturally + + + align:start position:0% +naturally +then yeah I should say is for then a p + + align:start position:0% +then yeah I should say is for then a p + + + align:start position:0% +then yeah I should say is for then a p +dimensional object + + align:start position:0% + + + + align:start position:0% + +the naturally compost just as a + + align:start position:0% +the naturally compost just as a + + + align:start position:0% +the naturally compost just as a +generation of + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +compose to a p+ one + + align:start position:0% + + + + align:start position:0% + +form okay as follows you can just you so + + align:start position:0% +form okay as follows you can just you so + + + align:start position:0% +form okay as follows you can just you so +the W volume of a p dimensional + + align:start position:0% +the W volume of a p dimensional + + + align:start position:0% +the W volume of a p dimensional +object is a surface of p plus one + + align:start position:0% +object is a surface of p plus one + + + align:start position:0% +object is a surface of p plus one +dimension okay so the world volume of P + + align:start position:0% +dimension okay so the world volume of P + + + align:start position:0% +dimension okay so the world volume of P +Dimension object P plus one dimension + + align:start position:0% +Dimension object P plus one dimension + + + align:start position:0% +Dimension object P plus one dimension +because there's also time you also moov + + align:start position:0% +because there's also time you also moov + + + align:start position:0% +because there's also time you also moov +in the it's a p dimensional object + + align:start position:0% +in the it's a p dimensional object + + + align:start position:0% +in the it's a p dimensional object +moving in the time then a p plus y + + align:start position:0% +moving in the time then a p plus y + + + align:start position:0% +moving in the time then a p plus y +Dimension so let me call that one volume + + align:start position:0% +Dimension so let me call that one volume + + + align:start position:0% +Dimension so let me call that one volume +Sigma and then the L generation of this + + align:start position:0% +Sigma and then the L generation of this + + + align:start position:0% +Sigma and then the L generation of this +will be + + align:start position:0% +will be + + + align:start position:0% +will be +this + + align:start position:0% +this + + + align:start position:0% +this +the cing between a two diens a p + + align:start position:0% +the cing between a two diens a p + + + align:start position:0% +the cing between a two diens a p +dimensional object to a p plus one form + + align:start position:0% +dimensional object to a p plus one form + + + align:start position:0% +dimensional object to a p plus one form +will be like this just you integrate + + align:start position:0% +will be like this just you integrate + + + align:start position:0% +will be like this just you integrate +this p+ one form on the word + + align:start position:0% +this p+ one form on the word + + + align:start position:0% +this p+ one form on the word +volume of this P dimensional object + + align:start position:0% +volume of this P dimensional object + + + align:start position:0% +volume of this P dimensional object +okay and again this is the + + align:start position:0% + + + + align:start position:0% + +pullback of C to + + align:start position:0% +pullback of C to + + + align:start position:0% +pullback of C to +Sigma + + align:start position:0% +Sigma + + + align:start position:0% +Sigma +okay C+ one to + + align:start position:0% +okay C+ one to + + + align:start position:0% +okay C+ one to +Sigma and uh and let me just write it in + + align:start position:0% +Sigma and uh and let me just write it in + + + align:start position:0% +Sigma and uh and let me just write it in +a more explicit + + align:start position:0% +a more explicit + + + align:start position:0% +a more explicit +form so here I use a tow to parameterize + + align:start position:0% +form so here I use a tow to parameterize + + + align:start position:0% +form so here I use a tow to parameterize +a trajectory along the W line so here + + align:start position:0% +a trajectory along the W line so here + + + align:start position:0% +a trajectory along the W line so here +let me + + align:start position:0% +let me + + + align:start position:0% +let me +use to parameterize the world volume + + align:start position:0% +use to parameterize the world volume + + + align:start position:0% +use to parameterize the world volume +coordinate of this brain then then this + + align:start position:0% +coordinate of this brain then then this + + + align:start position:0% +coordinate of this brain then then this +pullback + + align:start position:0% +pullback + + + align:start position:0% +pullback +means mu1 mu p + 1 + + align:start position:0% +means mu1 mu p + 1 + + + align:start position:0% +means mu1 mu p + 1 +partial X + + align:start position:0% +partial X + + + align:start position:0% +partial X +mu1 partial s + + align:start position:0% +mu1 partial s + + + align:start position:0% +mu1 partial s +One X + + align:start position:0% + + + + align:start position:0% + +mu+ and X + + align:start position:0% + + + + align:start position:0% + +mu i + + align:start position:0% +mu i + + + align:start position:0% +mu i +1ai z to + + align:start position:0% +1ai z to + + + align:start position:0% +1ai z to +p uh + + align:start position:0% +p uh + + + align:start position:0% +p uh +um describe the iding of Sigma in space + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% + + + + align:start position:0% + +okay any questions on + + align:start position:0% + + + + align:start position:0% + +this so it tells you that yeah so this + + align:start position:0% +this so it tells you that yeah so this + + + align:start position:0% +this so it tells you that yeah so this +just tells you that the uh um well there + + align:start position:0% +just tells you that the uh um well there + + + align:start position:0% +just tells you that the uh um well there +is one to P plus one but there is z to + + align:start position:0% +is one to P plus one but there is z to + + + align:start position:0% +is one to P plus one but there is z to +P good notation may we just do + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% +zero + + + align:start position:0% +zero +yes so here the the the P dimensional + + align:start position:0% +yes so here the the the P dimensional + + + align:start position:0% +yes so here the the the P dimensional +object in the simple case is just like + + align:start position:0% +object in the simple case is just like + + + align:start position:0% +object in the simple case is just like +the the point particle is a zero + + align:start position:0% +the the point particle is a zero + + + align:start position:0% +the the point particle is a zero +dimensional object so that's what the + + align:start position:0% +dimensional object so that's what the + + + align:start position:0% +dimensional object so that's what the +object is that's right that's right yeah + + align:start position:0% +object is that's right that's right yeah + + + align:start position:0% +object is that's right that's right yeah +so so yeah uh the zero dimensional + + align:start position:0% +so so yeah uh the zero dimensional + + + align:start position:0% +so so yeah uh the zero dimensional +object naturally C to one form in this + + align:start position:0% +object naturally C to one form in this + + + align:start position:0% +object naturally C to one form in this +way and then a p dimensional object + + align:start position:0% +way and then a p dimensional object + + + align:start position:0% +way and then a p dimensional object +naturally C of p plus one dimensional + + align:start position:0% +naturally C of p plus one dimensional + + + align:start position:0% +naturally C of p plus one dimensional +this way + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so let me + + align:start position:0% + + + + align:start position:0% + +just just like in the in the MK Square + + align:start position:0% +just just like in the in the MK Square + + + align:start position:0% +just just like in the in the MK Square +case the gug Symmetry + + align:start position:0% +case the gug Symmetry + + + align:start position:0% +case the gug Symmetry +here the gug Symmetry here implies that + + align:start position:0% +here the gug Symmetry here implies that + + + align:start position:0% +here the gug Symmetry here implies that +electric charge is conserved okay the + + align:start position:0% +electric charge is conserved okay the + + + align:start position:0% +electric charge is conserved okay the +electric charge is conserved so for for + + align:start position:0% +electric charge is conserved so for for + + + align:start position:0% +electric charge is conserved so for for +p dimensional + + align:start position:0% +p dimensional + + + align:start position:0% +p dimensional +object C to a p plus one dimensional + + align:start position:0% +object C to a p plus one dimensional + + + align:start position:0% +object C to a p plus one dimensional +form and because of this gaug + + align:start position:0% +form and because of this gaug + + + align:start position:0% +form and because of this gaug +Symmetry and uh and this charge is also + + align:start position:0% +Symmetry and uh and this charge is also + + + align:start position:0% +Symmetry and uh and this charge is also +conserved okay uh uh this charge is also + + align:start position:0% +conserved okay uh uh this charge is also + + + align:start position:0% +conserved okay uh uh this charge is also +conserved in particular the object with + + align:start position:0% +conserved in particular the object with + + + align:start position:0% +conserved in particular the object with +a minimal charge must be a stable object + + align:start position:0% +a minimal charge must be a stable object + + + align:start position:0% +a minimal charge must be a stable object +okay because there's nothing to Decay + + align:start position:0% +okay because there's nothing to Decay + + + align:start position:0% +okay because there's nothing to Decay +to + + align:start position:0% +to + + + align:start position:0% +to +okay okay + + align:start position:0% +okay okay + + + align:start position:0% +okay okay +so again as a + + align:start position:0% +so again as a + + + align:start position:0% +so again as a +generation of this + + align:start position:0% +generation of this + + + align:start position:0% +generation of this +case so in the standard + + align:start position:0% +case so in the standard + + + align:start position:0% +case so in the standard +story in the standard electromagnetism + + align:start position:0% +story in the standard electromagnetism + + + align:start position:0% +story in the standard electromagnetism +we can have electric charged + + align:start position:0% +we can have electric charged + + + align:start position:0% +we can have electric charged +particle we can also have a magnetic + + align:start position:0% +particle we can also have a magnetic + + + align:start position:0% +particle we can also have a magnetic +charged particle okay we can have a um + + align:start position:0% +charged particle okay we can have a um + + + align:start position:0% +charged particle okay we can have a um +magnetic charged particle um in + + align:start position:0% +magnetic charged particle um in + + + align:start position:0% +magnetic charged particle um in +particular you can + + align:start position:0% +particular you can + + + align:start position:0% +particular you can +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +um talk about the magnetic monopo in + + align:start position:0% +um talk about the magnetic monopo in + + + align:start position:0% +um talk about the magnetic monopo in +quantum mechanics and Etc even though we + + align:start position:0% +quantum mechanics and Etc even though we + + + align:start position:0% +quantum mechanics and Etc even though we +have not observed them even though we + + align:start position:0% +have not observed them even though we + + + align:start position:0% +have not observed them even though we +have not observed them so similarly one + + align:start position:0% +have not observed them so similarly one + + + align:start position:0% +have not observed them so similarly one +can generalize that concept to to higher + + align:start position:0% +can generalize that concept to to higher + + + align:start position:0% +can generalize that concept to to higher +Dimensions so let me uh first just + + align:start position:0% +Dimensions so let me uh first just + + + align:start position:0% +Dimensions so let me uh first just +remind you uh how we Define the magnetic + + align:start position:0% +remind you uh how we Define the magnetic + + + align:start position:0% +remind you uh how we Define the magnetic +so mathematical way how we Define the + + align:start position:0% +so mathematical way how we Define the + + + align:start position:0% +so mathematical way how we Define the +mathematically charged object in m so + + align:start position:0% +mathematically charged object in m so + + + align:start position:0% +mathematically charged object in m so +and + + align:start position:0% +and + + + align:start position:0% +and +M so because f is a twofold + + align:start position:0% +M so because f is a twofold + + + align:start position:0% +M so because f is a twofold +okay we can dualize f so this is H + + align:start position:0% +okay we can dualize f so this is H + + + align:start position:0% +okay we can dualize f so this is H +dual we can Define another form which I + + align:start position:0% +dual we can Define another form which I + + + align:start position:0% +dual we can Define another form which I +call F + + align:start position:0% +call F + + + align:start position:0% +call F +Thea which is related to original F by + + align:start position:0% +Thea which is related to original F by + + + align:start position:0% +Thea which is related to original F by +by H du so this is a two form the HUD of + + align:start position:0% +by H du so this is a two form the HUD of + + + align:start position:0% +by H du so this is a two form the HUD of +a two form in the four dimension is + + align:start position:0% +a two form in the four dimension is + + + align:start position:0% +a two form in the four dimension is +another two + + align:start position:0% +another two + + + align:start position:0% +another two +form and then then I can write it + + align:start position:0% +form and then then I can write it + + + align:start position:0% +form and then then I can write it +as the total derivative of the of L one + + align:start position:0% +as the total derivative of the of L one + + + align:start position:0% +as the total derivative of the of L one +form + + align:start position:0% +form + + + align:start position:0% +form +potential and then the then the + + align:start position:0% +potential and then the then the + + + align:start position:0% +potential and then the then the +object so you know that under this dual + + align:start position:0% +object so you know that under this dual + + + align:start position:0% +object so you know that under this dual +so + + align:start position:0% +so + + + align:start position:0% +so +f01 is mapped to F TAA 23 so electric + + align:start position:0% +f01 is mapped to F TAA 23 so electric + + + align:start position:0% +f01 is mapped to F TAA 23 so electric +field is mapped to magnetic field and + + align:start position:0% +field is mapped to magnetic field and + + + align:start position:0% +field is mapped to magnetic field and +similarly the magnetic field here is + + align:start position:0% +similarly the magnetic field here is + + + align:start position:0% +similarly the magnetic field here is +mapped to the electric field here okay + + align:start position:0% +mapped to the electric field here okay + + + align:start position:0% +mapped to the electric field here okay +so under this hu okay under this H yeah + + align:start position:0% +so under this hu okay under this H yeah + + + align:start position:0% +so under this hu okay under this H yeah +I should not just write just write this + + align:start position:0% +I should not just write just write this + + + align:start position:0% +I should not just write just write this +so after some Min sign we not + + align:start position:0% +so after some Min sign we not + + + align:start position:0% +so after some Min sign we not +keep track of and uh on this H + + align:start position:0% +keep track of and uh on this H + + + align:start position:0% +keep track of and uh on this H +essentially say the electric field now I + + align:start position:0% +essentially say the electric field now I + + + align:start position:0% +essentially say the electric field now I +call magnetic field okay so now + + align:start position:0% + + + + align:start position:0% + +object cou to a + + align:start position:0% + + + + align:start position:0% + +Thea then is magnetic + + align:start position:0% + + + + align:start position:0% + +charged + + align:start position:0% +charged + + + align:start position:0% +charged +okay mag that + + align:start position:0% + + + + align:start position:0% + +charged because the because of the in + + align:start position:0% +charged because the because of the in + + + align:start position:0% +charged because the because of the in +terms of a + + align:start position:0% +terms of a + + + align:start position:0% +terms of a +Thea such objects that will generate + + align:start position:0% +Thea such objects that will generate + + + align:start position:0% +Thea such objects that will generate +electric field and from the our original + + align:start position:0% +electric field and from the our original + + + align:start position:0% +electric field and from the our original +F point is a magnetic field okay so that + + align:start position:0% +F point is a magnetic field okay so that + + + align:start position:0% +F point is a magnetic field okay so that +will be a magnetically charged + + align:start position:0% +will be a magnetically charged + + + align:start position:0% +will be a magnetically charged +object so uh essentially that's how we + + align:start position:0% +object so uh essentially that's how we + + + align:start position:0% +object so uh essentially that's how we +think about the magnetic miple in and + + align:start position:0% +think about the magnetic miple in and + + + align:start position:0% +think about the magnetic miple in and +M so this can also be generalized to + + align:start position:0% +M so this can also be generalized to + + + align:start position:0% +M so this can also be generalized to +this uh uh M form case so one can also + + align:start position:0% + + + + align:start position:0% + +dualize duze + + align:start position:0% + + + + align:start position:0% + +form + + align:start position:0% +form + + + align:start position:0% +form +okay is that we introduce a lot of C + + align:start position:0% +okay is that we introduce a lot of C + + + align:start position:0% +okay is that we introduce a lot of C +Thea which is the Dual of DC so DC is + + align:start position:0% +Thea which is the Dual of DC so DC is + + + align:start position:0% +Thea which is the Dual of DC so DC is +the field strings for C so supp this is + + align:start position:0% +the field strings for C so supp this is + + + align:start position:0% +the field strings for C so supp this is +M + + align:start position:0% +M + + + align:start position:0% +M +form and uh and the D d c is a du is a + + align:start position:0% +form and uh and the D d c is a du is a + + + align:start position:0% +form and uh and the D d c is a du is a +fi strength of uh uh C and then I do a h + + align:start position:0% +fi strength of uh uh C and then I do a h + + + align:start position:0% +fi strength of uh uh C and then I do a h +dual and then uh I Define to be DCA + + align:start position:0% +dual and then uh I Define to be DCA + + + align:start position:0% +dual and then uh I Define to be DCA +okay I Define to be DCA and uh and + + align:start position:0% +okay I Define to be DCA and uh and + + + align:start position:0% +okay I Define to be DCA and uh and +DCA uh so this have M so this is M form + + align:start position:0% +DCA uh so this have M so this is M form + + + align:start position:0% +DCA uh so this have M so this is M form +when you do a field strange become M + + align:start position:0% +when you do a field strange become M + + + align:start position:0% +when you do a field strange become M +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +form and when you do the H + + align:start position:0% +form and when you do the H + + + align:start position:0% +form and when you do the H +duel take uh when you take a h duel take + + align:start position:0% + + + + align:start position:0% + +a the hot dual of M form is D minus n + + align:start position:0% +a the hot dual of M form is D minus n + + + align:start position:0% +a the hot dual of M form is D minus n +okay so so this is D minus + + align:start position:0% +okay so so this is D minus + + + align:start position:0% +okay so so this is D minus +nus + + align:start position:0% +nus + + + align:start position:0% +nus +2 okay so so this should be di should be + + align:start position:0% +2 okay so so this should be di should be + + + align:start position:0% +2 okay so so this should be di should be +a D minus nus 2 form because when you + + align:start position:0% +a D minus nus 2 form because when you + + + align:start position:0% +a D minus nus 2 form because when you +take the d then that makes into D minus + + align:start position:0% +take the d then that makes into D minus + + + align:start position:0% +take the d then that makes into D minus +nus one form and this H du take this m + + align:start position:0% +nus one form and this H du take this m + + + align:start position:0% +nus one form and this H du take this m +plus1 form into D minus n - one form + + align:start position:0% +plus1 form into D minus n - one form + + + align:start position:0% +plus1 form into D minus n - one form +okay so so you map M form to a D minus + + align:start position:0% +okay so so you map M form to a D minus + + + align:start position:0% +okay so so you map M form to a D minus +nus 2 form uh this du this so + + align:start position:0% +nus 2 form uh this du this so + + + align:start position:0% +nus 2 form uh this du this so +essentially it's the generation of the + + align:start position:0% +essentially it's the generation of the + + + align:start position:0% +essentially it's the generation of the +Electric magnetic + + align:start position:0% +Electric magnetic + + + align:start position:0% +Electric magnetic +dual of + + align:start position:0% +dual of + + + align:start position:0% +dual of +M + + align:start position:0% +M + + + align:start position:0% +M +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +now now it's now you can + + align:start position:0% + + + + align:start position:0% + +coule a D minus M minus three + + align:start position:0% +coule a D minus M minus three + + + align:start position:0% +coule a D minus M minus three +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +object + + align:start position:0% + + + + align:start position:0% + +Q + + align:start position:0% + + + + align:start position:0% + +CA okay to + + align:start position:0% + + + + align:start position:0% + +ca and in terms of + + align:start position:0% + + + + align:start position:0% + +C in terms of original C so this is a + + align:start position:0% +C in terms of original C so this is a + + + align:start position:0% +C in terms of original C so this is a +magnetic object + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +this is a magnetic object just the same + + align:start position:0% +this is a magnetic object just the same + + + align:start position:0% +this is a magnetic object just the same +as we Define magnetic mon magnetic + + align:start position:0% +as we Define magnetic mon magnetic + + + align:start position:0% +as we Define magnetic mon magnetic +object or magnetic monopole for um for + + align:start position:0% +object or magnetic monopole for um for + + + align:start position:0% +object or magnetic monopole for um for +ym so is this clear yes um in order to + + align:start position:0% +ym so is this clear yes um in order to + + + align:start position:0% +ym so is this clear yes um in order to +write F A do we have to assume that + + align:start position:0% +write F A do we have to assume that + + + align:start position:0% +write F A do we have to assume that +there are no electric charges present oh + + align:start position:0% +there are no electric charges present oh + + + align:start position:0% +there are no electric charges present oh +yeah yeah that's a good point uh um no + + align:start position:0% +yeah yeah that's a good point uh um no + + + align:start position:0% +yeah yeah that's a good point uh um no +no you don't have to um + + align:start position:0% + + + + align:start position:0% + +um so so you do this you have to assume + + align:start position:0% +um so so you do this you have to assume + + + align:start position:0% +um so so you do this you have to assume +that the equation motion is satisfied + + align:start position:0% +that the equation motion is satisfied + + + align:start position:0% +that the equation motion is satisfied +you have to assume equation motion is + + align:start position:0% +you have to assume equation motion is + + + align:start position:0% +you have to assume equation motion is +satisfied then you can write this + + align:start position:0% +satisfied then you can write this + + + align:start position:0% +satisfied then you can write this +procedure + + align:start position:0% +procedure + + + align:start position:0% +procedure +yeah so but if if DF is equal to J and + + align:start position:0% +yeah so but if if DF is equal to J and + + + align:start position:0% +yeah so but if if DF is equal to J and +that is non zero so there are yeah uh so + + align:start position:0% +that is non zero so there are yeah uh so + + + align:start position:0% +that is non zero so there are yeah uh so +you have exactly the similar situation + + align:start position:0% +you have exactly the similar situation + + + align:start position:0% +you have exactly the similar situation +with and M just identical situation with + + align:start position:0% +with and M just identical situation with + + + align:start position:0% +with and M just identical situation with +and M just whatever you do in the e m + + align:start position:0% +and M just whatever you do in the e m + + + align:start position:0% +and M just whatever you do in the e m +you do it here + + align:start position:0% +you do it here + + + align:start position:0% +you do it here +so I I thought that we could only write + + align:start position:0% +so I I thought that we could only write + + + align:start position:0% +so I I thought that we could only write +FAL to + + align:start position:0% +FAL to + + + align:start position:0% +FAL to +Da because there were no + + align:start position:0% +Da because there were no + + + align:start position:0% +Da because there were no +magnetic uh no so so you can do that now + + align:start position:0% +magnetic uh no so so you can do that now + + + align:start position:0% +magnetic uh no so so you can do that now +you have to introduce some + + align:start position:0% +you have to introduce some + + + align:start position:0% +you have to introduce some +similarity so that's why the magnetic + + align:start position:0% +similarity so that's why the magnetic + + + align:start position:0% +similarity so that's why the magnetic +mon have a direct string uh that's why + + align:start position:0% +mon have a direct string uh that's why + + + align:start position:0% +mon have a direct string uh that's why +the magnetic mon have direct string then + + align:start position:0% +the magnetic mon have direct string then + + + align:start position:0% +the magnetic mon have direct string then +you have this direct quation condition + + align:start position:0% +you have this direct quation condition + + + align:start position:0% +you have this direct quation condition +ET say you would then say either in and + + align:start position:0% +ET say you would then say either in and + + + align:start position:0% +ET say you would then say either in and +M or in the in the uh in the quantum + + align:start position:0% +M or in the in the uh in the quantum + + + align:start position:0% +M or in the in the uh in the quantum +mechanics say in the gra quantum + + align:start position:0% +mechanics say in the gra quantum + + + align:start position:0% +mechanics say in the gra quantum +mechanics or or + + align:start position:0% + + + + align:start position:0% + +orm um so are people familiar with the + + align:start position:0% +orm um so are people familiar with the + + + align:start position:0% +orm um so are people familiar with the +concept of magnetic monopo and d soal d + + align:start position:0% +concept of magnetic monopo and d soal d + + + align:start position:0% +concept of magnetic monopo and d soal d +string and D quantization + + align:start position:0% +string and D quantization + + + align:start position:0% +string and D quantization +condition yeah I saw some loading head + + align:start position:0% +condition yeah I saw some loading head + + + align:start position:0% +condition yeah I saw some loading head +yeah yeah so uh so you're not familiar + + align:start position:0% +yeah yeah so uh so you're not familiar + + + align:start position:0% +yeah yeah so uh so you're not familiar +with it and look at for for example uh + + align:start position:0% +with it and look at for for example uh + + + align:start position:0% +with it and look at for for example uh +uh in in one chapter of Jackson uh have + + align:start position:0% +uh in in one chapter of Jackson uh have + + + align:start position:0% +uh in in one chapter of Jackson uh have +a very uh detailed discussion of + + align:start position:0% +a very uh detailed discussion of + + + align:start position:0% +a very uh detailed discussion of +magnetic monopoles and uh um but the + + align:start position:0% +magnetic monopoles and uh um but the + + + align:start position:0% +magnetic monopoles and uh um but the +best actually was the original paper uh + + align:start position:0% +best actually was the original paper uh + + + align:start position:0% +best actually was the original paper uh +it was really beautiful very very + + align:start position:0% +it was really beautiful very very + + + align:start position:0% +it was really beautiful very very +beautiful uh yeah but Jackson has a + + align:start position:0% +beautiful uh yeah but Jackson has a + + + align:start position:0% +beautiful uh yeah but Jackson has a +rather pedagogic discussion yeah + + align:start position:0% +rather pedagogic discussion yeah + + + align:start position:0% +rather pedagogic discussion yeah +Jackson's in actual in actual Dynamics + + align:start position:0% +Jackson's in actual in actual Dynamics + + + align:start position:0% +Jackson's in actual in actual Dynamics +has rather yeah we do see discussion + + align:start position:0% +has rather yeah we do see discussion + + + align:start position:0% +has rather yeah we do see discussion +differential form though or I don't + + align:start position:0% +differential form though or I don't + + + align:start position:0% +differential form though or I don't +remember you mean Jackson yeah I don't + + align:start position:0% +remember you mean Jackson yeah I don't + + + align:start position:0% +remember you mean Jackson yeah I don't +remember + + align:start position:0% +remember + + + align:start position:0% +remember +yeah yeah it's the fact that you you can + + align:start position:0% +yeah yeah it's the fact that you you can + + + align:start position:0% +yeah yeah it's the fact that you you can +allow the magnetic monopo uh uh then if + + align:start position:0% +allow the magnetic monopo uh uh then if + + + align:start position:0% +allow the magnetic monopo uh uh then if +you allow the certain singularities in + + align:start position:0% +you allow the certain singularities in + + + align:start position:0% +you allow the certain singularities in +the vector potential and so that's soal + + align:start position:0% + + + + align:start position:0% + +derx yeah so you don't have to introduce + + align:start position:0% +derx yeah so you don't have to introduce + + + align:start position:0% +derx yeah so you don't have to introduce +yeah so the idea is that + + align:start position:0% +yeah so the idea is that + + + align:start position:0% +yeah so the idea is that +you what you were saying is right the + + align:start position:0% +you what you were saying is right the + + + align:start position:0% +you what you were saying is right the +fact that you can write f as a da means + + align:start position:0% +fact that you can write f as a da means + + + align:start position:0% +fact that you can write f as a da means +there's no magnetic Source but you can + + align:start position:0% +there's no magnetic Source but you can + + + align:start position:0% +there's no magnetic Source but you can +introduce a magnetic Source if you allow + + align:start position:0% +introduce a magnetic Source if you allow + + + align:start position:0% +introduce a magnetic Source if you allow +certain similarities and uh and that's + + align:start position:0% +certain similarities and uh and that's + + + align:start position:0% +certain similarities and uh and that's +what the uh uh uh what rock + + align:start position:0% +what the uh uh uh what rock + + + align:start position:0% +what the uh uh uh what rock +realized + + align:start position:0% +realized + + + align:start position:0% +realized +yeah good + + align:start position:0% +yeah good + + + align:start position:0% +yeah good +so now these are St this are the gauge + + align:start position:0% +so now these are St this are the gauge + + + align:start position:0% +so now these are St this are the gauge +fields in type 2 a and type 2 b string + + align:start position:0% +fields in type 2 a and type 2 b string + + + align:start position:0% +fields in type 2 a and type 2 b string +and then then they can give rise to um + + align:start position:0% +and then then they can give rise to um + + + align:start position:0% +and then then they can give rise to um +to Extended object which CER to them and + + align:start position:0% +to Extended object which CER to them and + + + align:start position:0% +to Extended object which CER to them and +turn out the the extended object cover + + align:start position:0% +turn out the the extended object cover + + + align:start position:0% +turn out the the extended object cover +to those remone remon fields are + + align:start position:0% +to those remone remon fields are + + + align:start position:0% +to those remone remon fields are +precisely + + align:start position:0% +precisely + + + align:start position:0% +precisely +deep a precisely de brains and uh and + + align:start position:0% +deep a precisely de brains and uh and + + + align:start position:0% +deep a precisely de brains and uh and +the precisely de brains and because the + + align:start position:0% +the precisely de brains and because the + + + align:start position:0% +the precisely de brains and because the +couple to those gauge fields and they + + align:start position:0% +couple to those gauge fields and they + + + align:start position:0% +couple to those gauge fields and they +they are a stable object at least the + + align:start position:0% +they are a stable object at least the + + + align:start position:0% +they are a stable object at least the +minimal charge ones are stable object + + align:start position:0% +minimal charge ones are stable object + + + align:start position:0% +minimal charge ones are stable object +okay and so this is related to the + + align:start position:0% +okay and so this is related to the + + + align:start position:0% +okay and so this is related to the +statement that actually in super string + + align:start position:0% +statement that actually in super string + + + align:start position:0% +statement that actually in super string +you actually find some stable brains and + + align:start position:0% +you actually find some stable brains and + + + align:start position:0% +you actually find some stable brains and +for other di yeah so let me just list + + align:start position:0% +for other di yeah so let me just list + + + align:start position:0% +for other di yeah so let me just list +them just + + align:start position:0% + + + + align:start position:0% + +to so so with this + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +preparation the then in 2 + + align:start position:0% + + + + align:start position:0% + +a so we can have the + + align:start position:0% +a so we can have the + + + align:start position:0% +a so we can have the +following electric and F magnetic + + align:start position:0% +following electric and F magnetic + + + align:start position:0% +following electric and F magnetic +object so in the 2A we have a c mu1 we + + align:start position:0% +object so in the 2A we have a c mu1 we + + + align:start position:0% +object so in the 2A we have a c mu1 we +have a one + + align:start position:0% +have a one + + + align:start position:0% +have a one +form so that means this + + align:start position:0% +form so that means this + + + align:start position:0% +form so that means this +natural object C to + + align:start position:0% +natural object C to + + + align:start position:0% +natural object C to +it electric object C out this is a dzero + + align:start position:0% +it electric object C out this is a dzero + + + align:start position:0% +it electric object C out this is a dzero +brain okay a zero Di object C to one + + align:start position:0% +brain okay a zero Di object C to one + + + align:start position:0% +brain okay a zero Di object C to one +form this is the zero + + align:start position:0% +form this is the zero + + + align:start position:0% +form this is the zero +brain and a one form in 10 + + align:start position:0% +brain and a one form in 10 + + + align:start position:0% +brain and a one form in 10 +Dimension so in super Str we have 10 + + align:start position:0% +Dimension so in super Str we have 10 + + + align:start position:0% +Dimension so in super Str we have 10 +Dimension is dual to uh so D is 10 minus + + align:start position:0% +Dimension is dual to uh so D is 10 minus + + + align:start position:0% +Dimension is dual to uh so D is 10 minus +1 is 9 - 3 is + + align:start position:0% +1 is 9 - 3 is + + + align:start position:0% +1 is 9 - 3 is + + align:start position:0% + + + align:start position:0% +no uh yeah yeah yeah yeah it's six and + + align:start position:0% +no uh yeah yeah yeah yeah it's six and + + + align:start position:0% +no uh yeah yeah yeah yeah it's six and +then the magnetic object will be a D6 + + align:start position:0% +then the magnetic object will be a D6 + + + align:start position:0% +then the magnetic object will be a D6 +spring + + align:start position:0% +spring + + + align:start position:0% +spring +okay so similarly we have a three + + align:start position:0% + + + + align:start position:0% + +form and then this give electric D2 + + align:start position:0% +form and then this give electric D2 + + + align:start position:0% +form and then this give electric D2 +brain and the Magnetic def4 + + align:start position:0% +brain and the Magnetic def4 + + + align:start position:0% +brain and the Magnetic def4 +brain okay magnetic def4 brain so if you + + align:start position:0% +brain okay magnetic def4 brain so if you + + + align:start position:0% +brain okay magnetic def4 brain so if you +just follow this + + align:start position:0% +just follow this + + + align:start position:0% +just follow this +rule so for the type + + align:start position:0% + + + + align:start position:0% + +QB for the type to B so so let me not uh + + align:start position:0% +QB for the type to B so so let me not uh + + + align:start position:0% +QB for the type to B so so let me not uh +uh first start with this + + align:start position:0% +uh first start with this + + + align:start position:0% +uh first start with this +C2 so this give you a this string one + + align:start position:0% +C2 so this give you a this string one + + + align:start position:0% +C2 so this give you a this string one +dimensional object coupl to it for the + + align:start position:0% +dimensional object coupl to it for the + + + align:start position:0% +dimensional object coupl to it for the +this + + align:start position:0% +this + + + align:start position:0% +this +string and then then the then the + + align:start position:0% +string and then then the then the + + + align:start position:0% +string and then then the then the +magnetic object will be a five + + align:start position:0% +magnetic object will be a five + + + align:start position:0% +magnetic object will be a five +dimensional object it's called the D5 + + align:start position:0% +dimensional object it's called the D5 + + + align:start position:0% +dimensional object it's called the D5 +brain so this string is a D1 + + align:start position:0% +brain so this string is a D1 + + + align:start position:0% +brain so this string is a D1 +brain so now let's look at this four + + align:start position:0% + + + + align:start position:0% + +form this four form so so called self + + align:start position:0% +form this four form so so called self + + + align:start position:0% +form this four form so so called self +duel so sometimes we put a plus here to + + align:start position:0% +duel so sometimes we put a plus here to + + + align:start position:0% +duel so sometimes we put a plus here to +indicate this is a self duel so let me + + align:start position:0% +indicate this is a self duel so let me + + + align:start position:0% +indicate this is a self duel so let me +now explain what what this say self dual + + align:start position:0% +now explain what what this say self dual + + + align:start position:0% +now explain what what this say self dual +means so self + + align:start position:0% +means so self + + + align:start position:0% +means so self +dual means that from C4 I can construct + + align:start position:0% +dual means that from C4 I can construct + + + align:start position:0% +dual means that from C4 I can construct +the + + align:start position:0% + + + + align:start position:0% + +F5 and construct F5 from this D + + align:start position:0% +F5 and construct F5 from this D + + + align:start position:0% +F5 and construct F5 from this D +C4 okay to be a self dual form means + + align:start position:0% +C4 okay to be a self dual form means + + + align:start position:0% +C4 okay to be a self dual form means +that this form satisfy the condition + + align:start position:0% +that this form satisfy the condition + + + align:start position:0% +that this form satisfy the condition +that F5 equal to F5 + + align:start position:0% +that F5 equal to F5 + + + align:start position:0% +that F5 equal to F5 +duel this is a self duel just means just + + align:start position:0% +duel this is a self duel just means just + + + align:start position:0% +duel this is a self duel just means just +this is a constraint that this C has to + + align:start position:0% +this is a constraint that this C has to + + + align:start position:0% +this is a constraint that this C has to +satisfy so this is called the selfdual + + align:start position:0% +satisfy so this is called the selfdual + + + align:start position:0% +satisfy so this is called the selfdual +for form + + align:start position:0% +for form + + + align:start position:0% +for form +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh that just form + + align:start position:0% +uh that just form + + + align:start position:0% +uh that just form +the yeah if you look at the + + align:start position:0% +the yeah if you look at the + + + align:start position:0% +the yeah if you look at the +representations of the r IM you find + + align:start position:0% +representations of the r IM you find + + + align:start position:0% +representations of the r IM you find +this is actually a representation and so + + align:start position:0% +this is actually a representation and so + + + align:start position:0% +this is actually a representation and so +so for for this C you have to satisfy + + align:start position:0% +so for for this C you have to satisfy + + + align:start position:0% +so for for this C you have to satisfy +the S of Duality + + align:start position:0% +the S of Duality + + + align:start position:0% +the S of Duality +condition then now for object which C to + + align:start position:0% +condition then now for object which C to + + + align:start position:0% +condition then now for object which C to +the + + align:start position:0% +the + + + align:start position:0% +the +C will be a a l D3 brain because the + + align:start position:0% +C will be a a l D3 brain because the + + + align:start position:0% +C will be a a l D3 brain because the +three form uh three dimension object C + + align:start position:0% +three form uh three dimension object C + + + align:start position:0% +three form uh three dimension object C +to four form so will be a D3 + + align:start position:0% +to four form so will be a D3 + + + align:start position:0% +to four form so will be a D3 +brain and this this re brain because of + + align:start position:0% +brain and this this re brain because of + + + align:start position:0% +brain and this this re brain because of +this self Duality + + align:start position:0% +this self Duality + + + align:start position:0% +this self Duality +condition we have to be both electric + + align:start position:0% +condition we have to be both electric + + + align:start position:0% +condition we have to be both electric +and magnetically charged + + align:start position:0% +and magnetically charged + + + align:start position:0% +and magnetically charged +okay okay because the uh um yeah because + + align:start position:0% +okay okay because the uh um yeah because + + + align:start position:0% +okay okay because the uh um yeah because +this is the self dual form + + align:start position:0% +this is the self dual form + + + align:start position:0% +this is the self dual form +okay uh uh + + align:start position:0% + + + + align:start position:0% + +so so the so this must Source both + + align:start position:0% +so so the so this must Source both + + + align:start position:0% +so so the so this must Source both +electric flux and magnetic flux to be + + align:start position:0% +electric flux and magnetic flux to be + + + align:start position:0% +electric flux and magnetic flux to be +consistent with s of + + align:start position:0% +consistent with s of + + + align:start position:0% +consistent with s of +Duality + + align:start position:0% + + + + align:start position:0% + +okay and and + + align:start position:0% +okay and and + + + align:start position:0% +okay and and +finally you can also have a scaler + + align:start position:0% +finally you can also have a scaler + + + align:start position:0% +finally you can also have a scaler +field in the type Tob and the Scala + + align:start position:0% +field in the type Tob and the Scala + + + align:start position:0% +field in the type Tob and the Scala +field naively you will couple to soall D + + align:start position:0% +field naively you will couple to soall D + + + align:start position:0% +field naively you will couple to soall D +minus one dimensional brain because + + align:start position:0% +minus one dimensional brain because + + + align:start position:0% +minus one dimensional brain because +Scala field by itself is zero dimension + + align:start position:0% +Scala field by itself is zero dimension + + + align:start position:0% +Scala field by itself is zero dimension +okay it's already Zero Dimensional form + + align:start position:0% +okay it's already Zero Dimensional form + + + align:start position:0% +okay it's already Zero Dimensional form +so so so so follow this convention Will + + align:start position:0% +so so so so follow this convention Will + + + align:start position:0% +so so so so follow this convention Will +C to D minus one dimensional brain and + + align:start position:0% +C to D minus one dimensional brain and + + + align:start position:0% +C to D minus one dimensional brain and +uh and that obviously does not make much + + align:start position:0% +uh and that obviously does not make much + + + align:start position:0% +uh and that obviously does not make much +sense and but but actually can be made + + align:start position:0% +sense and but but actually can be made + + + align:start position:0% +sense and but but actually can be made +sense when you go to cing signature and + + align:start position:0% +sense when you go to cing signature and + + + align:start position:0% +sense when you go to cing signature and +then uh this um this scalar field cou to + + align:start position:0% +then uh this um this scalar field cou to + + + align:start position:0% +then uh this um this scalar field cou to +something called instanton which I we + + align:start position:0% +something called instanton which I we + + + align:start position:0% +something called instanton which I we +not going to there something called D Sy + + align:start position:0% +not going to there something called D Sy + + + align:start position:0% +not going to there something called D Sy +okay so so the bottom + + align:start position:0% +okay so so the bottom + + + align:start position:0% +okay so so the bottom +line is said + + align:start position:0% +line is said + + + align:start position:0% +line is said +the the object we are charged on those R + + align:start position:0% +the the object we are charged on those R + + + align:start position:0% +the the object we are charged on those R +Roman field they all deep brains they + + align:start position:0% +Roman field they all deep brains they + + + align:start position:0% +Roman field they all deep brains they +all deep brains and then they come into + + align:start position:0% +all deep brains and then they come into + + + align:start position:0% +all deep brains and then they come into +those + + align:start position:0% +those + + + align:start position:0% +those +dimensions and any deep bra of course + + align:start position:0% +dimensions and any deep bra of course + + + align:start position:0% +dimensions and any deep bra of course +you can define deep brain with other + + align:start position:0% +you can define deep brain with other + + + align:start position:0% +you can define deep brain with other +dimensions so you can consider in a a + + align:start position:0% +dimensions so you can consider in a a + + + align:start position:0% +dimensions so you can consider in a a +this three brain but the in a a this3 + + align:start position:0% +this three brain but the in a a this3 + + + align:start position:0% +this three brain but the in a a this3 +brain will not be a stable object + + align:start position:0% +brain will not be a stable object + + + align:start position:0% +brain will not be a stable object +because there's no conserved charge for + + align:start position:0% +because there's no conserved charge for + + + align:start position:0% +because there's no conserved charge for +carer two so so even though uh Ina you + + align:start position:0% +carer two so so even though uh Ina you + + + align:start position:0% +carer two so so even though uh Ina you +can can see the this rein but it's not a + + align:start position:0% +can can see the this rein but it's not a + + + align:start position:0% +can can see the this rein but it's not a +stable object and actually uh when you + + align:start position:0% +stable object and actually uh when you + + + align:start position:0% +stable object and actually uh when you +Contex the Spectrum on the this rebrin + + align:start position:0% +Contex the Spectrum on the this rebrin + + + align:start position:0% +Contex the Spectrum on the this rebrin +into a then you find there a tan again + + align:start position:0% +into a then you find there a tan again + + + align:start position:0% +into a then you find there a tan again +there's a tang in the world volume + + align:start position:0% +there's a tang in the world volume + + + align:start position:0% +there's a tang in the world volume +indicate that's not stable object and + + align:start position:0% +indicate that's not stable object and + + + align:start position:0% +indicate that's not stable object and +but those brains uh don't have TS + + align:start position:0% +but those brains uh don't have TS + + + align:start position:0% +but those brains uh don't have TS +okay and in particular on those brains + + align:start position:0% +okay and in particular on those brains + + + align:start position:0% +okay and in particular on those brains +this all super symmetric field + + align:start position:0% +this all super symmetric field + + + align:start position:0% +this all super symmetric field +series for example uh the the most + + align:start position:0% +series for example uh the the most + + + align:start position:0% +series for example uh the the most +important one is this this rebrin + + align:start position:0% +important one is this this rebrin + + + align:start position:0% +important one is this this rebrin +because then then you have four + + align:start position:0% +because then then you have four + + + align:start position:0% +because then then you have four +dimensional W volume then you actually + + align:start position:0% +dimensional W volume then you actually + + + align:start position:0% +dimensional W volume then you actually +have a four dimensional Ser on this this + + align:start position:0% +have a four dimensional Ser on this this + + + align:start position:0% +have a four dimensional Ser on this this +rebrin and uh and that's what I give you + + align:start position:0% +rebrin and uh and that's what I give you + + + align:start position:0% +rebrin and uh and that's what I give you +So-Cal inqu for Super Y Ser okay so on + + align:start position:0% +So-Cal inqu for Super Y Ser okay so on + + + align:start position:0% +So-Cal inqu for Super Y Ser okay so on +this + + align:start position:0% +this + + + align:start position:0% +this +brains on these stable + + align:start position:0% +brains on these stable + + + align:start position:0% +brains on these stable +brains the energy + + align:start position:0% +brains the energy + + + align:start position:0% +brains the energy +theories are super smat super yam + + align:start position:0% + + + + align:start position:0% + +ser + + align:start position:0% +ser + + + align:start position:0% +ser +in particular for for + + align:start position:0% +in particular for for + + + align:start position:0% +in particular for for +D3 it given by soal in4 Super Y + + align:start position:0% +D3 it given by soal in4 Super Y + + + align:start position:0% +D3 it given by soal in4 Super Y +Ser in in four dimension + + align:start position:0% + + + + align:start position:0% + +okay four + + align:start position:0% + + + + align:start position:0% + +dimensions yeah it can Decay it can + + align:start position:0% +dimensions yeah it can Decay it can + + + align:start position:0% +dimensions yeah it can Decay it can +Decay into lower dimensional brand it + + align:start position:0% +Decay into lower dimensional brand it + + + align:start position:0% +Decay into lower dimensional brand it +can it actually um it's possible for you + + align:start position:0% +can it actually um it's possible for you + + + align:start position:0% +can it actually um it's possible for you +to Decay into lower dimensional brain it + + align:start position:0% +to Decay into lower dimensional brain it + + + align:start position:0% +to Decay into lower dimensional brain it +can also for it just to Decay into close + + align:start position:0% +can also for it just to Decay into close + + + align:start position:0% +can also for it just to Decay into close +stream modes radiate Clos stre mod yeah + + align:start position:0% +stream modes radiate Clos stre mod yeah + + + align:start position:0% +stream modes radiate Clos stre mod yeah +okay I mean the dimension of these two + + align:start position:0% +okay I mean the dimension of these two + + + align:start position:0% +okay I mean the dimension of these two +object are different it sounds like you + + align:start position:0% +object are different it sounds like you + + + align:start position:0% +object are different it sounds like you +have if your brains to decate Str you + + align:start position:0% +have if your brains to decate Str you + + + align:start position:0% +have if your brains to decate Str you +will become INF yeah that's right you + + align:start position:0% +will become INF yeah that's right you + + + align:start position:0% +will become INF yeah that's right you +did have a density of + + align:start position:0% +did have a density of + + + align:start position:0% +did have a density of +strings + + align:start position:0% +strings + + + align:start position:0% +strings +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um yeah it's actually a beautiful + + align:start position:0% +um yeah it's actually a beautiful + + + align:start position:0% +um yeah it's actually a beautiful +subject to to discuss those brains how + + align:start position:0% +subject to to discuss those brains how + + + align:start position:0% +subject to to discuss those brains how +they + + align:start position:0% +they + + + align:start position:0% +they +Decay um yeah yeah one can actually + + align:start position:0% +Decay um yeah yeah one can actually + + + align:start position:0% +Decay um yeah yeah one can actually +do um yeah it's a it's a it's a it's a + + align:start position:0% +do um yeah it's a it's a it's a it's a + + + align:start position:0% +do um yeah it's a it's a it's a it's a +nice subject yeah but it's way out of + + align:start position:0% +nice subject yeah but it's way out of + + + align:start position:0% +nice subject yeah but it's way out of +our discussion + + align:start position:0% + + + + align:start position:0% + +here any questions yes as before if we + + align:start position:0% +here any questions yes as before if we + + + align:start position:0% +here any questions yes as before if we +consider stacks of such brains do we get + + align:start position:0% +consider stacks of such brains do we get + + + align:start position:0% +consider stacks of such brains do we get +higher rank AG groups yeah that's right + + align:start position:0% +higher rank AG groups yeah that's right + + + align:start position:0% +higher rank AG groups yeah that's right +exactly it's always give you un + + align:start position:0% +exactly it's always give you un + + + align:start position:0% +exactly it's always give you un +yeah + + align:start position:0% + + + + align:start position:0% + +good so that conclude our + + align:start position:0% + + + + align:start position:0% + +discussion of the deep + + align:start position:0% + + + + align:start position:0% + +brains in from the point of view as + + align:start position:0% +brains in from the point of view as + + + align:start position:0% +brains in from the point of view as +dally boundary conditions + + align:start position:0% + + + + align:start position:0% + +okay as a the rich boundary + + align:start position:0% +okay as a the rich boundary + + + align:start position:0% +okay as a the rich boundary +conditions so now I want to take a + + align:start position:0% +conditions so now I want to take a + + + align:start position:0% +conditions so now I want to take a +slightly different perspective on the + + align:start position:0% +slightly different perspective on the + + + align:start position:0% +slightly different perspective on the +Deep + + align:start position:0% +Deep + + + align:start position:0% +Deep +brains + + align:start position:0% +brains + + + align:start position:0% +brains +from this + + align:start position:0% + + + + align:start position:0% + +perspective from there from the + + align:start position:0% +perspective from there from the + + + align:start position:0% +perspective from there from the +perspective there object which are + + align:start position:0% +perspective there object which are + + + align:start position:0% +perspective there object which are +charged under those generalized Gate + + align:start position:0% +charged under those generalized Gate + + + align:start position:0% +charged under those generalized Gate +Fields okay uh and now I want to view + + align:start position:0% +Fields okay uh and now I want to view + + + align:start position:0% +Fields okay uh and now I want to view +those difference as some object some sol + + align:start position:0% +those difference as some object some sol + + + align:start position:0% +those difference as some object some sol +T if you if you want some sol T which + + align:start position:0% +T if you if you want some sol T which + + + align:start position:0% +T if you if you want some sol T which +are charged under those generalized gaug + + align:start position:0% +are charged under those generalized gaug + + + align:start position:0% +are charged under those generalized gaug +Fields okay I want to take I want to + + align:start position:0% +Fields okay I want to take I want to + + + align:start position:0% +Fields okay I want to take I want to +elaborate from this perspective okay + + align:start position:0% + + + + align:start position:0% + +now I talk about the + + align:start position:0% +now I talk about the + + + align:start position:0% +now I talk about the +different + + align:start position:0% + + + + align:start position:0% + +perspective + + align:start position:0% + + + + align:start position:0% + +okay so deep brain has a + + align:start position:0% +okay so deep brain has a + + + align:start position:0% +okay so deep brain has a +mass has a tension also deep BR carry so + + align:start position:0% +mass has a tension also deep BR carry so + + + align:start position:0% +mass has a tension also deep BR carry so +now we only consider the stable deep + + align:start position:0% +now we only consider the stable deep + + + align:start position:0% +now we only consider the stable deep +Brands so they have a mass they also + + align:start position:0% +Brands so they have a mass they also + + + align:start position:0% +Brands so they have a mass they also +carry those charges conserved charges so + + align:start position:0% +carry those charges conserved charges so + + + align:start position:0% +carry those charges conserved charges so +that means there will be flux coming out + + align:start position:0% +that means there will be flux coming out + + + align:start position:0% +that means there will be flux coming out +electric or magnetic flux coming out of + + align:start position:0% +electric or magnetic flux coming out of + + + align:start position:0% +electric or magnetic flux coming out of +those + + align:start position:0% + + + + align:start position:0% + +brains so that will deform the space + + align:start position:0% +brains so that will deform the space + + + align:start position:0% +brains so that will deform the space +time + + align:start position:0% +time + + + align:start position:0% +time +okay uh um yeah because the the + + align:start position:0% +okay uh um yeah because the the + + + align:start position:0% +okay uh um yeah because the the +gravitate will deform space + + align:start position:0% + + + + align:start position:0% + +time and so now we would like to find + + align:start position:0% +time and so now we would like to find + + + align:start position:0% +time and so now we would like to find +out what are the space time around those + + align:start position:0% +out what are the space time around those + + + align:start position:0% +out what are the space time around those +uh de brains okay how do they deform + + align:start position:0% +uh de brains okay how do they deform + + + align:start position:0% +uh de brains okay how do they deform +space time so to + + align:start position:0% +space time so to + + + align:start position:0% +space time so to +example say it's consider say consider + + align:start position:0% +example say it's consider say consider + + + align:start position:0% +example say it's consider say consider +charge as a to example of this say let's + + align:start position:0% +charge as a to example of this say let's + + + align:start position:0% +charge as a to example of this say let's +consider just again in the Maxwell + + align:start position:0% +consider just again in the Maxwell + + + align:start position:0% +consider just again in the Maxwell +theory in Einstein Max wheell Theory + + align:start position:0% +theory in Einstein Max wheell Theory + + + align:start position:0% +theory in Einstein Max wheell Theory +consider for example a Charged + + align:start position:0% + + + + align:start position:0% + +particle + + align:start position:0% +particle + + + align:start position:0% +particle +sitting say at the + + align:start position:0% + + + + align:start position:0% + +origin say of four dimensional space + + align:start position:0% + + + + align:start position:0% + +time say cute space time for + + align:start position:0% + + + + align:start position:0% + +example so if you include both gr and M + + align:start position:0% +example so if you include both gr and M + + + align:start position:0% +example so if you include both gr and M +then the Dynamics of this series + + align:start position:0% +then the Dynamics of this series + + + align:start position:0% +then the Dynamics of this series +controlled by soall Einstein Max well so + + align:start position:0% +controlled by soall Einstein Max well so + + + align:start position:0% +controlled by soall Einstein Max well so +so you will have a Einstein + + align:start position:0% + + + + align:start position:0% + +theory and the max will + + align:start position:0% + + + + align:start position:0% + +okay so dynamics of such particles + + align:start position:0% +okay so dynamics of such particles + + + align:start position:0% +okay so dynamics of such particles +should cap should be captured by them + + align:start position:0% +should cap should be captured by them + + + align:start position:0% +should cap should be captured by them +and so this C so this capture the + + align:start position:0% +and so this C so this capture the + + + align:start position:0% +and so this C so this capture the +gravity due to the particle this + + align:start position:0% +gravity due to the particle this + + + align:start position:0% +gravity due to the particle this +captures the y m due to the + + align:start position:0% + + + + align:start position:0% + +particle so from here you can work out + + align:start position:0% +particle so from here you can work out + + + align:start position:0% +particle so from here you can work out +how does this particle say a deform + + align:start position:0% +how does this particle say a deform + + + align:start position:0% +how does this particle say a deform +space time okay from the Einstein + + align:start position:0% +space time okay from the Einstein + + + align:start position:0% +space time okay from the Einstein +equation so so the equation motion of + + align:start position:0% +equation so so the equation motion of + + + align:start position:0% +equation so so the equation motion of +this system would be + + align:start position:0% +this system would be + + + align:start position:0% +this system would be +you have a a standard max + + align:start position:0% + + + + align:start position:0% + +well so I not be careful about the minus + + align:start position:0% +well so I not be careful about the minus + + + align:start position:0% +well so I not be careful about the minus +sign uh and the also the Einstein + + align:start position:0% + + + + align:start position:0% + +equation the stress + + align:start position:0% + + + + align:start position:0% + +sensor okay so so the J so J is just the + + align:start position:0% +sensor okay so so the J so J is just the + + + align:start position:0% +sensor okay so so the J so J is just the +J is just the the + + align:start position:0% + + + + align:start position:0% + +um say if I have a charge particle + + align:start position:0% +um say if I have a charge particle + + + align:start position:0% +um say if I have a charge particle +sitting there there's no current there's + + align:start position:0% +sitting there there's no current there's + + + align:start position:0% +sitting there there's no current there's +only a charge + + align:start position:0% +only a charge + + + align:start position:0% +only a charge +density + + align:start position:0% +density + + + align:start position:0% +density +okay and the stress + + align:start position:0% +okay and the stress + + + align:start position:0% +okay and the stress +tensor containing two + + align:start position:0% +tensor containing two + + + align:start position:0% +tensor containing two +parts is the stress tens due to the + + align:start position:0% + + + + align:start position:0% + +particle and also the stress due to the + + align:start position:0% +particle and also the stress due to the + + + align:start position:0% +particle and also the stress due to the +electromagnetic + + align:start position:0% +electromagnetic + + + align:start position:0% +electromagnetic +field okay okay because this exciting + + align:start position:0% +field okay okay because this exciting + + + align:start position:0% +field okay okay because this exciting +that to magnetic + + align:start position:0% +that to magnetic + + + align:start position:0% +that to magnetic +field and uh and the and the particle + + align:start position:0% +field and uh and the and the particle + + + align:start position:0% +field and uh and the and the particle +part only have a zero zero component so + + align:start position:0% +part only have a zero zero component so + + + align:start position:0% +part only have a zero zero component so +you only have a mass there's no momentum + + align:start position:0% +you only have a mass there's no momentum + + + align:start position:0% +you only have a mass there's no momentum +so this is just a say maybe I should + + align:start position:0% +so this is just a say maybe I should + + + align:start position:0% +so this is just a say maybe I should +write + + align:start position:0% +write + + + align:start position:0% +write +R yeah I think I'm using notation of R + + align:start position:0% +R yeah I think I'm using notation of R + + + align:start position:0% +R yeah I think I'm using notation of R +okay so the so the uh um the particle + + align:start position:0% +okay so the so the uh um the particle + + + align:start position:0% +okay so the so the uh um the particle +part of the Str tensor would be just the + + align:start position:0% +part of the Str tensor would be just the + + + align:start position:0% +part of the Str tensor would be just the +data function uh uh uh the only non zero + + align:start position:0% +data function uh uh uh the only non zero + + + align:start position:0% +data function uh uh uh the only non zero +component are Z zero component you only + + align:start position:0% +component are Z zero component you only + + + align:start position:0% +component are Z zero component you only +have energy density and it's just given + + align:start position:0% +have energy density and it's just given + + + align:start position:0% +have energy density and it's just given +by the by the data function of the + + align:start position:0% +by the by the data function of the + + + align:start position:0% +by the by the data function of the +mass so so so from + + align:start position:0% +mass so so so from + + + align:start position:0% +mass so so so from +here by solving those equations with + + align:start position:0% +here by solving those equations with + + + align:start position:0% +here by solving those equations with +those sources then you can work out how + + align:start position:0% +those sources then you can work out how + + + align:start position:0% +those sources then you can work out how +a Charged particle deform your space + + align:start position:0% +a Charged particle deform your space + + + align:start position:0% +a Charged particle deform your space +time okay how charge particle deform + + align:start position:0% +time okay how charge particle deform + + + align:start position:0% +time okay how charge particle deform +your space + + align:start position:0% +your space + + + align:start position:0% +your space +time + + align:start position:0% + + + + align:start position:0% + +so so let me just say a little bit + + align:start position:0% +so so let me just say a little bit + + + align:start position:0% +so so let me just say a little bit +further for example you can easily solve + + align:start position:0% +further for example you can easily solve + + + align:start position:0% +further for example you can easily solve +the an equation we allow the + + align:start position:0% +the an equation we allow the + + + align:start position:0% +the an equation we allow the +Solutions so you just have a coolum + + align:start position:0% +Solutions so you just have a coolum + + + align:start position:0% +Solutions so you just have a coolum +potential you just have a + + align:start position:0% +potential you just have a + + + align:start position:0% +potential you just have a +potential and uh and and the other words + + align:start position:0% +potential and uh and and the other words + + + align:start position:0% +potential and uh and and the other words +you have in other words you have + + align:start position:0% +you have in other words you have + + + align:start position:0% +you have in other words you have +electric + + align:start position:0% +electric + + + align:start position:0% +electric +flux surrounding the S2 around the point + + align:start position:0% + + + + align:start position:0% + +particle equal to Q + + align:start position:0% +particle equal to Q + + + align:start position:0% +particle equal to Q +okay again this is the Dual of f uh you + + align:start position:0% +okay again this is the Dual of f uh you + + + align:start position:0% +okay again this is the Dual of f uh you +have electric field when you dual + + align:start position:0% +have electric field when you dual + + + align:start position:0% +have electric field when you dual +dualize then then have special component + + align:start position:0% +dualize then then have special component + + + align:start position:0% +dualize then then have special component +then that give you this yeah so this is + + align:start position:0% +then that give you this yeah so this is + + + align:start position:0% +then that give you this yeah so this is +a g La + + align:start position:0% +a g La + + + align:start position:0% +a g La +okay this is G + + align:start position:0% + + + + align:start position:0% + +LA and you can also work + + align:start position:0% +LA and you can also work + + + align:start position:0% +LA and you can also work +out uh the matric surrounding this + + align:start position:0% +out uh the matric surrounding this + + + align:start position:0% +out uh the matric surrounding this +charge particles so because the space + + align:start position:0% +charge particles so because the space + + + align:start position:0% +charge particles so because the space +time is symmetric spical symmetric then + + align:start position:0% +time is symmetric spical symmetric then + + + align:start position:0% +time is symmetric spical symmetric then +you can actually write down a spical + + align:start position:0% +you can actually write down a spical + + + align:start position:0% +you can actually write down a spical +symmetric an for the metric around the + + align:start position:0% +symmetric an for the metric around the + + + align:start position:0% +symmetric an for the metric around the +particle + + align:start position:0% + + + + align:start position:0% + +so from the + + align:start position:0% + + + + align:start position:0% + +equation you can find out what you can + + align:start position:0% +equation you can find out what you can + + + align:start position:0% +equation you can find out what you can +work out what is fr and HR okay so some + + align:start position:0% +work out what is fr and HR okay so some + + + align:start position:0% +work out what is fr and HR okay so some +of you may have already done this + + align:start position:0% +of you may have already done this + + + align:start position:0% +of you may have already done this +exercise + + align:start position:0% +exercise + + + align:start position:0% +exercise +before so if your Q is zero what answer + + align:start position:0% +before so if your Q is zero what answer + + + align:start position:0% +before so if your Q is zero what answer +would you + + align:start position:0% +would you + + + align:start position:0% +would you +get that's right + + align:start position:0% +get that's right + + + align:start position:0% +get that's right +so if the um Q is zero then you just get + + align:start position:0% +so if the um Q is zero then you just get + + + align:start position:0% +so if the um Q is zero then you just get +a swash matric and it's exactly the + + align:start position:0% +a swash matric and it's exactly the + + + align:start position:0% +a swash matric and it's exactly the +metric as say produced by a s Etc far + + align:start position:0% +metric as say produced by a s Etc far + + + align:start position:0% +metric as say produced by a s Etc far +away okay and uh um so so here we have a + + align:start position:0% +away okay and uh um so so here we have a + + + align:start position:0% +away okay and uh um so so here we have a +charge then what you get is something + + align:start position:0% +charge then what you get is something + + + align:start position:0% +charge then what you get is something +called the Ral nostrom matric and uh uh + + align:start position:0% +called the Ral nostrom matric and uh uh + + + align:start position:0% +called the Ral nostrom matric and uh uh +uh when you have a charge have + + align:start position:0% +uh when you have a charge have + + + align:start position:0% +uh when you have a charge have +electromagnetic + + align:start position:0% +electromagnetic + + + align:start position:0% +electromagnetic +field okay so so you will + + align:start position:0% +field okay so so you will + + + align:start position:0% +field okay so so you will +get so called + + align:start position:0% + + + + align:start position:0% + +Ral + + align:start position:0% + + + + align:start position:0% + +no okay that's Q z h if Q equal Z no no + + align:start position:0% +no okay that's Q z h if Q equal Z no no + + + align:start position:0% +no okay that's Q z h if Q equal Z no no +no that's the Q to Z is nostrum and when + + align:start position:0% +no that's the Q to Z is nostrum and when + + + align:start position:0% +no that's the Q to Z is nostrum and when +Q equal to zero then you just get the + + align:start position:0% +Q equal to zero then you just get the + + + align:start position:0% +Q equal to zero then you just get the +swashi um yeah that's that's how you + + align:start position:0% +swashi um yeah that's that's how you + + + align:start position:0% +swashi um yeah that's that's how you +calculate the uh precession yeah that's + + align:start position:0% +calculate the uh precession yeah that's + + + align:start position:0% +calculate the uh precession yeah that's +what you use to calculate the precession + + align:start position:0% +what you use to calculate the precession + + + align:start position:0% +what you use to calculate the precession +of say of the + + align:start position:0% + + + + align:start position:0% + +Mercury similarly you can also do this + + align:start position:0% +Mercury similarly you can also do this + + + align:start position:0% +Mercury similarly you can also do this +for for magnetic charge particle so the + + align:start position:0% +for for magnetic charge particle so the + + + align:start position:0% +for for magnetic charge particle so the +only + + align:start position:0% +only + + + align:start position:0% +only +difference for magnetic charge + + align:start position:0% + + + + align:start position:0% + +particle + + align:start position:0% + + + + align:start position:0% + +the difference is that this + + align:start position:0% +the difference is that this + + + align:start position:0% +the difference is that this +equation now + + align:start position:0% +equation now + + + align:start position:0% +equation now +become just directly magnetic flux equal + + align:start position:0% +become just directly magnetic flux equal + + + align:start position:0% +become just directly magnetic flux equal +to G say for example if it's a uh say if + + align:start position:0% +to G say for example if it's a uh say if + + + align:start position:0% +to G say for example if it's a uh say if +the magnetic charge is + + align:start position:0% +the magnetic charge is + + + align:start position:0% +the magnetic charge is +G of charge + + align:start position:0% + + + + align:start position:0% + +G and then you will get this then then + + align:start position:0% +G and then you will get this then then + + + align:start position:0% +G and then you will get this then then +you that you have this and then and then + + align:start position:0% +you that you have this and then and then + + + align:start position:0% +you that you have this and then and then +you have um yeah you have magnetic flux + + align:start position:0% +you have um yeah you have magnetic flux + + + align:start position:0% +you have um yeah you have magnetic flux +and again you can plug into Einstein + + align:start position:0% +and again you can plug into Einstein + + + align:start position:0% +and again you can plug into Einstein +equation you solve you get the same rum + + align:start position:0% +equation you solve you get the same rum + + + align:start position:0% +equation you solve you get the same rum +matric so also a direct + + align:start position:0% + + + + align:start position:0% + +quantization tell you that the + + align:start position:0% + + + + align:start position:0% + +qg should be quantized in integers of 2 + + align:start position:0% +qg should be quantized in integers of 2 + + + align:start position:0% +qg should be quantized in integers of 2 +pi n Nal to 1 2 Etc + + align:start position:0% + + + + align:start position:0% + +okay so this is the familiar story in + + align:start position:0% +okay so this is the familiar story in + + + align:start position:0% +okay so this is the familiar story in +the gr so if you want to look at how uh + + align:start position:0% +the gr so if you want to look at how uh + + + align:start position:0% +the gr so if you want to look at how uh +how the gravity and uh and the and them + + align:start position:0% +how the gravity and uh and the and them + + + align:start position:0% +how the gravity and uh and the and them +surrounding a charged + + align:start position:0% +surrounding a charged + + + align:start position:0% +surrounding a charged +object and so you can generalize this + + align:start position:0% +object and so you can generalize this + + + align:start position:0% +object and so you can generalize this +story immediately to those + + align:start position:0% +story immediately to those + + + align:start position:0% +story immediately to those +brains which are charg which they have + + align:start position:0% +brains which are charg which they have + + + align:start position:0% +brains which are charg which they have +their own mass and charged under some + + align:start position:0% +their own mass and charged under some + + + align:start position:0% +their own mass and charged under some +some generalized gaug Fields okay so you + + align:start position:0% +some generalized gaug Fields okay so you + + + align:start position:0% +some generalized gaug Fields okay so you +can generalize that + + align:start position:0% +can generalize that + + + align:start position:0% +can generalize that +immediately so you can generalize + + align:start position:0% +immediately so you can generalize + + + align:start position:0% +immediately so you can generalize +procedure immediately to higher + + align:start position:0% +procedure immediately to higher + + + align:start position:0% +procedure immediately to higher +Dimension + + align:start position:0% + + + + align:start position:0% + +object so uh so you can + + align:start position:0% +object so uh so you can + + + align:start position:0% +object so uh so you can +just as a simple exercise in + + align:start position:0% +just as a simple exercise in + + + align:start position:0% +just as a simple exercise in +gr you can just carry out this + + align:start position:0% +gr you can just carry out this + + + align:start position:0% +gr you can just carry out this +procedure just replace this to some + + align:start position:0% +procedure just replace this to some + + + align:start position:0% +procedure just replace this to some +higher dimensional + + align:start position:0% +higher dimensional + + + align:start position:0% +higher dimensional +form and the and the source is some + + align:start position:0% +form and the and the source is some + + + align:start position:0% +form and the and the source is some +higher dimensional object then you can + + align:start position:0% +higher dimensional object then you can + + + align:start position:0% +higher dimensional object then you can +work out the solutions + + align:start position:0% +work out the solutions + + + align:start position:0% +work out the solutions +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um and that was a simple + + align:start position:0% +um and that was a simple + + + align:start position:0% +um and that was a simple +exercise which actually hor and storing + + align:start position:0% +exercise which actually hor and storing + + + align:start position:0% +exercise which actually hor and storing +did in early 90s in + + align:start position:0% +did in early 90s in + + + align:start position:0% +did in early 90s in +1991 yeah it's a triv generalization you + + align:start position:0% +1991 yeah it's a triv generalization you + + + align:start position:0% +1991 yeah it's a triv generalization you +can do while not do it but turns out to + + align:start position:0% +can do while not do it but turns out to + + + align:start position:0% +can do while not do it but turns out to +be a tend out that's a very very + + align:start position:0% +be a tend out that's a very very + + + align:start position:0% +be a tend out that's a very very +important step to do uh for the reason U + + align:start position:0% +important step to do uh for the reason U + + + align:start position:0% +important step to do uh for the reason U +uh which I will + + align:start position:0% +uh which I will + + + align:start position:0% +uh which I will +explain so for Simplicity let me just + + align:start position:0% +explain so for Simplicity let me just + + + align:start position:0% +explain so for Simplicity let me just +talk a little bit about doing this for + + align:start position:0% +talk a little bit about doing this for + + + align:start position:0% +talk a little bit about doing this for +this rebrin also for definitely you can + + align:start position:0% +this rebrin also for definitely you can + + + align:start position:0% +this rebrin also for definitely you can +do it for any of these and the name me + + align:start position:0% +do it for any of these and the name me + + + align:start position:0% +do it for any of these and the name me +just say for to to this re + + align:start position:0% +just say for to to this re + + + align:start position:0% +just say for to to this re +brain so now + + align:start position:0% +brain so now + + + align:start position:0% +brain so now +consider say this three + + align:start position:0% +consider say this three + + + align:start position:0% +consider say this three +brain so this re brain is part of the + + align:start position:0% +brain so this re brain is part of the + + + align:start position:0% +brain so this re brain is part of the +type 2B + + align:start position:0% + + + + align:start position:0% + +Theory so of course we don't know how + + align:start position:0% +Theory so of course we don't know how + + + align:start position:0% +Theory so of course we don't know how +really do this in the full type Tob + + align:start position:0% +really do this in the full type Tob + + + align:start position:0% +really do this in the full type Tob +string so we will do the Lowery limit + + align:start position:0% +string so we will do the Lowery limit + + + align:start position:0% +string so we will do the Lowery limit +type Tob string so we do this for the + + align:start position:0% +type Tob string so we do this for the + + + align:start position:0% +type Tob string so we do this for the +this R brain in the lower limit of type + + align:start position:0% +this R brain in the lower limit of type + + + align:start position:0% +this R brain in the lower limit of type +Tob + + align:start position:0% +Tob + + + align:start position:0% +Tob +string which is soal type Tob super + + align:start position:0% +string which is soal type Tob super + + + align:start position:0% +string which is soal type Tob super +gravity okay so so it doesn't matter you + + align:start position:0% +gravity okay so so it doesn't matter you + + + align:start position:0% +gravity okay so so it doesn't matter you +don't know anything about type to be + + align:start position:0% +don't know anything about type to be + + + align:start position:0% +don't know anything about type to be +super gravity and essentially + + align:start position:0% +super gravity and essentially + + + align:start position:0% +super gravity and essentially +that's just some generation of this + + align:start position:0% +that's just some generation of this + + + align:start position:0% +that's just some generation of this +equation okay type to B graphity just + + align:start position:0% +equation okay type to B graphity just + + + align:start position:0% +equation okay type to B graphity just +some generation of this + + align:start position:0% +some generation of this + + + align:start position:0% +some generation of this +equation but the 11 is let me just + + align:start position:0% +equation but the 11 is let me just + + + align:start position:0% +equation but the 11 is let me just +introduce some notations just to be uh + + align:start position:0% +introduce some notations just to be uh + + + align:start position:0% +introduce some notations just to be uh +uh to be + + align:start position:0% +uh to be + + + align:start position:0% +uh to be +um so type to be super + + align:start position:0% + + + + align:start position:0% + +gravity we will do this in the in the in + + align:start position:0% +gravity we will do this in the in the in + + + align:start position:0% +gravity we will do this in the in the in +the low energy limit of the two to be + + align:start position:0% +the low energy limit of the two to be + + + align:start position:0% +the low energy limit of the two to be +string so this is the low energy + + align:start position:0% +string so this is the low energy + + + align:start position:0% +string so this is the low energy +effctive Theory + + align:start position:0% + + + + align:start position:0% + +for M this + + align:start position:0% + + + + align:start position:0% + +modes of to be string + + align:start position:0% + + + + align:start position:0% + +okay so it has the form as the what we + + align:start position:0% +okay so it has the form as the what we + + + align:start position:0% +okay so it has the form as the what we +have before + + align:start position:0% +have before + + + align:start position:0% +have before +we have 1 / 6 Pi T Pi GN but now this is + + align:start position:0% +we have 1 / 6 Pi T Pi GN but now this is + + + align:start position:0% +we have 1 / 6 Pi T Pi GN but now this is +a 10 dimensional Newton constant so this + + align:start position:0% +a 10 dimensional Newton constant so this + + + align:start position:0% +a 10 dimensional Newton constant so this +is a 10 dimensional + + align:start position:0% +is a 10 dimensional + + + align:start position:0% +is a 10 dimensional +Ser equal to + + align:start position:0% +Ser equal to + + + align:start position:0% +Ser equal to +10 and uh and you have a yeah you have + + align:start position:0% +10 and uh and you have a yeah you have + + + align:start position:0% +10 and uh and you have a yeah you have +the Einstein term and then you have + + align:start position:0% +the Einstein term and then you have + + + align:start position:0% +the Einstein term and then you have +forms associated with all this flock uh + + align:start position:0% +forms associated with all this flock uh + + + align:start position:0% +forms associated with all this flock uh +uh uh generalized gaug field etc for + + align:start position:0% +uh uh generalized gaug field etc for + + + align:start position:0% +uh uh generalized gaug field etc for +ETC okay and as we said + + align:start position:0% +ETC okay and as we said + + + align:start position:0% +ETC okay and as we said +before the relation with String Theory + + align:start position:0% +before the relation with String Theory + + + align:start position:0% +before the relation with String Theory +the Newton + + align:start position:0% +the Newton + + + align:start position:0% +the Newton +constant should be proportional to GS + + align:start position:0% +constant should be proportional to GS + + + align:start position:0% +constant should be proportional to GS +squ okay so you can actually work the + + align:start position:0% +squ okay so you can actually work the + + + align:start position:0% +squ okay so you can actually work the +work out the prefactor precisely so let + + align:start position:0% +work out the prefactor precisely so let + + + align:start position:0% +work out the prefactor precisely so let +me just write down the preactor so the + + align:start position:0% +me just write down the preactor so the + + + align:start position:0% +me just write down the preactor so the +relation with the string is yeah just on + + align:start position:0% +relation with the string is yeah just on + + + align:start position:0% +relation with the string is yeah just on +dimensional ground so this is the Newton + + align:start position:0% +dimensional ground so this is the Newton + + + align:start position:0% +dimensional ground so this is the Newton +constant in 10 Dimension so this would + + align:start position:0% +constant in 10 Dimension so this would + + + align:start position:0% +constant in 10 Dimension so this would +have Dimension + + align:start position:0% +have Dimension + + + align:start position:0% +have Dimension +eight in terms of the length have a + + align:start position:0% +eight in terms of the length have a + + + align:start position:0% +eight in terms of the length have a +dimension eight so the right hand side + + align:start position:0% +dimension eight so the right hand side + + + align:start position:0% +dimension eight so the right hand side +must be Alpha Prime to the power four + + align:start position:0% +must be Alpha Prime to the power four + + + align:start position:0% +must be Alpha Prime to the power four +because this is only L scale in Str + + align:start position:0% +because this is only L scale in Str + + + align:start position:0% +because this is only L scale in Str +the and then the prefactor turn out to + + align:start position:0% +the and then the prefactor turn out to + + + align:start position:0% +the and then the prefactor turn out to +be so you can work out the prefactor so + + align:start position:0% +be so you can work out the prefactor so + + + align:start position:0% +be so you can work out the prefactor so +turn out 16 Pi GN is equal to 2 pi 2 + + align:start position:0% +turn out 16 Pi GN is equal to 2 pi 2 + + + align:start position:0% +turn out 16 Pi GN is equal to 2 pi 2 +the^ + + align:start position:0% +the^ + + + align:start position:0% +the^ + + align:start position:0% + + + + align:start position:0% + +okay uh uh uh say when you work out the + + align:start position:0% +okay uh uh uh say when you work out the + + + align:start position:0% +okay uh uh uh say when you work out the +Lo Factor Ser you can work out this pre + + align:start position:0% +Lo Factor Ser you can work out this pre + + + align:start position:0% +Lo Factor Ser you can work out this pre +precise + + align:start position:0% +precise + + + align:start position:0% +precise +factor and the regime of the validity of + + align:start position:0% +factor and the regime of the validity of + + + align:start position:0% +factor and the regime of the validity of +this type to be super + + align:start position:0% + + + + align:start position:0% + +gravity is that the GS is much much + + align:start position:0% +gravity is that the GS is much much + + + align:start position:0% +gravity is that the GS is much much +smaller than one string com should be + + align:start position:0% +smaller than one string com should be + + + align:start position:0% +smaller than one string com should be +much much smaller than + + align:start position:0% +much much smaller than + + + align:start position:0% +much much smaller than +one so that just tell this is a + + align:start position:0% +one so that just tell this is a + + + align:start position:0% +one so that just tell this is a +statement that the string Loop + + align:start position:0% +statement that the string Loop + + + align:start position:0% +statement that the string Loop +correction should be small because when + + align:start position:0% +correction should be small because when + + + align:start position:0% +correction should be small because when +the G stram become big the loop + + align:start position:0% +the G stram become big the loop + + + align:start position:0% +the G stram become big the loop +correction become more more and more + + align:start position:0% +correction become more more and more + + + align:start position:0% +correction become more more and more +important uh uh um + + align:start position:0% + + + + align:start position:0% + +the loop correction will be more + + align:start position:0% +the loop correction will be more + + + align:start position:0% +the loop correction will be more +important from the point of view of + + align:start position:0% +important from the point of view of + + + align:start position:0% +important from the point of view of +gravity uh these are quantum + + align:start position:0% +gravity uh these are quantum + + + align:start position:0% +gravity uh these are quantum +gravitational Corrections and so so when + + align:start position:0% +gravitational Corrections and so so when + + + align:start position:0% +gravitational Corrections and so so when +G stram become bigger the quantum + + align:start position:0% +G stram become bigger the quantum + + + align:start position:0% +G stram become bigger the quantum +gravitational Corrections so the space + + align:start position:0% +gravitational Corrections so the space + + + align:start position:0% +gravitational Corrections so the space +time we fluctuate more and then of + + align:start position:0% +time we fluctuate more and then of + + + align:start position:0% +time we fluctuate more and then of +course you cannot trust the classical + + align:start position:0% +course you cannot trust the classical + + + align:start position:0% +course you cannot trust the classical +gravity in that regime so if you want to + + align:start position:0% +gravity in that regime so if you want to + + + align:start position:0% +gravity in that regime so if you want to +trust the classical gravity you want to + + align:start position:0% +trust the classical gravity you want to + + + align:start position:0% +trust the classical gravity you want to +have small cing or translate into this + + align:start position:0% +have small cing or translate into this + + + align:start position:0% +have small cing or translate into this +language as a newon con have to be small + + align:start position:0% +language as a newon con have to be small + + + align:start position:0% +language as a newon con have to be small +okay the Newton constant have to be + + align:start position:0% +okay the Newton constant have to be + + + align:start position:0% +okay the Newton constant have to be +small that means the gravity is weak + + align:start position:0% +small that means the gravity is weak + + + align:start position:0% +small that means the gravity is weak +okay that means gravity is weak but in + + align:start position:0% +okay that means gravity is weak but in + + + align:start position:0% +okay that means gravity is weak but in +real life gravity is weak so it's + + align:start position:0% +real life gravity is weak so it's + + + align:start position:0% +real life gravity is weak so it's +okay and uh so this means the quantum + + align:start position:0% +okay and uh so this means the quantum + + + align:start position:0% +okay and uh so this means the quantum +correction is + + align:start position:0% + + + + align:start position:0% + +small so you can trust classical + + align:start position:0% + + + + align:start position:0% + +gravity okay so you can TR a classical + + align:start position:0% +gravity okay so you can TR a classical + + + align:start position:0% +gravity okay so you can TR a classical +gravity and we also want the uh the + + align:start position:0% +gravity and we also want the uh the + + + align:start position:0% +gravity and we also want the uh the +energy no energy so we want the energy + + align:start position:0% +energy no energy so we want the energy + + + align:start position:0% +energy no energy so we want the energy +Square to be smaller than one over Alpha + + align:start position:0% +Square to be smaller than one over Alpha + + + align:start position:0% +Square to be smaller than one over Alpha +Prime because when when the energy + + align:start position:0% +Prime because when when the energy + + + align:start position:0% +Prime because when when the energy +Square become with all the One alha + + align:start position:0% +Square become with all the One alha + + + align:start position:0% +Square become with all the One alha +Prime then the massive stream modes + + align:start position:0% +Prime then the massive stream modes + + + align:start position:0% +Prime then the massive stream modes +become important because all the massive + + align:start position:0% +become important because all the massive + + + align:start position:0% +become important because all the massive +stream mode have mass square of one of + + align:start position:0% +stream mode have mass square of one of + + + align:start position:0% +stream mode have mass square of one of +AL Prime and if we only want to + + align:start position:0% +AL Prime and if we only want to + + + align:start position:0% +AL Prime and if we only want to +concentrate on the massless modes and + + align:start position:0% +concentrate on the massless modes and + + + align:start position:0% +concentrate on the massless modes and +you don't want to excite them + + align:start position:0% + + + + align:start position:0% + +okay and also you want the curvature of + + align:start position:0% +okay and also you want the curvature of + + + align:start position:0% +okay and also you want the curvature of +the space time here we consider in curve + + align:start position:0% +the space time here we consider in curve + + + align:start position:0% +the space time here we consider in curve +space + + align:start position:0% +space + + + align:start position:0% +space +time so you want want the curvature to + + align:start position:0% +time so you want want the curvature to + + + align:start position:0% +time so you want want the curvature to +be much smaller than one of alpha + + align:start position:0% +be much smaller than one of alpha + + + align:start position:0% +be much smaller than one of alpha +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +okay so um so this gravity essentially + + align:start position:0% +okay so um so this gravity essentially + + + align:start position:0% +okay so um so this gravity essentially +when you consider the mass this particle + + align:start position:0% +when you consider the mass this particle + + + align:start position:0% +when you consider the mass this particle +you consider the particle limit of the + + align:start position:0% +you consider the particle limit of the + + + align:start position:0% +you consider the particle limit of the +space time so so this can be considered + + align:start position:0% +space time so so this can be considered + + + align:start position:0% +space time so so this can be considered +say as that you consider the space time + + align:start position:0% +say as that you consider the space time + + + align:start position:0% +say as that you consider the space time +curv the space time curvature radius is + + align:start position:0% +curv the space time curvature radius is + + + align:start position:0% +curv the space time curvature radius is +much much so so Alpha primeti this gives + + align:start position:0% +much much so so Alpha primeti this gives + + + align:start position:0% +much much so so Alpha primeti this gives +the rough lens scale of a + + align:start position:0% +the rough lens scale of a + + + align:start position:0% +the rough lens scale of a +string and when the curvature is much + + align:start position:0% +string and when the curvature is much + + + align:start position:0% +string and when the curvature is much +much smaller one prime that means that + + align:start position:0% +much smaller one prime that means that + + + align:start position:0% +much smaller one prime that means that +the side of the string is + + align:start position:0% +the side of the string is + + + align:start position:0% +the side of the string is +Tiny compare to the curvature radius + + align:start position:0% +Tiny compare to the curvature radius + + + align:start position:0% +Tiny compare to the curvature radius +okay the typical Sid of your system and + + align:start position:0% +okay the typical Sid of your system and + + + align:start position:0% +okay the typical Sid of your system and +that's you can roughly treat them as a + + align:start position:0% +that's you can roughly treat them as a + + + align:start position:0% +that's you can roughly treat them as a +point + + align:start position:0% +point + + + align:start position:0% +point +particles and that's what the gravity + + align:start position:0% +particles and that's what the gravity + + + align:start position:0% +particles and that's what the gravity +Theory does yeah in the super gravity + + align:start position:0% +Theory does yeah in the super gravity + + + align:start position:0% +Theory does yeah in the super gravity +Theory it's all Point particles + + align:start position:0% +Theory it's all Point particles + + + align:start position:0% +Theory it's all Point particles +okay and uh and so this means we + + align:start position:0% +okay and uh and so this means we + + + align:start position:0% +okay and uh and so this means we +toule massive + + align:start position:0% + + + + align:start position:0% + +modes okay massive + + align:start position:0% +modes okay massive + + + align:start position:0% +modes okay massive +modes so you can concentrate on mass + + align:start position:0% +modes so you can concentrate on mass + + + align:start position:0% +modes so you can concentrate on mass +this + + align:start position:0% + + + + align:start position:0% + +modes + + align:start position:0% +modes + + + align:start position:0% +modes +so whenever you take a limit you always + + align:start position:0% +so whenever you take a limit you always + + + align:start position:0% +so whenever you take a limit you always +have to take the dimension is numers + + align:start position:0% +have to take the dimension is numers + + + align:start position:0% +have to take the dimension is numers +more so the dimension is number is Alpha + + align:start position:0% +more so the dimension is number is Alpha + + + align:start position:0% +more so the dimension is number is Alpha +Prime Times curvature Al time times + + align:start position:0% +Prime Times curvature Al time times + + + align:start position:0% +Prime Times curvature Al time times +energy square but in reality we often + + align:start position:0% +energy square but in reality we often + + + align:start position:0% +energy square but in reality we often +when we work with the series we often + + align:start position:0% +when we work with the series we often + + + align:start position:0% +when we work with the series we often +just keep our curvature or our energy + + align:start position:0% +just keep our curvature or our energy + + + align:start position:0% +just keep our curvature or our energy +scale as what we want and then in + + align:start position:0% +scale as what we want and then in + + + align:start position:0% +scale as what we want and then in +talking about this limit we just say we + + align:start position:0% +talking about this limit we just say we + + + align:start position:0% +talking about this limit we just say we +take Alpa Prime goes to zero limit okay + + align:start position:0% +take Alpa Prime goes to zero limit okay + + + align:start position:0% +take Alpa Prime goes to zero limit okay +we say we take Alpa Prime goes to zero + + align:start position:0% +we say we take Alpa Prime goes to zero + + + align:start position:0% +we say we take Alpa Prime goes to zero +limit so that means a low energy limit + + align:start position:0% +limit so that means a low energy limit + + + align:start position:0% +limit so that means a low energy limit +okay even though uh uh legitimately this + + align:start position:0% +okay even though uh uh legitimately this + + + align:start position:0% +okay even though uh uh legitimately this +is not the right thing to say because + + align:start position:0% +is not the right thing to say because + + + align:start position:0% +is not the right thing to say because +this is dimensional + + align:start position:0% +this is dimensional + + + align:start position:0% +this is dimensional +parameter and so so the regime which + + align:start position:0% +parameter and so so the regime which + + + align:start position:0% +parameter and so so the regime which +super gravity Works can be form at say + + align:start position:0% +super gravity Works can be form at say + + + align:start position:0% +super gravity Works can be form at say +as Alpha Prime go to zero and the g + + align:start position:0% +as Alpha Prime go to zero and the g + + + align:start position:0% +as Alpha Prime go to zero and the g +string go to zero + + align:start position:0% + + + + align:start position:0% + +okay so so in this regime now you can + + align:start position:0% +okay so so in this regime now you can + + + align:start position:0% +okay so so in this regime now you can +work with super gravity and now you can + + align:start position:0% +work with super gravity and now you can + + + align:start position:0% +work with super gravity and now you can +now + + align:start position:0% +now + + + align:start position:0% +now +generalize this story to the brains okay + + align:start position:0% +generalize this story to the brains okay + + + align:start position:0% +generalize this story to the brains okay +now gener this story for brains so now + + align:start position:0% +now gener this story for brains so now + + + align:start position:0% +now gener this story for brains so now +let me say a few things about the D + + align:start position:0% +let me say a few things about the D + + + align:start position:0% +let me say a few things about the D +brain d three + + align:start position:0% + + + + align:start position:0% + +brain + + align:start position:0% + + + + align:start position:0% + +so de bra this rebr + + align:start position:0% + + + + align:start position:0% + +charged + + align:start position:0% +charged + + + align:start position:0% +charged +under C4 Plus + + align:start position:0% +under C4 Plus + + + align:start position:0% +under C4 Plus +this C4 + + align:start position:0% +this C4 + + + align:start position:0% +this C4 +plus and we said this C4 plus is + + align:start position:0% +plus and we said this C4 plus is + + + align:start position:0% +plus and we said this C4 plus is +required to be + + align:start position:0% +required to be + + + align:start position:0% +required to be +selfdual that means any source of C4 + + align:start position:0% +selfdual that means any source of C4 + + + align:start position:0% +selfdual that means any source of C4 +plus must carry both electric and + + align:start position:0% +plus must carry both electric and + + + align:start position:0% +plus must carry both electric and +magnetic charge so that + + align:start position:0% +magnetic charge so that + + + align:start position:0% +magnetic charge so that +means that for the this re + + align:start position:0% +means that for the this re + + + align:start position:0% +means that for the this re +brain say if you define an electric + + align:start position:0% +brain say if you define an electric + + + align:start position:0% +brain say if you define an electric +charge to + + align:start position:0% +charge to + + + align:start position:0% +charge to +be so now so the this three brain is a + + align:start position:0% +be so now so the this three brain is a + + + align:start position:0% +be so now so the this three brain is a +threedimensional + + align:start position:0% + + + + align:start position:0% + +object and the transverse direction is a + + align:start position:0% +object and the transverse direction is a + + + align:start position:0% +object and the transverse direction is a +six dimensional okay because this is + + align:start position:0% +six dimensional okay because this is + + + align:start position:0% +six dimensional okay because this is +three plus one including time so the + + align:start position:0% +three plus one including time so the + + + align:start position:0% +three plus one including time so the +transverse direction is is six + + align:start position:0% +transverse direction is is six + + + align:start position:0% +transverse direction is is six +dimensional so we can simply just think + + align:start position:0% +dimensional so we can simply just think + + + align:start position:0% +dimensional so we can simply just think +about the this Rin so if we if we ignore + + align:start position:0% +about the this Rin so if we if we ignore + + + align:start position:0% +about the this Rin so if we if we ignore +the spal direction along the + + align:start position:0% +the spal direction along the + + + align:start position:0% +the spal direction along the +brain then then this re brain the + + align:start position:0% +brain then then this re brain the + + + align:start position:0% +brain then then this re brain the +transverse Direction then can be just + + align:start position:0% +transverse Direction then can be just + + + align:start position:0% +transverse Direction then can be just +consider a point in R six okay okay so + + align:start position:0% +consider a point in R six okay okay so + + + align:start position:0% +consider a point in R six okay okay so +so way to think about the this rant the + + align:start position:0% +so way to think about the this rant the + + + align:start position:0% +so way to think about the this rant the +surrounding the dis rant just it's + + align:start position:0% +surrounding the dis rant just it's + + + align:start position:0% +surrounding the dis rant just it's +analog of a point in R6 in the six + + align:start position:0% +analog of a point in R6 in the six + + + align:start position:0% +analog of a point in R6 in the six +dimensional space this this + + align:start position:0% +dimensional space this this + + + align:start position:0% +dimensional space this this +clear this is going to be very important + + align:start position:0% +clear this is going to be very important + + + align:start position:0% +clear this is going to be very important +and then the surrounding this + + align:start position:0% +and then the surrounding this + + + align:start position:0% +and then the surrounding this +point the sphere will be + + align:start position:0% +point the sphere will be + + + align:start position:0% +point the sphere will be +S5 okay just like in the electric case + + align:start position:0% +S5 okay just like in the electric case + + + align:start position:0% +S5 okay just like in the electric case +just in the like and M case this is the + + align:start position:0% +just in the like and M case this is the + + + align:start position:0% +just in the like and M case this is the +S2 surrounding the point particle and + + align:start position:0% +S2 surrounding the point particle and + + + align:start position:0% +S2 surrounding the point particle and +this S5 is the sphere which surrounding + + align:start position:0% +this S5 is the sphere which surrounding + + + align:start position:0% +this S5 is the sphere which surrounding +the whole this rein and and then this D + + align:start position:0% +the whole this rein and and then this D + + + align:start position:0% +the whole this rein and and then this D +can have electric and magnetic flux + + align:start position:0% +can have electric and magnetic flux + + + align:start position:0% +can have electric and magnetic flux +through this S5 okay and so electric + + align:start position:0% +through this S5 okay and so electric + + + align:start position:0% +through this S5 okay and so electric +charge would + + align:start position:0% +charge would + + + align:start position:0% +charge would +be just the five + + align:start position:0% +be just the five + + + align:start position:0% +be just the five +form surrounding through + + align:start position:0% +form surrounding through + + + align:start position:0% +form surrounding through +it and uh and uh uh uh um magnetic + + align:start position:0% +it and uh and uh uh uh um magnetic + + + align:start position:0% +it and uh and uh uh uh um magnetic +charge would + + align:start position:0% + + + + align:start position:0% + +be just uh uh um right why is the Dual + + align:start position:0% +be just uh uh um right why is the Dual + + + align:start position:0% +be just uh uh um right why is the Dual +of a five form is one form just just + + align:start position:0% +of a five form is one form just just + + + align:start position:0% +of a five form is one form just just +like the relation between these + + align:start position:0% +like the relation between these + + + align:start position:0% +like the relation between these +two + + align:start position:0% +two + + + align:start position:0% +two +okay and now because of self Duality + + align:start position:0% + + + + align:start position:0% + +condition then it must be the same so + + align:start position:0% +condition then it must be the same so + + + align:start position:0% +condition then it must be the same so +that means for this re brain the + + align:start position:0% +that means for this re brain the + + + align:start position:0% +that means for this re brain the +electric and magnetic charge must be the + + align:start position:0% +electric and magnetic charge must be the + + + align:start position:0% +electric and magnetic charge must be the +same + + align:start position:0% +same + + + align:start position:0% +same +okay and also for higher dimensional + + align:start position:0% + + + + align:start position:0% + +object same why not it's because F5 you + + align:start position:0% +object same why not it's because F5 you + + + align:start position:0% +object same why not it's because F5 you +F5 star + + align:start position:0% +F5 star + + + align:start position:0% +F5 star +it's because of that because of that + + align:start position:0% +it's because of that because of that + + + align:start position:0% +it's because of that because of that +self du condition + + align:start position:0% +self du condition + + + align:start position:0% +self du condition +yeah so Electric magnetic charge of the + + align:start position:0% +yeah so Electric magnetic charge of the + + + align:start position:0% +yeah so Electric magnetic charge of the +this R must be the same they must carry + + align:start position:0% +this R must be the same they must carry + + + align:start position:0% +this R must be the same they must carry +both electric and magnetic + + align:start position:0% +both electric and magnetic + + + align:start position:0% +both electric and magnetic +charge and now this direct quation + + align:start position:0% + + + + align:start position:0% + +condition also + + align:start position:0% +condition also + + + align:start position:0% +condition also +works for higher dimensional + + align:start position:0% +works for higher dimensional + + + align:start position:0% +works for higher dimensional +objects and again it's a very simple + + align:start position:0% +objects and again it's a very simple + + + align:start position:0% +objects and again it's a very simple +exercise to do it + + align:start position:0% +exercise to do it + + + align:start position:0% +exercise to do it +very simple exercise to General + + align:start position:0% +very simple exercise to General + + + align:start position:0% +very simple exercise to General +generalize The Rock's argument to higher + + align:start position:0% +generalize The Rock's argument to higher + + + align:start position:0% +generalize The Rock's argument to higher +Dimension again it just related how you + + align:start position:0% +Dimension again it just related how you + + + align:start position:0% +Dimension again it just related how you +treat those higher dimensional forms + + align:start position:0% +treat those higher dimensional forms + + + align:start position:0% +treat those higher dimensional forms +ex again it's a very simple step but + + align:start position:0% +ex again it's a very simple step but + + + align:start position:0% +ex again it's a very simple step but +it's a very important + + align:start position:0% +it's a very important + + + align:start position:0% +it's a very important +step so that tells + + align:start position:0% +step so that tells + + + align:start position:0% +step so that tells +me that for this re brain which is + + align:start position:0% +me that for this re brain which is + + + align:start position:0% +me that for this re brain which is +selfdual which is carry both INRI and + + align:start position:0% +selfdual which is carry both INRI and + + + align:start position:0% +selfdual which is carry both INRI and +magnetic + + align:start position:0% +magnetic + + + align:start position:0% +magnetic +charge then you have to satisfy this + + align:start position:0% +charge then you have to satisfy this + + + align:start position:0% +charge then you have to satisfy this +quation condition then that means the + + align:start position:0% +quation condition then that means the + + + align:start position:0% +quation condition then that means the +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +single this + + align:start position:0% +single this + + + align:start position:0% +single this +rebrin the minimal charged object must + + align:start position:0% +rebrin the minimal charged object must + + + align:start position:0% +rebrin the minimal charged object must +be the charge must be square otk 2 + + align:start position:0% +be the charge must be square otk 2 + + + align:start position:0% +be the charge must be square otk 2 +pi + + align:start position:0% +pi + + + align:start position:0% +pi +okay and for n of + + align:start position:0% +okay and for n of + + + align:start position:0% +okay and for n of +them so must be G3 = to Q3 = to 2 + + align:start position:0% +them so must be G3 = to Q3 = to 2 + + + align:start position:0% +them so must be G3 = to Q3 = to 2 +pi + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so now we have specified the analog + + align:start position:0% +so so now we have specified the analog + + + align:start position:0% +so so now we have specified the analog +for the for and M those conditions okay + + align:start position:0% +for the for and M those conditions okay + + + align:start position:0% +for the for and M those conditions okay +for uh now we also have to specify the + + align:start position:0% +for uh now we also have to specify the + + + align:start position:0% +for uh now we also have to specify the +mass of the this rebrin so as we + + align:start position:0% +mass of the this rebrin so as we + + + align:start position:0% +mass of the this rebrin so as we +discussed before tension of the dist re + + align:start position:0% + + + + align:start position:0% + +brain tension of a de + + align:start position:0% +brain tension of a de + + + align:start position:0% +brain tension of a de +brain should be proportional to one over + + align:start position:0% +brain should be proportional to one over + + + align:start position:0% +brain should be proportional to one over +G string okay that's you also did in + + align:start position:0% +G string okay that's you also did in + + + align:start position:0% +G string okay that's you also did in +your P set and again you + + align:start position:0% +your P set and again you + + + align:start position:0% +your P set and again you +can by doing a precise calculation you + + align:start position:0% +can by doing a precise calculation you + + + align:start position:0% +can by doing a precise calculation you +can work out the precise prefactors it + + align:start position:0% +can work out the precise prefactors it + + + align:start position:0% +can work out the precise prefactors it +turns out it turns out actually to be + + align:start position:0% +turns out it turns out actually to be + + + align:start position:0% +turns out it turns out actually to be +the following + + align:start position:0% +the following + + + align:start position:0% +the following +form uh to be the following form is the + + align:start position:0% +form uh to be the following form is the + + + align:start position:0% +form uh to be the following form is the +Q3 divided by 16 Pi + + align:start position:0% + + + + align:start position:0% + +GN okay and and the GN is g g string + + align:start position:0% +GN okay and and the GN is g g string + + + align:start position:0% +GN okay and and the GN is g g string +Square so if it translate into + + align:start position:0% +Square so if it translate into + + + align:start position:0% +Square so if it translate into +so for n this rein then would be n ided + + align:start position:0% +so for n this rein then would be n ided + + + align:start position:0% +so for n this rein then would be n ided +by 2 pi Cub GS Alpha Prime Square okay + + align:start position:0% +by 2 pi Cub GS Alpha Prime Square okay + + + align:start position:0% +by 2 pi Cub GS Alpha Prime Square okay +so so this GS Alpha Prime Square we know + + align:start position:0% +so so this GS Alpha Prime Square we know + + + align:start position:0% +so so this GS Alpha Prime Square we know +on General ground so GS with one over GS + + align:start position:0% +on General ground so GS with one over GS + + + align:start position:0% +on General ground so GS with one over GS +Bel on General ground and Alpha Prime + + align:start position:0% +Bel on General ground and Alpha Prime + + + align:start position:0% +Bel on General ground and Alpha Prime +Square just from dimensional analysis + + align:start position:0% +Square just from dimensional analysis + + + align:start position:0% +Square just from dimensional analysis +because this is a threedimensional + + align:start position:0% +because this is a threedimensional + + + align:start position:0% +because this is a threedimensional +object the tension is ATT tension we + + align:start position:0% +object the tension is ATT tension we + + + align:start position:0% +object the tension is ATT tension we +have mass Dimension four so that's why + + align:start position:0% +have mass Dimension four so that's why + + + align:start position:0% +have mass Dimension four so that's why +you have one over Alpha Prime Square + + align:start position:0% +you have one over Alpha Prime Square + + + align:start position:0% +you have one over Alpha Prime Square +here and then than the other 2 pi Cube + + align:start position:0% +here and then than the other 2 pi Cube + + + align:start position:0% +here and then than the other 2 pi Cube +from precise calculations and you can + + align:start position:0% +from precise calculations and you can + + + align:start position:0% +from precise calculations and you can +also write it in this form so in terms + + align:start position:0% +also write it in this form so in terms + + + align:start position:0% +also write it in this form so in terms +of newon constant + + align:start position:0% +of newon constant + + + align:start position:0% +of newon constant +okay and the reason I write this form + + align:start position:0% +okay and the reason I write this form + + + align:start position:0% +okay and the reason I write this form +because this is a very special case and + + align:start position:0% +because this is a very special case and + + + align:start position:0% +because this is a very special case and +you see that the tension is actually + + align:start position:0% +you see that the tension is actually + + + align:start position:0% +you see that the tension is actually +precisely related to the charge and + + align:start position:0% +precisely related to the charge and + + + align:start position:0% +precisely related to the charge and +divided by the square root of lutant + + align:start position:0% +divided by the square root of lutant + + + align:start position:0% +divided by the square root of lutant +constant and turns out only special + + align:start position:0% +constant and turns out only special + + + align:start position:0% +constant and turns out only special +object only special object have this + + align:start position:0% +object only special object have this + + + align:start position:0% +object only special object have this +kind of property and this so- called BPS + + align:start position:0% +kind of property and this so- called BPS + + + align:start position:0% +kind of property and this so- called BPS +objects will not go to there it's ready + + align:start position:0% +objects will not go to there it's ready + + + align:start position:0% +objects will not go to there it's ready +to those brain a super + + align:start position:0% + + + + align:start position:0% + +symmetric anyway so so these are the + + align:start position:0% +symmetric anyway so so these are the + + + align:start position:0% +symmetric anyway so so these are the +mass of the essentially this is the mass + + align:start position:0% +mass of the essentially this is the mass + + + align:start position:0% +mass of the essentially this is the mass +of the brain and this are the charge of + + align:start position:0% +of the brain and this are the charge of + + + align:start position:0% +of the brain and this are the charge of +the + + align:start position:0% +the + + + align:start position:0% +the +brain when you specify the charge then + + align:start position:0% +brain when you specify the charge then + + + align:start position:0% +brain when you specify the charge then +those fields then those flux areally + + align:start position:0% +those fields then those flux areally + + + align:start position:0% +those fields then those flux areally +determined and then then the then the C4 + + align:start position:0% +determined and then then the then the C4 + + + align:start position:0% +determined and then then the then the C4 +potential are uniquely + + align:start position:0% +potential are uniquely + + + align:start position:0% +potential are uniquely +determined up to gaug symmetry are + + align:start position:0% +determined up to gaug symmetry are + + + align:start position:0% +determined up to gaug symmetry are +determined and then now you can plug + + align:start position:0% +determined and then now you can plug + + + align:start position:0% +determined and then now you can plug +into the generation of the einin you + + align:start position:0% +into the generation of the einin you + + + align:start position:0% +into the generation of the einin you +equation to work out the geometry okay + + align:start position:0% +equation to work out the geometry okay + + + align:start position:0% +equation to work out the geometry okay +so so again the Symmetry + + align:start position:0% +so so again the Symmetry + + + align:start position:0% +so so again the Symmetry +here yeah so I won't have time for the + + align:start position:0% +here yeah so I won't have time for the + + + align:start position:0% +here yeah so I won't have time for the +bottom line so that's okay um so the + + align:start position:0% + + + + align:start position:0% + +Symmetry preserved by the de brain by + + align:start position:0% +Symmetry preserved by the de brain by + + + align:start position:0% +Symmetry preserved by the de brain by +this re brain as we said before similar + + align:start position:0% +this re brain as we said before similar + + + align:start position:0% +this re brain as we said before similar +to all de brains is you have a pite + + align:start position:0% +to all de brains is you have a pite + + + align:start position:0% +to all de brains is you have a pite +symmetry along the brain + + align:start position:0% +symmetry along the brain + + + align:start position:0% +symmetry along the brain +Direction and then you have rotation + + align:start position:0% +Direction and then you have rotation + + + align:start position:0% +Direction and then you have rotation +symmetry in the transverse Direction + + align:start position:0% +symmetry in the transverse Direction + + + align:start position:0% +symmetry in the transverse Direction +along the brain so the transverse we + + align:start position:0% +along the brain so the transverse we + + + align:start position:0% +along the brain so the transverse we +have six Dimension so there's s so6 uh + + align:start position:0% +have six Dimension so there's s so6 uh + + + align:start position:0% +have six Dimension so there's s so6 uh +directions you can rotate in the and + + align:start position:0% +directions you can rotate in the and + + + align:start position:0% +directions you can rotate in the and +then then you have P symmetry in the one + + align:start position:0% +then then you have P symmetry in the one + + + align:start position:0% +then then you have P symmetry in the one +three Direction So based on these + + align:start position:0% +three Direction So based on these + + + align:start position:0% +three Direction So based on these +symmetries you can write + + align:start position:0% +symmetries you can write + + + align:start position:0% +symmetries you can write +down what the matric looks like you can + + align:start position:0% +down what the matric looks like you can + + + align:start position:0% +down what the matric looks like you can +write down answers for the matric okay + + align:start position:0% +write down answers for the matric okay + + + align:start position:0% +write down answers for the matric okay +just like what here you can write down + + align:start position:0% +just like what here you can write down + + + align:start position:0% +just like what here you can write down +the answers for the uh for the matric of + + align:start position:0% +the answers for the uh for the matric of + + + align:start position:0% +the answers for the uh for the matric of +a point particle B based on symmetry so + + align:start position:0% +a point particle B based on symmetry so + + + align:start position:0% +a point particle B based on symmetry so +here you can uh write down ansers uh + + align:start position:0% +here you can uh write down ansers uh + + + align:start position:0% +here you can uh write down ansers uh +for the matric based on symmetry so + + align:start position:0% +for the matric based on symmetry so + + + align:start position:0% +for the matric based on symmetry so +first you should have a + + align:start position:0% +first you should have a + + + align:start position:0% +first you should have a +part which is + + align:start position:0% +part which is + + + align:start position:0% +part which is +preserve PCR + + align:start position:0% + + + + align:start position:0% + +symmetry means this part can only be + + align:start position:0% +symmetry means this part can only be + + + align:start position:0% +symmetry means this part can only be +this form say along the brain Direction + + align:start position:0% +this form say along the brain Direction + + + align:start position:0% +this form say along the brain Direction +can only be this form times some overall + + align:start position:0% +can only be this form times some overall + + + align:start position:0% +can only be this form times some overall +factor which depend on R so R is the + + align:start position:0% +factor which depend on R so R is the + + + align:start position:0% +factor which depend on R so R is the +transverse radius from the brain and + + align:start position:0% +transverse radius from the brain and + + + align:start position:0% +transverse radius from the brain and +then the other Dimension must + + align:start position:0% +then the other Dimension must + + + align:start position:0% +then the other Dimension must +be then the other dimension must be + + align:start position:0% +be then the other dimension must be + + + align:start position:0% +be then the other dimension must be +spical symmetric so you can have a lot + + align:start position:0% +spical symmetric so you can have a lot + + + align:start position:0% +spical symmetric so you can have a lot +of factors and then d r squ and r Square + + align:start position:0% +of factors and then d r squ and r Square + + + align:start position:0% +of factors and then d r squ and r Square +D Omega 5 Square so this is S5 + + align:start position:0% +D Omega 5 Square so this is S5 + + + align:start position:0% +D Omega 5 Square so this is S5 +surrounding the brain and then this is a + + align:start position:0% +surrounding the brain and then this is a + + + align:start position:0% +surrounding the brain and then this is a +radial Direction so this is the only uh + + align:start position:0% +radial Direction so this is the only uh + + + align:start position:0% +radial Direction so this is the only uh +form of the + + align:start position:0% +form of the + + + align:start position:0% +form of the +metric and essentially again as in the + + align:start position:0% +metric and essentially again as in the + + + align:start position:0% +metric and essentially again as in the +charge particle case you need to + + align:start position:0% +charge particle case you need to + + + align:start position:0% +charge particle case you need to +determine these two functions okay which + + align:start position:0% +determine these two functions okay which + + + align:start position:0% +determine these two functions okay which +you can plug in Einstein equation just + + align:start position:0% +you can plug in Einstein equation just + + + align:start position:0% +you can plug in Einstein equation just +determine these two + + align:start position:0% +determine these two + + + align:start position:0% +determine these two +functions so let me just write down the + + align:start position:0% +functions so let me just write down the + + + align:start position:0% +functions so let me just write down the +form of those functions then we discuss + + align:start position:0% +form of those functions then we discuss + + + align:start position:0% +form of those functions then we discuss +what they mean uh next + + align:start position:0% + + + + align:start position:0% + +time somehow this year I'm consistently + + align:start position:0% +time somehow this year I'm consistently + + + align:start position:0% +time somehow this year I'm consistently +much much slower than what I did before + + align:start position:0% +much much slower than what I did before + + + align:start position:0% +much much slower than what I did before +maybe I'm explaining physics + + align:start position:0% + + + + align:start position:0% + +better yeah um anyway so so now it's + + align:start position:0% +better yeah um anyway so so now it's + + + align:start position:0% +better yeah um anyway so so now it's +just a mechanical exercise sides you + + align:start position:0% +just a mechanical exercise sides you + + + align:start position:0% +just a mechanical exercise sides you +plug in these answers into the Einstein + + align:start position:0% +plug in these answers into the Einstein + + + align:start position:0% +plug in these answers into the Einstein +equation then you can find the two + + align:start position:0% +equation then you can find the two + + + align:start position:0% +equation then you can find the two +equations for for f and H then you can + + align:start position:0% +equations for for f and H then you can + + + align:start position:0% +equations for for f and H then you can +solve it in the old days when hor and + + align:start position:0% +solve it in the old days when hor and + + + align:start position:0% +solve it in the old days when hor and +singer did it uh uh maybe they don't + + align:start position:0% +singer did it uh uh maybe they don't + + + align:start position:0% +singer did it uh uh maybe they don't +maybe they did not have Mathematica yet + + align:start position:0% +maybe they did not have Mathematica yet + + + align:start position:0% +maybe they did not have Mathematica yet +but nowadays you can do it using + + align:start position:0% +but nowadays you can do it using + + + align:start position:0% +but nowadays you can do it using +Mathematica if you have the right + + align:start position:0% +Mathematica if you have the right + + + align:start position:0% +Mathematica if you have the right +program you can do it in five + + align:start position:0% +program you can do it in five + + + align:start position:0% +program you can do it in five +minutes but in the old days they were + + align:start position:0% +minutes but in the old days they were + + + align:start position:0% +minutes but in the old days they were +friend with wfr maybe they already have + + align:start position:0% +friend with wfr maybe they already have + + + align:start position:0% +friend with wfr maybe they already have +the program at that time anyway so so it + + align:start position:0% +the program at that time anyway so so it + + + align:start position:0% +the program at that time anyway so so it +was a more unch exercise to do at the + + align:start position:0% +was a more unch exercise to do at the + + + align:start position:0% +was a more unch exercise to do at the +time so you find actually the answer is + + align:start position:0% +time so you find actually the answer is + + + align:start position:0% +time so you find actually the answer is +very simple turns out both F and H they + + align:start position:0% +very simple turns out both F and H they + + + align:start position:0% +very simple turns out both F and H they +just yeah can be WR in the following + + align:start position:0% + + + + align:start position:0% + +form so + + align:start position:0% +form so + + + align:start position:0% +form so +H so H is lot function H is just a + + align:start position:0% +H so H is lot function H is just a + + + align:start position:0% +H so H is lot function H is just a +harmonic + + align:start position:0% + + + + align:start position:0% + +function + + align:start position:0% +function + + + align:start position:0% +function +and R to the power 4 is given by some + + align:start position:0% +and R to the power 4 is given by some + + + align:start position:0% +and R to the power 4 is given by some +constant some + + align:start position:0% + + + + align:start position:0% + +constant + + align:start position:0% +constant + + + align:start position:0% +constant +GN new Newton constant times the this + + align:start position:0% +GN new Newton constant times the this + + + align:start position:0% +GN new Newton constant times the this +reent tension times n and can also be + + align:start position:0% +reent tension times n and can also be + + + align:start position:0% +reent tension times n and can also be +written as 4 Pi GSN Alp Prime + + align:start position:0% +written as 4 Pi GSN Alp Prime + + + align:start position:0% +written as 4 Pi GSN Alp Prime +squar + + align:start position:0% +squar + + + align:start position:0% +squar +okay so turn out those function are very + + align:start position:0% +okay so turn out those function are very + + + align:start position:0% +okay so turn out those function are very +simple they're just square root of a + + align:start position:0% +simple they're just square root of a + + + align:start position:0% +simple they're just square root of a +harmonic function so this is a harmonic + + align:start position:0% +harmonic function so this is a harmonic + + + align:start position:0% +harmonic function so this is a harmonic +function for the transverse R six so if + + align:start position:0% +function for the transverse R six so if + + + align:start position:0% +function for the transverse R six so if +you solve say a coolant problem and and + + align:start position:0% +you solve say a coolant problem and and + + + align:start position:0% +you solve say a coolant problem and and +that would be the solution this is the + + align:start position:0% +that would be the solution this is the + + + align:start position:0% +that would be the solution this is the +harmonic yeah so this is generation of + + align:start position:0% +harmonic yeah so this is generation of + + + align:start position:0% +harmonic yeah so this is generation of +one / R potential so this is just + + align:start position:0% +one / R potential so this is just + + + align:start position:0% +one / R potential so this is just +generation of one over R potential and + + align:start position:0% +generation of one over R potential and + + + align:start position:0% +generation of one over R potential and +then f and g is very simply related to + + align:start position:0% +then f and g is very simply related to + + + align:start position:0% +then f and g is very simply related to +this by square root and this uh this + + align:start position:0% +this by square root and this uh this + + + align:start position:0% +this by square root and this uh this +constant R to the^ 4 so this is not + + align:start position:0% +constant R to the^ 4 so this is not + + + align:start position:0% +constant R to the^ 4 so this is not +curvature this is just some constant uh + + align:start position:0% +curvature this is just some constant uh + + + align:start position:0% +curvature this is just some constant uh +stand + + align:start position:0% +stand + + + align:start position:0% +stand +I'm using the standard rotation and then + + align:start position:0% +I'm using the standard rotation and then + + + align:start position:0% +I'm using the standard rotation and then +this can be this is just related to the + + align:start position:0% +this can be this is just related to the + + + align:start position:0% +this can be this is just related to the +mass of the + + align:start position:0% +mass of the + + + align:start position:0% +mass of the +brain uh a mass of the brain of course + + align:start position:0% +brain uh a mass of the brain of course + + + align:start position:0% +brain uh a mass of the brain of course +proportional to + + align:start position:0% +proportional to + + + align:start position:0% +proportional to +n um yeah in this Cas is mass the charge + + align:start position:0% +n um yeah in this Cas is mass the charge + + + align:start position:0% +n um yeah in this Cas is mass the charge +is Mass sorry the charge is mass yeah + + align:start position:0% +is Mass sorry the charge is mass yeah + + + align:start position:0% +is Mass sorry the charge is mass yeah +sorry the okay is the charge considered + + align:start position:0% +sorry the okay is the charge considered + + + align:start position:0% +sorry the okay is the charge considered +on the D brain mass or massive + + align:start position:0% +on the D brain mass or massive + + + align:start position:0% +on the D brain mass or massive +no no no charge charger just charge what + + align:start position:0% +no no no charge charger just charge what + + + align:start position:0% +no no no charge charger just charge what +do you mean by + + align:start position:0% + + + + align:start position:0% + +charge okay yeah this is just a charge + + align:start position:0% +charge okay yeah this is just a charge + + + align:start position:0% +charge okay yeah this is just a charge +carried by this rebr oh yeah anyway so + + align:start position:0% +carried by this rebr oh yeah anyway so + + + align:start position:0% +carried by this rebr oh yeah anyway so +so so this + + align:start position:0% +so so this + + + align:start position:0% +so so this +R4 is just like GN times the tension uh + + align:start position:0% +R4 is just like GN times the tension uh + + + align:start position:0% +R4 is just like GN times the tension uh +n times the tension if we have n n + + align:start position:0% +n times the tension if we have n n + + + align:start position:0% +n times the tension if we have n n +object just yeah so this is what you + + align:start position:0% +object just yeah so this is what you + + + align:start position:0% +object just yeah so this is what you +familiar with with the SW black ho SW + + align:start position:0% +familiar with with the SW black ho SW + + + align:start position:0% +familiar with with the SW black ho SW +matric just doent constant times mass so + + align:start position:0% +matric just doent constant times mass so + + + align:start position:0% +matric just doent constant times mass so +this is just generalization of that + + align:start position:0% +this is just generalization of that + + + align:start position:0% +this is just generalization of that +Newton constant times the tension and + + align:start position:0% +Newton constant times the tension and + + + align:start position:0% +Newton constant times the tension and +you have Ence you just multiply n and + + align:start position:0% +you have Ence you just multiply n and + + + align:start position:0% +you have Ence you just multiply n and +you can write it if you write everything + + align:start position:0% +you can write it if you write everything + + + align:start position:0% +you can write it if you write everything +ter GS this is proportional to GS squ + + align:start position:0% +ter GS this is proportional to GS squ + + + align:start position:0% +ter GS this is proportional to GS squ +this is propor to one over GS so then + + align:start position:0% +this is propor to one over GS so then + + + align:start position:0% +this is propor to one over GS so then +end up this thing is proportional to GS + + align:start position:0% +end up this thing is proportional to GS + + + align:start position:0% +end up this thing is proportional to GS +okay okay I will stop here \ No newline at end of file diff --git a/0DCrIAxEv_Y.txt b/0DCrIAxEv_Y.txt new file mode 100644 index 0000000000000000000000000000000000000000..f8dad96784f4e043df8f63f30b0445e97dd0acf7 --- /dev/null +++ b/0DCrIAxEv_Y.txt @@ -0,0 +1,10219 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu well welcome back for the + + align:start position:0% +ocw.mit.edu well welcome back for the + + + align:start position:0% +ocw.mit.edu well welcome back for the +for the last hour in this uh in this + + align:start position:0% +for the last hour in this uh in this + + + align:start position:0% +for the last hour in this uh in this +course uh and we've discussed all kinds + + align:start position:0% +course uh and we've discussed all kinds + + + align:start position:0% +course uh and we've discussed all kinds +of things about lasers certainly not + + align:start position:0% +of things about lasers certainly not + + + align:start position:0% +of things about lasers certainly not +everything I haven't touched on Q + + align:start position:0% +everything I haven't touched on Q + + + align:start position:0% +everything I haven't touched on Q +switching uh cavity dumping and uh + + align:start position:0% +switching uh cavity dumping and uh + + + align:start position:0% +switching uh cavity dumping and uh +techniques for mode locking and so on + + align:start position:0% +techniques for mode locking and so on + + + align:start position:0% +techniques for mode locking and so on +but I think uh I hope if if you didn't + + align:start position:0% +but I think uh I hope if if you didn't + + + align:start position:0% +but I think uh I hope if if you didn't +have too much of a background now at + + align:start position:0% +have too much of a background now at + + + align:start position:0% +have too much of a background now at +least you can see that there's nothing + + align:start position:0% +least you can see that there's nothing + + + align:start position:0% +least you can see that there's nothing +that magical about lasers they all makes + + align:start position:0% +that magical about lasers they all makes + + + align:start position:0% +that magical about lasers they all makes +sense and uh and if you were on some + + align:start position:0% +sense and uh and if you were on some + + + align:start position:0% +sense and uh and if you were on some +desert island with a bag of tricks you + + align:start position:0% +desert island with a bag of tricks you + + + align:start position:0% +desert island with a bag of tricks you +could probably create a laser for + + align:start position:0% +could probably create a laser for + + + align:start position:0% +could probably create a laser for +yourself now as I mentioned earlier I + + align:start position:0% +yourself now as I mentioned earlier I + + + align:start position:0% +yourself now as I mentioned earlier I +want to change topics now I want to + + align:start position:0% +want to change topics now I want to + + + align:start position:0% +want to change topics now I want to +switch to fiber optics because fiber + + align:start position:0% +switch to fiber optics because fiber + + + align:start position:0% +switch to fiber optics because fiber +optics is playing a key role in our + + align:start position:0% +optics is playing a key role in our + + + align:start position:0% +optics is playing a key role in our +lives today and I think it's it's good + + align:start position:0% +lives today and I think it's it's good + + + align:start position:0% +lives today and I think it's it's good +for for all sorts of people to know uh + + align:start position:0% +for for all sorts of people to know uh + + + align:start position:0% +for for all sorts of people to know uh +how uh how fiber optics uh how it works + + align:start position:0% +how uh how fiber optics uh how it works + + + align:start position:0% +how uh how fiber optics uh how it works +you know how it works and and some of + + align:start position:0% +you know how it works and and some of + + + align:start position:0% +you know how it works and and some of +the uh developments have been going on + + align:start position:0% +the uh developments have been going on + + + align:start position:0% +the uh developments have been going on +in in fiber optics and maybe a few words + + align:start position:0% +in in fiber optics and maybe a few words + + + align:start position:0% +in in fiber optics and maybe a few words +about some applications of uh fiber + + align:start position:0% +about some applications of uh fiber + + + align:start position:0% +about some applications of uh fiber +optics so so here is the the uh very + + align:start position:0% +optics so so here is the the uh very + + + align:start position:0% +optics so so here is the the uh very +short course on on basics of fiber + + align:start position:0% +short course on on basics of fiber + + + align:start position:0% +short course on on basics of fiber +optics so the first question one asked + + align:start position:0% +optics so the first question one asked + + + align:start position:0% +optics so the first question one asked +well what's a fiber all right now + + align:start position:0% +well what's a fiber all right now + + + align:start position:0% +well what's a fiber all right now +fibers uh have been developed for for + + align:start position:0% +fibers uh have been developed for for + + + align:start position:0% +fibers uh have been developed for for +many years way before uh lasers and they + + align:start position:0% +many years way before uh lasers and they + + + align:start position:0% +many years way before uh lasers and they +basically look look like this if you + + align:start position:0% +basically look look like this if you + + + align:start position:0% +basically look look like this if you +look from from the end they look like + + align:start position:0% +look from from the end they look like + + + align:start position:0% +look from from the end they look like +have a core you see which is one type of + + align:start position:0% +have a core you see which is one type of + + + align:start position:0% +have a core you see which is one type of +glass and of certain index let's say + + align:start position:0% +glass and of certain index let's say + + + align:start position:0% +glass and of certain index let's say +index N1 and surrounded by another glass + + align:start position:0% +index N1 and surrounded by another glass + + + align:start position:0% +index N1 and surrounded by another glass +uh of index N2 called the CL cladding + + align:start position:0% +uh of index N2 called the CL cladding + + + align:start position:0% +uh of index N2 called the CL cladding +and then the cladding is surrounded by a + + align:start position:0% +and then the cladding is surrounded by a + + + align:start position:0% +and then the cladding is surrounded by a +jacket and depends on the type of + + align:start position:0% +jacket and depends on the type of + + + align:start position:0% +jacket and depends on the type of +material that you use but whatever the + + align:start position:0% +material that you use but whatever the + + + align:start position:0% +material that you use but whatever the +jacket then protects the uh protects the + + align:start position:0% +jacket then protects the uh protects the + + + align:start position:0% +jacket then protects the uh protects the +clading the index the refractive index + + align:start position:0% +clading the index the refractive index + + + align:start position:0% +clading the index the refractive index +N1 of the core is bigger than N2 uh + + align:start position:0% +N1 of the core is bigger than N2 uh + + + align:start position:0% +N1 of the core is bigger than N2 uh +sometimes N2 the the the clading + + align:start position:0% +sometimes N2 the the the clading + + + align:start position:0% +sometimes N2 the the the clading +material is just plain silicon + + align:start position:0% +material is just plain silicon + + + align:start position:0% +material is just plain silicon +dioxide uh and the index uh uh the + + align:start position:0% +dioxide uh and the index uh uh the + + + align:start position:0% +dioxide uh and the index uh uh the +material in in the core is silicon + + align:start position:0% +material in in the core is silicon + + + align:start position:0% +material in in the core is silicon +dioxide plus some impurity with geranium + + align:start position:0% +dioxide plus some impurity with geranium + + + align:start position:0% +dioxide plus some impurity with geranium +dioxide to raise to raise the index the + + align:start position:0% +dioxide to raise to raise the index the + + + align:start position:0% +dioxide to raise to raise the index the +question is what's going on in here why + + align:start position:0% +question is what's going on in here why + + + align:start position:0% +question is what's going on in here why +play with with all the these indices so + + align:start position:0% +play with with all the these indices so + + + align:start position:0% +play with with all the these indices so +the the key thing here is a uh total + + align:start position:0% +the the key thing here is a uh total + + + align:start position:0% +the the key thing here is a uh total +internal reflection all right total the + + align:start position:0% +internal reflection all right total the + + + align:start position:0% +internal reflection all right total the +propagation of light in fibers based on + + align:start position:0% +propagation of light in fibers based on + + + align:start position:0% +propagation of light in fibers based on +total internal reflection so let's let's + + align:start position:0% +total internal reflection so let's let's + + + align:start position:0% +total internal reflection so let's let's +then uh review it uh here's a ray of + + align:start position:0% +then uh review it uh here's a ray of + + + align:start position:0% +then uh review it uh here's a ray of +light uh hitting the uh surface the + + align:start position:0% +light uh hitting the uh surface the + + + align:start position:0% +light uh hitting the uh surface the +interface here between N1 and N2 between + + align:start position:0% +interface here between N1 and N2 between + + + align:start position:0% +interface here between N1 and N2 between +the core and the and the cladding if + + align:start position:0% +the core and the and the cladding if + + + align:start position:0% +the core and the and the cladding if +this angle if this incident angle is + + align:start position:0% +this angle if this incident angle is + + + align:start position:0% +this angle if this incident angle is +bigger than the critical angle then the + + align:start position:0% +bigger than the critical angle then the + + + align:start position:0% +bigger than the critical angle then the +light will be reflected and bounce + + align:start position:0% +light will be reflected and bounce + + + align:start position:0% +light will be reflected and bounce +around until it comes out the other + + align:start position:0% +around until it comes out the other + + + align:start position:0% +around until it comes out the other +end and uh because just like going from + + align:start position:0% +end and uh because just like going from + + + align:start position:0% +end and uh because just like going from +glass uh to Air and the the critical + + align:start position:0% +glass uh to Air and the the critical + + + align:start position:0% +glass uh to Air and the the critical +angle is given as we remember from high + + align:start position:0% +angle is given as we remember from high + + + align:start position:0% +angle is given as we remember from high +school as s to minus1 of N2 over N1 + + align:start position:0% +school as s to minus1 of N2 over N1 + + + align:start position:0% +school as s to minus1 of N2 over N1 +where N2 is the in the smaller index and + + align:start position:0% +where N2 is the in the smaller index and + + + align:start position:0% +where N2 is the in the smaller index and +N1 is the is the bigger one if this + + align:start position:0% +N1 is the is the bigger one if this + + + align:start position:0% +N1 is the is the bigger one if this +angle of incidence is smaller than Theta + + align:start position:0% +angle of incidence is smaller than Theta + + + align:start position:0% +angle of incidence is smaller than Theta +critical then there will be some + + align:start position:0% +critical then there will be some + + + align:start position:0% +critical then there will be some +transmission of light and not all the + + align:start position:0% +transmission of light and not all the + + + align:start position:0% +transmission of light and not all the +light will be will be + + align:start position:0% +light will be will be + + + align:start position:0% +light will be will be +reflected the uh just to remind you some + + align:start position:0% +reflected the uh just to remind you some + + + align:start position:0% +reflected the uh just to remind you some +more uh of uh what's going on let me + + align:start position:0% +more uh of uh what's going on let me + + + align:start position:0% +more uh of uh what's going on let me +remind you of the of the perfect mirror + + align:start position:0% +remind you of the of the perfect mirror + + + align:start position:0% +remind you of the of the perfect mirror +when I have a perfect mirror the light + + align:start position:0% +when I have a perfect mirror the light + + + align:start position:0% +when I have a perfect mirror the light +comes in then essentially close to 100% + + align:start position:0% +comes in then essentially close to 100% + + + align:start position:0% +comes in then essentially close to 100% +the light gets reflected and the + + align:start position:0% +the light gets reflected and the + + + align:start position:0% +the light gets reflected and the +reflectivity is close to 100% as I say + + align:start position:0% +reflectivity is close to 100% as I say + + + align:start position:0% +reflectivity is close to 100% as I say +is one as a function of angle of of of + + align:start position:0% +is one as a function of angle of of of + + + align:start position:0% +is one as a function of angle of of of +incidents but if you have again the the + + align:start position:0% +incidents but if you have again the the + + + align:start position:0% +incidents but if you have again the the +glass air interface now we're coming + + align:start position:0% +glass air interface now we're coming + + + align:start position:0% +glass air interface now we're coming +from the glass side then as we vary this + + align:start position:0% +from the glass side then as we vary this + + + align:start position:0% +from the glass side then as we vary this +this angle the angle of incidence then + + align:start position:0% +this angle the angle of incidence then + + + align:start position:0% +this angle the angle of incidence then +the the reflectivity uh uh of this + + align:start position:0% +the the reflectivity uh uh of this + + + align:start position:0% +the the reflectivity uh uh of this +interface then depends on the + + align:start position:0% +interface then depends on the + + + align:start position:0% +interface then depends on the +polarization but right now we're not + + align:start position:0% +polarization but right now we're not + + + align:start position:0% +polarization but right now we're not +going to get involved with polarization + + align:start position:0% +going to get involved with polarization + + + align:start position:0% +going to get involved with polarization +but basically starts let's say between + + align:start position:0% +but basically starts let's say between + + + align:start position:0% +but basically starts let's say between +glass air starts like 4% and for one + + align:start position:0% +glass air starts like 4% and for one + + + align:start position:0% +glass air starts like 4% and for one +polarization goes through zero which is + + align:start position:0% +polarization goes through zero which is + + + align:start position:0% +polarization goes through zero which is +the Brewster angle here and then Rises + + align:start position:0% +the Brewster angle here and then Rises + + + align:start position:0% +the Brewster angle here and then Rises +uh at the Theta critical to 100% and for + + align:start position:0% +uh at the Theta critical to 100% and for + + + align:start position:0% +uh at the Theta critical to 100% and for +the other + + align:start position:0% +the other + + + align:start position:0% +the other +polarization uh then it doesn't quite go + + align:start position:0% +polarization uh then it doesn't quite go + + + align:start position:0% +polarization uh then it doesn't quite go +to zero but again still rises and goes + + align:start position:0% +to zero but again still rises and goes + + + align:start position:0% +to zero but again still rises and goes +to 100% at the Theta critical so it + + align:start position:0% +to 100% at the Theta critical so it + + + align:start position:0% +to 100% at the Theta critical so it +doesn't matter which polarization the + + align:start position:0% +doesn't matter which polarization the + + + align:start position:0% +doesn't matter which polarization the +both polarization will go to 100% for + + align:start position:0% +both polarization will go to 100% for + + + align:start position:0% +both polarization will go to 100% for +Theta critical and and Beyond and that's + + align:start position:0% +Theta critical and and Beyond and that's + + + align:start position:0% +Theta critical and and Beyond and that's +what we take advantage of in fibers let + + align:start position:0% +what we take advantage of in fibers let + + + align:start position:0% +what we take advantage of in fibers let +me tell you this is really 100% because + + align:start position:0% +me tell you this is really 100% because + + + align:start position:0% +me tell you this is really 100% because +you wouldn't get such low loss fibers if + + align:start position:0% +you wouldn't get such low loss fibers if + + + align:start position:0% +you wouldn't get such low loss fibers if +this weren now the other interesting + + align:start position:0% +this weren now the other interesting + + + align:start position:0% +this weren now the other interesting +thing that I want to point out again + + align:start position:0% +thing that I want to point out again + + + align:start position:0% +thing that I want to point out again +from high school staff is that that + + align:start position:0% +from high school staff is that that + + + align:start position:0% +from high school staff is that that +there is what we call evanescent wave + + align:start position:0% +there is what we call evanescent wave + + + align:start position:0% +there is what we call evanescent wave +here there's a field that is propagates + + align:start position:0% +here there's a field that is propagates + + + align:start position:0% +here there's a field that is propagates +in the in the vacuum or in the air here + + align:start position:0% +in the in the vacuum or in the air here + + + align:start position:0% +in the in the vacuum or in the air here +uh but essentially just goes in and + + align:start position:0% +uh but essentially just goes in and + + + align:start position:0% +uh but essentially just goes in and +comes back again it's not a loss it's + + align:start position:0% +comes back again it's not a loss it's + + + align:start position:0% +comes back again it's not a loss it's +just that the uh the in when you have a + + align:start position:0% +just that the uh the in when you have a + + + align:start position:0% +just that the uh the in when you have a +glass air interface there is a field + + align:start position:0% +glass air interface there is a field + + + align:start position:0% +glass air interface there is a field +that does penetrate but is still not + + align:start position:0% +that does penetrate but is still not + + + align:start position:0% +that does penetrate but is still not +considered as a loss but and then and + + align:start position:0% +considered as a loss but and then and + + + align:start position:0% +considered as a loss but and then and +then uh but then comes back here and + + align:start position:0% +then uh but then comes back here and + + + align:start position:0% +then uh but then comes back here and +gives us 100% while in a perfect + + align:start position:0% +gives us 100% while in a perfect + + + align:start position:0% +gives us 100% while in a perfect +reflector there is no field present on + + align:start position:0% +reflector there is no field present on + + + align:start position:0% +reflector there is no field present on +the other side because the the light + + align:start position:0% +the other side because the the light + + + align:start position:0% +the other side because the the light +100% the light gets reflected at the + + align:start position:0% +100% the light gets reflected at the + + + align:start position:0% +100% the light gets reflected at the +interface okay so if you keep that in + + align:start position:0% +interface okay so if you keep that in + + + align:start position:0% +interface okay so if you keep that in +mind that there is an evanescent fi + + align:start position:0% +mind that there is an evanescent fi + + + align:start position:0% +mind that there is an evanescent fi +there's a field penetration into the + + align:start position:0% +there's a field penetration into the + + + align:start position:0% +there's a field penetration into the +lower index medium the smaller index + + align:start position:0% +lower index medium the smaller index + + + align:start position:0% +lower index medium the smaller index +medium in this case it's air all right + + align:start position:0% +medium in this case it's air all right + + + align:start position:0% +medium in this case it's air all right +so with this as uh as background now + + align:start position:0% +so with this as uh as background now + + + align:start position:0% +so with this as uh as background now +let's look at the the propagation in a + + align:start position:0% +let's look at the the propagation in a + + + align:start position:0% +let's look at the the propagation in a +in a fiber now uh uh it's not the like I + + align:start position:0% +in a fiber now uh uh it's not the like I + + + align:start position:0% +in a fiber now uh uh it's not the like I +showed you here exactly like I showed + + align:start position:0% +showed you here exactly like I showed + + + align:start position:0% +showed you here exactly like I showed +you is the ray the ray approximation but + + align:start position:0% +you is the ray the ray approximation but + + + align:start position:0% +you is the ray the ray approximation but +basically uh when you do the + + align:start position:0% +basically uh when you do the + + + align:start position:0% +basically uh when you do the +calculations what you get is a uh is a a + + align:start position:0% +calculations what you get is a uh is a a + + + align:start position:0% +calculations what you get is a uh is a a +uh a mode essentially like just like the + + align:start position:0% +uh a mode essentially like just like the + + + align:start position:0% +uh a mode essentially like just like the +one in lasers is a a field distribution + + align:start position:0% +one in lasers is a a field distribution + + + align:start position:0% +one in lasers is a a field distribution +here where that Peaks at the center of + + align:start position:0% +here where that Peaks at the center of + + + align:start position:0% +here where that Peaks at the center of +the core and also uh uh extends a little + + align:start position:0% +the core and also uh uh extends a little + + + align:start position:0% +the core and also uh uh extends a little +bit into the uh the evanescent Fe this + + align:start position:0% +bit into the uh the evanescent Fe this + + + align:start position:0% +bit into the uh the evanescent Fe this +is the evanescent Fe extends into the + + align:start position:0% +is the evanescent Fe extends into the + + + align:start position:0% +is the evanescent Fe extends into the +cladic so so uh so you can see this is + + align:start position:0% +cladic so so uh so you can see this is + + + align:start position:0% +cladic so so uh so you can see this is +the side of size of the core but you see + + align:start position:0% +the side of size of the core but you see + + + align:start position:0% +the side of size of the core but you see +the orange this orange if you can uh see + + align:start position:0% +the orange this orange if you can uh see + + + align:start position:0% +the orange this orange if you can uh see +it as orange it basically extends beyond + + align:start position:0% +it as orange it basically extends beyond + + + align:start position:0% +it as orange it basically extends beyond +the size of the core and that's what we + + align:start position:0% +the size of the core and that's what we + + + align:start position:0% +the size of the core and that's what we +call single mode uh propagation okay + + align:start position:0% +call single mode uh propagation okay + + + align:start position:0% +call single mode uh propagation okay +here's the field distribution here's the + + align:start position:0% +here's the field distribution here's the + + + align:start position:0% +here's the field distribution here's the +side of mode so it extends a little bit + + align:start position:0% +side of mode so it extends a little bit + + + align:start position:0% +side of mode so it extends a little bit +into into the cladding most of it let's + + align:start position:0% +into into the cladding most of it let's + + + align:start position:0% +into into the cladding most of it let's +say goes into the core part of it goes + + align:start position:0% +say goes into the core part of it goes + + + align:start position:0% +say goes into the core part of it goes +in the CL and propagates right down the + + align:start position:0% +in the CL and propagates right down the + + + align:start position:0% +in the CL and propagates right down the +fiber I mean this Ray idea is fine for + + align:start position:0% +fiber I mean this Ray idea is fine for + + + align:start position:0% +fiber I mean this Ray idea is fine for +explanation but basically when you when + + align:start position:0% +explanation but basically when you when + + + align:start position:0% +explanation but basically when you when +you do the calculation proper + + align:start position:0% +you do the calculation proper + + + align:start position:0% +you do the calculation proper +calculation that's what you get you get + + align:start position:0% +calculation that's what you get you get + + + align:start position:0% +calculation that's what you get you get +this for the uh lowest order uh mod now + + align:start position:0% +this for the uh lowest order uh mod now + + + align:start position:0% +this for the uh lowest order uh mod now +the uh the how how does the light look + + align:start position:0% +the uh the how how does the light look + + + align:start position:0% +the uh the how how does the light look +like when it comes out then then + + align:start position:0% +like when it comes out then then + + + align:start position:0% +like when it comes out then then +basically let's go back to the ray + + align:start position:0% +basically let's go back to the ray + + + align:start position:0% +basically let's go back to the ray +picture well the ray picture remember we + + align:start position:0% +picture well the ray picture remember we + + + align:start position:0% +picture well the ray picture remember we +said that the angle has to here be uh + + align:start position:0% +said that the angle has to here be uh + + + align:start position:0% +said that the angle has to here be uh +either equal to the critical or or + + align:start position:0% +either equal to the critical or or + + + align:start position:0% +either equal to the critical or or +bigger and then that then determines the + + align:start position:0% +bigger and then that then determines the + + + align:start position:0% +bigger and then that then determines the +the acceptance angle going in because uh + + align:start position:0% +the acceptance angle going in because uh + + + align:start position:0% +the acceptance angle going in because uh +because rays of light coming in outside + + align:start position:0% +because rays of light coming in outside + + + align:start position:0% +because rays of light coming in outside +this this cone here will be then will + + align:start position:0% +this this cone here will be then will + + + align:start position:0% +this this cone here will be then will +will not undergo total internal + + align:start position:0% +will not undergo total internal + + + align:start position:0% +will not undergo total internal +reflection complete total internal + + align:start position:0% +reflection complete total internal + + + align:start position:0% +reflection complete total internal +reflection and will will be in trouble + + align:start position:0% +reflection and will will be in trouble + + + align:start position:0% +reflection and will will be in trouble +because they won't propagate for too far + + align:start position:0% +because they won't propagate for too far + + + align:start position:0% +because they won't propagate for too far +and they will be attenuated now uh for + + align:start position:0% +and they will be attenuated now uh for + + + align:start position:0% +and they will be attenuated now uh for +the for the light that is within this + + align:start position:0% +the for the light that is within this + + + align:start position:0% +the for the light that is within this +cone here and by the way this cone is + + align:start position:0% +cone here and by the way this cone is + + + align:start position:0% +cone here and by the way this cone is +referred to as a numerical aperture na + + align:start position:0% +referred to as a numerical aperture na + + + align:start position:0% +referred to as a numerical aperture na +for the fiber and na is basically the N + + align:start position:0% +for the fiber and na is basically the N + + + align:start position:0% +for the fiber and na is basically the N +zero the the refractive index of air or + + align:start position:0% +zero the the refractive index of air or + + + align:start position:0% +zero the the refractive index of air or +vacuum outside s uh s uh Theta 0 and and + + align:start position:0% +vacuum outside s uh s uh Theta 0 and and + + + align:start position:0% +vacuum outside s uh s uh Theta 0 and and +and Theta 0 is half this angle here + + align:start position:0% +and Theta 0 is half this angle here + + + align:start position:0% +and Theta 0 is half this angle here +which is determined by then the index + + align:start position:0% +which is determined by then the index + + + align:start position:0% +which is determined by then the index +difference and so on to uh so get us to + + align:start position:0% +difference and so on to uh so get us to + + + align:start position:0% +difference and so on to uh so get us to +the angle here to be bigger than the + + align:start position:0% +the angle here to be bigger than the + + + align:start position:0% +the angle here to be bigger than the +critical angle all right so uh so then + + align:start position:0% +critical angle all right so uh so then + + + align:start position:0% +critical angle all right so uh so then +that then this acceptance angle here The + + align:start position:0% +that then this acceptance angle here The + + + align:start position:0% +that then this acceptance angle here The +Light Within this cone will will + + align:start position:0% +Light Within this cone will will + + + align:start position:0% +Light Within this cone will will +propagate uh and uh in the fiber and + + align:start position:0% +propagate uh and uh in the fiber and + + + align:start position:0% +propagate uh and uh in the fiber and +when it comes out essentially it comes + + align:start position:0% +when it comes out essentially it comes + + + align:start position:0% +when it comes out essentially it comes +out just like this cone here again with + + align:start position:0% +out just like this cone here again with + + + align:start position:0% +out just like this cone here again with +an angle 2 Theta 0 so the light coming + + align:start position:0% +an angle 2 Theta 0 so the light coming + + + align:start position:0% +an angle 2 Theta 0 so the light coming +out from a fiber is uh expands uh pretty + + align:start position:0% +out from a fiber is uh expands uh pretty + + + align:start position:0% +out from a fiber is uh expands uh pretty +fast that's using the ray picture if you + + align:start position:0% +fast that's using the ray picture if you + + + align:start position:0% +fast that's using the ray picture if you +look at the the uh the the true picture + + align:start position:0% +look at the the uh the the true picture + + + align:start position:0% +look at the the uh the the true picture +what happens actually you bring in light + + align:start position:0% +what happens actually you bring in light + + + align:start position:0% +what happens actually you bring in light +that you focus into into the core even + + align:start position:0% +that you focus into into the core even + + + align:start position:0% +that you focus into into the core even +though it spills over the core a little + + align:start position:0% +though it spills over the core a little + + + align:start position:0% +though it spills over the core a little +bit because of the essent wave then will + + align:start position:0% +bit because of the essent wave then will + + + align:start position:0% +bit because of the essent wave then will +propagate down the fiber and then will + + align:start position:0% +propagate down the fiber and then will + + + align:start position:0% +propagate down the fiber and then will +come out on the other side almost like + + align:start position:0% +come out on the other side almost like + + + align:start position:0% +come out on the other side almost like +like it came in so uh and this is very + + align:start position:0% +like it came in so uh and this is very + + + align:start position:0% +like it came in so uh and this is very +close close to the defraction angle + + align:start position:0% +close close to the defraction angle + + + align:start position:0% +close close to the defraction angle +which is of the order of Lambda over D + + align:start position:0% +which is of the order of Lambda over D + + + align:start position:0% +which is of the order of Lambda over D +where D is the size as we discussed way + + align:start position:0% +where D is the size as we discussed way + + + align:start position:0% +where D is the size as we discussed way +early in this uh in this course so even + + align:start position:0% +early in this uh in this course so even + + + align:start position:0% +early in this uh in this course so even +though it propagates as a as a + + align:start position:0% +though it propagates as a as a + + + align:start position:0% +though it propagates as a as a +columnated beam in the fiber but as soon + + align:start position:0% +columnated beam in the fiber but as soon + + + align:start position:0% +columnated beam in the fiber but as soon +as it leaves the fiber it expands uh it + + align:start position:0% +as it leaves the fiber it expands uh it + + + align:start position:0% +as it leaves the fiber it expands uh it +expands very very rapidly all right so + + align:start position:0% +expands very very rapidly all right so + + + align:start position:0% +expands very very rapidly all right so +that's basically then how uh in a simple + + align:start position:0% +that's basically then how uh in a simple + + + align:start position:0% +that's basically then how uh in a simple +way how how light propagates now the + + align:start position:0% +way how how light propagates now the + + + align:start position:0% +way how how light propagates now the +fact that we have low loss where does + + align:start position:0% +fact that we have low loss where does + + + align:start position:0% +fact that we have low loss where does +that come from and and let me show you + + align:start position:0% +that come from and and let me show you + + + align:start position:0% +that come from and and let me show you +some data on on low loss uh uh + + align:start position:0% +some data on on low loss uh uh + + + align:start position:0% +some data on on low loss uh uh +propagation if you if you plot the loss + + align:start position:0% +propagation if you if you plot the loss + + + align:start position:0% +propagation if you if you plot the loss +uh in in propagation as DBS per + + align:start position:0% +uh in in propagation as DBS per + + + align:start position:0% +uh in in propagation as DBS per +kilometer and as a function of + + align:start position:0% +kilometer and as a function of + + + align:start position:0% +kilometer and as a function of +wavelength you find that there is a + + align:start position:0% +wavelength you find that there is a + + + align:start position:0% +wavelength you find that there is a +certain wavelength like 1.55 or 1.3 the + + align:start position:0% +certain wavelength like 1.55 or 1.3 the + + + align:start position:0% +certain wavelength like 1.55 or 1.3 the +loss is is very low it's about let's say + + align:start position:0% +loss is is very low it's about let's say + + + align:start position:0% +loss is is very low it's about let's say +2% or .1% or so per kilometer at at + + align:start position:0% +2% or .1% or so per kilometer at at + + + align:start position:0% +2% or .1% or so per kilometer at at +these uh wavelengths now + + align:start position:0% +these uh wavelengths now + + + align:start position:0% +these uh wavelengths now +0.1% uh 0.1 DB I'm sorry 0.1 DB per + + align:start position:0% +0.1% uh 0.1 DB I'm sorry 0.1 DB per + + + align:start position:0% +0.1% uh 0.1 DB I'm sorry 0.1 DB per +kilometer is like 2% per kilometer loss + + align:start position:0% +kilometer is like 2% per kilometer loss + + + align:start position:0% +kilometer is like 2% per kilometer loss +and that's that's very small that's much + + align:start position:0% +and that's that's very small that's much + + + align:start position:0% +and that's that's very small that's much +smaller than propagating in in wires and + + align:start position:0% +smaller than propagating in in wires and + + + align:start position:0% +smaller than propagating in in wires and +the reason why it's small is first of + + align:start position:0% +the reason why it's small is first of + + + align:start position:0% +the reason why it's small is first of +all is because the the total internal + + align:start position:0% +all is because the the total internal + + + align:start position:0% +all is because the the total internal +reflection is really 100% all right + + align:start position:0% +reflection is really 100% all right + + + align:start position:0% +reflection is really 100% all right +there is there is no loss because of + + align:start position:0% +there is there is no loss because of + + + align:start position:0% +there is there is no loss because of +that and the reason there's any loss at + + align:start position:0% +that and the reason there's any loss at + + + align:start position:0% +that and the reason there's any loss at +all is because you're you're squeezing + + align:start position:0% +all is because you're you're squeezing + + + align:start position:0% +all is because you're you're squeezing +in from one side on this side you have + + align:start position:0% +in from one side on this side you have + + + align:start position:0% +in from one side on this side you have +what we call RA scattering uh the fact + + align:start position:0% +what we call RA scattering uh the fact + + + align:start position:0% +what we call RA scattering uh the fact +that uh I don't want to get into it + + align:start position:0% +that uh I don't want to get into it + + + align:start position:0% +that uh I don't want to get into it +right now but the fact that that you get + + align:start position:0% +right now but the fact that that you get + + + align:start position:0% +right now but the fact that that you get +scaning essentially from uh from the uh + + align:start position:0% +scaning essentially from uh from the uh + + + align:start position:0% +scaning essentially from uh from the uh +fluctuations of density fluctuations + + align:start position:0% +fluctuations of density fluctuations + + + align:start position:0% +fluctuations of density fluctuations +within the glass that's on one side so + + align:start position:0% +within the glass that's on one side so + + + align:start position:0% +within the glass that's on one side so +as the wavelength gets shorter the + + align:start position:0% +as the wavelength gets shorter the + + + align:start position:0% +as the wavelength gets shorter the +scattering gets larger and larger and + + align:start position:0% +scattering gets larger and larger and + + + align:start position:0% +scattering gets larger and larger and +then you're in trouble that's the same + + align:start position:0% +then you're in trouble that's the same + + + align:start position:0% +then you're in trouble that's the same +reason why the sky is blue and so on now + + align:start position:0% +reason why the sky is blue and so on now + + + align:start position:0% +reason why the sky is blue and so on now +on the other side on this side here not + + align:start position:0% +on the other side on this side here not + + + align:start position:0% +on the other side on this side here not +shown is the uh is essentially the + + align:start position:0% +shown is the uh is essentially the + + + align:start position:0% +shown is the uh is essentially the +material uh absorption uh or the + + align:start position:0% +material uh absorption uh or the + + + align:start position:0% +material uh absorption uh or the +infrared absorption and so on for the + + align:start position:0% +infrared absorption and so on for the + + + align:start position:0% +infrared absorption and so on for the +for the let's say for the quartz for the + + align:start position:0% +for the let's say for the quartz for the + + + align:start position:0% +for the let's say for the quartz for the +glass so you're you're boxed in on one + + align:start position:0% +glass so you're you're boxed in on one + + + align:start position:0% +glass so you're you're boxed in on one +side you have R scaning the other side + + align:start position:0% +side you have R scaning the other side + + + align:start position:0% +side you have R scaning the other side +going up is the material absorption and + + align:start position:0% +going up is the material absorption and + + + align:start position:0% +going up is the material absorption and +that's why you have the lowest loss + + align:start position:0% +that's why you have the lowest loss + + + align:start position:0% +that's why you have the lowest loss +around here and that's about the best + + align:start position:0% +around here and that's about the best + + + align:start position:0% +around here and that's about the best +you can do if you want to reduce this + + align:start position:0% +you can do if you want to reduce this + + + align:start position:0% +you can do if you want to reduce this +loss from let's say 0.1 or02 DPS per + + align:start position:0% +loss from let's say 0.1 or02 DPS per + + + align:start position:0% +loss from let's say 0.1 or02 DPS per +kilometer then you have to use other + + align:start position:0% +kilometer then you have to use other + + + align:start position:0% +kilometer then you have to use other +materials and materials whose material + + align:start position:0% +materials and materials whose material + + + align:start position:0% +materials and materials whose material +absorption is further into the infrared + + align:start position:0% +absorption is further into the infrared + + + align:start position:0% +absorption is further into the infrared +so I'm afraid uh uh we're not going to + + align:start position:0% +so I'm afraid uh uh we're not going to + + + align:start position:0% +so I'm afraid uh uh we're not going to +get uh into the visible uh and have low + + align:start position:0% +get uh into the visible uh and have low + + + align:start position:0% +get uh into the visible uh and have low +loss because the uh because of the ra + + align:start position:0% +loss because the uh because of the ra + + + align:start position:0% +loss because the uh because of the ra +scaning so it's going to be if we're + + align:start position:0% +scaning so it's going to be if we're + + + align:start position:0% +scaning so it's going to be if we're +going to go any we're going to do better + + align:start position:0% +going to go any we're going to do better + + + align:start position:0% +going to go any we're going to do better +than this we're going to go further into + + align:start position:0% +than this we're going to go further into + + + align:start position:0% +than this we're going to go further into +into the uh into the infrared which + + align:start position:0% +into the uh into the infrared which + + + align:start position:0% +into the uh into the infrared which +means we have to have the right sources + + align:start position:0% +means we have to have the right sources + + + align:start position:0% +means we have to have the right sources +and and the components and so on to work + + align:start position:0% +and and the components and so on to work + + + align:start position:0% +and and the components and so on to work +in the in the infrared and and the uh + + align:start position:0% +in the in the infrared and and the uh + + + align:start position:0% +in the in the infrared and and the uh +and then deeper in + + align:start position:0% +and then deeper in + + + align:start position:0% +and then deeper in +infrared okay so uh so now we know a + + align:start position:0% +infrared okay so uh so now we know a + + + align:start position:0% +infrared okay so uh so now we know a +little bit about the loss in in the + + align:start position:0% +little bit about the loss in in the + + + align:start position:0% +little bit about the loss in in the +fiber uh and uh basically it's very very + + align:start position:0% +fiber uh and uh basically it's very very + + + align:start position:0% +fiber uh and uh basically it's very very +low loss if if the fiber is is + + align:start position:0% +low loss if if the fiber is is + + + align:start position:0% +low loss if if the fiber is is +constructed very carefully in the sense + + align:start position:0% +constructed very carefully in the sense + + + align:start position:0% +constructed very carefully in the sense +that it's uh it's uh uh synthesized from + + align:start position:0% +that it's uh it's uh uh synthesized from + + + align:start position:0% +that it's uh it's uh uh synthesized from +from Pure materials and not just uh any + + align:start position:0% +from Pure materials and not just uh any + + + align:start position:0% +from Pure materials and not just uh any +old piece of glass that you find + + align:start position:0% +old piece of glass that you find + + + align:start position:0% +old piece of glass that you find +somewhere okay synthesize it from + + align:start position:0% +somewhere okay synthesize it from + + + align:start position:0% +somewhere okay synthesize it from +scratch all right and it's drawn + + align:start position:0% +scratch all right and it's drawn + + + align:start position:0% +scratch all right and it's drawn +together and then you you have this core + + align:start position:0% +together and then you you have this core + + + align:start position:0% +together and then you you have this core +that has slightly higher index than the + + align:start position:0% +that has slightly higher index than the + + + align:start position:0% +that has slightly higher index than the +the clading so you think everything is + + align:start position:0% +the clading so you think everything is + + + align:start position:0% +the clading so you think everything is +fine but there's there's a problem and + + align:start position:0% +fine but there's there's a problem and + + + align:start position:0% +fine but there's there's a problem and +that we want to discuss just like with + + align:start position:0% +that we want to discuss just like with + + + align:start position:0% +that we want to discuss just like with +lasers everybody here wants the the + + align:start position:0% +lasers everybody here wants the the + + + align:start position:0% +lasers everybody here wants the the +lowest order mode which is the single + + align:start position:0% +lowest order mode which is the single + + + align:start position:0% +lowest order mode which is the single +spot that comes out but uh what we find + + align:start position:0% +spot that comes out but uh what we find + + + align:start position:0% +spot that comes out but uh what we find +that there are other uh intensity + + align:start position:0% +that there are other uh intensity + + + align:start position:0% +that there are other uh intensity +distributions that come out and again + + align:start position:0% +distributions that come out and again + + + align:start position:0% +distributions that come out and again +these are called the transverse modes + + align:start position:0% +these are called the transverse modes + + + align:start position:0% +these are called the transverse modes +that can propagate in a fiber satisfying + + align:start position:0% +that can propagate in a fiber satisfying + + + align:start position:0% +that can propagate in a fiber satisfying +Maxell uh equations and so on and the + + align:start position:0% +Maxell uh equations and so on and the + + + align:start position:0% +Maxell uh equations and so on and the +boundary conditions in a in a fiber and + + align:start position:0% +boundary conditions in a in a fiber and + + + align:start position:0% +boundary conditions in a in a fiber and +for and and this is called if a fiber is + + align:start position:0% +for and and this is called if a fiber is + + + align:start position:0% +for and and this is called if a fiber is +then then allows these modes to + + align:start position:0% +then then allows these modes to + + + align:start position:0% +then then allows these modes to +propagate then it's called a multimode + + align:start position:0% +propagate then it's called a multimode + + + align:start position:0% +propagate then it's called a multimode +uh fiber single mode fiber is the fiber + + align:start position:0% +uh fiber single mode fiber is the fiber + + + align:start position:0% +uh fiber single mode fiber is the fiber +that only allows this to go all the + + align:start position:0% +that only allows this to go all the + + + align:start position:0% +that only allows this to go all the +others have high loss and they and they + + align:start position:0% +others have high loss and they and they + + + align:start position:0% +others have high loss and they and they +don't go so now let's let's uh spend a + + align:start position:0% +don't go so now let's let's uh spend a + + + align:start position:0% +don't go so now let's let's uh spend a +couple of minutes on uh on single mode + + align:start position:0% +couple of minutes on uh on single mode + + + align:start position:0% +couple of minutes on uh on single mode +and multi mode fibers before I show you + + align:start position:0% +and multi mode fibers before I show you + + + align:start position:0% +and multi mode fibers before I show you +some + + align:start position:0% +some + + + align:start position:0% +some +demonstrations the uh the in in this + + align:start position:0% +demonstrations the uh the in in this + + + align:start position:0% +demonstrations the uh the in in this +case here I have this is the core and + + align:start position:0% +case here I have this is the core and + + + align:start position:0% +case here I have this is the core and +that's the cladding and the index of the + + align:start position:0% +that's the cladding and the index of the + + + align:start position:0% +that's the cladding and the index of the +core is is N1 Which is higher than the + + align:start position:0% +core is is N1 Which is higher than the + + + align:start position:0% +core is is N1 Which is higher than the +index of the clading which is N2 down + + align:start position:0% +index of the clading which is N2 down + + + align:start position:0% +index of the clading which is N2 down +here now uh the on the x- axis here I'm + + align:start position:0% +here now uh the on the x- axis here I'm + + + align:start position:0% +here now uh the on the x- axis here I'm +plotting what we call the V number + + align:start position:0% +plotting what we call the V number + + + align:start position:0% +plotting what we call the V number +what's the V number right now we're not + + align:start position:0% +what's the V number right now we're not + + + align:start position:0% +what's the V number right now we're not +we don't have time to get into any + + align:start position:0% +we don't have time to get into any + + + align:start position:0% +we don't have time to get into any +detail but the V number is essentially a + + align:start position:0% +detail but the V number is essentially a + + + align:start position:0% +detail but the V number is essentially a +a parameter that depends on on one over + + align:start position:0% +a parameter that depends on on one over + + + align:start position:0% +a parameter that depends on on one over +the wavelength of the light on the D + + align:start position:0% +the wavelength of the light on the D + + + align:start position:0% +the wavelength of the light on the D +subc which is the diameter of the core + + align:start position:0% +subc which is the diameter of the core + + + align:start position:0% +subc which is the diameter of the core +and the square root of N1 squar that's + + align:start position:0% +and the square root of N1 squar that's + + + align:start position:0% +and the square root of N1 squar that's +N1 being the core index and N2 is the + + align:start position:0% +N1 being the core index and N2 is the + + + align:start position:0% +N1 being the core index and N2 is the +cladding index the square root of N1 squ + + align:start position:0% +cladding index the square root of N1 squ + + + align:start position:0% +cladding index the square root of N1 squ +minus N2 squ now turns out when this V + + align:start position:0% +minus N2 squ now turns out when this V + + + align:start position:0% +minus N2 squ now turns out when this V +number has a certain value let's say 2.4 + + align:start position:0% +number has a certain value let's say 2.4 + + + align:start position:0% +number has a certain value let's say 2.4 +or or so on then you only get uh if it's + + align:start position:0% +or or so on then you only get uh if it's + + + align:start position:0% +or or so on then you only get uh if it's +if it's if it's that value or less then + + align:start position:0% +if it's if it's that value or less then + + + align:start position:0% +if it's if it's that value or less then +you only get single mode propagation all + + align:start position:0% +you only get single mode propagation all + + + align:start position:0% +you only get single mode propagation all +the other modes have too much loss and + + align:start position:0% +the other modes have too much loss and + + + align:start position:0% +the other modes have too much loss and +they uh they don't they don't propagate + + align:start position:0% +they uh they don't they don't propagate + + + align:start position:0% +they uh they don't they don't propagate +so single mode fiber then is one where + + align:start position:0% +so single mode fiber then is one where + + + align:start position:0% +so single mode fiber then is one where +the V parameter which means the the size + + align:start position:0% +the V parameter which means the the size + + + align:start position:0% +the V parameter which means the the size +of the core the wavelength and the + + align:start position:0% +of the core the wavelength and the + + + align:start position:0% +of the core the wavelength and the +difference of in the indices are such + + align:start position:0% +difference of in the indices are such + + + align:start position:0% +difference of in the indices are such +that gives you v v parameter smaller + + align:start position:0% +that gives you v v parameter smaller + + + align:start position:0% +that gives you v v parameter smaller +than 2.4 and that's single M if you if + + align:start position:0% +than 2.4 and that's single M if you if + + + align:start position:0% +than 2.4 and that's single M if you if +the let's say you change the wavelength + + align:start position:0% +the let's say you change the wavelength + + + align:start position:0% +the let's say you change the wavelength +you make it shorter or so on V will go + + align:start position:0% +you make it shorter or so on V will go + + + align:start position:0% +you make it shorter or so on V will go +up and then you'll start getting all + + align:start position:0% +up and then you'll start getting all + + + align:start position:0% +up and then you'll start getting all +these uh uh uh multim modes or the just + + align:start position:0% +these uh uh uh multim modes or the just + + + align:start position:0% +these uh uh uh multim modes or the just +like I showed you I showed you before + + align:start position:0% +like I showed you I showed you before + + + align:start position:0% +like I showed you I showed you before +and uh and uh and then you'll be in + + align:start position:0% +and uh and uh and then you'll be in + + + align:start position:0% +and uh and uh and then you'll be in +trouble so for some application not all + + align:start position:0% +trouble so for some application not all + + + align:start position:0% +trouble so for some application not all +applications the uh in this particular + + align:start position:0% +applications the uh in this particular + + + align:start position:0% +applications the uh in this particular +case what I show you is the field + + align:start position:0% +case what I show you is the field + + + align:start position:0% +case what I show you is the field +distribution and the intensity + + align:start position:0% +distribution and the intensity + + + align:start position:0% +distribution and the intensity +distribution uh uh in the in the fiber + + align:start position:0% +distribution uh uh in the in the fiber + + + align:start position:0% +distribution uh uh in the in the fiber +here's the core is the size of the core + + align:start position:0% +here's the core is the size of the core + + + align:start position:0% +here's the core is the size of the core +and that's the clading and you can see + + align:start position:0% +and that's the clading and you can see + + + align:start position:0% +and that's the clading and you can see +here depending on on the parameters that + + align:start position:0% +here depending on on the parameters that + + + align:start position:0% +here depending on on the parameters that +I choose + + align:start position:0% +I choose + + + align:start position:0% +I choose +some light uh in in this lowest auto + + align:start position:0% +some light uh in in this lowest auto + + + align:start position:0% +some light uh in in this lowest auto +mode in the field will will propagate in + + align:start position:0% +mode in the field will will propagate in + + + align:start position:0% +mode in the field will will propagate in +the in the cladding and so with the + + align:start position:0% +the in the cladding and so with the + + + align:start position:0% +the in the cladding and so with the +essentially intensity for the next high + + align:start position:0% +essentially intensity for the next high + + + align:start position:0% +essentially intensity for the next high +order mode okay which is similar to the + + align:start position:0% +order mode okay which is similar to the + + + align:start position:0% +order mode okay which is similar to the +laser cavity modes the field + + align:start position:0% +laser cavity modes the field + + + align:start position:0% +laser cavity modes the field +distribution is something like this and + + align:start position:0% +distribution is something like this and + + + align:start position:0% +distribution is something like this and +again part of it will will propagate + + align:start position:0% +again part of it will will propagate + + + align:start position:0% +again part of it will will propagate +into into uh in the cladding and when + + align:start position:0% +into into uh in the cladding and when + + + align:start position:0% +into into uh in the cladding and when +you square it up if you look at the + + align:start position:0% +you square it up if you look at the + + + align:start position:0% +you square it up if you look at the +intensity it looks like this that's what + + align:start position:0% +intensity it looks like this that's what + + + align:start position:0% +intensity it looks like this that's what +the two spots look like that but the + + align:start position:0% +the two spots look like that but the + + + align:start position:0% +the two spots look like that but the +field is really one is let's say + + align:start position:0% +field is really one is let's say + + + align:start position:0% +field is really one is let's say +positive the other one is is negative + + align:start position:0% +positive the other one is is negative + + + align:start position:0% +positive the other one is is negative +and what you see here is that the the uh + + align:start position:0% +and what you see here is that the the uh + + + align:start position:0% +and what you see here is that the the uh +size of the uh of this uh higher aut + + align:start position:0% +size of the uh of this uh higher aut + + + align:start position:0% +size of the uh of this uh higher aut +mode is bigger than the lowest aut mode + + align:start position:0% +mode is bigger than the lowest aut mode + + + align:start position:0% +mode is bigger than the lowest aut mode +and more of it will propagate in the + + align:start position:0% +and more of it will propagate in the + + + align:start position:0% +and more of it will propagate in the +cladding than in the core so in terms of + + align:start position:0% +cladding than in the core so in terms of + + + align:start position:0% +cladding than in the core so in terms of +propagation constant or how fast they + + align:start position:0% +propagation constant or how fast they + + + align:start position:0% +propagation constant or how fast they +propagate uh this one propagates more in + + align:start position:0% +propagate uh this one propagates more in + + + align:start position:0% +propagate uh this one propagates more in +the in the in the cladding than this one + + align:start position:0% +the in the in the cladding than this one + + + align:start position:0% +the in the in the cladding than this one +and since the index is smaller in the + + align:start position:0% +and since the index is smaller in the + + + align:start position:0% +and since the index is smaller in the +cladding than in the core then this one + + align:start position:0% +cladding than in the core then this one + + + align:start position:0% +cladding than in the core then this one +will go faster than this one and that's + + align:start position:0% +will go faster than this one and that's + + + align:start position:0% +will go faster than this one and that's +a problem in in Communications in using + + align:start position:0% +a problem in in Communications in using + + + align:start position:0% +a problem in in Communications in using +uh transverse modes in this in this next + + align:start position:0% +uh transverse modes in this in this next + + + align:start position:0% +uh transverse modes in this in this next +uh uh uh graphic I show how much again + + align:start position:0% +uh uh uh graphic I show how much again + + + align:start position:0% +uh uh uh graphic I show how much again +as a function of v number but how much + + align:start position:0% +as a function of v number but how much + + + align:start position:0% +as a function of v number but how much +of the light propagates in the core and + + align:start position:0% +of the light propagates in the core and + + + align:start position:0% +of the light propagates in the core and +how much propagates in the cladding so + + align:start position:0% +how much propagates in the cladding so + + + align:start position:0% +how much propagates in the cladding so +again for V number below this 2.4 or so + + align:start position:0% +again for V number below this 2.4 or so + + + align:start position:0% +again for V number below this 2.4 or so +the for single mode operation it turns + + align:start position:0% +the for single mode operation it turns + + + align:start position:0% +the for single mode operation it turns +out that when the V number is very very + + align:start position:0% +out that when the V number is very very + + + align:start position:0% +out that when the V number is very very +small most of the light I'm plotting + + align:start position:0% +small most of the light I'm plotting + + + align:start position:0% +small most of the light I'm plotting +here uh Power in the core transmitting + + align:start position:0% +here uh Power in the core transmitting + + + align:start position:0% +here uh Power in the core transmitting +the core over the total power + + align:start position:0% +the core over the total power + + + align:start position:0% +the core over the total power +propagated through the fiber then it + + align:start position:0% +propagated through the fiber then it + + + align:start position:0% +propagated through the fiber then it +turns out when the V number is very + + align:start position:0% +turns out when the V number is very + + + align:start position:0% +turns out when the V number is very +small even the single mode propagates + + align:start position:0% +small even the single mode propagates + + + align:start position:0% +small even the single mode propagates +more in the in the cladding than the + + align:start position:0% +more in the in the cladding than the + + + align:start position:0% +more in the in the cladding than the +core okay because uh the ratio of P core + + align:start position:0% +core okay because uh the ratio of P core + + + align:start position:0% +core okay because uh the ratio of P core +to P is very small and as I approach uh + + align:start position:0% +to P is very small and as I approach uh + + + align:start position:0% +to P is very small and as I approach uh +the uh multi mode operation the the + + align:start position:0% +the uh multi mode operation the the + + + align:start position:0% +the uh multi mode operation the the +single mode travels let's say about uh + + align:start position:0% +single mode travels let's say about uh + + + align:start position:0% +single mode travels let's say about uh +80% or so in the core but not in the + + align:start position:0% +80% or so in the core but not in the + + + align:start position:0% +80% or so in the core but not in the +clading now when the multi when the + + align:start position:0% +clading now when the multi when the + + + align:start position:0% +clading now when the multi when the +onset of multim modes comes about then + + align:start position:0% +onset of multim modes comes about then + + + align:start position:0% +onset of multim modes comes about then +the multim mode will at mostly in the in + + align:start position:0% +the multim mode will at mostly in the in + + + align:start position:0% +the multim mode will at mostly in the in +the clading first more in the clading + + align:start position:0% +the clading first more in the clading + + + align:start position:0% +the clading first more in the clading +than in the core and then as I increase + + align:start position:0% +than in the core and then as I increase + + + align:start position:0% +than in the core and then as I increase +the V number they again will start + + align:start position:0% +the V number they again will start + + + align:start position:0% +the V number they again will start +coming in to the propagating in the core + + align:start position:0% +coming in to the propagating in the core + + + align:start position:0% +coming in to the propagating in the core +and and their index th to approach the + + align:start position:0% +and and their index th to approach the + + + align:start position:0% +and and their index th to approach the +index of the single mode but in always + + align:start position:0% +index of the single mode but in always + + + align:start position:0% +index of the single mode but in always +it's lower than that of the of the + + align:start position:0% +it's lower than that of the of the + + + align:start position:0% +it's lower than that of the of the +single mode okay so they all travel + + align:start position:0% +single mode okay so they all travel + + + align:start position:0% +single mode okay so they all travel +essentially at at different speeds and + + align:start position:0% +essentially at at different speeds and + + + align:start position:0% +essentially at at different speeds and +also the transverse modes occupy they + + align:start position:0% +also the transverse modes occupy they + + + align:start position:0% +also the transverse modes occupy they +travel more in the in the uh in the uh + + align:start position:0% +travel more in the in the uh in the uh + + + align:start position:0% +travel more in the in the uh in the uh +uh cladding than in the than in the than + + align:start position:0% +uh cladding than in the than in the than + + + align:start position:0% +uh cladding than in the than in the than +the core as compared with the with a + + align:start position:0% +the core as compared with the with a + + + align:start position:0% +the core as compared with the with a +single mode now to give you to give you + + align:start position:0% +single mode now to give you to give you + + + align:start position:0% +single mode now to give you to give you +an an + + align:start position:0% +an an + + + align:start position:0% +an an +example uh for single mode fiber uh + + align:start position:0% +example uh for single mode fiber uh + + + align:start position:0% +example uh for single mode fiber uh +let's say for a diameter core diameter + + align:start position:0% +let's say for a diameter core diameter + + + align:start position:0% +let's say for a diameter core diameter +of 5 microns and a wavelength of 08 + + align:start position:0% +of 5 microns and a wavelength of 08 + + + align:start position:0% +of 5 microns and a wavelength of 08 +microns uh you need the you need N1 + + align:start position:0% +microns uh you need the you need N1 + + + align:start position:0% +microns uh you need the you need N1 +minus N2 the difference in the index to + + align:start position:0% +minus N2 the difference in the index to + + + align:start position:0% +minus N2 the difference in the index to +be 10 Theus 3 now if you want to make uh + + align:start position:0% +be 10 Theus 3 now if you want to make uh + + + align:start position:0% +be 10 Theus 3 now if you want to make uh +the core diameter uh larger then you're + + align:start position:0% +the core diameter uh larger then you're + + + align:start position:0% +the core diameter uh larger then you're +going to end up with N1 minus N2 even + + align:start position:0% +going to end up with N1 minus N2 even + + + align:start position:0% +going to end up with N1 minus N2 even +smaller so it's very tricky to make uh + + align:start position:0% +smaller so it's very tricky to make uh + + + align:start position:0% +smaller so it's very tricky to make uh +uh single mode fibers otherwise you have + + align:start position:0% +uh single mode fibers otherwise you have + + + align:start position:0% +uh single mode fibers otherwise you have +multi mode operation all right so now + + align:start position:0% +multi mode operation all right so now + + + align:start position:0% +multi mode operation all right so now +that I have talked about about single + + align:start position:0% +that I have talked about about single + + + align:start position:0% +that I have talked about about single +mode and and uh and uh multimode fibers + + align:start position:0% +mode and and uh and uh multimode fibers + + + align:start position:0% +mode and and uh and uh multimode fibers +I have uh two demonstrations for you one + + align:start position:0% +I have uh two demonstrations for you one + + + align:start position:0% +I have uh two demonstrations for you one +basically shows single mode fiber and + + align:start position:0% +basically shows single mode fiber and + + + align:start position:0% +basically shows single mode fiber and +coupling into it and what the output + + align:start position:0% +coupling into it and what the output + + + align:start position:0% +coupling into it and what the output +looks like and also is bend the fiber + + align:start position:0% +looks like and also is bend the fiber + + + align:start position:0% +looks like and also is bend the fiber +and show that whatever you do is still + + align:start position:0% +and show that whatever you do is still + + + align:start position:0% +and show that whatever you do is still +single mode it doesn't change on you all + + align:start position:0% +single mode it doesn't change on you all + + + align:start position:0% +single mode it doesn't change on you all +happens is that you kick light out and + + align:start position:0% +happens is that you kick light out and + + + align:start position:0% +happens is that you kick light out and +and you reduce the intensity but when we + + align:start position:0% +and you reduce the intensity but when we + + + align:start position:0% +and you reduce the intensity but when we +came to multimode something else happens + + align:start position:0% +came to multimode something else happens + + + align:start position:0% +came to multimode something else happens +so now first let's go to the single mode + + align:start position:0% +so now first let's go to the single mode + + + align:start position:0% +so now first let's go to the single mode +uh fiber + + align:start position:0% + + + + align:start position:0% + +demonstration in this demonstration + + align:start position:0% +demonstration in this demonstration + + + align:start position:0% +demonstration in this demonstration +we're going to illustrate the + + align:start position:0% +we're going to illustrate the + + + align:start position:0% +we're going to illustrate the +propagation of light in a fiber a glass + + align:start position:0% +propagation of light in a fiber a glass + + + align:start position:0% +propagation of light in a fiber a glass +fiber as we know today Optical fibers + + align:start position:0% +fiber as we know today Optical fibers + + + align:start position:0% +fiber as we know today Optical fibers +have a lot of low loss very low loss of + + align:start position:0% +have a lot of low loss very low loss of + + + align:start position:0% +have a lot of low loss very low loss of +the order of uh one or two DBS per + + align:start position:0% +the order of uh one or two DBS per + + + align:start position:0% +the order of uh one or two DBS per +kilometer and of course they're being + + align:start position:0% +kilometer and of course they're being + + + align:start position:0% +kilometer and of course they're being +used for communication as well as other + + align:start position:0% +used for communication as well as other + + + align:start position:0% +used for communication as well as other +applications like + + align:start position:0% +applications like + + + align:start position:0% +applications like +sensors so the setup we have is a uh is + + align:start position:0% +sensors so the setup we have is a uh is + + + align:start position:0% +sensors so the setup we have is a uh is +a laser a helium neon laser over here + + align:start position:0% +a laser a helium neon laser over here + + + align:start position:0% +a laser a helium neon laser over here +here's the output from from the laser + + align:start position:0% +here's the output from from the laser + + + align:start position:0% +here's the output from from the laser +we're going to reflect it by this mirror + + align:start position:0% +we're going to reflect it by this mirror + + + align:start position:0% +we're going to reflect it by this mirror +in this + + align:start position:0% +in this + + + align:start position:0% +in this +mirror and then pass it through a lens + + align:start position:0% +mirror and then pass it through a lens + + + align:start position:0% +mirror and then pass it through a lens +this lens over here here focuses the + + align:start position:0% +this lens over here here focuses the + + + align:start position:0% +this lens over here here focuses the +light into the fiber end and if we can + + align:start position:0% +light into the fiber end and if we can + + + align:start position:0% +light into the fiber end and if we can +take a + + align:start position:0% +take a + + + align:start position:0% +take a +closeup of what's going on over here + + align:start position:0% +closeup of what's going on over here + + + align:start position:0% +closeup of what's going on over here +what you would see is then a lens this + + align:start position:0% +what you would see is then a lens this + + + align:start position:0% +what you would see is then a lens this +lens then focusing the light and fiber + + align:start position:0% +lens then focusing the light and fiber + + + align:start position:0% +lens then focusing the light and fiber +and the fiber is very close to the + + align:start position:0% +and the fiber is very close to the + + + align:start position:0% +and the fiber is very close to the +lens and then the rest of the fiber is + + align:start position:0% +lens and then the rest of the fiber is + + + align:start position:0% +lens and then the rest of the fiber is +here all right so here is the the rest + + align:start position:0% +here all right so here is the the rest + + + align:start position:0% +here all right so here is the the rest +of the fiber now this fiber uh in fact + + align:start position:0% +of the fiber now this fiber uh in fact + + + align:start position:0% +of the fiber now this fiber uh in fact +what you're seeing over here is the uh + + align:start position:0% +what you're seeing over here is the uh + + + align:start position:0% +what you're seeing over here is the uh +essentially the plastic jacket the fiber + + align:start position:0% +essentially the plastic jacket the fiber + + + align:start position:0% +essentially the plastic jacket the fiber +core is about four microns in in + + align:start position:0% +core is about four microns in in + + + align:start position:0% +core is about four microns in in +diameter and the cladding is 125 microns + + align:start position:0% +diameter and the cladding is 125 microns + + + align:start position:0% +diameter and the cladding is 125 microns +and the rest that you see here is the is + + align:start position:0% +and the rest that you see here is the is + + + align:start position:0% +and the rest that you see here is the is +the plastic jacket that's why it looks + + align:start position:0% +the plastic jacket that's why it looks + + + align:start position:0% +the plastic jacket that's why it looks +so so visible uh because it's so thick + + align:start position:0% +so so visible uh because it's so thick + + + align:start position:0% +so so visible uh because it's so thick +the other end of the fiber then uh goes + + align:start position:0% +the other end of the fiber then uh goes + + + align:start position:0% +the other end of the fiber then uh goes +into this + + align:start position:0% +into this + + + align:start position:0% +into this +holder and the the Chuck here it's in AO + + align:start position:0% +holder and the the Chuck here it's in AO + + + align:start position:0% +holder and the the Chuck here it's in AO +fiber hold in a Chuck and the output of + + align:start position:0% +fiber hold in a Chuck and the output of + + + align:start position:0% +fiber hold in a Chuck and the output of +the of the fiber then is is over here + + align:start position:0% +the of the fiber then is is over here + + + align:start position:0% +the of the fiber then is is over here +onto this uh onto this little + + align:start position:0% +onto this uh onto this little + + + align:start position:0% +onto this uh onto this little +screen now if if we can maybe we can + + align:start position:0% +screen now if if we can maybe we can + + + align:start position:0% +screen now if if we can maybe we can +take a close look at the at the fiber + + align:start position:0% +take a close look at the at the fiber + + + align:start position:0% +take a close look at the at the fiber +end + + align:start position:0% +end + + + align:start position:0% +end +here what which + + align:start position:0% +here what which + + + align:start position:0% +here what which +shows that uh what you see over here uh + + align:start position:0% +shows that uh what you see over here uh + + + align:start position:0% +shows that uh what you see over here uh +in fact let me point to it what you see + + align:start position:0% +in fact let me point to it what you see + + + align:start position:0% +in fact let me point to it what you see +over here is the the cladding + + align:start position:0% +over here is the the cladding + + + align:start position:0% +over here is the the cladding +essentially we've stripped the jacket + + align:start position:0% +essentially we've stripped the jacket + + + align:start position:0% +essentially we've stripped the jacket +and what you see here is just the + + align:start position:0% +and what you see here is just the + + + align:start position:0% +and what you see here is just the +cladding and this is the 125 micron + + align:start position:0% +cladding and this is the 125 micron + + + align:start position:0% +cladding and this is the 125 micron +while over here over + + align:start position:0% +while over here over + + + align:start position:0% +while over here over +here is the is the the fiber with the + + align:start position:0% +here is the is the the fiber with the + + + align:start position:0% +here is the is the the fiber with the +plastic with the plastic jacket so when + + align:start position:0% +plastic with the plastic jacket so when + + + align:start position:0% +plastic with the plastic jacket so when +you remove the plastic jacket then you + + align:start position:0% +you remove the plastic jacket then you + + + align:start position:0% +you remove the plastic jacket then you +have essentially what you're seeing is + + align:start position:0% +have essentially what you're seeing is + + + align:start position:0% +have essentially what you're seeing is +the is just the 125 Micron cladding all + + align:start position:0% +the is just the 125 Micron cladding all + + + align:start position:0% +the is just the 125 Micron cladding all +right so this is then uh the fiber and + + align:start position:0% +right so this is then uh the fiber and + + + align:start position:0% +right so this is then uh the fiber and +there's the output of the of the fiber + + align:start position:0% +there's the output of the of the fiber + + + align:start position:0% +there's the output of the of the fiber +now what we see if we can then enhance + + align:start position:0% +now what we see if we can then enhance + + + align:start position:0% +now what we see if we can then enhance +this and bring it bring it in what we + + align:start position:0% +this and bring it bring it in what we + + + align:start position:0% +this and bring it bring it in what we +see is the uh is the single mode uh + + align:start position:0% +see is the uh is the single mode uh + + + align:start position:0% +see is the uh is the single mode uh +behavior of of a + + align:start position:0% +behavior of of a + + + align:start position:0% +behavior of of a +fiber it looks like almost like a + + align:start position:0% +fiber it looks like almost like a + + + align:start position:0% +fiber it looks like almost like a +gaussian kind of + + align:start position:0% +gaussian kind of + + + align:start position:0% +gaussian kind of +spot not quite gaussian but it looks + + align:start position:0% +spot not quite gaussian but it looks + + + align:start position:0% +spot not quite gaussian but it looks +like a gaussian kind of spot now what + + align:start position:0% +like a gaussian kind of spot now what + + + align:start position:0% +like a gaussian kind of spot now what +I'm doing + + align:start position:0% +I'm doing + + + align:start position:0% +I'm doing +now uh is just it just adjusting the the + + align:start position:0% +now uh is just it just adjusting the the + + + align:start position:0% +now uh is just it just adjusting the the +uh coupling into into the fiber and it's + + align:start position:0% +uh coupling into into the fiber and it's + + + align:start position:0% +uh coupling into into the fiber and it's +very touchy because as said the core is + + align:start position:0% +very touchy because as said the core is + + + align:start position:0% +very touchy because as said the core is +only about four four + + align:start position:0% +only about four four + + + align:start position:0% +only about four four +microns all right so this is what then a + + align:start position:0% +microns all right so this is what then a + + + align:start position:0% +microns all right so this is what then a +single mode uh uh fiber the output from + + align:start position:0% +single mode uh uh fiber the output from + + + align:start position:0% +single mode uh uh fiber the output from +a single mode fiber looks like and if as + + align:start position:0% +a single mode fiber looks like and if as + + + align:start position:0% +a single mode fiber looks like and if as +I miss a line here doesn't make any + + align:start position:0% +I miss a line here doesn't make any + + + align:start position:0% +I miss a line here doesn't make any +difference all you get is just a loss in + + align:start position:0% +difference all you get is just a loss in + + + align:start position:0% +difference all you get is just a loss in +intensity the shape of the mode stays + + align:start position:0% +intensity the shape of the mode stays + + + align:start position:0% +intensity the shape of the mode stays +stays the same so remember the core is + + align:start position:0% +stays the same so remember the core is + + + align:start position:0% +stays the same so remember the core is +four microns cladding is 125 the + + align:start position:0% +four microns cladding is 125 the + + + align:start position:0% +four microns cladding is 125 the +wavelength of the light is 6328 anrom + + align:start position:0% +wavelength of the light is 6328 anrom + + + align:start position:0% +wavelength of the light is 6328 anrom +and the core to index uh difference is + + align:start position:0% +and the core to index uh difference is + + + align:start position:0% +and the core to index uh difference is +about one part in in 10 to the three so + + align:start position:0% +about one part in in 10 to the three so + + + align:start position:0% +about one part in in 10 to the three so +this way you can show that indeed you + + align:start position:0% +this way you can show that indeed you + + + align:start position:0% +this way you can show that indeed you +get uh single mode + + align:start position:0% +get uh single mode + + + align:start position:0% +get uh single mode +propagation now I would like to + + align:start position:0% +propagation now I would like to + + + align:start position:0% +propagation now I would like to +illustrate some interesting phenomena + + align:start position:0% +illustrate some interesting phenomena + + + align:start position:0% +illustrate some interesting phenomena +about fibers so if we get the camera to + + align:start position:0% +about fibers so if we get the camera to + + + align:start position:0% +about fibers so if we get the camera to +look over + + align:start position:0% +look over + + + align:start position:0% +look over +here I want to illustrate how touchy uh + + align:start position:0% +here I want to illustrate how touchy uh + + + align:start position:0% +here I want to illustrate how touchy uh +uh is the propagation of light in a in a + + align:start position:0% +uh is the propagation of light in a in a + + + align:start position:0% +uh is the propagation of light in a in a +single mode fiber now here is here's a + + align:start position:0% +single mode fiber now here is here's a + + + align:start position:0% +single mode fiber now here is here's a +piece of fiber and you can see that + + align:start position:0% +piece of fiber and you can see that + + + align:start position:0% +piece of fiber and you can see that +there's no light uh scattered from the + + align:start position:0% +there's no light uh scattered from the + + + align:start position:0% +there's no light uh scattered from the +fiber + + align:start position:0% + + + + align:start position:0% + +now all I have to do is bend the fiber + + align:start position:0% +now all I have to do is bend the fiber + + + align:start position:0% +now all I have to do is bend the fiber +bend the F and you're beginning to see + + align:start position:0% +bend the F and you're beginning to see + + + align:start position:0% +bend the F and you're beginning to see +light that gets gets transmitted out of + + align:start position:0% +light that gets gets transmitted out of + + + align:start position:0% +light that gets gets transmitted out of +the fiber gets essentially kicked out + + align:start position:0% +the fiber gets essentially kicked out + + + align:start position:0% +the fiber gets essentially kicked out +the fiber and uh because because of the + + align:start position:0% +the fiber and uh because because of the + + + align:start position:0% +the fiber and uh because because of the +bend now and and and the reason for that + + align:start position:0% +bend now and and and the reason for that + + + align:start position:0% +bend now and and and the reason for that +because it's you start uh going against + + align:start position:0% +because it's you start uh going against + + + align:start position:0% +because it's you start uh going against +the rules of uh propagation of light in + + align:start position:0% +the rules of uh propagation of light in + + + align:start position:0% +the rules of uh propagation of light in +a fiber + + align:start position:0% +a fiber + + + align:start position:0% +a fiber +for example if you take the ray uh + + align:start position:0% +for example if you take the ray uh + + + align:start position:0% +for example if you take the ray uh +explanation is that what you're doing + + align:start position:0% +explanation is that what you're doing + + + align:start position:0% +explanation is that what you're doing +you are exceeding or or you're changing + + align:start position:0% +you are exceeding or or you're changing + + + align:start position:0% +you are exceeding or or you're changing +the angle of + + align:start position:0% +the angle of + + + align:start position:0% +the angle of +light uh with respect to the to the to + + align:start position:0% +light uh with respect to the to the to + + + align:start position:0% +light uh with respect to the to the to +the uh to the fiber which means that if + + align:start position:0% +the uh to the fiber which means that if + + + align:start position:0% +the uh to the fiber which means that if +you're if you're below the critical + + align:start position:0% +you're if you're below the critical + + + align:start position:0% +you're if you're below the critical +angle then you uh the light is no longer + + align:start position:0% +angle then you uh the light is no longer + + + align:start position:0% +angle then you uh the light is no longer +totally internally reflected and + + align:start position:0% +totally internally reflected and + + + align:start position:0% +totally internally reflected and +therefore gets kicked out all right so + + align:start position:0% +therefore gets kicked out all right so + + + align:start position:0% +therefore gets kicked out all right so +here it is it's very dramatic as soon as + + align:start position:0% +here it is it's very dramatic as soon as + + + align:start position:0% +here it is it's very dramatic as soon as +you put Little Bend in this fiber you + + align:start position:0% +you put Little Bend in this fiber you + + + align:start position:0% +you put Little Bend in this fiber you +can you can kick out a lot of light in + + align:start position:0% +can you can kick out a lot of light in + + + align:start position:0% +can you can kick out a lot of light in +fact there is the glow uh right here now + + align:start position:0% +fact there is the glow uh right here now + + + align:start position:0% +fact there is the glow uh right here now +if we can bring in the the output of the + + align:start position:0% +if we can bring in the the output of the + + + align:start position:0% +if we can bring in the the output of the +fiber into the inset over here now you + + align:start position:0% +fiber into the inset over here now you + + + align:start position:0% +fiber into the inset over here now you +can see that as I increase the the band + + align:start position:0% +can see that as I increase the the band + + + align:start position:0% +can see that as I increase the the band +all right you can see that the intensity + + align:start position:0% +all right you can see that the intensity + + + align:start position:0% +all right you can see that the intensity +here I'll do it even more the intensity + + align:start position:0% +here I'll do it even more the intensity + + + align:start position:0% +here I'll do it even more the intensity +then drops quite a bit which means I've + + align:start position:0% +then drops quite a bit which means I've + + + align:start position:0% +then drops quite a bit which means I've +kicked out almost all all the light by + + align:start position:0% +kicked out almost all all the light by + + + align:start position:0% +kicked out almost all all the light by +simply putting a Bend into into the + + align:start position:0% +simply putting a Bend into into the + + + align:start position:0% +simply putting a Bend into into the +fiber so the the illustration here then + + align:start position:0% +fiber so the the illustration here then + + + align:start position:0% +fiber so the the illustration here then +shows that if you leave the fiber alone + + align:start position:0% +shows that if you leave the fiber alone + + + align:start position:0% +shows that if you leave the fiber alone +without sharp bends everything is fine + + align:start position:0% +without sharp bends everything is fine + + + align:start position:0% +without sharp bends everything is fine +if you put in a band then you can kick + + align:start position:0% +if you put in a band then you can kick + + + align:start position:0% +if you put in a band then you can kick +out a lot of light and then not much + + align:start position:0% +out a lot of light and then not much + + + align:start position:0% +out a lot of light and then not much +will be will be will be + + align:start position:0% +will be will be will be + + + align:start position:0% +will be will be will be +transmitted so you have to be careful + + align:start position:0% +transmitted so you have to be careful + + + align:start position:0% +transmitted so you have to be careful +you don't put it too tight a Bend + + align:start position:0% +you don't put it too tight a Bend + + + align:start position:0% +you don't put it too tight a Bend +otherwise you fiber is brittle and you + + align:start position:0% +otherwise you fiber is brittle and you + + + align:start position:0% +otherwise you fiber is brittle and you +break the fiber so you have to be be + + align:start position:0% +break the fiber so you have to be be + + + align:start position:0% +break the fiber so you have to be be +careful how you how you do + + align:start position:0% +careful how you how you do + + + align:start position:0% +careful how you how you do +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +this in this previous demonstration then + + align:start position:0% +this in this previous demonstration then + + + align:start position:0% +this in this previous demonstration then +what we had was a single mode single + + align:start position:0% +what we had was a single mode single + + + align:start position:0% +what we had was a single mode single +mode fiber which means that it's a fiber + + align:start position:0% +mode fiber which means that it's a fiber + + + align:start position:0% +mode fiber which means that it's a fiber +that satisfied this V number being uh + + align:start position:0% +that satisfied this V number being uh + + + align:start position:0% +that satisfied this V number being uh +less than 2.4 or + + align:start position:0% +less than 2.4 or + + + align:start position:0% +less than 2.4 or +so and uh and uh because of again the + + align:start position:0% +so and uh and uh because of again the + + + align:start position:0% +so and uh and uh because of again the +choice of the cord diameter the + + align:start position:0% +choice of the cord diameter the + + + align:start position:0% +choice of the cord diameter the +wavelength and the difference in the in + + align:start position:0% +wavelength and the difference in the in + + + align:start position:0% +wavelength and the difference in the in +the in the indices now in this next + + align:start position:0% +the in the indices now in this next + + + align:start position:0% +the in the indices now in this next +demonstration we're going to uh violate + + align:start position:0% +demonstration we're going to uh violate + + + align:start position:0% +demonstration we're going to uh violate +this we're going to uh create a v that + + align:start position:0% +this we're going to uh create a v that + + + align:start position:0% +this we're going to uh create a v that +is bigger than uh than this value here + + align:start position:0% +is bigger than uh than this value here + + + align:start position:0% +is bigger than uh than this value here +by uh in our case we did it by have + + align:start position:0% +by uh in our case we did it by have + + + align:start position:0% +by uh in our case we did it by have +choosing a fiber that has a that's a + + align:start position:0% +choosing a fiber that has a that's a + + + align:start position:0% +choosing a fiber that has a that's a +bigger cord diameter but we could have + + align:start position:0% +bigger cord diameter but we could have + + + align:start position:0% +bigger cord diameter but we could have +also done it with by changing the + + align:start position:0% +also done it with by changing the + + + align:start position:0% +also done it with by changing the +wavelength and if you just shorten the + + align:start position:0% +wavelength and if you just shorten the + + + align:start position:0% +wavelength and if you just shorten the +wavelength go more into into the uh into + + align:start position:0% +wavelength go more into into the uh into + + + align:start position:0% +wavelength go more into into the uh into +the blue side of the spectrum then you + + align:start position:0% +the blue side of the spectrum then you + + + align:start position:0% +the blue side of the spectrum then you +can uh you start to see uh transverse + + align:start position:0% +can uh you start to see uh transverse + + + align:start position:0% +can uh you start to see uh transverse +modes like I uh I showed you uh I showed + + align:start position:0% +modes like I uh I showed you uh I showed + + + align:start position:0% +modes like I uh I showed you uh I showed +you before okay and I think now + + align:start position:0% +you before okay and I think now + + + align:start position:0% +you before okay and I think now +uh we're ready to uh have fun with a + + align:start position:0% +uh we're ready to uh have fun with a + + + align:start position:0% +uh we're ready to uh have fun with a +multimode + + align:start position:0% + + + + align:start position:0% + +fiber now we've replaced the previous + + align:start position:0% +fiber now we've replaced the previous + + + align:start position:0% +fiber now we've replaced the previous +fiber with another one the only + + align:start position:0% +fiber with another one the only + + + align:start position:0% +fiber with another one the only +difference between this fiber and the + + align:start position:0% +difference between this fiber and the + + + align:start position:0% +difference between this fiber and the +previous one is that the core diameter + + align:start position:0% +previous one is that the core diameter + + + align:start position:0% +previous one is that the core diameter +is now a little bit bigger it's about + + align:start position:0% +is now a little bit bigger it's about + + + align:start position:0% +is now a little bit bigger it's about +six microns instead of four microns in + + align:start position:0% +six microns instead of four microns in + + + align:start position:0% +six microns instead of four microns in +the previous finer setup is exactly the + + align:start position:0% +the previous finer setup is exactly the + + + align:start position:0% +the previous finer setup is exactly the +same again we have the laser here + + align:start position:0% +same again we have the laser here + + + align:start position:0% +same again we have the laser here +getting reflected by this mirror and + + align:start position:0% +getting reflected by this mirror and + + + align:start position:0% +getting reflected by this mirror and +this mirror into the lens into this + + align:start position:0% +this mirror into the lens into this + + + align:start position:0% +this mirror into the lens into this +fiber this new fiber and then the the + + align:start position:0% +fiber this new fiber and then the the + + + align:start position:0% +fiber this new fiber and then the the +output of the Fiber goes onto the screen + + align:start position:0% +output of the Fiber goes onto the screen + + + align:start position:0% +output of the Fiber goes onto the screen +so let's now take a look at the output + + align:start position:0% +so let's now take a look at the output + + + align:start position:0% +so let's now take a look at the output +of this + + align:start position:0% +of this + + + align:start position:0% +of this +fi uhhuh so what first thing we see that + + align:start position:0% +fi uhhuh so what first thing we see that + + + align:start position:0% +fi uhhuh so what first thing we see that +doesn't look like a single mode at all + + align:start position:0% +doesn't look like a single mode at all + + + align:start position:0% +doesn't look like a single mode at all +that single low and if I change the the + + align:start position:0% +that single low and if I change the the + + + align:start position:0% +that single low and if I change the the +adjustment if we can have the camera + + align:start position:0% +adjustment if we can have the camera + + + align:start position:0% +adjustment if we can have the camera +looking at my adjustment + + align:start position:0% + + + + align:start position:0% + +ments then you see that I can get a + + align:start position:0% +ments then you see that I can get a + + + align:start position:0% +ments then you see that I can get a +variety of + + align:start position:0% +variety of + + + align:start position:0% +variety of +uh uh of shapes all I'm doing is + + align:start position:0% +uh uh of shapes all I'm doing is + + + align:start position:0% +uh uh of shapes all I'm doing is +changing the adjustment I can get a + + align:start position:0% +changing the adjustment I can get a + + + align:start position:0% +changing the adjustment I can get a +variety of shapes and clearly it's not + + align:start position:0% +variety of shapes and clearly it's not + + + align:start position:0% +variety of shapes and clearly it's not +like what we had before the single mode + + align:start position:0% +like what we had before the single mode + + + align:start position:0% +like what we had before the single mode +be behavior that we had + + align:start position:0% +be behavior that we had + + + align:start position:0% +be behavior that we had +before and this is then the so-called + + align:start position:0% +before and this is then the so-called + + + align:start position:0% +before and this is then the so-called +multi mode what you're seeing are are + + align:start position:0% +multi mode what you're seeing are are + + + align:start position:0% +multi mode what you're seeing are are +different transverse modes that are that + + align:start position:0% +different transverse modes that are that + + + align:start position:0% +different transverse modes that are that +can propagate in in this fiber because + + align:start position:0% +can propagate in in this fiber because + + + align:start position:0% +can propagate in in this fiber because +the core diameter is bigger but I'm + + align:start position:0% +the core diameter is bigger but I'm + + + align:start position:0% +the core diameter is bigger but I'm +going to leave it to you then to explain + + align:start position:0% +going to leave it to you then to explain + + + align:start position:0% +going to leave it to you then to explain +uh why exactly why you get higher o + + align:start position:0% +uh why exactly why you get higher o + + + align:start position:0% +uh why exactly why you get higher o +higher mode higher transverse modes + + align:start position:0% +higher mode higher transverse modes + + + align:start position:0% +higher mode higher transverse modes +propagated in this in this fiber again + + align:start position:0% +propagated in this in this fiber again + + + align:start position:0% +propagated in this in this fiber again +the wavelength is the same the only + + align:start position:0% +the wavelength is the same the only + + + align:start position:0% +the wavelength is the same the only +thing the only difference is that the + + align:start position:0% +thing the only difference is that the + + + align:start position:0% +thing the only difference is that the +core diameter is is + + align:start position:0% +core diameter is is + + + align:start position:0% +core diameter is is +bigger you can see this one here you get + + align:start position:0% +bigger you can see this one here you get + + + align:start position:0% +bigger you can see this one here you get +nice dark line in the middle + + align:start position:0% +nice dark line in the middle + + + align:start position:0% +nice dark line in the middle +and then then if I align it over here + + align:start position:0% +and then then if I align it over here + + + align:start position:0% +and then then if I align it over here +you can see it's Blobby it's a mixture + + align:start position:0% +you can see it's Blobby it's a mixture + + + align:start position:0% +you can see it's Blobby it's a mixture +of modes that's why you don't see uh + + align:start position:0% +of modes that's why you don't see uh + + + align:start position:0% +of modes that's why you don't see uh +sharp dark line in the middle but you + + align:start position:0% +sharp dark line in the middle but you + + + align:start position:0% +sharp dark line in the middle but you +get a mixture of modes while remember in + + align:start position:0% +get a mixture of modes while remember in + + + align:start position:0% +get a mixture of modes while remember in +the other one no matter what I did in + + align:start position:0% +the other one no matter what I did in + + + align:start position:0% +the other one no matter what I did in +the alignment uh it was still single + + align:start position:0% +the alignment uh it was still single + + + align:start position:0% +the alignment uh it was still single +mode uh coming out just one lob coming + + align:start position:0% +mode uh coming out just one lob coming + + + align:start position:0% +mode uh coming out just one lob coming +out all right now multimode fibers have + + align:start position:0% +out all right now multimode fibers have + + + align:start position:0% +out all right now multimode fibers have +many applications also but for today for + + align:start position:0% +many applications also but for today for + + + align:start position:0% +many applications also but for today for +a lot of sophisticated sensor + + align:start position:0% +a lot of sophisticated sensor + + + align:start position:0% +a lot of sophisticated sensor +applications and Communications + + align:start position:0% +applications and Communications + + + align:start position:0% +applications and Communications +uh one uses one generally uses single + + align:start position:0% +uh one uses one generally uses single + + + align:start position:0% +uh one uses one generally uses single +mode fibers so here here's a here's a + + align:start position:0% +mode fibers so here here's a here's a + + + align:start position:0% +mode fibers so here here's a here's a +pretty pretty mode with had a dark line + + align:start position:0% +pretty pretty mode with had a dark line + + + align:start position:0% +pretty pretty mode with had a dark line +down the uh down the middle now what I + + align:start position:0% +down the uh down the middle now what I + + + align:start position:0% +down the uh down the middle now what I +would like to do is show how how touchy + + align:start position:0% +would like to do is show how how touchy + + + align:start position:0% +would like to do is show how how touchy +uh this fiber is to to uh bending in + + align:start position:0% +uh this fiber is to to uh bending in + + + align:start position:0% +uh this fiber is to to uh bending in +fact if we take a look at the fiber here + + align:start position:0% +fact if we take a look at the fiber here + + + align:start position:0% +fact if we take a look at the fiber here +as soon as I just press on it if we get + + align:start position:0% +as soon as I just press on it if we get + + + align:start position:0% +as soon as I just press on it if we get +take a close look at if I just press on + + align:start position:0% +take a close look at if I just press on + + + align:start position:0% +take a close look at if I just press on +it uh I can kick light kick light out if + + align:start position:0% +it uh I can kick light kick light out if + + + align:start position:0% +it uh I can kick light kick light out if +I just simp press on it I can kick the + + align:start position:0% +I just simp press on it I can kick the + + + align:start position:0% +I just simp press on it I can kick the +some light out so it's very touchy to to + + align:start position:0% +some light out so it's very touchy to to + + + align:start position:0% +some light out so it's very touchy to to +to stress and to bend but I would like + + align:start position:0% +to stress and to bend but I would like + + + align:start position:0% +to stress and to bend but I would like +to do then is show + + align:start position:0% +to do then is show + + + align:start position:0% +to do then is show +that I can kick out some of the + + align:start position:0% +that I can kick out some of the + + + align:start position:0% +that I can kick out some of the +transverse modes by by simply bending or + + align:start position:0% +transverse modes by by simply bending or + + + align:start position:0% +transverse modes by by simply bending or +stressing the fiber what I'm going to do + + align:start position:0% +stressing the fiber what I'm going to do + + + align:start position:0% +stressing the fiber what I'm going to do +is then bend this fiber and if you watch + + align:start position:0% +is then bend this fiber and if you watch + + + align:start position:0% +is then bend this fiber and if you watch +in the in the inset and see that the + + align:start position:0% +in the in the inset and see that the + + + align:start position:0% +in the in the inset and see that the +intensity will go down but but if I + + align:start position:0% + + + + align:start position:0% + +keep increasing the bend I end up with + + align:start position:0% +keep increasing the bend I end up with + + + align:start position:0% +keep increasing the bend I end up with +single mod with a single mod propagation + + align:start position:0% +single mod with a single mod propagation + + + align:start position:0% +single mod with a single mod propagation +but but weat and this illustrates that + + align:start position:0% +but but weat and this illustrates that + + + align:start position:0% +but but weat and this illustrates that +you can strip + + align:start position:0% +you can strip + + + align:start position:0% +you can strip +off the high order modes uh by simply uh + + align:start position:0% +off the high order modes uh by simply uh + + + align:start position:0% +off the high order modes uh by simply uh +bending bending the fiber but the + + align:start position:0% +bending bending the fiber but the + + + align:start position:0% +bending bending the fiber but the +penalty is you get uh much less light uh + + align:start position:0% +penalty is you get uh much less light uh + + + align:start position:0% +penalty is you get uh much less light uh +getting propagate so here we have single + + align:start position:0% +getting propagate so here we have single + + + align:start position:0% +getting propagate so here we have single +mode propagation and here we have multi + + align:start position:0% +mode propagation and here we have multi + + + align:start position:0% +mode propagation and here we have multi +mode or mixture multi mode propagating + + align:start position:0% +mode or mixture multi mode propagating + + + align:start position:0% +mode or mixture multi mode propagating +in the in the fiber again you can see + + align:start position:0% +in the in the fiber again you can see + + + align:start position:0% +in the in the fiber again you can see +that the there's a lot of light that + + align:start position:0% +that the there's a lot of light that + + + align:start position:0% +that the there's a lot of light that +gets kicked out has to be kicked out of + + align:start position:0% +gets kicked out has to be kicked out of + + + align:start position:0% +gets kicked out has to be kicked out of +the fiber you can see the the bend + + align:start position:0% +the fiber you can see the the bend + + + align:start position:0% +the fiber you can see the the bend +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +glows in fact this this + + align:start position:0% +glows in fact this this + + + align:start position:0% +glows in fact this this +bending effect on on the transmission of + + align:start position:0% +bending effect on on the transmission of + + + align:start position:0% +bending effect on on the transmission of +light in a fiber can be used as a as a + + align:start position:0% +light in a fiber can be used as a as a + + + align:start position:0% +light in a fiber can be used as a as a +sensor a sensor of uh pressure sensor of + + align:start position:0% +sensor a sensor of uh pressure sensor of + + + align:start position:0% +sensor a sensor of uh pressure sensor of +stress bends and and what have you + + align:start position:0% +stress bends and and what have you + + + align:start position:0% +stress bends and and what have you +all right so then in in + + align:start position:0% +all right so then in in + + + align:start position:0% +all right so then in in +summary + + align:start position:0% +summary + + + align:start position:0% +summary +we've well that's uh that was all about + + align:start position:0% +we've well that's uh that was all about + + + align:start position:0% +we've well that's uh that was all about +transverse modes in fibers it's not uh + + align:start position:0% +transverse modes in fibers it's not uh + + + align:start position:0% +transverse modes in fibers it's not uh +easy to see these modes in normal fibers + + align:start position:0% +easy to see these modes in normal fibers + + + align:start position:0% +easy to see these modes in normal fibers +but uh I think this was a nice + + align:start position:0% +but uh I think this was a nice + + + align:start position:0% +but uh I think this was a nice +opportunity uh for you to see them and + + align:start position:0% +opportunity uh for you to see them and + + + align:start position:0% +opportunity uh for you to see them and +how how they get uh + + align:start position:0% +how how they get uh + + + align:start position:0% +how how they get uh +manipulate so what we know now about + + align:start position:0% +manipulate so what we know now about + + + align:start position:0% +manipulate so what we know now about +fibers then is that there's low loss + + align:start position:0% +fibers then is that there's low loss + + + align:start position:0% +fibers then is that there's low loss +because uh the material is correct we go + + align:start position:0% +because uh the material is correct we go + + + align:start position:0% +because uh the material is correct we go +the let's say the right wavelength and + + align:start position:0% +the let's say the right wavelength and + + + align:start position:0% +the let's say the right wavelength and +we have the let's say lowest loss if you + + align:start position:0% +we have the let's say lowest loss if you + + + align:start position:0% +we have the let's say lowest loss if you +need the lowest loss for a lot of other + + align:start position:0% +need the lowest loss for a lot of other + + + align:start position:0% +need the lowest loss for a lot of other +application like sensors and so on you + + align:start position:0% +application like sensors and so on you + + + align:start position:0% +application like sensors and so on you +know the the fact that the low loss is + + align:start position:0% +know the the fact that the low loss is + + + align:start position:0% +know the the fact that the low loss is +not the most critical + + align:start position:0% +not the most critical + + + align:start position:0% +not the most critical +fact but for certainly for + + align:start position:0% +fact but for certainly for + + + align:start position:0% +fact but for certainly for +communications and longdistance + + align:start position:0% +communications and longdistance + + + align:start position:0% +communications and longdistance +propagation that is that is very + + align:start position:0% +propagation that is that is very + + + align:start position:0% +propagation that is that is very +critical and then we also learned that + + align:start position:0% +critical and then we also learned that + + + align:start position:0% +critical and then we also learned that +we have to be careful with this V number + + align:start position:0% +we have to be careful with this V number + + + align:start position:0% +we have to be careful with this V number +so that we make sure that we have let's + + align:start position:0% +so that we make sure that we have let's + + + align:start position:0% +so that we make sure that we have let's +say when we need it we have single mode + + align:start position:0% +say when we need it we have single mode + + + align:start position:0% +say when we need it we have single mode +uh propagation see the problem problem + + align:start position:0% +uh propagation see the problem problem + + + align:start position:0% +uh propagation see the problem problem +with these multim modes they travel at + + align:start position:0% +with these multim modes they travel at + + + align:start position:0% +with these multim modes they travel at +different speeds and then as as we + + align:start position:0% +different speeds and then as as we + + + align:start position:0% +different speeds and then as as we +showed and then uh and then it prevents + + align:start position:0% +showed and then uh and then it prevents + + + align:start position:0% +showed and then uh and then it prevents +you from from using these fibers for + + align:start position:0% +you from from using these fibers for + + + align:start position:0% +you from from using these fibers for +whiteband communication so for wi band + + align:start position:0% +whiteband communication so for wi band + + + align:start position:0% +whiteband communication so for wi band +communication you really need uh the + + align:start position:0% +communication you really need uh the + + + align:start position:0% +communication you really need uh the +single mode and also what's nice about + + align:start position:0% +single mode and also what's nice about + + + align:start position:0% +single mode and also what's nice about +uh propagating it around 1.5 microns or + + align:start position:0% +uh propagating it around 1.5 microns or + + + align:start position:0% +uh propagating it around 1.5 microns or +so is that the even the refractive index + + align:start position:0% +so is that the even the refractive index + + + align:start position:0% +so is that the even the refractive index +uh uh the the variations uh in there is + + align:start position:0% +uh uh the the variations uh in there is + + + align:start position:0% +uh uh the the variations uh in there is +uh is is also small so it's it's a it's + + align:start position:0% +uh is is also small so it's it's a it's + + + align:start position:0% +uh is is also small so it's it's a it's +a nice region to propagate for for + + align:start position:0% +a nice region to propagate for for + + + align:start position:0% +a nice region to propagate for for +communication + + align:start position:0% +communication + + + align:start position:0% +communication +applications but just fibers alone is + + align:start position:0% +applications but just fibers alone is + + + align:start position:0% +applications but just fibers alone is +not everything you still have to make + + align:start position:0% +not everything you still have to make + + + align:start position:0% +not everything you still have to make +connections you know like couplers you + + align:start position:0% +connections you know like couplers you + + + align:start position:0% +connections you know like couplers you +have to have other components and so on + + align:start position:0% +have to have other components and so on + + + align:start position:0% +have to have other components and so on +so let's now spend spend a few minutes + + align:start position:0% +so let's now spend spend a few minutes + + + align:start position:0% +so let's now spend spend a few minutes +on on uh fiber optic components like + + align:start position:0% +on on uh fiber optic components like + + + align:start position:0% +on on uh fiber optic components like +couplers because if you want to split + + align:start position:0% +couplers because if you want to split + + + align:start position:0% +couplers because if you want to split +the light by 50 50 or 80 20 or so on you + + align:start position:0% +the light by 50 50 or 80 20 or so on you + + + align:start position:0% +the light by 50 50 or 80 20 or so on you +need these directional couplets all done + + align:start position:0% +need these directional couplets all done + + + align:start position:0% +need these directional couplets all done +with fibers you need the polarizers + + align:start position:0% +with fibers you need the polarizers + + + align:start position:0% +with fibers you need the polarizers +because you don't want to come out of + + align:start position:0% +because you don't want to come out of + + + align:start position:0% +because you don't want to come out of +the fiber go through a bulk optic + + align:start position:0% +the fiber go through a bulk optic + + + align:start position:0% +the fiber go through a bulk optic +polarizer and go back into the fiber + + align:start position:0% +polarizer and go back into the fiber + + + align:start position:0% +polarizer and go back into the fiber +again you'd like to create polarizers + + align:start position:0% +again you'd like to create polarizers + + + align:start position:0% +again you'd like to create polarizers +right on the fibers you like to also + + align:start position:0% +right on the fibers you like to also + + + align:start position:0% +right on the fibers you like to also +control + + align:start position:0% +control + + + align:start position:0% +control +polarization uh You' like to maybe + + align:start position:0% +polarization uh You' like to maybe + + + align:start position:0% +polarization uh You' like to maybe +create phase modulators frequency + + align:start position:0% +create phase modulators frequency + + + align:start position:0% +create phase modulators frequency +shifter and so on all in fibers now I'm + + align:start position:0% +shifter and so on all in fibers now I'm + + + align:start position:0% +shifter and so on all in fibers now I'm +not going to have time to talk about all + + align:start position:0% +not going to have time to talk about all + + + align:start position:0% +not going to have time to talk about all +these things but I'm just going to talk + + align:start position:0% +these things but I'm just going to talk + + + align:start position:0% +these things but I'm just going to talk +a little bit about couplers maybe a + + align:start position:0% +a little bit about couplers maybe a + + + align:start position:0% +a little bit about couplers maybe a +little bit about phase uh phas + + align:start position:0% +little bit about phase uh phas + + + align:start position:0% +little bit about phase uh phas +modulators so how do you make now how do + + align:start position:0% +modulators so how do you make now how do + + + align:start position:0% +modulators so how do you make now how do +we make a a uh a coupler how do we + + align:start position:0% +we make a a uh a coupler how do we + + + align:start position:0% +we make a a uh a coupler how do we +transfer light let's say we have a fiber + + align:start position:0% +transfer light let's say we have a fiber + + + align:start position:0% +transfer light let's say we have a fiber +in here and we have a core in it and + + align:start position:0% +in here and we have a core in it and + + + align:start position:0% +in here and we have a core in it and +we're propagating down the core and + + align:start position:0% +we're propagating down the core and + + + align:start position:0% +we're propagating down the core and +normally the light would come out here + + align:start position:0% +normally the light would come out here + + + align:start position:0% +normally the light would come out here +but now I'd like to transfer the light + + align:start position:0% +but now I'd like to transfer the light + + + align:start position:0% +but now I'd like to transfer the light +to to another fiber so what one one does + + align:start position:0% +to to another fiber so what one one does + + + align:start position:0% +to to another fiber so what one one does +here you bring another fiber uh close to + + align:start position:0% +here you bring another fiber uh close to + + + align:start position:0% +here you bring another fiber uh close to +to this one now if with with fibers uh + + align:start position:0% +to this one now if with with fibers uh + + + align:start position:0% +to this one now if with with fibers uh +as we said before they have a core and + + align:start position:0% +as we said before they have a core and + + + align:start position:0% +as we said before they have a core and +they have a cladding and the cladding is + + align:start position:0% +they have a cladding and the cladding is + + + align:start position:0% +they have a cladding and the cladding is +usually much bigger than the core the + + align:start position:0% +usually much bigger than the core the + + + align:start position:0% +usually much bigger than the core the +core is usually few microns the cladding + + align:start position:0% +core is usually few microns the cladding + + + align:start position:0% +core is usually few microns the cladding +is uh as I mentioned in the Dem in the + + align:start position:0% +is uh as I mentioned in the Dem in the + + + align:start position:0% +is uh as I mentioned in the Dem in the +demo it's about 125 microns so if you + + align:start position:0% +demo it's about 125 microns so if you + + + align:start position:0% +demo it's about 125 microns so if you +bring that close to this one then the + + align:start position:0% +bring that close to this one then the + + + align:start position:0% +bring that close to this one then the +the uh the two uh cladding spacing will + + align:start position:0% +the uh the two uh cladding spacing will + + + align:start position:0% +the uh the two uh cladding spacing will +not let you uh transfer any light from + + align:start position:0% +not let you uh transfer any light from + + + align:start position:0% +not let you uh transfer any light from +one fiber to the other so in order to + + align:start position:0% +one fiber to the other so in order to + + + align:start position:0% +one fiber to the other so in order to +transfer light what you have to do take + + align:start position:0% +transfer light what you have to do take + + + align:start position:0% +transfer light what you have to do take +advantage of this evanescent wave the + + align:start position:0% +advantage of this evanescent wave the + + + align:start position:0% +advantage of this evanescent wave the +part of the evanescent wave that's + + align:start position:0% +part of the evanescent wave that's + + + align:start position:0% +part of the evanescent wave that's +traveling in the clading so what you + + align:start position:0% +traveling in the clading so what you + + + align:start position:0% +traveling in the clading so what you +have to do then you have to shave off + + align:start position:0% +have to do then you have to shave off + + + align:start position:0% +have to do then you have to shave off +the cladding so that the EV that + + align:start position:0% +the cladding so that the EV that + + + align:start position:0% +the cladding so that the EV that +evanescent wave in in this fiber here + + align:start position:0% +evanescent wave in in this fiber here + + + align:start position:0% +evanescent wave in in this fiber here +Fiber One okay if if the if you shave + + align:start position:0% +Fiber One okay if if the if you shave + + + align:start position:0% +Fiber One okay if if the if you shave +enough of the cladding this evanescent + + align:start position:0% +enough of the cladding this evanescent + + + align:start position:0% +enough of the cladding this evanescent +wave can start propagating in the uh in + + align:start position:0% +wave can start propagating in the uh in + + + align:start position:0% +wave can start propagating in the uh in +the uh second fiber in fiber 2 so when + + align:start position:0% +the uh second fiber in fiber 2 so when + + + align:start position:0% +the uh second fiber in fiber 2 so when +it does that then you can transfer + + align:start position:0% +it does that then you can transfer + + + align:start position:0% +it does that then you can transfer +energy to to fiber 2 and depending on + + align:start position:0% +energy to to fiber 2 and depending on + + + align:start position:0% +energy to to fiber 2 and depending on +this interaction length length of the + + align:start position:0% +this interaction length length of the + + + align:start position:0% +this interaction length length of the +interaction the closeness of the two + + align:start position:0% +interaction the closeness of the two + + + align:start position:0% +interaction the closeness of the two +cores uh then you can transfer and uh + + align:start position:0% +cores uh then you can transfer and uh + + + align:start position:0% +cores uh then you can transfer and uh +100% and back to zero so in this plot + + align:start position:0% +100% and back to zero so in this plot + + + align:start position:0% +100% and back to zero so in this plot +here we show show that as a function of + + align:start position:0% +here we show show that as a function of + + + align:start position:0% +here we show show that as a function of +either the separation between the cores + + align:start position:0% +either the separation between the cores + + + align:start position:0% +either the separation between the cores +d sub cores the core separation or as a + + align:start position:0% +d sub cores the core separation or as a + + + align:start position:0% +d sub cores the core separation or as a +function of the interaction length for a + + align:start position:0% +function of the interaction length for a + + + align:start position:0% +function of the interaction length for a +given core separation you can transfer + + align:start position:0% +given core separation you can transfer + + + align:start position:0% +given core separation you can transfer +as much as 100% of the light you can + + align:start position:0% +as much as 100% of the light you can + + + align:start position:0% +as much as 100% of the light you can +make 100% the light come out at Port two + + align:start position:0% +make 100% the light come out at Port two + + + align:start position:0% +make 100% the light come out at Port two +instead of Port one and if you keep + + align:start position:0% +instead of Port one and if you keep + + + align:start position:0% +instead of Port one and if you keep +changing this uh coupling then you can + + align:start position:0% +changing this uh coupling then you can + + + align:start position:0% +changing this uh coupling then you can +bring it back to zero again and up again + + align:start position:0% +bring it back to zero again and up again + + + align:start position:0% +bring it back to zero again and up again +and so on so that uh so that by uh by + + align:start position:0% +and so on so that uh so that by uh by + + + align:start position:0% +and so on so that uh so that by uh by +selecting the the right uh separation + + align:start position:0% +selecting the the right uh separation + + + align:start position:0% +selecting the the right uh separation +between the cores and the right + + align:start position:0% +between the cores and the right + + + align:start position:0% +between the cores and the right +interaction length then you can have uh + + align:start position:0% +interaction length then you can have uh + + + align:start position:0% +interaction length then you can have uh +you can transfer any amount of light + + align:start position:0% +you can transfer any amount of light + + + align:start position:0% +you can transfer any amount of light +that you want and uh and this is great + + align:start position:0% +that you want and uh and this is great + + + align:start position:0% +that you want and uh and this is great +because it's it's pretty low loss and is + + align:start position:0% +because it's it's pretty low loss and is + + + align:start position:0% +because it's it's pretty low loss and is +used of course all the time today uh + + align:start position:0% +used of course all the time today uh + + + align:start position:0% +used of course all the time today uh +these couplet can be what we call the + + align:start position:0% +these couplet can be what we call the + + + align:start position:0% +these couplet can be what we call the +Polish type or the fuse type and so on + + align:start position:0% +Polish type or the fuse type and so on + + + align:start position:0% +Polish type or the fuse type and so on +they're different types of couplers but + + align:start position:0% +they're different types of couplers but + + + align:start position:0% +they're different types of couplers but +basically they work on that principle of + + align:start position:0% +basically they work on that principle of + + + align:start position:0% +basically they work on that principle of +bringing the two cores uh close enough + + align:start position:0% +bringing the two cores uh close enough + + + align:start position:0% +bringing the two cores uh close enough +together so that the evanescent wave + + align:start position:0% +together so that the evanescent wave + + + align:start position:0% +together so that the evanescent wave +that little tail of of that field + + align:start position:0% +that little tail of of that field + + + align:start position:0% +that little tail of of that field +distribution then will propagate in the + + align:start position:0% +distribution then will propagate in the + + + align:start position:0% +distribution then will propagate in the +in the other core and will drive the + + align:start position:0% +in the other core and will drive the + + + align:start position:0% +in the other core and will drive the +dipoles over there all right so that's + + align:start position:0% +dipoles over there all right so that's + + + align:start position:0% +dipoles over there all right so that's +basically the principle of a U of A of a + + align:start position:0% +basically the principle of a U of A of a + + + align:start position:0% +basically the principle of a U of A of a +coupla all right and uh now I wanted toh + + align:start position:0% +coupla all right and uh now I wanted toh + + + align:start position:0% +coupla all right and uh now I wanted toh +just say again a few words about phase + + align:start position:0% +just say again a few words about phase + + + align:start position:0% +just say again a few words about phase +modulators now uh phase modulators well + + align:start position:0% +modulators now uh phase modulators well + + + align:start position:0% +modulators now uh phase modulators well +how do you do that how do you modulate + + align:start position:0% +how do you do that how do you modulate + + + align:start position:0% +how do you do that how do you modulate +the phase of the light propagating in + + align:start position:0% +the phase of the light propagating in + + + align:start position:0% +the phase of the light propagating in +the fiber well again in many ways + + align:start position:0% +the fiber well again in many ways + + + align:start position:0% +the fiber well again in many ways +because if we stretch the fiber if we do + + align:start position:0% +because if we stretch the fiber if we do + + + align:start position:0% +because if we stretch the fiber if we do +something to the fiber uh we can uh + + align:start position:0% +something to the fiber uh we can uh + + + align:start position:0% +something to the fiber uh we can uh +change the essentially the index let's + + align:start position:0% +change the essentially the index let's + + + align:start position:0% +change the essentially the index let's +say in the in the fiber or change the + + align:start position:0% +say in the in the fiber or change the + + + align:start position:0% +say in the in the fiber or change the +physical length of the fiber and then we + + align:start position:0% +physical length of the fiber and then we + + + align:start position:0% +physical length of the fiber and then we +get a change in Phase Delta fi that's + + align:start position:0% +get a change in Phase Delta fi that's + + + align:start position:0% +get a change in Phase Delta fi that's +proportional to either change in the the + + align:start position:0% +proportional to either change in the the + + + align:start position:0% +proportional to either change in the the +length of the fiber or change in the + + align:start position:0% +length of the fiber or change in the + + + align:start position:0% +length of the fiber or change in the +index of the Fiber One way of doing this + + align:start position:0% +index of the Fiber One way of doing this + + + align:start position:0% +index of the Fiber One way of doing this +is to take the fiber and wrap it around + + align:start position:0% +is to take the fiber and wrap it around + + + align:start position:0% +is to take the fiber and wrap it around +a p Electric Crystal if we put a voltage + + align:start position:0% +a p Electric Crystal if we put a voltage + + + align:start position:0% +a p Electric Crystal if we put a voltage +between the inside the outer uh surfaces + + align:start position:0% +between the inside the outer uh surfaces + + + align:start position:0% +between the inside the outer uh surfaces +of this Crystal then we can uh change + + align:start position:0% +of this Crystal then we can uh change + + + align:start position:0% +of this Crystal then we can uh change +the diameter of this uh of this uh + + align:start position:0% +the diameter of this uh of this uh + + + align:start position:0% +the diameter of this uh of this uh +cylinder and then in this way we can + + align:start position:0% +cylinder and then in this way we can + + + align:start position:0% +cylinder and then in this way we can +change the uh the physical length of the + + align:start position:0% +change the uh the physical length of the + + + align:start position:0% +change the uh the physical length of the +fiber or by stressing it you know + + align:start position:0% +fiber or by stressing it you know + + + align:start position:0% +fiber or by stressing it you know +essentially CH could change also the + + align:start position:0% +essentially CH could change also the + + + align:start position:0% +essentially CH could change also the +index but whatever uh uh yet you get a + + align:start position:0% +index but whatever uh uh yet you get a + + + align:start position:0% +index but whatever uh uh yet you get a +change in the phase of the light + + align:start position:0% +change in the phase of the light + + + align:start position:0% +change in the phase of the light +propagating by by uh applying a voltage + + align:start position:0% +propagating by by uh applying a voltage + + + align:start position:0% +propagating by by uh applying a voltage +either DC voltage or sinusal voltage to + + align:start position:0% +either DC voltage or sinusal voltage to + + + align:start position:0% +either DC voltage or sinusal voltage to +this uh cylinder p Electric cylinder the + + align:start position:0% +this uh cylinder p Electric cylinder the + + + align:start position:0% +this uh cylinder p Electric cylinder the +another type of uh of p Electric device + + align:start position:0% +another type of uh of p Electric device + + + align:start position:0% +another type of uh of p Electric device +is is a sheet is a is a p Electric strip + + align:start position:0% +is is a sheet is a is a p Electric strip + + + align:start position:0% +is is a sheet is a is a p Electric strip +or sheet where the fiber is just uh + + align:start position:0% +or sheet where the fiber is just uh + + + align:start position:0% +or sheet where the fiber is just uh +attached to Bonded to this it doesn't + + align:start position:0% +attached to Bonded to this it doesn't + + + align:start position:0% +attached to Bonded to this it doesn't +have to Bonded that rigidly to this to + + align:start position:0% +have to Bonded that rigidly to this to + + + align:start position:0% +have to Bonded that rigidly to this to +this sheet and then by applying a + + align:start position:0% +this sheet and then by applying a + + + align:start position:0% +this sheet and then by applying a +voltage between the upper and the lower + + align:start position:0% +voltage between the upper and the lower + + + align:start position:0% +voltage between the upper and the lower +uh surface you can again stretch the uh + + align:start position:0% +uh surface you can again stretch the uh + + + align:start position:0% +uh surface you can again stretch the uh +stretch the fiber and then you can + + align:start position:0% +stretch the fiber and then you can + + + align:start position:0% +stretch the fiber and then you can +essentially modulate the the light + + align:start position:0% +essentially modulate the the light + + + align:start position:0% +essentially modulate the the light +that's propagating so uh so that's a + + align:start position:0% +that's propagating so uh so that's a + + + align:start position:0% +that's propagating so uh so that's a +very neat way you don't have to break + + align:start position:0% +very neat way you don't have to break + + + align:start position:0% +very neat way you don't have to break +the fiber it's is still still intact and + + align:start position:0% +the fiber it's is still still intact and + + + align:start position:0% +the fiber it's is still still intact and +you can get uh phase uh phase + + align:start position:0% +you can get uh phase uh phase + + + align:start position:0% +you can get uh phase uh phase +modulation now uh and then say I said + + align:start position:0% +modulation now uh and then say I said + + + align:start position:0% +modulation now uh and then say I said +before there are all kinds of uh neat uh + + align:start position:0% +before there are all kinds of uh neat uh + + + align:start position:0% +before there are all kinds of uh neat uh +devices that that uh use fibers you can + + align:start position:0% +devices that that uh use fibers you can + + + align:start position:0% +devices that that uh use fibers you can +make polarizers frequency shifters and + + align:start position:0% +make polarizers frequency shifters and + + + align:start position:0% +make polarizers frequency shifters and +uh and so on but now there is another + + align:start position:0% +uh and so on but now there is another + + + align:start position:0% +uh and so on but now there is another +field that uh is gaining momentum a lot + + align:start position:0% +field that uh is gaining momentum a lot + + + align:start position:0% +field that uh is gaining momentum a lot +and that's called integrated Optics + + align:start position:0% +and that's called integrated Optics + + + align:start position:0% +and that's called integrated Optics +because sometimes to to make these all + + align:start position:0% +because sometimes to to make these all + + + align:start position:0% +because sometimes to to make these all +fiber couplers all fiber devices becomes + + align:start position:0% +fiber couplers all fiber devices becomes + + + align:start position:0% +fiber couplers all fiber devices becomes +a little tricky and very delicate so it + + align:start position:0% +a little tricky and very delicate so it + + + align:start position:0% +a little tricky and very delicate so it +would be nice to to replace them with + + align:start position:0% +would be nice to to replace them with + + + align:start position:0% +would be nice to to replace them with +something that's more more robust so I'd + + align:start position:0% +something that's more more robust so I'd + + + align:start position:0% +something that's more more robust so I'd +like to talk a little bit about uh + + align:start position:0% +like to talk a little bit about uh + + + align:start position:0% +like to talk a little bit about uh +integrated optic + + align:start position:0% +integrated optic + + + align:start position:0% +integrated optic +components and uh and what what are uh + + align:start position:0% +components and uh and what what are uh + + + align:start position:0% +components and uh and what what are uh +integrated uh Optics first of all uh let + + align:start position:0% +integrated uh Optics first of all uh let + + + align:start position:0% +integrated uh Optics first of all uh let +me let me then uh explain to you a + + align:start position:0% +me let me then uh explain to you a + + + align:start position:0% +me let me then uh explain to you a +little bit about what's an integrated + + align:start position:0% +little bit about what's an integrated + + + align:start position:0% +little bit about what's an integrated +optic wave guide is so in this case the + + align:start position:0% +optic wave guide is so in this case the + + + align:start position:0% +optic wave guide is so in this case the +instead of it's not it's not a fiber but + + align:start position:0% +instead of it's not it's not a fiber but + + + align:start position:0% +instead of it's not it's not a fiber but +basically uh let's say you start with + + align:start position:0% +basically uh let's say you start with + + + align:start position:0% +basically uh let's say you start with +with with with some material like glass + + align:start position:0% +with with with some material like glass + + + align:start position:0% +with with with some material like glass +and then you IND defuse uh some impurity + + align:start position:0% +and then you IND defuse uh some impurity + + + align:start position:0% +and then you IND defuse uh some impurity +that raises the index and if this is + + align:start position:0% +that raises the index and if this is + + + align:start position:0% +that raises the index and if this is +controlled uh then using photo + + align:start position:0% +controlled uh then using photo + + + align:start position:0% +controlled uh then using photo +lithographic techniques and so on uh + + align:start position:0% +lithographic techniques and so on uh + + + align:start position:0% +lithographic techniques and so on uh +that you can raise the index over here + + align:start position:0% +that you can raise the index over here + + + align:start position:0% +that you can raise the index over here +so if you look from the side you have a + + align:start position:0% +so if you look from the side you have a + + + align:start position:0% +so if you look from the side you have a +material that has a little higher index + + align:start position:0% +material that has a little higher index + + + align:start position:0% +material that has a little higher index +than than uh the cladding over here and + + align:start position:0% +than than uh the cladding over here and + + + align:start position:0% +than than uh the cladding over here and +then you can propagate light down this + + align:start position:0% +then you can propagate light down this + + + align:start position:0% +then you can propagate light down this +uh this uh wave guide becomes a wave + + align:start position:0% +uh this uh wave guide becomes a wave + + + align:start position:0% +uh this uh wave guide becomes a wave +guide and you can uh and then the light + + align:start position:0% +guide and you can uh and then the light + + + align:start position:0% +guide and you can uh and then the light +is guided through the wave guide just + + align:start position:0% +is guided through the wave guide just + + + align:start position:0% +is guided through the wave guide just +like in a fiber because the index here + + align:start position:0% +like in a fiber because the index here + + + align:start position:0% +like in a fiber because the index here +is higher than one's on the side and + + align:start position:0% +is higher than one's on the side and + + + align:start position:0% +is higher than one's on the side and +then you can coat this and protect it + + align:start position:0% +then you can coat this and protect it + + + align:start position:0% +then you can coat this and protect it +and so on but the principle is that you + + align:start position:0% +and so on but the principle is that you + + + align:start position:0% +and so on but the principle is that you +can get single mode or multi mode uh uh + + align:start position:0% +can get single mode or multi mode uh uh + + + align:start position:0% +can get single mode or multi mode uh uh +wave guides in a in a substrate and it's + + align:start position:0% +wave guides in a in a substrate and it's + + + align:start position:0% +wave guides in a in a substrate and it's +rigid doesn't go anywhere and you can do + + align:start position:0% +rigid doesn't go anywhere and you can do + + + align:start position:0% +rigid doesn't go anywhere and you can do +all kinds of things with it so now with + + align:start position:0% +all kinds of things with it so now with + + + align:start position:0% +all kinds of things with it so now with +this with this idea here uh you can uh + + align:start position:0% +this with this idea here uh you can uh + + + align:start position:0% +this with this idea here uh you can uh +you can create a uh a directional + + align:start position:0% +you can create a uh a directional + + + align:start position:0% +you can create a uh a directional +coupler uh either fixed or variable + + align:start position:0% +coupler uh either fixed or variable + + + align:start position:0% +coupler uh either fixed or variable +again you can create polar ier by + + align:start position:0% +again you can create polar ier by + + + align:start position:0% +again you can create polar ier by +preventing certain polarizations the or + + align:start position:0% +preventing certain polarizations the or + + + align:start position:0% +preventing certain polarizations the or +one polarization from from going by + + align:start position:0% +one polarization from from going by + + + align:start position:0% +one polarization from from going by +attenuating it uh you can create the + + align:start position:0% +attenuating it uh you can create the + + + align:start position:0% +attenuating it uh you can create the +phase modulators frequency shifters + + align:start position:0% +phase modulators frequency shifters + + + align:start position:0% +phase modulators frequency shifters +intensity modul and so on all using + + align:start position:0% +intensity modul and so on all using + + + align:start position:0% +intensity modul and so on all using +integrated Optics so let's look at uh at + + align:start position:0% +integrated Optics so let's look at uh at + + + align:start position:0% +integrated Optics so let's look at uh at +a an + + align:start position:0% +a an + + + align:start position:0% +a an +example here again is is the substrate + + align:start position:0% +example here again is is the substrate + + + align:start position:0% +example here again is is the substrate +and here's the wave guide now if this + + align:start position:0% +and here's the wave guide now if this + + + align:start position:0% +and here's the wave guide now if this +material here is is uh before even I get + + align:start position:0% +material here is is uh before even I get + + + align:start position:0% +material here is is uh before even I get +to what I want to talk about is that you + + align:start position:0% +to what I want to talk about is that you + + + align:start position:0% +to what I want to talk about is that you +have to first couple couple to this wave + + align:start position:0% +have to first couple couple to this wave + + + align:start position:0% +have to first couple couple to this wave +guide remember the core can be very + + align:start position:0% +guide remember the core can be very + + + align:start position:0% +guide remember the core can be very +small just a few microns so you have to + + align:start position:0% +small just a few microns so you have to + + + align:start position:0% +small just a few microns so you have to +take the output from the fiber and + + align:start position:0% +take the output from the fiber and + + + align:start position:0% +take the output from the fiber and +couple it into into this core so that's + + align:start position:0% +couple it into into this core so that's + + + align:start position:0% +couple it into into this core so that's +a tricky uh device but again people have + + align:start position:0% +a tricky uh device but again people have + + + align:start position:0% +a tricky uh device but again people have +found nice techniques to to do that so + + align:start position:0% +found nice techniques to to do that so + + + align:start position:0% +found nice techniques to to do that so +basically you want a fiber to couple + + align:start position:0% +basically you want a fiber to couple + + + align:start position:0% +basically you want a fiber to couple +into this and and this to couple into + + align:start position:0% +into this and and this to couple into + + + align:start position:0% +into this and and this to couple into +the fiber going out if you can do that + + align:start position:0% +the fiber going out if you can do that + + + align:start position:0% +the fiber going out if you can do that +and and and these couplers stay uh stay + + align:start position:0% +and and and these couplers stay uh stay + + + align:start position:0% +and and and these couplers stay uh stay +together then you you've got something + + align:start position:0% +together then you you've got something + + + align:start position:0% +together then you you've got something +all right so now how do you create a + + align:start position:0% +all right so now how do you create a + + + align:start position:0% +all right so now how do you create a +phase modulator here now if this + + align:start position:0% +phase modulator here now if this + + + align:start position:0% +phase modulator here now if this +material is for example is slightly + + align:start position:0% +material is for example is slightly + + + align:start position:0% +material is for example is slightly +Electro optic or electrooptic then by + + align:start position:0% +Electro optic or electrooptic then by + + + align:start position:0% +Electro optic or electrooptic then by +putting electrodes here and applying a a + + align:start position:0% +putting electrodes here and applying a a + + + align:start position:0% +putting electrodes here and applying a a +voltage difference between them then you + + align:start position:0% +voltage difference between them then you + + + align:start position:0% +voltage difference between them then you +can change the index either in the + + align:start position:0% +can change the index either in the + + + align:start position:0% +can change the index either in the +cladding or in the core and then and + + align:start position:0% +cladding or in the core and then and + + + align:start position:0% +cladding or in the core and then and +then uh just by simply applying a + + align:start position:0% +then uh just by simply applying a + + + align:start position:0% +then uh just by simply applying a +voltage and this way you can then phase + + align:start position:0% +voltage and this way you can then phase + + + align:start position:0% +voltage and this way you can then phase +modulate the light propagating in this + + align:start position:0% +modulate the light propagating in this + + + align:start position:0% +modulate the light propagating in this +section you can do it pretty fast and + + align:start position:0% +section you can do it pretty fast and + + + align:start position:0% +section you can do it pretty fast and +then you can get very fast uh phase + + align:start position:0% +then you can get very fast uh phase + + + align:start position:0% +then you can get very fast uh phase +modulators and if you ramp the phase and + + align:start position:0% +modulators and if you ramp the phase and + + + align:start position:0% +modulators and if you ramp the phase and +so on using Codine techniques that we + + align:start position:0% +so on using Codine techniques that we + + + align:start position:0% +so on using Codine techniques that we +hear about today you can also do + + align:start position:0% +hear about today you can also do + + + align:start position:0% +hear about today you can also do +frequency shifting uh quite easily using + + align:start position:0% +frequency shifting uh quite easily using + + + align:start position:0% +frequency shifting uh quite easily using +this device now if you want to use it as + + align:start position:0% +this device now if you want to use it as + + + align:start position:0% +this device now if you want to use it as +a coupler or or as an intensity + + align:start position:0% +a coupler or or as an intensity + + + align:start position:0% +a coupler or or as an intensity +modulator and so on you have to uh + + align:start position:0% +modulator and so on you have to uh + + + align:start position:0% +modulator and so on you have to uh +combine uh several wave guides two wave + + align:start position:0% +combine uh several wave guides two wave + + + align:start position:0% +combine uh several wave guides two wave +guides together and then you can create + + align:start position:0% +guides together and then you can create + + + align:start position:0% +guides together and then you can create +a coupl and so on but here I've chosen + + align:start position:0% +a coupl and so on but here I've chosen + + + align:start position:0% +a coupl and so on but here I've chosen +uh this example here where I have one + + align:start position:0% +uh this example here where I have one + + + align:start position:0% +uh this example here where I have one +guy that looks like this and then the + + align:start position:0% +guy that looks like this and then the + + + align:start position:0% +guy that looks like this and then the +other guy that looks like that now if I + + align:start position:0% +other guy that looks like that now if I + + + align:start position:0% +other guy that looks like that now if I +put light in in in one arm then then + + align:start position:0% +put light in in in one arm then then + + + align:start position:0% +put light in in in one arm then then +again normally it would come out on uh + + align:start position:0% +again normally it would come out on uh + + + align:start position:0% +again normally it would come out on uh +over here uh but depending on the + + align:start position:0% +over here uh but depending on the + + + align:start position:0% +over here uh but depending on the +closeness of these two cores then I can + + align:start position:0% +closeness of these two cores then I can + + + align:start position:0% +closeness of these two cores then I can +get some light that will be coupled into + + align:start position:0% +get some light that will be coupled into + + + align:start position:0% +get some light that will be coupled into +this other side will come out over here + + align:start position:0% +this other side will come out over here + + + align:start position:0% +this other side will come out over here +so this is a uh let say a fixed + + align:start position:0% +so this is a uh let say a fixed + + + align:start position:0% +so this is a uh let say a fixed +coupler uh if you uh if you want to have + + align:start position:0% +coupler uh if you uh if you want to have + + + align:start position:0% +coupler uh if you uh if you want to have +a variable coupler again if this + + align:start position:0% +a variable coupler again if this + + + align:start position:0% +a variable coupler again if this +material of the substrate is is + + align:start position:0% +material of the substrate is is + + + align:start position:0% +material of the substrate is is +electrooptic then again putting + + align:start position:0% +electrooptic then again putting + + + align:start position:0% +electrooptic then again putting +electrodes on the material then you can + + align:start position:0% +electrodes on the material then you can + + + align:start position:0% +electrodes on the material then you can +change + + align:start position:0% +change + + + align:start position:0% +change +the the essentially the index here + + align:start position:0% +the the essentially the index here + + + align:start position:0% +the the essentially the index here +between the between the cores and uh and + + align:start position:0% +between the between the cores and uh and + + + align:start position:0% +between the between the cores and uh and +this way we'll change the uh the + + align:start position:0% +this way we'll change the uh the + + + align:start position:0% +this way we'll change the uh the +coupling the coupling ratio then will + + align:start position:0% +coupling the coupling ratio then will + + + align:start position:0% +coupling the coupling ratio then will +change depending on the index so I can + + align:start position:0% +change depending on the index so I can + + + align:start position:0% +change depending on the index so I can +couple more light or less light by + + align:start position:0% +couple more light or less light by + + + align:start position:0% +couple more light or less light by +applying a voltage so this is a neat + + align:start position:0% +applying a voltage so this is a neat + + + align:start position:0% +applying a voltage so this is a neat +little device and uh and then there's + + align:start position:0% +little device and uh and then there's + + + align:start position:0% +little device and uh and then there's +also other applications uh you can also + + align:start position:0% +also other applications uh you can also + + + align:start position:0% +also other applications uh you can also +use it as a as a for example as a + + align:start position:0% +use it as a as a for example as a + + + align:start position:0% +use it as a as a for example as a +intensity uh modulator by uh by again uh + + align:start position:0% +intensity uh modulator by uh by again uh + + + align:start position:0% +intensity uh modulator by uh by again uh +applying a variable voltage here and + + align:start position:0% +applying a variable voltage here and + + + align:start position:0% +applying a variable voltage here and +then you can transfer you can vary the + + align:start position:0% +then you can transfer you can vary the + + + align:start position:0% +then you can transfer you can vary the +transfer of light from here to uh from + + align:start position:0% +transfer of light from here to uh from + + + align:start position:0% +transfer of light from here to uh from +this port uh to this port and and so on + + align:start position:0% +this port uh to this port and and so on + + + align:start position:0% +this port uh to this port and and so on +so it has many many applications sensors + + align:start position:0% +so it has many many applications sensors + + + align:start position:0% +so it has many many applications sensors +and so on so this is a a very important + + align:start position:0% +and so on so this is a a very important + + + align:start position:0% +and so on so this is a a very important +uh field in in fiber optics as long as + + align:start position:0% +uh field in in fiber optics as long as + + + align:start position:0% +uh field in in fiber optics as long as +you can as long as you know how to + + align:start position:0% +you can as long as you know how to + + + align:start position:0% +you can as long as you know how to +couple uh back into fibers and in in a + + align:start position:0% +couple uh back into fibers and in in a + + + align:start position:0% +couple uh back into fibers and in in a +in a rigid way without any reflection or + + align:start position:0% +in a rigid way without any reflection or + + + align:start position:0% +in a rigid way without any reflection or +big Reflections and and so on so it's a + + align:start position:0% +big Reflections and and so on so it's a + + + align:start position:0% +big Reflections and and so on so it's a +very very very exciting uh uh + + align:start position:0% +very very very exciting uh uh + + + align:start position:0% +very very very exciting uh uh +development now what I'd like to do is + + align:start position:0% +development now what I'd like to do is + + + align:start position:0% +development now what I'd like to do is +talk a little bit about uh uh fibers for + + align:start position:0% +talk a little bit about uh uh fibers for + + + align:start position:0% +talk a little bit about uh uh fibers for +for sensors special fibers for sensors + + align:start position:0% +for sensors special fibers for sensors + + + align:start position:0% +for sensors special fibers for sensors +so far the fibers I've talked about are + + align:start position:0% +so far the fibers I've talked about are + + + align:start position:0% +so far the fibers I've talked about are +good for for + + align:start position:0% +good for for + + + align:start position:0% +good for for +communication okay single mode fibers + + align:start position:0% +communication okay single mode fibers + + + align:start position:0% +communication okay single mode fibers +low loss and and so on but for sensors + + align:start position:0% +low loss and and so on but for sensors + + + align:start position:0% +low loss and and so on but for sensors +there are all kinds of uh fibers that + + align:start position:0% +there are all kinds of uh fibers that + + + align:start position:0% +there are all kinds of uh fibers that +have been uh uh developed + + align:start position:0% +have been uh uh developed + + + align:start position:0% +have been uh uh developed +uh and it's a field that is growing a + + align:start position:0% +uh and it's a field that is growing a + + + align:start position:0% +uh and it's a field that is growing a +little difficult get started but it is + + align:start position:0% +little difficult get started but it is + + + align:start position:0% +little difficult get started but it is +it is growing now the uh the this today + + align:start position:0% +it is growing now the uh the this today + + + align:start position:0% +it is growing now the uh the this today +we have what we call polarization + + align:start position:0% +we have what we call polarization + + + align:start position:0% +we have what we call polarization +maintaining fibers these are fibers that + + align:start position:0% +maintaining fibers these are fibers that + + + align:start position:0% +maintaining fibers these are fibers that +will will if you launch the field at one + + align:start position:0% +will will if you launch the field at one + + + align:start position:0% +will will if you launch the field at one +polarization will stay in that + + align:start position:0% +polarization will stay in that + + + align:start position:0% +polarization will stay in that +polarization uh there are fibers that uh + + align:start position:0% +polarization uh there are fibers that uh + + + align:start position:0% +polarization uh there are fibers that uh +that will only propagate one one + + align:start position:0% +that will only propagate one one + + + align:start position:0% +that will only propagate one one +polarization the other polarization will + + align:start position:0% +polarization the other polarization will + + + align:start position:0% +polarization the other polarization will +not propagate is too much loss and so + + align:start position:0% +not propagate is too much loss and so + + + align:start position:0% +not propagate is too much loss and so +you have essentially like very long uh + + align:start position:0% +you have essentially like very long uh + + + align:start position:0% +you have essentially like very long uh +polarizer linear polarizer then we get + + align:start position:0% +polarizer linear polarizer then we get + + + align:start position:0% +polarizer linear polarizer then we get +to what we call coated fibers these are + + align:start position:0% +to what we call coated fibers these are + + + align:start position:0% +to what we call coated fibers these are +fibers that are coated with special + + align:start position:0% +fibers that are coated with special + + + align:start position:0% +fibers that are coated with special +materials that if they are placed in a + + align:start position:0% +materials that if they are placed in a + + + align:start position:0% +materials that if they are placed in a +certain environment then that material + + align:start position:0% +certain environment then that material + + + align:start position:0% +certain environment then that material +will will start stretching and will + + align:start position:0% +will will start stretching and will + + + align:start position:0% +will will start stretching and will +stretch the fiber with it and then you + + align:start position:0% +stretch the fiber with it and then you + + + align:start position:0% +stretch the fiber with it and then you +can make a sensor for that particular + + align:start position:0% +can make a sensor for that particular + + + align:start position:0% +can make a sensor for that particular +species that the fiber is dipped into + + align:start position:0% +species that the fiber is dipped into + + + align:start position:0% +species that the fiber is dipped into +you can also get + + align:start position:0% +you can also get + + + align:start position:0% +you can also get +uh uh other types of Coatings you can + + align:start position:0% +uh uh other types of Coatings you can + + + align:start position:0% +uh uh other types of Coatings you can +coat the material with with with a + + align:start position:0% +coat the material with with with a + + + align:start position:0% +coat the material with with with a +conducting uh material like copper or so + + align:start position:0% +conducting uh material like copper or so + + + align:start position:0% +conducting uh material like copper or so +on you can make it more sensitive to + + align:start position:0% +on you can make it more sensitive to + + + align:start position:0% +on you can make it more sensitive to +temperature you can coat the fiber with + + align:start position:0% +temperature you can coat the fiber with + + + align:start position:0% +temperature you can coat the fiber with +p Electric material and you can make it + + align:start position:0% +p Electric material and you can make it + + + align:start position:0% +p Electric material and you can make it +into phase modulator or magnetostrictive + + align:start position:0% +into phase modulator or magnetostrictive + + + align:start position:0% +into phase modulator or magnetostrictive +material and so on you can do all put + + align:start position:0% +material and so on you can do all put + + + align:start position:0% +material and so on you can do all put +all kinds of coatings on fibers and and + + align:start position:0% +all kinds of coatings on fibers and and + + + align:start position:0% +all kinds of coatings on fibers and and +use them for sensors and the jacketed + + align:start position:0% +use them for sensors and the jacketed + + + align:start position:0% +use them for sensors and the jacketed +fibers is almost like the the fiber you + + align:start position:0% +fibers is almost like the the fiber you + + + align:start position:0% +fibers is almost like the the fiber you +you put it with a jacket and then you + + align:start position:0% +you put it with a jacket and then you + + + align:start position:0% +you put it with a jacket and then you +make the jacket sensitive to just like I + + align:start position:0% +make the jacket sensitive to just like I + + + align:start position:0% +make the jacket sensitive to just like I +mentioned before to the to the species + + align:start position:0% +mentioned before to the to the species + + + align:start position:0% +mentioned before to the to the species +that the fiber is dipped into then there + + align:start position:0% +that the fiber is dipped into then there + + + align:start position:0% +that the fiber is dipped into then there +are today is a big field now the doping + + align:start position:0% +are today is a big field now the doping + + + align:start position:0% +are today is a big field now the doping +of uh of fibers and for example if you + + align:start position:0% +of uh of fibers and for example if you + + + align:start position:0% +of uh of fibers and for example if you +dope glass fiber with the admium you + + align:start position:0% +dope glass fiber with the admium you + + + align:start position:0% +dope glass fiber with the admium you +have uh and you can uh pump it with h + + align:start position:0% +have uh and you can uh pump it with h + + + align:start position:0% +have uh and you can uh pump it with h +with a laser with a semiconductor laser + + align:start position:0% +with a laser with a semiconductor laser + + + align:start position:0% +with a laser with a semiconductor laser +then you can have you can have a + + align:start position:0% +then you can have you can have a + + + align:start position:0% +then you can have you can have a +essentially an emium laser a fiber laser + + align:start position:0% +essentially an emium laser a fiber laser + + + align:start position:0% +essentially an emium laser a fiber laser +and you can make them into a uh linear + + align:start position:0% +and you can make them into a uh linear + + + align:start position:0% +and you can make them into a uh linear +lasers or ring lasers and so on uh today + + align:start position:0% +lasers or ring lasers and so on uh today + + + align:start position:0% +lasers or ring lasers and so on uh today +by doping uh doping the fiber and and + + align:start position:0% +by doping uh doping the fiber and and + + + align:start position:0% +by doping uh doping the fiber and and +this is the the background for or the + + align:start position:0% +this is the the background for or the + + + align:start position:0% +this is the the background for or the +fiber optic lasers because you dope the + + align:start position:0% +fiber optic lasers because you dope the + + + align:start position:0% +fiber optic lasers because you dope the +fiber with all kinds of uh uh uh + + align:start position:0% +fiber with all kinds of uh uh uh + + + align:start position:0% +fiber with all kinds of uh uh uh +impurities and then you you get then you + + align:start position:0% +impurities and then you you get then you + + + align:start position:0% +impurities and then you you get then you +pump you have to pump them and then + + align:start position:0% +pump you have to pump them and then + + + align:start position:0% +pump you have to pump them and then +usually these are pumped uh with a + + align:start position:0% +usually these are pumped uh with a + + + align:start position:0% +usually these are pumped uh with a +semiconductor laser or some other laser + + align:start position:0% +semiconductor laser or some other laser + + + align:start position:0% +semiconductor laser or some other laser +and then you can create all sorts of + + align:start position:0% +and then you can create all sorts of + + + align:start position:0% +and then you can create all sorts of +lasers so you got to watch this this + + align:start position:0% +lasers so you got to watch this this + + + align:start position:0% +lasers so you got to watch this this +field now it's going to be it's going to + + align:start position:0% +field now it's going to be it's going to + + + align:start position:0% +field now it's going to be it's going to +be very big then uh there's another type + + align:start position:0% +be very big then uh there's another type + + + align:start position:0% +be very big then uh there's another type +of uh of fiber where you expose the + + align:start position:0% +of uh of fiber where you expose the + + + align:start position:0% +of uh of fiber where you expose the +cladding you shave off the cladding + + align:start position:0% +cladding you shave off the cladding + + + align:start position:0% +cladding you shave off the cladding +expose the core all right so so by + + align:start position:0% +expose the core all right so so by + + + align:start position:0% +expose the core all right so so by +exposing core means that you're exposing + + align:start position:0% +exposing core means that you're exposing + + + align:start position:0% +exposing core means that you're exposing +the evanescent wave that I've talked + + align:start position:0% +the evanescent wave that I've talked + + + align:start position:0% +the evanescent wave that I've talked +about before and that can be used that + + align:start position:0% +about before and that can be used that + + + align:start position:0% +about before and that can be used that +tail of the evanescent wave can be used + + align:start position:0% +tail of the evanescent wave can be used + + + align:start position:0% +tail of the evanescent wave can be used +to uh to uh interact with Vapor or gas + + align:start position:0% +to uh to uh interact with Vapor or gas + + + align:start position:0% +to uh to uh interact with Vapor or gas +or liquid or whatever that is placed in + + align:start position:0% +or liquid or whatever that is placed in + + + align:start position:0% +or liquid or whatever that is placed in +and you can use that as a as a chemical + + align:start position:0% +and you can use that as a as a chemical + + + align:start position:0% +and you can use that as a as a chemical +sensor and then we have twin core fibers + + align:start position:0% +sensor and then we have twin core fibers + + + align:start position:0% +sensor and then we have twin core fibers +where the two cores are closed and then + + align:start position:0% +where the two cores are closed and then + + + align:start position:0% +where the two cores are closed and then +you can transfer light from one core to + + align:start position:0% +you can transfer light from one core to + + + align:start position:0% +you can transfer light from one core to +the other all the way down the fiber and + + align:start position:0% +the other all the way down the fiber and + + + align:start position:0% +the other all the way down the fiber and +this can be used for uh for temperature + + align:start position:0% +this can be used for uh for temperature + + + align:start position:0% +this can be used for uh for temperature +stress and and so on let's say there's + + align:start position:0% +stress and and so on let's say there's + + + align:start position:0% +stress and and so on let's say there's +is a this is a huge field and I think we + + align:start position:0% +is a this is a huge field and I think we + + + align:start position:0% +is a this is a huge field and I think we +need a whole uh one day uh on uh uh + + align:start position:0% +need a whole uh one day uh on uh uh + + + align:start position:0% +need a whole uh one day uh on uh uh +course on uh on fibers so so now I'm + + align:start position:0% +course on uh on fibers so so now I'm + + + align:start position:0% +course on uh on fibers so so now I'm +getting close to to the end uh and I + + align:start position:0% +getting close to to the end uh and I + + + align:start position:0% +getting close to to the end uh and I +hope I've got some ideas across about + + align:start position:0% +hope I've got some ideas across about + + + align:start position:0% +hope I've got some ideas across about +basics of fibers without again without + + align:start position:0% +basics of fibers without again without + + + align:start position:0% +basics of fibers without again without +using math without scaring you off but + + align:start position:0% +using math without scaring you off but + + + align:start position:0% +using math without scaring you off but +obviously if if uh if you have interest + + align:start position:0% +obviously if if uh if you have interest + + + align:start position:0% +obviously if if uh if you have interest +in these things you have to consult the + + align:start position:0% +in these things you have to consult the + + + align:start position:0% +in these things you have to consult the +literature or take uh take other courses + + align:start position:0% +literature or take uh take other courses + + + align:start position:0% +literature or take uh take other courses +uh in the few minutes remaining I would + + align:start position:0% +uh in the few minutes remaining I would + + + align:start position:0% +uh in the few minutes remaining I would +like to talk about just a few words + + align:start position:0% +like to talk about just a few words + + + align:start position:0% +like to talk about just a few words +about some future uh developments both + + align:start position:0% +about some future uh developments both + + + align:start position:0% +about some future uh developments both +in lasers and and fiber optics uh the uh + + align:start position:0% +in lasers and and fiber optics uh the uh + + + align:start position:0% +in lasers and and fiber optics uh the uh +in terms of lasers uh suddenly we're + + align:start position:0% +in terms of lasers uh suddenly we're + + + align:start position:0% +in terms of lasers uh suddenly we're +going to see the rise and we're already + + align:start position:0% +going to see the rise and we're already + + + align:start position:0% +going to see the rise and we're already +seeing the rise of semiconductor lasers + + align:start position:0% +seeing the rise of semiconductor lasers + + + align:start position:0% +seeing the rise of semiconductor lasers +you know for all sorts of applications + + align:start position:0% +you know for all sorts of applications + + + align:start position:0% +you know for all sorts of applications +CDs and so on but we're also we're going + + align:start position:0% +CDs and so on but we're also we're going + + + align:start position:0% +CDs and so on but we're also we're going +to see them + + align:start position:0% +to see them + + + align:start position:0% +to see them +replacing the red helium neon laser + + align:start position:0% +replacing the red helium neon laser + + + align:start position:0% +replacing the red helium neon laser +today they're already available and in + + align:start position:0% +today they're already available and in + + + align:start position:0% +today they're already available and in +fact you see them as pointers and so on + + align:start position:0% +fact you see them as pointers and so on + + + align:start position:0% +fact you see them as pointers and so on +uh and uh and and so they have very neat + + align:start position:0% +uh and uh and and so they have very neat + + + align:start position:0% +uh and uh and and so they have very neat +little devices and for applications that + + align:start position:0% +little devices and for applications that + + + align:start position:0% +little devices and for applications that +don't require strict uh wavelength + + align:start position:0% +don't require strict uh wavelength + + + align:start position:0% +don't require strict uh wavelength +stability and what have you I mean the + + align:start position:0% +stability and what have you I mean the + + + align:start position:0% +stability and what have you I mean the +these These are great uh lasers we're + + align:start position:0% +these These are great uh lasers we're + + + align:start position:0% +these These are great uh lasers we're +also seeing and we'll see much more + + align:start position:0% +also seeing and we'll see much more + + + align:start position:0% +also seeing and we'll see much more +semiconductor lasers that are used to + + align:start position:0% +semiconductor lasers that are used to + + + align:start position:0% +semiconductor lasers that are used to +pump solid state lasers and fiber lasers + + align:start position:0% +pump solid state lasers and fiber lasers + + + align:start position:0% +pump solid state lasers and fiber lasers +waveguide lasers and and so on and this + + align:start position:0% +waveguide lasers and and so on and this + + + align:start position:0% +waveguide lasers and and so on and this +is a very nice application for + + align:start position:0% +is a very nice application for + + + align:start position:0% +is a very nice application for +Semiconductor lasers because again you + + align:start position:0% +Semiconductor lasers because again you + + + align:start position:0% +Semiconductor lasers because again you +don't have to worry about the the + + align:start position:0% +don't have to worry about the the + + + align:start position:0% +don't have to worry about the the +stability of wavelength and so on and + + align:start position:0% +stability of wavelength and so on and + + + align:start position:0% +stability of wavelength and so on and +then they can they can uh pump very well + + align:start position:0% +then they can they can uh pump very well + + + align:start position:0% +then they can they can uh pump very well +behaved uh Solid State uh lasers and + + align:start position:0% +behaved uh Solid State uh lasers and + + + align:start position:0% +behaved uh Solid State uh lasers and +today these can be also very big they + + align:start position:0% +today these can be also very big they + + + align:start position:0% +today these can be also very big they +don't have to be very small they can be + + align:start position:0% +don't have to be very small they can be + + + align:start position:0% +don't have to be very small they can be +very big and you have the array of + + align:start position:0% +very big and you have the array of + + + align:start position:0% +very big and you have the array of +semiconductor lasers that will will pump + + align:start position:0% +semiconductor lasers that will will pump + + + align:start position:0% +semiconductor lasers that will will pump +them and then we go from the big to the + + align:start position:0% +them and then we go from the big to the + + + align:start position:0% +them and then we go from the big to the +small we have even microchip lasers they + + align:start position:0% +small we have even microchip lasers they + + + align:start position:0% +small we have even microchip lasers they +very tiny crystals and then they are + + align:start position:0% +very tiny crystals and then they are + + + align:start position:0% +very tiny crystals and then they are +pumped again with let's say + + align:start position:0% +pumped again with let's say + + + align:start position:0% +pumped again with let's say +semiconductor lasers or other lasers but + + align:start position:0% +semiconductor lasers or other lasers but + + + align:start position:0% +semiconductor lasers or other lasers but +they're very tiny and they can be single + + align:start position:0% +they're very tiny and they can be single + + + align:start position:0% +they're very tiny and they can be single +frequency and tunable and so on and the + + align:start position:0% +frequency and tunable and so on and the + + + align:start position:0% +frequency and tunable and so on and the +fiber optic lasers well we already we + + align:start position:0% +fiber optic lasers well we already we + + + align:start position:0% +fiber optic lasers well we already we +already mentioned there all sorts of + + align:start position:0% +already mentioned there all sorts of + + + align:start position:0% +already mentioned there all sorts of +materials being looked at and uh and + + align:start position:0% +materials being looked at and uh and + + + align:start position:0% +materials being looked at and uh and +pumping uh sources and then the thin + + align:start position:0% +pumping uh sources and then the thin + + + align:start position:0% +pumping uh sources and then the thin +film wave guides well we talked about + + align:start position:0% +film wave guides well we talked about + + + align:start position:0% +film wave guides well we talked about +wave guides all you have to do is you + + align:start position:0% +wave guides all you have to do is you + + + align:start position:0% +wave guides all you have to do is you +dope that wave guide pump it with a with + + align:start position:0% +dope that wave guide pump it with a with + + + align:start position:0% +dope that wave guide pump it with a with +a with a optical pump and then you've + + align:start position:0% +a with a optical pump and then you've + + + align:start position:0% +a with a optical pump and then you've +got yourself a a laser in that in that + + align:start position:0% +got yourself a a laser in that in that + + + align:start position:0% +got yourself a a laser in that in that +substrate and then we vacuum ultraviolet + + align:start position:0% +substrate and then we vacuum ultraviolet + + + align:start position:0% +substrate and then we vacuum ultraviolet +lasers are very important in medical + + align:start position:0% +lasers are very important in medical + + + align:start position:0% +lasers are very important in medical +applications and other applications and + + align:start position:0% +applications and other applications and + + + align:start position:0% +applications and other applications and +we're seeing lots of uh new developments + + align:start position:0% +we're seeing lots of uh new developments + + + align:start position:0% +we're seeing lots of uh new developments +uh in here and also x-ray lasers you + + align:start position:0% +uh in here and also x-ray lasers you + + + align:start position:0% +uh in here and also x-ray lasers you +know the early uh early stages they + + align:start position:0% +know the early uh early stages they + + + align:start position:0% +know the early uh early stages they +classified the development but now I + + align:start position:0% +classified the development but now I + + + align:start position:0% +classified the development but now I +think uh the literature now we we see + + align:start position:0% +think uh the literature now we we see + + + align:start position:0% +think uh the literature now we we see +all kinds of work going on in x-ray + + align:start position:0% +all kinds of work going on in x-ray + + + align:start position:0% +all kinds of work going on in x-ray +lasers with again completely exciting + + align:start position:0% +lasers with again completely exciting + + + align:start position:0% +lasers with again completely exciting +area of of applications for x-ray lasers + + align:start position:0% +area of of applications for x-ray lasers + + + align:start position:0% +area of of applications for x-ray lasers +now this is the lasers now in terms of + + align:start position:0% +now this is the lasers now in terms of + + + align:start position:0% +now this is the lasers now in terms of +applications the uh you know I mentioned + + align:start position:0% +applications the uh you know I mentioned + + + align:start position:0% +applications the uh you know I mentioned +before fiber optic communication that's + + align:start position:0% +before fiber optic communication that's + + + align:start position:0% +before fiber optic communication that's +a huge application and we're going to + + align:start position:0% +a huge application and we're going to + + + align:start position:0% +a huge application and we're going to +see + + align:start position:0% +see + + + align:start position:0% +see +uh I think uh not that far uh uh we're + + align:start position:0% +uh I think uh not that far uh uh we're + + + align:start position:0% +uh I think uh not that far uh uh we're +going to see that our homes and all that + + align:start position:0% +going to see that our homes and all that + + + align:start position:0% +going to see that our homes and all that +will be linked with with fiber optic uh + + align:start position:0% +will be linked with with fiber optic uh + + + align:start position:0% +will be linked with with fiber optic uh +uh cables and this way we can have huge + + align:start position:0% +uh cables and this way we can have huge + + + align:start position:0% +uh cables and this way we can have huge +bandwidth it's going to be uh + + align:start position:0% +bandwidth it's going to be uh + + + align:start position:0% +bandwidth it's going to be uh +transmitted in uh in these fibers and + + align:start position:0% +transmitted in uh in these fibers and + + + align:start position:0% +transmitted in uh in these fibers and +then uh we can send all kinds of + + align:start position:0% +then uh we can send all kinds of + + + align:start position:0% +then uh we can send all kinds of +information all over the place uh this + + align:start position:0% +information all over the place uh this + + + align:start position:0% +information all over the place uh this +area is of materials processing again + + align:start position:0% +area is of materials processing again + + + align:start position:0% +area is of materials processing again +because of the availability of variety + + align:start position:0% +because of the availability of variety + + + align:start position:0% +because of the availability of variety +of lasers that is uh that certainly uh + + align:start position:0% +of lasers that is uh that certainly uh + + + align:start position:0% +of lasers that is uh that certainly uh +is increasing and uh and the variety is + + align:start position:0% +is increasing and uh and the variety is + + + align:start position:0% +is increasing and uh and the variety is +also increasing and medical procedures + + align:start position:0% +also increasing and medical procedures + + + align:start position:0% +also increasing and medical procedures +is uh if you keep up with what's going + + align:start position:0% +is uh if you keep up with what's going + + + align:start position:0% +is uh if you keep up with what's going +on it's it's it's incredible what the uh + + align:start position:0% +on it's it's it's incredible what the uh + + + align:start position:0% +on it's it's it's incredible what the uh +lasers are being used for procedures and + + align:start position:0% +lasers are being used for procedures and + + + align:start position:0% +lasers are being used for procedures and +for Diagnostics and and so on now here's + + align:start position:0% +for Diagnostics and and so on now here's + + + align:start position:0% +for Diagnostics and and so on now here's +a here's a tough area data processing uh + + align:start position:0% +a here's a tough area data processing uh + + + align:start position:0% +a here's a tough area data processing uh +lasers are being used but uh but + + align:start position:0% +lasers are being used but uh but + + + align:start position:0% +lasers are being used but uh but +hopefully uh the uh the uh will increase + + align:start position:0% +hopefully uh the uh the uh will increase + + + align:start position:0% +hopefully uh the uh the uh will increase +more you can take very fast for your + + align:start position:0% +more you can take very fast for your + + + align:start position:0% +more you can take very fast for your +transforms Optical Techni techniques but + + align:start position:0% +transforms Optical Techni techniques but + + + align:start position:0% +transforms Optical Techni techniques but +again you have the implementation of + + align:start position:0% +again you have the implementation of + + + align:start position:0% +again you have the implementation of +them is not is not that easy uh now + + align:start position:0% +them is not is not that easy uh now + + + align:start position:0% +them is not is not that easy uh now +sensors I've already mentioned some + + align:start position:0% +sensors I've already mentioned some + + + align:start position:0% +sensors I've already mentioned some +words about sensors but not just fiber + + align:start position:0% +words about sensors but not just fiber + + + align:start position:0% +words about sensors but not just fiber +optic sensors but all kinds of optical + + align:start position:0% +optic sensors but all kinds of optical + + + align:start position:0% +optic sensors but all kinds of optical +sensors they are they are incredible + + align:start position:0% +sensors they are they are incredible + + + align:start position:0% +sensors they are they are incredible +devices in the sense that that they're + + align:start position:0% +devices in the sense that that they're + + + align:start position:0% +devices in the sense that that they're +not affected by especially the fiber + + align:start position:0% +not affected by especially the fiber + + + align:start position:0% +not affected by especially the fiber +optic sensors they're not affected by + + align:start position:0% +optic sensors they're not affected by + + + align:start position:0% +optic sensors they're not affected by +electromagnetic interference and uh and + + align:start position:0% +electromagnetic interference and uh and + + + align:start position:0% +electromagnetic interference and uh and +they can be used in all sorts of uh + + align:start position:0% +they can be used in all sorts of uh + + + align:start position:0% +they can be used in all sorts of uh +hostile kind of uh environments that + + align:start position:0% +hostile kind of uh environments that + + + align:start position:0% +hostile kind of uh environments that +normal electrical s would not would not + + align:start position:0% +normal electrical s would not would not + + + align:start position:0% +normal electrical s would not would not +work at all because they will be uh + + align:start position:0% +work at all because they will be uh + + + align:start position:0% +work at all because they will be uh +affected by uh the electromagnetic + + align:start position:0% +affected by uh the electromagnetic + + + align:start position:0% +affected by uh the electromagnetic +interference um the uh also because uh + + align:start position:0% +interference um the uh also because uh + + + align:start position:0% +interference um the uh also because uh +fiber optics uh fibers have low loss you + + align:start position:0% +fiber optics uh fibers have low loss you + + + align:start position:0% +fiber optics uh fibers have low loss you +can have all kinds of distributed uh + + align:start position:0% +can have all kinds of distributed uh + + + align:start position:0% +can have all kinds of distributed uh +sensors and uh and uh and so on because + + align:start position:0% +sensors and uh and uh and so on because + + + align:start position:0% +sensors and uh and uh and so on because +the uh the the the fiber as I say + + align:start position:0% +the uh the the the fiber as I say + + + align:start position:0% +the uh the the the fiber as I say +doesn't have any law so you can place + + align:start position:0% +doesn't have any law so you can place + + + align:start position:0% +doesn't have any law so you can place +sort of sensors all over the place place + + align:start position:0% +sort of sensors all over the place place + + + align:start position:0% +sort of sensors all over the place place +and collect data from a large area now I + + align:start position:0% +and collect data from a large area now I + + + align:start position:0% +and collect data from a large area now I +mentioned earlier Precision positioning + + align:start position:0% +mentioned earlier Precision positioning + + + align:start position:0% +mentioned earlier Precision positioning +this is based on interferometry laser + + align:start position:0% +this is based on interferometry laser + + + align:start position:0% +this is based on interferometry laser +interferometry using laser + + align:start position:0% +interferometry using laser + + + align:start position:0% +interferometry using laser +interferometry you can uh uh monitor the + + align:start position:0% +interferometry you can uh uh monitor the + + + align:start position:0% +interferometry you can uh uh monitor the +positions of work pieces and uh and so + + align:start position:0% +positions of work pieces and uh and so + + + align:start position:0% +positions of work pieces and uh and so +on uh and dimensions and sizes and + + align:start position:0% +on uh and dimensions and sizes and + + + align:start position:0% +on uh and dimensions and sizes and +movements of all kinds of things and you + + align:start position:0% +movements of all kinds of things and you + + + align:start position:0% +movements of all kinds of things and you +can put them in feedback loops and they + + align:start position:0% +can put them in feedback loops and they + + + align:start position:0% +can put them in feedback loops and they +uh they improve things for you then + + align:start position:0% +uh they improve things for you then + + + align:start position:0% +uh they improve things for you then +laser shows I don't know I don't keep up + + align:start position:0% +laser shows I don't know I don't keep up + + + align:start position:0% +laser shows I don't know I don't keep up +with laser shows but every time I see + + align:start position:0% +with laser shows but every time I see + + + align:start position:0% +with laser shows but every time I see +them they always fascinate me because + + align:start position:0% +them they always fascinate me because + + + align:start position:0% +them they always fascinate me because +I'm always curious about what kind of + + align:start position:0% +I'm always curious about what kind of + + + align:start position:0% +I'm always curious about what kind of +lasers they using and today they can use + + align:start position:0% +lasers they using and today they can use + + + align:start position:0% +lasers they using and today they can use +them to write all kinds of patterns and + + align:start position:0% +them to write all kinds of patterns and + + + align:start position:0% +them to write all kinds of patterns and +uh and messages and so on uh for people + + align:start position:0% +uh and messages and so on uh for people + + + align:start position:0% +uh and messages and so on uh for people +then there's the computer interconnects + + align:start position:0% +then there's the computer interconnects + + + align:start position:0% +then there's the computer interconnects +these are the fiber optics or integrated + + align:start position:0% +these are the fiber optics or integrated + + + align:start position:0% +these are the fiber optics or integrated +Optics that are being used for for + + align:start position:0% +Optics that are being used for for + + + align:start position:0% +Optics that are being used for for +connecting uh computers or even + + align:start position:0% +connecting uh computers or even + + + align:start position:0% +connecting uh computers or even +connecting uh boards and uh and + + align:start position:0% +connecting uh boards and uh and + + + align:start position:0% +connecting uh boards and uh and +hopefully U sometime in the near future + + align:start position:0% +hopefully U sometime in the near future + + + align:start position:0% +hopefully U sometime in the near future +we will see all Optical computers now + + align:start position:0% +we will see all Optical computers now + + + align:start position:0% +we will see all Optical computers now +these will be very fast based on these + + align:start position:0% +these will be very fast based on these + + + align:start position:0% +these will be very fast based on these +mod loock very short pulses and but + + align:start position:0% +mod loock very short pulses and but + + + align:start position:0% +mod loock very short pulses and but +there are a lot of challenges and uh + + align:start position:0% +there are a lot of challenges and uh + + + align:start position:0% +there are a lot of challenges and uh +hopefully some of these challenges will + + align:start position:0% +hopefully some of these challenges will + + + align:start position:0% +hopefully some of these challenges will +be overcome then in terms of high + + align:start position:0% +be overcome then in terms of high + + + align:start position:0% +be overcome then in terms of high +density memories well we already seeing + + align:start position:0% +density memories well we already seeing + + + align:start position:0% +density memories well we already seeing +that now and uh and then but hopefully + + align:start position:0% +that now and uh and then but hopefully + + + align:start position:0% +that now and uh and then but hopefully +they will even be uh even more dense you + + align:start position:0% +they will even be uh even more dense you + + + align:start position:0% +they will even be uh even more dense you +taking advantage of uh of + + align:start position:0% +taking advantage of uh of + + + align:start position:0% +taking advantage of uh of +three-dimensional uh uh structures and + + align:start position:0% +three-dimensional uh uh structures and + + + align:start position:0% +three-dimensional uh uh structures and +so on and finally I'd love to see some + + align:start position:0% +so on and finally I'd love to see some + + + align:start position:0% +so on and finally I'd love to see some +color holography becoming uh becoming + + align:start position:0% +color holography becoming uh becoming + + + align:start position:0% +color holography becoming uh becoming +popular so that we can have all sorts of + + align:start position:0% +popular so that we can have all sorts of + + + align:start position:0% +popular so that we can have all sorts of +color Holograms around around our + + align:start position:0% +color Holograms around around our + + + align:start position:0% +color Holograms around around our +workplaces around our homes and so on + + align:start position:0% +workplaces around our homes and so on + + + align:start position:0% +workplaces around our homes and so on +it's a uh so far there's all kinds of + + align:start position:0% +it's a uh so far there's all kinds of + + + align:start position:0% +it's a uh so far there's all kinds of +kind of holography available but the + + align:start position:0% +kind of holography available but the + + + align:start position:0% +kind of holography available but the +true color holography even though it is + + align:start position:0% +true color holography even though it is + + + align:start position:0% +true color holography even though it is +feasible we haven't we haven't seen them + + align:start position:0% +feasible we haven't we haven't seen them + + + align:start position:0% +feasible we haven't we haven't seen them +at least uh that available so that one + + align:start position:0% +at least uh that available so that one + + + align:start position:0% +at least uh that available so that one +can uh purchase them and uh put them up + + align:start position:0% +can uh purchase them and uh put them up + + + align:start position:0% +can uh purchase them and uh put them up +on the wall I I see that uh that my time + + align:start position:0% +on the wall I I see that uh that my time + + + align:start position:0% +on the wall I I see that uh that my time +is uh is close to coming up uh to an end + + align:start position:0% +is uh is close to coming up uh to an end + + + align:start position:0% +is uh is close to coming up uh to an end +and I hope that I've been able to to get + + align:start position:0% +and I hope that I've been able to to get + + + align:start position:0% +and I hope that I've been able to to get +some ideas across to you again without + + align:start position:0% +some ideas across to you again without + + + align:start position:0% +some ideas across to you again without +without scaring you off certainly I hope + + align:start position:0% +without scaring you off certainly I hope + + + align:start position:0% +without scaring you off certainly I hope +that for those of you who didn't have + + align:start position:0% +that for those of you who didn't have + + + align:start position:0% +that for those of you who didn't have +too much background I hope you have + + align:start position:0% +too much background I hope you have + + + align:start position:0% +too much background I hope you have +motivate motivated you take some + + align:start position:0% +motivate motivated you take some + + + align:start position:0% +motivate motivated you take some +interest in lasers in fiber optics and + + align:start position:0% +interest in lasers in fiber optics and + + + align:start position:0% +interest in lasers in fiber optics and +maybe you can find some new applications + + align:start position:0% +maybe you can find some new applications + + + align:start position:0% +maybe you can find some new applications +uh for them because the field is is very + + align:start position:0% +uh for them because the field is is very + + + align:start position:0% +uh for them because the field is is very +young and it needs it needs some + + align:start position:0% +young and it needs it needs some + + + align:start position:0% +young and it needs it needs some +energetic people that will come in and + + align:start position:0% +energetic people that will come in and + + + align:start position:0% +energetic people that will come in and +especially from from different fields + + align:start position:0% +especially from from different fields + + + align:start position:0% +especially from from different fields +it's not always you want should always + + align:start position:0% +it's not always you want should always + + + align:start position:0% +it's not always you want should always +uh talk to people in in in the Optics + + align:start position:0% +uh talk to people in in in the Optics + + + align:start position:0% +uh talk to people in in in the Optics +and Laser field one should be talking to + + align:start position:0% +and Laser field one should be talking to + + + align:start position:0% +and Laser field one should be talking to +to others in other fields maybe they'll + + align:start position:0% +to others in other fields maybe they'll + + + align:start position:0% +to others in other fields maybe they'll +recognize they'll recognize uh some new + + align:start position:0% +recognize they'll recognize uh some new + + + align:start position:0% +recognize they'll recognize uh some new +applications as we can see there really + + align:start position:0% +applications as we can see there really + + + align:start position:0% +applications as we can see there really +so many applications of of lasers and + + align:start position:0% +so many applications of of lasers and + + + align:start position:0% +so many applications of of lasers and +fiber optics now be before I close I I'd + + align:start position:0% +fiber optics now be before I close I I'd + + + align:start position:0% +fiber optics now be before I close I I'd +like to thank uh two of my graduate + + align:start position:0% +like to thank uh two of my graduate + + + align:start position:0% +like to thank uh two of my graduate +students um Steve Smith and farads + + align:start position:0% +students um Steve Smith and farads + + + align:start position:0% +students um Steve Smith and farads +arichi uh now I have put them in a + + align:start position:0% +arichi uh now I have put them in a + + + align:start position:0% +arichi uh now I have put them in a +circle here because it's uh difficult to + + align:start position:0% +circle here because it's uh difficult to + + + align:start position:0% +circle here because it's uh difficult to +uh choose between them uh although farad + + align:start position:0% +uh choose between them uh although farad + + + align:start position:0% +uh choose between them uh although farad +zarich has now uh graduated uh Steve + + align:start position:0% +zarich has now uh graduated uh Steve + + + align:start position:0% +zarich has now uh graduated uh Steve +Smith is uh is uh going to be graduating + + align:start position:0% +Smith is uh is uh going to be graduating + + + align:start position:0% +Smith is uh is uh going to be graduating +soon and uh they've helped uh + + align:start position:0% +soon and uh they've helped uh + + + align:start position:0% +soon and uh they've helped uh +considerably in the in the creation of + + align:start position:0% +considerably in the in the creation of + + + align:start position:0% +considerably in the in the creation of +the of the demonstrations and also in + + align:start position:0% +the of the demonstrations and also in + + + align:start position:0% +the of the demonstrations and also in +the Creations creation of the of these + + align:start position:0% +the Creations creation of the of these + + + align:start position:0% +the Creations creation of the of these +visuals uh I hope that you found them uh + + align:start position:0% +visuals uh I hope that you found them uh + + + align:start position:0% +visuals uh I hope that you found them uh +readable and and without without a + + align:start position:0% +readable and and without without a + + + align:start position:0% +readable and and without without a +strain so I think I'm I'm almost dead on + + align:start position:0% +strain so I think I'm I'm almost dead on + + + align:start position:0% +strain so I think I'm I'm almost dead on +time and I'd like to thank you for uh + + align:start position:0% +time and I'd like to thank you for uh + + + align:start position:0% +time and I'd like to thank you for uh +for listening and and if you have any + + align:start position:0% +for listening and and if you have any + + + align:start position:0% +for listening and and if you have any +questions or so on I think you have our + + align:start position:0% +questions or so on I think you have our + + + align:start position:0% +questions or so on I think you have our +phone numbers here at MIT and you can + + align:start position:0% +phone numbers here at MIT and you can + + + align:start position:0% +phone numbers here at MIT and you can +call and we can continue with this uh + + align:start position:0% +call and we can continue with this uh + + + align:start position:0% +call and we can continue with this uh +conversation goodbye for now \ No newline at end of file diff --git a/0XjWRilFPQY.txt b/0XjWRilFPQY.txt new file mode 100644 index 0000000000000000000000000000000000000000..4a2be198fec7d2d3510282fdf6e01631c8c5e50a --- /dev/null +++ b/0XjWRilFPQY.txt @@ -0,0 +1,13384 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so welcome tonight + + align:start position:0% +so welcome tonight + + + align:start position:0% +so welcome tonight +a very special lecture for me tonight + + align:start position:0% +a very special lecture for me tonight + + + align:start position:0% +a very special lecture for me tonight +in more ways i can express + + align:start position:0% +in more ways i can express + + + align:start position:0% +in more ways i can express +this is the last of my lectures but i + + align:start position:0% +this is the last of my lectures but i + + + align:start position:0% +this is the last of my lectures but i +look forward to uh + + align:start position:0% +look forward to uh + + + align:start position:0% +look forward to uh +your lectures coming up i really do i've + + align:start position:0% +your lectures coming up i really do i've + + + align:start position:0% +your lectures coming up i really do i've +heard from the ts and from what i've + + align:start position:0% +heard from the ts and from what i've + + + align:start position:0% +heard from the ts and from what i've +seen from talking to many of you this is + + align:start position:0% +seen from talking to many of you this is + + + align:start position:0% +seen from talking to many of you this is +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +a really amazing set of projects this + + align:start position:0% +a really amazing set of projects this + + + align:start position:0% +a really amazing set of projects this +year more than any other year + + align:start position:0% +year more than any other year + + + align:start position:0% +year more than any other year +anyway + + align:start position:0% + + + + align:start position:0% + +last week we asked what can biology do + + align:start position:0% +last week we asked what can biology do + + + align:start position:0% +last week we asked what can biology do +for computing + + align:start position:0% +for computing + + + align:start position:0% +for computing +and this week + + align:start position:0% +and this week + + + align:start position:0% +and this week +is going to be a little less nuts and + + align:start position:0% +is going to be a little less nuts and + + + align:start position:0% +is going to be a little less nuts and +bolts than usual the entire course as + + align:start position:0% +bolts than usual the entire course as + + + align:start position:0% +bolts than usual the entire course as +you all understand you're all + + align:start position:0% +you all understand you're all + + + align:start position:0% +you all understand you're all +self-selected to like survey courses or + + align:start position:0% +self-selected to like survey courses or + + + align:start position:0% +self-selected to like survey courses or +at least this one + + align:start position:0% +at least this one + + + align:start position:0% +at least this one +because you're still here and tonight's + + align:start position:0% +because you're still here and tonight's + + + align:start position:0% +because you're still here and tonight's +going to be more of a survey + + align:start position:0% +going to be more of a survey + + + align:start position:0% +going to be more of a survey +than ever before and to be talking about + + align:start position:0% +than ever before and to be talking about + + + align:start position:0% +than ever before and to be talking about +topics for which we don't have answers + + align:start position:0% +topics for which we don't have answers + + + align:start position:0% +topics for which we don't have answers +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +for the most part there'll be some + + align:start position:0% +for the most part there'll be some + + + align:start position:0% +for the most part there'll be some +interesting details along the way + + align:start position:0% +interesting details along the way + + + align:start position:0% +interesting details along the way +but anyway instead of what computing can + + align:start position:0% +but anyway instead of what computing can + + + align:start position:0% +but anyway instead of what computing can +biology can do for computing this is + + align:start position:0% +biology can do for computing this is + + + align:start position:0% +biology can do for computing this is +more about what biology and computing + + align:start position:0% +more about what biology and computing + + + align:start position:0% +more about what biology and computing +can do for the world that's really what + + align:start position:0% +can do for the world that's really what + + + align:start position:0% +can do for the world that's really what +we want to do + + align:start position:0% +we want to do + + + align:start position:0% +we want to do +and also sort of the higher level + + align:start position:0% +and also sort of the higher level + + + align:start position:0% +and also sort of the higher level +network models that we can build since + + align:start position:0% +network models that we can build since + + + align:start position:0% +network models that we can build since +this is network number three + + align:start position:0% +this is network number three + + + align:start position:0% +this is network number three +so we'll start out + + align:start position:0% +so we'll start out + + + align:start position:0% +so we'll start out +we've been talking mainly about cellular + + align:start position:0% +we've been talking mainly about cellular + + + align:start position:0% +we've been talking mainly about cellular +models as our highest level of + + align:start position:0% +models as our highest level of + + + align:start position:0% +models as our highest level of +networking and so we'll talk about + + align:start position:0% +networking and so we'll talk about + + + align:start position:0% +networking and so we'll talk about +multi-cellular models + + align:start position:0% +multi-cellular models + + + align:start position:0% +multi-cellular models +in particular the sun multicellular + + align:start position:0% +in particular the sun multicellular + + + align:start position:0% +in particular the sun multicellular +models that you get that involve + + align:start position:0% +models that you get that involve + + + align:start position:0% +models that you get that involve +sensory integration integration of + + align:start position:0% +sensory integration integration of + + + align:start position:0% +sensory integration integration of +higher levels + + align:start position:0% +higher levels + + + align:start position:0% +higher levels +and then uh + + align:start position:0% +and then uh + + + align:start position:0% +and then uh +and then mult then uh multi-organ all + + align:start position:0% +and then mult then uh multi-organ all + + + align:start position:0% +and then mult then uh multi-organ all +the way up to multi-organ systems where + + align:start position:0% +the way up to multi-organ systems where + + + align:start position:0% +the way up to multi-organ systems where +we'll take an example sort of from the + + align:start position:0% +we'll take an example sort of from the + + + align:start position:0% +we'll take an example sort of from the +atomic scale all the way up to organ + + align:start position:0% +atomic scale all the way up to organ + + + align:start position:0% +atomic scale all the way up to organ +system failure + + align:start position:0% +system failure + + + align:start position:0% +system failure +and then uh and then we'll go from there + + align:start position:0% +and then uh and then we'll go from there + + + align:start position:0% +and then uh and then we'll go from there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's start with multicellular models + + align:start position:0% +so let's start with multicellular models + + + align:start position:0% +so let's start with multicellular models +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +this is something that i + + align:start position:0% +this is something that i + + + align:start position:0% +this is something that i +today + + align:start position:0% +today + + + align:start position:0% +today +i'll show you a few slides that will + + align:start position:0% +i'll show you a few slides that will + + + align:start position:0% +i'll show you a few slides that will +remind you of the first lecture they + + align:start position:0% +remind you of the first lecture they + + + align:start position:0% +remind you of the first lecture they +either were taken from the first lecture + + align:start position:0% +either were taken from the first lecture + + + align:start position:0% +either were taken from the first lecture +in this case this is a wildly different + + align:start position:0% +in this case this is a wildly different + + + align:start position:0% +in this case this is a wildly different +author and approach and so forth but + + align:start position:0% +author and approach and so forth but + + + align:start position:0% +author and approach and so forth but +it's the same lesson as from the first + + align:start position:0% +it's the same lesson as from the first + + + align:start position:0% +it's the same lesson as from the first +lecture which is we not only have these + + align:start position:0% +lecture which is we not only have these + + + align:start position:0% +lecture which is we not only have these +exponential curves going from the 1900s + + align:start position:0% +exponential curves going from the 1900s + + + align:start position:0% +exponential curves going from the 1900s +but they're super exponential they go up + + align:start position:0% +but they're super exponential they go up + + + align:start position:0% +but they're super exponential they go up +from the trend lines you get depend on + + align:start position:0% +from the trend lines you get depend on + + + align:start position:0% +from the trend lines you get depend on +which set of points you use the steepest + + align:start position:0% +which set of points you use the steepest + + + align:start position:0% +which set of points you use the steepest +one being the most recent one 1995 + + align:start position:0% +one being the most recent one 1995 + + + align:start position:0% +one being the most recent one 1995 +and this basically is part of when it is + + align:start position:0% +and this basically is part of when it is + + + align:start position:0% +and this basically is part of when it is +that we will have computing power that + + align:start position:0% +that we will have computing power that + + + align:start position:0% +that we will have computing power that +might be on the order of + + align:start position:0% +might be on the order of + + + align:start position:0% +might be on the order of +an integrated + + align:start position:0% +an integrated + + + align:start position:0% +an integrated +human neural net we talked about neural + + align:start position:0% +human neural net we talked about neural + + + align:start position:0% +human neural net we talked about neural +nets last time kind of as a metaphor or + + align:start position:0% +nets last time kind of as a metaphor or + + + align:start position:0% +nets last time kind of as a metaphor or +as a an algorithm + + align:start position:0% +as a an algorithm + + + align:start position:0% +as a an algorithm +but + + align:start position:0% +but + + + align:start position:0% +but +when will we actually have a computer + + align:start position:0% +when will we actually have a computer + + + align:start position:0% +when will we actually have a computer +that has the capability of the human um + + align:start position:0% +that has the capability of the human um + + + align:start position:0% +that has the capability of the human um +cerebral cortex + + align:start position:0% +cerebral cortex + + + align:start position:0% +cerebral cortex +or entire integrated nervous system + + align:start position:0% +or entire integrated nervous system + + + align:start position:0% +or entire integrated nervous system +and the basis of those calculations that + + align:start position:0% +and the basis of those calculations that + + + align:start position:0% +and the basis of those calculations that +morovec made + + align:start position:0% +morovec made + + + align:start position:0% +morovec made +and and in lecture + + align:start position:0% +and and in lecture + + + align:start position:0% +and and in lecture +one kurzweil was the ex super + + align:start position:0% +one kurzweil was the ex super + + + align:start position:0% +one kurzweil was the ex super +exponential curve that i showed + + align:start position:0% +exponential curve that i showed + + + align:start position:0% +exponential curve that i showed +fourvec made them + + align:start position:0% +fourvec made them + + + align:start position:0% +fourvec made them +based on his studies on how the retina + + align:start position:0% +based on his studies on how the retina + + + align:start position:0% +based on his studies on how the retina +works + + align:start position:0% +works + + + align:start position:0% +works +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +i think + + align:start position:0% +i think + + + align:start position:0% +i think +those of you who have done a lot of + + align:start position:0% +those of you who have done a lot of + + + align:start position:0% +those of you who have done a lot of +computer programming + + align:start position:0% +computer programming + + + align:start position:0% +computer programming +uh that understanding how + + align:start position:0% +uh that understanding how + + + align:start position:0% +uh that understanding how +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the retina works is probably one of the + + align:start position:0% +the retina works is probably one of the + + + align:start position:0% +the retina works is probably one of the +more intuitive of our various human + + align:start position:0% +more intuitive of our various human + + + align:start position:0% +more intuitive of our various human +senses + + align:start position:0% +senses + + + align:start position:0% +senses +uh in the sense that you can kind of + + align:start position:0% +uh in the sense that you can kind of + + + align:start position:0% +uh in the sense that you can kind of +program an algorithm that might do in + + align:start position:0% +program an algorithm that might do in + + + align:start position:0% +program an algorithm that might do in +the lower + + align:start position:0% +the lower + + + align:start position:0% +the lower +right of slide four edge or motion + + align:start position:0% +right of slide four edge or motion + + + align:start position:0% +right of slide four edge or motion +detection you know when a a frog sees a + + align:start position:0% +detection you know when a a frog sees a + + + align:start position:0% +detection you know when a a frog sees a +fly black and white go high contrast + + align:start position:0% +fly black and white go high contrast + + + align:start position:0% +fly black and white go high contrast +zoom across his visual field + + align:start position:0% +zoom across his visual field + + + align:start position:0% +zoom across his visual field +something goes off + + align:start position:0% +something goes off + + + align:start position:0% +something goes off +and you could write an algorithm that + + align:start position:0% +and you could write an algorithm that + + + align:start position:0% +and you could write an algorithm that +could do that given a few frames of uh + + align:start position:0% +could do that given a few frames of uh + + + align:start position:0% +could do that given a few frames of uh +of any kind of format + + align:start position:0% +of any kind of format + + + align:start position:0% +of any kind of format +so anyway but but there's there's been + + align:start position:0% +so anyway but but there's there's been + + + align:start position:0% +so anyway but but there's there's been +quite a literature on this subject and + + align:start position:0% +quite a literature on this subject and + + + align:start position:0% +quite a literature on this subject and +when you go through even the best + + align:start position:0% +when you go through even the best + + + align:start position:0% +when you go through even the best +algorithms right now for doing these + + align:start position:0% +algorithms right now for doing these + + + align:start position:0% +algorithms right now for doing these +kind of calculations and you figure out + + align:start position:0% +kind of calculations and you figure out + + + align:start position:0% +kind of calculations and you figure out +how long it takes uh + + align:start position:0% +how long it takes uh + + + align:start position:0% +how long it takes uh +to do + + align:start position:0% +to do + + + align:start position:0% +to do +the retina is doing about 10 million + + align:start position:0% +the retina is doing about 10 million + + + align:start position:0% +the retina is doing about 10 million +detections per second and uh and then + + align:start position:0% +detections per second and uh and then + + + align:start position:0% +detections per second and uh and then +you scale up from that + + align:start position:0% +you scale up from that + + + align:start position:0% +you scale up from that +0.02 gram + + align:start position:0% +0.02 gram + + + align:start position:0% +0.02 gram +chunk of retina + + align:start position:0% +chunk of retina + + + align:start position:0% +chunk of retina +up to of the 1500 gram human brain and + + align:start position:0% +up to of the 1500 gram human brain and + + + align:start position:0% +up to of the 1500 gram human brain and +then you kind of get the extrapolation + + align:start position:0% +then you kind of get the extrapolation + + + align:start position:0% +then you kind of get the extrapolation +that was in the previous slide + + align:start position:0% +that was in the previous slide + + + align:start position:0% +that was in the previous slide +i think this is interesting both as an + + align:start position:0% +i think this is interesting both as an + + + align:start position:0% +i think this is interesting both as an +introduction to the kind of algorithms + + align:start position:0% +introduction to the kind of algorithms + + + align:start position:0% +introduction to the kind of algorithms +we'd like to think about when we think + + align:start position:0% +we'd like to think about when we think + + + align:start position:0% +we'd like to think about when we think +about integrating a multicellular system + + align:start position:0% +about integrating a multicellular system + + + align:start position:0% +about integrating a multicellular system +but also in terms of where the compute + + align:start position:0% +but also in terms of where the compute + + + align:start position:0% +but also in terms of where the compute +power + + align:start position:0% +power + + + align:start position:0% +power +and both biological and computational is + + align:start position:0% +and both biological and computational is + + + align:start position:0% +and both biological and computational is +going + + align:start position:0% +going + + + align:start position:0% +going +do we want to + + align:start position:0% +do we want to + + + align:start position:0% +do we want to +engineer biological systems to keep up + + align:start position:0% +engineer biological systems to keep up + + + align:start position:0% +engineer biological systems to keep up +with the copy the + + align:start position:0% +with the copy the + + + align:start position:0% +with the copy the +silicon or whatever other computational + + align:start position:0% +silicon or whatever other computational + + + align:start position:0% +silicon or whatever other computational +system we're using + + align:start position:0% +system we're using + + + align:start position:0% +system we're using +uh a decade or so from now + + align:start position:0% + + + + align:start position:0% + +now so i said that the the + + align:start position:0% +now so i said that the the + + + align:start position:0% +now so i said that the the +visual system is a relatively intuitive + + align:start position:0% +visual system is a relatively intuitive + + + align:start position:0% +visual system is a relatively intuitive +computational system to program + + align:start position:0% +computational system to program + + + align:start position:0% +computational system to program +in contrast i would say the old factory + + align:start position:0% +in contrast i would say the old factory + + + align:start position:0% +in contrast i would say the old factory +system + + align:start position:0% +system + + + align:start position:0% +system +is less intuitive at least for me + + align:start position:0% +is less intuitive at least for me + + + align:start position:0% +is less intuitive at least for me +we know now quite a bit about the + + align:start position:0% +we know now quite a bit about the + + + align:start position:0% +we know now quite a bit about the +molecular biology of the system there + + align:start position:0% +molecular biology of the system there + + + align:start position:0% +molecular biology of the system there +are a thousand receptors it's probably + + align:start position:0% +are a thousand receptors it's probably + + + align:start position:0% +are a thousand receptors it's probably +one of the largest classes + + align:start position:0% +one of the largest classes + + + align:start position:0% +one of the largest classes +of genomic repeated proteins + + align:start position:0% +of genomic repeated proteins + + + align:start position:0% +of genomic repeated proteins +and these receptors are in the same + + align:start position:0% +and these receptors are in the same + + + align:start position:0% +and these receptors are in the same +family as the receptors that are the + + align:start position:0% +family as the receptors that are the + + + align:start position:0% +family as the receptors that are the +major class of drug receptors + + align:start position:0% +major class of drug receptors + + + align:start position:0% +major class of drug receptors +protein coupled receptors + + align:start position:0% +protein coupled receptors + + + align:start position:0% +protein coupled receptors +and there is + + align:start position:0% +and there is + + + align:start position:0% +and there is +basically one receptor per cell which is + + align:start position:0% +basically one receptor per cell which is + + + align:start position:0% +basically one receptor per cell which is +quite a trick right because you got one + + align:start position:0% +quite a trick right because you got one + + + align:start position:0% +quite a trick right because you got one +receptor from mom and one for dad and + + align:start position:0% +receptor from mom and one for dad and + + + align:start position:0% +receptor from mom and one for dad and +you've got uh thousands of receptors but + + align:start position:0% +you've got uh thousands of receptors but + + + align:start position:0% +you've got uh thousands of receptors but +there's basically one per cell and they + + align:start position:0% +there's basically one per cell and they + + + align:start position:0% +there's basically one per cell and they +and they detect uh + + align:start position:0% +and they detect uh + + + align:start position:0% +and they detect uh +olfactory uh molecule concentrations + + align:start position:0% +olfactory uh molecule concentrations + + + align:start position:0% +olfactory uh molecule concentrations +uh over about seven logs + + align:start position:0% +uh over about seven logs + + + align:start position:0% +uh over about seven logs +um where the concentration thresh where + + align:start position:0% +um where the concentration thresh where + + + align:start position:0% +um where the concentration thresh where +where they can detect + + align:start position:0% +where they can detect + + + align:start position:0% +where they can detect +uh uh a concentration threshold with a + + align:start position:0% +uh uh a concentration threshold with a + + + align:start position:0% +uh uh a concentration threshold with a +particular standard deviation + + align:start position:0% +particular standard deviation + + + align:start position:0% +particular standard deviation +now this this is the beginnings of the + + align:start position:0% +now this this is the beginnings of the + + + align:start position:0% +now this this is the beginnings of the +model just stating the facts that you + + align:start position:0% +model just stating the facts that you + + + align:start position:0% +model just stating the facts that you +know about it you've got when you look + + align:start position:0% +know about it you've got when you look + + + align:start position:0% +know about it you've got when you look +at the neuroanatomy you've got + + align:start position:0% +at the neuroanatomy you've got + + + align:start position:0% +at the neuroanatomy you've got +this + + align:start position:0% +this + + + align:start position:0% +this +deodorant molecules down at the very + + align:start position:0% +deodorant molecules down at the very + + + align:start position:0% +deodorant molecules down at the very +bottom of this figure + + align:start position:0% + + + + align:start position:0% + +cilia olfactory neurons which is a + + align:start position:0% +cilia olfactory neurons which is a + + + align:start position:0% +cilia olfactory neurons which is a +primary uh signal transduction this then + + align:start position:0% +primary uh signal transduction this then + + + align:start position:0% +primary uh signal transduction this then +goes up where it's integrated + + align:start position:0% +goes up where it's integrated + + + align:start position:0% +goes up where it's integrated +in the glomeruli and you can think of + + align:start position:0% +in the glomeruli and you can think of + + + align:start position:0% +in the glomeruli and you can think of +this sort of like the neural nets we + + align:start position:0% +this sort of like the neural nets we + + + align:start position:0% +this sort of like the neural nets we +were talking about last time where you + + align:start position:0% +were talking about last time where you + + + align:start position:0% +were talking about last time where you +had these + + align:start position:0% +had these + + + align:start position:0% +had these +interneurons you had the the + + align:start position:0% +interneurons you had the the + + + align:start position:0% +interneurons you had the the +extra layer that we showed was so + + align:start position:0% +extra layer that we showed was so + + + align:start position:0% +extra layer that we showed was so +important + + align:start position:0% + + + + align:start position:0% + +and the thing that's amazing about this + + align:start position:0% +and the thing that's amazing about this + + + align:start position:0% +and the thing that's amazing about this +system are are + + align:start position:0% +system are are + + + align:start position:0% +system are are +lodged in these + + align:start position:0% +lodged in these + + + align:start position:0% +lodged in these +four basic olfactory facts which i take + + align:start position:0% +four basic olfactory facts which i take + + + align:start position:0% +four basic olfactory facts which i take +from hotfield's uh + + align:start position:0% +from hotfield's uh + + + align:start position:0% +from hotfield's uh +work which is really just like this is + + align:start position:0% +work which is really just like this is + + + align:start position:0% +work which is really just like this is +the same hot field that introduced us to + + align:start position:0% +the same hot field that introduced us to + + + align:start position:0% +the same hot field that introduced us to +neuro or really + + align:start position:0% +neuro or really + + + align:start position:0% +neuro or really +champion the concept of neural nets as a + + align:start position:0% +champion the concept of neural nets as a + + + align:start position:0% +champion the concept of neural nets as a +computational algorithmic metaphor + + align:start position:0% +computational algorithmic metaphor + + + align:start position:0% +computational algorithmic metaphor +and here + + align:start position:0% +and here + + + align:start position:0% +and here +the idea is + + align:start position:0% +the idea is + + + align:start position:0% +the idea is +you have odor and memory recognition + + align:start position:0% +you have odor and memory recognition + + + align:start position:0% +you have odor and memory recognition +you have background elimination + + align:start position:0% +you have background elimination + + + align:start position:0% +you have background elimination +as just like + + align:start position:0% +as just like + + + align:start position:0% +as just like +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know how your eyes adapt to a mostly + + align:start position:0% +you know how your eyes adapt to a mostly + + + align:start position:0% +you know how your eyes adapt to a mostly +red room your your nose is great your + + align:start position:0% +red room your your nose is great your + + + align:start position:0% +red room your your nose is great your +your whole factory system is great at + + align:start position:0% +your whole factory system is great at + + + align:start position:0% +your whole factory system is great at +adapting to uh background + + align:start position:0% +adapting to uh background + + + align:start position:0% +adapting to uh background +odorants so you have one + + align:start position:0% +odorants so you have one + + + align:start position:0% +odorants so you have one +known and one unknown thoroughly mixed + + align:start position:0% +known and one unknown thoroughly mixed + + + align:start position:0% +known and one unknown thoroughly mixed +number three you can have component + + align:start position:0% +number three you can have component + + + align:start position:0% +number three you can have component +separation you can have a few different + + align:start position:0% +separation you can have a few different + + + align:start position:0% +separation you can have a few different +odors at once + + align:start position:0% +odors at once + + + align:start position:0% +odors at once +you have odor + + align:start position:0% +you have odor + + + align:start position:0% +you have odor +separation where you have + + align:start position:0% + + + + align:start position:0% + +unknowns + + align:start position:0% +unknowns + + + align:start position:0% +unknowns +and each of these tasks + + align:start position:0% +and each of these tasks + + + align:start position:0% +and each of these tasks +i mean + + align:start position:0% + + + + align:start position:0% + +the combination of these is quite + + align:start position:0% +the combination of these is quite + + + align:start position:0% +the combination of these is quite +remarkable so the basis of the model + + align:start position:0% +remarkable so the basis of the model + + + align:start position:0% +remarkable so the basis of the model +that hotfield has proposed + + align:start position:0% +that hotfield has proposed + + + align:start position:0% +that hotfield has proposed +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +is + + align:start position:0% +is + + + align:start position:0% +is +is this you have a coverage + + align:start position:0% +is this you have a coverage + + + align:start position:0% +is this you have a coverage +for each of the i receptors where i goes + + align:start position:0% +for each of the i receptors where i goes + + + align:start position:0% +for each of the i receptors where i goes +from one to a thousand this will vary + + align:start position:0% +from one to a thousand this will vary + + + align:start position:0% +from one to a thousand this will vary +depending on the organism mice have + + align:start position:0% +depending on the organism mice have + + + align:start position:0% +depending on the organism mice have +twice as many as we do probably so on + + align:start position:0% +twice as many as we do probably so on + + + align:start position:0% +twice as many as we do probably so on +but the coverage of each the of each of + + align:start position:0% +but the coverage of each the of each of + + + align:start position:0% +but the coverage of each the of each of +those receptors + + align:start position:0% + + + + align:start position:0% + +is equal to the minimum coverage + + align:start position:0% +is equal to the minimum coverage + + + align:start position:0% +is equal to the minimum coverage +um + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +for the concentration of the target + + align:start position:0% +for the concentration of the target + + + align:start position:0% +for the concentration of the target +where the say the target is the target + + align:start position:0% +where the say the target is the target + + + align:start position:0% +where the say the target is the target +odorant that you're looking for + + align:start position:0% +odorant that you're looking for + + + align:start position:0% +odorant that you're looking for +over the + + align:start position:0% +over the + + + align:start position:0% +over the +concentration that's the threshold for + + align:start position:0% +concentration that's the threshold for + + + align:start position:0% +concentration that's the threshold for +firing that neuron for that target + + align:start position:0% +firing that neuron for that target + + + align:start position:0% +firing that neuron for that target +threshold of t + + align:start position:0% +threshold of t + + + align:start position:0% +threshold of t +then you multiply that times either one + + align:start position:0% +then you multiply that times either one + + + align:start position:0% +then you multiply that times either one +or some fraction it's one if you really + + align:start position:0% +or some fraction it's one if you really + + + align:start position:0% +or some fraction it's one if you really +hit the target + + align:start position:0% +hit the target + + + align:start position:0% +hit the target +and it's + + align:start position:0% +and it's + + + align:start position:0% +and it's +this fraction of for that particular + + align:start position:0% +this fraction of for that particular + + + align:start position:0% +this fraction of for that particular +receptor and that particular target + + align:start position:0% +receptor and that particular target + + + align:start position:0% +receptor and that particular target +you've got some crosstalk and the amount + + align:start position:0% +you've got some crosstalk and the amount + + + align:start position:0% +you've got some crosstalk and the amount +of crosstalk + + align:start position:0% +of crosstalk + + + align:start position:0% +of crosstalk +uh you can think of this as a field of + + align:start position:0% +uh you can think of this as a field of + + + align:start position:0% +uh you can think of this as a field of +receptors which are all uh + + align:start position:0% +receptors which are all uh + + + align:start position:0% +receptors which are all uh +um + + align:start position:0% +um + + + align:start position:0% +um +have variable binding and that binding + + align:start position:0% +have variable binding and that binding + + + align:start position:0% +have variable binding and that binding +is over these seven six or seven logs + + align:start position:0% +is over these seven six or seven logs + + + align:start position:0% +is over these seven six or seven logs +here + + align:start position:0% +here + + + align:start position:0% +here +um and that's this just reflects that + + align:start position:0% +um and that's this just reflects that + + + align:start position:0% +um and that's this just reflects that +same thing that we were talking about + + align:start position:0% +same thing that we were talking about + + + align:start position:0% +same thing that we were talking about +and then + + align:start position:0% +and then + + + align:start position:0% +and then +so that so the the total + + align:start position:0% +so that so the the total + + + align:start position:0% +so that so the the total +uh number of inputs going to the next + + align:start position:0% +uh number of inputs going to the next + + + align:start position:0% +uh number of inputs going to the next +layer in the neural net the coverage + + align:start position:0% +layer in the neural net the coverage + + + align:start position:0% +layer in the neural net the coverage +here is me the sum of this + + align:start position:0% +here is me the sum of this + + + align:start position:0% +here is me the sum of this +of this target + + align:start position:0% +of this target + + + align:start position:0% +of this target +signal + + align:start position:0% +signal + + + align:start position:0% +signal +plus + + align:start position:0% +plus + + + align:start position:0% +plus +the background signal so the first term + + align:start position:0% +the background signal so the first term + + + align:start position:0% +the background signal so the first term +is target and the right hand term is the + + align:start position:0% +is target and the right hand term is the + + + align:start position:0% +is target and the right hand term is the +background as you can see they have the + + align:start position:0% +background as you can see they have the + + + align:start position:0% +background as you can see they have the +same form the same threshold and + + align:start position:0% +same form the same threshold and + + + align:start position:0% +same form the same threshold and +concentration c sub b is concentration + + align:start position:0% +concentration c sub b is concentration + + + align:start position:0% +concentration c sub b is concentration +background + + align:start position:0% +background + + + align:start position:0% +background +and then + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +so let's see how this plays out when you + + align:start position:0% +so let's see how this plays out when you + + + align:start position:0% +so let's see how this plays out when you +actually + + align:start position:0% +actually + + + align:start position:0% +actually +try this out + + align:start position:0% +try this out + + + align:start position:0% +try this out +in a olfactory processing problem here + + align:start position:0% +in a olfactory processing problem here + + + align:start position:0% +in a olfactory processing problem here +you have + + align:start position:0% +you have + + + align:start position:0% +you have +outer space + + align:start position:0% +outer space + + + align:start position:0% +outer space +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +what what you have here is + + align:start position:0% +what what you have here is + + + align:start position:0% +what what you have here is +80 different neurons is the y-axis at + + align:start position:0% +80 different neurons is the y-axis at + + + align:start position:0% +80 different neurons is the y-axis at +the top of slide seven + + align:start position:0% +the top of slide seven + + + align:start position:0% +the top of slide seven +and then across the bottom uh sorry + + align:start position:0% +and then across the bottom uh sorry + + + align:start position:0% +and then across the bottom uh sorry +across + + align:start position:0% +across + + + align:start position:0% +across +the x-axis is time in milliseconds going + + align:start position:0% +the x-axis is time in milliseconds going + + + align:start position:0% +the x-axis is time in milliseconds going +from zero to 800 milliseconds and this + + align:start position:0% +from zero to 800 milliseconds and this + + + align:start position:0% +from zero to 800 milliseconds and this +is all uh modeled on + + align:start position:0% +is all uh modeled on + + + align:start position:0% +is all uh modeled on +on fairly realistic parameters + + align:start position:0% +on fairly realistic parameters + + + align:start position:0% +on fairly realistic parameters +based on experiments + + align:start position:0% +based on experiments + + + align:start position:0% +based on experiments +and so what you have here is 80 adapting + + align:start position:0% +and so what you have here is 80 adapting + + + align:start position:0% +and so what you have here is 80 adapting +neurons + + align:start position:0% +neurons + + + align:start position:0% +neurons +and what you're doing is two sniffs of a + + align:start position:0% +and what you're doing is two sniffs of a + + + align:start position:0% +and what you're doing is two sniffs of a +mixed odor that's what this is modeling + + align:start position:0% +mixed odor that's what this is modeling + + + align:start position:0% +mixed odor that's what this is modeling +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh + + align:start position:0% +uh + + + align:start position:0% +uh +first you have a 100 to 500 milliseconds + + align:start position:0% +first you have a 100 to 500 milliseconds + + + align:start position:0% +first you have a 100 to 500 milliseconds +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the the range from so so you have + + align:start position:0% +the the range from so so you have + + + align:start position:0% +the the range from so so you have +you can see that something's happening + + align:start position:0% +you can see that something's happening + + + align:start position:0% +you can see that something's happening +at 100 milliseconds and up to 500 you + + align:start position:0% +at 100 milliseconds and up to 500 you + + + align:start position:0% +at 100 milliseconds and up to 500 you +have a mixed odor which is 50 parts of x + + align:start position:0% +have a mixed odor which is 50 parts of x + + + align:start position:0% +have a mixed odor which is 50 parts of x +plus a thousand parts of y + + align:start position:0% +plus a thousand parts of y + + + align:start position:0% +plus a thousand parts of y +per thousand times uh y + + align:start position:0% +per thousand times uh y + + + align:start position:0% +per thousand times uh y +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and then at 500 milliseconds you change + + align:start position:0% +and then at 500 milliseconds you change + + + align:start position:0% +and then at 500 milliseconds you change +this this ratio very slightly you see + + align:start position:0% +this this ratio very slightly you see + + + align:start position:0% +this this ratio very slightly you see +just uh up x by 75 and y up to from a + + align:start position:0% +just uh up x by 75 and y up to from a + + + align:start position:0% +just uh up x by 75 and y up to from a +thousand to eleven hundred + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's the paradigm + + align:start position:0% +so that's the paradigm + + + align:start position:0% +so that's the paradigm +fifty a thousand to seventy five and + + align:start position:0% +fifty a thousand to seventy five and + + + align:start position:0% +fifty a thousand to seventy five and +eleven hundred and then sniff at a + + align:start position:0% +eleven hundred and then sniff at a + + + align:start position:0% +eleven hundred and then sniff at a +hundred milliseconds that that + + align:start position:0% +hundred milliseconds that that + + + align:start position:0% +hundred milliseconds that that +that first one that mixed odor + + align:start position:0% +that first one that mixed odor + + + align:start position:0% +that first one that mixed odor +um + + align:start position:0% +um + + + align:start position:0% +um +it activates more than half the neurons + + align:start position:0% +it activates more than half the neurons + + + align:start position:0% +it activates more than half the neurons +so this is not like your retina where if + + align:start position:0% +so this is not like your retina where if + + + align:start position:0% +so this is not like your retina where if +you have a single point source it'll + + align:start position:0% +you have a single point source it'll + + + align:start position:0% +you have a single point source it'll +activate that one + + align:start position:0% +activate that one + + + align:start position:0% +activate that one +uh + + align:start position:0% +uh + + + align:start position:0% +uh +rod cell or maybe a cinder surround uh + + align:start position:0% +rod cell or maybe a cinder surround uh + + + align:start position:0% +rod cell or maybe a cinder surround uh +sort of effect + + align:start position:0% +sort of effect + + + align:start position:0% +sort of effect +but it's really activating half of the + + align:start position:0% +but it's really activating half of the + + + align:start position:0% +but it's really activating half of the +neurons okay + + align:start position:0% +neurons okay + + + align:start position:0% +neurons okay +and then the change smith at 500 + + align:start position:0% +and then the change smith at 500 + + + align:start position:0% +and then the change smith at 500 +milliseconds remember just these two + + align:start position:0% +milliseconds remember just these two + + + align:start position:0% +milliseconds remember just these two +small changes + + align:start position:0% +small changes + + + align:start position:0% +small changes +is almost invisible + + align:start position:0% +is almost invisible + + + align:start position:0% +is almost invisible +right + + align:start position:0% +right + + + align:start position:0% +right +so + + align:start position:0% +so + + + align:start position:0% +so +that's what you're seeing uh + + align:start position:0% +that's what you're seeing uh + + + align:start position:0% +that's what you're seeing uh +right here okay + + align:start position:0% +right here okay + + + align:start position:0% +right here okay +is this this huge this huge swamping + + align:start position:0% +is this this huge this huge swamping + + + align:start position:0% +is this this huge this huge swamping +amount + + align:start position:0% +amount + + + align:start position:0% +amount +but then + + align:start position:0% +but then + + + align:start position:0% +but then +in in b so that that's what happened in + + align:start position:0% +in in b so that that's what happened in + + + align:start position:0% +in in b so that that's what happened in +a b + + align:start position:0% +a b + + + align:start position:0% +a b +you've now uh + + align:start position:0% +you've now uh + + + align:start position:0% +you've now uh +plotting instead of + + align:start position:0% +plotting instead of + + + align:start position:0% +plotting instead of +individual neurons you're doing the + + align:start position:0% +individual neurons you're doing the + + + align:start position:0% +individual neurons you're doing the +instantaneous rate in hertz + + align:start position:0% +instantaneous rate in hertz + + + align:start position:0% +instantaneous rate in hertz +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and now + + align:start position:0% +and now + + + align:start position:0% +and now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh when you could you can see the sixth + + align:start position:0% +uh when you could you can see the sixth + + + align:start position:0% +uh when you could you can see the sixth +second smith here as the as at the 500 + + align:start position:0% +second smith here as the as at the 500 + + + align:start position:0% +second smith here as the as at the 500 +milliseconds which even though you + + align:start position:0% +milliseconds which even though you + + + align:start position:0% +milliseconds which even though you +really can't see it in the corresponding + + align:start position:0% +really can't see it in the corresponding + + + align:start position:0% +really can't see it in the corresponding +point where you're looking at all these + + align:start position:0% +point where you're looking at all these + + + align:start position:0% +point where you're looking at all these +individual neurons + + align:start position:0% +individual neurons + + + align:start position:0% +individual neurons +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +so you can see that even a 20 + + align:start position:0% +so you can see that even a 20 + + + align:start position:0% +so you can see that even a 20 +spread + + align:start position:0% +spread + + + align:start position:0% +spread +in the in one of these parameters is + + align:start position:0% +in the in one of these parameters is + + + align:start position:0% +in the in one of these parameters is +enough to uh to get this kind of uh + + align:start position:0% +enough to uh to get this kind of uh + + + align:start position:0% +enough to uh to get this kind of uh +easily detectable signal + + align:start position:0% +easily detectable signal + + + align:start position:0% +easily detectable signal +now that's the example of a simulation + + align:start position:0% +now that's the example of a simulation + + + align:start position:0% +now that's the example of a simulation +that's not a simulation a particular + + align:start position:0% +that's not a simulation a particular + + + align:start position:0% +that's not a simulation a particular +experimental data set but it's based on + + align:start position:0% +experimental data set but it's based on + + + align:start position:0% +experimental data set but it's based on +experimental data sets and the code this + + align:start position:0% +experimental data sets and the code this + + + align:start position:0% +experimental data sets and the code this +is not mathematica this is map lab which + + align:start position:0% +is not mathematica this is map lab which + + + align:start position:0% +is not mathematica this is map lab which +we almost we could have interchangeably + + align:start position:0% +we almost we could have interchangeably + + + align:start position:0% +we almost we could have interchangeably +taught in this course and you can see + + align:start position:0% +taught in this course and you can see + + + align:start position:0% +taught in this course and you can see +here in green are the comments and you + + align:start position:0% +here in green are the comments and you + + + align:start position:0% +here in green are the comments and you +can see some of the things that we've + + align:start position:0% +can see some of the things that we've + + + align:start position:0% +can see some of the things that we've +been talking about here + + align:start position:0% +been talking about here + + + align:start position:0% +been talking about here +the the + + align:start position:0% +the the + + + align:start position:0% +the the +the number of receptor types is actually + + align:start position:0% +the number of receptor types is actually + + + align:start position:0% +the number of receptor types is actually +here two thousand one thousand you see + + align:start position:0% +here two thousand one thousand you see + + + align:start position:0% +here two thousand one thousand you see +the the target remember i said could be + + align:start position:0% +the the target remember i said could be + + + align:start position:0% +the the target remember i said could be +some random number that that goes over + + align:start position:0% +some random number that that goes over + + + align:start position:0% +some random number that that goes over +six logarithms well the way that's done + + align:start position:0% +six logarithms well the way that's done + + + align:start position:0% +six logarithms well the way that's done +here is here's a random number generated + + align:start position:0% +here is here's a random number generated + + + align:start position:0% +here is here's a random number generated +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and and you you generate as the log of + + align:start position:0% +and and you you generate as the log of + + + align:start position:0% +and and you you generate as the log of +the target and then you get the target + + align:start position:0% +the target and then you get the target + + + align:start position:0% +the target and then you get the target +by taking the exponential it's very + + align:start position:0% +by taking the exponential it's very + + + align:start position:0% +by taking the exponential it's very +straightforward + + align:start position:0% +straightforward + + + align:start position:0% +straightforward +and the code goes on from there + + align:start position:0% +and the code goes on from there + + + align:start position:0% +and the code goes on from there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now this brings us to a very interesting + + align:start position:0% +now this brings us to a very interesting + + + align:start position:0% +now this brings us to a very interesting +point um + + align:start position:0% +point um + + + align:start position:0% +point um +since these three lectures on networks + + align:start position:0% +since these three lectures on networks + + + align:start position:0% +since these three lectures on networks +and in a certain sense the whole course + + align:start position:0% +and in a certain sense the whole course + + + align:start position:0% +and in a certain sense the whole course +is building for + + align:start position:0% +is building for + + + align:start position:0% +is building for +systems biology network models + + align:start position:0% +systems biology network models + + + align:start position:0% +systems biology network models +and for these models be useful in the + + align:start position:0% +and for these models be useful in the + + + align:start position:0% +and for these models be useful in the +same sense that the models we had for + + align:start position:0% +same sense that the models we had for + + + align:start position:0% +same sense that the models we had for +x-ray crystallography and the models + + align:start position:0% +x-ray crystallography and the models + + + align:start position:0% +x-ray crystallography and the models +we've had for + + align:start position:0% +we've had for + + + align:start position:0% +we've had for +genome interpretation in terms of + + align:start position:0% +genome interpretation in terms of + + + align:start position:0% +genome interpretation in terms of +homology and sequence + + align:start position:0% +homology and sequence + + + align:start position:0% +homology and sequence +folding and so forth + + align:start position:0% +folding and so forth + + + align:start position:0% +folding and so forth +needed to be shared it's the mock the + + align:start position:0% +needed to be shared it's the mock the + + + align:start position:0% +needed to be shared it's the mock the +models even more than the data need to + + align:start position:0% +models even more than the data need to + + + align:start position:0% +models even more than the data need to +be shareable because in a certain sense + + align:start position:0% +be shareable because in a certain sense + + + align:start position:0% +be shareable because in a certain sense +uh + + align:start position:0% +uh + + + align:start position:0% +uh +even modest manipulation of the data + + align:start position:0% +even modest manipulation of the data + + + align:start position:0% +even modest manipulation of the data +involves some usually involves some good + + align:start position:0% +involves some usually involves some good + + + align:start position:0% +involves some usually involves some good +model behind it and so these are some of + + align:start position:0% +model behind it and so these are some of + + + align:start position:0% +model behind it and so these are some of +the work groups that are working on + + align:start position:0% +the work groups that are working on + + + align:start position:0% +the work groups that are working on +uh different modeling schemes in + + align:start position:0% +uh different modeling schemes in + + + align:start position:0% +uh different modeling schemes in +particular i should point out the the + + align:start position:0% +particular i should point out the the + + + align:start position:0% +particular i should point out the the +biospice is now darpa biospice and svml + + align:start position:0% +biospice is now darpa biospice and svml + + + align:start position:0% +biospice is now darpa biospice and svml +is kind of a growing part of that system + + align:start position:0% +is kind of a growing part of that system + + + align:start position:0% +is kind of a growing part of that system +biology markup language is a way of + + align:start position:0% +biology markup language is a way of + + + align:start position:0% +biology markup language is a way of +sharing this data + + align:start position:0% +sharing this data + + + align:start position:0% +sharing this data +and + + align:start position:0% +and + + + align:start position:0% +and +as yet there's not the kind of + + align:start position:0% +as yet there's not the kind of + + + align:start position:0% +as yet there's not the kind of +convention that we have in + + align:start position:0% +convention that we have in + + + align:start position:0% +convention that we have in +crystallography and dna sequencing where + + align:start position:0% +crystallography and dna sequencing where + + + align:start position:0% +crystallography and dna sequencing where +you submit at the time that you publish + + align:start position:0% +you submit at the time that you publish + + + align:start position:0% +you submit at the time that you publish +a paper you submit + + align:start position:0% +a paper you submit + + + align:start position:0% +a paper you submit +your data and model data slash model + + align:start position:0% +your data and model data slash model + + + align:start position:0% +your data and model data slash model +with an accession number to the database + + align:start position:0% +with an accession number to the database + + + align:start position:0% +with an accession number to the database +or else you don't get it published we're + + align:start position:0% +or else you don't get it published we're + + + align:start position:0% +or else you don't get it published we're +nowhere near that now for the rest of + + align:start position:0% +nowhere near that now for the rest of + + + align:start position:0% +nowhere near that now for the rest of +biology but these kind of efforts + + align:start position:0% +biology but these kind of efforts + + + align:start position:0% +biology but these kind of efforts +probably are moving in that direction + + align:start position:0% +probably are moving in that direction + + + align:start position:0% +probably are moving in that direction +and you can see that that the features + + align:start position:0% +and you can see that that the features + + + align:start position:0% +and you can see that that the features +of each of these + + align:start position:0% +of each of these + + + align:start position:0% +of each of these +are some of the things that we've been + + align:start position:0% +are some of the things that we've been + + + align:start position:0% +are some of the things that we've been +talking about before you've got + + align:start position:0% +talking about before you've got + + + align:start position:0% +talking about before you've got +stochastic modeling + + align:start position:0% +stochastic modeling + + + align:start position:0% +stochastic modeling +kinetic modeling enzyme receptor + + align:start position:0% +kinetic modeling enzyme receptor + + + align:start position:0% +kinetic modeling enzyme receptor +sort of cell geometry + + align:start position:0% + + + + align:start position:0% + +neural nets + + align:start position:0% +neural nets + + + align:start position:0% +neural nets +and so on + + align:start position:0% + + + + align:start position:0% + +this is by no means comprehensive and + + align:start position:0% +this is by no means comprehensive and + + + align:start position:0% +this is by no means comprehensive and +their hypertext links here if you really + + align:start position:0% +their hypertext links here if you really + + + align:start position:0% +their hypertext links here if you really +want to dig into them and some of the + + align:start position:0% +want to dig into them and some of the + + + align:start position:0% +want to dig into them and some of the +platforms that they've been thinking + + align:start position:0% +platforms that they've been thinking + + + align:start position:0% +platforms that they've been thinking +about different + + align:start position:0% +about different + + + align:start position:0% +about different +different ways of making it slightly + + align:start position:0% +different ways of making it slightly + + + align:start position:0% +different ways of making it slightly +less system dependent everyone has you + + align:start position:0% +less system dependent everyone has you + + + align:start position:0% +less system dependent everyone has you +know their attempts obviously windows is + + align:start position:0% +know their attempts obviously windows is + + + align:start position:0% +know their attempts obviously windows is +not system independent + + align:start position:0% +not system independent + + + align:start position:0% +not system independent +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +two very brief examples of multicellular + + align:start position:0% +two very brief examples of multicellular + + + align:start position:0% +two very brief examples of multicellular +models + + align:start position:0% + + + + align:start position:0% + +both of them being neural models kind of + + align:start position:0% +both of them being neural models kind of + + + align:start position:0% +both of them being neural models kind of +building from what we were thinking + + align:start position:0% +building from what we were thinking + + + align:start position:0% +building from what we were thinking +about last time but now we're going to a + + align:start position:0% +about last time but now we're going to a + + + align:start position:0% +about last time but now we're going to a +completely different kind of + + align:start position:0% +completely different kind of + + + align:start position:0% +completely different kind of +multicellular model all the way up from + + align:start position:0% +multicellular model all the way up from + + + align:start position:0% +multicellular model all the way up from +sort of individual + + align:start position:0% +sort of individual + + + align:start position:0% +sort of individual +effects that a single nucleotide how + + align:start position:0% +effects that a single nucleotide how + + + align:start position:0% +effects that a single nucleotide how +much effect the single nucleotide can + + align:start position:0% +much effect the single nucleotide can + + + align:start position:0% +much effect the single nucleotide can +have on a whole organ system + + align:start position:0% +have on a whole organ system + + + align:start position:0% +have on a whole organ system +which in this case will be + + align:start position:0% +which in this case will be + + + align:start position:0% +which in this case will be +cardiovascular + + align:start position:0% +cardiovascular + + + align:start position:0% +cardiovascular +so we go from + + align:start position:0% + + + + align:start position:0% + +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +there are a number of physiom and + + align:start position:0% +there are a number of physiom and + + + align:start position:0% +there are a number of physiom and +cardiom projects uh that are + + align:start position:0% +cardiom projects uh that are + + + align:start position:0% +cardiom projects uh that are +of active interest + + align:start position:0% +of active interest + + + align:start position:0% +of active interest +these + + align:start position:0% +these + + + align:start position:0% +these +uh + + align:start position:0% +uh + + + align:start position:0% +uh +just like the previous slides that i + + align:start position:0% +just like the previous slides that i + + + align:start position:0% +just like the previous slides that i +showed showing all the ways of sharing + + align:start position:0% +showed showing all the ways of sharing + + + align:start position:0% +showed showing all the ways of sharing +system models many of these efforts + + align:start position:0% +system models many of these efforts + + + align:start position:0% +system models many of these efforts +are kind of loose consortium alliances + + align:start position:0% +are kind of loose consortium alliances + + + align:start position:0% +are kind of loose consortium alliances +where people have + + align:start position:0% +where people have + + + align:start position:0% +where people have +put together different models either + + align:start position:0% +put together different models either + + + align:start position:0% +put together different models either +deal with the + + align:start position:0% +deal with the + + + align:start position:0% +deal with the +anatomy + + align:start position:0% +anatomy + + + align:start position:0% +anatomy +physiology or sometimes + + align:start position:0% +physiology or sometimes + + + align:start position:0% +physiology or sometimes +a + + align:start position:0% +a + + + align:start position:0% +a +integration of + + align:start position:0% +integration of + + + align:start position:0% +integration of +molecular to cellular cellular to + + align:start position:0% +molecular to cellular cellular to + + + align:start position:0% +molecular to cellular cellular to +say neural or muscular and all the way + + align:start position:0% +say neural or muscular and all the way + + + align:start position:0% +say neural or muscular and all the way +up to + + align:start position:0% +up to + + + align:start position:0% +up to +fluid dynamics and so on + + align:start position:0% + + + + align:start position:0% + +so let's start with a single base pair + + align:start position:0% +so let's start with a single base pair + + + align:start position:0% +so let's start with a single base pair +change + + align:start position:0% +change + + + align:start position:0% +change +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +i start with this one because you should + + align:start position:0% +i start with this one because you should + + + align:start position:0% +i start with this one because you should +feel comfortable with it at this point + + align:start position:0% +feel comfortable with it at this point + + + align:start position:0% +feel comfortable with it at this point +we mentioned it briefly before + + align:start position:0% +we mentioned it briefly before + + + align:start position:0% +we mentioned it briefly before +we'll talk about it in more detail now + + align:start position:0% +we'll talk about it in more detail now + + + align:start position:0% +we'll talk about it in more detail now +this is the single nucleotide + + align:start position:0% +this is the single nucleotide + + + align:start position:0% +this is the single nucleotide +polymorphism which causes the change + + align:start position:0% +polymorphism which causes the change + + + align:start position:0% +polymorphism which causes the change +of the beta subunit of hemoglobin which + + align:start position:0% +of the beta subunit of hemoglobin which + + + align:start position:0% +of the beta subunit of hemoglobin which +is a tetramer to go + + align:start position:0% +is a tetramer to go + + + align:start position:0% +is a tetramer to go +from + + align:start position:0% +from + + + align:start position:0% +from +a + + align:start position:0% +a + + + align:start position:0% +a +glutamate + + align:start position:0% +glutamate + + + align:start position:0% +glutamate +normally in most people at position six + + align:start position:0% +normally in most people at position six + + + align:start position:0% +normally in most people at position six +of the beta chain to availing + + align:start position:0% +of the beta chain to availing + + + align:start position:0% +of the beta chain to availing +or so that's the the purple + + align:start position:0% +or so that's the the purple + + + align:start position:0% +or so that's the the purple +set of tetramers or to tryptophan that's + + align:start position:0% +set of tetramers or to tryptophan that's + + + align:start position:0% +set of tetramers or to tryptophan that's +the cyan set on the far right + + align:start position:0% +the cyan set on the far right + + + align:start position:0% +the cyan set on the far right +and + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +from combinations of x-ray + + align:start position:0% +from combinations of x-ray + + + align:start position:0% +from combinations of x-ray +crystallography and three-dimensional + + align:start position:0% +crystallography and three-dimensional + + + align:start position:0% +crystallography and three-dimensional +modeling and this is not speculation + + align:start position:0% +modeling and this is not speculation + + + align:start position:0% +modeling and this is not speculation +just based on primary sequence data even + + align:start position:0% +just based on primary sequence data even + + + align:start position:0% +just based on primary sequence data even +though the primary sequence here is very + + align:start position:0% +though the primary sequence here is very + + + align:start position:0% +though the primary sequence here is very +very close just a single nucleotide a + + align:start position:0% +very close just a single nucleotide a + + + align:start position:0% +very close just a single nucleotide a +single amino acid change nevertheless + + align:start position:0% +single amino acid change nevertheless + + + align:start position:0% +single amino acid change nevertheless +these authors have been building this + + align:start position:0% +these authors have been building this + + + align:start position:0% +these authors have been building this +from + + align:start position:0% +from + + + align:start position:0% +from +uh the crystallographic data where not + + align:start position:0% +uh the crystallographic data where not + + + align:start position:0% +uh the crystallographic data where not +only do you care about the tetramer + + align:start position:0% +only do you care about the tetramer + + + align:start position:0% +only do you care about the tetramer +itself but how the tetramers interact + + align:start position:0% +itself but how the tetramers interact + + + align:start position:0% +itself but how the tetramers interact +with one another to make these long + + align:start position:0% +with one another to make these long + + + align:start position:0% +with one another to make these long +fibrous chains which are + + align:start position:0% +fibrous chains which are + + + align:start position:0% +fibrous chains which are +considerably more stable + + align:start position:0% +considerably more stable + + + align:start position:0% +considerably more stable +in the sickle cell and what you see here + + align:start position:0% +in the sickle cell and what you see here + + + align:start position:0% +in the sickle cell and what you see here +is + + align:start position:0% +is + + + align:start position:0% +is +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +the + + align:start position:0% +the + + + align:start position:0% +the +the valine substitution is locked in one + + align:start position:0% +the valine substitution is locked in one + + + align:start position:0% +the valine substitution is locked in one +kind of conformation and the + + align:start position:0% +kind of conformation and the + + + align:start position:0% +kind of conformation and the +tryptophan and another and you can see + + align:start position:0% +tryptophan and another and you can see + + + align:start position:0% +tryptophan and another and you can see +how + + align:start position:0% +how + + + align:start position:0% +how +these authors have have + + align:start position:0% +these authors have have + + + align:start position:0% +these authors have have +decided how a potential fiber can form + + align:start position:0% +decided how a potential fiber can form + + + align:start position:0% +decided how a potential fiber can form +in the different cases + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now those fibers + + align:start position:0% +now those fibers + + + align:start position:0% +now those fibers +in one way or another which is not + + align:start position:0% +in one way or another which is not + + + align:start position:0% +in one way or another which is not +totally mapped out + + align:start position:0% +totally mapped out + + + align:start position:0% +totally mapped out +but you uh + + align:start position:0% +but you uh + + + align:start position:0% +but you uh +affect the efficiency of uh + + align:start position:0% +affect the efficiency of uh + + + align:start position:0% +affect the efficiency of uh +of the hemoglobin slightly and this in + + align:start position:0% +of the hemoglobin slightly and this in + + + align:start position:0% +of the hemoglobin slightly and this in +the shape of the cell much more + + align:start position:0% +the shape of the cell much more + + + align:start position:0% +the shape of the cell much more +radically + + align:start position:0% +radically + + + align:start position:0% +radically +and + + align:start position:0% +and + + + align:start position:0% +and +this combination uh results in the in + + align:start position:0% +this combination uh results in the in + + + align:start position:0% +this combination uh results in the in +this in the cell especially under any + + align:start position:0% +this in the cell especially under any + + + align:start position:0% +this in the cell especially under any +kind of stress either oxidative or other + + align:start position:0% +kind of stress either oxidative or other + + + align:start position:0% +kind of stress either oxidative or other +metabolic stress becoming sickled so you + + align:start position:0% +metabolic stress becoming sickled so you + + + align:start position:0% +metabolic stress becoming sickled so you +can have a + + align:start position:0% +can have a + + + align:start position:0% +can have a +a combination of cells which have + + align:start position:0% +a combination of cells which have + + + align:start position:0% +a combination of cells which have +varying degrees of sickling here in uh + + align:start position:0% +varying degrees of sickling here in uh + + + align:start position:0% +varying degrees of sickling here in uh +in this + + align:start position:0% + + + + align:start position:0% + +this microscopic slide on the left you + + align:start position:0% +this microscopic slide on the left you + + + align:start position:0% +this microscopic slide on the left you +have both the sickle cell and the normal + + align:start position:0% +have both the sickle cell and the normal + + + align:start position:0% +have both the sickle cell and the normal +cell side by side + + align:start position:0% +cell side by side + + + align:start position:0% +cell side by side +i think when we built up the red blood + + align:start position:0% +i think when we built up the red blood + + + align:start position:0% +i think when we built up the red blood +cell metabolic model we talked about + + align:start position:0% +cell metabolic model we talked about + + + align:start position:0% +cell metabolic model we talked about +some of the non-metabolic considerations + + align:start position:0% +some of the non-metabolic considerations + + + align:start position:0% +some of the non-metabolic considerations +of that which were that + + align:start position:0% +of that which were that + + + align:start position:0% +of that which were that +you know this function is a transport + + align:start position:0% +you know this function is a transport + + + align:start position:0% +you know this function is a transport +oxygen and so forth + + align:start position:0% +oxygen and so forth + + + align:start position:0% +oxygen and so forth +and the + + align:start position:0% +and the + + + align:start position:0% +and the +what we're talking about now is more + + align:start position:0% +what we're talking about now is more + + + align:start position:0% +what we're talking about now is more +cell brim brain issue that's on slide 13 + + align:start position:0% +cell brim brain issue that's on slide 13 + + + align:start position:0% +cell brim brain issue that's on slide 13 +where the internal environment + + align:start position:0% + + + + align:start position:0% + +which is the hemoglobin is greatly + + align:start position:0% +which is the hemoglobin is greatly + + + align:start position:0% +which is the hemoglobin is greatly +affecting now the external environment + + align:start position:0% +affecting now the external environment + + + align:start position:0% +affecting now the external environment +which is the hemodynamic flow in the in + + align:start position:0% +which is the hemodynamic flow in the in + + + align:start position:0% +which is the hemodynamic flow in the in +this in the uh + + align:start position:0% +this in the uh + + + align:start position:0% +this in the uh +capillaries + + align:start position:0% + + + + align:start position:0% + +so this falls under the heading it now + + align:start position:0% +so this falls under the heading it now + + + align:start position:0% +so this falls under the heading it now +of how is it that we can go from that + + align:start position:0% +of how is it that we can go from that + + + align:start position:0% +of how is it that we can go from that +single nucleotide change to a very + + align:start position:0% +single nucleotide change to a very + + + align:start position:0% +single nucleotide change to a very +dramatic morphological change in this + + align:start position:0% +dramatic morphological change in this + + + align:start position:0% +dramatic morphological change in this +case is pathological but you could + + align:start position:0% +case is pathological but you could + + + align:start position:0% +case is pathological but you could +imagine that in the hands of + + align:start position:0% +imagine that in the hands of + + + align:start position:0% +imagine that in the hands of +evolutionary adaptation + + align:start position:0% +evolutionary adaptation + + + align:start position:0% +evolutionary adaptation +an organism could take this and run with + + align:start position:0% +an organism could take this and run with + + + align:start position:0% +an organism could take this and run with +it maybe not sickle cell mutation but + + align:start position:0% +it maybe not sickle cell mutation but + + + align:start position:0% +it maybe not sickle cell mutation but +some other one that causes some other + + align:start position:0% +some other one that causes some other + + + align:start position:0% +some other one that causes some other +morphological change in some other cell + + align:start position:0% +morphological change in some other cell + + + align:start position:0% +morphological change in some other cell +or complex + + align:start position:0% +or complex + + + align:start position:0% +or complex +aggregate of cells + + align:start position:0% +aggregate of cells + + + align:start position:0% +aggregate of cells +because here you can see a whole variety + + align:start position:0% +because here you can see a whole variety + + + align:start position:0% +because here you can see a whole variety +of different + + align:start position:0% + + + + align:start position:0% + +shapes of of red blood cells and + + align:start position:0% +shapes of of red blood cells and + + + align:start position:0% +shapes of of red blood cells and +remember these red blood cells are very + + align:start position:0% +remember these red blood cells are very + + + align:start position:0% +remember these red blood cells are very +simple they have no + + align:start position:0% +simple they have no + + + align:start position:0% +simple they have no +macromolecular system no dna no rna so + + align:start position:0% +macromolecular system no dna no rna so + + + align:start position:0% +macromolecular system no dna no rna so +we're really just talking about a bag of + + align:start position:0% +we're really just talking about a bag of + + + align:start position:0% +we're really just talking about a bag of +proteins which are greatly affected by + + align:start position:0% +proteins which are greatly affected by + + + align:start position:0% +proteins which are greatly affected by +these different + + align:start position:0% +these different + + + align:start position:0% +these different +conditions or enzyme deficiencies so the + + align:start position:0% +conditions or enzyme deficiencies so the + + + align:start position:0% +conditions or enzyme deficiencies so the +system models that were built up where + + align:start position:0% +system models that were built up where + + + align:start position:0% +system models that were built up where +we had the kinetic parameters for it for + + align:start position:0% +we had the kinetic parameters for it for + + + align:start position:0% +we had the kinetic parameters for it for +the enzymes here can can in principle be + + align:start position:0% +the enzymes here can can in principle be + + + align:start position:0% +the enzymes here can can in principle be +modeled under the impact it would have + + align:start position:0% +modeled under the impact it would have + + + align:start position:0% +modeled under the impact it would have +on the on the osmolarity + + align:start position:0% +on the on the osmolarity + + + align:start position:0% +on the on the osmolarity +or the other membrane properties were + + align:start position:0% +or the other membrane properties were + + + align:start position:0% +or the other membrane properties were +listed in the previous slide or the + + align:start position:0% +listed in the previous slide or the + + + align:start position:0% +listed in the previous slide or the +sickling was in two slides back + + align:start position:0% +sickling was in two slides back + + + align:start position:0% +sickling was in two slides back +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so from a single + + align:start position:0% + + + + align:start position:0% + +nucleotide polymorphism we've gone to + + align:start position:0% +nucleotide polymorphism we've gone to + + + align:start position:0% +nucleotide polymorphism we've gone to +this three-dimensional fiber of + + align:start position:0% +this three-dimensional fiber of + + + align:start position:0% +this three-dimensional fiber of +hemoglobin + + align:start position:0% +hemoglobin + + + align:start position:0% +hemoglobin +to a + + align:start position:0% +to a + + + align:start position:0% +to a +change in the three-dimensional + + align:start position:0% +change in the three-dimensional + + + align:start position:0% +change in the three-dimensional +structure + + align:start position:0% +structure + + + align:start position:0% +structure +of this bicon + + align:start position:0% +of this bicon + + + align:start position:0% +of this bicon +cave + + align:start position:0% +cave + + + align:start position:0% +cave +disc + + align:start position:0% +disc + + + align:start position:0% +disc +to a sickle disc + + align:start position:0% +to a sickle disc + + + align:start position:0% +to a sickle disc +but you can also go sort of in parallel + + align:start position:0% +but you can also go sort of in parallel + + + align:start position:0% +but you can also go sort of in parallel +the same single nucleotide polymorphism + + align:start position:0% +the same single nucleotide polymorphism + + + align:start position:0% +the same single nucleotide polymorphism +or some like it can can take you up to + + align:start position:0% +or some like it can can take you up to + + + align:start position:0% +or some like it can can take you up to +pathogen resistance we've already + + align:start position:0% +pathogen resistance we've already + + + align:start position:0% +pathogen resistance we've already +mentioned that the sickle cell + + align:start position:0% +mentioned that the sickle cell + + + align:start position:0% +mentioned that the sickle cell +hemoglobin can take you to malarial + + align:start position:0% +hemoglobin can take you to malarial + + + align:start position:0% +hemoglobin can take you to malarial +resistance but in addition + + align:start position:0% +resistance but in addition + + + align:start position:0% +resistance but in addition +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you can get + + align:start position:0% +you can get + + + align:start position:0% +you can get +uh + + align:start position:0% +uh + + + align:start position:0% +uh +components of the + + align:start position:0% +components of the + + + align:start position:0% +components of the +enzymatic metabolic pathway such as + + align:start position:0% +enzymatic metabolic pathway such as + + + align:start position:0% +enzymatic metabolic pathway such as +the one that we modeled the + + align:start position:0% +the one that we modeled the + + + align:start position:0% +the one that we modeled the +two lectures back + + align:start position:0% +two lectures back + + + align:start position:0% +two lectures back +such as glutathione prostates this is + + align:start position:0% +such as glutathione prostates this is + + + align:start position:0% +such as glutathione prostates this is +part of the + + align:start position:0% +part of the + + + align:start position:0% +part of the +redox components + + align:start position:0% +redox components + + + align:start position:0% +redox components +and here uh erythrocytes that have that + + align:start position:0% +and here uh erythrocytes that have that + + + align:start position:0% +and here uh erythrocytes that have that +are heterozygous for this this + + align:start position:0% +are heterozygous for this this + + + align:start position:0% +are heterozygous for this this +particular allele + + align:start position:0% +particular allele + + + align:start position:0% +particular allele +um + + align:start position:0% + + + + align:start position:0% + +should be more efficient in sheltering + + align:start position:0% +should be more efficient in sheltering + + + align:start position:0% +should be more efficient in sheltering +the cell membrane from irreversible + + align:start position:0% +the cell membrane from irreversible + + + align:start position:0% +the cell membrane from irreversible +oxidation and binding hemoglobin caused + + align:start position:0% +oxidation and binding hemoglobin caused + + + align:start position:0% +oxidation and binding hemoglobin caused +by the oxygen stress this exerted by + + align:start position:0% +by the oxygen stress this exerted by + + + align:start position:0% +by the oxygen stress this exerted by +the malarial parasite + + align:start position:0% +the malarial parasite + + + align:start position:0% +the malarial parasite +and what they observe here is actually + + align:start position:0% +and what they observe here is actually + + + align:start position:0% +and what they observe here is actually +an interaction between + + align:start position:0% +an interaction between + + + align:start position:0% +an interaction between +the + + align:start position:0% +the + + + align:start position:0% +the +these two possible + + align:start position:0% +these two possible + + + align:start position:0% +these two possible +haplotypes + + align:start position:0% +haplotypes + + + align:start position:0% +haplotypes +so it's not so it's actually you can + + align:start position:0% +so it's not so it's actually you can + + + align:start position:0% +so it's not so it's actually you can +think of it as a pair of haplotypes it's + + align:start position:0% +think of it as a pair of haplotypes it's + + + align:start position:0% +think of it as a pair of haplotypes it's +the one is + + align:start position:0% +the one is + + + align:start position:0% +the one is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the hemoglobin as the one we've been + + align:start position:0% +the hemoglobin as the one we've been + + + align:start position:0% +the hemoglobin as the one we've been +talking about the sickling + + align:start position:0% +talking about the sickling + + + align:start position:0% +talking about the sickling +and then this glutathione peroxidase + + align:start position:0% +and then this glutathione peroxidase + + + align:start position:0% +and then this glutathione peroxidase +and so you can imagine is that since + + align:start position:0% +and so you can imagine is that since + + + align:start position:0% +and so you can imagine is that since +both of these things interact with + + align:start position:0% +both of these things interact with + + + align:start position:0% +both of these things interact with +malaria parasite that that your genotype + + align:start position:0% +malaria parasite that that your genotype + + + align:start position:0% +malaria parasite that that your genotype +will depend i'm sorry your phenotype of + + align:start position:0% +will depend i'm sorry your phenotype of + + + align:start position:0% +will depend i'm sorry your phenotype of +respective malaria will depend on + + align:start position:0% +respective malaria will depend on + + + align:start position:0% +respective malaria will depend on +the alleles that you have at both cases + + align:start position:0% +the alleles that you have at both cases + + + align:start position:0% +the alleles that you have at both cases +and so you can hear you have an a over s + + align:start position:0% +and so you can hear you have an a over s + + + align:start position:0% +and so you can hear you have an a over s +heterozygote and a two over one + + align:start position:0% +heterozygote and a two over one + + + align:start position:0% +heterozygote and a two over one +heterozygote + + align:start position:0% +heterozygote + + + align:start position:0% +heterozygote +and so that's something to take into + + align:start position:0% +and so that's something to take into + + + align:start position:0% +and so that's something to take into +account when you're trying to do any + + align:start position:0% +account when you're trying to do any + + + align:start position:0% +account when you're trying to do any +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +predictive modeling or x modeling it to + + align:start position:0% +predictive modeling or x modeling it to + + + align:start position:0% +predictive modeling or x modeling it to +explain + + align:start position:0% +explain + + + align:start position:0% +explain +the functional genomics that you have in + + align:start position:0% +the functional genomics that you have in + + + align:start position:0% +the functional genomics that you have in +a patient who's a compound heterozygote + + align:start position:0% +a patient who's a compound heterozygote + + + align:start position:0% +a patient who's a compound heterozygote +like that + + align:start position:0% +like that + + + align:start position:0% +like that +so now with the third pathway from now + + align:start position:0% +so now with the third pathway from now + + + align:start position:0% +so now with the third pathway from now +from single nu same set of single + + align:start position:0% +from single nu same set of single + + + align:start position:0% +from single nu same set of single +nucleotide polymorphisms that affect + + align:start position:0% +nucleotide polymorphisms that affect + + + align:start position:0% +nucleotide polymorphisms that affect +either hemoglobin or one of the major + + align:start position:0% +either hemoglobin or one of the major + + + align:start position:0% +either hemoglobin or one of the major +enzymes in red blood cell now + + align:start position:0% +enzymes in red blood cell now + + + align:start position:0% +enzymes in red blood cell now +you know one to cell morphology one to + + align:start position:0% +you know one to cell morphology one to + + + align:start position:0% +you know one to cell morphology one to +pathogen interaction and finally to + + align:start position:0% +pathogen interaction and finally to + + + align:start position:0% +pathogen interaction and finally to +interact with drugs we talked about + + align:start position:0% +interact with drugs we talked about + + + align:start position:0% +interact with drugs we talked about +pharmacogenomics here's another example + + align:start position:0% +pharmacogenomics here's another example + + + align:start position:0% +pharmacogenomics here's another example +where you have + + align:start position:0% +where you have + + + align:start position:0% +where you have +the drug induced oxidative hemolysis + + align:start position:0% +the drug induced oxidative hemolysis + + + align:start position:0% +the drug induced oxidative hemolysis +that you occur with certain + + align:start position:0% +that you occur with certain + + + align:start position:0% +that you occur with certain +enzyme opathies like glucose-6-phosphate + + align:start position:0% +enzyme opathies like glucose-6-phosphate + + + align:start position:0% +enzyme opathies like glucose-6-phosphate +dehydrogenase + + align:start position:0% +dehydrogenase + + + align:start position:0% +dehydrogenase +this these this enzyme + + align:start position:0% +this these this enzyme + + + align:start position:0% +this these this enzyme +glucose-6 phosphate dehydrogenase + + align:start position:0% +glucose-6 phosphate dehydrogenase + + + align:start position:0% +glucose-6 phosphate dehydrogenase +interacts with drugs such as + + align:start position:0% +interacts with drugs such as + + + align:start position:0% +interacts with drugs such as +primocline + + align:start position:0% +primocline + + + align:start position:0% +primocline +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +it disrupts + + align:start position:0% +it disrupts + + + align:start position:0% +it disrupts +mitochondrial function heme biosynthesis + + align:start position:0% +mitochondrial function heme biosynthesis + + + align:start position:0% +mitochondrial function heme biosynthesis +and so forth and so on + + align:start position:0% +and so forth and so on + + + align:start position:0% +and so forth and so on +this is + + align:start position:0% +this is + + + align:start position:0% +this is +a very significant uh + + align:start position:0% +a very significant uh + + + align:start position:0% +a very significant uh +consideration whether with a long list + + align:start position:0% +consideration whether with a long list + + + align:start position:0% +consideration whether with a long list +of 20-some drugs that has to be taken + + align:start position:0% +of 20-some drugs that has to be taken + + + align:start position:0% +of 20-some drugs that has to be taken +into account when you have any of a + + align:start position:0% +into account when you have any of a + + + align:start position:0% +into account when you have any of a +variety of red blood cell enzyme changes + + align:start position:0% +variety of red blood cell enzyme changes + + + align:start position:0% +variety of red blood cell enzyme changes +so + + align:start position:0% +so + + + align:start position:0% +so +we've got these three effects + + align:start position:0% +we've got these three effects + + + align:start position:0% +we've got these three effects +of a limited number of single nucleotide + + align:start position:0% +of a limited number of single nucleotide + + + align:start position:0% +of a limited number of single nucleotide +polymorphisms + + align:start position:0% +polymorphisms + + + align:start position:0% +polymorphisms +how + + align:start position:0% +how + + + align:start position:0% +how +do you make this transition from + + align:start position:0% +do you make this transition from + + + align:start position:0% +do you make this transition from +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and they're all somewhat interconnected + + align:start position:0% +and they're all somewhat interconnected + + + align:start position:0% +and they're all somewhat interconnected +part of the reason is resistant to + + align:start position:0% +part of the reason is resistant to + + + align:start position:0% +part of the reason is resistant to +malaria is because it's less effective + + align:start position:0% +malaria is because it's less effective + + + align:start position:0% +malaria is because it's less effective +in its cell shape and its ability to + + align:start position:0% +in its cell shape and its ability to + + + align:start position:0% +in its cell shape and its ability to +transport + + align:start position:0% +transport + + + align:start position:0% +transport +oxygen + + align:start position:0% +oxygen + + + align:start position:0% +oxygen +and + + align:start position:0% +and + + + align:start position:0% +and +do its metabolism + + align:start position:0% +do its metabolism + + + align:start position:0% +do its metabolism +the same thing with drug uh sensitivity + + align:start position:0% +the same thing with drug uh sensitivity + + + align:start position:0% +the same thing with drug uh sensitivity +how how are these uh changes in the in + + align:start position:0% +how how are these uh changes in the in + + + align:start position:0% +how how are these uh changes in the in +the hemoglobin + + align:start position:0% +the hemoglobin + + + align:start position:0% +the hemoglobin +um + + align:start position:0% +um + + + align:start position:0% +um +might they be reflected in the + + align:start position:0% +might they be reflected in the + + + align:start position:0% +might they be reflected in the +three-dimensional shape of the + + align:start position:0% +three-dimensional shape of the + + + align:start position:0% +three-dimensional shape of the +erythrocyte which is a kind of a + + align:start position:0% +erythrocyte which is a kind of a + + + align:start position:0% +erythrocyte which is a kind of a +membrane-bound compartment and here's a + + align:start position:0% +membrane-bound compartment and here's a + + + align:start position:0% +membrane-bound compartment and here's a +model that described me as interesting + + align:start position:0% +model that described me as interesting + + + align:start position:0% +model that described me as interesting +it's not it's + + align:start position:0% +it's not it's + + + align:start position:0% +it's not it's +not been that extensively tested since + + align:start position:0% +not been that extensively tested since + + + align:start position:0% +not been that extensively tested since +1998 but the idea is that band three + + align:start position:0% +1998 but the idea is that band three + + + align:start position:0% +1998 but the idea is that band three +this is uh one of those names that just + + align:start position:0% +this is uh one of those names that just + + + align:start position:0% +this is uh one of those names that just +comes out of the + + align:start position:0% +comes out of the + + + align:start position:0% +comes out of the +the molecular biologists literature that + + align:start position:0% +the molecular biologists literature that + + + align:start position:0% +the molecular biologists literature that +they ran a gel and they count the bands + + align:start position:0% +they ran a gel and they count the bands + + + align:start position:0% +they ran a gel and they count the bands +and number three and it turns out it's + + align:start position:0% +and number three and it turns out it's + + + align:start position:0% +and number three and it turns out it's +uh it's that it's about 10 of the of red + + align:start position:0% +uh it's that it's about 10 of the of red + + + align:start position:0% +uh it's that it's about 10 of the of red +blood cell membrane it's a very abundant + + align:start position:0% +blood cell membrane it's a very abundant + + + align:start position:0% +blood cell membrane it's a very abundant +protein + + align:start position:0% +protein + + + align:start position:0% +protein +and + + align:start position:0% +and + + + align:start position:0% +and +and it's responsible for + + align:start position:0% +and it's responsible for + + + align:start position:0% +and it's responsible for +the uh equilibration of anions such as + + align:start position:0% +the uh equilibration of anions such as + + + align:start position:0% +the uh equilibration of anions such as +carbonate and chloride across the + + align:start position:0% +carbonate and chloride across the + + + align:start position:0% +carbonate and chloride across the +regular cell membrane + + align:start position:0% +regular cell membrane + + + align:start position:0% +regular cell membrane +it's not a pump it just kind of + + align:start position:0% +it's not a pump it just kind of + + + align:start position:0% +it's not a pump it just kind of +allows these anions to go across because + + align:start position:0% +allows these anions to go across because + + + align:start position:0% +allows these anions to go across because +the pump here is the pumps that are + + align:start position:0% +the pump here is the pumps that are + + + align:start position:0% +the pump here is the pumps that are +involved in proton + + align:start position:0% +involved in proton + + + align:start position:0% +involved in proton +and + + align:start position:0% +and + + + align:start position:0% +and +there's also sodium potassium and that's + + align:start position:0% +there's also sodium potassium and that's + + + align:start position:0% +there's also sodium potassium and that's +what your atp in the blood blood cell is + + align:start position:0% +what your atp in the blood blood cell is + + + align:start position:0% +what your atp in the blood blood cell is +going for and this these are just kind + + align:start position:0% +going for and this these are just kind + + + align:start position:0% +going for and this these are just kind +of following along + + align:start position:0% +of following along + + + align:start position:0% +of following along +now you can the idea here is that uh + + align:start position:0% +now you can the idea here is that uh + + + align:start position:0% +now you can the idea here is that uh +if you can if you change + + align:start position:0% +if you can if you change + + + align:start position:0% +if you can if you change +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +degree let's see i think this is covered + + align:start position:0% +degree let's see i think this is covered + + + align:start position:0% +degree let's see i think this is covered +in more detail + + align:start position:0% + + + + align:start position:0% + +this the uh + + align:start position:0% +this the uh + + + align:start position:0% +this the uh +the + + align:start position:0% +the + + + align:start position:0% +the +mechanism of action here is a greatly + + align:start position:0% +mechanism of action here is a greatly + + + align:start position:0% +mechanism of action here is a greatly +affected by its disulfide effects if you + + align:start position:0% +affected by its disulfide effects if you + + + align:start position:0% +affected by its disulfide effects if you +change the the redox uh + + align:start position:0% +change the the redox uh + + + align:start position:0% +change the the redox uh +components in the red blood cell you get + + align:start position:0% +components in the red blood cell you get + + + align:start position:0% +components in the red blood cell you get +a slight just a slight change in + + align:start position:0% +a slight just a slight change in + + + align:start position:0% +a slight just a slight change in +confirmation of this molecule and then + + align:start position:0% +confirmation of this molecule and then + + + align:start position:0% +confirmation of this molecule and then +that can result in a net difference + + align:start position:0% +that can result in a net difference + + + align:start position:0% +that can result in a net difference +between this the cross-sectional area of + + align:start position:0% +between this the cross-sectional area of + + + align:start position:0% +between this the cross-sectional area of +this protein on the outside and the + + align:start position:0% +this protein on the outside and the + + + align:start position:0% +this protein on the outside and the +inside + + align:start position:0% +inside + + + align:start position:0% +inside +which + + align:start position:0% +which + + + align:start position:0% +which +translates into a net change since since + + align:start position:0% +translates into a net change since since + + + align:start position:0% +translates into a net change since since +the + + align:start position:0% +the + + + align:start position:0% +the +fossil lipids don't exchange uh the or + + align:start position:0% +fossil lipids don't exchange uh the or + + + align:start position:0% +fossil lipids don't exchange uh the or +the rate constant for the fossil lipid + + align:start position:0% +the rate constant for the fossil lipid + + + align:start position:0% +the rate constant for the fossil lipid +exchange is slow and known + + align:start position:0% +exchange is slow and known + + + align:start position:0% +exchange is slow and known +then this results in a uh + + align:start position:0% +then this results in a uh + + + align:start position:0% +then this results in a uh +in a + + align:start position:0% +in a + + + align:start position:0% +in a +conformational change + + align:start position:0% + + + + align:start position:0% + +anyway that's the model + + align:start position:0% +anyway that's the model + + + align:start position:0% +anyway that's the model +that connects the single nucleotide to + + align:start position:0% +that connects the single nucleotide to + + + align:start position:0% +that connects the single nucleotide to +could connect it to the the three muscle + + align:start position:0% +could connect it to the the three muscle + + + align:start position:0% +could connect it to the the three muscle +structure of the cell then you want to + + align:start position:0% +structure of the cell then you want to + + + align:start position:0% +structure of the cell then you want to +connect the three-dimensional structure + + align:start position:0% +connect the three-dimensional structure + + + align:start position:0% +connect the three-dimensional structure +of cell + + align:start position:0% +of cell + + + align:start position:0% +of cell +to uh its ability to carry out its + + align:start position:0% +to uh its ability to carry out its + + + align:start position:0% +to uh its ability to carry out its +function in the capillaries and function + + align:start position:0% +function in the capillaries and function + + + align:start position:0% +function in the capillaries and function +there is to + + align:start position:0% +there is to + + + align:start position:0% +there is to +allow the fusion of + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +oxygen and carbon dioxide + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% +and so + + + align:start position:0% +and so +um + + align:start position:0% + + + + align:start position:0% + +so here the each of these cells is + + align:start position:0% +so here the each of these cells is + + + align:start position:0% +so here the each of these cells is +shaped by a mechanical process and + + align:start position:0% +shaped by a mechanical process and + + + align:start position:0% +shaped by a mechanical process and +mechanical process here you can take the + + align:start position:0% +mechanical process here you can take the + + + align:start position:0% +mechanical process here you can take the +known uh + + align:start position:0% +known uh + + + align:start position:0% +known uh +or the measurable mechanical properties + + align:start position:0% +or the measurable mechanical properties + + + align:start position:0% +or the measurable mechanical properties +of red blood cell + + align:start position:0% +of red blood cell + + + align:start position:0% +of red blood cell +and subject them + + align:start position:0% +and subject them + + + align:start position:0% +and subject them +to a + + align:start position:0% +to a + + + align:start position:0% +to a +method called finite elements + + align:start position:0% +method called finite elements + + + align:start position:0% +method called finite elements +analysis where you're where you you're + + align:start position:0% +analysis where you're where you you're + + + align:start position:0% +analysis where you're where you you're +solving these uh partial differential + + align:start position:0% +solving these uh partial differential + + + align:start position:0% +solving these uh partial differential +equations + + align:start position:0% +equations + + + align:start position:0% +equations +and look and you can calculate the + + align:start position:0% +and look and you can calculate the + + + align:start position:0% +and look and you can calculate the +exchange of the + + align:start position:0% +exchange of the + + + align:start position:0% +exchange of the +oxygen of the + + align:start position:0% +oxygen of the + + + align:start position:0% +oxygen of the +alveolar just refers to this would be in + + align:start position:0% +alveolar just refers to this would be in + + + align:start position:0% +alveolar just refers to this would be in +in the lungs this would be a small + + align:start position:0% +in the lungs this would be a small + + + align:start position:0% +in the lungs this would be a small +catholic lungs and you see the capillary + + align:start position:0% +catholic lungs and you see the capillary + + + align:start position:0% +catholic lungs and you see the capillary +now endothelial walls are close enough + + align:start position:0% +now endothelial walls are close enough + + + align:start position:0% +now endothelial walls are close enough +so the red blood cells are basically uh + + align:start position:0% +so the red blood cells are basically uh + + + align:start position:0% +so the red blood cells are basically uh +deformed in their shape as they go + + align:start position:0% +deformed in their shape as they go + + + align:start position:0% +deformed in their shape as they go +through there and the exact shapes that + + align:start position:0% +through there and the exact shapes that + + + align:start position:0% +through there and the exact shapes that +are compatible with this will determine + + align:start position:0% +are compatible with this will determine + + + align:start position:0% +are compatible with this will determine +the rate these little arrows that go + + align:start position:0% +the rate these little arrows that go + + + align:start position:0% +the rate these little arrows that go +from the oxygen on the outside + + align:start position:0% +from the oxygen on the outside + + + align:start position:0% +from the oxygen on the outside +the longest uh epithelium get through + + align:start position:0% + + + + align:start position:0% + +so that's uh you know a reference uh + + align:start position:0% +so that's uh you know a reference uh + + + align:start position:0% +so that's uh you know a reference uh +that deals with that kind of problem + + align:start position:0% +that deals with that kind of problem + + + align:start position:0% +that deals with that kind of problem +now + + align:start position:0% +now + + + align:start position:0% +now +once + + align:start position:0% + + + + align:start position:0% + +as we start thinking about building up a + + align:start position:0% +as we start thinking about building up a + + + align:start position:0% +as we start thinking about building up a +larger system model the other parts of + + align:start position:0% +larger system model the other parts of + + + align:start position:0% +larger system model the other parts of +the system each of them so we've got a + + align:start position:0% +the system each of them so we've got a + + + align:start position:0% +the system each of them so we've got a +red blood cell model it's a metabolic + + align:start position:0% +red blood cell model it's a metabolic + + + align:start position:0% +red blood cell model it's a metabolic +model in principle it could also be + + align:start position:0% +model in principle it could also be + + + align:start position:0% +model in principle it could also be +a shape model and a diffusion model + + align:start position:0% +a shape model and a diffusion model + + + align:start position:0% +a shape model and a diffusion model +but the other parts of the of the system + + align:start position:0% +but the other parts of the of the system + + + align:start position:0% +but the other parts of the of the system +typically involve + + align:start position:0% + + + + align:start position:0% + +muscle cells they have the the smooth + + align:start position:0% +muscle cells they have the the smooth + + + align:start position:0% +muscle cells they have the the smooth +muscles + + align:start position:0% +muscles + + + align:start position:0% +muscles +throughout the entire + + align:start position:0% + + + + align:start position:0% + +arterial and venous system and and most + + align:start position:0% +arterial and venous system and and most + + + align:start position:0% +arterial and venous system and and most +significantly + + align:start position:0% +significantly + + + align:start position:0% +significantly +the the heart muscles and so + + align:start position:0% +the the heart muscles and so + + + align:start position:0% +the the heart muscles and so +here you have an example of an action + + align:start position:0% +here you have an example of an action + + + align:start position:0% +here you have an example of an action +potential in + + align:start position:0% +potential in + + + align:start position:0% +potential in +in one of the ventricular cells of the + + align:start position:0% +in one of the ventricular cells of the + + + align:start position:0% +in one of the ventricular cells of the +of the dog heart + + align:start position:0% +of the dog heart + + + align:start position:0% +of the dog heart +and it includes all the components that + + align:start position:0% +and it includes all the components that + + + align:start position:0% +and it includes all the components that +that + + align:start position:0% +that + + + align:start position:0% +that +at least least this is not an entire + + align:start position:0% +at least least this is not an entire + + + align:start position:0% +at least least this is not an entire +course on + + align:start position:0% + + + + align:start position:0% + +ventricular + + align:start position:0% +ventricular + + + align:start position:0% +ventricular +part modeling + + align:start position:0% +part modeling + + + align:start position:0% +part modeling +this this is for sort of parameters in + + align:start position:0% +this this is for sort of parameters in + + + align:start position:0% +this this is for sort of parameters in +terms of all the eyes the currents for + + align:start position:0% +terms of all the eyes the currents for + + + align:start position:0% +terms of all the eyes the currents for +each of the different potassium channels + + align:start position:0% +each of the different potassium channels + + + align:start position:0% +each of the different potassium channels +the k + + align:start position:0% +the k + + + align:start position:0% +the k +all the features of the ones the i sub k + + align:start position:0% +all the features of the ones the i sub k + + + align:start position:0% +all the features of the ones the i sub k +is all potassium and then there's some + + align:start position:0% +is all potassium and then there's some + + + align:start position:0% +is all potassium and then there's some +of sodium and sodium and calcium calcium + + align:start position:0% +of sodium and sodium and calcium calcium + + + align:start position:0% +of sodium and sodium and calcium calcium +calcium sodium alone it's the east of + + align:start position:0% +calcium sodium alone it's the east of + + + align:start position:0% +calcium sodium alone it's the east of +these things that internal source of + + align:start position:0% +these things that internal source of + + + align:start position:0% +these things that internal source of +calcium that go from one + + align:start position:0% +calcium that go from one + + + align:start position:0% +calcium that go from one +subcellular compartment to another + + align:start position:0% +subcellular compartment to another + + + align:start position:0% +subcellular compartment to another +and and and so on you get the idea each + + align:start position:0% +and and and so on you get the idea each + + + align:start position:0% +and and and so on you get the idea each +of these things has to have the + + align:start position:0% +of these things has to have the + + + align:start position:0% +of these things has to have the +parameters measured + + align:start position:0% +parameters measured + + + align:start position:0% +parameters measured +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +any other absent you have to uh have + + align:start position:0% +any other absent you have to uh have + + + align:start position:0% +any other absent you have to uh have +reasonable + + align:start position:0% +reasonable + + + align:start position:0% +reasonable +ways of getting + + align:start position:0% +ways of getting + + + align:start position:0% +ways of getting +surrogates + + align:start position:0% +surrogates + + + align:start position:0% +surrogates +and so this is the sort this is just + + align:start position:0% +and so this is the sort this is just + + + align:start position:0% +and so this is the sort this is just +the sort of data that would go into the + + align:start position:0% +the sort of data that would go into the + + + align:start position:0% +the sort of data that would go into the +other major type of cell that is that + + align:start position:0% +other major type of cell that is that + + + align:start position:0% +other major type of cell that is that +comes into this cardiovascular + + align:start position:0% +comes into this cardiovascular + + + align:start position:0% +comes into this cardiovascular +modeling + + align:start position:0% +modeling + + + align:start position:0% +modeling +and finally you can integrate this uh up + + align:start position:0% +and finally you can integrate this uh up + + + align:start position:0% +and finally you can integrate this uh up +to a fairly complete system it's + + align:start position:0% +to a fairly complete system it's + + + align:start position:0% +to a fairly complete system it's +obviously not complete if you get to the + + align:start position:0% +obviously not complete if you get to the + + + align:start position:0% +obviously not complete if you get to the +whole organism but + + align:start position:0% +whole organism but + + + align:start position:0% +whole organism but +higher level and we're how we're talking + + align:start position:0% +higher level and we're how we're talking + + + align:start position:0% +higher level and we're how we're talking +about whole body recirculation + + align:start position:0% +about whole body recirculation + + + align:start position:0% +about whole body recirculation +uh this nsr group uh this is the + + align:start position:0% +uh this nsr group uh this is the + + + align:start position:0% +uh this nsr group uh this is the +hypertext link for this particular model + + align:start position:0% +hypertext link for this particular model + + + align:start position:0% +hypertext link for this particular model +that you can download and it has a four + + align:start position:0% +that you can download and it has a four + + + align:start position:0% +that you can download and it has a four +chambered heart we were just talking + + align:start position:0% +chambered heart we were just talking + + + align:start position:0% +chambered heart we were just talking +about one ventricular cell in the + + align:start position:0% +about one ventricular cell in the + + + align:start position:0% +about one ventricular cell in the +previous slide but that would be + + align:start position:0% +previous slide but that would be + + + align:start position:0% +previous slide but that would be +we looked at the second box from the top + + align:start position:0% +we looked at the second box from the top + + + align:start position:0% +we looked at the second box from the top +here this is the where the heart from + + align:start position:0% +here this is the where the heart from + + + align:start position:0% +here this is the where the heart from +lung + + align:start position:0% +lung + + + align:start position:0% +lung +models which fit in there it's got seven + + align:start position:0% +models which fit in there it's got seven + + + align:start position:0% +models which fit in there it's got seven +different organs which include kidney + + align:start position:0% +different organs which include kidney + + + align:start position:0% +different organs which include kidney +liver gut flower limbs and so forth down + + align:start position:0% +liver gut flower limbs and so forth down + + + align:start position:0% +liver gut flower limbs and so forth down +the bottom part of the bag + + align:start position:0% +the bottom part of the bag + + + align:start position:0% +the bottom part of the bag +get the picture each of these things you + + align:start position:0% +get the picture each of these things you + + + align:start position:0% +get the picture each of these things you +your mod you're modeling the the volumes + + align:start position:0% +your mod you're modeling the the volumes + + + align:start position:0% +your mod you're modeling the the volumes +and flows + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now this is systems biology this is + + align:start position:0% +now this is systems biology this is + + + align:start position:0% +now this is systems biology this is +really uh + + align:start position:0% +really uh + + + align:start position:0% +really uh +kind of a renaissance of interest in + + align:start position:0% +kind of a renaissance of interest in + + + align:start position:0% +kind of a renaissance of interest in +physiology is what it would have been + + align:start position:0% +physiology is what it would have been + + + align:start position:0% +physiology is what it would have been +called before and there are some really + + align:start position:0% +called before and there are some really + + + align:start position:0% +called before and there are some really +interesting um + + align:start position:0% +interesting um + + + align:start position:0% +interesting um +mysteries out there to be solved + + align:start position:0% +mysteries out there to be solved + + + align:start position:0% +mysteries out there to be solved +that are really only solvable or + + align:start position:0% +that are really only solvable or + + + align:start position:0% +that are really only solvable or +possibly only solve with the system + + align:start position:0% +possibly only solve with the system + + + align:start position:0% +possibly only solve with the system +level you know you never know you + + align:start position:0% +level you know you never know you + + + align:start position:0% +level you know you never know you +somebody could come up and say oh yeah + + align:start position:0% +somebody could come up and say oh yeah + + + align:start position:0% +somebody could come up and say oh yeah +this is this is really well understood + + align:start position:0% +this is this is really well understood + + + align:start position:0% +this is this is really well understood +uh immunology and that answers + + align:start position:0% +uh immunology and that answers + + + align:start position:0% +uh immunology and that answers +everything but even if it's some kind of + + align:start position:0% +everything but even if it's some kind of + + + align:start position:0% +everything but even if it's some kind of +immunology + + align:start position:0% +immunology + + + align:start position:0% +immunology +or + + align:start position:0% +or + + + align:start position:0% +or +um + + align:start position:0% +um + + + align:start position:0% +um +you still have to say how does it play + + align:start position:0% +you still have to say how does it play + + + align:start position:0% +you still have to say how does it play +out and what happens is we've been + + align:start position:0% +out and what happens is we've been + + + align:start position:0% +out and what happens is we've been +talking about sickle cell disease + + align:start position:0% +talking about sickle cell disease + + + align:start position:0% +talking about sickle cell disease +and you can have fairly mild pain as one + + align:start position:0% +and you can have fairly mild pain as one + + + align:start position:0% +and you can have fairly mild pain as one +of the major symptoms um but then all of + + align:start position:0% +of the major symptoms um but then all of + + + align:start position:0% +of the major symptoms um but then all of +a sudden out of nowhere you'll get this + + align:start position:0% +a sudden out of nowhere you'll get this + + + align:start position:0% +a sudden out of nowhere you'll get this +multi-organ system failure where uh + + align:start position:0% +multi-organ system failure where uh + + + align:start position:0% +multi-organ system failure where uh +you know almost every major organ in + + align:start position:0% +you know almost every major organ in + + + align:start position:0% +you know almost every major organ in +that previous slide long as the + + align:start position:0% +that previous slide long as the + + + align:start position:0% +that previous slide long as the +so-called fill up with fluid and + + align:start position:0% +so-called fill up with fluid and + + + align:start position:0% +so-called fill up with fluid and +and you have a very high chance of dying + + align:start position:0% +and you have a very high chance of dying + + + align:start position:0% +and you have a very high chance of dying +and this could happen to every one of us + + align:start position:0% +and this could happen to every one of us + + + align:start position:0% +and this could happen to every one of us +in this room because it's not restricted + + align:start position:0% +in this room because it's not restricted + + + align:start position:0% +in this room because it's not restricted +to sickle cell + + align:start position:0% +to sickle cell + + + align:start position:0% +to sickle cell +if any of you have severe uh + + align:start position:0% +if any of you have severe uh + + + align:start position:0% +if any of you have severe uh +burn or or car crash + + align:start position:0% +burn or or car crash + + + align:start position:0% +burn or or car crash +major bone injuries + + align:start position:0% +major bone injuries + + + align:start position:0% +major bone injuries +you have a very good chance of dealing + + align:start position:0% +you have a very good chance of dealing + + + align:start position:0% +you have a very good chance of dealing +with multi-organ system failure it + + align:start position:0% +with multi-organ system failure it + + + align:start position:0% +with multi-organ system failure it +really isn't known how + + align:start position:0% +really isn't known how + + + align:start position:0% +really isn't known how +that plays out i mean not even that not + + align:start position:0% +that plays out i mean not even that not + + + align:start position:0% +that plays out i mean not even that not +just a quantitative model but uh even + + align:start position:0% +just a quantitative model but uh even + + + align:start position:0% +just a quantitative model but uh even +qualitatively + + align:start position:0% +qualitatively + + + align:start position:0% +qualitatively +so i think this is something there are + + align:start position:0% +so i think this is something there are + + + align:start position:0% +so i think this is something there are +projects now to do to get genomic data + + align:start position:0% +projects now to do to get genomic data + + + align:start position:0% +projects now to do to get genomic data +collection both genetic and um + + align:start position:0% +collection both genetic and um + + + align:start position:0% +collection both genetic and um +expression data and time will tell + + align:start position:0% +expression data and time will tell + + + align:start position:0% +expression data and time will tell +whether that is + + align:start position:0% +whether that is + + + align:start position:0% +whether that is +actually a + + align:start position:0% +actually a + + + align:start position:0% +actually a +the best route to solving that mystery + + align:start position:0% +the best route to solving that mystery + + + align:start position:0% +the best route to solving that mystery +so that was multi-organ now we're + + align:start position:0% +so that was multi-organ now we're + + + align:start position:0% +so that was multi-organ now we're +talking about multi-organism okay + + align:start position:0% +talking about multi-organism okay + + + align:start position:0% +talking about multi-organism okay +after you've built up + + align:start position:0% +after you've built up + + + align:start position:0% +after you've built up +an entire organism uh + + align:start position:0% +an entire organism uh + + + align:start position:0% +an entire organism uh +then you want to know how it acts at the + + align:start position:0% +then you want to know how it acts at the + + + align:start position:0% +then you want to know how it acts at the +next level of network analysis which is + + align:start position:0% +next level of network analysis which is + + + align:start position:0% +next level of network analysis which is +how does it fit in with other organisms + + align:start position:0% + + + + align:start position:0% + +none of us + + align:start position:0% +none of us + + + align:start position:0% +none of us +almost no organism really belongs in + + align:start position:0% +almost no organism really belongs in + + + align:start position:0% +almost no organism really belongs in +ecological niche all by itself + + align:start position:0% +ecological niche all by itself + + + align:start position:0% +ecological niche all by itself +and + + align:start position:0% + + + + align:start position:0% + +some + + align:start position:0% +some + + + align:start position:0% +some +some of the modeling we've talked in + + align:start position:0% +some of the modeling we've talked in + + + align:start position:0% +some of the modeling we've talked in +this course could be called simulation + + align:start position:0% +this course could be called simulation + + + align:start position:0% +this course could be called simulation +and uh probably one of the longest + + align:start position:0% +and uh probably one of the longest + + + align:start position:0% +and uh probably one of the longest +lasting uh + + align:start position:0% +lasting uh + + + align:start position:0% +lasting uh +computer games + + align:start position:0% +computer games + + + align:start position:0% +computer games +in the world and one of the most + + align:start position:0% +in the world and one of the most + + + align:start position:0% +in the world and one of the most +successful i've i've heard + + align:start position:0% +successful i've i've heard + + + align:start position:0% +successful i've i've heard +is the + + align:start position:0% +is the + + + align:start position:0% +is the +the sims + + align:start position:0% +the sims + + + align:start position:0% +the sims +starting with sim city in uh + + align:start position:0% + + + + align:start position:0% + +simcity in 87 + + align:start position:0% +simcity in 87 + + + align:start position:0% +simcity in 87 +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and then this particular one illustrated + + align:start position:0% +and then this particular one illustrated + + + align:start position:0% +and then this particular one illustrated +here is sim life which is all about + + align:start position:0% +here is sim life which is all about + + + align:start position:0% +here is sim life which is all about +ecological modeling and it's not + + align:start position:0% +ecological modeling and it's not + + + align:start position:0% +ecological modeling and it's not +entirely different from what you know a + + align:start position:0% +entirely different from what you know a + + + align:start position:0% +entirely different from what you know a +serious + + align:start position:0% +serious + + + align:start position:0% +serious +uh ecological modeling program would do + + align:start position:0% +uh ecological modeling program would do + + + align:start position:0% +uh ecological modeling program would do +it certainly has a lot of the + + align:start position:0% +it certainly has a lot of the + + + align:start position:0% +it certainly has a lot of the +interesting parameters such as the + + align:start position:0% +interesting parameters such as the + + + align:start position:0% +interesting parameters such as the +lifespan + + align:start position:0% +lifespan + + + align:start position:0% +lifespan +here you know you're doing demographics + + align:start position:0% +here you know you're doing demographics + + + align:start position:0% +here you know you're doing demographics +here so you have the lifespan + + align:start position:0% +here so you have the lifespan + + + align:start position:0% +here so you have the lifespan +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know food needed uh + + align:start position:0% + + + + align:start position:0% + +the size + + align:start position:0% +the size + + + align:start position:0% +the size +kind of vision roaming so forth of all + + align:start position:0% +kind of vision roaming so forth of all + + + align:start position:0% +kind of vision roaming so forth of all +these different different kinds of + + align:start position:0% +these different different kinds of + + + align:start position:0% +these different different kinds of +animals you can have uh + + align:start position:0% +animals you can have uh + + + align:start position:0% +animals you can have uh +herbert + + align:start position:0% +herbert + + + align:start position:0% +herbert +you can have plants you have herbivores + + align:start position:0% +you can have plants you have herbivores + + + align:start position:0% +you can have plants you have herbivores +carnivores + + align:start position:0% +carnivores + + + align:start position:0% +carnivores +and so on and then you can set up the + + align:start position:0% +and so on and then you can set up the + + + align:start position:0% +and so on and then you can set up the +population sizes and then it will do + + align:start position:0% +population sizes and then it will do + + + align:start position:0% +population sizes and then it will do +simulations + + align:start position:0% +simulations + + + align:start position:0% +simulations +uh based on that where each each + + align:start position:0% +uh based on that where each each + + + align:start position:0% +uh based on that where each each +individual animal + + align:start position:0% +individual animal + + + align:start position:0% +individual animal +is uh tracked in terms of uh positioning + + align:start position:0% +is uh tracked in terms of uh positioning + + + align:start position:0% +is uh tracked in terms of uh positioning +and quantity and + + align:start position:0% +and quantity and + + + align:start position:0% +and quantity and +uh and as you would expect as the you + + align:start position:0% +uh and as you would expect as the you + + + align:start position:0% +uh and as you would expect as the you +know carnivores build up and they knock + + align:start position:0% +know carnivores build up and they knock + + + align:start position:0% +know carnivores build up and they knock +down the herbivores and the plants go up + + align:start position:0% +down the herbivores and the plants go up + + + align:start position:0% +down the herbivores and the plants go up +and and so forth and it goes through + + align:start position:0% +and and so forth and it goes through + + + align:start position:0% +and and so forth and it goes through +these cycles + + align:start position:0% +these cycles + + + align:start position:0% +these cycles +um + + align:start position:0% +um + + + align:start position:0% +um +and so this is basically a stochastic + + align:start position:0% +and so this is basically a stochastic + + + align:start position:0% +and so this is basically a stochastic +model just like the stochastic models + + align:start position:0% +model just like the stochastic models + + + align:start position:0% +model just like the stochastic models +that we had for um + + align:start position:0% +that we had for um + + + align:start position:0% +that we had for um +for molecules but here at the organism + + align:start position:0% +for molecules but here at the organism + + + align:start position:0% +for molecules but here at the organism +level + + align:start position:0% +level + + + align:start position:0% +level +and what's happening here in the slower + + align:start position:0% +and what's happening here in the slower + + + align:start position:0% +and what's happening here in the slower +right-hand section is you've got little + + align:start position:0% +right-hand section is you've got little + + + align:start position:0% +right-hand section is you've got little +green plants uh + + align:start position:0% +green plants uh + + + align:start position:0% +green plants uh +getting eaten by herbivores and the + + align:start position:0% +getting eaten by herbivores and the + + + align:start position:0% +getting eaten by herbivores and the +orbitals getting in by carnivores + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +hopefully this course + + align:start position:0% +hopefully this course + + + align:start position:0% +hopefully this course +has already or will inspire you to to + + align:start position:0% +has already or will inspire you to to + + + align:start position:0% +has already or will inspire you to to +really + + align:start position:0% +really + + + align:start position:0% +really +think globally to think not only + + align:start position:0% +think globally to think not only + + + align:start position:0% +think globally to think not only +globally in terms of + + align:start position:0% +globally in terms of + + + align:start position:0% +globally in terms of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +how + + align:start position:0% +how + + + align:start position:0% +how +little pieces of molecular tools fit + + align:start position:0% +little pieces of molecular tools fit + + + align:start position:0% +little pieces of molecular tools fit +together into systems and networks but + + align:start position:0% +together into systems and networks but + + + align:start position:0% +together into systems and networks but +how our systems and networks we model + + align:start position:0% +how our systems and networks we model + + + align:start position:0% +how our systems and networks we model +fit into the big picture of what's what + + align:start position:0% +fit into the big picture of what's what + + + align:start position:0% +fit into the big picture of what's what +are really important problems + + align:start position:0% +are really important problems + + + align:start position:0% +are really important problems +you know + + align:start position:0% +you know + + + align:start position:0% +you know +maybe a slightly improved + + align:start position:0% +maybe a slightly improved + + + align:start position:0% +maybe a slightly improved +viagra is not + + align:start position:0% +viagra is not + + + align:start position:0% +viagra is not +in the same category as a new + + align:start position:0% +in the same category as a new + + + align:start position:0% +in the same category as a new +tuberculosis drug or maybe it is i mean + + align:start position:0% +tuberculosis drug or maybe it is i mean + + + align:start position:0% +tuberculosis drug or maybe it is i mean +you decide for yourself + + align:start position:0% +you decide for yourself + + + align:start position:0% +you decide for yourself +what is thinking globally but you have + + align:start position:0% +what is thinking globally but you have + + + align:start position:0% +what is thinking globally but you have +to act locally and that's what we're + + align:start position:0% +to act locally and that's what we're + + + align:start position:0% +to act locally and that's what we're +doing in this class + + align:start position:0% +doing in this class + + + align:start position:0% +doing in this class +um + + align:start position:0% +um + + + align:start position:0% +um +when we're thinking globally and we're + + align:start position:0% +when we're thinking globally and we're + + + align:start position:0% +when we're thinking globally and we're +thinking about ecological systems + + align:start position:0% +thinking about ecological systems + + + align:start position:0% +thinking about ecological systems +we're thinking about + + align:start position:0% +we're thinking about + + + align:start position:0% +we're thinking about +the lithosphere + + align:start position:0% +the lithosphere + + + align:start position:0% +the lithosphere +for the most part + + align:start position:0% +for the most part + + + align:start position:0% +for the most part +and its interaction with + + align:start position:0% +and its interaction with + + + align:start position:0% +and its interaction with +the hydrosphere + + align:start position:0% +the hydrosphere + + + align:start position:0% +the hydrosphere +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +lithosphere is mostly silicon dioxide a + + align:start position:0% +lithosphere is mostly silicon dioxide a + + + align:start position:0% +lithosphere is mostly silicon dioxide a +tiny bit of carbon + + align:start position:0% +tiny bit of carbon + + + align:start position:0% +tiny bit of carbon +and it gets very hot very quickly so + + align:start position:0% +and it gets very hot very quickly so + + + align:start position:0% +and it gets very hot very quickly so +um + + align:start position:0% + + + + align:start position:0% + +only the top + + align:start position:0% +only the top + + + align:start position:0% +only the top +point one percent the top four + + align:start position:0% +point one percent the top four + + + align:start position:0% +point one percent the top four +kilometers of it is uh survivable in any + + align:start position:0% +kilometers of it is uh survivable in any + + + align:start position:0% +kilometers of it is uh survivable in any +type of organism we know of about 110 + + align:start position:0% +type of organism we know of about 110 + + + align:start position:0% +type of organism we know of about 110 +degrees centigrade is where organisms + + align:start position:0% +degrees centigrade is where organisms + + + align:start position:0% +degrees centigrade is where organisms +start having uh gay field trouble you + + align:start position:0% +start having uh gay field trouble you + + + align:start position:0% +start having uh gay field trouble you +and i would have trouble before that + + align:start position:0% + + + + align:start position:0% + +the biosphere + + align:start position:0% +the biosphere + + + align:start position:0% +the biosphere +here is about 315 grams + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +my estimate + + align:start position:0% +my estimate + + + align:start position:0% +my estimate +for + + align:start position:0% +for + + + align:start position:0% +for +marine + + align:start position:0% +marine + + + align:start position:0% +marine +organisms + + align:start position:0% +organisms + + + align:start position:0% +organisms +and maybe 10 to the + + align:start position:0% +and maybe 10 to the + + + align:start position:0% +and maybe 10 to the +18th gram for + + align:start position:0% +18th gram for + + + align:start position:0% +18th gram for +all land plants and animals and + + align:start position:0% +all land plants and animals and + + + align:start position:0% +all land plants and animals and +microorganisms + + align:start position:0% +microorganisms + + + align:start position:0% +microorganisms +the microbial hydrosphere uh + + align:start position:0% +the microbial hydrosphere uh + + + align:start position:0% +the microbial hydrosphere uh +here is about uh + + align:start position:0% +here is about uh + + + align:start position:0% +here is about uh +10 to the 24 20 + + align:start position:0% +10 to the 24 20 + + + align:start position:0% +10 to the 24 20 + + align:start position:0% + + + align:start position:0% +milliliters which works at about 10 to + + align:start position:0% +milliliters which works at about 10 to + + + align:start position:0% +milliliters which works at about 10 to +27 cells a phenomenal number of these + + align:start position:0% +27 cells a phenomenal number of these + + + align:start position:0% +27 cells a phenomenal number of these +cells about 10 to the 26 of those cells + + align:start position:0% +cells about 10 to the 26 of those cells + + + align:start position:0% +cells about 10 to the 26 of those cells +is a single species which is + + align:start position:0% +is a single species which is + + + align:start position:0% +is a single species which is +prochlorococcus which is responsible for + + align:start position:0% +prochlorococcus which is responsible for + + + align:start position:0% +prochlorococcus which is responsible for +um + + align:start position:0% +um + + + align:start position:0% +um +maybe about 50 + + align:start position:0% +maybe about 50 + + + align:start position:0% +maybe about 50 +of your photosynthesis + + align:start position:0% +of your photosynthesis + + + align:start position:0% +of your photosynthesis +a lot of that photosynthesis does not + + align:start position:0% +a lot of that photosynthesis does not + + + align:start position:0% +a lot of that photosynthesis does not +end up in fixed carbon because it + + align:start position:0% +end up in fixed carbon because it + + + align:start position:0% +end up in fixed carbon because it +is immediately consumed by one of its + + align:start position:0% +is immediately consumed by one of its + + + align:start position:0% +is immediately consumed by one of its +other + + align:start position:0% + + + + align:start position:0% + +predators basically um + + align:start position:0% +predators basically um + + + align:start position:0% +predators basically um +but there's a you know there's really + + align:start position:0% +but there's a you know there's really + + + align:start position:0% +but there's a you know there's really +quite a lot of uh + + align:start position:0% +quite a lot of uh + + + align:start position:0% +quite a lot of uh +cells out there + + align:start position:0% +cells out there + + + align:start position:0% +cells out there +which to the extent that they're well + + align:start position:0% +which to the extent that they're well + + + align:start position:0% +which to the extent that they're well +mixed and they're not of course it's not + + align:start position:0% +mixed and they're not of course it's not + + + align:start position:0% +mixed and they're not of course it's not +perfectly mixed all the pacific and + + align:start position:0% +perfectly mixed all the pacific and + + + align:start position:0% +perfectly mixed all the pacific and +atlantic and so forth but it's it's a + + align:start position:0% +atlantic and so forth but it's it's a + + + align:start position:0% +atlantic and so forth but it's it's a +considerably more well mixed say than + + align:start position:0% +considerably more well mixed say than + + + align:start position:0% +considerably more well mixed say than +the lithosphere organisms where you have + + align:start position:0% +the lithosphere organisms where you have + + + align:start position:0% +the lithosphere organisms where you have +organisms down + + align:start position:0% +organisms down + + + align:start position:0% +organisms down +a kilometer into the ground they don't + + align:start position:0% +a kilometer into the ground they don't + + + align:start position:0% +a kilometer into the ground they don't +move around + + align:start position:0% +move around + + + align:start position:0% +move around +very rapidly + + align:start position:0% +very rapidly + + + align:start position:0% +very rapidly +so when you have a population of that + + align:start position:0% +so when you have a population of that + + + align:start position:0% +so when you have a population of that +size you'll remember from our one of our + + align:start position:0% +size you'll remember from our one of our + + + align:start position:0% +size you'll remember from our one of our +first lectures on population science the + + align:start position:0% +first lectures on population science the + + + align:start position:0% +first lectures on population science the +effect of population size determines the + + align:start position:0% +effect of population size determines the + + + align:start position:0% +effect of population size determines the +rate of drift and the sort of the + + align:start position:0% + + + + align:start position:0% + +optimality of the organism + + align:start position:0% +optimality of the organism + + + align:start position:0% +optimality of the organism +so one of the things that we do when we + + align:start position:0% +so one of the things that we do when we + + + align:start position:0% +so one of the things that we do when we +we've been talking about mining the + + align:start position:0% +we've been talking about mining the + + + align:start position:0% +we've been talking about mining the +biosphere one of the things we're + + align:start position:0% +biosphere one of the things we're + + + align:start position:0% +biosphere one of the things we're +looking for are new + + align:start position:0% +looking for are new + + + align:start position:0% +looking for are new +tools that we can use for um + + align:start position:0% +tools that we can use for um + + + align:start position:0% +tools that we can use for um +for nano engineering + + align:start position:0% +for nano engineering + + + align:start position:0% +for nano engineering +and one of the one kind of one of my pet + + align:start position:0% +and one of the one kind of one of my pet + + + align:start position:0% +and one of the one kind of one of my pet +ones that i'm becoming interested in we + + align:start position:0% +ones that i'm becoming interested in we + + + align:start position:0% +ones that i'm becoming interested in we +don't work on this i think they're just + + align:start position:0% +don't work on this i think they're just + + + align:start position:0% +don't work on this i think they're just +kind of interesting is uh there's a set + + align:start position:0% +kind of interesting is uh there's a set + + + align:start position:0% +kind of interesting is uh there's a set +of we mentioned this briefly in the drug + + align:start position:0% +of we mentioned this briefly in the drug + + + align:start position:0% +of we mentioned this briefly in the drug +um + + align:start position:0% +um + + + align:start position:0% +um +protein interaction lecture + + align:start position:0% +protein interaction lecture + + + align:start position:0% +protein interaction lecture +where uh but i don't think i've + + align:start position:0% +where uh but i don't think i've + + + align:start position:0% +where uh but i don't think i've +mentioned this particular one where you + + align:start position:0% +mentioned this particular one where you + + + align:start position:0% +mentioned this particular one where you +have + + align:start position:0% +have + + + align:start position:0% +have +they polypeptides together it's kind of + + align:start position:0% +they polypeptides together it's kind of + + + align:start position:0% +they polypeptides together it's kind of +a pau it's another polymer that has + + align:start position:0% +a pau it's another polymer that has + + + align:start position:0% +a pau it's another polymer that has +certain similarities to the basic + + align:start position:0% +certain similarities to the basic + + + align:start position:0% +certain similarities to the basic +polymer to talk about but each step in + + align:start position:0% +polymer to talk about but each step in + + + align:start position:0% +polymer to talk about but each step in +it had to have a protein enzyme um + + align:start position:0% +it had to have a protein enzyme um + + + align:start position:0% +it had to have a protein enzyme um +an enzymatic domain to accomplish now + + align:start position:0% +an enzymatic domain to accomplish now + + + align:start position:0% +an enzymatic domain to accomplish now +and so one of these is tetracycline and + + align:start position:0% +and so one of these is tetracycline and + + + align:start position:0% +and so one of these is tetracycline and +this is one of the more aromatic you + + align:start position:0% +this is one of the more aromatic you + + + align:start position:0% +this is one of the more aromatic you +know kind of coupled aromatic compounds + + align:start position:0% +know kind of coupled aromatic compounds + + + align:start position:0% +know kind of coupled aromatic compounds +that's made because you have these + + align:start position:0% +that's made because you have these + + + align:start position:0% +that's made because you have these +cyclases and aromatases in addition to + + align:start position:0% +cyclases and aromatases in addition to + + + align:start position:0% +cyclases and aromatases in addition to +the + + align:start position:0% +the + + + align:start position:0% +the +sort of polymerization steps + + align:start position:0% +sort of polymerization steps + + + align:start position:0% +sort of polymerization steps +as you make this thing that's a it looks + + align:start position:0% +as you make this thing that's a it looks + + + align:start position:0% +as you make this thing that's a it looks +kind of like a poly uh + + align:start position:0% +kind of like a poly uh + + + align:start position:0% +kind of like a poly uh +aromatic hydrocarbon + + align:start position:0% +aromatic hydrocarbon + + + align:start position:0% +aromatic hydrocarbon +and and also in nature you will find + + align:start position:0% +and and also in nature you will find + + + align:start position:0% +and and also in nature you will find +in soot in forest fires and all kinds of + + align:start position:0% +in soot in forest fires and all kinds of + + + align:start position:0% +in soot in forest fires and all kinds of +natural phenomena you'll find prostate + + align:start position:0% +natural phenomena you'll find prostate + + + align:start position:0% +natural phenomena you'll find prostate +hydro + + align:start position:0% +hydro + + + align:start position:0% +hydro +aromatic hydrocarbons for some of you + + align:start position:0% +aromatic hydrocarbons for some of you + + + align:start position:0% +aromatic hydrocarbons for some of you +may know about as being a potent + + align:start position:0% +may know about as being a potent + + + align:start position:0% +may know about as being a potent +carcinogen but they're also just you + + align:start position:0% +carcinogen but they're also just you + + + align:start position:0% +carcinogen but they're also just you +know natural + + align:start position:0% +know natural + + + align:start position:0% +know natural +components + + align:start position:0% +components + + + align:start position:0% +components +but they're also + + align:start position:0% +but they're also + + + align:start position:0% +but they're also +you can start to see this looks a little + + align:start position:0% +you can start to see this looks a little + + + align:start position:0% +you can start to see this looks a little +bit like the bucky balls and bucky tubes + + align:start position:0% +bit like the bucky balls and bucky tubes + + + align:start position:0% +bit like the bucky balls and bucky tubes +that we talked about when we were + + align:start position:0% +that we talked about when we were + + + align:start position:0% +that we talked about when we were +talking about molecular + + align:start position:0% +talking about molecular + + + align:start position:0% +talking about molecular +uh type transistors + + align:start position:0% +uh type transistors + + + align:start position:0% +uh type transistors +so the possibility of mining the + + align:start position:0% +so the possibility of mining the + + + align:start position:0% +so the possibility of mining the +biosphere for these for enzymes that act + + align:start position:0% +biosphere for these for enzymes that act + + + align:start position:0% +biosphere for these for enzymes that act +to synthesize or degrade this class of + + align:start position:0% +to synthesize or degrade this class of + + + align:start position:0% +to synthesize or degrade this class of +just an example we could list many + + align:start position:0% +just an example we could list many + + + align:start position:0% +just an example we could list many +others but the the part of it is just to + + align:start position:0% +others but the the part of it is just to + + + align:start position:0% +others but the the part of it is just to +dream to imagine what it is you would + + align:start position:0% +dream to imagine what it is you would + + + align:start position:0% +dream to imagine what it is you would +like to find out there + + align:start position:0% +like to find out there + + + align:start position:0% +like to find out there +and if there's an abundant + + align:start position:0% +and if there's an abundant + + + align:start position:0% +and if there's an abundant +source of it + + align:start position:0% +source of it + + + align:start position:0% +source of it +um + + align:start position:0% +um + + + align:start position:0% +um +then then uh you should be able to + + align:start position:0% +then then uh you should be able to + + + align:start position:0% +then then uh you should be able to +abundant sources of say the compound in + + align:start position:0% +abundant sources of say the compound in + + + align:start position:0% +abundant sources of say the compound in +this case you should be able to find a + + align:start position:0% +this case you should be able to find a + + + align:start position:0% +this case you should be able to find a +a microorganism an enzyme that goes with + + align:start position:0% +a microorganism an enzyme that goes with + + + align:start position:0% +a microorganism an enzyme that goes with +that because there's a truly phenomenal + + align:start position:0% +that because there's a truly phenomenal + + + align:start position:0% +that because there's a truly phenomenal +amount of diversity + + align:start position:0% +amount of diversity + + + align:start position:0% +amount of diversity +the other asp the other another very + + align:start position:0% +the other asp the other another very + + + align:start position:0% +the other asp the other another very +important global consideration rather + + align:start position:0% +important global consideration rather + + + align:start position:0% +important global consideration rather +than just mining it for new tools + + align:start position:0% +than just mining it for new tools + + + align:start position:0% +than just mining it for new tools +is thinking about ways that either we + + align:start position:0% +is thinking about ways that either we + + + align:start position:0% +is thinking about ways that either we +could engineer or accidentally mess up + + align:start position:0% +could engineer or accidentally mess up + + + align:start position:0% +could engineer or accidentally mess up +our entire planet um + + align:start position:0% +our entire planet um + + + align:start position:0% +our entire planet um +as we are could be doing with global + + align:start position:0% +as we are could be doing with global + + + align:start position:0% +as we are could be doing with global +warming or could do + + align:start position:0% + + + + align:start position:0% + +and perhaps it's naive to think that we + + align:start position:0% +and perhaps it's naive to think that we + + + align:start position:0% +and perhaps it's naive to think that we +actually are having such a big effect + + align:start position:0% +actually are having such a big effect + + + align:start position:0% +actually are having such a big effect +because we know that global warming + + align:start position:0% +because we know that global warming + + + align:start position:0% +because we know that global warming +changes periodically over + + align:start position:0% +changes periodically over + + + align:start position:0% +changes periodically over +millennia + + align:start position:0% + + + + align:start position:0% + +but it is it is very clear from the + + align:start position:0% +but it is it is very clear from the + + + align:start position:0% +but it is it is very clear from the +record that + + align:start position:0% +record that + + + align:start position:0% +record that +just exactly how much carbon dioxide we + + align:start position:0% +just exactly how much carbon dioxide we + + + align:start position:0% +just exactly how much carbon dioxide we +are releasing and it makes sense + + align:start position:0% +are releasing and it makes sense + + + align:start position:0% +are releasing and it makes sense +that it's consistent with the kind of + + align:start position:0% +that it's consistent with the kind of + + + align:start position:0% +that it's consistent with the kind of +temperature changes that have been + + align:start position:0% +temperature changes that have been + + + align:start position:0% +temperature changes that have been +observed since the industrial revolution + + align:start position:0% +observed since the industrial revolution + + + align:start position:0% +observed since the industrial revolution +in any case when you look at uh + + align:start position:0% +in any case when you look at uh + + + align:start position:0% +in any case when you look at uh +in particular + + align:start position:0% +in particular + + + align:start position:0% +in particular +the southern ocean + + align:start position:0% +the southern ocean + + + align:start position:0% +the southern ocean +up at the top of slide 27 you can see + + align:start position:0% +up at the top of slide 27 you can see + + + align:start position:0% +up at the top of slide 27 you can see +there's a few places in particular + + align:start position:0% +there's a few places in particular + + + align:start position:0% +there's a few places in particular +southern ocean seems like it's a prime + + align:start position:0% +southern ocean seems like it's a prime + + + align:start position:0% +southern ocean seems like it's a prime +candidate where you have high nutrients + + align:start position:0% +candidate where you have high nutrients + + + align:start position:0% +candidate where you have high nutrients +but low chlorophyll you say well why + + align:start position:0% +but low chlorophyll you say well why + + + align:start position:0% +but low chlorophyll you say well why +would you have high nutrients but very + + align:start position:0% +would you have high nutrients but very + + + align:start position:0% +would you have high nutrients but very +little uh you know of the + + align:start position:0% +little uh you know of the + + + align:start position:0% +little uh you know of the +chlorophyll around + + align:start position:0% +chlorophyll around + + + align:start position:0% +chlorophyll around +uh that you would which which is a tip + + align:start position:0% +uh that you would which which is a tip + + + align:start position:0% +uh that you would which which is a tip +off that you have of the photosynthetic + + align:start position:0% +off that you have of the photosynthetic + + + align:start position:0% +off that you have of the photosynthetic +bacteria + + align:start position:0% +bacteria + + + align:start position:0% +bacteria +and the reason is that you have a + + align:start position:0% +and the reason is that you have a + + + align:start position:0% +and the reason is that you have a +limitation of some micronutrient + + align:start position:0% +limitation of some micronutrient + + + align:start position:0% +limitation of some micronutrient +micronutrient means it's not needed in + + align:start position:0% +micronutrient means it's not needed in + + + align:start position:0% +micronutrient means it's not needed in +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know the vast quantities you need + + align:start position:0% +you know the vast quantities you need + + + align:start position:0% +you know the vast quantities you need +nitrogen phosphorus carbon oxygen and so + + align:start position:0% +nitrogen phosphorus carbon oxygen and so + + + align:start position:0% +nitrogen phosphorus carbon oxygen and so +on + + align:start position:0% +on + + + align:start position:0% +on +so iron typically is the limiting + + align:start position:0% +so iron typically is the limiting + + + align:start position:0% +so iron typically is the limiting +micronutrient in the southern ocean and + + align:start position:0% +micronutrient in the southern ocean and + + + align:start position:0% +micronutrient in the southern ocean and +so there are actually have been little + + align:start position:0% +so there are actually have been little + + + align:start position:0% +so there are actually have been little +pilot experiments to drop iron off the + + align:start position:0% +pilot experiments to drop iron off the + + + align:start position:0% +pilot experiments to drop iron off the +backs of huge tankers + + align:start position:0% +backs of huge tankers + + + align:start position:0% +backs of huge tankers +and there are now at least seven patents + + align:start position:0% +and there are now at least seven patents + + + align:start position:0% +and there are now at least seven patents +that have been filed on doing this in + + align:start position:0% +that have been filed on doing this in + + + align:start position:0% +that have been filed on doing this in +order to balance out + + align:start position:0% +order to balance out + + + align:start position:0% +order to balance out +carbon credits for different nations + + align:start position:0% +carbon credits for different nations + + + align:start position:0% +carbon credits for different nations +this is potentially a very big + + align:start position:0% +this is potentially a very big + + + align:start position:0% +this is potentially a very big +bit of terrestrial engineering that + + align:start position:0% +bit of terrestrial engineering that + + + align:start position:0% +bit of terrestrial engineering that +might happen that involves trying to + + align:start position:0% +might happen that involves trying to + + + align:start position:0% +might happen that involves trying to +change + + align:start position:0% +change + + + align:start position:0% +change +phytoplankton + + align:start position:0% +phytoplankton + + + align:start position:0% +phytoplankton +and as this line here begins to point + + align:start position:0% +and as this line here begins to point + + + align:start position:0% +and as this line here begins to point +out even though phytoplankton are only + + align:start position:0% +out even though phytoplankton are only + + + align:start position:0% +out even though phytoplankton are only +one percent of the total global biomass + + align:start position:0% +one percent of the total global biomass + + + align:start position:0% +one percent of the total global biomass +it's about 50 of the carbon fixation + + align:start position:0% + + + + align:start position:0% + +what is the source of this 50-fold + + align:start position:0% +what is the source of this 50-fold + + + align:start position:0% +what is the source of this 50-fold +anomaly why is it that even though it's + + align:start position:0% +anomaly why is it that even though it's + + + align:start position:0% +anomaly why is it that even though it's +doing + + align:start position:0% + + + + align:start position:0% + +you know how is it doing 50 of carbon + + align:start position:0% +you know how is it doing 50 of carbon + + + align:start position:0% +you know how is it doing 50 of carbon +fixation and what's happening is a lot + + align:start position:0% +fixation and what's happening is a lot + + + align:start position:0% +fixation and what's happening is a lot +of the carbon is going right back out uh + + align:start position:0% +of the carbon is going right back out uh + + + align:start position:0% +of the carbon is going right back out uh +after being fixed instead of settling to + + align:start position:0% +after being fixed instead of settling to + + + align:start position:0% +after being fixed instead of settling to +the bottom of the ocean and never + + align:start position:0% +the bottom of the ocean and never + + + align:start position:0% +the bottom of the ocean and never +bothering us again + + align:start position:0% + + + + align:start position:0% + +it gets + + align:start position:0% +it gets + + + align:start position:0% +it gets +returned and the exact modeling of that + + align:start position:0% +returned and the exact modeling of that + + + align:start position:0% +returned and the exact modeling of that +requires a much deeper knowledge + + align:start position:0% +requires a much deeper knowledge + + + align:start position:0% +requires a much deeper knowledge +of exactly what organisms are present in + + align:start position:0% +of exactly what organisms are present in + + + align:start position:0% +of exactly what organisms are present in +the ocean + + align:start position:0% +the ocean + + + align:start position:0% +the ocean +one of the problems of this however is a + + align:start position:0% +one of the problems of this however is a + + + align:start position:0% +one of the problems of this however is a +genomic + + align:start position:0% +genomic + + + align:start position:0% +genomic +problem in a certain sense uh + + align:start position:0% +problem in a certain sense uh + + + align:start position:0% +problem in a certain sense uh +which is that very few of these + + align:start position:0% +which is that very few of these + + + align:start position:0% +which is that very few of these +organisms + + align:start position:0% +organisms + + + align:start position:0% +organisms +can be cultivated in a laboratory + + align:start position:0% +can be cultivated in a laboratory + + + align:start position:0% +can be cultivated in a laboratory +on the order of 99.9 + + align:start position:0% +on the order of 99.9 + + + align:start position:0% +on the order of 99.9 +of the organisms you sample from the + + align:start position:0% +of the organisms you sample from the + + + align:start position:0% +of the organisms you sample from the +ocean or from the soil a number of + + align:start position:0% +ocean or from the soil a number of + + + align:start position:0% +ocean or from the soil a number of +different environments + + align:start position:0% +different environments + + + align:start position:0% +different environments +do not grow well in the laboratory + + align:start position:0% +do not grow well in the laboratory + + + align:start position:0% +do not grow well in the laboratory +so if you were to study them + + align:start position:0% +so if you were to study them + + + align:start position:0% +so if you were to study them +some people are feeling that the best + + align:start position:0% +some people are feeling that the best + + + align:start position:0% +some people are feeling that the best +route to studying them is going directly + + align:start position:0% +route to studying them is going directly + + + align:start position:0% +route to studying them is going directly +for + + align:start position:0% +for + + + align:start position:0% +for +looking at their genomes without + + align:start position:0% +looking at their genomes without + + + align:start position:0% +looking at their genomes without +necessarily being able to grow them in + + align:start position:0% +necessarily being able to grow them in + + + align:start position:0% +necessarily being able to grow them in +the laboratory + + align:start position:0% + + + + align:start position:0% + +now when we talk about this this problem + + align:start position:0% +now when we talk about this this problem + + + align:start position:0% +now when we talk about this this problem +of + + align:start position:0% +of + + + align:start position:0% +of +even if we fertilize the oceans and uh + + align:start position:0% +even if we fertilize the oceans and uh + + + align:start position:0% +even if we fertilize the oceans and uh +and you know we can model this whole + + align:start position:0% +and you know we can model this whole + + + align:start position:0% +and you know we can model this whole +procedure we'll go into details but uh + + align:start position:0% + + + + align:start position:0% + +if there are predators there that that + + align:start position:0% +if there are predators there that that + + + align:start position:0% +if there are predators there that that +take the fixed carbon + + align:start position:0% +take the fixed carbon + + + align:start position:0% +take the fixed carbon +and turn it back into carbon dioxide you + + align:start position:0% +and turn it back into carbon dioxide you + + + align:start position:0% +and turn it back into carbon dioxide you +want to be able to monitor that now of + + align:start position:0% +want to be able to monitor that now of + + + align:start position:0% +want to be able to monitor that now of +course the ocean is a large complex + + align:start position:0% +course the ocean is a large complex + + + align:start position:0% +course the ocean is a large complex +set of prokaryotic + + align:start position:0% +set of prokaryotic + + + align:start position:0% +set of prokaryotic +autotrophs that is say photosynthetic + + align:start position:0% +autotrophs that is say photosynthetic + + + align:start position:0% +autotrophs that is say photosynthetic +bacteria and eukaryotic potential + + align:start position:0% +bacteria and eukaryotic potential + + + align:start position:0% +bacteria and eukaryotic potential +bacteria and prokaryotic and eukaryotic + + align:start position:0% +bacteria and prokaryotic and eukaryotic + + + align:start position:0% +bacteria and prokaryotic and eukaryotic +uh predators + + align:start position:0% +uh predators + + + align:start position:0% +uh predators +um + + align:start position:0% +um + + + align:start position:0% +um +of various sorts + + align:start position:0% +of various sorts + + + align:start position:0% +of various sorts +and + + align:start position:0% +and + + + align:start position:0% +and +this is what i think one of the more + + align:start position:0% +this is what i think one of the more + + + align:start position:0% +this is what i think one of the more +interesting predator prey um + + align:start position:0% + + + + align:start position:0% + +differential equation models it's very + + align:start position:0% +differential equation models it's very + + + align:start position:0% +differential equation models it's very +it's almost the same as many of the + + align:start position:0% +it's almost the same as many of the + + + align:start position:0% +it's almost the same as many of the +other different equations that we did + + align:start position:0% +other different equations that we did + + + align:start position:0% +other different equations that we did +from from the first lecture on on + + align:start position:0% +from from the first lecture on on + + + align:start position:0% +from from the first lecture on on +growth we did the logistic equation some + + align:start position:0% +growth we did the logistic equation some + + + align:start position:0% +growth we did the logistic equation some +of the ones we did on repressor function + + align:start position:0% +of the ones we did on repressor function + + + align:start position:0% +of the ones we did on repressor function +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +but things kind of interesting about + + align:start position:0% +but things kind of interesting about + + + align:start position:0% +but things kind of interesting about +this one is it's not + + align:start position:0% +this one is it's not + + + align:start position:0% +this one is it's not +simply a + + align:start position:0% +simply a + + + align:start position:0% +simply a +a + + align:start position:0% +a + + + align:start position:0% +a +single cell bacteria + + align:start position:0% +single cell bacteria + + + align:start position:0% +single cell bacteria +being eaten by a single cell heterotroph + + align:start position:0% +being eaten by a single cell heterotroph + + + align:start position:0% +being eaten by a single cell heterotroph +single you know let's say a blue green + + align:start position:0% +single you know let's say a blue green + + + align:start position:0% +single you know let's say a blue green +algae being in by a single cell + + align:start position:0% +algae being in by a single cell + + + align:start position:0% +algae being in by a single cell +heterotroph here you they're both + + align:start position:0% +heterotroph here you they're both + + + align:start position:0% +heterotroph here you they're both +multicellular uh they're sort of the + + align:start position:0% +multicellular uh they're sort of the + + + align:start position:0% +multicellular uh they're sort of the +minimal multicellular but because + + align:start position:0% +minimal multicellular but because + + + align:start position:0% +minimal multicellular but because +they're multi so chlorella is one of the + + align:start position:0% +they're multi so chlorella is one of the + + + align:start position:0% +they're multi so chlorella is one of the +smallest plants the multicellular plants + + align:start position:0% +smallest plants the multicellular plants + + + align:start position:0% +smallest plants the multicellular plants +and + + align:start position:0% +and + + + align:start position:0% +and +brachionas is a + + align:start position:0% +brachionas is a + + + align:start position:0% +brachionas is a +small rotifer + + align:start position:0% + + + + align:start position:0% + +multicellular animal + + align:start position:0% +multicellular animal + + + align:start position:0% +multicellular animal +because they're all cellular though now + + align:start position:0% +because they're all cellular though now + + + align:start position:0% +because they're all cellular though now +you have the demographic mortality + + align:start position:0% +you have the demographic mortality + + + align:start position:0% +you have the demographic mortality +and fecundity of each of these things + + align:start position:0% +and fecundity of each of these things + + + align:start position:0% +and fecundity of each of these things +that has to be modeled in that's the + + align:start position:0% +that has to be modeled in that's the + + + align:start position:0% +that has to be modeled in that's the +m and the lambda for brachionas + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% + + + + align:start position:0% + +this plays into these equations where + + align:start position:0% +this plays into these equations where + + + align:start position:0% +this plays into these equations where +you have here the in the upper uh right + + align:start position:0% +you have here the in the upper uh right + + + align:start position:0% +you have here the in the upper uh right +slide 28 the + + align:start position:0% +slide 28 the + + + align:start position:0% +slide 28 the +rate of change of + + align:start position:0% + + + + align:start position:0% + +nitrogen with respect to time + + align:start position:0% +nitrogen with respect to time + + + align:start position:0% +nitrogen with respect to time +and + + align:start position:0% +and + + + align:start position:0% +and +concentration of corella so nitrogen is + + align:start position:0% +concentration of corella so nitrogen is + + + align:start position:0% +concentration of corella so nitrogen is +in corella is c + + align:start position:0% +in corella is c + + + align:start position:0% +in corella is c +the + + align:start position:0% +the + + + align:start position:0% +the +r is the brachionas + + align:start position:0% +r is the brachionas + + + align:start position:0% +r is the brachionas +and uh + + align:start position:0% + + + + align:start position:0% + +that are reproducing and b are the + + align:start position:0% +that are reproducing and b are the + + + align:start position:0% +that are reproducing and b are the +brachionas which are the total + + align:start position:0% +brachionas which are the total + + + align:start position:0% +brachionas which are the total +and you can see each of these equations + + align:start position:0% +and you can see each of these equations + + + align:start position:0% +and you can see each of these equations +and how it plays out now this is how + + align:start position:0% +and how it plays out now this is how + + + align:start position:0% +and how it plays out now this is how +uh and the way they play it out here is + + align:start position:0% +uh and the way they play it out here is + + + align:start position:0% +uh and the way they play it out here is +you do it by dilution rate delta here + + align:start position:0% +you do it by dilution rate delta here + + + align:start position:0% +you do it by dilution rate delta here +and the dilution rate + + align:start position:0% +and the dilution rate + + + align:start position:0% +and the dilution rate +is shown + + align:start position:0% +is shown + + + align:start position:0% +is shown +along the + + align:start position:0% +along the + + + align:start position:0% +along the +uh + + align:start position:0% + + + + align:start position:0% + +the horizontal x-axis for each of these + + align:start position:0% +the horizontal x-axis for each of these + + + align:start position:0% +the horizontal x-axis for each of these +three plots here + + align:start position:0% +three plots here + + + align:start position:0% +three plots here +and what they're modeling + + align:start position:0% +and what they're modeling + + + align:start position:0% +and what they're modeling +uh is uh on the far left the nitrogen + + align:start position:0% +uh is uh on the far left the nitrogen + + + align:start position:0% +uh is uh on the far left the nitrogen +concentration + + align:start position:0% +concentration + + + align:start position:0% +concentration +uh + + align:start position:0% + + + + align:start position:0% + +as a function of dilution rate and you + + align:start position:0% +as a function of dilution rate and you + + + align:start position:0% +as a function of dilution rate and you +can see you get these different uh + + align:start position:0% + + + + align:start position:0% + +different sectors of behavior + + align:start position:0% +different sectors of behavior + + + align:start position:0% +different sectors of behavior +when you look at the corella this is the + + align:start position:0% +when you look at the corella this is the + + + align:start position:0% +when you look at the corella this is the +green + + align:start position:0% +green + + + align:start position:0% +green +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the photosynthetic multicellular + + align:start position:0% +the photosynthetic multicellular + + + align:start position:0% +the photosynthetic multicellular +organism in units of millions of cells + + align:start position:0% +organism in units of millions of cells + + + align:start position:0% +organism in units of millions of cells +per milliliter that can take different + + align:start position:0% +per milliliter that can take different + + + align:start position:0% +per milliliter that can take different +uh + + align:start position:0% +uh + + + align:start position:0% +uh +there's a you can take different + + align:start position:0% +there's a you can take different + + + align:start position:0% +there's a you can take different +pathways here um + + align:start position:0% +pathways here um + + + align:start position:0% +pathways here um +where as a function of dilution rate you + + align:start position:0% +where as a function of dilution rate you + + + align:start position:0% +where as a function of dilution rate you +get this bifurcation where you get a + + align:start position:0% +get this bifurcation where you get a + + + align:start position:0% +get this bifurcation where you get a +huge uh split in the + + align:start position:0% +huge uh split in the + + + align:start position:0% +huge uh split in the +possible uh + + align:start position:0% +possible uh + + + align:start position:0% +possible uh +concentrations of corella + + align:start position:0% +concentrations of corella + + + align:start position:0% +concentrations of corella +is the one curve and the brachionas + + align:start position:0% +is the one curve and the brachionas + + + align:start position:0% +is the one curve and the brachionas +the predator is the other curve this + + align:start position:0% +the predator is the other curve this + + + align:start position:0% +the predator is the other curve this +kind of bifurcation is the sort of thing + + align:start position:0% +kind of bifurcation is the sort of thing + + + align:start position:0% +kind of bifurcation is the sort of thing +we talked about + + align:start position:0% +we talked about + + + align:start position:0% +we talked about +earlier in both from the logistic + + align:start position:0% +earlier in both from the logistic + + + align:start position:0% +earlier in both from the logistic +equation + + align:start position:0% +equation + + + align:start position:0% +equation +and + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +what in the upper right hand your here's + + align:start position:0% +what in the upper right hand your here's + + + align:start position:0% +what in the upper right hand your here's +our friend the coefficient of variation + + align:start position:0% +our friend the coefficient of variation + + + align:start position:0% +our friend the coefficient of variation +in percent ranging from 0 to 8 80 or so + + align:start position:0% +in percent ranging from 0 to 8 80 or so + + + align:start position:0% +in percent ranging from 0 to 8 80 or so +on the vertical axis and the dilution + + align:start position:0% +on the vertical axis and the dilution + + + align:start position:0% +on the vertical axis and the dilution +rate and again you can see + + align:start position:0% +rate and again you can see + + + align:start position:0% +rate and again you can see +that you get a peak in the dilution rate + + align:start position:0% +that you get a peak in the dilution rate + + + align:start position:0% +that you get a peak in the dilution rate +at around seven five so these are these + + align:start position:0% +at around seven five so these are these + + + align:start position:0% +at around seven five so these are these +are the bottom two models in the upper + + align:start position:0% +are the bottom two models in the upper + + + align:start position:0% +are the bottom two models in the upper +right is a data + + align:start position:0% +right is a data + + + align:start position:0% +right is a data +um but you can actually see when you run + + align:start position:0% +um but you can actually see when you run + + + align:start position:0% +um but you can actually see when you run +real chlorella and brachionas in here + + align:start position:0% +real chlorella and brachionas in here + + + align:start position:0% +real chlorella and brachionas in here +but you do get a peak just as you would + + align:start position:0% +but you do get a peak just as you would + + + align:start position:0% +but you do get a peak just as you would +predict this kind of bifurcation now + + align:start position:0% +predict this kind of bifurcation now + + + align:start position:0% +predict this kind of bifurcation now +with kinetic modeling + + align:start position:0% +with kinetic modeling + + + align:start position:0% +with kinetic modeling +that's due to + + align:start position:0% +that's due to + + + align:start position:0% +that's due to +where you get + + align:start position:0% +where you get + + + align:start position:0% +where you get +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +behavior in this + + align:start position:0% +behavior in this + + + align:start position:0% +behavior in this +complicated there's a fairly simple + + align:start position:0% +complicated there's a fairly simple + + + align:start position:0% +complicated there's a fairly simple +model ecosystem where you just have two + + align:start position:0% +model ecosystem where you just have two + + + align:start position:0% +model ecosystem where you just have two +species + + align:start position:0% +species + + + align:start position:0% +species +in the ocean of course you have a lot + + align:start position:0% +in the ocean of course you have a lot + + + align:start position:0% +in the ocean of course you have a lot +more + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +that's out in the wide world where you + + align:start position:0% +that's out in the wide world where you + + + align:start position:0% +that's out in the wide world where you +have 10 to the 26 cells + + align:start position:0% +have 10 to the 26 cells + + + align:start position:0% +have 10 to the 26 cells +but inside every one of us in this room + + align:start position:0% +but inside every one of us in this room + + + align:start position:0% +but inside every one of us in this room +no offense but there are about uh + + align:start position:0% +no offense but there are about uh + + + align:start position:0% +no offense but there are about uh +ten times as many non-human cells in + + align:start position:0% +ten times as many non-human cells in + + + align:start position:0% +ten times as many non-human cells in +each of us as there are human cells + + align:start position:0% +each of us as there are human cells + + + align:start position:0% +each of us as there are human cells +and we have our own ecology + + align:start position:0% +and we have our own ecology + + + align:start position:0% +and we have our own ecology +and there is a literature where + + align:start position:0% +and there is a literature where + + + align:start position:0% +and there is a literature where +you know certain organisms we know cause + + align:start position:0% +you know certain organisms we know cause + + + align:start position:0% +you know certain organisms we know cause +diseases and they're put into one + + align:start position:0% +diseases and they're put into one + + + align:start position:0% +diseases and they're put into one +category infectious diseases but then + + align:start position:0% +category infectious diseases but then + + + align:start position:0% +category infectious diseases but then +there's another set that takes some time + + align:start position:0% +there's another set that takes some time + + + align:start position:0% +there's another set that takes some time +to sort out and you can see here are + + align:start position:0% +to sort out and you can see here are + + + align:start position:0% +to sort out and you can see here are +candidate diseases and candidate + + align:start position:0% +candidate diseases and candidate + + + align:start position:0% +candidate diseases and candidate +organisms and all these little bars that + + align:start position:0% +organisms and all these little bars that + + + align:start position:0% +organisms and all these little bars that +are going in here are uh + + align:start position:0% +are going in here are uh + + + align:start position:0% +are going in here are uh +you know references that you can look up + + align:start position:0% +you know references that you can look up + + + align:start position:0% +you know references that you can look up +where uh maybe it's not an airtight case + + align:start position:0% +where uh maybe it's not an airtight case + + + align:start position:0% +where uh maybe it's not an airtight case +yet or maybe it's not even maybe this + + align:start position:0% +yet or maybe it's not even maybe this + + + align:start position:0% +yet or maybe it's not even maybe this +controversial or discredited at this + + align:start position:0% +controversial or discredited at this + + + align:start position:0% +controversial or discredited at this +point but these are links where + + align:start position:0% +point but these are links where + + + align:start position:0% +point but these are links where +eventually this will be called an + + align:start position:0% +eventually this will be called an + + + align:start position:0% +eventually this will be called an +infectious disease helicobacter hydride + + align:start position:0% +infectious disease helicobacter hydride + + + align:start position:0% +infectious disease helicobacter hydride +causes chemicals which i think that's + + align:start position:0% +causes chemicals which i think that's + + + align:start position:0% +causes chemicals which i think that's +basically already accepted + + align:start position:0% + + + + align:start position:0% + +some australian doctor named marshall + + align:start position:0% +some australian doctor named marshall + + + align:start position:0% +some australian doctor named marshall +decided to drink a bunch of helicobacter + + align:start position:0% +decided to drink a bunch of helicobacter + + + align:start position:0% +decided to drink a bunch of helicobacter +to prove to his colleagues he didn't + + align:start position:0% +to prove to his colleagues he didn't + + + align:start position:0% +to prove to his colleagues he didn't +believe any stomach ulcers were caused + + align:start position:0% +believe any stomach ulcers were caused + + + align:start position:0% +believe any stomach ulcers were caused +by the back but much less all of them + + align:start position:0% +by the back but much less all of them + + + align:start position:0% +by the back but much less all of them +and uh he drank it through himself again + + align:start position:0% +and uh he drank it through himself again + + + align:start position:0% +and uh he drank it through himself again +and he caused stomach ulcers + + align:start position:0% +and he caused stomach ulcers + + + align:start position:0% +and he caused stomach ulcers +in himself + + align:start position:0% +in himself + + + align:start position:0% +in himself +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and hopefully um none of you will + + align:start position:0% +and hopefully um none of you will + + + align:start position:0% +and hopefully um none of you will +volunteer to do similar things with some + + align:start position:0% +volunteer to do similar things with some + + + align:start position:0% +volunteer to do similar things with some +of these other uh + + align:start position:0% +of these other uh + + + align:start position:0% +of these other uh +nasty guys here because i think + + align:start position:0% +nasty guys here because i think + + + align:start position:0% +nasty guys here because i think +some of the lists of things that they + + align:start position:0% +some of the lists of things that they + + + align:start position:0% +some of the lists of things that they +cause are a little more serious and + + align:start position:0% +cause are a little more serious and + + + align:start position:0% +cause are a little more serious and +stomach ulcers and the cures are a + + align:start position:0% +stomach ulcers and the cures are a + + + align:start position:0% +stomach ulcers and the cures are a +little less obvious than the cures for a + + align:start position:0% +little less obvious than the cures for a + + + align:start position:0% +little less obvious than the cures for a +gram-negative bacterium like + + align:start position:0% +gram-negative bacterium like + + + align:start position:0% +gram-negative bacterium like +helicobacter + + align:start position:0% +helicobacter + + + align:start position:0% +helicobacter +um + + align:start position:0% +um + + + align:start position:0% +um +there have been various efforts + + align:start position:0% +there have been various efforts + + + align:start position:0% +there have been various efforts +started + + align:start position:0% +started + + + align:start position:0% +started +to actually mine you know what's the + + align:start position:0% +to actually mine you know what's the + + + align:start position:0% +to actually mine you know what's the +connection with uh genomics and + + align:start position:0% +connection with uh genomics and + + + align:start position:0% +connection with uh genomics and +computational biology to mine the + + align:start position:0% +computational biology to mine the + + + align:start position:0% +computational biology to mine the +transcriptome + + align:start position:0% +transcriptome + + + align:start position:0% +transcriptome +uh for evidence of these + + align:start position:0% +uh for evidence of these + + + align:start position:0% +uh for evidence of these +you can look for bacteria very easily + + align:start position:0% +you can look for bacteria very easily + + + align:start position:0% +you can look for bacteria very easily +because they have ribosomal rna + + align:start position:0% +because they have ribosomal rna + + + align:start position:0% +because they have ribosomal rna +components which you can pcr viruses are + + align:start position:0% +components which you can pcr viruses are + + + align:start position:0% +components which you can pcr viruses are +more complicated because they're not + + align:start position:0% +more complicated because they're not + + + align:start position:0% +more complicated because they're not +conserved + + align:start position:0% +conserved + + + align:start position:0% +conserved +uh + + align:start position:0% +uh + + + align:start position:0% +uh +or they don't have any universally + + align:start position:0% +or they don't have any universally + + + align:start position:0% +or they don't have any universally +conserved element like rival rna + + align:start position:0% +conserved element like rival rna + + + align:start position:0% +conserved element like rival rna +but they've been efforts to take uh + + align:start position:0% +but they've been efforts to take uh + + + align:start position:0% +but they've been efforts to take uh +look for what's present in the human + + align:start position:0% +look for what's present in the human + + + align:start position:0% +look for what's present in the human +transcriptome that's not present in the + + align:start position:0% +transcriptome that's not present in the + + + align:start position:0% +transcriptome that's not present in the +human genome human genome is something + + align:start position:0% +human genome human genome is something + + + align:start position:0% +human genome human genome is something +you know + + align:start position:0% +you know + + + align:start position:0% +you know +highly purified and cloned and so forth + + align:start position:0% +highly purified and cloned and so forth + + + align:start position:0% +highly purified and cloned and so forth +while the transcriptome + + align:start position:0% +while the transcriptome + + + align:start position:0% +while the transcriptome +is uh + + align:start position:0% +is uh + + + align:start position:0% +is uh +you know it's whatever cells they grind + + align:start position:0% +you know it's whatever cells they grind + + + align:start position:0% +you know it's whatever cells they grind +ground up that day and they and indeed + + align:start position:0% +ground up that day and they and indeed + + + align:start position:0% +ground up that day and they and indeed +lurking in there are many of these uh + + align:start position:0% +lurking in there are many of these uh + + + align:start position:0% +lurking in there are many of these uh +hepatitis papilloma antibar virus um + + align:start position:0% +hepatitis papilloma antibar virus um + + + align:start position:0% +hepatitis papilloma antibar virus um +retroviral like elements which are not + + align:start position:0% +retroviral like elements which are not + + + align:start position:0% +retroviral like elements which are not +present in the human genome as yet human + + align:start position:0% +present in the human genome as yet human + + + align:start position:0% +present in the human genome as yet human +genome is not completely finished so + + align:start position:0% +genome is not completely finished so + + + align:start position:0% +genome is not completely finished so +that's still a escape clause but + + align:start position:0% +that's still a escape clause but + + + align:start position:0% +that's still a escape clause but +basically + + align:start position:0% +basically + + + align:start position:0% +basically +these are smoking guns for at least + + align:start position:0% +these are smoking guns for at least + + + align:start position:0% +these are smoking guns for at least +commensals + + align:start position:0% +commensals + + + align:start position:0% +commensals +micro organisms and viruses that are + + align:start position:0% +micro organisms and viruses that are + + + align:start position:0% +micro organisms and viruses that are +living in + + align:start position:0% +living in + + + align:start position:0% +living in +tissues then some of them may be tissue + + align:start position:0% +tissues then some of them may be tissue + + + align:start position:0% +tissues then some of them may be tissue +specific + + align:start position:0% +specific + + + align:start position:0% +specific +some of them subset may actually cause + + align:start position:0% +some of them subset may actually cause + + + align:start position:0% +some of them subset may actually cause +disease and that's the whole problem + + align:start position:0% +disease and that's the whole problem + + + align:start position:0% +disease and that's the whole problem +then is sorting out cause and effect we + + align:start position:0% +then is sorting out cause and effect we + + + align:start position:0% +then is sorting out cause and effect we +know how + + align:start position:0% +know how + + + align:start position:0% +know how +how it's been done + + align:start position:0% +how it's been done + + + align:start position:0% +how it's been done +heroically with helicobacter pylori but + + align:start position:0% +heroically with helicobacter pylori but + + + align:start position:0% +heroically with helicobacter pylori but +how do we do it with the other ones some + + align:start position:0% +how do we do it with the other ones some + + + align:start position:0% +how do we do it with the other ones some +of them will have tissue culture models + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +at the time this slide was done + + align:start position:0% +at the time this slide was done + + + align:start position:0% +at the time this slide was done +so + + align:start position:0% +so + + + align:start position:0% +so +this is just uh + + align:start position:0% +this is just uh + + + align:start position:0% +this is just uh +illustrating kind of the flow of uh + + align:start position:0% +illustrating kind of the flow of uh + + + align:start position:0% +illustrating kind of the flow of uh +nucleic acid information that comes in + + align:start position:0% +nucleic acid information that comes in + + + align:start position:0% +nucleic acid information that comes in +about + + align:start position:0% +about + + + align:start position:0% +about +uh you know it was capable of being + + align:start position:0% +uh you know it was capable of being + + + align:start position:0% +uh you know it was capable of being +mined for new microorganisms new viruses + + align:start position:0% +mined for new microorganisms new viruses + + + align:start position:0% +mined for new microorganisms new viruses +that might be present in a + + align:start position:0% +that might be present in a + + + align:start position:0% +that might be present in a +tissue-specific fashion might be + + align:start position:0% +tissue-specific fashion might be + + + align:start position:0% +tissue-specific fashion might be +pathogens + + align:start position:0% +pathogens + + + align:start position:0% +pathogens +this is some of the most popular + + align:start position:0% +this is some of the most popular + + + align:start position:0% +this is some of the most popular +sequences from which we're mining + + align:start position:0% +sequences from which we're mining + + + align:start position:0% +sequences from which we're mining +obviously + + align:start position:0% +obviously + + + align:start position:0% +obviously +human + + align:start position:0% +human + + + align:start position:0% +human +was popular at the time this was done + + align:start position:0% +was popular at the time this was done + + + align:start position:0% +was popular at the time this was done +because human genome was in place here's + + align:start position:0% +because human genome was in place here's + + + align:start position:0% +because human genome was in place here's +brachionas our friend which was pretty + + align:start position:0% +brachionas our friend which was pretty + + + align:start position:0% +brachionas our friend which was pretty +high up on this list considering most of + + align:start position:0% +high up on this list considering most of + + + align:start position:0% +high up on this list considering most of +you probably didn't hear about greek + + align:start position:0% +you probably didn't hear about greek + + + align:start position:0% +you probably didn't hear about greek +units before this lecture now you've + + align:start position:0% +units before this lecture now you've + + + align:start position:0% +units before this lecture now you've +heard of it twice + + align:start position:0% +heard of it twice + + + align:start position:0% +heard of it twice +it just was a spurt in uh sequencing + + align:start position:0% +it just was a spurt in uh sequencing + + + align:start position:0% +it just was a spurt in uh sequencing +interest and of course hiv is the winner + + align:start position:0% +interest and of course hiv is the winner + + + align:start position:0% +interest and of course hiv is the winner +year after year because of the + + align:start position:0% +year after year because of the + + + align:start position:0% +year after year because of the +importance of resequencing it for + + align:start position:0% +importance of resequencing it for + + + align:start position:0% +importance of resequencing it for +for new mutations and it really has a + + align:start position:0% +for new mutations and it really has a + + + align:start position:0% +for new mutations and it really has a +record number of new mutations + + align:start position:0% +record number of new mutations + + + align:start position:0% +record number of new mutations +and + + align:start position:0% +and + + + align:start position:0% +and +we've talked about hiv uh + + align:start position:0% +we've talked about hiv uh + + + align:start position:0% +we've talked about hiv uh +from different from a variety of + + align:start position:0% +from different from a variety of + + + align:start position:0% +from different from a variety of +different standpoints + + align:start position:0% +different standpoints + + + align:start position:0% +different standpoints +uh one of them you know it's polymerase + + align:start position:0% +uh one of them you know it's polymerase + + + align:start position:0% +uh one of them you know it's polymerase +is proteases drug targets + + align:start position:0% +is proteases drug targets + + + align:start position:0% +is proteases drug targets +and is uh sources of drug resistance + + align:start position:0% +and is uh sources of drug resistance + + + align:start position:0% +and is uh sources of drug resistance +and that you can follow up that that + + align:start position:0% +and that you can follow up that that + + + align:start position:0% +and that you can follow up that that +model you know that sort of atomic scale + + align:start position:0% +model you know that sort of atomic scale + + + align:start position:0% +model you know that sort of atomic scale +protein modeling where you're looking + + align:start position:0% +protein modeling where you're looking + + + align:start position:0% +protein modeling where you're looking +for new drugs well + + align:start position:0% + + + + align:start position:0% + +where the polymerase of the mutant + + align:start position:0% +where the polymerase of the mutant + + + align:start position:0% +where the polymerase of the mutant +polymerase will not be resistant to + + align:start position:0% +polymerase will not be resistant to + + + align:start position:0% +polymerase will not be resistant to +neutron + + align:start position:0% +neutron + + + align:start position:0% +neutron +but you can also monitor the population + + align:start position:0% +but you can also monitor the population + + + align:start position:0% +but you can also monitor the population +scale as + + align:start position:0% +scale as + + + align:start position:0% +scale as +hiv goes through a particular patient or + + align:start position:0% +hiv goes through a particular patient or + + + align:start position:0% +hiv goes through a particular patient or +through a population of patients how + + align:start position:0% +through a population of patients how + + + align:start position:0% +through a population of patients how +does the + + align:start position:0% +does the + + + align:start position:0% +does the +drug resistance change as a function of + + align:start position:0% +drug resistance change as a function of + + + align:start position:0% +drug resistance change as a function of +time here the horizontal axis is in days + + align:start position:0% +time here the horizontal axis is in days + + + align:start position:0% +time here the horizontal axis is in days +up to 30 days + + align:start position:0% +up to 30 days + + + align:start position:0% +up to 30 days +and then the vertical axis + + align:start position:0% +and then the vertical axis + + + align:start position:0% +and then the vertical axis +is the um + + align:start position:0% + + + + align:start position:0% + +the titers of the viruses + + align:start position:0% + + + + align:start position:0% + +and what you have here is um + + align:start position:0% + + + + align:start position:0% + +rates of exponential increase these are + + align:start position:0% +rates of exponential increase these are + + + align:start position:0% +rates of exponential increase these are +all these are on logarithmic scales and + + align:start position:0% +all these are on logarithmic scales and + + + align:start position:0% +all these are on logarithmic scales and +you can't where you're modeling such + + align:start position:0% +you can't where you're modeling such + + + align:start position:0% +you can't where you're modeling such +thing as the + + align:start position:0% +thing as the + + + align:start position:0% +thing as the +clearance to the immune system and so + + align:start position:0% +clearance to the immune system and so + + + align:start position:0% +clearance to the immune system and so +forth originally this virus was thought + + align:start position:0% +forth originally this virus was thought + + + align:start position:0% +forth originally this virus was thought +to be a very slow virus very slowly + + align:start position:0% +to be a very slow virus very slowly + + + align:start position:0% +to be a very slow virus very slowly +replicating virus + + align:start position:0% + + + + align:start position:0% + +almost cryptic and then later was found + + align:start position:0% +almost cryptic and then later was found + + + align:start position:0% +almost cryptic and then later was found +that this is actually a very rapidly + + align:start position:0% +that this is actually a very rapidly + + + align:start position:0% +that this is actually a very rapidly +replicating but an immune system that's + + align:start position:0% +replicating but an immune system that's + + + align:start position:0% +replicating but an immune system that's +very rapidly responding + + align:start position:0% +very rapidly responding + + + align:start position:0% +very rapidly responding +the sort of model print just each of + + align:start position:0% +the sort of model print just each of + + + align:start position:0% +the sort of model print just each of +these models we've gone through has a + + align:start position:0% +these models we've gone through has a + + + align:start position:0% +these models we've gone through has a +set of parameters that it goes along + + align:start position:0% +set of parameters that it goes along + + + align:start position:0% +set of parameters that it goes along +with in certain sense there's quite a + + align:start position:0% +with in certain sense there's quite a + + + align:start position:0% +with in certain sense there's quite a +bit you can learn about a model just by + + align:start position:0% +bit you can learn about a model just by + + + align:start position:0% +bit you can learn about a model just by +seeing what parameters are present or + + align:start position:0% +seeing what parameters are present or + + + align:start position:0% +seeing what parameters are present or +absent before they're experimentally + + align:start position:0% +absent before they're experimentally + + + align:start position:0% +absent before they're experimentally +determined how accurately and so on and + + align:start position:0% +determined how accurately and so on and + + + align:start position:0% +determined how accurately and so on and +sort of model parameters here are + + align:start position:0% +sort of model parameters here are + + + align:start position:0% +sort of model parameters here are +mortality rate of uninfected cd4 plus t + + align:start position:0% +mortality rate of uninfected cd4 plus t + + + align:start position:0% +mortality rate of uninfected cd4 plus t +cells + + align:start position:0% +cells + + + align:start position:0% +cells +same thing for infected cells + + align:start position:0% +same thing for infected cells + + + align:start position:0% +same thing for infected cells +and they're going to have differences + + align:start position:0% +and they're going to have differences + + + align:start position:0% +and they're going to have differences +you can see on the far right if there's + + align:start position:0% +you can see on the far right if there's + + + align:start position:0% +you can see on the far right if there's +a huge difference + + align:start position:0% +a huge difference + + + align:start position:0% +a huge difference +they die at a point a quarter per day + + align:start position:0% +they die at a point a quarter per day + + + align:start position:0% +they die at a point a quarter per day +versus + + align:start position:0% +versus + + + align:start position:0% +versus +5 000 + + align:start position:0% +5 000 + + + align:start position:0% +5 000 +and so on there's rates for + + align:start position:0% +and so on there's rates for + + + align:start position:0% +and so on there's rates for +getting infected rates of virus loss + + align:start position:0% +getting infected rates of virus loss + + + align:start position:0% +getting infected rates of virus loss +production + + align:start position:0% +production + + + align:start position:0% +production +um + + align:start position:0% + + + + align:start position:0% + +threshold value for remission + + align:start position:0% +threshold value for remission + + + align:start position:0% +threshold value for remission +so on and so forth + + align:start position:0% +so on and so forth + + + align:start position:0% +so on and so forth +and these are important + + align:start position:0% +and these are important + + + align:start position:0% +and these are important +parameters + + align:start position:0% +parameters + + + align:start position:0% +parameters +for + + align:start position:0% +for + + + align:start position:0% +for +how + + align:start position:0% +how + + + align:start position:0% +how +the virus population changes within a + + align:start position:0% +the virus population changes within a + + + align:start position:0% +the virus population changes within a +person within population how it spreads + + align:start position:0% +person within population how it spreads + + + align:start position:0% +person within population how it spreads +through the population depends + + align:start position:0% +through the population depends + + + align:start position:0% +through the population depends +on um + + align:start position:0% +on um + + + align:start position:0% +on um +in many cases on the + + align:start position:0% +in many cases on the + + + align:start position:0% +in many cases on the +herd immunity and so forth and we get + + align:start position:0% +herd immunity and so forth and we get + + + align:start position:0% +herd immunity and so forth and we get +into issues of + + align:start position:0% +into issues of + + + align:start position:0% +into issues of +public health + + align:start position:0% + + + + align:start position:0% + +it's + + align:start position:0% +it's + + + align:start position:0% +it's +almost a truism that that most of the + + align:start position:0% + + + + align:start position:0% + +additional quality years of life + + align:start position:0% +additional quality years of life + + + align:start position:0% +additional quality years of life +uh quality adjusted life years here + + align:start position:0% +uh quality adjusted life years here + + + align:start position:0% +uh quality adjusted life years here +qali that we have in the world the fact + + align:start position:0% +qali that we have in the world the fact + + + align:start position:0% +qali that we have in the world the fact +that you know our life expectancy is so + + align:start position:0% +that you know our life expectancy is so + + + align:start position:0% +that you know our life expectancy is so +much longer so forth are mainly public + + align:start position:0% +much longer so forth are mainly public + + + align:start position:0% +much longer so forth are mainly public +health + + align:start position:0% +health + + + align:start position:0% +health +decisions that have been made + + align:start position:0% +decisions that have been made + + + align:start position:0% +decisions that have been made +not so much pharmaceutical + + align:start position:0% + + + + align:start position:0% + +such things as + + align:start position:0% +such things as + + + align:start position:0% +such things as +clean water + + align:start position:0% + + + + align:start position:0% + +has made a huge impact and so we need to + + align:start position:0% +has made a huge impact and so we need to + + + align:start position:0% +has made a huge impact and so we need to +think but + + align:start position:0% +think but + + + align:start position:0% +think but +even when you think about the + + align:start position:0% +even when you think about the + + + align:start position:0% +even when you think about the +pharmaceutical aspects it needs to be + + align:start position:0% +pharmaceutical aspects it needs to be + + + align:start position:0% +pharmaceutical aspects it needs to be +thought in a public health sense and a + + align:start position:0% +thought in a public health sense and a + + + align:start position:0% +thought in a public health sense and a +surprising amount of public health + + align:start position:0% +surprising amount of public health + + + align:start position:0% +surprising amount of public health +officials in even the most developed + + align:start position:0% +officials in even the most developed + + + align:start position:0% +officials in even the most developed +nations maybe + + align:start position:0% +nations maybe + + + align:start position:0% +nations maybe +most of them are do not have formal + + align:start position:0% +most of them are do not have formal + + + align:start position:0% +most of them are do not have formal +education public health and so i urge + + align:start position:0% +education public health and so i urge + + + align:start position:0% +education public health and so i urge +you + + align:start position:0% +you + + + align:start position:0% +you +all to get at least some education in + + align:start position:0% +all to get at least some education in + + + align:start position:0% +all to get at least some education in +this because in this we have you know + + align:start position:0% +this because in this we have you know + + + align:start position:0% +this because in this we have you know +here + + align:start position:0% +here + + + align:start position:0% +here +quan they're trying to build and have + + align:start position:0% +quan they're trying to build and have + + + align:start position:0% +quan they're trying to build and have +built quantitative models not only for + + align:start position:0% +built quantitative models not only for + + + align:start position:0% +built quantitative models not only for +the + + align:start position:0% +the + + + align:start position:0% +the +the kinetics which the disease will go + + align:start position:0% +the kinetics which the disease will go + + + align:start position:0% +the kinetics which the disease will go +through a population or through even + + align:start position:0% +through a population or through even + + + align:start position:0% +through a population or through even +through an individual + + align:start position:0% + + + + align:start position:0% + +but but the way that you make decisions + + align:start position:0% +but but the way that you make decisions + + + align:start position:0% +but but the way that you make decisions +and this is having an impact on the way + + align:start position:0% +and this is having an impact on the way + + + align:start position:0% +and this is having an impact on the way +decisions are + + align:start position:0% +decisions are + + + align:start position:0% +decisions are +how these different uh projects are + + align:start position:0% +how these different uh projects are + + + align:start position:0% +how these different uh projects are +prioritized at any given time you might + + align:start position:0% +prioritized at any given time you might + + + align:start position:0% +prioritized at any given time you might +have hundreds of different candidate + + align:start position:0% +have hundreds of different candidate + + + align:start position:0% +have hundreds of different candidate +vaccines + + align:start position:0% +vaccines + + + align:start position:0% +vaccines +which is one of a major very effective + + align:start position:0% +which is one of a major very effective + + + align:start position:0% +which is one of a major very effective +public health strategy + + align:start position:0% +public health strategy + + + align:start position:0% +public health strategy +and this is the way they prioritize it + + align:start position:0% +and this is the way they prioritize it + + + align:start position:0% +and this is the way they prioritize it +so that level one saves money and it + + align:start position:0% +so that level one saves money and it + + + align:start position:0% +so that level one saves money and it +improves life so that's + + align:start position:0% +improves life so that's + + + align:start position:0% +improves life so that's +almost a no-brainer + + align:start position:0% +almost a no-brainer + + + align:start position:0% +almost a no-brainer +you have different levels we have + + align:start position:0% +you have different levels we have + + + align:start position:0% +you have different levels we have +might cost ten thousand dollars + + align:start position:0% +might cost ten thousand dollars + + + align:start position:0% +might cost ten thousand dollars +or a hundred thousand dollars per + + align:start position:0% +or a hundred thousand dollars per + + + align:start position:0% +or a hundred thousand dollars per +quality adjusted life here to save + + align:start position:0% + + + + align:start position:0% + +and so the level one candidates are + + align:start position:0% +and so the level one candidates are + + + align:start position:0% +and so the level one candidates are +cytomegalovirus and uh therapeutic + + align:start position:0% +cytomegalovirus and uh therapeutic + + + align:start position:0% +cytomegalovirus and uh therapeutic +vaccines which these are not aimed at + + align:start position:0% +vaccines which these are not aimed at + + + align:start position:0% +vaccines which these are not aimed at +infectious + + align:start position:0% +infectious + + + align:start position:0% +infectious +disease for diabetes rheumatoid + + align:start position:0% +disease for diabetes rheumatoid + + + align:start position:0% +disease for diabetes rheumatoid +arthritis multiple sclerosis + + align:start position:0% +arthritis multiple sclerosis + + + align:start position:0% +arthritis multiple sclerosis +various bacterial ones of course hiv was + + align:start position:0% +various bacterial ones of course hiv was + + + align:start position:0% +various bacterial ones of course hiv was +not even a study because it was such a + + align:start position:0% +not even a study because it was such a + + + align:start position:0% +not even a study because it was such a +high prio priority already + + align:start position:0% +high prio priority already + + + align:start position:0% +high prio priority already +within the nih + + align:start position:0% +within the nih + + + align:start position:0% +within the nih +okay + + align:start position:0% + + + + align:start position:0% + +so is there a role for genomics and + + align:start position:0% +so is there a role for genomics and + + + align:start position:0% +so is there a role for genomics and +computational biology the title of this + + align:start position:0% +computational biology the title of this + + + align:start position:0% +computational biology the title of this +course + + align:start position:0% +course + + + align:start position:0% +course +in this vaccine research and development + + align:start position:0% +in this vaccine research and development + + + align:start position:0% +in this vaccine research and development +i think the answer is + + align:start position:0% +i think the answer is + + + align:start position:0% +i think the answer is +yes but it requires a great deal of + + align:start position:0% +yes but it requires a great deal of + + + align:start position:0% +yes but it requires a great deal of +creativity and resourcefulness on on all + + align:start position:0% +creativity and resourcefulness on on all + + + align:start position:0% +creativity and resourcefulness on on all +of your parts + + align:start position:0% +of your parts + + + align:start position:0% +of your parts +there are new opportunities with dna + + align:start position:0% +there are new opportunities with dna + + + align:start position:0% +there are new opportunities with dna +vaccines that where you can have one or + + align:start position:0% +vaccines that where you can have one or + + + align:start position:0% +vaccines that where you can have one or +more dnas + + align:start position:0% +more dnas + + + align:start position:0% +more dnas +shot + + align:start position:0% +shot + + + align:start position:0% +shot +intramuscular or a variety of other + + align:start position:0% +intramuscular or a variety of other + + + align:start position:0% +intramuscular or a variety of other +ways what is delivered by the dna + + align:start position:0% +ways what is delivered by the dna + + + align:start position:0% +ways what is delivered by the dna +vaccine can be + + align:start position:0% +vaccine can be + + + align:start position:0% +vaccine can be +various so-called intracellular vaccines + + align:start position:0% +various so-called intracellular vaccines + + + align:start position:0% +various so-called intracellular vaccines +which can either act through + + align:start position:0% +which can either act through + + + align:start position:0% +which can either act through +cell-mediated immunity or in some other + + align:start position:0% +cell-mediated immunity or in some other + + + align:start position:0% +cell-mediated immunity or in some other +way intracellularly + + align:start position:0% +way intracellularly + + + align:start position:0% +way intracellularly +rnai is a is a rapidly + + align:start position:0% +rnai is a is a rapidly + + + align:start position:0% +rnai is a is a rapidly +emerging + + align:start position:0% +emerging + + + align:start position:0% +emerging +way of + + align:start position:0% +way of + + + align:start position:0% +way of +delivering + + align:start position:0% +delivering + + + align:start position:0% +delivering +things + + align:start position:0% +things + + + align:start position:0% +things +that wouldn't may not be classically + + align:start position:0% +that wouldn't may not be classically + + + align:start position:0% +that wouldn't may not be classically +considered uh therapeutics or vaccines + + align:start position:0% +considered uh therapeutics or vaccines + + + align:start position:0% +considered uh therapeutics or vaccines +the concept of multiplexing you me + + align:start position:0% +the concept of multiplexing you me + + + align:start position:0% +the concept of multiplexing you me +many + + align:start position:0% +many + + + align:start position:0% +many +of us + + align:start position:0% + + + + align:start position:0% + +have received multiple vaccines at a + + align:start position:0% +have received multiple vaccines at a + + + align:start position:0% +have received multiple vaccines at a +time typically every year your flu + + align:start position:0% +time typically every year your flu + + + align:start position:0% +time typically every year your flu +vaccine will have two or three strains + + align:start position:0% +vaccine will have two or three strains + + + align:start position:0% +vaccine will have two or three strains +in it but um as you can see from this + + align:start position:0% +in it but um as you can see from this + + + align:start position:0% +in it but um as you can see from this +middle article the diversity of certain + + align:start position:0% +middle article the diversity of certain + + + align:start position:0% +middle article the diversity of certain +diseases like hiv and influenza almost + + align:start position:0% +diseases like hiv and influenza almost + + + align:start position:0% +diseases like hiv and influenza almost +demand + + align:start position:0% +demand + + + align:start position:0% +demand +attention to the genomics the diversity + + align:start position:0% +attention to the genomics the diversity + + + align:start position:0% +attention to the genomics the diversity +that can occur either from year to year + + align:start position:0% +that can occur either from year to year + + + align:start position:0% +that can occur either from year to year +or throughout the entire + + align:start position:0% +or throughout the entire + + + align:start position:0% +or throughout the entire +global + + align:start position:0% +global + + + align:start position:0% +global +set of viruses + + align:start position:0% +set of viruses + + + align:start position:0% +set of viruses +another opportunity is when we have um + + align:start position:0% +another opportunity is when we have um + + + align:start position:0% +another opportunity is when we have um +vectors for say uh + + align:start position:0% +vectors for say uh + + + align:start position:0% +vectors for say uh +arthropod vectors insect vectors like + + align:start position:0% +arthropod vectors insect vectors like + + + align:start position:0% +arthropod vectors insect vectors like +mosquito and we have uh + + align:start position:0% +mosquito and we have uh + + + align:start position:0% +mosquito and we have uh +opportunities to and to hit malaria at + + align:start position:0% +opportunities to and to hit malaria at + + + align:start position:0% +opportunities to and to hit malaria at +all the different life stages not just + + align:start position:0% +all the different life stages not just + + + align:start position:0% +all the different life stages not just +there are multiple life stages within + + align:start position:0% +there are multiple life stages within + + + align:start position:0% +there are multiple life stages within +humans and multiple stages within um + + align:start position:0% +humans and multiple stages within um + + + align:start position:0% +humans and multiple stages within um +within the insect vector + + align:start position:0% +within the insect vector + + + align:start position:0% +within the insect vector +and now the genomics of these two just + + align:start position:0% +and now the genomics of these two just + + + align:start position:0% +and now the genomics of these two just +came out recently + + align:start position:0% +came out recently + + + align:start position:0% +came out recently +in + + align:start position:0% +in + + + align:start position:0% +in +the same week in nature and science this + + align:start position:0% +the same week in nature and science this + + + align:start position:0% +the same week in nature and science this +provides a whole new set of + + align:start position:0% +provides a whole new set of + + + align:start position:0% +provides a whole new set of +inspirations for work that can be done + + align:start position:0% +inspirations for work that can be done + + + align:start position:0% +inspirations for work that can be done +on these i think we should take a little + + align:start position:0% +on these i think we should take a little + + + align:start position:0% +on these i think we should take a little +break now + + align:start position:0% +break now + + + align:start position:0% +break now +and we'll wrap up the talk after that + + align:start position:0% +and we'll wrap up the talk after that + + + align:start position:0% +and we'll wrap up the talk after that +break \ No newline at end of file diff --git a/2B7e19xi4Sw.txt b/2B7e19xi4Sw.txt new file mode 100644 index 0000000000000000000000000000000000000000..f22a522298957ca2af77563bd5d36285213c4d35 --- /dev/null +++ b/2B7e19xi4Sw.txt @@ -0,0 +1,2027 @@ +align:start position:0% + +hi welcome back to recitation I've got a + + align:start position:0% +hi welcome back to recitation I've got a + + + align:start position:0% +hi welcome back to recitation I've got a +nice exercise here on Stokes theorem for + + align:start position:0% +nice exercise here on Stokes theorem for + + + align:start position:0% +nice exercise here on Stokes theorem for +you now this problem is a little bit + + align:start position:0% +you now this problem is a little bit + + + align:start position:0% +you now this problem is a little bit +more sophisticated than a lot of + + align:start position:0% +more sophisticated than a lot of + + + align:start position:0% +more sophisticated than a lot of +problems we've been doing in recitation + + align:start position:0% +problems we've been doing in recitation + + + align:start position:0% +problems we've been doing in recitation +so it requires a little bit more thought + + align:start position:0% +so it requires a little bit more thought + + + align:start position:0% +so it requires a little bit more thought +and it also involves more mathematical + + align:start position:0% +and it also involves more mathematical + + + align:start position:0% +and it also involves more mathematical +sophistication so so we're really we're + + align:start position:0% +sophistication so so we're really we're + + + align:start position:0% +sophistication so so we're really we're +we're doing a a sort of clever kind of + + align:start position:0% +we're doing a a sort of clever kind of + + + align:start position:0% +we're doing a a sort of clever kind of +proof here that that I like so hopefully + + align:start position:0% +proof here that that I like so hopefully + + + align:start position:0% +proof here that that I like so hopefully +hopefully you'll you like this one it's + + align:start position:0% +hopefully you'll you like this one it's + + + align:start position:0% +hopefully you'll you like this one it's +not it's a little bit in a different + + align:start position:0% +not it's a little bit in a different + + + align:start position:0% +not it's a little bit in a different +style than some of the ones we've done + + align:start position:0% +style than some of the ones we've done + + + align:start position:0% +style than some of the ones we've done +so so let me so I I think I need to talk + + align:start position:0% +so so let me so I I think I need to talk + + + align:start position:0% +so so let me so I I think I need to talk +about it a little bit before we get + + align:start position:0% +about it a little bit before we get + + + align:start position:0% +about it a little bit before we get +started so let's let F be the field XYZ + + align:start position:0% +started so let's let F be the field XYZ + + + align:start position:0% +started so let's let F be the field XYZ +so this is our our radial field that + + align:start position:0% +so this is our our radial field that + + + align:start position:0% +so this is our our radial field that +we've seen a lot in recitation so what + + align:start position:0% +we've seen a lot in recitation so what + + + align:start position:0% +we've seen a lot in recitation so what +I'd like you to do is prove that this + + align:start position:0% +I'd like you to do is prove that this + + + align:start position:0% +I'd like you to do is prove that this +field is not the curl of any field G all + + align:start position:0% +field is not the curl of any field G all + + + align:start position:0% +field is not the curl of any field G all +right so I'd like you to show that + + align:start position:0% +right so I'd like you to show that + + + align:start position:0% +right so I'd like you to show that +there's no field G such that f is equal + + align:start position:0% +there's no field G such that f is equal + + + align:start position:0% +there's no field G such that f is equal +to the curl of G now + + align:start position:0% +to the curl of G now + + + align:start position:0% +to the curl of G now +rather than just saying that to you and + + align:start position:0% +rather than just saying that to you and + + + align:start position:0% +rather than just saying that to you and +let you run off I have I have a + + align:start position:0% +let you run off I have I have a + + + align:start position:0% +let you run off I have I have a +suggestion for an interesting way you + + align:start position:0% +suggestion for an interesting way you + + + align:start position:0% +suggestion for an interesting way you +could go about this um and this this + + align:start position:0% +could go about this um and this this + + + align:start position:0% +could go about this um and this this +interesting way is going to use Stokes + + align:start position:0% +interesting way is going to use Stokes + + + align:start position:0% +interesting way is going to use Stokes +theorem so what I'd like you to do is is + + align:start position:0% +theorem so what I'd like you to do is is + + + align:start position:0% +theorem so what I'd like you to do is is +a proof by + + align:start position:0% +a proof by + + + align:start position:0% +a proof by +contradiction okay so what you're going + + align:start position:0% +contradiction okay so what you're going + + + align:start position:0% +contradiction okay so what you're going +to do is you're going to assume that f + + align:start position:0% +to do is you're going to assume that f + + + align:start position:0% +to do is you're going to assume that f +is a curl okay you're so you're going to + + align:start position:0% +is a curl okay you're so you're going to + + + align:start position:0% +is a curl okay you're so you're going to +assume that there is some G such that f + + align:start position:0% +assume that there is some G such that f + + + align:start position:0% +assume that there is some G such that f +is curl G and then you're going to use + + align:start position:0% +is curl G and then you're going to use + + + align:start position:0% +is curl G and then you're going to use +that to to to get a ridiculous + + align:start position:0% +that to to to get a ridiculous + + + align:start position:0% +that to to to get a ridiculous +conclusion so you're going to start with + + align:start position:0% +conclusion so you're going to start with + + + align:start position:0% +conclusion so you're going to start with +that premise and you're going to Res end + + align:start position:0% +that premise and you're going to Res end + + + align:start position:0% +that premise and you're going to Res end +up with a with a contradiction so this + + align:start position:0% +up with a with a contradiction so this + + + align:start position:0% +up with a with a contradiction so this +is the these two sort of arrows + + align:start position:0% +is the these two sort of arrows + + + align:start position:0% +is the these two sort of arrows +colliding into each other is a is a + + align:start position:0% +colliding into each other is a is a + + + align:start position:0% +colliding into each other is a is a +symbol that that mathematicians use for + + align:start position:0% +symbol that that mathematicians use for + + + align:start position:0% +symbol that that mathematicians use for +a contradiction so you're going to start + + align:start position:0% +a contradiction so you're going to start + + + align:start position:0% +a contradiction so you're going to start +from this premise and you're going to + + align:start position:0% +from this premise and you're going to + + + align:start position:0% +from this premise and you're going to +reach a contradiction and what that's + + align:start position:0% +reach a contradiction and what that's + + + align:start position:0% +reach a contradiction and what that's +going to show is that your premise + + align:start position:0% +going to show is that your premise + + + align:start position:0% +going to show is that your premise +couldn't be right yeah because if you if + + align:start position:0% +couldn't be right yeah because if you if + + + align:start position:0% +couldn't be right yeah because if you if +you start from a true premise well then + + align:start position:0% +you start from a true premise well then + + + align:start position:0% +you start from a true premise well then +all your conclusions should be true as + + align:start position:0% +all your conclusions should be true as + + + align:start position:0% +all your conclusions should be true as +well so so if you reach a false + + align:start position:0% +well so so if you reach a false + + + align:start position:0% +well so so if you reach a false +conclusion then then you must have had a + + align:start position:0% +conclusion then then you must have had a + + + align:start position:0% +conclusion then then you must have had a +false + + align:start position:0% +false + + + align:start position:0% +false +premise so what what what you're going + + align:start position:0% +premise so what what what you're going + + + align:start position:0% +premise so what what what you're going +to do is you're going to take a sphere + + align:start position:0% +to do is you're going to take a sphere + + + align:start position:0% +to do is you're going to take a sphere +of radius B centered at the origin and a + + align:start position:0% +of radius B centered at the origin and a + + + align:start position:0% +of radius B centered at the origin and a +curve C on the sphere you know a simple + + align:start position:0% +curve C on the sphere you know a simple + + + align:start position:0% +curve C on the sphere you know a simple +closed curve um so assuming that f is + + align:start position:0% +closed curve um so assuming that f is + + + align:start position:0% +closed curve um so assuming that f is +this curl of G what I'd like you to do + + align:start position:0% +this curl of G what I'd like you to do + + + align:start position:0% +this curl of G what I'd like you to do +is use Stokes theorem to interpret the + + align:start position:0% +is use Stokes theorem to interpret the + + + align:start position:0% +is use Stokes theorem to interpret the +the line integral of G dodr over C in + + align:start position:0% +the line integral of G dodr over C in + + + align:start position:0% +the line integral of G dodr over C in +two different ways okay and and + + align:start position:0% +two different ways okay and and + + + align:start position:0% +two different ways okay and and +interpreting this line integral in two + + align:start position:0% +interpreting this line integral in two + + + align:start position:0% +interpreting this line integral in two +different ways you're going to reach a + + align:start position:0% +different ways you're going to reach a + + + align:start position:0% +different ways you're going to reach a +contradiction and that will show that F + + align:start position:0% +contradiction and that will show that F + + + align:start position:0% +contradiction and that will show that F +really isn't a curl so that's what I'd + + align:start position:0% +really isn't a curl so that's what I'd + + + align:start position:0% +really isn't a curl so that's what I'd +like you to do so why don't you pause + + align:start position:0% +like you to do so why don't you pause + + + align:start position:0% +like you to do so why don't you pause +the video go ahead see if you can work + + align:start position:0% +the video go ahead see if you can work + + + align:start position:0% +the video go ahead see if you can work +that out come back and we'll talk about + + align:start position:0% +that out come back and we'll talk about + + + align:start position:0% +that out come back and we'll talk about +it + + align:start position:0% + + + + align:start position:0% + +together I hope you enjoyed working on + + align:start position:0% +together I hope you enjoyed working on + + + align:start position:0% +together I hope you enjoyed working on +this problem let's let's get started on + + align:start position:0% +this problem let's let's get started on + + + align:start position:0% +this problem let's let's get started on +it so + + align:start position:0% +it so + + + align:start position:0% +it so +the the as I was saying before we + + align:start position:0% +the the as I was saying before we + + + align:start position:0% +the the as I was saying before we +started what we're going to do is we're + + align:start position:0% +started what we're going to do is we're + + + align:start position:0% +started what we're going to do is we're +we're looking for a proof by + + align:start position:0% +we're looking for a proof by + + + align:start position:0% +we're looking for a proof by +contradiction so as the problem says + + align:start position:0% +contradiction so as the problem says + + + align:start position:0% +contradiction so as the problem says +we're going to start with a + + align:start position:0% + + + + align:start position:0% + +sphere and I'm going to take this curve + + align:start position:0% +sphere and I'm going to take this curve + + + align:start position:0% +sphere and I'm going to take this curve +C and it's a some Simply Connected + + align:start position:0% +C and it's a some Simply Connected + + + align:start position:0% +C and it's a some Simply Connected +closed curve there it's going to go + + align:start position:0% +closed curve there it's going to go + + + align:start position:0% +closed curve there it's going to go +around the back of the sphere and it's + + align:start position:0% +around the back of the sphere and it's + + + align:start position:0% +around the back of the sphere and it's +going to be oriented one way or the + + align:start position:0% +going to be oriented one way or the + + + align:start position:0% +going to be oriented one way or the +other and it's going to divide the + + align:start position:0% +other and it's going to divide the + + + align:start position:0% +other and it's going to divide the +sphere into two pieces so there's the + + align:start position:0% +sphere into two pieces so there's the + + + align:start position:0% +sphere into two pieces so there's the +the sort of one cap on one side of it S1 + + align:start position:0% +the sort of one cap on one side of it S1 + + + align:start position:0% +the sort of one cap on one side of it S1 +and then there's the whatever the other + + align:start position:0% +and then there's the whatever the other + + + align:start position:0% +and then there's the whatever the other +piece on the other side of it is + + align:start position:0% +piece on the other side of it is + + + align:start position:0% +piece on the other side of it is +S2 okay and so what we're going to do is + + align:start position:0% +S2 okay and so what we're going to do is + + + align:start position:0% +S2 okay and so what we're going to do is +we're going to talk about we're going to + + align:start position:0% +we're going to talk about we're going to + + + align:start position:0% +we're going to talk about we're going to +think about what what is this line + + align:start position:0% +think about what what is this line + + + align:start position:0% +think about what what is this line +integral okay so this this is our curve + + align:start position:0% +integral okay so this this is our curve + + + align:start position:0% +integral okay so this this is our curve +C here on the sphere so the integral + + align:start position:0% +C here on the sphere so the integral + + + align:start position:0% +C here on the sphere so the integral +over + + align:start position:0% +over + + + align:start position:0% +over +C of + + align:start position:0% +C of + + + align:start position:0% +C of +G + + align:start position:0% +G + + + align:start position:0% +G +dodr so this is what the problem + + align:start position:0% +dodr so this is what the problem + + + align:start position:0% +dodr so this is what the problem +suggests we think about so this is a + + align:start position:0% +suggests we think about so this is a + + + align:start position:0% +suggests we think about so this is a +line integral of a field. drr over the + + align:start position:0% +line integral of a field. drr over the + + + align:start position:0% +line integral of a field. drr over the +boundary of a surface well actually it's + + align:start position:0% +boundary of a surface well actually it's + + + align:start position:0% +boundary of a surface well actually it's +the boundary of two surfaces right it's + + align:start position:0% +the boundary of two surfaces right it's + + + align:start position:0% +the boundary of two surfaces right it's +it's C1 is the boundary of S1 sorry C is + + align:start position:0% +it's C1 is the boundary of S1 sorry C is + + + align:start position:0% +it's C1 is the boundary of S1 sorry C is +the boundary of S1 and C if we Orient it + + align:start position:0% +the boundary of S1 and C if we Orient it + + + align:start position:0% +the boundary of S1 and C if we Orient it +the other way is the boundary of S2 when + + align:start position:0% +the other way is the boundary of S2 when + + + align:start position:0% +the other way is the boundary of S2 when +we when we Orient them both + + align:start position:0% +we when we Orient them both + + + align:start position:0% +we when we Orient them both +outwards well um okay so so what is this + + align:start position:0% +outwards well um okay so so what is this + + + align:start position:0% +outwards well um okay so so what is this +um so this line integral so Stokes + + align:start position:0% +um so this line integral so Stokes + + + align:start position:0% +um so this line integral so Stokes +theorem tells us something about this + + align:start position:0% +theorem tells us something about this + + + align:start position:0% +theorem tells us something about this +line integral so let's let's first think + + align:start position:0% +line integral so let's let's first think + + + align:start position:0% +line integral so let's let's first think +about this as as the top cap that cap S1 + + align:start position:0% +about this as as the top cap that cap S1 + + + align:start position:0% +about this as as the top cap that cap S1 +with boundary C oriented so that they + + align:start position:0% +with boundary C oriented so that they + + + align:start position:0% +with boundary C oriented so that they +agree with each other so the normal is + + align:start position:0% +agree with each other so the normal is + + + align:start position:0% +agree with each other so the normal is +outwards on the sphere and C is + + align:start position:0% +outwards on the sphere and C is + + + align:start position:0% +outwards on the sphere and C is +proceeding in the direction that I've + + align:start position:0% +proceeding in the direction that I've + + + align:start position:0% +proceeding in the direction that I've +drawn the arrow here well in that + + align:start position:0% +drawn the arrow here well in that + + + align:start position:0% +drawn the arrow here well in that +circumstance we have that the that the + + align:start position:0% +circumstance we have that the that the + + + align:start position:0% +circumstance we have that the that the +integral around C of G dodr is equal to + + align:start position:0% +integral around C of G dodr is equal to + + + align:start position:0% +integral around C of G dodr is equal to +by Stokes theorem this is equal to the + + align:start position:0% +by Stokes theorem this is equal to the + + + align:start position:0% +by Stokes theorem this is equal to the +double integral or the surface integral + + align:start position:0% +double integral or the surface integral + + + align:start position:0% +double integral or the surface integral +over S1 + + align:start position:0% + + + + align:start position:0% + +of curl of G + + align:start position:0% +of curl of G + + + align:start position:0% +of curl of G +do + + align:start position:0% +do + + + align:start position:0% +do +n with respect to surface + + align:start position:0% +n with respect to surface + + + align:start position:0% +n with respect to surface +area right so this is just Stokes + + align:start position:0% +area right so this is just Stokes + + + align:start position:0% +area right so this is just Stokes +theorem Stokes theorem says the line + + align:start position:0% +theorem Stokes theorem says the line + + + align:start position:0% +theorem Stokes theorem says the line +integral of G around the boundary curve + + align:start position:0% +integral of G around the boundary curve + + + align:start position:0% +integral of G around the boundary curve +is equal to the surface integral of of + + align:start position:0% +is equal to the surface integral of of + + + align:start position:0% +is equal to the surface integral of of +the curl of G over over the region + + align:start position:0% +the curl of G over over the region + + + align:start position:0% +the curl of G over over the region +provided all our orientations are + + align:start position:0% +provided all our orientations are + + + align:start position:0% +provided all our orientations are +correct okay well we know though what + + align:start position:0% +correct okay well we know though what + + + align:start position:0% +correct okay well we know though what +what curl of G is because by assumption + + align:start position:0% +what curl of G is because by assumption + + + align:start position:0% +what curl of G is because by assumption +f is equal to curl of G okay so this is + + align:start position:0% +f is equal to curl of G okay so this is + + + align:start position:0% +f is equal to curl of G okay so this is +equal + + align:start position:0% +equal + + + align:start position:0% +equal +to the surface integral over + + align:start position:0% +to the surface integral over + + + align:start position:0% +to the surface integral over +1 of f do n DS so this is here so in the + + align:start position:0% +1 of f do n DS so this is here so in the + + + align:start position:0% +1 of f do n DS so this is here so in the +first step we use Stokes theorem in the + + align:start position:0% +first step we use Stokes theorem in the + + + align:start position:0% +first step we use Stokes theorem in the +second step we use our assumption that + + align:start position:0% +second step we use our assumption that + + + align:start position:0% +second step we use our assumption that +that curl G is equal to + + align:start position:0% +that curl G is equal to + + + align:start position:0% +that curl G is equal to +F Well now what well okay but we know + + align:start position:0% +F Well now what well okay but we know + + + align:start position:0% +F Well now what well okay but we know +what f is Right f is this radial field + + align:start position:0% +what f is Right f is this radial field + + + align:start position:0% +what f is Right f is this radial field +XYZ so F and N are are pointing in the + + align:start position:0% +XYZ so F and N are are pointing in the + + + align:start position:0% +XYZ so F and N are are pointing in the +same direction they're they're parallel + + align:start position:0% +same direction they're they're parallel + + + align:start position:0% +same direction they're they're parallel +to each other N is a unit Vector so this + + align:start position:0% +to each other N is a unit Vector so this + + + align:start position:0% +to each other N is a unit Vector so this +is just the length of F this f.n is just + + align:start position:0% +is just the length of F this f.n is just + + + align:start position:0% +is just the length of F this f.n is just +the length of f and since we're on a + + align:start position:0% +the length of f and since we're on a + + + align:start position:0% +the length of f and since we're on a +sphere of radius B this is just B okay + + align:start position:0% +sphere of radius B this is just B okay + + + align:start position:0% +sphere of radius B this is just B okay +so the the integrand is just B so this + + align:start position:0% +so the the integrand is just B so this + + + align:start position:0% +so the the integrand is just B so this +is + + align:start position:0% +is + + + align:start position:0% +is +the integral over + + align:start position:0% +the integral over + + + align:start position:0% +the integral over +S1 of + + align:start position:0% +S1 of + + + align:start position:0% +S1 of +B DS which is B * the + + align:start position:0% + + + + align:start position:0% + +area of + + align:start position:0% +area of + + + align:start position:0% +area of +S1 okay one thing I'd like you to notice + + align:start position:0% +S1 okay one thing I'd like you to notice + + + align:start position:0% +S1 okay one thing I'd like you to notice +is that in particular this is a positive + + align:start position:0% +is that in particular this is a positive + + + align:start position:0% +is that in particular this is a positive +number B is positive and the area is + + align:start position:0% +number B is positive and the area is + + + align:start position:0% +number B is positive and the area is +positive okay so that's our our first + + align:start position:0% +positive okay so that's our our first + + + align:start position:0% +positive okay so that's our our first +interpretation so we took our we took + + align:start position:0% +interpretation so we took our we took + + + align:start position:0% +interpretation so we took our we took +our field G that we suppose exists and + + align:start position:0% +our field G that we suppose exists and + + + align:start position:0% +our field G that we suppose exists and +we integrate it around this curve C and + + align:start position:0% +we integrate it around this curve C and + + + align:start position:0% +we integrate it around this curve C and +we apply Stokes theorem and then the + + align:start position:0% +we apply Stokes theorem and then the + + + align:start position:0% +we apply Stokes theorem and then the +fact that we know what f is means that + + align:start position:0% +fact that we know what f is means that + + + align:start position:0% +fact that we know what f is means that +we know what F do n is and so that makes + + align:start position:0% +we know what F do n is and so that makes + + + align:start position:0% +we know what F do n is and so that makes +our our surface integral very easy to + + align:start position:0% +our our surface integral very easy to + + + align:start position:0% +our our surface integral very easy to +compute and it turns out to be B time + + align:start position:0% +compute and it turns out to be B time + + + align:start position:0% +compute and it turns out to be B time +the area of s which I just happened to + + align:start position:0% +the area of s which I just happened to + + + align:start position:0% +the area of s which I just happened to +notice is a positive number okay well + + align:start position:0% +notice is a positive number okay well + + + align:start position:0% +notice is a positive number okay well +now we can do the same trick on the + + align:start position:0% +now we can do the same trick on the + + + align:start position:0% +now we can do the same trick on the +other half of the sphere right so we + + align:start position:0% +other half of the sphere right so we + + + align:start position:0% +other half of the sphere right so we +just did the top cap here we did S1 so + + align:start position:0% +just did the top cap here we did S1 so + + + align:start position:0% +just did the top cap here we did S1 so +now we have the bottom cap or you know + + align:start position:0% +now we have the bottom cap or you know + + + align:start position:0% +now we have the bottom cap or you know +whatever the all the rest of the sphere + + align:start position:0% +whatever the all the rest of the sphere + + + align:start position:0% +whatever the all the rest of the sphere +S2 okay so we can also get that the + + align:start position:0% +S2 okay so we can also get that the + + + align:start position:0% +S2 okay so we can also get that the +integral over C of g. drr we can + + align:start position:0% +integral over C of g. drr we can + + + align:start position:0% +integral over C of g. drr we can +interpret it in terms of Stokes theorem + + align:start position:0% +interpret it in terms of Stokes theorem + + + align:start position:0% +interpret it in terms of Stokes theorem +but notice then that c we we want we + + align:start position:0% +but notice then that c we we want we + + + align:start position:0% +but notice then that c we we want we +still want to use the same normal we + + align:start position:0% +still want to use the same normal we + + + align:start position:0% +still want to use the same normal we +like outwards pointing normals so we so + + align:start position:0% +like outwards pointing normals so we so + + + align:start position:0% +like outwards pointing normals so we so +we're going to have to orient C the + + align:start position:0% +we're going to have to orient C the + + + align:start position:0% +we're going to have to orient C the +other way in order to make Stokes + + align:start position:0% +other way in order to make Stokes + + + align:start position:0% +other way in order to make Stokes +theorem make sense so let's let's walk + + align:start position:0% +theorem make sense so let's let's walk + + + align:start position:0% +theorem make sense so let's let's walk +over here where we have some empty board + + align:start position:0% +over here where we have some empty board + + + align:start position:0% +over here where we have some empty board +space so we want to orient C the other + + align:start position:0% +space so we want to orient C the other + + + align:start position:0% +space so we want to orient C the other +way so in other words we want to take + + align:start position:0% +way so in other words we want to take + + + align:start position:0% +way so in other words we want to take +the negative of this line integral so + + align:start position:0% +the negative of this line integral so + + + align:start position:0% +the negative of this line integral so +it's minus G do Dr and if we apply + + align:start position:0% +it's minus G do Dr and if we apply + + + align:start position:0% +it's minus G do Dr and if we apply +Stokes theorem to this line integral so + + align:start position:0% +Stokes theorem to this line integral so + + + align:start position:0% +Stokes theorem to this line integral so +this is the same line integral but with + + align:start position:0% +this is the same line integral but with + + + align:start position:0% +this is the same line integral but with +the opposite orientation on C so with + + align:start position:0% +the opposite orientation on C so with + + + align:start position:0% +the opposite orientation on C so with +the opposite sign um well by Stokes + + align:start position:0% +the opposite sign um well by Stokes + + + align:start position:0% +the opposite sign um well by Stokes +theorem this is equal to the integral + + align:start position:0% +theorem this is equal to the integral + + + align:start position:0% +theorem this is equal to the integral +over + + align:start position:0% +over + + + align:start position:0% +over +S2 of the + + align:start position:0% +S2 of the + + + align:start position:0% +S2 of the +curl of + + align:start position:0% +curl of + + + align:start position:0% +curl of +G do + + align:start position:0% +G do + + + align:start position:0% +G do +n DS and so the way I've set this up + + align:start position:0% +n DS and so the way I've set this up + + + align:start position:0% +n DS and so the way I've set this up +this is still my outward pointing normal + + align:start position:0% +this is still my outward pointing normal + + + align:start position:0% +this is still my outward pointing normal +okay but again we can use our assumption + + align:start position:0% +okay but again we can use our assumption + + + align:start position:0% +okay but again we can use our assumption +and and we can get Curl + + align:start position:0% +and and we can get Curl + + + align:start position:0% +and and we can get Curl +of G is equal to F because that because + + align:start position:0% +of G is equal to F because that because + + + align:start position:0% +of G is equal to F because that because +we're assuming that g has this property + + align:start position:0% +we're assuming that g has this property + + + align:start position:0% +we're assuming that g has this property +so this is equal to again now it's the + + align:start position:0% +so this is equal to again now it's the + + + align:start position:0% +so this is equal to again now it's the +integral over + + align:start position:0% +integral over + + + align:start position:0% +integral over +S2 of + + align:start position:0% +S2 of + + + align:start position:0% +S2 of +f do + + align:start position:0% +f do + + + align:start position:0% +f do +n with respect to surface area and again + + align:start position:0% +n with respect to surface area and again + + + align:start position:0% +n with respect to surface area and again +n is the outward pointing normal and F + + align:start position:0% +n is the outward pointing normal and F + + + align:start position:0% +n is the outward pointing normal and F +is parallel to it so these two um so + + align:start position:0% +is parallel to it so these two um so + + + align:start position:0% +is parallel to it so these two um so +this do product is just the length of of + + align:start position:0% +this do product is just the length of of + + + align:start position:0% +this do product is just the length of of +f the outward pointing unit normal so + + align:start position:0% +f the outward pointing unit normal so + + + align:start position:0% +f the outward pointing unit normal so +this is just the length of f which is B + + align:start position:0% +this is just the length of f which is B + + + align:start position:0% +this is just the length of f which is B +so this is equal to B * + + align:start position:0% +so this is equal to B * + + + align:start position:0% +so this is equal to B * +the area of S2 which is also + + align:start position:0% +the area of S2 which is also + + + align:start position:0% +the area of S2 which is also +positive so what if we just shown well + + align:start position:0% +positive so what if we just shown well + + + align:start position:0% +positive so what if we just shown well +we started from the assumption that that + + align:start position:0% +we started from the assumption that that + + + align:start position:0% +we started from the assumption that that +there exists a g such that f is the curl + + align:start position:0% +there exists a g such that f is the curl + + + align:start position:0% +there exists a g such that f is the curl +of G and starting from that assumption + + align:start position:0% +of G and starting from that assumption + + + align:start position:0% +of G and starting from that assumption +we showed let's look we showed that the + + align:start position:0% +we showed let's look we showed that the + + + align:start position:0% +we showed let's look we showed that the +line integral around C of g. + + align:start position:0% +line integral around C of g. + + + align:start position:0% +line integral around C of g. +drr is equal to some positive + + align:start position:0% +drr is equal to some positive + + + align:start position:0% +drr is equal to some positive +number and we also + + align:start position:0% +number and we also + + + align:start position:0% +number and we also +showed over here that the negative of + + align:start position:0% +showed over here that the negative of + + + align:start position:0% +showed over here that the negative of +the line integral of G around C is equal + + align:start position:0% +the line integral of G around C is equal + + + align:start position:0% +the line integral of G around C is equal +to some positive number well this is + + align:start position:0% +to some positive number well this is + + + align:start position:0% +to some positive number well this is +clearly absurd that can't be true so + + align:start position:0% +clearly absurd that can't be true so + + + align:start position:0% +clearly absurd that can't be true so +starting from our assumption that F was + + align:start position:0% +starting from our assumption that F was + + + align:start position:0% +starting from our assumption that F was +the curl of G that there is a g such + + align:start position:0% +the curl of G that there is a g such + + + align:start position:0% +the curl of G that there is a g such +that f is the curl of G we reached an + + align:start position:0% +that f is the curl of G we reached an + + + align:start position:0% +that f is the curl of G we reached an +absurd conclusion we reached a + + align:start position:0% +absurd conclusion we reached a + + + align:start position:0% +absurd conclusion we reached a +conclusion that the same number is both + + align:start position:0% +conclusion that the same number is both + + + align:start position:0% +conclusion that the same number is both +positive and negative all right but that + + align:start position:0% +positive and negative all right but that + + + align:start position:0% +positive and negative all right but that +can't happen so that means our premise + + align:start position:0% +can't happen so that means our premise + + + align:start position:0% +can't happen so that means our premise +had to be false okay so this is a + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +contradiction so our assumption is false + + align:start position:0% +contradiction so our assumption is false + + + align:start position:0% +contradiction so our assumption is false +and our assumption was that we used to + + align:start position:0% +and our assumption was that we used to + + + align:start position:0% +and our assumption was that we used to +get this whole thing started that F was + + align:start position:0% +get this whole thing started that F was + + + align:start position:0% +get this whole thing started that F was +the curl of some + + align:start position:0% +the curl of some + + + align:start position:0% +the curl of some +G all right so what have we shown so we + + align:start position:0% +G all right so what have we shown so we + + + align:start position:0% +G all right so what have we shown so we +used a nice argument here with Stokes + + align:start position:0% +used a nice argument here with Stokes + + + align:start position:0% +used a nice argument here with Stokes +theorem in order to show that certain + + align:start position:0% +theorem in order to show that certain + + + align:start position:0% +theorem in order to show that certain +Fields aren't the curl of other fields + + align:start position:0% +Fields aren't the curl of other fields + + + align:start position:0% +Fields aren't the curl of other fields +so Stokes theorem limits the kind of + + align:start position:0% +so Stokes theorem limits the kind of + + + align:start position:0% +so Stokes theorem limits the kind of +fields that can be curls of other fields + + align:start position:0% +fields that can be curls of other fields + + + align:start position:0% +fields that can be curls of other fields +now perhaps you may have thought of + + align:start position:0% +now perhaps you may have thought of + + + align:start position:0% +now perhaps you may have thought of +other theorems that you can use that + + align:start position:0% +other theorems that you can use that + + + align:start position:0% +other theorems that you can use that +also limit what sorts of fields can be + + align:start position:0% +also limit what sorts of fields can be + + + align:start position:0% +also limit what sorts of fields can be +curls and there so there are other ways + + align:start position:0% +curls and there so there are other ways + + + align:start position:0% +curls and there so there are other ways +to reach this true conclusion that our + + align:start position:0% +to reach this true conclusion that our + + + align:start position:0% +to reach this true conclusion that our +field F whose components are X Y and Z + + align:start position:0% +field F whose components are X Y and Z + + + align:start position:0% +field F whose components are X Y and Z +is not the curl of any field this isn't + + align:start position:0% +is not the curl of any field this isn't + + + align:start position:0% +is not the curl of any field this isn't +the only way to reach that conclusion + + align:start position:0% +the only way to reach that conclusion + + + align:start position:0% +the only way to reach that conclusion +but this is a nice way that shows that + + align:start position:0% +but this is a nice way that shows that + + + align:start position:0% +but this is a nice way that shows that +Stokes theorem puts some limitations on + + align:start position:0% +Stokes theorem puts some limitations on + + + align:start position:0% +Stokes theorem puts some limitations on +what Fields can behave like if they're + + align:start position:0% +what Fields can behave like if they're + + + align:start position:0% +what Fields can behave like if they're +going to be curls I'll stop there \ No newline at end of file diff --git a/2JxUXSG9rKo.txt b/2JxUXSG9rKo.txt new file mode 100644 index 0000000000000000000000000000000000000000..3be0ebdffc43c16cd286931856ab6aba3ce1d62a --- /dev/null +++ b/2JxUXSG9rKo.txt @@ -0,0 +1,191 @@ +Now that we have some sense about how MOSFETs +function, let's use them to build circuits + +to process our digitally encoded information. + +We have two simple rules we'll use when building +the circuits, which, if they're followed, + +will allow us to abstract the behavior of +the MOSFET as a simple voltage-controlled + +switch. + +The first rule is that we'll only use n-channel +MOSFETs, which we'll call NFETs for short, + +when building pulldown circuits that connect +a signaling node to the GROUND rail of the + +power supply. + +When the pulldown circuit is conducting, the +signaling node will be at 0V and qualify as + +the digital value "0". + +If we obey this rule, NFETs will act switches +controlled by V_GS, the difference between + +the voltage of the gate terminal and the voltage +of the source terminal. + +When V_GS is lower than the MOSFET's threshold +voltage, the switch is "open" or not conducting + +and there is no connection between the MOSFET's +source and drain terminals. + +If V_GS is greater than the threshold voltage, +the switch is "on" or conducting and there + +is a connection between the source and drain +terminals. + +That path has a resistance determined by the +magnitude of V_GS. + +The larger V_GS, the lower the effective resistance +of the switch and the more current that will + +flow from drain to source. + +When designing pulldown circuits of NFET switches, +we can use the following simple mental model + +for each NFET switch: +if the gate voltage is a digital 0, the switch + +will be off; if the gate voltage is a digital +1, the switch will be on. + +The situation with PFET switches is analogous, +except that the potentials are reversed. + +Our rule is that PFETs can only be used in +pullup circuits, used to connect a signaling + +node to the power supply voltage, which we'll +call V_DD. + +When the pullup circuit is conducting, the +signaling node will be at V_DD volts and qualify + +as the digital value "1". + +PFETs have a negative threshold voltage and +V_GS has to be less than the threshold voltage + +in order for the PFET switch to be conducting. + +All these negatives can be a bit confusing, +but, happily there's a simple mental model + +we can use for each PFET switch in the pullup +circuit: + +if the gate voltage is a digital 0, the switch +will be on; if the gate voltage is a digital + +1, the switch will be off - basically the +opposite behavior of the NFET switch. + +You may be wondering why we can't use NFETs +in pullup circuits or PFETs in pulldown circuits. + +You'll get to explore the answer to this question +in the first lab of Assignment 2. + +Meanwhile, the short answer is that the signaling +node will experience degraded signaling levels + +and we'll loose the noise margins we've worked +so hard to create! + +Now consider the CMOS implementation of a +combinational inverter. + +If the inverter's input is a digital 0, its +output is a digital 1, and vice versa. + +The inverter circuit consists of a single +NFET switch for the pulldown circuit, connecting + +the output node to GROUND and a single PFET +switch for the pullup circuit, connecting + +the output to V_DD. + +The gate terminals of both switches are connected +to the inverter's input node. + +The inverter's voltage transfer characteristic +is shown in the figure. + +When V_IN is a digital 0 input, we see that +V_OUT is greater than or equal to V_OH, representing + +a digital 1 output. + +Let's look at the state of the pullup and +pulldown switches when the input is a digital + +0. + +Recalling the simple mental model for the +NFET and PFET switches, a 0-input means the + +NFET switch is off, so there's no connection +between the output node and ground, and the + +PFET switch is on, making a connection between +the output node and V_DD. + +Current will flow through the pullup switch, +charging the output node until its voltage + +reaches V_DD. + +Once both the source and drain terminals are +at V_DD, there's no voltage difference across + +the switch and hence no more current will +flow through the switch. + +Similarly, when V_IN is a digital 1, the NFET +switch is on and PFET switch is off, so the + +output is connected to ground and eventually +reaches a voltage of 0V. + +Again, current flow through pulldown switch +will cease once the output node reaches 0V. + +When the input voltage is in the middle of +its range, it's possible, depending on the + +particular power supply voltage used and the +threshold voltage of the MOSFETs, that both + +the pullup and pulldown circuits will be conducting +for a short period of time. + +That's okay. + +In fact, with both MOSFET switches on, small +changes in the input voltage will produce + +large changes in the output voltage, leading +to the very high gain exhibited by CMOS devices. + +This in turn will mean we can pick signaling +thresholds that incorporate generous noise + +margins, allowing CMOS devices to work reliably +in many different operating environments. + +This is our first CMOS combinational logic +gate. + +In the next video, we'll explore how to build +other, more interesting logic functions. \ No newline at end of file diff --git a/2q7gqUuG_EA.txt b/2q7gqUuG_EA.txt new file mode 100644 index 0000000000000000000000000000000000000000..b88d4f2a3bb3b00f819179c22f10780de1c28a83 --- /dev/null +++ b/2q7gqUuG_EA.txt @@ -0,0 +1,435 @@ +align:start position:0% + +co- teing with seren uh professors s of + + align:start position:0% +co- teing with seren uh professors s of + + + align:start position:0% +co- teing with seren uh professors s of +us David S um is really a lot of fun uh + + align:start position:0% +us David S um is really a lot of fun uh + + + align:start position:0% +us David S um is really a lot of fun uh +We've taught before we taught the 66 + + align:start position:0% +We've taught before we taught the 66 + + + align:start position:0% +We've taught before we taught the 66 +that's on ocw together um and serini is + + align:start position:0% +that's on ocw together um and serini is + + + align:start position:0% +that's on ocw together um and serini is +uh I would say one of the uh most + + align:start position:0% +uh I would say one of the uh most + + + align:start position:0% +uh I would say one of the uh most +humorous professors that I know at MIT + + align:start position:0% +humorous professors that I know at MIT + + + align:start position:0% +humorous professors that I know at MIT +so it's really a lot of fun to teach + + align:start position:0% +so it's really a lot of fun to teach + + + align:start position:0% +so it's really a lot of fun to teach +with him and uh I mean sometimes it's + + align:start position:0% +with him and uh I mean sometimes it's + + + align:start position:0% +with him and uh I mean sometimes it's +like a comedy R in his lectures and I + + align:start position:0% +like a comedy R in his lectures and I + + + align:start position:0% +like a comedy R in his lectures and I +like to do that too and lectures tell + + align:start position:0% +like to do that too and lectures tell + + + align:start position:0% +like to do that too and lectures tell +lots of jokes and and uh play together + + align:start position:0% +lots of jokes and and uh play together + + + align:start position:0% +lots of jokes and and uh play together +so it's really nice working together we + + align:start position:0% +so it's really nice working together we + + + align:start position:0% +so it's really nice working together we +have a good Dynamic for uh we're both + + align:start position:0% +have a good Dynamic for uh we're both + + + align:start position:0% +have a good Dynamic for uh we're both +super flexible like oh I need you to + + align:start position:0% +super flexible like oh I need you to + + + align:start position:0% +super flexible like oh I need you to +cover this lecture oh no problem I love + + align:start position:0% +cover this lecture oh no problem I love + + + align:start position:0% +cover this lecture oh no problem I love +that stuff in fact we were both kind of + + align:start position:0% +that stuff in fact we were both kind of + + + align:start position:0% +that stuff in fact we were both kind of +fighting over which lectures we wanted + + align:start position:0% +fighting over which lectures we wanted + + + align:start position:0% +fighting over which lectures we wanted +to teach because like I really want to + + align:start position:0% +to teach because like I really want to + + + align:start position:0% +to teach because like I really want to +teach this no no I taught it I really + + align:start position:0% +teach this no no I taught it I really + + + align:start position:0% +teach this no no I taught it I really +want to teach it this time and uh so + + align:start position:0% +want to teach it this time and uh so + + + align:start position:0% +want to teach it this time and uh so +that's a nice Dynamic to have it's not + + align:start position:0% +that's a nice Dynamic to have it's not + + + align:start position:0% +that's a nice Dynamic to have it's not +like oh you taught one too few lectures + + align:start position:0% +like oh you taught one too few lectures + + + align:start position:0% +like oh you taught one too few lectures +it's not balanced totally totally not + + align:start position:0% +it's not balanced totally totally not + + + align:start position:0% +it's not balanced totally totally not +like that um and both in 66 and 6046 in + + align:start position:0% +like that um and both in 66 and 6046 in + + + align:start position:0% +like that um and both in 66 and 6046 in +the last lecture we do a kind of actual + + align:start position:0% +the last lecture we do a kind of actual + + + align:start position:0% +the last lecture we do a kind of actual +comedy routine where we're somehow like + + align:start position:0% +comedy routine where we're somehow like + + + align:start position:0% +comedy routine where we're somehow like +fighting each other it's all all uh in + + align:start position:0% +fighting each other it's all all uh in + + + align:start position:0% +fighting each other it's all all uh in +good humor and it's pretty fun students + + align:start position:0% +good humor and it's pretty fun students + + + align:start position:0% +good humor and it's pretty fun students +really like it uh he's also uh in in + + align:start position:0% +really like it uh he's also uh in in + + + align:start position:0% +really like it uh he's also uh in in +both classes he has creative ideas and + + align:start position:0% +both classes he has creative ideas and + + + align:start position:0% +both classes he has creative ideas and +how to reward students for uh answering + + align:start position:0% +how to reward students for uh answering + + + align:start position:0% +how to reward students for uh answering +questions um so in 66 uh we were in a + + align:start position:0% +questions um so in 66 uh we were in a + + + align:start position:0% +questions um so in 66 uh we were in a +relatively uncomfortable lecture hall + + align:start position:0% +relatively uncomfortable lecture hall + + + align:start position:0% +relatively uncomfortable lecture hall +and so we had these uh pillows uh that + + align:start position:0% +and so we had these uh pillows uh that + + + align:start position:0% +and so we had these uh pillows uh that +we had custom printed and it had the + + align:start position:0% +we had custom printed and it had the + + + align:start position:0% +we had custom printed and it had the +name of the class and a little Rubik's + + align:start position:0% +name of the class and a little Rubik's + + + align:start position:0% +name of the class and a little Rubik's +Cube on it um and so if anyone ever + + align:start position:0% +Cube on it um and so if anyone ever + + + align:start position:0% +Cube on it um and so if anyone ever +answered a question in class or asked a + + align:start position:0% +answered a question in class or asked a + + + align:start position:0% +answered a question in class or asked a +good question then we would throw them a + + align:start position:0% +good question then we would throw them a + + + align:start position:0% +good question then we would throw them a +pillow kind of like a Frisbee and so for + + align:start position:0% +pillow kind of like a Frisbee and so for + + + align:start position:0% +pillow kind of like a Frisbee and so for +6046 Ser is like you know what we have + + align:start position:0% +6046 Ser is like you know what we have + + + align:start position:0% +6046 Ser is like you know what we have +to do this time is get actual Frisbees + + align:start position:0% +to do this time is get actual Frisbees + + + align:start position:0% +to do this time is get actual Frisbees +and so we got these blue and purple + + align:start position:0% +and so we got these blue and purple + + + align:start position:0% +and so we got these blue and purple +frisbees also custom printed with the + + align:start position:0% +frisbees also custom printed with the + + + align:start position:0% +frisbees also custom printed with the +class number and and a little diagram + + align:start position:0% +class number and and a little diagram + + + align:start position:0% +class number and and a little diagram +that is in lecture 20 or something + + align:start position:0% +that is in lecture 20 or something + + + align:start position:0% +that is in lecture 20 or something +um and so whenever anyone asked or + + align:start position:0% +um and so whenever anyone asked or + + + align:start position:0% +um and so whenever anyone asked or +answered a question we would throw them + + align:start position:0% +answered a question we would throw them + + + align:start position:0% +answered a question we would throw them +a Frisbee and we make jokes about + + align:start position:0% +a Frisbee and we make jokes about + + + align:start position:0% +a Frisbee and we make jokes about +whether blue was better or purple was + + align:start position:0% +whether blue was better or purple was + + + align:start position:0% +whether blue was better or purple was +better there was no better it was just + + align:start position:0% +better there was no better it was just + + + align:start position:0% +better there was no better it was just +uh so this is this is tough for me + + align:start position:0% +uh so this is this is tough for me + + + align:start position:0% +uh so this is this is tough for me +because I had to really learn how to + + align:start position:0% +because I had to really learn how to + + + align:start position:0% +because I had to really learn how to +throw frisbees but I think by the end of + + align:start position:0% +throw frisbees but I think by the end of + + + align:start position:0% +throw frisbees but I think by the end of +the semester I got pretty good \ No newline at end of file diff --git a/2x3F08_8B80.txt b/2x3F08_8B80.txt new file mode 100644 index 0000000000000000000000000000000000000000..4eaef392f1f0f6feddc1f5466af7607d36b25fb3 --- /dev/null +++ b/2x3F08_8B80.txt @@ -0,0 +1,6651 @@ +align:start position:0% + +all right um so what we're going to do + + align:start position:0% +all right um so what we're going to do + + + align:start position:0% +all right um so what we're going to do +today is that I'm going to start talking + + align:start position:0% +today is that I'm going to start talking + + + align:start position:0% +today is that I'm going to start talking +about the development of atomic theory + + align:start position:0% +about the development of atomic theory + + + align:start position:0% +about the development of atomic theory +so in the next few minutes I'm going to + + align:start position:0% +so in the next few minutes I'm going to + + + align:start position:0% +so in the next few minutes I'm going to +whiz through the observations that led + + align:start position:0% +whiz through the observations that led + + + align:start position:0% +whiz through the observations that led +to the belief that + + align:start position:0% +to the belief that + + + align:start position:0% +to the belief that +Adams were the most basic constituent of + + align:start position:0% +Adams were the most basic constituent of + + + align:start position:0% +Adams were the most basic constituent of +manner and then what we're going to see + + align:start position:0% +manner and then what we're going to see + + + align:start position:0% +manner and then what we're going to see +is that the atom can actually be split + + align:start position:0% +is that the atom can actually be split + + + align:start position:0% +is that the atom can actually be split +up that the atom is not the most basic + + align:start position:0% +up that the atom is not the most basic + + + align:start position:0% +up that the atom is not the most basic +constituent of matter that there's an at + + align:start position:0% +constituent of matter that there's an at + + + align:start position:0% +constituent of matter that there's an at +least an electron in a nucleus and we're + + align:start position:0% +least an electron in a nucleus and we're + + + align:start position:0% +least an electron in a nucleus and we're +going to start talking about what are + + align:start position:0% +going to start talking about what are + + + align:start position:0% +going to start talking about what are +the fundamental principles that um have + + align:start position:0% +the fundamental principles that um have + + + align:start position:0% +the fundamental principles that um have +to obtain in order for that electron and + + align:start position:0% +to obtain in order for that electron and + + + align:start position:0% +to obtain in order for that electron and +nucleus to hang together to remain an + + align:start position:0% +nucleus to hang together to remain an + + + align:start position:0% +nucleus to hang together to remain an +entity and what we're going to see is + + align:start position:0% +entity and what we're going to see is + + + align:start position:0% +entity and what we're going to see is +that we're going to have to + + align:start position:0% +that we're going to have to + + + align:start position:0% +that we're going to have to +to understand a new kind of mechanics to + + align:start position:0% +to understand a new kind of mechanics to + + + align:start position:0% +to understand a new kind of mechanics to +understand how that electron and nucleus + + align:start position:0% +understand how that electron and nucleus + + + align:start position:0% +understand how that electron and nucleus +hang + + align:start position:0% +hang + + + align:start position:0% +hang +together and then further on in the + + align:start position:0% +together and then further on in the + + + align:start position:0% +together and then further on in the +course we're going to see we're going to + + align:start position:0% +course we're going to see we're going to + + + align:start position:0% +course we're going to see we're going to +need that new kind of mechanics to also + + align:start position:0% +need that new kind of mechanics to also + + + align:start position:0% +need that new kind of mechanics to also +understand how two atoms hang together + + align:start position:0% +understand how two atoms hang together + + + align:start position:0% +understand how two atoms hang together +how two atoms bind uh to form a + + align:start position:0% +how two atoms bind uh to form a + + + align:start position:0% +how two atoms bind uh to form a +molecule all right but today I'll + + align:start position:0% +molecule all right but today I'll + + + align:start position:0% +molecule all right but today I'll +lecture for the first twoth thirds or + + align:start position:0% +lecture for the first twoth thirds or + + + align:start position:0% +lecture for the first twoth thirds or +three uh 3/4s of the course and then + + align:start position:0% +three uh 3/4s of the course and then + + + align:start position:0% +three uh 3/4s of the course and then +I'll stop and then I'll uh introduce the + + align:start position:0% +I'll stop and then I'll uh introduce the + + + align:start position:0% +I'll stop and then I'll uh introduce the +rest of our teaching team and we'll talk + + align:start position:0% +rest of our teaching team and we'll talk + + + align:start position:0% +rest of our teaching team and we'll talk +about the mechanics of the course we'll + + align:start position:0% +about the mechanics of the course we'll + + + align:start position:0% +about the mechanics of the course we'll +talk about the expectations of the + + align:start position:0% +talk about the expectations of the + + + align:start position:0% +talk about the expectations of the +course and uh some details like that + + align:start position:0% +course and uh some details like that + + + align:start position:0% +course and uh some details like that +okay okay so uh let's get going here and + + align:start position:0% +okay okay so uh let's get going here and + + + align:start position:0% +okay okay so uh let's get going here and +now we could turn the lights down + + align:start position:0% +now we could turn the lights down + + + align:start position:0% +now we could turn the lights down +because I am going to use the slide here + + align:start position:0% +because I am going to use the slide here + + + align:start position:0% +because I am going to use the slide here +in the + + align:start position:0% +in the + + + align:start position:0% +in the +front all right so the ancient Greek + + align:start position:0% +front all right so the ancient Greek + + + align:start position:0% +front all right so the ancient Greek +philosophers they certainly were known + + align:start position:0% +philosophers they certainly were known + + + align:start position:0% +philosophers they certainly were known +who have uh pondered whether matter can + + align:start position:0% +who have uh pondered whether matter can + + + align:start position:0% +who have uh pondered whether matter can +be divided endlessly into smaller and + + align:start position:0% +be divided endlessly into smaller and + + + align:start position:0% +be divided endlessly into smaller and +smaller pieces or whether there was a + + align:start position:0% +smaller pieces or whether there was a + + + align:start position:0% +smaller pieces or whether there was a +point at which you couldn't divide + + align:start position:0% +point at which you couldn't divide + + + align:start position:0% +point at which you couldn't divide +matter any + + align:start position:0% +matter any + + + align:start position:0% +matter any +further and Aristotle here well he was + + align:start position:0% +further and Aristotle here well he was + + + align:start position:0% +further and Aristotle here well he was +one of the philosophers who argued that + + align:start position:0% +one of the philosophers who argued that + + + align:start position:0% +one of the philosophers who argued that +matter could be divided into smaller and + + align:start position:0% +matter could be divided into smaller and + + + align:start position:0% +matter could be divided into smaller and +smaller particles chopped up into + + align:start position:0% +smaller particles chopped up into + + + align:start position:0% +smaller particles chopped up into +smaller and smaller pieces add infinitum + + align:start position:0% +smaller and smaller pieces add infinitum + + + align:start position:0% +smaller and smaller pieces add infinitum +matter was visible this is called the + + align:start position:0% +matter was visible this is called the + + + align:start position:0% +matter was visible this is called the +Continuum theory of matter Continuum + + align:start position:0% +Continuum theory of matter Continuum + + + align:start position:0% +Continuum theory of matter Continuum +because you don't have any discrete + + align:start position:0% +because you don't have any discrete + + + align:start position:0% +because you don't have any discrete +points it's a Continuum No Boundaries + + align:start position:0% +points it's a Continuum No Boundaries + + + align:start position:0% +points it's a Continuum No Boundaries +right but there was a contrary + + align:start position:0% +right but there was a contrary + + + align:start position:0% +right but there was a contrary +philosophy a contrary Philosophy + + align:start position:0% +philosophy a contrary Philosophy + + + align:start position:0% +philosophy a contrary Philosophy +heralded by democratus who actually was + + align:start position:0% +heralded by democratus who actually was + + + align:start position:0% +heralded by democratus who actually was +about a hundred years older than + + align:start position:0% +about a hundred years older than + + + align:start position:0% +about a hundred years older than +Aristotle and he held that matter indeed + + align:start position:0% +Aristotle and he held that matter indeed + + + align:start position:0% +Aristotle and he held that matter indeed +was composed of individual discreet part + + align:start position:0% +was composed of individual discreet part + + + align:start position:0% +was composed of individual discreet part +particles these discrete particles he + + align:start position:0% +particles these discrete particles he + + + align:start position:0% +particles these discrete particles he +called + + align:start position:0% +called + + + align:start position:0% +called +atomos a for not thos for divisible + + align:start position:0% +atomos a for not thos for divisible + + + align:start position:0% +atomos a for not thos for divisible +that's the origin of our word of course + + align:start position:0% +that's the origin of our word of course + + + align:start position:0% +that's the origin of our word of course +atams now in the fourth fifth century BC + + align:start position:0% +atams now in the fourth fifth century BC + + + align:start position:0% +atams now in the fourth fifth century BC +there wasn't uh much evidence one way or + + align:start position:0% +there wasn't uh much evidence one way or + + + align:start position:0% +there wasn't uh much evidence one way or +the other for these kinds of uh either + + align:start position:0% +the other for these kinds of uh either + + + align:start position:0% +the other for these kinds of uh either +one of these philosophies and I call it + + align:start position:0% +one of these philosophies and I call it + + + align:start position:0% +one of these philosophies and I call it +a philosophy because it was a search for + + align:start position:0% +a philosophy because it was a search for + + + align:start position:0% +a philosophy because it was a search for +understanding Reality by a speculative + + align:start position:0% +understanding Reality by a speculative + + + align:start position:0% +understanding Reality by a speculative +as opposed to a + + align:start position:0% +as opposed to a + + + align:start position:0% +as opposed to a +uh investigational or observational + + align:start position:0% +uh investigational or observational + + + align:start position:0% +uh investigational or observational +means but for whatever reason it was + + align:start position:0% +means but for whatever reason it was + + + align:start position:0% +means but for whatever reason it was +Aristotle here his Continuum theory of + + align:start position:0% +Aristotle here his Continuum theory of + + + align:start position:0% +Aristotle here his Continuum theory of +matter prevailed all the way to the 17th + + align:start position:0% +matter prevailed all the way to the 17th + + + align:start position:0% +matter prevailed all the way to the 17th +century and here in fact he is depicted + + align:start position:0% +century and here in fact he is depicted + + + align:start position:0% +century and here in fact he is depicted +by Raphael on a fresco in um on the + + align:start position:0% +by Raphael on a fresco in um on the + + + align:start position:0% +by Raphael on a fresco in um on the +walls of the Vatican holding Court the + + align:start position:0% +walls of the Vatican holding Court the + + + align:start position:0% +walls of the Vatican holding Court the +Continuum theory of + + align:start position:0% +Continuum theory of + + + align:start position:0% +Continuum theory of +matter but just about at the same time + + align:start position:0% +matter but just about at the same time + + + align:start position:0% +matter but just about at the same time +at which r + + align:start position:0% +at which r + + + align:start position:0% +at which r +painted this uh picture there were + + align:start position:0% +painted this uh picture there were + + + align:start position:0% +painted this uh picture there were +observations a set of observations that + + align:start position:0% +observations a set of observations that + + + align:start position:0% +observations a set of observations that +were being made that began to uh point + + align:start position:0% +were being made that began to uh point + + + align:start position:0% +were being made that began to uh point +out that matter wasn't really behaving + + align:start position:0% +out that matter wasn't really behaving + + + align:start position:0% +out that matter wasn't really behaving +and + + align:start position:0% +and + + + align:start position:0% +and +reacting like a Continuum that matter + + align:start position:0% +reacting like a Continuum that matter + + + align:start position:0% +reacting like a Continuum that matter +was uh behaving more like uh at some + + align:start position:0% +was uh behaving more like uh at some + + + align:start position:0% +was uh behaving more like uh at some +discreet nature uh to it so what were + + align:start position:0% +discreet nature uh to it so what were + + + align:start position:0% +discreet nature uh to it so what were +those observations well one of them was + + align:start position:0% +those observations well one of them was + + + align:start position:0% +those observations well one of them was +by this gentleman here Robert Boyle and + + align:start position:0% +by this gentleman here Robert Boyle and + + + align:start position:0% +by this gentleman here Robert Boyle and +uh guess what his formal occupation + + align:start position:0% + + + + align:start position:0% + +was chemistry yeah that's a good guess + + align:start position:0% +was chemistry yeah that's a good guess + + + align:start position:0% +was chemistry yeah that's a good guess +but his formal occupation was a + + align:start position:0% +but his formal occupation was a + + + align:start position:0% +but his formal occupation was a +theologian as most scientists were at at + + align:start position:0% +theologian as most scientists were at at + + + align:start position:0% +theologian as most scientists were at at +that time and you of course know him for + + align:start position:0% +that time and you of course know him for + + + align:start position:0% +that time and you of course know him for +um the empirical observation that the + + align:start position:0% +um the empirical observation that the + + + align:start position:0% +um the empirical observation that the +pressure times the volume is all + + align:start position:0% +pressure times the volume is all + + + align:start position:0% +pressure times the volume is all +constant as long as the temperature is + + align:start position:0% +constant as long as the temperature is + + + align:start position:0% +constant as long as the temperature is +constant but he actually Advanced the + + align:start position:0% +constant but he actually Advanced the + + + align:start position:0% +constant but he actually Advanced the +one of the first ideas of an element and + + align:start position:0% +one of the first ideas of an element and + + + align:start position:0% +one of the first ideas of an element and +that is he called an element a certain + + align:start position:0% +that is he called an element a certain + + + align:start position:0% +that is he called an element a certain +primitive unmingled + + align:start position:0% +primitive unmingled + + + align:start position:0% +primitive unmingled +body and that somehow you can take these + + align:start position:0% +body and that somehow you can take these + + + align:start position:0% +body and that somehow you can take these +primitive unmingled bodies and put them + + align:start position:0% +primitive unmingled bodies and put them + + + align:start position:0% +primitive unmingled bodies and put them +together to form a perfectly mixed body + + align:start position:0% +together to form a perfectly mixed body + + + align:start position:0% +together to form a perfectly mixed body +a compound a molecule so this was one of + + align:start position:0% +a compound a molecule so this was one of + + + align:start position:0% +a compound a molecule so this was one of +the first ideas of an element that comes + + align:start position:0% +the first ideas of an element that comes + + + align:start position:0% +the first ideas of an element that comes +together to form elements that come + + align:start position:0% +together to form elements that come + + + align:start position:0% +together to form elements that come +together to form + + align:start position:0% +together to form + + + align:start position:0% +together to form +molecules and then there was this + + align:start position:0% +molecules and then there was this + + + align:start position:0% +molecules and then there was this +gentleman Joseph priestle guess what his + + align:start position:0% +gentleman Joseph priestle guess what his + + + align:start position:0% +gentleman Joseph priestle guess what his +occupation + + align:start position:0% +occupation + + + align:start position:0% +occupation +was he was a priest of course and what + + align:start position:0% +was he was a priest of course and what + + + align:start position:0% +was he was a priest of course and what +did he do well he uh looked at reactions + + align:start position:0% +did he do well he uh looked at reactions + + + align:start position:0% +did he do well he uh looked at reactions +with def fisticated air def fisticated + + align:start position:0% +with def fisticated air def fisticated + + + align:start position:0% +with def fisticated air def fisticated +air reacting with materials and what he + + align:start position:0% +air reacting with materials and what he + + + align:start position:0% +air reacting with materials and what he +observed was that these materials + + align:start position:0% +observed was that these materials + + + align:start position:0% +observed was that these materials +reacted more vigorously in deep + + align:start position:0% +reacted more vigorously in deep + + + align:start position:0% +reacted more vigorously in deep +fisticated air well what's deep + + align:start position:0% +fisticated air well what's deep + + + align:start position:0% +fisticated air well what's deep +fisticated air well of course now we + + align:start position:0% +fisticated air well of course now we + + + align:start position:0% +fisticated air well of course now we +know de fisticated air is oxygen it's + + align:start position:0% +know de fisticated air is oxygen it's + + + align:start position:0% +know de fisticated air is oxygen it's +air with the nitrogen predominantly + + align:start position:0% +air with the nitrogen predominantly + + + align:start position:0% +air with the nitrogen predominantly +removed but it really took this + + align:start position:0% +removed but it really took this + + + align:start position:0% +removed but it really took this +gentleman + + align:start position:0% +gentleman + + + align:start position:0% +gentleman +laier it took this gentleman to really + + align:start position:0% +laier it took this gentleman to really + + + align:start position:0% +laier it took this gentleman to really +understand what Priestley was doing in + + align:start position:0% +understand what Priestley was doing in + + + align:start position:0% +understand what Priestley was doing in +his experiments and what leazier + + align:start position:0% +his experiments and what leazier + + + align:start position:0% +his experiments and what leazier +realized is that this deistic air was + + align:start position:0% +realized is that this deistic air was + + + align:start position:0% +realized is that this deistic air was +adding to the + + align:start position:0% +adding to the + + + align:start position:0% +adding to the +material when it did this + + align:start position:0% +material when it did this + + + align:start position:0% +material when it did this +reaction and he made those observations + + align:start position:0% +reaction and he made those observations + + + align:start position:0% +reaction and he made those observations +or he came to those conclusions by doing + + align:start position:0% +or he came to those conclusions by doing + + + align:start position:0% +or he came to those conclusions by doing +some very careful measurements of the + + align:start position:0% +some very careful measurements of the + + + align:start position:0% +some very careful measurements of the +mass before the reaction so the mass of + + align:start position:0% +mass before the reaction so the mass of + + + align:start position:0% +mass before the reaction so the mass of +the deistic air plus the mass of the + + align:start position:0% +the deistic air plus the mass of the + + + align:start position:0% +the deistic air plus the mass of the +material and he found that indeed the + + align:start position:0% +material and he found that indeed the + + + align:start position:0% +material and he found that indeed the +mass after the reaction was equivalent + + align:start position:0% +mass after the reaction was equivalent + + + align:start position:0% +mass after the reaction was equivalent +to that before the + + align:start position:0% +to that before the + + + align:start position:0% +to that before the +reaction and so he was one of the first + + align:start position:0% +reaction and so he was one of the first + + + align:start position:0% +reaction and so he was one of the first +IND indviduals to realize that a + + align:start position:0% +IND indviduals to realize that a + + + align:start position:0% +IND indviduals to realize that a +chemical reaction can be written down + + align:start position:0% +chemical reaction can be written down + + + align:start position:0% +chemical reaction can be written down +analogous to writing a algebraic + + align:start position:0% +analogous to writing a algebraic + + + align:start position:0% +analogous to writing a algebraic +equation well Lavoisier also did a lot + + align:start position:0% +equation well Lavoisier also did a lot + + + align:start position:0% +equation well Lavoisier also did a lot +of work with isolating uh elements he + + align:start position:0% +of work with isolating uh elements he + + + align:start position:0% +of work with isolating uh elements he +identified 17 metals and nine non-metals + + align:start position:0% +identified 17 metals and nine non-metals + + + align:start position:0% +identified 17 metals and nine non-metals +as + + align:start position:0% +as + + + align:start position:0% +as +elements well for all of his efforts we + + align:start position:0% +elements well for all of his efforts we + + + align:start position:0% +elements well for all of his efforts we +all know what happened to + + align:start position:0% +all know what happened to + + + align:start position:0% +all know what happened to +Lavoisier um because of his connection + + align:start position:0% +Lavoisier um because of his connection + + + align:start position:0% +Lavoisier um because of his connection +to the French monarchy you know the + + align:start position:0% +to the French monarchy you know the + + + align:start position:0% +to the French monarchy you know the +judge at his trial uh claimed that the + + align:start position:0% +judge at his trial uh claimed that the + + + align:start position:0% +judge at his trial uh claimed that the +Republic has no use for Sant lrange at + + align:start position:0% +Republic has no use for Sant lrange at + + + align:start position:0% +Republic has no use for Sant lrange at +that time a French mathematician said it + + align:start position:0% +that time a French mathematician said it + + + align:start position:0% +that time a French mathematician said it +took but a moment to uh cut through that + + align:start position:0% +took but a moment to uh cut through that + + + align:start position:0% +took but a moment to uh cut through that +head but it will require a hundred years + + align:start position:0% +head but it will require a hundred years + + + align:start position:0% +head but it will require a hundred years +to produce another like + + align:start position:0% +to produce another like + + + align:start position:0% +to produce another like +it well what there was another Frenchman + + align:start position:0% +it well what there was another Frenchman + + + align:start position:0% +it well what there was another Frenchman +at that time JL PR he was a little more + + align:start position:0% +at that time JL PR he was a little more + + + align:start position:0% +at that time JL PR he was a little more +politically savvy so he High tailed it + + align:start position:0% +politically savvy so he High tailed it + + + align:start position:0% +politically savvy so he High tailed it +over to Spain and led a long and + + align:start position:0% +over to Spain and led a long and + + + align:start position:0% +over to Spain and led a long and +healthful life as a professor in + + align:start position:0% +healthful life as a professor in + + + align:start position:0% +healthful life as a professor in +Madrid but what he did is he did some + + align:start position:0% +Madrid but what he did is he did some + + + align:start position:0% +Madrid but what he did is he did some +experiments and he observed that when + + align:start position:0% +experiments and he observed that when + + + align:start position:0% +experiments and he observed that when +two or more elements combined well they + + align:start position:0% +two or more elements combined well they + + + align:start position:0% +two or more elements combined well they +combine to form a compound they always + + align:start position:0% +combine to form a compound they always + + + align:start position:0% +combine to form a compound they always +combine in definite proportions by + + align:start position:0% +combine in definite proportions by + + + align:start position:0% +combine in definite proportions by +weight and it didn't matter what the + + align:start position:0% +weight and it didn't matter what the + + + align:start position:0% +weight and it didn't matter what the +method of preparation was and so because + + align:start position:0% +method of preparation was and so because + + + align:start position:0% +method of preparation was and so because +he made this observation over and over + + align:start position:0% +he made this observation over and over + + + align:start position:0% +he made this observation over and over +and over again with many different + + align:start position:0% +and over again with many different + + + align:start position:0% +and over again with many different +elements this became known as the law + + align:start position:0% +elements this became known as the law + + + align:start position:0% +elements this became known as the law +here of definite proportions again some + + align:start position:0% +here of definite proportions again some + + + align:start position:0% +here of definite proportions again some +indication that matter was had a discret + + align:start position:0% +indication that matter was had a discret + + + align:start position:0% +indication that matter was had a discret +nature to it right it wasn't just the + + align:start position:0% +nature to it right it wasn't just the + + + align:start position:0% +nature to it right it wasn't just the +Continuum some numbers were involved + + align:start position:0% +Continuum some numbers were involved + + + align:start position:0% +Continuum some numbers were involved +here all right but it really took this + + align:start position:0% +here all right but it really took this + + + align:start position:0% +here all right but it really took this +guy John Dalton English school teacher + + align:start position:0% +guy John Dalton English school teacher + + + align:start position:0% +guy John Dalton English school teacher +with a lot of + + align:start position:0% +with a lot of + + + align:start position:0% +with a lot of +interest he uh was aware of the + + align:start position:0% +interest he uh was aware of the + + + align:start position:0% +interest he uh was aware of the +observations of Bole and Priestley and + + align:start position:0% +observations of Bole and Priestley and + + + align:start position:0% +observations of Bole and Priestley and +Lavoisier and + + align:start position:0% +Lavoisier and + + + align:start position:0% +Lavoisier and +PR and what he realized is that he could + + align:start position:0% +PR and what he realized is that he could + + + align:start position:0% +PR and what he realized is that he could +begin to understand all of those + + align:start position:0% +begin to understand all of those + + + align:start position:0% +begin to understand all of those +observations if he went back all the way + + align:start position:0% +observations if he went back all the way + + + align:start position:0% +observations if he went back all the way +to + + align:start position:0% +to + + + align:start position:0% +to +democratus and democratus is idea of + + align:start position:0% +democratus and democratus is idea of + + + align:start position:0% +democratus and democratus is idea of +Atmos or atams these individual discreet + + align:start position:0% +Atmos or atams these individual discreet + + + align:start position:0% +Atmos or atams these individual discreet +particles of matter and so he set forth + + align:start position:0% +particles of matter and so he set forth + + + align:start position:0% +particles of matter and so he set forth +some postulates some postulates which of + + align:start position:0% +some postulates some postulates which of + + + align:start position:0% +some postulates some postulates which of +course now know are known as Dalton's + + align:start position:0% +course now know are known as Dalton's + + + align:start position:0% +course now know are known as Dalton's +atomic theory but what he said is that + + align:start position:0% +atomic theory but what he said is that + + + align:start position:0% +atomic theory but what he said is that +each element is composed of atoms he + + align:start position:0% +each element is composed of atoms he + + + align:start position:0% +each element is composed of atoms he +said that atoms of Any Given element are + + align:start position:0% +said that atoms of Any Given element are + + + align:start position:0% +said that atoms of Any Given element are +identical he said that compounds form + + align:start position:0% +identical he said that compounds form + + + align:start position:0% +identical he said that compounds form +when atoms of more than one element + + align:start position:0% +when atoms of more than one element + + + align:start position:0% +when atoms of more than one element +combined and he realized of course from + + align:start position:0% +combined and he realized of course from + + + align:start position:0% +combined and he realized of course from +Leer's OB observations that atoms are + + align:start position:0% +Leer's OB observations that atoms are + + + align:start position:0% +Leer's OB observations that atoms are +neither created nor are they + + align:start position:0% +neither created nor are they + + + align:start position:0% +neither created nor are they +destroyed now just in aside Dalton John + + align:start position:0% +destroyed now just in aside Dalton John + + + align:start position:0% +destroyed now just in aside Dalton John +Dalton with his breaths of breath of + + align:start position:0% +Dalton with his breaths of breath of + + + align:start position:0% +Dalton with his breaths of breath of +Interest he also was the first + + align:start position:0% +Interest he also was the first + + + align:start position:0% +Interest he also was the first +individual to document color blindness + + align:start position:0% +individual to document color blindness + + + align:start position:0% +individual to document color blindness +in human beings and in fact we do call + + align:start position:0% +in human beings and in fact we do call + + + align:start position:0% +in human beings and in fact we do call +color blindness + + align:start position:0% +color blindness + + + align:start position:0% +color blindness +daltonism so see we're getting you ready + + align:start position:0% +daltonism so see we're getting you ready + + + align:start position:0% +daltonism so see we're getting you ready +for medical school already all + + align:start position:0% +for medical school already all + + + align:start position:0% +for medical school already all +right okay but um what I want you to + + align:start position:0% +right okay but um what I want you to + + + align:start position:0% +right okay but um what I want you to +recognize here is that Mr Dalton didn't + + align:start position:0% +recognize here is that Mr Dalton didn't + + + align:start position:0% +recognize here is that Mr Dalton didn't +actually do any of the experiments + + align:start position:0% +actually do any of the experiments + + + align:start position:0% +actually do any of the experiments +himself although from what I know of him + + align:start position:0% +himself although from what I know of him + + + align:start position:0% +himself although from what I know of him +I think he could have done the + + align:start position:0% +I think he could have done the + + + align:start position:0% +I think he could have done the +experiments himself but rather he was + + align:start position:0% +experiments himself but rather he was + + + align:start position:0% +experiments himself but rather he was +aware of the seemingly disperate + + align:start position:0% +aware of the seemingly disperate + + + align:start position:0% +aware of the seemingly disperate +observations made by leier and Bo and PR + + align:start position:0% +observations made by leier and Bo and PR + + + align:start position:0% +observations made by leier and Bo and PR +and he just said well you + + align:start position:0% +and he just said well you + + + align:start position:0% +and he just said well you +know if I take those + + align:start position:0% +know if I take those + + + align:start position:0% +know if I take those +observations and I use this framework + + align:start position:0% +observations and I use this framework + + + align:start position:0% +observations and I use this framework +well then I can understand them they + + align:start position:0% +well then I can understand them they + + + align:start position:0% +well then I can understand them they +make sense within this + + align:start position:0% +make sense within this + + + align:start position:0% +make sense within this +framework and this is a powerful + + align:start position:0% +framework and this is a powerful + + + align:start position:0% +framework and this is a powerful +approach in science a lot of science + + align:start position:0% +approach in science a lot of science + + + align:start position:0% +approach in science a lot of science +progresses this way that is that there's + + align:start position:0% +progresses this way that is that there's + + + align:start position:0% +progresses this way that is that there's +this collection of seemingly disperate + + align:start position:0% +this collection of seemingly disperate + + + align:start position:0% +this collection of seemingly disperate +observations and then all of a sudden + + align:start position:0% +observations and then all of a sudden + + + align:start position:0% +observations and then all of a sudden +somebody comes along and sees an + + align:start position:0% +somebody comes along and sees an + + + align:start position:0% +somebody comes along and sees an +organizing principle in all of those + + align:start position:0% +organizing principle in all of those + + + align:start position:0% +organizing principle in all of those +observations and puts forth then these + + align:start position:0% +observations and puts forth then these + + + align:start position:0% +observations and puts forth then these +postulates that's what Dalton did here + + align:start position:0% +postulates that's what Dalton did here + + + align:start position:0% +postulates that's what Dalton did here +now of course course these postulates uh + + align:start position:0% +now of course course these postulates uh + + + align:start position:0% +now of course course these postulates uh +weren't accepted IM immediately and + + align:start position:0% +weren't accepted IM immediately and + + + align:start position:0% +weren't accepted IM immediately and +rightfully so because they were just + + align:start position:0% +rightfully so because they were just + + + align:start position:0% +rightfully so because they were just +postulates they needed further + + align:start position:0% +postulates they needed further + + + align:start position:0% +postulates they needed further +substantiation and that further + + align:start position:0% +substantiation and that further + + + align:start position:0% +substantiation and that further +substantiation came in terms of the work + + align:start position:0% +substantiation came in terms of the work + + + align:start position:0% +substantiation came in terms of the work +by this this gentleman Joseph gusak the + + align:start position:0% +by this this gentleman Joseph gusak the + + + align:start position:0% +by this this gentleman Joseph gusak the +law of combining + + align:start position:0% +law of combining + + + align:start position:0% +law of combining +volumes it came by the work of this + + align:start position:0% +volumes it came by the work of this + + + align:start position:0% +volumes it came by the work of this +gentleman this gentleman is Lorenzo + + align:start position:0% +gentleman this gentleman is Lorenzo + + + align:start position:0% +gentleman this gentleman is Lorenzo +Romano Amadeo Carl avagadro + + align:start position:0% +Romano Amadeo Carl avagadro + + + align:start position:0% +Romano Amadeo Carl avagadro +hypothesis and of course um you can all + + align:start position:0% +hypothesis and of course um you can all + + + align:start position:0% +hypothesis and of course um you can all +read Italian so you can read what's on + + align:start position:0% +read Italian so you can read what's on + + + align:start position:0% +read Italian so you can read what's on +the stamp here right it just says equal + + align:start position:0% +the stamp here right it just says equal + + + align:start position:0% +the stamp here right it just says equal +volumes of gas under the same uh + + align:start position:0% +volumes of gas under the same uh + + + align:start position:0% +volumes of gas under the same uh +conditions of temperature uh lead to the + + align:start position:0% +conditions of temperature uh lead to the + + + align:start position:0% +conditions of temperature uh lead to the +same number of molecules see you didn't + + align:start position:0% +same number of molecules see you didn't + + + align:start position:0% +same number of molecules see you didn't +know you could read Italian but there it + + align:start position:0% +know you could read Italian but there it + + + align:start position:0% +know you could read Italian but there it +is + + align:start position:0% +is + + + align:start position:0% +is +okay and further substantiation for this + + align:start position:0% +okay and further substantiation for this + + + align:start position:0% +okay and further substantiation for this +idea of an atom and the discreetness of + + align:start position:0% +idea of an atom and the discreetness of + + + align:start position:0% +idea of an atom and the discreetness of +matter came from this gentleman lewick + + align:start position:0% +matter came from this gentleman lewick + + + align:start position:0% +matter came from this gentleman lewick +boltzman gas kinetic theory who proposed + + align:start position:0% +boltzman gas kinetic theory who proposed + + + align:start position:0% +boltzman gas kinetic theory who proposed +that well you know pressure that must be + + align:start position:0% +that well you know pressure that must be + + + align:start position:0% +that well you know pressure that must be +due to these atoms that are moving + + align:start position:0% +due to these atoms that are moving + + + align:start position:0% +due to these atoms that are moving +around and hitting the walls of a vessel + + align:start position:0% +around and hitting the walls of a vessel + + + align:start position:0% +around and hitting the walls of a vessel +those impacts give rise to the pressure + + align:start position:0% +those impacts give rise to the pressure + + + align:start position:0% +those impacts give rise to the pressure +that is exerted on the walls of that + + align:start position:0% +that is exerted on the walls of that + + + align:start position:0% +that is exerted on the walls of that +vessel and then finally it took this + + align:start position:0% +vessel and then finally it took this + + + align:start position:0% +vessel and then finally it took this +gentleman canazaro and it took his + + align:start position:0% +gentleman canazaro and it took his + + + align:start position:0% +gentleman canazaro and it took his +statesmanship because what canazaro did + + align:start position:0% +statesmanship because what canazaro did + + + align:start position:0% +statesmanship because what canazaro did +and now this is the later 1800s or so + + align:start position:0% +and now this is the later 1800s or so + + + align:start position:0% +and now this is the later 1800s or so +what canazaro did is that he got the + + align:start position:0% +what canazaro did is that he got the + + + align:start position:0% +what canazaro did is that he got the +scientific establishment at that time + + align:start position:0% +scientific establishment at that time + + + align:start position:0% +scientific establishment at that time +and the scientific establishment at that + + align:start position:0% +and the scientific establishment at that + + + align:start position:0% +and the scientific establishment at that +time of course is this small group of + + align:start position:0% +time of course is this small group of + + + align:start position:0% +time of course is this small group of +pale males but he got them to listen to + + align:start position:0% +pale males but he got them to listen to + + + align:start position:0% +pale males but he got them to listen to +Dalton's atomic theory and then the + + align:start position:0% +Dalton's atomic theory and then the + + + align:start position:0% +Dalton's atomic theory and then the +ensuing experiments of avagadro + + align:start position:0% +ensuing experiments of avagadro + + + align:start position:0% +ensuing experiments of avagadro +and um and uh gayus saac etc etc and + + align:start position:0% +and um and uh gayus saac etc etc and + + + align:start position:0% +and um and uh gayus saac etc etc and +finally he he got them to say yes + + align:start position:0% +finally he he got them to say yes + + + align:start position:0% +finally he he got them to say yes +there's something right about uh this + + align:start position:0% +there's something right about uh this + + + align:start position:0% +there's something right about uh this +atomic theory of matter the idea that + + align:start position:0% +atomic theory of matter the idea that + + + align:start position:0% +atomic theory of matter the idea that +mass was made up of discrete particles + + align:start position:0% +mass was made up of discrete particles + + + align:start position:0% +mass was made up of discrete particles +called atomos or + + align:start position:0% +called atomos or + + + align:start position:0% +called atomos or +atoms well + + align:start position:0% +atoms well + + + align:start position:0% +atoms well +nowadays we of course can uh actually + + align:start position:0% +nowadays we of course can uh actually + + + align:start position:0% +nowadays we of course can uh actually +image individual atoms or + + align:start position:0% +image individual atoms or + + + align:start position:0% +image individual atoms or +molecules and uh what you see + + align:start position:0% +molecules and uh what you see + + + align:start position:0% +molecules and uh what you see +here is uh is a an array of 28 Co + + align:start position:0% +here is uh is a an array of 28 Co + + + align:start position:0% +here is uh is a an array of 28 Co +molecules and these 28 Co molecules are + + align:start position:0% +molecules and these 28 Co molecules are + + + align:start position:0% +molecules and these 28 Co molecules are +arranged in the form of a little + + align:start position:0% +arranged in the form of a little + + + align:start position:0% +arranged in the form of a little +man or a little + + align:start position:0% +man or a little + + + align:start position:0% +man or a little +woman um I'll let you figure it out but + + align:start position:0% +woman um I'll let you figure it out but + + + align:start position:0% +woman um I'll let you figure it out but +what these are molecule sitting on a + + align:start position:0% +what these are molecule sitting on a + + + align:start position:0% +what these are molecule sitting on a +platinum + + align:start position:0% +platinum + + + align:start position:0% +platinum +surface and so uh each one of these + + align:start position:0% +surface and so uh each one of these + + + align:start position:0% +surface and so uh each one of these +orange balls here is a CL molecule but + + align:start position:0% +orange balls here is a CL molecule but + + + align:start position:0% +orange balls here is a CL molecule but +when CL binds to a platinum surface it + + align:start position:0% +when CL binds to a platinum surface it + + + align:start position:0% +when CL binds to a platinum surface it +does so with the carbon end down and the + + align:start position:0% +does so with the carbon end down and the + + + align:start position:0% +does so with the carbon end down and the +oxygen end up and there's a really good + + align:start position:0% +oxygen end up and there's a really good + + + align:start position:0% +oxygen end up and there's a really good +reason for why that is the case and + + align:start position:0% +reason for why that is the case and + + + align:start position:0% +reason for why that is the case and +we'll talk about that when we talk about + + align:start position:0% +we'll talk about that when we talk about + + + align:start position:0% +we'll talk about that when we talk about +molecular orbitals so what you're seeing + + align:start position:0% +molecular orbitals so what you're seeing + + + align:start position:0% +molecular orbitals so what you're seeing +here is really just the the tops of the + + align:start position:0% +here is really just the the tops of the + + + align:start position:0% +here is really just the the tops of the +the co molecules you're seeing the + + align:start position:0% +the co molecules you're seeing the + + + align:start position:0% +the co molecules you're seeing the +oxygen ends of the co + + align:start position:0% +oxygen ends of the co + + + align:start position:0% +oxygen ends of the co +molecule all right well this image here + + align:start position:0% +molecule all right well this image here + + + align:start position:0% +molecule all right well this image here +was taken by something called a scanning + + align:start position:0% +was taken by something called a scanning + + + align:start position:0% +was taken by something called a scanning +tunneling + + align:start position:0% +tunneling + + + align:start position:0% +tunneling +microscope and um I'm sorry to say but + + align:start position:0% +microscope and um I'm sorry to say but + + + align:start position:0% +microscope and um I'm sorry to say but +this was actually invented just before + + align:start position:0% +this was actually invented just before + + + align:start position:0% +this was actually invented just before +you were + + align:start position:0% +you were + + + align:start position:0% +you were +born and uh it was invented was actually + + align:start position:0% +born and uh it was invented was actually + + + align:start position:0% +born and uh it was invented was actually +worked on by rusa and then perfected by + + align:start position:0% +worked on by rusa and then perfected by + + + align:start position:0% +worked on by rusa and then perfected by +benig and Roar and they earned a Nobel + + align:start position:0% +benig and Roar and they earned a Nobel + + + align:start position:0% +benig and Roar and they earned a Nobel +Prize for their work and um the way the + + align:start position:0% +Prize for their work and um the way the + + + align:start position:0% +Prize for their work and um the way the +technique works is uh the following let + + align:start position:0% +technique works is uh the following let + + + align:start position:0% +technique works is uh the following let +me uh maybe have the the board lights + + align:start position:0% +me uh maybe have the the board lights + + + align:start position:0% +me uh maybe have the the board lights +here so that we can uh I'm going to do + + align:start position:0% +here so that we can uh I'm going to do + + + align:start position:0% +here so that we can uh I'm going to do +some board + + align:start position:0% + + + + align:start position:0% + +work + + align:start position:0% +work + + + align:start position:0% +work +okay all right + + align:start position:0% +okay all right + + + align:start position:0% +okay all right +so what you do to to do this is that you + + align:start position:0% +so what you do to to do this is that you + + + align:start position:0% +so what you do to to do this is that you +take a Tungsten + + align:start position:0% +take a Tungsten + + + align:start position:0% +take a Tungsten +wire and you do a little chemistry you + + align:start position:0% +wire and you do a little chemistry you + + + align:start position:0% +wire and you do a little chemistry you +et the tungsten wire down to as fine a + + align:start position:0% +et the tungsten wire down to as fine a + + + align:start position:0% +et the tungsten wire down to as fine a +tip as you can so you um put it in some + + align:start position:0% +tip as you can so you um put it in some + + + align:start position:0% +tip as you can so you um put it in some +potassium hydroxide and some some + + align:start position:0% +potassium hydroxide and some some + + + align:start position:0% +potassium hydroxide and some some +current through it do a little cheem uh + + align:start position:0% +current through it do a little cheem uh + + + align:start position:0% +current through it do a little cheem uh +electrochemistry and what you'll get + + align:start position:0% +electrochemistry and what you'll get + + + align:start position:0% +electrochemistry and what you'll get +then is a a pretty fine tip at the end + + align:start position:0% +then is a a pretty fine tip at the end + + + align:start position:0% +then is a a pretty fine tip at the end +of this tungsten + + align:start position:0% +of this tungsten + + + align:start position:0% +of this tungsten +wire but then what you do is you take + + align:start position:0% +wire but then what you do is you take + + + align:start position:0% +wire but then what you do is you take +that tungsten wire and you attach it to + + align:start position:0% +that tungsten wire and you attach it to + + + align:start position:0% +that tungsten wire and you attach it to +a Paso Electric Crystal all right so a + + align:start position:0% +a Paso Electric Crystal all right so a + + + align:start position:0% +a Paso Electric Crystal all right so a +pazo electric Crystal and uh let me put + + align:start position:0% +pazo electric Crystal and uh let me put + + + align:start position:0% +pazo electric Crystal and uh let me put +it this way here a pzo + + align:start position:0% +it this way here a pzo + + + align:start position:0% +it this way here a pzo +electric material is some + + align:start position:0% +electric material is some + + + align:start position:0% +electric material is some +material that if you put a voltage + + align:start position:0% +material that if you put a voltage + + + align:start position:0% +material that if you put a voltage +across it it expands a little bit little + + align:start position:0% +across it it expands a little bit little + + + align:start position:0% +across it it expands a little bit little +bit meaning 10 20 angstroms okay and so + + align:start position:0% +bit meaning 10 20 angstroms okay and so + + + align:start position:0% +bit meaning 10 20 angstroms okay and so +um now if you attach the tungsten wire + + align:start position:0% +um now if you attach the tungsten wire + + + align:start position:0% +um now if you attach the tungsten wire +to that material you have some control + + align:start position:0% +to that material you have some control + + + align:start position:0% +to that material you have some control +on the angstrom scale right so that's + + align:start position:0% +on the angstrom scale right so that's + + + align:start position:0% +on the angstrom scale right so that's +what happens in order to move that tip + + align:start position:0% +what happens in order to move that tip + + + align:start position:0% +what happens in order to move that tip +around but then what you do is you take + + align:start position:0% +around but then what you do is you take + + + align:start position:0% +around but then what you do is you take +this tip and you bring it say within + + align:start position:0% +this tip and you bring it say within + + + align:start position:0% +this tip and you bring it say within +five angstroms of the top of this CL + + align:start position:0% +five angstroms of the top of this CL + + + align:start position:0% +five angstroms of the top of this CL +molecule so if I have my Platinum + + align:start position:0% +molecule so if I have my Platinum + + + align:start position:0% +molecule so if I have my Platinum +surface here and my carbon here and + + align:start position:0% +surface here and my carbon here and + + + align:start position:0% +surface here and my carbon here and +here's my oxygen all right what I'm + + align:start position:0% +here's my oxygen all right what I'm + + + align:start position:0% +here's my oxygen all right what I'm +going to do is I'm going to bring this + + align:start position:0% +going to do is I'm going to bring this + + + align:start position:0% +going to do is I'm going to bring this +this tip say within five angstroms here + + align:start position:0% +this tip say within five angstroms here + + + align:start position:0% +this tip say within five angstroms here +of this uh oxygen end of the co + + align:start position:0% +of this uh oxygen end of the co + + + align:start position:0% +of this uh oxygen end of the co +molecule okay and + + align:start position:0% +molecule okay and + + + align:start position:0% +molecule okay and +then I'm going to put a negative voltage + + align:start position:0% +then I'm going to put a negative voltage + + + align:start position:0% +then I'm going to put a negative voltage +on this tungsten tip here and I'm going + + align:start position:0% +on this tungsten tip here and I'm going + + + align:start position:0% +on this tungsten tip here and I'm going +to take the co molecule the I'm going to + + align:start position:0% +to take the co molecule the I'm going to + + + align:start position:0% +to take the co molecule the I'm going to +take the Platinum surface and I'm going + + align:start position:0% +take the Platinum surface and I'm going + + + align:start position:0% +take the Platinum surface and I'm going +to ground it now in this tungsten tip + + align:start position:0% +to ground it now in this tungsten tip + + + align:start position:0% +to ground it now in this tungsten tip +there are of course electrons and since + + align:start position:0% +there are of course electrons and since + + + align:start position:0% +there are of course electrons and since +this is a metal metal has a + + align:start position:0% +this is a metal metal has a + + + align:start position:0% +this is a metal metal has a +characteristic where some of those + + align:start position:0% +characteristic where some of those + + + align:start position:0% +characteristic where some of those +electrons aren't strongly bound to the + + align:start position:0% +electrons aren't strongly bound to the + + + align:start position:0% +electrons aren't strongly bound to the +nucleus they are actually um uh they + + align:start position:0% +nucleus they are actually um uh they + + + align:start position:0% +nucleus they are actually um uh they +actually roam around the solid + + align:start position:0% +actually roam around the solid + + + align:start position:0% +actually roam around the solid +okay and um this is a high energy State + + align:start position:0% +okay and um this is a high energy State + + + align:start position:0% +okay and um this is a high energy State +given that electrons are negatively + + align:start position:0% +given that electrons are negatively + + + align:start position:0% +given that electrons are negatively +charged and they're in an environment of + + align:start position:0% +charged and they're in an environment of + + + align:start position:0% +charged and they're in an environment of +this negative potential hey that's a + + align:start position:0% +this negative potential hey that's a + + + align:start position:0% +this negative potential hey that's a +rather high energy state for those + + align:start position:0% +rather high energy state for those + + + align:start position:0% +rather high energy state for those +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +so if I were to draw an energy level + + align:start position:0% +so if I were to draw an energy level + + + align:start position:0% +so if I were to draw an energy level +diagram here so this is energy and I'm + + align:start position:0% +diagram here so this is energy and I'm + + + align:start position:0% +diagram here so this is energy and I'm +going to represent those electrons on + + align:start position:0% +going to represent those electrons on + + + align:start position:0% +going to represent those electrons on +the tungsten tip it's going to be at a + + align:start position:0% +the tungsten tip it's going to be at a + + + align:start position:0% +the tungsten tip it's going to be at a +some high energy level so this is + + align:start position:0% +some high energy level so this is + + + align:start position:0% +some high energy level so this is +electrons on the tungsten right however + + align:start position:0% +electrons on the tungsten right however + + + align:start position:0% +electrons on the tungsten right however +there are also some electrons down here + + align:start position:0% +there are also some electrons down here + + + align:start position:0% +there are also some electrons down here +and they're at Ground potential so these + + align:start position:0% +and they're at Ground potential so these + + + align:start position:0% +and they're at Ground potential so these +electrons at are at a lower energy so + + align:start position:0% +electrons at are at a lower energy so + + + align:start position:0% +electrons at are at a lower energy so +I'm going to draw energy level + + align:start position:0% +I'm going to draw energy level + + + align:start position:0% +I'm going to draw energy level +representing them this is the electrons + + align:start position:0% +representing them this is the electrons + + + align:start position:0% +representing them this is the electrons +on the Platinum all right and so this + + align:start position:0% +on the Platinum all right and so this + + + align:start position:0% +on the Platinum all right and so this +coordinate here is kind of like a + + align:start position:0% +coordinate here is kind of like a + + + align:start position:0% +coordinate here is kind of like a +distance right this is the distance this + + align:start position:0% +distance right this is the distance this + + + align:start position:0% +distance right this is the distance this +is the electrons on the tungsten over + + align:start position:0% +is the electrons on the tungsten over + + + align:start position:0% +is the electrons on the tungsten over +here the electrons on the + + align:start position:0% +here the electrons on the + + + align:start position:0% +here the electrons on the +platinum and um what these electrons on + + align:start position:0% +platinum and um what these electrons on + + + align:start position:0% +platinum and um what these electrons on +the tungsten tip would like to do is to + + align:start position:0% +the tungsten tip would like to do is to + + + align:start position:0% +the tungsten tip would like to do is to +be here on the Platinum because that's a + + align:start position:0% +be here on the Platinum because that's a + + + align:start position:0% +be here on the Platinum because that's a +lower energy + + align:start position:0% +lower energy + + + align:start position:0% +lower energy +state but the problem is that there's a + + align:start position:0% +state but the problem is that there's a + + + align:start position:0% +state but the problem is that there's a +a gap right here there's no material + + align:start position:0% +a gap right here there's no material + + + align:start position:0% +a gap right here there's no material +between the tip and the oxygen end of + + align:start position:0% +between the tip and the oxygen end of + + + align:start position:0% +between the tip and the oxygen end of +this Co + + align:start position:0% +this Co + + + align:start position:0% +this Co +molecule there's if you do it in a + + align:start position:0% +molecule there's if you do it in a + + + align:start position:0% +molecule there's if you do it in a +vacuum there's a vacuum here there's a + + align:start position:0% +vacuum there's a vacuum here there's a + + + align:start position:0% +vacuum there's a vacuum here there's a +vacuum + + align:start position:0% +vacuum + + + align:start position:0% +vacuum +Gap and so for the electrons to go from + + align:start position:0% +Gap and so for the electrons to go from + + + align:start position:0% +Gap and so for the electrons to go from +here to here well there's a very large + + align:start position:0% +here to here well there's a very large + + + align:start position:0% +here to here well there's a very large +barrier this is a very high energy state + + align:start position:0% +barrier this is a very high energy state + + + align:start position:0% +barrier this is a very high energy state +if an electron were in between this Gap + + align:start position:0% +if an electron were in between this Gap + + + align:start position:0% +if an electron were in between this Gap +here so I'm going to represent that + + align:start position:0% +here so I'm going to represent that + + + align:start position:0% +here so I'm going to represent that +energy change as the electrons go from + + align:start position:0% +energy change as the electrons go from + + + align:start position:0% +energy change as the electrons go from +the tungsten tip to the Tung to the uh + + align:start position:0% +the tungsten tip to the Tung to the uh + + + align:start position:0% +the tungsten tip to the Tung to the uh +Platinum surface as is a barrier like + + align:start position:0% +Platinum surface as is a barrier like + + + align:start position:0% +Platinum surface as is a barrier like +this all right very large + + align:start position:0% +this all right very large + + + align:start position:0% +this all right very large +barrier now you've seen these kinds of + + align:start position:0% +barrier now you've seen these kinds of + + + align:start position:0% +barrier now you've seen these kinds of +uh we call them reaction coordinates in + + align:start position:0% +uh we call them reaction coordinates in + + + align:start position:0% +uh we call them reaction coordinates in +chemistry in in high school that as + + align:start position:0% +chemistry in in high school that as + + + align:start position:0% +chemistry in in high school that as +you've + + align:start position:0% +you've + + + align:start position:0% +you've +seen situations where we might have if + + align:start position:0% +seen situations where we might have if + + + align:start position:0% +seen situations where we might have if +we're doing an energy level diagram this + + align:start position:0% +we're doing an energy level diagram this + + + align:start position:0% +we're doing an energy level diagram this +is the energy of the reactant + + align:start position:0% +is the energy of the reactant + + + align:start position:0% +is the energy of the reactant +out here this is the energy of the + + align:start position:0% +out here this is the energy of the + + + align:start position:0% +out here this is the energy of the +products right and in between is this + + align:start position:0% +products right and in between is this + + + align:start position:0% +products right and in between is this +activation energy barrier that we call + + align:start position:0% +activation energy barrier that we call + + + align:start position:0% +activation energy barrier that we call +EAC in other words you have to put + + align:start position:0% +EAC in other words you have to put + + + align:start position:0% +EAC in other words you have to put +energy into the system in order to get + + align:start position:0% +energy into the system in order to get + + + align:start position:0% +energy into the system in order to get +their reaction to go you have to put + + align:start position:0% +their reaction to go you have to put + + + align:start position:0% +their reaction to go you have to put +energy into the system before you get + + align:start position:0% +energy into the system before you get + + + align:start position:0% +energy into the system before you get +any energy back out right and that's + + align:start position:0% +any energy back out right and that's + + + align:start position:0% +any energy back out right and that's +what happens in a chemical reaction we + + align:start position:0% +what happens in a chemical reaction we + + + align:start position:0% +what happens in a chemical reaction we +put energy into the system before we + + align:start position:0% +put energy into the system before we + + + align:start position:0% +put energy into the system before we +make it go or can make it + + align:start position:0% +make it go or can make it + + + align:start position:0% +make it go or can make it +go but in this particular case the + + align:start position:0% +go but in this particular case the + + + align:start position:0% +go but in this particular case the +electrons they don't behave like most + + align:start position:0% +electrons they don't behave like most + + + align:start position:0% +electrons they don't behave like most +reactants the electrons right here you + + align:start position:0% +reactants the electrons right here you + + + align:start position:0% +reactants the electrons right here you +know what they do these electrons hey + + align:start position:0% +know what they do these electrons hey + + + align:start position:0% +know what they do these electrons hey +they go right through that barrier they + + align:start position:0% +they go right through that barrier they + + + align:start position:0% +they go right through that barrier they +don't care that there's a brick wall + + align:start position:0% +don't care that there's a brick wall + + + align:start position:0% +don't care that there's a brick wall +there right they just go right through + + align:start position:0% +there right they just go right through + + + align:start position:0% +there right they just go right through +the barrier we call that + + align:start position:0% +the barrier we call that + + + align:start position:0% +the barrier we call that +tunneling and how in the world can that + + align:start position:0% +tunneling and how in the world can that + + + align:start position:0% +tunneling and how in the world can that +happen well that can happen because + + align:start position:0% +happen well that can happen because + + + align:start position:0% +happen well that can happen because +electrons unlike most atoms and + + align:start position:0% +electrons unlike most atoms and + + + align:start position:0% +electrons unlike most atoms and +molecules over here electrons are + + align:start position:0% +molecules over here electrons are + + + align:start position:0% +molecules over here electrons are +quantum mechanical particles and they do + + align:start position:0% +quantum mechanical particles and they do + + + align:start position:0% +quantum mechanical particles and they do +not obey classical mechanical rules and + + align:start position:0% +not obey classical mechanical rules and + + + align:start position:0% +not obey classical mechanical rules and +that's a subject that we're going to + + align:start position:0% +that's a subject that we're going to + + + align:start position:0% +that's a subject that we're going to +start talking about today and tomorrow + + align:start position:0% +start talking about today and tomorrow + + + align:start position:0% +start talking about today and tomorrow +and for the next few days so these + + align:start position:0% +and for the next few days so these + + + align:start position:0% +and for the next few days so these +electrons they just Tunnel right through + + align:start position:0% +electrons they just Tunnel right through + + + align:start position:0% +electrons they just Tunnel right through +that barrier and get over here to the + + align:start position:0% +that barrier and get over here to the + + + align:start position:0% +that barrier and get over here to the +other side all right so that means in + + align:start position:0% +other side all right so that means in + + + align:start position:0% +other side all right so that means in +this experimental setup if I were to + + align:start position:0% +this experimental setup if I were to + + + align:start position:0% +this experimental setup if I were to +connect a wire from this tungsten tip + + align:start position:0% +connect a wire from this tungsten tip + + + align:start position:0% +connect a wire from this tungsten tip +here to the platinum and I put in an + + align:start position:0% +here to the platinum and I put in an + + + align:start position:0% +here to the platinum and I put in an +ameter right there so I measure the + + align:start position:0% +ameter right there so I measure the + + + align:start position:0% +ameter right there so I measure the +current hey I'd be seeing some current + + align:start position:0% +current hey I'd be seeing some current + + + align:start position:0% +current hey I'd be seeing some current +flowed some measure of this flow of + + align:start position:0% +flowed some measure of this flow of + + + align:start position:0% +flowed some measure of this flow of +electrons from the tip to the tungsten + + align:start position:0% +electrons from the tip to the tungsten + + + align:start position:0% +electrons from the tip to the tungsten +and so that's what's done in the + + align:start position:0% +and so that's what's done in the + + + align:start position:0% +and so that's what's done in the +technique all right but now how do you + + align:start position:0% +technique all right but now how do you + + + align:start position:0% +technique all right but now how do you +get this image that I showed you earlier + + align:start position:0% +get this image that I showed you earlier + + + align:start position:0% +get this image that I showed you earlier +all right from this kind of + + align:start position:0% +all right from this kind of + + + align:start position:0% +all right from this kind of +arrangement well what you do is you now + + align:start position:0% +arrangement well what you do is you now + + + align:start position:0% +arrangement well what you do is you now +take this tungsten tip and you mount it + + align:start position:0% +take this tungsten tip and you mount it + + + align:start position:0% +take this tungsten tip and you mount it +on a um pazo electric Crystal which I + + align:start position:0% +on a um pazo electric Crystal which I + + + align:start position:0% +on a um pazo electric Crystal which I +forgot to tell you sometimes pazo + + align:start position:0% +forgot to tell you sometimes pazo + + + align:start position:0% +forgot to tell you sometimes pazo +electric crystal quartz is a Paso + + align:start position:0% +electric crystal quartz is a Paso + + + align:start position:0% +electric crystal quartz is a Paso +Electric barium titanate is a Paso + + align:start position:0% +Electric barium titanate is a Paso + + + align:start position:0% +Electric barium titanate is a Paso +Electric but you mount it on a pazal + + align:start position:0% +Electric but you mount it on a pazal + + + align:start position:0% +Electric but you mount it on a pazal +electric Crystal that will allow you to + + align:start position:0% +electric Crystal that will allow you to + + + align:start position:0% +electric Crystal that will allow you to +move from side to side all right so I + + align:start position:0% +move from side to side all right so I + + + align:start position:0% +move from side to side all right so I +move now my tungsten tip over a little + + align:start position:0% +move now my tungsten tip over a little + + + align:start position:0% +move now my tungsten tip over a little +bit all right and I know exactly how + + align:start position:0% +bit all right and I know exactly how + + + align:start position:0% +bit all right and I know exactly how +much over I moved it because I've + + align:start position:0% +much over I moved it because I've + + + align:start position:0% +much over I moved it because I've +calibrated my pazo electric Crystal but + + align:start position:0% +calibrated my pazo electric Crystal but + + + align:start position:0% +calibrated my pazo electric Crystal but +now what do you + + align:start position:0% +now what do you + + + align:start position:0% +now what do you +see well if you just moved it over you + + align:start position:0% +see well if you just moved it over you + + + align:start position:0% +see well if you just moved it over you +didn't change the vertical distance if + + align:start position:0% +didn't change the vertical distance if + + + align:start position:0% +didn't change the vertical distance if +you just moved it over what do you think + + align:start position:0% +you just moved it over what do you think + + + align:start position:0% +you just moved it over what do you think +would happen to the current + + align:start position:0% +would happen to the current + + + align:start position:0% +would happen to the current +here decrease would absolutely decrease + + align:start position:0% +here decrease would absolutely decrease + + + align:start position:0% +here decrease would absolutely decrease +why because you've now right changed the + + align:start position:0% +why because you've now right changed the + + + align:start position:0% +why because you've now right changed the +distance between the oxygen and and and + + align:start position:0% +distance between the oxygen and and and + + + align:start position:0% +distance between the oxygen and and and +that tungsten tip over here on this + + align:start position:0% +that tungsten tip over here on this + + + align:start position:0% +that tungsten tip over here on this +diagram you made this barrier + + align:start position:0% +diagram you made this barrier + + + align:start position:0% +diagram you made this barrier +thicker right and the thicker you make + + align:start position:0% +thicker right and the thicker you make + + + align:start position:0% +thicker right and the thicker you make +it the more difficult it is for those + + align:start position:0% +it the more difficult it is for those + + + align:start position:0% +it the more difficult it is for those +electrons to get through so the + + align:start position:0% +electrons to get through so the + + + align:start position:0% +electrons to get through so the +current's going to go down so in order + + align:start position:0% +current's going to go down so in order + + + align:start position:0% +current's going to go down so in order +to bring the current back up what you're + + align:start position:0% +to bring the current back up what you're + + + align:start position:0% +to bring the current back up what you're +going to do is you're going to take that + + align:start position:0% +going to do is you're going to take that + + + align:start position:0% +going to do is you're going to take that +tungsten tip and you're going to move it + + align:start position:0% +tungsten tip and you're going to move it + + + align:start position:0% +tungsten tip and you're going to move it +down + + align:start position:0% +down + + + align:start position:0% +down +slightly so that the distance now + + align:start position:0% +slightly so that the distance now + + + align:start position:0% +slightly so that the distance now +between the tip and the oxygen is going + + align:start position:0% +between the tip and the oxygen is going + + + align:start position:0% +between the tip and the oxygen is going +to be the same as it was in this + + align:start position:0% +to be the same as it was in this + + + align:start position:0% +to be the same as it was in this +particular position from here to here so + + align:start position:0% +particular position from here to here so + + + align:start position:0% +particular position from here to here so +then you bring the current back up but + + align:start position:0% +then you bring the current back up but + + + align:start position:0% +then you bring the current back up but +again you know exactly how far down you + + align:start position:0% +again you know exactly how far down you + + + align:start position:0% +again you know exactly how far down you +moveed that tip and how far over you + + align:start position:0% +moveed that tip and how far over you + + + align:start position:0% +moveed that tip and how far over you +move that tip + + align:start position:0% +move that tip + + + align:start position:0% +move that tip +right okay so you got now two + + align:start position:0% +right okay so you got now two + + + align:start position:0% +right okay so you got now two +points now we got to keep going so what + + align:start position:0% +points now we got to keep going so what + + + align:start position:0% +points now we got to keep going so what +are we going to do to scan well we're + + align:start position:0% +are we going to do to scan well we're + + + align:start position:0% +are we going to do to scan well we're +going to move this tungsten tip over + + align:start position:0% +going to move this tungsten tip over + + + align:start position:0% +going to move this tungsten tip over +again and again you know the current in + + align:start position:0% +again and again you know the current in + + + align:start position:0% +again and again you know the current in +this particular case is going to go down + + align:start position:0% +this particular case is going to go down + + + align:start position:0% +this particular case is going to go down +in order to bring it back up you're + + align:start position:0% +in order to bring it back up you're + + + align:start position:0% +in order to bring it back up you're +going to move this tip further down so + + align:start position:0% +going to move this tip further down so + + + align:start position:0% +going to move this tip further down so +that the distance between here and here + + align:start position:0% +that the distance between here and here + + + align:start position:0% +that the distance between here and here +is the same as it was originally so you + + align:start position:0% +is the same as it was originally so you + + + align:start position:0% +is the same as it was originally so you +reestablish the current but again then + + align:start position:0% +reestablish the current but again then + + + align:start position:0% +reestablish the current but again then +you know exactly how far down and how + + align:start position:0% +you know exactly how far down and how + + + align:start position:0% +you know exactly how far down and how +far over you move the + + align:start position:0% +far over you move the + + + align:start position:0% +far over you move the +tip and then what you do you assign a + + align:start position:0% +tip and then what you do you assign a + + + align:start position:0% +tip and then what you do you assign a +different color to the different + + align:start position:0% +different color to the different + + + align:start position:0% +different color to the different +distances above the co molecule and if + + align:start position:0% +distances above the co molecule and if + + + align:start position:0% +distances above the co molecule and if +you assign different colors you can get + + align:start position:0% +you assign different colors you can get + + + align:start position:0% +you assign different colors you can get +this image so for example if we can uh + + align:start position:0% +this image so for example if we can uh + + + align:start position:0% +this image so for example if we can uh +dim the lights on the Blackboard again + + align:start position:0% +dim the lights on the Blackboard again + + + align:start position:0% +dim the lights on the Blackboard again +and uh we'll look at the + + align:start position:0% + + + + align:start position:0% + +slide + + align:start position:0% +slide + + + align:start position:0% +slide +okay all right + + align:start position:0% +okay all right + + + align:start position:0% +okay all right +so if the tip is very far from the + + align:start position:0% +so if the tip is very far from the + + + align:start position:0% +so if the tip is very far from the +surface we give it kind of a whitish + + align:start position:0% +surface we give it kind of a whitish + + + align:start position:0% +surface we give it kind of a whitish +color and as it gets closer and closer + + align:start position:0% +color and as it gets closer and closer + + + align:start position:0% +color and as it gets closer and closer +to the surface we give it a darker and + + align:start position:0% +to the surface we give it a darker and + + + align:start position:0% +to the surface we give it a darker and +darker orangey color and then finally + + align:start position:0% +darker orangey color and then finally + + + align:start position:0% +darker orangey color and then finally +when it's so far down that it's actually + + align:start position:0% +when it's so far down that it's actually + + + align:start position:0% +when it's so far down that it's actually +in contact or tunneling to the Platinum + + align:start position:0% +in contact or tunneling to the Platinum + + + align:start position:0% +in contact or tunneling to the Platinum +we give it a blue color all right so + + align:start position:0% +we give it a blue color all right so + + + align:start position:0% +we give it a blue color all right so +that's how you get this image that's the + + align:start position:0% +that's how you get this image that's the + + + align:start position:0% +that's how you get this image that's the +basis of this uh + + align:start position:0% +basis of this uh + + + align:start position:0% +basis of this uh +technique + + align:start position:0% +technique + + + align:start position:0% +technique +okay so now you also notice that these + + align:start position:0% +okay so now you also notice that these + + + align:start position:0% +okay so now you also notice that these +Co molecules have a A peculiar + + align:start position:0% +Co molecules have a A peculiar + + + align:start position:0% +Co molecules have a A peculiar +Arrangement and uh this is not due to in + + align:start position:0% +Arrangement and uh this is not due to in + + + align:start position:0% +Arrangement and uh this is not due to in +the most urant language intelligent + + align:start position:0% +the most urant language intelligent + + + align:start position:0% +the most urant language intelligent +design rather this is due to a very + + align:start position:0% +design rather this is due to a very + + + align:start position:0% +design rather this is due to a very +patient experimentalist I.E graduate + + align:start position:0% +patient experimentalist I.E graduate + + + align:start position:0% +patient experimentalist I.E graduate +student + + align:start position:0% +student + + + align:start position:0% +student +who spent 24 hours putting these Co + + align:start position:0% +who spent 24 hours putting these Co + + + align:start position:0% +who spent 24 hours putting these Co +molecules into this particular position + + align:start position:0% +molecules into this particular position + + + align:start position:0% +molecules into this particular position +so how did he do that well he did it in + + align:start position:0% +so how did he do that well he did it in + + + align:start position:0% +so how did he do that well he did it in +the following way he first uh took a few + + align:start position:0% +the following way he first uh took a few + + + align:start position:0% +the following way he first uh took a few +Co molecules and put them anywhere on + + align:start position:0% +Co molecules and put them anywhere on + + + align:start position:0% +Co molecules and put them anywhere on +the surface just exposed the surface to + + align:start position:0% +the surface just exposed the surface to + + + align:start position:0% +the surface just exposed the surface to +some + + align:start position:0% +some + + + align:start position:0% +some +gas and then he imaged the surface to + + align:start position:0% +gas and then he imaged the surface to + + + align:start position:0% +gas and then he imaged the surface to +figure out where they were and so if the + + align:start position:0% +figure out where they were and so if the + + + align:start position:0% +figure out where they were and so if the +the co molecules or my balls my soccer + + align:start position:0% +the co molecules or my balls my soccer + + + align:start position:0% +the co molecules or my balls my soccer +balls are the co molecules and if my + + align:start position:0% +balls are the co molecules and if my + + + align:start position:0% +balls are the co molecules and if my +foot here is the tungston tip right he + + align:start position:0% +foot here is the tungston tip right he + + + align:start position:0% +foot here is the tungston tip right he +just imaged the surface right to figure + + align:start position:0% +just imaged the surface right to figure + + + align:start position:0% +just imaged the surface right to figure +out where they were so you knew where + + align:start position:0% +out where they were so you knew where + + + align:start position:0% +out where they were so you knew where +they were so then he's got to move these + + align:start position:0% +they were so then he's got to move these + + + align:start position:0% +they were so then he's got to move these +Co molecules so he brings the tip you + + align:start position:0% +Co molecules so he brings the tip you + + + align:start position:0% +Co molecules so he brings the tip you +know close to uh one of the co + + align:start position:0% +know close to uh one of the co + + + align:start position:0% +know close to uh one of the co +molecules and then if you put a voltage + + align:start position:0% +molecules and then if you put a voltage + + + align:start position:0% +molecules and then if you put a voltage +pulse on that Paso Electric and actually + + align:start position:0% +pulse on that Paso Electric and actually + + + align:start position:0% +pulse on that Paso Electric and actually +jerk the tip well you can jerk it such + + align:start position:0% +jerk the tip well you can jerk it such + + + align:start position:0% +jerk the tip well you can jerk it such +that you hit the co molecule and it goes + + align:start position:0% +that you hit the co molecule and it goes + + + align:start position:0% +that you hit the co molecule and it goes +flying away that's nice but now where + + align:start position:0% +flying away that's nice but now where + + + align:start position:0% +flying away that's nice but now where +did it go well in order to find out you + + align:start position:0% +did it go well in order to find out you + + + align:start position:0% +did it go well in order to find out you +got to do image the whole surface again + + align:start position:0% +got to do image the whole surface again + + + align:start position:0% +got to do image the whole surface again +right and you find that it is somewhere + + align:start position:0% +right and you find that it is somewhere + + + align:start position:0% +right and you find that it is somewhere +all the way over here all right now you + + align:start position:0% +all the way over here all right now you + + + align:start position:0% +all the way over here all right now you +really want it over there so you repeat + + align:start position:0% +really want it over there so you repeat + + + align:start position:0% +really want it over there so you repeat +the operation and uh well 24 hours later + + align:start position:0% +the operation and uh well 24 hours later + + + align:start position:0% +the operation and uh well 24 hours later +you get this little + + align:start position:0% +you get this little + + + align:start position:0% +you get this little +man and I know it was 24 hours later all + + align:start position:0% +man and I know it was 24 hours later all + + + align:start position:0% +man and I know it was 24 hours later all +right so um it's going to be a while + + align:start position:0% +right so um it's going to be a while + + + align:start position:0% +right so um it's going to be a while +before this kind of uh nanot technology + + align:start position:0% +before this kind of uh nanot technology + + + align:start position:0% +before this kind of uh nanot technology +assembling a molecule by molecule uh + + align:start position:0% +assembling a molecule by molecule uh + + + align:start position:0% +assembling a molecule by molecule uh +beats the synthesis in a beaker to put + + align:start position:0% +beats the synthesis in a beaker to put + + + align:start position:0% +beats the synthesis in a beaker to put +the molecules where you want them all + + align:start position:0% +the molecules where you want them all + + + align:start position:0% +the molecules where you want them all +right but + + align:start position:0% +right but + + + align:start position:0% +right but +um even though this uh kind of visual + + align:start position:0% +um even though this uh kind of visual + + + align:start position:0% +um even though this uh kind of visual +observation of atoms and molecules uh + + align:start position:0% +observation of atoms and molecules uh + + + align:start position:0% +observation of atoms and molecules uh +really wasn't possible + + align:start position:0% +really wasn't possible + + + align:start position:0% +really wasn't possible +100 years ago the evidence that I + + align:start position:0% +100 years ago the evidence that I + + + align:start position:0% +100 years ago the evidence that I +alluded to or quickly went through + + align:start position:0% +alluded to or quickly went through + + + align:start position:0% +alluded to or quickly went through +earlier was really quite uh compelling + + align:start position:0% +earlier was really quite uh compelling + + + align:start position:0% +earlier was really quite uh compelling +for the existence of atoms and the + + align:start position:0% +for the existence of atoms and the + + + align:start position:0% +for the existence of atoms and the +observation or the belief that the atom + + align:start position:0% +observation or the belief that the atom + + + align:start position:0% +observation or the belief that the atom +was the most basic constituent of matter + + align:start position:0% +was the most basic constituent of matter + + + align:start position:0% +was the most basic constituent of matter +the elementary particle you couldn't + + align:start position:0% +the elementary particle you couldn't + + + align:start position:0% +the elementary particle you couldn't +have anything smaller uh than an atam + + align:start position:0% +have anything smaller uh than an atam + + + align:start position:0% +have anything smaller uh than an atam +and in fact at the end of the last + + align:start position:0% +and in fact at the end of the last + + + align:start position:0% +and in fact at the end of the last +century it was generally believed that + + align:start position:0% +century it was generally believed that + + + align:start position:0% +century it was generally believed that +the theoretical structure of the + + align:start position:0% +the theoretical structure of the + + + align:start position:0% +the theoretical structure of the +universe was complete nature was + + align:start position:0% +universe was complete nature was + + + align:start position:0% +universe was complete nature was +understood there were no more + + align:start position:0% +understood there were no more + + + align:start position:0% +understood there were no more +discoveries to be made and after all you + + align:start position:0% +discoveries to be made and after all you + + + align:start position:0% +discoveries to be made and after all you +know there were by this time in the late + + align:start position:0% +know there were by this time in the late + + + align:start position:0% +know there were by this time in the late +1800s a lot of advances well Newtonian + + align:start position:0% +1800s a lot of advances well Newtonian + + + align:start position:0% +1800s a lot of advances well Newtonian +mechanics that had already been known + + align:start position:0% +mechanics that had already been known + + + align:start position:0% +mechanics that had already been known +for 250 years the mechanics that guides + + align:start position:0% +for 250 years the mechanics that guides + + + align:start position:0% +for 250 years the mechanics that guides +the motion of all bodies around us even + + align:start position:0% +the motion of all bodies around us even + + + align:start position:0% +the motion of all bodies around us even +astronomical bodies thermodynamics was + + align:start position:0% +astronomical bodies thermodynamics was + + + align:start position:0% +astronomical bodies thermodynamics was +completely developed statistical + + align:start position:0% +completely developed statistical + + + align:start position:0% +completely developed statistical +mechanics was developed statistical + + align:start position:0% +mechanics was developed statistical + + + align:start position:0% +mechanics was developed statistical +mechanics which relates the microscopic + + align:start position:0% +mechanics which relates the microscopic + + + align:start position:0% +mechanics which relates the microscopic +description of the behavior of matter to + + align:start position:0% +description of the behavior of matter to + + + align:start position:0% +description of the behavior of matter to +the macroscopic description of the + + align:start position:0% +the macroscopic description of the + + + align:start position:0% +the macroscopic description of the +behavior of matter and also there were + + align:start position:0% +behavior of matter and also there were + + + align:start position:0% +behavior of matter and also there were +these Optics experiments of young + + align:start position:0% +these Optics experiments of young + + + align:start position:0% +these Optics experiments of young +fresnell and Herz that seemed to put to + + align:start position:0% +fresnell and Herz that seemed to put to + + + align:start position:0% +fresnell and Herz that seemed to put to +rest the question of whether or not + + align:start position:0% +rest the question of whether or not + + + align:start position:0% +rest the question of whether or not +light was a particle or a wave boy those + + align:start position:0% +light was a particle or a wave boy those + + + align:start position:0% +light was a particle or a wave boy those +experiments seemed to be absolutely + + align:start position:0% +experiments seemed to be absolutely + + + align:start position:0% +experiments seemed to be absolutely +conclusive that light was a wave those + + align:start position:0% +conclusive that light was a wave those + + + align:start position:0% +conclusive that light was a wave those +experiments demonstrated Maxwell's + + align:start position:0% +experiments demonstrated Maxwell's + + + align:start position:0% +experiments demonstrated Maxwell's +equations Maxwell's equations that + + align:start position:0% +equations Maxwell's equations that + + + align:start position:0% +equations Maxwell's equations that +unified the field of uh Optics and uh + + align:start position:0% + + + + align:start position:0% + +electromagnetism so um you know by this + + align:start position:0% +electromagnetism so um you know by this + + + align:start position:0% +electromagnetism so um you know by this +time uh there was all of these + + align:start position:0% +time uh there was all of these + + + align:start position:0% +time uh there was all of these +accomplishments the idea was that uh + + align:start position:0% +accomplishments the idea was that uh + + + align:start position:0% +accomplishments the idea was that uh +everything was done and the idea was + + align:start position:0% +everything was done and the idea was + + + align:start position:0% +everything was done and the idea was +remaining that the work that remained + + align:start position:0% +remaining that the work that remained + + + align:start position:0% +remaining that the work that remained +was largely to investigate the next + + align:start position:0% +was largely to investigate the next + + + align:start position:0% +was largely to investigate the next +decimal place everything else was + + align:start position:0% +decimal place everything else was + + + align:start position:0% +decimal place everything else was +done however at the same time by the + + align:start position:0% +done however at the same time by the + + + align:start position:0% +done however at the same time by the +late + + align:start position:0% +late + + + align:start position:0% +late +1800s there began to be a two sets of + + align:start position:0% +1800s there began to be a two sets of + + + align:start position:0% +1800s there began to be a two sets of +observations two tracks of + + align:start position:0% +observations two tracks of + + + align:start position:0% +observations two tracks of +observations that if you look closely + + align:start position:0% +observations that if you look closely + + + align:start position:0% +observations that if you look closely +began to illustrate that maybe things + + align:start position:0% +began to illustrate that maybe things + + + align:start position:0% +began to illustrate that maybe things +weren't quite so uh clear maybe things + + align:start position:0% +weren't quite so uh clear maybe things + + + align:start position:0% +weren't quite so uh clear maybe things +weren't quite as well understood and + + align:start position:0% +weren't quite as well understood and + + + align:start position:0% +weren't quite as well understood and +what were those + + align:start position:0% +what were those + + + align:start position:0% +what were those +observations well one of those + + align:start position:0% +observations well one of those + + + align:start position:0% +observations well one of those +observations is the discovery that we're + + align:start position:0% +observations is the discovery that we're + + + align:start position:0% +observations is the discovery that we're +going to start looking at today that the + + align:start position:0% +going to start looking at today that the + + + align:start position:0% +going to start looking at today that the +atom is not the most basic constituent + + align:start position:0% +atom is not the most basic constituent + + + align:start position:0% +atom is not the most basic constituent +of matter that you can take an atom + + align:start position:0% +of matter that you can take an atom + + + align:start position:0% +of matter that you can take an atom +apart into an electron and a nucleus at + + align:start position:0% +apart into an electron and a nucleus at + + + align:start position:0% +apart into an electron and a nucleus at +least an electron and a nucleus so + + align:start position:0% +least an electron and a nucleus so + + + align:start position:0% +least an electron and a nucleus so +that's one track track the other track + + align:start position:0% +that's one track track the other track + + + align:start position:0% +that's one track track the other track +is + + align:start position:0% +is + + + align:start position:0% +is +that um + + align:start position:0% +that um + + + align:start position:0% +that um +light appeared to behave in some cases + + align:start position:0% +light appeared to behave in some cases + + + align:start position:0% +light appeared to behave in some cases +like a particle and not a wave and one + + align:start position:0% +like a particle and not a wave and one + + + align:start position:0% +like a particle and not a wave and one +of those cases is this observation here + + align:start position:0% +of those cases is this observation here + + + align:start position:0% +of those cases is this observation here +of the photoelectric effect so what + + align:start position:0% +of the photoelectric effect so what + + + align:start position:0% +of the photoelectric effect so what +we're going to do is we're going to look + + align:start position:0% +we're going to do is we're going to look + + + align:start position:0% +we're going to do is we're going to look +at both tracks of observations here and + + align:start position:0% +at both tracks of observations here and + + + align:start position:0% +at both tracks of observations here and +we're going to see how these + + align:start position:0% +we're going to see how these + + + align:start position:0% +we're going to see how these +observations made it such that it was + + align:start position:0% +observations made it such that it was + + + align:start position:0% +observations made it such that it was +impossible to explain how an atom held + + align:start position:0% +impossible to explain how an atom held + + + align:start position:0% +impossible to explain how an atom held +together how an electron and a nucleus + + align:start position:0% +together how an electron and a nucleus + + + align:start position:0% +together how an electron and a nucleus +held together within the classical way + + align:start position:0% +held together within the classical way + + + align:start position:0% +held together within the classical way +of thinking within the newtonium + + align:start position:0% +of thinking within the newtonium + + + align:start position:0% +of thinking within the newtonium +mechanics the mechanics that you're + + align:start position:0% +mechanics the mechanics that you're + + + align:start position:0% +mechanics the mechanics that you're +going to be looking at this semester in + + align:start position:0% +going to be looking at this semester in + + + align:start position:0% +going to be looking at this semester in +801 you can't use that mechanics to + + align:start position:0% +801 you can't use that mechanics to + + + align:start position:0% +801 you can't use that mechanics to +understand how this electron in the + + align:start position:0% +understand how this electron in the + + + align:start position:0% +understand how this electron in the +nucleus stay together you can't use that + + align:start position:0% +nucleus stay together you can't use that + + + align:start position:0% +nucleus stay together you can't use that +mechanics to understand how two atoms + + align:start position:0% +mechanics to understand how two atoms + + + align:start position:0% +mechanics to understand how two atoms +are bound together we need a new way of + + align:start position:0% +are bound together we need a new way of + + + align:start position:0% +are bound together we need a new way of +thinking and it's these two tracks of + + align:start position:0% +thinking and it's these two tracks of + + + align:start position:0% +thinking and it's these two tracks of +observations that led to the Discovery + + align:start position:0% +observations that led to the Discovery + + + align:start position:0% +observations that led to the Discovery +in a sense of this new kind of mechanics + + align:start position:0% +in a sense of this new kind of mechanics + + + align:start position:0% +in a sense of this new kind of mechanics +that we're going to be talking + + align:start position:0% +that we're going to be talking + + + align:start position:0% +that we're going to be talking +about okay so let's start on one of + + align:start position:0% +about okay so let's start on one of + + + align:start position:0% +about okay so let's start on one of +these tracks and that track is + + align:start position:0% +these tracks and that track is + + + align:start position:0% +these tracks and that track is +the a track of seeing that the atom is + + align:start position:0% +the a track of seeing that the atom is + + + align:start position:0% +the a track of seeing that the atom is +not the most basic constituent of + + align:start position:0% +not the most basic constituent of + + + align:start position:0% +not the most basic constituent of +matter and uh the first observation is + + align:start position:0% +matter and uh the first observation is + + + align:start position:0% +matter and uh the first observation is +done done by this gentleman JJ Thomas + + align:start position:0% +done done by this gentleman JJ Thomas + + + align:start position:0% +done done by this gentleman JJ Thomas +it's the discovery of the + + align:start position:0% +it's the discovery of the + + + align:start position:0% +it's the discovery of the +electron okay so uh I'm going to need + + align:start position:0% +electron okay so uh I'm going to need + + + align:start position:0% +electron okay so uh I'm going to need +the lights on + + align:start position:0% + + + + align:start position:0% + +again all right so what JJ Thomas was + + align:start position:0% +again all right so what JJ Thomas was + + + align:start position:0% +again all right so what JJ Thomas was +interested in doing was understanding + + align:start position:0% +interested in doing was understanding + + + align:start position:0% +interested in doing was understanding +what discharges were made up right so he + + align:start position:0% +what discharges were made up right so he + + + align:start position:0% +what discharges were made up right so he +had a a glass tube that was evacuated + + align:start position:0% +had a a glass tube that was evacuated + + + align:start position:0% +had a a glass tube that was evacuated +and in it he had what we're going to + + align:start position:0% +and in it he had what we're going to + + + align:start position:0% +and in it he had what we're going to +call here a + + align:start position:0% +call here a + + + align:start position:0% +call here a +cathode and he had an + + align:start position:0% +cathode and he had an + + + align:start position:0% +cathode and he had an +anode and uh as I said a glass tube he + + align:start position:0% +anode and uh as I said a glass tube he + + + align:start position:0% +anode and uh as I said a glass tube he +pumps out the air and then he fills it + + align:start position:0% +pumps out the air and then he fills it + + + align:start position:0% +pumps out the air and then he fills it +up with uh hydrogen + + align:start position:0% +up with uh hydrogen + + + align:start position:0% +up with uh hydrogen +H2 and what he does is he puts a large + + align:start position:0% +H2 and what he does is he puts a large + + + align:start position:0% +H2 and what he does is he puts a large +negative potential on this cathod and on + + align:start position:0% +negative potential on this cathod and on + + + align:start position:0% +negative potential on this cathod and on +the anode he puts a large positive + + align:start position:0% +the anode he puts a large positive + + + align:start position:0% +the anode he puts a large positive +potential and he cranks up the potential + + align:start position:0% +potential and he cranks up the potential + + + align:start position:0% +potential and he cranks up the potential +difference here and he keeps cranking it + + align:start position:0% +difference here and he keeps cranking it + + + align:start position:0% +difference here and he keeps cranking it +up until at some point the gas begins to + + align:start position:0% +up until at some point the gas begins to + + + align:start position:0% +up until at some point the gas begins to +glow and it's at that point that this + + align:start position:0% +glow and it's at that point that this + + + align:start position:0% +glow and it's at that point that this +discharge here is + + align:start position:0% +discharge here is + + + align:start position:0% +discharge here is +ignited and uh this kind of a plasma and + + align:start position:0% +ignited and uh this kind of a plasma and + + + align:start position:0% +ignited and uh this kind of a plasma and +he wanted to understand what's in this + + align:start position:0% +he wanted to understand what's in this + + + align:start position:0% +he wanted to understand what's in this +plasma he's just curious he wants to + + align:start position:0% +plasma he's just curious he wants to + + + align:start position:0% +plasma he's just curious he wants to +know and so what he does is that he + + align:start position:0% +know and so what he does is that he + + + align:start position:0% +know and so what he does is that he +pokes a hole here in this anode right + + align:start position:0% +pokes a hole here in this anode right + + + align:start position:0% +pokes a hole here in this anode right +there's a hole and he lets out a little + + align:start position:0% +there's a hole and he lets out a little + + + align:start position:0% +there's a hole and he lets out a little +of this + + align:start position:0% +of this + + + align:start position:0% +of this +discharge and uh he lets it out and my + + align:start position:0% +discharge and uh he lets it out and my + + + align:start position:0% +discharge and uh he lets it out and my +chalk is breaking and he lets it out and + + align:start position:0% +chalk is breaking and he lets it out and + + + align:start position:0% +chalk is breaking and he lets it out and +way back here he has some kind of a uh a + + align:start position:0% +way back here he has some kind of a uh a + + + align:start position:0% +way back here he has some kind of a uh a +screen a phosphor screen so that not + + align:start position:0% +screen a phosphor screen so that not + + + align:start position:0% +screen a phosphor screen so that not +only does this uh discharge here uh kind + + align:start position:0% +only does this uh discharge here uh kind + + + align:start position:0% +only does this uh discharge here uh kind +of glow as it's moving along but when it + + align:start position:0% +of glow as it's moving along but when it + + + align:start position:0% +of glow as it's moving along but when it +hits the phosphor screen it lights up + + align:start position:0% +hits the phosphor screen it lights up + + + align:start position:0% +hits the phosphor screen it lights up +okay and so that that's nice but then + + align:start position:0% +okay and so that that's nice but then + + + align:start position:0% +okay and so that that's nice but then +what he does is he takes two parallel + + align:start position:0% +what he does is he takes two parallel + + + align:start position:0% +what he does is he takes two parallel +plates and he puts it above and below + + align:start position:0% +plates and he puts it above and below + + + align:start position:0% +plates and he puts it above and below +this luminous beam and there's a + + align:start position:0% +this luminous beam and there's a + + + align:start position:0% +this luminous beam and there's a +positive charge on one of these and a + + align:start position:0% +positive charge on one of these and a + + + align:start position:0% +positive charge on one of these and a +negative charge on the other and Lan + + align:start position:0% +negative charge on the other and Lan + + + align:start position:0% +negative charge on the other and Lan +behold when he increases this potential + + align:start position:0% +behold when he increases this potential + + + align:start position:0% +behold when he increases this potential +difference this Delta V what happens is + + align:start position:0% +difference this Delta V what happens is + + + align:start position:0% +difference this Delta V what happens is +that this luminous beam some of that + + align:start position:0% +that this luminous beam some of that + + + align:start position:0% +that this luminous beam some of that +luminous beam is actually deflected a + + align:start position:0% +luminous beam is actually deflected a + + + align:start position:0% +luminous beam is actually deflected a +little bit and so now there's another + + align:start position:0% +little bit and so now there's another + + + align:start position:0% +little bit and so now there's another +very bright + + align:start position:0% +very bright + + + align:start position:0% +very bright +spot and he can measure this uh + + align:start position:0% +spot and he can measure this uh + + + align:start position:0% +spot and he can measure this uh +deflection and we're going to call it + + align:start position:0% +deflection and we're going to call it + + + align:start position:0% +deflection and we're going to call it +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X now since some of this luminous beam + + align:start position:0% +X now since some of this luminous beam + + + align:start position:0% +X now since some of this luminous beam +was deflected toward positively charged + + align:start position:0% +was deflected toward positively charged + + + align:start position:0% +was deflected toward positively charged +plate what kind of particles did he + + align:start position:0% +plate what kind of particles did he + + + align:start position:0% +plate what kind of particles did he +decide were in this luminous + + align:start position:0% +decide were in this luminous + + + align:start position:0% +decide were in this luminous +beam negatives particles because they're + + align:start position:0% +beam negatives particles because they're + + + align:start position:0% +beam negatives particles because they're +attracted to the positively charged + + align:start position:0% +attracted to the positively charged + + + align:start position:0% +attracted to the positively charged +plate so we called this deflection Delta + + align:start position:0% +plate so we called this deflection Delta + + + align:start position:0% +plate so we called this deflection Delta +X we'll call it Delta x sub + + align:start position:0% +X we'll call it Delta x sub + + + align:start position:0% +X we'll call it Delta x sub +minus now he knew enough + + align:start position:0% +minus now he knew enough + + + align:start position:0% +minus now he knew enough +electromagnetism at that + + align:start position:0% +electromagnetism at that + + + align:start position:0% +electromagnetism at that +time to realize that the amount of that + + align:start position:0% +time to realize that the amount of that + + + align:start position:0% +time to realize that the amount of that +deflection has to be directly + + align:start position:0% +deflection has to be directly + + + align:start position:0% +deflection has to be directly +proportional to how much charge was on + + align:start position:0% +proportional to how much charge was on + + + align:start position:0% +proportional to how much charge was on +the negatively charged particle and I'm + + align:start position:0% +the negatively charged particle and I'm + + + align:start position:0% +the negatively charged particle and I'm +going to call that e sub minus because + + align:start position:0% +going to call that e sub minus because + + + align:start position:0% +going to call that e sub minus because +the more charge the easier it would be + + align:start position:0% +the more charge the easier it would be + + + align:start position:0% +the more charge the easier it would be +to deflect + + align:start position:0% +to deflect + + + align:start position:0% +to deflect +it and he recognized that the amount of + + align:start position:0% +it and he recognized that the amount of + + + align:start position:0% +it and he recognized that the amount of +deflection has to be inversely + + align:start position:0% +deflection has to be inversely + + + align:start position:0% +deflection has to be inversely +proportional to the mass of that + + align:start position:0% +proportional to the mass of that + + + align:start position:0% +proportional to the mass of that +negatively charged particle because + + align:start position:0% +negatively charged particle because + + + align:start position:0% +negatively charged particle because +after all the more massive that was the + + align:start position:0% +after all the more massive that was the + + + align:start position:0% +after all the more massive that was the +more difficult it was going to be to + + align:start position:0% +more difficult it was going to be to + + + align:start position:0% +more difficult it was going to be to +deflect it + + align:start position:0% +deflect it + + + align:start position:0% +deflect it +right and then what he did is he cranked + + align:start position:0% +right and then what he did is he cranked + + + align:start position:0% +right and then what he did is he cranked +up Delta v as much as he could and here + + align:start position:0% +up Delta v as much as he could and here + + + align:start position:0% +up Delta v as much as he could and here +I'm taking a little liberty with the + + align:start position:0% +I'm taking a little liberty with the + + + align:start position:0% +I'm taking a little liberty with the +story but I'm telling you essentially + + align:start position:0% +story but I'm telling you essentially + + + align:start position:0% +story but I'm telling you essentially +the essence of the experiment but it's a + + align:start position:0% +the essence of the experiment but it's a + + + align:start position:0% +the essence of the experiment but it's a +little more complicated than what it is + + align:start position:0% +little more complicated than what it is + + + align:start position:0% +little more complicated than what it is +I'm going to tell you right here but he + + align:start position:0% +I'm going to tell you right here but he + + + align:start position:0% +I'm going to tell you right here but he +cranked that + + align:start position:0% +cranked that + + + align:start position:0% +cranked that +up and when he did he realized that + + align:start position:0% +up and when he did he realized that + + + align:start position:0% +up and when he did he realized that +there actually was some other particles + + align:start position:0% +there actually was some other particles + + + align:start position:0% +there actually was some other particles +that were being deflected toward the + + align:start position:0% +that were being deflected toward the + + + align:start position:0% +that were being deflected toward the +negatively charged plate just a little + + align:start position:0% +negatively charged plate just a little + + + align:start position:0% +negatively charged plate just a little +bit all right not a lot just a little + + align:start position:0% +bit all right not a lot just a little + + + align:start position:0% +bit all right not a lot just a little +bit and again he could measure that + + align:start position:0% +bit and again he could measure that + + + align:start position:0% +bit and again he could measure that +deflection and he called that or we're + + align:start position:0% +deflection and he called that or we're + + + align:start position:0% +deflection and he called that or we're +going to call that Delta x sub plus all + + align:start position:0% +going to call that Delta x sub plus all + + + align:start position:0% +going to call that Delta x sub plus all +right these got to be positively charged + + align:start position:0% +right these got to be positively charged + + + align:start position:0% +right these got to be positively charged +particles because they're attracted to + + align:start position:0% +particles because they're attracted to + + + align:start position:0% +particles because they're attracted to +the negatively charged plate and again + + align:start position:0% +the negatively charged plate and again + + + align:start position:0% +the negatively charged plate and again +he realized that Delta x sub plus is + + align:start position:0% +he realized that Delta x sub plus is + + + align:start position:0% +he realized that Delta x sub plus is +proportional to the charge on that + + align:start position:0% +proportional to the charge on that + + + align:start position:0% +proportional to the charge on that +positively charged particle and + + align:start position:0% +positively charged particle and + + + align:start position:0% +positively charged particle and +inversely proportional to the mass of + + align:start position:0% +inversely proportional to the mass of + + + align:start position:0% +inversely proportional to the mass of +that positively charged + + align:start position:0% +that positively charged + + + align:start position:0% +that positively charged +particle all right but now here comes + + align:start position:0% +particle all right but now here comes + + + align:start position:0% +particle all right but now here comes +his + + align:start position:0% + + + + align:start position:0% + +thinking what he + + align:start position:0% +thinking what he + + + align:start position:0% +thinking what he +guessed is that these positively charged + + align:start position:0% +guessed is that these positively charged + + + align:start position:0% +guessed is that these positively charged +particles he guessed that they were + + align:start position:0% +particles he guessed that they were + + + align:start position:0% +particles he guessed that they were +H+ a hydrogen ion how did he know that + + align:start position:0% +H+ a hydrogen ion how did he know that + + + align:start position:0% +H+ a hydrogen ion how did he know that +well this is a guess + + align:start position:0% +well this is a guess + + + align:start position:0% +well this is a guess +however he did know that in this plasma + + align:start position:0% +however he did know that in this plasma + + + align:start position:0% +however he did know that in this plasma +this + + align:start position:0% +this + + + align:start position:0% +this +discharge that there were hydrogen atoms + + align:start position:0% +discharge that there were hydrogen atoms + + + align:start position:0% +discharge that there were hydrogen atoms +and how he knew that is something we're + + align:start position:0% +and how he knew that is something we're + + + align:start position:0% +and how he knew that is something we're +going to talk about in a few days but he + + align:start position:0% +going to talk about in a few days but he + + + align:start position:0% +going to talk about in a few days but he +knew that he also knew h plus h here + + align:start position:0% +knew that he also knew h plus h here + + + align:start position:0% +knew that he also knew h plus h here +these hydrogen atoms that are produced + + align:start position:0% +these hydrogen atoms that are produced + + + align:start position:0% +these hydrogen atoms that are produced +in the plasma somehow the plasma breaks + + align:start position:0% +in the plasma somehow the plasma breaks + + + align:start position:0% +in the plasma somehow the plasma breaks +the H2 Bond these hydrogen atoms were + + align:start position:0% +the H2 Bond these hydrogen atoms were + + + align:start position:0% +the H2 Bond these hydrogen atoms were +neutral okay and so he said well if it's + + align:start position:0% +neutral okay and so he said well if it's + + + align:start position:0% +neutral okay and so he said well if it's +a positively charged Char particle well + + align:start position:0% +a positively charged Char particle well + + + align:start position:0% +a positively charged Char particle well +gee you know it must be that something + + align:start position:0% +gee you know it must be that something + + + align:start position:0% +gee you know it must be that something +was removed from the hydrogen atom to + + align:start position:0% +was removed from the hydrogen atom to + + + align:start position:0% +was removed from the hydrogen atom to +make it positively charged and that + + align:start position:0% +make it positively charged and that + + + align:start position:0% +make it positively charged and that +something must be this negatively + + align:start position:0% +something must be this negatively + + + align:start position:0% +something must be this negatively +charged particle that I'm + + align:start position:0% +charged particle that I'm + + + align:start position:0% +charged particle that I'm +observing okay because I know that + + align:start position:0% +observing okay because I know that + + + align:start position:0% +observing okay because I know that +originally right the hydrogen atom has + + align:start position:0% +originally right the hydrogen atom has + + + align:start position:0% +originally right the hydrogen atom has +to be neutral so therefore I'm going to + + align:start position:0% +to be neutral so therefore I'm going to + + + align:start position:0% +to be neutral so therefore I'm going to +guess that the + + align:start position:0% +guess that the + + + align:start position:0% +guess that the +magnitude of the charge on the + + align:start position:0% +magnitude of the charge on the + + + align:start position:0% +magnitude of the charge on the +negatively charged particle is equal to + + align:start position:0% +negatively charged particle is equal to + + + align:start position:0% +negatively charged particle is equal to +the magnitude of the charge on that + + align:start position:0% +the magnitude of the charge on that + + + align:start position:0% +the magnitude of the charge on that +positively charged + + align:start position:0% +positively charged + + + align:start position:0% +positively charged +particle and if it's that's the case + + align:start position:0% +particle and if it's that's the case + + + align:start position:0% +particle and if it's that's the case +then I can take a ratio here of the + + align:start position:0% +then I can take a ratio here of the + + + align:start position:0% +then I can take a ratio here of the +deflection of the negatively charged + + align:start position:0% +deflection of the negatively charged + + + align:start position:0% +deflection of the negatively charged +particle to the deflection on the + + align:start position:0% +particle to the deflection on the + + + align:start position:0% +particle to the deflection on the +positively charged particle and since + + align:start position:0% +positively charged particle and since + + + align:start position:0% +positively charged particle and since +these two are equal I'm guessing that + + align:start position:0% +these two are equal I'm guessing that + + + align:start position:0% +these two are equal I'm guessing that +since these two are equal well then this + + align:start position:0% +since these two are equal well then this + + + align:start position:0% +since these two are equal well then this +ratio has to just be equal to the mass + + align:start position:0% +ratio has to just be equal to the mass + + + align:start position:0% +ratio has to just be equal to the mass +of that positively charged hydrogen atom + + align:start position:0% +of that positively charged hydrogen atom + + + align:start position:0% +of that positively charged hydrogen atom +to the mass of that negatively charged + + align:start position:0% +to the mass of that negatively charged + + + align:start position:0% +to the mass of that negatively charged +uh particle all + + align:start position:0% +uh particle all + + + align:start position:0% +uh particle all +right and now here's the important point + + align:start position:0% +right and now here's the important point + + + align:start position:0% +right and now here's the important point +the important point is that no matter + + align:start position:0% +the important point is that no matter + + + align:start position:0% +the important point is that no matter +how he made these + + align:start position:0% +how he made these + + + align:start position:0% +how he made these +measurements no matter how he did that + + align:start position:0% +measurements no matter how he did that + + + align:start position:0% +measurements no matter how he did that +the deflection for that negatively + + align:start position:0% +the deflection for that negatively + + + align:start position:0% +the deflection for that negatively +charged particle was much much much + + align:start position:0% +charged particle was much much much + + + align:start position:0% +charged particle was much much much +larger than the def flection for that + + align:start position:0% +larger than the def flection for that + + + align:start position:0% +larger than the def flection for that +positively charged + + align:start position:0% +positively charged + + + align:start position:0% +positively charged +particle that then meant that the mass + + align:start position:0% +particle that then meant that the mass + + + align:start position:0% +particle that then meant that the mass +of this positively charged particle + + align:start position:0% +of this positively charged particle + + + align:start position:0% +of this positively charged particle +which he guessed to be hydrogen atom + + align:start position:0% +which he guessed to be hydrogen atom + + + align:start position:0% +which he guessed to be hydrogen atom +right that must be much much larger than + + align:start position:0% +right that must be much much larger than + + + align:start position:0% +right that must be much much larger than +the mass of the negatively charged + + align:start position:0% +the mass of the negatively charged + + + align:start position:0% +the mass of the negatively charged +particle but he also knew that at that + + align:start position:0% +particle but he also knew that at that + + + align:start position:0% +particle but he also knew that at that +time that a hydrogen atom was the least + + align:start position:0% +time that a hydrogen atom was the least + + + align:start position:0% +time that a hydrogen atom was the least +massive atom but here's an + + align:start position:0% +massive atom but here's an + + + align:start position:0% +massive atom but here's an +experiment that showed that there was a + + align:start position:0% +experiment that showed that there was a + + + align:start position:0% +experiment that showed that there was a +particle that was less massive than a + + align:start position:0% +particle that was less massive than a + + + align:start position:0% +particle that was less massive than a +hydrogen atom hey but you know up to + + align:start position:0% +hydrogen atom hey but you know up to + + + align:start position:0% +hydrogen atom hey but you know up to +then it was the atom is the most basic + + align:start position:0% +then it was the atom is the most basic + + + align:start position:0% +then it was the atom is the most basic +constituent of matter you can't chop it + + align:start position:0% +constituent of matter you can't chop it + + + align:start position:0% +constituent of matter you can't chop it +up anymore but here was the evidence + + align:start position:0% +up anymore but here was the evidence + + + align:start position:0% +up anymore but here was the evidence +that there was a particle less massive + + align:start position:0% +that there was a particle less massive + + + align:start position:0% +that there was a particle less massive +than the hydrogen atom eventually it's + + align:start position:0% +than the hydrogen atom eventually it's + + + align:start position:0% +than the hydrogen atom eventually it's +called an electron but this is the first + + align:start position:0% +called an electron but this is the first + + + align:start position:0% +called an electron but this is the first +evidence here that the atom wasn't the + + align:start position:0% +evidence here that the atom wasn't the + + + align:start position:0% +evidence here that the atom wasn't the +most basic constituent of + + align:start position:0% +most basic constituent of + + + align:start position:0% +most basic constituent of +matter now it actually took another 10 + + align:start position:0% +matter now it actually took another 10 + + + align:start position:0% +matter now it actually took another 10 +years with the Milan oil drop experiment + + align:start position:0% +years with the Milan oil drop experiment + + + align:start position:0% +years with the Milan oil drop experiment +to actually measure this ratio correctly + + align:start position:0% +to actually measure this ratio correctly + + + align:start position:0% +to actually measure this ratio correctly +and to determine the mass of the + + align:start position:0% +and to determine the mass of the + + + align:start position:0% +and to determine the mass of the +electron we won't go in that into this + + align:start position:0% +electron we won't go in that into this + + + align:start position:0% +electron we won't go in that into this +but this ratio here you probably all + + align:start position:0% +but this ratio here you probably all + + + align:start position:0% +but this ratio here you probably all +know the mass of the electron is about + + align:start position:0% +know the mass of the electron is about + + + align:start position:0% +know the mass of the electron is about +836 times that of the mass of the + + align:start position:0% +836 times that of the mass of the + + + align:start position:0% +836 times that of the mass of the +hydrogen atom or hydrogen atom ion + + align:start position:0% +hydrogen atom or hydrogen atom ion + + + align:start position:0% +hydrogen atom or hydrogen atom ion +okay \ No newline at end of file diff --git a/4BwB43Smu7o.txt b/4BwB43Smu7o.txt new file mode 100644 index 0000000000000000000000000000000000000000..756e512aea0db37f22ed085295c04a75aaab6c43 --- /dev/null +++ b/4BwB43Smu7o.txt @@ -0,0 +1,3544 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer high quality educational + + align:start position:0% +to offer high quality educational + + + align:start position:0% +to offer high quality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu greetings and welcome to 507 + + align:start position:0% +ocw.mit.edu greetings and welcome to 507 + + + align:start position:0% +ocw.mit.edu greetings and welcome to 507 +biochemistry online I'm Dr bdan felish + + align:start position:0% +biochemistry online I'm Dr bdan felish + + + align:start position:0% +biochemistry online I'm Dr bdan felish +let's metabolize some problems today + + align:start position:0% +let's metabolize some problems today + + + align:start position:0% +let's metabolize some problems today +we're going to be talking about problem + + align:start position:0% +we're going to be talking about problem + + + align:start position:0% +we're going to be talking about problem +one of problem set 7 now this is a + + align:start position:0% +one of problem set 7 now this is a + + + align:start position:0% +one of problem set 7 now this is a +problem we are chasing labels through + + align:start position:0% +problem we are chasing labels through + + + align:start position:0% +problem we are chasing labels through +biochemical Pathways although it sounds + + align:start position:0% +biochemical Pathways although it sounds + + + align:start position:0% +biochemical Pathways although it sounds +funny it's actually one of the + + align:start position:0% +funny it's actually one of the + + + align:start position:0% +funny it's actually one of the +established ways through which we can + + align:start position:0% +established ways through which we can + + + align:start position:0% +established ways through which we can +test whether the mechanism we propose + + align:start position:0% +test whether the mechanism we propose + + + align:start position:0% +test whether the mechanism we propose +for these Pathways is in fact consistent + + align:start position:0% +for these Pathways is in fact consistent + + + align:start position:0% +for these Pathways is in fact consistent +with what we observe inside the + + align:start position:0% + + + + align:start position:0% + +cells + + align:start position:0% +cells + + + align:start position:0% +cells +in part A of this problem we're going to + + align:start position:0% +in part A of this problem we're going to + + + align:start position:0% +in part A of this problem we're going to +be looking at glycogen and try to figure + + align:start position:0% +be looking at glycogen and try to figure + + + align:start position:0% +be looking at glycogen and try to figure +out which carbons in glycogen end up + + align:start position:0% +out which carbons in glycogen end up + + + align:start position:0% +out which carbons in glycogen end up +being lost as CO2 in the pyrovate + + align:start position:0% +being lost as CO2 in the pyrovate + + + align:start position:0% +being lost as CO2 in the pyrovate +dehydrogenase step of the metabolism + + align:start position:0% +dehydrogenase step of the metabolism + + + align:start position:0% +dehydrogenase step of the metabolism +here is a Shand representation of + + align:start position:0% +here is a Shand representation of + + + align:start position:0% +here is a Shand representation of +glycogen as you know glycogen is a + + align:start position:0% +glycogen as you know glycogen is a + + + align:start position:0% +glycogen as you know glycogen is a +polymer formed of glucose monomers here + + align:start position:0% +polymer formed of glucose monomers here + + + align:start position:0% +polymer formed of glucose monomers here +is a cyclic form of glucose and in + + align:start position:0% +is a cyclic form of glucose and in + + + align:start position:0% +is a cyclic form of glucose and in +glycogen we have these one4 linkages as + + align:start position:0% +glycogen we have these one4 linkages as + + + align:start position:0% +glycogen we have these one4 linkages as +shown here occasionally we'll have one + + align:start position:0% +shown here occasionally we'll have one + + + align:start position:0% +shown here occasionally we'll have one +six linkages + + align:start position:0% +six linkages + + + align:start position:0% +six linkages +as in the case for branches but for + + align:start position:0% +as in the case for branches but for + + + align:start position:0% +as in the case for branches but for +Simplicity we're not going to represent + + align:start position:0% +Simplicity we're not going to represent + + + align:start position:0% +Simplicity we're not going to represent +them here now we want to figure out + + align:start position:0% +them here now we want to figure out + + + align:start position:0% +them here now we want to figure out +which one of these carbons in glycogen + + align:start position:0% +which one of these carbons in glycogen + + + align:start position:0% +which one of these carbons in glycogen +we can label them starting from here 1 2 + + align:start position:0% +we can label them starting from here 1 2 + + + align:start position:0% +we can label them starting from here 1 2 +3 4 five and six which one of these + + align:start position:0% +3 4 five and six which one of these + + + align:start position:0% +3 4 five and six which one of these +carbons is going to be lost as CO2 in + + align:start position:0% +carbons is going to be lost as CO2 in + + + align:start position:0% +carbons is going to be lost as CO2 in +the pyate dehydrogenase step now let's + + align:start position:0% +the pyate dehydrogenase step now let's + + + align:start position:0% +the pyate dehydrogenase step now let's +take a look at the pyoid dehydrogenase + + align:start position:0% +take a look at the pyoid dehydrogenase + + + align:start position:0% +take a look at the pyoid dehydrogenase +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +as you remember one of the endings of + + align:start position:0% +as you remember one of the endings of + + + align:start position:0% +as you remember one of the endings of +glycolysis is the pyate de hydrogenous + + align:start position:0% +glycolysis is the pyate de hydrogenous + + + align:start position:0% +glycolysis is the pyate de hydrogenous +reaction in which pyate loses a CO2 + + align:start position:0% +reaction in which pyate loses a CO2 + + + align:start position:0% +reaction in which pyate loses a CO2 +molecules and forms atil COA which later + + align:start position:0% +molecules and forms atil COA which later + + + align:start position:0% +molecules and forms atil COA which later +can enter the TCA cycle now this carbon + + align:start position:0% +can enter the TCA cycle now this carbon + + + align:start position:0% +can enter the TCA cycle now this carbon +in the carboxy group of + + align:start position:0% +in the carboxy group of + + + align:start position:0% +in the carboxy group of +pyate going to label with a red dot this + + align:start position:0% +pyate going to label with a red dot this + + + align:start position:0% +pyate going to label with a red dot this +is the carbon that be is being lost as + + align:start position:0% +is the carbon that be is being lost as + + + align:start position:0% +is the carbon that be is being lost as +CO2 so we want to find out which of the + + align:start position:0% +CO2 so we want to find out which of the + + + align:start position:0% +CO2 so we want to find out which of the +carbons in our G ien molecule ends up + + align:start position:0% +carbons in our G ien molecule ends up + + + align:start position:0% +carbons in our G ien molecule ends up +being this red dotted carbon that's + + align:start position:0% +being this red dotted carbon that's + + + align:start position:0% +being this red dotted carbon that's +being lost at + + align:start position:0% +being lost at + + + align:start position:0% +being lost at +CO2 to figure this out we have to + + align:start position:0% +CO2 to figure this out we have to + + + align:start position:0% +CO2 to figure this out we have to +backtrack from pyrovate all the way to + + align:start position:0% +backtrack from pyrovate all the way to + + + align:start position:0% +backtrack from pyrovate all the way to +the beginning of glycolysis to figure + + align:start position:0% +the beginning of glycolysis to figure + + + align:start position:0% +the beginning of glycolysis to figure +out where this carbon is coming + + align:start position:0% +out where this carbon is coming + + + align:start position:0% +out where this carbon is coming +from shown here is a layout of the + + align:start position:0% +from shown here is a layout of the + + + align:start position:0% +from shown here is a layout of the +entire glycolysis Pathways starting from + + align:start position:0% +entire glycolysis Pathways starting from + + + align:start position:0% +entire glycolysis Pathways starting from +glycogen let me walk you through it very + + align:start position:0% +glycogen let me walk you through it very + + + align:start position:0% +glycogen let me walk you through it very +quickly glycogen shown here we shown + + align:start position:0% +quickly glycogen shown here we shown + + + align:start position:0% +quickly glycogen shown here we shown +only a couple of monomers attached to + + align:start position:0% +only a couple of monomers attached to + + + align:start position:0% +only a couple of monomers attached to +the glycogenin + + align:start position:0% +the glycogenin + + + align:start position:0% +the glycogenin +protein it's going to get hydrolized by + + align:start position:0% +protein it's going to get hydrolized by + + + align:start position:0% +protein it's going to get hydrolized by +glycogen phosphor to form glucose one + + align:start position:0% +glycogen phosphor to form glucose one + + + align:start position:0% +glycogen phosphor to form glucose one +phosphate which then mutates to glucose + + align:start position:0% +phosphate which then mutates to glucose + + + align:start position:0% +phosphate which then mutates to glucose +six phosphat shown here and then becomes + + align:start position:0% +six phosphat shown here and then becomes + + + align:start position:0% +six phosphat shown here and then becomes +fructose 6 + + align:start position:0% +fructose 6 + + + align:start position:0% +fructose 6 +phosphate fructose one 6 Bas phosphate + + align:start position:0% +phosphate fructose one 6 Bas phosphate + + + align:start position:0% +phosphate fructose one 6 Bas phosphate +then the alalas reaction splits it into + + align:start position:0% +then the alalas reaction splits it into + + + align:start position:0% +then the alalas reaction splits it into +dihydro acetone phosphate and glycer + + align:start position:0% +dihydro acetone phosphate and glycer + + + align:start position:0% +dihydro acetone phosphate and glycer +alide three phosphate or Gap then the + + align:start position:0% +alide three phosphate or Gap then the + + + align:start position:0% +alide three phosphate or Gap then the +Gap dehydrogenase converts it to 1 to + + align:start position:0% +Gap dehydrogenase converts it to 1 to + + + align:start position:0% +Gap dehydrogenase converts it to 1 to +three bis phosphoglycerate and then we + + align:start position:0% +three bis phosphoglycerate and then we + + + align:start position:0% +three bis phosphoglycerate and then we +go down three phosphoglycerate two + + align:start position:0% +go down three phosphoglycerate two + + + align:start position:0% +go down three phosphoglycerate two +phosphoglycerate phosphino pyate and + + align:start position:0% +phosphoglycerate phosphino pyate and + + + align:start position:0% +phosphoglycerate phosphino pyate and +finally pyate and here I've also written + + align:start position:0% +finally pyate and here I've also written + + + align:start position:0% +finally pyate and here I've also written +the pyate dehydrogenase reaction pyate + + align:start position:0% +the pyate dehydrogenase reaction pyate + + + align:start position:0% +the pyate dehydrogenase reaction pyate +becomes acety COA by losing the CO2 once + + align:start position:0% +becomes acety COA by losing the CO2 once + + + align:start position:0% +becomes acety COA by losing the CO2 once +again this carbon that's lost the CO2 is + + align:start position:0% +again this carbon that's lost the CO2 is + + + align:start position:0% +again this carbon that's lost the CO2 is +the carbon that we want to track so I'm + + align:start position:0% +the carbon that we want to track so I'm + + + align:start position:0% +the carbon that we want to track so I'm +going to put a red dot on it and as we + + align:start position:0% +going to put a red dot on it and as we + + + align:start position:0% +going to put a red dot on it and as we +just said this carbon is the carboxy + + align:start position:0% +just said this carbon is the carboxy + + + align:start position:0% +just said this carbon is the carboxy +group in the + + align:start position:0% +group in the + + + align:start position:0% +group in the +pyrovate so the way to solve this + + align:start position:0% +pyrovate so the way to solve this + + + align:start position:0% +pyrovate so the way to solve this +problem is basically go backwards + + align:start position:0% +problem is basically go backwards + + + align:start position:0% +problem is basically go backwards +through the pathway and figure out where + + align:start position:0% +through the pathway and figure out where + + + align:start position:0% +through the pathway and figure out where +this carbon is coming from in the + + align:start position:0% +this carbon is coming from in the + + + align:start position:0% +this carbon is coming from in the +original glycogen + + align:start position:0% +original glycogen + + + align:start position:0% +original glycogen +molecule for the for these couple of + + align:start position:0% +molecule for the for these couple of + + + align:start position:0% +molecule for the for these couple of +steps it's pretty clear it's going to be + + align:start position:0% +steps it's pretty clear it's going to be + + + align:start position:0% +steps it's pretty clear it's going to be +the carboxy in each one of these + + align:start position:0% +the carboxy in each one of these + + + align:start position:0% +the carboxy in each one of these +molecules all the way to 13 B + + align:start position:0% +molecules all the way to 13 B + + + align:start position:0% +molecules all the way to 13 B +phosphoglycerate right there all right + + align:start position:0% +phosphoglycerate right there all right + + + align:start position:0% +phosphoglycerate right there all right +now this 13B phosphoglyceride is coming + + align:start position:0% +now this 13B phosphoglyceride is coming + + + align:start position:0% +now this 13B phosphoglyceride is coming +from Gap so this carbon is in fact the + + align:start position:0% +from Gap so this carbon is in fact the + + + align:start position:0% +from Gap so this carbon is in fact the +alahh carbon in gap + + align:start position:0% +alahh carbon in gap + + + align:start position:0% +alahh carbon in gap +now as you guys know trios isomerase + + align:start position:0% +now as you guys know trios isomerase + + + align:start position:0% +now as you guys know trios isomerase +interconverts between dihydro acetone + + align:start position:0% +interconverts between dihydro acetone + + + align:start position:0% +interconverts between dihydro acetone +phosphate and GAP so this carbon in + + align:start position:0% +phosphate and GAP so this carbon in + + + align:start position:0% +phosphate and GAP so this carbon in +dihydro acetone phosphate is actually + + align:start position:0% +dihydro acetone phosphate is actually + + + align:start position:0% +dihydro acetone phosphate is actually +this carbon right because the phosphate + + align:start position:0% +this carbon right because the phosphate + + + align:start position:0% +this carbon right because the phosphate +group is going to stay unchanged and + + align:start position:0% +group is going to stay unchanged and + + + align:start position:0% +group is going to stay unchanged and +then the car carbonal group at C2 can + + align:start position:0% +then the car carbonal group at C2 can + + + align:start position:0% +then the car carbonal group at C2 can +interconvert with C1 to form an alahh + + align:start position:0% +interconvert with C1 to form an alahh + + + align:start position:0% +interconvert with C1 to form an alahh +here so any of these two carbons if they + + align:start position:0% +here so any of these two carbons if they + + + align:start position:0% +here so any of these two carbons if they +were labeled they would end up being + + align:start position:0% +were labeled they would end up being + + + align:start position:0% +were labeled they would end up being +lost as CO2 in the P dehydrogenate + + align:start position:0% +lost as CO2 in the P dehydrogenate + + + align:start position:0% +lost as CO2 in the P dehydrogenate +step now if we go backwards in the aler + + align:start position:0% +step now if we go backwards in the aler + + + align:start position:0% +step now if we go backwards in the aler +reaction Gap and + + align:start position:0% +reaction Gap and + + + align:start position:0% +reaction Gap and +dhap when put together these carbons are + + align:start position:0% +dhap when put together these carbons are + + + align:start position:0% +dhap when put together these carbons are +going to be carbons three and + + align:start position:0% +going to be carbons three and + + + align:start position:0% +going to be carbons three and +four so we're calling here 1 2 3 this is + + align:start position:0% +four so we're calling here 1 2 3 this is + + + align:start position:0% +four so we're calling here 1 2 3 this is +the carbon that comes from dihydro acone + + align:start position:0% +the carbon that comes from dihydro acone + + + align:start position:0% +the carbon that comes from dihydro acone +phosphate and this is the carbon that + + align:start position:0% +phosphate and this is the carbon that + + + align:start position:0% +phosphate and this is the carbon that +comes from Gap so carbon 3 and four and + + align:start position:0% +comes from Gap so carbon 3 and four and + + + align:start position:0% +comes from Gap so carbon 3 and four and +obviously they're going to be staying + + align:start position:0% +obviously they're going to be staying + + + align:start position:0% +obviously they're going to be staying +carbons 3 and four all the way back to + + align:start position:0% +carbons 3 and four all the way back to + + + align:start position:0% +carbons 3 and four all the way back to +glucose 1 2 3 and four right there + + align:start position:0% +glucose 1 2 3 and four right there + + + align:start position:0% +glucose 1 2 3 and four right there +and also in glucose one phosphate and + + align:start position:0% +and also in glucose one phosphate and + + + align:start position:0% +and also in glucose one phosphate and +consequently in glycogen as + + align:start position:0% +consequently in glycogen as + + + align:start position:0% +consequently in glycogen as +well so to answer part + + align:start position:0% +well so to answer part + + + align:start position:0% +well so to answer part +one + + align:start position:0% +one + + + align:start position:0% +one +uh we can now write here that carbon's + + align:start position:0% +uh we can now write here that carbon's + + + align:start position:0% +uh we can now write here that carbon's +three and four + + align:start position:0% +three and four + + + align:start position:0% +three and four +of glycogen are going to be lost at the + + align:start position:0% +of glycogen are going to be lost at the + + + align:start position:0% +of glycogen are going to be lost at the +pyate dehydrogenate step as carbon + + align:start position:0% + + + + align:start position:0% + +dioxide Part B of the problem deals with + + align:start position:0% +dioxide Part B of the problem deals with + + + align:start position:0% +dioxide Part B of the problem deals with +the metabolism of glycerol as you know + + align:start position:0% +the metabolism of glycerol as you know + + + align:start position:0% +the metabolism of glycerol as you know +glycerol is formed by the hydrolysis of + + align:start position:0% +glycerol is formed by the hydrolysis of + + + align:start position:0% +glycerol is formed by the hydrolysis of +trial glycerides now we are asked to + + align:start position:0% +trial glycerides now we are asked to + + + align:start position:0% +trial glycerides now we are asked to +trace a label from the C2 carbon of + + align:start position:0% +trace a label from the C2 carbon of + + + align:start position:0% +trace a label from the C2 carbon of +glycerol all the way to the first step + + align:start position:0% +glycerol all the way to the first step + + + align:start position:0% +glycerol all the way to the first step +in which this carbon is lost as carbon + + align:start position:0% +in which this carbon is lost as carbon + + + align:start position:0% +in which this carbon is lost as carbon +dioxide let's first take a look at the + + align:start position:0% +dioxide let's first take a look at the + + + align:start position:0% +dioxide let's first take a look at the +metabolism of + + align:start position:0% +metabolism of + + + align:start position:0% +metabolism of +glycerol as I've shown here trial + + align:start position:0% +glycerol as I've shown here trial + + + align:start position:0% +glycerol as I've shown here trial +glycerides can be hydrolized to form + + align:start position:0% +glycerides can be hydrolized to form + + + align:start position:0% +glycerides can be hydrolized to form +glycerol which is 1 2 3 propane triol + + align:start position:0% +glycerol which is 1 2 3 propane triol + + + align:start position:0% +glycerol which is 1 2 3 propane triol +now as you know glycerol is metabolized + + align:start position:0% +now as you know glycerol is metabolized + + + align:start position:0% +now as you know glycerol is metabolized +in two steps first we have a glycerol + + align:start position:0% +in two steps first we have a glycerol + + + align:start position:0% +in two steps first we have a glycerol +kinase that's going to form a glycerol + + align:start position:0% +kinase that's going to form a glycerol + + + align:start position:0% +kinase that's going to form a glycerol +three phosphate as shown here and then + + align:start position:0% +three phosphate as shown here and then + + + align:start position:0% +three phosphate as shown here and then +we're going to use a dehydrogenase that + + align:start position:0% +we're going to use a dehydrogenase that + + + align:start position:0% +we're going to use a dehydrogenase that +uses NAD to oxidize the second carbon of + + align:start position:0% +uses NAD to oxidize the second carbon of + + + align:start position:0% +uses NAD to oxidize the second carbon of +glycerol to dihydro acetone phosphate + + align:start position:0% +glycerol to dihydro acetone phosphate + + + align:start position:0% +glycerol to dihydro acetone phosphate +then it can enter + + align:start position:0% +then it can enter + + + align:start position:0% +then it can enter +glycolysis very conveniently right here + + align:start position:0% +glycolysis very conveniently right here + + + align:start position:0% +glycolysis very conveniently right here +and then it's going to continue getting + + align:start position:0% +and then it's going to continue getting + + + align:start position:0% +and then it's going to continue getting +metabolized towards pyrovate and atil + + align:start position:0% +metabolized towards pyrovate and atil + + + align:start position:0% +metabolized towards pyrovate and atil +COA as as we've seen + + align:start position:0% +COA as as we've seen + + + align:start position:0% +COA as as we've seen +before now the second carbon and + + align:start position:0% +before now the second carbon and + + + align:start position:0% +before now the second carbon and +glycerol is C2 right here I'm going to + + align:start position:0% +glycerol is C2 right here I'm going to + + + align:start position:0% +glycerol is C2 right here I'm going to +mark it with a + + align:start position:0% +mark it with a + + + align:start position:0% +mark it with a +blue + + align:start position:0% +blue + + + align:start position:0% +blue +square so this carbon is right here and + + align:start position:0% +square so this carbon is right here and + + + align:start position:0% +square so this carbon is right here and +it's going to end up right + + align:start position:0% +it's going to end up right + + + align:start position:0% +it's going to end up right +there + + align:start position:0% +there + + + align:start position:0% +there +now this second carbon in diydrone + + align:start position:0% +now this second carbon in diydrone + + + align:start position:0% +now this second carbon in diydrone +phosphate it's going to be the second + + align:start position:0% +phosphate it's going to be the second + + + align:start position:0% +phosphate it's going to be the second +carbon in gap and then second carbon + + align:start position:0% +carbon in gap and then second carbon + + + align:start position:0% +carbon in gap and then second carbon +here here + + align:start position:0% +here here + + + align:start position:0% +here here +here isn't this + + align:start position:0% +here isn't this + + + align:start position:0% +here isn't this +fun then the second carbon in pyate now + + align:start position:0% +fun then the second carbon in pyate now + + + align:start position:0% +fun then the second carbon in pyate now +once the pyate decarbox silat then it's + + align:start position:0% +once the pyate decarbox silat then it's + + + align:start position:0% +once the pyate decarbox silat then it's +going to be the carbonal of acetyl COA + + align:start position:0% +going to be the carbonal of acetyl COA + + + align:start position:0% +going to be the carbonal of acetyl COA +it's this carbon right here now so far + + align:start position:0% +it's this carbon right here now so far + + + align:start position:0% +it's this carbon right here now so far +this carbon has followed the metabolic + + align:start position:0% +this carbon has followed the metabolic + + + align:start position:0% +this carbon has followed the metabolic +pathway but it has not left yet right as + + align:start position:0% +pathway but it has not left yet right as + + + align:start position:0% +pathway but it has not left yet right as +CO2 now what happens to atil COA it's + + align:start position:0% +CO2 now what happens to atil COA it's + + + align:start position:0% +CO2 now what happens to atil COA it's +going to enter the TCA cycle now let's + + align:start position:0% +going to enter the TCA cycle now let's + + + align:start position:0% +going to enter the TCA cycle now let's +take a look at the TCA cycle as we just + + align:start position:0% +take a look at the TCA cycle as we just + + + align:start position:0% +take a look at the TCA cycle as we just +said we're looking now at the + + align:start position:0% +said we're looking now at the + + + align:start position:0% +said we're looking now at the +carbon the first carbon in AEL COA here + + align:start position:0% +carbon the first carbon in AEL COA here + + + align:start position:0% +carbon the first carbon in AEL COA here +the carbon that has the carbonal group + + align:start position:0% +the carbon that has the carbonal group + + + align:start position:0% +the carbon that has the carbonal group +on so as I've shown here in the TCA + + align:start position:0% +on so as I've shown here in the TCA + + + align:start position:0% +on so as I've shown here in the TCA +cycle the the two carbons in acety COA + + align:start position:0% +cycle the the two carbons in acety COA + + + align:start position:0% +cycle the the two carbons in acety COA +are marked with this red line and they + + align:start position:0% +are marked with this red line and they + + + align:start position:0% +are marked with this red line and they +will + + align:start position:0% +will + + + align:start position:0% +will +enter uh and combine with oxaloacetate + + align:start position:0% +enter uh and combine with oxaloacetate + + + align:start position:0% +enter uh and combine with oxaloacetate +to form citrate then citrate isomerizes + + align:start position:0% +to form citrate then citrate isomerizes + + + align:start position:0% +to form citrate then citrate isomerizes +to isocitrate then we're going to lose a + + align:start position:0% +to isocitrate then we're going to lose a + + + align:start position:0% +to isocitrate then we're going to lose a +CO2 molecule which is this middle guy to + + align:start position:0% +CO2 molecule which is this middle guy to + + + align:start position:0% +CO2 molecule which is this middle guy to +form Alpha ketoglutarate but notice the + + align:start position:0% +form Alpha ketoglutarate but notice the + + + align:start position:0% +form Alpha ketoglutarate but notice the +two carbons from actil COA are still in + + align:start position:0% +two carbons from actil COA are still in + + + align:start position:0% +two carbons from actil COA are still in +the molecule then we're going to lose + + align:start position:0% +the molecule then we're going to lose + + + align:start position:0% +the molecule then we're going to lose +another CO2 is this bottom one to form + + align:start position:0% +another CO2 is this bottom one to form + + + align:start position:0% +another CO2 is this bottom one to form +suil COA but once again the two carbons + + align:start position:0% +suil COA but once again the two carbons + + + align:start position:0% +suil COA but once again the two carbons +that came from a COA are still here so + + align:start position:0% +that came from a COA are still here so + + + align:start position:0% +that came from a COA are still here so +in the first TCA cycle none of the CO2 + + align:start position:0% +in the first TCA cycle none of the CO2 + + + align:start position:0% +in the first TCA cycle none of the CO2 +will contain the label that came from + + align:start position:0% +will contain the label that came from + + + align:start position:0% +will contain the label that came from +the from the + + align:start position:0% +the from the + + + align:start position:0% +the from the +glycerol now as we go through the + + align:start position:0% +glycerol now as we go through the + + + align:start position:0% +glycerol now as we go through the +through the TCA cycle we reach this step + + align:start position:0% +through the TCA cycle we reach this step + + + align:start position:0% +through the TCA cycle we reach this step +where is suxin now here I stopped + + align:start position:0% +where is suxin now here I stopped + + + align:start position:0% +where is suxin now here I stopped +putting this red mark because succinate + + align:start position:0% +putting this red mark because succinate + + + align:start position:0% +putting this red mark because succinate +is a symmetric molecule so therefore if + + align:start position:0% +is a symmetric molecule so therefore if + + + align:start position:0% +is a symmetric molecule so therefore if +these two carbons were coming from atil + + align:start position:0% +these two carbons were coming from atil + + + align:start position:0% +these two carbons were coming from atil +Co at this point they will SC ramble so + + align:start position:0% +Co at this point they will SC ramble so + + + align:start position:0% +Co at this point they will SC ramble so +we won't be able to tell whether it was + + align:start position:0% +we won't be able to tell whether it was + + + align:start position:0% +we won't be able to tell whether it was +these two carbons or these two carbons + + align:start position:0% +these two carbons or these two carbons + + + align:start position:0% +these two carbons or these two carbons +all right now let me backtrack and put + + align:start position:0% +all right now let me backtrack and put + + + align:start position:0% +all right now let me backtrack and put +in the labels so astil COA we have this + + align:start position:0% +in the labels so astil COA we have this + + + align:start position:0% +in the labels so astil COA we have this +carbon came from the C2 of glycerol so + + align:start position:0% +carbon came from the C2 of glycerol so + + + align:start position:0% +carbon came from the C2 of glycerol so +we'll find it in this carbon this carbon + + align:start position:0% +we'll find it in this carbon this carbon + + + align:start position:0% +we'll find it in this carbon this carbon +this carbon this carbon all right now we + + align:start position:0% +this carbon this carbon all right now we + + + align:start position:0% +this carbon this carbon all right now we +get to the succinate step and we said + + align:start position:0% +get to the succinate step and we said + + + align:start position:0% +get to the succinate step and we said +well it was here this would be the + + align:start position:0% +well it was here this would be the + + + align:start position:0% +well it was here this would be the +carbon that corresponds to toxil COA but + + align:start position:0% +carbon that corresponds to toxil COA but + + + align:start position:0% +carbon that corresponds to toxil COA but +because this molecule is symmetric by + + align:start position:0% +because this molecule is symmetric by + + + align:start position:0% +because this molecule is symmetric by +the time we get to the malate step to + + align:start position:0% +the time we get to the malate step to + + + align:start position:0% +the time we get to the malate step to +add this hydroxy group it's going to be + + align:start position:0% +add this hydroxy group it's going to be + + + align:start position:0% +add this hydroxy group it's going to be +to the carbon next to the label or the + + align:start position:0% +to the carbon next to the label or the + + + align:start position:0% +to the carbon next to the label or the +carbon further from the label now + + align:start position:0% +carbon further from the label now + + + align:start position:0% +carbon further from the label now +because the molecule is symmetric we + + align:start position:0% +because the molecule is symmetric we + + + align:start position:0% +because the molecule is symmetric we +can't the the ferase enzyme cannot tell + + align:start position:0% +can't the the ferase enzyme cannot tell + + + align:start position:0% +can't the the ferase enzyme cannot tell +which carbon was labeled and which + + align:start position:0% +which carbon was labeled and which + + + align:start position:0% +which carbon was labeled and which +wasn't so therefore malate is going to + + align:start position:0% +wasn't so therefore malate is going to + + + align:start position:0% +wasn't so therefore malate is going to +be half of the molecules is going to + + align:start position:0% +be half of the molecules is going to + + + align:start position:0% +be half of the molecules is going to +have the label on this carbon and half + + align:start position:0% +have the label on this carbon and half + + + align:start position:0% +have the label on this carbon and half +is going to have the label on this + + align:start position:0% +is going to have the label on this + + + align:start position:0% +is going to have the label on this +carbon so I'm going to write like 1 12 + + align:start position:0% +carbon so I'm going to write like 1 12 + + + align:start position:0% +carbon so I'm going to write like 1 12 +square and 1 12 square similarly when we + + align:start position:0% +square and 1 12 square similarly when we + + + align:start position:0% +square and 1 12 square similarly when we +get to oxaloacetate the label is + + align:start position:0% +get to oxaloacetate the label is + + + align:start position:0% +get to oxaloacetate the label is +distributed half on one uh carboxy group + + align:start position:0% +distributed half on one uh carboxy group + + + align:start position:0% +distributed half on one uh carboxy group +and the other half is going to be on the + + align:start position:0% +and the other half is going to be on the + + + align:start position:0% +and the other half is going to be on the +other carboxy + + align:start position:0% +other carboxy + + + align:start position:0% +other carboxy +group all right now so we've gone + + align:start position:0% +group all right now so we've gone + + + align:start position:0% +group all right now so we've gone +through the TCA cycle once and we have + + align:start position:0% +through the TCA cycle once and we have + + + align:start position:0% +through the TCA cycle once and we have +not lost the carbon that came from the + + align:start position:0% +not lost the carbon that came from the + + + align:start position:0% +not lost the carbon that came from the +glycerol but look what happens when we + + align:start position:0% +glycerol but look what happens when we + + + align:start position:0% +glycerol but look what happens when we +continue the TCA cycle a second time so + + align:start position:0% +continue the TCA cycle a second time so + + + align:start position:0% +continue the TCA cycle a second time so +now let's say we combine with an astil + + align:start position:0% +now let's say we combine with an astil + + + align:start position:0% +now let's say we combine with an astil +COA that doesn't have any label at all + + align:start position:0% +COA that doesn't have any label at all + + + align:start position:0% +COA that doesn't have any label at all +now these two carboxy groups are going + + align:start position:0% +now these two carboxy groups are going + + + align:start position:0% +now these two carboxy groups are going +to be these two carboxy group in citrate + + align:start position:0% +to be these two carboxy group in citrate + + + align:start position:0% +to be these two carboxy group in citrate +and as we + + align:start position:0% +and as we + + + align:start position:0% +and as we +discussed both of these two groups are + + align:start position:0% +discussed both of these two groups are + + + align:start position:0% +discussed both of these two groups are +going to be lost at CO2 in these two + + align:start position:0% +going to be lost at CO2 in these two + + + align:start position:0% +going to be lost at CO2 in these two +steps first is the middle carboxy group + + align:start position:0% +steps first is the middle carboxy group + + + align:start position:0% +steps first is the middle carboxy group +that's being lost here and this other + + align:start position:0% +that's being lost here and this other + + + align:start position:0% +that's being lost here and this other +carboxy is going to be lost at the alpha + + align:start position:0% +carboxy is going to be lost at the alpha + + + align:start position:0% +carboxy is going to be lost at the alpha +ketoglutarate dehydrogenate step so the + + align:start position:0% +ketoglutarate dehydrogenate step so the + + + align:start position:0% +ketoglutarate dehydrogenate step so the +second time we go through the TCA cycle + + align:start position:0% +second time we go through the TCA cycle + + + align:start position:0% +second time we go through the TCA cycle +we lose half of the label at the isocit + + align:start position:0% +we lose half of the label at the isocit + + + align:start position:0% +we lose half of the label at the isocit +dehydrogenate step and half of the label + + align:start position:0% +dehydrogenate step and half of the label + + + align:start position:0% +dehydrogenate step and half of the label +at the alpha kilog glutarate + + align:start position:0% +at the alpha kilog glutarate + + + align:start position:0% +at the alpha kilog glutarate +dehydrogenate step all right so I can + + align:start position:0% +dehydrogenate step all right so I can + + + align:start position:0% +dehydrogenate step all right so I can +I'm going to circle these so to answer + + align:start position:0% +I'm going to circle these so to answer + + + align:start position:0% +I'm going to circle these so to answer +Part B the C2 carbon of glycerol is + + align:start position:0% +Part B the C2 carbon of glycerol is + + + align:start position:0% +Part B the C2 carbon of glycerol is +going to be lost as CO2 in the TCA cycle + + align:start position:0% +going to be lost as CO2 in the TCA cycle + + + align:start position:0% +going to be lost as CO2 in the TCA cycle +but we have to go once through the cycle + + align:start position:0% +but we have to go once through the cycle + + + align:start position:0% +but we have to go once through the cycle +first through which none of the label + + align:start position:0% +first through which none of the label + + + align:start position:0% +first through which none of the label +will be lost and then at the second time + + align:start position:0% +will be lost and then at the second time + + + align:start position:0% +will be lost and then at the second time +first in the isocitrate dehydrogenase + + align:start position:0% +first in the isocitrate dehydrogenase + + + align:start position:0% +first in the isocitrate dehydrogenase +then at the alpha ketoglutarate + + align:start position:0% +then at the alpha ketoglutarate + + + align:start position:0% +then at the alpha ketoglutarate +dehydrogenase we're going to be losing + + align:start position:0% +dehydrogenase we're going to be losing + + + align:start position:0% +dehydrogenase we're going to be losing +the CO2 that came from the C2 carbon of + + align:start position:0% + + + + align:start position:0% + +glycerol as you might imagine glycerol + + align:start position:0% +glycerol as you might imagine glycerol + + + align:start position:0% +glycerol as you might imagine glycerol +can also be used to produce energy in + + align:start position:0% +can also be used to produce energy in + + + align:start position:0% +can also be used to produce energy in +fact some bacteria can grow on glycerol + + align:start position:0% +fact some bacteria can grow on glycerol + + + align:start position:0% +fact some bacteria can grow on glycerol +using no other carbon Source now in part + + align:start position:0% +using no other carbon Source now in part + + + align:start position:0% +using no other carbon Source now in part +C of the problem we're going to explore + + align:start position:0% +C of the problem we're going to explore + + + align:start position:0% +C of the problem we're going to explore +how much energy we can get from one + + align:start position:0% +how much energy we can get from one + + + align:start position:0% +how much energy we can get from one +molecule of glycerol let's first review + + align:start position:0% +molecule of glycerol let's first review + + + align:start position:0% +molecule of glycerol let's first review +the metabolism of + + align:start position:0% +the metabolism of + + + align:start position:0% +the metabolism of +glycerol as we just discussed glycerol + + align:start position:0% +glycerol as we just discussed glycerol + + + align:start position:0% +glycerol as we just discussed glycerol +enters metabolism with glycerol kisee + + align:start position:0% +enters metabolism with glycerol kisee + + + align:start position:0% +enters metabolism with glycerol kisee +which then in two steps becomes dihydro + + align:start position:0% +which then in two steps becomes dihydro + + + align:start position:0% +which then in two steps becomes dihydro +asone phosphate which can enter + + align:start position:0% +asone phosphate which can enter + + + align:start position:0% +asone phosphate which can enter +glycolysis all the way to pyate and then + + align:start position:0% +glycolysis all the way to pyate and then + + + align:start position:0% +glycolysis all the way to pyate and then +atil COA here the pyate dehydrogenase + + align:start position:0% +atil COA here the pyate dehydrogenase + + + align:start position:0% +atil COA here the pyate dehydrogenase +allows us to lose one + + align:start position:0% +allows us to lose one + + + align:start position:0% +allows us to lose one +CO2 and then atil COA will enter the TCA + + align:start position:0% +CO2 and then atil COA will enter the TCA + + + align:start position:0% +CO2 and then atil COA will enter the TCA +cycle where within one cycle we're going + + align:start position:0% +cycle where within one cycle we're going + + + align:start position:0% +cycle where within one cycle we're going +to lose two more co2's so that's a total + + align:start position:0% +to lose two more co2's so that's a total + + + align:start position:0% +to lose two more co2's so that's a total +of three carbons that we lose and that's + + align:start position:0% +of three carbons that we lose and that's + + + align:start position:0% +of three carbons that we lose and that's +exactly how many carbons we have in + + align:start position:0% +exactly how many carbons we have in + + + align:start position:0% +exactly how many carbons we have in +glycerol now what we need to keep track + + align:start position:0% +glycerol now what we need to keep track + + + align:start position:0% +glycerol now what we need to keep track +in order to evaluate how much energy we + + align:start position:0% +in order to evaluate how much energy we + + + align:start position:0% +in order to evaluate how much energy we +get from one molecule of glycerol is + + align:start position:0% +get from one molecule of glycerol is + + + align:start position:0% +get from one molecule of glycerol is +whenever we need to use ATP for example + + align:start position:0% +whenever we need to use ATP for example + + + align:start position:0% +whenever we need to use ATP for example +we need to put in energy or whenever we + + align:start position:0% +we need to put in energy or whenever we + + + align:start position:0% +we need to put in energy or whenever we +generate nadh or fadh2 molecules that we + + align:start position:0% +generate nadh or fadh2 molecules that we + + + align:start position:0% +generate nadh or fadh2 molecules that we +can then take to the electron transport + + align:start position:0% +can then take to the electron transport + + + align:start position:0% +can then take to the electron transport +chain and generate atps out of them so + + align:start position:0% +chain and generate atps out of them so + + + align:start position:0% +chain and generate atps out of them so +I've put together a list of the steps in + + align:start position:0% +I've put together a list of the steps in + + + align:start position:0% +I've put together a list of the steps in +the pathway where the energy balance is + + align:start position:0% +the pathway where the energy balance is + + + align:start position:0% +the pathway where the energy balance is +affected either we need to use energy or + + align:start position:0% +affected either we need to use energy or + + + align:start position:0% +affected either we need to use energy or +regenerating energy in the form of ATP + + align:start position:0% +regenerating energy in the form of ATP + + + align:start position:0% +regenerating energy in the form of ATP +or in the form of Redux co-actors such + + align:start position:0% +or in the form of Redux co-actors such + + + align:start position:0% +or in the form of Redux co-actors such +as NAD and + + align:start position:0% +as NAD and + + + align:start position:0% +as NAD and +fad all right so the first step glycerol + + align:start position:0% +fad all right so the first step glycerol + + + align:start position:0% +fad all right so the first step glycerol +kinas we're going to need to spend one + + align:start position:0% +kinas we're going to need to spend one + + + align:start position:0% +kinas we're going to need to spend one +molecule of ATP so I'm going to put a + + align:start position:0% +molecule of ATP so I'm going to put a + + + align:start position:0% +molecule of ATP so I'm going to put a +minus one here for ATP equivalent now in + + align:start position:0% +minus one here for ATP equivalent now in + + + align:start position:0% +minus one here for ATP equivalent now in +the glycerol three phosphate + + align:start position:0% +the glycerol three phosphate + + + align:start position:0% +the glycerol three phosphate +dehydrogenate step which is shown right + + align:start position:0% +dehydrogenate step which is shown right + + + align:start position:0% +dehydrogenate step which is shown right +here we're generating one molecule of + + align:start position:0% +here we're generating one molecule of + + + align:start position:0% +here we're generating one molecule of +nadh so plus one + + align:start position:0% +nadh so plus one + + + align:start position:0% +nadh so plus one +nadh + + align:start position:0% +nadh + + + align:start position:0% +nadh +now for the purpose of this problem + + align:start position:0% +now for the purpose of this problem + + + align:start position:0% +now for the purpose of this problem +we're going to use the convention in one + + align:start position:0% +we're going to use the convention in one + + + align:start position:0% +we're going to use the convention in one +nadh is worse about 3 ATP + + align:start position:0% + + + + align:start position:0% + +equivalent now later on in the pathway + + align:start position:0% +equivalent now later on in the pathway + + + align:start position:0% +equivalent now later on in the pathway +we're going to get to the Gap DH step + + align:start position:0% +we're going to get to the Gap DH step + + + align:start position:0% +we're going to get to the Gap DH step +where we generate one more nadh molecule + + align:start position:0% +where we generate one more nadh molecule + + + align:start position:0% +where we generate one more nadh molecule +so Gap d h another nadh molecule that's + + align:start position:0% +so Gap d h another nadh molecule that's + + + align:start position:0% +so Gap d h another nadh molecule that's +equivalent to three + + align:start position:0% +equivalent to three + + + align:start position:0% +equivalent to three +atps now as we're moving ahead we have + + align:start position:0% +atps now as we're moving ahead we have + + + align:start position:0% +atps now as we're moving ahead we have +the phospho glycerate kise step where we + + align:start position:0% +the phospho glycerate kise step where we + + + align:start position:0% +the phospho glycerate kise step where we +generate one ATP and then we have the + + align:start position:0% +generate one ATP and then we have the + + + align:start position:0% +generate one ATP and then we have the +pyrovate K step where generate one more + + align:start position:0% + + + + align:start position:0% + +ATP I have these written here so + one + + align:start position:0% +ATP I have these written here so + one + + + align:start position:0% +ATP I have these written here so + one +ATP and + one + + align:start position:0% +ATP and + one + + + align:start position:0% +ATP and + one +ATP now + + align:start position:0% +ATP now + + + align:start position:0% +ATP now +finally we know the pyate is going to be + + align:start position:0% +finally we know the pyate is going to be + + + align:start position:0% +finally we know the pyate is going to be +decarbox by the pyate dehydrogenase and + + align:start position:0% +decarbox by the pyate dehydrogenase and + + + align:start position:0% +decarbox by the pyate dehydrogenase and +here two we're generating one + + align:start position:0% + + + + align:start position:0% + +nadh so plus one + + align:start position:0% +nadh so plus one + + + align:start position:0% +nadh so plus one +nadh that's going to be equivalent to + + align:start position:0% +nadh that's going to be equivalent to + + + align:start position:0% +nadh that's going to be equivalent to +three atps all right and finally the TCA + + align:start position:0% +three atps all right and finally the TCA + + + align:start position:0% +three atps all right and finally the TCA +cycle now we have one molecule of ail + + align:start position:0% +cycle now we have one molecule of ail + + + align:start position:0% +cycle now we have one molecule of ail +COA that enters the TCA + + align:start position:0% +COA that enters the TCA + + + align:start position:0% +COA that enters the TCA +cycle so + + align:start position:0% +cycle so + + + align:start position:0% +cycle so +as you guys know for every molecule of a + + align:start position:0% +as you guys know for every molecule of a + + + align:start position:0% +as you guys know for every molecule of a +COA enter the TCA cycle we're going to + + align:start position:0% +COA enter the TCA cycle we're going to + + + align:start position:0% +COA enter the TCA cycle we're going to +be generating 1 2 three + + align:start position:0% +be generating 1 2 three + + + align:start position:0% +be generating 1 2 three +nadh's one + + align:start position:0% +nadh's one + + + align:start position:0% +nadh's one +fadh2 and one + + align:start position:0% +fadh2 and one + + + align:start position:0% +fadh2 and one +GTP so the tally is three + + align:start position:0% +GTP so the tally is three + + + align:start position:0% +GTP so the tally is three +nadh one + + align:start position:0% +nadh one + + + align:start position:0% +nadh one +fadh2 and one + + align:start position:0% +fadh2 and one + + + align:start position:0% +fadh2 and one +GTP now GTP is equivalent to an ATP + + align:start position:0% +GTP now GTP is equivalent to an ATP + + + align:start position:0% +GTP now GTP is equivalent to an ATP +fadh2 counts as 2 atps and nadh counts + + align:start position:0% +fadh2 counts as 2 atps and nadh counts + + + align:start position:0% +fadh2 counts as 2 atps and nadh counts +as three atps so that's a grand total of + + align:start position:0% +as three atps so that's a grand total of + + + align:start position:0% +as three atps so that's a grand total of + + align:start position:0% + + + align:start position:0% +atps so putting all of this together for + + align:start position:0% +atps so putting all of this together for + + + align:start position:0% +atps so putting all of this together for +one molecule of glycerol when fully + + align:start position:0% +one molecule of glycerol when fully + + + align:start position:0% +one molecule of glycerol when fully +metabolized to CO2 we get 22 ATP + + align:start position:0% +metabolized to CO2 we get 22 ATP + + + align:start position:0% +metabolized to CO2 we get 22 ATP +equivalents so that's the final answer + + align:start position:0% +equivalents so that's the final answer + + + align:start position:0% +equivalents so that's the final answer +for part C from one molecule of glycerol + + align:start position:0% +for part C from one molecule of glycerol + + + align:start position:0% +for part C from one molecule of glycerol +we get about 22 ATP + + align:start position:0% + + + + align:start position:0% + +equivalents in part D of the proc + + align:start position:0% +equivalents in part D of the proc + + + align:start position:0% +equivalents in part D of the proc +problem we're tracing the same labels we + + align:start position:0% +problem we're tracing the same labels we + + + align:start position:0% +problem we're tracing the same labels we +had in part A but instead of tracing + + align:start position:0% +had in part A but instead of tracing + + + align:start position:0% +had in part A but instead of tracing +them to CO2 we're going to trace them to + + align:start position:0% +them to CO2 we're going to trace them to + + + align:start position:0% +them to CO2 we're going to trace them to +the amino acid + + align:start position:0% +the amino acid + + + align:start position:0% +the amino acid +alanine as you know one way to produce + + align:start position:0% +alanine as you know one way to produce + + + align:start position:0% +alanine as you know one way to produce +alanine is by transamination from pyate + + align:start position:0% +alanine is by transamination from pyate + + + align:start position:0% +alanine is by transamination from pyate +since we already tracked the label to + + align:start position:0% +since we already tracked the label to + + + align:start position:0% +since we already tracked the label to +pyrovate we need to know how do we + + align:start position:0% +pyrovate we need to know how do we + + + align:start position:0% +pyrovate we need to know how do we +convert pyrovate into + + align:start position:0% +convert pyrovate into + + + align:start position:0% +convert pyrovate into +alanine let's take a look at that + + align:start position:0% +alanine let's take a look at that + + + align:start position:0% +alanine let's take a look at that +reaction as you know Alpha keto acid + + align:start position:0% +reaction as you know Alpha keto acid + + + align:start position:0% +reaction as you know Alpha keto acid +such as pyrovate can be converted into + + align:start position:0% +such as pyrovate can be converted into + + + align:start position:0% +such as pyrovate can be converted into +amino acids by a transamination reaction + + align:start position:0% +amino acids by a transamination reaction + + + align:start position:0% +amino acids by a transamination reaction +here we're going to use another amino + + align:start position:0% +here we're going to use another amino + + + align:start position:0% +here we're going to use another amino +acid to donate the amino group to the + + align:start position:0% +acid to donate the amino group to the + + + align:start position:0% +acid to donate the amino group to the +alpha keto acid pyrovate to form alanine + + align:start position:0% +alpha keto acid pyrovate to form alanine + + + align:start position:0% +alpha keto acid pyrovate to form alanine +now all these transamination reactions + + align:start position:0% +now all these transamination reactions + + + align:start position:0% +now all these transamination reactions +are catalized by PLP or peroxy 5 + + align:start position:0% +are catalized by PLP or peroxy 5 + + + align:start position:0% +are catalized by PLP or peroxy 5 +phosphate which is a co-actor derived + + align:start position:0% +phosphate which is a co-actor derived + + + align:start position:0% +phosphate which is a co-actor derived +from vitamin + + align:start position:0% +from vitamin + + + align:start position:0% +from vitamin +B6 so what it's left to WR in this + + align:start position:0% +B6 so what it's left to WR in this + + + align:start position:0% +B6 so what it's left to WR in this +transformation is the other pair of + + align:start position:0% +transformation is the other pair of + + + align:start position:0% +transformation is the other pair of +amino acid Alpha keto acid so basically + + align:start position:0% +amino acid Alpha keto acid so basically + + + align:start position:0% +amino acid Alpha keto acid so basically +where is this amino group coming from + + align:start position:0% +where is this amino group coming from + + + align:start position:0% +where is this amino group coming from +typically for most transaminases the + + align:start position:0% +typically for most transaminases the + + + align:start position:0% +typically for most transaminases the +other pair is glutamate Alpha + + align:start position:0% + + + + align:start position:0% + +ketoglutarate so we going to have + + align:start position:0% +ketoglutarate so we going to have + + + align:start position:0% +ketoglutarate so we going to have +glutamate it's going to donate the amino + + align:start position:0% +glutamate it's going to donate the amino + + + align:start position:0% +glutamate it's going to donate the amino +group and in the process going to become + + align:start position:0% +group and in the process going to become + + + align:start position:0% +group and in the process going to become +an alpha keto acid Alpha keto + + align:start position:0% +an alpha keto acid Alpha keto + + + align:start position:0% +an alpha keto acid Alpha keto +glutarate so in this way pyate becomes + + align:start position:0% +glutarate so in this way pyate becomes + + + align:start position:0% +glutarate so in this way pyate becomes +alanine now we were tracked in the label + + align:start position:0% +alanine now we were tracked in the label + + + align:start position:0% +alanine now we were tracked in the label +from this carbon so the carbon that will + + align:start position:0% +from this carbon so the carbon that will + + + align:start position:0% +from this carbon so the carbon that will +be lost at CO2 in the Pate dehydrogenate + + align:start position:0% +be lost at CO2 in the Pate dehydrogenate + + + align:start position:0% +be lost at CO2 in the Pate dehydrogenate +reaction so that is this carbon right + + align:start position:0% +reaction so that is this carbon right + + + align:start position:0% +reaction so that is this carbon right +here in pyate so in the transamination + + align:start position:0% +here in pyate so in the transamination + + + align:start position:0% +here in pyate so in the transamination +reaction this carbon becomes the carboxy + + align:start position:0% +reaction this carbon becomes the carboxy + + + align:start position:0% +reaction this carbon becomes the carboxy +carbon of + + align:start position:0% +carbon of + + + align:start position:0% +carbon of +alanine so if you were to start with a + + align:start position:0% +alanine so if you were to start with a + + + align:start position:0% +alanine so if you were to start with a +glycogen that was labeled at the three + + align:start position:0% +glycogen that was labeled at the three + + + align:start position:0% +glycogen that was labeled at the three +or four uh the carbons three and four + + align:start position:0% +or four uh the carbons three and four + + + align:start position:0% +or four uh the carbons three and four +that label would be l + + align:start position:0% +that label would be l + + + align:start position:0% +that label would be l +as CO2 in the parv dehydrogenase + + align:start position:0% +as CO2 in the parv dehydrogenase + + + align:start position:0% +as CO2 in the parv dehydrogenase +reaction as we saw in part A but also + + align:start position:0% +reaction as we saw in part A but also + + + align:start position:0% +reaction as we saw in part A but also +that label will be incorporated in + + align:start position:0% +that label will be incorporated in + + + align:start position:0% +that label will be incorporated in +alanine at the carboxy group of this + + align:start position:0% +alanine at the carboxy group of this + + + align:start position:0% +alanine at the carboxy group of this +amino + + align:start position:0% + + + + align:start position:0% + +acid Parts E and F of the problem deal + + align:start position:0% +acid Parts E and F of the problem deal + + + align:start position:0% +acid Parts E and F of the problem deal +with chasing labels to the amino acids + + align:start position:0% +with chasing labels to the amino acids + + + align:start position:0% +with chasing labels to the amino acids +glutamate and aspartate now both of + + align:start position:0% +glutamate and aspartate now both of + + + align:start position:0% +glutamate and aspartate now both of +these amino acids have their + + align:start position:0% +these amino acids have their + + + align:start position:0% +these amino acids have their +corresponding Alpha keto acids as part + + align:start position:0% +corresponding Alpha keto acids as part + + + align:start position:0% +corresponding Alpha keto acids as part +of the TCA cycle so let's first take a + + align:start position:0% +of the TCA cycle so let's first take a + + + align:start position:0% +of the TCA cycle so let's first take a +look at this TCA cycle here we have the + + align:start position:0% +look at this TCA cycle here we have the + + + align:start position:0% +look at this TCA cycle here we have the +TCA cycle where I + + align:start position:0% +TCA cycle where I + + + align:start position:0% +TCA cycle where I +highlighted uh Alpha ketoglutarate going + + align:start position:0% +highlighted uh Alpha ketoglutarate going + + + align:start position:0% +highlighted uh Alpha ketoglutarate going +into glutamate through a transamination + + align:start position:0% +into glutamate through a transamination + + + align:start position:0% +into glutamate through a transamination +reaction Alpha ketoglutarate and Alpha + + align:start position:0% +reaction Alpha ketoglutarate and Alpha + + + align:start position:0% +reaction Alpha ketoglutarate and Alpha +keto acid can undergo a PLP catalyzed + + align:start position:0% +keto acid can undergo a PLP catalyzed + + + align:start position:0% +keto acid can undergo a PLP catalyzed +transamination to form glutamate and + + align:start position:0% +transamination to form glutamate and + + + align:start position:0% +transamination to form glutamate and +similarly oxaloacetate and another Alpha + + align:start position:0% +similarly oxaloacetate and another Alpha + + + align:start position:0% +similarly oxaloacetate and another Alpha +keto acid can trans aminate to form + + align:start position:0% +keto acid can trans aminate to form + + + align:start position:0% +keto acid can trans aminate to form +aspartate now in Part B of the problem + + align:start position:0% +aspartate now in Part B of the problem + + + align:start position:0% +aspartate now in Part B of the problem +we are looking at the label present at + + align:start position:0% +we are looking at the label present at + + + align:start position:0% +we are looking at the label present at +Carbon 1 in actil COA have we said that + + align:start position:0% +Carbon 1 in actil COA have we said that + + + align:start position:0% +Carbon 1 in actil COA have we said that +this label will stay inside the + + align:start position:0% +this label will stay inside the + + + align:start position:0% +this label will stay inside the +intermediates of the TCA cycle for the + + align:start position:0% +intermediates of the TCA cycle for the + + + align:start position:0% +intermediates of the TCA cycle for the +whole round + + align:start position:0% +whole round + + + align:start position:0% +whole round +now when this label gets the alpha + + align:start position:0% +now when this label gets the alpha + + + align:start position:0% +now when this label gets the alpha +ketoglutarate it's going to be on this + + align:start position:0% +ketoglutarate it's going to be on this + + + align:start position:0% +ketoglutarate it's going to be on this +carboxy group so in the transamination + + align:start position:0% +carboxy group so in the transamination + + + align:start position:0% +carboxy group so in the transamination +reaction the label it's going to end + + align:start position:0% +reaction the label it's going to end + + + align:start position:0% +reaction the label it's going to end +completely on the furthermost carboxy in + + align:start position:0% +completely on the furthermost carboxy in + + + align:start position:0% +completely on the furthermost carboxy in +glutamate so that takes care of part e + + align:start position:0% +glutamate so that takes care of part e + + + align:start position:0% +glutamate so that takes care of part e +now if we continue uh facing this label + + align:start position:0% +now if we continue uh facing this label + + + align:start position:0% +now if we continue uh facing this label +once we get to the succinate the label + + align:start position:0% +once we get to the succinate the label + + + align:start position:0% +once we get to the succinate the label +is going to split half and + + align:start position:0% +is going to split half and + + + align:start position:0% +is going to split half and +half between these two carboxy groups + + align:start position:0% +half between these two carboxy groups + + + align:start position:0% +half between these two carboxy groups +because we cannot + + align:start position:0% +because we cannot + + + align:start position:0% +because we cannot +tell uh which one because the molecule + + align:start position:0% +tell uh which one because the molecule + + + align:start position:0% +tell uh which one because the molecule +is going to be symmetric similarly for + + align:start position:0% + + + + align:start position:0% + +fumerate and in malate as + + align:start position:0% + + + + align:start position:0% + +well so in + + align:start position:0% +well so in + + + align:start position:0% +well so in +oxaloacetate the label is going to be on + + align:start position:0% +oxaloacetate the label is going to be on + + + align:start position:0% +oxaloacetate the label is going to be on +both of the carboxy group half of the + + align:start position:0% +both of the carboxy group half of the + + + align:start position:0% +both of the carboxy group half of the +molecules will have it on one half of + + align:start position:0% +molecules will have it on one half of + + + align:start position:0% +molecules will have it on one half of +the molecules will have it on the other + + align:start position:0% +the molecules will have it on the other + + + align:start position:0% +the molecules will have it on the other +so therefore the aspartate is going to + + align:start position:0% +so therefore the aspartate is going to + + + align:start position:0% +so therefore the aspartate is going to +mirror that label distribution half + + align:start position:0% +mirror that label distribution half + + + align:start position:0% +mirror that label distribution half +label on one carboxy half label on the + + align:start position:0% +label on one carboxy half label on the + + + align:start position:0% +label on one carboxy half label on the +other carboxy so that should answer the + + align:start position:0% +other carboxy so that should answer the + + + align:start position:0% +other carboxy so that should answer the +final part of this problem now I hope + + align:start position:0% +final part of this problem now I hope + + + align:start position:0% +final part of this problem now I hope +this problem gave you a better + + align:start position:0% +this problem gave you a better + + + align:start position:0% +this problem gave you a better +understanding of what it means to chase + + align:start position:0% +understanding of what it means to chase + + + align:start position:0% +understanding of what it means to chase +labels to biochemical Pathways and also + + align:start position:0% +labels to biochemical Pathways and also + + + align:start position:0% +labels to biochemical Pathways and also +the chasing labels can help us better + + align:start position:0% +the chasing labels can help us better + + + align:start position:0% +the chasing labels can help us better +understand the mechanism of biochemical + + align:start position:0% +understand the mechanism of biochemical + + + align:start position:0% +understand the mechanism of biochemical +transformations \ No newline at end of file diff --git a/4DX9GM_kZmc.txt b/4DX9GM_kZmc.txt new file mode 100644 index 0000000000000000000000000000000000000000..0323f907e5dbbdd38dce9db7d71afa80574183de --- /dev/null +++ b/4DX9GM_kZmc.txt @@ -0,0 +1,12473 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu I'm going to go through a + + align:start position:0% +ocw.mit.edu I'm going to go through a + + + align:start position:0% +ocw.mit.edu I'm going to go through a +number of cases with you today + + align:start position:0% + + + + align:start position:0% + +so we'll have to rely + + align:start position:0% +so we'll have to rely + + + align:start position:0% +so we'll have to rely +on sometimes on this handout sometimes + + align:start position:0% +on sometimes on this handout sometimes + + + align:start position:0% +on sometimes on this handout sometimes +on the slides let me first tell you what + + align:start position:0% +on the slides let me first tell you what + + + align:start position:0% +on the slides let me first tell you what +the handout is + + align:start position:0% +the handout is + + + align:start position:0% +the handout is +contains the + + align:start position:0% + + + + align:start position:0% + +first is an example from Philip Bon's + + align:start position:0% +first is an example from Philip Bon's + + + align:start position:0% +first is an example from Philip Bon's +book lived in + + align:start position:0% +book lived in + + + align:start position:0% +book lived in +architecture this is the housing for + + align:start position:0% +architecture this is the housing for + + + align:start position:0% +architecture this is the housing for +steel workers at Pak near + + align:start position:0% +steel workers at Pak near + + + align:start position:0% +steel workers at Pak near +bordo which budon studied + + align:start position:0% +bordo which budon studied + + + align:start position:0% +bordo which budon studied +after a large after a period of time and + + align:start position:0% +after a large after a period of time and + + + align:start position:0% +after a large after a period of time and +made these + + align:start position:0% +made these + + + align:start position:0% +made these +drawings of the changes that people had + + align:start position:0% +drawings of the changes that people had + + + align:start position:0% +drawings of the changes that people had +made to the original plan which is the + + align:start position:0% +made to the original plan which is the + + + align:start position:0% +made to the original plan which is the +top + + align:start position:0% +top + + + align:start position:0% +top +left the + + align:start position:0% + + + + align:start position:0% + +elevations indicate a couple of things + + align:start position:0% +elevations indicate a couple of things + + + align:start position:0% +elevations indicate a couple of things +because I'm not going to go into any + + align:start position:0% +because I'm not going to go into any + + + align:start position:0% +because I'm not going to go into any +detail about this + + align:start position:0% +detail about this + + + align:start position:0% +detail about this +example um people enclosed the the open + + align:start position:0% +example um people enclosed the the open + + + align:start position:0% +example um people enclosed the the open +porch of koues to make + + align:start position:0% +porch of koues to make + + + align:start position:0% +porch of koues to make +garages they replaced long linear + + align:start position:0% +garages they replaced long linear + + + align:start position:0% +garages they replaced long linear +windows by rectangular Windows of a much + + align:start position:0% +windows by rectangular Windows of a much + + + align:start position:0% +windows by rectangular Windows of a much +more uh oblong + + align:start position:0% +more uh oblong + + + align:start position:0% +more uh oblong +nature arguing that K's windows were not + + align:start position:0% +nature arguing that K's windows were not + + + align:start position:0% +nature arguing that K's windows were not +modern + + align:start position:0% + + + + align:start position:0% + +enough and so on and so on when kizzi + + align:start position:0% +enough and so on and so on when kizzi + + + align:start position:0% +enough and so on and so on when kizzi +was asked by Buon about these + + align:start position:0% +was asked by Buon about these + + + align:start position:0% +was asked by Buon about these +changes he said + + align:start position:0% + + + + align:start position:0% + +as if grammatically as possible life is + + align:start position:0% +as if grammatically as possible life is + + + align:start position:0% +as if grammatically as possible life is +more important than + + align:start position:0% + + + + align:start position:0% + +art but there was no con there was no + + align:start position:0% +art but there was no con there was no + + + align:start position:0% +art but there was no con there was no +indication that he expect Ed or made + + align:start position:0% +indication that he expect Ed or made + + + align:start position:0% +indication that he expect Ed or made +Provisions for changes to take + + align:start position:0% +Provisions for changes to take + + + align:start position:0% +Provisions for changes to take +place he was Central to + + align:start position:0% +place he was Central to + + + align:start position:0% +place he was Central to +modernism that time was captured within + + align:start position:0% +modernism that time was captured within + + + align:start position:0% +modernism that time was captured within +the space of the + + align:start position:0% +the space of the + + + align:start position:0% +the space of the +project he neither looked + + align:start position:0% +project he neither looked + + + align:start position:0% +project he neither looked +forward to changes that could be made + + align:start position:0% +forward to changes that could be made + + + align:start position:0% +forward to changes that could be made +nor did you look back to the possibility + + align:start position:0% +nor did you look back to the possibility + + + align:start position:0% +nor did you look back to the possibility +of history or memory affecting your work + + align:start position:0% +of history or memory affecting your work + + + align:start position:0% +of history or memory affecting your work +so modernism as I try to indicate on + + align:start position:0% +so modernism as I try to indicate on + + + align:start position:0% +so modernism as I try to indicate on +Tuesday was a kind of notion of fixed + + align:start position:0% +Tuesday was a kind of notion of fixed + + + align:start position:0% +Tuesday was a kind of notion of fixed +culture which operated with the in the + + align:start position:0% +culture which operated with the in the + + + align:start position:0% +culture which operated with the in the +production of + + align:start position:0% +production of + + + align:start position:0% +production of +objects which had no reference backwards + + align:start position:0% +objects which had no reference backwards + + + align:start position:0% +objects which had no reference backwards +of any + + align:start position:0% +of any + + + align:start position:0% +of any +Value Kia is a classic example the man + + align:start position:0% +Value Kia is a classic example the man + + + align:start position:0% +Value Kia is a classic example the man +who denies the 19th century + + align:start position:0% +who denies the 19th century + + + align:start position:0% +who denies the 19th century +Street + + align:start position:0% +Street + + + align:start position:0% +Street +um + + align:start position:0% +um + + + align:start position:0% +um +forever and then proceeds + + align:start position:0% +forever and then proceeds + + + align:start position:0% +forever and then proceeds +to make projects like this one in which + + align:start position:0% +to make projects like this one in which + + + align:start position:0% +to make projects like this one in which +the steel workers themselves find the + + align:start position:0% +the steel workers themselves find the + + + align:start position:0% +the steel workers themselves find the +capacity to change without the change + + align:start position:0% +capacity to change without the change + + + align:start position:0% +capacity to change without the change +being + + align:start position:0% +being + + + align:start position:0% +being +premeditated we're going to be looking + + align:start position:0% +premeditated we're going to be looking + + + align:start position:0% +premeditated we're going to be looking +today at the issue of looking + + align:start position:0% +today at the issue of looking + + + align:start position:0% +today at the issue of looking +forward and what predictable what + + align:start position:0% +forward and what predictable what + + + align:start position:0% +forward and what predictable what +unpredictability + + align:start position:0% +unpredictability + + + align:start position:0% +unpredictability +means I will make I will use the case of + + align:start position:0% +means I will make I will use the case of + + + align:start position:0% +means I will make I will use the case of +MIT on the second and third + + align:start position:0% + + + + align:start position:0% + +page you will see the plan of MIT from + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +from + + align:start position:0% +from + + + align:start position:0% +from + + align:start position:0% + + + align:start position:0% +1916 to + + align:start position:0% +1916 to + + + align:start position:0% +1916 to + + align:start position:0% + + + align:start position:0% +2004 I was discuss Maria + + align:start position:0% +2004 I was discuss Maria + + + align:start position:0% +2004 I was discuss Maria +Z marus thesis and what he + + align:start position:0% + + + + align:start position:0% + +found next two pages are from Rodrigo + + align:start position:0% +found next two pages are from Rodrigo + + + align:start position:0% +found next two pages are from Rodrigo +Perez D + + align:start position:0% +Perez D + + + align:start position:0% +Perez D +work arguing + + align:start position:0% +work arguing + + + align:start position:0% +work arguing +that systematic adding on to existing + + align:start position:0% +that systematic adding on to existing + + + align:start position:0% +that systematic adding on to existing +buildings is an opportunity for good + + align:start position:0% +buildings is an opportunity for good + + + align:start position:0% +buildings is an opportunity for good +change + + align:start position:0% + + + + align:start position:0% + +it's not at the top isn't + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +Rodrigo Perez de AR a + + align:start position:0% +Rodrigo Perez de AR a + + + align:start position:0% +Rodrigo Perez de AR a +rce he's from he's from Colombia do you + + align:start position:0% +rce he's from he's from Colombia do you + + + align:start position:0% +rce he's from he's from Colombia do you +know him + + align:start position:0% + + + + align:start position:0% + +not he's a quiet man + + align:start position:0% +not he's a quiet man + + + align:start position:0% +not he's a quiet man +who + + align:start position:0% +who + + + align:start position:0% +who +um uh draws very beautiful + + align:start position:0% +um uh draws very beautiful + + + align:start position:0% +um uh draws very beautiful +drawings the + + align:start position:0% +drawings the + + + align:start position:0% +drawings the +servant in the larger reading list for + + align:start position:0% +servant in the larger reading list for + + + align:start position:0% +servant in the larger reading list for +this class you'll find the reference + + align:start position:0% +this class you'll find the reference + + + align:start position:0% +this class you'll find the reference +it's it's published in architectural + + align:start position:0% +it's it's published in architectural + + + align:start position:0% +it's it's published in architectural +design and also in a little handbook by + + align:start position:0% +design and also in a little handbook by + + + align:start position:0% +design and also in a little handbook by +the architectural Association in + + align:start position:0% + + + + align:start position:0% + +London + + align:start position:0% + + + + align:start position:0% + +I will show some examples of his + + align:start position:0% +I will show some examples of his + + + align:start position:0% +I will show some examples of his +work + + align:start position:0% +work + + + align:start position:0% +work +um the next two pages + + align:start position:0% +um the next two pages + + + align:start position:0% +um the next two pages +are drawings by Louie khah and Allison + + align:start position:0% +are drawings by Louie khah and Allison + + + align:start position:0% +are drawings by Louie khah and Allison +and Peter Smithson of the team 10 + + align:start position:0% +and Peter Smithson of the team 10 + + + align:start position:0% +and Peter Smithson of the team 10 +group dealing with + + align:start position:0% + + + + align:start position:0% + +flows the next few pages are plans of + + align:start position:0% +flows the next few pages are plans of + + 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hands of a small group of + + align:start position:0% +cim was in the hands of a small group of + + + align:start position:0% +cim was in the hands of a small group of +Architects called team + + align:start position:0% +Architects called team + + + align:start position:0% +Architects called team +10 who put forward the + + align:start position:0% +10 who put forward the + + + align:start position:0% +10 who put forward the +possibility that time could be escaped + + align:start position:0% +possibility that time could be escaped + + + align:start position:0% +possibility that time could be escaped +from that's my words they didn't write + + align:start position:0% +from that's my words they didn't write + + + align:start position:0% +from that's my words they didn't write +it Allison pet smithson's team 10 + + align:start position:0% +it Allison pet smithson's team 10 + + + align:start position:0% +it Allison pet smithson's team 10 +primary is the doctrine of their + + align:start 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to ordain + + + align:start position:0% +that it's not within our power to ordain +the future he gives the + + align:start position:0% +the future he gives the + + + align:start position:0% +the future he gives the +example + + align:start position:0% +example + + + align:start position:0% +example +of the world's largest the world's large + + align:start position:0% +of the world's largest the world's large + + + align:start position:0% +of the world's largest the world's large +100 largest + + align:start position:0% +100 largest + + + align:start position:0% +100 largest +companies in the period from 1912 to + + align:start position:0% +companies in the period from 1912 to + + + align:start position:0% +companies in the period from 1912 to +1995 out of the 100 largest industrial + + align:start position:0% +1995 out of the 100 largest industrial + + + align:start position:0% +1995 out of the 100 largest industrial +companies in + + align:start position:0% +companies in + + + align:start position:0% +companies in +1912 how many have survived in 199 + + align:start position:0% +1912 how many have survived in 199 + + + align:start position:0% +1912 how many have survived in 199 + + align:start position:0% + + + + align:start position:0% + +gu there's a good book called The Living + + align:start position:0% + + + + align:start position:0% + +company + + align:start position:0% +company + + + align:start position:0% +company +stud company's over 200 years old to + + align:start position:0% +stud company's over 200 years old to + + + align:start position:0% +stud company's over 200 years old to +understand what would make them last + + align:start position:0% +understand what would make them last + + + align:start position:0% +understand what would make them last +over + + align:start position:0% +over + + + align:start position:0% +over +time well 48% of the companies which + + align:start position:0% +time well 48% of the companies which + + + align:start 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position:0% +so we don't teach history +properly we don't teach Urban history at + + align:start position:0% +properly we don't teach Urban history at + + + align:start position:0% +properly we don't teach Urban history at +all + + align:start position:0% +all + + + align:start position:0% +all +all I've complained about this for most + + align:start position:0% +all I've complained about this for most + + + align:start position:0% +all I've complained about this for most +of my career and seeing this is the last + + align:start position:0% +of my career and seeing this is the last + + + align:start position:0% +of my career and seeing this is the last +time I have to + + align:start position:0% + + + + align:start position:0% + +complain I I'll complain + + align:start position:0% +complain I I'll complain + + + align:start position:0% +complain I I'll complain +finally for for the + + align:start position:0% + + + + align:start position:0% + +record all right we'll talk about the + + 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you +have to you can also do excessive + + align:start position:0% +have to you can also do excessive + + + align:start position:0% +have to you can also do excessive +prediction I think I showed you a + + align:start position:0% +prediction I think I showed you a + + + align:start position:0% +prediction I think I showed you a +diagram of a South African mining town a + + align:start position:0% +diagram of a South African mining town a + + + align:start position:0% +diagram of a South African mining town a +classic case where the town was designed + + align:start position:0% +classic case where the town was designed + + + align:start position:0% +classic case where the town was designed +so that the Central Business could + + align:start position:0% +so that the Central Business could + + + align:start position:0% +so that the Central Business could +expand the expansion area around the + + align:start position:0% +expand the expansion area around the + + + align:start position:0% 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of to +expand ex leaving land for + + align:start position:0% +expand ex leaving land for + + + align:start position:0% +expand ex leaving land for +expansion is one of the ideas that we + + align:start position:0% +expansion is one of the ideas that we + + + align:start position:0% +expansion is one of the ideas that we +look at a bit more + + align:start position:0% + + + + align:start position:0% + +carefully you can leave open space for + + align:start position:0% +carefully you can leave open space for + + + align:start position:0% +carefully you can leave open space for +consumption as assuming a coarse grain + + align:start position:0% +consumption as assuming a coarse grain + + + align:start position:0% +consumption as assuming a coarse grain +in your + + align:start position:0% +in your + + + align:start position:0% +in your +town I will show you the example of the + + align:start position:0% +town I will show you the example of the + + + align:start position:0% +town I will show you the example of the +so so Olympics in + + align:start position:0% +so so Olympics in + + + align:start position:0% +so so Olympics in +1988 which built its Olympic Games on + + align:start position:0% +1988 which built its Olympic Games on + + + align:start position:0% +1988 which built its Olympic Games on +the basis + + align:start position:0% +the basis + + + align:start position:0% +the basis +of Fairly large open space + + align:start position:0% +of Fairly large open space + + + align:start position:0% +of Fairly large open space +system who knows the 1988 Olympic + + align:start position:0% +system who knows the 1988 Olympic + + + align:start position:0% +system who knows the 1988 Olympic +Games Were You There not at the game but + + align:start position:0% +Games Were You There not at the game but + + + align:start position:0% +Games Were You There not at the game but +I know the side you know the side yeah + + align:start position:0% +I know the side you know the side yeah + + + align:start position:0% +I know the side you know the side yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +it's a classic example of the + + align:start position:0% +it's a classic example of the + + + align:start position:0% +it's a classic example of the +cannibalization of easy access space + + align:start position:0% +cannibalization of easy access space + + + align:start position:0% +cannibalization of easy access space +open space is easy access it's cheap not + + align:start position:0% +open space is easy access it's cheap not + + + align:start position:0% +open space is easy access it's cheap not +cheap in the Public's mind but cheaps in + + align:start position:0% +cheap in the Public's mind but cheaps in + + + align:start position:0% +cheap in the Public's mind but cheaps in +the cheap in the promoter's + + align:start position:0% +the cheap in the promoter's + + + align:start position:0% +the cheap in the promoter's +mind and most of the facilities + + align:start position:0% +mind and most of the facilities + + + align:start position:0% +mind and most of the facilities +including the Olympic Village by cang Wu + + align:start position:0% +including the Olympic Village by cang Wu + + + align:start position:0% +including the Olympic Village by cang Wu +who lives here in + + align:start position:0% +who lives here in + + + align:start position:0% +who lives here in +Cambridge was built on this available + + align:start position:0% +Cambridge was built on this available + + + align:start position:0% +Cambridge was built on this available +land will come to Soul 88 later + + align:start position:0% +land will come to Soul 88 later + + + align:start position:0% +land will come to Soul 88 later +on I'm just running through some of + + align:start position:0% + + + + align:start position:0% + +these there infra infrastructure + + align:start position:0% +these there infra infrastructure + + + align:start position:0% +these there infra infrastructure +flexibility um when we designed the MIT + + align:start position:0% +flexibility um when we designed the MIT + + + align:start position:0% +flexibility um when we designed the MIT +brain and cognitive Sciences building we + + align:start position:0% +brain and cognitive Sciences building we + + + align:start position:0% +brain and cognitive Sciences building we +had to allow for the CX railroad to run + + align:start position:0% +had to allow for the CX railroad to run + + + align:start position:0% +had to allow for the CX railroad to run +underneath the + + align:start position:0% +underneath the + + + align:start position:0% +underneath the +building that meant uh an extraordinary + + align:start position:0% +building that meant uh an extraordinary + + + align:start position:0% +building that meant uh an extraordinary +difference in the kind of building which + + align:start position:0% +difference in the kind of building which + + + align:start position:0% +difference in the kind of building which +we could design + + align:start position:0% +we could design + + + align:start position:0% +we could design +but we calculated that if the + + align:start position:0% +but we calculated that if the + + + align:start position:0% +but we calculated that if the +Aires MIT owns the Aires over the CSX + + align:start position:0% +Aires MIT owns the Aires over the CSX + + + align:start position:0% +Aires MIT owns the Aires over the CSX +railroad about 22 ft or 15 M I'm not + + align:start position:0% +railroad about 22 ft or 15 M I'm not + + + align:start position:0% +railroad about 22 ft or 15 M I'm not +sure which I think it's 22 ft MIT can + + align:start position:0% +sure which I think it's 22 ft MIT can + + + align:start position:0% +sure which I think it's 22 ft MIT can +build 22 ft above the plane of the + + align:start position:0% +build 22 ft above the plane of the + + + align:start position:0% +build 22 ft above the plane of the +railroad we calculated when work working + + align:start position:0% +railroad we calculated when work working + + + align:start position:0% +railroad we calculated when work working +on this that if MIT exercised this + + align:start position:0% +on this that if MIT exercised this + + + align:start position:0% +on this that if MIT exercised this +option and built on the air maximum air + + align:start position:0% +option and built on the air maximum air + + + align:start position:0% +option and built on the air maximum air +rights that the well they they have the + + align:start position:0% +rights that the well they they have the + + + align:start position:0% +rights that the well they they have the +air rights the degree to which they can + + align:start position:0% +air rights the degree to which they can + + + align:start position:0% +air rights the degree to which they can +build vertically will have to be + + align:start position:0% +build vertically will have to be + + + align:start position:0% +build vertically will have to be +sanctioned by the city but we calculated + + align:start position:0% +sanctioned by the city but we calculated + + + align:start position:0% +sanctioned by the city but we calculated +that if MIT wish to expand its campus + + align:start position:0% +that if MIT wish to expand its campus + + + align:start position:0% +that if MIT wish to expand its campus +vertically over the + + align:start position:0% +vertically over the + + + align:start position:0% +vertically over the +airit or will the the the development + + align:start position:0% +airit or will the the the development + + + align:start position:0% +airit or will the the the development +would be worth billions of dollars in + + align:start position:0% +would be worth billions of dollars in + + + align:start position:0% +would be worth billions of dollars in +Cambridge terms of square + + align:start position:0% +Cambridge terms of square + + + align:start position:0% +Cambridge terms of square +footage so imagine the possibility of a + + align:start position:0% +footage so imagine the possibility of a + + + align:start position:0% +footage so imagine the possibility of a +future in which MIT could + + align:start position:0% +future in which MIT could + + + align:start position:0% +future in which MIT could +build above a railway + + align:start position:0% + + + + align:start position:0% + +line fact is that we only Built to the + + align:start position:0% +line fact is that we only Built to the + + + align:start position:0% +line fact is that we only Built to the +height at Cambridge alars in our + + align:start position:0% +height at Cambridge alars in our + + + align:start position:0% +height at Cambridge alars in our +building which was large enough for our + + align:start position:0% +building which was large enough for our + + + align:start position:0% +building which was large enough for our +program + + align:start position:0% + + + + align:start position:0% + +but this friction caused by a movement + + align:start position:0% +but this friction caused by a movement + + + align:start position:0% +but this friction caused by a movement +system Kia's proposition of building + + align:start position:0% +system Kia's proposition of building + + + align:start position:0% +system Kia's proposition of building +under the freeways in + + align:start position:0% +under the freeways in + + + align:start position:0% +under the freeways in +algers is not feasible + + align:start position:0% +algers is not feasible + + + align:start position:0% +algers is not feasible +anymore the noise and pollution caused + + align:start position:0% +anymore the noise and pollution caused + + + align:start position:0% +anymore the noise and pollution caused +by the automobiles would make it + + align:start position:0% +by the automobiles would make it + + + align:start position:0% +by the automobiles would make it +impossible to virtually possible to + + align:start position:0% +impossible to virtually possible to + + + align:start position:0% +impossible to virtually possible to +build under + + align:start position:0% +build under + + + align:start position:0% +build under +freeways one of the dramatic Futures in + + align:start position:0% +freeways one of the dramatic Futures in + + + align:start position:0% +freeways one of the dramatic Futures in +the next few 50 years is going to be to + + align:start position:0% +the next few 50 years is going to be to + + + align:start position:0% +the next few 50 years is going to be to +how to capture the space under elevated + + align:start position:0% +how to capture the space under elevated + + + align:start position:0% +how to capture the space under elevated +freeways all over the world they + + align:start position:0% +freeways all over the world they + + + align:start position:0% +freeways all over the world they +elevated con to considerable + + align:start position:0% +elevated con to considerable + + + align:start position:0% +elevated con to considerable +height because you have to be able to + + align:start position:0% +height because you have to be able to + + + align:start position:0% +height because you have to be able to +pass through with a truck which means + + align:start position:0% +pass through with a truck which means + + + align:start position:0% +pass through with a truck which means +that you have to have ramps which at 1 + + align:start position:0% +that you have to have ramps which at 1 + + + align:start position:0% +that you have to have ramps which at 1 +in 10 or 1 in five depending how steep + + align:start position:0% +in 10 or 1 in five depending how steep + + + align:start position:0% +in 10 or 1 in five depending how steep +you are you can take up a large amount + + align:start position:0% +you are you can take up a large amount + + + align:start position:0% +you are you can take up a large amount +of space + + align:start position:0% +of space + + + align:start position:0% +of space +so I haven't seen a proposition in + + align:start position:0% +so I haven't seen a proposition in + + + align:start position:0% +so I haven't seen a proposition in +recent times anywhere in the world for + + align:start position:0% +recent times anywhere in the world for + + + align:start position:0% +recent times anywhere in the world for +capturing the space under a freeway in + + align:start position:0% +capturing the space under a freeway in + + + align:start position:0% +capturing the space under a freeway in +a in a positive sense we have one SM Mar + + align:start position:0% +a in a positive sense we have one SM Mar + + + align:start position:0% +a in a positive sense we have one SM Mar +student project thesis which you'll see + + align:start position:0% +student project thesis which you'll see + + + align:start position:0% +student project thesis which you'll see +in 3 weeks time which tries to do this 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align:start position:0% +and the development below that +plane + + align:start position:0% +plane + + + align:start position:0% +plane +even penetrating into the + + align:start position:0% +even penetrating into the + + + align:start position:0% +even penetrating into the +ground options which utopianist have + + align:start position:0% +ground options which utopianist have + + + align:start position:0% +ground options which utopianist have +examined and wondered about + + align:start position:0% +examined and wondered about + + + align:start position:0% +examined and wondered about +uh so we have to include them on our + + align:start position:0% + + + + align:start position:0% + +list lastly is the question of + + align:start position:0% +list lastly is the question of + + + align:start position:0% +list lastly is the question of +geometry and most of the rest of my talk + + align:start position:0% +geometry and most of the rest of my talk + + + align:start position:0% +geometry and most of the rest of my talk +is going to deal with a with people + + align:start position:0% +is going to deal with a with people + + + align:start position:0% +is going to deal with a with people +who've used the idea of geometry to + + align:start position:0% +who've used the idea of geometry to + + + align:start position:0% +who've used the idea of geometry to +allow for future + + align:start position:0% + + + + align:start position:0% + +change + + align:start position:0% +change + + + align:start position:0% +change +okay one of the people who argued for + + align:start position:0% +okay one of the people who argued for + + + align:start position:0% +okay one of the people who argued for +the impact of geometry is Maria Zero's + + align:start position:0% +the impact of geometry is Maria Zero's + + + align:start position:0% +the impact of geometry is Maria Zero's +thesis Maria was in this + + align:start position:0% +thesis Maria was in this + + + align:start position:0% +thesis Maria was in this +class and became interested in the idea + + align:start position:0% +class and became interested in the idea + + + align:start position:0% +class and became interested in the idea +of + + align:start position:0% +of + + + align:start position:0% +of +change she wanted to study a city W and + + align:start position:0% +change she wanted to study a city W and + + + align:start position:0% +change she wanted to study a city W and +how make some speculation about how + + align:start position:0% +how make some speculation about how + + + align:start position:0% +how make some speculation about how +Urban transport transformation took + + align:start position:0% +Urban transport transformation took + + + align:start position:0% +Urban transport transformation took +place + + align:start position:0% + + + + align:start position:0% + +she decided after being + + align:start position:0% +she decided after being + + + align:start position:0% +she decided after being +forced to 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align:start position:0% +time is it because we try to do too + + + align:start position:0% +time is it because we try to do too +much but if you don't do too much who + + align:start position:0% +much but if you don't do too much who + + + align:start position:0% +much but if you don't do too much who +says what is + + align:start position:0% +says what is + + + align:start position:0% +says what is +enough + + align:start position:0% +enough + + + align:start position:0% +enough +should one take one project like this + + align:start position:0% +should one take one project like this + + + align:start position:0% +should one take one project like this +and spend a semester studying it in + + align:start position:0% +and spend a semester studying it in + + + align:start position:0% +and spend a semester studying it in +detail would you gain more from doing + + align:start position:0% +detail would you gain more from doing + + + align:start position:0% +detail would you gain more from 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kind of + + align:start position:0% +that there was a kind of + + + align:start position:0% +that there was a kind of +DNA in the + + align:start position:0% + + + + align:start position:0% + +system not a very profound DNA but a + + align:start position:0% +system not a very profound DNA but a + + + align:start position:0% +system not a very profound DNA but a +very simple DNA which allowed a mighty + + align:start position:0% +very simple DNA which allowed a mighty + + + align:start position:0% +very simple DNA which allowed a mighty +to grow until + + align:start position:0% + + + + align:start position:0% + +204 on its own + + align:start position:0% +204 on its own + + + align:start position:0% +204 on its own +land + + align:start position:0% + + + + align:start position:0% + +our building the brain and cognitive + + align:start position:0% +our building the brain and cognitive + + + align:start position:0% +our building the brain and cognitive +Center is on the other side of Asa + + align:start position:0% +Center is on the other side of Asa + + + align:start position:0% +Center is on the other side of Asa +Street it was the first time + + align:start position:0% +Street it was the first time + + + align:start position:0% +Street it was the first time +a a building not the first time but one + + align:start position:0% +a a building not the first time but one + + + align:start position:0% +a a building not the first time but one +of the first times a major building was + + align:start position:0% +of the first times a major building was + + + align:start position:0% +of the first times a major building was +built outside of the limited + + align:start position:0% +built outside of the limited + + + align:start position:0% +built outside of the limited +campus we proposed a connection an + + align:start position:0% +campus we proposed a connection an + + + align:start position:0% +campus we proposed a connection an +aerial connection from building whatever + + align:start position:0% +aerial connection from building whatever + + + align:start position:0% +aerial connection from building whatever +it is across ver Street to + + align:start position:0% +it is across ver Street to + + + align:start position:0% +it is across ver Street to +a to a place on our SEC the second floor + + align:start position:0% +a to a place on our SEC the second floor + + + align:start position:0% +a to a place on our SEC the second floor +of the brain and cogn centers MIT + + align:start position:0% +of the brain and cogn centers MIT + + + align:start position:0% +of the brain and cogn centers MIT +wouldn't build it we tried very hard to + + align:start position:0% +wouldn't build it we tried very hard to + + + align:start position:0% +wouldn't build it we tried very hard to +get it built in fact the German engineer + + align:start position:0% +get it built in fact the German engineer + + + align:start position:0% +get it built in fact the German engineer +Jo SCH who worked on the Freedom Tower + + align:start position:0% +Jo SCH who worked on the Freedom Tower + + + align:start position:0% +Jo SCH who worked on the Freedom Tower +in New York is probably the best + + align:start position:0% +in New York is probably the best + + + align:start position:0% +in New York is probably the best +structural engineer in the world + + align:start position:0% +structural engineer in the world + + + align:start position:0% +structural engineer in the world +designed the connector but it + + align:start position:0% +designed the connector but it + + + align:start position:0% +designed the connector but it +didn't a might now faces an expansive + + align:start position:0% +didn't a might now faces an expansive + + + align:start position:0% +didn't a might now faces an expansive +possibility which is not as + + align:start position:0% +possibility which is not as + + + align:start position:0% +possibility which is not as +simple as expanding on your own land has + + align:start position:0% +simple as expanding on your own land has + + + align:start position:0% +simple as expanding on your own land has +to deal with Urban infrastructure of a + + align:start position:0% +to deal with Urban infrastructure of a + + + align:start position:0% +to deal with Urban infrastructure of a +much more complex + + align:start position:0% + + + + align:start position:0% + +nature another use of + + align:start position:0% +nature another use of + + + align:start position:0% +nature another use of +geometry which we mentioned before is in + + align:start position:0% +geometry which we mentioned before is in + + + align:start position:0% +geometry which we mentioned before is in +the L and Dav was planned for Milton ke + + align:start position:0% +the L and Dav was planned for Milton ke + + + align:start position:0% +the L and Dav was planned for Milton ke +in London one of the mark + + align:start position:0% +in London one of the mark + + + align:start 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too + + align:start position:0% +enclosed grid space would not not be too + + + align:start position:0% +enclosed grid space would not not be too +large and require great separated inter + + align:start position:0% + + + + align:start position:0% + +interaction some other + + align:start position:0% + + + + align:start position:0% + +ideas the old premise of Milton K's plan + + align:start position:0% +ideas the old premise of Milton K's plan + + + align:start position:0% +ideas the old premise of Milton K's plan +is summarized as follows the central aim + + align:start position:0% +is summarized as follows the central aim + + + align:start position:0% +is summarized as follows the central aim +of the plan is to arrange these + + align:start position:0% +of the plan is to arrange these + + + align:start position:0% +of the plan is to arrange these +necessary fixed elements transport + + align:start position:0% +necessary fixed elements transport + + + align:start position:0% +necessary fixed elements transport +drainage water supply in a new city so + + align:start position:0% +drainage water supply in a new city so + + + align:start position:0% +drainage water supply in a new city so +as to allow the Great possible scope for + + align:start position:0% +as to allow the Great possible scope for + + + align:start position:0% +as to allow the Great possible scope for +freedom and + + align:start position:0% + + + + align:start position:0% + +change they've it has been planned as + + align:start position:0% +change they've it has been planned as + + + align:start position:0% +change they've it has been planned as +far as possible to allow wide varieties + + align:start position:0% +far as possible to allow wide varieties + + + align:start position:0% +far as possible to allow wide varieties +in patterns of life and the greatest + + align:start position:0% +in patterns of life and the greatest + + + align:start position:0% +in patterns of life and the greatest +possible choice for the + + align:start position:0% +possible choice for the + + + align:start position:0% +possible choice for the +future there are two things in the + + align:start position:0% +future there are two things in the + + + align:start position:0% +future there are two things in the +geometry of the well in the application + + align:start position:0% +geometry of the well in the application + + + align:start position:0% +geometry of the well in the application +of the + + align:start position:0% +of the + + + align:start position:0% +of the +geometry number one is the idea of as I + + align:start position:0% +geometry number one is the idea of as I + + + align:start position:0% +geometry number one is the idea of as I +Dre Drew on the Blackboard of + + align:start position:0% +Dre Drew on the Blackboard of + + + align:start position:0% +Dre Drew on the Blackboard of +recognizing the possibility of a space + + align:start position:0% +recognizing the possibility of a space + + + align:start position:0% +recognizing the possibility of a space +frame system space frame system in + + align:start position:0% +frame system space frame system in + + + align:start position:0% +frame system space frame system in +architecture is a system which spans + + align:start position:0% +architecture is a system which spans + + + align:start position:0% +architecture is a system which spans +distance and allows you to put points on + + align:start position:0% +distance and allows you to put points on + + + align:start position:0% +distance and allows you to put points on +the low load system at any point as + + align:start position:0% +the low load system at any point as + + + align:start position:0% +the low load system at any point as +opposed to point and beam + + align:start position:0% +opposed to point and beam + + + align:start position:0% +opposed to point and beam +system where you can only load the + + align:start position:0% +system where you can only load the + + + align:start position:0% +system where you can only load the +system where there is a column beneath + + align:start position:0% +system where there is a column beneath + + + align:start position:0% +system where there is a column beneath +your your point + + align:start position:0% +your your point + + + align:start position:0% +your your point +so it's a kind of pointless system or + + align:start position:0% +so it's a kind of pointless system or + + + align:start position:0% +so it's a kind of pointless system or +freedom of pointing which allows almost + + align:start position:0% +freedom of pointing which allows almost + + + align:start position:0% +freedom of pointing which allows almost +any kind of change to exist the notion + + align:start position:0% +any kind of change to exist the notion + + + align:start position:0% +any kind of change to exist the notion +of deciding what the maximum amount that + + align:start position:0% +of deciding what the maximum amount that + + + align:start position:0% +of deciding what the maximum amount that +you can allow before the system cripples + + align:start position:0% +you can allow before the system cripples + + + align:start position:0% +you can allow before the system cripples +itself is interesting you have to + + align:start position:0% + + + + align:start position:0% + +use mathematical prediction systems like + + align:start position:0% +use mathematical prediction systems like + + + align:start position:0% +use mathematical prediction systems like +the poron distribution who knows what + + align:start position:0% +the poron distribution who knows what + + + align:start position:0% +the poron distribution who knows what +the for on distribution + + align:start position:0% +the for on distribution + + + align:start position:0% +the for on distribution +is you should + + align:start position:0% + + + + align:start position:0% + +know if you're going to design a + + align:start position:0% +know if you're going to design a + + + align:start position:0% +know if you're going to design a +University campus how do you decide or + + align:start position:0% +University campus how do you decide or + + + align:start position:0% +University campus how do you decide or +School room how do you decide on the + + align:start position:0% +School room how do you decide on the + + + align:start position:0% +School room how do you decide on the +size of the distribution of the sizes of + + align:start position:0% + + + + align:start position:0% + +classrooms you + + align:start position:0% +classrooms you + + + align:start position:0% +classrooms you +Architects you're in advanced standing + + align:start position:0% +Architects you're in advanced standing + + + align:start position:0% +Architects you're in advanced standing +at MIT you're doing doctorates you're + + align:start position:0% +at MIT you're doing doctorates you're + + + align:start position:0% +at MIT you're doing doctorates you're +doing kinds of advanced + + align:start position:0% +doing kinds of advanced + + + align:start position:0% +doing kinds of advanced +degrees and if I ask you the simple + + align:start position:0% +degrees and if I ask you the simple + + + align:start position:0% +degrees and if I ask you the simple +proposition that if you had to walk out + + align:start position:0% +proposition that if you had to walk out + + + align:start position:0% +proposition that if you had to walk out +of a and you had and you were in Burma + + align:start position:0% +of a and you had and you were in Burma + + + align:start position:0% +of a and you had and you were in Burma +somewhere and they were decided to build + + align:start position:0% +somewhere and they were decided to build + + + align:start position:0% +somewhere and they were decided to build +a new University how would you decide on + + align:start position:0% +a new University how would you decide on + + + align:start position:0% +a new University how would you decide on +its + + align:start position:0% +its + + + align:start position:0% +its +program without knowing the for on + + align:start position:0% +program without knowing the for on + + + align:start position:0% +program without knowing the for on +distribution University of ma the + + align:start position:0% +distribution University of ma the + + + align:start position:0% +distribution University of ma the +Department of Mathematics at Cambridge + + align:start position:0% +Department of Mathematics at Cambridge + + + align:start position:0% +Department of Mathematics at Cambridge +University a new building is designed on + + align:start position:0% +University a new building is designed on + + + align:start position:0% +University a new building is designed on +the basis of the poron distribution + + align:start position:0% +the basis of the poron distribution + + + align:start position:0% +the basis of the poron distribution +it allocates probability of sizes given + + align:start position:0% +it allocates probability of sizes given + + + align:start position:0% +it allocates probability of sizes given +certain average + + align:start position:0% +certain average + + + align:start position:0% +certain average +rates I'm not trying to be clever I'm + + align:start position:0% +rates I'm not trying to be clever I'm + + + align:start position:0% +rates I'm not trying to be clever I'm +just trying to say + + align:start position:0% +just trying to say + + + align:start position:0% +just trying to say +that there + + align:start position:0% +that there + + + align:start position:0% +that there +are statistical measures which give one + + align:start position:0% +are statistical measures which give one + + + align:start position:0% +are statistical measures which give one +a better prediction about the + + align:start position:0% + + + + align:start position:0% + +future one of the best subject I ever + + align:start position:0% +future one of the best subject I ever + + + align:start position:0% +future one of the best subject I ever +studied in graduate school was + + align:start position:0% +studied in graduate school was + + + align:start position:0% +studied in graduate school was +statistics I hated it but it made me + + align:start position:0% +statistics I hated it but it made me + + + align:start position:0% +statistics I hated it but it made me +aware of the fact that you can generate + + align:start position:0% +aware of the fact that you can generate + + + align:start position:0% +aware of the fact that you can generate +knowledge through sampling systems of + + align:start position:0% +knowledge through sampling systems of + + + align:start position:0% +knowledge through sampling systems of +great + + align:start position:0% + + + + align:start position:0% + +capacity I was staggered when my + + align:start position:0% +capacity I was staggered when my + + + align:start position:0% +capacity I was staggered when my +professor said the only reason we have + + align:start position:0% +professor said the only reason we have + + + align:start position:0% +professor said the only reason we have +live matches is because we know + + align:start position:0% +live matches is because we know + + + align:start position:0% +live matches is because we know +statistically how many matches + + align:start position:0% +statistically how many matches + + + align:start position:0% +statistically how many matches +fail and we can predict the production + + align:start position:0% +fail and we can predict the production + + + align:start position:0% +fail and we can predict the production +of boxes and matches without any of them + + align:start position:0% +of boxes and matches without any of them + + + align:start position:0% +of boxes and matches without any of them +failing + + align:start position:0% +failing + + + align:start position:0% +failing +or 99% + + align:start position:0% +or 99% + + + align:start position:0% +or 99% +succeeding + + align:start position:0% +succeeding + + + align:start position:0% +succeeding +staggered staggering but a simple + + align:start position:0% +staggered staggering but a simple + + + align:start position:0% +staggered staggering but a simple +observation the pon distribution is one + + align:start position:0% +observation the pon distribution is one + + + align:start position:0% +observation the pon distribution is one +of + + align:start position:0% + + + + align:start position:0% + +the features of + + align:start position:0% +the features of + + + align:start position:0% +the features of +uh so this the second feature of Milton + + align:start position:0% +uh so this the second feature of Milton + + + align:start position:0% +uh so this the second feature of Milton +kanes in trying + + align:start position:0% +kanes in trying + + + align:start position:0% +kanes in trying +to project the possibility of first of + + align:start position:0% +to project the possibility of first of + + + align:start position:0% +to project the possibility of first of +all diversity and secondly of change is + + align:start position:0% +all diversity and secondly of change is + + + align:start position:0% +all diversity and secondly of change is +to introduce zoning systems based on + + align:start position:0% +to introduce zoning systems based on + + + align:start position:0% +to introduce zoning systems based on +performance + + align:start position:0% + + + + align:start position:0% + +Dimensions the reason why German zoning + + align:start position:0% +Dimensions the reason why German zoning + + + align:start position:0% +Dimensions the reason why German zoning +started out was because of the + + align:start position:0% +started out was because of the + + + align:start position:0% +started out was because of the +industrial city causing noise and dirt + + align:start position:0% +industrial city causing noise and dirt + + + align:start position:0% +industrial city causing noise and dirt +and fumes and traffic as opposed to the + + align:start position:0% +and fumes and traffic as opposed to the + + + align:start position:0% +and fumes and traffic as opposed to the +quiet Notions that required in a + + align:start position:0% +quiet Notions that required in a + + + align:start position:0% +quiet Notions that required in a +residential + + align:start position:0% +residential + + + align:start position:0% +residential +area if + + align:start position:0% +area if + + + align:start position:0% +area if +today uh a high-tech company produces no + + align:start position:0% +today uh a high-tech company produces no + + + align:start position:0% +today uh a high-tech company produces no +noise no smoke no sound can it not be + + align:start position:0% +noise no smoke no sound can it not be + + + align:start position:0% +noise no smoke no sound can it not be +adjacent to a residential + + align:start position:0% + + + + align:start position:0% + +building of course I don't know how this + + align:start position:0% +building of course I don't know how this + + + align:start position:0% +building of course I don't know how this +has worked in Wilton KES if I buy a + + align:start position:0% +has worked in Wilton KES if I buy a + + + align:start position:0% +has worked in Wilton KES if I buy a +piece of land and I make a wonderful + + align:start position:0% +piece of land and I make a wonderful + + + align:start position:0% +piece of land and I make a wonderful +garden next to it it has + + align:start position:0% +garden next to it it has + + + align:start position:0% +garden next to it it has +value if the city decides to build a + + align:start position:0% +value if the city decides to build a + + + align:start position:0% +value if the city decides to build a +factory next to it I lose + + align:start position:0% +factory next to it I lose + + + align:start position:0% +factory next to it I lose +value how do you count for that change + + align:start position:0% +value how do you count for that change + + + align:start position:0% +value how do you count for that change +do you repay + + align:start position:0% +do you repay + + + align:start position:0% +do you repay +me I take you to court and say I have + + align:start position:0% +me I take you to court and say I have + + + align:start position:0% +me I take you to court and say I have +rights they say you don't have rights to + + align:start position:0% +rights they say you don't have rights to + + + align:start position:0% +rights they say you don't have rights to +predict to confiscate the rights of of + + align:start position:0% +predict to confiscate the rights of of + + + align:start position:0% +predict to confiscate the rights of of +development so around + + align:start position:0% +development so around + + + align:start position:0% +development so around +you it's a fundamental problem if you + + align:start position:0% +you it's a fundamental problem if you + + + align:start position:0% +you it's a fundamental problem if you +wish to designed for + + align:start position:0% +wish to designed for + + + align:start position:0% +wish to designed for +diversity you can of course write rules + + align:start position:0% +diversity you can of course write rules + + + align:start position:0% +diversity you can of course write rules +saying that a factory will not be within + + align:start position:0% +saying that a factory will not be within + + + align:start position:0% +saying that a factory will not be within + + align:start position:0% + + + align:start position:0% +ft but performance Dimensions measure + + align:start position:0% +ft but performance Dimensions measure + + + align:start position:0% +ft but performance Dimensions measure +sound + + align:start position:0% +sound + + + align:start position:0% +sound +noise frequency of + + align:start position:0% +noise frequency of + + + align:start position:0% +noise frequency of +traffic if trucks start working as they + + align:start position:0% +traffic if trucks start working as they + + + align:start position:0% +traffic if trucks start working as they +do in New York at 5:00 in the morning + + align:start position:0% +do in New York at 5:00 in the morning + + + align:start position:0% +do in New York at 5:00 in the morning +and I want to sleep what right do I have + + align:start position:0% +and I want to sleep what right do I have + + + align:start position:0% +and I want to sleep what right do I have +to stop the trucks from off loing at + + align:start position:0% +to stop the trucks from off loing at + + + align:start position:0% +to stop the trucks from off loing at +5:00 in the + + align:start position:0% + + + + align:start position:0% + +morning these are tough + + align:start position:0% +morning these are tough + + + align:start position:0% +morning these are tough +questions and + + align:start position:0% +questions and + + + align:start position:0% +questions and +flexibility simply runs up against some + + align:start position:0% +flexibility simply runs up against some + + + align:start position:0% +flexibility simply runs up against some +of these questions in a very real sense + + align:start position:0% +of these questions in a very real sense + + + align:start position:0% +of these questions in a very real sense +it be interesting to check I need to + + align:start position:0% +it be interesting to check I need to + + + align:start position:0% +it be interesting to check I need to +talk + + align:start position:0% +talk + + + align:start position:0% +talk +to John Deano is one of the designers of + + align:start position:0% +to John Deano is one of the designers of + + + align:start position:0% +to John Deano is one of the designers of +wion King about how this has been + + align:start position:0% +wion King about how this has been + + + align:start position:0% +wion King about how this has been +handled to Rodrigo Perez D who argues in + + align:start position:0% +handled to Rodrigo Perez D who argues in + + + align:start position:0% +handled to Rodrigo Perez D who argues in +favor of keeping existing stock and + + align:start position:0% +favor of keeping existing stock and + + + align:start position:0% +favor of keeping existing stock and +building an architecture of + + align:start position:0% +building an architecture of + + + align:start position:0% +building an architecture of +addition he says + + align:start position:0% +addition he says + + + align:start position:0% +addition he says +urbanistic it has three + + align:start position:0% + + + + align:start position:0% + +advantages by being a gradual organist + + align:start position:0% +advantages by being a gradual organist + + + align:start position:0% +advantages by being a gradual organist +organized incorporation of Parts into an + + align:start position:0% +organized incorporation 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humanities and + + align:start position:0% +of mathematics School of humanities and + + + align:start position:0% +of mathematics School of humanities and +so + + align:start position:0% +so + + + align:start position:0% +so +on by the University of Lancaster in + + align:start position:0% +on by the University of Lancaster in + + + align:start position:0% +on by the University of Lancaster in +1964 attention starts being paid to the + + align:start position:0% +1964 attention starts being paid to the + + + align:start position:0% +1964 attention starts being paid to the +connecting of + + align:start position:0% +connecting of + + + align:start position:0% +connecting of +places and the system is one in which + + align:start position:0% +places and the system is one in which + + + align:start position:0% +places and the system is one in which +modulus space is connected in a in a + + align:start position:0% +modulus space is connected in a in a + + + align:start position:0% +modulus space is connected in a in a +complex Network + + align:start position:0% + + + + align:start position:0% + +number four the University of East + + align:start position:0% +number four the University of East + + + align:start position:0% +number four the University of East +Anglia in 1961 the plan is now a solid + + align:start position:0% +Anglia in 1961 the plan is now a solid + + + align:start position:0% +Anglia in 1961 the plan is now a solid +linear + + align:start position:0% +linear + + + align:start position:0% +linear +configuration with three with small + + align:start position:0% +configuration with three with small + + + align:start position:0% +configuration with three with small +outgrowths but the whole system is very + + align:start position:0% +outgrowths but the whole system is very + + + align:start position:0% +outgrowths but the whole system is very +much based on a + + align:start position:0% +much based on a + + + align:start position:0% +much based on a 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articulate the + + align:start position:0% +project starts trying to articulate the + + + align:start position:0% +project starts trying to articulate the +linearity by having a Central Public + + align:start position:0% +linearity by having a Central Public + + + align:start position:0% +linearity by having a Central Public +spine much like the main Corridor at + + align:start position:0% +spine much like the main Corridor at + + + align:start position:0% +spine much like the main Corridor at +MIT and + + align:start position:0% +MIT and + + + align:start position:0% +MIT and +outgrowth from it depending on the need + + align:start position:0% +outgrowth from it depending on the need + + + align:start position:0% +outgrowth from it depending on the need +to be close to the public versus + + align:start position:0% +to be close to the public versus + + + align:start position:0% +to be close to the public versus +uh versus Space which requires + + align:start position:0% +uh versus 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position:0% +for research scientist who need + + + align:start position:0% +for research scientist who need +specialized heating specialized air + + align:start position:0% +specialized heating specialized air + + + align:start position:0% +specialized heating specialized air +specialized steam specialized + + align:start position:0% +specialized steam specialized + + + align:start position:0% +specialized steam specialized +power if I produce all of this for + + align:start position:0% +power if I produce all of this for + + + align:start position:0% +power if I produce all of this for +everybody we can + + align:start position:0% +everybody we can + + + align:start position:0% +everybody we can +change with maximum + + align:start position:0% + + + + align:start position:0% + +flexibility do you understand the + + align:start position:0% +flexibility do you understand the + + + align:start position:0% +flexibility do you understand the +idea this is the ultimate measure + + 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align:start position:0% +right through the middle of the campus + + + align:start position:0% +right through the middle of the campus +with a train with a crane on it and it + + align:start position:0% +with a train with a crane on it and it + + + align:start position:0% +with a train with a crane on it and it +kept on moving the parts modules all + + align:start position:0% +kept on moving the parts modules all + + + align:start position:0% +kept on moving the parts modules all +over the place so if I if my department + + align:start position:0% +over the place so if I if my department + + + align:start position:0% +over the place so if I if my department +grew some modul could be added to the + + align:start position:0% +grew some modul could be added to the + + + align:start position:0% +grew some modul could be added to the +top of our existing + + align:start position:0% +top of our existing + + + align:start position:0% +top of our existing +Department if if we fired off of the + 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align:start position:0% +to explain where you should +be or where you're going to + + align:start position:0% + + + + align:start position:0% + +be MIT Central Corridor despite the + + align:start position:0% +be MIT Central Corridor despite the + + + align:start position:0% +be MIT Central Corridor despite the +changes has + + align:start position:0% +changes has + + + align:start position:0% +changes has +remained in it has a low rate of + + align:start position:0% +remained in it has a low rate of + + + align:start position:0% +remained in it has a low rate of +change it should have changed much more + + align:start position:0% +change it should have changed much more + + + align:start position:0% +change it should have changed much more +than it has but it's become embedded + + align:start position:0% +than it has but it's become embedded + + + align:start position:0% +than it has but it's become embedded +into the system so that whilst almost + + align:start position:0% +into the system so that whilst almost + + + align:start position:0% +into the system so that whilst almost +every other space at MIT has undergone + + align:start position:0% +every other space at MIT has undergone + + + align:start position:0% +every other space at MIT has undergone +change it hasn't it has the same old + + align:start position:0% +change it hasn't it has the same old + + + align:start position:0% +change it hasn't it has the same old +dull + + align:start position:0% +dull + + + align:start position:0% +dull +administrative instead of building a + + align:start position:0% +administrative instead of building a + + + align:start position:0% +administrative instead of building a +cafeteria across the street and it + + align:start position:0% +cafeteria across the street and it + + + align:start position:0% +cafeteria across the street and it +should have jettisoned its + + align:start position:0% +should have jettisoned its + + + align:start position:0% +should have jettisoned its +administrative facilities and used this + + align:start position:0% +administrative facilities and used this + + + align:start position:0% +administrative facilities and used this +major Corridor as a place for real + + align:start position:0% +major Corridor as a place for real + + + align:start position:0% +major Corridor as a place for real +public for exhibitions for eating for + + align:start position:0% +public for exhibitions for eating for + + + align:start position:0% +public for exhibitions for eating for +people coming together he + + align:start position:0% + + + + align:start position:0% + +didn't he lacked the intelligence or + + align:start position:0% +didn't he lacked the intelligence or + + + align:start position:0% +didn't he lacked the intelligence or +the but so excessive flexibility is very + + align:start position:0% +the but so excessive flexibility is very + + + align:start position:0% +the but so excessive flexibility is very +costly one of the reasons you can't do + + align:start position:0% +costly one of the reasons you can't do + + + align:start position:0% +costly one of the reasons you can't do +Advanced science in the old part of MIT + + align:start position:0% +Advanced science in the old part of MIT + + + align:start position:0% +Advanced science in the old part of MIT +is because the is a lack the + + align:start position:0% +is because the is a lack the + + + align:start position:0% +is because the is a lack the +infrastructure is too + + align:start position:0% + + + + align:start position:0% + +weak the sixth FL of our + + align:start position:0% + + + + align:start position:0% + +building our building + + align:start position:0% +building our building + + + align:start position:0% +building our building +has six + + align:start position:0% +has six + + + align:start position:0% +has six +floors well + + align:start position:0% +floors well + + + align:start position:0% +floors well +I'm the sixth floor is for animals + + align:start position:0% +I'm the sixth floor is for animals + + + align:start position:0% +I'm the sixth floor is for animals +all of animals are generally in + + align:start position:0% +all of animals are generally in + + + align:start position:0% +all of animals are generally in +basement one of the future for building + + align:start position:0% +basement one of the future for building + + + align:start position:0% +basement one of the future for building +University Research facilities given + + align:start position:0% +University Research facilities given + + + align:start position:0% +University Research facilities given +climate + + align:start position:0% +climate + + + align:start position:0% +climate +change in New York un New York + + align:start position:0% +change in New York un New York + + + align:start position:0% +change in New York un New York +University the animal Laboratories in + + align:start position:0% +University the animal Laboratories in + + + align:start position:0% +University the animal Laboratories in +the basement W + + align:start position:0% +the basement W + + + align:start position:0% +the basement W +flattered all the research was + + align:start position:0% +flattered all the research was + + + align:start position:0% +flattered all the research was +lost we put our up in the sky for no + + align:start position:0% +lost we put our up in the sky for no + + + align:start position:0% +lost we put our up in the sky for no +clear + + align:start position:0% +clear + + + align:start position:0% +clear +reasons we thought the animals would be + + align:start position:0% +reasons we thought the animals would be + + + align:start position:0% +reasons we thought the animals would be +better off up in the air then down in + + align:start position:0% +better off up in the air then down in + + + align:start position:0% +better off up in the air then down in +the basement and nobody + + align:start position:0% +the basement and nobody + + + align:start position:0% +the basement and nobody +disagreed on top of that floor is a + + align:start position:0% +disagreed on top of that floor is a + + + align:start position:0% +disagreed on top of that floor is a +floor of + + align:start position:0% +floor of + + + align:start position:0% +floor of +machines machines which look like + + align:start position:0% +machines machines which look like + + + align:start position:0% +machines machines which look like +airplane systems because the building + + align:start position:0% +airplane systems because the building + + + align:start position:0% +airplane systems because the building +needs to be is + + align:start position:0% +needs to be is + + + align:start position:0% +needs to be is +a is a laboratory + + align:start position:0% +a is a laboratory + + + align:start position:0% +a is a laboratory +which has + + align:start position:0% +which has + + + align:start position:0% +which has +to account for research which requires + 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align:start position:0% +pipe through + + + align:start position:0% +pipe through +there if we had been count if MIT would + + align:start position:0% +there if we had been count if MIT would + + + align:start position:0% +there if we had been count if MIT would +have allowed us to account for future + + align:start position:0% +have allowed us to account for future + + + align:start position:0% +have allowed us to account for future +flexibility we would have made the depth + + align:start position:0% +flexibility we would have made the depth + + + align:start position:0% +flexibility we would have made the depth +greater than the 18 in of TV it costs + + align:start position:0% +greater than the 18 in of TV it costs + + + align:start position:0% +greater than the 18 in of TV it costs +money we weren't allowed to plan the + + align:start position:0% +money we weren't allowed to plan the + + + align:start position:0% +money we weren't allowed to plan the +building with + + align:start position:0% +building with + + + align:start position:0% +building with +any space on the building called TBA to + + align:start position:0% +any space on the building called TBA to + + + align:start position:0% +any space on the building called TBA to +be + + align:start position:0% +be + + + align:start position:0% +be +added we had + + align:start position:0% + + + + align:start position:0% + +to it's like packing a aircraft + + align:start position:0% +to it's like packing a aircraft + + + align:start position:0% +to it's like packing a aircraft +carrier an aircraft carrier probably can + + align:start position:0% +carrier an aircraft carrier probably can + + + align:start position:0% +carrier an aircraft carrier probably can +change internally but anyway let's move + + align:start position:0% +change internally but anyway let's move + + + align:start position:0% +change internally but anyway let's move +on with this these + + align:start position:0% +on with this these + + + align:start position:0% +on with this these +diagrams got a few minutes + + align:start position:0% +diagrams got a few minutes + + + align:start position:0% +diagrams got a few minutes +left the pottery think belt of + + align:start position:0% + + + + align:start position:0% + +1966 with Cedric price the British + + align:start position:0% +1966 with Cedric price the British + + + align:start position:0% +1966 with Cedric price the British +Architects attempt to do a couple of + + align:start position:0% +Architects attempt to do a couple of + + + align:start position:0% +Architects attempt to do a couple of +things to eliminate the idea of a campus + + align:start position:0% +things to eliminate the idea of a campus + + + align:start position:0% +things to eliminate the idea of a campus +from having only having separateness + + align:start position:0% +from having only having separateness + + + align:start position:0% +from having only having separateness +from the rest of + + align:start position:0% + + + + align:start position:0% + +urbanism he decided to + + align:start position:0% +urbanism he decided to + + + align:start position:0% +urbanism he decided to +reuse the to place this British + + align:start position:0% +reuse the to place this British + + + align:start position:0% +reuse the to place this British +University in an area of suffering + + align:start position:0% +University in an area of suffering + + + align:start position:0% +University in an area of suffering +economic decline in + + align:start position:0% + + + + align:start position:0% + +Staffordshire he argued + + align:start position:0% + + + + align:start position:0% + +that this embedding of the University + + align:start position:0% +that this embedding of the University + + + align:start position:0% +that this embedding of the University +into the society's needs would + + align:start position:0% +into the society's needs would + + + align:start position:0% +into the society's needs would +spontaneously produce a another kind of + + align:start position:0% + + + + align:start position:0% + +University such as it would it would + + align:start position:0% +University such as it would it would + + + align:start position:0% +University such as it would it would +stimulate the economy for instance + + align:start position:0% +stimulate the economy for instance + + + align:start position:0% +stimulate the economy for instance +through a promoting a land lady + + align:start position:0% +through a promoting a land lady + + + align:start position:0% +through a promoting a land lady +industry and so + + align:start position:0% +industry and so + + + align:start position:0% +industry and so +on instead of building university + + align:start position:0% +on instead of building university + + + align:start position:0% +on instead of building university +dormitories I showed you a project + + align:start position:0% +dormitories I showed you a project + + + align:start position:0% +dormitories I showed you a project +in + + align:start position:0% + + + + align:start position:0% + +New + + align:start position:0% +New + + + align:start position:0% +New +York by the fort + + align:start position:0% + + + + align:start position:0% + +Foundation which attempted to do the + + align:start position:0% +Foundation which attempted to do the + + + align:start position:0% +Foundation which attempted to do the +same thing that instead of building + + align:start position:0% +same thing that instead of building + + + align:start position:0% +same thing that instead of building +university + + align:start position:0% +university + + + align:start position:0% +university +dormitories create a market for the + + align:start position:0% +dormitories create a market for the + + + align:start position:0% +dormitories create a market for the +supply of housing by the poor people + + align:start position:0% +supply of housing by the poor people + + + align:start position:0% +supply of housing by the poor people +around the + + align:start position:0% +around the + + + align:start position:0% +around the +University + + align:start position:0% + + + + align:start position:0% + +the last of these plans is the most + + align:start position:0% +the last of these plans is the most + + + align:start position:0% +the last of these plans is the most +famous of them it's the Free University + + align:start position:0% +famous of them it's the Free University + + + align:start position:0% +famous of them it's the Free University +in + + align:start position:0% + + + + align:start position:0% + +Bon Shadrick Woods + + align:start position:0% + + + + align:start position:0% + +writes about this + + align:start position:0% +writes about this + + + align:start position:0% +writes about this +plan we have not we have not begun by + + align:start position:0% +plan we have not we have not begun by + + + align:start position:0% +plan we have not we have not begun by +trying to give fixed points within the + + align:start position:0% +trying to give fixed points within the + + + align:start position:0% +trying to give fixed points within the +system I know they will have this people + + align:start position:0% +system I know they will have this people + + + align:start position:0% +system I know they will have this people +make the identical features not the + + align:start position:0% +make the identical features not the + + + align:start position:0% +make the identical features not the +architect I do not want to make any + + align:start position:0% +architect I do not want to make any + + + align:start position:0% +architect I do not want to make any +symbols to begin with I think that the + + align:start position:0% +symbols to begin with I think that the + + + align:start position:0% +symbols to begin with I think that the +use of the building creates centers of + + align:start position:0% +use of the building creates centers of + + + align:start position:0% +use of the building creates centers of +activity the plan is really an attempt + + align:start position:0% +activity the plan is really an attempt + + + align:start position:0% +activity the plan is really an attempt +not to make Center and so on to begin + + align:start position:0% + + + + align:start position:0% + +with it's interesting + + align:start position:0% + + + + align:start position:0% + +that the implication is that if you give + + align:start position:0% +that the implication is that if you give + + + align:start position:0% +that the implication is that if you give +a a an opportunity for people to arrange + + align:start position:0% +a a an opportunity for people to arrange + + + align:start position:0% +a a an opportunity for people to arrange +themselves they will have the capacity + + align:start position:0% +themselves they will have the capacity + + + align:start position:0% +themselves they will have the capacity +to do so in a correct manner or in a + + align:start position:0% +to do so in a correct manner or in a + + + align:start position:0% +to do so in a correct manner or in a +manner that is correct for + + align:start position:0% +manner that is correct for + + + align:start position:0% +manner that is correct for +them this is a time when CH n Chomsky + + align:start position:0% +them this is a time when CH n Chomsky + + + align:start position:0% +them this is a time when CH n Chomsky +was was lecturing + + align:start position:0% +was was lecturing + + + align:start position:0% +was was lecturing +about the innate ability of a child to + + align:start position:0% +about the innate ability of a child to + + + align:start position:0% +about the innate ability of a child to +construct a specific system of + + align:start position:0% +construct a specific system of + + + align:start position:0% +construct a specific system of +interconnection amongst + + align:start position:0% +interconnection amongst + + + align:start position:0% +interconnection amongst +Concepts and conditions of use and + + align:start position:0% +Concepts and conditions of use and + + + align:start position:0% +Concepts and conditions of use and +reference on the basis of of scatter + + align:start position:0% +reference on the basis of of scatter + + + align:start position:0% +reference on the basis of of scatter +scanty and Scattered + + align:start position:0% + + + + align:start position:0% + +evidence is there DNA in human + + align:start position:0% +evidence is there DNA in human + + + align:start position:0% +evidence is there DNA in human +beings which automatically will be able + + align:start position:0% +beings which automatically will be able + + + align:start position:0% +beings which automatically will be able +to create better space than a specialist + + align:start position:0% +to create better space than a specialist + + + align:start position:0% +to create better space than a specialist +guiding them or what combination of the + + align:start position:0% +guiding them or what combination of the + + + align:start position:0% +guiding them or what combination of the +two classical + + align:start position:0% +two classical + + + align:start position:0% +two classical +anarchism what would be the wisdom of + + align:start position:0% +anarchism what would be the wisdom of + + + align:start position:0% +anarchism what would be the wisdom of +the Clow in that sense + + align:start position:0% +the Clow in that sense + + + align:start position:0% +the Clow in that sense +well as I can only judge from from + + align:start position:0% +well as I can only judge from from + + + align:start position:0% +well as I can only judge from from +Shadrick Woods who was a very good + + align:start position:0% +Shadrick Woods who was a very good + + + align:start position:0% +Shadrick Woods who was a very good +architect um this is absolutely + + align:start position:0% +architect um this is absolutely + + + align:start position:0% +architect um this is absolutely +anti-classical + + align:start position:0% + + + + align:start position:0% + +the crowd will organize itself as it + + align:start position:0% +the crowd will organize itself as it + + + align:start position:0% +the crowd will organize itself as it +goes along and works and + + align:start position:0% +goes along and works and + + + align:start position:0% +goes along and works and +studies there will be a generation of + + align:start position:0% +studies there will be a generation of + + + align:start position:0% +studies there will be a generation of +space which will be more the result of + + align:start position:0% +space which will be more the result of + + + align:start position:0% +space which will be more the result of +the participation of the people then + + align:start position:0% +the participation of the people then + + + align:start position:0% +the participation of the people then +imposed on them I'm putting it rather + + align:start position:0% +imposed on them I'm putting it rather + + + align:start position:0% +imposed on them I'm putting it rather +crudely the notion that there is a DNA + + align:start position:0% +crudely the notion that there is a DNA + + + align:start position:0% +crudely the notion that there is a DNA +in all human beings according to + + align:start position:0% +in all human beings according to + + + align:start position:0% +in all human beings according to +Chomsky which allows the child to com + + align:start position:0% +Chomsky which allows the child to com + + + align:start position:0% +Chomsky which allows the child to com +construct complex sentences without + + align:start position:0% +construct complex sentences without + + + align:start position:0% +construct complex sentences without +having been told how to do + + align:start position:0% +having been told how to do + + + align:start position:0% +having been told how to do +it admittedly with the parents and + + align:start position:0% +it admittedly with the parents and + + + align:start position:0% +it admittedly with the parents and +society around them + + align:start position:0% +society around them + + + align:start position:0% +society around them +to guide + + align:start position:0% +to guide + + + align:start position:0% +to guide +them but ch is fairly well established + + align:start position:0% +them but ch is fairly well established + + + align:start position:0% +them but ch is fairly well established +as an authority now there's still + + align:start position:0% +as an authority now there's still + + + align:start position:0% +as an authority now there's still +controversies around whether the DNA of + + align:start position:0% +controversies around whether the DNA of + + + align:start position:0% +controversies around whether the DNA of +people have this capacity without much + + align:start position:0% + + + + align:start position:0% + +learning my own position about the Free + + align:start position:0% +learning my own position about the Free + + + align:start position:0% +learning my own position about the Free +University is a bad has had a bad + + align:start position:0% +University is a bad has had a bad + + + align:start position:0% +University is a bad has had a bad +history it's been vandalized it's been + + align:start position:0% +history it's been vandalized it's been + + + align:start position:0% +history it's been vandalized it's been +destroyed it's had to be + + align:start position:0% +destroyed it's had to be + + + align:start position:0% +destroyed it's had to be +rebuilt uh + + align:start position:0% +rebuilt uh + + + align:start position:0% +rebuilt uh +it never fulfilled the promise that wood + + align:start position:0% +it never fulfilled the promise that wood + + + align:start position:0% +it never fulfilled the promise that wood +had for + + align:start position:0% +had for + + + align:start position:0% +had for +it so what we see through look through + + align:start position:0% +it so what we see through look through + + + align:start position:0% +it so what we see through look through +all of these cases from Sussex in + + align:start position:0% +all of these cases from Sussex in + + + align:start position:0% +all of these cases from Sussex in +61 where the Armature of separated Camp + + align:start position:0% +61 where the Armature of separated Camp + + + align:start position:0% +61 where the Armature of separated Camp +items in a + + align:start position:0% +items in a + + + align:start position:0% +items in a +campus are + + align:start position:0% +campus are + + + align:start position:0% +campus are +dismantled into a + + align:start position:0% +dismantled into a + + + align:start position:0% +dismantled into a +system which is almost cybernetic in a + + align:start position:0% +system which is almost cybernetic in a + + + align:start position:0% +system which is almost cybernetic in a +sense + + align:start position:0% + + + + align:start position:0% + +free associations of networks created a + + align:start position:0% +free associations of networks created a + + + align:start position:0% +free associations of networks created a +freely over time suggesting new + + align:start position:0% + + + + align:start position:0% + +relationships the trouble with + + align:start position:0% +relationships the trouble with + + + align:start position:0% +relationships the trouble with +architecture is that it's not + + align:start position:0% + + + + align:start position:0% + +easy you just can't take a piece of + + align:start position:0% +easy you just can't take a piece of + + + align:start position:0% +easy you just can't take a piece of +paper and stick it on a wall the wall + + align:start position:0% +paper and stick it on a wall the wall + + + align:start position:0% +paper and stick it on a wall the wall +has to have + + align:start position:0% +has to have + + + align:start position:0% +has to have +bearing Acoustics unfortunately means + + align:start position:0% +bearing Acoustics unfortunately means + + + align:start position:0% +bearing Acoustics unfortunately means +that the only way to separate sound is + + align:start position:0% +that the only way to separate sound is + + + align:start position:0% +that the only way to separate sound is +with + + align:start position:0% + + + + align:start position:0% + +mass so University is the last place in + + align:start position:0% +mass so University is the last place in + + + align:start position:0% +mass so University is the last place in +the world to flitter around with stud + + align:start position:0% +the world to flitter around with stud + + + align:start position:0% +the world to flitter around with stud +walls or metal prefabricated metal + + align:start position:0% +walls or metal prefabricated metal + + + align:start position:0% +walls or metal prefabricated metal +panels if we had a prefabricated metal + + align:start position:0% +panels if we had a prefabricated metal + + + align:start position:0% +panels if we had a prefabricated metal +panel + + align:start position:0% +panel + + + align:start position:0% +panel +uninsulated we wouldn't be able to teach + + align:start position:0% +uninsulated we wouldn't be able to teach + + + align:start position:0% +uninsulated we wouldn't be able to teach +in this + + align:start position:0% +in this + + + align:start position:0% +in this +class so again the pan distribution + + align:start position:0% +class so again the pan distribution + + + align:start position:0% +class so again the pan distribution +might + + align:start position:0% +might + + + align:start position:0% +might +say might guide one into knowing the + + align:start position:0% +say might guide one into knowing the + + + align:start position:0% +say might guide one into knowing the +frequency of places which need acoustic + + align:start position:0% +frequency of places which need acoustic + + + align:start position:0% +frequency of places which need acoustic +separation versus those that don't in + + align:start position:0% +separation versus those that don't in + + + align:start position:0% +separation versus those that don't in +the same way that the laer possibility + + align:start position:0% +the same way that the laer possibility + + + align:start position:0% +the same way that the laer possibility +of making everything + + align:start position:0% +of making everything + + + align:start position:0% +of making everything +possible a pan distribution would say + + align:start position:0% +possible a pan distribution would say + + + align:start position:0% +possible a pan distribution would say +that the likelihood of wet Laboratories + + align:start position:0% +that the likelihood of wet Laboratories + + + align:start position:0% +that the likelihood of wet Laboratories +occurring in your campus or this and + + align:start position:0% +occurring in your campus or this and + + + align:start position:0% +occurring in your campus or this and +therefore you should only + + align:start position:0% +therefore you should only + + + align:start position:0% +therefore you should only +spend the money on a feasible uh + + align:start position:0% +spend the money on a feasible uh + + + align:start position:0% +spend the money on a feasible uh +solution which requires 70% of your + + align:start position:0% +solution which requires 70% of your + + + align:start position:0% +solution which requires 70% of your +buildings to have this + + align:start position:0% +buildings to have this + + + align:start position:0% +buildings to have this +flexibility the stata building has no + + align:start position:0% +flexibility the stata building has no + + + align:start position:0% +flexibility the stata building has no +wet Laboratories in it it has therefore + + align:start position:0% +wet Laboratories in it it has therefore + + + align:start position:0% +wet Laboratories in it it has therefore +it has nothing uh I mean if you knew + + align:start position:0% +it has nothing uh I mean if you knew + + + align:start position:0% +it has nothing uh I mean if you knew +architecture well enough you could look + + align:start position:0% +architecture well enough you could look + + + align:start position:0% +architecture well enough you could look +at the STA building in our building and + + align:start position:0% +at the STA building in our building and + + + align:start position:0% +at the STA building in our building and +compare them fundamentally and say the + + align:start position:0% +compare them fundamentally and say the + + + align:start position:0% +compare them fundamentally and say the +one has wet Laboratories the one doesn't + + align:start position:0% +one has wet Laboratories the one doesn't + + + align:start position:0% +one has wet Laboratories the one doesn't +doesn't have any by looking at the the + + align:start position:0% +doesn't have any by looking at the the + + + align:start position:0% +doesn't have any by looking at the the +amount of chimneys on the + + align:start position:0% +amount of chimneys on the + + + align:start position:0% +amount of chimneys on the +roof we have every kind of + + align:start position:0% +roof we have every kind of + + + align:start position:0% +roof we have every kind of +Chimney emanating smoke or gas whatever + + align:start position:0% +Chimney emanating smoke or gas whatever + + + align:start position:0% +Chimney emanating smoke or gas whatever +comes from + + align:start position:0% +comes from + + + align:start position:0% +comes from +MIT U the STA building has nothing it + + align:start position:0% +MIT U the STA building has nothing it + + + align:start position:0% +MIT U the STA building has nothing it +has a flat ceiling roof it's about the + + align:start position:0% +has a flat ceiling roof it's about the + + + align:start position:0% +has a flat ceiling roof it's about the +only flat plane in the + + align:start position:0% +only flat plane in the + + + align:start position:0% +only flat plane in the +building okay + + align:start position:0% +building okay + + + align:start position:0% +building okay +I want to look briefly at + + align:start position:0% + + + + align:start position:0% + +two other + + align:start position:0% +two other + + + align:start position:0% +two other +cases the one is + + align:start position:0% +cases the one is + + + align:start position:0% +cases the one is +the by the way there's a piece + + align:start position:0% +the by the way there's a piece + + + align:start position:0% +the by the way there's a piece +by William + + align:start position:0% +by William + + + align:start position:0% +by William +forcet in + + align:start position:0% +forcet in + + + align:start position:0% +forcet in +the MIT planning Journal of one of two + + align:start position:0% +the MIT planning Journal of one of two + + + align:start position:0% +the MIT planning Journal of one of two +volumes ago on flexible life + + align:start position:0% +volumes ago on flexible life + + + align:start position:0% +volumes ago on flexible life +flexibility + + align:start position:0% +flexibility + + + align:start position:0% +flexibility +it's called invested in investment in + + align:start position:0% +it's called invested in investment in + + + align:start position:0% +it's called invested in investment in +flexibility the life cycle options the + + align:start position:0% +flexibility the life cycle options the + + + align:start position:0% +flexibility the life cycle options the +synthesis he talks about he gives + + align:start position:0% +synthesis he talks about he gives + + + align:start position:0% +synthesis he talks about he gives +examples + + align:start position:0% +examples + + + align:start position:0% +examples +of prediction which is based on + + align:start position:0% +of prediction which is based on + + + align:start position:0% +of prediction which is based on +estimates of outcome and the costing of + + align:start position:0% +estimates of outcome and the costing of + + + align:start position:0% +estimates of outcome and the costing of +the estimates of outcome and the + + align:start position:0% +the estimates of outcome and the + + + align:start position:0% +the estimates of outcome and the +decision which is based + + align:start position:0% +decision which is based + + + align:start position:0% +decision which is based +on the + + align:start position:0% +on the + + + align:start position:0% +on the +system I'd also recommend that you read + + align:start position:0% +system I'd also recommend that you read + + + align:start position:0% +system I'd also recommend that you read +some something in Kevin Lynch's book + + align:start position:0% +some something in Kevin Lynch's book + + + align:start position:0% +some something in Kevin Lynch's book +what time is this + + align:start position:0% +what time is this + + + align:start position:0% +what time is this +place for an attempt to in the space + + align:start position:0% +place for an attempt to in the space + + + align:start position:0% +place for an attempt to in the space +time continuum to play around with the + + align:start position:0% +time continuum to play around with the + + + align:start position:0% +time continuum to play around with the +idea of + + align:start position:0% +idea of + + + align:start position:0% +idea of +time is a page in which he goes through + + align:start position:0% +time is a page in which he goes through + + + align:start position:0% +time is a page in which he goes through +a whole number of possibilities of + + align:start position:0% +a whole number of possibilities of + + + align:start position:0% +a whole number of possibilities of +changing + + align:start position:0% +changing + + + align:start position:0% +changing +time and its implic he doesn't speculate + + align:start position:0% +time and its implic he doesn't speculate + + + align:start position:0% +time and its implic he doesn't speculate +about his implications on + + align:start position:0% + + + + align:start position:0% + +space I'm going to skip a bunch of stuff + + align:start position:0% +space I'm going to skip a bunch of stuff + + + align:start position:0% +space I'm going to skip a bunch of stuff +and end with the last two because we + + align:start position:0% +and end with the last two because we + + + align:start position:0% +and end with the last two because we +won't have + + align:start position:0% + + + + align:start position:0% + +time I'll deal with + + align:start position:0% +time I'll deal with + + + align:start position:0% +time I'll deal with +this mainly through the + + align:start position:0% + + + + align:start position:0% + +slides I can't find the right + + align:start position:0% +slides I can't find the right + + + align:start position:0% +slides I can't find the right +place the two cases + + align:start position:0% + + + + align:start position:0% + +are the use of temporary environments of + + align:start position:0% +are the use of temporary environments of + + + align:start position:0% +are the use of temporary environments of +a fairly large scale in City + + align:start position:0% +a fairly large scale in City + + + align:start position:0% +a fairly large scale in City +the one is + + align:start position:0% + + + + align:start position:0% + +the story of Paris between 1855 in + + align:start position:0% +the story of Paris between 1855 in + + + align:start position:0% +the story of Paris between 1855 in +1900 after the success of the Crystal + + align:start position:0% +1900 after the success of the Crystal + + + align:start position:0% +1900 after the success of the Crystal +Palace exhibition in 1851 in London the + + align:start position:0% +Palace exhibition in 1851 in London the + + + align:start position:0% +Palace exhibition in 1851 in London the +French built an exhibition In + + align:start position:0% +French built an exhibition In + + + align:start position:0% +French built an exhibition In +1855 and almost every 11 years + + align:start position:0% +1855 and almost every 11 years + + + align:start position:0% +1855 and almost every 11 years +afterwards + + align:start position:0% +afterwards + + + align:start position:0% +afterwards + + align:start position:0% + + + align:start position:0% +1867 18 1878 + + align:start position:0% +1867 18 1878 + + + align:start position:0% +1867 18 1878 +1889 and + + align:start position:0% +1889 and + + + align:start position:0% +1889 and +1900 it had an exhibition a temporary + + align:start position:0% +1900 it had an exhibition a temporary + + + align:start position:0% +1900 it had an exhibition a temporary +exhibition a major temporary exhibition + + align:start position:0% +exhibition a major temporary exhibition + + + align:start position:0% +exhibition a major temporary exhibition +in the center of Paris just north of the + + align:start position:0% +in the center of Paris just north of the + + + align:start position:0% +in the center of Paris just north of the +S and largely south of the + + align:start position:0% + + + + align:start position:0% + +s i I'll go through some of the material + + align:start position:0% +s i I'll go through some of the material + + + align:start position:0% +s i I'll go through some of the material +with the slides + + align:start position:0% +with the slides + + + align:start position:0% +with the slides +but let me read you a quote from the + + align:start position:0% +but let me read you a quote from the + + + align:start position:0% +but let me read you a quote from the +French + + align:start position:0% + + + + align:start position:0% + +novelist Jean + + align:start position:0% + + + + align:start position:0% + +jiru about the existence of a temporary + + align:start position:0% +jiru about the existence of a temporary + + + align:start position:0% +jiru about the existence of a temporary +city as opposed in conjunction with a + + align:start position:0% +city as opposed in conjunction with a + + + align:start position:0% +city as opposed in conjunction with a +permanent + + align:start position:0% +permanent + + + align:start position:0% +permanent +City he's talking about the citizens of + + align:start position:0% +City he's talking about the citizens of + + + align:start position:0% +City he's talking about the citizens of +Paris they are delighted by the thought + + align:start position:0% +Paris they are delighted by the thought + + + align:start position:0% +Paris they are delighted by the thought +of reaching this cardboard or plaster + + align:start position:0% +of reaching this cardboard or plaster + + + align:start position:0% +of reaching this cardboard or plaster +City through the permanent Stone site of + + align:start position:0% +City through the permanent Stone site of + + + align:start position:0% +City through the permanent Stone site of +Paris what an extraordinary + + align:start position:0% + + + + align:start position:0% + +idea that part of your city is rotating + + align:start position:0% +idea that part of your city is rotating + + + align:start position:0% +idea that part of your city is rotating +at a faster speed than the other + + align:start position:0% + + + + align:start position:0% + +parts the Free University of villin has + + align:start position:0% +parts the Free University of villin has + + + align:start position:0% +parts the Free University of villin has +no stone sight it only has + + align:start position:0% +no stone sight it only has + + + align:start position:0% +no stone sight it only has +transparency maybe you need a balance + + align:start position:0% +transparency maybe you need a balance + + + align:start position:0% +transparency maybe you need a balance +between tone Stone sight and carboard + + align:start position:0% + + + + align:start position:0% + +in + + align:start position:0% +in + + + align:start position:0% +in +he goes + + align:start position:0% + + + + align:start position:0% + +on they do not come to see a disguised + + align:start position:0% +on they do not come to see a disguised + + + align:start position:0% +on they do not come to see a disguised +and + + align:start position:0% +and + + + align:start position:0% +and +transed + + align:start position:0% +transed + + + align:start position:0% +transed +Paris this is not a the exhibitions are + + align:start position:0% +Paris this is not a the exhibitions are + + + align:start position:0% +Paris this is not a the exhibitions are +not transverses Paris not changed Paris + + align:start position:0% +not transverses Paris not changed Paris + + + align:start position:0% +not transverses Paris not changed Paris +but they are unique they on their own + + align:start position:0% +but they are unique they on their own + + + align:start position:0% +but they are unique they on their own +they come attracted by the temporary + + align:start position:0% +they come attracted by the temporary + + + align:start position:0% +they come attracted by the temporary +Union of an ephemeral city with the + + align:start position:0% +Union of an ephemeral city with the + + + align:start position:0% +Union of an ephemeral city with the +millennial one the association of the + + align:start position:0% +millennial one the association of the + + + align:start position:0% +millennial one the association of the +most eccentric city with the most real + + align:start position:0% +most eccentric city with the most real + + + align:start position:0% +most eccentric city with the most real +and tangible one it's an extraordinary + + align:start position:0% +and tangible one it's an extraordinary + + + align:start position:0% +and tangible one it's an extraordinary +idea that you keep the center of your + + align:start position:0% +idea that you keep the center of your + + + align:start position:0% +idea that you keep the center of your +City to change at a more rapid + + align:start position:0% +City to change at a more rapid + + + align:start position:0% +City to change at a more rapid +rate in I'll show you slides of + + align:start position:0% +rate in I'll show you slides of + + + align:start position:0% +rate in I'll show you slides of + + align:start position:0% + + + align:start position:0% + + align:start position:0% + + + align:start position:0% +being the first structure and the + + align:start position:0% +being the first structure and the + + + align:start position:0% +being the first structure and the +demolition that take place within a + + align:start position:0% +demolition that take place within a + + + align:start position:0% +demolition that take place within a +period of 11 years so every child in the + + align:start position:0% +period of 11 years so every child in the + + + align:start position:0% +period of 11 years so every child in the +city is seeing construction and + + align:start position:0% + + + + align:start position:0% + +destruction until + + align:start position:0% + + + + align:start position:0% + +1900 of course the most significant + + align:start position:0% +1900 of course the most significant + + + align:start position:0% +1900 of course the most significant +event takes place in 1889 + + align:start position:0% +event takes place in 1889 + + + align:start position:0% +event takes place in 1889 +and considered a trans considered a + + align:start position:0% +and considered a trans considered a + + + align:start position:0% +and considered a trans considered a +temporary phenomenon the eel is the most + + align:start position:0% +temporary phenomenon the eel is the most + + + align:start position:0% +temporary phenomenon the eel is the most +permanent of all phenomena in + + align:start position:0% +permanent of all phenomena in + + + align:start position:0% +permanent of all phenomena in +Paris so again out of this temporary sea + + align:start position:0% +Paris so again out of this temporary sea + + + align:start position:0% +Paris so again out of this temporary sea +of change there are a couple of items + + align:start position:0% +of change there are a couple of items + + + align:start position:0% +of change there are a couple of items +which remain and log into a system of + + align:start position:0% +which remain and log into a system of + + + align:start position:0% +which remain and log into a system of +permanence although the Eiffel Tower was + + align:start position:0% +permanence although the Eiffel Tower was + + + align:start position:0% +permanence although the Eiffel Tower was +regarded as an + + align:start position:0% +regarded as an + + + align:start position:0% +regarded as an +American structure easily taken apart + + align:start position:0% +American structure easily taken apart + + + align:start position:0% +American structure easily taken apart +and assembl a fabricated structure + + align:start position:0% +and assembl a fabricated structure + + + align:start position:0% +and assembl a fabricated structure +unlike the solid neoclassical form of a + + align:start position:0% +unlike the solid neoclassical form of a + + + align:start position:0% +unlike the solid neoclassical form of a +Parisian + + align:start position:0% +Parisian + + + align:start position:0% +Parisian +facade the Trocadero which was on the + + align:start position:0% +facade the Trocadero which was on the + + + align:start position:0% +facade the Trocadero which was on the +other side of the sin in the 1878 the + + align:start position:0% +other side of the sin in the 1878 the + + + align:start position:0% +other side of the sin in the 1878 the +1889 exhibition was + + align:start position:0% +1889 exhibition was + + + align:start position:0% +1889 exhibition was +demolished although it was had a a + + align:start position:0% +demolished although it was had a a + + + align:start position:0% +demolished although it was had a a +plaster facade and looked as if it been + + align:start position:0% +plaster facade and looked as if it been + + + align:start position:0% +plaster facade and looked as if it been +there + + align:start position:0% +there + + + align:start position:0% +there +forever so these JX the positions are + + align:start position:0% +forever so these JX the positions are + + + align:start position:0% +forever so these JX the positions are +interesting in + + align:start position:0% +interesting in + + + align:start position:0% +interesting in +themselves the last and the most + + align:start position:0% +themselves the last and the most + + + align:start position:0% +themselves the last and the most +permanent of + + align:start position:0% +permanent of + + + align:start position:0% +permanent of +temporary phenomena is Olympic + + align:start position:0% + + + + align:start position:0% + +Games in + + align:start position:0% +Games in + + + align:start position:0% +Games in +1896 the Olympic Games was a an + + align:start position:0% +1896 the Olympic Games was a an + + + align:start position:0% +1896 the Olympic Games was a an +ex was an attempt to + + align:start position:0% + + + + align:start position:0% + +recapitulate one of Greek's on gree's + + align:start position:0% +recapitulate one of Greek's on gree's + + + align:start position:0% +recapitulate one of Greek's on gree's +ongoing + + align:start position:0% +ongoing + + + align:start position:0% +ongoing +Traditions that is the ancient site of + + align:start position:0% +Traditions that is the ancient site of + + + align:start position:0% +Traditions that is the ancient site of +Olympia 776 BC which consisted of two + + align:start position:0% +Olympia 776 BC which consisted of two + + + align:start position:0% +Olympia 776 BC which consisted of two +components a permanent religious + + align:start position:0% +components a permanent religious + + + align:start position:0% +components a permanent religious +component with priests dealing with + + align:start position:0% +component with priests dealing with + + + align:start position:0% +component with priests dealing with +flames and outdoor comp series of + + align:start position:0% +flames and outdoor comp series of + + + align:start position:0% +flames and outdoor comp series of +components gymnasia stadia + + align:start position:0% +components gymnasia stadia + + + align:start position:0% +components gymnasia stadia +pesta health spa and so on dealing with + + align:start position:0% +pesta health spa and so on dealing with + + + align:start position:0% +pesta health spa and so on dealing with +a a cultural attribute of the body being + + align:start position:0% +a a cultural attribute of the body being + + + align:start position:0% +a a cultural attribute of the body being +performed in competition every four + + align:start position:0% +performed in competition every four + + + align:start position:0% +performed in competition every four +years in + + align:start position:0% + + + + align:start position:0% + +1896 KU decided to make some mileage out + + align:start position:0% +1896 KU decided to make some mileage out + + + align:start position:0% +1896 KU decided to make some mileage out +of reclaiming this + + align:start position:0% +of reclaiming this + + + align:start position:0% +of reclaiming this +idea 1900 it the Olympic Games were held + + align:start position:0% +idea 1900 it the Olympic Games were held + + + align:start position:0% +idea 1900 it the Olympic Games were held +in Paris at the time of the 1900 + + align:start position:0% +in Paris at the time of the 1900 + + + align:start position:0% +in Paris at the time of the 1900 +Exposition there was no the Olympic + + align:start position:0% +Exposition there was no the Olympic + + + align:start position:0% +Exposition there was no the Olympic +Games was nothing it was a joke the + + align:start position:0% +Games was nothing it was a joke the + + + align:start position:0% +Games was nothing it was a joke the +exposition was everything the swimmers + + align:start position:0% +exposition was everything the swimmers + + + align:start position:0% +exposition was everything the swimmers +swim in + + align:start position:0% +swim in + + + align:start position:0% +swim in +the the races in the S The discus + + align:start position:0% +the the races in the S The discus + + + align:start position:0% +the the races in the S The discus +throwers had to throw their discus in + + align:start position:0% +throwers had to throw their discus in + + + align:start position:0% +throwers had to throw their discus in +the B Balon in amongst the + + align:start position:0% + + + + align:start position:0% + +trees but it was a signal event because + + align:start position:0% +trees but it was a signal event because + + + align:start position:0% +trees but it was a signal event because +you two two you do two + + align:start position:0% +you two two you do two + + + align:start position:0% +you two two you do two +vectors the growth of the exposition + + align:start position:0% +vectors the growth of the exposition + + + align:start position:0% +vectors the growth of the exposition +movement from 1855 to 1900 and then the + + align:start position:0% +movement from 1855 to 1900 and then the + + + align:start position:0% +movement from 1855 to 1900 and then the +decline of the exhibition movement and + + align:start position:0% +decline of the exhibition movement and + + + align:start position:0% +decline of the exhibition movement and +then the the Advent of the Olympic Games + + align:start position:0% +then the the Advent of the Olympic Games + + + align:start position:0% +then the the Advent of the Olympic Games +trans placing the + + align:start position:0% +trans placing the + + + align:start position:0% +trans placing the +exhibitions the 19 the games didn't + + align:start position:0% +exhibitions the 19 the games didn't + + + align:start position:0% +exhibitions the 19 the games didn't +succeed 194 it came to the United States + + align:start position:0% +succeed 194 it came to the United States + + + align:start position:0% +succeed 194 it came to the United States +in St Louis maybe you don't realize that + + align:start position:0% +in St Louis maybe you don't realize that + + + align:start position:0% +in St Louis maybe you don't realize that +the United States has had the + + align:start position:0% +the United States has had the + + + align:start position:0% +the United States has had the +games four times + + align:start position:0% + + + + align:start position:0% + +where New York LA and New York has never + + align:start position:0% +where New York LA and New York has never + + + align:start position:0% +where New York LA and New York has never +had the + + align:start position:0% +had the + + + align:start position:0% +had the +game Los Angeles had it twice in C2 and + + align:start position:0% +game Los Angeles had it twice in C2 and + + + align:start position:0% +game Los Angeles had it twice in C2 and +84 wasn't there Winter + + align:start position:0% + + + + align:start position:0% + +game that that's the Winter Olympic I'm + + align:start position:0% +game that that's the Winter Olympic I'm + + + align:start position:0% +game that that's the Winter Olympic I'm +talking about the summer games Lake plid + + align:start position:0% +talking about the summer games Lake plid + + + align:start position:0% +talking about the summer games Lake plid +was the Winter game where American + + align:start position:0% +was the Winter game where American + + + align:start position:0% +was the Winter game where American +hockey team beat the Russians and caused + + align:start position:0% +hockey team beat the Russians and caused + + + align:start position:0% +hockey team beat the Russians and caused +enormous xenophobia in this + + align:start position:0% +enormous xenophobia in this + + + align:start position:0% +enormous xenophobia in this +country um + + align:start position:0% +country um + + + align:start position:0% +country um +the Olympic Games really only took off + + align:start position:0% +the Olympic Games really only took off + + + align:start position:0% +the Olympic Games really only took off +in 32 in Los Angeles the modern games + + align:start position:0% +in 32 in Los Angeles the modern games + + + align:start position:0% +in 32 in Los Angeles the modern games +that is it's one of the his one of the + + align:start position:0% + + + + align:start position:0% + +remarkable events it was during the + + align:start position:0% +remarkable events it was during the + + + align:start position:0% +remarkable events it was during the +Depression + + align:start position:0% +Depression + + + align:start position:0% +Depression +years united only the French were + + align:start position:0% +years united only the French were + + + align:start position:0% +years united only the French were +allowed to drink + + align:start position:0% + + + + align:start position:0% + +alcohol oh it was remarkable it made a + + align:start position:0% +alcohol oh it was remarkable it made a + + + align:start position:0% +alcohol oh it was remarkable it made a +it made a million dollars profit despite + + align:start position:0% +it made a million dollars profit despite + + + align:start position:0% +it made a million dollars profit despite +the fact that there not many people + + align:start position:0% +the fact that there not many people + + + align:start position:0% +the fact that there not many people +could afford to + + align:start position:0% +could afford to + + + align:start position:0% +could afford to +come 36 was the acne of + + align:start position:0% +come 36 was the acne of + + + align:start position:0% +come 36 was the acne of +Hitler's performance in + + align:start position:0% +Hitler's performance in + + + align:start position:0% +Hitler's performance in +Berlin how much you think the the + + align:start position:0% +Berlin how much you think the the + + + align:start position:0% +Berlin how much you think the the +uh films of Len played that role + + align:start position:0% +uh films of Len played that role + + + align:start position:0% +uh films of Len played that role +in well any refen star's + + align:start position:0% +in well any refen star's + + + align:start position:0% +in well any refen star's +film at this + + align:start position:0% +film at this + + + align:start position:0% +film at this +1988 games in Soul I I was asked to do a + + align:start position:0% +1988 games in Soul I I was asked to do a + + + align:start position:0% +1988 games in Soul I I was asked to do a +presentation and I showed the + + align:start position:0% +presentation and I showed the + + + align:start position:0% +presentation and I showed the +introduction to Linny rell's film as + + align:start position:0% +introduction to Linny rell's film as + + + align:start position:0% +introduction to Linny rell's film as +opposed to the 84 Olympic Games in Los + + align:start position:0% +opposed to the 84 Olympic Games in Los + + + align:start position:0% +opposed to the 84 Olympic Games in Los +Angeles + + align:start position:0% +Angeles + + + align:start position:0% +Angeles +reenal in case you don't know Denny + + align:start position:0% +reenal in case you don't know Denny + + + align:start position:0% +reenal in case you don't know Denny +reenal she was the German she was the + + align:start position:0% +reenal she was the German she was the + + + align:start position:0% +reenal she was the German she was the +very cryptic and uh and uh all over the + + align:start position:0% +very cryptic and uh and uh all over the + + + align:start position:0% +very cryptic and uh and uh all over the +place + + align:start position:0% +place + + + align:start position:0% +place +German uh filmmaker who made Olympia + + align:start position:0% +German uh filmmaker who made Olympia + + + align:start position:0% +German uh filmmaker who made Olympia +she convinced Gobles and Hitler to + + align:start position:0% +she convinced Gobles and Hitler to + + + align:start position:0% +she convinced Gobles and Hitler to +record they were very proud of the fact + + align:start position:0% +record they were very proud of the fact + + + align:start position:0% +record they were very proud of the fact +that Hollywood couldn't make a film of + + align:start position:0% +that Hollywood couldn't make a film of + + + align:start position:0% +that Hollywood couldn't make a film of +the 32 + + align:start position:0% +the 32 + + + align:start position:0% +the 32 +games I'll show you some of the first + + align:start position:0% +games I'll show you some of the first + + + align:start position:0% +games I'll show you some of the first +still photographs from the 32 games but + + align:start position:0% +still photographs from the 32 games but + + + align:start position:0% +still photographs from the 32 games but +Hitler said we are going to make a + + align:start position:0% +Hitler said we are going to make a + + + align:start position:0% +Hitler said we are going to make a +film and I could go into some detail + + align:start position:0% +film and I could go into some detail + + + align:start position:0% +film and I could go into some detail +about the film but you can still find + + align:start position:0% +about the film but you can still find + + + align:start position:0% +about the film but you can still find +Olympia in the 7 11 not 711 what what is + + align:start position:0% +Olympia in the 7 11 not 711 what what is + + + align:start position:0% +Olympia in the 7 11 not 711 what what is +what what are the local sophisticated + + align:start position:0% +what what are the local sophisticated + + + align:start position:0% +what what are the local sophisticated +local video Outlets here in + + align:start position:0% +local video Outlets here in + + + align:start position:0% +local video Outlets here in +Cambridge I don't know it's all on your + + align:start position:0% +Cambridge I don't know it's all on your + + + align:start position:0% +Cambridge I don't know it's all on your +computer now yeah well if you can find + + align:start position:0% +computer now yeah well if you can find + + + align:start position:0% +computer now yeah well if you can find +it Michael if you can find it on your + + align:start position:0% +it Michael if you can find it on your + + + align:start position:0% +it Michael if you can find it on your +computer find + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +um let's look at these images I'm sorry + + align:start position:0% +um let's look at these images I'm sorry + + + align:start position:0% +um let's look at these images I'm sorry +I have to show uh I've written about the + + align:start position:0% +I have to show uh I've written about the + + + align:start position:0% +I have to show uh I've written about the +Olympic Games it's in the were reading + + align:start position:0% +Olympic Games it's in the were reading + + + align:start position:0% +Olympic Games it's in the were reading +for + + align:start position:0% +for + + + align:start position:0% +for +today + + align:start position:0% +today + + + align:start position:0% +today +uh I went to I've been to two Olympic + + align:start position:0% +uh I went to I've been to two Olympic + + + align:start position:0% +uh I went to I've been to two Olympic +Games this is the last meeting of cim + + align:start position:0% +Games this is the last meeting of cim + + + align:start position:0% +Games this is the last meeting of cim +and the arguments in aut too between the + + align:start position:0% +and the arguments in aut too between the + + + align:start position:0% +and the arguments in aut too between the +closed aesthetic of bbp's building in + + align:start position:0% +closed aesthetic of bbp's building in + + + align:start position:0% +closed aesthetic of bbp's building in +Milan and Jan Carlo's building in Mata + + align:start position:0% +Milan and Jan Carlo's building in Mata + + + align:start position:0% +Milan and Jan Carlo's building in Mata +in the south of Italy I haven't got time + + align:start position:0% +in the south of Italy I haven't got time + + + align:start position:0% +in the south of Italy I haven't got time +to go into + + align:start position:0% + + + + align:start position:0% + +next some of the projects of Team 10 + + align:start position:0% +next some of the projects of Team 10 + + + align:start position:0% +next some of the projects of Team 10 +this is Addison and Peter smithson's + + align:start position:0% +this is Addison and Peter smithson's + + + align:start position:0% +this is Addison and Peter smithson's +project for the golden Lane competition + + align:start position:0% +project for the golden Lane competition + + + align:start position:0% +project for the golden Lane competition +you'll see the drawing indicates an + + align:start position:0% +you'll see the drawing indicates an + + + align:start position:0% +you'll see the drawing indicates an +enormous attempt to create + + align:start position:0% +enormous attempt to create + + + align:start position:0% +enormous attempt to create +maximize + + align:start position:0% +maximize + + + align:start position:0% +maximize +communication almost every level has + + align:start position:0% +communication almost every level has + + + align:start position:0% +communication almost every level has +people on it doing something or + + align:start position:0% +people on it doing something or + + + align:start position:0% +people on it doing something or +other yeah is a building which takes + + align:start position:0% +other yeah is a building which takes + + + align:start position:0% +other yeah is a building which takes +linear form and people are supposed to + + align:start position:0% +linear form and people are supposed to + + + align:start position:0% +linear form and people are supposed to +con + + align:start position:0% +con + + + align:start position:0% +con +to socially condensed to use the Russian + + align:start position:0% +to socially condensed to use the Russian + + + align:start position:0% +to socially condensed to use the Russian +term uh it's absolute + + align:start position:0% + + + + align:start position:0% + +nonsense I lived in when I came to + + align:start position:0% +nonsense I lived in when I came to + + + align:start position:0% +nonsense I lived in when I came to +America I lived in under Memorial + + align:start position:0% + + + + align:start position:0% + +Drive it's a skip stop elevator building + + align:start position:0% +Drive it's a skip stop elevator building + + + align:start position:0% +Drive it's a skip stop elevator building +which means that you have three times + + align:start position:0% +which means that you have three times + + + align:start position:0% +which means that you have three times +the volume going into the + + align:start position:0% +the volume going into the + + + align:start position:0% +the volume going into the +elevator I picked up a newspaper every + + align:start position:0% +elevator I picked up a newspaper every + + + align:start position:0% +elevator I picked up a newspaper every +morning uh quite early in the morning + + align:start position:0% +morning uh quite early in the morning + + + align:start position:0% +morning uh quite early in the morning +outside the front of the door I never in + + align:start position:0% +outside the front of the door I never in + + + align:start position:0% +outside the front of the door I never in +10 years ever saw another person in the + + align:start position:0% + + + + align:start position:0% + +corridor + + align:start position:0% +corridor + + + align:start position:0% +corridor +next parkel Sheffield one of the + + align:start position:0% +next parkel Sheffield one of the + + + align:start position:0% +next parkel Sheffield one of the +outgrows of this system it's now being + + align:start position:0% +outgrows of this system it's now being + + + align:start position:0% +outgrows of this system it's now being +rehabilitated and changed you can see + + align:start position:0% +rehabilitated and changed you can see + + + align:start position:0% +rehabilitated and changed you can see +again the whole idea + + align:start position:0% +again the whole idea + + + align:start position:0% +again the whole idea +of The + + align:start position:0% +of The + + + align:start position:0% +of The +Pedestrian + + align:start position:0% +Pedestrian + + + align:start position:0% +Pedestrian +sidewalk which is in sidewalk elevated + + align:start position:0% +sidewalk which is in sidewalk elevated + + + align:start position:0% +sidewalk which is in sidewalk elevated +in + + align:start position:0% +in + + + align:start position:0% +in +space is that people will use it + + align:start position:0% +space is that people will use it + + + align:start position:0% +space is that people will use it +to they just too few people in a + + align:start position:0% +to they just too few people in a + + + align:start position:0% +to they just too few people in a +building of this kind in most + + align:start position:0% +building of this kind in most + + + align:start position:0% +building of this kind in most +residential buildings to generate + + align:start position:0% +residential buildings to generate + + + align:start position:0% +residential buildings to generate +enough as if communicating with + + align:start position:0% +enough as if communicating with + + + align:start position:0% +enough as if communicating with +everybody who lives next to you is a + + align:start position:0% +everybody who lives next to you is a + + + align:start position:0% +everybody who lives next to you is a +good idea + + align:start position:0% + + + + align:start position:0% + +I mean it's it's it's it's a strange + + align:start position:0% +I mean it's it's it's it's a strange + + + align:start position:0% +I mean it's it's it's it's a strange +it's a strange notion in our thinking + + align:start position:0% +it's a strange notion in our thinking + + + align:start position:0% +it's a strange notion in our thinking +about + + align:start position:0% +about + + + align:start position:0% +about +urbanism that we all + + align:start position:0% +urbanism that we all + + + align:start position:0% +urbanism that we all +Greeks meeting in the Agra to discuss + + align:start position:0% +Greeks meeting in the Agra to discuss + + + align:start position:0% +Greeks meeting in the Agra to discuss +our local + + align:start position:0% +our local + + + align:start position:0% +our local +politics + + align:start position:0% +politics + + + align:start position:0% +politics +uh the all kind we'll come back to this + + align:start position:0% +uh the all kind we'll come back to this + + + align:start position:0% +uh the all kind we'll come back to this +in talking about the Contemporary + + align:start position:0% +in talking about the Contemporary + + + align:start position:0% +in talking about the Contemporary +American City but there's a mistaken + + align:start position:0% +American City but there's a mistaken + + + align:start position:0% +American City but there's a mistaken +notion I think sometimes argued by + + align:start position:0% +notion I think sometimes argued by + + + align:start position:0% +notion I think sometimes argued by +Richard Senate + + align:start position:0% +Richard Senate + + + align:start position:0% +Richard Senate +mistakenly that + + align:start position:0% +mistakenly that + + + align:start position:0% +mistakenly that +uh density of + + align:start position:0% +uh density of + + + align:start position:0% +uh density of +population provides intercourse between + + align:start position:0% +population provides intercourse between + + + align:start position:0% +population provides intercourse between +people in a very spontaneous way yes you + + align:start position:0% +people in a very spontaneous way yes you + + + align:start position:0% +people in a very spontaneous way yes you +can only get married to somebody you + + align:start position:0% + + + + align:start position:0% + +meet and py next + + align:start position:0% + + + + align:start position:0% + +another notion by candidas jich and + + align:start position:0% +another notion by candidas jich and + + + align:start position:0% +another notion by candidas jich and +Shadrick Woods's firm the town of the + + align:start position:0% +Shadrick Woods's firm the town of the + + + align:start position:0% +Shadrick Woods's firm the town of the +extension of tulus + + align:start position:0% +extension of tulus + + + align:start position:0% +extension of tulus +tulus the notion of the web a web is an + + align:start position:0% +tulus the notion of the web a web is an + + + align:start position:0% +tulus the notion of the web a web is an +architect geometric form which is meant + + align:start position:0% +architect geometric form which is meant + + + align:start position:0% +architect geometric form which is meant +to produce important + + align:start position:0% + + + + align:start position:0% + +intersections + + align:start position:0% + + + + align:start position:0% + +next per is dark okay this is in your + + align:start position:0% +next per is dark okay this is in your + + + align:start position:0% +next per is dark okay this is in your +handout this is the the story of Shand + + align:start position:0% +handout this is the the story of Shand + + + align:start position:0% +handout this is the the story of Shand +reurbanization + + align:start position:0% + + + + align:start position:0% + +chandigar you start off by + + align:start position:0% +chandigar you start off by + + + align:start position:0% +chandigar you start off by +building a few things over time these + + align:start position:0% +building a few things over time these + + + align:start position:0% +building a few things over time these +get added to and added to and added to + + align:start position:0% +get added to and added to and added to + + + align:start position:0% +get added to and added to and added to +and added to and the plan of the central + + align:start position:0% +and added to and the plan of the central + + + align:start position:0% +and added to and the plan of the central +part of + + align:start position:0% +part of + + + align:start position:0% +part of +Kier changes over time as + + align:start position:0% +Kier changes over time as + + + align:start position:0% +Kier changes over time as +the growth is a + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +consistent all along so you start with + + align:start position:0% + + + + align:start position:0% + +very as I think Lou KH said you I'd like + + align:start position:0% +very as I think Lou KH said you I'd like + + + align:start position:0% +very as I think Lou KH said you I'd like +to build the town in when he was working + + align:start position:0% +to build the town in when he was working + + + align:start position:0% +to build the town in when he was working +in + + align:start position:0% +in + + + align:start position:0% +in +Daka uh first out of mud and bricks and + + align:start position:0% +Daka uh first out of mud and bricks and + + + align:start position:0% +Daka uh first out of mud and bricks and +in the end that it will become a city of + + align:start position:0% +in the end that it will become a city of + + + align:start position:0% +in the end that it will become a city of +gold something like + + align:start position:0% +gold something like + + + align:start position:0% +gold something like +that + + align:start position:0% + + + + align:start position:0% + +next FIS dark is pro the ultimate goal + + align:start position:0% +next FIS dark is pro the ultimate goal + + + align:start position:0% +next FIS dark is pro the ultimate goal +would be + + align:start position:0% +would be + + + align:start position:0% +would be +to exhaust the center of chandigar by + + align:start position:0% +to exhaust the center of chandigar by + + + align:start position:0% +to exhaust the center of chandigar by +new construction additions that's the + + align:start position:0% +new construction additions that's the + + + align:start position:0% +new construction additions that's the +Secretariat building in the distance and + + align:start position:0% +Secretariat building in the distance and + + + align:start position:0% +Secretariat building in the distance and +in the case of Lou + + align:start position:0% +in the case of Lou + + + align:start position:0% +in the case of Lou +Khan's Central comp Lex in + + align:start position:0% + + + + align:start position:0% + +daa Dar says + + align:start position:0% +daa Dar says + + + align:start position:0% +daa Dar says +that you can through selective additive + + align:start position:0% +that you can through selective additive + + + align:start position:0% +that you can through selective additive +transformation you can change the city + + align:start position:0% +transformation you can change the city + + + align:start position:0% +transformation you can change the city +and build on existing systems rather + + align:start position:0% +and build on existing systems rather + + + align:start position:0% +and build on existing systems rather +than create something from scratch every + + align:start position:0% +than create something from scratch every + + + align:start position:0% +than create something from scratch every +time in a finished way + + align:start position:0% + + + + align:start position:0% + +next the MIT campus which you all know + + align:start position:0% +next the MIT campus which you all know + + + align:start position:0% +next the MIT campus which you all know +well that's a diagram + + align:start position:0% + + + + align:start position:0% + +from Maria's thesis the + + align:start position:0% +from Maria's thesis the + + + align:start position:0% +from Maria's thesis the +project for the new University of borham + + align:start position:0% +project for the new University of borham + + + align:start position:0% +project for the new University of borham +in Germany by + + align:start position:0% +in Germany by + + + align:start position:0% +in Germany by +cand Jos and + + align:start position:0% +cand Jos and + + + align:start position:0% +cand Jos and +woods it has no + + align:start position:0% +woods it has no + + + align:start position:0% +woods it has no +elevations on the + + align:start position:0% +elevations on the + + + align:start position:0% +elevations on the +outskirts they are just points of growth + + align:start position:0% +outskirts they are just points of growth + + + align:start position:0% +outskirts they are just points of growth +and expansion they stop expanding with + + align:start position:0% +and expansion they stop expanding with + + + align:start position:0% +and expansion they stop expanding with +the topography + + align:start position:0% +the topography + + + align:start position:0% +the topography +curtails expansion there's a central + + align:start position:0% +curtails expansion there's a central + + + align:start position:0% +curtails expansion there's a central +line through the system but the old idea + + align:start position:0% +line through the system but the old idea + + + align:start position:0% +line through the system but the old idea +is that this is A Spacetime + + align:start position:0% +is that this is A Spacetime + + + align:start position:0% +is that this is A Spacetime +configuration that can change at a speed + + align:start position:0% +configuration that can change at a speed + + + align:start position:0% +configuration that can change at a speed +which is not yet determined + + align:start position:0% + + + + align:start position:0% + +next the University of gor + + align:start position:0% +next the University of gor + + + align:start position:0% +next the University of gor +competition the university is a set of + + align:start position:0% +competition the university is a set of + + + align:start position:0% +competition the university is a set of +spaces colored in red and blue with + + align:start position:0% +spaces colored in red and blue with + + + align:start position:0% +spaces colored in red and blue with +different rates of change forget about + + align:start position:0% +different rates of change forget about + + + align:start position:0% +different rates of change forget about +the one on the right that's the + + align:start position:0% +the one on the right that's the + + + align:start position:0% +the one on the right that's the +University of pava by John Carlo deardo + + align:start position:0% +University of pava by John Carlo deardo + + + align:start position:0% +University of pava by John Carlo deardo +next lafra the 50t by 50t module footy + + align:start position:0% + + + + align:start position:0% + +serviced next the + + align:start position:0% +serviced next the + + + align:start position:0% +serviced next the +french Paris story in the Olympic + + align:start position:0% + + + + align:start position:0% + +Games this this is the the white space + + align:start position:0% +Games this this is the the white space + + + align:start position:0% +Games this this is the the white space +is the transformed white space of the + + align:start position:0% +is the transformed white space of the + + + align:start position:0% +is the transformed white space of the +center of + + align:start position:0% +center of + + + align:start position:0% +center of +Paris uh from 1855 to 1900 on the right + + align:start position:0% +Paris uh from 1855 to 1900 on the right + + + align:start position:0% +Paris uh from 1855 to 1900 on the right +of the + + align:start position:0% + + + + align:start position:0% + +various Exposition + + align:start position:0% +various Exposition + + + align:start position:0% +various Exposition +artifacts on the middle at the top is + + align:start position:0% +artifacts on the middle at the top is + + + align:start position:0% +artifacts on the middle at the top is +the first + + align:start position:0% +the first + + + align:start position:0% +the first + + align:start position:0% + + + align:start position:0% +Pavilion on the + + align:start position:0% +Pavilion on the + + + align:start position:0% +Pavilion on the +Shan 1900 they rebuilt as they are today + + align:start position:0% +Shan 1900 they rebuilt as they are today + + + align:start position:0% +Shan 1900 they rebuilt as they are today +and link to a system across the sand on + + align:start position:0% +and link to a system across the sand on + + + align:start position:0% +and link to a system across the sand on +the south 1867 on the + + align:start position:0% +the south 1867 on the + + + align:start position:0% +the south 1867 on the +left is the perfect around the world + + align:start position:0% +left is the perfect around the world + + + align:start position:0% +left is the perfect around the world +form + + align:start position:0% +form + + + align:start position:0% +form + + align:start position:0% + + + align:start position:0% +68 it crosses the sin and the it builds + + align:start position:0% +68 it crosses the sin and the it builds + + + align:start position:0% +68 it crosses the sin and the it builds +the EMP gadir on the on the Left Bank no + + align:start position:0% +the EMP gadir on the on the Left Bank no + + + align:start position:0% +the EMP gadir on the on the Left Bank no +it's on the right Bank in + + align:start position:0% +it's on the right Bank in + + + align:start position:0% +it's on the right Bank in +French uh and so on get the Advent of + + align:start position:0% +French uh and so on get the Advent of + + + align:start position:0% +French uh and so on get the Advent of +the Eiffel Tower + + align:start position:0% +the Eiffel Tower + + + align:start position:0% +the Eiffel Tower +here + + align:start position:0% +here + + + align:start position:0% +here +1889 you have the contrast between the + + align:start position:0% +1889 you have the contrast between the + + + align:start position:0% +1889 you have the contrast between the +the parent temporar of this building and + + align:start position:0% +the parent temporar of this building and + + + align:start position:0% +the parent temporar of this building and +the parent permanence of + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +1937 this one goes but the Eiffel Tower + + align:start position:0% +1937 this one goes but the Eiffel Tower + + + align:start position:0% +1937 this one goes but the Eiffel Tower +stays + + align:start position:0% + + + + align:start position:0% + +next 1855 and the two buildings + + align:start position:0% +next 1855 and the two buildings + + + align:start position:0% +next 1855 and the two buildings +just west of the + + align:start position:0% +just west of the + + + align:start position:0% +just west of the +blue uh + + align:start position:0% +blue uh + + + align:start position:0% +blue uh +sh continuing years the + + align:start position:0% +sh continuing years the + + + align:start position:0% +sh continuing years the +sh and the two replacement buildings for + + align:start position:0% +sh and the two replacement buildings for + + + align:start position:0% +sh and the two replacement buildings for +the 1900 + + align:start position:0% +the 1900 + + + align:start position:0% +the 1900 +Exposition uh I can't reach with my hand + + align:start position:0% +Exposition uh I can't reach with my hand + + + align:start position:0% +Exposition uh I can't reach with my hand +next the + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +next + + align:start position:0% + + + + align:start position:0% + +1867 you over 11 years you see this + + align:start position:0% +1867 you over 11 years you see this + + + align:start position:0% +1867 you over 11 years you see this +cycle every time in the construction of + + align:start position:0% +cycle every time in the construction of + + + align:start position:0% +cycle every time in the construction of +something which is ephemeral then it is + + align:start position:0% +something which is ephemeral then it is + + + align:start position:0% +something which is ephemeral then it is +this is + + align:start position:0% +this is + + + align:start position:0% +this is +1867 being removed + + align:start position:0% +1867 being removed + + + align:start position:0% +1867 being removed +next Del's + + align:start position:0% +next Del's + + + align:start position:0% +next Del's +painting the this painting + + align:start position:0% +painting the this painting + + + align:start position:0% +painting the this painting +has a number of features about the + + align:start position:0% +has a number of features about the + + + align:start position:0% +has a number of features about the +existential condition of the G the tyel + + align:start position:0% +existential condition of the G the tyel + + + align:start position:0% +existential condition of the G the tyel +tower as a symbol in the city and here + + align:start position:0% +tower as a symbol in the city and here + + + align:start position:0% +tower as a symbol in the city and here +is an example of a classical system + + align:start position:0% +is an example of a classical system + + + align:start position:0% +is an example of a classical system +which has much meaning apparent meaning + + align:start position:0% +which has much meaning apparent meaning + + + align:start position:0% +which has much meaning apparent meaning +embedded in it but is easily removable + + align:start position:0% +embedded in it but is easily removable + + + align:start position:0% +embedded in it but is easily removable +as opposed to that you can contrast the + + align:start position:0% +as opposed to that you can contrast the + + + align:start position:0% +as opposed to that you can contrast the +meaning of these two IM items in the + + align:start position:0% +meaning of these two IM items in the + + + align:start position:0% +meaning of these two IM items in the +urban + + align:start position:0% + + + + align:start position:0% + +system why is the Eiffel Tower still + + align:start position:0% + + + + align:start position:0% + +there it produces more income than any + + align:start position:0% +there it produces more income than any + + + align:start position:0% +there it produces more income than any +other public feature in in + + align:start position:0% +other public feature in in + + + align:start position:0% +other public feature in in +Paris + + align:start position:0% +Paris + + + align:start position:0% +Paris +Paris is the largest tourist city in the + + align:start position:0% +Paris is the largest tourist city in the + + + align:start position:0% +Paris is the largest tourist city in the +world it spends more money per capita on + + align:start position:0% +world it spends more money per capita on + + + align:start position:0% +world it spends more money per capita on +cleaning the city than any other city in + + align:start position:0% +cleaning the city than any other city in + + + align:start position:0% +cleaning the city than any other city in +the + + align:start position:0% +the + + + align:start position:0% +the +world city comments + + align:start position:0% + + + + align:start position:0% + +next and the final resolution 1937 with + + align:start position:0% +next and the final resolution 1937 with + + + align:start position:0% +next and the final resolution 1937 with +the two winners are the Russian Pavilion + + align:start position:0% +the two winners are the Russian Pavilion + + + align:start position:0% +the two winners are the Russian Pavilion +and the German + + align:start position:0% +and the German + + + align:start position:0% +and the German +Pavilion + + align:start position:0% +Pavilion + + + align:start position:0% +Pavilion +our friend melnikov's design for the 37 + + align:start position:0% +our friend melnikov's design for the 37 + + + align:start position:0% +our friend melnikov's design for the 37 +Exposition was never built + + align:start position:0% + + + + align:start position:0% + +next the plan of the original Olympic + + align:start position:0% +next the plan of the original Olympic + + + align:start position:0% +next the plan of the original Olympic +Games the inner core of the Temple of + + align:start position:0% +Games the inner core of the Temple of + + + align:start position:0% +Games the inner core of the Temple of +zus and + + align:start position:0% +zus and + + + align:start position:0% +zus and +Hera and outside the pester the + + align:start position:0% +Hera and outside the pester the + + + align:start position:0% +Hera and outside the pester the +wrestling the gymnasium the bathouses + + align:start position:0% +wrestling the gymnasium the bathouses + + + align:start position:0% +wrestling the gymnasium the bathouses +the guest + + align:start position:0% +the guest + + + align:start position:0% +the guest +house the Hippodrome and the stadium so + + align:start position:0% +house the Hippodrome and the stadium so + + + align:start position:0% +house the Hippodrome and the stadium so +the + + align:start position:0% +the + + + align:start position:0% +the +the plan for the Olympic Games in Munich + + align:start position:0% +the plan for the Olympic Games in Munich + + + align:start position:0% +the plan for the Olympic Games in Munich +in 19 when was Munich + + align:start position:0% +in 19 when was Munich + + + align:start position:0% +in 19 when was Munich +72 I think 72 68 was Mexico City I used + + align:start position:0% +72 I think 72 68 was Mexico City I used + + + align:start position:0% +72 I think 72 68 was Mexico City I used +to know the dates all but I'm + + align:start position:0% +to know the dates all but I'm + + + align:start position:0% +to know the dates all but I'm +sorry + + align:start position:0% + + + + align:start position:0% + +next + + align:start position:0% +next + + + align:start position:0% +next +1896 in + + align:start position:0% +1896 in + + + align:start position:0% +1896 in +Athens + + align:start position:0% +Athens + + + align:start position:0% +Athens +1900 in Paris + + align:start position:0% + + + + align:start position:0% + +next 194 in the United States which is + + align:start position:0% +next 194 in the United States which is + + + align:start position:0% +next 194 in the United States which is +part of an + + align:start position:0% +part of an + + + align:start position:0% +part of an +international much like Paris in 1900 + + align:start position:0% +international much like Paris in 1900 + + + align:start position:0% +international much like Paris in 1900 +1904 was part of an International + + align:start position:0% +1904 was part of an International + + + align:start position:0% +1904 was part of an International +Festival + + align:start position:0% + + + + align:start position:0% + +year Bushman from South Africa produced + + align:start position:0% +year Bushman from South Africa produced + + + align:start position:0% +year Bushman from South Africa produced +to + + align:start position:0% +to + + + align:start position:0% +to +dance + + align:start position:0% +dance + + + align:start position:0% +dance +Bushman started running in the marathon + + align:start position:0% +Bushman started running in the marathon + + + align:start position:0% +Bushman started running in the marathon +were chased off the course by + + align:start position:0% +were chased off the course by + + + align:start position:0% +were chased off the course by +dogs and didn't + + align:start position:0% +dogs and didn't + + + align:start position:0% +dogs and didn't +finish the whole system + + align:start position:0% +finish the whole system + + + align:start position:0% +finish the whole system +was the + + align:start position:0% +was the + + + align:start position:0% +was the +museum the Museum + + align:start position:0% +museum the Museum + + + align:start position:0% +museum the Museum +of the great wonderful Museum of St + + align:start position:0% +of the great wonderful Museum of St + + + align:start position:0% +of the great wonderful Museum of St +Louis the art museum of St Louis is + + align:start position:0% +Louis the art museum of St Louis is + + + align:start position:0% +Louis the art museum of St Louis is +still based on the site of the original + + align:start position:0% +still based on the site of the original + + + align:start position:0% +still based on the site of the original +Exposition in + + align:start position:0% +Exposition in + + + align:start position:0% +Exposition in + + align:start position:0% + + + align:start position:0% +next now + + align:start position:0% + + + + align:start position:0% + +1932 this is one of the wonderful set of + + align:start position:0% +1932 this is one of the wonderful set of + + + align:start position:0% +1932 this is one of the wonderful set of +still photographs taken of the games in + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +next + + align:start position:0% +next + + + align:start position:0% +next +interesting here we have for the first + + align:start position:0% +interesting here we have for the first + + + align:start position:0% +interesting here we have for the first +time the ReUse of a + + align:start position:0% +time the ReUse of a + + + align:start position:0% +time the ReUse of a +stadium on the left is the vice + + align:start position:0% +stadium on the left is the vice + + + align:start position:0% +stadium on the left is the vice +president of the United States in person + + align:start position:0% +president of the United States in person + + + align:start position:0% +president of the United States in person +Mr Garner I think his name was Ghana at + + align:start position:0% +Mr Garner I think his name was Ghana at + + + align:start position:0% +Mr Garner I think his name was Ghana at +opening of the exhibition in 1984 + + align:start position:0% +opening of the exhibition in 1984 + + + align:start position:0% +opening of the exhibition in 1984 +security is so tight that the President + + align:start position:0% +security is so tight that the President + + + align:start position:0% +security is so tight that the President +Ronald Reagan appears only + + align:start position:0% +Ronald Reagan appears only + + + align:start position:0% +Ronald Reagan appears only +electronically but the building Remains + + align:start position:0% +electronically but the building Remains + + + align:start position:0% +electronically but the building Remains +the + + align:start position:0% + + + + align:start position:0% + +Same one of the extraordinary things + + align:start position:0% +Same one of the extraordinary things + + + align:start position:0% +Same one of the extraordinary things +well we'll see it in the next slide + + align:start position:0% +well we'll see it in the next slide + + + align:start position:0% +well we'll see it in the next slide +next bin in 36 the flame from the + + align:start position:0% +next bin in 36 the flame from the + + + align:start position:0% +next bin in 36 the flame from the +connection to original + + align:start position:0% +connection to original + + + align:start position:0% +connection to original +area in Greece and arriving in Berlin + + align:start position:0% +area in Greece and arriving in Berlin + + + align:start position:0% +area in Greece and arriving in Berlin +with Hitler on the stadium + + align:start position:0% +with Hitler on the stadium + + + align:start position:0% +with Hitler on the stadium +Podium + + align:start position:0% + + + + align:start position:0% + +next sorry I think that's the wrong + + align:start position:0% +next sorry I think that's the wrong + + + align:start position:0% +next sorry I think that's the wrong +slide on + + align:start position:0% + + + + align:start position:0% + +the the slide that's supposed to be on + + align:start position:0% +the the slide that's supposed to be on + + + align:start position:0% +the the slide that's supposed to be on +the left shows the network of the Los + + align:start position:0% +the left shows the network of the Los + + + align:start position:0% +the left shows the network of the Los +Angeles 8 4 32 and 84 Stadium + + align:start position:0% +Angeles 8 4 32 and 84 Stadium + + + align:start position:0% +Angeles 8 4 32 and 84 Stadium +Transportation wise it has worked + + align:start position:0% +Transportation wise it has worked + + + align:start position:0% +Transportation wise it has worked +remarkably well because it allows + + align:start position:0% +remarkably well because it allows + + + align:start position:0% +remarkably well because it allows +distribution of traffic in every 360 + + align:start position:0% +distribution of traffic in every 360 + + + align:start position:0% +distribution of traffic in every 360 +directions 360 Dee + + align:start position:0% +directions 360 Dee + + + align:start position:0% +directions 360 Dee +directions um this is + + align:start position:0% +directions um this is + + + align:start position:0% +directions um this is +spar's project for Hitler for 400,000 + + align:start position:0% +spar's project for Hitler for 400,000 + + + align:start position:0% +spar's project for Hitler for 400,000 +people which would eliminate the Olympic + + align:start position:0% +people which would eliminate the Olympic + + + align:start position:0% +people which would eliminate the Olympic +Games + + align:start position:0% +Games + + + align:start position:0% +Games +configuration and hard be able to + + align:start position:0% +configuration and hard be able to + + + align:start position:0% +configuration and hard be able to +anybody to see + + align:start position:0% + + + + align:start position:0% + +next some of the plans this is + + align:start position:0% +next some of the plans this is + + + align:start position:0% +next some of the plans this is +so most of these stadia are built on the + + align:start position:0% +so most of these stadia are built on the + + + align:start position:0% +so most of these stadia are built on the +few on the on + + align:start position:0% +few on the on + + + align:start position:0% +few on the on +Parkland the wonderful olypic Village + + align:start position:0% +Parkland the wonderful olypic Village + + + align:start position:0% +Parkland the wonderful olypic Village +byang at the + + align:start position:0% +byang at the + + + align:start position:0% +byang at the +top + + align:start position:0% + + + + align:start position:0% + +next I just cut out most of the + + align:start position:0% +next I just cut out most of the + + + align:start position:0% +next I just cut out most of the +other + + align:start position:0% +other + + + align:start position:0% +other +slides this + + align:start position:0% + + + + align:start position:0% + +is two aspects of the + + align:start position:0% +is two aspects of the + + + align:start position:0% +is two aspects of the +American of the couple of aspects of the + + align:start position:0% +American of the couple of aspects of the + + + align:start position:0% +American of the couple of aspects of the +Olympic Games Olympic games are tempor + + align:start position:0% +Olympic Games Olympic games are tempor + + + align:start position:0% +Olympic Games Olympic games are tempor +events in cities they've been used for + + align:start position:0% +events in cities they've been used for + + + align:start position:0% +events in cities they've been used for +cities like Tokyo to argue for building + + align:start position:0% +cities like Tokyo to argue for building + + + align:start position:0% +cities like Tokyo to argue for building +a freeway system for building new + + align:start position:0% +a freeway system for building new + + + align:start position:0% +a freeway system for building new +housing they've been all been used by + + align:start position:0% +housing they've been all been used by + + + align:start position:0% +housing they've been all been used by +countries like contemporary China Tokyo + + align:start position:0% +countries like contemporary China Tokyo + + + align:start position:0% +countries like contemporary China Tokyo +in 1960 Melbourne in 56 to introduce the + + align:start position:0% +in 1960 Melbourne in 56 to introduce the + + + align:start position:0% +in 1960 Melbourne in 56 to introduce the +city as an as a + + align:start position:0% +city as an as a + + + align:start position:0% +city as an as a +international important place for trade + + align:start position:0% +international important place for trade + + + align:start position:0% +international important place for trade +for + + align:start position:0% +for + + + align:start position:0% +for +psychological satisfaction and so on Los + + align:start position:0% +psychological satisfaction and so on Los + + + align:start position:0% +psychological satisfaction and so on Los +Angeles and the + + align:start position:0% +Angeles and the + + + align:start position:0% +Angeles and the +American Exposition Olympic Games at + + align:start position:0% +American Exposition Olympic Games at + + + align:start position:0% +American Exposition Olympic Games at +olymp at Atlanta and Los Angeles have + + align:start position:0% +olymp at Atlanta and Los Angeles have + + + align:start position:0% +olymp at Atlanta and Los Angeles have +argued that you can use reuse existing + + align:start position:0% + + + + align:start position:0% + +infrastructure that you can capitalize + + align:start position:0% +infrastructure that you can capitalize + + + align:start position:0% +infrastructure that you can capitalize +on the existing resources in already in + + align:start position:0% +on the existing resources in already in + + + align:start position:0% +on the existing resources in already in +the city the 84 games builds no new + + align:start position:0% +the city the 84 games builds no new + + + align:start position:0% +the city the 84 games builds no new +housing the Olympic Village is based on + + align:start position:0% +housing the Olympic Village is based on + + + align:start position:0% +housing the Olympic Village is based on +campus housing in in the University of + + align:start position:0% +campus housing in in the University of + + + align:start position:0% +campus housing in in the University of +Southern California the only build + + align:start position:0% +Southern California the only build + + + align:start position:0% +Southern California the only build +building the only new facility built in + + align:start position:0% +building the only new facility built in + + + align:start position:0% +building the only new facility built in +' 84 is the swimming pool paid for by + + align:start position:0% +' 84 is the swimming pool paid for by + + + align:start position:0% +' 84 is the swimming pool paid for by +McDonald's so there's not only a notion + + align:start position:0% +McDonald's so there's not only a notion + + + align:start position:0% +McDonald's so there's not only a notion +of the private sector playing a role + + align:start position:0% +of the private sector playing a role + + + align:start position:0% +of the private sector playing a role +which the ioc which is a semi + + align:start position:0% +which the ioc which is a semi + + + align:start position:0% +which the ioc which is a semi +fascist organization corrupt as + + align:start position:0% +fascist organization corrupt as + + + align:start position:0% +fascist organization corrupt as +hell + + align:start position:0% +hell + + + align:start position:0% +hell +uh + + align:start position:0% +uh + + + align:start position:0% +uh +controlling the + + align:start position:0% +controlling the + + + align:start position:0% +controlling the +franchise + + align:start position:0% + + + + align:start position:0% + +the Los Angeles games is widespread + + align:start position:0% +the Los Angeles games is widespread + + + align:start position:0% +the Los Angeles games is widespread +distributed according to the plan of the + + align:start position:0% +distributed according to the plan of the + + + align:start position:0% +distributed according to the plan of the +town the games in the in + + align:start position:0% +town the games in the in + + + align:start position:0% +town the games in the in +Barcelona are also very tightly + + align:start position:0% +Barcelona are also very tightly + + + align:start position:0% +Barcelona are also very tightly +associated with the major form of the + + align:start position:0% +associated with the major form of the + + + align:start position:0% +associated with the major form of the +city the + + align:start position:0% +city the + + + align:start position:0% +city the +anange + + align:start position:0% +anange + + + align:start position:0% +anange +next just the + + align:start position:0% +next just the + + + align:start position:0% +next just the +Olympic 1928 on the right the American + + align:start position:0% +Olympic 1928 on the right the American + + + align:start position:0% +Olympic 1928 on the right the American +team is housed in a + + align:start position:0% +team is housed in a + + + align:start position:0% +team is housed in a +boat the + + align:start position:0% +boat the + + + align:start position:0% +boat the +ultimate Emeral + + align:start position:0% +ultimate Emeral + + + align:start position:0% +ultimate Emeral +item this is Cape Town I was going to + + align:start position:0% +item this is Cape Town I was going to + + + align:start position:0% +item this is Cape Town I was going to +talk about Cape Town's attempt to use + + align:start position:0% +talk about Cape Town's attempt to use + + + align:start position:0% +talk about Cape Town's attempt to use +racial integration as a social basis for + + align:start position:0% +racial integration as a social basis for + + + align:start position:0% +racial integration as a social basis for +the plan of the Olympic Games they never + + align:start position:0% +the plan of the Olympic Games they never + + + align:start position:0% +the plan of the Olympic Games they never +got they never entered + + align:start position:0% +got they never entered + + + align:start position:0% +got they never entered +next and the the project for the Olympic + + align:start position:0% +next and the the project for the Olympic + + + align:start position:0% +next and the the project for the Olympic +Games in Boston re using the river and + + align:start position:0% +Games in Boston re using the river and + + + align:start position:0% +Games in Boston re using the river and +the university facilities along the + + align:start position:0% +the university facilities along the + + + align:start position:0% +the university facilities along the +river is the core and he has an + + align:start position:0% +river is the core and he has an + + + align:start position:0% +river is the core and he has an +indication of how much the games cost + + align:start position:0% +indication of how much the games cost + + + align:start position:0% +indication of how much the games cost +and the division between the private and + + align:start position:0% +and the division between the private and + + + align:start position:0% +and the division between the private and +public + + align:start position:0% + + + + align:start position:0% + +sector \ No newline at end of file diff --git a/4PkKI_S9TIQ.txt b/4PkKI_S9TIQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..7ed7ecb5ed3b3c2c76af4857503a798f97a9c1ef --- /dev/null +++ b/4PkKI_S9TIQ.txt @@ -0,0 +1,228 @@ +Let's wrap up our discussion of system-level +interconnect by considering how best to connect + +N components that need to send messages to +one another, e.g., CPUs on a multicore chip. + +Today such chips have a handful of cores, +but soon they may have 100s or 1000s of cores. + +We'll build our communications network using +point-to-point links. + +In our analysis, each point-to-point link +is counted at a cost of 1 hardware unit. + +Sending a message across a link requires one +time unit. + +And we'll assume that different links can +operate in parallel, so more links will mean + +more message traffic. + +We'll do an asymptotic analysis of the throughput +(total messages per unit time), latency (worst-case + +time to deliver a single message), and hardware +cost. + +In other words, we'll make a rough estimate +how these quantities change as N grows. + +Note that in general the throughput and hardware +cost are proportional to the number of point-to-point + +links. + +Our baseline is the backplane bus discussed +earlier, where all the components share a + +single communication channel. + +With only a single channel, bus throughput +is 1 message per unit time and a message can + +travel between any two components in one time +unit. + +Since each component has to have an interface +to the shared channel, the total hardware + +cost is O(n). + +In a ring network each component sends its +messages to a single neighbor and the links + +are arranged so that its possible to reach +all components. + +There are N links in total, so the throughput +and cost are both O(n). + +The worst case latency is also O(n) since +a message might have to travel across N-1 + +links to reach the neighbor that's immediately +upstream. + +Ring topologies are useful when message latency +isn't important or when most messages are + +to the component that's immediately downstream, +i.e., the components form a processing pipeline. + +The most general network topology is when +every component has a direct link to every + +other component. + +There are O(N**2) links so the throughput +and cost are both O(N**2). + +And the latency is 1 time unit since each +destination is directly accessible. + +Although expensive, complete graphs offer +very high throughput with very low latencies. + +A variant of the complete graph is the crossbar +switch where a particular row and column can + +be connected to form a link between particular +A and B components + +with the restriction that each row and each +column can only carry 1 message during each + +time unit. + +Assume that the first row and first column +connect to the same component, and so on, + +i.e., that the example crossbar switch is +being used to connect 4 components. + +Then there are O(n) messages delivered each +time unit, with a latency of 1. + +There are N**2 switches in the crossbar, so +the cost is O(N**2) even though there are + +only O(n) links. + +In mesh networks, components are connected +to some fixed number of neighboring components, + +in either 2 or 3 dimensions. + +Hence the total number of links is proportional +to the number of components, so both throughput + +and cost are O(n). + +The worst-case latencies for mesh networks +are proportional to length of the sides, so + +the latency is O(sqrt n) for 2D meshes and +O(cube root n) for 3D meshes. + +The orderly layout, constant per-node hardware +costs, and modest worst-case latency make + +2D 4-neighbor meshes a popular choice for +the current generation of experimental multi-core + +processors. + +Hypercube and tree networks offer logarithmic +latencies, which for large N may be faster + +than mesh networks. + +The original CM-1 Connection Machine designed +in the 80's used a hypercube network to connect + +up to 65,536 very simple processors, each +connected to 16 neighbors. + +Later generations incorporated smaller numbers +of more sophisticated processors, still connected + +by a hypercube network. + +In the early 90's the last generation of Connection +Machines used a tree network, with the clever + +innovation that the links towards the root +of the tree had a higher message capacity. + +Here's a summary of the theoretical latencies +we calculated for the various topologies. + +As a reality check, it's important to realize +that the lower bound on the worst-case distance + +between components in our 3-dimensional world +is O(cube root of N). + +In the case of a 2D layout, the worst-case +distance is O(sqrt N). + +Since we know that the time to transmit a +message is proportional to the distance traveled, + +we should modify our latency calculations +to reflect this physical constraint. + +Note that the bus and crossbar involve N connections +to a single link, so here the lower-bound + +on the latency needs to reflect the capacitive +load added by each connection. + +The winner? + +Mesh networks avoid the need for longer wires +as the number of connected components grows + +and appear to be an attractive alternative +for high-capacity communication networks connecting + +1000's of processors. + +Summarizing our discussion: +point-to-point links are in common use today + +for system-level interconnect, and as a result +our systems are faster, more reliable, more + +energy-efficient and smaller than ever before. + +Multi-signal parallel buses are still used +for very-high-bandwidth connections to memories, + +with a lot of very careful engineering to +avoid the electrical problems observed in + +earlier bus implementations. + +Wireless connections are in common use to +connect mobile devices to nearby components + +and there has been interesting work on how +to allow mobile devices to discover what peripherals + +are nearby and enable them to connect automatically. + +The upcoming generation of multi-core chips +will have 10's to 100's of processing cores. + +There is a lot ongoing research to determine +which communication topology would offer the + +best combination of high communication bandwidth +and low latency. + +The next ten years will be an interesting +time for on-chip network engineers! \ No newline at end of file diff --git a/4RSQTqPjOLw.txt b/4RSQTqPjOLw.txt new file mode 100644 index 0000000000000000000000000000000000000000..6508b2dc9777e90f128270a20b3c9652b7a53bd8 --- /dev/null +++ b/4RSQTqPjOLw.txt @@ -0,0 +1,9339 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so welcome to our special class with + + align:start position:0% +so welcome to our special class with + + + align:start position:0% +so welcome to our special class with +half people going for Thanksgiving you + + align:start position:0% +half people going for Thanksgiving you + + + align:start position:0% +half people going for Thanksgiving you +guys are the chosen few so pleased + + align:start position:0% +guys are the chosen few so pleased + + + align:start position:0% +guys are the chosen few so pleased +you're here so I'm just gonna see a + + align:start position:0% +you're here so I'm just gonna see a + + + align:start position:0% +you're here so I'm just gonna see a +little bit about models versus data and + + align:start position:0% +little bit about models versus data and + + + align:start position:0% +little bit about models versus data and +then I'm going to talk about go back to + + align:start position:0% +then I'm going to talk about go back to + + + align:start position:0% +then I'm going to talk about go back to +boundary value problems and talk a + + align:start position:0% +boundary value problems and talk a + + + align:start position:0% +boundary value problems and talk a +little bit about how you handle really + + align:start position:0% +little bit about how you handle really + + + align:start position:0% +little bit about how you handle really +big ones yeah yeah yes and in fact these + + align:start position:0% +big ones yeah yeah yes and in fact these + + + align:start position:0% +big ones yeah yeah yes and in fact these +are even going to be on the video + + align:start position:0% +are even going to be on the video + + + align:start position:0% +are even going to be on the video +because they guide just fix the video so + + align:start position:0% +because they guide just fix the video so + + + align:start position:0% +because they guide just fix the video so +it'll be recorded all right um yeah I'm + + align:start position:0% +it'll be recorded all right um yeah I'm + + + align:start position:0% +it'll be recorded all right um yeah I'm +sorry you said the video was broken last + + align:start position:0% +sorry you said the video was broken last + + + align:start position:0% +sorry you said the video was broken last +time so the recording didn't work all + + align:start position:0% +time so the recording didn't work all + + + align:start position:0% +time so the recording didn't work all +right + + align:start position:0% +right + + + align:start position:0% +right +so when we're talking about models + + align:start position:0% +so when we're talking about models + + + align:start position:0% +so when we're talking about models +versus data a really critical question + + align:start position:0% +versus data a really critical question + + + align:start position:0% +versus data a really critical question +is whether the model is really + + align:start position:0% +is whether the model is really + + + align:start position:0% +is whether the model is really +consistent in the data or not and how do + + align:start position:0% +consistent in the data or not and how do + + + align:start position:0% +consistent in the data or not and how do +we know this is really true + + align:start position:0% +we know this is really true + + + align:start position:0% +we know this is really true +so we talked about how we can figure out + + align:start position:0% +so we talked about how we can figure out + + + align:start position:0% +so we talked about how we can figure out +some sort of chi-squared maximum that we + + align:start position:0% +some sort of chi-squared maximum that we + + + align:start position:0% +some sort of chi-squared maximum that we +would tolerate so maximum we tolerate we + + align:start position:0% +would tolerate so maximum we tolerate we + + + align:start position:0% +would tolerate so maximum we tolerate we +call it Q capital Q and the lecture + + align:start position:0% +call it Q capital Q and the lecture + + + align:start position:0% +call it Q capital Q and the lecture +before and so we think if we can find + + align:start position:0% +before and so we think if we can find + + + align:start position:0% +before and so we think if we can find +out a chi squared of theta that's less + + align:start position:0% +out a chi squared of theta that's less + + + align:start position:0% +out a chi squared of theta that's less +than this then it's at least plausible + + align:start position:0% +than this then it's at least plausible + + + align:start position:0% +than this then it's at least plausible +that our models true right we're + + align:start position:0% +that our models true right we're + + + align:start position:0% +that our models true right we're +alternatively if all chi squared the + + align:start position:0% +alternatively if all chi squared the + + + align:start position:0% +alternatively if all chi squared the +state is for any value of Thetas are + + align:start position:0% +state is for any value of Thetas are + + + align:start position:0% +state is for any value of Thetas are +greater than Phi squared max then then + + align:start position:0% +greater than Phi squared max then then + + + align:start position:0% +greater than Phi squared max then then +we would say the model is false or + + align:start position:0% +we would say the model is false or + + + align:start position:0% +we would say the model is false or +something else is really wrong with our + + align:start position:0% +something else is really wrong with our + + + align:start position:0% +something else is really wrong with our +experiment right that's that's so that's + + align:start position:0% +experiment right that's that's so that's + + + align:start position:0% +experiment right that's that's so that's +what we say when we saying we have a + + align:start position:0% +what we say when we saying we have a + + + align:start position:0% +what we say when we saying we have a +maximum PI squared that we would + + align:start position:0% +maximum PI squared that we would + + + align:start position:0% +maximum PI squared that we would +tolerate so a critical question with + + align:start position:0% +tolerate so a critical question with + + + align:start position:0% +tolerate so a critical question with +this is whether we really found the very + + align:start position:0% +this is whether we really found the very + + + align:start position:0% +this is whether we really found the very +best fit value of the parameters in in + + align:start position:0% +best fit value of the parameters in in + + + align:start position:0% +best fit value of the parameters in in +some simple + + align:start position:0% +some simple + + + align:start position:0% +some simple +problems you might have linear + + align:start position:0% +problems you might have linear + + + align:start position:0% +problems you might have linear +dependence of the parameters and then + + align:start position:0% +dependence of the parameters and then + + + align:start position:0% +dependence of the parameters and then +there's only one best fit usually as + + align:start position:0% +there's only one best fit usually as + + + align:start position:0% +there's only one best fit usually as +long as you have a non singular set of + + align:start position:0% +long as you have a non singular set of + + + align:start position:0% +long as you have a non singular set of +equations and every one we find there's + + align:start position:0% +equations and every one we find there's + + + align:start position:0% +equations and every one we find there's +no trouble however more commonly you + + align:start position:0% +no trouble however more commonly you + + + align:start position:0% +no trouble however more commonly you +have equations which are singular or + + align:start position:0% +have equations which are singular or + + + align:start position:0% +have equations which are singular or +close to singular and also you normally + + align:start position:0% +close to singular and also you normally + + + align:start position:0% +close to singular and also you normally +have nonlinear dependence between the + + align:start position:0% +have nonlinear dependence between the + + + align:start position:0% +have nonlinear dependence between the +model predictions and the parameters so + + align:start position:0% +model predictions and the parameters so + + + align:start position:0% +model predictions and the parameters so +for example I do kinetics we always care + + align:start position:0% +for example I do kinetics we always care + + + align:start position:0% +for example I do kinetics we always care +about the rate coefficients the case and + + align:start position:0% +about the rate coefficients the case and + + + align:start position:0% +about the rate coefficients the case and +they always come in inside a + + align:start position:0% +they always come in inside a + + + align:start position:0% +they always come in inside a +differential equation right you always + + align:start position:0% +differential equation right you always + + + align:start position:0% +differential equation right you always +have like D concentrations DT is even + + align:start position:0% +have like D concentrations DT is even + + + align:start position:0% +have like D concentrations DT is even +some terms and some of them are you know + + align:start position:0% +some terms and some of them are you know + + + align:start position:0% +some terms and some of them are you know +K concentration I times concentration J + + align:start position:0% +K concentration I times concentration J + + + align:start position:0% +K concentration I times concentration J +whatever one is it okay right you have a + + align:start position:0% +whatever one is it okay right you have a + + + align:start position:0% +whatever one is it okay right you have a +lot of like terms like this by molecular + + align:start position:0% +lot of like terms like this by molecular + + + align:start position:0% +lot of like terms like this by molecular +reaction terms and these K some of them + + align:start position:0% +reaction terms and these K some of them + + + align:start position:0% +reaction terms and these K some of them +I don't know and so these are these + + align:start position:0% +I don't know and so these are these + + + align:start position:0% +I don't know and so these are these +would be one of my Thetas so this video + + align:start position:0% +would be one of my Thetas so this video + + + align:start position:0% +would be one of my Thetas so this video +say 217 would be one of these case I + + align:start position:0% +say 217 would be one of these case I + + + align:start position:0% +say 217 would be one of these case I +wanted to determine and when I have a + + align:start position:0% +wanted to determine and when I have a + + + align:start position:0% +wanted to determine and when I have a +differential equation like this when I + + align:start position:0% +differential equation like this when I + + + align:start position:0% +differential equation like this when I +integrate it the K is always going to + + align:start position:0% +integrate it the K is always going to + + + align:start position:0% +integrate it the K is always going to +come in nonlinearly in the in the + + align:start position:0% +come in nonlinearly in the in the + + + align:start position:0% +come in nonlinearly in the in the +solution right so what I want to + + align:start position:0% +solution right so what I want to + + + align:start position:0% +solution right so what I want to +integrate this solution even in the + + align:start position:0% +integrate this solution even in the + + + align:start position:0% +integrate this solution even in the +simplest case you get things like C of T + + align:start position:0% +simplest case you get things like C of T + + + align:start position:0% +simplest case you get things like C of T +is equal to a e to the negative KT that + + align:start position:0% +is equal to a e to the negative KT that + + + align:start position:0% +is equal to a e to the negative KT that +might be really super simple case if you + + align:start position:0% +might be really super simple case if you + + + align:start position:0% +might be really super simple case if you +have a linear kinetics the K is still + + align:start position:0% +have a linear kinetics the K is still + + + align:start position:0% +have a linear kinetics the K is still +coming in nonlinearly to the predictions + + align:start position:0% +coming in nonlinearly to the predictions + + + align:start position:0% +coming in nonlinearly to the predictions +right and if you have anything + + align:start position:0% +right and if you have anything + + + align:start position:0% +right and if you have anything +complicated you can't even write it down + + align:start position:0% +complicated you can't even write it down + + + align:start position:0% +complicated you can't even write it down +the closed form expression and you have + + align:start position:0% +the closed form expression and you have + + + align:start position:0% +the closed form expression and you have +to integrate with in with a OD 45 or OD + + align:start position:0% +to integrate with in with a OD 45 or OD + + + align:start position:0% +to integrate with in with a OD 45 or OD +1 5s and so the relationship between K + + align:start position:0% +1 5s and so the relationship between K + + + align:start position:0% +1 5s and so the relationship between K +and they and the concentrations that + + align:start position:0% +and they and the concentrations that + + + align:start position:0% +and they and the concentrations that +you've measure can be really complicated + + align:start position:0% +you've measure can be really complicated + + + align:start position:0% +you've measure can be really complicated +so it's always nonlinear am I in a mile + + align:start position:0% +so it's always nonlinear am I in a mile + + + align:start position:0% +so it's always nonlinear am I in a mile +up in my world everything all models are + + align:start position:0% +up in my world everything all models are + + + align:start position:0% +up in my world everything all models are +nonlinear and and I think there's many + + align:start position:0% +nonlinear and and I think there's many + + + align:start position:0% +nonlinear and and I think there's many +other situations like that so if you do + + align:start position:0% +other situations like that so if you do + + + align:start position:0% +other situations like that so if you do +trying to measure a diffusivity you it + + align:start position:0% +trying to measure a diffusivity you it + + + align:start position:0% +trying to measure a diffusivity you it +might be possible to seven experiment + + align:start position:0% +might be possible to seven experiment + + + align:start position:0% +might be possible to seven experiment +where you'd expect a linear dependence + + align:start position:0% +where you'd expect a linear dependence + + + align:start position:0% +where you'd expect a linear dependence +due to something you'd measure in the + + align:start position:0% +due to something you'd measure in the + + + align:start position:0% +due to something you'd measure in the +diffusivity but most likely not + + align:start position:0% +diffusivity but most likely not + + + align:start position:0% +diffusivity but most likely not +so most likely it would come and + + align:start position:0% +so most likely it would come and + + + align:start position:0% +so most likely it would come and +unlimitedly somehow and you'd have to + + align:start position:0% +unlimitedly somehow and you'd have to + + + align:start position:0% +unlimitedly somehow and you'd have to +you'd have some model for it and you'd + + align:start position:0% +you'd have some model for it and you'd + + + align:start position:0% +you'd have some model for it and you'd +have nonlinear dependence between that + + align:start position:0% +have nonlinear dependence between that + + + align:start position:0% +have nonlinear dependence between that +number and the numbers you would measure + + align:start position:0% +number and the numbers you would measure + + + align:start position:0% +number and the numbers you would measure +right and almost all the properties or + + align:start position:0% +right and almost all the properties or + + + align:start position:0% +right and almost all the properties or +like that so because you have a + + align:start position:0% +like that so because you have a + + + align:start position:0% +like that so because you have a +nonlinear dependence then you have to + + align:start position:0% +nonlinear dependence then you have to + + + align:start position:0% +nonlinear dependence then you have to +worry about how many minima do you have + + align:start position:0% +worry about how many minima do you have + + + align:start position:0% +worry about how many minima do you have +in your surface so Chi squared of theta + + align:start position:0% +in your surface so Chi squared of theta + + + align:start position:0% +in your surface so Chi squared of theta +is a nonlinear function of a lot of + + align:start position:0% +is a nonlinear function of a lot of + + + align:start position:0% +is a nonlinear function of a lot of +variables and typically it won't just + + align:start position:0% +variables and typically it won't just + + + align:start position:0% +variables and typically it won't just +have one minimum it'll have a whole lot + + align:start position:0% +have one minimum it'll have a whole lot + + + align:start position:0% +have one minimum it'll have a whole lot +of local minima now one of those is a + + align:start position:0% +of local minima now one of those is a + + + align:start position:0% +of local minima now one of those is a +global minimum and that's the one you + + align:start position:0% +global minimum and that's the one you + + + align:start position:0% +global minimum and that's the one you +sort of want that's the very best + + align:start position:0% +sort of want that's the very best + + + align:start position:0% +sort of want that's the very best +possible fit but you normally won't know + + align:start position:0% +possible fit but you normally won't know + + + align:start position:0% +possible fit but you normally won't know +how many minimum it has and so no matter + + align:start position:0% +how many minimum it has and so no matter + + + align:start position:0% +how many minimum it has and so no matter +how many minima you find you don't know + + align:start position:0% +how many minima you find you don't know + + + align:start position:0% +how many minima you find you don't know +if you're done and you don't know if you + + align:start position:0% +if you're done and you don't know if you + + + align:start position:0% +if you're done and you don't know if you +don't have you really found the best fit + + align:start position:0% +don't have you really found the best fit + + + align:start position:0% +don't have you really found the best fit +okay so just because all the ones you + + align:start position:0% +okay so just because all the ones you + + + align:start position:0% +okay so just because all the ones you +found so far are bigger than chi squared + + align:start position:0% +found so far are bigger than chi squared + + + align:start position:0% +found so far are bigger than chi squared +max you might not be ready to write that + + align:start position:0% +max you might not be ready to write that + + + align:start position:0% +max you might not be ready to write that +article to nature to claim the gloss of + + align:start position:0% +article to nature to claim the gloss of + + + align:start position:0% +article to nature to claim the gloss of +physics are incorrect + + align:start position:0% +physics are incorrect + + + align:start position:0% +physics are incorrect +because you're not sure you really found + + align:start position:0% +because you're not sure you really found + + + align:start position:0% +because you're not sure you really found +the very best fit okay so that's one of + + align:start position:0% +the very best fit okay so that's one of + + + align:start position:0% +the very best fit okay so that's one of +the many problems of trying to figure + + align:start position:0% +the many problems of trying to figure + + + align:start position:0% +the many problems of trying to figure +out if a model and data are really + + align:start position:0% +out if a model and data are really + + + align:start position:0% +out if a model and data are really +consistent now that particular one you + + align:start position:0% +consistent now that particular one you + + + align:start position:0% +consistent now that particular one you +can overcome if you can find a + + align:start position:0% +can overcome if you can find a + + + align:start position:0% +can overcome if you can find a +guaranteed way to find a global optimum + + align:start position:0% +guaranteed way to find a global optimum + + + align:start position:0% +guaranteed way to find a global optimum +to find the very best possible fit there + + align:start position:0% +to find the very best possible fit there + + + align:start position:0% +to find the very best possible fit there +is and some people spend their life + + align:start position:0% +is and some people spend their life + + + align:start position:0% +is and some people spend their life +working on this and one of those people + + align:start position:0% +working on this and one of those people + + + align:start position:0% +working on this and one of those people +is professor Barton in this department + + align:start position:0% +is professor Barton in this department + + + align:start position:0% +is professor Barton in this department +and so he teaches a class how to do this + + align:start position:0% +and so he teaches a class how to do this + + + align:start position:0% +and so he teaches a class how to do this +and there are actually methods to do it + + align:start position:0% +and there are actually methods to do it + + + align:start position:0% +and there are actually methods to do it +so if you want to see the application of + + align:start position:0% +so if you want to see the application of + + + align:start position:0% +so if you want to see the application of +this to kinetic models there's paper by + + align:start position:0% +this to kinetic models there's paper by + + + align:start position:0% +this to kinetic models there's paper by +by me and professor Barton and the lead + + align:start position:0% +by me and professor Barton and the lead + + + align:start position:0% +by me and professor Barton and the lead +author is one of his former students + + align:start position:0% +author is one of his former students + + + align:start position:0% +author is one of his former students +Adam singer and j phys chem and it just + + align:start position:0% +Adam singer and j phys chem and it just + + + align:start position:0% +Adam singer and j phys chem and it just +shows how you can use global + + align:start position:0% +shows how you can use global + + + align:start position:0% +shows how you can use global +optimization to guarantee you have the + + align:start position:0% +optimization to guarantee you have the + + + align:start position:0% +optimization to guarantee you have the +very best possible values the parameters + + align:start position:0% +very best possible values the parameters + + + align:start position:0% +very best possible values the parameters +and then I'll show you what happened so + + align:start position:0% +and then I'll show you what happened so + + + align:start position:0% +and then I'll show you what happened so +this is a case where the experimental + + align:start position:0% +this is a case where the experimental + + + align:start position:0% +this is a case where the experimental +data was measured by one of my students + + align:start position:0% +data was measured by one of my students + + + align:start position:0% +data was measured by one of my students +James Taylor and that's the things with + + align:start position:0% +James Taylor and that's the things with + + + align:start position:0% +James Taylor and that's the things with +the error bars and he did a lot of hard + + align:start position:0% +the error bars and he did a lot of hard + + + align:start position:0% +the error bars and he did a lot of hard +work to make sure he had pretty good + + align:start position:0% +work to make sure he had pretty good + + + align:start position:0% +work to make sure he had pretty good +error bars he really knew what they were + + align:start position:0% +error bars he really knew what they were + + + align:start position:0% +error bars he really knew what they were +and so he had those points so he + + align:start position:0% +and so he had those points so he + + + align:start position:0% +and so he had those points so he +measured a lot of points this measure + + align:start position:0% +measured a lot of points this measure + + + align:start position:0% +measured a lot of points this measure +him a lot of points is a key thing so it + + align:start position:0% +him a lot of points is a key thing so it + + + align:start position:0% +him a lot of points is a key thing so it +means his decrees of freedom is very + + align:start position:0% +means his decrees of freedom is very + + + align:start position:0% +means his decrees of freedom is very +large because he's many many different + + align:start position:0% +large because he's many many different + + + align:start position:0% +large because he's many many different +time points along the way there and he + + align:start position:0% +time points along the way there and he + + + align:start position:0% +time points along the way there and he +has error bars in all of them + + align:start position:0% +has error bars in all of them + + + align:start position:0% +has error bars in all of them +and so because the degrees of freedom + + align:start position:0% +and so because the degrees of freedom + + + align:start position:0% +and so because the degrees of freedom +are very large it actually makes it a + + align:start position:0% +are very large it actually makes it a + + + align:start position:0% +are very large it actually makes it a +very good constraint on on the model it + + align:start position:0% +very good constraint on on the model it + + + align:start position:0% +very good constraint on on the model it +tests it very thoroughly where if you + + align:start position:0% +tests it very thoroughly where if you + + + align:start position:0% +tests it very thoroughly where if you +only measured one point then that's not + + align:start position:0% +only measured one point then that's not + + + align:start position:0% +only measured one point then that's not +a very good constraint now what James + + align:start position:0% +a very good constraint now what James + + + align:start position:0% +a very good constraint now what James +had done and we published a paper in + + align:start position:0% +had done and we published a paper in + + + align:start position:0% +had done and we published a paper in +2004 where he did it where he said you + + align:start position:0% +2004 where he did it where he said you + + + align:start position:0% +2004 where he did it where he said you +know when I do my fits this is what I + + align:start position:0% +know when I do my fits this is what I + + + align:start position:0% +know when I do my fits this is what I +get I get these kind of purple and green + + align:start position:0% +get I get these kind of purple and green + + + align:start position:0% +get I get these kind of purple and green +things and therefore they're all outside + + align:start position:0% +things and therefore they're all outside + + + align:start position:0% +things and therefore they're all outside +the error bars and therefore I published + + align:start position:0% +the error bars and therefore I published + + + align:start position:0% +the error bars and therefore I published +in the journal physical chemistry I + + align:start position:0% +in the journal physical chemistry I + + + align:start position:0% +in the journal physical chemistry I +claim this model is wrong based on my + + align:start position:0% +claim this model is wrong based on my + + + align:start position:0% +claim this model is wrong based on my +experimental data okay so we published + + align:start position:0% +experimental data okay so we published + + + align:start position:0% +experimental data okay so we published +that 2004 was accepted by the referees + + align:start position:0% +that 2004 was accepted by the referees + + + align:start position:0% +that 2004 was accepted by the referees +it's in the literature you can read it + + align:start position:0% +it's in the literature you can read it + + + align:start position:0% +it's in the literature you can read it +don't believe it though because Adam + + align:start position:0% +don't believe it though because Adam + + + align:start position:0% +don't believe it though because Adam +singer went back into global + + align:start position:0% +singer went back into global + + + align:start position:0% +singer went back into global +optimization using the same model and + + align:start position:0% +optimization using the same model and + + + align:start position:0% +optimization using the same model and +his red line goes right through all the + + align:start position:0% +his red line goes right through all the + + + align:start position:0% +his red line goes right through all the +points really well do you see that I've + + align:start position:0% +points really well do you see that I've + + + align:start position:0% +points really well do you see that I've +you see the red line there this red red + + align:start position:0% +you see the red line there this red red + + + align:start position:0% +you see the red line there this red red +curve that's the true best fit and so + + align:start position:0% +curve that's the true best fit and so + + + align:start position:0% +curve that's the true best fit and so +although the fits that James had found + + align:start position:0% +although the fits that James had found + + + align:start position:0% +although the fits that James had found +were all local minima and the + + align:start position:0% +were all local minima and the + + + align:start position:0% +were all local minima and the +chi-squared surface and when he actually + + align:start position:0% +chi-squared surface and when he actually + + + align:start position:0% +chi-squared surface and when he actually +found the really the best fit with Adams + + align:start position:0% +found the really the best fit with Adams + + + align:start position:0% +found the really the best fit with Adams +fancy method then it turns out that + + align:start position:0% +fancy method then it turns out that + + + align:start position:0% +fancy method then it turns out that +actually model matches the data like + + align:start position:0% +actually model matches the data like + + + align:start position:0% +actually model matches the data like +perfectly so that's definitely true so + + align:start position:0% +perfectly so that's definitely true so + + + align:start position:0% +perfectly so that's definitely true so +what we could publish the first time was + + align:start position:0% +what we could publish the first time was + + + align:start position:0% +what we could publish the first time was +completely wrong because we said the + + align:start position:0% +completely wrong because we said the + + + align:start position:0% +completely wrong because we said the +model disproved the data but in fact the + + align:start position:0% +model disproved the data but in fact the + + + align:start position:0% +model disproved the data but in fact the +model proved the data I mean the data + + align:start position:0% +model proved the data I mean the data + + + align:start position:0% +model proved the data I mean the data +prove the model or was completely + + align:start position:0% +prove the model or was completely + + + align:start position:0% +prove the model or was completely +consistent in the model in every way in + + align:start position:0% +consistent in the model in every way in + + + align:start position:0% +consistent in the model in every way in +great detail so so I was all embarrassed + + align:start position:0% +great detail so so I was all embarrassed + + + align:start position:0% +great detail so so I was all embarrassed +so then James also in the same paper had + + align:start position:0% +so then James also in the same paper had + + + align:start position:0% +so then James also in the same paper had +found and they could measure another + + align:start position:0% +found and they could measure another + + + align:start position:0% +found and they could measure another +condition a different a different + + align:start position:0% +condition a different a different + + + align:start position:0% +condition a different a different +slightly different case and actually was + + align:start position:0% +slightly different case and actually was + + + align:start position:0% +slightly different case and actually was +looking a different solvent and in this + + align:start position:0% +looking a different solvent and in this + + + align:start position:0% +looking a different solvent and in this +case he found this green curve is his + + align:start position:0% +case he found this green curve is his + + + align:start position:0% +case he found this green curve is his +best fit and it looked pretty good by I + + align:start position:0% +best fit and it looked pretty good by I + + + align:start position:0% +best fit and it looked pretty good by I +though you can see it's sort of + + align:start position:0% +though you can see it's sort of + + + align:start position:0% +though you can see it's sort of +skittering on the tops of the Erb are + + align:start position:0% +skittering on the tops of the Erb are + + + align:start position:0% +skittering on the tops of the Erb are +bands and so this is one where he said + + align:start position:0% +bands and so this is one where he said + + + align:start position:0% +bands and so this is one where he said +you know we do the statistical test + + align:start position:0% +you know we do the statistical test + + + align:start position:0% +you know we do the statistical test +there's like a 5% chance that you would + + align:start position:0% +there's like a 5% chance that you would + + + align:start position:0% +there's like a 5% chance that you would +measure data like he measured if that + + align:start position:0% +measure data like he measured if that + + + align:start position:0% +measure data like he measured if that +green model was the truth + + align:start position:0% +green model was the truth + + + align:start position:0% +green model was the truth +and so we said some wishy-washy words in + + align:start position:0% +and so we said some wishy-washy words in + + + align:start position:0% +and so we said some wishy-washy words in +the paper basically as we weren't really + + align:start position:0% +the paper basically as we weren't really + + + align:start position:0% +the paper basically as we weren't really +sure if it was giving it was consistent + + align:start position:0% +sure if it was giving it was consistent + + + align:start position:0% +sure if it was giving it was consistent +or not consistent with the data but in + + align:start position:0% +or not consistent with the data but in + + + align:start position:0% +or not consistent with the data but in +that case Adam used his fancy global + + align:start position:0% +that case Adam used his fancy global + + + align:start position:0% +that case Adam used his fancy global +optimization techniques I found that + + align:start position:0% +optimization techniques I found that + + + align:start position:0% +optimization techniques I found that +James is it was actually not that far + + align:start position:0% +James is it was actually not that far + + + align:start position:0% +James is it was actually not that far +from the global optimum and he got the + + align:start position:0% +from the global optimum and he got the + + + align:start position:0% +from the global optimum and he got the +red curve there marked by the red arrow + + align:start position:0% +red curve there marked by the red arrow + + + align:start position:0% +red curve there marked by the red arrow +and that one it looks pretty good it + + align:start position:0% +and that one it looks pretty good it + + + align:start position:0% +and that one it looks pretty good it +actually likes when he goes through the + + align:start position:0% +actually likes when he goes through the + + + align:start position:0% +actually likes when he goes through the +data but it doesn't really do it right + + align:start position:0% +data but it doesn't really do it right + + + align:start position:0% +data but it doesn't really do it right +and found that you know it's the + + align:start position:0% +and found that you know it's the + + + align:start position:0% +and found that you know it's the +confidence intervals only 16% so it's + + align:start position:0% +confidence intervals only 16% so it's + + + align:start position:0% +confidence intervals only 16% so it's +only a 16% chance one chance out of six + + align:start position:0% +only a 16% chance one chance out of six + + + align:start position:0% +only a 16% chance one chance out of six +that James would have measured the data + + align:start position:0% +that James would have measured the data + + + align:start position:0% +that James would have measured the data +he measured if that model was true and + + align:start position:0% +he measured if that model was true and + + + align:start position:0% +he measured if that model was true and +now we're sure that we have the global + + align:start position:0% +now we're sure that we have the global + + + align:start position:0% +now we're sure that we have the global +best fit so now we're like thinking well + + align:start position:0% +best fit so now we're like thinking well + + + align:start position:0% +best fit so now we're like thinking well +you know maybe we should say that the + + align:start position:0% +you know maybe we should say that the + + + align:start position:0% +you know maybe we should say that the +model is not true for this case because + + align:start position:0% +model is not true for this case because + + + align:start position:0% +model is not true for this case because +is it eighty four percent chance it's + + align:start position:0% +is it eighty four percent chance it's + + + align:start position:0% +is it eighty four percent chance it's +not true anyway so so actually we got it + + align:start position:0% +not true anyway so so actually we got it + + + align:start position:0% +not true anyway so so actually we got it +wrong both ways so in the first case we + + align:start position:0% +wrong both ways so in the first case we + + + align:start position:0% +wrong both ways so in the first case we +said that our data disprove the model + + align:start position:0% +said that our data disprove the model + + + align:start position:0% +said that our data disprove the model +and in the second case we said that our + + align:start position:0% +and in the second case we said that our + + + align:start position:0% +and in the second case we said that our +model was pretty good with the data but + + align:start position:0% +model was pretty good with the data but + + + align:start position:0% +model was pretty good with the data but +actually they were both wrong so the one + + align:start position:0% +actually they were both wrong so the one + + + align:start position:0% +actually they were both wrong so the one +was wrong that actually the data did + + align:start position:0% +was wrong that actually the data did + + + align:start position:0% +was wrong that actually the data did +prove the model is correct for the first + + align:start position:0% +prove the model is correct for the first + + + align:start position:0% +prove the model is correct for the first +case and it actually looks looks a + + align:start position:0% +case and it actually looks looks a + + + align:start position:0% +case and it actually looks looks a +little fishy for this second case so + + align:start position:0% +little fishy for this second case so + + + align:start position:0% +little fishy for this second case so +anyway this is just a concrete example + + align:start position:0% +anyway this is just a concrete example + + + align:start position:0% +anyway this is just a concrete example +to make you be a little bit more worried + + align:start position:0% +to make you be a little bit more worried + + + align:start position:0% +to make you be a little bit more worried +about what you do when you do these + + align:start position:0% +about what you do when you do these + + + align:start position:0% +about what you do when you do these +fitting things now there's a variety of + + align:start position:0% +fitting things now there's a variety of + + + align:start position:0% +fitting things now there's a variety of +ways to try to do the least squares + + align:start position:0% +ways to try to do the least squares + + + align:start position:0% +ways to try to do the least squares +fitting to try to find Optima there was + + align:start position:0% +fitting to try to find Optima there was + + + align:start position:0% +fitting to try to find Optima there was +a guy named a car from University of + + align:start position:0% +a guy named a car from University of + + + align:start position:0% +a guy named a car from University of +Minnesota and he published a stochastic + + align:start position:0% +Minnesota and he published a stochastic + + + align:start position:0% +Minnesota and he published a stochastic +way to just try a whole lot of different + + align:start position:0% +way to just try a whole lot of different + + + align:start position:0% +way to just try a whole lot of different +initial guesses and that usually works + + align:start position:0% +initial guesses and that usually works + + + align:start position:0% +initial guesses and that usually works +to find the global minimum but if you + + align:start position:0% +to find the global minimum but if you + + + align:start position:0% +to find the global minimum but if you +really want to have a guaranteed global + + align:start position:0% +really want to have a guaranteed global + + + align:start position:0% +really want to have a guaranteed global +minimum that you're absolutely sure + + align:start position:0% +minimum that you're absolutely sure + + + align:start position:0% +minimum that you're absolutely sure +definitely is a global minimum then then + + align:start position:0% +definitely is a global minimum then then + + + align:start position:0% +definitely is a global minimum then then +you really need to use the global + + align:start position:0% +you really need to use the global + + + align:start position:0% +you really need to use the global +optimization methods and you really + + align:start position:0% +optimization methods and you really + + + align:start position:0% +optimization methods and you really +should talk to presser Barton and for + + align:start position:0% +should talk to presser Barton and for + + + align:start position:0% +should talk to presser Barton and for +these kinetic models he actually has a + + align:start position:0% +these kinetic models he actually has a + + + align:start position:0% +these kinetic models he actually has a +distributed code called G doc that will + + align:start position:0% +distributed code called G doc that will + + + align:start position:0% +distributed code called G doc that will +just find the global optimization as + + align:start position:0% +just find the global optimization as + + + align:start position:0% +just find the global optimization as +long as you don't have too many kinetic + + align:start position:0% +long as you don't have too many kinetic + + + align:start position:0% +long as you don't have too many kinetic +parameters I think if you go out to + + align:start position:0% +parameters I think if you go out to + + + align:start position:0% +parameters I think if you go out to +about six + + align:start position:0% +about six + + + align:start position:0% +about six +around six adjustable parameters who can + + align:start position:0% +around six adjustable parameters who can + + + align:start position:0% +around six adjustable parameters who can +handle if you have more than that then + + align:start position:0% +handle if you have more than that then + + + align:start position:0% +handle if you have more than that then +usually typically not but because a + + align:start position:0% +usually typically not but because a + + + align:start position:0% +usually typically not but because a +probably globalization methods is they + + align:start position:0% +probably globalization methods is they + + + align:start position:0% +probably globalization methods is they +scale exponentially with the number of + + align:start position:0% +scale exponentially with the number of + + + align:start position:0% +scale exponentially with the number of +adjustable parameters so or number of + + align:start position:0% +adjustable parameters so or number of + + + align:start position:0% +adjustable parameters so or number of +things you're trying to optimize it's + + align:start position:0% +things you're trying to optimize it's + + + align:start position:0% +things you're trying to optimize it's +now in the other hand if you have a + + align:start position:0% +now in the other hand if you have a + + + align:start position:0% +now in the other hand if you have a +model that you need to use more than six + + align:start position:0% +model that you need to use more than six + + + align:start position:0% +model that you need to use more than six +adjustable parameters to fit your data + + align:start position:0% +adjustable parameters to fit your data + + + align:start position:0% +adjustable parameters to fit your data +then you might want to try to think of a + + align:start position:0% +then you might want to try to think of a + + + align:start position:0% +then you might want to try to think of a +different experiment because you know I + + align:start position:0% +different experiment because you know I + + + align:start position:0% +different experiment because you know I +don't you know the famous saying is like + + align:start position:0% +don't you know the famous saying is like + + + align:start position:0% +don't you know the famous saying is like +you know we've give me n parameters I + + align:start position:0% +you know we've give me n parameters I + + + align:start position:0% +you know we've give me n parameters I +could fit an elephant so you know if you + + align:start position:0% +could fit an elephant so you know if you + + + align:start position:0% +could fit an elephant so you know if you +have more than six parameters and you're + + align:start position:0% +have more than six parameters and you're + + + align:start position:0% +have more than six parameters and you're +trying to fit some data set probably you + + align:start position:0% +trying to fit some data set probably you + + + align:start position:0% +trying to fit some data set probably you +probably be do it right you'll find a + + align:start position:0% +probably be do it right you'll find a + + + align:start position:0% +probably be do it right you'll find a +fit but it may not really prove anything + + align:start position:0% +fit but it may not really prove anything + + + align:start position:0% +fit but it may not really prove anything +so so so for that point of view + + align:start position:0% +so so so for that point of view + + + align:start position:0% +so so so for that point of view +professor Barton's Code G doc is pretty + + align:start position:0% +professor Barton's Code G doc is pretty + + + align:start position:0% +professor Barton's Code G doc is pretty +convenient for doing this nonlinear + + align:start position:0% +convenient for doing this nonlinear + + + align:start position:0% +convenient for doing this nonlinear +optimization so that's a code for a + + align:start position:0% +optimization so that's a code for a + + + align:start position:0% +optimization so that's a code for a +nonlinear optimization with differential + + align:start position:0% +nonlinear optimization with differential + + + align:start position:0% +nonlinear optimization with differential +equations and embedded and they could be + + align:start position:0% +equations and embedded and they could be + + + align:start position:0% +equations and embedded and they could be +staff and they can be large it doesn't + + align:start position:0% +staff and they can be large it doesn't + + + align:start position:0% +staff and they can be large it doesn't +matter we really managed to just the + + align:start position:0% +matter we really managed to just the + + + align:start position:0% +matter we really managed to just the +number of adjustable parameters yeah for + + align:start position:0% +number of adjustable parameters yeah for + + + align:start position:0% +number of adjustable parameters yeah for +the that's the cost of all right + + align:start position:0% +the that's the cost of all right + + + align:start position:0% +the that's the cost of all right +now there was a really good question + + align:start position:0% +now there was a really good question + + + align:start position:0% +now there was a really good question +that you asked I think in class last + + align:start position:0% +that you asked I think in class last + + + align:start position:0% +that you asked I think in class last +time maybe maybe the time before and it + + align:start position:0% +time maybe maybe the time before and it + + + align:start position:0% +time maybe maybe the time before and it +was what happens so so if so look at + + align:start position:0% +was what happens so so if so look at + + + align:start position:0% +was what happens so so if so look at +different cases you get so one case you + + align:start position:0% +different cases you get so one case you + + + align:start position:0% +different cases you get so one case you +got you know if ty squared theta past + + align:start position:0% +got you know if ty squared theta past + + + align:start position:0% +got you know if ty squared theta past +your best fitting parameters is a lot + + align:start position:0% +your best fitting parameters is a lot + + + align:start position:0% +your best fitting parameters is a lot +bigger than chi squared max then you're + + align:start position:0% +bigger than chi squared max then you're + + + align:start position:0% +bigger than chi squared max then you're +ready to say the model disproves it + + align:start position:0% + + + + align:start position:0% + +all right so that one you're okay if + + align:start position:0% +all right so that one you're okay if + + + align:start position:0% +all right so that one you're okay if +chi-squared of your best fit is is less + + align:start position:0% +chi-squared of your best fit is is less + + + align:start position:0% +chi-squared of your best fit is is less +than or sniffing only less than + + align:start position:0% +than or sniffing only less than + + + align:start position:0% +than or sniffing only less than +chi-squared nuts + + align:start position:0% +chi-squared nuts + + + align:start position:0% +chi-squared nuts +let's meet last much less though really + + align:start position:0% +let's meet last much less though really + + + align:start position:0% +let's meet last much less though really +less not equal then then you're really + + align:start position:0% +less not equal then then you're really + + + align:start position:0% +less not equal then then you're really +happy to say that the model is + + align:start position:0% +happy to say that the model is + + + align:start position:0% +happy to say that the model is +consistent the model of data consists of + + align:start position:0% +consistent the model of data consists of + + + align:start position:0% +consistent the model of data consists of +each other in in this case what you + + align:start position:0% +each other in in this case what you + + + align:start position:0% +each other in in this case what you +would normally do next is determine the + + align:start position:0% +would normally do next is determine the + + + align:start position:0% +would normally do next is determine the +confidence intervals on the Thetas that + + align:start position:0% +confidence intervals on the Thetas that + + + align:start position:0% +confidence intervals on the Thetas that +you adjusted right and if you read the + + align:start position:0% +you adjusted right and if you read the + + + align:start position:0% +you adjusted right and if you read the +chapter and numerical recipes for + + align:start position:0% +chapter and numerical recipes for + + + align:start position:0% +chapter and numerical recipes for +example or some of the notes online they + + align:start position:0% +example or some of the notes online they + + + align:start position:0% +example or some of the notes online they +can tell you how to do this right and so + + align:start position:0% +can tell you how to do this right and so + + + align:start position:0% +can tell you how to do this right and so +that was okay there is okay so the case + + align:start position:0% +that was okay there is okay so the case + + + align:start position:0% +that was okay there is okay so the case +that's really problematic is applying + + align:start position:0% +that's really problematic is applying + + + align:start position:0% +that's really problematic is applying +chi squared theta best and it's less + + align:start position:0% +chi squared theta best and it's less + + + align:start position:0% +chi squared theta best and it's less +than chi-squared max so you think the + + align:start position:0% +than chi-squared max so you think the + + + align:start position:0% +than chi-squared max so you think the +model is consistent with the data but + + align:start position:0% +model is consistent with the data but + + + align:start position:0% +model is consistent with the data but +it's pretty darn close just beta squared + + align:start position:0% +it's pretty darn close just beta squared + + + align:start position:0% +it's pretty darn close just beta squared +max and so then you have to figure out + + align:start position:0% +max and so then you have to figure out + + + align:start position:0% +max and so then you have to figure out +well the weird aspect of this is I now + + align:start position:0% +well the weird aspect of this is I now + + + align:start position:0% +well the weird aspect of this is I now +have there's my famous plot of theta 1 + + align:start position:0% +have there's my famous plot of theta 1 + + + align:start position:0% +have there's my famous plot of theta 1 +to theta 2 have two parameters I'm + + align:start position:0% +to theta 2 have two parameters I'm + + + align:start position:0% +to theta 2 have two parameters I'm +adjusting it 1 theta 2 here's my best + + align:start position:0% +adjusting it 1 theta 2 here's my best + + + align:start position:0% +adjusting it 1 theta 2 here's my best +fit if if PI squared Max and in the + + align:start position:0% +fit if if PI squared Max and in the + + + align:start position:0% +fit if if PI squared Max and in the +curve of constant chi squared max or + + align:start position:0% +curve of constant chi squared max or + + + align:start position:0% +curve of constant chi squared max or +something like this this is pi squared + + align:start position:0% +something like this this is pi squared + + + align:start position:0% +something like this this is pi squared +of theta equals max if it's like that + + align:start position:0% +of theta equals max if it's like that + + + align:start position:0% +of theta equals max if it's like that +then I have some big region of a lot of + + align:start position:0% +then I have some big region of a lot of + + + align:start position:0% +then I have some big region of a lot of +different theta values they give it + + align:start position:0% +different theta values they give it + + + align:start position:0% +different theta values they give it +pretty good fits and I'm happy to draw + + align:start position:0% +pretty good fits and I'm happy to draw + + + align:start position:0% +pretty good fits and I'm happy to draw +confidence intervals like draw lines + + align:start position:0% +confidence intervals like draw lines + + + align:start position:0% +confidence intervals like draw lines +here and here for example let's say + + align:start position:0% +here and here for example let's say + + + align:start position:0% +here and here for example let's say +that's the confidence interval in theta + + align:start position:0% +that's the confidence interval in theta + + + align:start position:0% +that's the confidence interval in theta +1 and I'm all right okay + + align:start position:0% +1 and I'm all right okay + + + align:start position:0% +1 and I'm all right okay +and I might you know it's it's sloped + + align:start position:0% +and I might you know it's it's sloped + + + align:start position:0% +and I might you know it's it's sloped +here so I might want to tell people + + align:start position:0% +here so I might want to tell people + + + align:start position:0% +here so I might want to tell people +about the covariance between theta 1 + + align:start position:0% +about the covariance between theta 1 + + + align:start position:0% +about the covariance between theta 1 +theta 2 all right but but I know what to + + align:start position:0% +theta 2 all right but but I know what to + + + align:start position:0% +theta 2 all right but but I know what to +do it's fine now suppose this is the + + align:start position:0% +do it's fine now suppose this is the + + + align:start position:0% +do it's fine now suppose this is the +case that's like this for + + align:start position:0% +case that's like this for + + + align:start position:0% +case that's like this for +scrutiny best is significantly less than + + align:start position:0% +scrutiny best is significantly less than + + + align:start position:0% +scrutiny best is significantly less than +chi-squared Meadows now suppose instead + + align:start position:0% + + + + align:start position:0% + +chi-squared best was very close to + + align:start position:0% +chi-squared best was very close to + + + align:start position:0% +chi-squared best was very close to +squared max so then here's cash mark max + + align:start position:0% +squared max so then here's cash mark max + + + align:start position:0% +squared max so then here's cash mark max +this is quite square to theta equals pi + + align:start position:0% +this is quite square to theta equals pi + + + align:start position:0% +this is quite square to theta equals pi +squared + + align:start position:0% +squared + + + align:start position:0% +squared +max this is that it's a good case here's + + align:start position:0% +max this is that it's a good case here's + + + align:start position:0% +max this is that it's a good case here's +the bad case so in the back case there + + align:start position:0% +the bad case so in the back case there + + + align:start position:0% +the bad case so in the back case there +is some region of Thetas that the models + + align:start position:0% +is some region of Thetas that the models + + + align:start position:0% +is some region of Thetas that the models +consistent with the data but it's very + + align:start position:0% +consistent with the data but it's very + + + align:start position:0% +consistent with the data but it's very +tiny there's a little tiny range of + + align:start position:0% +tiny there's a little tiny range of + + + align:start position:0% +tiny there's a little tiny range of +theta values that are that would make + + align:start position:0% +theta values that are that would make + + + align:start position:0% +theta values that are that would make +the models consistent data now what's + + align:start position:0% +the models consistent data now what's + + + align:start position:0% +the models consistent data now what's +weird about this is that my best fit + + align:start position:0% +weird about this is that my best fit + + + align:start position:0% +weird about this is that my best fit +it's not very good the chi-squared is + + align:start position:0% +it's not very good the chi-squared is + + + align:start position:0% +it's not very good the chi-squared is +almost up to my skysport the maximum + + align:start position:0% +almost up to my skysport the maximum + + + align:start position:0% +almost up to my skysport the maximum +chi-squared i would tolerate so it means + + align:start position:0% +chi-squared i would tolerate so it means + + + align:start position:0% +chi-squared i would tolerate so it means +my deviations between my model and data + + align:start position:0% +my deviations between my model and data + + + align:start position:0% +my deviations between my model and data +are pretty bad like like this plot + + align:start position:0% +are pretty bad like like this plot + + + align:start position:0% +are pretty bad like like this plot +actually okay and so like you know it + + align:start position:0% +actually okay and so like you know it + + + align:start position:0% +actually okay and so like you know it +could it's possible I was little bit + + align:start position:0% +could it's possible I was little bit + + + align:start position:0% +could it's possible I was little bit +unlucky and my dataset is pretty far off + + align:start position:0% +unlucky and my dataset is pretty far off + + + align:start position:0% +unlucky and my dataset is pretty far off +but still within the possible range and + + align:start position:0% +but still within the possible range and + + + align:start position:0% +but still within the possible range and +so maybe the model data are consistent + + align:start position:0% +so maybe the model data are consistent + + + align:start position:0% +so maybe the model data are consistent +but then when I try to compute the + + align:start position:0% +but then when I try to compute the + + + align:start position:0% +but then when I try to compute the +confidence intervals on my parameters + + align:start position:0% +confidence intervals on my parameters + + + align:start position:0% +confidence intervals on my parameters +there's only a really small range of + + align:start position:0% +there's only a really small range of + + + align:start position:0% +there's only a really small range of +parameters that are going to give good + + align:start position:0% +parameters that are going to give good + + + align:start position:0% +parameters that are going to give good +fits here because the best possible fit + + align:start position:0% +fits here because the best possible fit + + + align:start position:0% +fits here because the best possible fit +is this red line there's no there's no + + align:start position:0% +is this red line there's no there's no + + + align:start position:0% +is this red line there's no there's no +about choice in the event of the + + align:start position:0% +about choice in the event of the + + + align:start position:0% +about choice in the event of the +parameters just gonna go through all the + + align:start position:0% +parameters just gonna go through all the + + + align:start position:0% +parameters just gonna go through all the +circles right with this model so now I'm + + align:start position:0% +circles right with this model so now I'm + + + align:start position:0% +circles right with this model so now I'm +like well what's going on here so if I + + align:start position:0% +like well what's going on here so if I + + + align:start position:0% +like well what's going on here so if I +if I went ahead and do it the same way I + + align:start position:0% +if I went ahead and do it the same way I + + + align:start position:0% +if I went ahead and do it the same way I +did before I draw my my confidence + + align:start position:0% +did before I draw my my confidence + + + align:start position:0% +did before I draw my my confidence +intervals like this and say okay say wow + + align:start position:0% +intervals like this and say okay say wow + + + align:start position:0% +intervals like this and say okay say wow +I've done an amazingly great job of + + align:start position:0% +I've done an amazingly great job of + + + align:start position:0% +I've done an amazingly great job of +determining theta1 i never say the one + + align:start position:0% +determining theta1 i never say the one + + + align:start position:0% +determining theta1 i never say the one +very very very precisely and the safer + + align:start position:0% +very very very precisely and the safer + + + align:start position:0% +very very very precisely and the safer +data to here's theta two it's got mean + + align:start position:0% +data to here's theta two it's got mean + + + align:start position:0% +data to here's theta two it's got mean +that range to me and i really done a + + align:start position:0% +that range to me and i really done a + + + align:start position:0% +that range to me and i really done a +great job so you know i'm awesome + + align:start position:0% +great job so you know i'm awesome + + + align:start position:0% +great job so you know i'm awesome +but I'm only awesome because my original + + align:start position:0% +but I'm only awesome because my original + + + align:start position:0% +but I'm only awesome because my original +best fit wasn't very good so this is + + align:start position:0% +best fit wasn't very good so this is + + + align:start position:0% +best fit wasn't very good so this is +like might make you feel a little sick + + align:start position:0% +like might make you feel a little sick + + + align:start position:0% +like might make you feel a little sick +in your stomach if you get ready to + + align:start position:0% +in your stomach if you get ready to + + + align:start position:0% +in your stomach if you get ready to +publish the nature right and then you + + align:start position:0% +publish the nature right and then you + + + align:start position:0% +publish the nature right and then you +and if you're if you're the reviewers + + align:start position:0% +and if you're if you're the reviewers + + + align:start position:0% +and if you're if you're the reviewers +are on their game you might get + + align:start position:0% +are on their game you might get + + + align:start position:0% +are on their game you might get +something really skating jacked for the + + align:start position:0% +something really skating jacked for the + + + align:start position:0% +something really skating jacked for the +reviewers so there's kind of two ways to + + align:start position:0% +reviewers so there's kind of two ways to + + + align:start position:0% +reviewers so there's kind of two ways to +play it at this point + + align:start position:0% +play it at this point + + + align:start position:0% +play it at this point +one way is + + align:start position:0% +one way is + + + align:start position:0% +one way is +you are absolutely sure that your + + align:start position:0% +you are absolutely sure that your + + + align:start position:0% +you are absolutely sure that your +equations are correct you are Sir Isaac + + align:start position:0% +equations are correct you are Sir Isaac + + + align:start position:0% +equations are correct you are Sir Isaac +Newton you have just written the law of + + align:start position:0% +Newton you have just written the law of + + + align:start position:0% +Newton you have just written the law of +gravitation you are measuring the orbits + + align:start position:0% +gravitation you are measuring the orbits + + + align:start position:0% +gravitation you are measuring the orbits +of the moons of Jupiter and you are sure + + align:start position:0% +of the moons of Jupiter and you are sure + + + align:start position:0% +of the moons of Jupiter and you are sure +that your equations are right and so you + + align:start position:0% +that your equations are right and so you + + + align:start position:0% +that your equations are right and so you +know my problem is my my antiquated + + align:start position:0% +know my problem is my my antiquated + + + align:start position:0% +know my problem is my my antiquated +Tellez my telescopes of 1600 or not that + + align:start position:0% +Tellez my telescopes of 1600 or not that + + + align:start position:0% +Tellez my telescopes of 1600 or not that +great and so I think I have maybe maybe + + align:start position:0% +great and so I think I have maybe maybe + + + align:start position:0% +great and so I think I have maybe maybe +I miss estimated my error bars my + + align:start position:0% +I miss estimated my error bars my + + + align:start position:0% +I miss estimated my error bars my +measurements maybe might have some + + align:start position:0% +measurements maybe might have some + + + align:start position:0% +measurements maybe might have some +aberration or something the angles are + + align:start position:0% +aberration or something the angles are + + + align:start position:0% +aberration or something the angles are +off right + + align:start position:0% +off right + + + align:start position:0% +off right +I twist the telescope it looks this + + align:start position:0% +I twist the telescope it looks this + + + align:start position:0% +I twist the telescope it looks this +mislead star moves or something right + + align:start position:0% +mislead star moves or something right + + + align:start position:0% +mislead star moves or something right +okay so that's that's one possible way + + align:start position:0% +okay so that's that's one possible way + + + align:start position:0% +okay so that's that's one possible way +to go is say I really believe the model + + align:start position:0% +to go is say I really believe the model + + + align:start position:0% +to go is say I really believe the model +and so I believe that this is the truth + + align:start position:0% +and so I believe that this is the truth + + + align:start position:0% +and so I believe that this is the truth +and I really believe my chi-squared max + + align:start position:0% +and I really believe my chi-squared max + + + align:start position:0% +and I really believe my chi-squared max +to be what it is and I double checked my + + align:start position:0% +to be what it is and I double checked my + + + align:start position:0% +to be what it is and I double checked my +error bars and I think it's true so I + + align:start position:0% +error bars and I think it's true so I + + + align:start position:0% +error bars and I think it's true so I +think I've done a great job and I should + + align:start position:0% +think I've done a great job and I should + + + align:start position:0% +think I've done a great job and I should +publish it in nature because I determine + + align:start position:0% +publish it in nature because I determine + + + align:start position:0% +publish it in nature because I determine +these parameters with 17 more decimal + + align:start position:0% +these parameters with 17 more decimal + + + align:start position:0% +these parameters with 17 more decimal +places than anybody ever could before + + align:start position:0% +places than anybody ever could before + + + align:start position:0% +places than anybody ever could before +okay so that's one way to look at it the + + align:start position:0% +okay so that's one way to look at it the + + + align:start position:0% +okay so that's one way to look at it the +other way to look at it is what's + + align:start position:0% +other way to look at it is what's + + + align:start position:0% +other way to look at it is what's +recommended the numerical recipes book + + align:start position:0% +recommended the numerical recipes book + + + align:start position:0% +recommended the numerical recipes book +and they say don't use instead of + + align:start position:0% +and they say don't use instead of + + + align:start position:0% +and they say don't use instead of +writing equation to be high squared of + + align:start position:0% +writing equation to be high squared of + + + align:start position:0% +writing equation to be high squared of +theta has to be less than chi-squared + + align:start position:0% +theta has to be less than chi-squared + + + align:start position:0% +theta has to be less than chi-squared +max they say when you're computing the + + align:start position:0% +max they say when you're computing the + + + align:start position:0% +max they say when you're computing the +confidence intervals instead write high + + align:start position:0% +confidence intervals instead write high + + + align:start position:0% +confidence intervals instead write high +squared of theta has to be less than PI + + align:start position:0% +squared of theta has to be less than PI + + + align:start position:0% +squared of theta has to be less than PI +squared best-fit plus I squared nice so + + align:start position:0% +squared best-fit plus I squared nice so + + + align:start position:0% +squared best-fit plus I squared nice so +they say don't use those dinky little + + align:start position:0% +they say don't use those dinky little + + + align:start position:0% +they say don't use those dinky little +circle here draw a nice big line around + + align:start position:0% +circle here draw a nice big line around + + + align:start position:0% +circle here draw a nice big line around +there and and and what is this saying I + + align:start position:0% +there and and and what is this saying I + + + align:start position:0% +there and and and what is this saying I +guess it's the saying is I don't believe + + align:start position:0% +guess it's the saying is I don't believe + + + align:start position:0% +guess it's the saying is I don't believe +that my my poor agreement with model + + align:start position:0% +that my my poor agreement with model + + + align:start position:0% +that my my poor agreement with model +data justifies me to declaring very + + align:start position:0% +data justifies me to declaring very + + + align:start position:0% +data justifies me to declaring very +narrow parameter values so I just used + + align:start position:0% +narrow parameter values so I just used + + + align:start position:0% +narrow parameter values so I just used +the kinds of parameter value confidence + + align:start position:0% +the kinds of parameter value confidence + + + align:start position:0% +the kinds of parameter value confidence +intervals that it would have actually + + align:start position:0% +intervals that it would have actually + + + align:start position:0% +intervals that it would have actually +computed at a priori when I do my + + align:start position:0% +computed at a priori when I do my + + + align:start position:0% +computed at a priori when I do my +experimental design I think that's + + align:start position:0% +experimental design I think that's + + + align:start position:0% +experimental design I think that's +really how well I can determine stuff + + align:start position:0% +really how well I can determine stuff + + + align:start position:0% +really how well I can determine stuff +and and I think there's something is + + align:start position:0% +and and I think there's something is + + + align:start position:0% +and and I think there's something is +wrong that my chrisquared best fit is so + + align:start position:0% +wrong that my chrisquared best fit is so + + + align:start position:0% +wrong that my chrisquared best fit is so +bad maybe I don't do my global + + align:start position:0% +bad maybe I don't do my global + + + align:start position:0% +bad maybe I don't do my global +optimization right and so I have the + + align:start position:0% +optimization right and so I have the + + + align:start position:0% +optimization right and so I have the +wrong parameters maybe + + align:start position:0% +wrong parameters maybe + + + align:start position:0% +wrong parameters maybe +I misunderstood estimated Myer bars and + + align:start position:0% +I misunderstood estimated Myer bars and + + + align:start position:0% +I misunderstood estimated Myer bars and +so my Chi squares are all off maybe I + + align:start position:0% +so my Chi squares are all off maybe I + + + align:start position:0% +so my Chi squares are all off maybe I +don't know what else happened something + + align:start position:0% +don't know what else happened something + + + align:start position:0% +don't know what else happened something +happened and I don't believe on that + + align:start position:0% +happened and I don't believe on that + + + align:start position:0% +happened and I don't believe on that +good so therefore I'm going to quote + + align:start position:0% +good so therefore I'm going to quote + + + align:start position:0% +good so therefore I'm going to quote +much broader confidence intervals which + + align:start position:0% +much broader confidence intervals which + + + align:start position:0% +much broader confidence intervals which +means much less precision in my + + align:start position:0% +means much less precision in my + + + align:start position:0% +means much less precision in my +determination of parameters and that's + + align:start position:0% +determination of parameters and that's + + + align:start position:0% +determination of parameters and that's +what the dimeric are these guys + + align:start position:0% +what the dimeric are these guys + + + align:start position:0% +what the dimeric are these guys +recommend you should do but you know + + align:start position:0% +recommend you should do but you know + + + align:start position:0% +recommend you should do but you know +it's up to you and I see the post way so + + align:start position:0% +it's up to you and I see the post way so + + + align:start position:0% +it's up to you and I see the post way so +in the people on the Nobel Prize for the + + align:start position:0% +in the people on the Nobel Prize for the + + + align:start position:0% +in the people on the Nobel Prize for the +dark energy do you guys know about this + + align:start position:0% +dark energy do you guys know about this + + + align:start position:0% +dark energy do you guys know about this +so have you ever saw that data there so + + align:start position:0% +so have you ever saw that data there so + + + align:start position:0% +so have you ever saw that data there so +that's one where they said they were + + align:start position:0% +that's one where they said they were + + + align:start position:0% +that's one where they said they were +using eye x theory of relativity general + + align:start position:0% +using eye x theory of relativity general + + + align:start position:0% +using eye x theory of relativity general +relativity they say we believe Einstein + + align:start position:0% +relativity they say we believe Einstein + + + align:start position:0% +relativity they say we believe Einstein +we believe the equations true and we're + + align:start position:0% +we believe the equations true and we're + + + align:start position:0% +we believe the equations true and we're +not going to know the fact that it you + + align:start position:0% +not going to know the fact that it you + + + align:start position:0% +not going to know the fact that it you +know the data only matches when you + + align:start position:0% +know the data only matches when you + + + align:start position:0% +know the data only matches when you +choose a certain value of the + + align:start position:0% +choose a certain value of the + + + align:start position:0% +choose a certain value of the +cosmological constant we're just going + + align:start position:0% +cosmological constant we're just going + + + align:start position:0% +cosmological constant we're just going +to go with it and we're reporting that's + + align:start position:0% +to go with it and we're reporting that's + + + align:start position:0% +to go with it and we're reporting that's +the value of the cosmological constant + + align:start position:0% +the value of the cosmological constant + + + align:start position:0% +the value of the cosmological constant +now some other people might say that's + + align:start position:0% +now some other people might say that's + + + align:start position:0% +now some other people might say that's +kind of goofy theory Einstein change of + + align:start position:0% +kind of goofy theory Einstein change of + + + align:start position:0% +kind of goofy theory Einstein change of +mind six times about whether what the + + align:start position:0% +mind six times about whether what the + + + align:start position:0% +mind six times about whether what the +cosmic out cosmological constant in the + + align:start position:0% +cosmic out cosmological constant in the + + + align:start position:0% +cosmic out cosmological constant in the +equation at all so I'm not so confident + + align:start position:0% +equation at all so I'm not so confident + + + align:start position:0% +equation at all so I'm not so confident +and I would yeah we port something + + align:start position:0% +and I would yeah we port something + + + align:start position:0% +and I would yeah we port something +different but they went with her gut + + align:start position:0% +different but they went with her gut + + + align:start position:0% +different but they went with her gut +they said we believe Einstein they went + + align:start position:0% +they said we believe Einstein they went + + + align:start position:0% +they said we believe Einstein they went +with it the Nobel Committee agreed and + + align:start position:0% +with it the Nobel Committee agreed and + + + align:start position:0% +with it the Nobel Committee agreed and +they got the Nimmo price so you know + + align:start position:0% +they got the Nimmo price so you know + + + align:start position:0% +they got the Nimmo price so you know +you're taking your chances the new + + align:start position:0% +you're taking your chances the new + + + align:start position:0% +you're taking your chances the new +recipe guys are more like engineers they + + align:start position:0% +recipe guys are more like engineers they + + + align:start position:0% +recipe guys are more like engineers they +say we don't believe models that watch + + align:start position:0% +say we don't believe models that watch + + + align:start position:0% +say we don't believe models that watch +anyway let's just use a more + + align:start position:0% +anyway let's just use a more + + + align:start position:0% +anyway let's just use a more +conservative confidence intervals any + + align:start position:0% +conservative confidence intervals any + + + align:start position:0% +conservative confidence intervals any +questions about this ok all right so now + + align:start position:0% +questions about this ok all right so now + + + align:start position:0% +questions about this ok all right so now +I've changed topics you know change two + + align:start position:0% +I've changed topics you know change two + + + align:start position:0% +I've changed topics you know change two +operators splitting so if you remember + + align:start position:0% +operators splitting so if you remember + + + align:start position:0% +operators splitting so if you remember +back we're talking about + + align:start position:0% +back we're talking about + + + align:start position:0% +back we're talking about +boundary value problems we're often + + align:start position:0% +boundary value problems we're often + + + align:start position:0% +boundary value problems we're often +trying to solve problems that are like + + align:start position:0% +trying to solve problems that are like + + + align:start position:0% +trying to solve problems that are like +this + + align:start position:0% + + + + align:start position:0% + +right so this is a conservation equation + + align:start position:0% +right so this is a conservation equation + + + align:start position:0% +right so this is a conservation equation +for species in a reacting reacting flow + + align:start position:0% +for species in a reacting reacting flow + + + align:start position:0% +for species in a reacting reacting flow +situation so you have some convection + + align:start position:0% +situation so you have some convection + + + align:start position:0% +situation so you have some convection +you have some diffusion you have some + + align:start position:0% +you have some diffusion you have some + + + align:start position:0% +you have some diffusion you have some +reactions now in my life I have a lot of + + align:start position:0% +reactions now in my life I have a lot of + + + align:start position:0% +reactions now in my life I have a lot of +models I have about 200 species in them + + align:start position:0% +models I have about 200 species in them + + + align:start position:0% +models I have about 200 species in them +so I've this K is 200 different + + align:start position:0% +so I've this K is 200 different + + + align:start position:0% +so I've this K is 200 different +variables and then you have these + + align:start position:0% +variables and then you have these + + + align:start position:0% +variables and then you have these +equations and on top of them you have + + align:start position:0% +equations and on top of them you have + + + align:start position:0% +equations and on top of them you have +the nav your six equations for the + + align:start position:0% +the nav your six equations for the + + + align:start position:0% +the nav your six equations for the +momentum conservation and continuity and + + align:start position:0% +momentum conservation and continuity and + + + align:start position:0% +momentum conservation and continuity and +so this is actually pretty bad set of + + align:start position:0% +so this is actually pretty bad set of + + + align:start position:0% +so this is actually pretty bad set of +equations and typically the chemistry is + + align:start position:0% +equations and typically the chemistry is + + + align:start position:0% +equations and typically the chemistry is +stiff because I have chemistry + + align:start position:0% +stiff because I have chemistry + + + align:start position:0% +stiff because I have chemistry +timescales that'll be like in Pico + + align:start position:0% +timescales that'll be like in Pico + + + align:start position:0% +timescales that'll be like in Pico +seconds sub sub nanosecond timescales + + align:start position:0% +seconds sub sub nanosecond timescales + + + align:start position:0% +seconds sub sub nanosecond timescales +and I'm caring about simulating in my + + align:start position:0% +and I'm caring about simulating in my + + + align:start position:0% +and I'm caring about simulating in my +case maybe I've advanced new engine + + align:start position:0% +case maybe I've advanced new engine + + + align:start position:0% +case maybe I've advanced new engine +burning some fuel and so we're running + + align:start position:0% +burning some fuel and so we're running + + + align:start position:0% +burning some fuel and so we're running +over a simulation of a piston cycle + + align:start position:0% +over a simulation of a piston cycle + + + align:start position:0% +over a simulation of a piston cycle +maybe 10 milliseconds but the chemistry + + align:start position:0% +maybe 10 milliseconds but the chemistry + + + align:start position:0% +maybe 10 milliseconds but the chemistry +sub nanosecond so then you multiply it + + align:start position:0% +sub nanosecond so then you multiply it + + + align:start position:0% +sub nanosecond so then you multiply it +out so that's like I'm going at 10 to + + align:start position:0% +out so that's like I'm going at 10 to + + + align:start position:0% +out so that's like I'm going at 10 to +minus 2 seconds down to 10 to minus 10 + + align:start position:0% +minus 2 seconds down to 10 to minus 10 + + + align:start position:0% +minus 2 seconds down to 10 to minus 10 +seconds so it's a two orders of + + align:start position:0% +seconds so it's a two orders of + + + align:start position:0% +seconds so it's a two orders of +magnitude difference in timescales so + + align:start position:0% +magnitude difference in timescales so + + + align:start position:0% +magnitude difference in timescales so +I'm in a bad way trying to solve this + + align:start position:0% +I'm in a bad way trying to solve this + + + align:start position:0% +I'm in a bad way trying to solve this +equation and I have 200 of these guys + + align:start position:0% +equation and I have 200 of these guys + + + align:start position:0% +equation and I have 200 of these guys +coupled to each other and then I think + + align:start position:0% +coupled to each other and then I think + + + align:start position:0% +coupled to each other and then I think +of what my mesh looks like and I'm + + align:start position:0% +of what my mesh looks like and I'm + + + align:start position:0% +of what my mesh looks like and I'm +trying to simulate it inside the piston + + align:start position:0% +trying to simulate it inside the piston + + + align:start position:0% +trying to simulate it inside the piston +actually I have a moving mesh because + + align:start position:0% +actually I have a moving mesh because + + + align:start position:0% +actually I have a moving mesh because +the Pistons compress a so the equations + + align:start position:0% +the Pistons compress a so the equations + + + align:start position:0% +the Pistons compress a so the equations +are kind of complicated for even what + + align:start position:0% +are kind of complicated for even what + + + align:start position:0% +are kind of complicated for even what +the mesh is doing and then I need a + + align:start position:0% +the mesh is doing and then I need a + + + align:start position:0% +the mesh is doing and then I need a +bunch of mesh points there because the + + align:start position:0% +bunch of mesh points there because the + + + align:start position:0% +bunch of mesh points there because the +do you guys know the Cole MacGrath scale + + align:start position:0% +do you guys know the Cole MacGrath scale + + + align:start position:0% +do you guys know the Cole MacGrath scale +you go to learn this yet now it's a + + align:start position:0% +you go to learn this yet now it's a + + + align:start position:0% +you go to learn this yet now it's a +scale like the minimum Eddy size if you + + align:start position:0% +scale like the minimum Eddy size if you + + + align:start position:0% +scale like the minimum Eddy size if you +have a turbulent flow and that's pretty + + align:start position:0% +have a turbulent flow and that's pretty + + + align:start position:0% +have a turbulent flow and that's pretty +darn small also so it might be submicron + + align:start position:0% +darn small also so it might be submicron + + + align:start position:0% +darn small also so it might be submicron +and so I have length scale that's what + + align:start position:0% +and so I have length scale that's what + + + align:start position:0% +and so I have length scale that's what +let's scale this like you know microns + + align:start position:0% +let's scale this like you know microns + + + align:start position:0% +let's scale this like you know microns +maybe so 10 to minus 6 meters but the + + align:start position:0% +maybe so 10 to minus 6 meters but the + + + align:start position:0% +maybe so 10 to minus 6 meters but the +piston diameter is a couple centimeters + + align:start position:0% +piston diameter is a couple centimeters + + + align:start position:0% +piston diameter is a couple centimeters +so again I have like four orders of + + align:start position:0% +so again I have like four orders of + + + align:start position:0% +so again I have like four orders of +magnitude between the mesh size I need + + align:start position:0% +magnitude between the mesh size I need + + + align:start position:0% +magnitude between the mesh size I need +to resolve the physics + + align:start position:0% +to resolve the physics + + + align:start position:0% +to resolve the physics +and the and the size of the thing so I + + align:start position:0% +and the and the size of the thing so I + + + align:start position:0% +and the and the size of the thing so I +need about 10,000 point across the + + align:start position:0% +need about 10,000 point across the + + + align:start position:0% +need about 10,000 point across the +cylinder but it's a 3d problem so I need + + align:start position:0% +cylinder but it's a 3d problem so I need + + + align:start position:0% +cylinder but it's a 3d problem so I need +10 to the 4 times 10 to the 4th times 10 + + align:start position:0% +10 to the 4 times 10 to the 4th times 10 + + + align:start position:0% +10 to the 4 times 10 to the 4th times 10 +to the 4th so I need 10 to the 12th mesh + + align:start position:0% +to the 4th so I need 10 to the 12th mesh + + + align:start position:0% +to the 4th so I need 10 to the 12th mesh +points and then I have 200 variables + + align:start position:0% +points and then I have 200 variables + + + align:start position:0% +points and then I have 200 variables +state variables at each mesh point so I + + align:start position:0% +state variables at each mesh point so I + + + align:start position:0% +state variables at each mesh point so I +have 10 to the 14th state variables so + + align:start position:0% +have 10 to the 14th state variables so + + + align:start position:0% +have 10 to the 14th state variables so +how much remember you have in your + + align:start position:0% +how much remember you have in your + + + align:start position:0% +how much remember you have in your +computer much RAM yeah probably like 16 + + align:start position:0% +computer much RAM yeah probably like 16 + + + align:start position:0% +computer much RAM yeah probably like 16 +gigabytes they have ten to the ninth ten + + align:start position:0% +gigabytes they have ten to the ninth ten + + + align:start position:0% +gigabytes they have ten to the ninth ten +to the ninth bytes is that right now 10 + + align:start position:0% +to the ninth bytes is that right now 10 + + + align:start position:0% +to the ninth bytes is that right now 10 +no what's key again nice ok so a 10 to + + align:start position:0% +no what's key again nice ok so a 10 to + + + align:start position:0% +no what's key again nice ok so a 10 to +the 10th sorry 10 to the 10th bytes but + + align:start position:0% +the 10th sorry 10 to the 10th bytes but + + + align:start position:0% +the 10th sorry 10 to the 10th bytes but +I have 10 to the 14 state variables so I + + align:start position:0% +I have 10 to the 14 state variables so I + + + align:start position:0% +I have 10 to the 14 state variables so I +have a problem so they need to figure + + align:start position:0% +have a problem so they need to figure + + + align:start position:0% +have a problem so they need to figure +out how you solve it so there's two + + align:start position:0% +out how you solve it so there's two + + + align:start position:0% +out how you solve it so there's two +schools of thought of how to solve these + + align:start position:0% +schools of thought of how to solve these + + + align:start position:0% +schools of thought of how to solve these +equations the school thought which has + + align:start position:0% +equations the school thought which has + + + align:start position:0% +equations the school thought which has +actually been the most successful so far + + align:start position:0% +actually been the most successful so far + + + align:start position:0% +actually been the most successful so far +but is not readily available is to get + + align:start position:0% +but is not readily available is to get + + + align:start position:0% +but is not readily available is to get +the government to build you the biggest + + align:start position:0% +the government to build you the biggest + + + align:start position:0% +the government to build you the biggest +possible computer in the world with as + + align:start position:0% +possible computer in the world with as + + + align:start position:0% +possible computer in the world with as +much memory as possible and then you can + + align:start position:0% +much memory as possible and then you can + + + align:start position:0% +much memory as possible and then you can +actually keep track of your state vector + + align:start position:0% +actually keep track of your state vector + + + align:start position:0% +actually keep track of your state vector +all 10 to the 14th elements and and you + + align:start position:0% +all 10 to the 14th elements and and you + + + align:start position:0% +all 10 to the 14th elements and and you +reserve the this whole computer for + + align:start position:0% +reserve the this whole computer for + + + align:start position:0% +reserve the this whole computer for +yourself for you know a month and just + + align:start position:0% +yourself for you know a month and just + + + align:start position:0% +yourself for you know a month and just +run it and you hear how to parallelize + + align:start position:0% +run it and you hear how to parallelize + + + align:start position:0% +run it and you hear how to parallelize +all the calculations and you just use an + + align:start position:0% +all the calculations and you just use an + + + align:start position:0% +all the calculations and you just use an +explicit solver and so that way it's + + align:start position:0% +explicit solver and so that way it's + + + align:start position:0% +explicit solver and so that way it's +just straightforward all you're doing is + + align:start position:0% +just straightforward all you're doing is + + + align:start position:0% +just straightforward all you're doing is +you're computing you know why T plus + + align:start position:0% +you're computing you know why T plus + + + align:start position:0% +you're computing you know why T plus +delta T is equal to something and it's + + align:start position:0% +delta T is equal to something and it's + + + align:start position:0% +delta T is equal to something and it's +just an explicit formula OD 45 fancy + + align:start position:0% +just an explicit formula OD 45 fancy + + + align:start position:0% +just an explicit formula OD 45 fancy +version of that ok and it's just algebra + + align:start position:0% +version of that ok and it's just algebra + + + align:start position:0% +version of that ok and it's just algebra +and you just add them up and it's no + + align:start position:0% +and you just add them up and it's no + + + align:start position:0% +and you just add them up and it's no +problem but this is a limited limited + + align:start position:0% +problem but this is a limited limited + + + align:start position:0% +problem but this is a limited limited +feasibility thing this only became + + align:start position:0% +feasibility thing this only became + + + align:start position:0% +feasibility thing this only became +possible about three years ago when they + + align:start position:0% +possible about three years ago when they + + + align:start position:0% +possible about three years ago when they +build a computer that actually had + + align:start position:0% +build a computer that actually had + + + align:start position:0% +build a computer that actually had +enough memory to store the state vector + + align:start position:0% +enough memory to store the state vector + + + align:start position:0% +enough memory to store the state vector +it's also if the equations are too stiff + + align:start position:0% +it's also if the equations are too stiff + + + align:start position:0% +it's also if the equations are too stiff +it still doesn't work because the the + + align:start position:0% +it still doesn't work because the the + + + align:start position:0% +it still doesn't work because the the +step size the time step you need to use + + align:start position:0% +step size the time step you need to use + + + align:start position:0% +step size the time step you need to use +is so small so say is 100 picoseconds + + align:start position:0% +is so small so say is 100 picoseconds + + + align:start position:0% +is so small so say is 100 picoseconds +you're trying to get out to a + + align:start position:0% +you're trying to get out to a + + + align:start position:0% +you're trying to get out to a +millisecond so you need 10 to the 8th + + align:start position:0% +millisecond so you need 10 to the 8th + + + align:start position:0% +millisecond so you need 10 to the 8th +something time steps which means you + + align:start position:0% +something time steps which means you + + + align:start position:0% +something time steps which means you +need to use double precision + + align:start position:0% +need to use double precision + + + align:start position:0% +need to use double precision +numbers all the way through but if the + + align:start position:0% +numbers all the way through but if the + + + align:start position:0% +numbers all the way through but if the +computer the government builds you a + + align:start position:0% +computer the government builds you a + + + align:start position:0% +computer the government builds you a +64-bit or 128-bit machine then if you + + align:start position:0% +64-bit or 128-bit machine then if you + + + align:start position:0% +64-bit or 128-bit machine then if you +can do it but it anyway this is like a + + align:start position:0% +can do it but it anyway this is like a + + + align:start position:0% +can do it but it anyway this is like a +very special kind of aversion so now + + align:start position:0% +very special kind of aversion so now + + + align:start position:0% +very special kind of aversion so now +most people including me I don't have + + align:start position:0% +most people including me I don't have + + + align:start position:0% +most people including me I don't have +access to that kind of kind of computer + + align:start position:0% +access to that kind of kind of computer + + + align:start position:0% +access to that kind of kind of computer +power it actually if you want to read + + align:start position:0% +power it actually if you want to read + + + align:start position:0% +power it actually if you want to read +about that there's a woman who does that + + align:start position:0% +about that there's a woman who does that + + + align:start position:0% +about that there's a woman who does that +is Jacqueline Chen and you might want to + + align:start position:0% +is Jacqueline Chen and you might want to + + + align:start position:0% +is Jacqueline Chen and you might want to +look on the internet and see about her + + align:start position:0% +look on the internet and see about her + + + align:start position:0% +look on the internet and see about her +and somehow she became buddies with the + + align:start position:0% +and somehow she became buddies with the + + + align:start position:0% +and somehow she became buddies with the +people in charge of the super computers + + align:start position:0% +people in charge of the super computers + + + align:start position:0% +people in charge of the super computers +and so they're happy to give her a month + + align:start position:0% +and so they're happy to give her a month + + + align:start position:0% +and so they're happy to give her a month +of video the best computer in the world + + align:start position:0% +of video the best computer in the world + + + align:start position:0% +of video the best computer in the world +every year and she runs some awesome + + align:start position:0% +every year and she runs some awesome + + + align:start position:0% +every year and she runs some awesome +really awesome calculation that's + + align:start position:0% +really awesome calculation that's + + + align:start position:0% +really awesome calculation that's +exactly right + + align:start position:0% +exactly right + + + align:start position:0% +exactly right +solves everything as all the state + + align:start position:0% +solves everything as all the state + + + align:start position:0% +solves everything as all the state +variables 10 to the 14th it's fantastic + + align:start position:0% +variables 10 to the 14th it's fantastic + + + align:start position:0% +variables 10 to the 14th it's fantastic +and that's like the currently that's the + + align:start position:0% +and that's like the currently that's the + + + align:start position:0% +and that's like the currently that's the +benchmark for how people test + + align:start position:0% +benchmark for how people test + + + align:start position:0% +benchmark for how people test +approximate methods for how to solving + + align:start position:0% +approximate methods for how to solving + + + align:start position:0% +approximate methods for how to solving +this because then she actually has the + + align:start position:0% +this because then she actually has the + + + align:start position:0% +this because then she actually has the +full solution numerically out converged + + align:start position:0% + + + + align:start position:0% + +but this again it's like a limited + + align:start position:0% +but this again it's like a limited + + + align:start position:0% +but this again it's like a limited +applicability so new so a lot of people + + align:start position:0% +applicability so new so a lot of people + + + align:start position:0% +applicability so new so a lot of people +are working on approximation methods to + + align:start position:0% +are working on approximation methods to + + + align:start position:0% +are working on approximation methods to +try to solve this equation if I don't + + align:start position:0% +try to solve this equation if I don't + + + align:start position:0% +try to solve this equation if I don't +have access to such awesome computer + + align:start position:0% +have access to such awesome computer + + + align:start position:0% +have access to such awesome computer +resources and the general idea of them + + align:start position:0% +resources and the general idea of them + + + align:start position:0% +resources and the general idea of them +well the two ideas so one idea is + + align:start position:0% +well the two ideas so one idea is + + + align:start position:0% +well the two ideas so one idea is +somehow get rid of the turbulence ok and + + align:start position:0% +somehow get rid of the turbulence ok and + + + align:start position:0% +somehow get rid of the turbulence ok and +so what they do is they use a match + + align:start position:0% +so what they do is they use a match + + + align:start position:0% +so what they do is they use a match +that's coarser that you know what you + + align:start position:0% +that's coarser that you know what you + + + align:start position:0% +that's coarser that you know what you +would need to resolve the color graphs + + align:start position:0% +would need to resolve the color graphs + + + align:start position:0% +would need to resolve the color graphs +scale and then they use models for what + + align:start position:0% +scale and then they use models for what + + + align:start position:0% +scale and then they use models for what +happens for itty-bitty tiny Eddie's and + + align:start position:0% +happens for itty-bitty tiny Eddie's and + + + align:start position:0% +happens for itty-bitty tiny Eddie's and +those are called sub-grid scale models + + align:start position:0% +those are called sub-grid scale models + + + align:start position:0% +those are called sub-grid scale models +and this whole approach is called large + + align:start position:0% +and this whole approach is called large + + + align:start position:0% +and this whole approach is called large +Eddy simulation and the idea is you keep + + align:start position:0% +Eddy simulation and the idea is you keep + + + align:start position:0% +Eddy simulation and the idea is you keep +track of the large Eddie's the big + + align:start position:0% +track of the large Eddie's the big + + + align:start position:0% +track of the large Eddie's the big +recirculation zones that's modeled + + align:start position:0% +recirculation zones that's modeled + + + align:start position:0% +recirculation zones that's modeled +explicitly but you don't keep track of + + align:start position:0% +explicitly but you don't keep track of + + + align:start position:0% +explicitly but you don't keep track of +all the itty-bitty tiny swirling off + + align:start position:0% +all the itty-bitty tiny swirling off + + + align:start position:0% +all the itty-bitty tiny swirling off +little Eddie's that last for a little + + align:start position:0% +little Eddie's that last for a little + + + align:start position:0% +little Eddie's that last for a little +second a little bit of period of time + + align:start position:0% +second a little bit of period of time + + + align:start position:0% +second a little bit of period of time +before they dissipate because of + + align:start position:0% +before they dissipate because of + + + align:start position:0% +before they dissipate because of +diffusion ok so that's the concept and + + align:start position:0% +diffusion ok so that's the concept and + + + align:start position:0% +diffusion ok so that's the concept and +and there's I don't know half of them + + align:start position:0% +and there's I don't know half of them + + + align:start position:0% +and there's I don't know half of them +all of mechanical engineers who are + + align:start position:0% +all of mechanical engineers who are + + + align:start position:0% +all of mechanical engineers who are +working in larger these simulations are + + align:start position:0% +working in larger these simulations are + + + align:start position:0% +working in larger these simulations are +trying to figure out and do this maybe + + align:start position:0% +trying to figure out and do this maybe + + + align:start position:0% +trying to figure out and do this maybe +Jim is one I don't know no ok but at + + align:start position:0% +Jim is one I don't know no ok but at + + + align:start position:0% +Jim is one I don't know no ok but at +least he knows something probably so + + align:start position:0% +least he knows something probably so + + + align:start position:0% +least he knows something probably so +that's one one whole branch is to try + + align:start position:0% +that's one one whole branch is to try + + + align:start position:0% +that's one one whole branch is to try +get rid of turbulence and basically + + align:start position:0% +get rid of turbulence and basically + + + align:start position:0% +get rid of turbulence and basically +that's trying to reduce + + align:start position:0% +that's trying to reduce + + + align:start position:0% +that's trying to reduce +the the density of mesh I need so trying + + align:start position:0% +the the density of mesh I need so trying + + + align:start position:0% +the the density of mesh I need so trying +to give her this used to spatial mesh + + align:start position:0% +to give her this used to spatial mesh + + + align:start position:0% +to give her this used to spatial mesh +but the other issue is the time and the + + align:start position:0% +but the other issue is the time and the + + + align:start position:0% +but the other issue is the time and the +time a is even worse right because I + + align:start position:0% +time a is even worse right because I + + + align:start position:0% +time a is even worse right because I +said I have 10 to the 8th time points + + align:start position:0% +said I have 10 to the 8th time points + + + align:start position:0% +said I have 10 to the 8th time points +and I only need 10 to the 4th + + align:start position:0% +and I only need 10 to the 4th + + + align:start position:0% +and I only need 10 to the 4th +spatial mesh points in the dimension so + + align:start position:0% +spatial mesh points in the dimension so + + + align:start position:0% +spatial mesh points in the dimension so +in some ways that you know if I could do + + align:start position:0% +in some ways that you know if I could do + + + align:start position:0% +in some ways that you know if I could do +something with a time that really can + + align:start position:0% +something with a time that really can + + + align:start position:0% +something with a time that really can +buy me a lot I have eight orders of + + align:start position:0% +buy me a lot I have eight orders of + + + align:start position:0% +buy me a lot I have eight orders of +magnitude I'd like to try to reduce to + + align:start position:0% +magnitude I'd like to try to reduce to + + + align:start position:0% +magnitude I'd like to try to reduce to +you know three orders maybe dude am I + + align:start position:0% +you know three orders maybe dude am I + + + align:start position:0% +you know three orders maybe dude am I +good that'd be really nice so the that + + align:start position:0% +good that'd be really nice so the that + + + align:start position:0% +good that'd be really nice so the that +idea is to say well let's separate the + + align:start position:0% +idea is to say well let's separate the + + + align:start position:0% +idea is to say well let's separate the +fast timescales from the slow timescales + + align:start position:0% +fast timescales from the slow timescales + + + align:start position:0% +fast timescales from the slow timescales +and in fact all the fast timescales + + align:start position:0% +and in fact all the fast timescales + + + align:start position:0% +and in fact all the fast timescales +mostly are all chemistry particularly + + align:start position:0% +mostly are all chemistry particularly + + + align:start position:0% +mostly are all chemistry particularly +after I changed it large Eddy simulation + + align:start position:0% +after I changed it large Eddy simulation + + + align:start position:0% +after I changed it large Eddy simulation +where I get rid of the really small + + align:start position:0% +where I get rid of the really small + + + align:start position:0% +where I get rid of the really small +spatial scales then the the time scale + + align:start position:0% +spatial scales then the the time scale + + + align:start position:0% +spatial scales then the the time scale +of diffusion over this big match is kind + + align:start position:0% +of diffusion over this big match is kind + + + align:start position:0% +of diffusion over this big match is kind +of slow and so I can just I can go to a + + align:start position:0% +of slow and so I can just I can go to a + + + align:start position:0% +of slow and so I can just I can go to a +time scale that's completely controlled + + align:start position:0% +time scale that's completely controlled + + + align:start position:0% +time scale that's completely controlled +by chemistry so we already told you how + + align:start position:0% +by chemistry so we already told you how + + + align:start position:0% +by chemistry so we already told you how +do you solve stiff differential + + align:start position:0% +do you solve stiff differential + + + align:start position:0% +do you solve stiff differential +equations use the stuffs all right and + + align:start position:0% +equations use the stuffs all right and + + + align:start position:0% +equations use the stuffs all right and +there's special methods they're implicit + + align:start position:0% +there's special methods they're implicit + + + align:start position:0% +there's special methods they're implicit +methods and they're specialized solvers + + align:start position:0% +methods and they're specialized solvers + + + align:start position:0% +methods and they're specialized solvers +and what they do is they allow you to + + align:start position:0% +and what they do is they allow you to + + + align:start position:0% +and what they do is they allow you to +take larger time steps then you would be + + align:start position:0% +take larger time steps then you would be + + + align:start position:0% +take larger time steps then you would be +allowed to use with explicit methods + + align:start position:0% +allowed to use with explicit methods + + + align:start position:0% +allowed to use with explicit methods +where you'd run into numerical + + align:start position:0% +where you'd run into numerical + + + align:start position:0% +where you'd run into numerical +instabilities if you try to use explicit + + align:start position:0% +instabilities if you try to use explicit + + + align:start position:0% +instabilities if you try to use explicit +method with a big time stamp it's much + + align:start position:0% +method with a big time stamp it's much + + + align:start position:0% +method with a big time stamp it's much +bigger than the real physical time scale + + align:start position:0% +bigger than the real physical time scale + + + align:start position:0% +bigger than the real physical time scale +you'll get some crazy oscillation but if + + align:start position:0% +you'll get some crazy oscillation but if + + + align:start position:0% +you'll get some crazy oscillation but if +you use the stiff solvers you can get + + align:start position:0% +you use the stiff solvers you can get + + + align:start position:0% +you use the stiff solvers you can get +away with time such that are much much + + align:start position:0% +away with time such that are much much + + + align:start position:0% +away with time such that are much much +larger than the real physical scale so + + align:start position:0% +larger than the real physical scale so + + + align:start position:0% +larger than the real physical scale so +that allows you to go from 100 + + align:start position:0% +that allows you to go from 100 + + + align:start position:0% +that allows you to go from 100 +picoseconds up to maybe 100 nanoseconds + + align:start position:0% +picoseconds up to maybe 100 nanoseconds + + + align:start position:0% +picoseconds up to maybe 100 nanoseconds +get rid of three orders of magnitude of + + align:start position:0% +get rid of three orders of magnitude of + + + align:start position:0% +get rid of three orders of magnitude of +time step by using a sift solver so + + align:start position:0% +time step by using a sift solver so + + + align:start position:0% +time step by using a sift solver so +that's pretty good three orders + + align:start position:0% +that's pretty good three orders + + + align:start position:0% +that's pretty good three orders +magnitude reduction will go for it it's + + align:start position:0% +magnitude reduction will go for it it's + + + align:start position:0% +magnitude reduction will go for it it's +not only reducing the CPU time + + align:start position:0% +not only reducing the CPU time + + + align:start position:0% +not only reducing the CPU time +potentially but it's even more + + align:start position:0% +potentially but it's even more + + + align:start position:0% +potentially but it's even more +importantly reducing the number of + + align:start position:0% +importantly reducing the number of + + + align:start position:0% +importantly reducing the number of +points you have to save because when you + + align:start position:0% +points you have to save because when you + + + align:start position:0% +points you have to save because when you +run this calculation what Jacquelyn Chen + + align:start position:0% +run this calculation what Jacquelyn Chen + + + align:start position:0% +run this calculation what Jacquelyn Chen +ends up with is a list Y and every X met + + align:start position:0% +ends up with is a list Y and every X met + + + align:start position:0% +ends up with is a list Y and every X met +X X and I am that's that's the output of + + align:start position:0% +X X and I am that's that's the output of + + + align:start position:0% +X X and I am that's that's the output of +her program okay so how big is this + + align:start position:0% +her program okay so how big is this + + + align:start position:0% +her program okay so how big is this +object this is 200 + + align:start position:0% +object this is 200 + + + align:start position:0% +object this is 200 +times 10 to the fourth times boy thank + + align:start position:0% +times 10 to the fourth times boy thank + + + align:start position:0% +times 10 to the fourth times boy thank +Allah for gay right that's that's how + + align:start position:0% +Allah for gay right that's that's how + + + align:start position:0% +Allah for gay right that's that's how +many numbers she's gonna get out of her + + align:start position:0% +many numbers she's gonna get out of her + + + align:start position:0% +many numbers she's gonna get out of her +simulation so actually her biggest + + align:start position:0% +simulation so actually her biggest + + + align:start position:0% +simulation so actually her biggest +problem is not actually solving the + + align:start position:0% +problem is not actually solving the + + + align:start position:0% +problem is not actually solving the +simulation as long as she can get the + + align:start position:0% +simulation as long as she can get the + + + align:start position:0% +simulation as long as she can get the +one month two CPU time she's good she's + + align:start position:0% +one month two CPU time she's good she's + + + align:start position:0% +one month two CPU time she's good she's +got this all her problems had to analyze + + align:start position:0% +got this all her problems had to analyze + + + align:start position:0% +got this all her problems had to analyze +her data because she now she has this + + align:start position:0% +her data because she now she has this + + + align:start position:0% +her data because she now she has this +this much data that she has to figure + + align:start position:0% +this much data that she has to figure + + + align:start position:0% +this much data that she has to figure +out to say something rational about it + + align:start position:0% +out to say something rational about it + + + align:start position:0% +out to say something rational about it +and so she has like a whole army of + + align:start position:0% +and so she has like a whole army of + + + align:start position:0% +and so she has like a whole army of +postdocs whose whole job is trying to + + align:start position:0% +postdocs whose whole job is trying to + + + align:start position:0% +postdocs whose whole job is trying to +invent new data interrogation methods + + align:start position:0% +invent new data interrogation methods + + + align:start position:0% +invent new data interrogation methods +and also this dataset is so large it + + align:start position:0% +and also this dataset is so large it + + + align:start position:0% +and also this dataset is so large it +cannot be stored in a hard disk in fact + + align:start position:0% +cannot be stored in a hard disk in fact + + + align:start position:0% +cannot be stored in a hard disk in fact +he cannot be stored on the biggest + + align:start position:0% +he cannot be stored on the biggest + + + align:start position:0% +he cannot be stored on the biggest +Farmar today this so she has to as the + + align:start position:0% +Farmar today this so she has to as the + + + align:start position:0% +Farmar today this so she has to as the +calculators running sending the data to + + align:start position:0% +calculators running sending the data to + + + align:start position:0% +calculators running sending the data to +different forms of hard disks around the + + align:start position:0% +different forms of hard disks around the + + + align:start position:0% +different forms of hard disks around the +world and filling them completely up and + + align:start position:0% +world and filling them completely up and + + + align:start position:0% +world and filling them completely up and +then say to the next one filling them up + + align:start position:0% +then say to the next one filling them up + + + align:start position:0% +then say to the next one filling them up +so she has fragments of this data set + + align:start position:0% +so she has fragments of this data set + + + align:start position:0% +so she has fragments of this data set +steward all over the place and then she + + align:start position:0% +steward all over the place and then she + + + align:start position:0% +steward all over the place and then she +has to you have to what he could graph + + align:start position:0% +has to you have to what he could graph + + + align:start position:0% +has to you have to what he could graph +she has to like ten special graph + + align:start position:0% +she has to like ten special graph + + + align:start position:0% +she has to like ten special graph +software it looks inside this data farm + + align:start position:0% +software it looks inside this data farm + + + align:start position:0% +software it looks inside this data farm +get some numbers looks inside this data + + align:start position:0% +get some numbers looks inside this data + + + align:start position:0% +get some numbers looks inside this data +part and puts it all together in some + + align:start position:0% +part and puts it all together in some + + + align:start position:0% +part and puts it all together in some +way so that's a pretty hard project okay + + align:start position:0% +way so that's a pretty hard project okay + + + align:start position:0% +way so that's a pretty hard project okay +now if but if I can use a stiff solver I + + align:start position:0% +now if but if I can use a stiff solver I + + + align:start position:0% +now if but if I can use a stiff solver I +don't need to use so many time steps so + + align:start position:0% +don't need to use so many time steps so + + + align:start position:0% +don't need to use so many time steps so +if I can get this down to the fifth at + + align:start position:0% +if I can get this down to the fifth at + + + align:start position:0% +if I can get this down to the fifth at +least I got through the three orders of + + align:start position:0% +least I got through the three orders of + + + align:start position:0% +least I got through the three orders of +magnitude of my data right so now I just + + align:start position:0% +magnitude of my data right so now I just + + + align:start position:0% +magnitude of my data right so now I just +need one day to farm maybe instead of + + align:start position:0% +need one day to farm maybe instead of + + + align:start position:0% +need one day to farm maybe instead of +instead if I you know using all the ones + + align:start position:0% +instead if I you know using all the ones + + + align:start position:0% +instead if I you know using all the ones +that Amazon and Google Ellen or + + align:start position:0% +that Amazon and Google Ellen or + + + align:start position:0% +that Amazon and Google Ellen or +something ok so so this is a pretty big + + align:start position:0% +something ok so so this is a pretty big + + + align:start position:0% +something ok so so this is a pretty big +advantage to do it this way now the + + align:start position:0% +advantage to do it this way now the + + + align:start position:0% +advantage to do it this way now the +disadvantage as you know is solving + + align:start position:0% +disadvantage as you know is solving + + + align:start position:0% +disadvantage as you know is solving +implicit different equations is way more + + align:start position:0% +implicit different equations is way more + + + align:start position:0% +implicit different equations is way more +expensive right because you have to + + align:start position:0% +expensive right because you have to + + + align:start position:0% +expensive right because you have to +solve an implicit nonlinear algebraic + + align:start position:0% +solve an implicit nonlinear algebraic + + + align:start position:0% +solve an implicit nonlinear algebraic +equation at every time step and in this + + align:start position:0% +equation at every time step and in this + + + align:start position:0% +equation at every time step and in this +case it could be pretty complicated + + align:start position:0% +case it could be pretty complicated + + + align:start position:0% +case it could be pretty complicated +equation because if I have this many + + align:start position:0% +equation because if I have this many + + + align:start position:0% +equation because if I have this many +state variables so at 10 to the fourth + + align:start position:0% +state variables so at 10 to the fourth + + + align:start position:0% +state variables so at 10 to the fourth +times 10 to the 4 times 7 4 so 10 to the + + align:start position:0% +times 10 to the 4 times 7 4 so 10 to the + + + align:start position:0% +times 10 to the 4 times 7 4 so 10 to the +12 times 200 so 10 to the 14th at each + + align:start position:0% +12 times 200 so 10 to the 14th at each + + + align:start position:0% +12 times 200 so 10 to the 14th at each +time step that's my current state and + + align:start position:0% +time step that's my current state and + + + align:start position:0% +time step that's my current state and +I'm trying to solve a non-linear + + align:start position:0% +I'm trying to solve a non-linear + + + align:start position:0% +I'm trying to solve a non-linear +algebraic equation 10 to the 14th + + align:start position:0% +algebraic equation 10 to the 14th + + + align:start position:0% +algebraic equation 10 to the 14th +unknowns you need you need pretty good + + align:start position:0% +unknowns you need you need pretty good + + + align:start position:0% +unknowns you need you need pretty good +solver I mean I know backslash is good + + align:start position:0% +solver I mean I know backslash is good + + + align:start position:0% +solver I mean I know backslash is good +and you know solve this stuff but but I + + align:start position:0% +and you know solve this stuff but but I + + + align:start position:0% +and you know solve this stuff but but I +really don't think it's gonna work so + + align:start position:0% +really don't think it's gonna work so + + + align:start position:0% +really don't think it's gonna work so +that's a really serious problem so the + + align:start position:0% +that's a really serious problem so the + + + align:start position:0% +that's a really serious problem so the +next trick is to say ok well I only need + + align:start position:0% +next trick is to say ok well I only need + + + align:start position:0% +next trick is to say ok well I only need +the stiffness is only happening because + + align:start position:0% +the stiffness is only happening because + + + align:start position:0% +the stiffness is only happening because +of the chemistry so I don't I could + + align:start position:0% +of the chemistry so I don't I could + + + align:start position:0% +of the chemistry so I don't I could +solve all of the + + align:start position:0% +solve all of the + + + align:start position:0% +solve all of the +volumes separately so the idea is to + + align:start position:0% +volumes separately so the idea is to + + + align:start position:0% +volumes separately so the idea is to +split the problem up I'm going to solve + + align:start position:0% +split the problem up I'm going to solve + + + align:start position:0% +split the problem up I'm going to solve +the chemistry using a SIF solver only at + + align:start position:0% +the chemistry using a SIF solver only at + + + align:start position:0% +the chemistry using a SIF solver only at +one finite volume at a time and then I'm + + align:start position:0% +one finite volume at a time and then I'm + + + align:start position:0% +one finite volume at a time and then I'm +going to do the transport some other way + + align:start position:0% +going to do the transport some other way + + + align:start position:0% +going to do the transport some other way +so what I'm going to do is I'm going to + + align:start position:0% +so what I'm going to do is I'm going to + + + align:start position:0% +so what I'm going to do is I'm going to +rewrite this equation as my my unknowns + + align:start position:0% +rewrite this equation as my my unknowns + + + align:start position:0% +rewrite this equation as my my unknowns +dy DT is equal to some kind of transport + + align:start position:0% +dy DT is equal to some kind of transport + + + align:start position:0% +dy DT is equal to some kind of transport +term and sometimes reactive term and + + align:start position:0% +term and sometimes reactive term and + + + align:start position:0% +term and sometimes reactive term and +this term is local the oldest in this + + align:start position:0% +this term is local the oldest in this + + + align:start position:0% +this term is local the oldest in this +equation this is really saying dy at + + align:start position:0% +equation this is really saying dy at + + + align:start position:0% +equation this is really saying dy at +position X depends on this at position X + + align:start position:0% +position X depends on this at position X + + + align:start position:0% +position X depends on this at position X +whereas to compute these guys I need to + + align:start position:0% +whereas to compute these guys I need to + + + align:start position:0% +whereas to compute these guys I need to +do finite differences or something from + + align:start position:0% +do finite differences or something from + + + align:start position:0% +do finite differences or something from +adjoining kind of volumes right I have + + align:start position:0% +adjoining kind of volumes right I have + + + align:start position:0% +adjoining kind of volumes right I have +to do fluxes from the adjoining volumes + + align:start position:0% +to do fluxes from the adjoining volumes + + + align:start position:0% +to do fluxes from the adjoining volumes +so these guys are sensitive to not just + + align:start position:0% +so these guys are sensitive to not just + + + align:start position:0% +so these guys are sensitive to not just +to my local value of y at this finite + + align:start position:0% +to my local value of y at this finite + + + align:start position:0% +to my local value of y at this finite +volume but also to the neighboring + + align:start position:0% +volume but also to the neighboring + + + align:start position:0% +volume but also to the neighboring +values of Y but if I don't worry about + + align:start position:0% +values of Y but if I don't worry about + + + align:start position:0% +values of Y but if I don't worry about +them if I break it up I had this local + + align:start position:0% +them if I break it up I had this local + + + align:start position:0% +them if I break it up I had this local +thing and this non-local thing this one + + align:start position:0% +thing and this non-local thing this one + + + align:start position:0% +thing and this non-local thing this one +is local it's stiff this one is + + align:start position:0% +is local it's stiff this one is + + + align:start position:0% +is local it's stiff this one is +non-local but it's not so stiff and it's + + align:start position:0% +non-local but it's not so stiff and it's + + + align:start position:0% +non-local but it's not so stiff and it's +often it's linear or nearly linear + + align:start position:0% +often it's linear or nearly linear + + + align:start position:0% +often it's linear or nearly linear +here's the transport + + align:start position:0% +here's the transport + + + align:start position:0% +here's the transport +terms are mostly linear and so I can use + + align:start position:0% +terms are mostly linear and so I can use + + + align:start position:0% +terms are mostly linear and so I can use +I have specialized solvers that people + + align:start position:0% +I have specialized solvers that people + + + align:start position:0% +I have specialized solvers that people +have worked on for many years for each + + align:start position:0% +have worked on for many years for each + + + align:start position:0% +have worked on for many years for each +of these things so for this for the + + align:start position:0% +of these things so for this for the + + + align:start position:0% +of these things so for this for the +stiff thing I have things like OD 1 5 s + + align:start position:0% +stiff thing I have things like OD 1 5 s + + + align:start position:0% +stiff thing I have things like OD 1 5 s +I have Dae pack and - pack and docile + + align:start position:0% +I have Dae pack and - pack and docile + + + align:start position:0% +I have Dae pack and - pack and docile +and sundials and all those programs that + + align:start position:0% +and sundials and all those programs that + + + align:start position:0% +and sundials and all those programs that +people have written spend a lot of + + align:start position:0% +people have written spend a lot of + + + align:start position:0% +people have written spend a lot of +effort to solve this problem and + + align:start position:0% +effort to solve this problem and + + + align:start position:0% +effort to solve this problem and +similarly there's a whole bunch of + + align:start position:0% +similarly there's a whole bunch of + + + align:start position:0% +similarly there's a whole bunch of +people who spent their whole life trying + + align:start position:0% +people who spent their whole life trying + + + align:start position:0% +people who spent their whole life trying +to solve the convection diffusion + + align:start position:0% +to solve the convection diffusion + + + align:start position:0% +to solve the convection diffusion +problems the non-reacting flow problem + + align:start position:0% +problems the non-reacting flow problem + + + align:start position:0% +problems the non-reacting flow problem +and so I can use specialized solvers + + align:start position:0% +and so I can use specialized solvers + + + align:start position:0% +and so I can use specialized solvers +that they have so I want to split this + + align:start position:0% +that they have so I want to split this + + + align:start position:0% +that they have so I want to split this +up and what I really would like to solve + + align:start position:0% +up and what I really would like to solve + + + align:start position:0% +up and what I really would like to solve +which I'd prefer to solve dy DT equals R + + align:start position:0% +which I'd prefer to solve dy DT equals R + + + align:start position:0% +which I'd prefer to solve dy DT equals R +and dy DT equals T completely separately + + align:start position:0% +and dy DT equals T completely separately + + + align:start position:0% +and dy DT equals T completely separately +if I could because I can use specialized + + align:start position:0% +if I could because I can use specialized + + + align:start position:0% +if I could because I can use specialized +methods or the best for each so now to + + align:start position:0% +methods or the best for each so now to + + + align:start position:0% +methods or the best for each so now to +figure out well this is not really the + + align:start position:0% +figure out well this is not really the + + + align:start position:0% +figure out well this is not really the +real equation because it has both I've + + align:start position:0% +real equation because it has both I've + + + align:start position:0% +real equation because it has both I've +added together how can I handle that so + + align:start position:0% +added together how can I handle that so + + + align:start position:0% +added together how can I handle that so +this operator splitting recipe is solve + + align:start position:0% +this operator splitting recipe is solve + + + align:start position:0% +this operator splitting recipe is solve +dy DT equals 2t for a while and at the + + align:start position:0% +dy DT equals 2t for a while and at the + + + align:start position:0% +dy DT equals 2t for a while and at the +end of this process I'll have y ax t + + align:start position:0% +end of this process I'll have y ax t + + + align:start position:0% +end of this process I'll have y ax t +final and then and so I'm sorry solve + + align:start position:0% +final and then and so I'm sorry solve + + + align:start position:0% +final and then and so I'm sorry solve +this equation with y people going on + + align:start position:0% +this equation with y people going on + + + align:start position:0% +this equation with y people going on +it's the equation system solving + + align:start position:0% +it's the equation system solving + + + align:start position:0% +it's the equation system solving +transport I do some transport for a + + align:start position:0% +transport I do some transport for a + + + align:start position:0% +transport I do some transport for a +while I get some values to the Y then I + + align:start position:0% +while I get some values to the Y then I + + + align:start position:0% +while I get some values to the Y then I +take these guys and I saw the reaction + + align:start position:0% +take these guys and I saw the reaction + + + align:start position:0% +take these guys and I saw the reaction +equation starting from y equals y final + + align:start position:0% +equation starting from y equals y final + + + align:start position:0% +equation starting from y equals y final +array this my duties here okay and I + + align:start position:0% +array this my duties here okay and I + + + align:start position:0% +array this my duties here okay and I +solve this one for a while and I'll get + + align:start position:0% +solve this one for a while and I'll get + + + align:start position:0% +solve this one for a while and I'll get +a different different y y q final + + align:start position:0% + + + + align:start position:0% + +alright and this is simple anything says + + align:start position:0% +alright and this is simple anything says + + + align:start position:0% +alright and this is simple anything says +just keep going back and forth boom boom + + align:start position:0% +just keep going back and forth boom boom + + + align:start position:0% +just keep going back and forth boom boom +boom boom boom boom boom boom and in the + + align:start position:0% +boom boom boom boom boom boom and in the + + + align:start position:0% +boom boom boom boom boom boom and in the +limit where I make this T final minus T + + align:start position:0% +limit where I make this T final minus T + + + align:start position:0% +limit where I make this T final minus T +naught to be very small then maybe I + + align:start position:0% +naught to be very small then maybe I + + + align:start position:0% +naught to be very small then maybe I +might expect that they might converge + + align:start position:0% +might expect that they might converge + + + align:start position:0% +might expect that they might converge +the same solution as two as a couple of + + align:start position:0% +the same solution as two as a couple of + + + align:start position:0% +the same solution as two as a couple of +equations alright so that's the concept + + align:start position:0% +equations alright so that's the concept + + + align:start position:0% +equations alright so that's the concept +now if you do it this way it doesn't + + align:start position:0% +now if you do it this way it doesn't + + + align:start position:0% +now if you do it this way it doesn't +work very well + + align:start position:0% +work very well + + + align:start position:0% +work very well +your you need to make the this delta T + + align:start position:0% +your you need to make the this delta T + + + align:start position:0% +your you need to make the this delta T +incredibly small to get any accuracy + + align:start position:0% +incredibly small to get any accuracy + + + align:start position:0% +incredibly small to get any accuracy +however you can do a slightly more + + align:start position:0% +however you can do a slightly more + + + align:start position:0% +however you can do a slightly more +clever version which is I solve dy DT + + align:start position:0% +clever version which is I solve dy DT + + + align:start position:0% +clever version which is I solve dy DT +equals 2t starting from YT not going on + + align:start position:0% +equals 2t starting from YT not going on + + + align:start position:0% +equals 2t starting from YT not going on +and I saw this to give me Y at T plus + + align:start position:0% +and I saw this to give me Y at T plus + + + align:start position:0% +and I saw this to give me Y at T plus +delta T over 2 then I solve dy DT is + + align:start position:0% +delta T over 2 then I solve dy DT is + + + align:start position:0% +delta T over 2 then I solve dy DT is +equal to our starting from Y of T not + + align:start position:0% +equal to our starting from Y of T not + + + align:start position:0% +equal to our starting from Y of T not +equal to Y star + + align:start position:0% +equal to Y star + + + align:start position:0% +equal to Y star +my star and this I integrate out to Y of + + align:start position:0% +my star and this I integrate out to Y of + + + align:start position:0% +my star and this I integrate out to Y of +T plus the full delta T I'll call that Y + + align:start position:0% +T plus the full delta T I'll call that Y + + + align:start position:0% +T plus the full delta T I'll call that Y +double star + + align:start position:0% +double star + + + align:start position:0% +double star +and then I solve this one again and I + + align:start position:0% +and then I solve this one again and I + + + align:start position:0% +and then I solve this one again and I +solve + + align:start position:0% +solve + + + align:start position:0% +solve +starting from wife Tina equals two y + + align:start position:0% +starting from wife Tina equals two y + + + align:start position:0% +starting from wife Tina equals two y +double star and I integrate that out for + + align:start position:0% +double star and I integrate that out for + + + align:start position:0% +double star and I integrate that out for +another delta T over two and this one I + + align:start position:0% +another delta T over two and this one I + + + align:start position:0% +another delta T over two and this one I +called my wife final and that's the one + + align:start position:0% +called my wife final and that's the one + + + align:start position:0% +called my wife final and that's the one +I use so I take a half of a transport + + align:start position:0% +I use so I take a half of a transport + + + align:start position:0% +I use so I take a half of a transport +step sort of like I'm starting to do the + + align:start position:0% +step sort of like I'm starting to do the + + + align:start position:0% +step sort of like I'm starting to do the +transport then I sell you know hold on I + + align:start position:0% +transport then I sell you know hold on I + + + align:start position:0% +transport then I sell you know hold on I +got to my reactions if I do my reaction + + align:start position:0% +got to my reactions if I do my reaction + + + align:start position:0% +got to my reactions if I do my reaction +then I do the other half the transport + + align:start position:0% +then I do the other half the transport + + + align:start position:0% +then I do the other half the transport +after that and you can do the analysis + + align:start position:0% +after that and you can do the analysis + + + align:start position:0% +after that and you can do the analysis +of this it turns out this thing + + align:start position:0% +of this it turns out this thing + + + align:start position:0% +of this it turns out this thing +converges to the true solution of the + + align:start position:0% +converges to the true solution of the + + + align:start position:0% +converges to the true solution of the +coupled equations with second-order + + align:start position:0% +coupled equations with second-order + + + align:start position:0% +coupled equations with second-order +accuracy so it might make this delta T + + align:start position:0% +accuracy so it might make this delta T + + + align:start position:0% +accuracy so it might make this delta T +if I cut it in half + + align:start position:0% +if I cut it in half + + + align:start position:0% +if I cut it in half +the precision increases by a factor for + + align:start position:0% +the precision increases by a factor for + + + align:start position:0% +the precision increases by a factor for +my kind of by factor 10 increase by a + + align:start position:0% +my kind of by factor 10 increase by a + + + align:start position:0% +my kind of by factor 10 increase by a +factor of 100 so this is looking more + + align:start position:0% +factor of 100 so this is looking more + + + align:start position:0% +factor of 100 so this is looking more +promising as a way to do it this is the + + align:start position:0% +promising as a way to do it this is the + + + align:start position:0% +promising as a way to do it this is the +most popular way to do it so this recipe + + align:start position:0% +most popular way to do it so this recipe + + + align:start position:0% +most popular way to do it so this recipe +here for operator splitting + + align:start position:0% +here for operator splitting + + + align:start position:0% +here for operator splitting +it's called Strang splitting named after + + align:start position:0% +it's called Strang splitting named after + + + align:start position:0% +it's called Strang splitting named after +Gil Strang who's a professor in the + + align:start position:0% +Gil Strang who's a professor in the + + + align:start position:0% +Gil Strang who's a professor in the +applied mathematics department here + + align:start position:0% +applied mathematics department here + + + align:start position:0% +applied mathematics department here +former head of Siam the international + + align:start position:0% +former head of Siam the international + + + align:start position:0% +former head of Siam the international +body for Applied Mathematics and also + + align:start position:0% +body for Applied Mathematics and also + + + align:start position:0% +body for Applied Mathematics and also +author of fantastically great linear + + align:start position:0% +author of fantastically great linear + + + align:start position:0% +author of fantastically great linear +algebra textbook which maybe some of you + + align:start position:0% +algebra textbook which maybe some of you + + + align:start position:0% +algebra textbook which maybe some of you +guys I've seen some videos of his so he + + align:start position:0% +guys I've seen some videos of his so he + + + align:start position:0% +guys I've seen some videos of his so he +invented this 1968 I was 5 years old + + align:start position:0% +invented this 1968 I was 5 years old + + + align:start position:0% +invented this 1968 I was 5 years old +yeah he didn't know that his invention + + align:start position:0% +yeah he didn't know that his invention + + + align:start position:0% +yeah he didn't know that his invention +was of any practical use being a + + align:start position:0% +was of any practical use being a + + + align:start position:0% +was of any practical use being a +mathematician so he just publish that + + align:start position:0% +mathematician so he just publish that + + + align:start position:0% +mathematician so he just publish that +paper now in the meantime this paper is + + align:start position:0% +paper now in the meantime this paper is + + + align:start position:0% +paper now in the meantime this paper is +like a citation classic it's like + + align:start position:0% +like a citation classic it's like + + + align:start position:0% +like a citation classic it's like +silently I don't know 20 thousand times + + align:start position:0% +silently I don't know 20 thousand times + + + align:start position:0% +silently I don't know 20 thousand times +he had no idea he never looks at + + align:start position:0% +he had no idea he never looks at + + + align:start position:0% +he had no idea he never looks at +citation list he's a mathematician so so + + align:start position:0% +citation list he's a mathematician so so + + + align:start position:0% +citation list he's a mathematician so so +I was working on this problem and let's + + align:start position:0% +I was working on this problem and let's + + + align:start position:0% +I was working on this problem and let's +see let's back up so we just how they + + align:start position:0% +see let's back up so we just how they + + + align:start position:0% +see let's back up so we just how they +usually solve right we usually solve the + + align:start position:0% +usually solve right we usually solve the + + + align:start position:0% +usually solve right we usually solve the +problems the operator splitting sir + + align:start position:0% + + + + align:start position:0% + +and when we we'd like to solve it this + + align:start position:0% +and when we we'd like to solve it this + + + align:start position:0% +and when we we'd like to solve it this +way because I can use specialized + + align:start position:0% +way because I can use specialized + + + align:start position:0% +way because I can use specialized +solvers I use a transport solver here I + + align:start position:0% +solvers I use a transport solver here I + + + align:start position:0% +solvers I use a transport solver here I +use the stiff solver here this one I can + + align:start position:0% +use the stiff solver here this one I can + + + align:start position:0% +use the stiff solver here this one I can +paralyze because I can do a different OD + + align:start position:0% +paralyze because I can do a different OD + + + align:start position:0% +paralyze because I can do a different OD +solution at each finite volume so if I + + align:start position:0% +solution at each finite volume so if I + + + align:start position:0% +solution at each finite volume so if I +have a big computer a big parallel + + align:start position:0% +have a big computer a big parallel + + + align:start position:0% +have a big computer a big parallel +computer say have 10,000 nodes I can + + align:start position:0% +computer say have 10,000 nodes I can + + + align:start position:0% +computer say have 10,000 nodes I can +solve 10,000 finite volume + + align:start position:0% +solve 10,000 finite volume + + + align:start position:0% +solve 10,000 finite volume +simultaneously in this step so the CPU + + align:start position:0% +simultaneously in this step so the CPU + + + align:start position:0% +simultaneously in this step so the CPU +time is reduced a lot so parallel lines + + align:start position:0% +time is reduced a lot so parallel lines + + + align:start position:0% +time is reduced a lot so parallel lines +is easily so this is this is really + + align:start position:0% +is easily so this is this is really + + + align:start position:0% +is easily so this is this is really +popular this is the main way that people + + align:start position:0% +popular this is the main way that people + + + align:start position:0% +popular this is the main way that people +do do things and then in the ideal case + + align:start position:0% +do do things and then in the ideal case + + + align:start position:0% +do do things and then in the ideal case +you do it with a certain guess of TT + + align:start position:0% +you do it with a certain guess of TT + + + align:start position:0% +you do it with a certain guess of TT +then you try TT divided by 5 and if you + + align:start position:0% +then you try TT divided by 5 and if you + + + align:start position:0% +then you try TT divided by 5 and if you +get the same result then you publish it + + align:start position:0% +get the same result then you publish it + + + align:start position:0% +get the same result then you publish it +ok and you think you've converted your + + align:start position:0% +ok and you think you've converted your + + + align:start position:0% +ok and you think you've converted your +solution however what I've what I found + + align:start position:0% +solution however what I've what I found + + + align:start position:0% +solution however what I've what I found +doing this is I was trying to find + + align:start position:0% +doing this is I was trying to find + + + align:start position:0% +doing this is I was trying to find +flames I'm trying to calculate the + + align:start position:0% +flames I'm trying to calculate the + + + align:start position:0% +flames I'm trying to calculate the +positions of flames and what I found was + + align:start position:0% +positions of flames and what I found was + + + align:start position:0% +positions of flames and what I found was +that with the Delta T's I would try + + align:start position:0% +that with the Delta T's I would try + + + align:start position:0% +that with the Delta T's I would try +sometimes I would get a qualitatively + + align:start position:0% +sometimes I would get a qualitatively + + + align:start position:0% +sometimes I would get a qualitatively +different solution depending on the + + align:start position:0% +different solution depending on the + + + align:start position:0% +different solution depending on the +delta T I chose and so in particular + + align:start position:0% +delta T I chose and so in particular + + + align:start position:0% +delta T I chose and so in particular +what I found was that I was solving + + align:start position:0% +what I found was that I was solving + + + align:start position:0% +what I found was that I was solving +burner flames so I have like a burner + + align:start position:0% +burner flames so I have like a burner + + + align:start position:0% +burner flames so I have like a burner +here flame on top of it like this and + + align:start position:0% +here flame on top of it like this and + + + align:start position:0% +here flame on top of it like this and +there's two importantly different cases + + align:start position:0% +there's two importantly different cases + + + align:start position:0% +there's two importantly different cases +one is where the flame is floating above + + align:start position:0% +one is where the flame is floating above + + + align:start position:0% +one is where the flame is floating above +the burner and one is where the flame + + align:start position:0% +the burner and one is where the flame + + + align:start position:0% +the burner and one is where the flame +kind of goes all the way down and + + align:start position:0% +kind of goes all the way down and + + + align:start position:0% +kind of goes all the way down and +touches the metal and you've probably + + align:start position:0% +touches the metal and you've probably + + + align:start position:0% +touches the metal and you've probably +seen both this case a bunch of burner or + + align:start position:0% +seen both this case a bunch of burner or + + + align:start position:0% +seen both this case a bunch of burner or +something like that sometimes if you get + + align:start position:0% +something like that sometimes if you get + + + align:start position:0% +something like that sometimes if you get +the flow rates high enough the whole + + align:start position:0% +the flow rates high enough the whole + + + align:start position:0% +the flow rates high enough the whole +thing will lift off and be floating + + align:start position:0% +thing will lift off and be floating + + + align:start position:0% +thing will lift off and be floating +there and sometimes if you slow the flow + + align:start position:0% +there and sometimes if you slow the flow + + + align:start position:0% +there and sometimes if you slow the flow +rates down the wood they say that the + + align:start position:0% +rates down the wood they say that the + + + align:start position:0% +rates down the wood they say that the +flame will anchor to to the metal some + + align:start position:0% +flame will anchor to to the metal some + + + align:start position:0% +flame will anchor to to the metal some +piece of the flame actually touch the + + align:start position:0% +piece of the flame actually touch the + + + align:start position:0% +piece of the flame actually touch the +metal usually it's like if you have a + + align:start position:0% +metal usually it's like if you have a + + + align:start position:0% +metal usually it's like if you have a +one time you have a case like this you + + align:start position:0% +one time you have a case like this you + + + align:start position:0% +one time you have a case like this you +have like a metal piece metal piece + + align:start position:0% +have like a metal piece metal piece + + + align:start position:0% +have like a metal piece metal piece +here's your mixture coming in out here's + + align:start position:0% +here's your mixture coming in out here's + + + align:start position:0% +here's your mixture coming in out here's +the air and a lot of times the flame + + align:start position:0% +the air and a lot of times the flame + + + align:start position:0% +the air and a lot of times the flame +will come and touch it'll actually touch + + align:start position:0% +will come and touch it'll actually touch + + + align:start position:0% +will come and touch it'll actually touch +this metal piece here you know a flame + + align:start position:0% +this metal piece here you know a flame + + + align:start position:0% +this metal piece here you know a flame +looks sort of like that + + align:start position:0% +looks sort of like that + + + align:start position:0% +looks sort of like that +have you ever see a flame with this + + align:start position:0% +have you ever see a flame with this + + + align:start position:0% +have you ever see a flame with this +anyway this is a common thing anchor + + align:start position:0% +anyway this is a common thing anchor + + + align:start position:0% +anyway this is a common thing anchor +plane if you just have a slow a slow + + align:start position:0% +plane if you just have a slow a slow + + + align:start position:0% +plane if you just have a slow a slow +speed burner that's what you got you go + + align:start position:0% +speed burner that's what you got you go + + + align:start position:0% +speed burner that's what you got you go +high to speed new burner you make the + + align:start position:0% +high to speed new burner you make the + + + align:start position:0% +high to speed new burner you make the +whole thing lift up and sort of dance + + align:start position:0% +whole thing lift up and sort of dance + + + align:start position:0% +whole thing lift up and sort of dance +around if you look at the flame alright + + align:start position:0% +around if you look at the flame alright + + + align:start position:0% +around if you look at the flame alright +I Pisces same you look at a piece of + + align:start position:0% +I Pisces same you look at a piece of + + + align:start position:0% +I Pisces same you look at a piece of +wood burning + + align:start position:0% +wood burning + + + align:start position:0% +wood burning +if it was burning well the flame we + + align:start position:0% +if it was burning well the flame we + + + align:start position:0% +if it was burning well the flame we +lifted off the wood you'll see a gap + + align:start position:0% +lifted off the wood you'll see a gap + + + align:start position:0% +lifted off the wood you'll see a gap +between the flame and the wood if it's + + align:start position:0% +between the flame and the wood if it's + + + align:start position:0% +between the flame and the wood if it's +not burning that while you can see the + + align:start position:0% +not burning that while you can see the + + + align:start position:0% +not burning that while you can see the +flame bit bit so if I'm actually touch + + align:start position:0% +flame bit bit so if I'm actually touch + + + align:start position:0% +flame bit bit so if I'm actually touch +the pieces of wood okay so that's a very + + align:start position:0% +the pieces of wood okay so that's a very + + + align:start position:0% +the pieces of wood okay so that's a very +important thing for a combustion guy so + + align:start position:0% +important thing for a combustion guy so + + + align:start position:0% +important thing for a combustion guy so +I was really to me this is a big deal so + + align:start position:0% +I was really to me this is a big deal so + + + align:start position:0% +I was really to me this is a big deal so +when I solved it with one choice at TT I + + align:start position:0% +when I solved it with one choice at TT I + + + align:start position:0% +when I solved it with one choice at TT I +get this solution when I saw it with + + align:start position:0% +get this solution when I saw it with + + + align:start position:0% +get this solution when I saw it with +another choice of delta T I get this + + align:start position:0% +another choice of delta T I get this + + + align:start position:0% +another choice of delta T I get this +solution with a nice big gap now they + + align:start position:0% +solution with a nice big gap now they + + + align:start position:0% +solution with a nice big gap now they +both can't be right and so I was a + + align:start position:0% +both can't be right and so I was a + + + align:start position:0% +both can't be right and so I was a +little alarmed because it's like it's + + align:start position:0% +little alarmed because it's like it's + + + align:start position:0% +little alarmed because it's like it's +really different right + + align:start position:0% +really different right + + + align:start position:0% +really different right +so I thought like you know I didn't + + align:start position:0% +so I thought like you know I didn't + + + align:start position:0% +so I thought like you know I didn't +really care that much about the dynamics + + align:start position:0% +really care that much about the dynamics + + + align:start position:0% +really care that much about the dynamics +and my problem I just wanted to make + + align:start position:0% +and my problem I just wanted to make + + + align:start position:0% +and my problem I just wanted to make +sure that the steady-state flame I ended + + align:start position:0% +sure that the steady-state flame I ended + + + align:start position:0% +sure that the steady-state flame I ended +up with was the right one so if you're + + align:start position:0% +up with was the right one so if you're + + + align:start position:0% +up with was the right one so if you're +interested in steady state problems this + + align:start position:0% +interested in steady state problems this + + + align:start position:0% +interested in steady state problems this +is a really important thing you want to + + align:start position:0% +is a really important thing you want to + + + align:start position:0% +is a really important thing you want to +make sure that your solution really + + align:start position:0% +make sure that your solution really + + + align:start position:0% +make sure that your solution really +converges to the true steady state so + + align:start position:0% +converges to the true steady state so + + + align:start position:0% +converges to the true steady state so +when I demonstrate experimentally is + + align:start position:0% +when I demonstrate experimentally is + + + align:start position:0% +when I demonstrate experimentally is +this trying splitting method does not is + + align:start position:0% +this trying splitting method does not is + + + align:start position:0% +this trying splitting method does not is +not reliable to converge the safe state + + align:start position:0% +not reliable to converge the safe state + + + align:start position:0% +not reliable to converge the safe state +now I believe I made the delta T tiny + + align:start position:0% +now I believe I made the delta T tiny + + + align:start position:0% +now I believe I made the delta T tiny +enough probably I would converge to the + + align:start position:0% +enough probably I would converge to the + + + align:start position:0% +enough probably I would converge to the +cry steady-state but I don't know how + + align:start position:0% +cry steady-state but I don't know how + + + align:start position:0% +cry steady-state but I don't know how +tiny you have to go and I can't really + + align:start position:0% +tiny you have to go and I can't really + + + align:start position:0% +tiny you have to go and I can't really +judge my convergence criteria very well + + align:start position:0% +judge my convergence criteria very well + + + align:start position:0% +judge my convergence criteria very well +because at some point adult he suddenly + + align:start position:0% +because at some point adult he suddenly + + + align:start position:0% +because at some point adult he suddenly +jumps from one solution to another + + align:start position:0% +jumps from one solution to another + + + align:start position:0% +jumps from one solution to another +solution that's qualitatively completely + + align:start position:0% +solution that's qualitatively completely + + + align:start position:0% +solution that's qualitatively completely +different and so that the convergence is + + align:start position:0% +different and so that the convergence is + + + align:start position:0% +different and so that the convergence is +not smooth and continuous it's like it's + + align:start position:0% +not smooth and continuous it's like it's + + + align:start position:0% +not smooth and continuous it's like it's +converging converging diverging jumps + + align:start position:0% +converging converging diverging jumps + + + align:start position:0% +converging converging diverging jumps +just have the other solution and I don't + + align:start position:0% +just have the other solution and I don't + + + align:start position:0% +just have the other solution and I don't +know where the jump happens and I don't + + align:start position:0% +know where the jump happens and I don't + + + align:start position:0% +know where the jump happens and I don't +know if I keep going further we'll jump + + align:start position:0% +know if I keep going further we'll jump + + + align:start position:0% +know if I keep going further we'll jump +to something else so this makes me very + + align:start position:0% +to something else so this makes me very + + + align:start position:0% +to something else so this makes me very +loath to publish the paper right so I + + align:start position:0% +loath to publish the paper right so I + + + align:start position:0% +loath to publish the paper right so I +don't know so so I would say I just take + + align:start position:0% +don't know so so I would say I just take + + + align:start position:0% +don't know so so I would say I just take +my dad so I started working on trying to + + align:start position:0% +my dad so I started working on trying to + + + align:start position:0% +my dad so I started working on trying to +fix this splitting the problem was this + + align:start position:0% +fix this splitting the problem was this + + + align:start position:0% +fix this splitting the problem was this +trying is really smart so this his + + align:start position:0% +trying is really smart so this his + + + align:start position:0% +trying is really smart so this his +splitting method is really good it's + + align:start position:0% +splitting method is really good it's + + + align:start position:0% +splitting method is really good it's +stable it's it's pretty accurate it's + + align:start position:0% +stable it's it's pretty accurate it's + + + align:start position:0% +stable it's it's pretty accurate it's +really hard to beat it actually and so I + + align:start position:0% +really hard to beat it actually and so I + + + align:start position:0% +really hard to beat it actually and so I +publish the papers and they weren't that + + align:start position:0% +publish the papers and they weren't that + + + align:start position:0% +publish the papers and they weren't that +good because they really didn't really + + align:start position:0% +good because they really didn't really + + + align:start position:0% +good because they really didn't really +improve it that much but then I had a + + align:start position:0% +improve it that much but then I had a + + + align:start position:0% +improve it that much but then I had a +really smart postdoc named Grace Beth + + align:start position:0% +really smart postdoc named Grace Beth + + + align:start position:0% +really smart postdoc named Grace Beth +now works in the arrow Astro Department + + align:start position:0% +now works in the arrow Astro Department + + + align:start position:0% +now works in the arrow Astro Department +and he came up with a different way to + + align:start position:0% +and he came up with a different way to + + + align:start position:0% +and he came up with a different way to +look at this and he said you know if I + + align:start position:0% +look at this and he said you know if I + + + align:start position:0% +look at this and he said you know if I +have a problem that's like this I can + + align:start position:0% +have a problem that's like this I can + + + align:start position:0% +have a problem that's like this I can +always add some constant to this and + + align:start position:0% +always add some constant to this and + + + align:start position:0% +always add some constant to this and +subtract the same constant from this and + + align:start position:0% +subtract the same constant from this and + + + align:start position:0% +subtract the same constant from this and +I'm really getting the same problem and + + align:start position:0% +I'm really getting the same problem and + + + align:start position:0% +I'm really getting the same problem and +so now the thing is can I cleverly + + align:start position:0% +so now the thing is can I cleverly + + + align:start position:0% +so now the thing is can I cleverly +choose this constant so that for example + + align:start position:0% +choose this constant so that for example + + + align:start position:0% +choose this constant so that for example +my steady-state solution is going to be + + align:start position:0% +my steady-state solution is going to be + + + align:start position:0% +my steady-state solution is going to be +good so how to figure out what cost us + + align:start position:0% +good so how to figure out what cost us + + + align:start position:0% +good so how to figure out what cost us +to choose + + align:start position:0% +to choose + + + align:start position:0% +to choose +and so the methods where you add these + + align:start position:0% +and so the methods where you add these + + + align:start position:0% +and so the methods where you add these +constants are called balancing methods + + align:start position:0% +constants are called balancing methods + + + align:start position:0% +constants are called balancing methods +so he's trying to balance the operator + + align:start position:0% +so he's trying to balance the operator + + + align:start position:0% +so he's trying to balance the operator +splitting scheme and what raise method + + align:start position:0% + + + + align:start position:0% + +very simple bath balancing method this + + align:start position:0% +very simple bath balancing method this + + + align:start position:0% +very simple bath balancing method this +is called simple balancing there we go + + align:start position:0% +is called simple balancing there we go + + + align:start position:0% +is called simple balancing there we go +here we go simple balancing you choose + + align:start position:0% +here we go simple balancing you choose + + + align:start position:0% +here we go simple balancing you choose +to see to be the average of your right + + align:start position:0% +to see to be the average of your right + + + align:start position:0% +to see to be the average of your right +hand side at the last the previous time + + align:start position:0% +hand side at the last the previous time + + + align:start position:0% +hand side at the last the previous time +step + + align:start position:0% +step + + + align:start position:0% +step +okay now the idea here is as you're + + align:start position:0% +okay now the idea here is as you're + + + align:start position:0% +okay now the idea here is as you're +getting close to a steady-state the + + align:start position:0% +getting close to a steady-state the + + + align:start position:0% +getting close to a steady-state the +previous time step is not gonna be that + + align:start position:0% +previous time step is not gonna be that + + + align:start position:0% +previous time step is not gonna be that +much different than the current time + + align:start position:0% +much different than the current time + + + align:start position:0% +much different than the current time +step and so this average number is gonna + + align:start position:0% +step and so this average number is gonna + + + align:start position:0% +step and so this average number is gonna +stay more or less steady as you as you + + align:start position:0% +stay more or less steady as you as you + + + align:start position:0% +stay more or less steady as you as you +get close and so what you're really + + align:start position:0% +get close and so what you're really + + + align:start position:0% +get close and so what you're really +doing is adding the sort of the average + + align:start position:0% +doing is adding the sort of the average + + + align:start position:0% +doing is adding the sort of the average +of these two guys to each of them from + + align:start position:0% +of these two guys to each of them from + + + align:start position:0% +of these two guys to each of them from +the previous step and that has the + + align:start position:0% +the previous step and that has the + + + align:start position:0% +the previous step and that has the +consequence of really changing the + + align:start position:0% +consequence of really changing the + + + align:start position:0% +consequence of really changing the +solution so let me just show you so the + + align:start position:0% +solution so let me just show you so the + + + align:start position:0% +solution so let me just show you so the +left-hand side is what strengths + + align:start position:0% +left-hand side is what strengths + + + align:start position:0% +left-hand side is what strengths +splitting does + + align:start position:0% +splitting does + + + align:start position:0% +splitting does +it's the blue steps are the the blue + + align:start position:0% +it's the blue steps are the the blue + + + align:start position:0% +it's the blue steps are the the blue +steps are the transport and the green + + align:start position:0% +steps are the transport and the green + + + align:start position:0% +steps are the transport and the green +steps are the reaction and what's + + align:start position:0% +steps are the reaction and what's + + + align:start position:0% +steps are the reaction and what's +happening is I did a half a transport + + align:start position:0% +happening is I did a half a transport + + + align:start position:0% +happening is I did a half a transport +staff then I do a reaction the reaction + + align:start position:0% +staff then I do a reaction the reaction + + + align:start position:0% +staff then I do a reaction the reaction +sort of jumps me off the trajectory then + + align:start position:0% +sort of jumps me off the trajectory then + + + align:start position:0% +sort of jumps me off the trajectory then +brings me back when the trajectory then + + align:start position:0% +brings me back when the trajectory then + + + align:start position:0% +brings me back when the trajectory then +overshoots because I do a whole delta T + + align:start position:0% +overshoots because I do a whole delta T + + + align:start position:0% +overshoots because I do a whole delta T +step of reaction and then I have to do a + + align:start position:0% +step of reaction and then I have to do a + + + align:start position:0% +step of reaction and then I have to do a +half step of transport back and so I get + + align:start position:0% +half step of transport back and so I get + + + align:start position:0% +half step of transport back and so I get +from the black one black dot is the + + align:start position:0% +from the black one black dot is the + + + align:start position:0% +from the black one black dot is the +first point and the other black dot is + + align:start position:0% +first point and the other black dot is + + + align:start position:0% +first point and the other black dot is +thickness is what I call my final and + + align:start position:0% +thickness is what I call my final and + + + align:start position:0% +thickness is what I call my final and +that's showing what happens and it just + + align:start position:0% +that's showing what happens and it just + + + align:start position:0% +that's showing what happens and it just +repeats like that over and over again is + + align:start position:0% +repeats like that over and over again is + + + align:start position:0% +repeats like that over and over again is +and it makes sense you if you're close + + align:start position:0% +and it makes sense you if you're close + + + align:start position:0% +and it makes sense you if you're close +to steady-state then if you if I just + + align:start position:0% +to steady-state then if you if I just + + + align:start position:0% +to steady-state then if you if I just +take one of these terms without the + + align:start position:0% +take one of these terms without the + + + align:start position:0% +take one of these terms without the +balancing state of transport it's going + + align:start position:0% +balancing state of transport it's going + + + align:start position:0% +balancing state of transport it's going +to head away from steady state because + + align:start position:0% +to head away from steady state because + + + align:start position:0% +to head away from steady state because +it's + + align:start position:0% +it's + + + align:start position:0% +it's +the transport and the reef and the + + align:start position:0% +the transport and the reef and the + + + align:start position:0% +the transport and the reef and the +reaction are balancing against each + + align:start position:0% +reaction are balancing against each + + + align:start position:0% +reaction are balancing against each +other typically you have something + + align:start position:0% +other typically you have something + + + align:start position:0% +other typically you have something +transporting in and is being consumed by + + align:start position:0% +transporting in and is being consumed by + + + align:start position:0% +transporting in and is being consumed by +the reaction we're son is being created + + align:start position:0% +the reaction we're son is being created + + + align:start position:0% +the reaction we're son is being created +by reaction that's being transporting + + align:start position:0% +by reaction that's being transporting + + + align:start position:0% +by reaction that's being transporting +away and they have opposite signs + + align:start position:0% +away and they have opposite signs + + + align:start position:0% +away and they have opposite signs +if I only put one in that has a certain + + align:start position:0% +if I only put one in that has a certain + + + align:start position:0% +if I only put one in that has a certain +sign then I'm going to move away from + + align:start position:0% +sign then I'm going to move away from + + + align:start position:0% +sign then I'm going to move away from +the steady state and then I need the + + align:start position:0% +the steady state and then I need the + + + align:start position:0% +the steady state and then I need the +other one to bring it back and the + + align:start position:0% +other one to bring it back and the + + + align:start position:0% +other one to bring it back and the +reason why is transporting has trouble + + align:start position:0% +reason why is transporting has trouble + + + align:start position:0% +reason why is transporting has trouble +is it's trying to do these it seen these + + align:start position:0% +is it's trying to do these it seen these + + + align:start position:0% +is it's trying to do these it seen these +huge excursions away from the steady + + align:start position:0% +huge excursions away from the steady + + + align:start position:0% +huge excursions away from the steady +state at each time step with the hope + + align:start position:0% +state at each time step with the hope + + + align:start position:0% +state at each time step with the hope +that it ends up back at this a steam + + align:start position:0% +that it ends up back at this a steam + + + align:start position:0% +that it ends up back at this a steam +right that's the that's always supposed + + align:start position:0% +right that's the that's always supposed + + + align:start position:0% +right that's the that's always supposed +to work out and to second order it does + + align:start position:0% +to work out and to second order it does + + + align:start position:0% +to work out and to second order it does +this because it's pretty clever about + + align:start position:0% +this because it's pretty clever about + + + align:start position:0% +this because it's pretty clever about +how it works but it does it's crazy + + align:start position:0% +how it works but it does it's crazy + + + align:start position:0% +how it works but it does it's crazy +excursions now if you have a nonlinear + + align:start position:0% +excursions now if you have a nonlinear + + + align:start position:0% +excursions now if you have a nonlinear +model the further you excursions from + + align:start position:0% +model the further you excursions from + + + align:start position:0% +model the further you excursions from +the real trajectory + + align:start position:0% +the real trajectory + + + align:start position:0% +the real trajectory +the bigger the error you get so if you + + align:start position:0% +the bigger the error you get so if you + + + align:start position:0% +the bigger the error you get so if you +do the balance method you can see what + + align:start position:0% +do the balance method you can see what + + + align:start position:0% +do the balance method you can see what +happens is that when you get to + + align:start position:0% +happens is that when you get to + + + align:start position:0% +happens is that when you get to +steady-state all the steps are just + + align:start position:0% +steady-state all the steps are just + + + align:start position:0% +steady-state all the steps are just +moving you along the state a trajectory + + align:start position:0% +moving you along the state a trajectory + + + align:start position:0% +moving you along the state a trajectory +they're basically maintaining the steady + + align:start position:0% +they're basically maintaining the steady + + + align:start position:0% +they're basically maintaining the steady +state and that's because I added you + + align:start position:0% +state and that's because I added you + + + align:start position:0% +state and that's because I added you +know it's like transport plus half of + + align:start position:0% +know it's like transport plus half of + + + align:start position:0% +know it's like transport plus half of +transport plus ours and oh there's a + + align:start position:0% +transport plus ours and oh there's a + + + align:start position:0% +transport plus ours and oh there's a +present minus sign here so like that so + + align:start position:0% +present minus sign here so like that so + + + align:start position:0% +present minus sign here so like that so +I'm getting rid of half of my transport + + align:start position:0% +I'm getting rid of half of my transport + + + align:start position:0% +I'm getting rid of half of my transport +and I'm adding in half of this so I've + + align:start position:0% +and I'm adding in half of this so I've + + + align:start position:0% +and I'm adding in half of this so I've +changed before I had dy DT is equal to T + + align:start position:0% +changed before I had dy DT is equal to T + + + align:start position:0% +changed before I had dy DT is equal to T +and now I have dy DT is equal to 1/2 of + + align:start position:0% +and now I have dy DT is equal to 1/2 of + + + align:start position:0% +and now I have dy DT is equal to 1/2 of +T mistake so half of T mine minus F of R + + align:start position:0% + + + + align:start position:0% + +and it's can't be right it must say this + + align:start position:0% +and it's can't be right it must say this + + + align:start position:0% +and it's can't be right it must say this +I must have a sign maybe this is not + + align:start position:0% +I must have a sign maybe this is not + + + align:start position:0% +I must have a sign maybe this is not +it's not the average it should be - it's + + align:start position:0% +it's not the average it should be - it's + + + align:start position:0% +it's not the average it should be - it's +like that the these hoops should be + + align:start position:0% +like that the these hoops should be + + + align:start position:0% +like that the these hoops should be +added and this is because you're + + align:start position:0% +added and this is because you're + + + align:start position:0% +added and this is because you're +canceled out so basically the only teach + + align:start position:0% +canceled out so basically the only teach + + + align:start position:0% +canceled out so basically the only teach +give me zero which is which should be at + + align:start position:0% +give me zero which is which should be at + + + align:start position:0% +give me zero which is which should be at +a steady state so I'm sorry this is that + + align:start position:0% +a steady state so I'm sorry this is that + + + align:start position:0% +a steady state so I'm sorry this is that +previous slide at the sign room this is + + align:start position:0% +previous slide at the sign room this is + + + align:start position:0% +previous slide at the sign room this is +what happens as the solution if you do + + align:start position:0% +what happens as the solution if you do + + + align:start position:0% +what happens as the solution if you do +Strank splitting on the left you get + + align:start position:0% +Strank splitting on the left you get + + + align:start position:0% +Strank splitting on the left you get +more accuracy as you increase as you cut + + align:start position:0% +more accuracy as you increase as you cut + + + align:start position:0% +more accuracy as you increase as you cut +TT but it's only it's not getting any + + align:start position:0% +TT but it's only it's not getting any + + + align:start position:0% +TT but it's only it's not getting any +better + + align:start position:0% +better + + + align:start position:0% +better +it doesn't matter if it's near steady + + align:start position:0% +it doesn't matter if it's near steady + + + align:start position:0% +it doesn't matter if it's near steady +state or away from steady state it it + + align:start position:0% +state or away from steady state it it + + + align:start position:0% +state or away from steady state it it +treats everything equally strange + + align:start position:0% +treats everything equally strange + + + align:start position:0% +treats everything equally strange +putting in the balance splittings as you + + align:start position:0% +putting in the balance splittings as you + + + align:start position:0% +putting in the balance splittings as you +get to steady state all sudden the urge + + align:start position:0% +get to steady state all sudden the urge + + + align:start position:0% +get to steady state all sudden the urge +drive exponentially you see the + + align:start position:0% +drive exponentially you see the + + + align:start position:0% +drive exponentially you see the +logarithm of the air library tape lot so + + align:start position:0% +logarithm of the air library tape lot so + + + align:start position:0% +logarithm of the air library tape lot so +you get tremendously great convergence + + align:start position:0% +you get tremendously great convergence + + + align:start position:0% +you get tremendously great convergence +to the real steady state once you get + + align:start position:0% +to the real steady state once you get + + + align:start position:0% +to the real steady state once you get +anywhere close to this a state now the + + align:start position:0% +anywhere close to this a state now the + + + align:start position:0% +anywhere close to this a state now the +the cost of this is it because the + + align:start position:0% +the cost of this is it because the + + + align:start position:0% +the cost of this is it because the +formula was just which I has a sign + + align:start position:0% +formula was just which I has a sign + + + align:start position:0% +formula was just which I has a sign +mistake I think it depends on yn it + + align:start position:0% +mistake I think it depends on yn it + + + align:start position:0% +mistake I think it depends on yn it +makes the whole thing numerically more + + align:start position:0% +makes the whole thing numerically more + + + align:start position:0% +makes the whole thing numerically more +unstable because it's like an explicit + + align:start position:0% +unstable because it's like an explicit + + + align:start position:0% +unstable because it's like an explicit +thing we're using what happened in + + align:start position:0% +thing we're using what happened in + + + align:start position:0% +thing we're using what happened in +previous time to correct our equation + + align:start position:0% +previous time to correct our equation + + + align:start position:0% +previous time to correct our equation +for future times and so you get are more + + align:start position:0% +for future times and so you get are more + + + align:start position:0% +for future times and so you get are more +likely to numerical instabilities so + + align:start position:0% +likely to numerical instabilities so + + + align:start position:0% +likely to numerical instabilities so +then reinvented an implicit version of + + align:start position:0% +then reinvented an implicit version of + + + align:start position:0% +then reinvented an implicit version of +that and also a higher order method and + + align:start position:0% +that and also a higher order method and + + + align:start position:0% +that and also a higher order method and +that's called rebalance splitting the + + align:start position:0% +that's called rebalance splitting the + + + align:start position:0% +that's called rebalance splitting the +equation is way too complicated me to + + align:start position:0% +equation is way too complicated me to + + + align:start position:0% +equation is way too complicated me to +write down since I can't even write down + + align:start position:0% +write down since I can't even write down + + + align:start position:0% +write down since I can't even write down +that something minus signs correctly in + + align:start position:0% +that something minus signs correctly in + + + align:start position:0% +that something minus signs correctly in +this one but you're happy to read the + + align:start position:0% +this one but you're happy to read the + + + align:start position:0% +this one but you're happy to read the +paper it's in Siam and he has the + + align:start position:0% +paper it's in Siam and he has the + + + align:start position:0% +paper it's in Siam and he has the +equations for that and we put the second + + align:start position:0% +equations for that and we put the second + + + align:start position:0% +equations for that and we put the second +order one end that's implicit then the + + align:start position:0% +order one end that's implicit then the + + + align:start position:0% +order one end that's implicit then the +thing is just as stable as strike + + align:start position:0% +thing is just as stable as strike + + + align:start position:0% +thing is just as stable as strike +splitting but it also has this great + + align:start position:0% +splitting but it also has this great + + + align:start position:0% +splitting but it also has this great +property that as you cook it close to + + align:start position:0% +property that as you cook it close to + + + align:start position:0% +property that as you cook it close to +tie to state it exponentially converges + + align:start position:0% +tie to state it exponentially converges + + + align:start position:0% +tie to state it exponentially converges +to the solution which is sir like how + + align:start position:0% +to the solution which is sir like how + + + align:start position:0% +to the solution which is sir like how +Newton's method is really so good it's + + align:start position:0% +Newton's method is really so good it's + + + align:start position:0% +Newton's method is really so good it's +sort of like that doesn't you get you + + align:start position:0% +sort of like that doesn't you get you + + + align:start position:0% +sort of like that doesn't you get you +get a lot more decimal places really + + align:start position:0% +get a lot more decimal places really + + + align:start position:0% +get a lot more decimal places really +fast why'd you get close to steady-state + + align:start position:0% +fast why'd you get close to steady-state + + + align:start position:0% +fast why'd you get close to steady-state +all right that's enough enjoy + + align:start position:0% +all right that's enough enjoy + + + align:start position:0% +all right that's enough enjoy +Thanksgiving I posted a bunch of + + align:start position:0% +Thanksgiving I posted a bunch of + + + align:start position:0% +Thanksgiving I posted a bunch of +readings and things about my trop + + align:start position:0% +readings and things about my trop + + + align:start position:0% +readings and things about my trop +Monte Carlo and stochastic stuff we're + + align:start position:0% +Monte Carlo and stochastic stuff we're + + + align:start position:0% +Monte Carlo and stochastic stuff we're +gonna talk about next week and also a + + align:start position:0% +gonna talk about next week and also a + + + align:start position:0% +gonna talk about next week and also a +little bit more about moles versus data + + align:start position:0% +little bit more about moles versus data + + + align:start position:0% +little bit more about moles versus data +so do the reading when you get a chance + + align:start position:0% +so do the reading when you get a chance + + + align:start position:0% +so do the reading when you get a chance +say how your families see how your + + align:start position:0% +say how your families see how your + + + align:start position:0% +say how your families see how your +friends nice time \ No newline at end of file diff --git a/4ip-4ai6kN8.txt b/4ip-4ai6kN8.txt new file mode 100644 index 0000000000000000000000000000000000000000..12fcf7dc78d6385c1f0074e15d2f2c69789d2f4b --- /dev/null +++ b/4ip-4ai6kN8.txt @@ -0,0 +1,11467 @@ +align:start position:0% + +so who were + + align:start position:0% +so who were + + + align:start position:0% +so who were +that's called a spectrogram good and + + align:start position:0% +that's called a spectrogram good and + + + align:start position:0% +that's called a spectrogram good and +it's a spectrogram of me good morning + + align:start position:0% +it's a spectrogram of me good morning + + + align:start position:0% +it's a spectrogram of me good morning +class + + align:start position:0% +class + + + align:start position:0% +class +okay so it's a spectrum of speech okay + + align:start position:0% +okay so it's a spectrum of speech okay + + + align:start position:0% +okay so it's a spectrum of speech okay +and so we are going to continue today on + + align:start position:0% +and so we are going to continue today on + + + align:start position:0% +and so we are going to continue today on +the topic of understanding developing + + align:start position:0% +the topic of understanding developing + + + align:start position:0% +the topic of understanding developing +methods for understanding how to + + align:start position:0% +methods for understanding how to + + + align:start position:0% +methods for understanding how to +characterize and and understand + + align:start position:0% +characterize and and understand + + + align:start position:0% +characterize and and understand +temporally structured signals so that is + + align:start position:0% +temporally structured signals so that is + + + align:start position:0% +temporally structured signals so that is +the microphone recording of my voice + + align:start position:0% +the microphone recording of my voice + + + align:start position:0% +the microphone recording of my voice +saying a good good morning class and + + align:start position:0% +saying a good good morning class and + + + align:start position:0% +saying a good good morning class and +then this is a spectrogram of that + + align:start position:0% +then this is a spectrogram of that + + + align:start position:0% +then this is a spectrogram of that +signal where at each moment in time you + + align:start position:0% +signal where at each moment in time you + + + align:start position:0% +signal where at each moment in time you +can actually extract the spectral + + align:start position:0% +can actually extract the spectral + + + align:start position:0% +can actually extract the spectral +structure of that signal and you can see + + align:start position:0% +structure of that signal and you can see + + + align:start position:0% +structure of that signal and you can see +that the information in speech signals + + align:start position:0% +that the information in speech signals + + + align:start position:0% +that the information in speech signals +is actually carried in in parts of the + + align:start position:0% +is actually carried in in parts of the + + + align:start position:0% +is actually carried in in parts of the +signal in the way the power and the + + align:start position:0% +signal in the way the power and the + + + align:start position:0% +signal in the way the power and the +signal at different frequencies changes + + align:start position:0% +signal at different frequencies changes + + + align:start position:0% +signal at different frequencies changes +over time okay your ears detect these + + align:start position:0% +over time okay your ears detect these + + + align:start position:0% +over time okay your ears detect these +changes in frequency and translate that + + align:start position:0% +changes in frequency and translate that + + + align:start position:0% +changes in frequency and translate that +into information about what I'm saying + + align:start position:0% +into information about what I'm saying + + + align:start position:0% +into information about what I'm saying +okay and so we're going to today start + + align:start position:0% +okay and so we're going to today start + + + align:start position:0% +okay and so we're going to today start +on a well we sort of started last time + + align:start position:0% +on a well we sort of started last time + + + align:start position:0% +on a well we sort of started last time +but we're really going to get going on + + align:start position:0% +but we're really going to get going on + + + align:start position:0% +but we're really going to get going on +this in the next three lectures we're + + align:start position:0% +this in the next three lectures we're + + + align:start position:0% +this in the next three lectures we're +gonna develop a powerful set of tools + + align:start position:0% +gonna develop a powerful set of tools + + + align:start position:0% +gonna develop a powerful set of tools +for characterizing and understanding the + + align:start position:0% +for characterizing and understanding the + + + align:start position:0% +for characterizing and understanding the +temporal structure of signals okay so + + align:start position:0% +temporal structure of signals okay so + + + align:start position:0% +temporal structure of signals okay so +this is the the gameplan for the next + + align:start position:0% +this is the the gameplan for the next + + + align:start position:0% +this is the the gameplan for the next +three lectures today we're going to + + align:start position:0% +three lectures today we're going to + + + align:start position:0% +three lectures today we're going to +cover a Fourier series complex Fourier + + align:start position:0% +cover a Fourier series complex Fourier + + + align:start position:0% +cover a Fourier series complex Fourier +series we're going to extend that to the + + align:start position:0% +series we're going to extend that to the + + + align:start position:0% +series we're going to extend that to the +idea of the Fourier transform and then + + align:start position:0% +idea of the Fourier transform and then + + + align:start position:0% +idea of the Fourier transform and then +so the Fourier transform is sort of a + + align:start position:0% +so the Fourier transform is sort of a + + + align:start position:0% +so the Fourier transform is sort of a +very general mathematical approach to + + align:start position:0% +very general mathematical approach to + + + align:start position:0% +very general mathematical approach to +understanding that the temporal + + align:start position:0% +understanding that the temporal + + + align:start position:0% +understanding that the temporal +structure of signals that's that's more + + align:start position:0% +structure of signals that's that's more + + + align:start position:0% +structure of signals that's that's more +of a you think of that more in the terms + + align:start position:0% +of a you think of that more in the terms + + + align:start position:0% +of a you think of that more in the terms +of doing in terms of doing analytical + + align:start position:0% +of doing in terms of doing analytical + + + align:start position:0% +of doing in terms of doing analytical +calculations or or or sort of conceptual + + align:start position:0% +calculations or or or sort of conceptual + + + align:start position:0% +calculations or or or sort of conceptual +understanding of what + + align:start position:0% +understanding of what + + + align:start position:0% +understanding of what +Fourier decomposition is but then + + align:start position:0% +Fourier decomposition is but then + + + align:start position:0% +Fourier decomposition is but then +there's a very concrete algorithm for + + align:start position:0% +there's a very concrete algorithm for + + + align:start position:0% +there's a very concrete algorithm for +for characterizing spectral structure of + + align:start position:0% +for characterizing spectral structure of + + + align:start position:0% +for characterizing spectral structure of +signals called the fast Fourier + + align:start position:0% +signals called the fast Fourier + + + align:start position:0% +signals called the fast Fourier +transform and that's one class of + + align:start position:0% +transform and that's one class of + + + align:start position:0% +transform and that's one class of +methods where you sample signals + + align:start position:0% +methods where you sample signals + + + align:start position:0% +methods where you sample signals +discretely in time and get back discrete + + align:start position:0% +discretely in time and get back discrete + + + align:start position:0% +discretely in time and get back discrete +power at discrete frequencies so that's + + align:start position:0% +power at discrete frequencies so that's + + + align:start position:0% +power at discrete frequencies so that's +called a discrete Fourier transform and + + align:start position:0% +called a discrete Fourier transform and + + + align:start position:0% +called a discrete Fourier transform and +most often that's used to compute the + + align:start position:0% +most often that's used to compute the + + + align:start position:0% +most often that's used to compute the +power spectrum of signals and so that's + + align:start position:0% +power spectrum of signals and so that's + + + align:start position:0% +power spectrum of signals and so that's +what we're gonna cover today and then in + + align:start position:0% +what we're gonna cover today and then in + + + align:start position:0% +what we're gonna cover today and then in +the next lecture we're gonna cover a + + align:start position:0% +the next lecture we're gonna cover a + + + align:start position:0% +the next lecture we're gonna cover a +number of topics leading up to spectral + + align:start position:0% +number of topics leading up to spectral + + + align:start position:0% +number of topics leading up to spectral +estimation we're gonna start with the + + align:start position:0% +estimation we're gonna start with the + + + align:start position:0% +estimation we're gonna start with the +convolution theorem which is a really + + align:start position:0% +convolution theorem which is a really + + + align:start position:0% +convolution theorem which is a really +powerful way of understanding the + + align:start position:0% +powerful way of understanding the + + + align:start position:0% +powerful way of understanding the +relationship between convolution in the + + align:start position:0% +relationship between convolution in the + + + align:start position:0% +relationship between convolution in the +time domain and multiplication of things + + align:start position:0% +time domain and multiplication of things + + + align:start position:0% +time domain and multiplication of things +in the frequency domain and and the + + align:start position:0% +in the frequency domain and and the + + + align:start position:0% +in the frequency domain and and the +convolution theorem is really powerful + + align:start position:0% +convolution theorem is really powerful + + + align:start position:0% +convolution theorem is really powerful +allowing you to kind of think about and + + align:start position:0% +allowing you to kind of think about and + + + align:start position:0% +allowing you to kind of think about and +to ative lee understand the spectral + + align:start position:0% +to ative lee understand the spectral + + + align:start position:0% +to ative lee understand the spectral +structure of different kinds of signals + + align:start position:0% +structure of different kinds of signals + + + align:start position:0% +structure of different kinds of signals +that you can build by convolving + + align:start position:0% +that you can build by convolving + + + align:start position:0% +that you can build by convolving +different sort of basic elements so if + + align:start position:0% +different sort of basic elements so if + + + align:start position:0% +different sort of basic elements so if +you understand the Fourier decomposition + + align:start position:0% +you understand the Fourier decomposition + + + align:start position:0% +you understand the Fourier decomposition +of a square pulse and a train of pulses + + align:start position:0% +of a square pulse and a train of pulses + + + align:start position:0% +of a square pulse and a train of pulses +or a Gaussian you can basically just by + + align:start position:0% +or a Gaussian you can basically just by + + + align:start position:0% +or a Gaussian you can basically just by +kind of thinking about it figure out the + + align:start position:0% +kind of thinking about it figure out the + + + align:start position:0% +kind of thinking about it figure out the +spectral structure of a lot of different + + align:start position:0% +spectral structure of a lot of different + + + align:start position:0% +spectral structure of a lot of different +signals by just combining those things + + align:start position:0% +signals by just combining those things + + + align:start position:0% +signals by just combining those things +sort of like Lego blocks it's super cool + + align:start position:0% +sort of like Lego blocks it's super cool + + + align:start position:0% +sort of like Lego blocks it's super cool +we're gonna talk about noise and + + align:start position:0% +we're gonna talk about noise and + + + align:start position:0% +we're gonna talk about noise and +filtering we're going to talk about the + + align:start position:0% +filtering we're going to talk about the + + + align:start position:0% +filtering we're going to talk about the +Shannon Nyquist sampling theorem which + + align:start position:0% +Shannon Nyquist sampling theorem which + + + align:start position:0% +Shannon Nyquist sampling theorem which +tells you how fast you have to sample a + + align:start position:0% +tells you how fast you have to sample a + + + align:start position:0% +tells you how fast you have to sample a +signal in order to perfectly reconstruct + + align:start position:0% +signal in order to perfectly reconstruct + + + align:start position:0% +signal in order to perfectly reconstruct +it it turns out it's really amazing if + + align:start position:0% +it it turns out it's really amazing if + + + align:start position:0% +it it turns out it's really amazing if +you have a signal in time you can sample + + align:start position:0% +you have a signal in time you can sample + + + align:start position:0% +you have a signal in time you can sample +that signal at regular intervals and + + align:start position:0% +that signal at regular intervals and + + + align:start position:0% +that signal at regular intervals and +perfectly reconstruct the signal if that + + align:start position:0% +perfectly reconstruct the signal if that + + + align:start position:0% +perfectly reconstruct the signal if that +signal doesn't have frequency components + + align:start position:0% +signal doesn't have frequency components + + + align:start position:0% +signal doesn't have frequency components +that are too high and so that's captured + + align:start position:0% +that are too high and so that's captured + + + align:start position:0% +that are too high and so that's captured +in this Shannon Nyquist sampling theorem + + align:start position:0% +in this Shannon Nyquist sampling theorem + + + align:start position:0% +in this Shannon Nyquist sampling theorem +that turns out to actually be a topic of + + align:start position:0% +that turns out to actually be a topic of + + + align:start position:0% +that turns out to actually be a topic of +current debate there's a there was a + + align:start position:0% +current debate there's a there was a + + + align:start position:0% +current debate there's a there was a +paper published recently by somebody + + align:start position:0% +paper published recently by somebody + + + align:start position:0% +paper published recently by somebody +claiming to be able to get around the + + align:start position:0% +claiming to be able to get around the + + + align:start position:0% +claiming to be able to get around the +sampling theorem and record neural + + align:start position:0% +sampling theorem and record neural + + + align:start position:0% +sampling theorem and record neural +signals without having to + + align:start position:0% +signals without having to + + + align:start position:0% +signals without having to +guarantee they're the conditions under + + align:start position:0% +guarantee they're the conditions under + + + align:start position:0% +guarantee they're the conditions under +which that Nyquist's Shannon Nyquist + + align:start position:0% +which that Nyquist's Shannon Nyquist + + + align:start position:0% +which that Nyquist's Shannon Nyquist +sampling theorem claims and Marcus + + align:start position:0% +sampling theorem claims and Marcus + + + align:start position:0% +sampling theorem claims and Marcus +Meister wrote a scathing rebuttal to + + align:start position:0% +Meister wrote a scathing rebuttal to + + + align:start position:0% +Meister wrote a scathing rebuttal to +that basically claiming that they're + + align:start position:0% +that basically claiming that they're + + + align:start position:0% +that basically claiming that they're +full of baloney and so you know that + + align:start position:0% +full of baloney and so you know that + + + align:start position:0% +full of baloney and so you know that +those folks who wrote that paper maybe + + align:start position:0% +those folks who wrote that paper maybe + + + align:start position:0% +those folks who wrote that paper maybe +should have taken in this class so + + align:start position:0% +should have taken in this class so + + + align:start position:0% +should have taken in this class so +anyway you don't want to be on the wrong + + align:start position:0% +anyway you don't want to be on the wrong + + + align:start position:0% +anyway you don't want to be on the wrong +end of Marcus Meister's blog post so so + + align:start position:0% +end of Marcus Meister's blog post so so + + + align:start position:0% +end of Marcus Meister's blog post so so +pay attention ok so then we're gonna get + + align:start position:0% +pay attention ok so then we're gonna get + + + align:start position:0% +pay attention ok so then we're gonna get +into spectral estimation then in the + + align:start position:0% +into spectral estimation then in the + + + align:start position:0% +into spectral estimation then in the +last lecture we're going to talk about + + align:start position:0% +last lecture we're going to talk about + + + align:start position:0% +last lecture we're going to talk about +spectrograms we're gonna talk about how + + align:start position:0% +spectrograms we're gonna talk about how + + + align:start position:0% +spectrograms we're gonna talk about how +to compute spectrograms and understand + + align:start position:0% +to compute spectrograms and understand + + + align:start position:0% +to compute spectrograms and understand +really how to take the data and break it + + align:start position:0% +really how to take the data and break it + + + align:start position:0% +really how to take the data and break it +into samples called windowing how to + + align:start position:0% +into samples called windowing how to + + + align:start position:0% +into samples called windowing how to +multiply those samples by what's called + + align:start position:0% +multiply those samples by what's called + + + align:start position:0% +multiply those samples by what's called +a taper to avoid contaminating the + + align:start position:0% +a taper to avoid contaminating the + + + align:start position:0% +a taper to avoid contaminating the +signal with lots of noise that's + + align:start position:0% +signal with lots of noise that's + + + align:start position:0% +signal with lots of noise that's +unnecessary we're gonna understand the + + align:start position:0% +unnecessary we're gonna understand the + + + align:start position:0% +unnecessary we're gonna understand the +idea of time bandwidth product how do + + align:start position:0% +idea of time bandwidth product how do + + + align:start position:0% +idea of time bandwidth product how do +you choose the width of that window to + + align:start position:0% +you choose the width of that window to + + + align:start position:0% +you choose the width of that window to +emphasize different parts of the data + + align:start position:0% +emphasize different parts of the data + + + align:start position:0% +emphasize different parts of the data +and then we're going to end with some + + align:start position:0% +and then we're going to end with some + + + align:start position:0% +and then we're going to end with some +advanced filtering methods that are + + align:start position:0% +advanced filtering methods that are + + + align:start position:0% +advanced filtering methods that are +commonly used to to control different + + align:start position:0% +commonly used to to control different + + + align:start position:0% +commonly used to to control different +frequency components of signals in your + + align:start position:0% +frequency components of signals in your + + + align:start position:0% +frequency components of signals in your +data ok so a bunch of really powerful + + align:start position:0% +data ok so a bunch of really powerful + + + align:start position:0% +data ok so a bunch of really powerful +things here's what we're going to talk + + align:start position:0% +things here's what we're going to talk + + + align:start position:0% +things here's what we're going to talk +about today we're gonna start we're + + align:start position:0% +about today we're gonna start we're + + + align:start position:0% +about today we're gonna start we're +gonna continue with this Fourier series + + align:start position:0% +gonna continue with this Fourier series + + + align:start position:0% +gonna continue with this Fourier series +we started with symmetric functions last + + align:start position:0% +we started with symmetric functions last + + + align:start position:0% +we started with symmetric functions last +time we're going to finish that and then + + align:start position:0% +time we're going to finish that and then + + + align:start position:0% +time we're going to finish that and then +talk about asymmetric functions + + align:start position:0% +talk about asymmetric functions + + + align:start position:0% +talk about asymmetric functions +we're gonna extend that to complex + + align:start position:0% +we're gonna extend that to complex + + + align:start position:0% +we're gonna extend that to complex +Fourier series introduce the Fourier + + align:start position:0% +Fourier series introduce the Fourier + + + align:start position:0% +Fourier series introduce the Fourier +transform the discrete Fourier transform + + align:start position:0% +transform the discrete Fourier transform + + + align:start position:0% +transform the discrete Fourier transform +and this algorithm the fast Fourier + + align:start position:0% +and this algorithm the fast Fourier + + + align:start position:0% +and this algorithm the fast Fourier +transform and then I'm going to show you + + align:start position:0% +transform and then I'm going to show you + + + align:start position:0% +transform and then I'm going to show you +how to compute power spectrum so just to + + align:start position:0% +how to compute power spectrum so just to + + + align:start position:0% +how to compute power spectrum so just to +make it clear all of this stuff is + + align:start position:0% +make it clear all of this stuff is + + + align:start position:0% +make it clear all of this stuff is +basically going to be to teach you how + + align:start position:0% +basically going to be to teach you how + + + align:start position:0% +basically going to be to teach you how +to use one line of matlab ok one + + align:start position:0% +to use one line of matlab ok one + + + align:start position:0% +to use one line of matlab ok one +function FFT ok now the problem is it's + + align:start position:0% +function FFT ok now the problem is it's + + + align:start position:0% +function FFT ok now the problem is it's +really easy to do this wrong ok + + align:start position:0% +really easy to do this wrong ok + + + align:start position:0% +really easy to do this wrong ok +it's really easy to use this but not + + align:start position:0% +it's really easy to use this but not + + + align:start position:0% +it's really easy to use this but not +understand what you're doing and come up + + align:start position:0% +understand what you're doing and come up + + + align:start position:0% +understand what you're doing and come up +with the wrong answer ok so so all of + + align:start position:0% +with the wrong answer ok so so all of + + + align:start position:0% +with the wrong answer ok so so all of +these things that we're going to talk + + align:start position:0% +these things that we're going to talk + + + align:start position:0% +these things that we're going to talk +about today are just the kind of basics + + align:start position:0% +about today are just the kind of basics + + + align:start position:0% +about today are just the kind of basics +that you need to understand in order to + + align:start position:0% +that you need to understand in order to + + + align:start position:0% +that you need to understand in order to +use the + + align:start position:0% +use the + + + align:start position:0% +use the +very powerful function in MATLAB okay + + align:start position:0% +very powerful function in MATLAB okay + + + align:start position:0% +very powerful function in MATLAB okay +all right okay so let's get started so + + align:start position:0% +all right okay so let's get started so + + + align:start position:0% +all right okay so let's get started so +last time we we introduced the idea of a + + align:start position:0% +last time we we introduced the idea of a + + + align:start position:0% +last time we we introduced the idea of a +Fourier series we talked about the idea + + align:start position:0% +Fourier series we talked about the idea + + + align:start position:0% +Fourier series we talked about the idea +that you can approximate any periodic + + align:start position:0% +that you can approximate any periodic + + + align:start position:0% +that you can approximate any periodic +function so here I'm just taking a + + align:start position:0% +function so here I'm just taking a + + + align:start position:0% +function so here I'm just taking a +square wave that alternates between + + align:start position:0% +square wave that alternates between + + + align:start position:0% +square wave that alternates between +positive and negative it's periodic with + + align:start position:0% +positive and negative it's periodic with + + + align:start position:0% +positive and negative it's periodic with +a period capital T so it's a function of + + align:start position:0% +a period capital T so it's a function of + + + align:start position:0% +a period capital T so it's a function of +time it's a it's a even function or a + + align:start position:0% +time it's a it's a even function or a + + + align:start position:0% +time it's a it's a even function or a +symmetric function because you can see + + align:start position:0% +symmetric function because you can see + + + align:start position:0% +symmetric function because you can see +that it's it's basically mirror symmetry + + align:start position:0% +that it's it's basically mirror symmetry + + + align:start position:0% +that it's it's basically mirror symmetry +around the y axis okay it's even because + + align:start position:0% +around the y axis okay it's even because + + + align:start position:0% +around the y axis okay it's even because +even polynomials also have that property + + align:start position:0% +even polynomials also have that property + + + align:start position:0% +even polynomials also have that property +of being symmetric we can approximate + + align:start position:0% +of being symmetric we can approximate + + + align:start position:0% +of being symmetric we can approximate +this this periodic function T as a sum + + align:start position:0% +this this periodic function T as a sum + + + align:start position:0% +this this periodic function T as a sum +of sine waves or cosine waves in this + + align:start position:0% +of sine waves or cosine waves in this + + + align:start position:0% +of sine waves or cosine waves in this +case we can approximate that as a cosine + + align:start position:0% +case we can approximate that as a cosine + + + align:start position:0% +case we can approximate that as a cosine +wave of the same period and the same + + align:start position:0% +wave of the same period and the same + + + align:start position:0% +wave of the same period and the same +amplitude so we can approximate it as as + + align:start position:0% +amplitude so we can approximate it as as + + + align:start position:0% +amplitude so we can approximate it as as +a coefficient times cosine 2 pi F naught + + align:start position:0% +a coefficient times cosine 2 pi F naught + + + align:start position:0% +a coefficient times cosine 2 pi F naught +T where F naught is just 1 over the + + align:start position:0% +T where F naught is just 1 over the + + + align:start position:0% +T where F naught is just 1 over the +period alright so if the period is 1 + + align:start position:0% +period alright so if the period is 1 + + + align:start position:0% +period alright so if the period is 1 +second then the frequency is 1 Hertz 1 + + align:start position:0% +second then the frequency is 1 Hertz 1 + + + align:start position:0% +second then the frequency is 1 Hertz 1 +over 1 second we often use this + + align:start position:0% +over 1 second we often use this + + + align:start position:0% +over 1 second we often use this +different representation of frequency + + align:start position:0% +different representation of frequency + + + align:start position:0% +different representation of frequency +which is usually called Omega which is + + align:start position:0% +which is usually called Omega which is + + + align:start position:0% +which is usually called Omega which is +angular frequency and it's just 2 pi + + align:start position:0% +angular frequency and it's just 2 pi + + + align:start position:0% +angular frequency and it's just 2 pi +times this oscillation frequency and it + + align:start position:0% +times this oscillation frequency and it + + + align:start position:0% +times this oscillation frequency and it +has units of radians per second alright + + align:start position:0% +has units of radians per second alright + + + align:start position:0% +has units of radians per second alright +so we talked about the fact that you can + + align:start position:0% +so we talked about the fact that you can + + + align:start position:0% +so we talked about the fact that you can +approximate this periodic function as a + + align:start position:0% +approximate this periodic function as a + + + align:start position:0% +approximate this periodic function as a +sum of cosines we talked about the idea + + align:start position:0% +sum of cosines we talked about the idea + + + align:start position:0% +sum of cosines we talked about the idea +that you only need to consider cosines + + align:start position:0% +that you only need to consider cosines + + + align:start position:0% +that you only need to consider cosines +that are integer multiples of Omega not + + align:start position:0% +that are integer multiples of Omega not + + + align:start position:0% +that are integer multiples of Omega not +because those are the only cosine + + align:start position:0% +because those are the only cosine + + + align:start position:0% +because those are the only cosine +functions those are the only functions + + align:start position:0% +functions those are the only functions + + + align:start position:0% +functions those are the only functions +that also are periodic at frequency + + align:start position:0% +that also are periodic at frequency + + + align:start position:0% +that also are periodic at frequency +Omega naught right so a function cosine + + align:start position:0% +Omega naught right so a function cosine + + + align:start position:0% +Omega naught right so a function cosine +3 Omega naught T is also periodic at + + align:start position:0% +3 Omega naught T is also periodic at + + + align:start position:0% +3 Omega naught T is also periodic at +frequency Omega naught does that make + + align:start position:0% +frequency Omega naught does that make + + + align:start position:0% +frequency Omega naught does that make +sense ok so now we can approximate any + + align:start position:0% +sense ok so now we can approximate any + + + align:start position:0% +sense ok so now we can approximate any +periodic function in this case any even + + align:start position:0% +periodic function in this case any even + + + align:start position:0% +periodic function in this case any even +or symmetric periodic function + + align:start position:0% +or symmetric periodic function + + + align:start position:0% +or symmetric periodic function +as a sum of cosines of frequency the + + align:start position:0% +as a sum of cosines of frequency the + + + align:start position:0% +as a sum of cosines of frequency the +frequencies that are integer multiples + + align:start position:0% +frequencies that are integer multiples + + + align:start position:0% +frequencies that are integer multiples +of Omega not and each one of those + + align:start position:0% +of Omega not and each one of those + + + align:start position:0% +of Omega not and each one of those +cosines will have a different + + align:start position:0% +cosines will have a different + + + align:start position:0% +cosines will have a different +coefficient so here's an example where + + align:start position:0% +coefficient so here's an example where + + + align:start position:0% +coefficient so here's an example where +I'm approximating this square wave here + + align:start position:0% +I'm approximating this square wave here + + + align:start position:0% +I'm approximating this square wave here +as a sum of cosines of these different + + align:start position:0% +as a sum of cosines of these different + + + align:start position:0% +as a sum of cosines of these different +frequencies and it turns out for a + + align:start position:0% +frequencies and it turns out for a + + + align:start position:0% +frequencies and it turns out for a +square wave you only need the odd + + align:start position:0% +square wave you only need the odd + + + align:start position:0% +square wave you only need the odd +multiples of Omega not so here's what + + align:start position:0% +multiples of Omega not so here's what + + + align:start position:0% +multiples of Omega not so here's what +this approximation looks like for the + + align:start position:0% +this approximation looks like for the + + + align:start position:0% +this approximation looks like for the +case where you only have a single cosine + + align:start position:0% +case where you only have a single cosine + + + align:start position:0% +case where you only have a single cosine +function you can add another cosine of + + align:start position:0% +function you can add another cosine of + + + align:start position:0% +function you can add another cosine of +three Omega naught T and you can see + + align:start position:0% +three Omega naught T and you can see + + + align:start position:0% +three Omega naught T and you can see +that that function starts getting a + + align:start position:0% +that that function starts getting a + + + align:start position:0% +that that function starts getting a +little bit more square you can add a + + align:start position:0% +little bit more square you can add a + + + align:start position:0% +little bit more square you can add a +cosine 5 Omega naught T and as you keep + + align:start position:0% +cosine 5 Omega naught T and as you keep + + + align:start position:0% +cosine 5 Omega naught T and as you keep +adding those things again with the + + align:start position:0% +adding those things again with the + + + align:start position:0% +adding those things again with the +correct coefficients in front of these + + align:start position:0% +correct coefficients in front of these + + + align:start position:0% +correct coefficients in front of these +you can see that the function more and + + align:start position:0% +you can see that the function more and + + + align:start position:0% +you can see that the function more and +more closely approximates the square + + align:start position:0% +more closely approximates the square + + + align:start position:0% +more closely approximates the square +wave that we're trying to yes happy but + + align:start position:0% +wave that we're trying to yes happy but + + + align:start position:0% +wave that we're trying to yes happy but +it just it's in general you need all the + + align:start position:0% +it just it's in general you need all the + + + align:start position:0% +it just it's in general you need all the +multiples but for this particular + + align:start position:0% +multiples but for this particular + + + align:start position:0% +multiples but for this particular +function you only need the odd ones okay + + align:start position:0% + + + + align:start position:0% + +okay here's another example so in this + + align:start position:0% +okay here's another example so in this + + + align:start position:0% +okay here's another example so in this +case work we are summing together cosine + + align:start position:0% +case work we are summing together cosine + + + align:start position:0% +case work we are summing together cosine +functions to approximate a train of + + align:start position:0% +functions to approximate a train of + + + align:start position:0% +functions to approximate a train of +pulses okay so the signal we're trying + + align:start position:0% +pulses okay so the signal we're trying + + + align:start position:0% +pulses okay so the signal we're trying +to approximate here it just has a pulse + + align:start position:0% +to approximate here it just has a pulse + + + align:start position:0% +to approximate here it just has a pulse +every one unit of time one one period + + align:start position:0% +every one unit of time one one period + + + align:start position:0% +every one unit of time one one period +and you can see that to approximate this + + align:start position:0% +and you can see that to approximate this + + + align:start position:0% +and you can see that to approximate this +we can basically just sum up all the + + align:start position:0% +we can basically just sum up all the + + + align:start position:0% +we can basically just sum up all the +cosines of all frequencies n Omega + + align:start position:0% +cosines of all frequencies n Omega + + + align:start position:0% +cosines of all frequencies n Omega +naught and you can see that at time zero + + align:start position:0% +naught and you can see that at time zero + + + align:start position:0% +naught and you can see that at time zero +all of those functions are positive + + align:start position:0% +all of those functions are positive + + + align:start position:0% +all of those functions are positive +right and so all those positive + + align:start position:0% + + + + align:start position:0% + +contributions to that sum all add up and + + align:start position:0% +contributions to that sum all add up and + + + align:start position:0% +contributions to that sum all add up and +as you add them up and get a big pink + + align:start position:0% +as you add them up and get a big pink + + + align:start position:0% +as you add them up and get a big pink +that's called constructive interference + + align:start position:0% +that's called constructive interference + + + align:start position:0% +that's called constructive interference +so all those Peaks add up but in this + + align:start position:0% +so all those Peaks add up but in this + + + align:start position:0% +so all those Peaks add up but in this +and and you also get those Peaks all + + align:start position:0% +and and you also get those Peaks all + + + align:start position:0% +and and you also get those Peaks all +adding up one period away right + + align:start position:0% +adding up one period away right + + + align:start position:0% +adding up one period away right +one period of cosine Omega not you can + + align:start position:0% +one period of cosine Omega not you can + + + align:start position:0% +one period of cosine Omega not you can +see they add up again so you can see + + align:start position:0% +see they add up again so you can see + + + align:start position:0% +see they add up again so you can see +this is a periodic function in this in + + align:start position:0% +this is a periodic function in this in + + + align:start position:0% +this is a periodic function in this in +this time window between those Peaks you + + align:start position:0% +this time window between those Peaks you + + + align:start position:0% +this time window between those Peaks you +can see that you have positive peaks of + + align:start position:0% +can see that you have positive peaks of + + + align:start position:0% +can see that you have positive peaks of +some of those cosines negative Peaks + + align:start position:0% +some of those cosines negative Peaks + + + align:start position:0% +some of those cosines negative Peaks +positive negative they just sort of all + + align:start position:0% +positive negative they just sort of all + + + align:start position:0% +positive negative they just sort of all +add up they interfere with with each + + align:start position:0% +add up they interfere with with each + + + align:start position:0% +add up they interfere with with each +other destructively to give you a zero + + align:start position:0% +other destructively to give you a zero + + + align:start position:0% +other destructively to give you a zero +in the intervals between the peaks + + align:start position:0% +in the intervals between the peaks + + + align:start position:0% +in the intervals between the peaks +does that make sense and so basically by + + align:start position:0% +does that make sense and so basically by + + + align:start position:0% +does that make sense and so basically by +choosing the amplitudes of these + + align:start position:0% +choosing the amplitudes of these + + + align:start position:0% +choosing the amplitudes of these +different cosine functions you can + + align:start position:0% +different cosine functions you can + + + align:start position:0% +different cosine functions you can +basically build any arbitrary function + + align:start position:0% +basically build any arbitrary function + + + align:start position:0% +basically build any arbitrary function +periodic function down here that makes + + align:start position:0% +periodic function down here that makes + + + align:start position:0% +periodic function down here that makes +sense okay all right + + align:start position:0% +sense okay all right + + + align:start position:0% +sense okay all right +there's one more element that we need to + + align:start position:0% +there's one more element that we need to + + + align:start position:0% +there's one more element that we need to +add here for our Fourier series for even + + align:start position:0% +add here for our Fourier series for even + + + align:start position:0% +add here for our Fourier series for even +functions anybody have any idea what + + align:start position:0% +functions anybody have any idea what + + + align:start position:0% +functions anybody have any idea what +that is notice here I've shifted this + + align:start position:0% +that is notice here I've shifted this + + + align:start position:0% +that is notice here I've shifted this +function up a little bit so it's not + + align:start position:0% +function up a little bit so it's not + + + align:start position:0% +function up a little bit so it's not +centered at zero a constant term was + + align:start position:0% +centered at zero a constant term was + + + align:start position:0% +centered at zero a constant term was +called a DC term okay we basically take + + align:start position:0% +called a DC term okay we basically take + + + align:start position:0% +called a DC term okay we basically take +the average of that function we add it + + align:start position:0% +the average of that function we add it + + + align:start position:0% +the average of that function we add it +here that's called a DC term okay a + + align:start position:0% +here that's called a DC term okay a + + + align:start position:0% +here that's called a DC term okay a +naught over two is essentially the + + align:start position:0% +naught over two is essentially the + + + align:start position:0% +naught over two is essentially the +average of the function we're trying to + + align:start position:0% +average of the function we're trying to + + + align:start position:0% +average of the function we're trying to +approximate okay all right good we can + + align:start position:0% +approximate okay all right good we can + + + align:start position:0% +approximate okay all right good we can +now write that as a sum why even of T + + align:start position:0% +now write that as a sum why even of T + + + align:start position:0% +now write that as a sum why even of T +equals a naught over two plus a sum over + + align:start position:0% +equals a naught over two plus a sum over + + + align:start position:0% +equals a naught over two plus a sum over +all these different ends of a sub n + + align:start position:0% +all these different ends of a sub n + + + align:start position:0% +all these different ends of a sub n +which is a coefficient times cosine n + + align:start position:0% +which is a coefficient times cosine n + + + align:start position:0% +which is a coefficient times cosine n +Omega naught T Omega naught is 1 over + + align:start position:0% +Omega naught T Omega naught is 1 over + + + align:start position:0% +Omega naught T Omega naught is 1 over +there's 2 pi over this this time + + align:start position:0% +there's 2 pi over this this time + + + align:start position:0% +there's 2 pi over this this time +interval here the periodicity okay all + + align:start position:0% +interval here the periodicity okay all + + + align:start position:0% +interval here the periodicity okay all +right good how do we find those + + align:start position:0% +right good how do we find those + + + align:start position:0% +right good how do we find those +coefficients so I just told you that the + + align:start position:0% +coefficients so I just told you that the + + + align:start position:0% +coefficients so I just told you that the +first coefficient the a naught over 2 is + + align:start position:0% +first coefficient the a naught over 2 is + + + align:start position:0% +first coefficient the a naught over 2 is +just the average of our function T over + + align:start position:0% +just the average of our function T over + + + align:start position:0% +just the average of our function T over +one time window from minus T over 2 to + + align:start position:0% +one time window from minus T over 2 to + + + align:start position:0% +one time window from minus T over 2 to +plus T over 2 it's just the integral of + + align:start position:0% +plus T over 2 it's just the integral of + + + align:start position:0% +plus T over 2 it's just the integral of +that function over one period divided by + + align:start position:0% +that function over one period divided by + + + align:start position:0% +that function over one period divided by +T and that gives you the average which + + align:start position:0% +T and that gives you the average which + + + align:start position:0% +T and that gives you the average which +is a naught over 2 all right any + + align:start position:0% +is a naught over 2 all right any + + + align:start position:0% +is a naught over 2 all right any +questions about that it's pretty + + align:start position:0% +questions about that it's pretty + + + align:start position:0% +questions about that it's pretty +straightforward what about this next + + align:start position:0% +straightforward what about this next + + + align:start position:0% +straightforward what about this next +coefficient a 1 so the a 1 coefficient + + align:start position:0% +coefficient a 1 so the a 1 coefficient + + + align:start position:0% +coefficient a 1 so the a 1 coefficient +is just the overlap of our function y of + + align:start position:0% +is just the overlap of our function y of + + + align:start position:0% +is just the overlap of our function y of +T with + + align:start position:0% +T with + + + align:start position:0% +T with +this cosine okay we're just we're just + + align:start position:0% +this cosine okay we're just we're just + + + align:start position:0% +this cosine okay we're just we're just +multiplying why not + + align:start position:0% +multiplying why not + + + align:start position:0% +multiplying why not +times cosine of Omega naught T + + align:start position:0% +times cosine of Omega naught T + + + align:start position:0% +times cosine of Omega naught T +integrating over time and then + + align:start position:0% +integrating over time and then + + + align:start position:0% +integrating over time and then +multiplying by 2 over T ok so that's + + align:start position:0% +multiplying by 2 over T ok so that's + + + align:start position:0% +multiplying by 2 over T ok so that's +that's the answer + + align:start position:0% +that's the answer + + + align:start position:0% +that's the answer +and I'm gonna explain why that is okay + + align:start position:0% + + + + align:start position:0% + +that is just a correlation right it's + + align:start position:0% +that is just a correlation right it's + + + align:start position:0% +that is just a correlation right it's +it's just like asking how much - let's + + align:start position:0% +it's just like asking how much - let's + + + align:start position:0% +it's just like asking how much - let's +say we had a neuron with a receptive + + align:start position:0% +say we had a neuron with a receptive + + + align:start position:0% +say we had a neuron with a receptive +field of cosine Omega naught T we're + + align:start position:0% +field of cosine Omega naught T we're + + + align:start position:0% +field of cosine Omega naught T we're +asking how well does our signal overlap + + align:start position:0% +asking how well does our signal overlap + + + align:start position:0% +asking how well does our signal overlap +with that receptive field does that make + + align:start position:0% +with that receptive field does that make + + + align:start position:0% +with that receptive field does that make +sense we're just correlating our signal + + align:start position:0% +sense we're just correlating our signal + + + align:start position:0% +sense we're just correlating our signal +with some basis function with some + + align:start position:0% +with some basis function with some + + + align:start position:0% +with some basis function with some +receptive field and we're asking how + + align:start position:0% +receptive field and we're asking how + + + align:start position:0% +receptive field and we're asking how +much overlap is there okay + + align:start position:0% +much overlap is there okay + + + align:start position:0% +much overlap is there okay +the a2 coefficient is just the overlap + + align:start position:0% +the a2 coefficient is just the overlap + + + align:start position:0% +the a2 coefficient is just the overlap +of the function y with cosine 2 Omega + + align:start position:0% +of the function y with cosine 2 Omega + + + align:start position:0% +of the function y with cosine 2 Omega +naught T and the a sub n coefficient is + + align:start position:0% +naught T and the a sub n coefficient is + + + align:start position:0% +naught T and the a sub n coefficient is +just the overlap with cosine n Omega + + align:start position:0% +just the overlap with cosine n Omega + + + align:start position:0% +just the overlap with cosine n Omega +naught T ok just like that and you can + + align:start position:0% +naught T ok just like that and you can + + + align:start position:0% +naught T ok just like that and you can +see that that this average that we took + + align:start position:0% +see that that this average that we took + + + align:start position:0% +see that that this average that we took +up here just is the generalization of + + align:start position:0% +up here just is the generalization of + + + align:start position:0% +up here just is the generalization of +this - the overlap of our function - + + align:start position:0% +this - the overlap of our function - + + + align:start position:0% +this - the overlap of our function - +cosine 0 Omega naught T cosine 0 Omega + + align:start position:0% +cosine 0 Omega naught T cosine 0 Omega + + + align:start position:0% +cosine 0 Omega naught T cosine 0 Omega +naught T is just 1 right and so this + + align:start position:0% +naught T is just 1 right and so this + + + align:start position:0% +naught T is just 1 right and so this +coefficient a naught is just looks the + + align:start position:0% +coefficient a naught is just looks the + + + align:start position:0% +coefficient a naught is just looks the +same as this + + align:start position:0% +same as this + + + align:start position:0% +same as this +it's just that in this case it turns out + + align:start position:0% +it's just that in this case it turns out + + + align:start position:0% +it's just that in this case it turns out +to be the average of the function okay + + align:start position:0% +to be the average of the function okay + + + align:start position:0% +to be the average of the function okay +any questions about that okay so that is + + align:start position:0% +any questions about that okay so that is + + + align:start position:0% +any questions about that okay so that is +in general how you calculate those + + align:start position:0% +in general how you calculate those + + + align:start position:0% +in general how you calculate those +coefficients so you would literally just + + align:start position:0% +coefficients so you would literally just + + + align:start position:0% +coefficients so you would literally just +take your function multiply it by a + + align:start position:0% +take your function multiply it by a + + + align:start position:0% +take your function multiply it by a +cosine of some frequency integrate it + + align:start position:0% +cosine of some frequency integrate it + + + align:start position:0% +cosine of some frequency integrate it +and that's the answer okay all right + + align:start position:0% +and that's the answer okay all right + + + align:start position:0% +and that's the answer okay all right +let's just take a look at what some of + + align:start position:0% +let's just take a look at what some of + + + align:start position:0% +let's just take a look at what some of +these coefficients are for some really + + align:start position:0% +these coefficients are for some really + + + align:start position:0% +these coefficients are for some really +simple functions okay + + align:start position:0% +simple functions okay + + + align:start position:0% +simple functions okay +so there I've rewritten what each of + + align:start position:0% +so there I've rewritten what each of + + + align:start position:0% +so there I've rewritten what each of +those coefficients is as an integral and + + align:start position:0% +those coefficients is as an integral and + + + align:start position:0% +those coefficients is as an integral and +now let's consider the following + + align:start position:0% +now let's consider the following + + + align:start position:0% +now let's consider the following +function so let's say our function is 1 + + align:start position:0% +function so let's say our function is 1 + + + align:start position:0% +function so let's say our function is 1 +it's just a constant at 1 so you can see + + align:start position:0% +it's just a constant at 1 so you can see + + + align:start position:0% +it's just a constant at 1 so you can see +that this integral right from minus T + + align:start position:0% +that this integral right from minus T + + + align:start position:0% +that this integral right from minus T +over 2 to T over 2 that integral is just + + align:start position:0% +over 2 to T over 2 that integral is just + + + align:start position:0% +over 2 to T over 2 that integral is just +T multiplied by 2 over T gives that + + align:start position:0% +T multiplied by 2 over T gives that + + + align:start position:0% +T multiplied by 2 over T gives that +coefficient is just 2 okay if our + + align:start position:0% +coefficient is just 2 okay if our + + + align:start position:0% +coefficient is just 2 okay if our +function is cosine Omega naught T you + + align:start position:0% +function is cosine Omega naught T you + + + align:start position:0% +function is cosine Omega naught T you +can see that if you put a cosine in here + + align:start position:0% +can see that if you put a cosine in here + + + align:start position:0% +can see that if you put a cosine in here +that averages to 0 if you put a cosine + + align:start position:0% +that averages to 0 if you put a cosine + + + align:start position:0% +that averages to 0 if you put a cosine +in here you get cosine squared the + + align:start position:0% +in here you get cosine squared the + + + align:start position:0% +in here you get cosine squared the +integral of cosine squared is just it's + + align:start position:0% +integral of cosine squared is just it's + + + align:start position:0% +integral of cosine squared is just it's +it's just half of the you know basically + + align:start position:0% +it's just half of the you know basically + + + align:start position:0% +it's just half of the you know basically +the full range so that's just T over 2 + + align:start position:0% +the full range so that's just T over 2 + + + align:start position:0% +the full range so that's just T over 2 +when you multiply by 2 over T you get 1 + + align:start position:0% +when you multiply by 2 over T you get 1 + + + align:start position:0% +when you multiply by 2 over T you get 1 +okay and the coefficient a 2 for a + + align:start position:0% +okay and the coefficient a 2 for a + + + align:start position:0% +okay and the coefficient a 2 for a +function cosine Omega T is 0 because the + + align:start position:0% +function cosine Omega T is 0 because the + + + align:start position:0% +function cosine Omega T is 0 because the +integral of cosine Omega naught T times + + align:start position:0% +integral of cosine Omega naught T times + + + align:start position:0% +integral of cosine Omega naught T times +cosine 2 Omega naught T is 0 ok all + + align:start position:0% +cosine 2 Omega naught T is 0 ok all + + + align:start position:0% +cosine 2 Omega naught T is 0 ok all +right if we have a function cosine 2 + + align:start position:0% +right if we have a function cosine 2 + + + align:start position:0% +right if we have a function cosine 2 +Omega naught T then these coefficients + + align:start position:0% +Omega naught T then these coefficients + + + align:start position:0% +Omega naught T then these coefficients +are 0 and that coefficient is 1 you can + + align:start position:0% +are 0 and that coefficient is 1 you can + + + align:start position:0% +are 0 and that coefficient is 1 you can +see that you have this interesting thing + + align:start position:0% +see that you have this interesting thing + + + align:start position:0% +see that you have this interesting thing +here if your function is cosine Omega + + align:start position:0% +here if your function is cosine Omega + + + align:start position:0% +here if your function is cosine Omega +naught T then the only coefficient + + align:start position:0% +naught T then the only coefficient + + + align:start position:0% +naught T then the only coefficient +that's nonzero is the one that you're + + align:start position:0% +that's nonzero is the one that you're + + + align:start position:0% +that's nonzero is the one that you're +overlapping with cosine Omega naught T + + align:start position:0% +overlapping with cosine Omega naught T + + + align:start position:0% +overlapping with cosine Omega naught T +it's it's this only this first + + align:start position:0% +it's it's this only this first + + + align:start position:0% +it's it's this only this first +coefficient that's nonzero if your + + align:start position:0% +coefficient that's nonzero if your + + + align:start position:0% +coefficient that's nonzero if your +function has frequencies a frequency 2 + + align:start position:0% +function has frequencies a frequency 2 + + + align:start position:0% +function has frequencies a frequency 2 +Omega naught T then the only coefficient + + align:start position:0% +Omega naught T then the only coefficient + + + align:start position:0% +Omega naught T then the only coefficient +that's nonzero is the a two okay so what + + align:start position:0% +that's nonzero is the a two okay so what + + + align:start position:0% +that's nonzero is the a two okay so what +that means is that if the function has + + align:start position:0% +that means is that if the function has + + + align:start position:0% +that means is that if the function has +maximal overlap if it overlaps one of + + align:start position:0% +maximal overlap if it overlaps one of + + + align:start position:0% +maximal overlap if it overlaps one of +those cosines then it has zero overlap + + align:start position:0% +those cosines then it has zero overlap + + + align:start position:0% +those cosines then it has zero overlap +with all the others and we can say that + + align:start position:0% +with all the others and we can say that + + + align:start position:0% +with all the others and we can say that +that set of cosine functions cosine + + align:start position:0% +that set of cosine functions cosine + + + align:start position:0% +that set of cosine functions cosine +Omega naught T cosine 2 Omega naught T + + align:start position:0% +Omega naught T cosine 2 Omega naught T + + + align:start position:0% +Omega naught T cosine 2 Omega naught T +forms what's called an orthogonal basis + + align:start position:0% +forms what's called an orthogonal basis + + + align:start position:0% +forms what's called an orthogonal basis +set we're gonna spend a lot of time + + align:start position:0% +set we're gonna spend a lot of time + + + align:start position:0% +set we're gonna spend a lot of time +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +basis set later but I've just gonna + + align:start position:0% +basis set later but I've just gonna + + + align:start position:0% +basis set later but I've just gonna +throw this word out to you so that + + align:start position:0% +throw this word out to you so that + + + align:start position:0% +throw this word out to you so that +you've heard it when I come back to the + + align:start position:0% +you've heard it when I come back to the + + + align:start position:0% +you've heard it when I come back to the +idea of basis sets later you're gonna + + align:start position:0% +idea of basis sets later you're gonna + + + align:start position:0% +idea of basis sets later you're gonna +see this connection okay so the basic + + align:start position:0% +see this connection okay so the basic + + + align:start position:0% +see this connection okay so the basic +idea is that what we're doing is we're + + align:start position:0% +idea is that what we're doing is we're + + + align:start position:0% +idea is that what we're doing is we're +taking our signal which is a vector it's + + align:start position:0% +taking our signal which is a vector it's + + + align:start position:0% +taking our signal which is a vector it's +a set of points in time we can think of + + align:start position:0% +a set of points in time we can think of + + + align:start position:0% +a set of points in time we can think of +that as a vector in a high dimensional + + align:start position:0% +that as a vector in a high dimensional + + + align:start position:0% +that as a vector in a high dimensional +space and we're simply expressing it in + + align:start position:0% +space and we're simply expressing it in + + + align:start position:0% +space and we're simply expressing it in +a new basis set okay of cosines of + + align:start position:0% +a new basis set okay of cosines of + + + align:start position:0% +a new basis set okay of cosines of +different frequencies so each of those + + align:start position:0% +different frequencies so each of those + + + align:start position:0% +different frequencies so each of those +functions cosine n Omega T is like a + + align:start position:0% +functions cosine n Omega T is like a + + + align:start position:0% +functions cosine n Omega T is like a +vector in a basis set our signal like a + + align:start position:0% +vector in a basis set our signal like a + + + align:start position:0% +vector in a basis set our signal like a +vector and what we're doing is when + + align:start position:0% +vector and what we're doing is when + + + align:start position:0% +vector and what we're doing is when +we're doing these projections + + align:start position:0% +we're doing these projections + + + align:start position:0% +we're doing these projections +we're simply computing the projection of + + align:start position:0% +we're simply computing the projection of + + + align:start position:0% +we're simply computing the projection of +our of that vector our signal onto these + + align:start position:0% +our of that vector our signal onto these + + + align:start position:0% +our of that vector our signal onto these +different basis functions these + + align:start position:0% +different basis functions these + + + align:start position:0% +different basis functions these +different basis vectors okay so we're + + align:start position:0% +different basis vectors okay so we're + + + align:start position:0% +different basis vectors okay so we're +just finding the Proficient so that we + + align:start position:0% +just finding the Proficient so that we + + + align:start position:0% +just finding the Proficient so that we +can express our signal as a sum of a + + align:start position:0% +can express our signal as a sum of a + + + align:start position:0% +can express our signal as a sum of a +coefficient times a basis vector plus + + align:start position:0% +coefficient times a basis vector plus + + + align:start position:0% +coefficient times a basis vector plus +another coefficient times another basis + + align:start position:0% +another coefficient times another basis + + + align:start position:0% +another coefficient times another basis +vector and so on okay so for example in + + align:start position:0% +vector and so on okay so for example in + + + align:start position:0% +vector and so on okay so for example in +the simple standard basis where this + + align:start position:0% +the simple standard basis where this + + + align:start position:0% +the simple standard basis where this +vector is 0 1 and that vector is 1 0 you + + align:start position:0% +vector is 0 1 and that vector is 1 0 you + + + align:start position:0% +vector is 0 1 and that vector is 1 0 you +can write down an arbitrary vector as a + + align:start position:0% +can write down an arbitrary vector as a + + + align:start position:0% +can write down an arbitrary vector as a +coefficient times this plus another + + align:start position:0% +coefficient times this plus another + + + align:start position:0% +coefficient times this plus another +coefficient times that that makes sense + + align:start position:0% +coefficient times that that makes sense + + + align:start position:0% +coefficient times that that makes sense +ok and how do we find those coefficients + + align:start position:0% +ok and how do we find those coefficients + + + align:start position:0% +ok and how do we find those coefficients +we just take our vector and dot it onto + + align:start position:0% +we just take our vector and dot it onto + + + align:start position:0% +we just take our vector and dot it onto +each one of these basis vectors X x2 + + align:start position:0% +each one of these basis vectors X x2 + + + align:start position:0% +each one of these basis vectors X x2 +that make sense ok you don't you don't + + align:start position:0% +that make sense ok you don't you don't + + + align:start position:0% +that make sense ok you don't you don't +need to like know this for this section + + align:start position:0% +need to like know this for this section + + + align:start position:0% +need to like know this for this section +ok but we're gonna come back to so I + + align:start position:0% +ok but we're gonna come back to so I + + + align:start position:0% +ok but we're gonna come back to so I +would like you to eventually kind of + + align:start position:0% +would like you to eventually kind of + + + align:start position:0% +would like you to eventually kind of +combine these views of taking signals + + align:start position:0% +combine these views of taking signals + + + align:start position:0% +combine these views of taking signals +and and looking at projections of those + + align:start position:0% +and and looking at projections of those + + + align:start position:0% +and and looking at projections of those +into new basis sets ok and as you know + + align:start position:0% +into new basis sets ok and as you know + + + align:start position:0% +into new basis sets ok and as you know +how you see things depends on how you're + + align:start position:0% +how you see things depends on how you're + + + align:start position:0% +how you see things depends on how you're +looking at them the direction that you + + align:start position:0% +looking at them the direction that you + + + align:start position:0% +looking at them the direction that you +look at them that's what we're doing + + align:start position:0% +look at them that's what we're doing + + + align:start position:0% +look at them that's what we're doing +when we take a signal and we project it + + align:start position:0% +when we take a signal and we project it + + + align:start position:0% +when we take a signal and we project it +onto a function + + align:start position:0% +onto a function + + + align:start position:0% +onto a function +we're taking a particular view of that + + align:start position:0% +we're taking a particular view of that + + + align:start position:0% +we're taking a particular view of that +function okay so so as you know the view + + align:start position:0% +function okay so so as you know the view + + + align:start position:0% +function okay so so as you know the view +you have on something has a big impact + + align:start position:0% +you have on something has a big impact + + + align:start position:0% +you have on something has a big impact +on what you see right + + align:start position:0% + + + + align:start position:0% + +so that's all we're doing is we're + + align:start position:0% +so that's all we're doing is we're + + + align:start position:0% +so that's all we're doing is we're +taking functions and finding the + + align:start position:0% +taking functions and finding the + + + align:start position:0% +taking functions and finding the +projection on which we can see something + + align:start position:0% +projection on which we can see something + + + align:start position:0% +projection on which we can see something +interesting okay that's it that's all + + align:start position:0% +interesting okay that's it that's all + + + align:start position:0% +interesting okay that's it that's all +spectral analysis is and the particular + + align:start position:0% +spectral analysis is and the particular + + + align:start position:0% +spectral analysis is and the particular +views we're looking at are projections + + align:start position:0% +views we're looking at are projections + + + align:start position:0% +views we're looking at are projections +on two different periodic functions + + align:start position:0% +on two different periodic functions + + + align:start position:0% +on two different periodic functions +okay cosines of different frequencies + + align:start position:0% +okay cosines of different frequencies + + + align:start position:0% +okay cosines of different frequencies +all right and what you find is that for + + align:start position:0% +all right and what you find is that for + + + align:start position:0% +all right and what you find is that for +periodic signals there are certain views + + align:start position:0% +periodic signals there are certain views + + + align:start position:0% +periodic signals there are certain views +where something magically pops out and + + align:start position:0% +where something magically pops out and + + + align:start position:0% +where something magically pops out and +you see what's there that you can't see + + align:start position:0% +you see what's there that you can't see + + + align:start position:0% +you see what's there that you can't see +when you just look at the time domain + + align:start position:0% +when you just look at the time domain + + + align:start position:0% +when you just look at the time domain +okay all right so we we looked at even + + align:start position:0% +okay all right so we we looked at even + + + align:start position:0% +okay all right so we we looked at even +functions or symmetric functions now + + align:start position:0% +functions or symmetric functions now + + + align:start position:0% +functions or symmetric functions now +let's take a look at odd functions or + + align:start position:0% +let's take a look at odd functions or + + + align:start position:0% +let's take a look at odd functions or +anti-symmetric functions these are + + align:start position:0% +anti-symmetric functions these are + + + align:start position:0% +anti-symmetric functions these are +called odd because the odd polynomials + + align:start position:0% +called odd because the odd polynomials + + + align:start position:0% +called odd because the odd polynomials +you know like X cubed looks like this if + + align:start position:0% +you know like X cubed looks like this if + + + align:start position:0% +you know like X cubed looks like this if +it's negative on one side it's positive + + align:start position:0% +it's negative on one side it's positive + + + align:start position:0% +it's negative on one side it's positive +on the other side same here if it's + + align:start position:0% +on the other side same here if it's + + + align:start position:0% +on the other side same here if it's +negative here then it's positive there + + align:start position:0% +negative here then it's positive there + + + align:start position:0% +negative here then it's positive there +okay so we can we can now write down + + align:start position:0% +okay so we can we can now write down + + + align:start position:0% +okay so we can we can now write down +Fourier series for odd or anti-symmetric + + align:start position:0% +Fourier series for odd or anti-symmetric + + + align:start position:0% +Fourier series for odd or anti-symmetric +functions what do you think we're gonna + + align:start position:0% +functions what do you think we're gonna + + + align:start position:0% +functions what do you think we're gonna +use instead of cosines we're gonna use + + align:start position:0% +use instead of cosines we're gonna use + + + align:start position:0% +use instead of cosines we're gonna use +signs because signs symmetric around + + align:start position:0% +signs because signs symmetric around + + + align:start position:0% +signs because signs symmetric around +anti symmetric around the origin okay + + align:start position:0% +anti symmetric around the origin okay + + + align:start position:0% +anti symmetric around the origin okay +and we're still going to consider + + align:start position:0% +and we're still going to consider + + + align:start position:0% +and we're still going to consider +functions that are periodic was period t + + align:start position:0% +functions that are periodic was period t + + + align:start position:0% +functions that are periodic was period t +we can take any anti symmetric function + + align:start position:0% +we can take any anti symmetric function + + + align:start position:0% +we can take any anti symmetric function +and approximate approximate it as a sum + + align:start position:0% +and approximate approximate it as a sum + + + align:start position:0% +and approximate approximate it as a sum +of sine waves of frequency to PI over T + + align:start position:0% +of sine waves of frequency to PI over T + + + align:start position:0% +of sine waves of frequency to PI over T +or again Omega naught all right and + + align:start position:0% +or again Omega naught all right and + + + align:start position:0% +or again Omega naught all right and +integer multiples of that Omega naught + + align:start position:0% +integer multiples of that Omega naught + + + align:start position:0% +integer multiples of that Omega naught +okay all right so again our odd + + align:start position:0% +okay all right so again our odd + + + align:start position:0% +okay all right so again our odd +functions can be approximated as a sum + + align:start position:0% +functions can be approximated as a sum + + + align:start position:0% +functions can be approximated as a sum +of components contributions of different + + align:start position:0% +of components contributions of different + + + align:start position:0% +of components contributions of different +frequencies with a coefficient times + + align:start position:0% +frequencies with a coefficient times + + + align:start position:0% +frequencies with a coefficient times +sine of Omega naught T plus another + + align:start position:0% +sine of Omega naught T plus another + + + align:start position:0% +sine of Omega naught T plus another +coefficient times sine of 2 Omega naught + + align:start position:0% +coefficient times sine of 2 Omega naught + + + align:start position:0% +coefficient times sine of 2 Omega naught +T and so on and we can write that as a + + align:start position:0% +T and so on and we can write that as a + + + align:start position:0% +T and so on and we can write that as a +sum that looks like this so a sum over n + + align:start position:0% +sum that looks like this so a sum over n + + + align:start position:0% +sum that looks like this so a sum over n +from one to infinity a coefficient B sub + + align:start position:0% +from one to infinity a coefficient B sub + + + align:start position:0% +from one to infinity a coefficient B sub +n times sine of n Omega naught T + + align:start position:0% + + + + align:start position:0% + +okay and why is there no DC term here + + align:start position:0% + + + + align:start position:0% + +good because as an anti-symmetric + + align:start position:0% +good because as an anti-symmetric + + + align:start position:0% +good because as an anti-symmetric +function can't have a DC offset okay + + align:start position:0% +function can't have a DC offset okay + + + align:start position:0% +function can't have a DC offset okay +okay so for arbitrary functions you can + + align:start position:0% +okay so for arbitrary functions you can + + + align:start position:0% +okay so for arbitrary functions you can +write down any arbitrary periodic + + align:start position:0% +write down any arbitrary periodic + + + align:start position:0% +write down any arbitrary periodic +function as the sum of a symmetric part + + align:start position:0% +function as the sum of a symmetric part + + + align:start position:0% +function as the sum of a symmetric part +and an anti-symmetric part so we can + + align:start position:0% +and an anti-symmetric part so we can + + + align:start position:0% +and an anti-symmetric part so we can +write down an arbitrary function as a + + align:start position:0% +write down an arbitrary function as a + + + align:start position:0% +write down an arbitrary function as a +sum of this these cosines plus a sum of + + align:start position:0% +sum of this these cosines plus a sum of + + + align:start position:0% +sum of this these cosines plus a sum of +sine waves okay so that's for a series + + align:start position:0% +sine waves okay so that's for a series + + + align:start position:0% +sine waves okay so that's for a series +any questions about that okay + + align:start position:0% +any questions about that okay + + + align:start position:0% +any questions about that okay +so this is kind of messy and it turns + + align:start position:0% +so this is kind of messy and it turns + + + align:start position:0% +so this is kind of messy and it turns +out that there's a much simpler way of + + align:start position:0% +out that there's a much simpler way of + + + align:start position:0% +out that there's a much simpler way of +writing out functions as sums of + + align:start position:0% +writing out functions as sums of + + + align:start position:0% +writing out functions as sums of +periodic functions okay + + align:start position:0% +periodic functions okay + + + align:start position:0% +periodic functions okay +so rather than using cosines and sines + + align:start position:0% +so rather than using cosines and sines + + + align:start position:0% +so rather than using cosines and sines +we're going to use complex Exponential's + + align:start position:0% +we're going to use complex Exponential's + + + align:start position:0% +we're going to use complex Exponential's +okay and that is what complex fourier + + align:start position:0% +okay and that is what complex fourier + + + align:start position:0% +okay and that is what complex fourier +series does okay all right so let's do + + align:start position:0% +series does okay all right so let's do + + + align:start position:0% +series does okay all right so let's do +that so you probably recall that you can + + align:start position:0% +that so you probably recall that you can + + + align:start position:0% +that so you probably recall that you can +write down a complex exponential e to + + align:start position:0% +write down a complex exponential e to + + + align:start position:0% +write down a complex exponential e to +the I Omega T as a cosine Omega T plus I + + align:start position:0% +the I Omega T as a cosine Omega T plus I + + + align:start position:0% +the I Omega T as a cosine Omega T plus I +sine Omega T all right so e to the I + + align:start position:0% +sine Omega T all right so e to the I + + + align:start position:0% +sine Omega T all right so e to the I +Omega T is just a generalization of + + align:start position:0% +Omega T is just a generalization of + + + align:start position:0% +Omega T is just a generalization of +sines and cosines alright so the way to + + align:start position:0% +sines and cosines alright so the way to + + + align:start position:0% +sines and cosines alright so the way to +think about this is e to the I Omega T + + align:start position:0% +think about this is e to the I Omega T + + + align:start position:0% +think about this is e to the I Omega T +is a complex number if we plot it in + + align:start position:0% +is a complex number if we plot it in + + + align:start position:0% +is a complex number if we plot it in +complex plane where we look at the real + + align:start position:0% +complex plane where we look at the real + + + align:start position:0% +complex plane where we look at the real +part along this axis the imaginary part + + align:start position:0% +part along this axis the imaginary part + + + align:start position:0% +part along this axis the imaginary part +along that axis e to the I Omega T just + + align:start position:0% +along that axis e to the I Omega T just + + + align:start position:0% +along that axis e to the I Omega T just +lives on this circle no matter what + + align:start position:0% +lives on this circle no matter what + + + align:start position:0% +lives on this circle no matter what +Omega T is e to the I Omega T just sits + + align:start position:0% +Omega T is e to the I Omega T just sits + + + align:start position:0% +Omega T is e to the I Omega T just sits +on this circle in the complex plane the + + align:start position:0% +on this circle in the complex plane the + + + align:start position:0% +on this circle in the complex plane the +unit circle in the complex plane + + align:start position:0% +unit circle in the complex plane + + + align:start position:0% +unit circle in the complex plane +e to the I Omega T is a function of time + + align:start position:0% +e to the I Omega T is a function of time + + + align:start position:0% +e to the I Omega T is a function of time +it simply has a real part that looks + + align:start position:0% +it simply has a real part that looks + + + align:start position:0% +it simply has a real part that looks +like cosine so the real part of this as + + align:start position:0% +like cosine so the real part of this as + + + align:start position:0% +like cosine so the real part of this as +you increase T or the phase Omega T is + + align:start position:0% +you increase T or the phase Omega T is + + + align:start position:0% +you increase T or the phase Omega T is +the real part just oscillates + + align:start position:0% +the real part just oscillates + + + align:start position:0% +the real part just oscillates +sinusoidally back and forth like this as + + align:start position:0% +sinusoidally back and forth like this as + + + align:start position:0% +sinusoidally back and forth like this as +a cosine the imaginary part just + + align:start position:0% +a cosine the imaginary part just + + + align:start position:0% +a cosine the imaginary part just +oscillates back and forth as a sine + + align:start position:0% +oscillates back and forth as a sine + + + align:start position:0% +oscillates back and forth as a sine +right and when you put them together + + align:start position:0% +right and when you put them together + + + align:start position:0% +right and when you put them together +something that goes back and forth this + + align:start position:0% +something that goes back and forth this + + + align:start position:0% +something that goes back and forth this +way as a cosine up and down that way as + + align:start position:0% +way as a cosine up and down that way as + + + align:start position:0% +way as a cosine up and down that way as +a sine just traces out a circle so e to + + align:start position:0% +a sine just traces out a circle so e to + + + align:start position:0% +a sine just traces out a circle so e to +the I Omega T traces out a circle in + + align:start position:0% +the I Omega T traces out a circle in + + + align:start position:0% +the I Omega T traces out a circle in +this direction and as time increases it + + align:start position:0% +this direction and as time increases it + + + align:start position:0% +this direction and as time increases it +just goes around and around like this e + + align:start position:0% +just goes around and around like this e + + + align:start position:0% +just goes around and around like this e +to the minus IO T I Omega T just goes + + align:start position:0% +to the minus IO T I Omega T just goes + + + align:start position:0% +to the minus IO T I Omega T just goes +the other way okay that makes sense + + align:start position:0% +the other way okay that makes sense + + + align:start position:0% +the other way okay that makes sense +got to the the real part that's going + + align:start position:0% +got to the the real part that's going + + + align:start position:0% +got to the the real part that's going +like this the imaginary part that's + + align:start position:0% +like this the imaginary part that's + + + align:start position:0% +like this the imaginary part that's +going like this alright and you put + + align:start position:0% +going like this alright and you put + + + align:start position:0% +going like this alright and you put +those together and they just go around + + align:start position:0% +those together and they just go around + + + align:start position:0% +those together and they just go around +in a circle okay so you can see it's a + + align:start position:0% +in a circle okay so you can see it's a + + + align:start position:0% +in a circle okay so you can see it's a +way of combining cosine and sine + + align:start position:0% +way of combining cosine and sine + + + align:start position:0% +way of combining cosine and sine +together in one function okay so what + + align:start position:0% +together in one function okay so what + + + align:start position:0% +together in one function okay so what +we're going to do is we're going to + + align:start position:0% +we're going to do is we're going to + + + align:start position:0% +we're going to do is we're going to +rewrite our Fourier series as instead of + + align:start position:0% +rewrite our Fourier series as instead of + + + align:start position:0% +rewrite our Fourier series as instead of +sines and cosines we're going to stick + + align:start position:0% +sines and cosines we're going to stick + + + align:start position:0% +sines and cosines we're going to stick +in each of the we're going to replace + + align:start position:0% +in each of the we're going to replace + + + align:start position:0% +in each of the we're going to replace +the sines and cosines + + align:start position:0% +the sines and cosines + + + align:start position:0% +the sines and cosines +with e to the I Omega T and e to the + + align:start position:0% +with e to the I Omega T and e to the + + + align:start position:0% +with e to the I Omega T and e to the +minus I Omega T so we're just gonna + + align:start position:0% +minus I Omega T so we're just gonna + + + align:start position:0% +minus I Omega T so we're just gonna +solve these two functions for cosine and + + align:start position:0% +solve these two functions for cosine and + + + align:start position:0% +solve these two functions for cosine and +sine and we're gonna take this and plug + + align:start position:0% +sine and we're gonna take this and plug + + + align:start position:0% +sine and we're gonna take this and plug +it into our our Fourier series and see + + align:start position:0% +it into our our Fourier series and see + + + align:start position:0% +it into our our Fourier series and see +what we get okay so let's do that and + + align:start position:0% +what we get okay so let's do that and + + + align:start position:0% +what we get okay so let's do that and +remember 1 over I is just minus I okay + + align:start position:0% +remember 1 over I is just minus I okay + + + align:start position:0% +remember 1 over I is just minus I okay +so here's our 4s here with our sum of + + align:start position:0% +so here's our 4s here with our sum of + + + align:start position:0% +so here's our 4s here with our sum of +cosines our sum up signs we're just + + align:start position:0% +cosines our sum up signs we're just + + + align:start position:0% +cosines our sum up signs we're just +going to replace those things with the e + + align:start position:0% +going to replace those things with the e + + + align:start position:0% +going to replace those things with the e +to the I Omega T plus e to the minus I + + align:start position:0% +to the I Omega T plus e to the minus I + + + align:start position:0% +to the I Omega T plus e to the minus I +Omega T and so on so there we go + + align:start position:0% +Omega T and so on so there we go + + + align:start position:0% +Omega T and so on so there we go +just replacing that there's a 1/2 there + + align:start position:0% +just replacing that there's a 1/2 there + + + align:start position:0% +just replacing that there's a 1/2 there +okay and now we're just going to do some + + align:start position:0% +okay and now we're just going to do some + + + align:start position:0% +okay and now we're just going to do some +algebra and we're gonna collect e to the + + align:start position:0% +algebra and we're gonna collect e to the + + + align:start position:0% +algebra and we're gonna collect e to the +I Omega T's and e to the minus I Omega + + align:start position:0% +I Omega T's and e to the minus I Omega + + + align:start position:0% +I Omega T's and e to the minus I Omega +T's together and this is what it looks + + align:start position:0% +T's together and this is what it looks + + + align:start position:0% +T's together and this is what it looks +like okay so you can see that what we're + + align:start position:0% +like okay so you can see that what we're + + + align:start position:0% +like okay so you can see that what we're +doing is collecting this into a bunch of + + align:start position:0% +doing is collecting this into a bunch of + + + align:start position:0% +doing is collecting this into a bunch of +terms that have e to the positive I and + + align:start position:0% +terms that have e to the positive I and + + + align:start position:0% +terms that have e to the positive I and +Omega T here and e to the minus I and + + align:start position:0% +Omega T here and e to the minus I and + + + align:start position:0% +Omega T here and e to the minus I and +Omega naught T there okay and now we + + align:start position:0% +Omega naught T there okay and now we + + + align:start position:0% +Omega naught T there okay and now we +have a still a sum of three things so it + + align:start position:0% +have a still a sum of three things so it + + + align:start position:0% +have a still a sum of three things so it +doesn't really look like we've really + + align:start position:0% +doesn't really look like we've really + + + align:start position:0% +doesn't really look like we've really +gotten anywhere right okay but notice + + align:start position:0% +gotten anywhere right okay but notice + + + align:start position:0% +gotten anywhere right okay but notice +something if we just put the minus sign + + align:start position:0% +something if we just put the minus sign + + + align:start position:0% +something if we just put the minus sign +into the N okay then we can combine + + align:start position:0% +into the N okay then we can combine + + + align:start position:0% +into the N okay then we can combine +these two into one sum and this if n is + + align:start position:0% +these two into one sum and this if n is + + + align:start position:0% +these two into one sum and this if n is +zero what is e to the I n Omega T it's + + align:start position:0% +zero what is e to the I n Omega T it's + + + align:start position:0% +zero what is e to the I n Omega T it's +just 1 so we can also write this as + + align:start position:0% +just 1 so we can also write this as + + + align:start position:0% +just 1 so we can also write this as +something eetu the I n Omega T as long + + align:start position:0% +something eetu the I n Omega T as long + + + align:start position:0% +something eetu the I n Omega T as long +as n is zero okay so that's what we do + + align:start position:0% +as n is zero okay so that's what we do + + + align:start position:0% +as n is zero okay so that's what we do +oh and by the way these coefficients + + align:start position:0% +oh and by the way these coefficients + + + align:start position:0% +oh and by the way these coefficients +here we can just rewrite as sums of + + align:start position:0% +here we can just rewrite as sums of + + + align:start position:0% +here we can just rewrite as sums of +those coefficients up there don't worry + + align:start position:0% +those coefficients up there don't worry + + + align:start position:0% +those coefficients up there don't worry +this all looks really complicated by the + + align:start position:0% +this all looks really complicated by the + + + align:start position:0% +this all looks really complicated by the +end it's just oil down to one simple + + align:start position:0% +end it's just oil down to one simple + + + align:start position:0% +end it's just oil down to one simple +thing that's why we're doing this we're + + align:start position:0% +thing that's why we're doing this we're + + + align:start position:0% +thing that's why we're doing this we're +simplifying things okay so when you do + + align:start position:0% +simplifying things okay so when you do + + + align:start position:0% +simplifying things okay so when you do +this when you rewrite this this looks + + align:start position:0% +this when you rewrite this this looks + + + align:start position:0% +this when you rewrite this this looks +like a sum over N equals zero this is a + + align:start position:0% +like a sum over N equals zero this is a + + + align:start position:0% +like a sum over N equals zero this is a +sum over positive ends N equals 1 to + + align:start position:0% +sum over positive ends N equals 1 to + + + align:start position:0% +sum over positive ends N equals 1 to +infinity this is a sum over negative n + + align:start position:0% +infinity this is a sum over negative n + + + align:start position:0% +infinity this is a sum over negative n +this one to minus infinity and all those + + align:start position:0% +this one to minus infinity and all those + + + align:start position:0% +this one to minus infinity and all those +combined into one sum so now we can + + align:start position:0% +combined into one sum so now we can + + + align:start position:0% +combined into one sum so now we can +write down any function y of T as a sum + + align:start position:0% +write down any function y of T as a sum + + + align:start position:0% +write down any function y of T as a sum +over N equals minus infinity to infinity + + align:start position:0% +over N equals minus infinity to infinity + + + align:start position:0% +over N equals minus infinity to infinity +of a coefficient a sub n times e to the + + align:start position:0% +of a coefficient a sub n times e to the + + + align:start position:0% +of a coefficient a sub n times e to the +I and Omega okay so we went from having + + align:start position:0% +I and Omega okay so we went from having + + + align:start position:0% +I and Omega okay so we went from having +this cut this complicated thing that sum + + align:start position:0% +this cut this complicated thing that sum + + + align:start position:0% +this cut this complicated thing that sum +over a constant term sines and cosines + + align:start position:0% +over a constant term sines and cosines + + + align:start position:0% +over a constant term sines and cosines +and we boiled it down to + + align:start position:0% +and we boiled it down to + + + align:start position:0% +and we boiled it down to +a single some that's why these these + + align:start position:0% +a single some that's why these these + + + align:start position:0% +a single some that's why these these +complex exponentials are useful okay + + align:start position:0% +complex exponentials are useful okay + + + align:start position:0% +complex exponentials are useful okay +because we don't have to carry around a + + align:start position:0% +because we don't have to carry around a + + + align:start position:0% +because we don't have to carry around a +bunch of different functions different + + align:start position:0% +bunch of different functions different + + + align:start position:0% +bunch of different functions different +basis functions to describe an arbitrary + + align:start position:0% +basis functions to describe an arbitrary + + + align:start position:0% +basis functions to describe an arbitrary +signal why okay but remember this is + + align:start position:0% +signal why okay but remember this is + + + align:start position:0% +signal why okay but remember this is +just a mathematical trick to hide sines + + align:start position:0% +just a mathematical trick to hide sines + + + align:start position:0% +just a mathematical trick to hide sines +and cosines okay it's a very powerful + + align:start position:0% +and cosines okay it's a very powerful + + + align:start position:0% +and cosines okay it's a very powerful +trick but that's all it's doing is its + + align:start position:0% +trick but that's all it's doing is its + + + align:start position:0% +trick but that's all it's doing is its +hiding sines and cosines okay + + align:start position:0% +hiding sines and cosines okay + + + align:start position:0% +hiding sines and cosines okay +all right so we've replaced our sums + + align:start position:0% +all right so we've replaced our sums + + + align:start position:0% +all right so we've replaced our sums +over cosines and sines where the sum of + + align:start position:0% +over cosines and sines where the sum of + + + align:start position:0% +over cosines and sines where the sum of +complex Exponential's alright remember + + align:start position:0% +complex Exponential's alright remember + + + align:start position:0% +complex Exponential's alright remember +what we're doing here were finding a new + + align:start position:0% +what we're doing here were finding a new + + + align:start position:0% +what we're doing here were finding a new +way of writing down functions okay so + + align:start position:0% +way of writing down functions okay so + + + align:start position:0% +way of writing down functions okay so +what's cool about this what's really + + align:start position:0% +what's cool about this what's really + + + align:start position:0% +what's cool about this what's really +interesting about this is that for some + + align:start position:0% +interesting about this is that for some + + + align:start position:0% +interesting about this is that for some +functions so what we're doing is where + + align:start position:0% +functions so what we're doing is where + + + align:start position:0% +functions so what we're doing is where +we have an arbitrary function y and + + align:start position:0% +we have an arbitrary function y and + + + align:start position:0% +we have an arbitrary function y and +we're writing it down with just some + + align:start position:0% +we're writing it down with just some + + + align:start position:0% +we're writing it down with just some +numbers a sub n okay and what's cool + + align:start position:0% +numbers a sub n okay and what's cool + + + align:start position:0% +numbers a sub n okay and what's cool +about this is that for some functions Y + + align:start position:0% +about this is that for some functions Y + + + align:start position:0% +about this is that for some functions Y +you can describe that function with just + + align:start position:0% +you can describe that function with just + + + align:start position:0% +you can describe that function with just +a few few of these coefficients a okay + + align:start position:0% +a few few of these coefficients a okay + + + align:start position:0% +a few few of these coefficients a okay +does that make sense so let me just show + + align:start position:0% +does that make sense so let me just show + + + align:start position:0% +does that make sense so let me just show +you an example of some functions that + + align:start position:0% +you an example of some functions that + + + align:start position:0% +you an example of some functions that +look really really simple when you + + align:start position:0% +look really really simple when you + + + align:start position:0% +look really really simple when you +rewrite them using these coefficients a + + align:start position:0% +rewrite them using these coefficients a + + + align:start position:0% +rewrite them using these coefficients a +okay so here's here's an example so + + align:start position:0% +okay so here's here's an example so + + + align:start position:0% +okay so here's here's an example so +here's a function of n that has three + + align:start position:0% +here's a function of n that has three + + + align:start position:0% +here's a function of n that has three +numbers a sub minus 1 N equals minus 1 + + align:start position:0% +numbers a sub minus 1 N equals minus 1 + + + align:start position:0% +numbers a sub minus 1 N equals minus 1 +is 1/2 a sub 0 and a sub 1 is 1/2 and + + align:start position:0% +is 1/2 a sub 0 and a sub 1 is 1/2 and + + + align:start position:0% +is 1/2 a sub 0 and a sub 1 is 1/2 and +all the rest of them are zeros so really + + align:start position:0% +all the rest of them are zeros so really + + + align:start position:0% +all the rest of them are zeros so really +we only have two nonzero entries in this + + align:start position:0% +we only have two nonzero entries in this + + + align:start position:0% +we only have two nonzero entries in this +sum so what what function is that it's + + align:start position:0% +sum so what what function is that it's + + + align:start position:0% +sum so what what function is that it's +just a cosine right so right we have + + align:start position:0% +just a cosine right so right we have + + + align:start position:0% +just a cosine right so right we have +let's write this out y equals a sum over + + align:start position:0% +let's write this out y equals a sum over + + + align:start position:0% +let's write this out y equals a sum over +all of these things 1/2 e to the might + + align:start position:0% +all of these things 1/2 e to the might + + + align:start position:0% +all of these things 1/2 e to the might +the first n is minus 1 e to the minus I + + align:start position:0% +the first n is minus 1 e to the minus I + + + align:start position:0% +the first n is minus 1 e to the minus I +Omega naught E + + align:start position:0% +Omega naught E + + + align:start position:0% +Omega naught E +plus 1/2 e to the plus I Omega naught T + + align:start position:0% +plus 1/2 e to the plus I Omega naught T + + + align:start position:0% +plus 1/2 e to the plus I Omega naught T +right we're just writing out that sum + + align:start position:0% +right we're just writing out that sum + + + align:start position:0% +right we're just writing out that sum +and that is just just use sorry I didn't + + align:start position:0% +and that is just just use sorry I didn't + + + align:start position:0% +and that is just just use sorry I didn't +tell you what that that equation was + + align:start position:0% +tell you what that that equation was + + + align:start position:0% +tell you what that that equation was +that's Euler's Euler's equation all + + align:start position:0% +that's Euler's Euler's equation all + + + align:start position:0% +that's Euler's Euler's equation all +right that's just cosine minus I sine + + align:start position:0% +right that's just cosine minus I sine + + + align:start position:0% +right that's just cosine minus I sine +Omega T that is just cosine plus I sine + + align:start position:0% +Omega T that is just cosine plus I sine + + + align:start position:0% +Omega T that is just cosine plus I sine +Omega T the sines cancel right and + + align:start position:0% +Omega T the sines cancel right and + + + align:start position:0% +Omega T the sines cancel right and +you're left with cosine T all right so + + align:start position:0% +you're left with cosine T all right so + + + align:start position:0% +you're left with cosine T all right so +here's this function of time that goes + + align:start position:0% +here's this function of time that goes + + + align:start position:0% +here's this function of time that goes +on infinitely if you wanted to write + + align:start position:0% +on infinitely if you wanted to write + + + align:start position:0% +on infinitely if you wanted to write +down all the values of cosine Omega + + align:start position:0% +down all the values of cosine Omega + + + align:start position:0% +down all the values of cosine Omega +naught T you'd have to write down an + + align:start position:0% +naught T you'd have to write down an + + + align:start position:0% +naught T you'd have to write down an +awful lot of numbers and here we can + + align:start position:0% +awful lot of numbers and here we can + + + align:start position:0% +awful lot of numbers and here we can +write down that same function with two + + align:start position:0% +write down that same function with two + + + align:start position:0% +write down that same function with two +numbers right so this is a very compact + + align:start position:0% +numbers right so this is a very compact + + + align:start position:0% +numbers right so this is a very compact +view of that function of time right okay + + align:start position:0% +view of that function of time right okay + + + align:start position:0% +view of that function of time right okay +here's another function what function do + + align:start position:0% +here's another function what function do + + + align:start position:0% +here's another function what function do +you think that is in time what would be + + align:start position:0% +you think that is in time what would be + + + align:start position:0% +you think that is in time what would be +the time domain equivalent of this set + + align:start position:0% +the time domain equivalent of this set + + + align:start position:0% +the time domain equivalent of this set +of Fourier coefficients good so we're + + align:start position:0% +of Fourier coefficients good so we're + + + align:start position:0% +of Fourier coefficients good so we're +gonna do the same thing just write it + + align:start position:0% +gonna do the same thing just write it + + + align:start position:0% +gonna do the same thing just write it +out all these sums are zero all these + + align:start position:0% +out all these sums are zero all these + + + align:start position:0% +out all these sums are zero all these +components are zero except for two of + + align:start position:0% +components are zero except for two of + + + align:start position:0% +components are zero except for two of +them N equals -2 and N equals plus two + + align:start position:0% +them N equals -2 and N equals plus two + + + align:start position:0% +them N equals -2 and N equals plus two +if you just put those in there as 1/2 e + + align:start position:0% +if you just put those in there as 1/2 e + + + align:start position:0% +if you just put those in there as 1/2 e +to the minus 2 Omega naught T plus 1/2 e + + align:start position:0% +to the minus 2 Omega naught T plus 1/2 e + + + align:start position:0% +to the minus 2 Omega naught T plus 1/2 e +to the plus 2 Omega and that is just if + + align:start position:0% +to the plus 2 Omega and that is just if + + + align:start position:0% +to the plus 2 Omega and that is just if +you write that out those signs cancel + + align:start position:0% +you write that out those signs cancel + + + align:start position:0% +you write that out those signs cancel +and you have cosine 2 Omega naught T ok + + align:start position:0% +and you have cosine 2 Omega naught T ok + + + align:start position:0% +and you have cosine 2 Omega naught T ok +pretty simple right ok how about this + + align:start position:0% +pretty simple right ok how about this + + + align:start position:0% +pretty simple right ok how about this +one this is the remember the A's are + + align:start position:0% +one this is the remember the A's are + + + align:start position:0% +one this is the remember the A's are +complex numbers the ones we were looking + + align:start position:0% +complex numbers the ones we were looking + + + align:start position:0% +complex numbers the ones we were looking +at here had two real numbers here's an + + align:start position:0% +at here had two real numbers here's an + + + align:start position:0% +at here had two real numbers here's an +example where the A's + + align:start position:0% +example where the A's + + + align:start position:0% +example where the A's +our our imaginary one is I over to one + + align:start position:0% +our our imaginary one is I over to one + + + align:start position:0% +our our imaginary one is I over to one +is minus I over to that's what the the + + align:start position:0% +is minus I over to that's what the the + + + align:start position:0% +is minus I over to that's what the the +complex Fourier representation looks + + align:start position:0% +complex Fourier representation looks + + + align:start position:0% +complex Fourier representation looks +like of this function we can just put in + + align:start position:0% +like of this function we can just put in + + + align:start position:0% +like of this function we can just put in +here + + align:start position:0% +here + + + align:start position:0% +here +you solve that you can see that the in + + align:start position:0% +you solve that you can see that the in + + + align:start position:0% +you solve that you can see that the in +this case the cosines cancel because + + align:start position:0% +this case the cosines cancel because + + + align:start position:0% +this case the cosines cancel because +this is I over 2 cosine 2 Omega t minus + + align:start position:0% +this is I over 2 cosine 2 Omega t minus + + + align:start position:0% +this is I over 2 cosine 2 Omega t minus +I over 2 cosine 2 Omega T those cancel + + align:start position:0% +I over 2 cosine 2 Omega T those cancel + + + align:start position:0% +I over 2 cosine 2 Omega T those cancel +and you're left with sine 2 Omega naught + + align:start position:0% +and you're left with sine 2 Omega naught + + + align:start position:0% +and you're left with sine 2 Omega naught +T okay so that is what we're a + + align:start position:0% +T okay so that is what we're a + + + align:start position:0% +T okay so that is what we're a +representation of sine 2 Omega T looks + + align:start position:0% +representation of sine 2 Omega T looks + + + align:start position:0% +representation of sine 2 Omega T looks +like ok so functions that have higher + + align:start position:0% +like ok so functions that have higher + + + align:start position:0% +like ok so functions that have higher +frequencies will have nonzero elements + + align:start position:0% +frequencies will have nonzero elements + + + align:start position:0% +frequencies will have nonzero elements +that are further out in n right ok any + + align:start position:0% +that are further out in n right ok any + + + align:start position:0% +that are further out in n right ok any +questions about that + + align:start position:0% + + + + align:start position:0% + +ok + + align:start position:0% +ok + + + align:start position:0% +ok +so again this set of functions e to the + + align:start position:0% +so again this set of functions e to the + + + align:start position:0% +so again this set of functions e to the +I n Omega naught T for man or that or + + align:start position:0% +I n Omega naught T for man or that or + + + align:start position:0% +I n Omega naught T for man or that or +thoug g''l orthonormal basis set over + + align:start position:0% +thoug g''l orthonormal basis set over + + + align:start position:0% +thoug g''l orthonormal basis set over +that of one's over that interval that a + + align:start position:0% +that of one's over that interval that a + + + align:start position:0% +that of one's over that interval that a +naught coefficient is just the + + align:start position:0% +naught coefficient is just the + + + align:start position:0% +naught coefficient is just the +projection of our function on to e to + + align:start position:0% +projection of our function on to e to + + + align:start position:0% +projection of our function on to e to +the 0 n equals 0 and that's just the + + align:start position:0% +the 0 n equals 0 and that's just the + + + align:start position:0% +the 0 n equals 0 and that's just the +average okay the a 1 coefficient is just + + align:start position:0% +average okay the a 1 coefficient is just + + + align:start position:0% +average okay the a 1 coefficient is just +the projection of our function e to the + + align:start position:0% +the projection of our function e to the + + + align:start position:0% +the projection of our function e to the +minus I Omega naught T and in general + + align:start position:0% +minus I Omega naught T and in general + + + align:start position:0% +minus I Omega naught T and in general +the M coefficient is just the projection + + align:start position:0% +the M coefficient is just the projection + + + align:start position:0% +the M coefficient is just the projection +of our function onto e to the minus I M + + align:start position:0% +of our function onto e to the minus I M + + + align:start position:0% +of our function onto e to the minus I M +Omega naught T ok and we can take those + + align:start position:0% +Omega naught T ok and we can take those + + + align:start position:0% +Omega naught T ok and we can take those +coefficients plug them into this sum and + + align:start position:0% +coefficients plug them into this sum and + + + align:start position:0% +coefficients plug them into this sum and +reconstruct an arbitrary periodic + + align:start position:0% +reconstruct an arbitrary periodic + + + align:start position:0% +reconstruct an arbitrary periodic +function this y of T ok so we have a way + + align:start position:0% +function this y of T ok so we have a way + + + align:start position:0% +function this y of T ok so we have a way +of taking a function and getting these + + align:start position:0% +of taking a function and getting these + + + align:start position:0% +of taking a function and getting these +complex Fourier coefficients and we have + + align:start position:0% +complex Fourier coefficients and we have + + + align:start position:0% +complex Fourier coefficients and we have +a way of taking those coefficients and + + align:start position:0% +a way of taking those coefficients and + + + align:start position:0% +a way of taking those coefficients and +reconstructing our function this is just + + align:start position:0% +reconstructing our function this is just + + + align:start position:0% +reconstructing our function this is just +a bunch of different views function Y + + align:start position:0% +a bunch of different views function Y + + + align:start position:0% +a bunch of different views function Y +and from all of those different views we + + align:start position:0% +and from all of those different views we + + + align:start position:0% +and from all of those different views we +can reconstruct our function and that's + + align:start position:0% +can reconstruct our function and that's + + + align:start position:0% +can reconstruct our function and that's +all it is + + align:start position:0% +all it is + + + align:start position:0% +all it is +so in general when we do Fourier + + align:start position:0% +so in general when we do Fourier + + + align:start position:0% +so in general when we do Fourier +decomposition in a computer in MATLAB on + + align:start position:0% +decomposition in a computer in MATLAB on + + + align:start position:0% +decomposition in a computer in MATLAB on +real signals that you've sampled in time + + align:start position:0% +real signals that you've sampled in time + + + align:start position:0% +real signals that you've sampled in time +it's always done in this kind of + + align:start position:0% +it's always done in this kind of + + + align:start position:0% +it's always done in this kind of +discrete representation you've got in + + align:start position:0% +discrete representation you've got in + + + align:start position:0% +discrete representation you've got in +this case discrete frequencies when you + + align:start position:0% +this case discrete frequencies when you + + + align:start position:0% +this case discrete frequencies when you +sample signals you've got functions that + + align:start position:0% +sample signals you've got functions that + + + align:start position:0% +sample signals you've got functions that +are discrete in time and this becomes a + + align:start position:0% +are discrete in time and this becomes a + + + align:start position:0% +are discrete in time and this becomes a +sum ok but before we go to the discrete + + align:start position:0% +sum ok but before we go to the discrete + + + align:start position:0% +sum ok but before we go to the discrete +case I just want to show you what this + + align:start position:0% +case I just want to show you what this + + + align:start position:0% +case I just want to show you what this +looks like when we go to the the case of + + align:start position:0% +looks like when we go to the the case of + + + align:start position:0% +looks like when we go to the the case of +arbitrary function + + align:start position:0% +arbitrary function + + + align:start position:0% +arbitrary function +this thing was about representing + + align:start position:0% +this thing was about representing + + + align:start position:0% +this thing was about representing +periodic functions you can only + + align:start position:0% +periodic functions you can only + + + align:start position:0% +periodic functions you can only +represent periodic functions using this + + align:start position:0% +represent periodic functions using this + + + align:start position:0% +represent periodic functions using this +these Fourier series okay but before we + + align:start position:0% +these Fourier series okay but before we + + + align:start position:0% +these Fourier series okay but before we +go on to the Fourier transform algorithm + + align:start position:0% +go on to the Fourier transform algorithm + + + align:start position:0% +go on to the Fourier transform algorithm +and discrete Fourier transforms I just + + align:start position:0% +and discrete Fourier transforms I just + + + align:start position:0% +and discrete Fourier transforms I just +want to show you what this looks like + + align:start position:0% +want to show you what this looks like + + + align:start position:0% +want to show you what this looks like +for the case of arbitrary functions okay + + align:start position:0% +for the case of arbitrary functions okay + + + align:start position:0% +for the case of arbitrary functions okay +and it's just I'm just showing this to + + align:start position:0% +and it's just I'm just showing this to + + + align:start position:0% +and it's just I'm just showing this to +you I don't expect you to be able to + + align:start position:0% +you I don't expect you to be able to + + + align:start position:0% +you I don't expect you to be able to +reproduce any of this but you should see + + align:start position:0% +reproduce any of this but you should see + + + align:start position:0% +reproduce any of this but you should see +what it looks like okay for those of you + + align:start position:0% +what it looks like okay for those of you + + + align:start position:0% +what it looks like okay for those of you +who haven't seen it already okay so what + + align:start position:0% +who haven't seen it already okay so what + + + align:start position:0% +who haven't seen it already okay so what +we're gonna do is go from the case of + + align:start position:0% +we're gonna do is go from the case of + + + align:start position:0% +we're gonna do is go from the case of +periodic functions to non periodic + + align:start position:0% +periodic functions to non periodic + + + align:start position:0% +periodic functions to non periodic +functions and the simplest way to think + + align:start position:0% +functions and the simplest way to think + + + align:start position:0% +functions and the simplest way to think +about that is a periodic function does + + align:start position:0% +about that is a periodic function does + + + align:start position:0% +about that is a periodic function does +something here and then it just does the + + align:start position:0% +something here and then it just does the + + + align:start position:0% +something here and then it just does the +same thing here and then it just does + + align:start position:0% +same thing here and then it just does + + + align:start position:0% +same thing here and then it just does +the same thing here right so how do we + + align:start position:0% +the same thing here right so how do we + + + align:start position:0% +the same thing here right so how do we +go from from this to an arbitrary + + align:start position:0% +go from from this to an arbitrary + + + align:start position:0% +go from from this to an arbitrary +function well we're just going to let + + align:start position:0% +function well we're just going to let + + + align:start position:0% +function well we're just going to let +the period go to infinity okay that + + align:start position:0% +the period go to infinity okay that + + + align:start position:0% +the period go to infinity okay that +makes sense okay but that's actually + + align:start position:0% +makes sense okay but that's actually + + + align:start position:0% +makes sense okay but that's actually +pretty easy we're gonna let t go to + + align:start position:0% +pretty easy we're gonna let t go to + + + align:start position:0% +pretty easy we're gonna let t go to +infinity which means the frequencies are + + align:start position:0% +infinity which means the frequencies are + + + align:start position:0% +infinity which means the frequencies are +two pi Omega naught R two PI over T + + align:start position:0% +two pi Omega naught R two PI over T + + + align:start position:0% +two pi Omega naught R two PI over T +that's going to go to zero right so our + + align:start position:0% +that's going to go to zero right so our + + + align:start position:0% +that's going to go to zero right so our +our steps remember when we had this + + align:start position:0% +our steps remember when we had this + + + align:start position:0% +our steps remember when we had this +discrete Fourier transform here we had + + align:start position:0% +discrete Fourier transform here we had + + + align:start position:0% +discrete Fourier transform here we had +these steps in frequency as a function + + align:start position:0% +these steps in frequency as a function + + + align:start position:0% +these steps in frequency as a function +of N those steps are just going to get + + align:start position:0% +of N those steps are just going to get + + + align:start position:0% +of N those steps are just going to get +infinitely close together the different + + align:start position:0% +infinitely close together the different + + + align:start position:0% +infinitely close together the different +frequency bins okay so that's what we're + + align:start position:0% +frequency bins okay so that's what we're + + + align:start position:0% +frequency bins okay so that's what we're +gonna do now you're going to let those + + align:start position:0% +gonna do now you're going to let those + + + align:start position:0% +gonna do now you're going to let those +frequency steps go to zero and now + + align:start position:0% +frequency steps go to zero and now + + + align:start position:0% +frequency steps go to zero and now +frequency in discrete case the frequency + + align:start position:0% +frequency in discrete case the frequency + + + align:start position:0% +frequency in discrete case the frequency +is just that number that n times Omega + + align:start position:0% +is just that number that n times Omega + + + align:start position:0% +is just that number that n times Omega +naught M times Omega naught well Omega + + align:start position:0% +naught M times Omega naught well Omega + + + align:start position:0% +naught M times Omega naught well Omega +naught is going to 0 but the MS are + + align:start position:0% +naught is going to 0 but the MS are + + + align:start position:0% +naught is going to 0 but the MS are +getting really big so we can just change + + align:start position:0% +getting really big so we can just change + + + align:start position:0% +getting really big so we can just change +we're just going to call that Omega okay + + align:start position:0% +we're just going to call that Omega okay + + + align:start position:0% +we're just going to call that Omega okay +letting you know the Omega nuts are + + align:start position:0% +letting you know the Omega nuts are + + + align:start position:0% +letting you know the Omega nuts are +going to 0 so the MS are getting + + align:start position:0% +going to 0 so the MS are getting + + + align:start position:0% +going to 0 so the MS are getting +infinitely big so we can't really use em + + align:start position:0% +infinitely big so we can't really use em + + + align:start position:0% +infinitely big so we can't really use em +anymore or n to label our frequency + + align:start position:0% +anymore or n to label our frequency + + + align:start position:0% +anymore or n to label our frequency +steps so we're just gonna use Omega okay + + align:start position:0% +steps so we're just gonna use Omega okay + + + align:start position:0% +steps so we're just gonna use Omega okay +we used to call our coefficients our + + align:start position:0% +we used to call our coefficients our + + + align:start position:0% +we used to call our coefficients our +Fourier coefficients we used to label + + align:start position:0% +Fourier coefficients we used to label + + + align:start position:0% +Fourier coefficients we used to label +them with em we can't use em anymore + + align:start position:0% +them with em we can't use em anymore + + + align:start position:0% +them with em we can't use em anymore +because M is getting infinitely big so + + align:start position:0% +because M is getting infinitely big so + + + align:start position:0% +because M is getting infinitely big so +we use it we use this new label Omega so + + align:start position:0% +we use it we use this new label Omega so + + + align:start position:0% +we use it we use this new label Omega so +a sub M becomes a new variable our + + align:start position:0% +a sub M becomes a new variable our + + + align:start position:0% +a sub M becomes a new variable our +Fourier transform labeled by the + + align:start position:0% +Fourier transform labeled by the + + + align:start position:0% +Fourier transform labeled by the +frequency Omega okay and we're just + + align:start position:0% +frequency Omega okay and we're just + + + align:start position:0% +frequency Omega okay and we're just +going to basically just make those + + align:start position:0% +going to basically just make those + + + align:start position:0% +going to basically just make those +replacements in here so the coefficients + + align:start position:0% +replacements in here so the coefficients + + + align:start position:0% +replacements in here so the coefficients +become a function of frequency that's + + align:start position:0% +become a function of frequency that's + + + align:start position:0% +become a function of frequency that's +just an integral remember T is going to + + align:start position:0% +just an integral remember T is going to + + + align:start position:0% +just an integral remember T is going to +infinity now so this has to go from + + align:start position:0% +infinity now so this has to go from + + + align:start position:0% +infinity now so this has to go from +minus infinity to infinity of our + + align:start position:0% +minus infinity to infinity of our + + + align:start position:0% +minus infinity to infinity of our +function y times our basis function and + + align:start position:0% +function y times our basis function and + + + align:start position:0% +function y times our basis function and +instead of e to the I M Omega naught T + + align:start position:0% +instead of e to the I M Omega naught T + + + align:start position:0% +instead of e to the I M Omega naught T +we just replaced mo mega not with Omega + + align:start position:0% +we just replaced mo mega not with Omega + + + align:start position:0% +we just replaced mo mega not with Omega +so e to the minus I Omega T okay and + + align:start position:0% +so e to the minus I Omega T okay and + + + align:start position:0% +so e to the minus I Omega T okay and +that is the Fourier transform okay and + + align:start position:0% +that is the Fourier transform okay and + + + align:start position:0% +that is the Fourier transform okay and +we're just going to do the same + + align:start position:0% +we're just going to do the same + + + align:start position:0% +we're just going to do the same +replacement here + + align:start position:0% +replacement here + + + align:start position:0% +replacement here +but we're instead of summing over n + + align:start position:0% +but we're instead of summing over n + + + align:start position:0% +but we're instead of summing over n +going from minus infinity to infinity we + + align:start position:0% +going from minus infinity to infinity we + + + align:start position:0% +going from minus infinity to infinity we +have to write this as an integral as + + align:start position:0% +have to write this as an integral as + + + align:start position:0% +have to write this as an integral as +well and so that we can reconstruct our + + align:start position:0% +well and so that we can reconstruct our + + + align:start position:0% +well and so that we can reconstruct our +function y of T as an integral of our + + align:start position:0% +function y of T as an integral of our + + + align:start position:0% +function y of T as an integral of our +Fourier coefficients times the e to the + + align:start position:0% +Fourier coefficients times the e to the + + + align:start position:0% +Fourier coefficients times the e to the +I Omega T see that it's the same it's + + align:start position:0% +I Omega T see that it's the same it's + + + align:start position:0% +I Omega T see that it's the same it's +essentially the same thing it's just + + align:start position:0% +essentially the same thing it's just + + + align:start position:0% +essentially the same thing it's just +that we're turning this sum into an + + align:start position:0% +that we're turning this sum into an + + + align:start position:0% +that we're turning this sum into an +integral okay all right so that's called + + align:start position:0% +integral okay all right so that's called + + + align:start position:0% +integral okay all right so that's called +a Fourier transform and that's the + + align:start position:0% +a Fourier transform and that's the + + + align:start position:0% +a Fourier transform and that's the +inverse Fourier transform this from a + + align:start position:0% +inverse Fourier transform this from a + + + align:start position:0% +inverse Fourier transform this from a +function to Fourier coefficients and + + align:start position:0% +function to Fourier coefficients and + + + align:start position:0% +function to Fourier coefficients and +this takes your Fourier coefficients and + + align:start position:0% +this takes your Fourier coefficients and + + + align:start position:0% +this takes your Fourier coefficients and +goes back to your function okay all + + align:start position:0% +goes back to your function okay all + + + align:start position:0% +goes back to your function okay all +right good let me just show you a few + + align:start position:0% +right good let me just show you a few + + + align:start position:0% +right good let me just show you a few +simple examples so let's start let's + + align:start position:0% +simple examples so let's start let's + + + align:start position:0% +simple examples so let's start let's +have a start with a function y of T + + align:start position:0% +have a start with a function y of T + + + align:start position:0% +have a start with a function y of T +equals 1 so it's just a constant what is + + align:start position:0% +equals 1 so it's just a constant what is + + + align:start position:0% +equals 1 so it's just a constant what is +the Fourier transform so let's plug this + + align:start position:0% +the Fourier transform so let's plug this + + + align:start position:0% +the Fourier transform so let's plug this +into here + + align:start position:0% +into here + + + align:start position:0% +into here +okay does anyone know what that integral + + align:start position:0% +okay does anyone know what that integral + + + align:start position:0% +okay does anyone know what that integral +looks like of the integral from minus + + align:start position:0% +looks like of the integral from minus + + + align:start position:0% +looks like of the integral from minus +infinity to infinity of e the minus I + + align:start position:0% +infinity to infinity of e the minus I + + + align:start position:0% +infinity to infinity of e the minus I +Omega T DT integrating over time it's a + + align:start position:0% +Omega T DT integrating over time it's a + + + align:start position:0% +Omega T DT integrating over time it's a +delta function there's only one value of + + align:start position:0% +delta function there's only one value of + + + align:start position:0% +delta function there's only one value of +Omega for which that function is not + + align:start position:0% +Omega for which that function is not + + + align:start position:0% +Omega for which that function is not +zero remember so let's say Omega equals + + align:start position:0% +zero remember so let's say Omega equals + + + align:start position:0% +zero remember so let's say Omega equals +one one you know one Hertz this is just + + align:start position:0% +one one you know one Hertz this is just + + + align:start position:0% +one one you know one Hertz this is just +a bunch of sines and cosines so when you + + align:start position:0% +a bunch of sines and cosines so when you + + + align:start position:0% +a bunch of sines and cosines so when you +integrate over sines and cosines you get + + align:start position:0% +integrate over sines and cosines you get + + + align:start position:0% +integrate over sines and cosines you get +zero integral over time of cosine is + + align:start position:0% +zero integral over time of cosine is + + + align:start position:0% +zero integral over time of cosine is +just zero + + align:start position:0% +just zero + + + align:start position:0% +just zero +but if Omega is zero then what is e to + + align:start position:0% +but if Omega is zero then what is e to + + + align:start position:0% +but if Omega is zero then what is e to +the I Omega T e to the I 0 is 1 and so + + align:start position:0% +the I Omega T e to the I 0 is 1 and so + + + align:start position:0% +the I Omega T e to the I 0 is 1 and so +we're integrating over 1 times DT right + + align:start position:0% +we're integrating over 1 times DT right + + + align:start position:0% +we're integrating over 1 times DT right +and that becomes infinity at Omega + + align:start position:0% +and that becomes infinity at Omega + + + align:start position:0% +and that becomes infinity at Omega +equals zero and that's a delta function + + align:start position:0% +equals zero and that's a delta function + + + align:start position:0% +equals zero and that's a delta function +it's zero everywhere except for at zero + + align:start position:0% +it's zero everywhere except for at zero + + + align:start position:0% +it's zero everywhere except for at zero +so that becomes a delta function this + + align:start position:0% +so that becomes a delta function this + + + align:start position:0% +so that becomes a delta function this +Fourier transform of a constant is a + + align:start position:0% +Fourier transform of a constant is a + + + align:start position:0% +Fourier transform of a constant is a +delta function okay and that's a really + + align:start position:0% +delta function okay and that's a really + + + align:start position:0% +delta function okay and that's a really +it's a really good one to know before + + align:start position:0% +it's a really good one to know before + + + align:start position:0% +it's a really good one to know before +you transform of a constant is a delta + + align:start position:0% +you transform of a constant is a delta + + + align:start position:0% +you transform of a constant is a delta +function okay that's called a Fourier + + align:start position:0% +function okay that's called a Fourier + + + align:start position:0% +function okay that's called a Fourier +transform pair you have a function and + + align:start position:0% +transform pair you have a function and + + + align:start position:0% +transform pair you have a function and +another function one function is the + + align:start position:0% +another function one function is the + + + align:start position:0% +another function one function is the +Fourier transform of the other function + + align:start position:0% +Fourier transform of the other function + + + align:start position:0% +Fourier transform of the other function +that's called a Fourier transform pair + + align:start position:0% +that's called a Fourier transform pair + + + align:start position:0% +that's called a Fourier transform pair +okay so the Fourier transform of a + + align:start position:0% +okay so the Fourier transform of a + + + align:start position:0% +okay so the Fourier transform of a +constant is just a delta function at 0 + + align:start position:0% +constant is just a delta function at 0 + + + align:start position:0% +constant is just a delta function at 0 +you can invert that if you integrate + + align:start position:0% +you can invert that if you integrate + + + align:start position:0% +you can invert that if you integrate +let's just plug that Delta function into + + align:start position:0% +let's just plug that Delta function into + + + align:start position:0% +let's just plug that Delta function into +here if you integrate Delta function + + align:start position:0% +here if you integrate Delta function + + + align:start position:0% +here if you integrate Delta function +times e to the I Omega T you just get e + + align:start position:0% +times e to the I Omega T you just get e + + + align:start position:0% +times e to the I Omega T you just get e +to the I 0 T which is just 1 ok + + align:start position:0% +to the I 0 T which is just 1 ok + + + align:start position:0% +to the I 0 T which is just 1 ok +so we can take the Fourier transform of + + align:start position:0% +so we can take the Fourier transform of + + + align:start position:0% +so we can take the Fourier transform of +one get a delta function interest for + + align:start position:0% +one get a delta function interest for + + + align:start position:0% +one get a delta function interest for +you transform the Delta function and get + + align:start position:0% +you transform the Delta function and get + + + align:start position:0% +you transform the Delta function and get +back one okay all right + + align:start position:0% +back one okay all right + + + align:start position:0% +back one okay all right +how about this function right here this + + align:start position:0% +how about this function right here this + + + align:start position:0% +how about this function right here this +function is e to the I Omega 1 it's it's + + align:start position:0% +function is e to the I Omega 1 it's it's + + + align:start position:0% +function is e to the I Omega 1 it's it's +a sine wave and a cosine wave a complex + + align:start position:0% +a sine wave and a cosine wave a complex + + + align:start position:0% +a sine wave and a cosine wave a complex +sine and cosine at frequency Omega 1 + + align:start position:0% +sine and cosine at frequency Omega 1 + + + align:start position:0% +sine and cosine at frequency Omega 1 +anybody know what the for you so it's + + align:start position:0% +anybody know what the for you so it's + + + align:start position:0% +anybody know what the for you so it's +it's basically you can think of this + + align:start position:0% +it's basically you can think of this + + + align:start position:0% +it's basically you can think of this +okay yeah that's all right answer rather + + align:start position:0% +okay yeah that's all right answer rather + + + align:start position:0% +okay yeah that's all right answer rather +than try to explain it I'll just show + + align:start position:0% +than try to explain it I'll just show + + + align:start position:0% +than try to explain it I'll just show +you so the Fourier transform of this is + + align:start position:0% +you so the Fourier transform of this is + + + align:start position:0% +you so the Fourier transform of this is +to peak at Omega 1 alright and we can + + align:start position:0% +to peak at Omega 1 alright and we can + + + align:start position:0% +to peak at Omega 1 alright and we can +inverse Fourier transform that and + + align:start position:0% +inverse Fourier transform that and + + + align:start position:0% +inverse Fourier transform that and +recover our original function ok so + + align:start position:0% +recover our original function ok so + + + align:start position:0% +recover our original function ok so +those that's those last few slides are + + align:start position:0% +those that's those last few slides are + + + align:start position:0% +those that's those last few slides are +more for the aficionados you don't have + + align:start position:0% +more for the aficionados you don't have + + + align:start position:0% +more for the aficionados you don't have +to know that we're gonna spend time + + align:start position:0% +to know that we're gonna spend time + + + align:start position:0% +to know that we're gonna spend time +looking at the at the discrete versions + + align:start position:0% +looking at the at the discrete versions + + + align:start position:0% +looking at the at the discrete versions +of these things okay all right how about + + align:start position:0% +of these things okay all right how about + + + align:start position:0% +of these things okay all right how about +this case this is a simple case where + + align:start position:0% +this case this is a simple case where + + + align:start position:0% +this case this is a simple case where +you have a function that the Fourier + + align:start position:0% +you have a function that the Fourier + + + align:start position:0% +you have a function that the Fourier +transform of which has a peak at Omega 1 + + align:start position:0% +transform of which has a peak at Omega 1 + + + align:start position:0% +transform of which has a peak at Omega 1 +and a peak at minus Omega 1 the Fourier + + align:start position:0% +and a peak at minus Omega 1 the Fourier + + + align:start position:0% +and a peak at minus Omega 1 the Fourier +transform of the inverse Fourier + + align:start position:0% +transform of the inverse Fourier + + + align:start position:0% +transform of the inverse Fourier +transform of that is just cosine Omega + + align:start position:0% +transform of that is just cosine Omega + + + align:start position:0% +transform of that is just cosine Omega +1t ok so a function a cosine function + + align:start position:0% +1t ok so a function a cosine function + + + align:start position:0% +1t ok so a function a cosine function +with frequency Omega 1 has two peaks one + + align:start position:0% +with frequency Omega 1 has two peaks one + + + align:start position:0% +with frequency Omega 1 has two peaks one +at frequency Omega 1 and another one at + + align:start position:0% +at frequency Omega 1 and another one at + + + align:start position:0% +at frequency Omega 1 and another one at +frequency minus Omega 1 so that looks a + + align:start position:0% +frequency minus Omega 1 so that looks a + + + align:start position:0% +frequency minus Omega 1 so that looks a +lot like the case we just talked about + + align:start position:0% +lot like the case we just talked about + + + align:start position:0% +lot like the case we just talked about +right where we had this complex Fourier + + align:start position:0% +right where we had this complex Fourier + + + align:start position:0% +right where we had this complex Fourier +series and we had a peak at N equals 2 + + align:start position:0% +series and we had a peak at N equals 2 + + + align:start position:0% +series and we had a peak at N equals 2 +and another peak at N equals -2 and the + + align:start position:0% +and another peak at N equals -2 and the + + + align:start position:0% +and another peak at N equals -2 and the +function that gave us that complex + + align:start position:0% +function that gave us that complex + + + align:start position:0% +function that gave us that complex +Fourier series was cosine 2t so that's + + align:start position:0% +Fourier series was cosine 2t so that's + + + align:start position:0% +Fourier series was cosine 2t so that's +just what we have here we have a peak in + + align:start position:0% +just what we have here we have a peak in + + + align:start position:0% +just what we have here we have a peak in +the spectrum at Omega 1 peak at minus + + align:start position:0% +the spectrum at Omega 1 peak at minus + + + align:start position:0% +the spectrum at Omega 1 peak at minus +Omega 1 and that is the Fourier + + align:start position:0% +Omega 1 and that is the Fourier + + + align:start position:0% +Omega 1 and that is the Fourier +decomposition of a function that is + + align:start position:0% +decomposition of a function that is + + + align:start position:0% +decomposition of a function that is +cosine Omega 1t + + align:start position:0% +cosine Omega 1t + + + align:start position:0% +cosine Omega 1t +so it's just like what we saw before for + + align:start position:0% +so it's just like what we saw before for + + + align:start position:0% +so it's just like what we saw before for +the case of the Fourier the complex + + align:start position:0% +the case of the Fourier the complex + + + align:start position:0% +the case of the Fourier the complex +Fourier series alright so that was + + align:start position:0% +Fourier series alright so that was + + + align:start position:0% +Fourier series alright so that was +Fourier transform and now let's talk + + align:start position:0% +Fourier transform and now let's talk + + + align:start position:0% +Fourier transform and now let's talk +about the discrete Fourier transform and + + align:start position:0% +about the discrete Fourier transform and + + + align:start position:0% +about the discrete Fourier transform and +the associated algorithm for computing + + align:start position:0% +the associated algorithm for computing + + + align:start position:0% +the associated algorithm for computing +that very quickly called a fast Fourier + + align:start position:0% +that very quickly called a fast Fourier + + + align:start position:0% +that very quickly called a fast Fourier +transform or FFT okay so you can see + + align:start position:0% +transform or FFT okay so you can see + + + align:start position:0% +transform or FFT okay so you can see +computing these Fourier transforms if + + align:start position:0% +computing these Fourier transforms if + + + align:start position:0% +computing these Fourier transforms if +you were to actually try to compute + + align:start position:0% +you were to actually try to compute + + + align:start position:0% +you were to actually try to compute +Fourier transforms by taking a function + + align:start position:0% +Fourier transforms by taking a function + + + align:start position:0% +Fourier transforms by taking a function +multiplying it by these complex + + align:start position:0% +multiplying it by these complex + + + align:start position:0% +multiplying it by these complex +Exponential's like writing down the + + align:start position:0% +Exponential's like writing down the + + + align:start position:0% +Exponential's like writing down the +value of e to the I Omega T at a bunch + + align:start position:0% +value of e to the I Omega T at a bunch + + + align:start position:0% +value of e to the I Omega T at a bunch +of different omegas and a bunch of + + align:start position:0% +of different omegas and a bunch of + + + align:start position:0% +of different omegas and a bunch of +different ways and then integrating that + + align:start position:0% +different ways and then integrating that + + + align:start position:0% +different ways and then integrating that +numerically that would take forever + + align:start position:0% +numerically that would take forever + + + align:start position:0% +numerically that would take forever +right computationally but it turns out + + align:start position:0% +right computationally but it turns out + + + align:start position:0% +right computationally but it turns out +that there's right so you have to + + align:start position:0% +that there's right so you have to + + + align:start position:0% +that there's right so you have to +compute that integral for it over time + + align:start position:0% +compute that integral for it over time + + + align:start position:0% +compute that integral for it over time +for every Omega that you're interested + + align:start position:0% +for every Omega that you're interested + + + align:start position:0% +for every Omega that you're interested +in all right + + align:start position:0% +in all right + + + align:start position:0% +in all right +but it turns out really really fast + + align:start position:0% +but it turns out really really fast + + + align:start position:0% +but it turns out really really fast +algorithm that you can use for the case + + align:start position:0% +algorithm that you can use for the case + + + align:start position:0% +algorithm that you can use for the case +where you've got functions that are + + align:start position:0% +where you've got functions that are + + + align:start position:0% +where you've got functions that are +sampled in time okay and you want to + + align:start position:0% +sampled in time okay and you want to + + + align:start position:0% +sampled in time okay and you want to +extract the frequencies of that signal + + align:start position:0% +extract the frequencies of that signal + + + align:start position:0% +extract the frequencies of that signal +at a discrete set of frequencies + + align:start position:0% +at a discrete set of frequencies + + + align:start position:0% +at a discrete set of frequencies +okay so let's I'm going to switch from + + align:start position:0% +okay so let's I'm going to switch from + + + align:start position:0% +okay so let's I'm going to switch from +using Omega which is very commonly used + + align:start position:0% +using Omega which is very commonly used + + + align:start position:0% +using Omega which is very commonly used +when you're talking about Fourier + + align:start position:0% +when you're talking about Fourier + + + align:start position:0% +when you're talking about Fourier +transforms to just using F the frequency + + align:start position:0% +transforms to just using F the frequency + + + align:start position:0% +transforms to just using F the frequency +so it's just F is just 2 pi so Omega is + + align:start position:0% +so it's just F is just 2 pi so Omega is + + + align:start position:0% +so it's just F is just 2 pi so Omega is +2 pi F so R here I'm just rewriting the + + align:start position:0% +2 pi F so R here I'm just rewriting the + + + align:start position:0% +2 pi F so R here I'm just rewriting the +Fourier transform and the inverse + + align:start position:0% +Fourier transform and the inverse + + + align:start position:0% +Fourier transform and the inverse +Fourier transform with F rather than + + align:start position:0% +Fourier transform with F rather than + + + align:start position:0% +Fourier transform with F rather than +Omega so we're gonna start using F's now + + align:start position:0% +Omega so we're gonna start using F's now + + + align:start position:0% +Omega so we're gonna start using F's now +for the discrete Fourier transform case + + align:start position:0% +for the discrete Fourier transform case + + + align:start position:0% +for the discrete Fourier transform case +and we're going to consider the case + + align:start position:0% +and we're going to consider the case + + + align:start position:0% +and we're going to consider the case +where we have signals that are sampled + + align:start position:0% +where we have signals that are sampled + + + align:start position:0% +where we have signals that are sampled +at regular intervals delta T ok so here + + align:start position:0% +at regular intervals delta T ok so here + + + align:start position:0% +at regular intervals delta T ok so here +we have a function of time Y of T and + + align:start position:0% +we have a function of time Y of T and + + + align:start position:0% +we have a function of time Y of T and +we're gonna sample that signal at + + align:start position:0% +we're gonna sample that signal at + + + align:start position:0% +we're gonna sample that signal at +regular intervals delta T so this is + + align:start position:0% +regular intervals delta T so this is + + + align:start position:0% +regular intervals delta T so this is +Delta t right + + align:start position:0% +Delta t right + + + align:start position:0% +Delta t right +that time interval there so the sampling + + align:start position:0% +that time interval there so the sampling + + + align:start position:0% +that time interval there so the sampling +rate the sampling frequency is just one + + align:start position:0% +rate the sampling frequency is just one + + + align:start position:0% +rate the sampling frequency is just one +over delta T so the way this works in + + align:start position:0% +over delta T so the way this works in + + + align:start position:0% +over delta T so the way this works in +the Fourier transform algorithm is you + + align:start position:0% +the Fourier transform algorithm is you + + + align:start position:0% +the Fourier transform algorithm is you +just take those samples and you into a + + align:start position:0% +just take those samples and you into a + + + align:start position:0% +just take those samples and you into a +vector in MATLAB okay just some one one + + align:start position:0% +vector in MATLAB okay just some one one + + + align:start position:0% +vector in MATLAB okay just some one one +dimensional array and we're going to + + align:start position:0% +dimensional array and we're going to + + + align:start position:0% +dimensional array and we're going to +imagine that our samples are acquired at + + align:start position:0% +imagine that our samples are acquired at + + + align:start position:0% +imagine that our samples are acquired at +different times and let's lay x minus x + + align:start position:0% +different times and let's lay x minus x + + + align:start position:0% +different times and let's lay x minus x +step eight - seven - six time step zero + + align:start position:0% +step eight - seven - six time step zero + + + align:start position:0% +step eight - seven - six time step zero +is in the middle up to time step seven + + align:start position:0% +is in the middle up to time step seven + + + align:start position:0% +is in the middle up to time step seven +and we're gonna say that n is an even + + align:start position:0% +and we're gonna say that n is an even + + + align:start position:0% +and we're gonna say that n is an even +number that the fast Fourier transform + + align:start position:0% +number that the fast Fourier transform + + + align:start position:0% +number that the fast Fourier transform +works much much faster when n is an even + + align:start position:0% +works much much faster when n is an even + + + align:start position:0% +works much much faster when n is an even +number and it works even faster when N + + align:start position:0% +number and it works even faster when N + + + align:start position:0% +number and it works even faster when N +is a multiple a power of two okay so in + + align:start position:0% +is a multiple a power of two okay so in + + + align:start position:0% +is a multiple a power of two okay so in +this case we have 16 samples it's two to + + align:start position:0% +this case we have 16 samples it's two to + + + align:start position:0% +this case we have 16 samples it's two to +the four should usually try to make your + + align:start position:0% +the four should usually try to make your + + + align:start position:0% +the four should usually try to make your +samples be a power of two okay the + + align:start position:0% +samples be a power of two okay the + + + align:start position:0% +samples be a power of two okay the +number of samples okay so there is our + + align:start position:0% +number of samples okay so there is our + + + align:start position:0% +number of samples okay so there is our +function of time sampled at regular + + align:start position:0% +function of time sampled at regular + + + align:start position:0% +function of time sampled at regular +intervals T so you can see that the team + + align:start position:0% +intervals T so you can see that the team + + + align:start position:0% +intervals T so you can see that the team +in the minimum time in this vector of + + align:start position:0% +in the minimum time in this vector of + + + align:start position:0% +in the minimum time in this vector of +sample points in our function is minus n + + align:start position:0% +sample points in our function is minus n + + + align:start position:0% +sample points in our function is minus n +over 2 delta T okay and that Matt is n + + align:start position:0% +over 2 delta T okay and that Matt is n + + + align:start position:0% +over 2 delta T okay and that Matt is n +over 2 minus 1 times delta T okay and + + align:start position:0% +over 2 minus 1 times delta T okay and + + + align:start position:0% +over 2 minus 1 times delta T okay and +that's what the the MATLAB code would + + align:start position:0% +that's what the the MATLAB code would + + + align:start position:0% +that's what the the MATLAB code would +look like to generate an array of time + + align:start position:0% +look like to generate an array of time + + + align:start position:0% +look like to generate an array of time +values okay + + align:start position:0% +values okay + + + align:start position:0% +values okay +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +all right the FFT algorithm returns the + + align:start position:0% +all right the FFT algorithm returns the + + + align:start position:0% +all right the FFT algorithm returns the +Fourier components of that function of + + align:start position:0% +Fourier components of that function of + + + align:start position:0% +Fourier components of that function of +time okay and it returns the Fourier + + align:start position:0% +time okay and it returns the Fourier + + + align:start position:0% +time okay and it returns the Fourier +components in a vector that has the + + align:start position:0% +components in a vector that has the + + + align:start position:0% +components in a vector that has the +negative frequencies on one side and the + + align:start position:0% +negative frequencies on one side and the + + + align:start position:0% +negative frequencies on one side and the +positive frequencies on the other side + + align:start position:0% +positive frequencies on the other side + + + align:start position:0% +positive frequencies on the other side +okay and the constant term here in the + + align:start position:0% +okay and the constant term here in the + + + align:start position:0% +okay and the constant term here in the +middle okay the minimum frequency is n + + align:start position:0% +middle okay the minimum frequency is n + + + align:start position:0% +middle okay the minimum frequency is n +over 2 times Delta F oh I should say it + + align:start position:0% +over 2 times Delta F oh I should say it + + + align:start position:0% +over 2 times Delta F oh I should say it +returns the Fourier components in steps + + align:start position:0% +returns the Fourier components in steps + + + align:start position:0% +returns the Fourier components in steps +of Delta F where Delta F is the sampling + + align:start position:0% +of Delta F where Delta F is the sampling + + + align:start position:0% +of Delta F where Delta F is the sampling +rate divided by the number of time steps + + align:start position:0% +rate divided by the number of time steps + + + align:start position:0% +rate divided by the number of time steps +that you put into it okay don't panic + + align:start position:0% +that you put into it okay don't panic + + + align:start position:0% +that you put into it okay don't panic +this is just like reference I'm showing + + align:start position:0% +this is just like reference I'm showing + + + align:start position:0% +this is just like reference I'm showing +you like what how you put the data in + + align:start position:0% +you like what how you put the data in + + + align:start position:0% +you like what how you put the data in +and how you get the data out okay when + + align:start position:0% +and how you get the data out okay when + + + align:start position:0% +and how you get the data out okay when +you put data into the Fourier transform + + align:start position:0% +you put data into the Fourier transform + + + align:start position:0% +you put data into the Fourier transform +algorithm the FFT algorithm you put in + + align:start position:0% +algorithm the FFT algorithm you put in + + + align:start position:0% +algorithm the FFT algorithm you put in +data that's sampled at times and you + + align:start position:0% +data that's sampled at times and you + + + align:start position:0% +data that's sampled at times and you +have to know what those times are right + + align:start position:0% +have to know what those times are right + + + align:start position:0% +have to know what those times are right +if you want to make a plot of the data + + align:start position:0% +if you want to make a plot of the data + + + align:start position:0% +if you want to make a plot of the data +eat to make an array of time values okay + + align:start position:0% +eat to make an array of time values okay + + + align:start position:0% +eat to make an array of time values okay +and they just go from a team into a t + + align:start position:0% +and they just go from a team into a t + + + align:start position:0% +and they just go from a team into a t +max all right and there's a little piece + + align:start position:0% +max all right and there's a little piece + + + align:start position:0% +max all right and there's a little piece +of MATLAB code that produces that array + + align:start position:0% +of MATLAB code that produces that array + + + align:start position:0% +of MATLAB code that produces that array +of times for you what you get back from + + align:start position:0% +of times for you what you get back from + + + align:start position:0% +of times for you what you get back from +the Fourier transform the FFT an array + + align:start position:0% +the Fourier transform the FFT an array + + + align:start position:0% +the Fourier transform the FFT an array +not of values of the function of time + + align:start position:0% +not of values of the function of time + + + align:start position:0% +not of values of the function of time +but rather an array of Fourier + + align:start position:0% +but rather an array of Fourier + + + align:start position:0% +but rather an array of Fourier +coefficients just like we stuck in into + + align:start position:0% +coefficients just like we stuck in into + + + align:start position:0% +coefficients just like we stuck in into +our you know when we did the free the + + align:start position:0% +our you know when we did the free the + + + align:start position:0% +our you know when we did the free the +complex Fourier series we stuck in a + + align:start position:0% +complex Fourier series we stuck in a + + + align:start position:0% +complex Fourier series we stuck in a +function of T and we get out a list of + + align:start position:0% +function of T and we get out a list of + + + align:start position:0% +function of T and we get out a list of +Fourier coefficients same thing here we + + align:start position:0% +Fourier coefficients same thing here we + + + align:start position:0% +Fourier coefficients same thing here we +put in a function of time okay and we + + align:start position:0% +put in a function of time okay and we + + + align:start position:0% +put in a function of time okay and we +get out Fourier coefficients and the + + align:start position:0% +get out Fourier coefficients and the + + + align:start position:0% +get out Fourier coefficients and the +Fourier coefficients are complex numbers + + align:start position:0% +Fourier coefficients are complex numbers + + + align:start position:0% +Fourier coefficients are complex numbers +associated with different free + + align:start position:0% +associated with different free + + + align:start position:0% +associated with different free +Quincy's know though the let's say the + + align:start position:0% +Quincy's know though the let's say the + + + align:start position:0% +Quincy's know though the let's say the +middle coefficient that you get will be + + align:start position:0% +middle coefficient that you get will be + + + align:start position:0% +middle coefficient that you get will be +the coefficient for the constant term + + align:start position:0% +the coefficient for the constant term + + + align:start position:0% +the coefficient for the constant term +right this coefficient down here will be + + align:start position:0% +right this coefficient down here will be + + + align:start position:0% +right this coefficient down here will be +the coefficient for the minimum + + align:start position:0% +the coefficient for the minimum + + + align:start position:0% +the coefficient for the minimum +frequency and that coefficient will be + + align:start position:0% +frequency and that coefficient will be + + + align:start position:0% +frequency and that coefficient will be +the coefficient for the maximum + + align:start position:0% +the coefficient for the maximum + + + align:start position:0% +the coefficient for the maximum +frequency the most positive frequency + + align:start position:0% +frequency the most positive frequency + + + align:start position:0% +frequency the most positive frequency +okay all right does that make sense + + align:start position:0% +okay all right does that make sense + + + align:start position:0% +okay all right does that make sense +ah okay so I was hoping to just kind of + + align:start position:0% +ah okay so I was hoping to just kind of + + + align:start position:0% +ah okay so I was hoping to just kind of +skip over that for now but but when you + + align:start position:0% +skip over that for now but but when you + + + align:start position:0% +skip over that for now but but when you +do a discrete Fourier transform turns + + align:start position:0% +do a discrete Fourier transform turns + + + align:start position:0% +do a discrete Fourier transform turns +out that the coefficient for the most + + align:start position:0% +out that the coefficient for the most + + + align:start position:0% +out that the coefficient for the most +negative frequency is always exactly the + + align:start position:0% +negative frequency is always exactly the + + + align:start position:0% +negative frequency is always exactly the +same as the coefficient for the most + + align:start position:0% +same as the coefficient for the most + + + align:start position:0% +same as the coefficient for the most +positive frequency okay and so and so + + align:start position:0% +positive frequency okay and so and so + + + align:start position:0% +positive frequency okay and so and so +they're just given in 1 they're both + + align:start position:0% +they're just given in 1 they're both + + + align:start position:0% +they're just given in 1 they're both +given in one element of the array okay + + align:start position:0% +given in one element of the array okay + + + align:start position:0% +given in one element of the array okay +you could replicate that up here right + + align:start position:0% +you could replicate that up here right + + + align:start position:0% +you could replicate that up here right +but it would be pointless and the length + + align:start position:0% +but it would be pointless and the length + + + align:start position:0% +but it would be pointless and the length +of the array would have to be n plus 1 + + align:start position:0% +of the array would have to be n plus 1 + + + align:start position:0% +of the array would have to be n plus 1 +ok yes + + align:start position:0% + + + + align:start position:0% + +okay good that's that it always comes up + + align:start position:0% +okay good that's that it always comes up + + + align:start position:0% +okay good that's that it always comes up +and it's a great question so what we're + + align:start position:0% +and it's a great question so what we're + + + align:start position:0% +and it's a great question so what we're +trying to do is to come up with a way of + + align:start position:0% +trying to do is to come up with a way of + + + align:start position:0% +trying to do is to come up with a way of +representing arbitrary functions right + + align:start position:0% + + + + align:start position:0% + +so we can represent symmetric functions + + align:start position:0% +so we can represent symmetric functions + + + align:start position:0% +so we can represent symmetric functions +with by summing together a bunch of + + align:start position:0% +with by summing together a bunch of + + + align:start position:0% +with by summing together a bunch of +cosines we can represent anti-symmetric + + align:start position:0% +cosines we can represent anti-symmetric + + + align:start position:0% +cosines we can represent anti-symmetric +functions by summing together a bunch of + + align:start position:0% +functions by summing together a bunch of + + + align:start position:0% +functions by summing together a bunch of +sines + + align:start position:0% +sines + + + align:start position:0% +sines +but if we want to represent an arbitrary + + align:start position:0% +but if we want to represent an arbitrary + + + align:start position:0% +but if we want to represent an arbitrary +function we have to use both cosines and + + align:start position:0% +function we have to use both cosines and + + + align:start position:0% +function we have to use both cosines and +sines right so so we have this trick + + align:start position:0% +sines right so so we have this trick + + + align:start position:0% +sines right so so we have this trick +though where we can instead of using + + align:start position:0% +though where we can instead of using + + + align:start position:0% +though where we can instead of using +sines and cosines using these two + + align:start position:0% +sines and cosines using these two + + + align:start position:0% +sines and cosines using these two +separate functions we can use a single + + align:start position:0% +separate functions we can use a single + + + align:start position:0% +separate functions we can use a single +function which is a complex exponential + + align:start position:0% +function which is a complex exponential + + + align:start position:0% +function which is a complex exponential +to represent things that can be + + align:start position:0% +to represent things that can be + + + align:start position:0% +to represent things that can be +represented by sums of cosines as well + + align:start position:0% +represented by sums of cosines as well + + + align:start position:0% +represented by sums of cosines as well +as things that can be represented as + + align:start position:0% +as things that can be represented as + + + align:start position:0% +as things that can be represented as +sums of sines so arbitrary function okay + + align:start position:0% +sums of sines so arbitrary function okay + + + align:start position:0% +sums of sines so arbitrary function okay +and the reason is because the complex + + align:start position:0% +and the reason is because the complex + + + align:start position:0% +and the reason is because the complex +exponential has both a cosine in it and + + align:start position:0% +exponential has both a cosine in it and + + + align:start position:0% +exponential has both a cosine in it and +a sine right so we can represent a + + align:start position:0% +a sine right so we can represent a + + + align:start position:0% +a sine right so we can represent a +cosine as a complex exponential with a + + align:start position:0% +cosine as a complex exponential with a + + + align:start position:0% +cosine as a complex exponential with a +positive free meaning that it's a + + align:start position:0% +positive free meaning that it's a + + + align:start position:0% +positive free meaning that it's a +complex number that goes around this + + align:start position:0% +complex number that goes around this + + + align:start position:0% +complex number that goes around this +direction plus another function where + + align:start position:0% +direction plus another function where + + + align:start position:0% +direction plus another function where +the complex number is going around in + + align:start position:0% +the complex number is going around in + + + align:start position:0% +the complex number is going around in +this direction so positive frequencies + + align:start position:0% +this direction so positive frequencies + + + align:start position:0% +this direction so positive frequencies +mean as as time in this complex number + + align:start position:0% +mean as as time in this complex number + + + align:start position:0% +mean as as time in this complex number +is going around the unit circle in this + + align:start position:0% +is going around the unit circle in this + + + align:start position:0% +is going around the unit circle in this +direction negative frequencies mean the + + align:start position:0% +direction negative frequencies mean the + + + align:start position:0% +direction negative frequencies mean the +complex number is going around in this + + align:start position:0% +complex number is going around in this + + + align:start position:0% +complex number is going around in this +direction and you can see that in order + + align:start position:0% +direction and you can see that in order + + + align:start position:0% +direction and you can see that in order +to represent a cosine I need to have + + align:start position:0% +to represent a cosine I need to have + + + align:start position:0% +to represent a cosine I need to have +okay so let's see if I can do this + + align:start position:0% +okay so let's see if I can do this + + + align:start position:0% +okay so let's see if I can do this +here's here's my e to the here's my + + align:start position:0% +here's here's my e to the here's my + + + align:start position:0% +here's here's my e to the here's my +frequency going around this way here's + + align:start position:0% +frequency going around this way here's + + + align:start position:0% +frequency going around this way here's +my minus frequency + + align:start position:0% +my minus frequency + + + align:start position:0% +my minus frequency +this way okay and you can see that I can + + align:start position:0% +this way okay and you can see that I can + + + align:start position:0% +this way okay and you can see that I can +represent a cosine if I can make the + + align:start position:0% +represent a cosine if I can make the + + + align:start position:0% +represent a cosine if I can make the +imaginary parts cancel right so if I + + align:start position:0% +imaginary parts cancel right so if I + + + align:start position:0% +imaginary parts cancel right so if I +have one function that's going around + + align:start position:0% +have one function that's going around + + + align:start position:0% +have one function that's going around +like this another function that's going + + align:start position:0% +like this another function that's going + + + align:start position:0% +like this another function that's going +around like if I add them then the + + align:start position:0% +around like if I add them then the + + + align:start position:0% +around like if I add them then the +imaginary part cancels right the the + + align:start position:0% +imaginary part cancels right the the + + + align:start position:0% +imaginary part cancels right the the +sign cancels this Plus this is cosine + + align:start position:0% +sign cancels this Plus this is cosine + + + align:start position:0% +sign cancels this Plus this is cosine +plus cosine I sine minus I sine so the + + align:start position:0% +plus cosine I sine minus I sine so the + + + align:start position:0% +plus cosine I sine minus I sine so the +signs can't the sign cancels and what + + align:start position:0% +signs can't the sign cancels and what + + + align:start position:0% +signs can't the sign cancels and what +I'm left with is a sine so represent a + + align:start position:0% +I'm left with is a sine so represent a + + + align:start position:0% +I'm left with is a sine so represent a +cosine as a sum of a function that has a + + align:start position:0% +cosine as a sum of a function that has a + + + align:start position:0% +cosine as a sum of a function that has a +positive frequency and a negative + + align:start position:0% +positive frequency and a negative + + + align:start position:0% +positive frequency and a negative +frequency you can see that the you can + + align:start position:0% +frequency you can see that the you can + + + align:start position:0% +frequency you can see that the you can +see that the Y component the imaginary + + align:start position:0% +see that the Y component the imaginary + + + align:start position:0% +see that the Y component the imaginary +component cancels and all I'm left with + + align:start position:0% +component cancels and all I'm left with + + + align:start position:0% +component cancels and all I'm left with +is the cosine that's going across like + + align:start position:0% +is the cosine that's going across like + + + align:start position:0% +is the cosine that's going across like +this okay so it's just a mathematical + + align:start position:0% +this okay so it's just a mathematical + + + align:start position:0% +this okay so it's just a mathematical +trick positive and negative frequencies + + align:start position:0% +trick positive and negative frequencies + + + align:start position:0% +trick positive and negative frequencies +are just a mathematical trick to make + + align:start position:0% +are just a mathematical trick to make + + + align:start position:0% +are just a mathematical trick to make +either the the symmetric part of the + + align:start position:0% +either the the symmetric part of the + + + align:start position:0% +either the the symmetric part of the +function or anti-symmetric part of the + + align:start position:0% +function or anti-symmetric part of the + + + align:start position:0% +function or anti-symmetric part of the +function cancel okay so I can I can just + + align:start position:0% +function cancel okay so I can I can just + + + align:start position:0% +function cancel okay so I can I can just +use these positive and negative + + align:start position:0% +use these positive and negative + + + align:start position:0% +use these positive and negative +frequencies to represent any function if + + align:start position:0% +frequencies to represent any function if + + + align:start position:0% +frequencies to represent any function if +I only had positive frequencies I + + align:start position:0% +I only had positive frequencies I + + + align:start position:0% +I only had positive frequencies I +wouldn't be able to represent arbitrary + + align:start position:0% +wouldn't be able to represent arbitrary + + + align:start position:0% +wouldn't be able to represent arbitrary +functions okay + + align:start position:0% +functions okay + + + align:start position:0% +functions okay +so just one more little thing that you + + align:start position:0% +so just one more little thing that you + + + align:start position:0% +so just one more little thing that you +need to know about the FFT algorithm so + + align:start position:0% +need to know about the FFT algorithm so + + + align:start position:0% +need to know about the FFT algorithm so +remember we talked about if you have a + + align:start position:0% +remember we talked about if you have a + + + align:start position:0% +remember we talked about if you have a +function of time negative times are over + + align:start position:0% +function of time negative times are over + + + align:start position:0% +function of time negative times are over +here positive times are over here you + + align:start position:0% +here positive times are over here you + + + align:start position:0% +here positive times are over here you +can put you can sample your function at + + align:start position:0% +can put you can sample your function at + + + align:start position:0% +can put you can sample your function at +different times and put those different + + align:start position:0% +different times and put those different + + + align:start position:0% +different times and put those different +samples into an array before you send + + align:start position:0% +samples into an array before you send + + + align:start position:0% +samples into an array before you send +this array of time samples to the FFT + + align:start position:0% +this array of time samples to the FFT + + + align:start position:0% +this array of time samples to the FFT +algorithm you just need to swap the + + align:start position:0% +algorithm you just need to swap the + + + align:start position:0% +algorithm you just need to swap the +right half of the array with the left + + align:start position:0% +right half of the array with the left + + + align:start position:0% +right half of the array with the left +half of the array using a function + + align:start position:0% +half of the array using a function + + + align:start position:0% +half of the array using a function +called time shifted array don't worry + + align:start position:0% +called time shifted array don't worry + + + align:start position:0% +called time shifted array don't worry +about it it's just the guts of the FFT + + align:start position:0% +about it it's just the guts of the FFT + + + align:start position:0% +about it it's just the guts of the FFT +algorithm wants to have the positive x + + align:start position:0% +algorithm wants to have the positive x + + + align:start position:0% +algorithm wants to have the positive x +in the first half and + + align:start position:0% +in the first half and + + + align:start position:0% +in the first half and +negative times in the second half okay + + align:start position:0% +negative times in the second half okay + + + align:start position:0% +negative times in the second half okay +so you just do this all right then you + + align:start position:0% +so you just do this all right then you + + + align:start position:0% +so you just do this all right then you +run the FFT function on this shifted + + align:start position:0% +run the FFT function on this shifted + + + align:start position:0% +run the FFT function on this shifted +time shifted array and what it spits + + align:start position:0% +time shifted array and what it spits + + + align:start position:0% +time shifted array and what it spits +back is an array with the positive + + align:start position:0% +back is an array with the positive + + + align:start position:0% +back is an array with the positive +frequencies in the first half and the + + align:start position:0% +frequencies in the first half and the + + + align:start position:0% +frequencies in the first half and the +negative frequencies in the second half + + align:start position:0% +negative frequencies in the second half + + + align:start position:0% +negative frequencies in the second half +and you can just swap those back using + + align:start position:0% +and you can just swap those back using + + + align:start position:0% +and you can just swap those back using +the search shift again that is your + + align:start position:0% +the search shift again that is your + + + align:start position:0% +the search shift again that is your +spectrum your spectral your spectral + + align:start position:0% +spectrum your spectral your spectral + + + align:start position:0% +spectrum your spectral your spectral +coefficients your Fourier coefficients + + align:start position:0% +coefficients your Fourier coefficients + + + align:start position:0% +coefficients your Fourier coefficients +of this function okay + + align:start position:0% + + + + align:start position:0% + +just MATLAB guts don't worry about it + + align:start position:0% +just MATLAB guts don't worry about it + + + align:start position:0% +just MATLAB guts don't worry about it +okay all right so here's a piece of code + + align:start position:0% +okay all right so here's a piece of code + + + align:start position:0% +okay all right so here's a piece of code +that computes the Fourier coefficients + + align:start position:0% +that computes the Fourier coefficients + + + align:start position:0% +that computes the Fourier coefficients +of a function okay so the first thing + + align:start position:0% +of a function okay so the first thing + + + align:start position:0% +of a function okay so the first thing +we're gonna do is define the number of + + align:start position:0% +we're gonna do is define the number of + + + align:start position:0% +we're gonna do is define the number of +points that we have in our array 2048 + + align:start position:0% +points that we have in our array 2048 + + + align:start position:0% +points that we have in our array 2048 +okay so it's a power of two so the FFT + + align:start position:0% +okay so it's a power of two so the FFT + + + align:start position:0% +okay so it's a power of two so the FFT +algorithm runs fast we're figuring out a + + align:start position:0% +algorithm runs fast we're figuring out a + + + align:start position:0% +algorithm runs fast we're figuring out a +we're gonna write down a delta T in this + + align:start position:0% +we're gonna write down a delta T in this + + + align:start position:0% +we're gonna write down a delta T in this +case it's one millisecond the sampling + + align:start position:0% +case it's one millisecond the sampling + + + align:start position:0% +case it's one millisecond the sampling +rate okay the sampling frequency is just + + align:start position:0% +rate okay the sampling frequency is just + + + align:start position:0% +rate okay the sampling frequency is just +one over delta T so one kilohertz the + + align:start position:0% +one over delta T so one kilohertz the + + + align:start position:0% +one over delta T so one kilohertz the +array of times at which the function is + + align:start position:0% +array of times at which the function is + + + align:start position:0% +array of times at which the function is +just going from minus n over 2 to + n + + align:start position:0% +just going from minus n over 2 to + n + + + align:start position:0% +just going from minus n over 2 to + n +over 2 minus 1 times delta T okay I'm + + align:start position:0% +over 2 minus 1 times delta T okay I'm + + + align:start position:0% +over 2 minus 1 times delta T okay I'm +defining the frequency of a sine wave + + align:start position:0% +defining the frequency of a sine wave + + + align:start position:0% +defining the frequency of a sine wave +and we're now getting the values of that + + align:start position:0% +and we're now getting the values of that + + + align:start position:0% +and we're now getting the values of that +cosine function at those different times + + align:start position:0% +cosine function at those different times + + + align:start position:0% +cosine function at those different times +that makes sense we're taking that + + align:start position:0% +that makes sense we're taking that + + + align:start position:0% +that makes sense we're taking that +function of time and circularly shifting + + align:start position:0% +function of time and circularly shifting + + + align:start position:0% +function of time and circularly shifting +it by half the array so that's the + + align:start position:0% +it by half the array so that's the + + + align:start position:0% +it by half the array so that's the +circularly shifted that the swapped + + align:start position:0% +circularly shifted that the swapped + + + align:start position:0% +circularly shifted that the swapped +values of our function why we stick that + + align:start position:0% +values of our function why we stick that + + + align:start position:0% +values of our function why we stick that +into the FFT function + + align:start position:0% +into the FFT function + + + align:start position:0% +into the FFT function +okay it gives you back the Fourier + + align:start position:0% +okay it gives you back the Fourier + + + align:start position:0% +okay it gives you back the Fourier +coefficients you just swap it again and + + align:start position:0% +coefficients you just swap it again and + + + align:start position:0% +coefficients you just swap it again and +that is the spectrum the Fourier + + align:start position:0% +that is the spectrum the Fourier + + + align:start position:0% +that is the spectrum the Fourier +transform signal okay and now you can + + align:start position:0% +transform signal okay and now you can + + + align:start position:0% +transform signal okay and now you can +write down a vector of frequencies of + + align:start position:0% +write down a vector of frequencies of + + + align:start position:0% +write down a vector of frequencies of +each one of those four eight + + align:start position:0% +each one of those four eight + + + align:start position:0% +each one of those four eight +coefficients okay each one of those + + align:start position:0% +coefficients okay each one of those + + + align:start position:0% +coefficients okay each one of those +ments in that vector Y remember there + + align:start position:0% +ments in that vector Y remember there + + + align:start position:0% +ments in that vector Y remember there +are 2,000 of them now 2048 of them each + + align:start position:0% +are 2,000 of them now 2048 of them each + + + align:start position:0% +are 2,000 of them now 2048 of them each +one of those is the Fourier coefficient + + align:start position:0% +one of those is the Fourier coefficient + + + align:start position:0% +one of those is the Fourier coefficient +of the function we put in at each one of + + align:start position:0% +of the function we put in at each one of + + + align:start position:0% +of the function we put in at each one of +those different frequencies okay that + + align:start position:0% +those different frequencies okay that + + + align:start position:0% +those different frequencies okay that +makes sense okay now let's take a look + + align:start position:0% +makes sense okay now let's take a look + + + align:start position:0% +makes sense okay now let's take a look +at a few examples of what that looks + + align:start position:0% +at a few examples of what that looks + + + align:start position:0% +at a few examples of what that looks +like so here is a function y of Y of T + + align:start position:0% +like so here is a function y of Y of T + + + align:start position:0% +like so here is a function y of Y of T +is cosine 2 pi F naught T where F naught + + align:start position:0% +is cosine 2 pi F naught T where F naught + + + align:start position:0% +is cosine 2 pi F naught T where F naught +is 20 Hertz okay so it's just a cosine + + align:start position:0% +is 20 Hertz okay so it's just a cosine + + + align:start position:0% +is 20 Hertz okay so it's just a cosine +wave you run this code on it and what + + align:start position:0% +wave you run this code on it and what + + + align:start position:0% +wave you run this code on it and what +you get back is an array of complex + + align:start position:0% +you get back is an array of complex + + + align:start position:0% +you get back is an array of complex +numbers it has a real and imaginary part + + align:start position:0% +numbers it has a real and imaginary part + + + align:start position:0% +numbers it has a real and imaginary part +as a function of frequency okay any that + + align:start position:0% +as a function of frequency okay any that + + + align:start position:0% +as a function of frequency okay any that +this cosine function has two peaks as + + align:start position:0% +this cosine function has two peaks as + + + align:start position:0% +this cosine function has two peaks as +promised right it has a peak at plus 20 + + align:start position:0% +promised right it has a peak at plus 20 + + + align:start position:0% +promised right it has a peak at plus 20 +Hertz and a peak at minus 20 Hertz one + + align:start position:0% +Hertz and a peak at minus 20 Hertz one + + + align:start position:0% +Hertz and a peak at minus 20 Hertz one +of those Peaks gives you an e to the I + + align:start position:0% +of those Peaks gives you an e to the I + + + align:start position:0% +of those Peaks gives you an e to the I +goes this way at 20 Hertz the other one + + align:start position:0% +goes this way at 20 Hertz the other one + + + align:start position:0% +goes this way at 20 Hertz the other one +gives you an e to the I Omega T that + + align:start position:0% +gives you an e to the I Omega T that + + + align:start position:0% +gives you an e to the I Omega T that +goes this way at 20 Hertz and when you + + align:start position:0% +goes this way at 20 Hertz and when you + + + align:start position:0% +goes this way at 20 Hertz and when you +add them together if I can do that it + + align:start position:0% +add them together if I can do that it + + + align:start position:0% +add them together if I can do that it +gives you a cosine that goes back and + + align:start position:0% +gives you a cosine that goes back and + + + align:start position:0% +gives you a cosine that goes back and +forth there 20 Hertz that one + + align:start position:0% +forth there 20 Hertz that one + + + align:start position:0% +forth there 20 Hertz that one +okay that's it here's a sine wave y + + align:start position:0% +okay that's it here's a sine wave y + + + align:start position:0% +okay that's it here's a sine wave y +equals sine 2 pi F naught T again at 20 + + align:start position:0% +equals sine 2 pi F naught T again at 20 + + + align:start position:0% +equals sine 2 pi F naught T again at 20 +Hertz you run that code on it it gives + + align:start position:0% +Hertz you run that code on it it gives + + + align:start position:0% +Hertz you run that code on it it gives +you this + + align:start position:0% +you this + + + align:start position:0% +you this +notice that okay + + align:start position:0% +notice that okay + + + align:start position:0% +notice that okay +sorry let me just point out one in this + + align:start position:0% +sorry let me just point out one in this + + + align:start position:0% +sorry let me just point out one in this +case the the peaks are in the real part + + align:start position:0% +case the the peaks are in the real part + + + align:start position:0% +case the the peaks are in the real part +of Y for the sine function that real + + align:start position:0% +of Y for the sine function that real + + + align:start position:0% +of Y for the sine function that real +part is zero and the peaks are in the + + align:start position:0% +part is zero and the peaks are in the + + + align:start position:0% +part is zero and the peaks are in the +imaginary part there's a plus I at minus + + align:start position:0% +imaginary part there's a plus I at minus + + + align:start position:0% +imaginary part there's a plus I at minus +20 I over 2 actually at minus 20 Hertz - + + align:start position:0% +20 I over 2 actually at minus 20 Hertz - + + + align:start position:0% +20 I over 2 actually at minus 20 Hertz - +i at plus 20 Hertz okay and what that + + align:start position:0% +i at plus 20 Hertz okay and what that + + + align:start position:0% +i at plus 20 Hertz okay and what that +does is when you multiply that + + align:start position:0% +does is when you multiply that + + + align:start position:0% +does is when you multiply that +coefficient times e to the I Omega T and + + align:start position:0% +coefficient times e to the I Omega T and + + + align:start position:0% +coefficient times e to the I Omega T and +that coefficient times whatever + + align:start position:0% +that coefficient times whatever + + + align:start position:0% +that coefficient times whatever +whichever the opposite 1 is 1 1 going + + align:start position:0% +whichever the opposite 1 is 1 1 going + + + align:start position:0% +whichever the opposite 1 is 1 1 going +this way the other one going this way + + align:start position:0% +this way the other one going this way + + + align:start position:0% +this way the other one going this way +you can see that the real part now + + align:start position:0% +you can see that the real part now + + + align:start position:0% +you can see that the real part now +cancels and what you're left with is the + + align:start position:0% +cancels and what you're left with is the + + + align:start position:0% +cancels and what you're left with is the +sine part that doesn't cancel and that + + align:start position:0% +sine part that doesn't cancel and that + + + align:start position:0% +sine part that doesn't cancel and that +and that is this this function sine + + align:start position:0% +and that is this this function sine + + + align:start position:0% +and that is this this function sine +Omega T okay + + align:start position:0% + + + + align:start position:0% + +it's about that + + align:start position:0% +it's about that + + + align:start position:0% +it's about that +that's that's kind of boring we're gonna + + align:start position:0% +that's that's kind of boring we're gonna + + + align:start position:0% +that's that's kind of boring we're gonna +put more interesting functions in here + + align:start position:0% +put more interesting functions in here + + + align:start position:0% +put more interesting functions in here +soon but I just wanted you to see what + + align:start position:0% +soon but I just wanted you to see what + + + align:start position:0% +soon but I just wanted you to see what +this algorithm does on the things that + + align:start position:0% +this algorithm does on the things that + + + align:start position:0% +this algorithm does on the things that +we've been talking about all along okay + + align:start position:0% +we've been talking about all along okay + + + align:start position:0% +we've been talking about all along okay +it gives you exactly what you expect + + align:start position:0% + + + + align:start position:0% + +number we can write down any arbitrary + + align:start position:0% +number we can write down any arbitrary + + + align:start position:0% +number we can write down any arbitrary +function as a sum of sines and cosines + + align:start position:0% + + + + align:start position:0% + +which means we can write down any + + align:start position:0% +which means we can write down any + + + align:start position:0% +which means we can write down any +arbitrary of function as a sum of these + + align:start position:0% +arbitrary of function as a sum of these + + + align:start position:0% +arbitrary of function as a sum of these +little Peaks and these peaks at + + align:start position:0% +little Peaks and these peaks at + + + align:start position:0% +little Peaks and these peaks at +different frequencies okay does that + + align:start position:0% +different frequencies okay does that + + + align:start position:0% +different frequencies okay does that +make sense so all we have to do is find + + align:start position:0% +make sense so all we have to do is find + + + align:start position:0% +make sense so all we have to do is find +these coefficients these Peaks what + + align:start position:0% +these coefficients these Peaks what + + + align:start position:0% +these coefficients these Peaks what +values of these different Peaks to stick + + align:start position:0% +values of these different Peaks to stick + + + align:start position:0% +values of these different Peaks to stick +in to reconstruct any arbitrary function + + align:start position:0% +in to reconstruct any arbitrary function + + + align:start position:0% +in to reconstruct any arbitrary function +okay and we're gonna do a lot of that in + + align:start position:0% +okay and we're gonna do a lot of that in + + + align:start position:0% +okay and we're gonna do a lot of that in +the next lecture we're going to look at + + align:start position:0% +the next lecture we're going to look at + + + align:start position:0% +the next lecture we're going to look at +what different functions here look like + + align:start position:0% +what different functions here look like + + + align:start position:0% +what different functions here look like +in the Fourier domain okay we're gonna + + align:start position:0% +in the Fourier domain okay we're gonna + + + align:start position:0% +in the Fourier domain okay we're gonna +do that for some seasons like a square + + align:start position:0% +do that for some seasons like a square + + + align:start position:0% +do that for some seasons like a square +pulse for trains of pulses for Gaussian + + align:start position:0% +pulse for trains of pulses for Gaussian + + + align:start position:0% +pulse for trains of pulses for Gaussian +or all kinds of different functions and + + align:start position:0% +or all kinds of different functions and + + + align:start position:0% +or all kinds of different functions and +then that using the convolution theorem + + align:start position:0% +then that using the convolution theorem + + + align:start position:0% +then that using the convolution theorem +you can actually just predict in your + + align:start position:0% +you can actually just predict in your + + + align:start position:0% +you can actually just predict in your +own mind what different combinations of + + align:start position:0% +own mind what different combinations of + + + align:start position:0% +own mind what different combinations of +those functions will look like okay so I + + align:start position:0% +those functions will look like okay so I + + + align:start position:0% +those functions will look like okay so I +want to end by talking about one other + + align:start position:0% +want to end by talking about one other + + + align:start position:0% +want to end by talking about one other +really critical concept called a power + + align:start position:0% +really critical concept called a power + + + align:start position:0% +really critical concept called a power +spectrum okay + + align:start position:0% +spectrum okay + + + align:start position:0% +spectrum okay +it's basically usually what you do when + + align:start position:0% +it's basically usually what you do when + + + align:start position:0% +it's basically usually what you do when +you compute the Fourier transform of a + + align:start position:0% +you compute the Fourier transform of a + + + align:start position:0% +you compute the Fourier transform of a +function is to figure out what the power + + align:start position:0% +function is to figure out what the power + + + align:start position:0% +function is to figure out what the power +spectrum is okay the simple answer is + + align:start position:0% +spectrum is okay the simple answer is + + + align:start position:0% +spectrum is okay the simple answer is +that all you do is you square this thing + + align:start position:0% +that all you do is you square this thing + + + align:start position:0% +that all you do is you square this thing +you take the magnitude squared okay but + + align:start position:0% +you take the magnitude squared okay but + + + align:start position:0% +you take the magnitude squared okay but +I'm gonna build up to that a little bit + + align:start position:0% +I'm gonna build up to that a little bit + + + align:start position:0% +I'm gonna build up to that a little bit +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +so it's called the power spectrum but + + align:start position:0% +so it's called the power spectrum but + + + align:start position:0% +so it's called the power spectrum but +first we need to understand what we mean + + align:start position:0% +first we need to understand what we mean + + + align:start position:0% +first we need to understand what we mean +by power okay so we're gonna think about + + align:start position:0% +by power okay so we're gonna think about + + + align:start position:0% +by power okay so we're gonna think about +this in the rest of a simple electrical + + align:start position:0% +this in the rest of a simple electrical + + + align:start position:0% +this in the rest of a simple electrical +circuit let's imagine that this function + + align:start position:0% +circuit let's imagine that this function + + + align:start position:0% +circuit let's imagine that this function +that were computing the Fourier + + align:start position:0% +that were computing the Fourier + + + align:start position:0% +that were computing the Fourier +transform of imagine this function is + + align:start position:0% +transform of imagine this function is + + + align:start position:0% +transform of imagine this function is +voltage that's where this idea comes + + align:start position:0% +voltage that's where this idea comes + + + align:start position:0% +voltage that's where this idea comes +from imagine that this function is the + + align:start position:0% +from imagine that this function is the + + + align:start position:0% +from imagine that this function is the +voltage that you've measured somewhere + + align:start position:0% +voltage that you've measured somewhere + + + align:start position:0% +voltage that you've measured somewhere +in a circuit let's say in this circuit + + align:start position:0% +in a circuit let's say in this circuit + + + align:start position:0% +in a circuit let's say in this circuit +right here or current either way so when + + align:start position:0% +right here or current either way so when + + + align:start position:0% +right here or current either way so when +you have current flowing through this + + align:start position:0% +you have current flowing through this + + + align:start position:0% +you have current flowing through this +circuit you can see that that that sign + + align:start position:0% +circuit you can see that that that sign + + + align:start position:0% +circuit you can see that that that sign +is so that's some oscillatory current + + align:start position:0% +is so that's some oscillatory current + + + align:start position:0% +is so that's some oscillatory current +some cosine that drives current through + + align:start position:0% +some cosine that drives current through + + + align:start position:0% +some cosine that drives current through +this resistor and when current flows + + align:start position:0% +this resistor and when current flows + + + align:start position:0% +this resistor and when current flows +through a resistor it dissipates power + + align:start position:0% +through a resistor it dissipates power + + + align:start position:0% +through a resistor it dissipates power +right and the power dissipated in a + + align:start position:0% +right and the power dissipated in a + + + align:start position:0% +right and the power dissipated in a +resistor is just the current times the + + align:start position:0% +resistor is just the current times the + + + align:start position:0% +resistor is just the current times the +voltage drop across that resistor that + + align:start position:0% +voltage drop across that resistor that + + + align:start position:0% +voltage drop across that resistor that +means that the power + + align:start position:0% +means that the power + + + align:start position:0% +means that the power +now remember Ohm's law tells you that + + align:start position:0% +now remember Ohm's law tells you that + + + align:start position:0% +now remember Ohm's law tells you that +current is just pitch divided by + + align:start position:0% +current is just pitch divided by + + + align:start position:0% +current is just pitch divided by +resistance right so this is V divided by + + align:start position:0% +resistance right so this is V divided by + + + align:start position:0% +resistance right so this is V divided by +R so the power is just V squared divided + + align:start position:0% +R so the power is just V squared divided + + + align:start position:0% +R so the power is just V squared divided +by R so if the voltage is just a sine + + align:start position:0% +by R so if the voltage is just a sine + + + align:start position:0% +by R so if the voltage is just a sine +wave at frequency Omega then V is some + + align:start position:0% +wave at frequency Omega then V is some + + + align:start position:0% +wave at frequency Omega then V is some +efficient some amplitude at that + + align:start position:0% +efficient some amplitude at that + + + align:start position:0% +efficient some amplitude at that +frequency times cosine Omega T right we + + align:start position:0% +frequency times cosine Omega T right we + + + align:start position:0% +frequency times cosine Omega T right we +can write that voltage using Euler's + + align:start position:0% +can write that voltage using Euler's + + + align:start position:0% +can write that voltage using Euler's +equation as one-half e to the minus I + + align:start position:0% +equation as one-half e to the minus I + + + align:start position:0% +equation as one-half e to the minus I +Omega T plus one-half e to the plus I + + align:start position:0% +Omega T plus one-half e to the plus I + + + align:start position:0% +Omega T plus one-half e to the plus I +Omega T and let's calculate the power + + align:start position:0% +Omega T and let's calculate the power + + + align:start position:0% +Omega T and let's calculate the power +associated with that voltage well we + + align:start position:0% +associated with that voltage well we + + + align:start position:0% +associated with that voltage well we +have to average over one cycle of that + + align:start position:0% +have to average over one cycle of that + + + align:start position:0% +have to average over one cycle of that +oscillation so the average power is just + + align:start position:0% +oscillation so the average power is just + + + align:start position:0% +oscillation so the average power is just +given by the square magnitude of the + + align:start position:0% +given by the square magnitude of the + + + align:start position:0% +given by the square magnitude of the +Fourier transform so let's just plug + + align:start position:0% +Fourier transform so let's just plug + + + align:start position:0% +Fourier transform so let's just plug +this into here and what you see is that + + align:start position:0% +this into here and what you see is that + + + align:start position:0% +this into here and what you see is that +the power at a given frequency Omega is + + align:start position:0% +the power at a given frequency Omega is + + + align:start position:0% +the power at a given frequency Omega is +just that coefficient magnitude squared + + align:start position:0% +just that coefficient magnitude squared + + + align:start position:0% +just that coefficient magnitude squared +over resistance + + align:start position:0% +over resistance + + + align:start position:0% +over resistance +times 1/2 e to the minus I Omega T + + align:start position:0% +times 1/2 e to the minus I Omega T + + + align:start position:0% +times 1/2 e to the minus I Omega T +magnitude squared plus 1/2 e to the plus + + align:start position:0% +magnitude squared plus 1/2 e to the plus + + + align:start position:0% +magnitude squared plus 1/2 e to the plus +I over I Omega T magnitude squared and + + align:start position:0% +I over I Omega T magnitude squared and + + + align:start position:0% +I over I Omega T magnitude squared and +that's just equal to 1 over R that + + align:start position:0% +that's just equal to 1 over R that + + + align:start position:0% +that's just equal to 1 over R that +coefficient magnitude squared over 2 ok + + align:start position:0% +coefficient magnitude squared over 2 ok + + + align:start position:0% +coefficient magnitude squared over 2 ok +so you can see that the power dissipated + + align:start position:0% +so you can see that the power dissipated + + + align:start position:0% +so you can see that the power dissipated +by this sinusoidal voltage is just that + + align:start position:0% +by this sinusoidal voltage is just that + + + align:start position:0% +by this sinusoidal voltage is just that +magnitude squared over 2 ok so we can + + align:start position:0% +magnitude squared over 2 ok so we can + + + align:start position:0% +magnitude squared over 2 ok so we can +calculate the power dissipated in any + + align:start position:0% +calculate the power dissipated in any + + + align:start position:0% +calculate the power dissipated in any +resistor simply by summing up this + + align:start position:0% +resistor simply by summing up this + + + align:start position:0% +resistor simply by summing up this +magnitude of all of those coefficients + + align:start position:0% +magnitude of all of those coefficients + + + align:start position:0% +magnitude of all of those coefficients +ok so let's look at that you know a + + align:start position:0% +ok so let's look at that you know a + + + align:start position:0% +ok so let's look at that you know a +little more detail so let's think for a + + align:start position:0% +little more detail so let's think for a + + + align:start position:0% +little more detail so let's think for a +moment about the energy that is + + align:start position:0% +moment about the energy that is + + + align:start position:0% +moment about the energy that is +dissipated by a signal ok so energy is + + align:start position:0% +dissipated by a signal ok so energy is + + + align:start position:0% +dissipated by a signal ok so energy is +just the integral over all right + + align:start position:0% +just the integral over all right + + + align:start position:0% +just the integral over all right +power is per unit time total energy is + + align:start position:0% +power is per unit time total energy is + + + align:start position:0% +power is per unit time total energy is +just the integral of the power over time + + align:start position:0% +just the integral of the power over time + + + align:start position:0% +just the integral of the power over time +so power was just is just equal to V + + align:start position:0% +so power was just is just equal to V + + + align:start position:0% +so power was just is just equal to V +squared over R so I'm just gonna + + align:start position:0% +squared over R so I'm just gonna + + + align:start position:0% +squared over R so I'm just gonna +substitute that in there so the energy + + align:start position:0% +substitute that in there so the energy + + + align:start position:0% +substitute that in there so the energy +of a signal is just 1 over R times the + + align:start position:0% +of a signal is just 1 over R times the + + + align:start position:0% +of a signal is just 1 over R times the +integral of V squared over time right + + align:start position:0% + + + + align:start position:0% + +now there's a important theorem in + + align:start position:0% +now there's a important theorem in + + + align:start position:0% +now there's a important theorem in +complex analysis called parseval's + + align:start position:0% +complex analysis called parseval's + + + align:start position:0% +complex analysis called parseval's +theorem that says that the integral over + + align:start position:0% +theorem that says that the integral over + + + align:start position:0% +theorem that says that the integral over +the square of the coefficients in time + + align:start position:0% +the square of the coefficients in time + + + align:start position:0% +the square of the coefficients in time +is just equal to the integral of the + + align:start position:0% +is just equal to the integral of the + + + align:start position:0% +is just equal to the integral of the +square magnitude coefficients in + + align:start position:0% +square magnitude coefficients in + + + align:start position:0% +square magnitude coefficients in +frequency ok + + align:start position:0% + + + + align:start position:0% + +what that's saying is that is just the + + align:start position:0% +what that's saying is that is just the + + + align:start position:0% +what that's saying is that is just the +same as the total power and the Sigma or + + align:start position:0% +same as the total power and the Sigma or + + + align:start position:0% +same as the total power and the Sigma or +the total energy in a signal if you + + align:start position:0% +the total energy in a signal if you + + + align:start position:0% +the total energy in a signal if you +represent it in the time domain is just + + align:start position:0% +represent it in the time domain is just + + + align:start position:0% +represent it in the time domain is just +the same as the total energy in the + + align:start position:0% +the same as the total energy in the + + + align:start position:0% +the same as the total energy in the +signal if you look at it in the + + align:start position:0% +signal if you look at it in the + + + align:start position:0% +signal if you look at it in the +frequency domain okay and what that's + + align:start position:0% +frequency domain okay and what that's + + + align:start position:0% +frequency domain okay and what that's +saying is that the sum of all the + + align:start position:0% +saying is that the sum of all the + + + align:start position:0% +saying is that the sum of all the +squared component the squared temporal + + align:start position:0% +squared component the squared temporal + + + align:start position:0% +squared component the squared temporal +components is just equal to the sum of + + align:start position:0% +components is just equal to the sum of + + + align:start position:0% +components is just equal to the sum of +all the squared frequency components + + align:start position:0% +all the squared frequency components + + + align:start position:0% +all the squared frequency components +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and what that means is that you can see + + align:start position:0% +and what that means is that you can see + + + align:start position:0% +and what that means is that you can see +that each of these frequency components + + align:start position:0% +that each of these frequency components + + + align:start position:0% +that each of these frequency components +each each component in frequency + + align:start position:0% +each each component in frequency + + + align:start position:0% +each each component in frequency +contributes independently to the power + + align:start position:0% +contributes independently to the power + + + align:start position:0% +contributes independently to the power +in the signal okay what that means is + + align:start position:0% +in the signal okay what that means is + + + align:start position:0% +in the signal okay what that means is +that you can think of so you can think + + align:start position:0% +that you can think of so you can think + + + align:start position:0% +that you can think of so you can think +of the total energy and the signal is + + align:start position:0% +of the total energy and the signal is + + + align:start position:0% +of the total energy and the signal is +just the integral over all frequencies + + align:start position:0% +just the integral over all frequencies + + + align:start position:0% +just the integral over all frequencies +of this quantity here that we call the + + align:start position:0% +of this quantity here that we call the + + + align:start position:0% +of this quantity here that we call the +power spectrum okay and so we'll often + + align:start position:0% +power spectrum okay and so we'll often + + + align:start position:0% +power spectrum okay and so we'll often +take a signal calculate the Fourier + + align:start position:0% +take a signal calculate the Fourier + + + align:start position:0% +take a signal calculate the Fourier +components and plot Erev the Fourier + + align:start position:0% +components and plot Erev the Fourier + + + align:start position:0% +components and plot Erev the Fourier +transform the square magnitude of the + + align:start position:0% +transform the square magnitude of the + + + align:start position:0% +transform the square magnitude of the +Fourier transform and that's called the + + align:start position:0% +Fourier transform and that's called the + + + align:start position:0% +Fourier transform and that's called the +power spectrum + + align:start position:0% +power spectrum + + + align:start position:0% +power spectrum +okay we've art and I've already said + + align:start position:0% +okay we've art and I've already said + + + align:start position:0% +okay we've art and I've already said +it's the total variance of the signal + + align:start position:0% +it's the total variance of the signal + + + align:start position:0% +it's the total variance of the signal +and time is the same as the total + + align:start position:0% +and time is the same as the total + + + align:start position:0% +and time is the same as the total +variance of the signal in the frequency + + align:start position:0% +variance of the signal in the frequency + + + align:start position:0% +variance of the signal in the frequency +domain + + align:start position:0% +domain + + + align:start position:0% +domain +so Mathew people talk about the variant + + align:start position:0% +so Mathew people talk about the variant + + + align:start position:0% +so Mathew people talk about the variant +of a signal and more engineering people + + align:start position:0% +of a signal and more engineering people + + + align:start position:0% +of a signal and more engineering people +talk about the power in the signal but + + align:start position:0% +talk about the power in the signal but + + + align:start position:0% +talk about the power in the signal but +they're really talking about the same + + align:start position:0% +they're really talking about the same + + + align:start position:0% +they're really talking about the same +thing okay so let's take this example + + align:start position:0% +thing okay so let's take this example + + + align:start position:0% +thing okay so let's take this example +that we just looked at and look at the + + align:start position:0% +that we just looked at and look at the + + + align:start position:0% +that we just looked at and look at the +power spectrum okay so that's a code + + align:start position:0% +power spectrum okay so that's a code + + + align:start position:0% +power spectrum okay so that's a code +function as these two peaks + + align:start position:0% + + + + align:start position:0% + +now let me just point out one more + + align:start position:0% +now let me just point out one more + + + align:start position:0% +now let me just point out one more +important thing for real functions so in + + align:start position:0% +important thing for real functions so in + + + align:start position:0% +important thing for real functions so in +this class we're only going to be + + align:start position:0% +this class we're only going to be + + + align:start position:0% +this class we're only going to be +talking about real functions of time for + + align:start position:0% +talking about real functions of time for + + + align:start position:0% +talking about real functions of time for +real function the square magnitude of + + align:start position:0% +real function the square magnitude of + + + align:start position:0% +real function the square magnitude of +the Fourier transform is symmetric okay + + align:start position:0% +the Fourier transform is symmetric okay + + + align:start position:0% +the Fourier transform is symmetric okay +so you can see here if there's a peak on + + align:start position:0% +so you can see here if there's a peak on + + + align:start position:0% +so you can see here if there's a peak on +the in the positive frequencies there's + + align:start position:0% +the in the positive frequencies there's + + + align:start position:0% +the in the positive frequencies there's +an equivalent peak in the negative + + align:start position:0% +an equivalent peak in the negative + + + align:start position:0% +an equivalent peak in the negative +frequencies so when we plot the power + + align:start position:0% +frequencies so when we plot the power + + + align:start position:0% +frequencies so when we plot the power +spectrum of a signal we always just plot + + align:start position:0% +spectrum of a signal we always just plot + + + align:start position:0% +spectrum of a signal we always just plot +the positive side okay and so here's + + align:start position:0% +the positive side okay and so here's + + + align:start position:0% +the positive side okay and so here's +what that looks like here is the power + + align:start position:0% +what that looks like here is the power + + + align:start position:0% +what that looks like here is the power +spectrum of a cosine signal okay and + + align:start position:0% +spectrum of a cosine signal okay and + + + align:start position:0% +spectrum of a cosine signal okay and +it's just a single peak so in that case + + align:start position:0% +it's just a single peak so in that case + + + align:start position:0% +it's just a single peak so in that case +it was a cosine at 20 Hertz you get a + + align:start position:0% +it was a cosine at 20 Hertz you get a + + + align:start position:0% +it was a cosine at 20 Hertz you get a +single peak at 20 Hertz right well what + + align:start position:0% +single peak at 20 Hertz right well what + + + align:start position:0% +single peak at 20 Hertz right well what +what does it look like for a sine + + align:start position:0% +what does it look like for a sine + + + align:start position:0% +what does it look like for a sine +function what is the power spectrum of a + + align:start position:0% +function what is the power spectrum of a + + + align:start position:0% +function what is the power spectrum of a +sine function remember in that case it + + align:start position:0% +sine function remember in that case it + + + align:start position:0% +sine function remember in that case it +was the real part was zero and the + + align:start position:0% +was the real part was zero and the + + + align:start position:0% +was the real part was zero and the +imaginary part at a plus peak here and a + + align:start position:0% +imaginary part at a plus peak here and a + + + align:start position:0% +imaginary part at a plus peak here and a +minus peak here what is the spectrum of + + align:start position:0% +minus peak here what is the spectrum of + + + align:start position:0% +minus peak here what is the spectrum of +that look like right the square + + align:start position:0% +that look like right the square + + + align:start position:0% +that look like right the square +magnitude of I is just one right + + align:start position:0% +magnitude of I is just one right + + + align:start position:0% +magnitude of I is just one right +magnitude squared of I is just one so + + align:start position:0% +magnitude squared of I is just one so + + + align:start position:0% +magnitude squared of I is just one so +the power spectrum of a sine function + + align:start position:0% +the power spectrum of a sine function + + + align:start position:0% +the power spectrum of a sine function +looks exactly like this same as cosine + + align:start position:0% +looks exactly like this same as cosine + + + align:start position:0% +looks exactly like this same as cosine +it makes a lot of sense right sine and + + align:start position:0% +it makes a lot of sense right sine and + + + align:start position:0% +it makes a lot of sense right sine and +cosine are exactly the same function + + align:start position:0% +cosine are exactly the same function + + + align:start position:0% +cosine are exactly the same function +one's just shifted as by you know a + + align:start position:0% +one's just shifted as by you know a + + + align:start position:0% +one's just shifted as by you know a +quarter period right so it has to have + + align:start position:0% +quarter period right so it has to have + + + align:start position:0% +quarter period right so it has to have +the same power spectrum it has to have + + align:start position:0% +the same power spectrum it has to have + + + align:start position:0% +the same power spectrum it has to have +the same power okay all right let's take + + align:start position:0% +the same power okay all right let's take + + + align:start position:0% +the same power okay all right let's take +a look at a different function of time + + align:start position:0% +a look at a different function of time + + + align:start position:0% +a look at a different function of time +there's a train of delta function so we + + align:start position:0% +there's a train of delta function so we + + + align:start position:0% +there's a train of delta function so we +just have a bunch of Peaks spaced + + align:start position:0% +just have a bunch of Peaks spaced + + + align:start position:0% +just have a bunch of Peaks spaced +regularly at some period I think it was + + align:start position:0% +regularly at some period I think it was + + + align:start position:0% +regularly at some period I think it was +forget the exact number here but it's + + align:start position:0% +forget the exact number here but it's + + + align:start position:0% +forget the exact number here but it's +around 10-ish Hertz + + align:start position:0% + + + + align:start position:0% + +Fourier transform of a train of Delta + + align:start position:0% +Fourier transform of a train of Delta + + + align:start position:0% +Fourier transform of a train of Delta +functions is another train of Delta + + align:start position:0% +functions is another train of Delta + + + align:start position:0% +functions is another train of Delta +functions okay pretty cool the period in + + align:start position:0% +functions okay pretty cool the period in + + + align:start position:0% +functions okay pretty cool the period in +the time domain is delta T the period in + + align:start position:0% +the time domain is delta T the period in + + + align:start position:0% +the time domain is delta T the period in +the Fourier domain is 1 over delta T ok + + align:start position:0% +the Fourier domain is 1 over delta T ok + + + align:start position:0% +the Fourier domain is 1 over delta T ok +that's another really important for you + + align:start position:0% +that's another really important for you + + + align:start position:0% +that's another really important for you +transform pair for you to know + + align:start position:0% +transform pair for you to know + + + align:start position:0% +transform pair for you to know +so the first Fourier transform pair that + + align:start position:0% +so the first Fourier transform pair that + + + align:start position:0% +so the first Fourier transform pair that +you need to know is that a constant in + + align:start position:0% +you need to know is that a constant in + + + align:start position:0% +you need to know is that a constant in +the time domain is a delta function in + + align:start position:0% +the time domain is a delta function in + + + align:start position:0% +the time domain is a delta function in +the frequency domain a delta function in + + align:start position:0% +the frequency domain a delta function in + + + align:start position:0% +the frequency domain a delta function in +the time domain is a constant in the + + align:start position:0% +the time domain is a constant in the + + + align:start position:0% +the time domain is a constant in the +frequency domain a train of Delta + + align:start position:0% +frequency domain a train of Delta + + + align:start position:0% +frequency domain a train of Delta +functions in the train is a train of + + align:start position:0% +functions in the train is a train of + + + align:start position:0% +functions in the train is a train of +functions in the frequency domain and + + align:start position:0% +functions in the frequency domain and + + + align:start position:0% +functions in the frequency domain and +vice versa right and there's a very + + align:start position:0% +vice versa right and there's a very + + + align:start position:0% +vice versa right and there's a very +simple relation between the period and + + align:start position:0% +simple relation between the period and + + + align:start position:0% +simple relation between the period and +the time domain and the period in the + + align:start position:0% +the time domain and the period in the + + + align:start position:0% +the time domain and the period in the +frequency domain what does the power + + align:start position:0% +frequency domain what does the power + + + align:start position:0% +frequency domain what does the power +spectrum of this train of Delta + + align:start position:0% +spectrum of this train of Delta + + + align:start position:0% +spectrum of this train of Delta +functions look like + + align:start position:0% + + + + align:start position:0% + +it's just the square magnitude of this + + align:start position:0% +it's just the square magnitude of this + + + align:start position:0% +it's just the square magnitude of this +right so it just looks like a bunch of + + align:start position:0% +right so it just looks like a bunch of + + + align:start position:0% +right so it just looks like a bunch of +Peaks okay + + align:start position:0% +Peaks okay + + + align:start position:0% +Peaks okay +so here's another function a square wave + + align:start position:0% +so here's another function a square wave + + + align:start position:0% +so here's another function a square wave +this is exactly the same function that + + align:start position:0% +this is exactly the same function that + + + align:start position:0% +this is exactly the same function that +we started with if you look at the + + align:start position:0% +we started with if you look at the + + + align:start position:0% +we started with if you look at the +Fourier transform of the imaginary part + + align:start position:0% +Fourier transform of the imaginary part + + + align:start position:0% +Fourier transform of the imaginary part +is zero the real part has these Peaks so + + align:start position:0% +is zero the real part has these Peaks so + + + align:start position:0% +is zero the real part has these Peaks so +the Fourier transforms + + align:start position:0% +the Fourier transforms + + + align:start position:0% +the Fourier transforms +that you would put in front of your + + align:start position:0% +that you would put in front of your + + + align:start position:0% +that you would put in front of your +different cosines at different + + align:start position:0% +different cosines at different + + + align:start position:0% +different cosines at different +frequencies to represent the square wave + + align:start position:0% +frequencies to represent the square wave + + + align:start position:0% +frequencies to represent the square wave +okay so what it looks like is positive + + align:start position:0% +okay so what it looks like is positive + + + align:start position:0% +okay so what it looks like is positive +peak for the lowest frequency negative + + align:start position:0% +peak for the lowest frequency negative + + + align:start position:0% +peak for the lowest frequency negative +peak for the next harmonic positive peak + + align:start position:0% +peak for the next harmonic positive peak + + + align:start position:0% +peak for the next harmonic positive peak +and and gradually decreasing amplitudes + + align:start position:0% +and and gradually decreasing amplitudes + + + align:start position:0% +and and gradually decreasing amplitudes +okay the power spectrum of this oh and + + align:start position:0% +okay the power spectrum of this oh and + + + align:start position:0% +okay the power spectrum of this oh and +one more point is that if you look at + + align:start position:0% +one more point is that if you look at + + + align:start position:0% +one more point is that if you look at +the Fourier transform of a higher + + align:start position:0% +the Fourier transform of a higher + + + align:start position:0% +the Fourier transform of a higher +frequency square wave you can see that + + align:start position:0% +frequency square wave you can see that + + + align:start position:0% +frequency square wave you can see that +those Peaks move apart okay so you can + + align:start position:0% +those Peaks move apart okay so you can + + + align:start position:0% +those Peaks move apart okay so you can +transform so higher frequencies in the + + align:start position:0% +transform so higher frequencies in the + + + align:start position:0% +transform so higher frequencies in the +time domain stuff happening faster in + + align:start position:0% +time domain stuff happening faster in + + + align:start position:0% +time domain stuff happening faster in +the timing is associated with things + + align:start position:0% +the timing is associated with things + + + align:start position:0% +the timing is associated with things +moving out to higher frequencies in the + + align:start position:0% +moving out to higher frequencies in the + + + align:start position:0% +moving out to higher frequencies in the +frequency domain you can see that the + + align:start position:0% +frequency domain you can see that the + + + align:start position:0% +frequency domain you can see that the +same function higher frequencies has the + + align:start position:0% +same function higher frequencies has the + + + align:start position:0% +same function higher frequencies has the +same Fourier transform but with the + + align:start position:0% +same Fourier transform but with the + + + align:start position:0% +same Fourier transform but with the +components spread out to higher + + align:start position:0% +components spread out to higher + + + align:start position:0% +components spread out to higher +frequencies okay and the power spectrum + + align:start position:0% +frequencies okay and the power spectrum + + + align:start position:0% +frequencies okay and the power spectrum +except this and notice that one more + + align:start position:0% +except this and notice that one more + + + align:start position:0% +except this and notice that one more +final point here is that when you look + + align:start position:0% +final point here is that when you look + + + align:start position:0% +final point here is that when you look +at power spectra often signals can have + + align:start position:0% +at power spectra often signals can have + + + align:start position:0% +at power spectra often signals can have +frequency components that are at that + + align:start position:0% +frequency components that are at that + + + align:start position:0% +frequency components that are at that +are very small so that it's hard to see + + align:start position:0% +are very small so that it's hard to see + + + align:start position:0% +are very small so that it's hard to see +them on a linear scale and so we + + align:start position:0% +them on a linear scale and so we + + + align:start position:0% +them on a linear scale and so we +actually plot them in this method you + + align:start position:0% +actually plot them in this method you + + + align:start position:0% +actually plot them in this method you +plot them in units of decibels and I'll + + align:start position:0% +plot them in units of decibels and I'll + + + align:start position:0% +plot them in units of decibels and I'll +explain what those are the next time but + + align:start position:0% +explain what those are the next time but + + + align:start position:0% +explain what those are the next time but +that's another representation of the + + align:start position:0% +that's another representation of the + + + align:start position:0% +that's another representation of the +power spectrum + + align:start position:0% +power spectrum + + + align:start position:0% +power spectrum +of of a signal okay so that's what we've + + align:start position:0% +of of a signal okay so that's what we've + + + align:start position:0% +of of a signal okay so that's what we've +covered and we're going to continue with + + align:start position:0% +covered and we're going to continue with + + + align:start position:0% +covered and we're going to continue with +the gameplan next time + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/4oIsQdCjMeE.txt b/4oIsQdCjMeE.txt new file mode 100644 index 0000000000000000000000000000000000000000..c3562af4f4c69378aa2786491a979a9f1588d551 --- /dev/null +++ b/4oIsQdCjMeE.txt @@ -0,0 +1,10008 @@ +align:start position:0% + +chiefly in mind here uh two are coming + + align:start position:0% +chiefly in mind here uh two are coming + + + align:start position:0% +chiefly in mind here uh two are coming +from last time uh I wanted to say just a + + align:start position:0% +from last time uh I wanted to say just a + + + align:start position:0% +from last time uh I wanted to say just a +little more about this neat theorem of + + align:start position:0% +little more about this neat theorem of + + + align:start position:0% +little more about this neat theorem of +Max flow Min cut this was a this was a + + align:start position:0% +Max flow Min cut this was a this was a + + + align:start position:0% +Max flow Min cut this was a this was a +do an example of Duality and a + + align:start position:0% +do an example of Duality and a + + + align:start position:0% +do an example of Duality and a +particularly nice one and uh um chapter + + align:start position:0% +particularly nice one and uh um chapter + + + align:start position:0% +particularly nice one and uh um chapter +7 of the book has uh examples and and + + align:start position:0% +7 of the book has uh examples and and + + + align:start position:0% +7 of the book has uh examples and and +more discussion of that then + + align:start position:0% +more discussion of that then + + + align:start position:0% +more discussion of that then +um you were kind enough to get involved + + align:start position:0% +um you were kind enough to get involved + + + align:start position:0% +um you were kind enough to get involved +in my new uh interest which was well the + + align:start position:0% +in my new uh interest which was well the + + + align:start position:0% +in my new uh interest which was well the +specific question was uh when can I + + align:start position:0% +specific question was uh when can I + + + align:start position:0% +specific question was uh when can I +complete a matrix given some of its + + align:start position:0% +complete a matrix given some of its + + + align:start position:0% +complete a matrix given some of its +entries when can I finish it out to have + + align:start position:0% +entries when can I finish it out to have + + + align:start position:0% +entries when can I finish it out to have +rank one and I have some news so of + + align:start position:0% +rank one and I have some news so of + + + align:start position:0% +rank one and I have some news so of +course I'm eager to tell you about it + + align:start position:0% +course I'm eager to tell you about it + + + align:start position:0% +course I'm eager to tell you about it +and uh and then the + + align:start position:0% +and uh and then the + + + align:start position:0% +and uh and then the +I I realized that it might be a pleasure + + align:start position:0% +I I realized that it might be a pleasure + + + align:start position:0% +I I realized that it might be a pleasure +to talk about Game Theory as another uh + + align:start position:0% +to talk about Game Theory as another uh + + + align:start position:0% +to talk about Game Theory as another uh +two person this is twers game theory + + align:start position:0% +two person this is twers game theory + + + align:start position:0% +two person this is twers game theory +created by uh V + + align:start position:0% +created by uh V + + + align:start position:0% +created by uh V +noyman and + + align:start position:0% + + + + align:start position:0% + +uh uh it's another example of Duality uh + + align:start position:0% +uh uh it's another example of Duality uh + + + align:start position:0% +uh uh it's another example of Duality uh +but uh just coming from somewhere from + + align:start position:0% +but uh just coming from somewhere from + + + align:start position:0% +but uh just coming from somewhere from +such a different source that it wasn't + + align:start position:0% +such a different source that it wasn't + + + align:start position:0% +such a different source that it wasn't +recognized uh for a little while that + + align:start position:0% +recognized uh for a little while that + + + align:start position:0% +recognized uh for a little while that +that it fit the framework okay with Max + + align:start position:0% +that it fit the framework okay with Max + + + align:start position:0% +that it fit the framework okay with Max +flow Min cut I just have this uh uh + + align:start position:0% +flow Min cut I just have this uh uh + + + align:start position:0% +flow Min cut I just have this uh uh +example to mention uh suppose all the + + align:start position:0% +example to mention uh suppose all the + + + align:start position:0% +example to mention uh suppose all the +capacities are + + align:start position:0% +capacities are + + + align:start position:0% +capacities are +one on the edges so on every Edge we can + + align:start position:0% +one on the edges so on every Edge we can + + + align:start position:0% +one on the edges so on every Edge we can +send one um uh unit how well in this + + align:start position:0% +send one um uh unit how well in this + + + align:start position:0% +send one um uh unit how well in this +example let's say how much could I get + + align:start position:0% +example let's say how much could I get + + + align:start position:0% +example let's say how much could I get +from the source to the sink + + align:start position:0% +from the source to the sink + + + align:start position:0% +from the source to the sink +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +well along those + + align:start position:0% +well along those + + + align:start position:0% +well along those +edges okay uh oh have I made it so I + + align:start position:0% +edges okay uh oh have I made it so I + + + align:start position:0% +edges okay uh oh have I made it so I +could + + align:start position:0% +could + + + align:start position:0% +could +get + + align:start position:0% +get + + + align:start position:0% +get +four could I get four through on + + align:start position:0% +four could I get four through on + + + align:start position:0% +four could I get four through on +that yes I think I + + align:start position:0% +that yes I think I + + + align:start position:0% +that yes I think I +could right because yeah so let me let + + align:start position:0% +could right because yeah so let me let + + + align:start position:0% +could right because yeah so let me let +me uh make it a little harder let me add + + align:start position:0% +me uh make it a little harder let me add + + + align:start position:0% +me uh make it a little harder let me add +another Edge + + align:start position:0% +another Edge + + + align:start position:0% +another Edge +there so hopefully I could get more + + align:start position:0% +there so hopefully I could get more + + + align:start position:0% +there so hopefully I could get more +through but I think I can't I think uh + + align:start position:0% +through but I think I can't I think uh + + + align:start position:0% +through but I think I can't I think uh +that how much could I now get through + + align:start position:0% +that how much could I now get through + + + align:start position:0% +that how much could I now get through +from the source to the sink there are 1 + + align:start position:0% +from the source to the sink there are 1 + + + align:start position:0% +from the source to the sink there are 1 +two 3 four five edges leaving the sink + + align:start position:0% +two 3 four five edges leaving the sink + + + align:start position:0% +two 3 four five edges leaving the sink +and then they go different + + align:start position:0% +and then they go different + + + align:start position:0% +and then they go different +places uh and there could be as we had + + align:start position:0% +places uh and there could be as we had + + + align:start position:0% +places uh and there could be as we had +last time uh uh the the bottleneck could + + align:start position:0% +last time uh uh the the bottleneck could + + + align:start position:0% +last time uh uh the the bottleneck could +be in the middle of the of the path or + + align:start position:0% +be in the middle of the of the path or + + + align:start position:0% +be in the middle of the of the path or +it could be right here at the uh sink + + align:start position:0% +it could be right here at the uh sink + + + align:start position:0% +it could be right here at the uh sink +maybe it is maybe in this case I can + + align:start position:0% +maybe it is maybe in this case I can + + + align:start position:0% +maybe it is maybe in this case I can +only get four I could even + + align:start position:0% +only get four I could even + + + align:start position:0% +only get four I could even +uh yeah I could I think maybe the + + align:start position:0% +uh yeah I could I think maybe the + + + align:start position:0% +uh yeah I could I think maybe the +maximal capacity is + + align:start position:0% +maximal capacity is + + + align:start position:0% +maximal capacity is +four agreed yeah and the cut that that + + align:start position:0% +four agreed yeah and the cut that that + + + align:start position:0% +four agreed yeah and the cut that that +shows me that proves it is actually well + + align:start position:0% +shows me that proves it is actually well + + + align:start position:0% +shows me that proves it is actually well +in this case sort of a degenerate case + + align:start position:0% +in this case sort of a degenerate case + + + align:start position:0% +in this case sort of a degenerate case +the sink is all by himself in the cut so + + align:start position:0% +the sink is all by himself in the cut so + + + align:start position:0% +the sink is all by himself in the cut so +there's a cut of one 2 three and four + + align:start position:0% +there's a cut of one 2 three and four + + + align:start position:0% +there's a cut of one 2 three and four +edges getting through and that's the + + align:start position:0% +edges getting through and that's the + + + align:start position:0% +edges getting through and that's the +maximum flow also + + align:start position:0% +maximum flow also + + + align:start position:0% +maximum flow also +and what I let let me draw the the paths + + align:start position:0% +and what I let let me draw the the paths + + + align:start position:0% +and what I let let me draw the the paths +that that it could follow one set of + + align:start position:0% +that that it could follow one set of + + + align:start position:0% +that that it could follow one set of +paths that it could follow uh let's see + + align:start position:0% +paths that it could follow uh let's see + + + align:start position:0% +paths that it could follow uh let's see +I could send one along this + + align:start position:0% +I could send one along this + + + align:start position:0% +I could send one along this +path and I could send one along this + + align:start position:0% +path and I could send one along this + + + align:start position:0% +path and I could send one along this +this path and one around here and one + + align:start position:0% +this path and one around here and one + + + align:start position:0% +this path and one around here and one +around straight through there + + align:start position:0% +around straight through there + + + align:start position:0% +around straight through there +so those notice that those paths are + + align:start position:0% +so those notice that those paths are + + + align:start position:0% +so those notice that those paths are +disjoint separate paths uh the and they + + align:start position:0% +disjoint separate paths uh the and they + + + align:start position:0% +disjoint separate paths uh the and they +have to be right with the + + align:start position:0% +have to be right with the + + + align:start position:0% +have to be right with the +with with this kind of flow I'm not + + align:start position:0% +with with this kind of flow I'm not + + + align:start position:0% +with with this kind of flow I'm not +going to gain anything by sharing by + + align:start position:0% +going to gain anything by sharing by + + + align:start position:0% +going to gain anything by sharing by +having uh by by sharing an edge with two + + align:start position:0% +having uh by by sharing an edge with two + + + align:start position:0% +having uh by by sharing an edge with two +flows so what I'm trying to say is that + + align:start position:0% +flows so what I'm trying to say is that + + + align:start position:0% +flows so what I'm trying to say is that +for this + + align:start position:0% +for this + + + align:start position:0% +for this +example uh it the max flow equal Min cut + + align:start position:0% +example uh it the max flow equal Min cut + + + align:start position:0% +example uh it the max flow equal Min cut +can be expressed in a really in a + + align:start position:0% +can be expressed in a really in a + + + align:start position:0% +can be expressed in a really in a +different way the ma so what I want to + + align:start position:0% +different way the ma so what I want to + + + align:start position:0% +different way the ma so what I want to +do is restate this for the special case + + align:start position:0% +do is restate this for the special case + + + align:start position:0% +do is restate this for the special case +here as the + + align:start position:0% +here as the + + + align:start position:0% +here as the +maximum number of disjoint + + align:start position:0% + + + + align:start position:0% + +pass S2 s Prime source to sync so + + align:start position:0% +pass S2 s Prime source to sync so + + + align:start position:0% +pass S2 s Prime source to sync so +there's an example four disjoint paths + + align:start position:0% +there's an example four disjoint paths + + + align:start position:0% +there's an example four disjoint paths +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +one so I'm looking for how many + + align:start position:0% +one so I'm looking for how many + + + align:start position:0% +one so I'm looking for how many +independent paths go from here to here + + align:start position:0% +independent paths go from here to here + + + align:start position:0% +independent paths go from here to here +and it's equal to this the capacity + + align:start position:0% +and it's equal to this the capacity + + + align:start position:0% +and it's equal to this the capacity +across the cut and I would like to find + + align:start position:0% +across the cut and I would like to find + + + align:start position:0% +across the cut and I would like to find +a different uh set of words for that uh + + align:start position:0% +a different uh set of words for that uh + + + align:start position:0% +a different uh set of words for that uh +so what happen this cut suppose I + + align:start position:0% +so what happen this cut suppose I + + + align:start position:0% +so what happen this cut suppose I +actually make such a cut so I'll + + align:start position:0% +actually make such a cut so I'll + + + align:start position:0% +actually make such a cut so I'll +actually use the Eraser to to cut the + + align:start position:0% +actually use the Eraser to to cut the + + + align:start position:0% +actually use the Eraser to to cut the +the uh Network so what does a cut mean + + align:start position:0% +the uh Network so what does a cut mean + + + align:start position:0% +the uh Network so what does a cut mean +it's a it's a a separation of the nodes + + align:start position:0% +it's a it's a a separation of the nodes + + + align:start position:0% +it's a it's a a separation of the nodes +into one group with the source and + + align:start position:0% +into one group with the source and + + + align:start position:0% +into one group with the source and +another group with a sync well sorry + + align:start position:0% +another group with a sync well sorry + + + align:start position:0% +another group with a sync well sorry +that in this example the group with a + + align:start position:0% +that in this example the group with a + + + align:start position:0% +that in this example the group with a +sync is only the sync but nevertheless + + align:start position:0% +sync is only the sync but nevertheless + + + align:start position:0% +sync is only the sync but nevertheless +that's that's a cut and what's what has + + align:start position:0% +that's that's a cut and what's what has + + + align:start position:0% +that's that's a cut and what's what has +that cut + + align:start position:0% +that cut + + + align:start position:0% +that cut +done that cut has separated the source + + align:start position:0% +done that cut has separated the source + + + align:start position:0% +done that cut has separated the source +from the sink it's it's literally cut + + align:start position:0% +from the sink it's it's literally cut + + + align:start position:0% +from the sink it's it's literally cut +the two apart so + + align:start position:0% +the two apart so + + + align:start position:0% +the two apart so +the and the capacity of course is the + + align:start position:0% +the and the capacity of course is the + + + align:start position:0% +the and the capacity of course is the +the across the cut is the number + + align:start position:0% +the across the cut is the number + + + align:start position:0% +the across the cut is the number +of times we clipped an edge so here + + align:start position:0% +of times we clipped an edge so here + + + align:start position:0% +of times we clipped an edge so here +here's what I'm trying to to say the + + align:start position:0% +here's what I'm trying to to say the + + + align:start position:0% +here's what I'm trying to to say the +maximum number of disjoint paths that + + align:start position:0% +maximum number of disjoint paths that + + + align:start position:0% +maximum number of disjoint paths that +measured how much flow we could do + + align:start position:0% +measured how much flow we could do + + + align:start position:0% +measured how much flow we could do +equals the minimum + + align:start position:0% +equals the minimum + + + align:start position:0% +equals the minimum +number of cut of cut of cut + + align:start position:0% + + + + align:start position:0% + +edges + + align:start position:0% +edges + + + align:start position:0% +edges +to + + align:start position:0% +to + + + align:start position:0% +to +split may I use it use a strong verb + + align:start position:0% +split may I use it use a strong verb + + + align:start position:0% +split may I use it use a strong verb +there to split s + + align:start position:0% +there to split s + + + align:start position:0% +there to split s +from S Prime the minimum number number + + align:start position:0% +from S Prime the minimum number number + + + align:start position:0% +from S Prime the minimum number number +of edges that it took to to to + + align:start position:0% +of edges that it took to to to + + + align:start position:0% +of edges that it took to to to +uh uh separate this from this you you + + align:start position:0% +uh uh separate this from this you you + + + align:start position:0% +uh uh separate this from this you you +see that that this is a a restatement + + align:start position:0% +see that that this is a a restatement + + + align:start position:0% +see that that this is a a restatement +and maybe we could think why why I mean + + align:start position:0% +and maybe we could think why why I mean + + + align:start position:0% +and maybe we could think why why I mean +this is as + + align:start position:0% +this is as + + + align:start position:0% +this is as +usual we should see weak Duell so what + + align:start position:0% +usual we should see weak Duell so what + + + align:start position:0% +usual we should see weak Duell so what +would what did weak Duality mean weak + + align:start position:0% +would what did weak Duality mean weak + + + align:start position:0% +would what did weak Duality mean weak +Duality which was usually the easy thing + + align:start position:0% +Duality which was usually the easy thing + + + align:start position:0% +Duality which was usually the easy thing +to to to to see so if I just made + + align:start position:0% +to to to to see so if I just made + + + align:start position:0% +to to to to see so if I just made +suppose I had just made this + + align:start position:0% +suppose I had just made this + + + align:start position:0% +suppose I had just made this +statement that I draw a network and I + + align:start position:0% +statement that I draw a network and I + + + align:start position:0% +statement that I draw a network and I +look at how many separate paths there + + align:start position:0% +look at how many separate paths there + + + align:start position:0% +look at how many separate paths there +are that don't don't share any edges + + align:start position:0% +are that don't don't share any edges + + + align:start position:0% +are that don't don't share any edges +that's what disjoint means from source + + align:start position:0% +that's what disjoint means from source + + + align:start position:0% +that's what disjoint means from source +to sync how many + + align:start position:0% +to sync how many + + + align:start position:0% +to sync how many +paths uh and I looked at the minimum + + align:start position:0% +paths uh and I looked at the minimum + + + align:start position:0% +paths uh and I looked at the minimum +number of edges of cuts that I had to + + align:start position:0% +number of edges of cuts that I had to + + + align:start position:0% +number of edges of cuts that I had to +make to separate the two now it should + + align:start position:0% +make to separate the two now it should + + + align:start position:0% +make to separate the two now it should +weak should be maximum less or equal + + align:start position:0% +weak should be maximum less or equal + + + align:start position:0% +weak should be maximum less or equal +minimum should be easy and remember it's + + align:start position:0% +minimum should be easy and remember it's + + + align:start position:0% +minimum should be easy and remember it's +slightly strange that it it's that + + align:start position:0% +slightly strange that it it's that + + + align:start position:0% +slightly strange that it it's that +direction that's easy of course it's the + + align:start position:0% +direction that's easy of course it's the + + + align:start position:0% +direction that's easy of course it's the +maximum of one thing and the minimum of + + align:start position:0% +maximum of one thing and the minimum of + + + align:start position:0% +maximum of one thing and the minimum of +another why is that easy how do I know + + align:start position:0% +another why is that easy how do I know + + + align:start position:0% +another why is that easy how do I know +that + + align:start position:0% +that + + + align:start position:0% +that +um that if I + + align:start position:0% + + + + align:start position:0% + +have uh the minimum number of edges to + + align:start position:0% +have uh the minimum number of edges to + + + align:start position:0% +have uh the minimum number of edges to +to if I find it if I find some edges + + align:start position:0% +to if I find it if I find some edges + + + align:start position:0% +to if I find it if I find some edges +that split yeah H how do I know that if + + align:start position:0% +that split yeah H how do I know that if + + + align:start position:0% +that split yeah H how do I know that if +I if I find any + + align:start position:0% +I if I find any + + + align:start position:0% +I if I find any +cut any any any bunch of edges I could + + align:start position:0% +cut any any any bunch of edges I could + + + align:start position:0% +cut any any any bunch of edges I could +snip through that would separate Source + + align:start position:0% +snip through that would separate Source + + + align:start position:0% +snip through that would separate Source +from sync and I count those edges and I + + align:start position:0% +from sync and I count those edges and I + + + align:start position:0% +from sync and I count those edges and I +get K how do I know that the number of + + align:start position:0% +get K how do I know that the number of + + + align:start position:0% +get K how do I know that the number of +PA can't be more than + + align:start position:0% + + + + align:start position:0% + +K yeah yeah if if exactly if each Edge + + align:start position:0% +K yeah yeah if if exactly if each Edge + + + align:start position:0% +K yeah yeah if if exactly if each Edge +if uh if I manage to cut the thing with + + align:start position:0% +if uh if I manage to cut the thing with + + + align:start position:0% +if uh if I manage to cut the thing with +k + + align:start position:0% + + + + align:start position:0% + +then there couldn't be more than K + + align:start position:0% +then there couldn't be more than K + + + align:start position:0% +then there couldn't be more than K +disjoint paths because then I wouldn't + + align:start position:0% +disjoint paths because then I wouldn't + + + align:start position:0% +disjoint paths because then I wouldn't +have cut one of + + align:start position:0% +have cut one of + + + align:start position:0% +have cut one of +them let let me say that again just easy + + align:start position:0% +them let let me say that again just easy + + + align:start position:0% +them let let me say that again just easy +uh suppose + + align:start position:0% + + + + align:start position:0% + +suppose K + + align:start position:0% +suppose K + + + align:start position:0% +suppose K +Cuts + + align:start position:0% +Cuts + + + align:start position:0% +Cuts +split s from S + + align:start position:0% +split s from S + + + align:start position:0% +split s from S +Prime then can't + + align:start position:0% +Prime then can't + + + align:start position:0% +Prime then can't +be + + align:start position:0% +be + + + align:start position:0% +be +more can't be greater than + + align:start position:0% +more can't be greater than + + + align:start position:0% +more can't be greater than +K disjoint + + align:start position:0% + + + + align:start position:0% + +paths because if there were more than K + + align:start position:0% +paths because if there were more than K + + + align:start position:0% +paths because if there were more than K +disjoint paths then I didn't cut them + + align:start position:0% +disjoint paths then I didn't cut them + + + align:start position:0% +disjoint paths then I didn't cut them +all and then I haven't separated the + + align:start position:0% +all and then I haven't separated the + + + align:start position:0% +all and then I haven't separated the +source from the sink so that that would + + align:start position:0% +source from the sink so that that would + + + align:start position:0% +source from the sink so that that would +be the reasoning that I take any cut + + align:start position:0% +be the reasoning that I take any cut + + + align:start position:0% +be the reasoning that I take any cut +that + + align:start position:0% +that + + + align:start position:0% +that +works I say okay maybe it took k + + align:start position:0% +works I say okay maybe it took k + + + align:start position:0% +works I say okay maybe it took k +a separate edges to clip but then the + + align:start position:0% +a separate edges to clip but then the + + + align:start position:0% +a separate edges to clip but then the +number of disjoint paths couldn't be + + align:start position:0% +number of disjoint paths couldn't be + + + align:start position:0% +number of disjoint paths couldn't be +larger than K because then if it were + + align:start position:0% +larger than K because then if it were + + + align:start position:0% +larger than K because then if it were +one of those paths isn't getting cut and + + align:start position:0% +one of those paths isn't getting cut and + + + align:start position:0% +one of those paths isn't getting cut and +and uh uh we haven't we haven't + + align:start position:0% +and uh uh we haven't we haven't + + + align:start position:0% +and uh uh we haven't we haven't +separated s from S Prime so that that + + align:start position:0% +separated s from S Prime so that that + + + align:start position:0% +separated s from S Prime so that that +says that any any cut that's + + align:start position:0% +says that any any cut that's + + + align:start position:0% +says that any any cut that's +acceptable is large is at least as large + + align:start position:0% +acceptable is large is at least as large + + + align:start position:0% +acceptable is large is at least as large +as any count of disjoint paths so we + + align:start position:0% +as any count of disjoint paths so we + + + align:start position:0% +as any count of disjoint paths so we +increase the count of disjoint paths up + + align:start position:0% +increase the count of disjoint paths up + + + align:start position:0% +increase the count of disjoint paths up +to its maximum we decrease the number of + + align:start position:0% +to its maximum we decrease the number of + + + align:start position:0% +to its maximum we decrease the number of +cuts to the do the best cutting we can + + align:start position:0% +cuts to the do the best cutting we can + + + align:start position:0% +cuts to the do the best cutting we can +and we have less or equal and the point + + align:start position:0% +and we have less or equal and the point + + + align:start position:0% +and we have less or equal and the point +is we actually have equal and maybe + + align:start position:0% +is we actually have equal and maybe + + + align:start position:0% +is we actually have equal and maybe +here's a way to here's a proof of + + align:start position:0% +here's a way to here's a proof of + + + align:start position:0% +here's a way to here's a proof of +equal + + align:start position:0% +equal + + + align:start position:0% +equal +suppose we have uh well the idea of the + + align:start position:0% +suppose we have uh well the idea of the + + + align:start position:0% +suppose we have uh well the idea of the +proof is that if if uh um that suppose + + align:start position:0% +proof is that if if uh um that suppose + + + align:start position:0% +proof is that if if uh um that suppose +we have a maximum flow yeah I I um this + + align:start position:0% +we have a maximum flow yeah I I um this + + + align:start position:0% +we have a maximum flow yeah I I um this +is in the book and and it's hard to take + + align:start position:0% +is in the book and and it's hard to take + + + align:start position:0% +is in the book and and it's hard to take +in verbally but if we had a maximum flow + + align:start position:0% +in verbally but if we had a maximum flow + + + align:start position:0% +in verbally but if we had a maximum flow +suppose we had the flow as large as + + align:start position:0% +suppose we had the flow as large as + + + align:start position:0% +suppose we had the flow as large as +possible + + align:start position:0% +possible + + + align:start position:0% +possible +then I want to see why some cut of that + + align:start position:0% +then I want to see why some cut of that + + + align:start position:0% +then I want to see why some cut of that +size is holding us up so we have a Max a + + align:start position:0% +size is holding us up so we have a Max a + + + align:start position:0% +size is holding us up so we have a Max a +flow as big as possible then + + align:start position:0% +flow as big as possible then + + + align:start position:0% +flow as big as possible then +I keep with s some edges might some some + + align:start position:0% +I keep with s some edges might some some + + + align:start position:0% +I keep with s some edges might some some +with s some edges I might be able to + + align:start position:0% +with s some edges I might be able to + + + align:start position:0% +with s some edges I might be able to +send more + + align:start position:0% +send more + + + align:start position:0% +send more +to some uh along some edges I might be + + align:start position:0% +to some uh along some edges I might be + + + align:start position:0% +to some uh along some edges I might be +able to send more for example along that + + align:start position:0% +able to send more for example along that + + + align:start position:0% +able to send more for example along that +Ed Edge I could send + + align:start position:0% +Ed Edge I could send + + + align:start position:0% +Ed Edge I could send +more ha that's interesting okay now I'm + + align:start position:0% +more ha that's interesting okay now I'm + + + align:start position:0% +more ha that's interesting okay now I'm +going to I may find another cut here so + + align:start position:0% +going to I may find another cut here so + + + align:start position:0% +going to I may find another cut here so +I I keep I group with the S all the + + align:start position:0% +I I keep I group with the S all the + + + align:start position:0% +I I keep I group with the S all the +nodes to which I could still send one + + align:start position:0% +nodes to which I could still send one + + + align:start position:0% +nodes to which I could still send one +more okay let me see I need I'll use + + align:start position:0% +more okay let me see I need I'll use + + + align:start position:0% +more okay let me see I need I'll use +this so with this I keep th this note + + align:start position:0% +this so with this I keep th this note + + + align:start position:0% +this so with this I keep th this note +because I could still send one more to + + align:start position:0% + + + + align:start position:0% + +that who and then oh yeah this is going + + align:start position:0% +that who and then oh yeah this is going + + + align:start position:0% +that who and then oh yeah this is going +to be tricky because I could s now send + + align:start position:0% +to be tricky because I could s now send + + + align:start position:0% +to be tricky because I could s now send +backwards on this Edge so having sent + + align:start position:0% +backwards on this Edge so having sent + + + align:start position:0% +backwards on this Edge so having sent +these forward I could sent one backwards + + align:start position:0% +these forward I could sent one backwards + + + align:start position:0% +these forward I could sent one backwards +I think I'm not going to get into this + + align:start position:0% +I think I'm not going to get into this + + + align:start position:0% +I think I'm not going to get into this +uh uh uh because I don't want the whole + + align:start position:0% +uh uh uh because I don't want the whole + + + align:start position:0% +uh uh uh because I don't want the whole +lecture to be this rather specific topic + + align:start position:0% +lecture to be this rather specific topic + + + align:start position:0% +lecture to be this rather specific topic +what I wanted my my point is that the we + + align:start position:0% +what I wanted my my point is that the we + + + align:start position:0% +what I wanted my my point is that the we +have these + + align:start position:0% +have these + + + align:start position:0% +have these +uh + + align:start position:0% +uh + + + align:start position:0% +uh +special uh dualities for some special + + align:start position:0% +special uh dualities for some special + + + align:start position:0% +special uh dualities for some special +network + + align:start position:0% +network + + + align:start position:0% +network +problems and that they are special cases + + align:start position:0% +problems and that they are special cases + + + align:start position:0% +problems and that they are special cases +of linear programming I mean what are + + align:start position:0% +of linear programming I mean what are + + + align:start position:0% +of linear programming I mean what are +the equations yeah so here is one final + + align:start position:0% +the equations yeah so here is one final + + + align:start position:0% +the equations yeah so here is one final +question on this what are the equations + + align:start position:0% +question on this what are the equations + + + align:start position:0% +question on this what are the equations +that govern a flow I'm trying to + + align:start position:0% +that govern a flow I'm trying to + + + align:start position:0% +that govern a flow I'm trying to +maximize a + + align:start position:0% +maximize a + + + align:start position:0% +maximize a +flow + + align:start position:0% +flow + + + align:start position:0% +flow +what are the equations that govern a + + align:start position:0% +what are the equations that govern a + + + align:start position:0% +what are the equations that govern a +flow I I want to fit it into linear + + align:start position:0% +flow I I want to fit it into linear + + + align:start position:0% +flow I I want to fit it into linear +programming I want to maximize the flow + + align:start position:0% +programming I want to maximize the flow + + + align:start position:0% +programming I want to maximize the flow +so I have my unknowns are the flow along + + align:start position:0% +so I have my unknowns are the flow along + + + align:start position:0% +so I have my unknowns are the flow along +every + + align:start position:0% +every + + + align:start position:0% +every +Edge then I have some inequalities and I + + align:start position:0% +Edge then I have some inequalities and I + + + align:start position:0% +Edge then I have some inequalities and I +have some equations and if you tell me + + align:start position:0% +have some equations and if you tell me + + + align:start position:0% +have some equations and if you tell me +what those so so I'm I've I've so what + + align:start position:0% +what those so so I'm I've I've so what + + + align:start position:0% +what those so so I'm I've I've so what +what describes an okay flow so so so so + + align:start position:0% +what describes an okay flow so so so so + + + align:start position:0% +what describes an okay flow so so so so +Ma mat to match to match linear + + align:start position:0% +Ma mat to match to match linear + + + align:start position:0% +Ma mat to match to match linear +programming I want to ask you what are + + align:start position:0% +programming I want to ask you what are + + + align:start position:0% +programming I want to ask you what are +the what are the + + align:start position:0% +the what are the + + + align:start position:0% +the what are the +inequalities for a flow so I so I'll + + align:start position:0% +inequalities for a flow so I so I'll + + + align:start position:0% +inequalities for a flow so I so I'll +maximize a + + align:start position:0% +maximize a + + + align:start position:0% +maximize a +flow what are the + + align:start position:0% +flow what are the + + + align:start position:0% +flow what are the +inequalities and what are the + + align:start position:0% +inequalities and what are the + + + align:start position:0% +inequalities and what are the +equations what I mean a flow is is um + + align:start position:0% +equations what I mean a flow is is um + + + align:start position:0% +equations what I mean a flow is is um +the the what are the unknowns here the + + align:start position:0% +the the what are the unknowns here the + + + align:start position:0% +the the what are the unknowns here the +unknowns are let me say what the + + align:start position:0% +unknowns are let me say what the + + + align:start position:0% +unknowns are let me say what the +unknowns are uh x i j is the flow + + align:start position:0% +unknowns are uh x i j is the flow + + + align:start position:0% +unknowns are uh x i j is the flow +from uh I to + + align:start position:0% +from uh I to + + + align:start position:0% +from uh I to +J okay so do you remember that in linear + + align:start position:0% +J okay so do you remember that in linear + + + align:start position:0% +J okay so do you remember that in linear +programming you're maximizing something + + align:start position:0% +programming you're maximizing something + + + align:start position:0% +programming you're maximizing something +but you have certain inequalities now + + align:start position:0% +but you have certain inequalities now + + + align:start position:0% +but you have certain inequalities now +what were the inequalities in this in + + align:start position:0% +what were the inequalities in this in + + + align:start position:0% +what were the inequalities in this in +this flow problem the inequalities were + + align:start position:0% +this flow problem the inequalities were + + + align:start position:0% +this flow problem the inequalities were +that the + + align:start position:0% +that the + + + align:start position:0% +that the +flow couldn't exceed the capacity we we + + align:start position:0% +flow couldn't exceed the capacity we we + + + align:start position:0% +flow couldn't exceed the capacity we we +put a capacity of five seven nine one + + align:start position:0% +put a capacity of five seven nine one + + + align:start position:0% +put a capacity of five seven nine one +Whatever on those edges so on every Edge + + align:start position:0% +Whatever on those edges so on every Edge + + + align:start position:0% +Whatever on those edges so on every Edge +there was a upper bound and now I want + + align:start position:0% +there was a upper bound and now I want + + + align:start position:0% +there was a upper bound and now I want +to say what are the equations that flows + + align:start position:0% +to say what are the equations that flows + + + align:start position:0% +to say what are the equations that flows +have to + + align:start position:0% +have to + + + align:start position:0% +have to +satisfy what what's the + + align:start position:0% +satisfy what what's the + + + align:start position:0% +satisfy what what's the +equation I claim that at every node + + align:start position:0% +equation I claim that at every node + + + align:start position:0% +equation I claim that at every node +we've got an + + align:start position:0% +we've got an + + + align:start position:0% +we've got an +equation at + + align:start position:0% +equation at + + + align:start position:0% +equation at +every at every interior node every node + + align:start position:0% +every at every interior node every node + + + align:start position:0% +every at every interior node every node +other than SNS Prime I have an equation + + align:start position:0% +other than SNS Prime I have an equation + + + align:start position:0% +other than SNS Prime I have an equation +and and what is + + align:start position:0% +and and what is + + + align:start position:0% +and and what is +it it's Kirk's law right Kirk Hof's law + + align:start position:0% +it it's Kirk's law right Kirk Hof's law + + + align:start position:0% +it it's Kirk's law right Kirk Hof's law +so we have the the equations are Kirk + + align:start position:0% +so we have the the equations are Kirk + + + align:start position:0% +so we have the the equations are Kirk +off's current law that's that's my + + align:start position:0% +off's current law that's that's my + + + align:start position:0% +off's current law that's that's my +little point that that we we're coming + + align:start position:0% +little point that that we we're coming + + + align:start position:0% +little point that that we we're coming +around again to the to the uh most + + align:start position:0% +around again to the to the uh most + + + align:start position:0% +around again to the to the uh most +fundamental most fundamental equation + + align:start position:0% +fundamental most fundamental equation + + + align:start position:0% +fundamental most fundamental equation +in Applied Mathematics I I guess I dare + + align:start position:0% +in Applied Mathematics I I guess I dare + + + align:start position:0% +in Applied Mathematics I I guess I dare +say that + + align:start position:0% +say that + + + align:start position:0% +say that +um if you're using current law then you + + align:start position:0% +um if you're using current law then you + + + align:start position:0% +um if you're using current law then you +have to allow negative + + align:start position:0% +have to allow negative + + + align:start position:0% +have to allow negative +flows how does that change if I well + + align:start position:0% +flows how does that change if I well + + + align:start position:0% +flows how does that change if I well +let's see uh so I'm interpreting Kirk + + align:start position:0% +let's see uh so I'm interpreting Kirk + + + align:start position:0% +let's see uh so I'm interpreting Kirk +off's current law as at every node the + + align:start position:0% +off's current law as at every node the + + + align:start position:0% +off's current law as at every node the +flow in equals the flow out you're right + + align:start position:0% +flow in equals the flow out you're right + + + align:start position:0% +flow in equals the flow out you're right +so so there'll be some pluses and + + align:start position:0% +so so there'll be some pluses and + + + align:start position:0% +so so there'll be some pluses and +minuses doesn't that change your + + align:start position:0% +minuses doesn't that change your + + + align:start position:0% +minuses doesn't that change your +inequality so now you have a nonlinear + + align:start position:0% +inequality so now you have a nonlinear + + + align:start position:0% +inequality so now you have a nonlinear +inequality the magnitude of XI has to be + + align:start position:0% +inequality the magnitude of XI has to be + + + align:start position:0% +inequality the magnitude of XI has to be +less than C well let I'll just I'm not + + align:start position:0% +less than C well let I'll just I'm not + + + align:start position:0% +less than C well let I'll just I'm not +even sure in this instance but but + + align:start position:0% +even sure in this instance but but + + + align:start position:0% +even sure in this instance but but +suppose we had what looks like a + + align:start position:0% +suppose we had what looks like a + + + align:start position:0% +suppose we had what looks like a +nonlinear + + align:start position:0% +nonlinear + + + align:start position:0% +nonlinear +inequality turn it into linear + + align:start position:0% +inequality turn it into linear + + + align:start position:0% +inequality turn it into linear +inequalities just that's a very good + + align:start position:0% +inequalities just that's a very good + + + align:start position:0% +inequalities just that's a very good +example of how flexible this is how + + align:start position:0% +example of how flexible this is how + + + align:start position:0% +example of how flexible this is how +could I turn that which certainly looks + + align:start position:0% +could I turn that which certainly looks + + + align:start position:0% +could I turn that which certainly looks +nonlinear into linear + + align:start position:0% +nonlinear into linear + + + align:start position:0% +nonlinear into linear +inequalities double the number I could + + align:start position:0% +inequalities double the number I could + + + align:start position:0% +inequalities double the number I could +double the number right I could leave it + + align:start position:0% +double the number right I could leave it + + + align:start position:0% +double the number right I could leave it +as XI J and add to that minus XI J is + + align:start position:0% +as XI J and add to that minus XI J is + + + align:start position:0% +as XI J and add to that minus XI J is +what would it + + align:start position:0% +what would it + + + align:start position:0% +what would it +be greater than or I forgotten minus CI + + align:start position:0% +be greater than or I forgotten minus CI + + + align:start position:0% +be greater than or I forgotten minus CI +J what what would what would it be if I + + align:start position:0% +J what what would what would it be if I + + + align:start position:0% +J what what would what would it be if I +want if I want XI to be small maybe it + + align:start position:0% +want if I want XI to be small maybe it + + + align:start position:0% +want if I want XI to be small maybe it +would be that would + + align:start position:0% +would be that would + + + align:start position:0% +would be that would +it right and then uh yeah yeah uh so or + + align:start position:0% +it right and then uh yeah yeah uh so or + + + align:start position:0% +it right and then uh yeah yeah uh so or +is that no is + + align:start position:0% +is that no is + + + align:start position:0% +is that no is +it is that right I think you need to I + + align:start position:0% +it is that right I think you need to I + + + align:start position:0% +it is that right I think you need to I +I I don't get rid of that minus no on C + + align:start position:0% +I I don't get rid of that minus no on C + + + align:start position:0% +I I don't get rid of that minus no on C +on C + + align:start position:0% +on C + + + align:start position:0% +on C +maybe minus XI greater equal C J yeah + + align:start position:0% +maybe minus XI greater equal C J yeah + + + align:start position:0% +maybe minus XI greater equal C J yeah +okay okay my point is we could do it and + + align:start position:0% +okay okay my point is we could do it and + + + align:start position:0% +okay okay my point is we could do it and +we'd still have linear programming uh + + align:start position:0% +we'd still have linear programming uh + + + align:start position:0% +we'd still have linear programming uh +double the number of uh constraints but + + align:start position:0% +double the number of uh constraints but + + + align:start position:0% +double the number of uh constraints but +we we'll handle those and the point I + + align:start position:0% +we we'll handle those and the point I + + + align:start position:0% +we we'll handle those and the point I +wanted to make was this key equation + + align:start position:0% +wanted to make was this key equation + + + align:start position:0% +wanted to make was this key equation +kof's current law I don't mean to say + + align:start position:0% +kof's current law I don't mean to say + + + align:start position:0% +kof's current law I don't mean to say +that when we look at all of Applied + + align:start position:0% +that when we look at all of Applied + + + align:start position:0% +that when we look at all of Applied +Mathematics kiru's current law jumps out + + align:start position:0% +Mathematics kiru's current law jumps out + + + align:start position:0% +Mathematics kiru's current law jumps out +uniquely except what jumps out is + + align:start position:0% +uniquely except what jumps out is + + + align:start position:0% +uniquely except what jumps out is +balance + + align:start position:0% +balance + + + align:start position:0% +balance +equations conservation equations in + + align:start position:0% +equations conservation equations in + + + align:start position:0% +equations conservation equations in +equals + + align:start position:0% +equals + + + align:start position:0% +equals +out plus possible + + align:start position:0% +out plus possible + + + align:start position:0% +out plus possible +sources that that's that that so much of + + align:start position:0% +sources that that's that that so much of + + + align:start position:0% +sources that that's that that so much of +Applied Mathematics is that's one of the + + align:start position:0% +Applied Mathematics is that's one of the + + + align:start position:0% +Applied Mathematics is that's one of the +equations to look for then there'll be + + align:start position:0% +equations to look for then there'll be + + + align:start position:0% +equations to look for then there'll be +the equation that describes the + + align:start position:0% +the equation that describes the + + + align:start position:0% +the equation that describes the +particular + + align:start position:0% +particular + + + align:start position:0% +particular +uh the the physics of the problem you + + align:start position:0% +uh the the physics of the problem you + + + align:start position:0% +uh the the physics of the problem you +know what what is the flow how does the + + align:start position:0% +know what what is the flow how does the + + + align:start position:0% +know what what is the flow how does the +flow connect to potentials or something + + align:start position:0% +flow connect to potentials or something + + + align:start position:0% +flow connect to potentials or something +but that that balance equation is always + + align:start position:0% +but that that balance equation is always + + + align:start position:0% +but that that balance equation is always +there okay so that's I I'm I'm going to + + align:start position:0% +there okay so that's I I'm I'm going to + + + align:start position:0% +there okay so that's I I'm I'm going to +stop there with a hope + + align:start position:0% +stop there with a hope + + + align:start position:0% +stop there with a hope +well with a hope that + + align:start position:0% +well with a hope that + + + align:start position:0% +well with a hope that +you find some of those um uh ex special + + align:start position:0% +you find some of those um uh ex special + + + align:start position:0% +you find some of those um uh ex special +cases appealing and then also with the + + align:start position:0% +cases appealing and then also with the + + + align:start position:0% +cases appealing and then also with the +hope that you'll enjoy Game + + align:start position:0% +hope that you'll enjoy Game + + + align:start position:0% +hope that you'll enjoy Game +Theory but I'm really Keen to tell you + + align:start position:0% +Theory but I'm really Keen to tell you + + + align:start position:0% +Theory but I'm really Keen to tell you +about if you'll help me again as you did + + align:start position:0% +about if you'll help me again as you did + + + align:start position:0% +about if you'll help me again as you did +last week you kept me going through this + + align:start position:0% +last week you kept me going through this + + + align:start position:0% +last week you kept me going through this +question let me remind you what that + + align:start position:0% +question let me remind you what that + + + align:start position:0% +question let me remind you what that +question was the question + + align:start position:0% +question was the question + + + align:start position:0% +question was the question +was uh so let + + align:start position:0% +was uh so let + + + align:start position:0% +was uh so let +me put the question here the question + + align:start position:0% +me put the question here the question + + + align:start position:0% +me put the question here the question +was I have a + + align:start position:0% +was I have a + + + align:start position:0% +was I have a +matrix and I'm wondering about which + + align:start position:0% +matrix and I'm wondering about which + + + align:start position:0% +matrix and I'm wondering about which +positions could I give arbitrary + + align:start position:0% +positions could I give arbitrary + + + align:start position:0% +positions could I give arbitrary +values and then complete the Matrix to + + align:start position:0% +values and then complete the Matrix to + + + align:start position:0% +values and then complete the Matrix to +have rank one so this is my so I'm + + align:start position:0% +have rank one so this is my so I'm + + + align:start position:0% +have rank one so this is my so I'm +giving any nonzero values and let's take + + align:start position:0% +giving any nonzero values and let's take + + + align:start position:0% +giving any nonzero values and let's take +an example could let's let me take the + + align:start position:0% +an example could let's let me take the + + + align:start position:0% +an example could let's let me take the +example that I had last time well let me + + align:start position:0% +example that I had last time well let me + + + align:start position:0% +example that I had last time well let me +take this + + align:start position:0% + + + + align:start position:0% + +example could + + align:start position:0% +example could + + + align:start position:0% +example could +I give any any nonzero value values in + + align:start position:0% +I give any any nonzero value values in + + + align:start position:0% +I give any any nonzero value values in +those six + + align:start position:0% +those six + + + align:start position:0% +those six +places and aim + + align:start position:0% +places and aim + + + align:start position:0% +places and aim +for complete + + align:start position:0% + + + + align:start position:0% + +to rank + + align:start position:0% + + + + align:start position:0% + +one is that possible and your answer is + + align:start position:0% +one is that possible and your answer is + + + align:start position:0% +one is that possible and your answer is +no because we have here if if rank one + + align:start position:0% +no because we have here if if rank one + + + align:start position:0% +no because we have here if if rank one +will mean what will rank one mean it'll + + align:start position:0% +will mean what will rank one mean it'll + + + align:start position:0% +will mean what will rank one mean it'll +mean that all 2x two determinant + + align:start position:0% +mean that all 2x two determinant + + + align:start position:0% +mean that all 2x two determinant +are + + align:start position:0% +are + + + align:start position:0% +are +zero and that won't be true here so I + + align:start position:0% +zero and that won't be true here so I + + + align:start position:0% +zero and that won't be true here so I +better take one of those out there or + + align:start position:0% +better take one of those out there or + + + align:start position:0% +better take one of those out there or +let me let me take let me make it a + + align:start position:0% +let me let me take let me make it a + + + align:start position:0% +let me let me take let me make it a +little L obvious by taking that one out + + align:start position:0% +little L obvious by taking that one out + + + align:start position:0% +little L obvious by taking that one out +could I now + + align:start position:0% +could I now + + + align:start position:0% +could I now +complete so now I'm I'm I'm less + + align:start position:0% +complete so now I'm I'm I'm less + + + align:start position:0% +complete so now I'm I'm I'm less +ambitious I'm I'm putting in five + + align:start position:0% +ambitious I'm I'm putting in five + + + align:start position:0% +ambitious I'm I'm putting in five +entries and I'm putting them in this + + align:start position:0% +entries and I'm putting them in this + + + align:start position:0% +entries and I'm putting them in this +position and could I now complete those + + align:start position:0% +position and could I now complete those + + + align:start position:0% +position and could I now complete those +to complete this to rank one and the + + align:start position:0% +to complete this to rank one and the + + + align:start position:0% +to complete this to rank one and the +answer is yes right I could this this + + align:start position:0% +answer is yes right I could this this + + + align:start position:0% +answer is yes right I could this this +would this 2x two would now tell me what + + align:start position:0% +would this 2x two would now tell me what + + + align:start position:0% +would this 2x two would now tell me what +that number had to be this 2 by two + + align:start position:0% +that number had to be this 2 by two + + + align:start position:0% +that number had to be this 2 by two +would tell me what this number had to be + + align:start position:0% +would tell me what this number had to be + + + align:start position:0% +would tell me what this number had to be +if I do it two just this 2 by two would + + align:start position:0% +if I do it two just this 2 by two would + + + align:start position:0% +if I do it two just this 2 by two would +tell me that number this 2 by two would + + align:start position:0% +tell me that number this 2 by two would + + + align:start position:0% +tell me that number this 2 by two would +tell me that number well and you might + + align:start position:0% +tell me that number well and you might + + + align:start position:0% +tell me that number well and you might +say wait a minute this two 2 by two told + + align:start position:0% +say wait a minute this two 2 by two told + + + align:start position:0% +say wait a minute this two 2 by two told +me that number also so maybe it's + + align:start position:0% +me that number also so maybe it's + + + align:start position:0% +me that number also so maybe it's +less uh uh um maybe it's + + align:start position:0% +less uh uh um maybe it's + + + align:start position:0% +less uh uh um maybe it's +uh needs a little bit more thinking so + + align:start position:0% +uh needs a little bit more thinking so + + + align:start position:0% +uh needs a little bit more thinking so +right the way I did it was not + + align:start position:0% +right the way I did it was not + + + align:start position:0% +right the way I did it was not +completely convincing because I would + + align:start position:0% +completely convincing because I would + + + align:start position:0% +completely convincing because I would +said okay do that one then do that one + + align:start position:0% +said okay do that one then do that one + + + align:start position:0% +said okay do that one then do that one +then do that one then do this one and + + align:start position:0% +then do that one then do this one and + + + align:start position:0% +then do that one then do this one and +then you say wait a minute those three + + align:start position:0% +then you say wait a minute those three + + + align:start position:0% +then you say wait a minute those three +were specified that determined that one + + align:start position:0% +were specified that determined that one + + + align:start position:0% +were specified that determined that one +so uh I would need a more convincing + + align:start position:0% +so uh I would need a more convincing + + + align:start position:0% +so uh I would need a more convincing +what would be more convincing can can + + align:start position:0% +what would be more convincing can can + + + align:start position:0% +what would be more convincing can can +you can you give me the a correct uh a + + align:start position:0% +you can you give me the a correct uh a + + + align:start position:0% +you can you give me the a correct uh a +better uh well I could go back to that + + align:start position:0% +better uh well I could go back to that + + + align:start position:0% +better uh well I could go back to that +and do it more carefully but how how do + + align:start position:0% +and do it more carefully but how how do + + + align:start position:0% +and do it more carefully but how how do +you see that that could be completed to + + align:start position:0% +you see that that could be completed to + + + align:start position:0% +you see that that could be completed to +rank + + align:start position:0% +rank + + + align:start position:0% +rank +one rank one will mean that every row is + + align:start position:0% +one rank one will mean that every row is + + + align:start position:0% +one rank one will mean that every row is +a multiple of every other + + align:start position:0% +a multiple of every other + + + align:start position:0% +a multiple of every other +rowo so right right we see that row + + align:start position:0% +rowo so right right we see that row + + + align:start position:0% +rowo so right right we see that row +already set just enough for each + + align:start position:0% +already set just enough for each + + + align:start position:0% +already set just enough for each +row not too many right yeah that's right + + align:start position:0% +row not too many right yeah that's right + + + align:start position:0% +row not too many right yeah that's right +we want to know that just enough and not + + align:start position:0% +we want to know that just enough and not + + + align:start position:0% +we want to know that just enough and not +too many okay so after playing around + + align:start position:0% +too many okay so after playing around + + + align:start position:0% +too many okay so after playing around +with examples like that the conjecture + + align:start position:0% +with examples like that the conjecture + + + align:start position:0% +with examples like that the conjecture +was that the right + + align:start position:0% +was that the right + + + align:start position:0% +was that the right +number to + + align:start position:0% +number to + + + align:start position:0% +number to +specify if this is K by + + align:start position:0% +specify if this is K by + + + align:start position:0% +specify if this is K by +K complete a k by + + align:start position:0% +K complete a k by + + + align:start position:0% +K complete a k by +K so 3x3 in this instance the right + + align:start position:0% +K so 3x3 in this instance the right + + + align:start position:0% +K so 3x3 in this instance the right +number is + + align:start position:0% +number is + + + align:start position:0% +number is +five that's our + + align:start position:0% +five that's our + + + align:start position:0% +five that's our +guess and and + + align:start position:0% +guess and and + + + align:start position:0% +guess and and +so + + align:start position:0% +so + + + align:start position:0% +so +uh the general guess was 2K minus one so + + align:start position:0% +uh the general guess was 2K minus one so + + + align:start position:0% +uh the general guess was 2K minus one so +that's what I want to prove that's what + + align:start position:0% +that's what I want to prove that's what + + + align:start position:0% +that's what I want to prove that's what +I want to prove that that that would be + + align:start position:0% +I want to prove that that that would be + + + align:start position:0% +I want to prove that that that would be +the theorem that uh it's completion rank + + align:start position:0% +the theorem that uh it's completion rank + + + align:start position:0% +the theorem that uh it's completion rank +one completion is + + align:start position:0% + + + + align:start position:0% + +possible if and only + + align:start position:0% +possible if and only + + + align:start position:0% +possible if and only +if every + + align:start position:0% +if every + + + align:start position:0% +if every +and I have to check the submatrices too + + align:start position:0% +and I have to check the submatrices too + + + align:start position:0% +and I have to check the submatrices too +every + + align:start position:0% + + + + align:start position:0% + +submatrix of every submatrix of let's + + align:start position:0% +submatrix of every submatrix of let's + + + align:start position:0% +submatrix of every submatrix of let's +say of order let me call its order K + + align:start position:0% +say of order let me call its order K + + + align:start position:0% +say of order let me call its order K +has less than or equal to 2K minus one + + align:start position:0% +has less than or equal to 2K minus one + + + align:start position:0% +has less than or equal to 2K minus one +specified + + align:start position:0% +specified + + + align:start position:0% +specified +entries specified entries and I'm going + + align:start position:0% +entries specified entries and I'm going + + + align:start position:0% +entries specified entries and I'm going +to specify them + + align:start position:0% +to specify them + + + align:start position:0% +to specify them +nonzeros so that that's that's like a + + align:start position:0% +nonzeros so that that's that's like a + + + align:start position:0% +nonzeros so that that's that's like a +hope a new theorem and and uh + + align:start position:0% +hope a new theorem and and uh + + + align:start position:0% +hope a new theorem and and uh +um + + align:start position:0% +um + + + align:start position:0% +um +uh it sort of partly happened because of + + align:start position:0% +uh it sort of partly happened because of + + + align:start position:0% +uh it sort of partly happened because of +the examples that we played with so so + + align:start position:0% +the examples that we played with so so + + + align:start position:0% +the examples that we played with so so +why so does this does this example pass + + align:start position:0% +why so does this does this example pass + + + align:start position:0% +why so does this does this example pass +that + + align:start position:0% +that + + + align:start position:0% +that +test + + align:start position:0% + + + + align:start position:0% + +yes moved it over to to where + + align:start position:0% + + + + align:start position:0% + +here the as it + + align:start position:0% +here the as it + + + align:start position:0% +here the as it +is yes but of course when I complete + + align:start position:0% +is yes but of course when I complete + + + align:start position:0% +is yes but of course when I complete +it when I complete it I I can hopefully + + align:start position:0% +it when I complete it I I can hopefully + + + align:start position:0% +it when I complete it I I can hopefully +get it to have rank one and and as you + + align:start position:0% +get it to have rank one and and as you + + + align:start position:0% +get it to have rank one and and as you +say if I looked at igen values they + + align:start position:0% +say if I looked at igen values they + + + align:start position:0% +say if I looked at igen values they +would be zero and zero and whatever that + + align:start position:0% +would be zero and zero and whatever that + + + align:start position:0% +would be zero and zero and whatever that +Trace + + align:start position:0% +Trace + + + align:start position:0% +Trace +is yeah + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +yeah I put in numbers so let me let me + + align:start position:0% +yeah I put in numbers so let me let me + + + align:start position:0% +yeah I put in numbers so let me let me +take a specific + + align:start position:0% +take a specific + + + align:start position:0% +take a specific +case can could I give and you'll see by + + align:start position:0% +case can could I give and you'll see by + + + align:start position:0% +case can could I give and you'll see by +the way I write these numbers in 1 4 7 2 + + align:start position:0% +the way I write these numbers in 1 4 7 2 + + + align:start position:0% +the way I write these numbers in 1 4 7 2 +and 11 now the question is can I + + align:start position:0% +and 11 now the question is can I + + + align:start position:0% +and 11 now the question is can I +complete that Matrix to rank one yeah + + align:start position:0% +complete that Matrix to rank one yeah + + + align:start position:0% +complete that Matrix to rank one yeah +this is very thank you for every + + align:start position:0% +this is very thank you for every + + + align:start position:0% +this is very thank you for every +question you ask improves the way I + + align:start position:0% +question you ask improves the way I + + + align:start position:0% +question you ask improves the way I +think about it so so okay so we would + + align:start position:0% +think about it so so okay so we would + + + align:start position:0% +think about it so so okay so we would +say yep we can do it uh all right I + + align:start position:0% +say yep we can do it uh all right I + + + align:start position:0% +say yep we can do it uh all right I +could do it 2 by two you know I would + + align:start position:0% +could do it 2 by two you know I would + + + align:start position:0% +could do it 2 by two you know I would +see okay what do I need there I need a + + align:start position:0% +see okay what do I need there I need a + + + align:start position:0% +see okay what do I need there I need a +half is that + + align:start position:0% +half is that + + + align:start position:0% +half is that +right and really what I need is that for + + align:start position:0% +right and really what I need is that for + + + align:start position:0% +right and really what I need is that for +that row 147 for this row to be half as + + align:start position:0% +that row 147 for this row to be half as + + + align:start position:0% +that row 147 for this row to be half as +much so this would be seven halves and + + align:start position:0% +much so this would be seven halves and + + + align:start position:0% +much so this would be seven halves and +for this row this row should be in the + + align:start position:0% +for this row this row should be in the + + + align:start position:0% +for this row this row should be in the +ratio 11 to 7 or whatever yeah sorry + + align:start position:0% +ratio 11 to 7 or whatever yeah sorry + + + align:start position:0% +ratio 11 to 7 or whatever yeah sorry +when I said arbitrary numbers I didn't + + align:start position:0% +when I said arbitrary numbers I didn't + + + align:start position:0% +when I said arbitrary numbers I didn't +mean that + + align:start position:0% +mean that + + + align:start position:0% +mean that +arbitrary uh yeah but anyway I could do + + align:start position:0% +arbitrary uh yeah but anyway I could do + + + align:start position:0% +arbitrary uh yeah but anyway I could do +it and you realize why just just to be + + align:start position:0% +it and you realize why just just to be + + + align:start position:0% +it and you realize why just just to be +sure that I can't do it for any five + + align:start position:0% +sure that I can't do it for any five + + + align:start position:0% +sure that I can't do it for any five +suppose I specify those + + align:start position:0% +suppose I specify those + + + align:start position:0% +suppose I specify those +five now I can't complete to rank one + + align:start position:0% +five now I can't complete to rank one + + + align:start position:0% +five now I can't complete to rank one +because I'm lost at the start here if + + align:start position:0% +because I'm lost at the start here if + + + align:start position:0% +because I'm lost at the start here if +I've made those arbitrary then that's a + + align:start position:0% +I've made those arbitrary then that's a + + + align:start position:0% +I've made those arbitrary then that's a +2X two that isn't determinant that isn't + + align:start position:0% +2X two that isn't determinant that isn't + + + align:start position:0% +2X two that isn't determinant that isn't +zero and no way I can fix it I I could + + align:start position:0% +zero and no way I can fix it I I could + + + align:start position:0% +zero and no way I can fix it I I could +make those numbers if if you want it + + align:start position:0% +make those numbers if if you want it + + + align:start position:0% +make those numbers if if you want it +right uh so so that's why I have + + align:start position:0% +right uh so so that's why I have + + + align:start position:0% +right uh so so that's why I have +to in the test has to go not only the + + align:start position:0% +to in the test has to go not only the + + + align:start position:0% +to in the test has to go not only the +big guy but all the smaller ones because + + align:start position:0% +big guy but all the smaller ones because + + + align:start position:0% +big guy but all the smaller ones because +if a smaller one fails my test the + + align:start position:0% +if a smaller one fails my test the + + + align:start position:0% +if a smaller one fails my test the +bigger one might still have only 2K + + align:start position:0% +bigger one might still have only 2K + + + align:start position:0% +bigger one might still have only 2K +minus one five specified entries here + + align:start position:0% +minus one five specified entries here + + + align:start position:0% +minus one five specified entries here +but the smaller if a smaller one messes + + align:start position:0% +but the smaller if a smaller one messes + + + align:start position:0% +but the smaller if a smaller one messes +up then I'm it syns me before I can I've + + align:start position:0% +up then I'm it syns me before I can I've + + + align:start position:0% +up then I'm it syns me before I can I've +got no way to save it okay so uh uh let + + align:start position:0% +got no way to save it okay so uh uh let + + + align:start position:0% +got no way to save it okay so uh uh let +me let me take a + + align:start position:0% +me let me take a + + + align:start position:0% +me let me take a +4x4 just uh so 4x4 I should be allowed + + align:start position:0% +4x4 just uh so 4x4 I should be allowed + + + align:start position:0% +4x4 just uh so 4x4 I should be allowed +seven + + align:start position:0% +seven + + + align:start position:0% +seven +entries and + + align:start position:0% +entries and + + + align:start position:0% +entries and +uh okay now here think through how + + align:start position:0% +uh okay now here think through how + + + align:start position:0% +uh okay now here think through how +suppose I have seven + + align:start position:0% +suppose I have seven + + + align:start position:0% +suppose I have seven +entries how can + + align:start position:0% +entries how can + + + align:start position:0% +entries how can +I + + align:start position:0% +I + + + align:start position:0% +I +complete how can I prove that I can + + align:start position:0% +complete how can I prove that I can + + + align:start position:0% +complete how can I prove that I can +complete so I'm I'm asking um what what + + align:start position:0% +complete so I'm I'm asking um what what + + + align:start position:0% +complete so I'm I'm asking um what what +I'm really talking about now is that + + align:start position:0% +I'm really talking about now is that + + + align:start position:0% +I'm really talking about now is that +math step from doing a bunch of examples + + align:start position:0% +math step from doing a bunch of examples + + + align:start position:0% +math step from doing a bunch of examples +and getting + + align:start position:0% +and getting + + + align:start position:0% +and getting +convinced and getting a + + align:start position:0% +convinced and getting a + + + align:start position:0% +convinced and getting a +proof that's absolutely + + align:start position:0% +proof that's absolutely + + + align:start position:0% +proof that's absolutely +convincing see what I'm trying to say + + align:start position:0% +convincing see what I'm trying to say + + + align:start position:0% +convincing see what I'm trying to say +that I now have to think seven entries + + align:start position:0% +that I now have to think seven entries + + + align:start position:0% +that I now have to think seven entries +any any seven subject to this + + align:start position:0% +any any seven subject to this + + + align:start position:0% +any any seven subject to this +constraint how can I show that it's + + align:start position:0% +constraint how can I show that it's + + + align:start position:0% +constraint how can I show that it's +possible all right can I can let me so + + align:start position:0% +possible all right can I can let me so + + + align:start position:0% +possible all right can I can let me so +actually strictly in this proof I have + + align:start position:0% +actually strictly in this proof I have + + + align:start position:0% +actually strictly in this proof I have +two directions to go but let me let me + + align:start position:0% +two directions to go but let me let me + + + align:start position:0% +two directions to go but let me let me +suppose that this test is passed and I + + align:start position:0% +suppose that this test is passed and I + + + align:start position:0% +suppose that this test is passed and I +have a 4x4 with seven entries that + + align:start position:0% +have a 4x4 with seven entries that + + + align:start position:0% +have a 4x4 with seven entries that +passes that test and I'll conclude that + + align:start position:0% +passes that test and I'll conclude that + + + align:start position:0% +passes that test and I'll conclude that +I can + + align:start position:0% +I can + + + align:start position:0% +I can +complete and then there will be another + + align:start position:0% +complete and then there will be another + + + align:start position:0% +complete and then there will be another +step of the proof that that shows that + + align:start position:0% +step of the proof that that shows that + + + align:start position:0% +step of the proof that that shows that +that condition is necessary but let's do + + align:start position:0% +that condition is necessary but let's do + + + align:start position:0% +that condition is necessary but let's do +the first one way that that's okay I've + + align:start position:0% +the first one way that that's okay I've + + + align:start position:0% +the first one way that that's okay I've +got seven + + align:start position:0% +got seven + + + align:start position:0% +got seven +entries in a 4x4 4x4 seven + + align:start position:0% +entries in a 4x4 4x4 seven + + + align:start position:0% +entries in a 4x4 4x4 seven +entries + + align:start position:0% +entries + + + align:start position:0% +entries +okay and now let's see so my here's my + + align:start position:0% +okay and now let's see so my here's my + + + align:start position:0% +okay and now let's see so my here's my +reasoning one row has to + + align:start position:0% +reasoning one row has to + + + align:start position:0% +reasoning one row has to +have and all the rows couldn't have two + + align:start position:0% +have and all the rows couldn't have two + + + align:start position:0% +have and all the rows couldn't have two +entries right right that would make + + align:start position:0% +entries right right that would make + + + align:start position:0% +entries right right that would make +eight so one row has to + + align:start position:0% +eight so one row has to + + + align:start position:0% +eight so one row has to +have no entries or one okay so I'm + + align:start position:0% +have no entries or one okay so I'm + + + align:start position:0% +have no entries or one okay so I'm +covering all cases so so so one row has + + align:start position:0% +covering all cases so so so one row has + + + align:start position:0% +covering all cases so so so one row has +to have either no entries or one entry + + align:start position:0% +to have either no entries or one entry + + + align:start position:0% +to have either no entries or one entry +right so we can reorder the rows and + + align:start position:0% +right so we can reorder the rows and + + + align:start position:0% +right so we can reorder the rows and +make it the first row in fact then we + + align:start position:0% +make it the first row in fact then we + + + align:start position:0% +make it the first row in fact then we +could reorder The Columns and make it + + align:start position:0% +could reorder The Columns and make it + + + align:start position:0% +could reorder The Columns and make it +the First Column so here's a so so up in + + align:start position:0% +the First Column so here's a so so up in + + + align:start position:0% +the First Column so here's a so so up in +the first row is only one entry and I'll + + align:start position:0% +the first row is only one entry and I'll + + + align:start position:0% +the first row is only one entry and I'll +reorder The Columns that won't change + + align:start position:0% +reorder The Columns that won't change + + + align:start position:0% +reorder The Columns that won't change +anything just to keep our our we're + + align:start position:0% +anything just to keep our our we're + + + align:start position:0% +anything just to keep our our we're +looking like that right there has to be + + align:start position:0% +looking like that right there has to be + + + align:start position:0% +looking like that right there has to be +a row with only one entry because + + align:start position:0% +a row with only one entry because + + + align:start position:0% +a row with only one entry because +there's only seven entries all + + align:start position:0% + + + + align:start position:0% + +together and four rows + + align:start position:0% +together and four rows + + + align:start position:0% +together and four rows +okay there has to be a row either with + + align:start position:0% +okay there has to be a row either with + + + align:start position:0% +okay there has to be a row either with +one or or + + align:start position:0% +one or or + + + align:start position:0% +one or or +with or there could be a row of all + + align:start position:0% +with or there could be a row of all + + + align:start position:0% +with or there could be a row of all +zeros uh with what do I mean by this + + align:start position:0% +zeros uh with what do I mean by this + + + align:start position:0% +zeros uh with what do I mean by this +zero I mean unspecified should I put U + + align:start position:0% +zero I mean unspecified should I put U + + + align:start position:0% +zero I mean unspecified should I put U +for + + align:start position:0% +for + + + align:start position:0% +for +unspecified okay you for unspecified or + + align:start position:0% +unspecified okay you for unspecified or + + + align:start position:0% +unspecified okay you for unspecified or +I could possibly + + align:start position:0% +I could possibly + + + align:start position:0% +I could possibly +have a there could be I could have seven + + align:start position:0% +have a there could be I could have seven + + + align:start position:0% +have a there could be I could have seven +in the whole thing but there would be + + align:start position:0% +in the whole thing but there would be + + + align:start position:0% +in the whole thing but there would be +but let's let's kill + + align:start position:0% +but let's let's kill + + + align:start position:0% +but let's let's kill +this possibility first here okay now now + + align:start position:0% +this possibility first here okay now now + + + align:start position:0% +this possibility first here okay now now +how how could I show now I've got seven + + align:start position:0% +how how could I show now I've got seven + + + align:start position:0% +how how could I show now I've got seven +the seven are still specified but + + align:start position:0% +the seven are still specified but + + + align:start position:0% +the seven are still specified but +they're only in three + + align:start position:0% +they're only in three + + + align:start position:0% +they're only in three +rows okay so what do you think + + align:start position:0% +rows okay so what do you think + + + align:start position:0% +rows okay so what do you think +now uh let's see oh I've got four + + align:start position:0% +now uh let's see oh I've got four + + + align:start position:0% +now uh let's see oh I've got four +columns here now the wonderful thing + + align:start position:0% +columns here now the wonderful thing + + + align:start position:0% +columns here now the wonderful thing +about linear algebra is the relation of + + align:start position:0% +about linear algebra is the relation of + + + align:start position:0% +about linear algebra is the relation of +rows to columns that's what you got to + + align:start position:0% +rows to columns that's what you got to + + + align:start position:0% +rows to columns that's what you got to +keep remembering okay so I still have + + align:start position:0% +keep remembering okay so I still have + + + align:start position:0% +keep remembering okay so I still have +four columns and I've got seven + + align:start position:0% +four columns and I've got seven + + + align:start position:0% +four columns and I've got seven +specified so again I have a column that + + align:start position:0% +specified so again I have a column that + + + align:start position:0% +specified so again I have a column that +has only + + align:start position:0% +has only + + + align:start position:0% +has only +one or or none right because there were + + align:start position:0% +one or or none right because there were + + + align:start position:0% +one or or none right because there were +four columns I've got to put seven x's + + align:start position:0% +four columns I've got to put seven x's + + + align:start position:0% +four columns I've got to put seven x's +in here some column is only going to + + align:start position:0% +in here some column is only going to + + + align:start position:0% +in here some column is only going to +have like One + + align:start position:0% +have like One + + + align:start position:0% +have like One +X and the and the other six are going to + + align:start position:0% +X and the and the other six are going to + + + align:start position:0% +X and the and the other six are going to +be in + + align:start position:0% + + + + align:start position:0% + +here okay so I claim + + align:start position:0% +here okay so I claim + + + align:start position:0% +here okay so I claim +that this totally + + align:start position:0% +that this totally + + + align:start position:0% +that this totally +VI + + align:start position:0% +VI + + + align:start position:0% +VI +that this can't happen because I'm I'm + + align:start position:0% +that this can't happen because I'm I'm + + + align:start position:0% +that this can't happen because I'm I'm +assuming this right I'm assuming + + align:start position:0% +assuming this right I'm assuming + + + align:start position:0% +assuming this right I'm assuming +this let's get the logic straight I'm + + align:start position:0% +this let's get the logic straight I'm + + + align:start position:0% +this let's get the logic straight I'm +proving that if this is true I assume + + align:start position:0% +proving that if this is true I assume + + + align:start position:0% +proving that if this is true I assume +it's true and then show + + align:start position:0% +it's true and then show + + + align:start position:0% +it's true and then show +this show this that's this is the + + align:start position:0% +this show this that's this is the + + + align:start position:0% +this show this that's this is the +direction I'm going okay so I assume + + align:start position:0% +direction I'm going okay so I assume + + + align:start position:0% +direction I'm going okay so I assume +that every not only the big Matrix the + + align:start position:0% +that every not only the big Matrix the + + + align:start position:0% +that every not only the big Matrix the +4x4 had seven nonzeros but every + + align:start position:0% +4x4 had seven nonzeros but every + + + align:start position:0% +4x4 had seven nonzeros but every +submatrix of order K didn't have more + + align:start position:0% +submatrix of order K didn't have more + + + align:start position:0% +submatrix of order K didn't have more +than 2K minus one but here I have a + + align:start position:0% +than 2K minus one but here I have a + + + align:start position:0% +than 2K minus one but here I have a +submatrix it's 3x3 and it's got six so + + align:start position:0% +submatrix it's 3x3 and it's got six so + + + align:start position:0% +submatrix it's 3x3 and it's got six so +this + + align:start position:0% +this + + + align:start position:0% +this +this that couldn't have happened let me + + align:start position:0% +this that couldn't have happened let me + + + align:start position:0% +this that couldn't have happened let me +come back to + + align:start position:0% +come back to + + + align:start position:0% +come back to +here again I'm going to shoot the same + + align:start position:0% +here again I'm going to shoot the same + + + align:start position:0% +here again I'm going to shoot the same +go the same way here um now what do I + + align:start position:0% +go the same way here um now what do I + + + align:start position:0% +go the same way here um now what do I +want to do I'd like to okay now I have + + align:start position:0% +want to do I'd like to okay now I have + + + align:start position:0% +want to do I'd like to okay now I have +one specified guy that's more reasonable + + align:start position:0% +one specified guy that's more reasonable + + + align:start position:0% +one specified guy that's more reasonable +unspecified unspecified now I look at + + align:start position:0% +unspecified unspecified now I look at + + + align:start position:0% +unspecified unspecified now I look at +the columns okay I've got four + + align:start position:0% +the columns okay I've got four + + + align:start position:0% +the columns okay I've got four +columns so what is what's possible + + align:start position:0% +columns so what is what's possible + + + align:start position:0% +columns so what is what's possible +here uh this column might have two guys + + align:start position:0% +here uh this column might have two guys + + + align:start position:0% +here uh this column might have two guys +it might have this specified and one + + align:start position:0% +it might have this specified and one + + + align:start position:0% +it might have this specified and one +more and unspecified unspecified right + + align:start position:0% +more and unspecified unspecified right + + + align:start position:0% +more and unspecified unspecified right +that that could be or I better have + + align:start position:0% +that that could be or I better have + + + align:start position:0% +that that could be or I better have +another or out + + align:start position:0% + + + + align:start position:0% + +here let's see let's see so I'm starting + + align:start position:0% +here let's see let's see so I'm starting + + + align:start position:0% +here let's see let's see so I'm starting +with these + + align:start position:0% + + + + align:start position:0% + +let's see what are the other well let me + + align:start position:0% +let's see what are the other well let me + + + align:start position:0% +let's see what are the other well let me +follow this case through first suppose + + align:start position:0% +follow this case through first suppose + + + align:start position:0% +follow this case through first suppose +this is my + + align:start position:0% +this is my + + + align:start position:0% +this is my +situation suppose remember I figured out + + align:start position:0% +situation suppose remember I figured out + + + align:start position:0% +situation suppose remember I figured out +okay one row does have to look like that + + align:start position:0% +okay one row does have to look like that + + + align:start position:0% +okay one row does have to look like that +well don't you have to + + align:start position:0% +well don't you have to + + + align:start position:0% +well don't you have to +have point where you're ring that's what + + align:start position:0% +have point where you're ring that's what + + + align:start position:0% +have point where you're ring that's what +I have to show and and this is so in + + align:start position:0% +I have to show and and this is so in + + + align:start position:0% +I have to show and and this is so in +this this is the good case where I do + + align:start position:0% +this this is the good case where I do + + + align:start position:0% +this this is the good case where I do +all right now what's the what's the deal + + align:start position:0% +all right now what's the what's the deal + + + align:start position:0% +all right now what's the what's the deal +here I have uh it looks like this and + + align:start position:0% +here I have uh it looks like this and + + + align:start position:0% +here I have uh it looks like this and +then how many are specified in here the + + align:start position:0% +then how many are specified in here the + + + align:start position:0% +then how many are specified in here the +remaining five so what's what's up with + + align:start position:0% +remaining five so what's what's up with + + + align:start position:0% +remaining five so what's what's up with +this + + align:start position:0% +this + + + align:start position:0% +this +case I apply the theorem for smaller + + align:start position:0% +case I apply the theorem for smaller + + + align:start position:0% +case I apply the theorem for smaller +size and I know I can complete this I + + align:start position:0% +size and I know I can complete this I + + + align:start position:0% +size and I know I can complete this I +can complete the five because it's + + align:start position:0% +can complete the five because it's + + + align:start position:0% +can complete the five because it's +satisfied all its little submatrices of + + align:start position:0% +satisfied all its little submatrices of + + + align:start position:0% +satisfied all its little submatrices of +course were part of the part of the part + + align:start position:0% +course were part of the part of the part + + + align:start position:0% +course were part of the part of the part +of the + + align:start position:0% +of the + + + align:start position:0% +of the +assume and it's got five which is the + + align:start position:0% +assume and it's got five which is the + + + align:start position:0% +assume and it's got five which is the +right number so I can complete it so + + align:start position:0% +right number so I can complete it so + + + align:start position:0% +right number so I can complete it so +somehow I do complete it now of course I + + align:start position:0% +somehow I do complete it now of course I + + + align:start position:0% +somehow I do complete it now of course I +have to just check having + + align:start position:0% +have to just check having + + + align:start position:0% +have to just check having +completed + + align:start position:0% +completed + + + align:start position:0% +completed +um some completed the this to have rank + + align:start position:0% +um some completed the this to have rank + + + align:start position:0% +um some completed the this to have rank +one uh can I now finish the + + align:start position:0% +one uh can I now finish the + + + align:start position:0% +one uh can I now finish the +job so now how do I finish the job + + align:start position:0% +job so now how do I finish the job + + + align:start position:0% +job so now how do I finish the job +here uh knowing that those rows are all + + align:start position:0% +here uh knowing that those rows are all + + + align:start position:0% +here uh knowing that those rows are all +in the same direction those three rows + + align:start position:0% +in the same direction those three rows + + + align:start position:0% +in the same direction those three rows +are multiples of each other in the small + + align:start position:0% +are multiples of each other in the small + + + align:start position:0% +are multiples of each other in the small +one now I have to achieve that in the + + align:start position:0% +one now I have to achieve that in the + + + align:start position:0% +one now I have to achieve that in the +4x4 okay well I guess I see one row + + align:start position:0% +4x4 okay well I guess I see one row + + + align:start position:0% +4x4 okay well I guess I see one row +completely + + align:start position:0% +completely + + + align:start position:0% +completely +set and so now how do I fill in this + + align:start position:0% +set and so now how do I fill in this + + + align:start position:0% +set and so now how do I fill in this +row just the ratio whatever I mean that + + align:start position:0% +row just the ratio whatever I mean that + + + align:start position:0% +row just the ratio whatever I mean that +row set this guy sets the ratio and I + + align:start position:0% +row set this guy sets the ratio and I + + + align:start position:0% +row set this guy sets the ratio and I +can fill it + + align:start position:0% + + + + align:start position:0% + +in and how do I fill that one in again + + align:start position:0% +in and how do I fill that one in again + + + align:start position:0% +in and how do I fill that one in again +this was in this was in a certain ratio + + align:start position:0% +this was in this was in a certain ratio + + + align:start position:0% +this was in this was in a certain ratio +with this one so the last entry has to + + align:start position:0% +with this one so the last entry has to + + + align:start position:0% +with this one so the last entry has to +stay in the same ratio and similarly + + align:start position:0% +stay in the same ratio and similarly + + + align:start position:0% +stay in the same ratio and similarly +here this was in a ratio with this + + align:start position:0% +here this was in a ratio with this + + + align:start position:0% +here this was in a ratio with this +because this was rank one in the in the + + align:start position:0% +because this was rank one in the in the + + + align:start position:0% +because this was rank one in the in the +3X3 and then when I'm given that I'm I'm + + align:start position:0% +3X3 and then when I'm given that I'm I'm + + + align:start position:0% +3X3 and then when I'm given that I'm I'm +given that so actually there's a unique + + align:start position:0% +given that so actually there's a unique + + + align:start position:0% +given that so actually there's a unique +way to + + align:start position:0% +way to + + + align:start position:0% +way to +finish so you could say yep that that + + align:start position:0% +finish so you could say yep that that + + + align:start position:0% +finish so you could say yep that that +was no anybody see that I've got one + + align:start position:0% +was no anybody see that I've got one + + + align:start position:0% +was no anybody see that I've got one +more case to worry + + align:start position:0% +more case to worry + + + align:start position:0% +more case to worry +about + + align:start position:0% +about + + + align:start position:0% +about +I well this this was x u u and then I + + align:start position:0% +I well this this was x u u and then I + + + align:start position:0% +I well this this was x u u and then I +said okay what if my row what if this + + align:start position:0% +said okay what if my row what if this + + + align:start position:0% +said okay what if my row what if this +column has + + align:start position:0% + + + + align:start position:0% + +uh let's + + align:start position:0% +uh let's + + + align:start position:0% +uh let's +see uh yeah what right that's a case I + + align:start position:0% +see uh yeah what right that's a case I + + + align:start position:0% +see uh yeah what right that's a case I +have to worry about what if nothing else + + align:start position:0% +have to worry about what if nothing else + + + align:start position:0% +have to worry about what if nothing else +was specified there why am + + align:start position:0% +was specified there why am + + + align:start position:0% +was specified there why am +I how do I know that that couldn't + + align:start position:0% +I how do I know that that couldn't + + + align:start position:0% +I how do I know that that couldn't +be because then I've got six more in the + + align:start position:0% +be because then I've got six more in the + + + align:start position:0% +be because then I've got six more in the +3X3 which which I assumed I didn't have + + align:start position:0% +3X3 which which I assumed I didn't have + + + align:start position:0% +3X3 which which I assumed I didn't have +okay now what okay I think I've got + + align:start position:0% +okay now what okay I think I've got + + + align:start position:0% +okay now what okay I think I've got +another case to worry about + + align:start position:0% +another case to worry about + + + align:start position:0% +another case to worry about +mathematicians are awful + + align:start position:0% +mathematicians are awful + + + align:start position:0% +mathematicians are awful +worriers all right what else do I have + + align:start position:0% +worriers all right what else do I have + + + align:start position:0% +worriers all right what else do I have +to think of maybe the what if what if + + align:start position:0% +to think of maybe the what if what if + + + align:start position:0% +to think of maybe the what if what if +this had + + align:start position:0% +this had + + + align:start position:0% +this had +more like three or or four now what do I + + align:start position:0% +more like three or or four now what do I + + + align:start position:0% +more like three or or four now what do I +deal how do I deal with that + + align:start position:0% + + + + align:start position:0% + +case what I'm hoping for is to find a + + align:start position:0% +case what I'm hoping for is to find a + + + align:start position:0% +case what I'm hoping for is to find a +3X3 that's that's + + align:start position:0% +3X3 that's that's + + + align:start position:0% +3X3 that's that's +okay uh now what's up + + align:start position:0% + + + + align:start position:0% + +here in this case one of those other + + align:start position:0% +here in this case one of those other + + + align:start position:0% +here in this case one of those other +columns only have one one of those other + + align:start position:0% +columns only have one one of those other + + + align:start position:0% +columns only have one one of those other +columns will only have one right one of + + align:start position:0% +columns will only have one right one of + + + align:start position:0% +columns will only have one right one of +those other columns will only have one + + align:start position:0% +those other columns will only have one + + + align:start position:0% +those other columns will only have one +because as I've used up three there's + + align:start position:0% +because as I've used up three there's + + + align:start position:0% +because as I've used up three there's +four four more to specify and only and + + align:start position:0% +four four more to specify and only and + + + align:start position:0% +four four more to specify and only and +three and three columns so so some other + + align:start position:0% +three and three columns so so some other + + + align:start position:0% +three and three columns so so some other +column has got got one easily right okay + + align:start position:0% +column has got got one easily right okay + + + align:start position:0% +column has got got one easily right okay +so suppose a second another column only + + align:start position:0% +so suppose a second another column only + + + align:start position:0% +so suppose a second another column only +has + + align:start position:0% + + + + align:start position:0% + +one all + + align:start position:0% + + + + align:start position:0% + +right now what do that like now yeah now + + align:start position:0% +right now what do that like now yeah now + + + align:start position:0% +right now what do that like now yeah now +the good columns to look at are this + + align:start position:0% +the good columns to look at are this + + + align:start position:0% +the good columns to look at are this +this row and that column this row and + + align:start position:0% +this row and that column this row and + + + align:start position:0% +this row and that column this row and +that column I I'll move that column + + align:start position:0% +that column I I'll move that column + + + align:start position:0% +that column I I'll move that column +over or you see + + align:start position:0% +over or you see + + + align:start position:0% +over or you see +out of this row and that column I've + + align:start position:0% +out of this row and that column I've + + + align:start position:0% +out of this row and that column I've +used two so I'm remaining with a + + align:start position:0% +used two so I'm remaining with a + + + align:start position:0% +used two so I'm remaining with a +3X3 I have a 3X3 remaining with + + align:start position:0% + + + + align:start position:0% + +five you see that if I look at this + + align:start position:0% +five you see that if I look at this + + + align:start position:0% +five you see that if I look at this +remaining 3 by3 because this row and + + align:start position:0% +remaining 3 by3 because this row and + + + align:start position:0% +remaining 3 by3 because this row and +column have only used two only specified + + align:start position:0% +column have only used two only specified + + + align:start position:0% +column have only used two only specified +two I have five unspecified ones in this + + align:start position:0% +two I have five unspecified ones in this + + + align:start position:0% +two I have five unspecified ones in this +3x3 I can fit I can complete + + align:start position:0% +3x3 I can fit I can complete + + + align:start position:0% +3x3 I can fit I can complete +those + + align:start position:0% +those + + + align:start position:0% +those +by induction by the is that right + + align:start position:0% +by induction by the is that right + + + align:start position:0% +by induction by the is that right +y right because whatever some some of + + align:start position:0% +y right because whatever some some of + + + align:start position:0% +y right because whatever some some of +those were specified but but a total of + + align:start position:0% +those were specified but but a total of + + + align:start position:0% +those were specified but but a total of +five were specified and I can finish the + + align:start position:0% +five were specified and I can finish the + + + align:start position:0% +five were specified and I can finish the +job on the + + align:start position:0% +job on the + + + align:start position:0% +job on the +3X3 and then uh again I'm + + align:start position:0% +3X3 and then uh again I'm + + + align:start position:0% +3X3 and then uh again I'm +uh then I can finish the complete job + + align:start position:0% +uh then I can finish the complete job + + + align:start position:0% +uh then I can finish the complete job +because now I have a row completely set + + align:start position:0% +because now I have a row completely set + + + align:start position:0% +because now I have a row completely set +and that will set the remaining rows I + + align:start position:0% +and that will set the remaining rows I + + + align:start position:0% +and that will set the remaining rows I +can am I + + align:start position:0% + + + + align:start position:0% + +okay all right + + align:start position:0% + + + + align:start position:0% + +I I've partly convinced you by shouting + + align:start position:0% +I I've partly convinced you by shouting + + + align:start position:0% +I I've partly convinced you by shouting +right but uh but + + align:start position:0% +right but uh but + + + align:start position:0% +right but uh but +uh that's how the the the proof uh + + align:start position:0% +uh that's how the the the proof uh + + + align:start position:0% +uh that's how the the the proof uh +didn't turn out to be too messy and I + + align:start position:0% +didn't turn out to be too messy and I + + + align:start position:0% +didn't turn out to be too messy and I +probably could tighten it up a little + + align:start position:0% +probably could tighten it up a little + + + align:start position:0% +probably could tighten it up a little +bit in in what I've described but that + + align:start position:0% +bit in in what I've described but that + + + align:start position:0% +bit in in what I've described but that +that's sort of + + align:start position:0% +that's sort of + + + align:start position:0% +that's sort of +the the way the proof would have to + + align:start position:0% +the the way the proof would have to + + + align:start position:0% +the the way the proof would have to +argue by induction that that there has + + align:start position:0% +argue by induction that that there has + + + align:start position:0% +argue by induction that that there has +to be a row with only one specified then + + align:start position:0% +to be a row with only one specified then + + + align:start position:0% +to be a row with only one specified then +we check the columns we look at the + + align:start position:0% +we check the columns we look at the + + + align:start position:0% +we check the columns we look at the +possibilities not too many we eventually + + align:start position:0% +possibilities not too many we eventually + + + align:start position:0% +possibilities not too many we eventually +we either rule out some of those + + align:start position:0% +we either rule out some of those + + + align:start position:0% +we either rule out some of those +possibilities or we identify a smaller + + align:start position:0% +possibilities or we identify a smaller + + + align:start position:0% +possibilities or we identify a smaller +Matrix that obeys the rules and then by + + align:start position:0% +Matrix that obeys the rules and then by + + + align:start position:0% +Matrix that obeys the rules and then by +the induction step we can complete that + + align:start position:0% +the induction step we can complete that + + + align:start position:0% +the induction step we can complete that +Matrix and then we finish okay so that's + + align:start position:0% +Matrix and then we finish okay so that's + + + align:start position:0% +Matrix and then we finish okay so that's +that's that and let me tell you + + align:start position:0% +that's that and let me tell you + + + align:start position:0% +that's that and let me tell you +about if if you're willing to go one + + align:start position:0% +about if if you're willing to go one + + + align:start position:0% +about if if you're willing to go one +more minute on this + + align:start position:0% +more minute on this + + + align:start position:0% +more minute on this +question what about completing to rank + + align:start position:0% +question what about completing to rank + + + align:start position:0% +question what about completing to rank +two because of course the trouble is + + align:start position:0% +two because of course the trouble is + + + align:start position:0% +two because of course the trouble is +another bad thing about mathematicians + + align:start position:0% +another bad thing about mathematicians + + + align:start position:0% +another bad thing about mathematicians +once you finish right you get the proof + + align:start position:0% +once you finish right you get the proof + + + align:start position:0% +once you finish right you get the proof +happy you're only happy for about 30 + + align:start position:0% +happy you're only happy for about 30 + + + align:start position:0% +happy you're only happy for about 30 +seconds because then you think of the + + align:start position:0% +seconds because then you think of the + + + align:start position:0% +seconds because then you think of the +next case and it's always harder so now + + align:start position:0% +next case and it's always harder so now + + + align:start position:0% +next case and it's always harder so now +suppose we're trying to complete a + + align:start position:0% +suppose we're trying to complete a + + + align:start position:0% +suppose we're trying to complete a +matrix to rank two + + align:start position:0% +matrix to rank two + + + align:start position:0% +matrix to rank two +all right I'm jumping now to a new + + align:start position:0% +all right I'm jumping now to a new + + + align:start position:0% +all right I'm jumping now to a new +question how many would I expect to + + align:start position:0% +question how many would I expect to + + + align:start position:0% +question how many would I expect to +specify say in a 4x4 say in a 4x4 how + + align:start position:0% +specify say in a 4x4 say in a 4x4 how + + + align:start position:0% +specify say in a 4x4 say in a 4x4 how +many entries would I expect to + + align:start position:0% +many entries would I expect to + + + align:start position:0% +many entries would I expect to +specify here it was 2K minus one seven + + align:start position:0% +specify here it was 2K minus one seven + + + align:start position:0% +specify here it was 2K minus one seven +how many now if I'm going to complete to + + align:start position:0% +how many now if I'm going to complete to + + + align:start position:0% +how many now if I'm going to complete to +rank two that's easier + + align:start position:0% +rank two that's easier + + + align:start position:0% +rank two that's easier +right easier to rank two because then I + + align:start position:0% +right easier to rank two because then I + + + align:start position:0% +right easier to rank two because then I +can have two rows that are quite + + align:start position:0% +can have two rows that are quite + + + align:start position:0% +can have two rows that are quite +different and the others have to be + + align:start position:0% +different and the others have to be + + + align:start position:0% +different and the others have to be +combinations of those so I could have + + align:start position:0% +combinations of those so I could have + + + align:start position:0% +combinations of those so I could have +two rows specified completely + + align:start position:0% +two rows specified completely + + + align:start position:0% +two rows specified completely +differently any + + align:start position:0% +differently any + + + align:start position:0% +differently any +completely I'm using X right for for + + align:start position:0% +completely I'm using X right for for + + + align:start position:0% +completely I'm using X right for for +specified I could specify two rows + + align:start position:0% +specified I could specify two rows + + + align:start position:0% +specified I could specify two rows +arbitrarily now I could + + align:start position:0% +arbitrarily now I could + + + align:start position:0% +arbitrarily now I could +specify two entries in the third row and + + align:start position:0% +specify two entries in the third row and + + + align:start position:0% +specify two entries in the third row and +then do you do you see that I could I + + align:start position:0% +then do you do you see that I could I + + + align:start position:0% +then do you do you see that I could I +could finish the + + align:start position:0% +could finish the + + + align:start position:0% +could finish the +job and keep rank two + + align:start position:0% +job and keep rank two + + + align:start position:0% +job and keep rank two +I I'm what I'm trying to do first is + + align:start position:0% +I I'm what I'm trying to do first is + + + align:start position:0% +I I'm what I'm trying to do first is +guess the right + + align:start position:0% +guess the right + + + align:start position:0% +guess the right +number and I'll do that by assuming that + + align:start position:0% +number and I'll do that by assuming that + + + align:start position:0% +number and I'll do that by assuming that +they're in a nice pattern and and and + + align:start position:0% +they're in a nice pattern and and and + + + align:start position:0% +they're in a nice pattern and and and +see okay how many could I expect to do + + align:start position:0% +see okay how many could I expect to do + + + align:start position:0% +see okay how many could I expect to do +in that pattern okay suppose I'm given + + align:start position:0% +in that pattern okay suppose I'm given + + + align:start position:0% +in that pattern okay suppose I'm given +two complete rows then if I'm given this + + align:start position:0% +two complete rows then if I'm given this + + + align:start position:0% +two complete rows then if I'm given this +row and this row that number and that + + align:start position:0% +row and this row that number and that + + + align:start position:0% +row and this row that number and that +number that tells me what combination of + + align:start position:0% +number that tells me what combination of + + + align:start position:0% +number that tells me what combination of +this row and this row it takes to get + + align:start position:0% +this row and this row it takes to get + + + align:start position:0% +this row and this row it takes to get +these two guys right right I've got two + + align:start position:0% +these two guys right right I've got two + + + align:start position:0% +these two guys right right I've got two +coefficients in that combination so I + + align:start position:0% +coefficients in that combination so I + + + align:start position:0% +coefficients in that combination so I +can get I can take a combination to get + + align:start position:0% +can get I can take a combination to get + + + align:start position:0% +can get I can take a combination to get +these two right and then I better have + + align:start position:0% +these two right and then I better have + + + align:start position:0% +these two right and then I better have +those unsp specified because they're + + align:start position:0% +those unsp specified because they're + + + align:start position:0% +those unsp specified because they're +going to be whatever they come out and + + align:start position:0% +going to be whatever they come out and + + + align:start position:0% +going to be whatever they come out and +similarly + + align:start position:0% +similarly + + + align:start position:0% +similarly +here I can I can uh specify + + align:start position:0% +here I can I can uh specify + + + align:start position:0% +here I can I can uh specify +two and uh some combination of those two + + align:start position:0% +two and uh some combination of those two + + + align:start position:0% +two and uh some combination of those two +rows will match those two and then those + + align:start position:0% +rows will match those two and then those + + + align:start position:0% +rows will match those two and then those +unspecified ones will be filled in I'm + + align:start position:0% +unspecified ones will be filled in I'm + + + align:start position:0% +unspecified ones will be filled in I'm +discovering in a 4x4 case I can I would + + align:start position:0% +discovering in a 4x4 case I can I would + + + align:start position:0% +discovering in a 4x4 case I can I would +think I can spe specify + + align:start position:0% +think I can spe specify + + + align:start position:0% +think I can spe specify +12 and but that's the question here I + + align:start position:0% +12 and but that's the question here I + + + align:start position:0% +12 and but that's the question here I +can those 12 I can + + align:start position:0% + + + + align:start position:0% + +specify and of course the right so the + + align:start position:0% +specify and of course the right so the + + + align:start position:0% +specify and of course the right so the +question + + align:start position:0% +question + + + align:start position:0% +question +is can I alwayss like your 2 by two case + + align:start position:0% +is can I alwayss like your 2 by two case + + + align:start position:0% +is can I alwayss like your 2 by two case +with rank one it yes it's + + align:start position:0% +with rank one it yes it's + + + align:start position:0% +with rank one it yes it's +it's okay so I went away thinking well + + align:start position:0% +it's okay so I went away thinking well + + + align:start position:0% +it's okay so I went away thinking well +all right got this proof got the right + + align:start position:0% +all right got this proof got the right + + + align:start position:0% +all right got this proof got the right +number here 12 can't be that hard but + + align:start position:0% +number here 12 can't be that hard but + + + align:start position:0% +number here 12 can't be that hard but +then + + align:start position:0% +then + + + align:start position:0% +then +um I came up with a case that I didn't + + align:start position:0% +um I came up with a case that I didn't + + + align:start position:0% +um I came up with a case that I didn't +know how to do it so so this I decided + + align:start position:0% +know how to do it so so this I decided + + + align:start position:0% +know how to do it so so this I decided +this + + align:start position:0% +this + + + align:start position:0% +this +is this is so I don't know the I I don't + + align:start position:0% +is this is so I don't know the I I don't + + + align:start position:0% +is this is so I don't know the I I don't +have a proof yet I I should say we I'm + + align:start position:0% +have a proof yet I I should say we I'm + + + align:start position:0% +have a proof yet I I should say we I'm +doing this with a really sharp young guy + + align:start position:0% +doing this with a really sharp young guy + + + align:start position:0% +doing this with a really sharp young guy +named David ingerman he's he's the + + align:start position:0% +named David ingerman he's he's the + + + align:start position:0% +named David ingerman he's he's the +source of ideas here okay so now can I + + align:start position:0% +source of ideas here okay so now can I + + + align:start position:0% +source of ideas here okay so now can I +specify any 12 well let me show you what + + align:start position:0% +specify any 12 well let me show you what + + + align:start position:0% +specify any 12 well let me show you what +I got hung up on + + align:start position:0% + + + + align:start position:0% + +could I specify this is 4x4 I think I + + align:start position:0% +could I specify this is 4x4 I think I + + + align:start position:0% +could I specify this is 4x4 I think I +can specify 12 I was pretty sure but now + + align:start position:0% +can specify 12 I was pretty sure but now + + + align:start position:0% +can specify 12 I was pretty sure but now +suppose my unspecified are the + + align:start position:0% +suppose my unspecified are the + + + align:start position:0% +suppose my unspecified are the +diagonal and I specify all 12 of these + + align:start position:0% + + + + align:start position:0% + +guys so I specify those 12 numbers and + + align:start position:0% +guys so I specify those 12 numbers and + + + align:start position:0% +guys so I specify those 12 numbers and +these four I could leave blank as a sort + + align:start position:0% +these four I could leave blank as a sort + + + align:start position:0% +these four I could leave blank as a sort +of way to see that those are not + + align:start position:0% +of way to see that those are not + + + align:start position:0% +of way to see that those are not +specified and I want to fill this in to + + align:start position:0% +specified and I want to fill this in to + + + align:start position:0% +specified and I want to fill this in to +have rank two fill complete to rank + + align:start position:0% + + + + align:start position:0% + +two well can you interchange rows and + + align:start position:0% +two well can you interchange rows and + + + align:start position:0% +two well can you interchange rows and +columns + + align:start position:0% +columns + + + align:start position:0% +columns +I get in of the second well if + + align:start position:0% +I get in of the second well if + + + align:start position:0% +I get in of the second well if +that's yeah if so done but the trouble + + align:start position:0% +that's yeah if so done but the trouble + + + align:start position:0% +that's yeah if so done but the trouble +is there's a row with only two guys in + + align:start position:0% +is there's a row with only two guys in + + + align:start position:0% +is there's a row with only two guys in +it if I move move it elsewhere it's + + align:start position:0% +it if I move move it elsewhere it's + + + align:start position:0% +it if I move move it elsewhere it's +still I got only two if I move it if I + + align:start position:0% +still I got only two if I move it if I + + + align:start position:0% +still I got only two if I move it if I +move yeah but think I mean this is + + align:start position:0% +move yeah but think I mean this is + + + align:start position:0% +move yeah but think I mean this is +exactly the right question so I move + + align:start position:0% +exactly the right question so I move + + + align:start position:0% +exactly the right question so I move +that row up or down still has two if I + + align:start position:0% +that row up or down still has two if I + + + align:start position:0% +that row up or down still has two if I +change columns what happens on that row + + align:start position:0% +change columns what happens on that row + + + align:start position:0% +change columns what happens on that row +those two are still there they just in + + align:start position:0% +those two are still there they just in + + + align:start position:0% +those two are still there they just in +different columns so that's why this one + + align:start position:0% +different columns so that's why this one + + + align:start position:0% +different columns so that's why this one +was so hard because this has got three + + align:start position:0% +was so hard because this has got three + + + align:start position:0% +was so hard because this has got three +in every Row three in every column and I + + align:start position:0% +in every Row three in every column and I + + + align:start position:0% +in every Row three in every column and I +can't with just simple reordering get + + align:start position:0% +can't with just simple reordering get + + + align:start position:0% +can't with just simple reordering get +out of that fix + + align:start position:0% +out of that fix + + + align:start position:0% +out of that fix +so I couldn't see how to do it frankly + + align:start position:0% +so I couldn't see how to do it frankly + + + align:start position:0% +so I couldn't see how to do it frankly +you know you where do you start I didn't + + align:start position:0% +you know you where do you start I didn't + + + align:start position:0% +you know you where do you start I didn't +have a starting Place + + align:start position:0% +have a starting Place + + + align:start position:0% +have a starting Place +somehow and + + align:start position:0% +somehow and + + + align:start position:0% +somehow and +um let me call these numbers like uh A + + align:start position:0% +um let me call these numbers like uh A + + + align:start position:0% +um let me call these numbers like uh A +and B that we would like to be able to + + align:start position:0% +and B that we would like to be able to + + + align:start position:0% +and B that we would like to be able to +find a b c + + align:start position:0% +find a b c + + + align:start position:0% +find a b c +d okay now yesterday afternoon David + + align:start position:0% +d okay now yesterday afternoon David + + + align:start position:0% +d okay now yesterday afternoon David +convinced me I could we could do this + + align:start position:0% +convinced me I could we could do this + + + align:start position:0% +convinced me I could we could do this +one so I can show you how he what he + + align:start position:0% +one so I can show you how he what he + + + align:start position:0% +one so I can show you how he what he +sold me on here okay how he did it and + + align:start position:0% +sold me on here okay how he did it and + + + align:start position:0% +sold me on here okay how he did it and +then that's only so at this point so + + align:start position:0% +then that's only so at this point so + + + align:start position:0% +then that's only so at this point so +this is again a progress report uh our + + align:start position:0% +this is again a progress report uh our + + + align:start position:0% +this is again a progress report uh our +progress report I think is he figured + + align:start position:0% +progress report I think is he figured + + + align:start position:0% +progress report I think is he figured +out how to do this one this particular + + align:start position:0% +out how to do this one this particular + + + align:start position:0% +out how to do this one this particular +one so I still have we still have the + + align:start position:0% +one so I still have we still have the + + + align:start position:0% +one so I still have we still have the +question of any + + align:start position:0% +question of any + + + align:start position:0% +question of any +12 in a + + align:start position:0% +12 in a + + + align:start position:0% +12 in a +4x4 and then the more general question + + align:start position:0% +4x4 and then the more general question + + + align:start position:0% +4x4 and then the more general question +is so completion so let me complete the + + align:start position:0% +is so completion so let me complete the + + + align:start position:0% +is so completion so let me complete the +the the the theorem completion to rank + + align:start position:0% +the the the theorem completion to rank + + + align:start position:0% +the the the theorem completion to rank +two the number here becomes everything + + align:start position:0% +two the number here becomes everything + + + align:start position:0% +two the number here becomes everything +should is 4 K minus 4 that's the right + + align:start position:0% +should is 4 K minus 4 that's the right + + + align:start position:0% +should is 4 K minus 4 that's the right +number which when K is 4 that's 16us 4 + + align:start position:0% +number which when K is 4 that's 16us 4 + + + align:start position:0% +number which when K is 4 that's 16us 4 +which is our 12 so this was the this is + + align:start position:0% +which is our 12 so this was the this is + + + align:start position:0% +which is our 12 so this was the this is +the the guess conjecture you could say + + align:start position:0% +the the guess conjecture you could say + + + align:start position:0% +the the guess conjecture you could say +completion to rank two is possible if + + align:start position:0% +completion to rank two is possible if + + + align:start position:0% +completion to rank two is possible if +and only if every submatrix of order K + + align:start position:0% +and only if every submatrix of order K + + + align:start position:0% +and only if every submatrix of order K +has no more than 4K minus 4 let let me + + align:start position:0% +has no more than 4K minus 4 let let me + + + align:start position:0% +has no more than 4K minus 4 let let me +check 3x 3x3 what would that say I I'm + + align:start position:0% +check 3x 3x3 what would that say I I'm + + + align:start position:0% +check 3x 3x3 what would that say I I'm +saying that I can complete to rank two + + align:start position:0% +saying that I can complete to rank two + + + align:start position:0% +saying that I can complete to rank two +uh and suppose it was 3x3 how many am I + + align:start position:0% +uh and suppose it was 3x3 how many am I + + + align:start position:0% +uh and suppose it was 3x3 how many am I +specifying just just I'm specifying + + align:start position:0% +specifying just just I'm specifying + + + align:start position:0% +specifying just just I'm specifying +eight now is it true that if I had a 3X3 + + align:start position:0% +eight now is it true that if I had a 3X3 + + + align:start position:0% +eight now is it true that if I had a 3X3 +Matrix and I specify + + align:start position:0% +Matrix and I specify + + + align:start position:0% +Matrix and I specify +eight well how many have I got left only + + align:start position:0% +eight well how many have I got left only + + + align:start position:0% +eight well how many have I got left only +one left can I at rank + + align:start position:0% + + + + align:start position:0% + +two just just that that one if we can't + + align:start position:0% +two just just that that one if we can't + + + align:start position:0% +two just just that that one if we can't +do 3x3 well just go and shoot ourselves + + align:start position:0% +do 3x3 well just go and shoot ourselves + + + align:start position:0% +do 3x3 well just go and shoot ourselves +so so uh so + + align:start position:0% +so so uh so + + + align:start position:0% +so so uh so +3x3 + + align:start position:0% +3x3 + + + align:start position:0% +3x3 +3x3 so this is rank two I'm still I'm + + align:start position:0% +3x3 so this is rank two I'm still I'm + + + align:start position:0% +3x3 so this is rank two I'm still I'm +still into the rank two thing if 3x3 and + + align:start position:0% +still into the rank two thing if 3x3 and + + + align:start position:0% +still into the rank two thing if 3x3 and +with eight specified eight X's well put + + align:start position:0% +with eight specified eight X's well put + + + align:start position:0% +with eight specified eight X's well put +them + + align:start position:0% +them + + + align:start position:0% +them +wherever that's eight only one left only + + align:start position:0% +wherever that's eight only one left only + + + align:start position:0% +wherever that's eight only one left only +one one Freedom left but I want to get I + + align:start position:0% +one one Freedom left but I want to get I + + + align:start position:0% +one one Freedom left but I want to get I +only I'm aiming for rank two how do I do + + align:start position:0% + + + + align:start position:0% + +Itor yes that's right uh so in terms of + + align:start position:0% +Itor yes that's right uh so in terms of + + + align:start position:0% +Itor yes that's right uh so in terms of +linear + + align:start position:0% +linear + + + align:start position:0% +linear +algebra so this is + + align:start position:0% +algebra so this is + + + align:start position:0% +algebra so this is +unspecified + + align:start position:0% +unspecified + + + align:start position:0% +unspecified +the some combination of that well + + align:start position:0% +the some combination of that well + + + align:start position:0% +the some combination of that well +another a quick way to say it is make + + align:start position:0% +another a quick way to say it is make + + + align:start position:0% +another a quick way to say it is make +the + + align:start position:0% +the + + + align:start position:0% +the +determinant what Zer zero make the + + align:start position:0% +determinant what Zer zero make the + + + align:start position:0% +determinant what Zer zero make the +determinant zero which the whole the 3X3 + + align:start position:0% +determinant zero which the whole the 3X3 + + + align:start position:0% +determinant zero which the whole the 3X3 +if the 3X3 determinant is zero What's + + align:start position:0% +if the 3X3 determinant is zero What's + + + align:start position:0% +if the 3X3 determinant is zero What's +the + + align:start position:0% + + + + align:start position:0% + +rank less than three + + align:start position:0% +rank less than three + + + align:start position:0% +rank less than three +two take two right does does it have to + + align:start position:0% +two take two right does does it have to + + + align:start position:0% +two take two right does does it have to +be exactly r two no no no no less or + + align:start position:0% +be exactly r two no no no no less or + + + align:start position:0% +be exactly r two no no no no less or +equal rank two yeah less or equal rank + + align:start position:0% +equal rank two yeah less or equal rank + + + align:start position:0% +equal rank two yeah less or equal rank +two yeah yeah yeah I have to achieve + + align:start position:0% +two yeah yeah yeah I have to achieve + + + align:start position:0% +two yeah yeah yeah I have to achieve +rank two but of course if I made if I + + align:start position:0% +rank two but of course if I made if I + + + align:start position:0% +rank two but of course if I made if I +specified stuff you know if I specified + + align:start position:0% +specified stuff you know if I specified + + + align:start position:0% +specified stuff you know if I specified +that row exactly in the same direction + + align:start position:0% +that row exactly in the same direction + + + align:start position:0% +that row exactly in the same direction +as that row then and and all sorts of + + align:start position:0% +as that row then and and all sorts of + + + align:start position:0% +as that row then and and all sorts of +stuff then I could maybe even get lower + + align:start position:0% +stuff then I could maybe even get lower + + + align:start position:0% +stuff then I could maybe even get lower +rank but but I'm shooting here for rank + + align:start position:0% +rank but but I'm shooting here for rank + + + align:start position:0% +rank but but I'm shooting here for rank +two so I'm saying if you give me eight I + + align:start position:0% +two so I'm saying if you give me eight I + + + align:start position:0% +two so I'm saying if you give me eight I +can certainly fill in that ninth what + + align:start position:0% +can certainly fill in that ninth what + + + align:start position:0% +can certainly fill in that ninth what +one way the way we saw it was some + + align:start position:0% +one way the way we saw it was some + + + align:start position:0% +one way the way we saw it was some +combination of that row and that row + + align:start position:0% +combination of that row and that row + + + align:start position:0% +combination of that row and that row +will make those two right and it'll tell + + align:start position:0% +will make those two right and it'll tell + + + align:start position:0% +will make those two right and it'll tell +me what that has to be and just I'm just + + align:start position:0% +me what that has to be and just I'm just + + + align:start position:0% +me what that has to be and just I'm just +saying to say the same thing in another + + align:start position:0% +saying to say the same thing in another + + + align:start position:0% +saying to say the same thing in another +language some number there will make the + + align:start position:0% +language some number there will make the + + + align:start position:0% +language some number there will make the +determinate + + align:start position:0% +determinate + + + align:start position:0% +determinate +zero some number there will make the + + align:start position:0% +zero some number there will make the + + + align:start position:0% +zero some number there will make the +determinate zero so I'm okay but + + align:start position:0% +determinate zero so I'm okay but + + + align:start position:0% +determinate zero so I'm okay but +so 3x3 completing to rank two no problem + + align:start position:0% +so 3x3 completing to rank two no problem + + + align:start position:0% +so 3x3 completing to rank two no problem +but 4x4 with 12 specified completing to + + align:start position:0% +but 4x4 with 12 specified completing to + + + align:start position:0% +but 4x4 with 12 specified completing to +rank two big headache okay so can I show + + align:start position:0% +rank two big headache okay so can I show + + + align:start position:0% +rank two big headache okay so can I show +can I come back to this one now this is + + align:start position:0% +can I come back to this one now this is + + + align:start position:0% +can I come back to this one now this is +my last case that I know + + align:start position:0% +my last case that I know + + + align:start position:0% +my last case that I know +about and then the goal is to get the + + align:start position:0% +about and then the goal is to get the + + + align:start position:0% +about and then the goal is to get the +theorem to work for for rank two + + align:start position:0% +theorem to work for for rank two + + + align:start position:0% +theorem to work for for rank two +completion where this is for okay here + + align:start position:0% +completion where this is for okay here + + + align:start position:0% +completion where this is for okay here +here was the + + align:start position:0% +here was the + + + align:start position:0% +here was the +idea suppose I look at this this and + + align:start position:0% +idea suppose I look at this this and + + + align:start position:0% +idea suppose I look at this this and +this so a + + align:start position:0% +this so a + + + align:start position:0% +this so a +3X3 and I and I I I I certainly have to + + align:start position:0% +3X3 and I and I I I I certainly have to + + + align:start position:0% +3X3 and I and I I I I certainly have to +complete that to rank + + align:start position:0% +complete that to rank + + + align:start position:0% +complete that to rank +two + + align:start position:0% +two + + + align:start position:0% +two +so what'll it take well let's look at + + align:start position:0% +so what'll it take well let's look at + + + align:start position:0% +so what'll it take well let's look at +the + + align:start position:0% +the + + + align:start position:0% +the +determinant so I'd like to complete this + + align:start position:0% +determinant so I'd like to complete this + + + align:start position:0% +determinant so I'd like to complete this +so what's the determinant I have to make + + align:start position:0% +so what's the determinant I have to make + + + align:start position:0% +so what's the determinant I have to make +the determinant zero + + align:start position:0% +the determinant zero + + + align:start position:0% +the determinant zero +right if I have a 3X three and I'm + + align:start position:0% +right if I have a 3X three and I'm + + + align:start position:0% +right if I have a 3X three and I'm +trying to get lower rank rank two that + + align:start position:0% +trying to get lower rank rank two that + + + align:start position:0% +trying to get lower rank rank two that +surely means it's singular it's + + align:start position:0% +surely means it's singular it's + + + align:start position:0% +surely means it's singular it's +determinant is zero so so + + align:start position:0% +determinant is zero so so + + + align:start position:0% +determinant is zero so so +uh so the determinant of that will have + + align:start position:0% +uh so the determinant of that will have + + + align:start position:0% +uh so the determinant of that will have +to be zero so what's what is the + + align:start position:0% +to be zero so what's what is the + + + align:start position:0% +to be zero so what's what is the +determin it's a * B time a * B * + + align:start position:0% +determin it's a * B time a * B * + + + align:start position:0% +determin it's a * B time a * B * +something times times uh + + align:start position:0% +something times times uh + + + align:start position:0% +something times times uh +something and then what else how many + + align:start position:0% +something and then what else how many + + + align:start position:0% +something and then what else how many +you remember a 3X3 + + align:start position:0% +you remember a 3X3 + + + align:start position:0% +you remember a 3X3 +determinant what's it going to look like + + align:start position:0% +determinant what's it going to look like + + + align:start position:0% +determinant what's it going to look like +it only involves there's an AB term and + + align:start position:0% +it only involves there's an AB term and + + + align:start position:0% +it only involves there's an AB term and +then there's will be a an a time + + align:start position:0% +then there's will be a an a time + + + align:start position:0% +then there's will be a an a time +something q a * some specified and a b + + align:start position:0% +something q a * some specified and a b + + + align:start position:0% +something q a * some specified and a b +times something + + align:start position:0% +times something + + + align:start position:0% +times something +specified and uh and other constant and + + align:start position:0% +specified and uh and other constant and + + + align:start position:0% +specified and uh and other constant and +other specified terms that don't involve + + align:start position:0% +other specified terms that don't involve + + + align:start position:0% +other specified terms that don't involve +A and B has to be + + align:start position:0% + + + + align:start position:0% + +zero that's the determinant that's the + + align:start position:0% +zero that's the determinant that's the + + + align:start position:0% +zero that's the determinant that's the +3X3 + + align:start position:0% +3X3 + + + align:start position:0% +3X3 +determinant okay but the thing is it + + align:start position:0% +determinant okay but the thing is it + + + align:start position:0% +determinant okay but the thing is it +involves both A and B + + align:start position:0% +involves both A and B + + + align:start position:0% +involves both A and B +so I mean that's only one of the many + + align:start position:0% +so I mean that's only one of the many + + + align:start position:0% +so I mean that's only one of the many +equations many 3x3 determinants but it's + + align:start position:0% +equations many 3x3 determinants but it's + + + align:start position:0% +equations many 3x3 determinants but it's +the one I want to look at and the other + + align:start position:0% +the one I want to look at and the other + + + align:start position:0% +the one I want to look at and the other +one I want to look at is this one can I + + align:start position:0% +one I want to look at is this one can I + + + align:start position:0% +one I want to look at is this one can I +I'll Circle the another 3x3 that's + + align:start position:0% +I'll Circle the another 3x3 that's + + + align:start position:0% +I'll Circle the another 3x3 that's +interesting in yellow + + align:start position:0% +interesting in yellow + + + align:start position:0% +interesting in yellow +take + + align:start position:0% +take + + + align:start position:0% +take +this I just want to use a and b can I I + + align:start position:0% +this I just want to use a and b can I I + + + align:start position:0% +this I just want to use a and b can I I +want to use + + align:start position:0% +want to use + + + align:start position:0% +want to use +this this and + + align:start position:0% +this this and + + + align:start position:0% +this this and +this + + align:start position:0% +this + + + align:start position:0% +this +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +and no let me + + align:start position:0% +and no let me + + + align:start position:0% +and no let me +see what a where's it gone I haven't got + + align:start position:0% +see what a where's it gone I haven't got + + + align:start position:0% +see what a where's it gone I haven't got +David to help me here I'm looking for + + align:start position:0% +David to help me here I'm looking for + + + align:start position:0% +David to help me here I'm looking for +and and this is that + + align:start position:0% +and and this is that + + + align:start position:0% +and and this is that +right I'm looking for a + + align:start position:0% + + + + align:start position:0% + +three no no here this this and this okay + + align:start position:0% +three no no here this this and this okay + + + align:start position:0% +three no no here this this and this okay +there's another 3x3 + + align:start position:0% + + + + align:start position:0% + +so it's determined also has to be zero + + align:start position:0% +so it's determined also has to be zero + + + align:start position:0% +so it's determined also has to be zero +and it involves it's independent because + + align:start position:0% +and it involves it's independent because + + + align:start position:0% +and it involves it's independent because +it involves these three numbers and not + + align:start position:0% +it involves these three numbers and not + + + align:start position:0% +it involves these three numbers and not +these three that were that appeared here + + align:start position:0% +these three that were that appeared here + + + align:start position:0% +these three that were that appeared here +so for this determinant to be zero okay + + align:start position:0% +so for this determinant to be zero okay + + + align:start position:0% +so for this determinant to be zero okay +what's it what's that determinant well + + align:start position:0% +what's it what's that determinant well + + + align:start position:0% +what's it what's that determinant well +again I have an AB it looks just like + + align:start position:0% +again I have an AB it looks just like + + + align:start position:0% +again I have an AB it looks just like +this AB times some other specified thing + + align:start position:0% +this AB times some other specified thing + + + align:start position:0% +this AB times some other specified thing +plus a * some other specified thing Q + + align:start position:0% +plus a * some other specified thing Q + + + align:start position:0% +plus a * some other specified thing Q +Plus B B time some other specified thing + + align:start position:0% +Plus B B time some other specified thing + + + align:start position:0% +Plus B B time some other specified thing +R plus some other specified thing has to + + align:start position:0% +R plus some other specified thing has to + + + align:start position:0% +R plus some other specified thing has to +be + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% + + + + align:start position:0% + +well out of this I can here's the punch + + align:start position:0% +well out of this I can here's the punch + + + align:start position:0% +well out of this I can here's the punch +line then out of this I can determine A + + align:start position:0% +line then out of this I can determine A + + + align:start position:0% +line then out of this I can determine A +and B they're they're nonlinear + + align:start position:0% +and B they're they're nonlinear + + + align:start position:0% +and B they're they're nonlinear +equations that's a little scary but I + + align:start position:0% +equations that's a little scary but I + + + align:start position:0% +equations that's a little scary but I +can I can uh uh subtract write multiple + + align:start position:0% +can I can uh uh subtract write multiple + + + align:start position:0% +can I can uh uh subtract write multiple +of this equation from this one and kill + + align:start position:0% +of this equation from this one and kill + + + align:start position:0% +of this equation from this one and kill +the ab and then I have a linear equation + + align:start position:0% +the ab and then I have a linear equation + + + align:start position:0% +the ab and then I have a linear equation +connecting A and B so I can solve for a + + align:start position:0% +connecting A and B so I can solve for a + + + align:start position:0% +connecting A and B so I can solve for a +and I can plug in then I get a quadratic + + align:start position:0% +and I can plug in then I get a quadratic + + + align:start position:0% +and I can plug in then I get a quadratic +equation for a which I can Sol it's two + + align:start position:0% +equation for a which I can Sol it's two + + + align:start position:0% +equation for a which I can Sol it's two +solutions and I don't yet know whether + + align:start position:0% +solutions and I don't yet know whether + + + align:start position:0% +solutions and I don't yet know whether +they're both okay and then back to find + + align:start position:0% +they're both okay and then back to find + + + align:start position:0% +they're both okay and then back to find +B in other words this leads to a and + + align:start position:0% + + + + align:start position:0% + +b and a similar discussion starting sort + + align:start position:0% +b and a similar discussion starting sort + + + align:start position:0% +b and a similar discussion starting sort +of symmetrically upwards would would + + align:start position:0% +of symmetrically upwards would would + + + align:start position:0% +of symmetrically upwards would would +lead to CND + + align:start position:0% +lead to CND + + + align:start position:0% +lead to CND +D and I believe that would they would + + align:start position:0% +D and I believe that would they would + + + align:start position:0% +D and I believe that would they would +then be right I I haven't even completed + + align:start position:0% +then be right I I haven't even completed + + + align:start position:0% +then be right I I haven't even completed +that that part but I think it would be + + align:start position:0% +that that part but I think it would be + + + align:start position:0% +that that part but I think it would be +so anyway that's a progress report that + + align:start position:0% +so anyway that's a progress report that + + + align:start position:0% +so anyway that's a progress report that +we now have equations that determine the + + align:start position:0% +we now have equations that determine the + + + align:start position:0% +we now have equations that determine the +ab c and d and we believe that when they + + align:start position:0% +ab c and d and we believe that when they + + + align:start position:0% +ab c and d and we believe that when they +determine the whole thing will have rank + + align:start position:0% +determine the whole thing will have rank + + + align:start position:0% +determine the whole thing will have rank +two and then + + align:start position:0% +two and then + + + align:start position:0% +two and then +we're uh I can't say often run + + align:start position:0% +we're uh I can't say often run + + + align:start position:0% +we're uh I can't say often run +because + + align:start position:0% +because + + + align:start position:0% +because +uh I don't have a general pattern there + + align:start position:0% + + + + align:start position:0% + +so still uh much to much to think + + align:start position:0% +so still uh much to much to think + + + align:start position:0% +so still uh much to much to think +through + + align:start position:0% +through + + + align:start position:0% +through +here I do want to so that that that's + + align:start position:0% +here I do want to so that that that's + + + align:start position:0% +here I do want to so that that that's +that's uh just I I just thought you + + align:start position:0% +that's uh just I I just thought you + + + align:start position:0% +that's uh just I I just thought you +might like to + + align:start position:0% +might like to + + + align:start position:0% +might like to +see three things about this problem + + align:start position:0% +see three things about this problem + + + align:start position:0% +see three things about this problem +in the rank one case you saw how a final + + align:start position:0% +in the rank one case you saw how a final + + + align:start position:0% +in the rank one case you saw how a final +theorem looks how how a proof + + align:start position:0% + + + + align:start position:0% + +could do do do the whole job and what a + + align:start position:0% +could do do do the whole job and what a + + + align:start position:0% +could do do do the whole job and what a +proof consisted of in this case you see + + align:start position:0% +proof consisted of in this case you see + + + align:start position:0% +proof consisted of in this case you see +uh theorem in progress where one case is + + align:start position:0% +uh theorem in progress where one case is + + + align:start position:0% +uh theorem in progress where one case is +clear we've now puzzled out another case + + align:start position:0% +clear we've now puzzled out another case + + + align:start position:0% +clear we've now puzzled out another case +but but in our heads we have the we know + + align:start position:0% +but but in our heads we have the we know + + + align:start position:0% +but but in our heads we have the we know +the job is all cases and we're not going + + align:start position:0% +the job is all cases and we're not going + + + align:start position:0% +the job is all cases and we're not going +to get all cases by by uh exhaustion the + + align:start position:0% +to get all cases by by uh exhaustion the + + + align:start position:0% +to get all cases by by uh exhaustion the +only way we can get it is eventually to + + align:start position:0% +only way we can get it is eventually to + + + align:start position:0% +only way we can get it is eventually to +see a pattern here and we don't see it + + align:start position:0% +see a pattern here and we don't see it + + + align:start position:0% +see a pattern here and we don't see it +yet and now + + align:start position:0% +yet and now + + + align:start position:0% +yet and now +thirdly I just want to say because it + + align:start position:0% +thirdly I just want to say because it + + + align:start position:0% +thirdly I just want to say because it +wouldn't have happened except for this + + align:start position:0% +wouldn't have happened except for this + + + align:start position:0% +wouldn't have happened except for this +giving this + + align:start position:0% +giving this + + + align:start position:0% +giving this +course that do you remember that I made + + align:start position:0% +course that do you remember that I made + + + align:start position:0% +course that do you remember that I made +the remark that I about something I had + + align:start position:0% +the remark that I about something I had + + + align:start position:0% +the remark that I about something I had +not known that if I have a triagonal + + align:start position:0% + + + + align:start position:0% + +matrix and let's assume these are + + align:start position:0% +matrix and let's assume these are + + + align:start position:0% +matrix and let's assume these are +nonzeros so it's a triagonal matrix do + + align:start position:0% +nonzeros so it's a triagonal matrix do + + + align:start position:0% +nonzeros so it's a triagonal matrix do +you remember my remark about its + + align:start position:0% + + + + align:start position:0% + +inverse probably + + align:start position:0% +inverse probably + + + align:start position:0% +inverse probably +not I + + align:start position:0% +not I + + + align:start position:0% +not I +didn't so in the beginning of the course + + align:start position:0% +didn't so in the beginning of the course + + + align:start position:0% +didn't so in the beginning of the course +we had particular numbers twos and minus + + align:start position:0% +we had particular numbers twos and minus + + + align:start position:0% +we had particular numbers twos and minus +ones and we computed the inverse + + align:start position:0% +ones and we computed the inverse + + + align:start position:0% +ones and we computed the inverse +those those special matrices k and t and + + align:start position:0% +those those special matrices k and t and + + + align:start position:0% +those those special matrices k and t and +so on we we we actually found the + + align:start position:0% +so on we we we actually found the + + + align:start position:0% +so on we we we actually found the +inverse so I thought that was + + align:start position:0% +inverse so I thought that was + + + align:start position:0% +inverse so I thought that was +interesting then those inverses had a + + align:start position:0% +interesting then those inverses had a + + + align:start position:0% +interesting then those inverses had a +special form and then I read that that + + align:start position:0% +special form and then I read that that + + + align:start position:0% +special form and then I read that that +form is always there that and what was + + align:start position:0% +form is always there that and what was + + + align:start position:0% +form is always there that and what was +that form that form was that above the + + align:start position:0% +that form that form was that above the + + + align:start position:0% +that form that form was that above the +on and above the + + align:start position:0% + + + + align:start position:0% + +diagonal so for these + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +guys that that was rank + + align:start position:0% +guys that that was rank + + + align:start position:0% +guys that that was rank +one that was so that was the thing that + + align:start position:0% +one that was so that was the thing that + + + align:start position:0% +one that was so that was the thing that +the inverse of a triagonal matrix has + + align:start position:0% +the inverse of a triagonal matrix has + + + align:start position:0% +the inverse of a triagonal matrix has +low rank above the diagonal so above the + + align:start position:0% +low rank above the diagonal so above the + + + align:start position:0% +low rank above the diagonal so above the +diagonal here it's of the form UI * + + align:start position:0% +diagonal here it's of the form UI * + + + align:start position:0% +diagonal here it's of the form UI * +VJ this is the the the in the IJ entry + + align:start position:0% +VJ this is the the the in the IJ entry + + + align:start position:0% +VJ this is the the the in the IJ entry +of the this is T for tri diagonal it's + + align:start position:0% +of the this is T for tri diagonal it's + + + align:start position:0% +of the this is T for tri diagonal it's +inverse the igj entry has its form UI VJ + + align:start position:0% +inverse the igj entry has its form UI VJ + + + align:start position:0% +inverse the igj entry has its form UI VJ +and let's suppose it's symmetric then it + + align:start position:0% +and let's suppose it's symmetric then it + + + align:start position:0% +and let's suppose it's symmetric then it +has low rank above the diagonal it + + align:start position:0% +has low rank above the diagonal it + + + align:start position:0% +has low rank above the diagonal it +doesn't have low rank overall so this is + + align:start position:0% +doesn't have low rank overall so this is + + + align:start position:0% +doesn't have low rank overall so this is +this is a different question from from + + align:start position:0% +this is a different question from from + + + align:start position:0% +this is a different question from from +the completion we were trying to + + align:start position:0% +the completion we were trying to + + + align:start position:0% +the completion we were trying to +complete to have low rank for the whole + + align:start position:0% +complete to have low rank for the whole + + + align:start position:0% +complete to have low rank for the whole +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +here the thing's invertible the rank is + + align:start position:0% +here the thing's invertible the rank is + + + align:start position:0% +here the thing's invertible the rank is +full the rank is n but but half of it + + align:start position:0% +full the rank is n but but half of it + + + align:start position:0% +full the rank is n but but half of it +has low rank and the other half + + align:start position:0% +has low rank and the other half + + + align:start position:0% +has low rank and the other half +has has uh entries by by symmetry they + + align:start position:0% +has has uh entries by by symmetry they + + + align:start position:0% +has has uh entries by by symmetry they +must be + + align:start position:0% +must be + + + align:start position:0% +must be +ujv and the total rank is n but the the + + align:start position:0% +ujv and the total rank is n but the the + + + align:start position:0% +ujv and the total rank is n but the the +interesting part was that and new to me + + align:start position:0% +interesting part was that and new to me + + + align:start position:0% +interesting part was that and new to me +was that half of it had rank one yeah I + + align:start position:0% +was that half of it had rank one yeah I + + + align:start position:0% +was that half of it had rank one yeah I +jumped in a question + + align:start position:0% +jumped in a question + + + align:start position:0% +jumped in a question +Lex in his work on noise showed that I'm + + align:start position:0% +Lex in his work on noise showed that I'm + + + align:start position:0% +Lex in his work on noise showed that I'm +not sure where he got it from okay that + + align:start position:0% +not sure where he got it from okay that + + + align:start position:0% +not sure where he got it from okay that +if you take a correlation + + align:start position:0% +if you take a correlation + + + align:start position:0% +if you take a correlation +the + + align:start position:0% +the + + + align:start position:0% +the +absolute okay take a correlation which + + align:start position:0% +absolute okay take a correlation which + + + align:start position:0% +absolute okay take a correlation which +is like this all right yes on the right + + align:start position:0% +is like this all right yes on the right + + + align:start position:0% +is like this all right yes on the right +okay then you get the inverse when you + + align:start position:0% +okay then you get the inverse when you + + + align:start position:0% +okay then you get the inverse when you +do the inverse the correlation comes out + + align:start position:0% +do the inverse the correlation comes out + + + align:start position:0% +do the inverse the correlation comes out +as triagonal okay so there was a + + align:start position:0% +as triagonal okay so there was a + + + align:start position:0% +as triagonal okay so there was a +specific case of importance right and + + align:start position:0% +specific case of importance right and + + + align:start position:0% +specific case of importance right and +and these cases that we did were + + align:start position:0% +and these cases that we did were + + + align:start position:0% +and these cases that we did were +specific cases of importance and I had + + align:start position:0% +specific cases of importance and I had + + + align:start position:0% +specific cases of importance and I had +no idea that sort of this was always + + align:start position:0% +no idea that sort of this was always + + + align:start position:0% +no idea that sort of this was always +happened that uh that uh uh if you had + + align:start position:0% +happened that uh that uh uh if you had + + + align:start position:0% +happened that uh that uh uh if you had +rank one here then the on the other side + + align:start position:0% +rank one here then the on the other side + + + align:start position:0% +rank one here then the on the other side +you had Tri diagonal if you have rank + + align:start position:0% +you had Tri diagonal if you have rank + + + align:start position:0% +you had Tri diagonal if you have rank +two here above the diagonal what do you + + align:start position:0% +two here above the diagonal what do you + + + align:start position:0% +two here above the diagonal what do you +figure then this one will be five + + align:start position:0% +figure then this one will be five + + + align:start position:0% +figure then this one will be five +diagonal so I guess + + align:start position:0% +diagonal so I guess + + + align:start position:0% +diagonal so I guess +now I'm I'm I'm sort of looking for a + + align:start position:0% +now I'm I'm I'm sort of looking for a + + + align:start position:0% +now I'm I'm I'm sort of looking for a +general law there I I I I guess I'm not + + align:start position:0% +general law there I I I I guess I'm not + + + align:start position:0% +general law there I I I I guess I'm not +looking so the the general law is then + + align:start position:0% +looking so the the general law is then + + + align:start position:0% +looking so the the general law is then +known that if we have rank five here + + align:start position:0% +known that if we have rank five here + + + align:start position:0% +known that if we have rank five here +then we then I mean it's a big Matrix + + align:start position:0% +then we then I mean it's a big Matrix + + + align:start position:0% +then we then I mean it's a big Matrix +say rank five above the diagonal + + align:start position:0% +say rank five above the diagonal + + + align:start position:0% +say rank five above the diagonal +completed by symmetry so it'll have the + + align:start position:0% +completed by symmetry so it'll have the + + + align:start position:0% +completed by symmetry so it'll have the +thing will have full rank but the other + + align:start position:0% +thing will have full rank but the other + + + align:start position:0% +thing will have full rank but the other +side the inverse will if I said rank + + align:start position:0% +side the inverse will if I said rank + + + align:start position:0% +side the inverse will if I said rank +five there then it would have one two + + align:start position:0% +five there then it would have one two + + + align:start position:0% +five there then it would have one two +three four five diagonals above the main + + align:start position:0% +three four five diagonals above the main + + + align:start position:0% +three four five diagonals above the main +diagonal and Five Below okay fine what + + align:start position:0% +diagonal and Five Below okay fine what + + + align:start position:0% +diagonal and Five Below okay fine what +do you mean by rank above the Diagon + + align:start position:0% +do you mean by rank above the Diagon + + + align:start position:0% +do you mean by rank above the Diagon +well good question that's what led to + + align:start position:0% +well good question that's what led to + + + align:start position:0% +well good question that's what led to +that's what led us to this crazy stuff + + align:start position:0% +that's what led us to this crazy stuff + + + align:start position:0% +that's what led us to this crazy stuff +what do I mean by rank above the + + align:start position:0% +what do I mean by rank above the + + + align:start position:0% +what do I mean by rank above the +diagonal well I certainly mean that that + + align:start position:0% +diagonal well I certainly mean that that + + + align:start position:0% +diagonal well I certainly mean that that +it if it has the form UI VJ do you who + + align:start position:0% +it if it has the form UI VJ do you who + + + align:start position:0% +it if it has the form UI VJ do you who +asked the question yeah uh I mean I I + + align:start position:0% +asked the question yeah uh I mean I I + + + align:start position:0% +asked the question yeah uh I mean I I +identify immediately a matrix that's + + align:start position:0% +identify immediately a matrix that's + + + align:start position:0% +identify immediately a matrix that's +what I mean by having rank one above the + + align:start position:0% +what I mean by having rank one above the + + + align:start position:0% +what I mean by having rank one above the +diagonal if it if it has a form UI VJ + + align:start position:0% +diagonal if it if it has a form UI VJ + + + align:start position:0% +diagonal if it if it has a form UI VJ +that means it has the form of + + align:start position:0% +that means it has the form of + + + align:start position:0% +that means it has the form of +column you know it it it uh um it's + + align:start position:0% +column you know it it it uh um it's + + + align:start position:0% +column you know it it it uh um it's +that's one column of of uh + + align:start position:0% +that's one column of of uh + + + align:start position:0% +that's one column of of uh +U's U1 U2 u3 times a row of V's V1 V2 V3 + + align:start position:0% +U's U1 U2 u3 times a row of V's V1 V2 V3 + + + align:start position:0% +U's U1 U2 u3 times a row of V's V1 V2 V3 +the entry in that would be UI + + align:start position:0% +the entry in that would be UI + + + align:start position:0% +the entry in that would be UI +VJ and it's a it's a rank one it's a + + align:start position:0% +VJ and it's a it's a rank one it's a + + + align:start position:0% +VJ and it's a it's a rank one it's a +column times a row so I I recognize that + + align:start position:0% +column times a row so I I recognize that + + + align:start position:0% +column times a row so I I recognize that +as a rank one Matrix and I'm seeing it + + align:start position:0% +as a rank one Matrix and I'm seeing it + + + align:start position:0% +as a rank one Matrix and I'm seeing it +here in different uh + + align:start position:0% +here in different uh + + + align:start position:0% +here in different uh +notation so that's what I mean by rank + + align:start position:0% +notation so that's what I mean by rank + + + align:start position:0% +notation so that's what I mean by rank +one Matrix if I completed the whole + + align:start position:0% +one Matrix if I completed the whole + + + align:start position:0% +one Matrix if I completed the whole +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +by this pattern I would have rank one + + align:start position:0% +by this pattern I would have rank one + + + align:start position:0% +by this pattern I would have rank one +but symmetry completes it with the + + align:start position:0% +but symmetry completes it with the + + + align:start position:0% +but symmetry completes it with the +opposite pattern and and gives me full + + align:start position:0% +opposite pattern and and gives me full + + + align:start position:0% +opposite pattern and and gives me full +Rank and yeah yeah so that would be the + + align:start position:0% +Rank and yeah yeah so that would be the + + + align:start position:0% +Rank and yeah yeah so that would be the +rank one case yes all right here here's + + align:start position:0% +rank one case yes all right here here's + + + align:start position:0% +rank one case yes all right here here's +my + + align:start position:0% +my + + + align:start position:0% +my +idea here's my idea okay algebra is + + align:start position:0% +idea here's my idea okay algebra is + + + align:start position:0% +idea here's my idea okay algebra is +saying that if we have a certain number + + align:start position:0% +saying that if we have a certain number + + + align:start position:0% +saying that if we have a certain number +of diagonals here we have a certain rank + + align:start position:0% +of diagonals here we have a certain rank + + + align:start position:0% +of diagonals here we have a certain rank +here + + align:start position:0% +here + + + align:start position:0% +here +fine can't beat that okay now + + align:start position:0% +fine can't beat that okay now + + + align:start position:0% +fine can't beat that okay now +but I think there must be behind that + + align:start position:0% +but I think there must be behind that + + + align:start position:0% +but I think there must be behind that +somehow a more general rule that if + + align:start position:0% +somehow a more general rule that if + + + align:start position:0% +somehow a more general rule that if +the if the thing is approximately a band + + align:start position:0% +the if the thing is approximately a band + + + align:start position:0% +the if the thing is approximately a band +Matrix now what does that mean if it + + align:start position:0% +Matrix now what does that mean if it + + + align:start position:0% +Matrix now what does that mean if it +tails off fast you see what I want to do + + align:start position:0% +tails off fast you see what I want to do + + + align:start position:0% +tails off fast you see what I want to do +now is generalize this + + align:start position:0% +now is generalize this + + + align:start position:0% +now is generalize this +to when these are not necessarily + + align:start position:0% +to when these are not necessarily + + + align:start position:0% +to when these are not necessarily +strictly zero and this has strict rank + + align:start position:0% +strictly zero and this has strict rank + + + align:start position:0% +strictly zero and this has strict rank +whatever but I wanted to see it's sort + + align:start position:0% +whatever but I wanted to see it's sort + + + align:start position:0% +whatever but I wanted to see it's sort +of like Heisenberg somehow if this tails + + align:start position:0% +of like Heisenberg somehow if this tails + + + align:start position:0% +of like Heisenberg somehow if this tails +off fast then this has pretty close to + + align:start position:0% +off fast then this has pretty close to + + + align:start position:0% +off fast then this has pretty close to +rank one there's my there's my + + align:start position:0% +rank one there's my there's my + + + align:start position:0% +rank one there's my there's my +conjecture that if I if that that if + + align:start position:0% +conjecture that if I if that that if + + + align:start position:0% +conjecture that if I if that that if +these are + + align:start position:0% +these are + + + align:start position:0% +these are +little then the rank here is near one + + align:start position:0% +little then the rank here is near one + + + align:start position:0% +little then the rank here is near one +okay what does that + + align:start position:0% +okay what does that + + + align:start position:0% +okay what does that +mean I suppose it means that I have a + + align:start position:0% +mean I suppose it means that I have a + + + align:start position:0% +mean I suppose it means that I have a +rank one Matrix plus something small so + + align:start position:0% +rank one Matrix plus something small so + + + align:start position:0% +rank one Matrix plus something small so +there's my conjecture uh unwi ly stated + + align:start position:0% +there's my conjecture uh unwi ly stated + + + align:start position:0% +there's my conjecture uh unwi ly stated +here and imprecisely stated but you see + + align:start position:0% +here and imprecisely stated but you see + + + align:start position:0% +here and imprecisely stated but you see +that the you see it's reasonable right + + align:start position:0% +that the you see it's reasonable right + + + align:start position:0% +that the you see it's reasonable right +and if it's reasonable it's probably + + align:start position:0% +and if it's reasonable it's probably + + + align:start position:0% +and if it's reasonable it's probably +true and and if it's probably true it's + + align:start position:0% +true and and if it's probably true it's + + + align:start position:0% +true and and if it's probably true it's +probably been proved that's the bad + + align:start position:0% +probably been proved that's the bad + + + align:start position:0% +probably been proved that's the bad +point but uh um so that'd be my guess + + align:start position:0% +point but uh um so that'd be my guess + + + align:start position:0% +point but uh um so that'd be my guess +that if I have a matrix that's almost a + + align:start position:0% +that if I have a matrix that's almost a + + + align:start position:0% +that if I have a matrix that's almost a +band Matrix then its inverse is almost + + align:start position:0% +band Matrix then its inverse is almost + + + align:start position:0% +band Matrix then its inverse is almost +um uh a rank almost a low rank uh above + + align:start position:0% +um uh a rank almost a low rank uh above + + + align:start position:0% +um uh a rank almost a low rank uh above +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +above the diagonal okay stated that way + + align:start position:0% +above the diagonal okay stated that way + + + align:start position:0% +above the diagonal okay stated that way +it sounds like it's pretty clear so I + + align:start position:0% +it sounds like it's pretty clear so I + + + align:start position:0% +it sounds like it's pretty clear so I +have no idea + + align:start position:0% +have no idea + + + align:start position:0% +have no idea +uh uh whether that that idea whether + + align:start position:0% +uh uh whether that that idea whether + + + align:start position:0% +uh uh whether that that idea whether +whether that concept will be it it may + + align:start position:0% +whether that concept will be it it may + + + align:start position:0% +whether that concept will be it it may +be not not difficult to to pin down but + + align:start position:0% +be not not difficult to to pin down but + + + align:start position:0% +be not not difficult to to pin down but +it's uh it's it's sort of the step from + + align:start position:0% +it's uh it's it's sort of the step from + + + align:start position:0% +it's uh it's it's sort of the step from +algebra to + + align:start position:0% +algebra to + + + align:start position:0% +algebra to +analysis it's algebra when you're + + align:start position:0% +analysis it's algebra when you're + + + align:start position:0% +analysis it's algebra when you're +talking about strict zeros and strict + + align:start position:0% +talking about strict zeros and strict + + + align:start position:0% +talking about strict zeros and strict +rank analysis is when you get you get + + align:start position:0% +rank analysis is when you get you get + + + align:start position:0% +rank analysis is when you get you get +things like near zero and near rank then + + align:start position:0% +things like near zero and near rank then + + + align:start position:0% +things like near zero and near rank then +then it's estimates of uh inequalities + + align:start position:0% +then it's estimates of uh inequalities + + + align:start position:0% +then it's estimates of uh inequalities +you're bounding things and that's sort + + align:start position:0% +you're bounding things and that's sort + + + align:start position:0% +you're bounding things and that's sort +of the difference between those two + + align:start position:0% +of the difference between those two + + + align:start position:0% +of the difference between those two +parts of + + align:start position:0% +parts of + + + align:start position:0% +parts of +mathematics so and most people are sort + + align:start position:0% +mathematics so and most people are sort + + + align:start position:0% +mathematics so and most people are sort +of on one in one side or the other + + align:start position:0% +of on one in one side or the other + + + align:start position:0% +of on one in one side or the other +algebraists are just just have that + + align:start position:0% +algebraists are just just have that + + + align:start position:0% +algebraists are just just have that +Knack of playing with um with um + + align:start position:0% + + + + align:start position:0% + +combinations and Analysis is more about + + align:start position:0% +combinations and Analysis is more about + + + align:start position:0% +combinations and Analysis is more about +uh if you're given certain bounds on + + align:start position:0% +uh if you're given certain bounds on + + + align:start position:0% +uh if you're given certain bounds on +something what else what what bounds do + + align:start position:0% +something what else what what bounds do + + + align:start position:0% +something what else what what bounds do +those imply on other things okay I'm + + align:start position:0% +those imply on other things okay I'm + + + align:start position:0% +those imply on other things okay I'm +I've taken more than an hour of on this + + align:start position:0% +I've taken more than an hour of on this + + + align:start position:0% +I've taken more than an hour of on this +lecture and uh let's make this + + align:start position:0% +lecture and uh let's make this + + + align:start position:0% +lecture and uh let's make this +then can we take a break and I'm happy + + align:start position:0% +then can we take a break and I'm happy + + + align:start position:0% +then can we take a break and I'm happy +to to uh + + align:start position:0% +to to uh + + + align:start position:0% +to to uh +and and also so I'm going to call this + + align:start position:0% +and and also so I'm going to call this + + + align:start position:0% +and and also so I'm going to call this +then + + align:start position:0% +then + + + align:start position:0% +then +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +32 will + + align:start position:0% +32 will + + + align:start position:0% +32 will +be concentrate on Game Theory and + + align:start position:0% +be concentrate on Game Theory and + + + align:start position:0% +be concentrate on Game Theory and +um apologize to for + + align:start position:0% +um apologize to for + + + align:start position:0% +um apologize to for +for for a work in progress like that but + + align:start position:0% +for for a work in progress like that but + + + align:start position:0% +for for a work in progress like that but +maybe at Lector 31 when I feel I know + + align:start position:0% +maybe at Lector 31 when I feel I know + + + align:start position:0% +maybe at Lector 31 when I feel I know +you all so well uh you forgive me for uh + + align:start position:0% +you all so well uh you forgive me for uh + + + align:start position:0% +you all so well uh you forgive me for uh +describing something that's incomplete + + align:start position:0% +describing something that's incomplete + + + align:start position:0% +describing something that's incomplete +but uh um but connected to what we've + + align:start position:0% +but uh um but connected to what we've + + + align:start position:0% +but uh um but connected to what we've +been doing okay so + + align:start position:0% +been doing okay so + + + align:start position:0% +been doing okay so +uh comput uh okay you're going at this + + align:start position:0% +uh comput uh okay you're going at this + + + align:start position:0% +uh comput uh okay you're going at this +very hard does it have app why why okay + + align:start position:0% +very hard does it have app why why okay + + + align:start position:0% +very hard does it have app why why okay +why all right fair question right and + + align:start position:0% +why all right fair question right and + + + align:start position:0% +why all right fair question right and +and um what's my + + align:start position:0% +and um what's my + + + align:start position:0% +and um what's my +answer + + align:start position:0% +answer + + + align:start position:0% +answer +well just it's really you're really + + align:start position:0% +well just it's really you're really + + + align:start position:0% +well just it's really you're really +seeing what a mathematician who sort of + + align:start position:0% +seeing what a mathematician who sort of + + + align:start position:0% +seeing what a mathematician who sort of +on the border of pure and + + align:start position:0% + + + + align:start position:0% + +applied what happens I mean uh so so I + + align:start position:0% +applied what happens I mean uh so so I + + + align:start position:0% +applied what happens I mean uh so so I +yes I do hope it has applications and + + align:start position:0% +yes I do hope it has applications and + + + align:start position:0% +yes I do hope it has applications and +and I guess in this final minute here I + + align:start position:0% +and I guess in this final minute here I + + + align:start position:0% +and I guess in this final minute here I +was describing + + align:start position:0% +was describing + + + align:start position:0% +was describing +applica my my coming back to + + align:start position:0% +applica my my coming back to + + + align:start position:0% +applica my my coming back to +Applications cuz cuz a a lot of matrices + + align:start position:0% +Applications cuz cuz a a lot of matrices + + + align:start position:0% +Applications cuz cuz a a lot of matrices +a lot of matrices in in applications are + + align:start position:0% +a lot of matrices in in applications are + + + align:start position:0% +a lot of matrices in in applications are +big on the diagonal and and tail off + + align:start position:0% +big on the diagonal and and tail off + + + align:start position:0% +big on the diagonal and and tail off +talking being bad limited yes that + + align:start position:0% +talking being bad limited yes that + + + align:start position:0% +talking being bad limited yes that +that's right yeah that that exactly I + + align:start position:0% +that's right yeah that that exactly I + + + align:start position:0% +that's right yeah that that exactly I +mean that that's another word that falls + + align:start position:0% +mean that that's another word that falls + + + align:start position:0% +mean that that's another word that falls +into this thing so diagonally dominant + + align:start position:0% +into this thing so diagonally dominant + + + align:start position:0% +into this thing so diagonally dominant +is a is a and and people so you meet a + + align:start position:0% +is a is a and and people so you meet a + + + align:start position:0% +is a is a and and people so you meet a +lot of diagonally dominant matrices that + + align:start position:0% +lot of diagonally dominant matrices that + + + align:start position:0% +lot of diagonally dominant matrices that +they make your life easier and um + + align:start position:0% +they make your life easier and um + + + align:start position:0% +they make your life easier and um +because somehow they're they're better + + align:start position:0% +because somehow they're they're better + + + align:start position:0% +because somehow they're they're better +matrices to deal with they might they're + + align:start position:0% +matrices to deal with they might they're + + + align:start position:0% +matrices to deal with they might they're +probably positive definite because that + + align:start position:0% +probably positive definite because that + + + align:start position:0% +probably positive definite because that +diagonal is so tough that it that it uh + + align:start position:0% +diagonal is so tough that it that it uh + + + align:start position:0% +diagonal is so tough that it that it uh +makes a thing positive definite but then + + align:start position:0% +makes a thing positive definite but then + + + align:start position:0% +makes a thing positive definite but then +you want to say why what what what's the + + align:start position:0% +you want to say why what what what's the + + + align:start position:0% +you want to say why what what what's the +consequence in the inverse yeah so so + + align:start position:0% +consequence in the inverse yeah so so + + + align:start position:0% +consequence in the inverse yeah so so +maybe at this point I'm thinking of + + align:start position:0% +maybe at this point I'm thinking of + + + align:start position:0% +maybe at this point I'm thinking of +applied here but over here it's pure fun + + align:start position:0% +applied here but over here it's pure fun + + + align:start position:0% +applied here but over here it's pure fun +right I mean yeah who knows there could + + align:start position:0% +right I mean yeah who knows there could + + + align:start position:0% +right I mean yeah who knows there could +be an application but I don't require + + align:start position:0% +be an application but I don't require + + + align:start position:0% +be an application but I don't require +that to get excited about it that's + + align:start position:0% +that to get excited about it that's + + + align:start position:0% +that to get excited about it that's +that's the that's the reality I just + + align:start position:0% +that's the that's the reality I just + + + align:start position:0% +that's the that's the reality I just +require a puzzle that I can't see the + + align:start position:0% +require a puzzle that I can't see the + + + align:start position:0% +require a puzzle that I can't see the +way the end to yeah all right good okay \ No newline at end of file diff --git a/5L4QfjbK87M.txt b/5L4QfjbK87M.txt new file mode 100644 index 0000000000000000000000000000000000000000..ac41170ac1f3b0ef6833b23d00b414135502cda8 --- /dev/null +++ b/5L4QfjbK87M.txt @@ -0,0 +1,2828 @@ +align:start position:0% + +let's do our check + + align:start position:0% +let's do our check + + + align:start position:0% +let's do our check +um so main + + align:start position:0% + + + + align:start position:0% + +check + + align:start position:0% +check + + + align:start position:0% +check +if integral of Si star of XT KN SI XT + + align:start position:0% +if integral of Si star of XT KN SI XT + + + align:start position:0% +if integral of Si star of XT KN SI XT +KN DX is equal to 1 at T = to T as we + + align:start position:0% +KN DX is equal to 1 at T = to T as we + + + align:start position:0% +KN DX is equal to 1 at T = to T as we +say that + + align:start position:0% +say that + + + align:start position:0% +say that +there + + align:start position:0% +there + + + align:start position:0% +there +then it must + + align:start position:0% + + + + align:start position:0% + +hold for later times T greater than + + align:start position:0% +hold for later times T greater than + + + align:start position:0% +hold for later times T greater than +T this is what we want to check or + + align:start position:0% +T this is what we want to check or + + + align:start position:0% +T this is what we want to check or +verify or prove now to do it + + align:start position:0% +verify or prove now to do it + + + align:start position:0% +verify or prove now to do it +uh we're going to take our time so it's + + align:start position:0% +uh we're going to take our time so it's + + + align:start position:0% +uh we're going to take our time so it's +not going to happen in five minutes not + + align:start position:0% +not going to happen in five minutes not + + + align:start position:0% +not going to happen in five minutes not +10 minutes um maybe not even half an + + align:start position:0% +10 minutes um maybe not even half an + + + align:start position:0% +10 minutes um maybe not even half an +hour + + align:start position:0% +hour + + + align:start position:0% +hour +um not because it's so difficult it's + + align:start position:0% +um not because it's so difficult it's + + + align:start position:0% +um not because it's so difficult it's +because there's so many things that one + + align:start position:0% +because there's so many things that one + + + align:start position:0% +because there's so many things that one +can say in between that teach you a lot + + align:start position:0% +can say in between that teach you a lot + + + align:start position:0% +can say in between that teach you a lot +about quantum mechanics so we're going + + align:start position:0% +about quantum mechanics so we're going + + + align:start position:0% +about quantum mechanics so we're going +to take our time here um so we're going + + align:start position:0% +to take our time here um so we're going + + + align:start position:0% +to take our time here um so we're going +to first + + align:start position:0% + + + + align:start position:0% + +uh rewrite it with better notation so + + align:start position:0% +uh rewrite it with better notation so + + + align:start position:0% +uh rewrite it with better notation so +we'll + + align:start position:0% + + + + align:start position:0% + +Define row of x and t which is going to + + align:start position:0% +Define row of x and t which is going to + + + align:start position:0% +Define row of x and t which is going to +be called a + + align:start position:0% + + + + align:start position:0% + +probability + + align:start position:0% + + + + align:start position:0% + +density and it's nothing else than what + + align:start position:0% +density and it's nothing else than what + + + align:start position:0% +density and it's nothing else than what +you would expect P star of x and t * P + + align:start position:0% +you would expect P star of x and t * P + + + align:start position:0% +you would expect P star of x and t * P +of x and + + align:start position:0% + + + + align:start position:0% + +t it's a probability + + align:start position:0% +t it's a probability + + + align:start position:0% +t it's a probability +density U you know that that has the + + align:start position:0% +density U you know that that has the + + + align:start position:0% +density U you know that that has the +right interpretation is s + + align:start position:0% +right interpretation is s + + + align:start position:0% +right interpretation is s +squared and that's the kind of thing + + align:start position:0% +squared and that's the kind of thing + + + align:start position:0% +squared and that's the kind of thing +that integrated over space gives you the + + align:start position:0% +that integrated over space gives you the + + + align:start position:0% +that integrated over space gives you the +total probability so this is a positive + + align:start position:0% +total probability so this is a positive + + + align:start position:0% +total probability so this is a positive +number given by this quantity is called + + align:start position:0% +number given by this quantity is called + + + align:start position:0% +number given by this quantity is called +the probability density fine what do we + + align:start position:0% +the probability density fine what do we + + + align:start position:0% +the probability density fine what do we +know about this probability density that + + align:start position:0% +know about this probability density that + + + align:start position:0% +know about this probability density that +uh that we're trying to find about its + + align:start position:0% +uh that we're trying to find about its + + + align:start position:0% +uh that we're trying to find about its +integral so Define next n of T to be the + + align:start position:0% +integral so Define next n of T to be the + + + align:start position:0% +integral so Define next n of T to be the +integral of row of x and t + + align:start position:0% + + + + align:start position:0% + +DX integrate this probability density + + align:start position:0% +DX integrate this probability density + + + align:start position:0% +DX integrate this probability density +throughout + + align:start position:0% +throughout + + + align:start position:0% +throughout +space and that's going to give you n of + + align:start position:0% +space and that's going to give you n of + + + align:start position:0% +space and that's going to give you n of +T now what do we know we know + + align:start position:0% +T now what do we know we know + + + align:start position:0% +T now what do we know we know +that n of t or let's assume that n of T + + align:start position:0% +that n of t or let's assume that n of T + + + align:start position:0% +that n of t or let's assume that n of T +KN is equal to 1 + + align:start position:0% +KN is equal to 1 + + + align:start position:0% +KN is equal to 1 +n is that normalization it's that total + + align:start position:0% +n is that normalization it's that total + + + align:start position:0% +n is that normalization it's that total +integral of the probability what had to + + align:start position:0% +integral of the probability what had to + + + align:start position:0% +integral of the probability what had to +be equal to one well let's + + align:start position:0% +be equal to one well let's + + + align:start position:0% +be equal to one well let's +assume n at T not is equal to 1 that's + + align:start position:0% +assume n at T not is equal to 1 that's + + + align:start position:0% +assume n at T not is equal to 1 that's +good the question is will the shringer + + align:start position:0% + + + + align:start position:0% + +equation + + align:start position:0% + + + + align:start position:0% + +guarantee that and here's the claim the + + align:start position:0% +guarantee that and here's the claim the + + + align:start position:0% +guarantee that and here's the claim the +d + + align:start position:0% +d + + + align:start position:0% +d +n + + align:start position:0% +n + + + align:start position:0% +n +DT is equal to + + align:start position:0% + + + + align:start position:0% + +zero will the Shing equation guarantee + + align:start position:0% + + + + align:start position:0% + +this if the shinger equation guarantees + + align:start position:0% +this if the shinger equation guarantees + + + align:start position:0% +this if the shinger equation guarantees +that this derivative is indeed zero then + + align:start position:0% +that this derivative is indeed zero then + + + align:start position:0% +that this derivative is indeed zero then +we're in in good business because uh the + + align:start position:0% +we're in in good business because uh the + + + align:start position:0% +we're in in good business because uh the +derivative is zero the value is one we + + align:start position:0% +derivative is zero the value is one we + + + align:start position:0% +derivative is zero the value is one we +remain One Forever yes ask why you + + align:start position:0% +remain One Forever yes ask why you + + + align:start position:0% +remain One Forever yes ask why you +specify for T greater than T + + align:start position:0% +specify for T greater than T + + + align:start position:0% +specify for T greater than T +um well I don't have to specify for T + + align:start position:0% +um well I don't have to specify for T + + + align:start position:0% +um well I don't have to specify for T +greater than T not I could do it uh for + + align:start position:0% +greater than T not I could do it uh for + + + align:start position:0% +greater than T not I could do it uh for +all T different than T not but uh I say + + align:start position:0% + + + + align:start position:0% + +it I I say it this way as imagining that + + align:start position:0% +it I I say it this way as imagining that + + + align:start position:0% +it I I say it this way as imagining that +somebody prepared the system at some + + align:start position:0% +somebody prepared the system at some + + + align:start position:0% +somebody prepared the system at some +time T not and maybe the system didn't + + align:start position:0% +time T not and maybe the system didn't + + + align:start position:0% +time T not and maybe the system didn't +exist for other times below now if a + + align:start position:0% +exist for other times below now if a + + + align:start position:0% +exist for other times below now if a +system existed for a long time and you + + align:start position:0% +system existed for a long time and you + + + align:start position:0% +system existed for a long time and you +look at it at T not then certainly the + + align:start position:0% +look at it at T not then certainly the + + + align:start position:0% +look at it at T not then certainly the +sheringer equation should imply that uh + + align:start position:0% +sheringer equation should imply that uh + + + align:start position:0% +sheringer equation should imply that uh +it works later and it works before so so + + align:start position:0% +it works later and it works before so so + + + align:start position:0% +it works later and it works before so so +it's not really necessary but U no loss + + align:start position:0% +it's not really necessary but U no loss + + + align:start position:0% +it's not really necessary but U no loss +of + + align:start position:0% + + + + align:start position:0% + +generality + + align:start position:0% +generality + + + align:start position:0% +generality +okay so does it will it guarantee that + + align:start position:0% +okay so does it will it guarantee that + + + align:start position:0% +okay so does it will it guarantee that +well that's our thing to do so let's + + align:start position:0% +well that's our thing to do so let's + + + align:start position:0% +well that's our thing to do so let's +begin the work by doing a little bit of + + align:start position:0% +begin the work by doing a little bit of + + + align:start position:0% +begin the work by doing a little bit of +a + + align:start position:0% +a + + + align:start position:0% +a +calculation and uh and so what do we + + align:start position:0% +calculation and uh and so what do we + + + align:start position:0% +calculation and uh and so what do we +need to do we need to find the + + align:start position:0% +need to do we need to find the + + + align:start position:0% +need to do we need to find the +derivative of this + + align:start position:0% +derivative of this + + + align:start position:0% +derivative of this +quantity so what is this derivative of n + + align:start position:0% +quantity so what is this derivative of n + + + align:start position:0% +quantity so what is this derivative of n +d n + + align:start position:0% +d n + + + align:start position:0% +d n +DT would be the + + align:start position:0% +DT would be the + + + align:start position:0% +DT would be the +integral + + align:start position:0% +integral + + + align:start position:0% +integral +DDT of + + align:start position:0% +DDT of + + + align:start position:0% +DDT of +row of x and + + align:start position:0% + + + + align:start position:0% + +t + + align:start position:0% +t + + + align:start position:0% +t +DX so I went here and brought in the + + align:start position:0% +DX so I went here and brought in the + + + align:start position:0% +DX so I went here and brought in the +DDT which became a partial derivative + + align:start position:0% +DDT which became a partial derivative + + + align:start position:0% +DDT which became a partial derivative +because out this is just a function of T + + align:start position:0% +because out this is just a function of T + + + align:start position:0% +because out this is just a function of T +but inside here there's a function of t + + align:start position:0% +but inside here there's a function of t + + + align:start position:0% +but inside here there's a function of t +and a function of X so I must make clear + + align:start position:0% +and a function of X so I must make clear + + + align:start position:0% +and a function of X so I must make clear +that I'm just differentiating + + align:start position:0% +that I'm just differentiating + + + align:start position:0% +that I'm just differentiating +T so is DDT of row and now we can write + + align:start position:0% +T so is DDT of row and now we can write + + + align:start position:0% +T so is DDT of row and now we can write +it as integral + + align:start position:0% +it as integral + + + align:start position:0% +it as integral +DX what is row is p star P so we would + + align:start position:0% +DX what is row is p star P so we would + + + align:start position:0% +DX what is row is p star P so we would +have DDT of P + + align:start position:0% +have DDT of P + + + align:start position:0% +have DDT of P +star time + + align:start position:0% +star time + + + align:start position:0% +star time +P plus SI + + align:start position:0% +P plus SI + + + align:start position:0% +P plus SI +star DDT of + + align:start position:0% + + + + align:start position:0% + +P + + align:start position:0% + + + + align:start position:0% + +okay and here you see if you were + + align:start position:0% +okay and here you see if you were + + + align:start position:0% +okay and here you see if you were +waiting for that um that the shinger + + align:start position:0% +waiting for that um that the shinger + + + align:start position:0% +waiting for that um that the shinger +equation has to be necessary because we + + align:start position:0% +equation has to be necessary because we + + + align:start position:0% +equation has to be necessary because we +have deep side DT and uh that + + align:start position:0% +have deep side DT and uh that + + + align:start position:0% +have deep side DT and uh that +information is there with the shinger + + align:start position:0% +information is there with the shinger + + + align:start position:0% +information is there with the shinger +equation so + + align:start position:0% +equation so + + + align:start position:0% +equation so +let's do that so what do we have I Bar D + + align:start position:0% +let's do that so what do we have I Bar D + + + align:start position:0% +let's do that so what do we have I Bar D +DT equal + + align:start position:0% + + + + align:start position:0% + +H we'll write it like that for the time + + align:start position:0% +H we'll write it like that for the time + + + align:start position:0% +H we'll write it like that for the time +being without copying all what H is that + + align:start position:0% +being without copying all what H is that + + + align:start position:0% +being without copying all what H is that +would take a lot of + + align:start position:0% + + + + align:start position:0% + +time and uh from this + + align:start position:0% +time and uh from this + + + align:start position:0% +time and uh from this +equation you can find immediately that + + align:start position:0% +equation you can find immediately that + + + align:start position:0% +equation you can find immediately that +deep s + + align:start position:0% +deep s + + + align:start position:0% +deep s +DT is + + align:start position:0% +DT is + + + align:start position:0% +DT is +minus I over H + + align:start position:0% +minus I over H + + + align:start position:0% +minus I over H +bar + + align:start position:0% + + + + align:start position:0% + +H now we need to compx conjugate this + + align:start position:0% +H now we need to compx conjugate this + + + align:start position:0% +H now we need to compx conjugate this +equation and that it's always a little + + align:start position:0% +equation and that it's always a little + + + align:start position:0% +equation and that it's always a little +more + + align:start position:0% + + + + align:start position:0% + +scary but + + align:start position:0% +scary but + + + align:start position:0% +scary but +um in + + align:start position:0% + + + + align:start position:0% + +fact it's um actually the way to do it + + align:start position:0% +fact it's um actually the way to do it + + + align:start position:0% +fact it's um actually the way to do it +is in a way that you never get into + + align:start position:0% +is in a way that you never get into + + + align:start position:0% +is in a way that you never get into +scary or strange things so let me take + + align:start position:0% +scary or strange things so let me take + + + align:start position:0% +scary or strange things so let me take +the complex conjugate of this equation + + align:start position:0% +the complex conjugate of this equation + + + align:start position:0% +the complex conjugate of this equation +here I would have I goes to minus i h + + align:start position:0% +here I would have I goes to minus i h + + + align:start position:0% +here I would have I goes to minus i h +bar and now I would have let me go very + + align:start position:0% +bar and now I would have let me go very + + + align:start position:0% +bar and now I would have let me go very +slow D + + align:start position:0% +slow D + + + align:start position:0% +slow D +DT + + align:start position:0% +DT + + + align:start position:0% +DT +star + + align:start position:0% +star + + + align:start position:0% +star +equals and then I'll be simple minded + + align:start position:0% +equals and then I'll be simple minded + + + align:start position:0% +equals and then I'll be simple minded +here I think it's the + + align:start position:0% +here I think it's the + + + align:start position:0% +here I think it's the +best I'll just start the right hand + + align:start position:0% +best I'll just start the right hand + + + align:start position:0% +best I'll just start the right hand +side I start the left hand side and + + align:start position:0% +side I start the left hand side and + + + align:start position:0% +side I start the left hand side and +start the right hand + + align:start position:0% +start the right hand + + + align:start position:0% +start the right hand +side + + align:start position:0% +side + + + align:start position:0% +side +now here the complex conjugate of a + + align:start position:0% +now here the complex conjugate of a + + + align:start position:0% +now here the complex conjugate of a +derivative in this case I want to + + align:start position:0% +derivative in this case I want to + + + align:start position:0% +derivative in this case I want to +clarify what it is it's just the + + align:start position:0% +clarify what it is it's just the + + + align:start position:0% +clarify what it is it's just the +derivative of the complex conjugate so + + align:start position:0% +derivative of the complex conjugate so + + + align:start position:0% +derivative of the complex conjugate so +this is minus I bar DDT of size + + align:start position:0% + + + + align:start position:0% + +star equals H + + align:start position:0% + + + + align:start position:0% + +hat star that's + + align:start position:0% +hat star that's + + + align:start position:0% +hat star that's +fine and From Here If I multiply Again + + align:start position:0% +fine and From Here If I multiply Again + + + align:start position:0% +fine and From Here If I multiply Again +by I ided by H bar we get deep SI star + + align:start position:0% +by I ided by H bar we get deep SI star + + + align:start position:0% +by I ided by H bar we get deep SI star +DT is equal + + align:start position:0% +DT is equal + + + align:start position:0% +DT is equal +to I over H + + align:start position:0% +to I over H + + + align:start position:0% +to I over H +star H + + align:start position:0% +star H + + + align:start position:0% +star H +hat + + align:start position:0% +hat + + + align:start position:0% +hat +star okay + + align:start position:0% +star okay + + + align:start position:0% +star okay +this we + + align:start position:0% +this we + + + align:start position:0% +this we +obtain this useful formula and this + + align:start position:0% +obtain this useful formula and this + + + align:start position:0% +obtain this useful formula and this +useful formula and both go into our + + align:start position:0% +useful formula and both go into our + + + align:start position:0% +useful formula and both go into our +calculation of DN + + align:start position:0% +calculation of DN + + + align:start position:0% +calculation of DN +DT so what do we have here the N + + align:start position:0% +DT so what do we have here the N + + + align:start position:0% +DT so what do we have here the N +DT + + align:start position:0% +DT + + + align:start position:0% +DT +equals + + align:start position:0% +equals + + + align:start position:0% +equals +integral + + align:start position:0% +integral + + + align:start position:0% +integral +DX and I will put um an i over H bar I + + align:start position:0% +DX and I will put um an i over H bar I + + + align:start position:0% +DX and I will put um an i over H bar I +think + + align:start position:0% +think + + + align:start position:0% +think +here + + align:start position:0% + + + + align:start position:0% + +yes I over H + + align:start position:0% + + + + align:start position:0% + +bar look at this term + + align:start position:0% +bar look at this term + + + align:start position:0% +bar look at this term +first + + align:start position:0% +first + + + align:start position:0% +first +you have I over H bar H + + align:start position:0% + + + + align:start position:0% + +star p and the second term involves a d + + align:start position:0% +star p and the second term involves a d + + + align:start position:0% +star p and the second term involves a d +DT that comes with an opposite sign same + + align:start position:0% +DT that comes with an opposite sign same + + + align:start position:0% +DT that comes with an opposite sign same +factor of I over H bar so + + align:start position:0% +factor of I over H bar so + + + align:start position:0% +factor of I over H bar so +minus P + + align:start position:0% +minus P + + + align:start position:0% +minus P +star + + align:start position:0% +star + + + align:start position:0% +star +h + + align:start position:0% + + + + align:start position:0% + +s + + align:start position:0% + + + + align:start position:0% + +okay so uh the virtue of what we've done + + align:start position:0% +okay so uh the virtue of what we've done + + + align:start position:0% +okay so uh the virtue of what we've done +so far is that uh it doesn't look so bad + + align:start position:0% +so far is that uh it doesn't look so bad + + + align:start position:0% +so far is that uh it doesn't look so bad +yet and uh looks relatively clean and uh + + align:start position:0% +yet and uh looks relatively clean and uh + + + align:start position:0% +yet and uh looks relatively clean and uh +it's very suggestive actually so what's + + align:start position:0% +it's very suggestive actually so what's + + + align:start position:0% +it's very suggestive actually so what's +happening we want to show that DN DT is + + align:start position:0% +happening we want to show that DN DT is + + + align:start position:0% +happening we want to show that DN DT is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +now are we going to be able to show that + + align:start position:0% +now are we going to be able to show that + + + align:start position:0% +now are we going to be able to show that +simply that do a lot of algebra and say + + align:start position:0% +simply that do a lot of algebra and say + + + align:start position:0% +simply that do a lot of algebra and say +oh it's zero well it's kind of going to + + align:start position:0% +oh it's zero well it's kind of going to + + + align:start position:0% +oh it's zero well it's kind of going to +work that way but we're going to do the + + align:start position:0% +work that way but we're going to do the + + + align:start position:0% +work that way but we're going to do the +work and we're going to get to this DN + + align:start position:0% +work and we're going to get to this DN + + + align:start position:0% +work and we're going to get to this DN +DT being an integral of + + align:start position:0% +DT being an integral of + + + align:start position:0% +DT being an integral of +something and it's just not going to + + align:start position:0% +something and it's just not going to + + + align:start position:0% +something and it's just not going to +look like zero but it will be + + align:start position:0% +look like zero but it will be + + + align:start position:0% +look like zero but it will be +manipulated in such a way that you can + + align:start position:0% +manipulated in such a way that you can + + + align:start position:0% +manipulated in such a way that you can +argue it's zero using the boundary + + align:start position:0% +argue it's zero using the boundary + + + align:start position:0% +argue it's zero using the boundary +condition so it it's kind of interesting + + align:start position:0% +condition so it it's kind of interesting + + + align:start position:0% +condition so it it's kind of interesting +how it's going to work but here + + align:start position:0% +how it's going to work but here + + + align:start position:0% +how it's going to work but here +structurally you see what must happen + + align:start position:0% +structurally you see what must happen + + + align:start position:0% +structurally you see what must happen +for this calculation to succeed so we + + align:start position:0% +for this calculation to succeed so we + + + align:start position:0% +for this calculation to succeed so we +need for this to be + + align:start position:0% + + + + align:start position:0% + +zero be + + align:start position:0% +zero be + + + align:start position:0% +zero be +zero we + + align:start position:0% +zero we + + + align:start position:0% +zero we +need the following thing to happen the + + align:start position:0% +need the following thing to happen the + + + align:start position:0% +need the following thing to happen the +integral of a + + align:start position:0% +integral of a + + + align:start position:0% +integral of a +hat p + + align:start position:0% +hat p + + + align:start position:0% +hat p +star + + align:start position:0% +star + + + align:start position:0% +star +P be equal to the + + align:start position:0% +P be equal to the + + + align:start position:0% +P be equal to the +integral of P star + + align:start position:0% + + + + align:start position:0% + +H and I should write the + + align:start position:0% +H and I should write the + + + align:start position:0% +H and I should write the +DX's they are + + align:start position:0% + + + + align:start position:0% + +there so this would + + align:start position:0% +there so this would + + + align:start position:0% +there so this would +guarantee that d n DT is equal to zero + + align:start position:0% +guarantee that d n DT is equal to zero + + + align:start position:0% +guarantee that d n DT is equal to zero +so + + align:start position:0% +so + + + align:start position:0% +so +that's a very nice statement um and it's + + align:start position:0% +that's a very nice statement um and it's + + + align:start position:0% +that's a very nice statement um and it's +kind of nice is that right you have one + + align:start position:0% +kind of nice is that right you have one + + + align:start position:0% +kind of nice is that right you have one +function starred one function non + + align:start position:0% +function starred one function non + + + align:start position:0% +function starred one function non +starred once the H is with the function + + align:start position:0% +starred once the H is with the function + + + align:start position:0% +starred once the H is with the function +is to be starred but on the other side + + align:start position:0% +is to be starred but on the other side + + + align:start position:0% +is to be starred but on the other side +of the equation the H is on the other + + align:start position:0% +of the equation the H is on the other + + + align:start position:0% +of the equation the H is on the other +side so you've kind of moved the H from + + align:start position:0% +side so you've kind of moved the H from + + + align:start position:0% +side so you've kind of moved the H from +the complex conjugated function to the + + align:start position:0% +the complex conjugated function to the + + + align:start position:0% +the complex conjugated function to the +non-c complex conjugate function from + + align:start position:0% +non-c complex conjugate function from + + + align:start position:0% +non-c complex conjugate function from +the first function to the second + + align:start position:0% +the first function to the second + + + align:start position:0% +the first function to the second +function and that's a very nice thing to + + align:start position:0% +function and that's a very nice thing to + + + align:start position:0% +function and that's a very nice thing to +demand of the + + align:start position:0% +demand of the + + + align:start position:0% +demand of the +hamiltonian so actually what seems to be + + align:start position:0% +hamiltonian so actually what seems to be + + + align:start position:0% +hamiltonian so actually what seems to be +happening is that this conservation of + + align:start position:0% +happening is that this conservation of + + + align:start position:0% +happening is that this conservation of +probability will work if your + + align:start position:0% +probability will work if your + + + align:start position:0% +probability will work if your +hamiltonian is good enough to do + + align:start position:0% +hamiltonian is good enough to do + + + align:start position:0% +hamiltonian is good enough to do +something like + + align:start position:0% + + + + align:start position:0% + +this and uh this is a nice formula it's + + align:start position:0% +this and uh this is a nice formula it's + + + align:start position:0% +this and uh this is a nice formula it's +a famous formula + + align:start position:0% +a famous formula + + + align:start position:0% +a famous formula +um + + align:start position:0% +um + + + align:start position:0% +um +this thing holds this is + + align:start position:0% +this thing holds this is + + + align:start position:0% +this thing holds this is +true + + align:start position:0% +true + + + align:start position:0% +true +true if + + align:start position:0% +true if + + + align:start position:0% +true if +H is a Herm Mission + + align:start position:0% + + + + align:start position:0% + +Operator + + align:start position:0% + + + + align:start position:0% + +Operator so that's a very interesting + + align:start position:0% +Operator so that's a very interesting + + + align:start position:0% +Operator so that's a very interesting +new name that shows up that an operator + + align:start position:0% +new name that shows up that an operator + + + align:start position:0% +new name that shows up that an operator +being her missions + + align:start position:0% +being her missions + + + align:start position:0% +being her missions +so this is what I was promising you that + + align:start position:0% +so this is what I was promising you that + + + align:start position:0% +so this is what I was promising you that +we're going to do this and we're going + + align:start position:0% +we're going to do this and we're going + + + align:start position:0% +we're going to do this and we're going +to be learning all kinds of funny things + + align:start position:0% +to be learning all kinds of funny things + + + align:start position:0% +to be learning all kinds of funny things +as as it happens so what is it uh for a + + align:start position:0% +as as it happens so what is it uh for a + + + align:start position:0% +as as it happens so what is it uh for a +Herm Mission operator well a Herm + + align:start position:0% +Herm Mission operator well a Herm + + + align:start position:0% +Herm Mission operator well a Herm +Mission + + align:start position:0% +Mission + + + align:start position:0% +Mission +operator a Herm + + align:start position:0% + + + + align:start position:0% + +Mission + + align:start position:0% +Mission + + + align:start position:0% +Mission +H would actually satisfy the + + align:start position:0% +H would actually satisfy the + + + align:start position:0% +H would actually satisfy the +following actually + + align:start position:0% + + + + align:start position:0% + +satisfy that um the + + align:start position:0% +satisfy that um the + + + align:start position:0% +satisfy that um the +integral + + align:start position:0% +integral + + + align:start position:0% +integral +H SI + + align:start position:0% +H SI + + + align:start position:0% +H SI + + align:start position:0% + + + align:start position:0% +star size 2 is equal to the integral of + + align:start position:0% +star size 2 is equal to the integral of + + + align:start position:0% +star size 2 is equal to the integral of +P + + align:start position:0% +P + + + align:start position:0% +P + + align:start position:0% + + + + align:start position:0% + +star h + + align:start position:0% +star h + + + align:start position:0% +star h +2 so the an operator is said to be her + + align:start position:0% +2 so the an operator is said to be her + + + align:start position:0% +2 so the an operator is said to be her +Mission if you can move it from the + + align:start position:0% +Mission if you can move it from the + + + align:start position:0% +Mission if you can move it from the +first part to the second part in this + + align:start position:0% +first part to the second part in this + + + align:start position:0% +first part to the second part in this +sense and with two different + + align:start position:0% +sense and with two different + + + align:start position:0% +sense and with two different +functions so this should be possible to + + align:start position:0% +functions so this should be possible to + + + align:start position:0% +functions so this should be possible to +do if an operator is to be called her + + align:start position:0% + + + + align:start position:0% + +Mission now of course if it holds for + + align:start position:0% +Mission now of course if it holds for + + + align:start position:0% +Mission now of course if it holds for +two arbitrary function functions it + + align:start position:0% +two arbitrary function functions it + + + align:start position:0% +two arbitrary function functions it +holds when the two functions are the + + align:start position:0% +holds when the two functions are the + + + align:start position:0% +holds when the two functions are the +same and it's this case so what we need + + align:start position:0% +same and it's this case so what we need + + + align:start position:0% +same and it's this case so what we need +is a par case of the condition of + + align:start position:0% +is a par case of the condition of + + + align:start position:0% +is a par case of the condition of +hermiticity hermiticity means that the + + align:start position:0% +hermiticity hermiticity means that the + + + align:start position:0% +hermiticity hermiticity means that the +operator does this + + align:start position:0% + + + + align:start position:0% + +thing any two functions that you put + + align:start position:0% +thing any two functions that you put + + + align:start position:0% +thing any two functions that you put +here this equality is + + align:start position:0% +here this equality is + + + align:start position:0% +here this equality is +true now if you ask yourself how do I + + align:start position:0% +true now if you ask yourself how do I + + + align:start position:0% +true now if you ask yourself how do I +even understand that what allows me to + + align:start position:0% +even understand that what allows me to + + + align:start position:0% +even understand that what allows me to +move the H from one side to the other + + align:start position:0% +move the H from one side to the other + + + align:start position:0% +move the H from one side to the other +we'll see it very soon but it's the fact + + align:start position:0% +we'll see it very soon but it's the fact + + + align:start position:0% +we'll see it very soon but it's the fact +that H has second derivatives and maybe + + align:start position:0% +that H has second derivatives and maybe + + + align:start position:0% +that H has second derivatives and maybe +you can integrate them by parts and move + + align:start position:0% +you can integrate them by parts and move + + + align:start position:0% +you can integrate them by parts and move +the derivatives from the P one to the p + + align:start position:0% +the derivatives from the P one to the p + + + align:start position:0% +the derivatives from the P one to the p +2 and do all kinds of things but you + + align:start position:0% +2 and do all kinds of things but you + + + align:start position:0% +2 and do all kinds of things but you +should try to think at this moment + + align:start position:0% +should try to think at this moment + + + align:start position:0% +should try to think at this moment +structurally what kind of objects you + + align:start position:0% +structurally what kind of objects you + + + align:start position:0% +structurally what kind of objects you +have what kind of properties you have + + align:start position:0% +have what kind of properties you have + + + align:start position:0% +have what kind of properties you have +and the object are this + + align:start position:0% +and the object are this + + + align:start position:0% +and the object are this +operator that controls the time + + align:start position:0% +operator that controls the time + + + align:start position:0% +operator that controls the time +Evolution called the hamiltonian and if + + align:start position:0% +Evolution called the hamiltonian and if + + + align:start position:0% +Evolution called the hamiltonian and if +I want probability interpretation to + + align:start position:0% +I want probability interpretation to + + + align:start position:0% +I want probability interpretation to +make sense we need this equality which + + align:start position:0% +make sense we need this equality which + + + align:start position:0% +make sense we need this equality which +is a consequence of + + align:start position:0% +is a consequence of + + + align:start position:0% +is a consequence of +hermiticity + + align:start position:0% +hermiticity + + + align:start position:0% +hermiticity +now I'll maybe use a little this + + align:start position:0% +now I'll maybe use a little this + + + align:start position:0% +now I'll maybe use a little this +Blackboard haven't used it much before + + align:start position:0% +Blackboard haven't used it much before + + + align:start position:0% +Blackboard haven't used it much before +um in terms of uh Herm Mission operators + + align:start position:0% +um in terms of uh Herm Mission operators + + + align:start position:0% +um in terms of uh Herm Mission operators +I'm almost there with the definition of + + align:start position:0% +I'm almost there with the definition of + + + align:start position:0% +I'm almost there with the definition of +a Herm Mission operator I I haven't + + align:start position:0% +a Herm Mission operator I I haven't + + + align:start position:0% +a Herm Mission operator I I haven't +quite given it to you but let's let's + + align:start position:0% +quite given it to you but let's let's + + + align:start position:0% +quite given it to you but let's let's +state it given that we're already in + + align:start position:0% +state it given that we're already in + + + align:start position:0% +state it given that we're already in +this uh discussion of + + align:start position:0% +this uh discussion of + + + align:start position:0% +this uh discussion of +hermeticity + + align:start position:0% +hermeticity + + + align:start position:0% +hermeticity +so this is what is called a Herm Mission + + align:start position:0% +so this is what is called a Herm Mission + + + align:start position:0% +so this is what is called a Herm Mission +operator does that but in + + align:start position:0% +operator does that but in + + + align:start position:0% +operator does that but in +general in + + align:start position:0% + + + + align:start position:0% + +general right + + align:start position:0% + + + + align:start position:0% + +given an operator + + align:start position:0% +given an operator + + + align:start position:0% +given an operator +t + + align:start position:0% + + + + align:start position:0% + +t one + + align:start position:0% + + + + align:start position:0% + +defines its + + align:start position:0% + + + + align:start position:0% + +permission + + align:start position:0% + + + + align:start position:0% + +conjugate t dager as follows so you have + + align:start position:0% +conjugate t dager as follows so you have + + + align:start position:0% +conjugate t dager as follows so you have +the + + align:start position:0% +the + + + align:start position:0% +the +integral of P 1 + + align:start position:0% +integral of P 1 + + + align:start position:0% +integral of P 1 +star + + align:start position:0% + + + + align:start position:0% + +P2 and that must be rearranged until it + + align:start position:0% +P2 and that must be rearranged until it + + + align:start position:0% +P2 and that must be rearranged until it +looks like T + + align:start position:0% +looks like T + + + align:start position:0% +looks like T +dagger P + + align:start position:0% +dagger P + + + align:start position:0% +dagger P + + align:start position:0% + + + align:start position:0% +star p + + align:start position:0% +star p + + + align:start position:0% +star p +2 now these things of are the beginning + + align:start position:0% +2 now these things of are the beginning + + + align:start position:0% +2 now these things of are the beginning +of a + + align:start position:0% +of a + + + align:start position:0% +of a +whole set of ideas that are terribly + + align:start position:0% +whole set of ideas that are terribly + + + align:start position:0% +whole set of ideas that are terribly +important in quantum mechanics her + + align:start position:0% +important in quantum mechanics her + + + align:start position:0% +important in quantum mechanics her +Mission operators their igon values and + + align:start position:0% +Mission operators their igon values and + + + align:start position:0% +Mission operators their igon values and +igen vectors so it's going to take a + + align:start position:0% +igen vectors so it's going to take a + + + align:start position:0% +igen vectors so it's going to take a +little time for you to get accustomed to + + align:start position:0% +little time for you to get accustomed to + + + align:start position:0% +little time for you to get accustomed to +them but this is the beginning you will + + align:start position:0% +them but this is the beginning you will + + + align:start position:0% +them but this is the beginning you will +explore a little bit of these things in + + align:start position:0% +explore a little bit of these things in + + + align:start position:0% +explore a little bit of these things in +future homework and start getting + + align:start position:0% +future homework and start getting + + + align:start position:0% +future homework and start getting +familiar if now it looks very strange + + align:start position:0% +familiar if now it looks very strange + + + align:start position:0% +familiar if now it looks very strange +and UNM motivate that maybe um you will + + align:start position:0% +and UNM motivate that maybe um you will + + + align:start position:0% +and UNM motivate that maybe um you will +see that that will change soon even + + align:start position:0% +see that that will change soon even + + + align:start position:0% +see that that will change soon even +throughout the to today's + + align:start position:0% +throughout the to today's + + + align:start position:0% +throughout the to today's +lecture so this is the hermiss conjugate + + align:start position:0% +lecture so this is the hermiss conjugate + + + align:start position:0% +lecture so this is the hermiss conjugate +so you if you want to calculate the Herm + + align:start position:0% +so you if you want to calculate the Herm + + + align:start position:0% +so you if you want to calculate the Herm +missan conjugate you must start with + + align:start position:0% +missan conjugate you must start with + + + align:start position:0% +missan conjugate you must start with +this thing and start doing manipulations + + align:start position:0% +this thing and start doing manipulations + + + align:start position:0% +this thing and start doing manipulations +to clean up the p 2 have nothing act on + + align:start position:0% +to clean up the p 2 have nothing act on + + + align:start position:0% +to clean up the p 2 have nothing act on +p 2 everything acting on P one and that + + align:start position:0% +p 2 everything acting on P one and that + + + align:start position:0% +p 2 everything acting on P one and that +thing is called the dagger and then + + align:start position:0% +thing is called the dagger and then + + + align:start position:0% +thing is called the dagger and then +finally T is her + + align:start position:0% +finally T is her + + + align:start position:0% +finally T is her +mission + + align:start position:0% + + + + align:start position:0% + +if T dagger is equal to + + align:start position:0% +if T dagger is equal to + + + align:start position:0% +if T dagger is equal to +T so if it's her Mission conjugate is + + align:start position:0% +T so if it's her Mission conjugate is + + + align:start position:0% +T so if it's her Mission conjugate is +itself it's almost like people say a + + align:start position:0% +itself it's almost like people say a + + + align:start position:0% +itself it's almost like people say a +real number is a number whose complex + + align:start position:0% +real number is a number whose complex + + + align:start position:0% +real number is a number whose complex +conjugate is equal to itself so a Herm + + align:start position:0% +conjugate is equal to itself so a Herm + + + align:start position:0% +conjugate is equal to itself so a Herm +Mission op operator is one whose Herm + + align:start position:0% +Mission op operator is one whose Herm + + + align:start position:0% +Mission op operator is one whose Herm +Mission conjugate is equal to itself and + + align:start position:0% +Mission conjugate is equal to itself and + + + align:start position:0% +Mission conjugate is equal to itself and +you see if if T is her Mission well then + + align:start position:0% +you see if if T is her Mission well then + + + align:start position:0% +you see if if T is her Mission well then +it's back to T and T in both places + + align:start position:0% +it's back to T and T in both places + + + align:start position:0% +it's back to T and T in both places +which is what we've been saying here + + align:start position:0% +which is what we've been saying here + + + align:start position:0% +which is what we've been saying here +this is a hermiss + + align:start position:0% +this is a hermiss + + + align:start position:0% +this is a hermiss +operator \ No newline at end of file diff --git a/5uTd3WzQulo.txt b/5uTd3WzQulo.txt new file mode 100644 index 0000000000000000000000000000000000000000..13aff387eeb64db827c218cacbe8a699b456793c --- /dev/null +++ b/5uTd3WzQulo.txt @@ -0,0 +1,4338 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, interactive +teaching. + +Here is a famous graph produced +by Benjamin bloom and + +his students. + +So here on this axis is +student achievement. + +So after a course is +over, students are + +tested on the material. + +And here's their score. + +And this is the percentage +who attained each score. + +So here, they compared three +methods of teaching, but I'll + +just compare two. + +So one method is standard +one-group instruction, say + +one-to-30, or today, +maybe one-to-90. + +And here is the histogram, the +distribution of students' + +scores, nicely spread out. + +Now, by itself, it +doesn't say much. + +But what's really interesting is +the distribution base after + +the same amount of teaching, but +done in a tutorial form, + +with one-to-one or +maybe one-to-two. + +You can put some quantitative +figures on this + +from Bloom's results. + +The average-- + +so this is one-to-one +tutoring, one-to-30. + +The average tutorial student is +two sigmas better than the + +group students. + +In other words, the average +tutorial student is at the + +98th percentile of the ordinary +teaching group. + +So the question is-- + +the natural question is, how can +we make group instruction + +as effective as tutorial +instruction? + +As Benjamin Bloom says, he says, +finding such methods + +would be an educational +contribution of + +the greatest magnitude. + +Because, for example, +it would change our + +notions about human potential. + +We'd actually realize, oh, +actually, there's not that + +much innate in what +people can do. + +Most of it is how well they've +learned, how well + +they've been taught. + +So the great question-- + +and it's the title of Bloom's +paper-- is the search for + +methods of group instruction +as effective + +as one-to-one tutoring. + +To that end, let's think about +the following question, which + +is, what makes tutoring +so effective? + +So I'm going to ask you that, +to consider that question in + +groups of two and three, +whatever's sort of convenient + +in your region of the room. + +So, what makes tutoring +so effective? + +After you discuss, we'll take +reasons, put them on the + +board, and then I'll show you +methods of group instruction + +that may not quite get us all +the way to tutoring, but that + +answer many of the good +characteristics of tutoring + +and bring them into +group instruction. + +OK, so please find one +or two neighbors. + +Introduce yourselves. + +You never know. + +You might find a teaching +colleague. + +And think about what makes +tutoring so effective. + +OK, so take 30 seconds +and collect + +your thoughts together. + +OK, who would like to suggest +something that your group + +thought of? + +You don't necessarily have to +believe it, just something you + +discussed and think +we should share. + +Yes? + +Could you tell me your name? + +AUDIENCE: Elena. + +PROFESSOR: Elena. + +AUDIENCE: For one-on-one +tutoring, I imagine there's + +less time for misconceptions +to get + +ingrained in your brain. + +PROFESSOR: OK, you can nip +misconceptions in the bud. + +Whereas in, for example, group +instruction, you may not even + +know the students have +a misconception + +until the final exam. + +Then what do you do? + +OK, let's see. + +This group, could you +tell me your name? + +AUDIENCE: So we thought-- + +PROFESSOR: Could you +tell me your name? + +AUDIENCE: Eric. + +PROFESSOR: Eric. + +AUDIENCE: We thought in a group, +there's probably a lot + +of just dissemination +of information. + +And in one-on-one tutoring, it's +probably not one person + +just telling person two +a bunch of stuff. + +It's going through +exam problems. + +PROFESSOR: Right, OK. + +So the contrast in this is +what does the teaching + +situation look like? + +In a typical lecture, someone +may just talk at you for 50 + +minutes, whereas it's hard to +imagine a one-on-one tutorial + +situation where you walk in for +your tutorial, and they + +just talk at you +for 50 minutes. + +That would seem so odd and so +counter to all conventions of + +human discussion. + +It would take a really, really +disciplined and well-trained + +person to sit still for 50 +minutes for that kind of + +treatment, so not initially a +good kind of training either. + +OK, so I'll say you cannot +yammer at the audience for 50 + +minutes straight. + +Yes, can you tell +me your name? + +AUDIENCE: Sorry? + +PROFESSOR: Could you +tell me your name? + +AUDIENCE: I'm Whitney. + +PROFESSOR: Whitney + +AUDIENCE: I think it follows +from this discussion that + +arises between two people that +the student experiences + +validation of what they've +understood, and it helps build + +their confidence. + +PROFESSOR: OK, because they're +talking in a small group, so + +they can get validation +in a safe setting. + +Is that? + +OK, so it's safe. + +It's a safe setting for raising +ideas maybe that + +you're not sure about. + +OK, there was one more. + +Yeah, can you tell +me your name? + +AUDIENCE: Martin. + +PROFESSOR: Martin. + +AUDIENCE: Yeah. + +With tutoring, it's much easier +to identify exactly + +what the student has trouble +understanding, and then tailor + +the teaching according +to that. + +PROFESSOR: OK, so you can tailor +the teaching according + +to what you find out. + +So sort of like the new +electronic SATs. + +According to what you don't +know or do know, in each + +question, they give you +questions based on your + +previous answers at the right +level of difficulty. + +So you can tailor. + +Yeah, can you tell +me your name? + +AUDIENCE: Azrael. + +PROFESSOR: Azrael, yeah. + +AUDIENCE: I think related to +this, it's very valuable to be + +able to tailor your teaching +style to the student + +[INAUDIBLE] + +in general, not just specific +points [INAUDIBLE]. + +PROFESSOR: OK, you can +tailor the teaching + +style to the student. + +If, for example, the +student is-- + +for example, suppose you're +teaching math to somebody + +who's an architect. + +Well, you can use lots of +examples that are particular + +to something they're totally +fascinated by. + +You can tailor a teaching +method. + +OK, let me get something from +somewhere back there, in case + +I've been neglecting people +way in the back. + +Oh, go ahead. + +You guys had your chance. + +I'll be back. + +Can you tell me your name? + +AUDIENCE: Graham. + +PROFESSOR: Graham. + +AUDIENCE: Just the level of +engagement, it is impossible + +to sit there in a one-on-one +setting and think about the + +music you like [INAUDIBLE] + +the subject matter at hand. + +PROFESSOR: Right. + +OK, so the level of engagement +is much higher in a tutorial. + +So that's the complement +of this one. + +So the student engagement +is much higher. + +Yeah, just as it's hard for a +teacher in a tutorial setting + +to just talk for 50 minutes +straight, it's also hard for a + +student in a tutorial session to +surf the web for 50 minutes + +straight, or use their +BlackBerry or read the + +newspaper or whatever it may be +that the standard methods + +of lecture distraction are. + +Yes, can you tell +me your name? + +AUDIENCE: Question about +the conditions in these + +experiments. + +So normally in a university +setting in this country, + +tutoring is something that +students seek out for + +themselves. + +It's not something that's +provided in lieu of lecture. + +Was that the case in this? + +Was it really just that the same +material was covered in + +the same semester and they +just did it two different + +ways, and everybody had +to go to tutoring? + +PROFESSOR: Yeah, so what +they did was-- + +I don't think these were +university students. + +I think these were high +school and even + +grade school students. + +Yeah. + +But what they did was they +took the same number of + +teaching hours, and they either +taught them in lecture + +or they taught them in +tutorials, one-on-one, or I + +think sometimes one-on-two. + +AUDIENCE: So in both cases, they +were required to go to + +class, in a sense. + +PROFESSOR: Yeah. + +I mean, I don't know +if they actually + +went to the big class. + +But I'm sure they went to +the tutorial class. + +That's partly of one +of the differences. + +That's number six. + +Yes, way in the back. + +AUDIENCE: From experience, +I've found that you know + +students don't understand +something. + +You don't why until +you sit down. + +Usually you find there's some +gaping hole that's quite often + +easily plugged. + +PROFESSOR: OK. + +And how do you find that out? + +AUDIENCE: You start asking them, +what class did you have? + +What did you not understand? + +And sometimes they'll just +bubble [? right out, ?] + +I never got this one +key concept. + +PROFESSOR: OK, so you can ask +them questions, specific + +questions to figure out what +they don't know, to diagnose + +what they're confused about. + +OK, let's take one more, and +then I'll show you some + +methods that hopefully address +what these characteristics-- + +these missing characteristics +of group instruction. + +Yes? + +AUDIENCE: On one-on-one +tutoring, for the student who + +might not be as into the effort +[INAUDIBLE] added + +pressure, just feeling that +there are other people + +[INAUDIBLE] + +student, there's no feeling of +why I need to learn much more, + +[INAUDIBLE]. + +You don't really prepare +yourself for anyone else. + +PROFESSOR: Right, so the +method of teaching + +automatically adjusts to +whatever level the student is. + +So they're not comparing +to other people. + +They're are actually just +comparing to what they don't + +know right then. + +So let's just call it intrinsic +comparison with the + +knowledge, rather than extrinsic +with other students. + +OK, so there's less emotional +churn as a result of that. + +OK, so we could continue +this list, but this is + +an excellent start. + +So now, if we look through that +list, there's several + +themes that come out. + +I mean, it's hard in a group +setting to figure out what + +students don't know. + +It's hard to ask +them questions. + +It's hard to keep +people engaged. + +It's easy to just talk at +people as a teacher. + +So what can we do in group +teaching to capture as many + +characteristics of +this as we can? + +Well, I'll show you methods that +I divide into four time + +scales, ranging from +short to long. + +But before I do that, let me ask +if there are any questions + +on anything so far. + +OK. + +You were first. + +AUDIENCE: How is student +achievement measured? + +Is it just test scores? + +PROFESSOR: Yeah, that +was a test score. + +So what they did is, actually +they gave them a test. + +Like, if it was algebra, they +gave them an algebra test, and + +then tested them at the end, and +at the beginning too, just + +to see where they were +to start with. + +AUDIENCE: So were the lectures +more tailored to just teaching + +them algebra, and the tutoring +was specifically tailored to + +doing problems in algebra? + +PROFESSOR: Well, the tutoring +was whatever they needed to do + +well on the test. + +And the lecturing was hopefully + +designed that way too. + +But it had all the flaws of, you +want to teach so students + +will do well on your +final exam. + +But what do you do +when you have 30 + +diverse students in there? + +You had a question too. + +AUDIENCE: I was just wondering, +do we know which of + +these particular suggestions +are the most important, and + +which ones might be good? + +PROFESSOR: We have some idea. + +Good question. + +The question is which of these +is most important, and which + +is less important. + +Actually, they're all getting +at something similar. + +But there's a middle group in +there, actually, that they + +studied, which was +mastery learning. + +So mastery learning, it's just +like a programmed instruction. + +So the idea is that-- + +Keller Plan is another +word for it. + +So mastery learning is midway +between tutoring and group + +instruction. + +There was one sigma better, +so 84th percentile. + +So mastery learning, you don't +go on to the new topics until + +you pass the mastery exam +on the previous topic. + +So you're always building +on a solid foundation. + +And so you work until you can +pass the exam, and then you + +continue on. + +And just by adding that to group +instruction, you get one + +sigma better. + +So right away, diagnosing +misconceptions, you can see, + +is quite important. + +But there's still another +one sigma to get. + +And so that's, I think, +what all the rest of + +these items are about. + +And we do know a lot of stuff +about how people learn. + +One of it is questions. + +Questions are essential. + +So I'm going to talk +about that. + +But let me just ask again, +any questions? + +OK, good. + +This time it worked. + +So now, what did I do? + +So this is actually +the first method. + +So how long did I wait after +I said, any questions? + +Half a second? + +One minute? + +No, five seconds. + +So the first time, I didn't +wait five seconds, because + +actually a question came up a +little before five seconds. + +But this time, the second time, +I waited five seconds. + +Now, why is that? + +So that is the first method. + +When you ask a question-- + +for example, "any questions" +or "what do you think about + +this"-- wait five seconds. + +And I'll explain why +in a second. + +But, methods shortest +to longest. + +The reason I divide them by +shortest to longest is the + +shortest ones are +the easiest to + +incorporate into your teaching. + +So anytime you teach, if you +ask a question, wait five + +seconds, so the five-second +time scale. + +OK, so why do I wait +five seconds, + +and why not two seconds? + +Well, the reason is, think +about your audience. + +Suppose you're talking away at +them, and all the sudden you + +ask a question. + +Now, what are they hearing? + +So everyone's seen +Charlie Brown? + +So what does Charlie Brown hear +when he goes to school? + +Wah wah wah wah wah wah wah wah +wah wah wah wah, and all + +of a sudden that changes +and there's a question. + +It takes about a second to +realize that the wah wah wah + +has stopped, and you're being +asked a question. + +OK, so one second's gone. + +Let's call it that, the +thumb-- one second. + +Now, it takes about another +second to even figure out what + +the question is. + +Now you say, oh yeah, there's +a question being asked. + +What did they say? + +OK, maybe now let's say it's +one and a half seconds. + +So now we're at somewhere +between two and three seconds. + +Now it takes maybe one or two +more seconds to figure out + +what you're going to +say about that. + +Do I have any thoughts +about it? + +Do I actually have +any questions? + +Do I have a thought about the +thing they're asking me? + +Do I know what the band gap is +in silicon, whatever the + +question may be? + +So now we're somewhere between +four, maybe near five seconds. + +And then it maybe takes another +second to get the + +courage up to raise your hand +and be ready with a sentence. + +So now we're at least +five seconds. + +So if you don't wait those five +seconds, what you'll get + +is, you'll be getting a few +questions, but you'll get + +questions from people who +already thought about the + +material, in other words, the +people who are already at the + +98th percentile. + +But if you want to bring +everybody in, and get + +everybody thinking about it, +you really need to wait, so + +you don't get questions just +from the usual suspects. + +So wait five seconds. + +Now, the mechanism is +quite important. + +If you just say, OK I'm going +to wait five seconds, you'll + +go, any questions. + +Oh, done, five seconds is up. + +And you'll think five seconds +is up in about one second. + +And why is that? + +Well, you're up in front of a +whole bunch of people, and the + +adrenaline will be flowing. + +And adrenaline speeds +up your time sense. + +All those stories about people +who-- like mothers who saw + +their kid about to get hit by +the car, they race out and + +grab the kid and the +car keeps going. + +Maybe it screeches to a stop. + +They've managed to +rescue their kid. + +Well, they could act much faster +because adrenaline + +makes the time sense +much sharper. + +So your idea of five seconds +will be more like one second. + +There's another reason, which is +there's this mistaken idea + +that if you're not talking, +you're not teaching. + +So you're being paid to teach. + +And oh my god, you're +not saying anything. + +That means you must not +know something. + +So you feel insecure, and that +increases the adrenaline and + +only speeds up the time +problem more. + +So to wait five seconds, you +actually have to count it -- + +one 1,000, two 1,000, three +1,000, four 1,000, five 1,000. + +And I actually sometimes just +do it behind my back with my + +hand-- one 1,000, two +1,000, three 1,000, + +four 1,000, five 1,000. + +And it's not like you have to +be watching the audience for + +the whole five seconds. + +It's actually better to wait +the whole five seconds, and + +then choose one of the hands +that has gone up rather than + +the first hand that goes +up at two seconds. + +You say, oh, thank god, somebody +asked a question. + +OK, now my waiting is over. + +Well, again, you'll be back +in the usual suspect soup. + +So, first time scale for +bringing in questions, in + +other words, spreading the +engagement through the class. + +Because when people are asking +questions, they're by + +definition engaged. + +They're struggling with +the material. + +They're trying to make +it their own. + +Wait five seconds. + +OK, the next method. + +So the next method is short +time scale, one minute. + +And that is to use a feedback +sheet at the end of every + +teaching session. + +So you actually have an example +of a feedback sheet + +that we'll ask you to fill out +at the end of this session, + +which we handed out +at the beginning. + +And the blank versions of that +sheet will also be on the TLL + +website, so you can actually +download it, print it, and use + +it in your own teaching, +as well as my notes + +on how to use it. + +But the main point is that at +the end of the class, you give + +the students one or two +minutes to fill + +out a feedback sheet. + +And what I've converged on is +the following three questions + +on my feedback sheet, which is, +what was most confusing? + +Basically, what question +you have that + +still wasn't answered. + +Second question is, what was +the most useful or most + +useless example or demonstration +or teaching + +method that happened today? + +And the third question is, +any other comments? + +So now let me explain why I +use those three questions. + +The first question, these sheets +are all anonymous. + +And it's a chance for someone, +if they felt a little bit shy + +asking questions in front of +people-- so here in the + +tutorial, one of the +characteristics that was + +mentioned was that you don't +feel nervous about asking a + +question, because there's no +one there, or maybe there's + +one other person there. + +Whereas in a class of +30 or 80 or 20, you + +may feel a bit nervous. + +Well, if you feel a bit nervous, +you just put your + +question on the feedback +sheet. + +And so then at the beginning of +the next session, I answer + +all the questions on the +feedback sheets. + +So it takes me more than one +minute, but actually not that + +much longer. + +Because you could +flip through 100 + +sheets in about 10 minutes. + +You just glance through. + +You'll see a bunch of questions +are repeated. + +And you'll say, oh yeah, I do +really need to explain that. + +And at the beginning in the next +session, just explain all + +the important points. + +And that has another benefit, +which is that it links back to + +the previous lecture, or the +previous teaching session. + +So now you've made a thread +between the previous session + +and the current one, and you got +everyone up to speed into + +the space where you +want them to be. + +So that's why I use the +first question. + +The second question +is, what worked? + +What didn't work? + +And I also had to add, and tell +me whether it worked or + +didn't work. + +Because I used to get examples +saying, that example. + +And I didn't know whether they +loved it or hated it. + +So then I said, please +tell me the sign of + +the effect as well. + +And then I would know. + +I would start to build a model +of how students think and what + +works for them. + +So every time, basically, I +learned that I brought in a + +demonstration, there +was universal love + +on the second question. + +So I said, OK, that really +connects with students. + +And I would make sure +to do more of that. + +So it was reinforcement for me +and practice for me at being a + +better teacher. + +And what you'll find is that as +you use the sheet more and + +more, you get better and better +at predicting how + +students think. + +So for example, you're doing +some discussion on the board, + +some examples on derivation. + +And the first time you do it, +maybe you don't know it's not + +going to go well. + +And then you read the sheet and +you see, oh my god, I was + +a disaster. + +30 questions out of 80 all said, +I didn't understand x. + +So now you understand that +students didn't understand the + +way you did it. + +Well, now you've built +a better model of + +how students think. + +So next time you're doing a +derivation, what you'll find + +is-- at least what I've found +is in the middle of the + +derivation, I'll realize, oh, +this is not going well. + +I'm going to get a +lot of questions + +about this on the sheet. + +Oops, but it's to late. + +I'm in the middle of the soup. + +I can't un-drink the soup. + +So I just finish the soup and +just wait for the questions. + +But then after maybe another +week of using the sheet, you + +actually have quite a good +model of the students. + +And now before you start the +derivation or when you're + +planning the lecture, you +realize, oh yeah, that's not + +going to go well. + +Let me do it the other +way, because I + +know that works better. + +So you'll find your model of the +students developing more + +and more refinements and +more and more accuracy. + +In other words, you're becoming + +a more expert teacher. + +And then the third question +on the sheet + +is, any other comments? + +The reason for that is, it's +just a free-form space. + +And I've actually had students +say, oh, actually, when you + +explained that thing, you +actually explained it wrong. + +I was like, oh that's +good to know. + +So then in the beginning +of the-- + +because we did it properly in +this other class, and here's + +the exact reference that you +maybe didn't know about. + +I was like, oh great. + +So at the beginning of the next +class, I say, hey, one of + +you guys pointed out a mistake +I made, and here is the + +corrected version. + +And people might not be +willing to say that + +personally, because they say, +oh my god, I don't want to + +correct the professor and +make them feel stupid. + +But it's much easier to do +it on an anonymous sheet. + +So I get really useful +information on that. + +And sometimes you can figure out +who did it, so you could + +send an email saying, oh thanks, +that was useful. + +All right. + +[LAUGHTER] + +PROFESSOR: And it is. + +So you may think, oh no, you +don't want to be corrected. + +But actually, after you tell +the students the following + +enough, so it's again +back to this. + +In a group, students feel like, +oh my god, I don't want + +to make a mistake. + +So I give them the following +speech quite often. + +Because if you don't +make mistakes-- + +I tell them, look, how +much did you know + +when you were born? + +Not a hell of a lot. + +You couldn't talk. + +You couldn't hardly walk. + +Well, how do you learn stuff? + +Did you just all the sudden +start walking and talking? + +No. + +You mangled your grammar. + +You put "-ed" at the end of +every past participle, even + +though some don't have that. + +And eventually you sorted it +all out and you stood up + +straight and you walked. + +So basically, how +did you learn? + +By making mistakes. + +So the only way to learn +is to make mistakes. + +So if you don't make any +mistakes, you will learn-- + +you'll know as much at the start +of your class as at the + +end of the class. + +So you want to make mistakes. + +So I tell them that +a bunch of times. + +But if then I'm really +embarrassed about making + +mistakes, then I've defeated the +whole purpose of telling + +students that. + +So I actually thank them +whenever they point out + +something that I didn't +do right. + +OK, so that's the second +time scale. + +Now, the third time scale +is not that much longer. + +It's about, let's say, +four or five minutes. + +And it's a question which I'll +call a conceptual multiple + +choice question. + +And I'll give you an example. + +OK, so here is the question +that I'll use + +to illustrate it. + +Here is a pyramid with +a square base. + +And it's B by B. The length of +one side of the base is B. And + +the perpendicular height of +the pyramid is H. OK, so + +what's the volume? + +OK, so does everyone understand +the question? + +OK. + +Give it a try. + +Find your group or one or two. + +Any questions-- + +any confusions about +the question? + +Don't give me any answers just +yet, but any confusions about + +the question? + +OK, so find your groups of one +or two other people, and we'll + +discuss that question +in a couple minutes. + +Anyone want to say anything +about this? + +Is there a section I +haven't heard from? + +Yeah, go ahead. + +Can you just say your name? + +AUDIENCE: Brian. + +PROFESSOR: Brian, OK. + +So you like D but +not the others? + +OK, can you tell me, for +example, why you don't like A? + +AUDIENCE: Well, because all of +them just have the wrong + +proportionality. + +If B increases, then the square +is going to increase in + +area as B squared-- + +PROFESSOR: Ah, so you would +like that to B squared. + +AUDIENCE: Right. + +PROFESSOR: Whereas it's just a +single B and a single H. OK, + +so you don't like that because +the proportionality is wrong. + +It doesn't scale correctly. + +So let me put here, +bad scaling. + +What was another problem? + +AUDIENCE: It also has +the wrong units. + +PROFESSOR: It has bogus units. + +OK, so it has bogus +dimensions. + +AUDIENCE: [INAUDIBLE] +dimensions. + +PROFESSOR: No, they're pretty +much interchangeable. + +I use units to mean meters +or feet or something, and + +dimensions to be things +like length. + +But they're pretty much +interchangeable in usage. + +So bad scaling, bad +dimensions. + +OK, anyone have any +comments about B? + +AUDIENCE: Same. + +PROFESSOR: Same problem. + +In fact, it's even +more horrendous. + +Well, it starts out OK, I +mean, at least as far as + +dimensions are concerned. + +But then what does it do? + +This has the wrong dimensions. + +That has the right dimensions, +and then you add them. + +That's terrible. + +OK, so the dimensions +are just bogus. + +Ah, OK. + +Can anyone say anything +about choice C? + +Yeah? + +AUDIENCE: If you look at the +extremes, like if you make H + +very small-- + +PROFESSOR: So if you stop on +this pyramid and step on it + +until H goes to 0, what happens +to the volume here? + +It goes to infinity. + +Yeah, it's terrible. + +So the extreme cases +are just bogus. + +So it fails that test. + +OK, now we're back to +D. So who likes D? + +So we have a few people +who like D. + +[STUDENT CALLS OUT] + +[LAUGHTER] + +PROFESSOR: OK, go ahead. + +You don't like D. + +AUDIENCE: No, I don't like D. + +PROFESSOR: OK, why not? + +[LAUGHTER] + +AUDIENCE: It's the volume of +the box, which has a size + +[INAUDIBLE]. + +PROFESSOR: So this is the volume +of a box, in other + +words, if I had vertical +sides. + +So let me draw vertical +sides here. + +Right, so whereas the pyramid +has actually got to be less. + +Now, it's kind of mysterious +what this factor here should + +be, but it's definitely +less than 1. + +So this is comparison +with a box. + +So it has a good properties, +and it's a good answer. + +It's just not correct. + +But that's OK, because it's +important to realize what's + +good about it and what's +not good about it. + +So it satisfies the +extreme cases. + +It satisfies dimensions. + +It scales correctly. + +Like you pointed out, you want +B squared, because it's the + +area down there. + +So it's good. + +It's not all good. + +Let's call it good mostly. + +But as they say, a miss is as +good as a mile except in + +horseshoes and atom bombs. + +So good mostly, but +box comparison. + +OK, so let me cross this guy +out and this guy out + +and that guy out. + +So what do you conclude +from that? + +They're all wrong. + +So here's another multiple +choice question. + +[LAUGHTER] + +PROFESSOR: OK, so +who votes for A? + +One of these is definitely +correct. + +[LAUGHTER] + +PROFESSOR: No votes for A? + +Who votes for B? + +Oh, I'm hurt. + +I'm hurt. + +Well, B is in fact correct. + +[LAUGHTER] + +PROFESSOR: So every once in a +while, I throw the students a + +curve ball and make all +the choices wrong. + +Now, why would I do that, such +an evil, dastardly thing? + +Well, it's good every once +in a while to do that. + +In fact, I found that out +experimentally, because the + +first time I used this question +with the students, I + +was already using the +feedback sheets. + +And on the feedback sheets, I +got back tons of love on the + +comment sheets. + +The students said, oh, +we love that, having + +all the answers wrong. + +Don't do it too often, but do +it every once in a while, + +maybe once a month or so. + +And that way, they never know +when it's coming, so they + +always have to check +all the answers. + +They can't just do everything +by elimination. + +So it is a very useful +thing to do. + +There are other reasons for it +too, and if you're curious, + +ask me in the questions, +and I'll explain more + +reasons to do it. + +But that's already a +sufficient reason. + +OK, so that's method three. + +And you see you get a +bit of discussion. + +You get multiple choices. + +And what does that allow +you to do right away? + +Well, what was one +of the problems? + +Is, you can find out +what misconception + +students have early. + +Point one up there, in +a tutorial, you can + +ask students questions. + +Well, why not ask some +questions in + +a big lecture too? + +So that's what we just did. + +So you can find out. + +If 90% of the students get it +like that, you know you don't + +have to say much more +about the topic. + +But if the answers are +distributed at the monkey + +line, 25% for all the answers, +then you know there's going to + +be trouble. + +And it's worth actually +expanding on this point and + +the theme that question gets +across right then in lecture. + +So you could make it much more +tailored to the group of + +students you have. + +And the students also-- + +what happens in their +small groups? + +Right, so remember we mentioned +that in a tutorial, + +that it's a safe setting for +raising questions, whereas a + +big group might not be. + +Well, what have we done by +letting everyone work in + +groups of two or three? + +We've created a whole bunch of +safe settings for questions. + +So the students are free +to discuss in their + +groups of two or three. + +And if they can't resolve it +there, well then they feel + +pretty confident that it's +worthwhile sharing it with the + +whole class. + +Maybe the whole class +can learn something + +from that as well. + +And that has another benefit, +which is that it gets around + +the gender imbalance. + +So to illustrate this problem, +I was once in a + +bookstore in New York. + +And I was standing in the +computer section and this + +couple walked up the stairs. + +And the woman asked the +man, oh, there's some + +big fat book on Java. + +And she said, what's Java? + +And within a millisecond, not +batting an eyelid, he said, + +oh, it's the fastest search +engine on the internet, which + +is completely rubbish. + +[LAUGHTER] + +PROFESSOR: It's a programming +language. + +So it has absolutely nothing +to do with a search engine. + +I'm sure no search engine +is even written in Java. + +So it has nothing to do +with search engines. + +So it's a complete lie. + +But he said it so fast. + +So there's a dichotomy there, +which is-- generally speaking, + +it's called actually male +answer syndrome. + +And the women-- + +[LAUGHTER] + +PROFESSOR: I see all the women +laughing, or I hear all the + +women laughing. + +Well, what you'll find is +generally, men are very + +willing to talk about stuff +they know nothing about, + +speaking crudely in extreme +caricatures, whereas women are + +reluctant to talk about stuff +they even know about. + +So if you just ask a question to +a group just flat out, even + +with the five-second wait, +you're more likely to get + +responses from the guys +than from the girls. + +So the way to try to mitigate +that imbalance is to give + +people, first, a safe setting +for asking questions. + +And then people actually +calibrate to the correct level + +about, well, is this +a reasonable idea? + +Is this not a reasonable idea? + +Could the people around me +have good ideas about it? + +Is it resolved now? + +If + +Not, well, it's probably safe to +raise in a bigger setting. + +So you'll actually fix the +gender imbalance to a large + +extent, and balance it out. + +So it has lots of benefits +that you get + +from tutorial teaching. + +So now I'll show you the last +one, which we won't actually + +do for half an hour. + +But I want to sketch out how +you could do a question for + +half an hour. + +I'll show you the kind of +question that works in that + +time frame. + +So this could be multiple +choice. + +Doesn't have to be, but some +kind of conceptual question + +with lots of discussion. + +And often, it may have +a demonstration. + +So let me show you that +particular question. + +So I'm going to use-- + +I have these guys too, but I +also have the wood blocks + +which I like so much. + +So here are two wood blocks cut +for me by the machine shop + +of the Cambridge physics +department + +when I taught there. + +So they cut them out of the +same piece of pine, same + +grain, direction, everything. + +The only difference is this is +2 centimeters thick, and + +that's 1 centimeter thick. + +But They're both a foot long +and 5 centimeters wide. + +So what I'm going to do is I'm +going to tap this block, and + +you'll hear a note. + +[TAPS A NOTE ON WOOD BLOCK] + +PROFESSOR: Did everyone +hear the note? + +Great. + +OK, so now the question is, when +I tap this block, is the + +note going to be higher, the +same frequency, or lower? + +OK, so does everyone understand +the question? + +OK, so discuss with +your neighbors. + +We'll take a vote in about +a couple minutes. + +I won't give you the 10 minutes +I would normally give + +people to discuss and argue. + +We'll take a couple reasons, +then we'll do the experiment. + +OK, time to vote. + +So, just to sketch out how this +could actually turn into + +a 30-minute question, normally I +give students about a couple + +minutes to think on their own, +then take a vote, and then set + +everyone to argue +with each other. + +I say, in particular, find +someone who has a different + +answer than you, and try to +convince them of your answer. + +So then you get a big +argument going. + +And so then I let that go +for about 10 minutes. + +And then we take another vote. + +And then we discuss. + +So let's just imagine we've +skipped forward to the end of + +the group discussion, +and we're going to + +take the second vote. + +So who thinks the thick block +will have a higher frequency + +than the thin block? + +About maybe 20 people. + +Who thinks they'll be equal? + +About 25. + +Who thinks the thick block will +have a lower frequency? + +About 50. + +OK, so we have a good spread +of opinion there. + +So now, again, in the scenario +of the 30-minute question, I + +would ask for reasons, just like +I did here, and I would + +just be the scribe. + +I would just write down people's +reasons for A, B, or + +C, for greater, equal, +or less than. + +Just make sure I understand +the reason and + +then write it down. + +I don't have to agree +with the reason. + +Just make sure I understand it, +and the person who says it + +says, yeah, that's what +I'm trying to say. + +Write it on the board. + +Then give people the opportunity +to say a reason + +for any of the others or +against any of them, or + +comment on any reason already +on the board. + +And that can go for another +10 minutes or so, + +sometimes even longer. + +And then I ask people, OK, the +test of science is experiment. + +Should we do the experiment? + +Should we do the experiment? + +AUDIENCE: Yes. + +PROFESSOR: OK. + +So just to remind you +of the earlier tone. + +[TAPS A NOTE ON WOOD BLOCK] + +[TAPS A HIGHER NOTE +ON WOOD BLOCK] + +[LAUGHTER] + +PROFESSOR: So the +ayes have it. + +OK, so it turns out to be +roughly almost a factor of two + +higher in frequency, almost +a full octave. + +It's not quite. + +If they were infinitely thin, +and this were twice infinitely + +thin, it would be exactly +a factor of two. + +But because they have +a finite thickness, + +it's not quite true. + +But that's how xylophones +work. + +In fact, many people have +reasoned their way to the + +correct answer by thinking +about xylophones. + +And many people have reasoned +their way to the incorrect + +answer by thinking about guitar +strings, which brings + +up a very interesting discussion +you can have. + +So what did you notice +about here? + +When I was about to tap +the second one, could + +you hear a pin drop? + +[LAUGHTER] + +PROFESSOR: Right. + +Student engagement +is much higher, + +because people are involved. + +But the act of voting commits +people to a public view. + +And they want to know, is this +right or is this not right? + +And the act of voting has +another benefit, which is that + +you get a much better +error signal. + +Whereas, suppose you +didn't vote. + +And suppose you thought, well, +it could be higher because + +it's stiffer. + +On the other hand, it's bigger +wavelengths, so it's lower. + +And you sort of both reasons +in your head. + +You're in a superposition +state. + +And then the experiment +happens-- + +bing bing bing-- and it's +higher, and you say, oh yeah, + +I knew that. + +It was higher because it's +thicker and stiffer. + +So you think actually you +understood everything, but you + +didn't actually figure out, +well, which of these two + +reasons is right and why? + +Whereas if you have to publicly +commit to one answer, + +then you get a clearly defined +signal back about whether that + +answer was right or not. + +So it's very important to +make sure people vote. + +And at the same time, it's very +important to make sure + +people are not punished +for voting. + +So does it matter in my classes +whether people get the + +vote right or not? + +I just want them to vote. + +And so then I have to give my +speech about, it's better to + +be wrong than right. + +Question? + +AUDIENCE: So I've been in lots +of classes where the professor + +asks a question and waits a +few seconds for people to + +raise their hands. + +And by the time he's done or +she's done, there's a third of + +the class raising their hand, +and those the people who had + +their hands up first. + +So how do you actually +take that step? + +PROFESSOR: Sorry, could you tell +me what they're doing? + +They ask a question. + +AUDIENCE: They ask +a question-- + +PROFESSOR: Do they let the +whole class discuss it? + +AUDIENCE: Not necessarily. + +So that's what you're +saying is key here? + +PROFESSOR: Yeah, it's +really key to let + +the whole class discuss-- + +so the normal structure for a +long question like this one + +I'll do is I'll make +sure everyone + +understands the question. + +And then I'll let people think +by themselves for a minute or + +two, and take a vote after that, +a straw poll, I call it, + +so people don't feel +it's too weighty. + +The reason for that is +that people have + +different learning styles. + +And some people want to think +longer for themself, and some + +people want to just start +talking right away, so I want + +to give something +for everybody. + +And then after I take that vote, +that gives me an idea + +where the class is, and it gives +the class an idea of + +where they are, and who +has different views. + +And then they can start arguing +with each other. + +And so now they've had a lot of +time to actually check what + +they all think. + +So people will have had +arguments in their group that + +they can't resolve, so they're +very eager to actually share + +the argument. + +Whereas if you just ask the +question without giving people + +time to struggle with it, you're +basically wasting the + +effect of the question. + +AUDIENCE: So how do you decide +what level of difficulty for + +discussion? + +PROFESSOR: This is +a hard question. + +But it's so rich. + +It has so many things. + +I don't expect most people to +get the question right. + +In fact, when I ask this to +faculty in physics department, + +when I give physics teaching +seminars, most + +people get it wrong. + +I won't say all the places where +that's been true, but + +it's been at many universities +around the world. + +So I don't expect +people to get it + +right, and I don't care. + +The reason for it is that it +introduces so many ideas-- + +about, for example, spring +models of solids. + +We can use musical instruments +as analogies-- + +that I think it's worth +spending even a + +whole class on it. + +And in fact, one time somebody +said, well, but a xylophone, + +all the things are the +same thickness and + +they're just longer. + +How does that work? + +And I said, oh, I'm glad +you asked that. + +And I pulled out my daughter's +xylophone-- + +she has a baby xylophone-- + +from my backpack. + +And so we analyzed the xylophone +right there. + +So it leads to so many +interesting things that I'm + +willing to spend a whole +class on it. + +So that's how I decide +how much time + +to allocate to something. + +If it's a really core idea, +spend more time on it. + +And if it's peripheral, tend to +spend less time on it or do + +a really short question +on it, if at all. + +And then the difficulty-- + +I like to get questions, +ideally-- + +I mean, this one's different +just because it's so rich-- + +but ideally where students are +sort of at 60% correct + +thinking by themself, +maybe 65%, even 70%. + +Because even though they may be +right, that sounds like oh, + +they're mostly fine, +but they may not + +know why they're right. + +So then in the discussion they +can solidify their reasons and + +maybe get up to 80% or 90%. + +Whereas if you've got a question +where they're 30% + +correct to start with, and +that doesn't have other + +redeeming qualities like the +richness of it, you'll just + +propagate noise throughout the +system, and just basically + +wrong ideas will just spread all +over and you'll spend all + +your time correcting those. + +So I gauge the difficulty +based on + +trying to hit that mark. + +OK, so hopefully you've +seen, first of all, + +that tutorial teaching-- + +the main points from today-- + +is much more effective than +regular teaching as normally + +practiced because of these +characteristics-- + +generally questioning, feedback, +instant feedback and + +corrective feedback +right away. + +But through a series of methods, +you can bring many of + +the benefits of tutorial +teaching to your own large + +group teaching, which is the +kind of teaching that most of + +us will do, just for +cost reasons. + +So I wish you best of luck +in all your teaching. + +AUDIENCE: Can I just [? get ?] +one interesting statement? + +PROFESSOR: Sure. + +AUDIENCE: It's something to +think about, and faculty often + +have difficulty with this. + +There's probably a pretty high +correlation between the amount + +of information that you want +to get through to students, + +and the time that it +takes to do it. + +The more questions you ask, the +less you can get through + +the material. + +And this constant +questioning-- + +PROFESSOR: This constant +battle. + +AUDIENCE: What should I do? + +Should I just try to get this +much information because I + +want to ask lots of questions? + +Or do I want to get that much +information through, then I + +better not spend too much +time asking questions? + +It's a conundrum. + +I think asking questions is +just a phenomenal way of + +learning, but [INAUDIBLE]. + +PROFESSOR: Yeah, basically +we teach too much stuff. + +And that's the fundamental +problem. + +And so one solution to that is +to say, look, all the details, + +get it from a book. + +And in class, we're going to +do what you can't easily do + +from the book, which is +struggle, argue, reason, and + +correct those reasons. + +That's hard to do from a book. + +So you should use the class +time for something that's + +value added that you +can't do elsewhere. + +So good luck with that. + +Please take a minute to fill +out the feedback sheets. + +And as long as no one kicks us +out, I'll be here as long as + +people have questions. + +[? COMPUTER: Answers ?] + +from lecture seven to questions + +generated in lecture six. + +PROFESSOR: OK, so questions +from before. + +What are your suggestions for +someone teaching a course that + +they are not expert in at all, +you know, for the first time? + +So I'm a practical man. + +I know most people, when they're +teaching a course, + +teaching is not going +to be their life. + +I mean, it is for me, +but that's unusual. + +And if you love teaching, +that's great. + +But probably, your job will be +dependent on how much research + +you do or other activities like +department committees. + +And so you don't want to destroy +your whole career on + +your first course. + +By which I mean, just try to +survive your first course. + +Because what you could do the +first time you're teaching + +it-- so the answer +is, you need to + +somehow become an expert. + +If you want to teach it +differently and creatively and + +interestingly, you somehow +need to become an expert. + +Now, you could do that by +spending the whole summer + +before really figuring out the +material from scratch. + +And that probably in the long +term is a good thing. + +You'd probably find useful +results in your + +research from it. + +But probably you don't have +that summer to do that. + +And so what you need to do is +kill two birds with one stone + +and become an expert by teaching +it, in which case the + +best plan I would recommend is +just to teach it pretty much + +the regular way, with some + +interactive changes in lecture. + +But just follow the regular +plan, as much as it sticks in + +one's craw. + +Because in doing that, first +of all, you will + +be rocking the boat. + +So people will accept it +even if it's not great. + +And you'll become an +expert by the end. + +And then the next time you +teach it, you'll be OK. + +Then you you've done that summer +of thinking, but you've + +done it during the class. + +So it meant the first class +didn't go as well as it could. + +But it also meant you survived +and you could order material + +for your lab and all the +other things that + +you'd do in the summer. + +How do you-- + +so I like it when you emphasize +that it's OK to get + +the wrong answer. + +It's like with the wood blocks, +I mentioned how, + +mostly when I ask this of +physics professors too, people + +get it mostly wrong. + +And so I had another example of +that in Colorado, because I + +gave a talk using +the wood blocks. + +So how can you incorporate that +"it's OK to be wrong, as + +long as you learn" attitude +into class? + +One of the best ways is to +minimize the amount of + +grading, and the emphasis +given to grading. + +Grading, basically, as a +first approximation-- + +so if I just add two letters, +it's hard to avoid that. + +So grading, when you mark +someone and you tell them, + +bad, A B, C, D, well, the people +who are getting B's, + +C's, and D's, whatever the quote +bad grades are, you are + +actually shaming people. + +And in some ways, you are +degrading their psyche. + +So it's not healthy. + +So that is one of the political +barriers to + +educational change +is the importance + +that we give to grading. + +And I will talk about that +in the final session. + +You may think, oh what about +the people who get A's? + +Well, if you're giving A, +B, C's, and D's, the + +people who get A's. + +They may have struggled and were +thinking, oh my god, will + +I get an A? + +Will I get an A? + +Then they get an A. +So they go, phew. + +But still, they were nervous +about their learning the whole + +time instead of enjoying it +as much as they could. + +And second, there's also +studies, many studies, which + +show that when you reward people +for things they already + +enjoy-- this is totally +fascinating-- + +so when you reward people for +things they already enjoy + +doing, their enjoyment drops. + +So if you start paying people +for things that they would + +like doing anyway, then they +don't like it as much. + +And you [INAUDIBLE] everyday +examples of this. + +You know if you know anyone +who's a symphony orchestra + +player, they say, oh yeah, the +best way to start hating music + +is to be a professional +musician. + +They love music, and then they +had to do it for pay, in all + +of a sudden they don't like as +much anymore, not all of a + +sudden, but slowly. + +So there are many, many +studies about that-- + +motivation. + +So what you want to do really +is to find intrinsic + +motivation. + +And so the difference between +extrinsic and intrinsic + +motivation is fundamental. + +And what you want to try to do +is create the environment + +always where the motivation +is intrinsic, so that the + +questions are interesting. + +So what that means is you +don't want to use bad + +questions that people don't have +an interest in, and then + +force them to be interested +because you give them + +extrinsic motivation. + +That's a fundamental bad choice, +and then it's being + +solved with the fundamental +wrong approach. + +What do you need to do is rather +than do both of those, + +you say, OK, let me find +interesting questions that + +people care about. + +And then the intrinsic +motivation carries people + +through, whether they're +right or wrong. + +So that's why I like questions +like the wood block so much, + +because people are just +actually interested. + +They want to know. + +They say, oh, that's +a good question. + +I should know that. + +Oh, maybe I don't. + +OK, well maybe I'll +learn something. + +So the other part of that is, +if you notice, I didn't use + +clickers when we did +this question. + +Partly, it's because clickers +are expensive and you have a + +bunch of logistics to do, and +then you need probably some + +ludicrous Windows program to +receive the signals, and I + +haven't written the Linux +version for it. + +So there's all of +those issues. + +Those are, I would say, not +the fundamental issue. + +The fundamental issue with +clickers, why I don't like + +them, is that they make people +think they're being spied on. + +So even especially if you live +in a surveillance society, + +where actually all your phone +calls are being spied on, + +people might think, well when +you have clickers, you're + +being spied on to know whether +you got the right answer or + +not, and it's going to count +against you at some point. + +So I'm very happy with people +to just raise their hands. + +And that's, in a way, more +anonymous than a clicker that + +belongs to you. + +So there are ways of getting +around that with clickers. + +You can to have people trade +clickers so they know that the + +clickers are random. + +So you can do things +like that. + +But still, I like the informal +feel of, yeah, + +just raise your hand. + +Don't worry. + +It's a safe space in +the classroom. + +And I have to say that +a few times. + +But just raise your hand, +and don't worry. + +And I'm not spying on you. + +I don't care whether you get +the right answer or not. + +For example, with the wood +blocks, I expect most people + +to get the wrong answer. + +That's OK. + +We'll learn something +about it afterwards. + +So you do have to work at it, +but there are things you can + +do to keep the class +[? safe. ?] + +There are also things to do, +which is that never-- + +it's hard to remember how much +power you have as the + +instructor, and just +as someone in + +a position of authority. + +So I might have told you the +story from when I was a + +graduate student, but it's +worth telling again, if I + +haven't, which is that I was +giving a talk in a group + +meeting when I was a +graduate student. + +My adviser got frustrated +with me because I wasn't + +understanding some fundamental +point, actually about springs. + +So to demonstrate it, he kicked +the table at me and + +said, is this acting +like a spring? + +And I was so shocked. + +I was just mortified +for like two days. + +I just couldn't believe my +adviser had done that in front + +of everybody else, and thought +that I must be + +idiot and showed it. + +So then eventually my fellow +grad students said, well, + +actually he does that only +when you really cares. + +So that's better than people +just switching off. + +So I sort of consoled +myself with that. + +But it did make a real strong +impression on me, how much + +even a small push from someone +in authority can do. + +So it's the same thing in +lecture, if when someone says + +something wrong, if you +say, oh, why would + +you have said that? + +Even the slightest hint of that, +people magnify and will + +pick up and be very, +very sensitive to. + +So you have to be really, +really, really careful not to + +let that happen. + +So one way is the poker face. + +So I practiced the poker face. + +So when people are making +suggestions, for example, + +about the wood block, why they +would act one way or another, + +I just make sure I get in a +different mental state. + +The mental state is +transcription. + +So I just want to make +sure I understand + +what people are saying. + +And then I just write +that down. + +Now, it's even there you +have to be careful. + +Because you'll understand the +correct answer quicker than + +you will the incorrect answer. + +So you have to make sure when +people are explaining the + +correct answer, you don't +complete it for them. + +And then in contrast, when +people are explaining a wrong + +answer, you ask lots of +questions, because + +that too is a signal. + +So the poker face is tricky to +do, but once you master it, + +that's one good way of giving +yourself a pause and not + +criticizing people for +their answers. + +So there are various ways, but +you just have to be careful. + +And if you do that regularly, +you'll find in a week or two, + +you've overcome the presumption +people have that + +it's dangerous to +ask questions. + +But you do have to work at it. + +Is it possible to incorporate +mastery learning at the + +college level? + +So actually, there is +a very interesting + +experiment on that. + +And it was done at MIT in +the 1970s, I believe. + +It was called-- + +so it was called the +Keller Plan. + +I don't know if they did it +for all courses, but the + +physics courses were +taught this way. + +I don't know if only that way, +or that was an option. + +So it was in the 1970s, +which was a time of-- + +as people who were here +then said, it was a + +very turbulent time. + +And the turbulence actually +enabled lots of educational + +experiments to happen, basically +the '60s and '70s. + +So if you look at, for example, +the Feynman lectures + +were in Caltech in the '60s, the +Berkeley physics course, + +1960s, things like the Keller +Plan, the free schools at the + +school level-- + +tons of experiments happened +in the '60s and '70s. + +So the Keller Plan +was one of them. + +It was mastery learning. + +Students worked on problems, and +when they were ready for + +the next piece, they +continued. + +And from what I can tell, +it worked pretty well. + +But then eventually it got +killed off by basically + +faculty who said, no, I'd rather +teach and do lectures. + +Because what's the point of the +faculty if the students + +can learn really well +from the books? + +So I think the Keller Plan +was a really good idea. + +In school, I learned for five +years of high school math in + +three or four weeks using the +Keller Plan, compared to the + +normal pace in school where you +spend a whole year doing + +trigonometry. + +So the Keller Plan is a really, +really excellent way, + +if you have reasonable books. + +So now, what are the full +reasons it died? + +I'm not really sure. + +I need to check into that. + +But people who were around then, +some of them said, yeah, + +just people who wanted to +perform in lecture were really + +sad about the Keller Plan +and wanted to go + +back to the old way. + +And so when the political +currents changed, so did the + +Keller Plan. + +How do I come up with these rich +and interesting examples + +like the wood blocks, +and how often do + +you incorporate demos? + +Well, we'll talk about that +in Walter Lewin's lecture. + +So if you saw Walter Lewin's +lecture, the one on the + +pendulum, he must have had +four or five different + +demonstrations. + +They were short, but he had +many demonstrations. + +And questions like this, if I +had 20 of these, I would use + +20 different ones. + +So usually I have four or five +of them that are a good long + +time demo that are suitable +for, say, half + +a lecture or longer. + +And I use them. + +So wherever I can find +them, I use them. + +But not every single demo is +worth spending 30 to 40 + +minutes on. + +So you have to think about +whether it teaches core ideas, + +how it fits with the goals +of your course. + +So for example, let me talk +through why I use this one. + +Well, one of the goals that I +want is I want students to be + +able to make physical +models themself. + +I don't want them to just be +able to solve equations that + +I've put in front of them. + +So normally what you do is you'd +teach them the bending + +beam equation, and then maybe +you'd show them this, and then + +you'd do this in two +or three minutes. + +But actually a much more +interesting question is not, + +what's the solution to the +bending beam equation when the + +beam's twice as thick. + +The question is, what physical +model is responsible for + +making sound? + +When you hear sound, where +is it coming from? + +When you tap this guy-- + +[TAPS A NOTE ON WOOD BLOCK]-- +why is it making sound, long + +before you're even discussing +the bending beam equation. + +So that question is, to my mind, +much more interesting. + +And so I'm very willing to spend +more time on that, and + +having students develop that +feel, and have them argue and + +realize that there's different +physical models. + +It could be a standing +wave in the block. + +It could be that the +block is bending. + +How do you decide, and how do +you decide which one you're + +going to hear more? + +And then for each one, how +do you figure out how the + +frequency's going to change? + +So that, because it fits so well +with the course goals, + +spend more time on it. + +Why is the stiffness a factor +of eight bigger? + +So that one, anyone who +wants to know, I will + +explain after lecture. + +Just come to office hours. + +So there's a simple picture +using wood atoms. + +Don't ask what wood atoms are. + +How can you incorporate aspects +of mastery learning + +into regular teaching? + +Ah, so that's what interactive +teaching is all about. + +So the reason mastery learning +works so well is that you're + +not building castles +of knowledge on + +sand, roughly speaking. + +So normally what happens-- so +the extreme case is Cambridge + +in England. + +So the teaching system there +is you have an eight-week + +term, and then you have a +six-week break, and then an + +eight-week term, six-week break, +eight-week term, and + +then 16-week break. + +So the eight-week term, about +what we would do in a semester + +is compressed into eight weeks, +just basically straight + +dictation and lecture. + +And the students have a hard +time really understanding + +everything at that pace, so +they just take dictation. + +And then you're supposed to +figure everything else out, + +integrate it in the +six-week break. + +So the problem with that is that +it's very inefficient. + +It's very inefficient because +you haven't understood A. And + +now B uses A, but A hasn't +really been understood. + +So you're not going to +understand B. So now you have + +A and B not really understood, +so you just write them down. + +Now C comes along using A and +B, but A and B aren't + +understood, so the problem +compounds. + +Whereas with mastery learning, +only when you understand A do + +you go onto B. And also when A +and B are solid, then you go + +onto C. So your knowledge +castles are robust and strong. + +And that's not true with +most teaching. + +So how do you remedy +that problem? + +Well one way is you ask +questions in lecture. + +So here, plan interactivity +and build + +it into your lecture. + +So by asking students questions +you figure out, oh, + +if only 20% or 30% or maybe even +40% of the students knew + +the correct answer, and even +after discussion, you think, + +oh, OK, well this is a +fundamental concept. + +Presumably that's why you asked +the question about it. + +But it wasn't mastered. + +So better fix it, before +you go on. + +So that builds mastery learning +into the regular + +lecturing process. + +And that's one reason +that interactive + +teaching is so effective. + +So one of the other questions +later in the sheets is, is + +there evidence that interactive +teaching is good + +and helps people learn? + +There is actually +good evidence. + +Maybe I should put some of +those papers online. + +One is by Richard Hake. + +He's now retired. + +He's physics professor from +Indiana University. + +So what he did is he did a +sample of physics courses + +across the country, intro +physics courses that included + +a total of 6,000 students. + +And he asked the instructors +to describe how they did + +everything. + +And then everything was +grouped into either + +interactive teaching or +regular teaching. + +And just the scores that +students got on one particular + +exam, which was a force concept + +inventory, before and after-- + +they were given the force +concept inventory before the + +class started and at the end-- + +they saw how much the +students improved. + +OK, so if you improved 100%-- + +in other words, suppose you +started at 20% correct and you + +got to 100%-- + +that was considered +a 1.0 gain. + +If you went from 20% percent +to 60%, that mean you got + +halfway to the maximum possible +score you could have + +gotten, so half of the maximum +improvement, that + +was a gain of 0.5. + +So he measured the gain +for everybody. + +So this is the gain on the +force concept inventory. + +And this is the number of +courses in each area. + +So it was roughly like that. + +So this was the regular. + +So the regular teaching, by the +way, included fantastic + +teachers, people who were rated +highest lecturer in the + +university and had won +lecturing awards. + +And the interactive teaching +was something like this. + +I'll put the paper online so you +can see the exact graph. + +But basically, the worst +interactive teaching was + +better than most of the +regular teaching. + +And the regular teaching +hardly got + +better than 0.2 or 0.3. + +So if you wanted any more gain +than that, you really needed + +to do interactive methods. + +And I think that is because +you've incorporated mastery + +learning into the curriculum. + +OK, what do you do when the +students are really quite and + +won't answer your questions? + +Or flip side is, what if only +the quote 5% usual suspects + +are the ones answering +the questions? + +What do you do? + +Well, so that is related to the +question of, are there bad + +ways of incorporating +interactivity? + +And there are. + +The worst is the following, +which is-- + +I'll sort of parody it. + +So we're doing relativity, +or nuclear physics. + +E equals MC-- + +[LAUGHTER] + +PROFESSOR: Squared, yeah. + +OK. + +So you'll find a lot of people +who normally wouldn't teach + +interactively are now, they're +told or they hear that it's + +good to teach interactively and +ask students questions. + +But if you don't have any +practice in how to do that, + +the easiest questions to ask +are just things like this. + +And the problem with +that is not that + +they're asking a question. + +It's good to ask a question. + +But the problem is that this +thing, this two, is just a + +memorized fact. + +So it's possible to answer it +just by memory, whereas if + +there was actually some debate +about what it should be, you + +could ask the students +the question. + +But now, if you just ask people +question like that, and + +you give people no time to +think, yes, you will get + +answers just from the quote top +5%, the usual suspects. + +So to avoid that, what you need +to do is give people a + +chance to think on their own. + +So that's one of the interactive +teaching + +techniques, the idea of give +people a minute or even 30 + +seconds to think on their own, +so that you'll get answers + +from a wider spectrum of +people, because they've + +checked it out with +their neighbor. + +And they feel safer in +volunteering and answer or + +asking a question about it. + +So that's how you avoid two +things, two problems at once. + +You avoid the quiet students, +because you've given-- those + +students are being quiet because +you've given people a + +chance to think. + +And you also avoid the problem +of just the usual people + +answering, because you've given + +everybody a chance to think. + +OK, if we don't really +understand until we teach, + +should we have students teach +each other in presentations, + +or is that not worth the time? + +My feeling is that huge big +presentations and having + +students present to each other +is not so much worth the time. + +I mean, it's worth the time of +the one person who's doing the + +presentation. + +But that's the main person +who learns in + +that teaching session. + +So there are several graduate +seminars, many I took as a + +graduate student, that are +run the following way. + +The professor just sits +back and each time-- + +they assign a list of topics, +and each student volunteers + +for one topic to present +to everybody else. + +Now, that is a fantastic way +to learn one topic in the + +entire course. + +And it does work for that. + +And part of my Ph.D. Came out +of one of the topics that I + +learned from one of those +courses, because I really + +wanted to figure it out. + +So it can work. + +And it does work in some ways. + +But it's not a very efficient +way, because all the other + +people are just basically +passive. + +Yeah, they read the stuff. + +But now they're being taught by +someone who's just barely + +mastering the field and is not +likely to teach interactively + +with a large margin of safety. + +So it's much better to have +students teach each other by + +having them argue with each +other on small time scale. + +So for example, if you remember +in the wood blocks, I + +said, OK, are you with your +neighbor about your answer? + +Well, now the students are +trying to teach each other. + +Some students think, oh yeah, +it's due to the bending. + +OK, well that turns +out to be correct. + +But can you convince +your neighbor? + +Well, in trying to convince +your neighbor, + +you are doing teaching. + +You're trying to figure out, +what's a way that you can do + +it without writing down +50 equations. + +That's exactly what you want +to do in teaching. + +So I think it's a much better +way, is to build the + +interactivity into the class +for everybody, rather than + +having it as a rotating seminar +where just one person + +at a time learns. + +In organizing big ideas +into a tree, there are + +often multiple ways-- + +for example, you can do current +understanding versus + +history, or experiment versus +theory-- and it's often good + +for students to know more than +one of these organizations. + +How do you do that in +a course design? + +Yeah, so unfortunately there's +only one time dimension. + +There's three space +dimensions, but + +only one time dimension. + +So the course has to evolve +in one dimension somehow. + +So you need at least +one organization. + +But you're right. + +You need other organizations +as well. + +So the way I square that +circle is as follows. + +So let's say time +goes that way. + +So this is unit one. + +Let's say it's one technique, +one mode of reasoning, + +dimensional analysis. + +Let's say this is another +mode of reasoning, + +conservation, and so on. + +So these are units. + +And now you have topics. + +Well, what I like to do is +I want to show other + +organizations. + +And why is that good? + +Well, what you're doing +is you're connecting. + +You're building threads +across. + +And you're right. + +You definitely want +to do that. + +So what I'll do is I'll find +problems that can be solved + +multiple ways. + +Suppose this is, for example, +a problem about a pendulum. + +Well, you can solve a pendulum +with dimensional analysis. + +You can also solve a pendulum +with conservation laws. + +So I'll do it again. + +So this way, this method is +sufficient to solve it mostly. + +This method is sufficient, +but now we're + +revisiting the old problem. + +So I try to find problems that +thread through, and maybe then + +reappear over here. + +So that gives you a cross +cutting organization. + +So you can do that not just with +problems, but with, for + +example, other principles. + +For example, the history-- + +suppose you want to incorporate +history versus + +current understanding. + +Well, every time you mention +history and the importance of + +history, you say, oh look, +there's yet another example + +where we learned from history. + +We learned it here. + +We've learned it in this unit. + +So now the students have yet +another structure to bind the + +course together. + +This is hard to do the first +time you teach the course. + +What you'll do is this first +time you teach your course, + +well, you'll probably do +it the regular way. + +The second time, you'll maybe +reorganize it this way. + +And the third time you do it, +you start building all the + +bridges across it. + +Because that's the only time +you actually see them too. + +What are my thoughts +on grade inflation? + +I wish every grade was an A. So +I think there isn't enough + +of it, because of the studies +I said before. + +So I'll talk about that in +the penultimate lecture. + +I think most of these, yeah, I +think I've now answered with + +other comments or questions +that are there, except for + +one, which I'll save +for next time. \ No newline at end of file diff --git a/62KrMWdX-RU.txt b/62KrMWdX-RU.txt new file mode 100644 index 0000000000000000000000000000000000000000..e99a0e02cf852042ef110c3f5c990c6ca02f388e --- /dev/null +++ b/62KrMWdX-RU.txt @@ -0,0 +1,249 @@ +Hi. + +In this video, we're going to +do standard probability + +calculations for normal +random variables. + +We're given that x is standard +normal with mean 0 and + +variance 1. + +And y is normal with mean +one and variance 4. + +And we're asked for a couple +of probabilities. + +For the normal CDF, we don't +have a closed form expression. + +And so people generally tabulate +values and for the + +standard normal case. + +So if we want little x equal to +3.49, we just look for 3.4 + +along the rows and 0.09 along +the columns, and then pick the + +value appropriately. + +So for part A, we're asked +what's the probability that x + +is less than equal to 1.5? + +That's exactly phi of 1.5 +and we can look that up. + +1.5 directly and +that's 0.9332. + +Then were asked, what's the +probability that x is less + +than equal to negative 1? + +Notice that negative values +are not on this table. + +And the reason that is is +because the standard normal is + +symmetric around zero. + +And we don't really need that. + +We just recognize that the area +in this region is exactly + +the area in this region. + +And so that's equal to the +probability that x is greater + +than equal to 1. + +This is equal to 1 minus +the probability that x + +is less than 1. + +And we can put the equal sign +in here because x is + +continuous, it doesn't matter. + +And so we're going to get, +this is equal to 1 + +minus phi of one. + +And we can look up phi +of 1, which is + +1.00, and that's 0.8413. + +OK. + +For part B, we're asked for +this distribution of y + +minus 1 over 2. + +So any linear function +of a normal random + +variable is also normal. + +And you can see that by using +the derived distribution for + +linear functions of +random variables. + +So in this case, we only need to +figure out what's the mean + +and the variance of this +normal random variable. + +So the mean in this case, I'm +going to write that as y over + +2 minus 1/2. + + + +The expectation operator +is linear and so + +that's going to be-- + + + +and the expectation in +this case is 1, so + +that's going to be 0. + +Now the variance. + + + +For the shift, it doesn't +affect the spread. + +And so the variance is exactly +going to be the same without + +the minus 1/2. + +And for the constant, you +can just pull that + +out and square it. + + + +And the variance of +y we know is 4. + +And so that's 1/4 times +4, that's 1. + +OK. + +So now we know that y +minus 1 over 2 is + +actually standard normal. + + + +Actually for any normal random +variable, you can follow the + +same procedure. + +You just subtract its mean, +which is 1 in this case. + +And divide by its standard +deviation and you will get a + +standard normal distribution. + +All right, so for part C we want +the probability that y is + +between negative 1 and 1. + +So let's try to massage it so +that we can use the standard + +normal table. + +And we already know that this +is standard normal, so let's + +subtract both sides +by negative 1. + + + +And that's equal to-- + +I'm going to call this standard +normal z, so that's + +easier to write. + +And that's equal to negative 1 +less than equal to z, less + +than equal to zero. + +So we're looking for this +region, 0, 1, negative 1. + + + +So that's just the probability +that it's less than zero minus + +probability that it's less +than negative 1. + +Well for a standard normal, half +the mass is below zero + +and a half the mass is above. + +And so that's just going +to be 0.5 directly. + +And for this, we've already +computed this for a standard + +normal, which was +x in our case. + +And that was 1 minus 0.8413. + +Done. + +So we basically calculated a few +standard probabilities for + +normal distributions. + +And we did that by looking +them up from the standard + +normal table. \ No newline at end of file diff --git a/6rOvXGoXoJc.txt b/6rOvXGoXoJc.txt new file mode 100644 index 0000000000000000000000000000000000000000..43a7e34f74a872ddc5565e57426ad59ee91f6cb7 --- /dev/null +++ b/6rOvXGoXoJc.txt @@ -0,0 +1,6619 @@ +align:start position:0% + +so I guess I will start by first of all + + align:start position:0% +so I guess I will start by first of all + + + align:start position:0% +so I guess I will start by first of all +congratulating you all since the last + + align:start position:0% +congratulating you all since the last + + + align:start position:0% +congratulating you all since the last +time I've seen you you've all + + align:start position:0% +time I've seen you you've all + + + align:start position:0% +time I've seen you you've all +regenerated your intestine so it's like + + align:start position:0% +regenerated your intestine so it's like + + + align:start position:0% +regenerated your intestine so it's like +you're a brand-new person okay so so + + align:start position:0% +you're a brand-new person okay so so + + + align:start position:0% +you're a brand-new person okay so so +there's that I want to start the lecture + + align:start position:0% +there's that I want to start the lecture + + + align:start position:0% +there's that I want to start the lecture +by talking about something I've been + + align:start position:0% +by talking about something I've been + + + align:start position:0% +by talking about something I've been +putting off telling you about which is + + align:start position:0% +putting off telling you about which is + + + align:start position:0% +putting off telling you about which is +the Nobel Prize in Physiology or + + align:start position:0% +the Nobel Prize in Physiology or + + + align:start position:0% +the Nobel Prize in Physiology or +medicine that was awarded this year and + + align:start position:0% +medicine that was awarded this year and + + + align:start position:0% +medicine that was awarded this year and +it was awarded to James Allison and + + align:start position:0% +it was awarded to James Allison and + + + align:start position:0% +it was awarded to James Allison and +tasuku hangzhou for their discovery of a + + align:start position:0% +tasuku hangzhou for their discovery of a + + + align:start position:0% +tasuku hangzhou for their discovery of a +way to harness the immune system to + + align:start position:0% +way to harness the immune system to + + + align:start position:0% +way to harness the immune system to +fight cancer okay and we're gonna talk + + align:start position:0% +fight cancer okay and we're gonna talk + + + align:start position:0% +fight cancer okay and we're gonna talk +about the immune system later in the + + align:start position:0% +about the immune system later in the + + + align:start position:0% +about the immune system later in the +course + + align:start position:0% +course + + + align:start position:0% +course +and it turns out I I will lecture on it + + align:start position:0% +and it turns out I I will lecture on it + + + align:start position:0% +and it turns out I I will lecture on it +and I've actually had immunology and in + + align:start position:0% +and I've actually had immunology and in + + + align:start position:0% +and I've actually had immunology and in +fact I had immunology with James Allison + + align:start position:0% +fact I had immunology with James Allison + + + align:start position:0% +fact I had immunology with James Allison +so I will do my best to channel James + + align:start position:0% +so I will do my best to channel James + + + align:start position:0% +so I will do my best to channel James +Allison when I talk about the immune + + align:start position:0% +Allison when I talk about the immune + + + align:start position:0% +Allison when I talk about the immune +system but what what they won the prize + + align:start position:0% +system but what what they won the prize + + + align:start position:0% +system but what what they won the prize +for is they figured out a way to + + align:start position:0% +for is they figured out a way to + + + align:start position:0% +for is they figured out a way to +essentially release the break on the + + align:start position:0% +essentially release the break on the + + + align:start position:0% +essentially release the break on the +immune system in order to allow the + + align:start position:0% +immune system in order to allow the + + + align:start position:0% +immune system in order to allow the +immune system system to better fight + + align:start position:0% +immune system system to better fight + + + align:start position:0% +immune system system to better fight +cancer okay and this is a technique + + align:start position:0% +cancer okay and this is a technique + + + align:start position:0% +cancer okay and this is a technique +that's been used in the clinic and there + + align:start position:0% +that's been used in the clinic and there + + + align:start position:0% +that's been used in the clinic and there +are currently a number of clinical + + align:start position:0% +are currently a number of clinical + + + align:start position:0% +are currently a number of clinical +trials that are also looking to see + + align:start position:0% +trials that are also looking to see + + + align:start position:0% +trials that are also looking to see +whether this can be used in a variety of + + align:start position:0% +whether this can be used in a variety of + + + align:start position:0% +whether this can be used in a variety of +different cancer types okay so I just + + align:start position:0% +different cancer types okay so I just + + + align:start position:0% +different cancer types okay so I just +wanted to point that out now because + + align:start position:0% +wanted to point that out now because + + + align:start position:0% +wanted to point that out now because +we're talking about cancer and I'll go + + align:start position:0% +we're talking about cancer and I'll go + + + align:start position:0% +we're talking about cancer and I'll go +more into the mechanism is how this + + align:start position:0% +more into the mechanism is how this + + + align:start position:0% +more into the mechanism is how this +works when we start talking about the + + align:start position:0% +works when we start talking about the + + + align:start position:0% +works when we start talking about the +immune system so as I mentioned in the + + align:start position:0% +immune system so as I mentioned in the + + + align:start position:0% +immune system so as I mentioned in the +last lecture cancer is basically a + + align:start position:0% +last lecture cancer is basically a + + + align:start position:0% +last lecture cancer is basically a +progressive loss of tissue organization + + align:start position:0% +progressive loss of tissue organization + + + align:start position:0% +progressive loss of tissue organization +and luckily for us our body has a number + + align:start position:0% +and luckily for us our body has a number + + + align:start position:0% +and luckily for us our body has a number +of different barriers to cells becoming + + align:start position:0% +of different barriers to cells becoming + + + align:start position:0% +of different barriers to cells becoming +cancerous and forming a tumor and so I + + align:start position:0% +cancerous and forming a tumor and so I + + + align:start position:0% +cancerous and forming a tumor and so I +wanted to start out just by having you + + align:start position:0% +wanted to start out just by having you + + + align:start position:0% +wanted to start out just by having you +guys tell me what you feel the barriers + + align:start position:0% +guys tell me what you feel the barriers + + + align:start position:0% +guys tell me what you feel the barriers +would be + + align:start position:0% +would be + + + align:start position:0% +would be +to this process so who has an idea of a + + align:start position:0% +to this process so who has an idea of a + + + align:start position:0% +to this process so who has an idea of a +barrier what are the barriers in place + + align:start position:0% +barrier what are the barriers in place + + + align:start position:0% +barrier what are the barriers in place +by your body to prevent cancer cells + + align:start position:0% +by your body to prevent cancer cells + + + align:start position:0% +by your body to prevent cancer cells +from arising and forming a tumor and for + + align:start position:0% +from arising and forming a tumor and for + + + align:start position:0% +from arising and forming a tumor and for +this process to form a malignant tumor + + align:start position:0% + + + + align:start position:0% + +what's that Oh Rachel sorry apoptosis is + + align:start position:0% +what's that Oh Rachel sorry apoptosis is + + + align:start position:0% +what's that Oh Rachel sorry apoptosis is +a good one + + align:start position:0% +a good one + + + align:start position:0% +a good one +right so there's a careful process right + + align:start position:0% +right so there's a careful process right + + + align:start position:0% +right so there's a careful process right +in the in your body to limit how long + + align:start position:0% +in the in your body to limit how long + + + align:start position:0% +in the in your body to limit how long +certain cells are resident in the body + + align:start position:0% +certain cells are resident in the body + + + align:start position:0% +certain cells are resident in the body +and all of this depends on communication + + align:start position:0% +and all of this depends on communication + + + align:start position:0% +and all of this depends on communication +between different cell types in your + + align:start position:0% +between different cell types in your + + + align:start position:0% +between different cell types in your +body so so barriers to tumorigenesis and + + align:start position:0% +body so so barriers to tumorigenesis and + + + align:start position:0% +body so so barriers to tumorigenesis and +one type of signal is a survival signal + + align:start position:0% +one type of signal is a survival signal + + + align:start position:0% +one type of signal is a survival signal +and if a cell is not getting a survival + + align:start position:0% +and if a cell is not getting a survival + + + align:start position:0% +and if a cell is not getting a survival +signal then the cell will undergo + + align:start position:0% +signal then the cell will undergo + + + align:start position:0% +signal then the cell will undergo +apoptosis which is what Rachel was + + align:start position:0% +apoptosis which is what Rachel was + + + align:start position:0% +apoptosis which is what Rachel was +referring to right so one barrier is + + align:start position:0% +referring to right so one barrier is + + + align:start position:0% +referring to right so one barrier is +that there is a highly regulated system + + align:start position:0% +that there is a highly regulated system + + + align:start position:0% +that there is a highly regulated system +of determining whether or not cells + + align:start position:0% +of determining whether or not cells + + + align:start position:0% +of determining whether or not cells +divide and also whether or not cells + + align:start position:0% +divide and also whether or not cells + + + align:start position:0% +divide and also whether or not cells +live okay so there are growth survival + + align:start position:0% +live okay so there are growth survival + + + align:start position:0% +live okay so there are growth survival +signals which means that the decision + + align:start position:0% +signals which means that the decision + + + align:start position:0% +signals which means that the decision +for a cell to sort of go off its rocker + + align:start position:0% +for a cell to sort of go off its rocker + + + align:start position:0% +for a cell to sort of go off its rocker +and just start dividing uncontrollably + + align:start position:0% +and just start dividing uncontrollably + + + align:start position:0% +and just start dividing uncontrollably +is not likely for a normal cell + + align:start position:0% +is not likely for a normal cell + + + align:start position:0% +is not likely for a normal cell +something has to happen to that cell in + + align:start position:0% +something has to happen to that cell in + + + align:start position:0% +something has to happen to that cell in +order to perturb it okay so what are + + align:start position:0% +order to perturb it okay so what are + + + align:start position:0% +order to perturb it okay so what are +some other barriers to sort of forming a + + align:start position:0% +some other barriers to sort of forming a + + + align:start position:0% +some other barriers to sort of forming a +tumor and for that tumor to become + + align:start position:0% +tumor and for that tumor to become + + + align:start position:0% +tumor and for that tumor to become +invasive yes Jeremy yeah so the this + + align:start position:0% +invasive yes Jeremy yeah so the this + + + align:start position:0% +invasive yes Jeremy yeah so the this +cancer cell can't activate the immune + + align:start position:0% +cancer cell can't activate the immune + + + align:start position:0% +cancer cell can't activate the immune +system so you could have some type of + + align:start position:0% +system so you could have some type of + + + align:start position:0% +system so you could have some type of +immuno suppression of the cancer + + align:start position:0% +immuno suppression of the cancer + + + align:start position:0% +immuno suppression of the cancer +and I won't talk about that today but + + align:start position:0% +and I won't talk about that today but + + + align:start position:0% +and I won't talk about that today but +maybe we'll come back and talk about it + + align:start position:0% +maybe we'll come back and talk about it + + + align:start position:0% +maybe we'll come back and talk about it +when we talk about the immune system + + align:start position:0% +when we talk about the immune system + + + align:start position:0% +when we talk about the immune system +okay looking looking at this diagram + + align:start position:0% +okay looking looking at this diagram + + + align:start position:0% +okay looking looking at this diagram +when the cell proceeded when the + + align:start position:0% +when the cell proceeded when the + + + align:start position:0% +when the cell proceeded when the +tumorous proceeds to invasive cancer + + align:start position:0% +tumorous proceeds to invasive cancer + + + align:start position:0% +tumorous proceeds to invasive cancer +what do you think are some barriers to + + align:start position:0% +what do you think are some barriers to + + + align:start position:0% +what do you think are some barriers to +that process happening what are cells + + align:start position:0% +that process happening what are cells + + + align:start position:0% +that process happening what are cells +new normally doing in an organ right the + + align:start position:0% +new normally doing in an organ right the + + + align:start position:0% +new normally doing in an organ right the +cells that line your intestine are they + + align:start position:0% +cells that line your intestine are they + + + align:start position:0% +cells that line your intestine are they +like invading into the surrounding + + align:start position:0% +like invading into the surrounding + + + align:start position:0% +like invading into the surrounding +tissue no Jeremy's shaking his head no + + align:start position:0% +tissue no Jeremy's shaking his head no + + + align:start position:0% +tissue no Jeremy's shaking his head no +right so normally cells don't do that + + align:start position:0% +right so normally cells don't do that + + + align:start position:0% +right so normally cells don't do that +right or certain types of cells do but + + align:start position:0% +right or certain types of cells do but + + + align:start position:0% +right or certain types of cells do but +normally if you have cells that are the + + align:start position:0% +normally if you have cells that are the + + + align:start position:0% +normally if you have cells that are the +lining of an epithelium they're not like + + align:start position:0% +lining of an epithelium they're not like + + + align:start position:0% +lining of an epithelium they're not like +going and going off to a blood vessel + + align:start position:0% +going and going off to a blood vessel + + + align:start position:0% +going and going off to a blood vessel +okay so I'm just going to sort of review + + align:start position:0% +okay so I'm just going to sort of review + + + align:start position:0% +okay so I'm just going to sort of review +sort of the structure of the tissue and + + align:start position:0% +sort of the structure of the tissue and + + + align:start position:0% +sort of the structure of the tissue and +then we'll talk about some of the + + align:start position:0% +then we'll talk about some of the + + + align:start position:0% +then we'll talk about some of the +barriers that prevent this from + + align:start position:0% +barriers that prevent this from + + + align:start position:0% +barriers that prevent this from +happening so I'm drawing a tubular organ + + align:start position:0% +happening so I'm drawing a tubular organ + + + align:start position:0% +happening so I'm drawing a tubular organ +here right this could be the tube of the + + align:start position:0% +here right this could be the tube of the + + + align:start position:0% +here right this could be the tube of the +intestine there would be a lumen inside + + align:start position:0% +intestine there would be a lumen inside + + + align:start position:0% +intestine there would be a lumen inside +here it could be some ductal structure + + align:start position:0% +here it could be some ductal structure + + + align:start position:0% +here it could be some ductal structure +in an organ like a mammary gland it + + align:start position:0% +in an organ like a mammary gland it + + + align:start position:0% +in an organ like a mammary gland it +could be that this is the airway of a + + align:start position:0% +could be that this is the airway of a + + + align:start position:0% +could be that this is the airway of a +lung and there's an epithelial lining + + align:start position:0% +lung and there's an epithelial lining + + + align:start position:0% +lung and there's an epithelial lining +around that airway so these cells here + + align:start position:0% +around that airway so these cells here + + + align:start position:0% +around that airway so these cells here +are forming an epithelial lining and one + + align:start position:0% +are forming an epithelial lining and one + + + align:start position:0% +are forming an epithelial lining and one +important aspect of epithelial biology + + align:start position:0% +important aspect of epithelial biology + + + align:start position:0% +important aspect of epithelial biology +is in mature epithelia they have a floor + + align:start position:0% +is in mature epithelia they have a floor + + + align:start position:0% +is in mature epithelia they have a floor +that the cells stand on okay so this + + align:start position:0% +that the cells stand on okay so this + + + align:start position:0% +that the cells stand on okay so this +structure that I just drew around these + + align:start position:0% +structure that I just drew around these + + + align:start position:0% +structure that I just drew around these +cells in green is known as the basement + + align:start position:0% +cells in green is known as the basement + + + align:start position:0% +cells in green is known as the basement +membrane all right it's the basement + + align:start position:0% +membrane all right it's the basement + + + align:start position:0% +membrane all right it's the basement +because it's kind of the floor that this + + align:start position:0% +because it's kind of the floor that this + + + align:start position:0% +because it's kind of the floor that this +other thing is built on and this + + align:start position:0% +other thing is built on and this + + + align:start position:0% +other thing is built on and this +basement membrane is made out of what is + + align:start position:0% +basement membrane is made out of what is + + + align:start position:0% +basement membrane is made out of what is +known as the extracellular matrix which + + align:start position:0% +known as the extracellular matrix which + + + align:start position:0% +known as the extracellular matrix which +I'll just call matrix right now the + + align:start position:0% +I'll just call matrix right now the + + + align:start position:0% +I'll just call matrix right now the +extracellular matrix are base + + align:start position:0% +extracellular matrix are base + + + align:start position:0% +extracellular matrix are base +Stickley extracellular proteins that + + align:start position:0% +Stickley extracellular proteins that + + + align:start position:0% +Stickley extracellular proteins that +form a meshwork + + align:start position:0% +form a meshwork + + + align:start position:0% +form a meshwork +that forms a rate rigid structure on + + align:start position:0% +that forms a rate rigid structure on + + + align:start position:0% +that forms a rate rigid structure on +which epithelial cells can sit on okay + + align:start position:0% +which epithelial cells can sit on okay + + + align:start position:0% +which epithelial cells can sit on okay +now if we think about what surrounds + + align:start position:0% +now if we think about what surrounds + + + align:start position:0% +now if we think about what surrounds +this organ there's there's also matrix + + align:start position:0% +this organ there's there's also matrix + + + align:start position:0% +this organ there's there's also matrix +proteins and sort of intervening areas + + align:start position:0% + + + + align:start position:0% + +and this is known as connective tissue + + align:start position:0% + + + + align:start position:0% + +okay and so if we think about the cells + + align:start position:0% +okay and so if we think about the cells + + + align:start position:0% +okay and so if we think about the cells +that are the epithelial cells here they + + align:start position:0% +that are the epithelial cells here they + + + align:start position:0% +that are the epithelial cells here they +are in one state and this state is known + + align:start position:0% +are in one state and this state is known + + + align:start position:0% +are in one state and this state is known +as epithelial as I just said so these + + align:start position:0% +as epithelial as I just said so these + + + align:start position:0% +as epithelial as I just said so these +are both alleles epithelial cells have a + + align:start position:0% +are both alleles epithelial cells have a + + + align:start position:0% +are both alleles epithelial cells have a +few properties that are really + + align:start position:0% +few properties that are really + + + align:start position:0% +few properties that are really +distinguishing the first is that they + + align:start position:0% +distinguishing the first is that they + + + align:start position:0% +distinguishing the first is that they +have high intercellular adhesion and the + + align:start position:0% +have high intercellular adhesion and the + + + align:start position:0% +have high intercellular adhesion and the +next is that if you consider their + + align:start position:0% +next is that if you consider their + + + align:start position:0% +next is that if you consider their +relative mobility you know they can + + align:start position:0% +relative mobility you know they can + + + align:start position:0% +relative mobility you know they can +obviously move within the epithelium + + align:start position:0% +obviously move within the epithelium + + + align:start position:0% +obviously move within the epithelium +because we talked about the intestine + + align:start position:0% +because we talked about the intestine + + + align:start position:0% +because we talked about the intestine +and how cells are moving from the base + + align:start position:0% +and how cells are moving from the base + + + align:start position:0% +and how cells are moving from the base +of the crypts up to the villas but in + + align:start position:0% +of the crypts up to the villas but in + + + align:start position:0% +of the crypts up to the villas but in +general these cells aren't moving in and + + align:start position:0% +general these cells aren't moving in and + + + align:start position:0% +general these cells aren't moving in and +out of the organ okay so I would say + + align:start position:0% +out of the organ okay so I would say + + + align:start position:0% +out of the organ okay so I would say +that they have a low migratory potential + + align:start position:0% + + + + align:start position:0% + +okay and so these are the epithelial + + align:start position:0% +okay and so these are the epithelial + + + align:start position:0% +okay and so these are the epithelial +cells that are here now there are also + + align:start position:0% +cells that are here now there are also + + + align:start position:0% +cells that are here now there are also +cells that are in this interstitial + + align:start position:0% +cells that are in this interstitial + + + align:start position:0% +cells that are in this interstitial +space and I'll draw they often have this + + align:start position:0% +space and I'll draw they often have this + + + align:start position:0% +space and I'll draw they often have this +highly elongated morphology and these + + align:start position:0% +highly elongated morphology and these + + + align:start position:0% +highly elongated morphology and these +cells are in a fundamentally different + + align:start position:0% +cells are in a fundamentally different + + + align:start position:0% +cells are in a fundamentally different +state okay and this state is known as + + align:start position:0% +state okay and this state is known as + + + align:start position:0% +state okay and this state is known as +mesenchymal + + align:start position:0% + + + + align:start position:0% + +or stromal so this area sort of outside + + align:start position:0% +or stromal so this area sort of outside + + + align:start position:0% +or stromal so this area sort of outside +the organ is also known as the stroma so + + align:start position:0% +the organ is also known as the stroma so + + + align:start position:0% +the organ is also known as the stroma so +there are known as stromal cells in this + + align:start position:0% +there are known as stromal cells in this + + + align:start position:0% +there are known as stromal cells in this +in this location and these cells have + + align:start position:0% +in this location and these cells have + + + align:start position:0% +in this location and these cells have +very different properties than + + align:start position:0% +very different properties than + + + align:start position:0% +very different properties than +epithelial cells and that they have low + + align:start position:0% +epithelial cells and that they have low + + + align:start position:0% +epithelial cells and that they have low +adhesion I should say low cell to cell + + align:start position:0% +adhesion I should say low cell to cell + + + align:start position:0% +adhesion I should say low cell to cell +adhesion and in contrast to these + + align:start position:0% +adhesion and in contrast to these + + + align:start position:0% +adhesion and in contrast to these +epithelial cells these stromal cells as + + align:start position:0% +epithelial cells these stromal cells as + + + align:start position:0% +epithelial cells these stromal cells as +you see in this example up here for + + align:start position:0% +you see in this example up here for + + + align:start position:0% +you see in this example up here for +that's a human neutrophil these stromal + + align:start position:0% +that's a human neutrophil these stromal + + + align:start position:0% +that's a human neutrophil these stromal +cells are highly migratory so that + + align:start position:0% +cells are highly migratory so that + + + align:start position:0% +cells are highly migratory so that +neutrophil is chasing a bacterium and + + align:start position:0% +neutrophil is chasing a bacterium and + + + align:start position:0% +neutrophil is chasing a bacterium and +they'll eventually get it but the movie + + align:start position:0% +they'll eventually get it but the movie + + + align:start position:0% +they'll eventually get it but the movie +will loop and so you'll see it + + align:start position:0% +will loop and so you'll see it + + + align:start position:0% +will loop and so you'll see it +constantly chasing that bacterium okay + + align:start position:0% +constantly chasing that bacterium okay + + + align:start position:0% +constantly chasing that bacterium okay +so some examples of stromal cells would + + align:start position:0% +so some examples of stromal cells would + + + align:start position:0% +so some examples of stromal cells would +be immune cells like this human + + align:start position:0% +be immune cells like this human + + + align:start position:0% +be immune cells like this human +neutrophil and you probably know that + + align:start position:0% +neutrophil and you probably know that + + + align:start position:0% +neutrophil and you probably know that +immune cells have to traverse different + + align:start position:0% +immune cells have to traverse different + + + align:start position:0% +immune cells have to traverse different +organ systems they have to be rapidly + + align:start position:0% +organ systems they have to be rapidly + + + align:start position:0% +organ systems they have to be rapidly +recruited to sites of infection or sites + + align:start position:0% +recruited to sites of infection or sites + + + align:start position:0% +recruited to sites of infection or sites +of injury and so this type of cell has + + align:start position:0% +of injury and so this type of cell has + + + align:start position:0% +of injury and so this type of cell has +is fundamentally different from the + + align:start position:0% +is fundamentally different from the + + + align:start position:0% +is fundamentally different from the +types of cells that line your organs + + align:start position:0% +types of cells that line your organs + + + align:start position:0% +types of cells that line your organs +where you basically need those cells to + + align:start position:0% +where you basically need those cells to + + + align:start position:0% +where you basically need those cells to +stay put okay when considering cancer + + align:start position:0% +stay put okay when considering cancer + + + align:start position:0% +stay put okay when considering cancer +right you have these different types of + + align:start position:0% +right you have these different types of + + + align:start position:0% +right you have these different types of +cells in your body 90% of cancer comes + + align:start position:0% +cells in your body 90% of cancer comes + + + align:start position:0% +cells in your body 90% of cancer comes +from a cell of epithelial origin okay so + + align:start position:0% +from a cell of epithelial origin okay so + + + align:start position:0% +from a cell of epithelial origin okay so +90% of cancers are epithelial and origin + + align:start position:0% + + + + align:start position:0% + +okay some other examples of stromal + + align:start position:0% +okay some other examples of stromal + + + align:start position:0% +okay some other examples of stromal +cells are cells like fibroblasts and + + align:start position:0% +cells are cells like fibroblasts and + + + align:start position:0% +cells are cells like fibroblasts and +fibroblasts are cells that secrete and + + align:start position:0% +fibroblasts are cells that secrete and + + + align:start position:0% +fibroblasts are cells that secrete and +remodel the matrix that's in connective + + align:start position:0% +remodel the matrix that's in connective + + + align:start position:0% +remodel the matrix that's in connective +tissue and they're also important for + + align:start position:0% +tissue and they're also important for + + + align:start position:0% +tissue and they're also important for +wound healing and secreting matrix + + align:start position:0% +wound healing and secreting matrix + + + align:start position:0% +wound healing and secreting matrix +during the wound healing process okay so + + align:start position:0% +during the wound healing process okay so + + + align:start position:0% +during the wound healing process okay so +that's just to give you a few examples + + align:start position:0% + + + + align:start position:0% + +okay so now let's come back to this + + align:start position:0% +okay so now let's come back to this + + + align:start position:0% +okay so now let's come back to this +example and talk about how is it what + + align:start position:0% +example and talk about how is it what + + + align:start position:0% +example and talk about how is it what +what happens to get a cell to go all the + + align:start position:0% +what happens to get a cell to go all the + + + align:start position:0% +what happens to get a cell to go all the +way from being a normal epithelial cell + + align:start position:0% +way from being a normal epithelial cell + + + align:start position:0% +way from being a normal epithelial cell +to having this type of behavior where + + align:start position:0% +to having this type of behavior where + + + align:start position:0% +to having this type of behavior where +initially you have growth and a loss of + + align:start position:0% +initially you have growth and a loss of + + + align:start position:0% +initially you have growth and a loss of +the control over growth and survival + + align:start position:0% +the control over growth and survival + + + align:start position:0% +the control over growth and survival +signaling and eventually the cancer can + + align:start position:0% +signaling and eventually the cancer can + + + align:start position:0% +signaling and eventually the cancer can +become what's known as malignant and + + align:start position:0% +become what's known as malignant and + + + align:start position:0% +become what's known as malignant and +what's known so it's a progression and + + align:start position:0% +what's known so it's a progression and + + + align:start position:0% +what's known so it's a progression and +initially you might just get increased + + align:start position:0% +initially you might just get increased + + + align:start position:0% +initially you might just get increased +in cell division and abnormal cell shape + + align:start position:0% +in cell division and abnormal cell shape + + + align:start position:0% +in cell division and abnormal cell shape +which is known as dysplasia and at that + + align:start position:0% +which is known as dysplasia and at that + + + align:start position:0% +which is known as dysplasia and at that +point the it's known as something like + + align:start position:0% +point the it's known as something like + + + align:start position:0% +point the it's known as something like +an adenoma or something that's benign + + align:start position:0% +an adenoma or something that's benign + + + align:start position:0% +an adenoma or something that's benign +but it's this last point here up here + + align:start position:0% +but it's this last point here up here + + + align:start position:0% +but it's this last point here up here +where the cells breach this basement + + align:start position:0% +where the cells breach this basement + + + align:start position:0% +where the cells breach this basement +membrane that's when that happens then + + align:start position:0% +membrane that's when that happens then + + + align:start position:0% +membrane that's when that happens then +the cancer is known as carcinoma and + + align:start position:0% +the cancer is known as carcinoma and + + + align:start position:0% +the cancer is known as carcinoma and +it's on the lignin + + align:start position:0% + + + + align:start position:0% + +so malignant look malignant cancer is + + align:start position:0% +so malignant look malignant cancer is + + + align:start position:0% +so malignant look malignant cancer is +cancer that has breached the basement + + align:start position:0% +cancer that has breached the basement + + + align:start position:0% +cancer that has breached the basement +membrane + + align:start position:0% + + + + align:start position:0% + +all right so I want to sort of take you + + align:start position:0% +all right so I want to sort of take you + + + align:start position:0% +all right so I want to sort of take you +through the progression of tumorigenesis + + align:start position:0% +through the progression of tumorigenesis + + + align:start position:0% +through the progression of tumorigenesis +and first I'm gonna start with the + + align:start position:0% +and first I'm gonna start with the + + + align:start position:0% +and first I'm gonna start with the +breakdown of this growth survival + + align:start position:0% +breakdown of this growth survival + + + align:start position:0% +breakdown of this growth survival +signaling and I just wanted to remind + + align:start position:0% +signaling and I just wanted to remind + + + align:start position:0% +signaling and I just wanted to remind +you about what we talked about with the + + align:start position:0% +you about what we talked about with the + + + align:start position:0% +you about what we talked about with the +intestine as our model organ and in the + + align:start position:0% +intestine as our model organ and in the + + + align:start position:0% +intestine as our model organ and in the +intestine remember that this is all + + align:start position:0% +intestine remember that this is all + + + align:start position:0% +intestine remember that this is all +regulated by signals between cells and + + align:start position:0% +regulated by signals between cells and + + + align:start position:0% +regulated by signals between cells and +like stem cells and niche cells so the + + align:start position:0% +like stem cells and niche cells so the + + + align:start position:0% +like stem cells and niche cells so the +niche cells are sent sending the stem + + align:start position:0% +niche cells are sent sending the stem + + + align:start position:0% +niche cells are sent sending the stem +cells signals like wints that control + + align:start position:0% +cells signals like wints that control + + + align:start position:0% +cells signals like wints that control +their self-renewal and then it's the + + align:start position:0% +their self-renewal and then it's the + + + align:start position:0% +their self-renewal and then it's the +loss of this signaling that allows these + + align:start position:0% +loss of this signaling that allows these + + + align:start position:0% +loss of this signaling that allows these +cells to eventually undergo apoptosis + + align:start position:0% +cells to eventually undergo apoptosis + + + align:start position:0% +cells to eventually undergo apoptosis +and get shed into the lumen of the + + align:start position:0% +and get shed into the lumen of the + + + align:start position:0% +and get shed into the lumen of the +intestine okay so one of the first steps + + align:start position:0% +intestine okay so one of the first steps + + + align:start position:0% +intestine okay so one of the first steps +in cancer is this breakdown and growth + + align:start position:0% +in cancer is this breakdown and growth + + + align:start position:0% +in cancer is this breakdown and growth +survival signaling so this this first + + align:start position:0% +survival signaling so this this first + + + align:start position:0% +survival signaling so this this first +breakdown is going to enable the cells + + align:start position:0% +breakdown is going to enable the cells + + + align:start position:0% +breakdown is going to enable the cells +to sort of overcome this first barrier + + align:start position:0% + + + + align:start position:0% + +okay and so as I just pointed out + + align:start position:0% +okay and so as I just pointed out + + + align:start position:0% +okay and so as I just pointed out +remember it helps to think of what has + + align:start position:0% +remember it helps to think of what has + + + align:start position:0% +remember it helps to think of what has +to happen in a normal tissue or organ + + align:start position:0% +to happen in a normal tissue or organ + + + align:start position:0% +to happen in a normal tissue or organ +normally the decision whether or not a + + align:start position:0% +normally the decision whether or not a + + + align:start position:0% +normally the decision whether or not a +cell divides or death dies so cell + + align:start position:0% +cell divides or death dies so cell + + + align:start position:0% +cell divides or death dies so cell +division and also death is highly + + align:start position:0% +division and also death is highly + + + align:start position:0% +division and also death is highly +regulated okay and it's regulated by + + align:start position:0% +regulated okay and it's regulated by + + + align:start position:0% +regulated okay and it's regulated by +communication with other cells + + align:start position:0% + + + + align:start position:0% + +so in cancer this regulation goes awry + + align:start position:0% + + + + align:start position:0% + +right and how would this regulation go + + align:start position:0% +right and how would this regulation go + + + align:start position:0% +right and how would this regulation go +awry yeah Jeremy + + align:start position:0% + + + + align:start position:0% + +so Jeremy suggested that there could be + + align:start position:0% +so Jeremy suggested that there could be + + + align:start position:0% +so Jeremy suggested that there could be +mutations like oncogenic mutations or + + align:start position:0% +mutations like oncogenic mutations or + + + align:start position:0% +mutations like oncogenic mutations or +tumor suppressor loss that lead to + + align:start position:0% +tumor suppressor loss that lead to + + + align:start position:0% +tumor suppressor loss that lead to +abnormal cell division and death and + + align:start position:0% +abnormal cell division and death and + + + align:start position:0% +abnormal cell division and death and +that is exactly right so you could have + + align:start position:0% +that is exactly right so you could have + + + align:start position:0% +that is exactly right so you could have +uncle genic mutations and these + + align:start position:0% +uncle genic mutations and these + + + align:start position:0% +uncle genic mutations and these +oncogenic mutations they often hyper + + align:start position:0% +oncogenic mutations they often hyper + + + align:start position:0% +oncogenic mutations they often hyper +activate or constitutively activate + + align:start position:0% +activate or constitutively activate + + + align:start position:0% +activate or constitutively activate +these growth signaling pathways that are + + align:start position:0% +these growth signaling pathways that are + + + align:start position:0% +these growth signaling pathways that are +normally downstream of growth factors + + align:start position:0% +normally downstream of growth factors + + + align:start position:0% +normally downstream of growth factors +and receptor tyrosine kinase a--'s and + + align:start position:0% +and receptor tyrosine kinase a--'s and + + + align:start position:0% +and receptor tyrosine kinase a--'s and +if you hyper activate those you reduce + + align:start position:0% +if you hyper activate those you reduce + + + align:start position:0% +if you hyper activate those you reduce +the dependency of the cells on these + + align:start position:0% +the dependency of the cells on these + + + align:start position:0% +the dependency of the cells on these +signals okay so these oncogenic + + align:start position:0% +signals okay so these oncogenic + + + align:start position:0% +signals okay so these oncogenic +mutations can reduce the dependency of + + align:start position:0% +mutations can reduce the dependency of + + + align:start position:0% +mutations can reduce the dependency of +cells on growth factors and growth + + align:start position:0% +cells on growth factors and growth + + + align:start position:0% +cells on growth factors and growth +signals okay but one important point is + + align:start position:0% +signals okay but one important point is + + + align:start position:0% +signals okay but one important point is +that this is not enough okay and you can + + align:start position:0% +that this is not enough okay and you can + + + align:start position:0% +that this is not enough okay and you can +think about this in the case of the + + align:start position:0% +think about this in the case of the + + + align:start position:0% +think about this in the case of the +intestine because if you had an + + align:start position:0% +intestine because if you had an + + + align:start position:0% +intestine because if you had an +oncogenic mutation in one of these cells + + align:start position:0% +oncogenic mutation in one of these cells + + + align:start position:0% +oncogenic mutation in one of these cells +here it might not be as dependent on + + align:start position:0% +here it might not be as dependent on + + + align:start position:0% +here it might not be as dependent on +signals for growth but it doesn't matter + + align:start position:0% +signals for growth but it doesn't matter + + + align:start position:0% +signals for growth but it doesn't matter +because even though you had that + + align:start position:0% +because even though you had that + + + align:start position:0% +because even though you had that +mutation is gonna die and it's gonna + + align:start position:0% +mutation is gonna die and it's gonna + + + align:start position:0% +mutation is gonna die and it's gonna +shed out of the tissue okay and actually + + align:start position:0% +shed out of the tissue okay and actually + + + align:start position:0% +shed out of the tissue okay and actually +what happens in many cases where you + + align:start position:0% +what happens in many cases where you + + + align:start position:0% +what happens in many cases where you +activate a signaling pathway that allows + + align:start position:0% +activate a signaling pathway that allows + + + align:start position:0% +activate a signaling pathway that allows +the cell to in an abnormal way go + + align:start position:0% +the cell to in an abnormal way go + + + align:start position:0% +the cell to in an abnormal way go +through the cell cycle you actually + + align:start position:0% +through the cell cycle you actually + + + align:start position:0% +through the cell cycle you actually +induce a failsafe mechanism at the cell + + align:start position:0% +induce a failsafe mechanism at the cell + + + align:start position:0% +induce a failsafe mechanism at the cell +which causes a cell to undergo a p' + + align:start position:0% +which causes a cell to undergo a p' + + + align:start position:0% +which causes a cell to undergo a p' +ptosis okay so often you get this step + + align:start position:0% +ptosis okay so often you get this step + + + align:start position:0% +ptosis okay so often you get this step +happening and the cell just undergo + + align:start position:0% +happening and the cell just undergo + + + align:start position:0% +happening and the cell just undergo +apoptosis because you've evolved to + + align:start position:0% +apoptosis because you've evolved to + + + align:start position:0% +apoptosis because you've evolved to +protect your organs from this type of + + align:start position:0% +protect your organs from this type of + + + align:start position:0% +protect your organs from this type of +mutation so it's the oncogenic mutation + + align:start position:0% +mutation so it's the oncogenic mutation + + + align:start position:0% +mutation so it's the oncogenic mutation +in collaboration with loss of tumor + + align:start position:0% +in collaboration with loss of tumor + + + align:start position:0% +in collaboration with loss of tumor +suppression and one of the main tumor + + align:start position:0% +suppression and one of the main tumor + + + align:start position:0% +suppression and one of the main tumor +suppressive mechanisms our body has is + + align:start position:0% +suppressive mechanisms our body has is + + + align:start position:0% +suppressive mechanisms our body has is +apoptosis where if the cell is doing + + align:start position:0% +apoptosis where if the cell is doing + + + align:start position:0% +apoptosis where if the cell is doing +something abnormal the cell simply dies + + align:start position:0% +something abnormal the cell simply dies + + + align:start position:0% +something abnormal the cell simply dies +okay so so loss of a tumor suppressor + + align:start position:0% +okay so so loss of a tumor suppressor + + + align:start position:0% +okay so so loss of a tumor suppressor +could be loss of a gene that promotes + + align:start position:0% +could be loss of a gene that promotes + + + align:start position:0% +could be loss of a gene that promotes +apoptosis and in that case if the cell + + align:start position:0% +apoptosis and in that case if the cell + + + align:start position:0% +apoptosis and in that case if the cell +loses that mechanism the cell will avoid + + align:start position:0% +loses that mechanism the cell will avoid + + + align:start position:0% +loses that mechanism the cell will avoid +apoptosis + + align:start position:0% + + + + align:start position:0% + +okay so these are it seiz uncle genic + + align:start position:0% +okay so these are it seiz uncle genic + + + align:start position:0% +okay so these are it seiz uncle genic +and the los oncogenic mutations and the + + align:start position:0% +and the los oncogenic mutations and the + + + align:start position:0% +and the los oncogenic mutations and the +loss of tumor suppressors which subverts + + align:start position:0% +loss of tumor suppressors which subverts + + + align:start position:0% +loss of tumor suppressors which subverts +the normal communication between cells + + align:start position:0% +the normal communication between cells + + + align:start position:0% +the normal communication between cells +which is required for normal tissue + + align:start position:0% +which is required for normal tissue + + + align:start position:0% +which is required for normal tissue +homeostasis okay now another example of + + align:start position:0% +homeostasis okay now another example of + + + align:start position:0% +homeostasis okay now another example of +this growth in survival signaling is not + + align:start position:0% +this growth in survival signaling is not + + + align:start position:0% +this growth in survival signaling is not +one which involves necessarily a genetic + + align:start position:0% +one which involves necessarily a genetic + + + align:start position:0% +one which involves necessarily a genetic +change but one that involves changes in + + align:start position:0% +change but one that involves changes in + + + align:start position:0% +change but one that involves changes in +expression and it also involves + + align:start position:0% +expression and it also involves + + + align:start position:0% +expression and it also involves +interaction between the tumor and the + + align:start position:0% +interaction between the tumor and the + + + align:start position:0% +interaction between the tumor and the +surrounding cells of the body okay so + + align:start position:0% +surrounding cells of the body okay so + + + align:start position:0% +surrounding cells of the body okay so +I'm going to tell you a little bit about + + align:start position:0% +I'm going to tell you a little bit about + + + align:start position:0% +I'm going to tell you a little bit about +tumor micro-environment and this is + + align:start position:0% +tumor micro-environment and this is + + + align:start position:0% +tumor micro-environment and this is +something that's important to consider + + align:start position:0% +something that's important to consider + + + align:start position:0% +something that's important to consider +in cancer because you know a tumor in + + align:start position:0% +in cancer because you know a tumor in + + + align:start position:0% +in cancer because you know a tumor in +the body it's not an isolation it's + + align:start position:0% +the body it's not an isolation it's + + + align:start position:0% +the body it's not an isolation it's +surrounded by other cells in your body + + align:start position:0% +surrounded by other cells in your body + + + align:start position:0% +surrounded by other cells in your body +and other things in your body okay like + + align:start position:0% +and other things in your body okay like + + + align:start position:0% +and other things in your body okay like +matrix and so here's a picture showing + + align:start position:0% +matrix and so here's a picture showing + + + align:start position:0% +matrix and so here's a picture showing +you a tumor and the tumor is stained + + align:start position:0% +you a tumor and the tumor is stained + + + align:start position:0% +you a tumor and the tumor is stained +with this membrane protein which is + + align:start position:0% +with this membrane protein which is + + + align:start position:0% +with this membrane protein which is +shown here in the rust color so that's + + align:start position:0% +shown here in the rust color so that's + + + align:start position:0% +shown here in the rust color so that's +the tumor and what's also stained in + + align:start position:0% +the tumor and what's also stained in + + + align:start position:0% +the tumor and what's also stained in +this in this piece of tissue is the DNA + + align:start position:0% +this in this piece of tissue is the DNA + + + align:start position:0% +this in this piece of tissue is the DNA +it's stained in blue and so you see the + + align:start position:0% +it's stained in blue and so you see the + + + align:start position:0% +it's stained in blue and so you see the +nuclei of the tumor cells in there but + + align:start position:0% +nuclei of the tumor cells in there but + + + align:start position:0% +nuclei of the tumor cells in there but +you see all these blue nuclei + + align:start position:0% +you see all these blue nuclei + + + align:start position:0% +you see all these blue nuclei +surrounding the tumor and these are + + align:start position:0% +surrounding the tumor and these are + + + align:start position:0% +surrounding the tumor and these are +stromal cells that are around the tumor + + align:start position:0% +stromal cells that are around the tumor + + + align:start position:0% +stromal cells that are around the tumor +and they've actually been recruited to + + align:start position:0% +and they've actually been recruited to + + + align:start position:0% +and they've actually been recruited to +the tumor by the cancer cells okay so in + + align:start position:0% +the tumor by the cancer cells okay so in + + + align:start position:0% +the tumor by the cancer cells okay so in +what I mean by tumor micro-environment + + align:start position:0% +what I mean by tumor micro-environment + + + align:start position:0% +what I mean by tumor micro-environment +is just a region around the tumor okay + + align:start position:0% +is just a region around the tumor okay + + + align:start position:0% +is just a region around the tumor okay +and so if you have a cancer and you have + + align:start position:0% +and so if you have a cancer and you have + + + align:start position:0% +and so if you have a cancer and you have +a tumor the tumor cells can actually + + align:start position:0% +a tumor the tumor cells can actually + + + align:start position:0% +a tumor the tumor cells can actually +secrete signals which recruit stromal + + align:start position:0% +secrete signals which recruit stromal + + + align:start position:0% +secrete signals which recruit stromal +cells okay so there can be a interaction + + align:start position:0% +cells okay so there can be a interaction + + + align:start position:0% +cells okay so there can be a interaction +where the tumor sends recruitment + + align:start position:0% +where the tumor sends recruitment + + + align:start position:0% +where the tumor sends recruitment +signals that causes stromal cells to + + align:start position:0% +signals that causes stromal cells to + + + align:start position:0% +signals that causes stromal cells to +come by and what the stromal cells can + + align:start position:0% +come by and what the stromal cells can + + + align:start position:0% +come by and what the stromal cells can +do what they do for the tumor and why + + align:start position:0% +do what they do for the tumor and why + + + align:start position:0% +do what they do for the tumor and why +this is beneficial for the tumor is that + + align:start position:0% +this is beneficial for the tumor is that + + + align:start position:0% +this is beneficial for the tumor is that +stromal cells can secrete growth signals + + align:start position:0% +stromal cells can secrete growth signals + + + align:start position:0% +stromal cells can secrete growth signals +or survival signals that promote the + + align:start position:0% +or survival signals that promote the + + + align:start position:0% +or survival signals that promote the +growth of the tumor okay so there can be + + align:start position:0% +growth of the tumor okay so there can be + + + align:start position:0% +growth of the tumor okay so there can be +a reciprocal interaction here where you + + align:start position:0% +a reciprocal interaction here where you + + + align:start position:0% +a reciprocal interaction here where you +get a abnormal conversation between + + align:start position:0% +get a abnormal conversation between + + + align:start position:0% +get a abnormal conversation between +cancer cells and the surrounding stromal + + align:start position:0% +cancer cells and the surrounding stromal + + + align:start position:0% +cancer cells and the surrounding stromal +cells but again this is very similar if + + align:start position:0% +cells but again this is very similar if + + + align:start position:0% +cells but again this is very similar if +you think about it to the way a normal + + align:start position:0% +you think about it to the way a normal + + + align:start position:0% +you think about it to the way a normal +organ works right you you often have + + align:start position:0% +organ works right you you often have + + + align:start position:0% +organ works right you you often have +these signals going between cells and + + align:start position:0% +these signals going between cells and + + + align:start position:0% +these signals going between cells and +that is involved in normal tissue + + align:start position:0% +that is involved in normal tissue + + + align:start position:0% +that is involved in normal tissue +homeostasis what's happening here though + + align:start position:0% +homeostasis what's happening here though + + + align:start position:0% +homeostasis what's happening here though +is abnormal and that the cancer cells + + align:start position:0% +is abnormal and that the cancer cells + + + align:start position:0% +is abnormal and that the cancer cells +are constitutively recruiting these + + align:start position:0% +are constitutively recruiting these + + + align:start position:0% +are constitutively recruiting these +stromal cells just to get this growth + + align:start position:0% +stromal cells just to get this growth + + + align:start position:0% +stromal cells just to get this growth +signal that they're addicted to and + + align:start position:0% +signal that they're addicted to and + + + align:start position:0% +signal that they're addicted to and +because you have just the presence of + + align:start position:0% +because you have just the presence of + + + align:start position:0% +because you have just the presence of +such a loop suggests that these cancer + + align:start position:0% +such a loop suggests that these cancer + + + align:start position:0% +such a loop suggests that these cancer +cells even if they have oncogenic + + align:start position:0% +cells even if they have oncogenic + + + align:start position:0% +cells even if they have oncogenic +mutations and lost have lost tumor + + align:start position:0% +mutations and lost have lost tumor + + + align:start position:0% +mutations and lost have lost tumor +suppressors they are not totally + + align:start position:0% +suppressors they are not totally + + + align:start position:0% +suppressors they are not totally +independent of growth signals they still + + align:start position:0% +independent of growth signals they still + + + align:start position:0% +independent of growth signals they still +to some extent rely on growth signals + + align:start position:0% +to some extent rely on growth signals + + + align:start position:0% +to some extent rely on growth signals +okay so these oncogenic mutations they + + align:start position:0% +okay so these oncogenic mutations they + + + align:start position:0% +okay so these oncogenic mutations they +reduce the dependency on growth signals + + align:start position:0% +reduce the dependency on growth signals + + + align:start position:0% +reduce the dependency on growth signals +but this dependency the dependency on + + align:start position:0% +but this dependency the dependency on + + + align:start position:0% +but this dependency the dependency on +growth signals is not eliminated okay + + align:start position:0% + + + + align:start position:0% + +and one experiment that showed this was + + align:start position:0% +and one experiment that showed this was + + + align:start position:0% +and one experiment that showed this was +an experiment that was done back in the + + align:start position:0% +an experiment that was done back in the + + + align:start position:0% +an experiment that was done back in the +1950s where patients with a type of skin + + align:start position:0% +1950s where patients with a type of skin + + + align:start position:0% +1950s where patients with a type of skin +cancer basal cell carcinoma were taken + + align:start position:0% +cancer basal cell carcinoma were taken + + + align:start position:0% +cancer basal cell carcinoma were taken +and they had their tumors excised from + + align:start position:0% +and they had their tumors excised from + + + align:start position:0% +and they had their tumors excised from +one part of their body and then the + + align:start position:0% +one part of their body and then the + + + align:start position:0% +one part of their body and then the +tumor was grafted on back onto them to + + align:start position:0% +tumor was grafted on back onto them to + + + align:start position:0% +tumor was grafted on back onto them to +another part of their body distant from + + align:start position:0% +another part of their body distant from + + + align:start position:0% +another part of their body distant from +the original site of the tumor and this + + align:start position:0% +the original site of the tumor and this + + + align:start position:0% +the original site of the tumor and this +grafting experiment was done either with + + align:start position:0% +grafting experiment was done either with + + + align:start position:0% +grafting experiment was done either with +the stromal cells that surrounded the + + align:start position:0% +the stromal cells that surrounded the + + + align:start position:0% +the stromal cells that surrounded the +tumor or the stromal cells surrounding + + align:start position:0% +tumor or the stromal cells surrounding + + + align:start position:0% +tumor or the stromal cells surrounding +the tumor were removed in just the tumor + + align:start position:0% +the tumor were removed in just the tumor + + + align:start position:0% +the tumor were removed in just the tumor +cells were grafted back on to the body + + align:start position:0% +cells were grafted back on to the body + + + align:start position:0% +cells were grafted back on to the body +okay now this experiment probably would + + align:start position:0% +okay now this experiment probably would + + + align:start position:0% +okay now this experiment probably would +not be allowed today but back in the 50s + + align:start position:0% +not be allowed today but back in the 50s + + + align:start position:0% +not be allowed today but back in the 50s +I guess it was legal and so the + + align:start position:0% +I guess it was legal and so the + + + align:start position:0% +I guess it was legal and so the +experimental result is that if you + + align:start position:0% +experimental result is that if you + + + align:start position:0% +experimental result is that if you +graphed the tumor cells with the + + align:start position:0% +graphed the tumor cells with the + + + align:start position:0% +graphed the tumor cells with the +surrounding stroma the tumor was able to + + align:start position:0% +surrounding stroma the tumor was able to + + + align:start position:0% +surrounding stroma the tumor was able to +establish a second tumor or the tumor + + align:start position:0% +establish a second tumor or the tumor + + + align:start position:0% +establish a second tumor or the tumor +cells survived this this grafting + + align:start position:0% +cells survived this this grafting + + + align:start position:0% +cells survived this this grafting +procedure where as tumor cells that were + + align:start position:0% +procedure where as tumor cells that were + + + align:start position:0% +procedure where as tumor cells that were +taken without the stroma underwent cell + + align:start position:0% +taken without the stroma underwent cell + + + align:start position:0% +taken without the stroma underwent cell +death when they were put in a new + + align:start position:0% +death when they were put in a new + + + align:start position:0% +death when they were put in a new +location okay so there's something about + + align:start position:0% +location okay so there's something about + + + align:start position:0% +location okay so there's something about +this specialized micro environment that + + align:start position:0% +this specialized micro environment that + + + align:start position:0% +this specialized micro environment that +the tumor creates for itself that is + + align:start position:0% +the tumor creates for itself that is + + + align:start position:0% +the tumor creates for itself that is +enabling the tumor to grow and survive + + align:start position:0% +enabling the tumor to grow and survive + + + align:start position:0% +enabling the tumor to grow and survive +okay and the model is is that it's + + align:start position:0% +okay and the model is is that it's + + + align:start position:0% +okay and the model is is that it's +because these stromal cells are + + align:start position:0% +because these stromal cells are + + + align:start position:0% +because these stromal cells are +secreting growth factors that these + + align:start position:0% +secreting growth factors that these + + + align:start position:0% +secreting growth factors that these +cancer cells are still dependent on + + align:start position:0% + + + + align:start position:0% + +so this dependency on growth signals is + + align:start position:0% +so this dependency on growth signals is + + + align:start position:0% +so this dependency on growth signals is +important clinically because some some + + align:start position:0% +important clinically because some some + + + align:start position:0% +important clinically because some some +types of cancer there is an elevation of + + align:start position:0% +types of cancer there is an elevation of + + + align:start position:0% +types of cancer there is an elevation of +growth factor receptors that are + + align:start position:0% +growth factor receptors that are + + + align:start position:0% +growth factor receptors that are +associated with the cancer and the + + align:start position:0% +associated with the cancer and the + + + align:start position:0% +associated with the cancer and the +famous example of that is in 30% of + + align:start position:0% +famous example of that is in 30% of + + + align:start position:0% +famous example of that is in 30% of +breast cancers there is a growth factor + + align:start position:0% +breast cancers there is a growth factor + + + align:start position:0% +breast cancers there is a growth factor +receptor the her2 receptor which is + + align:start position:0% +receptor the her2 receptor which is + + + align:start position:0% +receptor the her2 receptor which is +overexpressed in the cancer cells okay + + align:start position:0% +overexpressed in the cancer cells okay + + + align:start position:0% +overexpressed in the cancer cells okay +so I just drew a receptor here and I'm + + align:start position:0% +so I just drew a receptor here and I'm + + + align:start position:0% +so I just drew a receptor here and I'm +now talking about the her2 receptor her2 + + align:start position:0% +now talking about the her2 receptor her2 + + + align:start position:0% +now talking about the her2 receptor her2 +stands for human epidermal growth factor + + align:start position:0% +stands for human epidermal growth factor + + + align:start position:0% +stands for human epidermal growth factor +EGF receptor - okay so that's this is a + + align:start position:0% +EGF receptor - okay so that's this is a + + + align:start position:0% +EGF receptor - okay so that's this is a +receptor tyrosine kinase which is a + + align:start position:0% +receptor tyrosine kinase which is a + + + align:start position:0% +receptor tyrosine kinase which is a +transmembrane protein receptor it's + + align:start position:0% +transmembrane protein receptor it's + + + align:start position:0% +transmembrane protein receptor it's +expressed on the surface of the cell and + + align:start position:0% +expressed on the surface of the cell and + + + align:start position:0% +expressed on the surface of the cell and +so about 30% of human breast cancers are + + align:start position:0% +so about 30% of human breast cancers are + + + align:start position:0% +so about 30% of human breast cancers are +her to posit positive which means that + + align:start position:0% +her to posit positive which means that + + + align:start position:0% +her to posit positive which means that +the cancer cells are over expressing + + align:start position:0% +the cancer cells are over expressing + + + align:start position:0% +the cancer cells are over expressing +this receptor tyrosine kinase the fact + + align:start position:0% +this receptor tyrosine kinase the fact + + + align:start position:0% +this receptor tyrosine kinase the fact +that you have these these cancer cells + + align:start position:0% +that you have these these cancer cells + + + align:start position:0% +that you have these these cancer cells +over expressing a growth factor receptor + + align:start position:0% +over expressing a growth factor receptor + + + align:start position:0% +over expressing a growth factor receptor +suggests that the cancer is requires + + align:start position:0% +suggests that the cancer is requires + + + align:start position:0% +suggests that the cancer is requires +some type of growth stimulus in order + + align:start position:0% +some type of growth stimulus in order + + + align:start position:0% +some type of growth stimulus in order +for the cancer to be growing okay and + + align:start position:0% +for the cancer to be growing okay and + + + align:start position:0% +for the cancer to be growing okay and +the fact that this was discovered that + + align:start position:0% +the fact that this was discovered that + + + align:start position:0% +the fact that this was discovered that +30% of breast cancers overexpress her2 + + align:start position:0% +30% of breast cancers overexpress her2 + + + align:start position:0% +30% of breast cancers overexpress her2 +has been used by researchers to develop + + align:start position:0% +has been used by researchers to develop + + + align:start position:0% +has been used by researchers to develop +a treatment for this type of cancer + + align:start position:0% +a treatment for this type of cancer + + + align:start position:0% +a treatment for this type of cancer +that's her2 positive the treatment is + + align:start position:0% +that's her2 positive the treatment is + + + align:start position:0% +that's her2 positive the treatment is +known as Herceptin possibly some of you + + align:start position:0% +known as Herceptin possibly some of you + + + align:start position:0% +known as Herceptin possibly some of you +have heard of this + + align:start position:0% +have heard of this + + + align:start position:0% +have heard of this +it was developed at Genentech and what + + align:start position:0% +it was developed at Genentech and what + + + align:start position:0% +it was developed at Genentech and what +Herceptin is is + + align:start position:0% +Herceptin is is + + + align:start position:0% +Herceptin is is +it's an antibody that was raised against + + align:start position:0% +it's an antibody that was raised against + + + align:start position:0% +it's an antibody that was raised against +the human her2 protein + + align:start position:0% +the human her2 protein + + + align:start position:0% +the human her2 protein +okay so Herceptin is an antibody it + + align:start position:0% +okay so Herceptin is an antibody it + + + align:start position:0% +okay so Herceptin is an antibody it +recognizes her two on the surface of + + align:start position:0% +recognizes her two on the surface of + + + align:start position:0% +recognizes her two on the surface of +these cancer cells and if you you can + + align:start position:0% +these cancer cells and if you you can + + + align:start position:0% +these cancer cells and if you you can +treat patients with this antibody and + + align:start position:0% +treat patients with this antibody and + + + align:start position:0% +treat patients with this antibody and +that antibody binds to the her2 positive + + align:start position:0% +that antibody binds to the her2 positive + + + align:start position:0% +that antibody binds to the her2 positive +cells and either blocks the function of + + align:start position:0% +cells and either blocks the function of + + + align:start position:0% +cells and either blocks the function of +her - or recruits immune cells to kill + + align:start position:0% +her - or recruits immune cells to kill + + + align:start position:0% +her - or recruits immune cells to kill +those cells off okay the exact mechanism + + align:start position:0% +those cells off okay the exact mechanism + + + align:start position:0% +those cells off okay the exact mechanism +I don't believe is known but what is + + align:start position:0% +I don't believe is known but what is + + + align:start position:0% +I don't believe is known but what is +known is that Herceptin has really + + align:start position:0% +known is that Herceptin has really + + + align:start position:0% +known is that Herceptin has really +changed how we're able to treat her to + + align:start position:0% +changed how we're able to treat her to + + + align:start position:0% +changed how we're able to treat her to +positive breast cancers and it's been a + + align:start position:0% +positive breast cancers and it's been a + + + align:start position:0% +positive breast cancers and it's been a +huge success story in the fight against + + align:start position:0% +huge success story in the fight against + + + align:start position:0% +huge success story in the fight against +cancer + + align:start position:0% + + + + align:start position:0% + +all right so we've talked about this + + align:start position:0% +all right so we've talked about this + + + align:start position:0% +all right so we've talked about this +first barrier there barrier to tumor + + align:start position:0% +first barrier there barrier to tumor + + + align:start position:0% +first barrier there barrier to tumor +cells becoming at least semi independent + + align:start position:0% +cells becoming at least semi independent + + + align:start position:0% +cells becoming at least semi independent +of these growth factors and so now I + + align:start position:0% +of these growth factors and so now I + + + align:start position:0% +of these growth factors and so now I +want to talk about other barriers to + + align:start position:0% +want to talk about other barriers to + + + align:start position:0% +want to talk about other barriers to +tumorigenesis right and if you consider + + align:start position:0% +tumorigenesis right and if you consider + + + align:start position:0% +tumorigenesis right and if you consider +an epithelial cell here right even if + + align:start position:0% +an epithelial cell here right even if + + + align:start position:0% +an epithelial cell here right even if +these cells are able to grow they won't + + align:start position:0% +these cells are able to grow they won't + + + align:start position:0% +these cells are able to grow they won't +be able to leave the organ until + + align:start position:0% +be able to leave the organ until + + + align:start position:0% +be able to leave the organ until +something else happens and one thing + + align:start position:0% +something else happens and one thing + + + align:start position:0% +something else happens and one thing +that would need to happen for these + + align:start position:0% +that would need to happen for these + + + align:start position:0% +that would need to happen for these +cells to become malignant and to leave + + align:start position:0% +cells to become malignant and to leave + + + align:start position:0% +cells to become malignant and to leave +the organ that they were initially part + + align:start position:0% +the organ that they were initially part + + + align:start position:0% +the organ that they were initially part +of is for there to be a breakdown in the + + align:start position:0% +of is for there to be a breakdown in the + + + align:start position:0% +of is for there to be a breakdown in the +adhesion between cells so for the next + + align:start position:0% +adhesion between cells so for the next + + + align:start position:0% +adhesion between cells so for the next +few minutes I want to talk about the + + align:start position:0% +few minutes I want to talk about the + + + align:start position:0% +few minutes I want to talk about the +breakdown in cell to cell adhesion okay + + align:start position:0% +breakdown in cell to cell adhesion okay + + + align:start position:0% +breakdown in cell to cell adhesion okay +so how what is what a cancer cell + + align:start position:0% +so how what is what a cancer cell + + + align:start position:0% +so how what is what a cancer cell +basically unstick itself from the cells + + align:start position:0% +basically unstick itself from the cells + + + align:start position:0% +basically unstick itself from the cells +that surround it in order to leave an + + align:start position:0% +that surround it in order to leave an + + + align:start position:0% +that surround it in order to leave an +organ and go somewhere else and for that + + align:start position:0% +organ and go somewhere else and for that + + + align:start position:0% +organ and go somewhere else and for that +to explain that I have to remind you + + align:start position:0% +to explain that I have to remind you + + + align:start position:0% +to explain that I have to remind you +about some of the normal biology of + + align:start position:0% +about some of the normal biology of + + + align:start position:0% +about some of the normal biology of +these epithelial cells which we talked + + align:start position:0% +these epithelial cells which we talked + + + align:start position:0% +these epithelial cells which we talked +about earlier which is that they express + + align:start position:0% +about earlier which is that they express + + + align:start position:0% +about earlier which is that they express +these transmembrane proteins that are + + align:start position:0% +these transmembrane proteins that are + + + align:start position:0% +these transmembrane proteins that are +adhesion proteins okay so normally + + align:start position:0% +adhesion proteins okay so normally + + + align:start position:0% +adhesion proteins okay so normally +epithelial cells have adhesion proteins + + align:start position:0% +epithelial cells have adhesion proteins + + + align:start position:0% +epithelial cells have adhesion proteins +and the famous one for epithelia or one + + align:start position:0% +and the famous one for epithelia or one + + + align:start position:0% +and the famous one for epithelia or one +of the famous ones is called epithelial + + align:start position:0% +of the famous ones is called epithelial + + + align:start position:0% +of the famous ones is called epithelial +or e-cat hiren and ecad hiren is a + + align:start position:0% +or e-cat hiren and ecad hiren is a + + + align:start position:0% +or e-cat hiren and ecad hiren is a +transmembrane protein it has a + + align:start position:0% +transmembrane protein it has a + + + align:start position:0% +transmembrane protein it has a +extracellular domain but rather than + + align:start position:0% +extracellular domain but rather than + + + align:start position:0% +extracellular domain but rather than +that extracellular domain binding to + + align:start position:0% +that extracellular domain binding to + + + align:start position:0% +that extracellular domain binding to +some secreted ligand this extracellular + + align:start position:0% +some secreted ligand this extracellular + + + align:start position:0% +some secreted ligand this extracellular +domain recognizes ich adhere in + + align:start position:0% +domain recognizes ich adhere in + + + align:start position:0% +domain recognizes ich adhere in +molecules on other cells and they stick + + align:start position:0% +molecules on other cells and they stick + + + align:start position:0% +molecules on other cells and they stick +to each + + align:start position:0% +to each + + + align:start position:0% +to each +and it essentially functions like + + align:start position:0% +and it essentially functions like + + + align:start position:0% +and it essentially functions like +cellular velcro okay so the cells link + + align:start position:0% +cellular velcro okay so the cells link + + + align:start position:0% +cellular velcro okay so the cells link +together and they stick to each other + + align:start position:0% +together and they stick to each other + + + align:start position:0% +together and they stick to each other +such that they form a coherent tissue + + align:start position:0% +such that they form a coherent tissue + + + align:start position:0% +such that they form a coherent tissue +okay so the way that cancer cells + + align:start position:0% +okay so the way that cancer cells + + + align:start position:0% +okay so the way that cancer cells +subvert this mechanism of adhesion is + + align:start position:0% +subvert this mechanism of adhesion is + + + align:start position:0% +subvert this mechanism of adhesion is +they have to do something that inhibits + + align:start position:0% +they have to do something that inhibits + + + align:start position:0% +they have to do something that inhibits +ECOD hiren and so cancer cells what what + + align:start position:0% +ECOD hiren and so cancer cells what what + + + align:start position:0% +ECOD hiren and so cancer cells what what +they can do is to decrease this cell T + + align:start position:0% +they can do is to decrease this cell T + + + align:start position:0% +they can do is to decrease this cell T +cell adhesion and I'll tell you how in + + align:start position:0% +cell adhesion and I'll tell you how in + + + align:start position:0% +cell adhesion and I'll tell you how in +just a minute and in addition to + + align:start position:0% +just a minute and in addition to + + + align:start position:0% +just a minute and in addition to +decreasing this cell to cell adhesion + + align:start position:0% +decreasing this cell to cell adhesion + + + align:start position:0% +decreasing this cell to cell adhesion +they can also promote the genes that are + + align:start position:0% +they can also promote the genes that are + + + align:start position:0% +they can also promote the genes that are +involved in motility + + align:start position:0% + + + + align:start position:0% + +okay so we have to understand then how + + align:start position:0% +okay so we have to understand then how + + + align:start position:0% +okay so we have to understand then how +it is a cancer cell would do both of + + align:start position:0% +it is a cancer cell would do both of + + + align:start position:0% +it is a cancer cell would do both of +these things and I'll start with cell to + + align:start position:0% +these things and I'll start with cell to + + + align:start position:0% +these things and I'll start with cell to +cell adhesion and in contrast to what + + align:start position:0% +cell adhesion and in contrast to what + + + align:start position:0% +cell adhesion and in contrast to what +we've talked about with the growth and + + align:start position:0% +we've talked about with the growth and + + + align:start position:0% +we've talked about with the growth and +survival signaling where you have + + align:start position:0% +survival signaling where you have + + + align:start position:0% +survival signaling where you have +mutations that happen in cancer cells + + align:start position:0% +mutations that happen in cancer cells + + + align:start position:0% +mutations that happen in cancer cells +and you basically have an irreversible + + align:start position:0% +and you basically have an irreversible + + + align:start position:0% +and you basically have an irreversible +change to the genome of the cell this + + align:start position:0% +change to the genome of the cell this + + + align:start position:0% +change to the genome of the cell this +change in in the adhesive properties of + + align:start position:0% +change in in the adhesive properties of + + + align:start position:0% +change in in the adhesive properties of +the cell and essentially their cell + + align:start position:0% +the cell and essentially their cell + + + align:start position:0% +the cell and essentially their cell +state right because what you see here if + + align:start position:0% +state right because what you see here if + + + align:start position:0% +state right because what you see here if +a cancer cell is having less adhesion + + align:start position:0% +a cancer cell is having less adhesion + + + align:start position:0% +a cancer cell is having less adhesion +and getting more migratory its switching + + align:start position:0% +and getting more migratory its switching + + + align:start position:0% +and getting more migratory its switching +from an epithelial type of state to a + + align:start position:0% +from an epithelial type of state to a + + + align:start position:0% +from an epithelial type of state to a +mesenchymal type of State okay and what + + align:start position:0% +mesenchymal type of State okay and what + + + align:start position:0% +mesenchymal type of State okay and what +this is called is an epithelial to + + align:start position:0% +this is called is an epithelial to + + + align:start position:0% +this is called is an epithelial to +mesenchymal transition and that is EMT + + align:start position:0% +mesenchymal transition and that is EMT + + + align:start position:0% +mesenchymal transition and that is EMT +for short okay and this EMT is not a + + align:start position:0% +for short okay and this EMT is not a + + + align:start position:0% +for short okay and this EMT is not a +genetic change it's not caused by a + + align:start position:0% +genetic change it's not caused by a + + + align:start position:0% +genetic change it's not caused by a +genetic change but it appears that EMT + + align:start position:0% +genetic change but it appears that EMT + + + align:start position:0% +genetic change but it appears that EMT +results from changes in gene regulation + + align:start position:0% +results from changes in gene regulation + + + align:start position:0% +results from changes in gene regulation +so you can think of it as more of an + + align:start position:0% +so you can think of it as more of an + + + align:start position:0% +so you can think of it as more of an +epigenetic change an epigenetic + + align:start position:0% + + + + align:start position:0% + +epigenetic change change in gene + + align:start position:0% +epigenetic change change in gene + + + align:start position:0% +epigenetic change change in gene +expression so there's a change in gene + + align:start position:0% +expression so there's a change in gene + + + align:start position:0% +expression so there's a change in gene +expression such that this can reverse + + align:start position:0% +expression such that this can reverse + + + align:start position:0% +expression such that this can reverse +later on + + align:start position:0% + + + + align:start position:0% + +okay and there are master regulators of + + align:start position:0% +okay and there are master regulators of + + + align:start position:0% +okay and there are master regulators of +this process which alter gene expression + + align:start position:0% +this process which alter gene expression + + + align:start position:0% +this process which alter gene expression +and so the type of gene that alters gene + + align:start position:0% +and so the type of gene that alters gene + + + align:start position:0% +and so the type of gene that alters gene +expression these are also often called + + align:start position:0% +expression these are also often called + + + align:start position:0% +expression these are also often called +transcription factors and there are + + align:start position:0% +transcription factors and there are + + + align:start position:0% +transcription factors and there are +several transcription factors that are + + align:start position:0% +several transcription factors that are + + + align:start position:0% +several transcription factors that are +master regulators of this EMT process + + align:start position:0% +master regulators of this EMT process + + + align:start position:0% +master regulators of this EMT process +and their names are twist snail another + + align:start position:0% +and their names are twist snail another + + + align:start position:0% +and their names are twist snail another +one's called slug there's an escargot + + align:start position:0% +one's called slug there's an escargot + + + align:start position:0% +one's called slug there's an escargot +you can see this got a little out of + + align:start position:0% +you can see this got a little out of + + + align:start position:0% +you can see this got a little out of +hand and you can tell by the names that + + align:start position:0% +hand and you can tell by the names that + + + align:start position:0% +hand and you can tell by the names that +they probably were not discovered in + + align:start position:0% +they probably were not discovered in + + + align:start position:0% +they probably were not discovered in +humans and in fact these genes were + + align:start position:0% +humans and in fact these genes were + + + align:start position:0% +humans and in fact these genes were +discovered in the same genetic screen + + align:start position:0% +discovered in the same genetic screen + + + align:start position:0% +discovered in the same genetic screen +that I outlined before where Hedgehog + + align:start position:0% +that I outlined before where Hedgehog + + + align:start position:0% +that I outlined before where Hedgehog +was discovered okay so it was a genetic + + align:start position:0% +was discovered okay so it was a genetic + + + align:start position:0% +was discovered okay so it was a genetic +screen and the flies and it was these + + align:start position:0% +screen and the flies and it was these + + + align:start position:0% +screen and the flies and it was these +are genes that affect the embryonic + + align:start position:0% +are genes that affect the embryonic + + + align:start position:0% +are genes that affect the embryonic +development of the fly and I'll show you + + align:start position:0% +development of the fly and I'll show you + + + align:start position:0% +development of the fly and I'll show you +this this view of the fly embryo so this + + align:start position:0% +this this view of the fly embryo so this + + + align:start position:0% +this this view of the fly embryo so this +is an embryo here and you see it's an + + align:start position:0% +is an embryo here and you see it's an + + + align:start position:0% +is an embryo here and you see it's an +epithelial sheet surrounding the yolk + + align:start position:0% +epithelial sheet surrounding the yolk + + + align:start position:0% +epithelial sheet surrounding the yolk +and what happens is in early stages of + + align:start position:0% +and what happens is in early stages of + + + align:start position:0% +and what happens is in early stages of +development a population of cells + + align:start position:0% +development a population of cells + + + align:start position:0% +development a population of cells +expressed the twist gene so that's twist + + align:start position:0% +expressed the twist gene so that's twist + + + align:start position:0% +expressed the twist gene so that's twist +in the dark here and this twist gene + + align:start position:0% +in the dark here and this twist gene + + + align:start position:0% +in the dark here and this twist gene +causes these cells to basically invade + + align:start position:0% +causes these cells to basically invade + + + align:start position:0% +causes these cells to basically invade +into the middle of the embryo okay so + + align:start position:0% +into the middle of the embryo okay so + + + align:start position:0% +into the middle of the embryo okay so +here are the twist cells now going into + + align:start position:0% +here are the twist cells now going into + + + align:start position:0% +here are the twist cells now going into +the inside of the embryo and then the + + align:start position:0% +the inside of the embryo and then the + + + align:start position:0% +the inside of the embryo and then the +cells undergo EMT and they start to + + align:start position:0% +cells undergo EMT and they start to + + + align:start position:0% +cells undergo EMT and they start to +migrate around inside the embryo okay + + align:start position:0% +migrate around inside the embryo okay + + + align:start position:0% +migrate around inside the embryo okay +what this is doing for the fly is that + + align:start position:0% +what this is doing for the fly is that + + + align:start position:0% +what this is doing for the fly is that +these are the cells that are going on to + + align:start position:0% +these are the cells that are going on to + + + align:start position:0% +these are the cells that are going on to +form the muscle okay and if you look at + + align:start position:0% +form the muscle okay and if you look at + + + align:start position:0% +form the muscle okay and if you look at +your neighbor you might notice that + + align:start position:0% +your neighbor you might notice that + + + align:start position:0% +your neighbor you might notice that +their muscles are on the inside of their + + align:start position:0% +their muscles are on the inside of their + + + align:start position:0% +their muscles are on the inside of their +body okay so this this process is + + align:start position:0% +body okay so this this process is + + + align:start position:0% +body okay so this this process is +basically putting + + align:start position:0% +basically putting + + + align:start position:0% +basically putting +these cells by getting them to move its + + align:start position:0% +these cells by getting them to move its + + + align:start position:0% +these cells by getting them to move its +putting the cells in the right place for + + align:start position:0% +putting the cells in the right place for + + + align:start position:0% +putting the cells in the right place for +what they are going to differentiate + + align:start position:0% +what they are going to differentiate + + + align:start position:0% +what they are going to differentiate +into during embryonic development okay + + align:start position:0% +into during embryonic development okay + + + align:start position:0% +into during embryonic development okay +and so but this this process if + + align:start position:0% +and so but this this process if + + + align:start position:0% +and so but this this process if +activated during cancer can allow these + + align:start position:0% +activated during cancer can allow these + + + align:start position:0% +activated during cancer can allow these +cells to be more mobile mobile and to + + align:start position:0% +cells to be more mobile mobile and to + + + align:start position:0% +cells to be more mobile mobile and to +leave one organ and go into another + + align:start position:0% +leave one organ and go into another + + + align:start position:0% +leave one organ and go into another +organ okay so cancer isn't inventing + + align:start position:0% +organ okay so cancer isn't inventing + + + align:start position:0% +organ okay so cancer isn't inventing +anything new here it's corrupting a + + align:start position:0% +anything new here it's corrupting a + + + align:start position:0% +anything new here it's corrupting a +normal program that cells have a need + + align:start position:0% +normal program that cells have a need + + + align:start position:0% +normal program that cells have a need +during development and it's in + + align:start position:0% +during development and it's in + + + align:start position:0% +during development and it's in +activating it at an inappropriate time + + align:start position:0% +activating it at an inappropriate time + + + align:start position:0% +activating it at an inappropriate time +okay so these are all transcription + + align:start position:0% +okay so these are all transcription + + + align:start position:0% +okay so these are all transcription +factors and what they do is they repress + + align:start position:0% +factors and what they do is they repress + + + align:start position:0% +factors and what they do is they repress +the expression or function of kid hearin + + align:start position:0% +the expression or function of kid hearin + + + align:start position:0% +the expression or function of kid hearin +such that the cells are no longer as + + align:start position:0% +such that the cells are no longer as + + + align:start position:0% +such that the cells are no longer as +sticky okay so they basically when these + + align:start position:0% +sticky okay so they basically when these + + + align:start position:0% +sticky okay so they basically when these +transcription factors get turned on + + align:start position:0% +transcription factors get turned on + + + align:start position:0% +transcription factors get turned on +it makes the cells less sticky to each + + align:start position:0% +it makes the cells less sticky to each + + + align:start position:0% +it makes the cells less sticky to each +other and it also promotes their + + align:start position:0% +other and it also promotes their + + + align:start position:0% +other and it also promotes their +migration so it turns on genes that are + + align:start position:0% +migration so it turns on genes that are + + + align:start position:0% +migration so it turns on genes that are +important for migration this process of + + align:start position:0% +important for migration this process of + + + align:start position:0% +important for migration this process of +EMT as I mentioned is reversible and it + + align:start position:0% +EMT as I mentioned is reversible and it + + + align:start position:0% +EMT as I mentioned is reversible and it +also involves interactions between tumor + + align:start position:0% +also involves interactions between tumor + + + align:start position:0% +also involves interactions between tumor +and stromal cells I'll show you an + + align:start position:0% +and stromal cells I'll show you an + + + align:start position:0% +and stromal cells I'll show you an +example of so in the fly embryo one + + align:start position:0% +example of so in the fly embryo one + + + align:start position:0% +example of so in the fly embryo one +thing that's nice about the Flies is you + + align:start position:0% +thing that's nice about the Flies is you + + + align:start position:0% +thing that's nice about the Flies is you +can actually watch this happen live and + + align:start position:0% +can actually watch this happen live and + + + align:start position:0% +can actually watch this happen live and +so I'm gonna show you a movie now + + align:start position:0% +so I'm gonna show you a movie now + + + align:start position:0% +so I'm gonna show you a movie now +showing you the invasion process we're + + align:start position:0% +showing you the invasion process we're + + + align:start position:0% +showing you the invasion process we're +gonna have an embryo here and what I'm + + align:start position:0% +gonna have an embryo here and what I'm + + + align:start position:0% +gonna have an embryo here and what I'm +going to show you is we're looking at + + align:start position:0% +going to show you is we're looking at + + + align:start position:0% +going to show you is we're looking at +the cells that are expressing twist and + + align:start position:0% +the cells that are expressing twist and + + + align:start position:0% +the cells that are expressing twist and +snail and they're on one side of the + + align:start position:0% +snail and they're on one side of the + + + align:start position:0% +snail and they're on one side of the +embryo and I'm going to show you a + + align:start position:0% +embryo and I'm going to show you a + + + align:start position:0% +embryo and I'm going to show you a +section of the embryo that is this + + align:start position:0% +section of the embryo that is this + + + align:start position:0% +section of the embryo that is this +analogous to this okay so when the cells + + align:start position:0% +analogous to this okay so when the cells + + + align:start position:0% +analogous to this okay so when the cells +move inside they're gonna disappear in + + align:start position:0% +move inside they're gonna disappear in + + + align:start position:0% +move inside they're gonna disappear in +this movie okay so when you see like the + + align:start position:0% +this movie okay so when you see like the + + + align:start position:0% +this movie okay so when you see like the +crease in in the embryo that's when the + + align:start position:0% +crease in in the embryo that's when the + + + align:start position:0% +crease in in the embryo that's when the +cells are invading into the middle of + + align:start position:0% +cells are invading into the middle of + + + align:start position:0% +cells are invading into the middle of +the embryo and so the cell outlines are + + align:start position:0% +the embryo and so the cell outlines are + + + align:start position:0% +the embryo and so the cell outlines are +in magenta here + + align:start position:0% +in magenta here + + + align:start position:0% +in magenta here +and what's labeled in green is a type of + + align:start position:0% +and what's labeled in green is a type of + + + align:start position:0% +and what's labeled in green is a type of +motor protein that's involved in the + + align:start position:0% +motor protein that's involved in the + + + align:start position:0% +motor protein that's involved in the +mobility of cells and in this case is + + align:start position:0% +mobility of cells and in this case is + + + align:start position:0% +mobility of cells and in this case is +involved in these cells moving into the + + align:start position:0% +involved in these cells moving into the + + + align:start position:0% +involved in these cells moving into the +interior of the embryo so here you see + + align:start position:0% +interior of the embryo so here you see + + + align:start position:0% +interior of the embryo so here you see +the motor protein appearing and that's + + align:start position:0% +the motor protein appearing and that's + + + align:start position:0% +the motor protein appearing and that's +when these cells are going to dive into + + align:start position:0% +when these cells are going to dive into + + + align:start position:0% +when these cells are going to dive into +the embryo right so it's almost like a + + align:start position:0% +the embryo right so it's almost like a + + + align:start position:0% +the embryo right so it's almost like a +waterfall these cells are like moving + + align:start position:0% +waterfall these cells are like moving + + + align:start position:0% +waterfall these cells are like moving +into the inside of the embryo through + + align:start position:0% +into the inside of the embryo through + + + align:start position:0% +into the inside of the embryo through +this process of imagination and + + align:start position:0% +this process of imagination and + + + align:start position:0% +this process of imagination and +subsequently EMT there it goes again + + align:start position:0% +subsequently EMT there it goes again + + + align:start position:0% +subsequently EMT there it goes again +you can see the cells are now on the + + align:start position:0% +you can see the cells are now on the + + + align:start position:0% +you can see the cells are now on the +inside okay + + align:start position:0% +inside okay + + + align:start position:0% +inside okay +so this process of EMT also involves + + align:start position:0% +so this process of EMT also involves + + + align:start position:0% +so this process of EMT also involves +interactions between the cancer cells + + align:start position:0% +interactions between the cancer cells + + + align:start position:0% +interactions between the cancer cells +and the stroma and that's illustrated + + align:start position:0% +and the stroma and that's illustrated + + + align:start position:0% +and the stroma and that's illustrated +here because what you can see what's + + align:start position:0% +here because what you can see what's + + + align:start position:0% +here because what you can see what's +being labeled here you can see the + + align:start position:0% +being labeled here you can see the + + + align:start position:0% +being labeled here you can see the +nuclei of the cells but these cells at + + align:start position:0% +nuclei of the cells but these cells at + + + align:start position:0% +nuclei of the cells but these cells at +the edge of the tumor are up regulating + + align:start position:0% +the edge of the tumor are up regulating + + + align:start position:0% +the edge of the tumor are up regulating +this gene which is an alpha beta + + align:start position:0% +this gene which is an alpha beta + + + align:start position:0% +this gene which is an alpha beta +integral which I'll mention in just a + + align:start position:0% +integral which I'll mention in just a + + + align:start position:0% +integral which I'll mention in just a +minute and this is getting up regulated + + align:start position:0% +minute and this is getting up regulated + + + align:start position:0% +minute and this is getting up regulated +right where the tumor contacts the + + align:start position:0% +right where the tumor contacts the + + + align:start position:0% +right where the tumor contacts the +stroma and this gene alpha beta + + align:start position:0% +stroma and this gene alpha beta + + + align:start position:0% +stroma and this gene alpha beta +integrand is a gene that's associated + + align:start position:0% +integrand is a gene that's associated + + + align:start position:0% +integrand is a gene that's associated +with motility and EMT so in that slide + + align:start position:0% +with motility and EMT so in that slide + + + align:start position:0% +with motility and EMT so in that slide +here one gene involved in motility + + align:start position:0% +here one gene involved in motility + + + align:start position:0% +here one gene involved in motility +as a class of genes called integrins + + align:start position:0% +as a class of genes called integrins + + + align:start position:0% +as a class of genes called integrins +okay and so this also results from the + + align:start position:0% +okay and so this also results from the + + + align:start position:0% +okay and so this also results from the +signaling between the tumor and the + + align:start position:0% +signaling between the tumor and the + + + align:start position:0% +signaling between the tumor and the +surrounding cells and again this is not + + align:start position:0% +surrounding cells and again this is not + + + align:start position:0% +surrounding cells and again this is not +something that cancer created this is + + align:start position:0% +something that cancer created this is + + + align:start position:0% +something that cancer created this is +what happens during wound healing + + align:start position:0% +what happens during wound healing + + + align:start position:0% +what happens during wound healing +so during wound healing if you injure + + align:start position:0% +so during wound healing if you injure + + + align:start position:0% +so during wound healing if you injure +yourself the the wound recruits immune + + align:start position:0% +yourself the the wound recruits immune + + + align:start position:0% +yourself the the wound recruits immune +cells and the immune cells signal to the + + align:start position:0% +cells and the immune cells signal to the + + + align:start position:0% +cells and the immune cells signal to the +surrounding skin or epithelial cells to + + align:start position:0% +surrounding skin or epithelial cells to + + + align:start position:0% +surrounding skin or epithelial cells to +undergo EMT in order to close and fill + + align:start position:0% +undergo EMT in order to close and fill + + + align:start position:0% +undergo EMT in order to close and fill +in the wound okay so this is a natural + + align:start position:0% +in the wound okay so this is a natural + + + align:start position:0% +in the wound okay so this is a natural +process that happens in your body that + + align:start position:0% +process that happens in your body that + + + align:start position:0% +process that happens in your body that +is simply getting corrupted by cancer + + align:start position:0% +is simply getting corrupted by cancer + + + align:start position:0% +is simply getting corrupted by cancer +cells + + align:start position:0% + + + + align:start position:0% + +all right so now let's talk about this + + align:start position:0% +all right so now let's talk about this + + + align:start position:0% +all right so now let's talk about this +last step of motility so this is now how + + align:start position:0% +last step of motility so this is now how + + + align:start position:0% +last step of motility so this is now how +the cells would break out and move away + + align:start position:0% + + + + align:start position:0% + +alright let's come back to this movie + + align:start position:0% +alright let's come back to this movie + + + align:start position:0% +alright let's come back to this movie +here there are a few things I want you + + align:start position:0% +here there are a few things I want you + + + align:start position:0% +here there are a few things I want you +to notice about this movie the first is + + align:start position:0% +to notice about this movie the first is + + + align:start position:0% +to notice about this movie the first is +holy that cell is moving ok and so + + align:start position:0% +holy that cell is moving ok and so + + + align:start position:0% +holy that cell is moving ok and so +so like the first aspect of this is + + align:start position:0% +so like the first aspect of this is + + + align:start position:0% +so like the first aspect of this is +because the cell is moving it suggests + + align:start position:0% +because the cell is moving it suggests + + + align:start position:0% +because the cell is moving it suggests +that there's some sort of force being + + align:start position:0% +that there's some sort of force being + + + align:start position:0% +that there's some sort of force being +generated okay so there is the cell is + + align:start position:0% +generated okay so there is the cell is + + + align:start position:0% +generated okay so there is the cell is +generating force and I'm not talking + + align:start position:0% +generating force and I'm not talking + + + align:start position:0% +generating force and I'm not talking +about like some type of mystical Jedi + + align:start position:0% +about like some type of mystical Jedi + + + align:start position:0% +about like some type of mystical Jedi +force I'm talking about the mass times + + align:start position:0% +force I'm talking about the mass times + + + align:start position:0% +force I'm talking about the mass times +acceleration force okay so like a + + align:start position:0% +acceleration force okay so like a + + + align:start position:0% +acceleration force okay so like a +physical force okay the second thing I + + align:start position:0% +physical force okay the second thing I + + + align:start position:0% +physical force okay the second thing I +want to point out about this movie is + + align:start position:0% +want to point out about this movie is + + + align:start position:0% +want to point out about this movie is +that you see that bacterium and it's + + align:start position:0% +that you see that bacterium and it's + + + align:start position:0% +that you see that bacterium and it's +moving around this cell is able to + + align:start position:0% +moving around this cell is able to + + + align:start position:0% +moving around this cell is able to +follow that bacterium so the cell and + + align:start position:0% +follow that bacterium so the cell and + + + align:start position:0% +follow that bacterium so the cell and +the fourth generation process is very + + align:start position:0% +the fourth generation process is very + + + align:start position:0% +the fourth generation process is very +responsive to the signals that that cell + + align:start position:0% +responsive to the signals that that cell + + + align:start position:0% +responsive to the signals that that cell +is getting okay so the cell is + + align:start position:0% +is getting okay so the cell is + + + align:start position:0% +is getting okay so the cell is +generating force and this force is + + align:start position:0% +generating force and this force is + + + align:start position:0% +generating force and this force is +responsive to signals + + align:start position:0% + + + + align:start position:0% + +okay so for the remaining part of the + + align:start position:0% +okay so for the remaining part of the + + + align:start position:0% +okay so for the remaining part of the +lecture I basically just want to tell + + align:start position:0% +lecture I basically just want to tell + + + align:start position:0% +lecture I basically just want to tell +you about how it is that the cell + + align:start position:0% +you about how it is that the cell + + + align:start position:0% +you about how it is that the cell +generates the force required to move + + align:start position:0% +generates the force required to move + + + align:start position:0% +generates the force required to move +itself around and it involves a + + align:start position:0% +itself around and it involves a + + + align:start position:0% +itself around and it involves a +particular type of protein it's a + + align:start position:0% +particular type of protein it's a + + + align:start position:0% +particular type of protein it's a +component of the cytoskeleton and we've + + align:start position:0% +component of the cytoskeleton and we've + + + align:start position:0% +component of the cytoskeleton and we've +talked about microtubules and the + + align:start position:0% +talked about microtubules and the + + + align:start position:0% +talked about microtubules and the +microtubule cytoskeleton in its role in + + align:start position:0% +microtubule cytoskeleton in its role in + + + align:start position:0% +microtubule cytoskeleton in its role in +segregating the chromosome but there are + + align:start position:0% +segregating the chromosome but there are + + + align:start position:0% +segregating the chromosome but there are +other cytoskeletal systems that the cell + + align:start position:0% +other cytoskeletal systems that the cell + + + align:start position:0% +other cytoskeletal systems that the cell +has and one is called the actin + + align:start position:0% +has and one is called the actin + + + align:start position:0% +has and one is called the actin +cytoskeleton which is showed on the side + + align:start position:0% +cytoskeleton which is showed on the side + + + align:start position:0% +cytoskeleton which is showed on the side +above and actin the actin cytoskeleton + + align:start position:0% +above and actin the actin cytoskeleton + + + align:start position:0% +above and actin the actin cytoskeleton +is a system that is a biopolymer in the + + align:start position:0% +is a system that is a biopolymer in the + + + align:start position:0% +is a system that is a biopolymer in the +cell so this is a biopolymer like + + align:start position:0% +cell so this is a biopolymer like + + + align:start position:0% +cell so this is a biopolymer like +microtubules and actin is a gene and the + + align:start position:0% +microtubules and actin is a gene and the + + + align:start position:0% +microtubules and actin is a gene and the +actin gene encodes for a protein the + + align:start position:0% +actin gene encodes for a protein the + + + align:start position:0% +actin gene encodes for a protein the +actin protein and when the actin protein + + align:start position:0% +actin protein and when the actin protein + + + align:start position:0% +actin protein and when the actin protein +is made in the cell it start out as + + align:start position:0% +is made in the cell it start out as + + + align:start position:0% +is made in the cell it start out as +being just a sink a single globular + + align:start position:0% +being just a sink a single globular + + + align:start position:0% +being just a sink a single globular +protein okay and when the actin is in + + align:start position:0% +protein okay and when the actin is in + + + align:start position:0% +protein okay and when the actin is in +this state it is called globular or g + + align:start position:0% +this state it is called globular or g + + + align:start position:0% +this state it is called globular or g +actin okay but these subunits these + + align:start position:0% +actin okay but these subunits these + + + align:start position:0% +actin okay but these subunits these +proteins can come together and form a + + align:start position:0% +proteins can come together and form a + + + align:start position:0% +proteins can come together and form a +polymer so they can go from being + + align:start position:0% +polymer so they can go from being + + + align:start position:0% +polymer so they can go from being +individual isolated proteins to forming + + align:start position:0% +individual isolated proteins to forming + + + align:start position:0% +individual isolated proteins to forming +a polymer that forms a long skinny + + align:start position:0% +a polymer that forms a long skinny + + + align:start position:0% +a polymer that forms a long skinny +filament okay and the this form of the + + align:start position:0% +filament okay and the this form of the + + + align:start position:0% +filament okay and the this form of the +protein that's forming a biopolymer is + + align:start position:0% +protein that's forming a biopolymer is + + + align:start position:0% +protein that's forming a biopolymer is +known as filamentous or f-actin + + align:start position:0% + + + + align:start position:0% + +okay and these are long skinny filaments + + align:start position:0% +okay and these are long skinny filaments + + + align:start position:0% +okay and these are long skinny filaments +they can be hundreds of nanometers even + + align:start position:0% +they can be hundreds of nanometers even + + + align:start position:0% +they can be hundreds of nanometers even +microns in length so hundreds of + + align:start position:0% +microns in length so hundreds of + + + align:start position:0% +microns in length so hundreds of +nanometers long and the filament width + + align:start position:0% +nanometers long and the filament width + + + align:start position:0% +nanometers long and the filament width +is about 10 nanometers okay so I'm just + + align:start position:0% +is about 10 nanometers okay so I'm just + + + align:start position:0% +is about 10 nanometers okay so I'm just +trying to give you a sense of dimensions + + align:start position:0% +trying to give you a sense of dimensions + + + align:start position:0% +trying to give you a sense of dimensions +that this is a long skinny filament that + + align:start position:0% +that this is a long skinny filament that + + + align:start position:0% +that this is a long skinny filament that +the cell can assemble and it assembles + + align:start position:0% +the cell can assemble and it assembles + + + align:start position:0% +the cell can assemble and it assembles +into these dense mesh works which you + + align:start position:0% +into these dense mesh works which you + + + align:start position:0% +into these dense mesh works which you +can see in the slide up here right so + + align:start position:0% +can see in the slide up here right so + + + align:start position:0% +can see in the slide up here right so +this is the leading edge of the cell so + + align:start position:0% +this is the leading edge of the cell so + + + align:start position:0% +this is the leading edge of the cell so +the cell will be migrating this way and + + align:start position:0% +the cell will be migrating this way and + + + align:start position:0% +the cell will be migrating this way and +what you see in this in this cell is + + align:start position:0% +what you see in this in this cell is + + + align:start position:0% +what you see in this in this cell is +this densely branched network and these + + align:start position:0% +this densely branched network and these + + + align:start position:0% +this densely branched network and these +are all actin filaments okay so you get + + align:start position:0% +are all actin filaments okay so you get + + + align:start position:0% +are all actin filaments okay so you get +this huge dense forest of actin + + align:start position:0% +this huge dense forest of actin + + + align:start position:0% +this huge dense forest of actin +filaments that's right at the edge of + + align:start position:0% +filaments that's right at the edge of + + + align:start position:0% +filaments that's right at the edge of +the cell that is moving forward okay one + + align:start position:0% +the cell that is moving forward okay one + + + align:start position:0% +the cell that is moving forward okay one +thing I want to point out is like all + + align:start position:0% +thing I want to point out is like all + + + align:start position:0% +thing I want to point out is like all +things in biology this is not a one-way + + align:start position:0% +things in biology this is not a one-way + + + align:start position:0% +things in biology this is not a one-way +street + + align:start position:0% +street + + + align:start position:0% +street +and so these bio polymers are very + + align:start position:0% +and so these bio polymers are very + + + align:start position:0% +and so these bio polymers are very +dynamic meaning they can undergo + + align:start position:0% +dynamic meaning they can undergo + + + align:start position:0% +dynamic meaning they can undergo +assembly and disassembly and they can do + + align:start position:0% +assembly and disassembly and they can do + + + align:start position:0% +assembly and disassembly and they can do +so on the timescale of seconds one last + + align:start position:0% +so on the timescale of seconds one last + + + align:start position:0% +so on the timescale of seconds one last +thing I want to point out about the + + align:start position:0% +thing I want to point out about the + + + align:start position:0% +thing I want to point out about the +actin filament is there's a polarity to + + align:start position:0% +actin filament is there's a polarity to + + + align:start position:0% +actin filament is there's a polarity to +the filament such that there's a end + + align:start position:0% +the filament such that there's a end + + + align:start position:0% +the filament such that there's a end +known as the plus end where growth is + + align:start position:0% +known as the plus end where growth is + + + align:start position:0% +known as the plus end where growth is +favored and there's an end known as the + + align:start position:0% +favored and there's an end known as the + + + align:start position:0% +favored and there's an end known as the +minus end where there's often d + + align:start position:0% +minus end where there's often d + + + align:start position:0% +minus end where there's often d +polymerization so you can get a + + align:start position:0% +polymerization so you can get a + + + align:start position:0% +polymerization so you can get a +directional growth of the filament so + + align:start position:0% +directional growth of the filament so + + + align:start position:0% +directional growth of the filament so +this is where growth happens and so in + + align:start position:0% +this is where growth happens and so in + + + align:start position:0% +this is where growth happens and so in +this network that you're looking at the + + align:start position:0% +this network that you're looking at the + + + align:start position:0% +this network that you're looking at the +way that actin is oriented so I'm going + + align:start position:0% +way that actin is oriented so I'm going + + + align:start position:0% +way that actin is oriented so I'm going +to draw just a cell here you have this + + align:start position:0% +to draw just a cell here you have this + + + align:start position:0% +to draw just a cell here you have this +dense meshwork of actin and in this + + align:start position:0% +dense meshwork of actin and in this + + + align:start position:0% +dense meshwork of actin and in this +meshwork there's a polarity to the way + + align:start position:0% +meshwork there's a polarity to the way + + + align:start position:0% +meshwork there's a polarity to the way +the actin filaments are oriented so the + + align:start position:0% +the actin filaments are oriented so the + + + align:start position:0% +the actin filaments are oriented so the +cell is migrating this way and the plus + + align:start position:0% +cell is migrating this way and the plus + + + align:start position:0% +cell is migrating this way and the plus +ends of the actin filaments are facing + + align:start position:0% +ends of the actin filaments are facing + + + align:start position:0% +ends of the actin filaments are facing +out right at the surface and the minus + + align:start position:0% +out right at the surface and the minus + + + align:start position:0% +out right at the surface and the minus +ends are back here + + align:start position:0% +ends are back here + + + align:start position:0% +ends are back here +okay and so what you have when the cell + + align:start position:0% +okay and so what you have when the cell + + + align:start position:0% +okay and so what you have when the cell +is migrating is you have this biopolymer + + align:start position:0% +is migrating is you have this biopolymer + + + align:start position:0% +is migrating is you have this biopolymer +Network that's growing on this end but + + align:start position:0% +Network that's growing on this end but + + + align:start position:0% +Network that's growing on this end but +shrinking on the other end and that + + align:start position:0% +shrinking on the other end and that + + + align:start position:0% +shrinking on the other end and that +allows the cell to generate a constant + + align:start position:0% +allows the cell to generate a constant + + + align:start position:0% +allows the cell to generate a constant +per true civ force okay so it's the + + align:start position:0% +per true civ force okay so it's the + + + align:start position:0% +per true civ force okay so it's the +growth of actin filaments the growth of + + align:start position:0% +growth of actin filaments the growth of + + + align:start position:0% +growth of actin filaments the growth of +of f-actin which generates a protrusion + + align:start position:0% + + + + align:start position:0% + +no if we consider the whole process of + + align:start position:0% +no if we consider the whole process of + + + align:start position:0% +no if we consider the whole process of +cell migration what you can see is that + + align:start position:0% +cell migration what you can see is that + + + align:start position:0% +cell migration what you can see is that +initially you're gonna push the cell + + align:start position:0% +initially you're gonna push the cell + + + align:start position:0% +initially you're gonna push the cell +membrane forward okay so you get a + + align:start position:0% +membrane forward okay so you get a + + + align:start position:0% +membrane forward okay so you get a +protrusion it pushes it forward that's + + align:start position:0% +protrusion it pushes it forward that's + + + align:start position:0% +protrusion it pushes it forward that's +often called a lamellipodia + + align:start position:0% +often called a lamellipodia + + + align:start position:0% +often called a lamellipodia +or a pseudo pod and so this sort of part + + align:start position:0% +or a pseudo pod and so this sort of part + + + align:start position:0% +or a pseudo pod and so this sort of part +of the cell moves forward but in order + + align:start position:0% +of the cell moves forward but in order + + + align:start position:0% +of the cell moves forward but in order +for the cell to have a net motion + + align:start position:0% +for the cell to have a net motion + + + align:start position:0% +for the cell to have a net motion +forward it then has to stabilize that + + align:start position:0% +forward it then has to stabilize that + + + align:start position:0% +forward it then has to stabilize that +protrusion and it stabilizes the + + align:start position:0% +protrusion and it stabilizes the + + + align:start position:0% +protrusion and it stabilizes the +protrusion by adhering to the substrate + + align:start position:0% +protrusion by adhering to the substrate + + + align:start position:0% +protrusion by adhering to the substrate +so right now we're just considering a + + align:start position:0% +so right now we're just considering a + + + align:start position:0% +so right now we're just considering a +cell moving on a flat substrate and so + + align:start position:0% +cell moving on a flat substrate and so + + + align:start position:0% +cell moving on a flat substrate and so +the way it attaches to the substrate is + + align:start position:0% +the way it attaches to the substrate is + + + align:start position:0% +the way it attaches to the substrate is +through cell matrix adhesion and this + + align:start position:0% +through cell matrix adhesion and this + + + align:start position:0% +through cell matrix adhesion and this +cell matrix adhesion is mediated by + + align:start position:0% +cell matrix adhesion is mediated by + + + align:start position:0% +cell matrix adhesion is mediated by +another type of adhesion receptor known + + align:start position:0% +another type of adhesion receptor known + + + align:start position:0% +another type of adhesion receptor known +as an integral okay so the cell pushes + + align:start position:0% +as an integral okay so the cell pushes + + + align:start position:0% +as an integral okay so the cell pushes +forward anchors itself + + align:start position:0% +forward anchors itself + + + align:start position:0% +forward anchors itself +on the substrate pulls its body along + + align:start position:0% +on the substrate pulls its body along + + + align:start position:0% +on the substrate pulls its body along +and then just repeats that cycle over + + align:start position:0% +and then just repeats that cycle over + + + align:start position:0% +and then just repeats that cycle over +and over again so the the best way I can + + align:start position:0% +and over again so the the best way I can + + + align:start position:0% +and over again so the the best way I can +illustrate this is if you think about it + + align:start position:0% +illustrate this is if you think about it + + + align:start position:0% +illustrate this is if you think about it +right you get your protrusion you get + + align:start position:0% +right you get your protrusion you get + + + align:start position:0% +right you get your protrusion you get +your elbow out you put down you anchor + + align:start position:0% +your elbow out you put down you anchor + + + align:start position:0% +your elbow out you put down you anchor +right and it's just a repeated cycle and + + align:start position:0% +right and it's just a repeated cycle and + + + align:start position:0% +right and it's just a repeated cycle and +it's able to migrate across the + + align:start position:0% +it's able to migrate across the + + + align:start position:0% +it's able to migrate across the +substrate + + align:start position:0% +substrate + + + align:start position:0% +substrate +so it's kind of like a frontal tow + + align:start position:0% +so it's kind of like a frontal tow + + + align:start position:0% +so it's kind of like a frontal tow +mechanism okay you have cycles of + + align:start position:0% +mechanism okay you have cycles of + + + align:start position:0% +mechanism okay you have cycles of +protrusion you generate traction and + + align:start position:0% +protrusion you generate traction and + + + align:start position:0% +protrusion you generate traction and +then you pull in order to translocate + + align:start position:0% +then you pull in order to translocate + + + align:start position:0% +then you pull in order to translocate +okay and so that's how cells are + + align:start position:0% +okay and so that's how cells are + + + align:start position:0% +okay and so that's how cells are +migrating and in 2d oh this is just + + align:start position:0% +migrating and in 2d oh this is just + + + align:start position:0% +migrating and in 2d oh this is just +showing you that cells can pull on stuff + + align:start position:0% +showing you that cells can pull on stuff + + + align:start position:0% +showing you that cells can pull on stuff +so this not all cells migrate in this + + align:start position:0% +so this not all cells migrate in this + + + align:start position:0% +so this not all cells migrate in this +way I just wanted to say that + + align:start position:0% +way I just wanted to say that + + + align:start position:0% +way I just wanted to say that +so in 3d cells have other mechanisms to + + align:start position:0% +so in 3d cells have other mechanisms to + + + align:start position:0% +so in 3d cells have other mechanisms to +migrate that de-emphasize this traction + + align:start position:0% +migrate that de-emphasize this traction + + + align:start position:0% +migrate that de-emphasize this traction +mechanism that cells have okay so you + + align:start position:0% +mechanism that cells have okay so you + + + align:start position:0% +mechanism that cells have okay so you +can get rid of all the integrins that a + + align:start position:0% +can get rid of all the integrins that a + + + align:start position:0% +can get rid of all the integrins that a +cell has and they're still able to + + align:start position:0% +cell has and they're still able to + + + align:start position:0% +cell has and they're still able to +migrate and that's because 2d emphasizes + + align:start position:0% +migrate and that's because 2d emphasizes + + + align:start position:0% +migrate and that's because 2d emphasizes +the role of adhesion but if you confine + + align:start position:0% +the role of adhesion but if you confine + + + align:start position:0% +the role of adhesion but if you confine +the cell then the cells are able to + + align:start position:0% +the cell then the cells are able to + + + align:start position:0% +the cell then the cells are able to +migrate + + align:start position:0% +migrate + + + align:start position:0% +migrate +so what's shown here are cells that are + + align:start position:0% +so what's shown here are cells that are + + + align:start position:0% +so what's shown here are cells that are +not confined this is a confined cell in + + align:start position:0% +not confined this is a confined cell in + + + align:start position:0% +not confined this is a confined cell in +a micropipette and you can see it's the + + align:start position:0% +a micropipette and you can see it's the + + + align:start position:0% +a micropipette and you can see it's the +same type of cell but the cell can + + align:start position:0% +same type of cell but the cell can + + + align:start position:0% +same type of cell but the cell can +migrate in confinement but it can't + + align:start position:0% +migrate in confinement but it can't + + + align:start position:0% +migrate in confinement but it can't +migrate outside of confinement okay so + + align:start position:0% +migrate outside of confinement okay so + + + align:start position:0% +migrate outside of confinement okay so +in this sense the cell is migrating + + align:start position:0% +in this sense the cell is migrating + + + align:start position:0% +in this sense the cell is migrating +through a different mode and you can + + align:start position:0% +through a different mode and you can + + + align:start position:0% +through a different mode and you can +kind of thinking it you can think of it + + align:start position:0% +kind of thinking it you can think of it + + + align:start position:0% +kind of thinking it you can think of it +as the cells doing some type of Chimney + + align:start position:0% +as the cells doing some type of Chimney + + + align:start position:0% +as the cells doing some type of Chimney +maneuver so it's able to kind of like + + align:start position:0% +maneuver so it's able to kind of like + + + align:start position:0% +maneuver so it's able to kind of like +get in a confined environment push out + + align:start position:0% +get in a confined environment push out + + + align:start position:0% +get in a confined environment push out +against its surroundings and that's how + + align:start position:0% +against its surroundings and that's how + + + align:start position:0% +against its surroundings and that's how +the cell then is able to generate + + align:start position:0% +the cell then is able to generate + + + align:start position:0% +the cell then is able to generate +traction in the absence of an integral + + align:start position:0% +traction in the absence of an integral + + + align:start position:0% +traction in the absence of an integral +molecule + + align:start position:0% +molecule + + + align:start position:0% +molecule +all right great so we are set for now + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/6wPHoFjnYXI.txt b/6wPHoFjnYXI.txt new file mode 100644 index 0000000000000000000000000000000000000000..13d75d00dc67e39ae1ad19d9c880165c16ccc6b7 --- /dev/null +++ b/6wPHoFjnYXI.txt @@ -0,0 +1,5099 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right thoughts important + + align:start position:0% +ocw.mit.edu all right thoughts important + + + align:start position:0% +ocw.mit.edu all right thoughts important +Concepts through the week principal AES + + align:start position:0% +Concepts through the week principal AES + + + align:start position:0% +Concepts through the week principal AES +principal + + align:start position:0% + + + + align:start position:0% + +AES + + align:start position:0% + + + + align:start position:0% + +another one Dynamic versus static + + align:start position:0% +another one Dynamic versus static + + + align:start position:0% +another one Dynamic versus static +balances + + align:start position:0% + + + + align:start position:0% + +right another one + + align:start position:0% +right another one + + + align:start position:0% +right another one +symetry symmetry + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +this is in the context of things like + + align:start position:0% +this is in the context of things like + + + align:start position:0% +this is in the context of things like +the mass moment of inertia Matrix yes + + align:start position:0% +the mass moment of inertia Matrix yes + + + align:start position:0% +the mass moment of inertia Matrix yes +parallel AIS the parallel AIS theem okay + + align:start position:0% +parallel AIS the parallel AIS theem okay + + + align:start position:0% +parallel AIS the parallel AIS theem okay +we haven't done much with it yet but + + align:start position:0% +we haven't done much with it yet but + + + align:start position:0% +we haven't done much with it yet but +we're going to come back to + + align:start position:0% + + + + align:start position:0% + +it all + + align:start position:0% +it all + + + align:start position:0% +it all +right all right pretty good list we only + + align:start position:0% +right all right pretty good list we only + + + align:start position:0% +right all right pretty good list we only +had one + + align:start position:0% +had one + + + align:start position:0% +had one +lecture + + align:start position:0% + + + + align:start position:0% + +Dynamic and static balancing let's talk + + align:start position:0% +Dynamic and static balancing let's talk + + + align:start position:0% +Dynamic and static balancing let's talk +about that for a second + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +if let's talk about static balancing + + align:start position:0% +if let's talk about static balancing + + + align:start position:0% +if let's talk about static balancing +tell me what's are features of static + + align:start position:0% +tell me what's are features of static + + + align:start position:0% +tell me what's are features of static +balancing how can you you have a quiz + + align:start position:0% +balancing how can you you have a quiz + + + align:start position:0% +balancing how can you you have a quiz +problem it's on the final you have an + + align:start position:0% +problem it's on the final you have an + + + align:start position:0% +problem it's on the final you have an +object and an axis about which it's + + align:start position:0% +object and an axis about which it's + + + align:start position:0% +object and an axis about which it's +spinning and you're act asked is this + + align:start position:0% +spinning and you're act asked is this + + + align:start position:0% +spinning and you're act asked is this +statically balanced or not + + align:start position:0% +statically balanced or not + + + align:start position:0% +statically balanced or not +how what would you look for Christina + + align:start position:0% +how what would you look for Christina + + + align:start position:0% +how what would you look for Christina +g g needs to be the ceris so the another + + align:start position:0% +g g needs to be the ceris so the another + + + align:start position:0% +g g needs to be the ceris so the another +way of saying that is the axis must the + + align:start position:0% +way of saying that is the axis must the + + + align:start position:0% +way of saying that is the axis must the +axis of rotation must pass through G is + + align:start position:0% +axis of rotation must pass through G is + + + align:start position:0% +axis of rotation must pass through G is +that what you're trying to say the + + align:start position:0% +that what you're trying to say the + + + align:start position:0% +that what you're trying to say the +center of mass okay everybody agree + + align:start position:0% +center of mass okay everybody agree + + + align:start position:0% +center of mass okay everybody agree +about that all right now if I + + align:start position:0% +about that all right now if I + + + align:start position:0% +about that all right now if I +have weird shaped object I know where + + align:start position:0% +have weird shaped object I know where + + + align:start position:0% +have weird shaped object I know where +the center of mass is and I stick the + + align:start position:0% +the center of mass is and I stick the + + + align:start position:0% +the center of mass is and I stick the +axis of rotation at any angle it all + + align:start position:0% +axis of rotation at any angle it all + + + align:start position:0% +axis of rotation at any angle it all +through + + align:start position:0% +through + + + align:start position:0% +through +it is it statically balanced regardless + + align:start position:0% +it is it statically balanced regardless + + + align:start position:0% +it is it statically balanced regardless +of the where I have the axis of rotation + + align:start position:0% +of the where I have the axis of rotation + + + align:start position:0% +of the where I have the axis of rotation +passing through the center of mass yes I + + align:start position:0% +passing through the center of mass yes I + + + align:start position:0% +passing through the center of mass yes I +hear a yes how about there other people + + align:start position:0% +hear a yes how about there other people + + + align:start position:0% +hear a yes how about there other people +okay so how do you I think that's + + align:start position:0% +okay so how do you I think that's + + + align:start position:0% +okay so how do you I think that's +probably right but how do you test it + + align:start position:0% +probably right but how do you test it + + + align:start position:0% +probably right but how do you test it +how do you test to see how it's a simple + + align:start position:0% +how do you test to see how it's a simple + + + align:start position:0% +how do you test to see how it's a simple +test you can form to see if something is + + align:start position:0% +test you can form to see if something is + + + align:start position:0% +test you can form to see if something is +statically balanced see if it goes to a + + align:start position:0% +statically balanced see if it goes to a + + + align:start position:0% +statically balanced see if it goes to a +low point right so you make the axis + + align:start position:0% +low point right so you make the axis + + + align:start position:0% +low point right so you make the axis +that you're rotating about + + align:start position:0% +that you're rotating about + + + align:start position:0% +that you're rotating about +horizontal and see if the thing seeks a + + align:start position:0% +horizontal and see if the thing seeks a + + + align:start position:0% +horizontal and see if the thing seeks a +low point because if it does it's + + align:start position:0% +low point because if it does it's + + + align:start position:0% +low point because if it does it's +telling you + + align:start position:0% +telling you + + + align:start position:0% +telling you +that what about the center of mass it's + + align:start position:0% +that what about the center of mass it's + + + align:start position:0% +that what about the center of mass it's +not going he's not going through the + + align:start position:0% +not going he's not going through the + + + align:start position:0% +not going he's not going through the +axis to go to a low point it means the + + align:start position:0% +axis to go to a low point it means the + + + align:start position:0% +axis to go to a low point it means the +center of mass is somewhere below that + + align:start position:0% +center of mass is somewhere below that + + + align:start position:0% +center of mass is somewhere below that +axis has beenin right so but any axis at + + align:start position:0% +axis has beenin right so but any axis at + + + align:start position:0% +axis has beenin right so but any axis at +all long as it's through G you are + + align:start position:0% +all long as it's through G you are + + + align:start position:0% +all long as it's through G you are +statically balanced okay Dynamic + + align:start position:0% +statically balanced okay Dynamic + + + align:start position:0% +statically balanced okay Dynamic +balancing what are the what's what would + + align:start position:0% +balancing what are the what's what would + + + align:start position:0% +balancing what are the what's what would +you look for on an object you said is + + align:start position:0% +you look for on an object you said is + + + align:start position:0% +you look for on an object you said is +this dynamic Al balanced or not what + + align:start position:0% +this dynamic Al balanced or not what + + + align:start position:0% +this dynamic Al balanced or not what +kind of + + align:start position:0% + + + + align:start position:0% + +properties there would be no unbalanced + + align:start position:0% +properties there would be no unbalanced + + + align:start position:0% +properties there would be no unbalanced +torqus if you decided to rotate it okay + + align:start position:0% +torqus if you decided to rotate it okay + + + align:start position:0% +torqus if you decided to rotate it okay +so you're looking for no unbalanced + + align:start position:0% +so you're looking for no unbalanced + + + align:start position:0% +so you're looking for no unbalanced +torqus doesn't like if if the object is + + align:start position:0% +torqus doesn't like if if the object is + + + align:start position:0% +torqus doesn't like if if the object is +rotating about the axis that you have it + + align:start position:0% +rotating about the axis that you have it + + + align:start position:0% +rotating about the axis that you have it +on you won't need to supply an extra + + align:start position:0% +on you won't need to supply an extra + + + align:start position:0% +on you won't need to supply an extra +torque + + align:start position:0% + + + + align:start position:0% + +to want to keep it Balan okay I I it's + + align:start position:0% +to want to keep it Balan okay I I it's + + + align:start position:0% +to want to keep it Balan okay I I it's +pretty convincing off the AIS it's + + align:start position:0% +pretty convincing off the AIS it's + + + align:start position:0% +pretty convincing off the AIS it's +rotating okay but you put in that last + + align:start position:0% +rotating okay but you put in that last + + + align:start position:0% +rotating okay but you put in that last +caveat then it's about then it's getting + + align:start position:0% +caveat then it's about then it's getting + + + align:start position:0% +caveat then it's about then it's getting +pretty correct can there be a torque on + + align:start position:0% +pretty correct can there be a torque on + + + align:start position:0% +pretty correct can there be a torque on +it that's not balanced and have it be + + align:start position:0% +it that's not balanced and have it be + + + align:start position:0% +it that's not balanced and have it be +dynamically balanced well yeah which + + align:start position:0% + + + + align:start position:0% + +one you have a torque that's in the axis + + align:start position:0% +one you have a torque that's in the axis + + + align:start position:0% +one you have a torque that's in the axis +of Spin and around the axis of rotation + + align:start position:0% +of Spin and around the axis of rotation + + + align:start position:0% +of Spin and around the axis of rotation +and that torque will cause what to + + align:start position:0% +and that torque will cause what to + + + align:start position:0% +and that torque will cause what to +happen cause the rot rate to change + + align:start position:0% +happen cause the rot rate to change + + + align:start position:0% +happen cause the rot rate to change +right that that puts energy into the + + align:start position:0% +right that that puts energy into the + + + align:start position:0% +right that that puts energy into the +system and accelerates it and it's a + + align:start position:0% +system and accelerates it and it's a + + + align:start position:0% +system and accelerates it and it's a +torque that's in the direction of spin + + align:start position:0% +torque that's in the direction of spin + + + align:start position:0% +torque that's in the direction of spin +that doesn't cause Dynamic imbalances + + align:start position:0% +that doesn't cause Dynamic imbalances + + + align:start position:0% +that doesn't cause Dynamic imbalances +but a torque that is other than in the + + align:start position:0% +but a torque that is other than in the + + + align:start position:0% +but a torque that is other than in the +direction of + + align:start position:0% +direction of + + + align:start position:0% +direction of +spin that's what that's what a dynamic + + align:start position:0% +spin that's what that's what a dynamic + + + align:start position:0% +spin that's what that's what a dynamic +imbalance is so what are some other ways + + align:start position:0% +imbalance is so what are some other ways + + + align:start position:0% +imbalance is so what are some other ways +you can say this in terms of uh things + + align:start position:0% +you can say this in terms of uh things + + + align:start position:0% +you can say this in terms of uh things +like evidence of if let's say I give you + + align:start position:0% +like evidence of if let's say I give you + + + align:start position:0% +like evidence of if let's say I give you +H and I give you Omega + + align:start position:0% +H and I give you Omega + + + align:start position:0% +H and I give you Omega +how can you just tell by looking at + + align:start position:0% +how can you just tell by looking at + + + align:start position:0% +how can you just tell by looking at +those two things I give you the angular + + align:start position:0% +those two things I give you the angular + + + align:start position:0% +those two things I give you the angular +momentum and I give you this bin how can + + align:start position:0% +momentum and I give you this bin how can + + + align:start position:0% +momentum and I give you this bin how can +you tell instantly whether or not it is + + align:start position:0% +you tell instantly whether or not it is + + + align:start position:0% +you tell instantly whether or not it is +dynamically + + align:start position:0% +dynamically + + + align:start position:0% +dynamically +balanced the components in the same dire + + align:start position:0% +balanced the components in the same dire + + + align:start position:0% +balanced the components in the same dire +so if you're saying if H and Omega are + + align:start position:0% +so if you're saying if H and Omega are + + + align:start position:0% +so if you're saying if H and Omega are +in + + align:start position:0% +in + + + align:start position:0% +in +the our align they just have to be + + align:start position:0% +the our align they just have to be + + + align:start position:0% +the our align they just have to be +parallel if they're aligned you do not + + align:start position:0% +parallel if they're aligned you do not + + + align:start position:0% +parallel if they're aligned you do not +have any Dynamic + + align:start position:0% + + + + align:start position:0% + +imbalance okay that sound right yeah + + align:start position:0% +imbalance okay that sound right yeah + + + align:start position:0% +imbalance okay that sound right yeah +doesn't matter if they're parallel or + + align:start position:0% +doesn't matter if they're parallel or + + + align:start position:0% +doesn't matter if they're parallel or +anti- parallel does it anti mean just + + align:start position:0% +anti- parallel does it anti mean just + + + align:start position:0% +anti- parallel does it anti mean just +opposite senses uh I think that would be + + align:start position:0% +opposite senses uh I think that would be + + + align:start position:0% +opposite senses uh I think that would be +really hard to do I don't know if any I + + align:start position:0% +really hard to do I don't know if any I + + + align:start position:0% +really hard to do I don't know if any I +don't think you can I don't think you + + align:start position:0% +don't think you can I don't think you + + + align:start position:0% +don't think you can I don't think you +can make a system that has angular + + align:start position:0% +can make a system that has angular + + + align:start position:0% +can make a system that has angular +momentum that is negative it's actually + + align:start position:0% +momentum that is negative it's actually + + + align:start position:0% +momentum that is negative it's actually +opposite the direction of the rotation + + align:start position:0% +opposite the direction of the rotation + + + align:start position:0% +opposite the direction of the rotation +rate I don't think it I don't think our + + align:start position:0% +rate I don't think it I don't think our + + + align:start position:0% +rate I don't think it I don't think our +universe supports that physics but + + align:start position:0% +universe supports that physics but + + + align:start position:0% +universe supports that physics but +anyway I think in any case they're + + align:start position:0% +anyway I think in any case they're + + + align:start position:0% +anyway I think in any case they're +aligned you're okay + + align:start position:0% + + + + align:start position:0% + +okay all right let's move on so + + align:start position:0% +okay all right let's move on so + + + align:start position:0% +okay all right let's move on so +um today we're going to actually just + + align:start position:0% +um today we're going to actually just + + + align:start position:0% +um today we're going to actually just +have you work a couple problems and you + + align:start position:0% +have you work a couple problems and you + + + align:start position:0% +have you work a couple problems and you +really are going to work in groups and + + align:start position:0% +really are going to work in groups and + + + align:start position:0% +really are going to work in groups and +when you finish one of the groups is + + align:start position:0% +when you finish one of the groups is + + + align:start position:0% +when you finish one of the groups is +going to come up and fill in the blanks + + align:start position:0% +going to come up and fill in the blanks + + + align:start position:0% +going to come up and fill in the blanks +on the of the answer to the problem and + + align:start position:0% +on the of the answer to the problem and + + + align:start position:0% +on the of the answer to the problem and +we'll talk about it and we're going to + + align:start position:0% +we'll talk about it and we're going to + + + align:start position:0% +we'll talk about it and we're going to +work two problems and they have to do + + align:start position:0% +work two problems and they have to do + + + align:start position:0% +work two problems and they have to do +with things that + + align:start position:0% +with things that + + + align:start position:0% +with things that +spin and as a quick + + align:start position:0% +spin and as a quick + + + align:start position:0% +spin and as a quick +review just of information + + align:start position:0% + + + + align:start position:0% + +so we can do + + align:start position:0% + + + + align:start position:0% + +this so the + + align:start position:0% +this so the + + + align:start position:0% +this so the +problem is a simple one it's basically + + align:start position:0% +problem is a simple one it's basically + + + align:start position:0% +problem is a simple one it's basically +this and I decided to lubricate it and I + + align:start position:0% +this and I decided to lubricate it and I + + + align:start position:0% +this and I decided to lubricate it and I +and it made the wood swell and so now it + + align:start position:0% +and it made the wood swell and so now it + + + align:start position:0% +and it made the wood swell and so now it +won't spin at all actually unless I let + + align:start position:0% +won't spin at all actually unless I let + + + align:start position:0% +won't spin at all actually unless I let +the axis spin so it's just this + + align:start position:0% + + + + align:start position:0% + +problem the axis passes through the + + align:start position:0% +problem the axis passes through the + + + align:start position:0% +problem the axis passes through the +center of mass + + align:start position:0% +center of mass + + + align:start position:0% +center of mass +and it looks just like this and I've got + + align:start position:0% +and it looks just like this and I've got + + + align:start position:0% +and it looks just like this and I've got +an X axis aligned with the axis of the + + align:start position:0% +an X axis aligned with the axis of the + + + align:start position:0% +an X axis aligned with the axis of the +rod the Z is this way and the spin is + + align:start position:0% +rod the Z is this way and the spin is + + + align:start position:0% +rod the Z is this way and the spin is +Cap Omega and the uh iner the mass + + align:start position:0% +Cap Omega and the uh iner the mass + + + align:start position:0% +Cap Omega and the uh iner the mass +moment of inertia Matrix for this + + align:start position:0% +moment of inertia Matrix for this + + + align:start position:0% +moment of inertia Matrix for this +problem about G and our axis is passing + + align:start position:0% +problem about G and our axis is passing + + + align:start position:0% +problem about G and our axis is passing +through G so Mass moment of inertia + + align:start position:0% +through G so Mass moment of inertia + + + align:start position:0% +through G so Mass moment of inertia +Matrix times Omega gives you H so here's + + align:start position:0% +Matrix times Omega gives you H so here's + + + align:start position:0% +Matrix times Omega gives you H so here's +the mass moment of inertia Matrix + + align:start position:0% +the mass moment of inertia Matrix + + + align:start position:0% +the mass moment of inertia Matrix +I claim is going to be + + align:start position:0% +I claim is going to be + + + align:start position:0% +I claim is going to be +diagonal and the test of that can you + + align:start position:0% +diagonal and the test of that can you + + + align:start position:0% +diagonal and the test of that can you +tell me whether or not I've chosen axes + + align:start position:0% +tell me whether or not I've chosen axes + + + align:start position:0% +tell me whether or not I've chosen axes +that just from symmetry you know are + + align:start position:0% +that just from symmetry you know are + + + align:start position:0% +that just from symmetry you know are +will be principal + + align:start position:0% + + + + align:start position:0% + +axis what do you + + align:start position:0% +axis what do you + + + align:start position:0% +axis what do you +think cular yeah so one axis that's an + + align:start position:0% +think cular yeah so one axis that's an + + + align:start position:0% +think cular yeah so one axis that's an +axis of symmetry is down the down the + + align:start position:0% +axis of symmetry is down the down the + + + align:start position:0% +axis of symmetry is down the down the +shaft so that's guaranteed to be one if + + align:start position:0% +shaft so that's guaranteed to be one if + + + align:start position:0% +shaft so that's guaranteed to be one if +I chosen one like that and any other + + align:start position:0% +I chosen one like that and any other + + + align:start position:0% +I chosen one like that and any other +orthogonal pair after that doesn't + + align:start position:0% +orthogonal pair after that doesn't + + + align:start position:0% +orthogonal pair after that doesn't +matter which way or Orient them will'll + + align:start position:0% +matter which way or Orient them will'll + + + align:start position:0% +matter which way or Orient them will'll +also be so I've got one up and one into + + align:start position:0% +also be so I've got one up and one into + + + align:start position:0% +also be so I've got one up and one into +the board so those are principal axes + + align:start position:0% +the board so those are principal axes + + + align:start position:0% +the board so those are principal axes +for this object so it's going to be + + align:start position:0% +for this object so it's going to be + + + align:start position:0% +for this object so it's going to be +diagonal and in fact it looks it's uh Mr + + align:start position:0% +diagonal and in fact it looks it's uh Mr + + + align:start position:0% +diagonal and in fact it looks it's uh Mr +2 over 2 ml2 over 12 and ml2 over 12 + + align:start position:0% +2 over 2 ml2 over 12 and ml2 over 12 + + + align:start position:0% +2 over 2 ml2 over 12 and ml2 over 12 +when you work it out and if you look up + + align:start position:0% +when you work it out and if you look up + + + align:start position:0% +when you work it out and if you look up +in the book most books for SL what they + + align:start position:0% +in the book most books for SL what they + + + align:start position:0% +in the book most books for SL what they +call slender rods will say that this + + align:start position:0% +call slender rods will say that this + + + align:start position:0% +call slender rods will say that this +first term is zero and that's because + + align:start position:0% +first term is zero and that's because + + + align:start position:0% +first term is zero and that's because +saying L is a lot bigger than R the + + align:start position:0% +saying L is a lot bigger than R the + + + align:start position:0% +saying L is a lot bigger than R the +radius of this thing and so Mr r s is a + + align:start position:0% +radius of this thing and so Mr r s is a + + + align:start position:0% +radius of this thing and so Mr r s is a +pretty small number so it's its energy + + align:start position:0% +pretty small number so it's its energy + + + align:start position:0% +pretty small number so it's its energy +and + + align:start position:0% +and + + + align:start position:0% +and +rotation spinning this way is not very + + align:start position:0% +rotation spinning this way is not very + + + align:start position:0% +rotation spinning this way is not very +big or its angular momentum but its + + align:start position:0% +big or its angular momentum but its + + + align:start position:0% +big or its angular momentum but its +angular momentum spinning like this is + + align:start position:0% +angular momentum spinning like this is + + + align:start position:0% +angular momentum spinning like this is +much much larger because you have much + + align:start position:0% +much much larger because you have much + + + align:start position:0% +much much larger because you have much +greater Mr Mr squar okay so you can + + align:start position:0% +greater Mr Mr squar okay so you can + + + align:start position:0% +greater Mr Mr squar okay so you can +leave for the purpose of this problem + + align:start position:0% +leave for the purpose of this problem + + + align:start position:0% +leave for the purpose of this problem +you can treat this as zero and in your + + align:start position:0% +you can treat this as zero and in your + + + align:start position:0% +you can treat this as zero and in your +groups I want you to come up with the + + align:start position:0% +groups I want you to come up with the + + + align:start position:0% +groups I want you to come up with the +Omega Vector H and dhdt so get do get in + + align:start position:0% +Omega Vector H and dhdt so get do get in + + + align:start position:0% +Omega Vector H and dhdt so get do get in +groups talk about it you've got a few + + align:start position:0% +groups talk about it you've got a few + + + align:start position:0% +groups talk about it you've got a few +minutes to do this this one's pretty + + align:start position:0% +minutes to do this this one's pretty + + + align:start position:0% +minutes to do this this one's pretty +straightforward then you can do another + + align:start position:0% +straightforward then you can do another + + + align:start position:0% +straightforward then you can do another +one that's harder so warm up and you + + align:start position:0% +one that's harder so warm up and you + + + align:start position:0% +one that's harder so warm up and you +find a group to work in and you're going + + align:start position:0% +find a group to work in and you're going + + + align:start position:0% +find a group to work in and you're going +to work a couple of problems this got a + + align:start position:0% +to work a couple of problems this got a + + + align:start position:0% +to work a couple of problems this got a +group feels pretty good about their + + align:start position:0% +group feels pretty good about their + + + align:start position:0% +group feels pretty good about their +answer yes all + + align:start position:0% +answer yes all + + + align:start position:0% +answer yes all +right WR it up come up fill in the uh + + align:start position:0% +right WR it up come up fill in the uh + + + align:start position:0% +right WR it up come up fill in the uh +Omega H and + + align:start position:0% + + + + align:start position:0% + +dhdt + + align:start position:0% + + + + align:start position:0% + +okay can everybody see + + align:start position:0% +okay can everybody see + + + align:start position:0% +okay can everybody see +it so you have a z component only for + + align:start position:0% +it so you have a z component only for + + + align:start position:0% +it so you have a z component only for +the Omega a z component K hat only for + + align:start position:0% +the Omega a z component K hat only for + + + align:start position:0% +the Omega a z component K hat only for +eight H and it's I Omega izz Omega and + + align:start position:0% +eight H and it's I Omega izz Omega and + + + align:start position:0% +eight H and it's I Omega izz Omega and +dhdt the only variable here is Omega and + + align:start position:0% +dhdt the only variable here is Omega and + + + align:start position:0% +dhdt the only variable here is Omega and +you get an Omega + + align:start position:0% +you get an Omega + + + align:start position:0% +you get an Omega +Dot and there's no + + align:start position:0% +Dot and there's no + + + align:start position:0% +Dot and there's no +dkdt is zero because it doesn't change + + align:start position:0% +dkdt is zero because it doesn't change + + + align:start position:0% +dkdt is zero because it doesn't change +direction any questions about + + align:start position:0% +direction any questions about + + + align:start position:0% +direction any questions about +this yes um I was a little bit confused + + align:start position:0% +this yes um I was a little bit confused + + + align:start position:0% +this yes um I was a little bit confused +about how we knew like the I K in the H + + align:start position:0% +about how we knew like the I K in the H + + + align:start position:0% +about how we knew like the I K in the H +term is it just because it's only I on + + align:start position:0% +term is it just because it's only I on + + + align:start position:0% +term is it just because it's only I on +the top J the bottom so the convention I + + align:start position:0% +the top J the bottom so the convention I + + + align:start position:0% +the top J the bottom so the convention I +if I understand your question correctly + + align:start position:0% +if I understand your question correctly + + + align:start position:0% +if I understand your question correctly +the convention when you write out the H + + align:start position:0% +the convention when you write out the H + + + align:start position:0% +the convention when you write out the H +Vector is it's the result of + + align:start position:0% + + + + align:start position:0% + +multiplying the three components of the + + align:start position:0% +multiplying the three components of the + + + align:start position:0% +multiplying the three components of the +spin this is the piece in the I + + align:start position:0% +spin this is the piece in the I + + + align:start position:0% +spin this is the piece in the I +Direction J Direction K Direction when + + align:start position:0% +Direction J Direction K Direction when + + + align:start position:0% +Direction J Direction K Direction when +you multiply these out you get + + align:start position:0% +you multiply these out you get + + + align:start position:0% +you multiply these out you get +three results Vector time so this one is + + align:start position:0% +three results Vector time so this one is + + + align:start position:0% +three results Vector time so this one is +HX and it is in the I the second one + + align:start position:0% +HX and it is in the I the second one + + + align:start position:0% +HX and it is in the I the second one +from this times the row middle row gives + + align:start position:0% +from this times the row middle row gives + + + align:start position:0% +from this times the row middle row gives +you Hy and it's in the J and the third + + align:start position:0% +you Hy and it's in the J and the third + + + align:start position:0% +you Hy and it's in the J and the third +one this Vector times these three in the + + align:start position:0% +one this Vector times these three in the + + + align:start position:0% +one this Vector times these three in the +bottom row give you HZ in the + + align:start position:0% + + + + align:start position:0% + +K so I thought when I know it could be + + align:start position:0% +K so I thought when I know it could be + + + align:start position:0% +K so I thought when I know it could be +completely wrong but like multiplication + + align:start position:0% +completely wrong but like multiplication + + + align:start position:0% +completely wrong but like multiplication +you multip like this this this and then + + align:start position:0% +you multip like this this this and then + + + align:start position:0% +you multip like this this this and then +this like you so we have + + align:start position:0% +this like you so we have + + + align:start position:0% +this like you so we have +uh capital a capital b capital c terms + + align:start position:0% +uh capital a capital b capital c terms + + + align:start position:0% +uh capital a capital b capital c terms +in the first row so you do like this and + + align:start position:0% +in the first row so you do like this and + + + align:start position:0% +in the first row so you do like this and +you have a capital little a little B + + align:start position:0% +you have a capital little a little B + + + align:start position:0% +you have a capital little a little B +little C terms in this one when you + + align:start position:0% +little C terms in this one when you + + + align:start position:0% +little C terms in this one when you +multiply this times this you get a A + + align:start position:0% +multiply this times this you get a A + + + align:start position:0% +multiply this times this you get a A +plus BB Plus c c + + align:start position:0% +plus BB Plus c c + + + align:start position:0% +plus BB Plus c c +yeah so that's my question so if you + + align:start position:0% +yeah so that's my question so if you + + + align:start position:0% +yeah so that's my question so if you +have like the Omega X is an I hat Omega + + align:start position:0% +have like the Omega X is an I hat Omega + + + align:start position:0% +have like the Omega X is an I hat Omega +Y is in J hat Omega Z is K hat like how + + align:start position:0% +Y is in J hat Omega Z is K hat like how + + + align:start position:0% +Y is in J hat Omega Z is K hat like how +if you're multiplying like this do you + + align:start position:0% +if you're multiplying like this do you + + + align:start position:0% +if you're multiplying like this do you +get only I hats on the top of the yeah + + align:start position:0% +get only I hats on the top of the yeah + + + align:start position:0% +get only I hats on the top of the yeah +well it's because this isn't just a + + align:start position:0% +well it's because this isn't just a + + + align:start position:0% +well it's because this isn't just a +matrix this is actually a + + align:start position:0% +matrix this is actually a + + + align:start position:0% +matrix this is actually a +tensor and we didn't we haven't gone + + align:start position:0% +tensor and we didn't we haven't gone + + + align:start position:0% +tensor and we didn't we haven't gone +into kind of messy tensor notation but + + align:start position:0% +into kind of messy tensor notation but + + + align:start position:0% +into kind of messy tensor notation but +so you're just being told a convention + + align:start position:0% +so you're just being told a convention + + + align:start position:0% +so you're just being told a convention +here and that is because this is a + + align:start position:0% +here and that is because this is a + + + align:start position:0% +here and that is because this is a +vector being multiplied by a tensor the + + align:start position:0% +vector being multiplied by a tensor the + + + align:start position:0% +vector being multiplied by a tensor the +result what even though this is i j + + align:start position:0% +result what even though this is i j + + + align:start position:0% +result what even though this is i j +k Omega x i times this first term in + + align:start position:0% +k Omega x i times this first term in + + + align:start position:0% +k Omega x i times this first term in +this tensor gives you an it gives you an + + align:start position:0% +this tensor gives you an it gives you an + + + align:start position:0% +this tensor gives you an it gives you an +i back Omega y j times this one gives + + align:start position:0% +i back Omega y j times this one gives + + + align:start position:0% +i back Omega y j times this one gives +you an i back Omega z k times that gives + + align:start position:0% +you an i back Omega z k times that gives + + + align:start position:0% +you an i back Omega z k times that gives +you an i back okay that's what I was + + align:start position:0% +you an i back okay that's what I was + + + align:start position:0% +you an i back okay that's what I was +really and that's a great question + + align:start position:0% +really and that's a great question + + + align:start position:0% +really and that's a great question +because it was wasn't obvious we didn't + + align:start position:0% +because it was wasn't obvious we didn't + + + align:start position:0% +because it was wasn't obvious we didn't +do the full tensor mathematics we just + + align:start position:0% +do the full tensor mathematics we just + + + align:start position:0% +do the full tensor mathematics we just +gave you a result and by definition this + + align:start position:0% +gave you a result and by definition this + + + align:start position:0% +gave you a result and by definition this +row times that is in the I Direction J + + align:start position:0% +row times that is in the I Direction J + + + align:start position:0% +row times that is in the I Direction J +Direction K Direction great question + + align:start position:0% +Direction K Direction great question + + + align:start position:0% +Direction K Direction great question +okay okay so let let's go on the harder + + align:start position:0% +okay okay so let let's go on the harder + + + align:start position:0% +okay okay so let let's go on the harder +problem so you're great at that + + align:start position:0% +problem so you're great at that + + + align:start position:0% +problem so you're great at that +one where we're going to do this one now + + align:start position:0% +one where we're going to do this one now + + + align:start position:0% +one where we're going to do this one now +so this uh so we just did this problem + + align:start position:0% +so this uh so we just did this problem + + + align:start position:0% +so this uh so we just did this problem +all right now we want to do this + + align:start position:0% + + + + align:start position:0% + +problem + + align:start position:0% +problem + + + align:start position:0% +problem +all right and so the + + align:start position:0% +all right and so the + + + align:start position:0% +all right and so the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +same I Matrix + + align:start position:0% +same I Matrix + + + align:start position:0% +same I Matrix +is used + + align:start position:0% +is used + + + align:start position:0% +is used +here it's this one and you can let that + + align:start position:0% +here it's this one and you can let that + + + align:start position:0% +here it's this one and you can let that +term be zero because the coordinate + + align:start position:0% +term be zero because the coordinate + + + align:start position:0% +term be zero because the coordinate +system that has been defined on this + + align:start position:0% +system that has been defined on this + + + align:start position:0% +system that has been defined on this +object is x z y into the board but the + + align:start position:0% +object is x z y into the board but the + + + align:start position:0% +object is x z y into the board but the +direction of spin now is like that we'll + + align:start position:0% +direction of spin now is like that we'll + + + align:start position:0% +direction of spin now is like that we'll +call it cap Omega again but it's in that + + align:start position:0% +call it cap Omega again but it's in that + + + align:start position:0% +call it cap Omega again but it's in that +direction and these are 45 degree angles + + align:start position:0% +direction and these are 45 degree angles + + + align:start position:0% +direction and these are 45 degree angles +for the purposes of this problem so uh + + align:start position:0% +for the purposes of this problem so uh + + + align:start position:0% +for the purposes of this problem so uh +that's s cosine of 45 < tk2 + + align:start position:0% +that's s cosine of 45 < tk2 + + + align:start position:0% +that's s cosine of 45 < tk2 +over2 so now what's + + align:start position:0% +over2 so now what's + + + align:start position:0% +over2 so now what's +Omega what's H and what's dhdt so work + + align:start position:0% +Omega what's H and what's dhdt so work + + + align:start position:0% +Omega what's H and what's dhdt so work +in your groups and sort that one + + align:start position:0% + + + + align:start position:0% + +out you ready to go we can be okay go + + align:start position:0% +out you ready to go we can be okay go + + + align:start position:0% +out you ready to go we can be okay go +for + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +we'll probably do this + + align:start position:0% +we'll probably do this + + + align:start position:0% +we'll probably do this +occasionally and I'm I'll say it again I + + align:start position:0% +occasionally and I'm I'll say it again I + + + align:start position:0% +occasionally and I'm I'll say it again I +have no intention of embarrassing you at + + align:start position:0% +have no intention of embarrassing you at + + + align:start position:0% +have no intention of embarrassing you at +the board so the practice will be you + + align:start position:0% +the board so the practice will be you + + + align:start position:0% +the board so the practice will be you +put your answer up you sit down and then + + align:start position:0% +put your answer up you sit down and then + + + align:start position:0% +put your answer up you sit down and then +we talk about it it's not about you it's + + align:start position:0% +we talk about it it's not about you it's + + + align:start position:0% +we talk about it it's not about you it's +about what's on the board + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +no put the whole thing up yep and if you + + align:start position:0% +no put the whole thing up yep and if you + + + align:start position:0% +no put the whole thing up yep and if you +want to use that big piece of chalk it + + align:start position:0% +want to use that big piece of chalk it + + + align:start position:0% +want to use that big piece of chalk it +shows better just to your + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +okay so let's talk about Omega first how + + align:start position:0% +okay so let's talk about Omega first how + + + align:start position:0% +okay so let's talk about Omega first how +do you figure uh we have a minus < tk2 + + align:start position:0% +do you figure uh we have a minus < tk2 + + + align:start position:0% +do you figure uh we have a minus < tk2 +over2 here can't see that minus < tk2 + + align:start position:0% +over2 here can't see that minus < tk2 + + + align:start position:0% +over2 here can't see that minus < tk2 +over2 Omega i 0 root2 over2 Omega K are + + align:start position:0% +over2 Omega i 0 root2 over2 Omega K are + + + align:start position:0% +over2 Omega i 0 root2 over2 Omega K are +people feel good about that any + + align:start position:0% +people feel good about that any + + + align:start position:0% +people feel good about that any +differences all right so this thing this + + align:start position:0% +differences all right so this thing this + + + align:start position:0% +differences all right so this thing this +Omega that spin clearly has components + + align:start position:0% +Omega that spin clearly has components + + + align:start position:0% +Omega that spin clearly has components +that are like that and like this so this + + align:start position:0% +that are like that and like this so this + + + align:start position:0% +that are like that and like this so this +is your Z piece and your I piece and it + + align:start position:0% +is your Z piece and your I piece and it + + + align:start position:0% +is your Z piece and your I piece and it +is indeed in the minus IAT Direction so + + align:start position:0% +is indeed in the minus IAT Direction so + + + align:start position:0% +is indeed in the minus IAT Direction so +that seems okay and H would be some I + + align:start position:0% +that seems okay and H would be some I + + + align:start position:0% +that seems okay and H would be some I +that the I times + + align:start position:0% +that the I times + + + align:start position:0% +that the I times +Omega and the first term if you'll take + + align:start position:0% +Omega and the first term if you'll take + + + align:start position:0% +Omega and the first term if you'll take +that upper left term as zero then you + + align:start position:0% +that upper left term as zero then you + + + align:start position:0% +that upper left term as zero then you +don't get anything the second term you + + align:start position:0% +don't get anything the second term you + + + align:start position:0% +don't get anything the second term you +don't get anything how so how do how do + + align:start position:0% +don't get anything how so how do how do + + + align:start position:0% +don't get anything how so how do how do +you feel about the angular + + align:start position:0% + + + + align:start position:0% + +momentum any + + align:start position:0% +momentum any + + + align:start position:0% +momentum any +differences okay and the + + align:start position:0% +differences okay and the + + + align:start position:0% +differences okay and the +dhdt uh you take the time derivative of + + align:start position:0% +dhdt uh you take the time derivative of + + + align:start position:0% +dhdt uh you take the time derivative of +this thing you got an Omega dot okay + + align:start position:0% +this thing you got an Omega dot okay + + + align:start position:0% +this thing you got an Omega dot okay +that looks okay as far as it goes but + + align:start position:0% +that looks okay as far as it goes but + + + align:start position:0% +that looks okay as far as it goes but +any other + + align:start position:0% +any other + + + align:start position:0% +any other +thoughts the so K dot is not Zer okay so + + align:start position:0% +thoughts the so K dot is not Zer okay so + + + align:start position:0% +thoughts the so K dot is not Zer okay so +you're saying K hat is changing with + + align:start position:0% +you're saying K hat is changing with + + + align:start position:0% +you're saying K hat is changing with +time yeah and let's think about that so + + align:start position:0% +time yeah and let's think about that so + + + align:start position:0% +time yeah and let's think about that so +it's that's this piece here this is + + align:start position:0% +it's that's this piece here this is + + + align:start position:0% +it's that's this piece here this is +Omega z k + + align:start position:0% +Omega z k + + + align:start position:0% +Omega z k +hat and as this thing goes around that + + align:start position:0% +hat and as this thing goes around that + + + align:start position:0% +hat and as this thing goes around that +unit Vector is doing this right so you + + align:start position:0% +unit Vector is doing this right so you + + + align:start position:0% +unit Vector is doing this right so you +need a dek a DT so do you want to give + + align:start position:0% +need a dek a DT so do you want to give + + + align:start position:0% +need a dek a DT so do you want to give +somebody else give me the second term + + align:start position:0% + + + + align:start position:0% + +here ml + + align:start position:0% +here ml + + + align:start position:0% +here ml +2 time Omega + + align:start position:0% +2 time Omega + + + align:start position:0% +2 time Omega +s because you have the changing + + align:start position:0% +s because you have the changing + + + align:start position:0% +s because you have the changing +direction in your principal axes + + align:start position:0% +direction in your principal axes + + + align:start position:0% +direction in your principal axes +mhm and that's going to be time two okay + + align:start position:0% +mhm and that's going to be time two okay + + + align:start position:0% +mhm and that's going to be time two okay +this is RO omeg Square okay and then + + align:start position:0% +this is RO omeg Square okay and then + + + align:start position:0% +this is RO omeg Square okay and then +what about the < tk2 over2 yeah you + + align:start position:0% +what about the < tk2 over2 yeah you + + + align:start position:0% +what about the < tk2 over2 yeah you +have got a square that too right that' + + align:start position:0% +have got a square that too right that' + + + align:start position:0% +have got a square that too right that' +be squ as well that gives you a + + align:start position:0% +be squ as well that gives you a + + + align:start position:0% +be squ as well that gives you a +half okay and that's that's 12 and + + align:start position:0% +half okay and that's that's 12 and + + + align:start position:0% +half okay and that's that's 12 and +that positive positive yes started out + + align:start position:0% +that positive positive yes started out + + + align:start position:0% +that positive positive yes started out +with a negative + + align:start position:0% +with a negative + + + align:start position:0% +with a negative +but k i cross K is minus J * A minus + + align:start position:0% +but k i cross K is minus J * A minus + + + align:start position:0% +but k i cross K is minus J * A minus +gives you the plus right so this looks + + align:start position:0% +gives you the plus right so this looks + + + align:start position:0% +gives you the plus right so this looks +like this comes out uh ml^ s Omega s j + + align:start position:0% +like this comes out uh ml^ s Omega s j + + + align:start position:0% +like this comes out uh ml^ s Omega s j +hat over 24 I think like that that term + + align:start position:0% +hat over 24 I think like that that term + + + align:start position:0% +hat over 24 I think like that that term +now uh okay and people good with that + + align:start position:0% +now uh okay and people good with that + + + align:start position:0% +now uh okay and people good with that +now so just to remind you + + align:start position:0% +now so just to remind you + + + align:start position:0% +now so just to remind you +um when I was doing these problem when I + + align:start position:0% +um when I was doing these problem when I + + + align:start position:0% +um when I was doing these problem when I +first had to teach this course a few + + align:start position:0% +first had to teach this course a few + + + align:start position:0% +first had to teach this course a few +years ago and I was trying to figure out + + align:start position:0% +years ago and I was trying to figure out + + + align:start position:0% +years ago and I was trying to figure out +you know easy way to teach this and how + + align:start position:0% +you know easy way to teach this and how + + + align:start position:0% +you know easy way to teach this and how +to do these problems I got myself all + + align:start position:0% +to do these problems I got myself all + + + align:start position:0% +to do these problems I got myself all +confused trying to figure out okay which + + align:start position:0% +confused trying to figure out okay which + + + align:start position:0% +confused trying to figure out okay which +components of the rotation Vector are + + align:start position:0% +components of the rotation Vector are + + + align:start position:0% +components of the rotation Vector are +rotating and what do I have to cross + + align:start position:0% +rotating and what do I have to cross + + + align:start position:0% +rotating and what do I have to cross +into it to get the answer and in fact + + align:start position:0% +into it to get the answer and in fact + + + align:start position:0% +into it to get the answer and in fact +you don't have to make it anywhere near + + align:start position:0% +you don't have to make it anywhere near + + + align:start position:0% +you don't have to make it anywhere near +that hard and let's uh take a quick look + + align:start position:0% +that hard and let's uh take a quick look + + + align:start position:0% +that hard and let's uh take a quick look +at something + + align:start position:0% + + + + align:start position:0% + +here H is ml s over + + align:start position:0% +here H is ml s over + + + align:start position:0% +here H is ml s over +12 < tk2 over + + align:start position:0% +12 < tk2 over + + + align:start position:0% +12 < tk2 over +2 where H go < tk2 over to Omega K + + align:start position:0% + + + + align:start position:0% + +hat H is a rotating + + align:start position:0% +hat H is a rotating + + + align:start position:0% +hat H is a rotating +Vector the + + align:start position:0% +Vector the + + + align:start position:0% +Vector the +derivative of a rotating + + align:start position:0% +derivative of a rotating + + + align:start position:0% +derivative of a rotating +Vector in an inertial + + align:start position:0% +Vector in an inertial + + + align:start position:0% +Vector in an inertial +frame is the derivative + + align:start position:0% +frame is the derivative + + + align:start position:0% +frame is the derivative +of that rotating Vector in the rotating + + align:start position:0% +of that rotating Vector in the rotating + + + align:start position:0% +of that rotating Vector in the rotating +frame which is the same thing as saying + + align:start position:0% +frame which is the same thing as saying + + + align:start position:0% +frame which is the same thing as saying +that Omega is zero that's the change in + + align:start position:0% +that Omega is zero that's the change in + + + align:start position:0% +that Omega is zero that's the change in +length of the vector plus Omega cross H + + align:start position:0% +length of the vector plus Omega cross H + + + align:start position:0% +length of the vector plus Omega cross H +Let's test that and to see if that that + + align:start position:0% +Let's test that and to see if that that + + + align:start position:0% +Let's test that and to see if that that +gives us the right answer this + + align:start position:0% +gives us the right answer this + + + align:start position:0% +gives us the right answer this +derivative gives you all that does is + + align:start position:0% +derivative gives you all that does is + + + align:start position:0% +derivative gives you all that does is +gives you the Theta the Omega dot back + + align:start position:0% +gives you the Theta the Omega dot back + + + align:start position:0% +gives you the Theta the Omega dot back +right that's that first term and the + + align:start position:0% +right that's that first term and the + + + align:start position:0% +right that's that first term and the +second term should just then look like + + align:start position:0% +second term should just then look like + + + align:start position:0% +second term should just then look like +uh your Omega which is Omega < tk2 + + align:start position:0% +uh your Omega which is Omega < tk2 + + + align:start position:0% +uh your Omega which is Omega < tk2 +minus root 2 over 2 cap Omega I plus < + + align:start position:0% +minus root 2 over 2 cap Omega I plus < + + + align:start position:0% +minus root 2 over 2 cap Omega I plus < +tk2 over 2 cap Omega + + align:start position:0% +tk2 over 2 cap Omega + + + align:start position:0% +tk2 over 2 cap Omega +K + + align:start position:0% +K + + + align:start position:0% +K +cross a bunch of + + align:start position:0% + + + + align:start position:0% + +constants times K + + align:start position:0% + + + + align:start position:0% + +right so the k cross K + + align:start position:0% + + + + align:start position:0% + +terms are zero the I cross + + align:start position:0% +terms are zero the I cross + + + align:start position:0% +terms are zero the I cross +K minus J and so you get < tk2 over2 * < + + align:start position:0% +K minus J and so you get < tk2 over2 * < + + + align:start position:0% +K minus J and so you get < tk2 over2 * < +tk2 over2 you get uh in you just get + + align:start position:0% +tk2 over2 you get uh in you just get + + + align:start position:0% +tk2 over2 you get uh in you just get +what's in h here multiplied byun2 over2 + + align:start position:0% +what's in h here multiplied byun2 over2 + + + align:start position:0% +what's in h here multiplied byun2 over2 +Omega hat and you get back + + align:start position:0% +Omega hat and you get back + + + align:start position:0% +Omega hat and you get back +exactly these two + + align:start position:0% +exactly these two + + + align:start position:0% +exactly these two +terms so it's that easy you know it's + + align:start position:0% +terms so it's that easy you know it's + + + align:start position:0% +terms so it's that easy you know it's +just the derivative of rotating Vector + + align:start position:0% +just the derivative of rotating Vector + + + align:start position:0% +just the derivative of rotating Vector +just doing Omega cross H is the easiest + + align:start position:0% +just doing Omega cross H is the easiest + + + align:start position:0% +just doing Omega cross H is the easiest +way to deal with + + align:start position:0% +way to deal with + + + align:start position:0% +way to deal with +that derivative of the rotating + + align:start position:0% + + + + align:start position:0% + +piece and any rotating Vector you can + + align:start position:0% +piece and any rotating Vector you can + + + align:start position:0% +piece and any rotating Vector you can +take his time derivative that way all + + align:start position:0% +take his time derivative that way all + + + align:start position:0% +take his time derivative that way all +right we've got a few minutes uh I want + + align:start position:0% +right we've got a few minutes uh I want + + + align:start position:0% +right we've got a few minutes uh I want +actually any other questions about this + + align:start position:0% +actually any other questions about this + + + align:start position:0% +actually any other questions about this +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +problem you in physics most of the + + align:start position:0% +problem you in physics most of the + + + align:start position:0% +problem you in physics most of the +problems you've worked before were it + + align:start position:0% +problems you've worked before were it + + + align:start position:0% +problems you've worked before were it +involved rotation are planer we call + + align:start position:0% +involved rotation are planer we call + + + align:start position:0% +involved rotation are planer we call +planer motion problems the axis of spin + + align:start position:0% +planer motion problems the axis of spin + + + align:start position:0% +planer motion problems the axis of spin +was always perpendicular to the plane + + align:start position:0% +was always perpendicular to the plane + + + align:start position:0% +was always perpendicular to the plane +and the rest of the problem was confined + + align:start position:0% +and the rest of the problem was confined + + + align:start position:0% +and the rest of the problem was confined +to the plane you know so hockey pucks + + align:start position:0% +to the plane you know so hockey pucks + + + align:start position:0% +to the plane you know so hockey pucks +sliding along and stuff like that and + + align:start position:0% +sliding along and stuff like that and + + + align:start position:0% +sliding along and stuff like that and +the but it was always assumed that the + + align:start position:0% +the but it was always assumed that the + + + align:start position:0% +the but it was always assumed that the +axis of uh rotation was perpendicular to + + align:start position:0% +axis of uh rotation was perpendicular to + + + align:start position:0% +axis of uh rotation was perpendicular to +the plane and that the angular momentum + + align:start position:0% +the plane and that the angular momentum + + + align:start position:0% +the plane and that the angular momentum +was + + align:start position:0% +was + + + align:start position:0% +was +parallel so this is actually this these + + align:start position:0% +parallel so this is actually this these + + + align:start position:0% +parallel so this is actually this these +are this is a 3D problem this is a 3D + + align:start position:0% +are this is a 3D problem this is a 3D + + + align:start position:0% +are this is a 3D problem this is a 3D +Dynamics problem as soon as is that H + + align:start position:0% +Dynamics problem as soon as is that H + + + align:start position:0% +Dynamics problem as soon as is that H +and the Omega are different directions + + align:start position:0% +and the Omega are different directions + + + align:start position:0% +and the Omega are different directions +you can come up with torqus in all three + + align:start position:0% +you can come up with torqus in all three + + + align:start position:0% +you can come up with torqus in all three +directions right + + align:start position:0% +directions right + + + align:start position:0% +directions right +okay all right is + + align:start position:0% +okay all right is + + + align:start position:0% +okay all right is +um + + align:start position:0% +um + + + align:start position:0% +um +so any other questions about this and if + + align:start position:0% +so any other questions about this and if + + + align:start position:0% +so any other questions about this and if +not I want to talk about something that + + align:start position:0% +not I want to talk about something that + + + align:start position:0% +not I want to talk about something that +was on the + + align:start position:0% + + + + align:start position:0% + +quiz + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +here's this this this is the one problem + + align:start position:0% +here's this this this is the one problem + + + align:start position:0% +here's this this this is the one problem +on the quiz that gave more conceptual + + align:start position:0% +on the quiz that gave more conceptual + + + align:start position:0% +on the quiz that gave more conceptual +difficulty than any other single problem + + align:start position:0% +difficulty than any other single problem + + + align:start position:0% +difficulty than any other single problem +you know people made mistakes on other + + align:start position:0% +you know people made mistakes on other + + + align:start position:0% +you know people made mistakes on other +problems but got into conceptual trouble + + align:start position:0% +problems but got into conceptual trouble + + + align:start position:0% +problems but got into conceptual trouble +with this problem remember you had a + + align:start position:0% +with this problem remember you had a + + + align:start position:0% +with this problem remember you had a +vehicle driving up a bridge and the + + align:start position:0% +vehicle driving up a bridge and the + + + align:start position:0% +vehicle driving up a bridge and the +bridge could be changing has some + + align:start position:0% +bridge could be changing has some + + + align:start position:0% +bridge could be changing has some +angular rate and it has some angular + + align:start position:0% +angular rate and it has some angular + + + align:start position:0% +angular rate and it has some angular +acceleration and we said to keep the + + align:start position:0% +acceleration and we said to keep the + + + align:start position:0% +acceleration and we said to keep the +problem simple that you could treat this + + align:start position:0% +problem simple that you could treat this + + + align:start position:0% +problem simple that you could treat this +as a particle and that really means you + + align:start position:0% +as a particle and that really means you + + + align:start position:0% +as a particle and that really means you +didn't have to deal with angular + + align:start position:0% +didn't have to deal with angular + + + align:start position:0% +didn't have to deal with angular +momentum I Omega for the object it's + + align:start position:0% +momentum I Omega for the object it's + + + align:start position:0% +momentum I Omega for the object it's +treated like a + + align:start position:0% +treated like a + + + align:start position:0% +treated like a +particle and one of the where + + align:start position:0% +particle and one of the where + + + align:start position:0% +particle and one of the where +people got where the confusion came from + + align:start position:0% +people got where the confusion came from + + + align:start position:0% +people got where the confusion came from +was in figuring out fre B + + align:start position:0% +was in figuring out fre B + + + align:start position:0% +was in figuring out fre B +diagrams you're told in the problem the + + align:start position:0% +diagrams you're told in the problem the + + + align:start position:0% +diagrams you're told in the problem the +language is something like the action of + + align:start position:0% +language is something like the action of + + + align:start position:0% +language is something like the action of +the tires on the road result in a net + + align:start position:0% +the tires on the road result in a net + + + align:start position:0% +the tires on the road result in a net +force up the incline called + + align:start position:0% +force up the incline called + + + align:start position:0% +force up the incline called +T and we didn't call it friction we + + align:start position:0% +T and we didn't call it friction we + + + align:start position:0% +T and we didn't call it friction we +didn't say anything but + + align:start position:0% +didn't say anything but + + + align:start position:0% +didn't say anything but +people a number of people got confused + + align:start position:0% +people a number of people got confused + + + align:start position:0% +people a number of people got confused +about what's that have to do with + + align:start position:0% +about what's that have to do with + + + align:start position:0% +about what's that have to do with +friction how does friction come into + + align:start position:0% +friction how does friction come into + + + align:start position:0% +friction how does friction come into +this okay so let's do the free body + + align:start position:0% +this okay so let's do the free body + + + align:start position:0% +this okay so let's do the free body +diagram for this thing so tell me what's + + align:start position:0% +diagram for this thing so tell me what's + + + align:start position:0% +diagram for this thing so tell me what's +here's my car tell me what to put on the + + align:start position:0% +here's my car tell me what to put on the + + + align:start position:0% +here's my car tell me what to put on the +free body + + align:start position:0% + + + + align:start position:0% + +diagram wait okay mg all right so you + + align:start position:0% +diagram wait okay mg all right so you + + + align:start position:0% +diagram wait okay mg all right so you +got an + + align:start position:0% + + + + align:start position:0% + +mg + + align:start position:0% + + + + align:start position:0% + +next a norm Force okay that's going this + + align:start position:0% +next a norm Force okay that's going this + + + align:start position:0% +next a norm Force okay that's going this +way we'll call + + align:start position:0% + + + + align:start position:0% + +it got T + + align:start position:0% +it got T + + + align:start position:0% +it got T +okay now what about the tires on the + + align:start position:0% +okay now what about the tires on the + + + align:start position:0% +okay now what about the tires on the +road what about + + align:start position:0% +road what about + + + align:start position:0% +road what about +friction pardon that's T that is T so + + align:start position:0% +friction pardon that's T that is T so + + + align:start position:0% +friction pardon that's T that is T so +you think of the free body diagram you + + align:start position:0% +you think of the free body diagram you + + + align:start position:0% +you think of the free body diagram you +just say what are all the possible + + align:start position:0% +just say what are all the possible + + + align:start position:0% +just say what are all the possible +sources of external force on this thing + + align:start position:0% +sources of external force on this thing + + + align:start position:0% +sources of external force on this thing +and they come from Gravity a body Force + + align:start position:0% +and they come from Gravity a body Force + + + align:start position:0% +and they come from Gravity a body Force +and then other things that are in + + align:start position:0% +and then other things that are in + + + align:start position:0% +and then other things that are in +contact with it and the wheels are in + + align:start position:0% +contact with it and the wheels are in + + + align:start position:0% +contact with it and the wheels are in +contact with the road and through the + + align:start position:0% +contact with the road and through the + + + align:start position:0% +contact with the road and through the +wheels you get the normal force and + + align:start position:0% +wheels you get the normal force and + + + align:start position:0% +wheels you get the normal force and +through the wheels you get any Act of + + align:start position:0% +through the wheels you get any Act of + + + align:start position:0% +through the wheels you get any Act of +friction so that is the that's the total + + align:start position:0% +friction so that is the that's the total + + + align:start position:0% +friction so that is the that's the total +net friction + + align:start position:0% +net friction + + + align:start position:0% +net friction +Force + + align:start position:0% +Force + + + align:start position:0% +Force +so and then once you got that far you + + align:start position:0% +so and then once you got that far you + + + align:start position:0% +so and then once you got that far you +were asked to come up with an equation + + align:start position:0% +were asked to come up with an equation + + + align:start position:0% +were asked to come up with an equation +of motion in this + + align:start position:0% +of motion in this + + + align:start position:0% +of motion in this +direction in the uh direction of the + + align:start position:0% +direction in the uh direction of the + + + align:start position:0% +direction in the uh direction of the +bridge and how do you so when you go to + + align:start position:0% +bridge and how do you so when you go to + + + align:start position:0% +bridge and how do you so when you go to +get an equation of motion you say the + + align:start position:0% +get an equation of motion you say the + + + align:start position:0% +get an equation of motion you say the +sum of the external forces is equal + + align:start position:0% + + + + align:start position:0% + +to and we'll make these in the X + + align:start position:0% +to and we'll make these in the X + + + align:start position:0% +to and we'll make these in the X +Direction here is the mass times the + + align:start position:0% +Direction here is the mass times the + + + align:start position:0% +Direction here is the mass times the +acceleration in the X Direction and how + + align:start position:0% +acceleration in the X Direction and how + + + align:start position:0% +acceleration in the X Direction and how +would what terms + + align:start position:0% +would what terms + + + align:start position:0% +would what terms +appear + + align:start position:0% +appear + + + align:start position:0% +appear +pardon well those are the forces they're + + align:start position:0% +pardon well those are the forces they're + + + align:start position:0% +pardon well those are the forces they're +on the other side I want you to come up + + align:start position:0% +on the other side I want you to come up + + + align:start position:0% +on the other side I want you to come up +with the acceleration you need to come + + align:start position:0% +with the acceleration you need to come + + + align:start position:0% +with the acceleration you need to come +up with the acceleration + + align:start position:0% +up with the acceleration + + + align:start position:0% +up with the acceleration +terms + + align:start position:0% + + + + align:start position:0% + +pardon so this probably most most easily + + align:start position:0% +pardon so this probably most most easily + + + align:start position:0% +pardon so this probably most most easily +to Think Through I think in terms of R + + align:start position:0% +to Think Through I think in terms of R + + + align:start position:0% +to Think Through I think in terms of R +and Theta and polar coordinates because + + align:start position:0% +and Theta and polar coordinates because + + + align:start position:0% +and Theta and polar coordinates because +you've been you've worked dozens of + + align:start position:0% +you've been you've worked dozens of + + + align:start position:0% +you've been you've worked dozens of +times with the complete acceleration of + + align:start position:0% +times with the complete acceleration of + + + align:start position:0% +times with the complete acceleration of +something in a rotating system and this + + align:start position:0% +something in a rotating system and this + + + align:start position:0% +something in a rotating system and this +is a rotating + + align:start position:0% +is a rotating + + + align:start position:0% +is a rotating +system polar coordinates is a pretty + + align:start position:0% +system polar coordinates is a pretty + + + align:start position:0% +system polar coordinates is a pretty +easy good way to do this problem so uh + + align:start position:0% +easy good way to do this problem so uh + + + align:start position:0% +easy good way to do this problem so uh +what are the accelerations in this + + align:start position:0% + + + + align:start position:0% + +direction + + align:start position:0% +direction + + + align:start position:0% +direction +R well I do it in terms of well I do it + + align:start position:0% +R well I do it in terms of well I do it + + + align:start position:0% +R well I do it in terms of well I do it +in terms of R and Theta you given a + + align:start position:0% +in terms of R and Theta you given a + + + align:start position:0% +in terms of R and Theta you given a +Theta Dot and a Theta double dot and x + + align:start position:0% +Theta Dot and a Theta double dot and x + + + align:start position:0% +Theta Dot and a Theta double dot and x +and R amount up to + + align:start position:0% +and R amount up to + + + align:start position:0% +and R amount up to +the same thing but I if you call it R + + align:start position:0% +the same thing but I if you call it R + + + align:start position:0% +the same thing but I if you call it R +you'll recognize the terms in your + + align:start position:0% +you'll recognize the terms in your + + + align:start position:0% +you'll recognize the terms in your +acceleration equation so what are the + + align:start position:0% +acceleration equation so what are the + + + align:start position:0% +acceleration equation so what are the +accelerations in the + + align:start position:0% +accelerations in the + + + align:start position:0% +accelerations in the +Direction up the + + align:start position:0% + + + + align:start position:0% + +bridge + + align:start position:0% + + + + align:start position:0% + +okay and those are all in the all it in + + align:start position:0% +okay and those are all in the all it in + + + align:start position:0% +okay and those are all in the all it in +the eye Direction and then if you looked + + align:start position:0% +the eye Direction and then if you looked + + + align:start position:0% +the eye Direction and then if you looked +at that that you obviously could replace + + align:start position:0% +at that that you obviously could replace + + + align:start position:0% +at that that you obviously could replace +rouble dot with X double dot r with X if + + align:start position:0% +rouble dot with X double dot r with X if + + + align:start position:0% +rouble dot with X double dot r with X if +you make your + + align:start position:0% +you make your + + + align:start position:0% +you make your +origin + + align:start position:0% +origin + + + align:start position:0% +origin +here you probably would it's the point + + align:start position:0% +here you probably would it's the point + + + align:start position:0% +here you probably would it's the point +of rotation so that is your that's the + + align:start position:0% +of rotation so that is your that's the + + + align:start position:0% +of rotation so that is your that's the +mass times the acceleration in the + + align:start position:0% +mass times the acceleration in the + + + align:start position:0% +mass times the acceleration in the +direction travel and it's got to be + + align:start position:0% +direction travel and it's got to be + + + align:start position:0% +direction travel and it's got to be +equal to T and minus + + align:start position:0% +equal to T and minus + + + align:start position:0% +equal to T and minus +mg sin Theta probably right and that's + + align:start position:0% +mg sin Theta probably right and that's + + + align:start position:0% +mg sin Theta probably right and that's +one equation of motion you're going to + + align:start position:0% +one equation of motion you're going to + + + align:start position:0% +one equation of motion you're going to +did another equation of motion in the + + align:start position:0% +did another equation of motion in the + + + align:start position:0% +did another equation of motion in the +Theta do theta hat Direction because + + align:start position:0% +Theta do theta hat Direction because + + + align:start position:0% +Theta do theta hat Direction because +what other what accelerations are + + align:start position:0% +what other what accelerations are + + + align:start position:0% +what other what accelerations are +present in this direction in the y j + + align:start position:0% +present in this direction in the y j + + + align:start position:0% +present in this direction in the y j +hat Thea double dot Theta double dot + + align:start position:0% +hat Thea double dot Theta double dot + + + align:start position:0% +hat Thea double dot Theta double dot +your oil Arian one yeah what + + align:start position:0% +your oil Arian one yeah what + + + align:start position:0% +your oil Arian one yeah what +else so the sum of the forces in the + + align:start position:0% + + + + align:start position:0% + +Y so they are in terms of polar + + align:start position:0% +Y so they are in terms of polar + + + align:start position:0% +Y so they are in terms of polar +coordinate + + align:start position:0% + + + + align:start position:0% + +terms well somebody said this one first + + align:start position:0% +terms well somebody said this one first + + + align:start position:0% +terms well somebody said this one first +plus + + align:start position:0% +plus + + + align:start position:0% +plus +two Thea dot is + + align:start position:0% + + + + align:start position:0% + +your + + align:start position:0% +your + + + align:start position:0% +your +right 2 Theta dot r dot and that's in + + align:start position:0% +right 2 Theta dot r dot and that's in + + + align:start position:0% +right 2 Theta dot r dot and that's in +the J Direction and now you've got now + + align:start position:0% +the J Direction and now you've got now + + + align:start position:0% +the J Direction and now you've got now +you can work the + + align:start position:0% + + + + align:start position:0% + +problem so how would you go about doing + + align:start position:0% +problem so how would you go about doing + + + align:start position:0% +problem so how would you go about doing +this + + align:start position:0% +this + + + align:start position:0% +this +problem where you can't treat it as a + + align:start position:0% +problem where you can't treat it as a + + + align:start position:0% +problem where you can't treat it as a +particle any + + align:start position:0% + + + + align:start position:0% + +longer and we've graduated to + + align:start position:0% +longer and we've graduated to + + + align:start position:0% +longer and we've graduated to +that because we've been doing we've been + + align:start position:0% +that because we've been doing we've been + + + align:start position:0% +that because we've been doing we've been +doing angular momentum stuff with mass + + align:start position:0% +doing angular momentum stuff with mass + + + align:start position:0% +doing angular momentum stuff with mass +moment of inertia matrices so now you uh + + align:start position:0% +moment of inertia matrices so now you uh + + + align:start position:0% +moment of inertia matrices so now you uh +you want to do this more as a + + align:start position:0% +you want to do this more as a + + + align:start position:0% +you want to do this more as a +full-fledged Dynamics problem taking + + align:start position:0% +full-fledged Dynamics problem taking + + + align:start position:0% +full-fledged Dynamics problem taking +into consideration that so how do you + + align:start position:0% +into consideration that so how do you + + + align:start position:0% +into consideration that so how do you +what is the mass what do you have to + + align:start position:0% +what is the mass what do you have to + + + align:start position:0% +what is the mass what do you have to +modify the do to modify + + align:start position:0% +modify the do to modify + + + align:start position:0% +modify the do to modify +our free body + + align:start position:0% + + + + align:start position:0% + +diagram here's my simplified vehicle + + align:start position:0% +diagram here's my simplified vehicle + + + align:start position:0% +diagram here's my simplified vehicle +what are the forces on it that you need + + align:start position:0% +what are the forces on it that you need + + + align:start position:0% +what are the forces on it that you need +to deal + + align:start position:0% +to deal + + + align:start position:0% +to deal +with + + align:start position:0% + + + + align:start position:0% + +yeah so you can add need two because you + + align:start position:0% +yeah so you can add need two because you + + + align:start position:0% +yeah so you can add need two because you +got two wheels on this thing and so + + align:start position:0% +got two wheels on this thing and so + + + align:start position:0% +got two wheels on this thing and so +there's axle one here so you're going to + + align:start position:0% +there's axle one here so you're going to + + + align:start position:0% +there's axle one here so you're going to +one here and then one here I say call + + align:start position:0% +one here and then one here I say call + + + align:start position:0% +one here and then one here I say call +this one N1 N2 what + + align:start position:0% + + + + align:start position:0% + +else the same so you got a g somewhere + + align:start position:0% +else the same so you got a g somewhere + + + align:start position:0% +else the same so you got a g somewhere +and so you still have an mg + + align:start position:0% +and so you still have an mg + + + align:start position:0% +and so you still have an mg +term what other external + + align:start position:0% +term what other external + + + align:start position:0% +term what other external +forces t t but now T is a + + align:start position:0% +forces t t but now T is a + + + align:start position:0% +forces t t but now T is a +problem so I was I gave you before it's + + align:start position:0% +problem so I was I gave you before it's + + + align:start position:0% +problem so I was I gave you before it's +the t is the total net force but that's + + align:start position:0% +the t is the total net force but that's + + + align:start position:0% +the t is the total net force but that's +not adequate in this problem any + + align:start position:0% + + + + align:start position:0% + +longer yeah so we're going to have have + + align:start position:0% +longer yeah so we're going to have have + + + align:start position:0% +longer yeah so we're going to have have +end up having a friction Force that's + + align:start position:0% +end up having a friction Force that's + + + align:start position:0% +end up having a friction Force that's +applied you know + + align:start position:0% +applied you know + + + align:start position:0% +applied you know +here F1 and another one applied here FS2 + + align:start position:0% +here F1 and another one applied here FS2 + + + align:start position:0% +here F1 and another one applied here FS2 +and F1 plus F2 would be t + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so how many unknowns do we + + align:start position:0% + + + + align:start position:0% + +have well it looks like four here plus + + align:start position:0% +have well it looks like four here plus + + + align:start position:0% +have well it looks like four here plus +any motion stuff that you have to solve + + align:start position:0% +any motion stuff that you have to solve + + + align:start position:0% +any motion stuff that you have to solve +for so how many equations of motion can + + align:start position:0% +for so how many equations of motion can + + + align:start position:0% +for so how many equations of motion can +you write remember you get one equation + + align:start position:0% +you write remember you get one equation + + + align:start position:0% +you write remember you get one equation +for every Vector component Direction so + + align:start position:0% +for every Vector component Direction so + + + align:start position:0% +for every Vector component Direction so +XYZ gives you three components and you + + align:start position:0% +XYZ gives you three components and you + + + align:start position:0% +XYZ gives you three components and you +could conceivably rewrite three + + align:start position:0% +could conceivably rewrite three + + + align:start position:0% +could conceivably rewrite three +equations so tell me the relevant + + align:start position:0% +equations so tell me the relevant + + + align:start position:0% +equations so tell me the relevant +equations of motion that we could come + + align:start position:0% +equations of motion that we could come + + + align:start position:0% +equations of motion that we could come +up with for this + + align:start position:0% + + + + align:start position:0% + +problem some forces in X some of forces + + align:start position:0% +problem some forces in X some of forces + + + align:start position:0% +problem some forces in X some of forces +in y okay I I argue a sum of forces in + + align:start position:0% + + + + align:start position:0% + +X that's still true yep sum of forces in + + align:start position:0% +X that's still true yep sum of forces in + + + align:start position:0% +X that's still true yep sum of forces in +y you + + align:start position:0% + + + + align:start position:0% + +said is this + + align:start position:0% +said is this + + + align:start position:0% +said is this +zero no because that bridge is moving + + align:start position:0% +zero no because that bridge is moving + + + align:start position:0% +zero no because that bridge is moving +okay what + + align:start position:0% + + + + align:start position:0% + +else okay and how do you do that sum of + + align:start position:0% +else okay and how do you do that sum of + + + align:start position:0% +else okay and how do you do that sum of +the torqus in what + + align:start position:0% + + + + align:start position:0% + +direction well + + align:start position:0% +direction well + + + align:start position:0% +direction well +no yeah I mean you could excuse me I + + align:start position:0% +no yeah I mean you could excuse me I + + + align:start position:0% +no yeah I mean you could excuse me I +shouldn't say that the um do you have + + align:start position:0% +shouldn't say that the um do you have + + + align:start position:0% +shouldn't say that the um do you have +more than one torque term you can work + + align:start position:0% +more than one torque term you can work + + + align:start position:0% +more than one torque term you can work +with here more than one torque + + align:start position:0% +with here more than one torque + + + align:start position:0% +with here more than one torque +equation + + align:start position:0% + + + + align:start position:0% + +yes yes how's + + align:start position:0% +yes yes how's + + + align:start position:0% +yes yes how's +that so let's just think through these + + align:start position:0% +that so let's just think through these + + + align:start position:0% +that so let's just think through these +things so you could have a torque you + + align:start position:0% +things so you could have a torque you + + + align:start position:0% +things so you could have a torque you +could have a torque in the this is + + align:start position:0% +could have a torque in the this is + + + align:start position:0% +could have a torque in the this is +XY Z out of the board you could have a z + + align:start position:0% +XY Z out of the board you could have a z + + + align:start position:0% +XY Z out of the board you could have a z +torque making this thing trying to pitch + + align:start position:0% +torque making this thing trying to pitch + + + align:start position:0% +torque making this thing trying to pitch +up and + + align:start position:0% +up and + + + align:start position:0% +up and +down uh you could have an X torque + + align:start position:0% +down uh you could have an X torque + + + align:start position:0% +down uh you could have an X torque +making it trying to roll over but we + + align:start position:0% +making it trying to roll over but we + + + align:start position:0% +making it trying to roll over but we +don't have any information in that + + align:start position:0% +don't have any information in that + + + align:start position:0% +don't have any information in that +direction and it's strained and we could + + align:start position:0% +direction and it's strained and we could + + + align:start position:0% +direction and it's strained and we could +have a y torque making it try to go like + + align:start position:0% +have a y torque making it try to go like + + + align:start position:0% +have a y torque making it try to go like +that and we don't have any much + + align:start position:0% +that and we don't have any much + + + align:start position:0% +that and we don't have any much +information there so it seems like we've + + align:start position:0% +information there so it seems like we've + + + align:start position:0% +information there so it seems like we've +got an A Z torque equation that we could + + align:start position:0% + + + + align:start position:0% + +write and that's a one seems like we got + + align:start position:0% +write and that's a one seems like we got + + + align:start position:0% +write and that's a one seems like we got +three equations sum of forces is X sum + + align:start position:0% +three equations sum of forces is X sum + + + align:start position:0% +three equations sum of forces is X sum +of forces Y and a torque in the Z + + align:start position:0% +of forces Y and a torque in the Z + + + align:start position:0% +of forces Y and a torque in the Z +and doesn't seem like quite enough + + align:start position:0% + + + + align:start position:0% + +and that's as far as I've gotten with it + + align:start position:0% +and that's as far as I've gotten with it + + + align:start position:0% +and that's as far as I've gotten with it +I just thought of this on the way over + + align:start position:0% +I just thought of this on the way over + + + align:start position:0% +I just thought of this on the way over +here okay so I'd said i' I'd sit down + + align:start position:0% +here okay so I'd said i' I'd sit down + + + align:start position:0% +here okay so I'd said i' I'd sit down +and start working this out and trying to + + align:start position:0% +and start working this out and trying to + + + align:start position:0% +and start working this out and trying to +figure out okay where's my fourth + + align:start position:0% +figure out okay where's my fourth + + + align:start position:0% +figure out okay where's my fourth +equation going to come + + align:start position:0% + + + + align:start position:0% + +from and I'm not exactly sure quite + + align:start position:0% +from and I'm not exactly sure quite + + + align:start position:0% +from and I'm not exactly sure quite +yet but that generally I'd go about + + align:start position:0% +yet but that generally I'd go about + + + align:start position:0% +yet but that generally I'd go about +setting it up like that and start + + align:start position:0% +setting it up like that and start + + + align:start position:0% +setting it up like that and start +working those things + + align:start position:0% + + + + align:start position:0% + +out okay any other questions or + + align:start position:0% +out okay any other questions or + + + align:start position:0% +out okay any other questions or +questions about the + + align:start position:0% + + + + align:start position:0% + +quiz we're done early \ No newline at end of file diff --git a/7FOFBqw1gMs.txt b/7FOFBqw1gMs.txt new file mode 100644 index 0000000000000000000000000000000000000000..36d57b4aea269c35df513e03619f23674172b6e6 --- /dev/null +++ b/7FOFBqw1gMs.txt @@ -0,0 +1,9805 @@ +align:start position:0% + +hello can people hear me in the back are + + align:start position:0% +hello can people hear me in the back are + + + align:start position:0% +hello can people hear me in the back are +we + + align:start position:0% +we + + + align:start position:0% +we +good okay so uh welcome to the last + + align:start position:0% +good okay so uh welcome to the last + + + align:start position:0% +good okay so uh welcome to the last +lecture of 604 oh no 61200 yeah um I'm + + align:start position:0% +lecture of 604 oh no 61200 yeah um I'm + + + align:start position:0% +lecture of 604 oh no 61200 yeah um I'm +I'm totally sayane I can remember which + + align:start position:0% +I'm totally sayane I can remember which + + + align:start position:0% +I'm totally sayane I can remember which +class I'm teaching uh welcome you made + + align:start position:0% +class I'm teaching uh welcome you made + + + align:start position:0% +class I'm teaching uh welcome you made +it through the semester well + + align:start position:0% +it through the semester well + + + align:start position:0% +it through the semester well +done uh okay so for today's + + align:start position:0% + + + + align:start position:0% + +material we are going to you know wrap + + align:start position:0% +material we are going to you know wrap + + + align:start position:0% +material we are going to you know wrap +up our discussion of + + align:start position:0% +up our discussion of + + + align:start position:0% +up our discussion of +probability and in particular we will be + + align:start position:0% +probability and in particular we will be + + + align:start position:0% +probability and in particular we will be +discussing uh tail bounds so you know uh + + align:start position:0% +discussing uh tail bounds so you know uh + + + align:start position:0% +discussing uh tail bounds so you know uh +what happens if you have a a random + + align:start position:0% +what happens if you have a a random + + + align:start position:0% +what happens if you have a a random +variable like what is the probability + + align:start position:0% +variable like what is the probability + + + align:start position:0% +variable like what is the probability +that this random variable is like very + + align:start position:0% +that this random variable is like very + + + align:start position:0% +that this random variable is like very +large or very small like you know very + + align:start position:0% +large or very small like you know very + + + align:start position:0% +large or very small like you know very +different from from its expectation + + align:start position:0% +different from from its expectation + + + align:start position:0% +different from from its expectation +okay uh so let's start with a a bit a + + align:start position:0% + + + + align:start position:0% + +review uh + + align:start position:0% +review uh + + + align:start position:0% +review uh +variance okay so I think we uh saw from + + align:start position:0% +variance okay so I think we uh saw from + + + align:start position:0% +variance okay so I think we uh saw from +the last not last lecture two lectures + + align:start position:0% +the last not last lecture two lectures + + + align:start position:0% +the last not last lecture two lectures +ago possibly uh so the variance of a + + align:start position:0% +ago possibly uh so the variance of a + + + align:start position:0% +ago possibly uh so the variance of a +random variable + + align:start position:0% + + + + align:start position:0% + +R uh is defined to be the + + align:start position:0% + + + + align:start position:0% + +expectation of uh R minus the + + align:start position:0% +expectation of uh R minus the + + + align:start position:0% +expectation of uh R minus the +expectation of r + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +squared + + align:start position:0% +squared + + + align:start position:0% +squared +okay uh and the standard deviation is + + align:start position:0% +okay uh and the standard deviation is + + + align:start position:0% +okay uh and the standard deviation is +just the square root of that you know if + + align:start position:0% +just the square root of that you know if + + + align:start position:0% +just the square root of that you know if +you've uh taken you know stats or + + align:start position:0% +you've uh taken you know stats or + + + align:start position:0% +you've uh taken you know stats or +anything like that that's probably uh + + align:start position:0% +anything like that that's probably uh + + + align:start position:0% +anything like that that's probably uh +you know something that you've seen more + + align:start position:0% +you know something that you've seen more + + + align:start position:0% +you know something that you've seen more +more often than + + align:start position:0% +more often than + + + align:start position:0% +more often than +variance uh another you know not a + + align:start position:0% +variance uh another you know not a + + + align:start position:0% +variance uh another you know not a +definition but another useful formula an + + align:start position:0% +definition but another useful formula an + + + align:start position:0% +definition but another useful formula an +equivalent formulation of this is that + + align:start position:0% +equivalent formulation of this is that + + + align:start position:0% +equivalent formulation of this is that +the variance of r + + align:start position:0% +the variance of r + + + align:start position:0% +the variance of r +is also equal to the + + align:start position:0% +is also equal to the + + + align:start position:0% +is also equal to the +expectation of r + + align:start position:0% +expectation of r + + + align:start position:0% +expectation of r +s minus the square of the expectation of + + align:start position:0% +s minus the square of the expectation of + + + align:start position:0% +s minus the square of the expectation of +R okay uh so not the definition but it's + + align:start position:0% +R okay uh so not the definition but it's + + + align:start position:0% +R okay uh so not the definition but it's +equivalent and uh I think in recitation + + align:start position:0% +equivalent and uh I think in recitation + + + align:start position:0% +equivalent and uh I think in recitation +perhaps you uh you proved this um this + + align:start position:0% +perhaps you uh you proved this um this + + + align:start position:0% +perhaps you uh you proved this um this +this formula is is a particularly useful + + align:start position:0% +this formula is is a particularly useful + + + align:start position:0% +this formula is is a particularly useful +one for what we're going to be doing + + align:start position:0% +one for what we're going to be doing + + + align:start position:0% +one for what we're going to be doing +today + + align:start position:0% +today + + + align:start position:0% +today +okay uh we also saw that uh you know + + align:start position:0% +okay uh we also saw that uh you know + + + align:start position:0% +okay uh we also saw that uh you know +Varian is linear subject to uh you know + + align:start position:0% +Varian is linear subject to uh you know + + + align:start position:0% +Varian is linear subject to uh you know +certain constraints does anybody + + align:start position:0% +certain constraints does anybody + + + align:start position:0% +certain constraints does anybody +remember what uh what you need for for + + align:start position:0% +remember what uh what you need for for + + + align:start position:0% +remember what uh what you need for for +variance to be + + align:start position:0% + + + + align:start position:0% + +linear + + align:start position:0% +linear + + + align:start position:0% +linear +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +Independence okay so if you + + align:start position:0% +Independence okay so if you + + + align:start position:0% +Independence okay so if you +have R1 + + align:start position:0% +have R1 + + + align:start position:0% +have R1 +R2 RN are + + align:start position:0% +R2 RN are + + + align:start position:0% +R2 RN are +independent + + align:start position:0% +independent + + + align:start position:0% +independent +then uh the variance of the sum is the + + align:start position:0% +then uh the variance of the sum is the + + + align:start position:0% +then uh the variance of the sum is the +sum of the + + align:start position:0% + + + + align:start position:0% + +variances + + align:start position:0% + + + + align:start position:0% + +oops uh is that the right + + align:start position:0% + + + + align:start position:0% + +constraint is it + + align:start position:0% +constraint is it + + + align:start position:0% +constraint is it +correct who who believes this statement + + align:start position:0% + + + + align:start position:0% + +who + + align:start position:0% + + + + align:start position:0% + +disbelieves who's who's still + + align:start position:0% +disbelieves who's who's still + + + align:start position:0% +disbelieves who's who's still +asleep oh okay maybe we'll we'll give it + + align:start position:0% +asleep oh okay maybe we'll we'll give it + + + align:start position:0% +asleep oh okay maybe we'll we'll give it +a few minutes for people to wake + + align:start position:0% +a few minutes for people to wake + + + align:start position:0% +a few minutes for people to wake +up uh okay um well this is a correct + + align:start position:0% +up uh okay um well this is a correct + + + align:start position:0% +up uh okay um well this is a correct +statement uh however there's something + + align:start position:0% +statement uh however there's something + + + align:start position:0% +statement uh however there's something +uh slightly stronger that we can say we + + align:start position:0% +uh slightly stronger that we can say we + + + align:start position:0% +uh slightly stronger that we can say we +can weaken this this condition right we + + align:start position:0% +can weaken this this condition right we + + + align:start position:0% +can weaken this this condition right we +don't need Mutual Independence what do + + align:start position:0% +don't need Mutual Independence what do + + + align:start position:0% +don't need Mutual Independence what do +we actually need + + align:start position:0% + + + + align:start position:0% + +pair ways Independence + + align:start position:0% + + + + align:start position:0% + +yeah okay so if we have a bunch of + + align:start position:0% +yeah okay so if we have a bunch of + + + align:start position:0% +yeah okay so if we have a bunch of +Parise independent random variables we + + align:start position:0% +Parise independent random variables we + + + align:start position:0% +Parise independent random variables we +want to find the variance of their sum + + align:start position:0% +want to find the variance of their sum + + + align:start position:0% +want to find the variance of their sum +we can instead just sum the variances + + align:start position:0% +we can instead just sum the variances + + + align:start position:0% +we can instead just sum the variances +okay so another very useful fact uh + + align:start position:0% +okay so another very useful fact uh + + + align:start position:0% +okay so another very useful fact uh +hopefully you proved it already in + + align:start position:0% +hopefully you proved it already in + + + align:start position:0% +hopefully you proved it already in +recitations so we don't need to go over + + align:start position:0% +recitations so we don't need to go over + + + align:start position:0% +recitations so we don't need to go over +the + + align:start position:0% +the + + + align:start position:0% +the +proof uh but these uh well + + align:start position:0% +proof uh but these uh well + + + align:start position:0% +proof uh but these uh well +these two formulas are going to be quite + + align:start position:0% +these two formulas are going to be quite + + + align:start position:0% +these two formulas are going to be quite +useful + + align:start position:0% + + + + align:start position:0% + +today + + align:start position:0% + + + + align:start position:0% + +okay now time for the first of our + + align:start position:0% + + + + align:start position:0% + +tailbones so before I uh give you the + + align:start position:0% +tailbones so before I uh give you the + + + align:start position:0% +tailbones so before I uh give you the +bound uh let's let's think about an + + align:start position:0% +bound uh let's let's think about an + + + align:start position:0% +bound uh let's let's think about an +example so looking at this room uh + + align:start position:0% +example so looking at this room uh + + + align:start position:0% +example so looking at this room uh +suppose I pick a random student and uh + + align:start position:0% +suppose I pick a random student and uh + + + align:start position:0% +suppose I pick a random student and uh +you know let the random variable R be + + align:start position:0% +you know let the random variable R be + + + align:start position:0% +you know let the random variable R be +the the row that the the randomly picked + + align:start position:0% +the the row that the the randomly picked + + + align:start position:0% +the the row that the the randomly picked +student is is sitting in okay so + + align:start position:0% +student is is sitting in okay so + + + align:start position:0% +student is is sitting in okay so +guesstimate that this is about uh you + + align:start position:0% +guesstimate that this is about uh you + + + align:start position:0% +guesstimate that this is about uh you +know the expectation of R is about eight + + align:start position:0% +know the expectation of R is about eight + + + align:start position:0% +know the expectation of R is about eight +so so pick random + + align:start position:0% + + + + align:start position:0% + +student R is the row + + align:start position:0% + + + + align:start position:0% + +okay so for uh those of you who aren't + + align:start position:0% +okay so for uh those of you who aren't + + + align:start position:0% +okay so for uh those of you who aren't +in the room those of you who are + + align:start position:0% +in the room those of you who are + + + align:start position:0% +in the room those of you who are +watching the video uh what does that + + align:start position:0% +watching the video uh what does that + + + align:start position:0% +watching the video uh what does that +tell them about uh the probability that + + align:start position:0% +tell them about uh the probability that + + + align:start position:0% +tell them about uh the probability that +R is at least + + align:start position:0% + + + + align:start position:0% + +16 so what's the probability that a + + align:start position:0% +16 so what's the probability that a + + + align:start position:0% +16 so what's the probability that a +randomly selected student is sit sitting + + align:start position:0% +randomly selected student is sit sitting + + + align:start position:0% +randomly selected student is sit sitting +in the last five rows I think there 21 + + align:start position:0% +in the last five rows I think there 21 + + + align:start position:0% +in the last five rows I think there 21 +rows here + + align:start position:0% + + + + align:start position:0% + +yeah does anybody have any + + align:start position:0% + + + + align:start position:0% + +idea so maybe I should label this as an + + align:start position:0% + + + + align:start position:0% + +example + + align:start position:0% + + + + align:start position:0% + +yeah one minus the CDF okay so the + + align:start position:0% +yeah one minus the CDF okay so the + + + align:start position:0% +yeah one minus the CDF okay so the +people watching the uh watching the + + align:start position:0% +people watching the uh watching the + + + align:start position:0% +people watching the uh watching the +video can't I assume they can't see the + + align:start position:0% +video can't I assume they can't see the + + + align:start position:0% +video can't I assume they can't see the +room so they don't know what the CD + + align:start position:0% +room so they don't know what the CD + + + align:start position:0% +room so they don't know what the CD +is right the only information they + + align:start position:0% +is right the only information they + + + align:start position:0% +is right the only information they +know is that the expectation is + + align:start position:0% +know is that the expectation is + + + align:start position:0% +know is that the expectation is +eight + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yeah oh can we find the variance from + + align:start position:0% +yeah oh can we find the variance from + + + align:start position:0% +yeah oh can we find the variance from +that and then see how far away we are uh + + align:start position:0% +that and then see how far away we are uh + + + align:start position:0% +that and then see how far away we are uh +no that uh requires more information + + align:start position:0% +no that uh requires more information + + + align:start position:0% +no that uh requires more information +right like we we need to know a little + + align:start position:0% +right like we we need to know a little + + + align:start position:0% +right like we we need to know a little +bit more about uh about what's going on + + align:start position:0% +bit more about uh about what's going on + + + align:start position:0% +bit more about uh about what's going on +right like we we need to you know + + align:start position:0% +right like we we need to you know + + + align:start position:0% +right like we we need to you know +somehow figure out you know the + + align:start position:0% +somehow figure out you know the + + + align:start position:0% +somehow figure out you know the +expectation of R minus 8 squar so like + + align:start position:0% +expectation of R minus 8 squar so like + + + align:start position:0% +expectation of R minus 8 squar so like +we need to know something more about R + + align:start position:0% +we need to know something more about R + + + align:start position:0% +we need to know something more about R +than than just its + + align:start position:0% +than than just its + + + align:start position:0% +than than just its +expectation + + align:start position:0% + + + + align:start position:0% + +yeah yes there're 21 so 0 through + + align:start position:0% +yeah yes there're 21 so 0 through + + + align:start position:0% +yeah yes there're 21 so 0 through + + align:start position:0% + + + + align:start position:0% + +yeah can we assume that it's uniformally + + align:start position:0% +yeah can we assume that it's uniformally + + + align:start position:0% +yeah can we assume that it's uniformally +distributed uh no and in fact it it is + + align:start position:0% +distributed uh no and in fact it it is + + + align:start position:0% +distributed uh no and in fact it it is +not uh there seem to be + + align:start position:0% +not uh there seem to be + + + align:start position:0% +not uh there seem to be +you know more students towards the front + + align:start position:0% +you know more students towards the front + + + align:start position:0% +you know more students towards the front +than than towards the back + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% + + + + align:start position:0% + +yeah so your intuition is great though + + align:start position:0% +yeah so your intuition is great though + + + align:start position:0% +yeah so your intuition is great though +right so um well we're using the + + align:start position:0% +right so um well we're using the + + + align:start position:0% +right so um well we're using the +observation that uh that you know 16 is + + align:start position:0% +observation that uh that you know 16 is + + + align:start position:0% +observation that uh that you know 16 is +is twice 8 right we're we're also using + + align:start position:0% +is twice 8 right we're we're also using + + + align:start position:0% +is twice 8 right we're we're also using +the observation that uh you know the + + align:start position:0% +the observation that uh you know the + + + align:start position:0% +the observation that uh you know the +rows are numbered 0 through 20 like + + align:start position:0% +rows are numbered 0 through 20 like + + + align:start position:0% +rows are numbered 0 through 20 like +they're they're non + + align:start position:0% +they're they're non + + + align:start position:0% +they're they're non +negative okay so what + + align:start position:0% +negative okay so what + + + align:start position:0% +negative okay so what +happens if you know more than half of + + align:start position:0% +happens if you know more than half of + + + align:start position:0% +happens if you know more than half of +the + + align:start position:0% +the + + + align:start position:0% +the +students are sitting in the back five + + align:start position:0% +students are sitting in the back five + + + align:start position:0% +students are sitting in the back five +rows + + align:start position:0% + + + + align:start position:0% + +what does that tell us about the + + align:start position:0% + + + + align:start position:0% + +expectation well if if more than half of + + align:start position:0% +expectation well if if more than half of + + + align:start position:0% +expectation well if if more than half of +the students you know give us R is is at + + align:start position:0% +the students you know give us R is is at + + + align:start position:0% +the students you know give us R is is at +least + + align:start position:0% +least + + + align:start position:0% +least +16 right that tells us that the + + align:start position:0% +16 right that tells us that the + + + align:start position:0% +16 right that tells us that the +expectation should be at least + + align:start position:0% +expectation should be at least + + + align:start position:0% +expectation should be at least +eight right or sorry more than + + align:start position:0% +eight right or sorry more than + + + align:start position:0% +eight right or sorry more than +eight if if more than half of the + + align:start position:0% +eight if if more than half of the + + + align:start position:0% +eight if if more than half of the +students are in the back okay so the + + align:start position:0% +students are in the back okay so the + + + align:start position:0% +students are in the back okay so the +converse of + + align:start position:0% +converse of + + + align:start position:0% +converse of +that is that there are at most half of + + align:start position:0% +that is that there are at most half of + + + align:start position:0% +that is that there are at most half of +the students in the back five + + align:start position:0% +the students in the back five + + + align:start position:0% +the students in the back five +rows okay so let's try and formalize + + align:start position:0% +rows okay so let's try and formalize + + + align:start position:0% +rows okay so let's try and formalize +this + + align:start position:0% +this + + + align:start position:0% +this +intuition so this is what's known as + + align:start position:0% +intuition so this is what's known as + + + align:start position:0% +intuition so this is what's known as +Markov in + + align:start position:0% + + + + align:start position:0% + +equality uh so let R be a non- negative + + align:start position:0% + + + + align:start position:0% + +random + + align:start position:0% + + + + align:start position:0% + +variable uh then the + + align:start position:0% +variable uh then the + + + align:start position:0% +variable uh then the +probability that R is greater than or + + align:start position:0% +probability that R is greater than or + + + align:start position:0% +probability that R is greater than or +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +X is less than or equal to the + + align:start position:0% +X is less than or equal to the + + + align:start position:0% +X is less than or equal to the +expectation of + + align:start position:0% +expectation of + + + align:start position:0% +expectation of +r divided by + + align:start position:0% +r divided by + + + align:start position:0% +r divided by +X + + align:start position:0% +X + + + align:start position:0% +X +okay so for the example that we just saw + + align:start position:0% +okay so for the example that we just saw + + + align:start position:0% +okay so for the example that we just saw +right the probability that uh R is at + + align:start position:0% +right the probability that uh R is at + + + align:start position:0% +right the probability that uh R is at +least + + align:start position:0% +least + + + align:start position:0% +least +16 it's at most the expectation which is + + align:start position:0% +16 it's at most the expectation which is + + + align:start position:0% +16 it's at most the expectation which is +8 ID 16 so that gives us 1 + + align:start position:0% +8 ID 16 so that gives us 1 + + + align:start position:0% +8 ID 16 so that gives us 1 +12 okay does the uh does the statement + + align:start position:0% +12 okay does the uh does the statement + + + align:start position:0% +12 okay does the uh does the statement +make sense to + + align:start position:0% + + + + align:start position:0% + +people so basically it's saying that you + + align:start position:0% +people so basically it's saying that you + + + align:start position:0% +people so basically it's saying that you +know you can't have too many super large + + align:start position:0% +know you can't have too many super large + + + align:start position:0% +know you can't have too many super large +values because that would push the + + align:start position:0% +values because that would push the + + + align:start position:0% +values because that would push the +expectation up too + + align:start position:0% +expectation up too + + + align:start position:0% +expectation up too +high + + align:start position:0% +high + + + align:start position:0% +high +okay so how could we prove + + align:start position:0% + + + + align:start position:0% + +this any ideas how do we formalize the + + align:start position:0% +this any ideas how do we formalize the + + + align:start position:0% +this any ideas how do we formalize the +intuition that we were just talking + + align:start position:0% + + + + align:start position:0% + +about let's try let's try using the law + + align:start position:0% +about let's try let's try using the law + + + align:start position:0% +about let's try let's try using the law +of total expectation + + align:start position:0% +of total expectation + + + align:start position:0% +of total expectation +so how can we write the expectation of + + align:start position:0% +so how can we write the expectation of + + + align:start position:0% +so how can we write the expectation of +R what might we condition + + align:start position:0% + + + + align:start position:0% + +on we don't have too many events that we + + align:start position:0% +on we don't have too many events that we + + + align:start position:0% +on we don't have too many events that we +can work with + + align:start position:0% + + + + align:start position:0% + +right which of them might be useful + + align:start position:0% + + + + align:start position:0% + +nobody so let's try let's try + + align:start position:0% + + + + align:start position:0% + +conditioning on X greater than oh wait + + align:start position:0% +conditioning on X greater than oh wait + + + align:start position:0% +conditioning on X greater than oh wait +was it + + align:start position:0% +was it + + + align:start position:0% +was it +x + + align:start position:0% +x + + + align:start position:0% +x +uh yeah R greater than or equal + + align:start position:0% +uh yeah R greater than or equal + + + align:start position:0% +uh yeah R greater than or equal +x + + align:start position:0% +x + + + align:start position:0% +x +okay so what does the law of total + + align:start position:0% +okay so what does the law of total + + + align:start position:0% +okay so what does the law of total +expectation tell + + align:start position:0% +expectation tell + + + align:start position:0% +expectation tell +us well this is going to be the + + align:start position:0% +us well this is going to be the + + + align:start position:0% +us well this is going to be the +expectation of our conditioned on R + + align:start position:0% +expectation of our conditioned on R + + + align:start position:0% +expectation of our conditioned on R +being greater than x + + align:start position:0% + + + + align:start position:0% + +multiplied by the probability that R is + + align:start position:0% +multiplied by the probability that R is + + + align:start position:0% +multiplied by the probability that R is +greater than + + align:start position:0% + + + + align:start position:0% + +x okay + + align:start position:0% +x okay + + + align:start position:0% +x okay +plus the + + align:start position:0% +plus the + + + align:start position:0% +plus the +expectation are conditioned on R less + + align:start position:0% +expectation are conditioned on R less + + + align:start position:0% +expectation are conditioned on R less +than + + align:start position:0% + + + + align:start position:0% + +x times that + + align:start position:0% + + + + align:start position:0% + +probability okay do people remember that + + align:start position:0% +probability okay do people remember that + + + align:start position:0% +probability okay do people remember that +that coming back hopefully yes no maybe + + align:start position:0% +that coming back hopefully yes no maybe + + + align:start position:0% +that coming back hopefully yes no maybe +few + + align:start position:0% +few + + + align:start position:0% +few +nods + + align:start position:0% +nods + + + align:start position:0% +nods +okay so what do we know about each of + + align:start position:0% +okay so what do we know about each of + + + align:start position:0% +okay so what do we know about each of +these values + + align:start position:0% + + + + align:start position:0% + +let's start with this one can anybody + + align:start position:0% +let's start with this one can anybody + + + align:start position:0% +let's start with this one can anybody +bound + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +yeah yeah it's at least X if you + + align:start position:0% +yeah yeah it's at least X if you + + + align:start position:0% +yeah yeah it's at least X if you +conditioned on R being at least X right + + align:start position:0% +conditioned on R being at least X right + + + align:start position:0% +conditioned on R being at least X right +the expectation of R is is also going to + + align:start position:0% +the expectation of R is is also going to + + + align:start position:0% +the expectation of R is is also going to +be at least X right every outcome is at + + align:start position:0% +be at least X right every outcome is at + + + align:start position:0% +be at least X right every outcome is at +least + + align:start position:0% +least + + + align:start position:0% +least +X okay + + align:start position:0% +X okay + + + align:start position:0% +X okay +so this is going to be at least x + + align:start position:0% +so this is going to be at least x + + + align:start position:0% +so this is going to be at least x +times well this is the probability that + + align:start position:0% +times well this is the probability that + + + align:start position:0% +times well this is the probability that +that we're looking for so let's just + + align:start position:0% +that we're looking for so let's just + + + align:start position:0% +that we're looking for so let's just +write it out as it + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +okay now what about the bottom + + align:start position:0% + + + + align:start position:0% + +line what do we know about this + + align:start position:0% +line what do we know about this + + + align:start position:0% +line what do we know about this +expectation + + align:start position:0% + + + + align:start position:0% + +yeah is it one minus the expectation uh + + align:start position:0% +yeah is it one minus the expectation uh + + + align:start position:0% +yeah is it one minus the expectation uh +of the other one uh no so the the + + align:start position:0% +of the other one uh no so the the + + + align:start position:0% +of the other one uh no so the the +probability is one minus the uh the + + align:start position:0% +probability is one minus the uh the + + + align:start position:0% +probability is one minus the uh the +other probability uh the expectation + + align:start position:0% +other probability uh the expectation + + + align:start position:0% +other probability uh the expectation +does not work like that though + + align:start position:0% +does not work like that though + + + align:start position:0% +does not work like that though +yeah it is at most X that is true um + + align:start position:0% +yeah it is at most X that is true um + + + align:start position:0% +yeah it is at most X that is true um +we're actually looking for a lower bound + + align:start position:0% +we're actually looking for a lower bound + + + align:start position:0% +we're actually looking for a lower bound +though + + align:start position:0% + + + + align:start position:0% + +yeah so at least Z + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay right we know that that R is always + + align:start position:0% +okay right we know that that R is always + + + align:start position:0% +okay right we know that that R is always +non + + align:start position:0% +non + + + align:start position:0% +non +negative so you know conditioning on + + align:start position:0% +negative so you know conditioning on + + + align:start position:0% +negative so you know conditioning on +anything R is still always going to be + + align:start position:0% +anything R is still always going to be + + + align:start position:0% +anything R is still always going to be +non- negative so it's expectation has to + + align:start position:0% +non- negative so it's expectation has to + + + align:start position:0% +non- negative so it's expectation has to +be non- + + align:start position:0% +be non- + + + align:start position:0% +be non- +negative + + align:start position:0% + + + + align:start position:0% + +okay so we we can drop this this is just + + align:start position:0% +okay so we we can drop this this is just + + + align:start position:0% +okay so we we can drop this this is just +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +zero now we've got the expectation of + + align:start position:0% + + + + align:start position:0% + +R is at + + align:start position:0% +R is at + + + align:start position:0% +R is at +least x times the probability that R is + + align:start position:0% +least x times the probability that R is + + + align:start position:0% +least x times the probability that R is +at least + + align:start position:0% +at least + + + align:start position:0% +at least +X + + align:start position:0% + + + + align:start position:0% + +okay now we can just move this x to the + + align:start position:0% +okay now we can just move this x to the + + + align:start position:0% +okay now we can just move this x to the +other side + + align:start position:0% + + + + align:start position:0% + +assuming X is not negative if x is + + align:start position:0% +assuming X is not negative if x is + + + align:start position:0% +assuming X is not negative if x is +negative then it's a it's a very silly + + align:start position:0% +negative then it's a it's a very silly + + + align:start position:0% +negative then it's a it's a very silly +question so you know or sorry assuming X + + align:start position:0% +question so you know or sorry assuming X + + + align:start position:0% +question so you know or sorry assuming X +is + + align:start position:0% +is + + + align:start position:0% +is +positive okay are people happy with this + + align:start position:0% + + + + align:start position:0% + +proof do anybody have any questions + + align:start position:0% + + + + align:start position:0% + +so another form of marov which you uh + + align:start position:0% +so another form of marov which you uh + + + align:start position:0% +so another form of marov which you uh +May often encounter is the + + align:start position:0% + + + + align:start position:0% + +following so the probability that R is + + align:start position:0% +following so the probability that R is + + + align:start position:0% +following so the probability that R is +at least uh C c times its + + align:start position:0% + + + + align:start position:0% + +expectation is at most one over + + align:start position:0% +expectation is at most one over + + + align:start position:0% +expectation is at most one over +C + + align:start position:0% + + + + align:start position:0% + +okay for any positive + + align:start position:0% + + + + align:start position:0% + +C so essentially equivalent statement + + align:start position:0% +C so essentially equivalent statement + + + align:start position:0% +C so essentially equivalent statement +just you know you might sometimes see it + + align:start position:0% +just you know you might sometimes see it + + + align:start position:0% +just you know you might sometimes see it +in this form + + align:start position:0% +in this form + + + align:start position:0% +in this form +instead + + align:start position:0% +instead + + + align:start position:0% +instead +okay so let's take a look at a couple + + align:start position:0% +okay so let's take a look at a couple + + + align:start position:0% +okay so let's take a look at a couple +more examples + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +suppose or is uh the test score of a + + align:start position:0% +suppose or is uh the test score of a + + + align:start position:0% +suppose or is uh the test score of a +randomly chosen student instead of the + + align:start position:0% +randomly chosen student instead of the + + + align:start position:0% +randomly chosen student instead of the +road that they're sitting in + + align:start position:0% + + + + align:start position:0% + +okay and uh suppose that these are all + + align:start position:0% +okay and uh suppose that these are all + + + align:start position:0% +okay and uh suppose that these are all +in the range uh + + align:start position:0% +in the range uh + + + align:start position:0% +in the range uh +say 30 to + + align:start position:0% + + + + align:start position:0% + +100% okay + + align:start position:0% + + + + align:start position:0% + +uh can we use + + align:start position:0% + + + + align:start position:0% + +marov to bound the + + align:start position:0% + + + + align:start position:0% + +probability that R is at least say + + align:start position:0% + + + + align:start position:0% + +90% how might we do + + align:start position:0% + + + + align:start position:0% + +that h + + align:start position:0% +that h + + + align:start position:0% +that h +sorry I completely forgot to give you + + align:start position:0% +sorry I completely forgot to give you + + + align:start position:0% +sorry I completely forgot to give you +the expectation the answer is + + align:start position:0% +the expectation the answer is + + + align:start position:0% +the expectation the answer is +no + + align:start position:0% + + + + align:start position:0% + +uh okay now can you do + + align:start position:0% +uh okay now can you do + + + align:start position:0% +uh okay now can you do +it hopefully it's a little bit easier + + align:start position:0% +it hopefully it's a little bit easier + + + align:start position:0% +it hopefully it's a little bit easier +now + + align:start position:0% + + + + align:start position:0% + +mhm yeah so find the value of C such + + align:start position:0% +mhm yeah so find the value of C such + + + align:start position:0% +mhm yeah so find the value of C such +that c c * 75 is + + align:start position:0% +that c c * 75 is + + + align:start position:0% +that c c * 75 is +90 uh + + align:start position:0% +90 uh + + + align:start position:0% +90 uh +so I guess 75 over or 90 divided + + align:start position:0% +so I guess 75 over or 90 divided + + + align:start position:0% +so I guess 75 over or 90 divided +75 that's what's + + align:start position:0% + + + + align:start position:0% + +1.2 is that right + + align:start position:0% +1.2 is that right + + + align:start position:0% +1.2 is that right +uh 75 is 5 by 15 right 90 is 6 by 15 + + align:start position:0% +uh 75 is 5 by 15 right 90 is 6 by 15 + + + align:start position:0% +uh 75 is 5 by 15 right 90 is 6 by 15 +okay nice arithmetic score okay so then + + align:start position:0% +okay nice arithmetic score okay so then + + + align:start position:0% +okay nice arithmetic score okay so then +uh using + + align:start position:0% +uh using + + + align:start position:0% +uh using +uh this formulation here we + + align:start position:0% +uh this formulation here we + + + align:start position:0% +uh this formulation here we +have the + + align:start position:0% +have the + + + align:start position:0% +have the +probability that R is at least uh you + + align:start position:0% +probability that R is at least uh you + + + align:start position:0% +probability that R is at least uh you +know 1.2 times + + align:start position:0% +know 1.2 times + + + align:start position:0% +know 1.2 times +uh expectation of r + + align:start position:0% + + + + align:start position:0% + +is at most 1 divid + + align:start position:0% +is at most 1 divid + + + align:start position:0% +is at most 1 divid +1.2 okay so this is going to be you know + + align:start position:0% +1.2 okay so this is going to be you know + + + align:start position:0% +1.2 okay so this is going to be you know +something like + + align:start position:0% + + + + align:start position:0% + +83% + + align:start position:0% + + + + align:start position:0% + +okay people reasonably happy with + + align:start position:0% +okay people reasonably happy with + + + align:start position:0% +okay people reasonably happy with +that + + align:start position:0% + + + + align:start position:0% + +yeah oh the question is um can we + + align:start position:0% +yeah oh the question is um can we + + + align:start position:0% +yeah oh the question is um can we +explain the difference between these two + + align:start position:0% +explain the difference between these two + + + align:start position:0% +explain the difference between these two +formulations + + align:start position:0% + + + + align:start position:0% + +sorry uh so yeah essentially there is no + + align:start position:0% +sorry uh so yeah essentially there is no + + + align:start position:0% +sorry uh so yeah essentially there is no +difference like there're just uh you + + align:start position:0% +difference like there're just uh you + + + align:start position:0% +difference like there're just uh you +know different ways of of thinking about + + align:start position:0% +know different ways of of thinking about + + + align:start position:0% +know different ways of of thinking about +uh thinking about the bound you can + + align:start position:0% +uh thinking about the bound you can + + + align:start position:0% +uh thinking about the bound you can +either think about bounding it in terms + + align:start position:0% +either think about bounding it in terms + + + align:start position:0% +either think about bounding it in terms +of some you know absolute threshold or + + align:start position:0% +of some you know absolute threshold or + + + align:start position:0% +of some you know absolute threshold or +you can think about it as like in terms + + align:start position:0% +you can think about it as like in terms + + + align:start position:0% +you can think about it as like in terms +of some you know relative threshold like + + align:start position:0% +of some you know relative threshold like + + + align:start position:0% +of some you know relative threshold like +you know multiply the uh the expectation + + align:start position:0% +you know multiply the uh the expectation + + + align:start position:0% +you know multiply the uh the expectation +by some by some scaling Factor okay so + + align:start position:0% +by some by some scaling Factor okay so + + + align:start position:0% +by some by some scaling Factor okay so +you know depending on on which of them + + align:start position:0% +you know depending on on which of them + + + align:start position:0% +you know depending on on which of them +feels more natural to you uh we could + + align:start position:0% +feels more natural to you uh we could + + + align:start position:0% +feels more natural to you uh we could +also used the first formulation to say + + align:start position:0% +also used the first formulation to say + + + align:start position:0% +also used the first formulation to say +you know + + align:start position:0% +you know + + + align:start position:0% +you know +probability that R is greater than + + align:start position:0% +probability that R is greater than + + + align:start position:0% +probability that R is greater than +90 greater than or equal to is going to + + align:start position:0% +90 greater than or equal to is going to + + + align:start position:0% +90 greater than or equal to is going to +be at most uh 75 over + + align:start position:0% +be at most uh 75 over + + + align:start position:0% +be at most uh 75 over +90 which you know same thing + + align:start position:0% +90 which you know same thing + + + align:start position:0% +90 which you know same thing +83% okay so either of them Works they + + align:start position:0% +83% okay so either of them Works they + + + align:start position:0% +83% okay so either of them Works they +both give the same answer they're + + align:start position:0% +both give the same answer they're + + + align:start position:0% +both give the same answer they're +equivalent formulations it's just you + + align:start position:0% +equivalent formulations it's just you + + + align:start position:0% +equivalent formulations it's just you +know whichever one you find easier to + + align:start position:0% +know whichever one you find easier to + + + align:start position:0% +know whichever one you find easier to +think about question + + align:start position:0% + + + + align:start position:0% + +yes exactly okay so the question was uh + + align:start position:0% +yes exactly okay so the question was uh + + + align:start position:0% +yes exactly okay so the question was uh +we don't just have a non- negative + + align:start position:0% +we don't just have a non- negative + + + align:start position:0% +we don't just have a non- negative +random variable R right we we've + + align:start position:0% +random variable R right we we've + + + align:start position:0% +random variable R right we we've +actually got an even stronger bound R is + + align:start position:0% +actually got an even stronger bound R is + + + align:start position:0% +actually got an even stronger bound R is +at least 30 not just at least zero okay + + align:start position:0% +at least 30 not just at least zero okay + + + align:start position:0% +at least 30 not just at least zero okay +so can we leverage that to get an even + + align:start position:0% +so can we leverage that to get an even + + + align:start position:0% +so can we leverage that to get an even +stronger + + align:start position:0% +stronger + + + align:start position:0% +stronger +bound okay so how could we do + + align:start position:0% + + + + align:start position:0% + +that well let's try def finding + + align:start position:0% +that well let's try def finding + + + align:start position:0% +that well let's try def finding +different random + + align:start position:0% + + + + align:start position:0% + +variable + + align:start position:0% +variable + + + align:start position:0% +variable +so let R Prime be Rus + + align:start position:0% +so let R Prime be Rus + + + align:start position:0% +so let R Prime be Rus + + align:start position:0% + + + + align:start position:0% + +okay so this is another random variable + + align:start position:0% +okay so this is another random variable + + + align:start position:0% +okay so this is another random variable +right we're just going to take our + + align:start position:0% +right we're just going to take our + + + align:start position:0% +right we're just going to take our +original R we're going to subtract 30 um + + align:start position:0% +original R we're going to subtract 30 um + + + align:start position:0% +original R we're going to subtract 30 um +we're not going to do this to people's + + align:start position:0% +we're not going to do this to people's + + + align:start position:0% +we're not going to do this to people's +exam scores in reality don't don't worry + + align:start position:0% +exam scores in reality don't don't worry + + + align:start position:0% +exam scores in reality don't don't worry +uh but that this makes the the minimum + + align:start position:0% +uh but that this makes the the minimum + + + align:start position:0% +uh but that this makes the the minimum +exam score zero + + align:start position:0% +exam score zero + + + align:start position:0% +exam score zero +right so the hope is that you know now + + align:start position:0% +right so the hope is that you know now + + + align:start position:0% +right so the hope is that you know now +we're kind of satisfying the condition + + align:start position:0% +we're kind of satisfying the condition + + + align:start position:0% +we're kind of satisfying the condition +to to markov's uh inequality like more + + align:start position:0% +to to markov's uh inequality like more + + + align:start position:0% +to to markov's uh inequality like more +tightly so hopefully marov will give us + + align:start position:0% +tightly so hopefully marov will give us + + + align:start position:0% +tightly so hopefully marov will give us +a tighter bound okay so what bound does + + align:start position:0% +a tighter bound okay so what bound does + + + align:start position:0% +a tighter bound okay so what bound does +it give us now what is the + + align:start position:0% +it give us now what is the + + + align:start position:0% +it give us now what is the +probability that R is at least 90 + + align:start position:0% + + + + align:start position:0% + +well what is that in terms of R Prime + + align:start position:0% +well what is that in terms of R Prime + + + align:start position:0% +well what is that in terms of R Prime +what is that + + align:start position:0% + + + + align:start position:0% + +event + + align:start position:0% +event + + + align:start position:0% +event +yeah yeah so this is the same event and + + align:start position:0% +yeah yeah so this is the same event and + + + align:start position:0% +yeah yeah so this is the same event and +so the same + + align:start position:0% +so the same + + + align:start position:0% +so the same +probability that R Prime is at least + + align:start position:0% + + + + align:start position:0% + +60 now what happens when we apply Markov + + align:start position:0% +60 now what happens when we apply Markov + + + align:start position:0% +60 now what happens when we apply Markov +to + + align:start position:0% + + + + align:start position:0% + +this well this is going to be at + + align:start position:0% +this well this is going to be at + + + align:start position:0% +this well this is going to be at +most + + align:start position:0% + + + + align:start position:0% + +right the expectation of RP Prime + + align:start position:0% +right the expectation of RP Prime + + + align:start position:0% +right the expectation of RP Prime +ID + + align:start position:0% +ID + + + align:start position:0% +ID +60 what is the expectation of R + + align:start position:0% + + + + align:start position:0% + +Prime yeah 45 + + align:start position:0% +Prime yeah 45 + + + align:start position:0% +Prime yeah 45 +yeah so this is going to be the + + align:start position:0% +yeah so this is going to be the + + + align:start position:0% +yeah so this is going to be the +expectation of R uh minus + + align:start position:0% +expectation of R uh minus + + + align:start position:0% +expectation of R uh minus +30 / 60 which is the expectation so + + align:start position:0% +30 / 60 which is the expectation so + + + align:start position:0% +30 / 60 which is the expectation so +linearity of expectation we can pull + + align:start position:0% +linearity of expectation we can pull + + + align:start position:0% +linearity of expectation we can pull +this or like we can you know split this + + align:start position:0% +this or like we can you know split this + + + align:start position:0% +this or like we can you know split this +into two expectations so this is the + + align:start position:0% +into two expectations so this is the + + + align:start position:0% +into two expectations so this is the +expectation of + + align:start position:0% +expectation of + + + align:start position:0% +expectation of +R minus the expectation of 30 there's + + align:start position:0% +R minus the expectation of 30 there's + + + align:start position:0% +R minus the expectation of 30 there's +you know not really any Randomness + + align:start position:0% +you know not really any Randomness + + + align:start position:0% +you know not really any Randomness +involved there it's just + + align:start position:0% +involved there it's just + + + align:start position:0% +involved there it's just +30 over 60 right so this is + + align:start position:0% +30 over 60 right so this is + + + align:start position:0% +30 over 60 right so this is +45 over 60 + + align:start position:0% +45 over 60 + + + align:start position:0% +45 over 60 +okay does that make sense to + + align:start position:0% + + + + align:start position:0% + +everybody so now instead of this bound + + align:start position:0% +everybody so now instead of this bound + + + align:start position:0% +everybody so now instead of this bound +of uh you know it's it's at most 83% now + + align:start position:0% +of uh you know it's it's at most 83% now + + + align:start position:0% +of uh you know it's it's at most 83% now +we've got the better bound it's at most + + align:start position:0% + + + + align:start position:0% + +75% + + align:start position:0% +75% + + + align:start position:0% +75% +okay so by shifting our random variable + + align:start position:0% +okay so by shifting our random variable + + + align:start position:0% +okay so by shifting our random variable +we've managed to get a tighter bound + + align:start position:0% + + + + align:start position:0% + +okay what + + align:start position:0% + + + + align:start position:0% + +about the probability that R is at most + + align:start position:0% +about the probability that R is at most + + + align:start position:0% +about the probability that R is at most + + align:start position:0% + + + + align:start position:0% + +yeah mhm + + align:start position:0% + + + + align:start position:0% + +so that that's kind of what we're doing + + align:start position:0% +so that that's kind of what we're doing + + + align:start position:0% +so that that's kind of what we're doing +right the the the question was uh in the + + align:start position:0% +right the the the question was uh in the + + + align:start position:0% +right the the the question was uh in the +proof of Markov right we're assuming + + align:start position:0% +proof of Markov right we're assuming + + + align:start position:0% +proof of Markov right we're assuming +that the lower bound is zero uh here + + align:start position:0% +that the lower bound is zero uh here + + + align:start position:0% +that the lower bound is zero uh here +we've got a lower bound of 30 instead so + + align:start position:0% +we've got a lower bound of 30 instead so + + + align:start position:0% +we've got a lower bound of 30 instead so +do we need to do something more + + align:start position:0% +do we need to do something more + + + align:start position:0% +do we need to do something more +complicated the answer is no we don't + + align:start position:0% +complicated the answer is no we don't + + + align:start position:0% +complicated the answer is no we don't +have to but if we do it gives us a + + align:start position:0% +have to but if we do it gives us a + + + align:start position:0% +have to but if we do it gives us a +stronger result so that's what we've + + align:start position:0% +stronger result so that's what we've + + + align:start position:0% +stronger result so that's what we've +done here but we don't have to do it + + align:start position:0% +done here but we don't have to do it + + + align:start position:0% +done here but we don't have to do it +right because zero is still a valid + + align:start position:0% +right because zero is still a valid + + + align:start position:0% +right because zero is still a valid +lower bound right we could still say we + + align:start position:0% +lower bound right we could still say we + + + align:start position:0% +lower bound right we could still say we +could say that the co- domain of R is 0 + + align:start position:0% +could say that the co- domain of R is 0 + + + align:start position:0% +could say that the co- domain of R is 0 +to 100 instead of 30 to 100 even even if + + align:start position:0% +to 100 instead of 30 to 100 even even if + + + align:start position:0% +to 100 instead of 30 to 100 even even if +the range stays + + align:start position:0% +the range stays + + + align:start position:0% +the range stays +unchanged okay so it's still a non- + + align:start position:0% +unchanged okay so it's still a non- + + + align:start position:0% +unchanged okay so it's still a non- +negative random variable so we're still + + align:start position:0% +negative random variable so we're still + + + align:start position:0% +negative random variable so we're still +allowed to apply marov to it it's just + + align:start position:0% +allowed to apply marov to it it's just + + + align:start position:0% +allowed to apply marov to it it's just +that you know doing it on r instead of R + + align:start position:0% +that you know doing it on r instead of R + + + align:start position:0% +that you know doing it on r instead of R +Prime gives us a weaker + + align:start position:0% +Prime gives us a weaker + + + align:start position:0% +Prime gives us a weaker +result okay does that make sense to + + align:start position:0% +result okay does that make sense to + + + align:start position:0% +result okay does that make sense to +everybody another question + + align:start position:0% + + + + align:start position:0% + +uh so the question is what do I mean by + + align:start position:0% +uh so the question is what do I mean by + + + align:start position:0% +uh so the question is what do I mean by +by a tighter bound when when we shift R + + align:start position:0% +by a tighter bound when when we shift R + + + align:start position:0% +by a tighter bound when when we shift R +uh so tighter in the sense that it is + + align:start position:0% +uh so tighter in the sense that it is + + + align:start position:0% +uh so tighter in the sense that it is +stronger right so uh r at least 30 + + align:start position:0% +stronger right so uh r at least 30 + + + align:start position:0% +stronger right so uh r at least 30 +implies that R is at least zero so r r + + align:start position:0% +implies that R is at least zero so r r + + + align:start position:0% +implies that R is at least zero so r r +at least 30 is a stronger condition than + + align:start position:0% +at least 30 is a stronger condition than + + + align:start position:0% +at least 30 is a stronger condition than +than r at least zero + + align:start position:0% +than r at least zero + + + align:start position:0% +than r at least zero +okay so that that's what I mean by + + align:start position:0% + + + + align:start position:0% + +tighter uh so the the difference right + + align:start position:0% +tighter uh so the the difference right + + + align:start position:0% +tighter uh so the the difference right +is how we're applying marov right uh we + + align:start position:0% +is how we're applying marov right uh we + + + align:start position:0% +is how we're applying marov right uh we +are in the first case we're applying + + align:start position:0% +are in the first case we're applying + + + align:start position:0% +are in the first case we're applying +marov to R directly in the second case + + align:start position:0% +marov to R directly in the second case + + + align:start position:0% +marov to R directly in the second case +we are creating a new random + + align:start position:0% +we are creating a new random + + + align:start position:0% +we are creating a new random +variable uh and we're applying marov to + + align:start position:0% +variable uh and we're applying marov to + + + align:start position:0% +variable uh and we're applying marov to +that and you know because uh you know + + align:start position:0% +that and you know because uh you know + + + align:start position:0% +that and you know because uh you know +we've got a a stronger condition like + + align:start position:0% +we've got a a stronger condition like + + + align:start position:0% +we've got a a stronger condition like +the the marov markov's um what do you + + align:start position:0% +the the marov markov's um what do you + + + align:start position:0% +the the marov markov's um what do you +call it precondition is is tight + + align:start position:0% +call it precondition is is tight + + + align:start position:0% +call it precondition is is tight +now uh we can get a a stronger + + align:start position:0% + + + + align:start position:0% + +result okay + + align:start position:0% + + + + align:start position:0% + +yeah uh could it go higher than 83% + + align:start position:0% + + + + align:start position:0% + +uh okay so we will get to that in a + + align:start position:0% +uh okay so we will get to that in a + + + align:start position:0% +uh okay so we will get to that in a +moment the the question is you know if + + align:start position:0% +moment the the question is you know if + + + align:start position:0% +moment the the question is you know if +we're in a different + + align:start position:0% +we're in a different + + + align:start position:0% +we're in a different +situation uh could shifting it give us + + align:start position:0% +situation uh could shifting it give us + + + align:start position:0% +situation uh could shifting it give us +something that's higher than + + align:start position:0% +something that's higher than + + + align:start position:0% +something that's higher than +83% and the answer is yes + + align:start position:0% +83% and the answer is yes + + + align:start position:0% +83% and the answer is yes +is right in the case where we've applied + + align:start position:0% +is right in the case where we've applied + + + align:start position:0% +is right in the case where we've applied +Markov incorrectly the first time then + + align:start position:0% +Markov incorrectly the first time then + + + align:start position:0% +Markov incorrectly the first time then +yes but uh you know if we've applied + + align:start position:0% +yes but uh you know if we've applied + + + align:start position:0% +yes but uh you know if we've applied +Markov correctly then uh you know the + + align:start position:0% +Markov correctly then uh you know the + + + align:start position:0% +Markov correctly then uh you know the +first is a valid bound right + + align:start position:0% +first is a valid bound right + + + align:start position:0% +first is a valid bound right +right so you know we we could in + + align:start position:0% +right so you know we we could in + + + align:start position:0% +right so you know we we could in +principle improve it but uh you know + + align:start position:0% +principle improve it but uh you know + + + align:start position:0% +principle improve it but uh you know +we're not going to do any worse by you + + align:start position:0% +we're not going to do any worse by you + + + align:start position:0% +we're not going to do any worse by you +know imposing tighter + + align:start position:0% +know imposing tighter + + + align:start position:0% +know imposing tighter +conditions does that like at least kind + + align:start position:0% +conditions does that like at least kind + + + align:start position:0% +conditions does that like at least kind +of intuitively make sense I'll give you + + align:start position:0% +of intuitively make sense I'll give you + + + align:start position:0% +of intuitively make sense I'll give you +a more complete answer in a + + align:start position:0% + + + + align:start position:0% + +moment any more questions about this + + align:start position:0% +moment any more questions about this + + + align:start position:0% +moment any more questions about this +before we move on to the next + + align:start position:0% +before we move on to the next + + + align:start position:0% +before we move on to the next +example + + align:start position:0% + + + + align:start position:0% + +yeah yes + + align:start position:0% +yeah yes + + + align:start position:0% +yeah yes +it is a good thing uh so the the + + align:start position:0% +it is a good thing uh so the the + + + align:start position:0% +it is a good thing uh so the the +question is is it a good thing that the + + align:start position:0% +question is is it a good thing that the + + + align:start position:0% +question is is it a good thing that the +75% is smaller than the + + align:start position:0% +75% is smaller than the + + + align:start position:0% +75% is smaller than the +83% uh yes we are looking for an upper + + align:start position:0% +83% uh yes we are looking for an upper + + + align:start position:0% +83% uh yes we are looking for an upper +bound on the probability right so a + + align:start position:0% +bound on the probability right so a + + + align:start position:0% +bound on the probability right so a +smaller upper bound is a stronger + + align:start position:0% +smaller upper bound is a stronger + + + align:start position:0% +smaller upper bound is a stronger +condition so that's that's better it's + + align:start position:0% +condition so that's that's better it's + + + align:start position:0% +condition so that's that's better it's +um it's a it's a stronger bound you want + + align:start position:0% +um it's a it's a stronger bound you want + + + align:start position:0% +um it's a it's a stronger bound you want +a smaller upper or AER so that they're + + align:start position:0% +a smaller upper or AER so that they're + + + align:start position:0% +a smaller upper or AER so that they're +the same smaller upper bounds are + + align:start position:0% +the same smaller upper bounds are + + + align:start position:0% +the same smaller upper bounds are +stronger upper bounds + + align:start position:0% + + + + align:start position:0% + +yeah so like less than or equal to 83% + + align:start position:0% +yeah so like less than or equal to 83% + + + align:start position:0% +yeah so like less than or equal to 83% +implies less than or equal to uh sorry + + align:start position:0% +implies less than or equal to uh sorry + + + align:start position:0% +implies less than or equal to uh sorry +less than or equal to 75% implies less + + align:start position:0% +less than or equal to 75% implies less + + + align:start position:0% +less than or equal to 75% implies less +than or equal to to 83% so 75 is is + + align:start position:0% + + + + align:start position:0% + +stronger + + align:start position:0% + + + + align:start position:0% + +okay okay have people had enough time to + + align:start position:0% +okay okay have people had enough time to + + + align:start position:0% +okay okay have people had enough time to +think about the probability that R is at + + align:start position:0% +think about the probability that R is at + + + align:start position:0% +think about the probability that R is at +most + + align:start position:0% + + + + align:start position:0% + +65 how might we use marov to figure this + + align:start position:0% +65 how might we use marov to figure this + + + align:start position:0% +65 how might we use marov to figure this +one out + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +okay so R greater than or equal to 66 so + + align:start position:0% +okay so R greater than or equal to 66 so + + + align:start position:0% +okay so R greater than or equal to 66 so +if we assume integer + + align:start position:0% +if we assume integer + + + align:start position:0% +if we assume integer +scores + + align:start position:0% +scores + + + align:start position:0% +scores +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um and what does marov tell us about + + align:start position:0% +um and what does marov tell us about + + + align:start position:0% +um and what does marov tell us about +this + + align:start position:0% + + + + align:start position:0% + +well the probability that R + + align:start position:0% +well the probability that R + + + align:start position:0% +well the probability that R +is at least + + align:start position:0% +is at least + + + align:start position:0% +is at least +66 right is going to be at most 75 over + + align:start position:0% +66 right is going to be at most 75 over + + + align:start position:0% +66 right is going to be at most 75 over + + align:start position:0% + + + align:start position:0% +which is bigger than + + align:start position:0% +which is bigger than + + + align:start position:0% +which is bigger than +one so applying marov does not tell us + + align:start position:0% +one so applying marov does not tell us + + + align:start position:0% +one so applying marov does not tell us +anything useful it tells us that this is + + align:start position:0% +anything useful it tells us that this is + + + align:start position:0% +anything useful it tells us that this is +a probability that's that's bounded by + + align:start position:0% +a probability that's that's bounded by + + + align:start position:0% +a probability that's that's bounded by +one which we already + + align:start position:0% + + + + align:start position:0% + +knew so it is a good idea it's not quite + + align:start position:0% +knew so it is a good idea it's not quite + + + align:start position:0% +knew so it is a good idea it's not quite +what we want here + + align:start position:0% + + + + align:start position:0% + +so what if instead of uh you know + + align:start position:0% +so what if instead of uh you know + + + align:start position:0% +so what if instead of uh you know +fiddling with the event we fiddle with r + + align:start position:0% +fiddling with the event we fiddle with r + + + align:start position:0% +fiddling with the event we fiddle with r +again kind of similar to what we did + + align:start position:0% + + + + align:start position:0% + +before + + align:start position:0% + + + + align:start position:0% + +yeah yeah exactly so we're going to flip + + align:start position:0% +yeah yeah exactly so we're going to flip + + + align:start position:0% +yeah yeah exactly so we're going to flip +R right so we're going to define a new + + align:start position:0% +R right so we're going to define a new + + + align:start position:0% +R right so we're going to define a new +random variable let's say s equals + + align:start position:0% +random variable let's say s equals + + + align:start position:0% +random variable let's say s equals +100 minus r + + align:start position:0% + + + + align:start position:0% + +okay so now the probability that R is at + + align:start position:0% +okay so now the probability that R is at + + + align:start position:0% +okay so now the probability that R is at +most + + align:start position:0% +most + + + align:start position:0% +most +65 is the probability that s is at least + + align:start position:0% +65 is the probability that s is at least + + + align:start position:0% +65 is the probability that s is at least +what 100 minus 65 + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +okay can we apply Markov to that + + align:start position:0% + + + + align:start position:0% + +I'm seeing some nods does anybody want + + align:start position:0% +I'm seeing some nods does anybody want + + + align:start position:0% +I'm seeing some nods does anybody want +to do that and spare me the trouble of + + align:start position:0% +to do that and spare me the trouble of + + + align:start position:0% +to do that and spare me the trouble of +doing + + align:start position:0% + + + + align:start position:0% + +arithmetic nobody sadness okay + + align:start position:0% +arithmetic nobody sadness okay + + + align:start position:0% +arithmetic nobody sadness okay +uh well what does Markov say well it's + + align:start position:0% +uh well what does Markov say well it's + + + align:start position:0% +uh well what does Markov say well it's +at most the expectation of + + align:start position:0% +at most the expectation of + + + align:start position:0% +at most the expectation of +X oh sorry + + align:start position:0% +X oh sorry + + + align:start position:0% +X oh sorry +s divided by + + align:start position:0% + + + + align:start position:0% + +35 okay what is the expectation of s + + align:start position:0% +35 okay what is the expectation of s + + + align:start position:0% +35 okay what is the expectation of s +well using linearity in the same way + + align:start position:0% +well using linearity in the same way + + + align:start position:0% +well using linearity in the same way +that we did a moment + + align:start position:0% +that we did a moment + + + align:start position:0% +that we did a moment +ago this is going to be equal to uh what + + align:start position:0% +ago this is going to be equal to uh what + + + align:start position:0% +ago this is going to be equal to uh what +100 minus the expectation of R which is + + align:start position:0% +100 minus the expectation of R which is + + + align:start position:0% +100 minus the expectation of R which is +75 over 35 so that's 25 over 35 this is + + align:start position:0% + + + + align:start position:0% + +57s + + align:start position:0% + + + + align:start position:0% + +okay so does does that make sense to + + align:start position:0% +okay so does does that make sense to + + + align:start position:0% +okay so does does that make sense to +everybody there is at most a 57th chance + + align:start position:0% +everybody there is at most a 57th chance + + + align:start position:0% +everybody there is at most a 57th chance +that you uh did worse than + + align:start position:0% +that you uh did worse than + + + align:start position:0% +that you uh did worse than + + align:start position:0% + + + + align:start position:0% + +okay now perhaps not terribly realistic + + align:start position:0% +okay now perhaps not terribly realistic + + + align:start position:0% +okay now perhaps not terribly realistic +in terms of exam scores but uh you know + + align:start position:0% +in terms of exam scores but uh you know + + + align:start position:0% +in terms of exam scores but uh you know +what if say some of the students did so + + align:start position:0% +what if say some of the students did so + + + align:start position:0% +what if say some of the students did so +badly that they got scores that are less + + align:start position:0% +badly that they got scores that are less + + + align:start position:0% +badly that they got scores that are less +than zero like maybe you've got uh you + + align:start position:0% +than zero like maybe you've got uh you + + + align:start position:0% +than zero like maybe you've got uh you +know R is in the range you know minus 30 + + align:start position:0% +know R is in the range you know minus 30 + + + align:start position:0% +know R is in the range you know minus 30 +to + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +okay same deal expectation of r + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +75 uh question or + + align:start position:0% +75 uh question or + + + align:start position:0% +75 uh question or +um sorry um okay so what can we say + + align:start position:0% +um sorry um okay so what can we say + + + align:start position:0% +um sorry um okay so what can we say +about the probability that R uh is at + + align:start position:0% +about the probability that R uh is at + + + align:start position:0% +about the probability that R uh is at +least uh say + + align:start position:0% + + + + align:start position:0% + +90 mhm + + align:start position:0% + + + + align:start position:0% + +yeah exactly so the observation was + + align:start position:0% +yeah exactly so the observation was + + + align:start position:0% +yeah exactly so the observation was +right if we try to apply marov to this + + align:start position:0% +right if we try to apply marov to this + + + align:start position:0% +right if we try to apply marov to this +maybe I should call it a different call + + align:start position:0% +maybe I should call it a different call + + + align:start position:0% +maybe I should call it a different call +it something different let's call it + + align:start position:0% + + + + align:start position:0% + +t so if we try to apply Markov to + + align:start position:0% + + + + align:start position:0% + +T right it's going to be the same thing + + align:start position:0% +T right it's going to be the same thing + + + align:start position:0% +T right it's going to be the same thing +as as when we applied Markov to R before + + align:start position:0% +as as when we applied Markov to R before + + + align:start position:0% +as as when we applied Markov to R before +it'll give us a bound of of 83% the + + align:start position:0% +it'll give us a bound of of 83% the + + + align:start position:0% +it'll give us a bound of of 83% the +problem is that that's wrong that does + + align:start position:0% +problem is that that's wrong that does + + + align:start position:0% +problem is that that's wrong that does +it t does not satisfy the precondition + + align:start position:0% +it t does not satisfy the precondition + + + align:start position:0% +it t does not satisfy the precondition +for + + align:start position:0% +for + + + align:start position:0% +for +Markov okay so what we want to do + + align:start position:0% +Markov okay so what we want to do + + + align:start position:0% +Markov okay so what we want to do +instead is + + align:start position:0% +instead is + + + align:start position:0% +instead is +toine T Prime = t + + + align:start position:0% +toine T Prime = t + + + + align:start position:0% +toine T Prime = t + + + align:start position:0% + + + align:start position:0% +okay and now if we apply Markov to T + + align:start position:0% +okay and now if we apply Markov to T + + + align:start position:0% +okay and now if we apply Markov to T +Prime what do we get so the probability + + align:start position:0% +Prime what do we get so the probability + + + align:start position:0% +Prime what do we get so the probability +that uh T is greater than + + align:start position:0% +that uh T is greater than + + + align:start position:0% +that uh T is greater than +90 is the probability + + align:start position:0% +90 is the probability + + + align:start position:0% +90 is the probability +that t Prime is at least + + align:start position:0% +that t Prime is at least + + + align:start position:0% +that t Prime is at least + + align:start position:0% + + + align:start position:0% +okay and by Mark of this is going to be + + align:start position:0% +okay and by Mark of this is going to be + + + align:start position:0% +okay and by Mark of this is going to be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +expectation of T + + align:start position:0% +expectation of T + + + align:start position:0% +expectation of T +Prime over + + align:start position:0% +Prime over + + + align:start position:0% +Prime over +120 okay and you know same deal as + + align:start position:0% +120 okay and you know same deal as + + + align:start position:0% +120 okay and you know same deal as +before linearity here gives us uh 75 + + + align:start position:0% +before linearity here gives us uh 75 + + + + align:start position:0% +before linearity here gives us uh 75 + +30 over + + align:start position:0% +30 over + + + align:start position:0% +30 over +120 105 over 120 that's + + align:start position:0% + + + + align:start position:0% + +78 is that + + align:start position:0% +78 is that + + + align:start position:0% +78 is that +right + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay so in this case we do get a you + + align:start position:0% +okay so in this case we do get a you + + + align:start position:0% +okay so in this case we do get a you +know in some sense a weaker bound than + + align:start position:0% +know in some sense a weaker bound than + + + align:start position:0% +know in some sense a weaker bound than +we would have gotten by applying Markov + + align:start position:0% +we would have gotten by applying Markov + + + align:start position:0% +we would have gotten by applying Markov +to to t you know directly but you know + + align:start position:0% +to to t you know directly but you know + + + align:start position:0% +to to t you know directly but you know +applying Markov to T directly doesn't + + align:start position:0% +applying Markov to T directly doesn't + + + align:start position:0% +applying Markov to T directly doesn't +actually work this you know looks weaker + + align:start position:0% +actually work this you know looks weaker + + + align:start position:0% +actually work this you know looks weaker +but it's a correct bound okay so + + align:start position:0% +but it's a correct bound okay so + + + align:start position:0% +but it's a correct bound okay so +hopefully that answers your question + + align:start position:0% +hopefully that answers your question + + + align:start position:0% +hopefully that answers your question +more fully + + align:start position:0% + + + + align:start position:0% + +okay does anybody have any + + align:start position:0% +okay does anybody have any + + + align:start position:0% +okay does anybody have any +questions so even though we couldn't + + align:start position:0% +questions so even though we couldn't + + + align:start position:0% +questions so even though we couldn't +apply Markov directly to T we can create + + align:start position:0% +apply Markov directly to T we can create + + + align:start position:0% +apply Markov directly to T we can create +a new random variable T Prime to which + + align:start position:0% +a new random variable T Prime to which + + + align:start position:0% +a new random variable T Prime to which +marov does + + align:start position:0% +marov does + + + align:start position:0% +marov does +apply MH + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +uh so using the lower bound of 30 making + + align:start position:0% +uh so using the lower bound of 30 making + + + align:start position:0% +uh so using the lower bound of 30 making +the + + align:start position:0% +the + + + align:start position:0% +the +the the statement stronger for for t for + + align:start position:0% +the the statement stronger for for t for + + + align:start position:0% +the the statement stronger for for t for +S oh for S uh which one was s uh s here + + align:start position:0% +S oh for S uh which one was s uh s here + + + align:start position:0% +S oh for S uh which one was s uh s here +um so that does not really help us in + + align:start position:0% +um so that does not really help us in + + + align:start position:0% +um so that does not really help us in +this case um because that kind of + + align:start position:0% +this case um because that kind of + + + align:start position:0% +this case um because that kind of +corresponds to uh an upper + + align:start position:0% +corresponds to uh an upper + + + align:start position:0% +corresponds to uh an upper +bound right rather than rather than the + + align:start position:0% +bound right rather than rather than the + + + align:start position:0% +bound right rather than rather than the +lower bound uh and you know upper bounds + + align:start position:0% +lower bound uh and you know upper bounds + + + align:start position:0% +lower bound uh and you know upper bounds +don't really appear in in the proof of + + align:start position:0% +don't really appear in in the proof of + + + align:start position:0% +don't really appear in in the proof of +Markov like we're not really using them + + align:start position:0% +Markov like we're not really using them + + + align:start position:0% +Markov like we're not really using them +in any way so you know imposing a + + align:start position:0% +in any way so you know imposing a + + + align:start position:0% +in any way so you know imposing a +stronger upper bound doesn't really + + align:start position:0% +stronger upper bound doesn't really + + + align:start position:0% +stronger upper bound doesn't really +doesn't really help okay does does that + + align:start position:0% +doesn't really help okay does does that + + + align:start position:0% +doesn't really help okay does does that +kind of answer your question okay + + align:start position:0% +kind of answer your question okay + + + align:start position:0% +kind of answer your question okay +cool + + align:start position:0% + + + + align:start position:0% + +yeah uh okay is it always the case that + + align:start position:0% +yeah uh okay is it always the case that + + + align:start position:0% +yeah uh okay is it always the case that +the best lower bound appears or sorry + + align:start position:0% +the best lower bound appears or sorry + + + align:start position:0% +the best lower bound appears or sorry +the best upper bound I guess appears uh + + align:start position:0% +the best upper bound I guess appears uh + + + align:start position:0% +the best upper bound I guess appears uh +when uh when the the range actually + + align:start position:0% +when uh when the the range actually + + + align:start position:0% +when uh when the the range actually +includes + + align:start position:0% +includes + + + align:start position:0% +includes +zero um essentially yes + + align:start position:0% + + + + align:start position:0% + +okay as far as correct bounds go + + align:start position:0% + + + + align:start position:0% + +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +okay + + align:start position:0% +okay + + + align:start position:0% +okay +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so I guess there's a question of like + + align:start position:0% +so I guess there's a question of like + + + align:start position:0% +so I guess there's a question of like +morally why do we need this this non- + + align:start position:0% +morally why do we need this this non- + + + align:start position:0% +morally why do we need this this non- +negativity um + + align:start position:0% +negativity um + + + align:start position:0% +negativity um +and perhaps a very simple illustrative + + align:start position:0% +and perhaps a very simple illustrative + + + align:start position:0% +and perhaps a very simple illustrative +example is suppose we have the random + + align:start position:0% +example is suppose we have the random + + + align:start position:0% +example is suppose we have the random +variable R which is uh plus or minus one + + align:start position:0% +variable R which is uh plus or minus one + + + align:start position:0% +variable R which is uh plus or minus one +depending on you know a Fair coin flip + + align:start position:0% +depending on you know a Fair coin flip + + + align:start position:0% +depending on you know a Fair coin flip +okay so it's it's + + align:start position:0% + + + + align:start position:0% + +uniform on positive one and negative + + align:start position:0% +uniform on positive one and negative + + + align:start position:0% +uniform on positive one and negative +1 okay so if we try to apply Markov to + + align:start position:0% +1 okay so if we try to apply Markov to + + + align:start position:0% +1 okay so if we try to apply Markov to +to that + + align:start position:0% +to that + + + align:start position:0% +to that +corly + + align:start position:0% +corly + + + align:start position:0% +corly +right what does that tell us about the + + align:start position:0% +right what does that tell us about the + + + align:start position:0% +right what does that tell us about the +probability that R is greater + + align:start position:0% + + + + align:start position:0% + +than2 well if we try to apply marov + + align:start position:0% +than2 well if we try to apply marov + + + align:start position:0% +than2 well if we try to apply marov +directly right the expectation of R is + + align:start position:0% + + + + align:start position:0% + +zero so you know no matter what we put + + align:start position:0% +zero so you know no matter what we put + + + align:start position:0% +zero so you know no matter what we put +here marov would try to tell us that you + + align:start position:0% +here marov would try to tell us that you + + + align:start position:0% +here marov would try to tell us that you +know the probability is at most + + align:start position:0% +know the probability is at most + + + align:start position:0% +know the probability is at most +zero okay that is clearly rubbish right + + align:start position:0% +zero okay that is clearly rubbish right + + + align:start position:0% +zero okay that is clearly rubbish right +because you know R can be greater than + + align:start position:0% +because you know R can be greater than + + + align:start position:0% +because you know R can be greater than +1/2 R takes value one with probability + + align:start position:0% +1/2 R takes value one with probability + + + align:start position:0% +1/2 R takes value one with probability +1/2 + + align:start position:0% +1/2 + + + align:start position:0% +1/2 +okay so basically our proof uh where was + + align:start position:0% +okay so basically our proof uh where was + + + align:start position:0% +okay so basically our proof uh where was +it + + align:start position:0% + + + + align:start position:0% + +here so if we if we get rid of the non- + + align:start position:0% +here so if we if we get rid of the non- + + + align:start position:0% +here so if we if we get rid of the non- +negativity constraint then this no + + align:start position:0% +negativity constraint then this no + + + align:start position:0% +negativity constraint then this no +longer + + align:start position:0% +longer + + + align:start position:0% +longer +works right we can't kind of discard + + align:start position:0% +works right we can't kind of discard + + + align:start position:0% +works right we can't kind of discard +This this term because that zero you + + align:start position:0% +This this term because that zero you + + + align:start position:0% +This this term because that zero you +know if we don't know that the the + + align:start position:0% +know if we don't know that the the + + + align:start position:0% +know if we don't know that the the +random variable is non negative we could + + align:start position:0% +random variable is non negative we could + + + align:start position:0% +random variable is non negative we could +in principle have a have a negative + + align:start position:0% +in principle have a have a negative + + + align:start position:0% +in principle have a have a negative +value there which you know we we we + + align:start position:0% +value there which you know we we we + + + align:start position:0% +value there which you know we we we +can't get rid of + + align:start position:0% + + + + align:start position:0% + +okay so another + + align:start position:0% +okay so another + + + align:start position:0% +okay so another +question is Markov tight + + align:start position:0% + + + + align:start position:0% + +so in other + + align:start position:0% +so in other + + + align:start position:0% +so in other +words can we make a stronger statement + + align:start position:0% +words can we make a stronger statement + + + align:start position:0% +words can we make a stronger statement +than what marov tells us you know out of + + align:start position:0% +than what marov tells us you know out of + + + align:start position:0% +than what marov tells us you know out of +the + + align:start position:0% +the + + + align:start position:0% +the +tin just with you know the information + + align:start position:0% +tin just with you know the information + + + align:start position:0% +tin just with you know the information +that we we have the mean and we have a + + align:start position:0% +that we we have the mean and we have a + + + align:start position:0% +that we we have the mean and we have a +non- negative random + + align:start position:0% + + + + align:start position:0% + +variable is there anything stronger that + + align:start position:0% +variable is there anything stronger that + + + align:start position:0% +variable is there anything stronger that +we can + + align:start position:0% + + + + align:start position:0% + +say who thinks + + align:start position:0% + + + + align:start position:0% + +yes couple of tentative hands who thinks + + align:start position:0% +yes couple of tentative hands who thinks + + + align:start position:0% +yes couple of tentative hands who thinks +no uh couple of less tentative tons who + + align:start position:0% +no uh couple of less tentative tons who + + + align:start position:0% +no uh couple of less tentative tons who +has no + + align:start position:0% +has no + + + align:start position:0% +has no +idea okay well let's let's think about + + align:start position:0% +idea okay well let's let's think about + + + align:start position:0% +idea okay well let's let's think about +some some uh simple examples then okay + + align:start position:0% +some some uh simple examples then okay + + + align:start position:0% +some some uh simple examples then okay +so let's go back to the uh cell phone + + align:start position:0% +so let's go back to the uh cell phone + + + align:start position:0% +so let's go back to the uh cell phone +check problem from uh was it last week + + align:start position:0% +check problem from uh was it last week + + + align:start position:0% +check problem from uh was it last week +don't remember which of the lectures + + align:start position:0% +don't remember which of the lectures + + + align:start position:0% +don't remember which of the lectures +last week Tuesday Thursday both both + + align:start position:0% +last week Tuesday Thursday both both + + + align:start position:0% +last week Tuesday Thursday both both +okay okay so if we consider the Lazy + + align:start position:0% +okay okay so if we consider the Lazy + + + align:start position:0% +okay okay so if we consider the Lazy +Susan version + + align:start position:0% +Susan version + + + align:start position:0% +Susan version +right and we let R be the number + + align:start position:0% +right and we let R be the number + + + align:start position:0% +right and we let R be the number +of + + align:start position:0% +of + + + align:start position:0% +of +people + + align:start position:0% +people + + + align:start position:0% +people +who get their + + align:start position:0% + + + + align:start position:0% + +phone okay so this is the Lazy + + align:start position:0% + + + + align:start position:0% + +Susan + + align:start position:0% +Susan + + + align:start position:0% +Susan +uh how could we use Markov to bound the + + align:start position:0% +uh how could we use Markov to bound the + + + align:start position:0% +uh how could we use Markov to bound the +probability that everybody gets their + + align:start position:0% +probability that everybody gets their + + + align:start position:0% +probability that everybody gets their +phone back + + align:start position:0% + + + + align:start position:0% + +so if everybody gets their phone back + + align:start position:0% +so if everybody gets their phone back + + + align:start position:0% +so if everybody gets their phone back +right that's R equals + + align:start position:0% + + + + align:start position:0% + +n what does marov tell us about this + + align:start position:0% +n what does marov tell us about this + + + align:start position:0% +n what does marov tell us about this +probability + + align:start position:0% + + + + align:start position:0% + +yeah yeah it's the most one over + + align:start position:0% + + + + align:start position:0% + +n why is that well the expectation of R + + align:start position:0% +n why is that well the expectation of R + + + align:start position:0% +n why is that well the expectation of R +is one as we saw last week right the + + align:start position:0% +is one as we saw last week right the + + + align:start position:0% +is one as we saw last week right the +bound we're looking at is + + align:start position:0% +bound we're looking at is + + + align:start position:0% +bound we're looking at is +n okay so there's at most a one and + + align:start position:0% +n okay so there's at most a one and + + + align:start position:0% +n okay so there's at most a one and +probability that everybody gets their + + align:start position:0% +probability that everybody gets their + + + align:start position:0% +probability that everybody gets their +phone + + align:start position:0% +phone + + + align:start position:0% +phone +back what is the actual probability that + + align:start position:0% +back what is the actual probability that + + + align:start position:0% +back what is the actual probability that +everybody gets their phone + + align:start position:0% + + + + align:start position:0% + +back + + align:start position:0% +back + + + align:start position:0% +back +yeah yeah the actual probability is 1/ n + + align:start position:0% +yeah yeah the actual probability is 1/ n + + + align:start position:0% +yeah yeah the actual probability is 1/ n +so this is tight okay we can't say + + align:start position:0% +so this is tight okay we can't say + + + align:start position:0% +so this is tight okay we can't say +anything stronger than marov without + + align:start position:0% +anything stronger than marov without + + + align:start position:0% +anything stronger than marov without +additional + + align:start position:0% + + + + align:start position:0% + +information okay does that make + + align:start position:0% + + + + align:start position:0% + +sense so if we know something else about + + align:start position:0% +sense so if we know something else about + + + align:start position:0% +sense so if we know something else about +our distribution then we might be able + + align:start position:0% +our distribution then we might be able + + + align:start position:0% +our distribution then we might be able +to say something more but if all we know + + align:start position:0% +to say something more but if all we know + + + align:start position:0% +to say something more but if all we know +is the expectation and the the non- + + align:start position:0% +is the expectation and the the non- + + + align:start position:0% +is the expectation and the the non- +negativity then Markov is the best that + + align:start position:0% +negativity then Markov is the best that + + + align:start position:0% +negativity then Markov is the best that +we can + + align:start position:0% +we can + + + align:start position:0% +we can +do + + align:start position:0% + + + + align:start position:0% + +okay on the other hand you know suppose + + align:start position:0% +okay on the other hand you know suppose + + + align:start position:0% +okay on the other hand you know suppose +suppose we're permuting all of the + + align:start position:0% +suppose we're permuting all of the + + + align:start position:0% +suppose we're permuting all of the +phones instead of you know putting them + + align:start position:0% +phones instead of you know putting them + + + align:start position:0% +phones instead of you know putting them +on the Lazy + + align:start position:0% +on the Lazy + + + align:start position:0% +on the Lazy +Susan Okay so + + align:start position:0% + + + + align:start position:0% + +so in this case what does marov tell us + + align:start position:0% +so in this case what does marov tell us + + + align:start position:0% +so in this case what does marov tell us +about the uh probability that everybody + + align:start position:0% +about the uh probability that everybody + + + align:start position:0% +about the uh probability that everybody +gets their phone + + align:start position:0% + + + + align:start position:0% + +back it's still one over n right we've + + align:start position:0% +back it's still one over n right we've + + + align:start position:0% +back it's still one over n right we've +still got uh a non- negative random + + align:start position:0% +still got uh a non- negative random + + + align:start position:0% +still got uh a non- negative random +variable with the same mean we're still + + align:start position:0% +variable with the same mean we're still + + + align:start position:0% +variable with the same mean we're still +looking at the same threshold right so + + align:start position:0% +looking at the same threshold right so + + + align:start position:0% +looking at the same threshold right so +marov gives us the same bound + + align:start position:0% + + + + align:start position:0% + +okay what is the actual probability that + + align:start position:0% +okay what is the actual probability that + + + align:start position:0% +okay what is the actual probability that +everybody gets their phone back + + align:start position:0% + + + + align:start position:0% + +well that's that's exactly when you have + + align:start position:0% +well that's that's exactly when you have + + + align:start position:0% +well that's that's exactly when you have +the identity permutation right you've + + align:start position:0% +the identity permutation right you've + + + align:start position:0% +the identity permutation right you've +got n factorial possible permutations + + align:start position:0% +got n factorial possible permutations + + + align:start position:0% +got n factorial possible permutations +one of them gives everybody's phone + + align:start position:0% +one of them gives everybody's phone + + + align:start position:0% +one of them gives everybody's phone +back so what we're looking for is + + align:start position:0% +back so what we're looking for is + + + align:start position:0% +back so what we're looking for is +actually one/ n + + align:start position:0% +actually one/ n + + + align:start position:0% +actually one/ n +factorial okay so so marov is is very + + align:start position:0% +factorial okay so so marov is is very + + + align:start position:0% +factorial okay so so marov is is very +much not tight in this + + align:start position:0% + + + + align:start position:0% + +example okay + + align:start position:0% + + + + align:start position:0% + +okay so the next question is what can we + + align:start position:0% +okay so the next question is what can we + + + align:start position:0% +okay so the next question is what can we +say if we do have more information about + + align:start position:0% + + + + align:start position:0% + +uh about a random + + align:start position:0% + + + + align:start position:0% + +variable so suppose we know the + + align:start position:0% +variable so suppose we know the + + + align:start position:0% +variable so suppose we know the +variance okay so the variance of those + + align:start position:0% +variance okay so the variance of those + + + align:start position:0% +variance okay so the variance of those +two distributions is very different + + align:start position:0% +two distributions is very different + + + align:start position:0% +two distributions is very different +right uh in the case where we put the + + align:start position:0% +right uh in the case where we put the + + + align:start position:0% +right uh in the case where we put the +the phones on the Lazy Susan we've got a + + align:start position:0% +the phones on the Lazy Susan we've got a + + + align:start position:0% +the phones on the Lazy Susan we've got a +very high variance in the case where we + + align:start position:0% +very high variance in the case where we + + + align:start position:0% +very high variance in the case where we +have a random permutation it's much + + align:start position:0% +have a random permutation it's much + + + align:start position:0% +have a random permutation it's much +lower okay so maybe the variance can + + align:start position:0% +lower okay so maybe the variance can + + + align:start position:0% +lower okay so maybe the variance can +tell us you know + + align:start position:0% +tell us you know + + + align:start position:0% +tell us you know +more about these + + align:start position:0% + + + + align:start position:0% + +probabilities okay so this is a + + align:start position:0% +probabilities okay so this is a + + + align:start position:0% +probabilities okay so this is a +different tail bound uh due to Chubby + + align:start position:0% +different tail bound uh due to Chubby + + + align:start position:0% +different tail bound uh due to Chubby +Chev + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +probability that R minus the expectation + + align:start position:0% +probability that R minus the expectation + + + align:start position:0% +probability that R minus the expectation +of + + align:start position:0% +of + + + align:start position:0% +of +R uh you know an absolute value is at + + align:start position:0% +R uh you know an absolute value is at + + + align:start position:0% +R uh you know an absolute value is at +least + + align:start position:0% +least + + + align:start position:0% +least +X is less than or equal to the variance + + align:start position:0% +X is less than or equal to the variance + + + align:start position:0% +X is less than or equal to the variance +of + + align:start position:0% + + + + align:start position:0% + +x / + + align:start position:0% + + + + align:start position:0% + +x^2 okay + + align:start position:0% + + + + align:start position:0% + +so note that we no longer require non- + + align:start position:0% +so note that we no longer require non- + + + align:start position:0% +so note that we no longer require non- +negativity here we just require + + align:start position:0% +negativity here we just require + + + align:start position:0% +negativity here we just require +information about the + + align:start position:0% +information about the + + + align:start position:0% +information about the +variance okay and well the mean we have + + align:start position:0% +variance okay and well the mean we have + + + align:start position:0% +variance okay and well the mean we have +to uh we have to compute it relative to + + align:start position:0% +to uh we have to compute it relative to + + + align:start position:0% +to uh we have to compute it relative to +the + + align:start position:0% +the + + + align:start position:0% +the +mean + + align:start position:0% +mean + + + align:start position:0% +mean +okay so but but R can be any random + + align:start position:0% +okay so but but R can be any random + + + align:start position:0% +okay so but but R can be any random +variable we're we're no longer + + align:start position:0% +variable we're we're no longer + + + align:start position:0% +variable we're we're no longer +constrained to to looking at non- + + align:start position:0% +constrained to to looking at non- + + + align:start position:0% +constrained to to looking at non- +negative ones it can be anything we just + + align:start position:0% +negative ones it can be anything we just + + + align:start position:0% +negative ones it can be anything we just +have to compute the variance + + align:start position:0% +have to compute the variance + + + align:start position:0% +have to compute the variance +okay how might we prove chubby shvs + + align:start position:0% + + + + align:start position:0% + +inequality any + + align:start position:0% + + + + align:start position:0% + +ideas is that a hand or a stretch + + align:start position:0% +ideas is that a hand or a stretch + + + align:start position:0% +ideas is that a hand or a stretch +yeah yeah so we're we're going to prove + + align:start position:0% +yeah yeah so we're we're going to prove + + + align:start position:0% +yeah yeah so we're we're going to prove +Chev using + + align:start position:0% +Chev using + + + align:start position:0% +Chev using +marov okay so in order to use + + align:start position:0% + + + + align:start position:0% + +marov what do we need well we need an + + align:start position:0% +marov what do we need well we need an + + + align:start position:0% +marov what do we need well we need an +all negative random variable + + align:start position:0% +all negative random variable + + + align:start position:0% +all negative random variable +okay so kind of similar to what we were + + align:start position:0% +okay so kind of similar to what we were + + + align:start position:0% +okay so kind of similar to what we were +doing earlier with shifting our random + + align:start position:0% +doing earlier with shifting our random + + + align:start position:0% +doing earlier with shifting our random +variable we're going to define a new + + align:start position:0% +variable we're going to define a new + + + align:start position:0% +variable we're going to define a new +random variable that we can then apply + + align:start position:0% +random variable that we can then apply + + + align:start position:0% +random variable that we can then apply +Markov to and that should give us this + + align:start position:0% +Markov to and that should give us this + + + align:start position:0% +Markov to and that should give us this +result + + align:start position:0% +result + + + align:start position:0% +result +here + + align:start position:0% + + + + align:start position:0% + +okay does that make sense to + + align:start position:0% +okay does that make sense to + + + align:start position:0% +okay does that make sense to +everybody + + align:start position:0% + + + + align:start position:0% + +yeah oh variance of R sorry thank + + align:start position:0% +yeah oh variance of R sorry thank + + + align:start position:0% +yeah oh variance of R sorry thank +you yes variance of X does not make any + + align:start position:0% +you yes variance of X does not make any + + + align:start position:0% +you yes variance of X does not make any +sense + + align:start position:0% + + + + align:start position:0% + +okay so what might be a useful random + + align:start position:0% +okay so what might be a useful random + + + align:start position:0% +okay so what might be a useful random +variable that we can apply Markov + + align:start position:0% + + + + align:start position:0% + +to well maybe here's a way we can kind + + align:start position:0% +to well maybe here's a way we can kind + + + align:start position:0% +to well maybe here's a way we can kind +of + + align:start position:0% +of + + + align:start position:0% +of +cheat + + align:start position:0% +cheat + + + align:start position:0% +cheat +uh in markov's inequality what's the + + align:start position:0% +uh in markov's inequality what's the + + + align:start position:0% +uh in markov's inequality what's the +bound that we get + + align:start position:0% + + + + align:start position:0% + +the bound should be the expectation of + + align:start position:0% +the bound should be the expectation of + + + align:start position:0% +the bound should be the expectation of +our random variable + + align:start position:0% +our random variable + + + align:start position:0% +our random variable +right so can we Define a random variable + + align:start position:0% +right so can we Define a random variable + + + align:start position:0% +right so can we Define a random variable +whose expectation is the variance of of + + align:start position:0% + + + + align:start position:0% + +R + + align:start position:0% + + + + align:start position:0% + +yeah yeah exactly so R Prime equals R + + align:start position:0% +yeah yeah exactly so R Prime equals R + + + align:start position:0% +yeah yeah exactly so R Prime equals R +minus + + align:start position:0% + + + + align:start position:0% + +expectation + + align:start position:0% +expectation + + + align:start position:0% +expectation +squared okay + + align:start position:0% +squared okay + + + align:start position:0% +squared okay +so this is non- negative right it's it's + + align:start position:0% +so this is non- negative right it's it's + + + align:start position:0% +so this is non- negative right it's it's +a square of some + + align:start position:0% +a square of some + + + align:start position:0% +a square of some +value uh its expectation you know by + + align:start position:0% +value uh its expectation you know by + + + align:start position:0% +value uh its expectation you know by +definition is the variance of + + align:start position:0% +definition is the variance of + + + align:start position:0% +definition is the variance of +R + + align:start position:0% +R + + + align:start position:0% +R +okay and also if we kind of squint right + + align:start position:0% +okay and also if we kind of squint right + + + align:start position:0% +okay and also if we kind of squint right +we can fiddle around with this to you + + align:start position:0% +we can fiddle around with this to you + + + align:start position:0% +we can fiddle around with this to you +know actually threshold R Prime instead + + align:start position:0% +know actually threshold R Prime instead + + + align:start position:0% +know actually threshold R Prime instead +of this absolute value thing that we've + + align:start position:0% +of this absolute value thing that we've + + + align:start position:0% +of this absolute value thing that we've +got here how do we do + + align:start position:0% +got here how do we do + + + align:start position:0% +got here how do we do +that well we just Square the stuff in + + align:start position:0% +that well we just Square the stuff in + + + align:start position:0% +that well we just Square the stuff in +the absolute value right as the same + + align:start position:0% +the absolute value right as the same + + + align:start position:0% +the absolute value right as the same +square as if we didn't have the absolute + + align:start position:0% +square as if we didn't have the absolute + + + align:start position:0% +square as if we didn't have the absolute +value okay so the + + align:start position:0% +value okay so the + + + align:start position:0% +value okay so the +probability that R minus its + + align:start position:0% + + + + align:start position:0% + +expectation greater than or equal to + + align:start position:0% +expectation greater than or equal to + + + align:start position:0% +expectation greater than or equal to +x equals the + + align:start position:0% +x equals the + + + align:start position:0% +x equals the +probability that R + + align:start position:0% +probability that R + + + align:start position:0% +probability that R +Prime is greater than or equal to + + align:start position:0% +Prime is greater than or equal to + + + align:start position:0% +Prime is greater than or equal to +x^2 right because those are exactly the + + align:start position:0% +x^2 right because those are exactly the + + + align:start position:0% +x^2 right because those are exactly the +same event + + align:start position:0% +same event + + + align:start position:0% +same event +okay they're the same event so they have + + align:start position:0% +okay they're the same event so they have + + + align:start position:0% +okay they're the same event so they have +the same + + align:start position:0% +the same + + + align:start position:0% +the same +probability and now this looks like + + align:start position:0% +probability and now this looks like + + + align:start position:0% +probability and now this looks like +something we can apply Markov to okay + + align:start position:0% +something we can apply Markov to okay + + + align:start position:0% +something we can apply Markov to okay +less than or equal to the + + align:start position:0% +less than or equal to the + + + align:start position:0% +less than or equal to the +expectation of R Prime + + align:start position:0% +expectation of R Prime + + + align:start position:0% +expectation of R Prime +oops divided by + + align:start position:0% + + + + align:start position:0% + +x^2 okay does that make sense to + + align:start position:0% +x^2 okay does that make sense to + + + align:start position:0% +x^2 okay does that make sense to +everybody + + align:start position:0% + + + + align:start position:0% + +so let's take a look at an + + align:start position:0% + + + + align:start position:0% + +example so let's look at those test + + align:start position:0% +example so let's look at those test + + + align:start position:0% +example so let's look at those test +scores + + align:start position:0% +scores + + + align:start position:0% +scores +again oops sorry my bad + + align:start position:0% + + + + align:start position:0% + +so our same deal we've got test + + align:start position:0% + + + + align:start position:0% + +scores + + align:start position:0% +scores + + + align:start position:0% +scores +expectation is what did we have 70 75 + + align:start position:0% + + + + align:start position:0% + +75 and say that that the + + align:start position:0% + + + + align:start position:0% + +variance is + + align:start position:0% +variance is + + + align:start position:0% +variance is + + align:start position:0% + + + align:start position:0% +okay so now what can we + + align:start position:0% +okay so now what can we + + + align:start position:0% +okay so now what can we +say about the probability that R is uh + + align:start position:0% +say about the probability that R is uh + + + align:start position:0% +say about the probability that R is uh +most + + align:start position:0% + + + + align:start position:0% + +65 any + + align:start position:0% + + + + align:start position:0% + +ideas how how could we how could we + + align:start position:0% +ideas how how could we how could we + + + align:start position:0% +ideas how how could we how could we +apply treby Chef to + + align:start position:0% + + + + align:start position:0% + +this that doesn't quite look like the + + align:start position:0% +this that doesn't quite look like the + + + align:start position:0% +this that doesn't quite look like the +theorem statement right + + align:start position:0% + + + + align:start position:0% + +but we can observe that this is at most + + align:start position:0% +but we can observe that this is at most + + + align:start position:0% +but we can observe that this is at most +the + + align:start position:0% +the + + + align:start position:0% +the +probability that R is at most + + align:start position:0% +probability that R is at most + + + align:start position:0% +probability that R is at most + + align:start position:0% + + + align:start position:0% +or R is greater than or equal to + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +okay right if we take the union of two + + align:start position:0% +okay right if we take the union of two + + + align:start position:0% +okay right if we take the union of two +events that Union has you know at least + + align:start position:0% +events that Union has you know at least + + + align:start position:0% +events that Union has you know at least +the probability ility of one of those + + align:start position:0% +the probability ility of one of those + + + align:start position:0% +the probability ility of one of those +two con constituent + + align:start position:0% +two con constituent + + + align:start position:0% +two con constituent +events so this is only increasing the + + align:start position:0% +events so this is only increasing the + + + align:start position:0% +events so this is only increasing the +probability if we add in this this extra + + align:start position:0% +probability if we add in this this extra + + + align:start position:0% +probability if we add in this this extra +you + + align:start position:0% + + + + align:start position:0% + +know extra half of the + + align:start position:0% +know extra half of the + + + align:start position:0% +know extra half of the +event + + align:start position:0% + + + + align:start position:0% + +okay and what do we know about this + + align:start position:0% + + + + align:start position:0% + +probability how could we rewrite that in + + align:start position:0% +probability how could we rewrite that in + + + align:start position:0% +probability how could we rewrite that in +a nicer + + align:start position:0% + + + + align:start position:0% + +way + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +exactly so this is just saying R + + align:start position:0% +exactly so this is just saying R + + + align:start position:0% +exactly so this is just saying R +deviates from its mean by at least 10 + + align:start position:0% + + + + align:start position:0% + +okay so now we've got it in the form + + align:start position:0% +okay so now we've got it in the form + + + align:start position:0% +okay so now we've got it in the form +that chubby CHF + + align:start position:0% +that chubby CHF + + + align:start position:0% +that chubby CHF +likes so we can apply chabby + + align:start position:0% +likes so we can apply chabby + + + align:start position:0% +likes so we can apply chabby +Chev this is at most variance of + + align:start position:0% + + + + align:start position:0% + +r divided + + align:start position:0% + + + + align:start position:0% + +by uh our threshold is 10 yeah 10 + + align:start position:0% + + + + align:start position:0% + +squ okay + + align:start position:0% + + + + align:start position:0% + +25 over 100 + + align:start position:0% +25 over 100 + + + align:start position:0% +25 over 100 +equals + + align:start position:0% +equals + + + align:start position:0% +equals +one4 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now we've got a much stronger bound this + + align:start position:0% +now we've got a much stronger bound this + + + align:start position:0% +now we've got a much stronger bound this +time than we did earlier Yeah question + + align:start position:0% + + + + align:start position:0% + +ah okay so explain this + + align:start position:0% +ah okay so explain this + + + align:start position:0% +ah okay so explain this +equality okay uh so R less than or equal + + align:start position:0% +equality okay uh so R less than or equal + + + align:start position:0% +equality okay uh so R less than or equal +to 65 or R greater than or equal to + + align:start position:0% +to 65 or R greater than or equal to + + + align:start position:0% +to 65 or R greater than or equal to +85 um we could rewrite this as you know + + align:start position:0% +85 um we could rewrite this as you know + + + align:start position:0% +85 um we could rewrite this as you know +R minus uh well r - + + align:start position:0% + + + + align:start position:0% + +75 is uh less than or equal to -10 and + + align:start position:0% +75 is uh less than or equal to -10 and + + + align:start position:0% +75 is uh less than or equal to -10 and +this one is r - 75 + + align:start position:0% +this one is r - 75 + + + align:start position:0% +this one is r - 75 +greater than or equal to positive + + align:start position:0% +greater than or equal to positive + + + align:start position:0% +greater than or equal to positive +10 okay um so you know if you absolute + + align:start position:0% +10 okay um so you know if you absolute + + + align:start position:0% +10 okay um so you know if you absolute +value both of these you know they're + + align:start position:0% +value both of these you know they're + + + align:start position:0% +value both of these you know they're +both you know greater than greater than + + align:start position:0% +both you know greater than greater than + + + align:start position:0% +both you know greater than greater than +or equal to 10 okay does does that kind + + align:start position:0% +or equal to 10 okay does does that kind + + + align:start position:0% +or equal to 10 okay does does that kind +of make sense + + align:start position:0% + + + + align:start position:0% + +okay any other questions about uh about + + align:start position:0% +okay any other questions about uh about + + + align:start position:0% +okay any other questions about uh about +this this example + + align:start position:0% + + + + align:start position:0% + +so because we have more information than + + align:start position:0% +so because we have more information than + + + align:start position:0% +so because we have more information than +we + + align:start position:0% +we + + + align:start position:0% +we +had here right we can get a stronger + + align:start position:0% +had here right we can get a stronger + + + align:start position:0% +had here right we can get a stronger +bound okay knowing the variance helps us + + align:start position:0% + + + + align:start position:0% + +out so equivalently we could you know + + align:start position:0% +out so equivalently we could you know + + + align:start position:0% +out so equivalently we could you know +rephrase this in terms of uh you know + + align:start position:0% +rephrase this in terms of uh you know + + + align:start position:0% +rephrase this in terms of uh you know +standard + + align:start position:0% +standard + + + align:start position:0% +standard +deviations uh um where would be a good + + align:start position:0% +deviations uh um where would be a good + + + align:start position:0% +deviations uh um where would be a good +place to write + + align:start position:0% +place to write + + + align:start position:0% +place to write +this how about + + align:start position:0% +this how about + + + align:start position:0% +this how about +here so the + + align:start position:0% + + + + align:start position:0% + +probability of + + align:start position:0% +probability of + + + align:start position:0% +probability of +being at least two standard + + align:start position:0% + + + + align:start position:0% + +deviations from the + + align:start position:0% + + + + align:start position:0% + +mean is at most + + align:start position:0% +mean is at most + + + align:start position:0% +mean is at most +1/4 okay + + align:start position:0% + + + + align:start position:0% + +does anybody have any objections to that + + align:start position:0% +does anybody have any objections to that + + + align:start position:0% +does anybody have any objections to that +last statement + + align:start position:0% + + + + align:start position:0% + +so if you've uh taken a stats class you + + align:start position:0% +so if you've uh taken a stats class you + + + align:start position:0% +so if you've uh taken a stats class you +probably heard something very different + + align:start position:0% +probably heard something very different + + + align:start position:0% +probably heard something very different +from + + align:start position:0% + + + + align:start position:0% + +that oh nobody nobody's taken + + align:start position:0% +that oh nobody nobody's taken + + + align:start position:0% +that oh nobody nobody's taken +stats that's good high school stats is + + align:start position:0% +stats that's good high school stats is + + + align:start position:0% +stats that's good high school stats is +terrible um um oh that's on camera um + + align:start position:0% +terrible um um oh that's on camera um + + + align:start position:0% +terrible um um oh that's on camera um +never mind stats are great just uh it's + + align:start position:0% +never mind stats are great just uh it's + + + align:start position:0% +never mind stats are great just uh it's +it's good that that you've saved it for + + align:start position:0% +it's good that that you've saved it for + + + align:start position:0% +it's good that that you've saved it for +University instead of doing it in high + + align:start position:0% +University instead of doing it in high + + + align:start position:0% +University instead of doing it in high +school + + align:start position:0% +school + + + align:start position:0% +school +um okay so yeah if if you're looking at + + align:start position:0% +um okay so yeah if if you're looking at + + + align:start position:0% +um okay so yeah if if you're looking at +a a you know a normal distribution right + + align:start position:0% +a a you know a normal distribution right + + + align:start position:0% +a a you know a normal distribution right +you actually have a much a much better + + align:start position:0% +you actually have a much a much better + + + align:start position:0% +you actually have a much a much better +bound than than 1/4 it's something like + + align:start position:0% +bound than than 1/4 it's something like + + + align:start position:0% +bound than than 1/4 it's something like +you know a few + + align:start position:0% +you know a few + + + align:start position:0% +you know a few +percent okay uh so why is + + align:start position:0% +percent okay uh so why is + + + align:start position:0% +percent okay uh so why is +that any ideas + + align:start position:0% + + + + align:start position:0% + +well for normal distribution right we + + align:start position:0% +well for normal distribution right we + + + align:start position:0% +well for normal distribution right we +know a lot more about the uh about the + + align:start position:0% +know a lot more about the uh about the + + + align:start position:0% +know a lot more about the uh about the +random variable than just its + + align:start position:0% +random variable than just its + + + align:start position:0% +random variable than just its +variance okay so if we know more even + + align:start position:0% +variance okay so if we know more even + + + align:start position:0% +variance okay so if we know more even +more about a random variable than its + + align:start position:0% +more about a random variable than its + + + align:start position:0% +more about a random variable than its +variance it turns out we can make even + + align:start position:0% +variance it turns out we can make even + + + align:start position:0% +variance it turns out we can make even +stronger + + align:start position:0% +stronger + + + align:start position:0% +stronger +statements okay just like adding in the + + align:start position:0% +statements okay just like adding in the + + + align:start position:0% +statements okay just like adding in the +variance was an upgrade from marov let's + + align:start position:0% +variance was an upgrade from marov let's + + + align:start position:0% +variance was an upgrade from marov let's +see how we can upgrade this again + + align:start position:0% + + + + align:start position:0% + +yeah what's upal distrib oh what's a + + align:start position:0% +yeah what's upal distrib oh what's a + + + align:start position:0% +yeah what's upal distrib oh what's a +normal distribution uh think of a normal + + align:start position:0% +normal distribution uh think of a normal + + + align:start position:0% +normal distribution uh think of a normal +distribution as um you know number of + + align:start position:0% +distribution as um you know number of + + + align:start position:0% +distribution as um you know number of +heads if you flip a whole bunch of coins + + align:start position:0% +heads if you flip a whole bunch of coins + + + align:start position:0% +heads if you flip a whole bunch of coins +it's that's not quite it but you know + + align:start position:0% +it's that's not quite it but you know + + + align:start position:0% +it's that's not quite it but you know +roughly + + align:start position:0% +roughly + + + align:start position:0% +roughly +speaking good + + align:start position:0% + + + + align:start position:0% + +cutch oh okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% + + + + align:start position:0% + +okay so yeah as I just said if you flip + + align:start position:0% +okay so yeah as I just said if you flip + + + align:start position:0% +okay so yeah as I just said if you flip +a whole bunch of coins let your random + + align:start position:0% +a whole bunch of coins let your random + + + align:start position:0% +a whole bunch of coins let your random +variable R be the the number of heads + + align:start position:0% +variable R be the the number of heads + + + align:start position:0% +variable R be the the number of heads +right uh you know a lot more about uh + + align:start position:0% +right uh you know a lot more about uh + + + align:start position:0% +right uh you know a lot more about uh +about this random variable than just its + + align:start position:0% +about this random variable than just its + + + align:start position:0% +about this random variable than just its +variance right you're you can decompose + + align:start position:0% +variance right you're you can decompose + + + align:start position:0% +variance right you're you can decompose +the random variable into a sum of a + + align:start position:0% +the random variable into a sum of a + + + align:start position:0% +the random variable into a sum of a +whole bunch of + + align:start position:0% +whole bunch of + + + align:start position:0% +whole bunch of +indicators okay and all of those + + align:start position:0% +indicators okay and all of those + + + align:start position:0% +indicators okay and all of those +indicators are mutually + + align:start position:0% +indicators are mutually + + + align:start position:0% +indicators are mutually +independent + + align:start position:0% +independent + + + align:start position:0% +independent +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um in order to use chubby Chev right you + + align:start position:0% +um in order to use chubby Chev right you + + + align:start position:0% +um in order to use chubby Chev right you +don't need Mutual Independence right if + + align:start position:0% +don't need Mutual Independence right if + + + align:start position:0% +don't need Mutual Independence right if +you had something of that form you just + + align:start position:0% +you had something of that form you just + + + align:start position:0% +you had something of that form you just +need parir wise Independence right like + + align:start position:0% +need parir wise Independence right like + + + align:start position:0% +need parir wise Independence right like +you need to compute the + + align:start position:0% +you need to compute the + + + align:start position:0% +you need to compute the +variance okay + + align:start position:0% +variance okay + + + align:start position:0% +variance okay +but if on top of that you have mutual + + align:start position:0% +but if on top of that you have mutual + + + align:start position:0% +but if on top of that you have mutual +Independence it turns out you can do a + + align:start position:0% +Independence it turns out you can do a + + + align:start position:0% +Independence it turns out you can do a +lot + + align:start position:0% +lot + + + align:start position:0% +lot +better okay so + + align:start position:0% + + + + align:start position:0% + +suppose + + align:start position:0% + + + + align:start position:0% + +uh T1 T2 + + align:start position:0% +uh T1 T2 + + + align:start position:0% +uh T1 T2 +T3 up to TN are mutually independent + + align:start position:0% + + + + align:start position:0% + +random + + align:start position:0% +random + + + align:start position:0% +random +variables and uh well let's say in + + align:start position:0% +variables and uh well let's say in + + + align:start position:0% +variables and uh well let's say in +addition they're + + align:start position:0% +addition they're + + + align:start position:0% +addition they're +bounded + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +okay and the random variable we actually + + align:start position:0% +okay and the random variable we actually + + + align:start position:0% +okay and the random variable we actually +care about is T which is their + + align:start position:0% + + + + align:start position:0% + +sum + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +then oh and uh say we've also got some + + align:start position:0% +then oh and uh say we've also got some + + + align:start position:0% +then oh and uh say we've also got some +threshold C which is at least + + align:start position:0% +threshold C which is at least + + + align:start position:0% +threshold C which is at least +one uh the probability + + align:start position:0% +one uh the probability + + + align:start position:0% +one uh the probability +that t is at least c times its + + align:start position:0% + + + + align:start position:0% + +expectation uh close that as well less + + align:start position:0% +expectation uh close that as well less + + + align:start position:0% +expectation uh close that as well less +than or equal to e to the + + align:start position:0% +than or equal to e to the + + + align:start position:0% +than or equal to e to the +negative C log of C minus C + + + align:start position:0% +negative C log of C minus C + + + + align:start position:0% +negative C log of C minus C + + + align:start position:0% + + + align:start position:0% +times uh the + + align:start position:0% +times uh the + + + align:start position:0% +times uh the +expectation of t + + align:start position:0% + + + + align:start position:0% + +okay so a little bit of a + + align:start position:0% + + + + align:start position:0% + +mouthful but what exactly is going on + + align:start position:0% + + + + align:start position:0% + +here so basically marov was saying right + + align:start position:0% +here so basically marov was saying right + + + align:start position:0% +here so basically marov was saying right +uh that the the probability that you you + + align:start position:0% +uh that the the probability that you you + + + align:start position:0% +uh that the the probability that you you +know deviate from from the mean by a + + align:start position:0% +know deviate from from the mean by a + + + align:start position:0% +know deviate from from the mean by a +large + + align:start position:0% +large + + + align:start position:0% +large +amount uh it's at most you + + align:start position:0% +amount uh it's at most you + + + align:start position:0% +amount uh it's at most you +know it's at most linear in in you know + + align:start position:0% +know it's at most linear in in you know + + + align:start position:0% +know it's at most linear in in you know +how how far you're you're you're + + align:start position:0% +how how far you're you're you're + + + align:start position:0% +how how far you're you're you're +deviating okay Chev said it's uh you + + align:start position:0% +deviating okay Chev said it's uh you + + + align:start position:0% +deviating okay Chev said it's uh you +know at most quadratic this is saying + + align:start position:0% +know at most quadratic this is saying + + + align:start position:0% +know at most quadratic this is saying +it's at most exponential or like inverse + + align:start position:0% +it's at most exponential or like inverse + + + align:start position:0% +it's at most exponential or like inverse +exponential okay so you have a much + + align:start position:0% +exponential okay so you have a much + + + align:start position:0% +exponential okay so you have a much +stronger condition that gives you a much + + align:start position:0% +stronger condition that gives you a much + + + align:start position:0% +stronger condition that gives you a much +stronger bound + + align:start position:0% + + + + align:start position:0% + +okay uh and how could we prove + + align:start position:0% + + + + align:start position:0% + +it not like this + + align:start position:0% + + + + align:start position:0% + +any ideas + + align:start position:0% + + + + align:start position:0% + +maybe a proof sketch we we won't go + + align:start position:0% +maybe a proof sketch we we won't go + + + align:start position:0% +maybe a proof sketch we we won't go +through the entire proof + + align:start position:0% + + + + align:start position:0% + +so what what tools do we have already + + align:start position:0% +so what what tools do we have already + + + align:start position:0% +so what what tools do we have already +what might we be able to do + + align:start position:0% + + + + align:start position:0% + +well what happens if we apply + + align:start position:0% + + + + align:start position:0% + +Markov how can we apply + + align:start position:0% + + + + align:start position:0% + +Markov in order to use Markov right we + + align:start position:0% +Markov in order to use Markov right we + + + align:start position:0% +Markov in order to use Markov right we +need a non- negative random + + align:start position:0% + + + + align:start position:0% + +variable so in order to prove chubby + + align:start position:0% +variable so in order to prove chubby + + + align:start position:0% +variable so in order to prove chubby +right we uh you know took a square that + + align:start position:0% +right we uh you know took a square that + + + align:start position:0% +right we uh you know took a square that +made something non- + + align:start position:0% +made something non- + + + align:start position:0% +made something non- +negative what might be a reasonable + + align:start position:0% +negative what might be a reasonable + + + align:start position:0% +negative what might be a reasonable +thing to try in this + + align:start position:0% + + + + align:start position:0% + +case + + align:start position:0% +case + + + align:start position:0% +case +yeah add + + align:start position:0% +yeah add + + + align:start position:0% +yeah add +one uh okay so + + align:start position:0% +one uh okay so + + + align:start position:0% +one uh okay so +look at t + one instead of uh instead of + + align:start position:0% + + + + align:start position:0% + +T so that's actually going to that's not + + align:start position:0% +T so that's actually going to that's not + + + align:start position:0% +T so that's actually going to that's not +going to help us right T is already the + + align:start position:0% +going to help us right T is already the + + + align:start position:0% +going to help us right T is already the +sum of a bunch of non- negative random + + align:start position:0% +sum of a bunch of non- negative random + + + align:start position:0% +sum of a bunch of non- negative random +variables so it's already non- negative + + align:start position:0% +variables so it's already non- negative + + + align:start position:0% +variables so it's already non- negative +right like we're we're not looking to + + align:start position:0% +right like we're we're not looking to + + + align:start position:0% +right like we're we're not looking to +you know turn a non- negative or sorry + + align:start position:0% +you know turn a non- negative or sorry + + + align:start position:0% +you know turn a non- negative or sorry +turn an arbitrary random variable into a + + align:start position:0% +turn an arbitrary random variable into a + + + align:start position:0% +turn an arbitrary random variable into a +non negative one we are trying to find a + + align:start position:0% +non negative one we are trying to find a + + + align:start position:0% +non negative one we are trying to find a +more + + align:start position:0% +more + + + align:start position:0% +more +useful uh non- negative random + + align:start position:0% +useful uh non- negative random + + + align:start position:0% +useful uh non- negative random +variable okay + + align:start position:0% +variable okay + + + align:start position:0% +variable okay +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah take the log of both sides close + + align:start position:0% + + + + align:start position:0% + +what happens if we + + align:start position:0% + + + + align:start position:0% + +exponentiate + + align:start position:0% +exponentiate + + + align:start position:0% +exponentiate +so take T Prime equals c to the T + + align:start position:0% + + + + align:start position:0% + +what do we know about t + + align:start position:0% + + + + align:start position:0% + +Prime for + + align:start position:0% + + + + align:start position:0% + +well we're taking something that's at + + align:start position:0% +well we're taking something that's at + + + align:start position:0% +well we're taking something that's at +least one right or you know raising it + + align:start position:0% +least one right or you know raising it + + + align:start position:0% +least one right or you know raising it +to some positive power well some non- + + align:start position:0% +to some positive power well some non- + + + align:start position:0% +to some positive power well some non- +negative + + align:start position:0% +negative + + + align:start position:0% +negative +power + + align:start position:0% + + + + align:start position:0% + +okay so T Prime is a non negative random + + align:start position:0% +okay so T Prime is a non negative random + + + align:start position:0% +okay so T Prime is a non negative random +variable + + align:start position:0% + + + + align:start position:0% + +do we know anything more about + + align:start position:0% + + + + align:start position:0% + +it yeah it's at least one + + align:start position:0% +it yeah it's at least one + + + align:start position:0% +it yeah it's at least one +yeah so maybe we try applying markup to + + align:start position:0% + + + + align:start position:0% + +this okay so now we've got a random + + align:start position:0% +this okay so now we've got a random + + + align:start position:0% +this okay so now we've got a random +variable that takes values in the range + + align:start position:0% +variable that takes values in the range + + + align:start position:0% +variable that takes values in the range +from 0 to uh C the n c the N minus + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +okay now how could we rewrite this + + align:start position:0% +okay now how could we rewrite this + + + align:start position:0% +okay now how could we rewrite this +condition T greater than or equal to C + + align:start position:0% +condition T greater than or equal to C + + + align:start position:0% +condition T greater than or equal to C +* expectation of T in terms of T Prime + + align:start position:0% + + + + align:start position:0% + +well because C is at least one + + align:start position:0% +well because C is at least one + + + align:start position:0% +well because C is at least one +right exponentiation is + + align:start position:0% +right exponentiation is + + + align:start position:0% +right exponentiation is +monotone so this is the same as you know + + align:start position:0% +monotone so this is the same as you know + + + align:start position:0% +monotone so this is the same as you know +C to the T greater than or equal to uh C + + align:start position:0% +C to the T greater than or equal to uh C + + + align:start position:0% +C to the T greater than or equal to uh C +to the C * + + align:start position:0% + + + + align:start position:0% + +expectation of + + align:start position:0% + + + + align:start position:0% + +T + + align:start position:0% + + + + align:start position:0% + +okay and we don't have too much time so + + align:start position:0% +okay and we don't have too much time so + + + align:start position:0% +okay and we don't have too much time so +I think I will refer you to the book if + + align:start position:0% +I think I will refer you to the book if + + + align:start position:0% +I think I will refer you to the book if +you are interested but the the main idea + + align:start position:0% +you are interested but the the main idea + + + align:start position:0% +you are interested but the the main idea +right + + align:start position:0% +right + + + align:start position:0% +right +is this step here + + align:start position:0% +is this step here + + + align:start position:0% +is this step here +okay you take the random variable you + + align:start position:0% +okay you take the random variable you + + + align:start position:0% +okay you take the random variable you +care about and you exponentiate + + align:start position:0% +care about and you exponentiate + + + align:start position:0% +care about and you exponentiate +it okay and then if you apply apply + + align:start position:0% +it okay and then if you apply apply + + + align:start position:0% +it okay and then if you apply apply +Markov to that right it actually gives + + align:start position:0% +Markov to that right it actually gives + + + align:start position:0% +Markov to that right it actually gives +you a much stronger bound like you know + + align:start position:0% +you a much stronger bound like you know + + + align:start position:0% +you a much stronger bound like you know +if you're if you're using the the mutal + + align:start position:0% +if you're if you're using the the mutal + + + align:start position:0% +if you're if you're using the the mutal +independence of all of the component + + align:start position:0% +independence of all of the component + + + align:start position:0% +independence of all of the component +random variables + + align:start position:0% +random variables + + + align:start position:0% +random variables +right this will give you a much stronger + + align:start position:0% +right this will give you a much stronger + + + align:start position:0% +right this will give you a much stronger +bound than uh than even Shoff okay so I + + align:start position:0% +bound than uh than even Shoff okay so I + + + align:start position:0% +bound than uh than even Shoff okay so I +promised you last week that uh you know + + align:start position:0% +promised you last week that uh you know + + + align:start position:0% +promised you last week that uh you know +we would revisit the uh the coin tosses + + align:start position:0% +we would revisit the uh the coin tosses + + + align:start position:0% +we would revisit the uh the coin tosses +so let's do that + + align:start position:0% +so let's do that + + + align:start position:0% +so let's do that +briefly okay so + + align:start position:0% + + + + align:start position:0% + +suppose R is the + + align:start position:0% +suppose R is the + + + align:start position:0% +suppose R is the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +heads uh if you flip end coins + + align:start position:0% + + + + align:start position:0% + +okay so if you recall we were looking at + + align:start position:0% +okay so if you recall we were looking at + + + align:start position:0% +okay so if you recall we were looking at +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +probability that R is uh equal to you + + align:start position:0% +probability that R is uh equal to you + + + align:start position:0% +probability that R is uh equal to you +know n + + align:start position:0% +know n + + + align:start position:0% +know n +over4 + + align:start position:0% +over4 + + + align:start position:0% +over4 +before okay so or maybe + + align:start position:0% +before okay so or maybe + + + align:start position:0% +before okay so or maybe +equivalently three over + + align:start position:0% +equivalently three over + + + align:start position:0% +equivalently three over +4 might be a better way to + + align:start position:0% +4 might be a better way to + + + align:start position:0% +4 might be a better way to +to + + align:start position:0% +to + + + align:start position:0% +to +analogize okay and I promised you that + + align:start position:0% +analogize okay and I promised you that + + + align:start position:0% +analogize okay and I promised you that +we would + + align:start position:0% +we would + + + align:start position:0% +we would +revisit this probability R greater than + + align:start position:0% +revisit this probability R greater than + + + align:start position:0% +revisit this probability R greater than +or equal to 3 n / + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +okay now what happens if we apply + + align:start position:0% +okay now what happens if we apply + + + align:start position:0% +okay now what happens if we apply +uh each of our three tail bounds to + + align:start position:0% + + + + align:start position:0% + +R well first what happens with + + align:start position:0% + + + + align:start position:0% + +Markov so let's call this p + + align:start position:0% + + + + align:start position:0% + +p is at most + + align:start position:0% + + + + align:start position:0% + +what well the probability that R is at + + align:start position:0% +what well the probability that R is at + + + align:start position:0% +what well the probability that R is at +least you know some + + align:start position:0% +least you know some + + + align:start position:0% +least you know some +threshold it's going to be the + + align:start position:0% +threshold it's going to be the + + + align:start position:0% +threshold it's going to be the +expectation of + + align:start position:0% +expectation of + + + align:start position:0% +expectation of +r divided by this + + align:start position:0% + + + + align:start position:0% + +threshold okay what's the expectation of + + align:start position:0% +threshold okay what's the expectation of + + + align:start position:0% +threshold okay what's the expectation of +R and over + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +okay so this is going to be 2/3 + + align:start position:0% + + + + align:start position:0% + +what about chubby + + align:start position:0% + + + + align:start position:0% + +shf so similar to what we did with the + + align:start position:0% +shf so similar to what we did with the + + + align:start position:0% +shf so similar to what we did with the +first chbby Chev + + align:start position:0% + + + + align:start position:0% + +example right p is going to be at most + + align:start position:0% +example right p is going to be at most + + + align:start position:0% +example right p is going to be at most +the probability that uh R differs from + + align:start position:0% +the probability that uh R differs from + + + align:start position:0% +the probability that uh R differs from +its it expectation in either + + align:start position:0% +its it expectation in either + + + align:start position:0% +its it expectation in either +direction right by + + align:start position:0% +direction right by + + + align:start position:0% +direction right by +n/4 + + align:start position:0% +n/4 + + + align:start position:0% +n/4 +okay so what does that give us uh + + align:start position:0% +okay so what does that give us uh + + + align:start position:0% +okay so what does that give us uh +probability R minus let's say over + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +uh greater than or equal to n + + align:start position:0% + + + + align:start position:0% + +over4 is at most + + align:start position:0% +over4 is at most + + + align:start position:0% +over4 is at most +bar of + + align:start position:0% +bar of + + + align:start position:0% +bar of +r divided by uh n over 4^ + + align:start position:0% + + + + align:start position:0% + +s okay so what is the uh what is the + + align:start position:0% +s okay so what is the uh what is the + + + align:start position:0% +s okay so what is the uh what is the +variance of r + + align:start position:0% + + + + align:start position:0% + +does anybody + + align:start position:0% + + + + align:start position:0% + +remember we've got a sum of a bunch of + + align:start position:0% +remember we've got a sum of a bunch of + + + align:start position:0% +remember we've got a sum of a bunch of +indicators right they're all mutually + + align:start position:0% +indicators right they're all mutually + + + align:start position:0% +indicators right they're all mutually +independent so the variance is + + align:start position:0% +independent so the variance is + + + align:start position:0% +independent so the variance is +linear what's the variance of a single + + align:start position:0% + + + + align:start position:0% + +indicator + + align:start position:0% +indicator + + + align:start position:0% +indicator +nobody yeah + + align:start position:0% +nobody yeah + + + align:start position:0% +nobody yeah +yeah n over four oh for for R not for a + + align:start position:0% +yeah n over four oh for for R not for a + + + align:start position:0% +yeah n over four oh for for R not for a +single + + align:start position:0% +single + + + align:start position:0% +single +one + + align:start position:0% +one + + + align:start position:0% +one +okay so n over 4 / n^2 over + + align:start position:0% +okay so n over 4 / n^2 over + + + align:start position:0% +okay so n over 4 / n^2 over +16 equal 4 + + align:start position:0% +16 equal 4 + + + align:start position:0% +16 equal 4 +n + + align:start position:0% +n + + + align:start position:0% +n +okay so much better right much better + + align:start position:0% +okay so much better right much better + + + align:start position:0% +okay so much better right much better +than the 2/3 we just + + align:start position:0% +than the 2/3 we just + + + align:start position:0% +than the 2/3 we just +got what happens if we use turnoff + + align:start position:0% + + + + align:start position:0% + +okay any + + align:start position:0% +okay any + + + align:start position:0% +okay any +ideas + + align:start position:0% +ideas + + + align:start position:0% +ideas +yeah plug in three halves for C so c + + align:start position:0% +yeah plug in three halves for C so c + + + align:start position:0% +yeah plug in three halves for C so c +equal 3 + + align:start position:0% +equal 3 + + + align:start position:0% +equal 3 +Hales okay + + align:start position:0% + + + + align:start position:0% + +uh okay um why don't I uh put TR off + + align:start position:0% +uh okay um why don't I uh put TR off + + + align:start position:0% +uh okay um why don't I uh put TR off +back up + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +uh + + align:start position:0% + + + + align:start position:0% + +okay and what does that give us + + align:start position:0% +okay and what does that give us + + + align:start position:0% +okay and what does that give us +probability that uh R is is at least 3es + + align:start position:0% +probability that uh R is is at least 3es + + + align:start position:0% +probability that uh R is is at least 3es +time expectation of + + align:start position:0% + + + + align:start position:0% + +R is less than or equal to e to the + + align:start position:0% +R is less than or equal to e to the + + + align:start position:0% +R is less than or equal to e to the +minus is it C log + + align:start position:0% + + + + align:start position:0% + +C minus C + 1 so this is a constant + + align:start position:0% +C minus C + 1 so this is a constant + + + align:start position:0% +C minus C + 1 so this is a constant +times the expectation of + + align:start position:0% +times the expectation of + + + align:start position:0% +times the expectation of +R + + align:start position:0% +R + + + align:start position:0% +R +okay so the expectation of r R is n + + align:start position:0% +okay so the expectation of r R is n + + + align:start position:0% +okay so the expectation of r R is n +/2 right this is a constant so we've got + + align:start position:0% +/2 right this is a constant so we've got + + + align:start position:0% +/2 right this is a constant so we've got +something that's exponential or inverse + + align:start position:0% +something that's exponential or inverse + + + align:start position:0% +something that's exponential or inverse +exponential in + + align:start position:0% + + + + align:start position:0% + +N oops + + align:start position:0% + + + + align:start position:0% + +uh e to the minus order + + align:start position:0% +uh e to the minus order + + + align:start position:0% +uh e to the minus order +n + + align:start position:0% + + + + align:start position:0% + +okay so marov gives us gave us a really + + align:start position:0% +okay so marov gives us gave us a really + + + align:start position:0% +okay so marov gives us gave us a really +bad found chabby Chev you know + + align:start position:0% +bad found chabby Chev you know + + + align:start position:0% +bad found chabby Chev you know +linear pretty reasonable turn off gives + + align:start position:0% +linear pretty reasonable turn off gives + + + align:start position:0% +linear pretty reasonable turn off gives +us + + align:start position:0% +us + + + align:start position:0% +us +exponential okay so that's all we have + + align:start position:0% +exponential okay so that's all we have + + + align:start position:0% +exponential okay so that's all we have +time for today sorry I went a little bit + + align:start position:0% +time for today sorry I went a little bit + + + align:start position:0% +time for today sorry I went a little bit +overtime uh it's been a pleasure + + align:start position:0% +overtime uh it's been a pleasure + + + align:start position:0% +overtime uh it's been a pleasure +teaching you all this semester um and uh + + align:start position:0% +teaching you all this semester um and uh + + + align:start position:0% +teaching you all this semester um and uh +let's see we have uh the rest of our + + align:start position:0% +let's see we have uh the rest of our + + + align:start position:0% +let's see we have uh the rest of our +instructors and at least one ta hello + + align:start position:0% +instructors and at least one ta hello + + + align:start position:0% +instructors and at least one ta hello +Lily uh yeah if anything went wrong it + + align:start position:0% +Lily uh yeah if anything went wrong it + + + align:start position:0% +Lily uh yeah if anything went wrong it +was probably my fault um anything that + + align:start position:0% +was probably my fault um anything that + + + align:start position:0% +was probably my fault um anything that +went right uh you have your Tas to thank + + align:start position:0% +went right uh you have your Tas to thank + + + align:start position:0% +went right uh you have your Tas to thank +for it um including Lily ly Lily's + + align:start position:0% +for it um including Lily ly Lily's + + + align:start position:0% +for it um including Lily ly Lily's +amazing um so yeah perhaps I will see + + align:start position:0% +amazing um so yeah perhaps I will see + + + align:start position:0% +amazing um so yeah perhaps I will see +some of you uh next term in uh in 61 121 + + align:start position:0% +some of you uh next term in uh in 61 121 + + + align:start position:0% +some of you uh next term in uh in 61 121 +um good luck on the final make sure you + + align:start position:0% +um good luck on the final make sure you + + + align:start position:0% +um good luck on the final make sure you +take the right one uh thanks for being + + align:start position:0% +take the right one uh thanks for being + + + align:start position:0% +take the right one uh thanks for being +students in this class it's been lots of + + align:start position:0% +students in this class it's been lots of + + + align:start position:0% +students in this class it's been lots of +fun yeah + + align:start position:0% +fun yeah + + + align:start position:0% +fun yeah +[Applause] \ No newline at end of file diff --git a/88fqFjfxgwI.txt b/88fqFjfxgwI.txt new file mode 100644 index 0000000000000000000000000000000000000000..19e44e4e90bd350765765525d57f32ee833b7ddc --- /dev/null +++ b/88fqFjfxgwI.txt @@ -0,0 +1,2289 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So the way that I +envision recitations going is + +I'll start off kind of reviewing +some of the points, + +some of the high points from +lectures, might go into detail + +on some of the more +important topics. + +And this is also a time for +you to ask questions. + +There's only 25-30 of you here, +so you should feel a + +little bit more comfortable +asking questions. + +And there are no stupid +questions here. + +For the most part, you're all +beginners at programming. + +Am I wrong? + +Has anyone programmed +here before? + +OK. + +So presumably, none of you have +any experience with what + +we're talking about. + +And so if you ask a question, no +matter how basic you think + +it is, it's not stupid. + +Because everyone's been there, +including me and the professor + +when we started programing. + +And we've made, ourselves, +really stupid mistakes too. + +So. + +That said. + +We started out by talking +about the purpose of the + +class, which is to teach you +how to take problems, real + +world problems, break them down, +abstract them, and divvy + +them up so that you can solve +them with a computer. + +And when we talk about computer, +we're talking about + +a very simple model where-- + +and this is the only time you'll +see anything related to + +hardware in this class. + +When we talk about a computer, +we're talking about something + +very simple with a CPU and +memory and maybe some input + +and output. + +All right. + +And when we talk about programs, +these are sequences + +of instructions that are loaded +into the computer's + +memory which can be divided up +into little cells like this. + +All right. + +And what they might +look like is-- + +This actually doesn't mean +anything, but it's just, you + +know, for the sake +of demonstration. + +This is what a computer +would see. + +As the CPU starts running +a program, it looks at + +whatever's in this memory +location and says, this is an + +instruction I can handle, +so I'm gonna go do this. + +So this might be like add +two numbers together + +and produce a result. + +Something very simple, +very basic. + +And as it moves along in a +straight line fashion, it just + +executes this instruction, +this instruction, this + +instruction, et cetera, +et cetera. + +The problem is is that while +the computer is perfectly + +happy to look at this, this +is gibberish to us. + +And most people, most sane +people, if they're actually + +looking at computer code, +can't decipher this. + +So this is where programming +languages come in. + +We can move up a level. + +We can abstract away from this, +and maybe say something + +like this stands for -- + +move a number into a register +or something like that. + +You don't have to know +what this means. + +All you have to know is that +this is a little bit more + +readable than this. + +And it represents an instruction +that the computer + +can understand. + +The problem is that even at this +level, this is still very + +atomic and very low level, and +really you can't understand + +what's going on. + +So-- + +just so I can fill this in. + +We move into say, I'm gonna say +x is equal to 1 and I'm + +gonna add x plus 5 and +then multiply by 2. + +This is a lot easier for +us to understand. + +And this is what we're talking +about when we're talking about + +any sort of programming +language that we'll be + +studying in this course. + +And we're studying Python. + +So there are hundreds of +languages that allow you to + +express these concepts in +a form similar to that. + +And all it does is it allows us +to talk to the computer in + +this language. + +So everyone good with that? + +Cool? + +All right. + +So when we have these +programming languages, they're + +put together in specific ways. + +So does everyone remember +the term syntax? + +Can anyone tell me what it meant +or means in terms of + +programming languages? + +AUDIENCE: I could guess. + +It is the way that the +string is structured? + +PROFESSOR: Yeah. + +It's the way the parts of the +language are put together. + +So let's say that I take a +very simple statement. + +I'm taking a variable +plus this variable. + +This is a valid piece of +syntax for Python, for + +example, or, say, arithmetic, +or a bunch + +of different languages. + +So this is good. + +I can't write. + +On the other hand, if we say +variable variable plus, this + +isn't valid in Python, +for example. + +It might be valid in another +language, but the syntax of + +Python won't allow this. + +So this is bad syntax. + +So. + +All right. + +So is everyone kind of +understand what syntax is? + +All right. + +What about static semantics? + +Talked about that in class. + +Can anyone give me kind of a +rough view of what that is? + +Can I choose someone? + +All right. + +When we talk about static +semantics, we're talking about + +syntactically valid statements +that mean something. + +So let's say that I have +variable a is equal to 5 and b + +is equal to 2. + +A statement that's syntactically +correct and is + +also meaningful with respect to +static semantics could be + +something like a divided +by 2, right. + +Or a divided by b. + +They're valid statements +syntactically. + +And we know that 5 divided by +2 or a divided by b, they're + +both numbers. + +They mean something. + +On the other hand, let's +say that I had this. + +I'm gonna say that this variable +d is a string 'foo'. + +All right. + +This c divided by d where c is +a number and d is a string, + +that's something that's +not meaningful, right. + +What does a number divided +by a string mean? + +Nothing. + +So that's what we're talking +about with static semantics. + +So bad. + +These two aspects of computer +programs are pretty easy to + +check for a compiler interpreter +because they're + +pretty explicit rules, right. + +The part that we spend most +of our time in is + +the semantic part. + +And this is where the syntax +checks out, the statements are + +meaningful in and of themselves, +but the program as + +a whole, or the whole kind +of recipe, doesn't work. + +So as an example, so this, +as we know is fine. + +That's correct. + +But let's say we have this. + +So a is 6, c is 0. + +I do that, what's +6 divided by 0? + +It's an error. + +But syntactically +this is fine. + +And by static semantics, +this is fine. + +So this is the type of thing +we're talking about with the + +semantic aspects of a program. + +Does it work properly? + +And before I jump into Python, +one tip to keep in mind is + +that when you're writing +programs and you're trying to + +do your problem sets, your +program is very explicit. + +It's not ambiguous. + +So a program will do what +you tell it to do and + +no more and no less. + +And a statement doesn't +mean two things. + +So like if I make the statement +in English, I cannot + +say enough good things or +recommend this person highly + +enough, if you write that out +that can be considered a + +statement with two different +meanings. + +One of them is not too +complimentary. + +All right. + +So when you're writing your +programs, if it's not doing + +what you think it's doing, one +of the skills that you need to + +learn throughout the semester is +to be able to read the code + +and try to follow along in your +mind what's going on. + +It's not magic. + +OK. + +So now we're at Python. + +We're past kind of the generic + +introductory scaffolding stuff. + +Now we're onto something that's +actually gonna be + +meaningful for you for the +next 12, 13, 14 weeks. + +All right. + +So Python is a general +purpose language. + +It's used for all sorts of +things, web development, small + +device development, desktop +programs, et cetera. + +It's an interpreted language, +which means that if I have a + +program, blah, blah, blah, blah, +then Python executes it + +for me straight away. + +Some languages, compiled +languages, have to go through + +a compiler, and then you +have to run them. + +All right. + +It's an extra step. + +The nice thing about having an +interpreted language is that + +as you may changes to the code, +you can instantly see + +what's going on with +your program. + +So. + +See. + +It's got a very simple syntax. + +And it's also very widely used +and has been getting-- + +more and more people have +started using it, oh, for the + +past, say, 15 years. + +So. + +10 years ago when I first heard +about it, it was kind of + +like this little +cute language. + +Now it's kind of blossomed into +this wonderful language + +that everyone uses and loves. + +So. + +Programs in Python, and in all +languages, are sequences of + +expressions. + +So this is getting +back to syntax. + +And these expressions, they are +composed of operands and + +operators and functions. + +So let's say, for example, +this is an expression. + +This is a variable name. + +This is the assignment +operator, and + +this is a string literal. + +When I say operand, what +I'm referring to are + +things in the language. + +That's what a literal +and a variable are. + +And then if I say operator, this +is something that does + +something to things. + +So it's-- + +this is an example of what we +call an assignment operator. + +What it does is it says, take +what I'm referring to my right + +hand side here, create a name +called myvar, and say that + +every time that I reference +myvar, I get this value. + +We'll talk more about +that later on. + +Um. + +Let's see. + +Where am I going? + +So one important thing to know +about Python is that + +everything-- + +so these things-- + +are objects. + +For now, you don't have to get +too familiar with what an + +object is just-- + +if you know anything, especially +for the first quiz, + +this is something to know. + +These objects, they +have types, right. + +So some types that we have +in Python are ints. + +What are examples of +ints or integers? + +What? + +AUDIENCE: 7. + +PROFESSOR: Yeah. + +Just rattle a few off. + +So 7, 0, negative +1, 2, et cetera. + +Now there's another number +type, floats, right. + +So this is what we normally +think of as real numbers. + +But when you're talking about +real numbers on the computer, + +they are kind of dicey to deal +with-- and we'll actually + +cover that later on in the +semester when we talk about + +kind of the inexactness +of these. + +But for now, just know that +these are numbers with like + +decimal points. + +All right. + +OK. + +Where am I going next? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: Actually, +syntactically, yes. + +So one thing that you might +encounter when you're dealing + +with your programs-- this is +kind of off on a tangent-- + +is when you say assign a number +to a variable, when you + +have a literal like this number +here, 0, Python infers + +what type you're +talking about. + +So in this case, it's gonna +create a number, and it's + +gonna call it a type integer. + +All right. + +If it sees this, it's gonna +create this variable, and it's + +gonna have a type of float. + +Now, it might seem like +something minor to you right + +now, but when you start doing +some of the math on problem + +set one, if you divide by an +integer, you might run into + +problems, right, because in +computer-land 5 integer + +divided by 2 integer +is equal to 2. + +Whereas in the real world, +it's equal to that. + +So just be aware when you're +working with numbers that you + +need to be aware of their type, +all right, especially + +when you're talking about the +different operations you can + +do on them. + +So. + +So for these number types, you +have addition, subtraction, + +multiplication, division. + +For integers, exponentiation, +which is + +represented by two asterisks. + +And for integers, modulo. + +And then for floats +plus, minus, same + +thing except no modulo. + +All right. + +So back to the list. + +AUDIENCE: Can I ask +a quick question? + +PROFESSOR: Yes. + +AUDIENCE: Could you explain +why like maybe briefly 5 + +divided by 2 is 2? + +You said in computer-land, +like what? + +Is it doing some sort +of weird rounding? + +Or like why, why is that +different than--? + +PROFESSOR: This is because +the type of the + +variable is an integer. + +And when you say something is +an integer, you're talking + +about only these +numbers, right. + +So 2 and a 1/2 as an integer +doesn't exist. + +It only exists as a float. + +But when you have an operand +like this that takes two + +numbers on both sides, if both +numbers are integers, this + +produces a result that +is an integer. + +So when you have these math +operators, these produce a + +result, right. + +So that result has +a type as well. + +Because I can take that +result and I say c is + +equal to 5 and 1/2. + +C is now a variable +in the language. + +That means that it has +to have a type. + +And Python says that because I +did this operation with two + +integers, I'm gonna give it +a type as an integer. + +And the closest representation +to 2 and 1/2 in + +integer terms is 2. + +AUDIENCE: I thought it +would round up to 3. + +I assumed that it would round +up to [UNINTELLIGIBLE]. + +PROFESSOR: Oh, yeah. + +You're talking about +a separate issue. + +It's not necessarily that it's +closest, but it truncates. + +AUDIENCE: OK. + +PROFESSOR: So when +it converts-- + +yeah, it just truncates +the decimal. + +AUDIENCE: What happens if you +have 5 divided by 2-- + +[UNINTELLIGIBLE]? + +PROFESSOR: So when you get into +stuff like that, Python's + +gonna look at, see it's an +integer and a float, and-- + +this is something that we're +gonna have to actually test + +out when I turn on +the computer. + +It should convert to a float, +but it might not. + +So. + +We'll test that out, actually. + +That's one of the nice things +about Python is that if you + +have a question like that, +you can test it out + +instantaneously. + +So remind me ints divided +by float, and + +we'll demonstrate it. + +OK. + +All right. + +So another data type, string. + +Anyone know what a string +is or can tell me? + +Shout it out. + +Pantomime it. + +AUDIENCE: Sequence +of characters. + +PROFESSOR: OK. + +So it's something like this. + +All right. + +And you can-- + +does anyone mind if +I erase this? + +So in Python, you can specify +strings a couple ways. + +One is with single quotes +on the sides. + +And the other is with +double quotes. + +This is useful, for example, +if you need to embed quotes + +inside a string. + +So if I need to, say, have this +as a quoted string, I + +would have single quotes on the +outside and then double + +quotes on the inside, +or vice versa. + +I could do double quotes +and then single quotes. + +The point is that Python needs +to know when and where the + +string starts and where +the string ends. + +We good? + +All right. + +AUDIENCE: [UNINTELLIGIBLE]. + +PROFESSOR: So if you put that? + +If you write this, Python's +gonna call that a string. + +It's a string that contains +the character two, though. + +All right. + +I guess you're asking +because of the input + +with the problem set? + +AUDIENCE: --divide that by a +string, by an integer that + +would [UNINTELLIGIBLE]. + +PROFESSOR: So in your program, +there's a point where you have + +to enter in numbers +for problem set 1. + +Oh, you didn't start? + +Well there is a place where +you have to enter numbers. + +So raw_input, for example, is +gonna return a variable, and + +the type of this is +gonna be a string. + +So if you need to use it as an +integer or as a float, you can + +convert it. + +So now this is an integer, and +you can do math with it. + +Or you can also say-- + +Does that make sense? + +That's something that'll be +useful in your problem set. + +So just FYI. + +All right. + +Another data type, Boolean. + +Does anyone know what +a Boolean is? + +AUDIENCE: [UNINTELLIGIBLE]. + +PROFESSOR: What's that? + +AUDIENCE: It's like an +if-then statement? + +PROFESSOR: It has to +do with if-then + +statements, but it's a variable. + +It's a type that only has two +values, true or false. + +OK. + +And we'll talk about this, all +of these, when I start talking + +about operations on them. + +Last one that you need to know +of right now is the none type. + +The way to think about none +is that it's sort + +of like dark matter. + +It's there. + +We know it's there. + +It holds a place, but we can't +do anything with it. + +It's there just so that you know +that there's a variable + +that should refer to something +but that something doesn't + +exactly exist. + +OK. + +You'll see more of it. + +But it's nothing, +but it's there. + +And then later on +in the semester, + +there's other data types. + +I mean, there's a lot of data +types, but these are the big + +ones that you need to +know right now. + +Other data types that we might +look at are lists, tuples, and + +dictionaries. + +These are other major data +types in Python. + +You don't need to know them +right now 'cause Professor + +Guttag will go over +them in lecture. + +But just keep them +in your brain. + +OK. + +So we've already talked about +the operations that we can do + +on numbers. + +We can also do operations +on strings. + +So we can do something +called concatenation. + +So concatenation is just +a big word for + +sticking two things together. + +So if I have s1 and s2 and I +want to concatenate them to + +together, I use the +plus operator. + +So the other thing, too, that I +want to point out is that we + +have a plus operator for ints. + +We got a plus operator +for float. + +We've got one for strings. + +I don't think they work for +bools, but they work for lists + +and tuples. + +This is what's known as an +overloaded operator. + +So it changes shape or changes +its behavior depending on the + +data types of its operands. + +So that's why when you're +dividing an ints by a float, + +some languages will convert +it to a float for you. + +Other languages will +convert to an ints. + +It's something that varies. + +That's why I'm not sure of +my answer right now. + +So. + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: No. + +If your computer blows +up in your face, + +then that's an issue. + +That's a separate issue. + +All right. + +So some other operations that +we have, and they relate to + +Booleans, are comparison +operations. + +What these mean are these take +two operands and compare them. + +So if I want to see if-- + +if I say a less than b and a is +2 and b is 3, then this is + +gonna return true. + +The value of this expression +becomes true. + +And if I say a greater than +b, obviously it's + +gonna be false, right. + +And all of these operators +work in + +basically the same way. + +They take two operations, +and they give you a + +Boolean value back. + +All right. + +Any questions on that? + +AUDIENCE: So are Boolean values +always true or false? + +PROFESSOR: Always +true or false. + +And I'm actually gonna +get to that now. + +So Boolean values-- and this is +kind of the last major one + +we're gonna talk about-- + +have three operators, +AND, OR, and NOT. + +Actually, these should +be lowercase. + +These, AND and OR, take two +operands, NOT takes one. + +And what they do is if you have +something like a is true, + +b is true, c is false, if you +say like a AND b, then this + +entire expression is gonna +return true, right. + +If I say a AND c, this +will be false. + +AND returns true, if and only +if both operands are true, + +false otherwise. + +If you say a OR c, OR returns +true if both operands or one + +operand is true. + +So if any of them are true +or both are true. + +If they're both false, then +it returns false. + +And NOT, all this does is if I +say NOT a, it'll return false. + +It reverses it. + +Now we can combine +these together. + +So these are very simple +expressions, but we can also + +combine them. + +So we can say like a +AND b OR c, right. + +So if both a amd b are true, +then this becomes true. + +And then this entire expression +becomes true if + +this part is true or +this part is true. + +So you can build up pretty +complicated expressions. + +And then the way that they +relate to these logical + +operators is, remember, these +take numbers on either side + +and they produce +Boolean values. + +So if I have-- + +I can say d is less than e. + +This is gonna give me a Boolean +value, right, which I + +can then use the AND operator +on and I can say-- + +So what this does is it says if +d is less than e and e is + +less than f, then return true. + +This, by the way, would check to +see that these numbers are + +in order, so 3, 4, 5, as +opposed to 5, 4, 3. + +So is everyone good +on all that? + +Did I lose anyone? + +No questions? + +All right. + +So the last couple of things and +then I'm gonna turn on the + +computer and actually walk +through some code with you and + +we'll be done for the day. + +So this is kind of the crash +course in basic syntax for our + +basic types for Python. + +So there were three-- + +So what we have now is a way to +create programs that run in + +a straight line, right. + +So can anyone give me kind of a +synopsis of what a straight + +line program is? + +AUDIENCE: Go down +line by line. + +PROFESSOR: What's that? + +AUDIENCE: Everything one-- +go down line by line. + +PROFESSOR: Go down line by +line, do everything once. + +All right. + +The problem is that this +doesn't allow us to do + +anything, right. + +So we have branching. + +This is implemented +by something + +called an IF statement. + +Now, the way you use an +IF statement is-- + +all right. + +This is the full version +of the IF statement. + +It's saying, if this condition +is true, I'm gonna execute the + +code in this block. + +If this condition is true, if +this condition is false and + +this condition is true, +then I'm gonna + +execute the code here. + +And if none of those +were true, then I + +execute what's here. + +You don't need to have an ELIF, +and you don't need to + +have an ELSE. + +You can just have an IF +or an IF and an ELSE. + +So the three versions +of this branching-- + +Now when I, just by way of +explanation, when I draw like + +a line like that, I'm talking +about a block of code. + +Can anyone tell me how Python +represents blocks of code? + +AUDIENCE: Indents? + +PROFESSOR: Yeah. + +So indentation, right. + +We kind of talked about +that on Thursday. + +So blocks of code are chunks +of code that belong kind of + +logically together. + +So what this saying is that if I +execute this, all this block + +is gonna get executed, all this +block is going to get + +executed, et cetera. + +So if I were to represent this +pictorially, then this is kind + +of the main part of the program +and then this is the + +if statement and the block. + +And then it goes back +to whatever code + +is down here, right. + +If I represent this +pictorially, this + +would be the true part. + +So this part of code, +this would be else. + +And then this part would +be multiple excursions. + +So it would look a little +bit like a tree. + +All right. + +So different branches for the +different bits of code. + +Is everyone puzzled on that? + +Or anyone puzzled on that? + +OK. + +And there was a last +bit of flow control + +that we talked about. + +What was it? + +So if we want to do something +multiple times? + +AUDIENCE: Iterations or loops + +PROFESSOR: Iterations +or loops, right. + +So it's called a loop because +it looks like a loop in the + +code, right. + +And there's two variants. + +There's a WHILE loop and +there's a FOR loop. + +A FOR loop is when you want +to iterate over a + +finite set of elements. + +So what this FOR loop does is +it says I'm gonna take-- + +this is the range function, +so we'll talk about this + +a little bit later. + +But all it does is it gives me +all the numbers from 1 to 9. + +It goes 1 past. + +So. + +But you don't need to +know it just yet. + +What this is telling Python, +though, is that we're gonna + +execute this block of code +9 times, all right. + +And on each iteration through +this block of code, we're + +gonna set i to 1, and then set +it to 2, set it to 3, 4, 5, 6, + +7, 8, 9, 10. + +Anyone lost by that? + +We'll see an example of +it pretty shortly. + +And then the last one +is a WHILE loop. + +A WHILE loop executes as long +as a condition is true. + +So it's useful-- + +don't want to do that. + +It's useful when you're not +necessarily iterating over + +this finite set of elements or +you don't necessarily know how + +many times you need to execute +a specific loop. + +You just know that you need to +keep executing this code while + +something is true. + +And we'll see an example +of that pretty quickly. + +So I basically shotgun blasted a +whole bunch of stuff at you. + +Is there anything that people +want me to touch on before I + +pull down the screen and we +start looking at code? + +All right. + +So has everyone been able +to get Python set up? + +All right. + +So you'll know that this is +the editor window, right. + +So what we use to edit +longer scripts in? + +And you know that this is +the interactive prompt. + +Before I forget, let's see what +happens if I divide the + +integer 5 by the float 2. + +So Python does what you would +hope it would do. + +It turns it into a float. + +If I do this, though, +it gives me 2. + +All right. + +So it's an easy way to test. + +So we've got two chunks +of code here that + +I want to go over. + +One of them, you've +already seen. + +It's the program that tries +to find the cube root of a + +perfect cube. + +And why don't we just walk +through it and read the code? + +All right. + +So here's that raw_input +function + +that I told you about. + +Now, it's gonna take a string +and it's gonna print the + +string out on the screen +and it's gonna + +say enter an integer. + +And, comment this out. + +So let's enter-- + +what's a perfect cube? + +All right, the return type of +raw_input is a string, right. + +So that int will convert to x. + +Now, here's an example of +a loop, the WHILE loop. + +And because we don't have +knowledge of what the user's + +gonna input when the program +is run, a while loop is an + +appropriate kind of control +loop to use, right. + +Because we can test a condition +where our guess, + +which is what's represented by +ans, if we cube it, is it + +still less than x. + +All right. + +I explained that a little +bit incorrectly. + +What we're doing here is we're +making a guess, and we're + +calling it ans right now, +and we're gonna set it + +initially to zero. + +And then we're gonna enter +this WHILE loop and we're + +gonna say we're gonna take +answer and we're gonna + +multiply it three times. + +We're gonna cube it. + +And if the value of ans cubed +is less than whatever input + +the user gave us, then we're +gonna keep looping. + +And on each loop, we're gonna +increase the value of our + +guess for ans, right. + +And if it turns out that x is a +perfect cube, eventually, by + +just iterating through all the +integers from 1 to whatever, + +whatever the cube root of x is, +we will find the answer. + +And we'll know we find the +answer because answer cubed is + +going be less than x. + +Now, can anyone tell me +why we have abs here? + +AUDIENCE: The absolute value. + +PROFESSOR: Right. + +So let's say that the user +entered in like negative 27. + +It still has a cube, right. + +It's still negative 3. + +But the way that we set up our +loop, if we were to take this + +out, the program would just +continue executing forever. + +Well, for actually a very, +very long time, but-- + +the universe would die +before this finished. + +So we have this absolute +value here. + +Is anyone puzzled by this? + +Do I need to belabor +the point? + +OK. + +So eventually I've entered +27 and we can actually-- + +a good way to kind of check +ourselves is to print out + +diagnostic input. + +So if guess is 1, that's not-- + +1 cubed is obviously not 27. + +2 cubed is not 27. + +3 cubed is 27. + +And when we get to that point, +we leave the loop. + +And now we're down in +this bit of code. + +All right. + +Now, because we're asking for +cube roots, we need to check + +the condition for when the-- + +sorry, I'm kind of +mixed up here. + +Sorry. + +So when we exit the WHILE loop, +if we've had a number + +that's not a perfect cube, then +we know that the value + +the answer stopped on is not +going to equal the cube of it, + +by way of explanation. + +So my last guess +3 cubed is 27. + +Let's run it again. + +Let's say that I +have 20, right. + +So what happens is +it gets to 4. + +So 4 cubed is 64, right. + +That's obviously not 28. + +And that's what this +condition checks. + +And so it knows that if it gets +to that point, it's not a + +perfect cube. + +Now, this ELIF statement here +says, OK, so if this turns out + +to be true, that means that +it wasn't a perfect cube. + +But let's say that it was a +perfect cube, this will be + +true, and Python will then start +to look at this and say, + +well, let's look at this if +condition, or actually-- + +I'm sorry. + +This condition will be false if +it's a perfect cube, right. + +And Python will say, OK, look +at the next part of the + +IF-ELIF statement and will say, +well, was x less than 0? + +What it's doing here, it's +checking whether or not we've + +entered a negative +number or not. + +So if we enter negative 27, what +it would do is it would + +to enter this branch, and then +it would negate whatever + +answer it got. + +Because we found the answer +for a positive + +perfect cube, right. + +Did I break it? + +We are having technical +difficulties. + +Oh, OK. + +I'm not sure what +happened there. + +So anyway. + +So we go about trying to find +the cube root of 27, which is + +the absolute value of 27. + +And we, of course, find it. + +It's 3. + +But then because we've entered +a negative number, Python's + +gonna enter this branch and +negate whatever answer we got. + +Because we know that in order +for it to be negative, then it + +would have to have been a +negative number, right. + +Is anyone lost? + +Everyone good? + +AUDIENCE: Do you need an +exclamation mark for the--? + +PROFESSOR: Oh, this one? + +AUDIENCE: Yeah. + +PROFESSOR: So this is one of +the comparison operators. + +This stands for not equal to. + +So if I have-- + +do a little Python work here-- +if I have a is equal to 5 and + +b is equal to 6, if I say a is +double equal, that's gonna + +check and see if they're +the same value. + +Obviously, they're not, so +it's gonna return false. + +On the other hand, if I say +not equal-- or bang equal + +sometimes we call-- + +this will return true. + +OK. + +Any other questions? + +AUDIENCE: The one that you did +28 for, shouldn't it not print + +the cube root of 28 is 4? + +PROFESSOR: Oh. + +Yeah. + +So yeah. + +Should it be indented? + +Because if we indented +here, right, then + +what's gonna happen? + +It's only gonna print +out the cube root + +for negative numbers. + +So what-- + +what's that? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Well, again, if we +put an ELSE statement, then it + +won't print out the cube root +for negative numbers. + +What we could do, and this is +kind of a hackish way, is + +write it like this. + +But that's kind of ugly, +right, because you're + +repeating yourself. + +And one thing about computer +programmers is that we are the + +laziest people on the +face of the earth. + +Like, we'll spend 20 hours +writing a program to do + +something in five minutes that +we could have originally done + +in 10 minutes. + +It's just our nature. + +So anyway. + +So we're repeating ourselves. + +And while I'm speaking, +this is the + +solution I came up with. + +If I were to go back and rewrite +this, I'd probably + +make it a little bit +less convoluted. + +So maybe, let's try this. + +So we're gonna check if we +were successful, and then + +we're gonna check if +x is less than 0. + +Now we're not repeating +ourselves. + +And we catch all the cases. + +So let's make sure that my fix +works because oftentimes when + +you write programs, you'll +introduced bugs of your own. + +So we've tested when +it is a cube. + +Let's test it when it's not. + +OK. + +So there we fixed it, I think. + +One thing about computer +programs is that this is a + +very simple case, but for +longer, more complicated + +programs, it's almost +impossible to get + +out all of the bugs. + +But in this case, pretty +confident that we were + +successful, right. + +So does anyone else have +any other questions + +on this bit, right? + +All right. + +The last thing that I'm gonna go +over is something called a + +fizzbuzz program. + +This is just a silly +little program. + +This is the English +specification. + +And this is kind of a first +instance of where we're gonna + +take English and kind of break +it down into code, figure out + +how to break it up, chunk it +up, and abstract it into + +something that actually works. + +So the problem is to write a +program the prints the numbers + +from 1 to 100, but for multiples +of three, print fizz + +instead of the number. + +And for multiples of +5, print buzz. + +And if there are multiples are +both 3 and 5, print fizzbuzz. + +So if it says numbers from 1 to +100, when you see something + +like this when you're trying +to figure out how to write + +your programs, the first thing +that should go off in your + +mind is, I probably need a for +loop because I'm iterating + +over a set of numbers. + +So we happen to know the +numbers 1 to 100. + +And here's a range +function again. + +And we'll talk about range +next week most likely. + +And all we're gonna do is first +we're gonna get the + +string value of this number. + +So remember how earlier you +asked if, or one of the + +students asked, if we had a +number in the string, if that + +was a number or not? + +So like this. + +That's what that STR +function does. + +So if I have a variable a is +equal to 1, I can say s is + +equal to STR a, and s is +now gonna be that. + +All right. + +And then what I'm gonna do here +is I'm gonna check the + +integer value, so i, and +see if it's evenly + +divisible by 3 or 5. + +And the way that I +checked that is I + +use a modulo operator. + +That's what that percent +sign is. + +What this operator does is it +takes two integer values and + +it returns the remainder after +you've divided the left + +integer by the right integer. + +So if I have 6 modulo 3, +what's that gonna be? + +It should be 0, right, because +you can divide 6 evenly by 3. + +The other hand, if I say 5 +modulo 3, then that's going to + +be 2, right. + +Yeah, I had to think about +it for a second. + +OK. + +So that's all this does. + +And these are two expressions +that return a + +Boolean value, right. + +Because this modulo operation +is gonna return an integer, + +and I'm gonna use the equality +operator to compare it to a + +number, another integer, 0, +and that's gonna give me a + +Boolean value. + +This expression also gives +me a Boolean value. + +And then I'm gonna combine +them into-- + +using the or operator +for Boolean values-- + +into a larger expression. + +And then if this is true, then +I know that I'm gonna have to + +at lease print fizz, +buzz, or fizzbuzz. + +Because I'm not gonna print +the number, right, because + +it's a multiple of 3 or 5. + +And so all this code does is +just figures out if it's + +evenly divisible by 3, then +I know I print fizz. + +So I'm gonna concatenate my +final string onto it. + +And then if it's evenly +divisible by 5, then I know I + +need to print buzz. + +So then I'm gonna attach +buzz onto my output. + +And then I'm just gonna print +whatever I'm left over with. + +So to see this in action +because we are way out + +of time right now. + +So 1, 2, fizz, 4, buzz, +6, fizz, 7, 8. + +Then we have fizzbuzz for 15. + +So it seems to work. + +Everyone follow that? + +We good? + +So I'm done for this +recitation. \ No newline at end of file diff --git a/8Dxo4LPK_9w.txt b/8Dxo4LPK_9w.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1d9be36ebeecd8096d3d175562881227730a5c1 --- /dev/null +++ b/8Dxo4LPK_9w.txt @@ -0,0 +1,540 @@ +PROFESSOR: That's how +it looks, a resonance. + +You can see it basically +in the phase shift. + +And great increase of the +phase of almost minutely pi + +over a very small +change of energy. + +And it should [INAUDIBLE] +with a very big [INAUDIBLE].. + +So this is how it looks. + +And I want to now +proceed, after if there + +are some questions, +of how do we search + +for residences a little +more mathematically rather + +than plotting them. + +How could I write an +equation for a resonance. + +Cannot say, oh, the +phase changes fast. + +Well, that's not a very +nice way of saying it. + +It's good. + +It's intuitive. + +But we should be +able to do better. + +So how do I find resonances? + +So let's model +resonances a little bit. + +How do we find resonances? + +So let's model this behavior. + +By that is writing +a formula that + +is simple enough that seems +to capture what's happening. + +And that formula's +going to inspire + +us to think of resonances +perhaps a little more clearly. + +So suppose you have a +resonance near k equal alpha. + +I claim the following +formula would be a good way + +to represent the resonance? + +We would say that tan +delta is equal to beta + +over alpha minus k. + +Or-- yeah, we would say that. + +[INAUDIBLE] Or if you wish, +delta is tan minus 1 of beta + +over alpha minus k. + +Why is that reasonable? + +It's a little surprising, +but not that surprising. + +You see that-- delta is +equal to minus pi over 2. + +The tangent of delta +goes to infinity. + +So there's something +going on here in which you + +have this property. + +So let's plot this. + +So let's plot beta +over alpha minus k. + +You need a clock +to understand this. + +So this is k, and we're +plotting this quantity. + +Well, it's going to go +crazy at k equal alpha. + +That we know. + +When k is less than +alpha, I'm going + +to assume that alpha +and beta are positive. + +They both have units of k. + +And when k is less than +alpha-- we begin here-- + +then this denominator +is positive, + +the numerator is positive, +ratio is positive. + +It's small, maybe. + +And then suddenly, +when k reaches alpha + +it goes to infinity. + +So it's going to be like that. + +Now, it actually +is true that when + +k differs by alpha by +beta, it reaches value 1. + +So here is alpha minus beta. + +That point it reaches value 1. + +So if I want this +thing to be very sharp, + +I need beta to be small +so that it's little + +until it reaches beta within-- + +distance beta within alpha, +and then it shoots up. + +So I want beta to be +small for sharp behavior. + +On the other hand here, +it goes the other way. + +It goes from minus +infinity back to 0, + +and has value minus +1 at alpha plus beta. + +So within minus beta, and +beta off of the center + +alpha, most of +the things happen. + +If we plot now the +tangent of this, + +or the arctangent of this, tan +minus 1 of beta, alpha minus k, + +well, if the tangent of +an angle is very little, + +the angle can be taken +to be very little. + +At this point, it +will reach pi over 2, + +so the angle is little, +will go to pi over 2, + +and then quickly becomes +larger than pi over 2, + +you're thinking tangents. + +So the tangent is going up, +is blowing up at pi over 2. + +Then continuously, it +goes to minus pi over 2, + +and then continuously goes +to 0 so it reaches pi. + +So this is the +behavior of delta. + +Delta is this tan minus +1 of beta over that. + +And delta is doing +the right thing. + +It's doing this +kind of behavior. + +There is a shift. + +I could add a constant +here to produce this shift, + +but it's not important +at this moment. + +The resonance is +doing this thing, + +up to a total shift +of pi that doesn't + +change the tangent of an angle. + +So this is one way +of modeling what's + +happening to the phase +shift near our resonance. + +So let's explore +it a little more. + +I can do a couple +of calculations. + +For example, I can compute +what is d delta dk at k + +equals alpha. + +That's should be +a nice quantity. + +Is a derivative of the face. + +At the resonance, +at the position + +alpha of the resonance. + +So here's delta, here +is k, and there's + +the derivative of this k. + +And how should it be? + +Well, basically, the +phase changes by amount pi + +over a distance beta or 2 beta. + +So this must be a +number divided by beta. + +You can calculate this +derivative from this equation. + +It's a nice exercise. + +It's actually just 1 over beta. + +That's a result. 1 over beta. + +The other quantity that +is nice to understand + +is how does this +scattering amplitude + +behave near the resonance. + +So what is the +value of as squared? + +Oh, that's the absolute +value of psi s squared, + +which is sine squared delta. + +That's the same +thing as As squared. + +Well, you know what is +the tangent of delta? + +A little trigonometric play +should be able to do it, + +and can give you the +sin squared delta. + +And here is the answer. + +It's beta squared over +beta squared plus alpha + +minus k squared. + +Kind of a nice, +almost bell shape. + +Of course, it's polynomial, +but it looks a little + +like just a nice symmetric +shape around alpha equal k. + +Now, this division is so famous +it has been given a name. + +It's called the +Breit-Wigner distribution. + +Breit-Wigner. + +But it's described as the +Breit-Wigner distribution, + +and it's usually referring +to terms of energy. + +Of energy, not momentum. + +So-- and it's-- + +what should happen to +scattering amplitude in general + +when you have a resonance. + +So the way to do +this calculation now + +is to say, well, what +is alpha minus k? + +Let's try to relate it to the +energy minus the energy at k + +equal alpha. + +Well, this is h +squared k squared + +over 2 m minus h squared +alpha squared over 2 m, + +which is h squared over 2 m, +k squared minus alpha squared. + +On the other hand, I have +here alpha minus k squared. + +I don't have k squared +minus alpha squared. + +So-- approximations. + +if the resonance is narrow +enough, if beta is small, + +let's do an approximation. + +We do h squared over-- + +everybody knows +this approximation, + +shouldn't be afraid of doing it. + +It's alpha-- how +could I write it-- + +k minus alpha +times k plus alpha. + +And the approximation is that +all the interesting thing + +comes from the difference +between k and alpha, + +how close k is to alpha. + +So when k is close to +alpha, all the dependence + +is going to be here. + +This is going to be about 2 +alpha when k is near alpha. + +And if it's a little +more than that, + +it doesn't matter, +because it's [INAUDIBLE].. + +So this could be +approximated to 2 alpha, + +and therefore this becomes h +squared alpha over m times k + +minus alpha. + +So that's a little help. + +Then size of s squared, +doing a little more + +of algebra with the +constants there. + +Probably you want to +do it with two lines. + +It's tricky. + +It's really simple. + +It's always written +in this form-- + +1 over 4 gamma squared over +e minus e alpha squared + +plus 1 over four gamma +squared, and that's + +the so-called +Breit-Wigner distribution. + +And gamma is a +funny constant here. + +We'll try to +understand it better. + +2 alpha beta h squared over m. + +It has to be something that +depends on alpha and beta, + +because after all, +we weren't modeling + +the resonance with alpha beta. + +So this curve is very famous. + +That's the distribution of +the scattering amplitude + +over energies whenever +you have a resonance. + +So we should plot it. + +You have an e alpha. + +You have an e alpha +plus gamma over 2 + +and e alpha minus gamma over 2. + +But the energy minus e alpha +is equal to the gamma over 2, + +you get the gamma squared over +4 so the total amplitude goes + +down to 1/2 of the +usual amplitudes. + +When the energy is equal +to e alpha, you get 1. + +1 for psi s squared. + +But when the energy differs +from e alpha by gamma over 2, + +you get half. + +So-- actually, I'm not +sure of the deflection + +point, where it is. + +Probably not there. + +Or is it there? + +I don't know. + +I drew it as if it is there. + +So that's the distribution, and +the width over here is gamma. + +So gamma is called the +width at half power, + +or at half intensity. + +Yeah. + +Width-- the half width +of the distribution. \ No newline at end of file diff --git a/8MyPd4F7y54.txt b/8MyPd4F7y54.txt new file mode 100644 index 0000000000000000000000000000000000000000..e57871b25a1b44ba18d390b8e6433ada40325e91 --- /dev/null +++ b/8MyPd4F7y54.txt @@ -0,0 +1,8451 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu the end of the last class I + + align:start position:0% +ocw.mit.edu the end of the last class I + + + align:start position:0% +ocw.mit.edu the end of the last class I +mentioned that + + align:start position:0% +mentioned that + + + align:start position:0% +mentioned that +uh this invasion of the end brain by + + align:start position:0% +uh this invasion of the end brain by + + + align:start position:0% +uh this invasion of the end brain by +visual Pathways uh we know that mostly + + align:start position:0% +visual Pathways uh we know that mostly + + + align:start position:0% +visual Pathways uh we know that mostly +it even though there was a direct + + align:start position:0% +it even though there was a direct + + + align:start position:0% +it even though there was a direct +pathway it was very small the one + + align:start position:0% +pathway it was very small the one + + + align:start position:0% +pathway it was very small the one +through the genicular body very small + + align:start position:0% +through the genicular body very small + + + align:start position:0% +through the genicular body very small +early on major Roots into the end braan + + align:start position:0% +early on major Roots into the end braan + + + align:start position:0% +early on major Roots into the end braan +came they began at the tectum also the + + align:start position:0% +came they began at the tectum also the + + + align:start position:0% +came they began at the tectum also the +pretectal area which projected into + + align:start position:0% +pretectal area which projected into + + + align:start position:0% +pretectal area which projected into +thalamic areas which then projected to + + align:start position:0% +thalamic areas which then projected to + + + align:start position:0% +thalamic areas which then projected to +the end brain and so I'm asking I asked + + align:start position:0% +the end brain and so I'm asking I asked + + + align:start position:0% +the end brain and so I'm asking I asked +there at the end of the class what what + + align:start position:0% +there at the end of the class what what + + + align:start position:0% +there at the end of the class what what +what were the Adaptive advantages of + + align:start position:0% +what were the Adaptive advantages of + + + align:start position:0% +what were the Adaptive advantages of +that why would it invade the + + align:start position:0% +that why would it invade the + + + align:start position:0% +that why would it invade the +inbre + + align:start position:0% +inbre + + + align:start position:0% +inbre +uh and first I I try to give an + + align:start position:0% +uh and first I I try to give an + + + align:start position:0% +uh and first I I try to give an +anatomical answer it's a it's a way to + + align:start position:0% +anatomical answer it's a it's a way to + + + align:start position:0% +anatomical answer it's a it's a way to +provide better information to this trium + + align:start position:0% +provide better information to this trium + + + align:start position:0% +provide better information to this trium +remember visual information could reach + + align:start position:0% +remember visual information could reach + + + align:start position:0% +remember visual information could reach +the + + align:start position:0% +the + + + align:start position:0% +the +striatum uh directly from the older + + align:start position:0% +striatum uh directly from the older + + + align:start position:0% +striatum uh directly from the older +phals but those structures weren't + + align:start position:0% +phals but those structures weren't + + + align:start position:0% +phals but those structures weren't +precisely + + align:start position:0% +precisely + + + align:start position:0% +precisely +topographic you know and the striatum + + align:start position:0% +topographic you know and the striatum + + + align:start position:0% +topographic you know and the striatum +wasn't a structure that made really good + + align:start position:0% +wasn't a structure that made really good + + + align:start position:0% +wasn't a structure that made really good +topography as easy to form in evolution + + align:start position:0% +topography as easy to form in evolution + + + align:start position:0% +topography as easy to form in evolution +now that's my + + align:start position:0% +now that's my + + + align:start position:0% +now that's my +interpretation obviously it that + + align:start position:0% +interpretation obviously it that + + + align:start position:0% +interpretation obviously it that +happened mostly in the cortex in the + + align:start position:0% +happened mostly in the cortex in the + + + align:start position:0% +happened mostly in the cortex in the +cortex you you you get this highly + + align:start position:0% +cortex you you you get this highly + + + align:start position:0% +cortex you you you get this highly +topographic mapping of the visual world + + align:start position:0% +topographic mapping of the visual world + + + align:start position:0% +topographic mapping of the visual world +and those Pathways came by way of the + + align:start position:0% +and those Pathways came by way of the + + + align:start position:0% +and those Pathways came by way of the +midbrain and directly from the + + align:start position:0% +midbrain and directly from the + + + align:start position:0% +midbrain and directly from the +geniculate + + align:start position:0% +geniculate + + + align:start position:0% +geniculate +body so that enabled a lot better Acuity + + align:start position:0% +body so that enabled a lot better Acuity + + + align:start position:0% +body so that enabled a lot better Acuity +uh + + align:start position:0% + + + + align:start position:0% + +for the learning that the end brain was + + align:start position:0% +for the learning that the end brain was + + + align:start position:0% +for the learning that the end brain was +capable of especially by means of its + + align:start position:0% +capable of especially by means of its + + + align:start position:0% +capable of especially by means of its +Pathways to where two different places + + align:start position:0% +Pathways to where two different places + + + align:start position:0% +Pathways to where two different places +to the striatum rehabit + + align:start position:0% +to the striatum rehabit + + + align:start position:0% +to the striatum rehabit +learning and to the hippocampal + + align:start position:0% +learning and to the hippocampal + + + align:start position:0% +learning and to the hippocampal +formation we're learning about where Lo + + align:start position:0% +formation we're learning about where Lo + + + align:start position:0% +formation we're learning about where Lo +locations of the animal in the + + align:start position:0% +locations of the animal in the + + + align:start position:0% +locations of the animal in the +environment not the locations of other + + align:start position:0% +environment not the locations of other + + + align:start position:0% +environment not the locations of other +animals the location of the animal whose + + align:start position:0% +animals the location of the animal whose + + + align:start position:0% +animals the location of the animal whose +brain we're talking about okay + + align:start position:0% + + + + align:start position:0% + +so the cognitive functions + + align:start position:0% +so the cognitive functions + + + align:start position:0% +so the cognitive functions +were that root to the hippocampus for + + align:start position:0% +were that root to the hippocampus for + + + align:start position:0% +were that root to the hippocampus for +Place information is a major part of our + + align:start position:0% +Place information is a major part of our + + + align:start position:0% +Place information is a major part of our +cognitive ability our memory + + align:start position:0% +cognitive ability our memory + + + align:start position:0% +cognitive ability our memory +formation but also another kind of + + align:start position:0% +formation but also another kind of + + + align:start position:0% +formation but also another kind of +memory it provided a visual root to the + + align:start position:0% +memory it provided a visual root to the + + + align:start position:0% +memory it provided a visual root to the +amydala which is really part of the + + align:start position:0% +amydala which is really part of the + + + align:start position:0% +amydala which is really part of the +striatum in the way I see it sort of a + + align:start position:0% +striatum in the way I see it sort of a + + + align:start position:0% +striatum in the way I see it sort of a +at least a sort of a codal output of a + + align:start position:0% +at least a sort of a codal output of a + + + align:start position:0% +at least a sort of a codal output of a +striatum it functions like a + + align:start position:0% +striatum it functions like a + + + align:start position:0% +striatum it functions like a +striatum + + align:start position:0% +striatum + + + align:start position:0% +striatum +for the learning of avoidance and + + align:start position:0% +for the learning of avoidance and + + + align:start position:0% +for the learning of avoidance and +approach okay and then also binocular + + align:start position:0% +approach okay and then also binocular + + + align:start position:0% +approach okay and then also binocular +vision which we won't talk very much + + align:start position:0% +vision which we won't talk very much + + + align:start position:0% +vision which we won't talk very much +about now but that was important too + + align:start position:0% +about now but that was important too + + + align:start position:0% +about now but that was important too +because the neocortex made made possible + + align:start position:0% +because the neocortex made made possible + + + align:start position:0% +because the neocortex made made possible +a lot better binocular vision by + + align:start position:0% +a lot better binocular vision by + + + align:start position:0% +a lot better binocular vision by +especially stereoptic + + align:start position:0% +especially stereoptic + + + align:start position:0% +especially stereoptic +stereopsis slight difference in the + + align:start position:0% +stereopsis slight difference in the + + + align:start position:0% +stereopsis slight difference in the +visual image from the two eyes because + + align:start position:0% +visual image from the two eyes because + + + align:start position:0% +visual image from the two eyes because +the information from right eye and left + + align:start position:0% +the information from right eye and left + + + align:start position:0% +the information from right eye and left +eye is kept separate all the way up to + + align:start position:0% +eye is kept separate all the way up to + + + align:start position:0% +eye is kept separate all the way up to +the cortex where then you can combine + + align:start position:0% +the cortex where then you can combine + + + align:start position:0% +the cortex where then you can combine +that information get + + align:start position:0% + + + + align:start position:0% + +depth at the end of that chapter 20 I + + align:start position:0% +depth at the end of that chapter 20 I + + + align:start position:0% +depth at the end of that chapter 20 I +mentioned I believe it's in chapter 20 I + + align:start position:0% +mentioned I believe it's in chapter 20 I + + + align:start position:0% +mentioned I believe it's in chapter 20 I +mentioned some of the expansions and + + align:start position:0% +mentioned some of the expansions and + + + align:start position:0% +mentioned some of the expansions and +specializations of the visual + + align:start position:0% +specializations of the visual + + + align:start position:0% +specializations of the visual +system mainly mid-brain tectum + + align:start position:0% +system mainly mid-brain tectum + + + align:start position:0% +system mainly mid-brain tectum +and the phm cortical projections of the + + align:start position:0% +and the phm cortical projections of the + + + align:start position:0% +and the phm cortical projections of the +visual system the midbrain Tech the + + align:start position:0% +visual system the midbrain Tech the + + + align:start position:0% +visual system the midbrain Tech the +these are the two major structures and + + align:start position:0% +these are the two major structures and + + + align:start position:0% +these are the two major structures and +we're going to look at that + + align:start position:0% +we're going to look at that + + + align:start position:0% +we're going to look at that +today uh just one second here uh and + + align:start position:0% +today uh just one second here uh and + + + align:start position:0% +today uh just one second here uh and +we'll be talking a lot more about + + align:start position:0% +we'll be talking a lot more about + + + align:start position:0% +we'll be talking a lot more about +transcortical Pathways in the following + + align:start position:0% +transcortical Pathways in the following + + + align:start position:0% +transcortical Pathways in the following +class and then I don't deal in the book + + align:start position:0% +class and then I don't deal in the book + + + align:start position:0% +class and then I don't deal in the book +with the tremendous differences among + + align:start position:0% +with the tremendous differences among + + + align:start position:0% +with the tremendous differences among +animals in retinas you develop many + + align:start position:0% +animals in retinas you develop many + + + align:start position:0% +animals in retinas you develop many +retinal specializations and + + align:start position:0% +retinal specializations and + + + align:start position:0% +retinal specializations and +animals you don't need larger eyes just + + align:start position:0% +animals you don't need larger eyes just + + + align:start position:0% +animals you don't need larger eyes just +to get a larger retina and get more + + align:start position:0% +to get a larger retina and get more + + + align:start position:0% +to get a larger retina and get more +retinal gangling cills and more Acuity + + align:start position:0% +retinal gangling cills and more Acuity + + + align:start position:0% +retinal gangling cills and more Acuity +that + + align:start position:0% +that + + + align:start position:0% +that +way what else you need large eyes + + align:start position:0% + + + + align:start position:0% + +for bring in more light why do you buy a + + align:start position:0% +for bring in more light why do you buy a + + + align:start position:0% +for bring in more light why do you buy a +camera with a big lens rather than a + + align:start position:0% +camera with a big lens rather than a + + + align:start position:0% +camera with a big lens rather than a +small lens brings in more light okay if + + align:start position:0% +small lens brings in more light okay if + + + align:start position:0% +small lens brings in more light okay if +you want to get a camera that can take + + align:start position:0% +you want to get a camera that can take + + + align:start position:0% +you want to get a camera that can take +pictures in very dim light get a camera + + align:start position:0% +pictures in very dim light get a camera + + + align:start position:0% +pictures in very dim light get a camera +with a very large lens opening + + align:start position:0% +with a very large lens opening + + + align:start position:0% +with a very large lens opening +like f1.8 or something like that it'll + + align:start position:0% +like f1.8 or something like that it'll + + + align:start position:0% +like f1.8 or something like that it'll +take in a lot of light okay + + align:start position:0% + + + + align:start position:0% + +question excellent question we we we + + align:start position:0% +question excellent question we we we + + + align:start position:0% +question excellent question we we we +know that animals with forward-looking + + align:start position:0% +know that animals with forward-looking + + + align:start position:0% +know that animals with forward-looking +eyes they're usually + + align:start position:0% +eyes they're usually + + + align:start position:0% +eyes they're usually +predators and primates and primates are + + align:start position:0% +predators and primates and primates are + + + align:start position:0% +predators and primates and primates are +usually Predators too but not all of + + align:start position:0% +usually Predators too but not all of + + + align:start position:0% +usually Predators too but not all of +them some of them have fruit Gathering + + align:start position:0% +them some of them have fruit Gathering + + + align:start position:0% +them some of them have fruit Gathering +primates but they also need good biner + + align:start position:0% +primates but they also need good biner + + + align:start position:0% +primates but they also need good biner +Vision so they have forward- facing eyes + + align:start position:0% +Vision so they have forward- facing eyes + + + align:start position:0% +Vision so they have forward- facing eyes +too uh but what about the animals with + + align:start position:0% +too uh but what about the animals with + + + align:start position:0% +too uh but what about the animals with +these eyes that like the the hamster + + align:start position:0% +these eyes that like the the hamster + + + align:start position:0% +these eyes that like the the hamster +it's got eyes that look 60° out and 30° + + align:start position:0% +it's got eyes that look 60° out and 30° + + + align:start position:0% +it's got eyes that look 60° out and 30° +up Horizon that's way their eyes look + + align:start position:0% +up Horizon that's way their eyes look + + + align:start position:0% +up Horizon that's way their eyes look +that's the natural position of the eyes + + align:start position:0% +that's the natural position of the eyes + + + align:start position:0% +that's the natural position of the eyes +I've measured it in the hamster but it's + + align:start position:0% +I've measured it in the hamster but it's + + + align:start position:0% +I've measured it in the hamster but it's +pretty similar in other little + + align:start position:0% +pretty similar in other little + + + align:start position:0% +pretty similar in other little +rodents they do have an area of + + align:start position:0% +rodents they do have an area of + + + align:start position:0% +rodents they do have an area of +binocular vision there's about at least + + align:start position:0% +binocular vision there's about at least + + + align:start position:0% +binocular vision there's about at least +30° overlap okay and in that Central + + align:start position:0% +30° overlap okay and in that Central + + + align:start position:0% +30° overlap okay and in that Central +area which the center of it is 30° above + + align:start position:0% +area which the center of it is 30° above + + + align:start position:0% +area which the center of it is 30° above +okay they do have binocular vision okay + + align:start position:0% +okay they do have binocular vision okay + + + align:start position:0% +okay they do have binocular vision okay +and they but it's pretty rudimentary + + align:start position:0% +and they but it's pretty rudimentary + + + align:start position:0% +and they but it's pretty rudimentary +compared to the primates and also they + + align:start position:0% +compared to the primates and also they + + + align:start position:0% +compared to the primates and also they +don't have the High Acuity that primates + + align:start position:0% +don't have the High Acuity that primates + + + align:start position:0% +don't have the High Acuity that primates +have but it's still important for them + + align:start position:0% +have but it's still important for them + + + align:start position:0% +have but it's still important for them +but I've looked at hamster Behavior a + + align:start position:0% +but I've looked at hamster Behavior a + + + align:start position:0% +but I've looked at hamster Behavior a +lot and they they + + align:start position:0% +lot and they they + + + align:start position:0% +lot and they they +really + + align:start position:0% +really + + + align:start position:0% +really +things 5T or even 2 fet and 30 ft away + + align:start position:0% +things 5T or even 2 fet and 30 ft away + + + align:start position:0% +things 5T or even 2 fet and 30 ft away +they don't discriminate very well you + + align:start position:0% +they don't discriminate very well you + + + align:start position:0% +they don't discriminate very well you +know but for things near them they + + align:start position:0% +know but for things near them they + + + align:start position:0% +know but for things near them they +definitely can judge Vision they won't + + align:start position:0% +definitely can judge Vision they won't + + + align:start position:0% +definitely can judge Vision they won't +leap sometimes they do but usually they + + align:start position:0% +leap sometimes they do but usually they + + + align:start position:0% +leap sometimes they do but usually they +won't + + align:start position:0% +won't + + + align:start position:0% +won't +jump into places that are too dangerous + + align:start position:0% +jump into places that are too dangerous + + + align:start position:0% +jump into places that are too dangerous +because they're too high they can see + + align:start position:0% +because they're too high they can see + + + align:start position:0% +because they're too high they can see +the depth well enough it doesn't mean + + align:start position:0% +the depth well enough it doesn't mean + + + align:start position:0% +the depth well enough it doesn't mean +stereopsis cues though it could just be + + align:start position:0% +stereopsis cues though it could just be + + + align:start position:0% +stereopsis cues though it could just be +the the uh various other cues like when + + align:start position:0% +the the uh various other cues like when + + + align:start position:0% +the the uh various other cues like when +they move their head The Parallax that + + align:start position:0% +they move their head The Parallax that + + + align:start position:0% +they move their head The Parallax that +you get + + align:start position:0% + + + + align:start position:0% + +uh there's various cues to depth but if + + align:start position:0% +uh there's various cues to depth but if + + + align:start position:0% +uh there's various cues to depth but if +you study sensation perception class + + align:start position:0% +you study sensation perception class + + + align:start position:0% +you study sensation perception class +here at the MIT you'll learn about + + align:start position:0% +here at the MIT you'll learn about + + + align:start position:0% +here at the MIT you'll learn about +multiple different different various + + align:start position:0% +multiple different different various + + + align:start position:0% +multiple different different various +cues for depth okay that don't involve + + align:start position:0% + + + + align:start position:0% + +stereopsis all right so now we want to + + align:start position:0% +stereopsis all right so now we want to + + + align:start position:0% +stereopsis all right so now we want to +look at the retinal + + align:start position:0% +look at the retinal + + + align:start position:0% +look at the retinal +projections it's a pattern you find in + + align:start position:0% +projections it's a pattern you find in + + + align:start position:0% +projections it's a pattern you find in +all the mammals and I should add that + + align:start position:0% +all the mammals and I should add that + + + align:start position:0% +all the mammals and I should add that +it's really similar in all of the + + align:start position:0% +it's really similar in all of the + + + align:start position:0% +it's really similar in all of the +vertebrates okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this is the picture I showed in the last + + align:start position:0% +this is the picture I showed in the last + + + align:start position:0% +this is the picture I showed in the last +class the sort of a cartoon of the optic + + align:start position:0% +class the sort of a cartoon of the optic + + + align:start position:0% +class the sort of a cartoon of the optic +the main optic tract and the accessory + + align:start position:0% +the main optic tract and the accessory + + + align:start position:0% +the main optic tract and the accessory +optic tract here just showing so now we + + align:start position:0% +optic tract here just showing so now we + + + align:start position:0% +optic tract here just showing so now we +want to look at a little more detail of + + align:start position:0% +want to look at a little more detail of + + + align:start position:0% +want to look at a little more detail of +the layout of that system from + + align:start position:0% +the layout of that system from + + + align:start position:0% +the layout of that system from +supermatic nucleus to the two geniculate + + align:start position:0% +supermatic nucleus to the two geniculate + + + align:start position:0% +supermatic nucleus to the two geniculate +nuclei pretectal region where there's + + align:start position:0% +nuclei pretectal region where there's + + + align:start position:0% +nuclei pretectal region where there's +several nuclei where they terminate + + align:start position:0% +several nuclei where they terminate + + + align:start position:0% +several nuclei where they terminate +Superior + + align:start position:0% + + + + align:start position:0% + +cicular so we look at the retinal + + align:start position:0% +cicular so we look at the retinal + + + align:start position:0% +cicular so we look at the retinal +projection in vertebrates the layout of + + align:start position:0% +projection in vertebrates the layout of + + + align:start position:0% +projection in vertebrates the layout of +the optic track and we'll look at them + + align:start position:0% +the optic track and we'll look at them + + + align:start position:0% +the optic track and we'll look at them +in several different ways of looking at + + align:start position:0% +in several different ways of looking at + + + align:start position:0% +in several different ways of looking at +it we'll talk about species differences + + align:start position:0% +it we'll talk about species differences + + + align:start position:0% +it we'll talk about species differences +in relative size of structures because + + align:start position:0% +in relative size of structures because + + + align:start position:0% +in relative size of structures because +qu qualitatively they all have the same + + align:start position:0% +qu qualitatively they all have the same + + + align:start position:0% +qu qualitatively they all have the same +basic + + align:start position:0% +basic + + + align:start position:0% +basic +layout but there are large species + + align:start position:0% +layout but there are large species + + + align:start position:0% +layout but there are large species +differences in relative sizes as well as + + align:start position:0% +differences in relative sizes as well as + + + align:start position:0% +differences in relative sizes as well as +in the eyes are different too so you + + align:start position:0% +in the eyes are different too so you + + + align:start position:0% +in the eyes are different too so you +have different different amount + + align:start position:0% +have different different amount + + + align:start position:0% +have different different amount +different levels of accuity Invision are + + align:start position:0% +different levels of accuity Invision are + + + align:start position:0% +different levels of accuity Invision are +possible in these different species + + align:start position:0% +possible in these different species + + + align:start position:0% +possible in these different species +we'll look a little bit at the at + + align:start position:0% +we'll look a little bit at the at + + + align:start position:0% +we'll look a little bit at the at +architectural differences especially in + + align:start position:0% +architectural differences especially in + + + align:start position:0% +architectural differences especially in +the genicular body and in the optic + + align:start position:0% +the genicular body and in the optic + + + align:start position:0% +the genicular body and in the optic +tectum + + align:start position:0% +tectum + + + align:start position:0% +tectum +so we'll look at lamination in the + + align:start position:0% +so we'll look at lamination in the + + + align:start position:0% +so we'll look at lamination in the +midbrain + + align:start position:0% +midbrain + + + align:start position:0% +midbrain +tectum we'll also look at lamination in + + align:start position:0% +tectum we'll also look at lamination in + + + align:start position:0% +tectum we'll also look at lamination in +the geniculate + + align:start position:0% + + + + align:start position:0% + +body and finally we'll look at + + align:start position:0% +body and finally we'll look at + + + align:start position:0% +body and finally we'll look at +topography and I know when you first get + + align:start position:0% +topography and I know when you first get + + + align:start position:0% +topography and I know when you first get +all this you get a little overwhelmed by + + align:start position:0% +all this you get a little overwhelmed by + + + align:start position:0% +all this you get a little overwhelmed by +all the structures and everything so I'm + + align:start position:0% +all the structures and everything so I'm + + + align:start position:0% +all the structures and everything so I'm +not asking you to memorize the + + align:start position:0% +not asking you to memorize the + + + align:start position:0% +not asking you to memorize the +topography but I want you to see I will + + align:start position:0% +topography but I want you to see I will + + + align:start position:0% +topography but I want you to see I will +present it to you in a way that does + + align:start position:0% +present it to you in a way that does + + + align:start position:0% +present it to you in a way that does +make it pretty easy to learn + + align:start position:0% + + + + align:start position:0% + +okay and these are the questions I put + + align:start position:0% +okay and these are the questions I put + + + align:start position:0% +okay and these are the questions I put +in the list of questions I put online + + align:start position:0% +in the list of questions I put online + + + align:start position:0% +in the list of questions I put online +for + + align:start position:0% + + + + align:start position:0% + +you these are things we've dealt with + + align:start position:0% +you these are things we've dealt with + + + align:start position:0% +you these are things we've dealt with +before these two questions let's just + + align:start position:0% +before these two questions let's just + + + align:start position:0% +before these two questions let's just +see if any of you have an idea about + + align:start position:0% +see if any of you have an idea about + + + align:start position:0% +see if any of you have an idea about +this first of all what's the first + + align:start position:0% +this first of all what's the first + + + align:start position:0% +this first of all what's the first +structure reached by the accents from + + align:start position:0% +structure reached by the accents from + + + align:start position:0% +structure reached by the accents from +the retinal gang + + align:start position:0% +the retinal gang + + + align:start position:0% +the retinal gang +cells Gan cells project through the + + align:start position:0% +cells Gan cells project through the + + + align:start position:0% +cells Gan cells project through the +nerve we start calling at the tract when + + align:start position:0% +nerve we start calling at the tract when + + + align:start position:0% +nerve we start calling at the tract when +it joins with the rest of the dianon so + + align:start position:0% +it joins with the rest of the dianon so + + + align:start position:0% +it joins with the rest of the dianon so +what's the first + + align:start position:0% + + + + align:start position:0% + +structure exactly supermatic nucleus + + align:start position:0% +structure exactly supermatic nucleus + + + align:start position:0% +structure exactly supermatic nucleus +right above the crossing of the accent + + align:start position:0% +right above the crossing of the accent + + + align:start position:0% +right above the crossing of the accent +so it's got to be the first + + align:start position:0% + + + + align:start position:0% + +one it's part of the hypothalamus + + align:start position:0% +one it's part of the hypothalamus + + + align:start position:0% +one it's part of the hypothalamus +definitely + + align:start position:0% +definitely + + + align:start position:0% +definitely +okay the area in front of that region we + + align:start position:0% +okay the area in front of that region we + + + align:start position:0% +okay the area in front of that region we +call preoptic area of the + + align:start position:0% +call preoptic area of the + + + align:start position:0% +call preoptic area of the +hypothalamus because it's in front of + + align:start position:0% +hypothalamus because it's in front of + + + align:start position:0% +hypothalamus because it's in front of +the + + align:start position:0% + + + + align:start position:0% + +opticis actually we talk about the + + align:start position:0% +opticis actually we talk about the + + + align:start position:0% +opticis actually we talk about the +anterior hypothalamic nucleus and then + + align:start position:0% +anterior hypothalamic nucleus and then + + + align:start position:0% +anterior hypothalamic nucleus and then +the preoptic nucleus so I modify my + + align:start position:0% +the preoptic nucleus so I modify my + + + align:start position:0% +the preoptic nucleus so I modify my +first statement a little + + align:start position:0% + + + + align:start position:0% + +bit so the four brain subdivision you've + + align:start position:0% +bit so the four brain subdivision you've + + + align:start position:0% +bit so the four brain subdivision you've +just named it's the + + align:start position:0% +just named it's the + + + align:start position:0% +just named it's the +hypothalamus and the major terminal + + align:start position:0% +hypothalamus and the major terminal + + + align:start position:0% +hypothalamus and the major terminal +nucleus in that subdivision is the super + + align:start position:0% +nucleus in that subdivision is the super + + + align:start position:0% +nucleus in that subdivision is the super +I nucleus now remember there there's + + align:start position:0% +I nucleus now remember there there's + + + align:start position:0% +I nucleus now remember there there's +some spill over there too uh that I + + align:start position:0% +some spill over there too uh that I + + + align:start position:0% +some spill over there too uh that I +showed you last time it does project bit + + align:start position:0% +showed you last time it does project bit + + + align:start position:0% +showed you last time it does project bit +to immediately adjoining parts of the + + align:start position:0% +to immediately adjoining parts of the + + + align:start position:0% +to immediately adjoining parts of the +hypothalamus but we know most about that + + align:start position:0% +hypothalamus but we know most about that + + + align:start position:0% +hypothalamus but we know most about that +supermatic nucleus it's very little + + align:start position:0% +supermatic nucleus it's very little + + + align:start position:0% +supermatic nucleus it's very little +known about the functions of the sparse + + align:start position:0% +known about the functions of the sparse + + + align:start position:0% +known about the functions of the sparse +projections people tend to think that + + align:start position:0% +projections people tend to think that + + + align:start position:0% +projections people tend to think that +they don't play any major roles it's why + + align:start position:0% +they don't play any major roles it's why + + + align:start position:0% +they don't play any major roles it's why +they're so + + align:start position:0% +they're so + + + align:start position:0% +they're so +sparse uh + + align:start position:0% +sparse uh + + + align:start position:0% +sparse uh +I'm not convinced of + + align:start position:0% +I'm not convinced of + + + align:start position:0% +I'm not convinced of +that uh they could play important roles + + align:start position:0% +that uh they could play important roles + + + align:start position:0% +that uh they could play important roles +you uh + + align:start position:0% +you uh + + + align:start position:0% +you uh +but the one thing that makes me doubt it + + align:start position:0% +but the one thing that makes me doubt it + + + align:start position:0% +but the one thing that makes me doubt it +a little bit is just that there's + + align:start position:0% +a little bit is just that there's + + + align:start position:0% +a little bit is just that there's +variability when I study the retinal + + align:start position:0% +variability when I study the retinal + + + align:start position:0% +variability when I study the retinal +projections in a number of different + + align:start position:0% +projections in a number of different + + + align:start position:0% +projections in a number of different +hamsters I do get differences in these + + align:start position:0% +hamsters I do get differences in these + + + align:start position:0% +hamsters I do get differences in these +very sparse + + align:start position:0% +very sparse + + + align:start position:0% +very sparse +projections some animals I see more some + + align:start position:0% +projections some animals I see more some + + + align:start position:0% +projections some animals I see more some +I see less but they're always there okay + + align:start position:0% + + + + align:start position:0% + +okay the next question is what's the + + align:start position:0% +okay the next question is what's the + + + align:start position:0% +okay the next question is what's the +major difference in the nature of the + + align:start position:0% +major difference in the nature of the + + + align:start position:0% +major difference in the nature of the +projections of the dorsal Thalamus on + + align:start position:0% +projections of the dorsal Thalamus on + + + align:start position:0% +projections of the dorsal Thalamus on +the one hand and the ventral Thalamus or + + align:start position:0% +the one hand and the ventral Thalamus or + + + align:start position:0% +the one hand and the ventral Thalamus or +the epithalamus that is after you go + + align:start position:0% +the epithalamus that is after you go + + + align:start position:0% +the epithalamus that is after you go +past the supermatic inuse the accents go + + align:start position:0% +past the supermatic inuse the accents go + + + align:start position:0% +past the supermatic inuse the accents go +up the side of the dlon and they reach + + align:start position:0% +up the side of the dlon and they reach + + + align:start position:0% +up the side of the dlon and they reach +the sub Talus just above the + + align:start position:0% +the sub Talus just above the + + + align:start position:0% +the sub Talus just above the +hypothalamus then they reach the dorsal + + align:start position:0% +hypothalamus then they reach the dorsal + + + align:start position:0% +hypothalamus then they reach the dorsal +Thalamus then they reach the + + align:start position:0% +Thalamus then they reach the + + + align:start position:0% +Thalamus then they reach the +epithalamus the pretectal nuclei in the + + align:start position:0% +epithalamus the pretectal nuclei in the + + + align:start position:0% +epithalamus the pretectal nuclei in the +epithalamus so there's a big difference + + align:start position:0% +epithalamus so there's a big difference + + + align:start position:0% +epithalamus so there's a big difference +though in the nature of the projections + + align:start position:0% +though in the nature of the projections + + + align:start position:0% +though in the nature of the projections +of the dorsal Thalamus and those other + + align:start position:0% +of the dorsal Thalamus and those other + + + align:start position:0% +of the dorsal Thalamus and those other +groups what is that + + align:start position:0% + + + + align:start position:0% + +difference exactly biggest difference is + + align:start position:0% +difference exactly biggest difference is + + + align:start position:0% +difference exactly biggest difference is +what she just said the dorsal phalance + + align:start position:0% +what she just said the dorsal phalance + + + align:start position:0% +what she just said the dorsal phalance +and all the major cell GR + + align:start position:0% +and all the major cell GR + + + align:start position:0% +and all the major cell GR +the the at least the Neo Thalamus that + + align:start position:0% +the the at least the Neo Thalamus that + + + align:start position:0% +the the at least the Neo Thalamus that +more recent but we think we of the + + align:start position:0% +more recent but we think we of the + + + align:start position:0% +more recent but we think we of the +dorsal Thalamus like the lateral + + align:start position:0% +dorsal Thalamus like the lateral + + + align:start position:0% +dorsal Thalamus like the lateral +genicular body but the same thing holds + + align:start position:0% +genicular body but the same thing holds + + + align:start position:0% +genicular body but the same thing holds +true for the ventral nucleus mediodorsal + + align:start position:0% +true for the ventral nucleus mediodorsal + + + align:start position:0% +true for the ventral nucleus mediodorsal +nucleus uh medial genicular body IT + + align:start position:0% +nucleus uh medial genicular body IT + + + align:start position:0% +nucleus uh medial genicular body IT +projects to Cortex okay mainly to + + align:start position:0% +projects to Cortex okay mainly to + + + align:start position:0% +projects to Cortex okay mainly to +neocortex it goes to the + + align:start position:0% + + + + align:start position:0% + +embran some neurons some accents will + + align:start position:0% +embran some neurons some accents will + + + align:start position:0% +embran some neurons some accents will +have collaterals in the them on their + + align:start position:0% +have collaterals in the them on their + + + align:start position:0% +have collaterals in the them on their +way to the end braan but the major + + align:start position:0% +way to the end braan but the major + + + align:start position:0% +way to the end braan but the major +projections to the end braan those other + + align:start position:0% +projections to the end braan those other + + + align:start position:0% +projections to the end braan those other +structures + + align:start position:0% +structures + + + align:start position:0% +structures +subs and epip Palms don't project to the + + align:start position:0% +subs and epip Palms don't project to the + + + align:start position:0% +subs and epip Palms don't project to the +end + + align:start position:0% +end + + + align:start position:0% +end +braan I mean there were + + align:start position:0% +braan I mean there were + + + align:start position:0% +braan I mean there were +reports you know that they do but modern + + align:start position:0% +reports you know that they do but modern + + + align:start position:0% +reports you know that they do but modern +techniques have never been able to + + align:start position:0% +techniques have never been able to + + + align:start position:0% +techniques have never been able to +verify that they don't project to + + align:start position:0% +verify that they don't project to + + + align:start position:0% +verify that they don't project to +neocortex in + + align:start position:0% +neocortex in + + + align:start position:0% +neocortex in +fact besides some ascending + + align:start position:0% +fact besides some ascending + + + align:start position:0% +fact besides some ascending +projections they have a lot of + + align:start position:0% +projections they have a lot of + + + align:start position:0% +projections they have a lot of +descending + + align:start position:0% + + + + align:start position:0% + +projections okay so that's the major + + align:start position:0% + + + + align:start position:0% + +difference okay now I last time I + + align:start position:0% +difference okay now I last time I + + + align:start position:0% +difference okay now I last time I +mention the + + align:start position:0% +mention the + + + align:start position:0% +mention the +epithalamus as a codl most + + align:start position:0% +epithalamus as a codl most + + + align:start position:0% +epithalamus as a codl most +dianic segment or + + align:start position:0% +dianic segment or + + + align:start position:0% +dianic segment or +neuromere it includes cell groups where + + align:start position:0% +neuromere it includes cell groups where + + + align:start position:0% +neuromere it includes cell groups where +the optic track as dense terminations so + + align:start position:0% +the optic track as dense terminations so + + + align:start position:0% +the optic track as dense terminations so +again what do we call those areas of + + align:start position:0% + + + + align:start position:0% + +termination we call them by we call them + + align:start position:0% +termination we call them by we call them + + + align:start position:0% +termination we call them by we call them +certain nuclei depending on where they + + align:start position:0% +certain nuclei depending on where they + + + align:start position:0% +certain nuclei depending on where they +are they're in + + align:start position:0% +are they're in + + + align:start position:0% +are they're in +front of the tectum so we call them + + align:start position:0% +front of the tectum so we call them + + + align:start position:0% +front of the tectum so we call them +prector okay it doesn't they are rather + + align:start position:0% +prector okay it doesn't they are rather + + + align:start position:0% +prector okay it doesn't they are rather +different these different groups and + + align:start position:0% +different these different groups and + + + align:start position:0% +different these different groups and +they have different functions but we + + align:start position:0% +they have different functions but we + + + align:start position:0% +they have different functions but we +lump them together because they're all + + align:start position:0% +lump them together because they're all + + + align:start position:0% +lump them together because they're all +in that same region call them the + + align:start position:0% +in that same region call them the + + + align:start position:0% +in that same region call them the +pretectal nuclei okay so this is two + + align:start position:0% +pretectal nuclei okay so this is two + + + align:start position:0% +pretectal nuclei okay so this is two +ways to look at don't worry I'll blow + + align:start position:0% +ways to look at don't worry I'll blow + + + align:start position:0% +ways to look at don't worry I'll blow +these up but here's the + + align:start position:0% + + + + align:start position:0% + +crosssection of the level through the + + align:start position:0% +crosssection of the level through the + + + align:start position:0% +crosssection of the level through the +Dippin this is actually behind the optic + + align:start position:0% +Dippin this is actually behind the optic + + + align:start position:0% +Dippin this is actually behind the optic +kais but you see the optic tract + + align:start position:0% +kais but you see the optic tract + + + align:start position:0% +kais but you see the optic tract +covering most of the dianon or tween + + align:start position:0% +covering most of the dianon or tween + + + align:start position:0% +covering most of the dianon or tween +brain at this level the pretectum up + + align:start position:0% +brain at this level the pretectum up + + + align:start position:0% +brain at this level the pretectum up +here dorsal thamus with the lateral + + align:start position:0% +here dorsal thamus with the lateral + + + align:start position:0% +here dorsal thamus with the lateral +geniculate nucleus right there here's + + align:start position:0% +geniculate nucleus right there here's + + + align:start position:0% +geniculate nucleus right there here's +the subthalamus with the ventral nucleus + + align:start position:0% +the subthalamus with the ventral nucleus + + + align:start position:0% +the subthalamus with the ventral nucleus +of the genicular body there there's + + align:start position:0% +of the genicular body there there's + + + align:start position:0% +of the genicular body there there's +hypothalamus okay this is behind the + + align:start position:0% +hypothalamus okay this is behind the + + + align:start position:0% +hypothalamus okay this is behind the +opticis and the optic track C goes + + align:start position:0% +opticis and the optic track C goes + + + align:start position:0% +opticis and the optic track C goes +covers all these that's why that area is + + align:start position:0% +covers all these that's why that area is + + + align:start position:0% +covers all these that's why that area is +sometimes called optic balance just + + align:start position:0% +sometimes called optic balance just + + + align:start position:0% +sometimes called optic balance just +because the aons of the optic track + + align:start position:0% +because the aons of the optic track + + + align:start position:0% +because the aons of the optic track +cover + + align:start position:0% +cover + + + align:start position:0% +cover +it and then these are the subdivisions + + align:start position:0% +it and then these are the subdivisions + + + align:start position:0% +it and then these are the subdivisions +written as the names for + + align:start position:0% +written as the names for + + + align:start position:0% +written as the names for +their the + + align:start position:0% +their the + + + align:start position:0% +their the +neuromeres now we know hypothalamus is + + align:start position:0% +neuromeres now we know hypothalamus is + + + align:start position:0% +neuromeres now we know hypothalamus is +actually two or three different neurom + + align:start position:0% +actually two or three different neurom + + + align:start position:0% +actually two or three different neurom +mirors and then we call this the ventral + + align:start position:0% +mirors and then we call this the ventral + + + align:start position:0% +mirors and then we call this the ventral +Talus then in the adult we call it sub + + align:start position:0% +Talus then in the adult we call it sub + + + align:start position:0% +Talus then in the adult we call it sub +Talus then the dorsal pelis then the + + align:start position:0% +Talus then the dorsal pelis then the + + + align:start position:0% +Talus then the dorsal pelis then the +epis okay but now there's another way to + + align:start position:0% +epis okay but now there's another way to + + + align:start position:0% +epis okay but now there's another way to +look at the track that I use for + + align:start position:0% +look at the track that I use for + + + align:start position:0% +look at the track that I use for +teaching purposes but I think it's very + + align:start position:0% +teaching purposes but I think it's very + + + align:start position:0% +teaching purposes but I think it's very +useful I just take the track all the way + + align:start position:0% +useful I just take the track all the way + + + align:start position:0% +useful I just take the track all the way +from the supermatic nucleus all the way + + align:start position:0% +from the supermatic nucleus all the way + + + align:start position:0% +from the supermatic nucleus all the way +to the tectum just stretch it out okay + + align:start position:0% +to the tectum just stretch it out okay + + + align:start position:0% +to the tectum just stretch it out okay +so you + + align:start position:0% +so you + + + align:start position:0% +so you +see the retina would be way off here to + + align:start position:0% +see the retina would be way off here to + + + align:start position:0% +see the retina would be way off here to +the left off the screen there to the + + align:start position:0% +the left off the screen there to the + + + align:start position:0% +the left off the screen there to the +left there's the super chiasmatic + + align:start position:0% +left there's the super chiasmatic + + + align:start position:0% +left there's the super chiasmatic +nucleus it's more commonly abbreviated + + align:start position:0% +nucleus it's more commonly abbreviated + + + align:start position:0% +nucleus it's more commonly abbreviated +scn here we call it just but could be + + align:start position:0% +scn here we call it just but could be + + + align:start position:0% +scn here we call it just but could be +done either way and then I just follow + + align:start position:0% +done either way and then I just follow + + + align:start position:0% +done either way and then I just follow +the accents straighten out the tract + + align:start position:0% +the accents straighten out the tract + + + align:start position:0% +the accents straighten out the tract +okay and I show what happens to them the + + align:start position:0% +okay and I show what happens to them the + + + align:start position:0% +okay and I show what happens to them the +longest ones make it to the superior + + align:start position:0% + + + + align:start position:0% + +cicular where they no longer travel + + align:start position:0% +cicular where they no longer travel + + + align:start position:0% +cicular where they no longer travel +mainly at the surface the rest of the + + align:start position:0% +mainly at the surface the rest of the + + + align:start position:0% +mainly at the surface the rest of the +tract is mainly at the surface there are + + align:start position:0% +tract is mainly at the surface there are + + + align:start position:0% +tract is mainly at the surface there are +some that travel internally we call that + + align:start position:0% +some that travel internally we call that + + + align:start position:0% +some that travel internally we call that +the internal optic track but there's + + align:start position:0% +the internal optic track but there's + + + align:start position:0% +the internal optic track but there's +smaller numbers of accents that do that + + align:start position:0% +smaller numbers of accents that do that + + + align:start position:0% +smaller numbers of accents that do that +the main ones travel to the surface + + align:start position:0% +the main ones travel to the surface + + + align:start position:0% +the main ones travel to the surface +except when they get the sphere + + align:start position:0% +except when they get the sphere + + + align:start position:0% +except when they get the sphere +calculus actually they do travel at the + + align:start position:0% +calculus actually they do travel at the + + + align:start position:0% +calculus actually they do travel at the +surface of the culus early in + + align:start position:0% +surface of the culus early in + + + align:start position:0% +surface of the culus early in +development when they first get + + align:start position:0% +development when they first get + + + align:start position:0% +development when they first get +there so then how do they end + + align:start position:0% +there so then how do they end + + + align:start position:0% +there so then how do they end +up + + align:start position:0% +up + + + align:start position:0% +up +down below those superficial layers what + + align:start position:0% +down below those superficial layers what + + + align:start position:0% +down below those superficial layers what +has to happen they're on the + + align:start position:0% +has to happen they're on the + + + align:start position:0% +has to happen they're on the +surface and then they're not with + + align:start position:0% +surface and then they're not with + + + align:start position:0% +surface and then they're not with +further development either the axons + + align:start position:0% +further development either the axons + + + align:start position:0% +further development either the axons +that were on the surface have to die off + + align:start position:0% +that were on the surface have to die off + + + align:start position:0% +that were on the surface have to die off +or the cells in the calculus migrate up + + align:start position:0% +or the cells in the calculus migrate up + + + align:start position:0% +or the cells in the calculus migrate up +through them they're still migrating + + align:start position:0% +through them they're still migrating + + + align:start position:0% +through them they're still migrating +when this tract is farming and the + + align:start position:0% +when this tract is farming and the + + + align:start position:0% +when this tract is farming and the +latter interpretation appears to be + + align:start position:0% +latter interpretation appears to be + + + align:start position:0% +latter interpretation appears to be +true because you do see cell migrations + + align:start position:0% +true because you do see cell migrations + + + align:start position:0% +true because you do see cell migrations +going up to the superficial gray + + align:start position:0% +going up to the superficial gray + + + align:start position:0% +going up to the superficial gray +occurring after the first accents have + + align:start position:0% +occurring after the first accents have + + + align:start position:0% +occurring after the first accents have +reached there and when you look with + + align:start position:0% +reached there and when you look with + + + align:start position:0% +reached there and when you look with +stains that are capable of seeing + + align:start position:0% +stains that are capable of seeing + + + align:start position:0% +stains that are capable of seeing +degeneration occurring you don't see a + + align:start position:0% +degeneration occurring you don't see a + + + align:start position:0% +degeneration occurring you don't see a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +degeneration okay so we think it's it's + + align:start position:0% +degeneration okay so we think it's it's + + + align:start position:0% +degeneration okay so we think it's it's +actually doe with the cell migration + + align:start position:0% +actually doe with the cell migration + + + align:start position:0% +actually doe with the cell migration +okay now here you see them it looks like + + align:start position:0% +okay now here you see them it looks like + + + align:start position:0% +okay now here you see them it looks like +they're branching off let let's do it + + align:start position:0% +they're branching off let let's do it + + + align:start position:0% +they're branching off let let's do it +this way here's that first picture again + + align:start position:0% +this way here's that first picture again + + + align:start position:0% +this way here's that first picture again +where I blow it up but it's the same + + align:start position:0% +where I blow it up but it's the same + + + align:start position:0% +where I blow it up but it's the same +thing and I point out here ventral + + align:start position:0% +thing and I point out here ventral + + + align:start position:0% +thing and I point out here ventral +Thalamus is not the ventral nucleus of + + align:start position:0% +Thalamus is not the ventral nucleus of + + + align:start position:0% +Thalamus is not the ventral nucleus of +the dorsal pamus it's really subthalamus + + align:start position:0% +the dorsal pamus it's really subthalamus + + + align:start position:0% +the dorsal pamus it's really subthalamus +okay the vental nucleus is this nucleus + + align:start position:0% +okay the vental nucleus is this nucleus + + + align:start position:0% +okay the vental nucleus is this nucleus +right up in here part of the dorsal + + align:start position:0% +right up in here part of the dorsal + + + align:start position:0% +right up in here part of the dorsal +pal so here I just show the places the + + align:start position:0% +pal so here I just show the places the + + + align:start position:0% +pal so here I just show the places the +optic crack terminates you see the + + align:start position:0% +optic crack terminates you see the + + + align:start position:0% +optic crack terminates you see the +dorsal part of the lateral genicular + + align:start position:0% +dorsal part of the lateral genicular + + + align:start position:0% +dorsal part of the lateral genicular +body now remember this is a road + + align:start position:0% +body now remember this is a road + + + align:start position:0% +body now remember this is a road +the + + align:start position:0% + + + + align:start position:0% + +lp is not huge but it's the rest of the + + align:start position:0% +lp is not huge but it's the rest of the + + + align:start position:0% +lp is not huge but it's the rest of the +lateral phalam besides the genicular + + align:start position:0% +lateral phalam besides the genicular + + + align:start position:0% +lateral phalam besides the genicular +bodies you have lateral thalamic nuclei + + align:start position:0% +bodies you have lateral thalamic nuclei + + + align:start position:0% +bodies you have lateral thalamic nuclei +the the medial geniculate is another + + align:start position:0% +the the medial geniculate is another + + + align:start position:0% +the the medial geniculate is another +lateral thalamic + + align:start position:0% +lateral thalamic + + + align:start position:0% +lateral thalamic +nucleus + + align:start position:0% +nucleus + + + align:start position:0% +nucleus +uh here is a + + align:start position:0% +uh here is a + + + align:start position:0% +uh here is a +human 12 weeks post conception okay + + align:start position:0% +human 12 weeks post conception okay + + + align:start position:0% +human 12 weeks post conception okay +okay so 3mon human + + align:start position:0% +okay so 3mon human + + + align:start position:0% +okay so 3mon human +fetus there's the rodent + + align:start position:0% +fetus there's the rodent + + + align:start position:0% +fetus there's the rodent +adult here's the human + + align:start position:0% +adult here's the human + + + align:start position:0% +adult here's the human +Fus the + + align:start position:0% +Fus the + + + align:start position:0% +Fus the +adult human FS doesn't look like this at + + align:start position:0% +adult human FS doesn't look like this at + + + align:start position:0% +adult human FS doesn't look like this at +all okay I just want to point out that + + align:start position:0% +all okay I just want to point out that + + + align:start position:0% +all okay I just want to point out that +it's really the same as the + + align:start position:0% +it's really the same as the + + + align:start position:0% +it's really the same as the +rod in fact the embryo looks very + + align:start position:0% +rod in fact the embryo looks very + + + align:start position:0% +rod in fact the embryo looks very +similar okay but then it changes why + + align:start position:0% +similar okay but then it changes why + + + align:start position:0% +similar okay but then it changes why +anybody figure that + + align:start position:0% +anybody figure that + + + align:start position:0% +anybody figure that +out what happens to the human fals + + align:start position:0% +out what happens to the human fals + + + align:start position:0% +out what happens to the human fals +development after that first 3 months of + + align:start position:0% +development after that first 3 months of + + + align:start position:0% +development after that first 3 months of +Life the brain of a 3 month human fetus + + align:start position:0% +Life the brain of a 3 month human fetus + + + align:start position:0% +Life the brain of a 3 month human fetus +is pretty + + align:start position:0% +is pretty + + + align:start position:0% +is pretty +similar to a hamster just after + + align:start position:0% + + + + align:start position:0% + +birth but then something continues + + align:start position:0% +birth but then something continues + + + align:start position:0% +birth but then something continues +developing in the hamster in both the + + align:start position:0% +developing in the hamster in both the + + + align:start position:0% +developing in the hamster in both the +hamster and human but mostly in human + + align:start position:0% +hamster and human but mostly in human + + + align:start position:0% +hamster and human but mostly in human +after that first three + + align:start position:0% + + + + align:start position:0% + +months that means by the way the hamster + + align:start position:0% +months that means by the way the hamster + + + align:start position:0% +months that means by the way the hamster +at the human at 3 months postconception + + align:start position:0% +at the human at 3 months postconception + + + align:start position:0% +at the human at 3 months postconception +is like an early postnatal hamster and + + align:start position:0% +is like an early postnatal hamster and + + + align:start position:0% +is like an early postnatal hamster and +the hamster is born in the 16th day of + + align:start position:0% +the hamster is born in the 16th day of + + + align:start position:0% +the hamster is born in the 16th day of +gestation just to give you some times + + align:start position:0% +gestation just to give you some times + + + align:start position:0% +gestation just to give you some times +but anyway what + + align:start position:0% +but anyway what + + + align:start position:0% +but anyway what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +this nucleus n labeled NL here the + + align:start position:0% +this nucleus n labeled NL here the + + + align:start position:0% +this nucleus n labeled NL here the +lateral nucleus nucleus lateralis this + + align:start position:0% +lateral nucleus nucleus lateralis this + + + align:start position:0% +lateral nucleus nucleus lateralis this +is the posterior part of nucleus + + align:start position:0% +is the posterior part of nucleus + + + align:start position:0% +is the posterior part of nucleus +lateralis okay that grows and grows and + + align:start position:0% +lateralis okay that grows and grows and + + + align:start position:0% +lateralis okay that grows and grows and +grows and in primates it really gets + + align:start position:0% +grows and in primates it really gets + + + align:start position:0% +grows and in primates it really gets +huge and we change its name we call only + + align:start position:0% +huge and we change its name we call only + + + align:start position:0% +huge and we change its name we call only +part of it the lateral posterior nucleus + + align:start position:0% +part of it the lateral posterior nucleus + + + align:start position:0% +part of it the lateral posterior nucleus +like we call the whole thing in rodents + + align:start position:0% +like we call the whole thing in rodents + + + align:start position:0% +like we call the whole thing in rodents +the rest of it we call the + + align:start position:0% +the rest of it we call the + + + align:start position:0% +the rest of it we call the +pulvinar which means pillow + + align:start position:0% +pulvinar which means pillow + + + align:start position:0% +pulvinar which means pillow +the pillow because it's bulging out so + + align:start position:0% +the pillow because it's bulging out so + + + align:start position:0% +the pillow because it's bulging out so +much because the cortex IT projects + + align:start position:0% +much because the cortex IT projects + + + align:start position:0% +much because the cortex IT projects +to even though it's there real early it + + align:start position:0% +to even though it's there real early it + + + align:start position:0% +to even though it's there real early it +expands so + + align:start position:0% +expands so + + + align:start position:0% +expands so +much and + + align:start position:0% +much and + + + align:start position:0% +much and +Thalamus you know a lot of people that + + align:start position:0% +Thalamus you know a lot of people that + + + align:start position:0% +Thalamus you know a lot of people that +talk about cortex just think the sensory + + align:start position:0% +talk about cortex just think the sensory + + + align:start position:0% +talk about cortex just think the sensory +input comes to it then you go from one + + align:start position:0% +input comes to it then you go from one + + + align:start position:0% +input comes to it then you go from one +region to the other in the cortex then + + align:start position:0% +region to the other in the cortex then + + + align:start position:0% +region to the other in the cortex then +you go out through the motor cortex not + + align:start position:0% +you go out through the motor cortex not + + + align:start position:0% +you go out through the motor cortex not +a very good accurate picture even though + + align:start position:0% +a very good accurate picture even though + + + align:start position:0% +a very good accurate picture even though +the majority of people in this building + + align:start position:0% +the majority of people in this building + + + align:start position:0% +the majority of people in this building +think like that that's not really a good + + align:start position:0% +think like that that's not really a good + + + align:start position:0% +think like that that's not really a good +picture connections of the cortex so + + align:start position:0% +picture connections of the cortex so + + + align:start position:0% +picture connections of the cortex so +we'll be dealing with that including + + align:start position:0% +we'll be dealing with that including + + + align:start position:0% +we'll be dealing with that including +some next next class but we'll continue + + align:start position:0% +some next next class but we'll continue + + + align:start position:0% +some next next class but we'll continue +dealing with it for the other + + align:start position:0% +dealing with it for the other + + + align:start position:0% +dealing with it for the other +systems all right so that's what happens + + align:start position:0% +systems all right so that's what happens + + + align:start position:0% +systems all right so that's what happens +otherwise this this at this + + align:start position:0% +otherwise this this at this + + + align:start position:0% +otherwise this this at this +stage these pictures are pretty similar + + align:start position:0% +stage these pictures are pretty similar + + + align:start position:0% +stage these pictures are pretty similar +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +remember those + + align:start position:0% +remember those + + + align:start position:0% +remember those +divisions + + align:start position:0% +divisions + + + align:start position:0% +divisions +here happen because here an even earli + + align:start position:0% +here happen because here an even earli + + + align:start position:0% +here happen because here an even earli +very early embryon embryo where I show a + + align:start position:0% +very early embryon embryo where I show a + + + align:start position:0% +very early embryon embryo where I show a +side view with the segments remember the + + align:start position:0% +side view with the segments remember the + + + align:start position:0% +side view with the segments remember the +seven ROM mirors here then a little + + align:start position:0% +seven ROM mirors here then a little + + + align:start position:0% +seven ROM mirors here then a little +segment we call the ismos and then the + + align:start position:0% +segment we call the ismos and then the + + + align:start position:0% +segment we call the ismos and then the +midbrain which is a pretty big segment + + align:start position:0% +midbrain which is a pretty big segment + + + align:start position:0% +midbrain which is a pretty big segment +and then the + + align:start position:0% +and then the + + + align:start position:0% +and then the +epipal with the pretectal farming area + + align:start position:0% +epipal with the pretectal farming area + + + align:start position:0% +epipal with the pretectal farming area +farming here the vanela farming here and + + align:start position:0% +farming here the vanela farming here and + + + align:start position:0% +farming here the vanela farming here and +then dorsal thalamus + + align:start position:0% +then dorsal thalamus + + + align:start position:0% +then dorsal thalamus +ventral Thalamus or + + align:start position:0% +ventral Thalamus or + + + align:start position:0% +ventral Thalamus or +subthalamus + + align:start position:0% + + + + align:start position:0% + +hypothalamus which is actually turns out + + align:start position:0% +hypothalamus which is actually turns out + + + align:start position:0% +hypothalamus which is actually turns out +to be several + + align:start position:0% +to be several + + + align:start position:0% +to be several +subdivisions + + align:start position:0% + + + + align:start position:0% + +okay so then these are the questions we + + align:start position:0% +okay so then these are the questions we + + + align:start position:0% +okay so then these are the questions we +want to answer now I want you to be able + + align:start position:0% +want to answer now I want you to be able + + + align:start position:0% +want to answer now I want you to be able +to name the five main optic track + + align:start position:0% +to name the five main optic track + + + align:start position:0% +to name the five main optic track +termination areas in the order they're + + align:start position:0% +termination areas in the order they're + + + align:start position:0% +termination areas in the order they're +reached by the optic + + align:start position:0% + + + + align:start position:0% + +track so here they are they're already + + align:start position:0% +track so here they are they're already + + + align:start position:0% +track so here they are they're already +pass the + + align:start position:0% +pass the + + + align:start position:0% +pass the +supermatic then you have the two + + align:start position:0% +supermatic then you have the two + + + align:start position:0% +supermatic then you have the two +geniculate bodies then they get to the + + align:start position:0% +geniculate bodies then they get to the + + + align:start position:0% +geniculate bodies then they get to the +pretectal area here I show them on this + + align:start position:0% +pretectal area here I show them on this + + + align:start position:0% +pretectal area here I show them on this +picture and then finally they they turn + + align:start position:0% +picture and then finally they they turn + + + align:start position:0% +picture and then finally they they turn +codly and they get to the spir click so + + align:start position:0% +codly and they get to the spir click so + + + align:start position:0% +codly and they get to the spir click so +those are the areas one supermatic two + + align:start position:0% +those are the areas one supermatic two + + + align:start position:0% +those are the areas one supermatic two +three four and then five Superior + + align:start position:0% + + + + align:start position:0% + +clickers and then I ask what addition + + align:start position:0% +clickers and then I ask what addition + + + align:start position:0% +clickers and then I ask what addition +areas receive sparse retinal projections + + align:start position:0% +areas receive sparse retinal projections + + + align:start position:0% +areas receive sparse retinal projections +well I already talked about some near + + align:start position:0% +well I already talked about some near + + + align:start position:0% +well I already talked about some near +the supermatic nucleus but there's some + + align:start position:0% +the supermatic nucleus but there's some + + + align:start position:0% +the supermatic nucleus but there's some +other sparse projections in the + + align:start position:0% +other sparse projections in the + + + align:start position:0% +other sparse projections in the +phalance that are somewhat variable from + + align:start position:0% +phalance that are somewhat variable from + + + align:start position:0% +phalance that are somewhat variable from +animal to animal at least among the + + align:start position:0% +animal to animal at least among the + + + align:start position:0% +animal to animal at least among the +hamsters that I've studied I suspect + + align:start position:0% +hamsters that I've studied I suspect + + + align:start position:0% +hamsters that I've studied I suspect +it's true of other species too and that + + align:start position:0% +it's true of other species too and that + + + align:start position:0% +it's true of other species too and that +would + + align:start position:0% +would + + + align:start position:0% +would +be projections to the lp nucleus here + + align:start position:0% +be projections to the lp nucleus here + + + align:start position:0% +be projections to the lp nucleus here +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so and there are other little + + align:start position:0% +so and there are other little + + + align:start position:0% +so and there are other little +projections near the main projections + + align:start position:0% +projections near the main projections + + + align:start position:0% +projections near the main projections +that are also a little bit variable and + + align:start position:0% +that are also a little bit variable and + + + align:start position:0% +that are also a little bit variable and +then I say inputs from the right and + + align:start position:0% +then I say inputs from the right and + + + align:start position:0% +then I say inputs from the right and +left eyes terminate in different + + align:start position:0% +left eyes terminate in different + + + align:start position:0% +left eyes terminate in different +areas a separation that's especially + + align:start position:0% +areas a separation that's especially + + + align:start position:0% +areas a separation that's especially +important for creating binocular + + align:start position:0% +important for creating binocular + + + align:start position:0% +important for creating binocular +disparity cues for depth for perceiving + + align:start position:0% +disparity cues for depth for perceiving + + + align:start position:0% +disparity cues for depth for perceiving +depth visually visual object so describe + + align:start position:0% +depth visually visual object so describe + + + align:start position:0% +depth visually visual object so describe +the appearance of the distinct areas in + + align:start position:0% +the appearance of the distinct areas in + + + align:start position:0% +the appearance of the distinct areas in +the dianon of a small rodent and of a + + align:start position:0% +the dianon of a small rodent and of a + + + align:start position:0% +the dianon of a small rodent and of a +monkey so here we're talking about the + + align:start position:0% +monkey so here we're talking about the + + + align:start position:0% +monkey so here we're talking about the +layers in the genicular body so in this + + align:start position:0% +layers in the genicular body so in this + + + align:start position:0% +layers in the genicular body so in this +picture that stretched out optic tract I + + align:start position:0% +picture that stretched out optic tract I + + + align:start position:0% +picture that stretched out optic tract I +show + + align:start position:0% +show + + + align:start position:0% +show +that so there's the supermatic then they + + align:start position:0% +that so there's the supermatic then they + + + align:start position:0% +that so there's the supermatic then they +reach the sub pamus this is the lateral + + align:start position:0% +reach the sub pamus this is the lateral + + + align:start position:0% +reach the sub pamus this is the lateral +genicular body ventral + + align:start position:0% +genicular body ventral + + + align:start position:0% +genicular body ventral +portion often abbreviated just LG + + align:start position:0% +portion often abbreviated just LG + + + align:start position:0% +portion often abbreviated just LG +V and it's also abbreviated lgn B + + align:start position:0% +V and it's also abbreviated lgn B + + + align:start position:0% +V and it's also abbreviated lgn B +lateral genicular nucleus vental + + align:start position:0% +lateral genicular nucleus vental + + + align:start position:0% +lateral genicular nucleus vental +part but notice here these are accents + + align:start position:0% +part but notice here these are accents + + + align:start position:0% +part but notice here these are accents +from the controlateral eye that I'm + + align:start position:0% +from the controlateral eye that I'm + + + align:start position:0% +from the controlateral eye that I'm +drawing I show a little area separated + + align:start position:0% +drawing I show a little area separated + + + align:start position:0% +drawing I show a little area separated +here by the dash lines in both the + + align:start position:0% +here by the dash lines in both the + + + align:start position:0% +here by the dash lines in both the +vental and dorsal genicular bodies where + + align:start position:0% +vental and dorsal genicular bodies where + + + align:start position:0% +vental and dorsal genicular bodies where +those accents don't + + align:start position:0% +those accents don't + + + align:start position:0% +those accents don't +go they don't go there because they're + + align:start position:0% +go they don't go there because they're + + + align:start position:0% +go they don't go there because they're +getting input from the outer eye okay + + align:start position:0% +getting input from the outer eye okay + + + align:start position:0% +getting input from the outer eye okay +it's a laminated structure not so + + align:start position:0% +it's a laminated structure not so + + + align:start position:0% +it's a laminated structure not so +obvious in the rodent but when you go to + + align:start position:0% +obvious in the rodent but when you go to + + + align:start position:0% +obvious in the rodent but when you go to +other animals like here's a four layer + + align:start position:0% +other animals like here's a four layer + + + align:start position:0% +other animals like here's a four layer +geniculate body which you find in some + + align:start position:0% +geniculate body which you find in some + + + align:start position:0% +geniculate body which you find in some +species then you find that the + + align:start position:0% +species then you find that the + + + align:start position:0% +species then you find that the +controlateral eye is projecting to the + + align:start position:0% +controlateral eye is projecting to the + + + align:start position:0% +controlateral eye is projecting to the +outermost the layer nearest the optic + + align:start position:0% +outermost the layer nearest the optic + + + align:start position:0% +outermost the layer nearest the optic +tract then it skips a layer and then it + + align:start position:0% +tract then it skips a layer and then it + + + align:start position:0% +tract then it skips a layer and then it +projects to the next layer and then not + + align:start position:0% +projects to the next layer and then not + + + align:start position:0% +projects to the next layer and then not +to the last l so it projects to one and + + align:start position:0% +to the last l so it projects to one and + + + align:start position:0% +to the last l so it projects to one and +three not to two and + + align:start position:0% +three not to two and + + + align:start position:0% +three not to two and +four and then in primates like the + + align:start position:0% +four and then in primates like the + + + align:start position:0% +four and then in primates like the +monkeys not all primates but at least + + align:start position:0% +monkeys not all primates but at least + + + align:start position:0% +monkeys not all primates but at least +monkeys + + align:start position:0% +monkeys + + + align:start position:0% +monkeys +and the Apes and humans you have six + + align:start position:0% +and the Apes and humans you have six + + + align:start position:0% +and the Apes and humans you have six +layers sometimes you see seven in some + + align:start position:0% +layers sometimes you see seven in some + + + align:start position:0% +layers sometimes you see seven in some +parts of the genic body usually we + + align:start position:0% +parts of the genic body usually we + + + align:start position:0% +parts of the genic body usually we +number six number them as six so we'll + + align:start position:0% +number six number them as six so we'll + + + align:start position:0% +number six number them as six so we'll +see that then the axons go through and + + align:start position:0% +see that then the axons go through and + + + align:start position:0% +see that then the axons go through and +over the lp lateral posterior nucleus + + align:start position:0% +over the lp lateral posterior nucleus + + + align:start position:0% +over the lp lateral posterior nucleus +that is the rest of the lateral Palance + + align:start position:0% +that is the rest of the lateral Palance + + + align:start position:0% +that is the rest of the lateral Palance +that part that grows so big in humans + + align:start position:0% +that part that grows so big in humans + + + align:start position:0% +that part that grows so big in humans +and I show a few terminations there it's + + align:start position:0% +and I show a few terminations there it's + + + align:start position:0% +and I show a few terminations there it's +somewhat + + align:start position:0% +somewhat + + + align:start position:0% +somewhat +variable but they are there they're + + align:start position:0% +variable but they are there they're + + + align:start position:0% +variable but they are there they're +sparse + + align:start position:0% +sparse + + + align:start position:0% +sparse +determinations + + align:start position:0% +determinations + + + align:start position:0% +determinations +okay again we don't + + align:start position:0% +okay again we don't + + + align:start position:0% +okay again we don't +know what those + + align:start position:0% +know what those + + + align:start position:0% +know what those +do maybe we don't need to know because + + align:start position:0% +do maybe we don't need to know because + + + align:start position:0% +do maybe we don't need to know because +those same + + align:start position:0% +those same + + + align:start position:0% +those same +neurons where those sparse projections + + align:start position:0% +neurons where those sparse projections + + + align:start position:0% +neurons where those sparse projections +occur get very heavy visual + + align:start position:0% +occur get very heavy visual + + + align:start position:0% +occur get very heavy visual +input but coming from the + + align:start position:0% +input but coming from the + + + align:start position:0% +input but coming from the +calculus not directly from the rtin + + align:start position:0% +calculus not directly from the rtin + + + align:start position:0% +calculus not directly from the rtin +one of the ideas about how the + + align:start position:0% +one of the ideas about how the + + + align:start position:0% +one of the ideas about how the +geniculate body appeared was just that + + align:start position:0% +geniculate body appeared was just that + + + align:start position:0% +geniculate body appeared was just that +these sparse scattered + + align:start position:0% + + + + align:start position:0% + +projections that if some reduction of + + align:start position:0% +projections that if some reduction of + + + align:start position:0% +projections that if some reduction of +the calculus occurred they just sprouted + + align:start position:0% +the calculus occurred they just sprouted + + + align:start position:0% +the calculus occurred they just sprouted +more there and that was adapted to have + + align:start position:0% +more there and that was adapted to have + + + align:start position:0% +more there and that was adapted to have +a shorter root to the cortex so the + + align:start position:0% +a shorter root to the cortex so the + + + align:start position:0% +a shorter root to the cortex so the +genicular body evolved but be that as it + + align:start position:0% +genicular body evolved but be that as it + + + align:start position:0% +genicular body evolved but be that as it +may be the next structure then is the + + align:start position:0% +may be the next structure then is the + + + align:start position:0% +may be the next structure then is the +pretectal area and then finally + + align:start position:0% +pretectal area and then finally + + + align:start position:0% +pretectal area and then finally +spiculus or Optic + + align:start position:0% +spiculus or Optic + + + align:start position:0% +spiculus or Optic +tectum but for mammals we usually use + + align:start position:0% +tectum but for mammals we usually use + + + align:start position:0% +tectum but for mammals we usually use +the term spirit + + align:start position:0% +the term spirit + + + align:start position:0% +the term spirit +cicular all right so let's look at the + + align:start position:0% +cicular all right so let's look at the + + + align:start position:0% +cicular all right so let's look at the +geniculate body now we'll look at + + align:start position:0% +geniculate body now we'll look at + + + align:start position:0% +geniculate body now we'll look at +animals you know with this kind of layer + + align:start position:0% +animals you know with this kind of layer + + + align:start position:0% +animals you know with this kind of layer +but even more the here's the geniculate + + align:start position:0% +but even more the here's the geniculate + + + align:start position:0% +but even more the here's the geniculate +body of a monkey it's similar to a + + align:start position:0% +body of a monkey it's similar to a + + + align:start position:0% +body of a monkey it's similar to a +picture a color picture I took from + + align:start position:0% +picture a color picture I took from + + + align:start position:0% +picture a color picture I took from +Hubble David + + align:start position:0% +Hubble David + + + align:start position:0% +Hubble David +Hubble uh + + align:start position:0% +Hubble uh + + + align:start position:0% +Hubble uh +and from a book that he has online that + + align:start position:0% +and from a book that he has online that + + + align:start position:0% +and from a book that he has online that +anybody can + + align:start position:0% +anybody can + + + align:start position:0% +anybody can +download very nice book unfortunately + + align:start position:0% +download very nice book unfortunately + + + align:start position:0% +download very nice book unfortunately +David died just + + align:start position:0% +David died just + + + align:start position:0% +David died just +recently uh but he was a very productive + + align:start position:0% +recently uh but he was a very productive + + + align:start position:0% +recently uh but he was a very productive +visual + + align:start position:0% + + + + align:start position:0% + +neuroscientist who did many studies of + + align:start position:0% +neuroscientist who did many studies of + + + align:start position:0% +neuroscientist who did many studies of +both cat and + + align:start position:0% +both cat and + + + align:start position:0% +both cat and +monkey uh genicular stride system + + align:start position:0% +monkey uh genicular stride system + + + align:start position:0% +monkey uh genicular stride system +working mostly in visual + + align:start position:0% +working mostly in visual + + + align:start position:0% +working mostly in visual +cortex he did the work with ton weasel + + align:start position:0% +cortex he did the work with ton weasel + + + align:start position:0% +cortex he did the work with ton weasel +who's retired now but has been had a + + align:start position:0% +who's retired now but has been had a + + + align:start position:0% +who's retired now but has been had a +position at Rockefeller University for + + align:start position:0% +position at Rockefeller University for + + + align:start position:0% +position at Rockefeller University for +the + + align:start position:0% +the + + + align:start position:0% +the +last quite a few years after he left + + align:start position:0% +last quite a few years after he left + + + align:start position:0% +last quite a few years after he left +Harvard from his work with + + align:start position:0% +Harvard from his work with + + + align:start position:0% +Harvard from his work with +hu but here it shows you how they number + + align:start position:0% +hu but here it shows you how they number + + + align:start position:0% +hu but here it shows you how they number +these uh oh yeah how where did this + + align:start position:0% +these uh oh yeah how where did this + + + align:start position:0% +these uh oh yeah how where did this +horseshoe shape come from that's not + + align:start position:0% +horseshoe shape come from that's not + + + align:start position:0% +horseshoe shape come from that's not +what I'm showing + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +can you figure that + + align:start position:0% +can you figure that + + + align:start position:0% +can you figure that +out let's go back to the embryo it + + align:start position:0% +out let's go back to the embryo it + + + align:start position:0% +out let's go back to the embryo it +looked like + + align:start position:0% +looked like + + + align:start position:0% +looked like +this monkey the + + align:start position:0% +this monkey the + + + align:start position:0% +this monkey the +same this structure here grew and grew + + align:start position:0% +same this structure here grew and grew + + + align:start position:0% +same this structure here grew and grew +and grew so this structure got + + align:start position:0% +and grew so this structure got + + + align:start position:0% +and grew so this structure got +pushed this + + align:start position:0% +pushed this + + + align:start position:0% +pushed this +way okay + + align:start position:0% + + + + align:start position:0% + +so and the pulvinar in growing so + + align:start position:0% +so and the pulvinar in growing so + + + align:start position:0% +so and the pulvinar in growing so +big uh + + align:start position:0% +big uh + + + align:start position:0% +big uh +the thalamus in front of it also grew + + align:start position:0% +the thalamus in front of it also grew + + + align:start position:0% +the thalamus in front of it also grew +and so this thing that's on the side of + + align:start position:0% +and so this thing that's on the side of + + + align:start position:0% +and so this thing that's on the side of +the thalamus here do right here side of + + align:start position:0% +the thalamus here do right here side of + + + align:start position:0% +the thalamus here do right here side of +the phalus got pushed over like that and + + align:start position:0% +the phalus got pushed over like that and + + + align:start position:0% +the phalus got pushed over like that and +it also get got rotated so the genicular + + align:start position:0% +it also get got rotated so the genicular + + + align:start position:0% +it also get got rotated so the genicular +body ends up on the back of the + + align:start position:0% +body ends up on the back of the + + + align:start position:0% +body ends up on the back of the +phal so it goes that way and gets so + + align:start position:0% +phal so it goes that way and gets so + + + align:start position:0% +phal so it goes that way and gets so +this becomes like that and the optic + + align:start position:0% +this becomes like that and the optic + + + align:start position:0% +this becomes like that and the optic +crack which was out here is now under + + align:start position:0% +crack which was out here is now under + + + align:start position:0% +crack which was out here is now under +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +so that + + align:start position:0% +so that + + + align:start position:0% +so that +means this is the optic track + + align:start position:0% + + + + align:start position:0% + +surface those are the axon the tissue + + align:start position:0% +surface those are the axon the tissue + + + align:start position:0% +surface those are the axon the tissue +is torn off here but that's where the + + align:start position:0% +is torn off here but that's where the + + + align:start position:0% +is torn off here but that's where the +optic tract is but it's exactly top + + align:start position:0% +optic tract is but it's exactly top + + + align:start position:0% +optic tract is but it's exactly top +topologically it's the same as as this + + align:start position:0% +topologically it's the same as as this + + + align:start position:0% +topologically it's the same as as this +this picture + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +and then you have you see the way they + + align:start position:0% +and then you have you see the way they + + + align:start position:0% +and then you have you see the way they +number them they always start numbering + + align:start position:0% +number them they always start numbering + + + align:start position:0% +number them they always start numbering +them nearest the optic + + align:start position:0% +them nearest the optic + + + align:start position:0% +them nearest the optic +tract so one two notice the first two + + align:start position:0% +tract so one two notice the first two + + + align:start position:0% +tract so one two notice the first two +layers are larger + + align:start position:0% +layers are larger + + + align:start position:0% +layers are larger +cells and then the smaller cell layers + + align:start position:0% +cells and then the smaller cell layers + + + align:start position:0% +cells and then the smaller cell layers +or paral cellular + + align:start position:0% +or paral cellular + + + align:start position:0% +or paral cellular +layers 3 four five and + + align:start position:0% + + + + align:start position:0% + +six and again you have half of them they + + align:start position:0% +six and again you have half of them they + + + align:start position:0% +six and again you have half of them they +getting ipol in contr leral input and + + align:start position:0% +getting ipol in contr leral input and + + + align:start position:0% +getting ipol in contr leral input and +the other half are getting exal almost + + align:start position:0% +the other half are getting exal almost + + + align:start position:0% +the other half are getting exal almost +always the contralateral ey is + + align:start position:0% +always the contralateral ey is + + + align:start position:0% +always the contralateral ey is +projecting to the surface layer and to + + align:start position:0% +projecting to the surface layer and to + + + align:start position:0% +projecting to the surface layer and to +the last layer + + align:start position:0% +the last layer + + + align:start position:0% +the last layer +here and to one of these middle layers + + align:start position:0% +here and to one of these middle layers + + + align:start position:0% +here and to one of these middle layers +okay it varies a little bit among + + align:start position:0% +okay it varies a little bit among + + + align:start position:0% +okay it varies a little bit among +species here's a + + align:start position:0% +species here's a + + + align:start position:0% +species here's a +human and this is a human that uh + + align:start position:0% +human and this is a human that uh + + + align:start position:0% +human and this is a human that uh +picture that was donated to me by a + + align:start position:0% +picture that was donated to me by a + + + align:start position:0% +picture that was donated to me by a +former student who developed a silver + + align:start position:0% +former student who developed a silver + + + align:start position:0% +former student who developed a silver +stain that stained cell bodies gives you + + align:start position:0% +stain that stained cell bodies gives you + + + align:start position:0% +stain that stained cell bodies gives you +very high contrast picture this happens + + align:start position:0% +very high contrast picture this happens + + + align:start position:0% +very high contrast picture this happens +to be from a human case who had a + + align:start position:0% +to be from a human case who had a + + + align:start position:0% +to be from a human case who had a +pathology of one eye so the cells in + + align:start position:0% +pathology of one eye so the cells in + + + align:start position:0% +pathology of one eye so the cells in +the of the ipsilat ey that gets + + align:start position:0% +the of the ipsilat ey that gets + + + align:start position:0% +the of the ipsilat ey that gets +ipsilateral projections the cells are + + align:start position:0% +ipsilateral projections the cells are + + + align:start position:0% +ipsilateral projections the cells are +have shriveled a bit okay so this is one + + align:start position:0% +have shriveled a bit okay so this is one + + + align:start position:0% +have shriveled a bit okay so this is one +of the magnos cellular layers + + align:start position:0% +of the magnos cellular layers + + + align:start position:0% +of the magnos cellular layers +here and then here's the other + + align:start position:0% +here and then here's the other + + + align:start position:0% +here and then here's the other +controlateral layer and the last + + align:start position:0% +controlateral layer and the last + + + align:start position:0% +controlateral layer and the last +controlateral layer these are the layers + + align:start position:0% +controlateral layer these are the layers + + + align:start position:0% +controlateral layer these are the layers +getting IAL + + align:start position:0% +getting IAL + + + align:start position:0% +getting IAL +projections most of the other magnos + + align:start position:0% +projections most of the other magnos + + + align:start position:0% +projections most of the other magnos +layer we don't see + + align:start position:0% +layer we don't see + + + align:start position:0% +layer we don't see +here okay all of these cells + + align:start position:0% +here okay all of these cells + + + align:start position:0% +here okay all of these cells +here are all parts of that lateral + + align:start position:0% +here are all parts of that lateral + + + align:start position:0% +here are all parts of that lateral +Thalamus the pulvinar nucleus and + + align:start position:0% +Thalamus the pulvinar nucleus and + + + align:start position:0% +Thalamus the pulvinar nucleus and +there's a small part of it they call the + + align:start position:0% +there's a small part of it they call the + + + align:start position:0% +there's a small part of it they call the +the part that's the inferior pul + + align:start position:0% +the part that's the inferior pul + + + align:start position:0% +the part that's the inferior pul +pulvinar is similar to LP of the + + align:start position:0% +pulvinar is similar to LP of the + + + align:start position:0% +pulvinar is similar to LP of the +loaden and often they do name an LP too + + align:start position:0% +loaden and often they do name an LP too + + + align:start position:0% +loaden and often they do name an LP too +but it's the homology is not not always + + align:start position:0% +but it's the homology is not not always + + + align:start position:0% +but it's the homology is not not always +that clear okay so this is a picture + + align:start position:0% +that clear okay so this is a picture + + + align:start position:0% +that clear okay so this is a picture +from a very famous neuroanatomist in the + + align:start position:0% +from a very famous neuroanatomist in the + + + align:start position:0% +from a very famous neuroanatomist in the +early part of the 20th century lro + + align:start position:0% +early part of the 20th century lro + + + align:start position:0% +early part of the 20th century lro +Clark who didn't have access + + align:start position:0% + + + + align:start position:0% + +to beautiful optics for taking low power + + align:start position:0% +to beautiful optics for taking low power + + + align:start position:0% +to beautiful optics for taking low power +pictures and all that so he drew them + + align:start position:0% +pictures and all that so he drew them + + + align:start position:0% +pictures and all that so he drew them +and he drew these beautiful pictures in + + align:start position:0% +and he drew these beautiful pictures in + + + align:start position:0% +and he drew these beautiful pictures in +this case of many + + align:start position:0% +this case of many + + + align:start position:0% +this case of many +different uh primates and at that + + align:start position:0% +different uh primates and at that + + + align:start position:0% +different uh primates and at that +time they thought the Treo might be the + + align:start position:0% +time they thought the Treo might be the + + + align:start position:0% +time they thought the Treo might be the +most primitive primate it turns out to + + align:start position:0% +most primitive primate it turns out to + + + align:start position:0% +most primitive primate it turns out to +be similar to very primitive primates + + align:start position:0% +be similar to very primitive primates + + + align:start position:0% +be similar to very primitive primates +but it's actually an Inc + + align:start position:0% +but it's actually an Inc + + + align:start position:0% +but it's actually an Inc +work but you see the different patterns + + align:start position:0% +work but you see the different patterns + + + align:start position:0% +work but you see the different patterns +of + + align:start position:0% +of + + + align:start position:0% +of +lamination that occur in these different + + align:start position:0% +lamination that occur in these different + + + align:start position:0% +lamination that occur in these different +animals okay they don't all have + + align:start position:0% +animals okay they don't all have + + + align:start position:0% +animals okay they don't all have +identical + + align:start position:0% +identical + + + align:start position:0% +identical +structures okay + + align:start position:0% +structures okay + + + align:start position:0% +structures okay +binocular separation + + align:start position:0% +binocular separation + + + align:start position:0% +binocular separation +the anatomy underlying that binocular + + align:start position:0% +the anatomy underlying that binocular + + + align:start position:0% +the anatomy underlying that binocular +separation in the brain has evolved + + align:start position:0% +separation in the brain has evolved + + + align:start position:0% +separation in the brain has evolved +differently in different + + align:start position:0% + + + + align:start position:0% + +animals in these pictures + + align:start position:0% +animals in these pictures + + + align:start position:0% +animals in these pictures +the the old world monkey the greenon is + + align:start position:0% +the the old world monkey the greenon is + + + align:start position:0% +the the old world monkey the greenon is +is most similar to the + + align:start position:0% + + + + align:start position:0% + +human this particular this picture here + + align:start position:0% +human this particular this picture here + + + align:start position:0% +human this particular this picture here +is fairly close and level to that + + align:start position:0% +is fairly close and level to that + + + align:start position:0% +is fairly close and level to that +picture the the + + align:start position:0% +picture the the + + + align:start position:0% +picture the the +photograph okay so now I want to go to + + align:start position:0% +photograph okay so now I want to go to + + + align:start position:0% +photograph okay so now I want to go to +the rodent which they're usually using + + align:start position:0% +the rodent which they're usually using + + + align:start position:0% +the rodent which they're usually using +in laboratory work uh for lot of the + + align:start position:0% +in laboratory work uh for lot of the + + + align:start position:0% +in laboratory work uh for lot of the +studies of many + + align:start position:0% +studies of many + + + align:start position:0% +studies of many +systems and + + align:start position:0% +systems and + + + align:start position:0% +systems and +uh I want to I use side views and I show + + align:start position:0% +uh I want to I use side views and I show + + + align:start position:0% +uh I want to I use side views and I show +the op here here's a very simplified + + align:start position:0% +the op here here's a very simplified + + + align:start position:0% +the op here here's a very simplified +picture of it the outline here is a + + align:start position:0% +picture of it the outline here is a + + + align:start position:0% +picture of it the outline here is a +fairly accurate view a side view of the + + align:start position:0% +fairly accurate view a side view of the + + + align:start position:0% +fairly accurate view a side view of the +the upper brain stem of a hamster so you + + align:start position:0% +the upper brain stem of a hamster so you + + + align:start position:0% +the upper brain stem of a hamster so you +see the inferior calculus and spheri + + align:start position:0% +see the inferior calculus and spheri + + + align:start position:0% +see the inferior calculus and spheri +culus of the midbrain + + align:start position:0% +culus of the midbrain + + + align:start position:0% +culus of the midbrain +here this is all + + align:start position:0% + + + + align:start position:0% + +palus the dorsal palus would be all + + align:start position:0% +palus the dorsal palus would be all + + + align:start position:0% +palus the dorsal palus would be all +through here but the geniculate body + + align:start position:0% +through here but the geniculate body + + + align:start position:0% +through here but the geniculate body +here way out at the + + align:start position:0% +here way out at the + + + align:start position:0% +here way out at the +edge can here's the two parts dorsal and + + align:start position:0% +edge can here's the two parts dorsal and + + + align:start position:0% +edge can here's the two parts dorsal and +dental + + align:start position:0% +dental + + + align:start position:0% +dental +nuclei now remember I showed you I said + + align:start position:0% +nuclei now remember I showed you I said + + + align:start position:0% +nuclei now remember I showed you I said +that the lateral gen the ventral nucleus + + align:start position:0% +that the lateral gen the ventral nucleus + + + align:start position:0% +that the lateral gen the ventral nucleus +lateral geniculate is really subus well + + align:start position:0% +lateral geniculate is really subus well + + + align:start position:0% +lateral geniculate is really subus well +most of the sub remember it's a curv + + align:start position:0% +most of the sub remember it's a curv + + + align:start position:0% +most of the sub remember it's a curv +structure so this is at the lateral Edge + + align:start position:0% +structure so this is at the lateral Edge + + + align:start position:0% +structure so this is at the lateral Edge +so it's much higher up but then as we + + align:start position:0% +so it's much higher up but then as we + + + align:start position:0% +so it's much higher up but then as we +went deeper into the thalamus it would + + align:start position:0% +went deeper into the thalamus it would + + + align:start position:0% +went deeper into the thalamus it would +be way down here + + align:start position:0% +be way down here + + + align:start position:0% +be way down here +okay and what I show here is a little + + align:start position:0% +okay and what I show here is a little + + + align:start position:0% +okay and what I show here is a little +schematic of one little bundle of optic + + align:start position:0% +schematic of one little bundle of optic + + + align:start position:0% +schematic of one little bundle of optic +tract ACC coming from the kism up the + + align:start position:0% +tract ACC coming from the kism up the + + + align:start position:0% +tract ACC coming from the kism up the +side I don't show the + + align:start position:0% +side I don't show the + + + align:start position:0% +side I don't show the +terminations in the superism itic + + align:start position:0% +terminations in the superism itic + + + align:start position:0% +terminations in the superism itic +nucleus because those are different + + align:start position:0% +nucleus because those are different + + + align:start position:0% +nucleus because those are different +axons but I show that + + align:start position:0% +axons but I show that + + + align:start position:0% +axons but I show that +axons that go to the genicular body are + + align:start position:0% +axons that go to the genicular body are + + + align:start position:0% +axons that go to the genicular body are +usually branches of optic trct accents + + align:start position:0% +usually branches of optic trct accents + + + align:start position:0% +usually branches of optic trct accents +that go further that go to the tectum + + align:start position:0% +that go further that go to the tectum + + + align:start position:0% +that go further that go to the tectum +and often the pretectum as + + align:start position:0% +and often the pretectum as + + + align:start position:0% +and often the pretectum as +well I also + + align:start position:0% +well I also + + + align:start position:0% +well I also +show where the major input to the lp + + align:start position:0% +show where the major input to the lp + + + align:start position:0% +show where the major input to the lp +that provides the lp with visual + + align:start position:0% +that provides the lp with visual + + + align:start position:0% +that provides the lp with visual +information doesn't come from the retina + + align:start position:0% +information doesn't come from the retina + + + align:start position:0% +information doesn't come from the retina +even though there are a few projections + + align:start position:0% +even though there are a few projections + + + align:start position:0% +even though there are a few projections +there they come from the superficial or + + align:start position:0% +there they come from the superficial or + + + align:start position:0% +there they come from the superficial or +visual layers of the + + align:start position:0% +visual layers of the + + + align:start position:0% +visual layers of the +spiculus and IT projects both LP and to + + align:start position:0% +spiculus and IT projects both LP and to + + + align:start position:0% +spiculus and IT projects both LP and to +the outer layer of the lateral the + + align:start position:0% +the outer layer of the lateral the + + + align:start position:0% +the outer layer of the lateral the +ventral nucleus of the lateral genicular + + align:start position:0% +ventral nucleus of the lateral genicular + + + align:start position:0% +ventral nucleus of the lateral genicular +body so then + + align:start position:0% + + + + align:start position:0% + +uh I here's the question that I want to + + align:start position:0% +uh I here's the question that I want to + + + align:start position:0% +uh I here's the question that I want to +answer next the there are accents that + + align:start position:0% +answer next the there are accents that + + + align:start position:0% +answer next the there are accents that +leave the main optic cact and terminate + + align:start position:0% +leave the main optic cact and terminate + + + align:start position:0% +leave the main optic cact and terminate +in these small cell groups there up to + + align:start position:0% +in these small cell groups there up to + + + align:start position:0% +in these small cell groups there up to +three of + + align:start position:0% +three of + + + align:start position:0% +three of +them they're described as what kind of + + align:start position:0% +them they're described as what kind of + + + align:start position:0% +them they're described as what kind of +optic + + align:start position:0% +optic + + + align:start position:0% +optic +track the word is accessory optic track + + align:start position:0% +track the word is accessory optic track + + + align:start position:0% +track the word is accessory optic track +and this is a anatomical reconstruction + + align:start position:0% +and this is a anatomical reconstruction + + + align:start position:0% +and this is a anatomical reconstruction +of the + + align:start position:0% +of the + + + align:start position:0% +of the +hamster uh where I had labeled the + + align:start position:0% +hamster uh where I had labeled the + + + align:start position:0% +hamster uh where I had labeled the +axons all of the + + align:start position:0% +axons all of the + + + align:start position:0% +axons all of the +axons that I + + align:start position:0% +axons that I + + + align:start position:0% +axons that I +could which is most of + + align:start position:0% +could which is most of + + + align:start position:0% +could which is most of +them so I get the entire optic TR and I + + align:start position:0% +them so I get the entire optic TR and I + + + align:start position:0% +them so I get the entire optic TR and I +I put together Ser this is done from + + align:start position:0% +I put together Ser this is done from + + + align:start position:0% +I put together Ser this is done from +serial sections so you know the sections + + align:start position:0% +serial sections so you know the sections + + + align:start position:0% +serial sections so you know the sections +were actually like this but pretty close + + align:start position:0% +were actually like this but pretty close + + + align:start position:0% +were actually like this but pretty close +together okay and I then + + align:start position:0% + + + + align:start position:0% + +reconstructed the entire optic track + + align:start position:0% +reconstructed the entire optic track + + + align:start position:0% +reconstructed the entire optic track +from + + align:start position:0% +from + + + align:start position:0% +from +km to + + align:start position:0% +km to + + + align:start position:0% +km to +culas and this particular brain with the + + align:start position:0% +culas and this particular brain with the + + + align:start position:0% +culas and this particular brain with the +I was using degenerating X stains for + + align:start position:0% +I was using degenerating X stains for + + + align:start position:0% +I was using degenerating X stains for +degeneration I didn't get a good picture + + align:start position:0% +degeneration I didn't get a good picture + + + align:start position:0% +degeneration I didn't get a good picture +of the super kais nucleus so like most + + align:start position:0% +of the super kais nucleus so like most + + + align:start position:0% +of the super kais nucleus so like most +scientists I never lie with the data I + + align:start position:0% +scientists I never lie with the data I + + + align:start position:0% +scientists I never lie with the data I +present I don't show it okay but in fact + + align:start position:0% +present I don't show it okay but in fact + + + align:start position:0% +present I don't show it okay but in fact +with other techniques I could see it and + + align:start position:0% +with other techniques I could see it and + + + align:start position:0% +with other techniques I could see it and +it's right + + align:start position:0% +it's right + + + align:start position:0% +it's right +here all right and what I'm showing here + + align:start position:0% +here all right and what I'm showing here + + + align:start position:0% +here all right and what I'm showing here +is the accessory optic tract axons and + + align:start position:0% +is the accessory optic tract axons and + + + align:start position:0% +is the accessory optic tract axons and +you can see why they're called accessory + + align:start position:0% +you can see why they're called accessory + + + align:start position:0% +you can see why they're called accessory +optic tract they leave that main track + + align:start position:0% +optic tract they leave that main track + + + align:start position:0% +optic tract they leave that main track +that goes all the way from km to culas + + align:start position:0% +that goes all the way from km to culas + + + align:start position:0% +that goes all the way from km to culas +here here's some that leave just just + + align:start position:0% +here here's some that leave just just + + + align:start position:0% +here here's some that leave just just +below the cereal peduncle and they + + align:start position:0% +below the cereal peduncle and they + + + align:start position:0% +below the cereal peduncle and they +travel codly and they terminate medial + + align:start position:0% +travel codly and they terminate medial + + + align:start position:0% +travel codly and they terminate medial +to the + + align:start position:0% +to the + + + align:start position:0% +to the +peduncle right there to a nucleus that + + align:start position:0% +peduncle right there to a nucleus that + + + align:start position:0% +peduncle right there to a nucleus that +sort of hugs the medial side of the of + + align:start position:0% +sort of hugs the medial side of the of + + + align:start position:0% +sort of hugs the medial side of the of +the substantia and the coped unle + + align:start position:0% +the substantia and the coped unle + + + align:start position:0% +the substantia and the coped unle +and others do just travel codly below + + align:start position:0% +and others do just travel codly below + + + align:start position:0% +and others do just travel codly below +the phus here they just sort of peel off + + align:start position:0% +the phus here they just sort of peel off + + + align:start position:0% +the phus here they just sort of peel off +at the level of the ventrolateral + + align:start position:0% +at the level of the ventrolateral + + + align:start position:0% +at the level of the ventrolateral +genicular body and they terminate in a + + align:start position:0% +genicular body and they terminate in a + + + align:start position:0% +genicular body and they terminate in a +little nucleus here and some + + align:start position:0% +little nucleus here and some + + + align:start position:0% +little nucleus here and some +accents go down this way and get to this + + align:start position:0% +accents go down this way and get to this + + + align:start position:0% +accents go down this way and get to this +other way there's even some accents + + align:start position:0% +other way there's even some accents + + + align:start position:0% +other way there's even some accents +going in the other direction that's + + align:start position:0% +going in the other direction that's + + + align:start position:0% +going in the other direction that's +called the trans peduncular tract and + + align:start position:0% +called the trans peduncular tract and + + + align:start position:0% +called the trans peduncular tract and +then finally here's a little tract that + + align:start position:0% +then finally here's a little tract that + + + align:start position:0% +then finally here's a little tract that +goes from the pretectal area it leaves + + align:start position:0% +goes from the pretectal area it leaves + + + align:start position:0% +goes from the pretectal area it leaves +the main tract seems to go down to the + + align:start position:0% +the main tract seems to go down to the + + + align:start position:0% +the main tract seems to go down to the +lateral termin nucleus but it has + + align:start position:0% +lateral termin nucleus but it has + + + align:start position:0% +lateral termin nucleus but it has +another little nucleus there way out at + + align:start position:0% +another little nucleus there way out at + + + align:start position:0% +another little nucleus there way out at +the lateral edge of the + + align:start position:0% +the lateral edge of the + + + align:start position:0% +the lateral edge of the +pretectal so that's the accessory optic + + align:start position:0% +pretectal so that's the accessory optic + + + align:start position:0% +pretectal so that's the accessory optic +track very interesting system because + + align:start position:0% +track very interesting system because + + + align:start position:0% +track very interesting system because +all the cells in that tract respond to + + align:start position:0% +all the cells in that tract respond to + + + align:start position:0% +all the cells in that tract respond to +movement of the whole scene across the + + align:start position:0% +movement of the whole scene across the + + + align:start position:0% +movement of the whole scene across the +retina work no matter where you are in + + align:start position:0% +retina work no matter where you are in + + + align:start position:0% +retina work no matter where you are in +the retina you can the cells will detect + + align:start position:0% +the retina you can the cells will detect + + + align:start position:0% +the retina you can the cells will detect +movement in the same direction so when + + align:start position:0% +movement in the same direction so when + + + align:start position:0% +movement in the same direction so when +does that happen when the whole animal + + align:start position:0% +does that happen when the whole animal + + + align:start position:0% +does that happen when the whole animal +starts to fall it happens when the + + align:start position:0% +starts to fall it happens when the + + + align:start position:0% +starts to fall it happens when the +animal's locomoting and so there's + + align:start position:0% +animal's locomoting and so there's + + + align:start position:0% +animal's locomoting and so there's +streaming of the visual World Past his + + align:start position:0% + + + + align:start position:0% + +eyes and it functions as a kind + + align:start position:0% +eyes and it functions as a kind + + + align:start position:0% +eyes and it functions as a kind +of it does the same kind of functions + + align:start position:0% +of it does the same kind of functions + + + align:start position:0% +of it does the same kind of functions +that the distributor system does okay + + align:start position:0% +that the distributor system does okay + + + align:start position:0% +that the distributor system does okay +but it gives + + align:start position:0% +but it gives + + + align:start position:0% +but it gives +visual signals to indicate changes in + + align:start position:0% +visual signals to indicate changes in + + + align:start position:0% +visual signals to indicate changes in +head Direction and eye Direction okay + + align:start position:0% +head Direction and eye Direction okay + + + align:start position:0% +head Direction and eye Direction okay +very important for uh locomotion + + align:start position:0% +very important for uh locomotion + + + align:start position:0% +very important for uh locomotion +and very important if you need to keep + + align:start position:0% +and very important if you need to keep + + + align:start position:0% +and very important if you need to keep +track of your of head position all + + align:start position:0% +track of your of head position all + + + align:start position:0% +track of your of head position all +right so then I just want to show you + + align:start position:0% +right so then I just want to show you + + + align:start position:0% +right so then I just want to show you +that that what that + + align:start position:0% +that that what that + + + align:start position:0% +that that what that +reconstruction uh is doing by taking + + align:start position:0% +reconstruction uh is doing by taking + + + align:start position:0% +reconstruction uh is doing by taking +photographs of a similar brain now here + + align:start position:0% +photographs of a similar brain now here + + + align:start position:0% +photographs of a similar brain now here +I didn't label it here I did so here you + + align:start position:0% +I didn't label it here I did so here you + + + align:start position:0% +I didn't label it here I did so here you +can see because of the way I've shaped + + align:start position:0% +can see because of the way I've shaped + + + align:start position:0% +can see because of the way I've shaped +the light you can see major tracks cuz + + align:start position:0% +the light you can see major tracks cuz + + + align:start position:0% +the light you can see major tracks cuz +they're wider that's the lateral Factory + + align:start position:0% +they're wider that's the lateral Factory + + + align:start position:0% +they're wider that's the lateral Factory +track there's the optic + + align:start position:0% +track there's the optic + + + align:start position:0% +track there's the optic +track there's a pathway carrying + + align:start position:0% +track there's a pathway carrying + + + align:start position:0% +track there's a pathway carrying +auditory input from H brain up to the + + align:start position:0% +auditory input from H brain up to the + + + align:start position:0% +auditory input from H brain up to the +inferior + + align:start position:0% + + + + align:start position:0% + +calculus there's the bundle one of you + + align:start position:0% +calculus there's the bundle one of you + + + align:start position:0% +calculus there's the bundle one of you +see these two bundles here we cut those + + align:start position:0% +see these two bundles here we cut those + + + align:start position:0% +see these two bundles here we cut those +when we remove the cerebellum those are + + align:start position:0% +when we remove the cerebellum those are + + + align:start position:0% +when we remove the cerebellum those are +the cerebella pedes + + align:start position:0% + + + + align:start position:0% + +okay there's hypothal down below and + + align:start position:0% +okay there's hypothal down below and + + + align:start position:0% +okay there's hypothal down below and +there's where I + + align:start position:0% +there's where I + + + align:start position:0% +there's where I +uh when I remove the brain I tore the + + align:start position:0% +uh when I remove the brain I tore the + + + align:start position:0% +uh when I remove the brain I tore the +pituitary off right there okay that + + align:start position:0% +pituitary off right there okay that + + + align:start position:0% +pituitary off right there okay that +would be the mammary bodies at the codal + + align:start position:0% +would be the mammary bodies at the codal + + + align:start position:0% +would be the mammary bodies at the codal +end of the hypothal so here I've labeled + + align:start position:0% +end of the hypothal so here I've labeled + + + align:start position:0% +end of the hypothal so here I've labeled +them and I've labeled a few other + + align:start position:0% +them and I've labeled a few other + + + align:start position:0% +them and I've labeled a few other +structures so this structure here it's + + align:start position:0% +structures so this structure here it's + + + align:start position:0% +structures so this structure here it's +not bamus it's part of the end brain + + align:start position:0% +not bamus it's part of the end brain + + + align:start position:0% +not bamus it's part of the end brain +it's Corpus + + align:start position:0% +it's Corpus + + + align:start position:0% +it's Corpus +triot then I show you exactly where the + + align:start position:0% +triot then I show you exactly where the + + + align:start position:0% +triot then I show you exactly where the +geniculate body is + + align:start position:0% +geniculate body is + + + align:start position:0% +geniculate body is +is I know you say well how what do you + + align:start position:0% +is I know you say well how what do you + + + align:start position:0% +is I know you say well how what do you +mean exactly because I can see the + + align:start position:0% +mean exactly because I can see the + + + align:start position:0% +mean exactly because I can see the +Shadows there I can see them there I + + align:start position:0% +Shadows there I can see them there I + + + align:start position:0% +Shadows there I can see them there I +know that that's exactly the edge of the + + align:start position:0% +know that that's exactly the edge of the + + + align:start position:0% +know that that's exactly the edge of the +dorsal nucleus and this is the vental + + align:start position:0% +dorsal nucleus and this is the vental + + + align:start position:0% +dorsal nucleus and this is the vental +nucleus right below it there's the optic + + align:start position:0% +nucleus right below it there's the optic + + + align:start position:0% +nucleus right below it there's the optic +tract + + align:start position:0% + + + + align:start position:0% + +hypothalamus this big bundle here that + + align:start position:0% +hypothalamus this big bundle here that + + + align:start position:0% +hypothalamus this big bundle here that +emerges from behind the optic + + align:start position:0% +emerges from behind the optic + + + align:start position:0% +emerges from behind the optic +track those accents are course ing + + align:start position:0% +track those accents are course ing + + + align:start position:0% +track those accents are course ing +through the Corpus trium here but in the + + align:start position:0% +through the Corpus trium here but in the + + + align:start position:0% +through the Corpus trium here but in the +rodent they're all they're all separated + + align:start position:0% +rodent they're all they're all separated + + + align:start position:0% +rodent they're all they're all separated +a whole bunch of little separate bundles + + align:start position:0% +a whole bunch of little separate bundles + + + align:start position:0% +a whole bunch of little separate bundles +that collect in form the peduncle comes + + align:start position:0% +that collect in form the peduncle comes + + + align:start position:0% +that collect in form the peduncle comes +along the side of the dlon and then + + align:start position:0% +along the side of the dlon and then + + + align:start position:0% +along the side of the dlon and then +passes right on into the pontine region + + align:start position:0% +passes right on into the pontine region + + + align:start position:0% +passes right on into the pontine region +here and then when we study auditory + + align:start position:0% +here and then when we study auditory + + + align:start position:0% +here and then when we study auditory +system we'll learn that this is called + + align:start position:0% +system we'll learn that this is called + + + align:start position:0% +system we'll learn that this is called +the lateral liscus and that bump right + + align:start position:0% +the lateral liscus and that bump right + + + align:start position:0% +the lateral liscus and that bump right +there behind the Celler pet unes that's + + align:start position:0% +there behind the Celler pet unes that's + + + align:start position:0% +there behind the Celler pet unes that's +the clear nucleus and there's the stump + + align:start position:0% +the clear nucleus and there's the stump + + + align:start position:0% +the clear nucleus and there's the stump +of the eighth nerve right + + align:start position:0% +of the eighth nerve right + + + align:start position:0% +of the eighth nerve right +there so you one way is to to learn this + + align:start position:0% +there so you one way is to to learn this + + + align:start position:0% +there so you one way is to to learn this +stuff is to you know study + + align:start position:0% +stuff is to you know study + + + align:start position:0% +stuff is to you know study +reconstructions like this look at these + + align:start position:0% +reconstructions like this look at these + + + align:start position:0% +reconstructions like this look at these +photographs and try to learn to pick out + + align:start position:0% +photographs and try to learn to pick out + + + align:start position:0% +photographs and try to learn to pick out +the structures right now you should be + + align:start position:0% +the structures right now you should be + + + align:start position:0% +the structures right now you should be +able this is midbrain you should know + + align:start position:0% +able this is midbrain you should know + + + align:start position:0% +able this is midbrain you should know +what the calculi are you should know the + + align:start position:0% +what the calculi are you should know the + + + align:start position:0% +what the calculi are you should know the +optic tract and the + + align:start position:0% +optic tract and the + + + align:start position:0% +optic tract and the +hypothalamus + + align:start position:0% +hypothalamus + + + align:start position:0% +hypothalamus +here if I've already told you I've + + align:start position:0% +here if I've already told you I've + + + align:start position:0% +here if I've already told you I've +removed the hemispheres and the + + align:start position:0% +removed the hemispheres and the + + + align:start position:0% +removed the hemispheres and the +cerebellum then you know this has got to + + align:start position:0% +cerebellum then you know this has got to + + + align:start position:0% +cerebellum then you know this has got to +be below the hemispheres and there's + + align:start position:0% +be below the hemispheres and there's + + + align:start position:0% +be below the hemispheres and there's +only one big structure like that it's go + + align:start position:0% +only one big structure like that it's go + + + align:start position:0% +only one big structure like that it's go +the stum + + align:start position:0% +the stum + + + align:start position:0% +the stum +okay so one way is to cover those up and + + align:start position:0% + + + + align:start position:0% + +uh in the book you can it's done so you + + align:start position:0% +uh in the book you can it's done so you + + + align:start position:0% +uh in the book you can it's done so you +can just put a piece of paper and still + + align:start position:0% +can just put a piece of paper and still + + + align:start position:0% +can just put a piece of paper and still +see the line for the labels okay I want + + align:start position:0% +see the line for the labels okay I want + + + align:start position:0% +see the line for the labels okay I want +you to do that in your book cover up the + + align:start position:0% +you to do that in your book cover up the + + + align:start position:0% +you to do that in your book cover up the +labels and see if you can learn them + + align:start position:0% +labels and see if you can learn them + + + align:start position:0% +labels and see if you can learn them +learn what these structures are on this + + align:start position:0% +learn what these structures are on this + + + align:start position:0% +learn what these structures are on this +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +picture + + align:start position:0% +picture + + + align:start position:0% +picture +uh this kind of picture and this kind of + + align:start position:0% +uh this kind of picture and this kind of + + + align:start position:0% +uh this kind of picture and this kind of +reconstruction were very important to me + + align:start position:0% +reconstruction were very important to me + + + align:start position:0% +reconstruction were very important to me +from a lot for a lot of the experiments + + align:start position:0% +from a lot for a lot of the experiments + + + align:start position:0% +from a lot for a lot of the experiments +I did because I needed to do + + align:start position:0% +I did because I needed to do + + + align:start position:0% +I did because I needed to do +neurosurgery where I would open up the + + align:start position:0% +neurosurgery where I would open up the + + + align:start position:0% +neurosurgery where I would open up the +brain of course I would only see a small + + align:start position:0% +brain of course I would only see a small + + + align:start position:0% +brain of course I would only see a small +part but I learned the landmark so well + + align:start position:0% +part but I learned the landmark so well + + + align:start position:0% +part but I learned the landmark so well +that I could open it up and also using + + align:start position:0% +that I could open it up and also using + + + align:start position:0% +that I could open it up and also using +blood vessels I could see these + + align:start position:0% +blood vessels I could see these + + + align:start position:0% +blood vessels I could see these +structures and see the boundaries that + + align:start position:0% +structures and see the boundaries that + + + align:start position:0% +structures and see the boundaries that +way I could make injections or even + + align:start position:0% +way I could make injections or even + + + align:start position:0% +way I could make injections or even +lesions in just small + + align:start position:0% +lesions in just small + + + align:start position:0% +lesions in just small +regions all right this is another + + align:start position:0% +regions all right this is another + + + align:start position:0% +regions all right this is another +somewhat easier view where I have the + + align:start position:0% +somewhat easier view where I have the + + + align:start position:0% +somewhat easier view where I have the +adult brain on the left and the brain of + + align:start position:0% +adult brain on the left and the brain of + + + align:start position:0% +adult brain on the left and the brain of +a newborn on the right and here I've + + align:start position:0% +a newborn on the right and here I've + + + align:start position:0% +a newborn on the right and here I've +just labeled major parts of the + + align:start position:0% +just labeled major parts of the + + + align:start position:0% +just labeled major parts of the +brain + + align:start position:0% +brain + + + align:start position:0% +brain +Factory B NE + + align:start position:0% +Factory B NE + + + align:start position:0% +Factory B NE +cortex Superior calculi inferior + + align:start position:0% +cortex Superior calculi inferior + + + align:start position:0% +cortex Superior calculi inferior +calculi + + align:start position:0% +calculi + + + align:start position:0% +calculi +cerebellum and the Medela + + align:start position:0% +cerebellum and the Medela + + + align:start position:0% +cerebellum and the Medela +blada the codal part of the hindbrain + + align:start position:0% +blada the codal part of the hindbrain + + + align:start position:0% +blada the codal part of the hindbrain +the Ral part of the hind brain is + + align:start position:0% +the Ral part of the hind brain is + + + align:start position:0% +the Ral part of the hind brain is +underneath the cerebellum cerebellum is + + align:start position:0% +underneath the cerebellum cerebellum is + + + align:start position:0% +underneath the cerebellum cerebellum is +part of it but what I want you to note + + align:start position:0% +part of it but what I want you to note + + + align:start position:0% +part of it but what I want you to note +here look at the cerebellum here in the + + align:start position:0% +here look at the cerebellum here in the + + + align:start position:0% +here look at the cerebellum here in the +baby it's just this tiny little collar + + align:start position:0% +baby it's just this tiny little collar + + + align:start position:0% +baby it's just this tiny little collar +behind the inferior + + align:start position:0% +behind the inferior + + + align:start position:0% +behind the inferior +cus it's mainly + + align:start position:0% +cus it's mainly + + + align:start position:0% +cus it's mainly +developing with huge numbers of cell + + align:start position:0% +developing with huge numbers of cell + + + align:start position:0% +developing with huge numbers of cell +migrations from the romic lip to the hbr + + align:start position:0% +migrations from the romic lip to the hbr + + + align:start position:0% +migrations from the romic lip to the hbr +just developing in the newborn + + align:start position:0% +just developing in the newborn + + + align:start position:0% +just developing in the newborn +hamster it's born remember at a stage + + align:start position:0% +hamster it's born remember at a stage + + + align:start position:0% +hamster it's born remember at a stage +it's like a 2 and 1/2 to 3mon human + + align:start position:0% +it's like a 2 and 1/2 to 3mon human + + + align:start position:0% +it's like a 2 and 1/2 to 3mon human +fetus which means that a 2 and 1/2 month + + align:start position:0% +fetus which means that a 2 and 1/2 month + + + align:start position:0% +fetus which means that a 2 and 1/2 month +human fetus looks just like this + + align:start position:0% +human fetus looks just like this + + + align:start position:0% +human fetus looks just like this +too cerebellum grows mostly after that + + align:start position:0% +too cerebellum grows mostly after that + + + align:start position:0% +too cerebellum grows mostly after that +time + + align:start position:0% +time + + + align:start position:0% +time +okay so one way to study that + + align:start position:0% +okay so one way to study that + + + align:start position:0% +okay so one way to study that +just use the book and make yourself a + + align:start position:0% +just use the book and make yourself a + + + align:start position:0% +just use the book and make yourself a +card and cover those up and make sure + + align:start position:0% +card and cover those up and make sure + + + align:start position:0% +card and cover those up and make sure +you know what all those pointers are + + align:start position:0% +you know what all those pointers are + + + align:start position:0% +you know what all those pointers are +pointing towards this one should be the + + align:start position:0% +pointing towards this one should be the + + + align:start position:0% +pointing towards this one should be the +easiest this one will be a little + + align:start position:0% +easiest this one will be a little + + + align:start position:0% +easiest this one will be a little +harder all + + align:start position:0% + + + + align:start position:0% + +right can somebody tell me what e + + align:start position:0% +right can somebody tell me what e + + + align:start position:0% +right can somebody tell me what e +is + + align:start position:0% +is + + + align:start position:0% +is +optic crack and what about what about + + align:start position:0% +optic crack and what about what about + + + align:start position:0% +optic crack and what about what about +D + + align:start position:0% +D + + + align:start position:0% +D +hypothalamus uh can anybody do + + align:start position:0% + + + + align:start position:0% + +c p right cereal cerebral pedon p means + + align:start position:0% +c p right cereal cerebral pedon p means + + + align:start position:0% +c p right cereal cerebral pedon p means +cereal it's + + align:start position:0% +cereal it's + + + align:start position:0% +cereal it's +always it's it's always the abbreviation + + align:start position:0% +always it's it's always the abbreviation + + + align:start position:0% +always it's it's always the abbreviation +for Cal pet unle is PE and I didn't + + align:start position:0% +for Cal pet unle is PE and I didn't + + + align:start position:0% +for Cal pet unle is PE and I didn't +label the PS + + align:start position:0% +label the PS + + + align:start position:0% +label the PS +but this would be the ponts right + + align:start position:0% +but this would be the ponts right + + + align:start position:0% +but this would be the ponts right +there this is the trapezoid body which I + + align:start position:0% +there this is the trapezoid body which I + + + align:start position:0% +there this is the trapezoid body which I +don't name Co + + align:start position:0% +don't name Co + + + align:start position:0% +don't name Co +nucleus cerebel + + align:start position:0% +nucleus cerebel + + + align:start position:0% +nucleus cerebel +peduncle and latal liscus but I just + + align:start position:0% +peduncle and latal liscus but I just + + + align:start position:0% +peduncle and latal liscus but I just +labeled the ones here + + align:start position:0% +labeled the ones here + + + align:start position:0% +labeled the ones here +that you know we might put a a diagram + + align:start position:0% +that you know we might put a a diagram + + + align:start position:0% +that you know we might put a a diagram +like this we wouldn't put all those + + align:start position:0% +like this we wouldn't put all those + + + align:start position:0% +like this we wouldn't put all those +things but we might ask you to do a give + + align:start position:0% +things but we might ask you to do a give + + + align:start position:0% +things but we might ask you to do a give +you a bunch of terms and say well which + + align:start position:0% +you a bunch of terms and say well which + + + align:start position:0% +you a bunch of terms and say well which +one goes with each of these letters you + + align:start position:0% +one goes with each of these letters you + + + align:start position:0% +one goes with each of these letters you +know so if you're at least familiar with + + align:start position:0% +know so if you're at least familiar with + + + align:start position:0% +know so if you're at least familiar with +it you would be able to do + + align:start position:0% + + + + align:start position:0% + +that okay and then here the same thing + + align:start position:0% +that okay and then here the same thing + + + align:start position:0% +that okay and then here the same thing +here I've covered + + align:start position:0% + + + + align:start position:0% + +up just name them off for me what's + + align:start position:0% +up just name them off for me what's + + + align:start position:0% +up just name them off for me what's +that what's + + align:start position:0% +that what's + + + align:start position:0% +that what's +this okay or Cal hemisphere either one + + align:start position:0% +this okay or Cal hemisphere either one + + + align:start position:0% +this okay or Cal hemisphere either one +would be proper what's + + align:start position:0% +would be proper what's + + + align:start position:0% +would be proper what's +that okay notice most of it + + align:start position:0% +that okay notice most of it + + + align:start position:0% +that okay notice most of it +exposed here here only part of it's + + align:start position:0% +exposed here here only part of it's + + + align:start position:0% +exposed here here only part of it's +exposed and in most animals with an + + align:start position:0% +exposed and in most animals with an + + + align:start position:0% +exposed and in most animals with an +either bigger bigger hemospheres you + + align:start position:0% +either bigger bigger hemospheres you + + + align:start position:0% +either bigger bigger hemospheres you +don't even see the membrane from a dors + + align:start position:0% +don't even see the membrane from a dors + + + align:start position:0% +don't even see the membrane from a dors +of view like that okay and this + + align:start position:0% +of view like that okay and this + + + align:start position:0% +of view like that okay and this +one + + align:start position:0% +one + + + align:start position:0% +one +cerebellum + + align:start position:0% +cerebellum + + + align:start position:0% +cerebellum +this CLE hind brain or medel BL + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +oh I'm asking you another question here + + align:start position:0% +oh I'm asking you another question here + + + align:start position:0% +oh I'm asking you another question here +about naming the structures I said what + + align:start position:0% +about naming the structures I said what + + + align:start position:0% +about naming the structures I said what +would make this more difficult during a + + align:start position:0% +would make this more difficult during a + + + align:start position:0% +would make this more difficult during a +Neurosurgical + + align:start position:0% +Neurosurgical + + + align:start position:0% +Neurosurgical +procedure think about + + align:start position:0% +procedure think about + + + align:start position:0% +procedure think about +it in a Neurosurgical procedure you + + align:start position:0% +it in a Neurosurgical procedure you + + + align:start position:0% +it in a Neurosurgical procedure you +don't expose such a huge amount of the + + align:start position:0% +don't expose such a huge amount of the + + + align:start position:0% +don't expose such a huge amount of the +brain you only can you know you want to + + align:start position:0% +brain you only can you know you want to + + + align:start position:0% +brain you only can you know you want to +make a + + align:start position:0% +make a + + + align:start position:0% +make a +smaller window as possible so you don't + + align:start position:0% +smaller window as possible so you don't + + + align:start position:0% +smaller window as possible so you don't +damage so much + + align:start position:0% +damage so much + + + align:start position:0% +damage so much +tissue so that's the first + + align:start position:0% +tissue so that's the first + + + align:start position:0% +tissue so that's the first +problem and the second thing is there's + + align:start position:0% +problem and the second thing is there's + + + align:start position:0% +problem and the second thing is there's +a lot of blood + + align:start position:0% +a lot of blood + + + align:start position:0% +a lot of blood +vessels in fact you have to be very + + align:start position:0% +vessels in fact you have to be very + + + align:start position:0% +vessels in fact you have to be very +careful not to go through any really big + + align:start position:0% +careful not to go through any really big + + + align:start position:0% +careful not to go through any really big +ones because you'll get so much bleeding + + align:start position:0% +ones because you'll get so much bleeding + + + align:start position:0% +ones because you'll get so much bleeding +that you'll be spending all your time + + align:start position:0% +that you'll be spending all your time + + + align:start position:0% +that you'll be spending all your time +stopping the bleeding and you do spend a + + align:start position:0% +stopping the bleeding and you do spend a + + + align:start position:0% +stopping the bleeding and you do spend a +lot of time doing that neuros + + align:start position:0% +lot of time doing that neuros + + + align:start position:0% +lot of time doing that neuros +surgery although now we have a method to + + align:start position:0% +surgery although now we have a method to + + + align:start position:0% +surgery although now we have a method to +apply that does stop the bleeding of all + + align:start position:0% +apply that does stop the bleeding of all + + + align:start position:0% +apply that does stop the bleeding of all +the smaller + + align:start position:0% +the smaller + + + align:start position:0% +the smaller +vessels just not the huge ones + + align:start position:0% + + + + align:start position:0% + +okay look at these other pictures for + + align:start position:0% +okay look at these other pictures for + + + align:start position:0% +okay look at these other pictures for +next time and just see if you can figure + + align:start position:0% +next time and just see if you can figure + + + align:start position:0% +next time and just see if you can figure +out what's exposed okay I use different + + align:start position:0% +out what's exposed okay I use different + + + align:start position:0% +out what's exposed okay I use different +lights lighting just so you this is that + + align:start position:0% +lights lighting just so you this is that + + + align:start position:0% +lights lighting just so you this is that +same kind of brain stem that you see + + align:start position:0% +same kind of brain stem that you see + + + align:start position:0% +same kind of brain stem that you see +here with the hemispheres + + align:start position:0% +here with the hemispheres + + + align:start position:0% +here with the hemispheres +removed and you can see various + + align:start position:0% +removed and you can see various + + + align:start position:0% +removed and you can see various +structures here I've done a little more + + align:start position:0% +structures here I've done a little more + + + align:start position:0% +structures here I've done a little more +removal up front here let see if you can + + align:start position:0% +removal up front here let see if you can + + + align:start position:0% +removal up front here let see if you can +figure out what those things are now I + + align:start position:0% +figure out what those things are now I + + + align:start position:0% +figure out what those things are now I +do name a lot of them in the book I + + align:start position:0% +do name a lot of them in the book I + + + align:start position:0% +do name a lot of them in the book I +don't think I show all these pictures in + + align:start position:0% +don't think I show all these pictures in + + + align:start position:0% +don't think I show all these pictures in +the book but you I wanted you to see how + + align:start position:0% +the book but you I wanted you to see how + + + align:start position:0% +the book but you I wanted you to see how +by if you adjust the light a little bit + + align:start position:0% +by if you adjust the light a little bit + + + align:start position:0% +by if you adjust the light a little bit +you can actually see boundaries like + + align:start position:0% +you can actually see boundaries like + + + align:start position:0% +you can actually see boundaries like +look at this one there's the + + align:start position:0% +look at this one there's the + + + align:start position:0% +look at this one there's the +spiculus there's the pretective if you + + align:start position:0% +spiculus there's the pretective if you + + + align:start position:0% +spiculus there's the pretective if you +look at this one even clearer there's + + align:start position:0% +look at this one even clearer there's + + + align:start position:0% +look at this one even clearer there's +the boundary between spiculus and + + align:start position:0% +the boundary between spiculus and + + + align:start position:0% +the boundary between spiculus and +pretectum and look at how clear this + + align:start position:0% +pretectum and look at how clear this + + + align:start position:0% +pretectum and look at how clear this +boundary is and this + + align:start position:0% + + + + align:start position:0% + +one pretectal areia + + align:start position:0% +one pretectal areia + + + align:start position:0% +one pretectal areia +LP geniculate + + align:start position:0% + + + + align:start position:0% + +body that is the bundle carrying + + align:start position:0% +body that is the bundle carrying + + + align:start position:0% +body that is the bundle carrying +information from the amydala which we + + align:start position:0% +information from the amydala which we + + + align:start position:0% +information from the amydala which we +will be studying soon + + align:start position:0% +will be studying soon + + + align:start position:0% +will be studying soon +okay and this just shows what it looks + + align:start position:0% +okay and this just shows what it looks + + + align:start position:0% +okay and this just shows what it looks +like in a the embryo when it just the + + align:start position:0% +like in a the embryo when it just the + + + align:start position:0% +like in a the embryo when it just the +accents have first Grown back to the + + align:start position:0% +accents have first Grown back to the + + + align:start position:0% +accents have first Grown back to the +tectum very straight pathway back to + + align:start position:0% + + + + align:start position:0% + +detecton + + align:start position:0% +detecton + + + align:start position:0% +detecton +and we'll next time we will start in + + align:start position:0% +and we'll next time we will start in + + + align:start position:0% +and we'll next time we will start in +this area and talk about the midbrain a + + align:start position:0% +this area and talk about the midbrain a + + + align:start position:0% +this area and talk about the midbrain a +little more just to look at these + + align:start position:0% +little more just to look at these + + + align:start position:0% +little more just to look at these +pictures but they're in the book uh + + align:start position:0% +pictures but they're in the book uh + + + align:start position:0% +pictures but they're in the book uh +they'll give you a chance to ask about + + align:start position:0% +they'll give you a chance to ask about + + + align:start position:0% +they'll give you a chance to ask about +and uh we'll go through some of these + + align:start position:0% +and uh we'll go through some of these + + + align:start position:0% +and uh we'll go through some of these +before we go on to the Endra + + align:start position:0% +before we go on to the Endra + + + align:start position:0% +before we go on to the Endra +okay \ No newline at end of file diff --git a/8umr89M6YgQ.txt b/8umr89M6YgQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..d48cf7817e38fe2bf711f2c3cf33bd34fa450e7e --- /dev/null +++ b/8umr89M6YgQ.txt @@ -0,0 +1,1963 @@ +align:start position:0% + +let's talk a little bit + + align:start position:0% +let's talk a little bit + + + align:start position:0% +let's talk a little bit +more about some of the parameters that + + align:start position:0% +more about some of the parameters that + + + align:start position:0% +more about some of the parameters that +govern the chemical reactions + + align:start position:0% +govern the chemical reactions + + + align:start position:0% +govern the chemical reactions +in a cell and indeed any chemical + + align:start position:0% +in a cell and indeed any chemical + + + align:start position:0% +in a cell and indeed any chemical +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +all chemical reactions are governed by + + align:start position:0% +all chemical reactions are governed by + + + align:start position:0% +all chemical reactions are governed by +something called + + align:start position:0% +something called + + + align:start position:0% +something called +free or usable energy + + align:start position:0% +free or usable energy + + + align:start position:0% +free or usable energy +so let us write that reactions + + align:start position:0% +so let us write that reactions + + + align:start position:0% +so let us write that reactions +are governed by free energy + + align:start position:0% +are governed by free energy + + + align:start position:0% +are governed by free energy +where free really means usable and this + + align:start position:0% +where free really means usable and this + + + align:start position:0% +where free really means usable and this +free energy gets a special symbol + + align:start position:0% +free energy gets a special symbol + + + align:start position:0% +free energy gets a special symbol +it is called g and the difference + + align:start position:0% +it is called g and the difference + + + align:start position:0% +it is called g and the difference +in free energy is what's really + + align:start position:0% +in free energy is what's really + + + align:start position:0% +in free energy is what's really +important + + align:start position:0% +important + + + align:start position:0% +important +and so we write delta g delta g + + align:start position:0% +and so we write delta g delta g + + + align:start position:0% +and so we write delta g delta g +comes from a key thermodynamic equation + + align:start position:0% +comes from a key thermodynamic equation + + + align:start position:0% +comes from a key thermodynamic equation +such that the difference in the free + + align:start position:0% +such that the difference in the free + + + align:start position:0% +such that the difference in the free +energy of a reaction + + align:start position:0% +energy of a reaction + + + align:start position:0% +energy of a reaction +has to do with a difference in enthalpy + + align:start position:0% +has to do with a difference in enthalpy + + + align:start position:0% +has to do with a difference in enthalpy +or total energy minus + + align:start position:0% +or total energy minus + + + align:start position:0% +or total energy minus +temperature times the difference + + align:start position:0% +temperature times the difference + + + align:start position:0% +temperature times the difference +in useless energy so this is the + + align:start position:0% +in useless energy so this is the + + + align:start position:0% +in useless energy so this is the +free energy this is the total energy + + align:start position:0% +free energy this is the total energy + + + align:start position:0% +free energy this is the total energy +and this is the temperature multiplied + + align:start position:0% +and this is the temperature multiplied + + + align:start position:0% +and this is the temperature multiplied +by + + align:start position:0% +by + + + align:start position:0% +by +the unusable or free the unusable + + align:start position:0% +the unusable or free the unusable + + + align:start position:0% +the unusable or free the unusable +energy or entropy + + align:start position:0% +energy or entropy + + + align:start position:0% +energy or entropy +okay so this delta g minus delta equals + + align:start position:0% +okay so this delta g minus delta equals + + + align:start position:0% +okay so this delta g minus delta equals +delta h minus t delta + + align:start position:0% +delta h minus t delta + + + align:start position:0% +delta h minus t delta +s is an equation that you should have + + align:start position:0% +s is an equation that you should have + + + align:start position:0% +s is an equation that you should have +seen + + align:start position:0% +seen + + + align:start position:0% +seen +and at least know the terms associated + + align:start position:0% +and at least know the terms associated + + + align:start position:0% +and at least know the terms associated +when we think about a chemical reaction + + align:start position:0% +when we think about a chemical reaction + + + align:start position:0% +when we think about a chemical reaction +such that some reactants can either + + align:start position:0% +such that some reactants can either + + + align:start position:0% +such that some reactants can either +become products reactants becoming + + align:start position:0% +become products reactants becoming + + + align:start position:0% +become products reactants becoming +products + + align:start position:0% +products + + + align:start position:0% +products +or products can become + + align:start position:0% +or products can become + + + align:start position:0% +or products can become +what were reactants so chemical + + align:start position:0% +what were reactants so chemical + + + align:start position:0% +what were reactants so chemical +reactions can go in both directions + + align:start position:0% +reactions can go in both directions + + + align:start position:0% +reactions can go in both directions +there are three things that can happen + + align:start position:0% +there are three things that can happen + + + align:start position:0% +there are three things that can happen +to free energy during this reaction + + align:start position:0% +to free energy during this reaction + + + align:start position:0% +to free energy during this reaction +either one way or the other delta g + + align:start position:0% +either one way or the other delta g + + + align:start position:0% +either one way or the other delta g +can be negative in which case + + align:start position:0% +can be negative in which case + + + align:start position:0% +can be negative in which case +energy is released during the reaction + + align:start position:0% +energy is released during the reaction + + + align:start position:0% +energy is released during the reaction +and the reaction may + + align:start position:0% +and the reaction may + + + align:start position:0% +and the reaction may +proceed it may even be spontaneous + + align:start position:0% +proceed it may even be spontaneous + + + align:start position:0% +proceed it may even be spontaneous +on the other hand delta g might be + + align:start position:0% +on the other hand delta g might be + + + align:start position:0% +on the other hand delta g might be +positive + + align:start position:0% +positive + + + align:start position:0% +positive +delta g might be positive in which case + + align:start position:0% +delta g might be positive in which case + + + align:start position:0% +delta g might be positive in which case +energy is required in order for the + + align:start position:0% +energy is required in order for the + + + align:start position:0% +energy is required in order for the +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +to proceed and the third possibility is + + align:start position:0% +to proceed and the third possibility is + + + align:start position:0% +to proceed and the third possibility is +that delta g is + + align:start position:0% +that delta g is + + + align:start position:0% +that delta g is +zero and if delta g is zero + + align:start position:0% +zero and if delta g is zero + + + align:start position:0% +zero and if delta g is zero +the reaction is said to be at + + align:start position:0% +the reaction is said to be at + + + align:start position:0% +the reaction is said to be at +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +where the reactants + + align:start position:0% +where the reactants + + + align:start position:0% +where the reactants +become products at the same rate as the + + align:start position:0% +become products at the same rate as the + + + align:start position:0% +become products at the same rate as the +products + + align:start position:0% +products + + + align:start position:0% +products +go back and become reactants + + align:start position:0% +go back and become reactants + + + align:start position:0% +go back and become reactants +so everything is kind of in balance + + align:start position:0% +so everything is kind of in balance + + + align:start position:0% +so everything is kind of in balance +those are your three + + align:start position:0% +those are your three + + + align:start position:0% +those are your three +possibilities and it's important to + + align:start position:0% +possibilities and it's important to + + + align:start position:0% +possibilities and it's important to +think about them + + align:start position:0% +think about them + + + align:start position:0% +think about them +for all biological chemical reactions + + align:start position:0% +for all biological chemical reactions + + + align:start position:0% +for all biological chemical reactions +so here i'm going to lay it out for you + + align:start position:0% +so here i'm going to lay it out for you + + + align:start position:0% +so here i'm going to lay it out for you +again + + align:start position:0% +again + + + align:start position:0% +again +and think about free energy and reaction + + align:start position:0% +and think about free energy and reaction + + + align:start position:0% +and think about free energy and reaction +kinetics + + align:start position:0% +kinetics + + + align:start position:0% +kinetics +for here substrate becoming products + + align:start position:0% +for here substrate becoming products + + + align:start position:0% +for here substrate becoming products +reactants or substrate ros used + + align:start position:0% +reactants or substrate ros used + + + align:start position:0% +reactants or substrate ros used +interchangeably + + align:start position:0% +interchangeably + + + align:start position:0% +interchangeably +free energy as defined for you + + align:start position:0% +free energy as defined for you + + + align:start position:0% +free energy as defined for you +and here energy release + + align:start position:0% +and here energy release + + + align:start position:0% +and here energy release +when delta g is negative these reactions + + align:start position:0% +when delta g is negative these reactions + + + align:start position:0% +when delta g is negative these reactions +can also be called exogonic and they may + + align:start position:0% +can also be called exogonic and they may + + + align:start position:0% +can also be called exogonic and they may +occur spontaneously + + align:start position:0% + + + + align:start position:0% + +the flip endergonic reactions + + align:start position:0% +the flip endergonic reactions + + + align:start position:0% +the flip endergonic reactions +require energy to proceed where delta g + + align:start position:0% +require energy to proceed where delta g + + + align:start position:0% +require energy to proceed where delta g +is positive and delta g + + align:start position:0% +is positive and delta g + + + align:start position:0% +is positive and delta g +zero the reaction is at equilibrium + + align:start position:0% +zero the reaction is at equilibrium + + + align:start position:0% +zero the reaction is at equilibrium +the production of the products + + align:start position:0% +the production of the products + + + align:start position:0% +the production of the products +is the same as the back reaction to the + + align:start position:0% +is the same as the back reaction to the + + + align:start position:0% +is the same as the back reaction to the +production or the regeneration of the + + align:start position:0% +production or the regeneration of the + + + align:start position:0% +production or the regeneration of the +reactants + + align:start position:0% +reactants + + + align:start position:0% +reactants +good + + align:start position:0% + + + + align:start position:0% + +we can portray the thermodynamics + + align:start position:0% +we can portray the thermodynamics + + + align:start position:0% +we can portray the thermodynamics +the free energy changes + + align:start position:0% +the free energy changes + + + align:start position:0% +the free energy changes +using various graphs and + + align:start position:0% +using various graphs and + + + align:start position:0% +using various graphs and +delta g negative reactions typically are + + align:start position:0% +delta g negative reactions typically are + + + align:start position:0% +delta g negative reactions typically are +shown + + align:start position:0% +shown + + + align:start position:0% +shown +as the the schematic as a ball rolling + + align:start position:0% +as the the schematic as a ball rolling + + + align:start position:0% +as the the schematic as a ball rolling +down a hill + + align:start position:0% +down a hill + + + align:start position:0% +down a hill +or you can draw a graph where you can + + align:start position:0% +or you can draw a graph where you can + + + align:start position:0% +or you can draw a graph where you can +see that if you plot energy + + align:start position:0% +see that if you plot energy + + + align:start position:0% +see that if you plot energy +against time you see that there's a + + align:start position:0% +against time you see that there's a + + + align:start position:0% +against time you see that there's a +certain amount of energy released as the + + align:start position:0% +certain amount of energy released as the + + + align:start position:0% +certain amount of energy released as the +products are formed + + align:start position:0% +products are formed + + + align:start position:0% +products are formed +and the flip where delta g is positive + + align:start position:0% +and the flip where delta g is positive + + + align:start position:0% +and the flip where delta g is positive +when you need energy for the reaction to + + align:start position:0% +when you need energy for the reaction to + + + align:start position:0% +when you need energy for the reaction to +go + + align:start position:0% +go + + + align:start position:0% +go +then you see that the amount of energy + + align:start position:0% +then you see that the amount of energy + + + align:start position:0% +then you see that the amount of energy +required + + align:start position:0% +required + + + align:start position:0% +required +is a positive input that has to be that + + align:start position:0% +is a positive input that has to be that + + + align:start position:0% +is a positive input that has to be that +has to take place + + align:start position:0% +has to take place + + + align:start position:0% +has to take place +okay + + align:start position:0% + + + + align:start position:0% + +but there is a catch here + + align:start position:0% +but there is a catch here + + + align:start position:0% +but there is a catch here +i mentioned that even if delta g is + + align:start position:0% +i mentioned that even if delta g is + + + align:start position:0% +i mentioned that even if delta g is +negative + + align:start position:0% +negative + + + align:start position:0% +negative +sometimes a reaction will not proceed + + align:start position:0% +sometimes a reaction will not proceed + + + align:start position:0% +sometimes a reaction will not proceed +it needs a little push before it will + + align:start position:0% +it needs a little push before it will + + + align:start position:0% +it needs a little push before it will +proceed + + align:start position:0% +proceed + + + align:start position:0% +proceed +and the little push is energy and it's + + align:start position:0% +and the little push is energy and it's + + + align:start position:0% +and the little push is energy and it's +called activation energy + + align:start position:0% +called activation energy + + + align:start position:0% +called activation energy +so we can write you may need + + align:start position:0% +so we can write you may need + + + align:start position:0% +so we can write you may need +activation energy even + + align:start position:0% +activation energy even + + + align:start position:0% +activation energy even +with delta g negative less than zero + + align:start position:0% + + + + align:start position:0% + +this is called an energy barrier you can + + align:start position:0% +this is called an energy barrier you can + + + align:start position:0% +this is called an energy barrier you can +think of it as a ball + + align:start position:0% +think of it as a ball + + + align:start position:0% +think of it as a ball +sitting at the top of a hill and the + + align:start position:0% +sitting at the top of a hill and the + + + align:start position:0% +sitting at the top of a hill and the +ball really could roll down the hill + + align:start position:0% +ball really could roll down the hill + + + align:start position:0% +ball really could roll down the hill +but it has to get out of the little + + align:start position:0% +but it has to get out of the little + + + align:start position:0% +but it has to get out of the little +hollow that it's in before it can do so + + align:start position:0% +hollow that it's in before it can do so + + + align:start position:0% +hollow that it's in before it can do so +getting out of the little hollow so the + + align:start position:0% +getting out of the little hollow so the + + + align:start position:0% +getting out of the little hollow so the +ball can roll down the hill + + align:start position:0% +ball can roll down the hill + + + align:start position:0% +ball can roll down the hill +is the activation energy of a chemical + + align:start position:0% +is the activation energy of a chemical + + + align:start position:0% +is the activation energy of a chemical +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +this can be a real barrier to getting + + align:start position:0% +this can be a real barrier to getting + + + align:start position:0% +this can be a real barrier to getting +chemical reactions to go + + align:start position:0% +chemical reactions to go + + + align:start position:0% +chemical reactions to go +and there is a whole class of substances + + align:start position:0% +and there is a whole class of substances + + + align:start position:0% +and there is a whole class of substances +that + + align:start position:0% +that + + + align:start position:0% +that +bring this activation energy down and + + align:start position:0% +bring this activation energy down and + + + align:start position:0% +bring this activation energy down and +allow reactions to proceed + + align:start position:0% +allow reactions to proceed + + + align:start position:0% +allow reactions to proceed +these are called catalysts + + align:start position:0% +these are called catalysts + + + align:start position:0% +these are called catalysts +and they are the things that will get + + align:start position:0% +and they are the things that will get + + + align:start position:0% +and they are the things that will get +your ball out of the hollow that will + + align:start position:0% +your ball out of the hollow that will + + + align:start position:0% +your ball out of the hollow that will +get you over the activation energy hump + + align:start position:0% +get you over the activation energy hump + + + align:start position:0% +get you over the activation energy hump +and allow the reaction to proceed so + + align:start position:0% +and allow the reaction to proceed so + + + align:start position:0% +and allow the reaction to proceed so +catalysts are a class of chemicals + + align:start position:0% +catalysts are a class of chemicals + + + align:start position:0% +catalysts are a class of chemicals +that decrease activation + + align:start position:0% +that decrease activation + + + align:start position:0% +that decrease activation +energy and they're found all over + + align:start position:0% +energy and they're found all over + + + align:start position:0% +energy and they're found all over +chemistry + + align:start position:0% +chemistry + + + align:start position:0% +chemistry +but in life they are defined by a + + align:start position:0% +but in life they are defined by a + + + align:start position:0% +but in life they are defined by a +particular class of biological molecules + + align:start position:0% +particular class of biological molecules + + + align:start position:0% +particular class of biological molecules +that are the enzymes enzymes + + align:start position:0% +that are the enzymes enzymes + + + align:start position:0% +that are the enzymes enzymes +are a hugely important class of + + align:start position:0% +are a hugely important class of + + + align:start position:0% +are a hugely important class of +biological molecules + + align:start position:0% +biological molecules + + + align:start position:0% +biological molecules +and enzymes are biological catalysts + + align:start position:0% +and enzymes are biological catalysts + + + align:start position:0% +and enzymes are biological catalysts +i'll write a couple more things on the + + align:start position:0% +i'll write a couple more things on the + + + align:start position:0% +i'll write a couple more things on the +board and then we'll look at a slide or + + align:start position:0% +board and then we'll look at a slide or + + + align:start position:0% +board and then we'll look at a slide or +so + + align:start position:0% +so + + + align:start position:0% +so +enzymes are very cool because they're + + align:start position:0% +enzymes are very cool because they're + + + align:start position:0% +enzymes are very cool because they're +specific + + align:start position:0% +specific + + + align:start position:0% +specific +for every reaction there are thousands + + align:start position:0% +for every reaction there are thousands + + + align:start position:0% +for every reaction there are thousands +and thousands of enzymes in our bodies + + align:start position:0% +and thousands of enzymes in our bodies + + + align:start position:0% +and thousands of enzymes in our bodies +each of them responsible for pushing a + + align:start position:0% +each of them responsible for pushing a + + + align:start position:0% +each of them responsible for pushing a +particular chemical reaction + + align:start position:0% +particular chemical reaction + + + align:start position:0% +particular chemical reaction +over the activation energy hump + + align:start position:0% + + + + align:start position:0% + +so we can write that enzymes are + + align:start position:0% +so we can write that enzymes are + + + align:start position:0% +so we can write that enzymes are +specific + + align:start position:0% +specific + + + align:start position:0% +specific +for each chemical reaction + + align:start position:0% +for each chemical reaction + + + align:start position:0% +for each chemical reaction +each metabolic process in the cell + + align:start position:0% +each metabolic process in the cell + + + align:start position:0% +each metabolic process in the cell +and key to this is that they do not + + align:start position:0% +and key to this is that they do not + + + align:start position:0% +and key to this is that they do not +change the value of delta g they rather + + align:start position:0% +change the value of delta g they rather + + + align:start position:0% +change the value of delta g they rather +speed up the rate of the reaction + + align:start position:0% +speed up the rate of the reaction + + + align:start position:0% +speed up the rate of the reaction +so they do not change delta g + + align:start position:0% +so they do not change delta g + + + align:start position:0% +so they do not change delta g +but speed up reaction rate + + align:start position:0% +but speed up reaction rate + + + align:start position:0% +but speed up reaction rate +how fast it goes the notion of enzymes + + align:start position:0% +how fast it goes the notion of enzymes + + + align:start position:0% +how fast it goes the notion of enzymes +is something that is shown on this slide + + align:start position:0% +is something that is shown on this slide + + + align:start position:0% +is something that is shown on this slide +the enzyme is a molecule and it has + + align:start position:0% +the enzyme is a molecule and it has + + + align:start position:0% +the enzyme is a molecule and it has +a particular place where the substrate + + align:start position:0% +a particular place where the substrate + + + align:start position:0% +a particular place where the substrate +or the reactants + + align:start position:0% +or the reactants + + + align:start position:0% +or the reactants +can bind this is called the active site + + align:start position:0% +can bind this is called the active site + + + align:start position:0% +can bind this is called the active site +and in the schematic the substrate + + align:start position:0% +and in the schematic the substrate + + + align:start position:0% +and in the schematic the substrate +comes and binds to the enzyme and forms + + align:start position:0% +comes and binds to the enzyme and forms + + + align:start position:0% +comes and binds to the enzyme and forms +this + + align:start position:0% +this + + + align:start position:0% +this +enzyme substrate complex and the + + align:start position:0% +enzyme substrate complex and the + + + align:start position:0% +enzyme substrate complex and the +substrate pretty much + + align:start position:0% +substrate pretty much + + + align:start position:0% +substrate pretty much +fits in a particular part of the enzyme + + align:start position:0% +fits in a particular part of the enzyme + + + align:start position:0% +fits in a particular part of the enzyme +once the substrate is inside the enzyme + + align:start position:0% +once the substrate is inside the enzyme + + + align:start position:0% +once the substrate is inside the enzyme +or bound to the enzyme then various + + align:start position:0% +or bound to the enzyme then various + + + align:start position:0% +or bound to the enzyme then various +changes happen that push the substrate + + align:start position:0% +changes happen that push the substrate + + + align:start position:0% +changes happen that push the substrate +over the activation energy barrier and + + align:start position:0% +over the activation energy barrier and + + + align:start position:0% +over the activation energy barrier and +allow the product + + align:start position:0% +allow the product + + + align:start position:0% +allow the product +to form once the product's formed + + align:start position:0% +to form once the product's formed + + + align:start position:0% +to form once the product's formed +it's released from the enzyme and the + + align:start position:0% +it's released from the enzyme and the + + + align:start position:0% +it's released from the enzyme and the +enzyme is free + + align:start position:0% +enzyme is free + + + align:start position:0% +enzyme is free +to be a catalyst again for that chemical + + align:start position:0% +to be a catalyst again for that chemical + + + align:start position:0% +to be a catalyst again for that chemical +reaction + + align:start position:0% + + + + align:start position:0% + +as we discussed chemical reactions are + + align:start position:0% +as we discussed chemical reactions are + + + align:start position:0% +as we discussed chemical reactions are +reversible and so you can see + + align:start position:0% +reversible and so you can see + + + align:start position:0% +reversible and so you can see +that there are places where the reaction + + align:start position:0% +that there are places where the reaction + + + align:start position:0% +that there are places where the reaction +could proceed backwards + + align:start position:0% +could proceed backwards + + + align:start position:0% +could proceed backwards +although it may not usually do so + + align:start position:0% + + + + align:start position:0% + +the specificity of enzymes is really + + align:start position:0% +the specificity of enzymes is really + + + align:start position:0% +the specificity of enzymes is really +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +on this slide you can see um two + + align:start position:0% +on this slide you can see um two + + + align:start position:0% +on this slide you can see um two +enzymes and these are depicted in a + + align:start position:0% +enzymes and these are depicted in a + + + align:start position:0% +enzymes and these are depicted in a +various + + align:start position:0% +various + + + align:start position:0% +various +in a specific structural way so that you + + align:start position:0% +in a specific structural way so that you + + + align:start position:0% +in a specific structural way so that you +can see how the + + align:start position:0% +can see how the + + + align:start position:0% +can see how the +protein is folded + + align:start position:0% + + + + align:start position:0% + +on the left hand side is the structure + + align:start position:0% +on the left hand side is the structure + + + align:start position:0% +on the left hand side is the structure +of an enzyme called + + align:start position:0% +of an enzyme called + + + align:start position:0% +of an enzyme called +cellulase it breaks down + + align:start position:0% +cellulase it breaks down + + + align:start position:0% +cellulase it breaks down +cellulose which is the carbohydrate + + align:start position:0% +cellulose which is the carbohydrate + + + align:start position:0% +cellulose which is the carbohydrate +of plants it's in grass it's one of the + + align:start position:0% +of plants it's in grass it's one of the + + + align:start position:0% +of plants it's in grass it's one of the +reasons + + align:start position:0% +reasons + + + align:start position:0% +reasons +that that you cannot you and i + + align:start position:0% +that that you cannot you and i + + + align:start position:0% +that that you cannot you and i +cannot eat grass okay we do not have + + align:start position:0% +cannot eat grass okay we do not have + + + align:start position:0% +cannot eat grass okay we do not have +this enzyme called cellulase + + align:start position:0% +this enzyme called cellulase + + + align:start position:0% +this enzyme called cellulase +okay some organisms do and they're able + + align:start position:0% +okay some organisms do and they're able + + + align:start position:0% +okay some organisms do and they're able +to break down grass + + align:start position:0% +to break down grass + + + align:start position:0% +to break down grass +and to use the um the sugars that come + + align:start position:0% +and to use the um the sugars that come + + + align:start position:0% +and to use the um the sugars that come +from cellulose + + align:start position:0% +from cellulose + + + align:start position:0% +from cellulose +on the right hand side is an enzyme + + align:start position:0% +on the right hand side is an enzyme + + + align:start position:0% +on the right hand side is an enzyme +called + + align:start position:0% +called + + + align:start position:0% +called +amylase amylase breaks down + + align:start position:0% +amylase amylase breaks down + + + align:start position:0% +amylase amylase breaks down +bonds in polymers + + align:start position:0% +bonds in polymers + + + align:start position:0% +bonds in polymers +of glucose that are found in starch + + align:start position:0% +of glucose that are found in starch + + + align:start position:0% +of glucose that are found in starch +you and i have this enzyme and so we can + + align:start position:0% +you and i have this enzyme and so we can + + + align:start position:0% +you and i have this enzyme and so we can +break down starch + + align:start position:0% +break down starch + + + align:start position:0% +break down starch +and use this as a source of energy + + align:start position:0% +and use this as a source of energy + + + align:start position:0% +and use this as a source of energy +these two enzymes have very similar + + align:start position:0% +these two enzymes have very similar + + + align:start position:0% +these two enzymes have very similar +specificity + + align:start position:0% +specificity + + + align:start position:0% +specificity +the cellulase breaks down these beta 1 + + align:start position:0% +the cellulase breaks down these beta 1 + + + align:start position:0% +the cellulase breaks down these beta 1 +4 bonds between glucose monomers + + align:start position:0% +4 bonds between glucose monomers + + + align:start position:0% +4 bonds between glucose monomers +in cellulose and the amylase breaks down + + align:start position:0% +in cellulose and the amylase breaks down + + + align:start position:0% +in cellulose and the amylase breaks down +a slightly different bond called an + + align:start position:0% +a slightly different bond called an + + + align:start position:0% +a slightly different bond called an +alpha 1 4 bond in starch + + align:start position:0% +alpha 1 4 bond in starch + + + align:start position:0% +alpha 1 4 bond in starch +the bonds are similar but they're + + align:start position:0% +the bonds are similar but they're + + + align:start position:0% +the bonds are similar but they're +different enough + + align:start position:0% +different enough + + + align:start position:0% +different enough +that you need separate enzymes in order + + align:start position:0% +that you need separate enzymes in order + + + align:start position:0% +that you need separate enzymes in order +to break them down + + align:start position:0% +to break them down + + + align:start position:0% +to break them down +and these enzyme differences are the + + align:start position:0% +and these enzyme differences are the + + + align:start position:0% +and these enzyme differences are the +reason + + align:start position:0% +reason + + + align:start position:0% +reason +that you can or cannot eat grass and + + align:start position:0% +that you can or cannot eat grass and + + + align:start position:0% +that you can or cannot eat grass and +they demonstrate this notion + + align:start position:0% +they demonstrate this notion + + + align:start position:0% +they demonstrate this notion +of enzyme specificity + + align:start position:0% + + + + align:start position:0% + +i want you to take a few minutes now + + align:start position:0% +i want you to take a few minutes now + + + align:start position:0% +i want you to take a few minutes now +to look at the assignment the exercises + + align:start position:0% +to look at the assignment the exercises + + + align:start position:0% +to look at the assignment the exercises +that have to do with free energy + + align:start position:0% +that have to do with free energy + + + align:start position:0% +that have to do with free energy +and practice some of these concepts that + + align:start position:0% +and practice some of these concepts that + + + align:start position:0% +and practice some of these concepts that +we've just discussed + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/9J_VCHpvMbY.txt b/9J_VCHpvMbY.txt new file mode 100644 index 0000000000000000000000000000000000000000..c5a6cca28da7a55b1c67be5a1c5cdd8af6bd652f --- /dev/null +++ b/9J_VCHpvMbY.txt @@ -0,0 +1,723 @@ +align:start position:0% + +hi welcome back to recitation we've been + + align:start position:0% +hi welcome back to recitation we've been + + + align:start position:0% +hi welcome back to recitation we've been +talking about applications of + + align:start position:0% +talking about applications of + + + align:start position:0% +talking about applications of +integration including finding the areas + + align:start position:0% +integration including finding the areas + + + align:start position:0% +integration including finding the areas +between curves so I have here a nice + + align:start position:0% +between curves so I have here a nice + + + align:start position:0% +between curves so I have here a nice +little region that I like I think it's + + align:start position:0% +little region that I like I think it's + + + align:start position:0% +little region that I like I think it's +kind of cute so so it's the region + + align:start position:0% +kind of cute so so it's the region + + + align:start position:0% +kind of cute so so it's the region +between yal sinx and yal cosine X and + + align:start position:0% +between yal sinx and yal cosine X and + + + align:start position:0% +between yal sinx and yal cosine X and +and you know those those two curves + + align:start position:0% +and you know those those two curves + + + align:start position:0% +and you know those those two curves +cross each other over and over again + + align:start position:0% +cross each other over and over again + + + align:start position:0% +cross each other over and over again +they they repr each so just I'm just + + align:start position:0% +they they repr each so just I'm just + + + align:start position:0% +they they repr each so just I'm just +interested in the in the region between + + align:start position:0% +interested in the in the region between + + + align:start position:0% +interested in the in the region between +the the two consecutive points where + + align:start position:0% +the the two consecutive points where + + + align:start position:0% +the the two consecutive points where +they cross so so here you know so at pi + + align:start position:0% +they cross so so here you know so at pi + + + align:start position:0% +they cross so so here you know so at pi +over 4 we have Sin xals Sin pi over4 + + align:start position:0% +over 4 we have Sin xals Sin pi over4 + + + align:start position:0% +over 4 we have Sin xals Sin pi over4 +equals cosine pi over 4 and and at 5 Pi + + align:start position:0% +equals cosine pi over 4 and and at 5 Pi + + + align:start position:0% +equals cosine pi over 4 and and at 5 Pi +over4 they're also equal again down in + + align:start position:0% +over4 they're also equal again down in + + + align:start position:0% +over4 they're also equal again down in +the third quadrant there um so so the + + align:start position:0% +the third quadrant there um so so the + + + align:start position:0% +the third quadrant there um so so the +question is to to compute the the area + + align:start position:0% +question is to to compute the the area + + + align:start position:0% +question is to to compute the the area +of of this region that they that they + + align:start position:0% +of of this region that they that they + + + align:start position:0% +of of this region that they that they +bound between those two points so why + + align:start position:0% +bound between those two points so why + + + align:start position:0% +bound between those two points so why +don't you take a couple minutes work + + align:start position:0% +don't you take a couple minutes work + + + align:start position:0% +don't you take a couple minutes work +through that come back and we can work + + align:start position:0% +through that come back and we can work + + + align:start position:0% +through that come back and we can work +through it + + align:start position:0% +through it + + + align:start position:0% +through it +together + + align:start position:0% + + + + align:start position:0% + +all right welcome back so from this + + align:start position:0% +all right welcome back so from this + + + align:start position:0% +all right welcome back so from this +picture it's it's pretty easy to see + + align:start position:0% +picture it's it's pretty easy to see + + + align:start position:0% +picture it's it's pretty easy to see +what the region of integration is I mean + + align:start position:0% +what the region of integration is I mean + + + align:start position:0% +what the region of integration is I mean +what the bounds on X will be as we said + + align:start position:0% +what the bounds on X will be as we said + + + align:start position:0% +what the bounds on X will be as we said +X has to go the the left I mean you + + align:start position:0% +X has to go the the left I mean you + + + align:start position:0% +X has to go the the left I mean you +could let me sorry let me start over you + + align:start position:0% +could let me sorry let me start over you + + + align:start position:0% +could let me sorry let me start over you +could do any two consecutive + + align:start position:0% +could do any two consecutive + + + align:start position:0% +could do any two consecutive +intersection points you want right the + + align:start position:0% +intersection points you want right the + + + align:start position:0% +intersection points you want right the +area is the same in any case because of + + align:start position:0% +area is the same in any case because of + + + align:start position:0% +area is the same in any case because of +the symmetry of these two functions so + + align:start position:0% +the symmetry of these two functions so + + + align:start position:0% +the symmetry of these two functions so +okay but but the first two that are easy + + align:start position:0% +okay but but the first two that are easy + + + align:start position:0% +okay but but the first two that are easy +easiest for me to find are are this pi + + align:start position:0% +easiest for me to find are are this pi + + + align:start position:0% +easiest for me to find are are this pi +over4 and this 5 Pi over4 so I'm going + + align:start position:0% +over4 and this 5 Pi over4 so I'm going + + + align:start position:0% +over4 and this 5 Pi over4 so I'm going +to do those two if you wanted you could + + align:start position:0% +to do those two if you wanted you could + + + align:start position:0% +to do those two if you wanted you could +have done it with with you know a + + align:start position:0% +have done it with with you know a + + + align:start position:0% +have done it with with you know a +different pair of consecutive points um + + align:start position:0% +different pair of consecutive points um + + + align:start position:0% +different pair of consecutive points um +but once we've agreed that that sort of + + align:start position:0% +but once we've agreed that that sort of + + + align:start position:0% +but once we've agreed that that sort of +these first two are the ones I'm going + + align:start position:0% +these first two are the ones I'm going + + + align:start position:0% +these first two are the ones I'm going +to do okay then it's easy I know that + + align:start position:0% +to do okay then it's easy I know that + + + align:start position:0% +to do okay then it's easy I know that +they're pi over4 and 5 Pi over4 so + + align:start position:0% +they're pi over4 and 5 Pi over4 so + + + align:start position:0% +they're pi over4 and 5 Pi over4 so +that's the the interval over which I'm + + align:start position:0% +that's the the interval over which I'm + + + align:start position:0% +that's the the interval over which I'm +going to be integrating and then what I + + align:start position:0% +going to be integrating and then what I + + + align:start position:0% +going to be integrating and then what I +want to do is just view this region as + + align:start position:0% +want to do is just view this region as + + + align:start position:0% +want to do is just view this region as +cut into a lot of little rectangles and + + align:start position:0% +cut into a lot of little rectangles and + + + align:start position:0% +cut into a lot of little rectangles and +I want to integrate the the height the + + align:start position:0% +I want to integrate the the height the + + + align:start position:0% +I want to integrate the the height the +of that of those rectangles in order to + + align:start position:0% +of that of those rectangles in order to + + + align:start position:0% +of that of those rectangles in order to +get the area of the whole region um so + + align:start position:0% +get the area of the whole region um so + + + align:start position:0% +get the area of the whole region um so +in this case the upper curve is yal sinx + + align:start position:0% +in this case the upper curve is yal sinx + + + align:start position:0% +in this case the upper curve is yal sinx +and the lower curve is yal cosine of x + + align:start position:0% +and the lower curve is yal cosine of x + + + align:start position:0% +and the lower curve is yal cosine of x +so the height of a little you know if I + + align:start position:0% +so the height of a little you know if I + + + align:start position:0% +so the height of a little you know if I +draw in a little rectangle + + align:start position:0% + + + + align:start position:0% + +here the height of that rectangle is + + align:start position:0% +here the height of that rectangle is + + + align:start position:0% +here the height of that rectangle is +going to be sinx minus cosine X its + + align:start position:0% +going to be sinx minus cosine X its + + + align:start position:0% +going to be sinx minus cosine X its +width is DX and then I add them all up + + align:start position:0% +width is DX and then I add them all up + + + align:start position:0% +width is DX and then I add them all up +by integrating so the + + align:start position:0% +by integrating so the + + + align:start position:0% +by integrating so the +area is just the + + align:start position:0% +area is just the + + + align:start position:0% +area is just the +integral from pi over + + align:start position:0% +integral from pi over + + + align:start position:0% +integral from pi over +4 to 5 piun over4 + + align:start position:0% +4 to 5 piun over4 + + + align:start position:0% +4 to 5 piun over4 +of + + align:start position:0% +of + + + align:start position:0% +of +sinx minus cosine X DX top minus bottom + + align:start position:0% +sinx minus cosine X DX top minus bottom + + + align:start position:0% +sinx minus cosine X DX top minus bottom +to get the height if you did it + + align:start position:0% +to get the height if you did it + + + align:start position:0% +to get the height if you did it +backwards if you wrote cosine minus s + + align:start position:0% +backwards if you wrote cosine minus s + + + align:start position:0% +backwards if you wrote cosine minus s +what you would get is exactly the + + align:start position:0% +what you would get is exactly the + + + align:start position:0% +what you would get is exactly the +negative of the area so it's all right + + align:start position:0% +negative of the area so it's all right + + + align:start position:0% +negative of the area so it's all right +from pi over 4 to 5 pi over 4 okay so + + align:start position:0% +from pi over 4 to 5 pi over 4 okay so + + + align:start position:0% +from pi over 4 to 5 pi over 4 okay so +now we just have to integrate this right + + align:start position:0% +now we just have to integrate this right + + + align:start position:0% +now we just have to integrate this right +so integral of sign the function whose + + align:start position:0% +so integral of sign the function whose + + + align:start position:0% +so integral of sign the function whose +derivative is s is + + align:start position:0% +derivative is s is + + + align:start position:0% +derivative is s is +minus cosine X and the function whose + + align:start position:0% +minus cosine X and the function whose + + + align:start position:0% +minus cosine X and the function whose +derivative is cosine is s so it's + + align:start position:0% +derivative is cosine is s so it's + + + align:start position:0% +derivative is cosine is s so it's +minus sin x + + align:start position:0% +minus sin x + + + align:start position:0% +minus sin x +between pi over + + align:start position:0% + + + + align:start position:0% + +4 5 pi over 4 and okay so so now we just + + align:start position:0% +4 5 pi over 4 and okay so so now we just + + + align:start position:0% +4 5 pi over 4 and okay so so now we just +have to plug in the values so this is + + align:start position:0% +have to plug in the values so this is + + + align:start position:0% +have to plug in the values so this is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +minus + + align:start position:0% +minus + + + align:start position:0% +minus +cosine 5i + + align:start position:0% +cosine 5i + + + align:start position:0% +cosine 5i +4us s + + align:start position:0% +4us s + + + align:start position:0% +4us s +5 Pi + + align:start position:0% +5 Pi + + + align:start position:0% +5 Pi +4 minus + + align:start position:0% +4 minus + + + align:start position:0% +4 minus +minus cosine pi over + + align:start position:0% +minus cosine pi over + + + align:start position:0% +minus cosine pi over +4 minus + + align:start position:0% +4 minus + + + align:start position:0% +4 minus +s pi over 4 and I'm sure you can work + + align:start position:0% +s pi over 4 and I'm sure you can work + + + align:start position:0% +s pi over 4 and I'm sure you can work +out for yourself that this is equal + + align:start position:0% + + + + align:start position:0% + +to two * the squ of two if I haven't + + align:start position:0% +to two * the squ of two if I haven't + + + align:start position:0% +to two * the squ of two if I haven't +botched anything + + align:start position:0% +botched anything + + + align:start position:0% +botched anything +terribly so I'll end there \ No newline at end of file diff --git a/9QwiP6glJfw.txt b/9QwiP6glJfw.txt new file mode 100644 index 0000000000000000000000000000000000000000..196a15f28f1720b97cd76c0773262d0f3ff85275 --- /dev/null +++ b/9QwiP6glJfw.txt @@ -0,0 +1,427 @@ +align:start position:0% + +okay this is where we were teaching the + + align:start position:0% +okay this is where we were teaching the + + + align:start position:0% +okay this is where we were teaching the +class this is the new ESG kitchen um + + align:start position:0% +class this is the new ESG kitchen um + + + align:start position:0% +class this is the new ESG kitchen um +well we don't use it only for this class + + align:start position:0% +well we don't use it only for this class + + + align:start position:0% +well we don't use it only for this class +it's a community uh kitchen so all the + + align:start position:0% +it's a community uh kitchen so all the + + + align:start position:0% +it's a community uh kitchen so all the +students in the community can use it and + + align:start position:0% +students in the community can use it and + + + align:start position:0% +students in the community can use it and +on Friday we have a community lunch uh + + align:start position:0% +on Friday we have a community lunch uh + + + align:start position:0% +on Friday we have a community lunch uh +so one or two students or uh staff + + align:start position:0% +so one or two students or uh staff + + + align:start position:0% +so one or two students or uh staff +members cook for uh everybody else and + + align:start position:0% +members cook for uh everybody else and + + + align:start position:0% +members cook for uh everybody else and +and this is where where we usually eat + + align:start position:0% +and this is where where we usually eat + + + align:start position:0% +and this is where where we usually eat +all together but for the speak Italian + + align:start position:0% +all together but for the speak Italian + + + align:start position:0% +all together but for the speak Italian +with your mouthful seminar we were using + + align:start position:0% +with your mouthful seminar we were using + + + align:start position:0% +with your mouthful seminar we were using +this board whenever we needed to discuss + + align:start position:0% +this board whenever we needed to discuss + + + align:start position:0% +this board whenever we needed to discuss +some grammar some vocabulary right now + + align:start position:0% +some grammar some vocabulary right now + + + align:start position:0% +some grammar some vocabulary right now +there is some Physics problem that's + + align:start position:0% +there is some Physics problem that's + + + align:start position:0% +there is some Physics problem that's +good because they're my + + align:start position:0% +good because they're my + + + align:start position:0% +good because they're my +students so I know that they have solved + + align:start position:0% +students so I know that they have solved + + + align:start position:0% +students so I know that they have solved +the problem set um and I also had a + + align:start position:0% +the problem set um and I also had a + + + align:start position:0% +the problem set um and I also had a +portable + + align:start position:0% +portable + + + align:start position:0% +portable +whiteboard in case um we needed to have + + align:start position:0% +whiteboard in case um we needed to have + + + align:start position:0% +whiteboard in case um we needed to have +uh to to visualize some of the uh + + align:start position:0% +uh to to visualize some of the uh + + + align:start position:0% +uh to to visualize some of the uh +grammar for example while we were + + align:start position:0% +grammar for example while we were + + + align:start position:0% +grammar for example while we were +cooking so this is the common Lounge um + + align:start position:0% +cooking so this is the common Lounge um + + + align:start position:0% +cooking so this is the common Lounge um +it's well right now there is nobody + + align:start position:0% +it's well right now there is nobody + + + align:start position:0% +it's well right now there is nobody +around because uh it's a holiday but uh + + align:start position:0% +around because uh it's a holiday but uh + + + align:start position:0% +around because uh it's a holiday but uh +usually there are students at every time + + align:start position:0% +usually there are students at every time + + + align:start position:0% +usually there are students at every time +of the day or night it's open + + align:start position:0% +of the day or night it's open + + + align:start position:0% +of the day or night it's open +24/7 and the students come here to work + + align:start position:0% +24/7 and the students come here to work + + + align:start position:0% +24/7 and the students come here to work +on problem sets together or just + + align:start position:0% +on problem sets together or just + + + align:start position:0% +on problem sets together or just +sometimes socialize we have a piano we + + align:start position:0% +sometimes socialize we have a piano we + + + align:start position:0% +sometimes socialize we have a piano we +might have somebody play playing the + + align:start position:0% +might have somebody play playing the + + + align:start position:0% +might have somebody play playing the +piano while the others are solving + + align:start position:0% +piano while the others are solving + + + align:start position:0% +piano while the others are solving +problems at the + + align:start position:0% +problems at the + + + align:start position:0% +problems at the +board and then we have our classrooms on + + align:start position:0% +board and then we have our classrooms on + + + align:start position:0% +board and then we have our classrooms on +both sides of the hallway I can show you + + align:start position:0% +both sides of the hallway I can show you + + + align:start position:0% +both sides of the hallway I can show you +yeah so this is the classroom where I + + align:start position:0% +yeah so this is the classroom where I + + + align:start position:0% +yeah so this is the classroom where I +usually teach physics and as you can see + + align:start position:0% +usually teach physics and as you can see + + + align:start position:0% +usually teach physics and as you can see +it's pretty small we have about um 10 12 + + align:start position:0% +it's pretty small we have about um 10 12 + + + align:start position:0% +it's pretty small we have about um 10 12 +seats it's very different from um the + + align:start position:0% +seats it's very different from um the + + + align:start position:0% +seats it's very different from um the +classrooms in the regular curriculum + + align:start position:0% +classrooms in the regular curriculum + + + align:start position:0% +classrooms in the regular curriculum +where you might take physics but with + + align:start position:0% +where you might take physics but with + + + align:start position:0% +where you might take physics but with +another few hundred students um here + + align:start position:0% +another few hundred students um here + + + align:start position:0% +another few hundred students um here +everybody knows each other by name so + + align:start position:0% +everybody knows each other by name so + + + align:start position:0% +everybody knows each other by name so +they can really work together and um + + align:start position:0% +they can really work together and um + + + align:start position:0% +they can really work together and um +well I use the board so part of my + + align:start position:0% +well I use the board so part of my + + + align:start position:0% +well I use the board so part of my +classes are still lecture style but then + + align:start position:0% +classes are still lecture style but then + + + align:start position:0% +classes are still lecture style but then +we work in groups as you can see from + + align:start position:0% +we work in groups as you can see from + + + align:start position:0% +we work in groups as you can see from +the structure of the table we have + + align:start position:0% +the structure of the table we have + + + align:start position:0% +the structure of the table we have +chairs all around um so apart from the + + align:start position:0% +chairs all around um so apart from the + + + align:start position:0% +chairs all around um so apart from the +main board I also use portable + + align:start position:0% +main board I also use portable + + + align:start position:0% +main board I also use portable +whiteboards um and the idea is that + + align:start position:0% +whiteboards um and the idea is that + + + align:start position:0% +whiteboards um and the idea is that +during the class we can split and um + + align:start position:0% +during the class we can split and um + + + align:start position:0% +during the class we can split and um +solve problems in groups or of two or + + align:start position:0% +solve problems in groups or of two or + + + align:start position:0% +solve problems in groups or of two or +three people which makes it much more + + align:start position:0% +three people which makes it much more + + + align:start position:0% +three people which makes it much more +Interactive \ No newline at end of file diff --git a/9T9EMayW-GA.txt b/9T9EMayW-GA.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c956211033969b957a74ca8e4659f5f2c436b96 --- /dev/null +++ b/9T9EMayW-GA.txt @@ -0,0 +1,14952 @@ +align:start position:0% + +we have some administrative things today + + align:start position:0% +we have some administrative things today + + + align:start position:0% +we have some administrative things today +there are uh first of all there are two + + align:start position:0% +there are uh first of all there are two + + + align:start position:0% +there are uh first of all there are two +handouts 34 and 35 we've got the lecture + + align:start position:0% +handouts 34 and 35 we've got the lecture + + + align:start position:0% +handouts 34 and 35 we've got the lecture +notes and I'm handing out the solutions + + align:start position:0% +notes and I'm handing out the solutions + + + align:start position:0% +notes and I'm handing out the solutions +to homework number four and homework + + align:start position:0% +to homework number four and homework + + + align:start position:0% +to homework number four and homework +number four is going back so you can + + align:start position:0% +number four is going back so you can + + + align:start position:0% +number four is going back so you can +pick up homework number four it's in the + + align:start position:0% +pick up homework number four it's in the + + + align:start position:0% +pick up homework number four it's in the +orange folder in the back there and uh + + align:start position:0% +orange folder in the back there and uh + + + align:start position:0% +orange folder in the back there and uh +some reminders or announcements um these + + align:start position:0% +some reminders or announcements um these + + + align:start position:0% +some reminders or announcements um these +will appear on the website today so uh + + align:start position:0% +will appear on the website today so uh + + + align:start position:0% +will appear on the website today so uh +but just to remind you your uh written + + align:start position:0% +but just to remind you your uh written + + + align:start position:0% +but just to remind you your uh written +reports are are due here on uh Thursday + + align:start position:0% +reports are are due here on uh Thursday + + + align:start position:0% +reports are are due here on uh Thursday +December 9th in + + align:start position:0% +December 9th in + + + align:start position:0% +December 9th in +class um I have come up with a a + + align:start position:0% +class um I have come up with a a + + + align:start position:0% +class um I have come up with a a +schedule for the presenters for the + + align:start position:0% +schedule for the presenters for the + + + align:start position:0% +schedule for the presenters for the +people doing oral presentations that's + + align:start position:0% +people doing oral presentations that's + + + align:start position:0% +people doing oral presentations that's +shown here uh we have two uh lecture + + align:start position:0% +shown here uh we have two uh lecture + + + align:start position:0% +shown here uh we have two uh lecture +periods that we're dedicated to oral + + align:start position:0% +periods that we're dedicated to oral + + + align:start position:0% +periods that we're dedicated to oral +presentations the last two lectures of + + align:start position:0% +presentations the last two lectures of + + + align:start position:0% +presentations the last two lectures of +this term so on uh December 7th uh we + + align:start position:0% +this term so on uh December 7th uh we + + + align:start position:0% +this term so on uh December 7th uh we +have uh four speakers and these are the + + align:start position:0% +have uh four speakers and these are the + + + align:start position:0% +have uh four speakers and these are the +four speakers I have chosen for December + + align:start position:0% +four speakers I have chosen for December + + + align:start position:0% +four speakers I have chosen for December +7th um and your presentation time should + + align:start position:0% +7th um and your presentation time should + + + align:start position:0% +7th um and your presentation time should +be of your actual presentation should be + + align:start position:0% +be of your actual presentation should be + + + align:start position:0% +be of your actual presentation should be +about 16 + + align:start position:0% +about 16 + + + align:start position:0% +about 16 +minutes and then beyond that we'll leave + + align:start position:0% +minutes and then beyond that we'll leave + + + align:start position:0% +minutes and then beyond that we'll leave +three minutes for questions and answers + + align:start position:0% +three minutes for questions and answers + + + align:start position:0% +three minutes for questions and answers +uh period so it's a short Q&A and that's + + align:start position:0% +uh period so it's a short Q&A and that's + + + align:start position:0% +uh period so it's a short Q&A and that's +for each talk so I'll make each talk + + align:start position:0% +for each talk so I'll make each talk + + + align:start position:0% +for each talk so I'll make each talk +about 20 minutes and we'll have four + + align:start position:0% +about 20 minutes and we'll have four + + + align:start position:0% +about 20 minutes and we'll have four +people in one period so that should work + + align:start position:0% +people in one period so that should work + + + align:start position:0% +people in one period so that should work +out fine uh and the same thing on + + align:start position:0% +out fine uh and the same thing on + + + align:start position:0% +out fine uh and the same thing on +December 9th these are the four speakers + + align:start position:0% +December 9th these are the four speakers + + + align:start position:0% +December 9th these are the four speakers +that I have chosen for December 9th um + + align:start position:0% +that I have chosen for December 9th um + + + align:start position:0% +that I have chosen for December 9th um +and uh uh pretty much approved all the + + align:start position:0% +and uh uh pretty much approved all the + + + align:start position:0% +and uh uh pretty much approved all the +the topics if you don't if you're not + + align:start position:0% +the topics if you don't if you're not + + + align:start position:0% +the topics if you don't if you're not +sure your topics are approved go on the + + align:start position:0% +sure your topics are approved go on the + + + align:start position:0% +sure your topics are approved go on the +website and I have an indication whether + + align:start position:0% +website and I have an indication whether + + + align:start position:0% +website and I have an indication whether +it's been approved or changed + + align:start position:0% +it's been approved or changed + + + align:start position:0% +it's been approved or changed +um if you need help you're going to be + + align:start position:0% +um if you need help you're going to be + + + align:start position:0% +um if you need help you're going to be +graded for those of you who are doing + + align:start position:0% +graded for those of you who are doing + + + align:start position:0% +graded for those of you who are doing +the oral presentations you're graded on + + align:start position:0% +the oral presentations you're graded on + + + align:start position:0% +the oral presentations you're graded on +two things um same as the written but a + + align:start position:0% +two things um same as the written but a + + + align:start position:0% +two things um same as the written but a +slightly different is you're graded on + + align:start position:0% +slightly different is you're graded on + + + align:start position:0% +slightly different is you're graded on +the presentation you know itself which + + align:start position:0% +the presentation you know itself which + + + align:start position:0% +the presentation you know itself which +includes your oral presentation as well + + align:start position:0% +includes your oral presentation as well + + + align:start position:0% +includes your oral presentation as well +as your slides so you need to provide + + align:start position:0% +as your slides so you need to provide + + + align:start position:0% +as your slides so you need to provide +handouts the same way that I I give out + + align:start position:0% +handouts the same way that I I give out + + + align:start position:0% +handouts the same way that I I give out +handouts to every lecture not as long + + align:start position:0% +handouts to every lecture not as long + + + align:start position:0% +handouts to every lecture not as long +because you're only speaking for 16 + + align:start position:0% +because you're only speaking for 16 + + + align:start position:0% +because you're only speaking for 16 +minutes um but if you need any help + + align:start position:0% +minutes um but if you need any help + + + align:start position:0% +minutes um but if you need any help +making Xerox copies you don't have + + align:start position:0% +making Xerox copies you don't have + + + align:start position:0% +making Xerox copies you don't have +access to a copy or you don't need to + + align:start position:0% +access to a copy or you don't need to + + + align:start position:0% +access to a copy or you don't need to +pay to make those zerox copies my + + align:start position:0% +pay to make those zerox copies my + + + align:start position:0% +pay to make those zerox copies my +assistant if you uh send her the um PDF + + align:start position:0% +assistant if you uh send her the um PDF + + + align:start position:0% +assistant if you uh send her the um PDF +F or the U PowerPoint file preferably or + + align:start position:0% +F or the U PowerPoint file preferably or + + + align:start position:0% +F or the U PowerPoint file preferably or +if you can bring her a hard copy uh of + + align:start position:0% +if you can bring her a hard copy uh of + + + align:start position:0% +if you can bring her a hard copy uh of +your presentation um she'll make the uh + + align:start position:0% +your presentation um she'll make the uh + + + align:start position:0% +your presentation um she'll make the uh +make the enough ZX copies for the rest + + align:start position:0% +make the enough ZX copies for the rest + + + align:start position:0% +make the enough ZX copies for the rest +of the class you need to give her some + + align:start position:0% +of the class you need to give her some + + + align:start position:0% +of the class you need to give her some +time though to do that so do uh make + + align:start position:0% +time though to do that so do uh make + + + align:start position:0% +time though to do that so do uh make +sure you get her that the day before so + + align:start position:0% +sure you get her that the day before so + + + align:start position:0% +sure you get her that the day before so +she is so she has time and her hours are + + align:start position:0% +she is so she has time and her hours are + + + align:start position:0% +she is so she has time and her hours are +8:00 a.m. to 6:00 p.m. uh to uh 2: p.m. + + align:start position:0% +8:00 a.m. to 6:00 p.m. uh to uh 2: p.m. + + + align:start position:0% +8:00 a.m. to 6:00 p.m. uh to uh 2: p.m. +8 8 to 2 so um make sure you get her + + align:start position:0% +8 8 to 2 so um make sure you get her + + + align:start position:0% +8 8 to 2 so um make sure you get her +that the day before if you want help + + align:start position:0% +that the day before if you want help + + + align:start position:0% +that the day before if you want help +making Xerox + + align:start position:0% +making Xerox + + + align:start position:0% +making Xerox +copies and the second component of your + + align:start position:0% +copies and the second component of your + + + align:start position:0% +copies and the second component of your +grade of course is on the technical + + align:start position:0% +grade of course is on the technical + + + align:start position:0% +grade of course is on the technical +content um so one one part of your grade + + align:start position:0% +content um so one one part of your grade + + + align:start position:0% +content um so one one part of your grade +is on the presentation and that includes + + align:start position:0% +is on the presentation and that includes + + + align:start position:0% +is on the presentation and that includes +the quality of your graphics and the + + align:start position:0% +the quality of your graphics and the + + + align:start position:0% +the quality of your graphics and the +quality of your handouts and and the the + + align:start position:0% +quality of your handouts and and the the + + + align:start position:0% +quality of your handouts and and the the +second part is on the actual technical + + align:start position:0% +second part is on the actual technical + + + align:start position:0% +second part is on the actual technical +content the depth and to see that you + + align:start position:0% +content the depth and to see that you + + + align:start position:0% +content the depth and to see that you +read adequate number of references that + + align:start position:0% +read adequate number of references that + + + align:start position:0% +read adequate number of references that +you understand the material and that you + + align:start position:0% +you understand the material and that you + + + align:start position:0% +you understand the material and that you +can present it same thing for written + + align:start position:0% +can present it same thing for written + + + align:start position:0% +can present it same thing for written +reports the only difference is you won't + + align:start position:0% +reports the only difference is you won't + + + align:start position:0% +reports the only difference is you won't +be gred on your speaking because you + + align:start position:0% +be gred on your speaking because you + + + align:start position:0% +be gred on your speaking because you +won't be speaking but for the written + + align:start position:0% +won't be speaking but for the written + + + align:start position:0% +won't be speaking but for the written +report you'll be graded both on + + align:start position:0% +report you'll be graded both on + + + align:start position:0% +report you'll be graded both on +technical content as well as on the + + align:start position:0% +technical content as well as on the + + + align:start position:0% +technical content as well as on the +presentation how how nicely did you lay + + align:start position:0% +presentation how how nicely did you lay + + + align:start position:0% +presentation how how nicely did you lay +out the report how well is it sectioned + + align:start position:0% +out the report how well is it sectioned + + + align:start position:0% +out the report how well is it sectioned +um are the references clear and easy to + + align:start position:0% +um are the references clear and easy to + + + align:start position:0% +um are the references clear and easy to +read do you have good good graphs or are + + align:start position:0% +read do you have good good graphs or are + + + align:start position:0% +read do you have good good graphs or are +the graphs impossible to read things + + align:start position:0% +the graphs impossible to read things + + + align:start position:0% +the graphs impossible to read things +like that so both aspects uh will be + + align:start position:0% +like that so both aspects uh will be + + + align:start position:0% +like that so both aspects uh will be +part of it and all this this information + + align:start position:0% +part of it and all this this information + + + align:start position:0% +part of it and all this this information +will be posted on the web but this gives + + align:start position:0% +will be posted on the web but this gives + + + align:start position:0% +will be posted on the web but this gives +you an idea of when you need to prepare + + align:start position:0% +you an idea of when you need to prepare + + + align:start position:0% +you an idea of when you need to prepare +yourself um so here this is where we are + + align:start position:0% +yourself um so here this is where we are + + + align:start position:0% +yourself um so here this is where we are +right now um on November 23rd this is + + align:start position:0% +right now um on November 23rd this is + + + align:start position:0% +right now um on November 23rd this is +the the Thanksgiving holidays coming up + + align:start position:0% +the the Thanksgiving holidays coming up + + + align:start position:0% +the the Thanksgiving holidays coming up +on Thursday won't have a class Thursday + + align:start position:0% +on Thursday won't have a class Thursday + + + align:start position:0% +on Thursday won't have a class Thursday +today we're finishing up chapter 10 on + + align:start position:0% +today we're finishing up chapter 10 on + + + align:start position:0% +today we're finishing up chapter 10 on +etching um and then we'll move on we + + align:start position:0% +etching um and then we'll move on we + + + align:start position:0% +etching um and then we'll move on we +have two more formal lectures that I'll + + align:start position:0% +have two more formal lectures that I'll + + + align:start position:0% +have two more formal lectures that I'll +be giving uh there'll be one on suicides + + align:start position:0% +be giving uh there'll be one on suicides + + + align:start position:0% +be giving uh there'll be one on suicides +and contacts and novel gate materials + + align:start position:0% +and contacts and novel gate materials + + + align:start position:0% +and contacts and novel gate materials +and then they'll uh on growth and + + align:start position:0% +and then they'll uh on growth and + + + align:start position:0% +and then they'll uh on growth and +processing of strain silicon and silicon + + align:start position:0% +processing of strain silicon and silicon + + + align:start position:0% +processing of strain silicon and silicon +geranium on December 2nd and then you + + align:start position:0% +geranium on December 2nd and then you + + + align:start position:0% +geranium on December 2nd and then you +you folks will start speaking on the 7th + + align:start position:0% +you folks will start speaking on the 7th + + + align:start position:0% +you folks will start speaking on the 7th +uh and and finish up on the 9th and your + + align:start position:0% +uh and and finish up on the 9th and your + + + align:start position:0% +uh and and finish up on the 9th and your +written reports again are due in class + + align:start position:0% +written reports again are due in class + + + align:start position:0% +written reports again are due in class +on that final Thursday December + + align:start position:0% +on that final Thursday December + + + align:start position:0% +on that final Thursday December +9th anybody have any questions or + + align:start position:0% +9th anybody have any questions or + + + align:start position:0% +9th anybody have any questions or +anything about the uh the final report + + align:start position:0% +anything about the uh the final report + + + align:start position:0% +anything about the uh the final report +or the + + align:start position:0% +or the + + + align:start position:0% +or the +schedule send me an email if you have + + align:start position:0% +schedule send me an email if you have + + + align:start position:0% +schedule send me an email if you have +any any questions about + + align:start position:0% +any any questions about + + + align:start position:0% +any any questions about +it okay so let's go on to today's uh + + align:start position:0% +it okay so let's go on to today's uh + + + align:start position:0% +it okay so let's go on to today's uh +today's + + align:start position:0% +today's + + + align:start position:0% +today's +notes and uh we're um each time each + + align:start position:0% +notes and uh we're um each time each + + + align:start position:0% +notes and uh we're um each time each +chapter now you notice we're going + + align:start position:0% +chapter now you notice we're going + + + align:start position:0% +chapter now you notice we're going +through a little more rapidly as we + + align:start position:0% +through a little more rapidly as we + + + align:start position:0% +through a little more rapidly as we +finish up this will uh be the last + + align:start position:0% +finish up this will uh be the last + + + align:start position:0% +finish up this will uh be the last +formal chapter of reading that you'll + + align:start position:0% +formal chapter of reading that you'll + + + align:start position:0% +formal chapter of reading that you'll +have in this class there'll be a little + + align:start position:0% +have in this class there'll be a little + + + align:start position:0% +have in this class there'll be a little +bit U on pilicides you'll have to read + + align:start position:0% +bit U on pilicides you'll have to read + + + align:start position:0% +bit U on pilicides you'll have to read +and then the last uh lecture I uh + + align:start position:0% +and then the last uh lecture I uh + + + align:start position:0% +and then the last uh lecture I uh +there's nothing written up on it so you + + align:start position:0% +there's nothing written up on it so you + + + align:start position:0% +there's nothing written up on it so you +just come to lecture so hopefully you're + + align:start position:0% +just come to lecture so hopefully you're + + + align:start position:0% +just come to lecture so hopefully you're +finishing up reading chapter uh 10 on on + + align:start position:0% +finishing up reading chapter uh 10 on on + + + align:start position:0% +finishing up reading chapter uh 10 on on +etching um what I'm showing here on the + + align:start position:0% +etching um what I'm showing here on the + + + align:start position:0% +etching um what I'm showing here on the +first slide of handout number 34 is kind + + align:start position:0% +first slide of handout number 34 is kind + + + align:start position:0% +first slide of handout number 34 is kind +of a summary of what we talked about + + align:start position:0% +of a summary of what we talked about + + + align:start position:0% +of a summary of what we talked about +last time as far as plasma etching and + + align:start position:0% +last time as far as plasma etching and + + + align:start position:0% +last time as far as plasma etching and +the various mechanisms + + align:start position:0% +the various mechanisms + + + align:start position:0% +the various mechanisms +um there are certain characteristics + + align:start position:0% +um there are certain characteristics + + + align:start position:0% +um there are certain characteristics +which we said were important uh for + + align:start position:0% +which we said were important uh for + + + align:start position:0% +which we said were important uh for +example uh the pressure of the chamber + + align:start position:0% +example uh the pressure of the chamber + + + align:start position:0% +example uh the pressure of the chamber +in which you're etching uh the energy of + + align:start position:0% +in which you're etching uh the energy of + + + align:start position:0% +in which you're etching uh the energy of +the species um and these end up + + align:start position:0% +the species um and these end up + + + align:start position:0% +the species um and these end up +affecting things like selectivity and + + align:start position:0% +affecting things like selectivity and + + + align:start position:0% +affecting things like selectivity and +isotropy uh at the top of the list of + + align:start position:0% +isotropy uh at the top of the list of + + + align:start position:0% +isotropy uh at the top of the list of +the type of etching are the most + + align:start position:0% +the type of etching are the most + + + align:start position:0% +the type of etching are the most +physical etching processes here like + + align:start position:0% +physical etching processes here like + + + align:start position:0% +physical etching processes here like +sputter etching or ion beam Milling it's + + align:start position:0% +sputter etching or ion beam Milling it's + + + align:start position:0% +sputter etching or ion beam Milling it's +pretty much purely physical there's not + + align:start position:0% +pretty much purely physical there's not + + + align:start position:0% +pretty much purely physical there's not +a lot of chemical reactions going on if + + align:start position:0% +a lot of chemical reactions going on if + + + align:start position:0% +a lot of chemical reactions going on if +you go to the very bottom type of + + align:start position:0% +you go to the very bottom type of + + + align:start position:0% +you go to the very bottom type of +etching which is wet chemical etching is + + align:start position:0% +etching which is wet chemical etching is + + + align:start position:0% +etching which is wet chemical etching is +entirely wet there is no physical + + align:start position:0% +entirely wet there is no physical + + + align:start position:0% +entirely wet there is no physical +bombardment and everything in between + + align:start position:0% +bombardment and everything in between + + + align:start position:0% +bombardment and everything in between +has a has a certain component of both + + align:start position:0% +has a has a certain component of both + + + align:start position:0% +has a has a certain component of both +chemical processes and physical uh + + align:start position:0% +chemical processes and physical uh + + + align:start position:0% +chemical processes and physical uh +processes going + + align:start position:0% +processes going + + + align:start position:0% +processes going +on and these arrows point to the + + align:start position:0% +on and these arrows point to the + + + align:start position:0% +on and these arrows point to the +direction in which the uh the quantity + + align:start position:0% +direction in which the uh the quantity + + + align:start position:0% +direction in which the uh the quantity +increases so anisotropy which is so if + + align:start position:0% +increases so anisotropy which is so if + + + align:start position:0% +increases so anisotropy which is so if +the edge to be more vertical than it is + + align:start position:0% +the edge to be more vertical than it is + + + align:start position:0% +the edge to be more vertical than it is +horizontal increases as you go from wet + + align:start position:0% +horizontal increases as you go from wet + + + align:start position:0% +horizontal increases as you go from wet +chemical which is very isotropic all if + + align:start position:0% +chemical which is very isotropic all if + + + align:start position:0% +chemical which is very isotropic all if +you go to splutter etching it's very + + align:start position:0% +you go to splutter etching it's very + + + align:start position:0% +you go to splutter etching it's very +anisotropic so anisotropy increases in + + align:start position:0% +anisotropic so anisotropy increases in + + + align:start position:0% +anisotropic so anisotropy increases in +this Direction selectivity is very poor + + align:start position:0% +this Direction selectivity is very poor + + + align:start position:0% +this Direction selectivity is very poor +or very low for sputter etching you can + + align:start position:0% +or very low for sputter etching you can + + + align:start position:0% +or very low for sputter etching you can +you can sputter everything anything and + + align:start position:0% +you can sputter everything anything and + + + align:start position:0% +you can sputter everything anything and +The Sputter rates are are not very + + align:start position:0% +The Sputter rates are are not very + + + align:start position:0% +The Sputter rates are are not very +different among the elements selectivity + + align:start position:0% +different among the elements selectivity + + + align:start position:0% +different among the elements selectivity +increas is going down so reactive ion + + align:start position:0% +increas is going down so reactive ion + + + align:start position:0% +increas is going down so reactive ion +etching is less selective plasma etching + + align:start position:0% +etching is less selective plasma etching + + + align:start position:0% +etching is less selective plasma etching +is more selective and what chemical + + align:start position:0% +is more selective and what chemical + + + align:start position:0% +is more selective and what chemical +etching tends to be the most selective + + align:start position:0% +etching tends to be the most selective + + + align:start position:0% +etching tends to be the most selective +selectivity increase in this direction + + align:start position:0% +selectivity increase in this direction + + + align:start position:0% +selectivity increase in this direction +in general the energy of the process + + align:start position:0% +in general the energy of the process + + + align:start position:0% +in general the energy of the process +increases going from the bottom to the + + align:start position:0% +increases going from the bottom to the + + + align:start position:0% +increases going from the bottom to the +top so there's more energetics involved + + align:start position:0% +top so there's more energetics involved + + + align:start position:0% +top so there's more energetics involved +in sputter etching uh the particles can + + align:start position:0% +in sputter etching uh the particles can + + + align:start position:0% +in sputter etching uh the particles can +come down with hundreds of electron + + align:start position:0% +come down with hundreds of electron + + + align:start position:0% +come down with hundreds of electron +volts and knock off um knockoff atoms on + + align:start position:0% +volts and knock off um knockoff atoms on + + + align:start position:0% +volts and knock off um knockoff atoms on +the surface so these these processes + + align:start position:0% +the surface so these these processes + + + align:start position:0% +the surface so these these processes +tend to be more + + align:start position:0% +tend to be more + + + align:start position:0% +tend to be more +energetic and the pressure of the system + + align:start position:0% +energetic and the pressure of the system + + + align:start position:0% +energetic and the pressure of the system +um here uh is is tends to be uh lowest + + align:start position:0% +um here uh is is tends to be uh lowest + + + align:start position:0% +um here uh is is tends to be uh lowest +here and then sort of increasing as you + + align:start position:0% +here and then sort of increasing as you + + + align:start position:0% +here and then sort of increasing as you +go uh from here this type of sputter + + align:start position:0% +go uh from here this type of sputter + + + align:start position:0% +go uh from here this type of sputter +etching to pla to uh say plasma + + align:start position:0% +etching to pla to uh say plasma + + + align:start position:0% +etching to pla to uh say plasma +etching so that's just what we talked + + align:start position:0% +etching so that's just what we talked + + + align:start position:0% +etching so that's just what we talked +about last time by way of mechanisms + + align:start position:0% +about last time by way of mechanisms + + + align:start position:0% +about last time by way of mechanisms +today I wanted to give some specific + + align:start position:0% +today I wanted to give some specific + + + align:start position:0% +today I wanted to give some specific +examples and I want to emphasize gate + + align:start position:0% +examples and I want to emphasize gate + + + align:start position:0% +examples and I want to emphasize gate +etching issues and I'll talk a little + + align:start position:0% +etching issues and I'll talk a little + + + align:start position:0% +etching issues and I'll talk a little +bit about uh modeling the the uh + + align:start position:0% +bit about uh modeling the the uh + + + align:start position:0% +bit about uh modeling the the uh +mechanics of how people model etge + + align:start position:0% +mechanics of how people model etge + + + align:start position:0% +mechanics of how people model etge +processes the uh on slide two this is is + + align:start position:0% +processes the uh on slide two this is is + + + align:start position:0% +processes the uh on slide two this is is +a chart or it's half of the chart that I + + align:start position:0% +a chart or it's half of the chart that I + + + align:start position:0% +a chart or it's half of the chart that I +took directly from chapter 10 in your + + align:start position:0% +took directly from chapter 10 in your + + + align:start position:0% +took directly from chapter 10 in your +text and what it shows is um a series of + + align:start position:0% +text and what it shows is um a series of + + + align:start position:0% +text and what it shows is um a series of +common materials and some typical + + align:start position:0% +common materials and some typical + + + align:start position:0% +common materials and some typical +etchants um that are used and then some + + align:start position:0% +etchants um that are used and then some + + + align:start position:0% +etchants um that are used and then some +comments about each of these um etchants + + align:start position:0% +comments about each of these um etchants + + + align:start position:0% +comments about each of these um etchants +for example uh a very common way of + + align:start position:0% +for example uh a very common way of + + + align:start position:0% +for example uh a very common way of +etching polyic + + align:start position:0% +etching polyic + + + align:start position:0% +etching polyic +uh in a generic way is to use sf6 or + + align:start position:0% +uh in a generic way is to use sf6 or + + + align:start position:0% +uh in a generic way is to use sf6 or +cf4 uh what are the characteristics of + + align:start position:0% +cf4 uh what are the characteristics of + + + align:start position:0% +cf4 uh what are the characteristics of +that type of edch well it tends to be + + align:start position:0% +that type of edch well it tends to be + + + align:start position:0% +that type of edch well it tends to be +isotropic or near + + align:start position:0% +isotropic or near + + + align:start position:0% +isotropic or near +isotropic um and not very good uh + + align:start position:0% +isotropic um and not very good uh + + + align:start position:0% +isotropic um and not very good uh +selectivity over si2 so if you hit the + + align:start position:0% +selectivity over si2 so if you hit the + + + align:start position:0% +selectivity over si2 so if you hit the +once you hit the S2 you continue etching + + align:start position:0% +once you hit the S2 you continue etching + + + align:start position:0% +once you hit the S2 you continue etching +so this is a general purpose etch you + + align:start position:0% +so this is a general purpose etch you + + + align:start position:0% +so this is a general purpose etch you +might use if you're trying to strip off + + align:start position:0% +might use if you're trying to strip off + + + align:start position:0% +might use if you're trying to strip off +some poly off the back of the wafer or + + align:start position:0% +some poly off the back of the wafer or + + + align:start position:0% +some poly off the back of the wafer or +something probably not something you + + align:start position:0% +something probably not something you + + + align:start position:0% +something probably not something you +might use if you need uh anot an + + align:start position:0% +might use if you need uh anot an + + + align:start position:0% +might use if you need uh anot an +isotropy or something like that + + align:start position:0% +isotropy or something like that + + + align:start position:0% +isotropy or something like that +um the uh a more anisotropic edch but + + align:start position:0% +um the uh a more anisotropic edch but + + + align:start position:0% +um the uh a more anisotropic edch but +also very not not very selective to sio2 + + align:start position:0% +also very not not very selective to sio2 + + + align:start position:0% +also very not not very selective to sio2 +would be a mixture of cf4 and hydrogen + + align:start position:0% +would be a mixture of cf4 and hydrogen + + + align:start position:0% +would be a mixture of cf4 and hydrogen +or or chf3 some of these fron + + align:start position:0% +or or chf3 some of these fron + + + align:start position:0% +or or chf3 some of these fron +types um you can mix cf4 with oxygen I + + align:start position:0% +types um you can mix cf4 with oxygen I + + + align:start position:0% +types um you can mix cf4 with oxygen I +think we showed last time an example of + + align:start position:0% +think we showed last time an example of + + + align:start position:0% +think we showed last time an example of +the chemistry of this it's uh isotropic + + align:start position:0% +the chemistry of this it's uh isotropic + + + align:start position:0% +the chemistry of this it's uh isotropic +generally reasonably isotropic but is + + align:start position:0% +generally reasonably isotropic but is + + + align:start position:0% +generally reasonably isotropic but is +more selective to + + align:start position:0% +more selective to + + + align:start position:0% +more selective to +sio2 again A lot of times you're etching + + align:start position:0% +sio2 again A lot of times you're etching + + + align:start position:0% +sio2 again A lot of times you're etching +Poly on top of oxide some dialectric and + + align:start position:0% +Poly on top of oxide some dialectric and + + + align:start position:0% +Poly on top of oxide some dialectric and +so you the selectivity of the edge of + + align:start position:0% +so you the selectivity of the edge of + + + align:start position:0% +so you the selectivity of the edge of +the polysilicon edge to the S2 is very + + align:start position:0% +the polysilicon edge to the S2 is very + + + align:start position:0% +the polysilicon edge to the S2 is very +important the most uh the most commonly + + align:start position:0% +important the most uh the most commonly + + + align:start position:0% +important the most uh the most commonly +used etchant gases today for poly + + align:start position:0% +used etchant gases today for poly + + + align:start position:0% +used etchant gases today for poly +silicon and we'll talk about this when + + align:start position:0% +silicon and we'll talk about this when + + + align:start position:0% +silicon and we'll talk about this when +we talk about gate etching are hbr and + + align:start position:0% +we talk about gate etching are hbr and + + + align:start position:0% +we talk about gate etching are hbr and +chlorine or some combination of hbr + + align:start position:0% +chlorine or some combination of hbr + + + align:start position:0% +chlorine or some combination of hbr +chlorine and oxygen these tend to be + + align:start position:0% +chlorine and oxygen these tend to be + + + align:start position:0% +chlorine and oxygen these tend to be +very anisotropic so you can get very + + align:start position:0% +very anisotropic so you can get very + + + align:start position:0% +very anisotropic so you can get very +well-defined sidewalls and most of them + + align:start position:0% +well-defined sidewalls and most of them + + + align:start position:0% +well-defined sidewalls and most of them +are reasonably selective compared to si2 + + align:start position:0% +are reasonably selective compared to si2 + + + align:start position:0% +are reasonably selective compared to si2 +you can get with hbr and O2 combinations + + align:start position:0% +you can get with hbr and O2 combinations + + + align:start position:0% +you can get with hbr and O2 combinations +you can get up to 100 to one selectivity + + align:start position:0% +you can get up to 100 to one selectivity + + + align:start position:0% +you can get up to 100 to one selectivity +uh depending on the the + + align:start position:0% +uh depending on the the + + + align:start position:0% +uh depending on the the +etcher um if you're using if you want ET + + align:start position:0% +etcher um if you're using if you want ET + + + align:start position:0% +etcher um if you're using if you want ET +single Crystal silicon use exactly the + + align:start position:0% +single Crystal silicon use exactly the + + + align:start position:0% +single Crystal silicon use exactly the +same etch and to use for um poly Crystal + + align:start position:0% +same etch and to use for um poly Crystal + + + align:start position:0% +same etch and to use for um poly Crystal +and silicon in general there's not a big + + align:start position:0% +and silicon in general there's not a big + + + align:start position:0% +and silicon in general there's not a big +difference between the + + align:start position:0% +difference between the + + + align:start position:0% +difference between the +two si uh if you need to chch oxide here + + align:start position:0% +two si uh if you need to chch oxide here + + + align:start position:0% +two si uh if you need to chch oxide here +you can um ET sf6 interesting any of the + + align:start position:0% +you can um ET sf6 interesting any of the + + + align:start position:0% +you can um ET sf6 interesting any of the +fluorinated species will will help you + + align:start position:0% +fluorinated species will will help you + + + align:start position:0% +fluorinated species will will help you +with etching oxide notice sf6 was also + + align:start position:0% +with etching oxide notice sf6 was also + + + align:start position:0% +with etching oxide notice sf6 was also +listed as etching poly so that means + + align:start position:0% +listed as etching poly so that means + + + align:start position:0% +listed as etching poly so that means +it's not a very not a very itive + + align:start position:0% +it's not a very not a very itive + + + align:start position:0% +it's not a very not a very itive +Edge um and isotropic etches include a + + align:start position:0% +Edge um and isotropic etches include a + + + align:start position:0% +Edge um and isotropic etches include a +variety of the frons like C2 F6 and C3 + + align:start position:0% +variety of the frons like C2 F6 and C3 + + + align:start position:0% +variety of the frons like C2 F6 and C3 +f8 um they are somewhat selective over + + align:start position:0% +f8 um they are somewhat selective over + + + align:start position:0% +f8 um they are somewhat selective over +silicon when do we etch oxide in in a + + align:start position:0% +silicon when do we etch oxide in in a + + + align:start position:0% +silicon when do we etch oxide in in a +moss process for example we're often + + align:start position:0% +moss process for example we're often + + + align:start position:0% +moss process for example we're often +etching oxide when we're opening up + + align:start position:0% +etching oxide when we're opening up + + + align:start position:0% +etching oxide when we're opening up +contact holes so we have an you know we + + align:start position:0% +contact holes so we have an you know we + + + align:start position:0% +contact holes so we have an you know we +have an interlayer dialectric of some + + align:start position:0% +have an interlayer dialectric of some + + + align:start position:0% +have an interlayer dialectric of some +sort maybe one or 2,000 anes we need to + + align:start position:0% +sort maybe one or 2,000 anes we need to + + + align:start position:0% +sort maybe one or 2,000 anes we need to +get through it uh and with reasonably + + align:start position:0% +get through it uh and with reasonably + + + align:start position:0% +get through it uh and with reasonably +good control of the sidewalls we also + + align:start position:0% +good control of the sidewalls we also + + + align:start position:0% +good control of the sidewalls we also +need to stop on the Silicon you don't + + align:start position:0% +need to stop on the Silicon you don't + + + align:start position:0% +need to stop on the Silicon you don't +want to etch away your Source drains so + + align:start position:0% +want to etch away your Source drains so + + + align:start position:0% +want to etch away your Source drains so +and isotropy and selectivity are also + + align:start position:0% +and isotropy and selectivity are also + + + align:start position:0% +and isotropy and selectivity are also +very + + align:start position:0% +very + + + align:start position:0% +very +important silicon + + align:start position:0% +important silicon + + + align:start position:0% +important silicon +nitride um there are some isotropic + + align:start position:0% +nitride um there are some isotropic + + + align:start position:0% +nitride um there are some isotropic +etches like cf4 and O2 um an anisotropic + + align:start position:0% +etches like cf4 and O2 um an anisotropic + + + align:start position:0% +etches like cf4 and O2 um an anisotropic +etch cf4 and H2 it's this one is + + align:start position:0% +etch cf4 and H2 it's this one is + + + align:start position:0% +etch cf4 and H2 it's this one is +selective over silicon so it'll stop on + + align:start position:0% +selective over silicon so it'll stop on + + + align:start position:0% +selective over silicon so it'll stop on +Silicon but not over si2 uh and + + align:start position:0% +Silicon but not over si2 uh and + + + align:start position:0% +Silicon but not over si2 uh and +sometimes you have stacks consisting of + + align:start position:0% +sometimes you have stacks consisting of + + + align:start position:0% +sometimes you have stacks consisting of +oxide and nitride and you need to Edge + + align:start position:0% +oxide and nitride and you need to Edge + + + align:start position:0% +oxide and nitride and you need to Edge +one of the two um selectivity + + align:start position:0% +one of the two um selectivity + + + align:start position:0% +one of the two um selectivity +selectively so it gets a little tricky + + align:start position:0% +selectively so it gets a little tricky + + + align:start position:0% +selectively so it gets a little tricky +uh you need to pick the etchant and the + + align:start position:0% +uh you need to pick the etchant and the + + + align:start position:0% +uh you need to pick the etchant and the +reactor + + align:start position:0% + + + + align:start position:0% + +carefully what are some other materials + + align:start position:0% +carefully what are some other materials + + + align:start position:0% +carefully what are some other materials +so those are the more common ones maybe + + align:start position:0% +so those are the more common ones maybe + + + align:start position:0% +so those are the more common ones maybe +a little less common but things that you + + align:start position:0% +a little less common but things that you + + + align:start position:0% +a little less common but things that you +do have to etch often uh in plasmas are + + align:start position:0% +do have to etch often uh in plasmas are + + + align:start position:0% +do have to etch often uh in plasmas are +for example aluminum wiring or aluminum + + align:start position:0% +for example aluminum wiring or aluminum + + + align:start position:0% +for example aluminum wiring or aluminum +contacts need to be etched it's very uh + + align:start position:0% +contacts need to be etched it's very uh + + + align:start position:0% +contacts need to be etched it's very uh +common to use chlorinated species like + + align:start position:0% +common to use chlorinated species like + + + align:start position:0% +common to use chlorinated species like +chlorine or + + align:start position:0% +chlorine or + + + align:start position:0% +chlorine or +chcl3 or a mixture of chlorine and + + align:start position:0% +chcl3 or a mixture of chlorine and + + + align:start position:0% +chcl3 or a mixture of chlorine and +nitrogen um uh chlorine itself can be uh + + align:start position:0% +nitrogen um uh chlorine itself can be uh + + + align:start position:0% +nitrogen um uh chlorine itself can be uh +somewhat isotropic and uh some of these + + align:start position:0% +somewhat isotropic and uh some of these + + + align:start position:0% +somewhat isotropic and uh some of these +other gases are are more + + align:start position:0% +other gases are are more + + + align:start position:0% +other gases are are more +anisotropic tungsten um can be etched uh + + align:start position:0% +anisotropic tungsten um can be etched uh + + + align:start position:0% +anisotropic tungsten um can be etched uh +in sf6 uh or chlorine so you notice a + + align:start position:0% +in sf6 uh or chlorine so you notice a + + + align:start position:0% +in sf6 uh or chlorine so you notice a +lot of the metals these are all metals + + align:start position:0% +lot of the metals these are all metals + + + align:start position:0% +lot of the metals these are all metals +are attacked by + + align:start position:0% +are attacked by + + + align:start position:0% +are attacked by +chlorine uh which isn't too unusual if + + align:start position:0% +chlorine uh which isn't too unusual if + + + align:start position:0% +chlorine uh which isn't too unusual if +you if you know a common wet metal + + align:start position:0% +you if you know a common wet metal + + + align:start position:0% +you if you know a common wet metal +etchant is hydrogen chloride H + + align:start position:0% +etchant is hydrogen chloride H + + + align:start position:0% +etchant is hydrogen chloride H +HCL um so um again etching Titanium or + + align:start position:0% +HCL um so um again etching Titanium or + + + align:start position:0% +HCL um so um again etching Titanium or +Ty nitride these are very common tion + + align:start position:0% +Ty nitride these are very common tion + + + align:start position:0% +Ty nitride these are very common tion +chlorine or um mixtures of chlorine with + + align:start position:0% +chlorine or um mixtures of chlorine with + + + align:start position:0% +chlorine or um mixtures of chlorine with +hydrocarbons fer resist an important + + align:start position:0% +hydrocarbons fer resist an important + + + align:start position:0% +hydrocarbons fer resist an important +thing we need to be able to not etch or + + align:start position:0% +thing we need to be able to not etch or + + + align:start position:0% +thing we need to be able to not etch or +P you know pattern uh so much as uh you + + align:start position:0% +P you know pattern uh so much as uh you + + + align:start position:0% +P you know pattern uh so much as uh you +you typically uh want to strip it uh so + + align:start position:0% +you typically uh want to strip it uh so + + + align:start position:0% +you typically uh want to strip it uh so +an ashing step would include uh an + + align:start position:0% +an ashing step would include uh an + + + align:start position:0% +an ashing step would include uh an +oxygen plasma which which reacts um with + + align:start position:0% +oxygen plasma which which reacts um with + + + align:start position:0% +oxygen plasma which which reacts um with +the photo resist the hydrocarbons and + + align:start position:0% +the photo resist the hydrocarbons and + + + align:start position:0% +the photo resist the hydrocarbons and +removes the photo resist and the nice + + align:start position:0% +removes the photo resist and the nice + + + align:start position:0% +removes the photo resist and the nice +thing about O2 plasma is it's very + + align:start position:0% +thing about O2 plasma is it's very + + + align:start position:0% +thing about O2 plasma is it's very +selective it doesn't etch too much of + + align:start position:0% +selective it doesn't etch too much of + + + align:start position:0% +selective it doesn't etch too much of +any it doesn't etch n nitride does an ex + + align:start position:0% +any it doesn't etch n nitride does an ex + + + align:start position:0% +any it doesn't etch n nitride does an ex +oxide it will Etch A little bit of + + align:start position:0% +oxide it will Etch A little bit of + + + align:start position:0% +oxide it will Etch A little bit of +silicon by oxidation that is it'll + + align:start position:0% +silicon by oxidation that is it'll + + + align:start position:0% +silicon by oxidation that is it'll +oxidize a little bit of a surface + + align:start position:0% +oxidize a little bit of a surface + + + align:start position:0% +oxidize a little bit of a surface +silicon and then if you happen to do an + + align:start position:0% +silicon and then if you happen to do an + + + align:start position:0% +silicon and then if you happen to do an +HF dip that'll get removed so it has a + + align:start position:0% +HF dip that'll get removed so it has a + + + align:start position:0% +HF dip that'll get removed so it has a +small amount of silicon removal by an + + align:start position:0% +small amount of silicon removal by an + + + align:start position:0% +small amount of silicon removal by an +oxidation + + align:start position:0% +oxidation + + + align:start position:0% +oxidation +process so again that's uh on page three + + align:start position:0% +process so again that's uh on page three + + + align:start position:0% +process so again that's uh on page three +that's that's the second half of the + + align:start position:0% +that's that's the second half of the + + + align:start position:0% +that's that's the second half of the +chart I took directly from chapter 10 in + + align:start position:0% +chart I took directly from chapter 10 in + + + align:start position:0% +chart I took directly from chapter 10 in +your textbook some common + + align:start position:0% +your textbook some common + + + align:start position:0% +your textbook some common +etchants now I wanted to go uh here on + + align:start position:0% +etchants now I wanted to go uh here on + + + align:start position:0% +etchants now I wanted to go uh here on +on um on slide four I wanted to go + + align:start position:0% +on um on slide four I wanted to go + + + align:start position:0% +on um on slide four I wanted to go +through some um etching challenges in in + + align:start position:0% +through some um etching challenges in in + + + align:start position:0% +through some um etching challenges in in +Moss frontend processing uh from the + + align:start position:0% +Moss frontend processing uh from the + + + align:start position:0% +Moss frontend processing uh from the +last 5 years or so and I'll talk about a + + align:start position:0% +last 5 years or so and I'll talk about a + + + align:start position:0% +last 5 years or so and I'll talk about a +couple of them one is uh for example um + + align:start position:0% +couple of them one is uh for example um + + + align:start position:0% +couple of them one is uh for example um +we've talked about in the past uh Dam a + + align:start position:0% +we've talked about in the past uh Dam a + + + align:start position:0% +we've talked about in the past uh Dam a +dynamic Random Access Memory uh there + + align:start position:0% +dynamic Random Access Memory uh there + + + align:start position:0% +dynamic Random Access Memory uh there +are different ways of storing the charge + + align:start position:0% +are different ways of storing the charge + + + align:start position:0% +are different ways of storing the charge +uh in that memory uh you need to make a + + align:start position:0% +uh in that memory uh you need to make a + + + align:start position:0% +uh in that memory uh you need to make a +capacitor of some sort uh on which you + + align:start position:0% +capacitor of some sort uh on which you + + + align:start position:0% +capacitor of some sort uh on which you +store charge and that is your bit + + align:start position:0% +store charge and that is your bit + + + align:start position:0% +store charge and that is your bit +whether there's charge there or non + + align:start position:0% +whether there's charge there or non + + + align:start position:0% +whether there's charge there or non +charge there tells you whether you have + + align:start position:0% +charge there tells you whether you have + + + align:start position:0% +charge there tells you whether you have +a one or a zero um this capacitor you + + align:start position:0% +a one or a zero um this capacitor you + + + align:start position:0% +a one or a zero um this capacitor you +might think well let's just put a + + align:start position:0% +might think well let's just put a + + + align:start position:0% +might think well let's just put a +capacitor on the substrate we all know + + align:start position:0% +capacitor on the substrate we all know + + + align:start position:0% +capacitor on the substrate we all know +how to make an MLs capacitor but the + + align:start position:0% +how to make an MLs capacitor but the + + + align:start position:0% +how to make an MLs capacitor but the +problem is to make very high density + + align:start position:0% +problem is to make very high density + + + align:start position:0% +problem is to make very high density +damps you can't just make a capacitor + + align:start position:0% +damps you can't just make a capacitor + + + align:start position:0% +damps you can't just make a capacitor +flat on the Silicon substrate you can + + align:start position:0% +flat on the Silicon substrate you can + + + align:start position:0% +flat on the Silicon substrate you can +but then it takes up too much area so + + align:start position:0% +but then it takes up too much area so + + + align:start position:0% +but then it takes up too much area so +people have all different types of ways + + align:start position:0% +people have all different types of ways + + + align:start position:0% +people have all different types of ways +people are thinking of ways of stacking + + align:start position:0% +people are thinking of ways of stacking + + + align:start position:0% +people are thinking of ways of stacking +the capacitor on top of the transistor + + align:start position:0% +the capacitor on top of the transistor + + + align:start position:0% +the capacitor on top of the transistor +that's one method a stacked capacitor + + align:start position:0% +that's one method a stacked capacitor + + + align:start position:0% +that's one method a stacked capacitor +topology another method is take the + + align:start position:0% +topology another method is take the + + + align:start position:0% +topology another method is take the +capacitor and bury it down in the + + align:start position:0% +capacitor and bury it down in the + + + align:start position:0% +capacitor and bury it down in the +substrate somewhere so you can get a + + align:start position:0% +substrate somewhere so you can get a + + + align:start position:0% +substrate somewhere so you can get a +smaller area for your damp cell you can + + align:start position:0% +smaller area for your damp cell you can + + + align:start position:0% +smaller area for your damp cell you can +pack more memory on a given ship and + + align:start position:0% +pack more memory on a given ship and + + + align:start position:0% +pack more memory on a given ship and +then uh you'll have uh you'll have uh + + align:start position:0% +then uh you'll have uh you'll have uh + + + align:start position:0% +then uh you'll have uh you'll have uh +you know much higher performance so this + + align:start position:0% +you know much higher performance so this + + + align:start position:0% +you know much higher performance so this +is an example where you might need to + + align:start position:0% +is an example where you might need to + + + align:start position:0% +is an example where you might need to +etge down into a a silicon substrate to + + align:start position:0% +etge down into a a silicon substrate to + + + align:start position:0% +etge down into a a silicon substrate to +make a trench prior to making a + + align:start position:0% +make a trench prior to making a + + + align:start position:0% +make a trench prior to making a +capacitor this is just an example where + + align:start position:0% +capacitor this is just an example where + + + align:start position:0% +capacitor this is just an example where +you have edged a trench that looks like + + align:start position:0% +you have edged a trench that looks like + + + align:start position:0% +you have edged a trench that looks like +this um lined it with oxide and then uh + + align:start position:0% +this um lined it with oxide and then uh + + + align:start position:0% +this um lined it with oxide and then uh +filled it up with polysilicon to make + + align:start position:0% +filled it up with polysilicon to make + + + align:start position:0% +filled it up with polysilicon to make +one of the plates of the um of the + + align:start position:0% +one of the plates of the um of the + + + align:start position:0% +one of the plates of the um of the +electrode the other plate of electrode + + align:start position:0% +electrode the other plate of electrode + + + align:start position:0% +electrode the other plate of electrode +could be the surrounding silicon + + align:start position:0% +could be the surrounding silicon + + + align:start position:0% +could be the surrounding silicon +material um so so and I took this out of + + align:start position:0% +material um so so and I took this out of + + + align:start position:0% +material um so so and I took this out of +the IBM Journal of research and + + align:start position:0% +the IBM Journal of research and + + + align:start position:0% +the IBM Journal of research and +development just off the web if you want + + align:start position:0% +development just off the web if you want + + + align:start position:0% +development just off the web if you want +to look at that in more detail but so we + + align:start position:0% +to look at that in more detail but so we + + + align:start position:0% +to look at that in more detail but so we +need to make very high aspect ratio + + align:start position:0% +need to make very high aspect ratio + + + align:start position:0% +need to make very high aspect ratio +edges uh for these trenches and we also + + align:start position:0% +edges uh for these trenches and we also + + + align:start position:0% +edges uh for these trenches and we also +need to care about the damage that we do + + align:start position:0% +need to care about the damage that we do + + + align:start position:0% +need to care about the damage that we do +to the Silicon because it's going to be + + align:start position:0% +to the Silicon because it's going to be + + + align:start position:0% +to the Silicon because it's going to be +part of a capacitor so we want it to + + align:start position:0% +part of a capacitor so we want it to + + + align:start position:0% +part of a capacitor so we want it to +have smooth surfaces and things so that + + align:start position:0% +have smooth surfaces and things so that + + + align:start position:0% +have smooth surfaces and things so that +we don't break down the oxide and we get + + align:start position:0% +we don't break down the oxide and we get + + + align:start position:0% +we don't break down the oxide and we get +we get a good electrical performance uh + + align:start position:0% +we get a good electrical performance uh + + + align:start position:0% +we get a good electrical performance uh +of the + + align:start position:0% +of the + + + align:start position:0% +of the +capacitor in fact let's see let's take a + + align:start position:0% +capacitor in fact let's see let's take a + + + align:start position:0% +capacitor in fact let's see let's take a +look here at at page five I took this + + align:start position:0% +look here at at page five I took this + + + align:start position:0% +look here at at page five I took this +from the 20 3 + + align:start position:0% +from the 20 3 + + + align:start position:0% +from the 20 3 +itrs uh table 73 this is just for um + + align:start position:0% +itrs uh table 73 this is just for um + + + align:start position:0% +itrs uh table 73 this is just for um +dram trench capacitors what are some of + + align:start position:0% +dram trench capacitors what are some of + + + align:start position:0% +dram trench capacitors what are some of +the technology requirements we're + + align:start position:0% +the technology requirements we're + + + align:start position:0% +the technology requirements we're +looking at of a long term here going + + align:start position:0% +looking at of a long term here going + + + align:start position:0% +looking at of a long term here going +from um 2010 all the way out to 2020 or + + align:start position:0% +from um 2010 all the way out to 2020 or + + + align:start position:0% +from um 2010 all the way out to 2020 or +2018 what are people expect they might + + align:start position:0% +2018 what are people expect they might + + + align:start position:0% +2018 what are people expect they might +um + + align:start position:0% +um + + + align:start position:0% +um +need um well here there are uh some + + align:start position:0% +need um well here there are uh some + + + align:start position:0% +need um well here there are uh some +indications here of of characteristics + + align:start position:0% +indications here of of characteristics + + + align:start position:0% +indications here of of characteristics +they have things called the trench + + align:start position:0% +they have things called the trench + + + align:start position:0% +they have things called the trench +structure how it will be shaped maybe + + align:start position:0% +structure how it will be shaped maybe + + + align:start position:0% +structure how it will be shaped maybe +more like an upside down bottle + + align:start position:0% +more like an upside down bottle + + + align:start position:0% +more like an upside down bottle +um the circumference of the trench uh + + align:start position:0% +um the circumference of the trench uh + + + align:start position:0% +um the circumference of the trench uh +the trench surfus roughting roughening + + align:start position:0% +the trench surfus roughting roughening + + + align:start position:0% +the trench surfus roughting roughening +Factor um the uh effective oxide + + align:start position:0% +Factor um the uh effective oxide + + + align:start position:0% +Factor um the uh effective oxide +thickness that people will be using in + + align:start position:0% +thickness that people will be using in + + + align:start position:0% +thickness that people will be using in +that trench uh capacitor just to give + + align:start position:0% +that trench uh capacitor just to give + + + align:start position:0% +that trench uh capacitor just to give +you an idea uh in nanometers here we're + + align:start position:0% +you an idea uh in nanometers here we're + + + align:start position:0% +you an idea uh in nanometers here we're +talking about several nanometers maybe + + align:start position:0% +talking about several nanometers maybe + + + align:start position:0% +talking about several nanometers maybe +two nanometers scaling even thinner and + + align:start position:0% +two nanometers scaling even thinner and + + + align:start position:0% +two nanometers scaling even thinner and +thinner um the trench depth in microns + + align:start position:0% +thinner um the trench depth in microns + + + align:start position:0% +thinner um the trench depth in microns +uh for this would be a 30 for a 35 fto + + align:start position:0% +uh for this would be a 30 for a 35 fto + + + align:start position:0% +uh for this would be a 30 for a 35 fto +farad uh capacitor just as an example + + align:start position:0% +farad uh capacitor just as an example + + + align:start position:0% +farad uh capacitor just as an example +how deep will we have to etch um uh + + align:start position:0% +how deep will we have to etch um uh + + + align:start position:0% +how deep will we have to etch um uh +reasonably deep somewhere between five + + align:start position:0% +reasonably deep somewhere between five + + + align:start position:0% +reasonably deep somewhere between five +to seven microns is what people are + + align:start position:0% +to seven microns is what people are + + + align:start position:0% +to seven microns is what people are +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +doing aspect ratio so remember we talked + + align:start position:0% +doing aspect ratio so remember we talked + + + align:start position:0% +doing aspect ratio so remember we talked +about aspect ratio as being an important + + align:start position:0% +about aspect ratio as being an important + + + align:start position:0% +about aspect ratio as being an important +attribute of our capabilities for + + align:start position:0% +attribute of our capabilities for + + + align:start position:0% +attribute of our capabilities for +etching well here so here is the trench + + align:start position:0% +etching well here so here is the trench + + + align:start position:0% +etching well here so here is the trench +depth divided by its width we're talking + + align:start position:0% +depth divided by its width we're talking + + + align:start position:0% +depth divided by its width we're talking +about very high aspect ratios that are + + align:start position:0% +about very high aspect ratios that are + + + align:start position:0% +about very high aspect ratios that are +increasing and they're also quite large + + align:start position:0% +increasing and they're also quite large + + + align:start position:0% +increasing and they're also quite large +in 2010 which is a ways off we're + + align:start position:0% +in 2010 which is a ways off we're + + + align:start position:0% +in 2010 which is a ways off we're +reaching aspect ratio is on the order of + + align:start position:0% +reaching aspect ratio is on the order of + + + align:start position:0% +reaching aspect ratio is on the order of +100 and beyond that going even higher + + align:start position:0% +100 and beyond that going even higher + + + align:start position:0% +100 and beyond that going even higher +and you notice Beyond 100 there the um + + align:start position:0% +and you notice Beyond 100 there the um + + + align:start position:0% +and you notice Beyond 100 there the um +cells are all marked red uh indicating + + align:start position:0% +cells are all marked red uh indicating + + + align:start position:0% +cells are all marked red uh indicating +that in that range um people don't + + align:start position:0% +that in that range um people don't + + + align:start position:0% +that in that range um people don't +really know yet how to etch such deep + + align:start position:0% +really know yet how to etch such deep + + + align:start position:0% +really know yet how to etch such deep +aspect ratio um 100 to one um so new + + align:start position:0% +aspect ratio um 100 to one um so new + + + align:start position:0% +aspect ratio um 100 to one um so new +technology is going to have to be + + align:start position:0% +technology is going to have to be + + + align:start position:0% +technology is going to have to be +developed in order to do + + align:start position:0% +developed in order to do + + + align:start position:0% +developed in order to do +that uh they have some indications here + + align:start position:0% +that uh they have some indications here + + + align:start position:0% +that uh they have some indications here +also of what the upper electrode might + + align:start position:0% +also of what the upper electrode might + + + align:start position:0% +also of what the upper electrode might +be made of uh it seems to be metal the + + align:start position:0% +be made of uh it seems to be metal the + + + align:start position:0% +be made of uh it seems to be metal the +dialectric material uh people are + + align:start position:0% +dialectric material uh people are + + + align:start position:0% +dialectric material uh people are +talking about using uh High case again + + align:start position:0% +talking about using uh High case again + + + align:start position:0% +talking about using uh High case again +you're trying to store a fair amount of + + align:start position:0% +you're trying to store a fair amount of + + + align:start position:0% +you're trying to store a fair amount of +charge in a small space you can do that + + align:start position:0% +charge in a small space you can do that + + + align:start position:0% +charge in a small space you can do that +with a um a higher dialectric constant + + align:start position:0% +with a um a higher dialectric constant + + + align:start position:0% +with a um a higher dialectric constant +the bottom uh electrode um could be a + + align:start position:0% +the bottom uh electrode um could be a + + + align:start position:0% +the bottom uh electrode um could be a +combination of silicon and metals uh as + + align:start position:0% +combination of silicon and metals uh as + + + align:start position:0% +combination of silicon and metals uh as +well so just just give you an idea what + + align:start position:0% +well so just just give you an idea what + + + align:start position:0% +well so just just give you an idea what +kind of trenches one needs to etch and + + align:start position:0% +kind of trenches one needs to etch and + + + align:start position:0% +kind of trenches one needs to etch and +this increase in the aspect ratio uh is + + align:start position:0% +this increase in the aspect ratio uh is + + + align:start position:0% +this increase in the aspect ratio uh is +um you know is is pretty amazing in + + align:start position:0% +um you know is is pretty amazing in + + + align:start position:0% +um you know is is pretty amazing in +terms of what tech what technology + + align:start position:0% +terms of what tech what technology + + + align:start position:0% +terms of what tech what technology +requirements are going to be imposed on + + align:start position:0% +requirements are going to be imposed on + + + align:start position:0% +requirements are going to be imposed on +uh on Advanced etching techniques + + align:start position:0% +uh on Advanced etching techniques + + + align:start position:0% +uh on Advanced etching techniques +okay so that's one example uh if I move + + align:start position:0% +okay so that's one example uh if I move + + + align:start position:0% +okay so that's one example uh if I move +on to slide six uh we not only have to + + align:start position:0% +on to slide six uh we not only have to + + + align:start position:0% +on to slide six uh we not only have to +etch silicon into the the single Crystal + + align:start position:0% +etch silicon into the the single Crystal + + + align:start position:0% +etch silicon into the the single Crystal +material but we also have to etch + + align:start position:0% +material but we also have to etch + + + align:start position:0% +material but we also have to etch +silicon when we're etching the gate and + + align:start position:0% +silicon when we're etching the gate and + + + align:start position:0% +silicon when we're etching the gate and +uh in fact etching the gate is becoming + + align:start position:0% +uh in fact etching the gate is becoming + + + align:start position:0% +uh in fact etching the gate is becoming +more and more complicated this is an + + align:start position:0% +more and more complicated this is an + + + align:start position:0% +more and more complicated this is an +example on slide six of what etching + + align:start position:0% +example on slide six of what etching + + + align:start position:0% +example on slide six of what etching +what we call a compound gate or a gate + + align:start position:0% +what we call a compound gate or a gate + + + align:start position:0% +what we call a compound gate or a gate +that that that already has a gate stack + + align:start position:0% +that that that already has a gate stack + + + align:start position:0% +that that that already has a gate stack +or already has several materials um that + + align:start position:0% +or already has several materials um that + + + align:start position:0% +or already has several materials um that +it consists of uh and I apologize this + + align:start position:0% +it consists of uh and I apologize this + + + align:start position:0% +it consists of uh and I apologize this +is not a very good sem um I took this + + align:start position:0% +is not a very good sem um I took this + + + align:start position:0% +is not a very good sem um I took this +off the website again from that IBM + + align:start position:0% +off the website again from that IBM + + + align:start position:0% +off the website again from that IBM +article um and what it is is on on the + + align:start position:0% +article um and what it is is on on the + + + align:start position:0% +article um and what it is is on on the +very top there is photo resist that has + + align:start position:0% +very top there is photo resist that has + + + align:start position:0% +very top there is photo resist that has +been etched that has been patterned I + + align:start position:0% +been etched that has been patterned I + + + align:start position:0% +been etched that has been patterned I +should say then there is a layer of + + align:start position:0% +should say then there is a layer of + + + align:start position:0% +should say then there is a layer of +tungsten pilicide that has been etched + + align:start position:0% +tungsten pilicide that has been etched + + + align:start position:0% +tungsten pilicide that has been etched +and then there's a layer below it of + + align:start position:0% +and then there's a layer below it of + + + align:start position:0% +and then there's a layer below it of +polycrystal and silicon that's been + + align:start position:0% +polycrystal and silicon that's been + + + align:start position:0% +polycrystal and silicon that's been +etched down to say the oxide uh down to + + align:start position:0% +etched down to say the oxide uh down to + + + align:start position:0% +etched down to say the oxide uh down to +the gate oxide and when presented with + + align:start position:0% +the gate oxide and when presented with + + + align:start position:0% +the gate oxide and when presented with +something like this you have to think + + align:start position:0% +something like this you have to think + + + align:start position:0% +something like this you have to think +about using two different types uh after + + align:start position:0% +about using two different types uh after + + + align:start position:0% +about using two different types uh after +you um uh pattern your photo resist and + + align:start position:0% +you um uh pattern your photo resist and + + + align:start position:0% +you um uh pattern your photo resist and +you develop it and you're ready to etch + + align:start position:0% +you develop it and you're ready to etch + + + align:start position:0% +you develop it and you're ready to etch +it you underneath you have two different + + align:start position:0% +it you underneath you have two different + + + align:start position:0% +it you underneath you have two different +types of layers you need to etch a + + align:start position:0% +types of layers you need to etch a + + + align:start position:0% +types of layers you need to etch a +pilicide layer in this example which was + + align:start position:0% +pilicide layer in this example which was + + + align:start position:0% +pilicide layer in this example which was +pre-existing uh as a uniform layer it + + align:start position:0% +pre-existing uh as a uniform layer it + + + align:start position:0% +pre-existing uh as a uniform layer it +has to be etched and then you need to + + align:start position:0% +has to be etched and then you need to + + + align:start position:0% +has to be etched and then you need to +stop on the silicon and then switch + + align:start position:0% +stop on the silicon and then switch + + + align:start position:0% +stop on the silicon and then switch +gases to etch the poly silicon + + align:start position:0% +gases to etch the poly silicon + + + align:start position:0% +gases to etch the poly silicon +underneath now this gets a little tricky + + align:start position:0% +underneath now this gets a little tricky + + + align:start position:0% +underneath now this gets a little tricky +so you have two different Edge gases + + align:start position:0% +so you have two different Edge gases + + + align:start position:0% +so you have two different Edge gases +that doesn't sound too bad you have an + + align:start position:0% +that doesn't sound too bad you have an + + + align:start position:0% +that doesn't sound too bad you have an +edge gas to etge the poly the tungsten + + align:start position:0% +edge gas to etge the poly the tungsten + + + align:start position:0% +edge gas to etge the poly the tungsten +silicide and another series of gases you + + align:start position:0% +silicide and another series of gases you + + + align:start position:0% +silicide and another series of gases you +used to etch the + + align:start position:0% +used to etch the + + + align:start position:0% +used to etch the +polysilicon um one problem though you + + align:start position:0% +polysilicon um one problem though you + + + align:start position:0% +polysilicon um one problem though you +can come across uh for example tungsten + + align:start position:0% +can come across uh for example tungsten + + + align:start position:0% +can come across uh for example tungsten +pilicides uh may not be super pure it + + align:start position:0% +pilicides uh may not be super pure it + + + align:start position:0% +pilicides uh may not be super pure it +may have some oxides incorporated into + + align:start position:0% +may have some oxides incorporated into + + + align:start position:0% +may have some oxides incorporated into +it um uh and uh this these these oxides + + align:start position:0% +it um uh and uh this these these oxides + + + align:start position:0% +it um uh and uh this these these oxides +won't etch if the chch and uh is highly + + align:start position:0% +won't etch if the chch and uh is highly + + + align:start position:0% +won't etch if the chch and uh is highly +selective to oxide so if you're using a + + align:start position:0% +selective to oxide so if you're using a + + + align:start position:0% +selective to oxide so if you're using a +single etch gas that is very selective + + align:start position:0% +single etch gas that is very selective + + + align:start position:0% +single etch gas that is very selective +to oxide say is what you might want to + + align:start position:0% +to oxide say is what you might want to + + + align:start position:0% +to oxide say is what you might want to +do for the poly that same ET gas might + + align:start position:0% +do for the poly that same ET gas might + + + align:start position:0% +do for the poly that same ET gas might +not do very well in the tungsten + + align:start position:0% +not do very well in the tungsten + + + align:start position:0% +not do very well in the tungsten +pilicide and uh what happens when you + + align:start position:0% +pilicide and uh what happens when you + + + align:start position:0% +pilicide and uh what happens when you +use an etching gas that is very + + align:start position:0% +use an etching gas that is very + + + align:start position:0% +use an etching gas that is very +selective to oxide and you don't do a + + align:start position:0% +selective to oxide and you don't do a + + + align:start position:0% +selective to oxide and you don't do a +breakthrough if you have any native + + align:start position:0% +breakthrough if you have any native + + + align:start position:0% +breakthrough if you have any native +oxide on top of that structure and you + + align:start position:0% +oxide on top of that structure and you + + + align:start position:0% +oxide on top of that structure and you +don't break through it you'll end up + + align:start position:0% +don't break through it you'll end up + + + align:start position:0% +don't break through it you'll end up +with something called R grass um and + + align:start position:0% +with something called R grass um and + + + align:start position:0% +with something called R grass um and +it's called grass because it looks like + + align:start position:0% +it's called grass because it looks like + + + align:start position:0% +it's called grass because it looks like +grass in the sem let me on the next + + align:start position:0% +grass in the sem let me on the next + + + align:start position:0% +grass in the sem let me on the next +slide I'll show you a picture of + + align:start position:0% +slide I'll show you a picture of + + + align:start position:0% +slide I'll show you a picture of +grass on page on slide + + align:start position:0% +grass on page on slide + + + align:start position:0% +grass on page on slide +seven um this is an example of an + + align:start position:0% +seven um this is an example of an + + + align:start position:0% +seven um this is an example of an +extreme case of Rie grass and you have a + + align:start position:0% +extreme case of Rie grass and you have a + + + align:start position:0% +extreme case of Rie grass and you have a +flat substrate down to which you have + + align:start position:0% +flat substrate down to which you have + + + align:start position:0% +flat substrate down to which you have +etched + + align:start position:0% +etched + + + align:start position:0% +etched +um and sometimes it's called + + align:start position:0% +um and sometimes it's called + + + align:start position:0% +um and sometimes it's called +micromasking and what happened in + + align:start position:0% +micromasking and what happened in + + + align:start position:0% +micromasking and what happened in +etchant was used to etch this gate + + align:start position:0% +etchant was used to etch this gate + + + align:start position:0% +etchant was used to etch this gate +whatever this material is and etent was + + align:start position:0% +whatever this material is and etent was + + + align:start position:0% +whatever this material is and etent was +used that had a very high selectivity of + + align:start position:0% +used that had a very high selectivity of + + + align:start position:0% +used that had a very high selectivity of +oxide um and there were apparently small + + align:start position:0% +oxide um and there were apparently small + + + align:start position:0% +oxide um and there were apparently small +say oxide inclusions uh at the surface + + align:start position:0% +say oxide inclusions uh at the surface + + + align:start position:0% +say oxide inclusions uh at the surface +of the wafer when when the etch was + + align:start position:0% +of the wafer when when the etch was + + + align:start position:0% +of the wafer when when the etch was +started uh that didn't get fully removed + + align:start position:0% +started uh that didn't get fully removed + + + align:start position:0% +started uh that didn't get fully removed +and so those small oxide areas will act + + align:start position:0% +and so those small oxide areas will act + + + align:start position:0% +and so those small oxide areas will act +like little micro masks they wer were + + align:start position:0% +like little micro masks they wer were + + + align:start position:0% +like little micro masks they wer were +not intentionally put there but there's + + align:start position:0% +not intentionally put there but there's + + + align:start position:0% +not intentionally put there but there's +just a little bit of oxide here and + + align:start position:0% +just a little bit of oxide here and + + + align:start position:0% +just a little bit of oxide here and +there um that the so a breakthrough etch + + align:start position:0% +there um that the so a breakthrough etch + + + align:start position:0% +there um that the so a breakthrough etch +wasn't used as a result if the if the + + align:start position:0% +wasn't used as a result if the if the + + + align:start position:0% +wasn't used as a result if the if the +etch that you're using is highly + + align:start position:0% +etch that you're using is highly + + + align:start position:0% +etch that you're using is highly +selective to oxide it'll never etch it + + align:start position:0% +selective to oxide it'll never etch it + + + align:start position:0% +selective to oxide it'll never etch it +and instead you end up with little posts + + align:start position:0% +and instead you end up with little posts + + + align:start position:0% +and instead you end up with little posts +uh which look like little little blades + + align:start position:0% +uh which look like little little blades + + + align:start position:0% +uh which look like little little blades +of grass um the solution to this is well + + align:start position:0% +of grass um the solution to this is well + + + align:start position:0% +of grass um the solution to this is well +you could say well don't use an ed + + align:start position:0% +you could say well don't use an ed + + + align:start position:0% +you could say well don't use an ed +that's so selective to oxide but you if + + align:start position:0% +that's so selective to oxide but you if + + + align:start position:0% +that's so selective to oxide but you if +you want to stop on S2 you wouldn't want + + align:start position:0% +you want to stop on S2 you wouldn't want + + + align:start position:0% +you want to stop on S2 you wouldn't want +to do that the solution is the very + + align:start position:0% +to do that the solution is the very + + + align:start position:0% +to do that the solution is the very +first part of your Edge step should be a + + align:start position:0% +first part of your Edge step should be a + + + align:start position:0% +first part of your Edge step should be a +breakthrough Edge where you make sure + + align:start position:0% +breakthrough Edge where you make sure + + + align:start position:0% +breakthrough Edge where you make sure +you break through all the native oxide + + align:start position:0% +you break through all the native oxide + + + align:start position:0% +you break through all the native oxide +and then you continue on down so it gets + + align:start position:0% +and then you continue on down so it gets + + + align:start position:0% +and then you continue on down so it gets +a little tricky um when you start um + + align:start position:0% +a little tricky um when you start um + + + align:start position:0% +a little tricky um when you start um +etching multiple materials or when when + + align:start position:0% +etching multiple materials or when when + + + align:start position:0% +etching multiple materials or when when +uh you uh you have to think about the + + align:start position:0% +uh you uh you have to think about the + + + align:start position:0% +uh you uh you have to think about the +fact that there may be materials on the + + align:start position:0% +fact that there may be materials on the + + + align:start position:0% +fact that there may be materials on the +wafer you don't know + + align:start position:0% +wafer you don't know + + + align:start position:0% +wafer you don't know +about Native silicon dioxide may be + + align:start position:0% +about Native silicon dioxide may be + + + align:start position:0% +about Native silicon dioxide may be +there even if you didn't put it there it + + align:start position:0% +there even if you didn't put it there it + + + align:start position:0% +there even if you didn't put it there it +grows there automatically on the wafer + + align:start position:0% +grows there automatically on the wafer + + + align:start position:0% +grows there automatically on the wafer +so you have to remember that you do get + + align:start position:0% +so you have to remember that you do get + + + align:start position:0% +so you have to remember that you do get +it off the surface before you use a + + align:start position:0% +it off the surface before you use a + + + align:start position:0% +it off the surface before you use a +highly selective + + align:start position:0% + + + + align:start position:0% + +Edge um on slide eight what I've done is + + align:start position:0% +Edge um on slide eight what I've done is + + + align:start position:0% +Edge um on slide eight what I've done is +I've I've listed some what I call + + align:start position:0% +I've I've listed some what I call + + + align:start position:0% +I've I've listed some what I call +etching challenges in MOS front and + + align:start position:0% +etching challenges in MOS front and + + + align:start position:0% +etching challenges in MOS front and +processing as they apply to gate etching + + align:start position:0% +processing as they apply to gate etching + + + align:start position:0% +processing as they apply to gate etching +uh and uh logic logic devices in + + align:start position:0% +uh and uh logic logic devices in + + + align:start position:0% +uh and uh logic logic devices in +particular uh this is a um on the + + align:start position:0% +particular uh this is a um on the + + + align:start position:0% +particular uh this is a um on the +left-and side is a tem micrograph I + + align:start position:0% +left-and side is a tem micrograph I + + + align:start position:0% +left-and side is a tem micrograph I +think I showed this the very beginning + + align:start position:0% +think I showed this the very beginning + + + align:start position:0% +think I showed this the very beginning +and several times throughout the course + + align:start position:0% +and several times throughout the course + + + align:start position:0% +and several times throughout the course +just to give you an idea of of what a + + align:start position:0% +just to give you an idea of of what a + + + align:start position:0% +just to give you an idea of of what a +device uh five years ago or so might + + align:start position:0% +device uh five years ago or so might + + + align:start position:0% +device uh five years ago or so might +have looked like this is a fairly larger + + align:start position:0% +have looked like this is a fairly larger + + + align:start position:0% +have looked like this is a fairly larger +technology by today's standards but it's + + align:start position:0% +technology by today's standards but it's + + + align:start position:0% +technology by today's standards but it's +it's I think it's a point a quarter + + align:start position:0% +it's I think it's a point a quarter + + + align:start position:0% +it's I think it's a point a quarter +Micron or something like that uh Channel + + align:start position:0% +Micron or something like that uh Channel + + + align:start position:0% +Micron or something like that uh Channel +length technology here is a polycrystal + + align:start position:0% +length technology here is a polycrystal + + + align:start position:0% +length technology here is a polycrystal +silicon gate there's a thin layer + + align:start position:0% +silicon gate there's a thin layer + + + align:start position:0% +silicon gate there's a thin layer +underneath which is the gate oxide + + align:start position:0% +underneath which is the gate oxide + + + align:start position:0% +underneath which is the gate oxide +separates the gate uh from the channel + + align:start position:0% +separates the gate uh from the channel + + + align:start position:0% +separates the gate uh from the channel +and on top there is a layer which is + + align:start position:0% +and on top there is a layer which is + + + align:start position:0% +and on top there is a layer which is +pilicide now that was put there + + align:start position:0% +pilicide now that was put there + + + align:start position:0% +pilicide now that was put there +afterwards in this case so the gate was + + align:start position:0% +afterwards in this case so the gate was + + + align:start position:0% +afterwards in this case so the gate was +first etched and then um metal was put + + align:start position:0% +first etched and then um metal was put + + + align:start position:0% +first etched and then um metal was put +down and then was reacted with the gate + + align:start position:0% +down and then was reacted with the gate + + + align:start position:0% +down and then was reacted with the gate +and the source strain in in a pilicide + + align:start position:0% +and the source strain in in a pilicide + + + align:start position:0% +and the source strain in in a pilicide +or salicide process we'll talk about + + align:start position:0% +or salicide process we'll talk about + + + align:start position:0% +or salicide process we'll talk about +that next lecture when we talk about + + align:start position:0% +that next lecture when we talk about + + + align:start position:0% +that next lecture when we talk about +silicide so you didn't have to etge + + align:start position:0% +silicide so you didn't have to etge + + + align:start position:0% +silicide so you didn't have to etge +through the through this this was + + align:start position:0% +through the through this this was + + + align:start position:0% +through the through this this was +reacted um later on but what do we care + + align:start position:0% +reacted um later on but what do we care + + + align:start position:0% +reacted um later on but what do we care +about well in this picture um first we + + align:start position:0% +about well in this picture um first we + + + align:start position:0% +about well in this picture um first we +need to control the gate length Or the + + align:start position:0% +need to control the gate length Or the + + + align:start position:0% +need to control the gate length Or the +critical Dimension sometimes called the + + align:start position:0% +critical Dimension sometimes called the + + + align:start position:0% +critical Dimension sometimes called the +CD the gate length is is defined between + + align:start position:0% +CD the gate length is is defined between + + + align:start position:0% +CD the gate length is is defined between +from this point to this point so this + + align:start position:0% +from this point to this point so this + + + align:start position:0% +from this point to this point so this +this width or length if you so to speak + + align:start position:0% +this width or length if you so to speak + + + align:start position:0% +this width or length if you so to speak +of the polysilicon needs to be + + align:start position:0% +of the polysilicon needs to be + + + align:start position:0% +of the polysilicon needs to be +controlled exactly on on all um on all + + align:start position:0% +controlled exactly on on all um on all + + + align:start position:0% +controlled exactly on on all um on all +areas of of the Chip And all areas of + + align:start position:0% +areas of of the Chip And all areas of + + + align:start position:0% +areas of of the Chip And all areas of +the + + align:start position:0% +the + + + align:start position:0% +the +wafer the sidewall profile what do I + + align:start position:0% +wafer the sidewall profile what do I + + + align:start position:0% +wafer the sidewall profile what do I +mean by that well this profile going + + align:start position:0% +mean by that well this profile going + + + align:start position:0% +mean by that well this profile going +from the very top down here has to be + + align:start position:0% +from the very top down here has to be + + + align:start position:0% +from the very top down here has to be +controlled you usually want it vertical + + align:start position:0% +controlled you usually want it vertical + + + align:start position:0% +controlled you usually want it vertical +you don't usually want it splay out like + + align:start position:0% +you don't usually want it splay out like + + + align:start position:0% +you don't usually want it splay out like +this you don't want it retrograded like + + align:start position:0% +this you don't want it retrograded like + + + align:start position:0% +this you don't want it retrograded like +this you don't want it straight with a + + align:start position:0% +this you don't want it straight with a + + + align:start position:0% +this you don't want it straight with a +little foot at the bottom you want it + + align:start position:0% +little foot at the bottom you want it + + + align:start position:0% +little foot at the bottom you want it +perfectly vertical and stop that sounds + + align:start position:0% +perfectly vertical and stop that sounds + + + align:start position:0% +perfectly vertical and stop that sounds +kind of trivial but it's not + + align:start position:0% +kind of trivial but it's not + + + align:start position:0% +kind of trivial but it's not +easy um for various reasons uh + + align:start position:0% +easy um for various reasons uh + + + align:start position:0% +easy um for various reasons uh +selectivity we care about as we're + + align:start position:0% +selectivity we care about as we're + + + align:start position:0% +selectivity we care about as we're +etching this polysilicon we don't want + + align:start position:0% +etching this polysilicon we don't want + + + align:start position:0% +etching this polysilicon we don't want +to etch away the resist that that would + + align:start position:0% +to etch away the resist that that would + + + align:start position:0% +to etch away the resist that that would +be masking it on top or whatever mask + + align:start position:0% +be masking it on top or whatever mask + + + align:start position:0% +be masking it on top or whatever mask +material we're using if we're using a + + align:start position:0% +material we're using if we're using a + + + align:start position:0% +material we're using if we're using a +hard mask of si2 so selectivity to the + + align:start position:0% +hard mask of si2 so selectivity to the + + + align:start position:0% +hard mask of si2 so selectivity to the +etge material uh to the masking material + + align:start position:0% +etge material uh to the masking material + + + align:start position:0% +etge material uh to the masking material +is very important + + align:start position:0% +is very important + + + align:start position:0% +is very important +that's one type of selectivity + + align:start position:0% +that's one type of selectivity + + + align:start position:0% +that's one type of selectivity +selectivity to the gate dialectric down + + align:start position:0% +selectivity to the gate dialectric down + + + align:start position:0% +selectivity to the gate dialectric down +here in this um di is is a dialectric + + align:start position:0% +here in this um di is is a dialectric + + + align:start position:0% +here in this um di is is a dialectric +material probably a high K that's + + align:start position:0% +material probably a high K that's + + + align:start position:0% +material probably a high K that's +probably 1 to 2 nmet thick we need to + + align:start position:0% +probably 1 to 2 nmet thick we need to + + + align:start position:0% +probably 1 to 2 nmet thick we need to +stop instantly immediately as soon as we + + align:start position:0% +stop instantly immediately as soon as we + + + align:start position:0% +stop instantly immediately as soon as we +hit it automatically and not go through + + align:start position:0% +hit it automatically and not go through + + + align:start position:0% +hit it automatically and not go through +it and not not uh you know not over Edge + + align:start position:0% +it and not not uh you know not over Edge + + + align:start position:0% +it and not not uh you know not over Edge +too much so uh this is a real issue + + align:start position:0% +too much so uh this is a real issue + + + align:start position:0% +too much so uh this is a real issue +getting uh a chemical selectivity at the + + align:start position:0% +getting uh a chemical selectivity at the + + + align:start position:0% +getting uh a chemical selectivity at the +same time as getting good sidewall + + align:start position:0% +same time as getting good sidewall + + + align:start position:0% +same time as getting good sidewall +profile uh I just mentioned the fact + + align:start position:0% +profile uh I just mentioned the fact + + + align:start position:0% +profile uh I just mentioned the fact +that native oxide is often present on + + align:start position:0% +that native oxide is often present on + + + align:start position:0% +that native oxide is often present on +the polysilicon we have to use a + + align:start position:0% +the polysilicon we have to use a + + + align:start position:0% +the polysilicon we have to use a +breakthrough etch as the initial step of + + align:start position:0% +breakthrough etch as the initial step of + + + align:start position:0% +breakthrough etch as the initial step of +etching otherwise we'll have all kinds + + align:start position:0% +etching otherwise we'll have all kinds + + + align:start position:0% +etching otherwise we'll have all kinds +of um grass + + align:start position:0% +of um grass + + + align:start position:0% +of um grass +problems uh there can be impact of + + align:start position:0% +problems uh there can be impact of + + + align:start position:0% +problems uh there can be impact of +different dopen if you if the dope if + + align:start position:0% +different dopen if you if the dope if + + + align:start position:0% +different dopen if you if the dope if +the gate is doped prior to etching which + + align:start position:0% +the gate is doped prior to etching which + + + align:start position:0% +the gate is doped prior to etching which +it can be if you put down insitu doped + + align:start position:0% +it can be if you put down insitu doped + + + align:start position:0% +it can be if you put down insitu doped +polysilicon the edch rate for a boron or + + align:start position:0% +polysilicon the edch rate for a boron or + + + align:start position:0% +polysilicon the edch rate for a boron or +heavily phosphorous dope poly may be + + align:start position:0% +heavily phosphorous dope poly may be + + + align:start position:0% +heavily phosphorous dope poly may be +different from and it may have different + + align:start position:0% +different from and it may have different + + + align:start position:0% +different from and it may have different +Edge + + align:start position:0% +Edge + + + align:start position:0% +Edge +characteristics um than that of unop so + + align:start position:0% +characteristics um than that of unop so + + + align:start position:0% +characteristics um than that of unop so +you need to take that into account and + + align:start position:0% +you need to take that into account and + + + align:start position:0% +you need to take that into account and +we also mentioned at the very beginning + + align:start position:0% +we also mentioned at the very beginning + + + align:start position:0% +we also mentioned at the very beginning +of the last lecture gate dialectric + + align:start position:0% +of the last lecture gate dialectric + + + align:start position:0% +of the last lecture gate dialectric +damage due to the antenna effect what is + + align:start position:0% +damage due to the antenna effect what is + + + align:start position:0% +damage due to the antenna effect what is +that was you have ions coming down being + + align:start position:0% +that was you have ions coming down being + + + align:start position:0% +that was you have ions coming down being +collected by the gate where do they go + + align:start position:0% +collected by the gate where do they go + + + align:start position:0% +collected by the gate where do they go +well they go they don't go through the + + align:start position:0% +well they go they don't go through the + + + align:start position:0% +well they go they don't go through the +field oxide because that's too thick + + align:start position:0% +field oxide because that's too thick + + + align:start position:0% +field oxide because that's too thick +they get shuttled down the gate and they + + align:start position:0% +they get shuttled down the gate and they + + + align:start position:0% +they get shuttled down the gate and they +go try to um the current tends to go + + align:start position:0% +go try to um the current tends to go + + + align:start position:0% +go try to um the current tends to go +through the gate oxide you have to be + + align:start position:0% +through the gate oxide you have to be + + + align:start position:0% +through the gate oxide you have to be +careful that you don't um put too much + + align:start position:0% +careful that you don't um put too much + + + align:start position:0% +careful that you don't um put too much +current through your gate oxide and + + align:start position:0% +current through your gate oxide and + + + align:start position:0% +current through your gate oxide and +damage it so those are some basic issues + + align:start position:0% +damage it so those are some basic issues + + + align:start position:0% +damage it so those are some basic issues +issues when it comes to poly gate + + align:start position:0% +issues when it comes to poly gate + + + align:start position:0% +issues when it comes to poly gate +etching here's an here's an example on + + align:start position:0% +etching here's an here's an example on + + + align:start position:0% +etching here's an here's an example on +slide nine of a gate etcher it's a + + align:start position:0% +slide nine of a gate etcher it's a + + + align:start position:0% +slide nine of a gate etcher it's a +little bit older technology now but at + + align:start position:0% +little bit older technology now but at + + + align:start position:0% +little bit older technology now but at +the time it was designed by a company + + align:start position:0% +the time it was designed by a company + + + align:start position:0% +the time it was designed by a company +called lamb to be dedicated to um uh + + align:start position:0% +called lamb to be dedicated to um uh + + + align:start position:0% +called lamb to be dedicated to um uh +gate etching only it's called the TCP + + align:start position:0% +gate etching only it's called the TCP + + + align:start position:0% +gate etching only it's called the TCP +9400 um It's relatively low pressure low + + align:start position:0% +9400 um It's relatively low pressure low + + + align:start position:0% +9400 um It's relatively low pressure low +bias high density + + align:start position:0% +bias high density + + + align:start position:0% +bias high density +plasma um has a mechanical clamp truck + + align:start position:0% +plasma um has a mechanical clamp truck + + + align:start position:0% +plasma um has a mechanical clamp truck +remember we talked about the importance + + align:start position:0% +remember we talked about the importance + + + align:start position:0% +remember we talked about the importance +of controlling the temperature of the + + align:start position:0% +of controlling the temperature of the + + + align:start position:0% +of controlling the temperature of the +edge to cool the wafer it's got helium + + align:start position:0% +edge to cool the wafer it's got helium + + + align:start position:0% +edge to cool the wafer it's got helium +on the backside this is an example of a + + align:start position:0% +on the backside this is an example of a + + + align:start position:0% +on the backside this is an example of a +wafer that's front end processing only + + align:start position:0% +wafer that's front end processing only + + + align:start position:0% +wafer that's front end processing only +so no metals are allowed to be go into + + align:start position:0% +so no metals are allowed to be go into + + + align:start position:0% +so no metals are allowed to be go into +the into the uh tool and it you can get + + align:start position:0% +the into the uh tool and it you can get + + + align:start position:0% +the into the uh tool and it you can get +an etch rate of the What's called the + + align:start position:0% +an etch rate of the What's called the + + + align:start position:0% +an etch rate of the What's called the +main etch that's pretty fast in fact + + align:start position:0% +main etch that's pretty fast in fact + + + align:start position:0% +main etch that's pretty fast in fact +higher than you probably need in most + + align:start position:0% +higher than you probably need in most + + + align:start position:0% +higher than you probably need in most +etches today uh the height of the poly + + align:start position:0% +etches today uh the height of the poly + + + align:start position:0% +etches today uh the height of the poly +today is probably only a th000 Anum and + + align:start position:0% +today is probably only a th000 Anum and + + + align:start position:0% +today is probably only a th000 Anum and +this goes at at uh 320 nanometers per + + align:start position:0% +this goes at at uh 320 nanometers per + + + align:start position:0% +this goes at at uh 320 nanometers per +minute so quite uh quite efficient + + align:start position:0% +minute so quite uh quite efficient + + + align:start position:0% +minute so quite uh quite efficient +etching for poly Gates and can give you + + align:start position:0% +etching for poly Gates and can give you + + + align:start position:0% +etching for poly Gates and can give you +the kind of profile shape and activity + + align:start position:0% +the kind of profile shape and activity + + + align:start position:0% +the kind of profile shape and activity +that you + + align:start position:0% +that you + + + align:start position:0% +that you +need if we go on to SL slide 10 this is + + align:start position:0% +need if we go on to SL slide 10 this is + + + align:start position:0% +need if we go on to SL slide 10 this is +just an example of a recipe if we were + + align:start position:0% +just an example of a recipe if we were + + + align:start position:0% +just an example of a recipe if we were +to use that lamb TCP 9400 gate eter uh I + + align:start position:0% +to use that lamb TCP 9400 gate eter uh I + + + align:start position:0% +to use that lamb TCP 9400 gate eter uh I +took this off the Stanford uh website + + align:start position:0% +took this off the Stanford uh website + + + align:start position:0% +took this off the Stanford uh website +this is an actual recipe that they have + + align:start position:0% +this is an actual recipe that they have + + + align:start position:0% +this is an actual recipe that they have +published um showing the individual + + align:start position:0% +published um showing the individual + + + align:start position:0% +published um showing the individual +steps that you would need to use just to + + align:start position:0% +steps that you would need to use just to + + + align:start position:0% +steps that you would need to use just to +give you an idea of some of the + + align:start position:0% +give you an idea of some of the + + + align:start position:0% +give you an idea of some of the +complexity of this etch process now each + + align:start position:0% +complexity of this etch process now each + + + align:start position:0% +complexity of this etch process now each +step they're numbered here 1 through + + align:start position:0% +step they're numbered here 1 through + + + align:start position:0% +step they're numbered here 1 through +nine corresponds to a different time + + align:start position:0% +nine corresponds to a different time + + + align:start position:0% +nine corresponds to a different time +sequence um you know uh different step + + align:start position:0% +sequence um you know uh different step + + + align:start position:0% +sequence um you know uh different step +in the time sequence for the edge so the + + align:start position:0% +in the time sequence for the edge so the + + + align:start position:0% +in the time sequence for the edge so the +very first step label number one um + + align:start position:0% +very first step label number one um + + + align:start position:0% +very first step label number one um +you're adjusting uh the Gap uh which is + + align:start position:0% +you're adjusting uh the Gap uh which is + + + align:start position:0% +you're adjusting uh the Gap uh which is +a parameter inside the tool U the + + align:start position:0% +a parameter inside the tool U the + + + align:start position:0% +a parameter inside the tool U the +pressure is being stabilized at 13 milor + + align:start position:0% +pressure is being stabilized at 13 milor + + + align:start position:0% +pressure is being stabilized at 13 milor +uh automatically by the computer uh and + + align:start position:0% +uh automatically by the computer uh and + + + align:start position:0% +uh automatically by the computer uh and +you're setting up um to uh flow some of + + align:start position:0% +you're setting up um to uh flow some of + + + align:start position:0% +you're setting up um to uh flow some of +your initial gas you're flowing C2 F6 um + + align:start position:0% +your initial gas you're flowing C2 F6 um + + + align:start position:0% +your initial gas you're flowing C2 F6 um +and once you've stabilized U after 20 + + align:start position:0% +and once you've stabilized U after 20 + + + align:start position:0% +and once you've stabilized U after 20 +seconds you go on to the next step + + align:start position:0% +seconds you go on to the next step + + + align:start position:0% +seconds you go on to the next step +okay so the next step is uh step number + + align:start position:0% +okay so the next step is uh step number + + + align:start position:0% +okay so the next step is uh step number +two you're clamping the wafer + + align:start position:0% +two you're clamping the wafer + + + align:start position:0% +two you're clamping the wafer +mechanically to the chuck to get good um + + align:start position:0% +mechanically to the chuck to get good um + + + align:start position:0% +mechanically to the chuck to get good um +you know uh uh control of the + + align:start position:0% +you know uh uh control of the + + + align:start position:0% +you know uh uh control of the +temperature and um you have uh you know + + align:start position:0% +temperature and um you have uh you know + + + align:start position:0% +temperature and um you have uh you know +certain characteristics in that + + align:start position:0% +certain characteristics in that + + + align:start position:0% +certain characteristics in that +step uh so that lasts about 20 seconds + + align:start position:0% +step uh so that lasts about 20 seconds + + + align:start position:0% +step uh so that lasts about 20 seconds +the next is step three is the first etch + + align:start position:0% +the next is step three is the first etch + + + align:start position:0% +the next is step three is the first etch +remember we mentioned when you're using + + align:start position:0% +remember we mentioned when you're using + + + align:start position:0% +remember we mentioned when you're using +a gas that's highly selective you need + + align:start position:0% +a gas that's highly selective you need + + + align:start position:0% +a gas that's highly selective you need +to first start out with a breakthrough + + align:start position:0% +to first start out with a breakthrough + + + align:start position:0% +to first start out with a breakthrough +etch to get through the native oxide + + align:start position:0% +etch to get through the native oxide + + + align:start position:0% +etch to get through the native oxide +here you're etching for about 10 seconds + + align:start position:0% +here you're etching for about 10 seconds + + + align:start position:0% +here you're etching for about 10 seconds +seconds um based on and you you edge + + align:start position:0% +seconds um based on and you you edge + + + align:start position:0% +seconds um based on and you you edge +just for based on time you're flowing C2 + + align:start position:0% +just for based on time you're flowing C2 + + + align:start position:0% +just for based on time you're flowing C2 +F6 uh Al together with uh I guess that's + + align:start position:0% +F6 uh Al together with uh I guess that's + + + align:start position:0% +F6 uh Al together with uh I guess that's +the only thing you're flowing and you've + + align:start position:0% +the only thing you're flowing and you've + + + align:start position:0% +the only thing you're flowing and you've +got um RF power on the top and bottom + + align:start position:0% +got um RF power on the top and bottom + + + align:start position:0% +got um RF power on the top and bottom +250 and 40 watts and your pressure is 13 + + align:start position:0% +250 and 40 watts and your pressure is 13 + + + align:start position:0% +250 and 40 watts and your pressure is 13 +millor so this should break through any + + align:start position:0% +millor so this should break through any + + + align:start position:0% +millor so this should break through any +native oxide for about 10 + + align:start position:0% +native oxide for about 10 + + + align:start position:0% +native oxide for about 10 +seconds um and then the next step is + + align:start position:0% +seconds um and then the next step is + + + align:start position:0% +seconds um and then the next step is +four you need to stabilize the gas flows + + align:start position:0% +four you need to stabilize the gas flows + + + align:start position:0% +four you need to stabilize the gas flows +before the main Edge the main Edge is + + align:start position:0% +before the main Edge the main Edge is + + + align:start position:0% +before the main Edge the main Edge is +The Edge that's going to etge the + + align:start position:0% +The Edge that's going to etge the + + + align:start position:0% +The Edge that's going to etge the +polysilicon so you turn on different + + align:start position:0% +polysilicon so you turn on different + + + align:start position:0% +polysilicon so you turn on different +gases you turn off the C2 F6 you turn on + + align:start position:0% +gases you turn off the C2 F6 you turn on + + + align:start position:0% +gases you turn off the C2 F6 you turn on +the chlorine mixture of chlorine and hbr + + align:start position:0% +the chlorine mixture of chlorine and hbr + + + align:start position:0% +the chlorine mixture of chlorine and hbr +and oxygen that's what we call the main + + align:start position:0% +and oxygen that's what we call the main + + + align:start position:0% +and oxygen that's what we call the main +Edge that's going to do most of the work + + align:start position:0% +Edge that's going to do most of the work + + + align:start position:0% +Edge that's going to do most of the work +in getting you through the polycrystal + + align:start position:0% +in getting you through the polycrystal + + + align:start position:0% +in getting you through the polycrystal +and silicon uh so you're just + + align:start position:0% +and silicon uh so you're just + + + align:start position:0% +and silicon uh so you're just +stabilizing at this point you notice + + align:start position:0% +stabilizing at this point you notice + + + align:start position:0% +stabilizing at this point you notice +there's no power on the top and bottom + + align:start position:0% +there's no power on the top and bottom + + + align:start position:0% +there's no power on the top and bottom +electrodes so you're not actually the + + align:start position:0% +electrodes so you're not actually the + + + align:start position:0% +electrodes so you're not actually the +Plasma's not on so you don't you're not + + align:start position:0% +Plasma's not on so you don't you're not + + + align:start position:0% +Plasma's not on so you don't you're not +lighting a plasma you're just + + align:start position:0% +lighting a plasma you're just + + + align:start position:0% +lighting a plasma you're just +stabilizing the flows through the + + align:start position:0% +stabilizing the flows through the + + + align:start position:0% +stabilizing the flows through the +chamber and that takes a while uh in + + align:start position:0% +chamber and that takes a while uh in + + + align:start position:0% +chamber and that takes a while uh in +this condition in this particular case + + align:start position:0% +this condition in this particular case + + + align:start position:0% +this condition in this particular case +stabilization step is about 20 seconds + + align:start position:0% +stabilization step is about 20 seconds + + + align:start position:0% +stabilization step is about 20 seconds +just gives you time to get the chamber + + align:start position:0% +just gives you time to get the chamber + + + align:start position:0% +just gives you time to get the chamber +get the old gases purged out from the uh + + align:start position:0% +get the old gases purged out from the uh + + + align:start position:0% +get the old gases purged out from the uh +prior Edge which was um the Breakthrough + + align:start position:0% +prior Edge which was um the Breakthrough + + + align:start position:0% +prior Edge which was um the Breakthrough +Edge and get the new ones purged in and + + align:start position:0% +Edge and get the new ones purged in and + + + align:start position:0% +Edge and get the new ones purged in and +establish your pressure of 10 millor + + align:start position:0% +establish your pressure of 10 millor + + + align:start position:0% +establish your pressure of 10 millor +then you actually do the main Edge so + + align:start position:0% +then you actually do the main Edge so + + + align:start position:0% +then you actually do the main Edge so +here you turn the Plasma on by turning + + align:start position:0% +here you turn the Plasma on by turning + + + align:start position:0% +here you turn the Plasma on by turning +the power onto the top and bottom + + align:start position:0% +the power onto the top and bottom + + + align:start position:0% +the power onto the top and bottom +electrodes so the plasma is now lit and + + align:start position:0% +electrodes so the plasma is now lit and + + + align:start position:0% +electrodes so the plasma is now lit and +you're actually etching here for a time + + align:start position:0% +you're actually etching here for a time + + + align:start position:0% +you're actually etching here for a time +of in this particular example 60 seconds + + align:start position:0% +of in this particular example 60 seconds + + + align:start position:0% +of in this particular example 60 seconds +You etge by time so it's a 60c etch uh + + align:start position:0% +You etge by time so it's a 60c etch uh + + + align:start position:0% +You etge by time so it's a 60c etch uh +and then you move to the last + + align:start position:0% +and then you move to the last + + + align:start position:0% +and then you move to the last +stabilization now and and you're + + align:start position:0% +stabilization now and and you're + + + align:start position:0% +stabilization now and and you're +stabilizing to get ready for What's + + align:start position:0% +stabilizing to get ready for What's + + + align:start position:0% +stabilizing to get ready for What's +called the overetch so there's a + + align:start position:0% +called the overetch so there's a + + + align:start position:0% +called the overetch so there's a +breakthrough edch to get through the + + align:start position:0% +breakthrough edch to get through the + + + align:start position:0% +breakthrough edch to get through the +native oxide there's a main edch which + + align:start position:0% +native oxide there's a main edch which + + + align:start position:0% +native oxide there's a main edch which +does most the work now the over etch is + + align:start position:0% +does most the work now the over etch is + + + align:start position:0% +does most the work now the over etch is +the amount of time you need remember + + align:start position:0% +the amount of time you need remember + + + align:start position:0% +the amount of time you need remember +where you pretty much hit the bottom but + + align:start position:0% +where you pretty much hit the bottom but + + + align:start position:0% +where you pretty much hit the bottom but +you may have stringers or other things + + align:start position:0% +you may have stringers or other things + + + align:start position:0% +you may have stringers or other things +uh so the over typically has to have + + align:start position:0% +uh so the over typically has to have + + + align:start position:0% +uh so the over typically has to have +even greater selectivity than the main + + align:start position:0% +even greater selectivity than the main + + + align:start position:0% +even greater selectivity than the main +edch and so the overetch in this example + + align:start position:0% +edch and so the overetch in this example + + + align:start position:0% +edch and so the overetch in this example +you notice they remove the chlorine so + + align:start position:0% +you notice they remove the chlorine so + + + align:start position:0% +you notice they remove the chlorine so +the chlorine flow which was 40 CCM has + + align:start position:0% +the chlorine flow which was 40 CCM has + + + align:start position:0% +the chlorine flow which was 40 CCM has +been removed and you just have hbr and + + align:start position:0% +been removed and you just have hbr and + + + align:start position:0% +been removed and you just have hbr and +O2 this gives you a much higher + + align:start position:0% +O2 this gives you a much higher + + + align:start position:0% +O2 this gives you a much higher +selectivity maybe not as good of an etch + + align:start position:0% +selectivity maybe not as good of an etch + + + align:start position:0% +selectivity maybe not as good of an etch +rate uh but it does have very high + + align:start position:0% +rate uh but it does have very high + + + align:start position:0% +rate uh but it does have very high +selectivity um so that you will not + + align:start position:0% +selectivity um so that you will not + + + align:start position:0% +selectivity um so that you will not +break through that oxide and then you do + + align:start position:0% +break through that oxide and then you do + + + align:start position:0% +break through that oxide and then you do +the over Etch in this step where you + + align:start position:0% +the over Etch in this step where you + + + align:start position:0% +the over Etch in this step where you +light the plasma for 30 seconds uh using + + align:start position:0% +light the plasma for 30 seconds uh using + + + align:start position:0% +light the plasma for 30 seconds uh using +just a mixture of hbr and + + align:start position:0% +just a mixture of hbr and + + + align:start position:0% +just a mixture of hbr and +O2 you then unclamp the wafer the plasma + + align:start position:0% +O2 you then unclamp the wafer the plasma + + + align:start position:0% +O2 you then unclamp the wafer the plasma +goes off after those 30 seconds you + + align:start position:0% +goes off after those 30 seconds you + + + align:start position:0% +goes off after those 30 seconds you +unclamp the wafer and then you end and + + align:start position:0% +unclamp the wafer and then you end and + + + align:start position:0% +unclamp the wafer and then you end and +you're ready to + + align:start position:0% +you're ready to + + + align:start position:0% +you're ready to +unload so you know it's it's all + + align:start position:0% +unload so you know it's it's all + + + align:start position:0% +unload so you know it's it's all +computer controlled um you have in this + + align:start position:0% +computer controlled um you have in this + + + align:start position:0% +computer controlled um you have in this +example of just etching poly silic you + + align:start position:0% +example of just etching poly silic you + + + align:start position:0% +example of just etching poly silic you +have three types of etches a + + align:start position:0% +have three types of etches a + + + align:start position:0% +have three types of etches a +breakthrough a man and an over etch have + + align:start position:0% +breakthrough a man and an over etch have + + + align:start position:0% +breakthrough a man and an over etch have +stabilization steps in between uh and uh + + align:start position:0% +stabilization steps in between uh and uh + + + align:start position:0% +stabilization steps in between uh and uh +this this is an example and then you + + align:start position:0% +this this is an example and then you + + + align:start position:0% +this this is an example and then you +come out and you look at your etch rate + + align:start position:0% +come out and you look at your etch rate + + + align:start position:0% +come out and you look at your etch rate +and your sidewall profile and you see + + align:start position:0% +and your sidewall profile and you see + + + align:start position:0% +and your sidewall profile and you see +how it looks most etches as we said end + + align:start position:0% +how it looks most etches as we said end + + + align:start position:0% +how it looks most etches as we said end +up leaving a sidewall polymer that's + + align:start position:0% +up leaving a sidewall polymer that's + + + align:start position:0% +up leaving a sidewall polymer that's +either um like a hydrocarbon based or it + + align:start position:0% +either um like a hydrocarbon based or it + + + align:start position:0% +either um like a hydrocarbon based or it +might be a glass based like an oxide + + align:start position:0% +might be a glass based like an oxide + + + align:start position:0% +might be a glass based like an oxide +like based material that is what's + + align:start position:0% +like based material that is what's + + + align:start position:0% +like based material that is what's +responsible remember it's the inhibitor + + align:start position:0% +responsible remember it's the inhibitor + + + align:start position:0% +responsible remember it's the inhibitor +layer that keeps you from etching + + align:start position:0% +layer that keeps you from etching + + + align:start position:0% +layer that keeps you from etching +sideways that's what gives you such + + align:start position:0% +sideways that's what gives you such + + + align:start position:0% +sideways that's what gives you such +perfectly vertical side walls you must + + align:start position:0% +perfectly vertical side walls you must + + + align:start position:0% +perfectly vertical side walls you must +have that inhibitor layer the question + + align:start position:0% +have that inhibitor layer the question + + + align:start position:0% +have that inhibitor layer the question +is what do you do with that inhibitor + + align:start position:0% +is what do you do with that inhibitor + + + align:start position:0% +is what do you do with that inhibitor +layer now that it's on your wafer every + + align:start position:0% +layer now that it's on your wafer every + + + align:start position:0% +layer now that it's on your wafer every +single gate has some goop whatever it + + align:start position:0% +single gate has some goop whatever it + + + align:start position:0% +single gate has some goop whatever it +might be sidewall junk uh polymer + + align:start position:0% +might be sidewall junk uh polymer + + + align:start position:0% +might be sidewall junk uh polymer +whatever you want to call it you need to + + align:start position:0% +whatever you want to call it you need to + + + align:start position:0% +whatever you want to call it you need to +do a post Ed cleanup process after that + + align:start position:0% +do a post Ed cleanup process after that + + + align:start position:0% +do a post Ed cleanup process after that +because that inhibitor layer is there uh + + align:start position:0% +because that inhibitor layer is there uh + + + align:start position:0% +because that inhibitor layer is there uh +if you go into a Tem or something you + + align:start position:0% +if you go into a Tem or something you + + + align:start position:0% +if you go into a Tem or something you +can see it what you'll see is or maybe + + align:start position:0% +can see it what you'll see is or maybe + + + align:start position:0% +can see it what you'll see is or maybe +even in an SCM you'll see your + + align:start position:0% +even in an SCM you'll see your + + + align:start position:0% +even in an SCM you'll see your +polysilicon gate and you'll see some + + align:start position:0% +polysilicon gate and you'll see some + + + align:start position:0% +polysilicon gate and you'll see some +material maybe that looks like this some + + align:start position:0% +material maybe that looks like this some + + + align:start position:0% +material maybe that looks like this some +maybe amorphous looking material very + + align:start position:0% +maybe amorphous looking material very + + + align:start position:0% +maybe amorphous looking material very +thin it might only be uh 20 angstroms + + align:start position:0% +thin it might only be uh 20 angstroms + + + align:start position:0% +thin it might only be uh 20 angstroms +something like that it's very thin + + align:start position:0% +something like that it's very thin + + + align:start position:0% +something like that it's very thin +thickness may vary from top to bottom + + align:start position:0% +thickness may vary from top to bottom + + + align:start position:0% +thickness may vary from top to bottom +whatever but that's that's an inhibitor + + align:start position:0% +whatever but that's that's an inhibitor + + + align:start position:0% +whatever but that's that's an inhibitor +layer um that is what gave you that + + align:start position:0% +layer um that is what gave you that + + + align:start position:0% +layer um that is what gave you that +sidewall but typically it's removed by + + align:start position:0% +sidewall but typically it's removed by + + + align:start position:0% +sidewall but typically it's removed by +either an HF dip or HF combined with + + align:start position:0% +either an HF dip or HF combined with + + + align:start position:0% +either an HF dip or HF combined with +piranha + + align:start position:0% +piranha + + + align:start position:0% +piranha +if it's um some kind of hydrocarbon you + + align:start position:0% +if it's um some kind of hydrocarbon you + + + align:start position:0% +if it's um some kind of hydrocarbon you +need the extra piranha uh these are + + align:start position:0% +need the extra piranha uh these are + + + align:start position:0% +need the extra piranha uh these are +typically not things you want to leave + + align:start position:0% +typically not things you want to leave + + + align:start position:0% +typically not things you want to leave +on there they can introduce contaminants + + align:start position:0% +on there they can introduce contaminants + + + align:start position:0% +on there they can introduce contaminants +in in subsequent + + align:start position:0% +in in subsequent + + + align:start position:0% +in in subsequent +steps so you have to do a cleanup + + align:start position:0% +steps so you have to do a cleanup + + + align:start position:0% +steps so you have to do a cleanup +process okay so that's just an example + + align:start position:0% +process okay so that's just an example + + + align:start position:0% +process okay so that's just an example +of using a dedicated gate etcher of how + + align:start position:0% +of using a dedicated gate etcher of how + + + align:start position:0% +of using a dedicated gate etcher of how +you would etch a polysilicon gate um + + align:start position:0% +you would etch a polysilicon gate um + + + align:start position:0% +you would etch a polysilicon gate um +let's just talk about a couple of the + + align:start position:0% +let's just talk about a couple of the + + + align:start position:0% +let's just talk about a couple of the +characteristics people often see and if + + align:start position:0% +characteristics people often see and if + + + align:start position:0% +characteristics people often see and if +you do gate itching this is what you + + align:start position:0% +you do gate itching this is what you + + + align:start position:0% +you do gate itching this is what you +will be up against um here's an example + + align:start position:0% +will be up against um here's an example + + + align:start position:0% +will be up against um here's an example +of what's called notching at the bottom + + align:start position:0% +of what's called notching at the bottom + + + align:start position:0% +of what's called notching at the bottom +of the polysilicon gate it's probably a + + align:start position:0% +of the polysilicon gate it's probably a + + + align:start position:0% +of the polysilicon gate it's probably a +little bit hard to see this is not the + + align:start position:0% +little bit hard to see this is not the + + + align:start position:0% +little bit hard to see this is not the +greatest micrograph these are SCM + + align:start position:0% +greatest micrograph these are SCM + + + align:start position:0% +greatest micrograph these are SCM +cross-sections these line widths from + + align:start position:0% +cross-sections these line widths from + + + align:start position:0% +cross-sections these line widths from +here to here is Nally 02 microns from + + align:start position:0% +here to here is Nally 02 microns from + + + align:start position:0% +here to here is Nally 02 microns from +this point to that point so it's a + + align:start position:0% +this point to that point so it's a + + + align:start position:0% +this point to that point so it's a +polysilicon uh line uh and this is using + + align:start position:0% +polysilicon uh line uh and this is using + + + align:start position:0% +polysilicon uh line uh and this is using +a sort of a standard flow rate and + + align:start position:0% +a sort of a standard flow rate and + + + align:start position:0% +a sort of a standard flow rate and +here's where they modified the flow rate + + align:start position:0% +here's where they modified the flow rate + + + align:start position:0% +here's where they modified the flow rate +making a little bit higher and if you + + align:start position:0% +making a little bit higher and if you + + + align:start position:0% +making a little bit higher and if you +notice the the gate looks sort of + + align:start position:0% +notice the the gate looks sort of + + + align:start position:0% +notice the the gate looks sort of +straight and then it goes down it kind + + align:start position:0% +straight and then it goes down it kind + + + align:start position:0% +straight and then it goes down it kind +of goes in at the bottom like a little + + align:start position:0% +of goes in at the bottom like a little + + + align:start position:0% +of goes in at the bottom like a little +Notch um this is considered to be + + align:start position:0% +Notch um this is considered to be + + + align:start position:0% +Notch um this is considered to be +undesirable in in many cases you + + align:start position:0% +undesirable in in many cases you + + + align:start position:0% +undesirable in in many cases you +typically want the gate sidewall to go + + align:start position:0% +typically want the gate sidewall to go + + + align:start position:0% +typically want the gate sidewall to go +straight + + align:start position:0% +straight + + + align:start position:0% +straight +down why would you not want the gate to + + align:start position:0% +down why would you not want the gate to + + + align:start position:0% +down why would you not want the gate to +be notched um well there's some examples + + align:start position:0% +be notched um well there's some examples + + + align:start position:0% +be notched um well there's some examples +uh of what it might do let's say your + + align:start position:0% +uh of what it might do let's say your + + + align:start position:0% +uh of what it might do let's say your +gate did go in like this so you have it + + align:start position:0% +gate did go in like this so you have it + + + align:start position:0% +gate did go in like this so you have it +vertical and then it kind of I'm going + + align:start position:0% +vertical and then it kind of I'm going + + + align:start position:0% +vertical and then it kind of I'm going +to make it worse I'll make the notch + + align:start position:0% +to make it worse I'll make the notch + + + align:start position:0% +to make it worse I'll make the notch +look really bad so um it might look like + + align:start position:0% +look really bad so um it might look like + + + align:start position:0% +look really bad so um it might look like +that down here and something like that + + align:start position:0% +that down here and something like that + + + align:start position:0% +that down here and something like that +well the problem with notching like that + + align:start position:0% +well the problem with notching like that + + + align:start position:0% +well the problem with notching like that +is uh when you go to do your iron + + align:start position:0% +is uh when you go to do your iron + + + align:start position:0% +is uh when you go to do your iron +implant depending on what angle I'm + + align:start position:0% +implant depending on what angle I'm + + + align:start position:0% +implant depending on what angle I'm +going to implant the source and drain + + align:start position:0% +going to implant the source and drain + + + align:start position:0% +going to implant the source and drain +depending on what angle and how bad the + + align:start position:0% +depending on what angle and how bad the + + + align:start position:0% +depending on what angle and how bad the +um the uh notching is your IR implant + + align:start position:0% +um the uh notching is your IR implant + + + align:start position:0% +um the uh notching is your IR implant +might end up looking like + + align:start position:0% +might end up looking like + + + align:start position:0% +might end up looking like +this so there might be a little region + + align:start position:0% +this so there might be a little region + + + align:start position:0% +this so there might be a little region +on either side where you don't get the + + align:start position:0% +on either side where you don't get the + + + align:start position:0% +on either side where you don't get the +source and drain extensions don't + + align:start position:0% +source and drain extensions don't + + + align:start position:0% +source and drain extensions don't +actually get implanted and where there's + + align:start position:0% +actually get implanted and where there's + + + align:start position:0% +actually get implanted and where there's +no gate okay now you say well I just do + + align:start position:0% +no gate okay now you say well I just do + + + align:start position:0% +no gate okay now you say well I just do +a high enough temperature anal and then + + align:start position:0% +a high enough temperature anal and then + + + align:start position:0% +a high enough temperature anal and then +this arsenic will move right it'll will + + align:start position:0% +this arsenic will move right it'll will + + + align:start position:0% +this arsenic will move right it'll will +probably overlap you'll probably be okay + + align:start position:0% +probably overlap you'll probably be okay + + + align:start position:0% +probably overlap you'll probably be okay +but what if it doesn't you can't go un + + align:start position:0% +but what if it doesn't you can't go un + + + align:start position:0% +but what if it doesn't you can't go un +probably uh and and if that Notch is not + + align:start position:0% +probably uh and and if that Notch is not + + + align:start position:0% +probably uh and and if that Notch is not +well controlled um you can end up with + + align:start position:0% +well controlled um you can end up with + + + align:start position:0% +well controlled um you can end up with +you know all kinds of High series + + align:start position:0% +you know all kinds of High series + + + align:start position:0% +you know all kinds of High series +resistance in that region so people + + align:start position:0% +resistance in that region so people + + + align:start position:0% +resistance in that region so people +typically don't want to notch because it + + align:start position:0% +typically don't want to notch because it + + + align:start position:0% +typically don't want to notch because it +ends up affecting what happens to the + + align:start position:0% +ends up affecting what happens to the + + + align:start position:0% +ends up affecting what happens to the +iron implant because remember this poly + + align:start position:0% +iron implant because remember this poly + + + align:start position:0% +iron implant because remember this poly +that you're forming this gate is the + + align:start position:0% +that you're forming this gate is the + + + align:start position:0% +that you're forming this gate is the +mask for your next step which is going + + align:start position:0% +mask for your next step which is going + + + align:start position:0% +mask for your next step which is going +to be implant the source and drain + + align:start position:0% +to be implant the source and drain + + + align:start position:0% +to be implant the source and drain +extensions um so this is an example of + + align:start position:0% +extensions um so this is an example of + + + align:start position:0% +extensions um so this is an example of +how they got rid of the notch this Notch + + align:start position:0% +how they got rid of the notch this Notch + + + align:start position:0% +how they got rid of the notch this Notch +is not as bad or doesn't look as + + align:start position:0% +is not as bad or doesn't look as + + + align:start position:0% +is not as bad or doesn't look as +dramatic as the one I drew on the board + + align:start position:0% +dramatic as the one I drew on the board + + + align:start position:0% +dramatic as the one I drew on the board +uh they got rid of it by just changing + + align:start position:0% +uh they got rid of it by just changing + + + align:start position:0% +uh they got rid of it by just changing +um a few things they Chang the pressure + + align:start position:0% +um a few things they Chang the pressure + + + align:start position:0% +um a few things they Chang the pressure +and the flow rate and they're able to + + align:start position:0% +and the flow rate and they're able to + + + align:start position:0% +and the flow rate and they're able to +get a more vertical type of sidewall so + + align:start position:0% +get a more vertical type of sidewall so + + + align:start position:0% +get a more vertical type of sidewall so +if you have to do poly silken Gates you + + align:start position:0% +if you have to do poly silken Gates you + + + align:start position:0% +if you have to do poly silken Gates you +find yourself twiddling a lot of the + + align:start position:0% +find yourself twiddling a lot of the + + + align:start position:0% +find yourself twiddling a lot of the +knobs the pressures the flow rates and + + align:start position:0% +knobs the pressures the flow rates and + + + align:start position:0% +knobs the pressures the flow rates and +things like that until you get a shape + + align:start position:0% +things like that until you get a shape + + + align:start position:0% +things like that until you get a shape +um that you're happy + + align:start position:0% + + + + align:start position:0% + +with uh this is another here on slide 12 + + align:start position:0% +with uh this is another here on slide 12 + + + align:start position:0% +with uh this is another here on slide 12 +is another article I took out of + + align:start position:0% +is another article I took out of + + + align:start position:0% +is another article I took out of +literature uh it's an older paper it's + + align:start position:0% +literature uh it's an older paper it's + + + align:start position:0% +literature uh it's an older paper it's +from applied physics letterers + + align:start position:0% +from applied physics letterers + + + align:start position:0% +from applied physics letterers +and uh what they're making uh a point + + align:start position:0% +and uh what they're making uh a point + + + align:start position:0% +and uh what they're making uh a point +here has to do with something called gas + + align:start position:0% +here has to do with something called gas + + + align:start position:0% +here has to do with something called gas +resonance time in the plasma eter uh + + align:start position:0% +resonance time in the plasma eter uh + + + align:start position:0% +resonance time in the plasma eter uh +this resonance time um concept is also + + align:start position:0% +this resonance time um concept is also + + + align:start position:0% +this resonance time um concept is also +important if you're if you're growing th + + align:start position:0% +important if you're if you're growing th + + + align:start position:0% +important if you're if you're growing th +films uh so it also is important in + + align:start position:0% +films uh so it also is important in + + + align:start position:0% +films uh so it also is important in +reactors and things what it what it is + + align:start position:0% +reactors and things what it what it is + + + align:start position:0% +reactors and things what it what it is +has to do is sort of the amount of time + + align:start position:0% +has to do is sort of the amount of time + + + align:start position:0% +has to do is sort of the amount of time +here in seconds or fraction of a second + + align:start position:0% +here in seconds or fraction of a second + + + align:start position:0% +here in seconds or fraction of a second +effectively that that gas a volume of + + align:start position:0% +effectively that that gas a volume of + + + align:start position:0% +effectively that that gas a volume of +gas is is occupies uh the um the plasma + + align:start position:0% +gas is is occupies uh the um the plasma + + + align:start position:0% +gas is is occupies uh the um the plasma +etcher itself so and you you can see + + align:start position:0% +etcher itself so and you you can see + + + align:start position:0% +etcher itself so and you you can see +that resonance time increases so it goes + + align:start position:0% +that resonance time increases so it goes + + + align:start position:0% +that resonance time increases so it goes +up uh with each one of these lines as I + + align:start position:0% +up uh with each one of these lines as I + + + align:start position:0% +up uh with each one of these lines as I +go to higher and higher pressure or it + + align:start position:0% +go to higher and higher pressure or it + + + align:start position:0% +go to higher and higher pressure or it +decreases as I go to lower flows um and + + align:start position:0% +decreases as I go to lower flows um and + + + align:start position:0% +decreases as I go to lower flows um and +um as I go to lower pressures and um as + + align:start position:0% +um as I go to lower pressures and um as + + + align:start position:0% +um as I go to lower pressures and um as +I increase uh the flow rate it goes down + + align:start position:0% +I increase uh the flow rate it goes down + + + align:start position:0% +I increase uh the flow rate it goes down +so you're flowing through faster now why + + align:start position:0% +so you're flowing through faster now why + + + align:start position:0% +so you're flowing through faster now why +would we care about the gas resonance + + align:start position:0% +would we care about the gas resonance + + + align:start position:0% +would we care about the gas resonance +time well we do care about it because + + align:start position:0% +time well we do care about it because + + + align:start position:0% +time well we do care about it because +the amount of time the gas the fresh gas + + align:start position:0% +the amount of time the gas the fresh gas + + + align:start position:0% +the amount of time the gas the fresh gas +is sort of Resident has to do with the + + align:start position:0% +is sort of Resident has to do with the + + + align:start position:0% +is sort of Resident has to do with the +amount of time the gas is available to + + align:start position:0% +amount of time the gas is available to + + + align:start position:0% +amount of time the gas is available to +actually do etching um and if you if you + + align:start position:0% +actually do etching um and if you if you + + + align:start position:0% +actually do etching um and if you if you +have a very long resonance time uh + + align:start position:0% +have a very long resonance time uh + + + align:start position:0% +have a very long resonance time uh +byproducts can develop you know actually + + align:start position:0% +byproducts can develop you know actually + + + align:start position:0% +byproducts can develop you know actually +after all these etch reactions are + + align:start position:0% +after all these etch reactions are + + + align:start position:0% +after all these etch reactions are +chemical reactions they they evolve + + align:start position:0% +chemical reactions they they evolve + + + align:start position:0% +chemical reactions they they evolve +byproducts those byproducts can then sit + + align:start position:0% +byproducts those byproducts can then sit + + + align:start position:0% +byproducts those byproducts can then sit +and develop there for period of + + align:start position:0% +and develop there for period of + + + align:start position:0% +and develop there for period of +fractions of a second and those + + align:start position:0% +fractions of a second and those + + + align:start position:0% +fractions of a second and those +byproducts can then end up affecting the + + align:start position:0% +byproducts can then end up affecting the + + + align:start position:0% +byproducts can then end up affecting the +etch or the sidewall polymer formation + + align:start position:0% +etch or the sidewall polymer formation + + + align:start position:0% +etch or the sidewall polymer formation +or things like that so resonance time is + + align:start position:0% +or things like that so resonance time is + + + align:start position:0% +or things like that so resonance time is +ends up being an important parameter the + + align:start position:0% +ends up being an important parameter the + + + align:start position:0% +ends up being an important parameter the +way people control it as well they + + align:start position:0% +way people control it as well they + + + align:start position:0% +way people control it as well they +either up the flow rate the total gas + + align:start position:0% +either up the flow rate the total gas + + + align:start position:0% +either up the flow rate the total gas +flow rate or they change the pressure in + + align:start position:0% +flow rate or they change the pressure in + + + align:start position:0% +flow rate or they change the pressure in +some ways um uh in in the + + align:start position:0% + + + + align:start position:0% + +tool here's just an example from that + + align:start position:0% +tool here's just an example from that + + + align:start position:0% +tool here's just an example from that +same paper on an example of what happens + + align:start position:0% +same paper on an example of what happens + + + align:start position:0% +same paper on an example of what happens +as a function of the Silicon Edge rate + + align:start position:0% +as a function of the Silicon Edge rate + + + align:start position:0% +as a function of the Silicon Edge rate +as a function of uh a flow rate so + + align:start position:0% +as a function of uh a flow rate so + + + align:start position:0% +as a function of uh a flow rate so +here's um etch rate in nanometers per + + align:start position:0% +here's um etch rate in nanometers per + + + align:start position:0% +here's um etch rate in nanometers per +minute and uh this is a particular um + + align:start position:0% +minute and uh this is a particular um + + + align:start position:0% +minute and uh this is a particular um +silicon etch what they're using is + + align:start position:0% +silicon etch what they're using is + + + align:start position:0% +silicon etch what they're using is +chlorine very common um and this was the + + align:start position:0% +chlorine very common um and this was the + + + align:start position:0% +chlorine very common um and this was the +so so-called their present etching + + align:start position:0% +so so-called their present etching + + + align:start position:0% +so so-called their present etching +technique uh when when they had um uh + + align:start position:0% +technique uh when when they had um uh + + + align:start position:0% +technique uh when when they had um uh +using a high gas flow rate uh and a + + align:start position:0% +using a high gas flow rate uh and a + + + align:start position:0% +using a high gas flow rate uh and a +conventional etching technique so it + + align:start position:0% +conventional etching technique so it + + + align:start position:0% +conventional etching technique so it +also when you change the resonance time + + align:start position:0% +also when you change the resonance time + + + align:start position:0% +also when you change the resonance time +uh increasing it uh is going to uh uh + + align:start position:0% +uh increasing it uh is going to uh uh + + + align:start position:0% +uh increasing it uh is going to uh uh +change the um the etch rate so in this + + align:start position:0% +change the um the etch rate so in this + + + align:start position:0% +change the um the etch rate so in this +case a shorter gas residence time + + align:start position:0% +case a shorter gas residence time + + + align:start position:0% +case a shorter gas residence time +increases the um Edge rate so they incre + + align:start position:0% +increases the um Edge rate so they incre + + + align:start position:0% +increases the um Edge rate so they incre +I'm sorry increase the flow means the uh + + align:start position:0% +I'm sorry increase the flow means the uh + + + align:start position:0% +I'm sorry increase the flow means the uh +the amount of time any any volume of + + align:start position:0% +the amount of time any any volume of + + + align:start position:0% +the amount of time any any volume of +gases in the reactor is is shorter and + + align:start position:0% +gases in the reactor is is shorter and + + + align:start position:0% +gases in the reactor is is shorter and +why because it increases availability of + + align:start position:0% +why because it increases availability of + + + align:start position:0% +why because it increases availability of +neutral etent speed species you have the + + align:start position:0% +neutral etent speed species you have the + + + align:start position:0% +neutral etent speed species you have the +unreacted ENT coming in + + align:start position:0% +unreacted ENT coming in + + + align:start position:0% +unreacted ENT coming in +faster and it helps and it also reduces + + align:start position:0% +faster and it helps and it also reduces + + + align:start position:0% +faster and it helps and it also reduces +the concentration of this the reaction + + align:start position:0% +the concentration of this the reaction + + + align:start position:0% +the concentration of this the reaction +byproducts because again these are all + + align:start position:0% +byproducts because again these are all + + + align:start position:0% +byproducts because again these are all +chemical reactions if you want a + + align:start position:0% +chemical reactions if you want a + + + align:start position:0% +chemical reactions if you want a +reaction for a chemical reactant to go + + align:start position:0% +reaction for a chemical reactant to go + + + align:start position:0% +reaction for a chemical reactant to go +faster you put in the reactants faster + + align:start position:0% +faster you put in the reactants faster + + + align:start position:0% +faster you put in the reactants faster +and you remove the B products um rapidly + + align:start position:0% +and you remove the B products um rapidly + + + align:start position:0% +and you remove the B products um rapidly +as + + align:start position:0% +as + + + align:start position:0% +as +well so not only does it affect etch + + align:start position:0% +well so not only does it affect etch + + + align:start position:0% +well so not only does it affect etch +rate but changing things like pressure + + align:start position:0% +rate but changing things like pressure + + + align:start position:0% +rate but changing things like pressure +also affect um the shape of what you get + + align:start position:0% +also affect um the shape of what you get + + + align:start position:0% +also affect um the shape of what you get +here's an example on uh slide 14 uh from + + align:start position:0% +here's an example on uh slide 14 uh from + + + align:start position:0% +here's an example on uh slide 14 uh from +that same article of three different + + align:start position:0% +that same article of three different + + + align:start position:0% +that same article of three different +pressures um here we're at t tour um to + + align:start position:0% +pressures um here we're at t tour um to + + + align:start position:0% +pressures um here we're at t tour um to +try to define a polysilicon gate uh one + + align:start position:0% +try to define a polysilicon gate uh one + + + align:start position:0% +try to define a polysilicon gate uh one +I'm sorry 10 millor one millor and 0.1 + + align:start position:0% +I'm sorry 10 millor one millor and 0.1 + + + align:start position:0% +I'm sorry 10 millor one millor and 0.1 +so we're going down here each Case by + + align:start position:0% +so we're going down here each Case by + + + align:start position:0% +so we're going down here each Case by +order of magnitude and pressure um we're + + align:start position:0% +order of magnitude and pressure um we're + + + align:start position:0% +order of magnitude and pressure um we're +using lower pressure at high flows you + + align:start position:0% +using lower pressure at high flows you + + + align:start position:0% +using lower pressure at high flows you +notice we get more anisotropic etching + + align:start position:0% +notice we get more anisotropic etching + + + align:start position:0% +notice we get more anisotropic etching +and less notching at least when using + + align:start position:0% +and less notching at least when using + + + align:start position:0% +and less notching at least when using +this particular uh chlorine polycylic so + + align:start position:0% +this particular uh chlorine polycylic so + + + align:start position:0% +this particular uh chlorine polycylic so +here at 10 + + align:start position:0% +here at 10 + + + align:start position:0% +here at 10 +millor um and you get a a fairly um + + align:start position:0% +millor um and you get a a fairly um + + + align:start position:0% +millor um and you get a a fairly um +isotropic atch it's not totally + + align:start position:0% +isotropic atch it's not totally + + + align:start position:0% +isotropic atch it's not totally +isotropic but you notice it's etching + + align:start position:0% +isotropic but you notice it's etching + + + align:start position:0% +isotropic but you notice it's etching +sideways as well as vertically and how + + align:start position:0% +sideways as well as vertically and how + + + align:start position:0% +sideways as well as vertically and how +can I tell because this is my photo + + align:start position:0% +can I tell because this is my photo + + + align:start position:0% +can I tell because this is my photo +resist and it's undercut on the left and + + align:start position:0% +resist and it's undercut on the left and + + + align:start position:0% +resist and it's undercut on the left and +right side so the line is a lot narrower + + align:start position:0% +right side so the line is a lot narrower + + + align:start position:0% +right side so the line is a lot narrower +than what had been + + align:start position:0% +than what had been + + + align:start position:0% +than what had been +designed there's a little bit uh better + + align:start position:0% +designed there's a little bit uh better + + + align:start position:0% +designed there's a little bit uh better +is an isotropy at a lower pressure at + + align:start position:0% +is an isotropy at a lower pressure at + + + align:start position:0% +is an isotropy at a lower pressure at +one notor but we still have now we've + + align:start position:0% +one notor but we still have now we've + + + align:start position:0% +one notor but we still have now we've +developed a little Notch at the bottom + + align:start position:0% +developed a little Notch at the bottom + + + align:start position:0% +developed a little Notch at the bottom +which isn't again that's not considered + + align:start position:0% +which isn't again that's not considered + + + align:start position:0% +which isn't again that's not considered +to be good good finally we have um the + + align:start position:0% +to be good good finally we have um the + + + align:start position:0% +to be good good finally we have um the +lowest resonance time or the lowest + + align:start position:0% +lowest resonance time or the lowest + + + align:start position:0% +lowest resonance time or the lowest +pressure here at at 0.1 millor this uh + + align:start position:0% +pressure here at at 0.1 millor this uh + + + align:start position:0% +pressure here at at 0.1 millor this uh +paper demonstrates very vertical + + align:start position:0% +paper demonstrates very vertical + + + align:start position:0% +paper demonstrates very vertical +sidewalls and no undercutting so this is + + align:start position:0% +sidewalls and no undercutting so this is + + + align:start position:0% +sidewalls and no undercutting so this is +a reasonable uh would be a very + + align:start position:0% +a reasonable uh would be a very + + + align:start position:0% +a reasonable uh would be a very +considered a very good quality Edge you + + align:start position:0% +considered a very good quality Edge you + + + align:start position:0% +considered a very good quality Edge you +may be able to make one device with this + + align:start position:0% +may be able to make one device with this + + + align:start position:0% +may be able to make one device with this +Edge I'm not saying this Edge won't work + + align:start position:0% +Edge I'm not saying this Edge won't work + + + align:start position:0% +Edge I'm not saying this Edge won't work +but from a manufacturing point of view + + align:start position:0% +but from a manufacturing point of view + + + align:start position:0% +but from a manufacturing point of view +how do I control how do I control my + + align:start position:0% +how do I control how do I control my + + + align:start position:0% +how do I control how do I control my +line withd on my critical Dimension it's + + align:start position:0% +line withd on my critical Dimension it's + + + align:start position:0% +line withd on my critical Dimension it's +not well controlled at all um so this + + align:start position:0% +not well controlled at all um so this + + + align:start position:0% +not well controlled at all um so this +would not be considered a manufacturable + + align:start position:0% +would not be considered a manufacturable + + + align:start position:0% +would not be considered a manufacturable +type + + align:start position:0% + + + + align:start position:0% + +process there's another consideration so + + align:start position:0% +process there's another consideration so + + + align:start position:0% +process there's another consideration so +we we talked a lot about uh we care + + align:start position:0% +we we talked a lot about uh we care + + + align:start position:0% +we we talked a lot about uh we care +about the etch rate and and the shape of + + align:start position:0% +about the etch rate and and the shape of + + + align:start position:0% +about the etch rate and and the shape of +the sidewall because that affects how + + align:start position:0% +the sidewall because that affects how + + + align:start position:0% +the sidewall because that affects how +we're going to implant it and do other + + align:start position:0% +we're going to implant it and do other + + + align:start position:0% +we're going to implant it and do other +things um a huge consideration anytime + + align:start position:0% +things um a huge consideration anytime + + + align:start position:0% +things um a huge consideration anytime +you are etching features this is not + + align:start position:0% +you are etching features this is not + + + align:start position:0% +you are etching features this is not +just true of a polysilicon gate but I'm + + align:start position:0% +just true of a polysilicon gate but I'm + + + align:start position:0% +just true of a polysilicon gate but I'm +giving the example for a polysilicon + + align:start position:0% +giving the example for a polysilicon + + + align:start position:0% +giving the example for a polysilicon +gate uh is uh so gate Ed as the example + + align:start position:0% +gate uh is uh so gate Ed as the example + + + align:start position:0% +gate uh is uh so gate Ed as the example +is the topography um and and so what + + align:start position:0% +is the topography um and and so what + + + align:start position:0% +is the topography um and and so what +what's the problem well highly + + align:start position:0% +what's the problem well highly + + + align:start position:0% +what's the problem well highly +anisotropic etching so etching that is + + align:start position:0% +anisotropic etching so etching that is + + + align:start position:0% +anisotropic etching so etching that is +only down only vertical doesn't etch + + align:start position:0% +only down only vertical doesn't etch + + + align:start position:0% +only down only vertical doesn't etch +sideways is required to achieve good + + align:start position:0% +sideways is required to achieve good + + + align:start position:0% +sideways is required to achieve good +control we just said that over the gate + + align:start position:0% +control we just said that over the gate + + + align:start position:0% +control we just said that over the gate +length and the shape but um unless you + + align:start position:0% +length and the shape but um unless you + + + align:start position:0% +length and the shape but um unless you +have a long overetch uh that you do at + + align:start position:0% +have a long overetch uh that you do at + + + align:start position:0% +have a long overetch uh that you do at +the end of of a step you can get + + align:start position:0% +the end of of a step you can get + + + align:start position:0% +the end of of a step you can get +stringers left behind and let's just + + align:start position:0% +stringers left behind and let's just + + + align:start position:0% +stringers left behind and let's just +show um an example here so on the left + + align:start position:0% +show um an example here so on the left + + + align:start position:0% +show um an example here so on the left +I'm showing where we've etched through + + align:start position:0% +I'm showing where we've etched through + + + align:start position:0% +I'm showing where we've etched through +polysilicon there was no topog on the + + align:start position:0% +polysilicon there was no topog on the + + + align:start position:0% +polysilicon there was no topog on the +original part of the wafer it which is + + align:start position:0% +original part of the wafer it which is + + + align:start position:0% +original part of the wafer it which is +flat so I have photo resist and I Ed + + align:start position:0% +flat so I have photo resist and I Ed + + + align:start position:0% +flat so I have photo resist and I Ed +polyic and isotropically everything + + align:start position:0% +polyic and isotropically everything + + + align:start position:0% +polyic and isotropically everything +looks very good now what's happened on + + align:start position:0% +looks very good now what's happened on + + + align:start position:0% +looks very good now what's happened on +the right well on the right hand side I + + align:start position:0% +the right well on the right hand side I + + + align:start position:0% +the right well on the right hand side I +had some initial topography so I had a + + align:start position:0% +had some initial topography so I had a + + + align:start position:0% +had some initial topography so I had a +step that looks like this okay so as a + + align:start position:0% +step that looks like this okay so as a + + + align:start position:0% +step that looks like this okay so as a +result of having that step the + + align:start position:0% +result of having that step the + + + align:start position:0% +result of having that step the +polysilicon overlayer which is shown by + + align:start position:0% +polysilicon overlayer which is shown by + + + align:start position:0% +polysilicon overlayer which is shown by +this sort of stippled region the + + align:start position:0% +this sort of stippled region the + + + align:start position:0% +this sort of stippled region the +polysilicon went over everything okay so + + align:start position:0% +polysilicon went over everything okay so + + + align:start position:0% +polysilicon went over everything okay so +uh the polysilicon in this region is + + align:start position:0% +uh the polysilicon in this region is + + + align:start position:0% +uh the polysilicon in this region is +actually thicker than it is in the flat + + align:start position:0% +actually thicker than it is in the flat + + + align:start position:0% +actually thicker than it is in the flat +portion + + align:start position:0% +portion + + + align:start position:0% +portion +so by the time I clear the gate and I + + align:start position:0% +so by the time I clear the gate and I + + + align:start position:0% +so by the time I clear the gate and I +just hit this oxide right here I have + + align:start position:0% +just hit this oxide right here I have + + + align:start position:0% +just hit this oxide right here I have +left behind a Stringer because I haven't + + align:start position:0% +left behind a Stringer because I haven't + + + align:start position:0% +left behind a Stringer because I haven't +etched long enough because the poly + + align:start position:0% +etched long enough because the poly + + + align:start position:0% +etched long enough because the poly +silic thickness was thicker in this + + align:start position:0% +silic thickness was thicker in this + + + align:start position:0% +silic thickness was thicker in this +region and remember I'm only etching + + align:start position:0% +region and remember I'm only etching + + + align:start position:0% +region and remember I'm only etching +vertically it's not going sideways um so + + align:start position:0% +vertically it's not going sideways um so + + + align:start position:0% +vertically it's not going sideways um so +this Stringer is considered to be + + align:start position:0% +this Stringer is considered to be + + + align:start position:0% +this Stringer is considered to be +undesirable because it's now an extra + + align:start position:0% +undesirable because it's now an extra + + + align:start position:0% +undesirable because it's now an extra +gate electrode or it's an extra thing + + align:start position:0% +gate electrode or it's an extra thing + + + align:start position:0% +gate electrode or it's an extra thing +you didn't want in your circuit uh how + + align:start position:0% +you didn't want in your circuit uh how + + + align:start position:0% +you didn't want in your circuit uh how +do I get rid of it well you say just + + align:start position:0% +do I get rid of it well you say just + + + align:start position:0% +do I get rid of it well you say just +keep on itching keep the uh go to do an + + align:start position:0% +keep on itching keep the uh go to do an + + + align:start position:0% +keep on itching keep the uh go to do an +over etch so even though I I I finished + + align:start position:0% +over etch so even though I I I finished + + + align:start position:0% +over etch so even though I I I finished +etching the poly gate and I'm done in + + align:start position:0% +etching the poly gate and I'm done in + + + align:start position:0% +etching the poly gate and I'm done in +this region I'm not done over here so + + align:start position:0% +this region I'm not done over here so + + + align:start position:0% +this region I'm not done over here so +you keep it in and you keep banging on + + align:start position:0% +you keep it in and you keep banging on + + + align:start position:0% +you keep it in and you keep banging on +the top of that Stringer until it + + align:start position:0% +the top of that Stringer until it + + + align:start position:0% +the top of that Stringer until it +finally goes down to + + align:start position:0% +finally goes down to + + + align:start position:0% +finally goes down to +zero uh so you need a very long overed + + align:start position:0% +zero uh so you need a very long overed + + + align:start position:0% +zero uh so you need a very long overed +whenever you have um surface topography + + align:start position:0% +whenever you have um surface topography + + + align:start position:0% +whenever you have um surface topography +uh in order to get rid of stringers + + align:start position:0% +uh in order to get rid of stringers + + + align:start position:0% +uh in order to get rid of stringers +what's the disadvantage of a long over + + align:start position:0% +what's the disadvantage of a long over + + + align:start position:0% +what's the disadvantage of a long over +well you might break through your oxide + + align:start position:0% +well you might break through your oxide + + + align:start position:0% +well you might break through your oxide +because you're still beating on that + + align:start position:0% +because you're still beating on that + + + align:start position:0% +because you're still beating on that +oxide so unless you have really good + + align:start position:0% +oxide so unless you have really good + + + align:start position:0% +oxide so unless you have really good +selectivity as you're beating the + + align:start position:0% +selectivity as you're beating the + + + align:start position:0% +selectivity as you're beating the +Stringer down and getting rid of the + + align:start position:0% +Stringer down and getting rid of the + + + align:start position:0% +Stringer down and getting rid of the +Stringer you could be destroying the + + align:start position:0% +Stringer you could be destroying the + + + align:start position:0% +Stringer you could be destroying the +oxide what's the other bad thing well + + align:start position:0% +oxide what's the other bad thing well + + + align:start position:0% +oxide what's the other bad thing well +you're um your overetch may not be + + align:start position:0% +you're um your overetch may not be + + + align:start position:0% +you're um your overetch may not be +perfectly anisotropic it may be etching + + align:start position:0% +perfectly anisotropic it may be etching + + + align:start position:0% +perfectly anisotropic it may be etching +sideways a little bit on the gate so + + align:start position:0% +sideways a little bit on the gate so + + + align:start position:0% +sideways a little bit on the gate so +unless it's perfectly anisotropic you'll + + align:start position:0% +unless it's perfectly anisotropic you'll + + + align:start position:0% +unless it's perfectly anisotropic you'll +have that so there's always a balance uh + + align:start position:0% +have that so there's always a balance uh + + + align:start position:0% +have that so there's always a balance uh +with over it so this is why you will + + align:start position:0% +with over it so this is why you will + + + align:start position:0% +with over it so this is why you will +find people say if you want to get the + + align:start position:0% +find people say if you want to get the + + + align:start position:0% +find people say if you want to get the +finest patterns your wafer should be + + align:start position:0% +finest patterns your wafer should be + + + align:start position:0% +finest patterns your wafer should be +completely flat you should have no + + align:start position:0% +completely flat you should have no + + + align:start position:0% +completely flat you should have no +topography because if you have a + + align:start position:0% +topography because if you have a + + + align:start position:0% +topography because if you have a +completely flat wafer you never have to + + align:start position:0% +completely flat wafer you never have to + + + align:start position:0% +completely flat wafer you never have to +work about stringers you etch down you + + align:start position:0% +work about stringers you etch down you + + + align:start position:0% +work about stringers you etch down you +stop on the layer below and you stop + + align:start position:0% +stop on the layer below and you stop + + + align:start position:0% +stop on the layer below and you stop +period your over Etch in that case is + + align:start position:0% +period your over Etch in that case is + + + align:start position:0% +period your over Etch in that case is +only dictated by the non-uniformity in + + align:start position:0% +only dictated by the non-uniformity in + + + align:start position:0% +only dictated by the non-uniformity in +the film across the wafer as we talked + + align:start position:0% +the film across the wafer as we talked + + + align:start position:0% +the film across the wafer as we talked +about before non-uniformity etch rate + + align:start position:0% +about before non-uniformity etch rate + + + align:start position:0% +about before non-uniformity etch rate +now we have another requirement on + + align:start position:0% +now we have another requirement on + + + align:start position:0% +now we have another requirement on +overetch I have to not only take into + + align:start position:0% +overetch I have to not only take into + + + align:start position:0% +overetch I have to not only take into +account non-uniformity across the wafer + + align:start position:0% +account non-uniformity across the wafer + + + align:start position:0% +account non-uniformity across the wafer +but if I have topography and I have an + + align:start position:0% +but if I have topography and I have an + + + align:start position:0% +but if I have topography and I have an +anisotropic hch I have to get rid of + + align:start position:0% +anisotropic hch I have to get rid of + + + align:start position:0% +anisotropic hch I have to get rid of +stringers um so you will see the + + align:start position:0% +stringers um so you will see the + + + align:start position:0% +stringers um so you will see the +topography uh on Modern devices as they + + align:start position:0% +topography uh on Modern devices as they + + + align:start position:0% +topography uh on Modern devices as they +get smaller and smaller everything has + + align:start position:0% +get smaller and smaller everything has + + + align:start position:0% +get smaller and smaller everything has +to be smoother and smoother that's why + + align:start position:0% +to be smoother and smoother that's why + + + align:start position:0% +to be smoother and smoother that's why +people went away from Locos right Locos + + align:start position:0% +people went away from Locos right Locos + + + align:start position:0% +people went away from Locos right Locos +creates this big hump on the wafer + + align:start position:0% +creates this big hump on the wafer + + + align:start position:0% +creates this big hump on the wafer +people don't like that we do shallow + + align:start position:0% +people don't like that we do shallow + + + align:start position:0% +people don't like that we do shallow +trench which creates a perfectly flat + + align:start position:0% +trench which creates a perfectly flat + + + align:start position:0% +trench which creates a perfectly flat +wafer that way I can pattern a very very + + align:start position:0% +wafer that way I can pattern a very very + + + align:start position:0% +wafer that way I can pattern a very very +fine line and I don't have to worry + + align:start position:0% +fine line and I don't have to worry + + + align:start position:0% +fine line and I don't have to worry +about + + align:start position:0% + + + + align:start position:0% + +stringers uh slide 16 is is from a + + align:start position:0% +stringers uh slide 16 is is from a + + + align:start position:0% +stringers uh slide 16 is is from a +different text it has another example of + + align:start position:0% +different text it has another example of + + + align:start position:0% +different text it has another example of +stringer formation maybe this + + align:start position:0% +stringer formation maybe this + + + align:start position:0% +stringer formation maybe this +cross-section might be easier for you to + + align:start position:0% +cross-section might be easier for you to + + + align:start position:0% +cross-section might be easier for you to +see um so uh here's an example at where + + align:start position:0% +see um so uh here's an example at where + + + align:start position:0% +see um so uh here's an example at where +I have a field oxide so the field oxide + + align:start position:0% +I have a field oxide so the field oxide + + + align:start position:0% +I have a field oxide so the field oxide +has a certain step height to it shown + + align:start position:0% +has a certain step height to it shown + + + align:start position:0% +has a certain step height to it shown +here and I have and of course when you + + align:start position:0% +here and I have and of course when you + + + align:start position:0% +here and I have and of course when you +deposit the polysilicon it gets + + align:start position:0% +deposit the polysilicon it gets + + + align:start position:0% +deposit the polysilicon it gets +deposited everywhere on the wafer so + + align:start position:0% +deposited everywhere on the wafer so + + + align:start position:0% +deposited everywhere on the wafer so +this cross-hatched region is the poly + + align:start position:0% +this cross-hatched region is the poly + + + align:start position:0% +this cross-hatched region is the poly +that I want to pattern and this is the + + align:start position:0% +that I want to pattern and this is the + + + align:start position:0% +that I want to pattern and this is the +photo resist after it's been developed + + align:start position:0% +photo resist after it's been developed + + + align:start position:0% +photo resist after it's been developed +and patterned okay now step B here I put + + align:start position:0% +and patterned okay now step B here I put + + + align:start position:0% +and patterned okay now step B here I put +it into the etcher and I use the + + align:start position:0% +it into the etcher and I use the + + + align:start position:0% +it into the etcher and I use the +photoresist as a mass to etch the poly + + align:start position:0% +photoresist as a mass to etch the poly + + + align:start position:0% +photoresist as a mass to etch the poly +so this looks good I have very nice + + align:start position:0% +so this looks good I have very nice + + + align:start position:0% +so this looks good I have very nice +sidewalls and I stop on the oxide uh but + + align:start position:0% +sidewalls and I stop on the oxide uh but + + + align:start position:0% +sidewalls and I stop on the oxide uh but +what happens well in this region right + + align:start position:0% +what happens well in this region right + + + align:start position:0% +what happens well in this region right +here right look at the thickness of this + + align:start position:0% +here right look at the thickness of this + + + align:start position:0% +here right look at the thickness of this +gate material where it goes over the + + align:start position:0% +gate material where it goes over the + + + align:start position:0% +gate material where it goes over the +step the PO the thickness from this + + align:start position:0% +step the PO the thickness from this + + + align:start position:0% +step the PO the thickness from this +point of the top to the very bottom is + + align:start position:0% +point of the top to the very bottom is + + + align:start position:0% +point of the top to the very bottom is +almost twice what the thickness is in + + align:start position:0% +almost twice what the thickness is in + + + align:start position:0% +almost twice what the thickness is in +the flat region so as a result once I've + + align:start position:0% +the flat region so as a result once I've + + + align:start position:0% +the flat region so as a result once I've +cleared the flats I still have this + + align:start position:0% +cleared the flats I still have this + + + align:start position:0% +cleared the flats I still have this +little Notch of material that's unetched + + align:start position:0% +little Notch of material that's unetched + + + align:start position:0% +little Notch of material that's unetched +that's sitting there because my etch + + align:start position:0% +that's sitting there because my etch + + + align:start position:0% +that's sitting there because my etch +only etches vertically if the edch had + + align:start position:0% +only etches vertically if the edch had + + + align:start position:0% +only etches vertically if the edch had +itched sideways then you wouldn't + + align:start position:0% +itched sideways then you wouldn't + + + align:start position:0% +itched sideways then you wouldn't +wouldn't have to worry about that Notch + + align:start position:0% +wouldn't have to worry about that Notch + + + align:start position:0% +wouldn't have to worry about that Notch +so an isotropic edch don't doesn't tend + + align:start position:0% +so an isotropic edch don't doesn't tend + + + align:start position:0% +so an isotropic edch don't doesn't tend +to give you stringers or Stringer for + + align:start position:0% +to give you stringers or Stringer for + + + align:start position:0% +to give you stringers or Stringer for +Stringer formation is not such a big + + align:start position:0% +Stringer formation is not such a big + + + align:start position:0% +Stringer formation is not such a big +deal but if it's anisotropic it is so + + align:start position:0% +deal but if it's anisotropic it is so + + + align:start position:0% +deal but if it's anisotropic it is so +what we do is you continue in Step C + + align:start position:0% +what we do is you continue in Step C + + + align:start position:0% +what we do is you continue in Step C +with an overetch you continue to beat + + align:start position:0% +with an overetch you continue to beat + + + align:start position:0% +with an overetch you continue to beat +down on this and you know introduce an + + align:start position:0% +down on this and you know introduce an + + + align:start position:0% +down on this and you know introduce an +extra 50% of an overed to get rid of the + + align:start position:0% +extra 50% of an overed to get rid of the + + + align:start position:0% +extra 50% of an overed to get rid of the +stringers if you leave the stringers in + + align:start position:0% +stringers if you leave the stringers in + + + align:start position:0% +stringers if you leave the stringers in +place you'll have shorts on your devices + + align:start position:0% +place you'll have shorts on your devices + + + align:start position:0% +place you'll have shorts on your devices +because then you have the this poly + + align:start position:0% +because then you have the this poly + + + align:start position:0% +because then you have the this poly +going all the way around the field you + + align:start position:0% +going all the way around the field you + + + align:start position:0% +going all the way around the field you +can short The Source Trin to the gate + + align:start position:0% +can short The Source Trin to the gate + + + align:start position:0% +can short The Source Trin to the gate +and you get all kinds of problems now + + align:start position:0% +and you get all kinds of problems now + + + align:start position:0% +and you get all kinds of problems now +this is drawn by a cartoon or by an + + align:start position:0% +this is drawn by a cartoon or by an + + + align:start position:0% +this is drawn by a cartoon or by an +illustrator so it's very easy it doesn't + + align:start position:0% +illustrator so it's very easy it doesn't + + + align:start position:0% +illustrator so it's very easy it doesn't +show any detrimental effect of the + + align:start position:0% +show any detrimental effect of the + + + align:start position:0% +show any detrimental effect of the +overage in practice overetching to + + align:start position:0% +overage in practice overetching to + + + align:start position:0% +overage in practice overetching to +remove stringers almost always has some + + align:start position:0% +remove stringers almost always has some + + + align:start position:0% +remove stringers almost always has some +a little detrimental effect and so the + + align:start position:0% +a little detrimental effect and so the + + + align:start position:0% +a little detrimental effect and so the +name of the game is trying to control + + align:start position:0% +name of the game is trying to control + + + align:start position:0% +name of the game is trying to control +your topography so you minimize your + + align:start position:0% +your topography so you minimize your + + + align:start position:0% +your topography so you minimize your +overetch so you don't have to um destroy + + align:start position:0% +overetch so you don't have to um destroy + + + align:start position:0% +overetch so you don't have to um destroy +the structure by overetching too + + align:start position:0% + + + + align:start position:0% + +much so let's look at slide 17 this is + + align:start position:0% +much so let's look at slide 17 this is + + + align:start position:0% +much so let's look at slide 17 this is +an example of uh on that paper that + + align:start position:0% +an example of uh on that paper that + + + align:start position:0% +an example of uh on that paper that +article from IBM on the effects of + + align:start position:0% +article from IBM on the effects of + + + align:start position:0% +article from IBM on the effects of +topography on gate conductor yield with + + align:start position:0% +topography on gate conductor yield with + + + align:start position:0% +topography on gate conductor yield with +respect to shorting as I mentioned if + + align:start position:0% +respect to shorting as I mentioned if + + + align:start position:0% +respect to shorting as I mentioned if +you end up with stringers the gate can + + align:start position:0% +you end up with stringers the gate can + + + align:start position:0% +you end up with stringers the gate can +be shorted to the source and drain so + + align:start position:0% +be shorted to the source and drain so + + + align:start position:0% +be shorted to the source and drain so +here's an example um and they they edged + + align:start position:0% +here's an example um and they they edged + + + align:start position:0% +here's an example um and they they edged +here 21 Wafers or so 20 Wafers and the + + align:start position:0% +here 21 Wafers or so 20 Wafers and the + + + align:start position:0% +here 21 Wafers or so 20 Wafers and the +percent yield so if you have a high + + align:start position:0% +percent yield so if you have a high + + + align:start position:0% +percent yield so if you have a high +yield it means you don't have gate to + + align:start position:0% +yield it means you don't have gate to + + + align:start position:0% +yield it means you don't have gate to +sour strin shorts if you have a low + + align:start position:0% +sour strin shorts if you have a low + + + align:start position:0% +sour strin shorts if you have a low +yield it means you have shorts between + + align:start position:0% +yield it means you have shorts between + + + align:start position:0% +yield it means you have shorts between +the gate and the source drain so this + + align:start position:0% +the gate and the source drain so this + + + align:start position:0% +the gate and the source drain so this +wafer had no topography so they etched + + align:start position:0% +wafer had no topography so they etched + + + align:start position:0% +wafer had no topography so they etched +the gates on perfectly flat Wafers and + + align:start position:0% +the gates on perfectly flat Wafers and + + + align:start position:0% +the gates on perfectly flat Wafers and +the yield was very high it was like 90% + + align:start position:0% +the yield was very high it was like 90% + + + align:start position:0% +the yield was very high it was like 90% +for these five Wafers uh now they + + align:start position:0% +for these five Wafers uh now they + + + align:start position:0% +for these five Wafers uh now they +introduced at the field loide or + + align:start position:0% +introduced at the field loide or + + + align:start position:0% +introduced at the field loide or +somewhere they introduced a 50 nmet step + + align:start position:0% +somewhere they introduced a 50 nmet step + + + align:start position:0% +somewhere they introduced a 50 nmet step +you can see the the yield goes down a + + align:start position:0% +you can see the the yield goes down a + + + align:start position:0% +you can see the the yield goes down a +little bit not too bad though so they + + align:start position:0% +little bit not too bad though so they + + + align:start position:0% +little bit not too bad though so they +have more shorts and here if you + + align:start position:0% +have more shorts and here if you + + + align:start position:0% +have more shorts and here if you +introduce 100 nanometer step on this + + align:start position:0% +introduce 100 nanometer step on this + + + align:start position:0% +introduce 100 nanometer step on this +particular gate Edge you get a yield of + + align:start position:0% +particular gate Edge you get a yield of + + + align:start position:0% +particular gate Edge you get a yield of +only 30% so 70% of devices are shorted + + align:start position:0% +only 30% so 70% of devices are shorted + + + align:start position:0% +only 30% so 70% of devices are shorted +so this means you're getting a lot of + + align:start position:0% +so this means you're getting a lot of + + + align:start position:0% +so this means you're getting a lot of +stringers forming so you can look + + align:start position:0% +stringers forming so you can look + + + align:start position:0% +stringers forming so you can look +stringers you know visually in the + + align:start position:0% +stringers you know visually in the + + + align:start position:0% +stringers you know visually in the +microscope with a temm or an sem or you + + align:start position:0% +microscope with a temm or an sem or you + + + align:start position:0% +microscope with a temm or an sem or you +can look at them with special test + + align:start position:0% +can look at them with special test + + + align:start position:0% +can look at them with special test +structures where you look at your your + + align:start position:0% +structures where you look at your your + + + align:start position:0% +structures where you look at your your +shorting and your yield so this is an + + align:start position:0% +shorting and your yield so this is an + + + align:start position:0% +shorting and your yield so this is an +example where you would say for this + + align:start position:0% +example where you would say for this + + + align:start position:0% +example where you would say for this +particular gate Edge process that the um + + align:start position:0% +particular gate Edge process that the um + + + align:start position:0% +particular gate Edge process that the um +uh 100 nmet step is too much you need to + + align:start position:0% +uh 100 nmet step is too much you need to + + + align:start position:0% +uh 100 nmet step is too much you need to +reduce your step height and not produce + + align:start position:0% +reduce your step height and not produce + + + align:start position:0% +reduce your step height and not produce +such an Abrupt step uh otherwise you + + align:start position:0% +such an Abrupt step uh otherwise you + + + align:start position:0% +such an Abrupt step uh otherwise you +need to increase your OverWatch time or + + align:start position:0% +need to increase your OverWatch time or + + + align:start position:0% +need to increase your OverWatch time or +do something uh but the yield so + + align:start position:0% +do something uh but the yield so + + + align:start position:0% +do something uh but the yield so +stringers are really a big issue and + + align:start position:0% +stringers are really a big issue and + + + align:start position:0% +stringers are really a big issue and +it's it's a always a trade-off between + + align:start position:0% +it's it's a always a trade-off between + + + align:start position:0% +it's it's a always a trade-off between +their remov removal and uh sort of you + + align:start position:0% +their remov removal and uh sort of you + + + align:start position:0% +their remov removal and uh sort of you +know messing up the + + align:start position:0% + + + + align:start position:0% + +structure here on slide uh 18 I just + + align:start position:0% +structure here on slide uh 18 I just + + + align:start position:0% +structure here on slide uh 18 I just +showed you some I've shown some ways + + align:start position:0% +showed you some I've shown some ways + + + align:start position:0% +showed you some I've shown some ways +where where we can calculate uh overg + + align:start position:0% +where where we can calculate uh overg + + + align:start position:0% +where where we can calculate uh overg +requirements based on the topography one + + align:start position:0% +requirements based on the topography one + + + align:start position:0% +requirements based on the topography one +might have uh during gate etching so + + align:start position:0% +might have uh during gate etching so + + + align:start position:0% +might have uh during gate etching so +here's an example uh on this particular + + align:start position:0% +here's an example uh on this particular + + + align:start position:0% +here's an example uh on this particular +figure where I'm showing you a field + + align:start position:0% +figure where I'm showing you a field + + + align:start position:0% +figure where I'm showing you a field +oxide uh remember we said the field + + align:start position:0% +oxide uh remember we said the field + + + align:start position:0% +oxide uh remember we said the field +oxide might have a certain height which + + align:start position:0% +oxide might have a certain height which + + + align:start position:0% +oxide might have a certain height which +we're calling t subf o x the thickness + + align:start position:0% +we're calling t subf o x the thickness + + + align:start position:0% +we're calling t subf o x the thickness +of the field + + align:start position:0% +of the field + + + align:start position:0% +of the field +oxide um and it has a certain angle that + + align:start position:0% +oxide um and it has a certain angle that + + + align:start position:0% +oxide um and it has a certain angle that +it's made it's been etched so it's not + + align:start position:0% +it's made it's been etched so it's not + + + align:start position:0% +it's made it's been etched so it's not +perfectly straight up and down it has a + + align:start position:0% +perfectly straight up and down it has a + + + align:start position:0% +perfectly straight up and down it has a +certain angle Theta that it makes with + + align:start position:0% +certain angle Theta that it makes with + + + align:start position:0% +certain angle Theta that it makes with +respect to the substrate so that's your + + align:start position:0% +respect to the substrate so that's your + + + align:start position:0% +respect to the substrate so that's your +field oxide and this black region on top + + align:start position:0% +field oxide and this black region on top + + + align:start position:0% +field oxide and this black region on top +is meant to represent the polysilicon so + + align:start position:0% +is meant to represent the polysilicon so + + + align:start position:0% +is meant to represent the polysilicon so +remember polysilicon is always deposited + + align:start position:0% +remember polysilicon is always deposited + + + align:start position:0% +remember polysilicon is always deposited +everywhere across the + + align:start position:0% +everywhere across the + + + align:start position:0% +everywhere across the +chip um so the black region is the + + align:start position:0% +chip um so the black region is the + + + align:start position:0% +chip um so the black region is the +thickness of the poly now you notice + + align:start position:0% +thickness of the poly now you notice + + + align:start position:0% +thickness of the poly now you notice +that on the sloped portion the thickness + + align:start position:0% +that on the sloped portion the thickness + + + align:start position:0% +that on the sloped portion the thickness +of the poly from here to here is given + + align:start position:0% +of the poly from here to here is given + + + align:start position:0% +of the poly from here to here is given +by T poly times the cosine Theta uh + + align:start position:0% +by T poly times the cosine Theta uh + + + align:start position:0% +by T poly times the cosine Theta uh +right so that it's it's thicker here um + + align:start position:0% +right so that it's it's thicker here um + + + align:start position:0% +right so that it's it's thicker here um +than it is than it is here it's just + + align:start position:0% +than it is than it is here it's just + + + align:start position:0% +than it is than it is here it's just +just by + + align:start position:0% +just by + + + align:start position:0% +just by +geometry so the thicker portion of the + + align:start position:0% +geometry so the thicker portion of the + + + align:start position:0% +geometry so the thicker portion of the +poly here means that you need to + + align:start position:0% +poly here means that you need to + + + align:start position:0% +poly here means that you need to +increase in order to get clear all the + + align:start position:0% +increase in order to get clear all the + + + align:start position:0% +increase in order to get clear all the +poly and to avoid forming a Stringer + + align:start position:0% +poly and to avoid forming a Stringer + + + align:start position:0% +poly and to avoid forming a Stringer +down here you need to increase the EDG + + align:start position:0% +down here you need to increase the EDG + + + align:start position:0% +down here you need to increase the EDG +taon and in fact this this formula gives + + align:start position:0% +taon and in fact this this formula gives + + + align:start position:0% +taon and in fact this this formula gives +you here for this particular um + + align:start position:0% +you here for this particular um + + + align:start position:0% +you here for this particular um +topography gives you an example a + + align:start position:0% +topography gives you an example a + + + align:start position:0% +topography gives you an example a +calculation of the over uh here in in + + align:start position:0% +calculation of the over uh here in in + + + align:start position:0% +calculation of the over uh here in in +percent uh that you would need uh for + + align:start position:0% +percent uh that you would need uh for + + + align:start position:0% +percent uh that you would need uh for +this topography and it's 1/ cosine Theta + + align:start position:0% +this topography and it's 1/ cosine Theta + + + align:start position:0% +this topography and it's 1/ cosine Theta +that quantity minus 1 * 100% so if you + + align:start position:0% +that quantity minus 1 * 100% so if you + + + align:start position:0% +that quantity minus 1 * 100% so if you +have a sidewall angle of 45 Dees so this + + align:start position:0% +have a sidewall angle of 45 Dees so this + + + align:start position:0% +have a sidewall angle of 45 Dees so this +particular example says 45 degrees just + + align:start position:0% +particular example says 45 degrees just + + + align:start position:0% +particular example says 45 degrees just +because of this um we need about a 40% + + align:start position:0% +because of this um we need about a 40% + + + align:start position:0% +because of this um we need about a 40% +poly overedge time to avoid stringers so + + align:start position:0% +poly overedge time to avoid stringers so + + + align:start position:0% +poly overedge time to avoid stringers so +what do people do well either you have + + align:start position:0% +what do people do well either you have + + + align:start position:0% +what do people do well either you have +no topography you keep it very flat you + + align:start position:0% +no topography you keep it very flat you + + + align:start position:0% +no topography you keep it very flat you +bury your field loide and that's called + + align:start position:0% +bury your field loide and that's called + + + align:start position:0% +bury your field loide and that's called +a shallow trench or if you are going to + + align:start position:0% +a shallow trench or if you are going to + + + align:start position:0% +a shallow trench or if you are going to +have a little bit of topography you make + + align:start position:0% +have a little bit of topography you make + + + align:start position:0% +have a little bit of topography you make +it you kind of ramp the Angles and you + + align:start position:0% +it you kind of ramp the Angles and you + + + align:start position:0% +it you kind of ramp the Angles and you +make very shallow ramps you don't have + + align:start position:0% +make very shallow ramps you don't have + + + align:start position:0% +make very shallow ramps you don't have +anything really abrupt um so that you + + align:start position:0% +anything really abrupt um so that you + + + align:start position:0% +anything really abrupt um so that you +know depending on this angle you have to + + align:start position:0% +know depending on this angle you have to + + + align:start position:0% +know depending on this angle you have to +adjust your overed time otherwise you'll + + align:start position:0% +adjust your overed time otherwise you'll + + + align:start position:0% +adjust your overed time otherwise you'll +end up with + + align:start position:0% + + + + align:start position:0% + +stringers um sometimes by the way here + + align:start position:0% +stringers um sometimes by the way here + + + align:start position:0% +stringers um sometimes by the way here +on slide 19 sometimes I've been calling + + align:start position:0% +on slide 19 sometimes I've been calling + + + align:start position:0% +on slide 19 sometimes I've been calling +these things stringers stringers is the + + align:start position:0% +these things stringers stringers is the + + + align:start position:0% +these things stringers stringers is the +derogatory term Stringer usually means + + align:start position:0% +derogatory term Stringer usually means + + + align:start position:0% +derogatory term Stringer usually means +something that was left behind that you + + align:start position:0% +something that was left behind that you + + + align:start position:0% +something that was left behind that you +didn't want there um Sometimes some a + + align:start position:0% +didn't want there um Sometimes some a + + + align:start position:0% +didn't want there um Sometimes some a +Stringer is something we want in fact + + align:start position:0% +Stringer is something we want in fact + + + align:start position:0% +Stringer is something we want in fact +it's called when we want it we we give + + align:start position:0% +it's called when we want it we we give + + + align:start position:0% +it's called when we want it we we give +it a a positive name we call it a + + align:start position:0% +it a a positive name we call it a + + + align:start position:0% +it a a positive name we call it a +sidewall spacer so we often use + + align:start position:0% +sidewall spacer so we often use + + + align:start position:0% +sidewall spacer so we often use +anisotropic etches uh without an + + align:start position:0% +anisotropic etches uh without an + + + align:start position:0% +anisotropic etches uh without an +overetch to get a sidewall spacer + + align:start position:0% +overetch to get a sidewall spacer + + + align:start position:0% +overetch to get a sidewall spacer +intentionally here's an example of an + + align:start position:0% +intentionally here's an example of an + + + align:start position:0% +intentionally here's an example of an +intentional production of a Stringer uh + + align:start position:0% +intentional production of a Stringer uh + + + align:start position:0% +intentional production of a Stringer uh +we have a substrate we put one film on + + align:start position:0% +we have a substrate we put one film on + + + align:start position:0% +we have a substrate we put one film on +it could be polysilicon that we have now + + align:start position:0% +it could be polysilicon that we have now + + + align:start position:0% +it could be polysilicon that we have now +patterned with a very sharp step we put + + align:start position:0% +patterned with a very sharp step we put + + + align:start position:0% +patterned with a very sharp step we put +a second film on where we adjust the + + align:start position:0% +a second film on where we adjust the + + + align:start position:0% +a second film on where we adjust the +height or the thickness I should say of + + align:start position:0% +height or the thickness I should say of + + + align:start position:0% +height or the thickness I should say of +the second film to be about oh just the + + align:start position:0% +the second film to be about oh just the + + + align:start position:0% +the second film to be about oh just the +right thickness so that um after I've + + align:start position:0% +right thickness so that um after I've + + + align:start position:0% +right thickness so that um after I've +done a purely vertical or purely + + align:start position:0% +done a purely vertical or purely + + + align:start position:0% +done a purely vertical or purely +anisotropic etch when I'm done I have a + + align:start position:0% +anisotropic etch when I'm done I have a + + + align:start position:0% +anisotropic etch when I'm done I have a +sidewall spacer forming so this material + + align:start position:0% +sidewall spacer forming so this material + + + align:start position:0% +sidewall spacer forming so this material +is Left Behind the nice thing about it + + align:start position:0% +is Left Behind the nice thing about it + + + align:start position:0% +is Left Behind the nice thing about it +is it is self-aligned so I didn't have + + align:start position:0% +is it is self-aligned so I didn't have + + + align:start position:0% +is it is self-aligned so I didn't have +to put another mask down in order to p + + align:start position:0% +to put another mask down in order to p + + + align:start position:0% +to put another mask down in order to p +and do photo lithography to pattern this + + align:start position:0% +and do photo lithography to pattern this + + + align:start position:0% +and do photo lithography to pattern this +all you have to do is have a step in + + align:start position:0% +all you have to do is have a step in + + + align:start position:0% +all you have to do is have a step in +your film number one you put another + + align:start position:0% +your film number one you put another + + + align:start position:0% +your film number one you put another +film down you clear the whole thing with + + align:start position:0% +film down you clear the whole thing with + + + align:start position:0% +film down you clear the whole thing with +a vertical etch and bingo right on the + + align:start position:0% +a vertical etch and bingo right on the + + + align:start position:0% +a vertical etch and bingo right on the +sidewall self-aligned to it is uh a + + align:start position:0% +sidewall self-aligned to it is uh a + + + align:start position:0% +sidewall self-aligned to it is uh a +spacer layer in facts that's exactly how + + align:start position:0% +spacer layer in facts that's exactly how + + + align:start position:0% +spacer layer in facts that's exactly how +spacer layers are formed in modern + + align:start position:0% +spacer layers are formed in modern + + + align:start position:0% +spacer layers are formed in modern +mosfets the polyg gate is etched + + align:start position:0% +mosfets the polyg gate is etched + + + align:start position:0% +mosfets the polyg gate is etched +vertically a certain thickness of + + align:start position:0% +vertically a certain thickness of + + + align:start position:0% +vertically a certain thickness of +nitride or oxide is put down it's etched + + align:start position:0% +nitride or oxide is put down it's etched + + + align:start position:0% +nitride or oxide is put down it's etched +anisotropically and you end up with a + + align:start position:0% +anisotropically and you end up with a + + + align:start position:0% +anisotropically and you end up with a +sidewall spacer so stringers so to speak + + align:start position:0% +sidewall spacer so stringers so to speak + + + align:start position:0% +sidewall spacer so stringers so to speak +are not necessarily bad um usually the + + align:start position:0% +are not necessarily bad um usually the + + + align:start position:0% +are not necessarily bad um usually the +word Stringer means something left + + align:start position:0% +word Stringer means something left + + + align:start position:0% +word Stringer means something left +behind that you don't want but if you do + + align:start position:0% +behind that you don't want but if you do + + + align:start position:0% +behind that you don't want but if you do +want it you call it a sidewall spacer + + align:start position:0% +want it you call it a sidewall spacer + + + align:start position:0% +want it you call it a sidewall spacer +and the width of the spacer which is + + align:start position:0% +and the width of the spacer which is + + + align:start position:0% +and the width of the spacer which is +from this point here to that point there + + align:start position:0% +from this point here to that point there + + + align:start position:0% +from this point here to that point there +that sort of the lateral Dimension is a + + align:start position:0% +that sort of the lateral Dimension is a + + + align:start position:0% +that sort of the lateral Dimension is a +function of how long you did etch and + + align:start position:0% +function of how long you did etch and + + + align:start position:0% +function of how long you did etch and +how over how much overetch you did as + + align:start position:0% +how over how much overetch you did as + + + align:start position:0% +how over how much overetch you did as +well as um the thickness of film two + + align:start position:0% +well as um the thickness of film two + + + align:start position:0% +well as um the thickness of film two +relative to the thickness of film one in + + align:start position:0% +relative to the thickness of film one in + + + align:start position:0% +relative to the thickness of film one in +this example so you can adjust all of + + align:start position:0% +this example so you can adjust all of + + + align:start position:0% +this example so you can adjust all of +those to uh create different width + + align:start position:0% +those to uh create different width + + + align:start position:0% +those to uh create different width +spacers that's a very critical process + + align:start position:0% +spacers that's a very critical process + + + align:start position:0% +spacers that's a very critical process +uh in modern tech + + align:start position:0% +uh in modern tech + + + align:start position:0% +uh in modern tech +technology now this slide actually I + + align:start position:0% +technology now this slide actually I + + + align:start position:0% +technology now this slide actually I +apologize is not in your handouts this + + align:start position:0% +apologize is not in your handouts this + + + align:start position:0% +apologize is not in your handouts this +on page 20 there's two slides here that + + align:start position:0% +on page 20 there's two slides here that + + + align:start position:0% +on page 20 there's two slides here that +that the next couple of three slides are + + align:start position:0% +that the next couple of three slides are + + + align:start position:0% +that the next couple of three slides are +not on your handout uh I don't well no + + align:start position:0% +not on your handout uh I don't well no + + + align:start position:0% +not on your handout uh I don't well no +this one is it's the next two after that + + align:start position:0% +this one is it's the next two after that + + + align:start position:0% +this one is it's the next two after that +that are not uh and if you need the + + align:start position:0% +that are not uh and if you need the + + + align:start position:0% +that are not uh and if you need the +up-to-date handout that they're all + + align:start position:0% +up-to-date handout that they're all + + + align:start position:0% +up-to-date handout that they're all +posted on the web so you can get the + + align:start position:0% +posted on the web so you can get the + + + align:start position:0% +posted on the web so you can get the +PDFs yourself I wanted to is list here + + align:start position:0% +PDFs yourself I wanted to is list here + + + align:start position:0% +PDFs yourself I wanted to is list here +on slide 20 a couple of new issues for + + align:start position:0% +on slide 20 a couple of new issues for + + + align:start position:0% +on slide 20 a couple of new issues for +gate etching and pattering that have + + align:start position:0% +gate etching and pattering that have + + + align:start position:0% +gate etching and pattering that have +come up in the last say three to five + + align:start position:0% +come up in the last say three to five + + + align:start position:0% +come up in the last say three to five +years that you're going to hear more and + + align:start position:0% +years that you're going to hear more and + + + align:start position:0% +years that you're going to hear more and +more about + + align:start position:0% +more about + + + align:start position:0% +more about +uh in the year 2000 this is what people + + align:start position:0% +uh in the year 2000 this is what people + + + align:start position:0% +uh in the year 2000 this is what people +were concerned about they were concerned + + align:start position:0% +were concerned about they were concerned + + + align:start position:0% +were concerned about they were concerned +about etching poly making it vertical + + align:start position:0% +about etching poly making it vertical + + + align:start position:0% +about etching poly making it vertical +maintaining a critical dimension of say + + align:start position:0% +maintaining a critical dimension of say + + + align:start position:0% +maintaining a critical dimension of say +0.18 nanometers .18 microns rather and + + align:start position:0% +0.18 nanometers .18 microns rather and + + + align:start position:0% +0.18 nanometers .18 microns rather and +they were etching through only + + align:start position:0% +they were etching through only + + + align:start position:0% +they were etching through only +polysilicon and putting a putting a + + align:start position:0% +polysilicon and putting a putting a + + + align:start position:0% +polysilicon and putting a putting a +silicide strap on top after after the + + align:start position:0% +silicide strap on top after after the + + + align:start position:0% +silicide strap on top after after the +gate Edge had been completed so that was + + align:start position:0% +gate Edge had been completed so that was + + + align:start position:0% +gate Edge had been completed so that was +the what I should s call the more + + align:start position:0% +the what I should s call the more + + + align:start position:0% +the what I should s call the more +traditional or conventional + + align:start position:0% +traditional or conventional + + + align:start position:0% +traditional or conventional +technology uh what are people doing + + align:start position:0% +technology uh what are people doing + + + align:start position:0% +technology uh what are people doing +these days well people these days are + + align:start position:0% +these days well people these days are + + + align:start position:0% +these days well people these days are +not just doing this for one thing the + + align:start position:0% +not just doing this for one thing the + + + align:start position:0% +not just doing this for one thing the +gates are a lot narrower look at uh + + align:start position:0% +gates are a lot narrower look at uh + + + align:start position:0% +gates are a lot narrower look at uh +today's Gates people are instead of uh + + align:start position:0% +today's Gates people are instead of uh + + + align:start position:0% +today's Gates people are instead of uh +um doing something like um uh 200 + + align:start position:0% +um doing something like um uh 200 + + + align:start position:0% +um doing something like um uh 200 +nanometers we're down to 70 or 80 + + align:start position:0% +nanometers we're down to 70 or 80 + + + align:start position:0% +nanometers we're down to 70 or 80 +nanometers so the dimensions have shrunk + + align:start position:0% +nanometers so the dimensions have shrunk + + + align:start position:0% +nanometers so the dimensions have shrunk +quite a bit and people are doing what + + align:start position:0% +quite a bit and people are doing what + + + align:start position:0% +quite a bit and people are doing what +they call fully silicided Gates so + + align:start position:0% +they call fully silicided Gates so + + + align:start position:0% +they call fully silicided Gates so +instead of just reacting the polysilicon + + align:start position:0% +instead of just reacting the polysilicon + + + align:start position:0% +instead of just reacting the polysilicon +just at the very top of the gate people + + align:start position:0% +just at the very top of the gate people + + + align:start position:0% +just at the very top of the gate people +are actually putting down enough metal + + align:start position:0% +are actually putting down enough metal + + + align:start position:0% +are actually putting down enough metal +and reacting it at the right temperature + + align:start position:0% +and reacting it at the right temperature + + + align:start position:0% +and reacting it at the right temperature +that the metal reacts all the way to the + + align:start position:0% +that the metal reacts all the way to the + + + align:start position:0% +that the metal reacts all the way to the +very bottom in this case on the bottom + + align:start position:0% +very bottom in this case on the bottom + + + align:start position:0% +very bottom in this case on the bottom +would be nickel + + align:start position:0% +would be nickel + + + align:start position:0% +would be nickel +pilicide uh this was formed by + + align:start position:0% +pilicide uh this was formed by + + + align:start position:0% +pilicide uh this was formed by +depositing nickel and reacting it at 450 + + align:start position:0% +depositing nickel and reacting it at 450 + + + align:start position:0% +depositing nickel and reacting it at 450 +all the way to the bottom so there's no + + align:start position:0% +all the way to the bottom so there's no + + + align:start position:0% +all the way to the bottom so there's no +polysilicon left because these days + + align:start position:0% +polysilicon left because these days + + + align:start position:0% +polysilicon left because these days +people don't want polysilicon Gates + + align:start position:0% +people don't want polysilicon Gates + + + align:start position:0% +people don't want polysilicon Gates +polysilicon is a great material to etch + + align:start position:0% +polysilicon is a great material to etch + + + align:start position:0% +polysilicon is a great material to etch +it's highly compatible chemically with + + align:start position:0% +it's highly compatible chemically with + + + align:start position:0% +it's highly compatible chemically with +oxide um but it it has um gate depletion + + align:start position:0% +oxide um but it it has um gate depletion + + + align:start position:0% +oxide um but it it has um gate depletion +problems it doesn't have enough carriers + + align:start position:0% +problems it doesn't have enough carriers + + + align:start position:0% +problems it doesn't have enough carriers +in it polysilicon what's the highest you + + align:start position:0% +in it polysilicon what's the highest you + + + align:start position:0% +in it polysilicon what's the highest you +can dope polysilicon well maybe 1 to 5 * + + align:start position:0% +can dope polysilicon well maybe 1 to 5 * + + + align:start position:0% +can dope polysilicon well maybe 1 to 5 * + + align:start position:0% + + + align:start position:0% +20 so that that that limits your uh + + align:start position:0% +20 so that that that limits your uh + + + align:start position:0% +20 so that that that limits your uh +resistivity and it limits your your gate + + align:start position:0% +resistivity and it limits your your gate + + + align:start position:0% +resistivity and it limits your your gate +depletion people want to use Metals + + align:start position:0% +depletion people want to use Metals + + + align:start position:0% +depletion people want to use Metals +what's the concentration of electrons in + + align:start position:0% +what's the concentration of electrons in + + + align:start position:0% +what's the concentration of electrons in +a metal know 10 22 or 10 23 it's huge + + align:start position:0% +a metal know 10 22 or 10 23 it's huge + + + align:start position:0% +a metal know 10 22 or 10 23 it's huge +it's three or is a magnitude higher so + + align:start position:0% +it's three or is a magnitude higher so + + + align:start position:0% +it's three or is a magnitude higher so +we need more electrons or more holes + + align:start position:0% +we need more electrons or more holes + + + align:start position:0% +we need more electrons or more holes +more carriers in our gates these days + + align:start position:0% +more carriers in our gates these days + + + align:start position:0% +more carriers in our gates these days +the way we do it is we take poly and you + + align:start position:0% +the way we do it is we take poly and you + + + align:start position:0% +the way we do it is we take poly and you +convert it completely to pilicide this + + align:start position:0% +convert it completely to pilicide this + + + align:start position:0% +convert it completely to pilicide this +is called a fully silicided process this + + align:start position:0% +is called a fully silicided process this + + + align:start position:0% +is called a fully silicided process this +is only in research there's a lot of of + + align:start position:0% +is only in research there's a lot of of + + + align:start position:0% +is only in research there's a lot of of +issues with doing this here's an example + + align:start position:0% +issues with doing this here's an example + + + align:start position:0% +issues with doing this here's an example +where they tried to do the suiciding + + align:start position:0% +where they tried to do the suiciding + + + align:start position:0% +where they tried to do the suiciding +with Cobalt in the upper uh micrograph + + align:start position:0% +with Cobalt in the upper uh micrograph + + + align:start position:0% +with Cobalt in the upper uh micrograph +upper SCM micrograph here it didn't work + + align:start position:0% +upper SCM micrograph here it didn't work + + + align:start position:0% +upper SCM micrograph here it didn't work +too well as you can see the Cobalt went + + align:start position:0% +too well as you can see the Cobalt went + + + align:start position:0% +too well as you can see the Cobalt went +down in it didn't make it to the bottom + + align:start position:0% +down in it didn't make it to the bottom + + + align:start position:0% +down in it didn't make it to the bottom +in fact what happens the the Silicon got + + align:start position:0% +in fact what happens the the Silicon got + + + align:start position:0% +in fact what happens the the Silicon got +sucked up in the and next time we'll + + align:start position:0% +sucked up in the and next time we'll + + + align:start position:0% +sucked up in the and next time we'll +talk about pilicide reactions the + + align:start position:0% +talk about pilicide reactions the + + + align:start position:0% +talk about pilicide reactions the +Silicon was actually moving and you + + align:start position:0% +Silicon was actually moving and you + + + align:start position:0% +Silicon was actually moving and you +ended up with a big void so you had no + + align:start position:0% +ended up with a big void so you had no + + + align:start position:0% +ended up with a big void so you had no +gate in this example so this particular + + align:start position:0% +gate in this example so this particular + + + align:start position:0% +gate in this example so this particular +paper was just showing uh I took from uh + + align:start position:0% +paper was just showing uh I took from uh + + + align:start position:0% +paper was just showing uh I took from uh +a few months ago at the vsi conference + + align:start position:0% +a few months ago at the vsi conference + + + align:start position:0% +a few months ago at the vsi conference +in why nickel pilicide works much better + + align:start position:0% +in why nickel pilicide works much better + + + align:start position:0% +in why nickel pilicide works much better +for fully suiciding than does Cobalt + + align:start position:0% +for fully suiciding than does Cobalt + + + align:start position:0% +for fully suiciding than does Cobalt +pilicide which leaves behind uh vo so + + align:start position:0% +pilicide which leaves behind uh vo so + + + align:start position:0% +pilicide which leaves behind uh vo so +there's an example not only are we + + align:start position:0% +there's an example not only are we + + + align:start position:0% +there's an example not only are we +etching poly silan Gates these days we + + align:start position:0% +etching poly silan Gates these days we + + + align:start position:0% +etching poly silan Gates these days we +may end up piling them completely um + + align:start position:0% +may end up piling them completely um + + + align:start position:0% +may end up piling them completely um +that's people are considering there's + + align:start position:0% +that's people are considering there's + + + align:start position:0% +that's people are considering there's +another type of process called which I'm + + align:start position:0% +another type of process called which I'm + + + align:start position:0% +another type of process called which I'm +picturing here on the lower left called + + align:start position:0% +picturing here on the lower left called + + + align:start position:0% +picturing here on the lower left called +a damine replacement gate process and + + align:start position:0% +a damine replacement gate process and + + + align:start position:0% +a damine replacement gate process and +here's an example of a gate where um I + + align:start position:0% +here's an example of a gate where um I + + + align:start position:0% +here's an example of a gate where um I +have Ty nitride so this material uh well + + align:start position:0% +have Ty nitride so this material uh well + + + align:start position:0% +have Ty nitride so this material uh well +it's got tungsten on the top that's the + + align:start position:0% +it's got tungsten on the top that's the + + + align:start position:0% +it's got tungsten on the top that's the +bright material and this sort of gray + + align:start position:0% +bright material and this sort of gray + + + align:start position:0% +bright material and this sort of gray +material is a thin layer of Ty + + align:start position:0% +material is a thin layer of Ty + + + align:start position:0% +material is a thin layer of Ty +nitride and the gate dialectric is half + + align:start position:0% +nitride and the gate dialectric is half + + + align:start position:0% +nitride and the gate dialectric is half +mum dioxide which is down here this is + + align:start position:0% +mum dioxide which is down here this is + + + align:start position:0% +mum dioxide which is down here this is +on a silicon germanium uh type of high + + align:start position:0% +on a silicon germanium uh type of high + + + align:start position:0% +on a silicon germanium uh type of high +Mobility transistor that was also + + align:start position:0% +Mobility transistor that was also + + + align:start position:0% +Mobility transistor that was also +published about six months ago doesn't + + align:start position:0% +published about six months ago doesn't + + + align:start position:0% +published about six months ago doesn't +look anything like a polysilicon gate so + + align:start position:0% +look anything like a polysilicon gate so + + + align:start position:0% +look anything like a polysilicon gate so +not only um are we fully suiciding the + + align:start position:0% +not only um are we fully suiciding the + + + align:start position:0% +not only um are we fully suiciding the +gates but sometimes we're actually + + align:start position:0% +gates but sometimes we're actually + + + align:start position:0% +gates but sometimes we're actually +replacing the polysilicon with another + + align:start position:0% +replacing the polysilicon with another + + + align:start position:0% +replacing the polysilicon with another +material with a gate uh a metal material + + align:start position:0% +material with a gate uh a metal material + + + align:start position:0% +material with a gate uh a metal material +and Ty nitrite is a very popular one so + + align:start position:0% +and Ty nitrite is a very popular one so + + + align:start position:0% +and Ty nitrite is a very popular one so +gate itching is evolving from not only + + align:start position:0% +gate itching is evolving from not only + + + align:start position:0% +gate itching is evolving from not only +having to etge poly and stop on + + align:start position:0% +having to etge poly and stop on + + + align:start position:0% +having to etge poly and stop on +dialectric but now we may have to etge + + align:start position:0% +dialectric but now we may have to etge + + + align:start position:0% +dialectric but now we may have to etge +Metals so lots of new technologies are + + align:start position:0% +Metals so lots of new technologies are + + + align:start position:0% +Metals so lots of new technologies are +being developed uh over the last two or + + align:start position:0% +being developed uh over the last two or + + + align:start position:0% +being developed uh over the last two or +three years and will continue to be + + align:start position:0% +three years and will continue to be + + + align:start position:0% +three years and will continue to be +developed to uh to push the technology + + align:start position:0% +developed to uh to push the technology + + + align:start position:0% +developed to uh to push the technology +forward so it's these next two slides I + + align:start position:0% +forward so it's these next two slides I + + + align:start position:0% +forward so it's these next two slides I +apologize are not in your handouts 21 + + align:start position:0% +apologize are not in your handouts 21 + + + align:start position:0% +apologize are not in your handouts 21 +and 22 but they are on the website so + + align:start position:0% +and 22 but they are on the website so + + + align:start position:0% +and 22 but they are on the website so +you can download the PDF file um how did + + align:start position:0% +you can download the PDF file um how did + + + align:start position:0% +you can download the PDF file um how did +they make I just wanted to show you this + + align:start position:0% +they make I just wanted to show you this + + + align:start position:0% +they make I just wanted to show you this +lower left how does one make a gate that + + align:start position:0% +lower left how does one make a gate that + + + align:start position:0% +lower left how does one make a gate that +looks anything like this just to give + + align:start position:0% +looks anything like this just to give + + + align:start position:0% +looks anything like this just to give +you an + + align:start position:0% +you an + + + align:start position:0% +you an +idea well this is the way you do it um + + align:start position:0% +idea well this is the way you do it um + + + align:start position:0% +idea well this is the way you do it um +uh again this was of this particular uh + + align:start position:0% +uh again this was of this particular uh + + + align:start position:0% +uh again this was of this particular uh +example I took from iedm of 2002 people + + align:start position:0% +example I took from iedm of 2002 people + + + align:start position:0% +example I took from iedm of 2002 people +um make uh use the ordinary process to + + align:start position:0% +um make uh use the ordinary process to + + + align:start position:0% +um make uh use the ordinary process to +make a polysilicon gate so you put down + + align:start position:0% +make a polysilicon gate so you put down + + + align:start position:0% +make a polysilicon gate so you put down +poly you etch it you make your sidewall + + align:start position:0% +poly you etch it you make your sidewall + + + align:start position:0% +poly you etch it you make your sidewall +spacers so that's just like what we've + + align:start position:0% +spacers so that's just like what we've + + + align:start position:0% +spacers so that's just like what we've +learned about in this course and here is + + align:start position:0% +learned about in this course and here is + + + align:start position:0% +learned about in this course and here is +a a very short Channel mosfet here's a + + align:start position:0% +a a very short Channel mosfet here's a + + + align:start position:0% +a a very short Channel mosfet here's a +very long Channel mosfet now at the end + + align:start position:0% +very long Channel mosfet now at the end + + + align:start position:0% +very long Channel mosfet now at the end +of defining your mosfets you put down + + align:start position:0% +of defining your mosfets you put down + + + align:start position:0% +of defining your mosfets you put down +this gray material and you put it + + align:start position:0% +this gray material and you put it + + + align:start position:0% +this gray material and you put it +everywhere very thick so you put down a + + align:start position:0% +everywhere very thick so you put down a + + + align:start position:0% +everywhere very thick so you put down a +dialectric and then you CMP it down so + + align:start position:0% +dialectric and then you CMP it down so + + + align:start position:0% +dialectric and then you CMP it down so +you have dialectric that's been cmpd and + + align:start position:0% +you have dialectric that's been cmpd and + + + align:start position:0% +you have dialectric that's been cmpd and +flattened it's been flattened down just + + align:start position:0% +flattened it's been flattened down just + + + align:start position:0% +flattened it's been flattened down just +so it stops the the uh polishing stops + + align:start position:0% +so it stops the the uh polishing stops + + + align:start position:0% +so it stops the the uh polishing stops +just around this height okay now what + + align:start position:0% +just around this height okay now what + + + align:start position:0% +just around this height okay now what +you do is you the polysilicon is then + + align:start position:0% +you do is you the polysilicon is then + + + align:start position:0% +you do is you the polysilicon is then +wet chemically etched and removed so you + + align:start position:0% +wet chemically etched and removed so you + + + align:start position:0% +wet chemically etched and removed so you +etch out with an etchant that that digs + + align:start position:0% +etch out with an etchant that that digs + + + align:start position:0% +etch out with an etchant that that digs +out the poly um and if you want you can + + align:start position:0% +out the poly um and if you want you can + + + align:start position:0% +out the poly um and if you want you can +even dig out the gate oxide replace it + + align:start position:0% +even dig out the gate oxide replace it + + + align:start position:0% +even dig out the gate oxide replace it +with a high K so so this is what's + + align:start position:0% +with a high K so so this is what's + + + align:start position:0% +with a high K so so this is what's +called a replacement gate process so I'm + + align:start position:0% +called a replacement gate process so I'm + + + align:start position:0% +called a replacement gate process so I'm +actually I use poly to ex your poly you + + align:start position:0% +actually I use poly to ex your poly you + + + align:start position:0% +actually I use poly to ex your poly you +put down cwall spacers you go through + + align:start position:0% +put down cwall spacers you go through + + + align:start position:0% +put down cwall spacers you go through +the high temperature anal and why would + + align:start position:0% +the high temperature anal and why would + + + align:start position:0% +the high temperature anal and why would +anyone want to do this you put down poly + + align:start position:0% +anyone want to do this you put down poly + + + align:start position:0% +anyone want to do this you put down poly +you pattern it and then later on you're + + align:start position:0% +you pattern it and then later on you're + + + align:start position:0% +you pattern it and then later on you're +going to remove it sounds kind of crazy + + align:start position:0% +going to remove it sounds kind of crazy + + + align:start position:0% +going to remove it sounds kind of crazy +why didn't you just put the metal down + + align:start position:0% +why didn't you just put the metal down + + + align:start position:0% +why didn't you just put the metal down +to begin with but does anybody have any + + align:start position:0% +to begin with but does anybody have any + + + align:start position:0% +to begin with but does anybody have any +ideas on why you might want to use poly + + align:start position:0% +ideas on why you might want to use poly + + + align:start position:0% +ideas on why you might want to use poly +and then stick the metal in at the very + + align:start position:0% + + + + align:start position:0% + +end well there's a couple reasons one + + align:start position:0% +end well there's a couple reasons one + + + align:start position:0% +end well there's a couple reasons one +reason is p we know how to etch poly + + align:start position:0% +reason is p we know how to etch poly + + + align:start position:0% +reason is p we know how to etch poly +perfectly right we've spent the last 20 + + align:start position:0% +perfectly right we've spent the last 20 + + + align:start position:0% +perfectly right we've spent the last 20 +years getting perfectly vertical + + align:start position:0% +years getting perfectly vertical + + + align:start position:0% +years getting perfectly vertical +sidewalls so people know how to etch it + + align:start position:0% +sidewalls so people know how to etch it + + + align:start position:0% +sidewalls so people know how to etch it +that's one reason the second reason is + + align:start position:0% +that's one reason the second reason is + + + align:start position:0% +that's one reason the second reason is +poly can go up to very high temperatures + + align:start position:0% +poly can go up to very high temperatures + + + align:start position:0% +poly can go up to very high temperatures +what do I have to do in this process + + align:start position:0% +what do I have to do in this process + + + align:start position:0% +what do I have to do in this process +after you put the gate down you have to + + align:start position:0% +after you put the gate down you have to + + + align:start position:0% +after you put the gate down you have to +implant the sore drains and you have to + + align:start position:0% +implant the sore drains and you have to + + + align:start position:0% +implant the sore drains and you have to +anal them typically at a th000 degrees + + align:start position:0% +anal them typically at a th000 degrees + + + align:start position:0% +anal them typically at a th000 degrees +these days for 10 seconds or 1050 there + + align:start position:0% +these days for 10 seconds or 1050 there + + + align:start position:0% +these days for 10 seconds or 1050 there +aren't too many metals you can pop up to + + align:start position:0% +aren't too many metals you can pop up to + + + align:start position:0% +aren't too many metals you can pop up to +1050 and not either melt them most + + align:start position:0% +1050 and not either melt them most + + + align:start position:0% +1050 and not either melt them most +metals will melt or if you don't melt + + align:start position:0% +metals will melt or if you don't melt + + + align:start position:0% +metals will melt or if you don't melt +them they could undergo dramatic uh + + align:start position:0% +them they could undergo dramatic uh + + + align:start position:0% +them they could undergo dramatic uh +phase transformation some of them could + + align:start position:0% +phase transformation some of them could + + + align:start position:0% +phase transformation some of them could +diffuse into the wafer and cause + + align:start position:0% +diffuse into the wafer and cause + + + align:start position:0% +diffuse into the wafer and cause +problems with deep levels so metals are + + align:start position:0% +problems with deep levels so metals are + + + align:start position:0% +problems with deep levels so metals are +not considered very good to have at high + + align:start position:0% +not considered very good to have at high + + + align:start position:0% +not considered very good to have at high +temperatures so this is a way of using + + align:start position:0% +temperatures so this is a way of using + + + align:start position:0% +temperatures so this is a way of using +poly as a dummy we know exactly how to + + align:start position:0% +poly as a dummy we know exactly how to + + + align:start position:0% +poly as a dummy we know exactly how to +pattern it the only problem with it it + + align:start position:0% +pattern it the only problem with it it + + + align:start position:0% +pattern it the only problem with it it +just doesn't have enough carriers well + + align:start position:0% +just doesn't have enough carriers well + + + align:start position:0% +just doesn't have enough carriers well +we'll put it in the process so we won't + + align:start position:0% +we'll put it in the process so we won't + + + align:start position:0% +we'll put it in the process so we won't +change the process till the very end + + align:start position:0% +change the process till the very end + + + align:start position:0% +change the process till the very end +we'll etch it out um I don't know how + + align:start position:0% +we'll etch it out um I don't know how + + + align:start position:0% +we'll etch it out um I don't know how +manufacturable I don't believe anyone is + + align:start position:0% +manufacturable I don't believe anyone is + + + align:start position:0% +manufacturable I don't believe anyone is +manufacturing products this was just + + align:start position:0% +manufacturing products this was just + + + align:start position:0% +manufacturing products this was just +published in research about two years + + align:start position:0% +published in research about two years + + + align:start position:0% +published in research about two years +ago it is a kind of a neat idea so after + + align:start position:0% +ago it is a kind of a neat idea so after + + + align:start position:0% +ago it is a kind of a neat idea so after +after You' removed this and you open + + align:start position:0% +after You' removed this and you open + + + align:start position:0% +after You' removed this and you open +this hole well then you have an open + + align:start position:0% +this hole well then you have an open + + + align:start position:0% +this hole well then you have an open +hole you can put down your high k um you + + align:start position:0% +hole you can put down your high k um you + + + align:start position:0% +hole you can put down your high k um you +know your haum dioxide you can put down + + align:start position:0% +know your haum dioxide you can put down + + + align:start position:0% +know your haum dioxide you can put down +your Ty nitride by sputtering and a + + align:start position:0% +your Ty nitride by sputtering and a + + + align:start position:0% +your Ty nitride by sputtering and a +Tungsten cap and then maybe some capping + + align:start position:0% +Tungsten cap and then maybe some capping + + + align:start position:0% +Tungsten cap and then maybe some capping +layer of dialectric and CMP the whole + + align:start position:0% +layer of dialectric and CMP the whole + + + align:start position:0% +layer of dialectric and CMP the whole +thing + + align:start position:0% +thing + + + align:start position:0% +thing +down so that's how they got in that last + + align:start position:0% +down so that's how they got in that last + + + align:start position:0% +down so that's how they got in that last +picture that's how they got that uh + + align:start position:0% +picture that's how they got that uh + + + align:start position:0% +picture that's how they got that uh +replacement gate uh in fact this slide + + align:start position:0% +replacement gate uh in fact this slide + + + align:start position:0% +replacement gate uh in fact this slide +22 was also not in your handout but this + + align:start position:0% +22 was also not in your handout but this + + + align:start position:0% +22 was also not in your handout but this +is what it looks like on uh in a TM + + align:start position:0% +is what it looks like on uh in a TM + + + align:start position:0% +is what it looks like on uh in a TM +cross-section in a 50 nmet mosset where + + align:start position:0% +cross-section in a 50 nmet mosset where + + + align:start position:0% +cross-section in a 50 nmet mosset where +they removed the poly they dug it out + + align:start position:0% +they removed the poly they dug it out + + + align:start position:0% +they removed the poly they dug it out +they put in this very dark black layer + + align:start position:0% +they put in this very dark black layer + + + align:start position:0% +they put in this very dark black layer +of half dioxide so that is your gate + + align:start position:0% +of half dioxide so that is your gate + + + align:start position:0% +of half dioxide so that is your gate +dialectric um the Ty nitride is next a + + align:start position:0% +dialectric um the Ty nitride is next a + + + align:start position:0% +dialectric um the Ty nitride is next a +very thin layer that is your gate + + align:start position:0% +very thin layer that is your gate + + + align:start position:0% +very thin layer that is your gate +material um they then have tungsten that + + align:start position:0% +material um they then have tungsten that + + + align:start position:0% +material um they then have tungsten that +they fill it up with so they have uh the + + align:start position:0% +they fill it up with so they have uh the + + + align:start position:0% +they fill it up with so they have uh the +tungsten material which is a little bit + + align:start position:0% +tungsten material which is a little bit + + + align:start position:0% +tungsten material which is a little bit +more um uh environmentally friendly or + + align:start position:0% +more um uh environmentally friendly or + + + align:start position:0% +more um uh environmentally friendly or +it's an easier material to work with to + + align:start position:0% +it's an easier material to work with to + + + align:start position:0% +it's an easier material to work with to +fill up the plug so that's an example uh + + align:start position:0% +fill up the plug so that's an example uh + + + align:start position:0% +fill up the plug so that's an example uh +where the poly was completely removed + + align:start position:0% +where the poly was completely removed + + + align:start position:0% +where the poly was completely removed +so new types of things have to be done + + align:start position:0% +so new types of things have to be done + + + align:start position:0% +so new types of things have to be done +uh with uh uh forming uh Gates these + + align:start position:0% +uh with uh uh forming uh Gates these + + + align:start position:0% +uh with uh uh forming uh Gates these +days okay let me move on here uh now on + + align:start position:0% +days okay let me move on here uh now on + + + align:start position:0% +days okay let me move on here uh now on +slide 23 I I'll move away from the gate + + align:start position:0% +slide 23 I I'll move away from the gate + + + align:start position:0% +slide 23 I I'll move away from the gate +etching and talk a little bit I'll spend + + align:start position:0% +etching and talk a little bit I'll spend + + + align:start position:0% +etching and talk a little bit I'll spend +a few minutes about modeling and + + align:start position:0% +a few minutes about modeling and + + + align:start position:0% +a few minutes about modeling and +simulation um there's a lot of + + align:start position:0% +simulation um there's a lot of + + + align:start position:0% +simulation um there's a lot of +similarity between the models that we + + align:start position:0% +similarity between the models that we + + + align:start position:0% +similarity between the models that we +introduced for deposition the last + + align:start position:0% +introduced for deposition the last + + + align:start position:0% +introduced for deposition the last +couple of lectures that were in chapter + + align:start position:0% +couple of lectures that were in chapter + + + align:start position:0% +couple of lectures that were in chapter +nine and the etching + + align:start position:0% +nine and the etching + + + align:start position:0% +nine and the etching +models um and why is that well well both + + align:start position:0% +models um and why is that well well both + + + align:start position:0% +models um and why is that well well both +deposition and etching use incoming + + align:start position:0% +deposition and etching use incoming + + + align:start position:0% +deposition and etching use incoming +chemical or neutral uh species and ion + + align:start position:0% +chemical or neutral uh species and ion + + + align:start position:0% +chemical or neutral uh species and ion +fluxes and they have a lot of very + + align:start position:0% +fluxes and they have a lot of very + + + align:start position:0% +fluxes and they have a lot of very +similar processes the difference is when + + align:start position:0% +similar processes the difference is when + + + align:start position:0% +similar processes the difference is when +you're depositing the species come down + + align:start position:0% +you're depositing the species come down + + + align:start position:0% +you're depositing the species come down +they move around and they stick they + + align:start position:0% +they move around and they stick they + + + align:start position:0% +they move around and they stick they +react in some way the deposit when + + align:start position:0% +react in some way the deposit when + + + align:start position:0% +react in some way the deposit when +you're etching they come down they move + + align:start position:0% +you're etching they come down they move + + + align:start position:0% +you're etching they come down they move +around they have a chemical reaction but + + align:start position:0% +around they have a chemical reaction but + + + align:start position:0% +around they have a chemical reaction but +they actually remove material so one can + + align:start position:0% +they actually remove material so one can + + + align:start position:0% +they actually remove material so one can +be considered mathematically the inverse + + align:start position:0% +be considered mathematically the inverse + + + align:start position:0% +be considered mathematically the inverse +of the other but um because in math you + + align:start position:0% +of the other but um because in math you + + + align:start position:0% +of the other but um because in math you +can just change the sign from positive + + align:start position:0% +can just change the sign from positive + + + align:start position:0% +can just change the sign from positive +to negative in a computer program + + align:start position:0% +to negative in a computer program + + + align:start position:0% +to negative in a computer program +you can use very much uh similar uh + + align:start position:0% +you can use very much uh similar uh + + + align:start position:0% +you can use very much uh similar uh +methodologies to model uh etching so + + align:start position:0% +methodologies to model uh etching so + + + align:start position:0% +methodologies to model uh etching so +here's an an example of of things uh + + align:start position:0% +here's an an example of of things uh + + + align:start position:0% +here's an an example of of things uh +that might take place um during etching + + align:start position:0% +that might take place um during etching + + + align:start position:0% +that might take place um during etching +you have ionic species coming down you + + align:start position:0% +you have ionic species coming down you + + + align:start position:0% +you have ionic species coming down you +have things coming down and being + + align:start position:0% +have things coming down and being + + + align:start position:0% +have things coming down and being +sputtered away and um um you may have + + align:start position:0% +sputtered away and um um you may have + + + align:start position:0% +sputtered away and um um you may have +things coming down and being emitted or + + align:start position:0% +things coming down and being emitted or + + + align:start position:0% +things coming down and being emitted or +desorbed so a lot of these uh fluxes the + + align:start position:0% +desorbed so a lot of these uh fluxes the + + + align:start position:0% +desorbed so a lot of these uh fluxes the +whole flux equation uh is very much + + align:start position:0% +whole flux equation uh is very much + + + align:start position:0% +whole flux equation uh is very much +analogous between uh deposition and + + align:start position:0% + + + + align:start position:0% + +itching here on slide 24 um just like in + + align:start position:0% +itching here on slide 24 um just like in + + + align:start position:0% +itching here on slide 24 um just like in +the case of + + align:start position:0% +the case of + + + align:start position:0% +the case of +deposition um the etch rate is + + align:start position:0% +deposition um the etch rate is + + + align:start position:0% +deposition um the etch rate is +proportional to the net flux arriving at + + align:start position:0% +proportional to the net flux arriving at + + + align:start position:0% +proportional to the net flux arriving at +a point remember we said the deposition + + align:start position:0% +a point remember we said the deposition + + + align:start position:0% +a point remember we said the deposition +was proportional to the net flux the + + align:start position:0% +was proportional to the net flux the + + + align:start position:0% +was proportional to the net flux the +flux in minus the flux out well the etch + + align:start position:0% +flux in minus the flux out well the etch + + + align:start position:0% +flux in minus the flux out well the etch +rate is often proportional to net flux + + align:start position:0% +rate is often proportional to net flux + + + align:start position:0% +rate is often proportional to net flux +so we have the same kind of situation + + align:start position:0% +so we have the same kind of situation + + + align:start position:0% +so we have the same kind of situation +you have a wafer which has a certain + + align:start position:0% +you have a wafer which has a certain + + + align:start position:0% +you have a wafer which has a certain +pattern surface you form a virtual + + align:start position:0% +pattern surface you form a virtual + + + align:start position:0% +pattern surface you form a virtual +dashed uh plane above it with and you + + align:start position:0% +dashed uh plane above it with and you + + + align:start position:0% +dashed uh plane above it with and you +look at the distribution the angular + + align:start position:0% +look at the distribution the angular + + + align:start position:0% +look at the distribution the angular +distribution uh of the species arriving + + align:start position:0% +distribution uh of the species arriving + + + align:start position:0% +distribution uh of the species arriving +just above the surface on that Dash + + align:start position:0% +just above the surface on that Dash + + + align:start position:0% +just above the surface on that Dash +plane uh if you have a chemical etching + + align:start position:0% +plane uh if you have a chemical etching + + + align:start position:0% +plane uh if you have a chemical etching +species that that is something that's + + align:start position:0% +species that that is something that's + + + align:start position:0% +species that that is something that's +neutral that is not ionized uh you + + align:start position:0% +neutral that is not ionized uh you + + + align:start position:0% +neutral that is not ionized uh you +assume you have an isotropic arrival + + align:start position:0% +assume you have an isotropic arrival + + + align:start position:0% +assume you have an isotropic arrival +distribution so you put a cosine Theta + + align:start position:0% +distribution so you put a cosine Theta + + + align:start position:0% +distribution so you put a cosine Theta +to uh to the N where n equals 1 for a + + align:start position:0% +to uh to the N where n equals 1 for a + + + align:start position:0% +to uh to the N where n equals 1 for a +chemical species if you have an ionic + + align:start position:0% +chemical species if you have an ionic + + + align:start position:0% +chemical species if you have an ionic +species it can be accelerated towards + + align:start position:0% +species it can be accelerated towards + + + align:start position:0% +species it can be accelerated towards +the surface it can arrive very uh much + + align:start position:0% +the surface it can arrive very uh much + + + align:start position:0% +the surface it can arrive very uh much +with a vertical orientation and here we + + align:start position:0% +with a vertical orientation and here we + + + align:start position:0% +with a vertical orientation and here we +for etching we put in cosine Theta the N + + align:start position:0% +for etching we put in cosine Theta the N + + + align:start position:0% +for etching we put in cosine Theta the N +where n could vary between 10 and 100 or + + align:start position:0% +where n could vary between 10 and 100 or + + + align:start position:0% +where n could vary between 10 and 100 or +something like that remember the higher + + align:start position:0% +something like that remember the higher + + + align:start position:0% +something like that remember the higher +the value of n much more vertical the + + align:start position:0% +the value of n much more vertical the + + + align:start position:0% +the value of n much more vertical the +distribution um in the deposition case + + align:start position:0% +distribution um in the deposition case + + + align:start position:0% +distribution um in the deposition case +remember we had the concept of a + + align:start position:0% +remember we had the concept of a + + + align:start position:0% +remember we had the concept of a +sticking coefficient uh well we use uh + + align:start position:0% +sticking coefficient uh well we use uh + + + align:start position:0% +sticking coefficient uh well we use uh +very much that same concept um we when + + align:start position:0% +very much that same concept um we when + + + align:start position:0% +very much that same concept um we when +we're etching we say an ionized species + + align:start position:0% +we're etching we say an ionized species + + + align:start position:0% +we're etching we say an ionized species +usually sticks where it's + + align:start position:0% +usually sticks where it's + + + align:start position:0% +usually sticks where it's +lands um and it's going to react and + + align:start position:0% +lands um and it's going to react and + + + align:start position:0% +lands um and it's going to react and +itch while a reactive neutral species + + align:start position:0% +itch while a reactive neutral species + + + align:start position:0% +itch while a reactive neutral species +may have a low SC value it might bounce + + align:start position:0% +may have a low SC value it might bounce + + + align:start position:0% +may have a low SC value it might bounce +around before it finally reacts and + + align:start position:0% +around before it finally reacts and + + + align:start position:0% +around before it finally reacts and +etches off the + + align:start position:0% +etches off the + + + align:start position:0% +etches off the +surface uh as far as the physical + + align:start position:0% +surface uh as far as the physical + + + align:start position:0% +surface uh as far as the physical +component of etching like sputtering the + + align:start position:0% +component of etching like sputtering the + + + align:start position:0% +component of etching like sputtering the +sputtering yield has the same angular + + align:start position:0% +sputtering yield has the same angular + + + align:start position:0% +sputtering yield has the same angular +dependence that we used in the + + align:start position:0% +dependence that we used in the + + + align:start position:0% +dependence that we used in the +deposition case so again very similar uh + + align:start position:0% +deposition case so again very similar uh + + + align:start position:0% +deposition case so again very similar uh +process going on when we include + + align:start position:0% + + + + align:start position:0% + +sputtering so slide 20 um 25 I'm showing + + align:start position:0% +sputtering so slide 20 um 25 I'm showing + + + align:start position:0% +sputtering so slide 20 um 25 I'm showing +What's called the linear etch + + align:start position:0% +What's called the linear etch + + + align:start position:0% +What's called the linear etch +model um there have been some very + + align:start position:0% +model um there have been some very + + + align:start position:0% +model um there have been some very +specific models in developed uh here I + + align:start position:0% +specific models in developed uh here I + + + align:start position:0% +specific models in developed uh here I +just want to give a sort of a general + + align:start position:0% +just want to give a sort of a general + + + align:start position:0% +just want to give a sort of a general +purpose etch models a couple of them + + align:start position:0% +purpose etch models a couple of them + + + align:start position:0% +purpose etch models a couple of them +which can be applied uh + + align:start position:0% +which can be applied uh + + + align:start position:0% +which can be applied uh +broadly the so-called linear model + + align:start position:0% +broadly the so-called linear model + + + align:start position:0% +broadly the so-called linear model +assumes that there are chemical and + + align:start position:0% +assumes that there are chemical and + + + align:start position:0% +assumes that there are chemical and +physical components that act + + align:start position:0% +physical components that act + + + align:start position:0% +physical components that act +independently so they're not + + align:start position:0% +independently so they're not + + + align:start position:0% +independently so they're not +linked um uh they're independent of each + + align:start position:0% +linked um uh they're independent of each + + + align:start position:0% +linked um uh they're independent of each +other and in this case we have um a an + + align:start position:0% +other and in this case we have um a an + + + align:start position:0% +other and in this case we have um a an +etch rate that is given by just a of two + + align:start position:0% +etch rate that is given by just a of two + + + align:start position:0% +etch rate that is given by just a of two +terms uh one term that has to do with a + + align:start position:0% +terms uh one term that has to do with a + + + align:start position:0% +terms uh one term that has to do with a +chemical uh flux F subc what the + + align:start position:0% +chemical uh flux F subc what the + + + align:start position:0% +chemical uh flux F subc what the +chemical flux onto the surface at any + + align:start position:0% +chemical flux onto the surface at any + + + align:start position:0% +chemical flux onto the surface at any +point and another term that is + + align:start position:0% +point and another term that is + + + align:start position:0% +point and another term that is +proportional to fepi the ionic + + align:start position:0% +proportional to fepi the ionic + + + align:start position:0% +proportional to fepi the ionic +flux in front of each one of these + + align:start position:0% +flux in front of each one of these + + + align:start position:0% +flux in front of each one of these +fluxes is a k Factor uh Ki and KF these + + align:start position:0% +fluxes is a k Factor uh Ki and KF these + + + align:start position:0% +fluxes is a k Factor uh Ki and KF these +are relative rate constants for the two + + align:start position:0% +are relative rate constants for the two + + + align:start position:0% +are relative rate constants for the two +components uh usually you use these as + + align:start position:0% +components uh usually you use these as + + + align:start position:0% +components uh usually you use these as +fitting parameters uh if I have a large + + align:start position:0% +fitting parameters uh if I have a large + + + align:start position:0% +fitting parameters uh if I have a large +Ki I have a lot of ionic component um + + align:start position:0% +Ki I have a lot of ionic component um + + + align:start position:0% +Ki I have a lot of ionic component um +whereas if I have a large KF would be + + align:start position:0% +whereas if I have a large KF would be + + + align:start position:0% +whereas if I have a large KF would be +more of a chemical + + align:start position:0% +more of a chemical + + + align:start position:0% +more of a chemical +component um what is that uh the + + align:start position:0% +component um what is that uh the + + + align:start position:0% +component um what is that uh the +physical component can be due to purely + + align:start position:0% +physical component can be due to purely + + + align:start position:0% +physical component can be due to purely +physical sputtering for example like we + + align:start position:0% +physical sputtering for example like we + + + align:start position:0% +physical sputtering for example like we +talked about before or it actually can + + align:start position:0% +talked about before or it actually can + + + align:start position:0% +talked about before or it actually can +be some ion enhanced mechanism uh in the + + align:start position:0% +be some ion enhanced mechanism uh in the + + + align:start position:0% +be some ion enhanced mechanism uh in the +regime where the chemical flux is not + + align:start position:0% +regime where the chemical flux is not + + + align:start position:0% +regime where the chemical flux is not +limiting the ion etching so this is a an + + align:start position:0% +limiting the ion etching so this is a an + + + align:start position:0% +limiting the ion etching so this is a an +a linear etch model with independent + + align:start position:0% +a linear etch model with independent + + + align:start position:0% +a linear etch model with independent +chemical and physical uh + + align:start position:0% + + + + align:start position:0% + +components here's just an example of + + align:start position:0% +components here's just an example of + + + align:start position:0% +components here's just an example of +some simulations remember Speedy I said + + align:start position:0% +some simulations remember Speedy I said + + + align:start position:0% +some simulations remember Speedy I said +was a topography simulator does both + + align:start position:0% +was a topography simulator does both + + + align:start position:0% +was a topography simulator does both +deposition and + + align:start position:0% +deposition and + + + align:start position:0% +deposition and +etching um here on on slide 26 I have + + align:start position:0% +etching um here on on slide 26 I have + + + align:start position:0% +etching um here on on slide 26 I have +some Speedy simulations using the linear + + align:start position:0% +some Speedy simulations using the linear + + + align:start position:0% +some Speedy simulations using the linear +Edge model and uh we have a b and c well + + align:start position:0% +Edge model and uh we have a b and c well + + + align:start position:0% +Edge model and uh we have a b and c well +what we're doing uh each one of these + + align:start position:0% +what we're doing uh each one of these + + + align:start position:0% +what we're doing uh each one of these +Contours again represents the shape of + + align:start position:0% +Contours again represents the shape of + + + align:start position:0% +Contours again represents the shape of +the edge surface at a given time so + + align:start position:0% +the edge surface at a given time so + + + align:start position:0% +the edge surface at a given time so +we're looking at snapshots in time here + + align:start position:0% +we're looking at snapshots in time here + + + align:start position:0% +we're looking at snapshots in time here +I am I have a edge mask it looks like + + align:start position:0% +I am I have a edge mask it looks like + + + align:start position:0% +I am I have a edge mask it looks like +this so this is my masking material on + + align:start position:0% +this so this is my masking material on + + + align:start position:0% +this so this is my masking material on +the surface and I'm etching into the + + align:start position:0% +the surface and I'm etching into the + + + align:start position:0% +the surface and I'm etching into the +Silicon or into the film below + + align:start position:0% +Silicon or into the film below + + + align:start position:0% +Silicon or into the film below +here I have n equals 1 uh and so for my + + align:start position:0% +here I have n equals 1 uh and so for my + + + align:start position:0% +here I have n equals 1 uh and so for my +chemical flux angular distribution so + + align:start position:0% +chemical flux angular distribution so + + + align:start position:0% +chemical flux angular distribution so +it's going to give you a fairly uh + + align:start position:0% +it's going to give you a fairly uh + + + align:start position:0% +it's going to give you a fairly uh +isotropic uh type of uh of etch you see + + align:start position:0% +isotropic uh type of uh of etch you see + + + align:start position:0% +isotropic uh type of uh of etch you see +you're etching laterally this Dimension + + align:start position:0% +you're etching laterally this Dimension + + + align:start position:0% +you're etching laterally this Dimension +just about the same as you etch + + align:start position:0% +just about the same as you etch + + + align:start position:0% +just about the same as you etch +vertically so there's an isotropic type + + align:start position:0% +vertically so there's an isotropic type + + + align:start position:0% +vertically so there's an isotropic type +of edge here's um where you have n + + align:start position:0% +of edge here's um where you have n + + + align:start position:0% +of edge here's um where you have n +equals 80 uh for the ionic uh flux + + align:start position:0% +equals 80 uh for the ionic uh flux + + + align:start position:0% +equals 80 uh for the ionic uh flux +angular distribution and you end up with + + align:start position:0% +angular distribution and you end up with + + + align:start position:0% +angular distribution and you end up with +very vertical etching it's um basically + + align:start position:0% +very vertical etching it's um basically + + + align:start position:0% +very vertical etching it's um basically +everything's coming straight down + + align:start position:0% +everything's coming straight down + + + align:start position:0% +everything's coming straight down +and etching there's not much lateral + + align:start position:0% +and etching there's not much lateral + + + align:start position:0% +and etching there's not much lateral +etching so this is all chemical etching + + align:start position:0% +etching so this is all chemical etching + + + align:start position:0% +etching so this is all chemical etching +the ion flux of zero all physical + + align:start position:0% +the ion flux of zero all physical + + + align:start position:0% +the ion flux of zero all physical +etching in this case and here's a 50/50 + + align:start position:0% +etching in this case and here's a 50/50 + + + align:start position:0% +etching in this case and here's a 50/50 +I have half chemical and um half + + align:start position:0% +I have half chemical and um half + + + align:start position:0% +I have half chemical and um half +physical fluxes of both and you can see + + align:start position:0% +physical fluxes of both and you can see + + + align:start position:0% +physical fluxes of both and you can see +it it etches a little bit laterally and + + align:start position:0% +it it etches a little bit laterally and + + + align:start position:0% +it it etches a little bit laterally and +and a certain amount vertically so you + + align:start position:0% +and a certain amount vertically so you + + + align:start position:0% +and a certain amount vertically so you +can generate a variety of edge profiles + + align:start position:0% +can generate a variety of edge profiles + + + align:start position:0% +can generate a variety of edge profiles +using a relatively simple um model with + + align:start position:0% +using a relatively simple um model with + + + align:start position:0% +using a relatively simple um model with +only uh you know maybe three or four + + align:start position:0% +only uh you know maybe three or four + + + align:start position:0% +only uh you know maybe three or four +parameters uh and then you can fit this + + align:start position:0% +parameters uh and then you can fit this + + + align:start position:0% +parameters uh and then you can fit this +to what you actually see in your uh + + align:start position:0% +to what you actually see in your uh + + + align:start position:0% +to what you actually see in your uh +actual + + align:start position:0% + + + + align:start position:0% + +etches the second type of model which is + + align:start position:0% +etches the second type of model which is + + + align:start position:0% +etches the second type of model which is +quite different that's shown here on + + align:start position:0% +quite different that's shown here on + + + align:start position:0% +quite different that's shown here on +slide 27 is called a saturation uh- + + align:start position:0% +slide 27 is called a saturation uh- + + + align:start position:0% +slide 27 is called a saturation uh- +absorption type of edge model um because + + align:start position:0% +absorption type of edge model um because + + + align:start position:0% +absorption type of edge model um because +the fact very often uh this is used when + + align:start position:0% +the fact very often uh this is used when + + + align:start position:0% +the fact very often uh this is used when +the chemical or the neutral etching and + + align:start position:0% +the chemical or the neutral etching and + + + align:start position:0% +the chemical or the neutral etching and +the ion etching or the physical etch + + align:start position:0% +the ion etching or the physical etch + + + align:start position:0% +the ion etching or the physical etch +components are coupled so when one of + + align:start position:0% +components are coupled so when one of + + + align:start position:0% +components are coupled so when one of +these affects the other when you have a + + align:start position:0% +these affects the other when you have a + + + align:start position:0% +these affects the other when you have a +synergistic effect which know is often + + align:start position:0% +synergistic effect which know is often + + + align:start position:0% +synergistic effect which know is often +the case especially when you have side + + align:start position:0% +the case especially when you have side + + + align:start position:0% +the case especially when you have side +wall inhibitor layers or something um + + align:start position:0% +wall inhibitor layers or something um + + + align:start position:0% +wall inhibitor layers or something um +you need to use this type of model so + + align:start position:0% +you need to use this type of model so + + + align:start position:0% +you need to use this type of model so +here's an example um let's say you need + + align:start position:0% +here's an example um let's say you need + + + align:start position:0% +here's an example um let's say you need +an ion flux to remove an inhibitor layer + + align:start position:0% +an ion flux to remove an inhibitor layer + + + align:start position:0% +an ion flux to remove an inhibitor layer +that is formed by uh chemical etching so + + align:start position:0% +that is formed by uh chemical etching so + + + align:start position:0% +that is formed by uh chemical etching so +instead of a linear model where these + + align:start position:0% +instead of a linear model where these + + + align:start position:0% +instead of a linear model where these +two just added up linearly these add + + align:start position:0% +two just added up linearly these add + + + align:start position:0% +two just added up linearly these add +sort of like uh resistors in parallel so + + align:start position:0% +sort of like uh resistors in parallel so + + + align:start position:0% +sort of like uh resistors in parallel so +to speak or capacitors in series if + + align:start position:0% +to speak or capacitors in series if + + + align:start position:0% +to speak or capacitors in series if +you're electrical engineer The Edge rate + + align:start position:0% +you're electrical engineer The Edge rate + + + align:start position:0% +you're electrical engineer The Edge rate +is just given by the inverse one over + + align:start position:0% +is just given by the inverse one over + + + align:start position:0% +is just given by the inverse one over +the sum of 1 K fi plus 1 SC FC so + + align:start position:0% +the sum of 1 K fi plus 1 SC FC so + + + align:start position:0% +the sum of 1 K fi plus 1 SC FC so +there's a one over a chemical flux and + + align:start position:0% +there's a one over a chemical flux and + + + align:start position:0% +there's a one over a chemical flux and +one over an ionic + + align:start position:0% +one over an ionic + + + align:start position:0% +one over an ionic +flux if you plot this equation what does + + align:start position:0% +flux if you plot this equation what does + + + align:start position:0% +flux if you plot this equation what does +it look like here's here's the overall + + align:start position:0% +it look like here's here's the overall + + + align:start position:0% +it look like here's here's the overall +Ed rate as a function of now I'm + + align:start position:0% +Ed rate as a function of now I'm + + + align:start position:0% +Ed rate as a function of now I'm +plotting as a function of the ion flux + + align:start position:0% +plotting as a function of the ion flux + + + align:start position:0% +plotting as a function of the ion flux +um times K subi so it's a function of + + align:start position:0% +um times K subi so it's a function of + + + align:start position:0% +um times K subi so it's a function of +this quantity so it goes up um and and + + align:start position:0% +this quantity so it goes up um and and + + + align:start position:0% +this quantity so it goes up um and and +in the the parameter here is the + + align:start position:0% +in the the parameter here is the + + + align:start position:0% +in the the parameter here is the +chemical flux SC so if either flux is + + align:start position:0% +chemical flux SC so if either flux is + + + align:start position:0% +chemical flux SC so if either flux is +zero so if SC is zero I get zero H rate + + align:start position:0% +zero so if SC is zero I get zero H rate + + + align:start position:0% +zero so if SC is zero I get zero H rate +regardless of what my ion flux is you + + align:start position:0% +regardless of what my ion flux is you + + + align:start position:0% +regardless of what my ion flux is you +need both chemical and the ionic flux um + + align:start position:0% +need both chemical and the ionic flux um + + + align:start position:0% +need both chemical and the ionic flux um +uh so if either flux is zero the overall + + align:start position:0% +uh so if either flux is zero the overall + + + align:start position:0% +uh so if either flux is zero the overall +tra is zero because both of them are + + align:start position:0% +tra is zero because both of them are + + + align:start position:0% +tra is zero because both of them are +required to Edge the material and you + + align:start position:0% +required to Edge the material and you + + + align:start position:0% +required to Edge the material and you +end up with these sort of saturating + + align:start position:0% +end up with these sort of saturating + + + align:start position:0% +end up with these sort of saturating +type of Curves here's for a chemical + + align:start position:0% +type of Curves here's for a chemical + + + align:start position:0% +type of Curves here's for a chemical +flux of 0. five uh as I increase the ion + + align:start position:0% +flux of 0. five uh as I increase the ion + + + align:start position:0% +flux of 0. five uh as I increase the ion +flux you increase the etch rate until + + align:start position:0% +flux you increase the etch rate until + + + align:start position:0% +flux you increase the etch rate until +some point it sort of saturates and it's + + align:start position:0% +some point it sort of saturates and it's + + + align:start position:0% +some point it sort of saturates and it's +no longer a function of of ion flux and + + align:start position:0% +no longer a function of of ion flux and + + + align:start position:0% +no longer a function of of ion flux and +that's it's limited by then by the + + align:start position:0% +that's it's limited by then by the + + + align:start position:0% +that's it's limited by then by the +chemical process so you have a series of + + align:start position:0% +chemical process so you have a series of + + + align:start position:0% +chemical process so you have a series of +the saturating curves it sort of looks + + align:start position:0% +the saturating curves it sort of looks + + + align:start position:0% +the saturating curves it sort of looks +like transistor characteristics because + + align:start position:0% +like transistor characteristics because + + + align:start position:0% +like transistor characteristics because +you have two things controlling it uh + + align:start position:0% +you have two things controlling it uh + + + align:start position:0% +you have two things controlling it uh +both the chemical flux and the ionic + + align:start position:0% + + + + align:start position:0% + +flux um so basically this is that same + + align:start position:0% +flux um so basically this is that same + + + align:start position:0% +flux um so basically this is that same +plot I just showed the edge rate tends + + align:start position:0% +plot I just showed the edge rate tends + + + align:start position:0% +plot I just showed the edge rate tends +to saturate when one component gets too + + align:start position:0% +to saturate when one component gets too + + + align:start position:0% +to saturate when one component gets too +large relative to the other so you're + + align:start position:0% +large relative to the other so you're + + + align:start position:0% +large relative to the other so you're +always rate limited by the slower of the + + align:start position:0% +always rate limited by the slower of the + + + align:start position:0% +always rate limited by the slower of the +two series processes either the chemical + + align:start position:0% +two series processes either the chemical + + + align:start position:0% +two series processes either the chemical +etch rate or the ionic edch rate this is + + align:start position:0% +etch rate or the ionic edch rate this is + + + align:start position:0% +etch rate or the ionic edch rate this is +a very generalized approach again it can + + align:start position:0% +a very generalized approach again it can + + + align:start position:0% +a very generalized approach again it can +be broadly applicable and you can use it + + align:start position:0% +be broadly applicable and you can use it + + + align:start position:0% +be broadly applicable and you can use it +to fit um a lot of of different uh Edge + + align:start position:0% +to fit um a lot of of different uh Edge + + + align:start position:0% +to fit um a lot of of different uh Edge +models with again with relatively small + + align:start position:0% +models with again with relatively small + + + align:start position:0% +models with again with relatively small +number of parameters maybe three to four + + align:start position:0% + + + + align:start position:0% + +parameters on slide 29 I'm showing a + + align:start position:0% +parameters on slide 29 I'm showing a + + + align:start position:0% +parameters on slide 29 I'm showing a +speedy simulation again where we have + + align:start position:0% +speedy simulation again where we have + + + align:start position:0% +speedy simulation again where we have +equal chemical and ionic components and + + align:start position:0% +equal chemical and ionic components and + + + align:start position:0% +equal chemical and ionic components and +you notice what you get is reasonably + + align:start position:0% +you notice what you get is reasonably + + + align:start position:0% +you notice what you get is reasonably +anisotropic etching there's a little bit + + align:start position:0% +anisotropic etching there's a little bit + + + align:start position:0% +anisotropic etching there's a little bit +of lateral etching here down at the + + align:start position:0% +of lateral etching here down at the + + + align:start position:0% +of lateral etching here down at the +bottom um and why is that well because + + align:start position:0% +bottom um and why is that well because + + + align:start position:0% +bottom um and why is that well because +in order to continue etching you need an + + align:start position:0% +in order to continue etching you need an + + + align:start position:0% +in order to continue etching you need an +ion flux to remove the inhibitor layer + + align:start position:0% +ion flux to remove the inhibitor layer + + + align:start position:0% +ion flux to remove the inhibitor layer +uh or whatever it is and that ion flux + + align:start position:0% +uh or whatever it is and that ion flux + + + align:start position:0% +uh or whatever it is and that ion flux +tends to be very vertical uh because we + + align:start position:0% +tends to be very vertical uh because we + + + align:start position:0% +tends to be very vertical uh because we +have a large n value in this case and so + + align:start position:0% +have a large n value in this case and so + + + align:start position:0% +have a large n value in this case and so +the sidewall inhibitor is not removed + + align:start position:0% +the sidewall inhibitor is not removed + + + align:start position:0% +the sidewall inhibitor is not removed +the inhibitor layer is not removed on + + align:start position:0% +the inhibitor layer is not removed on + + + align:start position:0% +the inhibitor layer is not removed on +the sidewalls but it's only removed on + + align:start position:0% +the sidewalls but it's only removed on + + + align:start position:0% +the sidewalls but it's only removed on +the flat surfaces if you change this end + + align:start position:0% +the flat surfaces if you change this end + + + align:start position:0% +the flat surfaces if you change this end +direction you'll start to see a little + + align:start position:0% +direction you'll start to see a little + + + align:start position:0% +direction you'll start to see a little +more lateral etching if you change the N + + align:start position:0% +more lateral etching if you change the N + + + align:start position:0% +more lateral etching if you change the N +number rather uh which that the N will + + align:start position:0% +number rather uh which that the N will + + + align:start position:0% +number rather uh which that the N will +determine sort of the angle of the + + align:start position:0% +determine sort of the angle of the + + + align:start position:0% +determine sort of the angle of the +cosine Theta to the end dependence and + + align:start position:0% +cosine Theta to the end dependence and + + + align:start position:0% +cosine Theta to the end dependence and +then the uh you'll get a little bit more + + align:start position:0% +then the uh you'll get a little bit more + + + align:start position:0% +then the uh you'll get a little bit more +um lateral etching so there's an example + + align:start position:0% +um lateral etching so there's an example + + + align:start position:0% +um lateral etching so there's an example +of uh for equal chemical and ion + + align:start position:0% + + + + align:start position:0% + +components okay so I just want to + + align:start position:0% +components okay so I just want to + + + align:start position:0% +components okay so I just want to +summarize um what we've done in chapter + + align:start position:0% +summarize um what we've done in chapter + + + align:start position:0% +summarize um what we've done in chapter +10 on plasma etching um we there's a lot + + align:start position:0% +10 on plasma etching um we there's a lot + + + align:start position:0% +10 on plasma etching um we there's a lot +of important issues some of the key ones + + align:start position:0% +of important issues some of the key ones + + + align:start position:0% +of important issues some of the key ones +we've covered are the select itivity + + align:start position:0% +we've covered are the select itivity + + + align:start position:0% +we've covered are the select itivity +with respect to the layer below you plus + + align:start position:0% +with respect to the layer below you plus + + + align:start position:0% +with respect to the layer below you plus +the selectivity with with the layer + + align:start position:0% +the selectivity with with the layer + + + align:start position:0% +the selectivity with with the layer +above you or the mask uh the + + align:start position:0% +above you or the mask uh the + + + align:start position:0% +above you or the mask uh the +directionality of the edge how much do + + align:start position:0% +directionality of the edge how much do + + + align:start position:0% +directionality of the edge how much do +you direct vert edch vertically versus + + align:start position:0% +you direct vert edch vertically versus + + + align:start position:0% +you direct vert edch vertically versus +laterally and the shape of the profile + + align:start position:0% +laterally and the shape of the profile + + + align:start position:0% +laterally and the shape of the profile +on the side + + align:start position:0% +on the side + + + align:start position:0% +on the side +wall they tend to be two components of + + align:start position:0% +wall they tend to be two components of + + + align:start position:0% +wall they tend to be two components of +etching there's a chemical one uh that + + align:start position:0% +etching there's a chemical one uh that + + + align:start position:0% +etching there's a chemical one uh that +is reactive neutral species or free + + align:start position:0% +is reactive neutral species or free + + + align:start position:0% +is reactive neutral species or free +radicals there's a physical component + + align:start position:0% +radicals there's a physical component + + + align:start position:0% +radicals there's a physical component +which is just du to the ions being + + align:start position:0% +which is just du to the ions being + + + align:start position:0% +which is just du to the ions being +accelerate towards the surface and + + align:start position:0% +accelerate towards the surface and + + + align:start position:0% +accelerate towards the surface and +reacting or sputtering off um components + + align:start position:0% +reacting or sputtering off um components + + + align:start position:0% +reacting or sputtering off um components +from the wafer + + align:start position:0% +from the wafer + + + align:start position:0% +from the wafer +these can be completely independent and + + align:start position:0% +these can be completely independent and + + + align:start position:0% +these can be completely independent and +then we use the linear model or they can + + align:start position:0% +then we use the linear model or they can + + + align:start position:0% +then we use the linear model or they can +act in in a series in a synergistic + + align:start position:0% +act in in a series in a synergistic + + + align:start position:0% +act in in a series in a synergistic +matter uh Manner and what we would use + + align:start position:0% +matter uh Manner and what we would use + + + align:start position:0% +matter uh Manner and what we would use +the the last Model that we showed uh + + align:start position:0% +the the last Model that we showed uh + + + align:start position:0% +the the last Model that we showed uh +topography on the wafer uh can really + + align:start position:0% +topography on the wafer uh can really + + + align:start position:0% +topography on the wafer uh can really +increase the selectivity + + align:start position:0% +increase the selectivity + + + align:start position:0% +increase the selectivity +requirements um it makes the patterning + + align:start position:0% +requirements um it makes the patterning + + + align:start position:0% +requirements um it makes the patterning +of fine features and stopping on thin + + align:start position:0% +of fine features and stopping on thin + + + align:start position:0% +of fine features and stopping on thin +layers very difficult uh of course + + align:start position:0% +layers very difficult uh of course + + + align:start position:0% +layers very difficult uh of course +lithography is impacted as well by the + + align:start position:0% +lithography is impacted as well by the + + + align:start position:0% +lithography is impacted as well by the +presence of topography because of the + + align:start position:0% +presence of topography because of the + + + align:start position:0% +presence of topography because of the +depth of focus but all modern processes + + align:start position:0% +depth of focus but all modern processes + + + align:start position:0% +depth of focus but all modern processes +seek to minimize topography so people + + align:start position:0% +seek to minimize topography so people + + + align:start position:0% +seek to minimize topography so people +have moved away from uh field oxides + + align:start position:0% +have moved away from uh field oxides + + + align:start position:0% +have moved away from uh field oxides +that go up or that go down you want fil + + align:start position:0% +that go up or that go down you want fil + + + align:start position:0% +that go up or that go down you want fil +oxide that's completely flat with the + + align:start position:0% +oxide that's completely flat with the + + + align:start position:0% +oxide that's completely flat with the +surface so you you see shallow trench + + align:start position:0% +surface so you you see shallow trench + + + align:start position:0% +surface so you you see shallow trench +isolation um there are uh special + + align:start position:0% +isolation um there are uh special + + + align:start position:0% +isolation um there are uh special +highdensity plasma eters have been + + align:start position:0% +highdensity plasma eters have been + + + align:start position:0% +highdensity plasma eters have been +developed to use uh chemicals like hbr + + align:start position:0% +developed to use uh chemicals like hbr + + + align:start position:0% +developed to use uh chemicals like hbr +chlorine and oxygen combined together + + align:start position:0% +chlorine and oxygen combined together + + + align:start position:0% +chlorine and oxygen combined together +specifically for gate etching to control + + align:start position:0% +specifically for gate etching to control + + + align:start position:0% +specifically for gate etching to control +the selectivity so you can stop on the + + align:start position:0% +the selectivity so you can stop on the + + + align:start position:0% +the selectivity so you can stop on the +gate dialectric and to control the shape + + align:start position:0% +gate dialectric and to control the shape + + + align:start position:0% +gate dialectric and to control the shape +of the sidewall profile at the same time + + align:start position:0% +of the sidewall profile at the same time + + + align:start position:0% +of the sidewall profile at the same time +you minimize damage to the underlying um + + align:start position:0% +you minimize damage to the underlying um + + + align:start position:0% +you minimize damage to the underlying um +structures and the underlying gate + + align:start position:0% +structures and the underlying gate + + + align:start position:0% +structures and the underlying gate +oxide the uh models I've talked about + + align:start position:0% +oxide the uh models I've talked about + + + align:start position:0% +oxide the uh models I've talked about +here for etching are fairly uh what I + + align:start position:0% +here for etching are fairly uh what I + + + align:start position:0% +here for etching are fairly uh what I +would call + + align:start position:0% +would call + + + align:start position:0% +would call +empirical uh if you want more predictive + + align:start position:0% +empirical uh if you want more predictive + + + align:start position:0% +empirical uh if you want more predictive +or more physically accurate models of + + align:start position:0% +or more physically accurate models of + + + align:start position:0% +or more physically accurate models of +plasma etching uh uh Professor swin used + + align:start position:0% +plasma etching uh uh Professor swin used + + + align:start position:0% +plasma etching uh uh Professor swin used +to teach class I'm not sure he's + + align:start position:0% +to teach class I'm not sure he's + + + align:start position:0% +to teach class I'm not sure he's +presently teaching it on really on all + + align:start position:0% +presently teaching it on really on all + + + align:start position:0% +presently teaching it on really on all +the details of plasma etching is an + + align:start position:0% +the details of plasma etching is an + + + align:start position:0% +the details of plasma etching is an +entire field in and of itself we've only + + align:start position:0% +entire field in and of itself we've only + + + align:start position:0% +entire field in and of itself we've only +been able to give it two lectures and + + align:start position:0% +been able to give it two lectures and + + + align:start position:0% +been able to give it two lectures and +one chapter of your textbook um so these + + align:start position:0% +one chapter of your textbook um so these + + + align:start position:0% +one chapter of your textbook um so these +models while helpful to people uh that + + align:start position:0% +models while helpful to people uh that + + + align:start position:0% +models while helpful to people uh that +we have now you know people to to these + + align:start position:0% +we have now you know people to to these + + + align:start position:0% +we have now you know people to to these +topography simulators like Speedy it's + + align:start position:0% +topography simulators like Speedy it's + + + align:start position:0% +topography simulators like Speedy it's +not going to give you the same level of + + align:start position:0% +not going to give you the same level of + + + align:start position:0% +not going to give you the same level of +uh chemical understanding if you had a + + align:start position:0% +uh chemical understanding if you had a + + + align:start position:0% +uh chemical understanding if you had a +full-blown model of the etching again + + align:start position:0% +full-blown model of the etching again + + + align:start position:0% +full-blown model of the etching again +it's it's fairly empirical we're fitting + + align:start position:0% +it's it's fairly empirical we're fitting + + + align:start position:0% +it's it's fairly empirical we're fitting +Curves in in speedy and we're fitting + + align:start position:0% +Curves in in speedy and we're fitting + + + align:start position:0% +Curves in in speedy and we're fitting +the shape but gives you some idea of + + align:start position:0% +the shape but gives you some idea of + + + align:start position:0% +the shape but gives you some idea of +what's really go of what's going on if + + align:start position:0% +what's really go of what's going on if + + + align:start position:0% +what's really go of what's going on if +you want more details uh there are other + + align:start position:0% +you want more details uh there are other + + + align:start position:0% +you want more details uh there are other +more detailed classes um you can take + + align:start position:0% +more detailed classes um you can take + + + align:start position:0% +more detailed classes um you can take +okay before we finish up let me just + + align:start position:0% +okay before we finish up let me just + + + align:start position:0% +okay before we finish up let me just +remind people if you came in late that + + align:start position:0% +remind people if you came in late that + + + align:start position:0% +remind people if you came in late that +um we have set the schedule uh after + + align:start position:0% +um we have set the schedule uh after + + + align:start position:0% +um we have set the schedule uh after +today is Thanksgiving there is no that's + + align:start position:0% +today is Thanksgiving there is no that's + + + align:start position:0% +today is Thanksgiving there is no that's +a holiday there's no class next week + + align:start position:0% +a holiday there's no class next week + + + align:start position:0% +a holiday there's no class next week +we'll talk about suicides and and novel + + align:start position:0% +we'll talk about suicides and and novel + + + align:start position:0% +we'll talk about suicides and and novel +gate materials after that we'll talk + + align:start position:0% +gate materials after that we'll talk + + + align:start position:0% +gate materials after that we'll talk +about strange silic and then you guys + + align:start position:0% +about strange silic and then you guys + + + align:start position:0% +about strange silic and then you guys +start talking I've picked the first four + + align:start position:0% +start talking I've picked the first four + + + align:start position:0% +start talking I've picked the first four +speakers here for the reports you have + + align:start position:0% +speakers here for the reports you have + + + align:start position:0% +speakers here for the reports you have +to speak for 16 minutes and then I have + + align:start position:0% +to speak for 16 minutes and then I have + + + align:start position:0% +to speak for 16 minutes and then I have +three questions of uh three U minutes + + align:start position:0% +three questions of uh three U minutes + + + align:start position:0% +three questions of uh three U minutes +for questions and answers on the seventh + + align:start position:0% +for questions and answers on the seventh + + + align:start position:0% +for questions and answers on the seventh +and on the 9th these are the speak + + align:start position:0% +and on the 9th these are the speak + + + align:start position:0% +and on the 9th these are the speak +people speaking on the 9th if you're + + align:start position:0% +people speaking on the 9th if you're + + + align:start position:0% +people speaking on the 9th if you're +doing a written report you must bring it + + align:start position:0% +doing a written report you must bring it + + + align:start position:0% +doing a written report you must bring it +to class on Thursday December 9th that's + + align:start position:0% +to class on Thursday December 9th that's + + + align:start position:0% +to class on Thursday December 9th that's +the last you can hand it in and this + + align:start position:0% +the last you can hand it in and this + + + align:start position:0% +the last you can hand it in and this +will be posted this list uh on on the + + align:start position:0% +will be posted this list uh on on the + + + align:start position:0% +will be posted this list uh on on the +website okay thanks + + align:start position:0% +website okay thanks + + + align:start position:0% +website okay thanks +great \ No newline at end of file diff --git a/A6FOBdtbcz4.txt b/A6FOBdtbcz4.txt new file mode 100644 index 0000000000000000000000000000000000000000..417d9cf7027ad9517f9f1da7bb24f49ffd07b369 --- /dev/null +++ b/A6FOBdtbcz4.txt @@ -0,0 +1,2206 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Now what I'm going +to do is, I'm going to turn + +and start producer theory, OK, +which will not be in the exam, + +but be the next subject +to the course. + +OK, and we're going to spend a +little bit longer on this. + +So what we've been doing so +far is saying, look, we + +introduced the course with +supply and demand curves, + +elasticities, all that. + +Hint, all that's on +the exam too. + +OK, and all that. + +Then we say, well gee, +where do supply and + +demand curves come from? + +Well, demand curves come from +utility maximization. + +And we talked about how where +indifference curves come from, + +how the tangency with the budget +constraints leads to + +the demand curve. + +That's where demand +curves come from. + +We talked about what underlies +demand curves is income and + +substitution effects. + +OK, now let's come +to supply curves. + +What underlies supply curves? + +Now on the one hand, this will +be much easier than demand + +curves, because a lot of +the logic is the same. + +So we can march more quickly +through the analysis, because + +it's basically the same kind +of tangency of curves with + +straight lines that yield supply +curves that we've seen + +with consumer theory. + +On the other hand, supply +curves are a ton harder, + +because now we don't +just have the + +price as given to consumers. + +The suppliers actually +make up the price. + +With consumers, we said the +price -- you just went to the + +store. you're given a price. + +And you choose what to +buy at those prices. + +Well, who set those prices? + +Producers do. + +And that's what determines the +underlying supply curve. + +So life gets a little bit more +difficult with producers. + +And that's why I'll probably +spend about twice as many + +lectures talking about producer +theory as we've spent + +talking about consumer theory. + +Now, let's go to the basics. + +The basics are, just as we had +consumers making decisions, we + +thought of a consumer as +somebody choosing across a + +bundle of goods, pizza versus +movies, now we're going to + +think of a producer very simply +as a black box, where + +inputs go in and outputs +come out. + +So think of the firm. + +Let's think of a firm, +a producer, as + +just some black box. + +We're literally thinking +a flow chart. + +You've got inputs that go in +and outputs that come out. + +And that black box, that firm, +just as individuals have a + +simple goal which is to maximize +their utility, + +producers have a simple +goal which is to + +maximize their profits. + +And profits are defined as +revenue minus cost. OK? + +Producers are these black boxes, +where their goal is to + +maximize their profits, which is +revenue minus cost. And the + +key to maximizing profits +is efficient production. + +The key to maximizing profits +is going to be to produce + +goods as efficiently +as possible. + +OK, so profit maximization +requires production + +efficiency. + +To maximize your profits, you +need to produce as efficiently + +as possible. + +Now, you might ask yourself, +gee, I can read about all + +these companies that have +executive corporate jets, and + +the guys in these lavish +lifestyles, and that doesn't + +seem very efficient +production. + +I'll come back to that. + +OK, in a couple of lectures, +we'll talk about do firms + +actually maximize profits, and +whether they do or not. + +But for now, let's take as +a given that they do. + +OK, just as it is a given that +consumers maximize utility, + +let's take as a given that firms +maximize their profits. + +OK? + +Now, to decide how to +efficiently produce goods, + +we're going to turn +and today discuss + +firm production functions. + +OK, today, we'll focus on +production functions. + +That's essentially the +technology by which a firm + +takes inputs, or what we call +factors of production, and + +turns them into outputs, +is through + +this production function. + +So just like your utility +function is a tool for which + +we take bundles of goods and +turn them into happiness, a + +production function is a tool +for which we take bundles of + +inputs and turn them +into outputs. + +OK, but something that's a +little easier to understand + +this, you could think of a +factory where stuff comes in, + +and think of a belt, a +mechanical belt, going through + +and stuff goes in and other +stuff comes out. + +You could think of that +production function. + +We're going to think about two +different kinds of inputs that + +firms are going to use. + +Once again, to make life easy, +we're going to assume firms + +only use two kinds of inputs. + +Later, we'll expand this, but +from mostly intuition you can + +get from thinking about +this-- two kinds of + +inputs, labor and capital. + +Labor and capital are the two +kinds of inputs firms use. + +Labor is clear. + +It's just hours of labor, +hours of work. + +OK? + +It's just hours of work +in production. + +Capital is a lot trickier. + +And we'll spend a lot of time +this semester struggling with + +what capital really means. + +Basically for now, think of +capital as everything else + +that goes into production, the +machines, the buildings, the + +land, everything. + +Think of capital as everything +else that goes into + +production. + +So basically, when you produce +stuff, you produce it with + +workers working with stuff. + +Capital's the stuff. + +Now, this capital is sort of a +composite of everything else + +that goes into production. + +And once again, we'll add some +more detail on this later. + +OK, and the output is +some output, q. + +That's the units +of production. + +That's the output that is +produced by the firm. + +So basically, we can think of a +production function is q is + +some function of l and k. + +That's a production function, +that the output you produce as + +your firm-- + +and by the way, we're going to +use little q to represent a + +firm's output, and big Q to +represent market output. + +OK, so little q, and if I slip +in this, yell at me, OK? + +But we're going to try to +consistently use little q to + +represent a given firm's output, +and big Q to be the + +market's output-- + +So little q is some function of +the amount of workers you + +have and the amount of +capital you use. + +Now, the important distinction +we're going to make here is + +between variable versus +fixed inputs. + +Variable versus fixed inputs +is an important distinction + +we're going to draw. + +Variable inputs are inputs that +are easily changed, like + +how many hours somebody works. + +In principle, you could just +have some work five hours one + +day, one hour the next day, 10 +hours the day after that. + +It's easy to change +hours of work. + +So that's a variable input. + +Fixed inputs are things which +are harder to change quickly, + +like the size of the building +that the workers + +are building in. + +Once that building's built, it's +pretty hard to change it. + +You can't like lop off 2/3 of it +on one day and add it back + +the next day. + +OK, that's more of +the fixed inputs. + +And this will lead to a critical +distinction for + +production theory, which +is the short run + +versus the long run. + +The short run versus +the long run. + +The long run is the +period over which + +all inputs are variable. + +The short run is a period over +which some inputs are fixed. + +Let me say it again, it's +very important. + +The short run is the +period over which + +some inputs are fixed. + +The long run is the +period over which + +all inputs are variable. + +Now, what does that mean? + +I can't tell you. + +OK? + +I can tell you that, clearly, +tomorrow is the short run. + +Clearly, you can't vary all +your inputs over one day. + +And probably next month +is the short run. + +And probably even next year +is the short run. + +There's a lot of inputs that it +takes more than a month to + +change, or a year to change. + +On the other hand, 10 years from +now is almost certainly + +the long run. + +There's very few inputs to +production you can't change + +over a 10-year period. + +So we know a day are +the short run. + +And we know 10 years +is the long run. + +We don't really know where +the transition is, but in + +substance that doesn't +matter for you guys. + +What matters is the definition +of short run, long run. + +When someone asks you what the +long run is, you say it's the + +period of time over which +all inputs are variable. + +That's what matters. + +So it doesn't matter if +you define it in days + +or months or years. + +It's a theoretical concept, +which the break from the short + +run to the long run is the break +between when some inputs + +are fixed and all inputs +are variable. + +OK? + +Now of course, once again +this is tricky. + +And economists recognize +this subtlety. + +A lot of times, economists will +talk about quasi-fixed + +factors of production, which are +things which could change + +in between the short run +and the long run. + +So for instance, take labor. + +OK, we'll talk about labor as a +variable unit of production + +you can change in +the short run. + +But in fact, we know in +practice you can't. + +Most jobs, you can't ask the +guys to come for an hour one + +day, and 10 hours the next day, +five hours the day after + +that, maybe some jobs like +hourly construction. + +But most jobs you guys will +have, OK, your labor isn't + +that variable. + +We're typically on some kind of + +reasonably set work schedule. + +Now that work schedule +can evolve. + +OK, but it can't change +day by day. + +None of us are going to have +jobs where they're going to + +say, look, work two hours +today, 12 hours the + +next day, et cetera. + +OK, we're all going to have +jobs with a fairly smooth + +distribution. + +There'll be peaks and valleys, +but a fairly smooth + +distribution of our +labor effort. + +So really, truly, there's very +few inputs which are truly + +perfectly variable. + +OK? + +Just like there are no inputs +which are truly perfectly + +fixed, but for the purposes of +this model, let's think about + +labor as a variable input. + +Let's think about labor as being +like hourly labor, like + +hourly construction, OK? + +And let's think about capital as +being a fixed input, like a + +building that you can't pare +down or rebuild overnight, but + +over a 10-year period you can. + +OK? + +Questions about that? + +Once again, we talked about +simplifying assumptions at the + +beginning of the semester. + +This is our set of simplifying +assumptions. + +Simplifying assumptions are that +firms produce goods with + +two inputs, labor and capital, +that labor is variable, which + +means you can change it minute +to minute or day to day, and + +capital is fixed, which means +you can only change + +it in the long run. + +OK? + +All right, so armed with that, +let's now talk about how firms + +make short-run production +decisions. + +And once again, these are +a lot of assumptions. + +But at the end of the day, I'm +going to be able to teach you + +in a couple of lectures how +firms make decisions. + +And I'm going to be +about 80% right. + +So that's pretty good. + +OK, so there are some +assumptions, but we're going + +to go a long way with +these assumptions. + +So let's start by considering +the short run, and considering + +that period of time over +which labor is variable + +but capital is fixed. + +Labor is variable but +capital is fixed. + +That is, you have a given plant, +but you can adjust how + +many workers you use every +day in that plant. + +And now the firm has to decide, +given that that plant + +exists, how many workers +should I hire + +to produce my good? + +How many workers should I +hire to produce my good? + +And the key concept that's going +to determine that is + +something we'll call the +marginal product of labor, + +which is the change in total +output resulting from the next + +unit of labor used-- + +that is, delta q, delta l-- + +is the marginal product +of labor. + +It's going to be the change in +total output from another unit + +of labor, once again holding +capital constant because + +that's fixed. + +So really, it's really at a +given k bar, but that's + +implicit in the fact +it's the short run. + +So the given level of capital, +what is the change in output + +for another unit of labor? + +And once we get to the short +run, I shouldn't + +have to write this. + +If I tell you short run, you +should know this is true. + +But technically, we would +write that out. + +Now, what we're going to do here +is we're typically going + +to assume this-- + +hint, hint-- + +if you're comfortable with +consumer theory, this is like + +marginal utility. + +Marginal product is like +marginal utility. + +Just as the marginal utility was +your utility from another + +unit of one good, holding the +other good fixed, marginal + +product is the marginal +production from another unit + +of an input, holding the +other input fixed. + +So just sort of a parallel +to keep in mind. + +And just as we've assumed and +discussed the intuition for + +diminishing marginal utility, +we're going to typically + +assume diminishing +marginal product. + +So we're going to assume +diminishing marginal product. + +That is, from a given level of +labor, the next worker you add + +increases your total product by +less than the previous one. + +Now once again, just like we +have a non- satiation rule in + +utility, we're not going +to say the next + +worker doesn't help. + +Every worker helps. + +But every worker helps less and +less and less, just like + +every pizza means less and +less and less to you. + +Now, the trick here, once again, +this is like consumer + +theory, only more subtle. + +With consumer theory, it's +pretty clear that once you had + +one pizza, clearly, the second +pizza means less. + +And once you've seen one movie, +your first-place prize, + +the movie you most want to see, +clearly the next movie + +you want to see means +a little bit less. + +Producer theory is a +little more subtle. + +And you can imagine ranges over +which more workers help. + +They can work together. + +So that actually two workers +can do more than twice what + +one worker can do. + +And we'll talk about that. + +But we're going to focus in the +main on ranges over which + +each additional worker does +less and less and less. + +And the reason is because, +to remember, this + +is less than two-- + +Yeah? + +AUDIENCE: Is there going to +be a point where actually + +additional workers won't do +anything, because of like + +constrain to the amounts +of other inputs? + +PROFESSOR: Once again, we're not +going to get-- just like + +there's a point at which extra +pizza will make you barf-- + +OK, we're assuming we don't +get to that point. + +But yes, technically of course, +at some point more is + +not better. + +At some point, extra workers +just sit around. + +And so I agree. + +So basically, it's +a little tricky. + +You could imagine an initial +range where more + +workers would help. + +Then there's the main range +we'll focus on each additional + +worker does less and +less and less. + +And you could imagine that +running out, which is a worker + +does nothing. + +But let's just now assume +we don't get there. + +So basically, what's +the intuition? + +Now the intuition for in +utility theory, for + +diminishing marginal utility, +I thought was pretty easy, + +which is each pizza +means less. + +The intuition for why each +worker does less, I find a + +little bit harder. + +You could say, well, gee, why +should one worker do less than + +the next worker? + +Why shouldn't the next worker +do less than the first? + +And the key is this +part, that we're + +holding capital constant. + +The reason each worker does less +is because they only have + +the same amount of stuff +to work with. + +And the classic example we +use here is the example + +of digging a hole. + +You go to dig a hole and your +capital's a shovel. + +And let's say for some reason +the shovels are out, so you + +can't get another shovel +for a while. + +OK, so there's one shovel. + +So you have one worker digging +a hole, then the next worker + +comes along and that's where +he can help because he can + +spell the first worker. + +And maybe the next worker's just +as good because he can + +work more hours, but probably +it's a little bit less good. + +But certainly by the time you +add a fourth and a fifth and a + +sixth person, with one shovel, +they probably each help + +because they can rotate +and rest each other. + +But certainly the sixth person +is not going to help dig the + +hole as much as that second +person did, or the third, or + +fourth, or fifth person, because +only one shovel. + +So they can share a little +bit and share the + +burden a little bit. + +But at some point each +additional worker helps less + +because they have to share +the same shovel. + +So that's what diminishing +marginal product is, because + +capital's fixed. + +With a certain amount of capital +to work with, each + +additional worker just +can't help as + +much as the one before. + +Now eventually, you can +add more shovels. + +And you could have +wheelbarrows. + +So some people could run the +wheelbarrows, some people + +could run the shovels. + +But that's the long run. + +In the short run, there's the +one shovel, so each additional + +worker does less good. + +And that's the intuition. + +Once again, not as clean as with +consumption, where it's + +easy to see each additional +pizza is worth less, because + +you could imagine the second +worker might actually help. + +They could rest, et cetera, +and you could imagine + +eventually the ninth worker does +nothing because there's + +nothing left to do. + +But let's focus on that range +where it's intuitive. + +We're staying between the second +and sixth worker, which + +is when a worker would help, +but they help less + +and less and less. + +OK, and that's the diminishing +marginal product. + +Questions about that? + +That's short-run production. + +And we're going to come +back to this. + +But I just want to introduce +these concepts. + +Now let's talk about long-run +production. + +Now in the long run, all +inputs are variable. + +That's how we defined +the long run. + +So now a firm doesn't just +choose how many workers to + +hire, or how many hours +of labor to buy. + +It chooses both l and k, and +has to trade them off, just + +like you chose both pizzas +and movies and had + +to trade them off. + +So the long-run production +theory is the same, basically + +the same mechanics, +as utility theory. + +There's a production function. + +You have two inputs. + +You trade them off. + +Just like you're a consumer. + +You have two goods to consume. + +You trade them off. + +The difference is going to be +that ultimately production is + +going to self-- + +the difference is, when you +decide how to trade them off + +as a consumer, you're given +a budget constraint. + +The difference with production +is the budget constraint is + +going to be itself determined +by the same system. + +So you're not only going to +develop your production + +function, but you're going to +develop your budget constraint + +and, you're going +to decide both. + +It's a little bit funky +but we'll get to it. + +But for now, let's just think +about the parallels to + +consumer theory, and think about +a production function + +which is q-- + +little q-- + +is the square root +of k times l. + +That same functional form I used +with pizza and movies, + +where utility is the square root +of pizza times movies. + +Now I'm going to say what you +produce of your good is the + +square root of k times l. + +Now let's go to figure 8-3. + +And what we see here is, if +you're trading off k and l and + +deciding to produce, then you +get what's called isoquants. + +Isoquants are the parallel +to indifference curves. + +Once again, this is all +the same mechanics. + +Just as there were sets of goods +across which you were + +indifferent, two pizzas and one +movie versus one pizza and + +two movies. + +Isoquants are sets of +inputs along which + +production is the same. + +So along a given isoquant, +q is fixed. + +Each of those isoquants is a +different level of q, but they + +show how you can vary k and l +to get the same amount of q. + +So producing q equals +square root of 2. + +I can use two units of capital +and one unit of labor, or one + +unit of capital and +two of labor. + +So I can choose lots of +combinations of k and l along + +that isoquant to produce a +given amount of output. + +And isoquants have all the +same features as in + +indifference curves. + +The further out the better +because you're producing more. + +They can't cross. + +All the same set of things we +have in the indifference + +curves are true with +isoquants as well. + +And they slope downwards because +there's a trade off + +between capital and labor. + +Now, what's going to determine +the slope of an isoquant? + +Can someone tell me +what determines + +the slope of an isoquant? + +What determines if isoquants +are steep or shallow? + +Well, what determines the slope +of a indifference curve? + +Yes, go ahead. + +AUDIENCE: It's based on the +ratio of how much labor is + +worth versus capital? + +PROFESSOR: Right, and what +do we call that? + +What determines how much they're +worth from each other? + +What determines the slope +of a indifference curve? + +The marginal rate of +substitution, it was the + +substitutability +between goods. + +Likewise, the substitutability +between labor and capital will + +determine the slope of +these isoquants. + +So to see an example, let's do +an extreme example here. + +Let's consider goods that are +perfectly substitutable. + +So like, I don't know, just like +a Harvard undergraduate + +and a beanie baby. + +OK, perfectly substitutable. + +Figure 8-4a shows the +case of perfectly + +substitutable inputs. + +In that case, you would have a +linear isoquant, because what + +that would mean is you don't +care if you have three capital + +and one labor, or three +labor and one capital. + +You don't care. + +You don't care if you have two +labor and two capital, or + +three labor and one capital, +as long as you + +get a total of four. + +That's all that matters. + +They're perfectly substitutable +inputs, which + +would say that it would be +something like q equals k plus + +l would be the case +of perfectly + +substitutable inputs. + +You don't care if it's k or l, +you just care about the total. + +That'd be perfectly +substitutable inputs. + +That would be a linear +isoquant. + +OK, on the other hand, let's +think about goods which are + +not at all substitutable like +cereal and cereal boxes. + +The cereal wouldn't be any +good unless you have a + +box to put it in. + +The box doesn't do anything +unless you have + +cereal to put in it. + +That would be like in 8-4b. + +8-4b would show you +non-substitutable inputs where + +basically, given the amount of +one input, it doesn't matter + +how much you have +of the other. + +So for example, if you take +these-- these we often call + +non-substitutable isoquants-- + +Leontief production functions. + +Leontief production function, +for Wassily Leontief, some old + +economist. + +And basically, the Leontief +production function is that + +your production, q equals the +Min of k and l, is the + +Leontief production function. + +So given how much k you have, +given you have 10 cereal + +boxes, once you have 10 chunks +of cereal, it doesn't matter + +if you have 10, 11, +12, 1 million. + +You only have 10 cereal boxes. + +So given an amount of k, then +it doesn't matter how much l + +you have. Once you get to the +amount of l you need to fill + +the cereal boxes, it doesn't +matter, and vice versa. + +So basically, they're perfectly +non-substitutable. + +So all that determines your +output is which you + +have the least of. + +OK, so substitutabilities +determine the slope of the + +isoquants and of this +production function. + +Now in general, we'll be +in between these cases. + +There'll be some +substitutability. + +Goods won't be perfectly +substitutable, but they'll be + +somewhat substitutable. + +So in general, we'll be in +between these cases. + +And more generally, just as the +slope of the indifference + +curve is the marginal rate of +substitution, the slope of the + +isoquant we will call the +marginal rate of technical + +substitution. + +The marginal rate of technical +substitution-- the rate at + +which you can substitute one +input for another in a + +production function is the +marginal rate of technical + +substitution-- + +which we'll define as delta k, +delta l for a given q bar, the + +rate at which you can +trade off k for l + +to hold q bar fixed. + +Now, as with marginal rate of +substitution, the marginal + +rate of technical substitution +will + +change along the isoquant. + +So if you go to figure 8-5, +here we've drawn a typical + +isoquant for the production +function q equals square root + +of k times l. + +So the production function +is q equals the square + +root of k times l. + +And here's a isoquant. + +This is the isoquant +of all combinations + +which produce two units. + +This is the q equals +2 isoquant. + +Now, unlike utility-- +remember utility?-- + +we said where u equals +2 was meaningless. + +Utility was an ordinal concept, + +not a cardinal concept. + +Here, quantity is meaningful. + +If you produce four, you would +have only produced twice as + +much as if you produced two. + +We can care about both the +ordinality and the cardinality + +of these outcomes. + +So we can say, what are the +combinations of inputs which + +lead you to produce two units? + +What's all these combinations +of inputs? + +So whereas you can have one unit +of labor and four units + +of capital, two of each, or four +units of labor and one + +unit of capital, all +will produce two + +units of the output. + +And what you can see is that the +marginal rate of technical + +substitution varies. + +So for instance, when we start +with four units of capital and + +one unit of labor, and we think +about adding a second + +unit of labor, then the marginal +rate of technical + +substitution is minus 2. + +That is, one unit of labor is +worth two units of capital. + +In other words, we can produce +the same amount of widgets of + +q, but if we replace two units +of capital with one unit of + +labor, so at that point we're +very capital-intensive, and + +that unit of labor +is very valuable. + +On the other hand, now if you +imagine we're down at 4-1, at + +the third point-- + +we are probably using +a, b, c-- + +now we're at the third point, +where you have we have four + +units of labor and one +unit of capital. + +Now, if you'd be willing to +give up two units of labor + +just to get one unit of capital, +that's the marginal + +rate of technical substitution +is now minus 1/2. + +When you're very +labor-intensive, you'd be + +happy to give up a lot of labor +to get a little capital. + +Once again, the principle of +diminishing marginal product, + +just like the principle of +diminishing marginal utility, + +implies that the marginal rate +of technical substitution is + +going to be falling as you +go down the isoquant. + +Just like the marginal rate of +substitution fell as you went + +down the indifference curve, the +marginal rate of technical + +substitution is going to fall +as you go down the isoquant. + +And why is this? + +Once again it's because of +this diminishing marginal + +productivity. + +That is, as you add more and +more labor, given capital, + +each unit of labor can +do less and less. + +And likewise, as you add more +and more capital, given an + +amount of workers to use it, +each unit of capital can do + +less and less. + +So it's a very different +approach, but gets you the + +same answer, which is with +consumption, each piece does + +less and less for you, but we +can see that as consumers. + +Here's the notions of labor, +each worker does less and less + +for you, holding +capital fixed. + +And each machine by the same +logic, if you have one guy in + +the hole, it doesn't +matter how many + +shovels you throw there. + +He still is only one guy. + +So each machines is doing less +and less by the same logic. + +And those diminishing marginal +products lead to this + +decreasing marginal rate of +technical substitution as you + +move along the isoquant. + +That's about the most technical +statement I'll make + +all semester. + +OK, questions about that, about +what's going on here? + +That's production theory. + +That's what you need to know +to know basically how firms + +produce things. + +Now, what we're going to do +is, now take this basic + +production theory, and turn it +into actually understanding + +how firms make decisions +on how much to produce. + +But before we do that, I want +to talk about one other + +concept, which is very important +for thinking about + +production theory. + +And it comes back to these +assumptions that we make which + +might be a little bit +unrealistic, which is the + +concept of returns to scale. + +The concept of returns +to scale. + +So here the question is, what +happens if we increase all + +inputs proportionally? + +Return to scale. + +By scale, I mean, what if we +just double everything, twice + +as much labor and twice +as much capital. + +That's an increase in scale, +increasing all inputs + +proportionally, twice as much +labor, twice as much capital, + +half as much labor, half +as much capital. + +So a change in scale is an equal +increase or decrease in + +all inputs? + +Equal proportional. + +So what happens if we increase +all inputs, increase or + +decrease proportionally? + +And this is an interesting case, +because it's like, OK, + +what if we just make the +firm half as big? + +What happens? + +Well, the answer is, +it depends on + +the production process. + +Some production processes will +exhibit what we call constant + +returns to scale. + +This is a convenient form. + +It's convenient because the way +constant returns to scale + +works is, it says that f of +2l, 2k, is equal to 2 + +times f of l, k. + +That is, if it's constant, you +can just pull the 2 out. + +Doubling the inputs leads to +doubling the outputs, which + +equals to 2q, I'll write here. + +Doubling the inputs equals +doubling the outputs. + +So if I have twice as much labor +and capital, that's the + +same as twice producing what I +had with the original labor + +and capital which will get me +twice the original production. + +That's the constant +returns to scale. + +So every time I double my firm, +I get exactly twice as + +much stuff out. + +We can contrast that with +increasing returns to scale, + +IRS, which says that f of 2l, +2k, is greater than 2 + +times f of l, k. + +Or it's greater than 2q. + +That is, when I double my firm, +I produce more than + +twice as much stuff. + +That'd be increasing +returns to scale. + +On the other hand, we could also +have decreasing returns + +to scale, which not surprisingly +means that f of + +2l, 2k, is less than 2 times +f of l, k, or less than 2q. + +That would be decreasing returns +to scale, which is + +when I double my firm I get less +than twice as much stuff. + +Can anyone give me an example or +some reason why returns to + +scale is going to be increasing +or decreasing? + +Think about firms out there. + +Give me some that, by returns to +scale, would be increasing + +or decreasing, any examples +you can think of. + +There's no right answer here. + +Yeah. + +Go ahead, on the end. + +AUDIENCE: Oh, if you're mining +something, you can only get to + +stuff at one time, so having +more equipment and more people + +doesn't mean you can +get more out of it? + +PROFESSOR: Right, so if there's +a limited resource, + +you could imagine decreasing +returns to scale. + +Good. + +What else? + +Yeah. + +AUDIENCE: If the company gets +harder to manage, that could + +be decreasing returns +to scale? + +PROFESSOR: Right, exactly. + +If you're an entrepreneur, +you've got a great idea, but + +it turns out that idea only +works if you really are + +hands-on about it. + +You're not Mark Zuckerberg, who +can just farm the thing + +out, it's really your idea. + +And you've got to be there. + +Then after it expands and +you lose control of the + +production, it might not be as +effective because you're not + +there making it happen. + +Any ideas why return-- + +Yeah. + +AUDIENCE: If you or +[UNINTELLIGIBLE] + +PROFESSOR: So that's +an example of + +increasing returns to scale. + +Increasing returns to scale +would be, gee, maybe if I'm + +bigger, I can get a better +deal on the inputs. + +But that's not quite right, +because we haven't really got + +into prices yet. + +I'm looking-- that's really +a market response-- + +I'm looking for a more +technological story, a + +technological story of +increasing returns. + +Go ahead. + +AUDIENCE: If you're bigger, you +can hire a specialist to + +do work, like a manager +who can [INAUDIBLE] + +PROFESSOR: Exactly. + +So it's the opposite, which is, +let's say you have an idea + +which is pretty good, but +in fact it's replicable. + +And right now, you're trying +to manage some guys. + +And then all of a sudden, when +you get twice as big, you + +bring other people in who can +effectively replicate your + +idea, and really expand it +in a very effective way. + +You can have increasing +returns to scale. + +Now, so an example of what that +looks like, if you go to + +the last page in the handout, +figure 8-6a shows constant + +returns to scale. + +So let's start with +8-6a, that's + +constant returns to scale. + +So here-- and these are +from the textbook-- + +for example, when we doubled the +inputs from 100 labor, 100 + +capital, to 200 labor, 200 +capital, you doubled output. + +Those are constant returns +to scale isoquants. + +The last page shows +decreasing and + +increasing returns to scale. + +So for instance, tobacco is an +example of decreasing returns + +to scale, because there's only +so much leaf that you have + +that you can produce. + +So here, when you double the +inputs from 100 to 200, your + +output only goes from +100 to 142. + +OK, and if you want to double +the 200 units, you've got to + +go way the heck up +there on inputs. + +On the other hand, primary metal +production is something + +where you can have increasing +returns to scale, because + +there's such high costs of +building a plant that once + +it's built, so just like I said, +gee, in fact that second + +digger of the hole might +actually make it more + +productive. + +Once that plant's built, there's +one worker banging + +around the plant, a second +worker adds a huge amount to + +productivity because they +can specialize. + +Basically, increasing returns to +scale is going to come from + +specialization. + +So if you build this big plant +to build primary, to build + +steel, one worker in that plant +is no good, because he's + +got to pour the steel, +then run over and + +cool it down, et cetera. + +Once you have two, they can +specialize, and three, they + +can specialize more. + +You might think of something +like that would have + +increasing returns to scale +through specialization. + +And that's illustrated here, +where doubling the inputs + +actually leads to more than +doubling the output. + +Now we're going to talk +about all these cases. + +Typically, economists are +suspicious of increasing + +returns to scale. + +Anybody, anybody who ever has an +IPO, whoever starts a firm + +will always tell you +that they have + +increasing returns to scale. + +Well, we say, I've got a great +idea and the bigger, the more, + +the better it's going to be. + +And they're generally wrong. + +Generally, we think of +increasing returns to scale as + +being like a free lunch. + +And we don't like free lunches, +we economists. + +We think, gee, if it's really +increasing returns to scale, + +you would have already +expanded there. + +OK, if it's really such a good +idea to get bigger, why aren't + +you bigger already? + +Now, it doesn't mean you can-- + +Yeah. + +AUDIENCE: Well, they +need capital. + +PROFESSOR: Well, they need +capital, and so that would be + +their argument. + +And that's great. + +And typically, they're wrong. + +But that would be why you would +argue that they need + +capital to get bigger. + +So typically, we like decreasing +returns to scale. + +That's going to be our +sort of default + +assumption of the world. + +In other words, here's a way to +think about it, think about + +we're dealing with mature firms. +We're modeling, for + +instance, mature firms. + +We think that for mature firms, +at least, there's not + +increasing returns to scale, +because in a mature firm they + +would have hit that +point already. + +Now they're on the +decreasing part. + +So that's where we're +going to focus for + +the rest of the semester. + +OK, let me stop there. + +And good luck tomorrow night. + +And we'll come back +to talk more about + +production on Wednesday. \ No newline at end of file diff --git a/AWU3lTs9KJA.txt b/AWU3lTs9KJA.txt new file mode 100644 index 0000000000000000000000000000000000000000..03e88379da0474166f466adbbfe66df7d7b73fb7 --- /dev/null +++ b/AWU3lTs9KJA.txt @@ -0,0 +1,10267 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so we have a an interesting + + align:start position:0% +ocw.mit.edu so we have a an interesting + + + align:start position:0% +ocw.mit.edu so we have a an interesting +um class today we're going to be taking + + align:start position:0% +um class today we're going to be taking + + + align:start position:0% +um class today we're going to be taking +this V curve that we've uh so + + align:start position:0% +this V curve that we've uh so + + + align:start position:0% +this V curve that we've uh so +laboriously uh set up and understood + + align:start position:0% +laboriously uh set up and understood + + + align:start position:0% +laboriously uh set up and understood +sorry about that and now we will uh + + align:start position:0% +sorry about that and now we will uh + + + align:start position:0% +sorry about that and now we will uh +subject to it to illumination um so + + align:start position:0% +subject to it to illumination um so + + + align:start position:0% +subject to it to illumination um so +that's the essence of our lecture today + + align:start position:0% +that's the essence of our lecture today + + + align:start position:0% +that's the essence of our lecture today +the diode under illumination and uh as + + align:start position:0% +the diode under illumination and uh as + + + align:start position:0% +the diode under illumination and uh as +part of today's lecture we have some + + align:start position:0% +part of today's lecture we have some + + + align:start position:0% +part of today's lecture we have some +wonderful little kits over there in the + + align:start position:0% +wonderful little kits over there in the + + + align:start position:0% +wonderful little kits over there in the +corner where we'll actually be testing + + align:start position:0% +corner where we'll actually be testing + + + align:start position:0% +corner where we'll actually be testing +IV curves of solar cells um so I hope uh + + align:start position:0% +IV curves of solar cells um so I hope uh + + + align:start position:0% +IV curves of solar cells um so I hope uh +some of you brought the computers today + + align:start position:0% +some of you brought the computers today + + + align:start position:0% +some of you brought the computers today +and if not we have some extras up here + + align:start position:0% +and if not we have some extras up here + + + align:start position:0% +and if not we have some extras up here +as well use so again just to situate + + align:start position:0% +as well use so again just to situate + + + align:start position:0% +as well use so again just to situate +ourselves you're here on fundamentals uh + + align:start position:0% +ourselves you're here on fundamentals uh + + + align:start position:0% +ourselves you're here on fundamentals uh +we're approaching the + + align:start position:0% +we're approaching the + + + align:start position:0% +we're approaching the +end of our fundamental section but we + + align:start position:0% +end of our fundamental section but we + + + align:start position:0% +end of our fundamental section but we +still have a few really important + + align:start position:0% +still have a few really important + + + align:start position:0% +still have a few really important +lectures to get through after we get + + align:start position:0% +lectures to get through after we get + + + align:start position:0% +lectures to get through after we get +through the fundamentals we'll be in a + + align:start position:0% +through the fundamentals we'll be in a + + + align:start position:0% +through the fundamentals we'll be in a +good position to understand the + + align:start position:0% +good position to understand the + + + align:start position:0% +good position to understand the +different Technologies and finally the + + align:start position:0% +different Technologies and finally the + + + align:start position:0% +different Technologies and finally the +cross cutting themes and our goal is to + + align:start position:0% +cross cutting themes and our goal is to + + + align:start position:0% +cross cutting themes and our goal is to +at least for the fundamentals to + + align:start position:0% +at least for the fundamentals to + + + align:start position:0% +at least for the fundamentals to +understand solar cell conversion + + align:start position:0% +understand solar cell conversion + + + align:start position:0% +understand solar cell conversion +efficiency which is the ratio of output + + align:start position:0% +efficiency which is the ratio of output + + + align:start position:0% +efficiency which is the ratio of output +to input energy and for most solar cells + + align:start position:0% +to input energy and for most solar cells + + + align:start position:0% +to input energy and for most solar cells +this breaks down to the following + + align:start position:0% +this breaks down to the following + + + align:start position:0% +this breaks down to the following +progression from the solar Spectrum to + + align:start position:0% +progression from the solar Spectrum to + + + align:start position:0% +progression from the solar Spectrum to +charge collection and we're going to be + + align:start position:0% +charge collection and we're going to be + + + align:start position:0% +charge collection and we're going to be +focusing on charge separation + + align:start position:0% +focusing on charge separation + + + align:start position:0% +focusing on charge separation +incorporating elements of uh either side + + align:start position:0% +incorporating elements of uh either side + + + align:start position:0% +incorporating elements of uh either side +but mostly focus on charge separation + + align:start position:0% +but mostly focus on charge separation + + + align:start position:0% +but mostly focus on charge separation +today + + align:start position:0% +today + + + align:start position:0% +today +reminding everybody of course that the + + align:start position:0% +reminding everybody of course that the + + + align:start position:0% +reminding everybody of course that the +total system efficiency is the product + + align:start position:0% +total system efficiency is the product + + + align:start position:0% +total system efficiency is the product +of each individual efficiency and if any + + align:start position:0% +of each individual efficiency and if any + + + align:start position:0% +of each individual efficiency and if any +one of these is low the efficiency for + + align:start position:0% +one of these is low the efficiency for + + + align:start position:0% +one of these is low the efficiency for +the entire system is low and since folks + + align:start position:0% +the entire system is low and since folks + + + align:start position:0% +the entire system is low and since folks +are tired of looking at this chart by + + align:start position:0% +are tired of looking at this chart by + + + align:start position:0% +are tired of looking at this chart by +now every single lecture I intend to + + align:start position:0% +now every single lecture I intend to + + + align:start position:0% +now every single lecture I intend to +introduce something new that follows a + + align:start position:0% +introduce something new that follows a + + + align:start position:0% +introduce something new that follows a +similar pattern uh does anybody + + align:start position:0% +similar pattern uh does anybody + + + align:start position:0% +similar pattern uh does anybody +recognize what this is + + align:start position:0% +recognize what this is + + + align:start position:0% +recognize what this is +about so you have over here um some H2O + + align:start position:0% +about so you have over here um some H2O + + + align:start position:0% +about so you have over here um some H2O +uh leading to an going into an oxygen + + align:start position:0% +uh leading to an going into an oxygen + + + align:start position:0% +uh leading to an going into an oxygen +evolving complex and light is coming in + + align:start position:0% +evolving complex and light is coming in + + + align:start position:0% +evolving complex and light is coming in +essentially exciting up an electron + + align:start position:0% +essentially exciting up an electron + + + align:start position:0% +essentially exciting up an electron +which is being stored in some form of + + align:start position:0% +which is being stored in some form of + + + align:start position:0% +which is being stored in some form of +chemical energy what is that + + align:start position:0% +chemical energy what is that + + + align:start position:0% +chemical energy what is that +photosynthesis right and uh just like a + + align:start position:0% +photosynthesis right and uh just like a + + + align:start position:0% +photosynthesis right and uh just like a +solar cell the photosynthetic uh uh + + align:start position:0% +solar cell the photosynthetic uh uh + + + align:start position:0% +solar cell the photosynthetic uh uh +photosynthesis uh conversion efficiency + + align:start position:0% +photosynthesis uh conversion efficiency + + + align:start position:0% +photosynthesis uh conversion efficiency +of the entire system is dictated by the + + align:start position:0% +of the entire system is dictated by the + + + align:start position:0% +of the entire system is dictated by the +efficiency of each individual part + + align:start position:0% +efficiency of each individual part + + + align:start position:0% +efficiency of each individual part +roughly it can be broken down into this + + align:start position:0% +roughly it can be broken down into this + + + align:start position:0% +roughly it can be broken down into this +little pie chart up here the total + + align:start position:0% +little pie chart up here the total + + + align:start position:0% +little pie chart up here the total +system efficiency in blue is somewhere + + align:start position:0% +system efficiency in blue is somewhere + + + align:start position:0% +system efficiency in blue is somewhere +depending on the plant somewhere between + + align:start position:0% +depending on the plant somewhere between + + + align:start position:0% +depending on the plant somewhere between +around 1% uh maybe as high as 7 or 8% + + align:start position:0% +around 1% uh maybe as high as 7 or 8% + + + align:start position:0% +around 1% uh maybe as high as 7 or 8% +depending on very specialized plants + + align:start position:0% +depending on very specialized plants + + + align:start position:0% +depending on very specialized plants +that are experts at converting sunlight + + align:start position:0% +that are experts at converting sunlight + + + align:start position:0% +that are experts at converting sunlight +into uh usable chemical energy and uh + + align:start position:0% +into uh usable chemical energy and uh + + + align:start position:0% +into uh usable chemical energy and uh +that in part is largely due to Optical + + align:start position:0% +that in part is largely due to Optical + + + align:start position:0% +that in part is largely due to Optical +losses if you can see the absorption + + align:start position:0% +losses if you can see the absorption + + + align:start position:0% +losses if you can see the absorption +spectrum of chlorophyll of the different + + align:start position:0% +spectrum of chlorophyll of the different + + + align:start position:0% +spectrum of chlorophyll of the different +types of chlorophyll here um you'll see + + align:start position:0% +types of chlorophyll here um you'll see + + + align:start position:0% +types of chlorophyll here um you'll see +large portions of the solar spectrum + + align:start position:0% +large portions of the solar spectrum + + + align:start position:0% +large portions of the solar spectrum +that go + + align:start position:0% +that go + + + align:start position:0% +that go +underutilized so um again another system + + align:start position:0% +underutilized so um again another system + + + align:start position:0% +underutilized so um again another system +that's similar to a solar cell that uh + + align:start position:0% +that's similar to a solar cell that uh + + + align:start position:0% +that's similar to a solar cell that uh +the uh total system efficiency is the + + align:start position:0% +the uh total system efficiency is the + + + align:start position:0% +the uh total system efficiency is the +product of each individual component + + align:start position:0% +product of each individual component + + + align:start position:0% +product of each individual component +going along here all right right so uh + + align:start position:0% +going along here all right right so uh + + + align:start position:0% +going along here all right right so uh +now what we're going to do is just + + align:start position:0% +now what we're going to do is just + + + align:start position:0% +now what we're going to do is just +quickly revisit the diode in the dark + + align:start position:0% +quickly revisit the diode in the dark + + + align:start position:0% +quickly revisit the diode in the dark +and construct the energy band diagram + + align:start position:0% +and construct the energy band diagram + + + align:start position:0% +and construct the energy band diagram +for p injunction in the dark uh each of + + align:start position:0% +for p injunction in the dark uh each of + + + align:start position:0% +for p injunction in the dark uh each of +you should have on your desk uh these + + align:start position:0% +you should have on your desk uh these + + + align:start position:0% +you should have on your desk uh these +sheets oh we don't have them on the + + align:start position:0% +sheets oh we don't have them on the + + + align:start position:0% +sheets oh we don't have them on the +desks we need to pass those out we need + + align:start position:0% +desks we need to pass those out we need + + + align:start position:0% +desks we need to pass those out we need +to pass those out um so we should have + + align:start position:0% +to pass those out um so we should have + + + align:start position:0% +to pass those out um so we should have +uh sheets that describe the U uh + + align:start position:0% +uh sheets that describe the U uh + + + align:start position:0% +uh sheets that describe the U uh +essentially the the equivalent circuit + + align:start position:0% +essentially the the equivalent circuit + + + align:start position:0% +essentially the the equivalent circuit +diagram uh the IV characteristics and + + align:start position:0% +diagram uh the IV characteristics and + + + align:start position:0% +diagram uh the IV characteristics and +the energy band diagram for our P + + align:start position:0% +the energy band diagram for our P + + + align:start position:0% +the energy band diagram for our P +injunction in the dark we laboriously + + align:start position:0% +injunction in the dark we laboriously + + + align:start position:0% +injunction in the dark we laboriously +filled this out last class class we're + + align:start position:0% +filled this out last class class we're + + + align:start position:0% +filled this out last class class we're +just going to refresh ourselves to make + + align:start position:0% +just going to refresh ourselves to make + + + align:start position:0% +just going to refresh ourselves to make +sure we're all on the same page and redo + + align:start position:0% +sure we're all on the same page and redo + + + align:start position:0% +sure we're all on the same page and redo +it this class right at the beginning + + align:start position:0% +it this class right at the beginning + + + align:start position:0% +it this class right at the beginning +because it's that important thank you + + align:start position:0% +because it's that important thank you + + + align:start position:0% +because it's that important thank you +thank you thank you for those who came + + align:start position:0% +thank you thank you for those who came + + + align:start position:0% +thank you thank you for those who came +to our office hours and for those who + + align:start position:0% +to our office hours and for those who + + + align:start position:0% +to our office hours and for those who +came to the recitations and we really uh + + align:start position:0% +came to the recitations and we really uh + + + align:start position:0% +came to the recitations and we really uh +tried to to get this across uh for those + + align:start position:0% +tried to to get this across uh for those + + + align:start position:0% +tried to to get this across uh for those +who are still struggling uh let's make + + align:start position:0% +who are still struggling uh let's make + + + align:start position:0% +who are still struggling uh let's make +sure that you get this uh sometime + + align:start position:0% +sure that you get this uh sometime + + + align:start position:0% +sure that you get this uh sometime +between now and say the next two weeks + + align:start position:0% +between now and say the next two weeks + + + align:start position:0% +between now and say the next two weeks +because this will feature prominently on + + align:start position:0% +because this will feature prominently on + + + align:start position:0% +because this will feature prominently on +the exam um and it's pretty important + + align:start position:0% +the exam um and it's pretty important + + + align:start position:0% +the exam um and it's pretty important +for understanding how a solar cell works + + align:start position:0% +for understanding how a solar cell works + + + align:start position:0% +for understanding how a solar cell works +so if you would uh not mind working + + align:start position:0% +so if you would uh not mind working + + + align:start position:0% +so if you would uh not mind working +directly with your partner the person + + align:start position:0% +directly with your partner the person + + + align:start position:0% +directly with your partner the person +who's sitting directly next to you uh + + align:start position:0% +who's sitting directly next to you uh + + + align:start position:0% +who's sitting directly next to you uh +let's walk through the uh diode in the + + align:start position:0% +let's walk through the uh diode in the + + + align:start position:0% +let's walk through the uh diode in the +dark and construct the energy band + + align:start position:0% +dark and construct the energy band + + + align:start position:0% +dark and construct the energy band +diagrams for the diode in the dark uh + + align:start position:0% +diagrams for the diode in the dark uh + + + align:start position:0% +diagrams for the diode in the dark uh +I'll walk you through it as soon as + + align:start position:0% +I'll walk you through it as soon as + + + align:start position:0% +I'll walk you through it as soon as +you're done maybe I'll give you uh 3 + + align:start position:0% +you're done maybe I'll give you uh 3 + + + align:start position:0% +you're done maybe I'll give you uh 3 +minutes to complete that and then we'll + + align:start position:0% +minutes to complete that and then we'll + + + align:start position:0% +minutes to complete that and then we'll +uh progress to the diode under + + align:start position:0% +uh progress to the diode under + + + align:start position:0% +uh progress to the diode under +illumination should be a lot of + + align:start position:0% + + + + align:start position:0% + +fun good I see convergence among several + + align:start position:0% +fun good I see convergence among several + + + align:start position:0% +fun good I see convergence among several +of you so let's uh move + + align:start position:0% +of you so let's uh move + + + align:start position:0% +of you so let's uh move +forward uh just to review quickly um the + + align:start position:0% +forward uh just to review quickly um the + + + align:start position:0% +forward uh just to review quickly um the +way I I typically think about it if we + + align:start position:0% +way I I typically think about it if we + + + align:start position:0% +way I I typically think about it if we +start out from the model circuit right + + align:start position:0% +start out from the model circuit right + + + align:start position:0% +start out from the model circuit right +here we have our p and Junction we have + + align:start position:0% +here we have our p and Junction we have + + + align:start position:0% +here we have our p and Junction we have +our space charge region also known as a + + align:start position:0% +our space charge region also known as a + + + align:start position:0% +our space charge region also known as a +quasi neutral region also known as the + + align:start position:0% +quasi neutral region also known as the + + + align:start position:0% +quasi neutral region also known as the +depletion zone so we have this uh region + + align:start position:0% +depletion zone so we have this uh region + + + align:start position:0% +depletion zone so we have this uh region +right here uh that represents the space + + align:start position:0% +right here uh that represents the space + + + align:start position:0% +right here uh that represents the space +charge region now we have uh so this is + + align:start position:0% +charge region now we have uh so this is + + + align:start position:0% +charge region now we have uh so this is +in the dark uh now we have the energy + + align:start position:0% +in the dark uh now we have the energy + + + align:start position:0% +in the dark uh now we have the energy +band diagram shown right here where this + + align:start position:0% +band diagram shown right here where this + + + align:start position:0% +band diagram shown right here where this +dashed Blue Line represents the chemical + + align:start position:0% +dashed Blue Line represents the chemical + + + align:start position:0% +dashed Blue Line represents the chemical +potential also called the firmy energy + + align:start position:0% +potential also called the firmy energy + + + align:start position:0% +potential also called the firmy energy +uh throughout the entire uh uh device + + align:start position:0% +uh throughout the entire uh uh device + + + align:start position:0% +uh throughout the entire uh uh device +right here in cross-section and just to + + align:start position:0% +right here in cross-section and just to + + + align:start position:0% +right here in cross-section and just to +be very very clear we've so far + + align:start position:0% +be very very clear we've so far + + + align:start position:0% +be very very clear we've so far +described the solar cell as light coming + + align:start position:0% +described the solar cell as light coming + + + align:start position:0% +described the solar cell as light coming +through the top and now we've rotated + + align:start position:0% +through the top and now we've rotated + + + align:start position:0% +through the top and now we've rotated +this structure by 90° to represent the p + + align:start position:0% +this structure by 90° to represent the p + + + align:start position:0% +this structure by 90° to represent the p +and Jun and that's been a little + + align:start position:0% +and Jun and that's been a little + + + align:start position:0% +and Jun and that's been a little +confusing for some folks so just to be + + align:start position:0% +confusing for some folks so just to be + + + align:start position:0% +confusing for some folks so just to be +totally clear in a device like this one + + align:start position:0% +totally clear in a device like this one + + + align:start position:0% +totally clear in a device like this one +if it were subject to illumination um + + align:start position:0% +if it were subject to illumination um + + + align:start position:0% +if it were subject to illumination um +you would have light coming in from the + + align:start position:0% +you would have light coming in from the + + + align:start position:0% +you would have light coming in from the +side right either from the P side or + + align:start position:0% +side right either from the P side or + + + align:start position:0% +side right either from the P side or +from the N side so to transfer this into + + align:start position:0% +from the N side so to transfer this into + + + align:start position:0% +from the N side so to transfer this into +what we've seen so far where the solar + + align:start position:0% +what we've seen so far where the solar + + + align:start position:0% +what we've seen so far where the solar +cell devic is facing up toward the sun + + align:start position:0% +cell devic is facing up toward the sun + + + align:start position:0% +cell devic is facing up toward the sun +you'd have to rotate this by 90° right + + align:start position:0% +you'd have to rotate this by 90° right + + + align:start position:0% +you'd have to rotate this by 90° right +just to make sure we're all clear with + + align:start position:0% +just to make sure we're all clear with + + + align:start position:0% +just to make sure we're all clear with +orientations good so we have the fir + + align:start position:0% +orientations good so we have the fir + + + align:start position:0% +orientations good so we have the fir +energy right here uh the drift and + + align:start position:0% +energy right here uh the drift and + + + align:start position:0% +energy right here uh the drift and +diffusion currents for electrons + + align:start position:0% +diffusion currents for electrons + + + align:start position:0% +diffusion currents for electrons +electron diffusion electron drift there + + align:start position:0% +electron diffusion electron drift there + + + align:start position:0% +electron diffusion electron drift there +is a an abundance of electrons over here + + align:start position:0% +is a an abundance of electrons over here + + + align:start position:0% +is a an abundance of electrons over here +in the N type side and so they want to + + align:start position:0% +in the N type side and so they want to + + + align:start position:0% +in the N type side and so they want to +diffuse over to the ptype that's why the + + align:start position:0% +diffuse over to the ptype that's why the + + + align:start position:0% +diffuse over to the ptype that's why the +diffusion current is pointing left once + + align:start position:0% +diffusion current is pointing left once + + + align:start position:0% +diffusion current is pointing left once +they do to a certain degree they set up + + align:start position:0% +they do to a certain degree they set up + + + align:start position:0% +they do to a certain degree they set up +a field the electrons and holes the + + align:start position:0% +a field the electrons and holes the + + + align:start position:0% +a field the electrons and holes the +mobile charges set up a field and that + + align:start position:0% +mobile charges set up a field and that + + + align:start position:0% +mobile charges set up a field and that +creates a drift current uh that + + align:start position:0% +creates a drift current uh that + + + align:start position:0% +creates a drift current uh that +counteracts the fusion and once these + + align:start position:0% +counteracts the fusion and once these + + + align:start position:0% +counteracts the fusion and once these +two are in equilibrium there's no + + align:start position:0% +two are in equilibrium there's no + + + align:start position:0% +two are in equilibrium there's no +current flowing through our device + + align:start position:0% +current flowing through our device + + + align:start position:0% +current flowing through our device +that's why current is equal to zero + + align:start position:0% +that's why current is equal to zero + + + align:start position:0% +that's why current is equal to zero +right here and there's also no potential + + align:start position:0% +right here and there's also no potential + + + align:start position:0% +right here and there's also no potential +difference because the firmy energy the + + align:start position:0% +difference because the firmy energy the + + + align:start position:0% +difference because the firmy energy the +chemical potential is the same on either + + align:start position:0% +chemical potential is the same on either + + + align:start position:0% +chemical potential is the same on either +side of that device and so the voltage + + align:start position:0% +side of that device and so the voltage + + + align:start position:0% +side of that device and so the voltage +output of that solar cell would also be + + align:start position:0% +output of that solar cell would also be + + + align:start position:0% +output of that solar cell would also be +zero we when we forward bias our device + + align:start position:0% +zero we when we forward bias our device + + + align:start position:0% +zero we when we forward bias our device +um now we're forcing a separation of or + + align:start position:0% +um now we're forcing a separation of or + + + align:start position:0% +um now we're forcing a separation of or +or we're forcing a separation of the + + align:start position:0% +or we're forcing a separation of the + + + align:start position:0% +or we're forcing a separation of the +chemical potential on either side of the + + align:start position:0% +chemical potential on either side of the + + + align:start position:0% +chemical potential on either side of the +device um if you connected this to an + + align:start position:0% +device um if you connected this to an + + + align:start position:0% +device um if you connected this to an +external circuit um the electrons would + + align:start position:0% +external circuit um the electrons would + + + align:start position:0% +external circuit um the electrons would +want to flow from this side to that side + + align:start position:0% +want to flow from this side to that side + + + align:start position:0% +want to flow from this side to that side +um but uh since we're forcing uh this + + align:start position:0% +um but uh since we're forcing uh this + + + align:start position:0% +um but uh since we're forcing uh this +condition here with the battery uh we + + align:start position:0% +condition here with the battery uh we + + + align:start position:0% +condition here with the battery uh we +are reducing the barrier height here uh + + align:start position:0% +are reducing the barrier height here uh + + + align:start position:0% +are reducing the barrier height here uh +electrons can now diffuse over from the + + align:start position:0% +electrons can now diffuse over from the + + + align:start position:0% +electrons can now diffuse over from the +N type into the ptype side uh and they + + align:start position:0% +N type into the ptype side uh and they + + + align:start position:0% +N type into the ptype side uh and they +do and the diffusion current increases + + align:start position:0% +do and the diffusion current increases + + + align:start position:0% +do and the diffusion current increases +and that's why we have a current now a + + align:start position:0% +and that's why we have a current now a + + + align:start position:0% +and that's why we have a current now a +positive value we've defined uh the + + align:start position:0% +positive value we've defined uh the + + + align:start position:0% +positive value we've defined uh the +electrons traveling to the left as being + + align:start position:0% +electrons traveling to the left as being + + + align:start position:0% +electrons traveling to the left as being +a positive current we have uh now + + align:start position:0% +a positive current we have uh now + + + align:start position:0% +a positive current we have uh now +electrons traveling from the N type uh + + align:start position:0% +electrons traveling from the N type uh + + + align:start position:0% +electrons traveling from the N type uh +to the ptype material when we reverse + + align:start position:0% +to the ptype material when we reverse + + + align:start position:0% +to the ptype material when we reverse +bias our device notice the separation of + + align:start position:0% +bias our device notice the separation of + + + align:start position:0% +bias our device notice the separation of +the firm energies again we have uh here + + align:start position:0% +the firm energies again we have uh here + + + align:start position:0% +the firm energies again we have uh here +uh one sign of voltage because the right + + align:start position:0% +uh one sign of voltage because the right + + + align:start position:0% +uh one sign of voltage because the right +side is higher than the left and now the + + align:start position:0% +side is higher than the left and now the + + + align:start position:0% +side is higher than the left and now the +right side is lower than the left so our + + align:start position:0% +right side is lower than the left so our + + + align:start position:0% +right side is lower than the left so our +voltage sign flips from right to left + + align:start position:0% +voltage sign flips from right to left + + + align:start position:0% +voltage sign flips from right to left +over here from positive to negative + + align:start position:0% +over here from positive to negative + + + align:start position:0% +over here from positive to negative +values so notice the voltage and now the + + align:start position:0% +values so notice the voltage and now the + + + align:start position:0% +values so notice the voltage and now the +current as well the drift current will + + align:start position:0% +current as well the drift current will + + + align:start position:0% +current as well the drift current will +uh outweigh the diffusion current in + + align:start position:0% +uh outweigh the diffusion current in + + + align:start position:0% +uh outweigh the diffusion current in +this particular case uh because now the + + align:start position:0% +this particular case uh because now the + + + align:start position:0% +this particular case uh because now the +uh barrier for electrons to diffuse from + + align:start position:0% +uh barrier for electrons to diffuse from + + + align:start position:0% +uh barrier for electrons to diffuse from +the end to the P type is very large + + align:start position:0% +the end to the P type is very large + + + align:start position:0% +the end to the P type is very large +they'll have difficulty going from that + + align:start position:0% +they'll have difficulty going from that + + + align:start position:0% +they'll have difficulty going from that +side to that side whereas the drift + + align:start position:0% +side to that side whereas the drift + + + align:start position:0% +side to that side whereas the drift +current is is uh larger because of the + + align:start position:0% +current is is uh larger because of the + + + align:start position:0% +current is is uh larger because of the +larger electric field and as a result + + align:start position:0% +larger electric field and as a result + + + align:start position:0% +larger electric field and as a result +the drift current will dominate and so + + align:start position:0% +the drift current will dominate and so + + + align:start position:0% +the drift current will dominate and so +now instead of electrons flowing from n + + align:start position:0% +now instead of electrons flowing from n + + + align:start position:0% +now instead of electrons flowing from n +type to ptype where we had defined as + + align:start position:0% +type to ptype where we had defined as + + + align:start position:0% +type to ptype where we had defined as +positive current electrons are flowing + + align:start position:0% +positive current electrons are flowing + + + align:start position:0% +positive current electrons are flowing +from ptype to n type in net which we + + align:start position:0% +from ptype to n type in net which we + + + align:start position:0% +from ptype to n type in net which we +Define as negative current and that's + + align:start position:0% +Define as negative current and that's + + + align:start position:0% +Define as negative current and that's +why our current has changed signs over + + align:start position:0% +why our current has changed signs over + + + align:start position:0% +why our current has changed signs over +here notice that we're in positive + + align:start position:0% +here notice that we're in positive + + + align:start position:0% +here notice that we're in positive +current territory and over here notice + + align:start position:0% +current territory and over here notice + + + align:start position:0% +current territory and over here notice +we're in negative current + + align:start position:0% +we're in negative current + + + align:start position:0% +we're in negative current +territory also you'll notice the width + + align:start position:0% +territory also you'll notice the width + + + align:start position:0% +territory also you'll notice the width +of the space charge region changing as + + align:start position:0% +of the space charge region changing as + + + align:start position:0% +of the space charge region changing as +we forward and reverse bias our device + + align:start position:0% +we forward and reverse bias our device + + + align:start position:0% +we forward and reverse bias our device +as the barrier height decreases we have + + align:start position:0% +as the barrier height decreases we have + + + align:start position:0% +as the barrier height decreases we have +a decrease of the built-in electric + + align:start position:0% +a decrease of the built-in electric + + + align:start position:0% +a decrease of the built-in electric +field we have a decrease of the amount + + align:start position:0% +field we have a decrease of the amount + + + align:start position:0% +field we have a decrease of the amount +of charge on either side of the junction + + align:start position:0% +of charge on either side of the junction + + + align:start position:0% +of charge on either side of the junction +uh that's why the depletion with + + align:start position:0% +uh that's why the depletion with + + + align:start position:0% +uh that's why the depletion with +decreases and the opposite happens here + + align:start position:0% +decreases and the opposite happens here + + + align:start position:0% +decreases and the opposite happens here +under reverse bias so uh getting to the + + align:start position:0% +under reverse bias so uh getting to the + + + align:start position:0% +under reverse bias so uh getting to the +point where you can set up a p + + align:start position:0% +point where you can set up a p + + + align:start position:0% +point where you can set up a p +injunction and understand how drift and + + align:start position:0% +injunction and understand how drift and + + + align:start position:0% +injunction and understand how drift and +and diffusion currents come into being + + align:start position:0% +and diffusion currents come into being + + + align:start position:0% +and diffusion currents come into being +in the first place and then being able + + align:start position:0% +in the first place and then being able + + + align:start position:0% +in the first place and then being able +to bias your solar or your bias your + + align:start position:0% +to bias your solar or your bias your + + + align:start position:0% +to bias your solar or your bias your +diode under different conditions is a + + align:start position:0% +diode under different conditions is a + + + align:start position:0% +diode under different conditions is a +really important fundamental skill uh + + align:start position:0% +really important fundamental skill uh + + + align:start position:0% +really important fundamental skill uh +for uh understanding solar cell works + + align:start position:0% +for uh understanding solar cell works + + + align:start position:0% +for uh understanding solar cell works +question on the forward and reverse bias + + align:start position:0% +question on the forward and reverse bias + + + align:start position:0% +question on the forward and reverse bias +is the firing energy actually continuous + + align:start position:0% +is the firing energy actually continuous + + + align:start position:0% +is the firing energy actually continuous +or does it actually make a jum uh so the + + align:start position:0% +or does it actually make a jum uh so the + + + align:start position:0% +or does it actually make a jum uh so the +uh firy energy um which we Define here + + align:start position:0% +uh firy energy um which we Define here + + + align:start position:0% +uh firy energy um which we Define here +as as as the chemical potential notice + + align:start position:0% +as as as the chemical potential notice + + + align:start position:0% +as as as the chemical potential notice +we're avoiding talking about what's + + align:start position:0% +we're avoiding talking about what's + + + align:start position:0% +we're avoiding talking about what's +happening here in the middle until a + + align:start position:0% +happening here in the middle until a + + + align:start position:0% +happening here in the middle until a +couple of lectures from now um that gets + + align:start position:0% +couple of lectures from now um that gets + + + align:start position:0% +couple of lectures from now um that gets +into a a gray Zone where we talk about + + align:start position:0% +into a a gray Zone where we talk about + + + align:start position:0% +into a a gray Zone where we talk about +quasi energies we'll get to that in a + + align:start position:0% +quasi energies we'll get to that in a + + + align:start position:0% +quasi energies we'll get to that in a +minute maybe a couple of lectures but + + align:start position:0% +minute maybe a couple of lectures but + + + align:start position:0% +minute maybe a couple of lectures but +yes the firy energy in the extreme uh + + align:start position:0% +yes the firy energy in the extreme uh + + + align:start position:0% +yes the firy energy in the extreme uh +sides right here near the contacts so + + align:start position:0% +sides right here near the contacts so + + + align:start position:0% +sides right here near the contacts so +you're contacting your device over here + + align:start position:0% +you're contacting your device over here + + + align:start position:0% +you're contacting your device over here +you're contacting your device over here + + align:start position:0% +you're contacting your device over here + + + align:start position:0% +you're contacting your device over here +those those fir energies are different + + align:start position:0% +those those fir energies are different + + + align:start position:0% +those those fir energies are different +on an an absolute energy scale so there + + align:start position:0% +on an an absolute energy scale so there + + + align:start position:0% +on an an absolute energy scale so there +is uh an energy difference when you're + + align:start position:0% +is uh an energy difference when you're + + + align:start position:0% +is uh an energy difference when you're +driving the electrons from one side to + + align:start position:0% +driving the electrons from one side to + + + align:start position:0% +driving the electrons from one side to +the + + align:start position:0% + + + + align:start position:0% + +other notice in this case right here you + + align:start position:0% +other notice in this case right here you + + + align:start position:0% +other notice in this case right here you +would think that the electrons would + + align:start position:0% +would think that the electrons would + + + align:start position:0% +would think that the electrons would +want to travel through an external + + align:start position:0% +want to travel through an external + + + align:start position:0% +want to travel through an external +circuit to come back to this side + + align:start position:0% +circuit to come back to this side + + + align:start position:0% +circuit to come back to this side +because their energy is higher in this + + align:start position:0% +because their energy is higher in this + + + align:start position:0% +because their energy is higher in this +side and lower over here but we're not + + align:start position:0% +side and lower over here but we're not + + + align:start position:0% +side and lower over here but we're not +uh we're not Illuminating the solar cell + + align:start position:0% +uh we're not Illuminating the solar cell + + + align:start position:0% +uh we're not Illuminating the solar cell +yet we're biasing it using a battery uh + + align:start position:0% +yet we're biasing it using a battery uh + + + align:start position:0% +yet we're biasing it using a battery uh +and this is why uh we have current flow + + align:start position:0% +and this is why uh we have current flow + + + align:start position:0% +and this is why uh we have current flow +coming from this side into that side + + align:start position:0% +coming from this side into that side + + + align:start position:0% +coming from this side into that side +we're essentially forcing the electrons + + align:start position:0% +we're essentially forcing the electrons + + + align:start position:0% +we're essentially forcing the electrons +from the N type into the ptype material + + align:start position:0% +from the N type into the ptype material + + + align:start position:0% +from the N type into the ptype material +we're pushing them up that hill with a + + align:start position:0% +we're pushing them up that hill with a + + + align:start position:0% +we're pushing them up that hill with a +battery and that's why we have this + + align:start position:0% +battery and that's why we have this + + + align:start position:0% +battery and that's why we have this +diffusion current um uh dominating in + + align:start position:0% +diffusion current um uh dominating in + + + align:start position:0% +diffusion current um uh dominating in +the dark in the dark so we have a + + align:start position:0% +the dark in the dark so we have a + + + align:start position:0% +the dark in the dark so we have a +current flowing from right to left in + + align:start position:0% +current flowing from right to left in + + + align:start position:0% +current flowing from right to left in +the illuminated case um we'll have all + + align:start position:0% +the illuminated case um we'll have all + + + align:start position:0% +the illuminated case um we'll have all +of our carriers traveling from left to + + align:start position:0% +of our carriers traveling from left to + + + align:start position:0% +of our carriers traveling from left to +right um and in the dark this is the + + align:start position:0% +right um and in the dark this is the + + + align:start position:0% +right um and in the dark this is the +only case in which we have carriers + + align:start position:0% +only case in which we have carriers + + + align:start position:0% +only case in which we have carriers +traveling from uh right to left and it's + + align:start position:0% +traveling from uh right to left and it's + + + align:start position:0% +traveling from uh right to left and it's +happening because we're using that + + align:start position:0% +happening because we're using that + + + align:start position:0% +happening because we're using that +battery in the dark + + align:start position:0% +battery in the dark + + + align:start position:0% +battery in the dark +uh to change the uh chemical potential + + align:start position:0% +uh to change the uh chemical potential + + + align:start position:0% +uh to change the uh chemical potential +on other side which in effect reduces + + align:start position:0% +on other side which in effect reduces + + + align:start position:0% +on other side which in effect reduces +this barrier height and allows carriers + + align:start position:0% +this barrier height and allows carriers + + + align:start position:0% +this barrier height and allows carriers +to diffuse from the N type and the ptype + + align:start position:0% +to diffuse from the N type and the ptype + + + align:start position:0% +to diffuse from the N type and the ptype +so you can think about it as uh forcing + + align:start position:0% +so you can think about it as uh forcing + + + align:start position:0% +so you can think about it as uh forcing +carriers up the junction right and this + + align:start position:0% +carriers up the junction right and this + + + align:start position:0% +carriers up the junction right and this +is a very useful technique because in + + align:start position:0% +is a very useful technique because in + + + align:start position:0% +is a very useful technique because in +effect what it's doing in a real device + + align:start position:0% +effect what it's doing in a real device + + + align:start position:0% +effect what it's doing in a real device +when you have a two-dimensional device + + align:start position:0% +when you have a two-dimensional device + + + align:start position:0% +when you have a two-dimensional device +with in homogeneities uh the current + + align:start position:0% +with in homogeneities uh the current + + + align:start position:0% +with in homogeneities uh the current +will travel through the weakest point of + + align:start position:0% +will travel through the weakest point of + + + align:start position:0% +will travel through the weakest point of +that P Junction wherever the barrier + + align:start position:0% +that P Junction wherever the barrier + + + align:start position:0% +that P Junction wherever the barrier +height is lowest current will begin + + align:start position:0% +height is lowest current will begin + + + align:start position:0% +height is lowest current will begin +crowding through that spot and so it's a + + align:start position:0% +crowding through that spot and so it's a + + + align:start position:0% +crowding through that spot and so it's a +way of probing or testing uh the the + + align:start position:0% +way of probing or testing uh the the + + + align:start position:0% +way of probing or testing uh the the +quality of your Junction characteristic + + align:start position:0% +quality of your Junction characteristic + + + align:start position:0% +quality of your Junction characteristic +in the + + align:start position:0% +in the + + + align:start position:0% +in the +dark okay so this is uh these this is a + + align:start position:0% +dark okay so this is uh these this is a + + + align:start position:0% +dark okay so this is uh these this is a +basic of of the basics of of p and + + align:start position:0% +basic of of the basics of of p and + + + align:start position:0% +basic of of the basics of of p and +Junction in the dark let's flip our page + + align:start position:0% +Junction in the dark let's flip our page + + + align:start position:0% +Junction in the dark let's flip our page +over and now let's try to imagine what + + align:start position:0% +over and now let's try to imagine what + + + align:start position:0% +over and now let's try to imagine what +will happen under illuminated conditions + + align:start position:0% +will happen under illuminated conditions + + + align:start position:0% +will happen under illuminated conditions +and let's start out in a very simple + + align:start position:0% +and let's start out in a very simple + + + align:start position:0% +and let's start out in a very simple +case we'll assume that the principle of + + align:start position:0% +case we'll assume that the principle of + + + align:start position:0% +case we'll assume that the principle of +superposition applies here that the + + align:start position:0% +superposition applies here that the + + + align:start position:0% +superposition applies here that the +photo excited carriers in other words + + align:start position:0% +photo excited carriers in other words + + + align:start position:0% +photo excited carriers in other words +when light shines into our device I'm + + align:start position:0% +when light shines into our device I'm + + + align:start position:0% +when light shines into our device I'm +looking at this one right now this one + + align:start position:0% +looking at this one right now this one + + + align:start position:0% +looking at this one right now this one +right here and lights coming in and + + align:start position:0% +right here and lights coming in and + + + align:start position:0% +right here and lights coming in and +generating electron whole pairs + + align:start position:0% +generating electron whole pairs + + + align:start position:0% +generating electron whole pairs +essentially exciting electrons across + + align:start position:0% +essentially exciting electrons across + + + align:start position:0% +essentially exciting electrons across +the band Gap like we described in + + align:start position:0% +the band Gap like we described in + + + align:start position:0% +the band Gap like we described in +lecture three so we have uh carriers now + + align:start position:0% +lecture three so we have uh carriers now + + + align:start position:0% +lecture three so we have uh carriers now +being excited across the band Gap what + + align:start position:0% +being excited across the band Gap what + + + align:start position:0% +being excited across the band Gap what +will happen to those electrons now that + + align:start position:0% +will happen to those electrons now that + + + align:start position:0% +will happen to those electrons now that +they're in the conduction band where + + align:start position:0% +they're in the conduction band where + + + align:start position:0% +they're in the conduction band where +will they want to + + align:start position:0% +will they want to + + + align:start position:0% +will they want to +go to the right right okay so what + + align:start position:0% +go to the right right okay so what + + + align:start position:0% +go to the right right okay so what +you'll do is set up what's called an + + align:start position:0% +you'll do is set up what's called an + + + align:start position:0% +you'll do is set up what's called an +illumination current notice now at the + + align:start position:0% +illumination current notice now at the + + + align:start position:0% +illumination current notice now at the +bottom of of the second uh row here you + + align:start position:0% +bottom of of the second uh row here you + + + align:start position:0% +bottom of of the second uh row here you +have electron diffusion electron drift + + align:start position:0% +have electron diffusion electron drift + + + align:start position:0% +have electron diffusion electron drift +and Ill current ill stand for + + align:start position:0% +and Ill current ill stand for + + + align:start position:0% +and Ill current ill stand for +illumination current so you have a third + + align:start position:0% +illumination current so you have a third + + + align:start position:0% +illumination current so you have a third +Arrow here that will have to be + + align:start position:0% +Arrow here that will have to be + + + align:start position:0% +Arrow here that will have to be +implemented in some way and that will uh + + align:start position:0% +implemented in some way and that will uh + + + align:start position:0% +implemented in some way and that will uh +by the principle of superposition you + + align:start position:0% +by the principle of superposition you + + + align:start position:0% +by the principle of superposition you +should think what happens to your IV + + align:start position:0% +should think what happens to your IV + + + align:start position:0% +should think what happens to your IV +curve as well so let's make an estimate + + align:start position:0% +curve as well so let's make an estimate + + + align:start position:0% +curve as well so let's make an estimate +of what we think should happen then I'll + + align:start position:0% +of what we think should happen then I'll + + + align:start position:0% +of what we think should happen then I'll +confer some notes and then we'll measure + + align:start position:0% +confer some notes and then we'll measure + + + align:start position:0% +confer some notes and then we'll measure +what actually does happen under + + align:start position:0% +what actually does happen under + + + align:start position:0% +what actually does happen under +illumination so I'm going give it a + + align:start position:0% + + + + align:start position:0% + +shot what does forward and reverse bias + + align:start position:0% +shot what does forward and reverse bias + + + align:start position:0% +shot what does forward and reverse bias +mean when there's no battery this is a + + align:start position:0% +mean when there's no battery this is a + + + align:start position:0% +mean when there's no battery this is a +very interesting question so once you + + align:start position:0% +very interesting question so once you + + + align:start position:0% +very interesting question so once you +start illuminating your solar cell + + align:start position:0% +start illuminating your solar cell + + + align:start position:0% +start illuminating your solar cell +device and you start injecting carriers + + align:start position:0% +device and you start injecting carriers + + + align:start position:0% +device and you start injecting carriers +into it um the uh what will happen is + + align:start position:0% +into it um the uh what will happen is + + + align:start position:0% +into it um the uh what will happen is +very naturally this uh this band + + align:start position:0% +very naturally this uh this band + + + align:start position:0% +very naturally this uh this band +alignment that you see right here this + + align:start position:0% +alignment that you see right here this + + + align:start position:0% +alignment that you see right here this +band diagram will begin to shift toward + + align:start position:0% +band diagram will begin to shift toward + + + align:start position:0% +band diagram will begin to shift toward +the forward bias condition rationale + + align:start position:0% +the forward bias condition rationale + + + align:start position:0% +the forward bias condition rationale +you'll be generating carriers they'll be + + align:start position:0% +you'll be generating carriers they'll be + + + align:start position:0% +you'll be generating carriers they'll be +swept over into this region here one way + + align:start position:0% +swept over into this region here one way + + + align:start position:0% +swept over into this region here one way +to think about it is that you'll be + + align:start position:0% +to think about it is that you'll be + + + align:start position:0% +to think about it is that you'll be +increasing the number of electrons over + + align:start position:0% +increasing the number of electrons over + + + align:start position:0% +increasing the number of electrons over +here and the number of holes over here + + align:start position:0% +here and the number of holes over here + + + align:start position:0% +here and the number of holes over here +which will naturally cause the uh the + + align:start position:0% +which will naturally cause the uh the + + + align:start position:0% +which will naturally cause the uh the +energy of those electrons to increase on + + align:start position:0% +energy of those electrons to increase on + + + align:start position:0% +energy of those electrons to increase on +the side the chemical potential on the + + align:start position:0% +the side the chemical potential on the + + + align:start position:0% +the side the chemical potential on the +sides increase so one way to think about + + align:start position:0% +sides increase so one way to think about + + + align:start position:0% +sides increase so one way to think about +it is as you're illuminating your solar + + align:start position:0% +it is as you're illuminating your solar + + + align:start position:0% +it is as you're illuminating your solar +cell more and more and more you're + + align:start position:0% +cell more and more and more you're + + + align:start position:0% +cell more and more and more you're +forcing a forward bias condition on your + + align:start position:0% +forcing a forward bias condition on your + + + align:start position:0% +forcing a forward bias condition on your +device to get the solar cell to go into + + align:start position:0% +device to get the solar cell to go into + + + align:start position:0% +device to get the solar cell to go into +reverse bias you really do need to bias + + align:start position:0% +reverse bias you really do need to bias + + + align:start position:0% +reverse bias you really do need to bias +your device you physically need to to + + align:start position:0% +your device you physically need to to + + + align:start position:0% +your device you physically need to to +bias + + align:start position:0% + + + + align:start position:0% + +it yes so um when I when I mentioned + + align:start position:0% +it yes so um when I when I mentioned + + + align:start position:0% +it yes so um when I when I mentioned +illumination current here we're really + + align:start position:0% +illumination current here we're really + + + align:start position:0% +illumination current here we're really +talking about the electron illumination + + align:start position:0% +talking about the electron illumination + + + align:start position:0% +talking about the electron illumination +current right where what what direction + + align:start position:0% +current right where what what direction + + + align:start position:0% +current right where what what direction +of travel the electrons are taking + + align:start position:0% +of travel the electrons are taking + + + align:start position:0% +of travel the electrons are taking +inside of our system so uh yes the + + align:start position:0% +inside of our system so uh yes the + + + align:start position:0% +inside of our system so uh yes the +electrons would be traveling from uh + + align:start position:0% +electrons would be traveling from uh + + + align:start position:0% +electrons would be traveling from uh +left to right very astute observation Uh + + align:start position:0% +left to right very astute observation Uh + + + align:start position:0% +left to right very astute observation Uh +current is generally described as a flow + + align:start position:0% +current is generally described as a flow + + + align:start position:0% +current is generally described as a flow +of positive charge and in the absence of + + align:start position:0% +of positive charge and in the absence of + + + align:start position:0% +of positive charge and in the absence of +a definer or um say electrons or holes + + align:start position:0% +a definer or um say electrons or holes + + + align:start position:0% +a definer or um say electrons or holes +uh you rightly could assume that it + + align:start position:0% +uh you rightly could assume that it + + + align:start position:0% +uh you rightly could assume that it +would be the flow of positive charges + + align:start position:0% +would be the flow of positive charges + + + align:start position:0% +would be the flow of positive charges +we're assuming electrons are flowing + + align:start position:0% +we're assuming electrons are flowing + + + align:start position:0% +we're assuming electrons are flowing +here and the alumination + + align:start position:0% + + + + align:start position:0% + +current good all right so so this is + + align:start position:0% +current good all right so so this is + + + align:start position:0% +current good all right so so this is +very positive I see everybody has uh + + align:start position:0% +very positive I see everybody has uh + + + align:start position:0% +very positive I see everybody has uh +settled on the the notion that + + align:start position:0% +settled on the the notion that + + + align:start position:0% +settled on the the notion that +illumination will shift our IV curve + + align:start position:0% +illumination will shift our IV curve + + + align:start position:0% +illumination will shift our IV curve +down because of the way we've defined + + align:start position:0% +down because of the way we've defined + + + align:start position:0% +down because of the way we've defined +current that if current flows from left + + align:start position:0% +current that if current flows from left + + + align:start position:0% +current that if current flows from left +to right that lands Us in negative + + align:start position:0% +to right that lands Us in negative + + + align:start position:0% +to right that lands Us in negative +current territory so that that makes + + align:start position:0% +current territory so that that makes + + + align:start position:0% +current territory so that that makes +sense if we shine light on our system + + align:start position:0% +sense if we shine light on our system + + + align:start position:0% +sense if we shine light on our system +and we have electrons flowing from left + + align:start position:0% +and we have electrons flowing from left + + + align:start position:0% +and we have electrons flowing from left +to right here uh that'll put us into + + align:start position:0% +to right here uh that'll put us into + + + align:start position:0% +to right here uh that'll put us into +negative territory so that shifts the + + align:start position:0% +negative territory so that shifts the + + + align:start position:0% +negative territory so that shifts the +entire thing down and we would add an + + align:start position:0% +entire thing down and we would add an + + + align:start position:0% +entire thing down and we would add an +illumination current an arrow pointing + + align:start position:0% +illumination current an arrow pointing + + + align:start position:0% +illumination current an arrow pointing +to the right right here which would mean + + align:start position:0% +to the right right here which would mean + + + align:start position:0% +to the right right here which would mean +that we would have current flowing + + align:start position:0% +that we would have current flowing + + + align:start position:0% +that we would have current flowing +through our device but there's still no + + align:start position:0% +through our device but there's still no + + + align:start position:0% +through our device but there's still no +difference in the chemical potential on + + align:start position:0% +difference in the chemical potential on + + + align:start position:0% +difference in the chemical potential on +either side there's still no difference + + align:start position:0% +either side there's still no difference + + + align:start position:0% +either side there's still no difference +in firmy energy in the P type and the N + + align:start position:0% +in firmy energy in the P type and the N + + + align:start position:0% +in firmy energy in the P type and the N +type which means our voltage is equal to + + align:start position:0% +type which means our voltage is equal to + + + align:start position:0% +type which means our voltage is equal to +zero which means we're intersecting uh + + align:start position:0% +zero which means we're intersecting uh + + + align:start position:0% +zero which means we're intersecting uh +the the y- axis right here and our + + align:start position:0% +the the y- axis right here and our + + + align:start position:0% +the the y- axis right here and our +little X should be marked uh right down + + align:start position:0% +little X should be marked uh right down + + + align:start position:0% +little X should be marked uh right down +here so it's really just a super + + align:start position:0% +here so it's really just a super + + + align:start position:0% +here so it's really just a super +position great okay now what happens if + + align:start position:0% +position great okay now what happens if + + + align:start position:0% +position great okay now what happens if +we forward bias our device um either uh + + align:start position:0% +we forward bias our device um either uh + + + align:start position:0% +we forward bias our device um either uh +U either because we're we're adding a + + align:start position:0% +U either because we're we're adding a + + + align:start position:0% +U either because we're we're adding a +resistor in series uh to our our solar + + align:start position:0% +resistor in series uh to our our solar + + + align:start position:0% +resistor in series uh to our our solar +cell uh so instead of a battery there + + align:start position:0% +cell uh so instead of a battery there + + + align:start position:0% +cell uh so instead of a battery there +you would replace that with a resistor + + align:start position:0% +you would replace that with a resistor + + + align:start position:0% +you would replace that with a resistor +um or if we're applying a bias voltage + + align:start position:0% +um or if we're applying a bias voltage + + + align:start position:0% +um or if we're applying a bias voltage +as well we could also do that under + + align:start position:0% +as well we could also do that under + + + align:start position:0% +as well we could also do that under +illumination so we'd still have the + + align:start position:0% +illumination so we'd still have the + + + align:start position:0% +illumination so we'd still have the +illumination current right and we'd + + align:start position:0% +illumination current right and we'd + + + align:start position:0% +illumination current right and we'd +through superposition shift this entire + + align:start position:0% +through superposition shift this entire + + + align:start position:0% +through superposition shift this entire +curve down we'd be operating somewhere + + align:start position:0% +curve down we'd be operating somewhere + + + align:start position:0% +curve down we'd be operating somewhere +in this um quadrant right there right so + + align:start position:0% +in this um quadrant right there right so + + + align:start position:0% +in this um quadrant right there right so +this we call a fourth quadrant typically + + align:start position:0% +this we call a fourth quadrant typically + + + align:start position:0% +this we call a fourth quadrant typically +1 2 3 4 fourth qu quadrant this is where + + align:start position:0% +1 2 3 4 fourth qu quadrant this is where + + + align:start position:0% +1 2 3 4 fourth qu quadrant this is where +Power is coming out of the solar cell + + align:start position:0% +Power is coming out of the solar cell + + + align:start position:0% +Power is coming out of the solar cell +device because if we imagine instead of + + align:start position:0% +device because if we imagine instead of + + + align:start position:0% +device because if we imagine instead of +having a battery there we have a + + align:start position:0% +having a battery there we have a + + + align:start position:0% +having a battery there we have a +resistor you will the electrons will + + align:start position:0% +resistor you will the electrons will + + + align:start position:0% +resistor you will the electrons will +travel from the N type material through + + align:start position:0% +travel from the N type material through + + + align:start position:0% +travel from the N type material through +that external load to get to the ptype + + align:start position:0% +that external load to get to the ptype + + + align:start position:0% +that external load to get to the ptype +material where their chemical potential + + align:start position:0% +material where their chemical potential + + + align:start position:0% +material where their chemical potential +is lower right because they'll they'll + + align:start position:0% +is lower right because they'll they'll + + + align:start position:0% +is lower right because they'll they'll +desire to minimize their free energy and + + align:start position:0% +desire to minimize their free energy and + + + align:start position:0% +desire to minimize their free energy and +as a result they'll deposit that power + + align:start position:0% +as a result they'll deposit that power + + + align:start position:0% +as a result they'll deposit that power +across that resistor across that + + align:start position:0% +across that resistor across that + + + align:start position:0% +across that resistor across that +external load in order to get back to + + align:start position:0% +external load in order to get back to + + + align:start position:0% +external load in order to get back to +this other side because that's the only + + align:start position:0% +this other side because that's the only + + + align:start position:0% +this other side because that's the only +path uh that they can travel easily + + align:start position:0% +path uh that they can travel easily + + + align:start position:0% +path uh that they can travel easily +right and so this entire curve shifts + + align:start position:0% +right and so this entire curve shifts + + + align:start position:0% +right and so this entire curve shifts +down you have your red X somewhere in + + align:start position:0% +down you have your red X somewhere in + + + align:start position:0% +down you have your red X somewhere in +this quadrant over here and uh Power is + + align:start position:0% +this quadrant over here and uh Power is + + + align:start position:0% +this quadrant over here and uh Power is +Flowing uh out of the solar cell across + + align:start position:0% +Flowing uh out of the solar cell across + + + align:start position:0% +Flowing uh out of the solar cell across +that external load so on the next slide + + align:start position:0% +that external load so on the next slide + + + align:start position:0% +that external load so on the next slide +pretty much everything is right except + + align:start position:0% +pretty much everything is right except + + + align:start position:0% +pretty much everything is right except +that meula I forgot to replace the + + align:start position:0% +that meula I forgot to replace the + + + align:start position:0% +that meula I forgot to replace the +battery up there with a little resistor + + align:start position:0% +battery up there with a little resistor + + + align:start position:0% +battery up there with a little resistor +so you want to correct that in your + + align:start position:0% +so you want to correct that in your + + + align:start position:0% +so you want to correct that in your +notes instead of having the little + + align:start position:0% +notes instead of having the little + + + align:start position:0% +notes instead of having the little +batteries up there uh you can replace + + align:start position:0% +batteries up there uh you can replace + + + align:start position:0% +batteries up there uh you can replace +those with resistors or a resistor in + + align:start position:0% +those with resistors or a resistor in + + + align:start position:0% +those with resistors or a resistor in +series with a battery if you prefer um + + align:start position:0% +series with a battery if you prefer um + + + align:start position:0% +series with a battery if you prefer um +uh since uh depending on on the + + align:start position:0% +uh since uh depending on on the + + + align:start position:0% +uh since uh depending on on the +illumination condition the intensity we + + align:start position:0% +illumination condition the intensity we + + + align:start position:0% +illumination condition the intensity we +may have natural forward bias condition + + align:start position:0% +may have natural forward bias condition + + + align:start position:0% +may have natural forward bias condition +we may need to apply a bias voltage okay + + align:start position:0% +we may need to apply a bias voltage okay + + + align:start position:0% +we may need to apply a bias voltage okay +so we have RV characteristic like this + + align:start position:0% +so we have RV characteristic like this + + + align:start position:0% +so we have RV characteristic like this +we have a red x uh under forward bias + + align:start position:0% +we have a red x uh under forward bias + + + align:start position:0% +we have a red x uh under forward bias +conditions in the fourth quadrant + + align:start position:0% +conditions in the fourth quadrant + + + align:start position:0% +conditions in the fourth quadrant +denoting that power would be flowing out + + align:start position:0% +denoting that power would be flowing out + + + align:start position:0% +denoting that power would be flowing out +of this solar cell device under these + + align:start position:0% +of this solar cell device under these + + + align:start position:0% +of this solar cell device under these +conditions and now uh the bias is + + align:start position:0% +conditions and now uh the bias is + + + align:start position:0% +conditions and now uh the bias is +inverted we have reverse bias conditions + + align:start position:0% +inverted we have reverse bias conditions + + + align:start position:0% +inverted we have reverse bias conditions +and notice that the current is still has + + align:start position:0% +and notice that the current is still has + + + align:start position:0% +and notice that the current is still has +the same sign so the current is negative + + align:start position:0% +the same sign so the current is negative + + + align:start position:0% +the same sign so the current is negative +here negative here and negative here so + + align:start position:0% +here negative here and negative here so + + + align:start position:0% +here negative here and negative here so +the current is the net current is always + + align:start position:0% +the current is the net current is always + + + align:start position:0% +the current is the net current is always +flowing in in the same direction in all + + align:start position:0% +flowing in in the same direction in all + + + align:start position:0% +flowing in in the same direction in all +cases because we have this illumination + + align:start position:0% +cases because we have this illumination + + + align:start position:0% +cases because we have this illumination +current because we have this generation + + align:start position:0% +current because we have this generation + + + align:start position:0% +current because we have this generation +of carriers inside of the material + + align:start position:0% +of carriers inside of the material + + + align:start position:0% +of carriers inside of the material +that's pretty cool that wasn't the case + + align:start position:0% +that's pretty cool that wasn't the case + + + align:start position:0% +that's pretty cool that wasn't the case +when we had the device in the dark here + + align:start position:0% +when we had the device in the dark here + + + align:start position:0% +when we had the device in the dark here +in in forward bias conditions we're + + align:start position:0% +in in forward bias conditions we're + + + align:start position:0% +in in forward bias conditions we're +actually forcing carriers from the N + + align:start position:0% +actually forcing carriers from the N + + + align:start position:0% +actually forcing carriers from the N +type material into the ptype material + + align:start position:0% +type material into the ptype material + + + align:start position:0% +type material into the ptype material +right but under illumination now we have + + align:start position:0% +right but under illumination now we have + + + align:start position:0% +right but under illumination now we have +all of our carriers traveling from uh + + align:start position:0% +all of our carriers traveling from uh + + + align:start position:0% +all of our carriers traveling from uh +the P type into the N type what's + + align:start position:0% +the P type into the N type what's + + + align:start position:0% +the P type into the N type what's +varying is uh the potential uh with that + + align:start position:0% +varying is uh the potential uh with that + + + align:start position:0% +varying is uh the potential uh with that +the carrier have and of course the total + + align:start position:0% +the carrier have and of course the total + + + align:start position:0% +the carrier have and of course the total +amount of current as you forward bias + + align:start position:0% +amount of current as you forward bias + + + align:start position:0% +amount of current as you forward bias +more and more and more this um downhill + + align:start position:0% +more and more and more this um downhill + + + align:start position:0% +more and more and more this um downhill +slope here decreases right so there's + + align:start position:0% +slope here decreases right so there's + + + align:start position:0% +slope here decreases right so there's +less of a driving force for the carriers + + align:start position:0% +less of a driving force for the carriers + + + align:start position:0% +less of a driving force for the carriers +to be going from the P type to the N + + align:start position:0% +to be going from the P type to the N + + + align:start position:0% +to be going from the P type to the N +type and that's why the current approach + + align:start position:0% +type and that's why the current approach + + + align:start position:0% +type and that's why the current approach +is + + align:start position:0% +is + + + align:start position:0% +is +zero eventually at some point if you + + align:start position:0% +zero eventually at some point if you + + + align:start position:0% +zero eventually at some point if you +keep forward biasing here the current + + align:start position:0% +keep forward biasing here the current + + + align:start position:0% +keep forward biasing here the current +will be zero there will be no net + + align:start position:0% +will be zero there will be no net + + + align:start position:0% +will be zero there will be no net +current flow right because there will be + + align:start position:0% +current flow right because there will be + + + align:start position:0% +current flow right because there will be +no driving force for the carriers to go + + align:start position:0% +no driving force for the carriers to go + + + align:start position:0% +no driving force for the carriers to go +from the P type into the N type there + + align:start position:0% +from the P type into the N type there + + + align:start position:0% +from the P type into the N type there +will be no more built-in field + + align:start position:0% + + + + align:start position:0% + +kind of cool okay so now we're beginning + + align:start position:0% +kind of cool okay so now we're beginning + + + align:start position:0% +kind of cool okay so now we're beginning +to wrap our heads around uh what's + + align:start position:0% +to wrap our heads around uh what's + + + align:start position:0% +to wrap our heads around uh what's +happening to the electrons and holes + + align:start position:0% +happening to the electrons and holes + + + align:start position:0% +happening to the electrons and holes +during solar cell operation um let me + + align:start position:0% +during solar cell operation um let me + + + align:start position:0% +during solar cell operation um let me +put a little bit of mathematics to this + + align:start position:0% +put a little bit of mathematics to this + + + align:start position:0% +put a little bit of mathematics to this +uh these are your IV curves the blue is + + align:start position:0% +uh these are your IV curves the blue is + + + align:start position:0% +uh these are your IV curves the blue is +in the dark and the red is under + + align:start position:0% +in the dark and the red is under + + + align:start position:0% +in the dark and the red is under +illumination and uh we're focused on + + align:start position:0% +illumination and uh we're focused on + + + align:start position:0% +illumination and uh we're focused on +this fourth quadrant right here because + + align:start position:0% +this fourth quadrant right here because + + + align:start position:0% +this fourth quadrant right here because +this is a quadrant which power is coming + + align:start position:0% +this is a quadrant which power is coming + + + align:start position:0% +this is a quadrant which power is coming +out of our solar cell device which + + align:start position:0% +out of our solar cell device which + + + align:start position:0% +out of our solar cell device which +usable Power is coming out that we can + + align:start position:0% +usable Power is coming out that we can + + + align:start position:0% +usable Power is coming out that we can +power an external load why + + align:start position:0% +power an external load why + + + align:start position:0% +power an external load why +well first off the voltage is such that + + align:start position:0% +well first off the voltage is such that + + + align:start position:0% +well first off the voltage is such that +we can power an external load we have + + align:start position:0% +we can power an external load we have + + + align:start position:0% +we can power an external load we have +charge separation the electrons are + + align:start position:0% +charge separation the electrons are + + + align:start position:0% +charge separation the electrons are +accumulated over here and they have + + align:start position:0% +accumulated over here and they have + + + align:start position:0% +accumulated over here and they have +higher potential than they do on the + + align:start position:0% +higher potential than they do on the + + + align:start position:0% +higher potential than they do on the +other side which means that there's + + align:start position:0% +other side which means that there's + + + align:start position:0% +other side which means that there's +there's an incentive for them to go + + align:start position:0% +there's an incentive for them to go + + + align:start position:0% +there's an incentive for them to go +through the external circuit deposit + + align:start position:0% +through the external circuit deposit + + + align:start position:0% +through the external circuit deposit +their their power across that external + + align:start position:0% +their their power across that external + + + align:start position:0% +their their power across that external +load to get back to this other side + + align:start position:0% +load to get back to this other side + + + align:start position:0% +load to get back to this other side +where their potential is lower right so + + align:start position:0% +where their potential is lower right so + + + align:start position:0% +where their potential is lower right so +the voltage is favorable and the current + + align:start position:0% +the voltage is favorable and the current + + + align:start position:0% +the voltage is favorable and the current +is also favorable because now we have + + align:start position:0% +is also favorable because now we have + + + align:start position:0% +is also favorable because now we have +light coming in and this uh uh this + + align:start position:0% +light coming in and this uh uh this + + + align:start position:0% +light coming in and this uh uh this +generation current is driving the + + align:start position:0% +generation current is driving the + + + align:start position:0% +generation current is driving the +carriers or or is creating carriers here + + align:start position:0% +carriers or or is creating carriers here + + + align:start position:0% +carriers or or is creating carriers here +in the P type that can then be driven + + align:start position:0% +in the P type that can then be driven + + + align:start position:0% +in the P type that can then be driven +toward the N type because of the + + align:start position:0% +toward the N type because of the + + + align:start position:0% +toward the N type because of the +built-in field so the conditions are + + align:start position:0% +built-in field so the conditions are + + + align:start position:0% +built-in field so the conditions are +just right under illuminated forward + + align:start position:0% +just right under illuminated forward + + + align:start position:0% +just right under illuminated forward +bias conditions to drive power through + + align:start position:0% +bias conditions to drive power through + + + align:start position:0% +bias conditions to drive power through +our external load under all other + + align:start position:0% +our external load under all other + + + align:start position:0% +our external load under all other +conditions of operations of the solar + + align:start position:0% +conditions of operations of the solar + + + align:start position:0% +conditions of operations of the solar +cell we're putting power into the device + + align:start position:0% +cell we're putting power into the device + + + align:start position:0% +cell we're putting power into the device +not getting power out of it this fourth + + align:start position:0% +not getting power out of it this fourth + + + align:start position:0% +not getting power out of it this fourth +quadrant over here this forward bias + + align:start position:0% +quadrant over here this forward bias + + + align:start position:0% +quadrant over here this forward bias +illuminated case is the only case in + + align:start position:0% +illuminated case is the only case in + + + align:start position:0% +illuminated case is the only case in +which power is coming usable Powers + + align:start position:0% +which power is coming usable Powers + + + align:start position:0% +which power is coming usable Powers +coming out of our solar cell that we can + + align:start position:0% +coming out of our solar cell that we can + + + align:start position:0% +coming out of our solar cell that we can +use so that's why we focus on this + + align:start position:0% +use so that's why we focus on this + + + align:start position:0% +use so that's why we focus on this +fourth quadrant right here the + + align:start position:0% +fourth quadrant right here the + + + align:start position:0% +fourth quadrant right here the +illuminated IV curve is to first order + + align:start position:0% +illuminated IV curve is to first order + + + align:start position:0% +illuminated IV curve is to first order +is just your dark IV curve with a superp + + align:start position:0% +is just your dark IV curve with a superp + + + align:start position:0% +is just your dark IV curve with a superp +position which we call the illumination + + align:start position:0% +position which we call the illumination + + + align:start position:0% +position which we call the illumination +current I sub L and that's what shifts + + align:start position:0% +current I sub L and that's what shifts + + + align:start position:0% +current I sub L and that's what shifts +our entire curve down by this Isabel + + align:start position:0% +our entire curve down by this Isabel + + + align:start position:0% +our entire curve down by this Isabel +right here so this is subel that one + + align:start position:0% +right here so this is subel that one + + + align:start position:0% +right here so this is subel that one +right there or that one right + + align:start position:0% +right there or that one right + + + align:start position:0% +right there or that one right +there kind of cool all right uh what do + + align:start position:0% +there kind of cool all right uh what do + + + align:start position:0% +there kind of cool all right uh what do +we think will happen if our light + + align:start position:0% +we think will happen if our light + + + align:start position:0% +we think will happen if our light +intensity goes down by a factor of + + align:start position:0% +intensity goes down by a factor of + + + align:start position:0% +intensity goes down by a factor of +two so now if if if the amount of + + align:start position:0% +two so now if if if the amount of + + + align:start position:0% +two so now if if if the amount of +sunlight falling on our solar cell drops + + align:start position:0% +sunlight falling on our solar cell drops + + + align:start position:0% +sunlight falling on our solar cell drops +by a half what will happen what do we + + align:start position:0% +by a half what will happen what do we + + + align:start position:0% +by a half what will happen what do we +predict will happen based on this right + + align:start position:0% +predict will happen based on this right + + + align:start position:0% +predict will happen based on this right +here the Curve will shift the red Curve + + align:start position:0% +here the Curve will shift the red Curve + + + align:start position:0% +here the Curve will shift the red Curve +will shift up by about half right + + align:start position:0% +will shift up by about half right + + + align:start position:0% +will shift up by about half right +because the illumination current is now + + align:start position:0% +because the illumination current is now + + + align:start position:0% +because the illumination current is now +cut in + + align:start position:0% +cut in + + + align:start position:0% +cut in +half what will happen to the voltage + + align:start position:0% +half what will happen to the voltage + + + align:start position:0% +half what will happen to the voltage +intersect right + + align:start position:0% +intersect right + + + align:start position:0% +intersect right +here what is the relation between + + align:start position:0% +here what is the relation between + + + align:start position:0% +here what is the relation between +voltage and + + align:start position:0% +voltage and + + + align:start position:0% +voltage and +current it's a logarithmic relation + + align:start position:0% +current it's a logarithmic relation + + + align:start position:0% +current it's a logarithmic relation +right + + align:start position:0% +right + + + align:start position:0% +right +so it won't necessarily be cut in + + align:start position:0% +so it won't necessarily be cut in + + + align:start position:0% +so it won't necessarily be cut in +half right but it'll be cut by whatever + + align:start position:0% +half right but it'll be cut by whatever + + + align:start position:0% +half right but it'll be cut by whatever +this would be here log of log of two so + + align:start position:0% +this would be here log of log of two so + + + align:start position:0% +this would be here log of log of two so +um okay so we have we're beginning to + + align:start position:0% +um okay so we have we're beginning to + + + align:start position:0% +um okay so we have we're beginning to +develop an intuitive understanding of + + align:start position:0% +develop an intuitive understanding of + + + align:start position:0% +develop an intuitive understanding of +where electrons are flowing inside of + + align:start position:0% +where electrons are flowing inside of + + + align:start position:0% +where electrons are flowing inside of +our solar cells in the dark and under + + align:start position:0% +our solar cells in the dark and under + + + align:start position:0% +our solar cells in the dark and under +Illumination in the dark is important + + align:start position:0% +Illumination in the dark is important + + + align:start position:0% +Illumination in the dark is important +because we can test our devices in the + + align:start position:0% +because we can test our devices in the + + + align:start position:0% +because we can test our devices in the +dark and we can still learn a lot about + + align:start position:0% +dark and we can still learn a lot about + + + align:start position:0% +dark and we can still learn a lot about +our solar cell device characteristics in + + align:start position:0% +our solar cell device characteristics in + + + align:start position:0% +our solar cell device characteristics in +the dark as well we can under forward + + align:start position:0% +the dark as well we can under forward + + + align:start position:0% +the dark as well we can under forward +bias conditions in the dark we can force + + align:start position:0% +bias conditions in the dark we can force + + + align:start position:0% +bias conditions in the dark we can force +carriers from our uh from one side of + + align:start position:0% +carriers from our uh from one side of + + + align:start position:0% +carriers from our uh from one side of +the junction to the other the wrong way + + align:start position:0% +the junction to the other the wrong way + + + align:start position:0% +the junction to the other the wrong way +and probe for weaknesses in the P + + align:start position:0% +and probe for weaknesses in the P + + + align:start position:0% +and probe for weaknesses in the P +Junction region so that's helpful um and + + align:start position:0% +Junction region so that's helpful um and + + + align:start position:0% +Junction region so that's helpful um and +uh in the illumination condition + + align:start position:0% +uh in the illumination condition + + + align:start position:0% +uh in the illumination condition +obviously we're testing the total amount + + align:start position:0% +obviously we're testing the total amount + + + align:start position:0% +obviously we're testing the total amount +of power that's coming out of our device + + align:start position:0% +of power that's coming out of our device + + + align:start position:0% +of power that's coming out of our device +so again this is uh very useful because + + align:start position:0% +so again this is uh very useful because + + + align:start position:0% +so again this is uh very useful because +it's off of this red curve here that we + + align:start position:0% +it's off of this red curve here that we + + + align:start position:0% +it's off of this red curve here that we +Define the efficiency or the performance + + align:start position:0% +Define the efficiency or the performance + + + align:start position:0% +Define the efficiency or the performance +of the solar cell so what I'll ask folks + + align:start position:0% +of the solar cell so what I'll ask folks + + + align:start position:0% +of the solar cell so what I'll ask folks +to do now is to um uh we'll we'll begin + + align:start position:0% +to do now is to um uh we'll we'll begin + + + align:start position:0% +to do now is to um uh we'll we'll begin +passing around these little tools and + + align:start position:0% +passing around these little tools and + + + align:start position:0% +passing around these little tools and +I'll ask David Bernie needleman to come + + align:start position:0% +I'll ask David Bernie needleman to come + + + align:start position:0% +I'll ask David Bernie needleman to come +up to the front uh David is our our lab + + align:start position:0% +up to the front uh David is our our lab + + + align:start position:0% +up to the front uh David is our our lab +Guru he's the one who uh helped build + + align:start position:0% +Guru he's the one who uh helped build + + + align:start position:0% +Guru he's the one who uh helped build +these really was a driving force behind + + align:start position:0% +these really was a driving force behind + + + align:start position:0% +these really was a driving force behind +getting them built uh these are IV + + align:start position:0% +getting them built uh these are IV + + + align:start position:0% +getting them built uh these are IV +testers that will allow you to measure + + align:start position:0% +testers that will allow you to measure + + + align:start position:0% +testers that will allow you to measure +the current voltage characteristics of + + align:start position:0% +the current voltage characteristics of + + + align:start position:0% +the current voltage characteristics of +solar cells uh right here in class and + + align:start position:0% +solar cells uh right here in class and + + + align:start position:0% +solar cells uh right here in class and +uh he's going to well we'll pass them + + align:start position:0% +uh he's going to well we'll pass them + + + align:start position:0% +uh he's going to well we'll pass them +out while he maybe he comes to the front + + align:start position:0% +out while he maybe he comes to the front + + + align:start position:0% +out while he maybe he comes to the front +here and explains how they + + align:start position:0% + + + + align:start position:0% + +work so now that we have the basic IV + + align:start position:0% +work so now that we have the basic IV + + + align:start position:0% +work so now that we have the basic IV +curves rolling in what I'd like you to + + align:start position:0% +curves rolling in what I'd like you to + + + align:start position:0% +curves rolling in what I'd like you to +do is modify the height or the intensity + + align:start position:0% +do is modify the height or the intensity + + + align:start position:0% +do is modify the height or the intensity +of the light and the easiest way to + + align:start position:0% +of the light and the easiest way to + + + align:start position:0% +of the light and the easiest way to +modify the intensity of the light is to + + align:start position:0% +modify the intensity of the light is to + + + align:start position:0% +modify the intensity of the light is to +move the uh light position up and down + + align:start position:0% +move the uh light position up and down + + + align:start position:0% +move the uh light position up and down +right so uh modify the intensity of the + + align:start position:0% +right so uh modify the intensity of the + + + align:start position:0% +right so uh modify the intensity of the +light and see how this IV curve changes + + align:start position:0% +light and see how this IV curve changes + + + align:start position:0% +light and see how this IV curve changes +note the uh y-axis scale which might uh + + align:start position:0% +note the uh y-axis scale which might uh + + + align:start position:0% +note the uh y-axis scale which might uh +might change as well it might rescale uh + + align:start position:0% +might change as well it might rescale uh + + + align:start position:0% +might change as well it might rescale uh +depending on the condition uh but note + + align:start position:0% +depending on the condition uh but note + + + align:start position:0% +depending on the condition uh but note +the y-axis scale and see how the um uh + + align:start position:0% +the y-axis scale and see how the um uh + + + align:start position:0% +the y-axis scale and see how the um uh +The Intercept of the of the y axis is + + align:start position:0% +The Intercept of the of the y axis is + + + align:start position:0% +The Intercept of the of the y axis is +changed with illumination intensity give + + align:start position:0% +changed with illumination intensity give + + + align:start position:0% +changed with illumination intensity give +that a + + align:start position:0% + + + + align:start position:0% + +shot all right + + align:start position:0% +shot all right + + + align:start position:0% +shot all right +folks why don't we uh why don't we + + align:start position:0% +folks why don't we uh why don't we + + + align:start position:0% +folks why don't we uh why don't we +Circle back real quick um this has been + + align:start position:0% +Circle back real quick um this has been + + + align:start position:0% +Circle back real quick um this has been +a good experiment I uh am very much uh + + align:start position:0% +a good experiment I uh am very much uh + + + align:start position:0% +a good experiment I uh am very much uh +in favor of multitasking and browsing so + + align:start position:0% +in favor of multitasking and browsing so + + + align:start position:0% +in favor of multitasking and browsing so +if you want to keep your experiment + + align:start position:0% +if you want to keep your experiment + + + align:start position:0% +if you want to keep your experiment +running over the course of the remainder + + align:start position:0% +running over the course of the remainder + + + align:start position:0% +running over the course of the remainder +the lecture I will certainly have + + align:start position:0% +the lecture I will certainly have + + + align:start position:0% +the lecture I will certainly have +nothing opposed to uh testing a few + + align:start position:0% +nothing opposed to uh testing a few + + + align:start position:0% +nothing opposed to uh testing a few +different elimination conditions and if + + align:start position:0% +different elimination conditions and if + + + align:start position:0% +different elimination conditions and if +there's anything really really important + + align:start position:0% +there's anything really really important + + + align:start position:0% +there's anything really really important +I'm going to emphasize this is really + + align:start position:0% +I'm going to emphasize this is really + + + align:start position:0% +I'm going to emphasize this is really +important wake up folks um the I sub L + + align:start position:0% +important wake up folks um the I sub L + + + align:start position:0% +important wake up folks um the I sub L +just to really recap here we have this + + align:start position:0% +just to really recap here we have this + + + align:start position:0% +just to really recap here we have this +ideal di equation the illumination + + align:start position:0% +ideal di equation the illumination + + + align:start position:0% +ideal di equation the illumination +current coming in from our light source + + align:start position:0% +current coming in from our light source + + + align:start position:0% +current coming in from our light source +and in our little setup how many + + align:start position:0% +and in our little setup how many + + + align:start position:0% +and in our little setup how many +batteries did you see + + align:start position:0% +batteries did you see + + + align:start position:0% +batteries did you see +there look closer how many batteries do + + align:start position:0% +there look closer how many batteries do + + + align:start position:0% +there look closer how many batteries do +you see total in our in our setup look + + align:start position:0% +you see total in our in our setup look + + + align:start position:0% +you see total in our in our setup look +at especially at that light source two + + align:start position:0% +at especially at that light source two + + + align:start position:0% +at especially at that light source two +of them right there's a 9vt and a 1.5 + + align:start position:0% +of them right there's a 9vt and a 1.5 + + + align:start position:0% +of them right there's a 9vt and a 1.5 +volt all right so one of them is + + align:start position:0% +volt all right so one of them is + + + align:start position:0% +volt all right so one of them is +powering the light source and uh we have + + align:start position:0% +powering the light source and uh we have + + + align:start position:0% +powering the light source and uh we have +um as well bias uh to the solar cell + + align:start position:0% +um as well bias uh to the solar cell + + + align:start position:0% +um as well bias uh to the solar cell +device right so we have a bit of a + + align:start position:0% +device right so we have a bit of a + + + align:start position:0% +device right so we have a bit of a +combination of the last two uh slides + + align:start position:0% +combination of the last two uh slides + + + align:start position:0% +combination of the last two uh slides +right in this case we had the in the + + align:start position:0% +right in this case we had the in the + + + align:start position:0% +right in this case we had the in the +dark we were biasing our solar cell + + align:start position:0% +dark we were biasing our solar cell + + + align:start position:0% +dark we were biasing our solar cell +using the battery and under illumination + + align:start position:0% +using the battery and under illumination + + + align:start position:0% +using the battery and under illumination +conditions uh the light itself was + + align:start position:0% +conditions uh the light itself was + + + align:start position:0% +conditions uh the light itself was +causing the solar cell to become forward + + align:start position:0% +causing the solar cell to become forward + + + align:start position:0% +causing the solar cell to become forward +biased but we can add a battery to sweep + + align:start position:0% +biased but we can add a battery to sweep + + + align:start position:0% +biased but we can add a battery to sweep +the uh the bias condition of the device + + align:start position:0% +the uh the bias condition of the device + + + align:start position:0% +the uh the bias condition of the device +right so even though we have a natural + + align:start position:0% +right so even though we have a natural + + + align:start position:0% +right so even though we have a natural +biasing of the of the solar cell By the + + align:start position:0% +biasing of the of the solar cell By the + + + align:start position:0% +biasing of the of the solar cell By the +Light we can force the solar cell under + + align:start position:0% +Light we can force the solar cell under + + + align:start position:0% +Light we can force the solar cell under +different operating conditions with the + + align:start position:0% +different operating conditions with the + + + align:start position:0% +different operating conditions with the +battery and so that's effectively what's + + align:start position:0% +battery and so that's effectively what's + + + align:start position:0% +battery and so that's effectively what's +happening right here is you have a + + align:start position:0% +happening right here is you have a + + + align:start position:0% +happening right here is you have a +combination of + + align:start position:0% +combination of + + + align:start position:0% +combination of +both uh uh simple scenarios that we just + + align:start position:0% +both uh uh simple scenarios that we just + + + align:start position:0% +both uh uh simple scenarios that we just +looked at and uh we're building on on + + align:start position:0% +looked at and uh we're building on on + + + align:start position:0% +looked at and uh we're building on on +those components to really understand uh + + align:start position:0% +those components to really understand uh + + + align:start position:0% +those components to really understand uh +the larger system um why might that be + + align:start position:0% +the larger system um why might that be + + + align:start position:0% +the larger system um why might that be +important or why might that be realistic + + align:start position:0% +important or why might that be realistic + + + align:start position:0% +important or why might that be realistic +well uh the light itself is biasing that + + align:start position:0% +well uh the light itself is biasing that + + + align:start position:0% +well uh the light itself is biasing that +particular solar cell device but that + + align:start position:0% +particular solar cell device but that + + + align:start position:0% +particular solar cell device but that +solar cell might be connected in series + + align:start position:0% +solar cell might be connected in series + + + align:start position:0% +solar cell might be connected in series +with a bunch of other solar cells in a + + align:start position:0% +with a bunch of other solar cells in a + + + align:start position:0% +with a bunch of other solar cells in a +module right and those other solar cells + + align:start position:0% +module right and those other solar cells + + + align:start position:0% +module right and those other solar cells +might be biasing that one uh solar cell + + align:start position:0% +might be biasing that one uh solar cell + + + align:start position:0% +might be biasing that one uh solar cell +so uh that's why we we we have to think + + align:start position:0% +so uh that's why we we we have to think + + + align:start position:0% +so uh that's why we we we have to think +about uh the solar cell device both from + + align:start position:0% +about uh the solar cell device both from + + + align:start position:0% +about uh the solar cell device both from +the perspective of of what bias + + align:start position:0% +the perspective of of what bias + + + align:start position:0% +the perspective of of what bias +condition is it under what illumination + + align:start position:0% +condition is it under what illumination + + + align:start position:0% +condition is it under what illumination +is it under and of course what's + + align:start position:0% +is it under and of course what's + + + align:start position:0% +is it under and of course what's +happening around it is it just powering + + align:start position:0% +happening around it is it just powering + + + align:start position:0% +happening around it is it just powering +external load are there is there a + + align:start position:0% +external load are there is there a + + + align:start position:0% +external load are there is there a +battery connected in series to it are + + align:start position:0% +battery connected in series to it are + + + align:start position:0% +battery connected in series to it are +there other solar cells connected in + + align:start position:0% +there other solar cells connected in + + + align:start position:0% +there other solar cells connected in +series with it okay yes Ashley so I I + + align:start position:0% +series with it okay yes Ashley so I I + + + align:start position:0% +series with it okay yes Ashley so I I +don't understand still why having a load + + align:start position:0% +don't understand still why having a load + + + align:start position:0% +don't understand still why having a load +would bias the device yeah so let's + + align:start position:0% +would bias the device yeah so let's + + + align:start position:0% +would bias the device yeah so let's +imagine uh under illumination conditions + + align:start position:0% +imagine uh under illumination conditions + + + align:start position:0% +imagine uh under illumination conditions +right here what I'm going to do very + + align:start position:0% +right here what I'm going to do very + + + align:start position:0% +right here what I'm going to do very +very quickly is replace this battery um + + align:start position:0% +very quickly is replace this battery um + + + align:start position:0% +very quickly is replace this battery um +manually in my slides if PowerPoint auto + + align:start position:0% +manually in my slides if PowerPoint auto + + + align:start position:0% +manually in my slides if PowerPoint auto +save will allow me with a resistor so um + + align:start position:0% +save will allow me with a resistor so um + + + align:start position:0% +save will allow me with a resistor so um +if you'll excuse my quick uh + + align:start position:0% +if you'll excuse my quick uh + + + align:start position:0% +if you'll excuse my quick uh +introduction here of the + + align:start position:0% +introduction here of the + + + align:start position:0% +introduction here of the +resistor now um sorry about the little + + align:start position:0% +resistor now um sorry about the little + + + align:start position:0% +resistor now um sorry about the little +artistic uh license okay so now I have + + align:start position:0% +artistic uh license okay so now I have + + + align:start position:0% +artistic uh license okay so now I have +my resistor here and um my illumination + + align:start position:0% +my resistor here and um my illumination + + + align:start position:0% +my resistor here and um my illumination +is coming into the device uh from say + + align:start position:0% +is coming into the device uh from say + + + align:start position:0% +is coming into the device uh from say +one of the sides is generating electron + + align:start position:0% +one of the sides is generating electron + + + align:start position:0% +one of the sides is generating electron +ho pairs I have a a multiplicity of + + align:start position:0% +ho pairs I have a a multiplicity of + + + align:start position:0% +ho pairs I have a a multiplicity of +electrons that have now gone down the + + align:start position:0% +electrons that have now gone down the + + + align:start position:0% +electrons that have now gone down the +hill right it's more energetically + + align:start position:0% +hill right it's more energetically + + + align:start position:0% +hill right it's more energetically +favorable for these electrons to be on + + align:start position:0% +favorable for these electrons to be on + + + align:start position:0% +favorable for these electrons to be on +the other side and what has that done + + align:start position:0% +the other side and what has that done + + + align:start position:0% +the other side and what has that done +that's raised the chemical potential + + align:start position:0% +that's raised the chemical potential + + + align:start position:0% +that's raised the chemical potential +this side it's difficult for them to get + + align:start position:0% +this side it's difficult for them to get + + + align:start position:0% +this side it's difficult for them to get +back the other way um it's not + + align:start position:0% +back the other way um it's not + + + align:start position:0% +back the other way um it's not +impossible but it could be more easy for + + align:start position:0% +impossible but it could be more easy for + + + align:start position:0% +impossible but it could be more easy for +them to flow through an external circuit + + align:start position:0% +them to flow through an external circuit + + + align:start position:0% +them to flow through an external circuit +to get back to the other side and as + + align:start position:0% +to get back to the other side and as + + + align:start position:0% +to get back to the other side and as +they flow through that external circuit + + align:start position:0% +they flow through that external circuit + + + align:start position:0% +they flow through that external circuit +they're depositing their energy across + + align:start position:0% +they're depositing their energy across + + + align:start position:0% +they're depositing their energy across +that external circuit what energy well + + align:start position:0% +that external circuit what energy well + + + align:start position:0% +that external circuit what energy well +it's the potential difference from this + + align:start position:0% +it's the potential difference from this + + + align:start position:0% +it's the potential difference from this +side to that + + align:start position:0% +side to that + + + align:start position:0% +side to that +side so that's why the solar cell can be + + align:start position:0% +side so that's why the solar cell can be + + + align:start position:0% +side so that's why the solar cell can be +thought of as under as in fored byas + + align:start position:0% +thought of as under as in fored byas + + + align:start position:0% +thought of as under as in fored byas +conditions under illumination with an + + align:start position:0% +conditions under illumination with an + + + align:start position:0% +conditions under illumination with an +external load attached to it of course + + align:start position:0% +external load attached to it of course + + + align:start position:0% +external load attached to it of course +the load has to be well matched to the + + align:start position:0% +the load has to be well matched to the + + + align:start position:0% +the load has to be well matched to the +uh output of the solar cell device and + + align:start position:0% +uh output of the solar cell device and + + + align:start position:0% +uh output of the solar cell device and +is the biasing because there's a voltage + + align:start position:0% +is the biasing because there's a voltage + + + align:start position:0% +is the biasing because there's a voltage +drop across the resistor uh yes the + + align:start position:0% +drop across the resistor uh yes the + + + align:start position:0% +drop across the resistor uh yes the +biasing is because you have a shift in + + align:start position:0% +biasing is because you have a shift in + + + align:start position:0% +biasing is because you have a shift in +the chemical potential of this side up + + align:start position:0% +the chemical potential of this side up + + + align:start position:0% +the chemical potential of this side up +relative to you have a shift of the N + + align:start position:0% +relative to you have a shift of the N + + + align:start position:0% +relative to you have a shift of the N +type side higher than the ptype side + + align:start position:0% +type side higher than the ptype side + + + align:start position:0% +type side higher than the ptype side +that's a bias anytime you have a + + align:start position:0% +that's a bias anytime you have a + + + align:start position:0% +that's a bias anytime you have a +difference in the chemical potential in + + align:start position:0% +difference in the chemical potential in + + + align:start position:0% +difference in the chemical potential in +one terminal versus the other terminal + + align:start position:0% +one terminal versus the other terminal + + + align:start position:0% +one terminal versus the other terminal +of your solar cell you have a bias + + align:start position:0% +of your solar cell you have a bias + + + align:start position:0% +of your solar cell you have a bias +whether that's generated by light + + align:start position:0% +whether that's generated by light + + + align:start position:0% +whether that's generated by light +whether that's generated by a battery + + align:start position:0% +whether that's generated by a battery + + + align:start position:0% +whether that's generated by a battery +right whether it's the energy input to + + align:start position:0% +right whether it's the energy input to + + + align:start position:0% +right whether it's the energy input to +create that bias is coming from the Sun + + align:start position:0% +create that bias is coming from the Sun + + + align:start position:0% +create that bias is coming from the Sun +or if it's coming from an external + + align:start position:0% +or if it's coming from an external + + + align:start position:0% +or if it's coming from an external +battery uh that's a matter of of detail + + align:start position:0% +battery uh that's a matter of of detail + + + align:start position:0% +battery uh that's a matter of of detail +so okay so is the Sun for biasing yes + + align:start position:0% +so okay so is the Sun for biasing yes + + + align:start position:0% +so okay so is the Sun for biasing yes +one can think about this as talking I + + align:start position:0% +one can think about this as talking I + + + align:start position:0% +one can think about this as talking I +conf between light and like okay oh so + + align:start position:0% +conf between light and like okay oh so + + + align:start position:0% +conf between light and like okay oh so +the LED in this case could forward bias + + align:start position:0% +the LED in this case could forward bias + + + align:start position:0% +the LED in this case could forward bias +your device too I mean it's just photons + + align:start position:0% +your device too I mean it's just photons + + + align:start position:0% +your device too I mean it's just photons +photons are are forward biasing the + + align:start position:0% +photons are are forward biasing the + + + align:start position:0% +photons are are forward biasing the +device yeah so then can Sun ever reverse + + align:start position:0% +device yeah so then can Sun ever reverse + + + align:start position:0% +device yeah so then can Sun ever reverse +bias no that would be very difficult um + + align:start position:0% +bias no that would be very difficult um + + + align:start position:0% +bias no that would be very difficult um +what you could what you could do though + + align:start position:0% +what you could what you could do though + + + align:start position:0% +what you could what you could do though +is have a bunch of solar cells connected + + align:start position:0% +is have a bunch of solar cells connected + + + align:start position:0% +is have a bunch of solar cells connected +in series with this one right that are + + align:start position:0% +in series with this one right that are + + + align:start position:0% +in series with this one right that are +producing forward power you could shade + + align:start position:0% +producing forward power you could shade + + + align:start position:0% +producing forward power you could shade +this device and then power could be + + align:start position:0% +this device and then power could be + + + align:start position:0% +this device and then power could be +flowing backward through it right in + + align:start position:0% +flowing backward through it right in + + + align:start position:0% +flowing backward through it right in +other words it could be in the dark + + align:start position:0% +other words it could be in the dark + + + align:start position:0% +other words it could be in the dark +right here in a dark condition and you + + align:start position:0% +right here in a dark condition and you + + + align:start position:0% +right here in a dark condition and you +could be in a reverse bias condition + + align:start position:0% +could be in a reverse bias condition + + + align:start position:0% +could be in a reverse bias condition +just because of uh the way the other + + align:start position:0% +just because of uh the way the other + + + align:start position:0% +just because of uh the way the other +solar cells around it are behaving if + + align:start position:0% +solar cells around it are behaving if + + + align:start position:0% +solar cells around it are behaving if +you have a shaded solar cell for example + + align:start position:0% +you have a shaded solar cell for example + + + align:start position:0% +you have a shaded solar cell for example +a module so imagine a seagull lands and + + align:start position:0% +a module so imagine a seagull lands and + + + align:start position:0% +a module so imagine a seagull lands and +kind of covers up one of the cells um + + align:start position:0% +kind of covers up one of the cells um + + + align:start position:0% +kind of covers up one of the cells um +that will be under reverse bias um and + + align:start position:0% +that will be under reverse bias um and + + + align:start position:0% +that will be under reverse bias um and +that that could present problem if the + + align:start position:0% +that that could present problem if the + + + align:start position:0% +that that could present problem if the +uh solar cell can't withstand uh the + + align:start position:0% +uh solar cell can't withstand uh the + + + align:start position:0% +uh solar cell can't withstand uh the +reverse bias not this is a very ideal + + align:start position:0% +reverse bias not this is a very ideal + + + align:start position:0% +reverse bias not this is a very ideal +condition what happens in the real world + + align:start position:0% +condition what happens in the real world + + + align:start position:0% +condition what happens in the real world +is that at some reverse bias condition + + align:start position:0% +is that at some reverse bias condition + + + align:start position:0% +is that at some reverse bias condition +you just have biased it so much that + + align:start position:0% +you just have biased it so much that + + + align:start position:0% +you just have biased it so much that +electrons will be able to Tunnel through + + align:start position:0% +electrons will be able to Tunnel through + + + align:start position:0% +electrons will be able to Tunnel through +from the P type into the N type right + + align:start position:0% +from the P type into the N type right + + + align:start position:0% +from the P type into the N type right +here the electrons in the veence band + + align:start position:0% +here the electrons in the veence band + + + align:start position:0% +here the electrons in the veence band +will be able to Tunnel through into the + + align:start position:0% +will be able to Tunnel through into the + + + align:start position:0% +will be able to Tunnel through into the +conduction band and what happens this IV + + align:start position:0% +conduction band and what happens this IV + + + align:start position:0% +conduction band and what happens this IV +curve is it goes Zoom begins dropping so + + align:start position:0% +curve is it goes Zoom begins dropping so + + + align:start position:0% +curve is it goes Zoom begins dropping so +if the solar cell uh reverse bias uh uh + + align:start position:0% +if the solar cell uh reverse bias uh uh + + + align:start position:0% +if the solar cell uh reverse bias uh uh +see the reverse bias current um or the + + align:start position:0% +see the reverse bias current um or the + + + align:start position:0% +see the reverse bias current um or the +current at reverse bias voltage is not + + align:start position:0% +current at reverse bias voltage is not + + + align:start position:0% +current at reverse bias voltage is not +low enough in other words if the P + + align:start position:0% +low enough in other words if the P + + + align:start position:0% +low enough in other words if the P +injunction is not strong enough you + + align:start position:0% +injunction is not strong enough you + + + align:start position:0% +injunction is not strong enough you +could have a catastrophic failure of + + align:start position:0% +could have a catastrophic failure of + + + align:start position:0% +could have a catastrophic failure of +your module with by just shading one of + + align:start position:0% +your module with by just shading one of + + + align:start position:0% +your module with by just shading one of +your cell thankfully this is one of the + + align:start position:0% +your cell thankfully this is one of the + + + align:start position:0% +your cell thankfully this is one of the +testings that are done uh with the solar + + align:start position:0% +testings that are done uh with the solar + + + align:start position:0% +testings that are done uh with the solar +simulator to prevent that failure mode + + align:start position:0% +simulator to prevent that failure mode + + + align:start position:0% +simulator to prevent that failure mode +okay all right I'll I'll entertain + + align:start position:0% +okay all right I'll I'll entertain + + + align:start position:0% +okay all right I'll I'll entertain +deeper Dives with questions I'll try to + + align:start position:0% +deeper Dives with questions I'll try to + + + align:start position:0% +deeper Dives with questions I'll try to +keep the lecture focused on the broader + + align:start position:0% +keep the lecture focused on the broader + + + align:start position:0% +keep the lecture focused on the broader +General topics but if somebody is + + align:start position:0% +General topics but if somebody is + + + align:start position:0% +General topics but if somebody is +interested in in uh in learning more I'm + + align:start position:0% +interested in in uh in learning more I'm + + + align:start position:0% +interested in in uh in learning more I'm +happy to kind of dive into there all + + align:start position:0% +happy to kind of dive into there all + + + align:start position:0% +happy to kind of dive into there all +right so um readings are strong + + align:start position:0% +right so um readings are strong + + + align:start position:0% +right so um readings are strong +encouraged I have uh interacted with + + align:start position:0% +encouraged I have uh interacted with + + + align:start position:0% +encouraged I have uh interacted with +several of you Joe has interacted with + + align:start position:0% +several of you Joe has interacted with + + + align:start position:0% +several of you Joe has interacted with +probably three n uh ending the number of + + align:start position:0% +probably three n uh ending the number of + + + align:start position:0% +probably three n uh ending the number of +people I've interacted with so far um + + align:start position:0% +people I've interacted with so far um + + + align:start position:0% +people I've interacted with so far um +and really try to uh impart the wisdom + + align:start position:0% +and really try to uh impart the wisdom + + + align:start position:0% +and really try to uh impart the wisdom +of p and Junction so uh please please + + align:start position:0% +of p and Junction so uh please please + + + align:start position:0% +of p and Junction so uh please please +please come to us if if still things are + + align:start position:0% +please come to us if if still things are + + + align:start position:0% +please come to us if if still things are +going over your head you should be able + + align:start position:0% +going over your head you should be able + + + align:start position:0% +going over your head you should be able +to explain to your uh roommates uh + + align:start position:0% +to explain to your uh roommates uh + + + align:start position:0% +to explain to your uh roommates uh +exactly what is going on in a p + + align:start position:0% +exactly what is going on in a p + + + align:start position:0% +exactly what is going on in a p +injunction Define parameters that + + align:start position:0% +injunction Define parameters that + + + align:start position:0% +injunction Define parameters that +determine solar cell efficiency so now + + align:start position:0% +determine solar cell efficiency so now + + + align:start position:0% +determine solar cell efficiency so now +we have a qualitative sense about where + + align:start position:0% +we have a qualitative sense about where + + + align:start position:0% +we have a qualitative sense about where +current is Flowing where electrons are + + align:start position:0% +current is Flowing where electrons are + + + align:start position:0% +current is Flowing where electrons are +moving around um what defines uh the + + align:start position:0% +moving around um what defines uh the + + + align:start position:0% +moving around um what defines uh the +power output how the power output is + + align:start position:0% +power output how the power output is + + + align:start position:0% +power output how the power output is +changing with illumination condition + + align:start position:0% +changing with illumination condition + + + align:start position:0% +changing with illumination condition +we're getting an intuitive sense of all + + align:start position:0% +we're getting an intuitive sense of all + + + align:start position:0% +we're getting an intuitive sense of all +of this let's start putting some discret + + align:start position:0% +of this let's start putting some discret + + + align:start position:0% +of this let's start putting some discret +variables to all of that um and there + + align:start position:0% +variables to all of that um and there + + + align:start position:0% +variables to all of that um and there +are a bunch of of of two-letter or + + align:start position:0% +are a bunch of of of two-letter or + + + align:start position:0% +are a bunch of of of two-letter or +three-letter acronyms with some + + align:start position:0% +three-letter acronyms with some + + + align:start position:0% +three-letter acronyms with some +subscripts here that uh we'll get to + + align:start position:0% +subscripts here that uh we'll get to + + + align:start position:0% +subscripts here that uh we'll get to +know uh we'll become very familiar with + + align:start position:0% +know uh we'll become very familiar with + + + align:start position:0% +know uh we'll become very familiar with +over the next few lectures so um How is + + align:start position:0% +over the next few lectures so um How is + + + align:start position:0% +over the next few lectures so um How is +solar cell conversion efficiency + + align:start position:0% +solar cell conversion efficiency + + + align:start position:0% +solar cell conversion efficiency +determinated determined from that + + align:start position:0% +determinated determined from that + + + align:start position:0% +determinated determined from that +illuminated IV curve that's our first + + align:start position:0% +illuminated IV curve that's our first + + + align:start position:0% +illuminated IV curve that's our first +question and um what I'm going to do is + + align:start position:0% +question and um what I'm going to do is + + + align:start position:0% +question and um what I'm going to do is +start with our uh solar cell IV curve + + align:start position:0% +start with our uh solar cell IV curve + + + align:start position:0% +start with our uh solar cell IV curve +right here this is just the fourth + + align:start position:0% +right here this is just the fourth + + + align:start position:0% +right here this is just the fourth +quadrant okay so notice the current + + align:start position:0% +quadrant okay so notice the current + + + align:start position:0% +quadrant okay so notice the current +starts at zero and goes to some negative + + align:start position:0% +starts at zero and goes to some negative + + + align:start position:0% +starts at zero and goes to some negative +values so we're looking in the fourth + + align:start position:0% +values so we're looking in the fourth + + + align:start position:0% +values so we're looking in the fourth +quadrant voltage is going from zero to + + align:start position:0% +quadrant voltage is going from zero to + + + align:start position:0% +quadrant voltage is going from zero to +positive value so again fourth quadrant + + align:start position:0% +positive value so again fourth quadrant + + + align:start position:0% +positive value so again fourth quadrant +we have our uh our ideal diode equation + + align:start position:0% +we have our uh our ideal diode equation + + + align:start position:0% +we have our uh our ideal diode equation +here and oh notice one thing I just + + align:start position:0% +here and oh notice one thing I just + + + align:start position:0% +here and oh notice one thing I just +changed I to J what just happened well I + + align:start position:0% +changed I to J what just happened well I + + + align:start position:0% +changed I to J what just happened well I +and J look very similar but uh they're + + align:start position:0% +and J look very similar but uh they're + + + align:start position:0% +and J look very similar but uh they're +in fact two different variables um most + + align:start position:0% +in fact two different variables um most + + + align:start position:0% +in fact two different variables um most +often PV research will report a current + + align:start position:0% +often PV research will report a current + + + align:start position:0% +often PV research will report a current +density in other words a current per + + align:start position:0% +density in other words a current per + + + align:start position:0% +density in other words a current per +unit area instead of the actual current + + align:start position:0% +unit area instead of the actual current + + + align:start position:0% +unit area instead of the actual current +coming out of the solar cell device so + + align:start position:0% +coming out of the solar cell device so + + + align:start position:0% +coming out of the solar cell device so +what you've been measuring here off of + + align:start position:0% +what you've been measuring here off of + + + align:start position:0% +what you've been measuring here off of +the off of the deck has been current + + align:start position:0% +the off of the deck has been current + + + align:start position:0% +the off of the deck has been current +total current output from that device + + align:start position:0% +total current output from that device + + + align:start position:0% +total current output from that device +and it might be a really tiny number and + + align:start position:0% +and it might be a really tiny number and + + + align:start position:0% +and it might be a really tiny number and +it might be difficult to compare against + + align:start position:0% +it might be difficult to compare against + + + align:start position:0% +it might be difficult to compare against +other size devices and so what solar + + align:start position:0% +other size devices and so what solar + + + align:start position:0% +other size devices and so what solar +cell researchers often do is they say + + align:start position:0% +cell researchers often do is they say + + + align:start position:0% +cell researchers often do is they say +okay let's normalize the current by the + + align:start position:0% +okay let's normalize the current by the + + + align:start position:0% +okay let's normalize the current by the +area to get a current density and we'll + + align:start position:0% +area to get a current density and we'll + + + align:start position:0% +area to get a current density and we'll +call current density J and we'll call + + align:start position:0% +call current density J and we'll call + + + align:start position:0% +call current density J and we'll call +current I right so if we're calculating + + align:start position:0% +current I right so if we're calculating + + + align:start position:0% +current I right so if we're calculating +power we'll have to use I I we have to + + align:start position:0% +power we'll have to use I I we have to + + + align:start position:0% +power we'll have to use I I we have to +multiply I * V but if we're just looking + + align:start position:0% +multiply I * V but if we're just looking + + + align:start position:0% +multiply I * V but if we're just looking +at uh one solar cell versus another uh + + align:start position:0% +at uh one solar cell versus another uh + + + align:start position:0% +at uh one solar cell versus another uh +we can use J as a very convenient way of + + align:start position:0% +we can use J as a very convenient way of + + + align:start position:0% +we can use J as a very convenient way of +comparing one solar cell versus another + + align:start position:0% +comparing one solar cell versus another + + + align:start position:0% +comparing one solar cell versus another +cool okay so um the illuminated AV curve + + align:start position:0% +cool okay so um the illuminated AV curve + + + align:start position:0% +cool okay so um the illuminated AV curve +looks something like this right it's in + + align:start position:0% +looks something like this right it's in + + + align:start position:0% +looks something like this right it's in +the fourth quadrant it goes out a + + align:start position:0% +the fourth quadrant it goes out a + + + align:start position:0% +the fourth quadrant it goes out a +certain amount then it curves up we just + + align:start position:0% +certain amount then it curves up we just + + + align:start position:0% +certain amount then it curves up we just +determined that uh here in class and + + align:start position:0% +determined that uh here in class and + + + align:start position:0% +determined that uh here in class and +that's essentially the ideal diet + + align:start position:0% +that's essentially the ideal diet + + + align:start position:0% +that's essentially the ideal diet +equation with a superposition term this + + align:start position:0% +equation with a superposition term this + + + align:start position:0% +equation with a superposition term this +J sub L right there so um let's parse + + align:start position:0% +J sub L right there so um let's parse + + + align:start position:0% +J sub L right there so um let's parse +through + + align:start position:0% +through + + + align:start position:0% +through +we have the Y intercept over here at the + + align:start position:0% +we have the Y intercept over here at the + + + align:start position:0% +we have the Y intercept over here at the +Y intercept there is maximum current + + align:start position:0% +Y intercept there is maximum current + + + align:start position:0% +Y intercept there is maximum current +flowing through the circuit but no power + + align:start position:0% +flowing through the circuit but no power + + + align:start position:0% +flowing through the circuit but no power +because voltage is equal to zero so + + align:start position:0% +because voltage is equal to zero so + + + align:start position:0% +because voltage is equal to zero so +remember the firmy energy is the same on + + align:start position:0% +remember the firmy energy is the same on + + + align:start position:0% +remember the firmy energy is the same on +either side the chemical potential is + + align:start position:0% +either side the chemical potential is + + + align:start position:0% +either side the chemical potential is +the same on either side of the device so + + align:start position:0% +the same on either side of the device so + + + align:start position:0% +the same on either side of the device so +there's no uh energy gain of the + + align:start position:0% +there's no uh energy gain of the + + + align:start position:0% +there's no uh energy gain of the +electron traveling through the external + + align:start position:0% +electron traveling through the external + + + align:start position:0% +electron traveling through the external +circuit but uh there's a maximum current + + align:start position:0% +circuit but uh there's a maximum current + + + align:start position:0% +circuit but uh there's a maximum current +uh and no power flowing through that + + align:start position:0% +uh and no power flowing through that + + + align:start position:0% +uh and no power flowing through that +external circuit because there's no + + align:start position:0% +external circuit because there's no + + + align:start position:0% +external circuit because there's no +potential to be dropped across the + + align:start position:0% +potential to be dropped across the + + + align:start position:0% +potential to be dropped across the +external resistor the opposite happens + + align:start position:0% +external resistor the opposite happens + + + align:start position:0% +external resistor the opposite happens +over here at this point called VOC which + + align:start position:0% +over here at this point called VOC which + + + align:start position:0% +over here at this point called VOC which +we'll call open circuit voltage the OC + + align:start position:0% +we'll call open circuit voltage the OC + + + align:start position:0% +we'll call open circuit voltage the OC +stands for open circuit V voltage open + + align:start position:0% +stands for open circuit V voltage open + + + align:start position:0% +stands for open circuit V voltage open +circuit voltage is just as you would + + align:start position:0% +circuit voltage is just as you would + + + align:start position:0% +circuit voltage is just as you would +think it is uh when your solar cell is + + align:start position:0% +think it is uh when your solar cell is + + + align:start position:0% +think it is uh when your solar cell is +in an open circuit when you say you took + + align:start position:0% +in an open circuit when you say you took + + + align:start position:0% +in an open circuit when you say you took +a SC pair of scissors please don't do + + align:start position:0% +a SC pair of scissors please don't do + + + align:start position:0% +a SC pair of scissors please don't do +this and cut the leads so that your + + align:start position:0% +this and cut the leads so that your + + + align:start position:0% +this and cut the leads so that your +solar cell wasn't uh uh outputting the + + align:start position:0% +solar cell wasn't uh uh outputting the + + + align:start position:0% +solar cell wasn't uh uh outputting the +current through an external load there + + align:start position:0% +current through an external load there + + + align:start position:0% +current through an external load there +would be a a bias voltage built up + + align:start position:0% +would be a a bias voltage built up + + + align:start position:0% +would be a a bias voltage built up +across the the P and the end side of the + + align:start position:0% +across the the P and the end side of the + + + align:start position:0% +across the the P and the end side of the +solar cell and it would be the maximum + + align:start position:0% +solar cell and it would be the maximum + + + align:start position:0% +solar cell and it would be the maximum +voltage that could be supported by that + + align:start position:0% +voltage that could be supported by that + + + align:start position:0% +voltage that could be supported by that +solar cell device under illumination + + align:start position:0% +solar cell device under illumination + + + align:start position:0% +solar cell device under illumination +conditions that's the open circuit + + align:start position:0% +conditions that's the open circuit + + + align:start position:0% +conditions that's the open circuit +voltage open circuit because there's no + + align:start position:0% +voltage open circuit because there's no + + + align:start position:0% +voltage open circuit because there's no +current again traveling through the + + align:start position:0% +current again traveling through the + + + align:start position:0% +current again traveling through the +external circuit that's why current is + + align:start position:0% +external circuit that's why current is + + + align:start position:0% +external circuit that's why current is +zero right open circuit and voltage um + + align:start position:0% +zero right open circuit and voltage um + + + align:start position:0% +zero right open circuit and voltage um +because this is well it's interesting + + align:start position:0% +because this is well it's interesting + + + align:start position:0% +because this is well it's interesting +point because it's the maximum voltage + + align:start position:0% +point because it's the maximum voltage + + + align:start position:0% +point because it's the maximum voltage +here uh represented in the fourth + + align:start position:0% +here uh represented in the fourth + + + align:start position:0% +here uh represented in the fourth +quadrant and somewhere in between uh the + + align:start position:0% +quadrant and somewhere in between uh the + + + align:start position:0% +quadrant and somewhere in between uh the +point of open circuit voltage and short + + align:start position:0% +point of open circuit voltage and short + + + align:start position:0% +point of open circuit voltage and short +circuit current short circuit current + + align:start position:0% +circuit current short circuit current + + + align:start position:0% +circuit current short circuit current +again because you're short circu in your + + align:start position:0% +again because you're short circu in your + + + align:start position:0% +again because you're short circu in your +device current is flowing through but + + align:start position:0% +device current is flowing through but + + + align:start position:0% +device current is flowing through but +there's no resistor there's no external + + align:start position:0% +there's no resistor there's no external + + + align:start position:0% +there's no resistor there's no external +load there's no power being deposited on + + align:start position:0% +load there's no power being deposited on + + + align:start position:0% +load there's no power being deposited on +external load somewhere between these + + align:start position:0% +external load somewhere between these + + + align:start position:0% +external load somewhere between these +two extreme conditions where there's no + + align:start position:0% +two extreme conditions where there's no + + + align:start position:0% +two extreme conditions where there's no +power flowing through the external + + align:start position:0% +power flowing through the external + + + align:start position:0% +power flowing through the external +circuit you have a maximum power point + + align:start position:0% +circuit you have a maximum power point + + + align:start position:0% +circuit you have a maximum power point +where there is a power being deposited + + align:start position:0% +where there is a power being deposited + + + align:start position:0% +where there is a power being deposited +across your external circuit and a lot + + align:start position:0% +across your external circuit and a lot + + + align:start position:0% +across your external circuit and a lot +of it right that's the maximum power + + align:start position:0% +of it right that's the maximum power + + + align:start position:0% +of it right that's the maximum power +point this is a point at which the solar + + align:start position:0% +point this is a point at which the solar + + + align:start position:0% +point this is a point at which the solar +cell is producing the maximum amount of + + align:start position:0% +cell is producing the maximum amount of + + + align:start position:0% +cell is producing the maximum amount of +power output and to represent that uh + + align:start position:0% +power output and to represent that uh + + + align:start position:0% +power output and to represent that uh +slightly differently what I've done so + + align:start position:0% +slightly differently what I've done so + + + align:start position:0% +slightly differently what I've done so +if I were to take current times voltage + + align:start position:0% +if I were to take current times voltage + + + align:start position:0% +if I were to take current times voltage +right here using fourth quadrant data my + + align:start position:0% +right here using fourth quadrant data my + + + align:start position:0% +right here using fourth quadrant data my +power would be a negative number why + + align:start position:0% +power would be a negative number why + + + align:start position:0% +power would be a negative number why +because vol is positive but current is a + + align:start position:0% +because vol is positive but current is a + + + align:start position:0% +because vol is positive but current is a +negative number right so I multiply a + + align:start position:0% +negative number right so I multiply a + + + align:start position:0% +negative number right so I multiply a +positive and negative number together + + align:start position:0% +positive and negative number together + + + align:start position:0% +positive and negative number together +get a negative number and that just + + align:start position:0% +get a negative number and that just + + + align:start position:0% +get a negative number and that just +sounds weird who talks about power + + align:start position:0% +sounds weird who talks about power + + + align:start position:0% +sounds weird who talks about power +outputs from solar cells being negative + + align:start position:0% +outputs from solar cells being negative + + + align:start position:0% +outputs from solar cells being negative +uh it almost sounds like power is going + + align:start position:0% +uh it almost sounds like power is going + + + align:start position:0% +uh it almost sounds like power is going +into the device so uh this is another + + align:start position:0% +into the device so uh this is another + + + align:start position:0% +into the device so uh this is another +convention that you're going to have to + + align:start position:0% +convention that you're going to have to + + + align:start position:0% +convention that you're going to have to +get used to is looking at the IV curve + + align:start position:0% +get used to is looking at the IV curve + + + align:start position:0% +get used to is looking at the IV curve +in the first quadrant so all we've done + + align:start position:0% +in the first quadrant so all we've done + + + align:start position:0% +in the first quadrant so all we've done +is taken the y- AIS and multiply by + + align:start position:0% +is taken the y- AIS and multiply by + + + align:start position:0% +is taken the y- AIS and multiply by +negative 1 so we flipped it up + + align:start position:0% +negative 1 so we flipped it up + + + align:start position:0% +negative 1 so we flipped it up +right so bear with me here it's it's + + align:start position:0% +right so bear with me here it's it's + + + align:start position:0% +right so bear with me here it's it's +it's a bit tricky to keep all this in + + align:start position:0% +it's a bit tricky to keep all this in + + + align:start position:0% +it's a bit tricky to keep all this in +your Ram but uh here's our short circuit + + align:start position:0% +your Ram but uh here's our short circuit + + + align:start position:0% +your Ram but uh here's our short circuit +current point now here's our open + + align:start position:0% +current point now here's our open + + + align:start position:0% +current point now here's our open +circuit voltage Point our IV curve now + + align:start position:0% +circuit voltage Point our IV curve now + + + align:start position:0% +circuit voltage Point our IV curve now +is pointed down before it was going up + + align:start position:0% +is pointed down before it was going up + + + align:start position:0% +is pointed down before it was going up +because we were in the fourth quadrant + + align:start position:0% +because we were in the fourth quadrant + + + align:start position:0% +because we were in the fourth quadrant +now we flipped essentially just done a + + align:start position:0% +now we flipped essentially just done a + + + align:start position:0% +now we flipped essentially just done a +we we've we've done a flip vertical if + + align:start position:0% +we we've we've done a flip vertical if + + + align:start position:0% +we we've we've done a flip vertical if +you will on our I curve and we have uh + + align:start position:0% +you will on our I curve and we have uh + + + align:start position:0% +you will on our I curve and we have uh +our Uh current increasing here going to + + align:start position:0% +our Uh current increasing here going to + + + align:start position:0% +our Uh current increasing here going to +higher Vias voltages now we can take the + + align:start position:0% +higher Vias voltages now we can take the + + + align:start position:0% +higher Vias voltages now we can take the +product of the voltage and the current + + align:start position:0% +product of the voltage and the current + + + align:start position:0% +product of the voltage and the current +to determine the power and we obtain a + + align:start position:0% +to determine the power and we obtain a + + + align:start position:0% +to determine the power and we obtain a +curve that looks very much like this + + align:start position:0% +curve that looks very much like this + + + align:start position:0% +curve that looks very much like this +blue curve right here that you can see + + align:start position:0% +blue curve right here that you can see + + + align:start position:0% +blue curve right here that you can see +and the maximum power point is truth in + + align:start position:0% +and the maximum power point is truth in + + + align:start position:0% +and the maximum power point is truth in +advertising it's act to maximum power + + align:start position:0% +advertising it's act to maximum power + + + align:start position:0% +advertising it's act to maximum power +it's where this blue curve reaches a + + align:start position:0% +it's where this blue curve reaches a + + + align:start position:0% +it's where this blue curve reaches a +maximum that is the maximum power point + + align:start position:0% +maximum that is the maximum power point + + + align:start position:0% +maximum that is the maximum power point +of the solar cell device that is where + + align:start position:0% +of the solar cell device that is where + + + align:start position:0% +of the solar cell device that is where +the solar cell is outputting the maximum + + align:start position:0% +the solar cell is outputting the maximum + + + align:start position:0% +the solar cell is outputting the maximum +amount of power and so at this maximum + + align:start position:0% +amount of power and so at this maximum + + + align:start position:0% +amount of power and so at this maximum +power point there is a voltage and a + + align:start position:0% +power point there is a voltage and a + + + align:start position:0% +power point there is a voltage and a +current associated with it that you can + + align:start position:0% +current associated with it that you can + + + align:start position:0% +current associated with it that you can +read right off the IV curve and this we + + align:start position:0% +read right off the IV curve and this we + + + align:start position:0% +read right off the IV curve and this we +call JMP or current density at the + + align:start position:0% +call JMP or current density at the + + + align:start position:0% +call JMP or current density at the +maximum power point and V MP which is + + align:start position:0% +maximum power point and V MP which is + + + align:start position:0% +maximum power point and V MP which is +the voltage at the maximum power + + align:start position:0% +the voltage at the maximum power + + + align:start position:0% +the voltage at the maximum power +point so so far we've learned uh + + align:start position:0% +point so so far we've learned uh + + + align:start position:0% +point so so far we've learned uh +essentially four variables here we have + + align:start position:0% +essentially four variables here we have + + + align:start position:0% +essentially four variables here we have +our JSC our VOC and our JMP and our VMP + + align:start position:0% +our JSC our VOC and our JMP and our VMP + + + align:start position:0% +our JSC our VOC and our JMP and our VMP +at that data point right + + align:start position:0% +at that data point right + + + align:start position:0% +at that data point right +there questions since I know you have + + align:start position:0% +there questions since I know you have + + + align:start position:0% +there questions since I know you have +them Ure that the device is working the + + align:start position:0% +them Ure that the device is working the + + + align:start position:0% +them Ure that the device is working the +maximum + + align:start position:0% +maximum + + + align:start position:0% +maximum +PowerPoint uh does an external voltage + + align:start position:0% +PowerPoint uh does an external voltage + + + align:start position:0% +PowerPoint uh does an external voltage +have to be applied to it so to to ensure + + align:start position:0% +have to be applied to it so to to ensure + + + align:start position:0% +have to be applied to it so to to ensure +that the solar cell device is operating + + align:start position:0% +that the solar cell device is operating + + + align:start position:0% +that the solar cell device is operating +right here um a couple of things need to + + align:start position:0% +right here um a couple of things need to + + + align:start position:0% +right here um a couple of things need to +happen you need to have the right + + align:start position:0% +happen you need to have the right + + + align:start position:0% +happen you need to have the right +illumination conditions and and you need + + align:start position:0% +illumination conditions and and you need + + + align:start position:0% +illumination conditions and and you need +to have the right load so the two need + + align:start position:0% +to have the right load so the two need + + + align:start position:0% +to have the right load so the two need +to be matched to each other absolutely + + align:start position:0% +to be matched to each other absolutely + + + align:start position:0% +to be matched to each other absolutely +and that's where some of the Power + + align:start position:0% +and that's where some of the Power + + + align:start position:0% +and that's where some of the Power +Electronics come into play yeah yeah + + align:start position:0% +Electronics come into play yeah yeah + + + align:start position:0% +Electronics come into play yeah yeah +last + + align:start position:0% + + + + align:start position:0% + +problem we assumed that output voltage + + align:start position:0% +problem we assumed that output voltage + + + align:start position:0% +problem we assumed that output voltage +would be B Gap 0.5 Vols yeah is that a + + align:start position:0% +would be B Gap 0.5 Vols yeah is that a + + + align:start position:0% +would be B Gap 0.5 Vols yeah is that a +general safe assumption for aign + + align:start position:0% +general safe assumption for aign + + + align:start position:0% +general safe assumption for aign +solar yeah so it's very interesting + + align:start position:0% +solar yeah so it's very interesting + + + align:start position:0% +solar yeah so it's very interesting +question um regarding the homework + + align:start position:0% +question um regarding the homework + + + align:start position:0% +question um regarding the homework +question I'm going to repeat it so that + + align:start position:0% +question I'm going to repeat it so that + + + align:start position:0% +question I'm going to repeat it so that +the microphone can hear it um the + + align:start position:0% +the microphone can hear it um the + + + align:start position:0% +the microphone can hear it um the +homework uh question the last the last + + align:start position:0% +homework uh question the last the last + + + align:start position:0% +homework uh question the last the last +uh homework there was one question that + + align:start position:0% +uh homework there was one question that + + + align:start position:0% +uh homework there was one question that +inquired uh assume that the voltage at + + align:start position:0% +inquired uh assume that the voltage at + + + align:start position:0% +inquired uh assume that the voltage at +the maximum power point is the band Gap + + align:start position:0% +the maximum power point is the band Gap + + + align:start position:0% +the maximum power point is the band Gap +uh voltage equivalent minus 0.5 volts + + align:start position:0% +uh voltage equivalent minus 0.5 volts + + + align:start position:0% +uh voltage equivalent minus 0.5 volts +and uh the rationale for that assumption + + align:start position:0% +and uh the rationale for that assumption + + + align:start position:0% +and uh the rationale for that assumption +is as follows the open circuit voltage + + align:start position:0% +is as follows the open circuit voltage + + + align:start position:0% +is as follows the open circuit voltage +this point is generally between 0.35 and + + align:start position:0% +this point is generally between 0.35 and + + + align:start position:0% +this point is generally between 0.35 and +0.4 volts minus the band gap or lower + + align:start position:0% +0.4 volts minus the band gap or lower + + + align:start position:0% +0.4 volts minus the band gap or lower +than the bang Gap so you have the bang + + align:start position:0% +than the bang Gap so you have the bang + + + align:start position:0% +than the bang Gap so you have the bang +Gap energy minus 0.4 volts and I can + + align:start position:0% +Gap energy minus 0.4 volts and I can + + + align:start position:0% +Gap energy minus 0.4 volts and I can +show you a very nice little paper that + + align:start position:0% +show you a very nice little paper that + + + align:start position:0% +show you a very nice little paper that +describes why that is essentially has to + + align:start position:0% +describes why that is essentially has to + + + align:start position:0% +describes why that is essentially has to +do in part with the losses inside of the + + align:start position:0% +do in part with the losses inside of the + + + align:start position:0% +do in part with the losses inside of the +solar cell thermodynamic limits of + + align:start position:0% +solar cell thermodynamic limits of + + + align:start position:0% +solar cell thermodynamic limits of +conversion inside of the solar cell + + align:start position:0% +conversion inside of the solar cell + + + align:start position:0% +conversion inside of the solar cell +device then what we've done is we've + + align:start position:0% +device then what we've done is we've + + + align:start position:0% +device then what we've done is we've +done another another additional + + align:start position:0% +done another another additional + + + align:start position:0% +done another another additional +discounting from the vocc to the maximum + + align:start position:0% +discounting from the vocc to the maximum + + + align:start position:0% +discounting from the vocc to the maximum +PowerPoint which we've assumed is around + + align:start position:0% +PowerPoint which we've assumed is around + + + align:start position:0% +PowerPoint which we've assumed is around +0.1 maybe2 volts uh notice the shape of + + align:start position:0% +0.1 maybe2 volts uh notice the shape of + + + align:start position:0% +0.1 maybe2 volts uh notice the shape of +the IV curve right here the maximum + + align:start position:0% +the IV curve right here the maximum + + + align:start position:0% +the IV curve right here the maximum +PowerPoint is interesting because the + + align:start position:0% +PowerPoint is interesting because the + + + align:start position:0% +PowerPoint is interesting because the +voltage at the maximum power point is + + align:start position:0% +voltage at the maximum power point is + + + align:start position:0% +voltage at the maximum power point is +almost the vocc in a good device and the + + align:start position:0% +almost the vocc in a good device and the + + + align:start position:0% +almost the vocc in a good device and the +current at the maximum power point is + + align:start position:0% +current at the maximum power point is + + + align:start position:0% +current at the maximum power point is +almost JSC but not + + align:start position:0% +almost JSC but not + + + align:start position:0% +almost JSC but not +quite right so uh the discounting from + + align:start position:0% +quite right so uh the discounting from + + + align:start position:0% +quite right so uh the discounting from +the vocc to the maximum PowerPoint + + align:start position:0% +the vocc to the maximum PowerPoint + + + align:start position:0% +the vocc to the maximum PowerPoint +voltage is not that much as is the + + align:start position:0% +voltage is not that much as is the + + + align:start position:0% +voltage is not that much as is the +discounting from the short circuit + + align:start position:0% +discounting from the short circuit + + + align:start position:0% +discounting from the short circuit +current to the maximum power point in a + + align:start position:0% +current to the maximum power point in a + + + align:start position:0% +current to the maximum power point in a +good device in a bad device uh this + + align:start position:0% +good device in a bad device uh this + + + align:start position:0% +good device in a bad device uh this +maximum PowerPoint here could be dragged + + align:start position:0% +maximum PowerPoint here could be dragged + + + align:start position:0% +maximum PowerPoint here could be dragged +all the way down here you could have an + + align:start position:0% +all the way down here you could have an + + + align:start position:0% +all the way down here you could have an +IV curve that looked something more like + + align:start position:0% +IV curve that looked something more like + + + align:start position:0% +IV curve that looked something more like +this instead almost like a resistor at + + align:start position:0% +this instead almost like a resistor at + + + align:start position:0% +this instead almost like a resistor at +which point um the maximum power output + + align:start position:0% +which point um the maximum power output + + + align:start position:0% +which point um the maximum power output +would be a lot less a lot less than + + align:start position:0% +would be a lot less a lot less than + + + align:start position:0% +would be a lot less a lot less than +what's shown here in the blue + + align:start position:0% + + + + align:start position:0% + +curve cool all right so let's uh + + align:start position:0% +curve cool all right so let's uh + + + align:start position:0% +curve cool all right so let's uh +continue moving on um the efficiency of + + align:start position:0% +continue moving on um the efficiency of + + + align:start position:0% +continue moving on um the efficiency of +the solar cell Ada uh this Greek letter + + align:start position:0% +the solar cell Ada uh this Greek letter + + + align:start position:0% +the solar cell Ada uh this Greek letter +Ada is our power out versus Power in our + + align:start position:0% +Ada is our power out versus Power in our + + + align:start position:0% +Ada is our power out versus Power in our +power in is the illumination intensity + + align:start position:0% +power in is the illumination intensity + + + align:start position:0% +power in is the illumination intensity +given in units of watts per meter squar + + align:start position:0% +given in units of watts per meter squar + + + align:start position:0% +given in units of watts per meter squar +so we calculated this in our very first + + align:start position:0% +so we calculated this in our very first + + + align:start position:0% +so we calculated this in our very first +homework assignment and realized that + + align:start position:0% +homework assignment and realized that + + + align:start position:0% +homework assignment and realized that +the am 1.5 spectrum is around 1,000 + + align:start position:0% +the am 1.5 spectrum is around 1,000 + + + align:start position:0% +the am 1.5 spectrum is around 1,000 +watts per met squ so that's our input + + align:start position:0% +watts per met squ so that's our input + + + align:start position:0% +watts per met squ so that's our input +power right + + align:start position:0% + + + + align:start position:0% + +here our output power is the voltage at + + align:start position:0% +here our output power is the voltage at + + + align:start position:0% +here our output power is the voltage at +the maximum power point times whoopsie + + align:start position:0% +the maximum power point times whoopsie + + + align:start position:0% +the maximum power point times whoopsie +times the current at the maximum power + + align:start position:0% +times the current at the maximum power + + + align:start position:0% +times the current at the maximum power +point not the current density the + + align:start position:0% +point not the current density the + + + align:start position:0% +point not the current density the +current at the maximum power point so + + align:start position:0% +current at the maximum power point so + + + align:start position:0% +current at the maximum power point so +take this current density and multiply + + align:start position:0% +take this current density and multiply + + + align:start position:0% +take this current density and multiply +by area that's effectively the the units + + align:start position:0% +by area that's effectively the the units + + + align:start position:0% +by area that's effectively the the units +work out better that way um so it would + + align:start position:0% +work out better that way um so it would + + + align:start position:0% +work out better that way um so it would +be either V * I at the maximum power + + align:start position:0% +be either V * I at the maximum power + + + align:start position:0% +be either V * I at the maximum power +point or V * J * the area at the area of + + align:start position:0% +point or V * J * the area at the area of + + + align:start position:0% +point or V * J * the area at the area of +the device the area of the solar cell at + + align:start position:0% +the device the area of the solar cell at + + + align:start position:0% +the device the area of the solar cell at +the maximum power point and that's the + + align:start position:0% +the maximum power point and that's the + + + align:start position:0% +the maximum power point and that's the +total power + + align:start position:0% +total power + + + align:start position:0% +total power +out actually yeah yeah so um as long as + + align:start position:0% +out actually yeah yeah so um as long as + + + align:start position:0% +out actually yeah yeah so um as long as +the units are are in units of watts per + + align:start position:0% +the units are are in units of watts per + + + align:start position:0% +the units are are in units of watts per +meter squared yeah down here if this is + + align:start position:0% +meter squared yeah down here if this is + + + align:start position:0% +meter squared yeah down here if this is +not total Watts but watts per meter + + align:start position:0% +not total Watts but watts per meter + + + align:start position:0% +not total Watts but watts per meter +squar you could still use current + + align:start position:0% +squar you could still use current + + + align:start position:0% +squar you could still use current +density um that would those units would + + align:start position:0% +density um that would those units would + + + align:start position:0% +density um that would those units would +still work out so be be very careful + + align:start position:0% +still work out so be be very careful + + + align:start position:0% +still work out so be be very careful +whether you use total uh Power in or + + align:start position:0% +whether you use total uh Power in or + + + align:start position:0% +whether you use total uh Power in or +normalized by unit area power right just + + align:start position:0% +normalized by unit area power right just + + + align:start position:0% +normalized by unit area power right just +keep track of your units don't do like + + align:start position:0% +keep track of your units don't do like + + + align:start position:0% +keep track of your units don't do like +the + + align:start position:0% +the + + + align:start position:0% +the +professor um okay so we have efficiency + + align:start position:0% +professor um okay so we have efficiency + + + align:start position:0% +professor um okay so we have efficiency +here as power out versus Power in the + + align:start position:0% +here as power out versus Power in the + + + align:start position:0% +here as power out versus Power in the +power out being the maximum PowerPoint + + align:start position:0% +power out being the maximum PowerPoint + + + align:start position:0% +power out being the maximum PowerPoint +power and the power in being the + + align:start position:0% +power and the power in being the + + + align:start position:0% +power and the power in being the +illumination from the Sun now we're + + align:start position:0% +illumination from the Sun now we're + + + align:start position:0% +illumination from the Sun now we're +really talking this is starting to get + + align:start position:0% +really talking this is starting to get + + + align:start position:0% +really talking this is starting to get +interesting because it's beginning to + + align:start position:0% +interesting because it's beginning to + + + align:start position:0% +interesting because it's beginning to +click pieces from lecture number two + + align:start position:0% +click pieces from lecture number two + + + align:start position:0% +click pieces from lecture number two +coming together with what we're seeing + + align:start position:0% +coming together with what we're seeing + + + align:start position:0% +coming together with what we're seeing +now so this is a solar cell output power + + align:start position:0% +now so this is a solar cell output power + + + align:start position:0% +now so this is a solar cell output power +at the maximum power point and sunlight + + align:start position:0% +at the maximum power point and sunlight + + + align:start position:0% +at the maximum power point and sunlight +coming in okay so what I'm going to do + + align:start position:0% +coming in okay so what I'm going to do + + + align:start position:0% +coming in okay so what I'm going to do +next is um I'm going to take this + + align:start position:0% +next is um I'm going to take this + + + align:start position:0% +next is um I'm going to take this +maximum PowerPoint I'm going to draw a + + align:start position:0% +maximum PowerPoint I'm going to draw a + + + align:start position:0% +maximum PowerPoint I'm going to draw a +box that ends that starts at the origin + + align:start position:0% +box that ends that starts at the origin + + + align:start position:0% +box that ends that starts at the origin +here and the other uh the other the + + align:start position:0% +here and the other uh the other the + + + align:start position:0% +here and the other uh the other the +opposite uh the kitty corner corner of + + align:start position:0% +opposite uh the kitty corner corner of + + + align:start position:0% +opposite uh the kitty corner corner of +my box is going to end at the maximum + + align:start position:0% +my box is going to end at the maximum + + + align:start position:0% +my box is going to end at the maximum +PowerPoint so I'll have some rectal + + align:start position:0% +PowerPoint so I'll have some rectal + + + align:start position:0% +PowerPoint so I'll have some rectal +linear shape that will comprise the + + align:start position:0% +linear shape that will comprise the + + + align:start position:0% +linear shape that will comprise the +maximum PowerPoint and0 0 the origin as + + align:start position:0% +maximum PowerPoint and0 0 the origin as + + + align:start position:0% +maximum PowerPoint and0 0 the origin as +two of its uh corners and that box looks + + align:start position:0% +two of its uh corners and that box looks + + + align:start position:0% +two of its uh corners and that box looks +like this blue one right here the area + + align:start position:0% +like this blue one right here the area + + + align:start position:0% +like this blue one right here the area +of that box is JMP time + + align:start position:0% +of that box is JMP time + + + align:start position:0% +of that box is JMP time +VMP okay and notice I have another box + + align:start position:0% +VMP okay and notice I have another box + + + align:start position:0% +VMP okay and notice I have another box +around here I have this uh clear box + + align:start position:0% +around here I have this uh clear box + + + align:start position:0% +around here I have this uh clear box +that starts uh at the VOC uh point and + + align:start position:0% +that starts uh at the VOC uh point and + + + align:start position:0% +that starts uh at the VOC uh point and +the JSC point and now I have have two + + align:start position:0% +the JSC point and now I have have two + + + align:start position:0% +the JSC point and now I have have two +rectilinear shapes this blue one and the + + align:start position:0% +rectilinear shapes this blue one and the + + + align:start position:0% +rectilinear shapes this blue one and the +clear one right here the bigger one the + + align:start position:0% +clear one right here the bigger one the + + + align:start position:0% +clear one right here the bigger one the +bigger one has an area of JC time + + align:start position:0% +bigger one has an area of JC time + + + align:start position:0% +bigger one has an area of JC time +vo and I'm going to define a parameter + + align:start position:0% +vo and I'm going to define a parameter + + + align:start position:0% +vo and I'm going to define a parameter +called Phill factor which will be the + + align:start position:0% +called Phill factor which will be the + + + align:start position:0% +called Phill factor which will be the +ratio of these two areas the ratio of + + align:start position:0% +ratio of these two areas the ratio of + + + align:start position:0% +ratio of these two areas the ratio of +those two boxes the VMP * JMP divided by + + align:start position:0% +those two boxes the VMP * JMP divided by + + + align:start position:0% +those two boxes the VMP * JMP divided by +the VOC JSC if this is one which is + + align:start position:0% +the VOC JSC if this is one which is + + + align:start position:0% +the VOC JSC if this is one which is +virtually impossible to do but if this + + align:start position:0% +virtually impossible to do but if this + + + align:start position:0% +virtually impossible to do but if this +were one it would mean that these two + + align:start position:0% +were one it would mean that these two + + + align:start position:0% +were one it would mean that these two +boxes were the same size and the current + + align:start position:0% +boxes were the same size and the current + + + align:start position:0% +boxes were the same size and the current +and voltage at the maximum power points + + align:start position:0% +and voltage at the maximum power points + + + align:start position:0% +and voltage at the maximum power points +would be the current and voltage uh + + align:start position:0% +would be the current and voltage uh + + + align:start position:0% +would be the current and voltage uh +under short circuit and open circuit + + align:start position:0% +under short circuit and open circuit + + + align:start position:0% +under short circuit and open circuit +conditions respectively in real life the + + align:start position:0% +conditions respectively in real life the + + + align:start position:0% +conditions respectively in real life the +uh uh this blue box is smaller than the + + align:start position:0% +uh uh this blue box is smaller than the + + + align:start position:0% +uh uh this blue box is smaller than the +this clear box right over here and so uh + + align:start position:0% +this clear box right over here and so uh + + + align:start position:0% +this clear box right over here and so uh +the JMP VMP product is less than the JSC + + align:start position:0% +the JMP VMP product is less than the JSC + + + align:start position:0% +the JMP VMP product is less than the JSC +vocc product and by consequence as well + + align:start position:0% +vocc product and by consequence as well + + + align:start position:0% +vocc product and by consequence as well +the JMP is less than JSC v&p is less + + align:start position:0% +the JMP is less than JSC v&p is less + + + align:start position:0% +the JMP is less than JSC v&p is less +than uh V so the ratio of the two boxes + + align:start position:0% +than uh V so the ratio of the two boxes + + + align:start position:0% +than uh V so the ratio of the two boxes +is defined as the fill Factor The Fill + + align:start position:0% +is defined as the fill Factor The Fill + + + align:start position:0% +is defined as the fill Factor The Fill +Factor indicates the quality of your + + align:start position:0% +Factor indicates the quality of your + + + align:start position:0% +Factor indicates the quality of your +diode if your fill factor is very poor + + align:start position:0% +diode if your fill factor is very poor + + + align:start position:0% +diode if your fill factor is very poor +that means that that sun right over + + align:start position:0% +that means that that sun right over + + + align:start position:0% +that means that that sun right over +there denotes the maximum power point is + + align:start position:0% +there denotes the maximum power point is + + + align:start position:0% +there denotes the maximum power point is +being dragged toward the origin that + + align:start position:0% +being dragged toward the origin that + + + align:start position:0% +being dragged toward the origin that +means that the area of this blue box is + + align:start position:0% +means that the area of this blue box is + + + align:start position:0% +means that the area of this blue box is +growing smaller relative to the area of + + align:start position:0% +growing smaller relative to the area of + + + align:start position:0% +growing smaller relative to the area of +this clear box The Fill factor is going + + align:start position:0% +this clear box The Fill factor is going + + + align:start position:0% +this clear box The Fill factor is going +down that means you're filling less of + + align:start position:0% +down that means you're filling less of + + + align:start position:0% +down that means you're filling less of +this maximum square box function defined + + align:start position:0% +this maximum square box function defined + + + align:start position:0% +this maximum square box function defined +by vjc + + align:start position:0% + + + + align:start position:0% + +okay so uh we have defined efficiency as + + align:start position:0% +okay so uh we have defined efficiency as + + + align:start position:0% +okay so uh we have defined efficiency as +uh Power out divided by power in power + + align:start position:0% +uh Power out divided by power in power + + + align:start position:0% +uh Power out divided by power in power +out being the current voltage product at + + align:start position:0% +out being the current voltage product at + + + align:start position:0% +out being the current voltage product at +the maximum power point divided by the + + align:start position:0% +the maximum power point divided by the + + + align:start position:0% +the maximum power point divided by the +solar instulation fill Factor being + + align:start position:0% +solar instulation fill Factor being + + + align:start position:0% +solar instulation fill Factor being +defined as the U ratio of VMP imp + + align:start position:0% +defined as the U ratio of VMP imp + + + align:start position:0% +defined as the U ratio of VMP imp +product divided by VOC uh ISC product uh + + align:start position:0% +product divided by VOC uh ISC product uh + + + align:start position:0% +product divided by VOC uh ISC product uh +notice that here I've written this in + + align:start position:0% +notice that here I've written this in + + + align:start position:0% +notice that here I've written this in +terms of total current here in terms of + + align:start position:0% +terms of total current here in terms of + + + align:start position:0% +terms of total current here in terms of +current density uh the area is + + align:start position:0% +current density uh the area is + + + align:start position:0% +current density uh the area is +essentially just cancel out because you + + align:start position:0% +essentially just cancel out because you + + + align:start position:0% +essentially just cancel out because you +have an area in the numerator and + + align:start position:0% +have an area in the numerator and + + + align:start position:0% +have an area in the numerator and +denominator they cancel these ratios + + align:start position:0% +denominator they cancel these ratios + + + align:start position:0% +denominator they cancel these ratios +should be + + align:start position:0% +should be + + + align:start position:0% +should be +identical thus we obtain an expression + + align:start position:0% +identical thus we obtain an expression + + + align:start position:0% +identical thus we obtain an expression +for the efficiency in terms of fill + + align:start position:0% +for the efficiency in terms of fill + + + align:start position:0% +for the efficiency in terms of fill +Factor vo and ISC simply by using this + + align:start position:0% +Factor vo and ISC simply by using this + + + align:start position:0% +Factor vo and ISC simply by using this +fill factor definition right here what + + align:start position:0% +fill factor definition right here what + + + align:start position:0% +fill factor definition right here what +I've done is I've multiplied this side + + align:start position:0% +I've done is I've multiplied this side + + + align:start position:0% +I've done is I've multiplied this side +of the equation let's just focus right + + align:start position:0% +of the equation let's just focus right + + + align:start position:0% +of the equation let's just focus right +here where we have fil Factor equals VMP + + align:start position:0% +here where we have fil Factor equals VMP + + + align:start position:0% +here where we have fil Factor equals VMP +* / VC I I've moved the uh denominator + + align:start position:0% +* / VC I I've moved the uh denominator + + + align:start position:0% +* / VC I I've moved the uh denominator +up to the side over here multiplied it + + align:start position:0% +up to the side over here multiplied it + + + align:start position:0% +up to the side over here multiplied it +by fi factor and that's my + + align:start position:0% +by fi factor and that's my + + + align:start position:0% +by fi factor and that's my +now I go back to that top equation I say + + align:start position:0% +now I go back to that top equation I say + + + align:start position:0% +now I go back to that top equation I say +my VMP is now going to be substituted by + + align:start position:0% +my VMP is now going to be substituted by + + + align:start position:0% +my VMP is now going to be substituted by +a fill Factor time VOC * ISC and that's + + align:start position:0% +a fill Factor time VOC * ISC and that's + + + align:start position:0% +a fill Factor time VOC * ISC and that's +how I get to this equation right here + + align:start position:0% +how I get to this equation right here + + + align:start position:0% +how I get to this equation right here +why why do I go through the effort of + + align:start position:0% +why why do I go through the effort of + + + align:start position:0% +why why do I go through the effort of +this little numerical manipulation I do + + align:start position:0% +this little numerical manipulation I do + + + align:start position:0% +this little numerical manipulation I do +it because these parameters right here + + align:start position:0% +it because these parameters right here + + + align:start position:0% +it because these parameters right here +are fairly easy to measure using the + + align:start position:0% +are fairly easy to measure using the + + + align:start position:0% +are fairly easy to measure using the +solar simulator that you just put + + align:start position:0% +solar simulator that you just put + + + align:start position:0% +solar simulator that you just put +together right so I can measure the + + align:start position:0% +together right so I can measure the + + + align:start position:0% +together right so I can measure the +point at which uh my voltage is at open + + align:start position:0% +point at which uh my voltage is at open + + + align:start position:0% +point at which uh my voltage is at open +circuit condition I can measure the + + align:start position:0% +circuit condition I can measure the + + + align:start position:0% +circuit condition I can measure the +current uh at Short Circuit condition + + align:start position:0% +current uh at Short Circuit condition + + + align:start position:0% +current uh at Short Circuit condition +and simply by taking the ratio of those + + align:start position:0% +and simply by taking the ratio of those + + + align:start position:0% +and simply by taking the ratio of those +boxes I can determine what my fill + + align:start position:0% +boxes I can determine what my fill + + + align:start position:0% +boxes I can determine what my fill +factor is as well and these break down + + align:start position:0% +factor is as well and these break down + + + align:start position:0% +factor is as well and these break down +roughly into uh uh the the the the + + align:start position:0% +roughly into uh uh the the the the + + + align:start position:0% +roughly into uh uh the the the the +current is going to be a function + + align:start position:0% +current is going to be a function + + + align:start position:0% +current is going to be a function +roughly I again them really painting + + align:start position:0% +roughly I again them really painting + + + align:start position:0% +roughly I again them really painting +broad brush Strokes here the current is + + align:start position:0% +broad brush Strokes here the current is + + + align:start position:0% +broad brush Strokes here the current is +going to be roughly a function of + + align:start position:0% +going to be roughly a function of + + + align:start position:0% +going to be roughly a function of +Illumination condition and bulk material + + align:start position:0% +Illumination condition and bulk material + + + align:start position:0% +Illumination condition and bulk material +quality the VOC will be roughly a + + align:start position:0% +quality the VOC will be roughly a + + + align:start position:0% +quality the VOC will be roughly a +function of the interface the diode + + align:start position:0% +function of the interface the diode + + + align:start position:0% +function of the interface the diode +characteristics and the fill factor is + + align:start position:0% +characteristics and the fill factor is + + + align:start position:0% +characteristics and the fill factor is +going to be a function of the interface + + align:start position:0% +going to be a function of the interface + + + align:start position:0% +going to be a function of the interface +di characteristics but also of the + + align:start position:0% +di characteristics but also of the + + + align:start position:0% +di characteristics but also of the +resistances within the device and so + + align:start position:0% +resistances within the device and so + + + align:start position:0% +resistances within the device and so +from an engineering point of view we + + align:start position:0% +from an engineering point of view we + + + align:start position:0% +from an engineering point of view we +break the solar cell output down into + + align:start position:0% +break the solar cell output down into + + + align:start position:0% +break the solar cell output down into +these three parameters so that we can + + align:start position:0% +these three parameters so that we can + + + align:start position:0% +these three parameters so that we can +better understand uh what's going wrong + + align:start position:0% +better understand uh what's going wrong + + + align:start position:0% +better understand uh what's going wrong +with our solar cell if we have + + align:start position:0% +with our solar cell if we have + + + align:start position:0% +with our solar cell if we have +everything lumped in terms of VMP it + + align:start position:0% +everything lumped in terms of VMP it + + + align:start position:0% +everything lumped in terms of VMP it +becomes a little bit more obscure to + + align:start position:0% +becomes a little bit more obscure to + + + align:start position:0% +becomes a little bit more obscure to +figure out what exactly is going wrong + + align:start position:0% +figure out what exactly is going wrong + + + align:start position:0% +figure out what exactly is going wrong +with our solar cell device Ashley how do + + align:start position:0% +with our solar cell device Ashley how do + + + align:start position:0% +with our solar cell device Ashley how do +you I guess the fill Factor also an + + align:start position:0% +you I guess the fill Factor also an + + + align:start position:0% +you I guess the fill Factor also an +easily measurable parameter so the fill + + align:start position:0% +easily measurable parameter so the fill + + + align:start position:0% +easily measurable parameter so the fill +Factor you would measure essentially by + + align:start position:0% +Factor you would measure essentially by + + + align:start position:0% +Factor you would measure essentially by +uh doing the little analysis we just did + + align:start position:0% +uh doing the little analysis we just did + + + align:start position:0% +uh doing the little analysis we just did +right here yeah exactly so you'd have to + + align:start position:0% +right here yeah exactly so you'd have to + + + align:start position:0% +right here yeah exactly so you'd have to +do a voltage current sweep + + align:start position:0% + + + + align:start position:0% + +mhm coolness okay so we have um an + + align:start position:0% +mhm coolness okay so we have um an + + + align:start position:0% +mhm coolness okay so we have um an +expression for efficiency in terms of + + align:start position:0% +expression for efficiency in terms of + + + align:start position:0% +expression for efficiency in terms of +fill Factor VOC ISC and uh our incoming + + align:start position:0% +fill Factor VOC ISC and uh our incoming + + + align:start position:0% +fill Factor VOC ISC and uh our incoming +uh Power so power out this right here + + align:start position:0% +uh Power so power out this right here + + + align:start position:0% +uh Power so power out this right here +again is power out divid by power + + align:start position:0% +again is power out divid by power + + + align:start position:0% +again is power out divid by power +in why does efficiency matter why why do + + align:start position:0% +in why does efficiency matter why why do + + + align:start position:0% +in why does efficiency matter why why do +we why do we care so much about + + align:start position:0% +we why do we care so much about + + + align:start position:0% +we why do we care so much about +efficiency well um the conversion + + align:start position:0% +efficiency well um the conversion + + + align:start position:0% +efficiency well um the conversion +efficiency determines the area of solar + + align:start position:0% +efficiency determines the area of solar + + + align:start position:0% +efficiency determines the area of solar +cells needed to produce a certain Peak + + align:start position:0% +cells needed to produce a certain Peak + + + align:start position:0% +cells needed to produce a certain Peak +power or to think of it differently the + + align:start position:0% +power or to think of it differently the + + + align:start position:0% +power or to think of it differently the +area of solar panels that is necessary + + align:start position:0% +area of solar panels that is necessary + + + align:start position:0% +area of solar panels that is necessary +to produce a certain energy per unit + + align:start position:0% +to produce a certain energy per unit + + + align:start position:0% +to produce a certain energy per unit +time and uh many cost scale with area + + align:start position:0% +time and uh many cost scale with area + + + align:start position:0% +time and uh many cost scale with area +you have glass encapsulant the absorber + + align:start position:0% +you have glass encapsulant the absorber + + + align:start position:0% +you have glass encapsulant the absorber +materials within the solar cell devices + + align:start position:0% +materials within the solar cell devices + + + align:start position:0% +materials within the solar cell devices +themselves the metals that are used to + + align:start position:0% +themselves the metals that are used to + + + align:start position:0% +themselves the metals that are used to +make contacts uh the labor that's used + + align:start position:0% +make contacts uh the labor that's used + + + align:start position:0% +make contacts uh the labor that's used +to install the panels if you have larger + + align:start position:0% +to install the panels if you have larger + + + align:start position:0% +to install the panels if you have larger +panel area you need more labor to + + align:start position:0% +panel area you need more labor to + + + align:start position:0% +panel area you need more labor to +install it the aluminum and rack and + + align:start position:0% +install it the aluminum and rack and + + + align:start position:0% +install it the aluminum and rack and +framing materials that go into uh + + align:start position:0% +framing materials that go into uh + + + align:start position:0% +framing materials that go into uh +holding the panels up in the field uh + + align:start position:0% +holding the panels up in the field uh + + + align:start position:0% +holding the panels up in the field uh +either on a roof or out in the field so + + align:start position:0% +either on a roof or out in the field so + + + align:start position:0% +either on a roof or out in the field so +um efficiency affects pretty much + + align:start position:0% +um efficiency affects pretty much + + + align:start position:0% +um efficiency affects pretty much +everything but the inverter and possibly + + align:start position:0% +everything but the inverter and possibly + + + align:start position:0% +everything but the inverter and possibly +some of the soft costs of the project + + align:start position:0% +some of the soft costs of the project + + + align:start position:0% +some of the soft costs of the project +that includes the architect and uh the + + align:start position:0% +that includes the architect and uh the + + + align:start position:0% +that includes the architect and uh the +people who you pay to handle the money + + align:start position:0% +people who you pay to handle the money + + + align:start position:0% +people who you pay to handle the money +um financing so uh the lawyers perhaps + + align:start position:0% +um financing so uh the lawyers perhaps + + + align:start position:0% +um financing so uh the lawyers perhaps +so pretty much all of uh all of the real + + align:start position:0% +so pretty much all of uh all of the real + + + align:start position:0% +so pretty much all of uh all of the real +material and labor costs are scaling + + align:start position:0% +material and labor costs are scaling + + + align:start position:0% +material and labor costs are scaling +with area uh and so efficiency + + align:start position:0% +with area uh and so efficiency + + + align:start position:0% +with area uh and so efficiency +determines that to a large degree and + + align:start position:0% +determines that to a large degree and + + + align:start position:0% +determines that to a large degree and +hence it's a highly leveraged way to the + + align:start position:0% +hence it's a highly leveraged way to the + + + align:start position:0% +hence it's a highly leveraged way to the +cost of solar energy if you do a + + align:start position:0% +cost of solar energy if you do a + + + align:start position:0% +cost of solar energy if you do a +sensitivity analysis which you will do + + align:start position:0% +sensitivity analysis which you will do + + + align:start position:0% +sensitivity analysis which you will do +in the second and third parts of the + + align:start position:0% +in the second and third parts of the + + + align:start position:0% +in the second and third parts of the +class and look at the cost of solar and + + align:start position:0% +class and look at the cost of solar and + + + align:start position:0% +class and look at the cost of solar and +how it scales with efficiency you'll see + + align:start position:0% +how it scales with efficiency you'll see + + + align:start position:0% +how it scales with efficiency you'll see +that efficiency is one of the + + align:start position:0% +that efficiency is one of the + + + align:start position:0% +that efficiency is one of the +determining factors for cost in a solar + + align:start position:0% +determining factors for cost in a solar + + + align:start position:0% +determining factors for cost in a solar +cell device and that's why we focus on + + align:start position:0% +cell device and that's why we focus on + + + align:start position:0% +cell device and that's why we focus on +it a lot to put into perspective if the + + align:start position:0% +it a lot to put into perspective if the + + + align:start position:0% +it a lot to put into perspective if the +efficiency up there is determined by the + + align:start position:0% +efficiency up there is determined by the + + + align:start position:0% +efficiency up there is determined by the +output power versus the input power if + + align:start position:0% +output power versus the input power if + + + align:start position:0% +output power versus the input power if +we had 100% conversion uh efficiency + + align:start position:0% +we had 100% conversion uh efficiency + + + align:start position:0% +we had 100% conversion uh efficiency +which is impossible to achieve + + align:start position:0% +which is impossible to achieve + + + align:start position:0% +which is impossible to achieve +thermodynamically impossible to achieve + + align:start position:0% +thermodynamically impossible to achieve + + + align:start position:0% +thermodynamically impossible to achieve +we would produce a certain amount of + + align:start position:0% +we would produce a certain amount of + + + align:start position:0% +we would produce a certain amount of +energy per unit time or certain amount + + align:start position:0% +energy per unit time or certain amount + + + align:start position:0% +energy per unit time or certain amount +of peak power with this panel right + + align:start position:0% +of peak power with this panel right + + + align:start position:0% +of peak power with this panel right +there say that's the size of our field + + align:start position:0% +there say that's the size of our field + + + align:start position:0% +there say that's the size of our field +installation if we had a 33% efficiency + + align:start position:0% +installation if we had a 33% efficiency + + + align:start position:0% +installation if we had a 33% efficiency +cell which is closer to space grade + + align:start position:0% +cell which is closer to space grade + + + align:start position:0% +cell which is closer to space grade +solar cells we'd need three times that + + align:start position:0% +solar cells we'd need three times that + + + align:start position:0% +solar cells we'd need three times that +area so three times the encapsulant + + align:start position:0% +area so three times the encapsulant + + + align:start position:0% +area so three times the encapsulant +three times the glass three times the + + align:start position:0% +three times the glass three times the + + + align:start position:0% +three times the glass three times the +labor to install it and if we had a + + align:start position:0% +labor to install it and if we had a + + + align:start position:0% +labor to install it and if we had a +20% efficiency say uh high-end but but + + align:start position:0% +20% efficiency say uh high-end but but + + + align:start position:0% +20% efficiency say uh high-end but but +still uh commercial uh solar module not + + align:start position:0% +still uh commercial uh solar module not + + + align:start position:0% +still uh commercial uh solar module not +something you'd need to get from NASA + + align:start position:0% +something you'd need to get from NASA + + + align:start position:0% +something you'd need to get from NASA +but something that you could uh buy uh + + align:start position:0% +but something that you could uh buy uh + + + align:start position:0% +but something that you could uh buy uh +from a a supplier you would need five + + align:start position:0% +from a a supplier you would need five + + + align:start position:0% +from a a supplier you would need five +times that area whereas if you had a 10% + + align:start position:0% +times that area whereas if you had a 10% + + + align:start position:0% +times that area whereas if you had a 10% +efficiency module which is more + + align:start position:0% +efficiency module which is more + + + align:start position:0% +efficiency module which is more +approaching the area of some relatively + + align:start position:0% +approaching the area of some relatively + + + align:start position:0% +approaching the area of some relatively +inexpensive uh solar cells you would + + align:start position:0% +inexpensive uh solar cells you would + + + align:start position:0% +inexpensive uh solar cells you would +need 10 times that area so if you're + + align:start position:0% +need 10 times that area so if you're + + + align:start position:0% +need 10 times that area so if you're +doing a cost analysis this is why + + align:start position:0% +doing a cost analysis this is why + + + align:start position:0% +doing a cost analysis this is why +efficiency matters it might still be + + align:start position:0% +efficiency matters it might still be + + + align:start position:0% +efficiency matters it might still be +cheaper to use this instead of to use + + align:start position:0% +cheaper to use this instead of to use + + + align:start position:0% +cheaper to use this instead of to use +this over here might very well be more + + align:start position:0% +this over here might very well be more + + + align:start position:0% +this over here might very well be more +expensive when you do the math and + + align:start position:0% +expensive when you do the math and + + + align:start position:0% +expensive when you do the math and +figure out how much it cost to deposit + + align:start position:0% +figure out how much it cost to deposit + + + align:start position:0% +figure out how much it cost to deposit +those materials with a very low food + + align:start position:0% +those materials with a very low food + + + align:start position:0% +those materials with a very low food +foot deposition process and very high + + align:start position:0% +foot deposition process and very high + + + align:start position:0% +foot deposition process and very high +cost it might still be but it might not + + align:start position:0% +cost it might still be but it might not + + + align:start position:0% +cost it might still be but it might not +the material cost might end up whopping + + align:start position:0% +the material cost might end up whopping + + + align:start position:0% +the material cost might end up whopping +you and so a simple equation that + + align:start position:0% +you and so a simple equation that + + + align:start position:0% +you and so a simple equation that +calculates all these parameters in the + + align:start position:0% +calculates all these parameters in the + + + align:start position:0% +calculates all these parameters in the +material costs the module efficiency uh + + align:start position:0% +material costs the module efficiency uh + + + align:start position:0% +material costs the module efficiency uh +essentially the material and wafer costs + + align:start position:0% +essentially the material and wafer costs + + + align:start position:0% +essentially the material and wafer costs +are being calculated in dollars per + + align:start position:0% +are being calculated in dollars per + + + align:start position:0% +are being calculated in dollars per +meter squared they're saying how many + + align:start position:0% +meter squared they're saying how many + + + align:start position:0% +meter squared they're saying how many +dollars go into producing a meter + + align:start position:0% +dollars go into producing a meter + + + align:start position:0% +dollars go into producing a meter +squared of this material and the + + align:start position:0% +squared of this material and the + + + align:start position:0% +squared of this material and the +efficiency is over here and this is just + + align:start position:0% +efficiency is over here and this is just + + + align:start position:0% +efficiency is over here and this is just +a very simple uh uh back of the envelope + + align:start position:0% +a very simple uh uh back of the envelope + + + align:start position:0% +a very simple uh uh back of the envelope +calculation type of way of of of + + align:start position:0% +calculation type of way of of of + + + align:start position:0% +calculation type of way of of of +estimating the cost of a solar system so + + align:start position:0% +estimating the cost of a solar system so + + + align:start position:0% +estimating the cost of a solar system so +if you say okay I'm I'm willing to pay + + align:start position:0% +if you say okay I'm I'm willing to pay + + + align:start position:0% +if you say okay I'm I'm willing to pay +uh more for a higher efficiency cell + + align:start position:0% +uh more for a higher efficiency cell + + + align:start position:0% +uh more for a higher efficiency cell +because I'm using less area uh you can + + align:start position:0% +because I'm using less area uh you can + + + align:start position:0% +because I'm using less area uh you can +use this type of calculation uh to get + + align:start position:0% +use this type of calculation uh to get + + + align:start position:0% +use this type of calculation uh to get +to the the answer quickly it's not a + + align:start position:0% +to the the answer quickly it's not a + + + align:start position:0% +to the the answer quickly it's not a +levelized cost of electricity analysis + + align:start position:0% +levelized cost of electricity analysis + + + align:start position:0% +levelized cost of electricity analysis +it's not using discounted Capital flows + + align:start position:0% +it's not using discounted Capital flows + + + align:start position:0% +it's not using discounted Capital flows +and so forth which we'll get to later on + + align:start position:0% +and so forth which we'll get to later on + + + align:start position:0% +and so forth which we'll get to later on +in class this is a really backof the + + align:start position:0% +in class this is a really backof the + + + align:start position:0% +in class this is a really backof the +envelope engineering approach to + + align:start position:0% +envelope engineering approach to + + + align:start position:0% +envelope engineering approach to +estimating cost of a solar + + align:start position:0% +estimating cost of a solar + + + align:start position:0% +estimating cost of a solar +system um so I think this is a great + + align:start position:0% +system um so I think this is a great + + + align:start position:0% +system um so I think this is a great +place to stop uh and if anybody has a + + align:start position:0% +place to stop uh and if anybody has a + + + align:start position:0% +place to stop uh and if anybody has a +pitch concerning their project ideas + + align:start position:0% +pitch concerning their project ideas + + + align:start position:0% +pitch concerning their project ideas +class project ideas I'd like to invite + + align:start position:0% +class project ideas I'd like to invite + + + align:start position:0% +class project ideas I'd like to invite +them to the front now um the class + + align:start position:0% +them to the front now um the class + + + align:start position:0% +them to the front now um the class +project mind you is really the Capstone + + align:start position:0% +project mind you is really the Capstone + + + align:start position:0% +project mind you is really the Capstone +of this class 266 267 so if you have an + + align:start position:0% +of this class 266 267 so if you have an + + + align:start position:0% +of this class 266 267 so if you have an +idea a fun idea for a class project I'd + + align:start position:0% +idea a fun idea for a class project I'd + + + align:start position:0% +idea a fun idea for a class project I'd +invite you to give a pitch up here at + + align:start position:0% +invite you to give a pitch up here at + + + align:start position:0% +invite you to give a pitch up here at +the front of class or you're welcome to + + align:start position:0% +the front of class or you're welcome to + + + align:start position:0% +the front of class or you're welcome to +uh send on an email to the class ler \ No newline at end of file diff --git a/AfQxyVuLeCs.txt b/AfQxyVuLeCs.txt new file mode 100644 index 0000000000000000000000000000000000000000..880fa419eba32dae27cd4217c14914993f0c1cf7 --- /dev/null +++ b/AfQxyVuLeCs.txt @@ -0,0 +1,1985 @@ +So, one question to ask +ourselves is, + +what is engineering? +How do we define, + +what is engineering? +Well, the definition I like to + +use is one put forth by Steve +Senturia, one of our professors + +who is now retired. +He defined engineering to be + +the purposeful use of science. +All right, so what is 6.002 + +about? +So, 6.002 is a first course in + +engineering. +And I like to view 6.002 as the + +gainful employment of Maxwell's +equations. + +Many of you have seen Maxwell's +equations before. + +Most of you should have. +And they are hard stuff. + +6.002 is all about teaching you +how to simplify our lives, + +make things simple. +So, if you can gainfully employ + +Maxwell's equations, +gainfully employ the facts of + +nature to build very interesting +systems. + +So let me show you how the +transition is made. + +So, there's a world around us, +nature, so we made some + +observations in nature. +We make measurements, + +and we can write down large +tables of measurements. + +So, for example, +we can take objects and measure + +the voltage across them, +and look at the resulting + +current through the elements. +So, we may end up getting a + +bunch of values such as +[CHALKBOARD]. + +So, we start out life with +making measurements on what + +exists. +And we build a bunch of tables. + +Now, we could directly take +these tables, + +and based on observations of +these tables, + +we could go ahead and build +very interesting engineering + +systems that help us out in +day-to-day lives. + +But that's incredibly hard. +Imagine having to resort to a + +set of tables to do any kind of +useful work. + +So what we do as engineers, +we first layer a level of + +abstraction. +We look at all the data, + +and somehow layer abstraction +such that we can simplify or + +much more succinctly put in a +simple equation or a simple + +statement what these numbers are +telling us. + +OK, so for example, +our physics laws, + +so laws of physics for example +are simply abstractions, + +the laws of abstractions. +So, these sets of numbers can + +be codified by Ohm's law, +for example, + +V is equal to RI, +the voltage current, + +relates to the resistance of +the object. + +So, V is equal to RI is a law +that succinctly describes a set + +of experiments, +and replaces a large number of + +tables with a very simple +statement. + +You could call this the law, +or you could call it an + +abstraction. +OK so you see laws of physics, + +call them abstractions of +physics if you like. + +Similarly, there are Maxwell's +equations and so on and so + +forth. +So, this is what is. + +This is what's out there. +OK, and a law as an abstraction + +describe the properties of +nature, as we see it, + +in some succinct form. +Now, if you want to go and + +build useful things, +we could take these + +abstractions, +take Maxwell's equations, + +and go and build things. +But it's hard. + +It's really, +really hard. + +And what you learn in, +at MIT is this place is all + +about simplifying things. +Take complicated things, + +build layers of abstraction, +and simplify things so that we + +can build useful systems. +Even in 6.002 we start life by + +making a huge leap from +Maxwell's equations to a couple + +of very, very simple laws. +OK, I'm going to show you that + +leap that we will make today. +So, the first abstraction that + +we layer is called the lump +circuit abstraction. + +OK, in the lump circuit +abstraction, what we do is we + +make a set of simplifications +that allows us to view a set of + +objects as discrete or lumped +elements. + +So, we may, I will define +voltage sources. + +We'll define resistors. +We'll define capacitors, + +and so on. +OK, and I'm going to make the + +jump, and show you how we make +the jump in a few minutes. + +So, on that sort of +abstraction, we then layer yet + +another abstract layer. +And let me call that the + +amplifier abstraction. +OK, remember, + +here we are absolutely down and +dirty. + +We are setting the probes, +measuring objects, + +and building huge tables. +We abstracted things into + +simple laws, and life got a +little better. + +OK, I'm going to show you can +abstract things further out and + +build discrete objects, +and, you could build even more + +interesting components called +amplifiers and begin playing + +around with amplifiers. +OK, so when you are using + +amplifiers, you don't really +have to worry about the details + +of Maxwell's equations. +OK, I'll give you some very + +simple abstract rules of +behavior for an amplifier, + +and you can go build very +interesting systems without + +really, really knowing how +Maxwell's equations applies to + +that because you will be working +at this abstract layer. + +However, since you're +engineers, and you are good at + +building such systems, +it's very important for you to + +understand how we make this leap +from the laws of physics into + +some of our very primitive +engineering abstractions. + +So, once we make the amplified +abstraction in 6.002, + +by the way, 6.002 starts here. +We start from the laws of + +physics and then proceed all the +way out. + +So, once we talk about +amplifiers we will take two + +pads. +On the amplifier, + +you will build the next +abstraction called the digital + +abstraction. +OK, and with the digital + +abstraction, we will build new +elements such as inverters and + +combinational gates, +OK? + +So, notice we are building +bigger, and bigger things, + +which have more and more +complicated behavior inside + +them, but which are very simple +to describe, right? + +So, following the digital +abstraction, we will superimpose + +the combinational logic +abstraction on top of that, + +and define functional blocks +that look like this: + +some inputs, +some function, + +some outputs. +The next abstraction on top of + +that will be the clock digital +abstraction, where we will have + +some notion of time introduced +into the system. + +There will be a clock, +and this will be some function. + +And there will be a clock that +introduces time into the sort of + +logic values that functions +operate upon. + +Following that, +the next level of abstraction + +that we build is called +instruction set abstraction. + +OK, now you begin to see things +that consumers get to look at. + +Can someone give me an example +of, or name an instruction set, + +or instruction set abstraction? +Bingo. + +So, x86 is one set of +abstractions. + +And in fact, +in many universities, + +education could well start just +by saying, OK, + +here's an abstraction. +These are the x86 instructions, + +OK? +Some MIT gurus have designed + +this awesome little +microprocessor, + +OK? +So you just worry about, + +you take this abstraction layer +here, the assembly instructions, + +and you go and build systems on +top of that. + +OK, so this is an abstraction +layer called the x86 layer. + +There are other abstraction +layers. + +In 6.004, you will learn about, +I believe, the alpha or the + +beta, OK, and various other +abstractions at this point. + +So, 6.002 kind of goes until +here. + +6.002 takes me from the world +of physics all the way to the + +world of interesting analog and +digital systems. + +OK, 004, the course on +computation structures, + +will show you how to build +computers all the way from + +simple digital objects all the +way to big systems. + +Following that, +you learn about language + +abstractions, +Java, C, and other languages, + +and that's in 6.002. +And there are several other + +courses that will cover that. +Following this, + +you learn about software system +abstractions, + +and software systems, +you will learn about operating + +systems. +Any example of an operating + +system abstraction that people +know out there? + +What's that? +Linux. + +What else? +I'm just wondering how long + +I'll have to go before I hear +what I want to hear. + +[LAUGHTER] OK, +so we have a bunch of software + +systems. +So, if we have a bunch of + +software systems, +these are nothing but + +abstractions. +Linux simply implies a set of + +system calls that the programs +must adhere to. + +Windows is another set of +system calls. + +That's it. +And see how much money they + +made out of it? +OK, it's all about abstraction + +layers, that all start from +nature. + +All right? +Build abstraction upon + +abstraction upon abstraction +upon abstraction, + +and someone out here are lots +of dollars. + +OK, so based on these +abstractions, + +we can then build useful things +for human beings. + +We can build very useful +things, video games, + +so we can send space shuttles +up, and a whole bunch of other + +systems. +But it's based on these + +abstraction layers. +What's unique about education + +at MIT? +What's unique about 6.002 and + +EECS? +Is to my knowledge, + +there are not many other places +in the world where you will get + +an education in everything going +all the way from nature to how + +to build very complicated analog +and digital systems. + +OK, we will show you layer upon +layer upon layer upon layer, + +peel away the onion until you +are down to raw nature, + +OK, through Maxwell's +equations. + +So, 6.002, 004, +this is 033, + +OK, 6.170, and so on. +OK, the whole EECS is about + +building abstraction layers, +one on top of the other. + +So that's one path. +There's the analog path. + +The analog path would take an +amplifier, and build an + +abstraction layer called the +op-amp. + +See how similar they all look? +You know the amplifier, + +the inverter of the digital +world, and the operational + +amplifier in the analog world, +just different ways of looking + +at the same devices. +So, to build an analog system, + +to build an operational +amplifier, and then, + +here we go end up building a +whole bunch of different + +interesting analog system +components. + +OK, and these components might +look like oscillators. + +They might look like filters. +OK, they look like power + +supplies, a whole bunch of very +interesting abstract components, + +which pulled together can then +give you the next set of + +systems. +And these systems might be + +toasters, or say for example +other analog systems like the + +various control systems for +various power plants and so on + +and so forth, +and ultimately, + +fun and dollars. +OK, so 6.002 is about going + +from physics all the way to this +point. + +We will build interesting +analog systems, + +and take you up to interesting +digital system components, + +from which 004 will take you +all the way to building computer + +architectures. +So that, in a nutshell, + +kind of gives you a feel for +the space of EECS. + +OK, this chart here is almost a +vignette of what EECS at MIT is + +all about. +And this is the world according + +to Agarwal, because he's +teaching 002. + +OK, so this is 6.002, +and the rest of EECS is + +somewhere out there. +OK, so I'm going to do now is + +throughout this course; +I want you to think about which + +part in this vignette we are in. +So, right now, + +I'm going to start here and +take you here. + +OK, and as you get closer and +closer, things get simpler, + +and simpler, +and simpler. + +Still, the final abstractions +are pedal, brake, + +steering wheel. +I mean, that's the abstraction + +to play a game, +right, four or five very simple + +interfaces, and that's all you +need to know. + +And everybody in the world can +play stuff. + +So remember, +this stuff is complicated. + +This stuff is very, +very simple. + +OK, and the more we build +abstractions and come to this + +side, things get simpler and +simpler. + +So, a large part of what I'll +cover today is make the biggest + +simplification. +The biggest simplification we + +will make his go from Maxwell's +equation to some very, + +very simple algebraic rules. +OK, I did Maxwell's equations + +myself. +And I tell you, + +they were very interesting +stuff but complicated. + +I can't imagine building +efficient systems using + +Maxwell's equations. +So, let's take an example, + +OK? +So, let's say I have a battery. + +Just switch to page three of +your course notes. + +And let's say I connect that to +a bulb. + +OK, and this is a wire. +And, the battery supplies some + +voltage, V, and I ask you a +simple question. + +What is the current through the +bulb? + +OK, so here is something that I +can build using objects. + +I can pick a round from stores +and so on. + +And I can collect them up in +this way, and ask the question, + +what is the current, +I? + +Now, if all you've done is +learn about Maxwell's equations, + +you can roll up your sleeves +and say, ah-ha! + +The first step is to write down +all of Maxwell's equations, + +and you can say, +del cross E is minus del and go + +on, and on, and on, +OK, and write out all of + +Maxwell's equations and say, +now how do I get from there to + +here? +OK, it's very good. + +You can do it. +OK, you can do it, + +but it's very complicated. +OK, so instead, + +what you're going to do is take +the easy way. + +So, what I want to remind you +is that this course is actually + +very easy. +OK remember, + +we're going to be building +abstraction upon abstraction to + +make your lives easier. +If you think your lives are + +getting more complicated, +then you are not using + +intuition enough. +OK, just remember the big I + +word. +It's all about making things + +simple. +OK, so let me give you an + +analogy. +So, suppose you have an object. + +OK, and I apply a force to the +object. + +It's an analogy, +OK to get some insight into how + +to do this. +So, I say here's an object. + +I apply a force, +and I ask you the question. + +What is the acceleration of the +object when I apply a force, + +F? +So, how would you do it? + +OK, and eighth, +or ninth, or tenth grader can + +do this. +OK, they would ask me, + +what's the mass of the object? +OK, I ask you what is the + +acceleration? +You would turn around and ask + +me, what is the mass of the +object? + +I tell you, the mass of the +object is M. + +And then you say, +oh sure, A is F divided by M, + +done. +It's as simple as that. + +OK, I could have gone into all +kinds of differential equations + +and so on to figure that out, +but you asked me for the mass. + +And you gave me the answer, +A is F divided by M. + +So, you ignored a bunch of +things. + +You ignored the shape of the +object. + +You ignored its color. +You ignored its temperature. + +OK, and you ignored the soft or +hard or whatever. + +OK, you ignored a whole bunch +of things. + +You were focused on one thing. +OK, you're focused on its mass. + +And, it turns out that the +process really was developed + +from a set of simplifications. +That is called, + +does anybody remember this? +Point mass simplification. + +OK, so, in physics, +you've done this before. + +OK, you've simplified your +lives by viewing objects as + +having a mass at a point, +and force is acting at that + +point. +OK, M is that property of the + +object that is of interest to +you. + +This process is called, +in physics, point mass + +discretization. +OK, now using an analogy, + +and I'm going to show you a +similar simple process to do the + +problem with the light bulb. +OK, so take my light bulb + +again, + +And I focus on the filament of +the light bulb. + +OK, all I care about is the +current flowing through the + +light bulb. +OK, I don't care about whether + +the filament is twisted, +whether it's hot. + +I don't care about its shape. +I don't care about its color. + +All I care about is the +current. + +OK, so to do that, +what we can do here at a very + +high level is since we just need +the current and don't care about + +a bunch of other properties, +we will simply replace the bulb + +with a discrete object called a +resistor. + +So the discrete object is a +resistor, much like the point + +mass simplification that we did +earlier that replaced the bulb + +filament with a object called a +resistor, a discrete object + +called a resistor. +Or a lump object called + +resister, and put a value next +to it just like the mass for the + +object, a resistance value, +R. + +OK, now what I can do is in the +same manner, replace the battery + +with an object called a battery +object, and connect that here, + +the voltage, +V, applied to it. + +V falls across the resistor, +and I get my I simply from + +Ohm's law as we divide by R. +So, notice here, + +to replace this complicated +bulb, this really twisty, + +weird old thing with this +discreet thing called a + +resistor, and its only property +of interest was its resistance + +value, R, direct analogy to what +we did there. + +So, since R represents the only +property of interest, + +we can simply ignore all the +other things. + +So, notice here, +we've done things the simple + +way. +And remember, + +in EE, in the electrical +engineering, we do things the + +simple way. +OK, we could go the hard route + +and do Maxwell's equations, +and get PhD's in physics, + +and so on. +But out here, + +we are looking to do useful, +interesting systems in the + +simplest way that we can. +OK, we do things a simple way. + +All right, so we just did this, +and boom, I found out what the + +current was. +Now, I cheated a little bit. + +I've cheated a little bit. +R is a lumped abstraction for + +the bulb. +So, you look at this resistor + +here. +That is simply a placeholder. + +It's a stand-in for this +complicated thing called a bulb. + +It's a discreet object. +It's a lumped object, + +and represents the bulb. +Now, so most of 6.002 will take + +off from here, +OK, and that's it. + +To very simple stuff, +like V is equal to IR, + +it's a simple high school +algebra to take off in that + +direction. +But before we go there, + +it's important to understand, +why was it that we were able to + +make the simplification? +OK, we did something else. + +Something's going on under the +covers here. + +On the one hand, +I say let's use Maxwell's, + +and then I jump out and say, +hey, we can just use this + +simple thing. +I did something that allowed me + +to go from here to here. +And you need to understand why + +I did that and how I did that. +Understand it once, + +and then you won't have to need +that information again. + +You just need to understand it. +So, let's take a closer look at + +the bulb filament, +and look at what we really did. + +So, here's my filament, +A, and let's say that the + +surface area here, +I label that SA, + +and the one down here SB, +my voltage, V, + +applied there, +and this is what I call my + +black box that I've replaced +with a resistor. + +Notice that, +in order for this to work, + +V and I need to be defined. +So I needs to be defined, + +and V needs to be defined. +OK, if I give you a random + +object, and I don't tell you +anything else about the object, + +it's not clear I can do that. +OK, if it's a much more general + +situation, I have to write down +Maxwell's equations, + +and this is what I would write +down. + +Write down J dot dS as a +function of the coordinate here + +integrated over the area minus, +OK, I would have to start from + +there from one of Maxwell's +equations. + +All right, notice that this +becomes IA, and this becomes IB + +in our simplification. +But, if I don't tell you + +anything else, +you have to start from here. + +You will have some varying +current here by point. + +You might have some other +current coming out here because + +I may have some charge buildup +happening inside. + +If charge is building up inside +the filament; + +then I would have to put del q +by del t out here, + +right, the current in minus the +current out must equal charge + +buildup. +Whoa, where is this and where + +is that? +So this is reality. + +This is really, +really what I have to do. + +But how did I get there? +How did I get there? + +The key answer is, +as engineers, + +when in doubt we simplify. +Remember, we are engineers. + +Our goal in life is to build +interesting systems. + +OK and some are motivated by +money. + +OK, so our goal is to build +interesting systems and do good + +to humanity. +So, as long as we can build a + +good light bulb, +we are happy. + +So what we can do is we can +say, look, all I care about is + +building interesting systems. +So I can say, + +hey, this stuff is too hard. +Let's make the assumption that + +all the systems that we will +consider will have this thing be + +zero. +OK, in other words, + +if I take a complete object, +if I take an element like a + +resistor or a capacitor, +the box around the entire + +element, OK, and I want to just +deal with those systems in which + +this thing is zero. +You can come and beat me up and + +say, but why? +Why not? + +Why am I doing this? +And I am saying the world is + +arbitrary. +I'm an engineer; + +I want to build good systems. +By making this simplification, + +I eliminate this squiggle +thing, and so on. + +I don't want to deal with it. +I want to make my life simple. + +So this is gone to zero +because, why? + +Because I have said that in the +future I will only deal with + +those elements for which this is +true. + +I'm going to discipline myself. +I'm going to discipline myself + +to only deal with those systems. +OK, Maxwell is turning around + +and, you know, +mad at me and all that stuff, + +but tough. +So this, what I've said about + +making a simplification here, +and this is one of the + +simplifications I'm making. +And I give a name to the + +simplification. +And that's called the lumped + +matter discipline. +OK, so I'm saying I will only + +deal with elements for which if +I put a black box around it, + +this is going to be true. +And if this is going to be + +true, then notice, +there is no charge buildup. + +Current in must equal current +out. + +Ah-ha! +So this becomes IA. + +This becomes IB. +Yes. + +OK, I can now deal with IA's +and IB's. + +And IB and IA are equal because +this is zero. + +Notice that there is a whole +bunch of depth here in the jump + +from here to here. +As MIT graduates, + +you really, really need to +understand why it is that we + +made that jump, +and then go and use that, + +and do cool things. +All right, this allows us to + +define I. +We have a unique I associated + +with an element for the current +through the element. + +We still have to worry about B, +and I won't go through that in + +detail. +The course notes have some + +discussion of that and so does +the textbook. + +So V, AB is defined when del +phi B, the rate of change of + +magnetic flux is zero. +So, if I take the element and I + +take any region outside the +element, this must be true. + +And you say, +why should that be true? + +That's not true in general. +Absolutely. + +It's not true in general. +But I, because I choose to, + +I going to deal with only those +elements. + +I will discipline myself. +But these are only those + +elements for which this is true, +and this is true. + +I'm going to limit my world. +I'm going to create a play + +field for myself. +You want to play; + +follow my rules. +OK, and that's called the + +lumped matter discipline. +So once you say that I'm going + +to adhere to the lump matter +discipline, and this is true + +inside your elements. +This is true outside the + +elements. +You can define VA and VB, + +and good things happen to you. +OK, let me show you a few + +examples of lumped elements. +But remember, + +a large part of what we're +doing is based on these two + +assumptions. +And to just go through the + +background on that, +I would encourage you to go to + +chapter 1 of your course notes +and read through just as how + +this came about, +that comes about. + +So, by doing that by adhering +to a lumped matter discipline, + +we can now lump objects. +We could lump a bulb into a + +resistor. +OK, so to be clear, + +a certain number of lumped +objects, and now, + +the universe is going to be +comprised into lumped objects. + +OK, so before this, +when he went home, + +we talked about eggs, +and omelets, + +and light bulbs, +and switches, + +but once you come to MIT, +and after you've taken 6.002, + +you begin talking about lumped +elements, you know, + +resistors, voltage sources, +capacitors, little inky-dinky + +objects that follow the lumped +matter discipline. + +OK, they stick to very simple +rules, and the math that you + +have to do to analyze them is +incredibly simple. + +What could be simpler than V is +equal to IR? + +So, let me give you an example +of interesting lumped elements, + +and then show you a couple of +really nasty lumped elements. + +OK. + +OK, so what you see out here, +so we characterize lumped + +elements by the VI +characteristics. + +OK, you apply voltage, +measure the current. + +OK, so what I can do is I can +plot I here, and V here, + +and see what it looks like. +OK, I can characterize elements + +by their VI relationship. +And there are a bunch of + +elements that I can create based +on the VI relationship. + +So let me show you a few +examples. + +So for the resistor, +since V is directly + +proportional to I, +and R is a constant, + +I get a straight line. +That's the I axis, + +the V axis, and this is the +resistor. + +What I actually have is a +variable resistor, + +so I'm going to change the +resistance value, + +R, and the curve will also +change slope. + +OK, I changed the value of R +because it's a variable + +resistor, and the changes slope +because my R is different. + +OK, next, let me go to a fixed +resistor, and this guy here on + +the screen to your left is a +fixed resistor. + +And you see that its IV +characteristic is a line of a + +given slope, 1 by R, +and that's it. + +I can't change it. +Number three, + +I have another lumped element +called a Zener diode that you + +will see in the fourth week of +this class, and the + +characteristics for the Zener +diode look like this: + +IV. +If my voltage goes across the + +Zener diode goes up slightly, +the current shoots up. + +But if the voltage becomes +negative I don't have any + +current flowing into it until +the voltage passes on the + +threshold, at which point my +current begins to build up. + +OK, so I can increase the +voltage a little bit, + +and it can show that the +current starts building up + +again. +So that's another interesting + +lumped element called a Zener +diode. + +Let's switch to the next one +called a diode. + +So a diode looks like this: +IV. + +As the voltage across the diode +becomes positive, + +around .6 volts, +or thereabout, + +the current begins to shoot up. +But when the voltage is below + +that threshold of .6, +then my current is almost zero. + +It's another lumped element +called a diode. + +And you will begin using these +elements in your 002 lives to + +build interesting systems. +The next example is a + +thermistor. +A thermistor is a resistor + +whose resistance varies with +temperature. + +OK, so this is a very expensive +little hairdryer, + +and what I'm going to do is +blow some hot air at my + +resistor, and you're going to +see that its value is going to + +change depending on how much I +heat it. + +So as it cools down, +let me cool it down, + +so you can see it's coming +down. + +I can zap it again. +I could do this all day. + +This is so much fun. +OK, so that's another + +interesting lumped element. +As the temperature rises, + +its resistance changes. +The next thing is called a + +photo resistor. +It's a resistor. + +It used to be a resistor; +Lorenzo? + +Oh OK, that's fine. +So this is a photo resistor. + +And notice that it almost +behaves like an open circuit. + +But what I'm going to do is +shine some light on it. + +When I shine light on it, +it begins to conduct and + +becomes a resistor of some +value. + +There you go. +OK, so that's a photo resistor. + +So now I'm going to show you a +battery. + +Notice we did talk about +batteries before. + +I'll show you a battery. +So before you show a battery, + +just thinking your own minds, +what should the IV + +characteristic of a battery look +like? + +IV. +A battery supplies a constant + +voltage. +You know your little cell, + +the AA battery, +1.5 volts? + +So, think of what the IV +characteristic of a battery + +should look like for three +seconds before it shows you. + +This is the one I showed, +Lorenzo?. + +It's a straight line. +This is a good battery. + +It's a straight, +vertical line, + +but says that the voltage is +1.5 volts, or thereabouts. + +No matter what current it +supplies as an ideal voltage + +source, it has a fixed voltage, +V, and no matter what the + +current going through is. +Now, I'll show you a dud, + +a bad battery, +and this is what the bad + +battery looks like. +So, many of you have had your + +car batteries die on you. +When you go to the store, + +they check your batteries. +They use exactly this + +principle, that dead batteries +have resistance. + +By the way, you see slopes +here. + +You're thinking of resistance. +OK, they can use this property + +to figure out that your battery +is dead. + +So that's a dead battery. +And finally, + +let me show you a bulb. +We started with a bulb, + +and so I need to end, +OK, we started with a bulb, + +so I need to end with a bulb. +And what you will see is that a + +bulb simply behaves like a +resistor. + +Its IV curve is going to look +like this. + +OK, notice this is my bulb. +And guess what, + +it behaves like a resistor. +It's a very interesting kind of + +resistor, so I won't go into +details for now. + +But notice its IV +characteristic behaves like a + +resistor. +OK, so those are some pretty + +standard lumped elements. +You deal with a lot more sets + +of lumped elements, +switches, MOSFETs, + +capacitors, inductors, +a bunch of other fun stuff. + +But before we do that, +what I wanted to tell you, + +don't go berserk on this +abstraction binge. + +Too much of anything is bad for +you. + +So what I'm going to show you +is, abstractions or models are + +only valid provided you work +within a set of constraints. + +Notice, we have already had +this tacit handshake which said + +that we follow the discipline. +Even after we follow the + +discipline, there are ranges to +how well physical elements can + +behave like ideal lumped +elements. + +OK, for example, +what we will do is show you the + +resistor. +And it's going to look like a + +resistor. +And I'm going to keep + +increasing the voltage around +it. + +OK, what's going to happen at +some point? + +I just keep doing that. +If it's an ideal element, + +if you're a theorist, +you say, oh yeah, + +the curve will keep extending +until I reach infinity. + +But this is a practical +resistor, so people out here can + +cover your eyes or something. +OK, so you're abstraction can't + +predict that. +All it says is the current is + +an amp. +It can't predict the heat, + +light, or the smell. +In the laboratory, + +even, you get the smell. +You know what somebody has just + +done. +So that's one example of the + +lumped abstraction breaking +down. + +So, if I really believe that my +own BS, anything is a lumped + +element. +So here's a pickle. + +A pickle is a lumped element. +I can choose it as a lumped + +resistor. +But this is a very interesting + +lumped resistor. +Don't try this at home. + +This is a standard pickle into +which you are pumping 110 V AC. + +I promise you, +this is a standard pickle. + +So, it has a fixed resistance, +but your lumped abstraction + +cannot predict the nice light +and sound effect. + +OK, so the last two or three +minutes what I want to do, + +so remember, +don't get carried away by + +abstractions. +There are limits. + +OK, you can't predict +everything. + +OK, that's the smell of a +pickle. + +OK, so let me give you a +preview of some upcoming + +attractions, and show you one +more quick simplification in the + +last few minutes. +So what we can do, + +once we build these lumped +elements, we can connect them in + +circuits. +OK, so I can build a circuit, + +of the sort. +So here's a voltage source with + +a bunch of resistors. +I can connect them with wires + +and build a circuit of the sort. +One interesting question we can + +ask ourselves is, +under the lumped matter + +discipline, what can we say +about the voltages? + +OK, if I go around the loop, +provided my world adheres to + +the lumped matter discipline, +what can I say about the + +voltages around this loop? +Ah-ha, Maxwell again, + +right? +So, I can write Maxwell's + +appropriate equation to solve +that. + +OK, voltages have something to +do with E and your integral of E + +dot dl and all of that stuff, +right? + +So this is the appropriate +Maxwell's equations to use. + +And I want to find out what +happens here. + +Now remember, +under LMD, I made the + +assumption. +OK, my world, + +my playground, +has del phi B by del t being + +zero. +The rate of change of flux is + +zero. +So, under these circumstances, + +I can write this. +I can break up this line + +integral into three parts across +the voltage source and across + +the two resistors and write that +down. + +OK, and then when I can do, +is now that the right-hand side + +is zero, I can simply take this. +And I know that E dot dl across + +this element is simply VCA. +This is VAB, + +and this is VBC equals zero. +OK, so when I make the + +assumption that del phi B by del +t is zero, and I go around this + +loop, apply Maxwell's equations, +what do I find? + +I find that the sum of the +voltages, VCA plus VAB plus VBC, + +is zero. +That's fantastic. + +So now, I could say hasta la +vista to this baby here. + +And I can focus on this guy and +say, Maxwell's equations, + +this thing with squiggles and +dels and all that stuff, + +can be simplified to the sum of +the voltages across a set of + +elements in a loop in a circuit +is zero. + +OK, and this is called +Kirchhoff's first first law, + +KVL. +OK, similarly, + +in recitation section, +you'll see the application of + +Kirchhoff's current law, +which comes from this be equal + +to zero, and all the currents +coming into a node being zero. + +So, KVL and KCl directly come +out of the lumped matter + +discipline. +And you can use those to solve + +circuits like this. \ No newline at end of file diff --git a/AmOVEZRyryk.txt b/AmOVEZRyryk.txt new file mode 100644 index 0000000000000000000000000000000000000000..7579564098ab08d920b93fe7876419624430ad35 --- /dev/null +++ b/AmOVEZRyryk.txt @@ -0,0 +1,115 @@ +align:start position:0% + +well I like to eat and cook and I like + + align:start position:0% +well I like to eat and cook and I like + + + align:start position:0% +well I like to eat and cook and I like +to learn different languages and I also + + align:start position:0% +to learn different languages and I also + + + align:start position:0% +to learn different languages and I also +noticed that the students were curious + + align:start position:0% +noticed that the students were curious + + + align:start position:0% +noticed that the students were curious +about my background my cultural + + align:start position:0% +about my background my cultural + + + align:start position:0% +about my background my cultural +background so I thought it would be nice + + align:start position:0% +background so I thought it would be nice + + + align:start position:0% +background so I thought it would be nice +to organize a seminar in which I could + + align:start position:0% +to organize a seminar in which I could + + + align:start position:0% +to organize a seminar in which I could +teach a little bit of Italian and then + + align:start position:0% +teach a little bit of Italian and then + + + align:start position:0% +teach a little bit of Italian and then +we just renovated the common kitchen so + + align:start position:0% +we just renovated the common kitchen so + + + align:start position:0% +we just renovated the common kitchen so +at tsg we also have this very nice big + + align:start position:0% +at tsg we also have this very nice big + + + align:start position:0% +at tsg we also have this very nice big +kitchen available for the whole + + align:start position:0% +kitchen available for the whole + + + align:start position:0% +kitchen available for the whole +community and I thought well maybe I can + + align:start position:0% +community and I thought well maybe I can + + + align:start position:0% +community and I thought well maybe I can +combine the two things and have a + + align:start position:0% +combine the two things and have a + + + align:start position:0% +combine the two things and have a +language course with the practice that's + + align:start position:0% +language course with the practice that's + + + align:start position:0% +language course with the practice that's +a with a real sort of immersion in the + + align:start position:0% +a with a real sort of immersion in the + + + align:start position:0% +a with a real sort of immersion in the +language and the culture \ No newline at end of file diff --git a/AqXOYgpbMBM.txt b/AqXOYgpbMBM.txt new file mode 100644 index 0000000000000000000000000000000000000000..9dcd9ea75efd501cca26765b552f5dcf372058b7 --- /dev/null +++ b/AqXOYgpbMBM.txt @@ -0,0 +1,1107 @@ +align:start position:0% + +hi there welcome back to recitation in + + align:start position:0% +hi there welcome back to recitation in + + + align:start position:0% +hi there welcome back to recitation in +lecture you've been learning about when + + align:start position:0% +lecture you've been learning about when + + + align:start position:0% +lecture you've been learning about when +vectors are + + align:start position:0% +vectors are + + + align:start position:0% +vectors are +dependent when they span a space what a + + align:start position:0% +dependent when they span a space what a + + + align:start position:0% +dependent when they span a space what a +basis is what a dimension of a vector + + align:start position:0% +basis is what a dimension of a vector + + + align:start position:0% +basis is what a dimension of a vector +space is and the problem for today is + + align:start position:0% +space is and the problem for today is + + + align:start position:0% +space is and the problem for today is +exactly about that we have a vector + + align:start position:0% +exactly about that we have a vector + + + align:start position:0% +exactly about that we have a vector +space that is given it's spanned by + + align:start position:0% +space that is given it's spanned by + + + align:start position:0% +space that is given it's spanned by +these four vectors and we're asked to + + align:start position:0% +these four vectors and we're asked to + + + align:start position:0% +these four vectors and we're asked to +find the dimension of that vector space + + align:start position:0% +find the dimension of that vector space + + + align:start position:0% +find the dimension of that vector space +and the basis for it well why don't you + + align:start position:0% +and the basis for it well why don't you + + + align:start position:0% +and the basis for it well why don't you +hit pause on the video and work on it + + align:start position:0% +hit pause on the video and work on it + + + align:start position:0% +hit pause on the video and work on it +for a while and I'll come back in a + + align:start position:0% +for a while and I'll come back in a + + + align:start position:0% +for a while and I'll come back in a +little bit to help you out with it all + + align:start position:0% +little bit to help you out with it all + + + align:start position:0% +little bit to help you out with it all +right we're back let's work on it well + + align:start position:0% +right we're back let's work on it well + + + align:start position:0% +right we're back let's work on it well +so we need to find the dimension and the + + align:start position:0% +so we need to find the dimension and the + + + align:start position:0% +so we need to find the dimension and the +basis remember what the dimension is + + align:start position:0% +basis remember what the dimension is + + + align:start position:0% +basis remember what the dimension is +it's simply the number of vectors in a + + align:start position:0% +it's simply the number of vectors in a + + + align:start position:0% +it's simply the number of vectors in a +basis for the vector space so actually + + align:start position:0% +basis for the vector space so actually + + + align:start position:0% +basis for the vector space so actually +the problems is backwards we want to + + align:start position:0% +the problems is backwards we want to + + + align:start position:0% +the problems is backwards we want to +find the basis for the space first and + + align:start position:0% +find the basis for the space first and + + + align:start position:0% +find the basis for the space first and +then find the dimension all right all + + align:start position:0% +then find the dimension all right all + + + align:start position:0% +then find the dimension all right all +right first here and second here all + + align:start position:0% +right first here and second here all + + + align:start position:0% +right first here and second here all +right so we want to find a basis for the + + align:start position:0% +right so we want to find a basis for the + + + align:start position:0% +right so we want to find a basis for the +vector space spanned by these four + + align:start position:0% +vector space spanned by these four + + + align:start position:0% +vector space spanned by these four +vectors all right so you might be + + align:start position:0% +vectors all right so you might be + + + align:start position:0% +vectors all right so you might be +tempted to just say that a basis for + + align:start position:0% +tempted to just say that a basis for + + + align:start position:0% +tempted to just say that a basis for +this vector space is those four vectors + + align:start position:0% +this vector space is those four vectors + + + align:start position:0% +this vector space is those four vectors +because they span the vector space but + + align:start position:0% +because they span the vector space but + + + align:start position:0% +because they span the vector space but +there's another thing that a basis has + + align:start position:0% +there's another thing that a basis has + + + align:start position:0% +there's another thing that a basis has +to satisfy and it is the elements of the + + align:start position:0% +to satisfy and it is the elements of the + + + align:start position:0% +to satisfy and it is the elements of the +basis have to be linearly independent + + align:start position:0% +basis have to be linearly independent + + + align:start position:0% +basis have to be linearly independent +and we don't know that these are so we + + align:start position:0% +and we don't know that these are so we + + + align:start position:0% +and we don't know that these are so we +have to check how do we check that four + + align:start position:0% +have to check how do we check that four + + + align:start position:0% +have to check how do we check that four +vectors are linearly independent + + align:start position:0% +vectors are linearly independent + + + align:start position:0% +vectors are linearly independent +well there's a couple of different ways + + align:start position:0% +well there's a couple of different ways + + + align:start position:0% +well there's a couple of different ways +but here's what we're going to do we're + + align:start position:0% +but here's what we're going to do we're + + + align:start position:0% +but here's what we're going to do we're +going to put these vectors as rows of a + + align:start position:0% +going to put these vectors as rows of a + + + align:start position:0% +going to put these vectors as rows of a +matrix and then we'll do elimination and + + align:start position:0% +matrix and then we'll do elimination and + + + align:start position:0% +matrix and then we'll do elimination and +when we get to the end the rows that + + align:start position:0% +when we get to the end the rows that + + + align:start position:0% +when we get to the end the rows that +have pivots are the independent ones so + + align:start position:0% +have pivots are the independent ones so + + + align:start position:0% +have pivots are the independent ones so +let's do that + + align:start position:0% +let's do that + + + align:start position:0% +let's do that +1 1 s 2 0 minus 1 1 2 0 minus 4 1 0 1 3 + + align:start position:0% +1 1 s 2 0 minus 1 1 2 0 minus 4 1 0 1 3 + + + align:start position:0% +1 1 s 2 0 minus 1 1 2 0 minus 4 1 0 1 3 +plus 3 2 + + align:start position:0% +plus 3 2 + + + align:start position:0% +plus 3 2 +- 3 0 minus 2 0 all right by now you + + align:start position:0% +- 3 0 minus 2 0 all right by now you + + + align:start position:0% +- 3 0 minus 2 0 all right by now you +must have done elimination a million + + align:start position:0% +must have done elimination a million + + + align:start position:0% +must have done elimination a million +times so I'll go a little bit faster 1 X + + align:start position:0% +times so I'll go a little bit faster 1 X + + + align:start position:0% +times so I'll go a little bit faster 1 X +2 X 1 0 1 0 + 2 - 4 - this one's already + + align:start position:0% +2 X 1 0 1 0 + 2 - 4 - this one's already + + + align:start position:0% +2 X 1 0 1 0 + 2 - 4 - this one's already +done 1 3 - 3 - 2 - 2 3 - 2 0 + 4 - 2 & 2 + + align:start position:0% + + + + align:start position:0% + +all right one more step 1 1 - 2 0 - 1 + + align:start position:0% +all right one more step 1 1 - 2 0 - 1 + + + align:start position:0% +all right one more step 1 1 - 2 0 - 1 +all these are done 0 1 2 x 4 2 0 1 minus + + align:start position:0% +all these are done 0 1 2 x 4 2 0 1 minus + + + align:start position:0% +all these are done 0 1 2 x 4 2 0 1 minus +1 is 0 3 minus 2 is 1 - 3 + 4 is 1 2 + + align:start position:0% +1 is 0 3 minus 2 is 1 - 3 + 4 is 1 2 + + + align:start position:0% +1 is 0 3 minus 2 is 1 - 3 + 4 is 1 2 +minus 2 is 0 1 minus 1 is 0 - 2 again + + align:start position:0% +minus 2 is 0 1 minus 1 is 0 - 2 again + + + align:start position:0% +minus 2 is 0 1 minus 1 is 0 - 2 again +and 0 oh you can see where this is going + + align:start position:0% +and 0 oh you can see where this is going + + + align:start position:0% +and 0 oh you can see where this is going +in the next step this row is going to + + align:start position:0% +in the next step this row is going to + + + align:start position:0% +in the next step this row is going to +disappear 1 1 minus 2 0 minus 1 0 1 - 2 + + align:start position:0% +disappear 1 1 minus 2 0 minus 1 0 1 - 2 + + + align:start position:0% +disappear 1 1 minus 2 0 minus 1 0 1 - 2 +0 0 1 1 0 0 0 0 0 0 all right we're done + + align:start position:0% +0 0 1 1 0 0 0 0 0 0 all right we're done + + + align:start position:0% +0 0 1 1 0 0 0 0 0 0 all right we're done +with elimination and so let's circle our + + align:start position:0% +with elimination and so let's circle our + + + align:start position:0% +with elimination and so let's circle our +pivots and here our pivots we have three + + align:start position:0% +pivots and here our pivots we have three + + + align:start position:0% +pivots and here our pivots we have three +pivots and so these three rows are + + align:start position:0% +pivots and so these three rows are + + + align:start position:0% +pivots and so these three rows are +linearly independent + + align:start position:0% +linearly independent + + + align:start position:0% +linearly independent +now and in fact these rows still span + + align:start position:0% +now and in fact these rows still span + + + align:start position:0% +now and in fact these rows still span +the same space that the initial four + + align:start position:0% +the same space that the initial four + + + align:start position:0% +the same space that the initial four +rows did because when you do elimination + + align:start position:0% +rows did because when you do elimination + + + align:start position:0% +rows did because when you do elimination +all that you're doing is recombining + + align:start position:0% +all that you're doing is recombining + + + align:start position:0% +all that you're doing is recombining +your rows while by doing linear + + align:start position:0% +your rows while by doing linear + + + align:start position:0% +your rows while by doing linear +combinations of them so for example your + + align:start position:0% +combinations of them so for example your + + + align:start position:0% +combinations of them so for example your +first rows stay the same throughout your + + align:start position:0% +first rows stay the same throughout your + + + align:start position:0% +first rows stay the same throughout your +second row was replaced by Row 2 minus + + align:start position:0% +second row was replaced by Row 2 minus + + + align:start position:0% +second row was replaced by Row 2 minus +Row 1 but it's really still spanning the + + align:start position:0% +Row 1 but it's really still spanning the + + + align:start position:0% +Row 1 but it's really still spanning the +same space and it goes on and then the + + align:start position:0% +same space and it goes on and then the + + + align:start position:0% +same space and it goes on and then the +fourth row it turns out was useless + + align:start position:0% +fourth row it turns out was useless + + + align:start position:0% +fourth row it turns out was useless +you only need to the first three so the + + align:start position:0% +you only need to the first three so the + + + align:start position:0% +you only need to the first three so the +elements for a basis well they will be + + align:start position:0% +elements for a basis well they will be + + + align:start position:0% +elements for a basis well they will be +these three let me write that basis 1 5 + + align:start position:0% +these three let me write that basis 1 5 + + + align:start position:0% +these three let me write that basis 1 5 +minus 2 0 minus 1 4 2 0 0 1 1 0 could + + align:start position:0% +minus 2 0 minus 1 4 2 0 0 1 1 0 could + + + align:start position:0% +minus 2 0 minus 1 4 2 0 0 1 1 0 could +you have used the first three rows yes + + align:start position:0% +you have used the first three rows yes + + + align:start position:0% +you have used the first three rows yes +you could you can't always do that + + align:start position:0% +you could you can't always do that + + + align:start position:0% +you could you can't always do that +sometimes in elimination you have to + + align:start position:0% +sometimes in elimination you have to + + + align:start position:0% +sometimes in elimination you have to +switch rows because there's a zero where + + align:start position:0% +switch rows because there's a zero where + + + align:start position:0% +switch rows because there's a zero where +a pivot should be when that happens you + + align:start position:0% +a pivot should be when that happens you + + + align:start position:0% +a pivot should be when that happens you +have to use these three or you have to + + align:start position:0% +have to use these three or you have to + + + align:start position:0% +have to use these three or you have to +keep track of which row you switched to + + align:start position:0% +keep track of which row you switched to + + + align:start position:0% +keep track of which row you switched to +go back and use the initial ones but + + align:start position:0% +go back and use the initial ones but + + + align:start position:0% +go back and use the initial ones but +it's really safe to use these ones and + + align:start position:0% +it's really safe to use these ones and + + + align:start position:0% +it's really safe to use these ones and +also they're simpler than the ones that + + align:start position:0% +also they're simpler than the ones that + + + align:start position:0% +also they're simpler than the ones that +you started with so why not the other + + align:start position:0% +you started with so why not the other + + + align:start position:0% +you started with so why not the other +question that we had was what is the + + align:start position:0% +question that we had was what is the + + + align:start position:0% +question that we had was what is the +dimension of the vector space well this + + align:start position:0% +dimension of the vector space well this + + + align:start position:0% +dimension of the vector space well this +is the easy part the dimension of the + + align:start position:0% +is the easy part the dimension of the + + + align:start position:0% +is the easy part the dimension of the +vector space is 1 2 3 and that solves + + align:start position:0% +vector space is 1 2 3 and that solves + + + align:start position:0% +vector space is 1 2 3 and that solves +the problem but there's one more thing + + align:start position:0% +the problem but there's one more thing + + + align:start position:0% +the problem but there's one more thing +that I want to tell you I told you that + + align:start position:0% +that I want to tell you I told you that + + + align:start position:0% +that I want to tell you I told you that +there's a couple of ways to find out + + align:start position:0% +there's a couple of ways to find out + + + align:start position:0% +there's a couple of ways to find out +which of those four vectors are linearly + + align:start position:0% +which of those four vectors are linearly + + + align:start position:0% +which of those four vectors are linearly +independent and the one that I used was + + align:start position:0% +independent and the one that I used was + + + align:start position:0% +independent and the one that I used was +I put them in two rows and performed + + align:start position:0% +I put them in two rows and performed + + + align:start position:0% +I put them in two rows and performed +elimination and picked out the rows that + + align:start position:0% +elimination and picked out the rows that + + + align:start position:0% +elimination and picked out the rows that +have pivots on them another way to do it + + align:start position:0% +have pivots on them another way to do it + + + align:start position:0% +have pivots on them another way to do it +is to write the initial vectors as + + align:start position:0% +is to write the initial vectors as + + + align:start position:0% +is to write the initial vectors as +columns of the matrix and then perform + + align:start position:0% +columns of the matrix and then perform + + + align:start position:0% +columns of the matrix and then perform +elimination that also works and as you + + align:start position:0% +elimination that also works and as you + + + align:start position:0% +elimination that also works and as you +know because you're only working with + + align:start position:0% +know because you're only working with + + + align:start position:0% +know because you're only working with +the transpose of this matrix you can get + + align:start position:0% +the transpose of this matrix you can get + + + align:start position:0% +the transpose of this matrix you can get +the same number of pivots let's go over + + align:start position:0% +the same number of pivots let's go over + + + align:start position:0% +the same number of pivots let's go over +here where I have the same while the + + align:start position:0% +here where I have the same while the + + + align:start position:0% +here where I have the same while the +transpose of that matrix I have the same + + align:start position:0% +transpose of that matrix I have the same + + + align:start position:0% +transpose of that matrix I have the same +vectors but now written as columns my + + align:start position:0% +vectors but now written as columns my + + + align:start position:0% +vectors but now written as columns my +for initial vector is written as columns + + align:start position:0% +for initial vector is written as columns + + + align:start position:0% +for initial vector is written as columns +and here I have + + align:start position:0% +and here I have + + + align:start position:0% +and here I have +performed elimination and this is the + + align:start position:0% +performed elimination and this is the + + + align:start position:0% +performed elimination and this is the +final result let me circle the pivots + + align:start position:0% +final result let me circle the pivots + + + align:start position:0% +final result let me circle the pivots +again here they are three which is going + + align:start position:0% +again here they are three which is going + + + align:start position:0% +again here they are three which is going +to give me three independent three + + align:start position:0% +to give me three independent three + + + align:start position:0% +to give me three independent three +linearly independent vectors and hence + + align:start position:0% +linearly independent vectors and hence + + + align:start position:0% +linearly independent vectors and hence +three elements of the basis and hence + + align:start position:0% +three elements of the basis and hence + + + align:start position:0% +three elements of the basis and hence +dimension three for the vector space but + + align:start position:0% +dimension three for the vector space but + + + align:start position:0% +dimension three for the vector space but +I can no longer use these three these + + align:start position:0% +I can no longer use these three these + + + align:start position:0% +I can no longer use these three these +three columns as elements of the basis + + align:start position:0% +three columns as elements of the basis + + + align:start position:0% +three columns as elements of the basis +because when I did elimination I changed + + align:start position:0% +because when I did elimination I changed + + + align:start position:0% +because when I did elimination I changed +the column space so the column space of + + align:start position:0% +the column space so the column space of + + + align:start position:0% +the column space so the column space of +this vector of this matrix is not the + + align:start position:0% +this vector of this matrix is not the + + + align:start position:0% +this vector of this matrix is not the +same as the column space of the + + align:start position:0% +same as the column space of the + + + align:start position:0% +same as the column space of the +eliminated version so I cannot use these + + align:start position:0% +eliminated version so I cannot use these + + + align:start position:0% +eliminated version so I cannot use these +in fact if you look at them can probably + + align:start position:0% +in fact if you look at them can probably + + + align:start position:0% +in fact if you look at them can probably +understand that they're not going to + + align:start position:0% +understand that they're not going to + + + align:start position:0% +understand that they're not going to +span the same space as these because all + + align:start position:0% +span the same space as these because all + + + align:start position:0% +span the same space as these because all +that I have done here are zeros and I + + align:start position:0% +that I have done here are zeros and I + + + align:start position:0% +that I have done here are zeros and I +get a lot more than just zeros in the + + align:start position:0% +get a lot more than just zeros in the + + + align:start position:0% +get a lot more than just zeros in the +last two entries of the vectors so what + + align:start position:0% +last two entries of the vectors so what + + + align:start position:0% +last two entries of the vectors so what +I need to do is the pivots are in the + + align:start position:0% +I need to do is the pivots are in the + + + align:start position:0% +I need to do is the pivots are in the +first second and third columns I need to + + align:start position:0% +first second and third columns I need to + + + align:start position:0% +first second and third columns I need to +use these three columns as my basis I'll + + align:start position:0% +use these three columns as my basis I'll + + + align:start position:0% +use these three columns as my basis I'll +just write bases down here and that will + + align:start position:0% +just write bases down here and that will + + + align:start position:0% +just write bases down here and that will +work too so see I have produced two + + align:start position:0% +work too so see I have produced two + + + align:start position:0% +work too so see I have produced two +different basis for the same vector + + align:start position:0% +different basis for the same vector + + + align:start position:0% +different basis for the same vector +space which is totally fine you can pick + + align:start position:0% +space which is totally fine you can pick + + + align:start position:0% +space which is totally fine you can pick +the basis that you prefer all right + + align:start position:0% +the basis that you prefer all right + + + align:start position:0% +the basis that you prefer all right +we're done thank you \ No newline at end of file diff --git a/BGug_49cGYw.txt b/BGug_49cGYw.txt new file mode 100644 index 0000000000000000000000000000000000000000..6592a23088176894f5aa3c50ede7e66f4872201e --- /dev/null +++ b/BGug_49cGYw.txt @@ -0,0 +1,8923 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +hi today I'd like to continue the + + align:start position:0% +hi today I'd like to continue the + + + align:start position:0% +hi today I'd like to continue the +discussion of root Locust techniques + + align:start position:0% +discussion of root Locust techniques + + + align:start position:0% +discussion of root Locust techniques +that we started in the last session as + + align:start position:0% +that we started in the last session as + + + align:start position:0% +that we started in the last session as +you recall root Locust is one of the two + + align:start position:0% +you recall root Locust is one of the two + + + align:start position:0% +you recall root Locust is one of the two +principal methods that we're going to + + align:start position:0% +principal methods that we're going to + + + align:start position:0% +principal methods that we're going to +use to evaluate the stability of + + align:start position:0% +use to evaluate the stability of + + + align:start position:0% +use to evaluate the stability of +feedback systems the advantage of this + + align:start position:0% +feedback systems the advantage of this + + + align:start position:0% +feedback systems the advantage of this +technique along with the second + + align:start position:0% +technique along with the second + + + align:start position:0% +technique along with the second +technique which we'll introduce later is + + align:start position:0% +technique which we'll introduce later is + + + align:start position:0% +technique which we'll introduce later is +that it gives us a way to start with + + align:start position:0% +that it gives us a way to start with + + + align:start position:0% +that it gives us a way to start with +readily identifi identifiable quantities + + align:start position:0% +readily identifi identifiable quantities + + + align:start position:0% +readily identifi identifiable quantities +in particular the loop transmission of + + align:start position:0% +in particular the loop transmission of + + + align:start position:0% +in particular the loop transmission of +the feedback system and by rather + + align:start position:0% +the feedback system and by rather + + + align:start position:0% +the feedback system and by rather +straightforward analytic manipulations + + align:start position:0% +straightforward analytic manipulations + + + align:start position:0% +straightforward analytic manipulations +determine the closed loop transfer + + align:start position:0% +determine the closed loop transfer + + + align:start position:0% +determine the closed loop transfer +function or at least the important + + align:start position:0% +function or at least the important + + + align:start position:0% +function or at least the important +features of the closed loop transfer + + align:start position:0% +features of the closed loop transfer + + + align:start position:0% +features of the closed loop transfer +function we also find out that in + + align:start position:0% +function we also find out that in + + + align:start position:0% +function we also find out that in +addition to getting a binary answer to + + align:start position:0% +addition to getting a binary answer to + + + align:start position:0% +addition to getting a binary answer to +the stability problem in other words are + + align:start position:0% +the stability problem in other words are + + + align:start position:0% +the stability problem in other words are +there any poles of the closed loop + + align:start position:0% +there any poles of the closed loop + + + align:start position:0% +there any poles of the closed loop +transfer function in the right half of + + align:start position:0% +transfer function in the right half of + + + align:start position:0% +transfer function in the right half of +the S + + align:start position:0% +the S + + + align:start position:0% +the S +plane we're also able to get a very good + + align:start position:0% +plane we're also able to get a very good + + + align:start position:0% +plane we're also able to get a very good +analog measure of relative stability in + + align:start position:0% +analog measure of relative stability in + + + align:start position:0% +analog measure of relative stability in +other words we can find out how close + + align:start position:0% +other words we can find out how close + + + align:start position:0% +other words we can find out how close +our system is to instability we can tell + + align:start position:0% +our system is to instability we can tell + + + align:start position:0% +our system is to instability we can tell +once we've determined that our system is + + align:start position:0% +once we've determined that our system is + + + align:start position:0% +once we've determined that our system is +stable what the damping ratio of the + + align:start position:0% +stable what the damping ratio of the + + + align:start position:0% +stable what the damping ratio of the +dominant closed loop pole pair is and in + + align:start position:0% +dominant closed loop pole pair is and in + + + align:start position:0% +dominant closed loop pole pair is and in +fact you can determine many other + + align:start position:0% +fact you can determine many other + + + align:start position:0% +fact you can determine many other +features of the Clos Loop response that + + align:start position:0% +features of the Clos Loop response that + + + align:start position:0% +features of the Clos Loop response that +we might be interested + + align:start position:0% +we might be interested + + + align:start position:0% +we might be interested +in if you recall last time we in fact + + align:start position:0% +in if you recall last time we in fact + + + align:start position:0% +in if you recall last time we in fact +looked at a root Locus diagram remember + + align:start position:0% +looked at a root Locus diagram remember + + + align:start position:0% +looked at a root Locus diagram remember +that we present the results of root + + align:start position:0% +that we present the results of root + + + align:start position:0% +that we present the results of root +Locus analysis in a root Locus + + align:start position:0% +Locus analysis in a root Locus + + + align:start position:0% +Locus analysis in a root Locus +diagram and we started with a + + align:start position:0% +diagram and we started with a + + + align:start position:0% +diagram and we started with a +particularly simple system in particular + + align:start position:0% +particularly simple system in particular + + + align:start position:0% +particularly simple system in particular +we started with a system that had two + + align:start position:0% +we started with a system that had two + + + align:start position:0% +we started with a system that had two +poles associated with the loop + + align:start position:0% +poles associated with the loop + + + align:start position:0% +poles associated with the loop +transmission and no zeros both of those + + align:start position:0% +transmission and no zeros both of those + + + align:start position:0% +transmission and no zeros both of those +poles were located on the negative real + + align:start position:0% +poles were located on the negative real + + + align:start position:0% +poles were located on the negative real +axis at Min -1 over to a and min-1 over + + align:start position:0% +axis at Min -1 over to a and min-1 over + + + align:start position:0% +axis at Min -1 over to a and min-1 over +to B we then went ahead + + align:start position:0% +to B we then went ahead + + + align:start position:0% +to B we then went ahead +and wrote an expression for the closed + + align:start position:0% +and wrote an expression for the closed + + + align:start position:0% +and wrote an expression for the closed +loop transfer function and focused our + + align:start position:0% +loop transfer function and focused our + + + align:start position:0% +loop transfer function and focused our +attention on the characteristic equation + + align:start position:0% +attention on the characteristic equation + + + align:start position:0% +attention on the characteristic equation +in particular the denominator of the + + align:start position:0% +in particular the denominator of the + + + align:start position:0% +in particular the denominator of the +closed loop transfer function we were + + align:start position:0% +closed loop transfer function we were + + + align:start position:0% +closed loop transfer function we were +then able to solve that characteristic + + align:start position:0% +then able to solve that characteristic + + + align:start position:0% +then able to solve that characteristic +equation solve the root for the roots of + + align:start position:0% +equation solve the root for the roots of + + + align:start position:0% +equation solve the root for the roots of +that characteristic equation by setting + + align:start position:0% +that characteristic equation by setting + + + align:start position:0% +that characteristic equation by setting +it equal to zero and since the roots of + + align:start position:0% +it equal to zero and since the roots of + + + align:start position:0% +it equal to zero and since the roots of +the characteristic equation are the + + align:start position:0% +the characteristic equation are the + + + align:start position:0% +the characteristic equation are the +poles of the system closed loop transfer + + align:start position:0% +poles of the system closed loop transfer + + + align:start position:0% +poles of the system closed loop transfer +function we could determine how the + + align:start position:0% +function we could determine how the + + + align:start position:0% +function we could determine how the +closed loop transfer function poles + + align:start position:0% +closed loop transfer function poles + + + align:start position:0% +closed loop transfer function poles +varied in particular as we changed a fot + + align:start position:0% +varied in particular as we changed a fot + + + align:start position:0% +varied in particular as we changed a fot +for the system recall that a fot is the + + align:start position:0% +for the system recall that a fot is the + + + align:start position:0% +for the system recall that a fot is the +magnitude of the low frequency Loop + + align:start position:0% +magnitude of the low frequency Loop + + + align:start position:0% +magnitude of the low frequency Loop +transmission of the system when we + + align:start position:0% +transmission of the system when we + + + align:start position:0% +transmission of the system when we +perform that calculation Again by + + align:start position:0% +perform that calculation Again by + + + align:start position:0% +perform that calculation Again by +directly factoring the characteristic + + align:start position:0% +directly factoring the characteristic + + + align:start position:0% +directly factoring the characteristic +equation we found that the closed loop + + align:start position:0% +equation we found that the closed loop + + + align:start position:0% +equation we found that the closed loop +poles start very close to the location + + align:start position:0% +poles start very close to the location + + + align:start position:0% +poles start very close to the location +of the loop transmission poles for small + + align:start position:0% +of the loop transmission poles for small + + + align:start position:0% +of the loop transmission poles for small +values of a f in this particular system + + align:start position:0% +values of a f in this particular system + + + align:start position:0% +values of a f in this particular system +and then as a f inre increases the two + + align:start position:0% +and then as a f inre increases the two + + + align:start position:0% +and then as a f inre increases the two +poles the two closed loop poles move + + align:start position:0% +poles the two closed loop poles move + + + align:start position:0% +poles the two closed loop poles move +closer together and finally become + + align:start position:0% +closer together and finally become + + + align:start position:0% +closer together and finally become +coincident on the negative real axis at + + align:start position:0% +coincident on the negative real axis at + + + align:start position:0% +coincident on the negative real axis at +a location that's actually the + + align:start position:0% +a location that's actually the + + + align:start position:0% +a location that's actually the +arithmetic mean of the two Loop + + align:start position:0% +arithmetic mean of the two Loop + + + align:start position:0% +arithmetic mean of the two Loop +transmission pole + + align:start position:0% +transmission pole + + + align:start position:0% +transmission pole +locations further increases in a fnot + + align:start position:0% +locations further increases in a fnot + + + align:start position:0% +locations further increases in a fnot +beyond that necessary to get the two + + align:start position:0% +beyond that necessary to get the two + + + align:start position:0% +beyond that necessary to get the two +poles coincident result in the two poles + + align:start position:0% +poles coincident result in the two poles + + + align:start position:0% +poles coincident result in the two poles +branching off the real axis and getting + + align:start position:0% +branching off the real axis and getting + + + align:start position:0% +branching off the real axis and getting +an increasingly large imaginary + + align:start position:0% +an increasingly large imaginary + + + align:start position:0% +an increasingly large imaginary +portion as the two closed loop Pooles + + align:start position:0% +portion as the two closed loop Pooles + + + align:start position:0% +portion as the two closed loop Pooles +become a complex conjugate pair with an + + align:start position:0% +become a complex conjugate pair with an + + + align:start position:0% +become a complex conjugate pair with an +increasingly large imaginary component + + align:start position:0% +increasingly large imaginary component + + + align:start position:0% +increasingly large imaginary component +the real part stays fixed and so as a + + align:start position:0% +the real part stays fixed and so as a + + + align:start position:0% +the real part stays fixed and so as a +fnot increases why the two complex + + align:start position:0% +fnot increases why the two complex + + + align:start position:0% +fnot increases why the two complex +conjugate poles move off North and South + + align:start position:0% +conjugate poles move off North and South + + + align:start position:0% +conjugate poles move off North and South +in the S plane of course they have to be + + align:start position:0% +in the S plane of course they have to be + + + align:start position:0% +in the S plane of course they have to be +symmetrical with respect to the real + + align:start position:0% +symmetrical with respect to the real + + + align:start position:0% +symmetrical with respect to the real +axis since this is corresponds to the + + align:start position:0% +axis since this is corresponds to the + + + align:start position:0% +axis since this is corresponds to the +pole locations for a physically + + align:start position:0% +pole locations for a physically + + + align:start position:0% +pole locations for a physically +realizable system + + align:start position:0% + + + + align:start position:0% + +we found that we were able to + + align:start position:0% +we found that we were able to + + + align:start position:0% +we found that we were able to +determine the closed loop pole locations + + align:start position:0% +determine the closed loop pole locations + + + align:start position:0% +determine the closed loop pole locations +for our second order system by directly + + align:start position:0% +for our second order system by directly + + + align:start position:0% +for our second order system by directly +factoring the characteristic equation + + align:start position:0% +factoring the characteristic equation + + + align:start position:0% +factoring the characteristic equation +unfortunately that operation becomes + + align:start position:0% +unfortunately that operation becomes + + + align:start position:0% +unfortunately that operation becomes +tedious for anything other than first + + align:start position:0% +tedious for anything other than first + + + align:start position:0% +tedious for anything other than first +and second order systems and so today + + align:start position:0% +and second order systems and so today + + + align:start position:0% +and second order systems and so today +we'd like to look at the way we can + + align:start position:0% +we'd like to look at the way we can + + + align:start position:0% +we'd like to look at the way we can +construct the root Locust diagram + + align:start position:0% +construct the root Locust diagram + + + align:start position:0% +construct the root Locust diagram +without having to directly Factor the + + align:start position:0% +without having to directly Factor the + + + align:start position:0% +without having to directly Factor the +characteristic + + align:start position:0% +characteristic + + + align:start position:0% +characteristic +equation we call we have a standard + + align:start position:0% +equation we call we have a standard + + + align:start position:0% +equation we call we have a standard +topology which has a forward path + + align:start position:0% +topology which has a forward path + + + align:start position:0% +topology which has a forward path +transmission a of s and a feedback path + + align:start position:0% +transmission a of s and a feedback path + + + align:start position:0% +transmission a of s and a feedback path +transmission F of + + align:start position:0% +transmission F of + + + align:start position:0% +transmission F of +s when we write a closed loop transfer + + align:start position:0% +s when we write a closed loop transfer + + + align:start position:0% +s when we write a closed loop transfer +function for the system we of course + + align:start position:0% +function for the system we of course + + + align:start position:0% +function for the system we of course +find out that capital A of s the input + + align:start position:0% +find out that capital A of s the input + + + align:start position:0% +find out that capital A of s the input +to Output transfer function is simply + + align:start position:0% +to Output transfer function is simply + + + align:start position:0% +to Output transfer function is simply +equal to the forward path transmission + + align:start position:0% +equal to the forward path transmission + + + align:start position:0% +equal to the forward path transmission +over 1 minus the loop transmission we're + + align:start position:0% +over 1 minus the loop transmission we're + + + align:start position:0% +over 1 minus the loop transmission we're +not particularly worried initially about + + align:start position:0% +not particularly worried initially about + + + align:start position:0% +not particularly worried initially about +the location of zeros or initial + + align:start position:0% +the location of zeros or initial + + + align:start position:0% +the location of zeros or initial +considerations with root Locust + + align:start position:0% +considerations with root Locust + + + align:start position:0% +considerations with root Locust +techniques will focus only on how we + + align:start position:0% +techniques will focus only on how we + + + align:start position:0% +techniques will focus only on how we +find the poles of the system + + align:start position:0% +find the poles of the system + + + align:start position:0% +find the poles of the system +consequently we'll look only at the + + align:start position:0% +consequently we'll look only at the + + + align:start position:0% +consequently we'll look only at the +characteristic equation which we recall + + align:start position:0% +characteristic equation which we recall + + + align:start position:0% +characteristic equation which we recall +is one minus the loop transmission that + + align:start position:0% +is one minus the loop transmission that + + + align:start position:0% +is one minus the loop transmission that +characteristic equation is of course + + align:start position:0% +characteristic equation is of course + + + align:start position:0% +characteristic equation is of course +common for any system with uh equal + + align:start position:0% +common for any system with uh equal + + + align:start position:0% +common for any system with uh equal +values for the AF product remember that + + align:start position:0% +values for the AF product remember that + + + align:start position:0% +values for the AF product remember that +the zeros of closed loop transfer + + align:start position:0% +the zeros of closed loop transfer + + + align:start position:0% +the zeros of closed loop transfer +function are dependent on how Dynamics + + align:start position:0% +function are dependent on how Dynamics + + + align:start position:0% +function are dependent on how Dynamics +are distributed between the forward path + + align:start position:0% +are distributed between the forward path + + + align:start position:0% +are distributed between the forward path +and the feedback path but the poles of a + + align:start position:0% +and the feedback path but the poles of a + + + align:start position:0% +and the feedback path but the poles of a +closed loop transfer function are + + align:start position:0% +closed loop transfer function are + + + align:start position:0% +closed loop transfer function are +dependent only on the AF product well + + align:start position:0% +dependent only on the AF product well + + + align:start position:0% +dependent only on the AF product well +when we calculate the characteristic + + align:start position:0% +when we calculate the characteristic + + + align:start position:0% +when we calculate the characteristic +equation or one minus the loop + + align:start position:0% +equation or one minus the loop + + + align:start position:0% +equation or one minus the loop +transmission it's simply 1 plus a of s f + + align:start position:0% +transmission it's simply 1 plus a of s f + + + align:start position:0% +transmission it's simply 1 plus a of s f +of s recalling that the loop + + align:start position:0% +of s recalling that the loop + + + align:start position:0% +of s recalling that the loop +transmission is minus a of s f of s then + + align:start position:0% +transmission is minus a of s f of s then + + + align:start position:0% +transmission is minus a of s f of s then +we conclude that the poles of the closed + + align:start position:0% +we conclude that the poles of the closed + + + align:start position:0% +we conclude that the poles of the closed +loop transfer function capital A of s + + align:start position:0% +loop transfer function capital A of s + + + align:start position:0% +loop transfer function capital A of s +occur when 1 plus a of s F of s equals + + align:start position:0% + + + + align:start position:0% + +z we may choose to express the AF + + align:start position:0% +z we may choose to express the AF + + + align:start position:0% +z we may choose to express the AF +product as being equal to a fot times + + align:start position:0% +product as being equal to a fot times + + + align:start position:0% +product as being equal to a fot times +some G of s where we've included all of + + align:start position:0% +some G of s where we've included all of + + + align:start position:0% +some G of s where we've included all of +the frequency dependent portions of the + + align:start position:0% +the frequency dependent portions of the + + + align:start position:0% +the frequency dependent portions of the +loop Transmission in G of s and + + align:start position:0% +loop Transmission in G of s and + + + align:start position:0% +loop Transmission in G of s and +furthermore we'll choose to write G of s + + align:start position:0% +furthermore we'll choose to write G of s + + + align:start position:0% +furthermore we'll choose to write G of s +in a form such that g of0 is equal to + + align:start position:0% +in a form such that g of0 is equal to + + + align:start position:0% +in a form such that g of0 is equal to +one we'll normalize G of s so that the + + align:start position:0% +one we'll normalize G of s so that the + + + align:start position:0% +one we'll normalize G of s so that the +DC value of G of s is one in that case + + align:start position:0% +DC value of G of s is one in that case + + + align:start position:0% +DC value of G of s is one in that case +the quantity a fnot has the physical + + align:start position:0% +the quantity a fnot has the physical + + + align:start position:0% +the quantity a fnot has the physical +interpretation of being the magnitude of + + align:start position:0% +interpretation of being the magnitude of + + + align:start position:0% +interpretation of being the magnitude of +the DC Loop + + align:start position:0% +the DC Loop + + + align:start position:0% +the DC Loop +transmission suppose we'd like to + + align:start position:0% +transmission suppose we'd like to + + + align:start position:0% +transmission suppose we'd like to +perform a test suppose we're told + + align:start position:0% +perform a test suppose we're told + + + align:start position:0% +perform a test suppose we're told +that a particular system has a closed + + align:start position:0% +that a particular system has a closed + + + align:start position:0% +that a particular system has a closed +loop pole at a point in the S plane + + align:start position:0% +loop pole at a point in the S plane + + + align:start position:0% +loop pole at a point in the S plane +S1 and we' like to check to see if + + align:start position:0% +S1 and we' like to check to see if + + + align:start position:0% +S1 and we' like to check to see if +that's really true well that's easy to + + align:start position:0% +that's really true well that's easy to + + + align:start position:0% +that's really true well that's easy to +do if we're to close loop pole the + + align:start position:0% +do if we're to close loop pole the + + + align:start position:0% +do if we're to close loop pole the +characteristic equation the denominator + + align:start position:0% +characteristic equation the denominator + + + align:start position:0% +characteristic equation the denominator +of any transfer function for the system + + align:start position:0% +of any transfer function for the system + + + align:start position:0% +of any transfer function for the system +must in fact be equal to zero that's + + align:start position:0% +must in fact be equal to zero that's + + + align:start position:0% +must in fact be equal to zero that's +what we mean by a poll the denominator + + align:start position:0% +what we mean by a poll the denominator + + + align:start position:0% +what we mean by a poll the denominator +goes to zero consequently the transfer + + align:start position:0% +goes to zero consequently the transfer + + + align:start position:0% +goes to zero consequently the transfer +function in question becomes + + align:start position:0% +function in question becomes + + + align:start position:0% +function in question becomes +infinite so if we we are in fact at a + + align:start position:0% +infinite so if we we are in fact at a + + + align:start position:0% +infinite so if we we are in fact at a +poll of capital A of s the quantity 1+ a + + align:start position:0% +poll of capital A of s the quantity 1+ a + + + align:start position:0% +poll of capital A of s the quantity 1+ a +f time G of S1 must be equal to zero we + + align:start position:0% +f time G of S1 must be equal to zero we + + + align:start position:0% +f time G of S1 must be equal to zero we +can rearrange and recognize that that + + align:start position:0% +can rearrange and recognize that that + + + align:start position:0% +can rearrange and recognize that that +tells us that a FN time G of S1 must be + + align:start position:0% +tells us that a FN time G of S1 must be + + + align:start position:0% +tells us that a FN time G of S1 must be +equal to + + align:start position:0% + + + + align:start position:0% + +minus1 since a f g of s in general is a + + align:start position:0% +minus1 since a f g of s in general is a + + + align:start position:0% +minus1 since a f g of s in general is a +complex number we have to satisfy two + + align:start position:0% +complex number we have to satisfy two + + + align:start position:0% +complex number we have to satisfy two +conditions simultaneously to make it + + align:start position:0% +conditions simultaneously to make it + + + align:start position:0% +conditions simultaneously to make it +equal to minus1 in particular the + + align:start position:0% +equal to minus1 in particular the + + + align:start position:0% +equal to minus1 in particular the +magnitude of a f * G of s evaluated at + + align:start position:0% +magnitude of a f * G of s evaluated at + + + align:start position:0% +magnitude of a f * G of s evaluated at +the point s equal S1 must be equal to + + align:start position:0% +the point s equal S1 must be equal to + + + align:start position:0% +the point s equal S1 must be equal to +one and simultaneously the angle of the + + align:start position:0% +one and simultaneously the angle of the + + + align:start position:0% +one and simultaneously the angle of the +transfer function a f g of s evaluated + + align:start position:0% +transfer function a f g of s evaluated + + + align:start position:0% +transfer function a f g of s evaluated +the point S1 has to be equal to an odd + + align:start position:0% +the point S1 has to be equal to an odd + + + align:start position:0% +the point S1 has to be equal to an odd +multiple of + + align:start position:0% +multiple of + + + align:start position:0% +multiple of +180° however since we've chosen to + + align:start position:0% +180° however since we've chosen to + + + align:start position:0% +180° however since we've chosen to +include all of the Dynamics of our Loop + + align:start position:0% +include all of the Dynamics of our Loop + + + align:start position:0% +include all of the Dynamics of our Loop +Transmission in the quantity G of s the + + align:start position:0% +Transmission in the quantity G of s the + + + align:start position:0% +Transmission in the quantity G of s the +angle condition reduces to Simply Having + + align:start position:0% +angle condition reduces to Simply Having + + + align:start position:0% +angle condition reduces to Simply Having +the angle of G of S1 being equal to an + + align:start position:0% +the angle of G of S1 being equal to an + + + align:start position:0% +the angle of G of S1 being equal to an +odd multiple of 1880 de where we + + align:start position:0% +odd multiple of 1880 de where we + + + align:start position:0% +odd multiple of 1880 de where we +recognize in this expression n as an + + align:start position:0% +recognize in this expression n as an + + + align:start position:0% +recognize in this expression n as an +integer + + align:start position:0% + + + + align:start position:0% + +just to refresh your memory recall that + + align:start position:0% +just to refresh your memory recall that + + + align:start position:0% +just to refresh your memory recall that +if we go into the S plane and want to + + align:start position:0% +if we go into the S plane and want to + + + align:start position:0% +if we go into the S plane and want to +evaluate the Val a function of s at some + + align:start position:0% +evaluate the Val a function of s at some + + + align:start position:0% +evaluate the Val a function of s at some +point in the S plane suppose this is the + + align:start position:0% +point in the S plane suppose this is the + + + align:start position:0% +point in the S plane suppose this is the +point of Interest + + align:start position:0% +point of Interest + + + align:start position:0% +point of Interest +S1 and we're trying to check and see if + + align:start position:0% +S1 and we're trying to check and see if + + + align:start position:0% +S1 and we're trying to check and see if +that point S1 in fact satisfies the + + align:start position:0% +that point S1 in fact satisfies the + + + align:start position:0% +that point S1 in fact satisfies the +conditions for being a pole of capital A + + align:start position:0% +conditions for being a pole of capital A + + + align:start position:0% +conditions for being a pole of capital A +of s we can do the following we draw + + align:start position:0% +of s we can do the following we draw + + + align:start position:0% +of s we can do the following we draw +vectors from the poles and + + align:start position:0% +vectors from the poles and + + + align:start position:0% +vectors from the poles and +Zer of the AF + + align:start position:0% +Zer of the AF + + + align:start position:0% +Zer of the AF +product or of the G product to the point + + align:start position:0% +product or of the G product to the point + + + align:start position:0% +product or of the G product to the point +in question here we have + + align:start position:0% +in question here we have + + + align:start position:0% +in question here we have +shown one real axis pole of G ofs uh two + + align:start position:0% +shown one real axis pole of G ofs uh two + + + align:start position:0% +shown one real axis pole of G ofs uh two +complex conjugate a complex conjugate + + align:start position:0% +complex conjugate a complex conjugate + + + align:start position:0% +complex conjugate a complex conjugate +pole pair of G ofs and a single zero of + + align:start position:0% +pole pair of G ofs and a single zero of + + + align:start position:0% +pole pair of G ofs and a single zero of +G ofs if we now try to evaluate G of s + + align:start position:0% +G ofs if we now try to evaluate G of s + + + align:start position:0% +G ofs if we now try to evaluate G of s +at the point S1 what we do is draw + + align:start position:0% +at the point S1 what we do is draw + + + align:start position:0% +at the point S1 what we do is draw +vectors from the poles and the zero + + align:start position:0% +vectors from the poles and the zero + + + align:start position:0% +vectors from the poles and the zero +of G of s to the point S1 and I've + + align:start position:0% +of G of s to the point S1 and I've + + + align:start position:0% +of G of s to the point S1 and I've +showed that for the three + + align:start position:0% +showed that for the three + + + align:start position:0% +showed that for the three +poles and for the + + align:start position:0% +poles and for the + + + align:start position:0% +poles and for the +zero and we can evaluate the angle and + + align:start position:0% +zero and we can evaluate the angle and + + + align:start position:0% +zero and we can evaluate the angle and +the magnitude associated with those + + align:start position:0% +the magnitude associated with those + + + align:start position:0% +the magnitude associated with those +vectors in particular let's call this + + align:start position:0% +vectors in particular let's call this + + + align:start position:0% +vectors in particular let's call this +angle Theta + + align:start position:0% + + + + align:start position:0% + +1 and similarly the length of this + + align:start position:0% +1 and similarly the length of this + + + align:start position:0% +1 and similarly the length of this +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +L1 and let's call this this angle Theta + + align:start position:0% + + + + align:start position:0% + +2 and let's call this + + align:start position:0% + + + + align:start position:0% + +angle theta + + align:start position:0% +angle theta + + + align:start position:0% +angle theta +3 and let's call this angle Theta 4 and + + align:start position:0% +3 and let's call this angle Theta 4 and + + + align:start position:0% +3 and let's call this angle Theta 4 and +recall that this angle we + + align:start position:0% +recall that this angle we + + + align:start position:0% +recall that this angle we +evaluate like + + align:start position:0% +evaluate like + + + align:start position:0% +evaluate like +this so Theta 4 is a an angle greater + + align:start position:0% +this so Theta 4 is a an angle greater + + + align:start position:0% +this so Theta 4 is a an angle greater +actually than 270 degrees as I've shown + + align:start position:0% +actually than 270 degrees as I've shown + + + align:start position:0% +actually than 270 degrees as I've shown +it similarly let's remember that the + + align:start position:0% +it similarly let's remember that the + + + align:start position:0% +it similarly let's remember that the +lengths of the other vectors are L2 L3 + + align:start position:0% +lengths of the other vectors are L2 L3 + + + align:start position:0% +lengths of the other vectors are L2 L3 +in here and L4 for the fourth + + align:start position:0% +in here and L4 for the fourth + + + align:start position:0% +in here and L4 for the fourth +vector and we can then evaluate the + + align:start position:0% +vector and we can then evaluate the + + + align:start position:0% +vector and we can then evaluate the +angle of G of + + align:start position:0% +angle of G of + + + align:start position:0% +angle of G of +s for values of s equal to + + align:start position:0% +s for values of s equal to + + + align:start position:0% +s for values of s equal to +S1 as being equal simply to the sum of + + align:start position:0% +S1 as being equal simply to the sum of + + + align:start position:0% +S1 as being equal simply to the sum of +all the angles associated with the + + align:start position:0% +all the angles associated with the + + + align:start position:0% +all the angles associated with the +vectors from Zer in this case we only + + align:start position:0% +vectors from Zer in this case we only + + + align:start position:0% +vectors from Zer in this case we only +have one of them so that's Theta 1 and + + align:start position:0% +have one of them so that's Theta 1 and + + + align:start position:0% +have one of them so that's Theta 1 and +we subtract from that sum the angles + + align:start position:0% +we subtract from that sum the angles + + + align:start position:0% +we subtract from that sum the angles +associated with the vectors from all of + + align:start position:0% +associated with the vectors from all of + + + align:start position:0% +associated with the vectors from all of +the poles of the function in particular + + align:start position:0% +the poles of the function in particular + + + align:start position:0% +the poles of the function in particular +in our case minus Theta 2 minus theta 3 + + align:start position:0% +in our case minus Theta 2 minus theta 3 + + + align:start position:0% +in our case minus Theta 2 minus theta 3 +minus Theta 4 since those are the angles + + align:start position:0% +minus Theta 4 since those are the angles + + + align:start position:0% +minus Theta 4 since those are the angles +associated with the three poles of G of + + align:start position:0% +associated with the three poles of G of + + + align:start position:0% +associated with the three poles of G of +s similarly the magnitude of our + + align:start position:0% +s similarly the magnitude of our + + + align:start position:0% +s similarly the magnitude of our +transfer function is within a constant + + align:start position:0% +transfer function is within a constant + + + align:start position:0% +transfer function is within a constant +of + + align:start position:0% +of + + + align:start position:0% +of +proportionality equal to the product of + + align:start position:0% +proportionality equal to the product of + + + align:start position:0% +proportionality equal to the product of +the lengths of the vectors from all of + + align:start position:0% +the lengths of the vectors from all of + + + align:start position:0% +the lengths of the vectors from all of +the zeros to the point in question + + align:start position:0% +the zeros to the point in question + + + align:start position:0% +the zeros to the point in question +question in our system again we have + + align:start position:0% +question in our system again we have + + + align:start position:0% +question in our system again we have +only one zero so that's L1 divided by + + align:start position:0% +only one zero so that's L1 divided by + + + align:start position:0% +only one zero so that's L1 divided by +the product of the lengths of the + + align:start position:0% +the product of the lengths of the + + + align:start position:0% +the product of the lengths of the +vectors from all the PO poles of the + + align:start position:0% +vectors from all the PO poles of the + + + align:start position:0% +vectors from all the PO poles of the +transfer function to the point in + + align:start position:0% +transfer function to the point in + + + align:start position:0% +transfer function to the point in +question so in our case with three poles + + align:start position:0% +question so in our case with three poles + + + align:start position:0% +question so in our case with three poles +we have the product L2 * L3 * + + align:start position:0% +we have the product L2 * L3 * + + + align:start position:0% +we have the product L2 * L3 * +L4 well all we have to do then if we are + + align:start position:0% +L4 well all we have to do then if we are + + + align:start position:0% +L4 well all we have to do then if we are +interested in finding out whether a + + align:start position:0% +interested in finding out whether a + + + align:start position:0% +interested in finding out whether a +particular Point S1 in fact corresponds + + align:start position:0% +particular Point S1 in fact corresponds + + + align:start position:0% +particular Point S1 in fact corresponds +to a closed loop pole of capital A of s + + align:start position:0% +to a closed loop pole of capital A of s + + + align:start position:0% +to a closed loop pole of capital A of s +is to evaluate the function G of of S1 + + align:start position:0% +is to evaluate the function G of of S1 + + + align:start position:0% +is to evaluate the function G of of S1 +or in particular a f time G of S1 and + + align:start position:0% +or in particular a f time G of S1 and + + + align:start position:0% +or in particular a f time G of S1 and +see if that product is equal to + + align:start position:0% +see if that product is equal to + + + align:start position:0% +see if that product is equal to +minus1 usually the most powerful test + + align:start position:0% +minus1 usually the most powerful test + + + align:start position:0% +minus1 usually the most powerful test +involves the angle condition remember + + align:start position:0% +involves the angle condition remember + + + align:start position:0% +involves the angle condition remember +that we're going to construct a root + + align:start position:0% +that we're going to construct a root + + + align:start position:0% +that we're going to construct a root +Locus diagram starting with the poles + + align:start position:0% +Locus diagram starting with the poles + + + align:start position:0% +Locus diagram starting with the poles +and zeros of the loop + + align:start position:0% +and zeros of the loop + + + align:start position:0% +and zeros of the loop +transmission and then find out how the + + align:start position:0% +transmission and then find out how the + + + align:start position:0% +transmission and then find out how the +closed loop poles change location as a + + align:start position:0% +closed loop poles change location as a + + + align:start position:0% +closed loop poles change location as a +function of a fnot as a function of the + + align:start position:0% +function of a fnot as a function of the + + + align:start position:0% +function of a fnot as a function of the +DC magnitude of the loop + + align:start position:0% +DC magnitude of the loop + + + align:start position:0% +DC magnitude of the loop +transmission since we're constructing + + align:start position:0% +transmission since we're constructing + + + align:start position:0% +transmission since we're constructing +our root Locus diagram as a function of + + align:start position:0% +our root Locus diagram as a function of + + + align:start position:0% +our root Locus diagram as a function of +a FN we can always find a value of a KN + + align:start position:0% +a FN we can always find a value of a KN + + + align:start position:0% +a FN we can always find a value of a KN +FN which will make the magnitude + + align:start position:0% +FN which will make the magnitude + + + align:start position:0% +FN which will make the magnitude +condition be satisfied consequently the + + align:start position:0% +condition be satisfied consequently the + + + align:start position:0% +condition be satisfied consequently the +uh part of this development that really + + align:start position:0% +uh part of this development that really + + + align:start position:0% +uh part of this development that really +gives us Leverage is the angle condition + + align:start position:0% +gives us Leverage is the angle condition + + + align:start position:0% +gives us Leverage is the angle condition +and so what we ought to do as a general + + align:start position:0% +and so what we ought to do as a general + + + align:start position:0% +and so what we ought to do as a general +test + + align:start position:0% +test + + + align:start position:0% +test +is look in the S plane for points where + + align:start position:0% +is look in the S plane for points where + + + align:start position:0% +is look in the S plane for points where +the angle condition is satisfied in + + align:start position:0% +the angle condition is satisfied in + + + align:start position:0% +the angle condition is satisfied in +other words where for points where G of + + align:start position:0% +other words where for points where G of + + + align:start position:0% +other words where for points where G of +s has an angle that's equal to an odd + + align:start position:0% +s has an angle that's equal to an odd + + + align:start position:0% +s has an angle that's equal to an odd +multiple of + + align:start position:0% + + + + align:start position:0% + +180° that condition has been exploited + + align:start position:0% +180° that condition has been exploited + + + align:start position:0% +180° that condition has been exploited +to develop a number of rules that help + + align:start position:0% +to develop a number of rules that help + + + align:start position:0% +to develop a number of rules that help +us sketch rapidly and and accurately the + + align:start position:0% +us sketch rapidly and and accurately the + + + align:start position:0% +us sketch rapidly and and accurately the +root Locust diagram for a system I'd + + align:start position:0% +root Locust diagram for a system I'd + + + align:start position:0% +root Locust diagram for a system I'd +like to point out at the outset that + + align:start position:0% +like to point out at the outset that + + + align:start position:0% +like to point out at the outset that +there's little universality among + + align:start position:0% +there's little universality among + + + align:start position:0% +there's little universality among +authors and and on the on the specifics + + align:start position:0% +authors and and on the on the specifics + + + align:start position:0% +authors and and on the on the specifics +of these rules some people feel that + + align:start position:0% +of these rules some people feel that + + + align:start position:0% +of these rules some people feel that +there are a greater number of them + + align:start position:0% +there are a greater number of them + + + align:start position:0% +there are a greater number of them +required others feel there's there are + + align:start position:0% +required others feel there's there are + + + align:start position:0% +required others feel there's there are +fewer I've seen some developments that + + align:start position:0% +fewer I've seen some developments that + + + align:start position:0% +fewer I've seen some developments that +state only three or four rules I've seen + + align:start position:0% +state only three or four rules I've seen + + + align:start position:0% +state only three or four rules I've seen +other developments where there are as + + align:start position:0% +other developments where there are as + + + align:start position:0% +other developments where there are as +many as 15 rules drawn out and I happen + + align:start position:0% +many as 15 rules drawn out and I happen + + + align:start position:0% +many as 15 rules drawn out and I happen +to have chosen eight which are my own + + align:start position:0% +to have chosen eight which are my own + + + align:start position:0% +to have chosen eight which are my own +favorites and I feel that that they give + + align:start position:0% +favorites and I feel that that they give + + + align:start position:0% +favorites and I feel that that they give +us a good handle on quickly constructing + + align:start position:0% +us a good handle on quickly constructing + + + align:start position:0% +us a good handle on quickly constructing +a root Locust diagram but again I + + align:start position:0% +a root Locust diagram but again I + + + align:start position:0% +a root Locust diagram but again I +emphasize that you can velop rules of + + align:start position:0% +emphasize that you can velop rules of + + + align:start position:0% +emphasize that you can velop rules of +your own by going back to our real + + align:start position:0% +your own by going back to our real + + + align:start position:0% +your own by going back to our real +consideration which is that the a fot G + + align:start position:0% +consideration which is that the a fot G + + + align:start position:0% +consideration which is that the a fot G +ofs product has to be equal to minus one + + align:start position:0% +ofs product has to be equal to minus one + + + align:start position:0% +ofs product has to be equal to minus one +at a pole of capital A of + + align:start position:0% +at a pole of capital A of + + + align:start position:0% +at a pole of capital A of +s the rules are given in considerable + + align:start position:0% +s the rules are given in considerable + + + align:start position:0% +s the rules are given in considerable +detail in the text and I haven't written + + align:start position:0% +detail in the text and I haven't written + + + align:start position:0% +detail in the text and I haven't written +them out in that sort of detail here but + + align:start position:0% +them out in that sort of detail here but + + + align:start position:0% +them out in that sort of detail here but +what I'd like to do is explain the rules + + align:start position:0% +what I'd like to do is explain the rules + + + align:start position:0% +what I'd like to do is explain the rules +you can read them at your leisure and + + align:start position:0% +you can read them at your leisure and + + + align:start position:0% +you can read them at your leisure and +then also illustrate the ones that we've + + align:start position:0% +then also illustrate the ones that we've + + + align:start position:0% +then also illustrate the ones that we've +already seen in our second order system + + align:start position:0% +already seen in our second order system + + + align:start position:0% +already seen in our second order system +the first rule involves the number of + + align:start position:0% +the first rule involves the number of + + + align:start position:0% +the first rule involves the number of +branches and in particular the number of + + align:start position:0% +branches and in particular the number of + + + align:start position:0% +branches and in particular the number of +branches in a root Locus diagram is + + align:start position:0% +branches in a root Locus diagram is + + + align:start position:0% +branches in a root Locus diagram is +equal to the number of poles of capital + + align:start position:0% +equal to the number of poles of capital + + + align:start position:0% +equal to the number of poles of capital +of of the loop transmission the number + + align:start position:0% +of of the loop transmission the number + + + align:start position:0% +of of the loop transmission the number +of poles of the AF + + align:start position:0% +of poles of the AF + + + align:start position:0% +of poles of the AF +product that's simply a statement of the + + align:start position:0% +product that's simply a statement of the + + + align:start position:0% +product that's simply a statement of the +fact that feedback doesn't add any modes + + align:start position:0% +fact that feedback doesn't add any modes + + + align:start position:0% +fact that feedback doesn't add any modes +of energy storage to the system and so + + align:start position:0% +of energy storage to the system and so + + + align:start position:0% +of energy storage to the system and so +if we have three poles in the Loop + + align:start position:0% +if we have three poles in the Loop + + + align:start position:0% +if we have three poles in the Loop +transmission if we have three + + align:start position:0% +transmission if we have three + + + align:start position:0% +transmission if we have three +independent methods of energy storage in + + align:start position:0% +independent methods of energy storage in + + + align:start position:0% +independent methods of energy storage in +the system then in fact all closed loop + + align:start position:0% +the system then in fact all closed loop + + + align:start position:0% +the system then in fact all closed loop +transfer functions also have those three + + align:start position:0% +transfer functions also have those three + + + align:start position:0% +transfer functions also have those three +modes of energy + + align:start position:0% +modes of energy + + + align:start position:0% +modes of energy +storage the second part of rule one + + align:start position:0% +storage the second part of rule one + + + align:start position:0% +storage the second part of rule one +involves the location of the closed loop + + align:start position:0% +involves the location of the closed loop + + + align:start position:0% +involves the location of the closed loop +roots or the closed loop poles for very + + align:start position:0% +roots or the closed loop poles for very + + + align:start position:0% +roots or the closed loop poles for very +large and for very small values of the a + + align:start position:0% +large and for very small values of the a + + + align:start position:0% +large and for very small values of the a +FN product in particular satisfaction of + + align:start position:0% +FN product in particular satisfaction of + + + align:start position:0% +FN product in particular satisfaction of +the magnitude condition this becomes a + + align:start position:0% +the magnitude condition this becomes a + + + align:start position:0% +the magnitude condition this becomes a +little embarrassing since I had + + align:start position:0% +little embarrassing since I had + + + align:start position:0% +little embarrassing since I had +mentioned that the real leverage comes + + align:start position:0% +mentioned that the real leverage comes + + + align:start position:0% +mentioned that the real leverage comes +out of the angle condition and + + align:start position:0% +out of the angle condition and + + + align:start position:0% +out of the angle condition and +unfortunately the first rule is really + + align:start position:0% +unfortunately the first rule is really + + + align:start position:0% +unfortunately the first rule is really +proved using the magnitude condition if + + align:start position:0% +proved using the magnitude condition if + + + align:start position:0% +proved using the magnitude condition if +we rearrange the magnitude condition the + + align:start position:0% +we rearrange the magnitude condition the + + + align:start position:0% +we rearrange the magnitude condition the +magnitude of G of s must be equal to one + + align:start position:0% +magnitude of G of s must be equal to one + + + align:start position:0% +magnitude of G of s must be equal to one +over the a FN product in order to be at + + align:start position:0% +over the a FN product in order to be at + + + align:start position:0% +over the a FN product in order to be at +a point which is a closed loop pole of + + align:start position:0% +a point which is a closed loop pole of + + + align:start position:0% +a point which is a closed loop pole of +capital + + align:start position:0% +capital + + + align:start position:0% +capital +a uh suppose we have a very very small a + + align:start position:0% +a uh suppose we have a very very small a + + + align:start position:0% +a uh suppose we have a very very small a +FN product in order to satisfy the + + align:start position:0% +FN product in order to satisfy the + + + align:start position:0% +FN product in order to satisfy the +magnitude condition + + align:start position:0% +magnitude condition + + + align:start position:0% +magnitude condition +G of s must be very very large in other + + align:start position:0% +G of s must be very very large in other + + + align:start position:0% +G of s must be very very large in other +words we have to be very close to a pole + + align:start position:0% +words we have to be very close to a pole + + + align:start position:0% +words we have to be very close to a pole +of G of s or correspondingly to a pole + + align:start position:0% +of G of s or correspondingly to a pole + + + align:start position:0% +of G of s or correspondingly to a pole +of the loop transmission so our branches + + align:start position:0% +of the loop transmission so our branches + + + align:start position:0% +of the loop transmission so our branches +the branches of our root Locus diagram + + align:start position:0% +the branches of our root Locus diagram + + + align:start position:0% +the branches of our root Locus diagram +start at the poles of the loop + + align:start position:0% +start at the poles of the loop + + + align:start position:0% +start at the poles of the loop +transmission similarly when we have very + + align:start position:0% +transmission similarly when we have very + + + align:start position:0% +transmission similarly when we have very +large values of a + + align:start position:0% +large values of a + + + align:start position:0% +large values of a +f uh let's see for a f not very large + + align:start position:0% +f uh let's see for a f not very large + + + align:start position:0% +f uh let's see for a f not very large +the magnitude of G of s has to be very + + align:start position:0% +the magnitude of G of s has to be very + + + align:start position:0% +the magnitude of G of s has to be very +small in other words we have to be close + + align:start position:0% +small in other words we have to be close + + + align:start position:0% +small in other words we have to be close +to a zero of G of s so the branches + + align:start position:0% +to a zero of G of s so the branches + + + align:start position:0% +to a zero of G of s so the branches +start at poles of the loop transmission + + align:start position:0% +start at poles of the loop transmission + + + align:start position:0% +start at poles of the loop transmission +and end at zeros of the loop + + align:start position:0% +and end at zeros of the loop + + + align:start position:0% +and end at zeros of the loop +transmission where starting and ending + + align:start position:0% +transmission where starting and ending + + + align:start position:0% +transmission where starting and ending +are defined respectively by small values + + align:start position:0% +are defined respectively by small values + + + align:start position:0% +are defined respectively by small values +of a FN and large values of a + + align:start position:0% +of a FN and large values of a + + + align:start position:0% +of a FN and large values of a +FN we've seen that + + align:start position:0% +FN we've seen that + + + align:start position:0% +FN we've seen that +behavior in our second order system uh + + align:start position:0% +behavior in our second order system uh + + + align:start position:0% +behavior in our second order system uh +recall here we had Loop transmission + + align:start position:0% +recall here we had Loop transmission + + + align:start position:0% +recall here we had Loop transmission +poles at the two x locations we used + + align:start position:0% +poles at the two x locations we used + + + align:start position:0% +poles at the two x locations we used +usually indicate Loop transmission poles + + align:start position:0% +usually indicate Loop transmission poles + + + align:start position:0% +usually indicate Loop transmission poles +and zeros for reference points in our + + align:start position:0% +and zeros for reference points in our + + + align:start position:0% +and zeros for reference points in our +root Locus diagram and recall that the + + align:start position:0% +root Locus diagram and recall that the + + + align:start position:0% +root Locus diagram and recall that the +closed loop pole started at this + + align:start position:0% +closed loop pole started at this + + + align:start position:0% +closed loop pole started at this +location for vanishingly small values of + + align:start position:0% +location for vanishingly small values of + + + align:start position:0% +location for vanishingly small values of +a FN and then as a FN got very + + align:start position:0% +a FN and then as a FN got very + + + align:start position:0% +a FN and then as a FN got very +large why the poles went off as or the + + align:start position:0% +large why the poles went off as or the + + + align:start position:0% +large why the poles went off as or the +branches the closed loop poles left the + + align:start position:0% +branches the closed loop poles left the + + + align:start position:0% +branches the closed loop poles left the +S plane as shown well our statement of + + align:start position:0% +S plane as shown well our statement of + + + align:start position:0% +S plane as shown well our statement of +rule one says that they end up the + + align:start position:0% +rule one says that they end up the + + + align:start position:0% +rule one says that they end up the +branches must terminate at zeros for + + align:start position:0% +branches must terminate at zeros for + + + align:start position:0% +branches must terminate at zeros for +very large values of of the AF product + + align:start position:0% +very large values of of the AF product + + + align:start position:0% +very large values of of the AF product +or of a f and here in fact we have a + + align:start position:0% +or of a f and here in fact we have a + + + align:start position:0% +or of a f and here in fact we have a +second order Loop Transmission in other + + align:start position:0% +second order Loop Transmission in other + + + align:start position:0% +second order Loop Transmission in other +words the denominator polinomial is + + align:start position:0% +words the denominator polinomial is + + + align:start position:0% +words the denominator polinomial is +second order in + + align:start position:0% +second order in + + + align:start position:0% +second order in +s and that function goes to zero or the + + align:start position:0% +s and that function goes to zero or the + + + align:start position:0% +s and that function goes to zero or the +the loop transmission goes to zero for + + align:start position:0% +the loop transmission goes to zero for + + + align:start position:0% +the loop transmission goes to zero for +very large values of s and in fact it + + align:start position:0% +very large values of s and in fact it + + + align:start position:0% +very large values of s and in fact it +goes to zero for large values of s as s^ + + align:start position:0% +goes to zero for large values of s as s^ + + + align:start position:0% +goes to zero for large values of s as s^ +s in other words our Loop Transmission + + align:start position:0% +s in other words our Loop Transmission + + + align:start position:0% +s in other words our Loop Transmission +in addition to having two poles at S = + + align:start position:0% +in addition to having two poles at S = + + + align:start position:0% +in addition to having two poles at S = +-1/ T A and S Min - one over T B has two + + align:start position:0% +-1/ T A and S Min - one over T B has two + + + align:start position:0% +-1/ T A and S Min - one over T B has two +zeros at + + align:start position:0% +zeros at + + + align:start position:0% +zeros at +infinity and so uh in this case the + + align:start position:0% +infinity and so uh in this case the + + + align:start position:0% +infinity and so uh in this case the +branches leave the S plane we can + + align:start position:0% +branches leave the S plane we can + + + align:start position:0% +branches leave the S plane we can +consider that as really terminating on + + align:start position:0% +consider that as really terminating on + + + align:start position:0% +consider that as really terminating on +zeros of the loop transmission which + + align:start position:0% +zeros of the loop transmission which + + + align:start position:0% +zeros of the loop transmission which +happen to be located at Infinity one of + + align:start position:0% +happen to be located at Infinity one of + + + align:start position:0% +happen to be located at Infinity one of +the rules that we'll get later on + + align:start position:0% +the rules that we'll get later on + + + align:start position:0% +the rules that we'll get later on +effectively tells us what direction is + + align:start position:0% +effectively tells us what direction is + + + align:start position:0% +effectively tells us what direction is +infinity for a specific Loop + + align:start position:0% +infinity for a specific Loop + + + align:start position:0% +infinity for a specific Loop +transmission that's another important + + align:start position:0% + + + + align:start position:0% + +Point rule two deals with the behavior + + align:start position:0% +Point rule two deals with the behavior + + + align:start position:0% +Point rule two deals with the behavior +on the real + + align:start position:0% +on the real + + + align:start position:0% +on the real +axis and what I've shown here is an S + + align:start position:0% +axis and what I've shown here is an S + + + align:start position:0% +axis and what I've shown here is an S +plane + + align:start position:0% + + + + align:start position:0% + +diagram suppose we're concerned with the + + align:start position:0% +diagram suppose we're concerned with the + + + align:start position:0% +diagram suppose we're concerned with the +portions of the real axis where branches + + align:start position:0% +portions of the real axis where branches + + + align:start position:0% +portions of the real axis where branches +of the root Locus diagram can exist and + + align:start position:0% +of the root Locus diagram can exist and + + + align:start position:0% +of the root Locus diagram can exist and +in fact must exist suppose we'd like to + + align:start position:0% +in fact must exist suppose we'd like to + + + align:start position:0% +in fact must exist suppose we'd like to +test some part of the real axis possibly + + align:start position:0% +test some part of the real axis possibly + + + align:start position:0% +test some part of the real axis possibly +here to see if that's a possible + + align:start position:0% +here to see if that's a possible + + + align:start position:0% +here to see if that's a possible +location for a branch of the root Locus + + align:start position:0% +location for a branch of the root Locus + + + align:start position:0% +location for a branch of the root Locus +diagram we evaluate the angle of the + + align:start position:0% +diagram we evaluate the angle of the + + + align:start position:0% +diagram we evaluate the angle of the +loop transmission or the angle of G of s + + align:start position:0% +loop transmission or the angle of G of s + + + align:start position:0% +loop transmission or the angle of G of s +at that point and of course we've + + align:start position:0% +at that point and of course we've + + + align:start position:0% +at that point and of course we've +assumed that I have show I'm showing in + + align:start position:0% +assumed that I have show I'm showing in + + + align:start position:0% +assumed that I have show I'm showing in +the diagram the poles and the zeros of G + + align:start position:0% +the diagram the poles and the zeros of G + + + align:start position:0% +the diagram the poles and the zeros of G +of + + align:start position:0% +of + + + align:start position:0% +of +s and when I evaluate the angle of this + + align:start position:0% +s and when I evaluate the angle of this + + + align:start position:0% +s and when I evaluate the angle of this +function I of course draw vectors from + + align:start position:0% +function I of course draw vectors from + + + align:start position:0% +function I of course draw vectors from +the poles and the zeros to the point in + + align:start position:0% +the poles and the zeros to the point in + + + align:start position:0% +the poles and the zeros to the point in +question and let's see for every real + + align:start position:0% +question and let's see for every real + + + align:start position:0% +question and let's see for every real +axis Pole or zero to my right I get a + + align:start position:0% +axis Pole or zero to my right I get a + + + align:start position:0% +axis Pole or zero to my right I get a +net 180° the angle of a vector from this + + align:start position:0% +net 180° the angle of a vector from this + + + align:start position:0% +net 180° the angle of a vector from this +zero to this point is 180° similarly the + + align:start position:0% +zero to this point is 180° similarly the + + + align:start position:0% +zero to this point is 180° similarly the +angle of of a vector from this pole to + + align:start position:0% +angle of of a vector from this pole to + + + align:start position:0% +angle of of a vector from this pole to +this point is minus 180 degre or the net + + align:start position:0% +this point is minus 180 degre or the net + + + align:start position:0% +this point is minus 180 degre or the net +angle since that's a denominator term uh + + align:start position:0% +angle since that's a denominator term uh + + + align:start position:0% +angle since that's a denominator term uh +but every real axis Pole or zero to my + + align:start position:0% +but every real axis Pole or zero to my + + + align:start position:0% +but every real axis Pole or zero to my +right contributes a net 180 + + align:start position:0% +right contributes a net 180 + + + align:start position:0% +right contributes a net 180 +de real axis poles or zeros to the left + + align:start position:0% +de real axis poles or zeros to the left + + + align:start position:0% +de real axis poles or zeros to the left +of the point in question contribute + + align:start position:0% +of the point in question contribute + + + align:start position:0% +of the point in question contribute +nothing to the angle when I draw a + + align:start position:0% +nothing to the angle when I draw a + + + align:start position:0% +nothing to the angle when I draw a +vector from this pole for example to + + align:start position:0% +vector from this pole for example to + + + align:start position:0% +vector from this pole for example to +this point why the angle associated with + + align:start position:0% +this point why the angle associated with + + + align:start position:0% +this point why the angle associated with +that Vector is zero similarly complex + + align:start position:0% +that Vector is zero similarly complex + + + align:start position:0% +that Vector is zero similarly complex +conjugate poles or zeros have angles + + align:start position:0% +conjugate poles or zeros have angles + + + align:start position:0% +conjugate poles or zeros have angles +which sum to a multiple of + + align:start position:0% +which sum to a multiple of + + + align:start position:0% +which sum to a multiple of +360° a given complex conjugate pair has + + align:start position:0% +360° a given complex conjugate pair has + + + align:start position:0% +360° a given complex conjugate pair has +an angle which sums to precisely 360° + + align:start position:0% +an angle which sums to precisely 360° + + + align:start position:0% +an angle which sums to precisely 360° +consider the contribution from this + + align:start position:0% +consider the contribution from this + + + align:start position:0% +consider the contribution from this +complex conjugate zero + + align:start position:0% + + + + align:start position:0% + +pair this + + align:start position:0% + + + + align:start position:0% + +angle + + align:start position:0% +angle + + + align:start position:0% +angle +plus this angle sum to + + align:start position:0% + + + + align:start position:0% + +360° well fine the condition then is + + align:start position:0% +360° well fine the condition then is + + + align:start position:0% +360° well fine the condition then is +simply that in order to have an odd + + align:start position:0% +simply that in order to have an odd + + + align:start position:0% +simply that in order to have an odd +multiple of 180 degrees in other words + + align:start position:0% +multiple of 180 degrees in other words + + + align:start position:0% +multiple of 180 degrees in other words +to have a minus sign associated with G + + align:start position:0% +to have a minus sign associated with G + + + align:start position:0% +to have a minus sign associated with G +of s we must have an OD number of poles + + align:start position:0% +of s we must have an OD number of poles + + + align:start position:0% +of s we must have an OD number of poles +and Zer to the right of us on the real + + align:start position:0% +and Zer to the right of us on the real + + + align:start position:0% +and Zer to the right of us on the real +axis since each one of those poles and + + align:start position:0% +axis since each one of those poles and + + + align:start position:0% +axis since each one of those poles and +zeros contributes a net 180° to the + + align:start position:0% +zeros contributes a net 180° to the + + + align:start position:0% +zeros contributes a net 180° to the +angle of G of s consequently the only + + align:start position:0% +angle of G of s consequently the only + + + align:start position:0% +angle of G of s consequently the only +way we can have an odd multiple of 180 + + align:start position:0% +way we can have an odd multiple of 180 + + + align:start position:0% +way we can have an odd multiple of 180 +Dees is to have an odd number of poles + + align:start position:0% +Dees is to have an odd number of poles + + + align:start position:0% +Dees is to have an odd number of poles +and zeros to our right and so in this + + align:start position:0% +and zeros to our right and so in this + + + align:start position:0% +and zeros to our right and so in this +particular situation for this + + align:start position:0% +particular situation for this + + + align:start position:0% +particular situation for this +particular pole and + + align:start position:0% +particular pole and + + + align:start position:0% +particular pole and +zero configuration of G of s this this + + align:start position:0% +zero configuration of G of s this this + + + align:start position:0% +zero configuration of G of s this this +portion of the real axis will have + + align:start position:0% +portion of the real axis will have + + + align:start position:0% +portion of the real axis will have +branches there are three poles and zeros + + align:start position:0% +branches there are three poles and zeros + + + align:start position:0% +branches there are three poles and zeros +to our right similarly this + + align:start position:0% +to our right similarly this + + + align:start position:0% +to our right similarly this +portion will have a branch or branches + + align:start position:0% +portion will have a branch or branches + + + align:start position:0% +portion will have a branch or branches +there are again uh one an odd number of + + align:start position:0% +there are again uh one an odd number of + + + align:start position:0% +there are again uh one an odd number of +zeros in this case to our + + align:start position:0% +zeros in this case to our + + + align:start position:0% +zeros in this case to our +right rule three deals with the behavior + + align:start position:0% +right rule three deals with the behavior + + + align:start position:0% +right rule three deals with the behavior +on portions of the real axis where the + + align:start position:0% +on portions of the real axis where the + + + align:start position:0% +on portions of the real axis where the +branches exist we've determined Those + + align:start position:0% +branches exist we've determined Those + + + align:start position:0% +branches exist we've determined Those +portions from rule two and if in fact + + align:start position:0% +portions from rule two and if in fact + + + align:start position:0% +portions from rule two and if in fact +there are portions of the real axis + + align:start position:0% +there are portions of the real axis + + + align:start position:0% +there are portions of the real axis +between either two pairs of poles we saw + + align:start position:0% +between either two pairs of poles we saw + + + align:start position:0% +between either two pairs of poles we saw +an example of that when we were + + align:start position:0% +an example of that when we were + + + align:start position:0% +an example of that when we were +discussing rule two or between two + + align:start position:0% +discussing rule two or between two + + + align:start position:0% +discussing rule two or between two +zeros why there have to be two separate + + align:start position:0% +zeros why there have to be two separate + + + align:start position:0% +zeros why there have to be two separate +branches in those locations in other + + align:start position:0% +branches in those locations in other + + + align:start position:0% +branches in those locations in other +words we've said that branches start at + + align:start position:0% +words we've said that branches start at + + + align:start position:0% +words we've said that branches start at +poles of the loop transmission and + + align:start position:0% +poles of the loop transmission and + + + align:start position:0% +poles of the loop transmission and +consequently if there are two poles and + + align:start position:0% +consequently if there are two poles and + + + align:start position:0% +consequently if there are two poles and +if the real axis between them as here uh + + align:start position:0% +if the real axis between them as here uh + + + align:start position:0% +if the real axis between them as here uh +has branches on it there must be two + + align:start position:0% +has branches on it there must be two + + + align:start position:0% +has branches on it there must be two +branches and the only thing that can + + align:start position:0% +branches and the only thing that can + + + align:start position:0% +branches and the only thing that can +happen as a FN increases these branches + + align:start position:0% +happen as a FN increases these branches + + + align:start position:0% +happen as a FN increases these branches +recall start at the poles of G ofs or + + align:start position:0% +recall start at the poles of G ofs or + + + align:start position:0% +recall start at the poles of G ofs or +the poles of the loop transmission for + + align:start position:0% +the poles of the loop transmission for + + + align:start position:0% +the poles of the loop transmission for +small values of a f as we increase a FN + + align:start position:0% +small values of a f as we increase a FN + + + align:start position:0% +small values of a f as we increase a FN +the two branches come together but they + + align:start position:0% +the two branches come together but they + + + align:start position:0% +the two branches come together but they +must eventually leave the real axis so + + align:start position:0% +must eventually leave the real axis so + + + align:start position:0% +must eventually leave the real axis so +that they can reach zeros somewhere and + + align:start position:0% +that they can reach zeros somewhere and + + + align:start position:0% +that they can reach zeros somewhere and +consequently they must break away from + + align:start position:0% +consequently they must break away from + + + align:start position:0% +consequently they must break away from +the real axis at some point between the + + align:start position:0% +the real axis at some point between the + + + align:start position:0% +the real axis at some point between the +two poles similarly if there are two + + align:start position:0% +two poles similarly if there are two + + + align:start position:0% +two poles similarly if there are two +zeros surrounding a portion of the real + + align:start position:0% +zeros surrounding a portion of the real + + + align:start position:0% +zeros surrounding a portion of the real +axis where branches exist for some value + + align:start position:0% +axis where branches exist for some value + + + align:start position:0% +axis where branches exist for some value +of a FN the branches must enter the real + + align:start position:0% +of a FN the branches must enter the real + + + align:start position:0% +of a FN the branches must enter the real +axis and then head off toward those two + + align:start position:0% +axis and then head off toward those two + + + align:start position:0% +axis and then head off toward those two +zeros for larger values of a f and so + + align:start position:0% +zeros for larger values of a f and so + + + align:start position:0% +zeros for larger values of a f and so +there has to have to be either Breakaway + + align:start position:0% +there has to have to be either Breakaway + + + align:start position:0% +there has to have to be either Breakaway +points between two pairs of poles where + + align:start position:0% +points between two pairs of poles where + + + align:start position:0% +points between two pairs of poles where +branches exist or entry points to the + + align:start position:0% +branches exist or entry points to the + + + align:start position:0% +branches exist or entry points to the +real axis between two pairs of zeros + + align:start position:0% +real axis between two pairs of zeros + + + align:start position:0% +real axis between two pairs of zeros +where branches exist and we can solve + + align:start position:0% +where branches exist and we can solve + + + align:start position:0% +where branches exist and we can solve +for the location of those entry points + + align:start position:0% +for the location of those entry points + + + align:start position:0% +for the location of those entry points +by considering an equation DG of s by DS + + align:start position:0% +by considering an equation DG of s by DS + + + align:start position:0% +by considering an equation DG of s by DS +equals z let me point out that it's not + + align:start position:0% +equals z let me point out that it's not + + + align:start position:0% +equals z let me point out that it's not +always necessary to solve precisely for + + align:start position:0% +always necessary to solve precisely for + + + align:start position:0% +always necessary to solve precisely for +such entry or Breakaway points in fact + + align:start position:0% +such entry or Breakaway points in fact + + + align:start position:0% +such entry or Breakaway points in fact +my own feeling is that a very real + + align:start position:0% +my own feeling is that a very real + + + align:start position:0% +my own feeling is that a very real +benefit of a root Locus technique is + + align:start position:0% +benefit of a root Locus technique is + + + align:start position:0% +benefit of a root Locus technique is +that it gives us a way to very quickly + + align:start position:0% +that it gives us a way to very quickly + + + align:start position:0% +that it gives us a way to very quickly +sketch important features of a loop + + align:start position:0% +sketch important features of a loop + + + align:start position:0% +sketch important features of a loop +transmission or of a closed loop + + align:start position:0% +transmission or of a closed loop + + + align:start position:0% +transmission or of a closed loop +transfer function and therefore very + + align:start position:0% +transfer function and therefore very + + + align:start position:0% +transfer function and therefore very +very frequently we're not interested in + + align:start position:0% +very frequently we're not interested in + + + align:start position:0% +very frequently we're not interested in +exact numerical results we get enough + + align:start position:0% +exact numerical results we get enough + + + align:start position:0% +exact numerical results we get enough +feeling for what's going on on by by + + align:start position:0% +feeling for what's going on on by by + + + align:start position:0% +feeling for what's going on on by by +approximate techniques however if we are + + align:start position:0% +approximate techniques however if we are + + + align:start position:0% +approximate techniques however if we are +interested in getting precise numerical + + align:start position:0% +interested in getting precise numerical + + + align:start position:0% +interested in getting precise numerical +results one of the things we might need + + align:start position:0% +results one of the things we might need + + + align:start position:0% +results one of the things we might need +to know is are the Breakaway points we + + align:start position:0% +to know is are the Breakaway points we + + + align:start position:0% +to know is are the Breakaway points we +can get that from the equation that I've + + align:start position:0% +can get that from the equation that I've + + + align:start position:0% +can get that from the equation that I've +indicated again we've seen this behavior + + align:start position:0% +indicated again we've seen this behavior + + + align:start position:0% +indicated again we've seen this behavior +in our second order system notice that + + align:start position:0% +in our second order system notice that + + + align:start position:0% +in our second order system notice that +here we have uh the two branches coming + + align:start position:0% +here we have uh the two branches coming + + + align:start position:0% +here we have uh the two branches coming +together the real axis in this region + + align:start position:0% +together the real axis in this region + + + align:start position:0% +together the real axis in this region +must in fact be a possible must contain + + align:start position:0% +must in fact be a possible must contain + + + align:start position:0% +must in fact be a possible must contain +branches of of the root Locust diagram + + align:start position:0% +branches of of the root Locust diagram + + + align:start position:0% +branches of of the root Locust diagram +since there's an odd number of of poles + + align:start position:0% +since there's an odd number of of poles + + + align:start position:0% +since there's an odd number of of poles +and zeros to our right in particular + + align:start position:0% +and zeros to our right in particular + + + align:start position:0% +and zeros to our right in particular +there's one pole to our right on the + + align:start position:0% +there's one pole to our right on the + + + align:start position:0% +there's one pole to our right on the +real axis uh the two branches come + + align:start position:0% +real axis uh the two branches come + + + align:start position:0% +real axis uh the two branches come +together they break away the Breakaway + + align:start position:0% +together they break away the Breakaway + + + align:start position:0% +together they break away the Breakaway +is at right angles and that's always the + + align:start position:0% +is at right angles and that's always the + + + align:start position:0% +is at right angles and that's always the +case Breakaway or re-entry to the real + + align:start position:0% +case Breakaway or re-entry to the real + + + align:start position:0% +case Breakaway or re-entry to the real +axis is always at right angles to the + + align:start position:0% +axis is always at right angles to the + + + align:start position:0% +axis is always at right angles to the +axis all the branches May curve + + align:start position:0% +axis all the branches May curve + + + align:start position:0% +axis all the branches May curve +immediately after leaving the real axis + + align:start position:0% +immediately after leaving the real axis + + + align:start position:0% +immediately after leaving the real axis +so the Breakaway occurs at right angles + + align:start position:0% +so the Breakaway occurs at right angles + + + align:start position:0% +so the Breakaway occurs at right angles +if we went through the G ofs that + + align:start position:0% +if we went through the G ofs that + + + align:start position:0% +if we went through the G ofs that +corresponds to this example and solved + + align:start position:0% +corresponds to this example and solved + + + align:start position:0% +corresponds to this example and solved +for break away points we would find that + + align:start position:0% +for break away points we would find that + + + align:start position:0% +for break away points we would find that +it was in fact at the arithmetic mean of + + align:start position:0% +it was in fact at the arithmetic mean of + + + align:start position:0% +it was in fact at the arithmetic mean of +the loop transmission pole + + align:start position:0% + + + + align:start position:0% + +locations rule four uh has to do with + + align:start position:0% +locations rule four uh has to do with + + + align:start position:0% +locations rule four uh has to do with +the average distance of branches from + + align:start position:0% +the average distance of branches from + + + align:start position:0% +the average distance of branches from +the imaginary axis and in particular it + + align:start position:0% +the imaginary axis and in particular it + + + align:start position:0% +the imaginary axis and in particular it +tells us that if the number of poles + + align:start position:0% +tells us that if the number of poles + + + align:start position:0% +tells us that if the number of poles +associated with the loop transmission + + align:start position:0% +associated with the loop transmission + + + align:start position:0% +associated with the loop transmission +which I'll denote by capital P capital P + + align:start position:0% +which I'll denote by capital P capital P + + + align:start position:0% +which I'll denote by capital P capital P +is a number of poles of the loop + + align:start position:0% +is a number of poles of the loop + + + align:start position:0% +is a number of poles of the loop +transmission capital Z is the number of + + align:start position:0% +transmission capital Z is the number of + + + align:start position:0% +transmission capital Z is the number of +zeros associated with Loop transmission + + align:start position:0% +zeros associated with Loop transmission + + + align:start position:0% +zeros associated with Loop transmission +if the number of poles of the loop + + align:start position:0% +if the number of poles of the loop + + + align:start position:0% +if the number of poles of the loop +transmission exceeds the number of zeros + + align:start position:0% +transmission exceeds the number of zeros + + + align:start position:0% +transmission exceeds the number of zeros +by two or more then the average distance + + align:start position:0% +by two or more then the average distance + + + align:start position:0% +by two or more then the average distance +of all closed loop poles from the real + + align:start position:0% +of all closed loop poles from the real + + + align:start position:0% +of all closed loop poles from the real +axis remains + + align:start position:0% +axis remains + + + align:start position:0% +axis remains +constant the proof of this is an + + align:start position:0% +constant the proof of this is an + + + align:start position:0% +constant the proof of this is an +algebraic one I do it in the book and I + + align:start position:0% +algebraic one I do it in the book and I + + + align:start position:0% +algebraic one I do it in the book and I +won't do it here we've again seen that + + align:start position:0% +won't do it here we've again seen that + + + align:start position:0% +won't do it here we've again seen that +behavior in our sample second order + + align:start position:0% +behavior in our sample second order + + + align:start position:0% +behavior in our sample second order +system + + align:start position:0% +system + + + align:start position:0% +system +here again the average distance of the + + align:start position:0% +here again the average distance of the + + + align:start position:0% +here again the average distance of the +two Loop transmission poles from the + + align:start position:0% +two Loop transmission poles from the + + + align:start position:0% +two Loop transmission poles from the +imaginary axis is the quantity shown + + align:start position:0% +imaginary axis is the quantity shown + + + align:start position:0% +imaginary axis is the quantity shown +since our closed loop poles start for + + align:start position:0% +since our closed loop poles start for + + + align:start position:0% +since our closed loop poles start for +small values of a f at these two + + align:start position:0% +small values of a f at these two + + + align:start position:0% +small values of a f at these two +locations that tells us that as the + + align:start position:0% +locations that tells us that as the + + + align:start position:0% +locations that tells us that as the +branches move that average has to be + + align:start position:0% +branches move that average has to be + + + align:start position:0% +branches move that average has to be +maintained and in fact what that implies + + align:start position:0% +maintained and in fact what that implies + + + align:start position:0% +maintained and in fact what that implies +is something we didn't get readily from + + align:start position:0% +is something we didn't get readily from + + + align:start position:0% +is something we didn't get readily from +the algebraic development we had already + + align:start position:0% +the algebraic development we had already + + + align:start position:0% +the algebraic development we had already +performed although we could have gotten + + align:start position:0% +performed although we could have gotten + + + align:start position:0% +performed although we could have gotten +it what it says is that when we + + align:start position:0% +it what it says is that when we + + + align:start position:0% +it what it says is that when we +have achieved a value of a f knot that + + align:start position:0% +have achieved a value of a f knot that + + + align:start position:0% +have achieved a value of a f knot that +gets us to move a given distance inward + + align:start position:0% +gets us to move a given distance inward + + + align:start position:0% +gets us to move a given distance inward +from this Loop transmission pole this + + align:start position:0% +from this Loop transmission pole this + + + align:start position:0% +from this Loop transmission pole this +branch has moved by precisely the same + + align:start position:0% +branch has moved by precisely the same + + + align:start position:0% +branch has moved by precisely the same +distance inward from this closed loop or + + align:start position:0% +distance inward from this closed loop or + + + align:start position:0% +distance inward from this closed loop or +this Loop transmission pole location so + + align:start position:0% +this Loop transmission pole location so + + + align:start position:0% +this Loop transmission pole location so +as these branches move they have to move + + align:start position:0% +as these branches move they have to move + + + align:start position:0% +as these branches move they have to move +symmetrically + + align:start position:0% +symmetrically + + + align:start position:0% +symmetrically +we of course find out that that + + align:start position:0% +we of course find out that that + + + align:start position:0% +we of course find out that that +condition is maintained as we get to + + align:start position:0% +condition is maintained as we get to + + + align:start position:0% +condition is maintained as we get to +complex conjugate pole pairs because + + align:start position:0% +complex conjugate pole pairs because + + + align:start position:0% +complex conjugate pole pairs because +again the average distance this distance + + align:start position:0% +again the average distance this distance + + + align:start position:0% +again the average distance this distance +plus this distance ided two equals this + + align:start position:0% +plus this distance ided two equals this + + + align:start position:0% +plus this distance ided two equals this +distance plus this distance divided + + align:start position:0% + + + + align:start position:0% + +two rule number five basically deals + + align:start position:0% +two rule number five basically deals + + + align:start position:0% +two rule number five basically deals +with what direction is Infinity uh as + + align:start position:0% +with what direction is Infinity uh as + + + align:start position:0% +with what direction is Infinity uh as +I'd mentioned in the discussion of rule + + align:start position:0% +I'd mentioned in the discussion of rule + + + align:start position:0% +I'd mentioned in the discussion of rule +number one in particular we're + + align:start position:0% +number one in particular we're + + + align:start position:0% +number one in particular we're +interested in the ASM tootes that the + + align:start position:0% +interested in the ASM tootes that the + + + align:start position:0% +interested in the ASM tootes that the +branches make for large values of a + + align:start position:0% +branches make for large values of a + + + align:start position:0% +branches make for large values of a +fnot and the way we evaluate that is as + + align:start position:0% +fnot and the way we evaluate that is as + + + align:start position:0% +fnot and the way we evaluate that is as +follows consider a root Locus diagram + + align:start position:0% +follows consider a root Locus diagram + + + align:start position:0% +follows consider a root Locus diagram +and let's suppose we want to evaluate + + align:start position:0% +and let's suppose we want to evaluate + + + align:start position:0% +and let's suppose we want to evaluate +the angle associated with G of s when + + align:start position:0% +the angle associated with G of s when + + + align:start position:0% +the angle associated with G of s when +we're very far from the origin in other + + align:start position:0% +we're very far from the origin in other + + + align:start position:0% +we're very far from the origin in other +words let's consider what happens when + + align:start position:0% +words let's consider what happens when + + + align:start position:0% +words let's consider what happens when +we're evaluating the angle of G of s + + align:start position:0% +we're evaluating the angle of G of s + + + align:start position:0% +we're evaluating the angle of G of s +somewhere out + + align:start position:0% +somewhere out + + + align:start position:0% +somewhere out +here as we look from our test point back + + align:start position:0% +here as we look from our test point back + + + align:start position:0% +here as we look from our test point back +toward the finite s plane why all the + + align:start position:0% +toward the finite s plane why all the + + + align:start position:0% +toward the finite s plane why all the +poles and zeros associated with G of s + + align:start position:0% +poles and zeros associated with G of s + + + align:start position:0% +poles and zeros associated with G of s +make just about the same angle the + + align:start position:0% +make just about the same angle the + + + align:start position:0% +make just about the same angle the +vectors to all of those poles make just + + align:start position:0% +vectors to all of those poles make just + + + align:start position:0% +vectors to all of those poles make just +about the same angle with the real axis + + align:start position:0% +about the same angle with the real axis + + + align:start position:0% +about the same angle with the real axis +in other words when we're evaluating the + + align:start position:0% +in other words when we're evaluating the + + + align:start position:0% +in other words when we're evaluating the +angle way up there uh it doesn't matter + + align:start position:0% +angle way up there uh it doesn't matter + + + align:start position:0% +angle way up there uh it doesn't matter +much which of these poles are zeros we + + align:start position:0% +much which of these poles are zeros we + + + align:start position:0% +much which of these poles are zeros we +draw the vector from the angle is just + + align:start position:0% +draw the vector from the angle is just + + + align:start position:0% +draw the vector from the angle is just +about the + + align:start position:0% +about the + + + align:start position:0% +about the +same and consequently the angle of G of + + align:start position:0% +same and consequently the angle of G of + + + align:start position:0% +same and consequently the angle of G of +s evaluated at a point far from the + + align:start position:0% +s evaluated at a point far from the + + + align:start position:0% +s evaluated at a point far from the +origin is equal + + align:start position:0% +origin is equal + + + align:start position:0% +origin is equal +to or must satisfy the condition such + + align:start position:0% +to or must satisfy the condition such + + + align:start position:0% +to or must satisfy the condition such +that Z * Theta Theta is the angle of + + align:start position:0% +that Z * Theta Theta is the angle of + + + align:start position:0% +that Z * Theta Theta is the angle of +course z is the number of zeros minus P + + align:start position:0% +course z is the number of zeros minus P + + + align:start position:0% +course z is the number of zeros minus P +* Theta p is the number of poles must + + align:start position:0% +* Theta p is the number of poles must + + + align:start position:0% +* Theta p is the number of poles must +equal an odd multiple of 180 degre + + align:start position:0% +equal an odd multiple of 180 degre + + + align:start position:0% +equal an odd multiple of 180 degre +we can solve that equation to determine + + align:start position:0% +we can solve that equation to determine + + + align:start position:0% +we can solve that equation to determine +Theta and that gives us the ASM totic + + align:start position:0% +Theta and that gives us the ASM totic + + + align:start position:0% +Theta and that gives us the ASM totic +behavior of the branches far from the + + align:start position:0% +behavior of the branches far from the + + + align:start position:0% +behavior of the branches far from the +origin if we did that we'd get the Theta + + align:start position:0% +origin if we did that we'd get the Theta + + + align:start position:0% +origin if we did that we'd get the Theta +has to be equal to an odd multiple of + + align:start position:0% +has to be equal to an odd multiple of + + + align:start position:0% +has to be equal to an odd multiple of +180° actually over Z minus P this really + + align:start position:0% +180° actually over Z minus P this really + + + align:start position:0% +180° actually over Z minus P this really +isn't an error however because we're + + align:start position:0% +isn't an error however because we're + + + align:start position:0% +isn't an error however because we're +going to allow n to take on all possible + + align:start position:0% +going to allow n to take on all possible + + + align:start position:0% +going to allow n to take on all possible +integral values both positive and + + align:start position:0% +integral values both positive and + + + align:start position:0% +integral values both positive and +negative by convention since most + + align:start position:0% +negative by convention since most + + + align:start position:0% +negative by convention since most +systems have more poles in their Loop + + align:start position:0% +systems have more poles in their Loop + + + align:start position:0% +systems have more poles in their Loop +trans Mission than zeros reflecting the + + align:start position:0% +trans Mission than zeros reflecting the + + + align:start position:0% +trans Mission than zeros reflecting the +fact that that the world is basically + + align:start position:0% +fact that that the world is basically + + + align:start position:0% +fact that that the world is basically +low pass in nature we choose to write + + align:start position:0% +low pass in nature we choose to write + + + align:start position:0% +low pass in nature we choose to write +the denominator in a way that it becomes + + align:start position:0% +the denominator in a way that it becomes + + + align:start position:0% +the denominator in a way that it becomes +positive so we write the denominator as + + align:start position:0% +positive so we write the denominator as + + + align:start position:0% +positive so we write the denominator as +P minus Z we've already seen that + + align:start position:0% +P minus Z we've already seen that + + + align:start position:0% +P minus Z we've already seen that +behavior again in the one root Locus + + align:start position:0% +behavior again in the one root Locus + + + align:start position:0% +behavior again in the one root Locus +diagram that we've + + align:start position:0% +diagram that we've + + + align:start position:0% +diagram that we've +constructed here we have two poles + + align:start position:0% +constructed here we have two poles + + + align:start position:0% +constructed here we have two poles +capital P is 2 Z is zero and so if we + + align:start position:0% +capital P is 2 Z is zero and so if we + + + align:start position:0% +capital P is 2 Z is zero and so if we +took uh n equal to zero and solved for + + align:start position:0% +took uh n equal to zero and solved for + + + align:start position:0% +took uh n equal to zero and solved for +the Ang Les of the ASM tootes we'd find + + align:start position:0% +the Ang Les of the ASM tootes we'd find + + + align:start position:0% +the Ang Les of the ASM tootes we'd find +out that those angles were or that angle + + align:start position:0% +out that those angles were or that angle + + + align:start position:0% +out that those angles were or that angle +was 180° divided by 2 in other words + + align:start position:0% +was 180° divided by 2 in other words + + + align:start position:0% +was 180° divided by 2 in other words +plus + + align:start position:0% +plus + + + align:start position:0% +plus +90° similarly when we allowed n to be + + align:start position:0% +90° similarly when we allowed n to be + + + align:start position:0% +90° similarly when we allowed n to be +equal to 1 we'd find that the angle was + + align:start position:0% +equal to 1 we'd find that the angle was + + + align:start position:0% +equal to 1 we'd find that the angle was +3 * + + align:start position:0% +3 * + + + align:start position:0% +3 * +180° ided 2 or + + align:start position:0% +180° ided 2 or + + + align:start position:0% +180° ided 2 or +270° so that gets us an as ASM toote in + + align:start position:0% +270° so that gets us an as ASM toote in + + + align:start position:0% +270° so that gets us an as ASM toote in +this direction similarly if we allowed n + + align:start position:0% +this direction similarly if we allowed n + + + align:start position:0% +this direction similarly if we allowed n +to take on larger Val values we just get + + align:start position:0% +to take on larger Val values we just get + + + align:start position:0% +to take on larger Val values we just get +cyclical values would repeat the 90° and + + align:start position:0% +cyclical values would repeat the 90° and + + + align:start position:0% +cyclical values would repeat the 90° and +270° that we've already seen so there's + + align:start position:0% +270° that we've already seen so there's + + + align:start position:0% +270° that we've already seen so there's +no further information gained from that + + align:start position:0% +no further information gained from that + + + align:start position:0% +no further information gained from that +in this particular system the branches + + align:start position:0% +in this particular system the branches + + + align:start position:0% +in this particular system the branches +coincide with the ASM tootes uh as soon + + align:start position:0% +coincide with the ASM tootes uh as soon + + + align:start position:0% +coincide with the ASM tootes uh as soon +as the branches leave the real axis that + + align:start position:0% +as the branches leave the real axis that + + + align:start position:0% +as the branches leave the real axis that +isn't always the case of + + align:start position:0% + + + + align:start position:0% + +course the second part of rule five + + align:start position:0% +course the second part of rule five + + + align:start position:0% +course the second part of rule five +really tells us where the asmm tootes + + align:start position:0% +really tells us where the asmm tootes + + + align:start position:0% +really tells us where the asmm tootes +intersect the real axis + + align:start position:0% +intersect the real axis + + + align:start position:0% +intersect the real axis +and that intersection by an algebraic + + align:start position:0% +and that intersection by an algebraic + + + align:start position:0% +and that intersection by an algebraic +development simply comes at the sum of + + align:start position:0% +development simply comes at the sum of + + + align:start position:0% +development simply comes at the sum of +the real part of the poles of G of s + + align:start position:0% +the real part of the poles of G of s + + + align:start position:0% +the real part of the poles of G of s +minus the sum of the real part of the + + align:start position:0% +minus the sum of the real part of the + + + align:start position:0% +minus the sum of the real part of the +zeros of G of s once again divided by + + align:start position:0% +zeros of G of s once again divided by + + + align:start position:0% +zeros of G of s once again divided by +the number of poles minus the number of + + align:start position:0% +the number of poles minus the number of + + + align:start position:0% +the number of poles minus the number of +zeros associated with the loop + + align:start position:0% +zeros associated with the loop + + + align:start position:0% +zeros associated with the loop +transmission so this again we could + + align:start position:0% +transmission so this again we could + + + align:start position:0% +transmission so this again we could +check for our particular system we have + + align:start position:0% +check for our particular system we have + + + align:start position:0% +check for our particular system we have +simply Two Poles uh so if we add the + + align:start position:0% +simply Two Poles uh so if we add the + + + align:start position:0% +simply Two Poles uh so if we add the +real parts of the poles divide by two we + + align:start position:0% +real parts of the poles divide by two we + + + align:start position:0% +real parts of the poles divide by two we +end up with the ASM toote intersection + + align:start position:0% +end up with the ASM toote intersection + + + align:start position:0% +end up with the ASM toote intersection +being at the average distance of the + + align:start position:0% +being at the average distance of the + + + align:start position:0% +being at the average distance of the +poles from the imaginary axis the poles + + align:start position:0% +poles from the imaginary axis the poles + + + align:start position:0% +poles from the imaginary axis the poles +of G of s from the imaginary + + align:start position:0% +of G of s from the imaginary + + + align:start position:0% +of G of s from the imaginary +axis rule six tells us the angle that a + + align:start position:0% +axis rule six tells us the angle that a + + + align:start position:0% +axis rule six tells us the angle that a +branch makes uh either leaving a complex + + align:start position:0% +branch makes uh either leaving a complex + + + align:start position:0% +branch makes uh either leaving a complex +conjugate pole for small values of a KN + + align:start position:0% +conjugate pole for small values of a KN + + + align:start position:0% +conjugate pole for small values of a KN +F KN or entering a complex conjugate + + align:start position:0% +F KN or entering a complex conjugate + + + align:start position:0% +F KN or entering a complex conjugate +zero for very large Val values of a FN + + align:start position:0% +zero for very large Val values of a FN + + + align:start position:0% +zero for very large Val values of a FN +in other words if we were interested in + + align:start position:0% +in other words if we were interested in + + + align:start position:0% +in other words if we were interested in +how the branches of the root Locus + + align:start position:0% +how the branches of the root Locus + + + align:start position:0% +how the branches of the root Locus +diagram eventually reached this zero for + + align:start position:0% +diagram eventually reached this zero for + + + align:start position:0% +diagram eventually reached this zero for +very large values of a fnot a branch + + align:start position:0% +very large values of a fnot a branch + + + align:start position:0% +very large values of a fnot a branch +might come into that point uh from + + align:start position:0% +might come into that point uh from + + + align:start position:0% +might come into that point uh from +somewhere in the S plane for + + align:start position:0% +somewhere in the S plane for + + + align:start position:0% +somewhere in the S plane for +sufficiently large values of a fnot and + + align:start position:0% +sufficiently large values of a fnot and + + + align:start position:0% +sufficiently large values of a fnot and +if we were interested in this angle in + + align:start position:0% +if we were interested in this angle in + + + align:start position:0% +if we were interested in this angle in +other words the angle that that Branch + + align:start position:0% +other words the angle that that Branch + + + align:start position:0% +other words the angle that that Branch +had at the time it entered or for the + + align:start position:0% +had at the time it entered or for the + + + align:start position:0% +had at the time it entered or for the +value of a fnot uh when it enters that + + align:start position:0% +value of a fnot uh when it enters that + + + align:start position:0% +value of a fnot uh when it enters that +zero or reaches that zero in particular + + align:start position:0% +zero or reaches that zero in particular + + + align:start position:0% +zero or reaches that zero in particular +this angle why we can determine that + + align:start position:0% +this angle why we can determine that + + + align:start position:0% +this angle why we can determine that +angle by simply evaluating the angle uh + + align:start position:0% +angle by simply evaluating the angle uh + + + align:start position:0% +angle by simply evaluating the angle uh +from all of the poles of G of s taking + + align:start position:0% +from all of the poles of G of s taking + + + align:start position:0% +from all of the poles of G of s taking +the sum of + + align:start position:0% +the sum of + + + align:start position:0% +the sum of +180° plus the angle from all of the + + align:start position:0% +180° plus the angle from all of the + + + align:start position:0% +180° plus the angle from all of the +poles of G of s to the zero in question + + align:start position:0% +poles of G of s to the zero in question + + + align:start position:0% +poles of G of s to the zero in question +minus the angle from all of the other + + align:start position:0% +minus the angle from all of the other + + + align:start position:0% +minus the angle from all of the other +zeros of G of s to the zero in question + + align:start position:0% +zeros of G of s to the zero in question + + + align:start position:0% +zeros of G of s to the zero in question +so this is simply a way of satisfying + + align:start position:0% +so this is simply a way of satisfying + + + align:start position:0% +so this is simply a way of satisfying +the odd multiple of + + align:start position:0% +the odd multiple of + + + align:start position:0% +the odd multiple of +180° at a point in the S plane we can do + + align:start position:0% +180° at a point in the S plane we can do + + + align:start position:0% +180° at a point in the S plane we can do +the same thing if we ask at what angle + + align:start position:0% +the same thing if we ask at what angle + + + align:start position:0% +the same thing if we ask at what angle +does a branch depart a complex conjugate + + align:start position:0% +does a branch depart a complex conjugate + + + align:start position:0% +does a branch depart a complex conjugate +pole for small values of a f you simply + + align:start position:0% +pole for small values of a f you simply + + + align:start position:0% +pole for small values of a f you simply +keep track of the arithmetic you find + + align:start position:0% +keep track of the arithmetic you find + + + align:start position:0% +keep track of the arithmetic you find +out that's + + align:start position:0% +out that's + + + align:start position:0% +out that's +180° plus the sum of the angles when we + + align:start position:0% +180° plus the sum of the angles when we + + + align:start position:0% +180° plus the sum of the angles when we +draw vectors from all of the zeros of + + align:start position:0% +draw vectors from all of the zeros of + + + align:start position:0% +draw vectors from all of the zeros of +the loop transmission to the pole in + + align:start position:0% +the loop transmission to the pole in + + + align:start position:0% +the loop transmission to the pole in +question minus the sum of the angles + + align:start position:0% +question minus the sum of the angles + + + align:start position:0% +question minus the sum of the angles +when we draw vectors from all of the + + align:start position:0% +when we draw vectors from all of the + + + align:start position:0% +when we draw vectors from all of the +poles of the loop transmission to the + + align:start position:0% +poles of the loop transmission to the + + + align:start position:0% +poles of the loop transmission to the +pole in question as to say proving that + + align:start position:0% +pole in question as to say proving that + + + align:start position:0% +pole in question as to say proving that +relationship uh simply involves keeping + + align:start position:0% +relationship uh simply involves keeping + + + align:start position:0% +relationship uh simply involves keeping +books to ensure that we have a net angle + + align:start position:0% +books to ensure that we have a net angle + + + align:start position:0% +books to ensure that we have a net angle +of 180 + + align:start position:0% +of 180 + + + align:start position:0% +of 180 +degrees rule seven is a powerful one + + align:start position:0% +degrees rule seven is a powerful one + + + align:start position:0% +degrees rule seven is a powerful one +which allows us quite often to very + + align:start position:0% +which allows us quite often to very + + + align:start position:0% +which allows us quite often to very +rapidly sketch certain important + + align:start position:0% +rapidly sketch certain important + + + align:start position:0% +rapidly sketch certain important +features of the closed loop transfer + + align:start position:0% +features of the closed loop transfer + + + align:start position:0% +features of the closed loop transfer +function + + align:start position:0% +function + + + align:start position:0% +function +in particular what it tells us is that + + align:start position:0% +in particular what it tells us is that + + + align:start position:0% +in particular what it tells us is that +we have a system which includes a + + align:start position:0% +we have a system which includes a + + + align:start position:0% +we have a system which includes a +collection of poles quite near the + + align:start position:0% +collection of poles quite near the + + + align:start position:0% +collection of poles quite near the +origin relative to some others we're + + align:start position:0% +origin relative to some others we're + + + align:start position:0% +origin relative to some others we're +able to ignore the remote poles and in + + align:start position:0% +able to ignore the remote poles and in + + + align:start position:0% +able to ignore the remote poles and in +fact remote zeros when we're interested + + align:start position:0% +fact remote zeros when we're interested + + + align:start position:0% +fact remote zeros when we're interested +in the behavior of the root Locust + + align:start position:0% +in the behavior of the root Locust + + + align:start position:0% +in the behavior of the root Locust +diagram near the + + align:start position:0% +diagram near the + + + align:start position:0% +diagram near the +origin we can see how that works Suppose + + align:start position:0% +origin we can see how that works Suppose + + + align:start position:0% +origin we can see how that works Suppose +there are a collection of of poles and + + align:start position:0% +there are a collection of of poles and + + + align:start position:0% +there are a collection of of poles and +zeros associated with the loop + + align:start position:0% +zeros associated with the loop + + + align:start position:0% +zeros associated with the loop +transmission that are somewhere down + + align:start position:0% +transmission that are somewhere down + + + align:start position:0% +transmission that are somewhere down +near the + + align:start position:0% +near the + + + align:start position:0% +near the +origin and then there are some + + align:start position:0% +origin and then there are some + + + align:start position:0% +origin and then there are some +additional ones at much higher + + align:start position:0% +additional ones at much higher + + + align:start position:0% +additional ones at much higher +frequencies or much further from the + + align:start position:0% +frequencies or much further from the + + + align:start position:0% +frequencies or much further from the +origin possibly out here this very + + align:start position:0% +origin possibly out here this very + + + align:start position:0% +origin possibly out here this very +frequently happens when we look at at + + align:start position:0% +frequently happens when we look at at + + + align:start position:0% +frequently happens when we look at at +the behavior for example of a transistor + + align:start position:0% +the behavior for example of a transistor + + + align:start position:0% +the behavior for example of a transistor +amplifier an operational amplifier where + + align:start position:0% +amplifier an operational amplifier where + + + align:start position:0% +amplifier an operational amplifier where +there are certain poles possibly those + + align:start position:0% +there are certain poles possibly those + + + align:start position:0% +there are certain poles possibly those +due to collector to base capacitance or + + align:start position:0% +due to collector to base capacitance or + + + align:start position:0% +due to collector to base capacitance or +intentional capacitors that we've added + + align:start position:0% +intentional capacitors that we've added + + + align:start position:0% +intentional capacitors that we've added +to the Circuit that are relatively low + + align:start position:0% +to the Circuit that are relatively low + + + align:start position:0% +to the Circuit that are relatively low +frequency in in nature and there may be + + align:start position:0% +frequency in in nature and there may be + + + align:start position:0% +frequency in in nature and there may be +some zeros at relatively low frequencies + + align:start position:0% +some zeros at relatively low frequencies + + + align:start position:0% +some zeros at relatively low frequencies +as well well and then very frequently + + align:start position:0% +as well well and then very frequently + + + align:start position:0% +as well well and then very frequently +there are other much higher frequency + + align:start position:0% +there are other much higher frequency + + + align:start position:0% +there are other much higher frequency +poles and possibly zeros typically + + align:start position:0% +poles and possibly zeros typically + + + align:start position:0% +poles and possibly zeros typically +occurring out at about Omega T the gain + + align:start position:0% +occurring out at about Omega T the gain + + + align:start position:0% +occurring out at about Omega T the gain +bandwidth product for the transistor and + + align:start position:0% +bandwidth product for the transistor and + + + align:start position:0% +bandwidth product for the transistor and +so this sort of a a pattern very + + align:start position:0% +so this sort of a a pattern very + + + align:start position:0% +so this sort of a a pattern very +frequently exists in electronic + + align:start position:0% +frequently exists in electronic + + + align:start position:0% +frequently exists in electronic +amplifiers similarly uh we can find this + + align:start position:0% +amplifiers similarly uh we can find this + + + align:start position:0% +amplifiers similarly uh we can find this +sort of thing in a mechanical system + + align:start position:0% +sort of thing in a mechanical system + + + align:start position:0% +sort of thing in a mechanical system +there may be certain poles due to the + + align:start position:0% +there may be certain poles due to the + + + align:start position:0% +there may be certain poles due to the +energy storage in lump masses and + + align:start position:0% +energy storage in lump masses and + + + align:start position:0% +energy storage in lump masses and +springs in the system and then we get + + align:start position:0% +springs in the system and then we get + + + align:start position:0% +springs in the system and then we get +into much higher frequency poles poles + + align:start position:0% +into much higher frequency poles poles + + + align:start position:0% +into much higher frequency poles poles +much more remote from the axxis that + + align:start position:0% +much more remote from the axxis that + + + align:start position:0% +much more remote from the axxis that +have to do with things like mechanical + + align:start position:0% +have to do with things like mechanical + + + align:start position:0% +have to do with things like mechanical +resonances in the system so this this + + align:start position:0% +resonances in the system so this this + + + align:start position:0% +resonances in the system so this this +kind of a situation exists quite + + align:start position:0% +kind of a situation exists quite + + + align:start position:0% +kind of a situation exists quite +frequently in feedback systems of + + align:start position:0% +frequently in feedback systems of + + + align:start position:0% +frequently in feedback systems of +Interest well to see why we might be + + align:start position:0% +Interest well to see why we might be + + + align:start position:0% +Interest well to see why we might be +able to ignore remote poles and zeros + + align:start position:0% +able to ignore remote poles and zeros + + + align:start position:0% +able to ignore remote poles and zeros +when we evaluate the or look for the + + align:start position:0% +when we evaluate the or look for the + + + align:start position:0% +when we evaluate the or look for the +branches in the vicinity of the origin + + align:start position:0% +branches in the vicinity of the origin + + + align:start position:0% +branches in the vicinity of the origin +suppose we had found out that this + + align:start position:0% +suppose we had found out that this + + + align:start position:0% +suppose we had found out that this +particular point in fact satisfied the + + align:start position:0% +particular point in fact satisfied the + + + align:start position:0% +particular point in fact satisfied the +conditions necessary to be on a branch + + align:start position:0% +conditions necessary to be on a branch + + + align:start position:0% +conditions necessary to be on a branch +in the absence of these higher frequency + + align:start position:0% +in the absence of these higher frequency + + + align:start position:0% +in the absence of these higher frequency +poles in other words when we evaluated + + align:start position:0% +poles in other words when we evaluated + + + align:start position:0% +poles in other words when we evaluated +the net angle + + align:start position:0% +the net angle + + + align:start position:0% +the net angle +associated with all of these poles and + + align:start position:0% +associated with all of these poles and + + + align:start position:0% +associated with all of these poles and +zeros we'd find out that the net angle + + align:start position:0% +zeros we'd find out that the net angle + + + align:start position:0% +zeros we'd find out that the net angle +evaluated at this point was an odd + + align:start position:0% +evaluated at this point was an odd + + + align:start position:0% +evaluated at this point was an odd +multiple of + + align:start position:0% +multiple of + + + align:start position:0% +multiple of +180° we now ask how does that change if + + align:start position:0% +180° we now ask how does that change if + + + align:start position:0% +180° we now ask how does that change if +we consider the remote poles well we + + align:start position:0% +we consider the remote poles well we + + + align:start position:0% +we consider the remote poles well we +draw some vectors from the remote poles + + align:start position:0% + + + + align:start position:0% + +but the net angular contribution from + + align:start position:0% +but the net angular contribution from + + + align:start position:0% +but the net angular contribution from +those remote poles is quite small this + + align:start position:0% +those remote poles is quite small this + + + align:start position:0% +those remote poles is quite small this +angle is small and in fact the complex + + align:start position:0% +angle is small and in fact the complex + + + align:start position:0% +angle is small and in fact the complex +conjugate pair sum to a very small angle + + align:start position:0% +conjugate pair sum to a very small angle + + + align:start position:0% +conjugate pair sum to a very small angle +while one of these angles is quite large + + align:start position:0% +while one of these angles is quite large + + + align:start position:0% +while one of these angles is quite large +the sum of these two angles is very + + align:start position:0% +the sum of these two angles is very + + + align:start position:0% +the sum of these two angles is very +small so the remote poles don't change + + align:start position:0% +small so the remote poles don't change + + + align:start position:0% +small so the remote poles don't change +the net angle of G of s very much + + align:start position:0% +the net angle of G of s very much + + + align:start position:0% +the net angle of G of s very much +evaluated at this point and we can make + + align:start position:0% +evaluated at this point and we can make + + + align:start position:0% +evaluated at this point and we can make +up for that very small change by simply + + align:start position:0% +up for that very small change by simply + + + align:start position:0% +up for that very small change by simply +relocating our Branch a tiny amount + + align:start position:0% +relocating our Branch a tiny amount + + + align:start position:0% +relocating our Branch a tiny amount +recognizing that moving our test point a + + align:start position:0% +recognizing that moving our test point a + + + align:start position:0% +recognizing that moving our test point a +very small amount has a tremendous + + align:start position:0% +very small amount has a tremendous + + + align:start position:0% +very small amount has a tremendous +effect on the angles associated with the + + align:start position:0% +effect on the angles associated with the + + + align:start position:0% +effect on the angles associated with the +vectors from these local poles and zeros + + align:start position:0% +vectors from these local poles and zeros + + + align:start position:0% +vectors from these local poles and zeros +consequently the conclusion that that + + align:start position:0% +consequently the conclusion that that + + + align:start position:0% +consequently the conclusion that that +the remote poles and zeros don't really + + align:start position:0% +the remote poles and zeros don't really + + + align:start position:0% +the remote poles and zeros don't really +contribute very much to the behavior of + + align:start position:0% +contribute very much to the behavior of + + + align:start position:0% +contribute very much to the behavior of +the root Locus diagram in this + + align:start position:0% + + + + align:start position:0% + +vicinity rule 8 is simply a restatement + + align:start position:0% +vicinity rule 8 is simply a restatement + + + align:start position:0% +vicinity rule 8 is simply a restatement +of the magnitude condition in other + + align:start position:0% +of the magnitude condition in other + + + align:start position:0% +of the magnitude condition in other +words once we found a point S1 in the S + + align:start position:0% +words once we found a point S1 in the S + + + align:start position:0% +words once we found a point S1 in the S +plane where the angle condition is + + align:start position:0% +plane where the angle condition is + + + align:start position:0% +plane where the angle condition is +satisfied the value of a knot fnot + + align:start position:0% +satisfied the value of a knot fnot + + + align:start position:0% +satisfied the value of a knot fnot +necessary to get us to that point on the + + align:start position:0% +necessary to get us to that point on the + + + align:start position:0% +necessary to get us to that point on the +root Locus branch is simply equal to one + + align:start position:0% +root Locus branch is simply equal to one + + + align:start position:0% +root Locus branch is simply equal to one +over the or the magnitude of 1 over G of + + align:start position:0% +over the or the magnitude of 1 over G of + + + align:start position:0% +over the or the magnitude of 1 over G of +G evaluated at that + + align:start position:0% +G evaluated at that + + + align:start position:0% +G evaluated at that +point well with that + + align:start position:0% +point well with that + + + align:start position:0% +point well with that +as a statement of the rules that we're + + align:start position:0% +as a statement of the rules that we're + + + align:start position:0% +as a statement of the rules that we're +going to use to draw root Locust + + align:start position:0% +going to use to draw root Locust + + + align:start position:0% +going to use to draw root Locust +diagrams I'd like to begin to look at + + align:start position:0% +diagrams I'd like to begin to look at + + + align:start position:0% +diagrams I'd like to begin to look at +some + + align:start position:0% +some + + + align:start position:0% +some +simple pole zero possibilities for Loop + + align:start position:0% +simple pole zero possibilities for Loop + + + align:start position:0% +simple pole zero possibilities for Loop +transmissions and then see the + + align:start position:0% +transmissions and then see the + + + align:start position:0% +transmissions and then see the +corresponding root Locust diagrams the + + align:start position:0% +corresponding root Locust diagrams the + + + align:start position:0% +corresponding root Locust diagrams the +simplest possible case is of course the + + align:start position:0% +simplest possible case is of course the + + + align:start position:0% +simplest possible case is of course the +first order system that has one Loop + + align:start position:0% +first order system that has one Loop + + + align:start position:0% +first order system that has one Loop +transmission pole on the negative real + + align:start position:0% +transmission pole on the negative real + + + align:start position:0% +transmission pole on the negative real +axis so here we have one located let's + + align:start position:0% +axis so here we have one located let's + + + align:start position:0% +axis so here we have one located let's +say at a point minus one over to + + align:start position:0% +say at a point minus one over to + + + align:start position:0% +say at a point minus one over to +a about the only rule we need here is + + align:start position:0% +a about the only rule we need here is + + + align:start position:0% +a about the only rule we need here is +rule number one it tells us that the + + align:start position:0% +rule number one it tells us that the + + + align:start position:0% +rule number one it tells us that the +negative real axis to the left of that + + align:start position:0% +negative real axis to the left of that + + + align:start position:0% +negative real axis to the left of that +Loop transmission pole uh is is a + + align:start position:0% +Loop transmission pole uh is is a + + + align:start position:0% +Loop transmission pole uh is is a +possible location for a branch of the + + align:start position:0% +possible location for a branch of the + + + align:start position:0% +possible location for a branch of the +root Locus diagram and furthermore there + + align:start position:0% +root Locus diagram and furthermore there + + + align:start position:0% +root Locus diagram and furthermore there +is only one branch associated with the + + align:start position:0% +is only one branch associated with the + + + align:start position:0% +is only one branch associated with the +root Locus diagram and so combining + + align:start position:0% +root Locus diagram and so combining + + + align:start position:0% +root Locus diagram and so combining +those two facts tells us that the root + + align:start position:0% +those two facts tells us that the root + + + align:start position:0% +those two facts tells us that the root +Locus diagram simply starts here for + + align:start position:0% +Locus diagram simply starts here for + + + align:start position:0% +Locus diagram simply starts here for +very small values of a f ends at a zero + + align:start position:0% +very small values of a f ends at a zero + + + align:start position:0% +very small values of a f ends at a zero +at Infinity which happens to in this + + align:start position:0% +at Infinity which happens to in this + + + align:start position:0% +at Infinity which happens to in this +case lie out along the negative real + + align:start position:0% +case lie out along the negative real + + + align:start position:0% +case lie out along the negative real +axis since we have one pole if we uh + + align:start position:0% +axis since we have one pole if we uh + + + align:start position:0% +axis since we have one pole if we uh +calculate an ASM toote for example we + + align:start position:0% +calculate an ASM toote for example we + + + align:start position:0% +calculate an ASM toote for example we +find that the ASM toote lies at minus + + align:start position:0% +find that the ASM toote lies at minus + + + align:start position:0% +find that the ASM toote lies at minus +180° so we get the branch traveling out + + align:start position:0% +180° so we get the branch traveling out + + + align:start position:0% +180° so we get the branch traveling out +the negative real axis like so for + + align:start position:0% +the negative real axis like so for + + + align:start position:0% +the negative real axis like so for +increasing a + + align:start position:0% +increasing a + + + align:start position:0% +increasing a +fot I think it's worth pointing out how + + align:start position:0% +fot I think it's worth pointing out how + + + align:start position:0% +fot I think it's worth pointing out how +that car responds with an earlier + + align:start position:0% +that car responds with an earlier + + + align:start position:0% +that car responds with an earlier +development that we've done we looked at + + align:start position:0% +development that we've done we looked at + + + align:start position:0% +development that we've done we looked at +the single pole case when we started our + + align:start position:0% +the single pole case when we started our + + + align:start position:0% +the single pole case when we started our +discussion of the D dynamics of feedback + + align:start position:0% +discussion of the D dynamics of feedback + + + align:start position:0% +discussion of the D dynamics of feedback +systems and uh in fact under under those + + align:start position:0% +systems and uh in fact under under those + + + align:start position:0% +systems and uh in fact under under those +conditions we started with an a of s + + align:start position:0% +conditions we started with an a of s + + + align:start position:0% +conditions we started with an a of s +that was equal to a KN over a single + + align:start position:0% +that was equal to a KN over a single + + + align:start position:0% +that was equal to a KN over a single +pole a single real axis pole and we + + align:start position:0% +pole a single real axis pole and we + + + align:start position:0% +pole a single real axis pole and we +assumed that F was frequency independent + + align:start position:0% +assumed that F was frequency independent + + + align:start position:0% +assumed that F was frequency independent +and equal to F when we calculated the + + align:start position:0% +and equal to F when we calculated the + + + align:start position:0% +and equal to F when we calculated the +closed loop transfer function we + + align:start position:0% +closed loop transfer function we + + + align:start position:0% +closed loop transfer function we +determined that capital A of s was + + align:start position:0% +determined that capital A of s was + + + align:start position:0% +determined that capital A of s was +simply equal to 1 over FN time 1/ to as + + align:start position:0% +simply equal to 1 over FN time 1/ to as + + + align:start position:0% +simply equal to 1 over FN time 1/ to as +/ a f plus 1/ a f + one certainly as we + + align:start position:0% +/ a f plus 1/ a f + one certainly as we + + + align:start position:0% +/ a f plus 1/ a f + one certainly as we +increase the a fot product the condition + + align:start position:0% +increase the a fot product the condition + + + align:start position:0% +increase the a fot product the condition +under which we construct our root Locus + + align:start position:0% +under which we construct our root Locus + + + align:start position:0% +under which we construct our root Locus +diagram the single closed loop pole + + align:start position:0% +diagram the single closed loop pole + + + align:start position:0% +diagram the single closed loop pole +simply moves toward higher frequencies + + align:start position:0% +simply moves toward higher frequencies + + + align:start position:0% +simply moves toward higher frequencies +in other words the coefficient + + align:start position:0% +in other words the coefficient + + + align:start position:0% +in other words the coefficient +associated with the S term becomes + + align:start position:0% +associated with the S term becomes + + + align:start position:0% +associated with the S term becomes +smaller and smaller and smaller in the + + align:start position:0% +smaller and smaller and smaller in the + + + align:start position:0% +smaller and smaller and smaller in the +denominator so we get the behavior that + + align:start position:0% +denominator so we get the behavior that + + + align:start position:0% +denominator so we get the behavior that +we've + + align:start position:0% +we've + + + align:start position:0% +we've +indicated the second order case we've + + align:start position:0% +indicated the second order case we've + + + align:start position:0% +indicated the second order case we've +looked at in considerable detail and so + + align:start position:0% +looked at in considerable detail and so + + + align:start position:0% +looked at in considerable detail and so +I won't look at that again a somewhat + + align:start position:0% +I won't look at that again a somewhat + + + align:start position:0% +I won't look at that again a somewhat +more inter Behavior exists when we + + align:start position:0% +more inter Behavior exists when we + + + align:start position:0% +more inter Behavior exists when we +consider the third order a third order + + align:start position:0% +consider the third order a third order + + + align:start position:0% +consider the third order a third order +system in other words a loop + + align:start position:0% +system in other words a loop + + + align:start position:0% +system in other words a loop +transmission that has three real axis + + align:start position:0% +transmission that has three real axis + + + align:start position:0% +transmission that has three real axis +poles associated with it with it our + + align:start position:0% +poles associated with it with it our + + + align:start position:0% +poles associated with it with it our +rule number one tells us that this + + align:start position:0% +rule number one tells us that this + + + align:start position:0% +rule number one tells us that this +region of the real axis where we have + + align:start position:0% +region of the real axis where we have + + + align:start position:0% +region of the real axis where we have +one pole to the right uh includes + + align:start position:0% +one pole to the right uh includes + + + align:start position:0% +one pole to the right uh includes +contains branches and that this portion + + align:start position:0% +contains branches and that this portion + + + align:start position:0% +contains branches and that this portion +of the real axis uh includes a branch + + align:start position:0% +of the real axis uh includes a branch + + + align:start position:0% +of the real axis uh includes a branch +furthermore we that there there has to + + align:start position:0% +furthermore we that there there has to + + + align:start position:0% +furthermore we that there there has to +be a breakaway Point uh in this region + + align:start position:0% +be a breakaway Point uh in this region + + + align:start position:0% +be a breakaway Point uh in this region +since here we have a branch or a pair of + + align:start position:0% +since here we have a branch or a pair of + + + align:start position:0% +since here we have a branch or a pair of +branches existing between two poles on + + align:start position:0% +branches existing between two poles on + + + align:start position:0% +branches existing between two poles on +the real axis so there has to be a + + align:start position:0% +the real axis so there has to be a + + + align:start position:0% +the real axis so there has to be a +breakaway somewhere between them we'd + + align:start position:0% +breakaway somewhere between them we'd + + + align:start position:0% +breakaway somewhere between them we'd +actually expect let's see that that + + align:start position:0% +actually expect let's see that that + + + align:start position:0% +actually expect let's see that that +Breakaway uh would have to be a little + + align:start position:0% +Breakaway uh would have to be a little + + + align:start position:0% +Breakaway uh would have to be a little +bit to the right of the midpoint if we + + align:start position:0% +bit to the right of the midpoint if we + + + align:start position:0% +bit to the right of the midpoint if we +keep track of the average distance + + align:start position:0% +keep track of the average distance + + + align:start position:0% +keep track of the average distance +because we recognize that this branch is + + align:start position:0% +because we recognize that this branch is + + + align:start position:0% +because we recognize that this branch is +continuously moving to the left + + align:start position:0% +continuously moving to the left + + + align:start position:0% +continuously moving to the left +consequently we'd anticipate that the + + align:start position:0% +consequently we'd anticipate that the + + + align:start position:0% +consequently we'd anticipate that the +Breakaway would have to be just a little + + align:start position:0% +Breakaway would have to be just a little + + + align:start position:0% +Breakaway would have to be just a little +bit to the right of the midpoint here in + + align:start position:0% +bit to the right of the midpoint here in + + + align:start position:0% +bit to the right of the midpoint here in +order to keep the average distance from + + align:start position:0% +order to keep the average distance from + + + align:start position:0% +order to keep the average distance from +the imaginary axis a constant so we + + align:start position:0% +the imaginary axis a constant so we + + + align:start position:0% +the imaginary axis a constant so we +might get a breakaway somewhere in + + align:start position:0% +might get a breakaway somewhere in + + + align:start position:0% +might get a breakaway somewhere in +here we also can calculate the angles of + + align:start position:0% +here we also can calculate the angles of + + + align:start position:0% +here we also can calculate the angles of +the ASM tootes which is useful in this + + align:start position:0% +the ASM tootes which is useful in this + + + align:start position:0% +the ASM tootes which is useful in this +case we have three poles and no zeros + + align:start position:0% +case we have three poles and no zeros + + + align:start position:0% +case we have three poles and no zeros +and consequently we would find expect + + align:start position:0% +and consequently we would find expect + + + align:start position:0% +and consequently we would find expect +ASM tootes at plus 60° 180° / 3 at 180 + + align:start position:0% +ASM tootes at plus 60° 180° / 3 at 180 + + + align:start position:0% +ASM tootes at plus 60° 180° / 3 at 180 +de which is + + align:start position:0% +de which is + + + align:start position:0% +de which is +540° / + + align:start position:0% +540° / + + + align:start position:0% +540° / +3 and let's see we'd also expect U + + align:start position:0% +3 and let's see we'd also expect U + + + align:start position:0% +3 and let's see we'd also expect U +another ASM toote at + + align:start position:0% +another ASM toote at + + + align:start position:0% +another ASM toote at +270° uh for this particular system in + + align:start position:0% +270° uh for this particular system in + + + align:start position:0% +270° uh for this particular system in +other in other words I'm sorry at 300° + + align:start position:0% +other in other words I'm sorry at 300° + + + align:start position:0% +other in other words I'm sorry at 300° +at minus 60° that's + + align:start position:0% +at minus 60° that's + + + align:start position:0% +at minus 60° that's +900° divided 3 so uh we'd anticipate for + + align:start position:0% +900° divided 3 so uh we'd anticipate for + + + align:start position:0% +900° divided 3 so uh we'd anticipate for +large values of a f that there'd be as + + align:start position:0% +large values of a f that there'd be as + + + align:start position:0% +large values of a f that there'd be as +asmp tootes at plus and minus 60° and at + + align:start position:0% +asmp tootes at plus and minus 60° and at + + + align:start position:0% +asmp tootes at plus and minus 60° and at +minus + + align:start position:0% +minus + + + align:start position:0% +minus +180° and the asmp tootes intersect + + align:start position:0% +180° and the asmp tootes intersect + + + align:start position:0% +180° and the asmp tootes intersect +somewhere on the negative part of the S + + align:start position:0% +somewhere on the negative part of the S + + + align:start position:0% +somewhere on the negative part of the S +plane since the real parts of all of + + align:start position:0% +plane since the real parts of all of + + + align:start position:0% +plane since the real parts of all of +these poles are negative and putting + + align:start position:0% +these poles are negative and putting + + + align:start position:0% +these poles are negative and putting +those things together we conclude that + + align:start position:0% +those things together we conclude that + + + align:start position:0% +those things together we conclude that +the + + align:start position:0% +the + + + align:start position:0% +the +behavior might be something as follows + + align:start position:0% +behavior might be something as follows + + + align:start position:0% +behavior might be something as follows +these branches eventually getting into + + align:start position:0% +these branches eventually getting into + + + align:start position:0% +these branches eventually getting into +the right into the right half plane + + align:start position:0% +the right into the right half plane + + + align:start position:0% +the right into the right half plane +inlying system of course this third + + align:start position:0% +inlying system of course this third + + + align:start position:0% +inlying system of course this third +order system can become unstable for + + align:start position:0% +order system can become unstable for + + + align:start position:0% +order system can become unstable for +sufficiently large values of a + + align:start position:0% +sufficiently large values of a + + + align:start position:0% +sufficiently large values of a +f and ultimately we get ASM tootes of + + align:start position:0% +f and ultimately we get ASM tootes of + + + align:start position:0% +f and ultimately we get ASM tootes of +plus or minus 60° associated with those + + align:start position:0% +plus or minus 60° associated with those + + + align:start position:0% +plus or minus 60° associated with those +that complex conjugate pair of + + align:start position:0% +that complex conjugate pair of + + + align:start position:0% +that complex conjugate pair of +branches it's interesting to point out a + + align:start position:0% +branches it's interesting to point out a + + + align:start position:0% +branches it's interesting to point out a +special case that we've investigated + + align:start position:0% +special case that we've investigated + + + align:start position:0% +special case that we've investigated +earlier of this three pole situation in + + align:start position:0% +earlier of this three pole situation in + + + align:start position:0% +earlier of this three pole situation in +particular one where we have three + + align:start position:0% +particular one where we have three + + + align:start position:0% +particular one where we have three +coincident poles if you recall we looked + + align:start position:0% +coincident poles if you recall we looked + + + align:start position:0% +coincident poles if you recall we looked +at this situation when we discussed the + + align:start position:0% +at this situation when we discussed the + + + align:start position:0% +at this situation when we discussed the +possibility for in stability in feedback + + align:start position:0% +possibility for in stability in feedback + + + align:start position:0% +possibility for in stability in feedback +systems and in that case the root Locus + + align:start position:0% +systems and in that case the root Locus + + + align:start position:0% +systems and in that case the root Locus +diagram is somewhat degenerate and in + + align:start position:0% +diagram is somewhat degenerate and in + + + align:start position:0% +diagram is somewhat degenerate and in +fact the branches immediately parallel + + align:start position:0% +fact the branches immediately parallel + + + align:start position:0% +fact the branches immediately parallel +the asmp tootes or lie along the ASM + + align:start position:0% +the asmp tootes or lie along the ASM + + + align:start position:0% +the asmp tootes or lie along the ASM +tootes + + align:start position:0% +tootes + + + align:start position:0% +tootes +and look like + + align:start position:0% + + + + align:start position:0% + +this and in fact if we keep track of the + + align:start position:0% +this and in fact if we keep track of the + + + align:start position:0% +this and in fact if we keep track of the +arithmetic involved if this is + + align:start position:0% +arithmetic involved if this is + + + align:start position:0% +arithmetic involved if this is +60° uh and this point is minus1 over to + + align:start position:0% +60° uh and this point is minus1 over to + + + align:start position:0% +60° uh and this point is minus1 over to +then the + + align:start position:0% +then the + + + align:start position:0% +then the +this Branch crosses in the right into + + align:start position:0% +this Branch crosses in the right into + + + align:start position:0% +this Branch crosses in the right into +the right half plane at S = Plus J Ric 3 + + align:start position:0% +the right half plane at S = Plus J Ric 3 + + + align:start position:0% +the right half plane at S = Plus J Ric 3 +over to since this angle is + + align:start position:0% + + + + align:start position:0% + +60° we can also use as an aid to + + align:start position:0% +60° we can also use as an aid to + + + align:start position:0% +60° we can also use as an aid to +constructing more accurate root Locus + + align:start position:0% +constructing more accurate root Locus + + + align:start position:0% +constructing more accurate root Locus +diagrams if we feel the need to do that + + align:start position:0% +diagrams if we feel the need to do that + + + align:start position:0% +diagrams if we feel the need to do that +some rather simple arithmetic + + align:start position:0% +some rather simple arithmetic + + + align:start position:0% +some rather simple arithmetic +calculations and I'd like to illustrate + + align:start position:0% +calculations and I'd like to illustrate + + + align:start position:0% +calculations and I'd like to illustrate +that in closing let's consider an AF ofs + + align:start position:0% +that in closing let's consider an AF ofs + + + align:start position:0% +that in closing let's consider an AF ofs +F of s that includes three poles in + + align:start position:0% +F of s that includes three poles in + + + align:start position:0% +F of s that includes three poles in +particular we have a fnot over three + + align:start position:0% +particular we have a fnot over three + + + align:start position:0% +particular we have a fnot over three +real axis poles one located with a time + + align:start position:0% +real axis poles one located with a time + + + align:start position:0% +real axis poles one located with a time +constant of 1 second in other words at s + + align:start position:0% +constant of 1 second in other words at s + + + align:start position:0% +constant of 1 second in other words at s +equal minus1 another one located with a + + align:start position:0% +equal minus1 another one located with a + + + align:start position:0% +equal minus1 another one located with a +time constant of a half a second at s + + align:start position:0% +time constant of a half a second at s + + + align:start position:0% +time constant of a half a second at s +equal min-2 and finally the third real + + align:start position:0% +equal min-2 and finally the third real + + + align:start position:0% +equal min-2 and finally the third real +axis pole with a with a time constant of + + align:start position:0% +axis pole with a with a time constant of + + + align:start position:0% +axis pole with a with a time constant of +a tenth of a second located at s equal + + align:start position:0% +a tenth of a second located at s equal + + + align:start position:0% +a tenth of a second located at s equal +minus1 and I have that one done + + align:start position:0% + + + + align:start position:0% + +so fairly + + align:start position:0% + + + + align:start position:0% + +accurately here in other words we show + + align:start position:0% +accurately here in other words we show + + + align:start position:0% +accurately here in other words we show +the loop transmission pole locations at + + align:start position:0% +the loop transmission pole locations at + + + align:start position:0% +the loop transmission pole locations at +s equal minus1 s = -2 and S = -10 we've + + align:start position:0% +s equal minus1 s = -2 and S = -10 we've + + + align:start position:0% +s equal minus1 s = -2 and S = -10 we've +already looked at some of the features + + align:start position:0% +already looked at some of the features + + + align:start position:0% +already looked at some of the features +of this sort of a diagram uh in + + align:start position:0% +of this sort of a diagram uh in + + + align:start position:0% +of this sort of a diagram uh in +particular branches exist between these + + align:start position:0% +particular branches exist between these + + + align:start position:0% +particular branches exist between these +two poles uh and to the left of the + + align:start position:0% +two poles uh and to the left of the + + + align:start position:0% +two poles uh and to the left of the +third Loop transmission pole the asmm + + align:start position:0% +third Loop transmission pole the asmm + + + align:start position:0% +third Loop transmission pole the asmm +tootes are at plus andus 60° and at + + align:start position:0% +tootes are at plus andus 60° and at + + + align:start position:0% +tootes are at plus andus 60° and at +180° uh for this particular case the ASM + + align:start position:0% +180° uh for this particular case the ASM + + + align:start position:0% +180° uh for this particular case the ASM +tootes intersect the real axis at Min -1 + + align:start position:0% +tootes intersect the real axis at Min -1 + + + align:start position:0% +tootes intersect the real axis at Min -1 +-2 that that gives us minus 3 and + + align:start position:0% +-2 that that gives us minus 3 and + + + align:start position:0% +-2 that that gives us minus 3 and +another minus 10 in other words + + align:start position:0% +another minus 10 in other words + + + align:start position:0% +another minus 10 in other words +-3 divided by the number of poles which + + align:start position:0% +-3 divided by the number of poles which + + + align:start position:0% +-3 divided by the number of poles which +is three so the ASM tootes intersect the + + align:start position:0% +is three so the ASM tootes intersect the + + + align:start position:0% +is three so the ASM tootes intersect the +real axis + + align:start position:0% +real axis + + + align:start position:0% +real axis +at -4 and + + align:start position:0% + + + + align:start position:0% + +A3 and using that information we can + + align:start position:0% +A3 and using that information we can + + + align:start position:0% +A3 and using that information we can +begin to sketch the behavior of our root + + align:start position:0% +begin to sketch the behavior of our root + + + align:start position:0% +begin to sketch the behavior of our root +Locus + + align:start position:0% +Locus + + + align:start position:0% +Locus +diagram note that if we totally ignore + + align:start position:0% +diagram note that if we totally ignore + + + align:start position:0% +diagram note that if we totally ignore +the third pole we have this rule that + + align:start position:0% +the third pole we have this rule that + + + align:start position:0% +the third pole we have this rule that +says we can ignore remote poles and + + align:start position:0% +says we can ignore remote poles and + + + align:start position:0% +says we can ignore remote poles and +zeros when we're interested in the + + align:start position:0% +zeros when we're interested in the + + + align:start position:0% +zeros when we're interested in the +behavior near the origin if we totally + + align:start position:0% +behavior near the origin if we totally + + + align:start position:0% +behavior near the origin if we totally +ignore the third pole we'd anticipate + + align:start position:0% +ignore the third pole we'd anticipate + + + align:start position:0% +ignore the third pole we'd anticipate +that Breakaway would occur at the + + align:start position:0% +that Breakaway would occur at the + + + align:start position:0% +that Breakaway would occur at the +arithmetic mean of the location of these + + align:start position:0% +arithmetic mean of the location of these + + + align:start position:0% +arithmetic mean of the location of these +two Loop transmission poles that's what + + align:start position:0% +two Loop transmission poles that's what + + + align:start position:0% +two Loop transmission poles that's what +happens in only the two- pole + + align:start position:0% +happens in only the two- pole + + + align:start position:0% +happens in only the two- pole +case uh that would tell us that + + align:start position:0% +case uh that would tell us that + + + align:start position:0% +case uh that would tell us that +Breakaway would occur at minus + + align:start position:0% +Breakaway would occur at minus + + + align:start position:0% +Breakaway would occur at minus +1.5 on the negative real axis if we + + align:start position:0% +1.5 on the negative real axis if we + + + align:start position:0% +1.5 on the negative real axis if we +actually do a an exact calculation of + + align:start position:0% +actually do a an exact calculation of + + + align:start position:0% +actually do a an exact calculation of +the Breakaway point we find that it + + align:start position:0% +the Breakaway point we find that it + + + align:start position:0% +the Breakaway point we find that it +really occurs at minus + + align:start position:0% +really occurs at minus + + + align:start position:0% +really occurs at minus +1.47 so in this particular system where + + align:start position:0% +1.47 so in this particular system where + + + align:start position:0% +1.47 so in this particular system where +we have two poles located within a + + align:start position:0% +we have two poles located within a + + + align:start position:0% +we have two poles located within a +distance of two units of the origin a + + align:start position:0% +distance of two units of the origin a + + + align:start position:0% +distance of two units of the origin a +third Pole located 10 units from the + + align:start position:0% +third Pole located 10 units from the + + + align:start position:0% +third Pole located 10 units from the +origin we find out that we could predict + + align:start position:0% +origin we find out that we could predict + + + align:start position:0% +origin we find out that we could predict +Breakaway very accurately totally + + align:start position:0% +Breakaway very accurately totally + + + align:start position:0% +Breakaway very accurately totally +ignoring the third + + align:start position:0% +ignoring the third + + + align:start position:0% +ignoring the third +pole we can get some other important + + align:start position:0% +pole we can get some other important + + + align:start position:0% +pole we can get some other important +features of the diagram if we're + + align:start position:0% +features of the diagram if we're + + + align:start position:0% +features of the diagram if we're +interested in that by using rather + + align:start position:0% +interested in that by using rather + + + align:start position:0% +interested in that by using rather +simple numerical techniques for example + + align:start position:0% +simple numerical techniques for example + + + align:start position:0% +simple numerical techniques for example +we talked about Ralph or the Ralph + + align:start position:0% +we talked about Ralph or the Ralph + + + align:start position:0% +we talked about Ralph or the Ralph +Criterion last time and we found that + + align:start position:0% +Criterion last time and we found that + + + align:start position:0% +Criterion last time and we found that +that was a a rather simple numerical + + align:start position:0% +that was a a rather simple numerical + + + align:start position:0% +that was a a rather simple numerical +method that would allow us to determine + + align:start position:0% +method that would allow us to determine + + + align:start position:0% +method that would allow us to determine +the number of closed loop poles of the + + align:start position:0% +the number of closed loop poles of the + + + align:start position:0% +the number of closed loop poles of the +transfer function fun in the right half + + align:start position:0% +transfer function fun in the right half + + + align:start position:0% +transfer function fun in the right half +plane another way to use that as I + + align:start position:0% +plane another way to use that as I + + + align:start position:0% +plane another way to use that as I +indicate in the book and I believe you + + align:start position:0% +indicate in the book and I believe you + + + align:start position:0% +indicate in the book and I believe you +tried with with some of the homework + + align:start position:0% +tried with with some of the homework + + + align:start position:0% +tried with with some of the homework +problems last time is to determine for + + align:start position:0% +problems last time is to determine for + + + align:start position:0% +problems last time is to determine for +example what value of a fot will result + + align:start position:0% +example what value of a fot will result + + + align:start position:0% +example what value of a fot will result +in a complex conjugate pair of poles + + align:start position:0% +in a complex conjugate pair of poles + + + align:start position:0% +in a complex conjugate pair of poles +lying on the imaginary axis if we do + + align:start position:0% +lying on the imaginary axis if we do + + + align:start position:0% +lying on the imaginary axis if we do +that development we can determine the + + align:start position:0% +that development we can determine the + + + align:start position:0% +that development we can determine the +value of a fnot which gets the closed + + align:start position:0% +value of a fnot which gets the closed + + + align:start position:0% +value of a fnot which gets the closed +loop poles to these two points and + + align:start position:0% +loop poles to these two points and + + + align:start position:0% +loop poles to these two points and +furthermore we can also determine the + + align:start position:0% +furthermore we can also determine the + + + align:start position:0% +furthermore we can also determine the +imaginary component when the poles cross + + align:start position:0% +imaginary component when the poles cross + + + align:start position:0% +imaginary component when the poles cross +into the right half plane and we perform + + align:start position:0% +into the right half plane and we perform + + + align:start position:0% +into the right half plane and we perform +that calculation we find that these + + align:start position:0% +that calculation we find that these + + + align:start position:0% +that calculation we find that these +branches cross into the right half plane + + align:start position:0% +branches cross into the right half plane + + + align:start position:0% +branches cross into the right half plane +at points plus and minus J + + align:start position:0% +at points plus and minus J + + + align:start position:0% +at points plus and minus J +5.65 furthermore the value of a FN + + align:start position:0% +5.65 furthermore the value of a FN + + + align:start position:0% +5.65 furthermore the value of a FN +necessary to get a pair of complex + + align:start position:0% +necessary to get a pair of complex + + + align:start position:0% +necessary to get a pair of complex +conjugate poles in the right half plane + + align:start position:0% +conjugate poles in the right half plane + + + align:start position:0% +conjugate poles in the right half plane +in other words to make this third order + + align:start position:0% +in other words to make this third order + + + align:start position:0% +in other words to make this third order +system unstable is an a f value of + + align:start position:0% +system unstable is an a f value of + + + align:start position:0% +system unstable is an a f value of +19.8 we can also uh use rather simple + + align:start position:0% +19.8 we can also uh use rather simple + + + align:start position:0% +19.8 we can also uh use rather simple +algebraic manipulations to determine + + align:start position:0% +algebraic manipulations to determine + + + align:start position:0% +algebraic manipulations to determine +other important features of the diagram + + align:start position:0% +other important features of the diagram + + + align:start position:0% +other important features of the diagram +or as a design aid for example we might + + align:start position:0% +or as a design aid for example we might + + + align:start position:0% +or as a design aid for example we might +we recognize that we have one degree of + + align:start position:0% +we recognize that we have one degree of + + + align:start position:0% +we recognize that we have one degree of +freedom in this particular development + + align:start position:0% +freedom in this particular development + + + align:start position:0% +freedom in this particular development +the only thing we're able to control is + + align:start position:0% +the only thing we're able to control is + + + align:start position:0% +the only thing we're able to control is +the a FN product we're constructing the + + align:start position:0% +the a FN product we're constructing the + + + align:start position:0% +the a FN product we're constructing the +root Locust diagram as a function of a + + align:start position:0% +root Locust diagram as a function of a + + + align:start position:0% +root Locust diagram as a function of a +FN and that's the single degree of + + align:start position:0% +FN and that's the single degree of + + + align:start position:0% +FN and that's the single degree of +Freedom that we have so we might be able + + align:start position:0% +Freedom that we have so we might be able + + + align:start position:0% +Freedom that we have so we might be able +to we expect that we'd be able to + + align:start position:0% +to we expect that we'd be able to + + + align:start position:0% +to we expect that we'd be able to +control one feature of the closed loop + + align:start position:0% +control one feature of the closed loop + + + align:start position:0% +control one feature of the closed loop +response for example uh we might choose + + align:start position:0% +response for example uh we might choose + + + align:start position:0% +response for example uh we might choose +to fix the location of the real axis + + align:start position:0% +to fix the location of the real axis + + + align:start position:0% +to fix the location of the real axis +closed loop pole that's not a + + align:start position:0% +closed loop pole that's not a + + + align:start position:0% +closed loop pole that's not a +particularly useful constraint but it's + + align:start position:0% +particularly useful constraint but it's + + + align:start position:0% +particularly useful constraint but it's +at least one + + align:start position:0% +at least one + + + align:start position:0% +at least one +possibility another one which is + + align:start position:0% +possibility another one which is + + + align:start position:0% +possibility another one which is +probably a more useful constraint might + + align:start position:0% +probably a more useful constraint might + + + align:start position:0% +probably a more useful constraint might +be to exercise our one degree of freedom + + align:start position:0% +be to exercise our one degree of freedom + + + align:start position:0% +be to exercise our one degree of freedom +in order to set the damping ratio of the + + align:start position:0% +in order to set the damping ratio of the + + + align:start position:0% +in order to set the damping ratio of the +complex conjugate pole pair in other + + align:start position:0% +complex conjugate pole pair in other + + + align:start position:0% +complex conjugate pole pair in other +words we recognize that as we increase a + + align:start position:0% +words we recognize that as we increase a + + + align:start position:0% +words we recognize that as we increase a +FN our closed loop poles Move Along + + align:start position:0% +FN our closed loop poles Move Along + + + align:start position:0% +FN our closed loop poles Move Along +these branches and suppose that I would + + align:start position:0% +these branches and suppose that I would + + + align:start position:0% +these branches and suppose that I would +like to design for a given damping ratio + + align:start position:0% +like to design for a given damping ratio + + + align:start position:0% +like to design for a given damping ratio +associated with the Clos Loop pole pair + + align:start position:0% +associated with the Clos Loop pole pair + + + align:start position:0% +associated with the Clos Loop pole pair +these this closed loop pole pair + + align:start position:0% +these this closed loop pole pair + + + align:start position:0% +these this closed loop pole pair +certainly dominates performance since + + align:start position:0% +certainly dominates performance since + + + align:start position:0% +certainly dominates performance since +it's the pole pair closest to the + + align:start position:0% +it's the pole pair closest to the + + + align:start position:0% +it's the pole pair closest to the +imaginary Axis or closest to the origin + + align:start position:0% +imaginary Axis or closest to the origin + + + align:start position:0% +imaginary Axis or closest to the origin +and much closer than the Third + + align:start position:0% +and much closer than the Third + + + align:start position:0% +and much closer than the Third +well what we can do is write the + + align:start position:0% +well what we can do is write the + + + align:start position:0% +well what we can do is write the +polinomial the characteristic equation + + align:start position:0% +polinomial the characteristic equation + + + align:start position:0% +polinomial the characteristic equation +of the closed loop transfer function and + + align:start position:0% +of the closed loop transfer function and + + + align:start position:0% +of the closed loop transfer function and +if for example we'd like to set up for a + + align:start position:0% +if for example we'd like to set up for a + + + align:start position:0% +if for example we'd like to set up for a +damping ratio of 0.5 in other words + + align:start position:0% +damping ratio of 0.5 in other words + + + align:start position:0% +damping ratio of 0.5 in other words +these branches 60° from the real axis + + align:start position:0% +these branches 60° from the real axis + + + align:start position:0% +these branches 60° from the real axis +that implies a given relationship among + + align:start position:0% +that implies a given relationship among + + + align:start position:0% +that implies a given relationship among +the coefficients of the characteristic + + align:start position:0% +the coefficients of the characteristic + + + align:start position:0% +the coefficients of the characteristic +equation and we can use rather simple + + align:start position:0% +equation and we can use rather simple + + + align:start position:0% +equation and we can use rather simple +algebraic manipulations to determine the + + align:start position:0% +algebraic manipulations to determine the + + + align:start position:0% +algebraic manipulations to determine the +value of a FN that matches those + + align:start position:0% +value of a FN that matches those + + + align:start position:0% +value of a FN that matches those +conditions I I do that in the book when + + align:start position:0% +conditions I I do that in the book when + + + align:start position:0% +conditions I I do that in the book when +we go through that development we find + + align:start position:0% +we go through that development we find + + + align:start position:0% +we go through that development we find +out that this + + align:start position:0% +out that this + + + align:start position:0% +out that this +system has a closed loop damping ratio + + align:start position:0% +system has a closed loop damping ratio + + + align:start position:0% +system has a closed loop damping ratio +for the dominant pole pair of 0.5 for an + + align:start position:0% +for the dominant pole pair of 0.5 for an + + + align:start position:0% +for the dominant pole pair of 0.5 for an +a fnot of only + + align:start position:0% +a fnot of only + + + align:start position:0% +a fnot of only +2.2 so in this particular system we find + + align:start position:0% +2.2 so in this particular system we find + + + align:start position:0% +2.2 so in this particular system we find +out that if we'd like to maintain a + + align:start position:0% +out that if we'd like to maintain a + + + align:start position:0% +out that if we'd like to maintain a +reasonable amount of damping where + + align:start position:0% +reasonable amount of damping where + + + align:start position:0% +reasonable amount of damping where +reasonable amount of damping might be a + + align:start position:0% +reasonable amount of damping might be a + + + align:start position:0% +reasonable amount of damping might be a +damping ratio for the dominant pole pair + + align:start position:0% +damping ratio for the dominant pole pair + + + align:start position:0% +damping ratio for the dominant pole pair +of greater than than 0.5 we can only + + align:start position:0% +of greater than than 0.5 we can only + + + align:start position:0% +of greater than than 0.5 we can only +achieve an A F product of 2.2 or a + + align:start position:0% +achieve an A F product of 2.2 or a + + + align:start position:0% +achieve an A F product of 2.2 or a +desensitivity by our original definition + + align:start position:0% +desensitivity by our original definition + + + align:start position:0% +desensitivity by our original definition +of + + align:start position:0% +of + + + align:start position:0% +of +3.2 next time we'll look from a root + + align:start position:0% +3.2 next time we'll look from a root + + + align:start position:0% +3.2 next time we'll look from a root +Locust Point of View at how we might be + + align:start position:0% +Locust Point of View at how we might be + + + align:start position:0% +Locust Point of View at how we might be +able to improve that situation what + + align:start position:0% +able to improve that situation what + + + align:start position:0% +able to improve that situation what +should we do to certain kinds of + + align:start position:0% +should we do to certain kinds of + + + align:start position:0% +should we do to certain kinds of +feedback systems in order to increase + + align:start position:0% +feedback systems in order to increase + + + align:start position:0% +feedback systems in order to increase +the desensitivity we can obtain before + + align:start position:0% +the desensitivity we can obtain before + + + align:start position:0% +the desensitivity we can obtain before +we reach a given degree of instability + + align:start position:0% +we reach a given degree of instability + + + align:start position:0% +we reach a given degree of instability +thank you \ No newline at end of file diff --git a/BK1afo-GMag.txt b/BK1afo-GMag.txt new file mode 100644 index 0000000000000000000000000000000000000000..bdd981953e95f9fa056dd8e89cfa6e42dd9ec9e8 --- /dev/null +++ b/BK1afo-GMag.txt @@ -0,0 +1,7211 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu the thing we have to talk + + align:start position:0% +ocw.mit.edu the thing we have to talk + + + align:start position:0% +ocw.mit.edu the thing we have to talk +about here is multicellular + + align:start position:0% +about here is multicellular + + + align:start position:0% +about here is multicellular +life cells although we can think of them + + align:start position:0% +life cells although we can think of them + + + align:start position:0% +life cells although we can think of them +as + + align:start position:0% +as + + + align:start position:0% +as +entities are generally not the unit of a + + align:start position:0% +entities are generally not the unit of a + + + align:start position:0% +entities are generally not the unit of a +whole organism there are many organisms + + align:start position:0% +whole organism there are many organisms + + + align:start position:0% +whole organism there are many organisms +whose unit is a single cell but the + + align:start position:0% +whose unit is a single cell but the + + + align:start position:0% +whose unit is a single cell but the +really interesting ones are the ones + + align:start position:0% +really interesting ones are the ones + + + align:start position:0% +really interesting ones are the ones +that have got lots of + + align:start position:0% +that have got lots of + + + align:start position:0% +that have got lots of +cells and so life has developed in a way + + align:start position:0% +cells and so life has developed in a way + + + align:start position:0% +cells and so life has developed in a way +that most organisms are multicellular + + align:start position:0% + + + + align:start position:0% + +and we can pose the question of why that + + align:start position:0% +and we can pose the question of why that + + + align:start position:0% +and we can pose the question of why that +might be you know my trite phrase well + + align:start position:0% +might be you know my trite phrase well + + + align:start position:0% +might be you know my trite phrase well +it's more interesting is actually a very + + align:start position:0% +it's more interesting is actually a very + + + align:start position:0% +it's more interesting is actually a very +poor answer there's a much better answer + + align:start position:0% +poor answer there's a much better answer + + + align:start position:0% +poor answer there's a much better answer +and that is if you have something made + + align:start position:0% +and that is if you have something made + + + align:start position:0% +and that is if you have something made +of lots of cells different parts of that + + align:start position:0% +of lots of cells different parts of that + + + align:start position:0% +of lots of cells different parts of that +organism can specialize and do different + + align:start position:0% +organism can specialize and do different + + + align:start position:0% +organism can specialize and do different +things and so you can get a + + align:start position:0% +things and so you can get a + + + align:start position:0% +things and so you can get a +diversification of function with which + + align:start position:0% +diversification of function with which + + + align:start position:0% +diversification of function with which +allows the organism to colonize new + + align:start position:0% +allows the organism to colonize new + + + align:start position:0% +allows the organism to colonize new +parts of the earth interact with its + + align:start position:0% +parts of the earth interact with its + + + align:start position:0% +parts of the earth interact with its +environment in different ways interact + + align:start position:0% +environment in different ways interact + + + align:start position:0% +environment in different ways interact +with other members of its species in + + align:start position:0% +with other members of its species in + + + align:start position:0% +with other members of its species in +different ways and it does become allow + + align:start position:0% +different ways and it does become allow + + + align:start position:0% +different ways and it does become allow +a much greater complexity of life so I + + align:start position:0% +a much greater complexity of life so I + + + align:start position:0% +a much greater complexity of life so I +would say the answer I would give you is + + align:start position:0% +would say the answer I would give you is + + + align:start position:0% +would say the answer I would give you is +it allows new + + align:start position:0% + + + + align:start position:0% + +functions to + + align:start position:0% + + + + align:start position:0% + +evolve and greater + + align:start position:0% +evolve and greater + + + align:start position:0% +evolve and greater +complexity of life to + + align:start position:0% + + + + align:start position:0% + +develop if we consider the human + + align:start position:0% + + + + align:start position:0% + +adult and look and see what we're made + + align:start position:0% +adult and look and see what we're made + + + align:start position:0% +adult and look and see what we're made +of we contain about 400 different kinds + + align:start position:0% +of we contain about 400 different kinds + + + align:start position:0% +of we contain about 400 different kinds +of + + align:start position:0% +of + + + align:start position:0% +of +cells we can call those cell types + + align:start position:0% + + + + align:start position:0% + +where each cell + + align:start position:0% +where each cell + + + align:start position:0% +where each cell +type has a specialized + + align:start position:0% + + + + align:start position:0% + +function those + + align:start position:0% +function those + + + align:start position:0% +function those +cells are organized together and they're + + align:start position:0% +cells are organized together and they're + + + align:start position:0% +cells are organized together and they're +located in specific + + align:start position:0% +located in specific + + + align:start position:0% +located in specific +places so the cell types are organized + + align:start position:0% + + + + align:start position:0% + +into + + align:start position:0% + + + + align:start position:0% + +groups they are organized into + + align:start position:0% +groups they are organized into + + + align:start position:0% +groups they are organized into +three-dimensional structures one of the + + align:start position:0% +three-dimensional structures one of the + + + align:start position:0% +three-dimensional structures one of the +things that is most interesting about + + align:start position:0% +things that is most interesting about + + + align:start position:0% +things that is most interesting about +living organisms is that they're + + align:start position:0% +living organisms is that they're + + + align:start position:0% +living organisms is that they're +3D think of it if we were all sitting + + align:start position:0% +3D think of it if we were all sitting + + + align:start position:0% +3D think of it if we were all sitting +there as flat sheets you know you get + + align:start position:0% +there as flat sheets you know you get + + + align:start position:0% +there as flat sheets you know you get +the idea the 3D is + + align:start position:0% +the idea the 3D is + + + align:start position:0% +the idea the 3D is +extraordinary and it's one of the things + + align:start position:0% +extraordinary and it's one of the things + + + align:start position:0% +extraordinary and it's one of the things +that being multicellular allows you to + + align:start position:0% +that being multicellular allows you to + + + align:start position:0% +that being multicellular allows you to +do so cells are organized into groups + + align:start position:0% +do so cells are organized into groups + + + align:start position:0% +do so cells are organized into groups +they are organized into 3D + + align:start position:0% + + + + align:start position:0% + +structures and this notion of groups of + + align:start position:0% +structures and this notion of groups of + + + align:start position:0% +structures and this notion of groups of +cells and + + align:start position:0% +cells and + + + align:start position:0% +cells and +structures is that they work together + + align:start position:0% +structures is that they work together + + + align:start position:0% +structures is that they work together +groups of cells arranged in a certain + + align:start position:0% +groups of cells arranged in a certain + + + align:start position:0% +groups of cells arranged in a certain +way work together to form a a ho an + + align:start position:0% +way work together to form a a ho an + + + align:start position:0% +way work together to form a a ho an +organ that has got an even greater + + align:start position:0% +organ that has got an even greater + + + align:start position:0% +organ that has got an even greater +specialized + + align:start position:0% +specialized + + + align:start position:0% +specialized +function so these work together + + align:start position:0% + + + + align:start position:0% + +to make + + align:start position:0% +to make + + + align:start position:0% +to make +organs and in particular as we'll talk + + align:start position:0% +organs and in particular as we'll talk + + + align:start position:0% +organs and in particular as we'll talk +about next time it's the groups of cells + + align:start position:0% +about next time it's the groups of cells + + + align:start position:0% +about next time it's the groups of cells +and their 3D structures which makes the + + align:start position:0% +and their 3D structures which makes the + + + align:start position:0% +and their 3D structures which makes the +organs and the organs themselves can be + + align:start position:0% +organs and the organs themselves can be + + + align:start position:0% +organs and the organs themselves can be +organized into Super structures called + + align:start position:0% +organized into Super structures called + + + align:start position:0% +organized into Super structures called +organ + + align:start position:0% + + + + align:start position:0% + +systems and we'll work on all of these + + align:start position:0% +systems and we'll work on all of these + + + align:start position:0% +systems and we'll work on all of these +things over the next couple of + + align:start position:0% +things over the next couple of + + + align:start position:0% +things over the next couple of +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +today we're going to talk about cell + + align:start position:0% +today we're going to talk about cell + + + align:start position:0% +today we're going to talk about cell +type + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +is before I'm I'm thinking if I should + + align:start position:0% +is before I'm I'm thinking if I should + + + align:start position:0% +is before I'm I'm thinking if I should +show you a slide first or if I should + + align:start position:0% +show you a slide first or if I should + + + align:start position:0% +show you a slide first or if I should +write this on the board let me show you + + align:start position:0% +write this on the board let me show you + + + align:start position:0% +write this on the board let me show you +a slide first because I want these next + + align:start position:0% +a slide first because I want these next + + + align:start position:0% +a slide first because I want these next +two boards to follow one from another + + align:start position:0% +two boards to follow one from another + + + align:start position:0% +two boards to follow one from another +all + + align:start position:0% +all + + + align:start position:0% +all +right different cells oh oh there we go + + align:start position:0% + + + + align:start position:0% + +okay different cell types these are + + align:start position:0% +okay different cell types these are + + + align:start position:0% +okay different cell types these are +micrographs of different cell types here + + align:start position:0% +micrographs of different cell types here + + + align:start position:0% +micrographs of different cell types here +are red blood cells which regulate + + align:start position:0% +are red blood cells which regulate + + + align:start position:0% +are red blood cells which regulate +oxygen transport spatar involved in rep + + align:start position:0% +oxygen transport spatar involved in rep + + + align:start position:0% +oxygen transport spatar involved in rep +reproduction and neurons involved in + + align:start position:0% +reproduction and neurons involved in + + + align:start position:0% +reproduction and neurons involved in +communication each of them has got the + + align:start position:0% +communication each of them has got the + + + align:start position:0% +communication each of them has got the +basic cellular functions that we've + + align:start position:0% +basic cellular functions that we've + + + align:start position:0% +basic cellular functions that we've +talked about over the last lectures but + + align:start position:0% +talked about over the last lectures but + + + align:start position:0% +talked about over the last lectures but +each of them is obviously + + align:start position:0% +each of them is obviously + + + align:start position:0% +each of them is obviously +morphologically different they look + + align:start position:0% +morphologically different they look + + + align:start position:0% +morphologically different they look +different and they carry out different + + align:start position:0% +different and they carry out different + + + align:start position:0% +different and they carry out different +functions the cell types get organized + + align:start position:0% +functions the cell types get organized + + + align:start position:0% +functions the cell types get organized +in specific ways this is a really really + + align:start position:0% +in specific ways this is a really really + + + align:start position:0% +in specific ways this is a really really +extraordinary example which is the + + align:start position:0% +extraordinary example which is the + + + align:start position:0% +extraordinary example which is the +retina of your eye the light sensitive + + align:start position:0% +retina of your eye the light sensitive + + + align:start position:0% +retina of your eye the light sensitive +part of your eye which contains a number + + align:start position:0% +part of your eye which contains a number + + + align:start position:0% +part of your eye which contains a number +of different kinds of cells and these + + align:start position:0% +of different kinds of cells and these + + + align:start position:0% +of different kinds of cells and these +cells are organized in layers and so + + align:start position:0% +cells are organized in layers and so + + + align:start position:0% +cells are organized in layers and so +they're colorcoded here and you can see + + align:start position:0% +they're colorcoded here and you can see + + + align:start position:0% +they're colorcoded here and you can see +the different layers are grouped + + align:start position:0% +the different layers are grouped + + + align:start position:0% +the different layers are grouped +together but then the different layers + + align:start position:0% +together but then the different layers + + + align:start position:0% +together but then the different layers +communicate with one + + align:start position:0% +communicate with one + + + align:start position:0% +communicate with one +another and this communication and this + + align:start position:0% +another and this communication and this + + + align:start position:0% +another and this communication and this +organization is key you can have all the + + align:start position:0% +organization is key you can have all the + + + align:start position:0% +organization is key you can have all the +different cell types in the retina but + + align:start position:0% +different cell types in the retina but + + + align:start position:0% +different cell types in the retina but +if they're not arranged in this rigid + + align:start position:0% +if they're not arranged in this rigid + + + align:start position:0% +if they're not arranged in this rigid +structure or in this specific structure + + align:start position:0% +structure or in this specific structure + + + align:start position:0% +structure or in this specific structure +the retina doesn't + + align:start position:0% +the retina doesn't + + + align:start position:0% +the retina doesn't +function 3D structures we'll talk next + + align:start position:0% +function 3D structures we'll talk next + + + align:start position:0% +function 3D structures we'll talk next +time about engineering structure out of + + align:start position:0% +time about engineering structure out of + + + align:start position:0% +time about engineering structure out of +cells and the heart is one thing you + + align:start position:0% +cells and the heart is one thing you + + + align:start position:0% +cells and the heart is one thing you +have to think about engineering the only + + align:start position:0% +have to think about engineering the only + + + align:start position:0% +have to think about engineering the only +raw material that you have to use for + + align:start position:0% +raw material that you have to use for + + + align:start position:0% +raw material that you have to use for +the engineering is cells and so how do + + align:start position:0% +the engineering is cells and so how do + + + align:start position:0% +the engineering is cells and so how do +you get something that looks like a + + align:start position:0% +you get something that looks like a + + + align:start position:0% +you get something that looks like a +human heart and carries out the + + align:start position:0% +human heart and carries out the + + + align:start position:0% +human heart and carries out the +exquisitely regulated pumping function + + align:start position:0% +exquisitely regulated pumping function + + + align:start position:0% +exquisitely regulated pumping function +of the heart + + align:start position:0% +of the heart + + + align:start position:0% +of the heart +and here's another one that I'll touch + + align:start position:0% +and here's another one that I'll touch + + + align:start position:0% +and here's another one that I'll touch +on which is the question of + + align:start position:0% +on which is the question of + + + align:start position:0% +on which is the question of +position it's not that we just are made + + align:start position:0% +position it's not that we just are made + + + align:start position:0% +position it's not that we just are made +up of lots of different kinds of cells + + align:start position:0% +up of lots of different kinds of cells + + + align:start position:0% +up of lots of different kinds of cells +that are grouped together in organs it's + + align:start position:0% +that are grouped together in organs it's + + + align:start position:0% +that are grouped together in organs it's +that they're also positioned in the + + align:start position:0% +that they're also positioned in the + + + align:start position:0% +that they're also positioned in the +correct place and in this plasticized + + align:start position:0% +correct place and in this plasticized + + + align:start position:0% +correct place and in this plasticized +human actually I think it's a fully + + align:start position:0% +human actually I think it's a fully + + + align:start position:0% +human actually I think it's a fully +plastic human if you open up the cavity + + align:start position:0% +plastic human if you open up the cavity + + + align:start position:0% +plastic human if you open up the cavity +and look into the abdomen you can see + + align:start position:0% +and look into the abdomen you can see + + + align:start position:0% +and look into the abdomen you can see +these organs that are arranged packed so + + align:start position:0% +these organs that are arranged packed so + + + align:start position:0% +these organs that are arranged packed so +beautifully like this it's no accident + + align:start position:0% +beautifully like this it's no accident + + + align:start position:0% +beautifully like this it's no accident +they get there because they're told to + + align:start position:0% +they get there because they're told to + + + align:start position:0% +they get there because they're told to +get there there is a process that + + align:start position:0% +get there there is a process that + + + align:start position:0% +get there there is a process that +positions the organs in the precise way + + align:start position:0% +positions the organs in the precise way + + + align:start position:0% +positions the organs in the precise way +and if they're positioned incorrectly + + align:start position:0% +and if they're positioned incorrectly + + + align:start position:0% +and if they're positioned incorrectly +there are medical consequences which are + + align:start position:0% +there are medical consequences which are + + + align:start position:0% +there are medical consequences which are +very + + align:start position:0% +very + + + align:start position:0% +very +severe all right so all of these things + + align:start position:0% +severe all right so all of these things + + + align:start position:0% +severe all right so all of these things +we need to think about but let's go back + + align:start position:0% +we need to think about but let's go back + + + align:start position:0% +we need to think about but let's go back +to the board and you will recognize this + + align:start position:0% +to the board and you will recognize this + + + align:start position:0% +to the board and you will recognize this +diagram which is pivotal for what we're + + align:start position:0% +diagram which is pivotal for what we're + + + align:start position:0% +diagram which is pivotal for what we're +going to talk about + + align:start position:0% +going to talk about + + + align:start position:0% +going to talk about +today here is a mantra that I've + + align:start position:0% +today here is a mantra that I've + + + align:start position:0% +today here is a mantra that I've +mentioned before and you need to know + + align:start position:0% +mentioned before and you need to know + + + align:start position:0% +mentioned before and you need to know +and really need to understand this all + + align:start position:0% +and really need to understand this all + + + align:start position:0% +and really need to understand this all +cells contain the same set of + + align:start position:0% + + + + align:start position:0% + +genes Professor Jax will give you one + + align:start position:0% +genes Professor Jax will give you one + + + align:start position:0% +genes Professor Jax will give you one +exception to this rule but it's the + + align:start position:0% +exception to this rule but it's the + + + align:start position:0% +exception to this rule but it's the +exception all cells in your body body + + align:start position:0% +exception all cells in your body body + + + align:start position:0% +exception all cells in your body body +contain the same set of + + align:start position:0% +contain the same set of + + + align:start position:0% +contain the same set of +genes but not all those genes are used + + align:start position:0% +genes but not all those genes are used + + + align:start position:0% +genes but not all those genes are used +in every cell + + align:start position:0% + + + + align:start position:0% + +type but each cell + + align:start position:0% + + + + align:start position:0% + +type + + align:start position:0% +type + + + align:start position:0% +type +uses and you know the word expresses now + + align:start position:0% +uses and you know the word expresses now + + + align:start position:0% +uses and you know the word expresses now +each cell type + + align:start position:0% +each cell type + + + align:start position:0% +each cell type +expresses a + + align:start position:0% +expresses a + + + align:start position:0% +expresses a +subset and it's a unique sub well let me + + align:start position:0% +subset and it's a unique sub well let me + + + align:start position:0% +subset and it's a unique sub well let me +put unique in parentheses and you'll + + align:start position:0% +put unique in parentheses and you'll + + + align:start position:0% +put unique in parentheses and you'll +you'll see what I mean a unique subset + + align:start position:0% +you'll see what I mean a unique subset + + + align:start position:0% +you'll see what I mean a unique subset +of the + + align:start position:0% + + + + align:start position:0% + +genome and this set of genes and the + + align:start position:0% +genome and this set of genes and the + + + align:start position:0% +genome and this set of genes and the +products of those genes make the cell + + align:start position:0% +products of those genes make the cell + + + align:start position:0% +products of those genes make the cell +type what it + + align:start position:0% + + + + align:start position:0% + +is the products of those genes usually + + align:start position:0% +is the products of those genes usually + + + align:start position:0% +is the products of those genes usually +proteins and some rnas + + align:start position:0% + + + + align:start position:0% + +give the cell type its + + align:start position:0% + + + + align:start position:0% + +function so there are two cories here + + align:start position:0% +function so there are two cories here + + + align:start position:0% +function so there are two cories here +one you have to understand how the + + align:start position:0% +one you have to understand how the + + + align:start position:0% +one you have to understand how the +expression of genes is controlled and + + align:start position:0% +expression of genes is controlled and + + + align:start position:0% +expression of genes is controlled and +that is pivotal to this list and two + + align:start position:0% +that is pivotal to this list and two + + + align:start position:0% +that is pivotal to this list and two +this set of genes that makes each cell + + align:start position:0% +this set of genes that makes each cell + + + align:start position:0% +this set of genes that makes each cell +type the set of active genes that makes + + align:start position:0% +type the set of active genes that makes + + + align:start position:0% +type the set of active genes that makes +each cell type what it is forms a kind + + align:start position:0% +each cell type what it is forms a kind + + + align:start position:0% +each cell type what it is forms a kind +of a combinatorial code for a cell type + + align:start position:0% +of a combinatorial code for a cell type + + + align:start position:0% +of a combinatorial code for a cell type +so let's just write this down so control + + align:start position:0% +so let's just write this down so control + + + align:start position:0% +so let's just write this down so control +of gene expression is + + align:start position:0% + + + + align:start position:0% + +crucial + + align:start position:0% + + + + align:start position:0% + +and there is a combinatorial code of + + align:start position:0% +and there is a combinatorial code of + + + align:start position:0% +and there is a combinatorial code of +gene expression for each cell type + + align:start position:0% + + + + align:start position:0% + +a combinatorial code of expressed + + align:start position:0% + + + + align:start position:0% + +genes for each cell + + align:start position:0% + + + + align:start position:0% + +type you will not find this notion of a + + align:start position:0% +type you will not find this notion of a + + + align:start position:0% +type you will not find this notion of a +combinatorial code in your book but I + + align:start position:0% +combinatorial code in your book but I + + + align:start position:0% +combinatorial code in your book but I +think if you talk to any life scientist + + align:start position:0% +think if you talk to any life scientist + + + align:start position:0% +think if you talk to any life scientist +who's doing research right now they + + align:start position:0% +who's doing research right now they + + + align:start position:0% +who's doing research right now they +would agree that that is the correct way + + align:start position:0% +would agree that that is the correct way + + + align:start position:0% +would agree that that is the correct way +to be thinking about cell type so let's + + align:start position:0% +to be thinking about cell type so let's + + + align:start position:0% +to be thinking about cell type so let's +explore this a bit more and let's write + + align:start position:0% +explore this a bit more and let's write + + + align:start position:0% +explore this a bit more and let's write +out three different cell + + align:start position:0% + + + + align:start position:0% + +types and I'm going to introduce the + + align:start position:0% +types and I'm going to introduce the + + + align:start position:0% +types and I'm going to introduce the +word here self + + align:start position:0% + + + + align:start position:0% + +fate and both cell type and cell fate + + align:start position:0% +fate and both cell type and cell fate + + + align:start position:0% +fate and both cell type and cell fate +can be used interchangeably with the + + align:start position:0% +can be used interchangeably with the + + + align:start position:0% +can be used interchangeably with the +term + + align:start position:0% +term + + + align:start position:0% +term +function and let's pick + + align:start position:0% + + + + align:start position:0% + +neurons + + align:start position:0% + + + + align:start position:0% + +muscle and the epidermis which is the + + align:start position:0% +muscle and the epidermis which is the + + + align:start position:0% +muscle and the epidermis which is the +outer layer of the + + align:start position:0% + + + + align:start position:0% + +skin and let's consider the genes that + + align:start position:0% +skin and let's consider the genes that + + + align:start position:0% +skin and let's consider the genes that +are present in each cell type and let's + + align:start position:0% +are present in each cell type and let's + + + align:start position:0% +are present in each cell type and let's +consider the genes that are expressed in + + align:start position:0% +consider the genes that are expressed in + + + align:start position:0% +consider the genes that are expressed in +each cell + + align:start position:0% + + + + align:start position:0% + +type the genes that are present in each + + align:start position:0% +type the genes that are present in each + + + align:start position:0% +type the genes that are present in each +cell type as I've just told you are the + + align:start position:0% +cell type as I've just told you are the + + + align:start position:0% +cell type as I've just told you are the +same and so + + align:start position:0% +same and so + + + align:start position:0% +same and so +let's make them A B C D and + + align:start position:0% +let's make them A B C D and + + + align:start position:0% +let's make them A B C D and +E and each of those genes is present in + + align:start position:0% +E and each of those genes is present in + + + align:start position:0% +E and each of those genes is present in +each of these cell + + align:start position:0% + + + + align:start position:0% + +types but only some of them are used and + + align:start position:0% +types but only some of them are used and + + + align:start position:0% +types but only some of them are used and +so let's say in the neurons + + align:start position:0% +so let's say in the neurons + + + align:start position:0% +so let's say in the neurons +a B and E are used in muscle a c and d + + align:start position:0% +a B and E are used in muscle a c and d + + + align:start position:0% +a B and E are used in muscle a c and d +and a b and c in + + align:start position:0% +and a b and c in + + + align:start position:0% +and a b and c in +epidermis okay so look at what I've + + align:start position:0% +epidermis okay so look at what I've + + + align:start position:0% +epidermis okay so look at what I've +written there and you can pick out some + + align:start position:0% +written there and you can pick out some + + + align:start position:0% +written there and you can pick out some +patterns you can pick out a gene that is + + align:start position:0% +patterns you can pick out a gene that is + + + align:start position:0% +patterns you can pick out a gene that is +expressed in all of the cell types so + + align:start position:0% +expressed in all of the cell types so + + + align:start position:0% +expressed in all of the cell types so +Gene + + align:start position:0% +Gene + + + align:start position:0% +Gene +a is expressed in all of the cell types + + align:start position:0% +a is expressed in all of the cell types + + + align:start position:0% +a is expressed in all of the cell types +and Gene a exemplifies a gene that we + + align:start position:0% +and Gene a exemplifies a gene that we + + + align:start position:0% +and Gene a exemplifies a gene that we +term ubiquitously expressed sometimes + + align:start position:0% +term ubiquitously expressed sometimes + + + align:start position:0% +term ubiquitously expressed sometimes +termed a housekeeping Gene I really + + align:start position:0% +termed a housekeeping Gene I really + + + align:start position:0% +termed a housekeeping Gene I really +dislike that term but you will see + + align:start position:0% + + + + align:start position:0% + +it so ubiquitously + + align:start position:0% +it so ubiquitously + + + align:start position:0% +it so ubiquitously +expressed maybe you'll see + + align:start position:0% +expressed maybe you'll see + + + align:start position:0% +expressed maybe you'll see +housekeeping you can come to office ours + + align:start position:0% +housekeeping you can come to office ours + + + align:start position:0% +housekeeping you can come to office ours +and I'll tell you why I hate that term + + align:start position:0% +and I'll tell you why I hate that term + + + align:start position:0% +and I'll tell you why I hate that term +and then you can pick out a gene which + + align:start position:0% +and then you can pick out a gene which + + + align:start position:0% +and then you can pick out a gene which +is expressed in some of the cell types + + align:start position:0% +is expressed in some of the cell types + + + align:start position:0% +is expressed in some of the cell types +but not others so let's look at B here + + align:start position:0% +but not others so let's look at B here + + + align:start position:0% +but not others so let's look at B here +has B expressed in the neurons and the + + align:start position:0% +has B expressed in the neurons and the + + + align:start position:0% +has B expressed in the neurons and the +epidermis but not in the + + align:start position:0% +epidermis but not in the + + + align:start position:0% +epidermis but not in the +muscle and B would be referred to and + + align:start position:0% +muscle and B would be referred to and + + + align:start position:0% +muscle and B would be referred to and +actually C is the same way isn't it C is + + align:start position:0% +actually C is the same way isn't it C is + + + align:start position:0% +actually C is the same way isn't it C is +in muscle and + + align:start position:0% + + + + align:start position:0% + +epidermis B and C would be referred to + + align:start position:0% +epidermis B and C would be referred to + + + align:start position:0% +epidermis B and C would be referred to +as genes with restricted + + align:start position:0% +as genes with restricted + + + align:start position:0% +as genes with restricted +expression so B and C would have + + align:start position:0% +expression so B and C would have + + + align:start position:0% +expression so B and C would have +restricted + + align:start position:0% +restricted + + + align:start position:0% +restricted +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +expression and then there's two genes + + align:start position:0% +expression and then there's two genes + + + align:start position:0% +expression and then there's two genes +there + + align:start position:0% +there + + + align:start position:0% +there +e and D which are only expressed in one + + align:start position:0% +e and D which are only expressed in one + + + align:start position:0% +e and D which are only expressed in one +of the their own cell type in neurons or + + align:start position:0% +of the their own cell type in neurons or + + + align:start position:0% +of the their own cell type in neurons or +in + + align:start position:0% +in + + + align:start position:0% +in +muscle so d and e would be cell type + + align:start position:0% +muscle so d and e would be cell type + + + align:start position:0% +muscle so d and e would be cell type +specific + + align:start position:0% + + + + align:start position:0% + +genes and from this simple example you + + align:start position:0% +genes and from this simple example you + + + align:start position:0% +genes and from this simple example you +you can see a number of things firstly + + align:start position:0% +you can see a number of things firstly + + + align:start position:0% +you can see a number of things firstly +you can get a combinatorial code that is + + align:start position:0% +you can get a combinatorial code that is + + + align:start position:0% +you can get a combinatorial code that is +specific for a cell type without any + + align:start position:0% +specific for a cell type without any + + + align:start position:0% +specific for a cell type without any +genes that are specifically expressed in + + align:start position:0% +genes that are specifically expressed in + + + align:start position:0% +genes that are specifically expressed in +the cell type if you look in the + + align:start position:0% +the cell type if you look in the + + + align:start position:0% +the cell type if you look in the +epidermis example A B and C are + + align:start position:0% +epidermis example A B and C are + + + align:start position:0% +epidermis example A B and C are +expressed none of them are cell type + + align:start position:0% +expressed none of them are cell type + + + align:start position:0% +expressed none of them are cell type +specific but nonetheless they give the + + align:start position:0% +specific but nonetheless they give the + + + align:start position:0% +specific but nonetheless they give the +combinatorial code that is the epidermis + + align:start position:0% +combinatorial code that is the epidermis + + + align:start position:0% +combinatorial code that is the epidermis +and then the other examples of each got + + align:start position:0% +and then the other examples of each got + + + align:start position:0% +and then the other examples of each got +a cell type specific + + align:start position:0% +a cell type specific + + + align:start position:0% +a cell type specific +Gene what does a combinatorial code + + align:start position:0% +Gene what does a combinatorial code + + + align:start position:0% +Gene what does a combinatorial code +really look like well to be honest we + + align:start position:0% +really look like well to be honest we + + + align:start position:0% +really look like well to be honest we +don't actually know there's no cell type + + align:start position:0% +don't actually know there's no cell type + + + align:start position:0% +don't actually know there's no cell type +for which the combinatorial code has + + align:start position:0% +for which the combinatorial code has + + + align:start position:0% +for which the combinatorial code has +been worked out but you know now there + + align:start position:0% +been worked out but you know now there + + + align:start position:0% +been worked out but you know now there +are about 20,000 human genes and + + align:start position:0% +are about 20,000 human genes and + + + align:start position:0% +are about 20,000 human genes and +probably about half of them are + + align:start position:0% +probably about half of them are + + + align:start position:0% +probably about half of them are +expressed in most cell types so the + + align:start position:0% +expressed in most cell types so the + + + align:start position:0% +expressed in most cell types so the +combinatorial code for any given cell + + align:start position:0% +combinatorial code for any given cell + + + align:start position:0% +combinatorial code for any given cell +type is going to be thousands and + + align:start position:0% +type is going to be thousands and + + + align:start position:0% +type is going to be thousands and +thousands of genes which are expressed + + align:start position:0% +thousands of genes which are expressed + + + align:start position:0% +thousands of genes which are expressed +or not expressed and which are also + + align:start position:0% +or not expressed and which are also + + + align:start position:0% +or not expressed and which are also +expressed at different levels and we + + align:start position:0% +expressed at different levels and we + + + align:start position:0% +expressed at different levels and we +have to take that into account so really + + align:start position:0% +have to take that into account so really + + + align:start position:0% +have to take that into account so really +finding the combinatorial code is + + align:start position:0% +finding the combinatorial code is + + + align:start position:0% +finding the combinatorial code is +incredibly difficult and we don't know + + align:start position:0% +incredibly difficult and we don't know + + + align:start position:0% +incredibly difficult and we don't know +any for any cell type but the notion is + + align:start position:0% +any for any cell type but the notion is + + + align:start position:0% +any for any cell type but the notion is +exactly the same I want to remind you + + align:start position:0% +exactly the same I want to remind you + + + align:start position:0% +exactly the same I want to remind you +here with this diagram that the control + + align:start position:0% +here with this diagram that the control + + + align:start position:0% +here with this diagram that the control +of gene expression to give you the final + + align:start position:0% +of gene expression to give you the final + + + align:start position:0% +of gene expression to give you the final +expressed product can be anywhere all + + align:start position:0% +expressed product can be anywhere all + + + align:start position:0% +expressed product can be anywhere all +the way from chromatin structure through + + align:start position:0% +the way from chromatin structure through + + + align:start position:0% +the way from chromatin structure through +transcription all the way through + + align:start position:0% +transcription all the way through + + + align:start position:0% +transcription all the way through +protein processing modification and + + align:start position:0% + + + + align:start position:0% + +localization good + + align:start position:0% +localization good + + + align:start position:0% +localization good +all right so now we have a framework by + + align:start position:0% +all right so now we have a framework by + + + align:start position:0% +all right so now we have a framework by +which we can think of what a cell type + + align:start position:0% +which we can think of what a cell type + + + align:start position:0% +which we can think of what a cell type +is and the question of course that + + align:start position:0% +is and the question of course that + + + align:start position:0% +is and the question of course that +you're asking is so how does that + + align:start position:0% +you're asking is so how does that + + + align:start position:0% +you're asking is so how does that +combinatorial code get expressed in each + + align:start position:0% +combinatorial code get expressed in each + + + align:start position:0% +combinatorial code get expressed in each +of the cell types let's pose that + + align:start position:0% + + + + align:start position:0% + +question how does a cell + + align:start position:0% + + + + align:start position:0% + +type express its code + + align:start position:0% + + + + align:start position:0% + +and there's a couple of + + align:start position:0% +and there's a couple of + + + align:start position:0% +and there's a couple of +answers the global answer that I'm going + + align:start position:0% +answers the global answer that I'm going + + + align:start position:0% +answers the global answer that I'm going +to give you to this question is + + align:start position:0% + + + + align:start position:0% + +stepwise and let's have + + align:start position:0% +stepwise and let's have + + + align:start position:0% +stepwise and let's have +stepwise answer + + align:start position:0% + + + + align:start position:0% + +one the + + align:start position:0% +one the + + + align:start position:0% +one the +idea and we can do this I'm going to do + + align:start position:0% +idea and we can do this I'm going to do + + + align:start position:0% +idea and we can do this I'm going to do +this two ways I'm actually going to do + + align:start position:0% +this two ways I'm actually going to do + + + align:start position:0% +this two ways I'm actually going to do +this no I'm not going to do this two + + align:start position:0% +this no I'm not going to do this two + + + align:start position:0% +this no I'm not going to do this two +ways before we get + + align:start position:0% +ways before we get + + + align:start position:0% +ways before we get +there this is a great slide which will + + align:start position:0% +there this is a great slide which will + + + align:start position:0% +there this is a great slide which will +show you two things one it will show you + + align:start position:0% +show you two things one it will show you + + + align:start position:0% +show you two things one it will show you +the expression patterns of two different + + align:start position:0% +the expression patterns of two different + + + align:start position:0% +the expression patterns of two different +genes in the whole organism so here is a + + align:start position:0% +genes in the whole organism so here is a + + + align:start position:0% +genes in the whole organism so here is a +gene called myod I've shown this to you + + align:start position:0% +gene called myod I've shown this to you + + + align:start position:0% +gene called myod I've shown this to you +before that is cell type specific it's + + align:start position:0% +before that is cell type specific it's + + + align:start position:0% +before that is cell type specific it's +just expressed in these kind of Chevron + + align:start position:0% +just expressed in these kind of Chevron + + + align:start position:0% +just expressed in these kind of Chevron +shaped things which are the developing + + align:start position:0% +shaped things which are the developing + + + align:start position:0% +shaped things which are the developing +skeletal muscles the voluntary muscle + + align:start position:0% +skeletal muscles the voluntary muscle + + + align:start position:0% +skeletal muscles the voluntary muscle +and here are a couple of genes that are + + align:start position:0% +and here are a couple of genes that are + + + align:start position:0% +and here are a couple of genes that are +expressed in large regions of the + + align:start position:0% +expressed in large regions of the + + + align:start position:0% +expressed in large regions of the +developing animal and you can see + + align:start position:0% +developing animal and you can see + + + align:start position:0% +developing animal and you can see +they're expressed because of these + + align:start position:0% +they're expressed because of these + + + align:start position:0% +they're expressed because of these +colors that are there and the colors are + + align:start position:0% +colors that are there and the colors are + + + align:start position:0% +colors that are there and the colors are +indicative of where the RNA for that + + align:start position:0% +indicative of where the RNA for that + + + align:start position:0% +indicative of where the RNA for that +Gene is the technique that allows you to + + align:start position:0% +Gene is the technique that allows you to + + + align:start position:0% +Gene is the technique that allows you to +look in a whole animal and ask where the + + align:start position:0% +look in a whole animal and ask where the + + + align:start position:0% +look in a whole animal and ask where the +rnas for particular genes are found is + + align:start position:0% +rnas for particular genes are found is + + + align:start position:0% +rnas for particular genes are found is +called incu + + align:start position:0% +called incu + + + align:start position:0% +called incu +hybridization up here at the top of the + + align:start position:0% +hybridization up here at the top of the + + + align:start position:0% +hybridization up here at the top of the +screen + + align:start position:0% +screen + + + align:start position:0% +screen +and the idea is that you take animals + + align:start position:0% +and the idea is that you take animals + + + align:start position:0% +and the idea is that you take animals +here I've said embryos developing + + align:start position:0% +here I've said embryos developing + + + align:start position:0% +here I've said embryos developing +animals and you fix them which means you + + align:start position:0% +animals and you fix them which means you + + + align:start position:0% +animals and you fix them which means you +kill them and you permeabilize them you + + align:start position:0% +kill them and you permeabilize them you + + + align:start position:0% +kill them and you permeabilize them you +make holes in them and then you use the + + align:start position:0% +make holes in them and then you use the + + + align:start position:0% +make holes in them and then you use the +principles of base pairing where you + + align:start position:0% +principles of base pairing where you + + + align:start position:0% +principles of base pairing where you +look and see where the RNA is using a + + align:start position:0% +look and see where the RNA is using a + + + align:start position:0% +look and see where the RNA is using a +probe which is an anti-sense RNA for a + + align:start position:0% +probe which is an anti-sense RNA for a + + + align:start position:0% +probe which is an anti-sense RNA for a +particular Gene of interest and you + + align:start position:0% +particular Gene of interest and you + + + align:start position:0% +particular Gene of interest and you +label this anti-sense RNA you mix it + + align:start position:0% +label this anti-sense RNA you mix it + + + align:start position:0% +label this anti-sense RNA you mix it +with the embryo that's got holes in or + + align:start position:0% +with the embryo that's got holes in or + + + align:start position:0% +with the embryo that's got holes in or +the animal that's got holes where the + + align:start position:0% +the animal that's got holes where the + + + align:start position:0% +the animal that's got holes where the +RNA for Gene X is it will base pair to + + align:start position:0% +RNA for Gene X is it will base pair to + + + align:start position:0% +RNA for Gene X is it will base pair to +your anti-sense probe you then wash out + + align:start position:0% +your anti-sense probe you then wash out + + + align:start position:0% +your anti-sense probe you then wash out +the extra and you look and see where the + + align:start position:0% +the extra and you look and see where the + + + align:start position:0% +the extra and you look and see where the +color that comes from the label is and + + align:start position:0% +color that comes from the label is and + + + align:start position:0% +color that comes from the label is and +that color tells you where the RNA for a + + align:start position:0% +that color tells you where the RNA for a + + + align:start position:0% +that color tells you where the RNA for a +particular Gene is so these colors in + + align:start position:0% +particular Gene is so these colors in + + + align:start position:0% +particular Gene is so these colors in +this developing animal tell you where + + align:start position:0% +this developing animal tell you where + + + align:start position:0% +this developing animal tell you where +particular rnas are it's a very powerful + + align:start position:0% +particular rnas are it's a very powerful + + + align:start position:0% +particular rnas are it's a very powerful +technique and it allows us to figure out + + align:start position:0% +technique and it allows us to figure out + + + align:start position:0% +technique and it allows us to figure out +which genes are + + align:start position:0% +which genes are + + + align:start position:0% +which genes are +type specific and which genes are more + + align:start position:0% +type specific and which genes are more + + + align:start position:0% +type specific and which genes are more +generally + + align:start position:0% +generally + + + align:start position:0% +generally +expressed + + align:start position:0% + + + + align:start position:0% + +okay let's look at your first handout + + align:start position:0% +okay let's look at your first handout + + + align:start position:0% +okay let's look at your first handout +and I'm going to write it on the board + + align:start position:0% +and I'm going to write it on the board + + + align:start position:0% +and I'm going to write it on the board +as well because this is really important + + align:start position:0% +as well because this is really important + + + align:start position:0% +as well because this is really important +and you're going to need to know this + + align:start position:0% +and you're going to need to know this + + + align:start position:0% +and you're going to need to know this +for this lecture and when we get to stem + + align:start position:0% +for this lecture and when we get to stem + + + align:start position:0% +for this lecture and when we get to stem +cells as + + align:start position:0% +cells as + + + align:start position:0% +cells as +well so you can look on the screen you + + align:start position:0% +well so you can look on the screen you + + + align:start position:0% +well so you can look on the screen you +can look on your handout and I would + + align:start position:0% +can look on your handout and I would + + + align:start position:0% +can look on your handout and I would +suggest you write it as well the notion + + align:start position:0% +suggest you write it as well the notion + + + align:start position:0% +suggest you write it as well the notion +when we're thinking about cell type is + + align:start position:0% +when we're thinking about cell type is + + + align:start position:0% +when we're thinking about cell type is +that we start off with cells that don't + + align:start position:0% +that we start off with cells that don't + + + align:start position:0% +that we start off with cells that don't +know who they are and they're called + + align:start position:0% +know who they are and they're called + + + align:start position:0% +know who they are and they're called +uncommitted + + align:start position:0% + + + + align:start position:0% + +cells they are + + align:start position:0% + + + + align:start position:0% + +undecided and as they go through + + align:start position:0% +undecided and as they go through + + + align:start position:0% +undecided and as they go through +life they get some inputs we'll be vague + + align:start position:0% +life they get some inputs we'll be vague + + + align:start position:0% +life they get some inputs we'll be vague +about those they're up there I'm not + + align:start position:0% +about those they're up there I'm not + + + align:start position:0% +about those they're up there I'm not +going to write them here and at that + + align:start position:0% +going to write them here and at that + + + align:start position:0% +going to write them here and at that +point they become emitted + + align:start position:0% +point they become emitted + + + align:start position:0% +point they become emitted +cells they're sometimes called + + align:start position:0% +cells they're sometimes called + + + align:start position:0% +cells they're sometimes called +determined + + align:start position:0% + + + + align:start position:0% + +cells and at this point the cells have + + align:start position:0% +cells and at this point the cells have + + + align:start position:0% +cells and at this point the cells have +decided what they're going to + + align:start position:0% +decided what they're going to + + + align:start position:0% +decided what they're going to +become and later on those committed or + + align:start position:0% +become and later on those committed or + + + align:start position:0% +become and later on those committed or +determined cells will go on and they + + align:start position:0% +determined cells will go on and they + + + align:start position:0% +determined cells will go on and they +will become differentiated + + align:start position:0% + + + + align:start position:0% + +cells where they have their final fate + + align:start position:0% +cells where they have their final fate + + + align:start position:0% +cells where they have their final fate +or their final + + align:start position:0% + + + + align:start position:0% + +function there's a Time metric on + + align:start position:0% +function there's a Time metric on + + + align:start position:0% +function there's a Time metric on +this + + align:start position:0% +this + + + align:start position:0% +this +progression and the notion really is + + align:start position:0% +progression and the notion really is + + + align:start position:0% +progression and the notion really is +that as cells go through this decision + + align:start position:0% +that as cells go through this decision + + + align:start position:0% +that as cells go through this decision +making process they change which genes + + align:start position:0% +making process they change which genes + + + align:start position:0% +making process they change which genes +they are expressing such that at the + + align:start position:0% +they are expressing such that at the + + + align:start position:0% +they are expressing such that at the +culmination but if you think about this + + align:start position:0% +culmination but if you think about this + + + align:start position:0% +culmination but if you think about this +or come and talk to me you'll find it's + + align:start position:0% +or come and talk to me you'll find it's + + + align:start position:0% +or come and talk to me you'll find it's +more complicated at the culmination they + + align:start position:0% +more complicated at the culmination they + + + align:start position:0% +more complicated at the culmination they +will be expressing their combinatorial + + align:start position:0% +will be expressing their combinatorial + + + align:start position:0% +will be expressing their combinatorial +code uncommitted + + align:start position:0% + + + + align:start position:0% + +cells as they transition to committed + + align:start position:0% +cells as they transition to committed + + + align:start position:0% +cells as they transition to committed +cells activate a set of genes that I'm + + align:start position:0% +cells activate a set of genes that I'm + + + align:start position:0% +cells activate a set of genes that I'm +going to call regulatory genes they're + + align:start position:0% +going to call regulatory genes they're + + + align:start position:0% +going to call regulatory genes they're +the transcription factors the + + align:start position:0% +the transcription factors the + + + align:start position:0% +the transcription factors the +translation factors the protein + + align:start position:0% +translation factors the protein + + + align:start position:0% +translation factors the protein +processing factors + + align:start position:0% + + + + align:start position:0% + +and these regulatory genes will then go + + align:start position:0% +and these regulatory genes will then go + + + align:start position:0% +and these regulatory genes will then go +and activate a set of + + align:start position:0% +and activate a set of + + + align:start position:0% +and activate a set of +genes that I'll call affector + + align:start position:0% + + + + align:start position:0% + +genes and the affector genes are the + + align:start position:0% +genes and the affector genes are the + + + align:start position:0% +genes and the affector genes are the +ones that are actually carrying out the + + align:start position:0% +ones that are actually carrying out the + + + align:start position:0% +ones that are actually carrying out the +function of the cell they are the globin + + align:start position:0% +function of the cell they are the globin + + + align:start position:0% +function of the cell they are the globin +that's carrying the oxygen around the + + align:start position:0% +that's carrying the oxygen around the + + + align:start position:0% +that's carrying the oxygen around the +body they are the neurofilaments that + + align:start position:0% +body they are the neurofilaments that + + + align:start position:0% +body they are the neurofilaments that +are making the neurons long and strong + + align:start position:0% +are making the neurons long and strong + + + align:start position:0% +are making the neurons long and strong +and able to transmit a signal they are + + align:start position:0% +and able to transmit a signal they are + + + align:start position:0% +and able to transmit a signal they are +the Keratin which make hair cells able + + align:start position:0% +the Keratin which make hair cells able + + + align:start position:0% +the Keratin which make hair cells able +to secrete the hair that actually you + + align:start position:0% +to secrete the hair that actually you + + + align:start position:0% +to secrete the hair that actually you +see so the affector genes are the + + align:start position:0% +see so the affector genes are the + + + align:start position:0% +see so the affector genes are the +functioning the + + align:start position:0% +functioning the + + + align:start position:0% +functioning the +functional + + align:start position:0% + + + + align:start position:0% + +mediators and it's this mix of + + align:start position:0% +mediators and it's this mix of + + + align:start position:0% +mediators and it's this mix of +regulatory genes which I've written as R + + align:start position:0% +regulatory genes which I've written as R + + + align:start position:0% +regulatory genes which I've written as R +and effed genes which I've written + + align:start position:0% +and effed genes which I've written + + + align:start position:0% +and effed genes which I've written +written as e which form the + + align:start position:0% +written as e which form the + + + align:start position:0% +written as e which form the +combinatorial + + align:start position:0% +combinatorial + + + align:start position:0% +combinatorial +code for a + + align:start position:0% + + + + align:start position:0% + +cell okay so that's one answer and you + + align:start position:0% +cell okay so that's one answer and you + + + align:start position:0% +cell okay so that's one answer and you +have more up there which we'll come to + + align:start position:0% +have more up there which we'll come to + + + align:start position:0% +have more up there which we'll come to +in a moment but let me give you another + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +answer it's also the same answer step + + align:start position:0% + + + + align:start position:0% + +wise but this answer has to do with the + + align:start position:0% +wise but this answer has to do with the + + + align:start position:0% +wise but this answer has to do with the +history of an organism I've avoided + + align:start position:0% +history of an organism I've avoided + + + align:start position:0% +history of an organism I've avoided +talking about embryos until now because + + align:start position:0% +talking about embryos until now because + + + align:start position:0% +talking about embryos until now because +I wanted you to think about the outcome + + align:start position:0% +I wanted you to think about the outcome + + + align:start position:0% +I wanted you to think about the outcome +the cell types but actually all of this + + align:start position:0% +the cell types but actually all of this + + + align:start position:0% +the cell types but actually all of this +starts cell type formation starts right + + align:start position:0% +starts cell type formation starts right + + + align:start position:0% +starts cell type formation starts right +at the beginning of an organism's + + align:start position:0% +at the beginning of an organism's + + + align:start position:0% +at the beginning of an organism's +life when two haid cells the egg and the + + align:start position:0% +life when two haid cells the egg and the + + + align:start position:0% +life when two haid cells the egg and the +sperm + + align:start position:0% +sperm + + + align:start position:0% +sperm +magically get together and join to form + + align:start position:0% +magically get together and join to form + + + align:start position:0% +magically get together and join to form +a diploid + + align:start position:0% + + + + align:start position:0% + +cell the + + align:start position:0% + + + + align:start position:0% + +zygote this zygote which is also a + + align:start position:0% +zygote this zygote which is also a + + + align:start position:0% +zygote this zygote which is also a +single + + align:start position:0% + + + + align:start position:0% + +cell is itself a magical cell because it + + align:start position:0% +cell is itself a magical cell because it + + + align:start position:0% +cell is itself a magical cell because it +contains all the information necessary + + align:start position:0% +contains all the information necessary + + + align:start position:0% +contains all the information necessary +to form whatever organism is going to be + + align:start position:0% +to form whatever organism is going to be + + + align:start position:0% +to form whatever organism is going to be +the outcome + + align:start position:0% +the outcome + + + align:start position:0% +the outcome +the zygote goes on to form an + + align:start position:0% + + + + align:start position:0% + +embryo also + + align:start position:0% +embryo also + + + align:start position:0% +embryo also +diploid that contains many + + align:start position:0% + + + + align:start position:0% + +cells and the embryo goes on to form the + + align:start position:0% +cells and the embryo goes on to form the + + + align:start position:0% +cells and the embryo goes on to form the +diploid + + align:start position:0% +diploid + + + align:start position:0% +diploid +adult + + align:start position:0% +adult + + + align:start position:0% +adult +also with many cells and in humans there + + align:start position:0% +also with many cells and in humans there + + + align:start position:0% +also with many cells and in humans there +are about 10 to the 14th + + align:start position:0% +are about 10 to the 14th + + + align:start position:0% +are about 10 to the 14th +cells in a human + + align:start position:0% + + + + align:start position:0% + +adult and during this + + align:start position:0% +adult and during this + + + align:start position:0% +adult and during this +process of two single cells two dying + + align:start position:0% +process of two single cells two dying + + + align:start position:0% +process of two single cells two dying +cells the egg and the sperm are cells + + align:start position:0% +cells the egg and the sperm are cells + + + align:start position:0% +cells the egg and the sperm are cells +with a very finite lifetime when those + + align:start position:0% +with a very finite lifetime when those + + + align:start position:0% +with a very finite lifetime when those +cells fuse with one another and we're + + align:start position:0% +cells fuse with one another and we're + + + align:start position:0% +cells fuse with one another and we're +not going to talk about this any more + + align:start position:0% +not going to talk about this any more + + + align:start position:0% +not going to talk about this any more +than than than this discussion because + + align:start position:0% +than than than this discussion because + + + align:start position:0% +than than than this discussion because +of time + + align:start position:0% +of time + + + align:start position:0% +of time +constraints when they refuse to form the + + align:start position:0% +constraints when they refuse to form the + + + align:start position:0% +constraints when they refuse to form the +zygote there is an extraordinary process + + align:start position:0% +zygote there is an extraordinary process + + + align:start position:0% +zygote there is an extraordinary process +where the zygote is now resurrected in + + align:start position:0% +where the zygote is now resurrected in + + + align:start position:0% +where the zygote is now resurrected in +its life and it has the capacity to give + + align:start position:0% +its life and it has the capacity to give + + + align:start position:0% +its life and it has the capacity to give +rise to the whole + + align:start position:0% +rise to the whole + + + align:start position:0% +rise to the whole +organism what happens during this + + align:start position:0% +organism what happens during this + + + align:start position:0% +organism what happens during this +process well firstly I've pointed out + + align:start position:0% +process well firstly I've pointed out + + + align:start position:0% +process well firstly I've pointed out +cells + + align:start position:0% +cells + + + align:start position:0% +cells +divide there's a lot of cell division + + align:start position:0% +divide there's a lot of cell division + + + align:start position:0% +divide there's a lot of cell division +and that's really key to getting + + align:start position:0% +and that's really key to getting + + + align:start position:0% +and that's really key to getting +different cell types you have to have + + align:start position:0% +different cell types you have to have + + + align:start position:0% +different cell types you have to have +something to work with and as they + + align:start position:0% +something to work with and as they + + + align:start position:0% +something to work with and as they +divide they become different + + align:start position:0% + + + + align:start position:0% + +according to the list on the screen and + + align:start position:0% +according to the list on the screen and + + + align:start position:0% +according to the list on the screen and +on the board above the egg the + + align:start position:0% +on the board above the egg the + + + align:start position:0% +on the board above the egg the +sperm in fact are differentiated + + align:start position:0% +sperm in fact are differentiated + + + align:start position:0% +sperm in fact are differentiated +cells but let's start with the zygote + + align:start position:0% +cells but let's start with the zygote + + + align:start position:0% +cells but let's start with the zygote +which is + + align:start position:0% +which is + + + align:start position:0% +which is +undetermined or + + align:start position:0% + + + + align:start position:0% + +uncommitted and undifferentiated + + align:start position:0% + + + + align:start position:0% + +and I'm using determined and committed + + align:start position:0% +and I'm using determined and committed + + + align:start position:0% +and I'm using determined and committed +deliberately interchangeably so you get + + align:start position:0% +deliberately interchangeably so you get + + + align:start position:0% +deliberately interchangeably so you get +the idea that the terms are + + align:start position:0% +the idea that the terms are + + + align:start position:0% +the idea that the terms are +interchangeable so the zygote is + + align:start position:0% +interchangeable so the zygote is + + + align:start position:0% +interchangeable so the zygote is +undetermined and + + align:start position:0% +undetermined and + + + align:start position:0% +undetermined and +undifferentiated and as it goes through + + align:start position:0% +undifferentiated and as it goes through + + + align:start position:0% +undifferentiated and as it goes through +its embryonic stage determination + + align:start position:0% + + + + align:start position:0% + +starts and + + align:start position:0% +starts and + + + align:start position:0% +starts and +continues into the adult and later + + align:start position:0% +continues into the adult and later + + + align:start position:0% +continues into the adult and later +during late stages of embryogenesis and + + align:start position:0% +during late stages of embryogenesis and + + + align:start position:0% +during late stages of embryogenesis and +into the adult cells differentiate and + + align:start position:0% +into the adult cells differentiate and + + + align:start position:0% +into the adult cells differentiate and +become their final thing so + + align:start position:0% +become their final thing so + + + align:start position:0% +become their final thing so +determination starts in the embryo and + + align:start position:0% +determination starts in the embryo and + + + align:start position:0% +determination starts in the embryo and +sometime later the process of + + align:start position:0% + + + + align:start position:0% + +differentiation starts and + + align:start position:0% +differentiation starts and + + + align:start position:0% +differentiation starts and +continues and so that's a second way of + + align:start position:0% +continues and so that's a second way of + + + align:start position:0% +continues and so that's a second way of +actually writing out the stepwise + + align:start position:0% +actually writing out the stepwise + + + align:start position:0% +actually writing out the stepwise +phenomenon of how cells become different + + align:start position:0% +phenomenon of how cells become different + + + align:start position:0% +phenomenon of how cells become different +from one another and how different cell + + align:start position:0% +from one another and how different cell + + + align:start position:0% +from one another and how different cell +types are formed + + align:start position:0% +types are formed + + + align:start position:0% +types are formed +let's take a look at some slides here + + align:start position:0% +let's take a look at some slides here + + + align:start position:0% +let's take a look at some slides here +and let's take a look at a couple of + + align:start position:0% +and let's take a look at a couple of + + + align:start position:0% +and let's take a look at a couple of +movies this is a movie of the first few + + align:start position:0% +movies this is a movie of the first few + + + align:start position:0% +movies this is a movie of the first few +weeks of human development and what + + align:start position:0% +weeks of human development and what + + + align:start position:0% +weeks of human development and what +you'll be able to see from this is the + + align:start position:0% +you'll be able to see from this is the + + + align:start position:0% +you'll be able to see from this is the +enormous increase in size of a human + + align:start position:0% +enormous increase in size of a human + + + align:start position:0% +enormous increase in size of a human +embryo that's coupled with cell division + + align:start position:0% +embryo that's coupled with cell division + + + align:start position:0% +embryo that's coupled with cell division +and also with cell + + align:start position:0% + + + + align:start position:0% + +determination and it's going to play + + align:start position:0% +determination and it's going to play + + + align:start position:0% +determination and it's going to play +again and what you can see up until + + align:start position:0% +again and what you can see up until + + + align:start position:0% +again and what you can see up until +about day 56 we all had very nice tails + + align:start position:0% +about day 56 we all had very nice tails + + + align:start position:0% +about day 56 we all had very nice tails +and then they disappeared unlike other + + align:start position:0% +and then they disappeared unlike other + + + align:start position:0% +and then they disappeared unlike other +animals but all of these are taken at + + align:start position:0% +animals but all of these are taken at + + + align:start position:0% +animals but all of these are taken at +the same scale and so you can get a + + align:start position:0% +the same scale and so you can get a + + + align:start position:0% +the same scale and so you can get a +sense of the huge amount of cell + + align:start position:0% +sense of the huge amount of cell + + + align:start position:0% +sense of the huge amount of cell +division that's going on during these + + align:start position:0% +division that's going on during these + + + align:start position:0% +division that's going on during these +first few weeks of + + align:start position:0% +first few weeks of + + + align:start position:0% +first few weeks of +Life here's a second one this is a zebra + + align:start position:0% +Life here's a second one this is a zebra + + + align:start position:0% +Life here's a second one this is a zebra +fish embryo and I want you to watch this + + align:start position:0% +fish embryo and I want you to watch this + + + align:start position:0% +fish embryo and I want you to watch this +embryo as it develops very rapidly much + + align:start position:0% +embryo as it develops very rapidly much + + + align:start position:0% +embryo as it develops very rapidly much +more rapidly than a human during the + + align:start position:0% +more rapidly than a human during the + + + align:start position:0% +more rapidly than a human during the +first 19 hours of development + + align:start position:0% +first 19 hours of development + + + align:start position:0% +first 19 hours of development +the fish embryo is kind of like a + + align:start position:0% +the fish embryo is kind of like a + + + align:start position:0% +the fish embryo is kind of like a +chicken embryo there's a big cell called + + align:start position:0% +chicken embryo there's a big cell called + + + align:start position:0% +chicken embryo there's a big cell called +a Yol cell and on top of this Yol cell + + align:start position:0% +a Yol cell and on top of this Yol cell + + + align:start position:0% +a Yol cell and on top of this Yol cell +sits a little other cell which is the + + align:start position:0% +sits a little other cell which is the + + + align:start position:0% +sits a little other cell which is the +embryo itself and it's this little top + + align:start position:0% +embryo itself and it's this little top + + + align:start position:0% +embryo itself and it's this little top +cell here it's already divided to give + + align:start position:0% +cell here it's already divided to give + + + align:start position:0% +cell here it's already divided to give +rise to two cells from which the embryo + + align:start position:0% +rise to two cells from which the embryo + + + align:start position:0% +rise to two cells from which the embryo +is going to arise and so as you watch + + align:start position:0% +is going to arise and so as you watch + + + align:start position:0% +is going to arise and so as you watch +the movie you'll see these two cells + + align:start position:0% +the movie you'll see these two cells + + + align:start position:0% +the movie you'll see these two cells +dividing into four into eight and so on + + align:start position:0% +dividing into four into eight and so on + + + align:start position:0% +dividing into four into eight and so on +and then you'll be able to see the + + align:start position:0% +and then you'll be able to see the + + + align:start position:0% +and then you'll be able to see the +beginnings of the fish emerge and I'll + + align:start position:0% +beginnings of the fish emerge and I'll + + + align:start position:0% +beginnings of the fish emerge and I'll +play it a couple of times and point out + + align:start position:0% +play it a couple of times and point out + + + align:start position:0% +play it a couple of times and point out +some things to you here's the cell + + align:start position:0% +some things to you here's the cell + + + align:start position:0% +some things to you here's the cell +division taking place it's not as rapid + + align:start position:0% +division taking place it's not as rapid + + + align:start position:0% +division taking place it's not as rapid +as this but it's of course a very rapid + + align:start position:0% +as this but it's of course a very rapid + + + align:start position:0% +as this but it's of course a very rapid +process and now you have a little cap of + + align:start position:0% +process and now you have a little cap of + + + align:start position:0% +process and now you have a little cap of +cells on the Yol and Watch What Happens + + align:start position:0% +cells on the Yol and Watch What Happens + + + align:start position:0% +cells on the Yol and Watch What Happens +that cap of cells spreads out to cover + + align:start position:0% +that cap of cells spreads out to cover + + + align:start position:0% +that cap of cells spreads out to cover +up the Yoke and a lot of cells move to + + align:start position:0% +up the Yoke and a lot of cells move to + + + align:start position:0% +up the Yoke and a lot of cells move to +that side of the embryo the right hand + + align:start position:0% +that side of the embryo the right hand + + + align:start position:0% +that side of the embryo the right hand +side of the screen here's the eye + + align:start position:0% +side of the screen here's the eye + + + align:start position:0% +side of the screen here's the eye +emerging and the brain and here are the + + align:start position:0% +emerging and the brain and here are the + + + align:start position:0% +emerging and the brain and here are the +muscles of the fish and let's watch it + + align:start position:0% +muscles of the fish and let's watch it + + + align:start position:0% +muscles of the fish and let's watch it +again + + align:start position:0% +again + + + align:start position:0% +again +Isn't that + + align:start position:0% + + + + align:start position:0% + +cool okay so let me stop it here at this + + align:start position:0% +cool okay so let me stop it here at this + + + align:start position:0% +cool okay so let me stop it here at this +stage you've got several hundred cells + + align:start position:0% +stage you've got several hundred cells + + + align:start position:0% +stage you've got several hundred cells +that are sitting on top of this Yol cell + + align:start position:0% +that are sitting on top of this Yol cell + + + align:start position:0% +that are sitting on top of this Yol cell +this pointer seems to have died but + + align:start position:0% +this pointer seems to have died but + + + align:start position:0% +this pointer seems to have died but +they're sitting on top of the Yol cell + + align:start position:0% +they're sitting on top of the Yol cell + + + align:start position:0% +they're sitting on top of the Yol cell +and you'll be able to see when I start + + align:start position:0% +and you'll be able to see when I start + + + align:start position:0% +and you'll be able to see when I start +the movie again how those cells spread + + align:start position:0% +the movie again how those cells spread + + + align:start position:0% +the movie again how those cells spread +out to cover and they are actively doing + + align:start position:0% +out to cover and they are actively doing + + + align:start position:0% +out to cover and they are actively doing +it they know to do it they actively + + align:start position:0% +it they know to do it they actively + + + align:start position:0% +it they know to do it they actively +spread out to cover the surface of the + + align:start position:0% +spread out to cover the surface of the + + + align:start position:0% +spread out to cover the surface of the +embryo and then actively a group of them + + align:start position:0% +embryo and then actively a group of them + + + align:start position:0% +embryo and then actively a group of them +moves to one side of the embryo to form + + align:start position:0% +moves to one side of the embryo to form + + + align:start position:0% +moves to one side of the embryo to form +most of the embryo including all the + + align:start position:0% +most of the embryo including all the + + + align:start position:0% +most of the embryo including all the +nervous system the muscles the + + align:start position:0% +nervous system the muscles the + + + align:start position:0% +nervous system the muscles the +intestines and so on so let's start it + + align:start position:0% + + + + align:start position:0% + +again okay there you can see these cells + + align:start position:0% +again okay there you can see these cells + + + align:start position:0% +again okay there you can see these cells +spreading out they've spread it out to + + align:start position:0% +spreading out they've spread it out to + + + align:start position:0% +spreading out they've spread it out to +this they've spread out to this point + + align:start position:0% +this they've spread out to this point + + + align:start position:0% +this they've spread out to this point +let's let them spread out some more here + + align:start position:0% +let's let them spread out some more here + + + align:start position:0% +let's let them spread out some more here +they are they've completely closed up + + align:start position:0% +they are they've completely closed up + + + align:start position:0% +they are they've completely closed up +the Yol and if we stop now you'll see on + + align:start position:0% +the Yol and if we stop now you'll see on + + + align:start position:0% +the Yol and if we stop now you'll see on +the right right hand side of the screen + + align:start position:0% +the right right hand side of the screen + + + align:start position:0% +the right right hand side of the screen +there's a much thicker group of cells + + align:start position:0% +there's a much thicker group of cells + + + align:start position:0% +there's a much thicker group of cells +there are thousands and thousands of + + align:start position:0% +there are thousands and thousands of + + + align:start position:0% +there are thousands and thousands of +cells now that are there now at this + + align:start position:0% +cells now that are there now at this + + + align:start position:0% +cells now that are there now at this +point if you look at gene expression in + + align:start position:0% +point if you look at gene expression in + + + align:start position:0% +point if you look at gene expression in +the embryo you can pick out many + + align:start position:0% +the embryo you can pick out many + + + align:start position:0% +the embryo you can pick out many +different regions of the future brain + + align:start position:0% +different regions of the future brain + + + align:start position:0% +different regions of the future brain +you can pick out the future intestines + + align:start position:0% +you can pick out the future intestines + + + align:start position:0% +you can pick out the future intestines +and the future muscles but there is no + + align:start position:0% +and the future muscles but there is no + + + align:start position:0% +and the future muscles but there is no +differentiation at this point the cells + + align:start position:0% +differentiation at this point the cells + + + align:start position:0% +differentiation at this point the cells +do not know the cells have not finished + + align:start position:0% +do not know the cells have not finished + + + align:start position:0% +do not know the cells have not finished +becoming what they're becoming and here + + align:start position:0% +becoming what they're becoming and here + + + align:start position:0% +becoming what they're becoming and here +as we go on a bit + + align:start position:0% +as we go on a bit + + + align:start position:0% +as we go on a bit +more okay here is the + + align:start position:0% +more okay here is the + + + align:start position:0% +more okay here is the +eye up front and these bumps of the + + align:start position:0% +eye up front and these bumps of the + + + align:start position:0% +eye up front and these bumps of the +brain and then these little Chevron + + align:start position:0% +brain and then these little Chevron + + + align:start position:0% +brain and then these little Chevron +shaped things there are the future + + align:start position:0% +shaped things there are the future + + + align:start position:0% +shaped things there are the future +muscles your fish filet and there is the + + align:start position:0% +muscles your fish filet and there is the + + + align:start position:0% +muscles your fish filet and there is the +fish moving on okay it's really a + + align:start position:0% +fish moving on okay it's really a + + + align:start position:0% +fish moving on okay it's really a +fantastic + + align:start position:0% +fantastic + + + align:start position:0% +fantastic +process + + align:start position:0% +process + + + align:start position:0% +process +okay very good let's go back to the + + align:start position:0% +okay very good let's go back to the + + + align:start position:0% +okay very good let's go back to the +board and talk about this more + + align:start position:0% +board and talk about this more + + + align:start position:0% +board and talk about this more +theoretically we've sort of answered a + + align:start position:0% +theoretically we've sort of answered a + + + align:start position:0% +theoretically we've sort of answered a +question here how does a cell type + + align:start position:0% +question here how does a cell type + + + align:start position:0% +question here how does a cell type +express it its code well not all at once + + align:start position:0% +express it its code well not all at once + + + align:start position:0% +express it its code well not all at once +over time and over a series of many + + align:start position:0% +over time and over a series of many + + + align:start position:0% +over time and over a series of many +steps but that's not actually the whole + + align:start position:0% + + + + align:start position:0% + +answer and so let's rephrase the + + align:start position:0% +answer and so let's rephrase the + + + align:start position:0% +answer and so let's rephrase the +question to make it a little more + + align:start position:0% +question to make it a little more + + + align:start position:0% +question to make it a little more +precise and I've rephrased it by asking + + align:start position:0% +precise and I've rephrased it by asking + + + align:start position:0% +precise and I've rephrased it by asking +what tells a specific cell type to + + align:start position:0% +what tells a specific cell type to + + + align:start position:0% +what tells a specific cell type to +express its + + align:start position:0% + + + + align:start position:0% + +code what tells a specific cell type to + + align:start position:0% +code what tells a specific cell type to + + + align:start position:0% +code what tells a specific cell type to +express its + + align:start position:0% + + + + align:start position:0% + +code and the answer is this is not going + + align:start position:0% +code and the answer is this is not going + + + align:start position:0% +code and the answer is this is not going +to be really helpful to you but it will + + align:start position:0% +to be really helpful to you but it will + + + align:start position:0% +to be really helpful to you but it will +in a moment the answer is that there are + + align:start position:0% +in a moment the answer is that there are + + + align:start position:0% +in a moment the answer is that there are +a bunch of inputs okay there are a bunch + + align:start position:0% +a bunch of inputs okay there are a bunch + + + align:start position:0% +a bunch of inputs okay there are a bunch +of + + align:start position:0% +of + + + align:start position:0% +of +instructions that the cell + + align:start position:0% +instructions that the cell + + + align:start position:0% +instructions that the cell +gets okay + + align:start position:0% + + + + align:start position:0% + +and let's write this out in a kind of + + align:start position:0% +and let's write this out in a kind of + + + align:start position:0% +and let's write this out in a kind of +theoretical way we'll get to the + + align:start position:0% +theoretical way we'll get to the + + + align:start position:0% +theoretical way we'll get to the +molecules in a moment here again are our + + align:start position:0% +molecules in a moment here again are our + + + align:start position:0% +molecules in a moment here again are our +uncommitted + + align:start position:0% + + + + align:start position:0% + +cells and they can be exposed to a + + align:start position:0% +cells and they can be exposed to a + + + align:start position:0% +cells and they can be exposed to a +number of different molecules the inputs + + align:start position:0% +number of different molecules the inputs + + + align:start position:0% +number of different molecules the inputs +let me just you know come clean here the + + align:start position:0% +let me just you know come clean here the + + + align:start position:0% +let me just you know come clean here the +inputs are specific molecules and as + + align:start position:0% +inputs are specific molecules and as + + + align:start position:0% +inputs are specific molecules and as +you'll see in a moment they all have got + + align:start position:0% +you'll see in a moment they all have got + + + align:start position:0% +you'll see in a moment they all have got +something to do with cell signaling or + + align:start position:0% +something to do with cell signaling or + + + align:start position:0% +something to do with cell signaling or +regulating gene + + align:start position:0% +regulating gene + + + align:start position:0% +regulating gene +expression these UNC lied cells can be + + align:start position:0% +expression these UNC lied cells can be + + + align:start position:0% +expression these UNC lied cells can be +exposed to many different inputs let's + + align:start position:0% +exposed to many different inputs let's + + + align:start position:0% +exposed to many different inputs let's +take three different + + align:start position:0% +take three different + + + align:start position:0% +take three different +inputs we'll call them input one two and + + align:start position:0% +inputs we'll call them input one two and + + + align:start position:0% +inputs we'll call them input one two and +three and these inputs through many + + align:start position:0% +three and these inputs through many + + + align:start position:0% +three and these inputs through many +steps and changes in gene + + align:start position:0% +steps and changes in gene + + + align:start position:0% +steps and changes in gene +expression and the inputs can be + + align:start position:0% +expression and the inputs can be + + + align:start position:0% +expression and the inputs can be +composite they don't have to be a single + + align:start position:0% +composite they don't have to be a single + + + align:start position:0% +composite they don't have to be a single +thing we'll take those cells into + + align:start position:0% +thing we'll take those cells into + + + align:start position:0% +thing we'll take those cells into +differentiated cell type one cell type + + align:start position:0% +differentiated cell type one cell type + + + align:start position:0% +differentiated cell type one cell type +two or cell type + + align:start position:0% + + + + align:start position:0% + +three and cell type one you know to + + align:start position:0% +three and cell type one you know to + + + align:start position:0% +three and cell type one you know to +belabor this we'll express code one cell + + align:start position:0% +belabor this we'll express code one cell + + + align:start position:0% +belabor this we'll express code one cell +type two code two + + align:start position:0% + + + + align:start position:0% + +Etc as these decisions are made similar + + align:start position:0% +Etc as these decisions are made similar + + + align:start position:0% +Etc as these decisions are made similar +to the kinds ofc decisions we've looked + + align:start position:0% +to the kinds ofc decisions we've looked + + + align:start position:0% +to the kinds ofc decisions we've looked +at in Biochemistry previously there can + + align:start position:0% +at in Biochemistry previously there can + + + align:start position:0% +at in Biochemistry previously there can +be interactions and so it may be that as + + align:start position:0% +be interactions and so it may be that as + + + align:start position:0% +be interactions and so it may be that as +cell type one develops it's actually + + align:start position:0% + + + + align:start position:0% + +inhibits the formation of cell type + + align:start position:0% +inhibits the formation of cell type + + + align:start position:0% +inhibits the formation of cell type +2 and cell type two in turn might be an + + align:start position:0% +2 and cell type two in turn might be an + + + align:start position:0% +2 and cell type two in turn might be an +inhibitor of the formation of cell type + + align:start position:0% +inhibitor of the formation of cell type + + + align:start position:0% +inhibitor of the formation of cell type +three so there are interactions between + + align:start position:0% +three so there are interactions between + + + align:start position:0% +three so there are interactions between +cells so the inputs + + align:start position:0% +cells so the inputs + + + align:start position:0% +cells so the inputs +can be composite they can comp composed + + align:start position:0% +can be composite they can comp composed + + + align:start position:0% +can be composite they can comp composed +of + + align:start position:0% + + + + align:start position:0% + +several + + align:start position:0% +several + + + align:start position:0% +several +molecules factors if you + + align:start position:0% + + + + align:start position:0% + +like and there's cross + + align:start position:0% + + + + align:start position:0% + +talk just like the cross talk between + + align:start position:0% +talk just like the cross talk between + + + align:start position:0% +talk just like the cross talk between +the receptors that we talked about in + + align:start position:0% +the receptors that we talked about in + + + align:start position:0% +the receptors that we talked about in +cell cell signaling and that's not + + align:start position:0% +cell cell signaling and that's not + + + align:start position:0% +cell cell signaling and that's not +surprising ring because in fact the + + align:start position:0% +surprising ring because in fact the + + + align:start position:0% +surprising ring because in fact the +inputs include cell cell signaling + + align:start position:0% +inputs include cell cell signaling + + + align:start position:0% +inputs include cell cell signaling +molecules those lians and receptors that + + align:start position:0% +molecules those lians and receptors that + + + align:start position:0% +molecules those lians and receptors that +we spoke about previously so what are + + align:start position:0% +we spoke about previously so what are + + + align:start position:0% +we spoke about previously so what are +the + + align:start position:0% + + + + align:start position:0% + +inputs and they're + + align:start position:0% +inputs and they're + + + align:start position:0% +inputs and they're +two + + align:start position:0% +two + + + align:start position:0% +two +one are signals that act between + + align:start position:0% +one are signals that act between + + + align:start position:0% +one are signals that act between +cells just like we've been talking about + + align:start position:0% +cells just like we've been talking about + + + align:start position:0% +cells just like we've been talking about +in cell biology cell cell + + align:start position:0% + + + + align:start position:0% + +signaling and wherever you talk about + + align:start position:0% +signaling and wherever you talk about + + + align:start position:0% +signaling and wherever you talk about +cell cell + + align:start position:0% +cell cell + + + align:start position:0% +cell cell +signaling it is implicit that you're + + align:start position:0% +signaling it is implicit that you're + + + align:start position:0% +signaling it is implicit that you're +talking about interactions between + + align:start position:0% +talking about interactions between + + + align:start position:0% +talking about interactions between +cells + + align:start position:0% + + + + align:start position:0% + +lians which in development are sometimes + + align:start position:0% +lians which in development are sometimes + + + align:start position:0% +lians which in development are sometimes +called + + align:start position:0% + + + + align:start position:0% + +induces act on the receptor + + align:start position:0% + + + + align:start position:0% + +and the + + align:start position:0% + + + + align:start position:0% + +outcome is to change + + align:start position:0% + + + + align:start position:0% + +Sate this is a subset of the signaling + + align:start position:0% +Sate this is a subset of the signaling + + + align:start position:0% +Sate this is a subset of the signaling +interactions we talked about previously + + align:start position:0% +interactions we talked about previously + + + align:start position:0% +interactions we talked about previously +where the response here the response + + align:start position:0% +where the response here the response + + + align:start position:0% +where the response here the response +previously was manifold the response + + align:start position:0% +previously was manifold the response + + + align:start position:0% +previously was manifold the response +here would be to change + + align:start position:0% +here would be to change + + + align:start position:0% +here would be to change +sulfate but there's a second kind of + + align:start position:0% +sulfate but there's a second kind of + + + align:start position:0% +sulfate but there's a second kind of +input and those are the molecules that + + align:start position:0% +input and those are the molecules that + + + align:start position:0% +input and those are the molecules that +are + + align:start position:0% + + + + align:start position:0% + +cell + + align:start position:0% + + + + align:start position:0% + +autonomous also referred to as being + + align:start position:0% +autonomous also referred to as being + + + align:start position:0% +autonomous also referred to as being +inherited + + align:start position:0% + + + + align:start position:0% + +factors and referred to in development + + align:start position:0% +factors and referred to in development + + + align:start position:0% +factors and referred to in development +as + + align:start position:0% + + + + align:start position:0% + +determinants and these + + align:start position:0% +determinants and these + + + align:start position:0% +determinants and these +determinants this is what cell + + align:start position:0% +determinants this is what cell + + + align:start position:0% +determinants this is what cell +autonomous means act within cells + + align:start position:0% + + + + align:start position:0% + +and so they are not going to be lians + + align:start position:0% +and so they are not going to be lians + + + align:start position:0% +and so they are not going to be lians +and receptors they will be things for + + align:start position:0% +and receptors they will be things for + + + align:start position:0% +and receptors they will be things for +example like transcription + + align:start position:0% + + + + align:start position:0% + +factors + + align:start position:0% + + + + align:start position:0% + +furthermore both determinants and + + align:start position:0% +furthermore both determinants and + + + align:start position:0% +furthermore both determinants and +inducers can act in a concentration + + align:start position:0% +inducers can act in a concentration + + + align:start position:0% +inducers can act in a concentration +dependent way so that a small amount + + align:start position:0% +dependent way so that a small amount + + + align:start position:0% +dependent way so that a small amount +would give you one + + align:start position:0% +would give you one + + + align:start position:0% +would give you one +sulfate and a larger amount would give + + align:start position:0% +sulfate and a larger amount would give + + + align:start position:0% +sulfate and a larger amount would give +you a different + + align:start position:0% + + + + align:start position:0% + +sulfate so can be concentration + + align:start position:0% + + + + align:start position:0% + +dependent and in the cases where a + + align:start position:0% +dependent and in the cases where a + + + align:start position:0% +dependent and in the cases where a +signal or a determinant is concentration + + align:start position:0% +signal or a determinant is concentration + + + align:start position:0% +signal or a determinant is concentration +dependent it gets a special name it's + + align:start position:0% +dependent it gets a special name it's + + + align:start position:0% +dependent it gets a special name it's +referred to as a + + align:start position:0% +referred to as a + + + align:start position:0% +referred to as a +morphogen for historical not + + align:start position:0% +morphogen for historical not + + + align:start position:0% +morphogen for historical not +particularly logical reasons but if you + + align:start position:0% +particularly logical reasons but if you + + + align:start position:0% +particularly logical reasons but if you +see the term you'll + + align:start position:0% +see the term you'll + + + align:start position:0% +see the term you'll +know and finally before we go to some + + align:start position:0% +know and finally before we go to some + + + align:start position:0% +know and finally before we go to some +slides one can find groups of these + + align:start position:0% +slides one can find groups of these + + + align:start position:0% +slides one can find groups of these +inputs groups of these regulatory + + align:start position:0% +inputs groups of these regulatory + + + align:start position:0% +inputs groups of these regulatory +molecules so all of these + + align:start position:0% + + + + align:start position:0% + +inputs all of these are the regulatory + + align:start position:0% +inputs all of these are the regulatory + + + align:start position:0% +inputs all of these are the regulatory +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +regulatory + + align:start position:0% + + + + align:start position:0% + +factors and they can act spatially in a + + align:start position:0% +factors and they can act spatially in a + + + align:start position:0% +factors and they can act spatially in a +group so you can find regions of the + + align:start position:0% +group so you can find regions of the + + + align:start position:0% +group so you can find regions of the +developing embryo where there are groups + + align:start position:0% +developing embryo where there are groups + + + align:start position:0% +developing embryo where there are groups +of these molecules acting together and + + align:start position:0% +of these molecules acting together and + + + align:start position:0% +of these molecules acting together and +where you find these groups that + + align:start position:0% +where you find these groups that + + + align:start position:0% +where you find these groups that +particular region of the embryo may have + + align:start position:0% +particular region of the embryo may have + + + align:start position:0% +particular region of the embryo may have +a powerful effect in influencing the + + align:start position:0% +a powerful effect in influencing the + + + align:start position:0% +a powerful effect in influencing the +cells which form around it and that + + align:start position:0% +cells which form around it and that + + + align:start position:0% +cells which form around it and that +region that group of of factors in one + + align:start position:0% +region that group of of factors in one + + + align:start position:0% +region that group of of factors in one +region that can influence its + + align:start position:0% +region that can influence its + + + align:start position:0% +region that can influence its +surroundings is called an + + align:start position:0% +surroundings is called an + + + align:start position:0% +surroundings is called an +organizer so groups of + + align:start position:0% + + + + align:start position:0% + +signals which are + + align:start position:0% +signals which are + + + align:start position:0% +signals which are +localized that is in one + + align:start position:0% + + + + align:start position:0% + +place in one group of + + align:start position:0% + + + + align:start position:0% + +cells can influence the surrounding + + align:start position:0% +cells can influence the surrounding + + + align:start position:0% +cells can influence the surrounding +cells + + align:start position:0% + + + + align:start position:0% + +and is termed an + + align:start position:0% + + + + align:start position:0% + +organizer and there are many + + align:start position:0% +organizer and there are many + + + align:start position:0% +organizer and there are many +organizers in the body both in the + + align:start position:0% +organizers in the body both in the + + + align:start position:0% +organizers in the body both in the +embryo and in ourselves as we'll discuss + + align:start position:0% +embryo and in ourselves as we'll discuss + + + align:start position:0% +embryo and in ourselves as we'll discuss +when we talk about stem + + align:start position:0% +when we talk about stem + + + align:start position:0% +when we talk about stem +cells examples of organizers I'll show + + align:start position:0% +cells examples of organizers I'll show + + + align:start position:0% +cells examples of organizers I'll show +you in a moment there's something called + + align:start position:0% +you in a moment there's something called + + + align:start position:0% +you in a moment there's something called +the span organizer which is very famous + + align:start position:0% +the span organizer which is very famous + + + align:start position:0% +the span organizer which is very famous +and some of you may have leared about + + align:start position:0% +and some of you may have leared about + + + align:start position:0% +and some of you may have leared about +that + + align:start position:0% +that + + + align:start position:0% +that +previously and then there are regions + + align:start position:0% +previously and then there are regions + + + align:start position:0% +previously and then there are regions +for + + align:start position:0% +for + + + align:start position:0% +for +example in the forbrain the developing + + align:start position:0% +example in the forbrain the developing + + + align:start position:0% +example in the forbrain the developing +cerebrum where there is an organizer + + align:start position:0% +cerebrum where there is an organizer + + + align:start position:0% +cerebrum where there is an organizer +that actually tells the different parts + + align:start position:0% +that actually tells the different parts + + + align:start position:0% +that actually tells the different parts +of you're developing higher cortical + + align:start position:0% +of you're developing higher cortical + + + align:start position:0% +of you're developing higher cortical +function to form so let's look at some + + align:start position:0% +function to form so let's look at some + + + align:start position:0% +function to form so let's look at some +slides and some of your + + align:start position:0% + + + + align:start position:0% + +handouts and I drew these for you + + align:start position:0% +handouts and I drew these for you + + + align:start position:0% +handouts and I drew these for you +because I thought it was really + + align:start position:0% +because I thought it was really + + + align:start position:0% +because I thought it was really +important that you got them here's + + align:start position:0% +important that you got them here's + + + align:start position:0% +important that you got them here's +localized + + align:start position:0% +localized + + + align:start position:0% +localized +determinance localized Regulators called + + align:start position:0% +determinance localized Regulators called + + + align:start position:0% +determinance localized Regulators called +determinant and you see the idea here + + align:start position:0% +determinant and you see the idea here + + + align:start position:0% +determinant and you see the idea here +this is important this isn't on the + + align:start position:0% +this is important this isn't on the + + + align:start position:0% +this is important this isn't on the +board here's the Mother + + align:start position:0% +board here's the Mother + + + align:start position:0% +board here's the Mother +cell with these boxes where these boxes + + align:start position:0% +cell with these boxes where these boxes + + + align:start position:0% +cell with these boxes where these boxes +represent some kind of regulatory factor + + align:start position:0% +represent some kind of regulatory factor + + + align:start position:0% +represent some kind of regulatory factor +and you can see I've drawn them on one + + align:start position:0% +and you can see I've drawn them on one + + + align:start position:0% +and you can see I've drawn them on one +side of the cell such that when that + + align:start position:0% +side of the cell such that when that + + + align:start position:0% +side of the cell such that when that +cell divides one of the does doesn't get + + align:start position:0% +cell divides one of the does doesn't get + + + align:start position:0% +cell divides one of the does doesn't get +them and one of them does and if the + + align:start position:0% +them and one of them does and if the + + + align:start position:0% +them and one of them does and if the +boxes are regulatory factors the + + align:start position:0% +boxes are regulatory factors the + + + align:start position:0% +boxes are regulatory factors the +daughter cell that gets them will go on + + align:start position:0% +daughter cell that gets them will go on + + + align:start position:0% +daughter cell that gets them will go on +to do something different than the one + + align:start position:0% +to do something different than the one + + + align:start position:0% +to do something different than the one +that doesn't and you can get two + + align:start position:0% +that doesn't and you can get two + + + align:start position:0% +that doesn't and you can get two +different cell types coming out of this + + align:start position:0% +different cell types coming out of this + + + align:start position:0% +different cell types coming out of this +and I've listed examples of the many + + align:start position:0% +and I've listed examples of the many + + + align:start position:0% +and I've listed examples of the many +different kinds of factors that can be + + align:start position:0% +different kinds of factors that can be + + + align:start position:0% +different kinds of factors that can be +determinance here's a real + + align:start position:0% +determinance here's a real + + + align:start position:0% +determinance here's a real +example this is an early worm embrio + + align:start position:0% +example this is an early worm embrio + + + align:start position:0% +example this is an early worm embrio +remember I told you about Professor + + align:start position:0% +remember I told you about Professor + + + align:start position:0% +remember I told you about Professor +horvitz who got the Nobel Prize for + + align:start position:0% +horvitz who got the Nobel Prize for + + + align:start position:0% +horvitz who got the Nobel Prize for +discovering cell death Pro cesses this + + align:start position:0% +discovering cell death Pro cesses this + + + align:start position:0% +discovering cell death Pro cesses this +is the same animal he works on and on + + align:start position:0% +is the same animal he works on and on + + + align:start position:0% +is the same animal he works on and on +the top + + align:start position:0% +the top + + + align:start position:0% +the top +panels are nuclei stained in blue with + + align:start position:0% +panels are nuclei stained in blue with + + + align:start position:0% +panels are nuclei stained in blue with +this die called dappy here's the zygote + + align:start position:0% +this die called dappy here's the zygote + + + align:start position:0% +this die called dappy here's the zygote +here's the two cell embryo and the 32 + + align:start position:0% +here's the two cell embryo and the 32 + + + align:start position:0% +here's the two cell embryo and the 32 +cell embryo and you can see that there's + + align:start position:0% +cell embryo and you can see that there's + + + align:start position:0% +cell embryo and you can see that there's +a nucleus in every cell okay on the + + align:start position:0% +a nucleus in every cell okay on the + + + align:start position:0% +a nucleus in every cell okay on the +bottom are some determinants that are + + align:start position:0% +bottom are some determinants that are + + + align:start position:0% +bottom are some determinants that are +called P granules P granules are + + align:start position:0% +called P granules P granules are + + + align:start position:0% +called P granules P granules are +Composites of protein and RNA and they + + align:start position:0% +Composites of protein and RNA and they + + + align:start position:0% +Composites of protein and RNA and they +are Regulators of where the future germs + + align:start position:0% +are Regulators of where the future germs + + + align:start position:0% +are Regulators of where the future germs +cells will form the future egg and sperm + + align:start position:0% +cells will form the future egg and sperm + + + align:start position:0% +cells will form the future egg and sperm +look how these ger look how these P + + align:start position:0% +look how these ger look how these P + + + align:start position:0% +look how these ger look how these P +granules segregate during development + + align:start position:0% +granules segregate during development + + + align:start position:0% +granules segregate during development +here they are on one side of the embryo + + align:start position:0% +here they are on one side of the embryo + + + align:start position:0% +here they are on one side of the embryo +even in the zygote and then the zygote + + align:start position:0% +even in the zygote and then the zygote + + + align:start position:0% +even in the zygote and then the zygote +splits look one of the two cells gets + + align:start position:0% +splits look one of the two cells gets + + + align:start position:0% +splits look one of the two cells gets +them all and the other does nothing and + + align:start position:0% +them all and the other does nothing and + + + align:start position:0% +them all and the other does nothing and +at the 32 cell stage there is one cell + + align:start position:0% +at the 32 cell stage there is one cell + + + align:start position:0% +at the 32 cell stage there is one cell +out of 32 that has all of the P granules + + align:start position:0% +out of 32 that has all of the P granules + + + align:start position:0% +out of 32 that has all of the P granules +and they've been excluded or degraded + + align:start position:0% +and they've been excluded or degraded + + + align:start position:0% +and they've been excluded or degraded +from the rest of the embryo okay and + + align:start position:0% +from the rest of the embryo okay and + + + align:start position:0% +from the rest of the embryo okay and +that is a really beautiful example + + align:start position:0% +that is a really beautiful example + + + align:start position:0% +that is a really beautiful example +perhaps the most beautiful example of + + align:start position:0% +perhaps the most beautiful example of + + + align:start position:0% +perhaps the most beautiful example of +determinant + + align:start position:0% +determinant + + + align:start position:0% +determinant +segregating here's another one the + + align:start position:0% +segregating here's another one the + + + align:start position:0% +segregating here's another one the +signaling effect is secreted by + + align:start position:0% +signaling effect is secreted by + + + align:start position:0% +signaling effect is secreted by +neighboring cells uncommitted cells over + + align:start position:0% +neighboring cells uncommitted cells over + + + align:start position:0% +neighboring cells uncommitted cells over +time will do something there's enough + + align:start position:0% +time will do something there's enough + + + align:start position:0% +time will do something there's enough +transcription factors and Regulatory + + align:start position:0% +transcription factors and Regulatory + + + align:start position:0% +transcription factors and Regulatory +factors in all cells that over time + + align:start position:0% +factors in all cells that over time + + + align:start position:0% +factors in all cells that over time +they'll go on to differentiate into + + align:start position:0% +they'll go on to differentiate into + + + align:start position:0% +they'll go on to differentiate into +something if they're normal cells but + + align:start position:0% +something if they're normal cells but + + + align:start position:0% +something if they're normal cells but +here's a signaling cell telling an + + align:start position:0% +here's a signaling cell telling an + + + align:start position:0% +here's a signaling cell telling an +uncommitted cell to activate a signaling + + align:start position:0% +uncommitted cell to activate a signaling + + + align:start position:0% +uncommitted cell to activate a signaling +pathway and go on and make cell type two + + align:start position:0% +pathway and go on and make cell type two + + + align:start position:0% +pathway and go on and make cell type two +okay and these are the inducers which + + align:start position:0% +okay and these are the inducers which + + + align:start position:0% +okay and these are the inducers which +are lians binding to receptors and + + align:start position:0% +are lians binding to receptors and + + + align:start position:0% +are lians binding to receptors and +changing + + align:start position:0% +changing + + + align:start position:0% +changing +sulfate these signaling Pathways can act + + align:start position:0% +sulfate these signaling Pathways can act + + + align:start position:0% +sulfate these signaling Pathways can act +in a concentration dependent + + align:start position:0% +in a concentration dependent + + + align:start position:0% +in a concentration dependent +way as seen on that + + align:start position:0% +way as seen on that + + + align:start position:0% +way as seen on that +screen and here is the notion of a + + align:start position:0% +screen and here is the notion of a + + + align:start position:0% +screen and here is the notion of a +morphogen where High liand concentration + + align:start position:0% +morphogen where High liand concentration + + + align:start position:0% +morphogen where High liand concentration +will give an output of cell type two and + + align:start position:0% +will give an output of cell type two and + + + align:start position:0% +will give an output of cell type two and +low Lian concentration an output of cell + + align:start position:0% +low Lian concentration an output of cell + + + align:start position:0% +low Lian concentration an output of cell +type 3 and we touched on how this works + + align:start position:0% +type 3 and we touched on how this works + + + align:start position:0% +type 3 and we touched on how this works +molecularly previously it's not well + + align:start position:0% +molecularly previously it's not well + + + align:start position:0% +molecularly previously it's not well +understood and is + + align:start position:0% + + + + align:start position:0% + +complicated this is the most famous + + align:start position:0% +complicated this is the most famous + + + align:start position:0% +complicated this is the most famous +example of cells that can go on and tell + + align:start position:0% +example of cells that can go on and tell + + + align:start position:0% +example of cells that can go on and tell +other cells what to become it's a group + + align:start position:0% +other cells what to become it's a group + + + align:start position:0% +other cells what to become it's a group +of cells that was termed the organizer + + align:start position:0% +of cells that was termed the organizer + + + align:start position:0% +of cells that was termed the organizer +before it was clear that there were + + align:start position:0% +before it was clear that there were + + + align:start position:0% +before it was clear that there were +actually lots of organizers and the + + align:start position:0% +actually lots of organizers and the + + + align:start position:0% +actually lots of organizers and the +organizer was defined by a graduate + + align:start position:0% +organizer was defined by a graduate + + + align:start position:0% +organizer was defined by a graduate +student Hilda Mangold together with her + + align:start position:0% +student Hilda Mangold together with her + + + align:start position:0% +student Hilda Mangold together with her +advisor hunt spaman Mangold + + align:start position:0% +advisor hunt spaman Mangold + + + align:start position:0% +advisor hunt spaman Mangold +unfortunately went on and and was killed + + align:start position:0% +unfortunately went on and and was killed + + + align:start position:0% +unfortunately went on and and was killed +in an explosion Shaman went on to get + + align:start position:0% +in an explosion Shaman went on to get + + + align:start position:0% +in an explosion Shaman went on to get +the first Nobel Prize for developmental + + align:start position:0% +the first Nobel Prize for developmental + + + align:start position:0% +the first Nobel Prize for developmental +biology in 1935 it's never seemed Fair + + align:start position:0% +biology in 1935 it's never seemed Fair + + + align:start position:0% +biology in 1935 it's never seemed Fair +it isn't fair anyway um that was the + + align:start position:0% +it isn't fair anyway um that was the + + + align:start position:0% +it isn't fair anyway um that was the +that is the sad story Shan was the + + align:start position:0% +that is the sad story Shan was the + + + align:start position:0% +that is the sad story Shan was the +preeminent developmental biologist in + + align:start position:0% +preeminent developmental biologist in + + + align:start position:0% +preeminent developmental biologist in +the 1920s and this is the finding that + + align:start position:0% +the 1920s and this is the finding that + + + align:start position:0% +the 1920s and this is the finding that +Dr Mangold made she took an embryo and + + align:start position:0% +Dr Mangold made she took an embryo and + + + align:start position:0% +Dr Mangold made she took an embryo and +she removed from the embryo + + align:start position:0% +she removed from the embryo + + + align:start position:0% +she removed from the embryo +see not only do you see my calendar you + + align:start position:0% +see not only do you see my calendar you + + + align:start position:0% +see not only do you see my calendar you +get an insight into the rest of my life + + align:start position:0% +get an insight into the rest of my life + + + align:start position:0% +get an insight into the rest of my life +okay my husband is a professor over at + + align:start position:0% +okay my husband is a professor over at + + + align:start position:0% +okay my husband is a professor over at +that other + + align:start position:0% +that other + + + align:start position:0% +that other +university + + align:start position:0% +university + + + align:start position:0% +university +so we have competing teaching schedules + + align:start position:0% +so we have competing teaching schedules + + + align:start position:0% +so we have competing teaching schedules +today all right so Dr Mangold took a + + align:start position:0% +today all right so Dr Mangold took a + + + align:start position:0% +today all right so Dr Mangold took a +group of cells from the future back of + + align:start position:0% +group of cells from the future back of + + + align:start position:0% +group of cells from the future back of +the embryo we'll talk about this next + + align:start position:0% +the embryo we'll talk about this next + + + align:start position:0% +the embryo we'll talk about this next +time and she transplanted them into + + align:start position:0% +time and she transplanted them into + + + align:start position:0% +time and she transplanted them into +another embryo she transplanted them + + align:start position:0% +another embryo she transplanted them + + + align:start position:0% +another embryo she transplanted them +into the belly so she took back cells + + align:start position:0% +into the belly so she took back cells + + + align:start position:0% +into the belly so she took back cells +and put them in the future belly of a + + align:start position:0% +and put them in the future belly of a + + + align:start position:0% +and put them in the future belly of a +host embryo so there's a donor and a + + align:start position:0% +host embryo so there's a donor and a + + + align:start position:0% +host embryo so there's a donor and a +host and she could see the difference + + align:start position:0% +host and she could see the difference + + + align:start position:0% +host and she could see the difference +between these embryos because they had + + align:start position:0% +between these embryos because they had + + + align:start position:0% +between these embryos because they had +different pigmentation they were + + align:start position:0% +different pigmentation they were + + + align:start position:0% +different pigmentation they were +different + + align:start position:0% +different + + + align:start position:0% +different +colors and then she let them go on and + + align:start position:0% +colors and then she let them go on and + + + align:start position:0% +colors and then she let them go on and +develop and this was a hugely difficult + + align:start position:0% +develop and this was a hugely difficult + + + align:start position:0% +develop and this was a hugely difficult +experiment in those days for technical + + align:start position:0% +experiment in those days for technical + + + align:start position:0% +experiment in those days for technical +reasons but over a period of a couple of + + align:start position:0% +reasons but over a period of a couple of + + + align:start position:0% +reasons but over a period of a couple of +months these embryos developed and what + + align:start position:0% +months these embryos developed and what + + + align:start position:0% +months these embryos developed and what +she found was this peculiar embryo which + + align:start position:0% +she found was this peculiar embryo which + + + align:start position:0% +she found was this peculiar embryo which +is a conjoined twin + + align:start position:0% +is a conjoined twin + + + align:start position:0% +is a conjoined twin +and she could show by looking to see + + align:start position:0% +and she could show by looking to see + + + align:start position:0% +and she could show by looking to see +where the cells she had transplanted in + + align:start position:0% +where the cells she had transplanted in + + + align:start position:0% +where the cells she had transplanted in +were that there was this host embryo + + align:start position:0% +were that there was this host embryo + + + align:start position:0% +were that there was this host embryo +that was made of all the original host + + align:start position:0% +that was made of all the original host + + + align:start position:0% +that was made of all the original host +tissue and there was another embryo + + align:start position:0% +tissue and there was another embryo + + + align:start position:0% +tissue and there was another embryo +joined to it in this + + align:start position:0% +joined to it in this + + + align:start position:0% +joined to it in this +orientation but that only a little bit + + align:start position:0% +orientation but that only a little bit + + + align:start position:0% +orientation but that only a little bit +of the second embryo actually came from + + align:start position:0% +of the second embryo actually came from + + + align:start position:0% +of the second embryo actually came from +the donor + + align:start position:0% +the donor + + + align:start position:0% +the donor +cells most of the second embryo came + + align:start position:0% +cells most of the second embryo came + + + align:start position:0% +cells most of the second embryo came +from the host cells and this was epipal + + align:start position:0% +from the host cells and this was epipal + + + align:start position:0% +from the host cells and this was epipal +because she could understand that those + + align:start position:0% +because she could understand that those + + + align:start position:0% +because she could understand that those +donor cells had told the host tissue to + + align:start position:0% +donor cells had told the host tissue to + + + align:start position:0% +donor cells had told the host tissue to +make another embryo it was an + + align:start position:0% +make another embryo it was an + + + align:start position:0% +make another embryo it was an +extraordinary unprecedented finding and + + align:start position:0% +extraordinary unprecedented finding and + + + align:start position:0% +extraordinary unprecedented finding and +it + + align:start position:0% +it + + + align:start position:0% +it +gave the notion that cells can tell + + align:start position:0% +gave the notion that cells can tell + + + align:start position:0% +gave the notion that cells can tell +other cells what to become does this + + align:start position:0% +other cells what to become does this + + + align:start position:0% +other cells what to become does this +happen in other animals for sure this is + + align:start position:0% +happen in other animals for sure this is + + + align:start position:0% +happen in other animals for sure this is +from a colleague of mine Jerry Thompson + + align:start position:0% +from a colleague of mine Jerry Thompson + + + align:start position:0% +from a colleague of mine Jerry Thompson +who made these conjoined twinned frog + + align:start position:0% +who made these conjoined twinned frog + + + align:start position:0% +who made these conjoined twinned frog +embryos by organizer + + align:start position:0% +embryos by organizer + + + align:start position:0% +embryos by organizer +transplants does it happen in humans it + + align:start position:0% +transplants does it happen in humans it + + + align:start position:0% +transplants does it happen in humans it +does conjoin twins come from we believe + + align:start position:0% +does conjoin twins come from we believe + + + align:start position:0% +does conjoin twins come from we believe +organizers that have split and have + + align:start position:0% +organizers that have split and have + + + align:start position:0% +organizers that have split and have +given rise to two embryos which don't + + align:start position:0% +given rise to two embryos which don't + + + align:start position:0% +given rise to two embryos which don't +separate properly from one + + align:start position:0% +separate properly from one + + + align:start position:0% +separate properly from one +another okay and we will stop there and + + align:start position:0% +another okay and we will stop there and + + + align:start position:0% +another okay and we will stop there and +continue + + align:start position:0% +continue + + + align:start position:0% +continue +on Monday \ No newline at end of file diff --git a/BZwdYmPS5f8.txt b/BZwdYmPS5f8.txt new file mode 100644 index 0000000000000000000000000000000000000000..1ccad6f670bb1e45ac5ed3c105ed1ce938e75b29 --- /dev/null +++ b/BZwdYmPS5f8.txt @@ -0,0 +1,1947 @@ +align:start position:0% + +hi open course whereare Learners we've + + align:start position:0% +hi open course whereare Learners we've + + + align:start position:0% +hi open course whereare Learners we've +gotten to the part of the first lecture + + align:start position:0% +gotten to the part of the first lecture + + + align:start position:0% +gotten to the part of the first lecture +where the technical difficulties made it + + align:start position:0% +where the technical difficulties made it + + + align:start position:0% +where the technical difficulties made it +little too hard to follow what was + + align:start position:0% +little too hard to follow what was + + + align:start position:0% +little too hard to follow what was +happening there so I'm going to uh + + align:start position:0% +happening there so I'm going to uh + + + align:start position:0% +happening there so I'm going to uh +re-record what we all did as the opening + + align:start position:0% +re-record what we all did as the opening + + + align:start position:0% +re-record what we all did as the opening +of the class to begin go ahead and go to + + align:start position:0% +of the class to begin go ahead and go to + + + align:start position:0% +of the class to begin go ahead and go to +the URL on the screen right now this is + + align:start position:0% +the URL on the screen right now this is + + + align:start position:0% +the URL on the screen right now this is +a project from Google called collab that + + align:start position:0% +a project from Google called collab that + + + align:start position:0% +a project from Google called collab that +allows you to run Python scripts + + align:start position:0% +allows you to run Python scripts + + + align:start position:0% +allows you to run Python scripts +including music 21 in your own browser + + align:start position:0% +including music 21 in your own browser + + + align:start position:0% +including music 21 in your own browser +without installing anything on your + + align:start position:0% +without installing anything on your + + + align:start position:0% +without installing anything on your +computer + + align:start position:0% +computer + + + align:start position:0% +computer +so so go ahead and click this play + + align:start position:0% +so so go ahead and click this play + + + align:start position:0% +so so go ahead and click this play +button you're going to see a warning + + align:start position:0% +button you're going to see a warning + + + align:start position:0% +button you're going to see a warning +that uh Google didn't write this + + align:start position:0% +that uh Google didn't write this + + + align:start position:0% +that uh Google didn't write this +notebook I did U it's I think it's + + align:start position:0% +notebook I did U it's I think it's + + + align:start position:0% +notebook I did U it's I think it's +pretty safe what it does is it installs + + align:start position:0% +pretty safe what it does is it installs + + + align:start position:0% +pretty safe what it does is it installs +the latest version of music 21 and Muse + + align:start position:0% +the latest version of music 21 and Muse + + + align:start position:0% +the latest version of music 21 and Muse +score and some other software needed to + + align:start position:0% +score and some other software needed to + + + align:start position:0% +score and some other software needed to +uh run some of the tools we're going to + + align:start position:0% +uh run some of the tools we're going to + + + align:start position:0% +uh run some of the tools we're going to +be using without installing python on + + align:start position:0% +be using without installing python on + + + align:start position:0% +be using without installing python on +your computer Google already has a copy + + align:start position:0% +your computer Google already has a copy + + + align:start position:0% +your computer Google already has a copy +of Music 21 but this just uh brings you + + align:start position:0% +of Music 21 but this just uh brings you + + + align:start position:0% +of Music 21 but this just uh brings you +to the latest + + align:start position:0% +to the latest + + + align:start position:0% +to the latest +version and go ahead and pause and we'll + + align:start position:0% +version and go ahead and pause and we'll + + + align:start position:0% +version and go ahead and pause and we'll +come back after it's all installed + + align:start position:0% + + + + align:start position:0% + +welcome back I hope that the cells + + align:start position:0% +welcome back I hope that the cells + + + align:start position:0% +welcome back I hope that the cells +aren't um running anymore so we can + + align:start position:0% +aren't um running anymore so we can + + + align:start position:0% +aren't um running anymore so we can +start uh coming in if you've never used + + align:start position:0% +start uh coming in if you've never used + + + align:start position:0% +start uh coming in if you've never used +a Jupiter notebook or another online + + align:start position:0% +a Jupiter notebook or another online + + + align:start position:0% +a Jupiter notebook or another online +collaborative environment the important + + align:start position:0% +collaborative environment the important + + + align:start position:0% +collaborative environment the important +thing that you're going to need is to be + + align:start position:0% +thing that you're going to need is to be + + + align:start position:0% +thing that you're going to need is to be +clicking into these cells the gray ones + + align:start position:0% +clicking into these cells the gray ones + + + align:start position:0% +clicking into these cells the gray ones +are where U type and the uh ones with a + + align:start position:0% +are where U type and the uh ones with a + + + align:start position:0% +are where U type and the uh ones with a +white or black background are the ones + + align:start position:0% +white or black background are the ones + + + align:start position:0% +white or black background are the ones +where uh output's coming out in order to + + align:start position:0% +where uh output's coming out in order to + + + align:start position:0% +where uh output's coming out in order to +run a cell you just type shift and + + align:start position:0% +run a cell you just type shift and + + + align:start position:0% +run a cell you just type shift and +return or shift and enter so what we're + + align:start position:0% +return or shift and enter so what we're + + + align:start position:0% +return or shift and enter so what we're +going to do is I'm just going to um + + align:start position:0% +going to do is I'm just going to um + + + align:start position:0% +going to do is I'm just going to um +click into this cell and hit shift enter + + align:start position:0% +click into this cell and hit shift enter + + + align:start position:0% +click into this cell and hit shift enter +and this will make sure that music 21 + + align:start position:0% +and this will make sure that music 21 + + + align:start position:0% +and this will make sure that music 21 +actually works sometimes the first time + + align:start position:0% +actually works sometimes the first time + + + align:start position:0% +actually works sometimes the first time +you show a score it um it doesn't work + + align:start position:0% +you show a score it um it doesn't work + + + align:start position:0% +you show a score it um it doesn't work +as well and on some browsers this will + + align:start position:0% +as well and on some browsers this will + + + align:start position:0% +as well and on some browsers this will +work um you can listen to a score + + align:start position:0% +work um you can listen to a score + + + align:start position:0% +work um you can listen to a score +and we's see if this works or + + align:start position:0% +and we's see if this works or + + + align:start position:0% +and we's see if this works or +not there we go and now we're ready to + + align:start position:0% +not there we go and now we're ready to + + + align:start position:0% +not there we go and now we're ready to +actually begin uh we're not going to + + align:start position:0% +actually begin uh we're not going to + + + align:start position:0% +actually begin uh we're not going to +generate with AI today we'll write our + + align:start position:0% +generate with AI today we'll write our + + + align:start position:0% +generate with AI today we'll write our +own + + align:start position:0% +own + + + align:start position:0% +own +scores so with you're with me we're + + align:start position:0% +scores so with you're with me we're + + + align:start position:0% +scores so with you're with me we're +going to start uh anything where you're + + align:start position:0% +going to start uh anything where you're + + + align:start position:0% +going to start uh anything where you're +doing a python session by importing the + + align:start position:0% +doing a python session by importing the + + + align:start position:0% +doing a python session by importing the +code that's useful and for this one it's + + align:start position:0% +code that's useful and for this one it's + + + align:start position:0% +code that's useful and for this one it's +uh the music21 toolkit so we're going to + + align:start position:0% +uh the music21 toolkit so we're going to + + + align:start position:0% +uh the music21 toolkit so we're going to +import everything from it if you're + + align:start position:0% +import everything from it if you're + + + align:start position:0% +import everything from it if you're +somebody who done a lot of python and + + align:start position:0% +somebody who done a lot of python and + + + align:start position:0% +somebody who done a lot of python and +cares about things like polluting your + + align:start position:0% +cares about things like polluting your + + + align:start position:0% +cares about things like polluting your +namespace you can do individual mod + + align:start position:0% +namespace you can do individual mod + + + align:start position:0% +namespace you can do individual mod +modules but I'm always going to do it as + + align:start position:0% +modules but I'm always going to do it as + + + align:start position:0% +modules but I'm always going to do it as +if we have all the parts of Music 21 at + + align:start position:0% +if we have all the parts of Music 21 at + + + align:start position:0% +if we have all the parts of Music 21 at +your + + align:start position:0% + + + + align:start position:0% + +fingertips so we're going to load a + + align:start position:0% +fingertips so we're going to load a + + + align:start position:0% +fingertips so we're going to load a +Corral by Johan Johan Sebastian Bach + + align:start position:0% +Corral by Johan Johan Sebastian Bach + + + align:start position:0% +Corral by Johan Johan Sebastian Bach +it's a shortest Corral called bwv 66.6 + + align:start position:0% +it's a shortest Corral called bwv 66.6 + + + align:start position:0% +it's a shortest Corral called bwv 66.6 +so first I'll create a variable call it + + align:start position:0% +so first I'll create a variable call it + + + align:start position:0% +so first I'll create a variable call it +boach and we'll use the Corpus tool from + + align:start position:0% +boach and we'll use the Corpus tool from + + + align:start position:0% +boach and we'll use the Corpus tool from +music 21 and it's parse function to load + + align:start position:0% +music 21 and it's parse function to load + + + align:start position:0% +music 21 and it's parse function to load +in Bach bwv 6 6.6 I'll hit shift enter + + align:start position:0% +in Bach bwv 6 6.6 I'll hit shift enter + + + align:start position:0% +in Bach bwv 6 6.6 I'll hit shift enter +and it's assigned to boach and we can + + align:start position:0% +and it's assigned to boach and we can + + + align:start position:0% +and it's assigned to boach and we can +call the method show on it to see the + + align:start position:0% +call the method show on it to see the + + + align:start position:0% +call the method show on it to see the +score of that Yep looks like a crow by + + align:start position:0% +score of that Yep looks like a crow by + + + align:start position:0% +score of that Yep looks like a crow by +Bach and you can see that has soprano + + align:start position:0% +Bach and you can see that has soprano + + + align:start position:0% +Bach and you can see that has soprano +Alto tenor base and we can get the alter + + align:start position:0% +Alto tenor base and we can get the alter + + + align:start position:0% +Alto tenor base and we can get the alter +part by saying um bach. Parts square + + align:start position:0% +part by saying um bach. Parts square + + + align:start position:0% +part by saying um bach. Parts square +brackets open Alto and we'll just show + + align:start position:0% +brackets open Alto and we'll just show + + + align:start position:0% +brackets open Alto and we'll just show +that + + align:start position:0% + + + + align:start position:0% + +yes looks like the Alto part now we'll + + align:start position:0% +yes looks like the Alto part now we'll + + + align:start position:0% +yes looks like the Alto part now we'll +get the soprano part and assign it to a + + align:start position:0% +get the soprano part and assign it to a + + + align:start position:0% +get the soprano part and assign it to a +variable sop for soprano and we'll just + + align:start position:0% +variable sop for soprano and we'll just + + + align:start position:0% +variable sop for soprano and we'll just +do that instead this time we'll get it + + align:start position:0% +do that instead this time we'll get it + + + align:start position:0% +do that instead this time we'll get it +by doing the part number and so it's the + + align:start position:0% +by doing the part number and so it's the + + + align:start position:0% +by doing the part number and so it's the +first part and so in Python that means + + align:start position:0% +first part and so in Python that means + + + align:start position:0% +first part and so in Python that means +it's part zero Parts zero and one of the + + align:start position:0% +it's part zero Parts zero and one of the + + + align:start position:0% +it's part zero Parts zero and one of the +things that we do in music 21 is when + + align:start position:0% +things that we do in music 21 is when + + + align:start position:0% +things that we do in music 21 is when +something is in a programmer + + align:start position:0% +something is in a programmer + + + align:start position:0% +something is in a programmer +rule we follow um the conventions of + + align:start position:0% +rule we follow um the conventions of + + + align:start position:0% +rule we follow um the conventions of +programming where everything starts with + + align:start position:0% +programming where everything starts with + + + align:start position:0% +programming where everything starts with +zero and when we're in musician space + + align:start position:0% +zero and when we're in musician space + + + align:start position:0% +zero and when we're in musician space +such as talking about measures we don't + + align:start position:0% +such as talking about measures we don't + + + align:start position:0% +such as talking about measures we don't +subtract one from the measure number or + + align:start position:0% +subtract one from the measure number or + + + align:start position:0% +subtract one from the measure number or +anything like that so if we wanted to + + align:start position:0% +anything like that so if we wanted to + + + align:start position:0% +anything like that so if we wanted to +just see measures 3 through five + + align:start position:0% +just see measures 3 through five + + + align:start position:0% +just see measures 3 through five +inclusive of the soprano part we could + + align:start position:0% +inclusive of the soprano part we could + + + align:start position:0% +inclusive of the soprano part we could +do something like that + + align:start position:0% +do something like that + + + align:start position:0% +do something like that +oops or we could type the word measure + + align:start position:0% +oops or we could type the word measure + + + align:start position:0% +oops or we could type the word measure +properly and then we'll get that measure + + align:start position:0% +properly and then we'll get that measure + + + align:start position:0% +properly and then we'll get that measure +just gets a single measure this one got + + align:start position:0% +just gets a single measure this one got + + + align:start position:0% +just gets a single measure this one got +that great and um in fact we'll use the + + align:start position:0% +that great and um in fact we'll use the + + + align:start position:0% +that great and um in fact we'll use the +measure thing now and we'll get in + + align:start position:0% +measure thing now and we'll get in + + + align:start position:0% +measure thing now and we'll get in +measure five the zero first second note + + align:start position:0% +measure five the zero first second note + + + align:start position:0% +measure five the zero first second note +the one with the forada on it and so + + align:start position:0% +the one with the forada on it and so + + + align:start position:0% +the one with the forada on it and so +we'll call it C because it's a c + + align:start position:0% +we'll call it C because it's a c + + + align:start position:0% +we'll call it C because it's a c +actually it's a C sharp but um well + + align:start position:0% +actually it's a C sharp but um well + + + align:start position:0% +actually it's a C sharp but um well +we'll see why not and so we'll get notes + + align:start position:0% +we'll see why not and so we'll get notes + + + align:start position:0% +we'll see why not and so we'll get notes +number + + align:start position:0% +number + + + align:start position:0% +number +two if we called it C + + align:start position:0% +two if we called it C + + + align:start position:0% +two if we called it C +then everything after this would be a + + align:start position:0% +then everything after this would be a + + + align:start position:0% +then everything after this would be a +common so that doesn't work so we'll + + align:start position:0% +common so that doesn't work so we'll + + + align:start position:0% +common so that doesn't work so we'll +just call it c um and now what we can do + + align:start position:0% +just call it c um and now what we can do + + + align:start position:0% +just call it c um and now what we can do +is manipulate it change its style it's + + align:start position:0% +is manipulate it change its style it's + + + align:start position:0% +is manipulate it change its style it's +color to + + align:start position:0% +color to + + + align:start position:0% +color to +red and now when I show the soprano part + + align:start position:0% +red and now when I show the soprano part + + + align:start position:0% +red and now when I show the soprano part +because uh they're all linked to each + + align:start position:0% +because uh they're all linked to each + + + align:start position:0% +because uh they're all linked to each +other we should see yep there's a note + + align:start position:0% +other we should see yep there's a note + + + align:start position:0% +other we should see yep there's a note +that's in + + align:start position:0% + + + + align:start position:0% + +Red so that's how we can manipulate a + + align:start position:0% +Red so that's how we can manipulate a + + + align:start position:0% +Red so that's how we can manipulate a +score and now let's see how we can do + + align:start position:0% +score and now let's see how we can do + + + align:start position:0% +score and now let's see how we can do +some analytical functions on things so + + align:start position:0% +some analytical functions on things so + + + align:start position:0% +some analytical functions on things so +let's do Baka analyze and we'll analyze + + align:start position:0% +let's do Baka analyze and we'll analyze + + + align:start position:0% +let's do Baka analyze and we'll analyze +the key of the + + align:start position:0% +the key of the + + + align:start position:0% +the key of the +piece and it says it returns a key + + align:start position:0% +piece and it says it returns a key + + + align:start position:0% +piece and it says it returns a key +object that says it's in F minor and one + + align:start position:0% +object that says it's in F minor and one + + + align:start position:0% +object that says it's in F minor and one +of the things I really want to emphasize + + align:start position:0% +of the things I really want to emphasize + + + align:start position:0% +of the things I really want to emphasize +is always go back and do the smell test + + align:start position:0% +is always go back and do the smell test + + + align:start position:0% +is always go back and do the smell test +is this true ises it look like baloney + + align:start position:0% +is this true ises it look like baloney + + + align:start position:0% +is this true ises it look like baloney +and we can kind of see well begins in a + + align:start position:0% +and we can kind of see well begins in a + + + align:start position:0% +and we can kind of see well begins in a +but it does have three Sharps and at the + + align:start position:0% +but it does have three Sharps and at the + + + align:start position:0% +but it does have three Sharps and at the +end yep there is an FP in the base so + + align:start position:0% +end yep there is an FP in the base so + + + align:start position:0% +end yep there is an FP in the base so +looks kind of like F major but yeah okay + + align:start position:0% +looks kind of like F major but yeah okay + + + align:start position:0% +looks kind of like F major but yeah okay +here some F minor okay it kind of passes + + align:start position:0% +here some F minor okay it kind of passes + + + align:start position:0% +here some F minor okay it kind of passes +the spell tests and we'll see why that's + + align:start position:0% +the spell tests and we'll see why that's + + + align:start position:0% +the spell tests and we'll see why that's +so important in just a little bit but it + + align:start position:0% +so important in just a little bit but it + + + align:start position:0% +so important in just a little bit but it +did seem like it was beginning in a so + + align:start position:0% +did seem like it was beginning in a so + + + align:start position:0% +did seem like it was beginning in a so +we can just analyze a portion of that so + + align:start position:0% +we can just analyze a portion of that so + + + align:start position:0% +we can just analyze a portion of that so +we'll do B measures zero because we want + + align:start position:0% +we'll do B measures zero because we want + + + align:start position:0% +we'll do B measures zero because we want +the pickup measure and two and we'll + + align:start position:0% +the pickup measure and two and we'll + + + align:start position:0% +the pickup measure and two and we'll +analyze the of just that + + align:start position:0% +analyze the of just that + + + align:start position:0% +analyze the of just that +passage uh does seem to start in a + + align:start position:0% + + + + align:start position:0% + +major let's do something that seems + + align:start position:0% +major let's do something that seems + + + align:start position:0% +major let's do something that seems +pretty simple let's count the number of + + align:start position:0% +pretty simple let's count the number of + + + align:start position:0% +pretty simple let's count the number of +notes in the piece so we can just do Len + + align:start position:0% +notes in the piece so we can just do Len + + + align:start position:0% +notes in the piece so we can just do Len +bach. notes that just gets uh all the + + align:start position:0% +bach. notes that just gets uh all the + + + align:start position:0% +bach. notes that just gets uh all the +notes the piece in another language + + align:start position:0% +notes the piece in another language + + + align:start position:0% +notes the piece in another language +would be bl. notes. length and I don't + + align:start position:0% +would be bl. notes. length and I don't + + + align:start position:0% +would be bl. notes. length and I don't +know + + align:start position:0% +know + + + align:start position:0% +know +um I don't know how many notes are in + + align:start position:0% +um I don't know how many notes are in + + + align:start position:0% +um I don't know how many notes are in +the piece but I'm pretty sure it's more + + align:start position:0% +the piece but I'm pretty sure it's more + + + align:start position:0% +the piece but I'm pretty sure it's more +than zero and the Reas reason for this + + align:start position:0% +than zero and the Reas reason for this + + + align:start position:0% +than zero and the Reas reason for this +is that music 21 and most ways of + + align:start position:0% +is that music 21 and most ways of + + + align:start position:0% +is that music 21 and most ways of +conceiving music on the computer don't + + align:start position:0% +conceiving music on the computer don't + + + align:start position:0% +conceiving music on the computer don't +think of the score as having notes the + + align:start position:0% +think of the score as having notes the + + + align:start position:0% +think of the score as having notes the +score has Parts the parts have measures + + align:start position:0% +score has Parts the parts have measures + + + align:start position:0% +score has Parts the parts have measures +and the measures have notes so what we + + align:start position:0% +and the measures have notes so what we + + + align:start position:0% +and the measures have notes so what we +could do is get the length of Bach Parts + + align:start position:0% +could do is get the length of Bach Parts + + + align:start position:0% +could do is get the length of Bach Parts +one measure two do notes and see okay + + align:start position:0% +one measure two do notes and see okay + + + align:start position:0% +one measure two do notes and see okay +that passes the smell test so what we + + align:start position:0% +that passes the smell test so what we + + + align:start position:0% +that passes the smell test so what we +can do instead is we can use something + + align:start position:0% +can do instead is we can use something + + + align:start position:0% +can do instead is we can use something +called recurse so we'll get the bach. + + align:start position:0% +called recurse so we'll get the bach. + + + align:start position:0% +called recurse so we'll get the bach. +recurse that's a function or a method + + align:start position:0% +recurse that's a function or a method + + + align:start position:0% +recurse that's a function or a method +and we get the notes on that and what + + align:start position:0% +and we get the notes on that and what + + + align:start position:0% +and we get the notes on that and what +recurse says is open up every box you + + align:start position:0% +recurse says is open up every box you + + + align:start position:0% +recurse says is open up every box you +get to a part open it up look inside for + + align:start position:0% +get to a part open it up look inside for + + + align:start position:0% +get to a part open it up look inside for +measures open it up and keep going until + + align:start position:0% +measures open it up and keep going until + + + align:start position:0% +measures open it up and keep going until +you find + + align:start position:0% +you find + + + align:start position:0% +you find +notes and 165 notes that seems to pass + + align:start position:0% +notes and 165 notes that seems to pass + + + align:start position:0% +notes and 165 notes that seems to pass +the smell test to + + align:start position:0% +the smell test to + + + align:start position:0% +the smell test to +me right now we've been working with + + align:start position:0% +me right now we've been working with + + + align:start position:0% +me right now we've been working with +this as a series of of parts that are + + align:start position:0% +this as a series of of parts that are + + + align:start position:0% +this as a series of of parts that are +not connected to each other but of + + align:start position:0% +not connected to each other but of + + + align:start position:0% +not connected to each other but of +course there are chords in there also + + align:start position:0% +course there are chords in there also + + + align:start position:0% +course there are chords in there also +but if we do um B Dot and here's another + + align:start position:0% +but if we do um B Dot and here's another + + + align:start position:0% +but if we do um B Dot and here's another +way you can say recurse I want to + + align:start position:0% +way you can say recurse I want to + + + align:start position:0% +way you can say recurse I want to +recurse and get everything that's a + + align:start position:0% +recurse and get everything that's a + + + align:start position:0% +recurse and get everything that's a +chord there are no chords in this piece + + align:start position:0% +chord there are no chords in this piece + + + align:start position:0% +chord there are no chords in this piece +so we have to create some chords using + + align:start position:0% +so we have to create some chords using + + + align:start position:0% +so we have to create some chords using +the chordify method so we'll say core + + align:start position:0% +the chordify method so we'll say core + + + align:start position:0% +the chordify method so we'll say core +for chords equals buck. chordify + + align:start position:0% + + + + align:start position:0% + +and now if we + + align:start position:0% +and now if we + + + align:start position:0% +and now if we +show the cified + + align:start position:0% +show the cified + + + align:start position:0% +show the cified +method and we can see that some of these + + align:start position:0% +method and we can see that some of these + + + align:start position:0% +method and we can see that some of these +notes are way too low to be read + + align:start position:0% +notes are way too low to be read + + + align:start position:0% +notes are way too low to be read +properly and they have duplicated notes + + align:start position:0% +properly and they have duplicated notes + + + align:start position:0% +properly and they have duplicated notes +and things and over the course of the + + align:start position:0% +and things and over the course of the + + + align:start position:0% +and things and over the course of the +semester we'll find ways that we can + + align:start position:0% +semester we'll find ways that we can + + + align:start position:0% +semester we'll find ways that we can +make this a lot more representable + + align:start position:0% +make this a lot more representable + + + align:start position:0% +make this a lot more representable +including things like getting rid of + + align:start position:0% +including things like getting rid of + + + align:start position:0% +including things like getting rid of +passing tones and other things that + + align:start position:0% +passing tones and other things that + + + align:start position:0% +passing tones and other things that +disturb looking at the chords but for + + align:start position:0% +disturb looking at the chords but for + + + align:start position:0% +disturb looking at the chords but for +now we can look at chord chord for the + + align:start position:0% +now we can look at chord chord for the + + + align:start position:0% +now we can look at chord chord for the +chords the number of chords in that and + + align:start position:0% +chords the number of chords in that and + + + align:start position:0% +chords the number of chords in that and +see that yep that looks like a + + align:start position:0% +see that yep that looks like a + + + align:start position:0% +see that yep that looks like a +reasonable + + align:start position:0% +reasonable + + + align:start position:0% +reasonable +number so I hope that gives you a taste + + align:start position:0% +number so I hope that gives you a taste + + + align:start position:0% +number so I hope that gives you a taste +of some of what we're going to be doing + + align:start position:0% +of some of what we're going to be doing + + + align:start position:0% +of some of what we're going to be doing +over the course of the semester of this + + align:start position:0% +over the course of the semester of this + + + align:start position:0% +over the course of the semester of this +class now we've gone very fast through a + + align:start position:0% +class now we've gone very fast through a + + + align:start position:0% +class now we've gone very fast through a +bunch of things but don't worry because + + align:start position:0% +bunch of things but don't worry because + + + align:start position:0% +bunch of things but don't worry because +we're going to lock all those things up + + align:start position:0% +we're going to lock all those things up + + + align:start position:0% +we're going to lock all those things up +cify is going to be locked up anal + + align:start position:0% +cify is going to be locked up anal + + + align:start position:0% +cify is going to be locked up anal +analyze key is going to be locked up and + + align:start position:0% +analyze key is going to be locked up and + + + align:start position:0% +analyze key is going to be locked up and +what mean that means that it won't be + + align:start position:0% +what mean that means that it won't be + + + align:start position:0% +what mean that means that it won't be +available to be used in the rest of the + + align:start position:0% +available to be used in the rest of the + + + align:start position:0% +available to be used in the rest of the +class until it's unlocked again the way + + align:start position:0% +class until it's unlocked again the way + + + align:start position:0% +class until it's unlocked again the way +this class is going to work is all these + + align:start position:0% +this class is going to work is all these + + + align:start position:0% +this class is going to work is all these +analytical tools all these ways of + + align:start position:0% +analytical tools all these ways of + + + align:start position:0% +analytical tools all these ways of +conceiving a score will Begin by being + + align:start position:0% +conceiving a score will Begin by being + + + align:start position:0% +conceiving a score will Begin by being +locked and then you'll do an assignment + + align:start position:0% +locked and then you'll do an assignment + + + align:start position:0% +locked and then you'll do an assignment +either as a problem set or as uh in in + + align:start position:0% +either as a problem set or as uh in in + + + align:start position:0% +either as a problem set or as uh in in +class assignment where we'll figure out + + align:start position:0% +class assignment where we'll figure out + + + align:start position:0% +class assignment where we'll figure out +how does this work what what are the + + align:start position:0% +how does this work what what are the + + + align:start position:0% +how does this work what what are the +ways of doing this and then once you've + + align:start position:0% +ways of doing this and then once you've + + + align:start position:0% +ways of doing this and then once you've +designed your own algorithm for doing + + align:start position:0% +designed your own algorithm for doing + + + align:start position:0% +designed your own algorithm for doing +these things you can either continue to + + align:start position:0% +these things you can either continue to + + + align:start position:0% +these things you can either continue to +use your own algorithm or you will have + + align:start position:0% +use your own algorithm or you will have + + + align:start position:0% +use your own algorithm or you will have +unlocked the music 21 version of the + + align:start position:0% +unlocked the music 21 version of the + + + align:start position:0% +unlocked the music 21 version of the +algorithm and from then on you can use + + align:start position:0% +algorithm and from then on you can use + + + align:start position:0% +algorithm and from then on you can use +that instead so we're going to just be + + align:start position:0% +that instead so we're going to just be + + + align:start position:0% +that instead so we're going to just be +building up knowledge little by little + + align:start position:0% +building up knowledge little by little + + + align:start position:0% +building up knowledge little by little +until we have + + align:start position:0% +until we have + + + align:start position:0% +until we have +everything one of the things that as an + + align:start position:0% +everything one of the things that as an + + + align:start position:0% +everything one of the things that as an +open courseware learner you won't have + + align:start position:0% +open courseware learner you won't have + + + align:start position:0% +open courseware learner you won't have +access to + + align:start position:0% +access to + + + align:start position:0% +access to +is the extremely valuable things that + + align:start position:0% +is the extremely valuable things that + + + align:start position:0% +is the extremely valuable things that +happened outside of class yes coming to + + align:start position:0% +happened outside of class yes coming to + + + align:start position:0% +happened outside of class yes coming to +office hours but mostly with students + + align:start position:0% +office hours but mostly with students + + + align:start position:0% +office hours but mostly with students +helping each other giving each other + + align:start position:0% +helping each other giving each other + + + align:start position:0% +helping each other giving each other +inspiration for projects they could do + + align:start position:0% +inspiration for projects they could do + + + align:start position:0% +inspiration for projects they could do +and helping them through some of the + + align:start position:0% +and helping them through some of the + + + align:start position:0% +and helping them through some of the +more difficult parts of the class so I + + align:start position:0% +more difficult parts of the class so I + + + align:start position:0% +more difficult parts of the class so I +encourage you if you can find somebody + + align:start position:0% +encourage you if you can find somebody + + + align:start position:0% +encourage you if you can find somebody +else online who's also taking the course + + align:start position:0% +else online who's also taking the course + + + align:start position:0% +else online who's also taking the course +or somebody who has taken it in the past + + align:start position:0% +or somebody who has taken it in the past + + + align:start position:0% +or somebody who has taken it in the past +and get to know them that will give you + + align:start position:0% +and get to know them that will give you + + + align:start position:0% +and get to know them that will give you +a lot more of the experience that the + + align:start position:0% +a lot more of the experience that the + + + align:start position:0% +a lot more of the experience that the +students had at MIT when they were + + align:start position:0% +students had at MIT when they were + + + align:start position:0% +students had at MIT when they were +taking the class in + + align:start position:0% +taking the class in + + + align:start position:0% +taking the class in +person I'm so glad that you've chosen to + + align:start position:0% +person I'm so glad that you've chosen to + + + align:start position:0% +person I'm so glad that you've chosen to +take your time to learn about the + + align:start position:0% +take your time to learn about the + + + align:start position:0% +take your time to learn about the +fascinating world of Music Theory and + + align:start position:0% +fascinating world of Music Theory and + + + align:start position:0% +fascinating world of Music Theory and +music analysis with a computer and I + + align:start position:0% +music analysis with a computer and I + + + align:start position:0% +music analysis with a computer and I +look forward to seeing you again from + + align:start position:0% +look forward to seeing you again from + + + align:start position:0% +look forward to seeing you again from +time to time in this course \ No newline at end of file diff --git a/C42jXQLc_Jo.txt b/C42jXQLc_Jo.txt new file mode 100644 index 0000000000000000000000000000000000000000..9de1c5037e769940d3f1abad9876388734bbf2f5 --- /dev/null +++ b/C42jXQLc_Jo.txt @@ -0,0 +1,15363 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so um module systems and + + align:start position:0% +ocw.mit.edu so um module systems and + + + align:start position:0% +ocw.mit.edu so um module systems and +reliability uh what we're going to do is + + align:start position:0% +reliability uh what we're going to do is + + + align:start position:0% +reliability uh what we're going to do is +talk about how we go from the cells uh + + align:start position:0% +talk about how we go from the cells uh + + + align:start position:0% +talk about how we go from the cells uh +or from the uh films uh to full modules + + align:start position:0% +or from the uh films uh to full modules + + + align:start position:0% +or from the uh films uh to full modules +and finally to systems so our first + + align:start position:0% +and finally to systems so our first + + + align:start position:0% +and finally to systems so our first +learning objective is to describe more + + align:start position:0% +learning objective is to describe more + + + align:start position:0% +learning objective is to describe more +or less the DNA or anatomy of a PV + + align:start position:0% +or less the DNA or anatomy of a PV + + + align:start position:0% +or less the DNA or anatomy of a PV +module uh this will be a bit of a prep + + align:start position:0% +module uh this will be a bit of a prep + + + align:start position:0% +module uh this will be a bit of a prep +for the visit to fronhofer CSE where + + align:start position:0% +for the visit to fronhofer CSE where + + + align:start position:0% +for the visit to fronhofer CSE where +we'll get to see uh the labs and see all + + align:start position:0% +we'll get to see uh the labs and see all + + + align:start position:0% +we'll get to see uh the labs and see all +the materials that go into a PV module + + align:start position:0% +the materials that go into a PV module + + + align:start position:0% +the materials that go into a PV module +so just establishing some definitions up + + align:start position:0% +so just establishing some definitions up + + + align:start position:0% +so just establishing some definitions up +front so we're all speaking the same + + align:start position:0% +front so we're all speaking the same + + + align:start position:0% +front so we're all speaking the same +language um you start out with either a + + align:start position:0% +language um you start out with either a + + + align:start position:0% +language um you start out with either a +film right if you're depositing a thin + + align:start position:0% +film right if you're depositing a thin + + + align:start position:0% +film right if you're depositing a thin +film material uh which is uh usually div + + align:start position:0% +film material uh which is uh usually div + + + align:start position:0% +film material uh which is uh usually div +into discret devices using laser + + align:start position:0% +into discret devices using laser + + + align:start position:0% +into discret devices using laser +processing um or you can start out with + + align:start position:0% +processing um or you can start out with + + + align:start position:0% +processing um or you can start out with +a discrete wafer which has been + + align:start position:0% +a discrete wafer which has been + + + align:start position:0% +a discrete wafer which has been +processed into a cell the module is the + + align:start position:0% +processed into a cell the module is the + + + align:start position:0% +processed into a cell the module is the +combination of many of these cells uh + + align:start position:0% +combination of many of these cells uh + + + align:start position:0% +combination of many of these cells uh +shown very generically right here + + align:start position:0% +shown very generically right here + + + align:start position:0% +shown very generically right here +without the interconnects because you + + align:start position:0% +without the interconnects because you + + + align:start position:0% +without the interconnects because you +can uh tie up the cells together in + + align:start position:0% +can uh tie up the cells together in + + + align:start position:0% +can uh tie up the cells together in +parallel or in series depending on uh on + + align:start position:0% +parallel or in series depending on uh on + + + align:start position:0% +parallel or in series depending on uh on +on on what sort of voltage and current + + align:start position:0% +on on what sort of voltage and current + + + align:start position:0% +on on what sort of voltage and current +outputs you desire from your module and + + align:start position:0% +outputs you desire from your module and + + + align:start position:0% +outputs you desire from your module and +then finally the modules are situated + + align:start position:0% +then finally the modules are situated + + + align:start position:0% +then finally the modules are situated +together in an array uh that showing a + + align:start position:0% +together in an array uh that showing a + + + align:start position:0% +together in an array uh that showing a +combination of six modules forming that + + align:start position:0% +combination of six modules forming that + + + align:start position:0% +combination of six modules forming that +array array right there and as you can + + align:start position:0% +array array right there and as you can + + + align:start position:0% +array array right there and as you can +see modules are typically this size + + align:start position:0% +see modules are typically this size + + + align:start position:0% +see modules are typically this size +right here right they're U usually about + + align:start position:0% +right here right they're U usually about + + + align:start position:0% +right here right they're U usually about +this size or even a little larger um + + align:start position:0% +this size or even a little larger um + + + align:start position:0% +this size or even a little larger um +they're rather heavy so you get a sense + + align:start position:0% +they're rather heavy so you get a sense + + + align:start position:0% +they're rather heavy so you get a sense +it's uh they're not extremely light + + align:start position:0% +it's uh they're not extremely light + + + align:start position:0% +it's uh they're not extremely light +majority of that mass is coming from the + + align:start position:0% +majority of that mass is coming from the + + + align:start position:0% +majority of that mass is coming from the +glass in the front some from the + + align:start position:0% +glass in the front some from the + + + align:start position:0% +glass in the front some from the +aluminum as well and they're comprised + + align:start position:0% +aluminum as well and they're comprised + + + align:start position:0% +aluminum as well and they're comprised +of many materials if you uh were to take + + align:start position:0% +of many materials if you uh were to take + + + align:start position:0% +of many materials if you uh were to take +this apart which will actually see the + + align:start position:0% +this apart which will actually see the + + + align:start position:0% +this apart which will actually see the +individual components that front up for + + align:start position:0% +individual components that front up for + + + align:start position:0% +individual components that front up for +CSE you notice that there are many + + align:start position:0% +CSE you notice that there are many + + + align:start position:0% +CSE you notice that there are many +materials involved in making one of + + align:start position:0% +materials involved in making one of + + + align:start position:0% +materials involved in making one of +these modules uh from the back skinin + + align:start position:0% +these modules uh from the back skinin + + + align:start position:0% +these modules uh from the back skinin +materials the junction box the aluminum + + align:start position:0% +materials the junction box the aluminum + + + align:start position:0% +materials the junction box the aluminum +framing on the side the glass in the + + align:start position:0% +framing on the side the glass in the + + + align:start position:0% +framing on the side the glass in the +front uh the encapsulate materials that + + align:start position:0% +front uh the encapsulate materials that + + + align:start position:0% +front uh the encapsulate materials that +fuse everything together that bind + + align:start position:0% +fuse everything together that bind + + + align:start position:0% +fuse everything together that bind +everything and the cells uh the solar + + align:start position:0% +everything and the cells uh the solar + + + align:start position:0% +everything and the cells uh the solar +cell devices themselves so our first + + align:start position:0% +cell devices themselves so our first + + + align:start position:0% +cell devices themselves so our first +step is to walk through the anatomy of a + + align:start position:0% +step is to walk through the anatomy of a + + + align:start position:0% +step is to walk through the anatomy of a +module at least in theory so that when + + align:start position:0% +module at least in theory so that when + + + align:start position:0% +module at least in theory so that when +we actually see it at frer CSE we'll + + align:start position:0% +we actually see it at frer CSE we'll + + + align:start position:0% +we actually see it at frer CSE we'll +have a better sense of what we're + + align:start position:0% +have a better sense of what we're + + + align:start position:0% +have a better sense of what we're +looking at yep Ashley here's what + + align:start position:0% +looking at yep Ashley here's what + + + align:start position:0% +looking at yep Ashley here's what +determines the that specific size we've + + align:start position:0% +determines the that specific size we've + + + align:start position:0% +determines the that specific size we've +already talked about you know the pseudo + + align:start position:0% +already talked about you know the pseudo + + + align:start position:0% +already talked about you know the pseudo +square and how you have to balance those + + align:start position:0% +square and how you have to balance those + + + align:start position:0% +square and how you have to balance those +the two different cost parameters but + + align:start position:0% +the two different cost parameters but + + + align:start position:0% +the two different cost parameters but +why that size specifically like why that + + align:start position:0% +why that size specifically like why that + + + align:start position:0% +why that size specifically like why that +size specifically we're going to get to + + align:start position:0% +size specifically we're going to get to + + + align:start position:0% +size specifically we're going to get to +that in a few slides um it comes as you + + align:start position:0% +that in a few slides um it comes as you + + + align:start position:0% +that in a few slides um it comes as you +probably guess from some historical + + align:start position:0% +probably guess from some historical + + + align:start position:0% +probably guess from some historical +reasons okay um so some of some basic uh + + align:start position:0% +reasons okay um so some of some basic uh + + + align:start position:0% +reasons okay um so some of some basic uh +principles about solar modules there's + + align:start position:0% +principles about solar modules there's + + + align:start position:0% +principles about solar modules there's +there's quite a diversity of modules + + align:start position:0% +there's quite a diversity of modules + + + align:start position:0% +there's quite a diversity of modules +when you look at them uh these are + + align:start position:0% +when you look at them uh these are + + + align:start position:0% +when you look at them uh these are +examples just within one company uh just + + align:start position:0% +examples just within one company uh just + + + align:start position:0% +examples just within one company uh just +to to to highlight uh what you the range + + align:start position:0% +to to to highlight uh what you the range + + + align:start position:0% +to to to highlight uh what you the range +of module types that you might see + + align:start position:0% +of module types that you might see + + + align:start position:0% +of module types that you might see +right here you can see in this + + align:start position:0% +right here you can see in this + + + align:start position:0% +right here you can see in this +particular module uh there's very little + + align:start position:0% +particular module uh there's very little + + + align:start position:0% +particular module uh there's very little +anti-reflective coating on the glass so + + align:start position:0% +anti-reflective coating on the glass so + + + align:start position:0% +anti-reflective coating on the glass so +you're able to look through the front + + align:start position:0% +you're able to look through the front + + + align:start position:0% +you're able to look through the front +glass and see some white spaces in + + align:start position:0% +glass and see some white spaces in + + + align:start position:0% +glass and see some white spaces in +between the cells we know from the + + align:start position:0% +between the cells we know from the + + + align:start position:0% +between the cells we know from the +lecture on Crystal and silicon PV that + + align:start position:0% +lecture on Crystal and silicon PV that + + + align:start position:0% +lecture on Crystal and silicon PV that +when you see these little gaps in + + align:start position:0% +when you see these little gaps in + + + align:start position:0% +when you see these little gaps in +between the cells those are pseudo + + align:start position:0% +between the cells those are pseudo + + + align:start position:0% +between the cells those are pseudo +squares right those are those round uh + + align:start position:0% +squares right those are those round uh + + + align:start position:0% +squares right those are those round uh +ingots of Shuki silicon that have been + + align:start position:0% +ingots of Shuki silicon that have been + + + align:start position:0% +ingots of Shuki silicon that have been +sliced into Wafers and then the edges + + align:start position:0% +sliced into Wafers and then the edges + + + align:start position:0% +sliced into Wafers and then the edges +have been shaven off and you have that + + align:start position:0% +have been shaven off and you have that + + + align:start position:0% +have been shaven off and you have that +stop sign type pattern of a solar cell + + align:start position:0% +stop sign type pattern of a solar cell + + + align:start position:0% +stop sign type pattern of a solar cell +right um so that that way you know okay + + align:start position:0% +right um so that that way you know okay + + + align:start position:0% +right um so that that way you know okay +these are single Crystal and cells right + + align:start position:0% +these are single Crystal and cells right + + + align:start position:0% +these are single Crystal and cells right +lined up in a module together and + + align:start position:0% +lined up in a module together and + + + align:start position:0% +lined up in a module together and +there's very little anti-reflective + + align:start position:0% +there's very little anti-reflective + + + align:start position:0% +there's very little anti-reflective +coating on the glass which means that + + align:start position:0% +coating on the glass which means that + + + align:start position:0% +coating on the glass which means that +you're losing a fair amount due to + + align:start position:0% +you're losing a fair amount due to + + + align:start position:0% +you're losing a fair amount due to +reflectance the module on the right hand + + align:start position:0% +reflectance the module on the right hand + + + align:start position:0% +reflectance the module on the right hand +side right here has uh that uh the ENT + + align:start position:0% +side right here has uh that uh the ENT + + + align:start position:0% +side right here has uh that uh the ENT +reflection coating on the glass it could + + align:start position:0% +reflection coating on the glass it could + + + align:start position:0% +reflection coating on the glass it could +be uh an index of refraction uh gradient + + align:start position:0% +be uh an index of refraction uh gradient + + + align:start position:0% +be uh an index of refraction uh gradient +gradient to absorb more of the light it + + align:start position:0% +gradient to absorb more of the light it + + + align:start position:0% +gradient to absorb more of the light it +could also be uh surface texturing to + + align:start position:0% +could also be uh surface texturing to + + + align:start position:0% +could also be uh surface texturing to +scatter the light and trap it by total + + align:start position:0% +scatter the light and trap it by total + + + align:start position:0% +scatter the light and trap it by total +internal reflection once it gets inside + + align:start position:0% +internal reflection once it gets inside + + + align:start position:0% +internal reflection once it gets inside +um there's a few different ways uh that + + align:start position:0% +um there's a few different ways uh that + + + align:start position:0% +um there's a few different ways uh that +that one can do that usually the film + + align:start position:0% +that one can do that usually the film + + + align:start position:0% +that one can do that usually the film +coding is is the most common and uh here + + align:start position:0% +coding is is the most common and uh here + + + align:start position:0% +coding is is the most common and uh here +on the on the left hand side we have a + + align:start position:0% +on the on the left hand side we have a + + + align:start position:0% +on the on the left hand side we have a +similar uh subcell component but much + + align:start position:0% +similar uh subcell component but much + + + align:start position:0% +similar uh subcell component but much +larger module comprised of a larger + + align:start position:0% +larger module comprised of a larger + + + align:start position:0% +larger module comprised of a larger +number of cells with a a higher power + + align:start position:0% +number of cells with a a higher power + + + align:start position:0% +number of cells with a a higher power +output and uh we can see quite a wide + + align:start position:0% +output and uh we can see quite a wide + + + align:start position:0% +output and uh we can see quite a wide +variance of of different types of + + align:start position:0% +variance of of different types of + + + align:start position:0% +variance of of different types of +modules that'll be an important message + + align:start position:0% +modules that'll be an important message + + + align:start position:0% +modules that'll be an important message +in a few um the Water Rinse Cycle really + + align:start position:0% +in a few um the Water Rinse Cycle really + + + align:start position:0% +in a few um the Water Rinse Cycle really +depends on where you're at like for the + + align:start position:0% +depends on where you're at like for the + + + align:start position:0% +depends on where you're at like for the +module on my roof we just leave them up + + align:start position:0% +module on my roof we just leave them up + + + align:start position:0% +module on my roof we just leave them up +here in New England it's it's pretty + + align:start position:0% +here in New England it's it's pretty + + + align:start position:0% +here in New England it's it's pretty +much okay uh if we did have trees that + + align:start position:0% +much okay uh if we did have trees that + + + align:start position:0% +much okay uh if we did have trees that +deposited leaves nearby we'd have to + + align:start position:0% +deposited leaves nearby we'd have to + + + align:start position:0% +deposited leaves nearby we'd have to +clean it off uh in the fall uh but we + + align:start position:0% +clean it off uh in the fall uh but we + + + align:start position:0% +clean it off uh in the fall uh but we +don't uh if you're mounting modules in + + align:start position:0% +don't uh if you're mounting modules in + + + align:start position:0% +don't uh if you're mounting modules in +the Middle East where that fine grain + + align:start position:0% +the Middle East where that fine grain + + + align:start position:0% +the Middle East where that fine grain +sand exists and the if you're within 10 + + align:start position:0% +sand exists and the if you're within 10 + + + align:start position:0% +sand exists and the if you're within 10 +kilometers from the coast where you have + + align:start position:0% +kilometers from the coast where you have + + + align:start position:0% +kilometers from the coast where you have +the salt and the sea water in the air uh + + align:start position:0% +the salt and the sea water in the air uh + + + align:start position:0% +the salt and the sea water in the air uh +you can get this uh really hard to + + align:start position:0% +you can get this uh really hard to + + + align:start position:0% +you can get this uh really hard to +remove uh sand caking the modules and + + align:start position:0% +remove uh sand caking the modules and + + + align:start position:0% +remove uh sand caking the modules and +you would have to clean them much more + + align:start position:0% +you would have to clean them much more + + + align:start position:0% +you would have to clean them much more +frequently uh than this as matter of + + align:start position:0% +frequently uh than this as matter of + + + align:start position:0% +frequently uh than this as matter of +fact I believe the numbers are in Abu + + align:start position:0% +fact I believe the numbers are in Abu + + + align:start position:0% +fact I believe the numbers are in Abu +Dhabi right outside of um one of the uh + + align:start position:0% +Dhabi right outside of um one of the uh + + + align:start position:0% +Dhabi right outside of um one of the uh +one the capital of one of the Emirates + + align:start position:0% +one the capital of one of the Emirates + + + align:start position:0% +one the capital of one of the Emirates +in in uh the UAE uh if you were to just + + align:start position:0% +in in uh the UAE uh if you were to just + + + align:start position:0% +in in uh the UAE uh if you were to just +leave your modules out near the ocean uh + + align:start position:0% +leave your modules out near the ocean uh + + + align:start position:0% +leave your modules out near the ocean uh +near the desert you would have a 40% + + align:start position:0% +near the desert you would have a 40% + + + align:start position:0% +near the desert you would have a 40% +drop in module output over a + + align:start position:0% +drop in module output over a + + + align:start position:0% +drop in module output over a +month right so that's what happens in + + align:start position:0% +month right so that's what happens in + + + align:start position:0% +month right so that's what happens in +certain environments uh in certain + + align:start position:0% +certain environments uh in certain + + + align:start position:0% +certain environments uh in certain +others like uh New England were more uh + + align:start position:0% +others like uh New England were more uh + + + align:start position:0% +others like uh New England were more uh +I say more buffered in that regard we + + align:start position:0% +I say more buffered in that regard we + + + align:start position:0% +I say more buffered in that regard we +have have frequent rain and we don't + + align:start position:0% +have have frequent rain and we don't + + + align:start position:0% +have have frequent rain and we don't +have the the dust coming from any nearby + + align:start position:0% +have the the dust coming from any nearby + + + align:start position:0% +have the the dust coming from any nearby +desert um typically there are no moving + + align:start position:0% +desert um typically there are no moving + + + align:start position:0% +desert um typically there are no moving +parts and typically there's a 20 to 30y + + align:start position:0% +parts and typically there's a 20 to 30y + + + align:start position:0% +parts and typically there's a 20 to 30y +year manufacturer warranty some of the + + align:start position:0% +year manufacturer warranty some of the + + + align:start position:0% +year manufacturer warranty some of the +newer materials that have been less + + align:start position:0% +newer materials that have been less + + + align:start position:0% +newer materials that have been less +tested might give say a 10-year + + align:start position:0% +tested might give say a 10-year + + + align:start position:0% +tested might give say a 10-year +manufacturers warranty and have to + + align:start position:0% +manufacturers warranty and have to + + + align:start position:0% +manufacturers warranty and have to +offset uh the risk in years 10 to 20 by + + align:start position:0% +offset uh the risk in years 10 to 20 by + + + align:start position:0% +offset uh the risk in years 10 to 20 by +um by uh uh lowering the cost up front + + align:start position:0% +um by uh uh lowering the cost up front + + + align:start position:0% +um by uh uh lowering the cost up front +or lowering the price up front so we + + align:start position:0% +or lowering the price up front so we + + + align:start position:0% +or lowering the price up front so we +have uh some Basics about solar modules + + align:start position:0% +have uh some Basics about solar modules + + + align:start position:0% +have uh some Basics about solar modules +uh just to to situate ourselves let's + + align:start position:0% +uh just to to situate ourselves let's + + + align:start position:0% +uh just to to situate ourselves let's +dive into the module d since this is uh + + align:start position:0% +dive into the module d since this is uh + + + align:start position:0% +dive into the module d since this is uh +where where the rubber hits the road um + + align:start position:0% +where where the rubber hits the road um + + + align:start position:0% +where where the rubber hits the road um +I'm going to show this to you in theory + + align:start position:0% +I'm going to show this to you in theory + + + align:start position:0% +I'm going to show this to you in theory +and then we're going to see uh roles + + align:start position:0% +and then we're going to see uh roles + + + align:start position:0% +and then we're going to see uh roles +reams of these uh module iner materials + + align:start position:0% +reams of these uh module iner materials + + + align:start position:0% +reams of these uh module iner materials +when we visit fraer so uh we start with + + align:start position:0% +when we visit fraer so uh we start with + + + align:start position:0% +when we visit fraer so uh we start with +the solar cells themselves these are + + align:start position:0% +the solar cells themselves these are + + + align:start position:0% +the solar cells themselves these are +these little blue uh objects right there + + align:start position:0% +these little blue uh objects right there + + + align:start position:0% +these little blue uh objects right there +um typically these cells are already + + align:start position:0% +um typically these cells are already + + + align:start position:0% +um typically these cells are already +strung together at that point they have + + align:start position:0% +strung together at that point they have + + + align:start position:0% +strung together at that point they have +contact metalization uh on on the front + + align:start position:0% +contact metalization uh on on the front + + + align:start position:0% +contact metalization uh on on the front +side which we deposit say for example by + + align:start position:0% +side which we deposit say for example by + + + align:start position:0% +side which we deposit say for example by +screen printing which you've done in the + + align:start position:0% +screen printing which you've done in the + + + align:start position:0% +screen printing which you've done in the +lab downstairs and then you string them + + align:start position:0% +lab downstairs and then you string them + + + align:start position:0% +lab downstairs and then you string them +together using a machine called a tabber + + align:start position:0% +together using a machine called a tabber + + + align:start position:0% +together using a machine called a tabber +Stringer to connect one cell to the next + + align:start position:0% +Stringer to connect one cell to the next + + + align:start position:0% +Stringer to connect one cell to the next +essentially the front of one cell to the + + align:start position:0% +essentially the front of one cell to the + + + align:start position:0% +essentially the front of one cell to the +back of the next and they're all lined + + align:start position:0% +back of the next and they're all lined + + + align:start position:0% +back of the next and they're all lined +up like that and you deposit layers of + + align:start position:0% +up like that and you deposit layers of + + + align:start position:0% +up like that and you deposit layers of +Eva which is um ethyl vinyl acetate uh + + align:start position:0% +Eva which is um ethyl vinyl acetate uh + + + align:start position:0% +Eva which is um ethyl vinyl acetate uh +this is typically the encapsulate + + align:start position:0% +this is typically the encapsulate + + + align:start position:0% +this is typically the encapsulate +material used it's shown in red right + + align:start position:0% +material used it's shown in red right + + + align:start position:0% +material used it's shown in red right +here in this drawing it's the + + align:start position:0% +here in this drawing it's the + + + align:start position:0% +here in this drawing it's the +encapsulate material used uh for uh + + align:start position:0% +encapsulate material used uh for uh + + + align:start position:0% +encapsulate material used uh for uh +Crystal and silicon PV on the back side + + align:start position:0% +Crystal and silicon PV on the back side + + + align:start position:0% +Crystal and silicon PV on the back side +there's a a sheet of material called + + align:start position:0% +there's a a sheet of material called + + + align:start position:0% +there's a a sheet of material called +tedlar despite it being drawn in yellow + + align:start position:0% +tedlar despite it being drawn in yellow + + + align:start position:0% +tedlar despite it being drawn in yellow +right there it's the white skin material + + align:start position:0% +right there it's the white skin material + + + align:start position:0% +right there it's the white skin material +here it's this white + + align:start position:0% +here it's this white + + + align:start position:0% +here it's this white +material right around + + align:start position:0% +material right around + + + align:start position:0% +material right around +here and we have the glass in the front + + align:start position:0% +here and we have the glass in the front + + + align:start position:0% +here and we have the glass in the front +side and typically it's low iron glass + + align:start position:0% +side and typically it's low iron glass + + + align:start position:0% +side and typically it's low iron glass +so it can transmit the ultraviolet light + + align:start position:0% +so it can transmit the ultraviolet light + + + align:start position:0% +so it can transmit the ultraviolet light +uh or a large portion of it um to give + + align:start position:0% +uh or a large portion of it um to give + + + align:start position:0% +uh or a large portion of it um to give +better blue response to your solar cells + + align:start position:0% +better blue response to your solar cells + + + align:start position:0% +better blue response to your solar cells +so you're capturing a larger portion of + + align:start position:0% +so you're capturing a larger portion of + + + align:start position:0% +so you're capturing a larger portion of +the solar + + align:start position:0% +the solar + + + align:start position:0% +the solar +Spectrum okay so we have uh the + + align:start position:0% +Spectrum okay so we have uh the + + + align:start position:0% +Spectrum okay so we have uh the +different components right there um one + + align:start position:0% +different components right there um one + + + align:start position:0% +different components right there um one +little piece of trivia about Eva uh for + + align:start position:0% +little piece of trivia about Eva uh for + + + align:start position:0% +little piece of trivia about Eva uh for +the chemist in the room uh what do you + + align:start position:0% +the chemist in the room uh what do you + + + align:start position:0% +the chemist in the room uh what do you +think this would decompose into um let + + align:start position:0% +think this would decompose into um let + + + align:start position:0% +think this would decompose into um let +me uh just uh give you a little hand + + align:start position:0% +me uh just uh give you a little hand + + + align:start position:0% +me uh just uh give you a little hand +here if you had + + align:start position:0% +here if you had + + + align:start position:0% +here if you had +some uh let's + + align:start position:0% +some uh let's + + + align:start position:0% +some uh let's +see + + align:start position:0% +see + + + align:start position:0% +see +um right so these represent uh methyl + + align:start position:0% +um right so these represent uh methyl + + + align:start position:0% +um right so these represent uh methyl +groups hydrogens uh carbon carbon carbon + + align:start position:0% +groups hydrogens uh carbon carbon carbon + + + align:start position:0% +groups hydrogens uh carbon carbon carbon +double bonded to an oxygen anybody + + align:start position:0% +double bonded to an oxygen anybody + + + align:start position:0% +double bonded to an oxygen anybody +recognize yeah yeah so um if you're if + + align:start position:0% +recognize yeah yeah so um if you're if + + + align:start position:0% +recognize yeah yeah so um if you're if +you're looking at the decomposition of + + align:start position:0% +you're looking at the decomposition of + + + align:start position:0% +you're looking at the decomposition of +this uh little uh group right here you + + align:start position:0% +this uh little uh group right here you + + + align:start position:0% +this uh little uh group right here you +could easily Envision it decomposing + + align:start position:0% +could easily Envision it decomposing + + + align:start position:0% +could easily Envision it decomposing +into acetic acid uh from the name + + align:start position:0% +into acetic acid uh from the name + + + align:start position:0% +into acetic acid uh from the name +ethinyl acetate right so uh if you have + + align:start position:0% +ethinyl acetate right so uh if you have + + + align:start position:0% +ethinyl acetate right so uh if you have +um a thin fill material that could react + + align:start position:0% +um a thin fill material that could react + + + align:start position:0% +um a thin fill material that could react +with the encapsulant you could decompose + + align:start position:0% +with the encapsulant you could decompose + + + align:start position:0% +with the encapsulant you could decompose +your encapsulant and cause a degradation + + align:start position:0% +your encapsulant and cause a degradation + + + align:start position:0% +your encapsulant and cause a degradation +um of of not only the the encapsulant + + align:start position:0% +um of of not only the the encapsulant + + + align:start position:0% +um of of not only the the encapsulant +itself which would block some of the + + align:start position:0% +itself which would block some of the + + + align:start position:0% +itself which would block some of the +light going through but of the solar + + align:start position:0% +light going through but of the solar + + + align:start position:0% +light going through but of the solar +cell absorber material too um so that's + + align:start position:0% +cell absorber material too um so that's + + + align:start position:0% +cell absorber material too um so that's +why in many thin fil materials uh there + + align:start position:0% +why in many thin fil materials uh there + + + align:start position:0% +why in many thin fil materials uh there +are other encapsulants used like PVB + + align:start position:0% +are other encapsulants used like PVB + + + align:start position:0% +are other encapsulants used like PVB +right polyvinyl butol and some folks are + + align:start position:0% +right polyvinyl butol and some folks are + + + align:start position:0% +right polyvinyl butol and some folks are +even talking about getting away from + + align:start position:0% +even talking about getting away from + + + align:start position:0% +even talking about getting away from +glass and Eva all together and just + + align:start position:0% +glass and Eva all together and just + + + align:start position:0% +glass and Eva all together and just +putting down um I say an organic uh + + align:start position:0% +putting down um I say an organic uh + + + align:start position:0% +putting down um I say an organic uh +resin type material maybe a very hard um + + align:start position:0% +resin type material maybe a very hard um + + + align:start position:0% +resin type material maybe a very hard um +uh polymeric material that could be used + + align:start position:0% +uh polymeric material that could be used + + + align:start position:0% +uh polymeric material that could be used +in a floor in a clean room let's say + + align:start position:0% +in a floor in a clean room let's say + + + align:start position:0% +in a floor in a clean room let's say +yeah is the low iron content of the + + align:start position:0% +yeah is the low iron content of the + + + align:start position:0% +yeah is the low iron content of the +glass also important to prevent + + align:start position:0% +glass also important to prevent + + + align:start position:0% +glass also important to prevent +impurities getting into the we pass that + + align:start position:0% +impurities getting into the we pass that + + + align:start position:0% +impurities getting into the we pass that +so uh the question was is a low iron + + align:start position:0% +so uh the question was is a low iron + + + align:start position:0% +so uh the question was is a low iron +content in the glass also useful for + + align:start position:0% +content in the glass also useful for + + + align:start position:0% +content in the glass also useful for +preventing impurities from getting in um + + align:start position:0% +preventing impurities from getting in um + + + align:start position:0% +preventing impurities from getting in um +I would say if you're + + align:start position:0% +I would say if you're + + + align:start position:0% +I would say if you're +producing see the the diffusivity and + + align:start position:0% +producing see the the diffusivity and + + + align:start position:0% +producing see the the diffusivity and +solubility of impurities in a solid + + align:start position:0% +solubility of impurities in a solid + + + align:start position:0% +solubility of impurities in a solid +typically follow boltzman statistics + + align:start position:0% +typically follow boltzman statistics + + + align:start position:0% +typically follow boltzman statistics +meaning they increase exponentially with + + align:start position:0% +meaning they increase exponentially with + + + align:start position:0% +meaning they increase exponentially with +temperature it's it's an entropy driven + + align:start position:0% +temperature it's it's an entropy driven + + + align:start position:0% +temperature it's it's an entropy driven +effect and uh as a result of being at + + align:start position:0% +effect and uh as a result of being at + + + align:start position:0% +effect and uh as a result of being at +room temperature the transmission or the + + align:start position:0% +room temperature the transmission or the + + + align:start position:0% +room temperature the transmission or the +diffusivity and hence the solubility of + + align:start position:0% +diffusivity and hence the solubility of + + + align:start position:0% +diffusivity and hence the solubility of +iron inside of the bulk silicon is very + + align:start position:0% +iron inside of the bulk silicon is very + + + align:start position:0% +iron inside of the bulk silicon is very +low um and even over 20year span uh the + + align:start position:0% +low um and even over 20year span uh the + + + align:start position:0% +low um and even over 20year span uh the +total diffusion length of the iron from + + align:start position:0% +total diffusion length of the iron from + + + align:start position:0% +total diffusion length of the iron from +the glass into the Silicon would be + + align:start position:0% +the glass into the Silicon would be + + + align:start position:0% +the glass into the Silicon would be +rather small now point taken if you were + + align:start position:0% +rather small now point taken if you were + + + align:start position:0% +rather small now point taken if you were +to say create a quartz tube to do your + + align:start position:0% +to say create a quartz tube to do your + + + align:start position:0% +to say create a quartz tube to do your +phosphorous diffusion at 800 degre C or + + align:start position:0% +phosphorous diffusion at 800 degre C or + + + align:start position:0% +phosphorous diffusion at 800 degre C or +850° C um and you had iron inside of + + align:start position:0% +850° C um and you had iron inside of + + + align:start position:0% +850° C um and you had iron inside of +that quartz tube then it could very + + align:start position:0% +that quartz tube then it could very + + + align:start position:0% +that quartz tube then it could very +easily diffuse into your wafer so it is + + align:start position:0% +easily diffuse into your wafer so it is + + + align:start position:0% +easily diffuse into your wafer so it is +important to to be considerate of of + + align:start position:0% +important to to be considerate of of + + + align:start position:0% +important to to be considerate of of +impurities and the effects thereof but + + align:start position:0% +impurities and the effects thereof but + + + align:start position:0% +impurities and the effects thereof but +uh at low temperatures close to room + + align:start position:0% +uh at low temperatures close to room + + + align:start position:0% +uh at low temperatures close to room +temperature there's very little risk of + + align:start position:0% +temperature there's very little risk of + + + align:start position:0% +temperature there's very little risk of +it moving around good so um tedlar this + + align:start position:0% +it moving around good so um tedlar this + + + align:start position:0% +it moving around good so um tedlar this +back skin material right here forms uh + + align:start position:0% +back skin material right here forms uh + + + align:start position:0% +back skin material right here forms uh +an almost impenetrable back layer you + + align:start position:0% +an almost impenetrable back layer you + + + align:start position:0% +an almost impenetrable back layer you +might want to put little asteris around + + align:start position:0% +might want to put little asteris around + + + align:start position:0% +might want to put little asteris around +uh sorry a little uh quotes around + + align:start position:0% +uh sorry a little uh quotes around + + + align:start position:0% +uh sorry a little uh quotes around +impenetrable nothing is absolutely + + align:start position:0% +impenetrable nothing is absolutely + + + align:start position:0% +impenetrable nothing is absolutely +impenetrable but uh there is it is a + + align:start position:0% +impenetrable but uh there is it is a + + + align:start position:0% +impenetrable but uh there is it is a +very tough tough material if you were to + + align:start position:0% +very tough tough material if you were to + + + align:start position:0% +very tough tough material if you were to +take a piece of tedlar and try to break + + align:start position:0% +take a piece of tedlar and try to break + + + align:start position:0% +take a piece of tedlar and try to break +it try to rip it or tear it um even the + + align:start position:0% +it try to rip it or tear it um even the + + + align:start position:0% +it try to rip it or tear it um even the +strongest in the class would be + + align:start position:0% +strongest in the class would be + + + align:start position:0% +strongest in the class would be +challenged in that regard uh and we'll + + align:start position:0% +challenged in that regard uh and we'll + + + align:start position:0% +challenged in that regard uh and we'll +have a chance to do that at frown hoofer + + align:start position:0% +have a chance to do that at frown hoofer + + + align:start position:0% +have a chance to do that at frown hoofer +um the aluminum frame provides rigidity + + align:start position:0% +um the aluminum frame provides rigidity + + + align:start position:0% +um the aluminum frame provides rigidity +right so the mechanical engineers in the + + align:start position:0% +right so the mechanical engineers in the + + + align:start position:0% +right so the mechanical engineers in the +room um would understand that the + + align:start position:0% +room um would understand that the + + + align:start position:0% +room um would understand that the +bending mode of this glass right or the + + align:start position:0% +bending mode of this glass right or the + + + align:start position:0% +bending mode of this glass right or the +twist um is prevented by these uh rigid + + align:start position:0% +twist um is prevented by these uh rigid + + + align:start position:0% +twist um is prevented by these uh rigid +aluminum uh extruded aluminum components + + align:start position:0% +aluminum uh extruded aluminum components + + + align:start position:0% +aluminum uh extruded aluminum components +right here in the back right and you can + + align:start position:0% +right here in the back right and you can + + + align:start position:0% +right here in the back right and you can +see that a lot of the mass is + + align:start position:0% +see that a lot of the mass is + + + align:start position:0% +see that a lot of the mass is +concentrated away from uh this the the + + align:start position:0% +concentrated away from uh this the the + + + align:start position:0% +concentrated away from uh this the the +the the centroid right uh which results + + align:start position:0% +the the centroid right uh which results + + + align:start position:0% +the the centroid right uh which results +in a larger stiffness prevention of of + + align:start position:0% +in a larger stiffness prevention of of + + + align:start position:0% +in a larger stiffness prevention of of +bending larger bending moment second + + align:start position:0% +bending larger bending moment second + + + align:start position:0% +bending larger bending moment second +moment if you will okay so there's a + + align:start position:0% +moment if you will okay so there's a + + + align:start position:0% +moment if you will okay so there's a +fair amount of mechanical engineering + + align:start position:0% +fair amount of mechanical engineering + + + align:start position:0% +fair amount of mechanical engineering +that goes into the design uh because you + + align:start position:0% +that goes into the design uh because you + + + align:start position:0% +that goes into the design uh because you +want to minimize commodity material + + align:start position:0% +want to minimize commodity material + + + align:start position:0% +want to minimize commodity material +costs you want to minimize the amount of + + align:start position:0% +costs you want to minimize the amount of + + + align:start position:0% +costs you want to minimize the amount of +materials that go into the module but + + align:start position:0% +materials that go into the module but + + + align:start position:0% +materials that go into the module but +you still want it to last for 20 years + + align:start position:0% +you still want it to last for 20 years + + + align:start position:0% +you still want it to last for 20 years +you still want it to be resistant to + + align:start position:0% +you still want it to be resistant to + + + align:start position:0% +you still want it to be resistant to +snow loads to wind loads you don't want + + align:start position:0% +snow loads to wind loads you don't want + + + align:start position:0% +snow loads to wind loads you don't want +to break and you don't want to make good + + align:start position:0% +to break and you don't want to make good + + + align:start position:0% +to break and you don't want to make good +on your 20-year warranty that costs you + + align:start position:0% +on your 20-year warranty that costs you + + + align:start position:0% +on your 20-year warranty that costs you +money as + + align:start position:0% +money as + + + align:start position:0% +money as +manufacturer so the circuit design in + + align:start position:0% +manufacturer so the circuit design in + + + align:start position:0% +manufacturer so the circuit design in +most modules follows something very + + align:start position:0% +most modules follows something very + + + align:start position:0% +most modules follows something very +similar to this now what you see when + + align:start position:0% +similar to this now what you see when + + + align:start position:0% +similar to this now what you see when +you glance at this what what you should + + align:start position:0% +you glance at this what what you should + + + align:start position:0% +you glance at this what what you should +be looking is you here are the context + + align:start position:0% +be looking is you here are the context + + + align:start position:0% +be looking is you here are the context +those those are the leads coming out of + + align:start position:0% +those those are the leads coming out of + + + align:start position:0% +those those are the leads coming out of +the module they're essentially these uh + + align:start position:0% +the module they're essentially these uh + + + align:start position:0% +the module they're essentially these uh +leads coming out in the back in the + + align:start position:0% +leads coming out in the back in the + + + align:start position:0% +leads coming out in the back in the +junction box you want to turn it around + + align:start position:0% +junction box you want to turn it around + + + align:start position:0% +junction box you want to turn it around +again here we go so here are the module + + align:start position:0% +again here we go so here are the module + + + align:start position:0% +again here we go so here are the module +leads coming out and the question is how + + align:start position:0% +leads coming out and the question is how + + + align:start position:0% +leads coming out and the question is how +do I String together the cells inside of + + align:start position:0% +do I String together the cells inside of + + + align:start position:0% +do I String together the cells inside of +my module how do I String together these + + align:start position:0% +my module how do I String together these + + + align:start position:0% +my module how do I String together these +cells right in here to provide the + + align:start position:0% +cells right in here to provide the + + + align:start position:0% +cells right in here to provide the +greatest value to the customer do I + + align:start position:0% +greatest value to the customer do I + + + align:start position:0% +greatest value to the customer do I +connect them all in series and make just + + align:start position:0% +connect them all in series and make just + + + align:start position:0% +connect them all in series and make just +one long snaky uh electronic path do I + + align:start position:0% +one long snaky uh electronic path do I + + + align:start position:0% +one long snaky uh electronic path do I +connect them all in parallel that would + + align:start position:0% +connect them all in parallel that would + + + align:start position:0% +connect them all in parallel that would +require a lot of wiring um or do I some + + align:start position:0% +require a lot of wiring um or do I some + + + align:start position:0% +require a lot of wiring um or do I some +do I do something in between and if you + + align:start position:0% +do I do something in between and if you + + + align:start position:0% +do I do something in between and if you +were to come up close to here and + + align:start position:0% +were to come up close to here and + + + align:start position:0% +were to come up close to here and +inspect it what you would see is that + + align:start position:0% +inspect it what you would see is that + + + align:start position:0% +inspect it what you would see is that +you have uh strings in parallel right so + + align:start position:0% +you have uh strings in parallel right so + + + align:start position:0% +you have uh strings in parallel right so +you have a one going from here down and + + align:start position:0% +you have a one going from here down and + + + align:start position:0% +you have a one going from here down and +around that's one two and three right + + align:start position:0% +around that's one two and three right + + + align:start position:0% +around that's one two and three right +three of these strings and um they're + + align:start position:0% +three of these strings and um they're + + + align:start position:0% +three of these strings and um they're +connected those three strings are + + align:start position:0% +connected those three strings are + + + align:start position:0% +connected those three strings are +connected in parallel and each string is + + align:start position:0% +connected in parallel and each string is + + + align:start position:0% +connected in parallel and each string is +comprised of uh several uh solar cells + + align:start position:0% +comprised of uh several uh solar cells + + + align:start position:0% +comprised of uh several uh solar cells +now for historical reasons the Crystal + + align:start position:0% +now for historical reasons the Crystal + + + align:start position:0% +now for historical reasons the Crystal +and silicon solar cell modules have + + align:start position:0% +and silicon solar cell modules have + + + align:start position:0% +and silicon solar cell modules have +typically had strings of around 36 cells + + align:start position:0% +typically had strings of around 36 cells + + + align:start position:0% +typically had strings of around 36 cells +connected in series um what this does is + + align:start position:0% +connected in series um what this does is + + + align:start position:0% +connected in series um what this does is +it yields a maximum PowerPoint voltage + + align:start position:0% +it yields a maximum PowerPoint voltage + + + align:start position:0% +it yields a maximum PowerPoint voltage +somewhere in the range of 17 to 18 volts + + align:start position:0% +somewhere in the range of 17 to 18 volts + + + align:start position:0% +somewhere in the range of 17 to 18 volts +if you remember the voc's of your solar + + align:start position:0% +if you remember the voc's of your solar + + + align:start position:0% +if you remember the voc's of your solar +cells and the maximum PowerPoint voltage + + align:start position:0% +cells and the maximum PowerPoint voltage + + + align:start position:0% +cells and the maximum PowerPoint voltage +of your solar cells or somewhere around + + align:start position:0% +of your solar cells or somewhere around + + + align:start position:0% +of your solar cells or somewhere around +0.5 um and uh so you take 36 cells + + align:start position:0% +0.5 um and uh so you take 36 cells + + + align:start position:0% +0.5 um and uh so you take 36 cells +divide by two or multiply by 0.5 if you + + align:start position:0% +divide by two or multiply by 0.5 if you + + + align:start position:0% +divide by two or multiply by 0.5 if you +will and you're Landing somewhere in + + align:start position:0% +will and you're Landing somewhere in + + + align:start position:0% +will and you're Landing somewhere in +this + + align:start position:0% +this + + + align:start position:0% +this +Ballpark and what that does is it + + align:start position:0% +Ballpark and what that does is it + + + align:start position:0% +Ballpark and what that does is it +enables you to hit even under lower + + align:start position:0% +enables you to hit even under lower + + + align:start position:0% +enables you to hit even under lower +light conditions the over potential + + align:start position:0% +light conditions the over potential + + + align:start position:0% +light conditions the over potential +needed to charge a a rechargeable + + align:start position:0% +needed to charge a a rechargeable + + + align:start position:0% +needed to charge a a rechargeable +battery so if it a 12vt battery um and + + align:start position:0% +battery so if it a 12vt battery um and + + + align:start position:0% +battery so if it a 12vt battery um and +the voltage output of the battery is + + align:start position:0% +the voltage output of the battery is + + + align:start position:0% +the voltage output of the battery is +between say 12 and kind of dropping down + + align:start position:0% +between say 12 and kind of dropping down + + + align:start position:0% +between say 12 and kind of dropping down +to 10 before it starts using its utility + + align:start position:0% +to 10 before it starts using its utility + + + align:start position:0% +to 10 before it starts using its utility +when you try to start your car and it + + align:start position:0% +when you try to start your car and it + + + align:start position:0% +when you try to start your car and it +just turns it doesn't really turn over + + align:start position:0% +just turns it doesn't really turn over + + + align:start position:0% +just turns it doesn't really turn over +and you can't start your engine it's + + align:start position:0% +and you can't start your engine it's + + + align:start position:0% +and you can't start your engine it's +probably because the voltage in your + + align:start position:0% +probably because the voltage in your + + + align:start position:0% +probably because the voltage in your +battery has dropped to about uh 10 volts + + align:start position:0% +battery has dropped to about uh 10 volts + + + align:start position:0% +battery has dropped to about uh 10 volts +um the over potential needed to charge + + align:start position:0% +um the over potential needed to charge + + + align:start position:0% +um the over potential needed to charge +it 13 plus um that's what you're hitting + + align:start position:0% +it 13 plus um that's what you're hitting + + + align:start position:0% +it 13 plus um that's what you're hitting +with with the string and uh that's for + + align:start position:0% +with with the string and uh that's for + + + align:start position:0% +with with the string and uh that's for +historical reasons why we had this + + align:start position:0% +historical reasons why we had this + + + align:start position:0% +historical reasons why we had this +number of cells connected together um as + + align:start position:0% +number of cells connected together um as + + + align:start position:0% +number of cells connected together um as +grid tide systems become more common + + align:start position:0% +grid tide systems become more common + + + align:start position:0% +grid tide systems become more common +though um this constraint is being + + align:start position:0% +though um this constraint is being + + + align:start position:0% +though um this constraint is being +reduced right we have about over 90% of + + align:start position:0% +reduced right we have about over 90% of + + + align:start position:0% +reduced right we have about over 90% of +all of our solar modules today are + + align:start position:0% +all of our solar modules today are + + + align:start position:0% +all of our solar modules today are +connected to the grid including the ones + + align:start position:0% +connected to the grid including the ones + + + align:start position:0% +connected to the grid including the ones +in my home so when I'm not there and + + align:start position:0% +in my home so when I'm not there and + + + align:start position:0% +in my home so when I'm not there and +it's producing excess electricity it's + + align:start position:0% +it's producing excess electricity it's + + + align:start position:0% +it's producing excess electricity it's +pumping it into the grid and maybe we're + + align:start position:0% +pumping it into the grid and maybe we're + + + align:start position:0% +pumping it into the grid and maybe we're +using some of my electrons here I don't + + align:start position:0% +using some of my electrons here I don't + + + align:start position:0% +using some of my electrons here I don't +know um so as grid tide systems become + + align:start position:0% +know um so as grid tide systems become + + + align:start position:0% +know um so as grid tide systems become +more common um you you care less about + + align:start position:0% +more common um you you care less about + + + align:start position:0% +more common um you you care less about +me the over potential requirements for a + + align:start position:0% +me the over potential requirements for a + + + align:start position:0% +me the over potential requirements for a +battery you care more about matching the + + align:start position:0% +battery you care more about matching the + + + align:start position:0% +battery you care more about matching the +output of your solar module with + + align:start position:0% +output of your solar module with + + + align:start position:0% +output of your solar module with +whatever inverter technology you're + + align:start position:0% +whatever inverter technology you're + + + align:start position:0% +whatever inverter technology you're +using to convert the DC power into AC + + align:start position:0% +using to convert the DC power into AC + + + align:start position:0% +using to convert the DC power into AC +power number two why do they spec the + + align:start position:0% +power number two why do they spec the + + + align:start position:0% +power number two why do they spec the +modules that size you notice that I + + align:start position:0% +modules that size you notice that I + + + align:start position:0% +modules that size you notice that I +could lift it just barely I'm a + + align:start position:0% +could lift it just barely I'm a + + + align:start position:0% +could lift it just barely I'm a +university Professor I sit in my chair + + align:start position:0% +university Professor I sit in my chair + + + align:start position:0% +university Professor I sit in my chair +and think most of the time uh a person + + align:start position:0% +and think most of the time uh a person + + + align:start position:0% +and think most of the time uh a person +uh you know somebody strong out there in + + align:start position:0% +uh you know somebody strong out there in + + + align:start position:0% +uh you know somebody strong out there in +the field mounting modules say if if + + align:start position:0% +the field mounting modules say if if + + + align:start position:0% +the field mounting modules say if if +Jessica in the back were module + + align:start position:0% +Jessica in the back were module + + + align:start position:0% +Jessica in the back were module +installer she could lift this no problem + + align:start position:0% +installer she could lift this no problem + + + align:start position:0% +installer she could lift this no problem +probably with her pinky finger and + + align:start position:0% +probably with her pinky finger and + + + align:start position:0% +probably with her pinky finger and +that's why there bite-sized right + + align:start position:0% +that's why there bite-sized right + + + align:start position:0% +that's why there bite-sized right +they're they're a single person liftable + + align:start position:0% +they're they're a single person liftable + + + align:start position:0% +they're they're a single person liftable +uh installable modules you can't make + + align:start position:0% +uh installable modules you can't make + + + align:start position:0% +uh installable modules you can't make +them too big or else you start needing + + align:start position:0% +them too big or else you start needing + + + align:start position:0% +them too big or else you start needing +cranes uh which of course has its own + + align:start position:0% +cranes uh which of course has its own + + + align:start position:0% +cranes uh which of course has its own +benefits for large field installations + + align:start position:0% +benefits for large field installations + + + align:start position:0% +benefits for large field installations +wouldn't really make sense with our + + align:start position:0% +wouldn't really make sense with our + + + align:start position:0% +wouldn't really make sense with our +current mode of installation on + + align:start position:0% +current mode of installation on + + + align:start position:0% +current mode of installation on +residential yeah the um so if you had a + + align:start position:0% +residential yeah the um so if you had a + + + align:start position:0% +residential yeah the um so if you had a +battery if you were powering a or + + align:start position:0% +battery if you were powering a or + + + align:start position:0% +battery if you were powering a or +charging a battery with this the module + + align:start position:0% +charging a battery with this the module + + + align:start position:0% +charging a battery with this the module +you also wouldn't want to have too many + + align:start position:0% +you also wouldn't want to have too many + + + align:start position:0% +you also wouldn't want to have too many +volts right I guess maybe that's a + + align:start position:0% +volts right I guess maybe that's a + + + align:start position:0% +volts right I guess maybe that's a +really basic Electronics question yeah + + align:start position:0% +really basic Electronics question yeah + + + align:start position:0% +really basic Electronics question yeah +so the question is can you can can you + + align:start position:0% +so the question is can you can can you + + + align:start position:0% +so the question is can you can can you +can you uh do you benefit by having + + align:start position:0% +can you uh do you benefit by having + + + align:start position:0% +can you uh do you benefit by having +larger over potential uh when when + + align:start position:0% +larger over potential uh when when + + + align:start position:0% +larger over potential uh when when +recharging a battery um while I'm not a + + align:start position:0% +recharging a battery um while I'm not a + + + align:start position:0% +recharging a battery um while I'm not a +battery expert uh so I'll definitely + + align:start position:0% +battery expert uh so I'll definitely + + + align:start position:0% +battery expert uh so I'll definitely +caution on this I would imagine uh that + + align:start position:0% +caution on this I would imagine uh that + + + align:start position:0% +caution on this I would imagine uh that +there would be some law of diminishing + + align:start position:0% +there would be some law of diminishing + + + align:start position:0% +there would be some law of diminishing +returns you would be limited in terms of + + align:start position:0% +returns you would be limited in terms of + + + align:start position:0% +returns you would be limited in terms of +the recharge rate not by the over + + align:start position:0% +the recharge rate not by the over + + + align:start position:0% +the recharge rate not by the over +potential but by by some other component + + align:start position:0% +potential but by by some other component + + + align:start position:0% +potential but by by some other component +like the electrolyte diffusivity let's + + align:start position:0% +like the electrolyte diffusivity let's + + + align:start position:0% +like the electrolyte diffusivity let's +say uh inside of your system uh as an + + align:start position:0% +say uh inside of your system uh as an + + + align:start position:0% +say uh inside of your system uh as an +example but I would I would defer that + + align:start position:0% +example but I would I would defer that + + + align:start position:0% +example but I would I would defer that +to the battery experts my impression + + align:start position:0% +to the battery experts my impression + + + align:start position:0% +to the battery experts my impression +though is that you get a lot of + + align:start position:0% +though is that you get a lot of + + + align:start position:0% +though is that you get a lot of +diminishing + + align:start position:0% +diminishing + + + align:start position:0% +diminishing +returns um packing fraction in the + + align:start position:0% +returns um packing fraction in the + + + align:start position:0% +returns um packing fraction in the +modules so we talked about the different + + align:start position:0% +modules so we talked about the different + + + align:start position:0% +modules so we talked about the different +uh cell sizes um if you're processing + + align:start position:0% +uh cell sizes um if you're processing + + + align:start position:0% +uh cell sizes um if you're processing +discret cells um the higher packing + + align:start position:0% +discret cells um the higher packing + + + align:start position:0% +discret cells um the higher packing +fraction enables lower glass and + + align:start position:0% +fraction enables lower glass and + + + align:start position:0% +fraction enables lower glass and +capsulin and cost per Watt peak uh the + + align:start position:0% +capsulin and cost per Watt peak uh the + + + align:start position:0% +capsulin and cost per Watt peak uh the +lower packing fraction you get to play + + align:start position:0% +lower packing fraction you get to play + + + align:start position:0% +lower packing fraction you get to play +some games with Optical concentration uh + + align:start position:0% +some games with Optical concentration uh + + + align:start position:0% +some games with Optical concentration uh +for here for instance if you have space + + align:start position:0% +for here for instance if you have space + + + align:start position:0% +for here for instance if you have space +between your cells uh you can uh have a + + align:start position:0% +between your cells uh you can uh have a + + + align:start position:0% +between your cells uh you can uh have a +diffuse luran scatterer in the back + + align:start position:0% +diffuse luran scatterer in the back + + + align:start position:0% +diffuse luran scatterer in the back +which uh will reflect the light at a + + align:start position:0% +which uh will reflect the light at a + + + align:start position:0% +which uh will reflect the light at a +different angle uh scattering it and + + align:start position:0% +different angle uh scattering it and + + + align:start position:0% +different angle uh scattering it and +that light could be trapped by total + + align:start position:0% +that light could be trapped by total + + + align:start position:0% +that light could be trapped by total +internal reflection inside of the glass + + align:start position:0% +internal reflection inside of the glass + + + align:start position:0% +internal reflection inside of the glass +if the angle um reaching the glass is + + align:start position:0% +if the angle um reaching the glass is + + + align:start position:0% +if the angle um reaching the glass is +say 15° or greater so you can play some + + align:start position:0% +say 15° or greater so you can play some + + + align:start position:0% +say 15° or greater so you can play some +games there uh that's why the tedlar + + align:start position:0% +games there uh that's why the tedlar + + + align:start position:0% +games there uh that's why the tedlar +back skin being white is typically used + + align:start position:0% +back skin being white is typically used + + + align:start position:0% +back skin being white is typically used +in most solar modules right so that we + + align:start position:0% +in most solar modules right so that we + + + align:start position:0% +in most solar modules right so that we +scatter or we reflect and then scatter + + align:start position:0% +scatter or we reflect and then scatter + + + align:start position:0% +scatter or we reflect and then scatter +and then trap the light that comes in in + + align:start position:0% +and then trap the light that comes in in + + + align:start position:0% +and then trap the light that comes in in +between the + + align:start position:0% + + + + align:start position:0% + +cells so to put this into another um you + + align:start position:0% +cells so to put this into another um you + + + align:start position:0% +cells so to put this into another um you +know just a another fancier + + align:start position:0% +know just a another fancier + + + align:start position:0% +know just a another fancier +threedimensional framework we have our + + align:start position:0% +threedimensional framework we have our + + + align:start position:0% +threedimensional framework we have our +interconnected cells we have our + + align:start position:0% +interconnected cells we have our + + + align:start position:0% +interconnected cells we have our +encapsulin above and below the + + align:start position:0% +encapsulin above and below the + + + align:start position:0% +encapsulin above and below the +encapsulant material is an interesting + + align:start position:0% +encapsulant material is an interesting + + + align:start position:0% +encapsulant material is an interesting +thing it's solid at room temperature but + + align:start position:0% +thing it's solid at room temperature but + + + align:start position:0% +thing it's solid at room temperature but +it begins to flow at around 15075 de C + + align:start position:0% +it begins to flow at around 15075 de C + + + align:start position:0% +it begins to flow at around 15075 de C +which means um you you you if you've + + align:start position:0% +which means um you you you if you've + + + align:start position:0% +which means um you you you if you've +ever seen if you ever put a a plastic + + align:start position:0% +ever seen if you ever put a a plastic + + + align:start position:0% +ever seen if you ever put a a plastic +bottle in the oven and you've noticed + + align:start position:0% +bottle in the oven and you've noticed + + + align:start position:0% +bottle in the oven and you've noticed +how it begins to melt and sag and droop + + align:start position:0% +how it begins to melt and sag and droop + + + align:start position:0% +how it begins to melt and sag and droop +um that that's essentially the type of + + align:start position:0% +um that that's essentially the type of + + + align:start position:0% +um that that's essentially the type of +flow that you would experience inside of + + align:start position:0% +flow that you would experience inside of + + + align:start position:0% +flow that you would experience inside of +this encapsulate material and it flows + + align:start position:0% +this encapsulate material and it flows + + + align:start position:0% +this encapsulate material and it flows +around the cells and it fuses them + + align:start position:0% +around the cells and it fuses them + + + align:start position:0% +around the cells and it fuses them +together with the glass on top uh and + + align:start position:0% +together with the glass on top uh and + + + align:start position:0% +together with the glass on top uh and +they stick together once they cool down + + align:start position:0% +they stick together once they cool down + + + align:start position:0% +they stick together once they cool down +to room temperature um that forms what's + + align:start position:0% +to room temperature um that forms what's + + + align:start position:0% +to room temperature um that forms what's +called a laminate because now you have + + align:start position:0% +called a laminate because now you have + + + align:start position:0% +called a laminate because now you have +the the um the back skin the frame isn't + + align:start position:0% +the the um the back skin the frame isn't + + + align:start position:0% +the the um the back skin the frame isn't +shown right here um you have the back + + align:start position:0% +shown right here um you have the back + + + align:start position:0% +shown right here um you have the back +skin material you have the encapsulant + + align:start position:0% +skin material you have the encapsulant + + + align:start position:0% +skin material you have the encapsulant +the cells the encapsulant on the other + + align:start position:0% +the cells the encapsulant on the other + + + align:start position:0% +the cells the encapsulant on the other +side and your glass on the front side + + align:start position:0% +side and your glass on the front side + + + align:start position:0% +side and your glass on the front side +right all together forming a nice stack + + align:start position:0% +right all together forming a nice stack + + + align:start position:0% +right all together forming a nice stack +of materials and they're stuck together + + align:start position:0% +of materials and they're stuck together + + + align:start position:0% +of materials and they're stuck together +Bound by the encapsulant that's called + + align:start position:0% +Bound by the encapsulant that's called + + + align:start position:0% +Bound by the encapsulant that's called +called the laminate it's it doesn't + + align:start position:0% +called the laminate it's it doesn't + + + align:start position:0% +called the laminate it's it doesn't +resist bending very well or twist very + + align:start position:0% +resist bending very well or twist very + + + align:start position:0% +resist bending very well or twist very +well because it doesn't yet have the + + align:start position:0% +well because it doesn't yet have the + + + align:start position:0% +well because it doesn't yet have the +frame on it but it certainly can be + + align:start position:0% +frame on it but it certainly can be + + + align:start position:0% +frame on it but it certainly can be +transported around a factory and moved + + align:start position:0% +transported around a factory and moved + + + align:start position:0% +transported around a factory and moved +from one station to another without risk + + align:start position:0% +from one station to another without risk + + + align:start position:0% +from one station to another without risk +of saying the cells falling out um + + align:start position:0% +of saying the cells falling out um + + + align:start position:0% +of saying the cells falling out um +they're they're pretty well fused there + + align:start position:0% +they're they're pretty well fused there + + + align:start position:0% +they're they're pretty well fused there +um in terms of of moving to New + + align:start position:0% +um in terms of of moving to New + + + align:start position:0% +um in terms of of moving to New +materials there's a lot of work right + + align:start position:0% +materials there's a lot of work right + + + align:start position:0% +materials there's a lot of work right +now to squeeze the commodity costs out + + align:start position:0% +now to squeeze the commodity costs out + + + align:start position:0% +now to squeeze the commodity costs out +of solar module manufacturing if you + + align:start position:0% +of solar module manufacturing if you + + + align:start position:0% +of solar module manufacturing if you +look at the percentage of cost of + + align:start position:0% +look at the percentage of cost of + + + align:start position:0% +look at the percentage of cost of +commodity materials in the Solar module + + align:start position:0% +commodity materials in the Solar module + + + align:start position:0% +commodity materials in the Solar module +is quite high and so people are focusing + + align:start position:0% +is quite high and so people are focusing + + + align:start position:0% +is quite high and so people are focusing +on new types of transparent front + + align:start position:0% +on new types of transparent front + + + align:start position:0% +on new types of transparent front +surface materials that let the light in + + align:start position:0% +surface materials that let the light in + + + align:start position:0% +surface materials that let the light in +glass Replacements right you could + + align:start position:0% +glass Replacements right you could + + + align:start position:0% +glass Replacements right you could +Envision uh um you you we have many + + align:start position:0% +Envision uh um you you we have many + + + align:start position:0% +Envision uh um you you we have many +examples of really hard resistant + + align:start position:0% +examples of really hard resistant + + + align:start position:0% +examples of really hard resistant +polymeric materials in our daily lives + + align:start position:0% +polymeric materials in our daily lives + + + align:start position:0% +polymeric materials in our daily lives +people are looking into those the + + align:start position:0% +people are looking into those the + + + align:start position:0% +people are looking into those the +encapsulant materials ethinyl acetate is + + align:start position:0% +encapsulant materials ethinyl acetate is + + + align:start position:0% +encapsulant materials ethinyl acetate is +fairly expensive and there aren't that + + align:start position:0% +fairly expensive and there aren't that + + + align:start position:0% +fairly expensive and there aren't that +many companies that manufacture it and + + align:start position:0% +many companies that manufacture it and + + + align:start position:0% +many companies that manufacture it and +so people are looking to options to + + align:start position:0% +so people are looking to options to + + + align:start position:0% +so people are looking to options to +replace it uh tedlar even more so that + + align:start position:0% +replace it uh tedlar even more so that + + + align:start position:0% +replace it uh tedlar even more so that +back skin material although the + + align:start position:0% +back skin material although the + + + align:start position:0% +back skin material although the +challenge there is a lot harder a lot + + align:start position:0% +challenge there is a lot harder a lot + + + align:start position:0% +challenge there is a lot harder a lot +tougher no intendo it's a really strong + + align:start position:0% +tougher no intendo it's a really strong + + + align:start position:0% +tougher no intendo it's a really strong +material um and uh a lot of our uh + + align:start position:0% +material um and uh a lot of our uh + + + align:start position:0% +material um and uh a lot of our uh +Modern Chemistry or or chemical + + align:start position:0% +Modern Chemistry or or chemical + + + align:start position:0% +Modern Chemistry or or chemical +engineering goes into making and + + align:start position:0% +engineering goes into making and + + + align:start position:0% +engineering goes into making and +designing it and then finally finding + + align:start position:0% +designing it and then finally finding + + + align:start position:0% +designing it and then finally finding +some replacement for the frame uh people + + align:start position:0% +some replacement for the frame uh people + + + align:start position:0% +some replacement for the frame uh people +are talking about frameless modules that + + align:start position:0% +are talking about frameless modules that + + + align:start position:0% +are talking about frameless modules that +means taking off this aluminum piece + + align:start position:0% +means taking off this aluminum piece + + + align:start position:0% +means taking off this aluminum piece +right here on the side and just leaving + + align:start position:0% +right here on the side and just leaving + + + align:start position:0% +right here on the side and just leaving +the laminate and somehow providing the + + align:start position:0% +the laminate and somehow providing the + + + align:start position:0% +the laminate and somehow providing the +mechanical rigidity to the laminate uh + + align:start position:0% +mechanical rigidity to the laminate uh + + + align:start position:0% +mechanical rigidity to the laminate uh +and avoiding the cost of the extruded + + align:start position:0% +and avoiding the cost of the extruded + + + align:start position:0% +and avoiding the cost of the extruded +aluminum components so a lot of work + + align:start position:0% +aluminum components so a lot of work + + + align:start position:0% +aluminum components so a lot of work +going in uh in module + + align:start position:0% +going in uh in module + + + align:start position:0% +going in uh in module +Design This is a picture of folks + + align:start position:0% +Design This is a picture of folks + + + align:start position:0% +Design This is a picture of folks +mounting the aluminum framing onto the + + align:start position:0% +mounting the aluminum framing onto the + + + align:start position:0% +mounting the aluminum framing onto the +module uh these are uh these are uh + + align:start position:0% +module uh these are uh these are uh + + + align:start position:0% +module uh these are uh these are uh +essentially U large look like steel + + align:start position:0% +essentially U large look like steel + + + align:start position:0% +essentially U large look like steel +components that are pushing the aluminum + + align:start position:0% +components that are pushing the aluminum + + + align:start position:0% +components that are pushing the aluminum +into the module and uh making sure that + + align:start position:0% +into the module and uh making sure that + + + align:start position:0% +into the module and uh making sure that +there's a snug fit between the aluminum + + align:start position:0% +there's a snug fit between the aluminum + + + align:start position:0% +there's a snug fit between the aluminum +and the module itself as you can see by + + align:start position:0% +and the module itself as you can see by + + + align:start position:0% +and the module itself as you can see by +the size and shapes of these cells that + + align:start position:0% +the size and shapes of these cells that + + + align:start position:0% +the size and shapes of these cells that +gives you an indication of what company + + align:start position:0% +gives you an indication of what company + + + align:start position:0% +gives you an indication of what company +that that + + align:start position:0% +that that + + + align:start position:0% +that that +is um module technology there's there's + + align:start position:0% +is um module technology there's there's + + + align:start position:0% +is um module technology there's there's +uh some work as well going into replace + + align:start position:0% +uh some work as well going into replace + + + align:start position:0% +uh some work as well going into replace +replacing let's see here we go uh + + align:start position:0% +replacing let's see here we go uh + + + align:start position:0% +replacing let's see here we go uh +replacing the tabing stringing step + + align:start position:0% +replacing the tabing stringing step + + + align:start position:0% +replacing the tabing stringing step +right so this is a machine that tabs and + + align:start position:0% +right so this is a machine that tabs and + + + align:start position:0% +right so this is a machine that tabs and +strings the cells to one another we'll + + align:start position:0% +strings the cells to one another we'll + + + align:start position:0% +strings the cells to one another we'll +see one at frown Hopper it's really + + align:start position:0% +see one at frown Hopper it's really + + + align:start position:0% +see one at frown Hopper it's really +impressive When You See It Go but it's + + align:start position:0% +impressive When You See It Go but it's + + + align:start position:0% +impressive When You See It Go but it's +also quite expensive um and so if you + + align:start position:0% +also quite expensive um and so if you + + + align:start position:0% +also quite expensive um and so if you +can get rid of the tabing stringy + + align:start position:0% +can get rid of the tabing stringy + + + align:start position:0% +can get rid of the tabing stringy +imagine just lying up the little cells + + align:start position:0% +imagine just lying up the little cells + + + align:start position:0% +imagine just lying up the little cells +like cookies on a cookie sheet and they + + align:start position:0% +like cookies on a cookie sheet and they + + + align:start position:0% +like cookies on a cookie sheet and they +all are interconnected by contact with + + align:start position:0% +all are interconnected by contact with + + + align:start position:0% +all are interconnected by contact with +whatever Back skin material is on the + + align:start position:0% +whatever Back skin material is on the + + + align:start position:0% +whatever Back skin material is on the +back that is printed let's say with a + + align:start position:0% +back that is printed let's say with a + + + align:start position:0% +back that is printed let's say with a +circuitry already you would wind up in a + + align:start position:0% +circuitry already you would wind up in a + + + align:start position:0% +circuitry already you would wind up in a +situation like this where you have your + + align:start position:0% +situation like this where you have your + + + align:start position:0% +situation like this where you have your +cells and direct contact with some + + align:start position:0% +cells and direct contact with some + + + align:start position:0% +cells and direct contact with some +printed circuitry on your back boom boom + + align:start position:0% +printed circuitry on your back boom boom + + + align:start position:0% +printed circuitry on your back boom boom +boom boom boom and you're off and + + align:start position:0% +boom boom boom and you're off and + + + align:start position:0% +boom boom boom and you're off and +running in this particular case you see + + align:start position:0% +running in this particular case you see + + + align:start position:0% +running in this particular case you see +this these little white dots here um the + + align:start position:0% +this these little white dots here um the + + + align:start position:0% +this these little white dots here um the +grid pattern on that cell is a radial + + align:start position:0% +grid pattern on that cell is a radial + + + align:start position:0% +grid pattern on that cell is a radial +spider pattern that emanates a spider + + align:start position:0% +spider pattern that emanates a spider + + + align:start position:0% +spider pattern that emanates a spider +web pattern that emanates from that + + align:start position:0% +web pattern that emanates from that + + + align:start position:0% +web pattern that emanates from that +Central Point collects current from + + align:start position:0% +Central Point collects current from + + + align:start position:0% +Central Point collects current from +nearby essentially an area about that + + align:start position:0% +nearby essentially an area about that + + + align:start position:0% +nearby essentially an area about that +big is collected let's say by that + + align:start position:0% +big is collected let's say by that + + + align:start position:0% +big is collected let's say by that +little point right there and then + + align:start position:0% +little point right there and then + + + align:start position:0% +little point right there and then +there's a hole drilled through the solar + + align:start position:0% +there's a hole drilled through the solar + + + align:start position:0% +there's a hole drilled through the solar +cell where the metal is wrapping through + + align:start position:0% +cell where the metal is wrapping through + + + align:start position:0% +cell where the metal is wrapping through +to the back and that's where it's making + + align:start position:0% +to the back and that's where it's making + + + align:start position:0% +to the back and that's where it's making +contact with the backside right there + + align:start position:0% +contact with the backside right there + + + align:start position:0% +contact with the backside right there +and then there are other regions of the + + align:start position:0% +and then there are other regions of the + + + align:start position:0% +and then there are other regions of the +solar cell that are uh are making + + align:start position:0% +solar cell that are uh are making + + + align:start position:0% +solar cell that are uh are making +contact with the the the bulk the base + + align:start position:0% +contact with the the the bulk the base + + + align:start position:0% +contact with the the the bulk the base +if you will so you have both of your n + + align:start position:0% +if you will so you have both of your n + + + align:start position:0% +if you will so you have both of your n +and your P type contacts on the back + + align:start position:0% +and your P type contacts on the back + + + align:start position:0% +and your P type contacts on the back +side of your solar cell and that's + + align:start position:0% +side of your solar cell and that's + + + align:start position:0% +side of your solar cell and that's +what's shown in this drawing uh so there + + align:start position:0% +what's shown in this drawing uh so there + + + align:start position:0% +what's shown in this drawing uh so there +are attempts as well to put all of the + + align:start position:0% +are attempts as well to put all of the + + + align:start position:0% +are attempts as well to put all of the +contacts or connect the contacts onto + + align:start position:0% +contacts or connect the contacts onto + + + align:start position:0% +contacts or connect the contacts onto +the back to enable this monolithic uh + + align:start position:0% +the back to enable this monolithic uh + + + align:start position:0% +the back to enable this monolithic uh +manufacturing yes how is that + + align:start position:0% +manufacturing yes how is that + + + align:start position:0% +manufacturing yes how is that +short okay so um how's that not a short + + align:start position:0% +short okay so um how's that not a short + + + align:start position:0% +short okay so um how's that not a short +let me show you how that would not not + + align:start position:0% +let me show you how that would not not + + + align:start position:0% +let me show you how that would not not +be a + + align:start position:0% +be a + + + align:start position:0% +be a +short what I'm going to do is attempt to + + align:start position:0% +short what I'm going to do is attempt to + + + align:start position:0% +short what I'm going to do is attempt to +draw uh two different cell designs that + + align:start position:0% +draw uh two different cell designs that + + + align:start position:0% +draw uh two different cell designs that +um could lead to not + + align:start position:0% +um could lead to not + + + align:start position:0% +um could lead to not +shorting one cell design that could lead + + align:start position:0% +shorting one cell design that could lead + + + align:start position:0% +shorting one cell design that could lead +to not shorting would be let's say this + + align:start position:0% +to not shorting would be let's say this + + + align:start position:0% +to not shorting would be let's say this +would be our front surface um our base + + align:start position:0% +would be our front surface um our base + + + align:start position:0% +would be our front surface um our base +is I'm going to draw it flat here on the + + align:start position:0% +is I'm going to draw it flat here on the + + + align:start position:0% +is I'm going to draw it flat here on the +back just for Simplicity but it could be + + align:start position:0% +back just for Simplicity but it could be + + + align:start position:0% +back just for Simplicity but it could be +textured as well um I'm going to call + + align:start position:0% +textured as well um I'm going to call + + + align:start position:0% +textured as well um I'm going to call +this uh lightly + + align:start position:0% + + + + align:start position:0% + +doped uh lightly doped semiconductor + + align:start position:0% +doped uh lightly doped semiconductor + + + align:start position:0% +doped uh lightly doped semiconductor +material and then I could have heavily + + align:start position:0% +material and then I could have heavily + + + align:start position:0% +material and then I could have heavily +doped um uh let's say U this would be + + align:start position:0% +doped um uh let's say U this would be + + + align:start position:0% +doped um uh let's say U this would be +I'm going to I'm going to exaggerate + + align:start position:0% +I'm going to I'm going to exaggerate + + + align:start position:0% +I'm going to I'm going to exaggerate +here just for for effect this could be + + align:start position:0% +here just for for effect this could be + + + align:start position:0% +here just for for effect this could be +my positively my my heavily n type doped + + align:start position:0% +my positively my my heavily n type doped + + + align:start position:0% +my positively my my heavily n type doped +material this could be my heavily ptype + + align:start position:0% +material this could be my heavily ptype + + + align:start position:0% +material this could be my heavily ptype +doped material so I'm drawing p+ n plus + + align:start position:0% +doped material so I'm drawing p+ n plus + + + align:start position:0% +doped material so I'm drawing p+ n plus +another n plus another p+ right so I + + align:start position:0% +another n plus another p+ right so I + + + align:start position:0% +another n plus another p+ right so I +have um charge separation occurring at + + align:start position:0% +have um charge separation occurring at + + + align:start position:0% +have um charge separation occurring at +these regions right here and then + + align:start position:0% +these regions right here and then + + + align:start position:0% +these regions right here and then +contacts on the other side this is my + + align:start position:0% +contacts on the other side this is my + + + align:start position:0% +contacts on the other side this is my +electron contact this is my ho contact + + align:start position:0% +electron contact this is my ho contact + + + align:start position:0% +electron contact this is my ho contact +this is my electron contact this is my + + align:start position:0% +this is my electron contact this is my + + + align:start position:0% +this is my electron contact this is my +ho contact and now what's happening is + + align:start position:0% +ho contact and now what's happening is + + + align:start position:0% +ho contact and now what's happening is +charge separate or photo excited + + align:start position:0% +charge separate or photo excited + + + align:start position:0% +charge separate or photo excited +carriers are being generated in here but + + align:start position:0% +carriers are being generated in here but + + + align:start position:0% +carriers are being generated in here but +the field that separates them is all in + + align:start position:0% +the field that separates them is all in + + + align:start position:0% +the field that separates them is all in +the back and so now the carriers are + + align:start position:0% +the back and so now the carriers are + + + align:start position:0% +the back and so now the carriers are +being separated electrons being + + align:start position:0% +being separated electrons being + + + align:start position:0% +being separated electrons being +collected by the dark or shaded rather + + align:start position:0% +collected by the dark or shaded rather + + + align:start position:0% +collected by the dark or shaded rather +the shaded areas and the holes being + + align:start position:0% +the shaded areas and the holes being + + + align:start position:0% +the shaded areas and the holes being +collected by these unshaded contacts + + align:start position:0% +collected by these unshaded contacts + + + align:start position:0% +collected by these unshaded contacts +here in the back and if I'm clever about + + align:start position:0% +here in the back and if I'm clever about + + + align:start position:0% +here in the back and if I'm clever about +my contact positioning right here I have + + align:start position:0% +my contact positioning right here I have + + + align:start position:0% +my contact positioning right here I have +a kind of an interdigitated P or + + align:start position:0% +a kind of an interdigitated P or + + + align:start position:0% +a kind of an interdigitated P or +electron and whole collectors right I'm + + align:start position:0% +electron and whole collectors right I'm + + + align:start position:0% +electron and whole collectors right I'm +able to uh collect both without having + + align:start position:0% +able to uh collect both without having + + + align:start position:0% +able to uh collect both without having +any sort of shunting another design + + align:start position:0% +any sort of shunting another design + + + align:start position:0% +any sort of shunting another design +might + + align:start position:0% +might + + + align:start position:0% +might +be let's see so this is called an in + + align:start position:0% +be let's see so this is called an in + + + align:start position:0% +be let's see so this is called an in +digitated back contact structure or + + align:start position:0% +digitated back contact structure or + + + align:start position:0% +digitated back contact structure or +IBC um actually less relevant in that in + + align:start position:0% +IBC um actually less relevant in that in + + + align:start position:0% +IBC um actually less relevant in that in +in in this particular case in most in + + align:start position:0% +in in this particular case in most in + + + align:start position:0% +in in this particular case in most in +most in digitated back Conta cells it's + + align:start position:0% +most in digitated back Conta cells it's + + + align:start position:0% +most in digitated back Conta cells it's +it's actually an N type silicon lightly + + align:start position:0% +it's actually an N type silicon lightly + + + align:start position:0% +it's actually an N type silicon lightly +doped n type silicon just because Point + + align:start position:0% +doped n type silicon just because Point + + + align:start position:0% +doped n type silicon just because Point +defects tend to have smaller capture + + align:start position:0% +defects tend to have smaller capture + + + align:start position:0% +defects tend to have smaller capture +cross-section an N type silicon and + + align:start position:0% +cross-section an N type silicon and + + + align:start position:0% +cross-section an N type silicon and +ptype silicon so minority care lifetime + + align:start position:0% +ptype silicon so minority care lifetime + + + align:start position:0% +ptype silicon so minority care lifetime +tends to be larger another uh cell + + align:start position:0% +tends to be larger another uh cell + + + align:start position:0% +tends to be larger another uh cell +design again looking in cross-section + + align:start position:0% +design again looking in cross-section + + + align:start position:0% +design again looking in cross-section +you might have uh here this being your + + align:start position:0% +you might have uh here this being your + + + align:start position:0% +you might have uh here this being your +solar cell um you could add texture but + + align:start position:0% +solar cell um you could add texture but + + + align:start position:0% +solar cell um you could add texture but +I'm emitting it just for for Simplicity + + align:start position:0% +I'm emitting it just for for Simplicity + + + align:start position:0% +I'm emitting it just for for Simplicity +uh now let's see we um we drill a hole + + align:start position:0% +uh now let's see we um we drill a hole + + + align:start position:0% +uh now let's see we um we drill a hole +using a laser right here so we have a + + align:start position:0% +using a laser right here so we have a + + + align:start position:0% +using a laser right here so we have a +very thin hole um of course the in three + + align:start position:0% +very thin hole um of course the in three + + + align:start position:0% +very thin hole um of course the in three +dimensions there's mechanical rigidity + + align:start position:0% +dimensions there's mechanical rigidity + + + align:start position:0% +dimensions there's mechanical rigidity +by the bulk of the material in the other + + align:start position:0% +by the bulk of the material in the other + + + align:start position:0% +by the bulk of the material in the other +dimension but we have this whole drilled + + align:start position:0% +dimension but we have this whole drilled + + + align:start position:0% +dimension but we have this whole drilled +through and we can make about 18,000 of + + align:start position:0% +through and we can make about 18,000 of + + + align:start position:0% +through and we can make about 18,000 of +these holes in about 6 seconds with + + align:start position:0% +these holes in about 6 seconds with + + + align:start position:0% +these holes in about 6 seconds with +modern Laser Technology so it's really + + align:start position:0% +modern Laser Technology so it's really + + + align:start position:0% +modern Laser Technology so it's really +not that hard and and and in to to make + + align:start position:0% +not that hard and and and in to to make + + + align:start position:0% +not that hard and and and in to to make +this uh happen although a lot of + + align:start position:0% +this uh happen although a lot of + + + align:start position:0% +this uh happen although a lot of +engineering effort is is put into it but + + align:start position:0% +engineering effort is is put into it but + + + align:start position:0% +engineering effort is is put into it but +it is possible and then you could have + + align:start position:0% +it is possible and then you could have + + + align:start position:0% +it is possible and then you could have +your contact metalization say for + + align:start position:0% +your contact metalization say for + + + align:start position:0% +your contact metalization say for +electrons right + + align:start position:0% + + + + align:start position:0% + +here um you could have the PN + + align:start position:0% +here um you could have the PN + + + align:start position:0% +here um you could have the PN +Junction like + + align:start position:0% +Junction like + + + align:start position:0% +Junction like +this so This Here could be your n Plus + + align:start position:0% +this so This Here could be your n Plus + + + align:start position:0% +this so This Here could be your n Plus +material again n plus material this by + + align:start position:0% +material again n plus material this by + + + align:start position:0% +material again n plus material this by +uh effect would also be and you could + + align:start position:0% +uh effect would also be and you could + + + align:start position:0% +uh effect would also be and you could +have your P materials over here um and + + align:start position:0% +have your P materials over here um and + + + align:start position:0% +have your P materials over here um and +you can make contact to the back right + + align:start position:0% +you can make contact to the back right + + + align:start position:0% +you can make contact to the back right +here and contact to the back right here + + align:start position:0% +here and contact to the back right here + + + align:start position:0% +here and contact to the back right here +and as long as there's no uh short or + + align:start position:0% +and as long as there's no uh short or + + + align:start position:0% +and as long as there's no uh short or +metal short between the electron and + + align:start position:0% +metal short between the electron and + + + align:start position:0% +metal short between the electron and +hole you say for example you generate an + + align:start position:0% +hole you say for example you generate an + + + align:start position:0% +hole you say for example you generate an +electron hole pair here the electron + + align:start position:0% +electron hole pair here the electron + + + align:start position:0% +electron hole pair here the electron +goes up to here it goes through the + + align:start position:0% +goes up to here it goes through the + + + align:start position:0% +goes up to here it goes through the +metal to the back and gets pulled out + + align:start position:0% +metal to the back and gets pulled out + + + align:start position:0% +metal to the back and gets pulled out +and the hole goes to this contact over + + align:start position:0% +and the hole goes to this contact over + + + align:start position:0% +and the hole goes to this contact over +here + + align:start position:0% +here + + + align:start position:0% +here +and that's how you separate the charges + + align:start position:0% +and that's how you separate the charges + + + align:start position:0% +and that's how you separate the charges +so this would be an example of uh an + + align:start position:0% +so this would be an example of uh an + + + align:start position:0% +so this would be an example of uh an +emitter wrap through or metal wrap + + align:start position:0% +emitter wrap through or metal wrap + + + align:start position:0% +emitter wrap through or metal wrap +through uh device + + align:start position:0% +through uh device + + + align:start position:0% +through uh device +technology also shown mwt metal wrap + + align:start position:0% +technology also shown mwt metal wrap + + + align:start position:0% +technology also shown mwt metal wrap +through um so we have at least two + + align:start position:0% +through um so we have at least two + + + align:start position:0% +through um so we have at least two +different device geometries and and many + + align:start position:0% +different device geometries and and many + + + align:start position:0% +different device geometries and and many +more many more device architectures that + + align:start position:0% +more many more device architectures that + + + align:start position:0% +more many more device architectures that +could fit in with this uh Future Vision + + align:start position:0% +could fit in with this uh Future Vision + + + align:start position:0% +could fit in with this uh Future Vision +the problem right now is that the + + align:start position:0% +the problem right now is that the + + + align:start position:0% +the problem right now is that the +printed uh back skin materials cost + + align:start position:0% +printed uh back skin materials cost + + + align:start position:0% +printed uh back skin materials cost +about five times more than the + + align:start position:0% +about five times more than the + + + align:start position:0% +about five times more than the +non-printed ones just because they're + + align:start position:0% +non-printed ones just because they're + + + align:start position:0% +non-printed ones just because they're +very low scale uh people haven't inv + + align:start position:0% +very low scale uh people haven't inv + + + align:start position:0% +very low scale uh people haven't inv +investigated it much so anytime you + + align:start position:0% +investigated it much so anytime you + + + align:start position:0% +investigated it much so anytime you +introduce a new technology into the + + align:start position:0% +introduce a new technology into the + + + align:start position:0% +introduce a new technology into the +market you'll hear it over and over + + align:start position:0% +market you'll hear it over and over + + + align:start position:0% +market you'll hear it over and over +again in these Innovation and + + align:start position:0% +again in these Innovation and + + + align:start position:0% +again in these Innovation and +Entrepreneurship classes here at MIT you + + align:start position:0% +Entrepreneurship classes here at MIT you + + + align:start position:0% +Entrepreneurship classes here at MIT you +have to be significantly better than the + + align:start position:0% +have to be significantly better than the + + + align:start position:0% +have to be significantly better than the +competition if you're only a little bit + + align:start position:0% +competition if you're only a little bit + + + align:start position:0% +competition if you're only a little bit +better you face an enormous barrier to + + align:start position:0% +better you face an enormous barrier to + + + align:start position:0% +better you face an enormous barrier to +entry because you have the rest of the + + align:start position:0% +entry because you have the rest of the + + + align:start position:0% +entry because you have the rest of the +industry pedaling Along on their + + align:start position:0% +industry pedaling Along on their + + + align:start position:0% +industry pedaling Along on their +bicycles in a huge pelaton benefiting + + align:start position:0% +bicycles in a huge pelaton benefiting + + + align:start position:0% +bicycles in a huge pelaton benefiting +from each other's Drafting and you're on + + align:start position:0% +from each other's Drafting and you're on + + + align:start position:0% +from each other's Drafting and you're on +your own bike facing your own headwinds + + align:start position:0% +your own bike facing your own headwinds + + + align:start position:0% +your own bike facing your own headwinds +right trying to build everything up your + + align:start position:0% +right trying to build everything up your + + + align:start position:0% +right trying to build everything up your +own Factory your own expertise it's + + align:start position:0% +own Factory your own expertise it's + + + align:start position:0% +own Factory your own expertise it's +challenging but not to say I'm I'm not + + align:start position:0% +challenging but not to say I'm I'm not + + + align:start position:0% +challenging but not to say I'm I'm not +putting trying to put put a damper on + + align:start position:0% +putting trying to put put a damper on + + + align:start position:0% +putting trying to put put a damper on +Innovation I'm just trying to qualify + + align:start position:0% +Innovation I'm just trying to qualify + + + align:start position:0% +Innovation I'm just trying to qualify +the areas of greatest opportunity and + + align:start position:0% +the areas of greatest opportunity and + + + align:start position:0% +the areas of greatest opportunity and +lowest resistance to to change but go + + align:start position:0% +lowest resistance to to change but go + + + align:start position:0% +lowest resistance to to change but go +ahead prove me wrong make make a + + align:start position:0% +ahead prove me wrong make make a + + + align:start position:0% +ahead prove me wrong make make a +difference um the uh with with without + + align:start position:0% +difference um the uh with with without + + + align:start position:0% +difference um the uh with with without +that sort of Headstrong uh mentality of + + align:start position:0% +that sort of Headstrong uh mentality of + + + align:start position:0% +that sort of Headstrong uh mentality of +gosh I know I have something here and + + align:start position:0% +gosh I know I have something here and + + + align:start position:0% +gosh I know I have something here and +I'm just going to prove the world that I + + align:start position:0% +I'm just going to prove the world that I + + + align:start position:0% +I'm just going to prove the world that I +have it we wouldn't have for example the + + align:start position:0% +have it we wouldn't have for example the + + + align:start position:0% +have it we wouldn't have for example the +Pilkington plate glass process working + + align:start position:0% +Pilkington plate glass process working + + + align:start position:0% +Pilkington plate glass process working +or float glass process sorry um we'd + + align:start position:0% +or float glass process sorry um we'd + + + align:start position:0% +or float glass process sorry um we'd +still probably be pouring and grinding + + align:start position:0% +still probably be pouring and grinding + + + align:start position:0% +still probably be pouring and grinding +and polishing our panes of glass and + + align:start position:0% +and polishing our panes of glass and + + + align:start position:0% +and polishing our panes of glass and +they'd be very expensive um that was a a + + align:start position:0% +they'd be very expensive um that was a a + + + align:start position:0% +they'd be very expensive um that was a a +a little side story but it took them + + align:start position:0% +a little side story but it took them + + + align:start position:0% +a little side story but it took them +about 10 years to develop the the float + + align:start position:0% +about 10 years to develop the the float + + + align:start position:0% +about 10 years to develop the the float +glass process inside of a company owned + + align:start position:0% +glass process inside of a company owned + + + align:start position:0% +glass process inside of a company owned +by a family as opposed to publicly + + align:start position:0% +by a family as opposed to publicly + + + align:start position:0% +by a family as opposed to publicly +traded company so they could continue + + align:start position:0% +traded company so they could continue + + + align:start position:0% +traded company so they could continue +losing money over a long period of time + + align:start position:0% +losing money over a long period of time + + + align:start position:0% +losing money over a long period of time +until they perfected it once they got it + + align:start position:0% +until they perfected it once they got it + + + align:start position:0% +until they perfected it once they got it +right the whole world copied it but it + + align:start position:0% +right the whole world copied it but it + + + align:start position:0% +right the whole world copied it but it +took 10 years of of good investment for + + align:start position:0% +took 10 years of of good investment for + + + align:start position:0% +took 10 years of of good investment for +them to get it right all right um let's + + align:start position:0% +them to get it right all right um let's + + + align:start position:0% +them to get it right all right um let's +move on uh we're going to talk about + + align:start position:0% +move on uh we're going to talk about + + + align:start position:0% +move on uh we're going to talk about +module spec sheets here um you when you + + align:start position:0% +module spec sheets here um you when you + + + align:start position:0% +module spec sheets here um you when you +came into class today you should have + + align:start position:0% +came into class today you should have + + + align:start position:0% +came into class today you should have +picked up one of + + align:start position:0% +picked up one of + + + align:start position:0% +picked up one of +these uh this is an example of a First + + align:start position:0% +these uh this is an example of a First + + + align:start position:0% +these uh this is an example of a First +Solar module spec sheet um what it does + + align:start position:0% +Solar module spec sheet um what it does + + + align:start position:0% +Solar module spec sheet um what it does +hits you front and center the company + + align:start position:0% +hits you front and center the company + + + align:start position:0% +hits you front and center the company +name for solar uh FS Series 3 that's the + + align:start position:0% +name for solar uh FS Series 3 that's the + + + align:start position:0% +name for solar uh FS Series 3 that's the +name of the module and PV module so uh + + align:start position:0% +name of the module and PV module so uh + + + align:start position:0% +name of the module and PV module so uh +it gives you the mechanical description + + align:start position:0% +it gives you the mechanical description + + + align:start position:0% +it gives you the mechanical description +the size the weight um and then on the + + align:start position:0% +the size the weight um and then on the + + + align:start position:0% +the size the weight um and then on the +back it gives you all the technical + + align:start position:0% +back it gives you all the technical + + + align:start position:0% +back it gives you all the technical +parameters that you've wanted so on the + + align:start position:0% +parameters that you've wanted so on the + + + align:start position:0% +parameters that you've wanted so on the +back side of the let's see we'll go to + + align:start position:0% +back side of the let's see we'll go to + + + align:start position:0% +back side of the let's see we'll go to +the go to the First Solar spec okay well + + align:start position:0% +the go to the First Solar spec okay well + + + align:start position:0% +the go to the First Solar spec okay well +um on your spec sheet right here you can + + align:start position:0% +um on your spec sheet right here you can + + + align:start position:0% +um on your spec sheet right here you can +look at some of the parameters there's + + align:start position:0% +look at some of the parameters there's + + + align:start position:0% +look at some of the parameters there's +power at the maximum PowerPoint voltage + + align:start position:0% +power at the maximum PowerPoint voltage + + + align:start position:0% +power at the maximum PowerPoint voltage +and current at the maximum PowerPoint um + + align:start position:0% +and current at the maximum PowerPoint um + + + align:start position:0% +and current at the maximum PowerPoint um +the vocc the ISC and so forth you have a + + align:start position:0% +the vocc the ISC and so forth you have a + + + align:start position:0% +the vocc the ISC and so forth you have a +bunch of different parameters including + + align:start position:0% +bunch of different parameters including + + + align:start position:0% +bunch of different parameters including +the temperature uh sensitivity right how + + align:start position:0% +the temperature uh sensitivity right how + + + align:start position:0% +the temperature uh sensitivity right how +much does the power degrade with + + align:start position:0% +much does the power degrade with + + + align:start position:0% +much does the power degrade with +increasing temperature so all of these + + align:start position:0% +increasing temperature so all of these + + + align:start position:0% +increasing temperature so all of these +things we studied in class and now when + + align:start position:0% +things we studied in class and now when + + + align:start position:0% +things we studied in class and now when +you pick up the spec sheet you're a pro + + align:start position:0% +you pick up the spec sheet you're a pro + + + align:start position:0% +you pick up the spec sheet you're a pro +you look at it you're like oh yeah I + + align:start position:0% +you look at it you're like oh yeah I + + + align:start position:0% +you look at it you're like oh yeah I +know what that does I know what that + + align:start position:0% +know what that does I know what that + + + align:start position:0% +know what that does I know what that +means I know how to model the the energy + + align:start position:0% +means I know how to model the the energy + + + align:start position:0% +means I know how to model the the energy +output of the system and um and that's + + align:start position:0% +output of the system and um and that's + + + align:start position:0% +output of the system and um and that's +essentially what the engineers do when + + align:start position:0% +essentially what the engineers do when + + + align:start position:0% +essentially what the engineers do when +they pick up a spec sheet uh they read + + align:start position:0% +they pick up a spec sheet uh they read + + + align:start position:0% +they pick up a spec sheet uh they read +it and then they input those parameters + + align:start position:0% +it and then they input those parameters + + + align:start position:0% +it and then they input those parameters +into their computer models and they can + + align:start position:0% +into their computer models and they can + + + align:start position:0% +into their computer models and they can +predict how this these modules will + + align:start position:0% +predict how this these modules will + + + align:start position:0% +predict how this these modules will +perform out in the field at a given + + align:start position:0% +perform out in the field at a given + + + align:start position:0% +perform out in the field at a given +location okay and so you have a variety + + align:start position:0% +location okay and so you have a variety + + + align:start position:0% +location okay and so you have a variety +of different spec sheets these are the + + align:start position:0% +of different spec sheets these are the + + + align:start position:0% +of different spec sheets these are the +the modules that are on my roof uh + + align:start position:0% +the modules that are on my roof uh + + + align:start position:0% +the modules that are on my roof uh +they're sharp 187 watt modules um you + + align:start position:0% +they're sharp 187 watt modules um you + + + align:start position:0% +they're sharp 187 watt modules um you +have for example uh right here an + + align:start position:0% +have for example uh right here an + + + align:start position:0% +have for example uh right here an +example of an evergreen solar module + + align:start position:0% +example of an evergreen solar module + + + align:start position:0% +example of an evergreen solar module +let's let's spend a minute here looking + + align:start position:0% +let's let's spend a minute here looking + + + align:start position:0% +let's let's spend a minute here looking +a little more deeply um these modules + + align:start position:0% +a little more deeply um these modules + + + align:start position:0% +a little more deeply um these modules +these solar modules are the same size + + align:start position:0% +these solar modules are the same size + + + align:start position:0% +these solar modules are the same size +but they're three different uh three + + align:start position:0% +but they're three different uh three + + + align:start position:0% +but they're three different uh three +different Power outputs and I think we + + align:start position:0% +different Power outputs and I think we + + + align:start position:0% +different Power outputs and I think we +went through this already right we have + + align:start position:0% +went through this already right we have + + + align:start position:0% +went through this already right we have +good cells medium cells and bad cells + + align:start position:0% +good cells medium cells and bad cells + + + align:start position:0% +good cells medium cells and bad cells +and they're Bend together in the + + align:start position:0% +and they're Bend together in the + + + align:start position:0% +and they're Bend together in the +different modules so that they can + + align:start position:0% +different modules so that they can + + + align:start position:0% +different modules so that they can +extract the maximum price from the + + align:start position:0% +extract the maximum price from the + + + align:start position:0% +extract the maximum price from the +consumer right so that's why you have + + align:start position:0% +consumer right so that's why you have + + + align:start position:0% +consumer right so that's why you have +the three different uh ratings of power + + align:start position:0% +the three different uh ratings of power + + + align:start position:0% +the three different uh ratings of power +for three different types of modules + + align:start position:0% +for three different types of modules + + + align:start position:0% +for three different types of modules +with essentially the same form factor + + align:start position:0% +with essentially the same form factor + + + align:start position:0% +with essentially the same form factor +the same size and weight they're just + + align:start position:0% +the same size and weight they're just + + + align:start position:0% +the same size and weight they're just +different quality + + align:start position:0% +different quality + + + align:start position:0% +different quality +cells yep so that's that's that + + align:start position:0% +cells yep so that's that's that + + + align:start position:0% +cells yep so that's that's that +temperature coefficients + + align:start position:0% +temperature coefficients + + + align:start position:0% +temperature coefficients +so + + align:start position:0% +so + + + align:start position:0% +so +forth okay um one thing to note right + + align:start position:0% +forth okay um one thing to note right + + + align:start position:0% +forth okay um one thing to note right +here is uh on the back sides of your + + align:start position:0% +here is uh on the back sides of your + + + align:start position:0% +here is uh on the back sides of your +modules you typically have a little + + align:start position:0% +modules you typically have a little + + + align:start position:0% +modules you typically have a little +diagram that shows you how to + + align:start position:0% +diagram that shows you how to + + + align:start position:0% +diagram that shows you how to +interconnect one module to the next and + + align:start position:0% +interconnect one module to the next and + + + align:start position:0% +interconnect one module to the next and +those are the cables that are used uh to + + align:start position:0% +those are the cables that are used uh to + + + align:start position:0% +those are the cables that are used uh to +do the interconnection there are some + + align:start position:0% +do the interconnection there are some + + + align:start position:0% +do the interconnection there are some +companies trying to get fancy right now + + align:start position:0% +companies trying to get fancy right now + + + align:start position:0% +companies trying to get fancy right now +and saying well you know instead of uh + + align:start position:0% +and saying well you know instead of uh + + + align:start position:0% +and saying well you know instead of uh +interconnecting and then uh affixing the + + align:start position:0% +interconnecting and then uh affixing the + + + align:start position:0% +interconnecting and then uh affixing the +modules separately why don't we just + + align:start position:0% +modules separately why don't we just + + + align:start position:0% +modules separately why don't we just +make these modules that kind of click + + align:start position:0% +make these modules that kind of click + + + align:start position:0% +make these modules that kind of click +together and part of the clicking + + align:start position:0% +together and part of the clicking + + + align:start position:0% +together and part of the clicking +process is the interconnection + + align:start position:0% +process is the interconnection + + + align:start position:0% +process is the interconnection +electrically and the other part + + align:start position:0% +electrically and the other part + + + align:start position:0% +electrically and the other part +obviously is the mechanical rigidity so + + align:start position:0% +obviously is the mechanical rigidity so + + + align:start position:0% +obviously is the mechanical rigidity so +there there's certainly room for + + align:start position:0% +there there's certainly room for + + + align:start position:0% +there there's certainly room for +optimization on module + + align:start position:0% +optimization on module + + + align:start position:0% +optimization on module +design yeah Jessica when they're sold + + align:start position:0% +design yeah Jessica when they're sold + + + align:start position:0% +design yeah Jessica when they're sold +when the modules are sold they're + + align:start position:0% +when the modules are sold they're + + + align:start position:0% +when the modules are sold they're +advertised for their voltage at maximum + + align:start position:0% +advertised for their voltage at maximum + + + align:start position:0% +advertised for their voltage at maximum +power what's the software that we should + + align:start position:0% +power what's the software that we should + + + align:start position:0% +power what's the software that we should +use I'm actually using this from another + + align:start position:0% +use I'm actually using this from another + + + align:start position:0% +use I'm actually using this from another +class what's the software that we should + + align:start position:0% +class what's the software that we should + + + align:start position:0% +class what's the software that we should +use to use that maximum power point + + align:start position:0% +use to use that maximum power point + + + align:start position:0% +use to use that maximum power point +voltage into translate that into what + + align:start position:0% +voltage into translate that into what + + + align:start position:0% +voltage into translate that into what +it's actually going to be you know hours + + align:start position:0% +it's actually going to be you know hours + + + align:start position:0% +it's actually going to be you know hours +or + + align:start position:0% +or + + + align:start position:0% +or +something okay so um + + align:start position:0% +something okay so um + + + align:start position:0% +something okay so um +the the question became how do I go from + + align:start position:0% +the the question became how do I go from + + + align:start position:0% +the the question became how do I go from +a module spec sheet like this um with + + align:start position:0% +a module spec sheet like this um with + + + align:start position:0% +a module spec sheet like this um with +with this data right here and translate + + align:start position:0% +with this data right here and translate + + + align:start position:0% +with this data right here and translate +that into number of kilowatt hours + + align:start position:0% +that into number of kilowatt hours + + + align:start position:0% +that into number of kilowatt hours +produced per unit time a day a year um + + align:start position:0% +produced per unit time a day a year um + + + align:start position:0% +produced per unit time a day a year um +at a given site location the best + + align:start position:0% +at a given site location the best + + + align:start position:0% +at a given site location the best +program that I know of to to to that + + align:start position:0% +program that I know of to to to that + + + align:start position:0% +program that I know of to to to that +encompasses all of this would be a + + align:start position:0% +encompasses all of this would be a + + + align:start position:0% +encompasses all of this would be a +program called PV Watts produced by enal + + align:start position:0% +program called PV Watts produced by enal + + + align:start position:0% +program called PV Watts produced by enal +PV Watts Al together and uh you can look + + align:start position:0% +PV Watts Al together and uh you can look + + + align:start position:0% +PV Watts Al together and uh you can look +it up you can use it online and you can + + align:start position:0% +it up you can use it online and you can + + + align:start position:0% +it up you can use it online and you can +input uh your specific mod module spec + + align:start position:0% +input uh your specific mod module spec + + + align:start position:0% +input uh your specific mod module spec +parameters into the uh into the program + + align:start position:0% +parameters into the uh into the program + + + align:start position:0% +parameters into the uh into the program +now that said we have a lot of the tools + + align:start position:0% +now that said we have a lot of the tools + + + align:start position:0% +now that said we have a lot of the tools +to do the estimates ourselves if you uh + + align:start position:0% +to do the estimates ourselves if you uh + + + align:start position:0% +to do the estimates ourselves if you uh +ruffle back to homework I think it was + + align:start position:0% +ruffle back to homework I think it was + + + align:start position:0% +ruffle back to homework I think it was +homework number two uh we calculated the + + align:start position:0% +homework number two uh we calculated the + + + align:start position:0% +homework number two uh we calculated the +output of a solar system based on uh the + + align:start position:0% +output of a solar system based on uh the + + + align:start position:0% +output of a solar system based on uh the +module spec parameters and so now that + + align:start position:0% +module spec parameters and so now that + + + align:start position:0% +module spec parameters and so now that +we we uh can pick up a module spec sheet + + align:start position:0% +we we uh can pick up a module spec sheet + + + align:start position:0% +we we uh can pick up a module spec sheet +and read it in a bit more detail we can + + align:start position:0% +and read it in a bit more detail we can + + + align:start position:0% +and read it in a bit more detail we can +perform those estimates a little bit + + align:start position:0% +perform those estimates a little bit + + + align:start position:0% +perform those estimates a little bit +more + + align:start position:0% +more + + + align:start position:0% +more +accurately y + + align:start position:0% +accurately y + + + align:start position:0% +accurately y +firstar panel is a lot + + align:start position:0% +firstar panel is a lot + + + align:start position:0% +firstar panel is a lot +there yep so is there reason why First + + align:start position:0% +there yep so is there reason why First + + + align:start position:0% +there yep so is there reason why First +Solar goes smaller cells yeah so uh why + + align:start position:0% +Solar goes smaller cells yeah so uh why + + + align:start position:0% +Solar goes smaller cells yeah so uh why +why is this First Solar module the fs + + align:start position:0% +why is this First Solar module the fs + + + align:start position:0% +why is this First Solar module the fs +Series 3 module a little smaller than + + align:start position:0% +Series 3 module a little smaller than + + + align:start position:0% +Series 3 module a little smaller than +some of the Crystal and silicon modules + + align:start position:0% +some of the Crystal and silicon modules + + + align:start position:0% +some of the Crystal and silicon modules +four thin film deposition especially for + + align:start position:0% +four thin film deposition especially for + + + align:start position:0% +four thin film deposition especially for +this uh closed space sublimation process + + align:start position:0% +this uh closed space sublimation process + + + align:start position:0% +this uh closed space sublimation process +that for solar uses um you're limited in + + align:start position:0% +that for solar uses um you're limited in + + + align:start position:0% +that for solar uses um you're limited in +terms of the deposition area by the + + align:start position:0% +terms of the deposition area by the + + + align:start position:0% +terms of the deposition area by the +uniformity of that position over a large + + align:start position:0% +uniformity of that position over a large + + + align:start position:0% +uniformity of that position over a large +uh uh region so if you're sputtering the + + align:start position:0% +uh uh region so if you're sputtering the + + + align:start position:0% +uh uh region so if you're sputtering the +material uh it's typically related to to + + align:start position:0% +material uh it's typically related to to + + + align:start position:0% +material uh it's typically related to to +the size of your Target and the distance + + align:start position:0% +the size of your Target and the distance + + + align:start position:0% +the size of your Target and the distance +to your substrate um that will limit the + + align:start position:0% +to your substrate um that will limit the + + + align:start position:0% +to your substrate um that will limit the +maximum size that you can deposit + + align:start position:0% +maximum size that you can deposit + + + align:start position:0% +maximum size that you can deposit +uniformly and you probably want to + + align:start position:0% +uniformly and you probably want to + + + align:start position:0% +uniformly and you probably want to +deposit to within plus or minus 2% let's + + align:start position:0% +deposit to within plus or minus 2% let's + + + align:start position:0% +deposit to within plus or minus 2% let's +say maybe 5% I'm not extremely privy to + + align:start position:0% +say maybe 5% I'm not extremely privy to + + + align:start position:0% +say maybe 5% I'm not extremely privy to +the precise tolerances in the PV + + align:start position:0% +the precise tolerances in the PV + + + align:start position:0% +the precise tolerances in the PV +industry in terms of thin film thickness + + align:start position:0% +industry in terms of thin film thickness + + + align:start position:0% +industry in terms of thin film thickness +variation but that would be my my um my + + align:start position:0% +variation but that would be my my um my + + + align:start position:0% +variation but that would be my my um my +estimate um and in terms of these + + align:start position:0% +estimate um and in terms of these + + + align:start position:0% +estimate um and in terms of these +thermal evaporation processes again it's + + align:start position:0% +thermal evaporation processes again it's + + + align:start position:0% +thermal evaporation processes again it's +uh it's how the machine is designed so I + + align:start position:0% +uh it's how the machine is designed so I + + + align:start position:0% +uh it's how the machine is designed so I +imagine you could probably go bigger um + + align:start position:0% +imagine you could probably go bigger um + + + align:start position:0% +imagine you could probably go bigger um +um is it cost effective question mark + + align:start position:0% +um is it cost effective question mark + + + align:start position:0% +um is it cost effective question mark +somebody at First Solar most obviously + + align:start position:0% +somebody at First Solar most obviously + + + align:start position:0% +somebody at First Solar most obviously +did the cost analysis and said that this + + align:start position:0% +did the cost analysis and said that this + + + align:start position:0% +did the cost analysis and said that this +is the optimum between a variety of + + align:start position:0% +is the optimum between a variety of + + + align:start position:0% +is the optimum between a variety of +different factors between + + align:start position:0% +different factors between + + + align:start position:0% +different factors between +manufacturability and ease of + + align:start position:0% +manufacturability and ease of + + + align:start position:0% +manufacturability and ease of +installation yeah don't put efficiency + + align:start position:0% +installation yeah don't put efficiency + + + align:start position:0% +installation yeah don't put efficiency +on the sheet is there a reason why they + + align:start position:0% +on the sheet is there a reason why they + + + align:start position:0% +on the sheet is there a reason why they +don't put efficiency on the sheet well + + align:start position:0% +don't put efficiency on the sheet well + + + align:start position:0% +don't put efficiency on the sheet well +you could probably very easily calculate + + align:start position:0% +you could probably very easily calculate + + + align:start position:0% +you could probably very easily calculate +the efficiency right um there are two + + align:start position:0% +the efficiency right um there are two + + + align:start position:0% +the efficiency right um there are two +types of module efficiencies um there's + + align:start position:0% +types of module efficiencies um there's + + + align:start position:0% +types of module efficiencies um there's +what's called uh total area efficiency + + align:start position:0% +what's called uh total area efficiency + + + align:start position:0% +what's called uh total area efficiency +where you take the total area of your + + align:start position:0% +where you take the total area of your + + + align:start position:0% +where you take the total area of your +module all the way up to the aluminum + + align:start position:0% +module all the way up to the aluminum + + + align:start position:0% +module all the way up to the aluminum +frame and calculate that as your area so + + align:start position:0% +frame and calculate that as your area so + + + align:start position:0% +frame and calculate that as your area so +you take your power your maximum power + + align:start position:0% +you take your power your maximum power + + + align:start position:0% +you take your power your maximum power +uh rated at am 1.5 Sun conditions and + + align:start position:0% +uh rated at am 1.5 Sun conditions and + + + align:start position:0% +uh rated at am 1.5 Sun conditions and +divided by the area there's also um a + + align:start position:0% +divided by the area there's also um a + + + align:start position:0% +divided by the area there's also um a +variety of other uh less um + + align:start position:0% +variety of other uh less um + + + align:start position:0% +variety of other uh less um +straightforward ways of calculating + + align:start position:0% +straightforward ways of calculating + + + align:start position:0% +straightforward ways of calculating +efficiency some of which take the active + + align:start position:0% +efficiency some of which take the active + + + align:start position:0% +efficiency some of which take the active +area of the cells only others uh exclude + + align:start position:0% +area of the cells only others uh exclude + + + align:start position:0% +area of the cells only others uh exclude +the frame right and so the module + + align:start position:0% +the frame right and so the module + + + align:start position:0% +the frame right and so the module +efficiency um is not extremely + + align:start position:0% +efficiency um is not extremely + + + align:start position:0% +efficiency um is not extremely +straightforward parameter it has to be + + align:start position:0% +straightforward parameter it has to be + + + align:start position:0% +straightforward parameter it has to be +specified based on what areas is uh is + + align:start position:0% +specified based on what areas is uh is + + + align:start position:0% +specified based on what areas is uh is +assumed that would be my estimate for + + align:start position:0% +assumed that would be my estimate for + + + align:start position:0% +assumed that would be my estimate for +why they didn't put it right on here and + + align:start position:0% +why they didn't put it right on here and + + + align:start position:0% +why they didn't put it right on here and +secondly I mean their module efficiency + + align:start position:0% +secondly I mean their module efficiency + + + align:start position:0% +secondly I mean their module efficiency +if you do the math that one probably + + align:start position:0% +if you do the math that one probably + + + align:start position:0% +if you do the math that one probably +turns out to be somewhere between 11 and + + align:start position:0% +turns out to be somewhere between 11 and + + + align:start position:0% +turns out to be somewhere between 11 and +11.5% now they're hitting 12 or so um + + align:start position:0% +11.5% now they're hitting 12 or so um + + + align:start position:0% +11.5% now they're hitting 12 or so um +that's not a very high number compared + + align:start position:0% +that's not a very high number compared + + + align:start position:0% +that's not a very high number compared +to say a crystal and silicon module and + + align:start position:0% +to say a crystal and silicon module and + + + align:start position:0% +to say a crystal and silicon module and +so it wouldn't be it's probably + + align:start position:0% +so it wouldn't be it's probably + + + align:start position:0% +so it wouldn't be it's probably +something they advertise on their on + + align:start position:0% +something they advertise on their on + + + align:start position:0% +something they advertise on their on +their + + align:start position:0% + + + + align:start position:0% + +spec um describe how PV module power + + align:start position:0% +spec um describe how PV module power + + + align:start position:0% +spec um describe how PV module power +output is affected by the cell mismatch + + align:start position:0% +output is affected by the cell mismatch + + + align:start position:0% +output is affected by the cell mismatch +losses warning I'm going to lose some of + + align:start position:0% +losses warning I'm going to lose some of + + + align:start position:0% +losses warning I'm going to lose some of +you on this uh those of you without uh + + align:start position:0% +you on this uh those of you without uh + + + align:start position:0% +you on this uh those of you without uh +very strong uh electrical engineering or + + align:start position:0% +very strong uh electrical engineering or + + + align:start position:0% +very strong uh electrical engineering or +physics background I I'm going to pick + + align:start position:0% +physics background I I'm going to pick + + + align:start position:0% +physics background I I'm going to pick +you up at Point number three um so plan + + align:start position:0% +you up at Point number three um so plan + + + align:start position:0% +you up at Point number three um so plan +a flag right here uh we'll come back to + + align:start position:0% +a flag right here uh we'll come back to + + + align:start position:0% +a flag right here uh we'll come back to +it but for those who care to follow + + align:start position:0% +it but for those who care to follow + + + align:start position:0% +it but for those who care to follow +along um this is this is some really fun + + align:start position:0% +along um this is this is some really fun + + + align:start position:0% +along um this is this is some really fun +stuff that can get into why we want to + + align:start position:0% +stuff that can get into why we want to + + + align:start position:0% +stuff that can get into why we want to +match our cells properly in terms of + + align:start position:0% +match our cells properly in terms of + + + align:start position:0% +match our cells properly in terms of +their outputs right so the total current + + align:start position:0% +their outputs right so the total current + + + align:start position:0% +their outputs right so the total current +output this is the ideal diode equation + + align:start position:0% +output this is the ideal diode equation + + + align:start position:0% +output this is the ideal diode equation +all without all the fancy two diode + + align:start position:0% +all without all the fancy two diode + + + align:start position:0% +all without all the fancy two diode +model you know recombination the space + + align:start position:0% +model you know recombination the space + + + align:start position:0% +model you know recombination the space +charge region Rec combination the bulk + + align:start position:0% +charge region Rec combination the bulk + + + align:start position:0% +charge region Rec combination the bulk +without the series resistance and shunt + + align:start position:0% +without the series resistance and shunt + + + align:start position:0% +without the series resistance and shunt +resistance just a very simple um + + align:start position:0% +resistance just a very simple um + + + align:start position:0% +resistance just a very simple um +explanation of of the ideal di model + + align:start position:0% +explanation of of the ideal di model + + + align:start position:0% +explanation of of the ideal di model +what we're doing is we're our m is the + + align:start position:0% +what we're doing is we're our m is the + + + align:start position:0% +what we're doing is we're our m is the +number of cells in parallel and our N is + + align:start position:0% +number of cells in parallel and our N is + + + align:start position:0% +number of cells in parallel and our N is +a number of cells in series so we go + + align:start position:0% +a number of cells in series so we go + + + align:start position:0% +a number of cells in series so we go +back to our equivalent circuit diagrams + + align:start position:0% +back to our equivalent circuit diagrams + + + align:start position:0% +back to our equivalent circuit diagrams +where we have two say voltage current + + align:start position:0% +where we have two say voltage current + + + align:start position:0% +where we have two say voltage current +sources that are connected in series if + + align:start position:0% +sources that are connected in series if + + + align:start position:0% +sources that are connected in series if +you connect those two in series now the + + align:start position:0% +you connect those two in series now the + + + align:start position:0% +you connect those two in series now the +voltage will add right so the effective + + align:start position:0% +voltage will add right so the effective + + + align:start position:0% +voltage will add right so the effective +voltage across the entire system if you + + align:start position:0% +voltage across the entire system if you + + + align:start position:0% +voltage across the entire system if you +draw a black box around your two + + align:start position:0% +draw a black box around your two + + + align:start position:0% +draw a black box around your two +individual voltage producers the + + align:start position:0% +individual voltage producers the + + + align:start position:0% +individual voltage producers the +effective voltage across the entire + + align:start position:0% +effective voltage across the entire + + + align:start position:0% +effective voltage across the entire +system will be voltage 1 plus voltage + + align:start position:0% +system will be voltage 1 plus voltage + + + align:start position:0% +system will be voltage 1 plus voltage +two in series right um the currents now + + align:start position:0% +two in series right um the currents now + + + align:start position:0% +two in series right um the currents now +if you think about the current you can + + align:start position:0% +if you think about the current you can + + + align:start position:0% +if you think about the current you can +think of current the first order as this + + align:start position:0% +think of current the first order as this + + + align:start position:0% +think of current the first order as this +as this River trying to flow through a + + align:start position:0% +as this River trying to flow through a + + + align:start position:0% +as this River trying to flow through a +river of electrons trying to flow + + align:start position:0% +river of electrons trying to flow + + + align:start position:0% +river of electrons trying to flow +through your your circuit if there's any + + align:start position:0% +through your your circuit if there's any + + + align:start position:0% +through your your circuit if there's any +bottleneck somewhere that's going to + + align:start position:0% +bottleneck somewhere that's going to + + + align:start position:0% +bottleneck somewhere that's going to +limit the the current that can flow + + align:start position:0% +limit the the current that can flow + + + align:start position:0% +limit the the current that can flow +through the entire circuit um so the the + + align:start position:0% +through the entire circuit um so the the + + + align:start position:0% +through the entire circuit um so the the +current the combined current is going to + + align:start position:0% +current the combined current is going to + + + align:start position:0% +current the combined current is going to +be limited by the worst performer um in + + align:start position:0% +be limited by the worst performer um in + + + align:start position:0% +be limited by the worst performer um in +mathematical terms it would be the + + align:start position:0% +mathematical terms it would be the + + + align:start position:0% +mathematical terms it would be the +harmonic mean one over effective current + + align:start position:0% +harmonic mean one over effective current + + + align:start position:0% +harmonic mean one over effective current +would be one over current 1 plus one + + align:start position:0% +would be one over current 1 plus one + + + align:start position:0% +would be one over current 1 plus one +over current two right so um what we see + + align:start position:0% +over current two right so um what we see + + + align:start position:0% +over current two right so um what we see +here is if we have a number of cells + + align:start position:0% +here is if we have a number of cells + + + align:start position:0% +here is if we have a number of cells +connected in parallel um now instead of + + align:start position:0% +connected in parallel um now instead of + + + align:start position:0% +connected in parallel um now instead of +having to connected in series like this + + align:start position:0% +having to connected in series like this + + + align:start position:0% +having to connected in series like this +you connect them in parallel now the + + align:start position:0% +you connect them in parallel now the + + + align:start position:0% +you connect them in parallel now the +currents are adding and the voltage will + + align:start position:0% +currents are adding and the voltage will + + + align:start position:0% +currents are adding and the voltage will +be limited by the worst performer + + align:start position:0% +be limited by the worst performer + + + align:start position:0% +be limited by the worst performer +because the potential across both is + + align:start position:0% +because the potential across both is + + + align:start position:0% +because the potential across both is +going to be limited by whatever the + + align:start position:0% +going to be limited by whatever the + + + align:start position:0% +going to be limited by whatever the +lowest potential is so + + align:start position:0% +lowest potential is so + + + align:start position:0% +lowest potential is so +when we connect in parallel we add + + align:start position:0% +when we connect in parallel we add + + + align:start position:0% +when we connect in parallel we add +currents and when we connect in series + + align:start position:0% +currents and when we connect in series + + + align:start position:0% +currents and when we connect in series +we add voltages that's a very simple way + + align:start position:0% +we add voltages that's a very simple way + + + align:start position:0% +we add voltages that's a very simple way +to think about it and that's why we have + + align:start position:0% +to think about it and that's why we have + + + align:start position:0% +to think about it and that's why we have +the M appearing here up up top uh if you + + align:start position:0% +the M appearing here up up top uh if you + + + align:start position:0% +the M appearing here up up top uh if you +have a number of cells connected in + + align:start position:0% +have a number of cells connected in + + + align:start position:0% +have a number of cells connected in +parallel you will essentially be + + align:start position:0% +parallel you will essentially be + + + align:start position:0% +parallel you will essentially be +multiplying the illuminated current of + + align:start position:0% +multiplying the illuminated current of + + + align:start position:0% +multiplying the illuminated current of +one cell by whatever M it is and if you + + align:start position:0% +one cell by whatever M it is and if you + + + align:start position:0% +one cell by whatever M it is and if you +have uh a number of cells connected in + + align:start position:0% +have uh a number of cells connected in + + + align:start position:0% +have uh a number of cells connected in +series that will impact the + + align:start position:0% +series that will impact the + + + align:start position:0% +series that will impact the +voltage okay so um that's an expression + + align:start position:0% +voltage okay so um that's an expression + + + align:start position:0% +voltage okay so um that's an expression +that uh is useful for uh n and M number + + align:start position:0% +that uh is useful for uh n and M number + + + align:start position:0% +that uh is useful for uh n and M number +of identical cells identical cells + + align:start position:0% +of identical cells identical cells + + + align:start position:0% +of identical cells identical cells +connected in either series or parallel + + align:start position:0% +connected in either series or parallel + + + align:start position:0% +connected in either series or parallel +respectively and in practice if we have + + align:start position:0% +respectively and in practice if we have + + + align:start position:0% +respectively and in practice if we have +uh bad performers in the bunch if we + + align:start position:0% +uh bad performers in the bunch if we + + + align:start position:0% +uh bad performers in the bunch if we +have one cell that's performing worse + + align:start position:0% +have one cell that's performing worse + + + align:start position:0% +have one cell that's performing worse +than another either because it is + + align:start position:0% +than another either because it is + + + align:start position:0% +than another either because it is +intrinsically worse it is a defective + + align:start position:0% +intrinsically worse it is a defective + + + align:start position:0% +intrinsically worse it is a defective +cell that somehow got in there or became + + align:start position:0% +cell that somehow got in there or became + + + align:start position:0% +cell that somehow got in there or became +defective during use or it's a temporary + + align:start position:0% +defective during use or it's a temporary + + + align:start position:0% +defective during use or it's a temporary +effect maybe a seagull just landed on + + align:start position:0% +effect maybe a seagull just landed on + + + align:start position:0% +effect maybe a seagull just landed on +top of that cell and is shading it right + + align:start position:0% +top of that cell and is shading it right + + + align:start position:0% +top of that cell and is shading it right +um so whatever the reason is temporary + + align:start position:0% +um so whatever the reason is temporary + + + align:start position:0% +um so whatever the reason is temporary +or permanent um that uh cell number two + + align:start position:0% +or permanent um that uh cell number two + + + align:start position:0% +or permanent um that uh cell number two +now is is is a is a bad apple um and so + + align:start position:0% +now is is is a is a bad apple um and so + + + align:start position:0% +now is is is a is a bad apple um and so +if we're looking at parallel mismatches + + align:start position:0% +if we're looking at parallel mismatches + + + align:start position:0% +if we're looking at parallel mismatches +we take what we know about cells and + + align:start position:0% +we take what we know about cells and + + + align:start position:0% +we take what we know about cells and +parallel okay the voltage is limited by + + align:start position:0% +parallel okay the voltage is limited by + + + align:start position:0% +parallel okay the voltage is limited by +the worst performer and we look at the + + align:start position:0% +the worst performer and we look at the + + + align:start position:0% +the worst performer and we look at the +individual IV curves of the good and the + + align:start position:0% +individual IV curves of the good and the + + + align:start position:0% +individual IV curves of the good and the +bad cell this is the good cell right + + align:start position:0% +bad cell this is the good cell right + + + align:start position:0% +bad cell this is the good cell right +here this + + align:start position:0% +here this + + + align:start position:0% +here this +curve there right and so this now is + + align:start position:0% +curve there right and so this now is + + + align:start position:0% +curve there right and so this now is +being positive power essentially power + + align:start position:0% +being positive power essentially power + + + align:start position:0% +being positive power essentially power +coming out of the solar cell is plotted + + align:start position:0% +coming out of the solar cell is plotted + + + align:start position:0% +coming out of the solar cell is plotted +in the first quadrant we have uh a lot + + align:start position:0% +in the first quadrant we have uh a lot + + + align:start position:0% +in the first quadrant we have uh a lot +of power coming out and a large voltage + + align:start position:0% +of power coming out and a large voltage + + + align:start position:0% +of power coming out and a large voltage +for our good cell here's our bad cell + + align:start position:0% +for our good cell here's our bad cell + + + align:start position:0% +for our good cell here's our bad cell +right there right so slightly lower + + align:start position:0% +right there right so slightly lower + + + align:start position:0% +right there right so slightly lower +current output uh given by the the + + align:start position:0% +current output uh given by the the + + + align:start position:0% +current output uh given by the the +logarithmic effect and the um the + + align:start position:0% +logarithmic effect and the um the + + + align:start position:0% +logarithmic effect and the um the +voltage is lower significantly lower + + align:start position:0% +voltage is lower significantly lower + + + align:start position:0% +voltage is lower significantly lower +than say the good cell and so the + + align:start position:0% +than say the good cell and so the + + + align:start position:0% +than say the good cell and so the +combined output right here the current + + align:start position:0% +combined output right here the current + + + align:start position:0% +combined output right here the current +at Short Circuit current conditions is + + align:start position:0% +at Short Circuit current conditions is + + + align:start position:0% +at Short Circuit current conditions is +going to be the sum of the good and the + + align:start position:0% +going to be the sum of the good and the + + + align:start position:0% +going to be the sum of the good and the +bad so that's there the voltage is going + + align:start position:0% +bad so that's there the voltage is going + + + align:start position:0% +bad so that's there the voltage is going +to be the harmonic mean so limited by + + align:start position:0% +to be the harmonic mean so limited by + + + align:start position:0% +to be the harmonic mean so limited by +the the worst + + align:start position:0% +the the worst + + + align:start position:0% +the the worst +performer that's uh how uh low voltage + + align:start position:0% +performer that's uh how uh low voltage + + + align:start position:0% +performer that's uh how uh low voltage +cells can really mess up parallel + + align:start position:0% +cells can really mess up parallel + + + align:start position:0% +cells can really mess up parallel +strings so for example this set of of of + + align:start position:0% +strings so for example this set of of of + + + align:start position:0% +strings so for example this set of of of +two rows of cells this one right here uh + + align:start position:0% +two rows of cells this one right here uh + + + align:start position:0% +two rows of cells this one right here uh +which is all connected in series is + + align:start position:0% +which is all connected in series is + + + align:start position:0% +which is all connected in series is +connected in parallel to this one and + + align:start position:0% +connected in parallel to this one and + + + align:start position:0% +connected in parallel to this one and +this one right and so if one of these + + align:start position:0% +this one right and so if one of these + + + align:start position:0% +this one right and so if one of these +one of these three uh subsets of cells + + align:start position:0% +one of these three uh subsets of cells + + + align:start position:0% +one of these three uh subsets of cells +has a lower voltage than the others the + + align:start position:0% +has a lower voltage than the others the + + + align:start position:0% +has a lower voltage than the others the +combined voltage output of the of the + + align:start position:0% +combined voltage output of the of the + + + align:start position:0% +combined voltage output of the of the +entire module will be lower lower + + align:start position:0% +entire module will be lower lower + + + align:start position:0% +entire module will be lower lower +similarly now we've put them in series + + align:start position:0% +similarly now we've put them in series + + + align:start position:0% +similarly now we've put them in series +uh if we have a bad cell that's + + align:start position:0% +uh if we have a bad cell that's + + + align:start position:0% +uh if we have a bad cell that's +producing less current than the good + + align:start position:0% +producing less current than the good + + + align:start position:0% +producing less current than the good +cell and notice that they same open + + align:start position:0% +cell and notice that they same open + + + align:start position:0% +cell and notice that they same open +circuit voltage now just for uh just for + + align:start position:0% +circuit voltage now just for uh just for + + + align:start position:0% +circuit voltage now just for uh just for +a say the the the thought experiment + + align:start position:0% +a say the the the thought experiment + + + align:start position:0% +a say the the the thought experiment +here in the classroom um typically if a + + align:start position:0% +here in the classroom um typically if a + + + align:start position:0% +here in the classroom um typically if a +cell is performing worse than current it + + align:start position:0% +cell is performing worse than current it + + + align:start position:0% +cell is performing worse than current it +will also have a lower voltage but just + + align:start position:0% +will also have a lower voltage but just + + + align:start position:0% +will also have a lower voltage but just +for the thought experiment right here we + + align:start position:0% +for the thought experiment right here we + + + align:start position:0% +for the thought experiment right here we +have um bad cell good cell bad cell has + + align:start position:0% +have um bad cell good cell bad cell has + + + align:start position:0% +have um bad cell good cell bad cell has +half the current of the good cell so the + + align:start position:0% +half the current of the good cell so the + + + align:start position:0% +half the current of the good cell so the +voltage output in series is going to be + + align:start position:0% +voltage output in series is going to be + + + align:start position:0% +voltage output in series is going to be +the addition of the two boom boom and + + align:start position:0% +the addition of the two boom boom and + + + align:start position:0% +the addition of the two boom boom and +you're up to here but the current output + + align:start position:0% +you're up to here but the current output + + + align:start position:0% +you're up to here but the current output +will be limited by the worst performer + + align:start position:0% +will be limited by the worst performer + + + align:start position:0% +will be limited by the worst performer +and again the combined output of this uh + + align:start position:0% +and again the combined output of this uh + + + align:start position:0% +and again the combined output of this uh +set of cells connected in series is + + align:start position:0% +set of cells connected in series is + + + align:start position:0% +set of cells connected in series is +going to be right around here and So + + align:start position:0% +going to be right around here and So + + + align:start position:0% +going to be right around here and So +based on your cell performance if you + + align:start position:0% +based on your cell performance if you + + + align:start position:0% +based on your cell performance if you +know that my Vol if if you know that + + align:start position:0% +know that my Vol if if you know that + + + align:start position:0% +know that my Vol if if you know that +your voltage has a certain variance in + + align:start position:0% +your voltage has a certain variance in + + + align:start position:0% +your voltage has a certain variance in +your manufacturing line and your current + + align:start position:0% +your manufacturing line and your current + + + align:start position:0% +your manufacturing line and your current +has a certain variance in your + + align:start position:0% +has a certain variance in your + + + align:start position:0% +has a certain variance in your +manufacturing line that might entice you + + align:start position:0% +manufacturing line that might entice you + + + align:start position:0% +manufacturing line that might entice you +to string together your cells in one way + + align:start position:0% +to string together your cells in one way + + + align:start position:0% +to string together your cells in one way +or another right depending on on how you + + align:start position:0% +or another right depending on on how you + + + align:start position:0% +or another right depending on on how you +want to mitigate your + + align:start position:0% +want to mitigate your + + + align:start position:0% +want to mitigate your +losses shaded cells so up to now + + align:start position:0% +losses shaded cells so up to now + + + align:start position:0% +losses shaded cells so up to now +everybody kind of gets based on on on on + + align:start position:0% +everybody kind of gets based on on on on + + + align:start position:0% +everybody kind of gets based on on on on +kof's laws and so forth from from + + align:start position:0% +kof's laws and so forth from from + + + align:start position:0% +kof's laws and so forth from from +equivalent circuit diagram so we're + + align:start position:0% +equivalent circuit diagram so we're + + + align:start position:0% +equivalent circuit diagram so we're +we're rolling now we're going to get to + + align:start position:0% +we're rolling now we're going to get to + + + align:start position:0% +we're rolling now we're going to get to +shaded cells and here's where uh it + + align:start position:0% +shaded cells and here's where uh it + + + align:start position:0% +shaded cells and here's where uh it +becomes a little bit more difficult to + + align:start position:0% +becomes a little bit more difficult to + + + align:start position:0% +becomes a little bit more difficult to +understand absent the reading in in that + + align:start position:0% +understand absent the reading in in that + + + align:start position:0% +understand absent the reading in in that +book over there did everybody get a + + align:start position:0% +book over there did everybody get a + + + align:start position:0% +book over there did everybody get a +chance to see the blue book did it make + + align:start position:0% +chance to see the blue book did it make + + + align:start position:0% +chance to see the blue book did it make +its rounds over here no didn't why don't + + align:start position:0% +its rounds over here no didn't why don't + + + align:start position:0% +its rounds over here no didn't why don't +we pass the uh the Blue Book around Omar + + align:start position:0% +we pass the uh the Blue Book around Omar + + + align:start position:0% +we pass the uh the Blue Book around Omar +over there I and get a chance to see it + + align:start position:0% +over there I and get a chance to see it + + + align:start position:0% +over there I and get a chance to see it +yet we're going to consider that we have + + align:start position:0% +yet we're going to consider that we have + + + align:start position:0% +yet we're going to consider that we have +10 identical solar cells connected in + + align:start position:0% +10 identical solar cells connected in + + + align:start position:0% +10 identical solar cells connected in +series and this one over here is shaded + + align:start position:0% +series and this one over here is shaded + + + align:start position:0% +series and this one over here is shaded +what happens + + align:start position:0% +what happens + + + align:start position:0% +what happens +now so uh this is described I believe in + + align:start position:0% +now so uh this is described I believe in + + + align:start position:0% +now so uh this is described I believe in +figure 5.7 in the book one with the + + align:start position:0% +figure 5.7 in the book one with the + + + align:start position:0% +figure 5.7 in the book one with the +green little tab we've assumed that the + + align:start position:0% +green little tab we've assumed that the + + + align:start position:0% +green little tab we've assumed that the +combined IV characteristic of the N good + + align:start position:0% +combined IV characteristic of the N good + + + align:start position:0% +combined IV characteristic of the N good +cells is this one right + + align:start position:0% +cells is this one right + + + align:start position:0% +cells is this one right +here and the one bad cell is this right + + align:start position:0% +here and the one bad cell is this right + + + align:start position:0% +here and the one bad cell is this right +here right so it's a little bit of a uh + + align:start position:0% +here right so it's a little bit of a uh + + + align:start position:0% +here right so it's a little bit of a uh +say a strange IV characteristic and um + + align:start position:0% +say a strange IV characteristic and um + + + align:start position:0% +say a strange IV characteristic and um +what happens next if you combine the two + + align:start position:0% +what happens next if you combine the two + + + align:start position:0% +what happens next if you combine the two +in series and you use the same protocol + + align:start position:0% +in series and you use the same protocol + + + align:start position:0% +in series and you use the same protocol +that we've done so far the voltage will + + align:start position:0% +that we've done so far the voltage will + + + align:start position:0% +that we've done so far the voltage will +add so whatever voltage gain right here + + align:start position:0% +add so whatever voltage gain right here + + + align:start position:0% +add so whatever voltage gain right here +has been added over here but the current + + align:start position:0% +has been added over here but the current + + + align:start position:0% +has been added over here but the current +is going to be limited by the worst + + align:start position:0% +is going to be limited by the worst + + + align:start position:0% +is going to be limited by the worst +performer which happens to be this uh + + align:start position:0% +performer which happens to be this uh + + + align:start position:0% +performer which happens to be this uh +solar cell right here and so the + + align:start position:0% +solar cell right here and so the + + + align:start position:0% +solar cell right here and so the +combined output is going to be lower + + align:start position:0% +combined output is going to be lower + + + align:start position:0% +combined output is going to be lower +significantly lower than uh than those + + align:start position:0% +significantly lower than uh than those + + + align:start position:0% +significantly lower than uh than those +of the good cells and that's what + + align:start position:0% +of the good cells and that's what + + + align:start position:0% +of the good cells and that's what +happens when one cell in a string is + + align:start position:0% +happens when one cell in a string is + + + align:start position:0% +happens when one cell in a string is +shaded if there aren't any fancy + + align:start position:0% +shaded if there aren't any fancy + + + align:start position:0% +shaded if there aren't any fancy +Electronics to allow the current to + + align:start position:0% +Electronics to allow the current to + + + align:start position:0% +Electronics to allow the current to +bypass it furthermore this amount of + + align:start position:0% +bypass it furthermore this amount of + + + align:start position:0% +bypass it furthermore this amount of +power will be dissipated in the bad cell + + align:start position:0% +power will be dissipated in the bad cell + + + align:start position:0% +power will be dissipated in the bad cell +when the string is short + + align:start position:0% +when the string is short + + + align:start position:0% +when the string is short +circuited it can change a bit when you + + align:start position:0% +circuited it can change a bit when you + + + align:start position:0% +circuited it can change a bit when you +start uh moving toward operating + + align:start position:0% +start uh moving toward operating + + + align:start position:0% +start uh moving toward operating +conditions but it's a sizable amount of + + align:start position:0% +conditions but it's a sizable amount of + + + align:start position:0% +conditions but it's a sizable amount of +power being dumped into that bad cell + + align:start position:0% +power being dumped into that bad cell + + + align:start position:0% +power being dumped into that bad cell +and in in in practice that cell is + + align:start position:0% +and in in in practice that cell is + + + align:start position:0% +and in in in practice that cell is +reverse biased let me show you using uh + + align:start position:0% +reverse biased let me show you using uh + + + align:start position:0% +reverse biased let me show you using uh +our wonderful ppcd ROM + + align:start position:0% +our wonderful ppcd ROM + + + align:start position:0% +our wonderful ppcd ROM +um exactly why that + + align:start position:0% +um exactly why that + + + align:start position:0% +um exactly why that +is so here we have two solar cells + + align:start position:0% +is so here we have two solar cells + + + align:start position:0% +is so here we have two solar cells +connected in series and they're both + + align:start position:0% +connected in series and they're both + + + align:start position:0% +connected in series and they're both +producing an equal amount of uh of + + align:start position:0% +producing an equal amount of uh of + + + align:start position:0% +producing an equal amount of uh of +current because they have an equal + + align:start position:0% +current because they have an equal + + + align:start position:0% +current because they have an equal +number of these yellow arrows incident + + align:start position:0% +number of these yellow arrows incident + + + align:start position:0% +number of these yellow arrows incident +on them and they're equal in every other + + align:start position:0% +on them and they're equal in every other + + + align:start position:0% +on them and they're equal in every other +aspect so it's still a thought + + align:start position:0% +aspect so it's still a thought + + + align:start position:0% +aspect so it's still a thought +experiment right now um the current that + + align:start position:0% +experiment right now um the current that + + + align:start position:0% +experiment right now um the current that +is cycling through this circuit in the + + align:start position:0% +is cycling through this circuit in the + + + align:start position:0% +is cycling through this circuit in the +external circuit right here uh is the + + align:start position:0% +external circuit right here uh is the + + + align:start position:0% +external circuit right here uh is the +strength of the magnitude of that + + align:start position:0% +strength of the magnitude of that + + + align:start position:0% +strength of the magnitude of that +current is being indicated by the color + + align:start position:0% +current is being indicated by the color + + + align:start position:0% +current is being indicated by the color +in this particular case it's very bright + + align:start position:0% +in this particular case it's very bright + + + align:start position:0% +in this particular case it's very bright +it's bright green it indicates a lot of + + align:start position:0% +it's bright green it indicates a lot of + + + align:start position:0% +it's bright green it indicates a lot of +current is flowing through it so up to + + align:start position:0% +current is flowing through it so up to + + + align:start position:0% +current is flowing through it so up to +now every everything makes sense this is + + align:start position:0% +now every everything makes sense this is + + + align:start position:0% +now every everything makes sense this is +in short circuit conditions so there's + + align:start position:0% +in short circuit conditions so there's + + + align:start position:0% +in short circuit conditions so there's +no voltage there's no potential across + + align:start position:0% +no voltage there's no potential across + + + align:start position:0% +no voltage there's no potential across +either cell it's in short circuit + + align:start position:0% +either cell it's in short circuit + + + align:start position:0% +either cell it's in short circuit +conditions and current is flowing + + align:start position:0% +conditions and current is flowing + + + align:start position:0% +conditions and current is flowing +through this circuit right here now I'm + + align:start position:0% +through this circuit right here now I'm + + + align:start position:0% +through this circuit right here now I'm +going to mismatch the two cells I'm + + align:start position:0% +going to mismatch the two cells I'm + + + align:start position:0% +going to mismatch the two cells I'm +going to exchange one of the cells for a + + align:start position:0% +going to exchange one of the cells for a + + + align:start position:0% +going to exchange one of the cells for a +a bad + + align:start position:0% +a bad + + + align:start position:0% +a bad +apple okay first off I I know just from + + align:start position:0% +apple okay first off I I know just from + + + align:start position:0% +apple okay first off I I know just from +uh what we've been talking about so far + + align:start position:0% +uh what we've been talking about so far + + + align:start position:0% +uh what we've been talking about so far +that the current is limited by the worst + + align:start position:0% +that the current is limited by the worst + + + align:start position:0% +that the current is limited by the worst +performer that the current flowing + + align:start position:0% +performer that the current flowing + + + align:start position:0% +performer that the current flowing +through the external circuit is now + + align:start position:0% +through the external circuit is now + + + align:start position:0% +through the external circuit is now +going to be lower and the first order + + align:start position:0% +going to be lower and the first order + + + align:start position:0% +going to be lower and the first order +it's it's more or less approximate to + + align:start position:0% +it's it's more or less approximate to + + + align:start position:0% +it's it's more or less approximate to +what uh the current is in this bad cell + + align:start position:0% +what uh the current is in this bad cell + + + align:start position:0% +what uh the current is in this bad cell +so the bad cell right here which is + + align:start position:0% +so the bad cell right here which is + + + align:start position:0% +so the bad cell right here which is +indicated by the the two arrows now + + align:start position:0% +indicated by the the two arrows now + + + align:start position:0% +indicated by the the two arrows now +instead of the four right this shaded + + align:start position:0% +instead of the four right this shaded + + + align:start position:0% +instead of the four right this shaded +cell right here is producing less + + align:start position:0% +cell right here is producing less + + + align:start position:0% +cell right here is producing less +current and so I know based on what + + align:start position:0% +current and so I know based on what + + + align:start position:0% +current and so I know based on what +we've talked about so far that the + + align:start position:0% +we've talked about so far that the + + + align:start position:0% +we've talked about so far that the +combined current output of the entire + + align:start position:0% +combined current output of the entire + + + align:start position:0% +combined current output of the entire +circuit is going to be approximately + + align:start position:0% +circuit is going to be approximately + + + align:start position:0% +circuit is going to be approximately +this one so hence you see a darker uh + + align:start position:0% +this one so hence you see a darker uh + + + align:start position:0% +this one so hence you see a darker uh +color represented the same color that's + + align:start position:0% +color represented the same color that's + + + align:start position:0% +color represented the same color that's +flowing through the + + align:start position:0% +flowing through the + + + align:start position:0% +flowing through the +cell so what happens to the large amount + + align:start position:0% +cell so what happens to the large amount + + + align:start position:0% +cell so what happens to the large amount +of current that's being generated inside + + align:start position:0% +of current that's being generated inside + + + align:start position:0% +of current that's being generated inside +of this one it's that cell still has the + + align:start position:0% +of this one it's that cell still has the + + + align:start position:0% +of this one it's that cell still has the +capacity to produce a large amount of + + align:start position:0% +capacity to produce a large amount of + + + align:start position:0% +capacity to produce a large amount of +current where is it going well some of + + align:start position:0% +current where is it going well some of + + + align:start position:0% +current where is it going well some of +that current is going through is is is + + align:start position:0% +that current is going through is is is + + + align:start position:0% +that current is going through is is is +going through the cell right here + + align:start position:0% +going through the cell right here + + + align:start position:0% +going through the cell right here +forward biasing it which would result in + + align:start position:0% +forward biasing it which would result in + + + align:start position:0% +forward biasing it which would result in +a negative bias or reverse bias of the + + align:start position:0% +a negative bias or reverse bias of the + + + align:start position:0% +a negative bias or reverse bias of the +bad cell because the uh the potential + + align:start position:0% +bad cell because the uh the potential + + + align:start position:0% +bad cell because the uh the potential +across this combined system still has to + + align:start position:0% +across this combined system still has to + + + align:start position:0% +across this combined system still has to +be zero you're in short circuit + + align:start position:0% +be zero you're in short circuit + + + align:start position:0% +be zero you're in short circuit +conditions so the potential here has to + + align:start position:0% +conditions so the potential here has to + + + align:start position:0% +conditions so the potential here has to +be equal to the potential there so what + + align:start position:0% +be equal to the potential there so what + + + align:start position:0% +be equal to the potential there so what +I've effectively done is I've reverse + + align:start position:0% +I've effectively done is I've reverse + + + align:start position:0% +I've effectively done is I've reverse +biased my bad + + align:start position:0% +biased my bad + + + align:start position:0% +biased my bad +cell and we'll get to why that's a + + align:start position:0% +cell and we'll get to why that's a + + + align:start position:0% +cell and we'll get to why that's a +problem later on those who are + + align:start position:0% +problem later on those who are + + + align:start position:0% +problem later on those who are +electrical engineers can already begin + + align:start position:0% +electrical engineers can already begin + + + align:start position:0% +electrical engineers can already begin +Conjuring up ideas of reverse bias + + align:start position:0% +Conjuring up ideas of reverse bias + + + align:start position:0% +Conjuring up ideas of reverse bias +breakdown but we'll get to uh we'll + + align:start position:0% +breakdown but we'll get to uh we'll + + + align:start position:0% +breakdown but we'll get to uh we'll +explain why it is why why reverse bias + + align:start position:0% +explain why it is why why reverse bias + + + align:start position:0% +explain why it is why why reverse bias +is bad in a few now if you had a series + + align:start position:0% +is bad in a few now if you had a series + + + align:start position:0% +is bad in a few now if you had a series +of these cells connected a bunch of + + align:start position:0% +of these cells connected a bunch of + + + align:start position:0% +of these cells connected a bunch of +these cells connected in series and they + + align:start position:0% +these cells connected in series and they + + + align:start position:0% +these cells connected in series and they +were all producing copious amounts of + + align:start position:0% +were all producing copious amounts of + + + align:start position:0% +were all producing copious amounts of +juice and you had One Bad Apple in your + + align:start position:0% +juice and you had One Bad Apple in your + + + align:start position:0% +juice and you had One Bad Apple in your +string you would be dumping a + + align:start position:0% +string you would be dumping a + + + align:start position:0% +string you would be dumping a +considerable amount of power across that + + align:start position:0% +considerable amount of power across that + + + align:start position:0% +considerable amount of power across that +or you could be dumping a considerable + + align:start position:0% +or you could be dumping a considerable + + + align:start position:0% +or you could be dumping a considerable +amount of power across that one cell and + + align:start position:0% +amount of power across that one cell and + + + align:start position:0% +amount of power across that one cell and +that's where um this graph right here + + align:start position:0% +that's where um this graph right here + + + align:start position:0% +that's where um this graph right here +comes from the power dissipated within + + align:start position:0% +comes from the power dissipated within + + + align:start position:0% +comes from the power dissipated within +the bad cell and that's a problem + + align:start position:0% +the bad cell and that's a problem + + + align:start position:0% +the bad cell and that's a problem +because if there's any weakness in the + + align:start position:0% +because if there's any weakness in the + + + align:start position:0% +because if there's any weakness in the +PN Junction of that bad cell and you're + + align:start position:0% +PN Junction of that bad cell and you're + + + align:start position:0% +PN Junction of that bad cell and you're +reverse biasing it you're going to be + + align:start position:0% +reverse biasing it you're going to be + + + align:start position:0% +reverse biasing it you're going to be +flooding a lot of current through that + + align:start position:0% +flooding a lot of current through that + + + align:start position:0% +flooding a lot of current through that +one little spot which means that that + + align:start position:0% +one little spot which means that that + + + align:start position:0% +one little spot which means that that +spot's going to heat up and it's going + + align:start position:0% +spot's going to heat up and it's going + + + align:start position:0% +spot's going to heat up and it's going +to form a hot spot which has the + + align:start position:0% +to form a hot spot which has the + + + align:start position:0% +to form a hot spot which has the +potential to get very hot and we know + + align:start position:0% +potential to get very hot and we know + + + align:start position:0% +potential to get very hot and we know +that the encapsulant materials flow at + + align:start position:0% +that the encapsulant materials flow at + + + align:start position:0% +that the encapsulant materials flow at +around 150 to 175 C and some other + + align:start position:0% +around 150 to 175 C and some other + + + align:start position:0% +around 150 to 175 C and some other +material failures can occur above that + + align:start position:0% +material failures can occur above that + + + align:start position:0% +material failures can occur above that +so um hot spots are bad um if you + + align:start position:0% +so um hot spots are bad um if you + + + align:start position:0% +so um hot spots are bad um if you +reverse bias your devices um you can + + align:start position:0% +reverse bias your devices um you can + + + align:start position:0% +reverse bias your devices um you can +enter what's called a breakdown regime + + align:start position:0% +enter what's called a breakdown regime + + + align:start position:0% +enter what's called a breakdown regime +uh that essentially is is is is driven + + align:start position:0% +uh that essentially is is is is driven + + + align:start position:0% +uh that essentially is is is is driven +often times in a real solar cell by + + align:start position:0% +often times in a real solar cell by + + + align:start position:0% +often times in a real solar cell by +isolated points in your say weaknesses + + align:start position:0% +isolated points in your say weaknesses + + + align:start position:0% +isolated points in your say weaknesses +in the PN Junction where current is + + align:start position:0% +in the PN Junction where current is + + + align:start position:0% +in the PN Junction where current is +going to flow and that leads to the + + align:start position:0% +going to flow and that leads to the + + + align:start position:0% +going to flow and that leads to the +Hotpot failure I just mentioned here's + + align:start position:0% +Hotpot failure I just mentioned here's + + + align:start position:0% +Hotpot failure I just mentioned here's +um thermographic Imaging not using the + + align:start position:0% +um thermographic Imaging not using the + + + align:start position:0% +um thermographic Imaging not using the +fancy camera that we have downstairs + + align:start position:0% +fancy camera that we have downstairs + + + align:start position:0% +fancy camera that we have downstairs +using a much + + align:start position:0% +using a much + + + align:start position:0% +using a much +simpler camera out in the field lower + + align:start position:0% +simpler camera out in the field lower + + + align:start position:0% +simpler camera out in the field lower +cost it's uh these are high enough + + align:start position:0% +cost it's uh these are high enough + + + align:start position:0% +cost it's uh these are high enough +temperature variances to be able to + + align:start position:0% +temperature variances to be able to + + + align:start position:0% +temperature variances to be able to +detect using pretty low tech technology + + align:start position:0% +detect using pretty low tech technology + + + align:start position:0% +detect using pretty low tech technology +it's not a small amount of current going + + align:start position:0% +it's not a small amount of current going + + + align:start position:0% +it's not a small amount of current going +through a solar cell these are large + + align:start position:0% +through a solar cell these are large + + + align:start position:0% +through a solar cell these are large +massive amounts of current going through + + align:start position:0% +massive amounts of current going through + + + align:start position:0% +massive amounts of current going through +defective cells in the field and so you + + align:start position:0% +defective cells in the field and so you + + + align:start position:0% +defective cells in the field and so you +can use these um you can use these + + align:start position:0% +can use these um you can use these + + + align:start position:0% +can use these um you can use these +cameras to visualize the underperforming + + align:start position:0% +cameras to visualize the underperforming + + + align:start position:0% +cameras to visualize the underperforming +cells inside of modules and that's + + align:start position:0% +cells inside of modules and that's + + + align:start position:0% +cells inside of modules and that's +pretty + + align:start position:0% + + + + align:start position:0% + +nifty all right so we planted that flag + + align:start position:0% +nifty all right so we planted that flag + + + align:start position:0% +nifty all right so we planted that flag +and let's come back to it um we're going + + align:start position:0% +and let's come back to it um we're going + + + align:start position:0% +and let's come back to it um we're going +to describe how microinverters and micro + + align:start position:0% +to describe how microinverters and micro + + + align:start position:0% +to describe how microinverters and micro +Electronics can improve module + + align:start position:0% +Electronics can improve module + + + align:start position:0% +Electronics can improve module +performance output um even if you didn't + + align:start position:0% +performance output um even if you didn't + + + align:start position:0% +performance output um even if you didn't +follow all the detail of the explanation + + align:start position:0% +follow all the detail of the explanation + + + align:start position:0% +follow all the detail of the explanation +until now you can appreciate the fact + + align:start position:0% +until now you can appreciate the fact + + + align:start position:0% +until now you can appreciate the fact +that a bad apple a bad solar cell uh + + align:start position:0% +that a bad apple a bad solar cell uh + + + align:start position:0% +that a bad apple a bad solar cell uh +connected in series or in parallel with + + align:start position:0% +connected in series or in parallel with + + + align:start position:0% +connected in series or in parallel with +the rest of them can cause the combined + + align:start position:0% +the rest of them can cause the combined + + + align:start position:0% +the rest of them can cause the combined +output of the module to be lower and so + + align:start position:0% +output of the module to be lower and so + + + align:start position:0% +output of the module to be lower and so +we're going to talk about how + + align:start position:0% +we're going to talk about how + + + align:start position:0% +we're going to talk about how +microelectronics and eventually + + align:start position:0% +microelectronics and eventually + + + align:start position:0% +microelectronics and eventually +microinverters can help resolve that + + align:start position:0% +microinverters can help resolve that + + + align:start position:0% +microinverters can help resolve that +either on a cell level or on a larger + + align:start position:0% +either on a cell level or on a larger + + + align:start position:0% +either on a cell level or on a larger +modu to module level the simple + + align:start position:0% +modu to module level the simple + + + align:start position:0% +modu to module level the simple +principle of a bypass diode of a cell is + + align:start position:0% +principle of a bypass diode of a cell is + + + align:start position:0% +principle of a bypass diode of a cell is +this if if the if the reverse bias + + align:start position:0% +this if if the if the reverse bias + + + align:start position:0% +this if if the if the reverse bias +current comes too large instead of + + align:start position:0% +current comes too large instead of + + + align:start position:0% +current comes too large instead of +forcing the current to flow through the + + align:start position:0% +forcing the current to flow through the + + + align:start position:0% +forcing the current to flow through the +bad cell you can force it to flow around + + align:start position:0% +bad cell you can force it to flow around + + + align:start position:0% +bad cell you can force it to flow around +um a bypass diode and therefore it it it + + align:start position:0% +um a bypass diode and therefore it it it + + + align:start position:0% +um a bypass diode and therefore it it it +it it short circuits it leaves a cell + + align:start position:0% +it it short circuits it leaves a cell + + + align:start position:0% +it it short circuits it leaves a cell +out of the circuit right the the current + + align:start position:0% +out of the circuit right the the current + + + align:start position:0% +out of the circuit right the the current +is Flowing around it and so you result + + align:start position:0% +is Flowing around it and so you result + + + align:start position:0% +is Flowing around it and so you result +in less of a degradation of your module + + align:start position:0% +in less of a degradation of your module + + + align:start position:0% +in less of a degradation of your module +to put it uh from an equivalent IV curve + + align:start position:0% +to put it uh from an equivalent IV curve + + + align:start position:0% +to put it uh from an equivalent IV curve +perspective instead of adding this IV + + align:start position:0% +perspective instead of adding this IV + + + align:start position:0% +perspective instead of adding this IV +curve here with the rest of them you're + + align:start position:0% +curve here with the rest of them you're + + + align:start position:0% +curve here with the rest of them you're +simply moving the current around it so + + align:start position:0% +simply moving the current around it so + + + align:start position:0% +simply moving the current around it so +you'd have the end good cells and and + + align:start position:0% +you'd have the end good cells and and + + + align:start position:0% +you'd have the end good cells and and +that's it end of story the 10th cell + + align:start position:0% +that's it end of story the 10th cell + + + align:start position:0% +that's it end of story the 10th cell +would just be taken out of your circuit + + align:start position:0% +would just be taken out of your circuit + + + align:start position:0% +would just be taken out of your circuit +it would be pushed + + align:start position:0% +it would be pushed + + + align:start position:0% +it would be pushed +aside okay so uh on a cell level that + + align:start position:0% +aside okay so uh on a cell level that + + + align:start position:0% +aside okay so uh on a cell level that +makes sense + + align:start position:0% +makes sense + + + align:start position:0% +makes sense +um skip over a couple of these I think + + align:start position:0% +um skip over a couple of these I think + + + align:start position:0% +um skip over a couple of these I think +on a module level as well it can make a + + align:start position:0% +on a module level as well it can make a + + + align:start position:0% +on a module level as well it can make a +lot of sense and here it it really does + + align:start position:0% +lot of sense and here it it really does + + + align:start position:0% +lot of sense and here it it really does +because you're um the uh shading losses + + align:start position:0% +because you're um the uh shading losses + + + align:start position:0% +because you're um the uh shading losses +on a module level tend to be more severe + + align:start position:0% +on a module level tend to be more severe + + + align:start position:0% +on a module level tend to be more severe +you could have for example a tree in the + + align:start position:0% +you could have for example a tree in the + + + align:start position:0% +you could have for example a tree in the +wrong place or a telephone pole + + align:start position:0% +wrong place or a telephone pole + + + align:start position:0% +wrong place or a telephone pole +somewhere uh shading one particular + + align:start position:0% +somewhere uh shading one particular + + + align:start position:0% +somewhere uh shading one particular +module in an array an array of modules + + align:start position:0% +module in an array an array of modules + + + align:start position:0% +module in an array an array of modules +on my roof for example there are 12 + + align:start position:0% +on my roof for example there are 12 + + + align:start position:0% +on my roof for example there are 12 +sharp 187 right so if you have uh a + + align:start position:0% +sharp 187 right so if you have uh a + + + align:start position:0% +sharp 187 right so if you have uh a +series of these modules up on the roof + + align:start position:0% +series of these modules up on the roof + + + align:start position:0% +series of these modules up on the roof +um you can cause the current to + + align:start position:0% +um you can cause the current to + + + align:start position:0% +um you can cause the current to +circumvent one of the modules that's + + align:start position:0% +circumvent one of the modules that's + + + align:start position:0% +circumvent one of the modules that's +underperforming again using the bypass + + align:start position:0% +underperforming again using the bypass + + + align:start position:0% +underperforming again using the bypass +diodes and those are fairly standard in + + align:start position:0% +diodes and those are fairly standard in + + + align:start position:0% +diodes and those are fairly standard in +most of the junction boxes so inside of + + align:start position:0% +most of the junction boxes so inside of + + + align:start position:0% +most of the junction boxes so inside of +here there is uh some very simple + + align:start position:0% +here there is uh some very simple + + + align:start position:0% +here there is uh some very simple +Electronics to prevent uh the modules + + align:start position:0% +Electronics to prevent uh the modules + + + align:start position:0% +Electronics to prevent uh the modules +from becoming power syns and perhaps + + align:start position:0% +from becoming power syns and perhaps + + + align:start position:0% +from becoming power syns and perhaps +even drawing power from the + + align:start position:0% + + + + align:start position:0% + +grid + + align:start position:0% + + + + align:start position:0% + +okay um okay so uh + + align:start position:0% +okay um okay so uh + + + align:start position:0% +okay um okay so uh +microinverters some people say well + + align:start position:0% +microinverters some people say well + + + align:start position:0% +microinverters some people say well +instead of just managing power on a DC + + align:start position:0% +instead of just managing power on a DC + + + align:start position:0% +instead of just managing power on a DC +basis and either dealing with the + + align:start position:0% +basis and either dealing with the + + + align:start position:0% +basis and either dealing with the +mismatch loss or cutting bad apples out + + align:start position:0% +mismatch loss or cutting bad apples out + + + align:start position:0% +mismatch loss or cutting bad apples out +of the circuit altogether let's do + + align:start position:0% +of the circuit altogether let's do + + + align:start position:0% +of the circuit altogether let's do +something even better let's try to to + + align:start position:0% +something even better let's try to to + + + align:start position:0% +something even better let's try to to +put this in in in uh childhood education + + align:start position:0% +put this in in in uh childhood education + + + align:start position:0% +put this in in in uh childhood education +terms let's let every module perform up + + align:start position:0% +terms let's let every module perform up + + + align:start position:0% +terms let's let every module perform up +to their most to the greatest potential + + align:start position:0% +to their most to the greatest potential + + + align:start position:0% +to their most to the greatest potential +and then everybody is happy right so + + align:start position:0% +and then everybody is happy right so + + + align:start position:0% +and then everybody is happy right so +we're going to convert the power + + align:start position:0% +we're going to convert the power + + + align:start position:0% +we're going to convert the power +directly on the back of the module into + + align:start position:0% +directly on the back of the module into + + + align:start position:0% +directly on the back of the module into +AC alternating current and then we're + + align:start position:0% +AC alternating current and then we're + + + align:start position:0% +AC alternating current and then we're +going to use Electronics from there to + + align:start position:0% +going to use Electronics from there to + + + align:start position:0% +going to use Electronics from there to +essentially add the add the uh uh + + align:start position:0% +essentially add the add the uh uh + + + align:start position:0% +essentially add the add the uh uh +currents together once we have defined + + align:start position:0% +currents together once we have defined + + + align:start position:0% +currents together once we have defined +the voltage at 120 volts at alternating + + align:start position:0% +the voltage at 120 volts at alternating + + + align:start position:0% +the voltage at 120 volts at alternating +current and uh and the advantage of that + + align:start position:0% +current and uh and the advantage of that + + + align:start position:0% +current and uh and the advantage of that +is that if something if one module is + + align:start position:0% +is that if something if one module is + + + align:start position:0% +is that if something if one module is +underperforming instead of contri zero + + align:start position:0% +underperforming instead of contri zero + + + align:start position:0% +underperforming instead of contri zero +it's now contributing some fraction if + + align:start position:0% +it's now contributing some fraction if + + + align:start position:0% +it's now contributing some fraction if +the mismatch was small enough not to + + align:start position:0% +the mismatch was small enough not to + + + align:start position:0% +the mismatch was small enough not to +trip any of the bypass diodes but still + + align:start position:0% +trip any of the bypass diodes but still + + + align:start position:0% +trip any of the bypass diodes but still +degrade the power of the overall system + + align:start position:0% +degrade the power of the overall system + + + align:start position:0% +degrade the power of the overall system +now you're able to recover you're able + + align:start position:0% +now you're able to recover you're able + + + align:start position:0% +now you're able to recover you're able +to allow that good module to perform up + + align:start position:0% +to allow that good module to perform up + + + align:start position:0% +to allow that good module to perform up +to its true potential instead of being + + align:start position:0% +to its true potential instead of being + + + align:start position:0% +to its true potential instead of being +dragged down by the others and so the + + align:start position:0% +dragged down by the others and so the + + + align:start position:0% +dragged down by the others and so the +microinverter companies that are uh + + align:start position:0% +microinverter companies that are uh + + + align:start position:0% +microinverter companies that are uh +proposing and and actually marketing and + + align:start position:0% +proposing and and actually marketing and + + + align:start position:0% +proposing and and actually marketing and +selling modules that apply the + + align:start position:0% +selling modules that apply the + + + align:start position:0% +selling modules that apply the +electronics directly in the back of the + + align:start position:0% +electronics directly in the back of the + + + align:start position:0% +electronics directly in the back of the +solar panels have the advantage of being + + align:start position:0% +solar panels have the advantage of being + + + align:start position:0% +solar panels have the advantage of being +able to eek out several additional + + align:start position:0% +able to eek out several additional + + + align:start position:0% +able to eek out several additional +percent of total power from the from the + + align:start position:0% +percent of total power from the from the + + + align:start position:0% +percent of total power from the from the +array from the system the disadvantage + + align:start position:0% +array from the system the disadvantage + + + align:start position:0% +array from the system the disadvantage +of Distributing these microinverter + + align:start position:0% +of Distributing these microinverter + + + align:start position:0% +of Distributing these microinverter +components over every single module + + align:start position:0% +components over every single module + + + align:start position:0% +components over every single module +is a lot of them cost money you have to + + align:start position:0% +is a lot of them cost money you have to + + + align:start position:0% +is a lot of them cost money you have to +make a lot of them they cost money + + align:start position:0% +make a lot of them they cost money + + + align:start position:0% +make a lot of them they cost money +they're costly and meantime between + + align:start position:0% +they're costly and meantime between + + + align:start position:0% +they're costly and meantime between +failures increases right potentially + + align:start position:0% +failures increases right potentially + + + align:start position:0% +failures increases right potentially +potentially um so if you if you have an + + align:start position:0% +potentially um so if you if you have an + + + align:start position:0% +potentially um so if you if you have an +inverter how many people know how long + + align:start position:0% +inverter how many people know how long + + + align:start position:0% +inverter how many people know how long +an inverter lasts before it needs to be + + align:start position:0% +an inverter lasts before it needs to be + + + align:start position:0% +an inverter lasts before it needs to be +replaced + + align:start position:0% +replaced + + + align:start position:0% +replaced +typically five to 10 years now it's it's + + align:start position:0% +typically five to 10 years now it's it's + + + align:start position:0% +typically five to 10 years now it's it's +up to say 7 to 12 but yeah somewhere in + + align:start position:0% +up to say 7 to 12 but yeah somewhere in + + + align:start position:0% +up to say 7 to 12 but yeah somewhere in +that range less than the 20 to 30 year + + align:start position:0% +that range less than the 20 to 30 year + + + align:start position:0% +that range less than the 20 to 30 year +LIF of your of your array and so now if + + align:start position:0% +LIF of your of your array and so now if + + + align:start position:0% +LIF of your of your array and so now if +you have these distributed little + + align:start position:0% +you have these distributed little + + + align:start position:0% +you have these distributed little +inverters across every solar panel uh + + align:start position:0% +inverters across every solar panel uh + + + align:start position:0% +inverters across every solar panel uh +and they Fizz out after a certain amount + + align:start position:0% +and they Fizz out after a certain amount + + + align:start position:0% +and they Fizz out after a certain amount +of time you have to go somebody has to + + align:start position:0% +of time you have to go somebody has to + + + align:start position:0% +of time you have to go somebody has to +go up there and replace them first + + align:start position:0% +go up there and replace them first + + + align:start position:0% +go up there and replace them first +identify where they where they went down + + align:start position:0% +identify where they where they went down + + + align:start position:0% +identify where they where they went down +and then replace them so microinverter + + align:start position:0% +and then replace them so microinverter + + + align:start position:0% +and then replace them so microinverter +longevity is an important part of + + align:start position:0% +longevity is an important part of + + + align:start position:0% +longevity is an important part of +reducing risk and marketing inverters so + + align:start position:0% +reducing risk and marketing inverters so + + + align:start position:0% +reducing risk and marketing inverters so +the microinverter community is helping + + align:start position:0% +the microinverter community is helping + + + align:start position:0% +the microinverter community is helping +to push or improve the quality of + + align:start position:0% +to push or improve the quality of + + + align:start position:0% +to push or improve the quality of +inverters over the entire solar Spectrum + + align:start position:0% +inverters over the entire solar Spectrum + + + align:start position:0% +inverters over the entire solar Spectrum +which is kind of cool yeah what's + + align:start position:0% + + + + align:start position:0% + +the um + + align:start position:0% +the um + + + align:start position:0% +the um +so my understanding from reie Ram who's + + align:start position:0% +so my understanding from reie Ram who's + + + align:start position:0% +so my understanding from reie Ram who's +actually down in in arpa right now um + + align:start position:0% +actually down in in arpa right now um + + + align:start position:0% +actually down in in arpa right now um +he's a professor at MIT who's been been + + align:start position:0% +he's a professor at MIT who's been been + + + align:start position:0% +he's a professor at MIT who's been been +assisting uh the doe over the past + + align:start position:0% +assisting uh the doe over the past + + + align:start position:0% +assisting uh the doe over the past +couple of years um many uh most failure + + align:start position:0% +couple of years um many uh most failure + + + align:start position:0% +couple of years um many uh most failure +and inverters relates to the Power + + align:start position:0% +and inverters relates to the Power + + + align:start position:0% +and inverters relates to the Power +Electronics itself and the high-speed + + align:start position:0% +Electronics itself and the high-speed + + + align:start position:0% +Electronics itself and the high-speed +switchers that are used that's my + + align:start position:0% +switchers that are used that's my + + + align:start position:0% +switchers that are used that's my +understanding um I could uh I could look + + align:start position:0% +understanding um I could uh I could look + + + align:start position:0% +understanding um I could uh I could look +into that a little bit more and get you + + align:start position:0% +into that a little bit more and get you + + + align:start position:0% +into that a little bit more and get you +more details about precise inverter + + align:start position:0% +more details about precise inverter + + + align:start position:0% +more details about precise inverter +failure modes uh but uh that is that is + + align:start position:0% +failure modes uh but uh that is that is + + + align:start position:0% +failure modes uh but uh that is that is +my rudimentary understanding from + + align:start position:0% +my rudimentary understanding from + + + align:start position:0% +my rudimentary understanding from +discussions with him + + align:start position:0% + + + + align:start position:0% + +um sorry my screen is still cracked it's + + align:start position:0% +um sorry my screen is still cracked it's + + + align:start position:0% +um sorry my screen is still cracked it's +going to be fixed tonight um advantages + + align:start position:0% +going to be fixed tonight um advantages + + + align:start position:0% +going to be fixed tonight um advantages +of integrated Power Electronics maximum + + align:start position:0% +of integrated Power Electronics maximum + + + align:start position:0% +of integrated Power Electronics maximum +PowerPoint tracking disadvantages okay + + align:start position:0% +PowerPoint tracking disadvantages okay + + + align:start position:0% +PowerPoint tracking disadvantages okay +yeah okay and so it's it's still a + + align:start position:0% +yeah okay and so it's it's still a + + + align:start position:0% +yeah okay and so it's it's still a +relatively Hot Topic there there was an + + align:start position:0% +relatively Hot Topic there there was an + + + align:start position:0% +relatively Hot Topic there there was an +RPA call uh for improved Power + + align:start position:0% +RPA call uh for improved Power + + + align:start position:0% +RPA call uh for improved Power +Electronics across uh solar and other + + align:start position:0% +Electronics across uh solar and other + + + align:start position:0% +Electronics across uh solar and other +Industries um and there is some + + align:start position:0% +Industries um and there is some + + + align:start position:0% +Industries um and there is some +discussion in the PV Community as to how + + align:start position:0% +discussion in the PV Community as to how + + + align:start position:0% +discussion in the PV Community as to how +much to adopt this new technology + + align:start position:0% +much to adopt this new technology + + + align:start position:0% +much to adopt this new technology +especially in residential systems so + + align:start position:0% +especially in residential systems so + + + align:start position:0% +especially in residential systems so +Trends um in in installations in general + + align:start position:0% +Trends um in in installations in general + + + align:start position:0% +Trends um in in installations in general +uh in the past um installations were uh + + align:start position:0% +uh in the past um installations were uh + + + align:start position:0% +uh in the past um installations were uh +heavily labor intensive uh there is now + + align:start position:0% +heavily labor intensive uh there is now + + + align:start position:0% +heavily labor intensive uh there is now +a large amount of pre-assembly done + + align:start position:0% +a large amount of pre-assembly done + + + align:start position:0% +a large amount of pre-assembly done +before the modules hit the roof uh but + + align:start position:0% +before the modules hit the roof uh but + + + align:start position:0% +before the modules hit the roof uh but +there's still a sizable number of + + align:start position:0% +there's still a sizable number of + + + align:start position:0% +there's still a sizable number of +components that go into every single + + align:start position:0% +components that go into every single + + + align:start position:0% +components that go into every single +solar module and um that takes time to + + align:start position:0% +solar module and um that takes time to + + + align:start position:0% +solar module and um that takes time to +mount everything out there in the field + + align:start position:0% +mount everything out there in the field + + + align:start position:0% +mount everything out there in the field +uh so what are some other you know what + + align:start position:0% +uh so what are some other you know what + + + align:start position:0% +uh so what are some other you know what +is what is the the dream of any solar uh + + align:start position:0% +is what is the the dream of any solar uh + + + align:start position:0% +is what is the the dream of any solar uh +installer is to get this roll of + + align:start position:0% +installer is to get this roll of + + + align:start position:0% +installer is to get this roll of +material that just unrolls unfurls onto + + align:start position:0% +material that just unrolls unfurls onto + + + align:start position:0% +material that just unrolls unfurls onto +the roof and using a staple gun bang + + align:start position:0% +the roof and using a staple gun bang + + + align:start position:0% +the roof and using a staple gun bang +bang bang bang bang or a nail gun + + align:start position:0% +bang bang bang bang or a nail gun + + + align:start position:0% +bang bang bang bang or a nail gun +everything is is is locked down it's + + align:start position:0% +everything is is is locked down it's + + + align:start position:0% +everything is is is locked down it's +lightweight it doesn't underperform when + + align:start position:0% +lightweight it doesn't underperform when + + + align:start position:0% +lightweight it doesn't underperform when +um when uh it it gets too warm uh these + + align:start position:0% +um when uh it it gets too warm uh these + + + align:start position:0% +um when uh it it gets too warm uh these +are all the specs that would constitute + + align:start position:0% +are all the specs that would constitute + + + align:start position:0% +are all the specs that would constitute +say an ideal solar module we don't get + + align:start position:0% +say an ideal solar module we don't get + + + align:start position:0% +say an ideal solar module we don't get +that lucky we have to make compromises + + align:start position:0% +that lucky we have to make compromises + + + align:start position:0% +that lucky we have to make compromises +in reality and um say for example on my + + align:start position:0% +in reality and um say for example on my + + + align:start position:0% +in reality and um say for example on my +roof there was a soft spot on the roof + + align:start position:0% +roof there was a soft spot on the roof + + + align:start position:0% +roof there was a soft spot on the roof +that had to be worked around uh the + + align:start position:0% +that had to be worked around uh the + + + align:start position:0% +that had to be worked around uh the +structur engineer had to be called back + + align:start position:0% +structur engineer had to be called back + + + align:start position:0% +structur engineer had to be called back +and evaluate and figure out whether or + + align:start position:0% +and evaluate and figure out whether or + + + align:start position:0% +and evaluate and figure out whether or +not it needed reinforcement and so forth + + align:start position:0% +not it needed reinforcement and so forth + + + align:start position:0% +not it needed reinforcement and so forth +so we're we're we're still far away in + + align:start position:0% +so we're we're we're still far away in + + + align:start position:0% +so we're we're we're still far away in +terms of where we need to be for solar + + align:start position:0% +terms of where we need to be for solar + + + align:start position:0% +terms of where we need to be for solar +installations to really be uh truly low + + align:start position:0% +installations to really be uh truly low + + + align:start position:0% +installations to really be uh truly low +cost uh and a lot of it has to do with + + align:start position:0% +cost uh and a lot of it has to do with + + + align:start position:0% +cost uh and a lot of it has to do with +the balance of system + + align:start position:0% +the balance of system + + + align:start position:0% +the balance of system +design um so I I mentioned a few + + align:start position:0% +design um so I I mentioned a few + + + align:start position:0% +design um so I I mentioned a few +companies are are attempting to uh + + align:start position:0% +companies are are attempting to uh + + + align:start position:0% +companies are are attempting to uh +integrate the the connections into this + + align:start position:0% +integrate the the connections into this + + + align:start position:0% +integrate the the connections into this +fasile click uh uh lock mechanism um + + align:start position:0% +fasile click uh uh lock mechanism um + + + align:start position:0% +fasile click uh uh lock mechanism um +there have been patents filed I think + + align:start position:0% +there have been patents filed I think + + + align:start position:0% +there have been patents filed I think +since the 1990s on this probably even + + align:start position:0% +since the 1990s on this probably even + + + align:start position:0% +since the 1990s on this probably even +earlier um more recently uh some + + align:start position:0% +earlier um more recently uh some + + + align:start position:0% +earlier um more recently uh some +companies have marketed a product in + + align:start position:0% +companies have marketed a product in + + + align:start position:0% +companies have marketed a product in +this regard and of course that increases + + align:start position:0% +this regard and of course that increases + + + align:start position:0% +this regard and of course that increases +the uh the facility of installation + + align:start position:0% +the uh the facility of installation + + + align:start position:0% +the uh the facility of installation +there's even a few that are selling uh I + + align:start position:0% +there's even a few that are selling uh I + + + align:start position:0% +there's even a few that are selling uh I +think it was a keynet lows and uh for a + + align:start position:0% +think it was a keynet lows and uh for a + + + align:start position:0% +think it was a keynet lows and uh for a +Time BP Solar was selling at Home Depot + + align:start position:0% +Time BP Solar was selling at Home Depot + + + align:start position:0% +Time BP Solar was selling at Home Depot +uh there are examples of companies + + align:start position:0% +uh there are examples of companies + + + align:start position:0% +uh there are examples of companies +beginning to Market their product at + + align:start position:0% +beginning to Market their product at + + + align:start position:0% +beginning to Market their product at +hardware stores question could youing + + align:start position:0% +hardware stores question could youing + + + align:start position:0% +hardware stores question could youing +included in balance of systems yes so + + align:start position:0% +included in balance of systems yes so + + + align:start position:0% +included in balance of systems yes so +balance of systems um is defined as + + align:start position:0% +balance of systems um is defined as + + + align:start position:0% +balance of systems um is defined as +everything beyond the module so that + + align:start position:0% +everything beyond the module so that + + + align:start position:0% +everything beyond the module so that +would include the wiring the the framing + + align:start position:0% +would include the wiring the the framing + + + align:start position:0% +would include the wiring the the framing +the racking the inverter um yes that + + align:start position:0% +the racking the inverter um yes that + + + align:start position:0% +the racking the inverter um yes that +that is that is balance of systems + + align:start position:0% +that is that is balance of systems + + + align:start position:0% +that is that is balance of systems +excellent question excellent + + align:start position:0% +excellent question excellent + + + align:start position:0% +excellent question excellent +question so um we're going to talk about + + align:start position:0% +question so um we're going to talk about + + + align:start position:0% +question so um we're going to talk about +some of the tests that the PB module + + align:start position:0% +some of the tests that the PB module + + + align:start position:0% +some of the tests that the PB module +must pass to ensure reliable + + align:start position:0% +must pass to ensure reliable + + + align:start position:0% +must pass to ensure reliable +multi-decade service life in the field + + align:start position:0% +multi-decade service life in the field + + + align:start position:0% +multi-decade service life in the field +and some of the shortcomings of the + + align:start position:0% +and some of the shortcomings of the + + + align:start position:0% +and some of the shortcomings of the +tests uh I'm going to motivate this by + + align:start position:0% +tests uh I'm going to motivate this by + + + align:start position:0% +tests uh I'm going to motivate this by +saying um uh there's there's reason to + + align:start position:0% +saying um uh there's there's reason to + + + align:start position:0% +saying um uh there's there's reason to +be concerned uh in the early days of the + + align:start position:0% +be concerned uh in the early days of the + + + align:start position:0% +be concerned uh in the early days of the +indust indry about performance and + + align:start position:0% +indust indry about performance and + + + align:start position:0% +indust indry about performance and +reliability this was a study done by + + align:start position:0% +reliability this was a study done by + + + align:start position:0% +reliability this was a study done by +Arie Jacobson uh the group that's + + align:start position:0% +Arie Jacobson uh the group that's + + + align:start position:0% +Arie Jacobson uh the group that's +working with the World Bank will be as + + align:start position:0% +working with the World Bank will be as + + + align:start position:0% +working with the World Bank will be as +well working with Arie Jacobson uh on + + align:start position:0% +well working with Arie Jacobson uh on + + + align:start position:0% +well working with Arie Jacobson uh on +their class project uh he's a professor + + align:start position:0% +their class project uh he's a professor + + + align:start position:0% +their class project uh he's a professor +at hul University in California uh + + align:start position:0% +at hul University in California uh + + + align:start position:0% +at hul University in California uh +during his PhD with Dan camon and + + align:start position:0% +during his PhD with Dan camon and + + + align:start position:0% +during his PhD with Dan camon and +Berkeley uh he did an audit of rated + + align:start position:0% +Berkeley uh he did an audit of rated + + + align:start position:0% +Berkeley uh he did an audit of rated +versus actual power outputs of solar + + align:start position:0% +versus actual power outputs of solar + + + align:start position:0% +versus actual power outputs of solar +modules in the field of Kenya in Africa + + align:start position:0% +modules in the field of Kenya in Africa + + + align:start position:0% +modules in the field of Kenya in Africa +and found uh rather large discrepancy + + align:start position:0% +and found uh rather large discrepancy + + + align:start position:0% +and found uh rather large discrepancy +between what was promised and what was + + align:start position:0% +between what was promised and what was + + + align:start position:0% +between what was promised and what was +actually delivered this is a great + + align:start position:0% +actually delivered this is a great + + + align:start position:0% +actually delivered this is a great +example of um field work being done good + + align:start position:0% +example of um field work being done good + + + align:start position:0% +example of um field work being done good +old-fashioned detective work that leads + + align:start position:0% +old-fashioned detective work that leads + + + align:start position:0% +old-fashioned detective work that leads +to changes in the industry um that got a + + align:start position:0% +to changes in the industry um that got a + + + align:start position:0% +to changes in the industry um that got a +number of the underperformers to improve + + align:start position:0% +number of the underperformers to improve + + + align:start position:0% +number of the underperformers to improve +their their product so I I mentioned uh + + align:start position:0% +their their product so I I mentioned uh + + + align:start position:0% +their their product so I I mentioned uh +you know there there was there's a + + align:start position:0% +you know there there was there's a + + + align:start position:0% +you know there there was there's a +question of of the customer am I getting + + align:start position:0% +question of of the customer am I getting + + + align:start position:0% +question of of the customer am I getting +the real value that I've been promised + + align:start position:0% +the real value that I've been promised + + + align:start position:0% +the real value that I've been promised +uh especially in the absence of + + align:start position:0% +uh especially in the absence of + + + align:start position:0% +uh especially in the absence of +independent monitoring if you're not + + align:start position:0% +independent monitoring if you're not + + + align:start position:0% +independent monitoring if you're not +actively measuring the power output and + + align:start position:0% +actively measuring the power output and + + + align:start position:0% +actively measuring the power output and +recording it um there's always that + + align:start position:0% +recording it um there's always that + + + align:start position:0% +recording it um there's always that +question lingering so module testing and + + align:start position:0% +question lingering so module testing and + + + align:start position:0% +question lingering so module testing and +reliability is is meant to ensure + + align:start position:0% +reliability is is meant to ensure + + + align:start position:0% +reliability is is meant to ensure +product quality and output quality + + align:start position:0% +product quality and output quality + + + align:start position:0% +product quality and output quality +secondly it's safety I mentioned these + + align:start position:0% +secondly it's safety I mentioned these + + + align:start position:0% +secondly it's safety I mentioned these +thermographic cameras this is an example + + align:start position:0% +thermographic cameras this is an example + + + align:start position:0% +thermographic cameras this is an example +on an array of you know Hot Spot it's + + align:start position:0% +on an array of you know Hot Spot it's + + + align:start position:0% +on an array of you know Hot Spot it's +not too hot right now it's 36 degrees or + + align:start position:0% +not too hot right now it's 36 degrees or + + + align:start position:0% +not too hot right now it's 36 degrees or +so but everything else is down around 15 + + align:start position:0% +so but everything else is down around 15 + + + align:start position:0% +so but everything else is down around 15 +if you imagine this being on a sunny day + + align:start position:0% +if you imagine this being on a sunny day + + + align:start position:0% +if you imagine this being on a sunny day +um a really sunny day this could uh this + + align:start position:0% +um a really sunny day this could uh this + + + align:start position:0% +um a really sunny day this could uh this +hot spot potentially could be getting up + + align:start position:0% +hot spot potentially could be getting up + + + align:start position:0% +hot spot potentially could be getting up +uh much higher uh so that's obviously of + + align:start position:0% +uh much higher uh so that's obviously of + + + align:start position:0% +uh much higher uh so that's obviously of +concern and um there's as well uh + + align:start position:0% +concern and um there's as well uh + + + align:start position:0% +concern and um there's as well uh +hotspots or or or heat that can be + + align:start position:0% +hotspots or or or heat that can be + + + align:start position:0% +hotspots or or or heat that can be +generated from the junction box on on + + align:start position:0% +generated from the junction box on on + + + align:start position:0% +generated from the junction box on on +the back um this contains a fair amount + + align:start position:0% +the back um this contains a fair amount + + + align:start position:0% +the back um this contains a fair amount +of electronics again and if there is uh + + align:start position:0% +of electronics again and if there is uh + + + align:start position:0% +of electronics again and if there is uh +some failure of the electronics inside + + align:start position:0% +some failure of the electronics inside + + + align:start position:0% +some failure of the electronics inside +of here you could have the combined + + align:start position:0% +of here you could have the combined + + + align:start position:0% +of here you could have the combined +power output of the entire module arcing + + align:start position:0% +power output of the entire module arcing + + + align:start position:0% +power output of the entire module arcing +right through a given component back + + align:start position:0% +right through a given component back + + + align:start position:0% +right through a given component back +here causing Sparks to fly and this is + + align:start position:0% +here causing Sparks to fly and this is + + + align:start position:0% +here causing Sparks to fly and this is +where this Photon International article + + align:start position:0% +where this Photon International article + + + align:start position:0% +where this Photon International article +from 2009 comes in where um they say uh + + align:start position:0% +from 2009 comes in where um they say uh + + + align:start position:0% +from 2009 comes in where um they say uh +it's extremely important the upshot of + + align:start position:0% +it's extremely important the upshot of + + + align:start position:0% +it's extremely important the upshot of +the entire article I I gave it to you in + + align:start position:0% +the entire article I I gave it to you in + + + align:start position:0% +the entire article I I gave it to you in +its entirety but the upshot is + + align:start position:0% +its entirety but the upshot is + + + align:start position:0% +its entirety but the upshot is +let's not play with fire meaning let's + + align:start position:0% +let's not play with fire meaning let's + + + align:start position:0% +let's not play with fire meaning let's +make sure that the safety standards of + + align:start position:0% +make sure that the safety standards of + + + align:start position:0% +make sure that the safety standards of +solar modules are really up to spec so + + align:start position:0% +solar modules are really up to spec so + + + align:start position:0% +solar modules are really up to spec so +that the risk of something + + align:start position:0% +that the risk of something + + + align:start position:0% +that the risk of something +catastrophically bad happening is + + align:start position:0% +catastrophically bad happening is + + + align:start position:0% +catastrophically bad happening is +negligible right because there's nothing + + align:start position:0% +negligible right because there's nothing + + + align:start position:0% +negligible right because there's nothing +worse for a nent industry than to have + + align:start position:0% +worse for a nent industry than to have + + + align:start position:0% +worse for a nent industry than to have +some uh dare I say it Fukushima + + align:start position:0% +some uh dare I say it Fukushima + + + align:start position:0% +some uh dare I say it Fukushima +equivalent occur right on on some very + + align:start position:0% +equivalent occur right on on some very + + + align:start position:0% +equivalent occur right on on some very +high-profile event that causes public + + align:start position:0% +high-profile event that causes public + + + align:start position:0% +high-profile event that causes public +opinion to sway against it so uh making + + align:start position:0% +opinion to sway against it so uh making + + + align:start position:0% +opinion to sway against it so uh making +sure that modules are safe is of most + + align:start position:0% +sure that modules are safe is of most + + + align:start position:0% +sure that modules are safe is of most +importance to preserving the positive + + align:start position:0% +importance to preserving the positive + + + align:start position:0% +importance to preserving the positive +image of solar and that's what this + + align:start position:0% +image of solar and that's what this + + + align:start position:0% +image of solar and that's what this +article here is is meant to convey and + + align:start position:0% +article here is is meant to convey and + + + align:start position:0% +article here is is meant to convey and +you're welcome to read it in detail it + + align:start position:0% +you're welcome to read it in detail it + + + align:start position:0% +you're welcome to read it in detail it +cites one particular example where that + + align:start position:0% +cites one particular example where that + + + align:start position:0% +cites one particular example where that +didn't happen and it did lead to a a + + align:start position:0% +didn't happen and it did lead to a a + + + align:start position:0% +didn't happen and it did lead to a a +little PR U uh event uh well justified + + align:start position:0% +little PR U uh event uh well justified + + + align:start position:0% +little PR U uh event uh well justified +in + + align:start position:0% +in + + + align:start position:0% +in +fact um shown here are a series of tests + + align:start position:0% +fact um shown here are a series of tests + + + align:start position:0% +fact um shown here are a series of tests +that one can conduct with uh solar + + align:start position:0% +that one can conduct with uh solar + + + align:start position:0% +that one can conduct with uh solar +modules um I showed a list of different + + align:start position:0% +modules um I showed a list of different + + + align:start position:0% +modules um I showed a list of different +um of IC tests standardized uh um + + align:start position:0% +um of IC tests standardized uh um + + + align:start position:0% +um of IC tests standardized uh um +protocols these are a series of tests + + align:start position:0% +protocols these are a series of tests + + + align:start position:0% +protocols these are a series of tests +typically between uh say 12 and 20 that + + align:start position:0% +typically between uh say 12 and 20 that + + + align:start position:0% +typically between uh say 12 and 20 that +uh represent a battery of tests for the + + align:start position:0% +uh represent a battery of tests for the + + + align:start position:0% +uh represent a battery of tests for the +solar module and if they pass it they + + align:start position:0% +solar module and if they pass it they + + + align:start position:0% +solar module and if they pass it they +are IEC certified and you'll see on the + + align:start position:0% +are IEC certified and you'll see on the + + + align:start position:0% +are IEC certified and you'll see on the +back of certain spec sheets like this + + align:start position:0% +back of certain spec sheets like this + + + align:start position:0% +back of certain spec sheets like this +one from First Solar right here the + + align:start position:0% +one from First Solar right here the + + + align:start position:0% +one from First Solar right here the +different uh testing agencies that have + + align:start position:0% +different uh testing agencies that have + + + align:start position:0% +different uh testing agencies that have +certified the module right these little + + align:start position:0% +certified the module right these little + + + align:start position:0% +certified the module right these little +uh logos represented so it says uh it's + + align:start position:0% +uh logos represented so it says uh it's + + + align:start position:0% +uh logos represented so it says uh it's +UL certified uh C Mark uh certified + + align:start position:0% +UL certified uh C Mark uh certified + + + align:start position:0% +UL certified uh C Mark uh certified +according to I spec + + align:start position:0% +according to I spec + + + align:start position:0% +according to I spec +61646 that's the one right up there at + + align:start position:0% +61646 that's the one right up there at + + + align:start position:0% +61646 that's the one right up there at +the top and so forth so specification or + + align:start position:0% +the top and so forth so specification or + + + align:start position:0% +the top and so forth so specification or +or or certification is very important + + align:start position:0% +or or certification is very important + + + align:start position:0% +or or certification is very important +what happens during testing well we'll + + align:start position:0% +what happens during testing well we'll + + + align:start position:0% +what happens during testing well we'll +see it because when I designed the front + + align:start position:0% +see it because when I designed the front + + + align:start position:0% +see it because when I designed the front +offer CSC Labs uh we designed it Roland + + align:start position:0% +offer CSC Labs uh we designed it Roland + + + align:start position:0% +offer CSC Labs uh we designed it Roland +Schindler and I with the I tests in mind + + align:start position:0% +Schindler and I with the I tests in mind + + + align:start position:0% +Schindler and I with the I tests in mind +so each of the pieces of equipment out + + align:start position:0% +so each of the pieces of equipment out + + + align:start position:0% +so each of the pieces of equipment out +there are to test one component of the I + + align:start position:0% +there are to test one component of the I + + + align:start position:0% +there are to test one component of the I +test um included in the test is + + align:start position:0% +test um included in the test is + + + align:start position:0% +test um included in the test is +environmental cycling where you take a + + align:start position:0% +environmental cycling where you take a + + + align:start position:0% +environmental cycling where you take a +module inside of this what looks like an + + align:start position:0% +module inside of this what looks like an + + + align:start position:0% +module inside of this what looks like an +oven and heats it up cools it down Heats + + align:start position:0% +oven and heats it up cools it down Heats + + + align:start position:0% +oven and heats it up cools it down Heats +it up cools it down or maintains a high + + align:start position:0% +it up cools it down or maintains a high + + + align:start position:0% +it up cools it down or maintains a high +temperature with high humidity different + + align:start position:0% +temperature with high humidity different + + + align:start position:0% +temperature with high humidity different +types of environmental Chambers do + + align:start position:0% +types of environmental Chambers do + + + align:start position:0% +types of environmental Chambers do +different things but they're meant to + + align:start position:0% +different things but they're meant to + + + align:start position:0% +different things but they're meant to +simulate an accelerated uh aging process + + align:start position:0% +simulate an accelerated uh aging process + + + align:start position:0% +simulate an accelerated uh aging process +again since most diffusion processes are + + align:start position:0% +again since most diffusion processes are + + + align:start position:0% +again since most diffusion processes are +driven by boltzman statistics there's an + + align:start position:0% +driven by boltzman statistics there's an + + + align:start position:0% +driven by boltzman statistics there's an +exponential increase with exponentially + + align:start position:0% +exponential increase with exponentially + + + align:start position:0% +exponential increase with exponentially +increasing temp or with increasing + + align:start position:0% +increasing temp or with increasing + + + align:start position:0% +increasing temp or with increasing +temperature and hence we can simulate + + align:start position:0% +temperature and hence we can simulate + + + align:start position:0% +temperature and hence we can simulate +accelerated degradation at higher + + align:start position:0% +accelerated degradation at higher + + + align:start position:0% +accelerated degradation at higher +temperatures so it's not uncommon that + + align:start position:0% +temperatures so it's not uncommon that + + + align:start position:0% +temperatures so it's not uncommon that +you hear about 8585 tests which mean 85° + + align:start position:0% +you hear about 8585 tests which mean 85° + + + align:start position:0% +you hear about 8585 tests which mean 85° +C at 85% humidity right so that is that + + align:start position:0% +C at 85% humidity right so that is that + + + align:start position:0% +C at 85% humidity right so that is that +is a massive jungle we we don't have + + align:start position:0% +is a massive jungle we we don't have + + + align:start position:0% +is a massive jungle we we don't have +thankfully uh places on Earth like that + + align:start position:0% +thankfully uh places on Earth like that + + + align:start position:0% +thankfully uh places on Earth like that +the maximum temperatures are at around + + align:start position:0% +the maximum temperatures are at around + + + align:start position:0% +the maximum temperatures are at around +45 50 55 degre C typically in in those + + align:start position:0% +45 50 55 degre C typically in in those + + + align:start position:0% +45 50 55 degre C typically in in those +cases very dry but in here 85° C it's + + align:start position:0% +cases very dry but in here 85° C it's + + + align:start position:0% +cases very dry but in here 85° C it's +still below the boiling point of water + + align:start position:0% +still below the boiling point of water + + + align:start position:0% +still below the boiling point of water +very high humidity and the humidity if + + align:start position:0% +very high humidity and the humidity if + + + align:start position:0% +very high humidity and the humidity if +there is any place for the humidity to + + align:start position:0% +there is any place for the humidity to + + + align:start position:0% +there is any place for the humidity to +go inside the module if you have any + + align:start position:0% +go inside the module if you have any + + + align:start position:0% +go inside the module if you have any +failure of your encapsulate material or + + align:start position:0% +failure of your encapsulate material or + + + align:start position:0% +failure of your encapsulate material or +can get inside it will and it'll begin + + align:start position:0% +can get inside it will and it'll begin + + + align:start position:0% +can get inside it will and it'll begin +degrading your module you'll see the + + align:start position:0% +degrading your module you'll see the + + + align:start position:0% +degrading your module you'll see the +power output decrease and after 3 months + + align:start position:0% +power output decrease and after 3 months + + + align:start position:0% +power output decrease and after 3 months +uh subjected to that sort of torture if + + align:start position:0% +uh subjected to that sort of torture if + + + align:start position:0% +uh subjected to that sort of torture if +the module is poorly designed uh often + + align:start position:0% +the module is poorly designed uh often + + + align:start position:0% +the module is poorly designed uh often +times it will fail now some of the + + align:start position:0% +times it will fail now some of the + + + align:start position:0% +times it will fail now some of the +shortcomings of these tests these those + + align:start position:0% +shortcomings of these tests these those + + + align:start position:0% +shortcomings of these tests these those +uh those that humidity uh cycle isn't + + align:start position:0% +uh those that humidity uh cycle isn't + + + align:start position:0% +uh those that humidity uh cycle isn't +necessarily uh with the module uh + + align:start position:0% +necessarily uh with the module uh + + + align:start position:0% +necessarily uh with the module uh +experiencing an applied bias voltage so + + align:start position:0% +experiencing an applied bias voltage so + + + align:start position:0% +experiencing an applied bias voltage so +if there's any electrom migration effect + + align:start position:0% +if there's any electrom migration effect + + + align:start position:0% +if there's any electrom migration effect +uh you might not detect it with that so + + align:start position:0% +uh you might not detect it with that so + + + align:start position:0% +uh you might not detect it with that so +there are people designing new forms of + + align:start position:0% +there are people designing new forms of + + + align:start position:0% +there are people designing new forms of +tests that will uh probe other failure + + align:start position:0% +tests that will uh probe other failure + + + align:start position:0% +tests that will uh probe other failure +modes other degradation mechanisms that + + align:start position:0% +modes other degradation mechanisms that + + + align:start position:0% +modes other degradation mechanisms that +aren't necessarily captured in these IC + + align:start position:0% +aren't necessarily captured in these IC + + + align:start position:0% +aren't necessarily captured in these IC +tests do you have a question no no + + align:start position:0% +tests do you have a question no no + + + align:start position:0% +tests do you have a question no no +question okay yeah over here what is the + + align:start position:0% +question okay yeah over here what is the + + + align:start position:0% +question okay yeah over here what is the +degradation by Water by water yes so + + align:start position:0% +degradation by Water by water yes so + + + align:start position:0% +degradation by Water by water yes so +water humidity um it typically what + + align:start position:0% +water humidity um it typically what + + + align:start position:0% +water humidity um it typically what +happens is in the laminate itself um + + align:start position:0% +happens is in the laminate itself um + + + align:start position:0% +happens is in the laminate itself um +there will be some part at the edge that + + align:start position:0% +there will be some part at the edge that + + + align:start position:0% +there will be some part at the edge that +water can get in not always but in in + + align:start position:0% +water can get in not always but in in + + + align:start position:0% +water can get in not always but in in +the poorly designed ones yes and so the + + align:start position:0% +the poorly designed ones yes and so the + + + align:start position:0% +the poorly designed ones yes and so the +water can get in and begin diffusing in + + align:start position:0% +water can get in and begin diffusing in + + + align:start position:0% +water can get in and begin diffusing in +right uh into the module so so if you + + align:start position:0% +right uh into the module so so if you + + + align:start position:0% +right uh into the module so so if you +have a thin fil material that uh reacts + + align:start position:0% +have a thin fil material that uh reacts + + + align:start position:0% +have a thin fil material that uh reacts +with water you might degrade the actual + + align:start position:0% +with water you might degrade the actual + + + align:start position:0% +with water you might degrade the actual +absorber layer itself if you have a + + align:start position:0% +absorber layer itself if you have a + + + align:start position:0% +absorber layer itself if you have a +silicon device um the water could react + + align:start position:0% +silicon device um the water could react + + + align:start position:0% +silicon device um the water could react +with the metal and cause it to + + align:start position:0% +with the metal and cause it to + + + align:start position:0% +with the metal and cause it to +corrode right cause it to oxidize in + + align:start position:0% +corrode right cause it to oxidize in + + + align:start position:0% +corrode right cause it to oxidize in +other words um and so the and of course + + align:start position:0% +other words um and so the and of course + + + align:start position:0% +other words um and so the and of course +in reacting with the ethyl vinyl acetate + + align:start position:0% +in reacting with the ethyl vinyl acetate + + + align:start position:0% +in reacting with the ethyl vinyl acetate +it can cause the encapsulant to + + align:start position:0% +it can cause the encapsulant to + + + align:start position:0% +it can cause the encapsulant to +delaminate from the + + align:start position:0% +delaminate from the + + + align:start position:0% +delaminate from the +cells and tear apart and so you see this + + align:start position:0% +cells and tear apart and so you see this + + + align:start position:0% +cells and tear apart and so you see this +discoloration of the module um those are + + align:start position:0% +discoloration of the module um those are + + + align:start position:0% +discoloration of the module um those are +some of the failure modes that can occur + + align:start position:0% +some of the failure modes that can occur + + + align:start position:0% +some of the failure modes that can occur +when water gets in through the side if + + align:start position:0% +when water gets in through the side if + + + align:start position:0% +when water gets in through the side if +it manag to permeate the um encapsulant + + align:start position:0% +it manag to permeate the um encapsulant + + + align:start position:0% +it manag to permeate the um encapsulant +materials themselves those sorts of + + align:start position:0% +materials themselves those sorts of + + + align:start position:0% +materials themselves those sorts of +effects can occur directly as opposed to + + align:start position:0% +effects can occur directly as opposed to + + + align:start position:0% +effects can occur directly as opposed to +coming in through the sides another + + align:start position:0% + + + + align:start position:0% + +questiona + + align:start position:0% + + + + align:start position:0% + +yes yep so they presumably test some + + align:start position:0% +yes yep so they presumably test some + + + align:start position:0% +yes yep so they presumably test some +small fraction of the modules and then + + align:start position:0% +small fraction of the modules and then + + + align:start position:0% +small fraction of the modules and then +if those modules pass the test which + + align:start position:0% +if those modules pass the test which + + + align:start position:0% +if those modules pass the test which +takes several months to conduct uh and + + align:start position:0% +takes several months to conduct uh and + + + align:start position:0% +takes several months to conduct uh and +that's why there's a large barrier for + + align:start position:0% +that's why there's a large barrier for + + + align:start position:0% +that's why there's a large barrier for +module Innovation uh + + align:start position:0% +module Innovation uh + + + align:start position:0% +module Innovation uh +but if they pass those tests then they + + align:start position:0% +but if they pass those tests then they + + + align:start position:0% +but if they pass those tests then they +assume that every module is yes so uh + + align:start position:0% +assume that every module is yes so uh + + + align:start position:0% +assume that every module is yes so uh +there there are a series of of of I + + align:start position:0% +there there are a series of of of I + + + align:start position:0% +there there are a series of of of I +would say um definitions of what + + align:start position:0% +would say um definitions of what + + + align:start position:0% +would say um definitions of what +constitutes a major alteration to the + + align:start position:0% +constitutes a major alteration to the + + + align:start position:0% +constitutes a major alteration to the +process so if you majorly alter your + + align:start position:0% +process so if you majorly alter your + + + align:start position:0% +process so if you majorly alter your +process then you have to get your module + + align:start position:0% +process then you have to get your module + + + align:start position:0% +process then you have to get your module +recertified um but if uh if you stay + + align:start position:0% +recertified um but if uh if you stay + + + align:start position:0% +recertified um but if uh if you stay +within those bounds then you can + + align:start position:0% +within those bounds then you can + + + align:start position:0% +within those bounds then you can +continue uh uh selling under the old + + align:start position:0% +continue uh uh selling under the old + + + align:start position:0% +continue uh uh selling under the old +certification um it's not too dissimilar + + align:start position:0% +certification um it's not too dissimilar + + + align:start position:0% +certification um it's not too dissimilar +to say uh the way our food is tested by + + align:start position:0% +to say uh the way our food is tested by + + + align:start position:0% +to say uh the way our food is tested by +the FDA uh it's not every single hand + + align:start position:0% +the FDA uh it's not every single hand + + + align:start position:0% +the FDA uh it's not every single hand +hamburger um it's it's a it's a spot + + align:start position:0% +hamburger um it's it's a it's a spot + + + align:start position:0% +hamburger um it's it's a it's a spot +test um in this particular case these + + align:start position:0% +test um in this particular case these + + + align:start position:0% +test um in this particular case these +are uh examples of the newest uh + + align:start position:0% +are uh examples of the newest uh + + + align:start position:0% +are uh examples of the newest uh +Technologies to come off the line and + + align:start position:0% +Technologies to come off the line and + + + align:start position:0% +Technologies to come off the line and +you get a couple of chances to pass um + + align:start position:0% +you get a couple of chances to pass um + + + align:start position:0% +you get a couple of chances to pass um +if you fail the first one it's not the + + align:start position:0% +if you fail the first one it's not the + + + align:start position:0% +if you fail the first one it's not the +end of the world uh it just means that + + align:start position:0% +end of the world uh it just means that + + + align:start position:0% +end of the world uh it just means that +you have to pass the next time or else + + align:start position:0% +you have to pass the next time or else + + + align:start position:0% +you have to pass the next time or else +you have a stain on your record um and + + align:start position:0% +you have a stain on your record um and + + + align:start position:0% +you have a stain on your record um and +many of the companies now have their own + + align:start position:0% +many of the companies now have their own + + + align:start position:0% +many of the companies now have their own +uh facilities to do these tests inhouse + + align:start position:0% +uh facilities to do these tests inhouse + + + align:start position:0% +uh facilities to do these tests inhouse +they still send them out to the + + align:start position:0% +they still send them out to the + + + align:start position:0% +they still send them out to the +certified testing bodies that are + + align:start position:0% +certified testing bodies that are + + + align:start position:0% +certified testing bodies that are +independent to get the final seal of + + align:start position:0% +independent to get the final seal of + + + align:start position:0% +independent to get the final seal of +approval but they know fairly well + + align:start position:0% +approval but they know fairly well + + + align:start position:0% +approval but they know fairly well +before they send them out are we going + + align:start position:0% +before they send them out are we going + + + align:start position:0% +before they send them out are we going +to pass or not in your early days it was + + align:start position:0% +to pass or not in your early days it was + + + align:start position:0% +to pass or not in your early days it was +you always had to hold on to the seat of + + align:start position:0% +you always had to hold on to the seat of + + + align:start position:0% +you always had to hold on to the seat of +your pants because you never quite knew + + align:start position:0% +your pants because you never quite knew + + + align:start position:0% +your pants because you never quite knew +what was going to happen when test + + align:start position:0% +what was going to happen when test + + + align:start position:0% +what was going to happen when test +results came back um but now um it's + + align:start position:0% +results came back um but now um it's + + + align:start position:0% +results came back um but now um it's +it's it's much better uh much more + + align:start position:0% +it's it's much better uh much more + + + align:start position:0% +it's it's much better uh much more +predictable and my favorite test out of + + align:start position:0% +predictable and my favorite test out of + + + align:start position:0% +predictable and my favorite test out of +all the ones in there there're are + + align:start position:0% +all the ones in there there're are + + + align:start position:0% +all the ones in there there're are +number uh if if you imagine a dozen to + + align:start position:0% +number uh if if you imagine a dozen to + + + align:start position:0% +number uh if if you imagine a dozen to +20 tests uh from Illuminating it and + + align:start position:0% +20 tests uh from Illuminating it and + + + align:start position:0% +20 tests uh from Illuminating it and +measuring the power output um one of my + + align:start position:0% +measuring the power output um one of my + + + align:start position:0% +measuring the power output um one of my +favorite tests involves a hail gun um so + + align:start position:0% +favorite tests involves a hail gun um so + + + align:start position:0% +favorite tests involves a hail gun um so +the the similar manner to how uh the the + + align:start position:0% +the the similar manner to how uh the the + + + align:start position:0% +the the similar manner to how uh the the +FAA tests wind Shields of planes and and + + align:start position:0% +FAA tests wind Shields of planes and and + + + align:start position:0% +FAA tests wind Shields of planes and and +and and plane engines by uh shooting + + align:start position:0% +and and plane engines by uh shooting + + + align:start position:0% +and and plane engines by uh shooting +Frozen chickens or turkeys at them uh in + + align:start position:0% +Frozen chickens or turkeys at them uh in + + + align:start position:0% +Frozen chickens or turkeys at them uh in +this particular case we're shooting + + align:start position:0% +this particular case we're shooting + + + align:start position:0% +this particular case we're shooting +Frozen balls of water at the modules and + + align:start position:0% +Frozen balls of water at the modules and + + + align:start position:0% +Frozen balls of water at the modules and +seeing if they crack um that's one of + + align:start position:0% +seeing if they crack um that's one of + + + align:start position:0% +seeing if they crack um that's one of +the ones uh you can Envision as well an + + align:start position:0% +the ones uh you can Envision as well an + + + align:start position:0% +the ones uh you can Envision as well an +immersion test underwater uh combined + + align:start position:0% +immersion test underwater uh combined + + + align:start position:0% +immersion test underwater uh combined +with bending to see if uh if if there's + + align:start position:0% +with bending to see if uh if if there's + + + align:start position:0% +with bending to see if uh if if there's +any uh failure in the module so we uh + + align:start position:0% +any uh failure in the module so we uh + + + align:start position:0% +any uh failure in the module so we uh +they are tested quite extensively using + + align:start position:0% +they are tested quite extensively using + + + align:start position:0% +they are tested quite extensively using +these protocols and the objective is to + + align:start position:0% +these protocols and the objective is to + + + align:start position:0% +these protocols and the objective is to +ensure quality and safety to the + + align:start position:0% +ensure quality and safety to the + + + align:start position:0% +ensure quality and safety to the +consumer what's the tough + + align:start position:0% +consumer what's the tough + + + align:start position:0% +consumer what's the tough +this top right oh top right over here + + align:start position:0% +this top right oh top right over here + + + align:start position:0% +this top right oh top right over here +this is a mechanical loading test um + + align:start position:0% +this is a mechanical loading test um + + + align:start position:0% +this is a mechanical loading test um +what it appears to be uh where uh you + + align:start position:0% +what it appears to be uh where uh you + + + align:start position:0% +what it appears to be uh where uh you +you just exert um what is typically that + + align:start position:0% +you just exert um what is typically that + + + align:start position:0% +you just exert um what is typically that +that's what it appears to be in this + + align:start position:0% +that's what it appears to be in this + + + align:start position:0% +that's what it appears to be in this +particular case I could be wrong but um + + align:start position:0% +particular case I could be wrong but um + + + align:start position:0% +particular case I could be wrong but um +my understanding is that the this module + + align:start position:0% +my understanding is that the this module + + + align:start position:0% +my understanding is that the this module +is constrained on the edges right now + + align:start position:0% +is constrained on the edges right now + + + align:start position:0% +is constrained on the edges right now +and that there's a load being uh pushed + + align:start position:0% +and that there's a load being uh pushed + + + align:start position:0% +and that there's a load being uh pushed +down in the center um you could also + + align:start position:0% +down in the center um you could also + + + align:start position:0% +down in the center um you could also +Envision a sandbag test where you uh + + align:start position:0% +Envision a sandbag test where you uh + + + align:start position:0% +Envision a sandbag test where you uh +load physical sandbags um there is uh + + align:start position:0% +load physical sandbags um there is uh + + + align:start position:0% +load physical sandbags um there is uh +there are variety of of different types + + align:start position:0% +there are variety of of different types + + + align:start position:0% +there are variety of of different types +in + + align:start position:0% + + + + align:start position:0% + +variants yep okay so that comes from the + + align:start position:0% +variants yep okay so that comes from the + + + align:start position:0% +variants yep okay so that comes from the +First Solar um spec sheet describe the + + align:start position:0% +First Solar um spec sheet describe the + + + align:start position:0% +First Solar um spec sheet describe the +differences between various types of PV + + align:start position:0% +differences between various types of PV + + + align:start position:0% +differences between various types of PV +systems since we're running short on + + align:start position:0% +systems since we're running short on + + + align:start position:0% +systems since we're running short on +time this is a bit of a repeat from uh + + align:start position:0% +time this is a bit of a repeat from uh + + + align:start position:0% +time this is a bit of a repeat from uh +what we talked about uh the very first + + align:start position:0% +what we talked about uh the very first + + + align:start position:0% +what we talked about uh the very first +day in class the non-tracking the + + align:start position:0% +day in class the non-tracking the + + + align:start position:0% +day in class the non-tracking the +tracking um so I'm going to fly through + + align:start position:0% +tracking um so I'm going to fly through + + + align:start position:0% +tracking um so I'm going to fly through +that into grid tied and Standalone right + + align:start position:0% +that into grid tied and Standalone right + + + align:start position:0% +that into grid tied and Standalone right +so grid tied and Standalone systems is + + align:start position:0% +so grid tied and Standalone systems is + + + align:start position:0% +so grid tied and Standalone systems is +very straightforward if if you have a + + align:start position:0% +very straightforward if if you have a + + + align:start position:0% +very straightforward if if you have a +system that is tied to the grid somehow + + align:start position:0% +system that is tied to the grid somehow + + + align:start position:0% +system that is tied to the grid somehow +it has to be able to interface with the + + align:start position:0% +it has to be able to interface with the + + + align:start position:0% +it has to be able to interface with the +grid let me go to that in a second um + + align:start position:0% +grid let me go to that in a second um + + + align:start position:0% +grid let me go to that in a second um +here so if you're having a grid tied + + align:start position:0% +here so if you're having a grid tied + + + align:start position:0% +here so if you're having a grid tied +system that means that your house or or + + align:start position:0% +system that means that your house or or + + + align:start position:0% +system that means that your house or or +or solar array whatever it is that's + + align:start position:0% +or solar array whatever it is that's + + + align:start position:0% +or solar array whatever it is that's +producing the electricity uh has to be + + align:start position:0% +producing the electricity uh has to be + + + align:start position:0% +producing the electricity uh has to be +tied to the grid and interface with it + + align:start position:0% +tied to the grid and interface with it + + + align:start position:0% +tied to the grid and interface with it +since the uh electricity is alternating + + align:start position:0% +since the uh electricity is alternating + + + align:start position:0% +since the uh electricity is alternating +current uh there has to be a device to + + align:start position:0% +current uh there has to be a device to + + + align:start position:0% +current uh there has to be a device to +convert the the direct current power + + align:start position:0% +convert the the direct current power + + + align:start position:0% +convert the the direct current power +into alternating current and that's + + align:start position:0% +into alternating current and that's + + + align:start position:0% +into alternating current and that's +called the inverter we've already + + align:start position:0% +called the inverter we've already + + + align:start position:0% +called the inverter we've already +touched upon that a few times over + + align:start position:0% +touched upon that a few times over + + + align:start position:0% +touched upon that a few times over +today's class and these objects are um + + align:start position:0% +today's class and these objects are um + + + align:start position:0% +today's class and these objects are um +range in size for the ones in the house + + align:start position:0% +range in size for the ones in the house + + + align:start position:0% +range in size for the ones in the house +you could find inverters that are about + + align:start position:0% +you could find inverters that are about + + + align:start position:0% +you could find inverters that are about +y big right that can handle a few + + align:start position:0% +y big right that can handle a few + + + align:start position:0% +y big right that can handle a few +kilowatts uh the ones that are handling + + align:start position:0% +kilowatts uh the ones that are handling + + + align:start position:0% +kilowatts uh the ones that are handling +these large solar field installations or + + align:start position:0% +these large solar field installations or + + + align:start position:0% +these large solar field installations or +segments thereof um let me find a large + + align:start position:0% +segments thereof um let me find a large + + + align:start position:0% +segments thereof um let me find a large +solar field installation for here we go + + align:start position:0% +solar field installation for here we go + + + align:start position:0% +solar field installation for here we go +here are pictures some pictures of large + + align:start position:0% +here are pictures some pictures of large + + + align:start position:0% +here are pictures some pictures of large +solar field installation this is the + + align:start position:0% +solar field installation this is the + + + align:start position:0% +solar field installation this is the +road these little green dots are trees + + align:start position:0% +road these little green dots are trees + + + align:start position:0% +road these little green dots are trees +that's a big field installation right + + align:start position:0% +that's a big field installation right + + + align:start position:0% +that's a big field installation right +there um those inverters are are are + + align:start position:0% +there um those inverters are are are + + + align:start position:0% +there um those inverters are are are +Warehouse can be uh much larger sized + + align:start position:0% +Warehouse can be uh much larger sized + + + align:start position:0% +Warehouse can be uh much larger sized +right uh than the smaller ones that + + align:start position:0% +right uh than the smaller ones that + + + align:start position:0% +right uh than the smaller ones that +you'd find in your + + align:start position:0% +you'd find in your + + + align:start position:0% +you'd find in your +house um and so listing the major + + align:start position:0% +house um and so listing the major + + + align:start position:0% +house um and so listing the major +balance the system components um the PV + + align:start position:0% +balance the system components um the PV + + + align:start position:0% +balance the system components um the PV +array would be connected to the grid VI + + align:start position:0% +array would be connected to the grid VI + + + align:start position:0% +array would be connected to the grid VI +an + + align:start position:0% +an + + + align:start position:0% +an +inverter um the Excess power would be + + align:start position:0% +inverter um the Excess power would be + + + align:start position:0% +inverter um the Excess power would be +sent to the grid causing the meter to + + align:start position:0% +sent to the grid causing the meter to + + + align:start position:0% +sent to the grid causing the meter to +spin backward which is a very gratifying + + align:start position:0% +spin backward which is a very gratifying + + + align:start position:0% +spin backward which is a very gratifying +observation from a homeowner's point of + + align:start position:0% +observation from a homeowner's point of + + + align:start position:0% +observation from a homeowner's point of +view or at at the very least a rate + + align:start position:0% +view or at at the very least a rate + + + align:start position:0% +view or at at the very least a rate +payer utility payers point of view um + + align:start position:0% +payer utility payers point of view um + + + align:start position:0% +payer utility payers point of view um +the uh the act of sending the power back + + align:start position:0% +the uh the act of sending the power back + + + align:start position:0% +the uh the act of sending the power back +to the grid is uh a bit of free riding + + align:start position:0% +to the grid is uh a bit of free riding + + + align:start position:0% +to the grid is uh a bit of free riding +right because I'm not paying for the + + align:start position:0% +right because I'm not paying for the + + + align:start position:0% +right because I'm not paying for the +grid I'm a consumer but I'm getting + + align:start position:0% +grid I'm a consumer but I'm getting + + + align:start position:0% +grid I'm a consumer but I'm getting +credit for the electricity I put back in + + align:start position:0% +credit for the electricity I put back in + + + align:start position:0% +credit for the electricity I put back in +the grid but I'm not helping to maintain + + align:start position:0% +the grid but I'm not helping to maintain + + + align:start position:0% +the grid but I'm not helping to maintain +the grid necessarily I'm paying some + + align:start position:0% +the grid necessarily I'm paying some + + + align:start position:0% +the grid necessarily I'm paying some +transmission and distribution costs on + + align:start position:0% +transmission and distribution costs on + + + align:start position:0% +transmission and distribution costs on +my utility bill um but that's + + align:start position:0% +my utility bill um but that's + + + align:start position:0% +my utility bill um but that's +essentially the same cost that everyone + + align:start position:0% +essentially the same cost that everyone + + + align:start position:0% +essentially the same cost that everyone +else is paying uh utility companies have + + align:start position:0% +else is paying uh utility companies have + + + align:start position:0% +else is paying uh utility companies have +begun getting wise about that and have + + align:start position:0% +begun getting wise about that and have + + + align:start position:0% +begun getting wise about that and have +begun leveraging sech charges based on + + align:start position:0% +begun leveraging sech charges based on + + + align:start position:0% +begun leveraging sech charges based on +the input of solar electricity into the + + align:start position:0% +the input of solar electricity into the + + + align:start position:0% +the input of solar electricity into the +grid which I now pay so I'm no longer a + + align:start position:0% +grid which I now pay so I'm no longer a + + + align:start position:0% +grid which I now pay so I'm no longer a +free rider I was for a little bit um so + + align:start position:0% +free rider I was for a little bit um so + + + align:start position:0% +free rider I was for a little bit um so +mounted onto the roof of the ground if + + align:start position:0% +mounted onto the roof of the ground if + + + align:start position:0% +mounted onto the roof of the ground if +you mount the solar panels you need + + align:start position:0% +you mount the solar panels you need + + + align:start position:0% +you mount the solar panels you need +racking and framing materials that's + + align:start position:0% +racking and framing materials that's + + + align:start position:0% +racking and framing materials that's +also balance the + + align:start position:0% +also balance the + + + align:start position:0% +also balance the +systems okay so uh check check check + + align:start position:0% +systems okay so uh check check check + + + align:start position:0% +systems okay so uh check check check +check you typically have as well a + + align:start position:0% +check you typically have as well a + + + align:start position:0% +check you typically have as well a +circuit breaker uh or just a very simple + + align:start position:0% +circuit breaker uh or just a very simple + + + align:start position:0% +circuit breaker uh or just a very simple +lever that disconnects the solar panel + + align:start position:0% +lever that disconnects the solar panel + + + align:start position:0% +lever that disconnects the solar panel +from the grid why is that important the + + align:start position:0% +from the grid why is that important the + + + align:start position:0% +from the grid why is that important the +utility companies know that on my house + + align:start position:0% +utility companies know that on my house + + + align:start position:0% +utility companies know that on my house +in Cambridge there is a solar array and + + align:start position:0% +in Cambridge there is a solar array and + + + align:start position:0% +in Cambridge there is a solar array and +that that array is connected to the grid + + align:start position:0% +that that array is connected to the grid + + + align:start position:0% +that that array is connected to the grid +let's imagine a tree falls in the power + + align:start position:0% +let's imagine a tree falls in the power + + + align:start position:0% +let's imagine a tree falls in the power +lines and during the next storm and the + + align:start position:0% +lines and during the next storm and the + + + align:start position:0% +lines and during the next storm and the +utility crew has to go out there to + + align:start position:0% +utility crew has to go out there to + + + align:start position:0% +utility crew has to go out there to +repair it during the day they know that + + align:start position:0% +repair it during the day they know that + + + align:start position:0% +repair it during the day they know that +although the rest of the grid is down + + align:start position:0% +although the rest of the grid is down + + + align:start position:0% +although the rest of the grid is down +there's that one little power center on + + align:start position:0% +there's that one little power center on + + + align:start position:0% +there's that one little power center on +my house that's uh injecting power into + + align:start position:0% +my house that's uh injecting power into + + + align:start position:0% +my house that's uh injecting power into +the grid and so they'll come along to my + + align:start position:0% +the grid and so they'll come along to my + + + align:start position:0% +the grid and so they'll come along to my +house disconnect the solar panels from + + align:start position:0% +house disconnect the solar panels from + + + align:start position:0% +house disconnect the solar panels from +the grid they'll go to my neighbors + + align:start position:0% +the grid they'll go to my neighbors + + + align:start position:0% +the grid they'll go to my neighbors +disconnect theirs as well go to the + + align:start position:0% +disconnect theirs as well go to the + + + align:start position:0% +disconnect theirs as well go to the +person across the street who also has + + align:start position:0% +person across the street who also has + + + align:start position:0% +person across the street who also has +solar panels disconnect them then go to + + align:start position:0% +solar panels disconnect them then go to + + + align:start position:0% +solar panels disconnect them then go to +work on the utility line so that's why + + align:start position:0% +work on the utility line so that's why + + + align:start position:0% +work on the utility line so that's why +the external uh + + align:start position:0% +the external uh + + + align:start position:0% +the external uh +uh uh circuit breaker is very important + + align:start position:0% +uh uh circuit breaker is very important + + + align:start position:0% +uh uh circuit breaker is very important +back to inverters um modern efficiencies + + align:start position:0% +back to inverters um modern efficiencies + + + align:start position:0% +back to inverters um modern efficiencies +of the inverter component range between + + align:start position:0% +of the inverter component range between + + + align:start position:0% +of the inverter component range between +94 and 97% typical um record inverter + + align:start position:0% +94 and 97% typical um record inverter + + + align:start position:0% +94 and 97% typical um record inverter +efficiencies up to 99% have been + + align:start position:0% +efficiencies up to 99% have been + + + align:start position:0% +efficiencies up to 99% have been +demonstrated + + align:start position:0% +demonstrated + + + align:start position:0% +demonstrated +um and they all have what's called + + align:start position:0% +um and they all have what's called + + + align:start position:0% +um and they all have what's called +maximum PowerPoint tracking which means + + align:start position:0% +maximum PowerPoint tracking which means + + + align:start position:0% +maximum PowerPoint tracking which means +that they will be able to sense what the + + align:start position:0% +that they will be able to sense what the + + + align:start position:0% +that they will be able to sense what the +combined output is of the array on your + + align:start position:0% +combined output is of the array on your + + + align:start position:0% +combined output is of the array on your +roof and adjust the uh the the the the + + align:start position:0% +roof and adjust the uh the the the the + + + align:start position:0% +roof and adjust the uh the the the the +resistance in the circuit to match the + + align:start position:0% +resistance in the circuit to match the + + + align:start position:0% +resistance in the circuit to match the +maximum power point and that way you're + + align:start position:0% +maximum power point and that way you're + + + align:start position:0% +maximum power point and that way you're +producing the maximum amount of power + + align:start position:0% +producing the maximum amount of power + + + align:start position:0% +producing the maximum amount of power +that you could be potentially under any + + align:start position:0% +that you could be potentially under any + + + align:start position:0% +that you could be potentially under any +given illumination condition so a lot of + + align:start position:0% +given illumination condition so a lot of + + + align:start position:0% +given illumination condition so a lot of +fancy Electronics goes into the inverter + + align:start position:0% +fancy Electronics goes into the inverter + + + align:start position:0% +fancy Electronics goes into the inverter +I really have to um I really have to + + align:start position:0% +I really have to um I really have to + + + align:start position:0% +I really have to um I really have to +give them a lot of respect in that + + align:start position:0% +give them a lot of respect in that + + + align:start position:0% +give them a lot of respect in that +regard typically 5 to seven maybe even + + align:start position:0% +regard typically 5 to seven maybe even + + + align:start position:0% +regard typically 5 to seven maybe even +10 year manufacturer + + align:start position:0% + + + + align:start position:0% + +warranty and um the mounting methods we + + align:start position:0% +warranty and um the mounting methods we + + + align:start position:0% +warranty and um the mounting methods we +talked about mounting and racking um + + align:start position:0% +talked about mounting and racking um + + + align:start position:0% +talked about mounting and racking um +this type was fairly common in the early + + align:start position:0% +this type was fairly common in the early + + + align:start position:0% +this type was fairly common in the early +days of solar we had these uh field + + align:start position:0% +days of solar we had these uh field + + + align:start position:0% +days of solar we had these uh field +installations especially built on hills + + align:start position:0% +installations especially built on hills + + + align:start position:0% +installations especially built on hills +in California um would say most common + + align:start position:0% +in California um would say most common + + + align:start position:0% +in California um would say most common +Now is really just mounting directly on + + align:start position:0% +Now is really just mounting directly on + + + align:start position:0% +Now is really just mounting directly on +a roof often times flat uh for large + + align:start position:0% +a roof often times flat uh for large + + + align:start position:0% +a roof often times flat uh for large +field installations one AIS trackers are + + align:start position:0% +field installations one AIS trackers are + + + align:start position:0% +field installations one AIS trackers are +are very common nowadays tracking as a + + align:start position:0% +are very common nowadays tracking as a + + + align:start position:0% +are very common nowadays tracking as a +function of time of day and then + + align:start position:0% +function of time of day and then + + + align:start position:0% +function of time of day and then +manually adjusting the entire array uh + + align:start position:0% +manually adjusting the entire array uh + + + align:start position:0% +manually adjusting the entire array uh +for season if need be so the grid tide + + align:start position:0% +for season if need be so the grid tide + + + align:start position:0% +for season if need be so the grid tide +systems causing meters to spin backward + + align:start position:0% +systems causing meters to spin backward + + + align:start position:0% +systems causing meters to spin backward +again very gratifying and um this is an + + align:start position:0% +again very gratifying and um this is an + + + align:start position:0% +again very gratifying and um this is an +example of my utility bill um where you + + align:start position:0% +example of my utility bill um where you + + + align:start position:0% +example of my utility bill um where you +have a balance of + + align:start position:0% +have a balance of + + + align:start position:0% +have a balance of +$163 negative um so they're giving me + + align:start position:0% +$163 negative um so they're giving me + + + align:start position:0% +$163 negative um so they're giving me +credit over the course of a year uh in + + align:start position:0% +credit over the course of a year uh in + + + align:start position:0% +credit over the course of a year uh in +the winter time this was an example of a + + align:start position:0% +the winter time this was an example of a + + + align:start position:0% +the winter time this was an example of a +month in December when a lot of snow + + align:start position:0% +month in December when a lot of snow + + + align:start position:0% +month in December when a lot of snow +happened and uh the panels were covered + + align:start position:0% +happened and uh the panels were covered + + + align:start position:0% +happened and uh the panels were covered +for quite a while or at least partially + + align:start position:0% +for quite a while or at least partially + + + align:start position:0% +for quite a while or at least partially +shaded by the snow for a while right um + + align:start position:0% +shaded by the snow for a while right um + + + align:start position:0% +shaded by the snow for a while right um +and we drew power from the Grid on net + + align:start position:0% +and we drew power from the Grid on net + + + align:start position:0% +and we drew power from the Grid on net +that month but in all the other months + + align:start position:0% +that month but in all the other months + + + align:start position:0% +that month but in all the other months +we unet produced power and negative + + align:start position:0% +we unet produced power and negative + + + align:start position:0% +we unet produced power and negative +numbers aren't shown on the scale here + + align:start position:0% +numbers aren't shown on the scale here + + + align:start position:0% +numbers aren't shown on the scale here +but uh if they were shown you'd see uh + + align:start position:0% +but uh if they were shown you'd see uh + + + align:start position:0% +but uh if they were shown you'd see uh +probably a greater negative value in the + + align:start position:0% +probably a greater negative value in the + + + align:start position:0% +probably a greater negative value in the +summertime in other words we're + + align:start position:0% +summertime in other words we're + + + align:start position:0% +summertime in other words we're +producing a lot of power in the summer + + align:start position:0% +producing a lot of power in the summer + + + align:start position:0% +producing a lot of power in the summer +more sun and at the end of the year they + + align:start position:0% +more sun and at the end of the year they + + + align:start position:0% +more sun and at the end of the year they +draw a line at the bottom and they say + + align:start position:0% +draw a line at the bottom and they say + + + align:start position:0% +draw a line at the bottom and they say +did you owe us money no all right great + + align:start position:0% +did you owe us money no all right great + + + align:start position:0% +did you owe us money no all right great +if you if we owed you money tough luck + + align:start position:0% +if you if we owed you money tough luck + + + align:start position:0% +if you if we owed you money tough luck +um if if we're zero then everybody's + + align:start position:0% +um if if we're zero then everybody's + + + align:start position:0% +um if if we're zero then everybody's +happy uh so we typically produce more + + align:start position:0% +happy uh so we typically produce more + + + align:start position:0% +happy uh so we typically produce more +electricity than we consume in our in + + align:start position:0% +electricity than we consume in our in + + + align:start position:0% +electricity than we consume in our in +our house and that's an example of what + + align:start position:0% +our house and that's an example of what + + + align:start position:0% +our house and that's an example of what +happens on a practical level um off grid + + align:start position:0% +happens on a practical level um off grid + + + align:start position:0% +happens on a practical level um off grid +PV systems just ever so briefly + + align:start position:0% +PV systems just ever so briefly + + + align:start position:0% +PV systems just ever so briefly +um so uh let's imagine that you're uh + + align:start position:0% +um so uh let's imagine that you're uh + + + align:start position:0% +um so uh let's imagine that you're uh +running some illicit business and you + + align:start position:0% +running some illicit business and you + + + align:start position:0% +running some illicit business and you +want to be off grid or uh let's imagine + + align:start position:0% +want to be off grid or uh let's imagine + + + align:start position:0% +want to be off grid or uh let's imagine +that you're uh instead uh let's let's a + + align:start position:0% +that you're uh instead uh let's let's a + + + align:start position:0% +that you're uh instead uh let's let's a +more realistic example let's say that + + align:start position:0% +more realistic example let's say that + + + align:start position:0% +more realistic example let's say that +you're um afraid of the next power + + align:start position:0% +you're um afraid of the next power + + + align:start position:0% +you're um afraid of the next power +outage of being out of power for the + + align:start position:0% +outage of being out of power for the + + + align:start position:0% +outage of being out of power for the +next s to 10 days after the the storm + + align:start position:0% +next s to 10 days after the the storm + + + align:start position:0% +next s to 10 days after the the storm +passes through your house and you want + + align:start position:0% +passes through your house and you want + + + align:start position:0% +passes through your house and you want +to isolate yourself from the grid if + + align:start position:0% +to isolate yourself from the grid if + + + align:start position:0% +to isolate yourself from the grid if +need be you would want to have a charge + + align:start position:0% +need be you would want to have a charge + + + align:start position:0% +need be you would want to have a charge +controller that would be able to uh + + align:start position:0% +controller that would be able to uh + + + align:start position:0% +controller that would be able to uh +distribute the power to the DC loads or + + align:start position:0% +distribute the power to the DC loads or + + + align:start position:0% +distribute the power to the DC loads or +to batteries to store them um and then + + align:start position:0% +to batteries to store them um and then + + + align:start position:0% +to batteries to store them um and then +the inverter going to the AC loads or to + + align:start position:0% +the inverter going to the AC loads or to + + + align:start position:0% +the inverter going to the AC loads or to +the grid thereafter um so it is possible + + align:start position:0% +the grid thereafter um so it is possible + + + align:start position:0% +the grid thereafter um so it is possible +to architect A system that is uh + + align:start position:0% +to architect A system that is uh + + + align:start position:0% +to architect A system that is uh +semi-autonomous but it does require more + + align:start position:0% +semi-autonomous but it does require more + + + align:start position:0% +semi-autonomous but it does require more +components and more cost + + align:start position:0% +components and more cost + + + align:start position:0% +components and more cost +right and I just wanted to emphasize one + + align:start position:0% +right and I just wanted to emphasize one + + + align:start position:0% +right and I just wanted to emphasize one +thing as we we close up life is really + + align:start position:0% +thing as we we close up life is really + + + align:start position:0% +thing as we we close up life is really +good as an installer right now if we + + align:start position:0% +good as an installer right now if we + + + align:start position:0% +good as an installer right now if we +flashed back to four or five years ago + + align:start position:0% +flashed back to four or five years ago + + + align:start position:0% +flashed back to four or five years ago +life would have been really good as a a + + align:start position:0% +life would have been really good as a a + + + align:start position:0% +life would have been really good as a a +solar uh panel producer especially if + + align:start position:0% +solar uh panel producer especially if + + + align:start position:0% +solar uh panel producer especially if +you were involved in the feed stock + + align:start position:0% +you were involved in the feed stock + + + align:start position:0% +you were involved in the feed stock +industry but now the prices of modules + + align:start position:0% +industry but now the prices of modules + + + align:start position:0% +industry but now the prices of modules +have been severely + + align:start position:0% +have been severely + + + align:start position:0% +have been severely +squeezed by lowcost competition from + + align:start position:0% +squeezed by lowcost competition from + + + align:start position:0% +squeezed by lowcost competition from +overseas and the pricing of modules is + + align:start position:0% +overseas and the pricing of modules is + + + align:start position:0% +overseas and the pricing of modules is +around $13 per Watt peak this is some of + + align:start position:0% +around $13 per Watt peak this is some of + + + align:start position:0% +around $13 per Watt peak this is some of +the the the lowest cost uh uh lowest + + align:start position:0% +the the the lowest cost uh uh lowest + + + align:start position:0% +the the the lowest cost uh uh lowest +price modules that are out there right + + align:start position:0% +price modules that are out there right + + + align:start position:0% +price modules that are out there right +now and the price of installing the + + align:start position:0% +now and the price of installing the + + + align:start position:0% +now and the price of installing the +system on your roof here in the US is + + align:start position:0% +system on your roof here in the US is + + + align:start position:0% +system on your roof here in the US is +around + + align:start position:0% +around + + + align:start position:0% +around +$520 who's pocketing the + + align:start position:0% +$520 who's pocketing the + + + align:start position:0% +$520 who's pocketing the +$4.20 who gets to keep that + + align:start position:0% +$4.20 who gets to keep that + + + align:start position:0% +$4.20 who gets to keep that +money is it the installer or the module + + align:start position:0% +money is it the installer or the module + + + align:start position:0% +money is it the installer or the module +producer it's got to be the installer + + align:start position:0% +producer it's got to be the installer + + + align:start position:0% +producer it's got to be the installer +right and who's suffering right now in + + align:start position:0% +right and who's suffering right now in + + + align:start position:0% +right and who's suffering right now in +in the industry no matter where you are + + align:start position:0% +in the industry no matter where you are + + + align:start position:0% +in the industry no matter where you are +us China Germany who's suffering right + + align:start position:0% +us China Germany who's suffering right + + + align:start position:0% +us China Germany who's suffering right +now the module producers right the + + align:start position:0% +now the module producers right the + + + align:start position:0% +now the module producers right the +people manufacturing this stuff right + + align:start position:0% +people manufacturing this stuff right + + + align:start position:0% +people manufacturing this stuff right +here all right which brings me to my + + align:start position:0% +here all right which brings me to my + + + align:start position:0% +here all right which brings me to my +current topic of the day everybody + + align:start position:0% +current topic of the day everybody + + + align:start position:0% +current topic of the day everybody +picked up this one right here this Green + + align:start position:0% +picked up this one right here this Green + + + align:start position:0% +picked up this one right here this Green +Tech media article this is really + + align:start position:0% +Tech media article this is really + + + align:start position:0% +Tech media article this is really +current November 8th that was two days + + align:start position:0% +current November 8th that was two days + + + align:start position:0% +current November 8th that was two days +ago uh Eric wof he's uh higher up there + + align:start position:0% +ago uh Eric wof he's uh higher up there + + + align:start position:0% +ago uh Eric wof he's uh higher up there +in Green Tech media and he's writing + + align:start position:0% +in Green Tech media and he's writing + + + align:start position:0% +in Green Tech media and he's writing +about the China us trade War uh that's + + align:start position:0% +about the China us trade War uh that's + + + align:start position:0% +about the China us trade War uh that's +evolving + + align:start position:0% +evolving + + + align:start position:0% +evolving +pitting within the US pitting the module + + align:start position:0% +pitting within the US pitting the module + + + align:start position:0% +pitting within the US pitting the module +manufacturers against the + + align:start position:0% +manufacturers against the + + + align:start position:0% +manufacturers against the +installers right so the installers these + + align:start position:0% +installers right so the installers these + + + align:start position:0% +installers right so the installers these +guys who are pocketing a lot of money + + align:start position:0% +guys who are pocketing a lot of money + + + align:start position:0% +guys who are pocketing a lot of money +right now are saying no no no no no let + + align:start position:0% +right now are saying no no no no no let + + + align:start position:0% +right now are saying no no no no no let +the Chinese modules come in it's great + + align:start position:0% +the Chinese modules come in it's great + + + align:start position:0% +the Chinese modules come in it's great +for it's it's it keeps are are cost low + + align:start position:0% +for it's it's it keeps are are cost low + + + align:start position:0% +for it's it's it keeps are are cost low +the folks who are manufacturing the + + align:start position:0% +the folks who are manufacturing the + + + align:start position:0% +the folks who are manufacturing the +modules on the other hand are saying + + align:start position:0% +modules on the other hand are saying + + + align:start position:0% +modules on the other hand are saying +well wait a second uh they got uh unfair + + align:start position:0% +well wait a second uh they got uh unfair + + + align:start position:0% +well wait a second uh they got uh unfair +uh treatment by their government and the + + align:start position:0% +uh treatment by their government and the + + + align:start position:0% +uh treatment by their government and the +Chinese module manufacturers in turn are + + align:start position:0% +Chinese module manufacturers in turn are + + + align:start position:0% +Chinese module manufacturers in turn are +saying well it's not only us who are + + align:start position:0% +saying well it's not only us who are + + + align:start position:0% +saying well it's not only us who are +getting subsidies from the government + + align:start position:0% +getting subsidies from the government + + + align:start position:0% +getting subsidies from the government +look at yourselves you got subsidies too + + align:start position:0% +look at yourselves you got subsidies too + + + align:start position:0% +look at yourselves you got subsidies too +and the US manufacturers say well well + + align:start position:0% +and the US manufacturers say well well + + + align:start position:0% +and the US manufacturers say well well +you got more subsidies than we did so + + align:start position:0% +you got more subsidies than we did so + + + align:start position:0% +you got more subsidies than we did so +it's it's evolving into a little bit of + + align:start position:0% +it's it's evolving into a little bit of + + + align:start position:0% +it's it's evolving into a little bit of +a a complex situation there are some + + align:start position:0% +a a complex situation there are some + + + align:start position:0% +a a complex situation there are some +people trying to cut through all of that + + align:start position:0% +people trying to cut through all of that + + + align:start position:0% +people trying to cut through all of that +and say with very simplistic messages um + + align:start position:0% +and say with very simplistic messages um + + + align:start position:0% +and say with very simplistic messages um +free trade or certain other people + + align:start position:0% +free trade or certain other people + + + align:start position:0% +free trade or certain other people +saying made in USA is important or other + + align:start position:0% +saying made in USA is important or other + + + align:start position:0% +saying made in USA is important or other +people saying um this is unfair for one + + align:start position:0% +people saying um this is unfair for one + + + align:start position:0% +people saying um this is unfair for one +reason or another but it's important to + + align:start position:0% +reason or another but it's important to + + + align:start position:0% +reason or another but it's important to +really understand the complexity of + + align:start position:0% +really understand the complexity of + + + align:start position:0% +really understand the complexity of +what's going on in the context of a + + align:start position:0% +what's going on in the context of a + + + align:start position:0% +what's going on in the context of a +dynamically changing market right the + + align:start position:0% +dynamically changing market right the + + + align:start position:0% +dynamically changing market right the +the market is changing quite uh quite a + + align:start position:0% +the market is changing quite uh quite a + + + align:start position:0% +the market is changing quite uh quite a +lot in the past the module prices and I + + align:start position:0% +lot in the past the module prices and I + + + align:start position:0% +lot in the past the module prices and I +say past recent past as in a year ago + + align:start position:0% +say past recent past as in a year ago + + + align:start position:0% +say past recent past as in a year ago +module prices were upward of of 250 $3 + + align:start position:0% +module prices were upward of of 250 $3 + + + align:start position:0% +module prices were upward of of 250 $3 +per Watt peak right it's only in the + + align:start position:0% +per Watt peak right it's only in the + + + align:start position:0% +per Watt peak right it's only in the +over Supply condition created within the + + align:start position:0% +over Supply condition created within the + + + align:start position:0% +over Supply condition created within the +last year and a half where the module + + align:start position:0% +last year and a half where the module + + + align:start position:0% +last year and a half where the module +prices have dropped precipitously down + + align:start position:0% +prices have dropped precipitously down + + + align:start position:0% +prices have dropped precipitously down +to a dollar and that happens when you're + + align:start position:0% +to a dollar and that happens when you're + + + align:start position:0% +to a dollar and that happens when you're +in an over Supply + + align:start position:0% +in an over Supply + + + align:start position:0% +in an over Supply +condition whereas these uh um you know + + align:start position:0% +condition whereas these uh um you know + + + align:start position:0% +condition whereas these uh um you know +these these these installation prices + + align:start position:0% +these these these installation prices + + + align:start position:0% +these these these installation prices +really haven't budged too much they're + + align:start position:0% +really haven't budged too much they're + + + align:start position:0% +really haven't budged too much they're +enjoying the fact that this in an over + + align:start position:0% +enjoying the fact that this in an over + + + align:start position:0% +enjoying the fact that this in an over +Supply condition and there's still a + + align:start position:0% +Supply condition and there's still a + + + align:start position:0% +Supply condition and there's still a +market for their modules + + align:start position:0% +market for their modules + + + align:start position:0% +market for their modules +so it's complex we'll explore the some + + align:start position:0% +so it's complex we'll explore the some + + + align:start position:0% +so it's complex we'll explore the some +of the issues uh some of the complex + + align:start position:0% +of the issues uh some of the complex + + + align:start position:0% +of the issues uh some of the complex +issues uh in our next few classes and + + align:start position:0% +issues uh in our next few classes and + + + align:start position:0% +issues uh in our next few classes and +we'll dive into that in detail a leave + + align:start position:0% +we'll dive into that in detail a leave + + + align:start position:0% +we'll dive into that in detail a leave +for you to study on your own life cycle + + align:start position:0% +for you to study on your own life cycle + + + align:start position:0% +for you to study on your own life cycle +analysis it's very important life cycle + + align:start position:0% +analysis it's very important life cycle + + + align:start position:0% +analysis it's very important life cycle +analysis in in a nutshell really depends + + align:start position:0% +analysis in in a nutshell really depends + + + align:start position:0% +analysis in in a nutshell really depends +on what you consider in your analysis + + align:start position:0% +on what you consider in your analysis + + + align:start position:0% +on what you consider in your analysis +right where you draw the box and uh at + + align:start position:0% +right where you draw the box and uh at + + + align:start position:0% +right where you draw the box and uh at +the end of the day module recycling is + + align:start position:0% +the end of the day module recycling is + + + align:start position:0% +the end of the day module recycling is +going to be important as well uh uh for + + align:start position:0% +going to be important as well uh uh for + + + align:start position:0% +going to be important as well uh uh for +determining the ultimate uh impact in + + align:start position:0% +determining the ultimate uh impact in + + + align:start position:0% +determining the ultimate uh impact in +both in terms of CO2 impact energy + + align:start position:0% +both in terms of CO2 impact energy + + + align:start position:0% +both in terms of CO2 impact energy +payback and environmental impact of PV + + align:start position:0% +payback and environmental impact of PV + + + align:start position:0% +payback and environmental impact of PV +in the long run so I'll leave you with + + align:start position:0% +in the long run so I'll leave you with + + + align:start position:0% +in the long run so I'll leave you with +those thoughts and we'll see us on + + align:start position:0% +those thoughts and we'll see us on + + + align:start position:0% +those thoughts and we'll see us on +Tuesday e \ No newline at end of file diff --git a/C95294_vvQY.txt b/C95294_vvQY.txt new file mode 100644 index 0000000000000000000000000000000000000000..653276656d4d99726eb88d4d0cca908f0a88e181 --- /dev/null +++ b/C95294_vvQY.txt @@ -0,0 +1,4720 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK. + +So we've been talking about +predicting structure proteins. + +At the end of the +last lecture we + +started to talk a little bit +about predicting interactions, + +and that's going to be the +focus of today's lecture. + +And we identified a couple of +different possible prediction + +challenges. + +One was quantitative +predictions of what + +happens when you make specific +mutations in a known protein + +complex. + +We talked about +trying to predict + +the structure of, say, +just a pair of proteins, + +and then trying to do that +on the global scale for all + +known proteins. + +And so last time, +if you recall, we + +thought that initially maybe +this would be a simple problem. + +We have proteins of known +structure with a complex. + +Structure of the +complex is also known. + +And we want to make predictions +as to the change in affinity + +when there's a +specific mutation made. + +In principle, this +should be easy + +because we have all those +different formulations + +for the potential +energy function. + +And so if we figure out what +the local structural changes are + +that are due to the insertion +or deletion of some side chain, + +then we should be +able to predict + +the change in the +potential energy, + +and therefore the change in +the energy of the complex. + +But in fact, it +turned out that it + +was very, very hard to do that. + +And so this plot compared-- +the black circles + +were the prediction +algorithms for this problem, + +compared to just simply +a substitution matrix, + +the BLOSUM substitution matrix +defined in terms of the area + +under the curve for +beneficial mutations + +and deleterious mutations. + +And you can see that very, +very few of the black dots + +get far away from what is the +really simple default model. + +A lot of them do worse. + +So OK, well maybe that's +not such a simple problem + +because it requires a highly +quantitative prediction. + +Maybe we'll do +better just trying + +to predict which +proteins interact at all. + +And so that's going to be +the focus of today's lecture. + +Now, that also had +a problem, right? + +Because even if I know the +structure of two proteins, + +I don't know necessarily +what surfaces + +of those proteins interact. + +And so I have to +figure out this docking + +problem of which part +of protein A interacts + +with which part of protein B. + +That's the beginning +of my problem, + +and then I have to make a +series of subsequent decisions. + +So I'm going to +have to figure out + +for any potential +partner of my protein, + +I need to figure out +the docking problem, + +the relative +position orientation. + +Now, in this little +cartoon, it's + +shown as a completely +static protein that + +approaches another +static protein. + +The only thing that's changing +is the relative coordinates. + +But of course, there +will be local changes + +in confirmation, perhaps +even global ones. + +And so we need to be able +to make some estimates as + +to what those structural +rearrangements will + +be when the two +proteins interact. + +And then after we've +come up with our best + +estimate of the +structural rearrangements, + +only then can we come up with +an estimate of the energy + +interaction and +decide whether it's + +better than some threshold. + +OK. + +So one of the problems that's +pretty obvious from this + +is that this kind of +approach in principle, + +if we do it rigorously +through all the steps, + +would be extremely slow. + +Now, another part that's perhaps +a little bit less obvious + +is that it's going to be very +prone to false positives. + +And why do you +think that might be? + +What am I not taking +into account here? + +AUDIENCE: Are you +not taking into + +account the desolvation +[INAUDIBLE]. + +PROFESSOR: So one +answer is I'm not + +taking account of +the desolvation, + +but in fact, I can do that. + +Right? + +So some of the potential +energy functions + +we looked at, the +statistician's version rather + +than the physicist's +makes it pretty easy + +to incorporate the desolvation. + +Any other thoughts as to what +I'm not taking into account? + +What other protein +should I be considering + +when I'm considering +an interaction problem? + +So I've isolated, in +this case, two proteins. + +I'm saying, in a universe +where these are the only two + +proteins that exist, will +they have a favorable energy + +interaction? + +What I really need to know is +whether that energy interaction + +is more favorable than all +the competing interactions + +that they could have. + +So even if I find something +that's potentially + +a good interaction, it may +not be the best possible + +interaction. + +And if I consider then the +concentration of this protein + +and the concentration of +all the other molecules + +out there that have +a higher affinity, + +then it could turn out +that this is actually + +a rather poor substrate +for my protein, a rather + +poor interaction partner. + +So we have that false +positive problem. + +OK. + +But let's focus on the +computational efficiency + +problem, because +that's at least one + +that we can come up with +some nice algorithms + +to try to solve. + +So what we want to do is try +to limit our search space. + +If I want to figure out-- +I have a query protein + +and I want to ask, what +does it interact with, + +instead of trying to do +the pairwise comparison + +of this protein with every +other protein in the database, + +and doing very precise +structural calculations on all + +of those, maybe +there's some way that I + +can prefilter the +set of proteins + +that it might interact with. + +And that's what we're +going to look at. + +So we're going to try +to officially choose + +potential partners +before we're doing + +any structural comparison. + +And then once we +have those partners, + +we're going to try +to avoid having + +to do detailed calculations +until we have a relatively + +high degree of confidence that +these proteins could interact + +by other criteria. + +And we're going to look at two +papers that describe algorithms + +for solving this +problem, and they're + +both uploaded to the website. + +The first thing +that we'll look at + +is called PRISM that actually +uses structural calculations. + +And then we'll look +at PrePPI, which + +deals with everything +purely at-- without actually + +explicitly calculating +the structures. + +OK. + +So what does PRISM do? + +Well, it's based on +the notion that there + +are a limited number +of architectures + +that we could look at for +which proteins can interact. + +And so if we can identify +those architectures, + +then we can try to figure +out whether a protein is + +a potential partner +of another one + +before we do the detailed, +costly calculations. + +In addition, in +those architectures, + +not all amino acids +are going to be equal, + +but there are going +to be some that + +contribute more to the +energy than others. + +And so by identifying +those critical residues, + +we can once again focus +our computational energy + +on those complexes that are +most likely to be important. + +OK. + +So it has these two components-- +a rigid-body structural + +comparison. + +So that's that two +proteins are not + +changing their own +coordinates, they're + +just being brought together +in different conformations. + +And then once the proteins +have passed a series of checks, + +then we allow for +flexible refinement using + +the kinds of energies we looked +at in the previous lectures + +to decide how high affinity +this complex could be. + +And the critical +thing is that we're + +going to make some of +these early decisions + +after the rigid-body comparison +using structural similarity, + +evolutionary conservation, +and particularly + +looking at these regions +that are called hotspots. + +These are sites where most of +the free energy of interaction + +occurs during an interface. + +So it's not, as I said, +uniformly distributed. + +So I showed you this +slide last time. + +It shows chymotrypsin in a +light gray and its interaction + +with some protein partners. + +These two share some global +similarity to each other, + +whereas this partner is +quite different from either + +of these two globally. + +But you can see that +at the interface, + +it's actually quite similar. + +And so this gives you hope that +even if you can't find a direct + +homologue-- so if you +were trying to figure out, + +what does this protein +in yellow interact with, + +and you searched the database +and you couldn't find anything + +that was its +structural homologue, + +but if you could figure +out to look for homologues + +of the lower regions +that interact, + +you might be able to figure out +that it interacts with the same + +protein as this +one and this one. + +OK. + +So what about this +idea of hotspots? + +And this was an +idea that was first + +developed in 1995 by this +paper, Clackson and Wells, + +where they were looking at the +interaction of a cell surface + +receptor with its +ligand approaching. + +And they did +systematic mutagenesis + +across the surface +of the interface + +to see when I mutate any +single amino acid to alanine, + +how much it affects the +energy of interaction. + +What they found was things +were highly non-uniform. + +So this lower curve shows +the change in free energy + +when you mutate particular +individual amino acids + +to alanine. + +And you can see there are +big losses of free energy + +at some places, and +other places there's + +almost no change in the +free energy binding. + +In a few places you +actually get a benefit + +from mutating a side +chain to alanine. + +So in this particular +case, and it's + +held up over many, +many cases then, + +the free energy of binding is +not uniform across the surface, + +but it's distributed in what +has been called hotspots. + +So here is a structure +of the human growth + +hormone and its receptor. + +And in red are the +few amino acids that + +contribute very, very large +amounts-- more than one + +and a half kcals per mole-- +to the energy of interaction. + +And it doesn't correspond +with any simple structural + +parameter. + +So it's not the amino acids +that have the biggest surface + +area, for example, or +anything like that. + +So it's not trivial to figure +out what these regions are, + +although there are some +prediction algorithms. + +So there are studies, +and subsequent ones + +have indicated that roughly +10% of the amino acids + +at the interface +are the ones that + +have the biggest contribution. + +There are some trends, but +none of these are hard rules. + +These tend to be rich in +these three amino acids-- + +tryptophan, arginine, +and tyrosine. + +If you might imagine, +these are regions + +of the protein that are +highly complimentary. + +So there'll be a patch +on one side that's + +a hotspot matching +up with another patch + +on the other protein +that's also a hotspot. + +And it's kind of +an interesting note + +that around these regions +where the hotspots occur, + +there are other amino +acids that exclude solvent + +from the interface. + +And they call that an o-ring. + +So these are some +of the features that + +tend to occur with +protein interfaces. + +So in this PRISM algorithm, +what they do is the following. + +They start off with a +template-- two proteins that + +are known to interact-- and +they define the interface simply + +by close approach of +amino acids in one + +chain to amino +acids in the other. + +So in this case, +shown in these balls + +are regions of the +proteins that interact. + +And then they isolate +the interfacial residues. + +Ignore the rest of the +protein, because we + +said that the parts that +interact in different proteins + +could be homologous even +if the global structures + +of the proteins are not, right? + +So we're going to do our +structural similarity + +calculations purely on +the interface residues + +and not on the entire structure. + +So then with that +template, you can then + +look at lots of proteins +and see whether they + +have any structural match +to pieces that interact. + +So here they've identified +this protein, ASPP2, + +which has structural homology +to I kappa b at the interface. + +Although globally +it's quite different. + +And now, once they have this +potential partner for NF kappa + +b, this ASPP2, +they're going to test + +whether there's a +good structural match, + +whether specifically +in the regions + +that are hotspots-- they have +an algorithm for predicting + +hotspots-- whether the +match is good, whether it's + +sequence conservation +at those hotspots. + +And only then do they +do the refinement + +to do the flexible +refinement of the type + +that we looked at in the +previous lecture, energy + +minimization, and +other approaches + +to figure out what the +best possible structure + +of this complex +would be, and then + +what it's free energy would be. + +So here's their +description of the problem. + +They have template +proteins and targets. + +They do a structure alignment. + +They asked whether it +passes some thresholds. + +These are very, very +fast calculations to do. + +And only if they pass +these fast calculations + +do you do more +detailed calculations. + +And finally, only +if it passes this + +do you do the very +computationally expensive + +refinement. + +And then one critical thing to +remember from this algorithm + +is that it doesn't require +the template and its query + +to be perfectly +matched in structure. + +In fact, the elements of the +structure at the interface + +could come from different +parts of the chain. + +So they don't take into +account the chain order. + +So if I had a beta sheet +structure in one protein that + +looks like this, in my +query these two proteins + +could be very +indirectly connected. + +I don't care that there's a +huge gap in the insertion. + +I just care that locally +at the interface, + +one protein looks a +lot like the other. + +There was a question +in the back. + +AUDIENCE: How do you search +a database for 3d structures? + +Are you just looking +at all the [INAUDIBLE]? + +PROFESSOR: That's right. + +So the question was, +how do you search + +a database for 3D structure? + +You do structural +similarity comparisons + +that are based on +the 3D coordinates. + +The simplest way to do it, +but not the most efficient, + +is to find the rigid-body +superpositions that + +minimize the root mean +squared deviation, which + +was a metric we gave in one +of the previous lectures. + +There are faster things +you can do as well. + +You could imagine that you could +look at certain global features + +of elements of secondary +structure and so on. + +And there's been a lot of work +making those algorithms very + +fast. + +Other questions? + +Good question. + +So they give an +example in their papers + +that starting off with this +known structural complex, + +cyclin-dependent kinase, the +cyclin, and p27, the inhibitor. + +And then looking for +structural matches. + +So we can identify this +potential structure match. + +You refined it, get an +energy of interaction. + +Try another one that has no +global structural similarity. + +Again, once it passes +all the checks, + +you compute the +refinement and the energy. + +And similarly with this side. + +And so from this +initial complex, + +where we had these +two proteins which + +were known to interact in the +PDP they can make predictions + +that these other proteins are +likely to interact even though, + +again, at the global +level, there's + +very little sequence similarity. + +Is that clear? + +OK. + +So the advantage of this +is that it eventually + +does do these structural +refinements that + +allow us to figure out +the best match between two + +potential interacting proteins. + +But that's also its +weakness because that + +takes a lot of +computational time. + +So this other approach called +PrePPI never actually does + +those structural refinements +of the type we talked about + +in the previous lecture. + +So if so, how does it +figure out whether the two + +proteins are likely to interact? + +So this is their schematic, +and we'll go through the steps. + +So you start off with +two query proteins + +that you want to know +if they interact. + +And you do sequence +similarity to a database + +of known structures. + +So you find sequence +homologues to those proteins. + +And so they call +those homology models. + +MA and MB. + +And now they look through the +database for all the structural + +homologues, not +sequence homologues, + +but structural +homologues of MA and MB. + +So they get a +series of neighbors + +that they call NA 1 +through n and NB 1 to n. + +So these are the neighbors +of these homologues. + +And they asked whether +any of these neighbors, + +anything in this row, +anything in this row, + +are known to interact. + +And that potential +interaction then + +could be a model for the +interaction of the query, + +right? + +So far so good. + +Then they do a +sequence alignment. + +They sequence +alignment of MA and MB, + +which are the known structural +homologues of the queries, + +and the two proteins that +are known to interact. + +And so now they've got +this potential model + +for the interaction of the +queries made up of two proteins + +of known structure that have +homologues that are known + +to interact. + +OK? + +So it's two steps removed +from the actual interaction. + +Now, while their +figure says that they + +do a structural +superposition, that's + +not, in fact, what they do. + +If you look at it carefully, +it's a sequence analysis. + +And I'll take you through +the steps in a second. + +So they mean structured +in a rather loose way. + +So they're only doing +sequence comparisons here. + +They're never actually +building a homology model + +for the queries. + +OK + +So this figure comes +from the supplement + +where, for some +mysterious reason, + +they've changed all +the nomenclature. + +So things that previously +were called NA and NB + +have now been called TA and TB. + +Take what you get. + +So this is a pair of +interacting proteins + +where the structure of +the interaction is known. + +And they're structural +neighbors of NA and NB, + +which you don't know whether +they interact or not. + +They identify interacting +residues in this structure. + +That's why it's represented by +these black lines connecting + +blue dots. + +So these are +interacting residues + +from the two template proteins +and neighbors NA and NB. + +And they asked whether the +amino acids in MA and MB + +also are good matches +for this interface. + +And they have a number of +criteria for doing that. + +So they come up +with five measures. + +The first of those measures +is a structural similarity + +between these MA proteins and +the MA and MB and NA and NB. + +Then similarity-- OK, similarity +is the structural similarity. + +Then they asked, how many of the +amino acids at this interface, + +and what fraction of the +amino acids at the interface + +can be aligned? + +So this is a sequence-based +alignment of MA + +and-- well, it's here called TA, +but was previously called MA. + +Just to make life complicated. + +So this is the +sequence-based alignment. + +These are they interacting +residues, all the blue ones + +in the structure of +TA and TB interacting. + +And they asked, what +fraction and what number + +of these amino acids are aligned +in this sequence alignment? + +So here they come +up with a number. + +In this case, I guess, it's +four amino acids in this-- four + +pairs, I should say, of the +amino acids-- one, two, three, + +and four, indicated +by these four lines-- + +are both interacting in the +structure of the complex + +and can be aligned to +sequences in MA and MB. + +And then they use +these other algorithms + +that are based primarily +on machine learning + +looking at protein +interfaces to decide + +whether the sequence of the +amino acids that are going + +to sit at those places +in the interface + +are likely to be residues that +typically occur at interfaces. + +So this is the +kind of statistics + +that I showed you before +from those old papers that + +said 10% of the amino acids +are in these hotspots. + +Certain kinds of amino +acids are predominant there. + +So the number of algorithms, +and they list a bunch, + +that they use to +come up with a score + +to decide whether these +residues, in fact, are + +statistically likely +to be good matches. + +So they have these criteria +and they decide then + +that some fraction of the amino +acids at this interface in MA + +and MB are likely to +be reasonable ones + +to be at the interface. + +So with all that +done, they then use + +all of these different scores +with a Bayesian classifier, + +and we'll talk a +little bit later + +in this lecture and +probably the next lecture + +as well as to what a +Bayesian classifier is. + +But they plug all +those scores in that + +they've derived +from these proteins + +to decide whether +these two proteins are + +likely to interact. + +So the advantage +of this approach + +is it's extremely fast. + +Everything we've talked +about are very, very quick + +calculations. + +Even the structural +alignments are fast. + +The sequence alignments, +of course, are. + +So we get through the whole +database very quickly. + +So they've actually computed the +potential attraction partners + +of every pair of proteins in +various genomes based solely + +on these alignments. + +The disadvantage-- so what's +the disadvantage of this method? + +AUDIENCE: Can't get a +de novo interaction? + +PROFESSOR: We can't get +any de novo interaction, + +so if there's no neighboring +structures that interact, + +they'll never come up with it. + +So that's an important point. + +And then the other problem +is, because it doesn't + +have the structural +refinement, it's + +given up on that +slow calculation, + +so also loses a lot of +potential specificity. + +All the conformational +changes that can occur + +will be lost to an +algorithm like this. + +So we have these two +competing approaches. + +Yes, questions in the back. + +AUDIENCE: Couldn't this method +actually be used as an input + +to, say, a refinement +step, for example? + +PROFESSOR: The +question was, could you + +use this kind of approach as an +input to the refinement step? + +And absolutely one could. + +Is there another +question back there? + +Other questions? + +All right. + +So we're going to take a slight +turn here in the course lecture + +and move away from a purely +computational approach + +and actually look at how +interaction measurements are + +made. + +One of the big changes +of the last decade or so + +is that we've gone from an era +when interactions were measured + +pairwise to interactions +being measured in bulk. + +So through high +throughput measurements. + +And we'll see that that leads +us to some statistical problems + +which eventually bring us back +to some computational issues + +as well. + +So if you want to measure +all the proteins that + +interact in an +organism, turns out + +to be, obviously, +very difficult. + +One big advance that's +helped with this + +is the idea of tagging proteins +and using mass spectrometry + +to figure out what +they interact with. + +So in these two sets +of papers, which + +were some of the early +ones being done in yeast, + +they took one protein at a +time and attached a tag to it. + +And I'll talk about exactly +what those tags are, + +but those are labels +that allow you + +to attach it to a solid support. + +And then by attaching +to a solid support, + +you could then +purify any proteins + +that stuck to protein one here. + +And then after you purify them, +you can run them out on a gel, + +cut them out, and +figure out what + +the identity of those +interacting proteins + +were by mass spec. + +So this sounds very +labor intensive, + +but it's still a lot faster than +anything that came before it. + +And with this +approach, they were + +able to go through +entire genomes, + +proteomes I should +say, and figure out + +all the interacting partners +for very, very large fractions + +of all the proteins there. + +So with this approach, +what kinds of proteins + +do you think are likely +to be false positives? + +Any thoughts? + +Yes. + +AUDIENCE: Proteins +stuck on the column that + +has nothing to do with +interaction [INAUDIBLE]. + +PROFESSOR: Exactly. + +So one thing that can +be quite problematic + +are proteins that +stick to the column + +regardless of which +protein you put there. + +And we'll see an approach +to getting rid of that. + +Other kinds of problems? + +A variant of that. + +Thoughts? + +What about proteins +that tend to stick + +to other proteins +non-specifically, right? + +Those are going to be +quite problematic too. + +And what are the +likely false negatives + +in an approach like this? + +The proteins that really do +interact with the blue one + +but aren't picked up. + +Yes. + +AUDIENCE: Weak interaction +partners [INAUDIBLE] + +PROFESSOR: Weak interaction +partners, things, + +particularly with +short half lives. + +Because you do a lot +of washing, so it's + +going to be dependent +on half-life. + +Very good. + +What else? + +Yeah. + +AUDIENCE: Maybe something +that interacts in tag region? + +PROFESSOR: Something interacts +in the tag region, right. + +So something +interacts right around + +here would be lost because this +would sterically interfere. + +Very good. + +Anything else? + +What about the +concentration of proteins. + +How does that influence +whether they show up here? + +All right. + +So if I have a very high +concentration protein, + +it may interact even though +naturally it doesn't. + +They never see each other. + +They're in different +compartments. + +But when [INAUDIBLE] +and do this. + +But low abundance +proteins are going + +to be quite problematic because +there'll be very little of them + +in these complexes compared to +the high abundance proteins. + +It won't be detected +by this method. + +They will never get to +the mass spec, and so on. + +So we've got both false +positives and false negatives + +in these approaches. + +Now, one of the +things that came up + +was proteins that stick +non-specifically to the column. + +And there was a +clever approach in one + +of these early papers that +got picked up to avoid that. + +And this is called tandem +affinity purification, + +or TAP-tags. + +And the idea is the following. + +We have some gene. + +And we use homologous +recombination-- + +this was done in +yeast where this + +is easy-- to insert +this sequence, which + +codes for the following. + +A piece of protein of +no particular function, + +as far as anyone +knows, a spacer, + +followed by this +calmodulin-binding protein, + +followed by a protease +recognition site, + +and then by protein A. + +So once this protein +gets expressed-- + +and it gets expressed +in it's native levels + +because you're inserting +this into the genome. + +So it's not on an +exogenous promoter. + +It's in its normal position. + +Whatever that protein +was, then has it + +as C terminus all these pieces. + +So how does that help? + +In the purification, we start +with something, IgG IGG, + +that binds to protein +A. So now that's + +what attaches us to +the solid support. + +And attached to +the solid support + +will be all those things +that are nonspecific binders. + +And so if I have some +nonspecific binder that + +just likes my solid +support, it'll be here. + +Nonspecific. + +And if I just acid washed +everything off the column + +and ran my gels with that, +or boiled it off in SDS, + +I would get the +nonspecific protein too. + +But what they do instead +is they instead cleave here + +with a very specific protease +that recognizes this site. + +It's called a tobacco +etch virus protease. + +It has a very long +recognition sequence. + +You can make sure it doesn't cut +anywhere in any other protein. + +And so now, instead of +alluding non-specifically + +with acid or detergent, you +allude specifically with TEV, + +and then this part of the +protein will fall off. + +And then you do a +second purification + +that relies on this +piece of the protein. + +So you pull out only +the things that you + +want that have the CBP, +the calmodulin binding + +protein, by having different +kind of solid support + +that has calmodulin +attached to it. + +And so through this +process, you can get rid + +of a lot of nonspecific binders. + +It doesn't help you with +the false negatives, right? + +You've made the wash +conditions even harsher + +so you're going to +lose more proteins. + +But you'll pick up +fewer false positives. + +And then finally, the last +purification procedure actually + +uses EGTA, which is +a chelating agent. + +So this interaction +between CBP and calmodulin + +depends on calcium. + +EGTA sucks the calcium +out of that interaction. + +And so it's, again, a very +specific way of alluding rather + +nonspecific one, like heat, +salt, acid, or detergent. + +So this has been one technology, +affinity purification + +followed by mass spec, that's +given us a lot of information + +on protein-protein interactions. + +And a computing +technology that's + +also contributed quite a lot +is called yeast two-hybrid. + +So in this approach, +you have a reporter gene + +that normally is not +going to be transcribed. + +It has at a design DNA binding +site, a DNA binding protein, + +and your bait protein. + +And you want to figure +out every protein that + +can interact with this prey. + +So the prey now is attached +to an activation domain. + +If these two proteins +don't interact, + +the activation domain never +gets recruited to this reporter, + +there's no transcription. + +But if the green protein and +the blue protein interact, + +then the activation +domain is going + +to be recruited to +this promoter and it's + +going to turn on transcription, +and then you'll get a signal. + +So what are some of the +advantages of this approach? + +It doesn't require you +to purify anything. + +So it should be +much more sensitive + +to low abundance proteins. + +So that's definitely +an advantage. + +It'll pick up a lot of those +transient interactions. + +You may not get +continuous activation, + +but you'll get +transient activation. + +And if you've set the +conditions up properly, + +you can pick up the +transient activation. + +But it has its own biases, +so none of these techniques + +are going to be perfect. + +It's going to be +biased against proteins + +that don't express well. + +This is, as the name implies, +typically done in yeast. + +So if you have human +proteins and you express them + +in yeast, or plant proteins +that you express in yeast, + +there could be some proteins +that just will not express well + +in that organism. + +What else can be a problem? + +Some proteins don't do +well in the nucleus, right? + +So if you're interested +in interactions + +with membrane +proteins, it's going + +to be very hard to get them +to express in the nucleus, + +and therefore, you'll never +pick up those interactions. + +OK. + +So we've got these two +different technologies-- + +the affinity capture mass +spec and the two-hybrid. + +Questions on those technologies? + +Yes. + +AUDIENCE: Could +another control be + +for the mass spec +purification just + +to subtract out everything +that alludes non-specifically. + +PROFESSOR: The question was, +could you subtract out anything + +that's nonspecific. + +And yes, if you've +got what you might + +call frequent flyers, +proteins that show up + +in every single +purification, then you + +can simply ignore those. + +And that is often done. + +So that'll help you +with things that + +are very nonspecific +for the surface. + +What's more of a +problem are proteins + +that have some affinity +for your protein + +x but are not really +highly specific for it. + +So they tend to bind in +certain kinds of patches. + +Those would be +harder to figure out + +because they won't +stick to everything. + +Good question. + +Other questions? + +All right. + +So we've got these +different technologies. + +What we'd really +like to be able do + +is we know that there are +problems in each approach. + +We'd like to be able to compute +the probability that two + +proteins interact +based on the data. + +So now we're turning back to the +more mathematical computational + +approaches. + +So if we just consider +one experiment-- and we're + +going to talk about +gold standard. + +So what's a gold standard? + +It's a set of proteins that we +have extremely high confidence + +interact because it was analyzed +by some other technology. + +Not two-hybrid, non-affinity +capture mass spec, but much, + +much more direct interactions. + +By physical measurements, +maybe the structural work. + +So the number of +criteria that go into it. + +So we have this +gold standard data + +set where we know the proteins +definitely interact, and we + +have our experiment. + +So clearly anything +in the overlap, + +we can count as true +positives, right? + +We detected it. + +It's in the database +of gold standards. + +And things that are in the +gold standard that we missed + +are obviously false negatives. + +We report them as +non-interacting, + +but in fact they do. + +The question is, how much +of this is true positive? + +Everything that's detected +in the experiment but we + +have no information +for it in the database. + +So that could be for one +of two reasons, right? + +That could be that they +really don't interact. + +Or it could be that +no one's measured it. + +The whole point +of this experiment + +is to find new things. + +So is there any way to estimate +what fraction of all the things + +that are unique to this +experiment are true positives, + +and what fraction +are false positives? + +Those we'd like to +try to figure out. + +Now, if we just +had one experiment, + +that would be very challenging. + +But what happens when +we've got two experiments? + +So we have these two affinity +capture mass spec experiments, + +or maybe affinity capture +mass spec and a two-hybrid. + +So now let's think about +the overlap of those two + +experiments with +the gold standard. + +So I've got this region of +overlap between experiment 1 + +and experiment 2, +and then this region + +that's overlapping +between all three things. + +Experiment 1, experiment +2, and the gold standard. + +So these clearly are +two positives, right? + +They're high confidence +because I picked them up + +in both experiments, and +they're in the gold standard. + +What about all these things +in what I've labeled here + +region 2? + +Well, if we believe that +these two experiments are + +independent of each +other in a rigorous way-- + +so let's say one's a +two-hybrid and one's + +an affinity capture mass spec, +there's no particular reason + +that the false +positives for one would + +be false positives in the other. + +In that case, I can +call this region 2 + +my consensus true positives. + +I have a very high +confidence that these + +are true interactors. + +Everyone buy that? + +Seem reasonable? + +OK. + +So here's where +the trick comes in. + +What fraction of all these +consensus true positives + +are picked up in +the gold standard? + +This ratio, right? + +Region 1 over region 2. + +OK. + +So now I've got this region +of things that are picked up-- + +the true positives from +this experiment, then + +the gold standard. + +And then I've got this region +that's unique to experiment 2 + +and it's going to be some +mix of true positives + +and false positives. + +And the authors of this +paper that are cited here + +make the following argument. + +We're going to assume +that the ratio of I to II + +is the same as the +ratio of III to IV. + +So the fraction of +consensus true positives + +that are picked-- these are +independent experiments. + +So the fraction +of true positives + +that are picked up +in the gold standard + +is going to be constant, +whether they're in the consensus + +or not. + +So the fraction at +ratio of I to II + +is going to be the same +as the ratio of III to IV. + +So by that then, I can figure +out how much of this region + +consists of true +positives and how much + +consists of false positives. + +Everyone buy that? + +Yeah. + +AUDIENCE: Can I check-- +are we not saying + +that the gold standard +represents all true positives? + +PROFESSOR: Correct. + +Well, we're saying that the +gold standard consists of things + +that we know to interact-- + +AUDIENCE: But there may be more. + +PROFESSOR: But +there may be more. + +And the goal of our experiment +is to find those other ones. + +All right. + +So if you accept that premise, +which seems plausible, + +then you can compute what +fraction of all the things + +that are picked up in +each of these experiments + +are likely to be true positives. + +So drum roll please. + +It turns out that the +number's not that high. + +So the fraction of +things in the consensus + +was 347 out of almost 2000. + +And if you do the math +then, what you end up with + +is that the true +fraction in this region, + +for which we have no +data, is 1,123 out of-- + +and the false piece in this +is going to be almost 15,000. + +And they went ahead and +did this for a number + +of different +experiments and computed + +the fraction of derived false +positives for these data-- + +might be a little bit hard +to see on this screen. + +But the numbers range +from 50% false positives + +to, in some cases, over +90% false positives. + +That's a little +disturbing, right? + +So these technologies are good +at picking up interactions, + +but there's reason +to be very skeptical. + +OK. + +So now we've got +a serious problem, + +because how are we +going to figure out + +which of these interactions +to trust when we know + +that a very, very large fraction +of them are false positives? + +So what could you do? + +Well, you could take only +the little bit of overlap. + +You could say, I have that Venn +diagram-- method 1, method 2. + +They did agree on +a bunch of things. + +So I could take only those. + +That obviously +throws away a lot. + +Someone else suggested we could +throw away the sticky proteins, + +right? + +So maybe there are +nonspecific proteins + +that don't show up +in every experiment, + +but they show up in a +very, very large fraction + +of all experiments. + +Maybe I toss those out. + +That's another possibility. + +But what we really +want to do is actually + +come up with a +probability estimate. + +To not have to make +a hard decision, + +but come up with an +estimate of the probability + +that things interact +based on all the data. + +So how do we go +about doing that? + +So first of all, what happens +if you just require a consensus? + +So this plot shows +accuracy and coverage + +of the gold standard for +individual experiments + +with different thresholds for +deciding what's interacting, + +different cutoffs and things. + +So the individual +experiments are shown here. + +And then if you +acquire two methods + +to pick something up, or three +methods to pick something up, + +you can get better and +better in your accuracy. + +This is a log-log plot. + +So if you require +three methods to agree + +before you call something +a true positive, + +you can get up to-- I'm not +sure exactly what this is, + +but 80%, 90% possibly. + +Right? + +But look at where +you at the y-axis. + +You'd only get +about less than 1% + +coverage of the gold standard. + +So that's not a great approach. + +So what we really +want to do, as I said, + +is to try to estimate the +probability that proteins + +interact given all of +our available data. + +And the data could be +specific experiments. + +Say the two different +mass spec experiments + +we just referred to. + +Or as we'll see a +little bit later + +in this lecture and possibly +the next one, other kinds + +of extraneous data that are not +direct physical measurements + +of interaction, but +might give us confidence + +that things interact based +on similarity in annotation, + +or similarity in gene +expression, and so on. + +And we'll get into +details of that. + +OK. + +So to do this, we need +to have a little bit + +of a refresher on +Bayesian statistics. + +So I want to measure +the probability + +that an interaction is true +given the available data. + +Right? + +And I can estimate that based +on the probability of observing + +the data for things +that I know to be true + +and these prior estimates. + +So what's the prior probability +that an interaction is true + +and the prior probability of +observing a particular data + +set. + +Now, this by itself isn't +really that helpful. + +I haven't told you yet how +to calculate any of the terms + +on the right. + +But bear with me. + +If I want to decide +the likelihood + +that a protein interacts-- +how likely is it? + +Is it more likely that +it interacts or not? + +I can compute this ratio. + +The probability +that the interaction + +is true given the data +over the probability + +an interaction is +false given the data. + +That's the likelihood ratio. + +So by this formula, I then +cancel out this probability + +of the data, the prior +probability of the data. + +And if I had a way +of calculating this, + +and we'll get to it in +a second, then if it's + +more likely than not to +be a true interaction, + +I can call it an interaction, +right, if it's less likely. + +So if this ratio +is greater than 1, + +I accept it as a +true interaction. + +If this ratio is less +than 1, then I reject it. + +OK. + +So now our challenge +is to figure out + +how to compute these terms. + +One more thing to note +is if all I want to do + +is be able to rank every +interaction by this likelihood + +ratio, rather than coming +up with a hard threshold, + +then I actually don't +need all these terms. + +So this is the likelihood ratio. + +I can convert it to a log space. + +So it's going to be the +sum of these two terms. + +And if I'm simply +ranking everything + +by this log likelihood +ratio, this term + +is the same for +every interaction. + +It's just composed of +prior probabilities. + +So it's not going to +affect the ranking at all. + +Any questions on that? + +Is that clear? + +Good. + +So if I just want to come +up with a ranking function, + +all I need to do-- +all-- I need to do + +is to be able to estimate +the probability of observing + +data for true interactions and +the probability of observing + +that set of data for +false interactions. + +Everybody buy that? + +Yes, please. + +AUDIENCE: When you say +that prior probability is + +the same for all +interactions, we're + +saying we're assuming the same +prior probability for all, + +or is this [INAUDIBLE]? + +PROFESSOR: That's +its definition. + +We mean, what is the prior +probability that proteins + +interact versus the +prior probability? + +So it's independent of the +proteins that we're looking at. + +Other questions? + +All right. + +So we need a way of +computing this piece + +of all the things +we've looked at before. + +So how do we get an estimate +of the probability observing + +a particular +configuration of the data? + +Meaning, I detect +it in experiment 1 + +and not in experiment +2, but in experiment 3. + +What's the probability of that +given it's a true interaction? + +So that's what we're going +to dive into right now. + +OK. + +So one thing we could +do to make life simpler, + +and then we'll remove +this simplification later, + +but let's, for the time being, +assume that all of my data + +are independent. + +So the two-hybrid is going +to have completely different + +mistakes than the affinity +capture mass spec. + +So those two data +sets are going to be + +completely independent +of each other. + +So I can write this as a product +of a particular observation-- + +a particular mass +spec experiment + +and a particular two-hybrid +experiment for true attractions + +and false interactions. + +So it's the product +of the probability + +that a particular experiment +would detect an interaction + +if the interaction is +true over the probability + +that that particular +experiment would detect it + +if there was no interaction. + +I'm just going to multiply +all of those probabilities. + +Yes. + +AUDIENCE: [INAUDIBLE]. + +This is one interaction pair? + +PROFESSOR: That's right. + +AUDIENCE: And you +take the product + +over all the interaction +pairs within one + +run of the experiment. + +Is that correct? + +PROFESSOR: If I +want to determine + +whether a particular +interaction pair-- + +I want to compute +this log likelihood + +ratio, or this, +actually, ranking ratio, + +because I've thrown +away the priors. + +I want to compute this ranking +ratio for a particular pair. + +So I've got protein +A and protein B. + +And I want to determine +whether I believe + +it to be more likely +to interact or not, + +and rank it with all +the others, right? + +So I'm doing this for +a pair of proteins now. + +So far so good? + +Now, for that pair +of proteins, I + +have a series of observations, +or lack of observations, right? + +I have a whole bunch +of experiments. + +This experiment detected +it, that experiment + +didn't detect it, this one did. + +So what's the probability +of these proteins-- + +these A and B really interact +given that yes, no, yes + +in my experiments? + +And then for new protein, +it might be no, no, yes, + +and what I want to figure out +the probability for this pair. + +AUDIENCE: So is the scale +of the big letter M, + +is it on the order of like 10 +experiments, 100 experiments, + +or thousands of experiments? + +PROFESSOR: Ah. + +So the question is, +what's the scale of this. + +So obviously, that's going to +depend on what kind of data + +I bring in, but in +these cases, it's small. + +So we have a handful of these +high throughput experiments + +over entire genomes +and proteomes. + +So there's not to be a lot. + +So in some of +these early papers, + +there were four +interaction experiments + +that they were looking at. + +Now the numbers might +be a little bit bigger, + +but not significantly greater. + +All right. + +So now to compute this, we +need a set of gold standards. + +But now we don't just need gold +standard positive interactions, + +proteins that we know +really do interact. + +We also need proteins that we +know really don't interact. + +Because I want to compute the +probability of an observation + +given that some interaction +is definitely wrong. + +So precisely how I +compute these terms + +is going to depend +on the kinds of data. + +The experiments I've +just been talking about, + +these high throughput +mass spec, which + +were the ones which we looked +at the ratio of the consensus, + +true positives, and estimated +that 96% of all the data + +were possibly in error. + +The details of how to do +those calculations are here. + +I leave you to look that +up if you're interested. + +But now what we're +going to do is + +we're going to see how, if +we were to rank interactions + +based on this term, +we can avoid having + +to throw out most of our data. + +So we said if we require all +the experiments to agree, + +we're going to have +very, very low coverage. + +Now we're instead going +to rank everything + +based on this likelihood +ratio, or something + +derived from the +likelihood ratio. + +So in this paper +where they were simply + +looking at the +protein-protein interaction + +data sets to compute +these interactions, + +they ranked everything based on +that ranking function we just + +described. + +And then as you +vary your threshold, + +you can figure out how many +true positives you have + +and how many false positives +you have in the gold standard. + +True interactors and +false interactors. + +And you can compute +this curve, right? + +For any particular value +of that ranking ratio, + +what's my sensitivity and +what's my specificity? + +Are you clear what +this plot means? + +And here they've +plotted the values + +for individual experiments. + +And this is the value for +an independent database + +of gold standard interactions. + +And so now, where +do they come up + +with their true positives +and their false positives? + +A lot of this is going to depend +on how representative those + +are. + +And all these numbers +are subject to revision + +if you decide that the true +positives and false positives + +that people are using +are not accurate enough. + +So they used two well annotated +databases of interactions. + +One from MIPS and one from SGD. + +And you can play those +off against each other + +as the database +of true positives. + +In some ways, that's +the easier thing + +because people like to report +that proteins interact. + +They tend not to like to report +the proteins don't interact. + +You don't see a lot of +nature papers saying protein + +x doesn't interact +with protein y. + +So how are you going +to figure out, then, + +what are your true negatives? + +So the strategies +that they used-- well, + +one possibility is they're +annotated to be in complexes, + +and those complexes are +different from each other. + +That's not bad, right? + +But it's not a guarantee either. + +Or this is a little bit better. + +They're annotated to be in +different parts of the cell. + +Of course, if those +annotations aren't perfect, + +low concentrations, you +could still be wrong. + +Or that they have +anti-correlated gene + +expression. + +I kind of like this one. + +So it's one thing to be not +correlated, but if you're + +anti-correlated, seems +pretty suggestive + +that these two proteins are +never in a complex together. + +Again, it's no guarantee +because, as we'll talk about + +in some detail later, +RNA levels are not + +very good predictors +of protein levels. + +But if you apply enough +of these criteria, + +you can come up with +a set of proteins + +that you have fairly +high confidence really + +don't interact. + +You combine that with +the databases of proteins + +with very high confidence +that they do interact, + +and you can get the true +positives and false positives + +that you need for this analysis. + +all right. + +So that's a way of +combining some information. + +We're going to see a +generalization of that + +called Bayesian networks. + +We've mentioned this +already in at least + +two different +contexts, and it'll + +come up again later +in the course as well. + +So these are very +general methods + +for reasoning probabilistically. + +We will see them +in the context here + +of predicting interactions. + +We'll see them later in the +context of gene regulation + +and signaling as well. + +What we fundamentally need +to do a Bayesian network + +is a graphical structure that +represents our understanding + +what the relationship is +between causes and effects. + +And a set of +probabilities that allow + +us to compute things +on this network. + +We'll show you examples where +those networks are derived + +from our prior understanding +of the problem, + +but also ones where the +structure of the network + +is learned from the data. + +And we're going to see +two primary contexts. + +First we have this question +of whether proteins interact. + +That's what we've just +been talking about. + +So here are four experiments, +the in vitro pulldown + +experiments and yeast +two-hybrid experiments, + +that give us relatively +independent information + +about whether proteins interact. + +And we're going to +look at a paper that + +used those data with +a Bayesian network + +to compute the probability that +two proteins really do interact + +based on the combination +of all the data, + +rather than throwing out +anything that doesn't fall + +in the overlap, which could +be a very, very small number. + +And then later on +we'll see examples + +of using Bayesian networks to +understand biological networks. + +So this might be a set +of transcription factors + +that are regulating a set of +differentially expressed genes. + +And the structure of +the graphical network + +for a Bayesian network +has a lot of similarities + +to the way we normally +think about transcriptional + +regulatory networks. + +So there's sort of a +natural way of transferring + +our regulatory problem into +a graphical network problem. + +But we're going to focus +on these prediction + +problems for protein-protein +interactions first. + +Now, if I just want to compute +the probability of detecting + +an interaction in various +experiments, given that it's + +true or false, I +could explicitly + +compute that probability. + +And we saw examples +of that just now. + +But some of these +Bayesian network problems + +become much, much +too large to do that. + +This is a little tiny +piece of a Bayesian network + +that is supposed to +represent I believe + +it's transcriptional +regulatory network. + +You could never possibly +write down all of the terms + +in this probability, where every +node could, in principle depend + +on every other node +in the network. + +It would just be a +ridiculously large problem. + +In fact, how large would it be +if I've got N binary variables, + +my gene is on or off, my +interaction is true or false, + +I have 2 to the N +possible states? + +Right? + +And the only constraint +I have, in principle, + +is that all the probabilities +have to add up to one. + +So I have 2 to the N minus 1. + +2 to the N minus 1 possible +variables that I need to set. + +So that's a ridiculously +large number in most contexts. + +So how do Bayesian networks +help us solve this problem? + +Well, we represent +our understanding + +of the problem in a +graphical structure + +where we have +causes and effects. + +And there'll be a direct arrow +from a cause to an effect. + +I don't always know the cause. + +So in our context, +we were trying + +to figure out whether +two proteins interact. + +What do we measure? + +We actually don't +measure interactions. + +We measure the result of a +particular experiment, which + +is a combination of +whether interacted + +and all sorts of noise +that we've just discussed. + +So the effects that we observe +are detected in experiment one + +or detected in experiment two. + +The cause is, did +it interact or not? + +So the cause is hidden, +the effects are observed. + +Now, in the case we +were looking at before, + +we treated all +these probabilities + +as being independent. + +But we might know something +about the structure + +of our experiments, the kinds +of experiments we're doing, + +that might lead us to have +a different structure. + +So we could have an +interaction that gives rise + +to all different kinds of data. + +But depending on whether +the protein's a membrane + +protein or highly +expressed, it might + +influence the results +of certain experiments + +and not influence the +results of others, right? + +So like a two-hybrid +would be very biased + +by which one of these? + +The membrane, right? + +And then the affinity +capture mass spec + +could be very +influenced by proteins + +that are expressed at very +high levels or very low levels. + +If we assume that all the +interactions are independent, + +then we multiply probabilities. + +And we'll go into +more detail, but this + +is what we're looking +at up until now. + +In cases where we believe that +all the observations are not + +independent, then +we're not going + +to simply multiply things. + +We'll see there's +a more precise way + +of computing the probabilities. + +Now in this case, I've drawn +the graphical structure + +because I believe that +I know what's going on. + +But in the more general +case that we'll look at, + +we'll actually derive the +structure from the data. + +One of the nice things +about Bayesian networks + +is that it removes the +need to have all 2 to the N + +minus 1 possible parameters, +because it tells us there + +are certain +independence conditions. + +So node is independent of its +ancestors given its parents. + +What does that mean? + +If I'm trying to reason +about the expression of one + +of the genes down here, and I +know that this transcription + +factor is on, I +don't really care + +what the probability is +that any particular parent + +of that transcription +factor is on, right? + +So I don't need to know anything +of transcription factor B1 + +if I know the state of B2. + +If this is on, then +that's the only thing + +that's going to affect whether +it's turning on these genes, + +regardless of what the +activation state of its parent + +was. + +Is that clear? + +Yes. + +AUDIENCE: The +slide's saying TF B1. + +[INAUDIBLE] TF B2? + +It says TF A1. + +PROFESSOR: Yeah, sorry. + +That should say TF B1. + +Thank you. + +OK. + +So we'll do a little example. + +It's admission season +both for graduate school + +and undergraduate. + +So let's do a little +toy example where + +we're going to get rid of +the admissions committees + +and just do +automated admissions. + +So we're going to collect +various data about students, + +and then we're going to +build a Bayesian network. + +And that network +is going to decide + +whether to admit students +into this simplified version. + +And the only information that +will go into our decision + +will be the grades on the +transcript and the GREs. + +Hopefully that's not the case. + +And we believe +that certain things + +influenced your +grades and your GREs. + +Whether or not the +student is smart + +certainly should +have some influence, + +but also the great +inflation at their school + +will have some influence. + +So a prediction problem +in a Bayesian network + +is going from the +causes to the effects. + +So if I want to predict +whether a student's admitted, + +I only need to look upstream. + +So we want to predict-- we +observe the things on the top. + +Say, grades and +GREs, and we want + +to predict whether this student +should be admitted or not. + +There's another problem called +an inference problem, which + +is when we observe +the effect and we + +want to make inferences +about the causes. + +So an example of that would +be, you apply for an internship + +and they say, oh, +she's a student at MIT. + +I bet she's smart. + +Right? + +They're doing an +inference problem. + +We'll leave it for you to decide +whether you and your colleagues + +are as smart as everyone +thinks, but hopefully you are. + +OK. + +So we've got these two +different kinds of problems. + +We've got prediction +problems from top to bottom, + +and inference problems +from bottom to top. + +And we're going to talk about +conditional probability. + +So if I've got some very +small piece of this network + +with just two nodes, +I could write out + +all the possible probabilities +for any pair of those nodes. + +So the probability that +a student is not smart + +given that that student has +low grades, the probability + +that the student is not smart +given that the student has + +good grades, and so on, for all +possible pairwise comparisons. + +Or I could write this as a +conditional probability, which + +tends to be an easier way +to think about the problem. + +What's the conditional +probability of a student + +being smart given that +they've got good grades + +or given that they +have bad grades? + +They have the same information. + +For this one, I need +additional information + +about the total probability of +students being smart or not. + +And the total number of +variables, as I said, + +in either case is the same. + +So these are completely +interchangeable, + +but it's a lot easier to reason +with conditional probabilities + +than with the joint +probability tables. + +Those we'll see in a second. + +So as I've said, you don't +need a full probability table + +for a Bayesian network. + +You don't need two N to +the minus 1 variables. + +And the fundamental +reason for that + +is that the joint +probability is only + +going to depend on the parents. + +So in this toy example, +the GRE scores over here + +are not dependent +on grade inflation. + +Now, that all +hopefully makes sense. + +Questions? + +Bayesian networks get +a little murky next, + +so I'm going to try to +give you into-- oh, yes. + +Question, please. + +AUDIENCE: You said that +the parents don't affect + +their children, but if grade +inflation affects the grades, + +how does that +influence-- will that + +influence the grade [INAUDIBLE]? + +PROFESSOR: Sorry, can you +say the question again? + +AUDIENCE: I guess +I'm just confused + +by this particular example. + +What do you mean by +the joint probability? + +The joint probability of what? + +PROFESSOR: So if I +want to figure out + +the probability of some +particular configuration of all + +the nodes in my network, +I don't necessarily + +need to consider +all possibilities. + +Because for example, +if I want to consider + +all of the joint +probability samples + +with settings for the GREs, +whether the student had + +good GRE scores +or not, that's not + +going be influenced by the +student's school's grade + +inflation policies. + +AUDIENCE: But wouldn't the +grades be influenced by the-- + +PROFESSOR: But the +grades would be. + +That's right. + +So some of the +variables I can remove + +and others-- some of the +joint probability statements + +I don't need to worry +about and others I do. + +And which ones I +need to consider + +is determined by +the graph structure. + +Yes. + +AUDIENCE: How is the graph +structure determined? + +PROFESSOR: OK. + +So how is the graph +structure determined? + +So it's determined +in one of two ways. + +I can draw it in advance because +I believe that I know something + +about my setting, I believe +that these data are independent. + +Then it has that +structure like this. + +Cause and a bunch of +independent effects. + +Or perhaps I claim to know that +actually two of these things + +have a common parent as well. + +In some cases I know. + +We'll also talk about how +to learn the structure + +from the data, which is +the more common setting + +in regulatory networks. + +So in these kinds +of problems when + +trying to decide +how to integrate + +different proteomic data +sets, typically people + +make arbitrary decisions +about what the structure + +is based on their +knowledge of the system. + +But if you're trying to figure +out de novo which proteins + +interact with which, which +proteins regulate which genes, + +then you have to learn +it from the data. + +And we'll talk about how +to do that in a second. + +Great questions. + +Any other questions? + +Anything in the quiet +half of the room? + +OK. + +So as I said, this +part of it, I think + +you can usually +come up with cases + +that give you fairly +good intuition. + +One of the things that is true +in these Bayesian networks + +which most people find a +little bit surprising at first + +is something called +explaining away. + +So let's look at this +Bayesian network. + +I go outside and I +detect that things + +are slippery on the grass. + +So that could be for +a lot of reasons, + +but one possible reason +is that the grass is wet. + +OK. + +What are the causes of +the grass being wet? + +Well, it could have +rained or the sprinklers + +might have been on. + +And depending on this +as an example-- so + +a lot of the Bayesian networks +were developed in Stanford + +by Judea Pearl and colleagues. + +And of course, in California +it doesn't rain that often. + +So there the season is a strong +determiner of these things. + +Not so much around here. + +So in this example +that they like to do, + +so does the +probability that it's + +raining depend on whether +the sprinkler is on or not? + +Now, the answer +should be no, right? + +I mean, in reality, when +you think about-- there's + +no causal relationship +between the sprinkler being on + +and the rain. + +But in fact, when we're +reasoning over these networks, + +we actually are influenced. + +In a probabilistic model, +if I know that it's raining, + +and I know the grass +is wet, then what + +do I think about the +sprinkler being on? + +Do I think it's just as likely? + +No, I think it's +less likely, right? + +If I go outside and see the +grass is wet, there are clouds, + +the rain is coming +down, is the sprinkler + +likely to be on or not? + +It's likely to be off, right? + +So there's no +causal relationship, + +but there's the probabilistic +relationship through the graph + +structure. + +And that's called +explaining away. + +And you can take a whole +course on how to understand + +which relationships you +can detect and which not. + +This is not the place +to try to go into that, + +but I hope you'll be +familiar with this problem. + +And I'll try to give +you a toy example that + +makes it a little bit +more obvious in terms + +of the equations +where this comes from. + +So imagine this very silly game +where we play, we toss coins. + +We toss a coin twice. + +And if it turns up heads +both times, you get a point. + +If it turns up tails both +times, you get a point. + +But if one's a head and one's a +tail, you don't get any points. + +Now, does the probability that I +tossed a head on the first time + +depend on whether I toss +a tail on the second time? + +So causally, +obviously not, right? + +First of all, it +happened earlier in time. + +And secondly, the coin tosses +are completely independent. + +But what happens when +I know the outcome? + +What if I know +what score you got? + +So if I know your score, +then is the probability + +that I tossed the +heads on the first time + +independent of whether I got +a tail on the second time? + +What do you think? + +How many people think +it is independent then? + +How many people think +it's not independent. + +Very good. + +It's not independent. + +And obviously, here's +the math to prove it, + +but your intuition +does the same thing. + +So what's the probability +that I tossed a head + +on the second time +given that I got a one, + +I scored, and I tossed a +tail on the first time? + +Obviously, it's zero, right? + +So here's the +probability of getting + +a head in the first +time and scoring one, + +and tails on the second +time is exactly zero. + +So that's called +explaining away. + +You can reduce your +belief in certain parents + +based on what you know +about the children. + +Think of this coin toss +example or the rain + +in California and +the sprinklers. + +All right. + +So as this come +up several times, + +how do we obtain the +Bayesian network structure? + +There are two problems that +we need to be able to solve. + +We need to be able to +learn the structure, + +and we need to be able to +learn these probability tables. + +If we know structure, how +do we get the probabilities? + +Well, we need to identify +some objective function we're + +going to try to optimize, +and then choose values + +for all probability +distributions that + +optimize that +objective function. + +And that's the +kind of thing we've + +been doing all along, just +like in the Gibbs sampler. + +We need some objective +function or protein structure. + +We need some objective +function that we're + +going to try to optimize. + +So there are two common +ones that are used a lot. + +There's maximum likelihood +and the maximum posterior. + +So maximum likelihood is defined +as the set of param-- theta + +is all the parameters, all +the probability distributions, + +the probability of getting a +score of one given that you had + +heads and tails, +whatever it may be. + +The probability of +getting admitted + +given that you had certain +GREs and certain grades. + +So we want to find +the set of parameters, + +all those probability +distributions, that + +maximize this. + +The probability of the +data, our training data, + +given those parameters. + +That's a pretty obvious one. + +And the maximum posterior +includes some of our beliefs + +about the prior +probability of the data + +and the prior probability +of the parameters. + +This is a little +bit less intuitive + +because you have +to ask, well, where + +do those numbers come from? + +And that, again, is a +whole course unto itself. + +OK. + +Now, how do you find +these parameters? + +Again, it's the kinds +of search problems + +that we've looked at before, +various kinds of hill climbing. + +So gradient descent, +expectation maximization, + +Gibbs sampling, which +you've looked at explicitly. + +And again, the full +details of how to do that + +are outside of our scope today. + +OK. + +So in our example of +this coin toss game, + +we would use one of +these two functions + +to try to decide what's +the probability of getting + +heads or tails for +any given score. + +That's what the kinds +of parameters are. + +Now, the structure +problem actually + +turns out to be +really, really hard, + +because there are a very +exponentially large number + +of potential structures +to draw from. + +And unless you've got +some prior knowledge, + +it can be impossible, depending +on how much data you have, + +to actually build +this structure. + +So there are many algorithms +that have been proposed. + +And a lot of our +settings, we're going + +to use some kind +of prior knowledge + +to reduce the search space. + +So if we're trying to talk +about transcriptional regulatory + +networks, it's very common +to assume that there are only + +some kinds of nodes that can be +causes and other kinds of nodes + +that can be effects, right? + +So in gene expression +it would be effect, + +and then you would +limit your causes + +to only be +transcription factors. + +It would generally be signaling +molecules or something + +like that, and not allow all +20,000 genes to be causes + +and all 20,000 +genes to be effects. + +So there are lot of +resources to learn more + +about Bayesian networks. + +As I said, you can have +whole courses on this. + +I think there are a lot of +good tutorials at this website. + +I've also put in the notes +a little toy example for you + +to work through all the +probabilities, which I think, + +in the interest of time, we +won't go through in detail. + +All right. + +So to motivate what we're going +to do in the next lecture, + +I just want to talk +about other kinds of data + +that you could bring to bear +on this problem of predicting + +which proteins interact. + +We'll see, then, +how that gets fed + +into an interaction +Bayesian network + +to make the predictions. + +So we've talked about affinity +capture and two-hybrid, + +but what other +kinds of data could + +we use to predict the +probability interaction? + +Well, one thing you could use +would be gene expression data. + +And the idea is that if +two proteins interact, + +they should be present in the +cell at the same time, right? + +So we talked about +this a little bit. + +If they're +anti-correlated, it seems + +very unlikely they interact. + +What about if they're +correlated, but not perfectly + +correlated? + +So here's a plot that shows +a histogram of proteins that + +are known to interact, proteins +that are known not to interact. + +So empty circles are known +interacting proteins, + +the dark circles are +non-interacting proteins, + +and the other ones are based +on the experimental data. + +And the distance here +is the difference + +between expression profiles. + +And we'll talk in coming lecture +about exactly how to compute + +distance between +expression profiles. + +But the further to the right +it is, the less similar + +the expression profiles +are across large data sets. + +So what you see +is the interacting + +proteins tend to be shifted +more to the left, more + +similar expression profiles +than the non-interacting ones. + +But what do you +notice about this? + +There's no way to +draw a line and say, + +everything to the right +of this is in one class + +and everything to the +left is another, right? + +So by itself, it's not +going to get us very far. + +There are plenty of +non-interacting proteins + +that have very highly correlated +gene expression and plenty + +of interacting proteins +that have poorly + +correlated gene expression. + +So it's a trend, not a rule. + +Now, what about evolution? + +So if I look over many, many +organisms, I might expect what? + +The proteins that +interact with each other + +are going to appear in +the same species, right? + +So let's look at +these two cases. + +We've got a bunch of-- +eight different genomes. + +And I've got gene 1 and gene 2, +which I suspect might interact, + +and gene 3 and gene 4, which +I suspect might interact. + +Now, looking at +these two patterns + +of evolution, which one +do we have more confidence + +in that it interacts? + +The red one or the green one? + +So what do we notice about +the difference between them? + +What's true of the red one +compared to the green one? + +Yeah. + +AUDIENCE: The red one is only +in one branch of the tree. + +PROFESSOR: The red one is +only one branch in the tree + +and the green one +is scattered across. + +So let's take a vote. + +Do we believe that +the red one is + +better evidence of +interaction or the green one + +is better evidence +of interaction? + +Red? + +Green? + +Can I have an advocate of green. + +Someone explain their rationale? + +Anyone in the quiet +side of the room? + +All right, Ed. + +AUDIENCE: Because red is only +on one branch of the tree, + +I'd expect that +they're naturally more + +correlated with each other. + +They have less-- +they appear together + +in [INAUDIBLE] so I'd +expect [INAUDIBLE]. + +PROFESSOR: OK. + +So the argument is that red only +occurs in one part of the tree. + +And so there could be a +very simple explanation + +for all the reds being in one +part of the tree and one not, + +which would be a single +loss and gain event. + +Right? + +Somewhere early +on, perhaps here, + +I gain those two proteins. + +And then they're inherited +throughout the genome, + +like most of genes get +inherited throughout the genome. + +Whereas here, we've +got independent events + +of gain and loss. + +And at each one of these +independent events, + +we're getting them +moving jointly, either + +in or out of the genome. + +So there's more +evidence for green + +to be interacting than red. + +Everyone buy that? + +Even some of the +advocates of red? + +Questions? + +Yes. + +AUDIENCE: Could there be a +way of either objectively + +or mathematically +[INAUDIBLE] that way, + +or is it just the +reasoning [INAUDIBLE]? + +PROFESSOR: One can do +the statistics on it + +with known ones, right? + +I think that's +probably the best way. + +And we'll actually see that +in one of these papers that + +uses-- well, +actually, now I don't + +recall whether they +use this co-evolution. + +But yeah, there are +plenty of papers + +that actually have done +the statistics on that. + +So it is supported. + +And a related kind +of question is + +what's called the +Rosetta Stone approach. + +Unfortunately, of +the term Rosetta + +gets used far too much +in computational biology. + +So this has nothing to +do with the other Rosetta + +that we've been talking about. + +And this has to do +with how often you + +find the same pair of genes in +the same genome versus split up + +in different genomes. + +OK. + +So what we're going to +look at next time then + +is an approach that +combines these kinds of data + +with the protein interaction +physical measurements + +through the two-hybrid and the +affinity capture mass spec that + +actually uses the Bayesian +networks we talked + +about this time to predict +whether two proteins are + +likely to interact based on +all of the available data. + +These evolutionary arguments, +the [? sentiality ?] arguments, + +and then the interaction data. + +Any final questions? + +OK, see you next time. \ No newline at end of file diff --git a/CxAkraYlBuE.txt b/CxAkraYlBuE.txt new file mode 100644 index 0000000000000000000000000000000000000000..2e6157da2bcc79b50d0bdeb3293f6f64f8822143 --- /dev/null +++ b/CxAkraYlBuE.txt @@ -0,0 +1,10067 @@ +align:start position:0% + +we are + + align:start position:0% +we are + + + align:start position:0% +we are +we are going to be leaving the territory + + align:start position:0% +we are going to be leaving the territory + + + align:start position:0% +we are going to be leaving the territory +of uh some of some of you have had high + + align:start position:0% +of uh some of some of you have had high + + + align:start position:0% +of uh some of some of you have had high +school chemistry we're going to be + + align:start position:0% +school chemistry we're going to be + + + align:start position:0% +school chemistry we're going to be +starting to leave that territory + + align:start position:0% +starting to leave that territory + + + align:start position:0% +starting to leave that territory +and get into some of the things i talked + + align:start position:0% +and get into some of the things i talked + + + align:start position:0% +and get into some of the things i talked +about + + align:start position:0% +about + + + align:start position:0% +about +before that you may have never seen so + + align:start position:0% +before that you may have never seen so + + + align:start position:0% +before that you may have never seen so +for example + + align:start position:0% +for example + + + align:start position:0% +for example +um today we'll be talking about + + align:start position:0% +um today we'll be talking about + + + align:start position:0% +um today we'll be talking about +semiconductors + + align:start position:0% +semiconductors + + + align:start position:0% +semiconductors +right and what happens when you take all + + align:start position:0% +right and what happens when you take all + + + align:start position:0% +right and what happens when you take all +these atomic orbitals + + align:start position:0% +these atomic orbitals + + + align:start position:0% +these atomic orbitals +and you put them into a solid um + + align:start position:0% +and you put them into a solid um + + + align:start position:0% +and you put them into a solid um +and and then by the end of the week + + align:start position:0% +and and then by the end of the week + + + align:start position:0% +and and then by the end of the week +we'll talk about metals + + align:start position:0% +we'll talk about metals + + + align:start position:0% +we'll talk about metals +and then next week we're going to talk + + align:start position:0% +and then next week we're going to talk + + + align:start position:0% +and then next week we're going to talk +about crystals right so that's what's + + align:start position:0% +about crystals right so that's what's + + + align:start position:0% +about crystals right so that's what's +coming + + align:start position:0% +coming + + + align:start position:0% +coming +before we get into uh uh um + + align:start position:0% +before we get into uh uh um + + + align:start position:0% +before we get into uh uh um +semiconductors and and solids + + align:start position:0% +semiconductors and and solids + + + align:start position:0% +semiconductors and and solids +there's one type of bonding we covered + + align:start position:0% +there's one type of bonding we covered + + + align:start position:0% +there's one type of bonding we covered +but i didn't put the stats up on the + + align:start position:0% +but i didn't put the stats up on the + + + align:start position:0% +but i didn't put the stats up on the +on the column so i just wanted to kind + + align:start position:0% +on the column so i just wanted to kind + + + align:start position:0% +on the column so i just wanted to kind +of make sure that we + + align:start position:0% +of make sure that we + + + align:start position:0% +of make sure that we +finish that and that was hydrogen + + align:start position:0% +finish that and that was hydrogen + + + align:start position:0% +finish that and that was hydrogen +bonding + + align:start position:0% +bonding + + + align:start position:0% +bonding +and there's a little video you know + + align:start position:0% +and there's a little video you know + + + align:start position:0% +and there's a little video you know +water + + align:start position:0% +water + + + align:start position:0% +water +we're not going to go into all the + + align:start position:0% +we're not going to go into all the + + + align:start position:0% +we're not going to go into all the +amazing properties of water but if + + align:start position:0% +amazing properties of water but if + + + align:start position:0% +amazing properties of water but if +you're interested + + align:start position:0% +you're interested + + + align:start position:0% +you're interested +this is a really cool website that talks + + align:start position:0% +this is a really cool website that talks + + + align:start position:0% +this is a really cool website that talks +about all the anomalies + + align:start position:0% +about all the anomalies + + + align:start position:0% +about all the anomalies +of water and and many of water's + + align:start position:0% +of water and and many of water's + + + align:start position:0% +of water and and many of water's +properties + + align:start position:0% +properties + + + align:start position:0% +properties +are anomalous and much of the reason for + + align:start position:0% +are anomalous and much of the reason for + + + align:start position:0% +are anomalous and much of the reason for +that + + align:start position:0% +that + + + align:start position:0% +that +is the last type of bonding we talked + + align:start position:0% +is the last type of bonding we talked + + + align:start position:0% +is the last type of bonding we talked +about intermolecular bonds we talked + + align:start position:0% +about intermolecular bonds we talked + + + align:start position:0% +about intermolecular bonds we talked +about + + align:start position:0% +about + + + align:start position:0% +about +last friday which is the hydrogen bond + + align:start position:0% +last friday which is the hydrogen bond + + + align:start position:0% +last friday which is the hydrogen bond +so remember + + align:start position:0% +so remember + + + align:start position:0% +so remember +our table i just wanted to fill out the + + align:start position:0% +our table i just wanted to fill out the + + + align:start position:0% +our table i just wanted to fill out the +table because i didn't fill out the + + align:start position:0% +table because i didn't fill out the + + + align:start position:0% +table because i didn't fill out the +table right + + align:start position:0% +table right + + + align:start position:0% +table right +that's the type of bond and the model + + align:start position:0% +that's the type of bond and the model + + + align:start position:0% +that's the type of bond and the model +was some kind of + + align:start position:0% +was some kind of + + + align:start position:0% +was some kind of +you know electronegative um + + align:start position:0% +you know electronegative um + + + align:start position:0% +you know electronegative um +it was some kind of highly + + align:start position:0% +it was some kind of highly + + + align:start position:0% +it was some kind of highly +electronegative atom like a + + align:start position:0% +electronegative atom like a + + + align:start position:0% +electronegative atom like a +was oxygen or nitrogen or fluorine + + align:start position:0% +was oxygen or nitrogen or fluorine + + + align:start position:0% +was oxygen or nitrogen or fluorine +so that you drew a lot of charge off of + + align:start position:0% +so that you drew a lot of charge off of + + + align:start position:0% +so that you drew a lot of charge off of +that hydrogen + + align:start position:0% +that hydrogen + + + align:start position:0% +that hydrogen +and you left it uh with a really strong + + align:start position:0% +and you left it uh with a really strong + + + align:start position:0% +and you left it uh with a really strong +delta plus + + align:start position:0% +delta plus + + + align:start position:0% +delta plus +so that it could then bond to some + + align:start position:0% +so that it could then bond to some + + + align:start position:0% +so that it could then bond to some +other atom it might be the same atom by + + align:start position:0% +other atom it might be the same atom by + + + align:start position:0% +other atom it might be the same atom by +the way it was in the cases that we + + align:start position:0% +the way it was in the cases that we + + + align:start position:0% +the way it was in the cases that we +you know that we talked about i'll just + + align:start position:0% +you know that we talked about i'll just + + + align:start position:0% +you know that we talked about i'll just +use the same atom because we used + + align:start position:0% +use the same atom because we used + + + align:start position:0% +use the same atom because we used +hf and h2o so then it would be the o or + + align:start position:0% +hf and h2o so then it would be the o or + + + align:start position:0% +hf and h2o so then it would be the o or +the f + + align:start position:0% +the f + + + align:start position:0% +the f +but it's to a lone pair right on that + + align:start position:0% +but it's to a lone pair right on that + + + align:start position:0% +but it's to a lone pair right on that +atom + + align:start position:0% +atom + + + align:start position:0% +atom +that that was the hydrogen bond and the + + align:start position:0% +that that was the hydrogen bond and the + + + align:start position:0% +that that was the hydrogen bond and the +range + + align:start position:0% +range + + + align:start position:0% +range +of attraction is in + + align:start position:0% +of attraction is in + + + align:start position:0% +of attraction is in +kilojoules per mole of bonds + + align:start position:0% +kilojoules per mole of bonds + + + align:start position:0% +kilojoules per mole of bonds +is something like let's see 10 + + align:start position:0% +is something like let's see 10 + + + align:start position:0% +is something like let's see 10 +to 40. so it's pretty strong you know + + align:start position:0% +to 40. so it's pretty strong you know + + + align:start position:0% +to 40. so it's pretty strong you know +compared to some of the weaker things + + align:start position:0% +compared to some of the weaker things + + + align:start position:0% +compared to some of the weaker things +like london + + align:start position:0% +like london + + + align:start position:0% +like london +the hydrogen bond can be pretty strong + + align:start position:0% +the hydrogen bond can be pretty strong + + + align:start position:0% +the hydrogen bond can be pretty strong +and one of these the examples that + + align:start position:0% +and one of these the examples that + + + align:start position:0% +and one of these the examples that +is the classic example would be + + align:start position:0% +is the classic example would be + + + align:start position:0% +is the classic example would be +hydrogen hydrogen + + align:start position:0% +hydrogen hydrogen + + + align:start position:0% +hydrogen hydrogen +there's the hydrogen bond right there + + align:start position:0% +there's the hydrogen bond right there + + + align:start position:0% +there's the hydrogen bond right there +you see hydrogen bond + + align:start position:0% +you see hydrogen bond + + + align:start position:0% +you see hydrogen bond +between another oxygen with itch + + align:start position:0% +between another oxygen with itch + + + align:start position:0% +between another oxygen with itch +hydrogens + + align:start position:0% +hydrogens + + + align:start position:0% +hydrogens +as well now we talked about how water is + + align:start position:0% +as well now we talked about how water is + + + align:start position:0% +as well now we talked about how water is +so special + + align:start position:0% +so special + + + align:start position:0% +so special +because in the case of water not only + + align:start position:0% +because in the case of water not only + + + align:start position:0% +because in the case of water not only +do i have exactly two hydrogens in each + + align:start position:0% +do i have exactly two hydrogens in each + + + align:start position:0% +do i have exactly two hydrogens in each +molecule that i've + + align:start position:0% +molecule that i've + + + align:start position:0% +molecule that i've +caused this strong delta plus but i've + + align:start position:0% +caused this strong delta plus but i've + + + align:start position:0% +caused this strong delta plus but i've +also got two lone pairs + + align:start position:0% +also got two lone pairs + + + align:start position:0% +also got two lone pairs +so the numbers work right in hf that's + + align:start position:0% +so the numbers work right in hf that's + + + align:start position:0% +so the numbers work right in hf that's +also a hydrogen bonded + + align:start position:0% +also a hydrogen bonded + + + align:start position:0% +also a hydrogen bonded +it can hydrogen bond to itself right but + + align:start position:0% +it can hydrogen bond to itself right but + + + align:start position:0% +it can hydrogen bond to itself right but +i've got three lone pairs on each f and + + align:start position:0% +i've got three lone pairs on each f and + + + align:start position:0% +i've got three lone pairs on each f and +only one hydrogen that i've taken that + + align:start position:0% +only one hydrogen that i've taken that + + + align:start position:0% +only one hydrogen that i've taken that +charge away from so you still get the + + align:start position:0% +charge away from so you still get the + + + align:start position:0% +charge away from so you still get the +hydrogen bonding but this is the + + align:start position:0% +hydrogen bonding but this is the + + + align:start position:0% +hydrogen bonding but this is the +beautiful balance + + align:start position:0% +beautiful balance + + + align:start position:0% +beautiful balance +oh and there's a video showing water + + align:start position:0% +oh and there's a video showing water + + + align:start position:0% +oh and there's a video showing water +bonded to each other there it is oh + + align:start position:0% +bonded to each other there it is oh + + + align:start position:0% +bonded to each other there it is oh +because there's nothing like just + + align:start position:0% +because there's nothing like just + + + align:start position:0% +because there's nothing like just +imagining what a hydrogen bond looks + + align:start position:0% +imagining what a hydrogen bond looks + + + align:start position:0% +imagining what a hydrogen bond looks +like + + align:start position:0% +like + + + align:start position:0% +like +and so of course a hydrogen bond well + + align:start position:0% +and so of course a hydrogen bond well + + + align:start position:0% +and so of course a hydrogen bond well +okay charges oh it's french pole + + align:start position:0% +okay charges oh it's french pole + + + align:start position:0% +okay charges oh it's french pole +right okay oh that's what it looks like + + align:start position:0% +right okay oh that's what it looks like + + + align:start position:0% +right okay oh that's what it looks like +it really if you could get down there it + + align:start position:0% +it really if you could get down there it + + + align:start position:0% +it really if you could get down there it +would be a ray of a laser beam + + align:start position:0% +would be a ray of a laser beam + + + align:start position:0% +would be a ray of a laser beam +light it says + + align:start position:0% +light it says + + + align:start position:0% +light it says +hydrogen and that's + + align:start position:0% +hydrogen and that's + + + align:start position:0% +hydrogen and that's +and and there it is and this is what's + + align:start position:0% +and and there it is and this is what's + + + align:start position:0% +and and there it is and this is what's +going on in the liquid right and they're + + align:start position:0% +going on in the liquid right and they're + + + align:start position:0% +going on in the liquid right and they're +kind of seeing each other + + align:start position:0% +kind of seeing each other + + + align:start position:0% +kind of seeing each other +and they're talking in there but they + + align:start position:0% +and they're talking in there but they + + + align:start position:0% +and they're talking in there but they +feel this strong + + align:start position:0% +feel this strong + + + align:start position:0% +feel this strong +strong hydrogen bond okay and that's + + align:start position:0% +strong hydrogen bond okay and that's + + + align:start position:0% +strong hydrogen bond okay and that's +happening all over the place and in a + + align:start position:0% +happening all over the place and in a + + + align:start position:0% +happening all over the place and in a +liquid + + align:start position:0% +liquid + + + align:start position:0% +liquid +they are making and breaking all the + + align:start position:0% +they are making and breaking all the + + + align:start position:0% +they are making and breaking all the +time + + align:start position:0% +time + + + align:start position:0% +time +question + + align:start position:0% + + + + align:start position:0% + +yeah yeah because well it depends right + + align:start position:0% +yeah yeah because well it depends right + + + align:start position:0% +yeah yeah because well it depends right +it depends it's a great question + + align:start position:0% +it depends it's a great question + + + align:start position:0% +it depends it's a great question +why do they separate right well they + + align:start position:0% +why do they separate right well they + + + align:start position:0% +why do they separate right well they +don't in + + align:start position:0% +don't in + + + align:start position:0% +don't in +ice right so in ice i mean you know they + + align:start position:0% +ice right so in ice i mean you know they + + + align:start position:0% +ice right so in ice i mean you know they +can + + align:start position:0% +can + + + align:start position:0% +can +but a nice it's a solid so they're sort + + align:start position:0% +but a nice it's a solid so they're sort + + + align:start position:0% +but a nice it's a solid so they're sort +of locked in + + align:start position:0% +of locked in + + + align:start position:0% +of locked in +right and and so in there you're gonna + + align:start position:0% +right and and so in there you're gonna + + + align:start position:0% +right and and so in there you're gonna +have pretty much each water molecule has + + align:start position:0% +have pretty much each water molecule has + + + align:start position:0% +have pretty much each water molecule has +four look at this it's you know from + + align:start position:0% +four look at this it's you know from + + + align:start position:0% +four look at this it's you know from +vesper right + + align:start position:0% +vesper right + + + align:start position:0% +vesper right +four possible four possible bonds you + + align:start position:0% +four possible four possible bonds you + + + align:start position:0% +four possible four possible bonds you +can make + + align:start position:0% +can make + + + align:start position:0% +can make +tetrahedral would sort of but there's + + align:start position:0% +tetrahedral would sort of but there's + + + align:start position:0% +tetrahedral would sort of but there's +actually lots of ways you can orient + + align:start position:0% +actually lots of ways you can orient + + + align:start position:0% +actually lots of ways you can orient +them in a solid so there's many forms of + + align:start position:0% +them in a solid so there's many forms of + + + align:start position:0% +them in a solid so there's many forms of +ice 12 + + align:start position:0% +ice 12 + + + align:start position:0% +ice 12 +different ways to make a solid of ice + + align:start position:0% +different ways to make a solid of ice + + + align:start position:0% +different ways to make a solid of ice +right but but see + + align:start position:0% +right but but see + + + align:start position:0% +right but but see +here goes in tight + + align:start position:0% +here goes in tight + + + align:start position:0% +here goes in tight +so so here in the liquid at room + + align:start position:0% +so so here in the liquid at room + + + align:start position:0% +so so here in the liquid at room +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +with the laser beams they're coming in + + align:start position:0% +with the laser beams they're coming in + + + align:start position:0% +with the laser beams they're coming in +and + + align:start position:0% +and + + + align:start position:0% +and +and they're bonding but they have enough + + align:start position:0% +and they're bonding but they have enough + + + align:start position:0% +and they're bonding but they have enough +energy to break the bond too + + align:start position:0% +energy to break the bond too + + + align:start position:0% +energy to break the bond too +so they stick and they unstick because + + align:start position:0% +so they stick and they unstick because + + + align:start position:0% +so they stick and they unstick because +there's enough thermal energy in the + + align:start position:0% +there's enough thermal energy in the + + + align:start position:0% +there's enough thermal energy in the +system + + align:start position:0% +system + + + align:start position:0% +system +to continuously break them and remake + + align:start position:0% +to continuously break them and remake + + + align:start position:0% +to continuously break them and remake +them that's what that's when it's a + + align:start position:0% +them that's what that's when it's a + + + align:start position:0% +them that's what that's when it's a +liquid + + align:start position:0% +liquid + + + align:start position:0% +liquid +when is it a liquid versus a gas right + + align:start position:0% +when is it a liquid versus a gas right + + + align:start position:0% +when is it a liquid versus a gas right +the boiling point remember + + align:start position:0% +the boiling point remember + + + align:start position:0% +the boiling point remember +that is a proxy we talked about last + + align:start position:0% +that is a proxy we talked about last + + + align:start position:0% +that is a proxy we talked about last +friday that is a proxy for + + align:start position:0% +friday that is a proxy for + + + align:start position:0% +friday that is a proxy for +the bonding strength between these + + align:start position:0% +the bonding strength between these + + + align:start position:0% +the bonding strength between these +molecules right + + align:start position:0% +molecules right + + + align:start position:0% +molecules right +if it's a stronger bonding then the + + align:start position:0% +if it's a stronger bonding then the + + + align:start position:0% +if it's a stronger bonding then the +boiling point will be higher and higher + + align:start position:0% +boiling point will be higher and higher + + + align:start position:0% +boiling point will be higher and higher +oh water should have boiled at a much + + align:start position:0% +oh water should have boiled at a much + + + align:start position:0% +oh water should have boiled at a much +lower temperature + + align:start position:0% +lower temperature + + + align:start position:0% +lower temperature +if it didn't have this very special + + align:start position:0% +if it didn't have this very special + + + align:start position:0% +if it didn't have this very special +hydrogen bond which is not + + align:start position:0% +hydrogen bond which is not + + + align:start position:0% +hydrogen bond which is not +a dipole dipole people try to people try + + align:start position:0% +a dipole dipole people try to people try + + + align:start position:0% +a dipole dipole people try to people try +to write the the physics of the hydrogen + + align:start position:0% +to write the the physics of the hydrogen + + + align:start position:0% +to write the the physics of the hydrogen +bond as one over r cubed that is not + + align:start position:0% +bond as one over r cubed that is not + + + align:start position:0% +bond as one over r cubed that is not +true + + align:start position:0% +true + + + align:start position:0% +true +it is not just as simple as it's another + + align:start position:0% +it is not just as simple as it's another + + + align:start position:0% +it is not just as simple as it's another +dipole-dipole-type interaction + + align:start position:0% +dipole-dipole-type interaction + + + align:start position:0% +dipole-dipole-type interaction +it's complicated complicated + + align:start position:0% + + + + align:start position:0% + +remember we had covalent bonds were + + align:start position:0% +remember we had covalent bonds were + + + align:start position:0% +remember we had covalent bonds were +complicated too + + align:start position:0% +complicated too + + + align:start position:0% +complicated too +so we're not going to put a simple one + + align:start position:0% +so we're not going to put a simple one + + + align:start position:0% +so we're not going to put a simple one +over + + align:start position:0% +over + + + align:start position:0% +over +r something dependents for the hydrogen + + align:start position:0% +r something dependents for the hydrogen + + + align:start position:0% +r something dependents for the hydrogen +bond + + align:start position:0% +bond + + + align:start position:0% +bond +okay good question okay now + + align:start position:0% +okay good question okay now + + + align:start position:0% +okay good question okay now +uh all right so that's an intermolecular + + align:start position:0% +uh all right so that's an intermolecular + + + align:start position:0% +uh all right so that's an intermolecular +now we're going to move on to + + align:start position:0% +now we're going to move on to + + + align:start position:0% +now we're going to move on to +solids that was our last intermolecular + + align:start position:0% +solids that was our last intermolecular + + + align:start position:0% +solids that was our last intermolecular +interaction oh but there's before i do + + align:start position:0% +interaction oh but there's before i do + + + align:start position:0% +interaction oh but there's before i do +there's actually + + align:start position:0% +there's actually + + + align:start position:0% +there's actually +an example question i put there that you + + align:start position:0% +an example question i put there that you + + + align:start position:0% +an example question i put there that you +could now answer + + align:start position:0% +could now answer + + + align:start position:0% +could now answer +which this is actually i just want to + + align:start position:0% +which this is actually i just want to + + + align:start position:0% +which this is actually i just want to +show you the type of okay so we cover + + align:start position:0% +show you the type of okay so we cover + + + align:start position:0% +show you the type of okay so we cover +all these intermolecular bonds + + align:start position:0% +all these intermolecular bonds + + + align:start position:0% +all these intermolecular bonds +here's a question from a quiz last year + + align:start position:0% +here's a question from a quiz last year + + + align:start position:0% +here's a question from a quiz last year +lists the intermolecular forces in each + + align:start position:0% +lists the intermolecular forces in each + + + align:start position:0% +lists the intermolecular forces in each +substance + + align:start position:0% +substance + + + align:start position:0% +substance +right methane and then you got that + + align:start position:0% +right methane and then you got that + + + align:start position:0% +right methane and then you got that +ch3oh right and then you got the ch3cl + + align:start position:0% +ch3oh right and then you got the ch3cl + + + align:start position:0% +ch3oh right and then you got the ch3cl +right and and so you can do this now + + align:start position:0% +right and and so you can do this now + + + align:start position:0% +right and and so you can do this now +because for methane + + align:start position:0% +because for methane + + + align:start position:0% +because for methane +all you got is london it's not a polar + + align:start position:0% +all you got is london it's not a polar + + + align:start position:0% +all you got is london it's not a polar +molecule all you got is london + + align:start position:0% +molecule all you got is london + + + align:start position:0% +molecule all you got is london +there's no hydrogen bonding right + + align:start position:0% +there's no hydrogen bonding right + + + align:start position:0% +there's no hydrogen bonding right +but for ch3oh + + align:start position:0% +but for ch3oh + + + align:start position:0% +but for ch3oh +do you have hydrogen bonding yeah + + align:start position:0% +do you have hydrogen bonding yeah + + + align:start position:0% +do you have hydrogen bonding yeah +you do because if you draw because you + + align:start position:0% +you do because if you draw because you + + + align:start position:0% +you do because if you draw because you +got an h that's had the + + align:start position:0% +got an h that's had the + + + align:start position:0% +got an h that's had the +the charge taken from it by oxygen a + + align:start position:0% +the charge taken from it by oxygen a + + + align:start position:0% +the charge taken from it by oxygen a +highly electronegative atom + + align:start position:0% +highly electronegative atom + + + align:start position:0% +highly electronegative atom +and then and then you've got lone pairs + + align:start position:0% +and then and then you've got lone pairs + + + align:start position:0% +and then and then you've got lone pairs +on that same oxygen so you can hydrogen + + align:start position:0% +on that same oxygen so you can hydrogen + + + align:start position:0% +on that same oxygen so you can hydrogen +bond + + align:start position:0% +bond + + + align:start position:0% +bond +and you've also got london + + align:start position:0% +and you've also got london + + + align:start position:0% +and you've also got london +right now is that it is there anything + + align:start position:0% +right now is that it is there anything + + + align:start position:0% +right now is that it is there anything +else + + align:start position:0% +else + + + align:start position:0% +else +ch3oh what else is is there any other + + align:start position:0% +ch3oh what else is is there any other + + + align:start position:0% +ch3oh what else is is there any other +type of bond + + align:start position:0% + + + + align:start position:0% + +well the last question you need to ask + + align:start position:0% +well the last question you need to ask + + + align:start position:0% +well the last question you need to ask +is is there a dipole moment + + align:start position:0% +is is there a dipole moment + + + align:start position:0% +is is there a dipole moment +in the molecule because if that molecule + + align:start position:0% +in the molecule because if that molecule + + + align:start position:0% +in the molecule because if that molecule +had a permanent dipole + + align:start position:0% +had a permanent dipole + + + align:start position:0% +had a permanent dipole +then there's another type of + + align:start position:0% +then there's another type of + + + align:start position:0% +then there's another type of +intermolecular interaction like we + + align:start position:0% +intermolecular interaction like we + + + align:start position:0% +intermolecular interaction like we +talked about + + align:start position:0% +talked about + + + align:start position:0% +talked about +dipole-dipole so you'd have three right + + align:start position:0% +dipole-dipole so you'd have three right + + + align:start position:0% +dipole-dipole so you'd have three right +and for ch3cl well there + + align:start position:0% +and for ch3cl well there + + + align:start position:0% +and for ch3cl well there +you you also you know that for ch3cl + + align:start position:0% +you you also you know that for ch3cl + + + align:start position:0% +you you also you know that for ch3cl +you're going to have a dipole moment + + align:start position:0% +you're going to have a dipole moment + + + align:start position:0% +you're going to have a dipole moment +remember we compare dipole moments and + + align:start position:0% +remember we compare dipole moments and + + + align:start position:0% +remember we compare dipole moments and +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +and if you have a dipole moment in a + + align:start position:0% +and if you have a dipole moment in a + + + align:start position:0% +and if you have a dipole moment in a +molecule then that dipole moment can + + align:start position:0% +molecule then that dipole moment can + + + align:start position:0% +molecule then that dipole moment can +talk to another + + align:start position:0% +talk to another + + + align:start position:0% +talk to another +dipole moment and be interacting with it + + align:start position:0% +dipole moment and be interacting with it + + + align:start position:0% +dipole moment and be interacting with it +so that's a kind of bond + + align:start position:0% +so that's a kind of bond + + + align:start position:0% +so that's a kind of bond +and is that it + + align:start position:0% + + + + align:start position:0% + +london london is always there + + align:start position:0% +london london is always there + + + align:start position:0% +london london is always there +it's always there you've also got london + + align:start position:0% +it's always there you've also got london + + + align:start position:0% +it's always there you've also got london +don't forget + + align:start position:0% +don't forget + + + align:start position:0% +don't forget +right so you'd have dipole dipole plus + + align:start position:0% +right so you'd have dipole dipole plus + + + align:start position:0% +right so you'd have dipole dipole plus +london here + + align:start position:0% +london here + + + align:start position:0% +london here +right dipole dipole london and hydrogen + + align:start position:0% +right dipole dipole london and hydrogen + + + align:start position:0% +right dipole dipole london and hydrogen +just london right so this is what this + + align:start position:0% +just london right so this is what this + + + align:start position:0% +just london right so this is what this +is the kind of way i want + + align:start position:0% +is the kind of way i want + + + align:start position:0% +is the kind of way i want +and you might be able to think about + + align:start position:0% +and you might be able to think about + + + align:start position:0% +and you might be able to think about +well what would a trend like you know + + align:start position:0% +well what would a trend like you know + + + align:start position:0% +well what would a trend like you know +if you think about like okay well if a + + align:start position:0% +if you think about like okay well if a + + + align:start position:0% +if you think about like okay well if a +molecule just has london + + align:start position:0% +molecule just has london + + + align:start position:0% +molecule just has london +then what does london depend on + + align:start position:0% +then what does london depend on + + + align:start position:0% +then what does london depend on +right well it depends on the + + align:start position:0% +right well it depends on the + + + align:start position:0% +right well it depends on the +polarizability + + align:start position:0% +polarizability + + + align:start position:0% +polarizability +of the charge so that could be something + + align:start position:0% +of the charge so that could be something + + + align:start position:0% +of the charge so that could be something +with acid it depends on the size because + + align:start position:0% +with acid it depends on the size because + + + align:start position:0% +with acid it depends on the size because +that + + align:start position:0% +that + + + align:start position:0% +that +tells you how much i say well what about + + align:start position:0% +tells you how much i say well what about + + + align:start position:0% +tells you how much i say well what about +sih4 compared to ch4 + + align:start position:0% +sih4 compared to ch4 + + + align:start position:0% +sih4 compared to ch4 +sih which is going to be you know more + + align:start position:0% +sih which is going to be you know more + + + align:start position:0% +sih which is going to be you know more +strongly bonded + + align:start position:0% +strongly bonded + + + align:start position:0% +strongly bonded +right you can answer that because you + + align:start position:0% +right you can answer that because you + + + align:start position:0% +right you can answer that because you +know the only force there is london + + align:start position:0% +know the only force there is london + + + align:start position:0% +know the only force there is london +and you know for london it's how much + + align:start position:0% +and you know for london it's how much + + + align:start position:0% +and you know for london it's how much +contact area you have is going to be one + + align:start position:0% +contact area you have is going to be one + + + align:start position:0% +contact area you have is going to be one +of the factors the more contact + + align:start position:0% +of the factors the more contact + + + align:start position:0% +of the factors the more contact +the more chances these things can get + + align:start position:0% +the more chances these things can get + + + align:start position:0% +the more chances these things can get +close enough and polarized + + align:start position:0% +close enough and polarized + + + align:start position:0% +close enough and polarized +right and then polarizability would be + + align:start position:0% +right and then polarizability would be + + + align:start position:0% +right and then polarizability would be +the other + + align:start position:0% +the other + + + align:start position:0% +the other +good okay all right now we're going on + + align:start position:0% +good okay all right now we're going on + + + align:start position:0% +good okay all right now we're going on +to solids + + align:start position:0% +to solids + + + align:start position:0% +to solids +now the big picture is + + align:start position:0% +now the big picture is + + + align:start position:0% +now the big picture is +pretty awesome if you look at the big + + align:start position:0% +pretty awesome if you look at the big + + + align:start position:0% +pretty awesome if you look at the big +picture + + align:start position:0% +picture + + + align:start position:0% +picture +we have done the electronic structure of + + align:start position:0% +we have done the electronic structure of + + + align:start position:0% +we have done the electronic structure of +atoms and + + align:start position:0% +atoms and + + + align:start position:0% +atoms and +molecules right so we've gone through + + align:start position:0% +molecules right so we've gone through + + + align:start position:0% +molecules right so we've gone through +and we worked our way through the bore + + align:start position:0% +and we worked our way through the bore + + + align:start position:0% +and we worked our way through the bore +atom the atomic model + + align:start position:0% +atom the atomic model + + + align:start position:0% +atom the atomic model +quantum numbers aufbau what happens when + + align:start position:0% +quantum numbers aufbau what happens when + + + align:start position:0% +quantum numbers aufbau what happens when +you go from one electron to many + + align:start position:0% +you go from one electron to many + + + align:start position:0% +you go from one electron to many +and octet stability which is lewis and + + align:start position:0% +and octet stability which is lewis and + + + align:start position:0% +and octet stability which is lewis and +vesper + + align:start position:0% +vesper + + + align:start position:0% +vesper +we have also now talked about how + + align:start position:0% +we have also now talked about how + + + align:start position:0% +we have also now talked about how +molecules come together in different + + align:start position:0% +molecules come together in different + + + align:start position:0% +molecules come together in different +ways how the atoms come together in the + + align:start position:0% +ways how the atoms come together in the + + + align:start position:0% +ways how the atoms come together in the +molecule + + align:start position:0% +molecule + + + align:start position:0% +molecule +and how the molecules come together in + + align:start position:0% +and how the molecules come together in + + + align:start position:0% +and how the molecules come together in +different ways right dipole dipole + + align:start position:0% +different ways right dipole dipole + + + align:start position:0% +different ways right dipole dipole +london dispersion hydrogen bonding right + + align:start position:0% +london dispersion hydrogen bonding right + + + align:start position:0% +london dispersion hydrogen bonding right +and then there's these forms of + + align:start position:0% +and then there's these forms of + + + align:start position:0% +and then there's these forms of +aggregation gas liquid and solid and of + + align:start position:0% +aggregation gas liquid and solid and of + + + align:start position:0% +aggregation gas liquid and solid and of +course we're excited about this + + align:start position:0% +course we're excited about this + + + align:start position:0% +course we're excited about this +so i put my little emoji there + + align:start position:0% +so i put my little emoji there + + + align:start position:0% +so i put my little emoji there +right because that's what we're gonna do + + align:start position:0% +right because that's what we're gonna do + + + align:start position:0% +right because that's what we're gonna do +now we're actually gonna + + align:start position:0% +now we're actually gonna + + + align:start position:0% +now we're actually gonna +take we talked a little bit about solids + + align:start position:0% +take we talked a little bit about solids + + + align:start position:0% +take we talked a little bit about solids +already but now we're to take + + align:start position:0% +already but now we're to take + + + align:start position:0% +already but now we're to take +the electronic structure that we've + + align:start position:0% +the electronic structure that we've + + + align:start position:0% +the electronic structure that we've +built up + + align:start position:0% +built up + + + align:start position:0% +built up +right these orbitals and we're going to + + align:start position:0% +right these orbitals and we're going to + + + align:start position:0% +right these orbitals and we're going to +make solids out of them + + align:start position:0% +make solids out of them + + + align:start position:0% +make solids out of them +okay so this is the week where + + align:start position:0% +okay so this is the week where + + + align:start position:0% +okay so this is the week where +these are the next two weeks right where + + align:start position:0% +these are the next two weeks right where + + + align:start position:0% +these are the next two weeks right where +we're going to talk a lot about + + align:start position:0% +we're going to talk a lot about + + + align:start position:0% +we're going to talk a lot about +solids and this week + + align:start position:0% +solids and this week + + + align:start position:0% +solids and this week +this week okay this week + + align:start position:0% +this week okay this week + + + align:start position:0% +this week okay this week +we're going to do the electronic + + align:start position:0% +we're going to do the electronic + + + align:start position:0% +we're going to do the electronic +structure + + align:start position:0% +structure + + + align:start position:0% +structure +and next week + + align:start position:0% + + + + align:start position:0% + +we're going to do adams so that's our + + align:start position:0% +we're going to do adams so that's our + + + align:start position:0% +we're going to do adams so that's our +plan + + align:start position:0% +plan + + + align:start position:0% +plan +right and next week friday we're going + + align:start position:0% +right and next week friday we're going + + + align:start position:0% +right and next week friday we're going +to break a bunch of stuff with parents + + align:start position:0% +to break a bunch of stuff with parents + + + align:start position:0% +to break a bunch of stuff with parents +so so this week we're going to what do + + align:start position:0% +so so this week we're going to what do + + + align:start position:0% +so so this week we're going to what do +electrons do in solids + + align:start position:0% +electrons do in solids + + + align:start position:0% +electrons do in solids +next week how do atoms arrange in solids + + align:start position:0% +next week how do atoms arrange in solids + + + align:start position:0% +next week how do atoms arrange in solids +and together that gives us so much + + align:start position:0% +and together that gives us so much + + + align:start position:0% +and together that gives us so much +understanding + + align:start position:0% +understanding + + + align:start position:0% +understanding +of how chemistry affects properties in + + align:start position:0% +of how chemistry affects properties in + + + align:start position:0% +of how chemistry affects properties in +solids + + align:start position:0% +solids + + + align:start position:0% +solids +okay so that's the big picture now + + align:start position:0% +okay so that's the big picture now + + + align:start position:0% +okay so that's the big picture now +here's the thing + + align:start position:0% +here's the thing + + + align:start position:0% +here's the thing +why does that matter well because so + + align:start position:0% +why does that matter well because so + + + align:start position:0% +why does that matter well because so +many properties can vary by + + align:start position:0% +many properties can vary by + + + align:start position:0% +many properties can vary by +so much depending on what i just said + + align:start position:0% +so much depending on what i just said + + + align:start position:0% +so much depending on what i just said +how does chemistry affect properties in + + align:start position:0% +how does chemistry affect properties in + + + align:start position:0% +how does chemistry affect properties in +solids well + + align:start position:0% +solids well + + + align:start position:0% +solids well +it's it's complicated but look at this + + align:start position:0% +it's it's complicated but look at this + + + align:start position:0% +it's it's complicated but look at this +variation + + align:start position:0% +variation + + + align:start position:0% +variation +28 orders of magnitude of conductivity + + align:start position:0% +28 orders of magnitude of conductivity + + + align:start position:0% +28 orders of magnitude of conductivity +electrical conductivity + + align:start position:0% +electrical conductivity + + + align:start position:0% +electrical conductivity +28 orders of magnitude that's a lot of + + align:start position:0% +28 orders of magnitude that's a lot of + + + align:start position:0% +28 orders of magnitude that's a lot of +zeros + + align:start position:0% +zeros + + + align:start position:0% +zeros +10 minus these are the electrical + + align:start position:0% +10 minus these are the electrical + + + align:start position:0% +10 minus these are the electrical +conductivities of different + + align:start position:0% +conductivities of different + + + align:start position:0% +conductivities of different +atoms right different uh + + align:start position:0% +atoms right different uh + + + align:start position:0% +atoms right different uh +materials and you can see that + + align:start position:0% +materials and you can see that + + + align:start position:0% +materials and you can see that +it's going to depend on what you have + + align:start position:0% +it's going to depend on what you have + + + align:start position:0% +it's going to depend on what you have +but it's also going to depend + + align:start position:0% +but it's also going to depend + + + align:start position:0% +but it's also going to depend +on so that's the chemistry but it's also + + align:start position:0% +on so that's the chemistry but it's also + + + align:start position:0% +on so that's the chemistry but it's also +going to depend on the bonding + + align:start position:0% +going to depend on the bonding + + + align:start position:0% +going to depend on the bonding +it's going to depend on how the + + align:start position:0% +it's going to depend on how the + + + align:start position:0% +it's going to depend on how the +electronic structure comes together + + align:start position:0% +electronic structure comes together + + + align:start position:0% +electronic structure comes together +and it's going to depend on how the + + align:start position:0% +and it's going to depend on how the + + + align:start position:0% +and it's going to depend on how the +atoms come together that is what will + + align:start position:0% +atoms come together that is what will + + + align:start position:0% +atoms come together that is what will +explain + + align:start position:0% +explain + + + align:start position:0% +explain +28 orders of magnitude that has a lot of + + align:start position:0% +28 orders of magnitude that has a lot of + + + align:start position:0% +28 orders of magnitude that has a lot of +variation + + align:start position:0% +variation + + + align:start position:0% +variation +right so we're going to start by + + align:start position:0% +right so we're going to start by + + + align:start position:0% +right so we're going to start by +thinking about how electrons + + align:start position:0% +thinking about how electrons + + + align:start position:0% +thinking about how electrons +see these solids that's how we're going + + align:start position:0% +see these solids that's how we're going + + + align:start position:0% +see these solids that's how we're going +to start + + align:start position:0% +to start + + + align:start position:0% +to start +now the thing is that these good old + + align:start position:0% +now the thing is that these good old + + + align:start position:0% +now the thing is that these good old +days these good old days + + align:start position:0% +days these good old days + + + align:start position:0% +days these good old days +of molecular orbital theory are going to + + align:start position:0% +of molecular orbital theory are going to + + + align:start position:0% +of molecular orbital theory are going to +end + + align:start position:0% +end + + + align:start position:0% +end +they're gonna have to end today no + + align:start position:0% +they're gonna have to end today no + + + align:start position:0% +they're gonna have to end today no +they're not ending for like quizzes + + align:start position:0% +they're not ending for like quizzes + + + align:start position:0% +they're not ending for like quizzes +and exams don't forget about them but + + align:start position:0% +and exams don't forget about them but + + + align:start position:0% +and exams don't forget about them but +we gotta move on because this is just + + align:start position:0% +we gotta move on because this is just + + + align:start position:0% +we gotta move on because this is just +two atoms + + align:start position:0% +two atoms + + + align:start position:0% +two atoms +two atoms but what happens when we have + + align:start position:0% +two atoms but what happens when we have + + + align:start position:0% +two atoms but what happens when we have +like a solid right how many atoms do we + + align:start position:0% +like a solid right how many atoms do we + + + align:start position:0% +like a solid right how many atoms do we +have + + align:start position:0% +have + + + align:start position:0% +have +we got a lot we got a lot so let's go + + align:start position:0% +we got a lot we got a lot so let's go + + + align:start position:0% +we got a lot we got a lot so let's go +i'll go here okay now you know + + align:start position:0% +i'll go here okay now you know + + + align:start position:0% +i'll go here okay now you know +if you look if you think about that + + align:start position:0% +if you look if you think about that + + + align:start position:0% +if you look if you think about that +picture that was our p + + align:start position:0% +picture that was our p + + + align:start position:0% +picture that was our p +i'm going to take 1s orbitals + + align:start position:0% +i'm going to take 1s orbitals + + + align:start position:0% +i'm going to take 1s orbitals +and let's just think about this for a + + align:start position:0% +and let's just think about this for a + + + align:start position:0% +and let's just think about this for a +second + + align:start position:0% +second + + + align:start position:0% +second +if you take 1s orbitals and you make and + + align:start position:0% +if you take 1s orbitals and you make and + + + align:start position:0% +if you take 1s orbitals and you make and +you have 2 atoms + + align:start position:0% +you have 2 atoms + + + align:start position:0% +you have 2 atoms +that come together well they're gonna + + align:start position:0% +that come together well they're gonna + + + align:start position:0% +that come together well they're gonna +you know do just what you see there + + align:start position:0% +you know do just what you see there + + + align:start position:0% +you know do just what you see there +where you've got your 1s and your 1s + + align:start position:0% +where you've got your 1s and your 1s + + + align:start position:0% +where you've got your 1s and your 1s +and i'm even going to fill these up in + + align:start position:0% +and i'm even going to fill these up in + + + align:start position:0% +and i'm even going to fill these up in +the sigma and sigma star + + align:start position:0% +the sigma and sigma star + + + align:start position:0% +the sigma and sigma star +so that would be like two 1s orbitals + + align:start position:0% +so that would be like two 1s orbitals + + + align:start position:0% +so that would be like two 1s orbitals +that i have either okay so up here i + + align:start position:0% +that i have either okay so up here i + + + align:start position:0% +that i have either okay so up here i +took + + align:start position:0% +took + + + align:start position:0% +took +one it was a positive and i subtracted + + align:start position:0% +one it was a positive and i subtracted + + + align:start position:0% +one it was a positive and i subtracted +one + + align:start position:0% +one + + + align:start position:0% +one +and here i took one and i added one + + align:start position:0% +and here i took one and i added one + + + align:start position:0% +and here i took one and i added one +and remember this gave us this + + align:start position:0% +and remember this gave us this + + + align:start position:0% +and remember this gave us this +and this and this gave us the bonding + + align:start position:0% +and this and this gave us the bonding + + + align:start position:0% +and this and this gave us the bonding +orbital right + + align:start position:0% +orbital right + + + align:start position:0% +orbital right +bonding antibonding it all came from + + align:start position:0% +bonding antibonding it all came from + + + align:start position:0% +bonding antibonding it all came from +lcao + + align:start position:0% +lcao + + + align:start position:0% +lcao +lcao is a linear combination of atomic + + align:start position:0% +lcao is a linear combination of atomic + + + align:start position:0% +lcao is a linear combination of atomic +orbitals that's the theory we use to + + align:start position:0% +orbitals that's the theory we use to + + + align:start position:0% +orbitals that's the theory we use to +build up our mo theory + + align:start position:0% +build up our mo theory + + + align:start position:0% +build up our mo theory +right but now we got to go a lot further + + align:start position:0% +right but now we got to go a lot further + + + align:start position:0% +right but now we got to go a lot further +right + + align:start position:0% +right + + + align:start position:0% +right +so i'm going to because i don't want to + + align:start position:0% +so i'm going to because i don't want to + + + align:start position:0% +so i'm going to because i don't want to +keep adding things + + align:start position:0% +keep adding things + + + align:start position:0% +keep adding things +here and here it gets complicated right + + align:start position:0% +here and here it gets complicated right + + + align:start position:0% +here and here it gets complicated right +i'm trying to find + + align:start position:0% +i'm trying to find + + + align:start position:0% +i'm trying to find +the the mos for more and more and more + + align:start position:0% +the the mos for more and more and more + + + align:start position:0% +the the mos for more and more and more +atoms + + align:start position:0% +atoms + + + align:start position:0% +atoms +because i got to put a whole lot into my + + align:start position:0% +because i got to put a whole lot into my + + + align:start position:0% +because i got to put a whole lot into my +solid right + + align:start position:0% +solid right + + + align:start position:0% +solid right +so i'm going to write them on the just + + align:start position:0% +so i'm going to write them on the just + + + align:start position:0% +so i'm going to write them on the just +on one side right if i write + + align:start position:0% +on one side right if i write + + + align:start position:0% +on one side right if i write +the two here like that + + align:start position:0% +the two here like that + + + align:start position:0% +the two here like that +and that would be sigma and sigma star + + align:start position:0% +and that would be sigma and sigma star + + + align:start position:0% +and that would be sigma and sigma star +then you know what i'm talking about i'm + + align:start position:0% +then you know what i'm talking about i'm + + + align:start position:0% +then you know what i'm talking about i'm +taking the two and i'm combining them in + + align:start position:0% +taking the two and i'm combining them in + + + align:start position:0% +taking the two and i'm combining them in +two different ways + + align:start position:0% +two different ways + + + align:start position:0% +two different ways +but what if i had three well see if i + + align:start position:0% +but what if i had three well see if i + + + align:start position:0% +but what if i had three well see if i +had + + align:start position:0% +had + + + align:start position:0% +had +three so i've got three s orbitals now + + align:start position:0% +three so i've got three s orbitals now + + + align:start position:0% +three so i've got three s orbitals now +right so if i've got three s orbitals + + align:start position:0% +right so if i've got three s orbitals + + + align:start position:0% +right so if i've got three s orbitals +then + + align:start position:0% +then + + + align:start position:0% +then +if you think about it i could also add + + align:start position:0% +if you think about it i could also add + + + align:start position:0% +if you think about it i could also add +them + + align:start position:0% +them + + + align:start position:0% +them +like that that would be a very nice + + align:start position:0% +like that that would be a very nice + + + align:start position:0% +like that that would be a very nice +bonding orbital right if you add them + + align:start position:0% +bonding orbital right if you add them + + + align:start position:0% +bonding orbital right if you add them +you see that they're + + align:start position:0% +you see that they're + + + align:start position:0% +you see that they're +they're going to have the same kind of + + align:start position:0% +they're going to have the same kind of + + + align:start position:0% +they're going to have the same kind of +really nice body but i could also + + align:start position:0% +really nice body but i could also + + + align:start position:0% +really nice body but i could also +subtract one in the middle + + align:start position:0% +subtract one in the middle + + + align:start position:0% +subtract one in the middle +and if i did that so i had a plus + + align:start position:0% +and if i did that so i had a plus + + + align:start position:0% +and if i did that so i had a plus +minus plus there right so those are the + + align:start position:0% +minus plus there right so those are the + + + align:start position:0% +minus plus there right so those are the +signs right + + align:start position:0% +signs right + + + align:start position:0% +signs right +plus s minus s plus s then + + align:start position:0% +plus s minus s plus s then + + + align:start position:0% +plus s minus s plus s then +you can see that in between those as i + + align:start position:0% +you can see that in between those as i + + + align:start position:0% +you can see that in between those as i +add these together you have nodes + + align:start position:0% +add these together you have nodes + + + align:start position:0% +add these together you have nodes +right so like this is not going to look + + align:start position:0% +right so like this is not going to look + + + align:start position:0% +right so like this is not going to look +very like a very happy bonding situation + + align:start position:0% +very like a very happy bonding situation + + + align:start position:0% +very like a very happy bonding situation +i'm going to have something in there + + align:start position:0% +i'm going to have something in there + + + align:start position:0% +i'm going to have something in there +and then something in there that's what + + align:start position:0% +and then something in there that's what + + + align:start position:0% +and then something in there that's what +that's going to look like as i bring + + align:start position:0% +that's going to look like as i bring + + + align:start position:0% +that's going to look like as i bring +them closer and try to add them + + align:start position:0% +them closer and try to add them + + + align:start position:0% +them closer and try to add them +i made two nodes here well there's one + + align:start position:0% +i made two nodes here well there's one + + + align:start position:0% +i made two nodes here well there's one +other way you could do this and we know + + align:start position:0% +other way you could do this and we know + + + align:start position:0% +other way you could do this and we know +that the number of molecular orbitals + + align:start position:0% +that the number of molecular orbitals + + + align:start position:0% +that the number of molecular orbitals +has to equal + + align:start position:0% +has to equal + + + align:start position:0% +has to equal +the number of atomic orbitals right we + + align:start position:0% +the number of atomic orbitals right we + + + align:start position:0% +the number of atomic orbitals right we +know that so + + align:start position:0% +know that so + + + align:start position:0% +know that so +there's one more that we need because i + + align:start position:0% +there's one more that we need because i + + + align:start position:0% +there's one more that we need because i +started with three s's + + align:start position:0% +started with three s's + + + align:start position:0% +started with three s's +and you can kind of see that right you + + align:start position:0% +and you can kind of see that right you + + + align:start position:0% +and you can kind of see that right you +can see that because if i had + + align:start position:0% +can see that because if i had + + + align:start position:0% +can see that because if i had +a plus and a plus + + align:start position:0% +a plus and a plus + + + align:start position:0% +a plus and a plus +if i had done it that way or maybe the + + align:start position:0% +if i had done it that way or maybe the + + + align:start position:0% +if i had done it that way or maybe the +other way right maybe this was + + align:start position:0% +other way right maybe this was + + + align:start position:0% +other way right maybe this was +over there but you see i got a i got a + + align:start position:0% +over there but you see i got a i got a + + + align:start position:0% +over there but you see i got a i got a +little bonding going on in here between + + align:start position:0% +little bonding going on in here between + + + align:start position:0% +little bonding going on in here between +them and i got an anti-bonding there + + align:start position:0% +them and i got an anti-bonding there + + + align:start position:0% +them and i got an anti-bonding there +it's almost like it kind of cancels out + + align:start position:0% +it's almost like it kind of cancels out + + + align:start position:0% +it's almost like it kind of cancels out +so you could imagine that that + + align:start position:0% +so you could imagine that that + + + align:start position:0% +so you could imagine that that +combination of s orbitals if i add and + + align:start position:0% +combination of s orbitals if i add and + + + align:start position:0% +combination of s orbitals if i add and +subtract them this way it's going to be + + align:start position:0% +subtract them this way it's going to be + + + align:start position:0% +subtract them this way it's going to be +somewhere right in the middle + + align:start position:0% +somewhere right in the middle + + + align:start position:0% +somewhere right in the middle +right maybe not so bonding maybe not so + + align:start position:0% +right maybe not so bonding maybe not so + + + align:start position:0% +right maybe not so bonding maybe not so +antibody + + align:start position:0% +antibody + + + align:start position:0% +antibody +okay good all right well let's do four + + align:start position:0% +okay good all right well let's do four + + + align:start position:0% +okay good all right well let's do four +so if i had four if i started with four + + align:start position:0% +so if i had four if i started with four + + + align:start position:0% +so if i had four if i started with four +this is like four hydrogen atoms let's + + align:start position:0% +this is like four hydrogen atoms let's + + + align:start position:0% +this is like four hydrogen atoms let's +say although i'm not filling it yet + + align:start position:0% +say although i'm not filling it yet + + + align:start position:0% +say although i'm not filling it yet +but so four 1s orbitals well now + + align:start position:0% +but so four 1s orbitals well now + + + align:start position:0% +but so four 1s orbitals well now +you see i could do this i can add them + + align:start position:0% +you see i could do this i can add them + + + align:start position:0% +you see i could do this i can add them +all up + + align:start position:0% +all up + + + align:start position:0% +all up +and get this super awesome bonding state + + align:start position:0% + + + + align:start position:0% + +well i could also alternate them + + align:start position:0% +well i could also alternate them + + + align:start position:0% +well i could also alternate them +so that everything is anti-bonding + + align:start position:0% +so that everything is anti-bonding + + + align:start position:0% +so that everything is anti-bonding +look at that right these are going to + + align:start position:0% +look at that right these are going to + + + align:start position:0% +look at that right these are going to +cancel as you bring them together + + align:start position:0% +cancel as you bring them together + + + align:start position:0% +cancel as you bring them together +and you're going to get antibonding + + align:start position:0% +and you're going to get antibonding + + + align:start position:0% +and you're going to get antibonding +antibonding right + + align:start position:0% +antibonding right + + + align:start position:0% +antibonding right +but there's also two other options + + align:start position:0% +but there's also two other options + + + align:start position:0% +but there's also two other options +because in tight + + align:start position:0% +because in tight + + + align:start position:0% +because in tight +that are in between right here i can add + + align:start position:0% +that are in between right here i can add + + + align:start position:0% +that are in between right here i can add +two and then subtract two and you can + + align:start position:0% +two and then subtract two and you can + + + align:start position:0% +two and then subtract two and you can +see + + align:start position:0% +see + + + align:start position:0% +see +these would these are both negative and + + align:start position:0% +these would these are both negative and + + + align:start position:0% +these would these are both negative and +as they come together they're going to + + align:start position:0% +as they come together they're going to + + + align:start position:0% +as they come together they're going to +overlap constructively so will these but + + align:start position:0% +overlap constructively so will these but + + + align:start position:0% +overlap constructively so will these but +in the middle here + + align:start position:0% +in the middle here + + + align:start position:0% +in the middle here +they're going to be kind of destructive + + align:start position:0% +they're going to be kind of destructive + + + align:start position:0% +they're going to be kind of destructive +interference right destructive + + align:start position:0% +interference right destructive + + + align:start position:0% +interference right destructive +and so you're going to have this one + + align:start position:0% +and so you're going to have this one + + + align:start position:0% +and so you're going to have this one +node in between + + align:start position:0% +node in between + + + align:start position:0% +node in between +but in general you can imagine this will + + align:start position:0% +but in general you can imagine this will + + + align:start position:0% +but in general you can imagine this will +be more bonding + + align:start position:0% +be more bonding + + + align:start position:0% +be more bonding +than anti-bonding right so we draw it + + align:start position:0% +than anti-bonding right so we draw it + + + align:start position:0% +than anti-bonding right so we draw it +down below the middle + + align:start position:0% +down below the middle + + + align:start position:0% +down below the middle +whereas up here you could also imagine + + align:start position:0% +whereas up here you could also imagine + + + align:start position:0% +whereas up here you could also imagine +something like this + + align:start position:0% +something like this + + + align:start position:0% +something like this +where you start with a plus and you put + + align:start position:0% +where you start with a plus and you put + + + align:start position:0% +where you start with a plus and you put +two minuses in there + + align:start position:0% +two minuses in there + + + align:start position:0% +two minuses in there +and a plus over there is it just adding + + align:start position:0% +and a plus over there is it just adding + + + align:start position:0% +and a plus over there is it just adding +and subtracting it's just i'm taking lco + + align:start position:0% +and subtracting it's just i'm taking lco + + + align:start position:0% +and subtracting it's just i'm taking lco +theory + + align:start position:0% +theory + + + align:start position:0% +theory +and moving it to more than two orbitals + + align:start position:0% +and moving it to more than two orbitals + + + align:start position:0% +and moving it to more than two orbitals +okay but that that so now you see that + + align:start position:0% +okay but that that so now you see that + + + align:start position:0% +okay but that that so now you see that +you can actually understand this from + + align:start position:0% +you can actually understand this from + + + align:start position:0% +you can actually understand this from +the number of nodes right + + align:start position:0% +the number of nodes right + + + align:start position:0% +the number of nodes right +this is like three nodes + + align:start position:0% +this is like three nodes + + + align:start position:0% +this is like three nodes +this is two two nodes over there + + align:start position:0% +this is two two nodes over there + + + align:start position:0% +this is two two nodes over there +this is one node + + align:start position:0% +this is one node + + + align:start position:0% +this is one node +and zero nodes this is exactly the + + align:start position:0% +and zero nodes this is exactly the + + + align:start position:0% +and zero nodes this is exactly the +kind of thing we talked about already + + align:start position:0% +kind of thing we talked about already + + + align:start position:0% +kind of thing we talked about already +but for only two orbitals now we're just + + align:start position:0% +but for only two orbitals now we're just + + + align:start position:0% +but for only two orbitals now we're just +continuing it along + + align:start position:0% +continuing it along + + + align:start position:0% +continuing it along +okay you can see why the good old days + + align:start position:0% +okay you can see why the good old days + + + align:start position:0% +okay you can see why the good old days +are over because + + align:start position:0% +are over because + + + align:start position:0% +are over because +see now we got to jump this up a level + + align:start position:0% +see now we got to jump this up a level + + + align:start position:0% +see now we got to jump this up a level +and we got to think how many s orbitals + + align:start position:0% +and we got to think how many s orbitals + + + align:start position:0% +and we got to think how many s orbitals +do i have in a typical piece of matter + + align:start position:0% +do i have in a typical piece of matter + + + align:start position:0% +do i have in a typical piece of matter +how many do you think + + align:start position:0% + + + + align:start position:0% + +take a guess + + align:start position:0% + + + + align:start position:0% + +roughly but take a chunk of + + align:start position:0% +roughly but take a chunk of + + + align:start position:0% +roughly but take a chunk of +hydrogen this big how many how many how + + align:start position:0% +hydrogen this big how many how many how + + + align:start position:0% +hydrogen this big how many how many how +many atoms do i have + + align:start position:0% +many atoms do i have + + + align:start position:0% +many atoms do i have +a mole exactly that's why we invented + + align:start position:0% +a mole exactly that's why we invented + + + align:start position:0% +a mole exactly that's why we invented +the mole + + align:start position:0% +the mole + + + align:start position:0% +the mole +so that we could count big numbers by + + align:start position:0% +so that we could count big numbers by + + + align:start position:0% +so that we could count big numbers by +just saying one + + align:start position:0% +just saying one + + + align:start position:0% +just saying one +one mole but if i have a mole then i've + + align:start position:0% +one mole but if i have a mole then i've + + + align:start position:0% +one mole but if i have a mole then i've +got like 10 to the 24th of these + + align:start position:0% +got like 10 to the 24th of these + + + align:start position:0% +got like 10 to the 24th of these +i just went to four i just went to four + + align:start position:0% +i just went to four i just went to four + + + align:start position:0% +i just went to four i just went to four +right but it just keeps on going so + + align:start position:0% +right but it just keeps on going so + + + align:start position:0% +right but it just keeps on going so +april does this + + align:start position:0% +april does this + + + align:start position:0% +april does this +so here's like okay one okay + + align:start position:0% +so here's like okay one okay + + + align:start position:0% +so here's like okay one okay +orbital of atom oh i labeled that well + + align:start position:0% +orbital of atom oh i labeled that well + + + align:start position:0% +orbital of atom oh i labeled that well +two + + align:start position:0% +two + + + align:start position:0% +two +bonding antibonding orbitals of + + align:start position:0% +bonding antibonding orbitals of + + + align:start position:0% +bonding antibonding orbitals of +molecules and then you see okay there's + + align:start position:0% +molecules and then you see okay there's + + + align:start position:0% +molecules and then you see okay there's +three + + align:start position:0% +three + + + align:start position:0% +three +there's four five you keep on going + + align:start position:0% +there's four five you keep on going + + + align:start position:0% +there's four five you keep on going +okay they got a little tired and then + + align:start position:0% +okay they got a little tired and then + + + align:start position:0% +okay they got a little tired and then +they wrote 30 + + align:start position:0% +they wrote 30 + + + align:start position:0% +they wrote 30 +30 30 orbitals + + align:start position:0% +30 30 orbitals + + + align:start position:0% +30 30 orbitals +30 is still way way far away see but + + align:start position:0% +30 is still way way far away see but + + + align:start position:0% +30 is still way way far away see but +if you had 30 s orbitals you might still + + align:start position:0% +if you had 30 s orbitals you might still + + + align:start position:0% +if you had 30 s orbitals you might still +be able to kind of see them + + align:start position:0% +be able to kind of see them + + + align:start position:0% +be able to kind of see them +see these lines discreetly remember this + + align:start position:0% +see these lines discreetly remember this + + + align:start position:0% +see these lines discreetly remember this +is energy space they might actually + + align:start position:0% +is energy space they might actually + + + align:start position:0% +is energy space they might actually +remember like these energies are really + + align:start position:0% +remember like these energies are really + + + align:start position:0% +remember like these energies are really +important right the lines between the + + align:start position:0% +important right the lines between the + + + align:start position:0% +important right the lines between the +deltas but if you have a mole + + align:start position:0% +deltas but if you have a mole + + + align:start position:0% +deltas but if you have a mole +if you have a mole it looks like one + + align:start position:0% +if you have a mole it looks like one + + + align:start position:0% +if you have a mole it looks like one +continuous set of lines + + align:start position:0% +continuous set of lines + + + align:start position:0% +continuous set of lines +these don't really look discrete anymore + + align:start position:0% +these don't really look discrete anymore + + + align:start position:0% +these don't really look discrete anymore +right + + align:start position:0% +right + + + align:start position:0% +right +these don't look discreet and so + + align:start position:0% +these don't look discreet and so + + + align:start position:0% +these don't look discreet and so +if you have a mole of atoms so if you + + align:start position:0% +if you have a mole of atoms so if you + + + align:start position:0% +if you have a mole of atoms so if you +have a solid + + align:start position:0% +have a solid + + + align:start position:0% +have a solid +we call that that collection + + align:start position:0% +we call that that collection + + + align:start position:0% +we call that that collection +of orbitals that are all stuck in here + + align:start position:0% +of orbitals that are all stuck in here + + + align:start position:0% +of orbitals that are all stuck in here +a band we call that a band + + align:start position:0% +a band we call that a band + + + align:start position:0% +a band we call that a band +okay so if i take now i'm not going to + + align:start position:0% +okay so if i take now i'm not going to + + + align:start position:0% +okay so if i take now i'm not going to +draw + + align:start position:0% +draw + + + align:start position:0% +draw +10 to the 24th 10 to the 24th + + align:start position:0% +10 to the 24th 10 to the 24th + + + align:start position:0% +10 to the 24th 10 to the 24th +s orbitals but pretend + + align:start position:0% +s orbitals but pretend + + + align:start position:0% +s orbitals but pretend +pretend that that's what i have here + + align:start position:0% +pretend that that's what i have here + + + align:start position:0% +pretend that that's what i have here +then + + align:start position:0% +then + + + align:start position:0% +then +what happens + + align:start position:0% + + + + align:start position:0% + +what i do is i form a continuum of + + align:start position:0% +what i do is i form a continuum of + + + align:start position:0% +what i do is i form a continuum of +states + + align:start position:0% +states + + + align:start position:0% +states +a continuum of levels for those + + align:start position:0% +a continuum of levels for those + + + align:start position:0% +a continuum of levels for those +electrons and this + + align:start position:0% +electrons and this + + + align:start position:0% +electrons and this +they're so packed together we don't even + + align:start position:0% +they're so packed together we don't even + + + align:start position:0% +they're so packed together we don't even +draw them as lines we can't + + align:start position:0% +draw them as lines we can't + + + align:start position:0% +draw them as lines we can't +right so this is called the 1s + + align:start position:0% +right so this is called the 1s + + + align:start position:0% +right so this is called the 1s +band oh-ho band + + align:start position:0% +band oh-ho band + + + align:start position:0% +band oh-ho band +it's a band it's a band of states + + align:start position:0% +it's a band it's a band of states + + + align:start position:0% +it's a band it's a band of states +it's a band of states that's the 1s band + + align:start position:0% +it's a band of states that's the 1s band + + + align:start position:0% +it's a band of states that's the 1s band +now there's some important rules + + align:start position:0% +now there's some important rules + + + align:start position:0% +now there's some important rules +that are really just the same but we + + align:start position:0% +that are really just the same but we + + + align:start position:0% +that are really just the same but we +follow them here too + + align:start position:0% +follow them here too + + + align:start position:0% +follow them here too +and so i want to emphasize them we've + + align:start position:0% +and so i want to emphasize them we've + + + align:start position:0% +and so i want to emphasize them we've +already learned them for + + align:start position:0% +already learned them for + + + align:start position:0% +already learned them for +molecules they hold for bands and solids + + align:start position:0% +molecules they hold for bands and solids + + + align:start position:0% +molecules they hold for bands and solids +right so so now for example + + align:start position:0% +right so so now for example + + + align:start position:0% +right so so now for example +let's think about this each of these + + align:start position:0% +let's think about this each of these + + + align:start position:0% +let's think about this each of these +orbitals + + align:start position:0% +orbitals + + + align:start position:0% +orbitals +could occupy how many electrons + + align:start position:0% + + + + align:start position:0% + +two right so i had two electrons + + align:start position:0% +two right so i had two electrons + + + align:start position:0% +two right so i had two electrons +for each s orbital + + align:start position:0% +for each s orbital + + + align:start position:0% +for each s orbital +s orb well you know if you think about + + align:start position:0% +s orb well you know if you think about + + + align:start position:0% +s orb well you know if you think about +that then + + align:start position:0% +that then + + + align:start position:0% +that then +for n atoms for n atoms + + align:start position:0% +for n atoms for n atoms + + + align:start position:0% +for n atoms for n atoms +and here what did i say 10 to the 24th + + align:start position:0% +and here what did i say 10 to the 24th + + + align:start position:0% +and here what did i say 10 to the 24th +because + + align:start position:0% +because + + + align:start position:0% +because +there's one s orbital that comes from + + align:start position:0% +there's one s orbital that comes from + + + align:start position:0% +there's one s orbital that comes from +each atom + + align:start position:0% +each atom + + + align:start position:0% +each atom +so for n atoms then i would have two n + + align:start position:0% +so for n atoms then i would have two n + + + align:start position:0% +so for n atoms then i would have two n +electrons could go + + align:start position:0% + + + + align:start position:0% + +can go can go into + + align:start position:0% +can go can go into + + + align:start position:0% +can go can go into +the 1s band right so if i have + + align:start position:0% +the 1s band right so if i have + + + align:start position:0% +the 1s band right so if i have +oh that makes sense right because i had + + align:start position:0% +oh that makes sense right because i had + + + align:start position:0% +oh that makes sense right because i had +two for each orbital and i had that many + + align:start position:0% +two for each orbital and i had that many + + + align:start position:0% +two for each orbital and i had that many +so if i know how many atoms i have + + align:start position:0% +so if i know how many atoms i have + + + align:start position:0% +so if i know how many atoms i have +right that make up this solid then + + align:start position:0% +right that make up this solid then + + + align:start position:0% +right that make up this solid then +that's how many electrons that band can + + align:start position:0% +that's how many electrons that band can + + + align:start position:0% +that's how many electrons that band can +have in it + + align:start position:0% +have in it + + + align:start position:0% +have in it +all we did is is go from the orbital + + align:start position:0% +all we did is is go from the orbital + + + align:start position:0% +all we did is is go from the orbital +atomic orbital picture to the solid to + + align:start position:0% +atomic orbital picture to the solid to + + + align:start position:0% +atomic orbital picture to the solid to +the mole + + align:start position:0% +the mole + + + align:start position:0% +the mole +right okay why am i saying that well + + align:start position:0% +right okay why am i saying that well + + + align:start position:0% +right okay why am i saying that well +because + + align:start position:0% +because + + + align:start position:0% +because +filling filling is + + align:start position:0% +filling filling is + + + align:start position:0% +filling filling is +incredibly important and it happens in + + align:start position:0% +incredibly important and it happens in + + + align:start position:0% +incredibly important and it happens in +the same way just like it was so + + align:start position:0% +the same way just like it was so + + + align:start position:0% +the same way just like it was so +important for + + align:start position:0% +important for + + + align:start position:0% +important for +molecular orbitals it's also critical + + align:start position:0% +molecular orbitals it's also critical + + + align:start position:0% +molecular orbitals it's also critical +for bands + + align:start position:0% +for bands + + + align:start position:0% +for bands +so filling is like + + align:start position:0% +so filling is like + + + align:start position:0% +so filling is like +mo it's just like in mo's start + + align:start position:0% + + + + align:start position:0% + +from + + align:start position:0% + + + + align:start position:0% + +lowest energy lowest energy + + align:start position:0% + + + + align:start position:0% + +then fill up + + align:start position:0% + + + + align:start position:0% + +so you know if you think about this if i + + align:start position:0% +so you know if you think about this if i + + + align:start position:0% +so you know if you think about this if i +had + + align:start position:0% +had + + + align:start position:0% +had +now i'm gonna i'm gonna actually say + + align:start position:0% +now i'm gonna i'm gonna actually say + + + align:start position:0% +now i'm gonna i'm gonna actually say +well okay i made the 1s band + + align:start position:0% +well okay i made the 1s band + + + align:start position:0% +well okay i made the 1s band +by combining these orbitals now i'm + + align:start position:0% +by combining these orbitals now i'm + + + align:start position:0% +by combining these orbitals now i'm +going to say what a half + + align:start position:0% +going to say what a half + + + align:start position:0% +going to say what a half +which tells me how to fill it now i have + + align:start position:0% +which tells me how to fill it now i have + + + align:start position:0% +which tells me how to fill it now i have +hydrogen + + align:start position:0% +hydrogen + + + align:start position:0% +hydrogen +so if this is the 1s band if this is the + + align:start position:0% +so if this is the 1s band if this is the + + + align:start position:0% +so if this is the 1s band if this is the +1s + + align:start position:0% +1s + + + align:start position:0% +1s +band and i have + + align:start position:0% +band and i have + + + align:start position:0% +band and i have +hydrogen right + + align:start position:0% +hydrogen right + + + align:start position:0% +hydrogen right +so hydrogen has for each hydrogen + + align:start position:0% +so hydrogen has for each hydrogen + + + align:start position:0% +so hydrogen has for each hydrogen +i've got one electron but i just said + + align:start position:0% +i've got one electron but i just said + + + align:start position:0% +i've got one electron but i just said +that in the 1s band for each atom i + + align:start position:0% +that in the 1s band for each atom i + + + align:start position:0% +that in the 1s band for each atom i +could have put 2 electrons so you know + + align:start position:0% +could have put 2 electrons so you know + + + align:start position:0% +could have put 2 electrons so you know +if this is made of hydrogen + + align:start position:0% +if this is made of hydrogen + + + align:start position:0% +if this is made of hydrogen +that it's half filled which is exactly + + align:start position:0% +that it's half filled which is exactly + + + align:start position:0% +that it's half filled which is exactly +what that picture shows + + align:start position:0% +what that picture shows + + + align:start position:0% +what that picture shows +that's the filling you see it's filled + + align:start position:0% +that's the filling you see it's filled + + + align:start position:0% +that's the filling you see it's filled +halfway the band is filled halfway + + align:start position:0% +halfway the band is filled halfway + + + align:start position:0% +halfway the band is filled halfway +it it's it's like the mo picture + + align:start position:0% +it it's it's like the mo picture + + + align:start position:0% +it it's it's like the mo picture +right but it's not because i've made a + + align:start position:0% +right but it's not because i've made a + + + align:start position:0% +right but it's not because i've made a +continuous band out of it + + align:start position:0% +continuous band out of it + + + align:start position:0% +continuous band out of it +so instead of putting lines here lines + + align:start position:0% +so instead of putting lines here lines + + + align:start position:0% +so instead of putting lines here lines +there and then occupying them with + + align:start position:0% +there and then occupying them with + + + align:start position:0% +there and then occupying them with +arrows + + align:start position:0% +arrows + + + align:start position:0% +arrows +i fill them up with 10 to the 24th ish + + align:start position:0% +i fill them up with 10 to the 24th ish + + + align:start position:0% +i fill them up with 10 to the 24th ish +electrons so we fill bands up like that + + align:start position:0% +electrons so we fill bands up like that + + + align:start position:0% +electrons so we fill bands up like that +and we know that it's half filled + + align:start position:0% +and we know that it's half filled + + + align:start position:0% +and we know that it's half filled +because it's hydrogen + + align:start position:0% +because it's hydrogen + + + align:start position:0% +because it's hydrogen +another thing that we know is + + align:start position:0% +another thing that we know is + + + align:start position:0% +another thing that we know is +that the energy remember this + + align:start position:0% + + + + align:start position:0% + +this is also important right + + align:start position:0% +this is also important right + + + align:start position:0% +this is also important right +that that energy + + align:start position:0% +that that energy + + + align:start position:0% +that that energy +is related to interaction + + align:start position:0% +is related to interaction + + + align:start position:0% +is related to interaction +and overlap this is something we talked + + align:start position:0% +and overlap this is something we talked + + + align:start position:0% +and overlap this is something we talked +about interaction + + align:start position:0% +about interaction + + + align:start position:0% +about interaction +and overlap + + align:start position:0% + + + + align:start position:0% + +of the orbitals how how much does that + + align:start position:0% +of the orbitals how how much does that + + + align:start position:0% +of the orbitals how how much does that +band + + align:start position:0% +band + + + align:start position:0% +band +go up and down in energy right and + + align:start position:0% +go up and down in energy right and + + + align:start position:0% +go up and down in energy right and +something we talked about + + align:start position:0% +something we talked about + + + align:start position:0% +something we talked about +how much that band goes up and down in + + align:start position:0% +how much that band goes up and down in + + + align:start position:0% +how much that band goes up and down in +energy is just like in the the + + align:start position:0% +energy is just like in the the + + + align:start position:0% +energy is just like in the the +h2 molecule nicely 1s 1s sigma sigma + + align:start position:0% +h2 molecule nicely 1s 1s sigma sigma + + + align:start position:0% +h2 molecule nicely 1s 1s sigma sigma +star + + align:start position:0% +star + + + align:start position:0% +star +how far apart are sigma star in energy + + align:start position:0% +how far apart are sigma star in energy + + + align:start position:0% +how far apart are sigma star in energy +what depends + + align:start position:0% +what depends + + + align:start position:0% +what depends +on the interaction strength and the + + align:start position:0% +on the interaction strength and the + + + align:start position:0% +on the interaction strength and the +overlap between those orbitals + + align:start position:0% +overlap between those orbitals + + + align:start position:0% +overlap between those orbitals +the same is true in solids right same is + + align:start position:0% +the same is true in solids right same is + + + align:start position:0% +the same is true in solids right same is +true in solids so how + + align:start position:0% +true in solids so how + + + align:start position:0% +true in solids so how +what is the width of that band + + align:start position:0% +what is the width of that band + + + align:start position:0% +what is the width of that band +right how spread out over energy is it + + align:start position:0% +right how spread out over energy is it + + + align:start position:0% +right how spread out over energy is it +okay now so there's some ground rules + + align:start position:0% +okay now so there's some ground rules + + + align:start position:0% +okay now so there's some ground rules +now what else can we say okay so there's + + align:start position:0% +now what else can we say okay so there's + + + align:start position:0% +now what else can we say okay so there's +the + + align:start position:0% +the + + + align:start position:0% +the +absolute least bonding state + + align:start position:0% +absolute least bonding state + + + align:start position:0% +absolute least bonding state +anti-bonding all the way up there + + align:start position:0% +anti-bonding all the way up there + + + align:start position:0% +anti-bonding all the way up there +the most bonding and then you've got + + align:start position:0% +the most bonding and then you've got + + + align:start position:0% +the most bonding and then you've got +almost infinite number of possibilities + + align:start position:0% +almost infinite number of possibilities + + + align:start position:0% +almost infinite number of possibilities +in between + + align:start position:0% +in between + + + align:start position:0% +in between +right yeah but the thing is + + align:start position:0% +right yeah but the thing is + + + align:start position:0% +right yeah but the thing is +that filling determines + + align:start position:0% +that filling determines + + + align:start position:0% +that filling determines +the properties you you can't just know + + align:start position:0% +the properties you you can't just know + + + align:start position:0% +the properties you you can't just know +the bands or the band structure as it's + + align:start position:0% +the bands or the band structure as it's + + + align:start position:0% +the bands or the band structure as it's +called + + align:start position:0% +called + + + align:start position:0% +called +right but you have to know the filling + + align:start position:0% +right but you have to know the filling + + + align:start position:0% +right but you have to know the filling +and when you have a situation like this + + align:start position:0% +and when you have a situation like this + + + align:start position:0% +and when you have a situation like this +so what let's write this down + + align:start position:0% +so what let's write this down + + + align:start position:0% +so what let's write this down +when you have partial filling + + align:start position:0% + + + + align:start position:0% + +partially filled + + align:start position:0% +partially filled + + + align:start position:0% +partially filled +band is a metal + + align:start position:0% + + + + align:start position:0% + +and i will talk about metals on friday + + align:start position:0% +and i will talk about metals on friday + + + align:start position:0% +and i will talk about metals on friday +so we will come back to that concept and + + align:start position:0% +so we will come back to that concept and + + + align:start position:0% +so we will come back to that concept and +the electronic structure of metals + + align:start position:0% +the electronic structure of metals + + + align:start position:0% +the electronic structure of metals +on friday and but today + + align:start position:0% +on friday and but today + + + align:start position:0% +on friday and but today +i want to talk about something else that + + align:start position:0% +i want to talk about something else that + + + align:start position:0% +i want to talk about something else that +happens which is when + + align:start position:0% +happens which is when + + + align:start position:0% +happens which is when +you fill not in the middle of a band + + align:start position:0% +you fill not in the middle of a band + + + align:start position:0% +you fill not in the middle of a band +not in the middle but maybe all the way + + align:start position:0% +not in the middle but maybe all the way + + + align:start position:0% +not in the middle but maybe all the way +up to the top and there's a gap + + align:start position:0% +up to the top and there's a gap + + + align:start position:0% +up to the top and there's a gap +that's a different kind of material so + + align:start position:0% +that's a different kind of material so + + + align:start position:0% +that's a different kind of material so +if filling stops somewhere partially in + + align:start position:0% +if filling stops somewhere partially in + + + align:start position:0% +if filling stops somewhere partially in +the band in the middle of a band if + + align:start position:0% +the band in the middle of a band if + + + align:start position:0% +the band in the middle of a band if +you're filling you're counting + + align:start position:0% +you're filling you're counting + + + align:start position:0% +you're filling you're counting +and and you didn't go all the way up + + align:start position:0% +and and you didn't go all the way up + + + align:start position:0% +and and you didn't go all the way up +then you have a medal + + align:start position:0% +then you have a medal + + + align:start position:0% +then you have a medal +now but the thing is here we've only + + align:start position:0% +now but the thing is here we've only + + + align:start position:0% +now but the thing is here we've only +talked about one kind of band + + align:start position:0% +talked about one kind of band + + + align:start position:0% +talked about one kind of band +this is the s band what but every single + + align:start position:0% +this is the s band what but every single + + + align:start position:0% +this is the s band what but every single +one of these + + align:start position:0% +one of these + + + align:start position:0% +one of these +i can make i can make band look at this + + align:start position:0% +i can make i can make band look at this + + + align:start position:0% +i can make i can make band look at this +i can take + + align:start position:0% +i can take + + + align:start position:0% +i can take +a mole of orbitals and make an s + + align:start position:0% +a mole of orbitals and make an s + + + align:start position:0% +a mole of orbitals and make an s +band like that and then oh that was 1s + + align:start position:0% +band like that and then oh that was 1s + + + align:start position:0% +band like that and then oh that was 1s +here's 2s and look at this i can take + + align:start position:0% +here's 2s and look at this i can take + + + align:start position:0% +here's 2s and look at this i can take +the p electrons and make a p band + + align:start position:0% +the p electrons and make a p band + + + align:start position:0% +the p electrons and make a p band +p 2p band i can do this with every + + align:start position:0% +p 2p band i can do this with every + + + align:start position:0% +p 2p band i can do this with every +single 2s + + align:start position:0% +single 2s + + + align:start position:0% +single 2s +1s right so depending + + align:start position:0% +1s right so depending + + + align:start position:0% +1s right so depending +on a bunch of factors depending on a + + align:start position:0% +on a bunch of factors depending on a + + + align:start position:0% +on a bunch of factors depending on a +bunch of factors + + align:start position:0% +bunch of factors + + + align:start position:0% +bunch of factors +these bands could look different + + align:start position:0% +these bands could look different + + + align:start position:0% +these bands could look different +what does it depend on so this is yeah + + align:start position:0% +what does it depend on so this is yeah + + + align:start position:0% +what does it depend on so this is yeah +so the ba + + align:start position:0% +so the ba + + + align:start position:0% +so the ba +the way these bands are organized right + + align:start position:0% +the way these bands are organized right + + + align:start position:0% +the way these bands are organized right +we know now that + + align:start position:0% +we know now that + + + align:start position:0% +we know now that +that these orbitals will come together + + align:start position:0% +that these orbitals will come together + + + align:start position:0% +that these orbitals will come together +like i've drawn there and there + + align:start position:0% +like i've drawn there and there + + + align:start position:0% +like i've drawn there and there +and form bands what is the distance + + align:start position:0% +and form bands what is the distance + + + align:start position:0% +and form bands what is the distance +between these + + align:start position:0% +between these + + + align:start position:0% +between these +did they did they overlap maybe + + align:start position:0% +did they did they overlap maybe + + + align:start position:0% +did they did they overlap maybe +are they very far in energy right these + + align:start position:0% +are they very far in energy right these + + + align:start position:0% +are they very far in energy right these +things depend + + align:start position:0% +things depend + + + align:start position:0% +things depend +on adam + + align:start position:0% +on adam + + + align:start position:0% +on adam +depends on the atom + + align:start position:0% + + + + align:start position:0% + +and the bonding + + align:start position:0% + + + + align:start position:0% + +and the structure + + align:start position:0% +and the structure + + + align:start position:0% +and the structure +okay + + align:start position:0% + + + + align:start position:0% + +how do those bands look well it depends + + align:start position:0% +how do those bands look well it depends + + + align:start position:0% +how do those bands look well it depends +and we'll be talking about some examples + + align:start position:0% +and we'll be talking about some examples + + + align:start position:0% +and we'll be talking about some examples +but + + align:start position:0% +but + + + align:start position:0% +but +for now i want to focus on that filling + + align:start position:0% +for now i want to focus on that filling + + + align:start position:0% +for now i want to focus on that filling +thing again + + align:start position:0% +thing again + + + align:start position:0% +thing again +on that filling thing what happens + + align:start position:0% +on that filling thing what happens + + + align:start position:0% +on that filling thing what happens +if i you know i just did hi you know if + + align:start position:0% +if i you know i just did hi you know if + + + align:start position:0% +if i you know i just did hi you know if +i fill this 1s + + align:start position:0% +i fill this 1s + + + align:start position:0% +i fill this 1s +up to halfway it's a metal if i keep + + align:start position:0% +up to halfway it's a metal if i keep + + + align:start position:0% +up to halfway it's a metal if i keep +filling keep adding electrons and i fill + + align:start position:0% +filling keep adding electrons and i fill + + + align:start position:0% +filling keep adding electrons and i fill +this up halfway + + align:start position:0% +this up halfway + + + align:start position:0% +this up halfway +it's a metal but if i + + align:start position:0% +it's a metal but if i + + + align:start position:0% +it's a metal but if i +stop filling you know if i fill this + + align:start position:0% +stop filling you know if i fill this + + + align:start position:0% +stop filling you know if i fill this +and then i fill this and then there's + + align:start position:0% +and then i fill this and then there's + + + align:start position:0% +and then i fill this and then there's +some + + align:start position:0% +some + + + align:start position:0% +some +some space in energy and i didn't fill + + align:start position:0% +some space in energy and i didn't fill + + + align:start position:0% +some space in energy and i didn't fill +anymore that's not a metal + + align:start position:0% +anymore that's not a metal + + + align:start position:0% +anymore that's not a metal +that's not a metal so if there's a gap + + align:start position:0% +that's not a metal so if there's a gap + + + align:start position:0% +that's not a metal so if there's a gap +so there can be gaps between bands + + align:start position:0% +so there can be gaps between bands + + + align:start position:0% +so there can be gaps between bands +which i just showed you that's between + + align:start position:0% +which i just showed you that's between + + + align:start position:0% +which i just showed you that's between +an s and a p band + + align:start position:0% +an s and a p band + + + align:start position:0% +an s and a p band +right and then the filling determines + + align:start position:0% +right and then the filling determines + + + align:start position:0% +right and then the filling determines +the properties and they're so + + align:start position:0% +the properties and they're so + + + align:start position:0% +the properties and they're so +important right they're so important so + + align:start position:0% +important right they're so important so + + + align:start position:0% +important right they're so important so +let's talk about that i want to talk + + align:start position:0% +let's talk about that i want to talk + + + align:start position:0% +let's talk about that i want to talk +about these + + align:start position:0% +about these + + + align:start position:0% +about these +what we're going to do is we're going to + + align:start position:0% +what we're going to do is we're going to + + + align:start position:0% +what we're going to do is we're going to +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +semiconductors + + align:start position:0% + + + + align:start position:0% + +today and wednesday and medals on friday + + align:start position:0% +today and wednesday and medals on friday + + + align:start position:0% +today and wednesday and medals on friday +okay and we're going to see it through + + align:start position:0% +okay and we're going to see it through + + + align:start position:0% +okay and we're going to see it through +the vantage point of these electronic + + align:start position:0% +the vantage point of these electronic + + + align:start position:0% +the vantage point of these electronic +levels + + align:start position:0% +levels + + + align:start position:0% +levels +and the next week we'll see it through + + align:start position:0% +and the next week we'll see it through + + + align:start position:0% +and the next week we'll see it through +the vantage point of atoms + + align:start position:0% +the vantage point of atoms + + + align:start position:0% +the vantage point of atoms +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +if you have a gap well you always have + + align:start position:0% +if you have a gap well you always have + + + align:start position:0% +if you have a gap well you always have +gaps the question again comes to filling + + align:start position:0% +gaps the question again comes to filling + + + align:start position:0% +gaps the question again comes to filling +if the filling stops right if the + + align:start position:0% +if the filling stops right if the + + + align:start position:0% +if the filling stops right if the +filling stops + + align:start position:0% +filling stops + + + align:start position:0% +filling stops +uh let me write i want to define this + + align:start position:0% +uh let me write i want to define this + + + align:start position:0% +uh let me write i want to define this +very + + align:start position:0% +very + + + align:start position:0% +very +importantly so if the filling stops + + align:start position:0% +importantly so if the filling stops + + + align:start position:0% +importantly so if the filling stops +then you have this highest occupied + + align:start position:0% +then you have this highest occupied + + + align:start position:0% +then you have this highest occupied +level so let's suppose i have + + align:start position:0% +level so let's suppose i have + + + align:start position:0% +level so let's suppose i have +filling this is some band + + align:start position:0% +filling this is some band + + + align:start position:0% +filling this is some band +and this is some band and this is + + align:start position:0% +and this is some band and this is + + + align:start position:0% +and this is some band and this is +unoccupied + + align:start position:0% +unoccupied + + + align:start position:0% +unoccupied +so unoccupied by electrons + + align:start position:0% +so unoccupied by electrons + + + align:start position:0% +so unoccupied by electrons +this is fully occupied + + align:start position:0% +this is fully occupied + + + align:start position:0% +this is fully occupied +by electrons now + + align:start position:0% +by electrons now + + + align:start position:0% +by electrons now +so what's going to happen well first of + + align:start position:0% +so what's going to happen well first of + + + align:start position:0% +so what's going to happen well first of +all let's just get some + + align:start position:0% +all let's just get some + + + align:start position:0% +all let's just get some +some terms the last band + + align:start position:0% +some terms the last band + + + align:start position:0% +some terms the last band +that i filled the last band that i + + align:start position:0% +that i filled the last band that i + + + align:start position:0% +that i filled the last band that i +filled is called the valence band + + align:start position:0% + + + + align:start position:0% + +valence band and + + align:start position:0% +valence band and + + + align:start position:0% +valence band and +we use vb for short and + + align:start position:0% +we use vb for short and + + + align:start position:0% +we use vb for short and +the first band that i don't fill is + + align:start position:0% +the first band that i don't fill is + + + align:start position:0% +the first band that i don't fill is +called the conduction band + + align:start position:0% +called the conduction band + + + align:start position:0% +called the conduction band +and as we talk more about these + + align:start position:0% +and as we talk more about these + + + align:start position:0% +and as we talk more about these +materials + + align:start position:0% +materials + + + align:start position:0% +materials +you will see why they're called that + + align:start position:0% +you will see why they're called that + + + align:start position:0% +you will see why they're called that +conduction band + + align:start position:0% + + + + align:start position:0% + +but for now just just trust me in the in + + align:start position:0% +but for now just just trust me in the in + + + align:start position:0% +but for now just just trust me in the in +the labeling so + + align:start position:0% +the labeling so + + + align:start position:0% +the labeling so +the conduction band and the valence band + + align:start position:0% +the conduction band and the valence band + + + align:start position:0% +the conduction band and the valence band +depend on the filling + + align:start position:0% +depend on the filling + + + align:start position:0% +depend on the filling +because again it's you know it's where i + + align:start position:0% +because again it's you know it's where i + + + align:start position:0% +because again it's you know it's where i +filled two now + + align:start position:0% +filled two now + + + align:start position:0% +filled two now +the top level the very very top level + + align:start position:0% +the top level the very very top level + + + align:start position:0% +the top level the very very top level +out of these 10 to the 24th level + + align:start position:0% +out of these 10 to the 24th level + + + align:start position:0% +out of these 10 to the 24th level +that very top one has a special name + + align:start position:0% +that very top one has a special name + + + align:start position:0% +that very top one has a special name +it's the vb + + align:start position:0% +it's the vb + + + align:start position:0% +it's the vb +maximum that makes sense right it's the + + align:start position:0% +maximum that makes sense right it's the + + + align:start position:0% +maximum that makes sense right it's the +top valence band or the vbn + + align:start position:0% +top valence band or the vbn + + + align:start position:0% +top valence band or the vbn +and the one down here also has a special + + align:start position:0% +and the one down here also has a special + + + align:start position:0% +and the one down here also has a special +name it's the cb + + align:start position:0% +name it's the cb + + + align:start position:0% +name it's the cb +minimum minimum + + align:start position:0% +minimum minimum + + + align:start position:0% +minimum minimum +or cbm + + align:start position:0% +or cbm + + + align:start position:0% +or cbm +so the valence band maximum and the + + align:start position:0% +so the valence band maximum and the + + + align:start position:0% +so the valence band maximum and the +conduction minimum are + + align:start position:0% +conduction minimum are + + + align:start position:0% +conduction minimum are +you know it tells you if you think about + + align:start position:0% +you know it tells you if you think about + + + align:start position:0% +you know it tells you if you think about +it it tells you + + align:start position:0% +it it tells you + + + align:start position:0% +it it tells you +if you subtracted those energies between + + align:start position:0% +if you subtracted those energies between + + + align:start position:0% +if you subtracted those energies between +those parts of the band + + align:start position:0% +those parts of the band + + + align:start position:0% +those parts of the band +you'd get the distance and energy + + align:start position:0% +you'd get the distance and energy + + + align:start position:0% +you'd get the distance and energy +between the two bands right + + align:start position:0% + + + + align:start position:0% + +right so the conduction band minimum is + + align:start position:0% +right so the conduction band minimum is + + + align:start position:0% +right so the conduction band minimum is +this energy level here + + align:start position:0% +this energy level here + + + align:start position:0% +this energy level here +and the valence band maximum energy now + + align:start position:0% +and the valence band maximum energy now + + + align:start position:0% +and the valence band maximum energy now +remember valence electro it's called the + + align:start position:0% +remember valence electro it's called the + + + align:start position:0% +remember valence electro it's called the +valence band it makes sense because + + align:start position:0% +valence band it makes sense because + + + align:start position:0% +valence band it makes sense because +valence electrons + + align:start position:0% +valence electrons + + + align:start position:0% +valence electrons +remember are those ones as we talked + + align:start position:0% +remember are those ones as we talked + + + align:start position:0% +remember are those ones as we talked +about with lewis where + + align:start position:0% +about with lewis where + + + align:start position:0% +about with lewis where +you're you know you've got kind of the + + align:start position:0% +you're you know you've got kind of the + + + align:start position:0% +you're you know you've got kind of the +bonding and the action and the chemistry + + align:start position:0% +bonding and the action and the chemistry + + + align:start position:0% +bonding and the action and the chemistry +happening and so this is that top most + + align:start position:0% +happening and so this is that top most + + + align:start position:0% +happening and so this is that top most +state of the topmost valence band + + align:start position:0% +state of the topmost valence band + + + align:start position:0% +state of the topmost valence band +all right this is the valence band + + align:start position:0% +all right this is the valence band + + + align:start position:0% +all right this is the valence band +topmost state okay + + align:start position:0% +topmost state okay + + + align:start position:0% +topmost state okay +and there's one more definition we got + + align:start position:0% +and there's one more definition we got + + + align:start position:0% +and there's one more definition we got +to know about this is why we're setting + + align:start position:0% +to know about this is why we're setting + + + align:start position:0% +to know about this is why we're setting +this + + align:start position:0% +this + + + align:start position:0% +this +up which is that that energy difference + + align:start position:0% +up which is that that energy difference + + + align:start position:0% +up which is that that energy difference +here oh + + align:start position:0% +here oh + + + align:start position:0% +here oh +that is really important so + + align:start position:0% +that is really important so + + + align:start position:0% +that is really important so +the energy of the conduction band + + align:start position:0% +the energy of the conduction band + + + align:start position:0% +the energy of the conduction band +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +minus the energy of the valence band + + align:start position:0% +minus the energy of the valence band + + + align:start position:0% +minus the energy of the valence band +maximum + + align:start position:0% +maximum + + + align:start position:0% +maximum +is equal to something called the band + + align:start position:0% +is equal to something called the band + + + align:start position:0% +is equal to something called the band +gap + + align:start position:0% +gap + + + align:start position:0% +gap +energy gap it's the band gap + + align:start position:0% +energy gap it's the band gap + + + align:start position:0% +energy gap it's the band gap +band this is an extremely + + align:start position:0% +band this is an extremely + + + align:start position:0% +band this is an extremely +important property of materials + + align:start position:0% +important property of materials + + + align:start position:0% +important property of materials +the electronic band gap okay + + align:start position:0% +the electronic band gap okay + + + align:start position:0% +the electronic band gap okay +what is the energy difference between + + align:start position:0% +what is the energy difference between + + + align:start position:0% +what is the energy difference between +the highest occupied + + align:start position:0% +the highest occupied + + + align:start position:0% +the highest occupied +electrons and the lowest unoccupied + + align:start position:0% +electrons and the lowest unoccupied + + + align:start position:0% +electrons and the lowest unoccupied +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +that's what we're talking about + + align:start position:0% + + + + align:start position:0% + +so if + + align:start position:0% +so if + + + align:start position:0% +so if +that filling if that distance okay so + + align:start position:0% +that filling if that distance okay so + + + align:start position:0% +that filling if that distance okay so +here's + + align:start position:0% +here's + + + align:start position:0% +here's +here's an element carbon in the diamond + + align:start position:0% +here's an element carbon in the diamond + + + align:start position:0% +here's an element carbon in the diamond +structure + + align:start position:0% +structure + + + align:start position:0% +structure +and just not purple is filled + + align:start position:0% +and just not purple is filled + + + align:start position:0% +and just not purple is filled +and not purple is not filled so so you + + align:start position:0% +and not purple is not filled so so you + + + align:start position:0% +and not purple is not filled so so you +know that that's the conduction band + + align:start position:0% +know that that's the conduction band + + + align:start position:0% +know that that's the conduction band +right + + align:start position:0% +right + + + align:start position:0% +right +and that's the valence band and the band + + align:start position:0% +and that's the valence band and the band + + + align:start position:0% +and that's the valence band and the band +gap which we've just defined here + + align:start position:0% +gap which we've just defined here + + + align:start position:0% +gap which we've just defined here +is the energy difference between those + + align:start position:0% + + + + align:start position:0% + +and for diamond it's really large for + + align:start position:0% +and for diamond it's really large for + + + align:start position:0% +and for diamond it's really large for +diamond it's really large + + align:start position:0% +diamond it's really large + + + align:start position:0% +diamond it's really large +so you can see that in fact + + align:start position:0% +so you can see that in fact + + + align:start position:0% +so you can see that in fact +the gap is over if we converted this to + + align:start position:0% +the gap is over if we converted this to + + + align:start position:0% +the gap is over if we converted this to +electron volts it's more than + + align:start position:0% +electron volts it's more than + + + align:start position:0% +electron volts it's more than +is more than five electron volts more + + align:start position:0% +is more than five electron volts more + + + align:start position:0% +is more than five electron volts more +than five electron volts + + align:start position:0% +than five electron volts + + + align:start position:0% +than five electron volts +all right now i mentioned thermal energy + + align:start position:0% +all right now i mentioned thermal energy + + + align:start position:0% +all right now i mentioned thermal energy +in answer to the question about water + + align:start position:0% +in answer to the question about water + + + align:start position:0% +in answer to the question about water +right and room temperature so room + + align:start position:0% +right and room temperature so room + + + align:start position:0% +right and room temperature so room +temperature + + align:start position:0% + + + + align:start position:0% + +the energy of room temperature if you + + align:start position:0% +the energy of room temperature if you + + + align:start position:0% +the energy of room temperature if you +think about temperature as + + align:start position:0% +think about temperature as + + + align:start position:0% +think about temperature as +as an energy of like vibrational motion + + align:start position:0% +as an energy of like vibrational motion + + + align:start position:0% +as an energy of like vibrational motion +right + + align:start position:0% +right + + + align:start position:0% +right +and you can do that right you use + + align:start position:0% +and you can do that right you use + + + align:start position:0% +and you can do that right you use +something called the boltzmann constant + + align:start position:0% +something called the boltzmann constant + + + align:start position:0% +something called the boltzmann constant +and you can get what the room + + align:start position:0% +and you can get what the room + + + align:start position:0% +and you can get what the room +temperature energy is and it's something + + align:start position:0% +temperature energy is and it's something + + + align:start position:0% +temperature energy is and it's something +like 0.025 electron volts + + align:start position:0% +like 0.025 electron volts + + + align:start position:0% +like 0.025 electron volts +seems pretty small so the point is if + + align:start position:0% +seems pretty small so the point is if + + + align:start position:0% +seems pretty small so the point is if +that's the + + align:start position:0% +that's the + + + align:start position:0% +that's the +if that's the energy the thermal energy + + align:start position:0% +if that's the energy the thermal energy + + + align:start position:0% +if that's the energy the thermal energy +i have at room temperature + + align:start position:0% +i have at room temperature + + + align:start position:0% +i have at room temperature +then if my band gap is so much larger + + align:start position:0% +then if my band gap is so much larger + + + align:start position:0% +then if my band gap is so much larger +than that + + align:start position:0% +than that + + + align:start position:0% +than that +is so much larger than that it means + + align:start position:0% +is so much larger than that it means + + + align:start position:0% +is so much larger than that it means +those electrons are always going to be + + align:start position:0% +those electrons are always going to be + + + align:start position:0% +those electrons are always going to be +stuck + + align:start position:0% +stuck + + + align:start position:0% +stuck +they're never going to even in some + + align:start position:0% +they're never going to even in some + + + align:start position:0% +they're never going to even in some +accident + + align:start position:0% +accident + + + align:start position:0% +accident +have enough thermal energy to come up + + align:start position:0% +have enough thermal energy to come up + + + align:start position:0% +have enough thermal energy to come up +and be + + align:start position:0% +and be + + + align:start position:0% +and be +excited yeah we'll talk about this later + + align:start position:0% +excited yeah we'll talk about this later + + + align:start position:0% +excited yeah we'll talk about this later +so they're really stuck and and if if an + + align:start position:0% +so they're really stuck and and if if an + + + align:start position:0% +so they're really stuck and and if if an +electron is in the valence band it can't + + align:start position:0% +electron is in the valence band it can't + + + align:start position:0% +electron is in the valence band it can't +move very well + + align:start position:0% +move very well + + + align:start position:0% +move very well +it can't move it's kind of stuck in + + align:start position:0% +it can't move it's kind of stuck in + + + align:start position:0% +it can't move it's kind of stuck in +those bonds + + align:start position:0% +those bonds + + + align:start position:0% +those bonds +it's kind of stuck in those bonds and so + + align:start position:0% +it's kind of stuck in those bonds and so + + + align:start position:0% +it's kind of stuck in those bonds and so +here if there's electrons all stuck here + + align:start position:0% +here if there's electrons all stuck here + + + align:start position:0% +here if there's electrons all stuck here +and they never have a chance to go up + + align:start position:0% +and they never have a chance to go up + + + align:start position:0% +and they never have a chance to go up +here + + align:start position:0% +here + + + align:start position:0% +here +where they can travel freely this is + + align:start position:0% +where they can travel freely this is + + + align:start position:0% +where they can travel freely this is +really going to be an insulator + + align:start position:0% +really going to be an insulator + + + align:start position:0% +really going to be an insulator +this is not going to carry electrons + + align:start position:0% +this is not going to carry electrons + + + align:start position:0% +this is not going to carry electrons +through the material + + align:start position:0% +through the material + + + align:start position:0% +through the material +so that's an insulator when you have a + + align:start position:0% +so that's an insulator when you have a + + + align:start position:0% +so that's an insulator when you have a +very large band gap like that + + align:start position:0% +very large band gap like that + + + align:start position:0% +very large band gap like that +we call that an insulator + + align:start position:0% +we call that an insulator + + + align:start position:0% +we call that an insulator +okay but see if we compare and this is + + align:start position:0% +okay but see if we compare and this is + + + align:start position:0% +okay but see if we compare and this is +interesting you're just going down + + align:start position:0% +interesting you're just going down + + + align:start position:0% +interesting you're just going down +in the periodic table if you compare + + align:start position:0% +in the periodic table if you compare + + + align:start position:0% +in the periodic table if you compare +diamond to silicon + + align:start position:0% +diamond to silicon + + + align:start position:0% +diamond to silicon +to germanium right well see + + align:start position:0% +to germanium right well see + + + align:start position:0% +to germanium right well see +what happens is the band gap gets + + align:start position:0% +what happens is the band gap gets + + + align:start position:0% +what happens is the band gap gets +smaller i'm still + + align:start position:0% +smaller i'm still + + + align:start position:0% +smaller i'm still +filling them all the way up to the top + + align:start position:0% +filling them all the way up to the top + + + align:start position:0% +filling them all the way up to the top +of a band + + align:start position:0% +of a band + + + align:start position:0% +of a band +so i'm not a metal if i'm a metal + + align:start position:0% +so i'm not a metal if i'm a metal + + + align:start position:0% +so i'm not a metal if i'm a metal +it's because my filling stops somewhere + + align:start position:0% +it's because my filling stops somewhere + + + align:start position:0% +it's because my filling stops somewhere +in the middle of a band + + align:start position:0% +in the middle of a band + + + align:start position:0% +in the middle of a band +so i'm not a metal i'm a semiconductor + + align:start position:0% +so i'm not a metal i'm a semiconductor + + + align:start position:0% +so i'm not a metal i'm a semiconductor +and not an insulator and the reason i'm + + align:start position:0% +and not an insulator and the reason i'm + + + align:start position:0% +and not an insulator and the reason i'm +a semiconductor + + align:start position:0% +a semiconductor + + + align:start position:0% +a semiconductor +is that my band gap is kind of small + + align:start position:0% +is that my band gap is kind of small + + + align:start position:0% +is that my band gap is kind of small +enough so that + + align:start position:0% +enough so that + + + align:start position:0% +enough so that +electrons can kind of jump from here up + + align:start position:0% +electrons can kind of jump from here up + + + align:start position:0% +electrons can kind of jump from here up +to there + + align:start position:0% +to there + + + align:start position:0% +to there +sometimes sometimes + + align:start position:0% +sometimes sometimes + + + align:start position:0% +sometimes sometimes +that's why it's called a semiconductor + + align:start position:0% +that's why it's called a semiconductor + + + align:start position:0% +that's why it's called a semiconductor +there they kind of conduct electrons + + align:start position:0% +there they kind of conduct electrons + + + align:start position:0% +there they kind of conduct electrons +right so the electron + + align:start position:0% +right so the electron + + + align:start position:0% +right so the electron +can get up to the conduction band in a + + align:start position:0% +can get up to the conduction band in a + + + align:start position:0% +can get up to the conduction band in a +semiconductor + + align:start position:0% +semiconductor + + + align:start position:0% +semiconductor +more easily than an insulator and that's + + align:start position:0% +more easily than an insulator and that's + + + align:start position:0% +more easily than an insulator and that's +why it can conduct + + align:start position:0% +why it can conduct + + + align:start position:0% +why it can conduct +electricity much better than an + + align:start position:0% +electricity much better than an + + + align:start position:0% +electricity much better than an +insulator many many many orders of + + align:start position:0% +insulator many many many orders of + + + align:start position:0% +insulator many many many orders of +magnitude + + align:start position:0% +magnitude + + + align:start position:0% +magnitude +but the way that we have talked about + + align:start position:0% +but the way that we have talked about + + + align:start position:0% +but the way that we have talked about +getting electrons + + align:start position:0% +getting electrons + + + align:start position:0% +getting electrons +excited getting electrons excited is + + align:start position:0% +excited getting electrons excited is + + + align:start position:0% +excited getting electrons excited is +with light + + align:start position:0% +with light + + + align:start position:0% +with light +and we can do that for solids too we can + + align:start position:0% +and we can do that for solids too we can + + + align:start position:0% +and we can do that for solids too we can +do the same thing for solids + + align:start position:0% +do the same thing for solids + + + align:start position:0% +do the same thing for solids +right and so if i if i plot + + align:start position:0% +right and so if i if i plot + + + align:start position:0% +right and so if i if i plot +the absorption if i take a solid + + align:start position:0% +the absorption if i take a solid + + + align:start position:0% +the absorption if i take a solid +and i shine light on it there's + + align:start position:0% +and i shine light on it there's + + + align:start position:0% +and i shine light on it there's +something called the absorption + + align:start position:0% +something called the absorption + + + align:start position:0% +something called the absorption +coefficient + + align:start position:0% + + + + align:start position:0% + +the absorption coefficient which is + + align:start position:0% +the absorption coefficient which is + + + align:start position:0% +the absorption coefficient which is +really just + + align:start position:0% +really just + + + align:start position:0% +really just +a measure of how you know + + align:start position:0% +a measure of how you know + + + align:start position:0% +a measure of how you know +how far down into the solid did that + + align:start position:0% +how far down into the solid did that + + + align:start position:0% +how far down into the solid did that +light have to go + + align:start position:0% +light have to go + + + align:start position:0% +light have to go +before some electron got excited by it + + align:start position:0% +before some electron got excited by it + + + align:start position:0% +before some electron got excited by it +how well does it well okay different + + align:start position:0% +how well does it well okay different + + + align:start position:0% +how well does it well okay different +solids can absorb + + align:start position:0% +solids can absorb + + + align:start position:0% +solids can absorb +electrons differently but the main point + + align:start position:0% +electrons differently but the main point + + + align:start position:0% +electrons differently but the main point +is if i plot that versus energy + + align:start position:0% +is if i plot that versus energy + + + align:start position:0% +is if i plot that versus energy +you know for something like silicon + + align:start position:0% +you know for something like silicon + + + align:start position:0% +you know for something like silicon +the band gap of silicon is 1.1 ev + + align:start position:0% +the band gap of silicon is 1.1 ev + + + align:start position:0% +the band gap of silicon is 1.1 ev +so that's what it would look like for + + align:start position:0% +so that's what it would look like for + + + align:start position:0% +so that's what it would look like for +silicon because you know + + align:start position:0% + + + + align:start position:0% + +this should be wavelength + + align:start position:0% +this should be wavelength + + + align:start position:0% +this should be wavelength +wavelength because you know + + align:start position:0% + + + + align:start position:0% + +because as you get to lower so you know + + align:start position:0% +because as you get to lower so you know + + + align:start position:0% +because as you get to lower so you know +that above + + align:start position:0% + + + + align:start position:0% + +it's exactly like for atoms if i shine + + align:start position:0% +it's exactly like for atoms if i shine + + + align:start position:0% +it's exactly like for atoms if i shine +light like remember the bohr model if i + + align:start position:0% +light like remember the bohr model if i + + + align:start position:0% +light like remember the bohr model if i +shine light + + align:start position:0% +shine light + + + align:start position:0% +shine light +on an atom that has enough energy to + + align:start position:0% +on an atom that has enough energy to + + + align:start position:0% +on an atom that has enough energy to +promote it up + + align:start position:0% +promote it up + + + align:start position:0% +promote it up +then it can go right but the difference + + align:start position:0% +then it can go right but the difference + + + align:start position:0% +then it can go right but the difference +here + + align:start position:0% +here + + + align:start position:0% +here +is that for silicon + + align:start position:0% + + + + align:start position:0% + +see for silicon that's right there for + + align:start position:0% +see for silicon that's right there for + + + align:start position:0% +see for silicon that's right there for +silicon there's this big empty space + + align:start position:0% +silicon there's this big empty space + + + align:start position:0% +silicon there's this big empty space +with no bands + + align:start position:0% +with no bands + + + align:start position:0% +with no bands +it's just like the atom when there's no + + align:start position:0% +it's just like the atom when there's no + + + align:start position:0% +it's just like the atom when there's no +states + + align:start position:0% +states + + + align:start position:0% +states +i cannot have an electron there + + align:start position:0% +i cannot have an electron there + + + align:start position:0% +i cannot have an electron there +i'm stuck so the electron can be here or + + align:start position:0% +i'm stuck so the electron can be here or + + + align:start position:0% +i'm stuck so the electron can be here or +it can be here + + align:start position:0% +it can be here + + + align:start position:0% +it can be here +and so the light the energy of the light + + align:start position:0% +and so the light the energy of the light + + + align:start position:0% +and so the light the energy of the light +has to be at least the band gap + + align:start position:0% +has to be at least the band gap + + + align:start position:0% +has to be at least the band gap +to get it up at least the band gap to + + align:start position:0% +to get it up at least the band gap to + + + align:start position:0% +to get it up at least the band gap to +get it up + + align:start position:0% +get it up + + + align:start position:0% +get it up +right so what that means is that if i + + align:start position:0% +right so what that means is that if i + + + align:start position:0% +right so what that means is that if i +had + + align:start position:0% +had + + + align:start position:0% +had +so why does this go to zero with with + + align:start position:0% +so why does this go to zero with with + + + align:start position:0% +so why does this go to zero with with +increasing wavelength what it means is + + align:start position:0% +increasing wavelength what it means is + + + align:start position:0% +increasing wavelength what it means is +that if my + + align:start position:0% +that if my + + + align:start position:0% +that if my +valence band looks like this and my + + align:start position:0% +valence band looks like this and my + + + align:start position:0% +valence band looks like this and my +conduction band looks like this + + align:start position:0% +conduction band looks like this + + + align:start position:0% +conduction band looks like this +yeah and now my light is coming and i + + align:start position:0% +yeah and now my light is coming and i + + + align:start position:0% +yeah and now my light is coming and i +want to take an electron and promote it + + align:start position:0% +want to take an electron and promote it + + + align:start position:0% +want to take an electron and promote it +up + + align:start position:0% +up + + + align:start position:0% +up +well it cannot be the electron + + align:start position:0% +well it cannot be the electron + + + align:start position:0% +well it cannot be the electron +cannot be cannot exist + + align:start position:0% +cannot be cannot exist + + + align:start position:0% +cannot be cannot exist +in side the band gap + + align:start position:0% + + + + align:start position:0% + +there's no states there it's just like + + align:start position:0% +there's no states there it's just like + + + align:start position:0% +there's no states there it's just like +we talked about with atoms + + align:start position:0% +we talked about with atoms + + + align:start position:0% +we talked about with atoms +but now we've got almost infinite states + + align:start position:0% +but now we've got almost infinite states + + + align:start position:0% +but now we've got almost infinite states +here no states there + + align:start position:0% +here no states there + + + align:start position:0% +here no states there +and then again we start with infinite + + align:start position:0% +and then again we start with infinite + + + align:start position:0% +and then again we start with infinite +places where it can be + + align:start position:0% +places where it can be + + + align:start position:0% +places where it can be +right what that means is that if i shine + + align:start position:0% +right what that means is that if i shine + + + align:start position:0% +right what that means is that if i shine +light on it the only way silicon + + align:start position:0% +light on it the only way silicon + + + align:start position:0% +light on it the only way silicon +the only way it can absorb this light is + + align:start position:0% +the only way it can absorb this light is + + + align:start position:0% +the only way it can absorb this light is +if the light has + + align:start position:0% +if the light has + + + align:start position:0% +if the light has +energy greater than the band gap + + align:start position:0% +energy greater than the band gap + + + align:start position:0% +energy greater than the band gap +or wavelength less than the band gap + + align:start position:0% +or wavelength less than the band gap + + + align:start position:0% +or wavelength less than the band gap +that's why + + align:start position:0% +that's why + + + align:start position:0% +that's why +i drew it that way right so it goes to + + align:start position:0% +i drew it that way right so it goes to + + + align:start position:0% +i drew it that way right so it goes to +zero so it's going to absorb in + + align:start position:0% +zero so it's going to absorb in + + + align:start position:0% +zero so it's going to absorb in +wavelength up to a certain point + + align:start position:0% +wavelength up to a certain point + + + align:start position:0% +wavelength up to a certain point +and then if i go higher in wavelength + + align:start position:0% +and then if i go higher in wavelength + + + align:start position:0% +and then if i go higher in wavelength +those are energies that are too small + + align:start position:0% +those are energies that are too small + + + align:start position:0% +those are energies that are too small +it's going to like try to absorb here + + align:start position:0% +it's going to like try to absorb here + + + align:start position:0% +it's going to like try to absorb here +but there's nowhere to absorb to + + align:start position:0% +but there's nowhere to absorb to + + + align:start position:0% +but there's nowhere to absorb to +so it can't right but if it has enough + + align:start position:0% +so it can't right but if it has enough + + + align:start position:0% +so it can't right but if it has enough +energy oh look at this + + align:start position:0% +energy oh look at this + + + align:start position:0% +energy oh look at this +this is also different i could absorb + + align:start position:0% +this is also different i could absorb + + + align:start position:0% +this is also different i could absorb +here + + align:start position:0% +here + + + align:start position:0% +here +or here or here i can take all those + + align:start position:0% +or here or here i can take all those + + + align:start position:0% +or here or here i can take all those +higher energies and absorb + + align:start position:0% +higher energies and absorb + + + align:start position:0% +higher energies and absorb +light kind of continuously + + align:start position:0% +light kind of continuously + + + align:start position:0% +light kind of continuously +unlike in the atom where it could only + + align:start position:0% +unlike in the atom where it could only + + + align:start position:0% +unlike in the atom where it could only +be the level to hop you from n + + align:start position:0% +be the level to hop you from n + + + align:start position:0% +be the level to hop you from n +equals two to n equals four right but + + align:start position:0% +equals two to n equals four right but + + + align:start position:0% +equals two to n equals four right but +here i have + + align:start position:0% +here i have + + + align:start position:0% +here i have +an almost continuous set of states + + align:start position:0% +an almost continuous set of states + + + align:start position:0% +an almost continuous set of states +except in the band gap where i have no + + align:start position:0% +except in the band gap where i have no + + + align:start position:0% +except in the band gap where i have no +states + + align:start position:0% + + + + align:start position:0% + +so that's what the absorption would look + + align:start position:0% +so that's what the absorption would look + + + align:start position:0% +so that's what the absorption would look +like for silicon + + align:start position:0% +like for silicon + + + align:start position:0% +like for silicon +and if you look at the band gap this + + align:start position:0% +and if you look at the band gap this + + + align:start position:0% +and if you look at the band gap this +very very important quantity + + align:start position:0% +very very important quantity + + + align:start position:0% +very very important quantity +there's carbon there's diamond there's + + align:start position:0% +there's carbon there's diamond there's + + + align:start position:0% +there's carbon there's diamond there's +silicon + + align:start position:0% +silicon + + + align:start position:0% +silicon +there's germanium right and you can see + + align:start position:0% +there's germanium right and you can see + + + align:start position:0% +there's germanium right and you can see +that as you go + + align:start position:0% +that as you go + + + align:start position:0% +that as you go +to heavier and heavier elements + + align:start position:0% +to heavier and heavier elements + + + align:start position:0% +to heavier and heavier elements +you change the gap + + align:start position:0% +you change the gap + + + align:start position:0% +you change the gap +you can understand this from what you + + align:start position:0% +you can understand this from what you + + + align:start position:0% +you can understand this from what you +know about the electron levels in atoms + + align:start position:0% +know about the electron levels in atoms + + + align:start position:0% +know about the electron levels in atoms +because in an atom + + align:start position:0% +because in an atom + + + align:start position:0% +because in an atom +right in an atom remember as a + + align:start position:0% +right in an atom remember as a + + + align:start position:0% +right in an atom remember as a +you know if i get heavier and heavier + + align:start position:0% +you know if i get heavier and heavier + + + align:start position:0% +you know if i get heavier and heavier +those electrons + + align:start position:0% +those electrons + + + align:start position:0% +those electrons +all the way on the outer uh you know the + + align:start position:0% +all the way on the outer uh you know the + + + align:start position:0% +all the way on the outer uh you know the +outer edges of the atom they're more + + align:start position:0% +outer edges of the atom they're more + + + align:start position:0% +outer edges of the atom they're more +weakly + + align:start position:0% +weakly + + + align:start position:0% +weakly +bonded to the atom right they're weaker + + align:start position:0% +bonded to the atom right they're weaker + + + align:start position:0% +bonded to the atom right they're weaker +and weaker and weaker + + align:start position:0% +and weaker and weaker + + + align:start position:0% +and weaker and weaker +right so the energy is higher and higher + + align:start position:0% +right so the energy is higher and higher + + + align:start position:0% +right so the energy is higher and higher +remember it like so it's like instead of + + align:start position:0% +remember it like so it's like instead of + + + align:start position:0% +remember it like so it's like instead of +being these deeper energy levels that + + align:start position:0% +being these deeper energy levels that + + + align:start position:0% +being these deeper energy levels that +have more body + + align:start position:0% +have more body + + + align:start position:0% +have more body +more energy in them lower in energy + + align:start position:0% +more energy in them lower in energy + + + align:start position:0% +more energy in them lower in energy +they're less and less energy + + align:start position:0% +they're less and less energy + + + align:start position:0% +they're less and less energy +right well so you can you can imagine + + align:start position:0% +right well so you can you can imagine + + + align:start position:0% +right well so you can you can imagine +now + + align:start position:0% +now + + + align:start position:0% +now +that those are what you're starting with + + align:start position:0% +that those are what you're starting with + + + align:start position:0% +that those are what you're starting with +those are what you're starting with + + align:start position:0% +those are what you're starting with + + + align:start position:0% +those are what you're starting with +these right these are the atom levels + + align:start position:0% +these right these are the atom levels + + + align:start position:0% +these right these are the atom levels +that you're starting with so if you're + + align:start position:0% +that you're starting with so if you're + + + align:start position:0% +that you're starting with so if you're +going to make your atom + + align:start position:0% +going to make your atom + + + align:start position:0% +going to make your atom +have electrons that are more weakly + + align:start position:0% +have electrons that are more weakly + + + align:start position:0% +have electrons that are more weakly +bound + + align:start position:0% +bound + + + align:start position:0% +bound +with energies that are higher that + + align:start position:0% +with energies that are higher that + + + align:start position:0% +with energies that are higher that +aren't as deep and don't have as much + + align:start position:0% +aren't as deep and don't have as much + + + align:start position:0% +aren't as deep and don't have as much +distance between them + + align:start position:0% +distance between them + + + align:start position:0% +distance between them +right in the energy landscape then the + + align:start position:0% +right in the energy landscape then the + + + align:start position:0% +right in the energy landscape then the +gaps will get smaller + + align:start position:0% +gaps will get smaller + + + align:start position:0% +gaps will get smaller +now that is a very simple picture + + align:start position:0% +now that is a very simple picture + + + align:start position:0% +now that is a very simple picture +a very simple picture of why the gaps + + align:start position:0% +a very simple picture of why the gaps + + + align:start position:0% +a very simple picture of why the gaps +get smaller it happens to work for this + + align:start position:0% +get smaller it happens to work for this + + + align:start position:0% +get smaller it happens to work for this +column + + align:start position:0% +column + + + align:start position:0% +column +right so you know if you look at this + + align:start position:0% +right so you know if you look at this + + + align:start position:0% +right so you know if you look at this +and some people would even call this an + + align:start position:0% +and some people would even call this an + + + align:start position:0% +and some people would even call this an +um a metal because that's such a small + + align:start position:0% +um a metal because that's such a small + + + align:start position:0% +um a metal because that's such a small +gap but i like to call it a + + align:start position:0% +gap but i like to call it a + + + align:start position:0% +gap but i like to call it a +semiconductor + + align:start position:0% +semiconductor + + + align:start position:0% +semiconductor +right but if your gap is zero if your + + align:start position:0% +right but if your gap is zero if your + + + align:start position:0% +right but if your gap is zero if your +band gap is zero + + align:start position:0% +band gap is zero + + + align:start position:0% +band gap is zero +it means there's no gap so + + align:start position:0% +it means there's no gap so + + + align:start position:0% +it means there's no gap so +by definition you're in the middle of a + + align:start position:0% +by definition you're in the middle of a + + + align:start position:0% +by definition you're in the middle of a +band + + align:start position:0% +band + + + align:start position:0% +band +you're somewhere in the middle of a band + + align:start position:0% +you're somewhere in the middle of a band + + + align:start position:0% +you're somewhere in the middle of a band +and if you're in the middle of a band + + align:start position:0% +and if you're in the middle of a band + + + align:start position:0% +and if you're in the middle of a band +you're a medal you didn't fill that band + + align:start position:0% +you're a medal you didn't fill that band + + + align:start position:0% +you're a medal you didn't fill that band +all the way up right + + align:start position:0% +all the way up right + + + align:start position:0% +all the way up right +but if you filled it up and then there's + + align:start position:0% +but if you filled it up and then there's + + + align:start position:0% +but if you filled it up and then there's +a little gap between you and the next + + align:start position:0% +a little gap between you and the next + + + align:start position:0% +a little gap between you and the next +level + + align:start position:0% +level + + + align:start position:0% +level +then you're a semiconductor or if it's + + align:start position:0% +then you're a semiconductor or if it's + + + align:start position:0% +then you're a semiconductor or if it's +much greater + + align:start position:0% +much greater + + + align:start position:0% +much greater +like greater than three electron volts + + align:start position:0% +like greater than three electron volts + + + align:start position:0% +like greater than three electron volts +three and a half electron volts + + align:start position:0% +three and a half electron volts + + + align:start position:0% +three and a half electron volts +then you're an insulator okay + + align:start position:0% +then you're an insulator okay + + + align:start position:0% +then you're an insulator okay +now so you can imagine now why right so + + align:start position:0% +now so you can imagine now why right so + + + align:start position:0% +now so you can imagine now why right so +as the as the interactions get stronger + + align:start position:0% +as the as the interactions get stronger + + + align:start position:0% +as the as the interactions get stronger +you can imagine those distances can get + + align:start position:0% +you can imagine those distances can get + + + align:start position:0% +you can imagine those distances can get +larger + + align:start position:0% +larger + + + align:start position:0% +larger +and so you could have larger and larger + + align:start position:0% +and so you could have larger and larger + + + align:start position:0% +and so you could have larger and larger +gaps which can explain this trend + + align:start position:0% +gaps which can explain this trend + + + align:start position:0% +gaps which can explain this trend +but as i said before where did i put it + + align:start position:0% +but as i said before where did i put it + + + align:start position:0% +but as i said before where did i put it +it depends + + align:start position:0% +it depends + + + align:start position:0% +it depends +not just on the atom and the original + + align:start position:0% +not just on the atom and the original + + + align:start position:0% +not just on the atom and the original +energy levels but on how those bond + + align:start position:0% +energy levels but on how those bond + + + align:start position:0% +energy levels but on how those bond +together and we'll talk about that on + + align:start position:0% +together and we'll talk about that on + + + align:start position:0% +together and we'll talk about that on +wednesday + + align:start position:0% +wednesday + + + align:start position:0% +wednesday +and it also depends on the structure + + align:start position:0% +and it also depends on the structure + + + align:start position:0% +and it also depends on the structure +which we'll talk about next week + + align:start position:0% +which we'll talk about next week + + + align:start position:0% +which we'll talk about next week +so it's not just as simple as that but + + align:start position:0% +so it's not just as simple as that but + + + align:start position:0% +so it's not just as simple as that but +you can understand + + align:start position:0% +you can understand + + + align:start position:0% +you can understand +you know basic trends this way for some + + align:start position:0% +you know basic trends this way for some + + + align:start position:0% +you know basic trends this way for some +of the columns + + align:start position:0% +of the columns + + + align:start position:0% +of the columns +okay now um okay we'll get to that on on + + align:start position:0% +okay now um okay we'll get to that on on + + + align:start position:0% +okay now um okay we'll get to that on on +friday um now the goody bag gives you a + + align:start position:0% +friday um now the goody bag gives you a + + + align:start position:0% +friday um now the goody bag gives you a +way + + align:start position:0% +way + + + align:start position:0% +way +to probe this so what's in the goodie + + align:start position:0% +to probe this so what's in the goodie + + + align:start position:0% +to probe this so what's in the goodie +bag the goodie bag has + + align:start position:0% +bag the goodie bag has + + + align:start position:0% +bag the goodie bag has +a way of measuring conductivity now i + + align:start position:0% +a way of measuring conductivity now i + + + align:start position:0% +a way of measuring conductivity now i +just told you that you cannot get + + align:start position:0% +just told you that you cannot get + + + align:start position:0% +just told you that you cannot get +connectivity unless you have electrons + + align:start position:0% +connectivity unless you have electrons + + + align:start position:0% +connectivity unless you have electrons +that are able to make this jump + + align:start position:0% +that are able to make this jump + + + align:start position:0% +that are able to make this jump +to make this jump they've got to be able + + align:start position:0% +to make this jump they've got to be able + + + align:start position:0% +to make this jump they've got to be able +to go up + + align:start position:0% +to go up + + + align:start position:0% +to go up +from the valence band to the conduction + + align:start position:0% +from the valence band to the conduction + + + align:start position:0% +from the valence band to the conduction +band if they don't + + align:start position:0% +band if they don't + + + align:start position:0% +band if they don't +do that they're not free they're stuck + + align:start position:0% +do that they're not free they're stuck + + + align:start position:0% +do that they're not free they're stuck +in these bonds + + align:start position:0% +in these bonds + + + align:start position:0% +in these bonds +right you got to get them free so they + + align:start position:0% +right you got to get them free so they + + + align:start position:0% +right you got to get them free so they +can roam around + + align:start position:0% +can roam around + + + align:start position:0% +can roam around +and not be stuck in this bond or that + + align:start position:0% +and not be stuck in this bond or that + + + align:start position:0% +and not be stuck in this bond or that +bond right + + align:start position:0% +bond right + + + align:start position:0% +bond right +this measures that this measures that + + align:start position:0% +this measures that this measures that + + + align:start position:0% +this measures that this measures that +right this measures whether electrons + + align:start position:0% +right this measures whether electrons + + + align:start position:0% +right this measures whether electrons +are in the conduction band + + align:start position:0% +are in the conduction band + + + align:start position:0% +are in the conduction band +you've also got some leds and some leds + + align:start position:0% +you've also got some leds and some leds + + + align:start position:0% +you've also got some leds and some leds +and this is the critical piece here why + + align:start position:0% +and this is the critical piece here why + + + align:start position:0% +and this is the critical piece here why +do you have + + align:start position:0% +do you have + + + align:start position:0% +do you have +two kinds of leds because on the one + + align:start position:0% +two kinds of leds because on the one + + + align:start position:0% +two kinds of leds because on the one +hand + + align:start position:0% +hand + + + align:start position:0% +hand +what you're doing i'm giving you a way + + align:start position:0% +what you're doing i'm giving you a way + + + align:start position:0% +what you're doing i'm giving you a way +to excite + + align:start position:0% +to excite + + + align:start position:0% +to excite +electrons so i'm giving you a way + + align:start position:0% +electrons so i'm giving you a way + + + align:start position:0% +electrons so i'm giving you a way +to actually promote electrons so you've + + align:start position:0% +to actually promote electrons so you've + + + align:start position:0% +to actually promote electrons so you've +got 10 to the 24th electrons in this + + align:start position:0% +got 10 to the 24th electrons in this + + + align:start position:0% +got 10 to the 24th electrons in this +valence band + + align:start position:0% +valence band + + + align:start position:0% +valence band +this would be the vb and this would be + + align:start position:0% +this would be the vb and this would be + + + align:start position:0% +this would be the vb and this would be +the cb + + align:start position:0% +the cb + + + align:start position:0% +the cb +and what you're doing is you're shining + + align:start position:0% +and what you're doing is you're shining + + + align:start position:0% +and what you're doing is you're shining +light + + align:start position:0% +light + + + align:start position:0% +light +right with different frequencies which + + align:start position:0% +right with different frequencies which + + + align:start position:0% +right with different frequencies which +means different energies + + align:start position:0% +means different energies + + + align:start position:0% +means different energies +okay that's what the right hand side + + align:start position:0% +okay that's what the right hand side + + + align:start position:0% +okay that's what the right hand side +gives you it gives you + + align:start position:0% +gives you it gives you + + + align:start position:0% +gives you it gives you +different energies of the photons so you + + align:start position:0% +different energies of the photons so you + + + align:start position:0% +different energies of the photons so you +have a way now + + align:start position:0% +have a way now + + + align:start position:0% +have a way now +of shining energy on a semiconductor and + + align:start position:0% +of shining energy on a semiconductor and + + + align:start position:0% +of shining energy on a semiconductor and +that's the second piece + + align:start position:0% +that's the second piece + + + align:start position:0% +that's the second piece +the semiconductor is what an led is + + align:start position:0% +the semiconductor is what an led is + + + align:start position:0% +the semiconductor is what an led is +it's a semiconductor if leds were + + align:start position:0% +it's a semiconductor if leds were + + + align:start position:0% +it's a semiconductor if leds were +insulators they wouldn't work and if + + align:start position:0% +insulators they wouldn't work and if + + + align:start position:0% +insulators they wouldn't work and if +they're metals they wouldn't work + + align:start position:0% +they're metals they wouldn't work + + + align:start position:0% +they're metals they wouldn't work +because the way an led works is actually + + align:start position:0% +because the way an led works is actually + + + align:start position:0% +because the way an led works is actually +just the opposite + + align:start position:0% +just the opposite + + + align:start position:0% +just the opposite +here i'm shining light so that an + + align:start position:0% +here i'm shining light so that an + + + align:start position:0% +here i'm shining light so that an +electron gets promoted and i can measure + + align:start position:0% +electron gets promoted and i can measure + + + align:start position:0% +electron gets promoted and i can measure +that + + align:start position:0% +that + + + align:start position:0% +that +with my my voltmeter but i could also + + align:start position:0% +with my my voltmeter but i could also + + + align:start position:0% +with my my voltmeter but i could also +put electrons in with a current that + + align:start position:0% +put electrons in with a current that + + + align:start position:0% +put electrons in with a current that +gets them up here + + align:start position:0% +gets them up here + + + align:start position:0% +gets them up here +and then they drop down and emit a + + align:start position:0% +and then they drop down and emit a + + + align:start position:0% +and then they drop down and emit a +photon that's what an led is + + align:start position:0% +photon that's what an led is + + + align:start position:0% +photon that's what an led is +right that's what an led is it's just + + align:start position:0% +right that's what an led is it's just + + + align:start position:0% +right that's what an led is it's just +the reverse and so what i've given you + + align:start position:0% +the reverse and so what i've given you + + + align:start position:0% +the reverse and so what i've given you +on the left + + align:start position:0% +on the left + + + align:start position:0% +on the left +are different semiconductors + + align:start position:0% +are different semiconductors + + + align:start position:0% +are different semiconductors +because you see just just like a + + align:start position:0% +because you see just just like a + + + align:start position:0% +because you see just just like a +different you know + + align:start position:0% +different you know + + + align:start position:0% +different you know +if i'm running current through like i am + + align:start position:0% +if i'm running current through like i am + + + align:start position:0% +if i'm running current through like i am +on the right you see those are different + + align:start position:0% +on the right you see those are different + + + align:start position:0% +on the right you see those are different +colors + + align:start position:0% +colors + + + align:start position:0% +colors +that means that i must have different + + align:start position:0% +that means that i must have different + + + align:start position:0% +that means that i must have different +gaps + + align:start position:0% +gaps + + + align:start position:0% +gaps +you know that you know that already from + + align:start position:0% +you know that you know that already from + + + align:start position:0% +you know that you know that already from +the work we did with bohr + + align:start position:0% +the work we did with bohr + + + align:start position:0% +the work we did with bohr +and the color or frequency of light that + + align:start position:0% +and the color or frequency of light that + + + align:start position:0% +and the color or frequency of light that +you could get out of different + + align:start position:0% +you could get out of different + + + align:start position:0% +you could get out of different +transitions + + align:start position:0% +transitions + + + align:start position:0% +transitions +but it's the same here did an electron + + align:start position:0% +but it's the same here did an electron + + + align:start position:0% +but it's the same here did an electron +you know did i put an electron up here + + align:start position:0% +you know did i put an electron up here + + + align:start position:0% +you know did i put an electron up here +and then it fell down and gave off some + + align:start position:0% +and then it fell down and gave off some + + + align:start position:0% +and then it fell down and gave off some +lambda + + align:start position:0% +lambda + + + align:start position:0% +lambda +right that lambda has to equal the + + align:start position:0% +right that lambda has to equal the + + + align:start position:0% +right that lambda has to equal the +difference between + + align:start position:0% +difference between + + + align:start position:0% +difference between +the i mean it just equals the band gap + + align:start position:0% +the i mean it just equals the band gap + + + align:start position:0% +the i mean it just equals the band gap +right it equals the band gap + + align:start position:0% +right it equals the band gap + + + align:start position:0% +right it equals the band gap +because the electron was put up to here + + align:start position:0% +because the electron was put up to here + + + align:start position:0% +because the electron was put up to here +in the cbm and then it drops down to the + + align:start position:0% +in the cbm and then it drops down to the + + + align:start position:0% +in the cbm and then it drops down to the +vbm and it emits a photon that's what's + + align:start position:0% +vbm and it emits a photon that's what's + + + align:start position:0% +vbm and it emits a photon that's what's +happening on the right-hand side but see + + align:start position:0% +happening on the right-hand side but see + + + align:start position:0% +happening on the right-hand side but see +you've also got on the left-hand side + + align:start position:0% +you've also got on the left-hand side + + + align:start position:0% +you've also got on the left-hand side +you've got sensors + + align:start position:0% + + + + align:start position:0% + +because it's just leds on the left see + + align:start position:0% +because it's just leds on the left see + + + align:start position:0% +because it's just leds on the left see +but if i hook those + + align:start position:0% +but if i hook those + + + align:start position:0% +but if i hook those +up if i hook those up to + + align:start position:0% +up if i hook those up to + + + align:start position:0% +up if i hook those up to +uh the voltmeter well i'm hooking up a + + align:start position:0% +uh the voltmeter well i'm hooking up a + + + align:start position:0% +uh the voltmeter well i'm hooking up a +semiconductor to a voltmeter + + align:start position:0% +semiconductor to a voltmeter + + + align:start position:0% +semiconductor to a voltmeter +so i'm hooking this up and i'm reading + + align:start position:0% +so i'm hooking this up and i'm reading + + + align:start position:0% +so i'm hooking this up and i'm reading +is there any current + + align:start position:0% +is there any current + + + align:start position:0% +is there any current +yeah and the answer in a dark room is no + + align:start position:0% +yeah and the answer in a dark room is no + + + align:start position:0% +yeah and the answer in a dark room is no +unless you make it really really hot + + align:start position:0% +unless you make it really really hot + + + align:start position:0% +unless you make it really really hot +don't + + align:start position:0% +don't + + + align:start position:0% +don't +because you have to go to very high + + align:start position:0% +because you have to go to very high + + + align:start position:0% +because you have to go to very high +temperature but what if i shine light on + + align:start position:0% +temperature but what if i shine light on + + + align:start position:0% +temperature but what if i shine light on +this now + + align:start position:0% +this now + + + align:start position:0% +this now +well if i shine light that has the right + + align:start position:0% +well if i shine light that has the right + + + align:start position:0% +well if i shine light that has the right +energy + + align:start position:0% +energy + + + align:start position:0% +energy +to put electrons up in the in the cbm + + align:start position:0% +to put electrons up in the in the cbm + + + align:start position:0% +to put electrons up in the in the cbm +from the vbm then i'll read something on + + align:start position:0% +from the vbm then i'll read something on + + + align:start position:0% +from the vbm then i'll read something on +the voltmeter + + align:start position:0% +the voltmeter + + + align:start position:0% +the voltmeter +so by giving you different leds on the + + align:start position:0% +so by giving you different leds on the + + + align:start position:0% +so by giving you different leds on the +left + + align:start position:0% +left + + + align:start position:0% +left +i'm giving you different band gaps you + + align:start position:0% +i'm giving you different band gaps you + + + align:start position:0% +i'm giving you different band gaps you +have in your hands + + align:start position:0% +have in your hands + + + align:start position:0% +have in your hands +different semiconductor band gaps and by + + align:start position:0% +different semiconductor band gaps and by + + + align:start position:0% +different semiconductor band gaps and by +reading whether + + align:start position:0% +reading whether + + + align:start position:0% +reading whether +there are electrons in here or not you + + align:start position:0% +there are electrons in here or not you + + + align:start position:0% +there are electrons in here or not you +can tell what + + align:start position:0% +can tell what + + + align:start position:0% +can tell what +frequency of light i shined on them so + + align:start position:0% +frequency of light i shined on them so + + + align:start position:0% +frequency of light i shined on them so +they're both + + align:start position:0% +they're both + + + align:start position:0% +they're both +emitters of photons and detectors of + + align:start position:0% +emitters of photons and detectors of + + + align:start position:0% +emitters of photons and detectors of +photons + + align:start position:0% +photons + + + align:start position:0% +photons +and it all comes together because you + + align:start position:0% +and it all comes together because you + + + align:start position:0% +and it all comes together because you +have a semiconductor + + align:start position:0% +have a semiconductor + + + align:start position:0% +have a semiconductor +which happened because you took 10 to + + align:start position:0% +which happened because you took 10 to + + + align:start position:0% +which happened because you took 10 to +the 24 states + + align:start position:0% +the 24 states + + + align:start position:0% +the 24 states +you put them together you had gaps + + align:start position:0% +you put them together you had gaps + + + align:start position:0% +you put them together you had gaps +between them and you filled all the way + + align:start position:0% +between them and you filled all the way + + + align:start position:0% +between them and you filled all the way +up + + align:start position:0% +up + + + align:start position:0% +up +to one of those gaps and that gap was + + align:start position:0% +to one of those gaps and that gap was + + + align:start position:0% +to one of those gaps and that gap was +around one + + align:start position:0% +around one + + + align:start position:0% +around one +or two electron volts we will pick this + + align:start position:0% +or two electron volts we will pick this + + + align:start position:0% +or two electron volts we will pick this +up + + align:start position:0% +up + + + align:start position:0% +up +on friday and go further i mean on + + align:start position:0% +on friday and go further i mean on + + + align:start position:0% +on friday and go further i mean on +wednesday on wednesday + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/E2HglWZcfKw.txt b/E2HglWZcfKw.txt new file mode 100644 index 0000000000000000000000000000000000000000..1efee84087cc0a1f56d22083738232eb65aeb682 --- /dev/null +++ b/E2HglWZcfKw.txt @@ -0,0 +1,2494 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at ocw dot + +MIT dot edu. + +PROFESSOR: Ladies and gentlemen, +welcome to lecture + +number six. + +In this lecture I would like +to discuss with you the + +formulation and calculation of +isoparametric finite elements. + +We considered earlier already, +in lecture four, the + +calculation all finite +element matrices. + +But in that lecture we +considered the generalized + +coordinate finite +element models. + +The generalized coordinate +finite element models were the + +first finite elements derived. + +However, I now want to discuss +with you a more general + +approach of deriving the +required interpolation + +matrices and element matrices. + +And this more general approach +is the isoparametric finite + +element derivation. + +The isoparametric finite +elements that I will be + +discussing in this and the +next lecture are, in my + +opinion, the most effective +elements currently available + +for plane stress, plane strain, +axisymmetric analysis, + +three dimensional analysis, +thick and thin shell analysis. + +These elements are being used, +for example, in the computer + +program [? Aldena ?]. + +They are also used in other +computer programs and + +represent a modern approach +to the solution + +off structure problems. + +In this lecture, I would like +to talk about the derivation + +of continuum elements. + +In the next lecture we will talk +about the derivation of + +structural elements, [INAUDIBLE] +and central + +elements, beam elements. + +The basic concept of +isoparametric finite element + +analysis, is that we interpolate +the geometry of an + +element, and the displacements +of an element in + +exactly the same way. + +Let us look at the geometry +interpolation. + +Here you see for three +dimensional analysis, the + +interpolation of the +x-coordinate within the + +element, where we use +interpolation functions h i. + +Of course these interpolation +functions are unknown and I + +will have to show you +how we derive + +them for certain elements. + +The x i as a nodal +point coordinate. + +The x i value for i equals 1, +for example, is nothing else + +than the x-coordinate +of nodal point one. + +And so on. + +So the x i, the nodal point +coordinates for all nodes, + +they are given, they are input +in the analysis the way we + +have been discussing it in +the previous lecture. + +And if we know the h i, we have +a direct relationship for + +the x-coordinates within the +element, as a function of the + +nodal point coordinates. + +Again, I have to show you how +we obtain the h i functions + +for the various elements +that we are using. + +Similarly, for the y +interpolation and similarly + +for the z interpolation. + +Having derived the h i functions +we are using in the + +isoparametric finite element, +the same functions also to + +interpolate the displacements. + +Notice that we're having here, +the nodal point displacements + +u i, v i, and w i, and here we +have the same interpolation + +functions that we already +used in the coordinate + +interpolations. + +And if the number of nodes +that are used in the + +description of the element-- + +and, in fact, we will see that N +can be a variable, it can be + +equal to three, four, five, up +to a large number of nodes. + +And in practice we generally +don't go much further than 60. + +I mentioned that I want to +discuss in this lecture + +continuum elements. + +Well, the continuum elements +that we addressing ourselves + +to are the truss element, the +two d elements-- plane stress, + +plane strain, and axisymmetric +elements-- + +and then, the 3 d elements for +three dimensional and thick + +shell analysis. + +These are continuum elements. + +We call them continuum elements, +because we only use + +u, here u and v, and +here, u v and w-- + +the displacements-- + +to describe the internal +element displacements. + +We're only using the nodal point +displacements u, u v, + +and u v w, for all of the nodal +points to describe the + +internal element +displacements. + +Structure elements, on the +other hand, also use the + +rotations at the nodal point +theta x, theta y, and theta z, + +in order to describe the + +deformations within the element. + +And I will be discussing +structural elements in the + +next lecture, so, for the +moment, we do not have any + +rotations at the nodes. + +Or what we will allow, u v and +w displacements at the nodes. + +Typical examples are given +on this Viewgraph. + +These are elements that are +available in the computer + +program [? Aldena ?]. + +Here we have a truss element, +a two-noded truss element. + +The only displacement of +interest in the truss is the + +actual displacement here. + +Here we have a three-noded +truss, or cable element. + +Here we have a set of two +dimensional elements. + +Notice we have triangular +elements here, a triangular + +element here. + +We have here an eight node +element that is curved. + +We can construct curved +elements in the + +isoparametric approach. + +And here we have a rectangular, +eight node + +element, straight sides, +in other words. + +These elements are used in plane +stress, plane strain, + +and axisymmetric analysis. + +In three dimensional analysis +we might be talking about-- + +we might be using-- + +such elements such as the +eight node brick. + +Each node now has three +displacements, u, v, and w. + +This is here a higher order +element, where we have, in + +addition to the corner nodes, +we also have mid-side nodes. + +You don't need to +have a mid-side + +nodes along all sides. + +For example here, +I did not put a + +mid-side node as an example. + +In fact we could simply have +mid-side nodes here, and no + +mid-side nodes anywhere else. + +I will show you how we +deconstruct these + +interpolation matrices in +the next few minutes. + +Let us consider, as +a very simple + +example, a special case. + +And the special case that I +would like to look at is a + +truss element, which +is two units long. + +In other words, the length from +here to there, is equal + +to 1, and similarly the length +from here to there, is also + +equal to one. + +I'm describing the element with +a coordinate r that I set + +equal to zero at the midpoint +of the element, plus one at + +the right end and minus +one at the left end. + +This is special geometry and +we will later on have to + +generalize our approach to more +general geometries where + +the length is not equal +to two and the element + +might even be curved. + +But for instructive purposes, +let's look at + +this geometry first. + +Similarly, for two dimensional +analysis, I want to look at an + +element that has length two this +direction and length two + +that direction. + +In other words, a generalization +of the concept + +that we just looked +at for the truss. + +Now we have two dimensions and +in each dimension we have a + +length of two. + +I embed into this element +an rs-coordinate system. + +And this coordinate system now +has its origin here at r + +equals zero and s equals zero. + +The r-axis bisects this +side, and the s-axis + +bisects this side. + +Notice that this is a coordinate +system that is + +embedded into the element. + +We also call that the natural +coordinate system, or the + +Isoparametric coordinate +system. + +This element, two by two, would +lie in space in an x + +xy-coordinate system +as indicated here. + +Now for three dimensional +analysis we would proceed in + +the same way, then we would +consider an element that is + +two by two by two +units long into + +each coordinate direction. + +And then we would have an +rs-axis and a t-axis coming + +out of the transparency in +this particular case. + +Well, I want to look at the +truss element, the special + +truss element, and the special +two d element. + +And I want to show you how +we can construct the + +interpolation matrices, the +displacement interpolation + +matrices, h i. + +These are also the coordinate +interpolation matrices. + +I want to show you how we +construct them for the special + +elements, how we then can +calculate the strain + +displacement interpolation +matrices + +for the special elements. + +And then I want to go on and +show you how we generalize to + +concepts to curved elements. + +And once we have discussed the +two dimensional case, I think + +you can see yourself how the +concepts are generalized to + +the three dimensional case. + +Let's look then at our two-noded +truss first. + +Here we have once more, the +truss, and we have node one on + +the right hand side, node two +on the left hand side. + +Our r-coordinate system starts +in the middle of the truss. + +Notice what we want to obtain +is that we interpolate our u + +displacement via the +interpolations. + +U being equal to h i times u i, +the h i are the unknowns. + +I want to show you how +we obtain the h i. + +The u i are the nodal +point displacements. + +In this particular case it would +be here, u two and here + +we would have u one. + +I in other words, goes +from one to two for + +this particular case. + +The h i has to be +a function of r. + +For a given r, however, we can +evaluate the u displacement if + +we have u i is given. + +In other words, when u one and +u two are given, then for a + +given r, we can evaluate +directly from this relation + +the displacement at +that point r. + +Well, with two nodes, we +can only have a bi-- + +only a linear representation +in the displacements. + +The h one, from this relation, +must be this function. + +Because if we look at this, and +we say let u two be equal + +to zero, we would simply +have that u is + +equal to h one u one. + +Well, therefore, our h one must +look this one, because u + +one has its full +strength here. + +If we put u one equal to one, we +would have u is equal to h + +one, and this would +be the variation. + +Similarly, for h two, in this +case, we would have u is equal + +to h two u two. + +H one is now equal to zero. + +If we put you two equal to one, +as I have done in this + +particular case, then our linear +variation is indicated + +as shown here , and +the function h two + +is given right here. + +Notice that h two is equal to +zero when r is equal to one. + +And h two is equal to one when +r is equal to minus 1. + +So, this gives us h two. + +The two-noded truss, therefore, +simply has this + +description here for the +displacement and the + +coordinates. + +Remember that we're using the +same h i for displacement and + +coordinates. + +It simply has this description +where h one and h two are + +defined as shown. + +Let us now say that we want to +add another node, that we want + +to put another node +right there. + +In other words, we want to go +from a two-noded description + +to a three-noded description. + +On one of the earlier +Viewgraphs, you could see a + +three-noded cable element. + +Well, the way we proceed in the +construction of the h i + +functions is as follows. + +The two-noded element simply +had this description here. + +H one is given as shown +here on the left + +side of the blue line. + +H two was simply this. + +And we knew that we could do +no better than a linear + +description in displacements +between two nodes. + +However, now we have a third +node right here. + +And a third node means that +we can use a parabolic + +description in displacements. + +Now h three must be equal to one +at the third node and zero + +at both sides. + +Why? + +Well, because, remember we have +u now equal to h i u I, + +where i equals one to three. + +And if we put u one equal to +zero and u to equal to zero, + +we simply have u equals h three +u three, and, therefore, + +h three is this function. + +I've written it down here when +r is equal to zero its one + +when r is equal to minus 1 +or plus h three is zero. + +So this is our h three. + +However, if we now look back to +our earlier description of + +h one and h two for the +two-noded element, we remember + +that we had a linear +variation here. + +That we had a linear variation +here and here. + +This one was a linear +variation of h one-- + +let me take here the green color +to show once more what + +we are talking about-- + +that was our linear variation. + +And here, this one here was our +linear variation there. + +Well, now with the third node +there, we recognize that, at + +this third node our h two-- + +our actual h two for the +three-noded truss-- + +must be zero here. + +H one must be zero here. + +Well, how can we make +it zero here? + +We can make it zero by +subtracting from our two-noded + +truss h one, one half of this +parabolic description. + +And that's what I +have done here. + +Similarly, we have to subtract +it here, because then, what we + +are doing is we are taking one +half off this parabola, and we + +are putting it right on here. + +This is one half of the +bottom parabola. + +We are putting it on there. + +And that brings this point +back to that point. + +Remember this is equal to one. + +I want one half as a correction +here, and that's + +why I take one half of one minus +r squared, to bring this + +point back to there. + +This total description then, +this total part-- + +this part here, all +of that together-- + +is our h one for the three-noded +element, for the + +three-noded element. + +And similarly, we would +have four h two. + +This total part here is this +function here for our + +three-noded element. + +Now the important point that +I really would like you to + +understand is that, we have +started off with a two-noded + +element description-- + +h one only the linear part, h +two only the linear part. + +We have constructed the +interpolation function for the + +third node, and then we have +corrected the earlier + +two-noded interpolation +functions via subtracting a + +certain part of the third +interpolation function, in + +order to obtain the new +h one and h two for + +the three-noded element. + +And this is indeed the actual +procedure that we can use very + +effectively in constructing +higher order elements. + +We are starting off with +the lower order element + +descriptions-- + +the ones shown here dashed with +a dashed line, the linear + +part only-- + +and we add in the higher order +description, and subtract the + +correction from the lower +order description. + +The correction has to be +subtracted to bring this point + +back to zero, because h one +total must now be equal to + +zero here, h two total must be +equal to zero here, and this + +way we have constructed our new +h one and h two for the + +three-noded truss element. + +Let's look at the four-noded +element in two dimensions now. + +Here we use very similar +concepts. + +These are the four nodes +for the element. + +The description along a side +is just like we have been + +discussing now for the truss, +linear here and linear here. + +Notice h one can directly +be written down. + +It has to be equal to one here +and zero everywhere else. + +This is a function which is +bilinear and which satisfies + +these conditions to be equal +to one here and. + +Zero at the other nodes. + +It is a linear variation along +this side, along this side, + +and also across the surface. + +In other words, for a given +value of r, we have a linear + +variation across here too. + +How do we obtain h two? + +Well, we simply have to change +the signs over here-- + +the plus signs here-- in +an appropriate way. + +H two shall be equal to one +here zero at all the other + +nodes, while we see that this +function satisfies these + +conditions, let's put in +r equal to minus 1. + +That makes this two, divided +by four, gives us one half. + +S has to be equal to plus +1 at this point-- + +you get another two in here-- + +so h two is equal to one +right there, and its + +zero everywhere else. + +Similarly we construct +h three and h four. + +Indeed we can immediately +observe that these signs-- + +plus in both cases here, a minus +here, plus there, minus, + +minus, plus, minus-- these signs +correspond to nothing + +else in the signs of the r- and +s-coordinates of the nodal + +point under consideration. + +R and s is plus here, you have +two plus signs here. + +R is negative here, you put +a negative sign here. + +But s is positive here, you +put a plus sign there. + +r and s both are negative here, +so we have two negative + +signs here, et cetera. + +Let us now see how we construct +from this basic four + +node element, which really +corresponds to our basic two + +node element in the case of +the truss, how we can + +construct higher +order elements. + +Well, we proceed in much the +same way as in the truss + +formulation. + +Here we have a four-noded basic +element and we have + +added a fifth node to it. + +Now let's look at +this in detail. + +Since we now have added a fifth +node here, we know that + +we can allow a parabolic +distribution. + +In fact, we should allow a +parabolic distribution of + +displacements along the side. + +Well, if its a parabola along +the side for s being plus 1, + +we immediately see that +this function here-- + +this s equal to plus one, this +is equal to two, knocks out + +that one half, we have +a one minus r + +squared along the side-- + +just the same function that we +already had in the truss. + +Well, along this direction we +can only vary things linearly + +because we have two nodes only +in along these directions. + +And this is the reason +why we have to put in + +a one plus s here. + +The linear variation is +given by one plus s. + +And we also notice that when s +is equal to minus 1, in other + +words, we are looking at this +side, this function is zero. + +When s is equal to plus one, +as we pointed out earlier, + +this function here-- + +this part and that part-- + +gives us a one together, and we +have simply a one minus r + +squared along here. + +So, here you can see these +triangles that show the linear + +variation along this side. + +These parabolas here run really +across here, but with a + +different intensity. + +The intensity off the parabola +goes down linearly from one at + +this end, to is zero +at that end. + +This is our h five. + +Well, if we have this as our h +five, we remember that our + +original h one of the of the +four-noded element had a + +linear variation along here, +and also a linear variation + +along here. + +We will now have to take this +h one and subtract some + +correction from it. + +In order to make this point here +have zero displacement, + +four h one. + +Well, what we will do is we take +this h five and subtract + +a multiple of h five +from h one. + +In fact, you can see since the +original h one is equal to one + +half here, we simply have to +subtract one half of this + +function to obtain +the new h one. + +And this is what I have done +on this Viewgraph. + +The h one now is the original +h one that we had. + +And we are subtracting one half +of h five, which is one + +half of the parabolic +distribution, to bring this + +point here down to zero +in displacements. + +And that's what we +have done here. + +The resulting function +then is shown here. + +And our h one for the five-noded +element is shown + +right here. + +Similarly, for h two-- + +this is the h two function for +the five-noded element-- + +interesting to note that h three +and h four are for the + +five-noded element, the same as +for the four-noded element. + +Because this fifth node lies +between nodes one and two. + +And there is no effect +along this side and + +along this side here-- + +along that side four h three and +h four-- so, we have our + +original functions also for +the five-noded element. + +Let us look now at a + +generalization of this concept. + +Here we have a typical +nine-noded element. + +A very effective element for +many types of applications. + +I already show it here in its +curved form, but think of it, + +please, as follows. + +This is the x-axis. + +This is the r-axis. + +S is equal to zero +along this side. + +S is equal to plus one +along this side. + +S is equal to minus +1 along this side. + +R is equal to plus one +along this side. + +R is equal to minus one +along the side. + +And r is zero along this axis. + +So, in the r s description, +in the embedded coordinate + +system, this element is still a +two by two squared element. + +Well, if we look then at the +interpolation functions, for + +this element, they +look as follows. + +Now maybe you have difficulty +seeing all this information, + +so, please then refer to the +study guide where you'll find + +this Viewgraph. + +For the four-noded element, +we had these + +interpolation functions. + +If we want to deal with the +five-noded element, what we + +have to do is, we add this +interpolation function. + +And-- + +as I pointed out earlier-- + +we have to correct our +h one and h two. + +But that is all of the +correction that is required. + +H three and h four +not corrected-- + +they are blank spots here, they +are blank spots here. + +So, our five-noded element would +have these interpolation + +functions now shown in red. + +For if we added a sixth node-- + +and I now should go back to +our earlier picture-- + +if I wanted to add, in addition +to the fifth node, + +also the sixth node. + +Well, then, I have to put +another interpolation function + +down here, which now +is parabolic in s + +and linear in r. + +And I have to correct h two and +h three again, these are + +the corrections. + +So, now I have in green here +shown to you the interpolation + +functions off a six-noded +element. + +And like that we can proceed +by adding interpolation + +functions and correcting +the earlier constructed + +interpolation functions +as shown. + +Like that we can proceed +to directly obtain the + +interpolation functions for +the five-noded, six-noded, + +seven-, eight-, and nine-noded +element. + +In fact, its also important to +notice that we could have this + +node, that node, this node, and +that node, and just h nine + +also added. + +We could have, in other words, +a five-noded element which + +looks like this. + +It has this node, that one, that +one, and that one, and + +that one in the middle. + +Another five-noded element would +be this one, this one, + +this one, this one with +that node in there. + +So there is no necessity in +having all the nodes below a + +certain number. + +But we can simply use four +nodes, and then add whichever + +nodes we want to have +into the element. + +This is, then, how we construct + +interpolation functions. + +And once we had the h i, we +directly can obtain the h + +matrix, the matrix that gives +the displacements in terms of + +the nodal point displacements. + +Notice that the h +matrix really is + +constructed from the hi's. + +And the elements of +the b matrix-- + +the strain displacement +interpolation matrix-- + +are the derivatives of +the h i or zero. + +And I will show you an +example right now. + +Because we are using four, we +are still looking at the + +special case of a two by two +by two element in a truss + +case, only this two. + +Plane stress, plane strain, +axisymmetry, two dimensional + +analysis, we have +these two two's. + +In other words, we're talking +about a two by two element. + +And in three dimensional +analysis we would talk about a + +two by two by two element. + +In these cases, we have x equal +to r, y equal to s, z + +equal to t. + +So the strains-- + +which are derivatives with +respect to x the actual + +physical coordinates-- + +can also directly be obtained +by simply taking the + +derivative with respect +to r, and then + +similarly for s and t. + +Let us look at a four node, +two dimensional element. + +This is really the element +that we have used in our + +earlier example of the +cantilever analysis. + +Here we would simply have +that u r s, v r s, are + +described as shown. + +Notice that in the first row we +are really saying nothing + +else than u is a summation +h i u i. + +Where i equals one to +four because we have + +a four-noded element. + +H i u i. + +In the second row we are really +saying nothing else + +than v being the summation of i +equals one to four h i v i. + +And all I have done is I have +taken these hi's and assembled + +them into a matrix form to +obtain our h matrix. + +This h matrix here-- + +the entries in that h matrix-- +are dependent on the ordering + +that you're using here for u +one, v one, u two, et cetera. + +With this ordering, these +are the entries. + +Notice there are zeroes here, +because the v degrees of + +freedom at the nodes have +no contribution to the u + +displacement in the element. + +Well, if we look at the plane +stress case and want to + +construct our b matrix, remember +the b matrix gives + +the strains in terms of the +nodal point displacements. + +And we remember also that our +epsilon xx is equal to a dy + +dx, our epsilon yy is equal to +dv dy and our gamma xy is + +equal to a du dy plus dv dx. + +Well, if we recognize +these facts. + +And we also note again that for +the two by two element, r + +is identical to x, s +is identical to y. + +Then, we can obtain the epsilon +rr or epsilon xx by + +simply taking the derivatives of +the hi's with respect to r. + +Notice here, since u is equal +to the summation of h i u i, + +dy dr, which is equal to du dx, +is nothing else then the + +summation of partial +h i dr u i. + +And this part, which runs +from one to four-- + +i going from one to four-- + +I simply put right in there. + +I proceed similarly +for epsilon yy. + +Now I'm talking about the v +displacements, which are + +stored after the u +displacements. + +That's why I'm looking +here at the second + +column, the last column. + +And here we have dh one ds, +because we are talking about + +the derivative with respect to +y or with respect to s, which + +is the same thing. + +So here we have the entries +for the epsilon ss part. + +Now for the strain part, we are +talking du dy or du ds, dv + +dx, dv dr. And all we have to +do in now is take this term + +and put it right in there, and +take this term and put it + +right in there. + +And then the last row +here gives us + +the shearing strength. + +So this is our b matrix for the + +special two by two element. + +It is constructed in +a very simple way. + +The h i are known, and if we +had five or six or seven + +nodes, we would proceed in +exactly the same way. + +All we would have to do is +include additional columns in + +the b matrix that would give us +the appropriate entries for + +strains generated by the +additional nodal point + +displacements. + +Let us now look how we can +generalize these concepts to + +the element that is not, +anymore, in the physical x and + +y space, two by two element. + +In the physical x and y +space, this element-- + +four-noded element now-- + +might look as shown here. + +However, what we do is we still +deal with the r- and + +s-coordinate system embedded +on the element. + +We are on s one here, minus one +s plus one here, r and s + +both minus one here, plus +one here s minus one. + +So in the natural coordinate +space, the rs space, we still + +have a two by two element. + +The interpolation of the +displacement therefore-- + +the interpolation of +the displacements-- + +even for the distorted element, +is exactly still as + +shown here. + +Provided we are entering +always with the + +appropriate r and s. + +H one is a function +of r and s. + +So if we look at a point in +the general element, if we + +look at a point in the general +element, here, for example, at + +such a point. + +Because that point has a +specific r and s value. + +And if we want to find the +displacement at that point, + +well, we would have to put the +r and s value of that point + +into h one, h two, h three, h +four, and that gives us then + +the displacement at that point, +in terms of the nodal + +point displacement. + +So, the displacement +interpolation for this element + +can still be done in +the r and s space. + +However, difficulties arise-- + +or additional considerations +I should say rather-- + +arise when we talk about +strains, because the physical + +strains that we have to deal +with are derivatives with + +respect to x and y, and +not r and s anymore. + +Well, so what we have to +do is, use a Jacobian + +Transformation. + +What we want are the +derivatives with + +respect to x and y. + +What we can find easily are +derivatives with respect to r + +and s on the displacements, +because the displacements are + +given in terms of +r and s values. + +So, remember u is equal to some +of h i u i and the h i is + +a function of r and s, so, we +can directly find derivatives + +with respect to r and s of u. + +What we cannot find easily are +derivatives with respect to x. + +This is the relationship +that we use. + +It gives us a transformation +from derivatives of x and y to + +derivatives r and s. + +A question must immediately be +in your mind, why do we not + +write down directly this +relationship, which is given + +by the [INAUDIBLE]. + +If we want d dx of +displacements, why not just + +use d dx being equal to d +dr, dr dx, and so on. + +Well, the difficultly +is that we cannot + +find dr dx very easily. + +We have x being this function +of h i x i. + +This is the interpolation which +we have to use now. + +I mentioned earlier on the +first slide that we + +interpolate displacement and +coordinates in the same way. + +So, here we have a linear +interpolation of the + +coordinates, from this node +to that node, and in + +between here too. + +So we are using this +interpolation here on the + +coordinates. + +And we can easily dx dr, but we +cannot easily find dr dx. + +You would have to invert this +relationship somehow so that + +we have r in terms of x. + +Well, it is easier, therefore, +to write this relationship + +down, which is really +the chain rule. + +This is also the chain rule, its +a chain rule the other way + +around, which gives d dr being +equal to d dx, dx dr plus d dy + +dy dr, if we multiply +this out. + +And its this relationship that +we can use effectively. + +Well, this relationship in three +dimensional analysis + +would involve a third row +and third column. + +In one dimensional analysis we +only talk about one by one. + +In other words, in one dimension +analysis for a truss + +we just have that entry. + +In general we can write it in +this way, where j is the + +Jacobian transformation from the +xyz-coordinate system to + +the rst-coordinate system. + +And since we want these +derivative-- + +because these derivatives give +us actual strains, we have to + +invert this relationship. + +Having constructed then, these +derivatives in terms of these + +derivatives, which we can find +just as we have done before, + +we can now establish the +b matrix in much + +the same way as earlier. + +And since we now have h and b +matrices for an element-- + +these are a function +r, s, and t-- + +we would perform the +integration. + +And now I'm referring to +the integration of + +the stiffness matrix. + +Remember k is equal to b, +transposed cb over the volume. + +Now notice that since the b +matrix that we are using in + +here is a function of r and s in +a two dimensional analysis. + +And r runs from minus one to +plus one, and s runs from + +minus one to plus one. + +We now have to use a +transformation also on dv to + +integrate over the r s volume. + +And that integration-- + +and that dv element is expressed +as shown here-- + +and that is given to us from +mathematical analysis. + +So basically what we are saying +here is that we are + +replacing this integral over +the physical volume by an + +integral minus one to plus one, +minus one to plus one. + +And that signifies from minus +one to plus one over r and + +over s, if we had a three +dimensional analysis we would + +have another integral +sign here. + +B transposed now r and s +function of r and s, cb, + +function of r and s. + +And then our dv, now in +terms of r and s. + +So this is how we really +do things. + +And remember this dv here, this +dv, is that one there. + +This integration is effectively +performed using + +numerical integration and +I will discuss later on. + +Let's look once at the Jacobian +transformation for + +some very simple examples-- + +the Jacobian transformation for + +some very simple examples-- + +just to make things +a little clearer. + +In this case we really have +taken our two by two element + +and we have stretched it +into the x- and y-axes. + +That stretching is giving us a +three here and a two there + +because our two by two element +has a length of two here, and + +six divided by two +gives us three. + +Similarly here we have stretched +the element by a + +factor of two. + +This relationship here is, +in general, calculated-- + +the j is, in general, +calculated-- + +as shown here. + +And the result of that, by +putting these interpolations + +into there are these +values here. + +Physically what these mean +is a stretching, in this + +particular case, into +the x- and y-axis. + +Somewhat-- + +the case where we cannot +directly-- + +not easily directly write down +to j matrix is this one. + +Here we would go through the +actual evaluation the way I + +have indicated it. + +In other words, we would +go through this actual + +evaluation, substituting from +here and of course for y also. + +And this would be the result +Notice that we now have a + +stretching here of three, +compression from a two length + +to a one length-- + +therefore we have a one half +here-- and there's also an + +angle change that gives us the +off-diagonal element here. + +Another interesting case here, +as an example, we have the + +same lengths here-- + +two same lengths here-- but a +distortion in the element + +because this node two +has come down from + +there to its midpoint. + +And the resulting Jacobian +is given here. + +Now notice that that Jacobian is +a function r and s, so the + +inverse, which is used in the +construction of the b matrix + +would also be a function +of r and s. + +A particularly interesting case +is the one where we shift + +nodes to advantage. + +See here we have +our original-- + +our three-noded element that we +talked about already-- in + +the r space now. + +Its a truss element. + +And let's say that in our actual +physical space, we have + +this node there, the three +node there, and + +the two node there. + +The element in the actual +physical space + +has a length of l. + +We have taken this node and +shifted it to the quarter + +point of the element, to the +quarter point of the element. + +What I will show you right now +is that by having done so-- by + +having taken this node from its +midpoint and shift it over + +in the actual physical space +to the quarter point-- + +we will find that the strain has +a singularity here of one + +over square root x. + +This is a very important point +which can be used in the + +analysis of fracture problems, +because we know that in the + +analysis of fracture problems, +we have a one over square root + +x singularity at a crack tip. + +And, if we want to predict the +actual stress there or the + +displacement around the crack +tip, it can be of advantage to + +use this fact, shifting nodes to +quarter points in order to + +capture the stress singularity +more accurately. + +Well let me show you then how +this strain or stress + +singularity comes about. + +If we look at this element +here and we use our + +interpolation on the +coordinates, this + +would be the result. + +Now, notice that we +have substituted + +the x i values here. + +X one is zero, x two is l, +x three is l over four. + +We have substituted those values +and directly come up + +with this result. + +Well, we can see that +this indeed is true. + +Let's put r equal +to plus one n. + +In other words, the right +hand side node-- + +for the right hand side node-- +and we would have a two here + +squared, gives us four, goes +out with that four. + +So at i equals plus 1 we have +x equal to l, which + +is correct of course. + +Let's put i equal to minus one +n, we find x is equal to zero. + +Let's put i equal to +zero n we find x is + +equal to l over four. + +In other words, this has been a +simple check in that we have + +the right interpolation-- + +geometry interpolation-- + +for this element. + +Our j now is simply, dx +dr, X is given here. + +If you take the differentiation +of that you + +get the two in front that gives +l over two times one + +plus r, this value here, +in other words. + +Then our b matrix is +constructed by the + +inverse of the j-- + +that is this one-- + +two times the r derivative of +the interpolation functions. + +Of course here we talk only +about one strain. + +Remember, in the truss, the only +displacement of concern + +is the u displacement and the +strain is simply epsilon xx, a + +strain into this +direction also. + +Well, this is our +b matrix then. + +And if we take our h one, +two, and three, and we + +differentiate these-- + +as indicated here with respect +to r-- we directly obtain + +these functions here. + +If we now recognize that since +we have x related to r here, + +we can also invert this +relationship. + +We can write r in terms of x. + +And if we have done so we can +take that relationship and put + +it right in here. + +Then we would get +b in terms of x. + +And that's what I +have done here. + +The first line shows simply r in +terms of x now, and I have + +substituted that r value into +the b matrix and this is there + +is the result. + +Notice that we have a +strain singularity. + +This is the first +element here. + +The next element-- + +this is here-- + +the next element in b matrix, +and that is the third element + +in the b matrix. + +Notice that we have in this +element, that one, and that + +one the one over square root +x, which means that we have + +one over square root +x singularity + +at x equal to zero. + +Well, this fact is used very +effectively in fracture + +mechanics analysis. + +Assume that we have crack here +and that we want to analyze + +the stress conditions +around that crack. + +What we can do is we use now two +dimension elements, as its + +a plane stress situation. + +We would put a two dimensional +triangular element there and + +we shift the midpoint nodes. + +This is now very small +here, but I hope + +you can still follow. + +You shift these midpoint nodes +to the quarter point, just the + +way we have been +doing it here. + +You are putting the third node +the quarter point and the + +result is that at this crack tip +we have a one over square + +root x singularity, using +this element layout. + +And we know that in fact, there +is a one over square + +root x singularity in linear +fracture mechanics analysis. + +And so this is an effective +way of capturing this + +singularity, and has been used +or is currently being used + +very abundantly in practice. + +The important point that I +wanted to make really is that + +we can shift nodes in the +element to our advantage. + +But, we really do that in +specific applications such as + +fracture mechanics. + +In general we will see later +when I talk about modeling of + +finite element systems, in +general, it is most effective + +to leave the mid-side nodes at +their physical midpoints. + +In other words for an +eight-noded element, two + +dimensional analysis, we would +put this mid-node in the + +physical space also, actually +at the midpoint. + +We would not shift it. + +Then the element has good +convergence characteristics + +into all directions and this is +really how the element is + +used most effectively for +general applications. + +However, in specific +applications, such as fracture + +mechanics analysis, it can be +of advantage to shift these + +mid-side nodes to pick up +certain strain or stress + +singularities that +we know do exist. + +Now on the last transparency +that I wanted to show you, I + +wanted to indicate something to +you that I will be talking + +about in later lectures more +abundantly, namely the fact + +that we're using numerical +integration. + +B, for the k matrix as an +example, is once again now a + +function of r and s. + +This part here is also a +function of r and s. + +So we have here function +of r and s. + +and we have here also a +function of r and s. + +So this f matrix here is +a function of r and s. + +Notice that the b also includes +the inversion of the + +j, the Jacobian matrix. + +It includes the inversion of +the j, because we had to + +construct the x and y and z +derivatives from the r, s, and + +t derivatives. + +So, what we do in practical +analysis is that we use + +numerical integration to +evaluate the k matrix. + +I have indicated that here +schematically, if you look at + +this element here. + +What we do is, we evaluate the +f matrix-- this is a matrix. + +In two dimensional analysis we +would only run over i and j. + +I is this direction. + +J is that direction. + +In three dimensional analysis, +which is in general analysis, + +we run i, j, and k this way. + +We evaluate the f matrix +here at specific + +points, r, s, and t. + +T now being this axis. + +And then multiply that f matrix +by certain weight + +constants and sum these +contributions over all i, j, + +and k, in order to obtain an +accurate enough approximation + +to the actual stiffness +matrix. + +The order of approximation +with which we obtain the + +actual stiffness matrix-- + +or rather how closely the +numerically calculated + +stiffness matrix approximates +the actual stiffness matrix-- + +depends on, number one, how many +integration points we are + +using and what kind +of integration + +scheme we are using. + +These points here correspond +to the Gauss numerical + +integration. + +In this case for two dimensional +analysis, we would + +use a two by two integration. + +In other words, i and j would +both run from one to two. + +K is not applicable and we would +have altogether four + +evaluations off the Fs here. + +Multiply each of them by +weighting factors, which has + +been derived for us by Gauss +some long time ago. + +And summing up these +contributions gives us a close + +enough approximation +to the k matrix. + +Of course, the question of how +many points we have to use, + +what integration scheme we +should use, is a very + +important one. + +We must use enough integration +points to get a close enough + +approximation to the actual +stiffness matrix and I will be + +addressing those questions +in a later lecture. + +This is all I wanted to +say in this lecture. + +Thank you very much for +your attention. \ No newline at end of file diff --git a/E58_lRznkDg.txt b/E58_lRznkDg.txt new file mode 100644 index 0000000000000000000000000000000000000000..200bf78768ca2993a697f3ec68d9937d92db80d3 --- /dev/null +++ b/E58_lRznkDg.txt @@ -0,0 +1,8547 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu we're going to do the first + + align:start position:0% +ocw.mit.edu we're going to do the first + + + align:start position:0% +ocw.mit.edu we're going to do the first +of three lectures on the last topic + + align:start position:0% +of three lectures on the last topic + + + align:start position:0% +of three lectures on the last topic +we're going to talk about phase diagram + + align:start position:0% +we're going to talk about phase diagram + + + align:start position:0% +we're going to talk about phase diagram +starting today Monday and wrap it up on + + align:start position:0% +starting today Monday and wrap it up on + + + align:start position:0% +starting today Monday and wrap it up on +Wednesday + + align:start position:0% +Wednesday + + + align:start position:0% +Wednesday +um phase diagrams is related to the + + align:start position:0% +um phase diagrams is related to the + + + align:start position:0% +um phase diagrams is related to the +question of stability and sustaining the + + align:start position:0% +question of stability and sustaining the + + + align:start position:0% +question of stability and sustaining the +solid state and we've talked about the + + align:start position:0% +solid state and we've talked about the + + + align:start position:0% +solid state and we've talked about the +behavior of solids and we've used solids + + align:start position:0% +behavior of solids and we've used solids + + + align:start position:0% +behavior of solids and we've used solids +in order to teach the rudiments of + + align:start position:0% +in order to teach the rudiments of + + + align:start position:0% +in order to teach the rudiments of +chemistry but today I want to talk about + + align:start position:0% +chemistry but today I want to talk about + + + align:start position:0% +chemistry but today I want to talk about +the conditions under which solids are + + align:start position:0% +the conditions under which solids are + + + align:start position:0% +the conditions under which solids are +stable and uh what under what conditions + + align:start position:0% +stable and uh what under what conditions + + + align:start position:0% +stable and uh what under what conditions +do solids uh remain stable when they + + align:start position:0% +do solids uh remain stable when they + + + align:start position:0% +do solids uh remain stable when they +become unstable this important in + + align:start position:0% +become unstable this important in + + + align:start position:0% +become unstable this important in +industry for example if you're running a + + align:start position:0% +industry for example if you're running a + + + align:start position:0% +industry for example if you're running a +cast chop you're making Auto Parts you + + align:start position:0% +cast chop you're making Auto Parts you + + + align:start position:0% +cast chop you're making Auto Parts you +want to know what the solidification + + align:start position:0% +want to know what the solidification + + + align:start position:0% +want to know what the solidification +temperature is of a particular alloy + + align:start position:0% +temperature is of a particular alloy + + + align:start position:0% +temperature is of a particular alloy +it's important in failure analysis + + align:start position:0% +it's important in failure analysis + + + align:start position:0% +it's important in failure analysis +something like U the fall of the World + + align:start position:0% +something like U the fall of the World + + + align:start position:0% +something like U the fall of the World +Trade Center looking at the metal + + align:start position:0% +Trade Center looking at the metal + + + align:start position:0% +Trade Center looking at the metal +specimens to determine what was the mode + + align:start position:0% +specimens to determine what was the mode + + + align:start position:0% +specimens to determine what was the mode +of failure the temperature excursions + + align:start position:0% +of failure the temperature excursions + + + align:start position:0% +of failure the temperature excursions +leave a signature a thermal signature + + align:start position:0% +leave a signature a thermal signature + + + align:start position:0% +leave a signature a thermal signature +indicative of the history of what + + align:start position:0% +indicative of the history of what + + + align:start position:0% +indicative of the history of what +happened to that object and by + + align:start position:0% +happened to that object and by + + + align:start position:0% +happened to that object and by +determining whether something went above + + align:start position:0% +determining whether something went above + + + align:start position:0% +determining whether something went above +a certain phase transformation + + align:start position:0% +a certain phase transformation + + + align:start position:0% +a certain phase transformation +temperature we can retrace reconstruct + + align:start position:0% +temperature we can retrace reconstruct + + + align:start position:0% +temperature we can retrace reconstruct +the uh the + + align:start position:0% +the uh the + + + align:start position:0% +the uh the +incident you might say well gee what's + + align:start position:0% +incident you might say well gee what's + + + align:start position:0% +incident you might say well gee what's +the big deal I mean you you look on + + align:start position:0% +the big deal I mean you you look on + + + align:start position:0% +the big deal I mean you you look on +the look up in the tables everybody + + align:start position:0% +the look up in the tables everybody + + + align:start position:0% +the look up in the tables everybody +knows that water boils at 100° + + align:start position:0% +knows that water boils at 100° + + + align:start position:0% +knows that water boils at 100° +Centigrade but maybe it's not so simple + + align:start position:0% +Centigrade but maybe it's not so simple + + + align:start position:0% +Centigrade but maybe it's not so simple +let's say you decide to realize your + + align:start position:0% +let's say you decide to realize your + + + align:start position:0% +let's say you decide to realize your +life's Ambitions and you're going to go + + align:start position:0% +life's Ambitions and you're going to go + + + align:start position:0% +life's Ambitions and you're going to go +climb Mount Everest so you plop down + + align:start position:0% +climb Mount Everest so you plop down + + + align:start position:0% +climb Mount Everest so you plop down +$10,000 you get a permit from the napes + + align:start position:0% +$10,000 you get a permit from the napes + + + align:start position:0% +$10,000 you get a permit from the napes +government the next thing you know + + align:start position:0% +government the next thing you know + + + align:start position:0% +government the next thing you know +you're at base camp 20,000 ft you have a + + align:start position:0% +you're at base camp 20,000 ft you have a + + + align:start position:0% +you're at base camp 20,000 ft you have a +hankering for soft Bo boiled egg so you + + align:start position:0% +hankering for soft Bo boiled egg so you + + + align:start position:0% +hankering for soft Bo boiled egg so you +pitch of campfire put in the + + align:start position:0% +pitch of campfire put in the + + + align:start position:0% +pitch of campfire put in the +eggs 5 minutes 10 minutes 15 minutes + + align:start position:0% +eggs 5 minutes 10 minutes 15 minutes + + + align:start position:0% +eggs 5 minutes 10 minutes 15 minutes +pardon me you want hard boiled eggs you + + align:start position:0% +pardon me you want hard boiled eggs you + + + align:start position:0% +pardon me you want hard boiled eggs you +want hardboiled eggs after 15 minutes + + align:start position:0% +want hardboiled eggs after 15 minutes + + + align:start position:0% +want hardboiled eggs after 15 minutes +you open the eggs they're still + + align:start position:0% +you open the eggs they're still + + + align:start position:0% +you open the eggs they're still +running you get really steamed you 20 + + align:start position:0% +running you get really steamed you 20 + + + align:start position:0% +running you get really steamed you 20 +minutes 25 minutes every time the Yol is + + align:start position:0% +minutes 25 minutes every time the Yol is + + + align:start position:0% +minutes 25 minutes every time the Yol is +still running the white is converted but + + align:start position:0% +still running the white is converted but + + + align:start position:0% +still running the white is converted but +the yolk is still running what's going + + align:start position:0% +the yolk is still running what's going + + + align:start position:0% +the yolk is still running what's going +on well we talked about denaturing the + + align:start position:0% +on well we talked about denaturing the + + + align:start position:0% +on well we talked about denaturing the +white denatures at 65° + + align:start position:0% +white denatures at 65° + + + align:start position:0% +white denatures at 65° +Centigrade but + + align:start position:0% +Centigrade but + + + align:start position:0% +Centigrade but +at 20,000 ft the atmospheric pressure is + + align:start position:0% +at 20,000 ft the atmospheric pressure is + + + align:start position:0% +at 20,000 ft the atmospheric pressure is +reduced to the point that water boils at + + align:start position:0% +reduced to the point that water boils at + + + align:start position:0% +reduced to the point that water boils at +below the denaturing temperature of the + + align:start position:0% +below the denaturing temperature of the + + + align:start position:0% +below the denaturing temperature of the +egg yolk and so you can boil until the + + align:start position:0% +egg yolk and so you can boil until the + + + align:start position:0% +egg yolk and so you can boil until the +end of time and you'll always have + + align:start position:0% +end of time and you'll always have + + + align:start position:0% +end of time and you'll always have +softboiled eggs if you like softboiled + + align:start position:0% +softboiled eggs if you like softboiled + + + align:start position:0% +softboiled eggs if you like softboiled +eggs you cannot screw up you cannot + + align:start position:0% +eggs you cannot screw up you cannot + + + align:start position:0% +eggs you cannot screw up you cannot +screw up okay so what do we know from + + align:start position:0% +screw up okay so what do we know from + + + align:start position:0% +screw up okay so what do we know from +this little anecdote this little + + align:start position:0% +this little anecdote this little + + + align:start position:0% +this little anecdote this little +anecdote is that the boiling point the + + align:start position:0% +anecdote is that the boiling point the + + + align:start position:0% +anecdote is that the boiling point the +boiling point is a function of pressure + + align:start position:0% +boiling point is a function of pressure + + + align:start position:0% +boiling point is a function of pressure +so it's not that simple let's go to + + align:start position:0% +so it's not that simple let's go to + + + align:start position:0% +so it's not that simple let's go to +another place let's go uh let's go under + + align:start position:0% +another place let's go uh let's go under + + + align:start position:0% +another place let's go uh let's go under +the hood of a car one my favorite places + + align:start position:0% +the hood of a car one my favorite places + + + align:start position:0% +the hood of a car one my favorite places +okay so here's what's going on under the + + align:start position:0% +okay so here's what's going on under the + + + align:start position:0% +okay so here's what's going on under the +hood of a car here you've got the + + align:start position:0% +hood of a car here you've got the + + + align:start position:0% +hood of a car here you've got the +engine and inside the engine we have + + align:start position:0% +engine and inside the engine we have + + + align:start position:0% +engine and inside the engine we have +combustion and the combustion gives off + + align:start position:0% +combustion and the combustion gives off + + + align:start position:0% +combustion and the combustion gives off +a huge amount of heat we have to + + align:start position:0% +a huge amount of heat we have to + + + align:start position:0% +a huge amount of heat we have to +dissipate that heat so we have water + + align:start position:0% +dissipate that heat so we have water + + + align:start position:0% +dissipate that heat so we have water +channels running through the engine and + + align:start position:0% +channels running through the engine and + + + align:start position:0% +channels running through the engine and +out to the radiator and the radiator + + align:start position:0% +out to the radiator and the radiator + + + align:start position:0% +out to the radiator and the radiator +cools this water before recirculating it + + align:start position:0% +cools this water before recirculating it + + + align:start position:0% +cools this water before recirculating it +thanks to the action of either fand or + + align:start position:0% +thanks to the action of either fand or + + + align:start position:0% +thanks to the action of either fand or +wind or some kind of movement of + + align:start position:0% +wind or some kind of movement of + + + align:start position:0% +wind or some kind of movement of +air and so what's the principle here the + + align:start position:0% +air and so what's the principle here the + + + align:start position:0% +air and so what's the principle here the +principle here is that inside the + + align:start position:0% +principle here is that inside the + + + align:start position:0% +principle here is that inside the +radiator we've got solid this is the the + + align:start position:0% +radiator we've got solid this is the the + + + align:start position:0% +radiator we've got solid this is the the +rad it's probably made of uh the old + + align:start position:0% +rad it's probably made of uh the old + + + align:start position:0% +rad it's probably made of uh the old +days they made them out of copper but + + align:start position:0% +days they made them out of copper but + + + align:start position:0% +days they made them out of copper but +nowadays they're making more and more of + + align:start position:0% +nowadays they're making more and more of + + + align:start position:0% +nowadays they're making more and more of +them out of aluminum and we have liquid + + align:start position:0% +them out of aluminum and we have liquid + + + align:start position:0% +them out of aluminum and we have liquid +which is the coolant this is the coolant + + align:start position:0% +which is the coolant this is the coolant + + + align:start position:0% +which is the coolant this is the coolant +this is + + align:start position:0% +this is + + + align:start position:0% +this is +water and we have a big delta T here + + align:start position:0% +water and we have a big delta T here + + + align:start position:0% +water and we have a big delta T here +right this is hot this is cool and so we + + align:start position:0% +right this is hot this is cool and so we + + + align:start position:0% +right this is hot this is cool and so we +have a heat flux going in this direction + + align:start position:0% +have a heat flux going in this direction + + + align:start position:0% +have a heat flux going in this direction +and this is working great because the + + align:start position:0% +and this is working great because the + + + align:start position:0% +and this is working great because the +density of water is high and so + + align:start position:0% +density of water is high and so + + + align:start position:0% +density of water is high and so +therefore it's able to transfer heat + + align:start position:0% +therefore it's able to transfer heat + + + align:start position:0% +therefore it's able to transfer heat +very efficiently so this is good this is + + align:start position:0% +very efficiently so this is good this is + + + align:start position:0% +very efficiently so this is good this is +really good what can happen if things go + + align:start position:0% +really good what can happen if things go + + + align:start position:0% +really good what can happen if things go +out of control things go out of control + + align:start position:0% +out of control things go out of control + + + align:start position:0% +out of control things go out of control +and we start to boil and you know that + + align:start position:0% +and we start to boil and you know that + + + align:start position:0% +and we start to boil and you know that +the boiling point of water is more or + + align:start position:0% +the boiling point of water is more or + + + align:start position:0% +the boiling point of water is more or +less 100° Centigrade we're down here + + align:start position:0% +less 100° Centigrade we're down here + + + align:start position:0% +less 100° Centigrade we're down here +we're not at the base camp in Mount + + align:start position:0% +we're not at the base camp in Mount + + + align:start position:0% +we're not at the base camp in Mount +Everest here's what happens when things + + align:start position:0% +Everest here's what happens when things + + + align:start position:0% +Everest here's what happens when things +start to go out of control now we start + + align:start position:0% +start to go out of control now we start + + + align:start position:0% +start to go out of control now we start +to get + + align:start position:0% +to get + + + align:start position:0% +to get +gas bubbles these are the gas bubbles + + align:start position:0% +gas bubbles these are the gas bubbles + + + align:start position:0% +gas bubbles these are the gas bubbles +associated with the boiling of water and + + align:start position:0% +associated with the boiling of water and + + + align:start position:0% +associated with the boiling of water and +now the heat transfer between gas and + + align:start position:0% +now the heat transfer between gas and + + + align:start position:0% +now the heat transfer between gas and +solid between gas and solid is very poor + + align:start position:0% +solid between gas and solid is very poor + + + align:start position:0% +solid between gas and solid is very poor +think about it what's transferring the + + align:start position:0% +think about it what's transferring the + + + align:start position:0% +think about it what's transferring the +heat it's the atoms and the atom density + + align:start position:0% +heat it's the atoms and the atom density + + + align:start position:0% +heat it's the atoms and the atom density +in a gas is sparse SO gas is a very poor + + align:start position:0% +in a gas is sparse SO gas is a very poor + + + align:start position:0% +in a gas is sparse SO gas is a very poor +heat transfer medium so we must avoid + + align:start position:0% +heat transfer medium so we must avoid + + + align:start position:0% +heat transfer medium so we must avoid +boiling if we get boiling then we get + + align:start position:0% +boiling if we get boiling then we get + + + align:start position:0% +boiling if we get boiling then we get +into a thermal runaway situation because + + align:start position:0% +into a thermal runaway situation because + + + align:start position:0% +into a thermal runaway situation because +now we got boiling in the first place + + align:start position:0% +now we got boiling in the first place + + + align:start position:0% +now we got boiling in the first place +cuz the water was too hot but now we're + + align:start position:0% +cuz the water was too hot but now we're + + + align:start position:0% +cuz the water was too hot but now we're +doing a less efficient job of cooling + + align:start position:0% +doing a less efficient job of cooling + + + align:start position:0% +doing a less efficient job of cooling +and it's going to get worse and worse + + align:start position:0% +and it's going to get worse and worse + + + align:start position:0% +and it's going to get worse and worse +and worse until finally boom so what I + + align:start position:0% +and worse until finally boom so what I + + + align:start position:0% +and worse until finally boom so what I +want to do is I want to get my liquid + + align:start position:0% +want to do is I want to get my liquid + + + align:start position:0% +want to do is I want to get my liquid +range I want to tailor the properties of + + align:start position:0% +range I want to tailor the properties of + + + align:start position:0% +range I want to tailor the properties of +the coolant I want a coolant that will + + align:start position:0% +the coolant I want a coolant that will + + + align:start position:0% +the coolant I want a coolant that will +be boil over prooof so if I could raise + + align:start position:0% +be boil over prooof so if I could raise + + + align:start position:0% +be boil over prooof so if I could raise +the boiling point that would make the + + align:start position:0% +the boiling point that would make the + + + align:start position:0% +the boiling point that would make the +car safer to drive under extreme + + align:start position:0% +car safer to drive under extreme + + + align:start position:0% +car safer to drive under extreme +conditions typically what happens is + + align:start position:0% +conditions typically what happens is + + + align:start position:0% +conditions typically what happens is +you're zooming down the highway on a hot + + align:start position:0% +you're zooming down the highway on a hot + + + align:start position:0% +you're zooming down the highway on a hot +summer's day and then there's a some + + align:start position:0% +summer's day and then there's a some + + + align:start position:0% +summer's day and then there's a some +reason to come to an abrupt stop and + + align:start position:0% +reason to come to an abrupt stop and + + + align:start position:0% +reason to come to an abrupt stop and +then there's all that heat to be + + align:start position:0% +then there's all that heat to be + + + align:start position:0% +then there's all that heat to be +dissipated and no more do you get the + + align:start position:0% +dissipated and no more do you get the + + + align:start position:0% +dissipated and no more do you get the +benefit of the motion of the car now + + align:start position:0% +benefit of the motion of the car now + + + align:start position:0% +benefit of the motion of the car now +you're just relying on the fan so what + + align:start position:0% +you're just relying on the fan so what + + + align:start position:0% +you're just relying on the fan so what +can we do if we go to the top of Everest + + align:start position:0% +can we do if we go to the top of Everest + + + align:start position:0% +can we do if we go to the top of Everest +and the pressure goes down and the + + align:start position:0% +and the pressure goes down and the + + + align:start position:0% +and the pressure goes down and the +boiling point Falls could I raise the + + align:start position:0% +boiling point Falls could I raise the + + + align:start position:0% +boiling point Falls could I raise the +boiling point by applying more pressure + + align:start position:0% +boiling point by applying more pressure + + + align:start position:0% +boiling point by applying more pressure +yeah let's put a pressure cap on the + + align:start position:0% +yeah let's put a pressure cap on the + + + align:start position:0% +yeah let's put a pressure cap on the +radiator let's keep the contents of the + + align:start position:0% +radiator let's keep the contents of the + + + align:start position:0% +radiator let's keep the contents of the +radiator high and if you read the top + + align:start position:0% +radiator high and if you read the top + + + align:start position:0% +radiator high and if you read the top +it'll say 15 psi which is one atmosphere + + align:start position:0% +it'll say 15 psi which is one atmosphere + + + align:start position:0% +it'll say 15 psi which is one atmosphere +so I've got one atmosphere here plus an + + align:start position:0% +so I've got one atmosphere here plus an + + + align:start position:0% +so I've got one atmosphere here plus an +extra atmosphere so I'm running at two + + align:start position:0% +extra atmosphere so I'm running at two + + + align:start position:0% +extra atmosphere so I'm running at two +atmospheres pressure so that will raise + + align:start position:0% +atmospheres pressure so that will raise + + + align:start position:0% +atmospheres pressure so that will raise +the boiling point and Stave off the + + align:start position:0% +the boiling point and Stave off the + + + align:start position:0% +the boiling point and Stave off the +dangerous gas Evolution and then I can + + align:start position:0% +dangerous gas Evolution and then I can + + + align:start position:0% +dangerous gas Evolution and then I can +do one more thing instead of running + + align:start position:0% +do one more thing instead of running + + + align:start position:0% +do one more thing instead of running +pure water I will add ethylene + + align:start position:0% +pure water I will add ethylene + + + align:start position:0% +pure water I will add ethylene +glycol I'll add ethylene glycol about 50 + + align:start position:0% +glycol I'll add ethylene glycol about 50 + + + align:start position:0% +glycol I'll add ethylene glycol about 50 +per volume you know this is antifreeze + + align:start position:0% +per volume you know this is antifreeze + + + align:start position:0% +per volume you know this is antifreeze +it gives a freezing point depression + + align:start position:0% +it gives a freezing point depression + + + align:start position:0% +it gives a freezing point depression +we'll talk talk about that next day but + + align:start position:0% +we'll talk talk about that next day but + + + align:start position:0% +we'll talk talk about that next day but +it also gives boiling point elevation so + + align:start position:0% +it also gives boiling point elevation so + + + align:start position:0% +it also gives boiling point elevation so +in the summertime you should always run + + align:start position:0% +in the summertime you should always run + + + align:start position:0% +in the summertime you should always run +with antifreeze because the combination + + align:start position:0% +with antifreeze because the combination + + + align:start position:0% +with antifreeze because the combination +of the pressure cap plus the addition of + + align:start position:0% +of the pressure cap plus the addition of + + + align:start position:0% +of the pressure cap plus the addition of +the glycol raises the boiling point from + + align:start position:0% +the glycol raises the boiling point from + + + align:start position:0% +the glycol raises the boiling point from +212 I'm talking about car so I'm going + + align:start position:0% +212 I'm talking about car so I'm going + + + align:start position:0% +212 I'm talking about car so I'm going +to use Fahrenheit here 212° Fahrenheit + + align:start position:0% +to use Fahrenheit here 212° Fahrenheit + + + align:start position:0% +to use Fahrenheit here 212° Fahrenheit +to + + align:start position:0% +to + + + align:start position:0% +to +265° fahr this buys you a much higher + + align:start position:0% +265° fahr this buys you a much higher + + + align:start position:0% +265° fahr this buys you a much higher +cushion so what are we doing we're + + align:start position:0% +cushion so what are we doing we're + + + align:start position:0% +cushion so what are we doing we're +tailoring this by making the boiling + + align:start position:0% +tailoring this by making the boiling + + + align:start position:0% +tailoring this by making the boiling +point a function of pressure and now I'm + + align:start position:0% +point a function of pressure and now I'm + + + align:start position:0% +point a function of pressure and now I'm +showing you that it's also a function of + + align:start position:0% +showing you that it's also a function of + + + align:start position:0% +showing you that it's also a function of +composition so this whole business of + + align:start position:0% +composition so this whole business of + + + align:start position:0% +composition so this whole business of +solid state stability I hope I'm showing + + align:start position:0% +solid state stability I hope I'm showing + + + align:start position:0% +solid state stability I hope I'm showing +you has a little bit more to it than + + align:start position:0% +you has a little bit more to it than + + + align:start position:0% +you has a little bit more to it than +just looking up the transformation + + align:start position:0% +just looking up the transformation + + + align:start position:0% +just looking up the transformation +temperature on the periodic table or the + + align:start position:0% +temperature on the periodic table or the + + + align:start position:0% +temperature on the periodic table or the +handbook so I want to talk to you for + + align:start position:0% +handbook so I want to talk to you for + + + align:start position:0% +handbook so I want to talk to you for +the next three lectures about phase + + align:start position:0% +the next three lectures about phase + + + align:start position:0% +the next three lectures about phase +diagrams phase diagrams are atlases + + align:start position:0% +diagrams phase diagrams are atlases + + + align:start position:0% +diagrams phase diagrams are atlases +they're Maps they're maps of stability + + align:start position:0% +they're Maps they're maps of stability + + + align:start position:0% +they're Maps they're maps of stability +that answer the question if you specify + + align:start position:0% +that answer the question if you specify + + + align:start position:0% +that answer the question if you specify +pressure composition temperature what + + align:start position:0% +pressure composition temperature what + + + align:start position:0% +pressure composition temperature what +are the stable phases so that's what you + + align:start position:0% +are the stable phases so that's what you + + + align:start position:0% +are the stable phases so that's what you +need to know so let's talk about phase + + align:start position:0% +need to know so let's talk about phase + + + align:start position:0% +need to know so let's talk about phase +diagrams phase + + align:start position:0% +diagrams phase + + + align:start position:0% +diagrams phase +diagrams as stability + + align:start position:0% +diagrams as stability + + + align:start position:0% +diagrams as stability +Maps stability Maps the stability of + + align:start position:0% +Maps stability Maps the stability of + + + align:start position:0% +Maps stability Maps the stability of +what the stability of the state of + + align:start position:0% +what the stability of the state of + + + align:start position:0% +what the stability of the state of +aggregation it's going to tell us if + + align:start position:0% +aggregation it's going to tell us if + + + align:start position:0% +aggregation it's going to tell us if +it's solid liquid gas + + align:start position:0% +it's solid liquid gas + + + align:start position:0% +it's solid liquid gas +and under what + + align:start position:0% +and under what + + + align:start position:0% +and under what +circumstances so let's look at some uh + + align:start position:0% +circumstances so let's look at some uh + + + align:start position:0% +circumstances so let's look at some uh +simple phase diagrams but before we can + + align:start position:0% +simple phase diagrams but before we can + + + align:start position:0% +simple phase diagrams but before we can +do it I need to Define some terms for + + align:start position:0% +do it I need to Define some terms for + + + align:start position:0% +do it I need to Define some terms for +you so first of all let's define the + + align:start position:0% +you so first of all let's define the + + + align:start position:0% +you so first of all let's define the +term phase the phase is a region of a + + align:start position:0% +term phase the phase is a region of a + + + align:start position:0% +term phase the phase is a region of a +substance a region of a substance that + + align:start position:0% +substance a region of a substance that + + + align:start position:0% +substance a region of a substance that +has the following + + align:start position:0% +has the following + + + align:start position:0% +has the following +characteristics + + align:start position:0% +characteristics + + + align:start position:0% +characteristics +uniform and chemical + + align:start position:0% +uniform and chemical + + + align:start position:0% +uniform and chemical +composition it's uniform in chemical + + align:start position:0% +composition it's uniform in chemical + + + align:start position:0% +composition it's uniform in chemical +composition the second thing about it is + + align:start position:0% +composition the second thing about it is + + + align:start position:0% +composition the second thing about it is +that it's physically + + align:start position:0% +that it's physically + + + align:start position:0% +that it's physically +distinct physically distinct and I'll + + align:start position:0% +distinct physically distinct and I'll + + + align:start position:0% +distinct physically distinct and I'll +give you some rich examples I I want put + + align:start position:0% +give you some rich examples I I want put + + + align:start position:0% +give you some rich examples I I want put +this down just to document it and then + + align:start position:0% +this down just to document it and then + + + align:start position:0% +this down just to document it and then +after you see a few examples these words + + align:start position:0% +after you see a few examples these words + + + align:start position:0% +after you see a few examples these words +will mean something to you so it's + + align:start position:0% +will mean something to you so it's + + + align:start position:0% +will mean something to you so it's +physically distinct and uh in the + + align:start position:0% +physically distinct and uh in the + + + align:start position:0% +physically distinct and uh in the +extreme it's mechanically + + align:start position:0% +extreme it's mechanically + + + align:start position:0% +extreme it's mechanically +separable it's mechanically + + align:start position:0% + + + + align:start position:0% + +separable physically distinct and + + align:start position:0% +separable physically distinct and + + + align:start position:0% +separable physically distinct and +mechanically separable so let's look at + + align:start position:0% +mechanically separable so let's look at + + + align:start position:0% +mechanically separable so let's look at +some examples of one phase and two-phase + + align:start position:0% +some examples of one phase and two-phase + + + align:start position:0% +some examples of one phase and two-phase +systems and you this is one of these + + align:start position:0% +systems and you this is one of these + + + align:start position:0% +systems and you this is one of these +days where we we're using symbols to + + align:start position:0% +days where we we're using symbols to + + + align:start position:0% +days where we we're using symbols to +mean multiple meanings I've already used + + align:start position:0% +mean multiple meanings I've already used + + + align:start position:0% +mean multiple meanings I've already used +P to represent pressure if I use P now + + align:start position:0% +P to represent pressure if I use P now + + + align:start position:0% +P to represent pressure if I use P now +to represent number of phases you won't + + align:start position:0% +to represent number of phases you won't + + + align:start position:0% +to represent number of phases you won't +be able to tell one from the other so I + + align:start position:0% +be able to tell one from the other so I + + + align:start position:0% +be able to tell one from the other so I +feel a little bit Western today so I'll + + align:start position:0% +feel a little bit Western today so I'll + + + align:start position:0% +feel a little bit Western today so I'll +make it Circle P so Circle P equals + + align:start position:0% +make it Circle P so Circle P equals + + + align:start position:0% +make it Circle P so Circle P equals +number of phases not to be confused with + + align:start position:0% +number of phases not to be confused with + + + align:start position:0% +number of phases not to be confused with +P which is the pressure so number of + + align:start position:0% +P which is the pressure so number of + + + align:start position:0% +P which is the pressure so number of +phases I designate by Circle P so let's + + align:start position:0% +phases I designate by Circle P so let's + + + align:start position:0% +phases I designate by Circle P so let's +look at some uh simple single phase + + align:start position:0% +look at some uh simple single phase + + + align:start position:0% +look at some uh simple single phase +systems so let's look at P equal 1 P + + align:start position:0% +systems so let's look at P equal 1 P + + + align:start position:0% +systems so let's look at P equal 1 P +equal 1 so how about pure + + align:start position:0% +equal 1 so how about pure + + + align:start position:0% +equal 1 so how about pure +water pure water + + align:start position:0% +water pure water + + + align:start position:0% +water pure water +liquid I have a beaker of water it's + + align:start position:0% +liquid I have a beaker of water it's + + + align:start position:0% +liquid I have a beaker of water it's +uniform and chemical composition + + align:start position:0% +uniform and chemical composition + + + align:start position:0% +uniform and chemical composition +physically distinct mechanically + + align:start position:0% +physically distinct mechanically + + + align:start position:0% +physically distinct mechanically +separable how about uh how about white + + align:start position:0% +separable how about uh how about white + + + align:start position:0% +separable how about uh how about white +gold white gold white gold consists of + + align:start position:0% +gold white gold white gold consists of + + + align:start position:0% +gold white gold white gold consists of +an alloy of certainly gold to which we + + align:start position:0% +an alloy of certainly gold to which we + + + align:start position:0% +an alloy of certainly gold to which we +add silver and we add nickel and these + + align:start position:0% +add silver and we add nickel and these + + + align:start position:0% +add silver and we add nickel and these +are all FCC metals and at the atomistic + + align:start position:0% +are all FCC metals and at the atomistic + + + align:start position:0% +are all FCC metals and at the atomistic +level you have them substituting for one + + align:start position:0% +level you have them substituting for one + + + align:start position:0% +level you have them substituting for one +another on the gold lattice and so I + + align:start position:0% +another on the gold lattice and so I + + + align:start position:0% +another on the gold lattice and so I +have uniform chemical composition I have + + align:start position:0% +have uniform chemical composition I have + + + align:start position:0% +have uniform chemical composition I have +no boundaries there could be grain + + align:start position:0% +no boundaries there could be grain + + + align:start position:0% +no boundaries there could be grain +boundaries but that's different but it + + align:start position:0% +boundaries but that's different but it + + + align:start position:0% +boundaries but that's different but it +the grain boundaries do not represent + + align:start position:0% +the grain boundaries do not represent + + + align:start position:0% +the grain boundaries do not represent +something that is uh a difference in + + align:start position:0% +something that is uh a difference in + + + align:start position:0% +something that is uh a difference in +chemical composition so this is this is + + align:start position:0% +chemical composition so this is this is + + + align:start position:0% +chemical composition so this is this is +pure and this is a solution so if it's a + + align:start position:0% +pure and this is a solution so if it's a + + + align:start position:0% +pure and this is a solution so if it's a +pure material or a solution + + align:start position:0% +pure material or a solution + + + align:start position:0% +pure material or a solution +solution it will qualify a single phase + + align:start position:0% +solution it will qualify a single phase + + + align:start position:0% +solution it will qualify a single phase +okay um let's look so here's a liquid + + align:start position:0% +okay um let's look so here's a liquid + + + align:start position:0% +okay um let's look so here's a liquid +here's a solid let's look at a gas how + + align:start position:0% +here's a solid let's look at a gas how + + + align:start position:0% +here's a solid let's look at a gas how +about air air is a solution of nitrogen + + align:start position:0% +about air air is a solution of nitrogen + + + align:start position:0% +about air air is a solution of nitrogen +oxygen argon increasingly CO2 in the + + align:start position:0% +oxygen argon increasingly CO2 in the + + + align:start position:0% +oxygen argon increasingly CO2 in the +city when you got coal burning for + + align:start position:0% +city when you got coal burning for + + + align:start position:0% +city when you got coal burning for +electric power there's so SO2 oh let's + + align:start position:0% +electric power there's so SO2 oh let's + + + align:start position:0% +electric power there's so SO2 oh let's +not forget our pal nitrous oxide and if + + align:start position:0% +not forget our pal nitrous oxide and if + + + align:start position:0% +not forget our pal nitrous oxide and if +you live near an Alcoa smelter you'll + + align:start position:0% +you live near an Alcoa smelter you'll + + + align:start position:0% +you live near an Alcoa smelter you'll +have cf4 if you live near a magnesium + + align:start position:0% +have cf4 if you live near a magnesium + + + align:start position:0% +have cf4 if you live near a magnesium +smel melter you'll smell chlorine but in + + align:start position:0% +smel melter you'll smell chlorine but in + + + align:start position:0% +smel melter you'll smell chlorine but in +Cambridge mercifully we just have to + + align:start position:0% +Cambridge mercifully we just have to + + + align:start position:0% +Cambridge mercifully we just have to +enjoy these so and this is all single + + align:start position:0% +enjoy these so and this is all single + + + align:start position:0% +enjoy these so and this is all single +phase you don't see the gases settling + + align:start position:0% +phase you don't see the gases settling + + + align:start position:0% +phase you don't see the gases settling +according to density they mix intimately + + align:start position:0% +according to density they mix intimately + + + align:start position:0% +according to density they mix intimately +in all proportions and one more solid uh + + align:start position:0% +in all proportions and one more solid uh + + + align:start position:0% +in all proportions and one more solid uh +calcio + + align:start position:0% +calcio + + + align:start position:0% +calcio +zerconia we talked about this one before + + align:start position:0% +zerconia we talked about this one before + + + align:start position:0% +zerconia we talked about this one before +this is the lime stabilized zerconia for + + align:start position:0% +this is the lime stabilized zerconia for + + + align:start position:0% +this is the lime stabilized zerconia for +oxygen sensors and I'll show you later + + align:start position:0% +oxygen sensors and I'll show you later + + + align:start position:0% +oxygen sensors and I'll show you later +that this is the uh material that's used + + align:start position:0% +that this is the uh material that's used + + + align:start position:0% +that this is the uh material that's used +for uh the faux Diamond this is a solid + + align:start position:0% +for uh the faux Diamond this is a solid + + + align:start position:0% +for uh the faux Diamond this is a solid +solution + + align:start position:0% +solution + + + align:start position:0% +solution +calcium ion sitting on zirconium site so + + align:start position:0% +calcium ion sitting on zirconium site so + + + align:start position:0% +calcium ion sitting on zirconium site so +this is single phase there's no calcium + + align:start position:0% +this is single phase there's no calcium + + + align:start position:0% +this is single phase there's no calcium +Island calcium oxide islands and + + align:start position:0% +Island calcium oxide islands and + + + align:start position:0% +Island calcium oxide islands and +zirconium oxide Islands this is a solid + + align:start position:0% +zirconium oxide Islands this is a solid + + + align:start position:0% +zirconium oxide Islands this is a solid +solution so therefore it's all one phase + + align:start position:0% +solution so therefore it's all one phase + + + align:start position:0% +solution so therefore it's all one phase +now let's contrast that to something + + align:start position:0% +now let's contrast that to something + + + align:start position:0% +now let's contrast that to something +that's two-phase to get a sense of what + + align:start position:0% +that's two-phase to get a sense of what + + + align:start position:0% +that's two-phase to get a sense of what +the difference is so instead of pure + + align:start position:0% +the difference is so instead of pure + + + align:start position:0% +the difference is so instead of pure +water just liquid suppose I have ice + + align:start position:0% +water just liquid suppose I have ice + + + align:start position:0% +water just liquid suppose I have ice +cubes ice cubes in water ice cubes in + + align:start position:0% +cubes ice cubes in water ice cubes in + + + align:start position:0% +cubes ice cubes in water ice cubes in +water it's still pure I didn't change + + align:start position:0% +water it's still pure I didn't change + + + align:start position:0% +water it's still pure I didn't change +the composition but I've got two + + align:start position:0% +the composition but I've got two + + + align:start position:0% +the composition but I've got two +different states I've got two different + + align:start position:0% +different states I've got two different + + + align:start position:0% +different states I've got two different +states I've got a solid state and a + + align:start position:0% +states I've got a solid state and a + + + align:start position:0% +states I've got a solid state and a +liquid state and this fits the fits the + + align:start position:0% +liquid state and this fits the fits the + + + align:start position:0% +liquid state and this fits the fits the +definition in other words the ice + + align:start position:0% +definition in other words the ice + + + align:start position:0% +definition in other words the ice +floating in the water is uniform in + + align:start position:0% +floating in the water is uniform in + + + align:start position:0% +floating in the water is uniform in +chemical composition and it's physically + + align:start position:0% +chemical composition and it's physically + + + align:start position:0% +chemical composition and it's physically +distinct or I can say I can put a + + align:start position:0% +distinct or I can say I can put a + + + align:start position:0% +distinct or I can say I can put a +boundary around it and I can isolate all + + align:start position:0% +boundary around it and I can isolate all + + + align:start position:0% +boundary around it and I can isolate all +of the ice cubes and in fact these are + + align:start position:0% +of the ice cubes and in fact these are + + + align:start position:0% +of the ice cubes and in fact these are +mechanically separable I could pull out + + align:start position:0% +mechanically separable I could pull out + + + align:start position:0% +mechanically separable I could pull out +all of the ice cubes and be left with + + align:start position:0% +all of the ice cubes and be left with + + + align:start position:0% +all of the ice cubes and be left with +only the liquid + + align:start position:0% +only the liquid + + + align:start position:0% +only the liquid +okay solid and liquid two different + + align:start position:0% +okay solid and liquid two different + + + align:start position:0% +okay solid and liquid two different +phases because they're two different + + align:start position:0% +phases because they're two different + + + align:start position:0% +phases because they're two different +states of the same material I think uh + + align:start position:0% +states of the same material I think uh + + + align:start position:0% +states of the same material I think uh +we also looked at milk we looked at milk + + align:start position:0% +we also looked at milk we looked at milk + + + align:start position:0% +we also looked at milk we looked at milk +and milk has fat + + align:start position:0% +and milk has fat + + + align:start position:0% +and milk has fat +globules in the aquous + + align:start position:0% +globules in the aquous + + + align:start position:0% +globules in the aquous +phase in the aquous solution all right + + align:start position:0% +phase in the aquous solution all right + + + align:start position:0% +phase in the aquous solution all right +so I've got fat globules they're very + + align:start position:0% +so I've got fat globules they're very + + + align:start position:0% +so I've got fat globules they're very +tiny and they scatter light but if we + + align:start position:0% +tiny and they scatter light but if we + + + align:start position:0% +tiny and they scatter light but if we +got down to the micro level we could + + align:start position:0% +got down to the micro level we could + + + align:start position:0% +got down to the micro level we could +find these fat globules as something + + align:start position:0% +find these fat globules as something + + + align:start position:0% +find these fat globules as something +that's + + align:start position:0% +that's + + + align:start position:0% +that's +mechanically uh separable physically + + align:start position:0% +mechanically uh separable physically + + + align:start position:0% +mechanically uh separable physically +distinct and of uniform composition and + + align:start position:0% +distinct and of uniform composition and + + + align:start position:0% +distinct and of uniform composition and +different from this so this is two + + align:start position:0% +different from this so this is two + + + align:start position:0% +different from this so this is two +different phases because we have two + + align:start position:0% +different phases because we have two + + + align:start position:0% +different phases because we have two +different + + align:start position:0% +different + + + align:start position:0% +different +compositions we have two different + + align:start position:0% +compositions we have two different + + + align:start position:0% +compositions we have two different +compositions and lastly uh there was the + + align:start position:0% +compositions and lastly uh there was the + + + align:start position:0% +compositions and lastly uh there was the +Visions the Visions cookware the + + align:start position:0% +Visions the Visions cookware the + + + align:start position:0% +Visions the Visions cookware the +pyroceram the Pyro seram that was the + + align:start position:0% +pyroceram the Pyro seram that was the + + + align:start position:0% +pyroceram the Pyro seram that was the +glass + + align:start position:0% +glass + + + align:start position:0% +glass +ceramic the glass ceramic that's 95% + + align:start position:0% +ceramic the glass ceramic that's 95% + + + align:start position:0% +ceramic the glass ceramic that's 95% +crystallin and 5% glassy so which you + + align:start position:0% +crystallin and 5% glassy so which you + + + align:start position:0% +crystallin and 5% glassy so which you +have here is you have a glassy + + align:start position:0% +have here is you have a glassy + + + align:start position:0% +have here is you have a glassy +phase glassy + + align:start position:0% +phase glassy + + + align:start position:0% +phase glassy +Matrix and + + align:start position:0% +Matrix and + + + align:start position:0% +Matrix and +crystallin crystallin + + align:start position:0% +crystallin crystallin + + + align:start position:0% +crystallin crystallin +precipitates okay so again we don't have + + align:start position:0% +precipitates okay so again we don't have + + + align:start position:0% +precipitates okay so again we don't have +a change in composition but we have a + + align:start position:0% +a change in composition but we have a + + + align:start position:0% +a change in composition but we have a +change in order in atomic order so the + + align:start position:0% +change in order in atomic order so the + + + align:start position:0% +change in order in atomic order so the +glassy phase and the devitrified phase + + align:start position:0% +glassy phase and the devitrified phase + + + align:start position:0% +glassy phase and the devitrified phase +so we can actually draw boundaries + + align:start position:0% +so we can actually draw boundaries + + + align:start position:0% +so we can actually draw boundaries +around all the crystallin precipitate so + + align:start position:0% +around all the crystallin precipitate so + + + align:start position:0% +around all the crystallin precipitate so +I I hope this gives you a sense of what + + align:start position:0% +I I hope this gives you a sense of what + + + align:start position:0% +I I hope this gives you a sense of what +what's going on on here the second thing + + align:start position:0% +what's going on on here the second thing + + + align:start position:0% +what's going on on here the second thing +is that uh these phase diagrams are + + align:start position:0% +is that uh these phase diagrams are + + + align:start position:0% +is that uh these phase diagrams are +drawn under conditions called + + align:start position:0% +drawn under conditions called + + + align:start position:0% +drawn under conditions called +equilibrium that's why we talk about + + align:start position:0% +equilibrium that's why we talk about + + + align:start position:0% +equilibrium that's why we talk about +stability so let's define + + align:start position:0% + + + + align:start position:0% + +equilibrium equilibrium is a + + align:start position:0% +equilibrium equilibrium is a + + + align:start position:0% +equilibrium equilibrium is a +condition which represents the lowest + + align:start position:0% +condition which represents the lowest + + + align:start position:0% +condition which represents the lowest +energy state of the system the lowest + + align:start position:0% +energy state of the system the lowest + + + align:start position:0% +energy state of the system the lowest +energy state in other words if you take + + align:start position:0% +energy state in other words if you take + + + align:start position:0% +energy state in other words if you take +all of the constituents and give them + + align:start position:0% +all of the constituents and give them + + + align:start position:0% +all of the constituents and give them +infinite time and the energy they need + + align:start position:0% +infinite time and the energy they need + + + align:start position:0% +infinite time and the energy they need +to achieve the lowest energy State this + + align:start position:0% +to achieve the lowest energy State this + + + align:start position:0% +to achieve the lowest energy State this +is where they will get to and we will + + align:start position:0% +is where they will get to and we will + + + align:start position:0% +is where they will get to and we will +know that it's the equilibrium State + + align:start position:0% +know that it's the equilibrium State + + + align:start position:0% +know that it's the equilibrium State +because the properties are invariant + + align:start position:0% +because the properties are invariant + + + align:start position:0% +because the properties are invariant +properties are invariant with time this + + align:start position:0% +properties are invariant with time this + + + align:start position:0% +properties are invariant with time this +is sort of like a steady state but + + align:start position:0% +is sort of like a steady state but + + + align:start position:0% +is sort of like a steady state but +steady state is something that could be + + align:start position:0% +steady state is something that could be + + + align:start position:0% +steady state is something that could be +sort of locked in on the road to + + align:start position:0% +sort of locked in on the road to + + + align:start position:0% +sort of locked in on the road to +stability so this is the ultimate + + align:start position:0% +stability so this is the ultimate + + + align:start position:0% +stability so this is the ultimate +stability as contrasted with + + align:start position:0% +stability as contrasted with + + + align:start position:0% +stability as contrasted with +metastability metastability + + align:start position:0% +metastability metastability + + + align:start position:0% +metastability metastability +is something that's steady state but + + align:start position:0% +is something that's steady state but + + + align:start position:0% +is something that's steady state but +could get Stabler yet and the example of + + align:start position:0% +could get Stabler yet and the example of + + + align:start position:0% +could get Stabler yet and the example of +meta stability is + + align:start position:0% +meta stability is + + + align:start position:0% +meta stability is +Diamond which is not the stable form of + + align:start position:0% +Diamond which is not the stable form of + + + align:start position:0% +Diamond which is not the stable form of +carbon at room temperature but Diamond + + align:start position:0% +carbon at room temperature but Diamond + + + align:start position:0% +carbon at room temperature but Diamond +was formed under different conditions + + align:start position:0% +was formed under different conditions + + + align:start position:0% +was formed under different conditions +and then brought under ambient pressure + + align:start position:0% +and then brought under ambient pressure + + + align:start position:0% +and then brought under ambient pressure +and temperature but the activation + + align:start position:0% +and temperature but the activation + + + align:start position:0% +and temperature but the activation +energy to convert is so high that it + + align:start position:0% +energy to convert is so high that it + + + align:start position:0% +energy to convert is so high that it +stays apparently stable but in point of + + align:start position:0% +stays apparently stable but in point of + + + align:start position:0% +stays apparently stable but in point of +fact it's metastable another one is + + align:start position:0% +fact it's metastable another one is + + + align:start position:0% +fact it's metastable another one is +metallic glass metallic glass we know + + align:start position:0% +metallic glass metallic glass we know + + + align:start position:0% +metallic glass metallic glass we know +that metallic glass was formed under + + align:start position:0% +that metallic glass was formed under + + + align:start position:0% +that metallic glass was formed under +high quench rates if you take metallic + + align:start position:0% +high quench rates if you take metallic + + + align:start position:0% +high quench rates if you take metallic +glass and Heat it moderately you will + + align:start position:0% +glass and Heat it moderately you will + + + align:start position:0% +glass and Heat it moderately you will +give it sufficient activation energy to + + align:start position:0% +give it sufficient activation energy to + + + align:start position:0% +give it sufficient activation energy to +then jump from this glassy state to the + + align:start position:0% +then jump from this glassy state to the + + + align:start position:0% +then jump from this glassy state to the +crystallin state and ultimately achieve + + align:start position:0% +crystallin state and ultimately achieve + + + align:start position:0% +crystallin state and ultimately achieve +its its equilibrium value its + + align:start position:0% +its its equilibrium value its + + + align:start position:0% +its its equilibrium value its +equilibrium value so those are examples + + align:start position:0% +equilibrium value so those are examples + + + align:start position:0% +equilibrium value so those are examples +of the + + align:start position:0% +of the + + + align:start position:0% +of the +uh equilibrium metastability and then + + align:start position:0% +uh equilibrium metastability and then + + + align:start position:0% +uh equilibrium metastability and then +the last thing as you noticed I talked + + align:start position:0% +the last thing as you noticed I talked + + + align:start position:0% +the last thing as you noticed I talked +about pure materials and then + + align:start position:0% +about pure materials and then + + + align:start position:0% +about pure materials and then +multicomponent materials they have + + align:start position:0% +multicomponent materials they have + + + align:start position:0% +multicomponent materials they have +different uh elements that are mixed and + + align:start position:0% +different uh elements that are mixed and + + + align:start position:0% +different uh elements that are mixed and +so we need a counter a metric that uh + + align:start position:0% +so we need a counter a metric that uh + + + align:start position:0% +so we need a counter a metric that uh +details what the level of chemical + + align:start position:0% +details what the level of chemical + + + align:start position:0% +details what the level of chemical +complexity is and for that we call in to + + align:start position:0% +complexity is and for that we call in to + + + align:start position:0% +complexity is and for that we call in to +play a term called + + align:start position:0% +play a term called + + + align:start position:0% +play a term called +component component and it's the measure + + align:start position:0% +component component and it's the measure + + + align:start position:0% +component component and it's the measure +measure of chemical + + align:start position:0% +measure of chemical + + + align:start position:0% +measure of chemical +complexity measure of chemical + + align:start position:0% +complexity measure of chemical + + + align:start position:0% +complexity measure of chemical +complexity what do I mean by that in the + + align:start position:0% +complexity what do I mean by that in the + + + align:start position:0% +complexity what do I mean by that in the +simplest in the simplest terms how many + + align:start position:0% +simplest in the simplest terms how many + + + align:start position:0% +simplest in the simplest terms how many +bottles do I have to pull off the shelf + + align:start position:0% +bottles do I have to pull off the shelf + + + align:start position:0% +bottles do I have to pull off the shelf +to make this thing okay bottles off the + + align:start position:0% + + + + align:start position:0% + +shelf and again this is best best given + + align:start position:0% +shelf and again this is best best given + + + align:start position:0% +shelf and again this is best best given +by uh illustration so I I'll show you a + + align:start position:0% +by uh illustration so I I'll show you a + + + align:start position:0% +by uh illustration so I I'll show you a +mix of components and phases so we'll do + + align:start position:0% +mix of components and phases so we'll do + + + align:start position:0% +mix of components and phases so we'll do +a little Matrix here start on a new + + align:start position:0% +a little Matrix here start on a new + + + align:start position:0% +a little Matrix here start on a new +board + + align:start position:0% + + + + align:start position:0% + +so okay so AC cross the across the top + + align:start position:0% +so okay so AC cross the across the top + + + align:start position:0% +so okay so AC cross the across the top +I'll look at single phase and dual phase + + align:start position:0% +I'll look at single phase and dual phase + + + align:start position:0% +I'll look at single phase and dual phase +and down the column I'll look at one + + align:start position:0% +and down the column I'll look at one + + + align:start position:0% +and down the column I'll look at one +component two component three component + + align:start position:0% +component two component three component + + + align:start position:0% +component two component three component +systems so the simplest is up here one + + align:start position:0% +systems so the simplest is up here one + + + align:start position:0% +systems so the simplest is up here one +one one phase one component so that's + + align:start position:0% +one one phase one component so that's + + + align:start position:0% +one one phase one component so that's +pure water pure water all liquid single + + align:start position:0% +pure water pure water all liquid single + + + align:start position:0% +pure water pure water all liquid single +phase single component you can say but + + align:start position:0% +phase single component you can say but + + + align:start position:0% +phase single component you can say but +don't you need hydrogen and oxygen well + + align:start position:0% +don't you need hydrogen and oxygen well + + + align:start position:0% +don't you need hydrogen and oxygen well +if you if you take one of the thermal + + align:start position:0% +if you if you take one of the thermal + + + align:start position:0% +if you if you take one of the thermal +classes later you'll learn that the + + align:start position:0% +classes later you'll learn that the + + + align:start position:0% +classes later you'll learn that the +hydrogen and oxygen are linked by + + align:start position:0% +hydrogen and oxygen are linked by + + + align:start position:0% +hydrogen and oxygen are linked by +stochiometry so it's still one body off + + align:start position:0% +stochiometry so it's still one body off + + + align:start position:0% +stochiometry so it's still one body off +the shelf there's no variation in the + + align:start position:0% +the shelf there's no variation in the + + + align:start position:0% +the shelf there's no variation in the +hydrogen to oxygen ratio um Diamond even + + align:start position:0% +hydrogen to oxygen ratio um Diamond even + + + align:start position:0% +hydrogen to oxygen ratio um Diamond even +though it's metast stable it is all I + + align:start position:0% +though it's metast stable it is all I + + + align:start position:0% +though it's metast stable it is all I +need is carbon so and it's single phase + + align:start position:0% +need is carbon so and it's single phase + + + align:start position:0% +need is carbon so and it's single phase +there's no change of uh phase across the + + align:start position:0% +there's no change of uh phase across the + + + align:start position:0% +there's no change of uh phase across the +diamond in many cases the diamonds that + + align:start position:0% +diamond in many cases the diamonds that + + + align:start position:0% +diamond in many cases the diamonds that +you will see they're all single Crystal + + align:start position:0% +you will see they're all single Crystal + + + align:start position:0% +you will see they're all single Crystal +don't ever go to the jeweler and ask for + + align:start position:0% +don't ever go to the jeweler and ask for + + + align:start position:0% +don't ever go to the jeweler and ask for +poly Crystal and Diamond it's not going + + align:start position:0% +poly Crystal and Diamond it's not going + + + align:start position:0% +poly Crystal and Diamond it's not going +to be very pretty okay please remember + + align:start position:0% +to be very pretty okay please remember + + + align:start position:0% +to be very pretty okay please remember +that um so let's look at something + + align:start position:0% +that um so let's look at something + + + align:start position:0% +that um so let's look at something +that's now uh two components well that + + align:start position:0% +that's now uh two components well that + + + align:start position:0% +that's now uh two components well that +would be uh calcio zerconia right it's + + align:start position:0% +would be uh calcio zerconia right it's + + + align:start position:0% +would be uh calcio zerconia right it's +one phase it's a single solid solution + + align:start position:0% +one phase it's a single solid solution + + + align:start position:0% +one phase it's a single solid solution +but I needed two bottles I needed a + + align:start position:0% +but I needed two bottles I needed a + + + align:start position:0% +but I needed two bottles I needed a +bottle of calcium oxide and a bottle of + + align:start position:0% +bottle of calcium oxide and a bottle of + + + align:start position:0% +bottle of calcium oxide and a bottle of +zirconium oxide but they mix intimately + + align:start position:0% +zirconium oxide but they mix intimately + + + align:start position:0% +zirconium oxide but they mix intimately +and I have a single phase and then the + + align:start position:0% +and I have a single phase and then the + + + align:start position:0% +and I have a single phase and then the +white gold the white gold is the gold + + align:start position:0% +white gold the white gold is the gold + + + align:start position:0% +white gold the white gold is the gold +the silver and the nickel three + + align:start position:0% +the silver and the nickel three + + + align:start position:0% +the silver and the nickel three +different elements they mix intimately + + align:start position:0% +different elements they mix intimately + + + align:start position:0% +different elements they mix intimately +and they give me a single phase over + + align:start position:0% +and they give me a single phase over + + + align:start position:0% +and they give me a single phase over +here I've got one component so I'm + + align:start position:0% +here I've got one component so I'm + + + align:start position:0% +here I've got one component so I'm +working only with say water so this will + + align:start position:0% +working only with say water so this will + + + align:start position:0% +working only with say water so this will +be the ice + + align:start position:0% +be the ice + + + align:start position:0% +be the ice +ice water or I call it slush ice water + + align:start position:0% +ice water or I call it slush ice water + + + align:start position:0% +ice water or I call it slush ice water +slush two phases and they're in + + align:start position:0% +slush two phases and they're in + + + align:start position:0% +slush two phases and they're in +equilibrium so this is at 0 degrees C + + align:start position:0% +equilibrium so this is at 0 degrees C + + + align:start position:0% +equilibrium so this is at 0 degrees C +and they are stable over time all right + + align:start position:0% +and they are stable over time all right + + + align:start position:0% +and they are stable over time all right +the lowest energy state invariant so the + + align:start position:0% +the lowest energy state invariant so the + + + align:start position:0% +the lowest energy state invariant so the +slush remains stable so you can have + + align:start position:0% +slush remains stable so you can have + + + align:start position:0% +slush remains stable so you can have +Dynamics some of the solid dissolves + + align:start position:0% +Dynamics some of the solid dissolves + + + align:start position:0% +Dynamics some of the solid dissolves +into liquid and some of the liquid + + align:start position:0% +into liquid and some of the liquid + + + align:start position:0% +into liquid and some of the liquid +freezes out as solid but the net change + + align:start position:0% +freezes out as solid but the net change + + + align:start position:0% +freezes out as solid but the net change +is zero stable ice water slush uh second + + align:start position:0% +is zero stable ice water slush uh second + + + align:start position:0% +is zero stable ice water slush uh second +one we saw this we talked about + + align:start position:0% +one we saw this we talked about + + + align:start position:0% +one we saw this we talked about +solubility we looked at the mix of + + align:start position:0% +solubility we looked at the mix of + + + align:start position:0% +solubility we looked at the mix of +carbon + + align:start position:0% +carbon + + + align:start position:0% +carbon +tetrachloride and water two liquids we + + align:start position:0% +tetrachloride and water two liquids we + + + align:start position:0% +tetrachloride and water two liquids we +shake them up and they phase separate + + align:start position:0% +shake them up and they phase separate + + + align:start position:0% +shake them up and they phase separate +I've been using that term phase separate + + align:start position:0% +I've been using that term phase separate + + + align:start position:0% +I've been using that term phase separate +two phases there's an organic phase or + + align:start position:0% +two phases there's an organic phase or + + + align:start position:0% +two phases there's an organic phase or +an if you say a carbon Rich phase a + + align:start position:0% +an if you say a carbon Rich phase a + + + align:start position:0% +an if you say a carbon Rich phase a +non-polar phase and a hydrogen bonded + + align:start position:0% +non-polar phase and a hydrogen bonded + + + align:start position:0% +non-polar phase and a hydrogen bonded +phase so these are emiss they're emiss + + align:start position:0% +phase so these are emiss they're emiss + + + align:start position:0% +phase so these are emiss they're emiss +and I will have two components two + + align:start position:0% +and I will have two components two + + + align:start position:0% +and I will have two components two +phases and then the last one this would + + align:start position:0% +phases and then the last one this would + + + align:start position:0% +phases and then the last one this would +be the visions + + align:start position:0% +be the visions + + + align:start position:0% +be the visions +the Visions because that consisted of + + align:start position:0% +the Visions because that consisted of + + + align:start position:0% +the Visions because that consisted of +lithium oxide + + align:start position:0% +lithium oxide + + + align:start position:0% +lithium oxide +alumina and silica I need to get three + + align:start position:0% +alumina and silica I need to get three + + + align:start position:0% +alumina and silica I need to get three +bottles off the shelf remember I had a + + align:start position:0% +bottles off the shelf remember I had a + + + align:start position:0% +bottles off the shelf remember I had a +network former a network modifier and an + + align:start position:0% +network former a network modifier and an + + + align:start position:0% +network former a network modifier and an +intermediate and that gave me this + + align:start position:0% +intermediate and that gave me this + + + align:start position:0% +intermediate and that gave me this +remarkable uh two-phase mixture that I + + align:start position:0% +remarkable uh two-phase mixture that I + + + align:start position:0% +remarkable uh two-phase mixture that I +triggered the uh exsolution of a + + align:start position:0% +triggered the uh exsolution of a + + + align:start position:0% +triggered the uh exsolution of a +crystallin phase so now I want let's + + align:start position:0% +crystallin phase so now I want let's + + + align:start position:0% +crystallin phase so now I want let's +look at some real examples stability + + align:start position:0% +look at some real examples stability + + + align:start position:0% +look at some real examples stability +Maps so I want to + + align:start position:0% +Maps so I want to + + + align:start position:0% +Maps so I want to +start learn to crawl before we learn to + + align:start position:0% +start learn to crawl before we learn to + + + align:start position:0% +start learn to crawl before we learn to +run so let's look look at simple one so + + align:start position:0% +run so let's look look at simple one so + + + align:start position:0% +run so let's look look at simple one so +we're going to put Cals 1 so this is + + align:start position:0% +we're going to put Cals 1 so this is + + + align:start position:0% +we're going to put Cals 1 so this is +pure materials pure materials Cals 1 one + + align:start position:0% +pure materials pure materials Cals 1 one + + + align:start position:0% +pure materials pure materials Cals 1 one +component and we're going to look at + + align:start position:0% +component and we're going to look at + + + align:start position:0% +component and we're going to look at +since we have C C equals 1 it's fixed + + align:start position:0% +since we have C C equals 1 it's fixed + + + align:start position:0% +since we have C C equals 1 it's fixed +all I have left then we have pressure + + align:start position:0% +all I have left then we have pressure + + + align:start position:0% +all I have left then we have pressure +composition temperature composition is + + align:start position:0% +composition temperature composition is + + + align:start position:0% +composition temperature composition is +fixed because it doesn't vary here so I + + align:start position:0% +fixed because it doesn't vary here so I + + + align:start position:0% +fixed because it doesn't vary here so I +just have to look look at P versus T + + align:start position:0% +just have to look look at P versus T + + + align:start position:0% +just have to look look at P versus T +those are the only variables that I have + + align:start position:0% +those are the only variables that I have + + + align:start position:0% +those are the only variables that I have +to deal with so let's look at at some of + + align:start position:0% +to deal with so let's look at at some of + + + align:start position:0% +to deal with so let's look at at some of +these now the first one I want to look + + align:start position:0% +these now the first one I want to look + + + align:start position:0% +these now the first one I want to look +at is one that you're pretty familiar + + align:start position:0% +at is one that you're pretty familiar + + + align:start position:0% +at is one that you're pretty familiar +with water let's look at the phase + + align:start position:0% +with water let's look at the phase + + + align:start position:0% +with water let's look at the phase +diagram of pure water so we're going to + + align:start position:0% +diagram of pure water so we're going to + + + align:start position:0% +diagram of pure water so we're going to +plot how the phases of water vary over + + align:start position:0% +plot how the phases of water vary over + + + align:start position:0% +plot how the phases of water vary over +pressure and temperature and I'm going + + align:start position:0% +pressure and temperature and I'm going + + + align:start position:0% +pressure and temperature and I'm going +to plot temperature in degrees Celsius + + align:start position:0% +to plot temperature in degrees Celsius + + + align:start position:0% +to plot temperature in degrees Celsius +and I'm going to plot temper excuse me + + align:start position:0% +and I'm going to plot temper excuse me + + + align:start position:0% +and I'm going to plot temper excuse me +pressure and atmospheres although I'll + + align:start position:0% +pressure and atmospheres although I'll + + + align:start position:0% +pressure and atmospheres although I'll +give you the conversion to SI so let me + + align:start position:0% +give you the conversion to SI so let me + + + align:start position:0% +give you the conversion to SI so let me +just put the general diagram on it's + + align:start position:0% +just put the general diagram on it's + + + align:start position:0% +just put the general diagram on it's +sort of a a y-shaped looking diagram so + + align:start position:0% +sort of a a y-shaped looking diagram so + + + align:start position:0% +sort of a a y-shaped looking diagram so +lowest temperature this is where we have + + align:start position:0% +lowest temperature this is where we have + + + align:start position:0% +lowest temperature this is where we have +the solid regime solid water ice the + + align:start position:0% +the solid regime solid water ice the + + + align:start position:0% +the solid regime solid water ice the +highest temperature must be where we + + align:start position:0% +highest temperature must be where we + + + align:start position:0% +highest temperature must be where we +have the gas or water vapor and in + + align:start position:0% +have the gas or water vapor and in + + + align:start position:0% +have the gas or water vapor and in +between we have the + + align:start position:0% +between we have the + + + align:start position:0% +between we have the +liquid and these lines represent the + + align:start position:0% +liquid and these lines represent the + + + align:start position:0% +liquid and these lines represent the +equilibria these lines this one is the + + align:start position:0% +equilibria these lines this one is the + + + align:start position:0% +equilibria these lines this one is the +equilibrium between liquid and Vapor + + align:start position:0% +equilibrium between liquid and Vapor + + + align:start position:0% +equilibrium between liquid and Vapor +liquid and Vapor so this is a liquid + + align:start position:0% +liquid and Vapor so this is a liquid + + + align:start position:0% +liquid and Vapor so this is a liquid +equals Vapor coexistence curve + + align:start position:0% +equals Vapor coexistence curve + + + align:start position:0% +equals Vapor coexistence curve +coexistence curve and it's not a single + + align:start position:0% +coexistence curve and it's not a single + + + align:start position:0% +coexistence curve and it's not a single +point + + align:start position:0% +point + + + align:start position:0% +point +this one here is solid liquid + + align:start position:0% +this one here is solid liquid + + + align:start position:0% +this one here is solid liquid +coexistence curve solid equals uh liquid + + align:start position:0% +coexistence curve solid equals uh liquid + + + align:start position:0% +coexistence curve solid equals uh liquid +coexistence + + align:start position:0% +coexistence + + + align:start position:0% +coexistence +curve now you know some of the data + + align:start position:0% +curve now you know some of the data + + + align:start position:0% +curve now you know some of the data +points on this graph we live at one + + align:start position:0% +points on this graph we live at one + + + align:start position:0% +points on this graph we live at one +atmosphere that's our world the one + + align:start position:0% +atmosphere that's our world the one + + + align:start position:0% +atmosphere that's our world the one +atmosphere isobar so let's put P equals + + align:start position:0% +atmosphere isobar so let's put P equals + + + align:start position:0% +atmosphere isobar so let's put P equals +1 and you know that at one atmosphere + + align:start position:0% +1 and you know that at one atmosphere + + + align:start position:0% +1 and you know that at one atmosphere +pure water freezes at 0° C so that's the + + align:start position:0% +pure water freezes at 0° C so that's the + + + align:start position:0% +pure water freezes at 0° C so that's the +point along the solid liquid coexistence + + align:start position:0% +point along the solid liquid coexistence + + + align:start position:0% +point along the solid liquid coexistence +curve at one atmosphere applied pressure + + align:start position:0% +curve at one atmosphere applied pressure + + + align:start position:0% +curve at one atmosphere applied pressure +and furthermore you know that at sea + + align:start position:0% +and furthermore you know that at sea + + + align:start position:0% +and furthermore you know that at sea +level where we have one atmosphere + + align:start position:0% +level where we have one atmosphere + + + align:start position:0% +level where we have one atmosphere +pressure the liquid turns to Vapor at + + align:start position:0% +pressure the liquid turns to Vapor at + + + align:start position:0% +pressure the liquid turns to Vapor at +100 De C at 100° C so when we go to we + + align:start position:0% +100 De C at 100° C so when we go to we + + + align:start position:0% +100 De C at 100° C so when we go to we +go to Mount Everest we're over here see + + align:start position:0% +go to Mount Everest we're over here see + + + align:start position:0% +go to Mount Everest we're over here see +we're at lower pressure and if we're at + + align:start position:0% +we're at lower pressure and if we're at + + + align:start position:0% +we're at lower pressure and if we're at +lower pressure we're at lower + + align:start position:0% +lower pressure we're at lower + + + align:start position:0% +lower pressure we're at lower +temperature and then if we're in + + align:start position:0% +temperature and then if we're in + + + align:start position:0% +temperature and then if we're in +the radiator the cooling system of the + + align:start position:0% +the radiator the cooling system of the + + + align:start position:0% +the radiator the cooling system of the +car we + + align:start position:0% +car we + + + align:start position:0% +car we +applied higher pressure we trapped in a + + align:start position:0% +applied higher pressure we trapped in a + + + align:start position:0% +applied higher pressure we trapped in a +higher pressure and thereby extended the + + align:start position:0% +higher pressure and thereby extended the + + + align:start position:0% +higher pressure and thereby extended the +temperature range over which the liquid + + align:start position:0% +temperature range over which the liquid + + + align:start position:0% +temperature range over which the liquid +is stable see at two atmospheres the + + align:start position:0% +is stable see at two atmospheres the + + + align:start position:0% +is stable see at two atmospheres the +liquid is stable over a wider range of + + align:start position:0% +liquid is stable over a wider range of + + + align:start position:0% +liquid is stable over a wider range of +temperature at one atmosphere it's what + + align:start position:0% +temperature at one atmosphere it's what + + + align:start position:0% +temperature at one atmosphere it's what +we know one to Excuse Me 0 to 100 + + align:start position:0% +we know one to Excuse Me 0 to 100 + + + align:start position:0% +we know one to Excuse Me 0 to 100 +Celsius and at lower at lower pressures + + align:start position:0% +Celsius and at lower at lower pressures + + + align:start position:0% +Celsius and at lower at lower pressures +it's stable over an even narrower + + align:start position:0% +it's stable over an even narrower + + + align:start position:0% +it's stable over an even narrower +temperature range so the boiling point + + align:start position:0% +temperature range so the boiling point + + + align:start position:0% +temperature range so the boiling point +I'm showing you how it varies as a + + align:start position:0% +I'm showing you how it varies as a + + + align:start position:0% +I'm showing you how it varies as a +function of pressure and down here we + + align:start position:0% +function of pressure and down here we + + + align:start position:0% +function of pressure and down here we +have this is solid equals Vapor + + align:start position:0% +have this is solid equals Vapor + + + align:start position:0% +have this is solid equals Vapor +coexistence curve below a certain + + align:start position:0% +coexistence curve below a certain + + + align:start position:0% +coexistence curve below a certain +pressure you can go directly from solid + + align:start position:0% +pressure you can go directly from solid + + + align:start position:0% +pressure you can go directly from solid +to Vapor if you hang your clothes out on + + align:start position:0% +to Vapor if you hang your clothes out on + + + align:start position:0% +to Vapor if you hang your clothes out on +the clothes line and it's- 20° C and + + align:start position:0% +the clothes line and it's- 20° C and + + + align:start position:0% +the clothes line and it's- 20° C and +first thing that happens is the water + + align:start position:0% +first thing that happens is the water + + + align:start position:0% +first thing that happens is the water +freezes but if you come back hours later + + align:start position:0% +freezes but if you come back hours later + + + align:start position:0% +freezes but if you come back hours later +the clothes are dry what happened did + + align:start position:0% +the clothes are dry what happened did + + + align:start position:0% +the clothes are dry what happened did +somebody come in truck grab all the + + align:start position:0% +somebody come in truck grab all the + + + align:start position:0% +somebody come in truck grab all the +clothes and take them down to the laundr + + align:start position:0% +clothes and take them down to the laundr + + + align:start position:0% +clothes and take them down to the laundr +mat put them into the dryer and then + + align:start position:0% +mat put them into the dryer and then + + + align:start position:0% +mat put them into the dryer and then +come back and hang them on the clothes + + align:start position:0% +come back and hang them on the clothes + + + align:start position:0% +come back and hang them on the clothes +line how did it happen happen went + + align:start position:0% +line how did it happen happen went + + + align:start position:0% +line how did it happen happen went +directly from solid to Vapor this is + + align:start position:0% +directly from solid to Vapor this is + + + align:start position:0% +directly from solid to Vapor this is +sublimation this is + + align:start position:0% +sublimation this is + + + align:start position:0% +sublimation this is +sublimation here liquid goes to Vapor is + + align:start position:0% +sublimation here liquid goes to Vapor is + + + align:start position:0% +sublimation here liquid goes to Vapor is +called + + align:start position:0% + + + + align:start position:0% + +evaporation Vapor goes to liquid is + + align:start position:0% + + + + align:start position:0% + +condensation these are the phase + + align:start position:0% +condensation these are the phase + + + align:start position:0% +condensation these are the phase +Transformations solid goes to liquid you + + align:start position:0% +Transformations solid goes to liquid you + + + align:start position:0% +Transformations solid goes to liquid you +know that's + + align:start position:0% +know that's + + + align:start position:0% +know that's +melting and liquid goes to solid that is + + align:start position:0% +melting and liquid goes to solid that is + + + align:start position:0% +melting and liquid goes to solid that is +solidification and I say that without + + align:start position:0% +solidification and I say that without + + + align:start position:0% +solidification and I say that without +prejudice it it could be to form the + + align:start position:0% +prejudice it it could be to form the + + + align:start position:0% +prejudice it it could be to form the +glassy solid or it could be to form + + align:start position:0% +glassy solid or it could be to form + + + align:start position:0% +glassy solid or it could be to form +the amorphous solid and sublimation + + align:start position:0% +the amorphous solid and sublimation + + + align:start position:0% +the amorphous solid and sublimation +talks about both directions Vapor to + + align:start position:0% +talks about both directions Vapor to + + + align:start position:0% +talks about both directions Vapor to +solid or solid to Vapor is + + align:start position:0% +solid or solid to Vapor is + + + align:start position:0% +solid or solid to Vapor is +sublimation so this is a coexistence + + align:start position:0% +sublimation so this is a coexistence + + + align:start position:0% +sublimation so this is a coexistence +curve so along here we can even put some + + align:start position:0% +curve so along here we can even put some + + + align:start position:0% +curve so along here we can even put some +labels we can put over here single phase + + align:start position:0% +labels we can put over here single phase + + + align:start position:0% +labels we can put over here single phase +over here single phase and over here + + align:start position:0% +over here single phase and over here + + + align:start position:0% +over here single phase and over here +single phase and along these coexistence + + align:start position:0% +single phase and along these coexistence + + + align:start position:0% +single phase and along these coexistence +curves liquid equals Vapor so I have two + + align:start position:0% +curves liquid equals Vapor so I have two + + + align:start position:0% +curves liquid equals Vapor so I have two +phases along all the coexistence + + align:start position:0% + + + + align:start position:0% + +curves along the coexistence curves look + + align:start position:0% +curves along the coexistence curves look + + + align:start position:0% +curves along the coexistence curves look +at this point here that's a curiosity + + align:start position:0% +at this point here that's a curiosity + + + align:start position:0% +at this point here that's a curiosity +isn't it what do I have here according + + align:start position:0% +isn't it what do I have here according + + + align:start position:0% +isn't it what do I have here according +to this diagram I have solid liquid and + + align:start position:0% +to this diagram I have solid liquid and + + + align:start position:0% +to this diagram I have solid liquid and +Vapor in + + align:start position:0% +Vapor in + + + align:start position:0% +Vapor in +equilibrium this + + align:start position:0% +equilibrium this + + + align:start position:0% +equilibrium this +is ice cubes in boiling water ice cubes + + align:start position:0% +is ice cubes in boiling water ice cubes + + + align:start position:0% +is ice cubes in boiling water ice cubes +and boiling water all three phases at + + align:start position:0% +and boiling water all three phases at + + + align:start position:0% +and boiling water all three phases at +this point here and this Point first of + + align:start position:0% +this point here and this Point first of + + + align:start position:0% +this point here and this Point first of +all as you can imagine not to scale + + align:start position:0% +all as you can imagine not to scale + + + align:start position:0% +all as you can imagine not to scale +because some of the features are rather + + align:start position:0% +because some of the features are rather + + + align:start position:0% +because some of the features are rather +subtle and wouldn't be seen if I drew + + align:start position:0% +subtle and wouldn't be seen if I drew + + + align:start position:0% +subtle and wouldn't be seen if I drew +this to scale this is at a very slight + + align:start position:0% +this to scale this is at a very slight + + + align:start position:0% +this to scale this is at a very slight +elevation in temperature it's about 1/ + + align:start position:0% +elevation in temperature it's about 1/ + + + align:start position:0% +elevation in temperature it's about 1/ +100th of a degree above Zer Celsius and + + align:start position:0% +100th of a degree above Zer Celsius and + + + align:start position:0% +100th of a degree above Zer Celsius and +the pressure here is about oh it's it's + + align:start position:0% +the pressure here is about oh it's it's + + + align:start position:0% +the pressure here is about oh it's it's +not about I know what it is it's 4.58 + + align:start position:0% +not about I know what it is it's 4.58 + + + align:start position:0% +not about I know what it is it's 4.58 +millimet I'm going to squeeze that in + + align:start position:0% +millimet I'm going to squeeze that in + + + align:start position:0% +millimet I'm going to squeeze that in +here it's + + align:start position:0% + + + + align:start position:0% + +4.58 millim of mercury and you need to + + align:start position:0% +4.58 millim of mercury and you need to + + + align:start position:0% +4.58 millim of mercury and you need to +know that one atmosphere if you remember + + align:start position:0% +know that one atmosphere if you remember + + + align:start position:0% +know that one atmosphere if you remember +torelli and his vacuum tube is 76 CM or + + align:start position:0% +torelli and his vacuum tube is 76 CM or + + + align:start position:0% +torelli and his vacuum tube is 76 CM or +760 millimet of mercury so that's the + + align:start position:0% +760 millimet of mercury so that's the + + + align:start position:0% +760 millimet of mercury so that's the +pressure it's 4.58 millim and so if you + + align:start position:0% +pressure it's 4.58 millim and so if you + + + align:start position:0% +pressure it's 4.58 millim and so if you +were to take water pour it into a beaker + + align:start position:0% +were to take water pour it into a beaker + + + align:start position:0% +were to take water pour it into a beaker +cover the beaker with a some enclosure + + align:start position:0% +cover the beaker with a some enclosure + + + align:start position:0% +cover the beaker with a some enclosure +that allowed you to pump the temperature + + align:start position:0% +that allowed you to pump the temperature + + + align:start position:0% +that allowed you to pump the temperature +down eventually you would reach excuse + + align:start position:0% +down eventually you would reach excuse + + + align:start position:0% +down eventually you would reach excuse +me pump the pressure down eventually you + + align:start position:0% +me pump the pressure down eventually you + + + align:start position:0% +me pump the pressure down eventually you +would reach the pressure at which + + align:start position:0% +would reach the pressure at which + + + align:start position:0% +would reach the pressure at which +water boils at room temperature water + + align:start position:0% +water boils at room temperature water + + + align:start position:0% +water boils at room temperature water +boils at room temperature remember this + + align:start position:0% +boils at room temperature remember this + + + align:start position:0% +boils at room temperature remember this +number 2020 2020 roughly 20° C 20 millim + + align:start position:0% +number 2020 2020 roughly 20° C 20 millim + + + align:start position:0% +number 2020 2020 roughly 20° C 20 millim +of mercury round numbers it's not + + align:start position:0% +of mercury round numbers it's not + + + align:start position:0% +of mercury round numbers it's not +exactly that but it's it's very close so + + align:start position:0% +exactly that but it's it's very close so + + + align:start position:0% +exactly that but it's it's very close so +if you get 20 millimet of mercury you'll + + align:start position:0% +if you get 20 millimet of mercury you'll + + + align:start position:0% +if you get 20 millimet of mercury you'll +have boiling water at room temperature + + align:start position:0% +have boiling water at room temperature + + + align:start position:0% +have boiling water at room temperature +but if you get down a z degrees see just + + align:start position:0% +but if you get down a z degrees see just + + + align:start position:0% +but if you get down a z degrees see just +100th of a degree higher you have all + + align:start position:0% +100th of a degree higher you have all + + + align:start position:0% +100th of a degree higher you have all +three phases ice cubes with water + + align:start position:0% +three phases ice cubes with water + + + align:start position:0% +three phases ice cubes with water +boiling in uh liquid so here we are with + + align:start position:0% +boiling in uh liquid so here we are with + + + align:start position:0% +boiling in uh liquid so here we are with +all of the + + align:start position:0% +all of the + + + align:start position:0% +all of the +all of the different phases and uh oh + + align:start position:0% +all of the different phases and uh oh + + + align:start position:0% +all of the different phases and uh oh +there's last thing I wanted to tell you + + align:start position:0% +there's last thing I wanted to tell you + + + align:start position:0% +there's last thing I wanted to tell you +last thing is you see this slope here + + align:start position:0% +last thing is you see this slope here + + + align:start position:0% +last thing is you see this slope here +see this slope it's negative slope and + + align:start position:0% +see this slope it's negative slope and + + + align:start position:0% +see this slope it's negative slope and +it it kind of puzzles me because when + + align:start position:0% +it it kind of puzzles me because when + + + align:start position:0% +it it kind of puzzles me because when +you look at it normally you'd think you + + align:start position:0% +you look at it normally you'd think you + + + align:start position:0% +you look at it normally you'd think you +see if you go at a at a a constant uh + + align:start position:0% +see if you go at a at a a constant uh + + + align:start position:0% +see if you go at a at a a constant uh +constant temperature let's say we start + + align:start position:0% +constant temperature let's say we start + + + align:start position:0% +constant temperature let's say we start +at 0 degrees and very very low pressure + + align:start position:0% +at 0 degrees and very very low pressure + + + align:start position:0% +at 0 degrees and very very low pressure +so we have something that's a gas and + + align:start position:0% +so we have something that's a gas and + + + align:start position:0% +so we have something that's a gas and +then we press atoms closer and closer + + align:start position:0% +then we press atoms closer and closer + + + align:start position:0% +then we press atoms closer and closer +together and then it says you make a + + align:start position:0% +together and then it says you make a + + + align:start position:0% +together and then it says you make a +solid and then at the constant + + align:start position:0% +solid and then at the constant + + + align:start position:0% +solid and then at the constant +temperature you press the solid atoms + + align:start position:0% +temperature you press the solid atoms + + + align:start position:0% +temperature you press the solid atoms +closer together and it says you make a + + align:start position:0% +closer together and it says you make a + + + align:start position:0% +closer together and it says you make a +liquid again doesn't that sound kind of + + align:start position:0% +liquid again doesn't that sound kind of + + + align:start position:0% +liquid again doesn't that sound kind of +backwards wouldn't you think that you + + align:start position:0% +backwards wouldn't you think that you + + + align:start position:0% +backwards wouldn't you think that you +start with gas atoms far apart then you + + align:start position:0% +start with gas atoms far apart then you + + + align:start position:0% +start with gas atoms far apart then you +move closer you get liquid atoms and you + + align:start position:0% +move closer you get liquid atoms and you + + + align:start position:0% +move closer you get liquid atoms and you +press the liquid atoms and you get a + + align:start position:0% +press the liquid atoms and you get a + + + align:start position:0% +press the liquid atoms and you get a +solid but water is special water is + + align:start position:0% +solid but water is special water is + + + align:start position:0% +solid but water is special water is +special because the bonding in the solid + + align:start position:0% +special because the bonding in the solid + + + align:start position:0% +special because the bonding in the solid +is more open than bonding in the liquid + + align:start position:0% +is more open than bonding in the liquid + + + align:start position:0% +is more open than bonding in the liquid +and I can look at this and say because + + align:start position:0% +and I can look at this and say because + + + align:start position:0% +and I can look at this and say because +when I press from solid to liquid liid + + align:start position:0% +when I press from solid to liquid liid + + + align:start position:0% +when I press from solid to liquid liid +this tells me that the density of the + + align:start position:0% +this tells me that the density of the + + + align:start position:0% +this tells me that the density of the +solid is lower than the density of the + + align:start position:0% +solid is lower than the density of the + + + align:start position:0% +solid is lower than the density of the +liquid I look at that and I say ice + + align:start position:0% +liquid I look at that and I say ice + + + align:start position:0% +liquid I look at that and I say ice +cubes float ice cubes float and there + + align:start position:0% +cubes float ice cubes float and there + + + align:start position:0% +cubes float ice cubes float and there +are other there are other uh systems for + + align:start position:0% +are other there are other uh systems for + + + align:start position:0% +are other there are other uh systems for +which the same happens uh here's silicon + + align:start position:0% +which the same happens uh here's silicon + + + align:start position:0% +which the same happens uh here's silicon +look at silicon here's the phase diagram + + align:start position:0% +look at silicon here's the phase diagram + + + align:start position:0% +look at silicon here's the phase diagram +for silicon pressure versus temperature + + align:start position:0% +for silicon pressure versus temperature + + + align:start position:0% +for silicon pressure versus temperature +you see uh uh down here it's FCC the + + align:start position:0% +you see uh uh down here it's FCC the + + + align:start position:0% +you see uh uh down here it's FCC the +diamond cubic structure and if we go + + align:start position:0% +diamond cubic structure and if we go + + + align:start position:0% +diamond cubic structure and if we go +there's the melting point of silicon we + + align:start position:0% +there's the melting point of silicon we + + + align:start position:0% +there's the melting point of silicon we +go to the liquid it's got more near its + + align:start position:0% +go to the liquid it's got more near its + + + align:start position:0% +go to the liquid it's got more near its +neighbor how many nearest neighbors does + + align:start position:0% +neighbor how many nearest neighbors does + + + align:start position:0% +neighbor how many nearest neighbors does +the solid have it's sp3 hybridized has + + align:start position:0% +the solid have it's sp3 hybridized has + + + align:start position:0% +the solid have it's sp3 hybridized has +four nearest neighbors most liquids have + + align:start position:0% +four nearest neighbors most liquids have + + + align:start position:0% +four nearest neighbors most liquids have +about six nearest neighbors so when you + + align:start position:0% +about six nearest neighbors so when you + + + align:start position:0% +about six nearest neighbors so when you +have these open structures like Silicon + + align:start position:0% +have these open structures like Silicon + + + align:start position:0% +have these open structures like Silicon +geranium the silicate glasses and + + align:start position:0% +geranium the silicate glasses and + + + align:start position:0% +geranium the silicate glasses and +Ice you actually go to a more condensed + + align:start position:0% +Ice you actually go to a more condensed + + + align:start position:0% +Ice you actually go to a more condensed +system when you first liquefy and this + + align:start position:0% +system when you first liquefy and this + + + align:start position:0% +system when you first liquefy and this +is how you skate by the way you know + + align:start position:0% +is how you skate by the way you know + + + align:start position:0% +is how you skate by the way you know +you're down here at one atmosphere about + + align:start position:0% +you're down here at one atmosphere about + + + align:start position:0% +you're down here at one atmosphere about +minus5 degrees C and you put your weight + + align:start position:0% +minus5 degrees C and you put your weight + + + align:start position:0% +minus5 degrees C and you put your weight +on the blades so that's a mass which + + align:start position:0% +on the blades so that's a mass which + + + align:start position:0% +on the blades so that's a mass which +then becomes a force on a small small + + align:start position:0% +then becomes a force on a small small + + + align:start position:0% +then becomes a force on a small small +area which becomes a pressure and then + + align:start position:0% +area which becomes a pressure and then + + + align:start position:0% +area which becomes a pressure and then +that allows you to cross this line so + + align:start position:0% +that allows you to cross this line so + + + align:start position:0% +that allows you to cross this line so +you glide on a thin film of water and if + + align:start position:0% +you glide on a thin film of water and if + + + align:start position:0% +you glide on a thin film of water and if +the temperature gets really cold if it's + + align:start position:0% +the temperature gets really cold if it's + + + align:start position:0% +the temperature gets really cold if it's +down here at around minus 20 and I've + + align:start position:0% +down here at around minus 20 and I've + + + align:start position:0% +down here at around minus 20 and I've +had the pleasure of skating when it's + + align:start position:0% +had the pleasure of skating when it's + + + align:start position:0% +had the pleasure of skating when it's +minus 20 my + + align:start position:0% +minus 20 my + + + align:start position:0% +minus 20 my +mass converted to appropriate pressure + + align:start position:0% +mass converted to appropriate pressure + + + align:start position:0% +mass converted to appropriate pressure +on the blades is not high enough to + + align:start position:0% +on the blades is not high enough to + + + align:start position:0% +on the blades is not high enough to +cross this line and the skating + + align:start position:0% +cross this line and the skating + + + align:start position:0% +cross this line and the skating +experience is very different because now + + align:start position:0% +experience is very different because now + + + align:start position:0% +experience is very different because now +it's just it's just steel blades on ice + + align:start position:0% +it's just it's just steel blades on ice + + + align:start position:0% +it's just it's just steel blades on ice +and it's you don't get traction to put + + align:start position:0% +and it's you don't get traction to put + + + align:start position:0% +and it's you don't get traction to put +it simply you fall okay you fall not + + align:start position:0% +it simply you fall okay you fall not + + + align:start position:0% +it simply you fall okay you fall not +good not good okay so let's let's look + + align:start position:0% +good not good okay so let's let's look + + + align:start position:0% +good not good okay so let's let's look +at a few others if we contrast here this + + align:start position:0% +at a few others if we contrast here this + + + align:start position:0% +at a few others if we contrast here this +is aluminum a simple FCC metal and what + + align:start position:0% +is aluminum a simple FCC metal and what + + + align:start position:0% +is aluminum a simple FCC metal and what +we see with aluminum in this case it's + + align:start position:0% +we see with aluminum in this case it's + + + align:start position:0% +we see with aluminum in this case it's +normal liquid has about six to eight + + align:start position:0% +normal liquid has about six to eight + + + align:start position:0% +normal liquid has about six to eight +nearest neighbors and the solid has 12 + + align:start position:0% +nearest neighbors and the solid has 12 + + + align:start position:0% +nearest neighbors and the solid has 12 +nearest neighbors so the solid is denser + + align:start position:0% +nearest neighbors so the solid is denser + + + align:start position:0% +nearest neighbors so the solid is denser +than the liquid and you see that in the + + align:start position:0% +than the liquid and you see that in the + + + align:start position:0% +than the liquid and you see that in the +face diagram here's nitrogen nitrogen is + + align:start position:0% +face diagram here's nitrogen nitrogen is + + + align:start position:0% +face diagram here's nitrogen nitrogen is +uh let's see what do we have it's at 1 + + align:start position:0% +uh let's see what do we have it's at 1 + + + align:start position:0% +uh let's see what do we have it's at 1 +atmosphere pressure its U uh melting + + align:start position:0% +atmosphere pressure its U uh melting + + + align:start position:0% +atmosphere pressure its U uh melting +point is 63 Kelvin its boiling point is + + align:start position:0% +point is 63 Kelvin its boiling point is + + + align:start position:0% +point is 63 Kelvin its boiling point is +77 Kelvin you remember that because MIT + + align:start position:0% +77 Kelvin you remember that because MIT + + + align:start position:0% +77 Kelvin you remember that because MIT +is 77 Mass AB so nitrogen boils at 77 + + align:start position:0% +is 77 Mass AB so nitrogen boils at 77 + + + align:start position:0% +is 77 Mass AB so nitrogen boils at 77 +Kelvin and the triple point is down here + + align:start position:0% +Kelvin and the triple point is down here + + + align:start position:0% +Kelvin and the triple point is down here +it's it's about 100 of a degree below + + align:start position:0% +it's it's about 100 of a degree below + + + align:start position:0% +it's it's about 100 of a degree below +and it turns out it's about an eighth of + + align:start position:0% +and it turns out it's about an eighth of + + + align:start position:0% +and it turns out it's about an eighth of +an atmosphere pressure this is the + + align:start position:0% +an atmosphere pressure this is the + + + align:start position:0% +an atmosphere pressure this is the +triple point of nitrogen ice in boiling + + align:start position:0% +triple point of nitrogen ice in boiling + + + align:start position:0% +triple point of nitrogen ice in boiling +liquid nitrogen but this has a positive + + align:start position:0% +liquid nitrogen but this has a positive + + + align:start position:0% +liquid nitrogen but this has a positive +slope so this means that the solid + + align:start position:0% +slope so this means that the solid + + + align:start position:0% +slope so this means that the solid +nitrogen ice sinks to the bottom of the + + align:start position:0% +nitrogen ice sinks to the bottom of the + + + align:start position:0% +nitrogen ice sinks to the bottom of the +liquid nitrogen and I thought since it's + + align:start position:0% +liquid nitrogen and I thought since it's + + + align:start position:0% +liquid nitrogen and I thought since it's +Friday maybe we could have just a little + + align:start position:0% +Friday maybe we could have just a little + + + align:start position:0% +Friday maybe we could have just a little +bit of fun here with the liquid nitrogen + + align:start position:0% +bit of fun here with the liquid nitrogen + + + align:start position:0% +bit of fun here with the liquid nitrogen +so I'm going to get dressed first I have + + align:start position:0% +so I'm going to get dressed first I have + + + align:start position:0% +so I'm going to get dressed first I have +to practice safe science I have to set + + align:start position:0% +to practice safe science I have to set + + + align:start position:0% +to practice safe science I have to set +an example for you you see I this year + + align:start position:0% +an example for you you see I this year + + + align:start position:0% +an example for you you see I this year +one of my uh staff Patrick trappa said + + align:start position:0% +one of my uh staff Patrick trappa said + + + align:start position:0% +one of my uh staff Patrick trappa said +why don't you wear a lab coat so I said + + align:start position:0% +why don't you wear a lab coat so I said + + + align:start position:0% +why don't you wear a lab coat so I said +okay try to try to do this + + align:start position:0% +okay try to try to do this + + + align:start position:0% +okay try to try to do this +properly is what which which design + + align:start position:0% +properly is what which which design + + + align:start position:0% +properly is what which which design +house did you go to for this + + align:start position:0% +house did you go to for this + + + align:start position:0% +house did you go to for this +Valentino + + align:start position:0% +Valentino + + + align:start position:0% +Valentino +vers okay so what are we going to do oh + + align:start position:0% +vers okay so what are we going to do oh + + + align:start position:0% +vers okay so what are we going to do oh +we're going to get some nitrogen let's + + align:start position:0% +we're going to get some nitrogen let's + + + align:start position:0% +we're going to get some nitrogen let's +get some nitrogen we'll have some fun + + align:start position:0% +get some nitrogen we'll have some fun + + + align:start position:0% +get some nitrogen we'll have some fun +with so we're going to be working at 77 + + align:start position:0% +with so we're going to be working at 77 + + + align:start position:0% +with so we're going to be working at 77 +Kelvin and for those of you in the back + + align:start position:0% +Kelvin and for those of you in the back + + + align:start position:0% +Kelvin and for those of you in the back +we're going to put this up on the + + align:start position:0% +we're going to put this up on the + + + align:start position:0% +we're going to put this up on the +monitors oh no food in the laboratory so + + align:start position:0% +monitors oh no food in the laboratory so + + + align:start position:0% +monitors oh no food in the laboratory so +let's put that over + + align:start position:0% +let's put that over + + + align:start position:0% +let's put that over +there okay let's pour a little bit of + + align:start position:0% +there okay let's pour a little bit of + + + align:start position:0% +there okay let's pour a little bit of +this + + align:start position:0% + + + + align:start position:0% + +out ah + + align:start position:0% + + + + align:start position:0% + +fantastic okay + + align:start position:0% +fantastic okay + + + align:start position:0% +fantastic okay +so see what are we going to so uh first + + align:start position:0% +so see what are we going to so uh first + + + align:start position:0% +so see what are we going to so uh first +thing we'll do is uh let's let's look at + + align:start position:0% +thing we'll do is uh let's let's look at + + + align:start position:0% +thing we'll do is uh let's let's look at +glass transition temperature so I have + + align:start position:0% +glass transition temperature so I have + + + align:start position:0% +glass transition temperature so I have +some uh rubber gloves oh I have to face + + align:start position:0% +some uh rubber gloves oh I have to face + + + align:start position:0% +some uh rubber gloves oh I have to face +uh Craig over this way okay Craig I'm + + align:start position:0% +uh Craig over this way okay Craig I'm + + + align:start position:0% +uh Craig over this way okay Craig I'm +going to do it this so here's some + + align:start position:0% +going to do it this so here's some + + + align:start position:0% +going to do it this so here's some +rubber gloves and so you know you can + + align:start position:0% +rubber gloves and so you know you can + + + align:start position:0% +rubber gloves and so you know you can +hear that they're they're acting elastic + + align:start position:0% +hear that they're they're acting elastic + + + align:start position:0% +hear that they're they're acting elastic +they're above their TG so this is just + + align:start position:0% +they're above their TG so this is just + + + align:start position:0% +they're above their TG so this is just +the calent bonds and what I'm going to + + align:start position:0% +the calent bonds and what I'm going to + + + align:start position:0% +the calent bonds and what I'm going to +do is pour a little bit of nitrogen in + + align:start position:0% +do is pour a little bit of nitrogen in + + + align:start position:0% +do is pour a little bit of nitrogen in +here + + align:start position:0% + + + + align:start position:0% + +I don't know if you noticed but the + + align:start position:0% +I don't know if you noticed but the + + + align:start position:0% +I don't know if you noticed but the +these gloves are chyal just just in case + + align:start position:0% +these gloves are chyal just just in case + + + align:start position:0% +these gloves are chyal just just in case +you notice I chose CYO + + align:start position:0% +you notice I chose CYO + + + align:start position:0% +you notice I chose CYO +gloves okay so now see so they're below + + align:start position:0% +gloves okay so now see so they're below + + + align:start position:0% +gloves okay so now see so they're below +the glass transition temperature I'm + + align:start position:0% +the glass transition temperature I'm + + + align:start position:0% +the glass transition temperature I'm +sorry Craig I got to here you get that + + align:start position:0% +sorry Craig I got to here you get that + + + align:start position:0% +sorry Craig I got to here you get that +we'll do it one more time okay gone + + align:start position:0% +we'll do it one more time okay gone + + + align:start position:0% +we'll do it one more time okay gone +glass transition temperature also if you + + align:start position:0% +glass transition temperature also if you + + + align:start position:0% +glass transition temperature also if you +wanted to drill the uh um if you wanted + + align:start position:0% +wanted to drill the uh um if you wanted + + + align:start position:0% +wanted to drill the uh um if you wanted +to drill the rubber stopper of course + + align:start position:0% +to drill the rubber stopper of course + + + align:start position:0% +to drill the rubber stopper of course +now you can hear I got to keep doing it + + align:start position:0% +now you can hear I got to keep doing it + + + align:start position:0% +now you can hear I got to keep doing it +this side + + align:start position:0% +this side + + + align:start position:0% +this side +so you can hear that it's it's rubbery + + align:start position:0% +so you can hear that it's it's rubbery + + + align:start position:0% +so you can hear that it's it's rubbery +I'm going to drop it in there let it + + align:start position:0% +I'm going to drop it in there let it + + + align:start position:0% +I'm going to drop it in there let it +mind its own business oh Saran Wrap it's + + align:start position:0% +mind its own business oh Saran Wrap it's + + + align:start position:0% +mind its own business oh Saran Wrap it's +also got glass transition temperature so + + align:start position:0% +also got glass transition temperature so + + + align:start position:0% +also got glass transition temperature so +we can show that getting it into liquid + + align:start position:0% + + + + align:start position:0% + +nitrogen Okay so + + align:start position:0% + + + + align:start position:0% + +you hear how it's flexible now what + + align:start position:0% +you hear how it's flexible now what + + + align:start position:0% +you hear how it's flexible now what +we'll do is we'll put that in + + align:start position:0% +we'll do is we'll put that in + + + align:start position:0% +we'll do is we'll put that in +there okay now you can hear how it + + align:start position:0% +there okay now you can hear how it + + + align:start position:0% +there okay now you can hear how it +changes it's below the glass + + align:start position:0% +changes it's below the glass + + + align:start position:0% +changes it's below the glass +transition I should have been wearing + + align:start position:0% +transition I should have been wearing + + + align:start position:0% +transition I should have been wearing +gloves and all that but you know + + align:start position:0% +gloves and all that but you know + + + align:start position:0% +gloves and all that but you know +forget okay how about protein oh you + + align:start position:0% +forget okay how about protein oh you + + + align:start position:0% +forget okay how about protein oh you +know the other thing we can do other + + align:start position:0% +know the other thing we can do other + + + align:start position:0% +know the other thing we can do other +thing we can do is I want to make some + + align:start position:0% +thing we can do is I want to make some + + + align:start position:0% +thing we can do is I want to make some +liquid oxygen so I don't know can we + + align:start position:0% +liquid oxygen so I don't know can we + + + align:start position:0% +liquid oxygen so I don't know can we +just cut to the to the computer slide + + align:start position:0% +just cut to the to the computer slide + + + align:start position:0% +just cut to the to the computer slide +for a second I want to show people what + + align:start position:0% +for a second I want to show people what + + + align:start position:0% +for a second I want to show people what +we're going to do here with uh this next + + align:start position:0% +we're going to do here with uh this next + + + align:start position:0% +we're going to do here with uh this next +one all right so what I'm going to do is + + align:start position:0% +one all right so what I'm going to do is + + + align:start position:0% +one all right so what I'm going to do is +I'm going to put um a a graduated + + align:start position:0% +I'm going to put um a a graduated + + + align:start position:0% +I'm going to put um a a graduated +cylinder inside fill this with liquid + + align:start position:0% +cylinder inside fill this with liquid + + + align:start position:0% +cylinder inside fill this with liquid +nitrogen and these are the boiling + + align:start position:0% +nitrogen and these are the boiling + + + align:start position:0% +nitrogen and these are the boiling +points of oxygen argon and nitrogen and + + align:start position:0% +points of oxygen argon and nitrogen and + + + align:start position:0% +points of oxygen argon and nitrogen and +nitrogen is at 77 so this is all 77 + + align:start position:0% +nitrogen is at 77 so this is all 77 + + + align:start position:0% +nitrogen is at 77 so this is all 77 +Kelvin but oxygen uh condenses at 90 so + + align:start position:0% +Kelvin but oxygen uh condenses at 90 so + + + align:start position:0% +Kelvin but oxygen uh condenses at 90 so +we're going to make liquid oxygen with a + + align:start position:0% +we're going to make liquid oxygen with a + + + align:start position:0% +we're going to make liquid oxygen with a +little bit of argon ice I'm just going + + align:start position:0% +little bit of argon ice I'm just going + + + align:start position:0% +little bit of argon ice I'm just going +to let it sit there for the balance of + + align:start position:0% +to let it sit there for the balance of + + + align:start position:0% +to let it sit there for the balance of +the lecture and maybe at the end we'll + + align:start position:0% +the lecture and maybe at the end we'll + + + align:start position:0% +the lecture and maybe at the end we'll +see some of the uh liquid oxygen so so + + align:start position:0% +see some of the uh liquid oxygen so so + + + align:start position:0% +see some of the uh liquid oxygen so so +let's just pour + + align:start position:0% + + + + align:start position:0% + +that okay so we'll let that work and uh + + align:start position:0% +that okay so we'll let that work and uh + + + align:start position:0% +that okay so we'll let that work and uh +oh yeah how about proteins we said they + + align:start position:0% +oh yeah how about proteins we said they + + + align:start position:0% +oh yeah how about proteins we said they +were polymers so let's see if we can do + + align:start position:0% +were polymers so let's see if we can do + + + align:start position:0% +were polymers so let's see if we can do +something with the with the proteins + + align:start position:0% +something with the with the proteins + + + align:start position:0% +something with the with the proteins +here oh yeah we're going to put the + + align:start position:0% +here oh yeah we're going to put the + + + align:start position:0% +here oh yeah we're going to put the +roses in you know they have glass + + align:start position:0% +roses in you know they have glass + + + align:start position:0% +roses in you know they have glass +flowers at Harvard at the at the Museum + + align:start position:0% +flowers at Harvard at the at the Museum + + + align:start position:0% +flowers at Harvard at the at the Museum +fog Museum we have glass flowers here at + + align:start position:0% +fog Museum we have glass flowers here at + + + align:start position:0% +fog Museum we have glass flowers here at +MIT see this okay so this is a rose you + + align:start position:0% +MIT see this okay so this is a rose you + + + align:start position:0% +MIT see this okay so this is a rose you +know it's very soft just nice think + + align:start position:0% +know it's very soft just nice think + + + align:start position:0% +know it's very soft just nice think +watch this okay let's + + align:start position:0% + + + + align:start position:0% + +go it's not a kitten come + + align:start position:0% +go it's not a kitten come + + + align:start position:0% +go it's not a kitten come +on maybe it only works on roses maybe we + + align:start position:0% +on maybe it only works on roses maybe we + + + align:start position:0% +on maybe it only works on roses maybe we +should do one more it's got to be a + + align:start position:0% +should do one more it's got to be a + + + align:start position:0% +should do one more it's got to be a +scientist you don't know maybe it's just + + align:start position:0% +scientist you don't know maybe it's just + + + align:start position:0% +scientist you don't know maybe it's just +roses that do this so let's look at this + + align:start position:0% + + + + align:start position:0% + +one glass transition temperature there + + align:start position:0% +one glass transition temperature there + + + align:start position:0% +one glass transition temperature there +it is okay so we got that going we'll + + align:start position:0% +it is okay so we got that going we'll + + + align:start position:0% +it is okay so we got that going we'll +let the oxygen uh condense and let's see + + align:start position:0% +let the oxygen uh condense and let's see + + + align:start position:0% +let the oxygen uh condense and let's see +let's go back to the computer I think + + align:start position:0% +let's go back to the computer I think + + + align:start position:0% +let's go back to the computer I think +we're going to take a break and go back + + align:start position:0% +we're going to take a break and go back + + + align:start position:0% +we're going to take a break and go back +to some some more learning here ah a a + + align:start position:0% +to some some more learning here ah a a + + + align:start position:0% +to some some more learning here ah a a +ah yeah + + align:start position:0% +ah yeah + + + align:start position:0% +ah yeah +okay so here here are some uh hang on + + align:start position:0% +okay so here here are some uh hang on + + + align:start position:0% +okay so here here are some uh hang on +there's one other one here I think got + + align:start position:0% +there's one other one here I think got + + + align:start position:0% +there's one other one here I think got +out of here all right so we've seen this + + align:start position:0% +out of here all right so we've seen this + + + align:start position:0% +out of here all right so we've seen this +one here's nitrogen with all of its + + align:start position:0% +one here's nitrogen with all of its + + + align:start position:0% +one here's nitrogen with all of its +different uh solid phases nitrogen + + align:start position:0% +different uh solid phases nitrogen + + + align:start position:0% +different uh solid phases nitrogen +actually has different Crystal + + align:start position:0% +actually has different Crystal + + + align:start position:0% +actually has different Crystal +structures and so this diagram shows + + align:start position:0% +structures and so this diagram shows + + + align:start position:0% +structures and so this diagram shows +what's going on as you as you change + + align:start position:0% +what's going on as you as you change + + + align:start position:0% +what's going on as you as you change +pressure at constant temperature here we + + align:start position:0% +pressure at constant temperature here we + + + align:start position:0% +pressure at constant temperature here we +are still down around minus uh 70 Kelvin + + align:start position:0% +are still down around minus uh 70 Kelvin + + + align:start position:0% +are still down around minus uh 70 Kelvin +so there we go from liquid to solid it's + + align:start position:0% +so there we go from liquid to solid it's + + + align:start position:0% +so there we go from liquid to solid it's +hcp and then it becomes simple cubic and + + align:start position:0% +hcp and then it becomes simple cubic and + + + align:start position:0% +hcp and then it becomes simple cubic and +then romic and so on so this property + + align:start position:0% +then romic and so on so this property + + + align:start position:0% +then romic and so on so this property +certain elements have multiple different + + align:start position:0% +certain elements have multiple different + + + align:start position:0% +certain elements have multiple different +um composition excuse me multiple + + align:start position:0% +um composition excuse me multiple + + + align:start position:0% +um composition excuse me multiple +different Crystal structures is called + + align:start position:0% +different Crystal structures is called + + + align:start position:0% +different Crystal structures is called +polymorphism so these are called + + align:start position:0% +polymorphism so these are called + + + align:start position:0% +polymorphism so these are called +different polymorphs you've already + + align:start position:0% +different polymorphs you've already + + + align:start position:0% +different polymorphs you've already +heard that uh iron has in some instances + + align:start position:0% +heard that uh iron has in some instances + + + align:start position:0% +heard that uh iron has in some instances +BCC crystal structure and FCC crystal + + align:start position:0% +BCC crystal structure and FCC crystal + + + align:start position:0% +BCC crystal structure and FCC crystal +structure and the phase diagrams will + + align:start position:0% +structure and the phase diagrams will + + + align:start position:0% +structure and the phase diagrams will +reveal when these transitions occur + + align:start position:0% +reveal when these transitions occur + + + align:start position:0% +reveal when these transitions occur +here's carbon dioxide solid liquid gas + + align:start position:0% +here's carbon dioxide solid liquid gas + + + align:start position:0% +here's carbon dioxide solid liquid gas +it's got a positive slope what's + + align:start position:0% +it's got a positive slope what's + + + align:start position:0% +it's got a positive slope what's +interesting about carbon dioxide is look + + align:start position:0% +interesting about carbon dioxide is look + + + align:start position:0% +interesting about carbon dioxide is look +here the one atmosphere isobar takes you + + align:start position:0% +here the one atmosphere isobar takes you + + + align:start position:0% +here the one atmosphere isobar takes you +directly from solid to gas so it doesn't + + align:start position:0% +directly from solid to gas so it doesn't + + + align:start position:0% +directly from solid to gas so it doesn't +go liquid and that gives it value as a a + + align:start position:0% +go liquid and that gives it value as a a + + + align:start position:0% +go liquid and that gives it value as a a +as a refrigerant because when it uh + + align:start position:0% +as a refrigerant because when it uh + + + align:start position:0% +as a refrigerant because when it uh +gives up its uh enthalpy of uh of + + align:start position:0% +gives up its uh enthalpy of uh of + + + align:start position:0% +gives up its uh enthalpy of uh of +transformation you don't end up with a + + align:start position:0% +transformation you don't end up with a + + + align:start position:0% +transformation you don't end up with a +liquid which can mess up your contents + + align:start position:0% +liquid which can mess up your contents + + + align:start position:0% +liquid which can mess up your contents +and so this is often used in U in + + align:start position:0% +and so this is often used in U in + + + align:start position:0% +and so this is often used in U in +shipping certain materials so we've got + + align:start position:0% +shipping certain materials so we've got + + + align:start position:0% +shipping certain materials so we've got +some here let's play with some dry ice + + align:start position:0% +some here let's play with some dry ice + + + align:start position:0% +some here let's play with some dry ice +there's a great big ice cube here but + + align:start position:0% +there's a great big ice cube here but + + + align:start position:0% +there's a great big ice cube here but +there's some that's already broken off + + align:start position:0% +there's some that's already broken off + + + align:start position:0% +there's some that's already broken off +see so this uh I okay so here we are + + align:start position:0% +see so this uh I okay so here we are + + + align:start position:0% +see so this uh I okay so here we are +this is the big ice cube I guess Craig + + align:start position:0% +this is the big ice cube I guess Craig + + + align:start position:0% +this is the big ice cube I guess Craig +is going to want to see this so let's + + align:start position:0% +is going to want to see this so let's + + + align:start position:0% +is going to want to see this so let's +let's let Craig and the people watch the + + align:start position:0% +let's let Craig and the people watch the + + + align:start position:0% +let's let Craig and the people watch the +video This what I call an ice + + align:start position:0% + + + + align:start position:0% + +cube okay now this is at uh at minus 78° + + align:start position:0% +cube okay now this is at uh at minus 78° + + + align:start position:0% +cube okay now this is at uh at minus 78° +C and so it's it can go directly you're + + align:start position:0% +C and so it's it can go directly you're + + + align:start position:0% +C and so it's it can go directly you're +seeing it it's Sublime um let's see we + + align:start position:0% +seeing it it's Sublime um let's see we + + + align:start position:0% +seeing it it's Sublime um let's see we +can do some things just to prove let's + + align:start position:0% +can do some things just to prove let's + + + align:start position:0% +can do some things just to prove let's +prove that it's going directly from + + align:start position:0% +prove that it's going directly from + + + align:start position:0% +prove that it's going directly from +solid to uh gas so I have some just some + + align:start position:0% +solid to uh gas so I have some just some + + + align:start position:0% +solid to uh gas so I have some just some +plain spring water here non-carbonated + + align:start position:0% +plain spring water here non-carbonated + + + align:start position:0% +plain spring water here non-carbonated +this is flat okay so this is flat I'll + + align:start position:0% +this is flat okay so this is flat I'll + + + align:start position:0% +this is flat okay so this is flat I'll +put that on the edge there for Craig and + + align:start position:0% +put that on the edge there for Craig and + + + align:start position:0% +put that on the edge there for Craig and +then just to show that we're going + + align:start position:0% +then just to show that we're going + + + align:start position:0% +then just to show that we're going +directly I take + + align:start position:0% + + + + align:start position:0% + +this okay see I'll hold still Craig so + + align:start position:0% +this okay see I'll hold still Craig so + + + align:start position:0% +this okay see I'll hold still Craig so +there we go you see the bubbles coming + + align:start position:0% +there we go you see the bubbles coming + + + align:start position:0% +there we go you see the bubbles coming +off giant bubbles + + align:start position:0% +off giant bubbles + + + align:start position:0% +off giant bubbles +see so we're making CO2 in water and + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +uh this is + + align:start position:0% + + + + align:start position:0% + +good I want you to notice something you + + align:start position:0% +good I want you to notice something you + + + align:start position:0% +good I want you to notice something you +know you can buy this bottled WI + + align:start position:0% +know you can buy this bottled WI + + + align:start position:0% +know you can buy this bottled WI +and I don't know if you can see Craig I + + align:start position:0% +and I don't know if you can see Craig I + + + align:start position:0% +and I don't know if you can see Craig I +don't know if you can catch this but you + + align:start position:0% +don't know if you can catch this but you + + + align:start position:0% +don't know if you can catch this but you +see they have these tiny wimpy bubbles + + align:start position:0% +see they have these tiny wimpy bubbles + + + align:start position:0% +see they have these tiny wimpy bubbles +we have big + + align:start position:0% +we have big + + + align:start position:0% +we have big +bubbles we have big + + align:start position:0% +bubbles we have big + + + align:start position:0% +bubbles we have big +bubbles so that's + + align:start position:0% +bubbles so that's + + + align:start position:0% +bubbles so that's +CO2 let's see what else have we got + + align:start position:0% +CO2 let's see what else have we got + + + align:start position:0% +CO2 let's see what else have we got +going let's see if we still have some uh + + align:start position:0% +going let's see if we still have some uh + + + align:start position:0% +going let's see if we still have some uh +uh liquid we've made any liquid oxygen + + align:start position:0% +uh liquid we've made any liquid oxygen + + + align:start position:0% +uh liquid we've made any liquid oxygen +yet oh yeah there's just a little bit he + + align:start position:0% +yet oh yeah there's just a little bit he + + + align:start position:0% +yet oh yeah there's just a little bit he +won't be able to pick it up on the + + align:start position:0% +won't be able to pick it up on the + + + align:start position:0% +won't be able to pick it up on the +camera okay so now the the last thing I + + align:start position:0% +camera okay so now the the last thing I + + + align:start position:0% +camera okay so now the the last thing I +want to do is to go back to the um + + align:start position:0% +want to do is to go back to the um + + + align:start position:0% +want to do is to go back to the um +computer image if we could + + align:start position:0% +computer image if we could + + + align:start position:0% +computer image if we could +please Okay so we've got carbon dioxide + + align:start position:0% +please Okay so we've got carbon dioxide + + + align:start position:0% +please Okay so we've got carbon dioxide +all right here's a couple other phase + + align:start position:0% +all right here's a couple other phase + + + align:start position:0% +all right here's a couple other phase +diagrams zonia I mentioned to you that + + align:start position:0% +diagrams zonia I mentioned to you that + + + align:start position:0% +diagrams zonia I mentioned to you that +zerconia uh this is just pure zerconia + + align:start position:0% +zerconia uh this is just pure zerconia + + + align:start position:0% +zerconia uh this is just pure zerconia +zro2 and what do we find cubic is the + + align:start position:0% +zro2 and what do we find cubic is the + + + align:start position:0% +zro2 and what do we find cubic is the +form that gives you that faux Diamond + + align:start position:0% +form that gives you that faux Diamond + + + align:start position:0% +form that gives you that faux Diamond +but look it's stable only above about + + align:start position:0% +but look it's stable only above about + + + align:start position:0% +but look it's stable only above about +2,000 degre C so if you're going to give + + align:start position:0% +2,000 degre C so if you're going to give + + + align:start position:0% +2,000 degre C so if you're going to give +your sweetheart that uh that faux + + align:start position:0% +your sweetheart that uh that faux + + + align:start position:0% +your sweetheart that uh that faux +Diamond that's going to be too hot it's + + align:start position:0% +Diamond that's going to be too hot it's + + + align:start position:0% +Diamond that's going to be too hot it's +too hot so what we're going to learn + + align:start position:0% +too hot so what we're going to learn + + + align:start position:0% +too hot so what we're going to learn +next day is how to to open up this range + + align:start position:0% +next day is how to to open up this range + + + align:start position:0% +next day is how to to open up this range +of stability the way we opened up the + + align:start position:0% +of stability the way we opened up the + + + align:start position:0% +of stability the way we opened up the +range of liquid stability by adding + + align:start position:0% +range of liquid stability by adding + + + align:start position:0% +range of liquid stability by adding +ethylene glycol to water and see if we + + align:start position:0% +ethylene glycol to water and see if we + + + align:start position:0% +ethylene glycol to water and see if we +can get cubic zirconia stable down to + + align:start position:0% +can get cubic zirconia stable down to + + + align:start position:0% +can get cubic zirconia stable down to +room temperature right but normally it's + + align:start position:0% +room temperature right but normally it's + + + align:start position:0% +room temperature right but normally it's +monoc Clinic then it goes tetragonal It + + align:start position:0% +monoc Clinic then it goes tetragonal It + + + align:start position:0% +monoc Clinic then it goes tetragonal It +goes cubic and it goes liquid and so on + + align:start position:0% +goes cubic and it goes liquid and so on + + + align:start position:0% +goes cubic and it goes liquid and so on +then it even goes Vapor here's carbon at + + align:start position:0% +then it even goes Vapor here's carbon at + + + align:start position:0% +then it even goes Vapor here's carbon at +room temperature over a wide range of + + align:start position:0% +room temperature over a wide range of + + + align:start position:0% +room temperature over a wide range of +pressure is graphite hexagonal close + + align:start position:0% +pressure is graphite hexagonal close + + + align:start position:0% +pressure is graphite hexagonal close +pack then an elevated pressure it + + align:start position:0% +pack then an elevated pressure it + + + align:start position:0% +pack then an elevated pressure it +becomes diamond and here's liquid carbon + + align:start position:0% +becomes diamond and here's liquid carbon + + + align:start position:0% +becomes diamond and here's liquid carbon +it turns out that by judicious choice of + + align:start position:0% +it turns out that by judicious choice of + + + align:start position:0% +it turns out that by judicious choice of +chemistry people at General Electric + + align:start position:0% +chemistry people at General Electric + + + align:start position:0% +chemistry people at General Electric +about 30 years ago reasoned that steel + + align:start position:0% +about 30 years ago reasoned that steel + + + align:start position:0% +about 30 years ago reasoned that steel +consists of carbon and iron and if we + + align:start position:0% +consists of carbon and iron and if we + + + align:start position:0% +consists of carbon and iron and if we +quench steel we end up with carbon in + + align:start position:0% +quench steel we end up with carbon in + + + align:start position:0% +quench steel we end up with carbon in +the iron lattice if we put too much + + align:start position:0% +the iron lattice if we put too much + + + align:start position:0% +the iron lattice if we put too much +carbon the carbon will exsolve as + + align:start position:0% +carbon the carbon will exsolve as + + + align:start position:0% +carbon the carbon will exsolve as +precipitates well if we could exsolve at + + align:start position:0% +precipitates well if we could exsolve at + + + align:start position:0% +precipitates well if we could exsolve at +elevated pressure could we get the + + align:start position:0% +elevated pressure could we get the + + + align:start position:0% +elevated pressure could we get the +carbon to exsolve not as graphite but + + align:start position:0% +carbon to exsolve not as graphite but + + + align:start position:0% +carbon to exsolve not as graphite but +Diamond cubic and they did it they + + align:start position:0% +Diamond cubic and they did it they + + + align:start position:0% +Diamond cubic and they did it they +generated artificial diamonds and one of + + align:start position:0% +generated artificial diamonds and one of + + + align:start position:0% +generated artificial diamonds and one of +the leaders of the team was of course + + align:start position:0% +the leaders of the team was of course + + + align:start position:0% +the leaders of the team was of course +three Alum from MIT whom I met years + + align:start position:0% +three Alum from MIT whom I met years + + + align:start position:0% +three Alum from MIT whom I met years +later on a committee in um Washington in + + align:start position:0% +later on a committee in um Washington in + + + align:start position:0% +later on a committee in um Washington in +connection with the aluminum industry + + align:start position:0% +connection with the aluminum industry + + + align:start position:0% +connection with the aluminum industry +and he told me he was uh um in the team + + align:start position:0% +and he told me he was uh um in the team + + + align:start position:0% +and he told me he was uh um in the team +that went to London to negotiate with + + align:start position:0% +that went to London to negotiate with + + + align:start position:0% +that went to London to negotiate with +deur the big uh South African Diamond + + align:start position:0% +deur the big uh South African Diamond + + + align:start position:0% +deur the big uh South African Diamond +concern they were scared because General + + align:start position:0% +concern they were scared because General + + + align:start position:0% +concern they were scared because General +Electric reported that they could make + + align:start position:0% +Electric reported that they could make + + + align:start position:0% +Electric reported that they could make +artificial diamonds and they General + + align:start position:0% +artificial diamonds and they General + + + align:start position:0% +artificial diamonds and they General +Electric had reported that they could + + align:start position:0% +Electric had reported that they could + + + align:start position:0% +Electric had reported that they could +make large artificial diamonds well + + align:start position:0% +make large artificial diamonds well + + + align:start position:0% +make large artificial diamonds well +large they were trying to make diamond + + align:start position:0% +large they were trying to make diamond + + + align:start position:0% +large they were trying to make diamond +dust they actually had one that was + + align:start position:0% +dust they actually had one that was + + + align:start position:0% +dust they actually had one that was +about 1 millimeter it was Tiny But deers + + align:start position:0% +about 1 millimeter it was Tiny But deers + + + align:start position:0% +about 1 millimeter it was Tiny But deers +was was nervous and uh this is the + + align:start position:0% +was was nervous and uh this is the + + + align:start position:0% +was was nervous and uh this is the +fellow's name was Rod hanaman and he + + align:start position:0% +fellow's name was Rod hanaman and he + + + align:start position:0% +fellow's name was Rod hanaman and he +told me that the thing that scared him + + align:start position:0% +told me that the thing that scared him + + + align:start position:0% +told me that the thing that scared him +most was not sitting down with the Burrs + + align:start position:0% +most was not sitting down with the Burrs + + + align:start position:0% +most was not sitting down with the Burrs +because he had them bluffed the hardest + + align:start position:0% +because he had them bluffed the hardest + + + align:start position:0% +because he had them bluffed the hardest +thing was getting through uh British + + align:start position:0% +thing was getting through uh British + + + align:start position:0% +thing was getting through uh British +Customs because he had this on his + + align:start position:0% +Customs because he had this on his + + + align:start position:0% +Customs because he had this on his +person now if he opens up and they see + + align:start position:0% +person now if he opens up and they see + + + align:start position:0% +person now if he opens up and they see +all of this diamond material and + + align:start position:0% +all of this diamond material and + + + align:start position:0% +all of this diamond material and +remember artificial diamonds don't exist + + align:start position:0% +remember artificial diamonds don't exist + + + align:start position:0% +remember artificial diamonds don't exist +yet so he's going to tell the Customs + + align:start position:0% +yet so he's going to tell the Customs + + + align:start position:0% +yet so he's going to tell the Customs +agent well these are artificial diamonds + + align:start position:0% +agent well these are artificial diamonds + + + align:start position:0% +agent well these are artificial diamonds +I I don't think that's going to work + + align:start position:0% +I I don't think that's going to work + + + align:start position:0% +I I don't think that's going to work +it's there's always the you know what's + + align:start position:0% +it's there's always the you know what's + + + align:start position:0% +it's there's always the you know what's +it the early bird gets the worm but it's + + align:start position:0% +it the early bird gets the worm but it's + + + align:start position:0% +it the early bird gets the worm but it's +the second mouse that gets the cheese so + + align:start position:0% +the second mouse that gets the cheese so + + + align:start position:0% +the second mouse that gets the cheese so +you can be too early sometimes with that + + align:start position:0% +you can be too early sometimes with that + + + align:start position:0% +you can be too early sometimes with that +okay here's bisou here's bisou bismo has + + align:start position:0% +okay here's bisou here's bisou bismo has + + + align:start position:0% +okay here's bisou here's bisou bismo has +a lot of phases look at all the + + align:start position:0% +a lot of phases look at all the + + + align:start position:0% +a lot of phases look at all the +different phases of bismo and look at + + align:start position:0% +different phases of bismo and look at + + + align:start position:0% +different phases of bismo and look at +here what does this tell you about the + + align:start position:0% +here what does this tell you about the + + + align:start position:0% +here what does this tell you about the +solid bismo it will float in liquid + + align:start position:0% +solid bismo it will float in liquid + + + align:start position:0% +solid bismo it will float in liquid +bismuth and then if you go to high + + align:start position:0% +bismuth and then if you go to high + + + align:start position:0% +bismuth and then if you go to high +enough in pressure it compresses here's + + align:start position:0% +enough in pressure it compresses here's + + + align:start position:0% +enough in pressure it compresses here's +sulfur this sulfur is really one + + align:start position:0% +sulfur this sulfur is really one + + + align:start position:0% +sulfur this sulfur is really one +confused + + align:start position:0% +confused + + + align:start position:0% +confused +element look at all the solid phases + + align:start position:0% +element look at all the solid phases + + + align:start position:0% +element look at all the solid phases +look at all the liquid phases sulfur is + + align:start position:0% +look at all the liquid phases sulfur is + + + align:start position:0% +look at all the liquid phases sulfur is +one mess look it so it has allotropes + + align:start position:0% +one mess look it so it has allotropes + + + align:start position:0% +one mess look it so it has allotropes +allotropes are are different bonding + + align:start position:0% +allotropes are are different bonding + + + align:start position:0% +allotropes are are different bonding +forms for example oxygen and exist as + + align:start position:0% +forms for example oxygen and exist as + + + align:start position:0% +forms for example oxygen and exist as +atomic oxygen the molecular oxygen O2 + + align:start position:0% +atomic oxygen the molecular oxygen O2 + + + align:start position:0% +atomic oxygen the molecular oxygen O2 +and O3 which is Ozone so we say that O2 + + align:start position:0% +and O3 which is Ozone so we say that O2 + + + align:start position:0% +and O3 which is Ozone so we say that O2 +and O3 are both allotropes of oxygen + + align:start position:0% +and O3 are both allotropes of oxygen + + + align:start position:0% +and O3 are both allotropes of oxygen +well sulfur has 16 allotropes 16 it + + align:start position:0% +well sulfur has 16 allotropes 16 it + + + align:start position:0% +well sulfur has 16 allotropes 16 it +exists as discrete atoms as the dier + + align:start position:0% +exists as discrete atoms as the dier + + + align:start position:0% +exists as discrete atoms as the dier +this this hex exer the common solid form + + align:start position:0% +this this hex exer the common solid form + + + align:start position:0% +this this hex exer the common solid form +is this eight member uh circular linkage + + align:start position:0% +is this eight member uh circular linkage + + + align:start position:0% +is this eight member uh circular linkage +and then it polymerizes in the + + align:start position:0% +and then it polymerizes in the + + + align:start position:0% +and then it polymerizes in the +Melt so here's the low temperature room + + align:start position:0% +Melt so here's the low temperature room + + + align:start position:0% +Melt so here's the low temperature room +temperature sulfur is romic and at + + align:start position:0% +temperature sulfur is romic and at + + + align:start position:0% +temperature sulfur is romic and at +elevated temperature it goes monoclinic + + align:start position:0% +elevated temperature it goes monoclinic + + + align:start position:0% +elevated temperature it goes monoclinic +it's a solid solid phase transformation + + align:start position:0% +it's a solid solid phase transformation + + + align:start position:0% +it's a solid solid phase transformation +that's what you're seeing in that phase + + align:start position:0% +that's what you're seeing in that phase + + + align:start position:0% +that's what you're seeing in that phase +diagram when you you look back here + + align:start position:0% +diagram when you you look back here + + + align:start position:0% +diagram when you you look back here +that's what all this is there's the + + align:start position:0% +that's what all this is there's the + + + align:start position:0% +that's what all this is there's the +monoc clinic and then the the romic all + + align:start position:0% +monoc clinic and then the the romic all + + + align:start position:0% +monoc clinic and then the the romic all +right and then if you melt it + + align:start position:0% +right and then if you melt it + + + align:start position:0% +right and then if you melt it +um it first it gives the straw colored + + align:start position:0% +um it first it gives the straw colored + + + align:start position:0% +um it first it gives the straw colored +liquid which they call Lambda at 119° + + align:start position:0% +liquid which they call Lambda at 119° + + + align:start position:0% +liquid which they call Lambda at 119° +and around 160 this turns into the the + + align:start position:0% +and around 160 this turns into the the + + + align:start position:0% +and around 160 this turns into the the +Rings start to open up and it turns an + + align:start position:0% +Rings start to open up and it turns an + + + align:start position:0% +Rings start to open up and it turns an +orange color at 160 and then this is uh + + align:start position:0% +orange color at 160 and then this is uh + + + align:start position:0% +orange color at 160 and then this is uh +at some elevated temperature about 200° + + align:start position:0% +at some elevated temperature about 200° + + + align:start position:0% +at some elevated temperature about 200° +C they poured this long polymer sulfur + + align:start position:0% +C they poured this long polymer sulfur + + + align:start position:0% +C they poured this long polymer sulfur +goo into water quenching it and guess + + align:start position:0% +goo into water quenching it and guess + + + align:start position:0% +goo into water quenching it and guess +what you form you form a glass it's + + align:start position:0% +what you form you form a glass it's + + + align:start position:0% +what you form you form a glass it's +plastic sulfur so all of this is + + align:start position:0% +plastic sulfur so all of this is + + + align:start position:0% +plastic sulfur so all of this is +happening as a result of the the + + align:start position:0% +happening as a result of the the + + + align:start position:0% +happening as a result of the the +different phases that are present so + + align:start position:0% +different phases that are present so + + + align:start position:0% +different phases that are present so +this is forming plastic sulfur the last + + align:start position:0% +this is forming plastic sulfur the last + + + align:start position:0% +this is forming plastic sulfur the last +thing I want to tell you about is a this + + align:start position:0% +thing I want to tell you about is a this + + + align:start position:0% +thing I want to tell you about is a this +last phase super critical fluid which is + + align:start position:0% +last phase super critical fluid which is + + + align:start position:0% +last phase super critical fluid which is +a very high temperature high pressure + + align:start position:0% +a very high temperature high pressure + + + align:start position:0% +a very high temperature high pressure +phase where you can't tell a gas from a + + align:start position:0% +phase where you can't tell a gas from a + + + align:start position:0% +phase where you can't tell a gas from a +liquid you can think of it as a highly + + align:start position:0% +liquid you can think of it as a highly + + + align:start position:0% +liquid you can think of it as a highly +compressed gas or a highly rarified + + align:start position:0% +compressed gas or a highly rarified + + + align:start position:0% +compressed gas or a highly rarified +liquid the blondes get far enough apart + + align:start position:0% +liquid the blondes get far enough apart + + + align:start position:0% +liquid the blondes get far enough apart +that the liquid is behaving a little bit + + align:start position:0% +that the liquid is behaving a little bit + + + align:start position:0% +that the liquid is behaving a little bit +differently the solvation properties are + + align:start position:0% +differently the solvation properties are + + + align:start position:0% +differently the solvation properties are +those of a liquid but here's what + + align:start position:0% +those of a liquid but here's what + + + align:start position:0% +those of a liquid but here's what +happens in the supercritical fluid you + + align:start position:0% +happens in the supercritical fluid you + + + align:start position:0% +happens in the supercritical fluid you +have transport properties of a gas so + + align:start position:0% +have transport properties of a gas so + + + align:start position:0% +have transport properties of a gas so +you have something that's liquidlike in + + align:start position:0% +you have something that's liquidlike in + + + align:start position:0% +you have something that's liquidlike in +terms of its ability to solvate things + + align:start position:0% +terms of its ability to solvate things + + + align:start position:0% +terms of its ability to solvate things +but it has gas-like diffusivity gas-like + + align:start position:0% +but it has gas-like diffusivity gas-like + + + align:start position:0% +but it has gas-like diffusivity gas-like +viscosity and this is very very uh much + + align:start position:0% +viscosity and this is very very uh much + + + align:start position:0% +viscosity and this is very very uh much +in the U research agenda these days + + align:start position:0% +in the U research agenda these days + + + align:start position:0% +in the U research agenda these days +using supercritical fluids to attack + + align:start position:0% +using supercritical fluids to attack + + + align:start position:0% +using supercritical fluids to attack +things like um uh toxic waste and so on + + align:start position:0% +things like um uh toxic waste and so on + + + align:start position:0% +things like um uh toxic waste and so on +without having to resort to very + + align:start position:0% +without having to resort to very + + + align:start position:0% +without having to resort to very +aggressive solvents it's no sense going + + align:start position:0% +aggressive solvents it's no sense going + + + align:start position:0% +aggressive solvents it's no sense going +after aggressive toxins when you have to + + align:start position:0% +after aggressive toxins when you have to + + + align:start position:0% +after aggressive toxins when you have to +use aggressive organic solvents but this + + align:start position:0% +use aggressive organic solvents but this + + + align:start position:0% +use aggressive organic solvents but this +will give you something of low polarity + + align:start position:0% +will give you something of low polarity + + + align:start position:0% +will give you something of low polarity +dissolving non-polar things and here's + + align:start position:0% +dissolving non-polar things and here's + + + align:start position:0% +dissolving non-polar things and here's +one that you you use more often than you + + align:start position:0% +one that you you use more often than you + + + align:start position:0% +one that you you use more often than you +know uh decaffeinating coffee uses + + align:start position:0% +know uh decaffeinating coffee uses + + + align:start position:0% +know uh decaffeinating coffee uses +solvent extraction when I was your age + + align:start position:0% +solvent extraction when I was your age + + + align:start position:0% +solvent extraction when I was your age +they actually used this stuff called + + align:start position:0% +they actually used this stuff called + + + align:start position:0% +they actually used this stuff called +methylene chloride I subsequently used + + align:start position:0% +methylene chloride I subsequently used + + + align:start position:0% +methylene chloride I subsequently used +it in stripping paint it's very vicious + + align:start position:0% +it in stripping paint it's very vicious + + + align:start position:0% +it in stripping paint it's very vicious +you see the trick in decaffeinating + + align:start position:0% +you see the trick in decaffeinating + + + align:start position:0% +you see the trick in decaffeinating +coffee is to get the caffeine out but + + align:start position:0% +coffee is to get the caffeine out but + + + align:start position:0% +coffee is to get the caffeine out but +not to brew the coffee you want to + + align:start position:0% +not to brew the coffee you want to + + + align:start position:0% +not to brew the coffee you want to +selectively get the caffeine so now they + + align:start position:0% +selectively get the caffeine so now they + + + align:start position:0% +selectively get the caffeine so now they +use uh super critical carbon dioxide so + + align:start position:0% +use uh super critical carbon dioxide so + + + align:start position:0% +use uh super critical carbon dioxide so +carbon dioxide leeches out the C + + align:start position:0% +carbon dioxide leeches out the C + + + align:start position:0% +carbon dioxide leeches out the C +caffeine but doesn't touch the coffee so + + align:start position:0% +caffeine but doesn't touch the coffee so + + + align:start position:0% +caffeine but doesn't touch the coffee so +you get up into that uh temperature + + align:start position:0% +you get up into that uh temperature + + + align:start position:0% +you get up into that uh temperature +pressure regime leech out the caffeine + + align:start position:0% +pressure regime leech out the caffeine + + + align:start position:0% +pressure regime leech out the caffeine +and then you change temperature and + + align:start position:0% +and then you change temperature and + + + align:start position:0% +and then you change temperature and +pressure and now you have this pregnant + + align:start position:0% +pressure and now you have this pregnant + + + align:start position:0% +pressure and now you have this pregnant +liquor that is exceeding the solubility + + align:start position:0% +liquor that is exceeding the solubility + + + align:start position:0% +liquor that is exceeding the solubility +product and now you exsolve the caffeine + + align:start position:0% +product and now you exsolve the caffeine + + + align:start position:0% +product and now you exsolve the caffeine +and then you reflux the CO2 and that's + + align:start position:0% +and then you reflux the CO2 and that's + + + align:start position:0% +and then you reflux the CO2 and that's +how we we go about uh with the uh coffee + + align:start position:0% +how we we go about uh with the uh coffee + + + align:start position:0% +how we we go about uh with the uh coffee +the last thing I'm going to do uh before + + align:start position:0% +the last thing I'm going to do uh before + + + align:start position:0% +the last thing I'm going to do uh before +I introduce uh someone's going to tell + + align:start position:0% +I introduce uh someone's going to tell + + + align:start position:0% +I introduce uh someone's going to tell +you about some other activities that + + align:start position:0% +you about some other activities that + + + align:start position:0% +you about some other activities that +will happen during IAP is to tell you + + align:start position:0% +will happen during IAP is to tell you + + + align:start position:0% +will happen during IAP is to tell you +about uh I guess this lesson is that + + align:start position:0% +about uh I guess this lesson is that + + + align:start position:0% +about uh I guess this lesson is that +there are no depths uh uh there are no + + align:start position:0% +there are no depths uh uh there are no + + + align:start position:0% +there are no depths uh uh there are no +limits to the depths of human stupidity + + align:start position:0% +limits to the depths of human stupidity + + + align:start position:0% +limits to the depths of human stupidity +um this is this will tie in denaturing + + align:start position:0% +um this is this will tie in denaturing + + + align:start position:0% +um this is this will tie in denaturing +of protein from last day this is a news + + align:start position:0% +of protein from last day this is a news + + + align:start position:0% +of protein from last day this is a news +thing dick Kinga P principle at + + align:start position:0% +thing dick Kinga P principle at + + + align:start position:0% +thing dick Kinga P principle at +Silverton High School said this is in + + align:start position:0% +Silverton High School said this is in + + + align:start position:0% +Silverton High School said this is in +Silverton Oregon and I'm not making this + + align:start position:0% +Silverton Oregon and I'm not making this + + + align:start position:0% +Silverton Oregon and I'm not making this +up said a pep rally stunt that burn + + align:start position:0% +up said a pep rally stunt that burn + + + align:start position:0% +up said a pep rally stunt that burn +Force students won't ever be repeated + + align:start position:0% +Force students won't ever be repeated + + + align:start position:0% +Force students won't ever be repeated +the fource suffered severe burns on + + align:start position:0% +the fource suffered severe burns on + + + align:start position:0% +the fource suffered severe burns on +their buttocks from sitting on blocks of + + align:start position:0% +their buttocks from sitting on blocks of + + + align:start position:0% +their buttocks from sitting on blocks of +dry + + align:start position:0% +dry + + + align:start position:0% +dry +ice the girls were chosen by their + + align:start position:0% +ice the girls were chosen by their + + + align:start position:0% +ice the girls were chosen by their +classmates for a stunt to see who could + + align:start position:0% +classmates for a stunt to see who could + + + align:start position:0% +classmates for a stunt to see who could +sit on the ice the longest the dry ice + + align:start position:0% +sit on the ice the longest the dry ice + + + align:start position:0% +sit on the ice the longest the dry ice +or solid carbon dioxide can be as cold + + align:start position:0% +or solid carbon dioxide can be as cold + + + align:start position:0% +or solid carbon dioxide can be as cold +as 112 Fahrenheit below zero the four + + align:start position:0% +as 112 Fahrenheit below zero the four + + + align:start position:0% +as 112 Fahrenheit below zero the four +were treated at Silverton Hospital Dr + + align:start position:0% +were treated at Silverton Hospital Dr + + + align:start position:0% +were treated at Silverton Hospital Dr +Frank lord said some of the girls may + + align:start position:0% +Frank lord said some of the girls may + + + align:start position:0% +Frank lord said some of the girls may +need skin grafts theyve denatured the + + align:start position:0% +need skin grafts theyve denatured the + + + align:start position:0% +need skin grafts theyve denatured the +proteins this is a quote the truth is + + align:start position:0% +proteins this is a quote the truth is + + + align:start position:0% +proteins this is a quote the truth is +I've never seen any frostbite on this + + align:start position:0% +I've never seen any frostbite on this + + + align:start position:0% +I've never seen any frostbite on this +part of the + + align:start position:0% +part of the + + + align:start position:0% +part of the +anatomy anyways it goes on about how + + align:start position:0% +anatomy anyways it goes on about how + + + align:start position:0% +anatomy anyways it goes on about how +this was tied in with + + align:start position:0% +this was tied in with + + + align:start position:0% +this was tied in with +football homecoming and and some + + align:start position:0% +football homecoming and and some + + + align:start position:0% +football homecoming and and some +somebody just didn't didn't pay + + align:start position:0% +somebody just didn't didn't pay + + + align:start position:0% +somebody just didn't didn't pay +attention \ No newline at end of file diff --git a/EXYgISgOw0g.txt b/EXYgISgOw0g.txt new file mode 100644 index 0000000000000000000000000000000000000000..546a0571c8bd7b2c35afe08f9e638e098ad82fb7 --- /dev/null +++ b/EXYgISgOw0g.txt @@ -0,0 +1,851 @@ +align:start position:0% + +in this video we'll discuss how + + align:start position:0% +in this video we'll discuss how + + + align:start position:0% +in this video we'll discuss how +radiation therapy can be framed as an + + align:start position:0% +radiation therapy can be framed as an + + + align:start position:0% +radiation therapy can be framed as an +optimization problem the data is + + align:start position:0% +optimization problem the data is + + + align:start position:0% +optimization problem the data is +collected in the treatment planning + + align:start position:0% +collected in the treatment planning + + + align:start position:0% +collected in the treatment planning +process which starts from a CT scan like + + align:start position:0% +process which starts from a CT scan like + + + align:start position:0% +process which starts from a CT scan like +the one you see here on the right using + + align:start position:0% +the one you see here on the right using + + + align:start position:0% +the one you see here on the right using +the CT scan a radiation oncologist + + align:start position:0% +the CT scan a radiation oncologist + + + align:start position:0% +the CT scan a radiation oncologist +contours or draws out lines around the + + align:start position:0% +contours or draws out lines around the + + + align:start position:0% +contours or draws out lines around the +tumor and various critical structures in + + align:start position:0% +tumor and various critical structures in + + + align:start position:0% +tumor and various critical structures in +this image the oncologist would contour + + align:start position:0% +this image the oncologist would contour + + + align:start position:0% +this image the oncologist would contour +structures like the parotid glands the + + align:start position:0% +structures like the parotid glands the + + + align:start position:0% +structures like the parotid glands the +largest of the saliva glands and the + + align:start position:0% +largest of the saliva glands and the + + + align:start position:0% +largest of the saliva glands and the +brain then each structure is discretized + + align:start position:0% +brain then each structure is discretized + + + align:start position:0% +brain then each structure is discretized +into voxels or volume elements which are + + align:start position:0% +into voxels or volume elements which are + + + align:start position:0% +into voxels or volume elements which are +typically four millimeters in dimension + + align:start position:0% +typically four millimeters in dimension + + + align:start position:0% +typically four millimeters in dimension +the second image here shows a closer + + align:start position:0% +the second image here shows a closer + + + align:start position:0% +the second image here shows a closer +view of the brain you can see the small + + align:start position:0% +view of the brain you can see the small + + + align:start position:0% +view of the brain you can see the small +squares or voxels here they're + + align:start position:0% +squares or voxels here they're + + + align:start position:0% +squares or voxels here they're +two-dimensional but in reality they + + align:start position:0% +two-dimensional but in reality they + + + align:start position:0% +two-dimensional but in reality they +would be 3-dimensional now we can + + align:start position:0% +would be 3-dimensional now we can + + + align:start position:0% +would be 3-dimensional now we can +compute how much dose each beam lit or + + align:start position:0% +compute how much dose each beam lit or + + + align:start position:0% +compute how much dose each beam lit or +piece of the beam + + align:start position:0% +piece of the beam + + + align:start position:0% +piece of the beam +delivers to each voxel we'll start with + + align:start position:0% +delivers to each voxel we'll start with + + + align:start position:0% +delivers to each voxel we'll start with +a small example suppose we have nine + + align:start position:0% +a small example suppose we have nine + + + align:start position:0% +a small example suppose we have nine +voxels and six beam let's our voxels can + + align:start position:0% +voxels and six beam let's our voxels can + + + align:start position:0% +voxels and six beam let's our voxels can +be categorized into three types the + + align:start position:0% +be categorized into three types the + + + align:start position:0% +be categorized into three types the +tumor voxels which are colored pink here + + align:start position:0% +tumor voxels which are colored pink here + + + align:start position:0% +tumor voxels which are colored pink here +the spinal cord voxel colored dark green + + align:start position:0% +the spinal cord voxel colored dark green + + + align:start position:0% +the spinal cord voxel colored dark green +and other healthy tissue voxels colored + + align:start position:0% +and other healthy tissue voxels colored + + + align:start position:0% +and other healthy tissue voxels colored +light green so we have four tumor voxels + + align:start position:0% +light green so we have four tumor voxels + + + align:start position:0% +light green so we have four tumor voxels +one spinal cord voxel and four other + + align:start position:0% +one spinal cord voxel and four other + + + align:start position:0% +one spinal cord voxel and four other +healthy tissue boxes we have two beams + + align:start position:0% +healthy tissue boxes we have two beams + + + align:start position:0% +healthy tissue boxes we have two beams +that are each split into three beam + + align:start position:0% +that are each split into three beam + + + align:start position:0% +that are each split into three beam +let's beam one is composed of beam let's + + align:start position:0% +let's beam one is composed of beam let's + + + align:start position:0% +let's beam one is composed of beam let's +one two and three and comes in from the + + align:start position:0% +one two and three and comes in from the + + + align:start position:0% +one two and three and comes in from the +right beam two is composed of beam let's + + align:start position:0% +right beam two is composed of beam let's + + + align:start position:0% +right beam two is composed of beam let's +four five and six and comes in from the + + align:start position:0% +four five and six and comes in from the + + + align:start position:0% +four five and six and comes in from the +top our objective is to minimize the + + align:start position:0% +top our objective is to minimize the + + + align:start position:0% +top our objective is to minimize the +total dose to healthy tissue + + align:start position:0% +total dose to healthy tissue + + + align:start position:0% +total dose to healthy tissue +both to the spinal cord and to the other + + align:start position:0% +both to the spinal cord and to the other + + + align:start position:0% +both to the spinal cord and to the other +healthy tissue we have two types of + + align:start position:0% +healthy tissue we have two types of + + + align:start position:0% +healthy tissue we have two types of +constraints the first is that the dose + + align:start position:0% +constraints the first is that the dose + + + align:start position:0% +constraints the first is that the dose +to the tumor voxels must be at least + + align:start position:0% +to the tumor voxels must be at least + + + align:start position:0% +to the tumor voxels must be at least +seven gray + + align:start position:0% +seven gray + + + align:start position:0% +seven gray +which is the unit of measure for + + align:start position:0% +which is the unit of measure for + + + align:start position:0% +which is the unit of measure for +radiation our second constraint is that + + align:start position:0% +radiation our second constraint is that + + + align:start position:0% +radiation our second constraint is that +the dose to the spinal cord voxel can't + + align:start position:0% +the dose to the spinal cord voxel can't + + + align:start position:0% +the dose to the spinal cord voxel can't +be more than five gray since we want to + + align:start position:0% +be more than five gray since we want to + + + align:start position:0% +be more than five gray since we want to +be careful to protect the spinal cord we + + align:start position:0% +be careful to protect the spinal cord we + + + align:start position:0% +be careful to protect the spinal cord we +know the dose that each beam lit gives + + align:start position:0% +know the dose that each beam lit gives + + + align:start position:0% +know the dose that each beam lit gives +to each voxel at unit intensity this + + align:start position:0% +to each voxel at unit intensity this + + + align:start position:0% +to each voxel at unit intensity this +table shows the dose that each beam + + align:start position:0% +table shows the dose that each beam + + + align:start position:0% +table shows the dose that each beam +length and beam one gives to the voxels + + align:start position:0% +length and beam one gives to the voxels + + + align:start position:0% +length and beam one gives to the voxels +remember that this is at unit intensity + + align:start position:0% +remember that this is at unit intensity + + + align:start position:0% +remember that this is at unit intensity +if we double the intensity of the beam + + align:start position:0% +if we double the intensity of the beam + + + align:start position:0% +if we double the intensity of the beam +light we double the doses the dose to + + align:start position:0% +light we double the doses the dose to + + + align:start position:0% +light we double the doses the dose to +each voxel can depend on how far the + + align:start position:0% +each voxel can depend on how far the + + + align:start position:0% +each voxel can depend on how far the +beam that has to travel or the type of + + align:start position:0% +beam that has to travel or the type of + + + align:start position:0% +beam that has to travel or the type of +tissue that the beam light has to travel + + align:start position:0% +tissue that the beam light has to travel + + + align:start position:0% +tissue that the beam light has to travel +through similarly we know the dose that + + align:start position:0% +through similarly we know the dose that + + + align:start position:0% +through similarly we know the dose that +each beam l''m beam 2 gives to each + + align:start position:0% +each beam l''m beam 2 gives to each + + + align:start position:0% +each beam l''m beam 2 gives to each +voxel again at unit intensity the dose + + align:start position:0% +voxel again at unit intensity the dose + + + align:start position:0% +voxel again at unit intensity the dose +depends on the direction of the beam and + + align:start position:0% +depends on the direction of the beam and + + + align:start position:0% +depends on the direction of the beam and +what it travels through putting these + + align:start position:0% +what it travels through putting these + + + align:start position:0% +what it travels through putting these +tables together we can write out our + + align:start position:0% +tables together we can write out our + + + align:start position:0% +tables together we can write out our +optimization problem our decision + + align:start position:0% +optimization problem our decision + + + align:start position:0% +optimization problem our decision +variables are the intensities of each + + align:start position:0% +variables are the intensities of each + + + align:start position:0% +variables are the intensities of each +beam what we'll call them x1 the + + align:start position:0% +beam what we'll call them x1 the + + + align:start position:0% +beam what we'll call them x1 the +intensity for beam lint 1 x2 the + + align:start position:0% +intensity for beam lint 1 x2 the + + + align:start position:0% +intensity for beam lint 1 x2 the +intensity for beam light 2 x3 the + + align:start position:0% +intensity for beam light 2 x3 the + + + align:start position:0% +intensity for beam light 2 x3 the +intensity for beam 1 3 etc all the way + + align:start position:0% +intensity for beam 1 3 etc all the way + + + align:start position:0% +intensity for beam 1 3 etc all the way +up through x6 as we mentioned before our + + align:start position:0% +up through x6 as we mentioned before our + + + align:start position:0% +up through x6 as we mentioned before our +objective is to minimize the total dose + + align:start position:0% +objective is to minimize the total dose + + + align:start position:0% +objective is to minimize the total dose +to the healthy tissue including the + + align:start position:0% +to the healthy tissue including the + + + align:start position:0% +to the healthy tissue including the +spinal cord so we want to minimize the + + align:start position:0% +spinal cord so we want to minimize the + + + align:start position:0% +spinal cord so we want to minimize the +total dose beam lit one gives to healthy + + align:start position:0% +total dose beam lit one gives to healthy + + + align:start position:0% +total dose beam lit one gives to healthy +tissue which is 1 plus 2 times x1 plus + + align:start position:0% +tissue which is 1 plus 2 times x1 plus + + + align:start position:0% +tissue which is 1 plus 2 times x1 plus +the total dose beam what 2 gives to + + align:start position:0% +the total dose beam what 2 gives to + + + align:start position:0% +the total dose beam what 2 gives to +healthy tissue which is 2 plus 2.5 times + + align:start position:0% +healthy tissue which is 2 plus 2.5 times + + + align:start position:0% +healthy tissue which is 2 plus 2.5 times +x2 plus the total dose beam let three + + align:start position:0% +x2 plus the total dose beam let three + + + align:start position:0% +x2 plus the total dose beam let three +gifts to healthy tissue which is 2.5 X 3 + + align:start position:0% +gifts to healthy tissue which is 2.5 X 3 + + + align:start position:0% +gifts to healthy tissue which is 2.5 X 3 +now for beam what's 4 5 & 6 beam what + + align:start position:0% +now for beam what's 4 5 & 6 beam what + + + align:start position:0% +now for beam what's 4 5 & 6 beam what +for just gives one dose to healthy + + align:start position:0% +for just gives one dose to healthy + + + align:start position:0% +for just gives one dose to healthy +tissue beam what 5 2 times X 5 and then + + align:start position:0% +tissue beam what 5 2 times X 5 and then + + + align:start position:0% +tissue beam what 5 2 times X 5 and then +beam lit 6 we have 1 plus 2 plus 1 times + + align:start position:0% +beam lit 6 we have 1 plus 2 plus 1 times + + + align:start position:0% +beam lit 6 we have 1 plus 2 plus 1 times +X + + align:start position:0% +X + + + align:start position:0% +X +now for our constraints first we need to + + align:start position:0% +now for our constraints first we need to + + + align:start position:0% +now for our constraints first we need to +make sure that each voxel of the tumor + + align:start position:0% +make sure that each voxel of the tumor + + + align:start position:0% +make sure that each voxel of the tumor +gets a dose of at least seven let's + + align:start position:0% +gets a dose of at least seven let's + + + align:start position:0% +gets a dose of at least seven let's +start with the first tumor voxel in the + + align:start position:0% +start with the first tumor voxel in the + + + align:start position:0% +start with the first tumor voxel in the +top row so 2 times X 1 plus X 5 needs to + + align:start position:0% +top row so 2 times X 1 plus X 5 needs to + + + align:start position:0% +top row so 2 times X 1 plus X 5 needs to +be greater than or equal to 7 now the + + align:start position:0% +be greater than or equal to 7 now the + + + align:start position:0% +be greater than or equal to 7 now the +tumor voxel in the second row we have X + + align:start position:0% +tumor voxel in the second row we have X + + + align:start position:0% +tumor voxel in the second row we have X +2 plus 2 X 4 also greater than or equal + + align:start position:0% +2 plus 2 X 4 also greater than or equal + + + align:start position:0% +2 plus 2 X 4 also greater than or equal +to 7 now for the two tumor voxels in the + + align:start position:0% +to 7 now for the two tumor voxels in the + + + align:start position:0% +to 7 now for the two tumor voxels in the +bottom row we have 1.5 X 3 plus x4 + + align:start position:0% +bottom row we have 1.5 X 3 plus x4 + + + align:start position:0% +bottom row we have 1.5 X 3 plus x4 +greater than or equal to 7 and 1.5 X 3 + + align:start position:0% +greater than or equal to 7 and 1.5 X 3 + + + align:start position:0% +greater than or equal to 7 and 1.5 X 3 +plus X 5 greater than or equal to 7 then + + align:start position:0% +plus X 5 greater than or equal to 7 then + + + align:start position:0% +plus X 5 greater than or equal to 7 then +for the spinal cord we need to make sure + + align:start position:0% +for the spinal cord we need to make sure + + + align:start position:0% +for the spinal cord we need to make sure +that 2 times X 2 plus 2 times X 5 is + + align:start position:0% +that 2 times X 2 plus 2 times X 5 is + + + align:start position:0% +that 2 times X 2 plus 2 times X 5 is +less than or equal to 5 and lastly we + + align:start position:0% +less than or equal to 5 and lastly we + + + align:start position:0% +less than or equal to 5 and lastly we +just need to make sure that all of our + + align:start position:0% +just need to make sure that all of our + + + align:start position:0% +just need to make sure that all of our +decision variables are non-negative so + + align:start position:0% + + + + align:start position:0% + +they should all be greater than or equal + + align:start position:0% +they should all be greater than or equal + + + align:start position:0% +they should all be greater than or equal +to 0 now that we've set up our + + align:start position:0% +to 0 now that we've set up our + + + align:start position:0% +to 0 now that we've set up our +optimization problem we'll solve it in + + align:start position:0% +optimization problem we'll solve it in + + + align:start position:0% +optimization problem we'll solve it in +libreoffice in the next video \ No newline at end of file diff --git a/EXYw8_pnKr0.txt b/EXYw8_pnKr0.txt new file mode 100644 index 0000000000000000000000000000000000000000..660636a7366626f0d10961673cdf92a4ebbe4cac --- /dev/null +++ b/EXYw8_pnKr0.txt @@ -0,0 +1,8651 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +another lecture in my series on Urban + + align:start position:0% +another lecture in my series on Urban + + + align:start position:0% +another lecture in my series on Urban +Energy Systems and policy my name is + + align:start position:0% +Energy Systems and policy my name is + + + align:start position:0% +Energy Systems and policy my name is +David Sue I'm an associate professor of + + align:start position:0% +David Sue I'm an associate professor of + + + align:start position:0% +David Sue I'm an associate professor of +urban studies and planning MIT + + align:start position:0% +urban studies and planning MIT + + + align:start position:0% +urban studies and planning MIT +and this week I want to talk about + + align:start position:0% +and this week I want to talk about + + + align:start position:0% +and this week I want to talk about +cities and buildings and Energy + + align:start position:0% +cities and buildings and Energy + + + align:start position:0% +cities and buildings and Energy +Efficiency + + align:start position:0% +Efficiency + + + align:start position:0% +Efficiency +the class materials or the materials for + + align:start position:0% +the class materials or the materials for + + + align:start position:0% +the class materials or the materials for +class discussion on Tuesday are in the + + align:start position:0% +class discussion on Tuesday are in the + + + align:start position:0% +class discussion on Tuesday are in the +syllabus we'll talk mostly about the + + align:start position:0% +syllabus we'll talk mostly about the + + + align:start position:0% +syllabus we'll talk mostly about the +Makai reading today the first bullet + + align:start position:0% +Makai reading today the first bullet + + + align:start position:0% +Makai reading today the first bullet +point but we'll talk about the other + + align:start position:0% +point but we'll talk about the other + + + align:start position:0% +point but we'll talk about the other +readings in class on Tuesday + + align:start position:0% +readings in class on Tuesday + + + align:start position:0% +readings in class on Tuesday +I don't really want to start with this + + align:start position:0% +I don't really want to start with this + + + align:start position:0% +I don't really want to start with this +quote you may have heard this quote + + align:start position:0% +quote you may have heard this quote + + + align:start position:0% +quote you may have heard this quote +before + + align:start position:0% +before + + + align:start position:0% +before +it's from Winston Churchill it's in a + + align:start position:0% +it's from Winston Churchill it's in a + + + align:start position:0% +it's from Winston Churchill it's in a +speech he gave after the bombing of the + + align:start position:0% +speech he gave after the bombing of the + + + align:start position:0% +speech he gave after the bombing of the +House of Commons after a raid in the + + align:start position:0% +House of Commons after a raid in the + + + align:start position:0% +House of Commons after a raid in the +London Blitz and he says we shaped + + align:start position:0% +London Blitz and he says we shaped + + + align:start position:0% +London Blitz and he says we shaped +buildings and afterwards our buildings + + align:start position:0% +buildings and afterwards our buildings + + + align:start position:0% +buildings and afterwards our buildings +shape us at the time they're discussing + + align:start position:0% +shape us at the time they're discussing + + + align:start position:0% +shape us at the time they're discussing +how or whether to rebuild the House of + + align:start position:0% +how or whether to rebuild the House of + + + align:start position:0% +how or whether to rebuild the House of +Commons after it was hit by a bomb but I + + align:start position:0% +Commons after it was hit by a bomb but I + + + align:start position:0% +Commons after it was hit by a bomb but I +think it's a evocative quote that gets + + align:start position:0% +think it's a evocative quote that gets + + + align:start position:0% +think it's a evocative quote that gets +used quite often to describe what the + + align:start position:0% +used quite often to describe what the + + + align:start position:0% +used quite often to describe what the +influence of buildings on culture is and + + align:start position:0% +influence of buildings on culture is and + + + align:start position:0% +influence of buildings on culture is and +I've had a lifelong Fascination + + align:start position:0% +I've had a lifelong Fascination + + + align:start position:0% +I've had a lifelong Fascination +architecture and so what I want to focus + + align:start position:0% +architecture and so what I want to focus + + + align:start position:0% +architecture and so what I want to focus +on today is how buildings reflect many + + align:start position:0% +on today is how buildings reflect many + + + align:start position:0% +on today is how buildings reflect many +different things Energy Efficiency is + + align:start position:0% +different things Energy Efficiency is + + + align:start position:0% +different things Energy Efficiency is +not usually at the top of anyone's list + + align:start position:0% +not usually at the top of anyone's list + + + align:start position:0% +not usually at the top of anyone's list +of concerns at the same time I hope to + + align:start position:0% +of concerns at the same time I hope to + + + align:start position:0% +of concerns at the same time I hope to +convince you that buildings are an + + align:start position:0% +convince you that buildings are an + + + align:start position:0% +convince you that buildings are an +incredibly important part of our problem + + align:start position:0% +incredibly important part of our problem + + + align:start position:0% +incredibly important part of our problem +that we need to tackle for the energy + + align:start position:0% +that we need to tackle for the energy + + + align:start position:0% +that we need to tackle for the energy +transition and also + + align:start position:0% +transition and also + + + align:start position:0% +transition and also +also argue that there's ways that we can + + align:start position:0% +also argue that there's ways that we can + + + align:start position:0% +also argue that there's ways that we can +shape buildings that will shape our + + align:start position:0% +shape buildings that will shape our + + + align:start position:0% +shape buildings that will shape our +later energy using behaviors + + align:start position:0% +later energy using behaviors + + + align:start position:0% +later energy using behaviors +and so just to give you a few arguments + + align:start position:0% +and so just to give you a few arguments + + + align:start position:0% +and so just to give you a few arguments +about why buildings are so important for + + align:start position:0% +about why buildings are so important for + + + align:start position:0% +about why buildings are so important for +energy use and climate change in terms + + align:start position:0% +energy use and climate change in terms + + + align:start position:0% +energy use and climate change in terms +of operational energy buildings about 35 + + align:start position:0% +of operational energy buildings about 35 + + + align:start position:0% +of operational energy buildings about 35 +percent of the primary energy used in + + align:start position:0% +percent of the primary energy used in + + + align:start position:0% +percent of the primary energy used in +the world they were responsible for + + align:start position:0% +the world they were responsible for + + + align:start position:0% +the world they were responsible for +about 38 of greenhouse gas emissions + + align:start position:0% +about 38 of greenhouse gas emissions + + + align:start position:0% +about 38 of greenhouse gas emissions +worldwide + + align:start position:0% +worldwide + + + align:start position:0% +worldwide +and it's also worth noting that for + + align:start position:0% +and it's also worth noting that for + + + align:start position:0% +and it's also worth noting that for +cities in particular the subject of this + + align:start position:0% +cities in particular the subject of this + + + align:start position:0% +cities in particular the subject of this +course uh buildings are a much higher + + align:start position:0% +course uh buildings are a much higher + + + align:start position:0% +course uh buildings are a much higher +percentage of City emissions in New York + + align:start position:0% +percentage of City emissions in New York + + + align:start position:0% +percentage of City emissions in New York +City buildings represent about 70 + + align:start position:0% +City buildings represent about 70 + + + align:start position:0% +City buildings represent about 70 +percent of the greenhouse gas emissions + + align:start position:0% +percent of the greenhouse gas emissions + + + align:start position:0% +percent of the greenhouse gas emissions +though we also have to kind of be aware + + align:start position:0% +though we also have to kind of be aware + + + align:start position:0% +though we also have to kind of be aware +that you know this is also reflective of + + align:start position:0% +that you know this is also reflective of + + + align:start position:0% +that you know this is also reflective of +as I've said before New York City being + + align:start position:0% +as I've said before New York City being + + + align:start position:0% +as I've said before New York City being +a financial center in Singapore uh + + align:start position:0% +a financial center in Singapore uh + + + align:start position:0% +a financial center in Singapore uh +buildings are only 20 of greenhouse gas + + align:start position:0% +buildings are only 20 of greenhouse gas + + + align:start position:0% +buildings are only 20 of greenhouse gas +emissions because Singapore has a + + align:start position:0% +emissions because Singapore has a + + + align:start position:0% +emissions because Singapore has a +surprisingly large industrial-based uh + + align:start position:0% +surprisingly large industrial-based uh + + + align:start position:0% +surprisingly large industrial-based uh +specifically of uh liquid natural gas + + align:start position:0% +specifically of uh liquid natural gas + + + align:start position:0% +specifically of uh liquid natural gas +processing + + align:start position:0% +processing + + + align:start position:0% +processing +but in terms of embodying energy + + align:start position:0% +but in terms of embodying energy + + + align:start position:0% +but in terms of embodying energy +buildings represent also their + + align:start position:0% +buildings represent also their + + + align:start position:0% +buildings represent also their +construction represents a significant + + align:start position:0% +construction represents a significant + + + align:start position:0% +construction represents a significant +additional portion of their energy use + + align:start position:0% +additional portion of their energy use + + + align:start position:0% +additional portion of their energy use +and greenhouse gas emissions the + + align:start position:0% +and greenhouse gas emissions the + + + align:start position:0% +and greenhouse gas emissions the +building construction industry is + + align:start position:0% +building construction industry is + + + align:start position:0% +building construction industry is +responsible for about five percent of + + align:start position:0% +responsible for about five percent of + + + align:start position:0% +responsible for about five percent of +the primary energy use in the world uh + + align:start position:0% +the primary energy use in the world uh + + + align:start position:0% +the primary energy use in the world uh +10 of emissions + + align:start position:0% +10 of emissions + + + align:start position:0% +10 of emissions +and it's also worth noting that in + + align:start position:0% +and it's also worth noting that in + + + align:start position:0% +and it's also worth noting that in +cities like New York many of the cities + + align:start position:0% +cities like New York many of the cities + + + align:start position:0% +cities like New York many of the cities +that are as many of the buildings that + + align:start position:0% +that are as many of the buildings that + + + align:start position:0% +that are as many of the buildings that +are already there here in 2022 are going + + align:start position:0% +are already there here in 2022 are going + + + align:start position:0% +are already there here in 2022 are going +to be there for our mid-centric Bull in + + align:start position:0% +to be there for our mid-centric Bull in + + + align:start position:0% +to be there for our mid-centric Bull in +2050. so a key part of our challenge for + + align:start position:0% +2050. so a key part of our challenge for + + + align:start position:0% +2050. so a key part of our challenge for +addressing buildings is retrofitting the + + align:start position:0% +addressing buildings is retrofitting the + + + align:start position:0% +addressing buildings is retrofitting the +existing buildings we have new + + align:start position:0% +existing buildings we have new + + + align:start position:0% +existing buildings we have new +construction may be occurring in other + + align:start position:0% +construction may be occurring in other + + + align:start position:0% +construction may be occurring in other +cities that are faster growing but New + + align:start position:0% +cities that are faster growing but New + + + align:start position:0% +cities that are faster growing but New +York City is already quite dense we + + align:start position:0% +York City is already quite dense we + + + align:start position:0% +York City is already quite dense we +actually need to figure out how to + + align:start position:0% +actually need to figure out how to + + + align:start position:0% +actually need to figure out how to +retrofit the millions of buildings we + + align:start position:0% +retrofit the millions of buildings we + + + align:start position:0% +retrofit the millions of buildings we +already have in New York City + + align:start position:0% +already have in New York City + + + align:start position:0% +already have in New York City +it's also important to note that + + align:start position:0% +it's also important to note that + + + align:start position:0% +it's also important to note that +buildings shape our health and we're + + align:start position:0% +buildings shape our health and we're + + + align:start position:0% +buildings shape our health and we're +quite concerned about how buildings + + align:start position:0% +quite concerned about how buildings + + + align:start position:0% +quite concerned about how buildings +affect our health uh this famous + + align:start position:0% +affect our health uh this famous + + + align:start position:0% +affect our health uh this famous +statistic from Lawrence Berkeley + + align:start position:0% +statistic from Lawrence Berkeley + + + align:start position:0% +statistic from Lawrence Berkeley +National Laboratory using the American + + align:start position:0% +National Laboratory using the American + + + align:start position:0% +National Laboratory using the American +timing survey basically asks people how + + align:start position:0% +timing survey basically asks people how + + + align:start position:0% +timing survey basically asks people how +much time do they spend and where and + + align:start position:0% +much time do they spend and where and + + + align:start position:0% +much time do they spend and where and +they find that people spend about 87 + + align:start position:0% +they find that people spend about 87 + + + align:start position:0% +they find that people spend about 87 +percent of their lives and yours and on + + align:start position:0% +percent of their lives and yours and on + + + align:start position:0% +percent of their lives and yours and on +six percent of their time in enclosed + + align:start position:0% +six percent of their time in enclosed + + + align:start position:0% +six percent of their time in enclosed +Vehicles so 93 of their time is + + align:start position:0% +Vehicles so 93 of their time is + + + align:start position:0% +Vehicles so 93 of their time is +essentially spent in spaces that can be + + align:start position:0% +essentially spent in spaces that can be + + + align:start position:0% +essentially spent in spaces that can be +air-conditioned or affected by air + + align:start position:0% +air-conditioned or affected by air + + + align:start position:0% +air-conditioned or affected by air +conditioning + + align:start position:0% +conditioning + + + align:start position:0% +conditioning +of course after three years of covid we + + align:start position:0% +of course after three years of covid we + + + align:start position:0% +of course after three years of covid we +don't probably need to reinforce this + + align:start position:0% +don't probably need to reinforce this + + + align:start position:0% +don't probably need to reinforce this +coin too much but covid and our + + align:start position:0% +coin too much but covid and our + + + align:start position:0% +coin too much but covid and our +concerned about ventilation have + + align:start position:0% +concerned about ventilation have + + + align:start position:0% +concerned about ventilation have +fundamentally affected our desire for + + align:start position:0% +fundamentally affected our desire for + + + align:start position:0% +fundamentally affected our desire for +Real Estate now Recent research from the + + align:start position:0% +Real Estate now Recent research from the + + + align:start position:0% +Real Estate now Recent research from the +San Francisco fed that Paul Krugman has + + align:start position:0% +San Francisco fed that Paul Krugman has + + + align:start position:0% +San Francisco fed that Paul Krugman has +written about is essentially looking at + + align:start position:0% +written about is essentially looking at + + + align:start position:0% +written about is essentially looking at +inflation and the contribution of real + + align:start position:0% +inflation and the contribution of real + + + align:start position:0% +inflation and the contribution of real +estate to inflation and he argued I + + align:start position:0% +estate to inflation and he argued I + + + align:start position:0% +estate to inflation and he argued I +think like convincingly that there's a + + align:start position:0% +think like convincingly that there's a + + + align:start position:0% +think like convincingly that there's a +kind of secular shift in what people + + align:start position:0% +kind of secular shift in what people + + + align:start position:0% +kind of secular shift in what people +want people need more space or Zoom + + align:start position:0% +want people need more space or Zoom + + + align:start position:0% +want people need more space or Zoom +calls for spending their time at home + + align:start position:0% +calls for spending their time at home + + + align:start position:0% +calls for spending their time at home +this ties into the remote work trends + + align:start position:0% +this ties into the remote work trends + + + align:start position:0% +this ties into the remote work trends +that we talked about last week + + align:start position:0% +that we talked about last week + + + align:start position:0% +that we talked about last week +and of course we should not forget that + + align:start position:0% +and of course we should not forget that + + + align:start position:0% +and of course we should not forget that +there's always a crisis or there is a + + align:start position:0% +there's always a crisis or there is a + + + align:start position:0% +there's always a crisis or there is a +increasing crisis in providing + + align:start position:0% +increasing crisis in providing + + + align:start position:0% +increasing crisis in providing +affordable and sufficient housing not + + align:start position:0% +affordable and sufficient housing not + + + align:start position:0% +affordable and sufficient housing not +only in this country and in our major + + align:start position:0% +only in this country and in our major + + + align:start position:0% +only in this country and in our major +cities but in many countries also so + + align:start position:0% +cities but in many countries also so + + + align:start position:0% +cities but in many countries also so +when we think talk about buildings we + + align:start position:0% +when we think talk about buildings we + + + align:start position:0% +when we think talk about buildings we +need to think about what we're trying to + + align:start position:0% +need to think about what we're trying to + + + align:start position:0% +need to think about what we're trying to +provide uh fundamentally is a habitat or + + align:start position:0% +provide uh fundamentally is a habitat or + + + align:start position:0% +provide uh fundamentally is a habitat or +Shelter From the environment + + align:start position:0% +Shelter From the environment + + + align:start position:0% +Shelter From the environment +but how we do that have tremendous + + align:start position:0% +but how we do that have tremendous + + + align:start position:0% +but how we do that have tremendous +implications for our energy use and + + align:start position:0% +implications for our energy use and + + + align:start position:0% +implications for our energy use and +climate goals and so finally what we'll + + align:start position:0% +climate goals and so finally what we'll + + + align:start position:0% +climate goals and so finally what we'll +talk about in this lectures mostly the + + align:start position:0% +talk about in this lectures mostly the + + + align:start position:0% +talk about in this lectures mostly the +Makai reading uh he focuses on how much + + align:start position:0% +Makai reading uh he focuses on how much + + + align:start position:0% +Makai reading uh he focuses on how much +it takes to heat cool and use various + + align:start position:0% +it takes to heat cool and use various + + + align:start position:0% +it takes to heat cool and use various +appliances and we're really trying to + + align:start position:0% +appliances and we're really trying to + + + align:start position:0% +appliances and we're really trying to +get some underlying questions how much + + align:start position:0% +get some underlying questions how much + + + align:start position:0% +get some underlying questions how much +energy is used in buildings how much + + align:start position:0% +energy is used in buildings how much + + + align:start position:0% +energy is used in buildings how much +more efficient and buildings be + + align:start position:0% +more efficient and buildings be + + + align:start position:0% +more efficient and buildings be +what specific activities in buildings + + align:start position:0% +what specific activities in buildings + + + align:start position:0% +what specific activities in buildings +lead to energy use and we will examine + + align:start position:0% +lead to energy use and we will examine + + + align:start position:0% +lead to energy use and we will examine +whether that leads to energy waste and + + align:start position:0% +whether that leads to energy waste and + + + align:start position:0% +whether that leads to energy waste and +finally how can we motivate individual + + align:start position:0% +finally how can we motivate individual + + + align:start position:0% +finally how can we motivate individual +users to save energy in buildings + + align:start position:0% +users to save energy in buildings + + + align:start position:0% +users to save energy in buildings +so + + align:start position:0% +so + + + align:start position:0% +so +just to highlight for a moment the role + + align:start position:0% +just to highlight for a moment the role + + + align:start position:0% +just to highlight for a moment the role +of buildings in the economy this is our + + align:start position:0% +of buildings in the economy this is our + + + align:start position:0% +of buildings in the economy this is our +familiar send key diagram the U.S energy + + align:start position:0% +familiar send key diagram the U.S energy + + + align:start position:0% +familiar send key diagram the U.S energy +economy being roughly about 97 quads if + + align:start position:0% +economy being roughly about 97 quads if + + + align:start position:0% +economy being roughly about 97 quads if +you look at the final uses here the + + align:start position:0% +you look at the final uses here the + + + align:start position:0% +you look at the final uses here the +final uses for buildings are generally + + align:start position:0% +final uses for buildings are generally + + + align:start position:0% +final uses for buildings are generally +categorized as residential and + + align:start position:0% +categorized as residential and + + + align:start position:0% +categorized as residential and +Commercial put together + + align:start position:0% +Commercial put together + + + align:start position:0% +Commercial put together +that's about 20 quads which means it's + + align:start position:0% +that's about 20 quads which means it's + + + align:start position:0% +that's about 20 quads which means it's +responsible for about 20 of the total + + align:start position:0% +responsible for about 20 of the total + + + align:start position:0% +responsible for about 20 of the total +energy going into the economy and about + + align:start position:0% +energy going into the economy and about + + + align:start position:0% +energy going into the economy and about +30 percent of our final uses if you take + + align:start position:0% +30 percent of our final uses if you take + + + align:start position:0% +30 percent of our final uses if you take +these two as a proportion of all the + + align:start position:0% +these two as a proportion of all the + + + align:start position:0% +these two as a proportion of all the +various pink boxes representing final + + align:start position:0% +various pink boxes representing final + + + align:start position:0% +various pink boxes representing final +consumption + + align:start position:0% +consumption + + + align:start position:0% +consumption +of course as a proportion of electricity + + align:start position:0% +of course as a proportion of electricity + + + align:start position:0% +of course as a proportion of electricity +use residential commercial buildings + + align:start position:0% +use residential commercial buildings + + + align:start position:0% +use residential commercial buildings +actually tend to use a much larger + + align:start position:0% +actually tend to use a much larger + + + align:start position:0% +actually tend to use a much larger +proportion of the energy it looks like + + align:start position:0% +proportion of the energy it looks like + + + align:start position:0% +proportion of the energy it looks like +north of 70 percent + + align:start position:0% +north of 70 percent + + + align:start position:0% +north of 70 percent +because industrial uses and + + align:start position:0% +because industrial uses and + + + align:start position:0% +because industrial uses and +transportation tend to use fossil fuels + + align:start position:0% +transportation tend to use fossil fuels + + + align:start position:0% +transportation tend to use fossil fuels +like petroleum and natural gas or oil + + align:start position:0% +like petroleum and natural gas or oil + + + align:start position:0% +like petroleum and natural gas or oil +so most electricity that we generate + + align:start position:0% +so most electricity that we generate + + + align:start position:0% +so most electricity that we generate +actually goes into buildings + + align:start position:0% +actually goes into buildings + + + align:start position:0% +actually goes into buildings +and just to highlight what the users + + align:start position:0% +and just to highlight what the users + + + align:start position:0% +and just to highlight what the users +uses of energy are in our buildings this + + align:start position:0% +uses of energy are in our buildings this + + + align:start position:0% +uses of energy are in our buildings this +is a Sankey diagram specifically for + + align:start position:0% +is a Sankey diagram specifically for + + + align:start position:0% +is a Sankey diagram specifically for +buildings specifically for commercial + + align:start position:0% +buildings specifically for commercial + + + align:start position:0% +buildings specifically for commercial +buildings and this is actually a + + align:start position:0% +buildings and this is actually a + + + align:start position:0% +buildings and this is actually a +relatively old report for Pacific + + align:start position:0% +relatively old report for Pacific + + + align:start position:0% +relatively old report for Pacific +Northwest National Labs but I'm guessing + + align:start position:0% +Northwest National Labs but I'm guessing + + + align:start position:0% +Northwest National Labs but I'm guessing +it hasn't changed too much over time and + + align:start position:0% +it hasn't changed too much over time and + + + align:start position:0% +it hasn't changed too much over time and +if you look at this we have input coal + + align:start position:0% +if you look at this we have input coal + + + align:start position:0% +if you look at this we have input coal +natural gas petroleum natural gas this + + align:start position:0% +natural gas petroleum natural gas this + + + align:start position:0% +natural gas petroleum natural gas this +is all going through Electric utilities + + align:start position:0% +is all going through Electric utilities + + + align:start position:0% +is all going through Electric utilities +and these arrows here in the bottom are + + align:start position:0% +and these arrows here in the bottom are + + + align:start position:0% +and these arrows here in the bottom are +natural gas petroleum and biomass going + + align:start position:0% +natural gas petroleum and biomass going + + + align:start position:0% +natural gas petroleum and biomass going +directly into the commercial building + + align:start position:0% +directly into the commercial building + + + align:start position:0% +directly into the commercial building +sector and you can see all the uses here + + align:start position:0% +sector and you can see all the uses here + + + align:start position:0% +sector and you can see all the uses here +on the right we will focus in on this + + align:start position:0% +on the right we will focus in on this + + + align:start position:0% +on the right we will focus in on this +further + + align:start position:0% +further + + + align:start position:0% +further +and if you look at what the total energy + + align:start position:0% +and if you look at what the total energy + + + align:start position:0% +and if you look at what the total energy +that's delivered to commercial customers + + align:start position:0% +that's delivered to commercial customers + + + align:start position:0% +that's delivered to commercial customers +is you can see that it's really a grab + + align:start position:0% +is you can see that it's really a grab + + + align:start position:0% +is you can see that it's really a grab +bag of many different energy uses how + + align:start position:0% +bag of many different energy uses how + + + align:start position:0% +bag of many different energy uses how +half of it looks like electricity half + + align:start position:0% +half of it looks like electricity half + + + align:start position:0% +half of it looks like electricity half +of it looks like fossil fuels that are + + align:start position:0% +of it looks like fossil fuels that are + + + align:start position:0% +of it looks like fossil fuels that are +busted directly on site + + align:start position:0% +busted directly on site + + + align:start position:0% +busted directly on site +you can see that a significant portion + + align:start position:0% +you can see that a significant portion + + + align:start position:0% +you can see that a significant portion +of the uses are for space cooling + + align:start position:0% +of the uses are for space cooling + + + align:start position:0% +of the uses are for space cooling +ventilation lighting Refrigeration + + align:start position:0% +ventilation lighting Refrigeration + + + align:start position:0% +ventilation lighting Refrigeration +office equipment and then all of most of + + align:start position:0% +office equipment and then all of most of + + + align:start position:0% +office equipment and then all of most of +our natural gas goes to do space heating + + align:start position:0% +our natural gas goes to do space heating + + + align:start position:0% +our natural gas goes to do space heating +water heating and other uses and some + + align:start position:0% +water heating and other uses and some + + + align:start position:0% +water heating and other uses and some +cooking the petroleum or coal is still + + align:start position:0% +cooking the petroleum or coal is still + + + align:start position:0% +cooking the petroleum or coal is still +used in many countries but less so in + + align:start position:0% +used in many countries but less so in + + + align:start position:0% +used in many countries but less so in +the United States is almost all entirely + + align:start position:0% +the United States is almost all entirely + + + align:start position:0% +the United States is almost all entirely +going to space Heating and water heating + + align:start position:0% +going to space Heating and water heating + + + align:start position:0% +going to space Heating and water heating +and then there's a portion of biomass + + align:start position:0% +and then there's a portion of biomass + + + align:start position:0% +and then there's a portion of biomass +that's essentially wood stoves which is + + align:start position:0% +that's essentially wood stoves which is + + + align:start position:0% +that's essentially wood stoves which is +this little sliver here and of course we + + align:start position:0% +this little sliver here and of course we + + + align:start position:0% +this little sliver here and of course we +have the smallest liver is unfortunately + + align:start position:0% +have the smallest liver is unfortunately + + + align:start position:0% +have the smallest liver is unfortunately +Renewables now but we hope to perhaps + + align:start position:0% +Renewables now but we hope to perhaps + + + align:start position:0% +Renewables now but we hope to perhaps +increase that as we have energy + + align:start position:0% +increase that as we have energy + + + align:start position:0% +increase that as we have energy +generation in homes occurring at a + + align:start position:0% +generation in homes occurring at a + + + align:start position:0% +generation in homes occurring at a +greater scale with rooftop solar + + align:start position:0% +greater scale with rooftop solar + + + align:start position:0% +greater scale with rooftop solar +if you look at the residential sector + + align:start position:0% +if you look at the residential sector + + + align:start position:0% +if you look at the residential sector +again we have electric utilities here at + + align:start position:0% +again we have electric utilities here at + + + align:start position:0% +again we have electric utilities here at +the top and we have elect Direct + + align:start position:0% +the top and we have elect Direct + + + align:start position:0% +the top and we have elect Direct +Delivery of fuels at the bottom and you + + align:start position:0% +Delivery of fuels at the bottom and you + + + align:start position:0% +Delivery of fuels at the bottom and you +can see if we focus in on residential + + align:start position:0% +can see if we focus in on residential + + + align:start position:0% +can see if we focus in on residential +buildings + + align:start position:0% +buildings + + + align:start position:0% +buildings +from this Pacific Northwest National lab + + align:start position:0% +from this Pacific Northwest National lab + + + align:start position:0% +from this Pacific Northwest National lab +report you can see again that there's + + align:start position:0% +report you can see again that there's + + + align:start position:0% +report you can see again that there's +many different activities occurring in + + align:start position:0% +many different activities occurring in + + + align:start position:0% +many different activities occurring in +buildings space heating cooling lighting + + align:start position:0% +buildings space heating cooling lighting + + + align:start position:0% +buildings space heating cooling lighting +Refrigeration so on + + align:start position:0% +Refrigeration so on + + + align:start position:0% +Refrigeration so on +all these are the same with wood solar + + align:start position:0% +all these are the same with wood solar + + + align:start position:0% +all these are the same with wood solar +is a larger portion of the energy use + + align:start position:0% +is a larger portion of the energy use + + + align:start position:0% +is a larger portion of the energy use +for residential buildings Thanos for + + align:start position:0% +for residential buildings Thanos for + + + align:start position:0% +for residential buildings Thanos for +commercial buildings + + align:start position:0% +commercial buildings + + + align:start position:0% +commercial buildings +but this is to point out that buildings + + align:start position:0% +but this is to point out that buildings + + + align:start position:0% +but this is to point out that buildings +are tightly integrated objects or tools + + align:start position:0% +are tightly integrated objects or tools + + + align:start position:0% +are tightly integrated objects or tools +that have basically been engineered for + + align:start position:0% +that have basically been engineered for + + + align:start position:0% +that have basically been engineered for +lots of different things they provide + + align:start position:0% +lots of different things they provide + + + align:start position:0% +lots of different things they provide +shelter they provide habitat they + + align:start position:0% +shelter they provide habitat they + + + align:start position:0% +shelter they provide habitat they +provide home this is where we do you + + align:start position:0% +provide home this is where we do you + + + align:start position:0% +provide home this is where we do you +know live work play after payment and so + + align:start position:0% +know live work play after payment and so + + + align:start position:0% +know live work play after payment and so +you know we have lots of different uses + + align:start position:0% +you know we have lots of different uses + + + align:start position:0% +you know we have lots of different uses +for trying to accomplish and what we + + align:start position:0% +for trying to accomplish and what we + + + align:start position:0% +for trying to accomplish and what we +want to do is also reduce the energy use + + align:start position:0% +want to do is also reduce the energy use + + + align:start position:0% +want to do is also reduce the energy use +or greenhouse gas emission footprint of + + align:start position:0% +or greenhouse gas emission footprint of + + + align:start position:0% +or greenhouse gas emission footprint of +this sector + + align:start position:0% +this sector + + + align:start position:0% +this sector +just to give you a final kind of sense + + align:start position:0% +just to give you a final kind of sense + + + align:start position:0% +just to give you a final kind of sense +of the importance of buildings if we + + align:start position:0% +of the importance of buildings if we + + + align:start position:0% +of the importance of buildings if we +look back at the Williams NL 2020 deep + + align:start position:0% +look back at the Williams NL 2020 deep + + + align:start position:0% +look back at the Williams NL 2020 deep +decarbonization Pathways or carbon + + align:start position:0% +decarbonization Pathways or carbon + + + align:start position:0% +decarbonization Pathways or carbon +neutral Pathways to the United States + + align:start position:0% +neutral Pathways to the United States + + + align:start position:0% +neutral Pathways to the United States +again we have this 2020 reference case + + align:start position:0% +again we have this 2020 reference case + + + align:start position:0% +again we have this 2020 reference case +this 2050 100 renewable case but if we + + align:start position:0% +this 2050 100 renewable case but if we + + + align:start position:0% +this 2050 100 renewable case but if we +want to achieve decarbonization from 100 + + align:start position:0% +want to achieve decarbonization from 100 + + + align:start position:0% +want to achieve decarbonization from 100 +Renewables we essentially need to + + align:start position:0% +Renewables we essentially need to + + + align:start position:0% +Renewables we essentially need to +decrease our electricity use by half + + align:start position:0% +decrease our electricity use by half + + + align:start position:0% +decrease our electricity use by half +that has to become much more efficient + + align:start position:0% +that has to become much more efficient + + + align:start position:0% +that has to become much more efficient +by use of heat pumps and other more + + align:start position:0% +by use of heat pumps and other more + + + align:start position:0% +by use of heat pumps and other more +efficient Technologies we essentially + + align:start position:0% +efficient Technologies we essentially + + + align:start position:0% +efficient Technologies we essentially +have to eliminate our use of natural gas + + align:start position:0% +have to eliminate our use of natural gas + + + align:start position:0% +have to eliminate our use of natural gas +pipeline into homes we need to actually + + align:start position:0% +pipeline into homes we need to actually + + + align:start position:0% +pipeline into homes we need to actually +increase our electricity + + align:start position:0% +increase our electricity + + + align:start position:0% +increase our electricity +biomass use through electricity mostly + + align:start position:0% +biomass use through electricity mostly + + + align:start position:0% +biomass use through electricity mostly +and again we have to make our homes much + + align:start position:0% +and again we have to make our homes much + + + align:start position:0% +and again we have to make our homes much +much more efficient or make our + + align:start position:0% +much more efficient or make our + + + align:start position:0% +much more efficient or make our +buildings much much more efficient + + align:start position:0% +buildings much much more efficient + + + align:start position:0% +buildings much much more efficient +but the key message to take home here is + + align:start position:0% +but the key message to take home here is + + + align:start position:0% +but the key message to take home here is +we actually have to use half as much + + align:start position:0% +we actually have to use half as much + + + align:start position:0% +we actually have to use half as much +energy and the half that we do use has + + align:start position:0% +energy and the half that we do use has + + + align:start position:0% +energy and the half that we do use has +to become much more efficient + + align:start position:0% +to become much more efficient + + + align:start position:0% +to become much more efficient +so just to give you a sense of how we + + align:start position:0% +so just to give you a sense of how we + + + align:start position:0% +so just to give you a sense of how we +actually lose energy to the environment + + align:start position:0% +actually lose energy to the environment + + + align:start position:0% +actually lose energy to the environment +why are we continually having to heat + + align:start position:0% +why are we continually having to heat + + + align:start position:0% +why are we continually having to heat +and cool our homes there's basically + + align:start position:0% +and cool our homes there's basically + + + align:start position:0% +and cool our homes there's basically +three ways that heat transfer occurs + + align:start position:0% +three ways that heat transfer occurs + + + align:start position:0% +three ways that heat transfer occurs +this is how our heating energy is lost + + align:start position:0% +this is how our heating energy is lost + + + align:start position:0% +this is how our heating energy is lost +or how we call our Heating and load + + align:start position:0% +or how we call our Heating and load + + + align:start position:0% +or how we call our Heating and load +there's three ways that we gain or lose + + align:start position:0% +there's three ways that we gain or lose + + + align:start position:0% +there's three ways that we gain or lose +heat from the house to the environment + + align:start position:0% +heat from the house to the environment + + + align:start position:0% +heat from the house to the environment +it's either ventilation through + + align:start position:0% +it's either ventilation through + + + align:start position:0% +it's either ventilation through +conduction infiltration which is air + + align:start position:0% +conduction infiltration which is air + + + align:start position:0% +conduction infiltration which is air +moving in and out essentially a drafty + + align:start position:0% +moving in and out essentially a drafty + + + align:start position:0% +moving in and out essentially a drafty +door or drafted window loses energy to + + align:start position:0% +door or drafted window loses energy to + + + align:start position:0% +door or drafted window loses energy to +the environment because our warm energy + + align:start position:0% +the environment because our warm energy + + + align:start position:0% +the environment because our warm energy +is being leaked out to the cool + + align:start position:0% +is being leaked out to the cool + + + align:start position:0% +is being leaked out to the cool +environment or if it's hot outside we're + + align:start position:0% +environment or if it's hot outside we're + + + align:start position:0% +environment or if it's hot outside we're +losing the energy we use to cool the air + + align:start position:0% +losing the energy we use to cool the air + + + align:start position:0% +losing the energy we use to cool the air +outside and equilibriates to the + + align:start position:0% +outside and equilibriates to the + + + align:start position:0% +outside and equilibriates to the +environment + + align:start position:0% +environment + + + align:start position:0% +environment +there's conduction which is where the + + align:start position:0% +there's conduction which is where the + + + align:start position:0% +there's conduction which is where the +heat actually is conducted out through + + align:start position:0% +heat actually is conducted out through + + + align:start position:0% +heat actually is conducted out through +materials molecules excite basically the + + align:start position:0% +materials molecules excite basically the + + + align:start position:0% +materials molecules excite basically the +neighboring molecules this is what + + align:start position:0% +neighboring molecules this is what + + + align:start position:0% +neighboring molecules this is what +happens to your external walls and the + + align:start position:0% +happens to your external walls and the + + + align:start position:0% +happens to your external walls and the +ground slab or the roof + + align:start position:0% +ground slab or the roof + + + align:start position:0% +ground slab or the roof +and then radiation this is essentially + + align:start position:0% +and then radiation this is essentially + + + align:start position:0% +and then radiation this is essentially +the process where we do gain some heat + + align:start position:0% +the process where we do gain some heat + + + align:start position:0% +the process where we do gain some heat +let's say from radiation being absorbed + + align:start position:0% +let's say from radiation being absorbed + + + align:start position:0% +let's say from radiation being absorbed +by homes but also we know in our houses + + align:start position:0% +by homes but also we know in our houses + + + align:start position:0% +by homes but also we know in our houses +are warmer than the environment they're + + align:start position:0% +are warmer than the environment they're + + + align:start position:0% +are warmer than the environment they're +radiating heat to the environment and + + align:start position:0% +radiating heat to the environment and + + + align:start position:0% +radiating heat to the environment and +there's a good newspaper that gives a + + align:start position:0% +there's a good newspaper that gives a + + + align:start position:0% +there's a good newspaper that gives a +detailed breakdown for some of these + + align:start position:0% +detailed breakdown for some of these + + + align:start position:0% +detailed breakdown for some of these +fundamental physical mechanisms if + + align:start position:0% +fundamental physical mechanisms if + + + align:start position:0% +fundamental physical mechanisms if +you're more interested in that + + align:start position:0% +you're more interested in that + + + align:start position:0% +you're more interested in that +and the key point that I like that like + + align:start position:0% +and the key point that I like that like + + + align:start position:0% +and the key point that I like that like +high makes is that conduction and + + align:start position:0% +high makes is that conduction and + + + align:start position:0% +high makes is that conduction and +ventilation depend on the temperature + + align:start position:0% +ventilation depend on the temperature + + + align:start position:0% +ventilation depend on the temperature +difference between inside and outside + + align:start position:0% +difference between inside and outside + + + align:start position:0% +difference between inside and outside +temperature our radiation depends on the + + align:start position:0% +temperature our radiation depends on the + + + align:start position:0% +temperature our radiation depends on the +area so you have this kind of basic + + align:start position:0% +area so you have this kind of basic + + + align:start position:0% +area so you have this kind of basic +breakdown of some of the factors + + align:start position:0% +breakdown of some of the factors + + + align:start position:0% +breakdown of some of the factors +involved conduction is area times a u + + align:start position:0% +involved conduction is area times a u + + + align:start position:0% +involved conduction is area times a u +value times the + + align:start position:0% +value times the + + + align:start position:0% +value times the +um difference in temperature times time + + align:start position:0% +um difference in temperature times time + + + align:start position:0% +um difference in temperature times time +ventilation is the volume times the rate + + align:start position:0% +ventilation is the volume times the rate + + + align:start position:0% +ventilation is the volume times the rate +I think that the volume is uh being + + align:start position:0% +I think that the volume is uh being + + + align:start position:0% +I think that the volume is uh being +moved out or sorry the a number of ways + + align:start position:0% +moved out or sorry the a number of ways + + + align:start position:0% +moved out or sorry the a number of ways +energy could be lost times delta T times + + align:start position:0% +energy could be lost times delta T times + + + align:start position:0% +energy could be lost times delta T times +time and radiation is area times solar + + align:start position:0% +time and radiation is area times solar + + + align:start position:0% +time and radiation is area times solar +density of course the way it's written + + align:start position:0% +density of course the way it's written + + + align:start position:0% +density of course the way it's written +here in Makai is to highlight the fact + + align:start position:0% +here in Makai is to highlight the fact + + + align:start position:0% +here in Makai is to highlight the fact +that induction and ventilation both + + align:start position:0% +that induction and ventilation both + + + align:start position:0% +that induction and ventilation both +depend on the delta T the Delta + + align:start position:0% +depend on the delta T the Delta + + + align:start position:0% +depend on the delta T the Delta +temperature times time + + align:start position:0% +temperature times time + + + align:start position:0% +temperature times time +and so this is how Makai basically + + align:start position:0% +and so this is how Makai basically + + + align:start position:0% +and so this is how Makai basically +breaks down how his house lost energy in + + align:start position:0% +breaks down how his house lost energy in + + + align:start position:0% +breaks down how his house lost energy in +2007 and how he tries to tackle this + + align:start position:0% +2007 and how he tries to tackle this + + + align:start position:0% +2007 and how he tries to tackle this +problem of Energy Efficiency he breaks + + align:start position:0% +problem of Energy Efficiency he breaks + + + align:start position:0% +problem of Energy Efficiency he breaks +down the horizontal surfaces to the + + align:start position:0% +down the horizontal surfaces to the + + + align:start position:0% +down the horizontal surfaces to the +roofs the floors vertical surfaces to + + align:start position:0% +roofs the floors vertical surfaces to + + + align:start position:0% +roofs the floors vertical surfaces to +the walls pin walls blade doors windows + + align:start position:0% +the walls pin walls blade doors windows + + + align:start position:0% +the walls pin walls blade doors windows +double blade windows and then calculates + + align:start position:0% +double blade windows and then calculates + + + align:start position:0% +double blade windows and then calculates +the leakiness and this is the number of + + align:start position:0% +the leakiness and this is the number of + + + align:start position:0% +the leakiness and this is the number of +air changes per hour so you can + + align:start position:0% +air changes per hour so you can + + + align:start position:0% +air changes per hour so you can +calculate the meters squared in terms of + + align:start position:0% +calculate the meters squared in terms of + + + align:start position:0% +calculate the meters squared in terms of +area the U value is a indication of the + + align:start position:0% +area the U value is a indication of the + + + align:start position:0% +area the U value is a indication of the +power transfer ending on difference in + + align:start position:0% +power transfer ending on difference in + + + align:start position:0% +power transfer ending on difference in +temperature so it's watts per meter + + align:start position:0% +temperature so it's watts per meter + + + align:start position:0% +temperature so it's watts per meter +Square divided by degrees Celsius and + + align:start position:0% +Square divided by degrees Celsius and + + + align:start position:0% +Square divided by degrees Celsius and +that gives us leakiness if we multiply + + align:start position:0% +that gives us leakiness if we multiply + + + align:start position:0% +that gives us leakiness if we multiply +area times U value of Watts which is the + + align:start position:0% +area times U value of Watts which is the + + + align:start position:0% +area times U value of Watts which is the +power being lost for every degree + + align:start position:0% +power being lost for every degree + + + align:start position:0% +power being lost for every degree +celsius difference + + align:start position:0% +celsius difference + + + align:start position:0% +celsius difference +and it was a ventilation we have the + + align:start position:0% +and it was a ventilation we have the + + + align:start position:0% +and it was a ventilation we have the +number of air changes per hour so we + + align:start position:0% +number of air changes per hour so we + + + align:start position:0% +number of air changes per hour so we +have a volume of 80 meters cubed in the + + align:start position:0% +have a volume of 80 meters cubed in the + + + align:start position:0% +have a volume of 80 meters cubed in the +bedrooms we want to change the air in + + align:start position:0% +bedrooms we want to change the air in + + + align:start position:0% +bedrooms we want to change the air in +there a half every per hour or change + + align:start position:0% +there a half every per hour or change + + + align:start position:0% +there a half every per hour or change +the entire room volume once every two + + align:start position:0% +the entire room volume once every two + + + align:start position:0% +the entire room volume once every two +hours and that gives us leakiness in + + align:start position:0% +hours and that gives us leakiness in + + + align:start position:0% +hours and that gives us leakiness in +terms of what herb degrees Celsius + + align:start position:0% +terms of what herb degrees Celsius + + + align:start position:0% +terms of what herb degrees Celsius +what Makai calculates is that the main + + align:start position:0% +what Makai calculates is that the main + + + align:start position:0% +what Makai calculates is that the main +way is that he loses heat in his house + + align:start position:0% +way is that he loses heat in his house + + + align:start position:0% +way is that he loses heat in his house +in Cambridge the UK which is similar to + + align:start position:0% +in Cambridge the UK which is similar to + + + align:start position:0% +in Cambridge the UK which is similar to +the climate of Boston that is losing + + align:start position:0% +the climate of Boston that is losing + + + align:start position:0% +the climate of Boston that is losing +about 78 percent of its energy through + + align:start position:0% +about 78 percent of its energy through + + + align:start position:0% +about 78 percent of its energy through +conduction and about 22 percent of its + + align:start position:0% +conduction and about 22 percent of its + + + align:start position:0% +conduction and about 22 percent of its +energy through ventilation changes + + align:start position:0% +energy through ventilation changes + + + align:start position:0% +energy through ventilation changes +and so what he does to try to reduce the + + align:start position:0% +and so what he does to try to reduce the + + + align:start position:0% +and so what he does to try to reduce the +energy loss of his house is to add + + align:start position:0% +energy loss of his house is to add + + + align:start position:0% +energy loss of his house is to add +cavity wall insulation he increases the + + align:start position:0% +cavity wall insulation he increases the + + + align:start position:0% +cavity wall insulation he increases the +roof insulation he adds a new storm door + + align:start position:0% +roof insulation he adds a new storm door + + + align:start position:0% +roof insulation he adds a new storm door +and he replaces the back door and window + + align:start position:0% +and he replaces the back door and window + + + align:start position:0% +and he replaces the back door and window +with double glazed windows I want to + + align:start position:0% +with double glazed windows I want to + + + align:start position:0% +with double glazed windows I want to +emphasize here that Energy Efficiency is + + align:start position:0% +emphasize here that Energy Efficiency is + + + align:start position:0% +emphasize here that Energy Efficiency is +not necessarily A high-tech Endeavor it + + align:start position:0% +not necessarily A high-tech Endeavor it + + + align:start position:0% +not necessarily A high-tech Endeavor it +can be a high-tech Endeavor but at the + + align:start position:0% +can be a high-tech Endeavor but at the + + + align:start position:0% +can be a high-tech Endeavor but at the +same time all these things that he does + + align:start position:0% +same time all these things that he does + + + align:start position:0% +same time all these things that he does +in 2007 are fairly simple things this is + + align:start position:0% +in 2007 are fairly simple things this is + + + align:start position:0% +in 2007 are fairly simple things this is +essentially a technology that you can + + align:start position:0% +essentially a technology that you can + + + align:start position:0% +essentially a technology that you can +acquire from your hardware store having + + align:start position:0% +acquire from your hardware store having + + + align:start position:0% +acquire from your hardware store having +said that there are startups that + + align:start position:0% +said that there are startups that + + + align:start position:0% +said that there are startups that +actually drive cars around like the + + align:start position:0% +actually drive cars around like the + + + align:start position:0% +actually drive cars around like the +Google cars that do street view and they + + align:start position:0% +Google cars that do street view and they + + + align:start position:0% +Google cars that do street view and they +actually measure the + + align:start position:0% +actually measure the + + + align:start position:0% +actually measure the +inductive and radiative losses of houses + + align:start position:0% +inductive and radiative losses of houses + + + align:start position:0% +inductive and radiative losses of houses +using infrared cameras or guns and so + + align:start position:0% +using infrared cameras or guns and so + + + align:start position:0% +using infrared cameras or guns and so +you can basically drive around and map + + align:start position:0% +you can basically drive around and map + + + align:start position:0% +you can basically drive around and map +out the city from the street and see + + align:start position:0% +out the city from the street and see + + + align:start position:0% +out the city from the street and see +where people lose energy and there's a + + align:start position:0% +where people lose energy and there's a + + + align:start position:0% +where people lose energy and there's a +number of energy startups I think that + + align:start position:0% +number of energy startups I think that + + + align:start position:0% +number of energy startups I think that +are trying to use that technology to try + + align:start position:0% +are trying to use that technology to try + + + align:start position:0% +are trying to use that technology to try +to identify homes that might be + + align:start position:0% +to identify homes that might be + + + align:start position:0% +to identify homes that might be +to essentially acquire a customer for + + align:start position:0% +to essentially acquire a customer for + + + align:start position:0% +to essentially acquire a customer for +Energy Efficiency + + align:start position:0% +Energy Efficiency + + + align:start position:0% +Energy Efficiency +so just to give you a sense of what's + + align:start position:0% +so just to give you a sense of what's + + + align:start position:0% +so just to give you a sense of what's +possible with Energy Efficiency measures + + align:start position:0% +possible with Energy Efficiency measures + + + align:start position:0% +possible with Energy Efficiency measures +now this is uh from a old report I think + + align:start position:0% +now this is uh from a old report I think + + + align:start position:0% +now this is uh from a old report I think +it's from one of the National Labs and + + align:start position:0% +it's from one of the National Labs and + + + align:start position:0% +it's from one of the National Labs and +this shows actually we have an R value + + align:start position:0% +this shows actually we have an R value + + + align:start position:0% +this shows actually we have an R value +which is a resistance value or one over + + align:start position:0% +which is a resistance value or one over + + + align:start position:0% +which is a resistance value or one over +the U value one over the leakiness + + align:start position:0% +the U value one over the leakiness + + + align:start position:0% +the U value one over the leakiness +and you can see that the Technologies + + align:start position:0% +and you can see that the Technologies + + + align:start position:0% +and you can see that the Technologies +here are basically net energy losers but + + align:start position:0% +here are basically net energy losers but + + + align:start position:0% +here are basically net energy losers but +they are decreasing amounts or + + align:start position:0% +they are decreasing amounts or + + + align:start position:0% +they are decreasing amounts or +increasing amounts of resistance over + + align:start position:0% +increasing amounts of resistance over + + + align:start position:0% +increasing amounts of resistance over +time starting 1970 going from 1990 we + + align:start position:0% +time starting 1970 going from 1990 we + + + align:start position:0% +time starting 1970 going from 1990 we +have very poor single pane windows we + + align:start position:0% +have very poor single pane windows we + + + align:start position:0% +have very poor single pane windows we +get a much better improvement from + + align:start position:0% +get a much better improvement from + + + align:start position:0% +get a much better improvement from +developing windows but we're getting to + + align:start position:0% +developing windows but we're getting to + + + align:start position:0% +developing windows but we're getting to +low e-windows super windows and super + + align:start position:0% +low e-windows super windows and super + + + align:start position:0% +low e-windows super windows and super +windows that are essentially net energy + + align:start position:0% +windows that are essentially net energy + + + align:start position:0% +windows that are essentially net energy +losers but we're decreasing how much + + align:start position:0% +losers but we're decreasing how much + + + align:start position:0% +losers but we're decreasing how much +we're losing in projected time I guess + + align:start position:0% +we're losing in projected time I guess + + + align:start position:0% +we're losing in projected time I guess +after the um in the last 10 years we're + + align:start position:0% +after the um in the last 10 years we're + + + align:start position:0% +after the um in the last 10 years we're +expected to get to a very high + + align:start position:0% +expected to get to a very high + + + align:start position:0% +expected to get to a very high +resistance super windows and so I'm not + + align:start position:0% +resistance super windows and so I'm not + + + align:start position:0% +resistance super windows and so I'm not +quite sure the current state of + + align:start position:0% +quite sure the current state of + + + align:start position:0% +quite sure the current state of +Technology but I suspect that we are + + align:start position:0% +Technology but I suspect that we are + + + align:start position:0% +Technology but I suspect that we are +well above where we were double paying + + align:start position:0% +well above where we were double paying + + + align:start position:0% +well above where we were double paying +with those + + align:start position:0% +with those + + + align:start position:0% +with those +and just to give you a sense of some of + + align:start position:0% +and just to give you a sense of some of + + + align:start position:0% +and just to give you a sense of some of +the r values included in a model model + + align:start position:0% +the r values included in a model model + + + align:start position:0% +the r values included in a model model +building code one area that's I've said + + align:start position:0% +building code one area that's I've said + + + align:start position:0% +building code one area that's I've said +too that local governments and cities + + align:start position:0% +too that local governments and cities + + + align:start position:0% +too that local governments and cities +can actually do a lot of work or you + + align:start position:0% +can actually do a lot of work or you + + + align:start position:0% +can actually do a lot of work or you +implement policies that actually change + + align:start position:0% +implement policies that actually change + + + align:start position:0% +implement policies that actually change +the building stock are there building + + align:start position:0% +the building stock are there building + + + align:start position:0% +the building stock are there building +codes all of our all of our buildings + + align:start position:0% +codes all of our all of our buildings + + + align:start position:0% +codes all of our all of our buildings +have to be built to a fire code and + + align:start position:0% +have to be built to a fire code and + + + align:start position:0% +have to be built to a fire code and +electrical code in the places that have + + align:start position:0% +electrical code in the places that have + + + align:start position:0% +electrical code in the places that have +earthquakes a seismic code these are the + + align:start position:0% +earthquakes a seismic code these are the + + + align:start position:0% +earthquakes a seismic code these are the +fundamental codes that govern how our + + align:start position:0% +fundamental codes that govern how our + + + align:start position:0% +fundamental codes that govern how our +buildings are built in Florida after + + align:start position:0% +buildings are built in Florida after + + + align:start position:0% +buildings are built in Florida after +Hurricane Andrew 1992 it actually + + align:start position:0% +Hurricane Andrew 1992 it actually + + + align:start position:0% +Hurricane Andrew 1992 it actually +developed some of the strongest building + + align:start position:0% +developed some of the strongest building + + + align:start position:0% +developed some of the strongest building +codes in the country because the + + align:start position:0% +codes in the country because the + + + align:start position:0% +codes in the country because the +hurricane revealed that relatively + + align:start position:0% +hurricane revealed that relatively + + + align:start position:0% +hurricane revealed that relatively +simple interventions in the building + + align:start position:0% +simple interventions in the building + + + align:start position:0% +simple interventions in the building +code would result in much better and + + align:start position:0% +code would result in much better and + + + align:start position:0% +code would result in much better and +stronger homes + + align:start position:0% +stronger homes + + + align:start position:0% +stronger homes +but this is also a key area where local + + align:start position:0% +but this is also a key area where local + + + align:start position:0% +but this is also a key area where local +governments and cities have jurisdiction + + align:start position:0% +governments and cities have jurisdiction + + + align:start position:0% +governments and cities have jurisdiction +they are allowed to actually Implement + + align:start position:0% +they are allowed to actually Implement + + + align:start position:0% +they are allowed to actually Implement +building codes in a way that the state + + align:start position:0% +building codes in a way that the state + + + align:start position:0% +building codes in a way that the state +and federal governments cannot so just + + align:start position:0% +and federal governments cannot so just + + + align:start position:0% +and federal governments cannot so just +to give you a sense of the r values in + + align:start position:0% +to give you a sense of the r values in + + + align:start position:0% +to give you a sense of the r values in +model buildings based on what two + + align:start position:0% +model buildings based on what two + + + align:start position:0% +model buildings based on what two +International energy conservation codes + + align:start position:0% +International energy conservation codes + + + align:start position:0% +International energy conservation codes +require there's a there's a code from + + align:start position:0% +require there's a there's a code from + + + align:start position:0% +require there's a there's a code from +2000 there's an upgraded code in 2012 + + align:start position:0% +2000 there's an upgraded code in 2012 + + + align:start position:0% +2000 there's an upgraded code in 2012 +and there's proposed changes further + + align:start position:0% +and there's proposed changes further + + + align:start position:0% +and there's proposed changes further +this has been a key area of research in + + align:start position:0% +this has been a key area of research in + + + align:start position:0% +this has been a key area of research in +the last 10 or 12 years the federal + + align:start position:0% +the last 10 or 12 years the federal + + + align:start position:0% +the last 10 or 12 years the federal +government since the era stimulus and + + align:start position:0% +government since the era stimulus and + + + align:start position:0% +government since the era stimulus and +the Obama Administration has pushed + + align:start position:0% +the Obama Administration has pushed + + + align:start position:0% +the Obama Administration has pushed +building codes very hard to improve very + + align:start position:0% +building codes very hard to improve very + + + align:start position:0% +building codes very hard to improve very +quickly so you can see that the r values + + align:start position:0% +quickly so you can see that the r values + + + align:start position:0% +quickly so you can see that the r values +of ceilings have essentially doubled + + align:start position:0% +of ceilings have essentially doubled + + + align:start position:0% +of ceilings have essentially doubled +from 2000 to the proposed code from this + + align:start position:0% +from 2000 to the proposed code from this + + + align:start position:0% +from 2000 to the proposed code from this +golbossier access paper + + align:start position:0% +golbossier access paper + + + align:start position:0% +golbossier access paper +you can see that above ground walls have + + align:start position:0% +you can see that above ground walls have + + + align:start position:0% +you can see that above ground walls have +essentially tripled in the resistance to + + align:start position:0% +essentially tripled in the resistance to + + + align:start position:0% +essentially tripled in the resistance to +heat losses basement walls have + + align:start position:0% +heat losses basement walls have + + + align:start position:0% +heat losses basement walls have +essentially doubled floors have doubled + + align:start position:0% +essentially doubled floors have doubled + + + align:start position:0% +essentially doubled floors have doubled +roofs have doubles and mass walls have + + align:start position:0% +roofs have doubles and mass walls have + + + align:start position:0% +roofs have doubles and mass walls have +developed a code value for the first + + align:start position:0% +developed a code value for the first + + + align:start position:0% +developed a code value for the first +time these are all ways that when the + + align:start position:0% +time these are all ways that when the + + + align:start position:0% +time these are all ways that when the +local government simply specifies you + + align:start position:0% +local government simply specifies you + + + align:start position:0% +local government simply specifies you +have to build the standard that the + + align:start position:0% +have to build the standard that the + + + align:start position:0% +have to build the standard that the +local development industry and + + align:start position:0% +local development industry and + + + align:start position:0% +local development industry and +contractors have to respond to that + + align:start position:0% +contractors have to respond to that + + + align:start position:0% +contractors have to respond to that +so this is why I had you calculate 15 + + align:start position:0% +so this is why I had you calculate 15 + + + align:start position:0% +so this is why I had you calculate 15 +degree days in the problem set if you + + align:start position:0% +degree days in the problem set if you + + + align:start position:0% +degree days in the problem set if you +look at makai's house he shows that in + + align:start position:0% +look at makai's house he shows that in + + + align:start position:0% +look at makai's house he shows that in +Cambridge which again is similar to the + + align:start position:0% +Cambridge which again is similar to the + + + align:start position:0% +Cambridge which again is similar to the +climate of Boston for the most of the + + align:start position:0% +climate of Boston for the most of the + + + align:start position:0% +climate of Boston for the most of the +year you can see that he's doing Heating + + align:start position:0% +year you can see that he's doing Heating + + + align:start position:0% +year you can see that he's doing Heating +in his house he has 3 200 Degree Days of + + align:start position:0% +in his house he has 3 200 Degree Days of + + + align:start position:0% +in his house he has 3 200 Degree Days of +heating and about 91 degrees of cooling + + align:start position:0% +heating and about 91 degrees of cooling + + + align:start position:0% +heating and about 91 degrees of cooling +required if you look at + + align:start position:0% +required if you look at + + + align:start position:0% +required if you look at +um I think what happens after his Energy + + align:start position:0% +um I think what happens after his Energy + + + align:start position:0% +um I think what happens after his Energy +Efficiency installations he goes to + + align:start position:0% +Efficiency installations he goes to + + + align:start position:0% +Efficiency installations he goes to +about 22 or 2300 degrees days of heating + + align:start position:0% +about 22 or 2300 degrees days of heating + + + align:start position:0% +about 22 or 2300 degrees days of heating +and is unaffected by cooling but this is + + align:start position:0% +and is unaffected by cooling but this is + + + align:start position:0% +and is unaffected by cooling but this is +to say that if you simply change the + + align:start position:0% +to say that if you simply change the + + + align:start position:0% +to say that if you simply change the +base temperature which is what I did + + align:start position:0% +base temperature which is what I did + + + align:start position:0% +base temperature which is what I did +what you did the problem set you can + + align:start position:0% +what you did the problem set you can + + + align:start position:0% +what you did the problem set you can +actually reduce how much time is heating + + align:start position:0% +actually reduce how much time is heating + + + align:start position:0% +actually reduce how much time is heating +which is to say that we measure + + align:start position:0% +which is to say that we measure + + + align:start position:0% +which is to say that we measure +everything against the temperature we'd + + align:start position:0% +everything against the temperature we'd + + + align:start position:0% +everything against the temperature we'd +like to keep our indoor temperature at + + align:start position:0% +like to keep our indoor temperature at + + + align:start position:0% +like to keep our indoor temperature at +so this looks like around 65 degrees and + + align:start position:0% +so this looks like around 65 degrees and + + + align:start position:0% +so this looks like around 65 degrees and +this is about 2 degrees Celsius lower + + align:start position:0% +this is about 2 degrees Celsius lower + + + align:start position:0% +this is about 2 degrees Celsius lower +and you simply change the thermostat + + align:start position:0% +and you simply change the thermostat + + + align:start position:0% +and you simply change the thermostat +setting what you're trying you target + + align:start position:0% +setting what you're trying you target + + + align:start position:0% +setting what you're trying you target +for maintaining indoor temperature you + + align:start position:0% +for maintaining indoor temperature you + + + align:start position:0% +for maintaining indoor temperature you +can actually significantly decrease the + + align:start position:0% +can actually significantly decrease the + + + align:start position:0% +can actually significantly decrease the +amount of heating or cooling required to + + align:start position:0% +amount of heating or cooling required to + + + align:start position:0% +amount of heating or cooling required to +make up that heat loss remember that we + + align:start position:0% +make up that heat loss remember that we + + + align:start position:0% +make up that heat loss remember that we +looked at conduction and radiation + + align:start position:0% +looked at conduction and radiation + + + align:start position:0% +looked at conduction and radiation +dependent on the delta T times time if + + align:start position:0% +dependent on the delta T times time if + + + align:start position:0% +dependent on the delta T times time if +we change simply the delta T that we're + + align:start position:0% +we change simply the delta T that we're + + + align:start position:0% +we change simply the delta T that we're +trying to eat or cool to that we can + + align:start position:0% +trying to eat or cool to that we can + + + align:start position:0% +trying to eat or cool to that we can +reduce a lot of our Heating and Cooling + + align:start position:0% +reduce a lot of our Heating and Cooling + + + align:start position:0% +reduce a lot of our Heating and Cooling +energy use + + align:start position:0% +energy use + + + align:start position:0% +energy use +this is also why there's a very large + + align:start position:0% +this is also why there's a very large + + + align:start position:0% +this is also why there's a very large +push on heat pumps this is a diagram + + align:start position:0% +push on heat pumps this is a diagram + + + align:start position:0% +push on heat pumps this is a diagram +from a book from Randolph and Masters + + align:start position:0% +from a book from Randolph and Masters + + + align:start position:0% +from a book from Randolph and Masters +I mean basically have this very simple + + align:start position:0% +I mean basically have this very simple + + + align:start position:0% +I mean basically have this very simple +diagram that I like it basically shows + + align:start position:0% +diagram that I like it basically shows + + + align:start position:0% +diagram that I like it basically shows +how refrigerator acts as an air + + align:start position:0% +how refrigerator acts as an air + + + align:start position:0% +how refrigerator acts as an air +conditioner but it heats the world where + + align:start position:0% +conditioner but it heats the world where + + + align:start position:0% +conditioner but it heats the world where +air conditioning the space inside a + + align:start position:0% +air conditioning the space inside a + + + align:start position:0% +air conditioning the space inside a +refrigerator and the back of your + + align:start position:0% +refrigerator and the back of your + + + align:start position:0% +refrigerator and the back of your +refrigerator is rejecting heat of course + + align:start position:0% +refrigerator is rejecting heat of course + + + align:start position:0% +refrigerator is rejecting heat of course +we can flip this thing around and we + + align:start position:0% +we can flip this thing around and we + + + align:start position:0% +we can flip this thing around and we +could actually heat cool the outside + + align:start position:0% +could actually heat cool the outside + + + align:start position:0% +could actually heat cool the outside +world and keep the inside of our house + + align:start position:0% +world and keep the inside of our house + + + align:start position:0% +world and keep the inside of our house +this is essentially how a heat pump + + align:start position:0% +this is essentially how a heat pump + + + align:start position:0% +this is essentially how a heat pump +works it's the same thing as a + + align:start position:0% +works it's the same thing as a + + + align:start position:0% +works it's the same thing as a +refrigerator the same thing as an air + + align:start position:0% +refrigerator the same thing as an air + + + align:start position:0% +refrigerator the same thing as an air +conditioner but the key difference in a + + align:start position:0% +conditioner but the key difference in a + + + align:start position:0% +conditioner but the key difference in a +heat pump is you can operate it both + + align:start position:0% +heat pump is you can operate it both + + + align:start position:0% +heat pump is you can operate it both +directions I think I told you the story + + align:start position:0% +directions I think I told you the story + + + align:start position:0% +directions I think I told you the story +before of research I did in Brazil that + + align:start position:0% +before of research I did in Brazil that + + + align:start position:0% +before of research I did in Brazil that +looked at electricity use in informal + + align:start position:0% +looked at electricity use in informal + + + align:start position:0% +looked at electricity use in informal +settlements and informal settlement log + + align:start position:0% +settlements and informal settlement log + + + align:start position:0% +settlements and informal settlement log +tool don't pay for their electricity use + + align:start position:0% +tool don't pay for their electricity use + + + align:start position:0% +tool don't pay for their electricity use +40 of all electricity in Brazil is + + align:start position:0% +40 of all electricity in Brazil is + + + align:start position:0% +40 of all electricity in Brazil is +unpaid for or stolen from the grid and + + align:start position:0% +unpaid for or stolen from the grid and + + + align:start position:0% +unpaid for or stolen from the grid and +so people actually have very little + + align:start position:0% +so people actually have very little + + + align:start position:0% +so people actually have very little +incentive to save energy so people use + + align:start position:0% +incentive to save energy so people use + + + align:start position:0% +incentive to save energy so people use +their refrigerators not only to store + + align:start position:0% +their refrigerators not only to store + + + align:start position:0% +their refrigerators not only to store +food or to even cool their home because + + align:start position:0% +food or to even cool their home because + + + align:start position:0% +food or to even cool their home because +they can just leave the doors open but + + align:start position:0% +they can just leave the doors open but + + + align:start position:0% +they can just leave the doors open but +people actually use refrigerators to dry + + align:start position:0% +people actually use refrigerators to dry + + + align:start position:0% +people actually use refrigerators to dry +clothes they put dry clothes on the hot + + align:start position:0% +clothes they put dry clothes on the hot + + + align:start position:0% +clothes they put dry clothes on the hot +condenser on the back or the heating + + align:start position:0% +condenser on the back or the heating + + + align:start position:0% +condenser on the back or the heating +cool coils or the radiating heat fins + + align:start position:0% +cool coils or the radiating heat fins + + + align:start position:0% +cool coils or the radiating heat fins +and that those actually radiate heat and + + align:start position:0% +and that those actually radiate heat and + + + align:start position:0% +and that those actually radiate heat and +they use them to dry clothes sometimes + + align:start position:0% +they use them to dry clothes sometimes + + + align:start position:0% +they use them to dry clothes sometimes +so there's been a very large push in + + align:start position:0% +so there's been a very large push in + + + align:start position:0% +so there's been a very large push in +policy now to use heat pumps because + + align:start position:0% +policy now to use heat pumps because + + + align:start position:0% +policy now to use heat pumps because +unlike burning fuels correctly you + + align:start position:0% +unlike burning fuels correctly you + + + align:start position:0% +unlike burning fuels correctly you +actually get about four times more + + align:start position:0% +actually get about four times more + + + align:start position:0% +actually get about four times more +energy uh rather four times the heating + + align:start position:0% +energy uh rather four times the heating + + + align:start position:0% +energy uh rather four times the heating +or cooling effect for the same unit of + + align:start position:0% +or cooling effect for the same unit of + + + align:start position:0% +or cooling effect for the same unit of +energy in a heat pump as the Makai book + + align:start position:0% +energy in a heat pump as the Makai book + + + align:start position:0% +energy in a heat pump as the Makai book +explains why heat pumps are uh what + + align:start position:0% +explains why heat pumps are uh what + + + align:start position:0% +explains why heat pumps are uh what +we're talking about in terms of why + + align:start position:0% +we're talking about in terms of why + + + align:start position:0% +we're talking about in terms of why +we're generating more Heating and + + align:start position:0% +we're generating more Heating and + + + align:start position:0% +we're generating more Heating and +Cooling energy has to do with entropy + + align:start position:0% +Cooling energy has to do with entropy + + + align:start position:0% +Cooling energy has to do with entropy +Makai book goes into more detail if + + align:start position:0% +Makai book goes into more detail if + + + align:start position:0% +Makai book goes into more detail if +you're interested in that + + align:start position:0% +you're interested in that + + + align:start position:0% +you're interested in that +to kind of emphasize why we are trying + + align:start position:0% +to kind of emphasize why we are trying + + + align:start position:0% +to kind of emphasize why we are trying +to treat our climate I think + + align:start position:0% +to treat our climate I think + + + align:start position:0% +to treat our climate I think +instinctively we know that the United + + align:start position:0% +instinctively we know that the United + + + align:start position:0% +instinctively we know that the United +States is defined as quite different + + align:start position:0% +States is defined as quite different + + + align:start position:0% +States is defined as quite different +assignment zones we have a marine zone + + align:start position:0% +assignment zones we have a marine zone + + + align:start position:0% +assignment zones we have a marine zone +or almost Mediterranean Zone on the west + + align:start position:0% +or almost Mediterranean Zone on the west + + + align:start position:0% +or almost Mediterranean Zone on the west +coast we have our very hot dry or mixed + + align:start position:0% +coast we have our very hot dry or mixed + + + align:start position:0% +coast we have our very hot dry or mixed +dry environment we have cold or very + + align:start position:0% +dry environment we have cold or very + + + align:start position:0% +dry environment we have cold or very +cold environment that we're in the Upper + + align:start position:0% +cold environment that we're in the Upper + + + align:start position:0% +cold environment that we're in the Upper +Midwest upper west and New England we + + align:start position:0% +Midwest upper west and New England we + + + align:start position:0% +Midwest upper west and New England we +have a mixed humid climate and we have a + + align:start position:0% +have a mixed humid climate and we have a + + + align:start position:0% +have a mixed humid climate and we have a +hot human planet + + align:start position:0% +hot human planet + + + align:start position:0% +hot human planet +the reason why this matters for building + + align:start position:0% +the reason why this matters for building + + + align:start position:0% +the reason why this matters for building +design or building engineering is that + + align:start position:0% +design or building engineering is that + + + align:start position:0% +design or building engineering is that +Engineers actually use charts that are + + align:start position:0% +Engineers actually use charts that are + + + align:start position:0% +Engineers actually use charts that are +called psychometric charts and those are + + align:start position:0% +called psychometric charts and those are + + + align:start position:0% +called psychometric charts and those are +charts that actually detail how + + align:start position:0% +charts that actually detail how + + + align:start position:0% +charts that actually detail how +comfortable people feel in mixes of + + align:start position:0% +comfortable people feel in mixes of + + + align:start position:0% +comfortable people feel in mixes of +humidity and temperature + + align:start position:0% +humidity and temperature + + + align:start position:0% +humidity and temperature +so the reason why we look at these + + align:start position:0% +so the reason why we look at these + + + align:start position:0% +so the reason why we look at these +different climate zones is that we know + + align:start position:0% +different climate zones is that we know + + + align:start position:0% +different climate zones is that we know +our energy use is closely related to the + + align:start position:0% +our energy use is closely related to the + + + align:start position:0% +our energy use is closely related to the +humidity and temperature of the outdoor + + align:start position:0% +humidity and temperature of the outdoor + + + align:start position:0% +humidity and temperature of the outdoor +environment and that's what our + + align:start position:0% +environment and that's what our + + + align:start position:0% +environment and that's what our +buildings are trying to correct for so + + align:start position:0% +buildings are trying to correct for so + + + align:start position:0% +buildings are trying to correct for so +we know that in hot humid environments + + align:start position:0% +we know that in hot humid environments + + + align:start position:0% +we know that in hot humid environments +or hot dry environments we use much more + + align:start position:0% +or hot dry environments we use much more + + + align:start position:0% +or hot dry environments we use much more +air conditioning we may use + + align:start position:0% +air conditioning we may use + + + align:start position:0% +air conditioning we may use +dehumidifiers or air conditioners may + + align:start position:0% +dehumidifiers or air conditioners may + + + align:start position:0% +dehumidifiers or air conditioners may +have to work differently to account for + + align:start position:0% +have to work differently to account for + + + align:start position:0% +have to work differently to account for +this humid environment + + align:start position:0% +this humid environment + + + align:start position:0% +this humid environment +uh the US eia also it defines these + + align:start position:0% +uh the US eia also it defines these + + + align:start position:0% +uh the US eia also it defines these +climate zones in slightly different ways + + align:start position:0% +climate zones in slightly different ways + + + align:start position:0% +climate zones in slightly different ways +but you can see here on the bottom they + + align:start position:0% +but you can see here on the bottom they + + + align:start position:0% +but you can see here on the bottom they +Define their zones in terms of how many + + align:start position:0% +Define their zones in terms of how many + + + align:start position:0% +Define their zones in terms of how many +cooling Degree Days how many heating + + align:start position:0% +cooling Degree Days how many heating + + + align:start position:0% +cooling Degree Days how many heating +Degree Days our buildings use + + align:start position:0% +Degree Days our buildings use + + + align:start position:0% +Degree Days our buildings use +these numbers actually factor into how + + align:start position:0% +these numbers actually factor into how + + + align:start position:0% +these numbers actually factor into how +we measure energy star ratings on + + align:start position:0% +we measure energy star ratings on + + + align:start position:0% +we measure energy star ratings on +buildings because we rate buildings + + align:start position:0% +buildings because we rate buildings + + + align:start position:0% +buildings because we rate buildings +according to how effectively their + + align:start position:0% +according to how effectively their + + + align:start position:0% +according to how effectively their +heating or cooling relative to the + + align:start position:0% +heating or cooling relative to the + + + align:start position:0% +heating or cooling relative to the +environment but we also know that our + + align:start position:0% +environment but we also know that our + + + align:start position:0% +environment but we also know that our +commercial buildings for energy star are + + align:start position:0% +commercial buildings for energy star are + + + align:start position:0% +commercial buildings for energy star are +located in many different environments + + align:start position:0% +located in many different environments + + + align:start position:0% +located in many different environments +so we try to score them differently + + align:start position:0% +so we try to score them differently + + + align:start position:0% +so we try to score them differently +so just to show you the reason why I had + + align:start position:0% +so just to show you the reason why I had + + + align:start position:0% +so just to show you the reason why I had +you look at your appliances briefly is + + align:start position:0% +you look at your appliances briefly is + + + align:start position:0% +you look at your appliances briefly is +that Makai estimates the loads from + + align:start position:0% +that Makai estimates the loads from + + + align:start position:0% +that Makai estimates the loads from +various selected appliances and you can + + align:start position:0% +various selected appliances and you can + + + align:start position:0% +various selected appliances and you can +see it's a pretty simple calculation we + + align:start position:0% +see it's a pretty simple calculation we + + + align:start position:0% +see it's a pretty simple calculation we +have these different categories cooking + + align:start position:0% +have these different categories cooking + + + align:start position:0% +have these different categories cooking +cleaning and cooling they have a power + + align:start position:0% +cleaning and cooling they have a power + + + align:start position:0% +cleaning and cooling they have a power +use which is kilowatts or joules per + + align:start position:0% +use which is kilowatts or joules per + + + align:start position:0% +use which is kilowatts or joules per +second we simply multiply times a unit + + align:start position:0% +second we simply multiply times a unit + + + align:start position:0% +second we simply multiply times a unit +of time here hours and then we get + + align:start position:0% +of time here hours and then we get + + + align:start position:0% +of time here hours and then we get +kilowatt hours which are a measure of + + align:start position:0% +kilowatt hours which are a measure of + + + align:start position:0% +kilowatt hours which are a measure of +energy per person per day and so we just + + align:start position:0% +energy per person per day and so we just + + + align:start position:0% +energy per person per day and so we just +multiply a spreadsheet you can see that + + align:start position:0% +multiply a spreadsheet you can see that + + + align:start position:0% +multiply a spreadsheet you can see that +the largest users of energy are the + + align:start position:0% +the largest users of energy are the + + + align:start position:0% +the largest users of energy are the +tumble dryer the freezer the electric + + align:start position:0% +tumble dryer the freezer the electric + + + align:start position:0% +tumble dryer the freezer the electric +oven and the electric cooker + + align:start position:0% +oven and the electric cooker + + + align:start position:0% +oven and the electric cooker +you can see it on an annual basis for + + align:start position:0% +you can see it on an annual basis for + + + align:start position:0% +you can see it on an annual basis for +two people you get to about 4 500 + + align:start position:0% +two people you get to about 4 500 + + + align:start position:0% +two people you get to about 4 500 +kilowatt hours per person per year + + align:start position:0% +kilowatt hours per person per year + + + align:start position:0% +kilowatt hours per person per year +that's actually relatively low I think + + align:start position:0% +that's actually relatively low I think + + + align:start position:0% +that's actually relatively low I think +in the US the average household uses + + align:start position:0% +in the US the average household uses + + + align:start position:0% +in the US the average household uses +about 14 + + align:start position:0% +about 14 + + + align:start position:0% +about 14 +000 kilowatt hours per person per year + + align:start position:0% +000 kilowatt hours per person per year + + + align:start position:0% +000 kilowatt hours per person per year +so you can see the average electricity + + align:start position:0% +so you can see the average electricity + + + align:start position:0% +so you can see the average electricity +consumption in the United Kingdom and + + align:start position:0% +consumption in the United Kingdom and + + + align:start position:0% +consumption in the United Kingdom and +Tanzania are relatively lower one reason + + align:start position:0% +Tanzania are relatively lower one reason + + + align:start position:0% +Tanzania are relatively lower one reason +for that might be that makai's house has + + align:start position:0% +for that might be that makai's house has + + + align:start position:0% +for that might be that makai's house has +a party wall built quite densely it's a + + align:start position:0% +a party wall built quite densely it's a + + + align:start position:0% +a party wall built quite densely it's a +relatively small home by American + + align:start position:0% +relatively small home by American + + + align:start position:0% +relatively small home by American +Standards + + align:start position:0% +Standards + + + align:start position:0% +Standards +so just to show you what some of the + + align:start position:0% +so just to show you what some of the + + + align:start position:0% +so just to show you what some of the +Technologies are that might help us + + align:start position:0% +Technologies are that might help us + + + align:start position:0% +Technologies are that might help us +understand how we use energy in + + align:start position:0% +understand how we use energy in + + + align:start position:0% +understand how we use energy in +buildings I'm going to show you some of + + align:start position:0% +buildings I'm going to show you some of + + + align:start position:0% +buildings I'm going to show you some of +the + + align:start position:0% +the + + + align:start position:0% +the +um devices I use to manage my own home + + align:start position:0% +um devices I use to manage my own home + + + align:start position:0% +um devices I use to manage my own home +mostly out of interest and because I + + align:start position:0% +mostly out of interest and because I + + + align:start position:0% +mostly out of interest and because I +like to show students every year with + + align:start position:0% +like to show students every year with + + + align:start position:0% +like to show students every year with +some of these different Technologies + + align:start position:0% +some of these different Technologies + + + align:start position:0% +some of these different Technologies +look like + + align:start position:0% +look like + + + align:start position:0% +look like +okay so just to show you what some of + + align:start position:0% +okay so just to show you what some of + + + align:start position:0% +okay so just to show you what some of +these Technologies I use to match my + + align:start position:0% +these Technologies I use to match my + + + align:start position:0% +these Technologies I use to match my +home look like + + align:start position:0% +home look like + + + align:start position:0% +home look like +I'm going to show you + + align:start position:0% +I'm going to show you + + + align:start position:0% +I'm going to show you +this is a sense monitor this is actually + + align:start position:0% +this is a sense monitor this is actually + + + align:start position:0% +this is a sense monitor this is actually +a small monitor that I installed in my + + align:start position:0% +a small monitor that I installed in my + + + align:start position:0% +a small monitor that I installed in my +electrical panel box and it basically + + align:start position:0% +electrical panel box and it basically + + + align:start position:0% +electrical panel box and it basically +measures the entire energy use going + + align:start position:0% +measures the entire energy use going + + + align:start position:0% +measures the entire energy use going +from the electrical grid into my house + + align:start position:0% +from the electrical grid into my house + + + align:start position:0% +from the electrical grid into my house +you can see this is a typical day from + + align:start position:0% +you can see this is a typical day from + + + align:start position:0% +you can see this is a typical day from +6am to about midnight and you can see + + align:start position:0% +6am to about midnight and you can see + + + align:start position:0% +6am to about midnight and you can see +several different things happening a + + align:start position:0% +several different things happening a + + + align:start position:0% +several different things happening a +first energy use is pretty low and + + align:start position:0% +first energy use is pretty low and + + + align:start position:0% +first energy use is pretty low and +morning before we wake up other measure + + align:start position:0% +morning before we wake up other measure + + + align:start position:0% +morning before we wake up other measure +as you can see when I'm moving here is + + align:start position:0% +as you can see when I'm moving here is + + + align:start position:0% +as you can see when I'm moving here is +the current meter this measures 500 + + align:start position:0% +the current meter this measures 500 + + + align:start position:0% +the current meter this measures 500 +watts going to the house you see these + + align:start position:0% +watts going to the house you see these + + + align:start position:0% +watts going to the house you see these +occasional small Cycles that's probably + + align:start position:0% +occasional small Cycles that's probably + + + align:start position:0% +occasional small Cycles that's probably +the refrigerator cycling just keep the + + align:start position:0% +the refrigerator cycling just keep the + + + align:start position:0% +the refrigerator cycling just keep the +food cool and then we wake up and we + + align:start position:0% +food cool and then we wake up and we + + + align:start position:0% +food cool and then we wake up and we +start running all our appliances things + + align:start position:0% +start running all our appliances things + + + align:start position:0% +start running all our appliances things +go very high that could be the tumble + + align:start position:0% +go very high that could be the tumble + + + align:start position:0% +go very high that could be the tumble +dryer coming out in the morning it could + + align:start position:0% +dryer coming out in the morning it could + + + align:start position:0% +dryer coming out in the morning it could +be a hair dryer coming on and then this + + align:start position:0% +be a hair dryer coming on and then this + + + align:start position:0% +be a hair dryer coming on and then this +is probably a dishwasher load that we + + align:start position:0% +is probably a dishwasher load that we + + + align:start position:0% +is probably a dishwasher load that we +set when I leave for work you can see + + align:start position:0% +set when I leave for work you can see + + + align:start position:0% +set when I leave for work you can see +throughout the day when we're away at + + align:start position:0% +throughout the day when we're away at + + + align:start position:0% +throughout the day when we're away at +work or school our energy use quite low + + align:start position:0% +work or school our energy use quite low + + + align:start position:0% +work or school our energy use quite low +again these are refrigerator cycling + + align:start position:0% +again these are refrigerator cycling + + + align:start position:0% +again these are refrigerator cycling +going through and then you can see we + + align:start position:0% +going through and then you can see we + + + align:start position:0% +going through and then you can see we +get home around 6 pm and we start + + align:start position:0% +get home around 6 pm and we start + + + align:start position:0% +get home around 6 pm and we start +turning on lights turning on cooking + + align:start position:0% +turning on lights turning on cooking + + + align:start position:0% +turning on lights turning on cooking +devices is in our energy go load goes up + + align:start position:0% +devices is in our energy go load goes up + + + align:start position:0% +devices is in our energy go load goes up +quite a high again let me probably run + + align:start position:0% +quite a high again let me probably run + + + align:start position:0% +quite a high again let me probably run +the dishwasher or the uh tumble dryer at + + align:start position:0% +the dishwasher or the uh tumble dryer at + + + align:start position:0% +the dishwasher or the uh tumble dryer at +the end of the day again this is a small + + align:start position:0% +the end of the day again this is a small + + + align:start position:0% +the end of the day again this is a small +box that it goes into the electrical + + align:start position:0% +box that it goes into the electrical + + + align:start position:0% +box that it goes into the electrical +panel gives me a handy dashboard tells + + align:start position:0% +panel gives me a handy dashboard tells + + + align:start position:0% +panel gives me a handy dashboard tells +me how much energy I'm consuming + + align:start position:0% +me how much energy I'm consuming + + + align:start position:0% +me how much energy I'm consuming +relative to my bill much to my + + align:start position:0% +relative to my bill much to my + + + align:start position:0% +relative to my bill much to my +frustration it shows I'm totally average + + align:start position:0% +frustration it shows I'm totally average + + + align:start position:0% +frustration it shows I'm totally average +and how much energy I use compared to + + align:start position:0% +and how much energy I use compared to + + + align:start position:0% +and how much energy I use compared to +other similar homes I use less than + + align:start position:0% +other similar homes I use less than + + + align:start position:0% +other similar homes I use less than +other sense homes in Massachusetts I use + + align:start position:0% +other sense homes in Massachusetts I use + + + align:start position:0% +other sense homes in Massachusetts I use +yet less than most sense homes all over + + align:start position:0% +yet less than most sense homes all over + + + align:start position:0% +yet less than most sense homes all over +the country but you know it gives me + + align:start position:0% +the country but you know it gives me + + + align:start position:0% +the country but you know it gives me +some useful ways to manage my energy use + + align:start position:0% +some useful ways to manage my energy use + + + align:start position:0% +some useful ways to manage my energy use +shows me when pumps or heat goes on and + + align:start position:0% +shows me when pumps or heat goes on and + + + align:start position:0% +shows me when pumps or heat goes on and +off in my house + + align:start position:0% +off in my house + + + align:start position:0% +off in my house +and it also shows me when certain + + align:start position:0% +and it also shows me when certain + + + align:start position:0% +and it also shows me when certain +appliances are on or how much they use + + align:start position:0% +appliances are on or how much they use + + + align:start position:0% +appliances are on or how much they use +for example always on represents the + + align:start position:0% +for example always on represents the + + + align:start position:0% +for example always on represents the +vampire load these are all the Chargers + + align:start position:0% +vampire load these are all the Chargers + + + align:start position:0% +vampire load these are all the Chargers +that are plugged into all the walls all + + align:start position:0% +that are plugged into all the walls all + + + align:start position:0% +that are plugged into all the walls all +the time this is a point that Makai + + align:start position:0% +the time this is a point that Makai + + + align:start position:0% +the time this is a point that Makai +makes but also shows me how much each of + + align:start position:0% +makes but also shows me how much each of + + + align:start position:0% +makes but also shows me how much each of +the AC units use it showed me how much + + align:start position:0% +the AC units use it showed me how much + + + align:start position:0% +the AC units use it showed me how much +that implies on a bill basis shows me + + align:start position:0% +that implies on a bill basis shows me + + + align:start position:0% +that implies on a bill basis shows me +which appliances use the most and shows + + align:start position:0% +which appliances use the most and shows + + + align:start position:0% +which appliances use the most and shows +me ways I could possibly reduce my + + align:start position:0% +me ways I could possibly reduce my + + + align:start position:0% +me ways I could possibly reduce my +energy consumption here you can see that + + align:start position:0% +energy consumption here you can see that + + + align:start position:0% +energy consumption here you can see that +my clothes dryer I off to about 41 + + align:start position:0% +my clothes dryer I off to about 41 + + + align:start position:0% +my clothes dryer I off to about 41 +dollars per year six percent of my + + align:start position:0% +dollars per year six percent of my + + + align:start position:0% +dollars per year six percent of my +electricity use you can see how many how + + align:start position:0% +electricity use you can see how many how + + + align:start position:0% +electricity use you can see how many how +many times or how often I put it on + + align:start position:0% +many times or how often I put it on + + + align:start position:0% +many times or how often I put it on +another device that I use to measure uh + + align:start position:0% +another device that I use to measure uh + + + align:start position:0% +another device that I use to measure uh +manage our home electricity use is a + + align:start position:0% +manage our home electricity use is a + + + align:start position:0% +manage our home electricity use is a +nest thermostat you can see right now + + align:start position:0% +nest thermostat you can see right now + + + align:start position:0% +nest thermostat you can see right now +the downstairs is set for 65 degrees + + align:start position:0% +the downstairs is set for 65 degrees + + + align:start position:0% +the downstairs is set for 65 degrees +upstairs for 63 degrees because it's + + align:start position:0% +upstairs for 63 degrees because it's + + + align:start position:0% +upstairs for 63 degrees because it's +been hot upstairs during the day very + + align:start position:0% +been hot upstairs during the day very + + + align:start position:0% +been hot upstairs during the day very +much if I click on one of these you can + + align:start position:0% +much if I click on one of these you can + + + align:start position:0% +much if I click on one of these you can +see that I have a schedule + + align:start position:0% +see that I have a schedule + + + align:start position:0% +see that I have a schedule +that changes throughout the day + + align:start position:0% +that changes throughout the day + + + align:start position:0% +that changes throughout the day +obviously I wanted to heat it while + + align:start position:0% +obviously I wanted to heat it while + + + align:start position:0% +obviously I wanted to heat it while +we're awake and I'd like to have the + + align:start position:0% +we're awake and I'd like to have the + + + align:start position:0% +we're awake and I'd like to have the +house cold while we're asleep but also + + align:start position:0% +house cold while we're asleep but also + + + align:start position:0% +house cold while we're asleep but also +crucially it's useful that you when you + + align:start position:0% +crucially it's useful that you when you + + + align:start position:0% +crucially it's useful that you when you +go let's say to the airport and you're + + align:start position:0% +go let's say to the airport and you're + + + align:start position:0% +go let's say to the airport and you're +on your way to a trip you realize oh I + + align:start position:0% +on your way to a trip you realize oh I + + + align:start position:0% +on your way to a trip you realize oh I +left the thermostat on I can actually + + align:start position:0% +left the thermostat on I can actually + + + align:start position:0% +left the thermostat on I can actually +turn the energy down my entire house + + align:start position:0% +turn the energy down my entire house + + + align:start position:0% +turn the energy down my entire house +remotely + + align:start position:0% +remotely + + + align:start position:0% +remotely +finally I have rooftop solar panels you + + align:start position:0% +finally I have rooftop solar panels you + + + align:start position:0% +finally I have rooftop solar panels you +can see here in the middle of the day + + align:start position:0% +can see here in the middle of the day + + + align:start position:0% +can see here in the middle of the day +one set of panels that are facing the + + align:start position:0% +one set of panels that are facing the + + + align:start position:0% +one set of panels that are facing the +East are still getting a lot of power + + align:start position:0% +East are still getting a lot of power + + + align:start position:0% +East are still getting a lot of power +but slowly the uh as the sun moves over + + align:start position:0% +but slowly the uh as the sun moves over + + + align:start position:0% +but slowly the uh as the sun moves over +the top of the house or the roof line of + + align:start position:0% +the top of the house or the roof line of + + + align:start position:0% +the top of the house or the roof line of +the house all these panels here on the + + align:start position:0% +the house all these panels here on the + + + align:start position:0% +the house all these panels here on the +right are going to get more energy and + + align:start position:0% +right are going to get more energy and + + + align:start position:0% +right are going to get more energy and +it's kind of cool you can actually see + + align:start position:0% +it's kind of cool you can actually see + + + align:start position:0% +it's kind of cool you can actually see +on a weekly basis how much energy uh the + + align:start position:0% +on a weekly basis how much energy uh the + + + align:start position:0% +on a weekly basis how much energy uh the +how much energy is being used + + align:start position:0% +how much energy is being used + + + align:start position:0% +how much energy is being used +and you can actually see + + align:start position:0% +and you can actually see + + + align:start position:0% +and you can actually see +uh throughout the week I got a nice + + align:start position:0% +uh throughout the week I got a nice + + + align:start position:0% +uh throughout the week I got a nice +sunny day with lots of solar energy + + align:start position:0% +sunny day with lots of solar energy + + + align:start position:0% +sunny day with lots of solar energy +maybe a cloudier day with less solar + + align:start position:0% +maybe a cloudier day with less solar + + + align:start position:0% +maybe a cloudier day with less solar +energy and more Soul energy throughout + + align:start position:0% +energy and more Soul energy throughout + + + align:start position:0% +energy and more Soul energy throughout +the day last few days of the week uh + + align:start position:0% +the day last few days of the week uh + + + align:start position:0% +the day last few days of the week uh +there are fancier setups for people a + + align:start position:0% +there are fancier setups for people a + + + align:start position:0% +there are fancier setups for people a +lot of Engineers uh electrical energy + + align:start position:0% +lot of Engineers uh electrical energy + + + align:start position:0% +lot of Engineers uh electrical energy +and Engineers like to calculate how much + + align:start position:0% +and Engineers like to calculate how much + + + align:start position:0% +and Engineers like to calculate how much +solar is coming to the house and how + + align:start position:0% +solar is coming to the house and how + + + align:start position:0% +solar is coming to the house and how +much they're using I clearly don't have + + align:start position:0% +much they're using I clearly don't have + + + align:start position:0% +much they're using I clearly don't have +all these systems integrated but this is + + align:start position:0% +all these systems integrated but this is + + + align:start position:0% +all these systems integrated but this is +to point out that all the data we need + + align:start position:0% +to point out that all the data we need + + + align:start position:0% +to point out that all the data we need +to manage our Energy Efficiency uses are + + align:start position:0% +to manage our Energy Efficiency uses are + + + align:start position:0% +to manage our Energy Efficiency uses are +much is much easier to get it involves + + align:start position:0% +much is much easier to get it involves + + + align:start position:0% +much is much easier to get it involves +installing one device on my electrical + + align:start position:0% +installing one device on my electrical + + + align:start position:0% +installing one device on my electrical +panel it involves managing my + + align:start position:0% +panel it involves managing my + + + align:start position:0% +panel it involves managing my +thermostats communicating through the + + align:start position:0% +thermostats communicating through the + + + align:start position:0% +thermostats communicating through the +Wi-Fi this is my solar panels + + align:start position:0% +Wi-Fi this is my solar panels + + + align:start position:0% +Wi-Fi this is my solar panels +communicating to the internet and + + align:start position:0% +communicating to the internet and + + + align:start position:0% +communicating to the internet and +sending information to my computer or + + align:start position:0% +sending information to my computer or + + + align:start position:0% +sending information to my computer or +web app + + align:start position:0% +web app + + + align:start position:0% +web app +okay and the last point I want to point + + align:start position:0% +okay and the last point I want to point + + + align:start position:0% +okay and the last point I want to point +out the last point I want to make is + + align:start position:0% +out the last point I want to make is + + + align:start position:0% +out the last point I want to make is +that you know a lot of this information + + align:start position:0% +that you know a lot of this information + + + align:start position:0% +that you know a lot of this information +that you need to measure your energy use + + align:start position:0% +that you need to measure your energy use + + + align:start position:0% +that you need to measure your energy use +is actually on your electricity or + + align:start position:0% +is actually on your electricity or + + + align:start position:0% +is actually on your electricity or +natural gas bills I know we talked in + + align:start position:0% +natural gas bills I know we talked in + + + align:start position:0% +natural gas bills I know we talked in +class about only a third of you get your + + align:start position:0% +class about only a third of you get your + + + align:start position:0% +class about only a third of you get your +bills because the two-thirds of you live + + align:start position:0% +bills because the two-thirds of you live + + + align:start position:0% +bills because the two-thirds of you live +in dorms or let's say share departments + + align:start position:0% +in dorms or let's say share departments + + + align:start position:0% +in dorms or let's say share departments +but if you look at your electricity bill + + align:start position:0% +but if you look at your electricity bill + + + align:start position:0% +but if you look at your electricity bill +for those who get them very carefully + + align:start position:0% +for those who get them very carefully + + + align:start position:0% +for those who get them very carefully +you can see a number of policy + + align:start position:0% +you can see a number of policy + + + align:start position:0% +you can see a number of policy +implications on your bill there's + + align:start position:0% +implications on your bill there's + + + align:start position:0% +implications on your bill there's +various charges for Energy Efficiency + + align:start position:0% +various charges for Energy Efficiency + + + align:start position:0% +various charges for Energy Efficiency +whether or not you access Energy + + align:start position:0% +whether or not you access Energy + + + align:start position:0% +whether or not you access Energy +Efficiency Services there's a delivery + + align:start position:0% +Efficiency Services there's a delivery + + + align:start position:0% +Efficiency Services there's a delivery +charge there's a fuel charge we know all + + align:start position:0% +charge there's a fuel charge we know all + + + align:start position:0% +charge there's a fuel charge we know all +these different charges are changing + + align:start position:0% +these different charges are changing + + + align:start position:0% +these different charges are changing +over time because of our change in + + align:start position:0% +over time because of our change in + + + align:start position:0% +over time because of our change in +energy markets and so I was going I'll + + align:start position:0% +energy markets and so I was going I'll + + + align:start position:0% +energy markets and so I was going I'll +probably show you some bills in class if + + align:start position:0% +probably show you some bills in class if + + + align:start position:0% +probably show you some bills in class if +only because there's privacy + + align:start position:0% +only because there's privacy + + + align:start position:0% +only because there's privacy +implications I don't want to show them + + align:start position:0% +implications I don't want to show them + + + align:start position:0% +implications I don't want to show them +on this video + + align:start position:0% +on this video + + + align:start position:0% +on this video +but let's just think about why buildings + + align:start position:0% +but let's just think about why buildings + + + align:start position:0% +but let's just think about why buildings +again are important in a global sense + + align:start position:0% +again are important in a global sense + + + align:start position:0% +again are important in a global sense +the International Energy agency I did a + + align:start position:0% +the International Energy agency I did a + + + align:start position:0% +the International Energy agency I did a +report in 2020 called tracking buildings + + align:start position:0% +report in 2020 called tracking buildings + + + align:start position:0% +report in 2020 called tracking buildings +and they point out that building energy + + align:start position:0% +and they point out that building energy + + + align:start position:0% +and they point out that building energy +use is not on track to meet our Paris + + align:start position:0% +use is not on track to meet our Paris + + + align:start position:0% +use is not on track to meet our Paris +climate of given goals so we focus on + + align:start position:0% +climate of given goals so we focus on + + + align:start position:0% +climate of given goals so we focus on +different aspects of their report we can + + align:start position:0% +different aspects of their report we can + + + align:start position:0% +different aspects of their report we can +see that lighting has actually been a + + align:start position:0% +see that lighting has actually been a + + + align:start position:0% +see that lighting has actually been a +relative success story we had other + + align:start position:0% +relative success story we had other + + + align:start position:0% +relative success story we had other +forms of lighting and of fluorescent + + align:start position:0% +forms of lighting and of fluorescent + + + align:start position:0% +forms of lighting and of fluorescent +lighting but light emitting diodes LED + + align:start position:0% +lighting but light emitting diodes LED + + + align:start position:0% +lighting but light emitting diodes LED +bulbs have shot up remarkably almost to + + align:start position:0% +bulbs have shot up remarkably almost to + + + align:start position:0% +bulbs have shot up remarkably almost to +about 50 percent of lighting sales uh 20 + + align:start position:0% +about 50 percent of lighting sales uh 20 + + + align:start position:0% +about 50 percent of lighting sales uh 20 +from 2010 to 2018. they're about 50 of + + align:start position:0% +from 2010 to 2018. they're about 50 of + + + align:start position:0% +from 2010 to 2018. they're about 50 of +lighting sales and they are headed for + + align:start position:0% +lighting sales and they are headed for + + + align:start position:0% +lighting sales and they are headed for +about 80 percent that is on track for us + + align:start position:0% +about 80 percent that is on track for us + + + align:start position:0% +about 80 percent that is on track for us +to meet our sustainable development + + align:start position:0% +to meet our sustainable development + + + align:start position:0% +to meet our sustainable development +scenarios or our Paris climate + + align:start position:0% +scenarios or our Paris climate + + + align:start position:0% +scenarios or our Paris climate +agreements + + align:start position:0% +agreements + + + align:start position:0% +agreements +LEDs are a success story because they're + + align:start position:0% +LEDs are a success story because they're + + + align:start position:0% +LEDs are a success story because they're +essentially developed with Government + + align:start position:0% +essentially developed with Government + + + align:start position:0% +essentially developed with Government +research funding but they required + + align:start position:0% +research funding but they required + + + align:start position:0% +research funding but they required +subsidy at the beginning and then as + + align:start position:0% +subsidy at the beginning and then as + + + align:start position:0% +subsidy at the beginning and then as +they are produced in scale they became + + align:start position:0% +they are produced in scale they became + + + align:start position:0% +they are produced in scale they became +much much cheaper I actually bought LED + + align:start position:0% +much much cheaper I actually bought LED + + + align:start position:0% +much much cheaper I actually bought LED +light bulbs in graduate school for I + + align:start position:0% +light bulbs in graduate school for I + + + align:start position:0% +light bulbs in graduate school for I +think about fifty dollars a ball and now + + align:start position:0% +think about fifty dollars a ball and now + + + align:start position:0% +think about fifty dollars a ball and now +these bulbs have the exact same light + + align:start position:0% +these bulbs have the exact same light + + + align:start position:0% +these bulbs have the exact same light +quality as incandescent bulbs or + + align:start position:0% +quality as incandescent bulbs or + + + align:start position:0% +quality as incandescent bulbs or +fluorescent bulbs but now they cost one + + align:start position:0% +fluorescent bulbs but now they cost one + + + align:start position:0% +fluorescent bulbs but now they cost one +dollar or less so LED bulbs are a Energy + + align:start position:0% +dollar or less so LED bulbs are a Energy + + + align:start position:0% +dollar or less so LED bulbs are a Energy +Efficiency success story + + align:start position:0% +Efficiency success story + + + align:start position:0% +Efficiency success story +if you look at building envelopes all + + align:start position:0% +if you look at building envelopes all + + + align:start position:0% +if you look at building envelopes all +the things that Dave Makai did in his + + align:start position:0% +the things that Dave Makai did in his + + + align:start position:0% +the things that Dave Makai did in his +home to try to reduce conduction + + align:start position:0% +home to try to reduce conduction + + + align:start position:0% +home to try to reduce conduction +ventilation and radiative losses you can + + align:start position:0% +ventilation and radiative losses you can + + + align:start position:0% +ventilation and radiative losses you can +see that the EI iea says we are not on + + align:start position:0% +see that the EI iea says we are not on + + + align:start position:0% +see that the EI iea says we are not on +track almost two-thirds of country lack + + align:start position:0% +track almost two-thirds of country lack + + + align:start position:0% +track almost two-thirds of country lack +any mandatory building energy codes + + align:start position:0% +any mandatory building energy codes + + + align:start position:0% +any mandatory building energy codes +meaning that many buildings are not + + align:start position:0% +meaning that many buildings are not + + + align:start position:0% +meaning that many buildings are not +built with any kind of code or any kind + + align:start position:0% +built with any kind of code or any kind + + + align:start position:0% +built with any kind of code or any kind +of Energy Efficiency at all this is + + align:start position:0% +of Energy Efficiency at all this is + + + align:start position:0% +of Energy Efficiency at all this is +similar to the number of buildings that + + align:start position:0% +similar to the number of buildings that + + + align:start position:0% +similar to the number of buildings that +are built with Architects which is only + + align:start position:0% +are built with Architects which is only + + + align:start position:0% +are built with Architects which is only +a small fraction of buildings built in + + align:start position:0% +a small fraction of buildings built in + + + align:start position:0% +a small fraction of buildings built in +the world we know we have a lot of + + align:start position:0% +the world we know we have a lot of + + + align:start position:0% +the world we know we have a lot of +construction that people do themselves + + align:start position:0% +construction that people do themselves + + + align:start position:0% +construction that people do themselves +either do it yourself or informal + + align:start position:0% +either do it yourself or informal + + + align:start position:0% +either do it yourself or informal +settlements but those places are often + + align:start position:0% +settlements but those places are often + + + align:start position:0% +settlements but those places are often +not governed by energy codes so + + align:start position:0% +not governed by energy codes so + + + align:start position:0% +not governed by energy codes so +therefore they're not energy efficient + + align:start position:0% +therefore they're not energy efficient + + + align:start position:0% +therefore they're not energy efficient +and therefore they're not using energy + + align:start position:0% +and therefore they're not using energy + + + align:start position:0% +and therefore they're not using energy +very efficiently in a way that is going + + align:start position:0% +very efficiently in a way that is going + + + align:start position:0% +very efficiently in a way that is going +to help us reach our Paris climate + + align:start position:0% +to help us reach our Paris climate + + + align:start position:0% +to help us reach our Paris climate +agreement goals + + align:start position:0% +agreement goals + + + align:start position:0% +agreement goals +in terms of heating you can see that we + + align:start position:0% +in terms of heating you can see that we + + + align:start position:0% +in terms of heating you can see that we +have fossil fuel based equipment + + align:start position:0% +have fossil fuel based equipment + + + align:start position:0% +have fossil fuel based equipment +conventional electric equipment heat + + align:start position:0% +conventional electric equipment heat + + + align:start position:0% +conventional electric equipment heat +pumps District heat and other renewable + + align:start position:0% +pumps District heat and other renewable + + + align:start position:0% +pumps District heat and other renewable +sources of energy in order to meet our + + align:start position:0% +sources of energy in order to meet our + + + align:start position:0% +sources of energy in order to meet our +sustainable development scenarios we + + align:start position:0% +sustainable development scenarios we + + + align:start position:0% +sustainable development scenarios we +need heat pumps to expand by a factor of + + align:start position:0% +need heat pumps to expand by a factor of + + + align:start position:0% +need heat pumps to expand by a factor of +probably four or five and we need our + + align:start position:0% +probably four or five and we need our + + + align:start position:0% +probably four or five and we need our +use of fossil fuel based equipment like + + align:start position:0% +use of fossil fuel based equipment like + + + align:start position:0% +use of fossil fuel based equipment like +the natural gas coming into our homes + + align:start position:0% +the natural gas coming into our homes + + + align:start position:0% +the natural gas coming into our homes +and spaces now to decrease we need + + align:start position:0% +and spaces now to decrease we need + + + align:start position:0% +and spaces now to decrease we need +conventional electric equipment to + + align:start position:0% +conventional electric equipment to + + + align:start position:0% +conventional electric equipment to +decrease because it's relatively much + + align:start position:0% +decrease because it's relatively much + + + align:start position:0% +decrease because it's relatively much +less efficient than heat pumps District + + align:start position:0% +less efficient than heat pumps District + + + align:start position:0% +less efficient than heat pumps District +heat is not actually predicted to expand + + align:start position:0% +heat is not actually predicted to expand + + + align:start position:0% +heat is not actually predicted to expand +very much and the use of other + + align:start position:0% +very much and the use of other + + + align:start position:0% +very much and the use of other +Renewables and perhaps hydrogen is + + align:start position:0% +Renewables and perhaps hydrogen is + + + align:start position:0% +Renewables and perhaps hydrogen is +expected to expand but the problem is to + + align:start position:0% +expected to expand but the problem is to + + + align:start position:0% +expected to expand but the problem is to +meet our 2050 goals our 2030 goals sorry + + align:start position:0% +meet our 2050 goals our 2030 goals sorry + + + align:start position:0% +meet our 2050 goals our 2030 goals sorry +we are not on track according to the iea + + align:start position:0% +we are not on track according to the iea + + + align:start position:0% +we are not on track according to the iea +in terms of sheet pumps we need more + + align:start position:0% +in terms of sheet pumps we need more + + + align:start position:0% +in terms of sheet pumps we need more +efforts many households purchase heat + + align:start position:0% +efforts many households purchase heat + + + align:start position:0% +efforts many households purchase heat +pumps in 2019 if anything that's + + align:start position:0% +pumps in 2019 if anything that's + + + align:start position:0% +pumps in 2019 if anything that's +probably expanded rapidly with the + + align:start position:0% +probably expanded rapidly with the + + + align:start position:0% +probably expanded rapidly with the +explosion and natural gas prices because + + align:start position:0% +explosion and natural gas prices because + + + align:start position:0% +explosion and natural gas prices because +the war on Ukraine we know heat pump + + align:start position:0% +the war on Ukraine we know heat pump + + + align:start position:0% +the war on Ukraine we know heat pump +sales are going up very quickly some + + align:start position:0% +sales are going up very quickly some + + + align:start position:0% +sales are going up very quickly some +people have said that one of the biggest + + align:start position:0% +people have said that one of the biggest + + + align:start position:0% +people have said that one of the biggest +things we can do to try to reduce + + align:start position:0% +things we can do to try to reduce + + + align:start position:0% +things we can do to try to reduce +Europe's dependent on dependence on + + align:start position:0% +Europe's dependent on dependence on + + + align:start position:0% +Europe's dependent on dependence on +Russian gas + + align:start position:0% +Russian gas + + + align:start position:0% +Russian gas +is to send the heat pumps we need to + + align:start position:0% +is to send the heat pumps we need to + + + align:start position:0% +is to send the heat pumps we need to +manufacture heat pumps as quickly as + + align:start position:0% +manufacture heat pumps as quickly as + + + align:start position:0% +manufacture heat pumps as quickly as +possible but I can tell you from + + align:start position:0% +possible but I can tell you from + + + align:start position:0% +possible but I can tell you from +personal experience my home uses natural + + align:start position:0% +personal experience my home uses natural + + + align:start position:0% +personal experience my home uses natural +gas it is difficult to retrofit a + + align:start position:0% +gas it is difficult to retrofit a + + + align:start position:0% +gas it is difficult to retrofit a +relatively old home with a heat pump or + + align:start position:0% +relatively old home with a heat pump or + + + align:start position:0% +relatively old home with a heat pump or +rather it is not it's not inherently + + align:start position:0% +rather it is not it's not inherently + + + align:start position:0% +rather it is not it's not inherently +difficult but right now even as somebody + + align:start position:0% +difficult but right now even as somebody + + + align:start position:0% +difficult but right now even as somebody +who's very interested in this problem I + + align:start position:0% +who's very interested in this problem I + + + align:start position:0% +who's very interested in this problem I +have a hard time trying to figure out + + align:start position:0% +have a hard time trying to figure out + + + align:start position:0% +have a hard time trying to figure out +how to retrofit my 1925 home with the + + align:start position:0% +how to retrofit my 1925 home with the + + + align:start position:0% +how to retrofit my 1925 home with the +key pump so this is an area where + + align:start position:0% +key pump so this is an area where + + + align:start position:0% +key pump so this is an area where +contractors Architects Engineers + + align:start position:0% +contractors Architects Engineers + + + align:start position:0% +contractors Architects Engineers +um small businesses have a tremendous + + align:start position:0% +um small businesses have a tremendous + + + align:start position:0% +um small businesses have a tremendous +opportunity to increase the adoption of + + align:start position:0% +opportunity to increase the adoption of + + + align:start position:0% +opportunity to increase the adoption of +heat pumps and this is an area where the + + align:start position:0% +heat pumps and this is an area where the + + + align:start position:0% +heat pumps and this is an area where the +inflation reduction act gives a lot of + + align:start position:0% +inflation reduction act gives a lot of + + + align:start position:0% +inflation reduction act gives a lot of +tax incentives for homeowners to + + align:start position:0% +tax incentives for homeowners to + + + align:start position:0% +tax incentives for homeowners to +increase the use of heat pumps which is + + align:start position:0% +increase the use of heat pumps which is + + + align:start position:0% +increase the use of heat pumps which is +why I included that AC Triple E report + + align:start position:0% +why I included that AC Triple E report + + + align:start position:0% +why I included that AC Triple E report +for you to read + + align:start position:0% +for you to read + + + align:start position:0% +for you to read +if you look at cooling efforts cooling + + align:start position:0% +if you look at cooling efforts cooling + + + align:start position:0% +if you look at cooling efforts cooling +efforts uh cooling is actually a big + + align:start position:0% +efforts uh cooling is actually a big + + + align:start position:0% +efforts uh cooling is actually a big +area of concern because we know that not + + align:start position:0% +area of concern because we know that not + + + align:start position:0% +area of concern because we know that not +only is the world getting hotter but + + align:start position:0% +only is the world getting hotter but + + + align:start position:0% +only is the world getting hotter but +lots of places in the world that are + + align:start position:0% +lots of places in the world that are + + + align:start position:0% +lots of places in the world that are +getting richer like sub-Saharan Africa + + align:start position:0% +getting richer like sub-Saharan Africa + + + align:start position:0% +getting richer like sub-Saharan Africa +or southeast Asia India essentially are + + align:start position:0% +or southeast Asia India essentially are + + + align:start position:0% +or southeast Asia India essentially are +relatively hot and humid climates as + + align:start position:0% +relatively hot and humid climates as + + + align:start position:0% +relatively hot and humid climates as +those places get richer and more + + align:start position:0% +those places get richer and more + + + align:start position:0% +those places get richer and more +urbanized there will be greater demand + + align:start position:0% +urbanized there will be greater demand + + + align:start position:0% +urbanized there will be greater demand +for cooling so the energy demand for + + align:start position:0% +for cooling so the energy demand for + + + align:start position:0% +for cooling so the energy demand for +space cooling is actually going up quite + + align:start position:0% +space cooling is actually going up quite + + + align:start position:0% +space cooling is actually going up quite +a bit + + align:start position:0% +a bit + + + align:start position:0% +a bit +there's a space cooling intensity index + + align:start position:0% +there's a space cooling intensity index + + + align:start position:0% +there's a space cooling intensity index +in the sustainable development scenario + + align:start position:0% +in the sustainable development scenario + + + align:start position:0% +in the sustainable development scenario +and we like our space cooling intensity + + align:start position:0% +and we like our space cooling intensity + + + align:start position:0% +and we like our space cooling intensity +index to go down which is the amount of + + align:start position:0% +index to go down which is the amount of + + + align:start position:0% +index to go down which is the amount of +energy we use for cooling the good news + + align:start position:0% +energy we use for cooling the good news + + + align:start position:0% +energy we use for cooling the good news +is if we're going to install air + + align:start position:0% +is if we're going to install air + + + align:start position:0% +is if we're going to install air +conditioning we can simply install a + + align:start position:0% +conditioning we can simply install a + + + align:start position:0% +conditioning we can simply install a +heat pump and get both Heating and + + align:start position:0% +heat pump and get both Heating and + + + align:start position:0% +heat pump and get both Heating and +Cooling benefits and they're relatively + + align:start position:0% +Cooling benefits and they're relatively + + + align:start position:0% +Cooling benefits and they're relatively +more efficient the problem is in order + + align:start position:0% +more efficient the problem is in order + + + align:start position:0% +more efficient the problem is in order +to increase the use of heat pumps again + + align:start position:0% +to increase the use of heat pumps again + + + align:start position:0% +to increase the use of heat pumps again +for cooling we need to make more policy + + align:start position:0% +for cooling we need to make more policy + + + align:start position:0% +for cooling we need to make more policy +effort or more efforts need to be made + + align:start position:0% +effort or more efforts need to be made + + + align:start position:0% +effort or more efforts need to be made +across industry and government + + align:start position:0% +across industry and government + + + align:start position:0% +across industry and government +if you look at appliances and Equipment + + align:start position:0% +if you look at appliances and Equipment + + + align:start position:0% +if you look at appliances and Equipment +Energy Star Energy guide those yellow + + align:start position:0% +Energy Star Energy guide those yellow + + + align:start position:0% +Energy Star Energy guide those yellow +tags on appliances you might buy in the + + align:start position:0% +tags on appliances you might buy in the + + + align:start position:0% +tags on appliances you might buy in the +store energy equipment has become much + + align:start position:0% +store energy equipment has become much + + + align:start position:0% +store energy equipment has become much +more efficient than before partly + + align:start position:0% +more efficient than before partly + + + align:start position:0% +more efficient than before partly +because of changes in technology and + + align:start position:0% +because of changes in technology and + + + align:start position:0% +because of changes in technology and +partly because Energy Efficiency codes + + align:start position:0% +partly because Energy Efficiency codes + + + align:start position:0% +partly because Energy Efficiency codes +have pushed the technology to become + + align:start position:0% +have pushed the technology to become + + + align:start position:0% +have pushed the technology to become +more efficient but in order for us to + + align:start position:0% +more efficient but in order for us to + + + align:start position:0% +more efficient but in order for us to +reach our sustainable development + + align:start position:0% +reach our sustainable development + + + align:start position:0% +reach our sustainable development +scenario in 2030 we still need to make + + align:start position:0% +scenario in 2030 we still need to make + + + align:start position:0% +scenario in 2030 we still need to make +more effort uh demand is being driven by + + align:start position:0% +more effort uh demand is being driven by + + + align:start position:0% +more effort uh demand is being driven by +Rising ownership of connected plug load + + align:start position:0% +Rising ownership of connected plug load + + + align:start position:0% +Rising ownership of connected plug load +devices those are the devices you plug + + align:start position:0% +devices those are the devices you plug + + + align:start position:0% +devices those are the devices you plug +into the wall especially in developing + + align:start position:0% +into the wall especially in developing + + + align:start position:0% +into the wall especially in developing +countries that are becoming wealthier so + + align:start position:0% +countries that are becoming wealthier so + + + align:start position:0% +countries that are becoming wealthier so +we need to try to pass performance + + align:start position:0% +we need to try to pass performance + + + align:start position:0% +we need to try to pass performance +standards that govern how much energy + + align:start position:0% +standards that govern how much energy + + + align:start position:0% +standards that govern how much energy +all of our devices use + + align:start position:0% +all of our devices use + + + align:start position:0% +all of our devices use +and finally you know there's also + + align:start position:0% +and finally you know there's also + + + align:start position:0% +and finally you know there's also +behavioral interventions we can make + + align:start position:0% +behavioral interventions we can make + + + align:start position:0% +behavioral interventions we can make +this is an important thing I want to + + align:start position:0% +this is an important thing I want to + + + align:start position:0% +this is an important thing I want to +touch on today leading into next week's + + align:start position:0% +touch on today leading into next week's + + + align:start position:0% +touch on today leading into next week's +discussion this is a paper by Tyler + + align:start position:0% +discussion this is a paper by Tyler + + + align:start position:0% +discussion this is a paper by Tyler +margettis shazina Atari and David Landy + + align:start position:0% +margettis shazina Atari and David Landy + + + align:start position:0% +margettis shazina Atari and David Landy +that is published in nature in 2019 our + + align:start position:0% +that is published in nature in 2019 our + + + align:start position:0% +that is published in nature in 2019 our +nature energy in 2019 and the headline + + align:start position:0% +nature energy in 2019 and the headline + + + align:start position:0% +nature energy in 2019 and the headline +is simply that simple interventions can + + align:start position:0% +is simply that simple interventions can + + + align:start position:0% +is simply that simple interventions can +correct misperceptions of Home energy + + align:start position:0% +correct misperceptions of Home energy + + + align:start position:0% +correct misperceptions of Home energy +use and the reason why I had you look + + align:start position:0% +use and the reason why I had you look + + + align:start position:0% +use and the reason why I had you look +around your apartments and homes and how + + align:start position:0% +around your apartments and homes and how + + + align:start position:0% +around your apartments and homes and how +much energy things use and try to + + align:start position:0% +much energy things use and try to + + + align:start position:0% +much energy things use and try to +calculate it and really want to look + + align:start position:0% +calculate it and really want to look + + + align:start position:0% +calculate it and really want to look +through Dave MacKay's home is that + + align:start position:0% +through Dave MacKay's home is that + + + align:start position:0% +through Dave MacKay's home is that +people don't have a very good sense + + align:start position:0% +people don't have a very good sense + + + align:start position:0% +people don't have a very good sense +actually how much various appliances use + + align:start position:0% +actually how much various appliances use + + + align:start position:0% +actually how much various appliances use +and if you look at this graph this is + + align:start position:0% +and if you look at this graph this is + + + align:start position:0% +and if you look at this graph this is +the estimate that people give on a + + align:start position:0% +the estimate that people give on a + + + align:start position:0% +the estimate that people give on a +survey a logarithmic scale on the + + align:start position:0% +survey a logarithmic scale on the + + + align:start position:0% +survey a logarithmic scale on the +vertical axis and the actual energy use + + align:start position:0% +vertical axis and the actual energy use + + + align:start position:0% +vertical axis and the actual energy use +of these appliances on the horizontal + + align:start position:0% +of these appliances on the horizontal + + + align:start position:0% +of these appliances on the horizontal +scale also a logarithmic scale which + + align:start position:0% +scale also a logarithmic scale which + + + align:start position:0% +scale also a logarithmic scale which +means that people perfectly predicted + + align:start position:0% +means that people perfectly predicted + + + align:start position:0% +means that people perfectly predicted +the amount of energy use all these + + align:start position:0% +the amount of energy use all these + + + align:start position:0% +the amount of energy use all these +different devices use they'd be right on + + align:start position:0% +different devices use they'd be right on + + + align:start position:0% +different devices use they'd be right on +this dotted line + + align:start position:0% +this dotted line + + + align:start position:0% +this dotted line +but you can see for small devices like + + align:start position:0% +but you can see for small devices like + + + align:start position:0% +but you can see for small devices like +LEDs they actually estimate they use + + align:start position:0% +LEDs they actually estimate they use + + + align:start position:0% +LEDs they actually estimate they use +more than they actually do and for large + + align:start position:0% +more than they actually do and for large + + + align:start position:0% +more than they actually do and for large +devices like a central air conditioner + + align:start position:0% +devices like a central air conditioner + + + align:start position:0% +devices like a central air conditioner +they actually estimate it using less + + align:start position:0% +they actually estimate it using less + + + align:start position:0% +they actually estimate it using less +energy than they actually do or else + + align:start position:0% +energy than they actually do or else + + + align:start position:0% +energy than they actually do or else +they would be on this dotted line + + align:start position:0% +they would be on this dotted line + + + align:start position:0% +they would be on this dotted line +and so the key Point here is that they + + align:start position:0% +and so the key Point here is that they + + + align:start position:0% +and so the key Point here is that they +actually do an experiment where they + + align:start position:0% +actually do an experiment where they + + + align:start position:0% +actually do an experiment where they +target the use of energy use and they + + align:start position:0% +target the use of energy use and they + + + align:start position:0% +target the use of energy use and they +try to develop two interventions first + + align:start position:0% +try to develop two interventions first + + + align:start position:0% +try to develop two interventions first +they try to Target how people respond by + + align:start position:0% +they try to Target how people respond by + + + align:start position:0% +they try to Target how people respond by +just giving people quantitative + + align:start position:0% +just giving people quantitative + + + align:start position:0% +just giving people quantitative +information about the extreme + + align:start position:0% +information about the extreme + + + align:start position:0% +information about the extreme +electricity is they tell they tell + + align:start position:0% +electricity is they tell they tell + + + align:start position:0% +electricity is they tell they tell +people how much a phone charger uses how + + align:start position:0% +people how much a phone charger uses how + + + align:start position:0% +people how much a phone charger uses how +much a clothes dryer use uses and they + + align:start position:0% +much a clothes dryer use uses and they + + + align:start position:0% +much a clothes dryer use uses and they +predict that this is going to help + + align:start position:0% +predict that this is going to help + + + align:start position:0% +predict that this is going to help +people understand or translate their + + align:start position:0% +people understand or translate their + + + align:start position:0% +people understand or translate their +beliefs into energy use into explicit + + align:start position:0% +beliefs into energy use into explicit + + + align:start position:0% +beliefs into energy use into explicit +aspects without necessarily changing + + align:start position:0% +aspects without necessarily changing + + + align:start position:0% +aspects without necessarily changing +their underlying beliefs about energy + + align:start position:0% +their underlying beliefs about energy + + + align:start position:0% +their underlying beliefs about energy +use and that's relevant because we know + + align:start position:0% +use and that's relevant because we know + + + align:start position:0% +use and that's relevant because we know +we have very different beliefs about + + align:start position:0% +we have very different beliefs about + + + align:start position:0% +we have very different beliefs about +energy use and climate + + align:start position:0% +energy use and climate + + + align:start position:0% +energy use and climate +the second thing they do is they target + + align:start position:0% +the second thing they do is they target + + + align:start position:0% +the second thing they do is they target +systematic understanding by supplying a + + align:start position:0% +systematic understanding by supplying a + + + align:start position:0% +systematic understanding by supplying a +simple explicit heuristic rule they say + + align:start position:0% +simple explicit heuristic rule they say + + + align:start position:0% +simple explicit heuristic rule they say +people underestimate the energy by + + align:start position:0% +people underestimate the energy by + + + align:start position:0% +people underestimate the energy by +appliances that change the temperature + + align:start position:0% +appliances that change the temperature + + + align:start position:0% +appliances that change the temperature +perhaps because heat generation and heat + + align:start position:0% +perhaps because heat generation and heat + + + align:start position:0% +perhaps because heat generation and heat +removal may not be as noticeable as + + align:start position:0% +removal may not be as noticeable as + + + align:start position:0% +removal may not be as noticeable as +movement or lighting so therefore they + + align:start position:0% +movement or lighting so therefore they + + + align:start position:0% +movement or lighting so therefore they +give this explicit heuristic this kind + + align:start position:0% +give this explicit heuristic this kind + + + align:start position:0% +give this explicit heuristic this kind +of rule for people to judge energies + + align:start position:0% +of rule for people to judge energies + + + align:start position:0% +of rule for people to judge energies +they say larger appliances that + + align:start position:0% +they say larger appliances that + + + align:start position:0% +they say larger appliances that +primarily heat or cool use a lot more + + align:start position:0% +primarily heat or cool use a lot more + + + align:start position:0% +primarily heat or cool use a lot more +energy than people think they use that's + + align:start position:0% +energy than people think they use that's + + + align:start position:0% +energy than people think they use that's +all they say and they give people these + + align:start position:0% +all they say and they give people these + + + align:start position:0% +all they say and they give people these +two interventions and see how well they + + align:start position:0% +two interventions and see how well they + + + align:start position:0% +two interventions and see how well they +can estimate energy use + + align:start position:0% +can estimate energy use + + + align:start position:0% +can estimate energy use +the reason why that's important is + + align:start position:0% +the reason why that's important is + + + align:start position:0% +the reason why that's important is +because our underlying beliefs about + + align:start position:0% +because our underlying beliefs about + + + align:start position:0% +because our underlying beliefs about +energy and climate may actually shape + + align:start position:0% +energy and climate may actually shape + + + align:start position:0% +energy and climate may actually shape +how well we can actually perceive energy + + align:start position:0% +how well we can actually perceive energy + + + align:start position:0% +how well we can actually perceive energy +use these are all graphs that show the + + align:start position:0% +use these are all graphs that show the + + + align:start position:0% +use these are all graphs that show the +understanding of finds a relatively + + align:start position:0% +understanding of finds a relatively + + + align:start position:0% +understanding of finds a relatively +relative energy use on the horizontal + + align:start position:0% +relative energy use on the horizontal + + + align:start position:0% +relative energy use on the horizontal +axis and to see how they're correlated + + align:start position:0% +axis and to see how they're correlated + + + align:start position:0% +axis and to see how they're correlated +with behavioral Choice accuracy which uh + + align:start position:0% +with behavioral Choice accuracy which uh + + + align:start position:0% +with behavioral Choice accuracy which uh +behavioral choices people use make to + + align:start position:0% +behavioral choices people use make to + + + align:start position:0% +behavioral choices people use make to +change their energy use they see if it + + align:start position:0% +change their energy use they see if it + + + align:start position:0% +change their energy use they see if it +correlates with pro-environmental + + align:start position:0% +correlates with pro-environmental + + + align:start position:0% +correlates with pro-environmental +attitudes they see if it correlates with + + align:start position:0% +attitudes they see if it correlates with + + + align:start position:0% +attitudes they see if it correlates with +climate change beliefs and to see if it + + align:start position:0% +climate change beliefs and to see if it + + + align:start position:0% +climate change beliefs and to see if it +correlates with climate policy support + + align:start position:0% +correlates with climate policy support + + + align:start position:0% +correlates with climate policy support +and you can see that behavioral Choice + + align:start position:0% +and you can see that behavioral Choice + + + align:start position:0% +and you can see that behavioral Choice +accuracy is actually relatively the same + + align:start position:0% +accuracy is actually relatively the same + + + align:start position:0% +accuracy is actually relatively the same +among liberates liberals moderates and + + align:start position:0% +among liberates liberals moderates and + + + align:start position:0% +among liberates liberals moderates and +conservatives but you can see that Pro + + align:start position:0% +conservatives but you can see that Pro + + + align:start position:0% +conservatives but you can see that Pro +enviral attitudes climate change beliefs + + align:start position:0% +enviral attitudes climate change beliefs + + + align:start position:0% +enviral attitudes climate change beliefs +and climate policy support all diverge + + align:start position:0% +and climate policy support all diverge + + + align:start position:0% +and climate policy support all diverge +that's their point of this paper is that + + align:start position:0% +that's their point of this paper is that + + + align:start position:0% +that's their point of this paper is that +if you actually Supply people with both + + align:start position:0% +if you actually Supply people with both + + + align:start position:0% +if you actually Supply people with both +this kind of scale use intervention + + align:start position:0% +this kind of scale use intervention + + + align:start position:0% +this kind of scale use intervention +telling people how much energy + + align:start position:0% +telling people how much energy + + + align:start position:0% +telling people how much energy +appliances use or giving them an + + align:start position:0% +appliances use or giving them an + + + align:start position:0% +appliances use or giving them an +increased understanding of appliances + + align:start position:0% +increased understanding of appliances + + + align:start position:0% +increased understanding of appliances +relative energy use they have different + + align:start position:0% +relative energy use they have different + + + align:start position:0% +relative energy use they have different +implications for who may be listening to + + align:start position:0% +implications for who may be listening to + + + align:start position:0% +implications for who may be listening to +this message and how they might act on + + align:start position:0% +this message and how they might act on + + + align:start position:0% +this message and how they might act on +these beliefs so they argue in this + + align:start position:0% +these beliefs so they argue in this + + + align:start position:0% +these beliefs so they argue in this +paper that if you increase people's + + align:start position:0% +paper that if you increase people's + + + align:start position:0% +paper that if you increase people's +understanding of Appliance development + + align:start position:0% +understanding of Appliance development + + + align:start position:0% +understanding of Appliance development +energy use you may be able to not + + align:start position:0% +energy use you may be able to not + + + align:start position:0% +energy use you may be able to not +necessarily affect their programmable + + align:start position:0% +necessarily affect their programmable + + + align:start position:0% +necessarily affect their programmable +attitudes or the climate change beliefs + + align:start position:0% +attitudes or the climate change beliefs + + + align:start position:0% +attitudes or the climate change beliefs +or their support for climate policies + + align:start position:0% +or their support for climate policies + + + align:start position:0% +or their support for climate policies +but at least you can correct the + + align:start position:0% +but at least you can correct the + + + align:start position:0% +but at least you can correct the +misperceptions of Home energy use + + align:start position:0% +misperceptions of Home energy use + + + align:start position:0% +misperceptions of Home energy use +finally just to kind of touch on the + + align:start position:0% +finally just to kind of touch on the + + + align:start position:0% +finally just to kind of touch on the +help aspect of decarbonization this is a + + align:start position:0% +help aspect of decarbonization this is a + + + align:start position:0% +help aspect of decarbonization this is a +project I'm working on in indoor air + + align:start position:0% +project I'm working on in indoor air + + + align:start position:0% +project I'm working on in indoor air +quality in New York City it's an + + align:start position:0% +quality in New York City it's an + + + align:start position:0% +quality in New York City it's an +interesting project because we're + + align:start position:0% +interesting project because we're + + + align:start position:0% +interesting project because we're +working on a low-income or affordable + + align:start position:0% +working on a low-income or affordable + + + align:start position:0% +working on a low-income or affordable +housing building a subsidized housing + + align:start position:0% +housing building a subsidized housing + + + align:start position:0% +housing building a subsidized housing +building and what the developer or the + + align:start position:0% +building and what the developer or the + + + align:start position:0% +building and what the developer or the +owner is doing is essentially + + align:start position:0% +owner is doing is essentially + + + align:start position:0% +owner is doing is essentially +retrofitting this building to be + + align:start position:0% +retrofitting this building to be + + + align:start position:0% +retrofitting this building to be +decarborized they're upgrading it to + + align:start position:0% +decarborized they're upgrading it to + + + align:start position:0% +decarborized they're upgrading it to +passive house standards meaning they're + + align:start position:0% +passive house standards meaning they're + + + align:start position:0% +passive house standards meaning they're +wrapping the whole building in a highly + + align:start position:0% +wrapping the whole building in a highly + + + align:start position:0% +wrapping the whole building in a highly +efficient envelope and they're + + align:start position:0% +efficient envelope and they're + + + align:start position:0% +efficient envelope and they're +decarbonizing building the building by + + align:start position:0% +decarbonizing building the building by + + + align:start position:0% +decarbonizing building the building by +taking the water heating and the space + + align:start position:0% +taking the water heating and the space + + + align:start position:0% +taking the water heating and the space +heating out and installing basically + + align:start position:0% +heating out and installing basically + + + align:start position:0% +heating out and installing basically +heat pumps of the roof that will push + + align:start position:0% +heat pumps of the roof that will push + + + align:start position:0% +heat pumps of the roof that will push +air down to each of the apartment lines + + align:start position:0% +air down to each of the apartment lines + + + align:start position:0% +air down to each of the apartment lines +through these blue ventilation shops and + + align:start position:0% +through these blue ventilation shops and + + + align:start position:0% +through these blue ventilation shops and +of course when the ventilation or the uh + + align:start position:0% +of course when the ventilation or the uh + + + align:start position:0% +of course when the ventilation or the uh +exhaust air comes out of the apartments + + align:start position:0% +exhaust air comes out of the apartments + + + align:start position:0% +exhaust air comes out of the apartments +it'll come up back to this blue line and + + align:start position:0% +it'll come up back to this blue line and + + + align:start position:0% +it'll come up back to this blue line and +go through the heat exchanger meaning + + align:start position:0% +go through the heat exchanger meaning + + + align:start position:0% +go through the heat exchanger meaning +that all the heat will be captured in + + align:start position:0% +that all the heat will be captured in + + + align:start position:0% +that all the heat will be captured in +the building even if we need to push in + + align:start position:0% +the building even if we need to push in + + + align:start position:0% +the building even if we need to push in +new fresh air for ventilation + + align:start position:0% +new fresh air for ventilation + + + align:start position:0% +new fresh air for ventilation +but we also have to think of the + + align:start position:0% +but we also have to think of the + + + align:start position:0% +but we also have to think of the +implications this has for ventilation + + align:start position:0% +implications this has for ventilation + + + align:start position:0% +implications this has for ventilation +and for health we know that + + align:start position:0% +and for health we know that + + + align:start position:0% +and for health we know that +um + + align:start position:0% +um + + + align:start position:0% +um +Gas Appliances produce uh uncombusted + + align:start position:0% +Gas Appliances produce uh uncombusted + + + align:start position:0% +Gas Appliances produce uh uncombusted +methane but also particulate matter and + + align:start position:0% +methane but also particulate matter and + + + align:start position:0% +methane but also particulate matter and +have a gas or chemical it may release + + align:start position:0% +have a gas or chemical it may release + + + align:start position:0% +have a gas or chemical it may release +chemicals into living spaces so what + + align:start position:0% +chemicals into living spaces so what + + + align:start position:0% +chemicals into living spaces so what +we're hoping to see in this project is + + align:start position:0% +we're hoping to see in this project is + + + align:start position:0% +we're hoping to see in this project is +by decarbonizing and removing the gas in + + align:start position:0% +by decarbonizing and removing the gas in + + + align:start position:0% +by decarbonizing and removing the gas in +the building we improve air quality + + align:start position:0% +the building we improve air quality + + + align:start position:0% +the building we improve air quality +inside this building and so we put these + + align:start position:0% +inside this building and so we put these + + + align:start position:0% +inside this building and so we put these +air quality sensors and all these points + + align:start position:0% +air quality sensors and all these points + + + align:start position:0% +air quality sensors and all these points +in the building what we are hoping to + + align:start position:0% +in the building what we are hoping to + + + align:start position:0% +in the building what we are hoping to +show + + align:start position:0% +show + + + align:start position:0% +show +is that not only can we decarbonize a + + align:start position:0% +is that not only can we decarbonize a + + + align:start position:0% +is that not only can we decarbonize a +relatively inexpensive or low income + + align:start position:0% +relatively inexpensive or low income + + + align:start position:0% +relatively inexpensive or low income +building if we can decarbonize it we + + align:start position:0% +building if we can decarbonize it we + + + align:start position:0% +building if we can decarbonize it we +also improve people's air quality inside + + align:start position:0% +also improve people's air quality inside + + + align:start position:0% +also improve people's air quality inside +their homes so we're hoping for a triple + + align:start position:0% +their homes so we're hoping for a triple + + + align:start position:0% +their homes so we're hoping for a triple +win and that is applicable to any + + align:start position:0% +win and that is applicable to any + + + align:start position:0% +win and that is applicable to any +building it is relatively cheap that it + + align:start position:0% +building it is relatively cheap that it + + + align:start position:0% +building it is relatively cheap that it +eliminates the greenhouse gas use in + + align:start position:0% +eliminates the greenhouse gas use in + + + align:start position:0% +eliminates the greenhouse gas use in +these buildings and also improves + + align:start position:0% +these buildings and also improves + + + align:start position:0% +these buildings and also improves +People's Health we've been doing a + + align:start position:0% +People's Health we've been doing a + + + align:start position:0% +People's Health we've been doing a +two-year field experiment and we're + + align:start position:0% +two-year field experiment and we're + + + align:start position:0% +two-year field experiment and we're +almost done with it so I'm looking + + align:start position:0% +almost done with it so I'm looking + + + align:start position:0% +almost done with it so I'm looking +forward to sharing the results with you + + align:start position:0% +forward to sharing the results with you + + + align:start position:0% +forward to sharing the results with you +and soon and that concludes our lecture + + align:start position:0% +and soon and that concludes our lecture + + + align:start position:0% +and soon and that concludes our lecture +for today \ No newline at end of file diff --git a/F07k0PSQ8xk.txt b/F07k0PSQ8xk.txt new file mode 100644 index 0000000000000000000000000000000000000000..655b8c590d37a38cbea07ac76fa21e9d0b808be3 --- /dev/null +++ b/F07k0PSQ8xk.txt @@ -0,0 +1,2927 @@ +align:start position:0% + +this week but it's still let's see + + align:start position:0% + + + + align:start position:0% + +because it doesn't + + align:start position:0% + + + + align:start position:0% + +literally it means how does it go + + align:start position:0% +literally it means how does it go + + + align:start position:0% +literally it means how does it go +so it's it's general + + align:start position:0% +so it's it's general + + + align:start position:0% +so it's it's general +it doesn't matter if i'm talking to one + + align:start position:0% +it doesn't matter if i'm talking to one + + + align:start position:0% +it doesn't matter if i'm talking to one +person or + + align:start position:0% +person or + + + align:start position:0% +person or +more people at a time coming up + + align:start position:0% +more people at a time coming up + + + align:start position:0% +more people at a time coming up +try to say it + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% + + + + align:start position:0% + +what is it + + align:start position:0% +what is it + + + align:start position:0% +what is it +the festival + + align:start position:0% + + + + align:start position:0% + +yeah it could be it could be a party + + align:start position:0% +yeah it could be it could be a party + + + align:start position:0% +yeah it could be it could be a party +but in this case it's a celebration or a + + align:start position:0% +but in this case it's a celebration or a + + + align:start position:0% +but in this case it's a celebration or a +holiday + + align:start position:0% + + + + align:start position:0% + +women international women's day oh yeah + + align:start position:0% +women international women's day oh yeah + + + align:start position:0% +women international women's day oh yeah +it's wednesday + + align:start position:0% + + + + align:start position:0% + +once + + align:start position:0% + + + + align:start position:0% + +so it's celebrated well everywhere + + align:start position:0% +so it's celebrated well everywhere + + + align:start position:0% +so it's celebrated well everywhere +around the world it's the international + + align:start position:0% +around the world it's the international + + + align:start position:0% +around the world it's the international +international women's day + + align:start position:0% +international women's day + + + align:start position:0% +international women's day +and it's a day when we honor women and + + align:start position:0% +and it's a day when we honor women and + + + align:start position:0% +and it's a day when we honor women and +well we try to remind ourselves that we + + align:start position:0% +well we try to remind ourselves that we + + + align:start position:0% +well we try to remind ourselves that we +need to make a constant action + + align:start position:0% +need to make a constant action + + + align:start position:0% +need to make a constant action +to keep equality + + align:start position:0% +to keep equality + + + align:start position:0% +to keep equality +and + + align:start position:0% +and + + + align:start position:0% +and +to be fair + + align:start position:0% +to be fair + + + align:start position:0% +to be fair +in every aspect of life + + align:start position:0% +in every aspect of life + + + align:start position:0% +in every aspect of life +so i think it's really funny because in + + align:start position:0% +so i think it's really funny because in + + + align:start position:0% +so i think it's really funny because in +the us + + align:start position:0% +the us + + + align:start position:0% +the us +everybody's paying attention to equality + + align:start position:0% +everybody's paying attention to equality + + + align:start position:0% +everybody's paying attention to equality +but + + align:start position:0% +but + + + align:start position:0% +but +there isn't a big celebration for la + + align:start position:0% +there isn't a big celebration for la + + + align:start position:0% +there isn't a big celebration for la +festa de la donna + + align:start position:0% +festa de la donna + + + align:start position:0% +festa de la donna +well in italy it's different since about + + align:start position:0% +well in italy it's different since about + + + align:start position:0% +well in italy it's different since about + + align:start position:0% + + + align:start position:0% +we actually celebrate + + align:start position:0% +we actually celebrate + + + align:start position:0% +we actually celebrate +women's day the conditions of women are + + align:start position:0% +women's day the conditions of women are + + + align:start position:0% +women's day the conditions of women are +worse in italy than here but we still + + align:start position:0% +worse in italy than here but we still + + + align:start position:0% +worse in italy than here but we still +celebrate la festa + + align:start position:0% + + + + align:start position:0% + +today if you were in italy every time + + align:start position:0% +today if you were in italy every time + + + align:start position:0% +today if you were in italy every time +you would meet a woman you would say al + + align:start position:0% +you would meet a woman you would say al + + + align:start position:0% +you would meet a woman you would say al +gory + + align:start position:0% + + + + align:start position:0% + +aubury + + align:start position:0% + + + + align:start position:0% + +literally means wishes but it's like + + align:start position:0% +literally means wishes but it's like + + + align:start position:0% +literally means wishes but it's like +felicitations and you can use it in + + align:start position:0% +felicitations and you can use it in + + + align:start position:0% +felicitations and you can use it in +every context it's not just for + + align:start position:0% +every context it's not just for + + + align:start position:0% +every context it's not just for +women's day it's like it's your birthday + + align:start position:0% +women's day it's like it's your birthday + + + align:start position:0% +women's day it's like it's your birthday +aubury new year's eve + + align:start position:0% +aubury new year's eve + + + align:start position:0% +aubury new year's eve +christmas + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% +great + + + align:start position:0% +great +and then you can say specifically for + + align:start position:0% +and then you can say specifically for + + + align:start position:0% +and then you can say specifically for +this day + + align:start position:0% + + + + align:start position:0% + +fiesta + + align:start position:0% + + + + align:start position:0% + +yeah yes so literally it would mean good + + align:start position:0% +yeah yes so literally it would mean good + + + align:start position:0% +yeah yes so literally it would mean good +celebration of the woman but it means + + align:start position:0% +celebration of the woman but it means + + + align:start position:0% +celebration of the woman but it means +that she would say happy women's day + + align:start position:0% +that she would say happy women's day + + + align:start position:0% +that she would say happy women's day +good so try to say talk together one two + + align:start position:0% +good so try to say talk together one two + + + align:start position:0% +good so try to say talk together one two +three + + align:start position:0% + + + + align:start position:0% + +at school we learned that the origin of + + align:start position:0% +at school we learned that the origin of + + + align:start position:0% +at school we learned that the origin of +this day + + align:start position:0% +this day + + + align:start position:0% +this day +has the root in two events that happened + + align:start position:0% +has the root in two events that happened + + + align:start position:0% +has the root in two events that happened +outside italy on the 8th of march + + align:start position:0% +outside italy on the 8th of march + + + align:start position:0% +outside italy on the 8th of march +one happened on + + align:start position:0% +one happened on + + + align:start position:0% +one happened on +the 8th of march + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +and it was a strike + + align:start position:0% +and it was a strike + + + align:start position:0% +and it was a strike +of government workers in new york + + align:start position:0% +of government workers in new york + + + align:start position:0% +of government workers in new york +in the us + + align:start position:0% +in the us + + + align:start position:0% +in the us +and um well apparently after these + + align:start position:0% +and um well apparently after these + + + align:start position:0% +and um well apparently after these +strikes + + align:start position:0% +strikes + + + align:start position:0% +strikes +well these strikes led to the foundation + + align:start position:0% +well these strikes led to the foundation + + + align:start position:0% +well these strikes led to the foundation +of the women + + align:start position:0% +of the women + + + align:start position:0% +of the women +unions + + align:start position:0% +unions + + + align:start position:0% +unions +now i did a little bit of research + + align:start position:0% +now i did a little bit of research + + + align:start position:0% +now i did a little bit of research +and according to some historians this + + align:start position:0% +and according to some historians this + + + align:start position:0% +and according to some historians this +event never happened + + align:start position:0% +event never happened + + + align:start position:0% +event never happened +so is it true + + align:start position:0% + + + + align:start position:0% + +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +so let's try and do this to read this + + align:start position:0% + + + + align:start position:0% + +this is + + align:start position:0% + + + + align:start position:0% + +and i told you that there was a strike + + align:start position:0% +and i told you that there was a strike + + + align:start position:0% +and i told you that there was a strike +it's a very important word that you need + + align:start position:0% +it's a very important word that you need + + + align:start position:0% +it's a very important word that you need +to learn + + align:start position:0% +to learn + + + align:start position:0% +to learn +strike is chop it off + + align:start position:0% + + + + align:start position:0% + +with one with one piece + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +and you need to know this + + align:start position:0% +and you need to know this + + + align:start position:0% +and you need to know this +word because if you travel to italy i'm + + align:start position:0% +word because if you travel to italy i'm + + + align:start position:0% +word because if you travel to italy i'm +like 99 sure that there would be some + + align:start position:0% +like 99 sure that there would be some + + + align:start position:0% +like 99 sure that there would be some +sort of chaperone + + align:start position:0% + + + + align:start position:0% + +yes yeah or some other sort of chaperone + + align:start position:0% +yes yeah or some other sort of chaperone + + + align:start position:0% +yes yeah or some other sort of chaperone +so it's good if you know this word + + align:start position:0% +so it's good if you know this word + + + align:start position:0% +so it's good if you know this word +so i told you that there were two events + + align:start position:0% +so i told you that there were two events + + + align:start position:0% +so i told you that there were two events +that led to the choice of the + + align:start position:0% +that led to the choice of the + + + align:start position:0% +that led to the choice of the +octod + + align:start position:0% + + + + align:start position:0% + +this is the first event + + align:start position:0% + + + + align:start position:0% + +the second one + + align:start position:0% +the second one + + + align:start position:0% +the second one +it's again it's another chopero + + align:start position:0% +it's again it's another chopero + + + align:start position:0% +it's again it's another chopero +this one + + align:start position:0% +this one + + + align:start position:0% +this one +lotto + + align:start position:0% +lotto + + + align:start position:0% +lotto +marzonia + + align:start position:0% + + + + align:start position:0% + +in russia in saint petersburg + + align:start position:0% +in russia in saint petersburg + + + align:start position:0% +in russia in saint petersburg +so women were + + align:start position:0% +so women were + + + align:start position:0% +so women were +protesting + + align:start position:0% +protesting + + + align:start position:0% +protesting +because well it was a very hard period + + align:start position:0% +because well it was a very hard period + + + align:start position:0% +because well it was a very hard period +there was + + align:start position:0% +there was + + + align:start position:0% +there was +the first world war + + align:start position:0% +the first world war + + + align:start position:0% +the first world war +and then there was also the russian + + align:start position:0% +and then there was also the russian + + + align:start position:0% +and then there was also the russian +revolution going on so there were a lot + + align:start position:0% +revolution going on so there were a lot + + + align:start position:0% +revolution going on so there were a lot +of tests and there was like food so they + + align:start position:0% +of tests and there was like food so they + + + align:start position:0% +of tests and there was like food so they +were making this chopero + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +four + + align:start position:0% +four + + + align:start position:0% +four +bread yes + + align:start position:0% +bread yes + + + align:start position:0% +bread yes +and + + align:start position:0% + + + + align:start position:0% + +peace + + align:start position:0% + + + + align:start position:0% + +so we'll chop + + align:start position:0% + + + + align:start position:0% + +so in italy we celebrate it in many + + align:start position:0% +so in italy we celebrate it in many + + + align:start position:0% +so in italy we celebrate it in many +different ways but there are a lot of + + align:start position:0% +different ways but there are a lot of + + + align:start position:0% +different ways but there are a lot of +meetings + + align:start position:0% +meetings + + + align:start position:0% +meetings +maybe discussions public discussions but + + align:start position:0% +maybe discussions public discussions but + + + align:start position:0% +maybe discussions public discussions but +then it's also nice because there is + + align:start position:0% +then it's also nice because there is + + + align:start position:0% +then it's also nice because there is +traditional gift a very simple gift that + + align:start position:0% +traditional gift a very simple gift that + + + align:start position:0% +traditional gift a very simple gift that +people + + align:start position:0% +people + + + align:start position:0% +people +give to women in their lives and this + + align:start position:0% +give to women in their lives and this + + + align:start position:0% +give to women in their lives and this +gift is a flower + + align:start position:0% +gift is a flower + + + align:start position:0% +gift is a flower +called mimosa it's a yellow flower + + align:start position:0% +called mimosa it's a yellow flower + + + align:start position:0% +called mimosa it's a yellow flower +so it's a reminder that it's women's day + + align:start position:0% +so it's a reminder that it's women's day + + + align:start position:0% +so it's a reminder that it's women's day +and also it's very nice because it means + + align:start position:0% +and also it's very nice because it means + + + align:start position:0% +and also it's very nice because it means +you think oh it's spring summer spring + + align:start position:0% +you think oh it's spring summer spring + + + align:start position:0% +you think oh it's spring summer spring +this is a stand + + align:start position:0% +this is a stand + + + align:start position:0% +this is a stand +that the italian post office made in the + + align:start position:0% +that the italian post office made in the + + + align:start position:0% +that the italian post office made in the +occasion of bethesda de la donna last + + align:start position:0% +occasion of bethesda de la donna last + + + align:start position:0% +occasion of bethesda de la donna last +year + + align:start position:0% +year + + + align:start position:0% +year +and this is the mimosa flower + + align:start position:0% +and this is the mimosa flower + + + align:start position:0% +and this is the mimosa flower +it's nice it's yellow and it has a very + + align:start position:0% +it's nice it's yellow and it has a very + + + align:start position:0% +it's nice it's yellow and it has a very +sweet smell + + align:start position:0% +sweet smell + + + align:start position:0% +sweet smell +it's a a tree + + align:start position:0% +it's a a tree + + + align:start position:0% +it's a a tree +an albero + + align:start position:0% + + + + align:start position:0% + +and this tree is native of australia but + + align:start position:0% +and this tree is native of australia but + + + align:start position:0% +and this tree is native of australia but +we grow it + + align:start position:0% +we grow it + + + align:start position:0% +we grow it +in italy + + align:start position:0% +in italy + + + align:start position:0% +in italy +and particularly the latalot there are a + + align:start position:0% +and particularly the latalot there are a + + + align:start position:0% +and particularly the latalot there are a +lot of mimosa trees + + align:start position:0% +lot of mimosa trees + + + align:start position:0% +lot of mimosa trees +in liguria + + align:start position:0% + + + + align:start position:0% + +do you know where liguria is + + align:start position:0% +do you know where liguria is + + + align:start position:0% +do you know where liguria is +so what i was telling you is that we we + + align:start position:0% +so what i was telling you is that we we + + + align:start position:0% +so what i was telling you is that we we +grow a lot of mimosa + + align:start position:0% +grow a lot of mimosa + + + align:start position:0% +grow a lot of mimosa +by the way in english you would say + + align:start position:0% +by the way in english you would say + + + align:start position:0% +by the way in english you would say +acacia it's a certain location it's a + + align:start position:0% +acacia it's a certain location it's a + + + align:start position:0% +acacia it's a certain location it's a +kind of issue + + align:start position:0% +kind of issue + + + align:start position:0% +kind of issue +okay + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +and the vision i was telling you about + + align:start position:0% +and the vision i was telling you about + + + align:start position:0% +and the vision i was telling you about +is called liguria + + align:start position:0% +is called liguria + + + align:start position:0% +is called liguria +and it's here + + align:start position:0% + + + + align:start position:0% + +so i've been talking a lot now but it's + + align:start position:0% +so i've been talking a lot now but it's + + + align:start position:0% +so i've been talking a lot now but it's +your turn guys + + align:start position:0% +your turn guys + + + align:start position:0% +your turn guys +i'm also a spectator now it's their turn + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +what did you understand what did they + + align:start position:0% +what did you understand what did they + + + align:start position:0% +what did you understand what did they +say there was the one thing you said you + + align:start position:0% +say there was the one thing you said you + + + align:start position:0% +say there was the one thing you said you +liked doing yeah + + align:start position:0% +liked doing yeah + + + align:start position:0% +liked doing yeah +oh i like food + + align:start position:0% + + + + align:start position:0% + +yes and that's food + + align:start position:0% +yes and that's food + + + align:start position:0% +yes and that's food +so they introduced themselves and they + + align:start position:0% +so they introduced themselves and they + + + align:start position:0% +so they introduced themselves and they +were saying where they come from + + align:start position:0% +were saying where they come from + + + align:start position:0% +were saying where they come from +and then they started discussing about + + align:start position:0% +and then they started discussing about + + + align:start position:0% +and then they started discussing about +what they like + + align:start position:0% +what they like + + + align:start position:0% +what they like +you said you like + + align:start position:0% +you said you like + + + align:start position:0% +you said you like +food + + align:start position:0% +food + + + align:start position:0% +food +i don't remember + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +about they saw each other they're like + + align:start position:0% +about they saw each other they're like + + + align:start position:0% +about they saw each other they're like +oh i'm doing well you're doing well yeah + + align:start position:0% +oh i'm doing well you're doing well yeah + + + align:start position:0% +oh i'm doing well you're doing well yeah +what did you do this weekend + + align:start position:0% +what did you do this weekend + + + align:start position:0% +what did you do this weekend +i slept and + + align:start position:0% +i slept and + + + align:start position:0% +i slept and +did you eat + + align:start position:0% +did you eat + + + align:start position:0% +did you eat +no oh you cooked what are you doing this + + align:start position:0% +no oh you cooked what are you doing this + + + align:start position:0% +no oh you cooked what are you doing this +weekend + + align:start position:0% + + + + align:start position:0% + +quick pizza + + align:start position:0% + + + + align:start position:0% + +what else did you say + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +this is great every italian would + + align:start position:0% +this is great every italian would + + + align:start position:0% +this is great every italian would +understand + + align:start position:0% +understand + + + align:start position:0% +understand +but it was a mix of spanish and italian + + align:start position:0% + + + + align:start position:0% + +studios + + align:start position:0% + + + + align:start position:0% + +and everybody would understand + + align:start position:0% + + + + align:start position:0% + +so for like i am sleeping + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +so you use the verb stare + + align:start position:0% +so you use the verb stare + + + align:start position:0% +so you use the verb stare +stop + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% + + + + align:start position:0% + +so today we are going to talk a little + + align:start position:0% +so today we are going to talk a little + + + align:start position:0% +so today we are going to talk a little +bit more than usual + + align:start position:0% +bit more than usual + + + align:start position:0% +bit more than usual +i want you to try to talk about + + align:start position:0% +i want you to try to talk about + + + align:start position:0% +i want you to try to talk about +your typical day + + align:start position:0% +your typical day + + + align:start position:0% +your typical day +la nata typically + + align:start position:0% + + + + align:start position:0% + +yes surprise hoping that you can okay + + align:start position:0% +yes surprise hoping that you can okay + + + align:start position:0% +yes surprise hoping that you can okay +question + + align:start position:0% +question + + + align:start position:0% +question +so why i didn't say il giorno typical + + align:start position:0% +so why i didn't say il giorno typical + + + align:start position:0% +so why i didn't say il giorno typical +well in general typical would be + + align:start position:0% +well in general typical would be + + + align:start position:0% +well in general typical would be +fine as well + + align:start position:0% +fine as well + + + align:start position:0% +fine as well +um + + align:start position:0% +um + + + align:start position:0% +um +we used mostly the word word jornata + + align:start position:0% +we used mostly the word word jornata + + + align:start position:0% +we used mostly the word word jornata +when you want to describe the day + + align:start position:0% +when you want to describe the day + + + align:start position:0% +when you want to describe the day +as something that has a duration + + align:start position:0% +as something that has a duration + + + align:start position:0% +as something that has a duration +while journal is just kind of a date + + align:start position:0% +while journal is just kind of a date + + + align:start position:0% +while journal is just kind of a date +so for example + + align:start position:0% +so for example + + + align:start position:0% +so for example +if i'm + + align:start position:0% +if i'm + + + align:start position:0% +if i'm +meeting you in the morning i can say + + align:start position:0% +meeting you in the morning i can say + + + align:start position:0% +meeting you in the morning i can say +bonjourno + + align:start position:0% +bonjourno + + + align:start position:0% +bonjourno +but then if i want to + + align:start position:0% +but then if i want to + + + align:start position:0% +but then if i want to +wish you have a good day i would say + + align:start position:0% + + + + align:start position:0% + +wants to you don't have to speak italian + + align:start position:0% +wants to you don't have to speak italian + + + align:start position:0% +wants to you don't have to speak italian +you can make a mix of any language + + align:start position:0% +you can make a mix of any language + + + align:start position:0% +you can make a mix of any language +i don't speak chinese + + align:start position:0% + + + + align:start position:0% + +go shower + + align:start position:0% + + + + align:start position:0% + +yes i do a shower + + align:start position:0% +yes i do a shower + + + align:start position:0% +yes i do a shower +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and we use the verb fare + + align:start position:0% +and we use the verb fare + + + align:start position:0% +and we use the verb fare +from which we write factcha we use it in + + align:start position:0% +from which we write factcha we use it in + + + align:start position:0% +from which we write factcha we use it in +a lot of different contexts so it's + + align:start position:0% +a lot of different contexts so it's + + + align:start position:0% +a lot of different contexts so it's +really useful facial adoption + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so is this + + align:start position:0% +so is this + + + align:start position:0% +so is this +feminine masculine singular plural + + align:start position:0% + + + + align:start position:0% + +coffee + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +squad + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +for example + + align:start position:0% + + + + align:start position:0% + +and then another couple of things + + align:start position:0% +and then another couple of things + + + align:start position:0% +and then another couple of things +that you would do in your journal + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +it's a funny word + + align:start position:0% + + + + align:start position:0% + +please + + align:start position:0% + + + + align:start position:0% + +i usually use the + + align:start position:0% +i usually use the + + + align:start position:0% +i usually use the +washing machine + + align:start position:0% +washing machine + + + align:start position:0% +washing machine +and what we say + + align:start position:0% +and what we say + + + align:start position:0% +and what we say +we say + + align:start position:0% + + + + align:start position:0% + +lava + + align:start position:0% + + + + align:start position:0% + +and a lot of times i get confused when i + + align:start position:0% +and a lot of times i get confused when i + + + align:start position:0% +and a lot of times i get confused when i +speak + + align:start position:0% +speak + + + align:start position:0% +speak +english + + align:start position:0% +english + + + align:start position:0% +english +i tend to say i do the laundry no + + align:start position:0% + + + + align:start position:0% + +go + + align:start position:0% + + + + align:start position:0% + +all right how do you decide + + align:start position:0% +all right how do you decide + + + align:start position:0% +all right how do you decide +on the articles because there's there's + + align:start position:0% + + + + align:start position:0% + +e e so there are rules and i wrote them + + align:start position:0% +e e so there are rules and i wrote them + + + align:start position:0% +e e so there are rules and i wrote them +in the blog but + + align:start position:0% +in the blog but + + + align:start position:0% +in the blog but +it takes time to remember the rules so + + align:start position:0% +it takes time to remember the rules so + + + align:start position:0% +it takes time to remember the rules so +the best thing is practice but in this + + align:start position:0% +the best thing is practice but in this + + + align:start position:0% +the best thing is practice but in this +case + + align:start position:0% +case + + + align:start position:0% +case +so + + align:start position:0% +so + + + align:start position:0% +so +singular would be amino plural is amici + + align:start position:0% +singular would be amino plural is amici + + + align:start position:0% +singular would be amino plural is amici +it's masculine and it starts with a + + align:start position:0% +it's masculine and it starts with a + + + align:start position:0% +it's masculine and it starts with a +vowel + + align:start position:0% +vowel + + + align:start position:0% +vowel +so for masculine plural you have two + + align:start position:0% +so for masculine plural you have two + + + align:start position:0% +so for masculine plural you have two +options + + align:start position:0% + + + + align:start position:0% + +since it starts with the vowel + + align:start position:0% + + + + align:start position:0% + +but we've been talking a lot about + + align:start position:0% +but we've been talking a lot about + + + align:start position:0% +but we've been talking a lot about +food + + align:start position:0% +food + + + align:start position:0% +food +and + + align:start position:0% + + + + align:start position:0% + +in italy food plays a very central role + + align:start position:0% +in italy food plays a very central role + + + align:start position:0% +in italy food plays a very central role +so everything + + align:start position:0% +so everything + + + align:start position:0% +so everything +everything revolves around food + + align:start position:0% +everything revolves around food + + + align:start position:0% +everything revolves around food +either manchamo or cucinamo + + align:start position:0% +either manchamo or cucinamo + + + align:start position:0% +either manchamo or cucinamo +or pagliamo di mangiare + + align:start position:0% +or pagliamo di mangiare + + + align:start position:0% +or pagliamo di mangiare +but + + align:start position:0% +but + + + align:start position:0% +but +we talk about food what are the main + + align:start position:0% +we talk about food what are the main + + + align:start position:0% +we talk about food what are the main +meals we already heard one + + align:start position:0% +meals we already heard one + + + align:start position:0% +meals we already heard one +conversation + + align:start position:0% +conversation + + + align:start position:0% +conversation +so what is it + + align:start position:0% +so what is it + + + align:start position:0% +so what is it +breakfast yes then we have infrared + + align:start position:0% + + + + align:start position:0% + +yes it's like a mid-afternoon snack + + align:start position:0% +yes it's like a mid-afternoon snack + + + align:start position:0% +yes it's like a mid-afternoon snack +typically very important + + align:start position:0% +typically very important + + + align:start position:0% +typically very important +usually kids + + align:start position:0% + + + + align:start position:0% + +before dinner and maybe if you're on + + align:start position:0% +before dinner and maybe if you're on + + + align:start position:0% +before dinner and maybe if you're on +vacation you can do it also before lunch + + align:start position:0% +vacation you can do it also before lunch + + + align:start position:0% +vacation you can do it also before lunch +you meet with friends at a bar or at + + align:start position:0% +you meet with friends at a bar or at + + + align:start position:0% +you meet with friends at a bar or at +someone + + align:start position:0% +someone + + + align:start position:0% +someone +house + + align:start position:0% +house + + + align:start position:0% +house +and you drink a glass of wine and you + + align:start position:0% +and you drink a glass of wine and you + + + align:start position:0% +and you drink a glass of wine and you +eat + + align:start position:0% +eat + + + align:start position:0% +eat +chips olives bruschetta + + align:start position:0% +chips olives bruschetta + + + align:start position:0% +chips olives bruschetta +you know some little snacks and this is + + align:start position:0% +you know some little snacks and this is + + + align:start position:0% +you know some little snacks and this is +what we call aperitivo + + align:start position:0% +what we call aperitivo + + + align:start position:0% +what we call aperitivo +and it's really + + align:start position:0% +and it's really + + + align:start position:0% +and it's really +aperitivo + + align:start position:0% +aperitivo + + + align:start position:0% +aperitivo +and it's really fun + + align:start position:0% +and it's really fun + + + align:start position:0% +and it's really fun +it's a fun activity we can't do it here + + align:start position:0% +it's a fun activity we can't do it here + + + align:start position:0% +it's a fun activity we can't do it here +we can do a verity with coke if you're + + align:start position:0% +we can do a verity with coke if you're + + + align:start position:0% +we can do a verity with coke if you're +21. + + align:start position:0% + + + + align:start position:0% + +drink orange juice + + align:start position:0% +drink orange juice + + + align:start position:0% +drink orange juice +but it's a really nice event because you + + align:start position:0% +but it's a really nice event because you + + + align:start position:0% +but it's a really nice event because you +you live you know you finish school or + + align:start position:0% +you live you know you finish school or + + + align:start position:0% +you live you know you finish school or +you finish um + + align:start position:0% + + + + align:start position:0% + +work + + align:start position:0% +work + + + align:start position:0% +work +and you can + + align:start position:0% +and you can + + + align:start position:0% +and you can +uh + + align:start position:0% + + + + align:start position:0% + +and as a student it's particularly fun + + align:start position:0% +and as a student it's particularly fun + + + align:start position:0% +and as a student it's particularly fun +because essentially you pay for a glass + + align:start position:0% +because essentially you pay for a glass + + + align:start position:0% +because essentially you pay for a glass +of wine maybe just a few euros and with + + align:start position:0% +of wine maybe just a few euros and with + + + align:start position:0% +of wine maybe just a few euros and with +this glass of wine typically they will + + align:start position:0% +this glass of wine typically they will + + + align:start position:0% +this glass of wine typically they will +give you all kind of food + + align:start position:0% + + + + align:start position:0% + +sounds perfect yes i like that + + align:start position:0% + + + + align:start position:0% + +and finally + + align:start position:0% + + + + align:start position:0% + +china + + align:start position:0% + + + + align:start position:0% + +so if we take a typical + + align:start position:0% +so if we take a typical + + + align:start position:0% +so if we take a typical +fast + + align:start position:0% + + + + align:start position:0% + +we have typically a lot of different + + align:start position:0% +we have typically a lot of different + + + align:start position:0% +we have typically a lot of different +courses right there i listed them here + + align:start position:0% +courses right there i listed them here + + + align:start position:0% +courses right there i listed them here +first time i went to italy with my + + align:start position:0% +first time i went to italy with my + + + align:start position:0% +first time i went to italy with my +husband we were invited for dinner at + + align:start position:0% +husband we were invited for dinner at + + + align:start position:0% +husband we were invited for dinner at +some friend's house + + align:start position:0% +some friend's house + + + align:start position:0% +some friend's house +and so when we started with lanky pasto + + align:start position:0% + + + + align:start position:0% + +then we had a nice + + align:start position:0% +then we had a nice + + + align:start position:0% +then we had a nice +dish of + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +in large quantities so there was a lot + + align:start position:0% +in large quantities so there was a lot + + + align:start position:0% +in large quantities so there was a lot +of pasta + + align:start position:0% +of pasta + + + align:start position:0% +of pasta +so he ate a lot and mike was the guest + + align:start position:0% +so he ate a lot and mike was the guest + + + align:start position:0% +so he ate a lot and mike was the guest +of honor and everybody was telling him + + align:start position:0% +of honor and everybody was telling him + + + align:start position:0% +of honor and everybody was telling him +to manchester + + align:start position:0% +to manchester + + + align:start position:0% +to manchester +that's one dish of pasta second dish of + + align:start position:0% +that's one dish of pasta second dish of + + + align:start position:0% +that's one dish of pasta second dish of +pasta + + align:start position:0% +pasta + + + align:start position:0% +pasta +we need to finish it vanilla we need to + + align:start position:0% +we need to finish it vanilla we need to + + + align:start position:0% +we need to finish it vanilla we need to +finish it + + align:start position:0% +finish it + + + align:start position:0% +finish it +another pasta and then as soon as he + + align:start position:0% +another pasta and then as soon as he + + + align:start position:0% +another pasta and then as soon as he +finished his last piece of pasta + + align:start position:0% +finished his last piece of pasta + + + align:start position:0% +finished his last piece of pasta +everybody said now we can eat it + + align:start position:0% + + + + align:start position:0% + +second course + + align:start position:0% +second course + + + align:start position:0% +second course +typically is pasta rice or soup + + align:start position:0% +typically is pasta rice or soup + + + align:start position:0% +typically is pasta rice or soup +it's a condom + + align:start position:0% +it's a condom + + + align:start position:0% +it's a condom +it can be + + align:start position:0% +it can be + + + align:start position:0% +it can be +some meat + + align:start position:0% +some meat + + + align:start position:0% +some meat +eggs yes + + align:start position:0% +eggs yes + + + align:start position:0% +eggs yes +distechaste + + align:start position:0% + + + + align:start position:0% + +it's a side dish + + align:start position:0% +it's a side dish + + + align:start position:0% +it's a side dish +vegetables for example cheese and then + + align:start position:0% +vegetables for example cheese and then + + + align:start position:0% +vegetables for example cheese and then +dolce + + align:start position:0% + + + + align:start position:0% + +so in our classes i don't know if you + + align:start position:0% +so in our classes i don't know if you + + + align:start position:0% +so in our classes i don't know if you +noticed but during the first four weeks + + align:start position:0% +noticed but during the first four weeks + + + align:start position:0% +noticed but during the first four weeks +we were just cooking + + align:start position:0% + + + + align:start position:0% + +and then after four weeks + + align:start position:0% +and then after four weeks + + + align:start position:0% +and then after four weeks +and with four weeks + + align:start position:0% + + + + align:start position:0% + +thank you + + align:start position:0% + + + + align:start position:0% + +is every time that you take something + + align:start position:0% +is every time that you take something + + + align:start position:0% +is every time that you take something +you mince it + + align:start position:0% +you mince it + + + align:start position:0% +you mince it +you put it together typically you may + + align:start position:0% +you put it together typically you may + + + align:start position:0% +you put it together typically you may +add some + + align:start position:0% +add some + + + align:start position:0% +add some +some + + align:start position:0% +some + + + align:start position:0% +some +bread crumbs maybe one egg so everything + + align:start position:0% +bread crumbs maybe one egg so everything + + + align:start position:0% +bread crumbs maybe one egg so everything +sticks together a little bit of cheese + + align:start position:0% +sticks together a little bit of cheese + + + align:start position:0% +sticks together a little bit of cheese +you make + + align:start position:0% +you make + + + align:start position:0% +you make +some little balls like meatballs + + align:start position:0% +some little balls like meatballs + + + align:start position:0% +some little balls like meatballs +and then you either fry them or you can + + align:start position:0% +and then you either fry them or you can + + + align:start position:0% +and then you either fry them or you can +bake them + + align:start position:0% +bake them + + + align:start position:0% +bake them +or you can cook them at low heat in a + + align:start position:0% +or you can cook them at low heat in a + + + align:start position:0% +or you can cook them at low heat in a +pan maybe you can add some pasade + + align:start position:0% +pan maybe you can add some pasade + + + align:start position:0% +pan maybe you can add some pasade +pomodoro there are a lot of different + + align:start position:0% +pomodoro there are a lot of different + + + align:start position:0% +pomodoro there are a lot of different +qualities so epileptic + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/F6H50Hbulbk.txt b/F6H50Hbulbk.txt new file mode 100644 index 0000000000000000000000000000000000000000..53ee888ee8695521f7a0f42aab4e74e120456dff --- /dev/null +++ b/F6H50Hbulbk.txt @@ -0,0 +1,225 @@ +We now come to a very important +concept, the concept + +of independence of +random variables. + +We are already familiar with the +notion of independence of + +two events. + +We have the mathematical +definition, and the + +interpretation is that +conditional probabilities are + +the same as unconditional +ones. + +Intuitively, when you are told +that B occurred, this does not + +change your beliefs about A, +and so the conditional + +probability of A is the same +as the unconditional + +probability. + +We have a similar definition +of independence of a random + +variable and an event A. The +mathematical definition is + +that event A and the event that +X takes on a specific + +value, that these two events +are independent in the + +ordinary sense. + +So the probability of both of +these events happening is the + +product of their individual +probabilities. + +But we require this to be true +for all values of little x. + +Intuitively, if I tell you that +A occurred, this is not + +going to change the distribution +of the random + +variable x. + +This is one interpretation of +what independence means in + +this context. + +And this has to be true for all +values of little x, that + +is, when [the] + +event occurs, the probabilities +of any + +particular little x [are] + +going to be the same as the +original unconditional + +probabilities. + +We also have a symmetrical +interpretation. + +If I tell you the value of +X, then the conditional + +probability of event A is +not going to change. + +It's going to be the same as the +unconditional probability. + +And again, this is going to be +the case for all values of X. + +So, no matter what they tell +you about X, your beliefs + +about A are not going +to change. + +We can now move and define the +notion of independence of two + +random variables. + +The mathematical definition is +that the event that X takes on + +a value little x and the event +that Y takes on a value little + +y, these two events are +independent, and this is true + +for all possible values of +little x and little y. + +In PMF notation, this +relation here can be + +written in this form. + +And basically, the joint PMF +factors out as a product of + +the marginal PMFs of the +two random variables. + +Again, this relation has to be +true for all possible little x + +and little y. + +What does independence mean? + +When I tell you the value of y, +and no matter what value I + +tell you, your beliefs about +X will not change. + +So that the conditional PMF of +X given Y is going to be the + +same as the unconditional PMF of +X. And this has to be true + +for any values of the arguments +of these PMFs. + +There is also a symmetric +interpretation, which is that + +the conditional PMF of Y given +X is going to be the same as + +the unconditional PMF of Y. +We have the symmetric + +interpretation because, as we +can see from this definition, + +X and Y have symmetric roles. + +Finally, we can define the +notion of independence of + +multiple random variables +by a similar relation. + +Here, the definition is for +the case of three random + +variables, but you can imagine +how the definition for any + +finite number of random +variables will go. + +Namely, the joint PMF of all +the random variables can be + +expressed as the product of the + +corresponding marginal PMFs. + +What is the intuitive +interpretation of + +independence here? + +It means that information +about some of the random + +variables will not change your +beliefs, the probabilities, + +about the remaining +random variables. + +Any conditional probabilities +and any conditional PMFs will + +be the same as the unconditional +ones. + +In the real world, independence +models situations + +where each of the random +variables is generated in a + +decoupled manner, in a separate +probabilistic + +experiment. + +And these probabilistic +experiments do not interact + +with each other and have no +common sources of uncertainty. \ No newline at end of file diff --git a/FrrTXj13DNk.txt b/FrrTXj13DNk.txt new file mode 100644 index 0000000000000000000000000000000000000000..3aadf23b98dfe41e54d05015d3774de9bed38d5f --- /dev/null +++ b/FrrTXj13DNk.txt @@ -0,0 +1,7795 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so you see that uh I thought + + align:start position:0% +ocw.mit.edu so you see that uh I thought + + + align:start position:0% +ocw.mit.edu so you see that uh I thought +maybe we've got enough uh good + + align:start position:0% +maybe we've got enough uh good + + + align:start position:0% +maybe we've got enough uh good +examples in theory where we need some + + align:start position:0% +examples in theory where we need some + + + align:start position:0% +examples in theory where we need some +practice we need some uh + + align:start position:0% +practice we need some uh + + + align:start position:0% +practice we need some uh +exper experiments with some of the + + align:start position:0% +exper experiments with some of the + + + align:start position:0% +exper experiments with some of the +finite difference methods that we've + + align:start position:0% +finite difference methods that we've + + + align:start position:0% +finite difference methods that we've +spoken about so I created this homework + + align:start position:0% +spoken about so I created this homework + + + align:start position:0% +spoken about so I created this homework +in which you would like choose one of + + align:start position:0% +in which you would like choose one of + + + align:start position:0% +in which you would like choose one of +these uh that we've done well actually + + align:start position:0% +these uh that we've done well actually + + + align:start position:0% +these uh that we've done well actually +number + + align:start position:0% +number + + + align:start position:0% +number +two uh the shinger equation which has + + align:start position:0% +two uh the shinger equation which has + + + align:start position:0% +two uh the shinger equation which has +that imaginary I in there uh we haven't + + align:start position:0% +that imaginary I in there uh we haven't + + + align:start position:0% +that imaginary I in there uh we haven't +spoken about yet so uh but you could um + + align:start position:0% +spoken about yet so uh but you could um + + + align:start position:0% +spoken about yet so uh but you could um +do the kind of fora analysis that we've + + align:start position:0% +do the kind of fora analysis that we've + + + align:start position:0% +do the kind of fora analysis that we've +done for the heat equation but of course + + align:start position:0% +done for the heat equation but of course + + + align:start position:0% +done for the heat equation but of course +it's going to be different because of + + align:start position:0% +it's going to be different because of + + + align:start position:0% +it's going to be different because of +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +I we you'll get an e to the minus i k 2 + + align:start position:0% +I we you'll get an e to the minus i k 2 + + + align:start position:0% +I we you'll get an e to the minus i k 2 +T I guess and that means that's a number + + align:start position:0% +T I guess and that means that's a number + + + align:start position:0% +T I guess and that means that's a number +of of uh absolute value one instead of a + + align:start position:0% +of of uh absolute value one instead of a + + + align:start position:0% +of of uh absolute value one instead of a +rapidly + + align:start position:0% +rapidly + + + align:start position:0% +rapidly +decaying uh coefficient okay so my idea + + align:start position:0% +decaying uh coefficient okay so my idea + + + align:start position:0% +decaying uh coefficient okay so my idea +is to choose one of those groups or a + + align:start position:0% +is to choose one of those groups or a + + + align:start position:0% +is to choose one of those groups or a +number five if you want + + align:start position:0% +number five if you want + + + align:start position:0% +number five if you want +and uh Say by next Friday uh just give + + align:start position:0% +and uh Say by next Friday uh just give + + + align:start position:0% +and uh Say by next Friday uh just give +me some + + align:start position:0% +me some + + + align:start position:0% +me some +uh uh experiment with a + + align:start position:0% + + + + align:start position:0% + +code in this case you could use well we + + align:start position:0% +code in this case you could use well we + + + align:start position:0% +code in this case you could use well we +have four methods and three of them are + + align:start position:0% +have four methods and three of them are + + + align:start position:0% +have four methods and three of them are +already uh in code and you're welcome to + + align:start position:0% +already uh in code and you're welcome to + + + align:start position:0% +already uh in code and you're welcome to +use those or your own and and I raised + + align:start position:0% +use those or your own and and I raised + + + align:start position:0% +use those or your own and and I raised +questions last time and I'll put this on + + align:start position:0% +questions last time and I'll put this on + + + align:start position:0% +questions last time and I'll put this on +the website with a little more detail so + + align:start position:0% +the website with a little more detail so + + + align:start position:0% +the website with a little more detail so +ju just to give you an idea of what's + + align:start position:0% +ju just to give you an idea of what's + + + align:start position:0% +ju just to give you an idea of what's +coming uh so this is the problem that + + align:start position:0% +coming uh so this is the problem that + + + align:start position:0% +coming uh so this is the problem that +we're in the middle of speaking about + + align:start position:0% +we're in the middle of speaking about + + + align:start position:0% +we're in the middle of speaking about +near the end the mixture of convection + + align:start position:0% +near the end the mixture of convection + + + align:start position:0% +near the end the mixture of convection +and + + align:start position:0% +and + + + align:start position:0% +and +diffusion and this is shringer which is + + align:start position:0% +diffusion and this is shringer which is + + + align:start position:0% +diffusion and this is shringer which is +new this is the advection equation or + + align:start position:0% +new this is the advection equation or + + + align:start position:0% +new this is the advection equation or +the one-way wave equation which we've + + align:start position:0% +the one-way wave equation which we've + + + align:start position:0% +the one-way wave equation which we've +started with and this is what's this + + align:start position:0% +started with and this is what's this + + + align:start position:0% +started with and this is what's this +will be the subject of today's lecture + + align:start position:0% +will be the subject of today's lecture + + + align:start position:0% +will be the subject of today's lecture +and and next time and the best uh + + align:start position:0% +and and next time and the best uh + + + align:start position:0% +and and next time and the best uh +reference I can give as well as the + + align:start position:0% +reference I can give as well as the + + + align:start position:0% +reference I can give as well as the +textbook the applied math book has + + align:start position:0% +textbook the applied math book has + + + align:start position:0% +textbook the applied math book has +uh significant uh discussion of of of + + align:start position:0% +uh significant uh discussion of of of + + + align:start position:0% +uh significant uh discussion of of of +this conservation law but also it was + + align:start position:0% +this conservation law but also it was + + + align:start position:0% +this conservation law but also it was +it's very well presented in the 16920 + + align:start position:0% +it's very well presented in the 16920 + + + align:start position:0% +it's very well presented in the 16920 +lecture notes that are on open + + align:start position:0% +lecture notes that are on open + + + align:start position:0% +lecture notes that are on open +courseware lectures 11 and 12 so I'm I'm + + align:start position:0% +courseware lectures 11 and 12 so I'm I'm + + + align:start position:0% +courseware lectures 11 and 12 so I'm I'm +I'm going to use those as a guide in in + + align:start position:0% +I'm going to use those as a guide in in + + + align:start position:0% +I'm going to use those as a guide in in +this + + align:start position:0% +this + + + align:start position:0% +this +lecture anyway we can I thought i' just + + align:start position:0% +lecture anyway we can I thought i' just + + + align:start position:0% +lecture anyway we can I thought i' just +uh uh put that up as uh + + align:start position:0% +uh uh put that up as uh + + + align:start position:0% +uh uh put that up as uh +um you know time to see + + align:start position:0% +um you know time to see + + + align:start position:0% +um you know time to see +what what various difference methods + + align:start position:0% +what what various difference methods + + + align:start position:0% +what what various difference methods +will + + align:start position:0% +will + + + align:start position:0% +will +do and uh and again it'll be on the + + align:start position:0% +do and uh and again it'll be on the + + + align:start position:0% +do and uh and again it'll be on the +website okay then now to to say another + + align:start position:0% +website okay then now to to say another + + + align:start position:0% +website okay then now to to say another +word about this uh this one this + + align:start position:0% +word about this uh this one this + + + align:start position:0% +word about this uh this one this +uh convection diffusion equation + + align:start position:0% +uh convection diffusion equation + + + align:start position:0% +uh convection diffusion equation +so last time I wrote down a difference + + align:start position:0% +so last time I wrote down a difference + + + align:start position:0% +so last time I wrote down a difference +equation very much like + + align:start position:0% +equation very much like + + + align:start position:0% +equation very much like +that except what I wrote down last time + + align:start position:0% +that except what I wrote down last time + + + align:start position:0% +that except what I wrote down last time +was upwinded so that was just + + align:start position:0% +was upwinded so that was just + + + align:start position:0% +was upwinded so that was just +J now it's j minus + + align:start position:0% +J now it's j minus + + + align:start position:0% +J now it's j minus +one and the choice there is not clear + + align:start position:0% +one and the choice there is not clear + + + align:start position:0% +one and the choice there is not clear +this gives us uh higher accuracy of + + align:start position:0% +this gives us uh higher accuracy of + + + align:start position:0% +this gives us uh higher accuracy of +course for + + align:start position:0% +course for + + + align:start position:0% +course for +that X difference because it's centered + + align:start position:0% +that X difference because it's centered + + + align:start position:0% +that X difference because it's centered +at + + align:start position:0% + + + + align:start position:0% + +J and we still have this centered of + + align:start position:0% +J and we still have this centered of + + + align:start position:0% +J and we still have this centered of +course the second difference is centered + + align:start position:0% +course the second difference is centered + + + align:start position:0% +course the second difference is centered +here so I wrote down here what the uh + + align:start position:0% +here so I wrote down here what the uh + + + align:start position:0% +here so I wrote down here what the uh +coefficients are of the three old values + + align:start position:0% +coefficients are of the three old values + + + align:start position:0% +coefficients are of the three old values +at J + one at J and at J minus one but + + align:start position:0% +at J + one at J and at J minus one but + + + align:start position:0% +at J + one at J and at J minus one but +there's one uh + + align:start position:0% +there's one uh + + + align:start position:0% +there's one uh +important Point + + align:start position:0% +important Point + + + align:start position:0% +important Point +here uh the price for that extra + + align:start position:0% +here uh the price for that extra + + + align:start position:0% +here uh the price for that extra +accuracy was Poss may possibly + + align:start position:0% +accuracy was Poss may possibly + + + align:start position:0% +accuracy was Poss may possibly +be a negative coefficient this could be + + align:start position:0% +be a negative coefficient this could be + + + align:start position:0% +be a negative coefficient this could be +negative or it could be positive it + + align:start position:0% +negative or it could be positive it + + + align:start position:0% +negative or it could be positive it +depends which is more important the + + align:start position:0% +depends which is more important the + + + align:start position:0% +depends which is more important the +small R the the convection part or the + + align:start position:0% +small R the the convection part or the + + + align:start position:0% +small R the the convection part or the +Big R and uh let let me let me uh follow + + align:start position:0% +Big R and uh let let me let me uh follow + + + align:start position:0% +Big R and uh let let me let me uh follow +up so you you remember the price that if + + align:start position:0% +up so you you remember the price that if + + + align:start position:0% +up so you you remember the price that if +if we see a negative + + align:start position:0% +if we see a negative + + + align:start position:0% +if we see a negative +coefficient then we uh have we expect + + align:start position:0% +coefficient then we uh have we expect + + + align:start position:0% +coefficient then we uh have we expect +some oscillations to appear and actually + + align:start position:0% +some oscillations to appear and actually + + + align:start position:0% +some oscillations to appear and actually +they were supposed to appear in figure + + align:start position:0% +they were supposed to appear in figure + + + align:start position:0% +they were supposed to appear in figure +512 but it hasn't been done yet and if + + align:start position:0% +512 but it hasn't been done yet and if + + + align:start position:0% +512 but it hasn't been done yet and if +you would choose this one and do figure + + align:start position:0% +you would choose this one and do figure + + + align:start position:0% +you would choose this one and do figure +512 I'll would be incredibly + + align:start position:0% +512 I'll would be incredibly + + + align:start position:0% +512 I'll would be incredibly +grateful so figure 512 was to show uh + + align:start position:0% +grateful so figure 512 was to show uh + + + align:start position:0% +grateful so figure 512 was to show uh +the evolution of a from a un not uh for + + align:start position:0% +the evolution of a from a un not uh for + + + align:start position:0% +the evolution of a from a un not uh for +the convection + + align:start position:0% +the convection + + + align:start position:0% +the convection +diffusion okay so can I + + align:start position:0% +diffusion okay so can I + + + align:start position:0% +diffusion okay so can I +just do you see that in comparing r with + + align:start position:0% +just do you see that in comparing r with + + + align:start position:0% +just do you see that in comparing r with +r over + + align:start position:0% +r over + + + align:start position:0% +r over +two we're those are dimensionless + + align:start position:0% +two we're those are dimensionless + + + align:start position:0% +two we're those are dimensionless +quantities right can I can I take + + align:start position:0% +quantities right can I can I take + + + align:start position:0% +quantities right can I can I take +another minute to try I'm a total + + align:start position:0% +another minute to try I'm a total + + + align:start position:0% +another minute to try I'm a total +amateur at uh dimensional + + align:start position:0% + + + + align:start position:0% + +analysis I did always think however + + align:start position:0% +analysis I did always think however + + + align:start position:0% +analysis I did always think however +that Einstein could have proved well not + + align:start position:0% +that Einstein could have proved well not + + + align:start position:0% +that Einstein could have proved well not +maybe proved but could have conjectured + + align:start position:0% +maybe proved but could have conjectured + + + align:start position:0% +maybe proved but could have conjectured +that e was mc^ s the most important + + align:start position:0% +that e was mc^ s the most important + + + align:start position:0% +that e was mc^ s the most important +equation in relativity just by checking + + align:start position:0% +equation in relativity just by checking + + + align:start position:0% +equation in relativity just by checking +the + + align:start position:0% +the + + + align:start position:0% +the +dimensions I don't know if that would I + + align:start position:0% +dimensions I don't know if that would I + + + align:start position:0% +dimensions I don't know if that would I +mean right that would like might might + + align:start position:0% +mean right that would like might might + + + align:start position:0% +mean right that would like might might +have occurred to him to realize that mc^ + + align:start position:0% +have occurred to him to realize that mc^ + + + align:start position:0% +have occurred to him to realize that mc^ +s has the dimensions if we wrote those + + align:start position:0% +s has the dimensions if we wrote those + + + align:start position:0% +s has the dimensions if we wrote those +out of + + align:start position:0% +out of + + + align:start position:0% +out of +energy I don't know if that uh put an + + align:start position:0% +energy I don't know if that uh put an + + + align:start position:0% +energy I don't know if that uh put an +idea + + align:start position:0% +idea + + + align:start position:0% +idea +uh into the into the system which + + align:start position:0% +uh into the into the system which + + + align:start position:0% +uh into the into the system which +produced of course that the fact that + + align:start position:0% +produced of course that the fact that + + + align:start position:0% +produced of course that the fact that +and of course there would be a + + align:start position:0% +and of course there would be a + + + align:start position:0% +and of course there would be a +dimensionless constant which amazingly + + align:start position:0% +dimensionless constant which amazingly + + + align:start position:0% +dimensionless constant which amazingly +happens to be + + align:start position:0% +happens to be + + + align:start position:0% +happens to be +one okay so dimensional analysis could + + align:start position:0% +one okay so dimensional analysis could + + + align:start position:0% +one okay so dimensional analysis could +like change the world this won't quite + + align:start position:0% +like change the world this won't quite + + + align:start position:0% +like change the world this won't quite +change the world but a little a little + + align:start position:0% +change the world but a little a little + + + align:start position:0% +change the world but a little a little +touch of of uh something okay so can I + + align:start position:0% +touch of of uh something okay so can I + + + align:start position:0% +touch of of uh something okay so can I +just uh uh you remember that this PE + + align:start position:0% +just uh uh you remember that this PE + + + align:start position:0% +just uh uh you remember that this PE +number and I'll write his name down + + align:start position:0% +number and I'll write his name down + + + align:start position:0% +number and I'll write his name down +again p c e t the peklay number in the + + align:start position:0% +again p c e t the peklay number in the + + + align:start position:0% +again p c e t the peklay number in the +uh differential equation the peklay + + align:start position:0% +uh differential equation the peklay + + + align:start position:0% +uh differential equation the peklay +number + + align:start position:0% +number + + + align:start position:0% +number +was a ratio essentially a ratio of + + align:start position:0% +was a ratio essentially a ratio of + + + align:start position:0% +was a ratio essentially a ratio of +C to D but to get the uh I think we + + align:start position:0% +C to D but to get the uh I think we + + + align:start position:0% +C to D but to get the uh I think we +needed was that what we + + align:start position:0% +needed was that what we + + + align:start position:0% +needed was that what we +needed we needed a we needed a length + + align:start position:0% +needed we needed a we needed a length + + + align:start position:0% +needed we needed a we needed a length +to make it + + align:start position:0% +to make it + + + align:start position:0% +to make it +dimensionless C is the coefficient for C + + align:start position:0% +dimensionless C is the coefficient for C + + + align:start position:0% +dimensionless C is the coefficient for C +over D sort of tells us roughly the + + align:start position:0% +over D sort of tells us roughly the + + + align:start position:0% +over D sort of tells us roughly the +importance of convection and diffusion + + align:start position:0% +importance of convection and diffusion + + + align:start position:0% +importance of convection and diffusion +but we but there's a length scale to be + + align:start position:0% +but we but there's a length scale to be + + + align:start position:0% +but we but there's a length scale to be +included now the cell Peekay + + align:start position:0% + + + + align:start position:0% + +number which I'll just call P I'm just + + align:start position:0% +number which I'll just call P I'm just + + + align:start position:0% +number which I'll just call P I'm just +going to take to be R over R because + + align:start position:0% +going to take to be R over R because + + + align:start position:0% +going to take to be R over R because +those are dimensionals + + align:start position:0% + + + + align:start position:0% + +and you see that it's going to play a + + align:start position:0% +and you see that it's going to play a + + + align:start position:0% +and you see that it's going to play a +part + + align:start position:0% +part + + + align:start position:0% +part +here uh let me see I forg uh I think I + + align:start position:0% +here uh let me see I forg uh I think I + + + align:start position:0% +here uh let me see I forg uh I think I +want R over R uh maybe I want a + + align:start position:0% +want R over R uh maybe I want a + + + align:start position:0% +want R over R uh maybe I want a +two just because I would like that to + + align:start position:0% +two just because I would like that to + + + align:start position:0% +two just because I would like that to +I'd like it to come out Simply there + + align:start position:0% +I'd like it to come out Simply there + + + align:start position:0% +I'd like it to come out Simply there +right okay uh so I may put in a two so + + align:start position:0% +right okay uh so I may put in a two so + + + align:start position:0% +right okay uh so I may put in a two so +that R would be two RP where did that + + align:start position:0% +that R would be two RP where did that + + + align:start position:0% +that R would be two RP where did that +two come from by the way I guess it came + + align:start position:0% +two come from by the way I guess it came + + + align:start position:0% +two come from by the way I guess it came +from there right that was the that was + + align:start position:0% +from there right that was the that was + + + align:start position:0% +from there right that was the that was +it came from that minus 12 so probably I + + align:start position:0% +it came from that minus 12 so probably I + + + align:start position:0% +it came from that minus 12 so probably I +want a two there just so that I have a + + align:start position:0% +want a two there just so that I have a + + + align:start position:0% +want a two there just so that I have a +very simple decision of whether + + align:start position:0% +very simple decision of whether + + + align:start position:0% +very simple decision of whether +this uh coefficient is positive or + + align:start position:0% +this uh coefficient is positive or + + + align:start position:0% +this uh coefficient is positive or +negative yeah uh let me so let me put in + + align:start position:0% +negative yeah uh let me so let me put in + + + align:start position:0% +negative yeah uh let me so let me put in +a + + align:start position:0% +a + + + align:start position:0% +a +two okay so r/2 is RP then this this + + align:start position:0% +two okay so r/2 is RP then this this + + + align:start position:0% +two okay so r/2 is RP then this this +quantity is R * P so this is r - R * P + + align:start position:0% +quantity is R * P so this is r - R * P + + + align:start position:0% +quantity is R * P so this is r - R * P +or it's R which we know is okay Time 1 + + align:start position:0% +or it's R which we know is okay Time 1 + + + align:start position:0% +or it's R which we know is okay Time 1 +minus p in other words P smaller than + + align:start position:0% +minus p in other words P smaller than + + + align:start position:0% +minus p in other words P smaller than +one that coefficient all the three + + align:start position:0% +one that coefficient all the three + + + align:start position:0% +one that coefficient all the three +coefficients are positive it's certainly + + align:start position:0% +coefficients are positive it's certainly + + + align:start position:0% +coefficients are positive it's certainly +stable not only stable it can't + + align:start position:0% +stable not only stable it can't + + + align:start position:0% +stable not only stable it can't +oscillate it we can't have uh we're + + align:start position:0% +oscillate it we can't have uh we're + + + align:start position:0% +oscillate it we can't have uh we're +taking a combination of the three old + + align:start position:0% +taking a combination of the three old + + + align:start position:0% +taking a combination of the three old +values and uh oscillations can't show up + + align:start position:0% +values and uh oscillations can't show up + + + align:start position:0% +values and uh oscillations can't show up +okay so just to see what is this then + + align:start position:0% +okay so just to see what is this then + + + align:start position:0% +okay so just to see what is this then +you remember that R is C delta T over + + align:start position:0% +you remember that R is C delta T over + + + align:start position:0% +you remember that R is C delta T over +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X + + align:start position:0% +X + + + align:start position:0% +X +and capital r is D delta T over Delta + + align:start position:0% +and capital r is D delta T over Delta + + + align:start position:0% +and capital r is D delta T over Delta +x^2 so just to complete this uh the + + align:start position:0% +x^2 so just to complete this uh the + + + align:start position:0% +x^2 so just to complete this uh the +Delta T's cancel one of the Delta X + + align:start position:0% +Delta T's cancel one of the Delta X + + + align:start position:0% +Delta T's cancel one of the Delta X +cancels the other one comes up so it's C + + align:start position:0% +cancels the other one comes up so it's C + + + align:start position:0% +cancels the other one comes up so it's C +over + + align:start position:0% +over + + + align:start position:0% +over +D and we have a Delta X and A + + align:start position:0% + + + + align:start position:0% + +2 so that's why it's called the cell pay + + align:start position:0% +2 so that's why it's called the cell pay + + + align:start position:0% +2 so that's why it's called the cell pay +number because it's the cell size or in + + align:start position:0% +number because it's the cell size or in + + + align:start position:0% +number because it's the cell size or in +my convention half the cell size that uh + + align:start position:0% +my convention half the cell size that uh + + + align:start position:0% +my convention half the cell size that uh +gives the length scale and uh decides + + align:start position:0% +gives the length scale and uh decides + + + align:start position:0% +gives the length scale and uh decides +whether p is so so I'm just going to + + align:start position:0% +whether p is so so I'm just going to + + + align:start position:0% +whether p is so so I'm just going to +write down the conclusion that that the + + align:start position:0% +write down the conclusion that that the + + + align:start position:0% +write down the conclusion that that the +figure should show uh P smaller than + + align:start position:0% +figure should show uh P smaller than + + + align:start position:0% +figure should show uh P smaller than +one that means that this coefficient is + + align:start position:0% +one that means that this coefficient is + + + align:start position:0% +one that means that this coefficient is +also positive so that's positive + + align:start position:0% +also positive so that's positive + + + align:start position:0% +also positive so that's positive +coefficients no + + align:start position:0% + + + + align:start position:0% + +oscillation and I think you'll see in + + align:start position:0% +oscillation and I think you'll see in + + + align:start position:0% +oscillation and I think you'll see in +the in from the from the output that P + + align:start position:0% +the in from the from the output that P + + + align:start position:0% +the in from the from the output that P +bigger than one produces + + align:start position:0% +bigger than one produces + + + align:start position:0% +bigger than one produces +is oscillation we we don't + + align:start position:0% +is oscillation we we don't + + + align:start position:0% +is oscillation we we don't +like in other words we we really don't + + align:start position:0% +like in other words we we really don't + + + align:start position:0% +like in other words we we really don't +want P larger than + + align:start position:0% + + + + align:start position:0% + +one and uh uh of course you could say + + align:start position:0% +one and uh uh of course you could say + + + align:start position:0% +one and uh uh of course you could say +well look at P it's got a Delta X in it + + align:start position:0% +well look at P it's got a Delta X in it + + + align:start position:0% +well look at P it's got a Delta X in it +that's not that's not going to be a big + + align:start position:0% + + + + align:start position:0% + +number and and and the method will work + + align:start position:0% +number and and and the method will work + + + align:start position:0% +number and and and the method will work +fine as Delta X and delta T go to zero + + align:start position:0% + + + + align:start position:0% + +but uh we're going to do a finite + + align:start position:0% +but uh we're going to do a finite + + + align:start position:0% +but uh we're going to do a finite +calculation and so we're seeing for the + + align:start position:0% +calculation and so we're seeing for the + + + align:start position:0% +calculation and so we're seeing for the +first time like because we have two + + align:start position:0% +first time like because we have two + + + align:start position:0% +first time like because we have two +terms that are not dimensionally + + align:start position:0% +terms that are not dimensionally + + + align:start position:0% +terms that are not dimensionally +identical see and D that + + align:start position:0% +identical see and D that + + + align:start position:0% +identical see and D that +uh in that in that competition between + + align:start position:0% +uh in that in that competition between + + + align:start position:0% +uh in that in that competition between +convection and diffusion the length + + align:start position:0% +convection and diffusion the length + + + align:start position:0% +convection and diffusion the length +scale is crucial and the and the mes + + align:start position:0% +scale is crucial and the and the mes + + + align:start position:0% +scale is crucial and the and the mes +size is crucial + + align:start position:0% + + + + align:start position:0% + +so I guess the answer is we can resolve + + align:start position:0% +so I guess the answer is we can resolve + + + align:start position:0% +so I guess the answer is we can resolve +it by taking Delta X small enough and + + align:start position:0% +it by taking Delta X small enough and + + + align:start position:0% +it by taking Delta X small enough and +hopefully that's not a problem but of + + align:start position:0% +hopefully that's not a problem but of + + + align:start position:0% +hopefully that's not a problem but of +course you you know that + + align:start position:0% +course you you know that + + + align:start position:0% +course you you know that +uh there are many physical cases in + + align:start position:0% +uh there are many physical cases in + + + align:start position:0% +uh there are many physical cases in +which uh the diffusion coefficient or + + align:start position:0% +which uh the diffusion coefficient or + + + align:start position:0% +which uh the diffusion coefficient or +the viscosity coefficient the is small + + align:start position:0% +the viscosity coefficient the is small + + + align:start position:0% +the viscosity coefficient the is small +is quite small and uh so getting that + + align:start position:0% +is quite small and uh so getting that + + + align:start position:0% +is quite small and uh so getting that +below one might be hard because this D + + align:start position:0% +below one might be hard because this D + + + align:start position:0% +below one might be hard because this D +could be a very small number + + align:start position:0% +could be a very small number + + + align:start position:0% +could be a very small number +yeah okay so that I + + align:start position:0% +yeah okay so that I + + + align:start position:0% +yeah okay so that I +won't maybe can I also mention on the as + + align:start position:0% +won't maybe can I also mention on the as + + + align:start position:0% +won't maybe can I also mention on the as +something that we haven't done here was + + align:start position:0% +something that we haven't done here was + + + align:start position:0% +something that we haven't done here was +to move uh the the + + align:start position:0% +to move uh the the + + + align:start position:0% +to move uh the the +uh the the second derivative this guy to + + align:start position:0% +uh the the second derivative this guy to + + + align:start position:0% +uh the the second derivative this guy to +to time n + + align:start position:0% +to time n + + + align:start position:0% +to time n ++1 make it implicit the the diffusion + + align:start position:0% ++1 make it implicit the the diffusion + + + align:start position:0% ++1 make it implicit the the diffusion +part one often does that the diffusion + + align:start position:0% +part one often does that the diffusion + + + align:start position:0% +part one often does that the diffusion +is + + align:start position:0% +is + + + align:start position:0% +is +the term is the one that's forcing us to + + align:start position:0% +the term is the one that's forcing us to + + + align:start position:0% +the term is the one that's forcing us to +take this uh coefficient + + align:start position:0% + + + + align:start position:0% + +R below a half delta T of order Delta X2 + + align:start position:0% +R below a half delta T of order Delta X2 + + + align:start position:0% +R below a half delta T of order Delta X2 +and the way to avoid that is to move the + + align:start position:0% +and the way to avoid that is to move the + + + align:start position:0% +and the way to avoid that is to move the +VIS City term at least half of it up to + + align:start position:0% +VIS City term at least half of it up to + + + align:start position:0% +VIS City term at least half of it up to +the uh up to the new time okay so that's + + align:start position:0% +the uh up to the new time okay so that's + + + align:start position:0% +the uh up to the new time okay so that's +a third method so we've done + + align:start position:0% +a third method so we've done + + + align:start position:0% +a third method so we've done +upwind last time uh centered explicit + + align:start position:0% +upwind last time uh centered explicit + + + align:start position:0% +upwind last time uh centered explicit +this time but then that's a third one + + align:start position:0% +this time but then that's a third one + + + align:start position:0% +this time but then that's a third one +that's uh has to be looked at okay so + + align:start position:0% +that's uh has to be looked at okay so + + + align:start position:0% +that's uh has to be looked at okay so +those those are that that's where uh + + align:start position:0% +those those are that that's where uh + + + align:start position:0% +those those are that that's where uh +um we stand on linear problems + + align:start position:0% + + + + align:start position:0% + +uh I I'm sort of ready to jump into + + align:start position:0% +uh I I'm sort of ready to jump into + + + align:start position:0% +uh I I'm sort of ready to jump into +nonlinear + + align:start position:0% +nonlinear + + + align:start position:0% +nonlinear +ones recognizing that there well there's + + align:start position:0% +ones recognizing that there well there's + + + align:start position:0% +ones recognizing that there well there's +always more to say about linear ones + + align:start position:0% +always more to say about linear ones + + + align:start position:0% +always more to say about linear ones +what are some of the things that we have + + align:start position:0% +what are some of the things that we have + + + align:start position:0% +what are some of the things that we have +not properly discussed boundary + + align:start position:0% +not properly discussed boundary + + + align:start position:0% +not properly discussed boundary +conditions above + + align:start position:0% +conditions above + + + align:start position:0% +conditions above +all boundary conditions we and we could + + align:start position:0% +all boundary conditions we and we could + + + align:start position:0% +all boundary conditions we and we could +we we could uh do something with those + + align:start position:0% +we we could uh do something with those + + + align:start position:0% +we we could uh do something with those +we could and the notes will uh say more + + align:start position:0% +we could and the notes will uh say more + + + align:start position:0% +we could and the notes will uh say more +about boundary conditions so there are + + align:start position:0% +about boundary conditions so there are + + + align:start position:0% +about boundary conditions so there are +several types of boundary conditions I I + + align:start position:0% +several types of boundary conditions I I + + + align:start position:0% +several types of boundary conditions I I +guess I'm going to say something about + + align:start position:0% +guess I'm going to say something about + + + align:start position:0% +guess I'm going to say something about +them now but this will be a board that + + align:start position:0% +them now but this will be a board that + + + align:start position:0% +them now but this will be a board that +kind of gets covered up so boundary + + align:start position:0% +kind of gets covered up so boundary + + + align:start position:0% +kind of gets covered up so boundary +conditions so what are the different + + align:start position:0% +conditions so what are the different + + + align:start position:0% +conditions so what are the different +types well at a real physical boundary + + align:start position:0% +types well at a real physical boundary + + + align:start position:0% +types well at a real physical boundary +we might have U equal 0 say in heat + + align:start position:0% + + + + align:start position:0% + +flow we might hold the boundary it might + + align:start position:0% +flow we might hold the boundary it might + + + align:start position:0% +flow we might hold the boundary it might +be the edge of a freezer or something we + + align:start position:0% +be the edge of a freezer or something we + + + align:start position:0% +be the edge of a freezer or something we +might hold the temperature at zero or or + + align:start position:0% +might hold the temperature at zero or or + + + align:start position:0% +might hold the temperature at zero or or +at some at some given value we might + + align:start position:0% +at some at some given value we might + + + align:start position:0% +at some at some given value we might +prescribe U at a + + align:start position:0% +prescribe U at a + + + align:start position:0% +prescribe U at a +boundary or we might prescribe the + + align:start position:0% +boundary or we might prescribe the + + + align:start position:0% +boundary or we might prescribe the +derivative and just in case we're in + + align:start position:0% +derivative and just in case we're in + + + align:start position:0% +derivative and just in case we're in +several Dimensions I'll better write it + + align:start position:0% +several Dimensions I'll better write it + + + align:start position:0% +several Dimensions I'll better write it +as the outgoing derivative could be + + align:start position:0% +as the outgoing derivative could be + + + align:start position:0% +as the outgoing derivative could be +prescribed say Z + + align:start position:0% + + + + align:start position:0% + +so what are those two types of boundary + + align:start position:0% +so what are those two types of boundary + + + align:start position:0% +so what are those two types of boundary +conditions called one's called absorbing + + align:start position:0% +conditions called one's called absorbing + + + align:start position:0% +conditions called one's called absorbing +an absorbing boundary and the other is + + align:start position:0% +an absorbing boundary and the other is + + + align:start position:0% +an absorbing boundary and the other is +an insulated boundary where uh no heat + + align:start position:0% +an insulated boundary where uh no heat + + + align:start position:0% +an insulated boundary where uh no heat +goes + + align:start position:0% +goes + + + align:start position:0% +goes +through to maintain this heat probably + + align:start position:0% +through to maintain this heat probably + + + align:start position:0% +through to maintain this heat probably +does go through if our if our body is + + align:start position:0% +does go through if our if our body is + + + align:start position:0% +does go through if our if our body is +warm and it's we're holding it at zero + + align:start position:0% +warm and it's we're holding it at zero + + + align:start position:0% +warm and it's we're holding it at zero +on its boundary then heat is going to + + align:start position:0% +on its boundary then heat is going to + + + align:start position:0% +on its boundary then heat is going to +travel out + + align:start position:0% +travel out + + + align:start position:0% +travel out +and in fact as time goes to Infinity + + align:start position:0% +and in fact as time goes to Infinity + + + align:start position:0% +and in fact as time goes to Infinity +we're going to approach a a + + align:start position:0% +we're going to approach a a + + + align:start position:0% +we're going to approach a a +cold a uniformally cold thing here + + align:start position:0% +cold a uniformally cold thing here + + + align:start position:0% +cold a uniformally cold thing here +heat's not allowed to travel out so what + + align:start position:0% +heat's not allowed to travel out so what + + + align:start position:0% +heat's not allowed to travel out so what +will happen as time goes on is it will + + align:start position:0% +will happen as time goes on is it will + + + align:start position:0% +will happen as time goes on is it will +uh um approach a constant the + + align:start position:0% +uh um approach a constant the + + + align:start position:0% +uh um approach a constant the +temperature will approach a constant + + align:start position:0% +temperature will approach a constant + + + align:start position:0% +temperature will approach a constant +because it can't leave and it diffuses + + align:start position:0% +because it can't leave and it diffuses + + + align:start position:0% +because it can't leave and it diffuses +and uh and now I wanted to + + align:start position:0% +and uh and now I wanted to + + + align:start position:0% +and uh and now I wanted to +mention a third type of boundary which + + align:start position:0% +mention a third type of boundary which + + + align:start position:0% +mention a third type of boundary which +is a purely computational boundary we we + + align:start position:0% +is a purely computational boundary we we + + + align:start position:0% +is a purely computational boundary we we +we talked last time about uh Maxwell's + + align:start position:0% +we talked last time about uh Maxwell's + + + align:start position:0% +we talked last time about uh Maxwell's +equations in free space and the big + + align:start position:0% +equations in free space and the big + + + align:start position:0% +equations in free space and the big +application of Maxwell's equations or + + align:start position:0% +application of Maxwell's equations or + + + align:start position:0% +application of Maxwell's equations or +one of the big ones historically has + + align:start position:0% +one of the big ones historically has + + + align:start position:0% +one of the big ones historically has +been to like the exterior of an airplane + + align:start position:0% +been to like the exterior of an airplane + + + align:start position:0% +been to like the exterior of an airplane +to radar or other electromagnetic + + align:start position:0% +to radar or other electromagnetic + + + align:start position:0% +to radar or other electromagnetic +signals so what do we do if we have an + + align:start position:0% +signals so what do we do if we have an + + + align:start position:0% +signals so what do we do if we have an +exterior problem see here I was always + + align:start position:0% +exterior problem see here I was always + + + align:start position:0% +exterior problem see here I was always +thinking about an interior problem you + + align:start position:0% +thinking about an interior problem you + + + align:start position:0% +thinking about an interior problem you +know we're we're inside zero to Zer to L + + align:start position:0% +know we're we're inside zero to Zer to L + + + align:start position:0% +know we're we're inside zero to Zer to L +or something but now what do we do if a + + align:start position:0% +or something but now what do we do if a + + + align:start position:0% +or something but now what do we do if a +region is the outside it's free space + + align:start position:0% +region is the outside it's free space + + + align:start position:0% +region is the outside it's free space +all the way well we have to create a + + align:start position:0% +all the way well we have to create a + + + align:start position:0% +all the way well we have to create a +computational box of some sort so we + + align:start position:0% +computational box of some sort so we + + + align:start position:0% +computational box of some sort so we +create a box in which we + + align:start position:0% +create a box in which we + + + align:start position:0% +create a box in which we +compute but but the boundaries of this + + align:start position:0% +compute but but the boundaries of this + + + align:start position:0% +compute but but the boundaries of this +box the X boundaries of it + + align:start position:0% +box the X boundaries of it + + + align:start position:0% +box the X boundaries of it +are purely artificial they're just + + align:start position:0% +are purely artificial they're just + + + align:start position:0% +are purely artificial they're just +because we can't compute to Infinity so + + align:start position:0% +because we can't compute to Infinity so + + + align:start position:0% +because we can't compute to Infinity so +waves travel in this + + align:start position:0% +waves travel in this + + + align:start position:0% +waves travel in this +box and they travel to the so you see + + align:start position:0% +box and they travel to the so you see + + + align:start position:0% +box and they travel to the so you see +what I mean here here's we're we're + + align:start position:0% +what I mean here here's we're we're + + + align:start position:0% +what I mean here here's we're we're +solving it in all this space except + + align:start position:0% +solving it in all this space except + + + align:start position:0% +solving it in all this space except +that's too much so we we that's a that's + + align:start position:0% +that's too much so we we that's a that's + + + align:start position:0% +that's too much so we we that's a that's +meant to be a very large box not a small + + align:start position:0% +meant to be a very large box not a small + + + align:start position:0% +meant to be a very large box not a small +as large as we can + + align:start position:0% +as large as we can + + + align:start position:0% +as large as we can +for + + align:start position:0% +for + + + align:start position:0% +for +but waves are still going to hit the + + align:start position:0% +but waves are still going to hit the + + + align:start position:0% +but waves are still going to hit the +boundary of that box okay what do we + + align:start position:0% +boundary of that box okay what do we + + + align:start position:0% +boundary of that box okay what do we +choose as boundary condition + + align:start position:0% +choose as boundary condition + + + align:start position:0% +choose as boundary condition +there if we don't want it to reflect + + align:start position:0% +there if we don't want it to reflect + + + align:start position:0% +there if we don't want it to reflect +back because it it's not the real it's + + align:start position:0% +back because it it's not the real it's + + + align:start position:0% +back because it it's not the real it's +not a real boundary so we have to create + + align:start position:0% +not a real boundary so we have to create + + + align:start position:0% +not a real boundary so we have to create +an I'll put ABC for absorbing boundary + + align:start position:0% +an I'll put ABC for absorbing boundary + + + align:start position:0% +an I'll put ABC for absorbing boundary +condition + + align:start position:0% +condition + + + align:start position:0% +condition +absorbing that a is for an absorbing + + align:start position:0% +absorbing that a is for an absorbing + + + align:start position:0% +absorbing that a is for an absorbing +boundary condition that that + + align:start position:0% +boundary condition that that + + + align:start position:0% +boundary condition that that +uh that and and the creation of these + + align:start position:0% +uh that and and the creation of these + + + align:start position:0% +uh that and and the creation of these +boundary conditions is a is an important + + align:start position:0% +boundary conditions is a is an important + + + align:start position:0% +boundary conditions is a is an important +topic within finite + + align:start position:0% +topic within finite + + + align:start position:0% +topic within finite +differences uh for Maxwell's equations + + align:start position:0% +differences uh for Maxwell's equations + + + align:start position:0% +differences uh for Maxwell's equations +uh a a good idea was produced and has + + align:start position:0% +uh a a good idea was produced and has + + + align:start position:0% +uh a a good idea was produced and has +has keeps being developed called + + align:start position:0% +has keeps being developed called + + + align:start position:0% +has keeps being developed called +perfectly matched layer the idea in that + + align:start position:0% +perfectly matched layer the idea in that + + + align:start position:0% +perfectly matched layer the idea in that +perfect Ally matched layer let me just + + align:start position:0% +perfect Ally matched layer let me just + + + align:start position:0% +perfect Ally matched layer let me just +write + + align:start position:0% +write + + + align:start position:0% +write +PML and I haven't seen this so much in + + align:start position:0% +PML and I haven't seen this so much in + + + align:start position:0% +PML and I haven't seen this so much in +other uh application areas the idea with + + align:start position:0% +other uh application areas the idea with + + + align:start position:0% +other uh application areas the idea with +this perfectly matched layer is to + + align:start position:0% +this perfectly matched layer is to + + + align:start position:0% +this perfectly matched layer is to +create a + + align:start position:0% +create a + + + align:start position:0% +create a +artificial um dialectric I guess a + + align:start position:0% +artificial um dialectric I guess a + + + align:start position:0% +artificial um dialectric I guess a +dialectric medium it would be in the in + + align:start position:0% +dialectric medium it would be in the in + + + align:start position:0% +dialectric medium it would be in the in +the electromagnetic case an + + align:start position:0% +the electromagnetic case an + + + align:start position:0% +the electromagnetic case an +artificial uh thin + + align:start position:0% +artificial uh thin + + + align:start position:0% +artificial uh thin +layer which + + align:start position:0% +layer which + + + align:start position:0% +layer which +has just the right properties to stop + + align:start position:0% +has just the right properties to stop + + + align:start position:0% +has just the right properties to stop +the wave and swallow + + align:start position:0% +the wave and swallow + + + align:start position:0% +the wave and swallow +it okay I could I'll put on the website + + align:start position:0% +it okay I could I'll put on the website + + + align:start position:0% +it okay I could I'll put on the website +references to um uh to that it's a + + align:start position:0% +references to um uh to that it's a + + + align:start position:0% +references to um uh to that it's a +bright idea and uh but uh not totally + + align:start position:0% +bright idea and uh but uh not totally + + + align:start position:0% +bright idea and uh but uh not totally +simple and uh when we change difference + + align:start position:0% +simple and uh when we change difference + + + align:start position:0% +simple and uh when we change difference +methods then that perfectly matched + + align:start position:0% +methods then that perfectly matched + + + align:start position:0% +methods then that perfectly matched +layer has to go with it okay + + align:start position:0% +layer has to go with it okay + + + align:start position:0% +layer has to go with it okay +that's my that's the end of my thoughts + + align:start position:0% +that's my that's the end of my thoughts + + + align:start position:0% +that's my that's the end of my thoughts +about linear problems for + + align:start position:0% +about linear problems for + + + align:start position:0% +about linear problems for +now we're coming back of course in a few + + align:start position:0% +now we're coming back of course in a few + + + align:start position:0% +now we're coming back of course in a few +weeks to + + align:start position:0% +weeks to + + + align:start position:0% +weeks to +um to solving large systems large linear + + align:start position:0% +um to solving large systems large linear + + + align:start position:0% +um to solving large systems large linear +systems the kind that we would meet if + + align:start position:0% +systems the kind that we would meet if + + + align:start position:0% +systems the kind that we would meet if +we use an implicit + + align:start position:0% +we use an implicit + + + align:start position:0% +we use an implicit +method or the kind that we meet if we're + + align:start position:0% +method or the kind that we meet if we're + + + align:start position:0% +method or the kind that we meet if we're +solving a steady state problem but for + + align:start position:0% +solving a steady state problem but for + + + align:start position:0% +solving a steady state problem but for +now let me go let me go + + align:start position:0% +now let me go let me go + + + align:start position:0% +now let me go let me go +to + + align:start position:0% +to + + + align:start position:0% +to +um that model + + align:start position:0% + + + + align:start position:0% + +equation and you see right away the + + align:start position:0% +equation and you see right away the + + + align:start position:0% +equation and you see right away the +difference between that equation and + + align:start position:0% +difference between that equation and + + + align:start position:0% +difference between that equation and +the advection equation that had a + + align:start position:0% +the advection equation that had a + + + align:start position:0% +the advection equation that had a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +velocity here we have a velocity + + align:start position:0% +velocity here we have a velocity + + + align:start position:0% +velocity here we have a velocity +that so C is minus U I + + align:start position:0% +that so C is minus U I + + + align:start position:0% +that so C is minus U I +guess C is minus think of C uh this U as + + align:start position:0% +guess C is minus think of C uh this U as + + + align:start position:0% +guess C is minus think of C uh this U as +being comparable to minus + + align:start position:0% +being comparable to minus + + + align:start position:0% +being comparable to minus +C so in other words If U is positive I'm + + align:start position:0% +C so in other words If U is positive I'm + + + align:start position:0% +C so in other words If U is positive I'm +now going to have waves going to the + + align:start position:0% +now going to have waves going to the + + + align:start position:0% +now going to have waves going to the +right so let me just put this down U + + align:start position:0% +right so let me just put this down U + + + align:start position:0% +right so let me just put this down U +greater than zero will mean + + align:start position:0% +greater than zero will mean + + + align:start position:0% +greater than zero will mean +waves going to increasing x to the + + align:start position:0% +waves going to increasing x to the + + + align:start position:0% +waves going to increasing x to the +right and the idea will be + + align:start position:0% +right and the idea will be + + + align:start position:0% +right and the idea will be +we have to discuss that + + align:start position:0% +we have to discuss that + + + align:start position:0% +we have to discuss that +problem and as always we would like to + + align:start position:0% +problem and as always we would like to + + + align:start position:0% +problem and as always we would like to +solve it uh analytically find some + + align:start position:0% +solve it uh analytically find some + + + align:start position:0% +solve it uh analytically find some +whatever formulas we + + align:start position:0% +whatever formulas we + + + align:start position:0% +whatever formulas we +can understand what's happening in terms + + align:start position:0% +can understand what's happening in terms + + + align:start position:0% +can understand what's happening in terms +of these characteristic lines because + + align:start position:0% +of these characteristic lines because + + + align:start position:0% +of these characteristic lines because +this when we have one equation and it's + + align:start position:0% +this when we have one equation and it's + + + align:start position:0% +this when we have one equation and it's +and uh one space variable we really + + align:start position:0% +and uh one space variable we really + + + align:start position:0% +and uh one space variable we really +can catch the the essence of the + + align:start position:0% +can catch the the essence of the + + + align:start position:0% +can catch the the essence of the +solution + + align:start position:0% +solution + + + align:start position:0% +solution +by understanding the characteristic + + align:start position:0% +by understanding the characteristic + + + align:start position:0% +by understanding the characteristic +lines and then how do we do it + + align:start position:0% +lines and then how do we do it + + + align:start position:0% +lines and then how do we do it +numerically okay so I before class I + + align:start position:0% +numerically okay so I before class I + + + align:start position:0% +numerically okay so I before class I +wrote just a few equivalent forms of it + + align:start position:0% +wrote just a few equivalent forms of it + + + align:start position:0% +wrote just a few equivalent forms of it +this is an equivalent form and this is + + align:start position:0% +this is an equivalent form and this is + + + align:start position:0% +this is an equivalent form and this is +so to speak the right + + align:start position:0% + + + + align:start position:0% + +form this is the form where we see a + + align:start position:0% +form this is the form where we see a + + + align:start position:0% +form this is the form where we see a +Time derivative of U as always + + align:start position:0% +Time derivative of U as always + + + align:start position:0% +Time derivative of U as always +and we see a space derivative of U ^2 + + align:start position:0% +and we see a space derivative of U ^2 + + + align:start position:0% +and we see a space derivative of U ^2 +over 2 which of course produces that but + + align:start position:0% +over 2 which of course produces that but + + + align:start position:0% +over 2 which of course produces that but +somehow this is the quantity it's called + + align:start position:0% +somehow this is the quantity it's called + + + align:start position:0% +somehow this is the quantity it's called +the + + align:start position:0% +the + + + align:start position:0% +the +flux that's uh physically + + align:start position:0% +flux that's uh physically + + + align:start position:0% +flux that's uh physically +meaningful F of U so I've chosen a + + align:start position:0% +meaningful F of U so I've chosen a + + + align:start position:0% +meaningful F of U so I've chosen a +simple flux function U ^2 over + + align:start position:0% + + + + align:start position:0% + +2 and uh so that's the difference + + align:start position:0% +2 and uh so that's the difference + + + align:start position:0% +2 and uh so that's the difference +equation + + align:start position:0% +equation + + + align:start position:0% +equation +but you'll see that the differential + + align:start position:0% +but you'll see that the differential + + + align:start position:0% +but you'll see that the differential +equation + + align:start position:0% +equation + + + align:start position:0% +equation +can produce a multi two solutions at the + + align:start position:0% +can produce a multi two solutions at the + + + align:start position:0% +can produce a multi two solutions at the +same point and we have to + + align:start position:0% +same point and we have to + + + align:start position:0% +same point and we have to +choose in other words the the + + align:start position:0% +choose in other words the the + + + align:start position:0% +choose in other words the the +differential the the solution can become + + align:start position:0% +differential the the solution can become + + + align:start position:0% +differential the the solution can become +discontinuous a perfectly + + align:start position:0% +discontinuous a perfectly + + + align:start position:0% +discontinuous a perfectly +smooth starting + + align:start position:0% +smooth starting + + + align:start position:0% +smooth starting +function after a while + + align:start position:0% +function after a while + + + align:start position:0% +function after a while +this is the essence of the of the + + align:start position:0% +this is the essence of the of the + + + align:start position:0% +this is the essence of the of the +problem + + align:start position:0% +problem + + + align:start position:0% +problem +now I have a I might have a smooth + + align:start position:0% +now I have a I might have a smooth + + + align:start position:0% +now I have a I might have a smooth +starting function at least + + align:start position:0% + + + + align:start position:0% + +continuous the solution is constant + + align:start position:0% +continuous the solution is constant + + + align:start position:0% +continuous the solution is constant +along characteristic + + align:start position:0% +along characteristic + + + align:start position:0% +along characteristic +lines but what happens if two + + align:start position:0% +lines but what happens if two + + + align:start position:0% +lines but what happens if two +characteristic lines run into each other + + align:start position:0% +characteristic lines run into each other + + + align:start position:0% +characteristic lines run into each other +I've drawn that possibility + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +and it'll take a little time to see + + align:start position:0% +and it'll take a little time to see + + + align:start position:0% +and it'll take a little time to see +exactly what's happening but the + + align:start position:0% +exactly what's happening but the + + + align:start position:0% +exactly what's happening but the +characteristics we can see here so the + + align:start position:0% +characteristics we can see here so the + + + align:start position:0% +characteristics we can see here so the +starting values were one up to that + + align:start position:0% + + + + align:start position:0% + +point so when the starting value is + + align:start position:0% +point so when the starting value is + + + align:start position:0% +point so when the starting value is +one and the and U is constant along + + align:start position:0% +one and the and U is constant along + + + align:start position:0% +one and the and U is constant along +characteristic lines then U is one and + + align:start position:0% +characteristic lines then U is one and + + + align:start position:0% +characteristic lines then U is one and +those lines it's just like having c + + align:start position:0% +those lines it's just like having c + + + align:start position:0% +those lines it's just like having c +equal to c equal to minus one I guess in + + align:start position:0% +equal to c equal to minus one I guess in + + + align:start position:0% +equal to c equal to minus one I guess in +the in the one-way wave equation we have + + align:start position:0% +the in the one-way wave equation we have + + + align:start position:0% +the in the one-way wave equation we have +a one-way wave going to the right now + + align:start position:0% +a one-way wave going to the right now + + + align:start position:0% +a one-way wave going to the right now +along characteristic lines so U is one + + align:start position:0% +along characteristic lines so U is one + + + align:start position:0% +along characteristic lines so U is one +in all this X in this part of the XT + + align:start position:0% + + + + align:start position:0% + +plane + + align:start position:0% +plane + + + align:start position:0% +plane +right we have to come back to the + + align:start position:0% +right we have to come back to the + + + align:start position:0% +right we have to come back to the +formulas to to confirm what I just said + + align:start position:0% +formulas to to confirm what I just said + + + align:start position:0% +formulas to to confirm what I just said +and then over here at the far + + align:start position:0% +and then over here at the far + + + align:start position:0% +and then over here at the far +right the starting value is + + align:start position:0% + + + + align:start position:0% + +zero and + + align:start position:0% +zero and + + + align:start position:0% +zero and +um + + align:start position:0% +um + + + align:start position:0% +um +the characteristics in that case the the + + align:start position:0% +the characteristics in that case the the + + + align:start position:0% +the characteristics in that case the the +velocity the C associated with that is + + align:start position:0% +velocity the C associated with that is + + + align:start position:0% +velocity the C associated with that is +zero so it's a standing it's not moving + + align:start position:0% +zero so it's a standing it's not moving + + + align:start position:0% +zero so it's a standing it's not moving +the characteristics are just straight + + align:start position:0% +the characteristics are just straight + + + align:start position:0% +the characteristics are just straight +lines in the time Direction nothing's + + align:start position:0% +lines in the time Direction nothing's + + + align:start position:0% +lines in the time Direction nothing's +happening right when you think of a + + align:start position:0% +happening right when you think of a + + + align:start position:0% +happening right when you think of a +characteristic that's going straight up + + align:start position:0% +characteristic that's going straight up + + + align:start position:0% +characteristic that's going straight up +it's just carrying in the value of U + + align:start position:0% +it's just carrying in the value of U + + + align:start position:0% +it's just carrying in the value of U +without moving left or right so you + + align:start position:0% +without moving left or right so you + + + align:start position:0% +without moving left or right so you +stays zero so youu is you will be one + + align:start position:0% +stays zero so youu is you will be one + + + align:start position:0% +stays zero so youu is you will be one +here you will be zero here and now + + align:start position:0% +here you will be zero here and now + + + align:start position:0% +here you will be zero here and now +something's happening in here and we + + align:start position:0% +something's happening in here and we + + + align:start position:0% +something's happening in here and we +have to figure out what it + + align:start position:0% +have to figure out what it + + + align:start position:0% +have to figure out what it +is but maybe I can anticipate the main + + align:start position:0% +is but maybe I can anticipate the main + + + align:start position:0% +is but maybe I can anticipate the main +point before any any + + align:start position:0% +point before any any + + + align:start position:0% +point before any any +algebra the the characteristic lines in + + align:start position:0% +algebra the the characteristic lines in + + + align:start position:0% +algebra the the characteristic lines in +the in this + + align:start position:0% +the in this + + + align:start position:0% +the in this +region have a slope somewhere between + + align:start position:0% +region have a slope somewhere between + + + align:start position:0% +region have a slope somewhere between +the slope + + align:start position:0% +the slope + + + align:start position:0% +the slope +one and the slope + + align:start position:0% +one and the slope + + + align:start position:0% +one and the slope +zero you see we're starting let me let + + align:start position:0% +zero you see we're starting let me let + + + align:start position:0% +zero you see we're starting let me let +me graph u z of X so so let me graph u u + + align:start position:0% +me graph u z of X so so let me graph u u + + + align:start position:0% +me graph u z of X so so let me graph u u +u of + + align:start position:0% +u of + + + align:start position:0% +u of +X + + align:start position:0% +X + + + align:start position:0% +X +is let me the key points are zero and + + align:start position:0% +is let me the key points are zero and + + + align:start position:0% +is let me the key points are zero and +one 0 and one so u z of + + align:start position:0% +one 0 and one so u z of + + + align:start position:0% +one 0 and one so u z of +X I start with + + align:start position:0% +X I start with + + + align:start position:0% +X I start with +a with a + + align:start position:0% + + + + align:start position:0% + +constant initial function the constant + + align:start position:0% +constant initial function the constant + + + align:start position:0% +constant initial function the constant +profile to the left of zero and a + + align:start position:0% +profile to the left of zero and a + + + align:start position:0% +profile to the left of zero and a +constant profile to the right of one and + + align:start position:0% +constant profile to the right of one and + + + align:start position:0% +constant profile to the right of one and +linear + + align:start position:0% +linear + + + align:start position:0% +linear +between okay so it's that it's that + + align:start position:0% +between okay so it's that it's that + + + align:start position:0% +between okay so it's that it's that +starting values that I wrote here 1 1 - + + align:start position:0% +starting values that I wrote here 1 1 - + + + align:start position:0% +starting values that I wrote here 1 1 - +x and Zer are these three + + align:start position:0% +x and Zer are these three + + + align:start position:0% +x and Zer are these three +pieces and then here I'm in the XT plane + + align:start position:0% +pieces and then here I'm in the XT plane + + + align:start position:0% +pieces and then here I'm in the XT plane +where here I'm in the XU plane + + align:start position:0% +where here I'm in the XU plane + + + align:start position:0% +where here I'm in the XU plane +so I drew characteristics and we still + + align:start position:0% +so I drew characteristics and we still + + + align:start position:0% +so I drew characteristics and we still +have to track we have to say more what + + align:start position:0% +have to track we have to say more what + + + align:start position:0% +have to track we have to say more what +characteristics are and understand that + + align:start position:0% +characteristics are and understand that + + + align:start position:0% +characteristics are and understand that +these have slopes in between but you're + + align:start position:0% +these have slopes in between but you're + + + align:start position:0% +these have slopes in between but you're +not surprised because the the values of + + align:start position:0% +not surprised because the the values of + + + align:start position:0% +not surprised because the the values of +you are in between one and zero so they + + align:start position:0% +you are in between one and zero so they + + + align:start position:0% +you are in between one and zero so they +go that way and they meet + + align:start position:0% +go that way and they meet + + + align:start position:0% +go that way and they meet +here so up to time t equal 1 + + align:start position:0% +here so up to time t equal 1 + + + align:start position:0% +here so up to time t equal 1 +characteristics tell everything up to t + + align:start position:0% +characteristics tell everything up to t + + + align:start position:0% +characteristics tell everything up to t +equal one I know that U will be one + + align:start position:0% +equal one I know that U will be one + + + align:start position:0% +equal one I know that U will be one +along these characteristics and when I + + align:start position:0% +along these characteristics and when I + + + align:start position:0% +along these characteristics and when I +find these characteristics U is whatever + + align:start position:0% +find these characteristics U is whatever + + + align:start position:0% +find these characteristics U is whatever +it starts at what and U is zero up all + + align:start position:0% +it starts at what and U is zero up all + + + align:start position:0% +it starts at what and U is zero up all +these characteristics so up to that + + align:start position:0% +these characteristics so up to that + + + align:start position:0% +these characteristics so up to that +time uh algebra the F the differential + + align:start position:0% +time uh algebra the F the differential + + + align:start position:0% +time uh algebra the F the differential +equation is going to be totally + + align:start position:0% +equation is going to be totally + + + align:start position:0% +equation is going to be totally +okay but after that time the + + align:start position:0% +okay but after that time the + + + align:start position:0% +okay but after that time the +differential equation is in difficulty + + align:start position:0% +differential equation is in difficulty + + + align:start position:0% +differential equation is in difficulty +because at that moment T so what's + + align:start position:0% +because at that moment T so what's + + + align:start position:0% +because at that moment T so what's +happening as t as T increases from 0 to + + align:start position:0% +happening as t as T increases from 0 to + + + align:start position:0% +happening as t as T increases from 0 to +one there this is the picture at t equal + + align:start position:0% +one there this is the picture at t equal + + + align:start position:0% +one there this is the picture at t equal +Z the picture at t equal to 1 at t equal + + align:start position:0% +Z the picture at t equal to 1 at t equal + + + align:start position:0% +Z the picture at t equal to 1 at t equal +a half let's say what would be the + + align:start position:0% +a half let's say what would be the + + + align:start position:0% +a half let's say what would be the +picture at t equal to half well this at + + align:start position:0% +picture at t equal to half well this at + + + align:start position:0% +picture at t equal to half well this at +t equal to half this state one has has + + align:start position:0% +t equal to half this state one has has + + + align:start position:0% +t equal to half this state one has has +penetrated this + + align:start position:0% +penetrated this + + + align:start position:0% +penetrated this +far half to to halfway + + align:start position:0% +far half to to halfway + + + align:start position:0% +far half to to halfway +then in here is this uh converging + + align:start position:0% +then in here is this uh converging + + + align:start position:0% +then in here is this uh converging +characteristics that come from a + + align:start position:0% +characteristics that come from a + + + align:start position:0% +characteristics that come from a +linear uh profile and over here it's all + + align:start position:0% +linear uh profile and over here it's all + + + align:start position:0% +linear uh profile and over here it's all +zeros so that zero is still there but + + align:start position:0% +zeros so that zero is still there but + + + align:start position:0% +zeros so that zero is still there but +the you see what's happening this guy is + + align:start position:0% +the you see what's happening this guy is + + + align:start position:0% +the you see what's happening this guy is +the profile is + + align:start position:0% +the profile is + + + align:start position:0% +the profile is +steepening this is at t equal to + + align:start position:0% + + + + align:start position:0% + +half steeper + + align:start position:0% + + + + align:start position:0% + +we still have the algebra to do but I + + align:start position:0% +we still have the algebra to do but I + + + align:start position:0% +we still have the algebra to do but I +think it's if you the main first thing + + align:start position:0% +think it's if you the main first thing + + + align:start position:0% +think it's if you the main first thing +is to see roughly what's happening then + + align:start position:0% +is to see roughly what's happening then + + + align:start position:0% +is to see roughly what's happening then +at t equal to + + align:start position:0% +at t equal to + + + align:start position:0% +at t equal to +one this is totally steep so this is the + + align:start position:0% +one this is totally steep so this is the + + + align:start position:0% +one this is totally steep so this is the +situation at tal to + + align:start position:0% +situation at tal to + + + align:start position:0% +situation at tal to +1 I have and I could have I could have + + align:start position:0% +1 I have and I could have I could have + + + align:start position:0% +1 I have and I could have I could have +given you that as the initial condition + + align:start position:0% +given you that as the initial condition + + + align:start position:0% +given you that as the initial condition +but I and the 16 920 notes thought okay + + align:start position:0% +but I and the 16 920 notes thought okay + + + align:start position:0% +but I and the 16 920 notes thought okay +let's have a little piece for a while + + align:start position:0% +let's have a little piece for a while + + + align:start position:0% +let's have a little piece for a while +see what those characteristics are doing + + align:start position:0% +see what those characteristics are doing + + + align:start position:0% +see what those characteristics are doing +when they're when they're uh they're + + align:start position:0% +when they're when they're uh they're + + + align:start position:0% +when they're when they're uh they're +converging but they're not + + align:start position:0% +converging but they're not + + + align:start position:0% +converging but they're not +crossing the trouble is after t equal to + + align:start position:0% +crossing the trouble is after t equal to + + + align:start position:0% +crossing the trouble is after t equal to +one they are + + align:start position:0% +one they are + + + align:start position:0% +one they are +crossing and + + align:start position:0% +crossing and + + + align:start position:0% +crossing and +now what's the solution in this re in + + align:start position:0% +now what's the solution in this re in + + + align:start position:0% +now what's the solution in this re in +this cross-hatched rain + + align:start position:0% +this cross-hatched rain + + + align:start position:0% +this cross-hatched rain +region do I follow do I take the value + + align:start position:0% +region do I follow do I take the value + + + align:start position:0% +region do I follow do I take the value +zero that's coming up along these + + align:start position:0% +zero that's coming up along these + + + align:start position:0% +zero that's coming up along these +characteristics do I take the value one + + align:start position:0% +characteristics do I take the value one + + + align:start position:0% +characteristics do I take the value one +that's coming along these + + align:start position:0% +that's coming along these + + + align:start position:0% +that's coming along these +characteristics what's happening in + + align:start position:0% +characteristics what's happening in + + + align:start position:0% +characteristics what's happening in +here so there's a cross-hatched region + + align:start position:0% +here so there's a cross-hatched region + + + align:start position:0% +here so there's a cross-hatched region +there which uh is a big question + + align:start position:0% + + + + align:start position:0% + +mark because my rule of following + + align:start position:0% +mark because my rule of following + + + align:start position:0% +mark because my rule of following +characteristics has led me to two + + align:start position:0% +characteristics has led me to two + + + align:start position:0% +characteristics has led me to two +answers + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +uh we want we want a physically relevant + + align:start position:0% +uh we want we want a physically relevant + + + align:start position:0% +uh we want we want a physically relevant +answer we want uh we're sort of + + align:start position:0% +answer we want uh we're sort of + + + align:start position:0% +answer we want uh we're sort of +expecting and we'll see that this uh + + align:start position:0% +expecting and we'll see that this uh + + + align:start position:0% +expecting and we'll see that this uh +that this um Step + + align:start position:0% + + + + align:start position:0% + +function is a step function I mean we + + align:start position:0% +function is a step function I mean we + + + align:start position:0% +function is a step function I mean we +the answer will be a step function it + + align:start position:0% +the answer will be a step function it + + + align:start position:0% +the answer will be a step function it +will be one and then drop to + + align:start position:0% +will be one and then drop to + + + align:start position:0% +will be one and then drop to +zero along + + align:start position:0% +zero along + + + align:start position:0% +zero along +some path in the XT plane which is not a + + align:start position:0% +some path in the XT plane which is not a + + + align:start position:0% +some path in the XT plane which is not a +characteristic the characteristics are + + align:start position:0% +characteristic the characteristics are + + + align:start position:0% +characteristic the characteristics are +going at + + align:start position:0% +going at + + + align:start position:0% +going at +45° and at + + align:start position:0% +45° and at + + + align:start position:0% +45° and at +90° and + + align:start position:0% +90° and + + + align:start position:0% +90° and +actually it's so this is the region I'm + + align:start position:0% +actually it's so this is the region I'm + + + align:start position:0% +actually it's so this is the region I'm +interested in so can I blow up that + + align:start position:0% +interested in so can I blow up that + + + align:start position:0% +interested in so can I blow up that +region so if I blow up that region which + + align:start position:0% +region so if I blow up that region which + + + align:start position:0% +region so if I blow up that region which +that's where the + + align:start position:0% +that's where the + + + align:start position:0% +that's where the +shocks the shocks are are meeting + + align:start position:0% +shocks the shocks are are meeting + + + align:start position:0% +shocks the shocks are are meeting +everywhere in this in this region this + + align:start position:0% +everywhere in this in this region this + + + align:start position:0% +everywhere in this in this region this +was the point what was that point that I + + align:start position:0% +was the point what was that point that I + + + align:start position:0% +was the point what was that point that I +guess that was the point xal 0 and t + + align:start position:0% +guess that was the point xal 0 and t + + + align:start position:0% +guess that was the point xal 0 and t +equal 1 there okay and the question is + + align:start position:0% +equal 1 there okay and the question is + + + align:start position:0% +equal 1 there okay and the question is +so and I know that I have U equal Z over + + align:start position:0% +so and I know that I have U equal Z over + + + align:start position:0% +so and I know that I have U equal Z over +here here and I know oops U equal 1 over + + align:start position:0% +here here and I know oops U equal 1 over + + + align:start position:0% +here here and I know oops U equal 1 over +here and I know that I have U equal 0 + + align:start position:0% +here and I know that I have U equal 0 + + + align:start position:0% +here and I know that I have U equal 0 +here but the question is where + + align:start position:0% +here but the question is where + + + align:start position:0% +here but the question is where +and well what happens in between + + align:start position:0% + + + + align:start position:0% + +you can think of at least two + + align:start position:0% +you can think of at least two + + + align:start position:0% +you can think of at least two +possible + + align:start position:0% + + + + align:start position:0% + +scenarios and one of those is that + + align:start position:0% +scenarios and one of those is that + + + align:start position:0% +scenarios and one of those is that +there's a shock + + align:start position:0% +there's a shock + + + align:start position:0% +there's a shock +line that goes let's say somewhere in + + align:start position:0% +line that goes let's say somewhere in + + + align:start position:0% +line that goes let's say somewhere in +the middle and so that you you stays one + + align:start position:0% +the middle and so that you you stays one + + + align:start position:0% +the middle and so that you you stays one +all the way to that line and drops to + + align:start position:0% +all the way to that line and drops to + + + align:start position:0% +all the way to that line and drops to +zero after it in other words this this + + align:start position:0% +zero after it in other words this this + + + align:start position:0% +zero after it in other words this this +um wall of + + align:start position:0% +um wall of + + + align:start position:0% +um wall of +water travels to the + + align:start position:0% +water travels to the + + + align:start position:0% +water travels to the +right the the shock the discontinuity + + align:start position:0% +right the the shock the discontinuity + + + align:start position:0% +right the the shock the discontinuity +moves + + align:start position:0% +moves + + + align:start position:0% +moves +along uh not necessarily at the speed + + align:start position:0% +along uh not necessarily at the speed + + + align:start position:0% +along uh not necessarily at the speed +that this one this this would be moving + + align:start position:0% +that this one this this would be moving + + + align:start position:0% +that this one this this would be moving +along the speed of one with this + + align:start position:0% +along the speed of one with this + + + align:start position:0% +along the speed of one with this +pushing not stationary either which is + + align:start position:0% +pushing not stationary either which is + + + align:start position:0% +pushing not stationary either which is +what this the right side would like but + + align:start position:0% +what this the right side would like but + + + align:start position:0% +what this the right side would like but +somewhere between so that's a shock line + + align:start position:0% +somewhere between so that's a shock line + + + align:start position:0% +somewhere between so that's a shock line +I just for short call it a + + align:start position:0% +I just for short call it a + + + align:start position:0% +I just for short call it a +shock + + align:start position:0% +shock + + + align:start position:0% +shock +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay then there's another possibility + + align:start position:0% +okay then there's another possibility + + + align:start position:0% +okay then there's another possibility +and that will happen in this case + + align:start position:0% +and that will happen in this case + + + align:start position:0% +and that will happen in this case +actually that will happen in this + + align:start position:0% +actually that will happen in this + + + align:start position:0% +actually that will happen in this +case but there is another possibility + + align:start position:0% +case but there is another possibility + + + align:start position:0% +case but there is another possibility +that will happen in other + + align:start position:0% +that will happen in other + + + align:start position:0% +that will happen in other +cases and that would be a + + align:start position:0% +cases and that would be a + + + align:start position:0% +cases and that would be a +fan of + + align:start position:0% +fan of + + + align:start position:0% +fan of +characteristics let let me see that when + + align:start position:0% +characteristics let let me see that when + + + align:start position:0% +characteristics let let me see that when +it comes but I I'm just mentioning it to + + align:start position:0% +it comes but I I'm just mentioning it to + + + align:start position:0% +it comes but I I'm just mentioning it to +say that this business of the shock line + + align:start position:0% +say that this business of the shock line + + + align:start position:0% +say that this business of the shock line +which is what we'll pursue now which + + align:start position:0% +which is what we'll pursue now which + + + align:start position:0% +which is what we'll pursue now which +because it's what happens with this + + align:start position:0% +because it's what happens with this + + + align:start position:0% +because it's what happens with this +problem is not the + + align:start position:0% +problem is not the + + + align:start position:0% +problem is not the +only is not always the the uh the way to + + align:start position:0% +only is not always the the uh the way to + + + align:start position:0% +only is not always the the uh the way to +the way to match the way to deal with a + + align:start position:0% +the way to match the way to deal with a + + + align:start position:0% +the way to match the way to deal with a +a a problem of of lack of information + + align:start position:0% +a a problem of of lack of information + + + align:start position:0% +a a problem of of lack of information +coming from the characteristics okay so + + align:start position:0% +coming from the characteristics okay so + + + align:start position:0% +coming from the characteristics okay so +so I guess our question + + align:start position:0% +so I guess our question + + + align:start position:0% +so I guess our question +is what is that shock line what's the + + align:start position:0% +is what is that shock line what's the + + + align:start position:0% +is what is that shock line what's the +path what's the + + align:start position:0% +path what's the + + + align:start position:0% +path what's the +slope and what what controls it and the + + align:start position:0% +slope and what what controls it and the + + + align:start position:0% +slope and what what controls it and the +answer will be the what control the + + align:start position:0% +answer will be the what control the + + + align:start position:0% +answer will be the what control the +we've run into problems with the + + align:start position:0% +we've run into problems with the + + + align:start position:0% +we've run into problems with the +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equation and the way + + align:start position:0% +equation and the way + + + align:start position:0% +equation and the way +to see + + align:start position:0% +to see + + + align:start position:0% +to see +what continues to happen + + align:start position:0% +what continues to happen + + + align:start position:0% +what continues to happen +is to go to the integrated form the + + align:start position:0% +is to go to the integrated form the + + + align:start position:0% +is to go to the integrated form the +integral form of the equation where of + + align:start position:0% +integral form of the equation where of + + + align:start position:0% +integral form of the equation where of +course by taking an integral I've made + + align:start position:0% +course by taking an integral I've made + + + align:start position:0% +course by taking an integral I've made +it I make everything smoother and also I + + align:start position:0% +it I make everything smoother and also I + + + align:start position:0% +it I make everything smoother and also I +preserve the physical law the + + align:start position:0% +preserve the physical law the + + + align:start position:0% +preserve the physical law the +conservation law so this is really the + + align:start position:0% +conservation law so this is really the + + + align:start position:0% +conservation law so this is really the +conservation + + align:start position:0% +conservation + + + align:start position:0% +conservation +law it's conser what is this well let's + + align:start position:0% +law it's conser what is this well let's + + + align:start position:0% +law it's conser what is this well let's +first of all see where it comes from it + + align:start position:0% +first of all see where it comes from it + + + align:start position:0% +first of all see where it comes from it +just comes from + + align:start position:0% +just comes from + + + align:start position:0% +just comes from +integrating this + + align:start position:0% +integrating this + + + align:start position:0% +integrating this +equation with respect to X so I have a + + align:start position:0% +equation with respect to X so I have a + + + align:start position:0% +equation with respect to X so I have a +Time derivative that I keep out here and + + align:start position:0% +Time derivative that I keep out here and + + + align:start position:0% +Time derivative that I keep out here and +but my space derivative is going to + + align:start position:0% +but my space derivative is going to + + + align:start position:0% +but my space derivative is going to +disappear because I'm integrating with + + align:start position:0% +disappear because I'm integrating with + + + align:start position:0% +disappear because I'm integrating with +respect to X so I can call D by DT or + + align:start position:0% +respect to X so I can call D by DT or + + + align:start position:0% +respect to X so I can call D by DT or +partial d by DT the integral of U with + + align:start position:0% +partial d by DT the integral of U with + + + align:start position:0% +partial d by DT the integral of U with +respect to X and I'm integrating from + + align:start position:0% +respect to X and I'm integrating from + + + align:start position:0% +respect to X and I'm integrating from +somewhere from some point to some other + + align:start position:0% +somewhere from some point to some other + + + align:start position:0% +somewhere from some point to some other +point instead of A and B I'll call them + + align:start position:0% +point instead of A and B I'll call them + + + align:start position:0% +point instead of A and B I'll call them +uh + + align:start position:0% +uh + + + align:start position:0% +uh +I really I'm sorry I should say X on the + + align:start position:0% +I really I'm sorry I should say X on the + + + align:start position:0% +I really I'm sorry I should say X on the +left and X on the + + align:start position:0% +left and X on the + + + align:start position:0% +left and X on the +right some point x at the left and some + + align:start position:0% +right some point x at the left and some + + + align:start position:0% +right some point x at the left and some +point x at the + + align:start position:0% +point x at the + + + align:start position:0% +point x at the +right and now I've integrated this one + + align:start position:0% +right and now I've integrated this one + + + align:start position:0% +right and now I've integrated this one +I've I've called This is f of U so I'm + + align:start position:0% +I've I've called This is f of U so I'm + + + align:start position:0% +I've I've called This is f of U so I'm +now thinking of any uh flux + + align:start position:0% +now thinking of any uh flux + + + align:start position:0% +now thinking of any uh flux +function and the integral of course + + align:start position:0% +function and the integral of course + + + align:start position:0% +function and the integral of course +gives me f of U at the upper end minus F + + align:start position:0% +gives me f of U at the upper end minus F + + + align:start position:0% +gives me f of U at the upper end minus F +of U at the lower end okay so that's the + + align:start position:0% +of U at the lower end okay so that's the + + + align:start position:0% +of U at the lower end okay so that's the +conservation law let me write that word + + align:start position:0% +conservation law let me write that word + + + align:start position:0% +conservation law let me write that word +down this is the conservation law what + + align:start position:0% +down this is the conservation law what + + + align:start position:0% +down this is the conservation law what +is it + + align:start position:0% + + + + align:start position:0% + +saying it's saying that the change in + + align:start position:0% +saying it's saying that the change in + + + align:start position:0% +saying it's saying that the change in +the + + align:start position:0% +the + + + align:start position:0% +the +quantity in the + + align:start position:0% +quantity in the + + + align:start position:0% +quantity in the +interval is given by if there's any + + align:start position:0% +interval is given by if there's any + + + align:start position:0% +interval is given by if there's any +change any any time derivative the rate + + align:start position:0% +change any any time derivative the rate + + + align:start position:0% +change any any time derivative the rate +of change in the interval + + align:start position:0% +of change in the interval + + + align:start position:0% +of change in the interval +of this of this it's a conservation of + + align:start position:0% +of this of this it's a conservation of + + + align:start position:0% +of this of this it's a conservation of +this + + align:start position:0% +this + + + align:start position:0% +this +integral meaning that the that any + + align:start position:0% +integral meaning that the that any + + + align:start position:0% +integral meaning that the that any +change in that integral happens + + align:start position:0% +change in that integral happens + + + align:start position:0% +change in that integral happens +because there's flow going out the right + + align:start position:0% +because there's flow going out the right + + + align:start position:0% +because there's flow going out the right +hand side of the interval or there's + + align:start position:0% +hand side of the interval or there's + + + align:start position:0% +hand side of the interval or there's +flow coming in the left side of the + + align:start position:0% +flow coming in the left side of the + + + align:start position:0% +flow coming in the left side of the +interval so that's why we have a minus + + align:start position:0% +interval so that's why we have a minus + + + align:start position:0% +interval so that's why we have a minus +sign between them so that's a statement + + align:start position:0% +sign between them so that's a statement + + + align:start position:0% +sign between them so that's a statement +of + + align:start position:0% +of + + + align:start position:0% +of +conservation and uh oh there's one more + + align:start position:0% +conservation and uh oh there's one more + + + align:start position:0% +conservation and uh oh there's one more +example that I I'll mention now so let + + align:start position:0% +example that I I'll mention now so let + + + align:start position:0% +example that I I'll mention now so let +me give this a particular equation a + + align:start position:0% +me give this a particular equation a + + + align:start position:0% +me give this a particular equation a +name just because you see it you often + + align:start position:0% +name just because you see it you often + + + align:start position:0% +name just because you see it you often +see it written uh called Burger's + + align:start position:0% + + + + align:start position:0% + +equation but + + align:start position:0% +equation but + + + align:start position:0% +equation but +actually the the full name is the inv + + align:start position:0% +actually the the full name is the inv + + + align:start position:0% +actually the the full name is the inv +visive no + + align:start position:0% + + + + align:start position:0% + +viscosity Berger's equation because it's + + align:start position:0% +viscosity Berger's equation because it's + + + align:start position:0% +viscosity Berger's equation because it's +a + + align:start position:0% + + + + align:start position:0% + +zero so just one word about Burger's + + align:start position:0% +zero so just one word about Burger's + + + align:start position:0% +zero so just one word about Burger's +equation so + + align:start position:0% +equation so + + + align:start position:0% +equation so +Burger allowed a uxx term here so he had + + align:start position:0% +Burger allowed a uxx term here so he had + + + align:start position:0% +Burger allowed a uxx term here so he had +uh one of our conve nonlinear + + align:start position:0% +uh one of our conve nonlinear + + + align:start position:0% +uh one of our conve nonlinear +convection and a diffusion + + align:start position:0% +convection and a diffusion + + + align:start position:0% +convection and a diffusion +term and his convection was was this + + align:start position:0% +term and his convection was was this + + + align:start position:0% +term and his convection was was this +simple uh expression + + align:start position:0% +simple uh expression + + + align:start position:0% +simple uh expression +uux it's the kind of thing you see in + + align:start position:0% +uux it's the kind of thing you see in + + + align:start position:0% +uux it's the kind of thing you see in +the nav Stokes equations right the + + align:start position:0% +the nav Stokes equations right the + + + align:start position:0% +the nav Stokes equations right the +nonlinearity in NV stes is sort of in + + align:start position:0% +nonlinearity in NV stes is sort of in + + + align:start position:0% +nonlinearity in NV stes is sort of in +this term of this General sort but this + + align:start position:0% +this term of this General sort but this + + + align:start position:0% +this term of this General sort but this +is + + align:start position:0% +is + + + align:start position:0% +is +a major simplification such a + + align:start position:0% +a major simplification such a + + + align:start position:0% +a major simplification such a +simplification that + + align:start position:0% +simplification that + + + align:start position:0% +simplification that +Burgers could solve even though the + + align:start position:0% +Burgers could solve even though the + + + align:start position:0% +Burgers could solve even though the +equation was + + align:start position:0% + + + + align:start position:0% + +nonlinear uh well two people at the same + + align:start position:0% +nonlinear uh well two people at the same + + + align:start position:0% +nonlinear uh well two people at the same +time discovered the change of variable + + align:start position:0% +time discovered the change of variable + + + align:start position:0% +time discovered the change of variable +simple little + + align:start position:0% +simple little + + + align:start position:0% +simple little +trick hop and Cole I'll put their names + + align:start position:0% +trick hop and Cole I'll put their names + + + align:start position:0% +trick hop and Cole I'll put their names +down because they had nice short last + + align:start position:0% +down because they had nice short last + + + align:start position:0% +down because they had nice short last +names they both discovered uh in the + + align:start position:0% +names they both discovered uh in the + + + align:start position:0% +names they both discovered uh in the +case of a diffusion term they both + + align:start position:0% +case of a diffusion term they both + + + align:start position:0% +case of a diffusion term they both +discovered a little a change of + + align:start position:0% +discovered a little a change of + + + align:start position:0% +discovered a little a change of +variables that made the equation linear + + align:start position:0% +variables that made the equation linear + + + align:start position:0% +variables that made the equation linear +then they could solve the equation + + align:start position:0% +then they could solve the equation + + + align:start position:0% +then they could solve the equation +that's in the textbook uh in this + + align:start position:0% +that's in the textbook uh in this + + + align:start position:0% +that's in the textbook uh in this +section on conservation laws and then + + align:start position:0% +section on conservation laws and then + + + align:start position:0% +section on conservation laws and then +what then the important thing what the + + align:start position:0% +what then the important thing what the + + + align:start position:0% +what then the important thing what the +burgers could do was let the diffusion + + align:start position:0% +burgers could do was let the diffusion + + + align:start position:0% +burgers could do was let the diffusion +coefficient go to zero so then in the + + align:start position:0% +coefficient go to zero so then in the + + + align:start position:0% +coefficient go to zero so then in the +limit he got the invit burgers equation + + align:start position:0% +limit he got the invit burgers equation + + + align:start position:0% +limit he got the invit burgers equation +the one we're looking at and he could + + align:start position:0% +the one we're looking at and he could + + + align:start position:0% +the one we're looking at and he could +look at the solution and let the limit + + align:start position:0% +look at the solution and let the limit + + + align:start position:0% +look at the solution and let the limit +go to zero + + align:start position:0% +go to zero + + + align:start position:0% +go to zero +and that's another way to figure out + + align:start position:0% +and that's another way to figure out + + + align:start position:0% +and that's another way to figure out +what's the right + + align:start position:0% +what's the right + + + align:start position:0% +what's the right +Solution that's the viscosity method a + + align:start position:0% +Solution that's the viscosity method a + + + align:start position:0% +Solution that's the viscosity method a +fundamental method for finding out when + + align:start position:0% +fundamental method for finding out when + + + align:start position:0% +fundamental method for finding out when +when we run into a problem shocks run + + align:start position:0% +when we run into a problem shocks run + + + align:start position:0% +when we run into a problem shocks run +into each other we don't know which it + + align:start position:0% +into each other we don't know which it + + + align:start position:0% +into each other we don't know which it +what the which what to + + align:start position:0% +what the which what to + + + align:start position:0% +what the which what to +choose one way to find out in in this 1D + + align:start position:0% +choose one way to find out in in this 1D + + + align:start position:0% +choose one way to find out in in this 1D +problem and also in much tougher + + align:start position:0% +problem and also in much tougher + + + align:start position:0% +problem and also in much tougher +nonlinear multi-dimensional problems is + + align:start position:0% +nonlinear multi-dimensional problems is + + + align:start position:0% +nonlinear multi-dimensional problems is +put in a little viscosity + + align:start position:0% +put in a little viscosity + + + align:start position:0% +put in a little viscosity +and and let it be small let it even get + + align:start position:0% +and and let it be small let it even get + + + align:start position:0% +and and let it be small let it even get +smaller then with a little + + align:start position:0% +smaller then with a little + + + align:start position:0% +smaller then with a little +viscosity officially this + + align:start position:0% +viscosity officially this + + + align:start position:0% +viscosity officially this +term in some sense the the the uh this + + align:start position:0% +term in some sense the the the uh this + + + align:start position:0% +term in some sense the the the uh this +term because it's a second derivative is + + align:start position:0% +term because it's a second derivative is + + + align:start position:0% +term because it's a second derivative is +officially mathematically speaking sort + + align:start position:0% +officially mathematically speaking sort + + + align:start position:0% +officially mathematically speaking sort +of dominates this + + align:start position:0% + + + + align:start position:0% + +one as far as I mean this will get + + align:start position:0% +one as far as I mean this will get + + + align:start position:0% +one as far as I mean this will get +produce a smooth solution + + align:start position:0% + + + + align:start position:0% + +soltion this term as we know doesn't + + align:start position:0% +soltion this term as we know doesn't + + + align:start position:0% +soltion this term as we know doesn't +smooth the solution just just advs it + + align:start position:0% +smooth the solution just just advs it + + + align:start position:0% +smooth the solution just just advs it +just carries it along but this term will + + align:start position:0% +just carries it along but this term will + + + align:start position:0% +just carries it along but this term will +smooth it so th this is uh the the + + align:start position:0% +smooth it so th this is uh the the + + + align:start position:0% +smooth it so th this is uh the the +dominant term the second derivative no + + align:start position:0% +dominant term the second derivative no + + + align:start position:0% +dominant term the second derivative no +surprise uh + + align:start position:0% +surprise uh + + + align:start position:0% +surprise uh +but so when we introduce that that + + align:start position:0% +but so when we introduce that that + + + align:start position:0% +but so when we introduce that that +Smooths everything we get it we have no + + align:start position:0% +Smooths everything we get it we have no + + + align:start position:0% +Smooths everything we get it we have no +problem to say there is a illusion for + + align:start position:0% +problem to say there is a illusion for + + + align:start position:0% +problem to say there is a illusion for +at least for simpler + + align:start position:0% +at least for simpler + + + align:start position:0% +at least for simpler +models and uh then we can see what + + align:start position:0% +models and uh then we can see what + + + align:start position:0% +models and uh then we can see what +happens when that when that term + + align:start position:0% +happens when that when that term + + + align:start position:0% +happens when that when that term +approaches zero okay so that's another + + align:start position:0% +approaches zero okay so that's another + + + align:start position:0% +approaches zero okay so that's another +method and of course that's kind of what + + align:start position:0% +method and of course that's kind of what + + + align:start position:0% +method and of course that's kind of what +we're doing with finite differences + + align:start position:0% +we're doing with finite differences + + + align:start position:0% +we're doing with finite differences +finite differences if we put in a little + + align:start position:0% +finite differences if we put in a little + + + align:start position:0% +finite differences if we put in a little +viscosity a little second space + + align:start position:0% +viscosity a little second space + + + align:start position:0% +viscosity a little second space +difference and take delta T small enough + + align:start position:0% +difference and take delta T small enough + + + align:start position:0% +difference and take delta T small enough +for stability then we can solve + + align:start position:0% +for stability then we can solve + + + align:start position:0% +for stability then we can solve +it and if we take it very + + align:start position:0% +it and if we take it very + + + align:start position:0% +it and if we take it very +small we should get something close to + + align:start position:0% +small we should get something close to + + + align:start position:0% +small we should get something close to +the invis Limit okay so that's uh that I + + align:start position:0% +the invis Limit okay so that's uh that I + + + align:start position:0% +the invis Limit okay so that's uh that I +was just giving Burger's name to that + + align:start position:0% +was just giving Burger's name to that + + + align:start position:0% +was just giving Burger's name to that +particular example so this isn't the + + align:start position:0% +particular example so this isn't the + + + align:start position:0% +particular example so this isn't the +only example but it's the simplest + + align:start position:0% +only example but it's the simplest + + + align:start position:0% +only example but it's the simplest +example okay another + + align:start position:0% +example okay another + + + align:start position:0% +example okay another +example of conservation laws that + + align:start position:0% +example of conservation laws that + + + align:start position:0% +example of conservation laws that +everybody likes I think + + align:start position:0% +everybody likes I think + + + align:start position:0% +everybody likes I think +is the traffic flow traffic flow in One + + align:start position:0% +is the traffic flow traffic flow in One + + + align:start position:0% +is the traffic flow traffic flow in One +Direction say on the Mass Pike so what's + + align:start position:0% +Direction say on the Mass Pike so what's + + + align:start position:0% +Direction say on the Mass Pike so what's +the equation of traffic flow can I put + + align:start position:0% +the equation of traffic flow can I put + + + align:start position:0% +the equation of traffic flow can I put +that let me put that on a board here and + + align:start position:0% +that let me put that on a board here and + + + align:start position:0% +that let me put that on a board here and +then uh then I have to come back to + + align:start position:0% +then uh then I have to come back to + + + align:start position:0% +then uh then I have to come back to +this okay well I'll put it + + align:start position:0% +this okay well I'll put it + + + align:start position:0% +this okay well I'll put it +here so example two well I don't know if + + align:start position:0% +here so example two well I don't know if + + + align:start position:0% +here so example two well I don't know if +you can call that example one we didn't + + align:start position:0% +you can call that example one we didn't + + + align:start position:0% +you can call that example one we didn't +give it a physical meaning example two + + align:start position:0% +give it a physical meaning example two + + + align:start position:0% +give it a physical meaning example two +will be traffic flow + + align:start position:0% + + + + align:start position:0% + +flow in + + align:start position:0% +flow in + + + align:start position:0% +flow in +1D and what's the + + align:start position:0% + + + + align:start position:0% + +unknown well it's the thing I've been + + align:start position:0% +unknown well it's the thing I've been + + + align:start position:0% +unknown well it's the thing I've been +calling + + align:start position:0% +calling + + + align:start position:0% +calling +you + + align:start position:0% +you + + + align:start position:0% +you +but uh for traffic flow the natural + + align:start position:0% +but uh for traffic flow the natural + + + align:start position:0% +but uh for traffic flow the natural +unknown is the density of the traffic + + align:start position:0% +unknown is the density of the traffic + + + align:start position:0% +unknown is the density of the traffic +the density of the cars is the car + + align:start position:0% +the density of the cars is the car + + + align:start position:0% +the density of the cars is the car +density + + align:start position:0% + + + + align:start position:0% + +and everybody calls uses Row for density + + align:start position:0% +and everybody calls uses Row for density + + + align:start position:0% +and everybody calls uses Row for density +so can I use row rather than + + align:start position:0% + + + + align:start position:0% + +U and then in the uh in the equation + + align:start position:0% +U and then in the uh in the equation + + + align:start position:0% +U and then in the uh in the equation +will + + align:start position:0% +will + + + align:start position:0% +will +be uh a a a car a velocity that I'll + + align:start position:0% +be uh a a a car a velocity that I'll + + + align:start position:0% +be uh a a a car a velocity that I'll +call + + align:start position:0% + + + + align:start position:0% + +V that's not a new + + align:start position:0% + + + + align:start position:0% + +unknown in fact in fact the velocity + + align:start position:0% +unknown in fact in fact the velocity + + + align:start position:0% +unknown in fact in fact the velocity +experimentally depends or the there's a + + align:start position:0% +experimentally depends or the there's a + + + align:start position:0% +experimentally depends or the there's a +relation the density and the velocity + + align:start position:0% +relation the density and the velocity + + + align:start position:0% +relation the density and the velocity +are by experiments if you run an + + align:start position:0% +are by experiments if you run an + + + align:start position:0% +are by experiments if you run an +experiment on the Mass Pike in heavy + + align:start position:0% +experiment on the Mass Pike in heavy + + + align:start position:0% +experiment on the Mass Pike in heavy +traffic that could be a homework problem + + align:start position:0% +traffic that could be a homework problem + + + align:start position:0% +traffic that could be a homework problem +too to uh find the relation between uh V + + align:start position:0% +too to uh find the relation between uh V + + + align:start position:0% +too to uh find the relation between uh V +and row so I'm going to keep this row as + + align:start position:0% +and row so I'm going to keep this row as + + + align:start position:0% +and row so I'm going to keep this row as +the unknown and imagine that we have + + align:start position:0% +the unknown and imagine that we have + + + align:start position:0% +the unknown and imagine that we have +some experimental velocity V of row and + + align:start position:0% +some experimental velocity V of row and + + + align:start position:0% +some experimental velocity V of row and +and what would we expect I guess we + + align:start position:0% +and what would we expect I guess we + + + align:start position:0% +and what would we expect I guess we +expect that uh as + + align:start position:0% +expect that uh as + + + align:start position:0% +expect that uh as +row uh increase as the density increases + + align:start position:0% +row uh increase as the density increases + + + align:start position:0% +row uh increase as the density increases +what will + + align:start position:0% +what will + + + align:start position:0% +what will +happen as the density + + align:start position:0% +happen as the density + + + align:start position:0% +happen as the density +increases the traffic is going to slow + + align:start position:0% +increases the traffic is going to slow + + + align:start position:0% +increases the traffic is going to slow +down ultimately come to a + + align:start position:0% +down ultimately come to a + + + align:start position:0% +down ultimately come to a +stop where if the density is ex is is + + align:start position:0% +stop where if the density is ex is is + + + align:start position:0% +stop where if the density is ex is is +very small so the the density is zero I + + align:start position:0% +very small so the the density is zero I + + + align:start position:0% +very small so the the density is zero I +we just have a single + + align:start position:0% +we just have a single + + + align:start position:0% +we just have a single +driver the police are not out so he's + + align:start position:0% +driver the police are not out so he's + + + align:start position:0% +driver the police are not out so he's +going you know + + align:start position:0% +going you know + + + align:start position:0% +going you know +Vmax or 2 + + align:start position:0% + + + + align:start position:0% + +Vmax but uh as the as the the uh Road + + align:start position:0% +Vmax but uh as the as the the uh Road + + + align:start position:0% +Vmax but uh as the as the the uh Road +gets crowded the velocity drops and + + align:start position:0% +gets crowded the velocity drops and + + + align:start position:0% +gets crowded the velocity drops and +maybe drops linearly + + align:start position:0% + + + + align:start position:0% + +that would be a possible and not not not + + align:start position:0% +that would be a possible and not not not + + + align:start position:0% +that would be a possible and not not not +that terrible + + align:start position:0% +that terrible + + + align:start position:0% +that terrible +uh + + align:start position:0% + + + + align:start position:0% + +uh relation between V and row so what + + align:start position:0% +uh relation between V and row so what + + + align:start position:0% +uh relation between V and row so what +would be the flux function in this + + align:start position:0% +would be the flux function in this + + + align:start position:0% +would be the flux function in this +traffic flow + + align:start position:0% +traffic flow + + + align:start position:0% +traffic flow +problem the conservation law is like + + align:start position:0% +problem the conservation law is like + + + align:start position:0% +problem the conservation law is like +conservation of cars right if we look at + + align:start position:0% +conservation of cars right if we look at + + + align:start position:0% +conservation of cars right if we look at +um a unit you know a certain uh a piece + + align:start position:0% +um a unit you know a certain uh a piece + + + align:start position:0% +um a unit you know a certain uh a piece +of the + + align:start position:0% +of the + + + align:start position:0% +of the +turnpike then the conservation law says + + align:start position:0% +turnpike then the conservation law says + + + align:start position:0% +turnpike then the conservation law says +that the total number of cars + + align:start position:0% +that the total number of cars + + + align:start position:0% +that the total number of cars +inside CH which is this + + align:start position:0% +inside CH which is this + + + align:start position:0% +inside CH which is this +changes by cars + + align:start position:0% +changes by cars + + + align:start position:0% +changes by cars +leaving and by cars + + align:start position:0% +leaving and by cars + + + align:start position:0% +leaving and by cars +entering and so the flux function I + + align:start position:0% +entering and so the flux function I + + + align:start position:0% +entering and so the flux function I +think will be so we have to know like + + align:start position:0% +think will be so we have to know like + + + align:start position:0% +think will be so we have to know like +sort how many cars are + + align:start position:0% +sort how many cars are + + + align:start position:0% +sort how many cars are +leaving and I think the flux function + + align:start position:0% +leaving and I think the flux function + + + align:start position:0% +leaving and I think the flux function +would be probably V * row I think the + + align:start position:0% +would be probably V * row I think the + + + align:start position:0% +would be probably V * row I think the +flux function flux function of row now + + align:start position:0% +flux function flux function of row now + + + align:start position:0% +flux function flux function of row now +is my + + align:start position:0% + + + + align:start position:0% + +unknown I think would be V of row times + + align:start position:0% +unknown I think would be V of row times + + + align:start position:0% +unknown I think would be V of row times +Row the velocity times the density + + align:start position:0% +Row the velocity times the density + + + align:start position:0% +Row the velocity times the density +that's tell me tells me how many cars + + align:start position:0% +that's tell me tells me how many cars + + + align:start position:0% +that's tell me tells me how many cars +are going out okay so I guess what I + + align:start position:0% +are going out okay so I guess what I + + + align:start position:0% +are going out okay so I guess what I +want to say is that we will meet that we + + align:start position:0% +want to say is that we will meet that we + + + align:start position:0% +want to say is that we will meet that we +we we meet in this traffic flow example + + align:start position:0% +we we meet in this traffic flow example + + + align:start position:0% +we we meet in this traffic flow example +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +these + + align:start position:0% +these + + + align:start position:0% +these +possibilities + + align:start position:0% +possibilities + + + align:start position:0% +possibilities +that we meet them mathematically just + + align:start position:0% +that we meet them mathematically just + + + align:start position:0% +that we meet them mathematically just +the way we meet them in actual + + align:start position:0% +the way we meet them in actual + + + align:start position:0% +the way we meet them in actual +driving + + align:start position:0% +driving + + + align:start position:0% +driving +of + + align:start position:0% +of + + + align:start position:0% +of +uh a shock so this this shock + + align:start position:0% +uh a shock so this this shock + + + align:start position:0% +uh a shock so this this shock +corresponds to so what's that like stop + + align:start position:0% + + + + align:start position:0% + +go this corresponds to I suppose like + + align:start position:0% +go this corresponds to I suppose like + + + align:start position:0% +go this corresponds to I suppose like +meeting a red + + align:start position:0% + + + + align:start position:0% + +light coming up to a red light the + + align:start position:0% +light coming up to a red light the + + + align:start position:0% +light coming up to a red light the +traffic you know behind normally stops + + align:start position:0% +traffic you know behind normally stops + + + align:start position:0% +traffic you know behind normally stops +has to come has to slow way down and + + align:start position:0% +has to come has to slow way down and + + + align:start position:0% +has to come has to slow way down and +stop then the light turns + + align:start position:0% +stop then the light turns + + + align:start position:0% +stop then the light turns +green the first car takes off the cars + + align:start position:0% +green the first car takes off the cars + + + align:start position:0% +green the first car takes off the cars +begin to spread + + align:start position:0% +begin to spread + + + align:start position:0% +begin to spread +out that's + + align:start position:0% +out that's + + + align:start position:0% +out that's +the + + align:start position:0% +the + + + align:start position:0% +the +uh the solution that I that I have that + + align:start position:0% +uh the solution that I that I have that + + + align:start position:0% +uh the solution that I that I have that +I don't see in this with this uh + + align:start position:0% +I don't see in this with this uh + + + align:start position:0% +I don't see in this with this uh +starting function a a sort of fan of + + align:start position:0% +starting function a a sort of fan of + + + align:start position:0% +starting function a a sort of fan of +cars so so maybe I could write those + + align:start position:0% +cars so so maybe I could write those + + + align:start position:0% +cars so so maybe I could write those +words down shock or a + + align:start position:0% + + + + align:start position:0% + +fan this is the shock is is what happens + + align:start position:0% +fan this is the shock is is what happens + + + align:start position:0% +fan this is the shock is is what happens +when characteristics come together cars + + align:start position:0% +when characteristics come together cars + + + align:start position:0% +when characteristics come together cars +come together the fan is when the + + align:start position:0% +come together the fan is when the + + + align:start position:0% +come together the fan is when the +characteristics fan out + + align:start position:0% +characteristics fan out + + + align:start position:0% +characteristics fan out +actually I could I could illustrate a + + align:start position:0% +actually I could I could illustrate a + + + align:start position:0% +actually I could I could illustrate a +fan here right away suppose I reverse 0 + + align:start position:0% +fan here right away suppose I reverse 0 + + + align:start position:0% +fan here right away suppose I reverse 0 +and + + align:start position:0% + + + + align:start position:0% + +one just to see what okay so here's my + + align:start position:0% +one just to see what okay so here's my + + + align:start position:0% +one just to see what okay so here's my +this is my X + + align:start position:0% +this is my X + + + align:start position:0% +this is my X +again so here I'm going to I'm going to + + align:start position:0% +again so here I'm going to I'm going to + + + align:start position:0% +again so here I'm going to I'm going to +have u0 to be Z + + align:start position:0% +have u0 to be Z + + + align:start position:0% +have u0 to be Z +now u0 to + + align:start position:0% +now u0 to + + + align:start position:0% +now u0 to +be well I I can even it's called a remon + + align:start position:0% +be well I I can even it's called a remon + + + align:start position:0% +be well I I can even it's called a remon +problem when there are just two values + + align:start position:0% +problem when there are just two values + + + align:start position:0% +problem when there are just two values +here U is one so + + align:start position:0% +here U is one so + + + align:start position:0% +here U is one so +I'm so that the so-called remon problem + + align:start position:0% +I'm so that the so-called remon problem + + + align:start position:0% +I'm so that the so-called remon problem +is the cleanest example of the whole of + + align:start position:0% +is the cleanest example of the whole of + + + align:start position:0% +is the cleanest example of the whole of +the whole conservation law theory when + + align:start position:0% +the whole conservation law theory when + + + align:start position:0% +the whole conservation law theory when +there are just two starting values zero + + align:start position:0% +there are just two starting values zero + + + align:start position:0% +there are just two starting values zero +and one or one and zero and it makes a + + align:start position:0% +and one or one and zero and it makes a + + + align:start position:0% +and one or one and zero and it makes a +big difference one and zero we saw when + + align:start position:0% +big difference one and zero we saw when + + + align:start position:0% +big difference one and zero we saw when +we reach time one we had a one and a + + align:start position:0% +we reach time one we had a one and a + + + align:start position:0% +we reach time one we had a one and a +zero and after that a shock form here + + align:start position:0% +zero and after that a shock form here + + + align:start position:0% +zero and after that a shock form here +zero and one the characteristics here + + align:start position:0% +zero and one the characteristics here + + + align:start position:0% +zero and one the characteristics here +are going as always so U is one + + align:start position:0% +are going as always so U is one + + + align:start position:0% +are going as always so U is one +here characteristics + + align:start position:0% +here characteristics + + + align:start position:0% +here characteristics +here this is staying at zero there's no + + align:start position:0% +here this is staying at zero there's no + + + align:start position:0% +here this is staying at zero there's no +reason to change but here we + + align:start position:0% +reason to change but here we + + + align:start position:0% +reason to change but here we +have + + align:start position:0% +have + + + align:start position:0% +have +now a region just like the other one but + + align:start position:0% +now a region just like the other one but + + + align:start position:0% +now a region just like the other one but +with a major difference that now it's u + + align:start position:0% +with a major difference that now it's u + + + align:start position:0% +with a major difference that now it's u +z on the left and one on the right where + + align:start position:0% +z on the left and one on the right where + + + align:start position:0% +z on the left and one on the right where +before it was one on the left and zero + + align:start position:0% +before it was one on the left and zero + + + align:start position:0% +before it was one on the left and zero +on the right and the question is what + + align:start position:0% +on the right and the question is what + + + align:start position:0% +on the right and the question is what +happens in here well you might think a + + align:start position:0% +happens in here well you might think a + + + align:start position:0% +happens in here well you might think a +shock an a a a a step up from zero to + + align:start position:0% +shock an a a a a step up from zero to + + + align:start position:0% +shock an a a a a step up from zero to +one at some point + + align:start position:0% +one at some point + + + align:start position:0% +one at some point +and I would have to agree that you could + + align:start position:0% +and I would have to agree that you could + + + align:start position:0% +and I would have to agree that you could +do that in such a way that you maintain + + align:start position:0% +do that in such a way that you maintain + + + align:start position:0% +do that in such a way that you maintain +the conservation law + + align:start position:0% + + + + align:start position:0% + +but that's not what + + align:start position:0% +but that's not what + + + align:start position:0% +but that's not what +happens this is this is going to be a + + align:start position:0% +happens this is this is going to be a + + + align:start position:0% +happens this is this is going to be a +fan in + + align:start position:0% + + + + align:start position:0% + +here we're going to have we what we'll + + align:start position:0% +here we're going to have we what we'll + + + align:start position:0% +here we're going to have we what we'll +have as characteristics in here this + + align:start position:0% +have as characteristics in here this + + + align:start position:0% +have as characteristics in here this +will let me draw the profile so the + + align:start position:0% +will let me draw the profile so the + + + align:start position:0% +will let me draw the profile so the +profile is zero there to + + align:start position:0% +profile is zero there to + + + align:start position:0% +profile is zero there to +zero and and at some time then over + + align:start position:0% +zero and and at some time then over + + + align:start position:0% +zero and and at some time then over +here where this characteristic is met + + align:start position:0% +here where this characteristic is met + + + align:start position:0% +here where this characteristic is met +it's one and this is what + + align:start position:0% +it's one and this is what + + + align:start position:0% +it's one and this is what +happens + + align:start position:0% + + + + align:start position:0% + +the in instead of getting worse less + + align:start position:0% +the in instead of getting worse less + + + align:start position:0% +the in instead of getting worse less +smooth the solution gets better more + + align:start position:0% +smooth the solution gets better more + + + align:start position:0% +smooth the solution gets better more +smooth when it when the directions is + + align:start position:0% +smooth when it when the directions is + + + align:start position:0% +smooth when it when the directions is +reversed so we see that our problem had + + align:start position:0% +reversed so we see that our problem had + + + align:start position:0% +reversed so we see that our problem had +to be nonlinear a linear problem + + align:start position:0% +to be nonlinear a linear problem + + + align:start position:0% +to be nonlinear a linear problem +couldn't do these two opposite things + + align:start position:0% +couldn't do these two opposite things + + + align:start position:0% +couldn't do these two opposite things +in uh the same thing so here we would + + align:start position:0% +in uh the same thing so here we would + + + align:start position:0% +in uh the same thing so here we would +have a fan and that the characteristics + + align:start position:0% +have a fan and that the characteristics + + + align:start position:0% +have a fan and that the characteristics +go there and it's reflected there okay + + align:start position:0% +go there and it's reflected there okay + + + align:start position:0% +go there and it's reflected there okay +so there's a picture of the phenomena + + align:start position:0% +so there's a picture of the phenomena + + + align:start position:0% +so there's a picture of the phenomena +that we're looking at and would and we + + align:start position:0% +that we're looking at and would and we + + + align:start position:0% +that we're looking at and would and we +would like to see numerically + + align:start position:0% +would like to see numerically + + + align:start position:0% +would like to see numerically +too when I so next + + align:start position:0% +too when I so next + + + align:start position:0% +too when I so next +time I want to + + align:start position:0% +time I want to + + + align:start position:0% +time I want to +find so I can say now what I have to do + + align:start position:0% +find so I can say now what I have to do + + + align:start position:0% +find so I can say now what I have to do +next time one is to to locate the + + align:start position:0% +next time one is to to locate the + + + align:start position:0% +next time one is to to locate the +shock the shock line when there is one + + align:start position:0% +shock the shock line when there is one + + + align:start position:0% +shock the shock line when there is one +and two to + + align:start position:0% +and two to + + + align:start position:0% +and two to +decide how do we decide between shock or + + align:start position:0% +decide how do we decide between shock or + + + align:start position:0% +decide how do we decide between shock or +fan + + align:start position:0% + + + + align:start position:0% + +when when from the point of view of pure + + align:start position:0% +when when from the point of view of pure + + + align:start position:0% +when when from the point of view of pure +conservation we could + + align:start position:0% +conservation we could + + + align:start position:0% +conservation we could +choose but nature makes a choice and one + + align:start position:0% +choose but nature makes a choice and one + + + align:start position:0% +choose but nature makes a choice and one +way to decide make that decision is + + align:start position:0% +way to decide make that decision is + + + align:start position:0% +way to decide make that decision is +Burger's way of putting in a little + + align:start position:0% +Burger's way of putting in a little + + + align:start position:0% +Burger's way of putting in a little +diffusion and letting it get zero go to + + align:start position:0% +diffusion and letting it get zero go to + + + align:start position:0% +diffusion and letting it get zero go to +disappear but we need a direct rule so + + align:start position:0% +disappear but we need a direct rule so + + + align:start position:0% +disappear but we need a direct rule so +we need a direct entropy condition so + + align:start position:0% +we need a direct entropy condition so + + + align:start position:0% +we need a direct entropy condition so +this is going to be uh uh a uh shock + + align:start position:0% +this is going to be uh uh a uh shock + + + align:start position:0% +this is going to be uh uh a uh shock +speed a formula for shock speed s s + + align:start position:0% +speed a formula for shock speed s s + + + align:start position:0% +speed a formula for shock speed s s +equals shock speed we'll + + align:start position:0% +equals shock speed we'll + + + align:start position:0% +equals shock speed we'll +find if there is a shock and number two + + align:start position:0% +find if there is a shock and number two + + + align:start position:0% +find if there is a shock and number two +is going to be this decision is going to + + align:start position:0% +is going to be this decision is going to + + + align:start position:0% +is going to be this decision is going to +be based on a quantity called entropy + + align:start position:0% + + + + align:start position:0% + +which appears only in nonlinear problems + + align:start position:0% +which appears only in nonlinear problems + + + align:start position:0% +which appears only in nonlinear problems +really okay so that's uh that's a + + align:start position:0% +really okay so that's uh that's a + + + align:start position:0% +really okay so that's uh that's a +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +picture which uh these + + align:start position:0% +picture which uh these + + + align:start position:0% +picture which uh these +uh 16920 + + align:start position:0% +uh 16920 + + + align:start position:0% +uh 16920 +notes are a excellent reference for the + + align:start position:0% +notes are a excellent reference for the + + + align:start position:0% +notes are a excellent reference for the +book also and uh Monday's lecture will + + align:start position:0% +book also and uh Monday's lecture will + + + align:start position:0% +book also and uh Monday's lecture will +pick up there so we we can see the two + + align:start position:0% +pick up there so we we can see the two + + + align:start position:0% +pick up there so we we can see the two +the two situations here + + align:start position:0% +the two situations here + + + align:start position:0% +the two situations here +and the question is what do we do at + + align:start position:0% +and the question is what do we do at + + + align:start position:0% +and the question is what do we do at +this point okay see you Monday have a + + align:start position:0% +this point okay see you Monday have a + + + align:start position:0% +this point okay see you Monday have a +good weekend and uh any uh email + + align:start position:0% +good weekend and uh any uh email + + + align:start position:0% +good weekend and uh any uh email +questions about the homework just you + + align:start position:0% +questions about the homework just you + + + align:start position:0% +questions about the homework just you +could send to me or to Andor to maybe + + align:start position:0% +could send to me or to Andor to maybe + + + align:start position:0% +could send to me or to Andor to maybe +and to Mr Cho who will be looking at the + + align:start position:0% +and to Mr Cho who will be looking at the + + + align:start position:0% +and to Mr Cho who will be looking at the +homeworks that come + + align:start position:0% +homeworks that come + + + align:start position:0% +homeworks that come +in good thanks \ No newline at end of file diff --git a/FuGcyIynuxg.txt b/FuGcyIynuxg.txt new file mode 100644 index 0000000000000000000000000000000000000000..3d3bc26ebec3367e77ff048aa75de37be2609721 --- /dev/null +++ b/FuGcyIynuxg.txt @@ -0,0 +1,12019 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +well while people are filing in we can + + align:start position:0% +well while people are filing in we can + + + align:start position:0% +well while people are filing in we can +chat a little bit about the quiz overall + + align:start position:0% +chat a little bit about the quiz overall + + + align:start position:0% +chat a little bit about the quiz overall +I was very very impressed at least with + + align:start position:0% +I was very very impressed at least with + + + align:start position:0% +I was very very impressed at least with +the question one in question to which I + + align:start position:0% +the question one in question to which I + + + align:start position:0% +the question one in question to which I +graded heathen grade in question three + + align:start position:0% +graded heathen grade in question three + + + align:start position:0% +graded heathen grade in question three +so here's all the all the statistics you + + align:start position:0% +so here's all the all the statistics you + + + align:start position:0% +so here's all the all the statistics you +can see that this was a pretty difficult + + align:start position:0% +can see that this was a pretty difficult + + + align:start position:0% +can see that this was a pretty difficult +quiz actually would you agree you have + + align:start position:0% +quiz actually would you agree you have + + + align:start position:0% +quiz actually would you agree you have +evidence to overcome that null + + align:start position:0% +evidence to overcome that null + + + align:start position:0% +evidence to overcome that null +hypothesis that it was a a difficult + + align:start position:0% +hypothesis that it was a a difficult + + + align:start position:0% +hypothesis that it was a a difficult +quiz you know so the average there about + + align:start position:0% +quiz you know so the average there about + + + align:start position:0% +quiz you know so the average there about +78 79 with a fairly fairly widespread + + align:start position:0% +78 79 with a fairly fairly widespread + + + align:start position:0% +78 79 with a fairly fairly widespread +what we will do is post both the quiz + + align:start position:0% +what we will do is post both the quiz + + + align:start position:0% +what we will do is post both the quiz +and the solutions which may be more + + align:start position:0% +and the solutions which may be more + + + align:start position:0% +and the solutions which may be more +interesting to you since you already + + align:start position:0% +interesting to you since you already + + + align:start position:0% +interesting to you since you already +have the quiz and if you do if you do + + align:start position:0% +have the quiz and if you do if you do + + + align:start position:0% +have the quiz and if you do if you do +see anything feel free to chat with us + + align:start position:0% +see anything feel free to chat with us + + + align:start position:0% +see anything feel free to chat with us +about about the question or whatever I + + align:start position:0% +about about the question or whatever I + + + align:start position:0% +about about the question or whatever I +if you're concerned about a point here + + align:start position:0% +if you're concerned about a point here + + + align:start position:0% +if you're concerned about a point here +or a point there I really wouldn't worry + + align:start position:0% +or a point there I really wouldn't worry + + + align:start position:0% +or a point there I really wouldn't worry +about it + + align:start position:0% +about it + + + align:start position:0% +about it +you know where our grading is is we + + align:start position:0% +you know where our grading is is we + + + align:start position:0% +you know where our grading is is we +attempt to be as accurate as possible + + align:start position:0% +attempt to be as accurate as possible + + + align:start position:0% +attempt to be as accurate as possible +but we reserve the right to have a + + align:start position:0% +but we reserve the right to have a + + + align:start position:0% +but we reserve the right to have a +little bit of variation given the nature + + align:start position:0% +little bit of variation given the nature + + + align:start position:0% +little bit of variation given the nature +of the course and in integrating and we + + align:start position:0% +of the course and in integrating and we + + + align:start position:0% +of the course and in integrating and we +will of course be treating everything a + + align:start position:0% +will of course be treating everything a + + + align:start position:0% +will of course be treating everything a +little bit as a mix in you know at the + + align:start position:0% +little bit as a mix in you know at the + + + align:start position:0% +little bit as a mix in you know at the +end from this quiz grade the second quiz + + align:start position:0% +end from this quiz grade the second quiz + + + align:start position:0% +end from this quiz grade the second quiz +grade class participation homeworks all + + align:start position:0% +grade class participation homeworks all + + + align:start position:0% +grade class participation homeworks all +of that so I I think the main thing to + + align:start position:0% +of that so I I think the main thing to + + + align:start position:0% +of that so I I think the main thing to +do is look at the solutions and make + + align:start position:0% +do is look at the solutions and make + + + align:start position:0% +do is look at the solutions and make +sure that you understand at least the + + align:start position:0% +sure that you understand at least the + + + align:start position:0% +sure that you understand at least the +approaches that we took in the solutions + + align:start position:0% +approaches that we took in the solutions + + + align:start position:0% +approaches that we took in the solutions +is not to say that some of the + + align:start position:0% +is not to say that some of the + + + align:start position:0% +is not to say that some of the +approaches that people took on the quiz + + align:start position:0% +approaches that people took on the quiz + + + align:start position:0% +approaches that people took on the quiz +is wrong + + align:start position:0% +is wrong + + + align:start position:0% +is wrong +in fact on problem - I think the biggest + + align:start position:0% +in fact on problem - I think the biggest + + + align:start position:0% +in fact on problem - I think the biggest +thing that we observed is people + + align:start position:0% +thing that we observed is people + + + align:start position:0% +thing that we observed is people +answered the third part if you remember + + align:start position:0% +answered the third part if you remember + + + align:start position:0% +answered the third part if you remember +really the hard way and unfortunately + + align:start position:0% +really the hard way and unfortunately + + + align:start position:0% +really the hard way and unfortunately +you may have burned a fair amount of + + align:start position:0% +you may have burned a fair amount of + + + align:start position:0% +you may have burned a fair amount of +time + + align:start position:0% +time + + + align:start position:0% +time +on that with very detailed t-tests and + + align:start position:0% +on that with very detailed t-tests and + + + align:start position:0% +on that with very detailed t-tests and +Neph tests and you know sort of + + align:start position:0% +Neph tests and you know sort of + + + align:start position:0% +Neph tests and you know sort of +complicated hypothesis tests whereas + + align:start position:0% +complicated hypothesis tests whereas + + + align:start position:0% +complicated hypothesis tests whereas +what you had was already the confidence + + align:start position:0% +what you had was already the confidence + + + align:start position:0% +what you had was already the confidence +intervals from Parts A and B that you + + align:start position:0% +intervals from Parts A and B that you + + + align:start position:0% +intervals from Parts A and B that you +could use directly in many cases to make + + align:start position:0% +could use directly in many cases to make + + + align:start position:0% +could use directly in many cases to make +inferences so were there any questions + + align:start position:0% +inferences so were there any questions + + + align:start position:0% +inferences so were there any questions +on the quiz top level not not detailed + + align:start position:0% +on the quiz top level not not detailed + + + align:start position:0% +on the quiz top level not not detailed +okay well take a look at those and again + + align:start position:0% +okay well take a look at those and again + + + align:start position:0% +okay well take a look at those and again +talk to Hayden arrive if more if you + + align:start position:0% +talk to Hayden arrive if more if you + + + align:start position:0% +talk to Hayden arrive if more if you +have any confusions I think is is the + + align:start position:0% +have any confusions I think is is the + + + align:start position:0% +have any confusions I think is is the +main thing okay so here's the plan for + + align:start position:0% +main thing okay so here's the plan for + + + align:start position:0% +main thing okay so here's the plan for +today we started on full factorial + + align:start position:0% +today we started on full factorial + + + align:start position:0% +today we started on full factorial +models design of experiments last time + + align:start position:0% +models design of experiments last time + + + align:start position:0% +models design of experiments last time +I'm gonna pick up where we left off on + + align:start position:0% +I'm gonna pick up where we left off on + + + align:start position:0% +I'm gonna pick up where we left off on +some of that talk a little bit more + + align:start position:0% +some of that talk a little bit more + + + align:start position:0% +some of that talk a little bit more +about the extension of that to + + align:start position:0% +about the extension of that to + + + align:start position:0% +about the extension of that to +generalize to decay experiments the key + + align:start position:0% +generalize to decay experiments the key + + + align:start position:0% +generalize to decay experiments the key +idea here is again picking out + + align:start position:0% +idea here is again picking out + + + align:start position:0% +idea here is again picking out +experimental design points so that you + + align:start position:0% +experimental design points so that you + + + align:start position:0% +experimental design points so that you +can fit particular kinds of models and + + align:start position:0% +can fit particular kinds of models and + + + align:start position:0% +can fit particular kinds of models and +we'll start again with ANOVA for linear + + align:start position:0% +we'll start again with ANOVA for linear + + + align:start position:0% +we'll start again with ANOVA for linear +models and then move on to asking the + + align:start position:0% +models and then move on to asking the + + + align:start position:0% +models and then move on to asking the +question what if a linear model is not + + align:start position:0% +question what if a linear model is not + + + align:start position:0% +question what if a linear model is not +sufficient how do you know if a linear + + align:start position:0% +sufficient how do you know if a linear + + + align:start position:0% +sufficient how do you know if a linear +model is not sufficient how do you check + + align:start position:0% +model is not sufficient how do you check + + + align:start position:0% +model is not sufficient how do you check +for the adequacy of the model form is + + align:start position:0% +for the adequacy of the model form is + + + align:start position:0% +for the adequacy of the model form is +there evidence that you need higher + + align:start position:0% +there evidence that you need higher + + + align:start position:0% +there evidence that you need higher +order terms like a quadratic or other + + align:start position:0% +order terms like a quadratic or other + + + align:start position:0% +order terms like a quadratic or other +curvature so we'll spend the first half + + align:start position:0% +curvature so we'll spend the first half + + + align:start position:0% +curvature so we'll spend the first half +really focused on that and then we'll + + align:start position:0% +really focused on that and then we'll + + + align:start position:0% +really focused on that and then we'll +start moving into some additional issues + + align:start position:0% +start moving into some additional issues + + + align:start position:0% +start moving into some additional issues +in experimental design these ideas of + + align:start position:0% +in experimental design these ideas of + + + align:start position:0% +in experimental design these ideas of +blocks and confounding as well as those + + align:start position:0% +blocks and confounding as well as those + + + align:start position:0% +blocks and confounding as well as those +same issues come out very strongly in + + align:start position:0% +same issues come out very strongly in + + + align:start position:0% +same issues come out very strongly in +fractional factorial designs so we'll + + align:start position:0% +fractional factorial designs so we'll + + + align:start position:0% +fractional factorial designs so we'll +get to that + + align:start position:0% +get to that + + + align:start position:0% +get to that +now I posted on the website reading + + align:start position:0% +now I posted on the website reading + + + align:start position:0% +now I posted on the website reading +assignment the key is probably + + align:start position:0% +assignment the key is probably + + + align:start position:0% +assignment the key is probably +Montgomery Chapter 12 I find that a + + align:start position:0% +Montgomery Chapter 12 I find that a + + + align:start position:0% +Montgomery Chapter 12 I find that a +little bit better description than then + + align:start position:0% +little bit better description than then + + + align:start position:0% +little bit better description than then +may and Spanos but there are some + + align:start position:0% +may and Spanos but there are some + + + align:start position:0% +may and Spanos but there are some +additional topics at the end of the main + + align:start position:0% +additional topics at the end of the main + + + align:start position:0% +additional topics at the end of the main +Spanos chapter that is 713 can't + + align:start position:0% +Spanos chapter that is 713 can't + + + align:start position:0% +Spanos chapter that is 713 can't +remember but it's it's posted on the + + align:start position:0% +remember but it's it's posted on the + + + align:start position:0% +remember but it's it's posted on the +website and so there are some things + + align:start position:0% +website and so there are some things + + + align:start position:0% +website and so there are some things +you'll want to scan and they in Spanish + + align:start position:0% +you'll want to scan and they in Spanish + + + align:start position:0% +you'll want to scan and they in Spanish +as well + + align:start position:0% +as well + + + align:start position:0% +as well +so recall that last time we started + + align:start position:0% +so recall that last time we started + + + align:start position:0% +so recall that last time we started +talking a little bit about the kinds of + + align:start position:0% +talking a little bit about the kinds of + + + align:start position:0% +talking a little bit about the kinds of +models that are associated with + + align:start position:0% +models that are associated with + + + align:start position:0% +models that are associated with +different experimental designs so for + + align:start position:0% +different experimental designs so for + + + align:start position:0% +different experimental designs so for +example we start with sort of this + + align:start position:0% +example we start with sort of this + + + align:start position:0% +example we start with sort of this +simple model it's not the simplest + + align:start position:0% +simple model it's not the simplest + + + align:start position:0% +simple model it's not the simplest +because we already have two factors but + + align:start position:0% +because we already have two factors but + + + align:start position:0% +because we already have two factors but +a very simple two by two or two to the + + align:start position:0% +a very simple two by two or two to the + + + align:start position:0% +a very simple two by two or two to the +two model where again what we've got are + + align:start position:0% +two model where again what we've got are + + + align:start position:0% +two model where again what we've got are +two levels in each of two factors so our + + align:start position:0% +two levels in each of two factors so our + + + align:start position:0% +two levels in each of two factors so our +factors here are X 1 and X 2 and we've + + align:start position:0% +factors here are X 1 and X 2 and we've + + + align:start position:0% +factors here are X 1 and X 2 and we've +got two different levels so we're just + + align:start position:0% +got two different levels so we're just + + + align:start position:0% +got two different levels so we're just +picking the corner points or extremal + + align:start position:0% +picking the corner points or extremal + + + align:start position:0% +picking the corner points or extremal +points for that and we talked last time + + align:start position:0% +points for that and we talked last time + + + align:start position:0% +points for that and we talked last time +about how this can generate a regression + + align:start position:0% +about how this can generate a regression + + + align:start position:0% +about how this can generate a regression +model that has both mean and first order + + align:start position:0% +model that has both mean and first order + + + align:start position:0% +model that has both mean and first order +terms as well as an interaction term we + + align:start position:0% +terms as well as an interaction term we + + + align:start position:0% +terms as well as an interaction term we +also talked about the way that you can + + align:start position:0% +also talked about the way that you can + + + align:start position:0% +also talked about the way that you can +estimate these using contrast and I'm + + align:start position:0% +estimate these using contrast and I'm + + + align:start position:0% +estimate these using contrast and I'm +going to pick up on that a little bit + + align:start position:0% +going to pick up on that a little bit + + + align:start position:0% +going to pick up on that a little bit +where we talk about the effect of + + align:start position:0% +where we talk about the effect of + + + align:start position:0% +where we talk about the effect of +varying x1 the total effect being a + + align:start position:0% +varying x1 the total effect being a + + + align:start position:0% +varying x1 the total effect being a +movement or in the output or an average + + align:start position:0% +movement or in the output or an average + + + align:start position:0% +movement or in the output or an average +movement in the output by a magnitude a + + align:start position:0% +movement in the output by a magnitude a + + + align:start position:0% +movement in the output by a magnitude a +in these coded coefficients for X 1 as + + align:start position:0% +in these coded coefficients for X 1 as + + + align:start position:0% +in these coded coefficients for X 1 as +well as effects for B and the + + align:start position:0% +well as effects for B and the + + + align:start position:0% +well as effects for B and the +interaction effect and basically we're + + align:start position:0% +interaction effect and basically we're + + + align:start position:0% +interaction effect and basically we're +seeing that there is this correspondence + + align:start position:0% +seeing that there is this correspondence + + + align:start position:0% +seeing that there is this correspondence +between a regression approach or a + + align:start position:0% +between a regression approach or a + + + align:start position:0% +between a regression approach or a +contrast approach is a very fast quick + + align:start position:0% +contrast approach is a very fast quick + + + align:start position:0% +contrast approach is a very fast quick +way to estimate these coefficients using + + align:start position:0% +way to estimate these coefficients using + + + align:start position:0% +way to estimate these coefficients using +these these kinds of design of + + align:start position:0% +these these kinds of design of + + + align:start position:0% +these these kinds of design of +experiments + + align:start position:0% + + + + align:start position:0% + +okay that's not good + + align:start position:0% + + + + align:start position:0% + +that's very strange all right so a + + align:start position:0% +that's very strange all right so a + + + align:start position:0% +that's very strange all right so a +little bit of the terminology that we we + + align:start position:0% +little bit of the terminology that we we + + + align:start position:0% +little bit of the terminology that we we +talked about just to remind us and then + + align:start position:0% +talked about just to remind us and then + + + align:start position:0% +talked about just to remind us and then +expand on that a little bit there is + + align:start position:0% +expand on that a little bit there is + + + align:start position:0% +expand on that a little bit there is +this notion of a contrast that's going + + align:start position:0% +this notion of a contrast that's going + + + align:start position:0% +this notion of a contrast that's going +to get us to being able to estimate the + + align:start position:0% +to get us to being able to estimate the + + + align:start position:0% +to get us to being able to estimate the +effect of say coefficient coefficient a + + align:start position:0% +effect of say coefficient coefficient a + + + align:start position:0% +effect of say coefficient coefficient a +or beta 1 or beta each of our two main + + align:start position:0% +or beta 1 or beta each of our two main + + + align:start position:0% +or beta 1 or beta each of our two main +effects or the interaction effects and + + align:start position:0% +effects or the interaction effects and + + + align:start position:0% +effects or the interaction effects and +these sort of condensed down tables + + align:start position:0% +these sort of condensed down tables + + + align:start position:0% +these sort of condensed down tables +summarizing the design of your + + align:start position:0% +summarizing the design of your + + + align:start position:0% +summarizing the design of your +experiment a really useful tools for + + align:start position:0% +experiment a really useful tools for + + + align:start position:0% +experiment a really useful tools for +being able to generate these contrasts + + align:start position:0% +being able to generate these contrasts + + + align:start position:0% +being able to generate these contrasts +for being able to identify what the mix + + align:start position:0% +for being able to identify what the mix + + + align:start position:0% +for being able to identify what the mix +of level settings are for each of the + + align:start position:0% +of level settings are for each of the + + + align:start position:0% +of level settings are for each of the +trial runs that we do and so on so a + + align:start position:0% +trial runs that we do and so on so a + + + align:start position:0% +trial runs that we do and so on so a +little bit of terminology again we said + + align:start position:0% +little bit of terminology again we said + + + align:start position:0% +little bit of terminology again we said +this column here the trial column is + + align:start position:0% +this column here the trial column is + + + align:start position:0% +this column here the trial column is +essentially you know our run and we can + + align:start position:0% +essentially you know our run and we can + + + align:start position:0% +essentially you know our run and we can +label them in a shorthand that tells us + + align:start position:0% +label them in a shorthand that tells us + + + align:start position:0% +label them in a shorthand that tells us +what our factor settings are our level + + align:start position:0% +what our factor settings are our level + + + align:start position:0% +what our factor settings are our level +settings are for each of our two factors + + align:start position:0% +settings are for each of our two factors + + + align:start position:0% +settings are for each of our two factors +are X 1 factor and our X 2 factor so the + + align:start position:0% +are X 1 factor and our X 2 factor so the + + + align:start position:0% +are X 1 factor and our X 2 factor so the +first label here is just the low setting + + align:start position:0% +first label here is just the low setting + + + align:start position:0% +first label here is just the low setting +for both of our factors and we'll label + + align:start position:0% +for both of our factors and we'll label + + + align:start position:0% +for both of our factors and we'll label +that with a with a 1 hour high setting + + align:start position:0% +that with a with a 1 hour high setting + + + align:start position:0% +that with a with a 1 hour high setting +for the a factor we label that one with + + align:start position:0% +for the a factor we label that one with + + + align:start position:0% +for the a factor we label that one with +a high setting or A+ sometimes well + + align:start position:0% +a high setting or A+ sometimes well + + + align:start position:0% +a high setting or A+ sometimes well +legal that is a +1 and our low setting + + align:start position:0% +legal that is a +1 and our low setting + + + align:start position:0% +legal that is a +1 and our low setting +then for everything else for B or B + + align:start position:0% +then for everything else for B or B + + + align:start position:0% +then for everything else for B or B +factor here that's where we set that one + + align:start position:0% +factor here that's where we set that one + + + align:start position:0% +factor here that's where we set that one +high and when we set both of them high + + align:start position:0% +high and when we set both of them high + + + align:start position:0% +high and when we set both of them high +that's our our plus setting for the two + + align:start position:0% +that's our our plus setting for the two + + + align:start position:0% +that's our our plus setting for the two +of them now we can also think about what + + align:start position:0% +of them now we can also think about what + + + align:start position:0% +of them now we can also think about what +is the sort of factor level for the + + align:start position:0% +is the sort of factor level for the + + + align:start position:0% +is the sort of factor level for the +interaction and we do that with this + + align:start position:0% +interaction and we do that with this + + + align:start position:0% +interaction and we do that with this +very funky shorthand algebra just saying + + align:start position:0% +very funky shorthand algebra just saying + + + align:start position:0% +very funky shorthand algebra just saying +okay a B is really think of that as a + + align:start position:0% +okay a B is really think of that as a + + + align:start position:0% +okay a B is really think of that as a +multiplication of the a and B factors so + + align:start position:0% +multiplication of the a and B factors so + + + align:start position:0% +multiplication of the a and B factors so +a minus 1 and a minus 1 gives a plus 1 + + align:start position:0% +a minus 1 and a minus 1 gives a plus 1 + + + align:start position:0% +a minus 1 and a minus 1 gives a plus 1 +there and similarly for all of the other + + align:start position:0% +there and similarly for all of the other + + + align:start position:0% +there and similarly for all of the other +columns that generates the level setting + + align:start position:0% +columns that generates the level setting + + + align:start position:0% +columns that generates the level setting +if you will for each of those + + align:start position:0% +if you will for each of those + + + align:start position:0% +if you will for each of those +for each of those combinations now in + + align:start position:0% +for each of those combinations now in + + + align:start position:0% +for each of those combinations now in +the actual experiment of course we're + + align:start position:0% +the actual experiment of course we're + + + align:start position:0% +the actual experiment of course we're +only setting X 1 and X 2 for each of our + + align:start position:0% +only setting X 1 and X 2 for each of our + + + align:start position:0% +only setting X 1 and X 2 for each of our +trials these experimental interaction + + align:start position:0% +trials these experimental interaction + + + align:start position:0% +trials these experimental interaction +columns are essentially giving us + + align:start position:0% +columns are essentially giving us + + + align:start position:0% +columns are essentially giving us +information that we need in order to + + align:start position:0% +information that we need in order to + + + align:start position:0% +information that we need in order to +form the contrast in the shorthand way + + align:start position:0% +form the contrast in the shorthand way + + + align:start position:0% +form the contrast in the shorthand way +of estimating effects as well as we'll + + align:start position:0% +of estimating effects as well as we'll + + + align:start position:0% +of estimating effects as well as we'll +see this a little bit later as well as + + align:start position:0% +see this a little bit later as well as + + + align:start position:0% +see this a little bit later as well as +telling us what the interaction term + + align:start position:0% +telling us what the interaction term + + + align:start position:0% +telling us what the interaction term +should be if we're going to form + + align:start position:0% +should be if we're going to form + + + align:start position:0% +should be if we're going to form +regression including do the regression + + align:start position:0% +regression including do the regression + + + align:start position:0% +regression including do the regression +on the interaction factor so it's pretty + + align:start position:0% +on the interaction factor so it's pretty + + + align:start position:0% +on the interaction factor so it's pretty +funky all intertwined here so something + + align:start position:0% +funky all intertwined here so something + + + align:start position:0% +funky all intertwined here so something +strange in our slides this this is + + align:start position:0% +strange in our slides this this is + + + align:start position:0% +strange in our slides this this is +simply I don't know what that is it's + + align:start position:0% +simply I don't know what that is it's + + + align:start position:0% +simply I don't know what that is it's +supposed to be a dot just a + + align:start position:0% +supposed to be a dot just a + + + align:start position:0% +supposed to be a dot just a +multiplication because now we can say + + align:start position:0% +multiplication because now we can say + + + align:start position:0% +multiplication because now we can say +okay how do we form the contrast between + + align:start position:0% +okay how do we form the contrast between + + + align:start position:0% +okay how do we form the contrast between +our different combinations of settings + + align:start position:0% +our different combinations of settings + + + align:start position:0% +our different combinations of settings +in order to estimate the effect of a and + + align:start position:0% +in order to estimate the effect of a and + + + align:start position:0% +in order to estimate the effect of a and +essentially what we're going to be doing + + align:start position:0% +essentially what we're going to be doing + + + align:start position:0% +essentially what we're going to be doing +is forming the average between the high + + align:start position:0% +is forming the average between the high + + + align:start position:0% +is forming the average between the high +for a this column and this column or the + + align:start position:0% +for a this column and this column or the + + + align:start position:0% +for a this column and this column or the +difference between the average of those + + align:start position:0% +difference between the average of those + + + align:start position:0% +difference between the average of those +two columns and these two settings so + + align:start position:0% +two columns and these two settings so + + + align:start position:0% +two columns and these two settings so +I'm basically forming the contrast in + + align:start position:0% +I'm basically forming the contrast in + + + align:start position:0% +I'm basically forming the contrast in +each case for each factor is the + + align:start position:0% +each case for each factor is the + + + align:start position:0% +each case for each factor is the +difference between the high and the low + + align:start position:0% +difference between the high and the low + + + align:start position:0% +difference between the high and the low +setting and so that's actually why we + + align:start position:0% +setting and so that's actually why we + + + align:start position:0% +setting and so that's actually why we +need the interaction factor so we can we + + align:start position:0% +need the interaction factor so we can we + + + align:start position:0% +need the interaction factor so we can we +can look at the high settings for the + + align:start position:0% +can look at the high settings for the + + + align:start position:0% +can look at the high settings for the +interaction the the a B and the 1 and + + align:start position:0% +interaction the the a B and the 1 and + + + align:start position:0% +interaction the the a B and the 1 and +then the minus a and the minus B where + + align:start position:0% +then the minus a and the minus B where + + + align:start position:0% +then the minus a and the minus B where +are these coming from a much better way + + align:start position:0% +are these coming from a much better way + + + align:start position:0% +are these coming from a much better way +to picture this is if we look at this + + align:start position:0% +to picture this is if we look at this + + + align:start position:0% +to picture this is if we look at this +kind of graphically so what I'm going to + + align:start position:0% +kind of graphically so what I'm going to + + + align:start position:0% +kind of graphically so what I'm going to +do here first is generalize this is a 2 + + align:start position:0% +do here first is generalize this is a 2 + + + align:start position:0% +do here first is generalize this is a 2 +to the 3 design in more general terms we + + align:start position:0% +to the 3 design in more general terms we + + + align:start position:0% +to the 3 design in more general terms we +can do a full factorial with any number + + align:start position:0% +can do a full factorial with any number + + + align:start position:0% +can do a full factorial with any number +of factors and form this sort of + + align:start position:0% +of factors and form this sort of + + + align:start position:0% +of factors and form this sort of +hypercube again with corner points at + + align:start position:0% +hypercube again with corner points at + + + align:start position:0% +hypercube again with corner points at +all komban + + align:start position:0% +all komban + + + align:start position:0% +all komban +of the high and low values or levels for + + align:start position:0% +of the high and low values or levels for + + + align:start position:0% +of the high and low values or levels for +each of our setting and on that + + align:start position:0% +each of our setting and on that + + + align:start position:0% +each of our setting and on that +hypercube so now I've got a factor B + + align:start position:0% +hypercube so now I've got a factor B + + + align:start position:0% +hypercube so now I've got a factor B +factor and C factor this is a nice + + align:start position:0% +factor and C factor this is a nice + + + align:start position:0% +factor and C factor this is a nice +picture performing what that contrast is + + align:start position:0% +picture performing what that contrast is + + + align:start position:0% +picture performing what that contrast is +doing and how we rest amay ting the + + align:start position:0% +doing and how we rest amay ting the + + + align:start position:0% +doing and how we rest amay ting the +average effect of changing one factor at + + align:start position:0% +average effect of changing one factor at + + + align:start position:0% +average effect of changing one factor at +a time on this picture right so just + + align:start position:0% +a time on this picture right so just + + + align:start position:0% +a time on this picture right so just +conceptually and are intuitively if you + + align:start position:0% +conceptually and are intuitively if you + + + align:start position:0% +conceptually and are intuitively if you +were trying to form an estimate of the + + align:start position:0% +were trying to form an estimate of the + + + align:start position:0% +were trying to form an estimate of the +factor effect a associated with some + + align:start position:0% +factor effect a associated with some + + + align:start position:0% +factor effect a associated with some +variable X 1 notice that what we've got + + align:start position:0% +variable X 1 notice that what we've got + + + align:start position:0% +variable X 1 notice that what we've got +at all of these settings on the Left + + align:start position:0% +at all of these settings on the Left + + + align:start position:0% +at all of these settings on the Left +sort of shaded with the blue those are + + align:start position:0% +sort of shaded with the blue those are + + + align:start position:0% +sort of shaded with the blue those are +all low settings for our a factor + + align:start position:0% +all low settings for our a factor + + + align:start position:0% +all low settings for our a factor +I'm varying B and C also but in for all + + align:start position:0% +I'm varying B and C also but in for all + + + align:start position:0% +I'm varying B and C also but in for all +of those I'm holding the a factor at the + + align:start position:0% +of those I'm holding the a factor at the + + + align:start position:0% +of those I'm holding the a factor at the +low value and then similarly on the red + + align:start position:0% +low value and then similarly on the red + + + align:start position:0% +low value and then similarly on the red +side I'm holding the a factor at the + + align:start position:0% +side I'm holding the a factor at the + + + align:start position:0% +side I'm holding the a factor at the +high value in all of those cases may be + + align:start position:0% +high value in all of those cases may be + + + align:start position:0% +high value in all of those cases may be +varying other things too but if I think + + align:start position:0% +varying other things too but if I think + + + align:start position:0% +varying other things too but if I think +that those other effects are basically + + align:start position:0% +that those other effects are basically + + + align:start position:0% +that those other effects are basically +balancing out now what I've got is a + + align:start position:0% +balancing out now what I've got is a + + + align:start position:0% +balancing out now what I've got is a +difference between the a high and the a + + align:start position:0% +difference between the a high and the a + + + align:start position:0% +difference between the a high and the a +low as a net overall estimate of the + + align:start position:0% +low as a net overall estimate of the + + + align:start position:0% +low as a net overall estimate of the +total effect of changing variable x1 + + align:start position:0% +total effect of changing variable x1 + + + align:start position:0% +total effect of changing variable x1 +changing the variable associated with a + + align:start position:0% +changing the variable associated with a + + + align:start position:0% +changing the variable associated with a +and that's all that the contrasts are + + align:start position:0% +and that's all that the contrasts are + + + align:start position:0% +and that's all that the contrasts are +doing they're simply saying ok the the + + align:start position:0% +doing they're simply saying ok the the + + + align:start position:0% +doing they're simply saying ok the the +high contrast is all of the places where + + align:start position:0% +high contrast is all of the places where + + + align:start position:0% +high contrast is all of the places where +a is set high - all of the places where + + align:start position:0% +a is set high - all of the places where + + + align:start position:0% +a is set high - all of the places where +a is set low form that difference recall + + align:start position:0% +a is set low form that difference recall + + + align:start position:0% +a is set low form that difference recall +that we've got I need to take the + + align:start position:0% +that we've got I need to take the + + + align:start position:0% +that we've got I need to take the +average so in each of these cases I've + + align:start position:0% +average so in each of these cases I've + + + align:start position:0% +average so in each of these cases I've +got four points at high and four points + + align:start position:0% +got four points at high and four points + + + align:start position:0% +got four points at high and four points +at low so I'm taking the average and + + align:start position:0% +at low so I'm taking the average and + + + align:start position:0% +at low so I'm taking the average and +taking the difference that's my estimate + + align:start position:0% +taking the difference that's my estimate + + + align:start position:0% +taking the difference that's my estimate +of the total net net effect question + + align:start position:0% + + + + align:start position:0% + +okay say that question again I've got + + align:start position:0% +okay say that question again I've got + + + align:start position:0% +okay say that question again I've got +here's AC so so so far what we've done + + align:start position:0% +here's AC so so so far what we've done + + + align:start position:0% +here's AC so so so far what we've done +is only estimated one of the contrasts + + align:start position:0% +is only estimated one of the contrasts + + + align:start position:0% +is only estimated one of the contrasts +it looks like you're actually getting + + align:start position:0% +it looks like you're actually getting + + + align:start position:0% +it looks like you're actually getting +close to estimating a different a + + align:start position:0% +close to estimating a different a + + + align:start position:0% +close to estimating a different a +different term in a model so so what we + + align:start position:0% +different term in a model so so what we + + + align:start position:0% +different term in a model so so what we +did here was just to estimate the a + + align:start position:0% +did here was just to estimate the a + + + align:start position:0% +did here was just to estimate the a +affection I would not also need to do + + align:start position:0% +affection I would not also need to do + + + align:start position:0% +affection I would not also need to do +the same thing for the B effect okay so + + align:start position:0% +the same thing for the B effect okay so + + + align:start position:0% +the same thing for the B effect okay so +that's telling me if I vary x2 and I can + + align:start position:0% +that's telling me if I vary x2 and I can + + + align:start position:0% +that's telling me if I vary x2 and I can +similarly do that for the C effect but + + align:start position:0% +similarly do that for the C effect but + + + align:start position:0% +similarly do that for the C effect but +then there's a question well what if + + align:start position:0% +then there's a question well what if + + + align:start position:0% +then there's a question well what if +there is an interaction between two of + + align:start position:0% +there is an interaction between two of + + + align:start position:0% +there is an interaction between two of +these terms and one can also form a + + align:start position:0% +these terms and one can also form a + + + align:start position:0% +these terms and one can also form a +contrast or an interaction effect and + + align:start position:0% +contrast or an interaction effect and + + + align:start position:0% +contrast or an interaction effect and +maybe this is not exactly what you are + + align:start position:0% +maybe this is not exactly what you are + + + align:start position:0% +maybe this is not exactly what you are +describing but it's getting close to + + align:start position:0% +describing but it's getting close to + + + align:start position:0% +describing but it's getting close to +other ways of combining some of these + + align:start position:0% +other ways of combining some of these + + + align:start position:0% +other ways of combining some of these +effects so it turns out what this does + + align:start position:0% +effects so it turns out what this does + + + align:start position:0% +effects so it turns out what this does +is makes a balanced combination of our + + align:start position:0% +is makes a balanced combination of our + + + align:start position:0% +is makes a balanced combination of our +data points to be able to take advantage + + align:start position:0% +data points to be able to take advantage + + + align:start position:0% +data points to be able to take advantage +of that a B column this is just + + align:start position:0% +of that a B column this is just + + + align:start position:0% +of that a B column this is just +basically taking the high and low + + align:start position:0% +basically taking the high and low + + + align:start position:0% +basically taking the high and low +combinations and forming that estimate + + align:start position:0% +combinations and forming that estimate + + + align:start position:0% +combinations and forming that estimate +of the a/b interaction effect using the + + align:start position:0% +of the a/b interaction effect using the + + + align:start position:0% +of the a/b interaction effect using the +contrast between these between these + + align:start position:0% +contrast between these between these + + + align:start position:0% +contrast between these between these +points now there would also be another + + align:start position:0% +points now there would also be another + + + align:start position:0% +points now there would also be another +contrast for the BC interaction if you + + align:start position:0% +contrast for the BC interaction if you + + + align:start position:0% +contrast for the BC interaction if you +sort of rotated these around and formed + + align:start position:0% +sort of rotated these around and formed + + + align:start position:0% +sort of rotated these around and formed +the plane where you took took the + + align:start position:0% +the plane where you took took the + + + align:start position:0% +the plane where you took took the +high/low combinations of B and C instead + + align:start position:0% +high/low combinations of B and C instead + + + align:start position:0% +high/low combinations of B and C instead +of a and B okay + + align:start position:0% + + + + align:start position:0% + +is that get at your question a rigidity + + align:start position:0% +is that get at your question a rigidity + + + align:start position:0% +is that get at your question a rigidity +you can always form different + + align:start position:0% +you can always form different + + + align:start position:0% +you can always form different +combinations of things the question is + + align:start position:0% +combinations of things the question is + + + align:start position:0% +combinations of things the question is +what combination do you need in order to + + align:start position:0% +what combination do you need in order to + + + align:start position:0% +what combination do you need in order to +be able to estimate the coefficient in + + align:start position:0% +be able to estimate the coefficient in + + + align:start position:0% +be able to estimate the coefficient in +the model yes I mean I think you can + + align:start position:0% +the model yes I mean I think you can + + + align:start position:0% +the model yes I mean I think you can +generate this that that cross thing is + + align:start position:0% +generate this that that cross thing is + + + align:start position:0% +generate this that that cross thing is +intuitive in the sense only in the sense + + align:start position:0% +intuitive in the sense only in the sense + + + align:start position:0% +intuitive in the sense only in the sense +that it corresponds nicely you can + + align:start position:0% +that it corresponds nicely you can + + + align:start position:0% +that it corresponds nicely you can +generate it once you have this column so + + align:start position:0% +generate it once you have this column so + + + align:start position:0% +generate it once you have this column so +now I can connect up the high points and + + align:start position:0% +now I can connect up the high points and + + + align:start position:0% +now I can connect up the high points and +that would be one plane connect up the + + align:start position:0% +that would be one plane connect up the + + + align:start position:0% +that would be one plane connect up the +low points that's my other plane and + + align:start position:0% +low points that's my other plane and + + + align:start position:0% +low points that's my other plane and +then I take the difference but it's not + + align:start position:0% +then I take the difference but it's not + + + align:start position:0% +then I take the difference but it's not +entirely intuitive why that particular + + align:start position:0% +entirely intuitive why that particular + + + align:start position:0% +entirely intuitive why that particular +combination gives you the estimate of + + align:start position:0% +combination gives you the estimate of + + + align:start position:0% +combination gives you the estimate of +that coefficient I agree with that so + + align:start position:0% +that coefficient I agree with that so + + + align:start position:0% +that coefficient I agree with that so +this is kind of the shorthand that gives + + align:start position:0% +this is kind of the shorthand that gives + + + align:start position:0% +this is kind of the shorthand that gives +the answer in fact I don't have a good + + align:start position:0% +the answer in fact I don't have a good + + + align:start position:0% +the answer in fact I don't have a good +intuitive explanation just looking + + align:start position:0% +intuitive explanation just looking + + + align:start position:0% +intuitive explanation just looking +purely at this picture why that + + align:start position:0% +purely at this picture why that + + + align:start position:0% +purely at this picture why that +estimates the interaction it's the + + align:start position:0% +estimates the interaction it's the + + + align:start position:0% +estimates the interaction it's the +closest I can come is almost in two + + align:start position:0% +closest I can come is almost in two + + + align:start position:0% +closest I can come is almost in two +dimensions instead of three with these + + align:start position:0% +dimensions instead of three with these + + + align:start position:0% +dimensions instead of three with these +interaction plots that we we've drawn + + align:start position:0% +interaction plots that we we've drawn + + + align:start position:0% +interaction plots that we we've drawn +before so the the basic interaction plot + + align:start position:0% +before so the the basic interaction plot + + + align:start position:0% +before so the the basic interaction plot +would look and say if I just have x1 and + + align:start position:0% +would look and say if I just have x1 and + + + align:start position:0% +would look and say if I just have x1 and +x2 values by just drawing as here's my + + align:start position:0% +x2 values by just drawing as here's my + + + align:start position:0% +x2 values by just drawing as here's my +output as I vary x1 from high to low + + align:start position:0% +output as I vary x1 from high to low + + + align:start position:0% +output as I vary x1 from high to low +holding x2 low that would be one effect + + align:start position:0% +holding x2 low that would be one effect + + + align:start position:0% +holding x2 low that would be one effect +if now I let X to be high + + align:start position:0% +if now I let X to be high + + + align:start position:0% +if now I let X to be high +I don't have just an offset but I've got + + align:start position:0% +I don't have just an offset but I've got + + + align:start position:0% +I don't have just an offset but I've got +a different Delta here than here that + + align:start position:0% +a different Delta here than here that + + + align:start position:0% +a different Delta here than here that +means that in combination x1 and x2 work + + align:start position:0% +means that in combination x1 and x2 work + + + align:start position:0% +means that in combination x1 and x2 work +together to do something different than + + align:start position:0% +together to do something different than + + + align:start position:0% +together to do something different than +purely x1 or x2 there is not just purely + + align:start position:0% +purely x1 or x2 there is not just purely + + + align:start position:0% +purely x1 or x2 there is not just purely +an additive a effect in the B effect but + + align:start position:0% +an additive a effect in the B effect but + + + align:start position:0% +an additive a effect in the B effect but +there is an a/b effect and in three + + align:start position:0% +there is an a/b effect and in three + + + align:start position:0% +there is an a/b effect and in three +dimensions so so in two dimensions + + align:start position:0% +dimensions so so in two dimensions + + + align:start position:0% +dimensions so so in two dimensions +essentially what you're doing is looking + + align:start position:0% +essentially what you're doing is looking + + + align:start position:0% +essentially what you're doing is looking +at forming the Delta from this + + align:start position:0% +at forming the Delta from this + + + align:start position:0% +at forming the Delta from this +combination and this combination and + + align:start position:0% +combination and this combination and + + + align:start position:0% +combination and this combination and +saying there is a difference an extra + + align:start position:0% +saying there is a difference an extra + + + align:start position:0% +saying there is a difference an extra +Delta between the two in 3d it's a + + align:start position:0% +Delta between the two in 3d it's a + + + align:start position:0% +Delta between the two in 3d it's a +little harder to to see but I think it's + + align:start position:0% +little harder to to see but I think it's + + + align:start position:0% +little harder to to see but I think it's +doing conceptually that same thing yeah + + align:start position:0% + + + + align:start position:0% + +oh I think we did in the two factor so + + align:start position:0% +oh I think we did in the two factor so + + + align:start position:0% +oh I think we did in the two factor so +the four is basically just because I'm + + align:start position:0% +the four is basically just because I'm + + + align:start position:0% +the four is basically just because I'm +taking the average from each of the this + + align:start position:0% +taking the average from each of the this + + + align:start position:0% +taking the average from each of the this +point has four points so I'm just taking + + align:start position:0% +point has four points so I'm just taking + + + align:start position:0% +point has four points so I'm just taking +me the average from that the difference + + align:start position:0% +me the average from that the difference + + + align:start position:0% +me the average from that the difference +from that so the four is coming from the + + align:start position:0% +from that so the four is coming from the + + + align:start position:0% +from that so the four is coming from the +number of points I had in each average + + align:start position:0% +number of points I had in each average + + + align:start position:0% +number of points I had in each average +that's an estimate of the total effect + + align:start position:0% +that's an estimate of the total effect + + + align:start position:0% +that's an estimate of the total effect +then there's one additional subtle point + + align:start position:0% +then there's one additional subtle point + + + align:start position:0% +then there's one additional subtle point +which is how do I get from that factor + + align:start position:0% +which is how do I get from that factor + + + align:start position:0% +which is how do I get from that factor +total of net effect main effect a or + + align:start position:0% +total of net effect main effect a or + + + align:start position:0% +total of net effect main effect a or +interaction effect a B to an estimate of + + align:start position:0% +interaction effect a B to an estimate of + + + align:start position:0% +interaction effect a B to an estimate of +the model coefficient and that's where + + align:start position:0% +the model coefficient and that's where + + + align:start position:0% +the model coefficient and that's where +some scaling comes into play what we've + + align:start position:0% +some scaling comes into play what we've + + + align:start position:0% +some scaling comes into play what we've +done in these pictures is scaled our x1 + + align:start position:0% +done in these pictures is scaled our x1 + + + align:start position:0% +done in these pictures is scaled our x1 +and x2 to a low of minus one and a high + + align:start position:0% +and x2 to a low of minus one and a high + + + align:start position:0% +and x2 to a low of minus one and a high +of one intermediate point of zero so if + + align:start position:0% +of one intermediate point of zero so if + + + align:start position:0% +of one intermediate point of zero so if +then if the total effect here just + + align:start position:0% +then if the total effect here just + + + align:start position:0% +then if the total effect here just +saying let's say this was the the + + align:start position:0% +saying let's say this was the the + + + align:start position:0% +saying let's say this was the the +overall a effect what I'd like is + + align:start position:0% +overall a effect what I'd like is + + + align:start position:0% +overall a effect what I'd like is +something that goes y equals beta naught + + align:start position:0% +something that goes y equals beta naught + + + align:start position:0% +something that goes y equals beta naught +plus beta 1 X 1 + + align:start position:0% +plus beta 1 X 1 + + + align:start position:0% +plus beta 1 X 1 +and so what I've got is a total range in + + align:start position:0% +and so what I've got is a total range in + + + align:start position:0% +and so what I've got is a total range in +X one of two so I have to basically + + align:start position:0% +X one of two so I have to basically + + + align:start position:0% +X one of two so I have to basically +scale this so that I've got a over 2 X 1 + + align:start position:0% +scale this so that I've got a over 2 X 1 + + + align:start position:0% +scale this so that I've got a over 2 X 1 +as X goes from 0 to 1 I've got half of + + align:start position:0% +as X goes from 0 to 1 I've got half of + + + align:start position:0% +as X goes from 0 to 1 I've got half of +the effect and as X goes from 0 to minus + + align:start position:0% +the effect and as X goes from 0 to minus + + + align:start position:0% +the effect and as X goes from 0 to minus +1 I've got the other half of the effect + + align:start position:0% +1 I've got the other half of the effect + + + align:start position:0% +1 I've got the other half of the effect +so that's where beta 1 is equal to the a + + align:start position:0% +so that's where beta 1 is equal to the a + + + align:start position:0% +so that's where beta 1 is equal to the a +over 2 and that's only true again a lot + + align:start position:0% +over 2 and that's only true again a lot + + + align:start position:0% +over 2 and that's only true again a lot +of what I'm saying is only true if we're + + align:start position:0% +of what I'm saying is only true if we're + + + align:start position:0% +of what I'm saying is only true if we're +using the scale coefficients for X 1 + + align:start position:0% +using the scale coefficients for X 1 + + + align:start position:0% +using the scale coefficients for X 1 +from minus 1 to plus 1 and then all this + + align:start position:0% +from minus 1 to plus 1 and then all this + + + align:start position:0% +from minus 1 to plus 1 and then all this +magical shorthand of these column tables + + align:start position:0% +magical shorthand of these column tables + + + align:start position:0% +magical shorthand of these column tables +the multiplication of column tables the + + align:start position:0% +the multiplication of column tables the + + + align:start position:0% +the multiplication of column tables the +formula formation of these contrasts + + align:start position:0% +formula formation of these contrasts + + + align:start position:0% +formula formation of these contrasts +works out really nicely and so that's + + align:start position:0% +works out really nicely and so that's + + + align:start position:0% +works out really nicely and so that's +where you'll look in the literature and + + align:start position:0% +where you'll look in the literature and + + + align:start position:0% +where you'll look in the literature and +there's so much machinery around this + + align:start position:0% +there's so much machinery around this + + + align:start position:0% +there's so much machinery around this +that makes it relatively quick and easy + + align:start position:0% +that makes it relatively quick and easy + + + align:start position:0% +that makes it relatively quick and easy +ok + + align:start position:0% + + + + align:start position:0% + +so we can extend all of this again to + + align:start position:0% +so we can extend all of this again to + + + align:start position:0% +so we can extend all of this again to +beyond 1 factor or 2 factors to 3 + + align:start position:0% +beyond 1 factor or 2 factors to 3 + + + align:start position:0% +beyond 1 factor or 2 factors to 3 +factors or any k factors so we can + + align:start position:0% +factors or any k factors so we can + + + align:start position:0% +factors or any k factors so we can +consider for example a 2 to the third + + align:start position:0% +consider for example a 2 to the third + + + align:start position:0% +consider for example a 2 to the third +experiment where now we have 3 factors + + align:start position:0% +experiment where now we have 3 factors + + + align:start position:0% +experiment where now we have 3 factors +in X 1 X 2 X 3 or going with sort of an + + align:start position:0% +in X 1 X 2 X 3 or going with sort of an + + + align:start position:0% +in X 1 X 2 X 3 or going with sort of an +A effect via the effect and C effect and + + align:start position:0% +A effect via the effect and C effect and + + + align:start position:0% +A effect via the effect and C effect and +then we can just extend this to the + + align:start position:0% +then we can just extend this to the + + + align:start position:0% +then we can just extend this to the +different treatment combinations and + + align:start position:0% +different treatment combinations and + + + align:start position:0% +different treatment combinations and +essentially what we're doing here is + + align:start position:0% +essentially what we're doing here is + + + align:start position:0% +essentially what we're doing here is +formulating every possible corner point + + align:start position:0% +formulating every possible corner point + + + align:start position:0% +formulating every possible corner point +every possible combination of the high + + align:start position:0% +every possible combination of the high + + + align:start position:0% +every possible combination of the high +and low for each of the settings and the + + align:start position:0% +and low for each of the settings and the + + + align:start position:0% +and low for each of the settings and the +same idea applies here I've indicated + + align:start position:0% +same idea applies here I've indicated + + + align:start position:0% +same idea applies here I've indicated +them indicated them with a plus 1 minus + + align:start position:0% +them indicated them with a plus 1 minus + + + align:start position:0% +them indicated them with a plus 1 minus +1 rather than just a plus minus but it's + + align:start position:0% +1 rather than just a plus minus but it's + + + align:start position:0% +1 rather than just a plus minus but it's +exactly the same idea and you can see + + align:start position:0% +exactly the same idea and you can see + + + align:start position:0% +exactly the same idea and you can see +sort of see already lurking here which + + align:start position:0% +sort of see already lurking here which + + + align:start position:0% +sort of see already lurking here which +runs would you use to estimate the C + + align:start position:0% +runs would you use to estimate the C + + + align:start position:0% +runs would you use to estimate the C +effect that one's sort of leaps out at + + align:start position:0% +effect that one's sort of leaps out at + + + align:start position:0% +effect that one's sort of leaps out at +us as we happen to have ordered this + + align:start position:0% +us as we happen to have ordered this + + + align:start position:0% +us as we happen to have ordered this +caught this this table right I would + + align:start position:0% +caught this this table right I would + + + align:start position:0% +caught this this table right I would +average these runs runs 5 6 7 & 8 + + align:start position:0% +average these runs runs 5 6 7 & 8 + + + align:start position:0% +average these runs runs 5 6 7 & 8 +average runs 1 2 3 & 4 + + align:start position:0% +average runs 1 2 3 & 4 + + + align:start position:0% +average runs 1 2 3 & 4 +take the difference in that my estimate + + align:start position:0% +take the difference in that my estimate + + + align:start position:0% +take the difference in that my estimate +of the sea effect now that's the + + align:start position:0% +of the sea effect now that's the + + + align:start position:0% +of the sea effect now that's the +contrast that I would do again for see + + align:start position:0% +contrast that I would do again for see + + + align:start position:0% +contrast that I would do again for see +if I also want to form contrast for the + + align:start position:0% +if I also want to form contrast for the + + + align:start position:0% +if I also want to form contrast for the +other coefficients it's exactly the same + + align:start position:0% +other coefficients it's exactly the same + + + align:start position:0% +other coefficients it's exactly the same +thing but the the table is not quite + + align:start position:0% +thing but the the table is not quite + + + align:start position:0% +thing but the the table is not quite +worrying oriented to make it leap out at + + align:start position:0% +worrying oriented to make it leap out at + + + align:start position:0% +worrying oriented to make it leap out at +me but essentially for the aid contrast + + align:start position:0% +me but essentially for the aid contrast + + + align:start position:0% +me but essentially for the aid contrast +and just forming those for my a a B + + align:start position:0% +and just forming those for my a a B + + + align:start position:0% +and just forming those for my a a B +that's my plus ones all my pluses and + + align:start position:0% +that's my plus ones all my pluses and + + + align:start position:0% +that's my plus ones all my pluses and +all my minus is forming that as my + + align:start position:0% +all my minus is forming that as my + + + align:start position:0% +all my minus is forming that as my +contrast I can very quickly then + + align:start position:0% +contrast I can very quickly then + + + align:start position:0% +contrast I can very quickly then +estimate that main effect using this big + + align:start position:0% +estimate that main effect using this big + + + align:start position:0% +estimate that main effect using this big +column I can also estimate my + + align:start position:0% +column I can also estimate my + + + align:start position:0% +column I can also estimate my +interaction terms we already talked + + align:start position:0% +interaction terms we already talked + + + align:start position:0% +interaction terms we already talked +about an a/b interaction if I have three + + align:start position:0% +about an a/b interaction if I have three + + + align:start position:0% +about an a/b interaction if I have three +model cuffs or three three factors I can + + align:start position:0% +model cuffs or three three factors I can + + + align:start position:0% +model cuffs or three three factors I can +have three-way interactions where + + align:start position:0% +have three-way interactions where + + + align:start position:0% +have three-way interactions where +depending on all of the settings of a B + + align:start position:0% +depending on all of the settings of a B + + + align:start position:0% +depending on all of the settings of a B +and C I might get a little boost up or + + align:start position:0% +and C I might get a little boost up or + + + align:start position:0% +and C I might get a little boost up or +down different than I would just from a + + align:start position:0% +down different than I would just from a + + + align:start position:0% +down different than I would just from a +B C and even different from the boost I + + align:start position:0% +B C and even different from the boost I + + + align:start position:0% +B C and even different from the boost I +got by having a and B in combination I + + align:start position:0% +got by having a and B in combination I + + + align:start position:0% +got by having a and B in combination I +can have these subtle three-way + + align:start position:0% +can have these subtle three-way + + + align:start position:0% +can have these subtle three-way +interactions and you can form the + + align:start position:0% +interactions and you can form the + + + align:start position:0% +interactions and you can form the +contrast and estimate that effect in a + + align:start position:0% +contrast and estimate that effect in a + + + align:start position:0% +contrast and estimate that effect in a +similar fashion using the ABC + + align:start position:0% +similar fashion using the ABC + + + align:start position:0% +similar fashion using the ABC +interaction column and form the contrast + + align:start position:0% +interaction column and form the contrast + + + align:start position:0% +interaction column and form the contrast +using that two steps to get to here one + + align:start position:0% +using that two steps to get to here one + + + align:start position:0% +using that two steps to get to here one +step is how do i generate this column + + align:start position:0% +step is how do i generate this column + + + align:start position:0% +step is how do i generate this column +and then the second step is then using + + align:start position:0% +and then the second step is then using + + + align:start position:0% +and then the second step is then using +that column to form an estimate of the + + align:start position:0% +that column to form an estimate of the + + + align:start position:0% +that column to form an estimate of the +interaction effect so how do we get to + + align:start position:0% +interaction effect so how do we get to + + + align:start position:0% +interaction effect so how do we get to +ABC column by extension of what I told + + align:start position:0% +ABC column by extension of what I told + + + align:start position:0% +ABC column by extension of what I told +you about the a B column how do you + + align:start position:0% +you about the a B column how do you + + + align:start position:0% +you about the a B column how do you +generate that + + align:start position:0% + + + + align:start position:0% + +just multiply it's kind of this + + align:start position:0% +just multiply it's kind of this + + + align:start position:0% +just multiply it's kind of this +multiplication I just take the a B and C + + align:start position:0% +multiplication I just take the a B and C + + + align:start position:0% +multiplication I just take the a B and C +columns 20 twice multiply out those + + align:start position:0% +columns 20 twice multiply out those + + + align:start position:0% +columns 20 twice multiply out those +factors so minus 1 minus 1 minus 1 gives + + align:start position:0% +factors so minus 1 minus 1 minus 1 gives + + + align:start position:0% +factors so minus 1 minus 1 minus 1 gives +me I overrode it there we go it gives me + + align:start position:0% +me I overrode it there we go it gives me + + + align:start position:0% +me I overrode it there we go it gives me +a minus 1 and I similarly do that for + + align:start position:0% +a minus 1 and I similarly do that for + + + align:start position:0% +a minus 1 and I similarly do that for +all of the columns once I have that then + + align:start position:0% +all of the columns once I have that then + + + align:start position:0% +all of the columns once I have that then +then doing the second step is is pretty + + align:start position:0% +then doing the second step is is pretty + + + align:start position:0% +then doing the second step is is pretty +simple to estimate that that contrast + + align:start position:0% +simple to estimate that that contrast + + + align:start position:0% +simple to estimate that that contrast +now we have to be a once we've got the + + align:start position:0% +now we have to be a once we've got the + + + align:start position:0% +now we have to be a once we've got the +contrast just the differences in the + + align:start position:0% +contrast just the differences in the + + + align:start position:0% +contrast just the differences in the +columns then I do have to do a little + + align:start position:0% +columns then I do have to do a little + + + align:start position:0% +columns then I do have to do a little +bit of that normalization actually I + + align:start position:0% +bit of that normalization actually I + + + align:start position:0% +bit of that normalization actually I +probably am not completely consistent + + align:start position:0% +probably am not completely consistent + + + align:start position:0% +probably am not completely consistent +here + + align:start position:0% +here + + + align:start position:0% +here +the contrast is just the differences + + align:start position:0% +the contrast is just the differences + + + align:start position:0% +the contrast is just the differences +between the the points I then have to do + + align:start position:0% +between the the points I then have to do + + + align:start position:0% +between the the points I then have to do +the average over the number of points + + align:start position:0% +the average over the number of points + + + align:start position:0% +the average over the number of points +whoops well two things to form the + + align:start position:0% +whoops well two things to form the + + + align:start position:0% +whoops well two things to form the +estimate of the overall effect first off + + align:start position:0% +estimate of the overall effect first off + + + align:start position:0% +estimate of the overall effect first off +I have to divide by the number of points + + align:start position:0% +I have to divide by the number of points + + + align:start position:0% +I have to divide by the number of points +I had in each of those those contrasts + + align:start position:0% +I had in each of those those contrasts + + + align:start position:0% +I had in each of those those contrasts +which has been basically just 2 to the K + + align:start position:0% +which has been basically just 2 to the K + + + align:start position:0% +which has been basically just 2 to the K +minus 1 right when we had that cube with + + align:start position:0% +minus 1 right when we had that cube with + + + align:start position:0% +minus 1 right when we had that cube with +8 points it was 2 to the 3rd 8 divided + + align:start position:0% +8 points it was 2 to the 3rd 8 divided + + + align:start position:0% +8 points it was 2 to the 3rd 8 divided +by 2 because I'm forming half of the + + align:start position:0% +by 2 because I'm forming half of the + + + align:start position:0% +by 2 because I'm forming half of the +points in one contrast half of the + + align:start position:0% +points in one contrast half of the + + + align:start position:0% +points in one contrast half of the +points in the other and then this end + + align:start position:0% +points in the other and then this end + + + align:start position:0% +points in the other and then this end +which we haven't talked about very much + + align:start position:0% +which we haven't talked about very much + + + align:start position:0% +which we haven't talked about very much +is just the replicants I can do multiple + + align:start position:0% +is just the replicants I can do multiple + + + align:start position:0% +is just the replicants I can do multiple +runs of each experimental point so I can + + align:start position:0% +runs of each experimental point so I can + + + align:start position:0% +runs of each experimental point so I can +also average those in right so it's also + + align:start position:0% +also average those in right so it's also + + + align:start position:0% +also average those in right so it's also +possible that we've gotten more than one + + align:start position:0% +possible that we've gotten more than one + + + align:start position:0% +possible that we've gotten more than one +run at every experimental combination + + align:start position:0% +run at every experimental combination + + + align:start position:0% +run at every experimental combination +point so that's how we can estimate + + align:start position:0% +point so that's how we can estimate + + + align:start position:0% +point so that's how we can estimate +those those effects and then once we + + align:start position:0% +those those effects and then once we + + + align:start position:0% +those those effects and then once we +have that for example here that's how we + + align:start position:0% +have that for example here that's how we + + + align:start position:0% +have that for example here that's how we +get the in the 2 to the 3rd we get a 1/4 + + align:start position:0% +get the in the 2 to the 3rd we get a 1/4 + + + align:start position:0% +get the in the 2 to the 3rd we get a 1/4 +factor that we saw earlier for the 3 + + align:start position:0% +factor that we saw earlier for the 3 + + + align:start position:0% +factor that we saw earlier for the 3 +factor you know cube in + + align:start position:0% +factor you know cube in + + + align:start position:0% +factor you know cube in +three-dimensional space as an estimate + + align:start position:0% +three-dimensional space as an estimate + + + align:start position:0% +three-dimensional space as an estimate +for the overall effect + + align:start position:0% + + + + align:start position:0% + +okay now another point is here I'm + + align:start position:0% +okay now another point is here I'm + + + align:start position:0% +okay now another point is here I'm +talking about estimating our model using + + align:start position:0% +talking about estimating our model using + + + align:start position:0% +talking about estimating our model using +these contrasts and factor effects and + + align:start position:0% +these contrasts and factor effects and + + + align:start position:0% +these contrasts and factor effects and +another approach and probably the + + align:start position:0% +another approach and probably the + + + align:start position:0% +another approach and probably the +approach that you would end up using + + align:start position:0% +approach that you would end up using + + + align:start position:0% +approach that you would end up using +more often if you actually had you know + + align:start position:0% +more often if you actually had you know + + + align:start position:0% +more often if you actually had you know +computers handy is to do over regression + + align:start position:0% +computers handy is to do over regression + + + align:start position:0% +computers handy is to do over regression +right take your data put it in solve the + + align:start position:0% +right take your data put it in solve the + + + align:start position:0% +right take your data put it in solve the +solve the regression equations and + + align:start position:0% +solve the regression equations and + + + align:start position:0% +solve the regression equations and +regress to get your estimate of your + + align:start position:0% +regress to get your estimate of your + + + align:start position:0% +regress to get your estimate of your +coefficients and essentially these big + + align:start position:0% +coefficients and essentially these big + + + align:start position:0% +coefficients and essentially these big +tables that we talked about these + + align:start position:0% +tables that we talked about these + + + align:start position:0% +tables that we talked about these +combinations are still critical and very + + align:start position:0% +combinations are still critical and very + + + align:start position:0% +combinations are still critical and very +very useful because that's basically how + + align:start position:0% +very useful because that's basically how + + + align:start position:0% +very useful because that's basically how +you form the X matrix that describes the + + align:start position:0% +you form the X matrix that describes the + + + align:start position:0% +you form the X matrix that describes the +combinations of all of your factor + + align:start position:0% +combinations of all of your factor + + + align:start position:0% +combinations of all of your factor +levels that you feed into the regression + + align:start position:0% +levels that you feed into the regression + + + align:start position:0% +levels that you feed into the regression +this is your back with your coded values + + align:start position:0% +this is your back with your coded values + + + align:start position:0% +this is your back with your coded values +from minus 1 to plus 1 this is your X + + align:start position:0% +from minus 1 to plus 1 this is your X + + + align:start position:0% +from minus 1 to plus 1 this is your X +matrix right there because what you're + + align:start position:0% +matrix right there because what you're + + + align:start position:0% +matrix right there because what you're +trying to do is estimate a beta naught + + align:start position:0% +trying to do is estimate a beta naught + + + align:start position:0% +trying to do is estimate a beta naught +but you know a beta 1 and the beta 2 and + + align:start position:0% +but you know a beta 1 and the beta 2 and + + + align:start position:0% +but you know a beta 1 and the beta 2 and +a beta 3 oops beta 3 and then also + + align:start position:0% +a beta 3 oops beta 3 and then also + + + align:start position:0% +a beta 3 oops beta 3 and then also +trying to estimate these interaction + + align:start position:0% +trying to estimate these interaction + + + align:start position:0% +trying to estimate these interaction +terms a beta 1 2 a beta 1 3 beta 2 3 and + + align:start position:0% +terms a beta 1 2 a beta 1 3 beta 2 3 and + + + align:start position:0% +terms a beta 1 2 a beta 1 3 beta 2 3 and +even a beta 1 2 3 and so you're + + align:start position:0% +even a beta 1 2 3 and so you're + + + align:start position:0% +even a beta 1 2 3 and so you're +basically fictitiously creating these as + + align:start position:0% +basically fictitiously creating these as + + + align:start position:0% +basically fictitiously creating these as +additional variables for the product of + + align:start position:0% +additional variables for the product of + + + align:start position:0% +additional variables for the product of +X 1 X 2 X 3 in your regression so you + + align:start position:0% +X 1 X 2 X 3 in your regression so you + + + align:start position:0% +X 1 X 2 X 3 in your regression so you +need this this table even if you're + + align:start position:0% +need this this table even if you're + + + align:start position:0% +need this this table even if you're +doing regression in order to be able to + + align:start position:0% +doing regression in order to be able to + + + align:start position:0% +doing regression in order to be able to +set up the regression if you want to + + align:start position:0% +set up the regression if you want to + + + align:start position:0% +set up the regression if you want to +also include these interaction terms in + + align:start position:0% +also include these interaction terms in + + + align:start position:0% +also include these interaction terms in +your regression model you have to create + + align:start position:0% +your regression model you have to create + + + align:start position:0% +your regression model you have to create +sort of fictitious columns of data based + + align:start position:0% +sort of fictitious columns of data based + + + align:start position:0% +sort of fictitious columns of data based +on those interactions the product of + + align:start position:0% +on those interactions the product of + + + align:start position:0% +on those interactions the product of +your three input settings and this is + + align:start position:0% +your three input settings and this is + + + align:start position:0% +your three input settings and this is +basically telling you exactly what those + + align:start position:0% +basically telling you exactly what those + + + align:start position:0% +basically telling you exactly what those +were + + align:start position:0% +were + + + align:start position:0% +were +so this is essentially showing that that + + align:start position:0% +so this is essentially showing that that + + + align:start position:0% +so this is essentially showing that that +same thing I just described in words + + align:start position:0% +same thing I just described in words + + + align:start position:0% +same thing I just described in words +what we're talking about here is + + align:start position:0% +what we're talking about here is + + + align:start position:0% +what we're talking about here is +basically setting up to do the + + align:start position:0% +basically setting up to do the + + + align:start position:0% +basically setting up to do the +pseudo-inverse + + align:start position:0% +pseudo-inverse + + + align:start position:0% +pseudo-inverse +when I've got my data with my X matrix + + align:start position:0% +when I've got my data with my X matrix + + + align:start position:0% +when I've got my data with my X matrix +being my setup of my input conditions + + align:start position:0% +being my setup of my input conditions + + + align:start position:0% +being my setup of my input conditions +and then Y being my output and then beta + + align:start position:0% +and then Y being my output and then beta + + + align:start position:0% +and then Y being my output and then beta +being my vector of coefficients with + + align:start position:0% +being my vector of coefficients with + + + align:start position:0% +being my vector of coefficients with +both the mean the main effects and the + + align:start position:0% +both the mean the main effects and the + + + align:start position:0% +both the mean the main effects and the +interaction effects so I would have to + + align:start position:0% +interaction effects so I would have to + + + align:start position:0% +interaction effects so I would have to +create the column of the X 1 X 2 product + + align:start position:0% +create the column of the X 1 X 2 product + + + align:start position:0% +create the column of the X 1 X 2 product +in order to be able to do that and then + + align:start position:0% +in order to be able to do that and then + + + align:start position:0% +in order to be able to do that and then +you can see again here the relationship + + align:start position:0% +you can see again here the relationship + + + align:start position:0% +you can see again here the relationship +between the contrasts idea and the + + align:start position:0% +between the contrasts idea and the + + + align:start position:0% +between the contrasts idea and the +regression idea that comes out ok + + align:start position:0% +regression idea that comes out ok + + + align:start position:0% +regression idea that comes out ok +relatively clear any questions on that + + align:start position:0% +relatively clear any questions on that + + + align:start position:0% +relatively clear any questions on that +ok so now we've estimated coefficients + + align:start position:0% +ok so now we've estimated coefficients + + + align:start position:0% +ok so now we've estimated coefficients +we've estimated effects either in the + + align:start position:0% +we've estimated effects either in the + + + align:start position:0% +we've estimated effects either in the +regression or the or the contrast + + align:start position:0% +regression or the or the contrast + + + align:start position:0% +regression or the or the contrast +approach a key question is you do that + + align:start position:0% +approach a key question is you do that + + + align:start position:0% +approach a key question is you do that +you get a value for a you know the a + + align:start position:0% +you get a value for a you know the a + + + align:start position:0% +you get a value for a you know the a +effect that's nonzero do you think it's + + align:start position:0% +effect that's nonzero do you think it's + + + align:start position:0% +effect that's nonzero do you think it's +significant or not is it real or not or + + align:start position:0% +significant or not is it real or not or + + + align:start position:0% +significant or not is it real or not or +would you have observed that amount of a + + align:start position:0% +would you have observed that amount of a + + + align:start position:0% +would you have observed that amount of a +by chance alone given random noise in + + align:start position:0% +by chance alone given random noise in + + + align:start position:0% +by chance alone given random noise in +your experiment this is exactly back to + + align:start position:0% +your experiment this is exactly back to + + + align:start position:0% +your experiment this is exactly back to +the ANOVA question that we were asking + + align:start position:0% +the ANOVA question that we were asking + + + align:start position:0% +the ANOVA question that we were asking +earlier I'd like to know the + + align:start position:0% +earlier I'd like to know the + + + align:start position:0% +earlier I'd like to know the +significance of these effects is it + + align:start position:0% +significance of these effects is it + + + align:start position:0% +significance of these effects is it +large enough to give me 90% confidence + + align:start position:0% +large enough to give me 90% confidence + + + align:start position:0% +large enough to give me 90% confidence +or 95% confidence that it's real that it + + align:start position:0% +or 95% confidence that it's real that it + + + align:start position:0% +or 95% confidence that it's real that it +wouldn't have occurred by chance alone + + align:start position:0% +wouldn't have occurred by chance alone + + + align:start position:0% +wouldn't have occurred by chance alone +and so essentially what we want to do is + + align:start position:0% +and so essentially what we want to do is + + + align:start position:0% +and so essentially what we want to do is +run the ANOVA for each of our effects + + align:start position:0% +run the ANOVA for each of our effects + + + align:start position:0% +run the ANOVA for each of our effects +each of our if I have you know three + + align:start position:0% +each of our if I have you know three + + + align:start position:0% +each of our if I have you know three +factors I'd like to know is the main + + align:start position:0% +factors I'd like to know is the main + + + align:start position:0% +factors I'd like to know is the main +effect associated with factor 2 is that + + align:start position:0% +effect associated with factor 2 is that + + + align:start position:0% +effect associated with factor 2 is that +significant I can also do that for + + align:start position:0% +significant I can also do that for + + + align:start position:0% +significant I can also do that for +interaction effects I've and very often + + align:start position:0% +interaction effects I've and very often + + + align:start position:0% +interaction effects I've and very often +you might see large main effects but you + + align:start position:0% +you might see large main effects but you + + + align:start position:0% +you might see large main effects but you +want to ask the question + + align:start position:0% +want to ask the question + + + align:start position:0% +want to ask the question +is there really an interaction between + + align:start position:0% +is there really an interaction between + + + align:start position:0% +is there really an interaction between +these two do I can I think of them as + + align:start position:0% +these two do I can I think of them as + + + align:start position:0% +these two do I can I think of them as +separable coefficients or separable + + align:start position:0% +separable coefficients or separable + + + align:start position:0% +separable coefficients or separable +knobs on my equipment or do I have to + + align:start position:0% +knobs on my equipment or do I have to + + + align:start position:0% +knobs on my equipment or do I have to +think of them as highly coupled I'd like + + align:start position:0% +think of them as highly coupled I'd like + + + align:start position:0% +think of them as highly coupled I'd like +to know the significance of the + + align:start position:0% +to know the significance of the + + + align:start position:0% +to know the significance of the +interaction effect so we essentially + + align:start position:0% +interaction effect so we essentially + + + align:start position:0% +interaction effect so we essentially +just use the ANOVA approach fairly + + align:start position:0% +just use the ANOVA approach fairly + + + align:start position:0% +just use the ANOVA approach fairly +directly but what we're doing is forming + + align:start position:0% +directly but what we're doing is forming + + + align:start position:0% +directly but what we're doing is forming +an estimate of the total deviations + + align:start position:0% +an estimate of the total deviations + + + align:start position:0% +an estimate of the total deviations +associated with that effect the sum of + + align:start position:0% +associated with that effect the sum of + + + align:start position:0% +associated with that effect the sum of +squared deviations which turns out to be + + align:start position:0% +squared deviations which turns out to be + + + align:start position:0% +squared deviations which turns out to be +the contrast squared and then divided by + + align:start position:0% +the contrast squared and then divided by + + + align:start position:0% +the contrast squared and then divided by +the N over 2k + + align:start position:0% +the N over 2k + + + align:start position:0% +the N over 2k +factor there's a homework problem set + + align:start position:0% +factor there's a homework problem set + + + align:start position:0% +factor there's a homework problem set +where you get to help derive why that is + + align:start position:0% +where you get to help derive why that is + + + align:start position:0% +where you get to help derive why that is +true or convince yourself why that is + + align:start position:0% +true or convince yourself why that is + + + align:start position:0% +true or convince yourself why that is +true but essentially you're looking + + align:start position:0% +true but essentially you're looking + + + align:start position:0% +true but essentially you're looking +forward to it I can see but what that + + align:start position:0% +forward to it I can see but what that + + + align:start position:0% +forward to it I can see but what that +lets us do is look again at the total + + align:start position:0% +lets us do is look again at the total + + + align:start position:0% +lets us do is look again at the total +amount of of magnitude of sum of squared + + align:start position:0% +amount of of magnitude of sum of squared + + + align:start position:0% +amount of of magnitude of sum of squared +deviations around a mean associated with + + align:start position:0% +deviations around a mean associated with + + + align:start position:0% +deviations around a mean associated with +that effect and then look at that in + + align:start position:0% +that effect and then look at that in + + + align:start position:0% +that effect and then look at that in +comparison to some estimate of the + + align:start position:0% +comparison to some estimate of the + + + align:start position:0% +comparison to some estimate of the +random noise and do an app test just + + align:start position:0% +random noise and do an app test just + + + align:start position:0% +random noise and do an app test just +like we normally do with ANOVA so you + + align:start position:0% +like we normally do with ANOVA so you + + + align:start position:0% +like we normally do with ANOVA so you +can start to again do that if you've got + + align:start position:0% +can start to again do that if you've got + + + align:start position:0% +can start to again do that if you've got +two effects or 2 factors you would look + + align:start position:0% +two effects or 2 factors you would look + + + align:start position:0% +two effects or 2 factors you would look +for the question it's there something + + align:start position:0% +for the question it's there something + + + align:start position:0% +for the question it's there something +significant in the a effect in the B + + align:start position:0% +significant in the a effect in the B + + + align:start position:0% +significant in the a effect in the B +effect and in the interaction and then + + align:start position:0% +effect and in the interaction and then + + + align:start position:0% +effect and in the interaction and then +the remaining sum of squared deviations + + align:start position:0% +the remaining sum of squared deviations + + + align:start position:0% +the remaining sum of squared deviations +or the residual gives you your error + + align:start position:0% +or the residual gives you your error + + + align:start position:0% +or the residual gives you your error +estimate that you use in the denominator + + align:start position:0% +estimate that you use in the denominator + + + align:start position:0% +estimate that you use in the denominator +and that's that's how you decompose the + + align:start position:0% +and that's that's how you decompose the + + + align:start position:0% +and that's that's how you decompose the +total observed variations so then you + + align:start position:0% +total observed variations so then you + + + align:start position:0% +total observed variations so then you +can form that into an ANOVA table again + + align:start position:0% +can form that into an ANOVA table again + + + align:start position:0% +can form that into an ANOVA table again +looking at the main effects a and B the + + align:start position:0% +looking at the main effects a and B the + + + align:start position:0% +looking at the main effects a and B the +interaction effect and an estimate of + + align:start position:0% +interaction effect and an estimate of + + + align:start position:0% +interaction effect and an estimate of +the error again we get this little funky + + align:start position:0% +the error again we get this little funky + + + align:start position:0% +the error again we get this little funky +cent sign that's supposed to just be a + + align:start position:0% +cent sign that's supposed to just be a + + + align:start position:0% +cent sign that's supposed to just be a +multiplication that's just a little dot + + align:start position:0% + + + + align:start position:0% + +where again you're forming estimates of + + align:start position:0% +where again you're forming estimates of + + + align:start position:0% +where again you're forming estimates of +the mean squares and then ratios of + + align:start position:0% +the mean squares and then ratios of + + + align:start position:0% +the mean squares and then ratios of +those and then you do your your F test + + align:start position:0% +those and then you do your your F test + + + align:start position:0% +those and then you do your your F test +to see if the F is higher than that so + + align:start position:0% +to see if the F is higher than that so + + + align:start position:0% +to see if the F is higher than that so +this is one way of looking at it in + + align:start position:0% +this is one way of looking at it in + + + align:start position:0% +this is one way of looking at it in +terms of contrast if instead of forming + + align:start position:0% +terms of contrast if instead of forming + + + align:start position:0% +terms of contrast if instead of forming +contrast you had used the regression and + + align:start position:0% +contrast you had used the regression and + + + align:start position:0% +contrast you had used the regression and +come up with regression coefficients + + align:start position:0% + + + + align:start position:0% + +associated with each of each of the + + align:start position:0% +associated with each of each of the + + + align:start position:0% +associated with each of each of the +terms you can similarly form the sum of + + align:start position:0% +terms you can similarly form the sum of + + + align:start position:0% +terms you can similarly form the sum of +squares and the mean squares from that + + align:start position:0% +squares and the mean squares from that + + + align:start position:0% +squares and the mean squares from that +from that perspective and in the + + align:start position:0% +from that perspective and in the + + + align:start position:0% +from that perspective and in the +regression form by the way that that + + align:start position:0% +regression form by the way that that + + + align:start position:0% +regression form by the way that that +turns out nicely because it's also gives + + align:start position:0% +turns out nicely because it's also gives + + + align:start position:0% +turns out nicely because it's also gives +you the chance to not subtract off the + + align:start position:0% +you the chance to not subtract off the + + + align:start position:0% +you the chance to not subtract off the +mean from everything but actually + + align:start position:0% +mean from everything but actually + + + align:start position:0% +mean from everything but actually +estimate whether the mean it may be + + align:start position:0% +estimate whether the mean it may be + + + align:start position:0% +estimate whether the mean it may be +significantly different than than zero + + align:start position:0% +significantly different than than zero + + + align:start position:0% +significantly different than than zero +but it's but it's essentially the same + + align:start position:0% +but it's but it's essentially the same + + + align:start position:0% +but it's but it's essentially the same +thing okay so what I've tried to + + align:start position:0% +thing okay so what I've tried to + + + align:start position:0% +thing okay so what I've tried to +convince you here is that you can use + + align:start position:0% +convince you here is that you can use + + + align:start position:0% +convince you here is that you can use +ANOVA to estimate that's a tool we + + align:start position:0% +ANOVA to estimate that's a tool we + + + align:start position:0% +ANOVA to estimate that's a tool we +already know to estimate whether the + + align:start position:0% +already know to estimate whether the + + + align:start position:0% +already know to estimate whether the +effects are significant or not and + + align:start position:0% +effects are significant or not and + + + align:start position:0% +effects are significant or not and +whether you should include that term in + + align:start position:0% +whether you should include that term in + + + align:start position:0% +whether you should include that term in +your model if you don't have enough + + align:start position:0% +your model if you don't have enough + + + align:start position:0% +your model if you don't have enough +evidence that that value the coefficient + + align:start position:0% +evidence that that value the coefficient + + + align:start position:0% +evidence that that value the coefficient +associated with x1 might be nonzero + + align:start position:0% +associated with x1 might be nonzero + + + align:start position:0% +associated with x1 might be nonzero +you're probably better off not including + + align:start position:0% +you're probably better off not including + + + align:start position:0% +you're probably better off not including +it in your model in which case those any + + align:start position:0% +it in your model in which case those any + + + align:start position:0% +it in your model in which case those any +little squiggles that might be there but + + align:start position:0% +little squiggles that might be there but + + + align:start position:0% +little squiggles that might be there but +you're not confident really are there + + align:start position:0% +you're not confident really are there + + + align:start position:0% +you're not confident really are there +contribute to your error term and you + + align:start position:0% +contribute to your error term and you + + + align:start position:0% +contribute to your error term and you +treat them basically as noise rather + + align:start position:0% +treat them basically as noise rather + + + align:start position:0% +treat them basically as noise rather +than trying to fit them okay so let's + + align:start position:0% +than trying to fit them okay so let's + + + align:start position:0% +than trying to fit them okay so let's +let's try this out for an example this + + align:start position:0% +let's try this out for an example this + + + align:start position:0% +let's try this out for an example this +is one of the sets of data that we + + align:start position:0% +is one of the sets of data that we + + + align:start position:0% +is one of the sets of data that we +looked at very early in the term it's + + align:start position:0% +looked at very early in the term it's + + + align:start position:0% +looked at very early in the term it's +the break forming remember the the press + + align:start position:0% +the break forming remember the the press + + + align:start position:0% +the break forming remember the the press +we have either aluminum or stainless + + align:start position:0% +we have either aluminum or stainless + + + align:start position:0% +we have either aluminum or stainless +steel and we've got sort of an angled + + align:start position:0% +steel and we've got sort of an angled + + + align:start position:0% +steel and we've got sort of an angled +press and we're pressing it down into + + align:start position:0% +press and we're pressing it down into + + + align:start position:0% +press and we're pressing it down into +some depth and trying to bend that that + + align:start position:0% +some depth and trying to bend that that + + + align:start position:0% +some depth and trying to bend that that +piece of sheet metal and that was + + align:start position:0% +piece of sheet metal and that was + + + align:start position:0% +piece of sheet metal and that was +actually a designed experiment in fact + + align:start position:0% +actually a designed experiment in fact + + + align:start position:0% +actually a designed experiment in fact +the two factors that we were looking at + + align:start position:0% +the two factors that we were looking at + + + align:start position:0% +the two factors that we were looking at +here + + align:start position:0% +here + + + align:start position:0% +here +is how deep the punch goes in and what + + align:start position:0% +is how deep the punch goes in and what + + + align:start position:0% +is how deep the punch goes in and what +the material type was either aluminum or + + align:start position:0% +the material type was either aluminum or + + + align:start position:0% +the material type was either aluminum or +steel and this is just identifying the + + align:start position:0% +steel and this is just identifying the + + + align:start position:0% +steel and this is just identifying the +factor levels that I'm going to + + align:start position:0% +factor levels that I'm going to + + + align:start position:0% +factor levels that I'm going to +associate with with these terms now this + + align:start position:0% +associate with with these terms now this + + + align:start position:0% +associate with with these terms now this +is actually an interesting one because + + align:start position:0% +is actually an interesting one because + + + align:start position:0% +is actually an interesting one because +this is a discrete factor level well + + align:start position:0% +this is a discrete factor level well + + + align:start position:0% +this is a discrete factor level well +this is more of a continuous factor + + align:start position:0% +this is more of a continuous factor + + + align:start position:0% +this is more of a continuous factor +level and you know you'll you'll catch a + + align:start position:0% +level and you know you'll you'll catch a + + + align:start position:0% +level and you know you'll you'll catch a +little bit later there's something a + + align:start position:0% +little bit later there's something a + + + align:start position:0% +little bit later there's something a +little bit odd where we talk about the + + align:start position:0% +little bit odd where we talk about the + + + align:start position:0% +little bit odd where we talk about the +zero factor setting between aluminum and + + align:start position:0% +zero factor setting between aluminum and + + + align:start position:0% +zero factor setting between aluminum and +steel that actually doesn't make any + + align:start position:0% +steel that actually doesn't make any + + + align:start position:0% +steel that actually doesn't make any +sense + + align:start position:0% +sense + + + align:start position:0% +sense +but I can talk about perhaps the zero + + align:start position:0% +but I can talk about perhaps the zero + + + align:start position:0% +but I can talk about perhaps the zero +factor setting of zero point four or + + align:start position:0% +factor setting of zero point four or + + + align:start position:0% +factor setting of zero point four or +five inches halfway between the low and + + align:start position:0% +five inches halfway between the low and + + + align:start position:0% +five inches halfway between the low and +the high of a continuous parameter so I + + align:start position:0% +the high of a continuous parameter so I + + + align:start position:0% +the high of a continuous parameter so I +like this because it's mixing or showing + + align:start position:0% +like this because it's mixing or showing + + + align:start position:0% +like this because it's mixing or showing +that the same tools and technology + + align:start position:0% +that the same tools and technology + + + align:start position:0% +that the same tools and technology +mostly work for both discrete decisions + + align:start position:0% +mostly work for both discrete decisions + + + align:start position:0% +mostly work for both discrete decisions +and design of experiments and continuous + + align:start position:0% +and design of experiments and continuous + + + align:start position:0% +and design of experiments and continuous +ones and we'll see where it doesn't a + + align:start position:0% +ones and we'll see where it doesn't a + + + align:start position:0% +ones and we'll see where it doesn't a +little bit letter later so let's try out + + align:start position:0% +little bit letter later so let's try out + + + align:start position:0% +little bit letter later so let's try out +a very simple designed experiment a two + + align:start position:0% +a very simple designed experiment a two + + + align:start position:0% +a very simple designed experiment a two +to the two factor where the final angle + + align:start position:0% +to the two factor where the final angle + + + align:start position:0% +to the two factor where the final angle +after removing the punch is our output + + align:start position:0% +after removing the punch is our output + + + align:start position:0% +after removing the punch is our output +this is the actual data what we've got + + align:start position:0% +this is the actual data what we've got + + + align:start position:0% +this is the actual data what we've got +is for each of the level settings + + align:start position:0% +is for each of the level settings + + + align:start position:0% +is for each of the level settings +we've got replicas so I'm doing ten + + align:start position:0% +we've got replicas so I'm doing ten + + + align:start position:0% +we've got replicas so I'm doing ten +replicates at each at each test setting + + align:start position:0% +replicates at each at each test setting + + + align:start position:0% +replicates at each at each test setting +of the high and low combination for x1 + + align:start position:0% +of the high and low combination for x1 + + + align:start position:0% +of the high and low combination for x1 +and excellent so I've got four different + + align:start position:0% +and excellent so I've got four different + + + align:start position:0% +and excellent so I've got four different +corners four different combinations ten + + align:start position:0% +corners four different combinations ten + + + align:start position:0% +corners four different combinations ten +replicates and and here's the data for + + align:start position:0% +replicates and and here's the data for + + + align:start position:0% +replicates and and here's the data for +that by the way we'll come back to this + + align:start position:0% +that by the way we'll come back to this + + + align:start position:0% +that by the way we'll come back to this +a little bit later but if this is run + + align:start position:0% +a little bit later but if this is run + + + align:start position:0% +a little bit later but if this is run +number and if those are done in time + + align:start position:0% +number and if those are done in time + + + align:start position:0% +number and if those are done in time +there's actually something a little + + align:start position:0% +there's actually something a little + + + align:start position:0% +there's actually something a little +risky in this experimental design what + + align:start position:0% +risky in this experimental design what + + + align:start position:0% +risky in this experimental design what +if this is foreshadowing - coming back + + align:start position:0% +if this is foreshadowing - coming back + + + align:start position:0% +if this is foreshadowing - coming back +to additional issues of nasty things you + + align:start position:0% +to additional issues of nasty things you + + + align:start position:0% +to additional issues of nasty things you +got to keep in mind when you do design + + align:start position:0% +got to keep in mind when you do design + + + align:start position:0% +got to keep in mind when you do design +of experiments but what if there was + + align:start position:0% +of experiments but what if there was + + + align:start position:0% +of experiments but what if there was +some time degradation + + align:start position:0% +some time degradation + + + align:start position:0% +some time degradation +some time we're in the tool the problem + + align:start position:0% +some time we're in the tool the problem + + + align:start position:0% +some time we're in the tool the problem +is you wouldn't really be able to + + align:start position:0% +is you wouldn't really be able to + + + align:start position:0% +is you wouldn't really be able to +distinguish a time effect from a change + + align:start position:0% +distinguish a time effect from a change + + + align:start position:0% +distinguish a time effect from a change +in the factor settings so one approach + + align:start position:0% +in the factor settings so one approach + + + align:start position:0% +in the factor settings so one approach +that you might if you can cheaply do it + + align:start position:0% +that you might if you can cheaply do it + + + align:start position:0% +that you might if you can cheaply do it +here you might actually have got to make + + align:start position:0% +here you might actually have got to make + + + align:start position:0% +here you might actually have got to make +you know maybe some kind of machine + + align:start position:0% +you know maybe some kind of machine + + + align:start position:0% +you know maybe some kind of machine +setup change and you wouldn't want to do + + align:start position:0% +setup change and you wouldn't want to do + + + align:start position:0% +setup change and you wouldn't want to do +this but you might randomize the order + + align:start position:0% +this but you might randomize the order + + + align:start position:0% +this but you might randomize the order +of your runs in time to sort of block + + align:start position:0% +of your runs in time to sort of block + + + align:start position:0% +of your runs in time to sort of block +against the effect of of time and we'll + + align:start position:0% +against the effect of of time and we'll + + + align:start position:0% +against the effect of of time and we'll +come back to that but but here it's a + + align:start position:0% +come back to that but but here it's a + + + align:start position:0% +come back to that but but here it's a +simple I do all of my Lolo combinations + + align:start position:0% +simple I do all of my Lolo combinations + + + align:start position:0% +simple I do all of my Lolo combinations +first then I did my my low high then my + + align:start position:0% +first then I did my my low high then my + + + align:start position:0% +first then I did my my low high then my +high low and my high high okay so that's + + align:start position:0% +high low and my high high okay so that's + + + align:start position:0% +high low and my high high okay so that's +our data now what we're doing here first + + align:start position:0% +our data now what we're doing here first + + + align:start position:0% +our data now what we're doing here first +off is I'm just going to form the mean I + + align:start position:0% +off is I'm just going to form the mean I + + + align:start position:0% +off is I'm just going to form the mean I +take the the mean of those ten points + + align:start position:0% +take the the mean of those ten points + + + align:start position:0% +take the the mean of those ten points +and that's going to be my Y bar at each + + align:start position:0% +and that's going to be my Y bar at each + + + align:start position:0% +and that's going to be my Y bar at each +of my level settings so I'm sort of + + align:start position:0% +of my level settings so I'm sort of + + + align:start position:0% +of my level settings so I'm sort of +reducing it down from the ten replicates + + align:start position:0% +reducing it down from the ten replicates + + + align:start position:0% +reducing it down from the ten replicates +down to four means so this is my mean at + + align:start position:0% +down to four means so this is my mean at + + + align:start position:0% +down to four means so this is my mean at +each of those four different conditions + + align:start position:0% +each of those four different conditions + + + align:start position:0% +each of those four different conditions +and now I have my my output my Y vector + + align:start position:0% +and now I have my my output my Y vector + + + align:start position:0% +and now I have my my output my Y vector +setting up for a regression as being the + + align:start position:0% +setting up for a regression as being the + + + align:start position:0% +setting up for a regression as being the +observed means what's my X matrix + + align:start position:0% +observed means what's my X matrix + + + align:start position:0% +observed means what's my X matrix +setting up for my my regression oops + + align:start position:0% +setting up for my my regression oops + + + align:start position:0% +setting up for my my regression oops +it's just it's it's based on the level + + align:start position:0% +it's just it's it's based on the level + + + align:start position:0% +it's just it's it's based on the level +settings but notice we also add in that + + align:start position:0% +settings but notice we also add in that + + + align:start position:0% +settings but notice we also add in that +one factor that one factor is basically + + align:start position:0% +one factor that one factor is basically + + + align:start position:0% +one factor that one factor is basically +giving us when I multiply out my matrix + + align:start position:0% +giving us when I multiply out my matrix + + + align:start position:0% +giving us when I multiply out my matrix +that's corresponding to my beta not my + + align:start position:0% +that's corresponding to my beta not my + + + align:start position:0% +that's corresponding to my beta not my +overall mean so that what that's going + + align:start position:0% +overall mean so that what that's going + + + align:start position:0% +overall mean so that what that's going +to do is be able to to sort of add all + + align:start position:0% +to do is be able to to sort of add all + + + align:start position:0% +to do is be able to to sort of add all +of those up divided by four and give me + + align:start position:0% +of those up divided by four and give me + + + align:start position:0% +of those up divided by four and give me +an estimate of the overall grand mean of + + align:start position:0% +an estimate of the overall grand mean of + + + align:start position:0% +an estimate of the overall grand mean of +my output okay + + align:start position:0% +my output okay + + + align:start position:0% +my output okay +and we also create the x1 x2 cross + + align:start position:0% +and we also create the x1 x2 cross + + + align:start position:0% +and we also create the x1 x2 cross +factor + + align:start position:0% +factor + + + align:start position:0% +factor +in order to be able to estimate an + + align:start position:0% +in order to be able to estimate an + + + align:start position:0% +in order to be able to estimate an +interaction term so overall then this + + align:start position:0% +interaction term so overall then this + + + align:start position:0% +interaction term so overall then this +here is my my X matrix I can then solve + + align:start position:0% +here is my my X matrix I can then solve + + + align:start position:0% +here is my my X matrix I can then solve +it now notice we're using the direct + + align:start position:0% +it now notice we're using the direct + + + align:start position:0% +it now notice we're using the direct +inverse and not the pseudo inverse y + + align:start position:0% + + + + align:start position:0% + +remember ultimately we've got you know y + + align:start position:0% +remember ultimately we've got you know y + + + align:start position:0% +remember ultimately we've got you know y +equals B beta X that's the model we're + + align:start position:0% +equals B beta X that's the model we're + + + align:start position:0% +equals B beta X that's the model we're +trying to form a beta naught plus beta 1 + + align:start position:0% +trying to form a beta naught plus beta 1 + + + align:start position:0% +trying to form a beta naught plus beta 1 +beta 2 plus an interaction term in this + + align:start position:0% +beta 2 plus an interaction term in this + + + align:start position:0% +beta 2 plus an interaction term in this +approach how many data points do I have + + align:start position:0% + + + + align:start position:0% + +fitting into this regression my Y vector + + align:start position:0% +fitting into this regression my Y vector + + + align:start position:0% +fitting into this regression my Y vector +was four data points because it was just + + align:start position:0% +was four data points because it was just + + + align:start position:0% +was four data points because it was just +the means right + + align:start position:0% +the means right + + + align:start position:0% +the means right +how many coefficients for I can exactly + + align:start position:0% +how many coefficients for I can exactly + + + align:start position:0% +how many coefficients for I can exactly +fit my four coefficients and that's why + + align:start position:0% +fit my four coefficients and that's why + + + align:start position:0% +fit my four coefficients and that's why +I can do the direct inverse and when I + + align:start position:0% +I can do the direct inverse and when I + + + align:start position:0% +I can do the direct inverse and when I +do that it directly pops out these + + align:start position:0% +do that it directly pops out these + + + align:start position:0% +do that it directly pops out these +values from my beta coefficients which + + align:start position:0% +values from my beta coefficients which + + + align:start position:0% +values from my beta coefficients which +feed or give me my regression model + + align:start position:0% +feed or give me my regression model + + + align:start position:0% +feed or give me my regression model +what's Epsilon in this model 0 its 0 I + + align:start position:0% +what's Epsilon in this model 0 its 0 I + + + align:start position:0% +what's Epsilon in this model 0 its 0 I +exactly fit my four data points with + + align:start position:0% +exactly fit my four data points with + + + align:start position:0% +exactly fit my four data points with +with my 4 coefficients I don't even have + + align:start position:0% +with my 4 coefficients I don't even have + + + align:start position:0% +with my 4 coefficients I don't even have +any extra data to estimate Epsilon if I + + align:start position:0% +any extra data to estimate Epsilon if I + + + align:start position:0% +any extra data to estimate Epsilon if I +just use the mean values however if I go + + align:start position:0% +just use the mean values however if I go + + + align:start position:0% +just use the mean values however if I go +back and expand out realize I had 10 + + align:start position:0% +back and expand out realize I had 10 + + + align:start position:0% +back and expand out realize I had 10 +replicates at each of those main values + + align:start position:0% +replicates at each of those main values + + + align:start position:0% +replicates at each of those main values +that's one form a one one source of + + align:start position:0% +that's one form a one one source of + + + align:start position:0% +that's one form a one one source of +information about pure replication error + + align:start position:0% +information about pure replication error + + + align:start position:0% +information about pure replication error +that is to say noise factors in in the + + align:start position:0% +that is to say noise factors in in the + + + align:start position:0% +that is to say noise factors in in the +data so in this approach where I just + + align:start position:0% +data so in this approach where I just + + + align:start position:0% +data so in this approach where I just +used the mean and the regression I don't + + align:start position:0% +used the mean and the regression I don't + + + align:start position:0% +used the mean and the regression I don't +have an estimate for Epsilon I would + + align:start position:0% +have an estimate for Epsilon I would + + + align:start position:0% +have an estimate for Epsilon I would +have to look back and form a separate + + align:start position:0% +have to look back and form a separate + + + align:start position:0% +have to look back and form a separate +pool the estimate across my four + + align:start position:0% +pool the estimate across my four + + + align:start position:0% +pool the estimate across my four +experimental data points for for the + + align:start position:0% +experimental data points for for the + + + align:start position:0% +experimental data points for for the +noise variance in the in the system okay + + align:start position:0% +noise variance in the in the system okay + + + align:start position:0% +noise variance in the in the system okay +let's see + + align:start position:0% + + + + align:start position:0% + +now I thought I had another example okay + + align:start position:0% +now I thought I had another example okay + + + align:start position:0% +now I thought I had another example okay +we'll come back to that so once I've got + + align:start position:0% +we'll come back to that so once I've got + + + align:start position:0% +we'll come back to that so once I've got +the model this is essentially the model + + align:start position:0% +the model this is essentially the model + + + align:start position:0% +the model this is essentially the model +that I have of the true underlying + + align:start position:0% +that I have of the true underlying + + + align:start position:0% +that I have of the true underlying +process again first-order linear plus an + + align:start position:0% +process again first-order linear plus an + + + align:start position:0% +process again first-order linear plus an +interaction plus maybe I have lingering + + align:start position:0% +interaction plus maybe I have lingering + + + align:start position:0% +interaction plus maybe I have lingering +in my head there might still be some + + align:start position:0% +in my head there might still be some + + + align:start position:0% +in my head there might still be some +higher-order quadratic dependence for + + align:start position:0% +higher-order quadratic dependence for + + + align:start position:0% +higher-order quadratic dependence for +example I'm punched out I haven't really + + align:start position:0% +example I'm punched out I haven't really + + + align:start position:0% +example I'm punched out I haven't really +sampled enough to be able to estimate + + align:start position:0% +sampled enough to be able to estimate + + + align:start position:0% +sampled enough to be able to estimate +that and I also have some noise the + + align:start position:0% +that and I also have some noise the + + + align:start position:0% +that and I also have some noise the +model that I have fit right here my Y + + align:start position:0% +model that I have fit right here my Y + + + align:start position:0% +model that I have fit right here my Y +hat estimate includes estimates I guess + + align:start position:0% +hat estimate includes estimates I guess + + + align:start position:0% +hat estimate includes estimates I guess +I should say estimates here for for + + align:start position:0% +I should say estimates here for for + + + align:start position:0% +I should say estimates here for for +these different terms and what we're + + align:start position:0% +these different terms and what we're + + + align:start position:0% +these different terms and what we're +basically saying is we're lumping in + + align:start position:0% +basically saying is we're lumping in + + + align:start position:0% +basically saying is we're lumping in +together + + align:start position:0% +together + + + align:start position:0% +together +all of the errors that might be lurking + + align:start position:0% +all of the errors that might be lurking + + + align:start position:0% +all of the errors that might be lurking +as two effects together one is random + + align:start position:0% +as two effects together one is random + + + align:start position:0% +as two effects together one is random +noise the other is neglected higher + + align:start position:0% +noise the other is neglected higher + + + align:start position:0% +noise the other is neglected higher +order terms + + align:start position:0% +order terms + + + align:start position:0% +order terms +remember these are that's kind of our + + align:start position:0% +remember these are that's kind of our + + + align:start position:0% +remember these are that's kind of our +acronym for higher order terms okay + + align:start position:0% +acronym for higher order terms okay + + + align:start position:0% +acronym for higher order terms okay +question right so what you so the + + align:start position:0% +question right so what you so the + + + align:start position:0% +question right so what you so the +question was what if you add additional + + align:start position:0% +question was what if you add additional + + + align:start position:0% +question was what if you add additional +higher order terms to drive epsilon to + + align:start position:0% +higher order terms to drive epsilon to + + + align:start position:0% +higher order terms to drive epsilon to +zero this is a very good point because + + align:start position:0% +zero this is a very good point because + + + align:start position:0% +zero this is a very good point because +if I don't have any replicates I could + + align:start position:0% +if I don't have any replicates I could + + + align:start position:0% +if I don't have any replicates I could +always add model terms until I finally + + align:start position:0% +always add model terms until I finally + + + align:start position:0% +always add model terms until I finally +get to where I have a perfect fit right + + align:start position:0% +get to where I have a perfect fit right + + + align:start position:0% +get to where I have a perfect fit right +just like we saw with the four data + + align:start position:0% +just like we saw with the four data + + + align:start position:0% +just like we saw with the four data +points and forth in which case my + + align:start position:0% +points and forth in which case my + + + align:start position:0% +points and forth in which case my +residual then is zero but I've added + + align:start position:0% +residual then is zero but I've added + + + align:start position:0% +residual then is zero but I've added +model terms but I also have no way in + + align:start position:0% +model terms but I also have no way in + + + align:start position:0% +model terms but I also have no way in +that case of knowing whether the model + + align:start position:0% +that case of knowing whether the model + + + align:start position:0% +that case of knowing whether the model +terms are significant or not if I have + + align:start position:0% +terms are significant or not if I have + + + align:start position:0% +terms are significant or not if I have +replicates on the other hand then you + + align:start position:0% +replicates on the other hand then you + + + align:start position:0% +replicates on the other hand then you +will almost never if there's any noise + + align:start position:0% +will almost never if there's any noise + + + align:start position:0% +will almost never if there's any noise +in the replicants where the replicates + + align:start position:0% +in the replicants where the replicates + + + align:start position:0% +in the replicants where the replicates +do not lie exactly on top of each other + + align:start position:0% +do not lie exactly on top of each other + + + align:start position:0% +do not lie exactly on top of each other +for every rerun at the same + + align:start position:0% +for every rerun at the same + + + align:start position:0% +for every rerun at the same +then there's no way to drive the + + align:start position:0% +then there's no way to drive the + + + align:start position:0% +then there's no way to drive the +residual to zero because I will have + + align:start position:0% +residual to zero because I will have + + + align:start position:0% +residual to zero because I will have +pure process error at least even if I've + + align:start position:0% +pure process error at least even if I've + + + align:start position:0% +pure process error at least even if I've +added all the model terms I need to + + align:start position:0% +added all the model terms I need to + + + align:start position:0% +added all the model terms I need to +drive model error phot to zero so we've + + align:start position:0% +drive model error phot to zero so we've + + + align:start position:0% +drive model error phot to zero so we've +got actually these two things going on + + align:start position:0% +got actually these two things going on + + + align:start position:0% +got actually these two things going on +we've got two key sources of residuals + + align:start position:0% +we've got two key sources of residuals + + + align:start position:0% +we've got two key sources of residuals +lack of lack of perfection in our model + + align:start position:0% +lack of lack of perfection in our model + + + align:start position:0% +lack of lack of perfection in our model +that we want to talk about how we + + align:start position:0% +that we want to talk about how we + + + align:start position:0% +that we want to talk about how we +distinguish and detect because one of + + align:start position:0% +distinguish and detect because one of + + + align:start position:0% +distinguish and detect because one of +those is letting whether we have an + + align:start position:0% +those is letting whether we have an + + + align:start position:0% +those is letting whether we have an +adequate model form do I have the right + + align:start position:0% +adequate model form do I have the right + + + align:start position:0% +adequate model form do I have the right +terms and enough of the terms in there + + align:start position:0% +terms and enough of the terms in there + + + align:start position:0% +terms and enough of the terms in there +or is there just replication variance + + align:start position:0% +or is there just replication variance + + + align:start position:0% +or is there just replication variance +noise which I can't fit all I can do is + + align:start position:0% +noise which I can't fit all I can do is + + + align:start position:0% +noise which I can't fit all I can do is +estimate the Sigma associated with that + + align:start position:0% +estimate the Sigma associated with that + + + align:start position:0% +estimate the Sigma associated with that +replica noise okay that's the key + + align:start position:0% +replica noise okay that's the key + + + align:start position:0% +replica noise okay that's the key +question that we that we want to to get + + align:start position:0% +question that we that we want to to get + + + align:start position:0% +question that we that we want to to get +to before we get to breaking down the + + align:start position:0% +to before we get to breaking down the + + + align:start position:0% +to before we get to breaking down the +residuals one thing that you should + + align:start position:0% +residuals one thing that you should + + + align:start position:0% +residuals one thing that you should +always do after you fit your model is + + align:start position:0% +always do after you fit your model is + + + align:start position:0% +always do after you fit your model is +actually look at the residuals to see if + + align:start position:0% +actually look at the residuals to see if + + + align:start position:0% +actually look at the residuals to see if +there are trends qualitatively that may + + align:start position:0% +there are trends qualitatively that may + + + align:start position:0% +there are trends qualitatively that may +be missing because that will often give + + align:start position:0% +be missing because that will often give + + + align:start position:0% +be missing because that will often give +you a lot of insight into whether it's a + + align:start position:0% +you a lot of insight into whether it's a + + + align:start position:0% +you a lot of insight into whether it's a +model model structure problem or not and + + align:start position:0% +model model structure problem or not and + + + align:start position:0% +model model structure problem or not and +so for this data what we've actually + + align:start position:0% +so for this data what we've actually + + + align:start position:0% +so for this data what we've actually +done here is look at the residuals + + align:start position:0% +done here is look at the residuals + + + align:start position:0% +done here is look at the residuals +associated with the ten replicates that + + align:start position:0% +associated with the ten replicates that + + + align:start position:0% +associated with the ten replicates that +we've got and what you'll see is first + + align:start position:0% +we've got and what you'll see is first + + + align:start position:0% +we've got and what you'll see is first +off the mean of your residuals had + + align:start position:0% +off the mean of your residuals had + + + align:start position:0% +off the mean of your residuals had +better be zero otherwise you've actually + + align:start position:0% +better be zero otherwise you've actually + + + align:start position:0% +better be zero otherwise you've actually +got a screw-up somewhere in your fit + + align:start position:0% +got a screw-up somewhere in your fit + + + align:start position:0% +got a screw-up somewhere in your fit +just mechanically right but what you + + align:start position:0% +just mechanically right but what you + + + align:start position:0% +just mechanically right but what you +would like to see is essentially the + + align:start position:0% +would like to see is essentially the + + + align:start position:0% +would like to see is essentially the +residuals ought to not depend on the + + align:start position:0% +residuals ought to not depend on the + + + align:start position:0% +residuals ought to not depend on the +level setting or the or the experimental + + align:start position:0% +level setting or the or the experimental + + + align:start position:0% +level setting or the or the experimental +data point especially with continuous + + align:start position:0% +data point especially with continuous + + + align:start position:0% +data point especially with continuous +parameters if what you see is the + + align:start position:0% +parameters if what you see is the + + + align:start position:0% +parameters if what you see is the +residuals versus mall values are very + + align:start position:0% +residuals versus mall values are very + + + align:start position:0% +residuals versus mall values are very +tiny and the residuals for big values + + align:start position:0% +tiny and the residuals for big values + + + align:start position:0% +tiny and the residuals for big values +are really really large that actually + + align:start position:0% +are really really large that actually + + + align:start position:0% +are really really large that actually +violates some of the + + align:start position:0% +violates some of the + + + align:start position:0% +violates some of the +we've made in in the model fitting and + + align:start position:0% +we've made in in the model fitting and + + + align:start position:0% +we've made in in the model fitting and +you might need to go and do a + + align:start position:0% +you might need to go and do a + + + align:start position:0% +you might need to go and do a +transformation of your data perhaps + + align:start position:0% +transformation of your data perhaps + + + align:start position:0% +transformation of your data perhaps +something like a logarithmic + + align:start position:0% +something like a logarithmic + + + align:start position:0% +something like a logarithmic +transformation or some other + + align:start position:0% +transformation or some other + + + align:start position:0% +transformation or some other +transformation of your Y output data + + align:start position:0% +transformation of your Y output data + + + align:start position:0% +transformation of your Y output data +because your residuals are not all in 0 + + align:start position:0% +because your residuals are not all in 0 + + + align:start position:0% +because your residuals are not all in 0 +Sigma squared as we assume the same + + align:start position:0% +Sigma squared as we assume the same + + + align:start position:0% +Sigma squared as we assume the same +variance for each of your data points + + align:start position:0% +variance for each of your data points + + + align:start position:0% +variance for each of your data points +question + + align:start position:0% + + + + align:start position:0% + +yes yes oh so the the question for folks + + align:start position:0% +yes yes oh so the the question for folks + + + align:start position:0% +yes yes oh so the the question for folks +in Singapore may not have heard that was + + align:start position:0% +in Singapore may not have heard that was + + + align:start position:0% +in Singapore may not have heard that was +was all right aren't there other + + align:start position:0% +was all right aren't there other + + + align:start position:0% +was all right aren't there other +possible sources of residual or error + + align:start position:0% +possible sources of residual or error + + + align:start position:0% +possible sources of residual or error +including for example other factors like + + align:start position:0% +including for example other factors like + + + align:start position:0% +including for example other factors like +an x3 factor that we didn't even + + align:start position:0% +an x3 factor that we didn't even + + + align:start position:0% +an x3 factor that we didn't even +consider is working underneath and + + align:start position:0% +consider is working underneath and + + + align:start position:0% +consider is working underneath and +that's absolutely true those are all + + align:start position:0% +that's absolutely true those are all + + + align:start position:0% +that's absolutely true those are all +potential additional sources of I guess + + align:start position:0% +potential additional sources of I guess + + + align:start position:0% +potential additional sources of I guess +you could look at it it's either model + + align:start position:0% +you could look at it it's either model + + + align:start position:0% +you could look at it it's either model +error or noise what we're doing is + + align:start position:0% +error or noise what we're doing is + + + align:start position:0% +error or noise what we're doing is +treating it all as noise and we'll talk + + align:start position:0% +treating it all as noise and we'll talk + + + align:start position:0% +treating it all as noise and we'll talk +a little bit more about nuisance factors + + align:start position:0% +a little bit more about nuisance factors + + + align:start position:0% +a little bit more about nuisance factors +and how we might walk against that but + + align:start position:0% +and how we might walk against that but + + + align:start position:0% +and how we might walk against that but +essentially we're lumping all of those + + align:start position:0% +essentially we're lumping all of those + + + align:start position:0% +essentially we're lumping all of those +things into just the Sigma squared + + align:start position:0% +things into just the Sigma squared + + + align:start position:0% +things into just the Sigma squared +unless we're explicitly breaking them + + align:start position:0% +unless we're explicitly breaking them + + + align:start position:0% +unless we're explicitly breaking them +out and treating them in our model yes + + align:start position:0% + + + + align:start position:0% + +yes okay so you did essentially the + + align:start position:0% +yes okay so you did essentially the + + + align:start position:0% +yes okay so you did essentially the +special case where if you believe really + + align:start position:0% +special case where if you believe really + + + align:start position:0% +special case where if you believe really +the higher order term or even the + + align:start position:0% +the higher order term or even the + + + align:start position:0% +the higher order term or even the +interaction term in our two-by-two let's + + align:start position:0% +interaction term in our two-by-two let's + + + align:start position:0% +interaction term in our two-by-two let's +say I really believe that really is not + + align:start position:0% +say I really believe that really is not + + + align:start position:0% +say I really believe that really is not +any reason for there to be an a/b + + align:start position:0% +any reason for there to be an a/b + + + align:start position:0% +any reason for there to be an a/b +interaction you can use that as + + align:start position:0% +interaction you can use that as + + + align:start position:0% +interaction you can use that as +essentially a replicate and not include + + align:start position:0% +essentially a replicate and not include + + + align:start position:0% +essentially a replicate and not include +that in the model term in which case + + align:start position:0% +that in the model term in which case + + + align:start position:0% +that in the model term in which case +then I've got four data points three + + align:start position:0% +then I've got four data points three + + + align:start position:0% +then I've got four data points three +model terms theta naught beta 1 beta 2 + + align:start position:0% +model terms theta naught beta 1 beta 2 + + + align:start position:0% +model terms theta naught beta 1 beta 2 +and I've got the barest bones of + + align:start position:0% +and I've got the barest bones of + + + align:start position:0% +and I've got the barest bones of +additional data to be able to form an + + align:start position:0% +additional data to be able to form an + + + align:start position:0% +additional data to be able to form an +error estimate so it's basically + + align:start position:0% +error estimate so it's basically + + + align:start position:0% +error estimate so it's basically +treating the interaction as noise + + align:start position:0% +treating the interaction as noise + + + align:start position:0% +treating the interaction as noise +because I don't think that it's real and + + align:start position:0% +because I don't think that it's real and + + + align:start position:0% +because I don't think that it's real and +then you can do you've got just enough + + align:start position:0% +then you can do you've got just enough + + + align:start position:0% +then you can do you've got just enough +to be able to at least ask minimal + + align:start position:0% +to be able to at least ask minimal + + + align:start position:0% +to be able to at least ask minimal +questions about significance one last + + align:start position:0% +questions about significance one last + + + align:start position:0% +questions about significance one last +thing that we always want to do with our + + align:start position:0% +thing that we always want to do with our + + + align:start position:0% +thing that we always want to do with our +residuals is do a quick test or check to + + align:start position:0% +residuals is do a quick test or check to + + + align:start position:0% +residuals is do a quick test or check to +see is it reasonable that to think that + + align:start position:0% +see is it reasonable that to think that + + + align:start position:0% +see is it reasonable that to think that +these things are normally distributed so + + align:start position:0% +these things are normally distributed so + + + align:start position:0% +these things are normally distributed so +you can you know again do a QQ plot and + + align:start position:0% +you can you know again do a QQ plot and + + + align:start position:0% +you can you know again do a QQ plot and +see if there's strong evidence of + + align:start position:0% +see if there's strong evidence of + + + align:start position:0% +see if there's strong evidence of +something strange going on now I said + + align:start position:0% +something strange going on now I said + + + align:start position:0% +something strange going on now I said +here we kind of had to do if I if I used + + align:start position:0% +here we kind of had to do if I if I used + + + align:start position:0% +here we kind of had to do if I if I used +my Y average as my output I can do the + + align:start position:0% +my Y average as my output I can do the + + + align:start position:0% +my Y average as my output I can do the +regression and solve directly you could + + align:start position:0% +regression and solve directly you could + + + align:start position:0% +regression and solve directly you could +also formulate the regression problem + + align:start position:0% +also formulate the regression problem + + + align:start position:0% +also formulate the regression problem +using all of the data and not pre + + align:start position:0% +using all of the data and not pre + + + align:start position:0% +using all of the data and not pre +calculating the average for each of my + + align:start position:0% +calculating the average for each of my + + + align:start position:0% +calculating the average for each of my +four settings in which case we set up + + align:start position:0% +four settings in which case we set up + + + align:start position:0% +four settings in which case we set up +our data a little bit larger I still + + align:start position:0% +our data a little bit larger I still + + + align:start position:0% +our data a little bit larger I still +have my I don't know why it became in + + align:start position:0% +have my I don't know why it became in + + + align:start position:0% +have my I don't know why it became in +the ADA + + align:start position:0% +the ADA + + + align:start position:0% +the ADA +I guess there's my ADA that's still a Y + + align:start position:0% +I guess there's my ADA that's still a Y + + + align:start position:0% +I guess there's my ADA that's still a Y +this is my Y data I still have my X + + align:start position:0% +this is my Y data I still have my X + + + align:start position:0% +this is my Y data I still have my X +which has my main effects and my + + align:start position:0% +which has my main effects and my + + + align:start position:0% +which has my main effects and my +interaction but now each of the + + align:start position:0% +interaction but now each of the + + + align:start position:0% +interaction but now each of the +replicates for example I don't know if + + align:start position:0% +replicates for example I don't know if + + + align:start position:0% +replicates for example I don't know if +you can see it but this is a one one one + + align:start position:0% +you can see it but this is a one one one + + + align:start position:0% +you can see it but this is a one one one +setting and that's one of those outputs + + align:start position:0% +setting and that's one of those outputs + + + align:start position:0% +setting and that's one of those outputs +here's another one one one and the + + align:start position:0% +here's another one one one and the + + + align:start position:0% +here's another one one one and the +output for that particular run in other + + align:start position:0% +output for that particular run in other + + + align:start position:0% +output for that particular run in other +words I have multiple rows in my data I + + align:start position:0% +words I have multiple rows in my data I + + + align:start position:0% +words I have multiple rows in my data I +have ten rows with the same factor + + align:start position:0% +have ten rows with the same factor + + + align:start position:0% +have ten rows with the same factor +settings + + align:start position:0% +settings + + + align:start position:0% +settings +and each one of which has a different + + align:start position:0% +and each one of which has a different + + + align:start position:0% +and each one of which has a different +output Y and now I can set up and do my + + align:start position:0% +output Y and now I can set up and do my + + + align:start position:0% +output Y and now I can set up and do my +regression now I have to use the + + align:start position:0% +regression now I have to use the + + + align:start position:0% +regression now I have to use the +pseudo-inverse + + align:start position:0% +pseudo-inverse + + + align:start position:0% +pseudo-inverse +right because I've got more data than + + align:start position:0% +right because I've got more data than + + + align:start position:0% +right because I've got more data than +I've got coefficients so I'm doing my + + align:start position:0% +I've got coefficients so I'm doing my + + + align:start position:0% +I've got coefficients so I'm doing my +least squares fitting using my pseudo + + align:start position:0% +least squares fitting using my pseudo + + + align:start position:0% +least squares fitting using my pseudo +inverse and what pops out if you + + align:start position:0% +inverse and what pops out if you + + + align:start position:0% +inverse and what pops out if you +actually do that with this data is + + align:start position:0% +actually do that with this data is + + + align:start position:0% +actually do that with this data is +exactly the same beta thank God right + + align:start position:0% +exactly the same beta thank God right + + + align:start position:0% +exactly the same beta thank God right +okay so it's the same estimates of beta + + align:start position:0% +okay so it's the same estimates of beta + + + align:start position:0% +okay so it's the same estimates of beta +as as before now you might also have + + align:start position:0% +as as before now you might also have + + + align:start position:0% +as as before now you might also have +directly a residual based on the + + align:start position:0% +directly a residual based on the + + + align:start position:0% +directly a residual based on the +difference between your predicted Y your + + align:start position:0% +difference between your predicted Y your + + + align:start position:0% +difference between your predicted Y your +Y hat and your actual measured I've got + + align:start position:0% +Y hat and your actual measured I've got + + + align:start position:0% +Y hat and your actual measured I've got +four I've got 40 of those values and I + + align:start position:0% +four I've got 40 of those values and I + + + align:start position:0% +four I've got 40 of those values and I +can use that as my overall estimate for + + align:start position:0% +can use that as my overall estimate for + + + align:start position:0% +can use that as my overall estimate for +my overall residual in that in this case + + align:start position:0% +my overall residual in that in this case + + + align:start position:0% +my overall residual in that in this case +so it sort of pops right out as well and + + align:start position:0% +so it sort of pops right out as well and + + + align:start position:0% +so it sort of pops right out as well and +you can form the same residual so if you + + align:start position:0% +you can form the same residual so if you + + + align:start position:0% +you can form the same residual so if you +actually plot this for the response + + align:start position:0% +actually plot this for the response + + + align:start position:0% +actually plot this for the response +surface for a very simple linear model + + align:start position:0% +surface for a very simple linear model + + + align:start position:0% +surface for a very simple linear model +with interaction this is what you see as + + align:start position:0% +with interaction this is what you see as + + + align:start position:0% +with interaction this is what you see as +you change the material access from your + + align:start position:0% +you change the material access from your + + + align:start position:0% +you change the material access from your +high to low and your depth axis you've + + align:start position:0% +high to low and your depth axis you've + + + align:start position:0% +high to low and your depth axis you've +got kind of this looks like mostly a + + align:start position:0% +got kind of this looks like mostly a + + + align:start position:0% +got kind of this looks like mostly a +slanted plane kind of kind of effect + + align:start position:0% +slanted plane kind of kind of effect + + + align:start position:0% +slanted plane kind of kind of effect +notice that so let me ask you do you + + align:start position:0% +notice that so let me ask you do you + + + align:start position:0% +notice that so let me ask you do you +think there is a significant at the pot + + align:start position:0% +think there is a significant at the pot + + + align:start position:0% +think there is a significant at the pot +do you think there's a significant + + align:start position:0% +do you think there's a significant + + + align:start position:0% +do you think there's a significant +effect from factor X one significant + + align:start position:0% +effect from factor X one significant + + + align:start position:0% +effect from factor X one significant +effect from factor X two + + align:start position:0% + + + + align:start position:0% + +I see some head shaking it looks like + + align:start position:0% +I see some head shaking it looks like + + + align:start position:0% +I see some head shaking it looks like +it's a nice trend there's lots of + + align:start position:0% +it's a nice trend there's lots of + + + align:start position:0% +it's a nice trend there's lots of +movement in the output values sure why + + align:start position:0% +movement in the output values sure why + + + align:start position:0% +movement in the output values sure why +not + + align:start position:0% +not + + + align:start position:0% +not +just looking at this plot I argue you + + align:start position:0% +just looking at this plot I argue you + + + align:start position:0% +just looking at this plot I argue you +can't tell this is just your best fit + + align:start position:0% +can't tell this is just your best fit + + + align:start position:0% +can't tell this is just your best fit +based on your betas but you don't + + align:start position:0% +based on your betas but you don't + + + align:start position:0% +based on your betas but you don't +actually know whether they're + + align:start position:0% +actually know whether they're + + + align:start position:0% +actually know whether they're +significant or not just plotting the + + align:start position:0% +significant or not just plotting the + + + align:start position:0% +significant or not just plotting the +output of your model here's why for + + align:start position:0% +output of your model here's why for + + + align:start position:0% +output of your model here's why for +example if I were to tell you okay at + + align:start position:0% +example if I were to tell you okay at + + + align:start position:0% +example if I were to tell you okay at +this combination of depth and material + + align:start position:0% +this combination of depth and material + + + align:start position:0% +this combination of depth and material +at the plus one plus one + + align:start position:0% +at the plus one plus one + + + align:start position:0% +at the plus one plus one +I actually plotted the 10 different + + align:start position:0% +I actually plotted the 10 different + + + align:start position:0% +I actually plotted the 10 different +values you saw and they all looked like + + align:start position:0% +values you saw and they all looked like + + + align:start position:0% +values you saw and they all looked like +like this and if I plotted the low-low + + align:start position:0% +like this and if I plotted the low-low + + + align:start position:0% +like this and if I plotted the low-low +and they all look like this now you'd + + align:start position:0% +and they all look like this now you'd + + + align:start position:0% +and they all look like this now you'd +start to say yeah my mom will output + + align:start position:0% +start to say yeah my mom will output + + + align:start position:0% +start to say yeah my mom will output +you know there's big separation between + + align:start position:0% +you know there's big separation between + + + align:start position:0% +you know there's big separation between +those two I think that's significant on + + align:start position:0% +those two I think that's significant on + + + align:start position:0% +those two I think that's significant on +the other hand if I plotted and showed + + align:start position:0% +the other hand if I plotted and showed + + + align:start position:0% +the other hand if I plotted and showed +you a scatter around here that was huge + + align:start position:0% +you a scatter around here that was huge + + + align:start position:0% +you a scatter around here that was huge +and a scatter of your actual data points + + align:start position:0% +and a scatter of your actual data points + + + align:start position:0% +and a scatter of your actual data points +around this condition that was also huge + + align:start position:0% +around this condition that was also huge + + + align:start position:0% +around this condition that was also huge +and there was big overlap between the + + align:start position:0% +and there was big overlap between the + + + align:start position:0% +and there was big overlap between the +two now you'd be a little more leery + + align:start position:0% +two now you'd be a little more leery + + + align:start position:0% +two now you'd be a little more leery +right you'd say well that was my best + + align:start position:0% +right you'd say well that was my best + + + align:start position:0% +right you'd say well that was my best +fit but I'm not sure they're they're + + align:start position:0% +fit but I'm not sure they're they're + + + align:start position:0% +fit but I'm not sure they're they're +actually significant so this highlights + + align:start position:0% +actually significant so this highlights + + + align:start position:0% +actually significant so this highlights +again you've got to use the ANOVA as + + align:start position:0% +again you've got to use the ANOVA as + + + align:start position:0% +again you've got to use the ANOVA as +well to be able to decide is there + + align:start position:0% +well to be able to decide is there + + + align:start position:0% +well to be able to decide is there +actually significance to the model + + align:start position:0% +actually significance to the model + + + align:start position:0% +actually significance to the model +coefficient that we were looking at it's + + align:start position:0% +coefficient that we were looking at it's + + + align:start position:0% +coefficient that we were looking at it's +just another another picture this is + + align:start position:0% +just another another picture this is + + + align:start position:0% +just another another picture this is +looking a little bit at the side this is + + align:start position:0% +looking a little bit at the side this is + + + align:start position:0% +looking a little bit at the side this is +pointing out if I believe that the terms + + align:start position:0% +pointing out if I believe that the terms + + + align:start position:0% +pointing out if I believe that the terms +are significant you could sort of ask + + align:start position:0% +are significant you could sort of ask + + + align:start position:0% +are significant you could sort of ask +the question is there an interaction + + align:start position:0% +the question is there an interaction + + + align:start position:0% +the question is there an interaction +effect it looks like there's not quite + + align:start position:0% +effect it looks like there's not quite + + + align:start position:0% +effect it looks like there's not quite +parallelism between these two lines + + align:start position:0% +parallelism between these two lines + + + align:start position:0% +parallelism between these two lines +there may be an AV interaction but I'd + + align:start position:0% +there may be an AV interaction but I'd + + + align:start position:0% +there may be an AV interaction but I'd +also need to ask the question about + + align:start position:0% +also need to ask the question about + + + align:start position:0% +also need to ask the question about +significance on that so that's the key + + align:start position:0% +significance on that so that's the key + + + align:start position:0% +significance on that so that's the key +question the effects of these terms are + + align:start position:0% +question the effects of these terms are + + + align:start position:0% +question the effects of these terms are +they significant or not + + align:start position:0% +they significant or not + + + align:start position:0% +they significant or not +we would do the ANOVA analysis by the + + align:start position:0% +we would do the ANOVA analysis by the + + + align:start position:0% +we would do the ANOVA analysis by the +way the ANOVA and the t-test + + align:start position:0% +way the ANOVA and the t-test + + + align:start position:0% +way the ANOVA and the t-test +it's almost the same in fact I think + + align:start position:0% +it's almost the same in fact I think + + + align:start position:0% +it's almost the same in fact I think +another problem on the problem set is + + align:start position:0% +another problem on the problem set is + + + align:start position:0% +another problem on the problem set is +understanding a little bit the + + align:start position:0% +understanding a little bit the + + + align:start position:0% +understanding a little bit the +relationship between these two ways of + + align:start position:0% +relationship between these two ways of + + + align:start position:0% +relationship between these two ways of +looking at the problem if I were to just + + align:start position:0% +looking at the problem if I were to just + + + align:start position:0% +looking at the problem if I were to just +look at this data and look at the effect + + align:start position:0% +look at this data and look at the effect + + + align:start position:0% +look at this data and look at the effect +of depth only on the aluminum so I'm + + align:start position:0% +of depth only on the aluminum so I'm + + + align:start position:0% +of depth only on the aluminum so I'm +just holding just looking at the + + align:start position:0% +just holding just looking at the + + + align:start position:0% +just holding just looking at the +aluminum parts for the depth of 0.6 and + + align:start position:0% +aluminum parts for the depth of 0.6 and + + + align:start position:0% +aluminum parts for the depth of 0.6 and +the depth of 0.3 there's the spread in + + align:start position:0% +the depth of 0.3 there's the spread in + + + align:start position:0% +the depth of 0.3 there's the spread in +my data I can look and say what's the + + align:start position:0% +my data I can look and say what's the + + + align:start position:0% +my data I can look and say what's the +variation within the test compared to + + align:start position:0% +variation within the test compared to + + + align:start position:0% +variation within the test compared to +the variation between tests I could then + + align:start position:0% +the variation between tests I could then + + + align:start position:0% +the variation between tests I could then +think of that as my F test or I could do + + align:start position:0% +think of that as my F test or I could do + + + align:start position:0% +think of that as my F test or I could do +a pairwise t-test or do a t-test looking + + align:start position:0% +a pairwise t-test or do a t-test looking + + + align:start position:0% +a pairwise t-test or do a t-test looking +at at the difference in the means given + + align:start position:0% +at at the difference in the means given + + + align:start position:0% +at at the difference in the means given +the spread between the two turns out to + + align:start position:0% +the spread between the two turns out to + + + align:start position:0% +the spread between the two turns out to +be the same test gives the same + + align:start position:0% +be the same test gives the same + + + align:start position:0% +be the same test gives the same +significance level whether you do it + + align:start position:0% +significance level whether you do it + + + align:start position:0% +significance level whether you do it +with an F or a T but essentially this is + + align:start position:0% +with an F or a T but essentially this is + + + align:start position:0% +with an F or a T but essentially this is +the same question I was just describing + + align:start position:0% +the same question I was just describing + + + align:start position:0% +the same question I was just describing +qualitatively on the 3d plot looking at + + align:start position:0% +qualitatively on the 3d plot looking at + + + align:start position:0% +qualitatively on the 3d plot looking at +one factor at a time I can ask the + + align:start position:0% +one factor at a time I can ask the + + + align:start position:0% +one factor at a time I can ask the +question do I think the effective depth + + align:start position:0% +question do I think the effective depth + + + align:start position:0% +question do I think the effective depth +is significant this is looking at it + + align:start position:0% +is significant this is looking at it + + + align:start position:0% +is significant this is looking at it +qualitatively I can go and chug and do + + align:start position:0% +qualitatively I can go and chug and do + + + align:start position:0% +qualitatively I can go and chug and do +the ANOVA or the t-test machinery but it + + align:start position:0% +the ANOVA or the t-test machinery but it + + + align:start position:0% +the ANOVA or the t-test machinery but it +gives the same idea I can do the same + + align:start position:0% +gives the same idea I can do the same + + + align:start position:0% +gives the same idea I can do the same +thing for the material effect say if I + + align:start position:0% +thing for the material effect say if I + + + align:start position:0% +thing for the material effect say if I +look at aluminum versus the stainless + + align:start position:0% +look at aluminum versus the stainless + + + align:start position:0% +look at aluminum versus the stainless +steel is that effect significant by the + + align:start position:0% +steel is that effect significant by the + + + align:start position:0% +steel is that effect significant by the +way you can go and chug through and do + + align:start position:0% +way you can go and chug through and do + + + align:start position:0% +way you can go and chug through and do +all of that what do you think are these + + align:start position:0% +all of that what do you think are these + + + align:start position:0% +all of that what do you think are these +factors significant I have high + + align:start position:0% +factors significant I have high + + + align:start position:0% +factors significant I have high +confidence I'm pretty confident that + + align:start position:0% +confidence I'm pretty confident that + + + align:start position:0% +confidence I'm pretty confident that +those are real effects there's a huge + + align:start position:0% +those are real effects there's a huge + + + align:start position:0% +those are real effects there's a huge +spread between these so you know the + + align:start position:0% +spread between these so you know the + + + align:start position:0% +spread between these so you know the +intuition is very clear the interaction + + align:start position:0% +intuition is very clear the interaction + + + align:start position:0% +intuition is very clear the interaction +effect that's a little tricky so we can + + align:start position:0% +effect that's a little tricky so we can + + + align:start position:0% +effect that's a little tricky so we can +go in I would actually want to run the + + align:start position:0% +go in I would actually want to run the + + + align:start position:0% +go in I would actually want to run the +ANOVA test in that case here's my raw + + align:start position:0% +ANOVA test in that case here's my raw + + + align:start position:0% +ANOVA test in that case here's my raw +data there's the model I fit again using + + align:start position:0% +data there's the model I fit again using + + + align:start position:0% +data there's the model I fit again using +the ANOVA table that we saw a minute ago + + align:start position:0% +the ANOVA table that we saw a minute ago + + + align:start position:0% +the ANOVA table that we saw a minute ago +I could by hand form that or I could put + + align:start position:0% +I could by hand form that or I could put + + + align:start position:0% +I could by hand form that or I could put +it in jump and come out with that with + + align:start position:0% +it in jump and come out with that with + + + align:start position:0% +it in jump and come out with that with +the output but now here this is very + + align:start position:0% +the output but now here this is very + + + align:start position:0% +the output but now here this is very +nice because I + + align:start position:0% +nice because I + + + align:start position:0% +nice because I +look and say okay associated with the + + align:start position:0% +look and say okay associated with the + + + align:start position:0% +look and say okay associated with the +mean x1 x2 and the interaction x1 x2 + + align:start position:0% +mean x1 x2 and the interaction x1 x2 + + + align:start position:0% +mean x1 x2 and the interaction x1 x2 +what are the mean squares and the F + + align:start position:0% +what are the mean squares and the F + + + align:start position:0% +what are the mean squares and the F +compared to our estimate of the noise + + align:start position:0% +compared to our estimate of the noise + + + align:start position:0% +compared to our estimate of the noise +remember we had 40 data points I'm + + align:start position:0% +remember we had 40 data points I'm + + + align:start position:0% +remember we had 40 data points I'm +estimating four model coefficients + + align:start position:0% +estimating four model coefficients + + + align:start position:0% +estimating four model coefficients +that's leaving 36 replicate degrees of + + align:start position:0% +that's leaving 36 replicate degrees of + + + align:start position:0% +that's leaving 36 replicate degrees of +freedom so I have a very good estimate + + align:start position:0% +freedom so I have a very good estimate + + + align:start position:0% +freedom so I have a very good estimate +of noise in the system that's the + + align:start position:0% +of noise in the system that's the + + + align:start position:0% +of noise in the system that's the +denominator in all of my F ratios and + + align:start position:0% +denominator in all of my F ratios and + + + align:start position:0% +denominator in all of my F ratios and +I'm seeing apps from 10,000 down to 77 + + align:start position:0% +I'm seeing apps from 10,000 down to 77 + + + align:start position:0% +I'm seeing apps from 10,000 down to 77 +in my F critical for 95 percent + + align:start position:0% +in my F critical for 95 percent + + + align:start position:0% +in my F critical for 95 percent +confidence is 4.1 so it looks like all + + align:start position:0% +confidence is 4.1 so it looks like all + + + align:start position:0% +confidence is 4.1 so it looks like all +of my apps are much bigger than that I + + align:start position:0% +of my apps are much bigger than that I + + + align:start position:0% +of my apps are much bigger than that I +have high confidence that the mean is + + align:start position:0% +have high confidence that the mean is + + + align:start position:0% +have high confidence that the mean is +significant these main effects are + + align:start position:0% +significant these main effects are + + + align:start position:0% +significant these main effects are +significant and the interaction is real + + align:start position:0% +significant and the interaction is real + + + align:start position:0% +significant and the interaction is real +it is bigger than I would expect given + + align:start position:0% +it is bigger than I would expect given + + + align:start position:0% +it is bigger than I would expect given +the noise in the process so I would + + align:start position:0% +the noise in the process so I would + + + align:start position:0% +the noise in the process so I would +accept all of those model terms so so + + align:start position:0% +accept all of those model terms so so + + + align:start position:0% +accept all of those model terms so so +far we use the idea of replicates to ask + + align:start position:0% +far we use the idea of replicates to ask + + + align:start position:0% +far we use the idea of replicates to ask +the significance question we said our + + align:start position:0% +the significance question we said our + + + align:start position:0% +the significance question we said our +residual could have two sources of error + + align:start position:0% +residual could have two sources of error + + + align:start position:0% +residual could have two sources of error +in it one is pure replication noise but + + align:start position:0% +in it one is pure replication noise but + + + align:start position:0% +in it one is pure replication noise but +the other thing that we haven't really + + align:start position:0% +the other thing that we haven't really + + + align:start position:0% +the other thing that we haven't really +is assessed yet is is the model form + + align:start position:0% +is assessed yet is is the model form + + + align:start position:0% +is assessed yet is is the model form +adequate you might still be nervous that + + align:start position:0% +adequate you might still be nervous that + + + align:start position:0% +adequate you might still be nervous that +maybe there's a quadratic relationship + + align:start position:0% +maybe there's a quadratic relationship + + + align:start position:0% +maybe there's a quadratic relationship +between output and the punched out with + + align:start position:0% +between output and the punched out with + + + align:start position:0% +between output and the punched out with +those two data points the best I could + + align:start position:0% +those two data points the best I could + + + align:start position:0% +those two data points the best I could +do is fit a linear model how would you + + align:start position:0% +do is fit a linear model how would you + + + align:start position:0% +do is fit a linear model how would you +possibly check to see if there might be + + align:start position:0% +possibly check to see if there might be + + + align:start position:0% +possibly check to see if there might be +curvature in the model or a quadratic + + align:start position:0% +curvature in the model or a quadratic + + + align:start position:0% +curvature in the model or a quadratic +effect do you have enough data to do + + align:start position:0% +effect do you have enough data to do + + + align:start position:0% +effect do you have enough data to do +that + + align:start position:0% + + + + align:start position:0% + +what there could be a Centrepointe + + align:start position:0% +what there could be a Centrepointe + + + align:start position:0% +what there could be a Centrepointe +let's add a center point let's consider + + align:start position:0% +let's add a center point let's consider + + + align:start position:0% +let's add a center point let's consider +additional experimental center points + + align:start position:0% +additional experimental center points + + + align:start position:0% +additional experimental center points +okay so what you would do then is is run + + align:start position:0% +okay so what you would do then is is run + + + align:start position:0% +okay so what you would do then is is run +some additional things at the center + + align:start position:0% +some additional things at the center + + + align:start position:0% +some additional things at the center +level the zero setting of those two data + + align:start position:0% +level the zero setting of those two data + + + align:start position:0% +level the zero setting of those two data +points and then look at the deviation + + align:start position:0% +points and then look at the deviation + + + align:start position:0% +points and then look at the deviation +between what the linear model suggests + + align:start position:0% +between what the linear model suggests + + + align:start position:0% +between what the linear model suggests +and what the actual data comes up with + + align:start position:0% +and what the actual data comes up with + + + align:start position:0% +and what the actual data comes up with +now you've got to ask significance of + + align:start position:0% +now you've got to ask significance of + + + align:start position:0% +now you've got to ask significance of +the Delta again your model may not be + + align:start position:0% +the Delta again your model may not be + + + align:start position:0% +the Delta again your model may not be +perfect in predicting what that center + + align:start position:0% +perfect in predicting what that center + + + align:start position:0% +perfect in predicting what that center +point is even if there is no curvature + + align:start position:0% +point is even if there is no curvature + + + align:start position:0% +point is even if there is no curvature +in the model because there's noise also + + align:start position:0% +in the model because there's noise also + + + align:start position:0% +in the model because there's noise also +in the model so we have to do two things + + align:start position:0% +in the model so we have to do two things + + + align:start position:0% +in the model so we have to do two things +one is we have to estimate the deviation + + align:start position:0% +one is we have to estimate the deviation + + + align:start position:0% +one is we have to estimate the deviation +from our simpler model the linear model + + align:start position:0% +from our simpler model the linear model + + + align:start position:0% +from our simpler model the linear model +versus the estimation with the quadratic + + align:start position:0% +versus the estimation with the quadratic + + + align:start position:0% +versus the estimation with the quadratic +term that would go through say the + + align:start position:0% +term that would go through say the + + + align:start position:0% +term that would go through say the +center point go through that additional + + align:start position:0% +center point go through that additional + + + align:start position:0% +center point go through that additional +center point and then compare the size + + align:start position:0% +center point and then compare the size + + + align:start position:0% +center point and then compare the size +of that to the natural spread in our + + align:start position:0% +of that to the natural spread in our + + + align:start position:0% +of that to the natural spread in our +data and do essentially an F test or an + + align:start position:0% +data and do essentially an F test or an + + + align:start position:0% +data and do essentially an F test or an +ANOVA test on that quadratic model term + + align:start position:0% +ANOVA test on that quadratic model term + + + align:start position:0% +ANOVA test on that quadratic model term +the same thing bother you about this + + align:start position:0% +the same thing bother you about this + + + align:start position:0% +the same thing bother you about this +picture we can set up and do this center + + align:start position:0% +picture we can set up and do this center + + + align:start position:0% +picture we can set up and do this center +point and run it right so so I'm there + + align:start position:0% +point and run it right so so I'm there + + + align:start position:0% +point and run it right so so I'm there +on the tool I'm setting the depth factor + + align:start position:0% +on the tool I'm setting the depth factor + + + align:start position:0% +on the tool I'm setting the depth factor +that's my x2 factor I guess and I've put + + align:start position:0% +that's my x2 factor I guess and I've put + + + align:start position:0% +that's my x2 factor I guess and I've put +it at zero point four or five inches I + + align:start position:0% +it at zero point four or five inches I + + + align:start position:0% +it at zero point four or five inches I +picked my part I got my aluminum I've + + align:start position:0% +picked my part I got my aluminum I've + + + align:start position:0% +picked my part I got my aluminum I've +got my stainless steel I need my zero + + align:start position:0% +got my stainless steel I need my zero + + + align:start position:0% +got my stainless steel I need my zero +level there is no center point on that + + align:start position:0% +level there is no center point on that + + + align:start position:0% +level there is no center point on that +right so you'd have to actually be very + + align:start position:0% +right so you'd have to actually be very + + + align:start position:0% +right so you'd have to actually be very +careful if you've got only discrete + + align:start position:0% +careful if you've got only discrete + + + align:start position:0% +careful if you've got only discrete +values that don't have some ordering or + + align:start position:0% +values that don't have some ordering or + + + align:start position:0% +values that don't have some ordering or +some continuous degree to them you can't + + align:start position:0% +some continuous degree to them you can't + + + align:start position:0% +some continuous degree to them you can't +do a center point right so what would + + align:start position:0% +do a center point right so what would + + + align:start position:0% +do a center point right so what would +you do in this case + + align:start position:0% +you do in this case + + + align:start position:0% +you do in this case +a physical model it's so complicated + + align:start position:0% +a physical model it's so complicated + + + align:start position:0% +a physical model it's so complicated +that's hopeless we don't have a physical + + align:start position:0% +that's hopeless we don't have a physical + + + align:start position:0% +that's hopeless we don't have a physical +model you might try a physical model + + align:start position:0% +model you might try a physical model + + + align:start position:0% +model you might try a physical model +there's something simpler you could do + + align:start position:0% +there's something simpler you could do + + + align:start position:0% +there's something simpler you could do +still using design of experiments yeah + + align:start position:0% + + + + align:start position:0% + +just use the simplest point maybe I'm + + align:start position:0% +just use the simplest point maybe I'm + + + align:start position:0% +just use the simplest point maybe I'm +thinking what additional experimental + + align:start position:0% +thinking what additional experimental + + + align:start position:0% +thinking what additional experimental +point should I run to be able to decide + + align:start position:0% +point should I run to be able to decide + + + align:start position:0% +point should I run to be able to decide +if there is an additional curvature + + align:start position:0% +if there is an additional curvature + + + align:start position:0% +if there is an additional curvature +remember we were asking the question is + + align:start position:0% +remember we were asking the question is + + + align:start position:0% +remember we were asking the question is +there curvature or a higher order term + + align:start position:0% +there curvature or a higher order term + + + align:start position:0% +there curvature or a higher order term +associated with what variable just punch + + align:start position:0% +associated with what variable just punch + + + align:start position:0% +associated with what variable just punch +them right so why don't I still pick + + align:start position:0% +them right so why don't I still pick + + + align:start position:0% +them right so why don't I still pick +this but now I can pick data points + + align:start position:0% +this but now I can pick data points + + + align:start position:0% +this but now I can pick data points +right here and I might also pick data + + align:start position:0% +right here and I might also pick data + + + align:start position:0% +right here and I might also pick data +points right here I don't have to pick + + align:start position:0% +points right here I don't have to pick + + + align:start position:0% +points right here I don't have to pick +one center point I could actually pick a + + align:start position:0% +one center point I could actually pick a + + + align:start position:0% +one center point I could actually pick a +couple in fact I could even just do the + + align:start position:0% +couple in fact I could even just do the + + + align:start position:0% +couple in fact I could even just do the +runs right here and say this is what the + + align:start position:0% +runs right here and say this is what the + + + align:start position:0% +runs right here and say this is what the +linear model would predict but if + + align:start position:0% +linear model would predict but if + + + align:start position:0% +linear model would predict but if +there's curvature in my surface then I'm + + align:start position:0% +there's curvature in my surface then I'm + + + align:start position:0% +there's curvature in my surface then I'm +gonna get a deviation just at the + + align:start position:0% +gonna get a deviation just at the + + + align:start position:0% +gonna get a deviation just at the +stainless-steel setting now if I were + + align:start position:0% +stainless-steel setting now if I were + + + align:start position:0% +stainless-steel setting now if I were +careful in trying to keep things + + align:start position:0% +careful in trying to keep things + + + align:start position:0% +careful in trying to keep things +balanced I might do the stainless steel + + align:start position:0% +balanced I might do the stainless steel + + + align:start position:0% +balanced I might do the stainless steel +and and the aluminum and get an estimate + + align:start position:0% +and and the aluminum and get an estimate + + + align:start position:0% +and and the aluminum and get an estimate +across both of those at that deviation + + align:start position:0% +across both of those at that deviation + + + align:start position:0% +across both of those at that deviation +Falls so essentially what we're trying + + align:start position:0% +Falls so essentially what we're trying + + + align:start position:0% +Falls so essentially what we're trying +to do here is add a data point and then + + align:start position:0% +to do here is add a data point and then + + + align:start position:0% +to do here is add a data point and then +look at a lack of fit test in particular + + align:start position:0% +look at a lack of fit test in particular + + + align:start position:0% +look at a lack of fit test in particular +where I want to say is the model error + + align:start position:0% +where I want to say is the model error + + + align:start position:0% +where I want to say is the model error +the deviation because of this extra + + align:start position:0% +the deviation because of this extra + + + align:start position:0% +the deviation because of this extra +higher order term is it explainable by + + align:start position:0% +higher order term is it explainable by + + + align:start position:0% +higher order term is it explainable by +pure replicate variance or is it larger + + align:start position:0% +pure replicate variance or is it larger + + + align:start position:0% +pure replicate variance or is it larger +than that and therefore not explainable + + align:start position:0% +than that and therefore not explainable + + + align:start position:0% +than that and therefore not explainable +by my noise factor if + + align:start position:0% + + + + align:start position:0% + +if we've got more deviation because of + + align:start position:0% +if we've got more deviation because of + + + align:start position:0% +if we've got more deviation because of +the of the quadratic term say if I'm + + align:start position:0% +the of the quadratic term say if I'm + + + align:start position:0% +the of the quadratic term say if I'm +adding an x squared in this model and x2 + + align:start position:0% +adding an x squared in this model and x2 + + + align:start position:0% +adding an x squared in this model and x2 +squared term then then I have to kind of + + align:start position:0% +squared term then then I have to kind of + + + align:start position:0% +squared term then then I have to kind of +reject the null hypothesis and so as + + align:start position:0% +reject the null hypothesis and so as + + + align:start position:0% +reject the null hypothesis and so as +I've just got random variance I really + + align:start position:0% +I've just got random variance I really + + + align:start position:0% +I've just got random variance I really +need an extra model term so we can still + + align:start position:0% +need an extra model term so we can still + + + align:start position:0% +need an extra model term so we can still +use the the the basic ANOVA setup so + + align:start position:0% +use the the the basic ANOVA setup so + + + align:start position:0% +use the the the basic ANOVA setup so +this is our our model with higher-order + + align:start position:0% +this is our our model with higher-order + + + align:start position:0% +this is our our model with higher-order +terms you might think about trying to + + align:start position:0% +terms you might think about trying to + + + align:start position:0% +terms you might think about trying to +add to higher order terms I would argue + + align:start position:0% +add to higher order terms I would argue + + + align:start position:0% +add to higher order terms I would argue +if this is the material type it makes no + + align:start position:0% +if this is the material type it makes no + + + align:start position:0% +if this is the material type it makes no +sense to add that term I wouldn't do + + align:start position:0% +sense to add that term I wouldn't do + + + align:start position:0% +sense to add that term I wouldn't do +that that would be bad but if this is + + align:start position:0% +that that would be bad but if this is + + + align:start position:0% +that that would be bad but if this is +associated with the punch depth then I + + align:start position:0% +associated with the punch depth then I + + + align:start position:0% +associated with the punch depth then I +think it does make sense to add the + + align:start position:0% +think it does make sense to add the + + + align:start position:0% +think it does make sense to add the +hypothesis of that and then you check + + align:start position:0% +hypothesis of that and then you check + + + align:start position:0% +hypothesis of that and then you check +for deviation at one or more of those of + + align:start position:0% +for deviation at one or more of those of + + + align:start position:0% +for deviation at one or more of those of +those points and the basic question is + + align:start position:0% +those points and the basic question is + + + align:start position:0% +those points and the basic question is +is asking whether you know beta 2 2 is + + align:start position:0% +is asking whether you know beta 2 2 is + + + align:start position:0% +is asking whether you know beta 2 2 is +equal to 0 or not is it is the effect + + align:start position:0% +equal to 0 or not is it is the effect + + + align:start position:0% +equal to 0 or not is it is the effect +due to that aviation possibly the same + + align:start position:0% +due to that aviation possibly the same + + + align:start position:0% +due to that aviation possibly the same +as noise or not so we can go through and + + align:start position:0% +as noise or not so we can go through and + + + align:start position:0% +as noise or not so we can go through and +do that here's a simple a simple test + + align:start position:0% +do that here's a simple a simple test + + + align:start position:0% +do that here's a simple a simple test +simple example and this is kind of + + align:start position:0% +simple example and this is kind of + + + align:start position:0% +simple example and this is kind of +aggregating what we saw going back and + + align:start position:0% +aggregating what we saw going back and + + + align:start position:0% +aggregating what we saw going back and +in fact some of the earlier can things + + align:start position:0% +in fact some of the earlier can things + + + align:start position:0% +in fact some of the earlier can things +we talked about if I don't have + + align:start position:0% +we talked about if I don't have + + + align:start position:0% +we talked about if I don't have +replicate data what can I do if I just + + align:start position:0% +replicate data what can I do if I just + + + align:start position:0% +replicate data what can I do if I just +do my full factorial for corner point + + align:start position:0% +do my full factorial for corner point + + + align:start position:0% +do my full factorial for corner point +test no replicates and I used the full + + align:start position:0% +test no replicates and I used the full + + + align:start position:0% +test no replicates and I used the full +linear model with interactions + + align:start position:0% +linear model with interactions + + + align:start position:0% +linear model with interactions +I cannot test for significance and I + + align:start position:0% +I cannot test for significance and I + + + align:start position:0% +I cannot test for significance and I +cannot test for lack of fit that's the + + align:start position:0% +cannot test for lack of fit that's the + + + align:start position:0% +cannot test for lack of fit that's the +most bare-bones situation you've got + + align:start position:0% +most bare-bones situation you've got + + + align:start position:0% +most bare-bones situation you've got +I've got a perfect fit but you better be + + align:start position:0% +I've got a perfect fit but you better be + + + align:start position:0% +I've got a perfect fit but you better be +awfully sure that there's not noise + + align:start position:0% +awfully sure that there's not noise + + + align:start position:0% +awfully sure that there's not noise +going on in your model or in your system + + align:start position:0% +going on in your model or in your system + + + align:start position:0% +going on in your model or in your system +so I can even without replicating my + + align:start position:0% +so I can even without replicating my + + + align:start position:0% +so I can even without replicating my +corner points I can still step back and + + align:start position:0% +corner points I can still step back and + + + align:start position:0% +corner points I can still step back and +ask the question about lack of fit by + + align:start position:0% +ask the question about lack of fit by + + + align:start position:0% +ask the question about lack of fit by +adding center points + + align:start position:0% +adding center points + + + align:start position:0% +adding center points +but if I just add one center point one + + align:start position:0% +but if I just add one center point one + + + align:start position:0% +but if I just add one center point one +replicate at the center point + + align:start position:0% +replicate at the center point + + + align:start position:0% +replicate at the center point +can I really ask the question about + + align:start position:0% +can I really ask the question about + + + align:start position:0% +can I really ask the question about +significance of the quadratic term no I + + align:start position:0% +significance of the quadratic term no I + + + align:start position:0% +significance of the quadratic term no I +would be able to perfectly fit the + + align:start position:0% +would be able to perfectly fit the + + + align:start position:0% +would be able to perfectly fit the +quadratic term with that one extra data + + align:start position:0% +quadratic term with that one extra data + + + align:start position:0% +quadratic term with that one extra data +point one extra model coefficient so you + + align:start position:0% +point one extra model coefficient so you + + + align:start position:0% +point one extra model coefficient so you +have to have replicates somewhere in the + + align:start position:0% +have to have replicates somewhere in the + + + align:start position:0% +have to have replicates somewhere in the +system and one typical approach is maybe + + align:start position:0% +system and one typical approach is maybe + + + align:start position:0% +system and one typical approach is maybe +I don't want to have ten replicates at + + align:start position:0% +I don't want to have ten replicates at + + + align:start position:0% +I don't want to have ten replicates at +each of my you know corner points I'm + + align:start position:0% +each of my you know corner points I'm + + + align:start position:0% +each of my you know corner points I'm +just gonna add replicates at my center + + align:start position:0% +just gonna add replicates at my center + + + align:start position:0% +just gonna add replicates at my center +point so now with the addition of center + + align:start position:0% +point so now with the addition of center + + + align:start position:0% +point so now with the addition of center +points to potentially check for + + align:start position:0% +points to potentially check for + + + align:start position:0% +points to potentially check for +curvature and replicates I've got an + + align:start position:0% +curvature and replicates I've got an + + + align:start position:0% +curvature and replicates I've got an +estimate of random or a replica noise + + align:start position:0% +estimate of random or a replica noise + + + align:start position:0% +estimate of random or a replica noise +and deviation from the linear so + + align:start position:0% +and deviation from the linear so + + + align:start position:0% +and deviation from the linear so +together by adding replicates at the + + align:start position:0% +together by adding replicates at the + + + align:start position:0% +together by adding replicates at the +center point you get a lot of power so + + align:start position:0% +center point you get a lot of power so + + + align:start position:0% +center point you get a lot of power so +then you can use the ANOVA approach and + + align:start position:0% +then you can use the ANOVA approach and + + + align:start position:0% +then you can use the ANOVA approach and +this is just working through and saying + + align:start position:0% +this is just working through and saying + + + align:start position:0% +this is just working through and saying +you know I estimate the quadratic term + + align:start position:0% +you know I estimate the quadratic term + + + align:start position:0% +you know I estimate the quadratic term +or the deviation and sum of squared + + align:start position:0% +or the deviation and sum of squared + + + align:start position:0% +or the deviation and sum of squared +deviations from that form an estimate of + + align:start position:0% +deviations from that form an estimate of + + + align:start position:0% +deviations from that form an estimate of +the variance because of that and compare + + align:start position:0% +the variance because of that and compare + + + align:start position:0% +the variance because of that and compare +that to the replication error so I can + + align:start position:0% +that to the replication error so I can + + + align:start position:0% +that to the replication error so I can +say here's just kind of working that out + + align:start position:0% +say here's just kind of working that out + + + align:start position:0% +say here's just kind of working that out +for our example where I've got the + + align:start position:0% +for our example where I've got the + + + align:start position:0% +for our example where I've got the +average of my outputs from the linear + + align:start position:0% +average of my outputs from the linear + + + align:start position:0% +average of my outputs from the linear +model the average at my replicate if my + + align:start position:0% +model the average at my replicate if my + + + align:start position:0% +model the average at my replicate if my +overall grand average is a little + + align:start position:0% +overall grand average is a little + + + align:start position:0% +overall grand average is a little +different than the average coming from + + align:start position:0% +different than the average coming from + + + align:start position:0% +different than the average coming from +my center point replicates that's the + + align:start position:0% +my center point replicates that's the + + + align:start position:0% +my center point replicates that's the +deviation due to the hypothesized + + align:start position:0% +deviation due to the hypothesized + + + align:start position:0% +deviation due to the hypothesized +quadratic term I can form the variance + + align:start position:0% +quadratic term I can form the variance + + + align:start position:0% +quadratic term I can form the variance +of that and then compare that to my + + align:start position:0% +of that and then compare that to my + + + align:start position:0% +of that and then compare that to my +underlying estimate okay and then this + + align:start position:0% +underlying estimate okay and then this + + + align:start position:0% +underlying estimate okay and then this +example I'll let you work through this + + align:start position:0% +example I'll let you work through this + + + align:start position:0% +example I'll let you work through this +is just doing that for a simple run + + align:start position:0% +is just doing that for a simple run + + + align:start position:0% +is just doing that for a simple run +where again I have just one run at each + + align:start position:0% +where again I have just one run at each + + + align:start position:0% +where again I have just one run at each +of the four corner points this is a + + align:start position:0% +of the four corner points this is a + + + align:start position:0% +of the four corner points this is a +different data set by the way this is + + align:start position:0% +different data set by the way this is + + + align:start position:0% +different data set by the way this is +not the break forming anymore and then + + align:start position:0% +not the break forming anymore and then + + + align:start position:0% +not the break forming anymore and then +I've got five replicates here at the + + align:start position:0% +I've got five replicates here at the + + + align:start position:0% +I've got five replicates here at the +center point question + + align:start position:0% + + + + align:start position:0% + +yes so we are making the assumption here + + align:start position:0% +yes so we are making the assumption here + + + align:start position:0% +yes so we are making the assumption here +and it's the same one we've made pretty + + align:start position:0% +and it's the same one we've made pretty + + + align:start position:0% +and it's the same one we've made pretty +much in most ANOVA analyses that the + + align:start position:0% +much in most ANOVA analyses that the + + + align:start position:0% +much in most ANOVA analyses that the +variance is the same at all + + align:start position:0% +variance is the same at all + + + align:start position:0% +variance is the same at all +run points in other words we have the N + + align:start position:0% +run points in other words we have the N + + + align:start position:0% +run points in other words we have the N +0 Sigma squared assumption where Sigma + + align:start position:0% +0 Sigma squared assumption where Sigma + + + align:start position:0% +0 Sigma squared assumption where Sigma +squared is operative at the center point + + align:start position:0% +squared is operative at the center point + + + align:start position:0% +squared is operative at the center point +as well as all the corner points so this + + align:start position:0% +as well as all the corner points so this + + + align:start position:0% +as well as all the corner points so this +is a neat example where again we're + + align:start position:0% +is a neat example where again we're + + + align:start position:0% +is a neat example where again we're +trying to estimate main effects perhaps + + align:start position:0% +trying to estimate main effects perhaps + + + align:start position:0% +trying to estimate main effects perhaps +interaction effects we've got an a/b + + align:start position:0% +interaction effects we've got an a/b + + + align:start position:0% +interaction effects we've got an a/b +interaction column here now I've also + + align:start position:0% +interaction column here now I've also + + + align:start position:0% +interaction column here now I've also +got it so just using the corner points + + align:start position:0% +got it so just using the corner points + + + align:start position:0% +got it so just using the corner points +we can fit fit a model we can ask the + + align:start position:0% +we can fit fit a model we can ask the + + + align:start position:0% +we can fit fit a model we can ask the +ANOVA question on significance of that + + align:start position:0% +ANOVA question on significance of that + + + align:start position:0% +ANOVA question on significance of that +but I can also form the sum of squares + + align:start position:0% +but I can also form the sum of squares + + + align:start position:0% +but I can also form the sum of squares +due to this quadratic term and use the + + align:start position:0% +due to this quadratic term and use the + + + align:start position:0% +due to this quadratic term and use the +replicate information there to be able + + align:start position:0% +replicate information there to be able + + + align:start position:0% +replicate information there to be able +to form an estimate of the overall + + align:start position:0% +to form an estimate of the overall + + + align:start position:0% +to form an estimate of the overall +process variance and what that lets me + + align:start position:0% +process variance and what that lets me + + + align:start position:0% +process variance and what that lets me +do is form the F test line in here for + + align:start position:0% +do is form the F test line in here for + + + align:start position:0% +do is form the F test line in here for +the quadratic term in addition to the + + align:start position:0% +the quadratic term in addition to the + + + align:start position:0% +the quadratic term in addition to the +a/b and the interaction term and in this + + align:start position:0% +a/b and the interaction term and in this + + + align:start position:0% +a/b and the interaction term and in this +case when I look at that F ratio the sum + + align:start position:0% +case when I look at that F ratio the sum + + + align:start position:0% +case when I look at that F ratio the sum +of squared deviations from the quadratic + + align:start position:0% +of squared deviations from the quadratic + + + align:start position:0% +of squared deviations from the quadratic +estimate versus the linear estimate + + align:start position:0% +estimate versus the linear estimate + + + align:start position:0% +estimate versus the linear estimate +compared to my estimate of noise in the + + align:start position:0% +compared to my estimate of noise in the + + + align:start position:0% +compared to my estimate of noise in the +system I get a very small F well below + + align:start position:0% +system I get a very small F well below + + + align:start position:0% +system I get a very small F well below +the critical and therefore I conclude + + align:start position:0% +the critical and therefore I conclude + + + align:start position:0% +the critical and therefore I conclude +there is no evidence of lack of fit I do + + align:start position:0% +there is no evidence of lack of fit I do + + + align:start position:0% +there is no evidence of lack of fit I do +not include the quadratic term and I + + align:start position:0% +not include the quadratic term and I + + + align:start position:0% +not include the quadratic term and I +stick with the linear model now would + + align:start position:0% +stick with the linear model now would + + + align:start position:0% +stick with the linear model now would +you keep the interaction term same thing + + align:start position:0% +you keep the interaction term same thing + + + align:start position:0% +you keep the interaction term same thing +it's also not significant would you keep + + align:start position:0% +it's also not significant would you keep + + + align:start position:0% +it's also not significant would you keep +the to main effect terms + + align:start position:0% +the to main effect terms + + + align:start position:0% +the to main effect terms +yeah sure those are above the above the + + align:start position:0% +yeah sure those are above the above the + + + align:start position:0% +yeah sure those are above the above the +F naught so I'm happy with those so this + + align:start position:0% +F naught so I'm happy with those so this + + + align:start position:0% +F naught so I'm happy with those so this +is a nice simple data set additive + + align:start position:0% +is a nice simple data set additive + + + align:start position:0% +is a nice simple data set additive +effects no interaction it's kind of the + + align:start position:0% +effects no interaction it's kind of the + + + align:start position:0% +effects no interaction it's kind of the +best for ultimately using the model in a + + align:start position:0% +best for ultimately using the model in a + + + align:start position:0% +best for ultimately using the model in a +in a control kind of setting because I + + align:start position:0% +in a control kind of setting because I + + + align:start position:0% +in a control kind of setting because I +can presumably change and + + align:start position:0% +can presumably change and + + + align:start position:0% +can presumably change and +independently and try to get the output + + align:start position:0% +independently and try to get the output + + + align:start position:0% +independently and try to get the output +that I want I mean you're always you + + align:start position:0% +that I want I mean you're always you + + + align:start position:0% +that I want I mean you're always you +always got to be a little careful and + + align:start position:0% +always got to be a little careful and + + + align:start position:0% +always got to be a little careful and +use exactly that knowledge you know this + + align:start position:0% +use exactly that knowledge you know this + + + align:start position:0% +use exactly that knowledge you know this +was a this was a 95% confidence and if I + + align:start position:0% +was a this was a 95% confidence and if I + + + align:start position:0% +was a this was a 95% confidence and if I +was anywhere near the boundary I might + + align:start position:0% +was anywhere near the boundary I might + + + align:start position:0% +was anywhere near the boundary I might +say well might might I want to include + + align:start position:0% +say well might might I want to include + + + align:start position:0% +say well might might I want to include +that if I wanted to just be 90 percent + + align:start position:0% +that if I wanted to just be 90 percent + + + align:start position:0% +that if I wanted to just be 90 percent +confidence because that's probably + + align:start position:0% +confidence because that's probably + + + align:start position:0% +confidence because that's probably +suggesting that that model term really + + align:start position:0% +suggesting that that model term really + + + align:start position:0% +suggesting that that model term really +does have an effect in this case that + + align:start position:0% +does have an effect in this case that + + + align:start position:0% +does have an effect in this case that +cutoff you know those are very obvious + + align:start position:0% +cutoff you know those are very obvious + + + align:start position:0% +cutoff you know those are very obvious +but in other subtle cases you actually + + align:start position:0% +but in other subtle cases you actually + + + align:start position:0% +but in other subtle cases you actually +have to use some some intuition and + + align:start position:0% +have to use some some intuition and + + + align:start position:0% +have to use some some intuition and +knowledge one one one part of that does + + align:start position:0% +knowledge one one one part of that does + + + align:start position:0% +knowledge one one one part of that does +look at and maybe you're getting at this + + align:start position:0% +look at and maybe you're getting at this + + + align:start position:0% +look at and maybe you're getting at this +a little bit with sensitivity there's + + align:start position:0% +a little bit with sensitivity there's + + + align:start position:0% +a little bit with sensitivity there's +another sensitivity analysis you can do + + align:start position:0% +another sensitivity analysis you can do + + + align:start position:0% +another sensitivity analysis you can do +which which has to do with not the not + + align:start position:0% +which which has to do with not the not + + + align:start position:0% +which which has to do with not the not +tweaking the alpha level the + + align:start position:0% +tweaking the alpha level the + + + align:start position:0% +tweaking the alpha level the +significance level you can tweak that a + + align:start position:0% +significance level you can tweak that a + + + align:start position:0% +significance level you can tweak that a +little bit but you also might ask the + + align:start position:0% +little bit but you also might ask the + + + align:start position:0% +little bit but you also might ask the +question slightly differently about + + align:start position:0% +question slightly differently about + + + align:start position:0% +question slightly differently about +whether the model coefficient is real or + + align:start position:0% +whether the model coefficient is real or + + + align:start position:0% +whether the model coefficient is real or +not + + align:start position:0% +not + + + align:start position:0% +not +that's a significance question you can + + align:start position:0% +that's a significance question you can + + + align:start position:0% +that's a significance question you can +also ask the question how big is the + + align:start position:0% +also ask the question how big is the + + + align:start position:0% +also ask the question how big is the +effect is it so big that I would want to + + align:start position:0% +effect is it so big that I would want to + + + align:start position:0% +effect is it so big that I would want to +include it in the model or it's real but + + align:start position:0% +include it in the model or it's real but + + + align:start position:0% +include it in the model or it's real but +it's so tiny compared to my other + + align:start position:0% +it's so tiny compared to my other + + + align:start position:0% +it's so tiny compared to my other +effects that I'm going to neglect it so + + align:start position:0% +effects that I'm going to neglect it so + + + align:start position:0% +effects that I'm going to neglect it so +there is this difference between + + align:start position:0% +there is this difference between + + + align:start position:0% +there is this difference between +significant real and important or not + + align:start position:0% +significant real and important or not + + + align:start position:0% +significant real and important or not +and so that's where your knowledge of + + align:start position:0% +and so that's where your knowledge of + + + align:start position:0% +and so that's where your knowledge of +the process also comes into play and + + align:start position:0% +the process also comes into play and + + + align:start position:0% +the process also comes into play and +whether you might want to include or + + align:start position:0% +whether you might want to include or + + + align:start position:0% +whether you might want to include or +drop model terms okay I think what we'll + + align:start position:0% +drop model terms okay I think what we'll + + + align:start position:0% +drop model terms okay I think what we'll +do is although right actually only go + + align:start position:0% +do is although right actually only go + + + align:start position:0% +do is although right actually only go +for about five more minutes and give you + + align:start position:0% +for about five more minutes and give you + + + align:start position:0% +for about five more minutes and give you +a little bit of a glimpse of blocks and + + align:start position:0% +a little bit of a glimpse of blocks and + + + align:start position:0% +a little bit of a glimpse of blocks and +co-found confounding talk about these + + align:start position:0% +co-found confounding talk about these + + + align:start position:0% +co-found confounding talk about these +nuisance factors a little bit and then + + align:start position:0% +nuisance factors a little bit and then + + + align:start position:0% +nuisance factors a little bit and then +next time we'll come back and dive in + + align:start position:0% +next time we'll come back and dive in + + + align:start position:0% +next time we'll come back and dive in +more on + + align:start position:0% +more on + + + align:start position:0% +more on +fractional factorial designs because + + align:start position:0% +fractional factorial designs because + + + align:start position:0% +fractional factorial designs because +there are some additional design issues + + align:start position:0% +there are some additional design issues + + + align:start position:0% +there are some additional design issues +I've only alluded to in experimental + + align:start position:0% +I've only alluded to in experimental + + + align:start position:0% +I've only alluded to in experimental +design + + align:start position:0% +design + + + align:start position:0% +design +so far we've really just done full + + align:start position:0% +so far we've really just done full + + + align:start position:0% +so far we've really just done full +factorial these corner points and then + + align:start position:0% +factorial these corner points and then + + + align:start position:0% +factorial these corner points and then +also the idea of Centrepointe stacked + + align:start position:0% +also the idea of Centrepointe stacked + + + align:start position:0% +also the idea of Centrepointe stacked +asked the question about curvature but + + align:start position:0% +asked the question about curvature but + + + align:start position:0% +asked the question about curvature but +there may be other factors you know + + align:start position:0% +there may be other factors you know + + + align:start position:0% +there may be other factors you know +maybe there was the temperature in our + + align:start position:0% +maybe there was the temperature in our + + + align:start position:0% +maybe there was the temperature in our +break forming tool that we didn't really + + align:start position:0% +break forming tool that we didn't really + + + align:start position:0% +break forming tool that we didn't really +want to do a design experiment on we're + + align:start position:0% +want to do a design experiment on we're + + + align:start position:0% +want to do a design experiment on we're +not really sure it's important or not + + align:start position:0% +not really sure it's important or not + + + align:start position:0% +not really sure it's important or not +but maybe it's out there there may be + + align:start position:0% +but maybe it's out there there may be + + + align:start position:0% +but maybe it's out there there may be +all these other new synthetic nuisance + + align:start position:0% +all these other new synthetic nuisance + + + align:start position:0% +all these other new synthetic nuisance +factors or nuisance effects they may + + align:start position:0% +factors or nuisance effects they may + + + align:start position:0% +factors or nuisance effects they may +affect the output but I didn't really + + align:start position:0% +affect the output but I didn't really + + + align:start position:0% +affect the output but I didn't really +want to include the effect in the model + + align:start position:0% +want to include the effect in the model + + + align:start position:0% +want to include the effect in the model +and I rather suppress them and for sure + + align:start position:0% +and I rather suppress them and for sure + + + align:start position:0% +and I rather suppress them and for sure +suppress them from making from me making + + align:start position:0% +suppress them from making from me making + + + align:start position:0% +suppress them from making from me making +a mistake and and confusing the effect + + align:start position:0% +a mistake and and confusing the effect + + + align:start position:0% +a mistake and and confusing the effect +of temperature with say the effect of + + align:start position:0% +of temperature with say the effect of + + + align:start position:0% +of temperature with say the effect of +which metal I use so what are the + + align:start position:0% +which metal I use so what are the + + + align:start position:0% +which metal I use so what are the +approaches you can do well in many cases + + align:start position:0% +approaches you can do well in many cases + + + align:start position:0% +approaches you can do well in many cases +I may not be able to run the whole + + align:start position:0% +I may not be able to run the whole + + + align:start position:0% +I may not be able to run the whole +experiment holding that factor constant + + align:start position:0% +experiment holding that factor constant + + + align:start position:0% +experiment holding that factor constant +in general you would really want to make + + align:start position:0% +in general you would really want to make + + + align:start position:0% +in general you would really want to make +sure + + align:start position:0% +sure + + + align:start position:0% +sure +well if temperature affects things I + + align:start position:0% +well if temperature affects things I + + + align:start position:0% +well if temperature affects things I +want to hold the temperature of the tool + + align:start position:0% +want to hold the temperature of the tool + + + align:start position:0% +want to hold the temperature of the tool +as constant as I can try to keep + + align:start position:0% +as constant as I can try to keep + + + align:start position:0% +as constant as I can try to keep +everything else as constant as possible + + align:start position:0% +everything else as constant as possible + + + align:start position:0% +everything else as constant as possible +time can often be an important + + align:start position:0% +time can often be an important + + + align:start position:0% +time can often be an important +substitute for nuisance effects right + + align:start position:0% +substitute for nuisance effects right + + + align:start position:0% +substitute for nuisance effects right +time is going on and other things may be + + align:start position:0% +time is going on and other things may be + + + align:start position:0% +time is going on and other things may be +changing so you can't entirely suppress + + align:start position:0% +changing so you can't entirely suppress + + + align:start position:0% +changing so you can't entirely suppress +potentially all these other nuisance + + align:start position:0% +potentially all these other nuisance + + + align:start position:0% +potentially all these other nuisance +effects but in general you want to keep + + align:start position:0% +effects but in general you want to keep + + + align:start position:0% +effects but in general you want to keep +everything else constant but some cases + + align:start position:0% +everything else constant but some cases + + + align:start position:0% +everything else constant but some cases +you may not be able to hold everything + + align:start position:0% +you may not be able to hold everything + + + align:start position:0% +you may not be able to hold everything +else constant and if you know some of + + align:start position:0% +else constant and if you know some of + + + align:start position:0% +else constant and if you know some of +these factors like temperature perhaps + + align:start position:0% +these factors like temperature perhaps + + + align:start position:0% +these factors like temperature perhaps +you know throughout the day varies in my + + align:start position:0% +you know throughout the day varies in my + + + align:start position:0% +you know throughout the day varies in my +machine shop say then it may be + + align:start position:0% +machine shop say then it may be + + + align:start position:0% +machine shop say then it may be +uncontrollable but it's a known factor + + align:start position:0% +uncontrollable but it's a known factor + + + align:start position:0% +uncontrollable but it's a known factor +in which case I might want to think + + align:start position:0% +in which case I might want to think + + + align:start position:0% +in which case I might want to think +about that and randomize the order of my + + align:start position:0% +about that and randomize the order of my + + + align:start position:0% +about that and randomize the order of my +runs against that so I equally includes + + align:start position:0% +runs against that so I equally includes + + + align:start position:0% +runs against that so I equally includes +some high levels of that nuisance factor + + align:start position:0% +some high levels of that nuisance factor + + + align:start position:0% +some high levels of that nuisance factor +and some low levels of that nuisance + + align:start position:0% +and some low levels of that nuisance + + + align:start position:0% +and some low levels of that nuisance +in each of my other settings I try as + + align:start position:0% +in each of my other settings I try as + + + align:start position:0% +in each of my other settings I try as +much as I can to randomize basically + + align:start position:0% +much as I can to randomize basically + + + align:start position:0% +much as I can to randomize basically +convert that effect from a systemic + + align:start position:0% +convert that effect from a systemic + + + align:start position:0% +convert that effect from a systemic +effect into a random noise effect okay + + align:start position:0% +effect into a random noise effect okay + + + align:start position:0% +effect into a random noise effect okay +in many cases if I can actually pick the + + align:start position:0% +in many cases if I can actually pick the + + + align:start position:0% +in many cases if I can actually pick the +level of temperature it's known and + + align:start position:0% +level of temperature it's known and + + + align:start position:0% +level of temperature it's known and +controllable you can actually design + + align:start position:0% +controllable you can actually design + + + align:start position:0% +controllable you can actually design +your experiment separate out the data + + align:start position:0% +your experiment separate out the data + + + align:start position:0% +your experiment separate out the data +into blocks where in each of the two + + align:start position:0% +into blocks where in each of the two + + + align:start position:0% +into blocks where in each of the two +blocks the nuisance factor is held + + align:start position:0% +blocks the nuisance factor is held + + + align:start position:0% +blocks the nuisance factor is held +constant and what we have the + + align:start position:0% +constant and what we have the + + + align:start position:0% +constant and what we have the +opportunity to do is transform the + + align:start position:0% +opportunity to do is transform the + + + align:start position:0% +opportunity to do is transform the +effect of that nuisance factor into what + + align:start position:0% +effect of that nuisance factor into what + + + align:start position:0% +effect of that nuisance factor into what +would only be a very higher-order + + align:start position:0% +would only be a very higher-order + + + align:start position:0% +would only be a very higher-order +interaction term in our model okay and + + align:start position:0% +interaction term in our model okay and + + + align:start position:0% +interaction term in our model okay and +that's the intuition I want to just give + + align:start position:0% +that's the intuition I want to just give + + + align:start position:0% +that's the intuition I want to just give +you a little bit of a glimpse for and + + align:start position:0% +you a little bit of a glimpse for and + + + align:start position:0% +you a little bit of a glimpse for and +then we'll talk about next time first + + align:start position:0% +then we'll talk about next time first + + + align:start position:0% +then we'll talk about next time first +off if if the thing is controllable we + + align:start position:0% +off if if the thing is controllable we + + + align:start position:0% +off if if the thing is controllable we +would just want to say replicate and + + align:start position:0% +would just want to say replicate and + + + align:start position:0% +would just want to say replicate and +randomize here's an example where we're + + align:start position:0% +randomize here's an example where we're + + + align:start position:0% +randomize here's an example where we're +looking for the hardness of four + + align:start position:0% +looking for the hardness of four + + + align:start position:0% +looking for the hardness of four +different test samples but I'm doing it + + align:start position:0% +different test samples but I'm doing it + + + align:start position:0% +different test samples but I'm doing it +with an indentation Tet test but I've + + align:start position:0% +with an indentation Tet test but I've + + + align:start position:0% +with an indentation Tet test but I've +got four different tips that I'm using + + align:start position:0% +got four different tips that I'm using + + + align:start position:0% +got four different tips that I'm using +for the indentation + + align:start position:0% +for the indentation + + + align:start position:0% +for the indentation +I don't really won't care about the tip + + align:start position:0% +I don't really won't care about the tip + + + align:start position:0% +I don't really won't care about the tip +factor but I'm worried that it might + + align:start position:0% +factor but I'm worried that it might + + + align:start position:0% +factor but I'm worried that it might +might perturb my estimate of the + + align:start position:0% +might perturb my estimate of the + + + align:start position:0% +might perturb my estimate of the +hardness so you can first off basically + + align:start position:0% +hardness so you can first off basically + + + align:start position:0% +hardness so you can first off basically +think of it as I'm just gonna run with + + align:start position:0% +think of it as I'm just gonna run with + + + align:start position:0% +think of it as I'm just gonna run with +all four tips and take the average and + + align:start position:0% +all four tips and take the average and + + + align:start position:0% +all four tips and take the average and +that's my best average of our estimate + + align:start position:0% +that's my best average of our estimate + + + align:start position:0% +that's my best average of our estimate +of the hardness in the four cases so I'm + + align:start position:0% +of the hardness in the four cases so I'm + + + align:start position:0% +of the hardness in the four cases so I'm +just replicating around that nuisance + + align:start position:0% +just replicating around that nuisance + + + align:start position:0% +just replicating around that nuisance +factor not including it in the model + + align:start position:0% +factor not including it in the model + + + align:start position:0% +factor not including it in the model +explicitly but I'm randomizing or or + + align:start position:0% +explicitly but I'm randomizing or or + + + align:start position:0% +explicitly but I'm randomizing or or +replicating around it many cases you + + align:start position:0% +replicating around it many cases you + + + align:start position:0% +replicating around it many cases you +don't have the opportunity it's too + + align:start position:0% +don't have the opportunity it's too + + + align:start position:0% +don't have the opportunity it's too +expensive to do lots of replications and + + align:start position:0% +expensive to do lots of replications and + + + align:start position:0% +expensive to do lots of replications and +what what I want to do is arrange things + + align:start position:0% +what what I want to do is arrange things + + + align:start position:0% +what what I want to do is arrange things +so that if there is a nuisance factor it + + align:start position:0% +so that if there is a nuisance factor it + + + align:start position:0% +so that if there is a nuisance factor it +will have them + + align:start position:0% +will have them + + + align:start position:0% +will have them +least damaging effect on my model so + + align:start position:0% +least damaging effect on my model so + + + align:start position:0% +least damaging effect on my model so +here's my one little Intuit intuitive + + align:start position:0% +here's my one little Intuit intuitive + + + align:start position:0% +here's my one little Intuit intuitive +example suppose we've got this + + align:start position:0% +example suppose we've got this + + + align:start position:0% +example suppose we've got this +two-by-two design so I've got two + + align:start position:0% +two-by-two design so I've got two + + + align:start position:0% +two-by-two design so I've got two +factors two levels doing four runs but + + align:start position:0% +factors two levels doing four runs but + + + align:start position:0% +factors two levels doing four runs but +let's say I have to arrange it where I + + align:start position:0% +let's say I have to arrange it where I + + + align:start position:0% +let's say I have to arrange it where I +do two runs at low temperature and two + + align:start position:0% +do two runs at low temperature and two + + + align:start position:0% +do two runs at low temperature and two +runs at high temperature that's just I'm + + align:start position:0% +runs at high temperature that's just I'm + + + align:start position:0% +runs at high temperature that's just I'm +gonna have to do two runs in the morning + + align:start position:0% +gonna have to do two runs in the morning + + + align:start position:0% +gonna have to do two runs in the morning +two in the afternoon and during the day + + align:start position:0% +two in the afternoon and during the day + + + align:start position:0% +two in the afternoon and during the day +my machine shop heats up that's just the + + align:start position:0% +my machine shop heats up that's just the + + + align:start position:0% +my machine shop heats up that's just the +way it is I gotta live with it which two + + align:start position:0% +way it is I gotta live with it which two + + + align:start position:0% +way it is I gotta live with it which two +runs should I pick to do with the high + + align:start position:0% +runs should I pick to do with the high + + + align:start position:0% +runs should I pick to do with the high +temperature in which to run should I do + + align:start position:0% +temperature in which to run should I do + + + align:start position:0% +temperature in which to run should I do +at the low temperature suppose I did it + + align:start position:0% +at the low temperature suppose I did it + + + align:start position:0% +at the low temperature suppose I did it +like this where this was my low + + align:start position:0% +like this where this was my low + + + align:start position:0% +like this where this was my low +temperature and this was my high + + align:start position:0% +temperature and this was my high + + + align:start position:0% +temperature and this was my high +temperature any problem with that + + align:start position:0% + + + + align:start position:0% + +big problem with that if x2 has an + + align:start position:0% +big problem with that if x2 has an + + + align:start position:0% +big problem with that if x2 has an +effect I can't tell whether that's a + + align:start position:0% +effect I can't tell whether that's a + + + align:start position:0% +effect I can't tell whether that's a +temperature effect or an x2 effect + + align:start position:0% +temperature effect or an x2 effect + + + align:start position:0% +temperature effect or an x2 effect +because I did both of my x2 runs at the + + align:start position:0% +because I did both of my x2 runs at the + + + align:start position:0% +because I did both of my x2 runs at the +low temperature and both of my you know + + align:start position:0% +low temperature and both of my you know + + + align:start position:0% +low temperature and both of my you know +high values of x2 but the high + + align:start position:0% +high values of x2 but the high + + + align:start position:0% +high values of x2 but the high +temperature I don't know whether it's a + + align:start position:0% +temperature I don't know whether it's a + + + align:start position:0% +temperature I don't know whether it's a +temperature effect when I form that + + align:start position:0% +temperature effect when I form that + + + align:start position:0% +temperature effect when I form that +contrast or an x2 effect is there a + + align:start position:0% +contrast or an x2 effect is there a + + + align:start position:0% +contrast or an x2 effect is there a +better way to arrange or pick which two + + align:start position:0% +better way to arrange or pick which two + + + align:start position:0% +better way to arrange or pick which two +ones I want to do so that I don't get + + align:start position:0% +ones I want to do so that I don't get + + + align:start position:0% +ones I want to do so that I don't get +confused with the main effects in the + + align:start position:0% +confused with the main effects in the + + + align:start position:0% +confused with the main effects in the +experiment and the intuition here is yes + + align:start position:0% +experiment and the intuition here is yes + + + align:start position:0% +experiment and the intuition here is yes +there is a better approach what if I + + align:start position:0% +there is a better approach what if I + + + align:start position:0% +there is a better approach what if I +pick block one to run the one and a B + + align:start position:0% +pick block one to run the one and a B + + + align:start position:0% +pick block one to run the one and a B +combinations so what if I pick block one + + align:start position:0% +combinations so what if I pick block one + + + align:start position:0% +combinations so what if I pick block one +to run what I say the one in the a b1 + + align:start position:0% +to run what I say the one in the a b1 + + + align:start position:0% +to run what I say the one in the a b1 +and a B notice what's nice about that + + align:start position:0% +and a B notice what's nice about that + + + align:start position:0% +and a B notice what's nice about that +the one in the ad so make that block one + + align:start position:0% +the one in the ad so make that block one + + + align:start position:0% +the one in the ad so make that block one +and make this block to notice that + + align:start position:0% +and make this block to notice that + + + align:start position:0% +and make this block to notice that +neither block is + + align:start position:0% + + + + align:start position:0% + +corresponding to both high settings or + + align:start position:0% +corresponding to both high settings or + + + align:start position:0% +corresponding to both high settings or +both low settings for either factor when + + align:start position:0% +both low settings for either factor when + + + align:start position:0% +both low settings for either factor when +in fact the block is is actually lining + + align:start position:0% +in fact the block is is actually lining + + + align:start position:0% +in fact the block is is actually lining +up with is the x1x2 interaction factor + + align:start position:0% +up with is the x1x2 interaction factor + + + align:start position:0% +up with is the x1x2 interaction factor +so what we've done is said I'm going to + + align:start position:0% +so what we've done is said I'm going to + + + align:start position:0% +so what we've done is said I'm going to +I don't want to get confused about + + align:start position:0% +I don't want to get confused about + + + align:start position:0% +I don't want to get confused about +whether there's a main effect or this + + align:start position:0% +whether there's a main effect or this + + + align:start position:0% +whether there's a main effect or this +that's nasty nuisance factor is having + + align:start position:0% +that's nasty nuisance factor is having + + + align:start position:0% +that's nasty nuisance factor is having +an effect what I would am willing to do + + align:start position:0% +an effect what I would am willing to do + + + align:start position:0% +an effect what I would am willing to do +is be confused or confound between my + + align:start position:0% +is be confused or confound between my + + + align:start position:0% +is be confused or confound between my +block effect and my interaction effect I + + align:start position:0% +block effect and my interaction effect I + + + align:start position:0% +block effect and my interaction effect I +won't be able to tell if the interaction + + align:start position:0% +won't be able to tell if the interaction + + + align:start position:0% +won't be able to tell if the interaction +is real or not but that's okay I believe + + align:start position:0% +is real or not but that's okay I believe + + + align:start position:0% +is real or not but that's okay I believe +it's not and I'd rather mix in my my + + align:start position:0% +it's not and I'd rather mix in my my + + + align:start position:0% +it's not and I'd rather mix in my my +block factor so this gets to this idea + + align:start position:0% +block factor so this gets to this idea + + + align:start position:0% +block factor so this gets to this idea +of forming patterns or blocking in this + + align:start position:0% +of forming patterns or blocking in this + + + align:start position:0% +of forming patterns or blocking in this +case to confound so that I can detect + + align:start position:0% +case to confound so that I can detect + + + align:start position:0% +case to confound so that I can detect +some things and not others + + align:start position:0% +some things and not others + + + align:start position:0% +some things and not others +and we'll talk more about that next time + + align:start position:0% +and we'll talk more about that next time + + + align:start position:0% +and we'll talk more about that next time +talk a little bit more generally about + + align:start position:0% +talk a little bit more generally about + + + align:start position:0% +talk a little bit more generally about +confounding and this actually leads into + + align:start position:0% +confounding and this actually leads into + + + align:start position:0% +confounding and this actually leads into +the main idea of fractional factorial + + align:start position:0% +the main idea of fractional factorial + + + align:start position:0% +the main idea of fractional factorial +design where I may not want to pick all + + align:start position:0% +design where I may not want to pick all + + + align:start position:0% +design where I may not want to pick all +of my corner points I might subset some + + align:start position:0% +of my corner points I might subset some + + + align:start position:0% +of my corner points I might subset some +of them because I'm willing to be + + align:start position:0% +of them because I'm willing to be + + + align:start position:0% +of them because I'm willing to be +confused about whether there's a fourth + + align:start position:0% +confused about whether there's a fourth + + + align:start position:0% +confused about whether there's a fourth +order factor that's also the same + + align:start position:0% +order factor that's also the same + + + align:start position:0% +order factor that's also the same +detection or same contrast with a second + + align:start position:0% +detection or same contrast with a second + + + align:start position:0% +detection or same contrast with a second +order interaction factor I don't care + + align:start position:0% +order interaction factor I don't care + + + align:start position:0% +order interaction factor I don't care +and therefore if I don't care I can + + align:start position:0% +and therefore if I don't care I can + + + align:start position:0% +and therefore if I don't care I can +actually reduce the number of + + align:start position:0% +actually reduce the number of + + + align:start position:0% +actually reduce the number of +experimental points we want to do so + + align:start position:0% +experimental points we want to do so + + + align:start position:0% +experimental points we want to do so +we'll talk about that next time \ No newline at end of file diff --git a/GP8RSRrWtMU.txt b/GP8RSRrWtMU.txt new file mode 100644 index 0000000000000000000000000000000000000000..e5e12c49dcb89ff2e430d5a4e28bc88a31da4bcb --- /dev/null +++ b/GP8RSRrWtMU.txt @@ -0,0 +1,12571 @@ +align:start position:0% + +so today we are going to be talking + + align:start position:0% +so today we are going to be talking + + + align:start position:0% +so today we are going to be talking +about proton radiography and proton + + align:start position:0% + + + + align:start position:0% + +Imaging so we're starting a series of + + align:start position:0% +Imaging so we're starting a series of + + + align:start position:0% +Imaging so we're starting a series of +three lectures in which we're looking at + + align:start position:0% +three lectures in which we're looking at + + + align:start position:0% +three lectures in which we're looking at +how to use particles as PR in the plasma + + align:start position:0% +how to use particles as PR in the plasma + + + align:start position:0% +how to use particles as PR in the plasma +previously you remember we used + + align:start position:0% +previously you remember we used + + + align:start position:0% +previously you remember we used +electromagnetic radiation and we looked + + align:start position:0% +electromagnetic radiation and we looked + + + align:start position:0% +electromagnetic radiation and we looked +at the emission from the plasma but now + + align:start position:0% +at the emission from the plasma but now + + + align:start position:0% +at the emission from the plasma but now +we're actively pushing particles through + + align:start position:0% +we're actively pushing particles through + + + align:start position:0% +we're actively pushing particles through +the plasma seeing what happens so + + align:start position:0% +the plasma seeing what happens so + + + align:start position:0% +the plasma seeing what happens so +imagine and we'll talk about exactly how + + align:start position:0% +imagine and we'll talk about exactly how + + + align:start position:0% +imagine and we'll talk about exactly how +you do this later on that you have some + + align:start position:0% +you do this later on that you have some + + + align:start position:0% +you do this later on that you have some +source of protons a beam of + + align:start position:0% +source of protons a beam of + + + align:start position:0% +source of protons a beam of +protons with some spread maybe it's + + align:start position:0% +protons with some spread maybe it's + + + align:start position:0% +protons with some spread maybe it's +emitting into four Pi ster agent maybe + + align:start position:0% +emitting into four Pi ster agent maybe + + + align:start position:0% +emitting into four Pi ster agent maybe +it's a tightly focused beam doesn't + + align:start position:0% +it's a tightly focused beam doesn't + + + align:start position:0% +it's a tightly focused beam doesn't +really matter you have plasma + + align:start position:0% +really matter you have plasma + + + align:start position:0% +really matter you have plasma +here and maybe within that plasma you + + align:start position:0% +here and maybe within that plasma you + + + align:start position:0% +here and maybe within that plasma you +have some magnetic fields so you have + + align:start position:0% +have some magnetic fields so you have + + + align:start position:0% +have some magnetic fields so you have +magnetic field + + align:start position:0% + + + + align:start position:0% + +lines maybe look thidal from the point + + align:start position:0% +lines maybe look thidal from the point + + + align:start position:0% +lines maybe look thidal from the point +of view of the protons here so they're + + align:start position:0% +of view of the protons here so they're + + + align:start position:0% +of view of the protons here so they're +looping like + + align:start position:0% +looping like + + + align:start position:0% +looping like +this then as our protons go through here + + align:start position:0% +this then as our protons go through here + + + align:start position:0% +this then as our protons go through here +they're going to feel a + + align:start position:0% +they're going to feel a + + + align:start position:0% +they're going to feel a +force which is is equal to their charge + + align:start position:0% +force which is is equal to their charge + + + align:start position:0% +force which is is equal to their charge +I'll just write as + + align:start position:0% +I'll just write as + + + align:start position:0% +I'll just write as +e b cross + + align:start position:0% +e b cross + + + align:start position:0% +e b cross +B so they've got velocity in this + + align:start position:0% +B so they've got velocity in this + + + align:start position:0% +B so they've got velocity in this +direction for example here the magnetic + + align:start position:0% +direction for example here the magnetic + + + align:start position:0% +direction for example here the magnetic +field is pointing into the page and so + + align:start position:0% +field is pointing into the page and so + + + align:start position:0% +field is pointing into the page and so +the particles are going to feel a force + + align:start position:0% + + + + align:start position:0% + +upwards and these particles here are + + align:start position:0% +upwards and these particles here are + + + align:start position:0% +upwards and these particles here are +going to feel a force + + align:start position:0% +going to feel a force + + + align:start position:0% +going to feel a force +downwards like this and if we put some + + align:start position:0% +downwards like this and if we put some + + + align:start position:0% +downwards like this and if we put some +sort of detector some distance + + align:start position:0% + + + + align:start position:0% + +away + + align:start position:0% +away + + + align:start position:0% +away +we should see that our source which + + align:start position:0% +we should see that our source which + + + align:start position:0% +we should see that our source which +maybe was initially uniform so we had a + + align:start position:0% +maybe was initially uniform so we had a + + + align:start position:0% +maybe was initially uniform so we had a +uniform number of protons per centimet + + align:start position:0% +uniform number of protons per centimet + + + align:start position:0% +uniform number of protons per centimet +squared millimet squared now that + + align:start position:0% +squared millimet squared now that + + + align:start position:0% +squared millimet squared now that +uniform intensity is going to be changed + + align:start position:0% +uniform intensity is going to be changed + + + align:start position:0% +uniform intensity is going to be changed +so for example if we draw a little line + + align:start position:0% +so for example if we draw a little line + + + align:start position:0% +so for example if we draw a little line +drawing of intensity over the initial + + align:start position:0% +drawing of intensity over the initial + + + align:start position:0% +drawing of intensity over the initial +intensity in the absence of this + + align:start position:0% +intensity in the absence of this + + + align:start position:0% +intensity in the absence of this +plasma our intensity profile would just + + align:start position:0% +plasma our intensity profile would just + + + align:start position:0% +plasma our intensity profile would just +be one there's nothing to change the + + align:start position:0% +be one there's nothing to change the + + + align:start position:0% +be one there's nothing to change the +intensity but in this case here we can + + align:start position:0% +intensity but in this case here we can + + + align:start position:0% +intensity but in this case here we can +see that this magnetic field + + align:start position:0% +see that this magnetic field + + + align:start position:0% +see that this magnetic field +configuration has created a void it's + + align:start position:0% +configuration has created a void it's + + + align:start position:0% +configuration has created a void it's +pushed the protons outward effectively + + align:start position:0% +pushed the protons outward effectively + + + align:start position:0% +pushed the protons outward effectively +defocus them so we see that we're going + + align:start position:0% +defocus them so we see that we're going + + + align:start position:0% +defocus them so we see that we're going +to have relatively few protons in the + + align:start position:0% +to have relatively few protons in the + + + align:start position:0% +to have relatively few protons in the +middle we're going to have a pile up of + + align:start position:0% +middle we're going to have a pile up of + + + align:start position:0% +middle we're going to have a pile up of +protons at the edge and then far away + + align:start position:0% +protons at the edge and then far away + + + align:start position:0% +protons at the edge and then far away +from the plasma we're just going to have + + align:start position:0% +from the plasma we're just going to have + + + align:start position:0% +from the plasma we're just going to have +our standard fluence of one because + + align:start position:0% +our standard fluence of one because + + + align:start position:0% +our standard fluence of one because +there'll be some particles that just go + + align:start position:0% +there'll be some particles that just go + + + align:start position:0% +there'll be some particles that just go +around the edge here and you know in + + align:start position:0% +around the edge here and you know in + + + align:start position:0% +around the edge here and you know in +this little drawing it's can be nice and + + align:start position:0% +this little drawing it's can be nice and + + + align:start position:0% +this little drawing it's can be nice and +symetric so what this would look like if + + align:start position:0% +symetric so what this would look like if + + + align:start position:0% +symetric so what this would look like if +we looked front + + align:start position:0% +we looked front + + + align:start position:0% +we looked front +on potentially is a bright ring where we + + align:start position:0% +on potentially is a bright ring where we + + + align:start position:0% +on potentially is a bright ring where we +have lots of + + align:start position:0% + + + + align:start position:0% + +protons and a void in the + + align:start position:0% + + + + align:start position:0% + +center that's the magnetic fields we + + align:start position:0% +center that's the magnetic fields we + + + align:start position:0% +center that's the magnetic fields we +could also have a + + align:start position:0% +could also have a + + + align:start position:0% +could also have a +plasma that has electric Fields as well + + align:start position:0% +plasma that has electric Fields as well + + + align:start position:0% +plasma that has electric Fields as well +and although you know we think electric + + align:start position:0% +and although you know we think electric + + + align:start position:0% +and although you know we think electric +fields are quite + + align:start position:0% +fields are quite + + + align:start position:0% +fields are quite +small due to the B shielding on time + + align:start position:0% +small due to the B shielding on time + + + align:start position:0% +small due to the B shielding on time +scales in HD plasmas where these are + + align:start position:0% +scales in HD plasmas where these are + + + align:start position:0% +scales in HD plasmas where these are +often used the electric Fields can be + + align:start position:0% +often used the electric Fields can be + + + align:start position:0% +often used the electric Fields can be +relatively large because the plasma does + + align:start position:0% +relatively large because the plasma does + + + align:start position:0% +relatively large because the plasma does +not have to be quasy neutral so we could + + align:start position:0% +not have to be quasy neutral so we could + + + align:start position:0% +not have to be quasy neutral so we could +have some sort of electric field like + + align:start position:0% +have some sort of electric field like + + + align:start position:0% +have some sort of electric field like +this and then our electric field would + + align:start position:0% +this and then our electric field would + + + align:start position:0% +this and then our electric field would +also put a force on these + + align:start position:0% +also put a force on these + + + align:start position:0% +also put a force on these +protons in this case I've drawn it in + + align:start position:0% +protons in this case I've drawn it in + + + align:start position:0% +protons in this case I've drawn it in +the same way so the electric field is + + align:start position:0% +the same way so the electric field is + + + align:start position:0% +the same way so the electric field is +pushing the protons out from here so if + + align:start position:0% +pushing the protons out from here so if + + + align:start position:0% +pushing the protons out from here so if +I draw some more protons coming from a + + align:start position:0% +I draw some more protons coming from a + + + align:start position:0% +I draw some more protons coming from a +point source I draw some trajectories + + align:start position:0% +point source I draw some trajectories + + + align:start position:0% +point source I draw some trajectories +going into the plasma + + align:start position:0% +going into the plasma + + + align:start position:0% +going into the plasma +I'll have protons which are being bent + + align:start position:0% +I'll have protons which are being bent + + + align:start position:0% +I'll have protons which are being bent +upwards and + + align:start position:0% +upwards and + + + align:start position:0% +upwards and +downwards like this and so on my + + align:start position:0% +downwards like this and so on my + + + align:start position:0% +downwards like this and so on my +detector I could for example see a very + + align:start position:0% +detector I could for example see a very + + + align:start position:0% +detector I could for example see a very +similar pattern where I have a void in + + align:start position:0% +similar pattern where I have a void in + + + align:start position:0% +similar pattern where I have a void in +the middle I have some regions of + + align:start position:0% +the middle I have some regions of + + + align:start position:0% +the middle I have some regions of +increased fluence on the limbs and then + + align:start position:0% +increased fluence on the limbs and then + + + align:start position:0% +increased fluence on the limbs and then +I have a region where there's + + align:start position:0% +I have a region where there's + + + align:start position:0% +I have a region where there's +undisturbed fluence because I've got + + align:start position:0% +undisturbed fluence because I've got + + + align:start position:0% +undisturbed fluence because I've got +particles which are just going + + align:start position:0% + + + + align:start position:0% + +around so this is a technique called + + align:start position:0% +around so this is a technique called + + + align:start position:0% +around so this is a technique called +proton Imaging it's a way of Imaging + + align:start position:0% +proton Imaging it's a way of Imaging + + + align:start position:0% +proton Imaging it's a way of Imaging +electric and magnetic fields but of + + align:start position:0% +electric and magnetic fields but of + + + align:start position:0% +electric and magnetic fields but of +course uh it feels both the electric and + + align:start position:0% +course uh it feels both the electric and + + + align:start position:0% +course uh it feels both the electric and +the magnetic field so that's one + + align:start position:0% +the magnetic field so that's one + + + align:start position:0% +the magnetic field so that's one +fundamental limitation with it is that + + align:start position:0% +fundamental limitation with it is that + + + align:start position:0% +fundamental limitation with it is that +you're never quite sure whether your + + align:start position:0% +you're never quite sure whether your + + + align:start position:0% +you're never quite sure whether your +deflection is due to electric or + + align:start position:0% +deflection is due to electric or + + + align:start position:0% +deflection is due to electric or +magnetic + + align:start position:0% +magnetic + + + align:start position:0% +magnetic +fields there is a third form of proton + + align:start position:0% +fields there is a third form of proton + + + align:start position:0% +fields there is a third form of proton +Imaging which is technically called + + align:start position:0% +Imaging which is technically called + + + align:start position:0% +Imaging which is technically called +proton + + align:start position:0% + + + + align:start position:0% + +radiography on radiography the + + align:start position:0% +radiography on radiography the + + + align:start position:0% +radiography on radiography the +radiography here is to make you think + + align:start position:0% +radiography here is to make you think + + + align:start position:0% +radiography here is to make you think +about X-rays and x-ray radiography which + + align:start position:0% +about X-rays and x-ray radiography which + + + align:start position:0% +about X-rays and x-ray radiography which +is where you have your beam of + + align:start position:0% + + + + align:start position:0% + +particles and you have some very very + + align:start position:0% +particles and you have some very very + + + align:start position:0% +particles and you have some very very +dense plasma + + align:start position:0% + + + + align:start position:0% + +here and because it's so dense these + + align:start position:0% +here and because it's so dense these + + + align:start position:0% +here and because it's so dense these +particles don't stream through it and + + align:start position:0% +particles don't stream through it and + + + align:start position:0% +particles don't stream through it and +just feel the electrical magnetic fields + + align:start position:0% +just feel the electrical magnetic fields + + + align:start position:0% +just feel the electrical magnetic fields +the particles start scattering and + + align:start position:0% +the particles start scattering and + + + align:start position:0% +the particles start scattering and +colliding and maybe they never Escape + + align:start position:0% +colliding and maybe they never Escape + + + align:start position:0% +colliding and maybe they never Escape +out the other side and then on your + + align:start position:0% +out the other side and then on your + + + align:start position:0% +out the other side and then on your +detector you would have similar to an + + align:start position:0% +detector you would have similar to an + + + align:start position:0% +detector you would have similar to an +x-ray an image which for example has a + + align:start position:0% +x-ray an image which for example has a + + + align:start position:0% +x-ray an image which for example has a +region which is a void whether or no + + align:start position:0% +region which is a void whether or no + + + align:start position:0% +region which is a void whether or no +protons and that's because all the + + align:start position:0% +protons and that's because all the + + + align:start position:0% +protons and that's because all the +protons have been + + align:start position:0% + + + + align:start position:0% + +scattered so again this only + + align:start position:0% +scattered so again this only + + + align:start position:0% +scattered so again this only +happens at high + + align:start position:0% +happens at high + + + align:start position:0% +happens at high +densities at lower densities the + + align:start position:0% +densities at lower densities the + + + align:start position:0% +densities at lower densities the +particle should stream through um + + align:start position:0% +particle should stream through um + + + align:start position:0% +particle should stream through um +unfortunately a lot of people call this + + align:start position:0% +unfortunately a lot of people call this + + + align:start position:0% +unfortunately a lot of people call this +proton Imaging technique proton + + align:start position:0% +proton Imaging technique proton + + + align:start position:0% +proton Imaging technique proton +radiography because that's what it was + + align:start position:0% +radiography because that's what it was + + + align:start position:0% +radiography because that's what it was +initially called but it's not a + + align:start position:0% +initially called but it's not a + + + align:start position:0% +initially called but it's not a +radiographic technique radiography + + align:start position:0% +radiographic technique radiography + + + align:start position:0% +radiographic technique radiography +refers to like your beam being + + align:start position:0% +refers to like your beam being + + + align:start position:0% +refers to like your beam being +attenuated by density in the way so it's + + align:start position:0% +attenuated by density in the way so it's + + + align:start position:0% +attenuated by density in the way so it's +not really a right name but you'll see a + + align:start position:0% +not really a right name but you'll see a + + + align:start position:0% +not really a right name but you'll see a +lot of people call this proton + + align:start position:0% +lot of people call this proton + + + align:start position:0% +lot of people call this proton +radiography um some people have been + + align:start position:0% +radiography um some people have been + + + align:start position:0% +radiography um some people have been +trying to call it proton Imaging instead + + align:start position:0% +trying to call it proton Imaging instead + + + align:start position:0% +trying to call it proton Imaging instead +um even in the case where you don't have + + align:start position:0% +um even in the case where you don't have + + + align:start position:0% +um even in the case where you don't have +such a high density you may still end up + + align:start position:0% +such a high density you may still end up + + + align:start position:0% +such a high density you may still end up +with enough density in plasma that it + + align:start position:0% +with enough density in plasma that it + + + align:start position:0% +with enough density in plasma that it +will sort of knock a particle off course + + align:start position:0% +will sort of knock a particle off course + + + align:start position:0% +will sort of knock a particle off course +and that will lead to some sort of + + align:start position:0% +and that will lead to some sort of + + + align:start position:0% +and that will lead to some sort of +blurring so these weak + + align:start position:0% + + + + align:start position:0% + +collisions can lead to blurring of the + + align:start position:0% +collisions can lead to blurring of the + + + align:start position:0% +collisions can lead to blurring of the +image so you may still want to take into + + align:start position:0% +image so you may still want to take into + + + align:start position:0% +image so you may still want to take into +account the collisionality a little + + align:start position:0% + + + + align:start position:0% + +bit okay and the referen is for this + + align:start position:0% +bit okay and the referen is for this + + + align:start position:0% +bit okay and the referen is for this +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +are two + + align:start position:0% +are two + + + align:start position:0% +are two +papers first one is by + + align:start position:0% + + + + align:start position:0% + +kland you can find it in review of + + align:start position:0% +kland you can find it in review of + + + align:start position:0% +kland you can find it in review of +scientific instruments RSI from + + align:start position:0% +scientific instruments RSI from + + + align:start position:0% +scientific instruments RSI from +2012 a lot of the mathematics will be + + align:start position:0% +2012 a lot of the mathematics will be + + + align:start position:0% +2012 a lot of the mathematics will be +using as based off this paper and very + + align:start position:0% +using as based off this paper and very + + + align:start position:0% +using as based off this paper and very +recently there was a review article by + + align:start position:0% + + + + align:start position:0% + +schaer hasn't been published yet it's on + + align:start position:0% +schaer hasn't been published yet it's on + + + align:start position:0% +schaer hasn't been published yet it's on +the + + align:start position:0% +the + + + align:start position:0% +the +archive and that was published last year + + align:start position:0% +archive and that was published last year + + + align:start position:0% +archive and that was published last year +and this review article is really really + + align:start position:0% +and this review article is really really + + + align:start position:0% +and this review article is really really +good at the nitty-gritty of how proton + + align:start position:0% +good at the nitty-gritty of how proton + + + align:start position:0% +good at the nitty-gritty of how proton +rography is actually done and we'll talk + + align:start position:0% +rography is actually done and we'll talk + + + align:start position:0% +rography is actually done and we'll talk +an awful lot or a little bit at least + + align:start position:0% +an awful lot or a little bit at least + + + align:start position:0% +an awful lot or a little bit at least +about how these sources of protons are + + align:start position:0% +about how these sources of protons are + + + align:start position:0% +about how these sources of protons are +made later on but now for the first bit + + align:start position:0% +made later on but now for the first bit + + + align:start position:0% +made later on but now for the first bit +we're just going to assume there is some + + align:start position:0% +we're just going to assume there is some + + + align:start position:0% +we're just going to assume there is some +source of protons so before we get on to + + align:start position:0% +source of protons so before we get on to + + + align:start position:0% +source of protons so before we get on to +a more mathematical treatment of this + + align:start position:0% +a more mathematical treatment of this + + + align:start position:0% +a more mathematical treatment of this +does anyone have any questions + + align:start position:0% + + + + align:start position:0% + +yes yeah absolutely right so at the + + align:start position:0% +yes yeah absolutely right so at the + + + align:start position:0% +yes yeah absolutely right so at the +edges here where they have less distance + + align:start position:0% +edges here where they have less distance + + + align:start position:0% +edges here where they have less distance +travel through you could have something + + align:start position:0% +travel through you could have something + + + align:start position:0% +travel through you could have something +that gets knocked around but still gets + + align:start position:0% +that gets knocked around but still gets + + + align:start position:0% +that gets knocked around but still gets +through but maybe another particle + + align:start position:0% +through but maybe another particle + + + align:start position:0% +through but maybe another particle +traveling a very similar path doesn't + + align:start position:0% +traveling a very similar path doesn't + + + align:start position:0% +traveling a very similar path doesn't +get through and so you'd have you know + + align:start position:0% +get through and so you'd have you know + + + align:start position:0% +get through and so you'd have you know +gray scale you'd have few so just like + + align:start position:0% +gray scale you'd have few so just like + + + align:start position:0% +gray scale you'd have few so just like +was x-rays + + align:start position:0% +was x-rays + + + align:start position:0% +was x-rays +yeah other questions any questions + + align:start position:0% + + + + align:start position:0% + +online okay so mathematically this does + + align:start position:0% +online okay so mathematically this does + + + align:start position:0% +online okay so mathematically this does +look very similar to shog graphy but + + align:start position:0% +look very similar to shog graphy but + + + align:start position:0% +look very similar to shog graphy but +there are some differences so I'm going + + align:start position:0% +there are some differences so I'm going + + + align:start position:0% +there are some differences so I'm going +to go through the mathematics again so + + align:start position:0% +to go through the mathematics again so + + + align:start position:0% +to go through the mathematics again so +you may notice some similarities some + + align:start position:0% +you may notice some similarities some + + + align:start position:0% +you may notice some similarities some +differences in notation that's all okay + + align:start position:0% +differences in notation that's all okay + + + align:start position:0% +differences in notation that's all okay +um so we're going to start by making + + align:start position:0% +um so we're going to start by making + + + align:start position:0% +um so we're going to start by making +some + + align:start position:0% + + + + align:start position:0% + +assumptions our first assumption is that + + align:start position:0% +assumptions our first assumption is that + + + align:start position:0% +assumptions our first assumption is that +we have a point + + align:start position:0% + + + + align:start position:0% + +source in reality this means that if we + + align:start position:0% +source in reality this means that if we + + + align:start position:0% +source in reality this means that if we +have some Source size + + align:start position:0% +have some Source size + + + align:start position:0% +have some Source size +here which has uh a size say d source + + align:start position:0% +here which has uh a size say d source + + + align:start position:0% +here which has uh a size say d source +that has to be much much less than the + + align:start position:0% +that has to be much much less than the + + + align:start position:0% +that has to be much much less than the +length scale the size of our + + align:start position:0% +length scale the size of our + + + align:start position:0% +length scale the size of our +plasma because if that's true we have + + align:start position:0% +plasma because if that's true we have + + + align:start position:0% +plasma because if that's true we have +some finite Source size here and some + + align:start position:0% +some finite Source size here and some + + + align:start position:0% +some finite Source size here and some +very big plasma from the perspective of + + align:start position:0% +very big plasma from the perspective of + + + align:start position:0% +very big plasma from the perspective of +the plasma this will roughly be a point + + align:start position:0% +the plasma this will roughly be a point + + + align:start position:0% +the plasma this will roughly be a point +so we can make this more rigorous by + + align:start position:0% +so we can make this more rigorous by + + + align:start position:0% +so we can make this more rigorous by +introducing a dimensionless parameter + + align:start position:0% +introducing a dimensionless parameter + + + align:start position:0% +introducing a dimensionless parameter +and insisting that parameter is small um + + align:start position:0% +and insisting that parameter is small um + + + align:start position:0% +and insisting that parameter is small um +this is a pretty good + + align:start position:0% +this is a pretty good + + + align:start position:0% +this is a pretty good +approximation um the next thing we need + + align:start position:0% +approximation um the next thing we need + + + align:start position:0% +approximation um the next thing we need +to assume is a uniform + + align:start position:0% + + + + align:start position:0% + +B which is to say that we have the same + + align:start position:0% +B which is to say that we have the same + + + align:start position:0% +B which is to say that we have the same +number of protons coming through every + + align:start position:0% +number of protons coming through every + + + align:start position:0% +number of protons coming through every +little infimal solid angle unit here so + + align:start position:0% +little infimal solid angle unit here so + + + align:start position:0% +little infimal solid angle unit here so +that in the absence of any plasma when I + + align:start position:0% +that in the absence of any plasma when I + + + align:start position:0% +that in the absence of any plasma when I +put my detector here I do in fact get a + + align:start position:0% +put my detector here I do in fact get a + + + align:start position:0% +put my detector here I do in fact get a +nice uniform signal on it so I over i z + + align:start position:0% +nice uniform signal on it so I over i z + + + align:start position:0% +nice uniform signal on it so I over i z +is just one here if my signal is not + + align:start position:0% +is just one here if my signal is not + + + align:start position:0% +is just one here if my signal is not +uniform like this it complicates the + + align:start position:0% +uniform like this it complicates the + + + align:start position:0% +uniform like this it complicates the +interpretation it turns out you can do + + align:start position:0% +interpretation it turns out you can do + + + align:start position:0% +interpretation it turns out you can do +something with a non-uniform uh beam of + + align:start position:0% +something with a non-uniform uh beam of + + + align:start position:0% +something with a non-uniform uh beam of +protons but mathematically it's harder + + align:start position:0% +protons but mathematically it's harder + + + align:start position:0% +protons but mathematically it's harder +so we're going to insist on a uniform + + align:start position:0% +so we're going to insist on a uniform + + + align:start position:0% +so we're going to insist on a uniform +beam so we'll say the gradient of the + + align:start position:0% +beam so we'll say the gradient of the + + + align:start position:0% +beam so we'll say the gradient of the +beam intensity is equal to zero at + + align:start position:0% +beam intensity is equal to zero at + + + align:start position:0% +beam intensity is equal to zero at +least over the target over the plasma I + + align:start position:0% + + + + align:start position:0% + +guess okay third approximation we'll + + align:start position:0% +guess okay third approximation we'll + + + align:start position:0% +guess okay third approximation we'll +make is the paraxial approximation + + align:start position:0% +make is the paraxial approximation + + + align:start position:0% +make is the paraxial approximation +from geometric + + align:start position:0% + + + + align:start position:0% + +optics the paraxial approximation is + + align:start position:0% +optics the paraxial approximation is + + + align:start position:0% +optics the paraxial approximation is +basically saying that although these + + align:start position:0% +basically saying that although these + + + align:start position:0% +basically saying that although these +particles are following some path we can + + align:start position:0% +particles are following some path we can + + + align:start position:0% +particles are following some path we can +call DL our detector is relatively + + align:start position:0% +call DL our detector is relatively + + + align:start position:0% +call DL our detector is relatively +small and so most the particles are + + align:start position:0% +small and so most the particles are + + + align:start position:0% +small and so most the particles are +going almost parallel + + align:start position:0% +going almost parallel + + + align:start position:0% +going almost parallel +to DZ hat + + align:start position:0% + + + + align:start position:0% + +here so this means means we can + + align:start position:0% +here so this means means we can + + + align:start position:0% +here so this means means we can +approximate any path integrals as just + + align:start position:0% +approximate any path integrals as just + + + align:start position:0% +approximate any path integrals as just +integrals in The Zed Direction and this + + align:start position:0% +integrals in The Zed Direction and this + + + align:start position:0% +integrals in The Zed Direction and this +also means we can approximate angles + + align:start position:0% +also means we can approximate angles + + + align:start position:0% +also means we can approximate angles +like tan Alpha be approximately sin + + align:start position:0% +like tan Alpha be approximately sin + + + align:start position:0% +like tan Alpha be approximately sin +Alpha be approximately Alpha this makes + + align:start position:0% +Alpha be approximately Alpha this makes + + + align:start position:0% +Alpha be approximately Alpha this makes +the mathematics very easy as well and + + align:start position:0% +the mathematics very easy as well and + + + align:start position:0% +the mathematics very easy as well and +the final assumption we'll make is that + + align:start position:0% +the final assumption we'll make is that + + + align:start position:0% +the final assumption we'll make is that +our + + align:start position:0% + + + + align:start position:0% + +protons are test + + align:start position:0% +protons are test + + + align:start position:0% +protons are test +particles so you may have seen a test + + align:start position:0% +particles so you may have seen a test + + + align:start position:0% +particles so you may have seen a test +particle formulism + + align:start position:0% +particle formulism + + + align:start position:0% +particle formulism +ISM in some bits of plasma Theory the + + align:start position:0% +ISM in some bits of plasma Theory the + + + align:start position:0% +ISM in some bits of plasma Theory the +idea is your test particle merely + + align:start position:0% +idea is your test particle merely + + + align:start position:0% +idea is your test particle merely +experiences the fields inside your + + align:start position:0% +experiences the fields inside your + + + align:start position:0% +experiences the fields inside your +plasma it doesn't contribute to them so + + align:start position:0% +plasma it doesn't contribute to them so + + + align:start position:0% +plasma it doesn't contribute to them so +the fact that we have this beam of + + align:start position:0% +the fact that we have this beam of + + + align:start position:0% +the fact that we have this beam of +protons streaming through here we assume + + align:start position:0% +protons streaming through here we assume + + + align:start position:0% +protons streaming through here we assume +it has negligible perturbation on the + + align:start position:0% +it has negligible perturbation on the + + + align:start position:0% +it has negligible perturbation on the +plasma itself so we have no deflection + + align:start position:0% +plasma itself so we have no deflection + + + align:start position:0% +plasma itself so we have no deflection +for example + + align:start position:0% +for example + + + align:start position:0% +for example +between protons within the + + align:start position:0% + + + + align:start position:0% + +beam + + align:start position:0% +beam + + + align:start position:0% +beam +and this is a statement that the average + + align:start position:0% +and this is a statement that the average + + + align:start position:0% +and this is a statement that the average +potential that the protons are creating + + align:start position:0% +potential that the protons are creating + + + align:start position:0% +potential that the protons are creating +divided by their kinetic energy is much + + align:start position:0% +divided by their kinetic energy is much + + + align:start position:0% +divided by their kinetic energy is much +much less than one that is to say + + align:start position:0% +much less than one that is to say + + + align:start position:0% +much less than one that is to say +they're going so fast that even if they + + align:start position:0% +they're going so fast that even if they + + + align:start position:0% +they're going so fast that even if they +do feel a small electric field that + + align:start position:0% +do feel a small electric field that + + + align:start position:0% +do feel a small electric field that +deflects them slightly it's negligible + + align:start position:0% +deflects them slightly it's negligible + + + align:start position:0% +deflects them slightly it's negligible +because they're moving so fast it + + align:start position:0% +because they're moving so fast it + + + align:start position:0% +because they're moving so fast it +doesn't change their overall proton + + align:start position:0% +doesn't change their overall proton + + + align:start position:0% +doesn't change their overall proton +kinetic energy + + align:start position:0% +kinetic energy + + + align:start position:0% +kinetic energy +here okay any questions on assumption + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +always yeah yeah yeah the paraxial + + align:start position:0% +always yeah yeah yeah the paraxial + + + align:start position:0% +always yeah yeah yeah the paraxial +region takes care of that yeah exactly + + align:start position:0% +region takes care of that yeah exactly + + + align:start position:0% +region takes care of that yeah exactly +but you're right but like we're really + + align:start position:0% +but you're right but like we're really + + + align:start position:0% +but you're right but like we're really +talking about like less than a degree + + align:start position:0% +talking about like less than a degree + + + align:start position:0% +talking about like less than a degree +sub tenders is very very small + + align:start position:0% + + + + align:start position:0% + +yeah the only place is appeared so far + + align:start position:0% +yeah the only place is appeared so far + + + align:start position:0% +yeah the only place is appeared so far +as we've assumed that it's very very + + align:start position:0% +as we've assumed that it's very very + + + align:start position:0% +as we've assumed that it's very very +high so these protons tend to be and + + align:start position:0% +high so these protons tend to be and + + + align:start position:0% +high so these protons tend to be and +we'll get on to the generation mechanism + + align:start position:0% +we'll get on to the generation mechanism + + + align:start position:0% +we'll get on to the generation mechanism +but these tend to be like Mega electron + + align:start position:0% +but these tend to be like Mega electron + + + align:start position:0% +but these tend to be like Mega electron +volt energy protons here so they're much + + align:start position:0% +volt energy protons here so they're much + + + align:start position:0% +volt energy protons here so they're much +much uh um faster than any of the other + + align:start position:0% +much uh um faster than any of the other + + + align:start position:0% +much uh um faster than any of the other +particles in our system generally and + + align:start position:0% +particles in our system generally and + + + align:start position:0% +particles in our system generally and +because you know that the collisionality + + align:start position:0% +because you know that the collisionality + + + align:start position:0% +because you know that the collisionality +the meanf free path uh goes as I'm GNA + + align:start position:0% +the meanf free path uh goes as I'm GNA + + + align:start position:0% +the meanf free path uh goes as I'm GNA +get this right velocity + + align:start position:0% +get this right velocity + + + align:start position:0% +get this right velocity +cubed then these very fast particles + + align:start position:0% +cubed then these very fast particles + + + align:start position:0% +cubed then these very fast particles +here have a very long meanf free path + + align:start position:0% +here have a very long meanf free path + + + align:start position:0% +here have a very long meanf free path +their collisionality is very low so + + align:start position:0% +their collisionality is very low so + + + align:start position:0% +their collisionality is very low so +they're unlikely to collide with any + + align:start position:0% +they're unlikely to collide with any + + + align:start position:0% +they're unlikely to collide with any +particles in the to yeah we'll talk + + align:start position:0% +particles in the to yeah we'll talk + + + align:start position:0% +particles in the to yeah we'll talk +about that yeah no no no it's great yeah + + align:start position:0% +about that yeah no no no it's great yeah + + + align:start position:0% +about that yeah no no no it's great yeah +yeah um for the purposes of this we're + + align:start position:0% +yeah um for the purposes of this we're + + + align:start position:0% +yeah um for the purposes of this we're +going to do it in such a way that we + + align:start position:0% +going to do it in such a way that we + + + align:start position:0% +going to do it in such a way that we +will just solve for the end like there + + align:start position:0% +will just solve for the end like there + + + align:start position:0% +will just solve for the end like there +are some protons with part energy one + + align:start position:0% +are some protons with part energy one + + + align:start position:0% +are some protons with part energy one +and sub protons of energy two and our + + align:start position:0% +and sub protons of energy two and our + + + align:start position:0% +and sub protons of energy two and our +solution is separable and I guess that + + align:start position:0% +solution is separable and I guess that + + + align:start position:0% +solution is separable and I guess that +comes back to here the fact the beam + + align:start position:0% +comes back to here the fact the beam + + + align:start position:0% +comes back to here the fact the beam +doesn't interact with itself but we'll + + align:start position:0% +doesn't interact with itself but we'll + + + align:start position:0% +doesn't interact with itself but we'll +talk a lot about + + align:start position:0% + + + + align:start position:0% + +yeah they're much lighter and so they'll + + align:start position:0% +yeah they're much lighter and so they'll + + + align:start position:0% +yeah they're much lighter and so they'll +scatter more easily but people have + + align:start position:0% +scatter more easily but people have + + + align:start position:0% +scatter more easily but people have +started doing electron Imaging as well + + align:start position:0% +started doing electron Imaging as well + + + align:start position:0% +started doing electron Imaging as well +but then you sort of need like G beams + + align:start position:0% +but then you sort of need like G beams + + + align:start position:0% +but then you sort of need like G beams +and stuff like that so the protons are + + align:start position:0% + + + + align:start position:0% + +better I don't know enough about the + + align:start position:0% +better I don't know enough about the + + + align:start position:0% +better I don't know enough about the +Electron Beam techniques at the moment + + align:start position:0% +Electron Beam techniques at the moment + + + align:start position:0% +Electron Beam techniques at the moment +so a lot of I'm going to show you + + align:start position:0% +so a lot of I'm going to show you + + + align:start position:0% +so a lot of I'm going to show you +through is like very specific detectors + + align:start position:0% +through is like very specific detectors + + + align:start position:0% +through is like very specific detectors +that have been created for protons and I + + align:start position:0% +that have been created for protons and I + + + align:start position:0% +that have been created for protons and I +don't know whether that detective + + align:start position:0% +don't know whether that detective + + + align:start position:0% +don't know whether that detective +technology exists for electrons in the + + align:start position:0% +technology exists for electrons in the + + + align:start position:0% +technology exists for electrons in the +same way so yeah there another question + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% + + + + align:start position:0% + +yeah it's very hard to make a columnated + + align:start position:0% +yeah it's very hard to make a columnated + + + align:start position:0% +yeah it's very hard to make a columnated +beam of protons and when we talk about + + align:start position:0% +beam of protons and when we talk about + + + align:start position:0% +beam of protons and when we talk about +the generation mechanisms they tend to + + align:start position:0% +the generation mechanisms they tend to + + + align:start position:0% +the generation mechanisms they tend to +make Point sources or or things with + + align:start position:0% +make Point sources or or things with + + + align:start position:0% +make Point sources or or things with +very small spot sizes so it's a + + align:start position:0% +very small spot sizes so it's a + + + align:start position:0% +very small spot sizes so it's a +technological limitation yeah in the + + align:start position:0% +technological limitation yeah in the + + + align:start position:0% +technological limitation yeah in the +very early days people use particle + + align:start position:0% +very early days people use particle + + + align:start position:0% +very early days people use particle +accelerators to do this but although + + align:start position:0% +accelerators to do this but although + + + align:start position:0% +accelerators to do this but although +particle accelerators can accelerate a + + align:start position:0% +particle accelerators can accelerate a + + + align:start position:0% +particle accelerators can accelerate a +lot of particles to high energy um it's + + align:start position:0% +lot of particles to high energy um it's + + + align:start position:0% +lot of particles to high energy um it's +not enough particles on the time scale + + align:start position:0% +not enough particles on the time scale + + + align:start position:0% +not enough particles on the time scale +of these experiments these experiments + + align:start position:0% +of these experiments these experiments + + + align:start position:0% +of these experiments these experiments +are over in like a nanc and so you need + + align:start position:0% +are over in like a nanc and so you need + + + align:start position:0% +are over in like a nanc and so you need +a very very bright burst of protons and + + align:start position:0% +a very very bright burst of protons and + + + align:start position:0% +a very very bright burst of protons and +it turns out the techniques we have for + + align:start position:0% +it turns out the techniques we have for + + + align:start position:0% +it turns out the techniques we have for +making those bursts of protons make a + + align:start position:0% +making those bursts of protons make a + + + align:start position:0% +making those bursts of protons make a +nice point source yeah was there a + + align:start position:0% + + + + align:start position:0% + +question oh um when you say point source + + align:start position:0% +question oh um when you say point source + + + align:start position:0% +question oh um when you say point source +um you mean like just from a specific + + align:start position:0% +um you mean like just from a specific + + + align:start position:0% +um you mean like just from a specific +one location not like the point source + + align:start position:0% +one location not like the point source + + + align:start position:0% +one location not like the point source +hitting the plasma + + align:start position:0% +hitting the plasma + + + align:start position:0% +hitting the plasma +correct uh sorry could you say that a + + align:start position:0% +correct uh sorry could you say that a + + + align:start position:0% +correct uh sorry could you say that a +different way yeah um so the point + + align:start position:0% +different way yeah um so the point + + + align:start position:0% +different way yeah um so the point +source is the is the beams and when you + + align:start position:0% +source is the is the beams and when you + + + align:start position:0% +source is the is the beams and when you +were talking about the um particle + + align:start position:0% +were talking about the um particle + + + align:start position:0% +were talking about the um particle +acceleration uh said it was coming from + + align:start position:0% +acceleration uh said it was coming from + + + align:start position:0% +acceleration uh said it was coming from +a single area are they still doing that + + align:start position:0% +a single area are they still doing that + + + align:start position:0% +a single area are they still doing that +with like uh however else they're + + align:start position:0% +with like uh however else they're + + + align:start position:0% +with like uh however else they're +generating the protons these days um why + + align:start position:0% +generating the protons these days um why + + + align:start position:0% +generating the protons these days um why +don't we yeah we'll skip over that and + + align:start position:0% +don't we yeah we'll skip over that and + + + align:start position:0% +don't we yeah we'll skip over that and +we'll get to how the protons are being + + align:start position:0% +we'll get to how the protons are being + + + align:start position:0% +we'll get to how the protons are being +generated later and it might make a bit + + align:start position:0% +generated later and it might make a bit + + + align:start position:0% +generated later and it might make a bit +more sense so now you can imagine this + + align:start position:0% +more sense so now you can imagine this + + + align:start position:0% +more sense so now you can imagine this +as a point source that for example is um + + align:start position:0% +as a point source that for example is um + + + align:start position:0% +as a point source that for example is um +emitting protons in every direction I + + align:start position:0% +emitting protons in every direction I + + + align:start position:0% +emitting protons in every direction I +see right it just turns out our plasma + + align:start position:0% +see right it just turns out our plasma + + + align:start position:0% +see right it just turns out our plasma +is only in One Direction and so from the + + align:start position:0% +is only in One Direction and so from the + + + align:start position:0% +is only in One Direction and so from the +point of view of the plasma there's just + + align:start position:0% +point of view of the plasma there's just + + + align:start position:0% +point of view of the plasma there's just +a little point that sending protons it + + align:start position:0% +a little point that sending protons it + + + align:start position:0% +a little point that sending protons it +way but reality that's not exactly + + align:start position:0% +way but reality that's not exactly + + + align:start position:0% +way but reality that's not exactly +happening yeah I see okay thank you + + align:start position:0% +happening yeah I see okay thank you + + + align:start position:0% +happening yeah I see okay thank you +okay any other + + align:start position:0% + + + + align:start position:0% + +questions okay so let's set up the + + align:start position:0% +questions okay so let's set up the + + + align:start position:0% +questions okay so let's set up the +geometry of our + + align:start position:0% + + + + align:start position:0% + +problem so we've got our point + + align:start position:0% +problem so we've got our point + + + align:start position:0% +problem so we've got our point +source over here we've got our + + align:start position:0% +source over here we've got our + + + align:start position:0% +source over here we've got our +plasma here the distance between the two + + align:start position:0% +plasma here the distance between the two + + + align:start position:0% +plasma here the distance between the two +of these is lowercase + + align:start position:0% +of these is lowercase + + + align:start position:0% +of these is lowercase +L our plasma has has some characteristic + + align:start position:0% +L our plasma has has some characteristic + + + align:start position:0% +L our plasma has has some characteristic +size a here we have a + + align:start position:0% +size a here we have a + + + align:start position:0% +size a here we have a +detector some distance + + align:start position:0% +detector some distance + + + align:start position:0% +detector some distance +away and we'll call that + + align:start position:0% +away and we'll call that + + + align:start position:0% +away and we'll call that +distance capital + + align:start position:0% +distance capital + + + align:start position:0% +distance capital +L within the plasma we have a coordinate + + align:start position:0% +L within the plasma we have a coordinate + + + align:start position:0% +L within the plasma we have a coordinate +system and we label points within the + + align:start position:0% +system and we label points within the + + + align:start position:0% +system and we label points within the +plasma using the position Vector x0 here + + align:start position:0% +plasma using the position Vector x0 here + + + align:start position:0% +plasma using the position Vector x0 here +so if I say if I have a position with a + + align:start position:0% +so if I say if I have a position with a + + + align:start position:0% +so if I say if I have a position with a +Z subscript that's somewhere within the + + align:start position:0% +Z subscript that's somewhere within the + + + align:start position:0% +Z subscript that's somewhere within the +plasma and then on the + + align:start position:0% +plasma and then on the + + + align:start position:0% +plasma and then on the +detector I have a position Vector X so + + align:start position:0% +detector I have a position Vector X so + + + align:start position:0% +detector I have a position Vector X so +what we're going to be doing is looking + + align:start position:0% +what we're going to be doing is looking + + + align:start position:0% +what we're going to be doing is looking +at how the protons are deflected at + + align:start position:0% +at how the protons are deflected at + + + align:start position:0% +at how the protons are deflected at +position x0 and they will end up + + align:start position:0% +position x0 and they will end up + + + align:start position:0% +position x0 and they will end up +somewhere on the detector at X and what + + align:start position:0% +somewhere on the detector at X and what + + + align:start position:0% +somewhere on the detector at X and what +our job is therefore is to link what we + + align:start position:0% +our job is therefore is to link what we + + + align:start position:0% +our job is therefore is to link what we +see on our detector X back to the + + align:start position:0% +see on our detector X back to the + + + align:start position:0% +see on our detector X back to the +properties of the plasma at + + align:start position:0% +properties of the plasma at + + + align:start position:0% +properties of the plasma at +x0 and we can think of a + + align:start position:0% +x0 and we can think of a + + + align:start position:0% +x0 and we can think of a +proton coming out like this and within + + align:start position:0% +proton coming out like this and within + + + align:start position:0% +proton coming out like this and within +the plasma undergoing some + + align:start position:0% + + + + align:start position:0% + +deflection and it's deflected from its + + align:start position:0% +deflection and it's deflected from its + + + align:start position:0% +deflection and it's deflected from its +original trajectory by an angle Alpha + + align:start position:0% +original trajectory by an angle Alpha + + + align:start position:0% +original trajectory by an angle Alpha +and this Alpha in general can be a + + align:start position:0% +and this Alpha in general can be a + + + align:start position:0% +and this Alpha in general can be a +vector right so we can have an angle in + + align:start position:0% +vector right so we can have an angle in + + + align:start position:0% +vector right so we can have an angle in +this direction and we can have an angle + + align:start position:0% +this direction and we can have an angle + + + align:start position:0% +this direction and we can have an angle +in this direction here and we drawing it + + align:start position:0% +in this direction here and we drawing it + + + align:start position:0% +in this direction here and we drawing it +mostly in 1D but remember the particles + + align:start position:0% +mostly in 1D but remember the particles + + + align:start position:0% +mostly in 1D but remember the particles +be deflected in two Dimensions as + + align:start position:0% +be deflected in two Dimensions as + + + align:start position:0% +be deflected in two Dimensions as +well okay so from this symol geometry we + + align:start position:0% +well okay so from this symol geometry we + + + align:start position:0% +well okay so from this symol geometry we +can already write down what we're going + + align:start position:0% +can already write down what we're going + + + align:start position:0% +can already write down what we're going +to see on the detector X so + + align:start position:0% +to see on the detector X so + + + align:start position:0% +to see on the detector X so +X is a location of a proton which + + align:start position:0% +X is a location of a proton which + + + align:start position:0% +X is a location of a proton which +streamed through the point + + align:start position:0% +streamed through the point + + + align:start position:0% +streamed through the point +x0 and then there's a magnification + + align:start position:0% +x0 and then there's a magnification + + + align:start position:0% +x0 and then there's a magnification +Factor capital L over lowercase L this + + align:start position:0% +Factor capital L over lowercase L this + + + align:start position:0% +Factor capital L over lowercase L this +is just similar triangles this just says + + align:start position:0% +is just similar triangles this just says + + + align:start position:0% +is just similar triangles this just says +in the absence of any + + align:start position:0% + + + + align:start position:0% + +deflection I will have ended up at this + + align:start position:0% +deflection I will have ended up at this + + + align:start position:0% +deflection I will have ended up at this +Point here and that point is magnified + + align:start position:0% +Point here and that point is magnified + + + align:start position:0% +Point here and that point is magnified +because capital L and lowercase L are + + align:start position:0% +because capital L and lowercase L are + + + align:start position:0% +because capital L and lowercase L are +different so so far this is just what + + align:start position:0% +different so so far this is just what + + + align:start position:0% +different so so far this is just what +you get without any plasma when you put + + align:start position:0% +you get without any plasma when you put + + + align:start position:0% +you get without any plasma when you put +the plasma in of course you get some + + align:start position:0% +the plasma in of course you get some + + + align:start position:0% +the plasma in of course you get some +deflection Alpha and that Alpha is Times + + align:start position:0% +deflection Alpha and that Alpha is Times + + + align:start position:0% +deflection Alpha and that Alpha is Times +by the distance between the plasma and + + align:start position:0% +by the distance between the plasma and + + + align:start position:0% +by the distance between the plasma and +the detector here so again this is just + + align:start position:0% +the detector here so again this is just + + + align:start position:0% +the detector here so again this is just +geometry there's nothing to do with + + align:start position:0% +geometry there's nothing to do with + + + align:start position:0% +geometry there's nothing to do with +plasmas or protons or anything in + + align:start position:0% +plasmas or protons or anything in + + + align:start position:0% +plasmas or protons or anything in +there so just to clarify what of these + + align:start position:0% +there so just to clarify what of these + + + align:start position:0% +there so just to clarify what of these +terms are this is at the + + align:start position:0% +terms are this is at the + + + align:start position:0% +terms are this is at the +detector this is the + + align:start position:0% + + + + align:start position:0% + +object this term + + align:start position:0% +object this term + + + align:start position:0% +object this term +here is due to the Divergence of the + + align:start position:0% + + + + align:start position:0% + +beam we wouldn't have this term if we + + align:start position:0% +beam we wouldn't have this term if we + + + align:start position:0% +beam we wouldn't have this term if we +had a columnated beam like we had with + + align:start position:0% +had a columnated beam like we had with + + + align:start position:0% +had a columnated beam like we had with +lasers remember with the laser we + + align:start position:0% +lasers remember with the laser we + + + align:start position:0% +lasers remember with the laser we +started out with a load of rays which + + align:start position:0% +started out with a load of rays which + + + align:start position:0% +started out with a load of rays which +parallel and so this wouldn't have + + align:start position:0% +parallel and so this wouldn't have + + + align:start position:0% +parallel and so this wouldn't have +happened with a columnated beam but we + + align:start position:0% +happened with a columnated beam but we + + + align:start position:0% +happened with a columnated beam but we +don't have that we we got a point source + + align:start position:0% +don't have that we we got a point source + + + align:start position:0% +don't have that we we got a point source +we got a diverging Fe and then finally + + align:start position:0% +we got a diverging Fe and then finally + + + align:start position:0% +we got a diverging Fe and then finally +this is to do with the + + align:start position:0% + + + + align:start position:0% + +deflection so this is liography + + align:start position:0% + + + + align:start position:0% + +with a diverging + + align:start position:0% + + + + align:start position:0% + +beat + + align:start position:0% + + + + align:start position:0% + +okay any questions on + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +go + + align:start position:0% + + + + align:start position:0% + +typically we set up our system so L low + + align:start position:0% +typically we set up our system so L low + + + align:start position:0% +typically we set up our system so L low +uppercase L upon lowercase L is much + + align:start position:0% +uppercase L upon lowercase L is much + + + align:start position:0% +uppercase L upon lowercase L is much +much larger than one that is to say we + + align:start position:0% +much larger than one that is to say we + + + align:start position:0% +much larger than one that is to say we +have our source we have our + + align:start position:0% +have our source we have our + + + align:start position:0% +have our source we have our +plasma and then quite a long distance + + align:start position:0% +plasma and then quite a long distance + + + align:start position:0% +plasma and then quite a long distance +away we have our detector here remember + + align:start position:0% +away we have our detector here remember + + + align:start position:0% +away we have our detector here remember +this is lowercase L this is uppercase L + + align:start position:0% +this is lowercase L this is uppercase L + + + align:start position:0% +this is lowercase L this is uppercase L +um this is for two reasons firstly the + + align:start position:0% +um this is for two reasons firstly the + + + align:start position:0% +um this is for two reasons firstly the +plasmas tend to be very small and so by + + align:start position:0% +plasmas tend to be very small and so by + + + align:start position:0% +plasmas tend to be very small and so by +setting it up like this we get a massive + + align:start position:0% +setting it up like this we get a massive + + + align:start position:0% +setting it up like this we get a massive +magnification so because we've got these + + align:start position:0% +magnification so because we've got these + + + align:start position:0% +magnification so because we've got these +diverging protons here mapping out over + + align:start position:0% +diverging protons here mapping out over + + + align:start position:0% +diverging protons here mapping out over +there we're going to have a nice big + + align:start position:0% +there we're going to have a nice big + + + align:start position:0% +there we're going to have a nice big +image to look at you know so if this is + + align:start position:0% +image to look at you know so if this is + + + align:start position:0% +image to look at you know so if this is +only 100 microns across maybe on your + + align:start position:0% +only 100 microns across maybe on your + + + align:start position:0% +only 100 microns across maybe on your +image over here it's 10 millimeters + + align:start position:0% +image over here it's 10 millimeters + + + align:start position:0% +image over here it's 10 millimeters +across which is still pretty small but + + align:start position:0% +across which is still pretty small but + + + align:start position:0% +across which is still pretty small but +maybe you can actually see something + + align:start position:0% +maybe you can actually see something + + + align:start position:0% +maybe you can actually see something +under your detector the other reason is + + align:start position:0% +under your detector the other reason is + + + align:start position:0% +under your detector the other reason is +just practical you Cann put your + + align:start position:0% +just practical you Cann put your + + + align:start position:0% +just practical you Cann put your +detector very close to your plasma if + + align:start position:0% +detector very close to your plasma if + + + align:start position:0% +detector very close to your plasma if +this is something like a laser driven + + align:start position:0% +this is something like a laser driven + + + align:start position:0% +this is something like a laser driven +ICF implosion you really don't want to + + align:start position:0% +ICF implosion you really don't want to + + + align:start position:0% +ICF implosion you really don't want to +have your detector close because it will + + align:start position:0% +have your detector close because it will + + + align:start position:0% +have your detector close because it will +get trash you got to put it a long way + + align:start position:0% +get trash you got to put it a long way + + + align:start position:0% +get trash you got to put it a long way +away um so this is typically the regime + + align:start position:0% +away um so this is typically the regime + + + align:start position:0% +away um so this is typically the regime +that we work in and then + + align:start position:0% +that we work in and then + + + align:start position:0% +that we work in and then +as you can see up here that means that + + align:start position:0% +as you can see up here that means that + + + align:start position:0% +as you can see up here that means that +we have a term that looks + + align:start position:0% +we have a term that looks + + + align:start position:0% +we have a term that looks +like x0 1 plus capital L over lowercase + + align:start position:0% +like x0 1 plus capital L over lowercase + + + align:start position:0% +like x0 1 plus capital L over lowercase +L and we can just drop that term there + + align:start position:0% +L and we can just drop that term there + + + align:start position:0% +L and we can just drop that term there +as being small compared to the second + + align:start position:0% +as being small compared to the second + + + align:start position:0% +as being small compared to the second +term and we can then convert that + + align:start position:0% +term and we can then convert that + + + align:start position:0% +term and we can then convert that +equation so that it reads x equal + + align:start position:0% +equation so that it reads x equal + + + align:start position:0% +equation so that it reads x equal +L x0 upon lower case + + align:start position:0% +L x0 upon lower case + + + align:start position:0% +L x0 upon lower case +L + + align:start position:0% +L + + + align:start position:0% +L +plus + + align:start position:0% +plus + + + align:start position:0% +plus +Alpha I've just taken the capital L + + align:start position:0% +Alpha I've just taken the capital L + + + align:start position:0% +Alpha I've just taken the capital L +outside the brackets here now we have + + align:start position:0% +outside the brackets here now we have + + + align:start position:0% +outside the brackets here now we have +these two terms inside so this first + + align:start position:0% +these two terms inside so this first + + + align:start position:0% +these two terms inside so this first +term as I said is simply + + align:start position:0% + + + + align:start position:0% + +magnification very poorly written and + + align:start position:0% +magnification very poorly written and + + + align:start position:0% +magnification very poorly written and +this second term here is + + align:start position:0% + + + + align:start position:0% + +Distortion because the rays are being + + align:start position:0% +Distortion because the rays are being + + + align:start position:0% +Distortion because the rays are being +deflected we didn't have the Distortion + + align:start position:0% +deflected we didn't have the Distortion + + + align:start position:0% +deflected we didn't have the Distortion +this would just be an Imaging system + + align:start position:0% +this would just be an Imaging system + + + align:start position:0% +this would just be an Imaging system +with magnification because the rays are + + align:start position:0% +with magnification because the rays are + + + align:start position:0% +with magnification because the rays are +being deflected we have Distortion and + + align:start position:0% +being deflected we have Distortion and + + + align:start position:0% +being deflected we have Distortion and +because it's Distortion proton Imaging + + align:start position:0% +because it's Distortion proton Imaging + + + align:start position:0% +because it's Distortion proton Imaging +is not + + align:start position:0% +is not + + + align:start position:0% +is not +Imaging so perhaps they should call it + + align:start position:0% +Imaging so perhaps they should call it + + + align:start position:0% +Imaging so perhaps they should call it +proton deflectometry we can argue about + + align:start position:0% +proton deflectometry we can argue about + + + align:start position:0% +proton deflectometry we can argue about +the name for ages but this is not an + + align:start position:0% +the name for ages but this is not an + + + align:start position:0% +the name for ages but this is not an +Imaging technique like quotography if + + align:start position:0% +Imaging technique like quotography if + + + align:start position:0% +Imaging technique like quotography if +you see something on your detect + + align:start position:0% +you see something on your detect + + + align:start position:0% +you see something on your detect +it doesn't have a onetoone + + align:start position:0% +it doesn't have a onetoone + + + align:start position:0% +it doesn't have a onetoone +correspondence with what's going on in + + align:start position:0% +correspondence with what's going on in + + + align:start position:0% +correspondence with what's going on in +the plasma features are enhanced and + + align:start position:0% +the plasma features are enhanced and + + + align:start position:0% +the plasma features are enhanced and +enlarged the void that we were producing + + align:start position:0% +enlarged the void that we were producing + + + align:start position:0% +enlarged the void that we were producing +here that void for example is going to + + align:start position:0% +here that void for example is going to + + + align:start position:0% +here that void for example is going to +be larger than the real size of the + + align:start position:0% +be larger than the real size of the + + + align:start position:0% +be larger than the real size of the +plasma the protons are being pushed + + align:start position:0% +plasma the protons are being pushed + + + align:start position:0% +plasma the protons are being pushed +outwards + + align:start position:0% +outwards + + + align:start position:0% +outwards +okay so mathematically what we're doing + + align:start position:0% +okay so mathematically what we're doing + + + align:start position:0% +okay so mathematically what we're doing +is we're + + align:start position:0% +is we're + + + align:start position:0% +is we're +taking some area inside the plasma D s0 + + align:start position:0% +taking some area inside the plasma D s0 + + + align:start position:0% +taking some area inside the plasma D s0 +which has a certain number of prot + + align:start position:0% +which has a certain number of prot + + + align:start position:0% +which has a certain number of prot +going through + + align:start position:0% +going through + + + align:start position:0% +going through +it and we're mapping that out onto some + + align:start position:0% +it and we're mapping that out onto some + + + align:start position:0% +it and we're mapping that out onto some +area on the detector which does not have + + align:start position:0% +area on the detector which does not have + + + align:start position:0% +area on the detector which does not have +to be anywhere close to the same shape + + align:start position:0% +to be anywhere close to the same shape + + + align:start position:0% +to be anywhere close to the same shape +because of all the deflections going on + + align:start position:0% +because of all the deflections going on + + + align:start position:0% +because of all the deflections going on +inside + + align:start position:0% + + + + align:start position:0% + +here and that area is just the S so + + align:start position:0% +here and that area is just the S so + + + align:start position:0% +here and that area is just the S so +we're keeping our subscript notation + + align:start position:0% +we're keeping our subscript notation + + + align:start position:0% +we're keeping our subscript notation +here this is the object this is the + + align:start position:0% +here this is the object this is the + + + align:start position:0% +here this is the object this is the +image that's forming here and the way to + + align:start position:0% +image that's forming here and the way to + + + align:start position:0% +image that's forming here and the way to +link these is to say that DS is equal to + + align:start position:0% +link these is to say that DS is equal to + + + align:start position:0% +link these is to say that DS is equal to +the magnitude of this quantity + + align:start position:0% +the magnitude of this quantity + + + align:start position:0% +the magnitude of this quantity +D at + + align:start position:0% +D at + + + align:start position:0% +D at +x0 times DS and this is a quantity that + + align:start position:0% +x0 times DS and this is a quantity that + + + align:start position:0% +x0 times DS and this is a quantity that +some of you may know it's the + + align:start position:0% + + + + align:start position:0% + +Jacobian and it has the + + align:start position:0% +Jacobian and it has the + + + align:start position:0% +Jacobian and it has the +form partial X and Y over + + align:start position:0% +form partial X and Y over + + + align:start position:0% +form partial X and Y over +partial + + align:start position:0% +partial + + + align:start position:0% +partial +x0 y z of course we haven't told you how + + align:start position:0% +x0 y z of course we haven't told you how + + + align:start position:0% +x0 y z of course we haven't told you how +to calculate that yet but it's going to + + align:start position:0% +to calculate that yet but it's going to + + + align:start position:0% +to calculate that yet but it's going to +be related to this here so this is just + + align:start position:0% +be related to this here so this is just + + + align:start position:0% +be related to this here so this is just +a general statement when you're mapping + + align:start position:0% +a general statement when you're mapping + + + align:start position:0% +a general statement when you're mapping +some area to another area you can do it + + align:start position:0% +some area to another area you can do it + + + align:start position:0% +some area to another area you can do it +using this Jacobian transform um and the + + align:start position:0% +using this Jacobian transform um and the + + + align:start position:0% +using this Jacobian transform um and the +exact way Jacobian transform Works will + + align:start position:0% +exact way Jacobian transform Works will + + + align:start position:0% +exact way Jacobian transform Works will +be related to this and we'll Solve IT + + align:start position:0% +be related to this and we'll Solve IT + + + align:start position:0% +be related to this and we'll Solve IT +explicitly uh sorry the left hand side + + align:start position:0% +explicitly uh sorry the left hand side + + + align:start position:0% +explicitly uh sorry the left hand side +here thank you yes didn't make much + + align:start position:0% +here thank you yes didn't make much + + + align:start position:0% +here thank you yes didn't make much +sense I said it and I guess this is a + + align:start position:0% +sense I said it and I guess this is a + + + align:start position:0% +sense I said it and I guess this is a +vector again but here I've written out + + align:start position:0% +vector again but here I've written out + + + align:start position:0% +vector again but here I've written out +explicitly in terms of the X and Y + + align:start position:0% +explicitly in terms of the X and Y + + + align:start position:0% +explicitly in terms of the X and Y +components um here I just put in this + + align:start position:0% +components um here I just put in this + + + align:start position:0% +components um here I just put in this +more compact Vector notation okay + + align:start position:0% + + + + align:start position:0% + +questions okay we're going to assume + + align:start position:0% +questions okay we're going to assume + + + align:start position:0% +questions okay we're going to assume +that we can serve particles maybe this + + align:start position:0% +that we can serve particles maybe this + + + align:start position:0% +that we can serve particles maybe this +was another assumption up here that none + + align:start position:0% +was another assumption up here that none + + + align:start position:0% +was another assumption up here that none +of our particles are scattered lost but + + align:start position:0% +of our particles are scattered lost but + + + align:start position:0% +of our particles are scattered lost but +if we conserve the number of + + align:start position:0% + + + + align:start position:0% + +protons then the intensity on our + + align:start position:0% +protons then the intensity on our + + + align:start position:0% +protons then the intensity on our +detector is going to be equal to the + + align:start position:0% +detector is going to be equal to the + + + align:start position:0% +detector is going to be equal to the +intensity going through the object + + align:start position:0% +intensity going through the object + + + align:start position:0% +intensity going through the object +divided by this + + align:start position:0% +divided by this + + + align:start position:0% +divided by this +jacobia is equivalent statement that + + align:start position:0% +jacobia is equivalent statement that + + + align:start position:0% +jacobia is equivalent statement that +we're conserving the area of this + + align:start position:0% +we're conserving the area of this + + + align:start position:0% +we're conserving the area of this +Jacobian transformation here we're + + align:start position:0% +Jacobian transformation here we're + + + align:start position:0% +Jacobian transformation here we're +conserving intensity here and this + + align:start position:0% + + + + align:start position:0% + +trovian is going to be equal to l^2 + + align:start position:0% +trovian is going to be equal to l^2 + + + align:start position:0% +trovian is going to be equal to l^2 +capital l s upon lowercase l s times 1 + + align:start position:0% +capital l s upon lowercase l s times 1 + + + align:start position:0% +capital l s upon lowercase l s times 1 +plus then we start doing a tailor + + align:start position:0% +plus then we start doing a tailor + + + align:start position:0% +plus then we start doing a tailor +expansion uh of this uh equation here + + align:start position:0% +expansion uh of this uh equation here + + + align:start position:0% +expansion uh of this uh equation here +L + + align:start position:0% +L + + + align:start position:0% +L +gradient of alpha plus l s + + align:start position:0% + + + + align:start position:0% + +partial alpha x component partial + + align:start position:0% +partial alpha x component partial + + + align:start position:0% +partial alpha x component partial +x0 partial alpha y component partial y z + + align:start position:0% +x0 partial alpha y component partial y z + + + align:start position:0% +x0 partial alpha y component partial y z +and then another term which follows + + align:start position:0% +and then another term which follows + + + align:start position:0% +and then another term which follows +symmetrically from this which is minus + + align:start position:0% +symmetrically from this which is minus + + + align:start position:0% +symmetrically from this which is minus +partial alpha x component partial y0 + + align:start position:0% +partial alpha x component partial y0 + + + align:start position:0% +partial alpha x component partial y0 +partial alpha y component partial + + align:start position:0% +partial alpha y component partial + + + align:start position:0% +partial alpha y component partial +x0 plus some other terms that we're + + align:start position:0% +x0 plus some other terms that we're + + + align:start position:0% +x0 plus some other terms that we're +going to drop as being small here + + align:start position:0% +going to drop as being small here + + + align:start position:0% +going to drop as being small here +there's probably a more compact Vector + + align:start position:0% +there's probably a more compact Vector + + + align:start position:0% +there's probably a more compact Vector +notation for this but I just wanted to + + align:start position:0% +notation for this but I just wanted to + + + align:start position:0% +notation for this but I just wanted to +write it out more explicitly this one is + + align:start position:0% +write it out more explicitly this one is + + + align:start position:0% +write it out more explicitly this one is +clearly just partial alpha x partial X + + align:start position:0% +clearly just partial alpha x partial X + + + align:start position:0% +clearly just partial alpha x partial X +Plus partial alpha y partial Y and these + + align:start position:0% +Plus partial alpha y partial Y and these + + + align:start position:0% +Plus partial alpha y partial Y and these +are all zero subscripts because we're + + align:start position:0% +are all zero subscripts because we're + + + align:start position:0% +are all zero subscripts because we're +doing the derivative inside the plasma + + align:start position:0% +doing the derivative inside the plasma + + + align:start position:0% +doing the derivative inside the plasma +so this is looking at derivatives of how + + align:start position:0% +so this is looking at derivatives of how + + + align:start position:0% +so this is looking at derivatives of how +the angle changes inside + + align:start position:0% + + + + align:start position:0% + +the okay so if you can calculate your + + align:start position:0% +the okay so if you can calculate your + + + align:start position:0% +the okay so if you can calculate your +angle Alpha and you might think I can do + + align:start position:0% +angle Alpha and you might think I can do + + + align:start position:0% +angle Alpha and you might think I can do +that if I know the Electric magnetic + + align:start position:0% +that if I know the Electric magnetic + + + align:start position:0% +that if I know the Electric magnetic +fields in my system and you be right + + align:start position:0% +fields in my system and you be right + + + align:start position:0% +fields in my system and you be right +then you can now calculate how alpha + + align:start position:0% +then you can now calculate how alpha + + + align:start position:0% +then you can now calculate how alpha +changes within the plasma how the + + align:start position:0% +changes within the plasma how the + + + align:start position:0% +changes within the plasma how the +protons get distorted and now you can + + align:start position:0% +protons get distorted and now you can + + + align:start position:0% +protons get distorted and now you can +work out what your intensity is compared + + align:start position:0% +work out what your intensity is compared + + + align:start position:0% +work out what your intensity is compared +to your initial intensity and it turns + + align:start position:0% +to your initial intensity and it turns + + + align:start position:0% +to your initial intensity and it turns +out that the sorts of images you get out + + align:start position:0% +out that the sorts of images you get out + + + align:start position:0% +out that the sorts of images you get out +of here there's a very useful + + align:start position:0% +of here there's a very useful + + + align:start position:0% +of here there's a very useful +dimensionless parameter that you can + + align:start position:0% +dimensionless parameter that you can + + + align:start position:0% +dimensionless parameter that you can +write down to characterize the different + + align:start position:0% +write down to characterize the different + + + align:start position:0% +write down to characterize the different +images and this parameter is called the + + align:start position:0% +images and this parameter is called the + + + align:start position:0% +images and this parameter is called the +contrast + + align:start position:0% +contrast + + + align:start position:0% +contrast +parameter + + align:start position:0% + + + + align:start position:0% + +and it's written as Mu and it is defined + + align:start position:0% +and it's written as Mu and it is defined + + + align:start position:0% +and it's written as Mu and it is defined +as lowercase L over a lowercase L was + + align:start position:0% +as lowercase L over a lowercase L was + + + align:start position:0% +as lowercase L over a lowercase L was +the distance from the point source to + + align:start position:0% +the distance from the point source to + + + align:start position:0% +the distance from the point source to +the plasma and a is the size of our + + align:start position:0% +the plasma and a is the size of our + + + align:start position:0% +the plasma and a is the size of our +plasma times the modulus of this + + align:start position:0% +plasma times the modulus of this + + + align:start position:0% +plasma times the modulus of this +deflection angle Vector so the size of + + align:start position:0% +deflection angle Vector so the size of + + + align:start position:0% +deflection angle Vector so the size of +this + + align:start position:0% + + + + align:start position:0% + +deflection and it turns out if you're in + + align:start position:0% +deflection and it turns out if you're in + + + align:start position:0% +deflection and it turns out if you're in +a r regime where this parameter is much + + align:start position:0% +a r regime where this parameter is much + + + align:start position:0% +a r regime where this parameter is much +much less than one then you find out + + align:start position:0% +much less than one then you find out + + + align:start position:0% +much less than one then you find out +that your D your Jacobian here is + + align:start position:0% +that your D your Jacobian here is + + + align:start position:0% +that your D your Jacobian here is +approximately constant and so your + + align:start position:0% +approximately constant and so your + + + align:start position:0% +approximately constant and so your +intensity is approximately constant so + + align:start position:0% +intensity is approximately constant so + + + align:start position:0% +intensity is approximately constant so +we talked about this with shog graphy + + align:start position:0% +we talked about this with shog graphy + + + align:start position:0% +we talked about this with shog graphy +this is a regime where we only have + + align:start position:0% +this is a regime where we only have + + + align:start position:0% +this is a regime where we only have +small intensity variations and when you + + align:start position:0% +small intensity variations and when you + + + align:start position:0% +small intensity variations and when you +have small intensity variations you have + + align:start position:0% +have small intensity variations you have + + + align:start position:0% +have small intensity variations you have +a chance of being able to undo this + + align:start position:0% +a chance of being able to undo this + + + align:start position:0% +a chance of being able to undo this +transformation and work out what the was + + align:start position:0% +transformation and work out what the was + + + align:start position:0% +transformation and work out what the was +and therefore work out something about + + align:start position:0% +and therefore work out something about + + + align:start position:0% +and therefore work out something about +your plasma but if you have a contrast + + align:start position:0% +your plasma but if you have a contrast + + + align:start position:0% +your plasma but if you have a contrast +parameter where mu is about one this + + align:start position:0% +parameter where mu is about one this + + + align:start position:0% +parameter where mu is about one this +corresponds to having your + + align:start position:0% +corresponds to having your + + + align:start position:0% +corresponds to having your +Jacobian uh with + + align:start position:0% +Jacobian uh with + + + align:start position:0% +Jacobian uh with +singularities or with zeros in + + align:start position:0% +singularities or with zeros in + + + align:start position:0% +singularities or with zeros in +it you can see if you have zeros in D + + align:start position:0% +it you can see if you have zeros in D + + + align:start position:0% +it you can see if you have zeros in D +then all of a sudden you're going to + + align:start position:0% +then all of a sudden you're going to + + + align:start position:0% +then all of a sudden you're going to +have your initial intensity over zero + + align:start position:0% +have your initial intensity over zero + + + align:start position:0% +have your initial intensity over zero +your intensity will go to some very very + + align:start position:0% +your intensity will go to some very very + + + align:start position:0% +your intensity will go to some very very +large number and these are the cotic + + align:start position:0% +large number and these are the cotic + + + align:start position:0% +large number and these are the cotic +patterns we talked about in + + align:start position:0% +patterns we talked about in + + + align:start position:0% +patterns we talked about in +chirography + + align:start position:0% + + + + align:start position:0% + +uh yeah I wish I had some more space but + + align:start position:0% +uh yeah I wish I had some more space but + + + align:start position:0% +uh yeah I wish I had some more space but +I don't so well actually uh maybe I have + + align:start position:0% +I don't so well actually uh maybe I have + + + align:start position:0% +I don't so well actually uh maybe I have +just about enough space so in this case + + align:start position:0% +just about enough space so in this case + + + align:start position:0% +just about enough space so in this case +here you can show that your intensity on + + align:start position:0% +here you can show that your intensity on + + + align:start position:0% +here you can show that your intensity on +your detector is equal to your Source + + align:start position:0% +your detector is equal to your Source + + + align:start position:0% +your detector is equal to your Source +intensity uh times one minus + + align:start position:0% +intensity uh times one minus + + + align:start position:0% +intensity uh times one minus +L + + align:start position:0% +L + + + align:start position:0% +L +Divergence of alpha like this and this + + align:start position:0% +Divergence of alpha like this and this + + + align:start position:0% +Divergence of alpha like this and this +is equivalent the equation we came up + + align:start position:0% +is equivalent the equation we came up + + + align:start position:0% +is equivalent the equation we came up +with ography where we've implicitly + + align:start position:0% +with ography where we've implicitly + + + align:start position:0% +with ography where we've implicitly +assumed that all of these terms are very + + align:start position:0% +assumed that all of these terms are very + + + align:start position:0% +assumed that all of these terms are very +small if you look here our contrast + + align:start position:0% +small if you look here our contrast + + + align:start position:0% +small if you look here our contrast +parameter has an L an alpha and an a + + align:start position:0% +parameter has an L an alpha and an a + + + align:start position:0% +parameter has an L an alpha and an a +we've got an L an alpha and this + + align:start position:0% +we've got an L an alpha and this + + + align:start position:0% +we've got an L an alpha and this +gradient is going to be on the order + + align:start position:0% +gradient is going to be on the order + + + align:start position:0% +gradient is going to be on the order +of the size of the plasma like that so + + align:start position:0% +of the size of the plasma like that so + + + align:start position:0% +of the size of the plasma like that so +we've implicitly assumed this contrast + + align:start position:0% +we've implicitly assumed this contrast + + + align:start position:0% +we've implicitly assumed this contrast +parameter is small in order to get this + + align:start position:0% +parameter is small in order to get this + + + align:start position:0% +parameter is small in order to get this +solution and so what we see is we have + + align:start position:0% +solution and so what we see is we have + + + align:start position:0% +solution and so what we see is we have +small variations in intensity it's one + + align:start position:0% +small variations in intensity it's one + + + align:start position:0% +small variations in intensity it's one +minus a very small + + align:start position:0% +minus a very small + + + align:start position:0% +minus a very small +number if we have zeros here then we + + align:start position:0% +number if we have zeros here then we + + + align:start position:0% +number if we have zeros here then we +actually have to solve fully for + + align:start position:0% + + + + align:start position:0% + +d for D everywhere inside the + + align:start position:0% +d for D everywhere inside the + + + align:start position:0% +d for D everywhere inside the +plasma and this is where we start + + align:start position:0% +plasma and this is where we start + + + align:start position:0% +plasma and this is where we start +getting these singularities so I got + + align:start position:0% +getting these singularities so I got + + + align:start position:0% +getting these singularities so I got +some + + align:start position:0% + + + + align:start position:0% + +space so we have D equals zero we get + + align:start position:0% +space so we have D equals zero we get + + + align:start position:0% +space so we have D equals zero we get +singularities in + + align:start position:0% + + + + align:start position:0% + +I I is equal to i z over the size of + + align:start position:0% +I I is equal to i z over the size of + + + align:start position:0% +I I is equal to i z over the size of +D and this corresponds to proton + + align:start position:0% +D and this corresponds to proton + + + align:start position:0% +D and this corresponds to proton +trajectories Crossing so we have + + align:start position:0% +trajectories Crossing so we have + + + align:start position:0% +trajectories Crossing so we have +deflection within the + + align:start position:0% +deflection within the + + + align:start position:0% +deflection within the +plasma and we have two protons which + + align:start position:0% +plasma and we have two protons which + + + align:start position:0% +plasma and we have two protons which +take different paths but end up at the + + align:start position:0% +take different paths but end up at the + + + align:start position:0% +take different paths but end up at the +same place and if you can imagine if + + align:start position:0% +same place and if you can imagine if + + + align:start position:0% +same place and if you can imagine if +there's multiple of these happening you + + align:start position:0% +there's multiple of these happening you + + + align:start position:0% +there's multiple of these happening you +end up with a huge amount of fluence in + + align:start position:0% +end up with a huge amount of fluence in + + + align:start position:0% +end up with a huge amount of fluence in +one spot and so you get very very high + + align:start position:0% + + + + align:start position:0% + +intensity and this is usually called + + align:start position:0% + + + + align:start position:0% + +acostic so these cotic features are very + + align:start position:0% +acostic so these cotic features are very + + + align:start position:0% +acostic so these cotic features are very +very strong you can see them very very + + align:start position:0% +very strong you can see them very very + + + align:start position:0% +very strong you can see them very very +easily um but they mean that there is no + + align:start position:0% +easily um but they mean that there is no + + + align:start position:0% +easily um but they mean that there is no +longer a unique reconstruction so we can + + align:start position:0% +longer a unique reconstruction so we can + + + align:start position:0% +longer a unique reconstruction so we can +no longer uniquely take our modulation + + align:start position:0% +no longer uniquely take our modulation + + + align:start position:0% +no longer uniquely take our modulation +intensity I on our detector and work out + + align:start position:0% +intensity I on our detector and work out + + + align:start position:0% +intensity I on our detector and work out +the properties of the plasma through + + align:start position:0% + + + + align:start position:0% + +D so we want to avoid being in this + + align:start position:0% + + + + align:start position:0% + +regime avoid being in the regime where + + align:start position:0% +regime avoid being in the regime where + + + align:start position:0% +regime avoid being in the regime where +mu is approximately one and to avoid + + align:start position:0% +mu is approximately one and to avoid + + + align:start position:0% +mu is approximately one and to avoid +being in that regime we just have to + + align:start position:0% +being in that regime we just have to + + + align:start position:0% +being in that regime we just have to +look at the definition of mu and try and + + align:start position:0% +look at the definition of mu and try and + + + align:start position:0% +look at the definition of mu and try and +make it as small as possible so we want + + align:start position:0% +make it as small as possible so we want + + + align:start position:0% +make it as small as possible so we want +l over a much much less than one so + + align:start position:0% +l over a much much less than one so + + + align:start position:0% +l over a much much less than one so +again that's the distance between the + + align:start position:0% +again that's the distance between the + + + align:start position:0% +again that's the distance between the +source I've got it here + + align:start position:0% + + + + align:start position:0% + +already The Source distance Le plasma is + + align:start position:0% +already The Source distance Le plasma is + + + align:start position:0% +already The Source distance Le plasma is +L and the size of the plasma is a so + + align:start position:0% +L and the size of the plasma is a so + + + align:start position:0% +L and the size of the plasma is a so +obviously in this case I haven't + + align:start position:0% +obviously in this case I haven't + + + align:start position:0% +obviously in this case I haven't +succeeded L A is roughly one but I could + + align:start position:0% +succeeded L A is roughly one but I could + + + align:start position:0% +succeeded L A is roughly one but I could +put the source much further away and + + align:start position:0% +put the source much further away and + + + align:start position:0% +put the source much further away and +then L A would be much smaller and that + + align:start position:0% +then L A would be much smaller and that + + + align:start position:0% +then L A would be much smaller and that +would help me make mu smaller and and + + align:start position:0% +would help me make mu smaller and and + + + align:start position:0% +would help me make mu smaller and and +the other thing I can do is + + align:start position:0% +the other thing I can do is + + + align:start position:0% +the other thing I can do is +have the size of alpha be much much less + + align:start position:0% +have the size of alpha be much much less + + + align:start position:0% +have the size of alpha be much much less +than one so that's effectively insisting + + align:start position:0% +than one so that's effectively insisting + + + align:start position:0% +than one so that's effectively insisting +that my deflections are small now for a + + align:start position:0% +that my deflections are small now for a + + + align:start position:0% +that my deflections are small now for a +given plasma there are some given + + align:start position:0% +given plasma there are some given + + + align:start position:0% +given plasma there are some given +electric and magnetic fields I can't + + align:start position:0% +electric and magnetic fields I can't + + + align:start position:0% +electric and magnetic fields I can't +just ask the deflections to be small + + align:start position:0% +just ask the deflections to be small + + + align:start position:0% +just ask the deflections to be small +what I can do however as we'll see in a + + align:start position:0% +what I can do however as we'll see in a + + + align:start position:0% +what I can do however as we'll see in a +moment is use very fast particles or + + align:start position:0% +moment is use very fast particles or + + + align:start position:0% +moment is use very fast particles or +fast + + align:start position:0% + + + + align:start position:0% + +protons because if we make the protons + + align:start position:0% +protons because if we make the protons + + + align:start position:0% +protons because if we make the protons +go very fast they def become smaller and + + align:start position:0% +go very fast they def become smaller and + + + align:start position:0% +go very fast they def become smaller and +smaller as we're about to + + align:start position:0% +smaller as we're about to + + + align:start position:0% +smaller as we're about to +show okay now none of this really has + + align:start position:0% +show okay now none of this really has + + + align:start position:0% +show okay now none of this really has +talked about protons at any point all of + + align:start position:0% +talked about protons at any point all of + + + align:start position:0% +talked about protons at any point all of +this applies just the same theography + + align:start position:0% +this applies just the same theography + + + align:start position:0% +this applies just the same theography +we're just thinking about particles or + + align:start position:0% +we're just thinking about particles or + + + align:start position:0% +we're just thinking about particles or +rays that get deflected going through a + + align:start position:0% +rays that get deflected going through a + + + align:start position:0% +rays that get deflected going through a +plasma and we've sort of put some + + align:start position:0% +plasma and we've sort of put some + + + align:start position:0% +plasma and we've sort of put some +geometric formalism on top of us or on + + align:start position:0% +geometric formalism on top of us or on + + + align:start position:0% +geometric formalism on top of us or on +top of it to tell us what we expect to + + align:start position:0% +top of it to tell us what we expect to + + + align:start position:0% +top of it to tell us what we expect to +see on our + + align:start position:0% +see on our + + + align:start position:0% +see on our +detector so bearing that in mind any + + align:start position:0% +detector so bearing that in mind any + + + align:start position:0% +detector so bearing that in mind any +questions before we go on and actually + + align:start position:0% +questions before we go on and actually + + + align:start position:0% +questions before we go on and actually +talk about protons and plasmas and + + align:start position:0% +talk about protons and plasmas and + + + align:start position:0% +talk about protons and plasmas and +electromag + + align:start position:0% + + + + align:start position:0% + +I saw some folks still writing but yeah + + align:start position:0% + + + + align:start position:0% + +question oh looks like I got it the + + align:start position:0% +question oh looks like I got it the + + + align:start position:0% +question oh looks like I got it the +wrong way around didn't I yes L needs to + + align:start position:0% +wrong way around didn't I yes L needs to + + + align:start position:0% +wrong way around didn't I yes L needs to +be much less + + align:start position:0% + + + + align:start position:0% + +than I + + align:start position:0% + + + + align:start position:0% + +mean like your + + align:start position:0% +mean like your + + + align:start position:0% +mean like your +plasma no I I can still do that if the + + align:start position:0% +plasma no I I can still do that if the + + + align:start position:0% +plasma no I I can still do that if the +plasma is spherical right because if I I + + align:start position:0% +plasma is spherical right because if I I + + + align:start position:0% +plasma is spherical right because if I I +have for example a source here and a + + align:start position:0% +have for example a source here and a + + + align:start position:0% +have for example a source here and a +spherical plasma over here this is a and + + align:start position:0% +spherical plasma over here this is a and + + + align:start position:0% +spherical plasma over here this is a and +this is L and it's pretty clear that L + + align:start position:0% +this is L and it's pretty clear that L + + + align:start position:0% +this is L and it's pretty clear that L +over a is much greater than + + align:start position:0% +over a is much greater than + + + align:start position:0% +over a is much greater than +one yeah so + + align:start position:0% +one yeah so + + + align:start position:0% +one yeah so +I well no no no no this is the condition + + align:start position:0% +I well no no no no this is the condition + + + align:start position:0% +I well no no no no this is the condition +that you want what I said earlier is + + align:start position:0% +that you want what I said earlier is + + + align:start position:0% +that you want what I said earlier is +incorrect you don't want this condition + + align:start position:0% +incorrect you don't want this condition + + + align:start position:0% +incorrect you don't want this condition +you want to have your plasma very close + + align:start position:0% +you want to have your plasma very close + + + align:start position:0% +you want to have your plasma very close +to your source so I my words are wrong + + align:start position:0% +to your source so I my words are wrong + + + align:start position:0% +to your source so I my words are wrong +but the algebra is right + + align:start position:0% + + + + align:start position:0% + +yeah oh I see yes yes I I take your + + align:start position:0% +yeah oh I see yes yes I I take your + + + align:start position:0% +yeah oh I see yes yes I I take your +point yeah if if you're plasma is + + align:start position:0% +point yeah if if you're plasma is + + + align:start position:0% +point yeah if if you're plasma is +spherical a lot of the time people are + + align:start position:0% +spherical a lot of the time people are + + + align:start position:0% +spherical a lot of the time people are +Imaging plasmas which are quite quite + + align:start position:0% +Imaging plasmas which are quite quite + + + align:start position:0% +Imaging plasmas which are quite quite +big so but yeah you're + + align:start position:0% +big so but yeah you're + + + align:start position:0% +big so but yeah you're +right okay other question + + align:start position:0% + + + + align:start position:0% + +yes oh radians everything's in + + align:start position:0% +yes oh radians everything's in + + + align:start position:0% +yes oh radians everything's in +radians yes much less than one radiant + + align:start position:0% +radians yes much less than one radiant + + + align:start position:0% +radians yes much less than one radiant +it's in radians because we're using this + + align:start position:0% +it's in radians because we're using this + + + align:start position:0% +it's in radians because we're using this +approximation right so if we're using + + align:start position:0% +approximation right so if we're using + + + align:start position:0% +approximation right so if we're using +this approximation Alpha has to be in + + align:start position:0% +this approximation Alpha has to be in + + + align:start position:0% +this approximation Alpha has to be in +radiant that be + + align:start position:0% +radiant that be + + + align:start position:0% +radiant that be +true nothing special about no no no no + + align:start position:0% +true nothing special about no no no no + + + align:start position:0% +true nothing special about no no no no +I'm no there's nothing special about one + + align:start position:0% +I'm no there's nothing special about one + + + align:start position:0% +I'm no there's nothing special about one +Radia it just has to be we want it to be + + align:start position:0% +Radia it just has to be we want it to be + + + align:start position:0% +Radia it just has to be we want it to be +as small as possible one is a number + + align:start position:0% +as small as possible one is a number + + + align:start position:0% +as small as possible one is a number +that it could be smaller than that but I + + align:start position:0% +that it could be smaller than that but I + + + align:start position:0% +that it could be smaller than that but I +guess I could have rised in 10 plus six + + align:start position:0% +guess I could have rised in 10 plus six + + + align:start position:0% +guess I could have rised in 10 plus six +right but yeah yeah sure sure sure I + + align:start position:0% +right but yeah yeah sure sure sure I + + + align:start position:0% +right but yeah yeah sure sure sure I +mean in particular you know we we said + + align:start position:0% +mean in particular you know we we said + + + align:start position:0% +mean in particular you know we we said +that we can get L over a less than one + + align:start position:0% +that we can get L over a less than one + + + align:start position:0% +that we can get L over a less than one +so if we want to get mu much less than + + align:start position:0% +so if we want to get mu much less than + + + align:start position:0% +so if we want to get mu much less than +one that means that Alpha has to be much + + align:start position:0% +one that means that Alpha has to be much + + + align:start position:0% +one that means that Alpha has to be much +less than one from that point of view so + + align:start position:0% +less than one from that point of view so + + + align:start position:0% +less than one from that point of view so +if if you know yeah I think this is a + + align:start position:0% +if if you know yeah I think this is a + + + align:start position:0% +if if you know yeah I think this is a +reasonable that but yeah okay + + align:start position:0% +reasonable that but yeah okay + + + align:start position:0% +reasonable that but yeah okay +any questions + + align:start position:0% + + + + align:start position:0% + +online okay let's have a look at what + + align:start position:0% +online okay let's have a look at what + + + align:start position:0% +online okay let's have a look at what +the actual deflection what this Alpha is + + align:start position:0% +the actual deflection what this Alpha is + + + align:start position:0% +the actual deflection what this Alpha is +here um because that's what you need to + + align:start position:0% +here um because that's what you need to + + + align:start position:0% +here um because that's what you need to +know in order to work out this quantity + + align:start position:0% +know in order to work out this quantity + + + align:start position:0% +know in order to work out this quantity +which is D and work out all the rest of + + align:start position:0% +which is D and work out all the rest of + + + align:start position:0% +which is D and work out all the rest of +the stuff so which Bo should I + + align:start position:0% + + + + align:start position:0% + +use + + align:start position:0% + + + + align:start position:0% + +okay so Alpha for electric and magnetic + + align:start position:0% +okay so Alpha for electric and magnetic + + + align:start position:0% +okay so Alpha for electric and magnetic +Fields + + align:start position:0% +Fields + + + align:start position:0% +Fields +together is simply the integral of that + + align:start position:0% +together is simply the integral of that + + + align:start position:0% +together is simply the integral of that +Force which is e plus v cross + + align:start position:0% +Force which is e plus v cross + + + align:start position:0% +Force which is e plus v cross +B along the path which remember we're + + align:start position:0% +B along the path which remember we're + + + align:start position:0% +B along the path which remember we're +approximating as the + + align:start position:0% + + + + align:start position:0% + +Z like that and the deflection angle is + + align:start position:0% +Z like that and the deflection angle is + + + align:start position:0% +Z like that and the deflection angle is +to do is the charge of course because + + align:start position:0% +to do is the charge of course because + + + align:start position:0% +to do is the charge of course because +that's what goes into the force um but + + align:start position:0% +that's what goes into the force um but + + + align:start position:0% +that's what goes into the force um but +there's also a factor of two and W out + + align:start position:0% +there's also a factor of two and W out + + + align:start position:0% +there's also a factor of two and W out +the front here is + + align:start position:0% +the front here is + + + align:start position:0% +the front here is +W is again the kinetic energy of our + + align:start position:0% +W is again the kinetic energy of our + + + align:start position:0% +W is again the kinetic energy of our +proton M proton V proton + + align:start position:0% +proton M proton V proton + + + align:start position:0% +proton M proton V proton +squ + + align:start position:0% +squ + + + align:start position:0% +squ +there you can work this out if you want + + align:start position:0% +there you can work this out if you want + + + align:start position:0% +there you can work this out if you want +to I haven't proven this exactly so what + + align:start position:0% +to I haven't proven this exactly so what + + + align:start position:0% +to I haven't proven this exactly so what +we notice is interestingly we got a w + + align:start position:0% +we notice is interestingly we got a w + + + align:start position:0% +we notice is interestingly we got a w +that depends on V and here we've got V + + align:start position:0% +that depends on V and here we've got V + + + align:start position:0% +that depends on V and here we've got V +inside this and so we can separately + + align:start position:0% +inside this and so we can separately + + + align:start position:0% +inside this and so we can separately +write out that there's going to be a + + align:start position:0% +write out that there's going to be a + + + align:start position:0% +write out that there's going to be a +deflection due to the electric field + + align:start position:0% +deflection due to the electric field + + + align:start position:0% +deflection due to the electric field +which is e over 2 W integral electric + + align:start position:0% +which is e over 2 W integral electric + + + align:start position:0% +which is e over 2 W integral electric +field d + + align:start position:0% +field d + + + align:start position:0% +field d +z that's pretty obvious I've just taken + + align:start position:0% +z that's pretty obvious I've just taken + + + align:start position:0% +z that's pretty obvious I've just taken +the first there and we have a deflection + + align:start position:0% +the first there and we have a deflection + + + align:start position:0% +the first there and we have a deflection +due to the magnetic + + align:start position:0% +due to the magnetic + + + align:start position:0% +due to the magnetic +field Alpha b equals e over square root + + align:start position:0% +field Alpha b equals e over square root + + + align:start position:0% +field Alpha b equals e over square root +to m + + align:start position:0% +to m + + + align:start position:0% +to m +w taking this velocity and we're + + align:start position:0% +w taking this velocity and we're + + + align:start position:0% +w taking this velocity and we're +combining it with the velocity squ over + + align:start position:0% +combining it with the velocity squ over + + + align:start position:0% +combining it with the velocity squ over +there integral of DL + + align:start position:0% +there integral of DL + + + align:start position:0% +there integral of DL +Frost with B whereas of course this DL + + align:start position:0% +Frost with B whereas of course this DL + + + align:start position:0% +Frost with B whereas of course this DL +is really DZ because of our perial + + align:start position:0% + + + + align:start position:0% + +approximation so we're going to have a + + align:start position:0% +approximation so we're going to have a + + + align:start position:0% +approximation so we're going to have a +deflection angle that depends on the + + align:start position:0% +deflection angle that depends on the + + + align:start position:0% +deflection angle that depends on the +cross product of the path and the + + align:start position:0% +cross product of the path and the + + + align:start position:0% +cross product of the path and the +magnetic + + align:start position:0% +magnetic + + + align:start position:0% +magnetic +field what's interesting about these two + + align:start position:0% +field what's interesting about these two + + + align:start position:0% +field what's interesting about these two +is they have different + + align:start position:0% + + + + align:start position:0% + +scalings one has a scaling with the + + align:start position:0% +scalings one has a scaling with the + + + align:start position:0% +scalings one has a scaling with the +particle energy one has a scaling with + + align:start position:0% +particle energy one has a scaling with + + + align:start position:0% +particle energy one has a scaling with +the square root of the particle energy + + align:start position:0% +the square root of the particle energy + + + align:start position:0% +the square root of the particle energy +so this suggests to us straight away how + + align:start position:0% +so this suggests to us straight away how + + + align:start position:0% +so this suggests to us straight away how +to distinguish between e and + + align:start position:0% + + + + align:start position:0% + +b or I call them Alpha + + align:start position:0% +b or I call them Alpha + + + align:start position:0% +b or I call them Alpha +e and Alpha B so the deflections due to + + align:start position:0% +e and Alpha B so the deflections due to + + + align:start position:0% +e and Alpha B so the deflections due to +electric and magnetic + + align:start position:0% +electric and magnetic + + + align:start position:0% +electric and magnetic +fields and we distinguish between them + + align:start position:0% +fields and we distinguish between them + + + align:start position:0% +fields and we distinguish between them +by using two or + + align:start position:0% +by using two or + + + align:start position:0% +by using two or +more proton + + align:start position:0% + + + + align:start position:0% + +energies if we have a source that + + align:start position:0% +energies if we have a source that + + + align:start position:0% +energies if we have a source that +produces one me protons and 10 me + + align:start position:0% +produces one me protons and 10 me + + + align:start position:0% +produces one me protons and 10 me +protons they will go through the same + + align:start position:0% +protons they will go through the same + + + align:start position:0% +protons they will go through the same +plasma but the one Meb protons will be + + align:start position:0% +plasma but the one Meb protons will be + + + align:start position:0% +plasma but the one Meb protons will be +much more sensitive to oh I've got to + + align:start position:0% +much more sensitive to oh I've got to + + + align:start position:0% +much more sensitive to oh I've got to +get this right now lower energy of this + + align:start position:0% +get this right now lower energy of this + + + align:start position:0% +get this right now lower energy of this +is a bigger number to the electric field + + align:start position:0% +is a bigger number to the electric field + + + align:start position:0% +is a bigger number to the electric field +than the 10 MB protons and so we can use + + align:start position:0% +than the 10 MB protons and so we can use + + + align:start position:0% +than the 10 MB protons and so we can use +a differential measurement effectively + + align:start position:0% +a differential measurement effectively + + + align:start position:0% +a differential measurement effectively +to work out the contribution of alpha e + + align:start position:0% +to work out the contribution of alpha e + + + align:start position:0% +to work out the contribution of alpha e +and Alpha B there'll be two simultaneous + + align:start position:0% +and Alpha B there'll be two simultaneous + + + align:start position:0% +and Alpha B there'll be two simultaneous +equations and we'll have uh two things + + align:start position:0% +equations and we'll have uh two things + + + align:start position:0% +equations and we'll have uh two things +we want to solve for so we'll be able to + + align:start position:0% +we want to solve for so we'll be able to + + + align:start position:0% +we want to solve for so we'll be able to +get it out so this looks an awful lot + + align:start position:0% +get it out so this looks an awful lot + + + align:start position:0% +get it out so this looks an awful lot +like when we talked about two color + + align:start position:0% +like when we talked about two color + + + align:start position:0% +like when we talked about two color +interferometry to determine the + + align:start position:0% +interferometry to determine the + + + align:start position:0% +interferometry to determine the +difference between vibrations or + + align:start position:0% +difference between vibrations or + + + align:start position:0% +difference between vibrations or +neutrals in our + + align:start position:0% + + + + align:start position:0% + +plasma and people do this a lot because + + align:start position:0% +plasma and people do this a lot because + + + align:start position:0% +plasma and people do this a lot because +if you're doing experiment you don't a + + align:start position:0% +if you're doing experiment you don't a + + + align:start position:0% +if you're doing experiment you don't a +priority know whether the electric + + align:start position:0% +priority know whether the electric + + + align:start position:0% +priority know whether the electric +fields are small compared to the + + align:start position:0% +fields are small compared to the + + + align:start position:0% +fields are small compared to the +magnetic fields most people want to use + + align:start position:0% +magnetic fields most people want to use + + + align:start position:0% +magnetic fields most people want to use +this technique to measure magnetic + + align:start position:0% +this technique to measure magnetic + + + align:start position:0% +this technique to measure magnetic +fields um and usually it's the case + + align:start position:0% +fields um and usually it's the case + + + align:start position:0% +fields um and usually it's the case +magnetic fields do dominate but you + + align:start position:0% +magnetic fields do dominate but you + + + align:start position:0% +magnetic fields do dominate but you +still need to check and you can do it + + align:start position:0% +still need to check and you can do it + + + align:start position:0% +still need to check and you can do it +with these two different + + align:start position:0% + + + + align:start position:0% + +energies so we've been talking a lot + + align:start position:0% +energies so we've been talking a lot + + + align:start position:0% +energies so we've been talking a lot +about Alpha here but there's a rather + + align:start position:0% +about Alpha here but there's a rather + + + align:start position:0% +about Alpha here but there's a rather +neat + + align:start position:0% +neat + + + align:start position:0% +neat +formulation which says well instead of + + align:start position:0% +formulation which says well instead of + + + align:start position:0% +formulation which says well instead of +talking about this Vector Alpha and that + + align:start position:0% +talking about this Vector Alpha and that + + + align:start position:0% +talking about this Vector Alpha and that +deflection angle Alpha depends on where + + align:start position:0% +deflection angle Alpha depends on where + + + align:start position:0% +deflection angle Alpha depends on where +you are in the plasma so it depends on + + align:start position:0% +you are in the plasma so it depends on + + + align:start position:0% +you are in the plasma so it depends on +your position X not within the plasma if + + align:start position:0% +your position X not within the plasma if + + + align:start position:0% +your position X not within the plasma if +this is a vector then we can just write + + align:start position:0% +this is a vector then we can just write + + + align:start position:0% +this is a vector then we can just write +it as the gradient of some scalar that's + + align:start position:0% +it as the gradient of some scalar that's + + + align:start position:0% +it as the gradient of some scalar that's +just generally true so we can say what + + align:start position:0% +just generally true so we can say what + + + align:start position:0% +just generally true so we can say what +if there is some scalar by of X zero and + + align:start position:0% +if there is some scalar by of X zero and + + + align:start position:0% +if there is some scalar by of X zero and +Alpha is just its gradient and the + + align:start position:0% +Alpha is just its gradient and the + + + align:start position:0% +Alpha is just its gradient and the +reason you want to do this is you can + + align:start position:0% +reason you want to do this is you can + + + align:start position:0% +reason you want to do this is you can +now write dial expression for fi which + + align:start position:0% +now write dial expression for fi which + + + align:start position:0% +now write dial expression for fi which +works for shog graphy as well as proton + + align:start position:0% +works for shog graphy as well as proton + + + align:start position:0% +works for shog graphy as well as proton +Imaging and then all of the mathematics + + align:start position:0% +Imaging and then all of the mathematics + + + align:start position:0% +Imaging and then all of the mathematics +that you've done previously you just do + + align:start position:0% +that you've done previously you just do + + + align:start position:0% +that you've done previously you just do +it in terms of + + align:start position:0% +it in terms of + + + align:start position:0% +it in terms of +and it doesn't it's sort of agnostically + + align:start position:0% +and it doesn't it's sort of agnostically + + + align:start position:0% +and it doesn't it's sort of agnostically +exact technique that we use so for + + align:start position:0% + + + + align:start position:0% + +geography you find that your deflection + + align:start position:0% +geography you find that your deflection + + + align:start position:0% +geography you find that your deflection +potential is equal to minus the integral + + align:start position:0% +potential is equal to minus the integral + + + align:start position:0% +potential is equal to minus the integral +of the + + align:start position:0% +of the + + + align:start position:0% +of the +logarithm of the refractive index n and + + align:start position:0% +logarithm of the refractive index n and + + + align:start position:0% +logarithm of the refractive index n and +I'll explicitly write this out in terms + + align:start position:0% +I'll explicitly write this out in terms + + + align:start position:0% +I'll explicitly write this out in terms +of the position within the plasma + + align:start position:0% + + + + align:start position:0% + +the z0 so the integral along through the + + align:start position:0% +the z0 so the integral along through the + + + align:start position:0% +the z0 so the integral along through the +plasma in The Zed Direction and this + + align:start position:0% +plasma in The Zed Direction and this + + + align:start position:0% +plasma in The Zed Direction and this +logarithm here or this n here is of + + align:start position:0% +logarithm here or this n here is of + + + align:start position:0% +logarithm here or this n here is of +course the one where we have n^2 equal 1 + + align:start position:0% +course the one where we have n^2 equal 1 + + + align:start position:0% +course the one where we have n^2 equal 1 +minus NE over n c that we saw in all our + + align:start position:0% +minus NE over n c that we saw in all our + + + align:start position:0% +minus NE over n c that we saw in all our +refractive index things though of course + + align:start position:0% +refractive index things though of course + + + align:start position:0% +refractive index things though of course +it could be whatever o mode X mode but + + align:start position:0% +it could be whatever o mode X mode but + + + align:start position:0% +it could be whatever o mode X mode but +people don't do proton radiography in so + + align:start position:0% +people don't do proton radiography in so + + + align:start position:0% +people don't do proton radiography in so +um the plasmas we're working with + + align:start position:0% +um the plasmas we're working with + + + align:start position:0% +um the plasmas we're working with +they're mostly unmagnified this is fine + + align:start position:0% +they're mostly unmagnified this is fine + + + align:start position:0% +they're mostly unmagnified this is fine +for the E + + align:start position:0% + + + + align:start position:0% + +Fields this potential + + align:start position:0% + + + + align:start position:0% + +here is just equal to Q over two w did I + + align:start position:0% +here is just equal to Q over two w did I + + + align:start position:0% +here is just equal to Q over two w did I +use Q over there no I switched to e so + + align:start position:0% +use Q over there no I switched to e so + + + align:start position:0% +use Q over there no I switched to e so +I'll put it back + + align:start position:0% + + + + align:start position:0% + +e integral of the real electros datic + + align:start position:0% +e integral of the real electros datic + + + align:start position:0% +e integral of the real electros datic +potential lowercase f + + align:start position:0% +potential lowercase f + + + align:start position:0% +potential lowercase f +x0 y0 z0 D z0 so they are related they + + align:start position:0% +x0 y0 z0 D z0 so they are related they + + + align:start position:0% +x0 y0 z0 D z0 so they are related they +don't have to be but they are in this + + align:start position:0% +don't have to be but they are in this + + + align:start position:0% +don't have to be but they are in this +case the related the deflection + + align:start position:0% +case the related the deflection + + + align:start position:0% +case the related the deflection +potential is related to electrostatic + + align:start position:0% +potential is related to electrostatic + + + align:start position:0% +potential is related to electrostatic +potential and then the final one is the + + align:start position:0% +potential and then the final one is the + + + align:start position:0% +potential and then the final one is the +magnetic + + align:start position:0% + + + + align:start position:0% + +fields Capital 5 + + align:start position:0% +fields Capital 5 + + + align:start position:0% +fields Capital 5 +x0 is equal to e upon square root of 2 m + + align:start position:0% +x0 is equal to e upon square root of 2 m + + + align:start position:0% +x0 is equal to e upon square root of 2 m +w integral of + + align:start position:0% +w integral of + + + align:start position:0% +w integral of +a do + + align:start position:0% +a do + + + align:start position:0% +a do +dz0 and this + + align:start position:0% + + + + align:start position:0% + +a is the magnetic Vector potential so B + + align:start position:0% +a is the magnetic Vector potential so B + + + align:start position:0% +a is the magnetic Vector potential so B +is equal to the curl of + + align:start position:0% +is equal to the curl of + + + align:start position:0% +is equal to the curl of +a but the idea is that we will seek + + align:start position:0% +a but the idea is that we will seek + + + align:start position:0% +a but the idea is that we will seek +techniques which will take our intensity + + align:start position:0% +techniques which will take our intensity + + + align:start position:0% +techniques which will take our intensity +Vari + + align:start position:0% +Vari + + + align:start position:0% +Vari +I on our detector and we will use them + + align:start position:0% +I on our detector and we will use them + + + align:start position:0% +I on our detector and we will use them +to infer some sort of deflection + + align:start position:0% +to infer some sort of deflection + + + align:start position:0% +to infer some sort of deflection +potential and then the neat thing is it + + align:start position:0% +potential and then the neat thing is it + + + align:start position:0% +potential and then the neat thing is it +doesn't matter whether we're looking at + + align:start position:0% +doesn't matter whether we're looking at + + + align:start position:0% +doesn't matter whether we're looking at +electric fields or magnetic fields + + align:start position:0% +electric fields or magnetic fields + + + align:start position:0% +electric fields or magnetic fields +orography that's sort of like a detail + + align:start position:0% +orography that's sort of like a detail + + + align:start position:0% +orography that's sort of like a detail +that the end user has to use but the + + align:start position:0% +that the end user has to use but the + + + align:start position:0% +that the end user has to use but the +algorithms are all the same so this is + + align:start position:0% +algorithms are all the same so this is + + + align:start position:0% +algorithms are all the same so this is +very powerful we can share techniques + + align:start position:0% +very powerful we can share techniques + + + align:start position:0% +very powerful we can share techniques +between very disperate looking + + align:start position:0% +between very disperate looking + + + align:start position:0% +between very disperate looking +Diagnostics um Professor yes does the B + + align:start position:0% +Diagnostics um Professor yes does the B + + + align:start position:0% +Diagnostics um Professor yes does the B +is a where b equals uh R uh the like the + + align:start position:0% +is a where b equals uh R uh the like the + + + align:start position:0% +is a where b equals uh R uh the like the +Cur of a is that from um the Maxwell's + + align:start position:0% +Cur of a is that from um the Maxwell's + + + align:start position:0% +Cur of a is that from um the Maxwell's +law B like the Divergence is zero is + + align:start position:0% +law B like the Divergence is zero is + + + align:start position:0% +law B like the Divergence is zero is +that where that comes + + align:start position:0% +that where that comes + + + align:start position:0% +that where that comes +from oh gosh + + align:start position:0% +from oh gosh + + + align:start position:0% +from oh gosh +yes um Can Divergence fre Fields be + + align:start position:0% +yes um Can Divergence fre Fields be + + + align:start position:0% +yes um Can Divergence fre Fields be +written as the Cur of another Vector I + + align:start position:0% +written as the Cur of another Vector I + + + align:start position:0% +written as the Cur of another Vector I +think so yeah okay then where does um + + align:start position:0% +think so yeah okay then where does um + + + align:start position:0% +think so yeah okay then where does um +the potential come is it just like a + + align:start position:0% +the potential come is it just like a + + + align:start position:0% +the potential come is it just like a +regular electric potential or yeah this + + align:start position:0% +regular electric potential or yeah this + + + align:start position:0% +regular electric potential or yeah this +is the electric potential right this is + + align:start position:0% +is the electric potential right this is + + + align:start position:0% +is the electric potential right this is +the potential that's defined by Bon's + + align:start position:0% +the potential that's defined by Bon's + + + align:start position:0% +the potential that's defined by Bon's +equation + + align:start position:0% +equation + + + align:start position:0% +equation +I see okay yeah just wanted to check + + align:start position:0% +I see okay yeah just wanted to check + + + align:start position:0% +I see okay yeah just wanted to check +thank you + + align:start position:0% + + + + align:start position:0% + +yeah okay any questions on that the next + + align:start position:0% +yeah okay any questions on that the next + + + align:start position:0% +yeah okay any questions on that the next +thing I'm going to cover is how do we + + align:start position:0% +thing I'm going to cover is how do we + + + align:start position:0% +thing I'm going to cover is how do we +make these beams of protons we're going + + align:start position:0% +make these beams of protons we're going + + + align:start position:0% +make these beams of protons we're going +to switch gears a little bit so if you + + align:start position:0% +to switch gears a little bit so if you + + + align:start position:0% +to switch gears a little bit so if you +have any questions on uh what's happened + + align:start position:0% +have any questions on uh what's happened + + + align:start position:0% +have any questions on uh what's happened +so far this is a good time + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +yeah we these are these are + + align:start position:0% +yeah we these are these are + + + align:start position:0% +yeah we these are these are +contradictory yes yeah so so the prac + + align:start position:0% +contradictory yes yeah so so the prac + + + align:start position:0% +contradictory yes yeah so so the prac +approximation also makes it very hard to + + align:start position:0% +approximation also makes it very hard to + + + align:start position:0% +approximation also makes it very hard to +have your object very close that if you + + align:start position:0% +have your object very close that if you + + + align:start position:0% +have your object very close that if you +were able to do that you would reduce + + align:start position:0% +were able to do that you would reduce + + + align:start position:0% +were able to do that you would reduce +the contrast parameter but you would + + align:start position:0% +the contrast parameter but you would + + + align:start position:0% +the contrast parameter but you would +also break all of the mathematics we've + + align:start position:0% +also break all of the mathematics we've + + + align:start position:0% +also break all of the mathematics we've +done which is used the parial + + align:start position:0% +done which is used the parial + + + align:start position:0% +done which is used the parial +approximation so far so in practice your + + align:start position:0% +approximation so far so in practice your + + + align:start position:0% +approximation so far so in practice your +best bet is to reduce Alpha instead and + + align:start position:0% +best bet is to reduce Alpha instead and + + + align:start position:0% +best bet is to reduce Alpha instead and +you reduce Alpha by making your protons + + align:start position:0% +you reduce Alpha by making your protons + + + align:start position:0% +you reduce Alpha by making your protons +as fast as possible because the faster + + align:start position:0% +as fast as possible because the faster + + + align:start position:0% +as fast as possible because the faster +your protons are the higher their energy + + align:start position:0% +your protons are the higher their energy + + + align:start position:0% +your protons are the higher their energy +they lower their deflections so this is + + align:start position:0% +they lower their deflections so this is + + + align:start position:0% +they lower their deflections so this is +what motivates us using me or higher + + align:start position:0% +what motivates us using me or higher + + + align:start position:0% +what motivates us using me or higher +beams of pro + + align:start position:0% + + + + align:start position:0% + +yeah the particle is being deflected a + + align:start position:0% +yeah the particle is being deflected a + + + align:start position:0% +yeah the particle is being deflected a +little bit approximation mostly same + + align:start position:0% +little bit approximation mostly same + + + align:start position:0% +little bit approximation mostly same +direction it's certainly not being + + align:start position:0% +direction it's certainly not being + + + align:start position:0% +direction it's certainly not being +decelerated velocity is constant right + + align:start position:0% +decelerated velocity is constant right + + + align:start position:0% +decelerated velocity is constant right +so the site the the size of its velocity + + align:start position:0% +so the site the the size of its velocity + + + align:start position:0% +so the site the the size of its velocity +its speed doesn't change as it goes + + align:start position:0% +its speed doesn't change as it goes + + + align:start position:0% +its speed doesn't change as it goes +through the plasma that's also + + align:start position:0% +through the plasma that's also + + + align:start position:0% +through the plasma that's also +consistent with our test particle + + align:start position:0% +consistent with our test particle + + + align:start position:0% +consistent with our test particle +picture where the test particle is + + align:start position:0% +picture where the test particle is + + + align:start position:0% +picture where the test particle is +experiencing the fields but it's not + + align:start position:0% +experiencing the fields but it's not + + + align:start position:0% +experiencing the fields but it's not +sort of like being slowed down yeah is + + align:start position:0% +sort of like being slowed down yeah is + + + align:start position:0% +sort of like being slowed down yeah is +that + + align:start position:0% + + + + align:start position:0% + +like yeah the particles are really + + align:start position:0% +like yeah the particles are really + + + align:start position:0% +like yeah the particles are really +really fast they don't they don't + + align:start position:0% +really fast they don't they don't + + + align:start position:0% +really fast they don't they don't +scatter at all they're way faster than + + align:start position:0% +scatter at all they're way faster than + + + align:start position:0% +scatter at all they're way faster than +everything else yeah yeah so this is a + + align:start position:0% +everything else yeah yeah so this is a + + + align:start position:0% +everything else yeah yeah so this is a +completely reasonable approximation yeah + + align:start position:0% +completely reasonable approximation yeah + + + align:start position:0% +completely reasonable approximation yeah +yeah yeah it's basically this you can + + align:start position:0% +yeah yeah it's basically this you can + + + align:start position:0% +yeah yeah it's basically this you can +treat the plasma as this like static + + align:start position:0% +treat the plasma as this like static + + + align:start position:0% +treat the plasma as this like static +unmoving thing on the time scale of + + align:start position:0% +unmoving thing on the time scale of + + + align:start position:0% +unmoving thing on the time scale of +these protons going through and the + + align:start position:0% +these protons going through and the + + + align:start position:0% +these protons going through and the +protons barely see it apart from they + + align:start position:0% +protons barely see it apart from they + + + align:start position:0% +protons barely see it apart from they +get deflected a tiny amount and it's + + align:start position:0% +get deflected a tiny amount and it's + + + align:start position:0% +get deflected a tiny amount and it's +only because we put our detector so far + + align:start position:0% +only because we put our detector so far + + + align:start position:0% +only because we put our detector so far +way that those tiny deflections show up + + align:start position:0% +way that those tiny deflections show up + + + align:start position:0% +way that those tiny deflections show up +as significant changes + + align:start position:0% +as significant changes + + + align:start position:0% +as significant changes +fluence okay any other questions + + align:start position:0% +fluence okay any other questions + + + align:start position:0% +fluence okay any other questions +anything + + align:start position:0% + + + + align:start position:0% + +online + + align:start position:0% + + + + align:start position:0% + +yeah yeah yeah it's the Su the the + + align:start position:0% +yeah yeah yeah it's the Su the the + + + align:start position:0% +yeah yeah yeah it's the Su the the +reflection potentials add linearly which + + align:start position:0% +reflection potentials add linearly which + + + align:start position:0% +reflection potentials add linearly which +is neat as well yeah and then when you + + align:start position:0% +is neat as well yeah and then when you + + + align:start position:0% +is neat as well yeah and then when you +use two different + + align:start position:0% +use two different + + + align:start position:0% +use two different +energies you can solve separately for + + align:start position:0% +energies you can solve separately for + + + align:start position:0% +energies you can solve separately for +the two deflection potentials and then + + align:start position:0% +the two deflection potentials and then + + + align:start position:0% +the two deflection potentials and then +see how big they + + align:start position:0% +see how big they + + + align:start position:0% +see how big they +are okay let's talk about how to make a + + align:start position:0% +are okay let's talk about how to make a + + + align:start position:0% +are okay let's talk about how to make a +f of + + align:start position:0% + + + + align:start position:0% + +prot this is actually quite frustrating + + align:start position:0% +prot this is actually quite frustrating + + + align:start position:0% +prot this is actually quite frustrating +when I taught this in 2021 there was no + + align:start position:0% +when I taught this in 2021 there was no + + + align:start position:0% +when I taught this in 2021 there was no +good reference on this and I had to + + align:start position:0% +good reference on this and I had to + + + align:start position:0% +good reference on this and I had to +spend ages looking it up and then Derek + + align:start position:0% +spend ages looking it up and then Derek + + + align:start position:0% +spend ages looking it up and then Derek +schaer put his paper on archive and + + align:start position:0% +schaer put his paper on archive and + + + align:start position:0% +schaer put his paper on archive and +explains it all really straightforwardly + + align:start position:0% +explains it all really straightforwardly + + + align:start position:0% +explains it all really straightforwardly +so if you want to understand it you can + + align:start position:0% +so if you want to understand it you can + + + align:start position:0% +so if you want to understand it you can +just paper but uh yeah this interesting + + align:start position:0% +just paper but uh yeah this interesting + + + align:start position:0% +just paper but uh yeah this interesting +stuff because this technique is + + align:start position:0% +stuff because this technique is + + + align:start position:0% +stuff because this technique is +relatively modern it's only within about + + align:start position:0% +relatively modern it's only within about + + + align:start position:0% +relatively modern it's only within about +the last 20 years that people have + + align:start position:0% +the last 20 years that people have + + + align:start position:0% +the last 20 years that people have +really been using it and a lot of the + + align:start position:0% +really been using it and a lot of the + + + align:start position:0% +really been using it and a lot of the +development of this technique was led by + + align:start position:0% +development of this technique was led by + + + align:start position:0% +development of this technique was led by +the H group here at MIT so a lot of the + + align:start position:0% +the H group here at MIT so a lot of the + + + align:start position:0% +the H group here at MIT so a lot of the +things I'm going to tell you about are + + align:start position:0% +things I'm going to tell you about are + + + align:start position:0% +things I'm going to tell you about are +MIT diagn + + align:start position:0% + + + + align:start position:0% + +development + + align:start position:0% +development + + + align:start position:0% +development +so we need to have a + + align:start position:0% + + + + align:start position:0% + +source and for each Source there is a + + align:start position:0% + + + + align:start position:0% + +detector but the First Source that I'm + + align:start position:0% +detector but the First Source that I'm + + + align:start position:0% +detector but the First Source that I'm +going to talk about is a technique + + align:start position:0% +going to talk about is a technique + + + align:start position:0% +going to talk about is a technique +called P + + align:start position:0% +called P + + + align:start position:0% +called P +NS + + align:start position:0% +NS + + + align:start position:0% +NS +a this stands + + align:start position:0% +a this stands + + + align:start position:0% +a this stands +for + + align:start position:0% +for + + + align:start position:0% +for +Target and doesn't really matter uh + + align:start position:0% +Target and doesn't really matter uh + + + align:start position:0% +Target and doesn't really matter uh +Target + + align:start position:0% + + + + align:start position:0% + +normal + + align:start position:0% + + + + align:start position:0% + +be + + align:start position:0% + + + + align:start position:0% + +acceleration you can't quite sing it to + + align:start position:0% +acceleration you can't quite sing it to + + + align:start position:0% +acceleration you can't quite sing it to +the tune of teenage mutants nja Turtle + + align:start position:0% +the tune of teenage mutants nja Turtle + + + align:start position:0% +the tune of teenage mutants nja Turtle +sadly but it's getting pretty close so + + align:start position:0% +sadly but it's getting pretty close so + + + align:start position:0% +sadly but it's getting pretty close so +the idea of tnsa and I will never say + + align:start position:0% +the idea of tnsa and I will never say + + + align:start position:0% +the idea of tnsa and I will never say +Target normal sheet acceleration again + + align:start position:0% +Target normal sheet acceleration again + + + align:start position:0% +Target normal sheet acceleration again +uh is you have a metal + + align:start position:0% +uh is you have a metal + + + align:start position:0% +uh is you have a metal +fo + + align:start position:0% + + + + align:start position:0% + +and it's thin you know tens of microns + + align:start position:0% +and it's thin you know tens of microns + + + align:start position:0% +and it's thin you know tens of microns +thin and any metal that you have is + + align:start position:0% +thin and any metal that you have is + + + align:start position:0% +thin and any metal that you have is +going to have absorbed on its + + align:start position:0% +going to have absorbed on its + + + align:start position:0% +going to have absorbed on its +surface lots of hydrocarbons which means + + align:start position:0% +surface lots of hydrocarbons which means + + + align:start position:0% +surface lots of hydrocarbons which means +lots of little + + align:start position:0% +lots of little + + + align:start position:0% +lots of little +protons so again we're not accelerating + + align:start position:0% +protons so again we're not accelerating + + + align:start position:0% +protons so again we're not accelerating +copper or something like this here we're + + align:start position:0% +copper or something like this here we're + + + align:start position:0% +copper or something like this here we're +still accelerating protons it just turns + + align:start position:0% +still accelerating protons it just turns + + + align:start position:0% +still accelerating protons it just turns +out there's lots of little protons + + align:start position:0% +out there's lots of little protons + + + align:start position:0% +out there's lots of little protons +absorbed in the structure on the front + + align:start position:0% +absorbed in the structure on the front + + + align:start position:0% +absorbed in the structure on the front +here and we take our laser + + align:start position:0% +here and we take our laser + + + align:start position:0% +here and we take our laser +beam and we focus it + + align:start position:0% + + + + align:start position:0% + +down and hit the back side of this + + align:start position:0% +down and hit the back side of this + + + align:start position:0% +down and hit the back side of this +Target and our laser beam is ultra short + + align:start position:0% + + + + align:start position:0% + +pulse so this tends to be something like + + align:start position:0% +pulse so this tends to be something like + + + align:start position:0% +pulse so this tends to be something like +a 50 Jewel laser in one PC 10 to minus + + align:start position:0% +a 50 Jewel laser in one PC 10 to minus + + + align:start position:0% +a 50 Jewel laser in one PC 10 to minus +12 seconds so this is over 100 ter + + align:start position:0% +12 seconds so this is over 100 ter + + + align:start position:0% +12 seconds so this is over 100 ter +terawatts of laser power or if if you + + align:start position:0% +terawatts of laser power or if if you + + + align:start position:0% +terawatts of laser power or if if you +got a really short pulse you can do one + + align:start position:0% +got a really short pulse you can do one + + + align:start position:0% +got a really short pulse you can do one +Jewel in 50 F to seconds a fc is 10 to + + align:start position:0% +Jewel in 50 F to seconds a fc is 10 to + + + align:start position:0% +Jewel in 50 F to seconds a fc is 10 to +the minus 15 seconds so these are + + align:start position:0% +the minus 15 seconds so these are + + + align:start position:0% +the minus 15 seconds so these are +seriously short laser pulses and this is + + align:start position:0% +seriously short laser pulses and this is + + + align:start position:0% +seriously short laser pulses and this is +a seriously intense focal spot here down + + align:start position:0% +a seriously intense focal spot here down + + + align:start position:0% +a seriously intense focal spot here down +to + + align:start position:0% +to + + + align:start position:0% +to +about 10 microns we can focus the laser + + align:start position:0% +about 10 microns we can focus the laser + + + align:start position:0% +about 10 microns we can focus the laser +down to so that's a lot of electrical + + align:start position:0% +down to so that's a lot of electrical + + + align:start position:0% +down to so that's a lot of electrical +energy being focused into a very small + + align:start position:0% +energy being focused into a very small + + + align:start position:0% +energy being focused into a very small +spot uh on a very short time scale and + + align:start position:0% +spot uh on a very short time scale and + + + align:start position:0% +spot uh on a very short time scale and +what that does is it initially + + align:start position:0% +what that does is it initially + + + align:start position:0% +what that does is it initially +electrons off the foil so there is some + + align:start position:0% +electrons off the foil so there is some + + + align:start position:0% +electrons off the foil so there is some +heating there are some strong electric + + align:start position:0% +heating there are some strong electric + + + align:start position:0% +heating there are some strong electric +fields for reasons that we're not going + + align:start position:0% +fields for reasons that we're not going + + + align:start position:0% +fields for reasons that we're not going +to go into very much this drives + + align:start position:0% +to go into very much this drives + + + align:start position:0% +to go into very much this drives +electrons off the foil at high speed and + + align:start position:0% +electrons off the foil at high speed and + + + align:start position:0% +electrons off the foil at high speed and +they form a sort of little Cloud going + + align:start position:0% +they form a sort of little Cloud going + + + align:start position:0% +they form a sort of little Cloud going +outwards because there's been electrons + + align:start position:0% +outwards because there's been electrons + + + align:start position:0% +outwards because there's been electrons +ejected we then have an electric + + align:start position:0% + + + + align:start position:0% + +field and that electric field drags + + align:start position:0% +field and that electric field drags + + + align:start position:0% +field and that electric field drags +these protons off the + + align:start position:0% + + + + align:start position:0% + +surface + + align:start position:0% +surface + + + align:start position:0% +surface +like that and this is how the protons + + align:start position:0% +like that and this is how the protons + + + align:start position:0% +like that and this is how the protons +are accelerating so this technique some + + align:start position:0% +are accelerating so this technique some + + + align:start position:0% +are accelerating so this technique some +good things about it it gives us many + + align:start position:0% +good things about it it gives us many + + + align:start position:0% +good things about it it gives us many +protons it's a very efficient way of + + align:start position:0% +protons it's a very efficient way of + + + align:start position:0% +protons it's a very efficient way of +accelerating the protons here it gives + + align:start position:0% +accelerating the protons here it gives + + + align:start position:0% +accelerating the protons here it gives +us a range of + + align:start position:0% + + + + align:start position:0% + +energies remember we said we'd like + + align:start position:0% +energies remember we said we'd like + + + align:start position:0% +energies remember we said we'd like +several different energies for telling + + align:start position:0% +several different energies for telling + + + align:start position:0% +several different energies for telling +difference in electric and magnetic + + align:start position:0% +difference in electric and magnetic + + + align:start position:0% +difference in electric and magnetic +fields the spot + + align:start position:0% +fields the spot + + + align:start position:0% +fields the spot +size + + align:start position:0% +size + + + align:start position:0% +size +is around about 10 microns so as we said + + align:start position:0% +is around about 10 microns so as we said + + + align:start position:0% +is around about 10 microns so as we said +that's a nice small spot that's + + align:start position:0% +that's a nice small spot that's + + + align:start position:0% +that's a nice small spot that's +something we wanted in order for all our + + align:start position:0% +something we wanted in order for all our + + + align:start position:0% +something we wanted in order for all our +praxial approximation and stuff to work + + align:start position:0% +praxial approximation and stuff to work + + + align:start position:0% +praxial approximation and stuff to work +and it's a + + align:start position:0% +and it's a + + + align:start position:0% +and it's a +beam it's in One Direction and we'll see + + align:start position:0% +beam it's in One Direction and we'll see + + + align:start position:0% +beam it's in One Direction and we'll see +why that's important when we compare the + + align:start position:0% +why that's important when we compare the + + + align:start position:0% +why that's important when we compare the +other + + align:start position:0% + + + + align:start position:0% + +meth the big disadvantage of this + + align:start position:0% +meth the big disadvantage of this + + + align:start position:0% +meth the big disadvantage of this +technique is you + + align:start position:0% +technique is you + + + align:start position:0% +technique is you +need a petat + + align:start position:0% +need a petat + + + align:start position:0% +need a petat +class + + align:start position:0% +class + + + align:start position:0% +class +laser or higher so you need to have one + + align:start position:0% +laser or higher so you need to have one + + + align:start position:0% +laser or higher so you need to have one +of these Ultra short pulse lasers not + + align:start position:0% +of these Ultra short pulse lasers not + + + align:start position:0% +of these Ultra short pulse lasers not +every facility has that these are very + + align:start position:0% +every facility has that these are very + + + align:start position:0% +every facility has that these are very +expensive things to build so it's not + + align:start position:0% +expensive things to build so it's not + + + align:start position:0% +expensive things to build so it's not +like you can just go down to the toop + + align:start position:0% +like you can just go down to the toop + + + align:start position:0% +like you can just go down to the toop +and get this I thought about trying to + + align:start position:0% +and get this I thought about trying to + + + align:start position:0% +and get this I thought about trying to +get one of these for a puffing facility + + align:start position:0% +get one of these for a puffing facility + + + align:start position:0% +get one of these for a puffing facility +and we got a quote about $2 million for + + align:start position:0% +and we got a quote about $2 million for + + + align:start position:0% +and we got a quote about $2 million for +a laser to just do a not very good tnsa + + align:start position:0% +a laser to just do a not very good tnsa + + + align:start position:0% +a laser to just do a not very good tnsa +signal so um is a very + + align:start position:0% + + + + align:start position:0% + +exp but that's your source your + + align:start position:0% + + + + align:start position:0% + +detector is something which is called + + align:start position:0% +detector is something which is called + + + align:start position:0% +detector is something which is called +radio chromic + + align:start position:0% + + + + align:start position:0% + +film another acronym I'm not going to + + align:start position:0% +film another acronym I'm not going to + + + align:start position:0% +film another acronym I'm not going to +repeat we'll call it RCF from now on + + align:start position:0% +repeat we'll call it RCF from now on + + + align:start position:0% +repeat we'll call it RCF from now on +okay now RCF changes color when it's hit + + align:start position:0% +okay now RCF changes color when it's hit + + + align:start position:0% +okay now RCF changes color when it's hit +by protons that's the chromic part of + + align:start position:0% + + + + align:start position:0% + +it and the more protons that hit it the + + align:start position:0% +it and the more protons that hit it the + + + align:start position:0% +it and the more protons that hit it the +more it changes color it sort of starts + + align:start position:0% +more it changes color it sort of starts + + + align:start position:0% +more it changes color it sort of starts +off quite clear and it turns this + + align:start position:0% +off quite clear and it turns this + + + align:start position:0% +off quite clear and it turns this +beautiful like ghostly blue and then + + align:start position:0% +beautiful like ghostly blue and then + + + align:start position:0% +beautiful like ghostly blue and then +goes into a very dark deep blue they're + + align:start position:0% +goes into a very dark deep blue they're + + + align:start position:0% +goes into a very dark deep blue they're +very beautiful the raw proton uh + + align:start position:0% +very beautiful the raw proton uh + + + align:start position:0% +very beautiful the raw proton uh +radiochromic film + + align:start position:0% +radiochromic film + + + align:start position:0% +radiochromic film +images now what you end up doing is you + + align:start position:0% +images now what you end up doing is you + + + align:start position:0% +images now what you end up doing is you +have stacks of this film you have + + align:start position:0% +have stacks of this film you have + + + align:start position:0% +have stacks of this film you have +multiple + + align:start position:0% + + + + align:start position:0% + +sheets so imagine these are squares of + + align:start position:0% +sheets so imagine these are squares of + + + align:start position:0% +sheets so imagine these are squares of +film and I've just made a stack out of + + align:start position:0% +film and I've just made a stack out of + + + align:start position:0% +film and I've just made a stack out of +lots of them like this and the reason + + align:start position:0% +lots of them like this and the reason + + + align:start position:0% +lots of them like this and the reason +you make lots of stacks out of these is + + align:start position:0% +you make lots of stacks out of these is + + + align:start position:0% +you make lots of stacks out of these is +due to a peculiarity of charge particle + + align:start position:0% +due to a peculiarity of charge particle + + + align:start position:0% +due to a peculiarity of charge particle +stopping and this peculiarity is called + + align:start position:0% +stopping and this peculiarity is called + + + align:start position:0% +stopping and this peculiarity is called +the brag Peak which some of you may have + + align:start position:0% +the brag Peak which some of you may have + + + align:start position:0% +the brag Peak which some of you may have +come across + + align:start position:0% +come across + + + align:start position:0% +come across +before the idea of the brag Peak is your + + align:start position:0% +before the idea of the brag Peak is your + + + align:start position:0% +before the idea of the brag Peak is your +charged particles tend to stop in a very + + align:start position:0% +charged particles tend to stop in a very + + + align:start position:0% +charged particles tend to stop in a very +specific place for a material which is + + align:start position:0% +specific place for a material which is + + + align:start position:0% +specific place for a material which is +to do with their energy so for example + + align:start position:0% +to do with their energy so for example + + + align:start position:0% +to do with their energy so for example +uh if this is the stopping location + + align:start position:0% +uh if this is the stopping location + + + align:start position:0% +uh if this is the stopping location +X call this the x coordinate I guess + + align:start position:0% +X call this the x coordinate I guess + + + align:start position:0% +X call this the x coordinate I guess +I've called it Z everywh else but + + align:start position:0% +I've called it Z everywh else but + + + align:start position:0% +I've called it Z everywh else but +whatever um you tend to have a lot of + + align:start position:0% +whatever um you tend to have a lot of + + + align:start position:0% +whatever um you tend to have a lot of +deposition of your particles all at one + + align:start position:0% +deposition of your particles all at one + + + align:start position:0% +deposition of your particles all at one +place and this is energy dependent so + + align:start position:0% +place and this is energy dependent so + + + align:start position:0% +place and this is energy dependent so +this is + + align:start position:0% +this is + + + align:start position:0% +this is +energy dependent + + align:start position:0% + + + + align:start position:0% + +deposition the reason this is peculiar + + align:start position:0% +deposition the reason this is peculiar + + + align:start position:0% +deposition the reason this is peculiar +is you'll remember that for photons + + align:start position:0% +is you'll remember that for photons + + + align:start position:0% +is you'll remember that for photons +we just had this exponential decay + + align:start position:0% +we just had this exponential decay + + + align:start position:0% +we just had this exponential decay +here that was J with the opacity of it + + align:start position:0% +here that was J with the opacity of it + + + align:start position:0% +here that was J with the opacity of it +but that's not what we get for + + align:start position:0% +but that's not what we get for + + + align:start position:0% +but that's not what we get for +particles the fact that all the + + align:start position:0% +particles the fact that all the + + + align:start position:0% +particles the fact that all the +particles are the same energy roughly + + align:start position:0% +particles are the same energy roughly + + + align:start position:0% +particles are the same energy roughly +stop in the same bit of film means that + + align:start position:0% +stop in the same bit of film means that + + + align:start position:0% +stop in the same bit of film means that +each film corresponds to a specific + + align:start position:0% +each film corresponds to a specific + + + align:start position:0% +each film corresponds to a specific +energy maybe the first film stack here + + align:start position:0% +energy maybe the first film stack here + + + align:start position:0% +energy maybe the first film stack here +corresponds to one Meb and the next one + + align:start position:0% +corresponds to one Meb and the next one + + + align:start position:0% +corresponds to one Meb and the next one +to two three four five six and so on you + + align:start position:0% +to two three four five six and so on you + + + align:start position:0% +to two three four five six and so on you +can put different filters between these + + align:start position:0% +can put different filters between these + + + align:start position:0% +can put different filters between these +to slow to to select different proton + + align:start position:0% +to slow to to select different proton + + + align:start position:0% +to slow to to select different proton +energies but it means that each of these + + align:start position:0% +energies but it means that each of these + + + align:start position:0% +energies but it means that each of these +bits of fil now corresponds to a + + align:start position:0% +bits of fil now corresponds to a + + + align:start position:0% +bits of fil now corresponds to a +different energy which is very useful if + + align:start position:0% +different energy which is very useful if + + + align:start position:0% +different energy which is very useful if +you want to do your multi-energy trick + + align:start position:0% +you want to do your multi-energy trick + + + align:start position:0% +you want to do your multi-energy trick +of unfolding the electric and magnetic + + align:start position:0% +of unfolding the electric and magnetic + + + align:start position:0% +of unfolding the electric and magnetic +fields so this first result of this is + + align:start position:0% +fields so this first result of this is + + + align:start position:0% +fields so this first result of this is +that we have + + align:start position:0% +that we have + + + align:start position:0% +that we have +uh uh we call it one + + align:start position:0% +uh uh we call it one + + + align:start position:0% +uh uh we call it one +energy per fi + + align:start position:0% +energy per fi + + + align:start position:0% +energy per fi +it's obviously not quite true because + + align:start position:0% +it's obviously not quite true because + + + align:start position:0% +it's obviously not quite true because +you have some bleed through some some + + align:start position:0% +you have some bleed through some some + + + align:start position:0% +you have some bleed through some some +particles which stopped early so there's + + align:start position:0% +particles which stopped early so there's + + + align:start position:0% +particles which stopped early so there's +a little bit of cross talk between them + + align:start position:0% +a little bit of cross talk between them + + + align:start position:0% +a little bit of cross talk between them +the other neat thing about this if you + + align:start position:0% +the other neat thing about this if you + + + align:start position:0% +the other neat thing about this if you +don't want to use these in order to back + + align:start position:0% +don't want to use these in order to back + + + align:start position:0% +don't want to use these in order to back +out the difference between electric and + + align:start position:0% +out the difference between electric and + + + align:start position:0% +out the difference between electric and +magnetic fields you can make a different + + align:start position:0% +magnetic fields you can make a different + + + align:start position:0% +magnetic fields you can make a different +argument and you can argue in fact that + + align:start position:0% +argument and you can argue in fact that + + + align:start position:0% +argument and you can argue in fact that +my particles were born here and they + + align:start position:0% +my particles were born here and they + + + align:start position:0% +my particles were born here and they +were born at different + + align:start position:0% +were born at different + + + align:start position:0% +were born at different +energies and they stream through this + + align:start position:0% +energies and they stream through this + + + align:start position:0% +energies and they stream through this +plasma here but that means that a + + align:start position:0% +plasma here but that means that a + + + align:start position:0% +plasma here but that means that a +particle going at 10 + + align:start position:0% +particle going at 10 + + + align:start position:0% +particle going at 10 +Meb reaches the plasma at time t0 so + + align:start position:0% +Meb reaches the plasma at time t0 so + + + align:start position:0% +Meb reaches the plasma at time t0 so +instead of 10 I'll write six because + + align:start position:0% +instead of 10 I'll write six because + + + align:start position:0% +instead of 10 I'll write six because +I've got six here so these particles all + + align:start position:0% +I've got six here so these particles all + + + align:start position:0% +I've got six here so these particles all +stream through at + + align:start position:0% +stream through at + + + align:start position:0% +stream through at +t0 but a particle at one me is going + + align:start position:0% +t0 but a particle at one me is going + + + align:start position:0% +t0 but a particle at one me is going +more slowly going six times more slowly + + align:start position:0% +more slowly going six times more slowly + + + align:start position:0% +more slowly going six times more slowly +modulos and relativistic stuff and so + + align:start position:0% +modulos and relativistic stuff and so + + + align:start position:0% +modulos and relativistic stuff and so +that means that this particle arrives at + + align:start position:0% +that means that this particle arrives at + + + align:start position:0% +that means that this particle arrives at +t0 plus delta T and so not only do the + + align:start position:0% +t0 plus delta T and so not only do the + + + align:start position:0% +t0 plus delta T and so not only do the +different energies maybe give you a way + + align:start position:0% +different energies maybe give you a way + + + align:start position:0% +different energies maybe give you a way +of unfolding the Electric magnetic + + align:start position:0% +of unfolding the Electric magnetic + + + align:start position:0% +of unfolding the Electric magnetic +fields the different energies are + + align:start position:0% +fields the different energies are + + + align:start position:0% +fields the different energies are +different slices in time so if this is + + align:start position:0% +different slices in time so if this is + + + align:start position:0% +different slices in time so if this is +energy in this direction it means that + + align:start position:0% +energy in this direction it means that + + + align:start position:0% +energy in this direction it means that +if you read the films back they + + align:start position:0% +if you read the films back they + + + align:start position:0% +if you read the films back they +correspond to time in this direction and + + align:start position:0% +correspond to time in this direction and + + + align:start position:0% +correspond to time in this direction and +so you can make a little movie of how + + align:start position:0% +so you can make a little movie of how + + + align:start position:0% +so you can make a little movie of how +your plasma revolves in time so that's + + align:start position:0% +your plasma revolves in time so that's + + + align:start position:0% +your plasma revolves in time so that's +really cool you get time resolution and + + align:start position:0% +really cool you get time resolution and + + + align:start position:0% +really cool you get time resolution and +the more different bits of film you have + + align:start position:0% +the more different bits of film you have + + + align:start position:0% +the more different bits of film you have +and The Wider range of energies you have + + align:start position:0% +and The Wider range of energies you have + + + align:start position:0% +and The Wider range of energies you have +the better time resolution you can get + + align:start position:0% +the better time resolution you can get + + + align:start position:0% +the better time resolution you can get +questions + + align:start position:0% + + + + align:start position:0% + +yep yeah the radiorc film isn't + + align:start position:0% +yep yeah the radiorc film isn't + + + align:start position:0% +yep yeah the radiorc film isn't +sensitive to other particles so yeah not + + align:start position:0% +sensitive to other particles so yeah not + + + align:start position:0% +sensitive to other particles so yeah not +to neutrons and gamas and things like + + align:start position:0% +to neutrons and gamas and things like + + + align:start position:0% +to neutrons and gamas and things like +that you can also yeah yeah in in this + + align:start position:0% +that you can also yeah yeah in in this + + + align:start position:0% +that you can also yeah yeah in in this +case I think it's almost that things + + align:start position:0% +case I think it's almost that things + + + align:start position:0% +case I think it's almost that things +like uh the lower energy particles and + + align:start position:0% +like uh the lower energy particles and + + + align:start position:0% +like uh the lower energy particles and +photons you could filter out and the + + align:start position:0% +photons you could filter out and the + + + align:start position:0% +photons you could filter out and the +high energy ones like gamma rays will + + align:start position:0% +high energy ones like gamma rays will + + + align:start position:0% +high energy ones like gamma rays will +just go straight through without + + align:start position:0% +just go straight through without + + + align:start position:0% +just go straight through without +interacting so this is pretty much just + + align:start position:0% +interacting so this is pretty much just + + + align:start position:0% +interacting so this is pretty much just +sensitive to the proton yeah that's a + + align:start position:0% +sensitive to the proton yeah that's a + + + align:start position:0% +sensitive to the proton yeah that's a +good + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% + + + + align:start position:0% + +yes it's the same thing so these the the + + align:start position:0% +yes it's the same thing so these the the + + + align:start position:0% +yes it's the same thing so these the the +protons are all emitted in a very very + + align:start position:0% +protons are all emitted in a very very + + + align:start position:0% +protons are all emitted in a very very +narrow burst okay yeah that's no that's + + align:start position:0% +narrow burst okay yeah that's no that's + + + align:start position:0% +narrow burst okay yeah that's no that's +that's a great that's a great thank you + + align:start position:0% +that's a great that's a great thank you + + + align:start position:0% +that's a great that's a great thank you +let have a little figure here of + + align:start position:0% +let have a little figure here of + + + align:start position:0% +let have a little figure here of +time and I don't know + + align:start position:0% + + + + align:start position:0% + +fluence so at Time Zero all of the + + align:start position:0% +fluence so at Time Zero all of the + + + align:start position:0% +fluence so at Time Zero all of the +protons are + + align:start position:0% +protons are + + + align:start position:0% +protons are +emitted very + + align:start position:0% +emitted very + + + align:start position:0% +emitted very +narrow remember this is Peak a second or + + align:start position:0% +narrow remember this is Peak a second or + + + align:start position:0% +narrow remember this is Peak a second or +f a second here so I could say this is + + align:start position:0% +f a second here so I could say this is + + + align:start position:0% +f a second here so I could say this is +Peak a second and maybe I've got two + + align:start position:0% +Peak a second and maybe I've got two + + + align:start position:0% +Peak a second and maybe I've got two +energies here the blue energy which is + + align:start position:0% +energies here the blue energy which is + + + align:start position:0% +energies here the blue energy which is +one me and the purple energy which is 10 + + align:start position:0% + + + + align:start position:0% + +MP they have to travel some distance + + align:start position:0% +MP they have to travel some distance + + + align:start position:0% +MP they have to travel some distance +from The Source through the plasma and + + align:start position:0% +from The Source through the plasma and + + + align:start position:0% +from The Source through the plasma and +they will go through it at different + + align:start position:0% +they will go through it at different + + + align:start position:0% +they will go through it at different +times the 10 m V1 will get there first + + align:start position:0% +times the 10 m V1 will get there first + + + align:start position:0% +times the 10 m V1 will get there first +and the one mv1 will get there second + + align:start position:0% +and the one mv1 will get there second + + + align:start position:0% +and the one mv1 will get there second +and then finally they will travel + + align:start position:0% +and then finally they will travel + + + align:start position:0% +and then finally they will travel +through the + + align:start position:0% +through the + + + align:start position:0% +through the +detector and they'll arrive there much + + align:start position:0% +detector and they'll arrive there much + + + align:start position:0% +detector and they'll arrive there much +later but we don't really care the + + align:start position:0% +later but we don't really care the + + + align:start position:0% +later but we don't really care the +detector is time integrating so it will + + align:start position:0% +detector is time integrating so it will + + + align:start position:0% +detector is time integrating so it will +see protons which sample the plasma at + + align:start position:0% +see protons which sample the plasma at + + + align:start position:0% +see protons which sample the plasma at +an earlier time uh sorry it will the the + + align:start position:0% +an earlier time uh sorry it will the the + + + align:start position:0% +an earlier time uh sorry it will the the +10 m film will see protons that sample + + align:start position:0% +10 m film will see protons that sample + + + align:start position:0% +10 m film will see protons that sample +the plasma earlier than the 1 M film + + align:start position:0% +the plasma earlier than the 1 M film + + + align:start position:0% +the plasma earlier than the 1 M film +yeah but you do actually have to have + + align:start position:0% +yeah but you do actually have to have + + + align:start position:0% +yeah but you do actually have to have +that requirement you have a very very + + align:start position:0% +that requirement you have a very very + + + align:start position:0% +that requirement you have a very very +short burst protons + + align:start position:0% + + + + align:start position:0% + +yeah yeah so you can only do one or the + + align:start position:0% +yeah yeah so you can only do one or the + + + align:start position:0% +yeah yeah so you can only do one or the +other you can either claim that there + + align:start position:0% +other you can either claim that there + + + align:start position:0% +other you can either claim that there +are like no electric fields and you know + + align:start position:0% +are like no electric fields and you know + + + align:start position:0% +are like no electric fields and you know +it's all magnetic fields and then you + + align:start position:0% +it's all magnetic fields and then you + + + align:start position:0% +it's all magnetic fields and then you +get a Time series or you can claim that + + align:start position:0% +get a Time series or you can claim that + + + align:start position:0% +get a Time series or you can claim that +um the plasma doesn't change in time and + + align:start position:0% +um the plasma doesn't change in time and + + + align:start position:0% +um the plasma doesn't change in time and +therefore you can use a different + + align:start position:0% +therefore you can use a different + + + align:start position:0% +therefore you can use a different +energies so you've got to be a little + + align:start position:0% +energies so you've got to be a little + + + align:start position:0% +energies so you've got to be a little +bit careful when you see someone + + align:start position:0% +bit careful when you see someone + + + align:start position:0% +bit careful when you see someone +claiming with proton radiography it's + + align:start position:0% +claiming with proton radiography it's + + + align:start position:0% +claiming with proton radiography it's +like it's difficult to do both but you + + align:start position:0% +like it's difficult to do both but you + + + align:start position:0% +like it's difficult to do both but you +might have like a simulation or some + + align:start position:0% +might have like a simulation or some + + + align:start position:0% +might have like a simulation or some +other experiment that suggests the + + align:start position:0% +other experiment that suggests the + + + align:start position:0% +other experiment that suggests the +electric fields are minimal in which + + align:start position:0% +electric fields are minimal in which + + + align:start position:0% +electric fields are minimal in which +case you can just say okay everything I + + align:start position:0% +case you can just say okay everything I + + + align:start position:0% +case you can just say okay everything I +see is due to magnetic fields now I have + + align:start position:0% +see is due to magnetic fields now I have + + + align:start position:0% +see is due to magnetic fields now I have +a time people will do that and maybe + + align:start position:0% +a time people will do that and maybe + + + align:start position:0% +a time people will do that and maybe +reason was there another question that I + + align:start position:0% +reason was there another question that I + + + align:start position:0% +reason was there another question that I +see okay let's talk about this second + + align:start position:0% +see okay let's talk about this second + + + align:start position:0% +see okay let's talk about this second +method uh which is an imploding capsule + + align:start position:0% + + + + align:start position:0% + +the second second method would be for + + align:start position:0% +the second second method would be for + + + align:start position:0% +the second second method would be for +example a d helium 3 + + align:start position:0% + + + + align:start position:0% + +implosion so this is literally a little + + align:start position:0% +implosion so this is literally a little + + + align:start position:0% +implosion so this is literally a little +inertial confinement Fusion Target here + + align:start position:0% +inertial confinement Fusion Target here + + + align:start position:0% +inertial confinement Fusion Target here +filled with uterum and helium 3 and you + + align:start position:0% +filled with uterum and helium 3 and you + + + align:start position:0% +filled with uterum and helium 3 and you +get a load of direct drive + + align:start position:0% +get a load of direct drive + + + align:start position:0% +get a load of direct drive +lasers pushing on + + align:start position:0% +lasers pushing on + + + align:start position:0% +lasers pushing on +it and making a nice symmetric + + align:start position:0% +it and making a nice symmetric + + + align:start position:0% +it and making a nice symmetric +is implosion of this and then when this + + align:start position:0% +is implosion of this and then when this + + + align:start position:0% +is implosion of this and then when this +implodes it's going to send out all of + + align:start position:0% +implodes it's going to send out all of + + + align:start position:0% +implodes it's going to send out all of +the particles that come from the fusion + + align:start position:0% +the particles that come from the fusion + + + align:start position:0% +the particles that come from the fusion +reaction between the duum and the helium + + align:start position:0% +reaction between the duum and the helium + + + align:start position:0% +reaction between the duum and the helium +3 so just to save for this you need to + + align:start position:0% +3 so just to save for this you need to + + + align:start position:0% +3 so just to save for this you need to +have multiple I'm going to write + + align:start position:0% +have multiple I'm going to write + + + align:start position:0% +have multiple I'm going to write +many kogle + + align:start position:0% +many kogle + + + align:start position:0% +many kogle +class beams with a one nanc pulse one + + align:start position:0% +class beams with a one nanc pulse one + + + align:start position:0% +class beams with a one nanc pulse one +nanc in the laser world is considered a + + align:start position:0% +nanc in the laser world is considered a + + + align:start position:0% +nanc in the laser world is considered a +long PSE right so these are much longer + + align:start position:0% +long PSE right so these are much longer + + + align:start position:0% +long PSE right so these are much longer +than PC andc these are long pulse + + align:start position:0% +than PC andc these are long pulse + + + align:start position:0% +than PC andc these are long pulse +lasers so the interesting thing is that + + align:start position:0% +lasers so the interesting thing is that + + + align:start position:0% +lasers so the interesting thing is that +this reaction produc prod es two + + align:start position:0% +this reaction produc prod es two + + + align:start position:0% +this reaction produc prod es two +different energies from it but only + + align:start position:0% + + + + align:start position:0% + +two we have the three + + align:start position:0% +two we have the three + + + align:start position:0% +two we have the three +MV DD + + align:start position:0% +MV DD + + + align:start position:0% +MV DD +protons remember we're not interested in + + align:start position:0% +protons remember we're not interested in + + + align:start position:0% +protons remember we're not interested in +neutrons there may be neutrons coming + + align:start position:0% +neutrons there may be neutrons coming + + + align:start position:0% +neutrons there may be neutrons coming +out but they're not being used for this + + align:start position:0% +out but they're not being used for this + + + align:start position:0% +out but they're not being used for this +Diagnostic and we have the + + align:start position:0% +Diagnostic and we have the + + + align:start position:0% +Diagnostic and we have the +14.7 me the helium + + align:start position:0% +14.7 me the helium + + + align:start position:0% +14.7 me the helium +3 protons as well so this could be a + + align:start position:0% +3 protons as well so this could be a + + + align:start position:0% +3 protons as well so this could be a +positive or a negative the positive is + + align:start position:0% +positive or a negative the positive is + + + align:start position:0% +positive or a negative the positive is +you know exactly what your particle + + align:start position:0% +you know exactly what your particle + + + align:start position:0% +you know exactly what your particle +energies are they're sort of set by + + align:start position:0% +energies are they're sort of set by + + + align:start position:0% +energies are they're sort of set by +Fusion they're going to be shifted a + + align:start position:0% +Fusion they're going to be shifted a + + + align:start position:0% +Fusion they're going to be shifted a +little bit because uh there's thermal + + align:start position:0% +little bit because uh there's thermal + + + align:start position:0% +little bit because uh there's thermal +motion here but roughly you know what + + align:start position:0% +motion here but roughly you know what + + + align:start position:0% +motion here but roughly you know what +the energies are exactly but it's good + + align:start position:0% +the energies are exactly but it's good + + + align:start position:0% +the energies are exactly but it's good +so the positive is we know the + + align:start position:0% + + + + align:start position:0% + +energy um the negative is there's only + + align:start position:0% + + + + align:start position:0% + +two people have recently add a little + + align:start position:0% +two people have recently add a little + + + align:start position:0% +two people have recently add a little +bit of spice in the form of some + + align:start position:0% +bit of spice in the form of some + + + align:start position:0% +bit of spice in the form of some +uh and then you also get the tritium + + align:start position:0% +uh and then you also get the tritium + + + align:start position:0% +uh and then you also get the tritium +helium 3 reaction which gives you a + + align:start position:0% +helium 3 reaction which gives you a + + + align:start position:0% +helium 3 reaction which gives you a +proton at 12 me so that gives you a tri + + align:start position:0% +proton at 12 me so that gives you a tri + + + align:start position:0% +proton at 12 me so that gives you a tri +particle source so that's nice now you + + align:start position:0% +particle source so that's nice now you + + + align:start position:0% +particle source so that's nice now you +have three particle so that's pretty + + align:start position:0% +have three particle so that's pretty + + + align:start position:0% +have three particle so that's pretty +good um another negative + + align:start position:0% +good um another negative + + + align:start position:0% +good um another negative +here is the spot + + align:start position:0% + + + + align:start position:0% + +size these implosions tend to get down + + align:start position:0% +size these implosions tend to get down + + + align:start position:0% +size these implosions tend to get down +to slightly larger sizes than you can + + align:start position:0% +to slightly larger sizes than you can + + + align:start position:0% +to slightly larger sizes than you can +reach with the focal spot for TNS say so + + align:start position:0% +reach with the focal spot for TNS say so + + + align:start position:0% +reach with the focal spot for TNS say so +the spot size is around about 40 microns + + align:start position:0% +the spot size is around about 40 microns + + + align:start position:0% +the spot size is around about 40 microns +or so it's not too much worse but it is + + align:start position:0% +or so it's not too much worse but it is + + + align:start position:0% +or so it's not too much worse but it is +significantly larger than the tnsa + + align:start position:0% +significantly larger than the tnsa + + + align:start position:0% +significantly larger than the tnsa +size the other problem is that we have + + align:start position:0% + + + + align:start position:0% + +isotropic + + align:start position:0% +isotropic + + + align:start position:0% +isotropic +emission so the nice thing about tnsa is + + align:start position:0% +emission so the nice thing about tnsa is + + + align:start position:0% +emission so the nice thing about tnsa is +all the particles are going roughly in + + align:start position:0% +all the particles are going roughly in + + + align:start position:0% +all the particles are going roughly in +the direction you want to here if your + + align:start position:0% +the direction you want to here if your + + + align:start position:0% +the direction you want to here if your +plasma is over here most of your + + align:start position:0% +plasma is over here most of your + + + align:start position:0% +plasma is over here most of your +particles are just flying off in + + align:start position:0% +particles are just flying off in + + + align:start position:0% +particles are just flying off in +completely random directions and you + + align:start position:0% +completely random directions and you + + + align:start position:0% +completely random directions and you +don't get to capture them at all um and + + align:start position:0% +don't get to capture them at all um and + + + align:start position:0% +don't get to capture them at all um and +so this means that we + + align:start position:0% +so this means that we + + + align:start position:0% +so this means that we +have few + + align:start position:0% + + + + align:start position:0% + +particles this is in contrast to tnsa + + align:start position:0% +particles this is in contrast to tnsa + + + align:start position:0% +particles this is in contrast to tnsa +where we were able to create a very + + align:start position:0% +where we were able to create a very + + + align:start position:0% +where we were able to create a very +large number of particles but the fact + + align:start position:0% +large number of particles but the fact + + + align:start position:0% +large number of particles but the fact +that we have very few particles also + + align:start position:0% +that we have very few particles also + + + align:start position:0% +that we have very few particles also +leads to a change in + + align:start position:0% + + + + align:start position:0% + +detector this is sort of the big + + align:start position:0% +detector this is sort of the big + + + align:start position:0% +detector this is sort of the big +Workhorse of the MIT group because they + + align:start position:0% +Workhorse of the MIT group because they + + + align:start position:0% +Workhorse of the MIT group because they +realized that they could use a detector + + align:start position:0% +realized that they could use a detector + + + align:start position:0% +realized that they could use a detector +called + + align:start position:0% +called + + + align:start position:0% +called +CR + + align:start position:0% +CR + + + align:start position:0% +CR +39 now cr39 is a + + align:start position:0% + + + + align:start position:0% + +polymer the interesting thing about it + + align:start position:0% +polymer the interesting thing about it + + + align:start position:0% +polymer the interesting thing about it +you have a sheet of cr39 you have a + + align:start position:0% +you have a sheet of cr39 you have a + + + align:start position:0% +you have a sheet of cr39 you have a +proton going through it is it causes a + + align:start position:0% +proton going through it is it causes a + + + align:start position:0% +proton going through it is it causes a +little area of damage a little track as + + align:start position:0% +little area of damage a little track as + + + align:start position:0% +little area of damage a little track as +a proton goes through and you can then + + align:start position:0% +a proton goes through and you can then + + + align:start position:0% +a proton goes through and you can then +dip your polymer after the shot in an + + align:start position:0% +dip your polymer after the shot in an + + + align:start position:0% +dip your polymer after the shot in an +etching solu + + align:start position:0% + + + + align:start position:0% + +and it turns each of these tracks into + + align:start position:0% +and it turns each of these tracks into + + + align:start position:0% +and it turns each of these tracks into +little holes so now if you look at your + + align:start position:0% +little holes so now if you look at your + + + align:start position:0% +little holes so now if you look at your +cr39 there's all sorts + + align:start position:0% +cr39 there's all sorts + + + align:start position:0% +cr39 there's all sorts +of little holes on + + align:start position:0% +of little holes on + + + align:start position:0% +of little holes on +it it turns out + + align:start position:0% +it it turns out + + + align:start position:0% +it it turns out +the size of the + + align:start position:0% + + + + align:start position:0% + +hole is in some way related to the + + align:start position:0% +hole is in some way related to the + + + align:start position:0% +hole is in some way related to the +energy so you can tell the difference + + align:start position:0% +energy so you can tell the difference + + + align:start position:0% +energy so you can tell the difference +between the 3 m and the 14 .7 + + align:start position:0% +between the 3 m and the 14 .7 + + + align:start position:0% +between the 3 m and the 14 .7 +Meb um and theoretically though again + + align:start position:0% +Meb um and theoretically though again + + + align:start position:0% +Meb um and theoretically though again +I'm not sure that anyone has done this + + align:start position:0% +I'm not sure that anyone has done this + + + align:start position:0% +I'm not sure that anyone has done this +since it was first suggested if you have + + align:start position:0% +since it was first suggested if you have + + + align:start position:0% +since it was first suggested if you have +multiple pieces of cr39 and protons are + + align:start position:0% +multiple pieces of cr39 and protons are + + + align:start position:0% +multiple pieces of cr39 and protons are +just going through it you should be able + + align:start position:0% +just going through it you should be able + + + align:start position:0% +just going through it you should be able +to the tracks in different bits of film + + align:start position:0% +to the tracks in different bits of film + + + align:start position:0% +to the tracks in different bits of film +and go aha the track in this bit of film + + align:start position:0% +and go aha the track in this bit of film + + + align:start position:0% +and go aha the track in this bit of film +is now over + + align:start position:0% +is now over + + + align:start position:0% +is now over +here and I should be able to work out + + align:start position:0% +here and I should be able to work out + + + align:start position:0% +here and I should be able to work out +the angle of the particles so you you + + align:start position:0% +the angle of the particles so you you + + + align:start position:0% +the angle of the particles so you you +may be able to correlate + + align:start position:0% +may be able to correlate + + + align:start position:0% +may be able to correlate +tracks but I'm not sure anyone actually + + align:start position:0% +tracks but I'm not sure anyone actually + + + align:start position:0% +tracks but I'm not sure anyone actually +used that as a serious diagnostic + + align:start position:0% +used that as a serious diagnostic + + + align:start position:0% +used that as a serious diagnostic +recently it's just in one of the early + + align:start position:0% +recently it's just in one of the early + + + align:start position:0% +recently it's just in one of the early +papers um so what do you actually do + + align:start position:0% +papers um so what do you actually do + + + align:start position:0% +papers um so what do you actually do +with all these tracks here well you set + + align:start position:0% +with all these tracks here well you set + + + align:start position:0% +with all these tracks here well you set +up a very good microscope and you put + + align:start position:0% +up a very good microscope and you put + + + align:start position:0% +up a very good microscope and you put +one of these bits of cr39 in and the + + align:start position:0% +one of these bits of cr39 in and the + + + align:start position:0% +one of these bits of cr39 in and the +microscope looks at a small square here + + align:start position:0% +microscope looks at a small square here + + + align:start position:0% +microscope looks at a small square here +and it counts all of the holes in this + + align:start position:0% +and it counts all of the holes in this + + + align:start position:0% +and it counts all of the holes in this +little square and this Square represents + + align:start position:0% +little square and this Square represents + + + align:start position:0% +little square and this Square represents +a pixel and it outputs for example 100 + + align:start position:0% +a pixel and it outputs for example 100 + + + align:start position:0% +a pixel and it outputs for example 100 +holes now it goes to the next + + align:start position:0% +holes now it goes to the next + + + align:start position:0% +holes now it goes to the next +one and it outputs 102 so it's + + align:start position:0% +one and it outputs 102 so it's + + + align:start position:0% +one and it outputs 102 so it's +effectively reading off the number of + + align:start position:0% +effectively reading off the number of + + + align:start position:0% +effectively reading off the number of +protons one by one individually + + align:start position:0% +protons one by one individually + + + align:start position:0% +protons one by one individually +automated but still individually and + + align:start position:0% +automated but still individually and + + + align:start position:0% +automated but still individually and +building up that intensity whereas the + + align:start position:0% +building up that intensity whereas the + + + align:start position:0% +building up that intensity whereas the +radiochromic film we don't know the + + align:start position:0% +radiochromic film we don't know the + + + align:start position:0% +radiochromic film we don't know the +exact number of protons we just have a + + align:start position:0% +exact number of protons we just have a + + + align:start position:0% +exact number of protons we just have a +different uh darkness of the film + + align:start position:0% +different uh darkness of the film + + + align:start position:0% +different uh darkness of the film +depending on the proton fluence here so + + align:start position:0% +depending on the proton fluence here so + + + align:start position:0% +depending on the proton fluence here so +I did a scientific poll at APS DPP 2021 + + align:start position:0% +I did a scientific poll at APS DPP 2021 + + + align:start position:0% +I did a scientific poll at APS DPP 2021 +three out of three physicists + + align:start position:0% + + + + align:start position:0% + +preferred I probably SP preferred wrong + + align:start position:0% +preferred I probably SP preferred wrong + + + align:start position:0% +preferred I probably SP preferred wrong +uh + + align:start position:0% +uh + + + align:start position:0% +uh +pnsa plus radiochromic + + align:start position:0% +pnsa plus radiochromic + + + align:start position:0% +pnsa plus radiochromic +Bill however there are many facilities + + align:start position:0% +Bill however there are many facilities + + + align:start position:0% +Bill however there are many facilities +which do not have a sufficiently + + align:start position:0% +which do not have a sufficiently + + + align:start position:0% +which do not have a sufficiently +powerful short pulse laser but they do + + align:start position:0% +powerful short pulse laser but they do + + + align:start position:0% +powerful short pulse laser but they do +have an awful lot of ker class laser + + align:start position:0% +have an awful lot of ker class laser + + + align:start position:0% +have an awful lot of ker class laser +beams floating around that they don't + + align:start position:0% +beams floating around that they don't + + + align:start position:0% +beams floating around that they don't +have to use so for example on Omega or + + align:start position:0% +have to use so for example on Omega or + + + align:start position:0% +have to use so for example on Omega or +on nith you have lots of these beams you + + align:start position:0% +on nith you have lots of these beams you + + + align:start position:0% +on nith you have lots of these beams you +can use some of the beams to drive your + + align:start position:0% +can use some of the beams to drive your + + + align:start position:0% +can use some of the beams to drive your +target plasma and the other beams to + + align:start position:0% +target plasma and the other beams to + + + align:start position:0% +target plasma and the other beams to +drive your imploding capsule and you'll + + align:start position:0% +drive your imploding capsule and you'll + + + align:start position:0% +drive your imploding capsule and you'll +still be able to do proton radiography + + align:start position:0% +still be able to do proton radiography + + + align:start position:0% +still be able to do proton radiography +so there's definitely a place for this + + align:start position:0% +so there's definitely a place for this + + + align:start position:0% +so there's definitely a place for this +technique it's just that it seems like + + align:start position:0% +technique it's just that it seems like + + + align:start position:0% +technique it's just that it seems like +people prefer in general + + align:start position:0% +people prefer in general + + + align:start position:0% +people prefer in general +tnsa okay + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +uh I don't know whether people have done + + align:start position:0% +uh I don't know whether people have done + + + align:start position:0% +uh I don't know whether people have done +that yeah possibly you need to have + + align:start position:0% +that yeah possibly you need to have + + + align:start position:0% +that yeah possibly you need to have +magnetic fields right in this and so in + + align:start position:0% +magnetic fields right in this and so in + + + align:start position:0% +magnetic fields right in this and so in +general people don't think too much + + align:start position:0% +general people don't think too much + + + align:start position:0% +general people don't think too much +about the magnetic fields in ICF but + + align:start position:0% +about the magnetic fields in ICF but + + + align:start position:0% +about the magnetic fields in ICF but +might be there there are mechanisms + + align:start position:0% +might be there there are mechanisms + + + align:start position:0% +might be there there are mechanisms +which could self-generate the field like + + align:start position:0% +which could self-generate the field like + + + align:start position:0% +which could self-generate the field like +B and Battery I don't know if anyone's + + align:start position:0% +B and Battery I don't know if anyone's + + + align:start position:0% +B and Battery I don't know if anyone's +done that but it could be done I imagine + + align:start position:0% +done that but it could be done I imagine + + + align:start position:0% +done that but it could be done I imagine +it's then complicated you have to work + + align:start position:0% +it's then complicated you have to work + + + align:start position:0% +it's then complicated you have to work +out exactly what you're measuring but + + align:start position:0% +out exactly what you're measuring but + + + align:start position:0% +out exactly what you're measuring but +yeah an interesting idea sorry yeah + + align:start position:0% + + + + align:start position:0% + +sure + + align:start position:0% + + + + align:start position:0% + +yeah oh we do alpha + + align:start position:0% + + + + align:start position:0% + +particles yeah I would have thought that + + align:start position:0% +particles yeah I would have thought that + + + align:start position:0% +particles yeah I would have thought that +the energy is the the velocity is a fair + + align:start position:0% +the energy is the the velocity is a fair + + + align:start position:0% +the energy is the the velocity is a fair +bit lower because of the higher Mass + + align:start position:0% +bit lower because of the higher Mass + + + align:start position:0% +bit lower because of the higher Mass +yeah um I don't know exactly so good + + align:start position:0% +yeah um I don't know exactly so good + + + align:start position:0% +yeah um I don't know exactly so good +question I mean in general the reason + + align:start position:0% +question I mean in general the reason + + + align:start position:0% +question I mean in general the reason +why people haven't put tritium in is you + + align:start position:0% +why people haven't put tritium in is you + + + align:start position:0% +why people haven't put tritium in is you +know you don't necessarily want to keep + + align:start position:0% +know you don't necessarily want to keep + + + align:start position:0% +know you don't necessarily want to keep +playing with tritium so this is + + align:start position:0% +playing with tritium so this is + + + align:start position:0% +playing with tritium so this is +relatively easy to fill this capsule and + + align:start position:0% +relatively easy to fill this capsule and + + + align:start position:0% +relatively easy to fill this capsule and +this is just like a pain in the ass so + + align:start position:0% +this is just like a pain in the ass so + + + align:start position:0% +this is just like a pain in the ass so +it's not like everyone has rushed out to + + align:start position:0% +it's not like everyone has rushed out to + + + align:start position:0% +it's not like everyone has rushed out to +start doing the triar thing yeah okay + + align:start position:0% +start doing the triar thing yeah okay + + + align:start position:0% +start doing the triar thing yeah okay +other questions anything + + align:start position:0% + + + + align:start position:0% + +online + + align:start position:0% +online + + + align:start position:0% +online +okay now we'll go through some issues + + align:start position:0% +okay now we'll go through some issues + + + align:start position:0% +okay now we'll go through some issues +with doing this diagnostic practically + + align:start position:0% +with doing this diagnostic practically + + + align:start position:0% +with doing this diagnostic practically +we've got our source we've got our + + align:start position:0% +we've got our source we've got our + + + align:start position:0% +we've got our source we've got our +detector we understand how to make a map + + align:start position:0% +detector we understand how to make a map + + + align:start position:0% +detector we understand how to make a map +of the intensity after the plasma but + + align:start position:0% +of the intensity after the plasma but + + + align:start position:0% +of the intensity after the plasma but +are there any problems with doing that + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +issue + + align:start position:0% +issue + + + align:start position:0% +issue +one this + + align:start position:0% +one this + + + align:start position:0% +one this +condition that our beam was + + align:start position:0% + + + + align:start position:0% + +uniform remember we need that because + + align:start position:0% +uniform remember we need that because + + + align:start position:0% +uniform remember we need that because +we're trying to + + align:start position:0% +we're trying to + + + align:start position:0% +we're trying to +determine from I equals i z over the + + align:start position:0% +determine from I equals i z over the + + + align:start position:0% +determine from I equals i z over the +size of the Jacobian and remember the + + align:start position:0% +size of the Jacobian and remember the + + + align:start position:0% +size of the Jacobian and remember the +Jacobian is the thing that has all the + + align:start position:0% +Jacobian is the thing that has all the + + + align:start position:0% +Jacobian is the thing that has all the +physics in + + align:start position:0% + + + + align:start position:0% + +if we want to work out what the size of + + align:start position:0% +if we want to work out what the size of + + + align:start position:0% +if we want to work out what the size of +the Jacobian is we are measuring I but + + align:start position:0% +the Jacobian is we are measuring I but + + + align:start position:0% +the Jacobian is we are measuring I but +we need to make some asum out what I + + align:start position:0% +we need to make some asum out what I + + + align:start position:0% +we need to make some asum out what I +zero is we can't measure it because we + + align:start position:0% +zero is we can't measure it because we + + + align:start position:0% +zero is we can't measure it because we +do the target normal sheath acceleration + + align:start position:0% +do the target normal sheath acceleration + + + align:start position:0% +do the target normal sheath acceleration +through the plasma we can't put a beam + + align:start position:0% +through the plasma we can't put a beam + + + align:start position:0% +through the plasma we can't put a beam +splitter in and measure what the protons + + align:start position:0% +splitter in and measure what the protons + + + align:start position:0% +splitter in and measure what the protons +look like if we don't have beam + + align:start position:0% +look like if we don't have beam + + + align:start position:0% +look like if we don't have beam +Splitters protons so knowing I zero and + + align:start position:0% +Splitters protons so knowing I zero and + + + align:start position:0% +Splitters protons so knowing I zero and +knowing that it's uniform is very very + + align:start position:0% +knowing that it's uniform is very very + + + align:start position:0% +knowing that it's uniform is very very +difficult and so you could say well what + + align:start position:0% +difficult and so you could say well what + + + align:start position:0% +difficult and so you could say well what +if I have reproducibility what if I do + + align:start position:0% +if I have reproducibility what if I do + + + align:start position:0% +if I have reproducibility what if I do +the tnsa over and over again and I + + align:start position:0% +the tnsa over and over again and I + + + align:start position:0% +the tnsa over and over again and I +measure it without any plasma and I see + + align:start position:0% +measure it without any plasma and I see + + + align:start position:0% +measure it without any plasma and I see +that it's uniform well the trouble is we + + align:start position:0% +that it's uniform well the trouble is we + + + align:start position:0% +that it's uniform well the trouble is we +see that is not uniform right so we have + + align:start position:0% +see that is not uniform right so we have + + + align:start position:0% +see that is not uniform right so we have +poor + + align:start position:0% + + + + align:start position:0% + +reproducibility so a solution to + + align:start position:0% + + + + align:start position:0% + +this is that you include a grid in your + + align:start position:0% +this is that you include a grid in your + + + align:start position:0% +this is that you include a grid in your +system you still have your point source + + align:start position:0% +system you still have your point source + + + align:start position:0% +system you still have your point source +and your protons + + align:start position:0% +and your protons + + + align:start position:0% +and your protons +scaming out through your plasma but on + + align:start position:0% +scaming out through your plasma but on + + + align:start position:0% +scaming out through your plasma but on +the other side of the + + align:start position:0% +the other side of the + + + align:start position:0% +the other side of the +plasma you put a grid like this so in + + align:start position:0% +plasma you put a grid like this so in + + + align:start position:0% +plasma you put a grid like this so in +the absence of the plasma this splits up + + align:start position:0% +the absence of the plasma this splits up + + + align:start position:0% +the absence of the plasma this splits up +your beam into a series of beam looks so + + align:start position:0% +your beam into a series of beam looks so + + + align:start position:0% +your beam into a series of beam looks so +for example we have regions where the + + align:start position:0% +for example we have regions where the + + + align:start position:0% +for example we have regions where the +protons can pass through the grid I'm + + align:start position:0% +protons can pass through the grid I'm + + + align:start position:0% +protons can pass through the grid I'm +just going to draw nine of them here and + + align:start position:0% +just going to draw nine of them here and + + + align:start position:0% +just going to draw nine of them here and +we effectively have little points on a + + align:start position:0% +we effectively have little points on a + + + align:start position:0% +we effectively have little points on a +grid like this this is the case without + + align:start position:0% +grid like this this is the case without + + + align:start position:0% +grid like this this is the case without +plasma + + align:start position:0% + + + + align:start position:0% + +now when the plasma is present these + + align:start position:0% +now when the plasma is present these + + + align:start position:0% +now when the plasma is present these +protons are going to be deflected in + + align:start position:0% +protons are going to be deflected in + + + align:start position:0% +protons are going to be deflected in +different ways and we'll see these + + align:start position:0% +different ways and we'll see these + + + align:start position:0% +different ways and we'll see these +points move so for example this point + + align:start position:0% +points move so for example this point + + + align:start position:0% +points move so for example this point +might move to here this point might move + + align:start position:0% +might move to here this point might move + + + align:start position:0% +might move to here this point might move +to here this point might move to + + align:start position:0% + + + + align:start position:0% + +here and actually + + align:start position:0% +here and actually + + + align:start position:0% +here and actually +we can now directly + + align:start position:0% +we can now directly + + + align:start position:0% +we can now directly +calculate the deflection angle Alpha and + + align:start position:0% +calculate the deflection angle Alpha and + + + align:start position:0% +calculate the deflection angle Alpha and +therefore back out the electric and + + align:start position:0% +therefore back out the electric and + + + align:start position:0% +therefore back out the electric and +magnetic field from this technique so + + align:start position:0% +magnetic field from this technique so + + + align:start position:0% +magnetic field from this technique so +this is very good because we uh can + + align:start position:0% +this is very good because we uh can + + + align:start position:0% +this is very good because we uh can +calculate Alpha + + align:start position:0% + + + + align:start position:0% + +directly but the downside of it is we + + align:start position:0% +directly but the downside of it is we + + + align:start position:0% +directly but the downside of it is we +have very low spatial resolution + + align:start position:0% +have very low spatial resolution + + + align:start position:0% +have very low spatial resolution +now because you've gone from having a + + align:start position:0% +now because you've gone from having a + + + align:start position:0% +now because you've gone from having a +Contin image into a discret image + + align:start position:0% +Contin image into a discret image + + + align:start position:0% +Contin image into a discret image +instead but this technique is still very + + align:start position:0% +instead but this technique is still very + + + align:start position:0% +instead but this technique is still very +powerful because it does give you a + + align:start position:0% +powerful because it does give you a + + + align:start position:0% +powerful because it does give you a +direct handle on Alpha without needing + + align:start position:0% +direct handle on Alpha without needing + + + align:start position:0% +direct handle on Alpha without needing +to know what i z was + + align:start position:0% +to know what i z was + + + align:start position:0% +to know what i z was +okay the second + + align:start position:0% +okay the second + + + align:start position:0% +okay the second +issue I want to talk + + align:start position:0% + + + + align:start position:0% + +about is if we had have a + + align:start position:0% + + + + align:start position:0% + +uniform magnetic + + align:start position:0% +uniform magnetic + + + align:start position:0% +uniform magnetic +field as well as some varing magnetic + + align:start position:0% + + + + align:start position:0% + +fields we have a uniform magnetic field + + align:start position:0% +fields we have a uniform magnetic field + + + align:start position:0% +fields we have a uniform magnetic field +all of the particles are going to be + + align:start position:0% +all of the particles are going to be + + + align:start position:0% +all of the particles are going to be +swept in the same direction as + + align:start position:0% + + + + align:start position:0% + +well it's actually extremely hard to + + align:start position:0% +well it's actually extremely hard to + + + align:start position:0% +well it's actually extremely hard to +align these detectors and know exactly + + align:start position:0% +align these detectors and know exactly + + + align:start position:0% +align these detectors and know exactly +where the center is because we're + + align:start position:0% +where the center is because we're + + + align:start position:0% +where the center is because we're +talking about like submillimeter + + align:start position:0% +talking about like submillimeter + + + align:start position:0% +talking about like submillimeter +Precision so if you see this + + align:start position:0% +Precision so if you see this + + + align:start position:0% +Precision so if you see this +grid + + align:start position:0% + + + + align:start position:0% + +initially you see a grid like that that + + align:start position:0% +initially you see a grid like that that + + + align:start position:0% +initially you see a grid like that that +could be a grid that's been formed + + align:start position:0% +could be a grid that's been formed + + + align:start position:0% +could be a grid that's been formed +without any background magnetic field or + + align:start position:0% +without any background magnetic field or + + + align:start position:0% +without any background magnetic field or +it could be a grid that's been displaced + + align:start position:0% +it could be a grid that's been displaced + + + align:start position:0% +it could be a grid that's been displaced +some distance by background magnetic + + align:start position:0% +some distance by background magnetic + + + align:start position:0% +some distance by background magnetic +field you're not going to be able to + + align:start position:0% +field you're not going to be able to + + + align:start position:0% +field you're not going to be able to +tell the difference between those two so + + align:start position:0% +tell the difference between those two so + + + align:start position:0% +tell the difference between those two so +you cannot measure this background + + align:start position:0% +you cannot measure this background + + + align:start position:0% +you cannot measure this background +magnetic field and in many experiments + + align:start position:0% +magnetic field and in many experiments + + + align:start position:0% +magnetic field and in many experiments +where this is externally applied with + + align:start position:0% +where this is externally applied with + + + align:start position:0% +where this is externally applied with +some magnetic + + align:start position:0% +some magnetic + + + align:start position:0% +some magnetic +coils they really want to be able to + + align:start position:0% +coils they really want to be able to + + + align:start position:0% +coils they really want to be able to +measure that background magnetic field + + align:start position:0% +measure that background magnetic field + + + align:start position:0% +measure that background magnetic field +externally + + align:start position:0% + + + + align:start position:0% + +applied so a very neat + + align:start position:0% +applied so a very neat + + + align:start position:0% +applied so a very neat +technique that's come up recently is to + + align:start position:0% +technique that's come up recently is to + + + align:start position:0% +technique that's come up recently is to +use a second detector which is sensitive + + align:start position:0% +use a second detector which is sensitive + + + align:start position:0% +use a second detector which is sensitive +to the x-rays here so the idea once + + align:start position:0% +to the x-rays here so the idea once + + + align:start position:0% +to the x-rays here so the idea once +again is that we have our source of + + align:start position:0% + + + + align:start position:0% + +protons but alongside the protons we're + + align:start position:0% +protons but alongside the protons we're + + + align:start position:0% +protons but alongside the protons we're +also going to have a source of x-rays + + align:start position:0% +also going to have a source of x-rays + + + align:start position:0% +also going to have a source of x-rays +because this thing is + + align:start position:0% +because this thing is + + + align:start position:0% +because this thing is +hot and in this case I drew the mesh + + align:start position:0% +hot and in this case I drew the mesh + + + align:start position:0% +hot and in this case I drew the mesh +afterwards some of you may have realized + + align:start position:0% +afterwards some of you may have realized + + + align:start position:0% +afterwards some of you may have realized +I think the mesh needs to be + + align:start position:0% + + + + align:start position:0% + +before now we have our mesh + + align:start position:0% +before now we have our mesh + + + align:start position:0% +before now we have our mesh +again here and we have our + + align:start position:0% +again here and we have our + + + align:start position:0% +again here and we have our +plasma and the neat thing is we have our + + align:start position:0% +plasma and the neat thing is we have our + + + align:start position:0% +plasma and the neat thing is we have our +for example our RCF which is sensitive + + align:start position:0% +for example our RCF which is sensitive + + + align:start position:0% +for example our RCF which is sensitive +to the protons and we have some image + + align:start position:0% +to the protons and we have some image + + + align:start position:0% +to the protons and we have some image +plate which is sensitive to the + + align:start position:0% + + + + align:start position:0% + +x-rays then Although our protons will be + + align:start position:0% +x-rays then Although our protons will be + + + align:start position:0% +x-rays then Although our protons will be +swept up by magnetic fields and do all + + align:start position:0% +swept up by magnetic fields and do all + + + align:start position:0% +swept up by magnetic fields and do all +sorts of strange + + align:start position:0% + + + + align:start position:0% + +things the electron the x-rays are just + + align:start position:0% +things the electron the x-rays are just + + + align:start position:0% +things the electron the x-rays are just +going to go in straight lines which are + + align:start position:0% +going to go in straight lines which are + + + align:start position:0% +going to go in straight lines which are +completely + + align:start position:0% +completely + + + align:start position:0% +completely +unaffected by uh any magnetic fields + + align:start position:0% +unaffected by uh any magnetic fields + + + align:start position:0% +unaffected by uh any magnetic fields +here so we're going to use high energy + + align:start position:0% +here so we're going to use high energy + + + align:start position:0% +here so we're going to use high energy +x-rays here such that the refractive + + align:start position:0% +x-rays here such that the refractive + + + align:start position:0% +x-rays here such that the refractive +index at like 10 kilo electron volts is + + align:start position:0% +index at like 10 kilo electron volts is + + + align:start position:0% +index at like 10 kilo electron volts is +roughly one and so we don't see any + + align:start position:0% +roughly one and so we don't see any + + + align:start position:0% +roughly one and so we don't see any +refraction of the X-rays and so that + + align:start position:0% +refraction of the X-rays and so that + + + align:start position:0% +refraction of the X-rays and so that +means what we end up with + + align:start position:0% +means what we end up with + + + align:start position:0% +means what we end up with +is we'll have a grid the X-ray + + align:start position:0% + + + + align:start position:0% + +points in the absence of any background + + align:start position:0% +points in the absence of any background + + + align:start position:0% +points in the absence of any background +magnetic field and in the absence of any + + align:start position:0% +magnetic field and in the absence of any + + + align:start position:0% +magnetic field and in the absence of any +plasma we should see all of the protons + + align:start position:0% +plasma we should see all of the protons + + + align:start position:0% +plasma we should see all of the protons +end up in the same place as the x-rays + + align:start position:0% +end up in the same place as the x-rays + + + align:start position:0% +end up in the same place as the x-rays +if there is some uniform magnetic field + + align:start position:0% +if there is some uniform magnetic field + + + align:start position:0% +if there is some uniform magnetic field +that will shift all the + + align:start position:0% +that will shift all the + + + align:start position:0% +that will shift all the +protons like this this is + + align:start position:0% + + + + align:start position:0% + +uniform and then if there's a uniform + + align:start position:0% +uniform and then if there's a uniform + + + align:start position:0% +uniform and then if there's a uniform +magnetic field plus a a of magnetic + + align:start position:0% +magnetic field plus a a of magnetic + + + align:start position:0% +magnetic field plus a a of magnetic +field it will further shift them on top + + align:start position:0% +field it will further shift them on top + + + align:start position:0% +field it will further shift them on top +of + + align:start position:0% +of + + + align:start position:0% +of +that + + align:start position:0% +that + + + align:start position:0% +that +so the X-ray grid acts as a really nice + + align:start position:0% +so the X-ray grid acts as a really nice + + + align:start position:0% +so the X-ray grid acts as a really nice +fiducial uh it allows us to directly + + align:start position:0% +fiducial uh it allows us to directly + + + align:start position:0% +fiducial uh it allows us to directly +measure the deflections without having + + align:start position:0% +measure the deflections without having + + + align:start position:0% +measure the deflections without having +to worry about the uniform magnetic + + align:start position:0% +to worry about the uniform magnetic + + + align:start position:0% +to worry about the uniform magnetic +field screwing things up so this is very + + align:start position:0% +field screwing things up so this is very + + + align:start position:0% +field screwing things up so this is very +nice bit of work uh by Johnson and + + align:start position:0% +nice bit of work uh by Johnson and + + + align:start position:0% +nice bit of work uh by Johnson and +others and this is in review of + + align:start position:0% +others and this is in review of + + + align:start position:0% +others and this is in review of +scientific instruments published last + + align:start position:0% + + + + align:start position:0% + +year \ No newline at end of file diff --git a/GrrEdi84cV4.txt b/GrrEdi84cV4.txt new file mode 100644 index 0000000000000000000000000000000000000000..127b19b55d7e6950dcfe3b259fbdc60b18c2d019 --- /dev/null +++ b/GrrEdi84cV4.txt @@ -0,0 +1,451 @@ +align:start position:0% + +as I mentioned I'm diabetic and one + + align:start position:0% +as I mentioned I'm diabetic and one + + + align:start position:0% +as I mentioned I'm diabetic and one +things that I noticed in my dad before + + align:start position:0% +things that I noticed in my dad before + + + align:start position:0% +things that I noticed in my dad before +he knew he was diabetic he had come home + + align:start position:0% +he knew he was diabetic he had come home + + + align:start position:0% +he knew he was diabetic he had come home +from the train at night and my sister + + align:start position:0% +from the train at night and my sister + + + align:start position:0% +from the train at night and my sister +and I would rub his legs because they + + align:start position:0% +and I would rub his legs because they + + + align:start position:0% +and I would rub his legs because they +hurt this is one of the problems with + + align:start position:0% +hurt this is one of the problems with + + + align:start position:0% +hurt this is one of the problems with +diabetics his feet hurt and I remember + + align:start position:0% +diabetics his feet hurt and I remember + + + align:start position:0% +diabetics his feet hurt and I remember +my sister Nancy saying once gee daddy + + align:start position:0% +my sister Nancy saying once gee daddy + + + align:start position:0% +my sister Nancy saying once gee daddy +smells like mommy's nail polish remover + + align:start position:0% +smells like mommy's nail polish remover + + + align:start position:0% +smells like mommy's nail polish remover +which was acetone okay and acetone is + + align:start position:0% +which was acetone okay and acetone is + + + align:start position:0% +which was acetone okay and acetone is +one of the three ketone bodies the other + + align:start position:0% +one of the three ketone bodies the other + + + align:start position:0% +one of the three ketone bodies the other +two being beta-hydroxybutyrate acid and + + align:start position:0% +two being beta-hydroxybutyrate acid and + + + align:start position:0% +two being beta-hydroxybutyrate acid and +acetoacetate so what happens in diabetes + + align:start position:0% +acetoacetate so what happens in diabetes + + + align:start position:0% +acetoacetate so what happens in diabetes +is you know the diabetic doesn't have + + align:start position:0% +is you know the diabetic doesn't have + + + align:start position:0% +is you know the diabetic doesn't have +ample carbohydrate reserves within their + + align:start position:0% +ample carbohydrate reserves within their + + + align:start position:0% +ample carbohydrate reserves within their +cells as glycogen so they're you doing a + + align:start position:0% +cells as glycogen so they're you doing a + + + align:start position:0% +cells as glycogen so they're you doing a +lot of fatty acid oxidation rather than + + align:start position:0% +lot of fatty acid oxidation rather than + + + align:start position:0% +lot of fatty acid oxidation rather than +carbohydrate metabolism if you take a + + align:start position:0% +carbohydrate metabolism if you take a + + + align:start position:0% +carbohydrate metabolism if you take a +fatty acid and you break it down to ask + + align:start position:0% +fatty acid and you break it down to ask + + + align:start position:0% +fatty acid and you break it down to ask +the Toa + + align:start position:0% +the Toa + + + align:start position:0% +the Toa +the last steps called beta kita thiolase + + align:start position:0% +the last steps called beta kita thiolase + + + align:start position:0% +the last steps called beta kita thiolase +backs up then your two carbons of acetic + + align:start position:0% +backs up then your two carbons of acetic + + + align:start position:0% +backs up then your two carbons of acetic +away will be four carbons of + + align:start position:0% +away will be four carbons of + + + align:start position:0% +away will be four carbons of +acetoacetate and then that acetoacetate + + align:start position:0% +acetoacetate and then that acetoacetate + + + align:start position:0% +acetoacetate and then that acetoacetate +a third acetic we can add to it to form + + align:start position:0% +a third acetic we can add to it to form + + + align:start position:0% +a third acetic we can add to it to form +what's called hydroxymethyl glute a real + + align:start position:0% +what's called hydroxymethyl glute a real + + + align:start position:0% +what's called hydroxymethyl glute a real +coenzyme a okay hmg-coa and then + + align:start position:0% +coenzyme a okay hmg-coa and then + + + align:start position:0% +coenzyme a okay hmg-coa and then +rearrangements can happen they give rise + + align:start position:0% +rearrangements can happen they give rise + + + align:start position:0% +rearrangements can happen they give rise +altum Utley to the to the three ketone + + align:start position:0% +altum Utley to the to the three ketone + + + align:start position:0% +altum Utley to the to the three ketone +bodies acetoacetate beta hydroxy + + align:start position:0% +bodies acetoacetate beta hydroxy + + + align:start position:0% +bodies acetoacetate beta hydroxy +butyrate and acetone so in situations + + align:start position:0% +butyrate and acetone so in situations + + + align:start position:0% +butyrate and acetone so in situations +where of starvation and diabetes is + + align:start position:0% +where of starvation and diabetes is + + + align:start position:0% +where of starvation and diabetes is +basically my cells we're in a technical + + align:start position:0% +basically my cells we're in a technical + + + align:start position:0% +basically my cells we're in a technical +state of starvation in a case of + + align:start position:0% +state of starvation in a case of + + + align:start position:0% +state of starvation in a case of +starvation what happens is you you're + + align:start position:0% +starvation what happens is you you're + + + align:start position:0% +starvation what happens is you you're +you get this backup of the lipid + + align:start position:0% +you get this backup of the lipid + + + align:start position:0% +you get this backup of the lipid +breakdown or catabolism pathway and then + + align:start position:0% +breakdown or catabolism pathway and then + + + align:start position:0% +breakdown or catabolism pathway and then +these ketone bodies flush out into your + + align:start position:0% +these ketone bodies flush out into your + + + align:start position:0% +these ketone bodies flush out into your +blood in starvation situations the + + align:start position:0% +blood in starvation situations the + + + align:start position:0% +blood in starvation situations the +ketone bodies will act as fuels for your + + align:start position:0% +ketone bodies will act as fuels for your + + + align:start position:0% +ketone bodies will act as fuels for your +your your brain and other organs it's a + + align:start position:0% +your your brain and other organs it's a + + + align:start position:0% +your your brain and other organs it's a +it's a difficult transition but ketone + + align:start position:0% +it's a difficult transition but ketone + + + align:start position:0% +it's a difficult transition but ketone +bodies are are in the case of diabetics + + align:start position:0% +bodies are are in the case of diabetics + + + align:start position:0% +bodies are are in the case of diabetics +they're produced to access to such a + + align:start position:0% +they're produced to access to such a + + + align:start position:0% +they're produced to access to such a +stand + + align:start position:0% +stand + + + align:start position:0% +stand +that they're they're actually quite + + align:start position:0% +that they're they're actually quite + + + align:start position:0% +that they're they're actually quite +harmful to you the reason a person + + align:start position:0% +harmful to you the reason a person + + + align:start position:0% +harmful to you the reason a person +smells of acetone is the intermediate + + align:start position:0% +smells of acetone is the intermediate + + + align:start position:0% +smells of acetone is the intermediate +ketone body the acetoacetate basically D + + align:start position:0% +ketone body the acetoacetate basically D + + + align:start position:0% +ketone body the acetoacetate basically D +carboxylates it's a beta keto acid and + + align:start position:0% +carboxylates it's a beta keto acid and + + + align:start position:0% +carboxylates it's a beta keto acid and +so it's a spontaneous decomposition to + + align:start position:0% +so it's a spontaneous decomposition to + + + align:start position:0% +so it's a spontaneous decomposition to +form acetone acetone is not to my + + align:start position:0% +form acetone acetone is not to my + + + align:start position:0% +form acetone acetone is not to my +knowledge + + align:start position:0% +knowledge + + + align:start position:0% +knowledge +biochemically useful as a kind of an + + align:start position:0% +biochemically useful as a kind of an + + + align:start position:0% +biochemically useful as a kind of an +energy source but it's a sentinel or + + align:start position:0% +energy source but it's a sentinel or + + + align:start position:0% +energy source but it's a sentinel or +it's something that is smelled so that + + align:start position:0% +it's something that is smelled so that + + + align:start position:0% +it's something that is smelled so that +it can be diagnostic of the disease \ No newline at end of file diff --git a/GtuMlWMajtw.txt b/GtuMlWMajtw.txt new file mode 100644 index 0000000000000000000000000000000000000000..bbabb8f7ae645a693827a219db481f8d24c0cd95 --- /dev/null +++ b/GtuMlWMajtw.txt @@ -0,0 +1,2283 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +while working in the laboratory you will + + align:start position:0% +while working in the laboratory you will + + + align:start position:0% +while working in the laboratory you will +often be required to separate liquid + + align:start position:0% +often be required to separate liquid + + + align:start position:0% +often be required to separate liquid +mixtures or to purify liquid from + + align:start position:0% +mixtures or to purify liquid from + + + align:start position:0% +mixtures or to purify liquid from +nonvolatile substances this separation + + align:start position:0% +nonvolatile substances this separation + + + align:start position:0% +nonvolatile substances this separation +or purification can be done by utilizing + + align:start position:0% +or purification can be done by utilizing + + + align:start position:0% +or purification can be done by utilizing +the liquid's boiling point through a + + align:start position:0% +the liquid's boiling point through a + + + align:start position:0% +the liquid's boiling point through a +technique called + + align:start position:0% +technique called + + + align:start position:0% +technique called +distillation distillation Works through + + align:start position:0% +distillation distillation Works through + + + align:start position:0% +distillation distillation Works through +the processes of vapor ation and + + align:start position:0% +the processes of vapor ation and + + + align:start position:0% +the processes of vapor ation and +condensation vaporization is a + + align:start position:0% +condensation vaporization is a + + + align:start position:0% +condensation vaporization is a +transformation of a liquid to a gas and + + align:start position:0% +transformation of a liquid to a gas and + + + align:start position:0% +transformation of a liquid to a gas and +condensation is the conversion of a gous + + align:start position:0% +condensation is the conversion of a gous + + + align:start position:0% +condensation is the conversion of a gous +species into a + + align:start position:0% +species into a + + + align:start position:0% +species into a +liquid to perform a distillation a + + align:start position:0% +liquid to perform a distillation a + + + align:start position:0% +liquid to perform a distillation a +mixture of two missible liquids is + + align:start position:0% +mixture of two missible liquids is + + + align:start position:0% +mixture of two missible liquids is +heated until the liquid with the higher + + align:start position:0% +heated until the liquid with the higher + + + align:start position:0% +heated until the liquid with the higher +vapor pressure reaches its boiling point + + align:start position:0% +vapor pressure reaches its boiling point + + + align:start position:0% +vapor pressure reaches its boiling point +this Vapor travels up the inside of the + + align:start position:0% +this Vapor travels up the inside of the + + + align:start position:0% +this Vapor travels up the inside of the +flask through a distilling head and into + + align:start position:0% +flask through a distilling head and into + + + align:start position:0% +flask through a distilling head and into +a condenser the cold water jacket on the + + align:start position:0% +a condenser the cold water jacket on the + + + align:start position:0% +a condenser the cold water jacket on the +condenser transforms The Vapor back into + + align:start position:0% +condenser transforms The Vapor back into + + + align:start position:0% +condenser transforms The Vapor back into +liquid which then travels into the + + align:start position:0% +liquid which then travels into the + + + align:start position:0% +liquid which then travels into the +receiving flask in this manner + + align:start position:0% +receiving flask in this manner + + + align:start position:0% +receiving flask in this manner +distillation effectively separates lower + + align:start position:0% +distillation effectively separates lower + + + align:start position:0% +distillation effectively separates lower +boiling point compounds from higher + + align:start position:0% +boiling point compounds from higher + + + align:start position:0% +boiling point compounds from higher +boiling point + + align:start position:0% +boiling point + + + align:start position:0% +boiling point +compounds three types of distillations + + align:start position:0% +compounds three types of distillations + + + align:start position:0% +compounds three types of distillations +are commonly used in the laboratory + + align:start position:0% +are commonly used in the laboratory + + + align:start position:0% +are commonly used in the laboratory +depending on your liquid solution you + + align:start position:0% +depending on your liquid solution you + + + align:start position:0% +depending on your liquid solution you +will have to decide which type of + + align:start position:0% +will have to decide which type of + + + align:start position:0% +will have to decide which type of +distillation will be the most + + align:start position:0% +distillation will be the most + + + align:start position:0% +distillation will be the most +effective the first type of distillation + + align:start position:0% +effective the first type of distillation + + + align:start position:0% +effective the first type of distillation +is a simple distillation this technique + + align:start position:0% +is a simple distillation this technique + + + align:start position:0% +is a simple distillation this technique +is used when separating missible liquids + + align:start position:0% +is used when separating missible liquids + + + align:start position:0% +is used when separating missible liquids +that boil below 150° C at one atmosphere + + align:start position:0% +that boil below 150° C at one atmosphere + + + align:start position:0% +that boil below 150° C at one atmosphere +from either nonvolatile impurities or + + align:start position:0% +from either nonvolatile impurities or + + + align:start position:0% +from either nonvolatile impurities or +from a second liquid that boils at least + + align:start position:0% +from a second liquid that boils at least + + + align:start position:0% +from a second liquid that boils at least +25° C higher than the first the second + + align:start position:0% +25° C higher than the first the second + + + align:start position:0% +25° C higher than the first the second +type of distillation is the fractional + + align:start position:0% +type of distillation is the fractional + + + align:start position:0% +type of distillation is the fractional +distillation this technique should be + + align:start position:0% +distillation this technique should be + + + align:start position:0% +distillation this technique should be +used to separate liquid mixtures that + + align:start position:0% +used to separate liquid mixtures that + + + align:start position:0% +used to separate liquid mixtures that +have less than a 25° C difference in + + align:start position:0% +have less than a 25° C difference in + + + align:start position:0% +have less than a 25° C difference in +Boiling Point the third type of + + align:start position:0% +Boiling Point the third type of + + + align:start position:0% +Boiling Point the third type of +distillation is a vacuum distillation + + align:start position:0% +distillation is a vacuum distillation + + + align:start position:0% +distillation is a vacuum distillation +this technique should be used to + + align:start position:0% +this technique should be used to + + + align:start position:0% +this technique should be used to +separate missible liquids that boil + + align:start position:0% +separate missible liquids that boil + + + align:start position:0% +separate missible liquids that boil +above 150° cus at one + + align:start position:0% +above 150° cus at one + + + align:start position:0% +above 150° cus at one +atmosphere in this video distillation + + align:start position:0% +atmosphere in this video distillation + + + align:start position:0% +atmosphere in this video distillation +part one we will discuss simple and + + align:start position:0% +part one we will discuss simple and + + + align:start position:0% +part one we will discuss simple and +fractional + + align:start position:0% +fractional + + + align:start position:0% +fractional +distillations in distillation part two + + align:start position:0% +distillations in distillation part two + + + align:start position:0% +distillations in distillation part two +we will discuss vacuum + + align:start position:0% +we will discuss vacuum + + + align:start position:0% +we will discuss vacuum +distillations to carry out a simple + + align:start position:0% +distillations to carry out a simple + + + align:start position:0% +distillations to carry out a simple +distillation you will need a cork ring a + + align:start position:0% +distillation you will need a cork ring a + + + align:start position:0% +distillation you will need a cork ring a +round bottom distilling flask two ring + + align:start position:0% +round bottom distilling flask two ring + + + align:start position:0% +round bottom distilling flask two ring +stands a stir bar and magnetic stirer a + + align:start position:0% +stands a stir bar and magnetic stirer a + + + align:start position:0% +stands a stir bar and magnetic stirer a +distilling head a condenser a vacuum + + align:start position:0% +distilling head a condenser a vacuum + + + align:start position:0% +distilling head a condenser a vacuum +adapter grease three yellow kek clamps a + + align:start position:0% +adapter grease three yellow kek clamps a + + + align:start position:0% +adapter grease three yellow kek clamps a +thermometer and thermometer adapter + + align:start position:0% +thermometer and thermometer adapter + + + align:start position:0% +thermometer and thermometer adapter +three round bottom receiving flasks two + + align:start position:0% +three round bottom receiving flasks two + + + align:start position:0% +three round bottom receiving flasks two +extension clamps and fasteners a heating + + align:start position:0% +extension clamps and fasteners a heating + + + align:start position:0% +extension clamps and fasteners a heating +mantle an iron ring a variable voltage + + align:start position:0% +mantle an iron ring a variable voltage + + + align:start position:0% +mantle an iron ring a variable voltage +Transformer or variac three hose Clips + + align:start position:0% +Transformer or variac three hose Clips + + + align:start position:0% +Transformer or variac three hose Clips +two pieces of rubber tubing and a + + align:start position:0% +two pieces of rubber tubing and a + + + align:start position:0% +two pieces of rubber tubing and a +container for an ice water bath the + + align:start position:0% +container for an ice water bath the + + + align:start position:0% +container for an ice water bath the +first step in performing a distillation + + align:start position:0% +first step in performing a distillation + + + align:start position:0% +first step in performing a distillation +is choosing the proper size distillation + + align:start position:0% +is choosing the proper size distillation + + + align:start position:0% +is choosing the proper size distillation +flask the distilling flask should not be + + align:start position:0% +flask the distilling flask should not be + + + align:start position:0% +flask the distilling flask should not be +more than half full or less than 1/3 + + align:start position:0% +more than half full or less than 1/3 + + + align:start position:0% +more than half full or less than 1/3 +thir full when the distillation begins + + align:start position:0% +thir full when the distillation begins + + + align:start position:0% +thir full when the distillation begins +if the flask is overfilled the solution + + align:start position:0% +if the flask is overfilled the solution + + + align:start position:0% +if the flask is overfilled the solution +will likely overheat or bump into the + + align:start position:0% +will likely overheat or bump into the + + + align:start position:0% +will likely overheat or bump into the +condenser bumping will cause impurities + + align:start position:0% +condenser bumping will cause impurities + + + align:start position:0% +condenser bumping will cause impurities +to be collected in the receiving flask + + align:start position:0% +to be collected in the receiving flask + + + align:start position:0% +to be collected in the receiving flask +rendering the distillation worthless if + + align:start position:0% +rendering the distillation worthless if + + + align:start position:0% +rendering the distillation worthless if +the flask is less than a third full then + + align:start position:0% +the flask is less than a third full then + + + align:start position:0% +the flask is less than a third full then +you'll have a greater chance of losing + + align:start position:0% +you'll have a greater chance of losing + + + align:start position:0% +you'll have a greater chance of losing +some product because a substantial + + align:start position:0% +some product because a substantial + + + align:start position:0% +some product because a substantial +amount of the material will be needed + + align:start position:0% +amount of the material will be needed + + + align:start position:0% +amount of the material will be needed +just to fill the flask and Distilling + + align:start position:0% +just to fill the flask and Distilling + + + align:start position:0% +just to fill the flask and Distilling +head with Vapor while we're on the topic + + align:start position:0% +head with Vapor while we're on the topic + + + align:start position:0% +head with Vapor while we're on the topic +of size we'd like to speak briefly about + + align:start position:0% +of size we'd like to speak briefly about + + + align:start position:0% +of size we'd like to speak briefly about +heating mantel + + align:start position:0% +heating mantel + + + align:start position:0% +heating mantel +if you do not have an appropriately + + align:start position:0% +if you do not have an appropriately + + + align:start position:0% +if you do not have an appropriately +sized heating mantle then use one that + + align:start position:0% +sized heating mantle then use one that + + + align:start position:0% +sized heating mantle then use one that +is too big never use a heating mantle + + align:start position:0% +is too big never use a heating mantle + + + align:start position:0% +is too big never use a heating mantle +that is too small because heat is not + + align:start position:0% +that is too small because heat is not + + + align:start position:0% +that is too small because heat is not +easily transferred between the mantle + + align:start position:0% +easily transferred between the mantle + + + align:start position:0% +easily transferred between the mantle +and flask due to poor contact which + + align:start position:0% +and flask due to poor contact which + + + align:start position:0% +and flask due to poor contact which +causes the mantle to burn out if the + + align:start position:0% +causes the mantle to burn out if the + + + align:start position:0% +causes the mantle to burn out if the +mantle is too big for the flask then add + + align:start position:0% +mantle is too big for the flask then add + + + align:start position:0% +mantle is too big for the flask then add +sand to fill in the empty space after + + align:start position:0% +sand to fill in the empty space after + + + align:start position:0% +sand to fill in the empty space after +you have chosen a distilling flask + + align:start position:0% +you have chosen a distilling flask + + + align:start position:0% +you have chosen a distilling flask +transfer your sample into it and add an + + align:start position:0% +transfer your sample into it and add an + + + align:start position:0% +transfer your sample into it and add an +appropriately sized stir bar bar if you + + align:start position:0% +appropriately sized stir bar bar if you + + + align:start position:0% +appropriately sized stir bar bar if you +will not have access to a magnetic + + align:start position:0% +will not have access to a magnetic + + + align:start position:0% +will not have access to a magnetic +stirer then add a few boiling stones to + + align:start position:0% +stirer then add a few boiling stones to + + + align:start position:0% +stirer then add a few boiling stones to +the distilling flask instead the next + + align:start position:0% +the distilling flask instead the next + + + align:start position:0% +the distilling flask instead the next +step is the Assembly of the distillation + + align:start position:0% +step is the Assembly of the distillation + + + align:start position:0% +step is the Assembly of the distillation +apparatus which is likely one of the + + align:start position:0% +apparatus which is likely one of the + + + align:start position:0% +apparatus which is likely one of the +most difficult glassware subl you'll + + align:start position:0% +most difficult glassware subl you'll + + + align:start position:0% +most difficult glassware subl you'll +ever encounter the neck of the + + align:start position:0% +ever encounter the neck of the + + + align:start position:0% +ever encounter the neck of the +distilling flask is clamped onto one of + + align:start position:0% +distilling flask is clamped onto one of + + + align:start position:0% +distilling flask is clamped onto one of +the Ring stands with an extension clamp + + align:start position:0% +the Ring stands with an extension clamp + + + align:start position:0% +the Ring stands with an extension clamp +and Fastener a heating mantle which is + + align:start position:0% +and Fastener a heating mantle which is + + + align:start position:0% +and Fastener a heating mantle which is +plugged into the variac rests on an iron + + align:start position:0% +plugged into the variac rests on an iron + + + align:start position:0% +plugged into the variac rests on an iron +ring below the distilling flask if + + align:start position:0% +ring below the distilling flask if + + + align:start position:0% +ring below the distilling flask if +you're using a stir bar then place a + + align:start position:0% +you're using a stir bar then place a + + + align:start position:0% +you're using a stir bar then place a +magnetic stirer underneath the heating + + align:start position:0% +magnetic stirer underneath the heating + + + align:start position:0% +magnetic stirer underneath the heating +mantle leave enough room below below the + + align:start position:0% +mantle leave enough room below below the + + + align:start position:0% +mantle leave enough room below below the +iron ring so that the heating mantle can + + align:start position:0% +iron ring so that the heating mantle can + + + align:start position:0% +iron ring so that the heating mantle can +be dropped away from the distilling + + align:start position:0% +be dropped away from the distilling + + + align:start position:0% +be dropped away from the distilling +flask if necessary the distilling head + + align:start position:0% +flask if necessary the distilling head + + + align:start position:0% +flask if necessary the distilling head +is attached to the top of the distilling + + align:start position:0% +is attached to the top of the distilling + + + align:start position:0% +is attached to the top of the distilling +flask and a condenser is attached to the + + align:start position:0% +flask and a condenser is attached to the + + + align:start position:0% +flask and a condenser is attached to the +sidearm of the distilling head the + + align:start position:0% +sidearm of the distilling head the + + + align:start position:0% +sidearm of the distilling head the +vacuum adapter is attached to the other + + align:start position:0% +vacuum adapter is attached to the other + + + align:start position:0% +vacuum adapter is attached to the other +end of the condenser and this joint is + + align:start position:0% +end of the condenser and this joint is + + + align:start position:0% +end of the condenser and this joint is +attached to the second ringstand with an + + align:start position:0% +attached to the second ringstand with an + + + align:start position:0% +attached to the second ringstand with an +extension clamp and Fastener a small + + align:start position:0% +extension clamp and Fastener a small + + + align:start position:0% +extension clamp and Fastener a small +receiving flask is clamped to the vacuum + + align:start position:0% +receiving flask is clamped to the vacuum + + + align:start position:0% +receiving flask is clamped to the vacuum +adapter with a yellow cat clamp and an + + align:start position:0% +adapter with a yellow cat clamp and an + + + align:start position:0% +adapter with a yellow cat clamp and an +ice waterer bath is placed underneath + + align:start position:0% +ice waterer bath is placed underneath + + + align:start position:0% +ice waterer bath is placed underneath +the thermometer and thermometer adapter + + align:start position:0% +the thermometer and thermometer adapter + + + align:start position:0% +the thermometer and thermometer adapter +are attached to the top of the + + align:start position:0% +are attached to the top of the + + + align:start position:0% +are attached to the top of the +distilling head and clamped in place + + align:start position:0% +distilling head and clamped in place + + + align:start position:0% +distilling head and clamped in place +with a green C clamp the top of the + + align:start position:0% +with a green C clamp the top of the + + + align:start position:0% +with a green C clamp the top of the +thermometer bulb should be aligned with + + align:start position:0% +thermometer bulb should be aligned with + + + align:start position:0% +thermometer bulb should be aligned with +the bottom of the sidearm on the + + align:start position:0% +the bottom of the sidearm on the + + + align:start position:0% +the bottom of the sidearm on the +distillation head yellow cat clamps are + + align:start position:0% +distillation head yellow cat clamps are + + + align:start position:0% +distillation head yellow cat clamps are +used to secure both ends of the + + align:start position:0% +used to secure both ends of the + + + align:start position:0% +used to secure both ends of the +condenser rubber tubing is attached to + + align:start position:0% +condenser rubber tubing is attached to + + + align:start position:0% +condenser rubber tubing is attached to +the water inlet and Outlet of the + + align:start position:0% +the water inlet and Outlet of the + + + align:start position:0% +the water inlet and Outlet of the +condenser and secured with hose Clips + + align:start position:0% +condenser and secured with hose Clips + + + align:start position:0% +condenser and secured with hose Clips +finally place two clean dry receiving + + align:start position:0% +finally place two clean dry receiving + + + align:start position:0% +finally place two clean dry receiving +flasks near the distillation apparatus + + align:start position:0% +flasks near the distillation apparatus + + + align:start position:0% +flasks near the distillation apparatus +before continuing confirm that all of + + align:start position:0% +before continuing confirm that all of + + + align:start position:0% +before continuing confirm that all of +the joints have been lightly greased and + + align:start position:0% +the joints have been lightly greased and + + + align:start position:0% +the joints have been lightly greased and +that no cut clamps are used on any joint + + align:start position:0% +that no cut clamps are used on any joint + + + align:start position:0% +that no cut clamps are used on any joint +that will become hot after assembling + + align:start position:0% +that will become hot after assembling + + + align:start position:0% +that will become hot after assembling +the distillation apparatus attach the + + align:start position:0% +the distillation apparatus attach the + + + align:start position:0% +the distillation apparatus attach the +tubing at the bottom of the condenser to + + align:start position:0% +tubing at the bottom of the condenser to + + + align:start position:0% +tubing at the bottom of the condenser to +the Water Source place the end of the + + align:start position:0% +the Water Source place the end of the + + + align:start position:0% +the Water Source place the end of the +tubing at the top of the condenser into + + align:start position:0% +tubing at the top of the condenser into + + + align:start position:0% +tubing at the top of the condenser into +a sink remember water goes in at the + + align:start position:0% +a sink remember water goes in at the + + + align:start position:0% +a sink remember water goes in at the +bottom and out at the top to discourage + + align:start position:0% +bottom and out at the top to discourage + + + align:start position:0% +bottom and out at the top to discourage +the formation of air bubbles double + + align:start position:0% +the formation of air bubbles double + + + align:start position:0% +the formation of air bubbles double +check that all of the joints are secured + + align:start position:0% +check that all of the joints are secured + + + align:start position:0% +check that all of the joints are secured +with hose clips and start the water flow + + align:start position:0% +with hose clips and start the water flow + + + align:start position:0% +with hose clips and start the water flow +the water should flow at the slowest + + align:start position:0% +the water should flow at the slowest + + + align:start position:0% +the water should flow at the slowest +rate that is necessary to keep the + + align:start position:0% +rate that is necessary to keep the + + + align:start position:0% +rate that is necessary to keep the +condenser cold if the Flor rate is too + + align:start position:0% +condenser cold if the Flor rate is too + + + align:start position:0% +condenser cold if the Flor rate is too +fast the chance of the tubing popping + + align:start position:0% +fast the chance of the tubing popping + + + align:start position:0% +fast the chance of the tubing popping +off the condenser and spraying all over + + align:start position:0% +off the condenser and spraying all over + + + align:start position:0% +off the condenser and spraying all over +your workspace greatly increases to + + align:start position:0% +your workspace greatly increases to + + + align:start position:0% +your workspace greatly increases to +perform the simple distillation turn on + + align:start position:0% +perform the simple distillation turn on + + + align:start position:0% +perform the simple distillation turn on +the variac and heat the sample to a + + align:start position:0% +the variac and heat the sample to a + + + align:start position:0% +the variac and heat the sample to a +gentle boil make sure that the vacuum + + align:start position:0% +gentle boil make sure that the vacuum + + + align:start position:0% +gentle boil make sure that the vacuum +adapter remains open to the air never + + align:start position:0% +adapter remains open to the air never + + + align:start position:0% +adapter remains open to the air never +heat to close system or it will explode + + align:start position:0% +heat to close system or it will explode + + + align:start position:0% +heat to close system or it will explode +a ring of condensate will move up the + + align:start position:0% +a ring of condensate will move up the + + + align:start position:0% +a ring of condensate will move up the +flask and into the distilling head when + + align:start position:0% +flask and into the distilling head when + + + align:start position:0% +flask and into the distilling head when +the vapor reaches the height of the + + align:start position:0% +the vapor reaches the height of the + + + align:start position:0% +the vapor reaches the height of the +thermometer bulb the temperature reading + + align:start position:0% +thermometer bulb the temperature reading + + + align:start position:0% +thermometer bulb the temperature reading +will jump dramatically indicating the + + align:start position:0% +will jump dramatically indicating the + + + align:start position:0% +will jump dramatically indicating the +formation of a droplet of liquid on the + + align:start position:0% +formation of a droplet of liquid on the + + + align:start position:0% +formation of a droplet of liquid on the +thermometer bulb if the condensate ring + + align:start position:0% +thermometer bulb if the condensate ring + + + align:start position:0% +thermometer bulb if the condensate ring +completely stops rising at any point + + align:start position:0% +completely stops rising at any point + + + align:start position:0% +completely stops rising at any point +slightly increase the setting on the + + align:start position:0% +slightly increase the setting on the + + + align:start position:0% +slightly increase the setting on the +variac after the vapor reaches the + + align:start position:0% +variac after the vapor reaches the + + + align:start position:0% +variac after the vapor reaches the +condenser it transforms back into liquid + + align:start position:0% +condenser it transforms back into liquid + + + align:start position:0% +condenser it transforms back into liquid +flows down the condenser and into a + + align:start position:0% +flows down the condenser and into a + + + align:start position:0% +flows down the condenser and into a +small receiving flask when approximately + + align:start position:0% +small receiving flask when approximately + + + align:start position:0% +small receiving flask when approximately +10 drops have been collected in the + + align:start position:0% +10 drops have been collected in the + + + align:start position:0% +10 drops have been collected in the +small receiving flask quickly replace it + + align:start position:0% +small receiving flask quickly replace it + + + align:start position:0% +small receiving flask quickly replace it +with the larger one the first couple of + + align:start position:0% +with the larger one the first couple of + + + align:start position:0% +with the larger one the first couple of +drops of a distillation are always + + align:start position:0% +drops of a distillation are always + + + align:start position:0% +drops of a distillation are always +discarded because they may contain some + + align:start position:0% +discarded because they may contain some + + + align:start position:0% +discarded because they may contain some +lower boiling impurities at this point + + align:start position:0% +lower boiling impurities at this point + + + align:start position:0% +lower boiling impurities at this point +the distillate should be dropping into + + align:start position:0% +the distillate should be dropping into + + + align:start position:0% +the distillate should be dropping into +the receiving flask at a rate of 10 + + align:start position:0% +the receiving flask at a rate of 10 + + + align:start position:0% +the receiving flask at a rate of 10 +drops per minute if the rate is faster + + align:start position:0% +drops per minute if the rate is faster + + + align:start position:0% +drops per minute if the rate is faster +then the heat is too high and higher + + align:start position:0% +then the heat is too high and higher + + + align:start position:0% +then the heat is too high and higher +boiling point impurities may have + + align:start position:0% +boiling point impurities may have + + + align:start position:0% +boiling point impurities may have +escaped into the receiving flask if the + + align:start position:0% +escaped into the receiving flask if the + + + align:start position:0% +escaped into the receiving flask if the +rate is too slow then the distillation + + align:start position:0% +rate is too slow then the distillation + + + align:start position:0% +rate is too slow then the distillation +will occur over too long of a time + + align:start position:0% +will occur over too long of a time + + + align:start position:0% +will occur over too long of a time +period after the lower boiling liquid + + align:start position:0% +period after the lower boiling liquid + + + align:start position:0% +period after the lower boiling liquid +has been completely distilled no drop of + + align:start position:0% +has been completely distilled no drop of + + + align:start position:0% +has been completely distilled no drop of +liquid will be on the thermometer bulb + + align:start position:0% +liquid will be on the thermometer bulb + + + align:start position:0% +liquid will be on the thermometer bulb +and the temperature will plunge + + align:start position:0% +and the temperature will plunge + + + align:start position:0% +and the temperature will plunge +dramatically at this point immediately + + align:start position:0% +dramatically at this point immediately + + + align:start position:0% +dramatically at this point immediately +Ely replace the large receiving flask + + align:start position:0% +Ely replace the large receiving flask + + + align:start position:0% +Ely replace the large receiving flask +with a new small receiving flask to + + align:start position:0% +with a new small receiving flask to + + + align:start position:0% +with a new small receiving flask to +collect the last few drops of liquid + + align:start position:0% +collect the last few drops of liquid + + + align:start position:0% +collect the last few drops of liquid +these drops may contain some higher + + align:start position:0% +these drops may contain some higher + + + align:start position:0% +these drops may contain some higher +boiling impurities that should not be + + align:start position:0% +boiling impurities that should not be + + + align:start position:0% +boiling impurities that should not be +collected in the main receiving flask + + align:start position:0% +collected in the main receiving flask + + + align:start position:0% +collected in the main receiving flask +record the temperature range of when the + + align:start position:0% +record the temperature range of when the + + + align:start position:0% +record the temperature range of when the +mixture first started to boil until + + align:start position:0% +mixture first started to boil until + + + align:start position:0% +mixture first started to boil until +right before the dramatic drop in + + align:start position:0% +right before the dramatic drop in + + + align:start position:0% +right before the dramatic drop in +temperature this is the boiling point of + + align:start position:0% +temperature this is the boiling point of + + + align:start position:0% +temperature this is the boiling point of +the distillate if the range is within 2° + + align:start position:0% +the distillate if the range is within 2° + + + align:start position:0% +the distillate if the range is within 2° +C your distillate is fairly pure after + + align:start position:0% +C your distillate is fairly pure after + + + align:start position:0% +C your distillate is fairly pure after +you have collected the final few drops + + align:start position:0% +you have collected the final few drops + + + align:start position:0% +you have collected the final few drops +of liquid turn off the heat Source a + + align:start position:0% +of liquid turn off the heat Source a + + + align:start position:0% +of liquid turn off the heat Source a +simple distillation is performed more + + align:start position:0% +simple distillation is performed more + + + align:start position:0% +simple distillation is performed more +effectively if certain guidelines are + + align:start position:0% +effectively if certain guidelines are + + + align:start position:0% +effectively if certain guidelines are +followed first make sure all the joints + + align:start position:0% +followed first make sure all the joints + + + align:start position:0% +followed first make sure all the joints +on the apparatus are tight and that the + + align:start position:0% +on the apparatus are tight and that the + + + align:start position:0% +on the apparatus are tight and that the +water lines are secured second fill the + + align:start position:0% +water lines are secured second fill the + + + align:start position:0% +water lines are secured second fill the +distilling flask between 1/3 and 1/2 + + align:start position:0% +distilling flask between 1/3 and 1/2 + + + align:start position:0% +distilling flask between 1/3 and 1/2 +full prior to distillation third allow + + align:start position:0% +full prior to distillation third allow + + + align:start position:0% +full prior to distillation third allow +the distillation to proceed at a rate of + + align:start position:0% +the distillation to proceed at a rate of + + + align:start position:0% +the distillation to proceed at a rate of +10 drops per minute fourth use separate + + align:start position:0% +10 drops per minute fourth use separate + + + align:start position:0% +10 drops per minute fourth use separate +receiving flasks for the beginning + + align:start position:0% +receiving flasks for the beginning + + + align:start position:0% +receiving flasks for the beginning +middle and end of the distillation to + + align:start position:0% +middle and end of the distillation to + + + align:start position:0% +middle and end of the distillation to +disallow low and high boiling impurities + + align:start position:0% +disallow low and high boiling impurities + + + align:start position:0% +disallow low and high boiling impurities +into the distillate fifth never let the + + align:start position:0% +into the distillate fifth never let the + + + align:start position:0% +into the distillate fifth never let the +distillation flask run dry a flask that + + align:start position:0% +distillation flask run dry a flask that + + + align:start position:0% +distillation flask run dry a flask that +is allowed to run dry May overheat and + + align:start position:0% +is allowed to run dry May overheat and + + + align:start position:0% +is allowed to run dry May overheat and +break the second type of distillation + + align:start position:0% +break the second type of distillation + + + align:start position:0% +break the second type of distillation +that we will cover is the fractional + + align:start position:0% +that we will cover is the fractional + + + align:start position:0% +that we will cover is the fractional +distillation this technique should be + + align:start position:0% +distillation this technique should be + + + align:start position:0% +distillation this technique should be +used if you need to separate two liquids + + align:start position:0% +used if you need to separate two liquids + + + align:start position:0% +used if you need to separate two liquids +that have a small difference in boiling + + align:start position:0% +that have a small difference in boiling + + + align:start position:0% +that have a small difference in boiling +point less than 25° C a fractional + + align:start position:0% +point less than 25° C a fractional + + + align:start position:0% +point less than 25° C a fractional +distillation is more effective at + + align:start position:0% +distillation is more effective at + + + align:start position:0% +distillation is more effective at +separating liquids with similar boiling + + align:start position:0% +separating liquids with similar boiling + + + align:start position:0% +separating liquids with similar boiling +points because it utilizes a fr + + align:start position:0% +points because it utilizes a fr + + + align:start position:0% +points because it utilizes a fr +fractionating column a fractionating + + align:start position:0% +fractionating column a fractionating + + + align:start position:0% +fractionating column a fractionating +column contains column packing with a + + align:start position:0% +column contains column packing with a + + + align:start position:0% +column contains column packing with a +large surface area and works by + + align:start position:0% +large surface area and works by + + + align:start position:0% +large surface area and works by +promoting a lot of tiny distillations on + + align:start position:0% +promoting a lot of tiny distillations on + + + align:start position:0% +promoting a lot of tiny distillations on +the surface of this packing specifically + + align:start position:0% +the surface of this packing specifically + + + align:start position:0% +the surface of this packing specifically +when the liquid mixture is heated to + + align:start position:0% +when the liquid mixture is heated to + + + align:start position:0% +when the liquid mixture is heated to +Boiling the resulting vapor is richer in + + align:start position:0% +Boiling the resulting vapor is richer in + + + align:start position:0% +Boiling the resulting vapor is richer in +the lower boiling component The Vapor + + align:start position:0% +the lower boiling component The Vapor + + + align:start position:0% +the lower boiling component The Vapor +moves out of the flask and condenses on + + align:start position:0% +moves out of the flask and condenses on + + + align:start position:0% +moves out of the flask and condenses on +the bottom few cenm of the fractionating + + align:start position:0% +the bottom few cenm of the fractionating + + + align:start position:0% +the bottom few cenm of the fractionating +column now the condensed droplet is + + align:start position:0% +column now the condensed droplet is + + + align:start position:0% +column now the condensed droplet is +richer in lower boiling component and + + align:start position:0% +richer in lower boiling component and + + + align:start position:0% +richer in lower boiling component and +the liquid in the distilling flask is + + align:start position:0% +the liquid in the distilling flask is + + + align:start position:0% +the liquid in the distilling flask is +richer in the higher boiling component + + align:start position:0% +richer in the higher boiling component + + + align:start position:0% +richer in the higher boiling component +if that liquid droplet is reheated it + + align:start position:0% +if that liquid droplet is reheated it + + + align:start position:0% +if that liquid droplet is reheated it +will vaporize and condense a little + + align:start position:0% +will vaporize and condense a little + + + align:start position:0% +will vaporize and condense a little +further up the fractionating column this + + align:start position:0% +further up the fractionating column this + + + align:start position:0% +further up the fractionating column this +distillate will have an even higher + + align:start position:0% +distillate will have an even higher + + + align:start position:0% +distillate will have an even higher +percentage of the lower boiling + + align:start position:0% +percentage of the lower boiling + + + align:start position:0% +percentage of the lower boiling +component this process is repeated until + + align:start position:0% +component this process is repeated until + + + align:start position:0% +component this process is repeated until +the vapor reaches the top of the + + align:start position:0% +the vapor reaches the top of the + + + align:start position:0% +the vapor reaches the top of the +fractionating column where theoretically + + align:start position:0% +fractionating column where theoretically + + + align:start position:0% +fractionating column where theoretically +it should be pure in lower boiling + + align:start position:0% +it should be pure in lower boiling + + + align:start position:0% +it should be pure in lower boiling +component to assemble the apparatus for + + align:start position:0% +component to assemble the apparatus for + + + align:start position:0% +component to assemble the apparatus for +a fractional distillation place a + + align:start position:0% +a fractional distillation place a + + + align:start position:0% +a fractional distillation place a +fractionating column between the + + align:start position:0% +fractionating column between the + + + align:start position:0% +fractionating column between the +distillation flask and the distillation + + align:start position:0% +distillation flask and the distillation + + + align:start position:0% +distillation flask and the distillation +head alternatively your lab may have + + align:start position:0% +head alternatively your lab may have + + + align:start position:0% +head alternatively your lab may have +all-in-one distillation glassware that + + align:start position:0% +all-in-one distillation glassware that + + + align:start position:0% +all-in-one distillation glassware that +contains a fractionating column perform + + align:start position:0% +contains a fractionating column perform + + + align:start position:0% +contains a fractionating column perform +the fractional distillation in the same + + align:start position:0% +the fractional distillation in the same + + + align:start position:0% +the fractional distillation in the same +manner as the simple distillation to + + align:start position:0% +manner as the simple distillation to + + + align:start position:0% +manner as the simple distillation to +ensure an effective fractional + + align:start position:0% +ensure an effective fractional + + + align:start position:0% +ensure an effective fractional +distillation heat the distilling flask + + align:start position:0% +distillation heat the distilling flask + + + align:start position:0% +distillation heat the distilling flask +very slowly too much heat causes the + + align:start position:0% +very slowly too much heat causes the + + + align:start position:0% +very slowly too much heat causes the +distillation to occur too rapidly + + align:start position:0% +distillation to occur too rapidly + + + align:start position:0% +distillation to occur too rapidly +disallowing the liquid Vapor equilibria + + align:start position:0% +disallowing the liquid Vapor equilibria + + + align:start position:0% +disallowing the liquid Vapor equilibria +on the surface of the fractionating + + align:start position:0% +on the surface of the fractionating + + + align:start position:0% +on the surface of the fractionating +column if too little heat is used then + + align:start position:0% +column if too little heat is used then + + + align:start position:0% +column if too little heat is used then +the column May lose heat faster than it + + align:start position:0% +the column May lose heat faster than it + + + align:start position:0% +the column May lose heat faster than it +can be warmed up by the vapor preventing + + align:start position:0% +can be warmed up by the vapor preventing + + + align:start position:0% +can be warmed up by the vapor preventing +the vapor from reaching the top of the + + align:start position:0% +the vapor from reaching the top of the + + + align:start position:0% +the vapor from reaching the top of the +column if the column seems to be losing + + align:start position:0% +column if the column seems to be losing + + + align:start position:0% +column if the column seems to be losing +heat faster than it can be warmed up by + + align:start position:0% +heat faster than it can be warmed up by + + + align:start position:0% +heat faster than it can be warmed up by +the vapor you may insulate the column by + + align:start position:0% +the vapor you may insulate the column by + + + align:start position:0% +the vapor you may insulate the column by +wrapping it with glass wool or cotton + + align:start position:0% +wrapping it with glass wool or cotton + + + align:start position:0% +wrapping it with glass wool or cotton +and aluminum foil as a general rule a + + align:start position:0% +and aluminum foil as a general rule a + + + align:start position:0% +and aluminum foil as a general rule a +slow steady distillation where one drop + + align:start position:0% +slow steady distillation where one drop + + + align:start position:0% +slow steady distillation where one drop +is collected every 2 to 3 seconds is + + align:start position:0% +is collected every 2 to 3 seconds is + + + align:start position:0% +is collected every 2 to 3 seconds is +reasonable distillation is an effective + + align:start position:0% +reasonable distillation is an effective + + + align:start position:0% +reasonable distillation is an effective +technique for separating and purifying + + align:start position:0% +technique for separating and purifying + + + align:start position:0% +technique for separating and purifying +liquids when used correctly pure + + align:start position:0% +liquids when used correctly pure + + + align:start position:0% +liquids when used correctly pure +compounds and good yields are readily + + align:start position:0% +compounds and good yields are readily + + + align:start position:0% +compounds and good yields are readily +attained + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/GuiIyYbI0HM.txt b/GuiIyYbI0HM.txt new file mode 100644 index 0000000000000000000000000000000000000000..b7da897541d1e6b735ae9470585ea4b7769b787d --- /dev/null +++ b/GuiIyYbI0HM.txt @@ -0,0 +1,539 @@ +align:start position:0% + +when we did our analytic analysis of the + + align:start position:0% +when we did our analytic analysis of the + + + align:start position:0% +when we did our analytic analysis of the +constraint conditions between the + + align:start position:0% +constraint conditions between the + + + align:start position:0% +constraint conditions between the +accelerations of objects 1 and two we + + align:start position:0% +accelerations of objects 1 and two we + + + align:start position:0% +accelerations of objects 1 and two we +came up with the condition that A1 was + + align:start position:0% +came up with the condition that A1 was + + + align:start position:0% +came up with the condition that A1 was +equal to minus 2 A2 now let's do + + align:start position:0% +equal to minus 2 A2 now let's do + + + align:start position:0% +equal to minus 2 A2 now let's do +something which we call virtual + + align:start position:0% +something which we call virtual + + + align:start position:0% +something which we call virtual +displacement argument suppose that b and + + align:start position:0% +displacement argument suppose that b and + + + align:start position:0% +displacement argument suppose that b and +two move down a certain amount let's + + align:start position:0% +two move down a certain amount let's + + + align:start position:0% +two move down a certain amount let's +imagine and I'm going to draw it in a + + align:start position:0% +imagine and I'm going to draw it in a + + + align:start position:0% +imagine and I'm going to draw it in a +different color two so we have object + + align:start position:0% +different color two so we have object + + + align:start position:0% +different color two so we have object +two and pulley 2 has moved down + + align:start position:0% +two and pulley 2 has moved down + + + align:start position:0% +two and pulley 2 has moved down +now this object has displaced by a + + align:start position:0% +now this object has displaced by a + + + align:start position:0% +now this object has displaced by a +distance Delta Y2 which is also equal to + + align:start position:0% +distance Delta Y2 which is also equal to + + + align:start position:0% +distance Delta Y2 which is also equal to +Delta YB because they're connected now + + align:start position:0% +Delta YB because they're connected now + + + align:start position:0% +Delta YB because they're connected now +what happens when the system does that + + align:start position:0% +what happens when the system does that + + + align:start position:0% +what happens when the system does that +is our rope has to + + align:start position:0% +is our rope has to + + + align:start position:0% +is our rope has to +extend + + align:start position:0% +extend + + + align:start position:0% +extend +downwards around this pulley and come + + align:start position:0% +downwards around this pulley and come + + + align:start position:0% +downwards around this pulley and come +back up and that means that the rope + + align:start position:0% +back up and that means that the rope + + + align:start position:0% +back up and that means that the rope +that object one has been foreshortened + + align:start position:0% +that object one has been foreshortened + + + align:start position:0% +that object one has been foreshortened +by not just Delta y 2 but on both sides + + align:start position:0% +by not just Delta y 2 but on both sides + + + align:start position:0% +by not just Delta y 2 but on both sides +Delta Y2 and Delta Y2 object one has + + align:start position:0% +Delta Y2 and Delta Y2 object one has + + + align:start position:0% +Delta Y2 and Delta Y2 object one has +displaced up by that + + align:start position:0% +displaced up by that + + + align:start position:0% +displaced up by that +amount so we'll + + align:start position:0% +amount so we'll + + + align:start position:0% +amount so we'll +just make this so we can draw it in a + + align:start position:0% +just make this so we can draw it in a + + + align:start position:0% +just make this so we can draw it in a +reasonable way so what we see here is + + align:start position:0% +reasonable way so what we see here is + + + align:start position:0% +reasonable way so what we see here is +that Delta + + align:start position:0% +that Delta + + + align:start position:0% +that Delta +y1 is equal to now notice if two goes + + align:start position:0% +y1 is equal to now notice if two goes + + + align:start position:0% +y1 is equal to now notice if two goes +down + + align:start position:0% +down + + + align:start position:0% +down +y by Delta Y2 then Delta y1 which is + + align:start position:0% +y by Delta Y2 then Delta y1 which is + + + align:start position:0% +y by Delta Y2 then Delta y1 which is +this whole distance is a negative + + align:start position:0% +this whole distance is a negative + + + align:start position:0% +this whole distance is a negative +quantity and it's going upwards and so + + align:start position:0% +quantity and it's going upwards and so + + + align:start position:0% +quantity and it's going upwards and so +we see that that's min-2 Delta + + align:start position:0% +we see that that's min-2 Delta + + + align:start position:0% +we see that that's min-2 Delta +Y2 and if we took two derivatives or + + align:start position:0% +Y2 and if we took two derivatives or + + + align:start position:0% +Y2 and if we took two derivatives or +displacement and then look at the change + + align:start position:0% +displacement and then look at the change + + + align:start position:0% +displacement and then look at the change +in displacement we would see that this + + align:start position:0% +in displacement we would see that this + + + align:start position:0% +in displacement we would see that this +implies that the acceleration of one is + + align:start position:0% +implies that the acceleration of one is + + + align:start position:0% +implies that the acceleration of one is +-2 A2 but let's come back to our two + + align:start position:0% +-2 A2 but let's come back to our two + + + align:start position:0% +-2 A2 but let's come back to our two +conditions for length and see the same + + align:start position:0% +conditions for length and see the same + + + align:start position:0% +conditions for length and see the same +thing here because Delta L2 is + + align:start position:0% +thing here because Delta L2 is + + + align:start position:0% +thing here because Delta L2 is +zero this tells us that Delta Y2 is + + align:start position:0% +zero this tells us that Delta Y2 is + + + align:start position:0% +zero this tells us that Delta Y2 is +equal to Delta YB so we'll write minus + + align:start position:0% +equal to Delta YB so we'll write minus + + + align:start position:0% +equal to Delta YB so we'll write minus +equals z and that was our condition that + + align:start position:0% +equals z and that was our condition that + + + align:start position:0% +equals z and that was our condition that +two the block and two are moving + + align:start position:0% +two the block and two are moving + + + align:start position:0% +two the block and two are moving +together and up here we see that because + + align:start position:0% +together and up here we see that because + + + align:start position:0% +together and up here we see that because +Delta L1 is also + + align:start position:0% +Delta L1 is also + + + align:start position:0% +Delta L1 is also +zero this + + align:start position:0% +zero this + + + align:start position:0% +zero this +implies and now I'll make that + + align:start position:0% +implies and now I'll make that + + + align:start position:0% +implies and now I'll make that +substitution that Delta YB is equal to + + align:start position:0% +substitution that Delta YB is equal to + + + align:start position:0% +substitution that Delta YB is equal to +Delta Y2 that two deltay 2 here and + + align:start position:0% +Delta Y2 that two deltay 2 here and + + + align:start position:0% +Delta Y2 that two deltay 2 here and +here plus Delta y1 has to be zero coming + + align:start position:0% +here plus Delta y1 has to be zero coming + + + align:start position:0% +here plus Delta y1 has to be zero coming +from that piece and so we see that Delta + + align:start position:0% +from that piece and so we see that Delta + + + align:start position:0% +from that piece and so we see that Delta +y1 is minus 2 Delta Y2 which is what our + + align:start position:0% +y1 is minus 2 Delta Y2 which is what our + + + align:start position:0% +y1 is minus 2 Delta Y2 which is what our +virtual displacement argument showed us + + align:start position:0% +virtual displacement argument showed us + + + align:start position:0% +virtual displacement argument showed us +and again if you take two + + align:start position:0% +and again if you take two + + + align:start position:0% +and again if you take two +derivatives here + + align:start position:0% +derivatives here + + + align:start position:0% +derivatives here +we have that recall that in the simplest + + align:start position:0% +we have that recall that in the simplest + + + align:start position:0% +we have that recall that in the simplest +way that the velocity is D y1 + + align:start position:0% +way that the velocity is D y1 + + + align:start position:0% +way that the velocity is D y1 +DT and the + + align:start position:0% +DT and the + + + align:start position:0% +DT and the +acceleration A1 is d^2 y1 DT ^2 then the + + align:start position:0% +acceleration A1 is d^2 y1 DT ^2 then the + + + align:start position:0% +acceleration A1 is d^2 y1 DT ^2 then the +same proportionality is maintained under + + align:start position:0% +same proportionality is maintained under + + + align:start position:0% +same proportionality is maintained under +the two derivatives and that's another + + align:start position:0% +the two derivatives and that's another + + + align:start position:0% +the two derivatives and that's another +way of thinking about how to get the + + align:start position:0% +way of thinking about how to get the + + + align:start position:0% +way of thinking about how to get the +relationship between accelerations but + + align:start position:0% +relationship between accelerations but + + + align:start position:0% +relationship between accelerations but +you have to be extremely careful about + + align:start position:0% +you have to be extremely careful about + + + align:start position:0% +you have to be extremely careful about +that sign because as two goes in the + + align:start position:0% +that sign because as two goes in the + + + align:start position:0% +that sign because as two goes in the +positive direction one will go in the + + align:start position:0% +positive direction one will go in the + + + align:start position:0% +positive direction one will go in the +negative Direction \ No newline at end of file diff --git a/H7xmTMQ265s.txt b/H7xmTMQ265s.txt new file mode 100644 index 0000000000000000000000000000000000000000..11c580d522f7aa88f6773e8218e7201642144856 --- /dev/null +++ b/H7xmTMQ265s.txt @@ -0,0 +1,3491 @@ +align:start position:0% + +if we know the position X of T of an + + align:start position:0% +if we know the position X of T of an + + + align:start position:0% +if we know the position X of T of an +object as a function of time we can use + + align:start position:0% +object as a function of time we can use + + + align:start position:0% +object as a function of time we can use +differentiation to calculate its + + align:start position:0% +differentiation to calculate its + + + align:start position:0% +differentiation to calculate its +velocity and its acceleration at later + + align:start position:0% +velocity and its acceleration at later + + + align:start position:0% +velocity and its acceleration at later +times essentially by taking the + + align:start position:0% +times essentially by taking the + + + align:start position:0% +times essentially by taking the +derivatives of the position we know + + align:start position:0% +derivatives of the position we know + + + align:start position:0% +derivatives of the position we know +everything there is to know about the + + align:start position:0% +everything there is to know about the + + + align:start position:0% +everything there is to know about the +motion sometimes however we'll want to + + align:start position:0% +motion sometimes however we'll want to + + + align:start position:0% +motion sometimes however we'll want to +go in the other direction we'll have the + + align:start position:0% +go in the other direction we'll have the + + + align:start position:0% +go in the other direction we'll have the +acceleration as a function of time and + + align:start position:0% +acceleration as a function of time and + + + align:start position:0% +acceleration as a function of time and +we'll want to find the velocity as a + + align:start position:0% +we'll want to find the velocity as a + + + align:start position:0% +we'll want to find the velocity as a +function of time or the position as a + + align:start position:0% +function of time or the position as a + + + align:start position:0% +function of time or the position as a +function of time we'll use a technique + + align:start position:0% +function of time we'll use a technique + + + align:start position:0% +function of time we'll use a technique +called integration and let's see how + + align:start position:0% +called integration and let's see how + + + align:start position:0% +called integration and let's see how +that + + align:start position:0% +that + + + align:start position:0% +that +works to begin with suppose we have a + + align:start position:0% +works to begin with suppose we have a + + + align:start position:0% +works to begin with suppose we have a +constant + + align:start position:0% + + + + align:start position:0% + +acceleration so our + + align:start position:0% + + + + align:start position:0% + +acceleration a of T is some constant a + + align:start position:0% + + + + align:start position:0% + +not in that case we know that this + + align:start position:0% +not in that case we know that this + + + align:start position:0% +not in that case we know that this +constant acceleration + + align:start position:0% + + + + align:start position:0% + +can be written as the change in velocity + + align:start position:0% +can be written as the change in velocity + + + align:start position:0% +can be written as the change in velocity +Delta V over some time interval delta + + align:start position:0% +Delta V over some time interval delta + + + align:start position:0% +Delta V over some time interval delta +T and therefore that the change in + + align:start position:0% +T and therefore that the change in + + + align:start position:0% +T and therefore that the change in +velocity Delta V over some time interval + + align:start position:0% +velocity Delta V over some time interval + + + align:start position:0% +velocity Delta V over some time interval +delta T can just be written as a KN the + + align:start position:0% +delta T can just be written as a KN the + + + align:start position:0% +delta T can just be written as a KN the +acceleration the constant acceleration + + align:start position:0% +acceleration the constant acceleration + + + align:start position:0% +acceleration the constant acceleration +times the elapsed time delta T and we + + align:start position:0% +times the elapsed time delta T and we + + + align:start position:0% +times the elapsed time delta T and we +can see this graphically if I plot + + align:start position:0% +can see this graphically if I plot + + + align:start position:0% +can see this graphically if I plot +acceleration versus time + + align:start position:0% +acceleration versus time + + + align:start position:0% +acceleration versus time +here's my constant + + align:start position:0% +here's my constant + + + align:start position:0% +here's my constant +acceleration a KN let's say this is time + + align:start position:0% +acceleration a KN let's say this is time + + + align:start position:0% +acceleration a KN let's say this is time +Z and here's the time delta T the change + + align:start position:0% +Z and here's the time delta T the change + + + align:start position:0% +Z and here's the time delta T the change +in velocity a KN time delta T is just + + align:start position:0% +in velocity a KN time delta T is just + + + align:start position:0% +in velocity a KN time delta T is just +the area of this + + align:start position:0% + + + + align:start position:0% + +box that box being defined by the time + + align:start position:0% +box that box being defined by the time + + + align:start position:0% +box that box being defined by the time +interval 0 to delta T and it's the area + + align:start position:0% +interval 0 to delta T and it's the area + + + align:start position:0% +interval 0 to delta T and it's the area +under the curve a kn + + align:start position:0% +under the curve a kn + + + align:start position:0% +under the curve a kn +so if we know the velocity at time zero + + align:start position:0% +so if we know the velocity at time zero + + + align:start position:0% +so if we know the velocity at time zero +and we know the Accel the constant + + align:start position:0% +and we know the Accel the constant + + + align:start position:0% +and we know the Accel the constant +acceleration a we can calculate the + + align:start position:0% +acceleration a we can calculate the + + + align:start position:0% +acceleration a we can calculate the +velocity at any later time in this way + + align:start position:0% +velocity at any later time in this way + + + align:start position:0% +velocity at any later time in this way +because the change in velocity from that + + align:start position:0% +because the change in velocity from that + + + align:start position:0% +because the change in velocity from that +initial velocity is given by a KN time + + align:start position:0% +initial velocity is given by a KN time + + + align:start position:0% +initial velocity is given by a KN time +delta + + align:start position:0% +delta + + + align:start position:0% +delta +T now let's consider a slightly more + + align:start position:0% +T now let's consider a slightly more + + + align:start position:0% +T now let's consider a slightly more +complicated example suppose the + + align:start position:0% +complicated example suppose the + + + align:start position:0% +complicated example suppose the +acceleration isn't constant but is + + align:start position:0% +acceleration isn't constant but is + + + align:start position:0% +acceleration isn't constant but is +changing + + align:start position:0% + + + + align:start position:0% + +linearly so for a linearly changing + + align:start position:0% + + + + align:start position:0% + +acceleration I can draw this + + align:start position:0% +acceleration I can draw this + + + align:start position:0% +acceleration I can draw this +graphically as well here's acceleration + + align:start position:0% +graphically as well here's acceleration + + + align:start position:0% +graphically as well here's acceleration +this is uh time equals zero suppose the + + align:start position:0% +this is uh time equals zero suppose the + + + align:start position:0% +this is uh time equals zero suppose the +acceleration is just + + align:start position:0% +acceleration is just + + + align:start position:0% +acceleration is just +increasing linearly and I'll call this + + align:start position:0% +increasing linearly and I'll call this + + + align:start position:0% +increasing linearly and I'll call this +time delta + + align:start position:0% +time delta + + + align:start position:0% +time delta +T this is a of t + + align:start position:0% +T this is a of t + + + align:start position:0% +T this is a of t +note that we can define an average + + align:start position:0% +note that we can define an average + + + align:start position:0% +note that we can define an average +acceleration over the interval from 0 to + + align:start position:0% +acceleration over the interval from 0 to + + + align:start position:0% +acceleration over the interval from 0 to +delta T the average + + align:start position:0% +delta T the average + + + align:start position:0% +delta T the average +acceleration is the change in + + align:start position:0% + + + + align:start position:0% + +velocity over the elapsed + + align:start position:0% +velocity over the elapsed + + + align:start position:0% +velocity over the elapsed +time that average + + align:start position:0% + + + + align:start position:0% + +acceleration will look something like + + align:start position:0% +acceleration will look something like + + + align:start position:0% +acceleration will look something like +that and so then the change in + + align:start position:0% +that and so then the change in + + + align:start position:0% +that and so then the change in +velocity Delta V is equal to the + + align:start position:0% +velocity Delta V is equal to the + + + align:start position:0% +velocity Delta V is equal to the +average acceleration times the elapsed + + align:start position:0% +average acceleration times the elapsed + + + align:start position:0% +average acceleration times the elapsed +time and this + + align:start position:0% +time and this + + + align:start position:0% +time and this +time notice from the + + align:start position:0% +time notice from the + + + align:start position:0% +time notice from the +diagram this product is actually the + + align:start position:0% +diagram this product is actually the + + + align:start position:0% +diagram this product is actually the +area of this + + align:start position:0% +area of this + + + align:start position:0% +area of this +trapezoid that's basically the area + + align:start position:0% +trapezoid that's basically the area + + + align:start position:0% +trapezoid that's basically the area +under the AF of function going from0 to + + align:start position:0% +under the AF of function going from0 to + + + align:start position:0% +under the AF of function going from0 to +delta T we've calculated it sort of as a + + align:start position:0% +delta T we've calculated it sort of as a + + + align:start position:0% +delta T we've calculated it sort of as a +rectangular area involving the average + + align:start position:0% +rectangular area involving the average + + + align:start position:0% +rectangular area involving the average +acceleration but that's also equal to + + align:start position:0% +acceleration but that's also equal to + + + align:start position:0% +acceleration but that's also equal to +the + + align:start position:0% +the + + + align:start position:0% +the +area under the time + + align:start position:0% +area under the time + + + align:start position:0% +area under the time +changing acceleration + + align:start position:0% +changing acceleration + + + align:start position:0% +changing acceleration +function so this is again the + + align:start position:0% +function so this is again the + + + align:start position:0% +function so this is again the +area + + align:start position:0% +area + + + align:start position:0% +area +under a of T over the time interval + + align:start position:0% +under a of T over the time interval + + + align:start position:0% +under a of T over the time interval +delta + + align:start position:0% + + + + align:start position:0% + +T now let's consider a more generally + + align:start position:0% +T now let's consider a more generally + + + align:start position:0% +T now let's consider a more generally +changing acceleration as a function of + + align:start position:0% +changing acceleration as a function of + + + align:start position:0% +changing acceleration as a function of +time so let me plug B + + align:start position:0% + + + + align:start position:0% + +this so suppose we have just some + + align:start position:0% +this so suppose we have just some + + + align:start position:0% +this so suppose we have just some +general function I'll draw it like this + + align:start position:0% +general function I'll draw it like this + + + align:start position:0% +general function I'll draw it like this +which is our + + align:start position:0% +which is our + + + align:start position:0% +which is our +acceleration as a function of time the + + align:start position:0% +acceleration as a function of time the + + + align:start position:0% +acceleration as a function of time the +change in velocity will still be the + + align:start position:0% +change in velocity will still be the + + + align:start position:0% +change in velocity will still be the +area under the curve AF of T over the + + align:start position:0% +area under the curve AF of T over the + + + align:start position:0% +area under the curve AF of T over the +time interval we're interested in so + + align:start position:0% +time interval we're interested in so + + + align:start position:0% +time interval we're interested in so +let's suppose we want to go from this + + align:start position:0% +let's suppose we want to go from this + + + align:start position:0% +let's suppose we want to go from this +time here I'll call it t sub a and + + align:start position:0% +time here I'll call it t sub a and + + + align:start position:0% +time here I'll call it t sub a and +my ending time will be T + + align:start position:0% +my ending time will be T + + + align:start position:0% +my ending time will be T +subb so we're interested in figuring out + + align:start position:0% +subb so we're interested in figuring out + + + align:start position:0% +subb so we're interested in figuring out +what the area under this curve is over + + align:start position:0% +what the area under this curve is over + + + align:start position:0% +what the area under this curve is over +the interval from T sub a to T subb we + + align:start position:0% +the interval from T sub a to T subb we + + + align:start position:0% +the interval from T sub a to T subb we +can estimate this by breaking up the + + align:start position:0% +can estimate this by breaking up the + + + align:start position:0% +can estimate this by breaking up the +interval into a bunch of little + + align:start position:0% +interval into a bunch of little + + + align:start position:0% +interval into a bunch of little +rectangles suppose I break this up into + + align:start position:0% +rectangles suppose I break this up into + + + align:start position:0% +rectangles suppose I break this up into +n rectangles just under this + + align:start position:0% + + + + align:start position:0% + +curve right so this is one two 3 four + + align:start position:0% +curve right so this is one two 3 four + + + align:start position:0% +curve right so this is one two 3 four +Etc up to n and with each one because + + align:start position:0% +Etc up to n and with each one because + + + align:start position:0% +Etc up to n and with each one because +this is a curved graph I can't get the + + align:start position:0% +this is a curved graph I can't get the + + + align:start position:0% +this is a curved graph I can't get the +rectangle to fit + + align:start position:0% +rectangle to fit + + + align:start position:0% +rectangle to fit +exactly so a little bit of it will stick + + align:start position:0% +exactly so a little bit of it will stick + + + align:start position:0% +exactly so a little bit of it will stick +out at the top in each one I'm not going + + align:start position:0% +out at the top in each one I'm not going + + + align:start position:0% +out at the top in each one I'm not going +to go through that for all of these but + + align:start position:0% +to go through that for all of these but + + + align:start position:0% +to go through that for all of these but +you get the idea um I'll fit these + + align:start position:0% +you get the idea um I'll fit these + + + align:start position:0% +you get the idea um I'll fit these +rectangles as well as I can the narrower + + align:start position:0% +rectangles as well as I can the narrower + + + align:start position:0% +rectangles as well as I can the narrower +I make the rectangles the more easily I + + align:start position:0% +I make the rectangles the more easily I + + + align:start position:0% +I make the rectangles the more easily I +can fit them under the curve for each + + align:start position:0% +can fit them under the curve for each + + + align:start position:0% +can fit them under the curve for each +strip for each rectangular strip + + align:start position:0% + + + + align:start position:0% + +let's say from he over box one from here + + align:start position:0% +let's say from he over box one from here + + + align:start position:0% +let's say from he over box one from here +to here the change in + + align:start position:0% + + + + align:start position:0% + +velocity is equal to the average + + align:start position:0% +velocity is equal to the average + + + align:start position:0% +velocity is equal to the average +velocity over that time + + align:start position:0% +velocity over that time + + + align:start position:0% +velocity over that time +interval times the width of that + + align:start position:0% +interval times the width of that + + + align:start position:0% +interval times the width of that +rectangle delta T so that's the + + align:start position:0% + + + + align:start position:0% + +area of the strip essentially what we're + + align:start position:0% +area of the strip essentially what we're + + + align:start position:0% +area of the strip essentially what we're +saying is that if we make the rectangles + + align:start position:0% +saying is that if we make the rectangles + + + align:start position:0% +saying is that if we make the rectangles +narrow enough we can treat the + + align:start position:0% +narrow enough we can treat the + + + align:start position:0% +narrow enough we can treat the +acceleration the curve of the + + align:start position:0% +acceleration the curve of the + + + align:start position:0% +acceleration the curve of the +acceleration as roughly constant over + + align:start position:0% +acceleration as roughly constant over + + + align:start position:0% +acceleration as roughly constant over +that interval okay and we can make n as + + align:start position:0% +that interval okay and we can make n as + + + align:start position:0% +that interval okay and we can make n as +big as we need to to make those + + align:start position:0% +big as we need to to make those + + + align:start position:0% +big as we need to to make those +rectangles very very narrow okay so in + + align:start position:0% +rectangles very very narrow okay so in + + + align:start position:0% +rectangles very very narrow okay so in +that case we can estimate the total + + align:start position:0% +that case we can estimate the total + + + align:start position:0% +that case we can estimate the total +change in velocity from time T sub a to + + align:start position:0% +change in velocity from time T sub a to + + + align:start position:0% +change in velocity from time T sub a to +time T subb by adding up the area of all + + align:start position:0% +time T subb by adding up the area of all + + + align:start position:0% +time T subb by adding up the area of all +of these rectangular strips okay so in + + align:start position:0% +of these rectangular strips okay so in + + + align:start position:0% +of these rectangular strips okay so in +that case we write that the change in + + align:start position:0% +that case we write that the change in + + + align:start position:0% +that case we write that the change in +Vel vity so I'll say V subb minus V sub + + align:start position:0% +Vel vity so I'll say V subb minus V sub + + + align:start position:0% +Vel vity so I'll say V subb minus V sub +a that's the change in velocity going + + align:start position:0% +a that's the change in velocity going + + + align:start position:0% +a that's the change in velocity going +from time a to time + + align:start position:0% +from time a to time + + + align:start position:0% +from time a to time +B is equal to the + + align:start position:0% +B is equal to the + + + align:start position:0% +B is equal to the +sum as J goes from 1 to + + align:start position:0% +sum as J goes from 1 to + + + align:start position:0% +sum as J goes from 1 to +n of the area of each of these strips + + align:start position:0% +n of the area of each of these strips + + + align:start position:0% +n of the area of each of these strips +and so we want the acceleration at the I + + align:start position:0% +and so we want the acceleration at the I + + + align:start position:0% +and so we want the acceleration at the I +rectangle so that's a of T + + align:start position:0% +rectangle so that's a of T + + + align:start position:0% +rectangle so that's a of T +subj times the width of the strip which + + align:start position:0% +subj times the width of the strip which + + + align:start position:0% +subj times the width of the strip which +each strip has the same width we'll just + + align:start position:0% +each strip has the same width we'll just + + + align:start position:0% +each strip has the same width we'll just +call that delta T and that's the + + align:start position:0% + + + + align:start position:0% + +area of n strips now for a finite I + + align:start position:0% +area of n strips now for a finite I + + + align:start position:0% +area of n strips now for a finite I +really should write this as + + align:start position:0% +really should write this as + + + align:start position:0% +really should write this as +approximately equal to because for a + + align:start position:0% +approximately equal to because for a + + + align:start position:0% +approximately equal to because for a +finite number of rectangular strips this + + align:start position:0% +finite number of rectangular strips this + + + align:start position:0% +finite number of rectangular strips this +is just an approximation because as I + + align:start position:0% +is just an approximation because as I + + + align:start position:0% +is just an approximation because as I +mentioned the rectangles don't exactly + + align:start position:0% +mentioned the rectangles don't exactly + + + align:start position:0% +mentioned the rectangles don't exactly +fit Under The Curve they can't because + + align:start position:0% +fit Under The Curve they can't because + + + align:start position:0% +fit Under The Curve they can't because +the rectangle doesn't have a curved top + + align:start position:0% +the rectangle doesn't have a curved top + + + align:start position:0% +the rectangle doesn't have a curved top +but the function is curved but the + + align:start position:0% +but the function is curved but the + + + align:start position:0% +but the function is curved but the +narrower I make the rectangles or + + align:start position:0% +narrower I make the rectangles or + + + align:start position:0% +narrower I make the rectangles or +equivalently the larger I make + + align:start position:0% +equivalently the larger I make + + + align:start position:0% +equivalently the larger I make +n the better the approximation will be + + align:start position:0% +n the better the approximation will be + + + align:start position:0% +n the better the approximation will be +so what what I want to do is go to the + + align:start position:0% +so what what I want to do is go to the + + + align:start position:0% +so what what I want to do is go to the +limit of an infinite number of + + align:start position:0% +limit of an infinite number of + + + align:start position:0% +limit of an infinite number of +rectangles or equivalently the limit of + + align:start position:0% +rectangles or equivalently the limit of + + + align:start position:0% +rectangles or equivalently the limit of +infinitesimally narrow strips I want + + align:start position:0% +infinitesimally narrow strips I want + + + align:start position:0% +infinitesimally narrow strips I want +delta T to go to zero so to make this + + align:start position:0% +delta T to go to zero so to make this + + + align:start position:0% +delta T to go to zero so to make this +exact what I would write is + + align:start position:0% +exact what I would write is + + + align:start position:0% +exact what I would write is +that the change in velocity from time a + + align:start position:0% +that the change in velocity from time a + + + align:start position:0% +that the change in velocity from time a +to time B is equal to the + + align:start position:0% + + + + align:start position:0% + +limit of the sum from J = 1 to n of the + + align:start position:0% +limit of the sum from J = 1 to n of the + + + align:start position:0% +limit of the sum from J = 1 to n of the +acceleration at time T subj time delta T + + align:start position:0% +acceleration at time T subj time delta T + + + align:start position:0% +acceleration at time T subj time delta T +and we want to evaluate that limit as + + align:start position:0% +and we want to evaluate that limit as + + + align:start position:0% +and we want to evaluate that limit as +delta T goes to zero or equivalently as + + align:start position:0% +delta T goes to zero or equivalently as + + + align:start position:0% +delta T goes to zero or equivalently as +n the number of rectangles goes to + + align:start position:0% +n the number of rectangles goes to + + + align:start position:0% +n the number of rectangles goes to +Infinity okay now this is a very + + align:start position:0% +Infinity okay now this is a very + + + align:start position:0% +Infinity okay now this is a very +important expression + + align:start position:0% +important expression + + + align:start position:0% +important expression +and we have a special way of writing it + + align:start position:0% +and we have a special way of writing it + + + align:start position:0% +and we have a special way of writing it +we can also write it as an integral so + + align:start position:0% +we can also write it as an integral so + + + align:start position:0% +we can also write it as an integral so +we write it as the integral of the + + align:start position:0% +we write it as the integral of the + + + align:start position:0% +we write it as the integral of the +function a of + + align:start position:0% +function a of + + + align:start position:0% +function a of +T DT evaluated + + align:start position:0% +T DT evaluated + + + align:start position:0% +T DT evaluated +from time equals T sub a to time equals + + align:start position:0% +from time equals T sub a to time equals + + + align:start position:0% +from time equals T sub a to time equals +T subb and this + + align:start position:0% + + + + align:start position:0% + +is the area + + align:start position:0% +is the area + + + align:start position:0% +is the area +under the AF oft + + align:start position:0% +under the AF oft + + + align:start position:0% +under the AF oft +curve the exact area not the approximate + + align:start position:0% +curve the exact area not the approximate + + + align:start position:0% +curve the exact area not the approximate +area but the exact area under the AF of + + align:start position:0% +area but the exact area under the AF of + + + align:start position:0% +area but the exact area under the AF of +curve over the interval from T of a to T + + align:start position:0% +curve over the interval from T of a to T + + + align:start position:0% +curve over the interval from T of a to T +of B this limiting + + align:start position:0% +of B this limiting + + + align:start position:0% +of B this limiting +sum that we've written this way on the + + align:start position:0% +sum that we've written this way on the + + + align:start position:0% +sum that we've written this way on the +right hand side is called the definite + + align:start position:0% +right hand side is called the definite + + + align:start position:0% +right hand side is called the definite +integral of a of + + align:start position:0% +integral of a of + + + align:start position:0% +integral of a of +T and it's related + + align:start position:0% +T and it's related + + + align:start position:0% +T and it's related +to the process of integration that + + align:start position:0% +to the process of integration that + + + align:start position:0% +to the process of integration that +you've learned about in calculus which + + align:start position:0% +you've learned about in calculus which + + + align:start position:0% +you've learned about in calculus which +is the in inverse of taking the + + align:start position:0% +is the in inverse of taking the + + + align:start position:0% +is the in inverse of taking the +derivative the inverse of + + align:start position:0% +derivative the inverse of + + + align:start position:0% +derivative the inverse of +differentiation I want to take a moment + + align:start position:0% +differentiation I want to take a moment + + + align:start position:0% +differentiation I want to take a moment +to summarize the basic principles of + + align:start position:0% +to summarize the basic principles of + + + align:start position:0% +to summarize the basic principles of +integration from + + align:start position:0% +integration from + + + align:start position:0% +integration from +calculus let's begin by considering a + + align:start position:0% +calculus let's begin by considering a + + + align:start position:0% +calculus let's begin by considering a +function G ofx with some derivative + + align:start position:0% + + + + align:start position:0% + +so consider a function G ofx and let's + + align:start position:0% +so consider a function G ofx and let's + + + align:start position:0% +so consider a function G ofx and let's +assume it's a well- behaved function by + + align:start position:0% +assume it's a well- behaved function by + + + align:start position:0% +assume it's a well- behaved function by +which I mean that it's continuous and + + align:start position:0% +which I mean that it's continuous and + + + align:start position:0% +which I mean that it's continuous and +differentiable over the interval that + + align:start position:0% +differentiable over the interval that + + + align:start position:0% +differentiable over the interval that +we're interested in so consider gfx + + align:start position:0% + + + + align:start position:0% + +with the derivative so + + align:start position:0% +with the derivative so + + + align:start position:0% +with the derivative so +DG DX equal to another function which + + align:start position:0% +DG DX equal to another function which + + + align:start position:0% +DG DX equal to another function which +I'll call F + + align:start position:0% +I'll call F + + + align:start position:0% +I'll call F +ofx now note that if I add a constant to + + align:start position:0% +ofx now note that if I add a constant to + + + align:start position:0% +ofx now note that if I add a constant to +G ofx I'll still get the same + + align:start position:0% + + + + align:start position:0% + +derivative so note that the derivative + + align:start position:0% +derivative so note that the derivative + + + align:start position:0% +derivative so note that the derivative +with respect to X of G of X Plus + + align:start position:0% + + + + align:start position:0% + +a constant is still equal to the same + + align:start position:0% +a constant is still equal to the same + + + align:start position:0% +a constant is still equal to the same +function f ofx and this is because the + + align:start position:0% +function f ofx and this is because the + + + align:start position:0% +function f ofx and this is because the +derivative of a constant is equal to + + align:start position:0% +derivative of a constant is equal to + + + align:start position:0% +derivative of a constant is equal to +zero now suppose I want to invert this + + align:start position:0% +zero now suppose I want to invert this + + + align:start position:0% +zero now suppose I want to invert this +process then I can write that the + + align:start position:0% +process then I can write that the + + + align:start position:0% +process then I can write that the +anti-derivative of f + + align:start position:0% + + + + align:start position:0% + +ofx the anti-derivative + + align:start position:0% + + + + align:start position:0% + +of f ofx which I'll write as the + + align:start position:0% +of f ofx which I'll write as the + + + align:start position:0% +of f ofx which I'll write as the +integral of f + + align:start position:0% +integral of f + + + align:start position:0% +integral of f +ofx + + align:start position:0% +ofx + + + align:start position:0% +ofx +DX is equal + + align:start position:0% +DX is equal + + + align:start position:0% +DX is equal +to g ofx + + align:start position:0% +to g ofx + + + align:start position:0% +to g ofx +plus a constant okay the left hand side + + align:start position:0% +plus a constant okay the left hand side + + + align:start position:0% +plus a constant okay the left hand side +of this we call an indefinite + + align:start position:0% + + + + align:start position:0% + +integral and so we see that if the + + align:start position:0% +integral and so we see that if the + + + align:start position:0% +integral and so we see that if the +derivative of G ofx is f ofx plus a + + align:start position:0% +derivative of G ofx is f ofx plus a + + + align:start position:0% +derivative of G ofx is f ofx plus a +constant the anti-derivative of f ofx is + + align:start position:0% +constant the anti-derivative of f ofx is + + + align:start position:0% +constant the anti-derivative of f ofx is +G ofx plus a + + align:start position:0% +G ofx plus a + + + align:start position:0% +G ofx plus a +constant and and that can be any + + align:start position:0% +constant and and that can be any + + + align:start position:0% +constant and and that can be any +arbitrary constant now in calculus one + + align:start position:0% +arbitrary constant now in calculus one + + + align:start position:0% +arbitrary constant now in calculus one +learns how to calculate the indefinite + + align:start position:0% +learns how to calculate the indefinite + + + align:start position:0% +learns how to calculate the indefinite +integral of various + + align:start position:0% +integral of various + + + align:start position:0% +integral of various +functions pols trigonometric functions + + align:start position:0% +functions pols trigonometric functions + + + align:start position:0% +functions pols trigonometric functions +logarithmic functions + + align:start position:0% +logarithmic functions + + + align:start position:0% +logarithmic functions +Etc calculus also shows us how to + + align:start position:0% +Etc calculus also shows us how to + + + align:start position:0% +Etc calculus also shows us how to +compute the definite + + align:start position:0% + + + + align:start position:0% + +integral + + align:start position:0% + + + + align:start position:0% + +so the definite + + align:start position:0% +so the definite + + + align:start position:0% +so the definite +integral the integral of + + align:start position:0% +integral the integral of + + + align:start position:0% +integral the integral of +FFX DX evaluated from xal A to xal B so + + align:start position:0% +FFX DX evaluated from xal A to xal B so + + + align:start position:0% +FFX DX evaluated from xal A to xal B so +this is the definite integral computed + + align:start position:0% +this is the definite integral computed + + + align:start position:0% +this is the definite integral computed +over some + + align:start position:0% + + + + align:start position:0% + +interval is equal to + + align:start position:0% +interval is equal to + + + align:start position:0% +interval is equal to +the + + align:start position:0% +the + + + align:start position:0% +the +anti-derivative at X = B minus the + + align:start position:0% +anti-derivative at X = B minus the + + + align:start position:0% +anti-derivative at X = B minus the +anti-derivative evaluated at xal a and + + align:start position:0% +anti-derivative evaluated at xal a and + + + align:start position:0% +anti-derivative evaluated at xal a and +this turns out to + + align:start position:0% +this turns out to + + + align:start position:0% +this turns out to +be the + + align:start position:0% + + + + align:start position:0% + +area under the + + align:start position:0% +area under the + + + align:start position:0% +area under the +curve F + + align:start position:0% +curve F + + + align:start position:0% +curve F +ofx in the + + align:start position:0% + + + + align:start position:0% + +interval between xal a and xal b + + align:start position:0% +interval between xal a and xal b + + + align:start position:0% +interval between xal a and xal b +okay now notice that there's no + + align:start position:0% +okay now notice that there's no + + + align:start position:0% +okay now notice that there's no +arbitrary constant in the definite + + align:start position:0% +arbitrary constant in the definite + + + align:start position:0% +arbitrary constant in the definite +integral in the indefinite integral we + + align:start position:0% +integral in the indefinite integral we + + + align:start position:0% +integral in the indefinite integral we +have an arbitrary constant but in the + + align:start position:0% +have an arbitrary constant but in the + + + align:start position:0% +have an arbitrary constant but in the +definite integral that arbitrary + + align:start position:0% +definite integral that arbitrary + + + align:start position:0% +definite integral that arbitrary +constant is determined by setting the + + align:start position:0% +constant is determined by setting the + + + align:start position:0% +constant is determined by setting the +integration limits okay so there's no + + align:start position:0% +integration limits okay so there's no + + + align:start position:0% +integration limits okay so there's no +arbitrary constant we just have this + + align:start position:0% +arbitrary constant we just have this + + + align:start position:0% +arbitrary constant we just have this +difference okay and so just to see this + + align:start position:0% +difference okay and so just to see this + + + align:start position:0% +difference okay and so just to see this +graphically if I + + align:start position:0% +graphically if I + + + align:start position:0% +graphically if I +plot my function + + align:start position:0% + + + + align:start position:0% + +of X and suppose this is xal + + align:start position:0% +of X and suppose this is xal + + + align:start position:0% +of X and suppose this is xal +a and this is xal B this definite + + align:start position:0% +a and this is xal B this definite + + + align:start position:0% +a and this is xal B this definite +integral represents the + + align:start position:0% + + + + align:start position:0% + +area under the curve F ofx in the + + align:start position:0% +area under the curve F ofx in the + + + align:start position:0% +area under the curve F ofx in the +interval from xal A to xals B so + + align:start position:0% +interval from xal A to xals B so + + + align:start position:0% +interval from xal A to xals B so +calculus tells us how to solve this area + + align:start position:0% +calculus tells us how to solve this area + + + align:start position:0% +calculus tells us how to solve this area +problem how to compute a definite + + align:start position:0% +problem how to compute a definite + + + align:start position:0% +problem how to compute a definite +integral from the anti-derivative that + + align:start position:0% +integral from the anti-derivative that + + + align:start position:0% +integral from the anti-derivative that +you get from indefinite + + align:start position:0% +you get from indefinite + + + align:start position:0% +you get from indefinite +integration and so this same technique + + align:start position:0% +integration and so this same technique + + + align:start position:0% +integration and so this same technique +tells us how to determine uh the + + align:start position:0% +tells us how to determine uh the + + + align:start position:0% +tells us how to determine uh the +velocity from the acceleration since we + + align:start position:0% +velocity from the acceleration since we + + + align:start position:0% +velocity from the acceleration since we +saw that that was equivalent to an area + + align:start position:0% +saw that that was equivalent to an area + + + align:start position:0% +saw that that was equivalent to an area +under the curve + + align:start position:0% +under the curve + + + align:start position:0% +under the curve +problem so to come back to the motion of + + align:start position:0% +problem so to come back to the motion of + + + align:start position:0% +problem so to come back to the motion of +objects we've shown that the change in + + align:start position:0% +objects we've shown that the change in + + + align:start position:0% +objects we've shown that the change in +velocity of an object can be written as + + align:start position:0% +velocity of an object can be written as + + + align:start position:0% +velocity of an object can be written as +the definite integral of the + + align:start position:0% +the definite integral of the + + + align:start position:0% +the definite integral of the +acceleration so uh just to write that a + + align:start position:0% +acceleration so uh just to write that a + + + align:start position:0% +acceleration so uh just to write that a +little bit more formally uh first with a + + align:start position:0% +little bit more formally uh first with a + + + align:start position:0% +little bit more formally uh first with a +plot if this is + + align:start position:0% +plot if this is + + + align:start position:0% +plot if this is +my + + align:start position:0% +my + + + align:start position:0% +my +acceleration as a function of + + align:start position:0% + + + + align:start position:0% + +time we know that the time derivative of + + align:start position:0% +time we know that the time derivative of + + + align:start position:0% +time we know that the time derivative of +the Velocity is equal + + align:start position:0% +the Velocity is equal + + + align:start position:0% +the Velocity is equal +to the acceleration as a function of + + align:start position:0% +to the acceleration as a function of + + + align:start position:0% +to the acceleration as a function of +time I can rewrite that as the + + align:start position:0% +time I can rewrite that as the + + + align:start position:0% +time I can rewrite that as the +differential DV is equal + + align:start position:0% +differential DV is equal + + + align:start position:0% +differential DV is equal +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to a of T times the differential d + + align:start position:0% + + + + align:start position:0% + +T and so then I can integrate both sides + + align:start position:0% +T and so then I can integrate both sides + + + align:start position:0% +T and so then I can integrate both sides +of this + + align:start position:0% +of this + + + align:start position:0% +of this +equation by writing the + + align:start position:0% +equation by writing the + + + align:start position:0% +equation by writing the +integral over DV is equal to the + + align:start position:0% +integral over DV is equal to the + + + align:start position:0% +integral over DV is equal to the +integral of the acceleration AF of + + align:start position:0% +integral of the acceleration AF of + + + align:start position:0% +integral of the acceleration AF of +T + + align:start position:0% +T + + + align:start position:0% +T +DT and I can go from time + + align:start position:0% +DT and I can go from time + + + align:start position:0% +DT and I can go from time +equals some initial time T KN + + align:start position:0% +equals some initial time T KN + + + align:start position:0% +equals some initial time T KN +to time equal to some later time T sub + + align:start position:0% +to time equal to some later time T sub + + + align:start position:0% +to time equal to some later time T sub +one on the right hand side to make a + + align:start position:0% +one on the right hand side to make a + + + align:start position:0% +one on the right hand side to make a +definite integral and then on the left + + align:start position:0% +definite integral and then on the left + + + align:start position:0% +definite integral and then on the left +hand side the corresponding limits are + + align:start position:0% +hand side the corresponding limits are + + + align:start position:0% +hand side the corresponding limits are +the velocity at Time Zero I'll call that + + align:start position:0% +the velocity at Time Zero I'll call that + + + align:start position:0% +the velocity at Time Zero I'll call that +V KN and the velocity at time one which + + align:start position:0% +V KN and the velocity at time one which + + + align:start position:0% +V KN and the velocity at time one which +I'll call V1 so just to be clear I'm + + align:start position:0% +I'll call V1 so just to be clear I'm + + + align:start position:0% +I'll call V1 so just to be clear I'm +assuming here that V KN is equal to the + + align:start position:0% +assuming here that V KN is equal to the + + + align:start position:0% +assuming here that V KN is equal to the +velocity at time T KN and V1 is equal to + + align:start position:0% +velocity at time T KN and V1 is equal to + + + align:start position:0% +velocity at time T KN and V1 is equal to +the velocity at time T sub + + align:start position:0% +the velocity at time T sub + + + align:start position:0% +the velocity at time T sub +1 so this is the integral of a constant + + align:start position:0% +1 so this is the integral of a constant + + + align:start position:0% +1 so this is the integral of a constant +over over an interval of V this is an + + align:start position:0% +over over an interval of V this is an + + + align:start position:0% +over over an interval of V this is an +interval of the acceleration over the + + align:start position:0% +interval of the acceleration over the + + + align:start position:0% +interval of the acceleration over the +time uh time interval in T and so the + + align:start position:0% +time uh time interval in T and so the + + + align:start position:0% +time uh time interval in T and so the +left hand side this is + + align:start position:0% +left hand side this is + + + align:start position:0% +left hand side this is +just V1 minus V KN and the right hand + + align:start position:0% +just V1 minus V KN and the right hand + + + align:start position:0% +just V1 minus V KN and the right hand +side without specifying AF of T I can't + + align:start position:0% +side without specifying AF of T I can't + + + align:start position:0% +side without specifying AF of T I can't +actually evaluate this integral I can't + + align:start position:0% +actually evaluate this integral I can't + + + align:start position:0% +actually evaluate this integral I can't +specify what the anti-derivative of AF + + align:start position:0% +specify what the anti-derivative of AF + + + align:start position:0% +specify what the anti-derivative of AF +of T is unless I tell you what the + + align:start position:0% +of T is unless I tell you what the + + + align:start position:0% +of T is unless I tell you what the +function AF of T is so we'll just have + + align:start position:0% +function AF of T is so we'll just have + + + align:start position:0% +function AF of T is so we'll just have +to leave it in terms of an integral and + + align:start position:0% +to leave it in terms of an integral and + + + align:start position:0% +to leave it in terms of an integral and +so that's just the integral of a of T + + align:start position:0% +so that's just the integral of a of T + + + align:start position:0% +so that's just the integral of a of T +DT from tal T to tal T sub1 so again + + align:start position:0% +DT from tal T to tal T sub1 so again + + + align:start position:0% +DT from tal T to tal T sub1 so again +this shows us that the change in the + + align:start position:0% +this shows us that the change in the + + + align:start position:0% +this shows us that the change in the +velocity from time t 0 to a later time + + align:start position:0% +velocity from time t 0 to a later time + + + align:start position:0% +velocity from time t 0 to a later time +T1 is equal to the definite integral of + + align:start position:0% +T1 is equal to the definite integral of + + + align:start position:0% +T1 is equal to the definite integral of +a of T over that + + align:start position:0% +a of T over that + + + align:start position:0% +a of T over that +interval I can rewrite this uh in terms + + align:start position:0% +interval I can rewrite this uh in terms + + + align:start position:0% +interval I can rewrite this uh in terms +of what the velocity at some later time + + align:start position:0% +of what the velocity at some later time + + + align:start position:0% +of what the velocity at some later time +T1 by writing the velocity + + align:start position:0% +T1 by writing the velocity + + + align:start position:0% +T1 by writing the velocity +at T1 is equal + + align:start position:0% +at T1 is equal + + + align:start position:0% +at T1 is equal +to V plus the integral of a of T DT from + + align:start position:0% +to V plus the integral of a of T DT from + + + align:start position:0% +to V plus the integral of a of T DT from +tal T to + + align:start position:0% +tal T to + + + align:start position:0% +tal T to +tal + + align:start position:0% +tal + + + align:start position:0% +tal +T1 note that T1 is just any later Time + + align:start position:0% +T1 note that T1 is just any later Time + + + align:start position:0% +T1 note that T1 is just any later Time +After Time T KN where we have the + + align:start position:0% +After Time T KN where we have the + + + align:start position:0% +After Time T KN where we have the +initial velocity so a more convenient + + align:start position:0% +initial velocity so a more convenient + + + align:start position:0% +initial velocity so a more convenient +way of writing this function might be to + + align:start position:0% +way of writing this function might be to + + + align:start position:0% +way of writing this function might be to +write the velocity as aun function of + + align:start position:0% +write the velocity as aun function of + + + align:start position:0% +write the velocity as aun function of +some later time + + align:start position:0% +some later time + + + align:start position:0% +some later time +T So suppose I were to do that I'll just + + align:start position:0% +T So suppose I were to do that I'll just + + + align:start position:0% +T So suppose I were to do that I'll just +rewrite this equation replacing T1 with + + align:start position:0% +rewrite this equation replacing T1 with + + + align:start position:0% +rewrite this equation replacing T1 with +an arbitrary time + + align:start position:0% +an arbitrary time + + + align:start position:0% +an arbitrary time +T so I have that V of T is equal to V KN + + align:start position:0% +T so I have that V of T is equal to V KN + + + align:start position:0% +T so I have that V of T is equal to V KN +plus the + + align:start position:0% +plus the + + + align:start position:0% +plus the +integral of a of T + + align:start position:0% +integral of a of T + + + align:start position:0% +integral of a of T +DT from T = + + align:start position:0% +DT from T = + + + align:start position:0% +DT from T = +t0 to t = t now there's something funny + + align:start position:0% +t0 to t = t now there's something funny + + + align:start position:0% +t0 to t = t now there's something funny +here because I have t in the integration + + align:start position:0% +here because I have t in the integration + + + align:start position:0% +here because I have t in the integration +variable here but I have t as one of my + + align:start position:0% +variable here but I have t as one of my + + + align:start position:0% +variable here but I have t as one of my +limits here as well okay whereas if I + + align:start position:0% +limits here as well okay whereas if I + + + align:start position:0% +limits here as well okay whereas if I +look at this expression here there's a + + align:start position:0% +look at this expression here there's a + + + align:start position:0% +look at this expression here there's a +difference between the T in the + + align:start position:0% +difference between the T in the + + + align:start position:0% +difference between the T in the +integration variable and the limit T1 + + align:start position:0% +integration variable and the limit T1 + + + align:start position:0% +integration variable and the limit T1 +they actually represent different things + + align:start position:0% +they actually represent different things + + + align:start position:0% +they actually represent different things +so to keep track of that the notation + + align:start position:0% +so to keep track of that the notation + + + align:start position:0% +so to keep track of that the notation +that we generally use in physics is to + + align:start position:0% +that we generally use in physics is to + + + align:start position:0% +that we generally use in physics is to +call this integration variable T Prime + + align:start position:0% +call this integration variable T Prime + + + align:start position:0% +call this integration variable T Prime +and so we write this acceleration of T + + align:start position:0% +and so we write this acceleration of T + + + align:start position:0% +and so we write this acceleration of T +Prime DT Prime with the time T Prime + + align:start position:0% +Prime DT Prime with the time T Prime + + + align:start position:0% +Prime DT Prime with the time T Prime +going from T KN to some later time T now + + align:start position:0% +going from T KN to some later time T now + + + align:start position:0% +going from T KN to some later time T now +one has to be cautious here in some + + align:start position:0% +one has to be cautious here in some + + + align:start position:0% +one has to be cautious here in some +fields that Prime on a variable is used + + align:start position:0% +fields that Prime on a variable is used + + + align:start position:0% +fields that Prime on a variable is used +to denote a derivative differentiation + + align:start position:0% +to denote a derivative differentiation + + + align:start position:0% +to denote a derivative differentiation +that's not what it means here I'm + + align:start position:0% +that's not what it means here I'm + + + align:start position:0% +that's not what it means here I'm +writing T Prime just to distinguish it + + align:start position:0% +writing T Prime just to distinguish it + + + align:start position:0% +writing T Prime just to distinguish it +from the specific later time T that I + + align:start position:0% +from the specific later time T that I + + + align:start position:0% +from the specific later time T that I +want to calculate the velocity at and + + align:start position:0% +want to calculate the velocity at and + + + align:start position:0% +want to calculate the velocity at and +it's worth thinking about what this + + align:start position:0% +it's worth thinking about what this + + + align:start position:0% +it's worth thinking about what this +expression means this equation is + + align:start position:0% +expression means this equation is + + + align:start position:0% +expression means this equation is +identical to this earli equation that we + + align:start position:0% +identical to this earli equation that we + + + align:start position:0% +identical to this earli equation that we +derived except for a change in notation + + align:start position:0% +derived except for a change in notation + + + align:start position:0% +derived except for a change in notation +and so let's think about what that + + align:start position:0% +and so let's think about what that + + + align:start position:0% +and so let's think about what that +notation means T Prime here is the + + align:start position:0% +notation means T Prime here is the + + + align:start position:0% +notation means T Prime here is the +integration variable it's a placeholder + + align:start position:0% +integration variable it's a placeholder + + + align:start position:0% +integration variable it's a placeholder +remember the integral here the definite + + align:start position:0% +remember the integral here the definite + + + align:start position:0% +remember the integral here the definite +integral represents an infinite sum an + + align:start position:0% +integral represents an infinite sum an + + + align:start position:0% +integral represents an infinite sum an +infinite sum of rectangles + + align:start position:0% +infinite sum of rectangles + + + align:start position:0% +infinite sum of rectangles +between a Time T KN and a later time + + align:start position:0% +between a Time T KN and a later time + + + align:start position:0% +between a Time T KN and a later time +T and that variable T Prime actually + + align:start position:0% +T and that variable T Prime actually + + + align:start position:0% +T and that variable T Prime actually +what I should do now is I should call + + align:start position:0% +what I should do now is I should call + + + align:start position:0% +what I should do now is I should call +this T + + align:start position:0% +this T + + + align:start position:0% +this T +Prime this variable T Prime is taking + + align:start position:0% +Prime this variable T Prime is taking + + + align:start position:0% +Prime this variable T Prime is taking +every value from T KN to T So T Prime is + + align:start position:0% +every value from T KN to T So T Prime is + + + align:start position:0% +every value from T KN to T So T Prime is +representing the running time variable + + align:start position:0% +representing the running time variable + + + align:start position:0% +representing the running time variable +for all of our strips that we're adding + + align:start position:0% +for all of our strips that we're adding + + + align:start position:0% +for all of our strips that we're adding +up over this definite integral okay so + + align:start position:0% +up over this definite integral okay so + + + align:start position:0% +up over this definite integral okay so +it's a placeholder variable we sometimes + + align:start position:0% +it's a placeholder variable we sometimes + + + align:start position:0% +it's a placeholder variable we sometimes +call it a dummy variable it's just a + + align:start position:0% +call it a dummy variable it's just a + + + align:start position:0% +call it a dummy variable it's just a +placeholder to represent time whereas T + + align:start position:0% +placeholder to represent time whereas T + + + align:start position:0% +placeholder to represent time whereas T +the T and the limit here without the + + align:start position:0% +the T and the limit here without the + + + align:start position:0% +the T and the limit here without the +prime represents a specific choice of + + align:start position:0% +prime represents a specific choice of + + + align:start position:0% +prime represents a specific choice of +later time some later time T where we + + align:start position:0% +later time some later time T where we + + + align:start position:0% +later time some later time T where we +want to calculate the velocity so we + + align:start position:0% +want to calculate the velocity so we + + + align:start position:0% +want to calculate the velocity so we +know the velocity at some initial time + + align:start position:0% +know the velocity at some initial time + + + align:start position:0% +know the velocity at some initial time +T we' like to know the velocity at some + + align:start position:0% +T we' like to know the velocity at some + + + align:start position:0% +T we' like to know the velocity at some +specific later time T and to compute + + align:start position:0% +specific later time T and to compute + + + align:start position:0% +specific later time T and to compute +that we have to integrate over all times + + align:start position:0% +that we have to integrate over all times + + + align:start position:0% +that we have to integrate over all times +running from T KN to T and that running + + align:start position:0% +running from T KN to T and that running + + + align:start position:0% +running from T KN to T and that running +integration variable we represent as T + + align:start position:0% +integration variable we represent as T + + + align:start position:0% +integration variable we represent as T +Prime just to distinguish it from the + + align:start position:0% +Prime just to distinguish it from the + + + align:start position:0% +Prime just to distinguish it from the +specific time T that we are trying to + + align:start position:0% +specific time T that we are trying to + + + align:start position:0% +specific time T that we are trying to +compute the velocity for so now in just + + align:start position:0% +compute the velocity for so now in just + + + align:start position:0% +compute the velocity for so now in just +the same way that we've obtained the + + align:start position:0% +the same way that we've obtained the + + + align:start position:0% +the same way that we've obtained the +velocity by integrating the acceleration + + align:start position:0% +velocity by integrating the acceleration + + + align:start position:0% +velocity by integrating the acceleration +we can integrate again we can integrate + + align:start position:0% +we can integrate again we can integrate + + + align:start position:0% +we can integrate again we can integrate +the velocity to calculate the position + + align:start position:0% +the velocity to calculate the position + + + align:start position:0% +the velocity to calculate the position +so given V of + + align:start position:0% + + + + align:start position:0% + +T we can show that the + + align:start position:0% + + + + align:start position:0% + +position at time T is equal to the + + align:start position:0% +position at time T is equal to the + + + align:start position:0% +position at time T is equal to the +position at time + + align:start position:0% +position at time + + + align:start position:0% +position at time +t plus the integral of the + + align:start position:0% +t plus the integral of the + + + align:start position:0% +t plus the integral of the +velocity as a function of time I'll + + align:start position:0% +velocity as a function of time I'll + + + align:start position:0% +velocity as a function of time I'll +write this as T Prime DT Prime going + + align:start position:0% +write this as T Prime DT Prime going + + + align:start position:0% +write this as T Prime DT Prime going +from T Prime equals T KN to T Prime + + align:start position:0% +from T Prime equals T KN to T Prime + + + align:start position:0% +from T Prime equals T KN to T Prime +equal T so this is exactly analogous to + + align:start position:0% +equal T so this is exactly analogous to + + + align:start position:0% +equal T so this is exactly analogous to +how we computed velocity from + + align:start position:0% +how we computed velocity from + + + align:start position:0% +how we computed velocity from +acceleration by integrating a second + + align:start position:0% +acceleration by integrating a second + + + align:start position:0% +acceleration by integrating a second +time we can go from uh velocity to + + align:start position:0% +time we can go from uh velocity to + + + align:start position:0% +time we can go from uh velocity to +position so once we know the + + align:start position:0% +position so once we know the + + + align:start position:0% +position so once we know the +acceleration a of T we can use + + align:start position:0% +acceleration a of T we can use + + + align:start position:0% +acceleration a of T we can use +integration to compute the velocity V of + + align:start position:0% +integration to compute the velocity V of + + + align:start position:0% +integration to compute the velocity V of +T if we know the velocity at some + + align:start position:0% +T if we know the velocity at some + + + align:start position:0% +T if we know the velocity at some +initial time T KN and we can also + + align:start position:0% +initial time T KN and we can also + + + align:start position:0% +initial time T KN and we can also +compute the position X of T if we know + + align:start position:0% +compute the position X of T if we know + + + align:start position:0% +compute the position X of T if we know +the initial position at time T KN X knot + + align:start position:0% +the initial position at time T KN X knot + + + align:start position:0% +the initial position at time T KN X knot +so we see that given the acceleration we + + align:start position:0% +so we see that given the acceleration we + + + align:start position:0% +so we see that given the acceleration we +can recover the velocity and the + + align:start position:0% +can recover the velocity and the + + + align:start position:0% +can recover the velocity and the +position and as it happens from Newton's + + align:start position:0% +position and as it happens from Newton's + + + align:start position:0% +position and as it happens from Newton's +Second Law if we know the forces acting + + align:start position:0% +Second Law if we know the forces acting + + + align:start position:0% +Second Law if we know the forces acting +on an object that gives us the ability + + align:start position:0% +on an object that gives us the ability + + + align:start position:0% +on an object that gives us the ability +to compute what the acceleration is and + + align:start position:0% +to compute what the acceleration is and + + + align:start position:0% +to compute what the acceleration is and +then given the acceleration we can use + + align:start position:0% +then given the acceleration we can use + + + align:start position:0% +then given the acceleration we can use +integration to find the velocity and the + + align:start position:0% +integration to find the velocity and the + + + align:start position:0% +integration to find the velocity and the +position \ No newline at end of file diff --git a/I0Psvvky-44.txt b/I0Psvvky-44.txt new file mode 100644 index 0000000000000000000000000000000000000000..5a1554c7ce065f5b037c73c25ef0554a6e807bd3 --- /dev/null +++ b/I0Psvvky-44.txt @@ -0,0 +1,17307 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right let's get started + + align:start position:0% +ocw.mit.edu all right let's get started + + + align:start position:0% +ocw.mit.edu all right let's get started +so um today we're going to talk about uh + + align:start position:0% +so um today we're going to talk about uh + + + align:start position:0% +so um today we're going to talk about uh +the system called native client which um + + align:start position:0% +the system called native client which um + + + align:start position:0% +the system called native client which um +is actually a real world system used uh + + align:start position:0% +is actually a real world system used uh + + + align:start position:0% +is actually a real world system used uh +by Google uh as one example they + + align:start position:0% +by Google uh as one example they + + + align:start position:0% +by Google uh as one example they +actually use it in the Chrome browser to + + align:start position:0% +actually use it in the Chrome browser to + + + align:start position:0% +actually use it in the Chrome browser to +allow web applications to run arbitrary + + align:start position:0% +allow web applications to run arbitrary + + + align:start position:0% +allow web applications to run arbitrary +native code it's actually a pretty cool + + align:start position:0% +native code it's actually a pretty cool + + + align:start position:0% +native code it's actually a pretty cool +system and uh it's also an illustration + + align:start position:0% +system and uh it's also an illustration + + + align:start position:0% +system and uh it's also an illustration +of another isolation or sort of + + align:start position:0% +of another isolation or sort of + + + align:start position:0% +of another isolation or sort of +sandboxing or privilege separation + + align:start position:0% +sandboxing or privilege separation + + + align:start position:0% +sandboxing or privilege separation +technique that's called software fault + + align:start position:0% +technique that's called software fault + + + align:start position:0% +technique that's called software fault +isolation that doesn't rely on operating + + align:start position:0% +isolation that doesn't rely on operating + + + align:start position:0% +isolation that doesn't rely on operating +systems to sandbox a process virtual + + align:start position:0% +systems to sandbox a process virtual + + + align:start position:0% +systems to sandbox a process virtual +machines but instead has a very + + align:start position:0% +machines but instead has a very + + + align:start position:0% +machines but instead has a very +different approach to looking at the + + align:start position:0% +different approach to looking at the + + + align:start position:0% +different approach to looking at the +particular instructions in a binary to + + align:start position:0% +particular instructions in a binary to + + + align:start position:0% +particular instructions in a binary to +figure out whether it's going to be safe + + align:start position:0% +figure out whether it's going to be safe + + + align:start position:0% +figure out whether it's going to be safe +to run or not so before we I guess start + + align:start position:0% +to run or not so before we I guess start + + + align:start position:0% +to run or not so before we I guess start +looking at the technical details of this + + align:start position:0% +looking at the technical details of this + + + align:start position:0% +looking at the technical details of this +system um let's figure out why do these + + align:start position:0% +system um let's figure out why do these + + + align:start position:0% +system um let's figure out why do these +guys actually want to run native code + + align:start position:0% +guys actually want to run native code + + + align:start position:0% +guys actually want to run native code +right so the particular context they are + + align:start position:0% +right so the particular context they are + + + align:start position:0% +right so the particular context they are +interested in applying their solution to + + align:start position:0% +interested in applying their solution to + + + align:start position:0% +interested in applying their solution to +is a web browser where you could already + + align:start position:0% +is a web browser where you could already + + + align:start position:0% +is a web browser where you could already +run JavaScript code and maybe Flash and + + align:start position:0% +run JavaScript code and maybe Flash and + + + align:start position:0% +run JavaScript code and maybe Flash and +maybe a couple couple of other things + + align:start position:0% +maybe a couple couple of other things + + + align:start position:0% +maybe a couple couple of other things +why are these guys so excited about + + align:start position:0% +why are these guys so excited about + + + align:start position:0% +why are these guys so excited about +running raw x86 it seems like a step + + align:start position:0% +running raw x86 it seems like a step + + + align:start position:0% +running raw x86 it seems like a step +backwards like really fast computation + + align:start position:0% +backwards like really fast computation + + + align:start position:0% +backwards like really fast computation +yeah so one huge advantage of native + + align:start position:0% +yeah so one huge advantage of native + + + align:start position:0% +yeah so one huge advantage of native +code even though it might be unsafe from + + align:start position:0% +code even though it might be unsafe from + + + align:start position:0% +code even though it might be unsafe from +some perspectives uh it's really high + + align:start position:0% +some perspectives uh it's really high + + + align:start position:0% +some perspectives uh it's really high +performance whatever you can do in + + align:start position:0% +performance whatever you can do in + + + align:start position:0% +performance whatever you can do in +JavaScript presumably you can just write + + align:start position:0% +JavaScript presumably you can just write + + + align:start position:0% +JavaScript presumably you can just write +the same thing in assembly and it'll go + + align:start position:0% +the same thing in assembly and it'll go + + + align:start position:0% +the same thing in assembly and it'll go +at least as fast probably much faster + + align:start position:0% +at least as fast probably much faster + + + align:start position:0% +at least as fast probably much faster +any other reasons yeah code yeah so + + align:start position:0% +any other reasons yeah code yeah so + + + align:start position:0% +any other reasons yeah code yeah so +another big thing is maybe not + + align:start position:0% +another big thing is maybe not + + + align:start position:0% +another big thing is maybe not +everything is written in JavaScript so + + align:start position:0% +everything is written in JavaScript so + + + align:start position:0% +everything is written in JavaScript so +if you have an existing + + align:start position:0% +if you have an existing + + + align:start position:0% +if you have an existing +application I guess Legacy in Industry + + align:start position:0% +application I guess Legacy in Industry + + + align:start position:0% +application I guess Legacy in Industry +terminology uh if you have some existing + + align:start position:0% +terminology uh if you have some existing + + + align:start position:0% +terminology uh if you have some existing +code that you really want to run in the + + align:start position:0% +code that you really want to run in the + + + align:start position:0% +code that you really want to run in the +web uh then this seems like a great + + align:start position:0% +web uh then this seems like a great + + + align:start position:0% +web uh then this seems like a great +solution because you can just take an + + align:start position:0% +solution because you can just take an + + + align:start position:0% +solution because you can just take an +existing Library like some complicated I + + align:start position:0% +existing Library like some complicated I + + + align:start position:0% +existing Library like some complicated I +don't know Graphics processing engine + + align:start position:0% +don't know Graphics processing engine + + + align:start position:0% +don't know Graphics processing engine +that's both performance sensitive and + + align:start position:0% +that's both performance sensitive and + + + align:start position:0% +that's both performance sensitive and +like lots of complicated stuff you don't + + align:start position:0% +like lots of complicated stuff you don't + + + align:start position:0% +like lots of complicated stuff you don't +want to reimplement then this seems like + + align:start position:0% +want to reimplement then this seems like + + + align:start position:0% +want to reimplement then this seems like +a good + + align:start position:0% +a good + + + align:start position:0% +a good +solution anything else if you're just + + align:start position:0% +solution anything else if you're just + + + align:start position:0% +solution anything else if you're just +like programming a new web app should + + align:start position:0% +like programming a new web app should + + + align:start position:0% +like programming a new web app should +you use native client if you don't care + + align:start position:0% +you use native client if you don't care + + + align:start position:0% +you use native client if you don't care +about Legacy or performance so + + align:start position:0% + + + + align:start position:0% + +much any other + + align:start position:0% +much any other + + + align:start position:0% +much any other +reasons I guess another yeah you don't + + align:start position:0% +reasons I guess another yeah you don't + + + align:start position:0% +reasons I guess another yeah you don't +have to use JavaScript yeah that's an + + align:start position:0% +have to use JavaScript yeah that's an + + + align:start position:0% +have to use JavaScript yeah that's an +awesome reason right like you know it + + align:start position:0% +awesome reason right like you know it + + + align:start position:0% +awesome reason right like you know it +might if you don't like JavaScript then + + align:start position:0% +might if you don't like JavaScript then + + + align:start position:0% +might if you don't like JavaScript then +you don't have to use it right you can + + align:start position:0% +you don't have to use it right you can + + + align:start position:0% +you don't have to use it right you can +actually use I don't know well see if + + align:start position:0% +actually use I don't know well see if + + + align:start position:0% +actually use I don't know well see if +you're so inclined you could run python + + align:start position:0% +you're so inclined you could run python + + + align:start position:0% +you're so inclined you could run python +code you could write hascal whatever you + + align:start position:0% +code you could write hascal whatever you + + + align:start position:0% +code you could write hascal whatever you +think is useful uh you can actually + + align:start position:0% +think is useful uh you can actually + + + align:start position:0% +think is useful uh you can actually +support other languages all of a + + align:start position:0% + + + + align:start position:0% + +sudden so this is a you know reasonably + + align:start position:0% +sudden so this is a you know reasonably + + + align:start position:0% +sudden so this is a you know reasonably +compelling + + align:start position:0% +compelling + + + align:start position:0% +compelling +list of sort of motivation uh for them + + align:start position:0% +list of sort of motivation uh for them + + + align:start position:0% +list of sort of motivation uh for them +to run native code in the browser and um + + align:start position:0% +to run native code in the browser and um + + + align:start position:0% +to run native code in the browser and um +turns out to be reasonably tricky to get + + align:start position:0% +turns out to be reasonably tricky to get + + + align:start position:0% +turns out to be reasonably tricky to get +right so we'll look at the technical + + align:start position:0% +right so we'll look at the technical + + + align:start position:0% +right so we'll look at the technical +details I guess of how it works in a + + align:start position:0% +details I guess of how it works in a + + + align:start position:0% +details I guess of how it works in a +second but just to show you guys what + + align:start position:0% +second but just to show you guys what + + + align:start position:0% +second but just to show you guys what +this paper is talking about I just want + + align:start position:0% +this paper is talking about I just want + + + align:start position:0% +this paper is talking about I just want +to show a very simple tutorial demo + + align:start position:0% +to show a very simple tutorial demo + + + align:start position:0% +to show a very simple tutorial demo +almost that I got out of their native + + align:start position:0% +almost that I got out of their native + + + align:start position:0% +almost that I got out of their native +client you know website it's fairly + + align:start position:0% +client you know website it's fairly + + + align:start position:0% +client you know website it's fairly +simple as it turns out to just take a + + align:start position:0% +simple as it turns out to just take a + + + align:start position:0% +simple as it turns out to just take a +C++ or a c program and run it in the + + align:start position:0% +C++ or a c program and run it in the + + + align:start position:0% +C++ or a c program and run it in the +browser so just to show you what this + + align:start position:0% +browser so just to show you what this + + + align:start position:0% +browser so just to show you what this +looks like here's the basically a demo I + + align:start position:0% +looks like here's the basically a demo I + + + align:start position:0% +looks like here's the basically a demo I +mostly sort of took from one of their + + align:start position:0% +mostly sort of took from one of their + + + align:start position:0% +mostly sort of took from one of their +examples so you can look at you know a + + align:start position:0% +examples so you can look at you know a + + + align:start position:0% +examples so you can look at you know a +web page like this index HTML file and + + align:start position:0% +web page like this index HTML file and + + + align:start position:0% +web page like this index HTML file and +inside of it you have a bunch of + + align:start position:0% +inside of it you have a bunch of + + + align:start position:0% +inside of it you have a bunch of +JavaScript code and the reason this + + align:start position:0% +JavaScript code and the reason this + + + align:start position:0% +JavaScript code and the reason this +JavaScript code exists is to sort of + + align:start position:0% +JavaScript code exists is to sort of + + + align:start position:0% +JavaScript code exists is to sort of +interact with the native client piece so + + align:start position:0% +interact with the native client piece so + + + align:start position:0% +interact with the native client piece so +the way you can sort of think of this + + align:start position:0% +the way you can sort of think of this + + + align:start position:0% +the way you can sort of think of this +running in the browser is that you have + + align:start position:0% +running in the browser is that you have + + + align:start position:0% +running in the browser is that you have +the + + align:start position:0% +the + + + align:start position:0% +the +browser you have well we'll talk about + + align:start position:0% +browser you have well we'll talk about + + + align:start position:0% +browser you have well we'll talk about +much more about web security later but + + align:start position:0% +much more about web security later but + + + align:start position:0% +much more about web security later but +roughly you have some sort of a page uh + + align:start position:0% +roughly you have some sort of a page uh + + + align:start position:0% +roughly you have some sort of a page uh +web page that contains JavaScript code + + align:start position:0% +web page that contains JavaScript code + + + align:start position:0% +web page that contains JavaScript code +and this runs with the pages Privileges + + align:start position:0% +and this runs with the pages Privileges + + + align:start position:0% +and this runs with the pages Privileges +and this can do you know various things + + align:start position:0% +and this can do you know various things + + + align:start position:0% +and this can do you know various things +to the web page itself maybe talk to the + + align:start position:0% +to the web page itself maybe talk to the + + + align:start position:0% +to the web page itself maybe talk to the +network in some circumstances but what + + align:start position:0% +network in some circumstances but what + + + align:start position:0% +network in some circumstances but what +Native client allows you to do is to + + align:start position:0% +Native client allows you to do is to + + + align:start position:0% +Native client allows you to do is to +have this native client module running + + align:start position:0% +have this native client module running + + + align:start position:0% +have this native client module running +sort of to the side in the browser as + + align:start position:0% +sort of to the side in the browser as + + + align:start position:0% +sort of to the side in the browser as +well and the JavaScript code can + + align:start position:0% +well and the JavaScript code can + + + align:start position:0% +well and the JavaScript code can +actually interact with the native client + + align:start position:0% +actually interact with the native client + + + align:start position:0% +actually interact with the native client +module and get responses + + align:start position:0% +module and get responses + + + align:start position:0% +module and get responses +back and what you see here in this web + + align:start position:0% +back and what you see here in this web + + + align:start position:0% +back and what you see here in this web +page is the little bit of JavaScript + + align:start position:0% +page is the little bit of JavaScript + + + align:start position:0% +page is the little bit of JavaScript +code that's necessary a native client to + + align:start position:0% +code that's necessary a native client to + + + align:start position:0% +code that's necessary a native client to +interact with a particular nackle module + + align:start position:0% +interact with a particular nackle module + + + align:start position:0% +interact with a particular nackle module +that we're going to be running and you + + align:start position:0% +that we're going to be running and you + + + align:start position:0% +that we're going to be running and you +can send messages to this module the way + + align:start position:0% +can send messages to this module the way + + + align:start position:0% +can send messages to this module the way +you do it is you take this module object + + align:start position:0% +you do it is you take this module object + + + align:start position:0% +you do it is you take this module object +in JavaScript and you call Post message + + align:start position:0% +in JavaScript and you call Post message + + + align:start position:0% +in JavaScript and you call Post message +in it and you can actually Supply a + + align:start position:0% +in it and you can actually Supply a + + + align:start position:0% +in it and you can actually Supply a +message to send to the native client + + align:start position:0% +message to send to the native client + + + align:start position:0% +message to send to the native client +module and when the native client module + + align:start position:0% +module and when the native client module + + + align:start position:0% +module and when the native client module +responds it'll run this handle message + + align:start position:0% +responds it'll run this handle message + + + align:start position:0% +responds it'll run this handle message +function in JavaScript and in this + + align:start position:0% +function in JavaScript and in this + + + align:start position:0% +function in JavaScript and in this +particular case it just pops up an alert + + align:start position:0% +particular case it just pops up an alert + + + align:start position:0% +particular case it just pops up an alert +dialogue box in my + + align:start position:0% +dialogue box in my + + + align:start position:0% +dialogue box in my +browser so this is actually air simple + + align:start position:0% +browser so this is actually air simple + + + align:start position:0% +browser so this is actually air simple +interface from the web page side from + + align:start position:0% +interface from the web page side from + + + align:start position:0% +interface from the web page side from +the JavaScript side and the only thing + + align:start position:0% +the JavaScript side and the only thing + + + align:start position:0% +the JavaScript side and the only thing +you Additionally you have to do is you + + align:start position:0% +you Additionally you have to do is you + + + align:start position:0% +you Additionally you have to do is you +actually have to declare this native + + align:start position:0% +actually have to declare this native + + + align:start position:0% +actually have to declare this native +client module this way so you just say + + align:start position:0% +client module this way so you just say + + + align:start position:0% +client module this way so you just say +embed a module with a particular ID and + + align:start position:0% +embed a module with a particular ID and + + + align:start position:0% +embed a module with a particular ID and +the sort of most interesting part is the + + align:start position:0% +the sort of most interesting part is the + + + align:start position:0% +the sort of most interesting part is the +source equals hello. some nmf part + + align:start position:0% +source equals hello. some nmf part + + + align:start position:0% +source equals hello. some nmf part +attribute and this one just says well + + align:start position:0% +attribute and this one just says well + + + align:start position:0% +attribute and this one just says well +here's the roughly executable file that + + align:start position:0% +here's the roughly executable file that + + + align:start position:0% +here's the roughly executable file that +you need to load and start running in + + align:start position:0% +you need to load and start running in + + + align:start position:0% +you need to load and start running in +the native side of things and this + + align:start position:0% +the native side of things and this + + + align:start position:0% +the native side of things and this +native code actually looks like any + + align:start position:0% +native code actually looks like any + + + align:start position:0% +native code actually looks like any +other C++ code you might write roughly + + align:start position:0% +other C++ code you might write roughly + + + align:start position:0% +other C++ code you might write roughly +so here's the program the interesting + + align:start position:0% +so here's the program the interesting + + + align:start position:0% +so here's the program the interesting +part is roughly this handle message + + align:start position:0% +part is roughly this handle message + + + align:start position:0% +part is roughly this handle message +function so this is a C++ class and + + align:start position:0% +function so this is a C++ class and + + + align:start position:0% +function so this is a C++ class and +whenever the JavaScript code sends some + + align:start position:0% +whenever the JavaScript code sends some + + + align:start position:0% +whenever the JavaScript code sends some +message to the native code it'll + + align:start position:0% +message to the native code it'll + + + align:start position:0% +message to the native code it'll +actually run this function and it'll + + align:start position:0% +actually run this function and it'll + + + align:start position:0% +actually run this function and it'll +check if the message that's being sent + + align:start position:0% +check if the message that's being sent + + + align:start position:0% +check if the message that's being sent +is hello and if so construct a reply + + align:start position:0% +is hello and if so construct a reply + + + align:start position:0% +is hello and if so construct a reply +string of some sort and send it back + + align:start position:0% +string of some sort and send it back + + + align:start position:0% +string of some sort and send it back +it's like fairly simple stuff but just + + align:start position:0% +it's like fairly simple stuff but just + + + align:start position:0% +it's like fairly simple stuff but just +to be concrete uh let's try to run it + + align:start position:0% +to be concrete uh let's try to run it + + + align:start position:0% +to be concrete uh let's try to run it +and see what happens so we can actually + + align:start position:0% +and see what happens so we can actually + + + align:start position:0% +and see what happens so we can actually +build it + + align:start position:0% +build it + + + align:start position:0% +build it +and uh run a little web server that uh + + align:start position:0% +and uh run a little web server that uh + + + align:start position:0% +and uh run a little web server that uh +is going + + align:start position:0% +is going + + + align:start position:0% +is going +to serve up this page and Native client + + align:start position:0% +to serve up this page and Native client + + + align:start position:0% +to serve up this page and Native client +module so here I can go to this URL and + + align:start position:0% +module so here I can go to this URL and + + + align:start position:0% +module so here I can go to this URL and +here we go right it's actually loaded in + + align:start position:0% +here we go right it's actually loaded in + + + align:start position:0% +here we go right it's actually loaded in +the module the module seems to have + + align:start position:0% +the module the module seems to have + + + align:start position:0% +the module the module seems to have +gotten our Hello message from JavaScript + + align:start position:0% +gotten our Hello message from JavaScript + + + align:start position:0% +gotten our Hello message from JavaScript +replied back with the string back to + + align:start position:0% +replied back with the string back to + + + align:start position:0% +replied back with the string back to +JavaScript and the JavaScript code + + align:start position:0% +JavaScript and the JavaScript code + + + align:start position:0% +JavaScript and the JavaScript code +popped up a dialog box containing that + + align:start position:0% +popped up a dialog box containing that + + + align:start position:0% +popped up a dialog box containing that +response so it actually does kind of + + align:start position:0% +response so it actually does kind of + + + align:start position:0% +response so it actually does kind of +work um we can try to see if we can + + align:start position:0% +work um we can try to see if we can + + + align:start position:0% +work um we can try to see if we can +crash native client but hopefully not + + align:start position:0% +crash native client but hopefully not + + + align:start position:0% +crash native client but hopefully not +but uh we can you know take this code + + align:start position:0% +but uh we can you know take this code + + + align:start position:0% +but uh we can you know take this code +and we have this buffer we could you + + align:start position:0% +and we have this buffer we could you + + + align:start position:0% +and we have this buffer we could you +know write a bunch of A's to it I don't + + align:start position:0% +know write a bunch of A's to it I don't + + + align:start position:0% +know write a bunch of A's to it I don't +know quite a lot um and see what happens + + align:start position:0% +know quite a lot um and see what happens + + + align:start position:0% +know quite a lot um and see what happens +so hopefully this shouldn't crash my + + align:start position:0% +so hopefully this shouldn't crash my + + + align:start position:0% +so hopefully this shouldn't crash my +browser because native client is trying + + align:start position:0% +browser because native client is trying + + + align:start position:0% +browser because native client is trying +to provide isolation um um but let's see + + align:start position:0% +to provide isolation um um but let's see + + + align:start position:0% +to provide isolation um um but let's see +what + + align:start position:0% +what + + + align:start position:0% +what +happens so we can rebuild it rerun the + + align:start position:0% +happens so we can rebuild it rerun the + + + align:start position:0% +happens so we can rebuild it rerun the +web server and here if you run it + + align:start position:0% +web server and here if you run it + + + align:start position:0% +web server and here if you run it +nothing happens we don't get the message + + align:start position:0% +nothing happens we don't get the message + + + align:start position:0% +nothing happens we don't get the message +back anymore so clearly message didn't + + align:start position:0% +back anymore so clearly message didn't + + + align:start position:0% +back anymore so clearly message didn't +get sent back from the Native client + + align:start position:0% +get sent back from the Native client + + + align:start position:0% +get sent back from the Native client +module because I don't see any popup we + + align:start position:0% +module because I don't see any popup we + + + align:start position:0% +module because I don't see any popup we +can look at the JavaScript console here + + align:start position:0% +can look at the JavaScript console here + + + align:start position:0% +can look at the JavaScript console here +and we can see that the native client + + align:start position:0% +and we can see that the native client + + + align:start position:0% +and we can see that the native client +module tells us knle module crashed so + + align:start position:0% +module tells us knle module crashed so + + + align:start position:0% +module tells us knle module crashed so +somehow it caught this buff overflow uh + + align:start position:0% +somehow it caught this buff overflow uh + + + align:start position:0% +somehow it caught this buff overflow uh +scribbling over some memory or maybe it + + align:start position:0% +scribbling over some memory or maybe it + + + align:start position:0% +scribbling over some memory or maybe it +jump to some bad address containing all + + align:start position:0% +jump to some bad address containing all + + + align:start position:0% +jump to some bad address containing all +A's uh but in any case the native client + + align:start position:0% +A's uh but in any case the native client + + + align:start position:0% +A's uh but in any case the native client +module is actually able to contain this + + align:start position:0% +module is actually able to contain this + + + align:start position:0% +module is actually able to contain this +without this arbitary sort of memory + + align:start position:0% +without this arbitary sort of memory + + + align:start position:0% +without this arbitary sort of memory +corruption in the module affecting the + + align:start position:0% +corruption in the module affecting the + + + align:start position:0% +corruption in the module affecting the +rest of the + + align:start position:0% +rest of the + + + align:start position:0% +rest of the +browser so this is roughly just a sort + + align:start position:0% +browser so this is roughly just a sort + + + align:start position:0% +browser so this is roughly just a sort +of quick demo of what the system is and + + align:start position:0% +of quick demo of what the system is and + + + align:start position:0% +of quick demo of what the system is and +um what how how you use it as as a end + + align:start position:0% +um what how how you use it as as a end + + + align:start position:0% +um what how how you use it as as a end +user or web + + align:start position:0% +user or web + + + align:start position:0% +user or web +developer so let's look now some more so + + align:start position:0% +developer so let's look now some more so + + + align:start position:0% +developer so let's look now some more so +that's all in terms of demos I have to + + align:start position:0% +that's all in terms of demos I have to + + + align:start position:0% +that's all in terms of demos I have to +show you uh so let's look more now in at + + align:start position:0% +show you uh so let's look more now in at + + + align:start position:0% +show you uh so let's look more now in at +uh how Native client is going to work or + + align:start position:0% +uh how Native client is going to work or + + + align:start position:0% +uh how Native client is going to work or +perhaps even why we need this particular + + align:start position:0% +perhaps even why we need this particular + + + align:start position:0% +perhaps even why we need this particular +design as opposed to some of the + + align:start position:0% +design as opposed to some of the + + + align:start position:0% +design as opposed to some of the +Alternatives so so if your goal I guess + + align:start position:0% +Alternatives so so if your goal I guess + + + align:start position:0% +Alternatives so so if your goal I guess +is to sandbox native + + align:start position:0% +is to sandbox native + + + align:start position:0% +is to sandbox native +code there's a number of Alternatives + + align:start position:0% +code there's a number of Alternatives + + + align:start position:0% +code there's a number of Alternatives +you could make right people actually had + + align:start position:0% +you could make right people actually had + + + align:start position:0% +you could make right people actually had +these problems before of performance + + align:start position:0% +these problems before of performance + + + align:start position:0% +these problems before of performance +existing Legacy code and other languages + + align:start position:0% +existing Legacy code and other languages + + + align:start position:0% +existing Legacy code and other languages +before native client came around and + + align:start position:0% +before native client came around and + + + align:start position:0% +before native client came around and +people just solved them in different + + align:start position:0% +people just solved them in different + + + align:start position:0% +people just solved them in different +ways that maybe weren't as satisfying in + + align:start position:0% +ways that maybe weren't as satisfying in + + + align:start position:0% +ways that maybe weren't as satisfying in +from a security standpoint orbe a + + align:start position:0% +from a security standpoint orbe a + + + align:start position:0% +from a security standpoint orbe a +usability standpoint as native client + + align:start position:0% +usability standpoint as native client + + + align:start position:0% +usability standpoint as native client +but it is doable so let's see so what so + + align:start position:0% +but it is doable so let's see so what so + + + align:start position:0% +but it is doable so let's see so what so +what what could you do if you really + + align:start position:0% +what what could you do if you really + + + align:start position:0% +what what could you do if you really +want to run native code in a + + align:start position:0% + + + + align:start position:0% + +browser so one option that people did + + align:start position:0% +browser so one option that people did + + + align:start position:0% +browser so one option that people did +was to trust the + + align:start position:0% + + + + align:start position:0% + +developer and maybe a variant of this + + align:start position:0% +developer and maybe a variant of this + + + align:start position:0% +developer and maybe a variant of this +approach is to ask the user whether they + + align:start position:0% +approach is to ask the user whether they + + + align:start position:0% +approach is to ask the user whether they +want to run some piece of code in their + + align:start position:0% +want to run some piece of code in their + + + align:start position:0% +want to run some piece of code in their +browser or + + align:start position:0% +browser or + + + align:start position:0% +browser or +not so does everyone understand roughly + + align:start position:0% +not so does everyone understand roughly + + + align:start position:0% +not so does everyone understand roughly +what the plan is right like instead of + + align:start position:0% +what the plan is right like instead of + + + align:start position:0% +what the plan is right like instead of +having that whole native client + + align:start position:0% +having that whole native client + + + align:start position:0% +having that whole native client +compilation strategy I could have just + + align:start position:0% +compilation strategy I could have just + + + align:start position:0% +compilation strategy I could have just +built a simple C program served it up on + + align:start position:0% +built a simple C program served it up on + + + align:start position:0% +built a simple C program served it up on +the browser and maybe the browser asked + + align:start position:0% +the browser and maybe the browser asked + + + align:start position:0% +the browser and maybe the browser asked +do you want to run this site or not if I + + align:start position:0% +do you want to run this site or not if I + + + align:start position:0% +do you want to run this site or not if I +click yes then it accidentally scri over + + align:start position:0% +click yes then it accidentally scri over + + + align:start position:0% +click yes then it accidentally scri over +the browser's memory and crashes the + + align:start position:0% +the browser's memory and crashes the + + + align:start position:0% +the browser's memory and crashes the +browser + + align:start position:0% +browser + + + align:start position:0% +browser +so it's possible Right it certainly + + align:start position:0% +so it's possible Right it certainly + + + align:start position:0% +so it's possible Right it certainly +solves all these goals but what's wrong + + align:start position:0% +solves all these goals but what's wrong + + + align:start position:0% +solves all these goals but what's wrong +with it well I guess there's the + + align:start position:0% +with it well I guess there's the + + + align:start position:0% +with it well I guess there's the +insecurity part uh which is unfortunate + + align:start position:0% +insecurity part uh which is unfortunate + + + align:start position:0% +insecurity part uh which is unfortunate +uh one way to potentially get around + + align:start position:0% +uh one way to potentially get around + + + align:start position:0% +uh one way to potentially get around +this and some systems did like uh + + align:start position:0% +this and some systems did like uh + + + align:start position:0% +this and some systems did like uh +Microsoft had the system called active + + align:start position:0% +Microsoft had the system called active + + + align:start position:0% +Microsoft had the system called active +X that basically implemented this plan + + align:start position:0% +X that basically implemented this plan + + + align:start position:0% +X that basically implemented this plan +you could serve binaries to IE the + + align:start position:0% +you could serve binaries to IE the + + + align:start position:0% +you could serve binaries to IE the +browser on your machine and as long as + + align:start position:0% +browser on your machine and as long as + + + align:start position:0% +browser on your machine and as long as +it came with a certificate from a + + align:start position:0% +it came with a certificate from a + + + align:start position:0% +it came with a certificate from a +particular developer signed by let's say + + align:start position:0% +particular developer signed by let's say + + + align:start position:0% +particular developer signed by let's say +Microsoft or someone else then it would + + align:start position:0% +Microsoft or someone else then it would + + + align:start position:0% +Microsoft or someone else then it would +actually run this code so what do you + + align:start position:0% +actually run this code so what do you + + + align:start position:0% +actually run this code so what do you +guys think about this plan is this + + align:start position:0% +guys think about this plan is this + + + align:start position:0% +guys think about this plan is this +useful yeah well doesn't tell you + + align:start position:0% +useful yeah well doesn't tell you + + + align:start position:0% +useful yeah well doesn't tell you +anything about does just a signature on + + align:start position:0% +anything about does just a signature on + + + align:start position:0% +anything about does just a signature on +the code the code should be contining + + align:start position:0% +the code the code should be contining + + + align:start position:0% +the code the code should be contining +malicious that's right yeah so right you + + align:start position:0% +malicious that's right yeah so right you + + + align:start position:0% +malicious that's right yeah so right you +really have to put quite a bit of trust + + align:start position:0% +really have to put quite a bit of trust + + + align:start position:0% +really have to put quite a bit of trust +into whoever it is that's signing this + + align:start position:0% +into whoever it is that's signing this + + + align:start position:0% +into whoever it is that's signing this +that they will only sign binaries that + + align:start position:0% +that they will only sign binaries that + + + align:start position:0% +that they will only sign binaries that +will not do something bad um but it's + + align:start position:0% +will not do something bad um but it's + + + align:start position:0% +will not do something bad um but it's +kind of vague what this bad thing is and + + align:start position:0% +kind of vague what this bad thing is and + + + align:start position:0% +kind of vague what this bad thing is and +presumably they're just writing C code + + align:start position:0% +presumably they're just writing C code + + + align:start position:0% +presumably they're just writing C code +and you know signing it blindly without + + align:start position:0% +and you know signing it blindly without + + + align:start position:0% +and you know signing it blindly without +doing a huge amount of work um in which + + align:start position:0% +doing a huge amount of work um in which + + + align:start position:0% +doing a huge amount of work um in which +case you might well be susceptible to + + align:start position:0% +case you might well be susceptible to + + + align:start position:0% +case you might well be susceptible to +some problems down the line what if we + + align:start position:0% +some problems down the line what if we + + + align:start position:0% +some problems down the line what if we +ask the user yeah that like we read that + + align:start position:0% +ask the user yeah that like we read that + + + align:start position:0% +ask the user yeah that like we read that +paper in 6033 where user sometimes will + + align:start position:0% +paper in 6033 where user sometimes will + + + align:start position:0% +paper in 6033 where user sometimes will +not even read the message oh yeah yeah + + align:start position:0% +not even read the message oh yeah yeah + + + align:start position:0% +not even read the message oh yeah yeah +yeah right like the user's goal is to + + align:start position:0% +yeah right like the user's goal is to + + + align:start position:0% +yeah right like the user's goal is to +run this thing and uh you know even if + + align:start position:0% +run this thing and uh you know even if + + + align:start position:0% +run this thing and uh you know even if +the user wants to be cautious it's + + align:start position:0% +the user wants to be cautious it's + + + align:start position:0% +the user wants to be cautious it's +actually not clear how should the user + + align:start position:0% +actually not clear how should the user + + + align:start position:0% +actually not clear how should the user +decide like suppose I really want to + + align:start position:0% +decide like suppose I really want to + + + align:start position:0% +decide like suppose I really want to +understand should I allow this program + + align:start position:0% +understand should I allow this program + + + align:start position:0% +understand should I allow this program +to run all it tells me is well maybe it + + align:start position:0% +to run all it tells me is well maybe it + + + align:start position:0% +to run all it tells me is well maybe it +came from google.com or microsoft.com + + align:start position:0% +came from google.com or microsoft.com + + + align:start position:0% +came from google.com or microsoft.com +and its file name is food. exe I don't + + align:start position:0% +and its file name is food. exe I don't + + + align:start position:0% +and its file name is food. exe I don't +know like what's in there right even if + + align:start position:0% +know like what's in there right even if + + + align:start position:0% +know like what's in there right even if +I disassemble the code it might be very + + align:start position:0% +I disassemble the code it might be very + + + align:start position:0% +I disassemble the code it might be very +hard to tell whether it's going to do + + align:start position:0% +hard to tell whether it's going to do + + + align:start position:0% +hard to tell whether it's going to do +something bad or not so it's actually + + align:start position:0% +something bad or not so it's actually + + + align:start position:0% +something bad or not so it's actually +really hard to decide so one way to + + align:start position:0% +really hard to decide so one way to + + + align:start position:0% +really hard to decide so one way to +think of native client is it's a + + align:start position:0% +think of native client is it's a + + + align:start position:0% +think of native client is it's a +mechanism by which users can actually + + align:start position:0% +mechanism by which users can actually + + + align:start position:0% +mechanism by which users can actually +get some confidence whether they should + + align:start position:0% +get some confidence whether they should + + + align:start position:0% +get some confidence whether they should +say yes or not to running this thing so + + align:start position:0% +say yes or not to running this thing so + + + align:start position:0% +say yes or not to running this thing so +in practice I guess like Paul Jan was + + align:start position:0% +in practice I guess like Paul Jan was + + + align:start position:0% +in practice I guess like Paul Jan was +giving this guest lecture last week and + + align:start position:0% +giving this guest lecture last week and + + + align:start position:0% +giving this guest lecture last week and +he suggested that you should enable this + + align:start position:0% +he suggested that you should enable this + + + align:start position:0% +he suggested that you should enable this +click to play extension and chrome so + + align:start position:0% +click to play extension and chrome so + + + align:start position:0% +click to play extension and chrome so +every extension including native client + + align:start position:0% +every extension including native client + + + align:start position:0% +every extension including native client +you should first click on this thing + + align:start position:0% +you should first click on this thing + + + align:start position:0% +you should first click on this thing +before it starts running so in some way + + align:start position:0% +before it starts running so in some way + + + align:start position:0% +before it starts running so in some way +let's ask the user but then the user + + align:start position:0% +let's ask the user but then the user + + + align:start position:0% +let's ask the user but then the user +actually has some sense that well if I + + align:start position:0% +actually has some sense that well if I + + + align:start position:0% +actually has some sense that well if I +click it I'm still hopefully safe in the + + align:start position:0% +click it I'm still hopefully safe in the + + + align:start position:0% +click it I'm still hopefully safe in the +sense that native client will protect me + + align:start position:0% +sense that native client will protect me + + + align:start position:0% +sense that native client will protect me +so the two aren't necessarily exclusive + + align:start position:0% +so the two aren't necessarily exclusive + + + align:start position:0% +so the two aren't necessarily exclusive +but you really want some technical + + align:start position:0% +but you really want some technical + + + align:start position:0% +but you really want some technical +guarantee from native client that + + align:start position:0% +guarantee from native client that + + + align:start position:0% +guarantee from native client that +ensures that even if you say yes there's + + align:start position:0% +ensures that even if you say yes there's + + + align:start position:0% +ensures that even if you say yes there's +something meaningful that is enforcing + + align:start position:0% +something meaningful that is enforcing + + + align:start position:0% +something meaningful that is enforcing +your + + align:start position:0% +your + + + align:start position:0% +your +security soes this make + + align:start position:0% +security soes this make + + + align:start position:0% +security soes this make +sense okay so the other I guess approach + + align:start position:0% +sense okay so the other I guess approach + + + align:start position:0% +sense okay so the other I guess approach +that uh people have taken is uh to use + + align:start position:0% +that uh people have taken is uh to use + + + align:start position:0% +that uh people have taken is uh to use +Os or Hardware sandboxing or + + align:start position:0% + + + + align:start position:0% + +isolation so this is uh things we looked + + align:start position:0% +isolation so this is uh things we looked + + + align:start position:0% +isolation so this is uh things we looked +at in the last couple of lectures so uh + + align:start position:0% +at in the last couple of lectures so uh + + + align:start position:0% +at in the last couple of lectures so uh +maybe you would use Unix isolation + + align:start position:0% +maybe you would use Unix isolation + + + align:start position:0% +maybe you would use Unix isolation +mechanisms uh maybe if you had something + + align:start position:0% +mechanisms uh maybe if you had something + + + align:start position:0% +mechanisms uh maybe if you had something +more sophisticated if you're running on + + align:start position:0% +more sophisticated if you're running on + + + align:start position:0% +more sophisticated if you're running on +FreeBSD maybe You' use capsicum it seems + + align:start position:0% +FreeBSD maybe You' use capsicum it seems + + + align:start position:0% +FreeBSD maybe You' use capsicum it seems +very well suited to sandboxing some + + align:start position:0% +very well suited to sandboxing some + + + align:start position:0% +very well suited to sandboxing some +piece of code because you could give it + + align:start position:0% +piece of code because you could give it + + + align:start position:0% +piece of code because you could give it +very few two capabilities and then seems + + align:start position:0% +very few two capabilities and then seems + + + align:start position:0% +very few two capabilities and then seems +great and Linux has a similar mechanism + + align:start position:0% +great and Linux has a similar mechanism + + + align:start position:0% +great and Linux has a similar mechanism +called SEC comp that we briefly touched + + align:start position:0% +called SEC comp that we briefly touched + + + align:start position:0% +called SEC comp that we briefly touched +on in last lecture that could allow you + + align:start position:0% +on in last lecture that could allow you + + + align:start position:0% +on in last lecture that could allow you +to do similar + + align:start position:0% +to do similar + + + align:start position:0% +to do similar +things so it seems like there's already + + align:start position:0% +things so it seems like there's already + + + align:start position:0% +things so it seems like there's already +a mechanism for running code and + + align:start position:0% +a mechanism for running code and + + + align:start position:0% +a mechanism for running code and +isolation on your machine why are these + + align:start position:0% +isolation on your machine why are these + + + align:start position:0% +isolation on your machine why are these +guys opposed to using this existing + + align:start position:0% +guys opposed to using this existing + + + align:start position:0% +guys opposed to using this existing +solution and they're like Reinventing + + align:start position:0% +solution and they're like Reinventing + + + align:start position:0% +solution and they're like Reinventing +the wheel for some + + align:start position:0% +the wheel for some + + + align:start position:0% +the wheel for some +reason so what's going + + align:start position:0% +reason so what's going + + + align:start position:0% +reason so what's going +on yeah oh yeah maybe they want to + + align:start position:0% +on yeah oh yeah maybe they want to + + + align:start position:0% +on yeah oh yeah maybe they want to +minimize the PCD + + align:start position:0% +minimize the PCD + + + align:start position:0% +minimize the PCD +yeah so in some sense maybe they don't + + align:start position:0% +yeah so in some sense maybe they don't + + + align:start position:0% +yeah so in some sense maybe they don't +want to trust uh the operating system so + + align:start position:0% +want to trust uh the operating system so + + + align:start position:0% +want to trust uh the operating system so +maybe they're here they're actually + + align:start position:0% +maybe they're here they're actually + + + align:start position:0% +maybe they're here they're actually +worried about OS + + align:start position:0% +worried about OS + + + align:start position:0% +worried about OS +bugs it might be that the FreeBSD kernel + + align:start position:0% +bugs it might be that the FreeBSD kernel + + + align:start position:0% +bugs it might be that the FreeBSD kernel +or the Linux kernel has quite a lot of C + + align:start position:0% +or the Linux kernel has quite a lot of C + + + align:start position:0% +or the Linux kernel has quite a lot of C +code written that they don't want to + + align:start position:0% +code written that they don't want to + + + align:start position:0% +code written that they don't want to +audit for correctness or maybe can't + + align:start position:0% +audit for correctness or maybe can't + + + align:start position:0% +audit for correctness or maybe can't +even audit for correctness even if they + + align:start position:0% +even audit for correctness even if they + + + align:start position:0% +even audit for correctness even if they +wanted to and in one of these capsicum + + align:start position:0% +wanted to and in one of these capsicum + + + align:start position:0% +wanted to and in one of these capsicum +or seccom based isolation plans you + + align:start position:0% +or seccom based isolation plans you + + + align:start position:0% +or seccom based isolation plans you +probably do trust quite a bit of code in + + align:start position:0% +probably do trust quite a bit of code in + + + align:start position:0% +probably do trust quite a bit of code in +the kernel to be correct for the sandbox + + align:start position:0% +the kernel to be correct for the sandbox + + + align:start position:0% +the kernel to be correct for the sandbox +to actually hold and enforce + + align:start position:0% +to actually hold and enforce + + + align:start position:0% +to actually hold and enforce +isolation yeah as you get a lot more uh + + align:start position:0% +isolation yeah as you get a lot more uh + + + align:start position:0% +isolation yeah as you get a lot more uh +ways to use browsers and stuff like you + + align:start position:0% +ways to use browsers and stuff like you + + + align:start position:0% +ways to use browsers and stuff like you +have to deal with having some sort of + + align:start position:0% +have to deal with having some sort of + + + align:start position:0% +have to deal with having some sort of +thing and doing with it on like IOS and + + align:start position:0% +thing and doing with it on like IOS and + + + align:start position:0% +thing and doing with it on like IOS and +Android and all these other things + + align:start position:0% +Android and all these other things + + + align:start position:0% +Android and all these other things +access yeah so so actually another + + align:start position:0% +access yeah so so actually another + + + align:start position:0% +access yeah so so actually another +interesting consideration is that not + + align:start position:0% +interesting consideration is that not + + + align:start position:0% +interesting consideration is that not +only might the os's have bugs but + + align:start position:0% +only might the os's have bugs but + + + align:start position:0% +only might the os's have bugs but +actually the os's are incompatible with + + align:start position:0% +actually the os's are incompatible with + + + align:start position:0% +actually the os's are incompatible with +each other in some ways uh meaning that + + align:start position:0% +each other in some ways uh meaning that + + + align:start position:0% +each other in some ways uh meaning that +each OS has its own mechanis like right + + align:start position:0% +each OS has its own mechanis like right + + + align:start position:0% +each OS has its own mechanis like right +here well there's Unix there's capsicum + + align:start position:0% +here well there's Unix there's capsicum + + + align:start position:0% +here well there's Unix there's capsicum +there's setc comp and this is just the + + align:start position:0% +there's setc comp and this is just the + + + align:start position:0% +there's setc comp and this is just the +Unix variants there's Mac OS seat belt + + align:start position:0% +Unix variants there's Mac OS seat belt + + + align:start position:0% +Unix variants there's Mac OS seat belt +there's windows something else and and + + align:start position:0% +there's windows something else and and + + + align:start position:0% +there's windows something else and and +this just keeps going on and on so as a + + align:start position:0% +this just keeps going on and on so as a + + + align:start position:0% +this just keeps going on and on so as a +result every platform you will have to + + align:start position:0% +result every platform you will have to + + + align:start position:0% +result every platform you will have to +use a different isolation mechanism and + + align:start position:0% +use a different isolation mechanism and + + + align:start position:0% +use a different isolation mechanism and +the thing that actually bothers them is + + align:start position:0% +the thing that actually bothers them is + + + align:start position:0% +the thing that actually bothers them is +not so much they'll have to write + + align:start position:0% +not so much they'll have to write + + + align:start position:0% +not so much they'll have to write +different code for mac and windows and + + align:start position:0% +different code for mac and windows and + + + align:start position:0% +different code for mac and windows and +Linux but more that this impacts how you + + align:start position:0% +Linux but more that this impacts how you + + + align:start position:0% +Linux but more that this impacts how you +write the thing inside of the sandbox + + align:start position:0% +write the thing inside of the sandbox + + + align:start position:0% +write the thing inside of the sandbox +because a native client you actually + + align:start position:0% +because a native client you actually + + + align:start position:0% +because a native client you actually +write a piece of code and it runs the + + align:start position:0% +write a piece of code and it runs the + + + align:start position:0% +write a piece of code and it runs the +same way or it's the same piece of code + + align:start position:0% +same way or it's the same piece of code + + + align:start position:0% +same way or it's the same piece of code +that runs on Apple or Windows or Linux + + align:start position:0% +that runs on Apple or Windows or Linux + + + align:start position:0% +that runs on Apple or Windows or Linux +systems and if you use these isolation + + align:start position:0% +systems and if you use these isolation + + + align:start position:0% +systems and if you use these isolation +mechanisms they actually impose + + align:start position:0% +mechanisms they actually impose + + + align:start position:0% +mechanisms they actually impose +different restrictions on the program + + align:start position:0% +different restrictions on the program + + + align:start position:0% +different restrictions on the program +being sandboxed so you'll have to run + + align:start position:0% +being sandboxed so you'll have to run + + + align:start position:0% +being sandboxed so you'll have to run +right one program that's going to run + + align:start position:0% +right one program that's going to run + + + align:start position:0% +right one program that's going to run +inside of a Linux sandbox another + + align:start position:0% +inside of a Linux sandbox another + + + align:start position:0% +inside of a Linux sandbox another +program inside of a Windows sandbox and + + align:start position:0% +program inside of a Windows sandbox and + + + align:start position:0% +program inside of a Windows sandbox and +so on so this is actually not acceptable + + align:start position:0% +so on so this is actually not acceptable + + + align:start position:0% +so on so this is actually not acceptable +to them they don't want to deal with + + align:start position:0% +to them they don't want to deal with + + + align:start position:0% +to them they don't want to deal with +these kinds of + + align:start position:0% +these kinds of + + + align:start position:0% +these kinds of +problems so are there other + + align:start position:0% +problems so are there other + + + align:start position:0% +problems so are there other +considerations yeah presumably + + align:start position:0% +considerations yeah presumably + + + align:start position:0% +considerations yeah presumably +performance as well because if you if + + align:start position:0% +performance as well because if you if + + + align:start position:0% +performance as well because if you if +you use a uh capsum you need to Fork up + + align:start position:0% +you use a uh capsum you need to Fork up + + + align:start position:0% +you use a uh capsum you need to Fork up +a separate process for whatever is + + align:start position:0% +a separate process for whatever is + + + align:start position:0% +a separate process for whatever is +running inside the sandbox whereas here + + align:start position:0% +running inside the sandbox whereas here + + + align:start position:0% +running inside the sandbox whereas here +they can actually run it in the same in + + align:start position:0% +they can actually run it in the same in + + + align:start position:0% +they can actually run it in the same in +that's true yeah so potentially the + + align:start position:0% +that's true yeah so potentially the + + + align:start position:0% +that's true yeah so potentially the +approach they take the software fault + + align:start position:0% +approach they take the software fault + + + align:start position:0% +approach they take the software fault +isolation plan is actually highly + + align:start position:0% +isolation plan is actually highly + + + align:start position:0% +isolation plan is actually highly +performant and could outperform these uh + + align:start position:0% +performant and could outperform these uh + + + align:start position:0% +performant and could outperform these uh +sandboxes at the OS level it turns out + + align:start position:0% +sandboxes at the OS level it turns out + + + align:start position:0% +sandboxes at the OS level it turns out +that a native client actually use both + + align:start position:0% +that a native client actually use both + + + align:start position:0% +that a native client actually use both +their sandbox and the OS sandbox just + + align:start position:0% +their sandbox and the OS sandbox just + + + align:start position:0% +their sandbox and the OS sandbox just +for extra precaution for safety so they + + align:start position:0% +for extra precaution for safety so they + + + align:start position:0% +for extra precaution for safety so they +don't actually win on performance in + + align:start position:0% +don't actually win on performance in + + + align:start position:0% +don't actually win on performance in +their implementation but they could + + align:start position:0% +their implementation but they could + + + align:start position:0% +their implementation but they could +you're right yeah can there be some like + + align:start position:0% +you're right yeah can there be some like + + + align:start position:0% +you're right yeah can there be some like +control aspect to it they can control + + align:start position:0% +control aspect to it they can control + + + align:start position:0% +control aspect to it they can control +what happens in the browser but if they + + align:start position:0% +what happens in the browser but if they + + + align:start position:0% +what happens in the browser but if they +send C off to the client's machine into + + align:start position:0% +send C off to the client's machine into + + + align:start position:0% +send C off to the client's machine into +their OS sort of don't necessarily know + + align:start position:0% +their OS sort of don't necessarily know + + + align:start position:0% +their OS sort of don't necessarily know +what might be happening so I guess one + + align:start position:0% +what might be happening so I guess one + + + align:start position:0% +what might be happening so I guess one +maybe one way to think of that is that + + align:start position:0% +maybe one way to think of that is that + + + align:start position:0% +maybe one way to think of that is that +yeah the OS might have bugs so my OS + + align:start position:0% +yeah the OS might have bugs so my OS + + + align:start position:0% +yeah the OS might have bugs so my OS +might not do as good of a job at + + align:start position:0% +might not do as good of a job at + + + align:start position:0% +might not do as good of a job at +sandboxing it or maybe there's you know + + align:start position:0% +sandboxing it or maybe there's you know + + + align:start position:0% +sandboxing it or maybe there's you know +the interfaces are all different so you + + align:start position:0% +the interfaces are all different so you + + + align:start position:0% +the interfaces are all different so you +don't know what the O is going to expose + + align:start position:0% +don't know what the O is going to expose + + + align:start position:0% +don't know what the O is going to expose +yeah uh so doesn't like prevent the cach + + align:start position:0% +yeah uh so doesn't like prevent the cach + + + align:start position:0% +yeah uh so doesn't like prevent the cach +doing some bad things like there are a + + align:start position:0% +doing some bad things like there are a + + + align:start position:0% +doing some bad things like there are a +lot of cases of bad things that the code + + align:start position:0% +lot of cases of bad things that the code + + + align:start position:0% +lot of cases of bad things that the code +can just do like maybe you want to + + align:start position:0% +can just do like maybe you want to + + + align:start position:0% +can just do like maybe you want to +statically analyze it just as one to sit + + align:start position:0% +statically analyze it just as one to sit + + + align:start position:0% +statically analyze it just as one to sit +in a loop and then not allow that as a + + align:start position:0% +in a loop and then not allow that as a + + + align:start position:0% +in a loop and then not allow that as a +valid program so you could right so + + align:start position:0% +valid program so you could right so + + + align:start position:0% +valid program so you could right so +their approach is quite powerful in the + + align:start position:0% +their approach is quite powerful in the + + + align:start position:0% +their approach is quite powerful in the +sense that you could try to look for + + align:start position:0% +sense that you could try to look for + + + align:start position:0% +sense that you could try to look for +various kinds of problems in the code + + align:start position:0% +various kinds of problems in the code + + + align:start position:0% +various kinds of problems in the code +like maybe infinite Loops Etc it's hard + + align:start position:0% +like maybe infinite Loops Etc it's hard + + + align:start position:0% +like maybe infinite Loops Etc it's hard +to decide kind of like the halting + + align:start position:0% +to decide kind of like the halting + + + align:start position:0% +to decide kind of like the halting +problem whether it's going to have + + align:start position:0% +problem whether it's going to have + + + align:start position:0% +problem whether it's going to have +infinite Loops or not uh but in + + align:start position:0% +infinite Loops or not uh but in + + + align:start position:0% +infinite Loops or not uh but in +principle you might be able to catch + + align:start position:0% +principle you might be able to catch + + + align:start position:0% +principle you might be able to catch +some problems um I think one actually + + align:start position:0% +some problems um I think one actually + + + align:start position:0% +some problems um I think one actually +interesting example that I almost didn't + + align:start position:0% +interesting example that I almost didn't + + + align:start position:0% +interesting example that I almost didn't +realize sort of existed before reading + + align:start position:0% +realize sort of existed before reading + + + align:start position:0% +realize sort of existed before reading +this paper is these guys are worried + + align:start position:0% +this paper is these guys are worried + + + align:start position:0% +this paper is these guys are worried +about Hardware bugs as well + + align:start position:0% +about Hardware bugs as well + + + align:start position:0% +about Hardware bugs as well +that not only are they worried that the + + align:start position:0% +that not only are they worried that the + + + align:start position:0% +that not only are they worried that the +operating system might have + + align:start position:0% +operating system might have + + + align:start position:0% +operating system might have +vulnerabilities that the malicious code + + align:start position:0% +vulnerabilities that the malicious code + + + align:start position:0% +vulnerabilities that the malicious code +will exploit but also that the processor + + align:start position:0% +will exploit but also that the processor + + + align:start position:0% +will exploit but also that the processor +itself has some instructions that will + + align:start position:0% +itself has some instructions that will + + + align:start position:0% +itself has some instructions that will +hang it or it'll reboot your machine and + + align:start position:0% +hang it or it'll reboot your machine and + + + align:start position:0% +hang it or it'll reboot your machine and +in principle your Hardware shouldn't + + align:start position:0% +in principle your Hardware shouldn't + + + align:start position:0% +in principle your Hardware shouldn't +have such bugs because the operating + + align:start position:0% +have such bugs because the operating + + + align:start position:0% +have such bugs because the operating +system relies on the hardware to trap + + align:start position:0% +system relies on the hardware to trap + + + align:start position:0% +system relies on the hardware to trap +into the kernel if there's anything bad + + align:start position:0% +into the kernel if there's anything bad + + + align:start position:0% +into the kernel if there's anything bad +executing in user mode so that the + + align:start position:0% +executing in user mode so that the + + + align:start position:0% +executing in user mode so that the +operating system can take care of it but + + align:start position:0% +operating system can take care of it but + + + align:start position:0% +operating system can take care of it but +experimentally it turns out that + + align:start position:0% +experimentally it turns out that + + + align:start position:0% +experimentally it turns out that +processors are so complicated they do + + align:start position:0% +processors are so complicated they do + + + align:start position:0% +processors are so complicated they do +have bugs and these guys actually say + + align:start position:0% +have bugs and these guys actually say + + + align:start position:0% +have bugs and these guys actually say +well we actually found some evidence + + align:start position:0% +well we actually found some evidence + + + align:start position:0% +well we actually found some evidence +that this happens if you have a some + + align:start position:0% +that this happens if you have a some + + + align:start position:0% +that this happens if you have a some +complicated instruction the CPU wasn't + + align:start position:0% +complicated instruction the CPU wasn't + + + align:start position:0% +complicated instruction the CPU wasn't +expecting the CPU will actually halt + + align:start position:0% +expecting the CPU will actually halt + + + align:start position:0% +expecting the CPU will actually halt +instead of trapping to the kernel so + + align:start position:0% +instead of trapping to the kernel so + + + align:start position:0% +instead of trapping to the kernel so +that seems bad but I guess it's not as + + align:start position:0% +that seems bad but I guess it's not as + + + align:start position:0% +that seems bad but I guess it's not as +disastrous if I'm sort of only running + + align:start position:0% +disastrous if I'm sort of only running + + + align:start position:0% +disastrous if I'm sort of only running +reasonable things on my laptop but it is + + align:start position:0% +reasonable things on my laptop but it is + + + align:start position:0% +reasonable things on my laptop but it is +bad if you visit some web page and your + + align:start position:0% +bad if you visit some web page and your + + + align:start position:0% +bad if you visit some web page and your +computer hangs so they want basically a + + align:start position:0% +computer hangs so they want basically a + + + align:start position:0% +computer hangs so they want basically a +stronger level of protection for these + + align:start position:0% +stronger level of protection for these + + + align:start position:0% +stronger level of protection for these +native client modules than what you + + align:start position:0% +native client modules than what you + + + align:start position:0% +native client modules than what you +would get out of + + align:start position:0% +would get out of + + + align:start position:0% +would get out of +sort of os level isolation even from a + + align:start position:0% +sort of os level isolation even from a + + + align:start position:0% +sort of os level isolation even from a +hardware B bug standpoint so that's + + align:start position:0% +hardware B bug standpoint so that's + + + align:start position:0% +hardware B bug standpoint so that's +actually pretty cool they're like really + + align:start position:0% +actually pretty cool they're like really + + + align:start position:0% +actually pretty cool they're like really +paranoid about uh security uh including + + align:start position:0% +paranoid about uh security uh including + + + align:start position:0% +paranoid about uh security uh including +even Hardware uh + + align:start position:0% +even Hardware uh + + + align:start position:0% +even Hardware uh +problems all right so any questions + + align:start position:0% +problems all right so any questions + + + align:start position:0% +problems all right so any questions +about all these alternativ how that + + align:start position:0% +about all these alternativ how that + + + align:start position:0% +about all these alternativ how that +works or why these guys are not excited + + align:start position:0% +works or why these guys are not excited + + + align:start position:0% +works or why these guys are not excited +about + + align:start position:0% +about + + + align:start position:0% +about +them make + + align:start position:0% +them make + + + align:start position:0% +them make +sense all right so I guess let's uh try + + align:start position:0% +sense all right so I guess let's uh try + + + align:start position:0% +sense all right so I guess let's uh try +to look at now how Native client does + + align:start position:0% +to look at now how Native client does + + + align:start position:0% +to look at now how Native client does +actually uh decide to s box processes so + + align:start position:0% +actually uh decide to s box processes so + + + align:start position:0% +actually uh decide to s box processes so +let me pull up these + + align:start position:0% +let me pull up these + + + align:start position:0% +let me pull up these +boards so native client takes this + + align:start position:0% +boards so native client takes this + + + align:start position:0% +boards so native client takes this +different approach that's uh in general + + align:start position:0% +different approach that's uh in general + + + align:start position:0% +different approach that's uh in general +called software fault + + align:start position:0% + + + + align:start position:0% + +isolation and the plan is to actually + + align:start position:0% +isolation and the plan is to actually + + + align:start position:0% +isolation and the plan is to actually +not rely on the operating system or + + align:start position:0% +not rely on the operating system or + + + align:start position:0% +not rely on the operating system or +Hardware to check things at runtime but + + align:start position:0% +Hardware to check things at runtime but + + + align:start position:0% +Hardware to check things at runtime but +instead to somehow look at the + + align:start position:0% +instead to somehow look at the + + + align:start position:0% +instead to somehow look at the +instructions ahead of time and decide + + align:start position:0% +instructions ahead of time and decide + + + align:start position:0% +instructions ahead of time and decide +that they're always going to be safe to + + align:start position:0% +that they're always going to be safe to + + + align:start position:0% +that they're always going to be safe to +execute so actually you actually look at + + align:start position:0% +execute so actually you actually look at + + + align:start position:0% +execute so actually you actually look at +the binary and you check all the + + align:start position:0% +the binary and you check all the + + + align:start position:0% +the binary and you check all the +possible instructions to see whether + + align:start position:0% +possible instructions to see whether + + + align:start position:0% +possible instructions to see whether +there're going to be safe instructions + + align:start position:0% +there're going to be safe instructions + + + align:start position:0% +there're going to be safe instructions +or unsafe instructions and once you've + + align:start position:0% +or unsafe instructions and once you've + + + align:start position:0% +or unsafe instructions and once you've +decided that it's all going to be safe + + align:start position:0% +decided that it's all going to be safe + + + align:start position:0% +decided that it's all going to be safe +you can just jump in and start executing + + align:start position:0% +you can just jump in and start executing + + + align:start position:0% +you can just jump in and start executing +because you know it's all composed of + + align:start position:0% +because you know it's all composed of + + + align:start position:0% +because you know it's all composed of +safe things so it cannot go wrong so + + align:start position:0% +safe things so it cannot go wrong so + + + align:start position:0% +safe things so it cannot go wrong so +we'll talk about exactly what this means + + align:start position:0% +we'll talk about exactly what this means + + + align:start position:0% +we'll talk about exactly what this means +but roughly what they're going to do is + + align:start position:0% +but roughly what they're going to do is + + + align:start position:0% +but roughly what they're going to do is +they're going to look at pretty much + + align:start position:0% +they're going to look at pretty much + + + align:start position:0% +they're going to look at pretty much +every instruction in the binary code + + align:start position:0% +every instruction in the binary code + + + align:start position:0% +every instruction in the binary code +that is served up to the browser and + + align:start position:0% +that is served up to the browser and + + + align:start position:0% +that is served up to the browser and +they're going to decide that particular + + align:start position:0% +they're going to decide that particular + + + align:start position:0% +they're going to decide that particular +instructions are going to be safe or + + align:start position:0% +instructions are going to be safe or + + + align:start position:0% +instructions are going to be safe or +unsafe so what do they do for safe + + align:start position:0% +unsafe so what do they do for safe + + + align:start position:0% +unsafe so what do they do for safe +instructions well they're they're just + + align:start position:0% +instructions well they're they're just + + + align:start position:0% +instructions well they're they're just +going to allow them uh what's an example + + align:start position:0% +going to allow them uh what's an example + + + align:start position:0% +going to allow them uh what's an example +of a safe instruction what are they + + align:start position:0% +of a safe instruction what are they + + + align:start position:0% +of a safe instruction what are they +thinking of that doesn't need any extra + + align:start position:0% +thinking of that doesn't need any extra + + + align:start position:0% +thinking of that doesn't need any extra +checks or protection + + align:start position:0% +checks or protection + + + align:start position:0% +checks or protection +Etc yeah so like any kind of ALU + + align:start position:0% +Etc yeah so like any kind of ALU + + + align:start position:0% +Etc yeah so like any kind of ALU +operation basically yeah MTH + + align:start position:0% +operation basically yeah MTH + + + align:start position:0% +operation basically yeah MTH +presumably + + align:start position:0% +presumably + + + align:start position:0% +presumably +moves between registers uh and so on so + + align:start position:0% +moves between registers uh and so on so + + + align:start position:0% +moves between registers uh and so on so +this doesn't actually affect the + + align:start position:0% +this doesn't actually affect the + + + align:start position:0% +this doesn't actually affect the +security of the system as far as their + + align:start position:0% +security of the system as far as their + + + align:start position:0% +security of the system as far as their +concern because all they really care + + align:start position:0% +concern because all they really care + + + align:start position:0% +concern because all they really care +about is things like memory safety where + + align:start position:0% +about is things like memory safety where + + + align:start position:0% +about is things like memory safety where +what code you execute and so on um so as + + align:start position:0% +what code you execute and so on um so as + + + align:start position:0% +what code you execute and so on um so as +long as you're just Computing on some + + align:start position:0% +long as you're just Computing on some + + + align:start position:0% +long as you're just Computing on some +stuff and registers they don't really + + align:start position:0% +stuff and registers they don't really + + + align:start position:0% +stuff and registers they don't really +care it's not going to affect the rest + + align:start position:0% +care it's not going to affect the rest + + + align:start position:0% +care it's not going to affect the rest +of the + + align:start position:0% +of the + + + align:start position:0% +of the +browser so what about unsafe operations + + align:start position:0% +browser so what about unsafe operations + + + align:start position:0% +browser so what about unsafe operations +I guess these are things that they might + + align:start position:0% +I guess these are things that they might + + + align:start position:0% +I guess these are things that they might +care much more about so this is anything + + align:start position:0% +care much more about so this is anything + + + align:start position:0% +care much more about so this is anything +that maybe does a memory access or maybe + + align:start position:0% +that maybe does a memory access or maybe + + + align:start position:0% +that maybe does a memory access or maybe +some privileged + + align:start position:0% +some privileged + + + align:start position:0% +some privileged +instruction maybe invoking a system call + + align:start position:0% +instruction maybe invoking a system call + + + align:start position:0% +instruction maybe invoking a system call +on this machine um maybe trying to jump + + align:start position:0% +on this machine um maybe trying to jump + + + align:start position:0% +on this machine um maybe trying to jump +out of the sandbox who knows what so for + + align:start position:0% +out of the sandbox who knows what so for + + + align:start position:0% +out of the sandbox who knows what so for +these kinds of instructions they're + + align:start position:0% +these kinds of instructions they're + + + align:start position:0% +these kinds of instructions they're +going to do one of two things if the + + align:start position:0% +going to do one of two things if the + + + align:start position:0% +going to do one of two things if the +instruction actually is necessary for + + align:start position:0% +instruction actually is necessary for + + + align:start position:0% +instruction actually is necessary for +the application to do its job like + + align:start position:0% +the application to do its job like + + + align:start position:0% +the application to do its job like +accessing memory seems important then + + align:start position:0% +accessing memory seems important then + + + align:start position:0% +accessing memory seems important then +they're going to somehow make sure that + + align:start position:0% +they're going to somehow make sure that + + + align:start position:0% +they're going to somehow make sure that +they can execute this unsafe instruction + + align:start position:0% +they can execute this unsafe instruction + + + align:start position:0% +they can execute this unsafe instruction +safely or if you're jumping around for + + align:start position:0% +safely or if you're jumping around for + + + align:start position:0% +safely or if you're jumping around for +example in the program's address space + + align:start position:0% +example in the program's address space + + + align:start position:0% +example in the program's address space +then what they're going to do is somehow + + align:start position:0% +then what they're going to do is somehow + + + align:start position:0% +then what they're going to do is somehow +instrument the + + align:start position:0% +instrument the + + + align:start position:0% +instrument the +instruction and what instrumenting the + + align:start position:0% +instruction and what instrumenting the + + + align:start position:0% +instruction and what instrumenting the +instruction means is that you used to + + align:start position:0% +instruction means is that you used to + + + align:start position:0% +instruction means is that you used to +have one unsafe instruction that + + align:start position:0% +have one unsafe instruction that + + + align:start position:0% +have one unsafe instruction that +sometimes does good things that the + + align:start position:0% +sometimes does good things that the + + + align:start position:0% +sometimes does good things that the +application might actually want to do + + align:start position:0% +application might actually want to do + + + align:start position:0% +application might actually want to do +legitimately and sometimes that + + align:start position:0% +legitimately and sometimes that + + + align:start position:0% +legitimately and sometimes that +instruction could do bad things so what + + align:start position:0% +instruction could do bad things so what + + + align:start position:0% +instruction could do bad things so what +instrumenting it means is that you add + + align:start position:0% +instrumenting it means is that you add + + + align:start position:0% +instrumenting it means is that you add +some extra instructions before it that + + align:start position:0% +some extra instructions before it that + + + align:start position:0% +some extra instructions before it that +will check or enforce that only good + + align:start position:0% +will check or enforce that only good + + + align:start position:0% +will check or enforce that only good +things are going to happen with that + + align:start position:0% +things are going to happen with that + + + align:start position:0% +things are going to happen with that +instruction so for example if you're + + align:start position:0% +instruction so for example if you're + + + align:start position:0% +instruction so for example if you're +accessing a memory location what you + + align:start position:0% +accessing a memory location what you + + + align:start position:0% +accessing a memory location what you +could do turns out they don't do it for + + align:start position:0% +could do turns out they don't do it for + + + align:start position:0% +could do turns out they don't do it for +performance reasons but one way to + + align:start position:0% +performance reasons but one way to + + + align:start position:0% +performance reasons but one way to +instrument A Memory access would be to + + align:start position:0% +instrument A Memory access would be to + + + align:start position:0% +instrument A Memory access would be to +put some checks like an if statement + + align:start position:0% +put some checks like an if statement + + + align:start position:0% +put some checks like an if statement +before the instruction saying well is + + align:start position:0% +before the instruction saying well is + + + align:start position:0% +before the instruction saying well is +this address you're accessing in range + + align:start position:0% +this address you're accessing in range + + + align:start position:0% +this address you're accessing in range +of what's allowed for this module and if + + align:start position:0% +of what's allowed for this module and if + + + align:start position:0% +of what's allowed for this module and if +so do they access otherwise exit so that + + align:start position:0% +so do they access otherwise exit so that + + + align:start position:0% +so do they access otherwise exit so that +would instrument an instruction and that + + align:start position:0% +would instrument an instruction and that + + + align:start position:0% +would instrument an instruction and that +would turn an unsafe instruction into + + align:start position:0% +would turn an unsafe instruction into + + + align:start position:0% +would turn an unsafe instruction into +one that's always safe to execute + + align:start position:0% +one that's always safe to execute + + + align:start position:0% +one that's always safe to execute +because there is always that check in + + align:start position:0% +because there is always that check in + + + align:start position:0% +because there is always that check in +front of it so does that make sense this + + align:start position:0% +front of it so does that make sense this + + + align:start position:0% +front of it so does that make sense this +is their sort of big idea for running + + align:start position:0% +is their sort of big idea for running + + + align:start position:0% +is their sort of big idea for running +this enforcing safety without support + + align:start position:0% +this enforcing safety without support + + + align:start position:0% +this enforcing safety without support +from the operating system at some + + align:start position:0% +from the operating system at some + + + align:start position:0% +from the operating system at some +level and I guess for other unsafe + + align:start position:0% +level and I guess for other unsafe + + + align:start position:0% +level and I guess for other unsafe +instructions they don't instrument all + + align:start position:0% +instructions they don't instrument all + + + align:start position:0% +instructions they don't instrument all +of them some of them they actually + + align:start position:0% +of them some of them they actually + + + align:start position:0% +of them some of them they actually +prohibit if they believe that this is an + + align:start position:0% +prohibit if they believe that this is an + + + align:start position:0% +prohibit if they believe that this is an +instruction that's not really necessary + + align:start position:0% +instruction that's not really necessary + + + align:start position:0% +instruction that's not really necessary +during normal operation and if an + + align:start position:0% +during normal operation and if an + + + align:start position:0% +during normal operation and if an +application tries to run it there we + + align:start position:0% +application tries to run it there we + + + align:start position:0% +application tries to run it there we +should just kill the application or not + + align:start position:0% +should just kill the application or not + + + align:start position:0% +should just kill the application or not +allow it to run in the first + + align:start position:0% +allow it to run in the first + + + align:start position:0% +allow it to run in the first +place makes sense so this is their sort + + align:start position:0% +place makes sense so this is their sort + + + align:start position:0% +place makes sense so this is their sort +of big plan for software fault isolation + + align:start position:0% +of big plan for software fault isolation + + + align:start position:0% +of big plan for software fault isolation +and once you've checked the + + align:start position:0% +and once you've checked the + + + align:start position:0% +and once you've checked the +application's binary and It All Passes + + align:start position:0% +application's binary and It All Passes + + + align:start position:0% +application's binary and It All Passes +and everything seems to be properly + + align:start position:0% +and everything seems to be properly + + + align:start position:0% +and everything seems to be properly +instrumented then you can just run the + + align:start position:0% +instrumented then you can just run the + + + align:start position:0% +instrumented then you can just run the +program and off it goes and by + + align:start position:0% +program and off it goes and by + + + align:start position:0% +program and off it goes and by +definition almost it'll not do bad + + align:start position:0% +definition almost it'll not do bad + + + align:start position:0% +definition almost it'll not do bad +things if we do all these checks and + + align:start position:0% +things if we do all these checks and + + + align:start position:0% +things if we do all these checks and +instrumentations + + align:start position:0% +instrumentations + + + align:start position:0% +instrumentations +right and I guess there's one more part + + align:start position:0% +right and I guess there's one more part + + + align:start position:0% +right and I guess there's one more part +to the software fault isolation story + + align:start position:0% +to the software fault isolation story + + + align:start position:0% +to the software fault isolation story +which is that once you've made sure that + + align:start position:0% +which is that once you've made sure that + + + align:start position:0% +which is that once you've made sure that +everything is safe then it can't + + align:start position:0% +everything is safe then it can't + + + align:start position:0% +everything is safe then it can't +actually do anything terribly + + align:start position:0% +actually do anything terribly + + + align:start position:0% +actually do anything terribly +interesting other than compute stuff in + + align:start position:0% +interesting other than compute stuff in + + + align:start position:0% +interesting other than compute stuff in +its own little memory so it can't access + + align:start position:0% +its own little memory so it can't access + + + align:start position:0% +its own little memory so it can't access +the network can't access the disc can't + + align:start position:0% +the network can't access the disc can't + + + align:start position:0% +the network can't access the disc can't +access your browser display keyboard + + align:start position:0% +access your browser display keyboard + + + align:start position:0% +access your browser display keyboard +almost anything so in pretty much every + + align:start position:0% +almost anything so in pretty much every + + + align:start position:0% +almost anything so in pretty much every +software fault isolation story there's + + align:start position:0% +software fault isolation story there's + + + align:start position:0% +software fault isolation story there's +actually also some trusted service + + align:start position:0% + + + + align:start position:0% + +runtime and this trusted runtime is + + align:start position:0% +runtime and this trusted runtime is + + + align:start position:0% +runtime and this trusted runtime is +going to not be subject to these checks + + align:start position:0% +going to not be subject to these checks + + + align:start position:0% +going to not be subject to these checks +on its instructions so the trusted + + align:start position:0% +on its instructions so the trusted + + + align:start position:0% +on its instructions so the trusted +runtime could actually do all these + + align:start position:0% +runtime could actually do all these + + + align:start position:0% +runtime could actually do all these +potentially unsafe things but the + + align:start position:0% +potentially unsafe things but the + + + align:start position:0% +potentially unsafe things but the +trusted runtime is written by Google so + + align:start position:0% +trusted runtime is written by Google so + + + align:start position:0% +trusted runtime is written by Google so +hopefully they get it right and it's + + align:start position:0% +hopefully they get it right and it's + + + align:start position:0% +hopefully they get it right and it's +going to implement all the functions + + align:start position:0% +going to implement all the functions + + + align:start position:0% +going to implement all the functions +that + + align:start position:0% +that + + + align:start position:0% +that +Google's native client team believes are + + align:start position:0% +Google's native client team believes are + + + align:start position:0% +Google's native client team believes are +okay to allow for these modules so these + + align:start position:0% +okay to allow for these modules so these + + + align:start position:0% +okay to allow for these modules so these +are going to be things like maybe + + align:start position:0% +are going to be things like maybe + + + align:start position:0% +are going to be things like maybe +allocating memory maybe creating a + + align:start position:0% +allocating memory maybe creating a + + + align:start position:0% +allocating memory maybe creating a +thread maybe communicating with the + + align:start position:0% +thread maybe communicating with the + + + align:start position:0% +thread maybe communicating with the +browser as we saw so some sort of a + + align:start position:0% +browser as we saw so some sort of a + + + align:start position:0% +browser as we saw so some sort of a +message passing + + align:start position:0% +message passing + + + align:start position:0% +message passing +system Etc and the way it's going to be + + align:start position:0% +system Etc and the way it's going to be + + + align:start position:0% +system Etc and the way it's going to be +exposed to this isolated module is + + align:start position:0% +exposed to this isolated module is + + + align:start position:0% +exposed to this isolated module is +through + + align:start position:0% +through + + + align:start position:0% +through +certain presumably um special jumps or + + align:start position:0% +certain presumably um special jumps or + + + align:start position:0% +certain presumably um special jumps or +operations that the uh module is going + + align:start position:0% +operations that the uh module is going + + + align:start position:0% +operations that the uh module is going +to perform to transition control into + + align:start position:0% +to perform to transition control into + + + align:start position:0% +to perform to transition control into +this trusted runtime but hopefully in a + + align:start position:0% +this trusted runtime but hopefully in a + + + align:start position:0% +this trusted runtime but hopefully in a +very predictable way so question I'm + + align:start position:0% +very predictable way so question I'm + + + align:start position:0% +very predictable way so question I'm +just curious um so do you have to design + + align:start position:0% +just curious um so do you have to design + + + align:start position:0% +just curious um so do you have to design +this application um knowing that it's + + align:start position:0% +this application um knowing that it's + + + align:start position:0% +this application um knowing that it's +going to be sent to the NC module or is + + align:start position:0% +going to be sent to the NC module or is + + + align:start position:0% +going to be sent to the NC module or is +it like change the code so that it'll + + align:start position:0% +it like change the code so that it'll + + + align:start position:0% +it like change the code so that it'll +make necessary call to the + + align:start position:0% +make necessary call to the + + + align:start position:0% +make necessary call to the +service so I think if you're taking an + + align:start position:0% +service so I think if you're taking an + + + align:start position:0% +service so I think if you're taking an +if you're building an application you do + + align:start position:0% +if you're building an application you do + + + align:start position:0% +if you're building an application you do +have to be sort of aware that it's going + + align:start position:0% +have to be sort of aware that it's going + + + align:start position:0% +have to be sort of aware that it's going +to be running inside of native client um + + align:start position:0% +to be running inside of native client um + + + align:start position:0% +to be running inside of native client um +so some function calls like Malo or + + align:start position:0% +so some function calls like Malo or + + + align:start position:0% +so some function calls like Malo or +pthread create I think they just + + align:start position:0% +pthread create I think they just + + + align:start position:0% +pthread create I think they just +transparently replace with calls to + + align:start position:0% +transparently replace with calls to + + + align:start position:0% +transparently replace with calls to +their trusted runtime but if you do + + align:start position:0% +their trusted runtime but if you do + + + align:start position:0% +their trusted runtime but if you do +anything like opening a file by path + + align:start position:0% +anything like opening a file by path + + + align:start position:0% +anything like opening a file by path +name or anything else that sort of you + + align:start position:0% +name or anything else that sort of you + + + align:start position:0% +name or anything else that sort of you +would expect to do on a Unix machine + + align:start position:0% +would expect to do on a Unix machine + + + align:start position:0% +would expect to do on a Unix machine +that You' probably have to replace with + + align:start position:0% +that You' probably have to replace with + + + align:start position:0% +that You' probably have to replace with +something else and you'd probably want + + align:start position:0% +something else and you'd probably want + + + align:start position:0% +something else and you'd probably want +to structure your thing to interact at + + align:start position:0% +to structure your thing to interact at + + + align:start position:0% +to structure your thing to interact at +least a little bit with your JavaScript + + align:start position:0% +least a little bit with your JavaScript + + + align:start position:0% +least a little bit with your JavaScript +or web page in some way and that you + + align:start position:0% +or web page in some way and that you + + + align:start position:0% +or web page in some way and that you +would have to do by explicitly doing + + align:start position:0% +would have to do by explicitly doing + + + align:start position:0% +would have to do by explicitly doing +some message passing or rpcs into the + + align:start position:0% +some message passing or rpcs into the + + + align:start position:0% +some message passing or rpcs into the +JavaScript part so that you would have + + align:start position:0% +JavaScript part so that you would have + + + align:start position:0% +JavaScript part so that you would have +to probably change uh so there's some so + + align:start position:0% +to probably change uh so there's some so + + + align:start position:0% +to probably change uh so there's some so +it's not like you can run an arbitrary + + align:start position:0% +it's not like you can run an arbitrary + + + align:start position:0% +it's not like you can run an arbitrary +Unix program in there and you'll just + + align:start position:0% +Unix program in there and you'll just + + + align:start position:0% +Unix program in there and you'll just +sort of get a shell and you can run + + align:start position:0% +sort of get a shell and you can run + + + align:start position:0% +sort of get a shell and you can run +commands all of a sudden probably if you + + align:start position:0% +commands all of a sudden probably if you + + + align:start position:0% +commands all of a sudden probably if you +Tred hard maybe you could create such an + + align:start position:0% +Tred hard maybe you could create such an + + + align:start position:0% +Tred hard maybe you could create such an +environment uh but by default you + + align:start position:0% +environment uh but by default you + + + align:start position:0% +environment uh but by default you +probably have to make it operate inside + + align:start position:0% +probably have to make it operate inside + + + align:start position:0% +probably have to make it operate inside +of this web page and interact with it in + + align:start position:0% +of this web page and interact with it in + + + align:start position:0% +of this web page and interact with it in +some way make + + align:start position:0% +some way make + + + align:start position:0% +some way make +sense all right + + align:start position:0% +sense all right + + + align:start position:0% +sense all right +okay so so that's the overall plan for + + align:start position:0% +okay so so that's the overall plan for + + + align:start position:0% +okay so so that's the overall plan for +software of isolation so I guess let's + + align:start position:0% +software of isolation so I guess let's + + + align:start position:0% +software of isolation so I guess let's +look at actually what safety means in + + align:start position:0% +look at actually what safety means in + + + align:start position:0% +look at actually what safety means in +their case for Native client so we + + align:start position:0% +their case for Native client so we + + + align:start position:0% +their case for Native client so we +talked Loosely about this notion of safe + + align:start position:0% +talked Loosely about this notion of safe + + + align:start position:0% +talked Loosely about this notion of safe +instructions unsafe instructions what do + + align:start position:0% +instructions unsafe instructions what do + + + align:start position:0% +instructions unsafe instructions what do +they actually care about here so as far + + align:start position:0% +they actually care about here so as far + + + align:start position:0% +they actually care about here so as far +as I can tell for a native client safety + + align:start position:0% +as I can tell for a native client safety + + + align:start position:0% +as I can tell for a native client safety +uh basically means two things one is + + align:start position:0% +uh basically means two things one is + + + align:start position:0% +uh basically means two things one is +that there's no disallowed + + align:start position:0% +that there's no disallowed + + + align:start position:0% +that there's no disallowed +instructions that can execute + + align:start position:0% + + + + align:start position:0% + +and uh these disallowed instructions are + + align:start position:0% +and uh these disallowed instructions are + + + align:start position:0% +and uh these disallowed instructions are +things like maybe system calls or + + align:start position:0% +things like maybe system calls or + + + align:start position:0% +things like maybe system calls or +triggering an interupt which is another + + align:start position:0% +triggering an interupt which is another + + + align:start position:0% +triggering an interupt which is another +mechanism on x86 to jump into the kernel + + align:start position:0% +mechanism on x86 to jump into the kernel + + + align:start position:0% +mechanism on x86 to jump into the kernel +and invoke a system call uh and probably + + align:start position:0% +and invoke a system call uh and probably + + + align:start position:0% +and invoke a system call uh and probably +other privileged instructions that would + + align:start position:0% +other privileged instructions that would + + + align:start position:0% +other privileged instructions that would +allow you to escape out of the sandbox + + align:start position:0% +allow you to escape out of the sandbox + + + align:start position:0% +allow you to escape out of the sandbox +so we'll look a little bit more later at + + align:start position:0% +so we'll look a little bit more later at + + + align:start position:0% +so we'll look a little bit more later at +what instructions could actually let you + + align:start position:0% +what instructions could actually let you + + + align:start position:0% +what instructions could actually let you +jump out of a + + align:start position:0% +jump out of a + + + align:start position:0% +jump out of a +Sandbox and in addition to this no + + align:start position:0% +Sandbox and in addition to this no + + + align:start position:0% +Sandbox and in addition to this no +disallowed instructions rule they also + + align:start position:0% +disallowed instructions rule they also + + + align:start position:0% +disallowed instructions rule they also +um want to make make sure that all code + + align:start position:0% +um want to make make sure that all code + + + align:start position:0% +um want to make make sure that all code +and data + + align:start position:0% +and data + + + align:start position:0% +and data +accesses are in + + align:start position:0% +accesses are in + + + align:start position:0% +accesses are in +bounds for the + + align:start position:0% + + + + align:start position:0% + +module so what this means is that they + + align:start position:0% +module so what this means is that they + + + align:start position:0% +module so what this means is that they +actually dedicate a particular part of + + align:start position:0% +actually dedicate a particular part of + + + align:start position:0% +actually dedicate a particular part of +the program's address space specifically + + align:start position:0% +the program's address space specifically + + + align:start position:0% +the program's address space specifically +it goes from zero up to 256 Megs in the + + align:start position:0% +it goes from zero up to 256 Megs in the + + + align:start position:0% +it goes from zero up to 256 Megs in the +process and everything that this + + align:start position:0% +process and everything that this + + + align:start position:0% +process and everything that this +untrusted module does has to refer to + + align:start position:0% +untrusted module does has to refer to + + + align:start position:0% +untrusted module does has to refer to +locations within this chunk of memory in + + align:start position:0% +locations within this chunk of memory in + + + align:start position:0% +locations within this chunk of memory in +the + + align:start position:0% +the + + + align:start position:0% +the +program all right so just a double check + + align:start position:0% +program all right so just a double check + + + align:start position:0% +program all right so just a double check +so why do they want to disallow these + + align:start position:0% +so why do they want to disallow these + + + align:start position:0% +so why do they want to disallow these +instructions so what if they fail to + + align:start position:0% +instructions so what if they fail to + + + align:start position:0% +instructions so what if they fail to +disallow the + + align:start position:0% + + + + align:start position:0% + +instructions yeah module can make a CIS + + align:start position:0% +instructions yeah module can make a CIS + + + align:start position:0% +instructions yeah module can make a CIS +right so that's yeah fairly + + align:start position:0% +right so that's yeah fairly + + + align:start position:0% +right so that's yeah fairly +straightforward exactly yeah so you + + align:start position:0% +straightforward exactly yeah so you + + + align:start position:0% +straightforward exactly yeah so you +could just directly reboot the machine + + align:start position:0% +could just directly reboot the machine + + + align:start position:0% +could just directly reboot the machine +or open your home directory and + + align:start position:0% +or open your home directory and + + + align:start position:0% +or open your home directory and +enumerate all the files and do all these + + align:start position:0% +enumerate all the files and do all these + + + align:start position:0% +enumerate all the files and do all these +things so that seems like a good thing + + align:start position:0% +things so that seems like a good thing + + + align:start position:0% +things so that seems like a good thing +to do why do they care about this plan + + align:start position:0% +to do why do they care about this plan + + + align:start position:0% +to do why do they care about this plan +like isolating the code on data to only + + align:start position:0% +like isolating the code on data to only + + + align:start position:0% +like isolating the code on data to only +access these low addresses so what goes + + align:start position:0% +access these low addresses so what goes + + + align:start position:0% +access these low addresses so what goes +wrong if they fail to do + + align:start position:0% + + + + align:start position:0% + +that does anything yeah then they can + + align:start position:0% +that does anything yeah then they can + + + align:start position:0% +that does anything yeah then they can +start accessing interrupting memory that + + align:start position:0% +start accessing interrupting memory that + + + align:start position:0% +start accessing interrupting memory that +doesn't belong that module like on your + + align:start position:0% +doesn't belong that module like on your + + + align:start position:0% +doesn't belong that module like on your +computer we don't care if they ruin + + align:start position:0% +computer we don't care if they ruin + + + align:start position:0% +computer we don't care if they ruin +their own program and it crashes that's + + align:start position:0% +their own program and it crashes that's + + + align:start position:0% +their own program and it crashes that's +fine as long as it's not going to crash + + align:start position:0% +fine as long as it's not going to crash + + + align:start position:0% +fine as long as it's not going to crash +the computer that's running yeah so in + + align:start position:0% +the computer that's running yeah so in + + + align:start position:0% +the computer that's running yeah so in +some sense uh that's true but and in + + align:start position:0% +some sense uh that's true but and in + + + align:start position:0% +some sense uh that's true but and in +their case they actually run the thing + + align:start position:0% +their case they actually run the thing + + + align:start position:0% +their case they actually run the thing +in a separate process so in in theory + + align:start position:0% +in a separate process so in in theory + + + align:start position:0% +in a separate process so in in theory +this would only crash that extra process + + align:start position:0% +this would only crash that extra process + + + align:start position:0% +this would only crash that extra process +um I think that I guess what they're + + align:start position:0% +um I think that I guess what they're + + + align:start position:0% +um I think that I guess what they're +really worried about is that this is a + + align:start position:0% +really worried about is that this is a + + + align:start position:0% +really worried about is that this is a +necessary condition to ensure there's no + + align:start position:0% +necessary condition to ensure there's no + + + align:start position:0% +necessary condition to ensure there's no +disallowed instructions in some way + + align:start position:0% +disallowed instructions in some way + + + align:start position:0% +disallowed instructions in some way +because there's other stuff like this + + align:start position:0% +because there's other stuff like this + + + align:start position:0% +because there's other stuff like this +trusted runtime in your process so if + + align:start position:0% +trusted runtime in your process so if + + + align:start position:0% +trusted runtime in your process so if +what you really care about is not + + align:start position:0% +what you really care about is not + + + align:start position:0% +what you really care about is not +corrupting the rest of your computer + + align:start position:0% +corrupting the rest of your computer + + + align:start position:0% +corrupting the rest of your computer +then if the untrusted module could + + align:start position:0% +then if the untrusted module could + + + align:start position:0% +then if the untrusted module could +arbitrarily jump into this trusted + + align:start position:0% +arbitrarily jump into this trusted + + + align:start position:0% +arbitrarily jump into this trusted +service runtime and do anything that the + + align:start position:0% +service runtime and do anything that the + + + align:start position:0% +service runtime and do anything that the +trusted service runtime can do then they + + align:start position:0% +trusted service runtime can do then they + + + align:start position:0% +trusted service runtime can do then they +could sort of violate this property so + + align:start position:0% +could sort of violate this property so + + + align:start position:0% +could sort of violate this property so +in some ways this is really like a + + align:start position:0% +in some ways this is really like a + + + align:start position:0% +in some ways this is really like a +supporting mechanism for enforcing that + + align:start position:0% +supporting mechanism for enforcing that + + + align:start position:0% +supporting mechanism for enforcing that +um in in principle this could also be + + align:start position:0% +um in in principle this could also be + + + align:start position:0% +um in in principle this could also be +used for lighter weight isolation if you + + align:start position:0% +used for lighter weight isolation if you + + + align:start position:0% +used for lighter weight isolation if you +could run this native client module + + align:start position:0% +could run this native client module + + + align:start position:0% +could run this native client module +inside of the browser process itself and + + align:start position:0% +inside of the browser process itself and + + + align:start position:0% +inside of the browser process itself and +not start an extra process but it turns + + align:start position:0% +not start an extra process but it turns + + + align:start position:0% +not start an extra process but it turns +out for performance reasons they really + + align:start position:0% +out for performance reasons they really + + + align:start position:0% +out for performance reasons they really +have to tie down the module to this + + align:start position:0% +have to tie down the module to this + + + align:start position:0% +have to tie down the module to this +particular range of memory or it has to + + align:start position:0% +particular range of memory or it has to + + + align:start position:0% +particular range of memory or it has to +start at zero anyway uh so this means + + align:start position:0% +start at zero anyway uh so this means + + + align:start position:0% +start at zero anyway uh so this means +that you can only have one really native + + align:start position:0% +that you can only have one really native + + + align:start position:0% +that you can only have one really native +client untrusted module per process so + + align:start position:0% +client untrusted module per process so + + + align:start position:0% +client untrusted module per process so +you probably are going to start a + + align:start position:0% +you probably are going to start a + + + align:start position:0% +you probably are going to start a +separate process + + align:start position:0% +separate process + + + align:start position:0% +separate process +anyway make sense other questions yeah + + align:start position:0% +anyway make sense other questions yeah + + + align:start position:0% +anyway make sense other questions yeah +is it like is there actually a reason + + align:start position:0% +is it like is there actually a reason + + + align:start position:0% +is it like is there actually a reason +why it has to start at zero yeah so it + + align:start position:0% +why it has to start at zero yeah so it + + + align:start position:0% +why it has to start at zero yeah so it +turns out it's more efficient in terms + + align:start position:0% +turns out it's more efficient in terms + + + align:start position:0% +turns out it's more efficient in terms +of performance to enforce jump targets + + align:start position:0% +of performance to enforce jump targets + + + align:start position:0% +of performance to enforce jump targets +if you know that the legitimate address + + align:start position:0% +if you know that the legitimate address + + + align:start position:0% +if you know that the legitimate address +is a contiguous set of addresses + + align:start position:0% +is a contiguous set of addresses + + + align:start position:0% +is a contiguous set of addresses +starting at zero because you can then do + + align:start position:0% +starting at zero because you can then do + + + align:start position:0% +starting at zero because you can then do +it with a single and mask where all the + + align:start position:0% +it with a single and mask where all the + + + align:start position:0% +it with a single and mask where all the +High bits are one and only a couple of + + align:start position:0% +High bits are one and only a couple of + + + align:start position:0% +High bits are one and only a couple of +low bits are zeros + + align:start position:0% + + + + align:start position:0% + +well if you're willing well + + align:start position:0% +well if you're willing well + + + align:start position:0% +well if you're willing well +I thought the an mask was to ensure + + align:start position:0% +I thought the an mask was to ensure + + + align:start position:0% +I thought the an mask was to ensure +alignment right so the N mask ensures + + align:start position:0% +alignment right so the N mask ensures + + + align:start position:0% +alignment right so the N mask ensures +alignment you're right uh so so yeah so + + align:start position:0% +alignment you're right uh so so yeah so + + + align:start position:0% +alignment you're right uh so so yeah so +why do they start at zero um I think it + + align:start position:0% +why do they start at zero um I think it + + + align:start position:0% +why do they start at zero um I think it +probably helps them to avoid well I + + align:start position:0% +probably helps them to avoid well I + + + align:start position:0% +probably helps them to avoid well I +guess they rely on these on the + + align:start position:0% +guess they rely on these on the + + + align:start position:0% +guess they rely on these on the +segmentation Hardware so in principle + + align:start position:0% +segmentation Hardware so in principle + + + align:start position:0% +segmentation Hardware so in principle +maybe they could use the segmentation + + align:start position:0% +maybe they could use the segmentation + + + align:start position:0% +maybe they could use the segmentation +Hardware to shift the region up in terms + + align:start position:0% +Hardware to shift the region up in terms + + + align:start position:0% +Hardware to shift the region up in terms +of linear space so maybe it's just that + + align:start position:0% +of linear space so maybe it's just that + + + align:start position:0% +of linear space so maybe it's just that +the application sort of sees this range + + align:start position:0% +the application sort of sees this range + + + align:start position:0% +the application sort of sees this range +and you could actually place at + + align:start position:0% +and you could actually place at + + + align:start position:0% +and you could actually place at +different offsets in your virtual + + align:start position:0% +different offsets in your virtual + + + align:start position:0% +different offsets in your virtual +address space could be um + + align:start position:0% +address space could be um + + + align:start position:0% +address space could be um +yeah so maybe you could actually play + + align:start position:0% +yeah so maybe you could actually play + + + align:start position:0% +yeah so maybe you could actually play +tricks with the segmentation Hardware to + + align:start position:0% +tricks with the segmentation Hardware to + + + align:start position:0% +tricks with the segmentation Hardware to +run multiple modules in same address + + align:start position:0% +run multiple modules in same address + + + align:start position:0% +run multiple modules in same address +space it's also because they want to + + align:start position:0% +space it's also because they want to + + + align:start position:0% +space it's also because they want to +catch no point exceptions yeah so they + + align:start position:0% +catch no point exceptions yeah so they + + + align:start position:0% +catch no point exceptions yeah so they +want to catch null pointer exceptions + + align:start position:0% +want to catch null pointer exceptions + + + align:start position:0% +want to catch null pointer exceptions +but you could sort of do that because + + align:start position:0% +but you could sort of do that because + + + align:start position:0% +but you could sort of do that because +the null pointer I guess we'll talk + + align:start position:0% +the null pointer I guess we'll talk + + + align:start position:0% +the null pointer I guess we'll talk +about segmentation in a second but the + + align:start position:0% +about segmentation in a second but the + + + align:start position:0% +about segmentation in a second but the +null pointer actually go is relative to + + align:start position:0% +null pointer actually go is relative to + + + align:start position:0% +null pointer actually go is relative to +the segment in which you're accessing so + + align:start position:0% +the segment in which you're accessing so + + + align:start position:0% +the segment in which you're accessing so +if you shift the segment around then you + + align:start position:0% +if you shift the segment around then you + + + align:start position:0% +if you shift the segment around then you +could map a unused zero page at the + + align:start position:0% +could map a unused zero page at the + + + align:start position:0% +could map a unused zero page at the +beginning of everyone's segment uh so + + align:start position:0% +beginning of everyone's segment uh so + + + align:start position:0% +beginning of everyone's segment uh so +yeah it might be that uh you could do + + align:start position:0% +yeah it might be that uh you could do + + + align:start position:0% +yeah it might be that uh you could do +multiple modules + + align:start position:0% +multiple modules + + + align:start position:0% +multiple modules +um I think for well I guess one one + + align:start position:0% +um I think for well I guess one one + + + align:start position:0% +um I think for well I guess one one +reason they probably want to do this is + + align:start position:0% +reason they probably want to do this is + + + align:start position:0% +reason they probably want to do this is +that when they Port their stuff to 64 + + align:start position:0% +that when they Port their stuff to 64 + + + align:start position:0% +that when they Port their stuff to 64 +bits they have a slightly different + + align:start position:0% +bits they have a slightly different + + + align:start position:0% +bits they have a slightly different +design this paper doesn't really talk + + align:start position:0% +design this paper doesn't really talk + + + align:start position:0% +design this paper doesn't really talk +about it and I think in that 64-bit + + align:start position:0% +about it and I think in that 64-bit + + + align:start position:0% +about it and I think in that 64-bit +design the hardware itself got rid of + + align:start position:0% +design the hardware itself got rid of + + + align:start position:0% +design the hardware itself got rid of +some of the segmentation Hardware they + + align:start position:0% +some of the segmentation Hardware they + + + align:start position:0% +some of the segmentation Hardware they +were relying on for efficiency reasons + + align:start position:0% +were relying on for efficiency reasons + + + align:start position:0% +were relying on for efficiency reasons +uh and they have to do a much more + + align:start position:0% +uh and they have to do a much more + + + align:start position:0% +uh and they have to do a much more +software oriented approach in which case + + align:start position:0% +software oriented approach in which case + + + align:start position:0% +software oriented approach in which case +having the low bits does help them uh + + align:start position:0% +having the low bits does help them uh + + + align:start position:0% +having the low bits does help them uh +but in this 32-bit version I think yeah + + align:start position:0% +but in this 32-bit version I think yeah + + + align:start position:0% +but in this 32-bit version I think yeah +maybe that's true they there's not a + + align:start position:0% +maybe that's true they there's not a + + + align:start position:0% +maybe that's true they there's not a +deep reason why it has to start at zero + + align:start position:0% +deep reason why it has to start at zero + + + align:start position:0% +deep reason why it has to start at zero +fair enough other + + align:start position:0% +fair enough other + + + align:start position:0% +fair enough other +questions all right so so I guess we + + align:start position:0% +questions all right so so I guess we + + + align:start position:0% +questions all right so so I guess we +sort of roughly understand what uh the + + align:start position:0% +sort of roughly understand what uh the + + + align:start position:0% +sort of roughly understand what uh the +plan is or what we want to enforce in + + align:start position:0% +plan is or what we want to enforce in + + + align:start position:0% +plan is or what we want to enforce in +terms of safety so how do we do this so + + align:start position:0% +terms of safety so how do we do this so + + + align:start position:0% +terms of safety so how do we do this so +let's look at some at least naive + + align:start position:0% +let's look at some at least naive + + + align:start position:0% +let's look at some at least naive +approach and see what's how could we + + align:start position:0% +approach and see what's how could we + + + align:start position:0% +approach and see what's how could we +screw it up I guess and then we'll try + + align:start position:0% +screw it up I guess and then we'll try + + + align:start position:0% +screw it up I guess and then we'll try +to fix it afterwards so I guess the + + align:start position:0% +to fix it afterwards so I guess the + + + align:start position:0% +to fix it afterwards so I guess the +naive plan that uh you know sort of + + align:start position:0% +naive plan that uh you know sort of + + + align:start position:0% +naive plan that uh you know sort of +looks like what they do is is to just + + align:start position:0% +looks like what they do is is to just + + + align:start position:0% +looks like what they do is is to just +look for disallowed instructions by just + + align:start position:0% +look for disallowed instructions by just + + + align:start position:0% +look for disallowed instructions by just +scanning the executable from the start + + align:start position:0% +scanning the executable from the start + + + align:start position:0% +scanning the executable from the start +going + + align:start position:0% + + + + align:start position:0% + +forward so how do you detect bad + + align:start position:0% +forward so how do you detect bad + + + align:start position:0% +forward so how do you detect bad +instructions well you could just take + + align:start position:0% +instructions well you could just take + + + align:start position:0% +instructions well you could just take +the sort of program code and you sort of + + align:start position:0% +the sort of program code and you sort of + + + align:start position:0% +the sort of program code and you sort of +lay it out in a giant string that goes + + align:start position:0% +lay it out in a giant string that goes + + + align:start position:0% +lay it out in a giant string that goes +from zero up to well maybe all the way + + align:start position:0% +from zero up to well maybe all the way + + + align:start position:0% +from zero up to well maybe all the way +to 256 megabytes depending on how big + + align:start position:0% +to 256 megabytes depending on how big + + + align:start position:0% +to 256 megabytes depending on how big +your code is and you start looking okay + + align:start position:0% +your code is and you start looking okay + + + align:start position:0% +your code is and you start looking okay +well maybe there's a op instruction here + + align:start position:0% +well maybe there's a op instruction here + + + align:start position:0% +well maybe there's a op instruction here +maybe there are some sort of an ad + + align:start position:0% +maybe there are some sort of an ad + + + align:start position:0% +maybe there are some sort of an ad +instruction there maybe there's a knot I + + align:start position:0% +instruction there maybe there's a knot I + + + align:start position:0% +instruction there maybe there's a knot I +don't know some sort of a jump Etc and + + align:start position:0% +don't know some sort of a jump Etc and + + + align:start position:0% +don't know some sort of a jump Etc and +you just keep looking and if you find a + + align:start position:0% +you just keep looking and if you find a + + + align:start position:0% +you just keep looking and if you find a +bad instruction you say ah it's a bad + + align:start position:0% +bad instruction you say ah it's a bad + + + align:start position:0% +bad instruction you say ah it's a bad +module and then you discard it and if + + align:start position:0% +module and then you discard it and if + + + align:start position:0% +module and then you discard it and if +you don't see any system call or in + + align:start position:0% +you don't see any system call or in + + + align:start position:0% +you don't see any system call or in +instructions then you're going to allow + + align:start position:0% +instructions then you're going to allow + + + align:start position:0% +instructions then you're going to allow +this module to run module or whatever it + + align:start position:0% +this module to run module or whatever it + + + align:start position:0% +this module to run module or whatever it +is will do for the inbounds + + align:start position:0% +is will do for the inbounds + + + align:start position:0% +is will do for the inbounds +checks so is this going to + + align:start position:0% +checks so is this going to + + + align:start position:0% +checks so is this going to +work so why not what are they worried + + align:start position:0% +work so why not what are they worried + + + align:start position:0% +work so why not what are they worried +about why is this so complicated + + align:start position:0% +about why is this so complicated + + + align:start position:0% +about why is this so complicated +overlapping instruction yeah so the + + align:start position:0% +overlapping instruction yeah so the + + + align:start position:0% +overlapping instruction yeah so the +weird thing is that x86 which is the + + align:start position:0% +weird thing is that x86 which is the + + + align:start position:0% +weird thing is that x86 which is the +sort of platform they're targeting has + + align:start position:0% +sort of platform they're targeting has + + + align:start position:0% +sort of platform they're targeting has +variable length + + align:start position:0% + + + + align:start position:0% + +instructions so this means that the + + align:start position:0% +instructions so this means that the + + + align:start position:0% +instructions so this means that the +particular size of an instruction + + align:start position:0% +particular size of an instruction + + + align:start position:0% +particular size of an instruction +depends on the first few bytes of that + + align:start position:0% +depends on the first few bytes of that + + + align:start position:0% +depends on the first few bytes of that +instruction so you have to actually look + + align:start position:0% +instruction so you have to actually look + + + align:start position:0% +instruction so you have to actually look +at the first bite and say okay well the + + align:start position:0% +at the first bite and say okay well the + + + align:start position:0% +at the first bite and say okay well the +instruction is going to be this much + + align:start position:0% +instruction is going to be this much + + + align:start position:0% +instruction is going to be this much +more and then maybe you sort of have to + + align:start position:0% +more and then maybe you sort of have to + + + align:start position:0% +more and then maybe you sort of have to +look at a couple more bites and then + + align:start position:0% +look at a couple more bites and then + + + align:start position:0% +look at a couple more bites and then +decide okay well that's exactly how long + + align:start position:0% +decide okay well that's exactly how long + + + align:start position:0% +decide okay well that's exactly how long +it's going to be but you don't know + + align:start position:0% +it's going to be but you don't know + + + align:start position:0% +it's going to be but you don't know +ahead of time so some architectures like + + align:start position:0% +ahead of time so some architectures like + + + align:start position:0% +ahead of time so some architectures like +Spark arm uh myips um have more fixed + + align:start position:0% +Spark arm uh myips um have more fixed + + + align:start position:0% +Spark arm uh myips um have more fixed +length instructions well on arm for ex + + align:start position:0% +length instructions well on arm for ex + + + align:start position:0% +length instructions well on arm for ex +arm is slightly weird but it has two + + align:start position:0% +arm is slightly weird but it has two + + + align:start position:0% +arm is slightly weird but it has two +instruction lengths either everything is + + align:start position:0% +instruction lengths either everything is + + + align:start position:0% +instruction lengths either everything is +two bytes or everything is four bytes + + align:start position:0% +two bytes or everything is four bytes + + + align:start position:0% +two bytes or everything is four bytes +but in x86 the instructions could be + + align:start position:0% +but in x86 the instructions could be + + + align:start position:0% +but in x86 the instructions could be +like one b or 10 bytes or five bytes + + align:start position:0% +like one b or 10 bytes or five bytes + + + align:start position:0% +like one b or 10 bytes or five bytes +anything in between as well I forget + + align:start position:0% +anything in between as well I forget + + + align:start position:0% +anything in between as well I forget +actually how big you can get a pretty + + align:start position:0% +actually how big you can get a pretty + + + align:start position:0% +actually how big you can get a pretty +long instruction I think you can get + + align:start position:0% +long instruction I think you can get + + + align:start position:0% +long instruction I think you can get +like a 15 B instruction on x86 if you + + align:start position:0% +like a 15 B instruction on x86 if you + + + align:start position:0% +like a 15 B instruction on x86 if you +try hard um it's a complicated + + align:start position:0% +try hard um it's a complicated + + + align:start position:0% +try hard um it's a complicated +instruction set um but uh as a result + + align:start position:0% +instruction set um but uh as a result + + + align:start position:0% +instruction set um but uh as a result +the problem that could show up is that + + align:start position:0% +the problem that could show up is that + + + align:start position:0% +the problem that could show up is that +maybe you're scanning linearly and + + align:start position:0% +maybe you're scanning linearly and + + + align:start position:0% +maybe you're scanning linearly and +everything seems to be fine but maybe at + + align:start position:0% +everything seems to be fine but maybe at + + + align:start position:0% +everything seems to be fine but maybe at +runtime you'll actually jump into the + + align:start position:0% +runtime you'll actually jump into the + + + align:start position:0% +runtime you'll actually jump into the +middle of some instruction maybe it was + + align:start position:0% +middle of some instruction maybe it was + + + align:start position:0% +middle of some instruction maybe it was +a multi-te instruction if you interpret + + align:start position:0% +a multi-te instruction if you interpret + + + align:start position:0% +a multi-te instruction if you interpret +it starting from the second bite it + + align:start position:0% +it starting from the second bite it + + + align:start position:0% +it starting from the second bite it +looks like a completely different thing + + align:start position:0% +looks like a completely different thing + + + align:start position:0% +looks like a completely different thing +so just one example sort of playing + + align:start position:0% +so just one example sort of playing + + + align:start position:0% +so just one example sort of playing +around with an assembler and if you have + + align:start position:0% +around with an assembler and if you have + + + align:start position:0% +around with an assembler and if you have +an instruction like this + + align:start position:0% +an instruction like this + + + align:start position:0% +an instruction like this +25 uh CD 80 00 and if you interpret it + + align:start position:0% +25 uh CD 80 00 and if you interpret it + + + align:start position:0% +25 uh CD 80 00 and if you interpret it +as this five byte instruction meaning + + align:start position:0% +as this five byte instruction meaning + + + align:start position:0% +as this five byte instruction meaning +that you you look at this B and says oh + + align:start position:0% +that you you look at this B and says oh + + + align:start position:0% +that you you look at this B and says oh +yeah this is going to be a five byte + + align:start position:0% +yeah this is going to be a five byte + + + align:start position:0% +yeah this is going to be a five byte +instruction so you have to look five + + align:start position:0% +instruction so you have to look five + + + align:start position:0% +instruction so you have to look five +bytes forward and then this turns out to + + align:start position:0% +bytes forward and then this turns out to + + + align:start position:0% +bytes forward and then this turns out to +be a fairly benign instruction that's an + + align:start position:0% +be a fairly benign instruction that's an + + + align:start position:0% +be a fairly benign instruction that's an +end of the eax register with some + + align:start position:0% +end of the eax register with some + + + align:start position:0% +end of the eax register with some +particular constant that happens to be + + align:start position:0% +particular constant that happens to be + + + align:start position:0% +particular constant that happens to be +um I think + + align:start position:0% +um I think + + + align:start position:0% +um I think +0000 um 80 CD so this is one of these + + align:start position:0% +0000 um 80 CD so this is one of these + + + align:start position:0% +0000 um 80 CD so this is one of these +safe instructions that native client + + align:start position:0% +safe instructions that native client + + + align:start position:0% +safe instructions that native client +should just allow under the first rule + + align:start position:0% +should just allow under the first rule + + + align:start position:0% +should just allow under the first rule +in checking these binary instructions + + align:start position:0% +in checking these binary instructions + + + align:start position:0% +in checking these binary instructions +but if it turns out at runtime the CPU + + align:start position:0% +but if it turns out at runtime the CPU + + + align:start position:0% +but if it turns out at runtime the CPU +decides this is where it has to start + + align:start position:0% +decides this is where it has to start + + + align:start position:0% +decides this is where it has to start +executing the code then this instruction + + align:start position:0% +executing the code then this instruction + + + align:start position:0% +executing the code then this instruction +is actually a 4 byte instruction and + + align:start position:0% +is actually a 4 byte instruction and + + + align:start position:0% +is actually a 4 byte instruction and +it's actually an in instruction that + + align:start position:0% +it's actually an in instruction that + + + align:start position:0% +it's actually an in instruction that +makes an ox ad0 interrupt which is a way + + align:start position:0% +makes an ox ad0 interrupt which is a way + + + align:start position:0% +makes an ox ad0 interrupt which is a way +one way to make system calls in Linux so + + align:start position:0% +one way to make system calls in Linux so + + + align:start position:0% +one way to make system calls in Linux so +if you miss this fact then potentially + + align:start position:0% +if you miss this fact then potentially + + + align:start position:0% +if you miss this fact then potentially +you're going to allow this unrusted + + align:start position:0% +you're going to allow this unrusted + + + align:start position:0% +you're going to allow this unrusted +module to jump into the kernel and make + + align:start position:0% +module to jump into the kernel and make + + + align:start position:0% +module to jump into the kernel and make +system calls which is what you wanted to + + align:start position:0% +system calls which is what you wanted to + + + align:start position:0% +system calls which is what you wanted to +prevent make sense + + align:start position:0% + + + + align:start position:0% + +so how could we prevent it like one + + align:start position:0% +so how could we prevent it like one + + + align:start position:0% +so how could we prevent it like one +possibility is maybe we should like + + align:start position:0% +possibility is maybe we should like + + + align:start position:0% +possibility is maybe we should like +try looking at every bite offet because + + align:start position:0% +try looking at every bite offet because + + + align:start position:0% +try looking at every bite offet because +you know at least x86 can only start + + align:start position:0% +you know at least x86 can only start + + + align:start position:0% +you know at least x86 can only start +interpreting instruction on a bite + + align:start position:0% +interpreting instruction on a bite + + + align:start position:0% +interpreting instruction on a bite +boundary instead of a bit boundary um so + + align:start position:0% +boundary instead of a bit boundary um so + + + align:start position:0% +boundary instead of a bit boundary um so +you like look at every single possible + + align:start position:0% +you like look at every single possible + + + align:start position:0% +you like look at every single possible +bite offset and you see what instruction + + align:start position:0% +bite offset and you see what instruction + + + align:start position:0% +bite offset and you see what instruction +starts + + align:start position:0% +starts + + + align:start position:0% +starts +there is this a reasonable plan could it + + align:start position:0% +there is this a reasonable plan could it + + + align:start position:0% +there is this a reasonable plan could it +work yeah I mean what if someone + + align:start position:0% +work yeah I mean what if someone + + + align:start position:0% +work yeah I mean what if someone +actually is doing in and that they're + + align:start position:0% +actually is doing in and that they're + + + align:start position:0% +actually is doing in and that they're +never going to jump into that and now + + align:start position:0% +never going to jump into that and now + + + align:start position:0% +never going to jump into that and now +you're disallowing their program right + + align:start position:0% +you're disallowing their program right + + + align:start position:0% +you're disallowing their program right +so it's basically prone to potentially + + align:start position:0% +so it's basically prone to potentially + + + align:start position:0% +so it's basically prone to potentially +false positives um now you know if you + + align:start position:0% +false positives um now you know if you + + + align:start position:0% +false positives um now you know if you +really wanted to you could probably + + align:start position:0% +really wanted to you could probably + + + align:start position:0% +really wanted to you could probably +contort yourself and change the uh code + + align:start position:0% +contort yourself and change the uh code + + + align:start position:0% +contort yourself and change the uh code +a + + align:start position:0% +a + + + align:start position:0% +a +little and somehow avoid this if you + + align:start position:0% +little and somehow avoid this if you + + + align:start position:0% +little and somehow avoid this if you +knew exactly what the Checker was + + align:start position:0% +knew exactly what the Checker was + + + align:start position:0% +knew exactly what the Checker was +looking for you could potentially change + + align:start position:0% +looking for you could potentially change + + + align:start position:0% +looking for you could potentially change +these instructions you know maybe like + + align:start position:0% +these instructions you know maybe like + + + align:start position:0% +these instructions you know maybe like +end it with one thing first and then end + + align:start position:0% +end it with one thing first and then end + + + align:start position:0% +end it with one thing first and then end +it for with another mask later but to + + align:start position:0% +it for with another mask later but to + + + align:start position:0% +it for with another mask later but to +just avoid these suspicious bite + + align:start position:0% +just avoid these suspicious bite + + + align:start position:0% +just avoid these suspicious bite +patterns but that just seems pretty + + align:start position:0% +patterns but that just seems pretty + + + align:start position:0% +patterns but that just seems pretty +awkward to do um now it is actually + + align:start position:0% +awkward to do um now it is actually + + + align:start position:0% +awkward to do um now it is actually +possible Right their architecture does + + align:start position:0% +possible Right their architecture does + + + align:start position:0% +possible Right their architecture does +involve changing the compiler so in + + align:start position:0% +involve changing the compiler so in + + + align:start position:0% +involve changing the compiler so in +principle they do have some component + + align:start position:0% +principle they do have some component + + + align:start position:0% +principle they do have some component +that actually has to compile the code + + align:start position:0% +that actually has to compile the code + + + align:start position:0% +that actually has to compile the code +correctly it's not like you can you + + align:start position:0% +correctly it's not like you can you + + + align:start position:0% +correctly it's not like you can you +can't just take offthe shelf GCC and + + align:start position:0% +can't just take offthe shelf GCC and + + + align:start position:0% +can't just take offthe shelf GCC and +compile code for Native client so in + + align:start position:0% +compile code for Native client so in + + + align:start position:0% +compile code for Native client so in +principle it's doable but I think + + align:start position:0% +principle it's doable but I think + + + align:start position:0% +principle it's doable but I think +they're just thinking it's too much + + align:start position:0% +they're just thinking it's too much + + + align:start position:0% +they're just thinking it's too much +hassle and it's not going to be reliable + + align:start position:0% +hassle and it's not going to be reliable + + + align:start position:0% +hassle and it's not going to be reliable +or high performance + + align:start position:0% +or high performance + + + align:start position:0% +or high performance +Etc makes sense and plus there's a + + align:start position:0% +Etc makes sense and plus there's a + + + align:start position:0% +Etc makes sense and plus there's a +couple of x86 instructions that are + + align:start position:0% +couple of x86 instructions that are + + + align:start position:0% +couple of x86 instructions that are +prohibited or should be unsafe and + + align:start position:0% +prohibited or should be unsafe and + + + align:start position:0% +prohibited or should be unsafe and +prohibited but they're like one bite + + align:start position:0% +prohibited but they're like one bite + + + align:start position:0% +prohibited but they're like one bite +long so that is gonna be pretty damaging + + align:start position:0% +long so that is gonna be pretty damaging + + + align:start position:0% +long so that is gonna be pretty damaging +to to look for or to filter + + align:start position:0% +to to look for or to filter + + + align:start position:0% +to to look for or to filter +out okay so if they can't just + + align:start position:0% +out okay so if they can't just + + + align:start position:0% +out okay so if they can't just +disassemble sort of straight up and hope + + align:start position:0% +disassemble sort of straight up and hope + + + align:start position:0% +disassemble sort of straight up and hope +for the best then they need some other + + align:start position:0% +for the best then they need some other + + + align:start position:0% +for the best then they need some other +plan for doing this disassembly in a + + align:start position:0% +plan for doing this disassembly in a + + + align:start position:0% +plan for doing this disassembly in a +reliable fashion so so what is their + + align:start position:0% +reliable fashion so so what is their + + + align:start position:0% +reliable fashion so so what is their +plan a native client to ensure they + + align:start position:0% +plan a native client to ensure they + + + align:start position:0% +plan a native client to ensure they +don't get tripped up by this variable + + align:start position:0% +don't get tripped up by this variable + + + align:start position:0% +don't get tripped up by this variable +length + + align:start position:0% +length + + + align:start position:0% +length +encoding so I guess one way to think of + + align:start position:0% +encoding so I guess one way to think of + + + align:start position:0% +encoding so I guess one way to think of +it is um + + align:start position:0% + + + + align:start position:0% + +well okay so how are we're going to + + align:start position:0% +well okay so how are we're going to + + + align:start position:0% +well okay so how are we're going to +solve this reliable + + align:start position:0% + + + + align:start position:0% + +disassembly so in some sense right if we + + align:start position:0% +disassembly so in some sense right if we + + + align:start position:0% +disassembly so in some sense right if we +if we really do scan forward from the + + align:start position:0% +if we really do scan forward from the + + + align:start position:0% +if we really do scan forward from the +left to the right and we look for all + + align:start position:0% +left to the right and we look for all + + + align:start position:0% +left to the right and we look for all +the possible up + + align:start position:0% +the possible up + + + align:start position:0% +the possible up +codes if that's the way the code + + align:start position:0% +codes if that's the way the code + + + align:start position:0% +codes if that's the way the code +executes then we're in good shape so + + align:start position:0% +executes then we're in good shape so + + + align:start position:0% +executes then we're in good shape so +even if there is some weird instruction + + align:start position:0% +even if there is some weird instruction + + + align:start position:0% +even if there is some weird instruction +at a some offset then the CPU isn't + + align:start position:0% +at a some offset then the CPU isn't + + + align:start position:0% +at a some offset then the CPU isn't +actually going to jump there if it + + align:start position:0% +actually going to jump there if it + + + align:start position:0% +actually going to jump there if it +actually executes the same way that + + align:start position:0% +actually executes the same way that + + + align:start position:0% +actually executes the same way that +we're scanning the instructions stream + + align:start position:0% +we're scanning the instructions stream + + + align:start position:0% +we're scanning the instructions stream +from left to right so the problem with + + align:start position:0% +from left to right so the problem with + + + align:start position:0% +from left to right so the problem with +reli with getting the disassembly to be + + align:start position:0% +reli with getting the disassembly to be + + + align:start position:0% +reli with getting the disassembly to be +reliable really comes from the fact that + + align:start position:0% +reliable really comes from the fact that + + + align:start position:0% +reliable really comes from the fact that +there's + + align:start position:0% +there's + + + align:start position:0% +there's +jumps because if if we execute linearly + + align:start position:0% +jumps because if if we execute linearly + + + align:start position:0% +jumps because if if we execute linearly +from left to right then the CPU will + + align:start position:0% +from left to right then the CPU will + + + align:start position:0% +from left to right then the CPU will +follow the same rules that our Checker + + align:start position:0% +follow the same rules that our Checker + + + align:start position:0% +follow the same rules that our Checker +is following and see the same + + align:start position:0% +is following and see the same + + + align:start position:0% +is following and see the same +instruction Stream So the problem really + + align:start position:0% +instruction Stream So the problem really + + + align:start position:0% +instruction Stream So the problem really +comes down to what happens if there's a + + align:start position:0% +comes down to what happens if there's a + + + align:start position:0% +comes down to what happens if there's a +jump somewhere in the application could + + align:start position:0% +jump somewhere in the application could + + + align:start position:0% +jump somewhere in the application could +have jump to some position in the code + + align:start position:0% +have jump to some position in the code + + + align:start position:0% +have jump to some position in the code +that we didn't observe in our left to + + align:start position:0% +that we didn't observe in our left to + + + align:start position:0% +that we didn't observe in our left to +right scan + + align:start position:0% +right scan + + + align:start position:0% +right scan +so this is what they're sort of going + + align:start position:0% +so this is what they're sort of going + + + align:start position:0% +so this is what they're sort of going +after in the reliable disassembly and + + align:start position:0% +after in the reliable disassembly and + + + align:start position:0% +after in the reliable disassembly and +the basic plan is to just check where + + align:start position:0% +the basic plan is to just check where + + + align:start position:0% +the basic plan is to just check where +all the jumps go so it's actually fairly + + align:start position:0% +all the jumps go so it's actually fairly + + + align:start position:0% +all the jumps go so it's actually fairly +straightforward at some level um they + + align:start position:0% +straightforward at some level um they + + + align:start position:0% +straightforward at some level um they +have I guess a bunch of rules we'll look + + align:start position:0% +have I guess a bunch of rules we'll look + + + align:start position:0% +have I guess a bunch of rules we'll look +at in a second but roughly the plan is + + align:start position:0% +at in a second but roughly the plan is + + + align:start position:0% +at in a second but roughly the plan is +if you see a jump + + align:start position:0% +if you see a jump + + + align:start position:0% +if you see a jump +instruction then it actually has to be + + align:start position:0% +instruction then it actually has to be + + + align:start position:0% +instruction then it actually has to be +uh well you have to check that the + + align:start position:0% +uh well you have to check that the + + + align:start position:0% +uh well you have to check that the +target was seen before + + align:start position:0% + + + + align:start position:0% + +so you basically do the left to right + + align:start position:0% +so you basically do the left to right + + + align:start position:0% +so you basically do the left to right +scan that we sort of described in our + + align:start position:0% +scan that we sort of described in our + + + align:start position:0% +scan that we sort of described in our +naive approach here but then if you see + + align:start position:0% +naive approach here but then if you see + + + align:start position:0% +naive approach here but then if you see +any kind of a jump instruction then you + + align:start position:0% +any kind of a jump instruction then you + + + align:start position:0% +any kind of a jump instruction then you +see what the what is the address to + + align:start position:0% +see what the what is the address to + + + align:start position:0% +see what the what is the address to +which the jump instruction is pointing + + align:start position:0% +which the jump instruction is pointing + + + align:start position:0% +which the jump instruction is pointing +to and you make sure that it's an + + align:start position:0% +to and you make sure that it's an + + + align:start position:0% +to and you make sure that it's an +address that you saw in your left to + + align:start position:0% +address that you saw in your left to + + + align:start position:0% +address that you saw in your left to +right + + align:start position:0% +right + + + align:start position:0% +right +disassembly so if there's a jump + + align:start position:0% +disassembly so if there's a jump + + + align:start position:0% +disassembly so if there's a jump +instruction for example that goes to + + align:start position:0% +instruction for example that goes to + + + align:start position:0% +instruction for example that goes to +that CD bite then we're going to flag + + align:start position:0% +that CD bite then we're going to flag + + + align:start position:0% +that CD bite then we're going to flag +that jump as invalid because we never + + align:start position:0% +that jump as invalid because we never + + + align:start position:0% +that jump as invalid because we never +saw an instruction starting at the CD + + align:start position:0% +saw an instruction starting at the CD + + + align:start position:0% +saw an instruction starting at the CD +bite we saw a different instruction but + + align:start position:0% +bite we saw a different instruction but + + + align:start position:0% +bite we saw a different instruction but +if all the instruction if all the jumps + + align:start position:0% +if all the instruction if all the jumps + + + align:start position:0% +if all the instruction if all the jumps +go to the start of instructions we saw + + align:start position:0% +go to the start of instructions we saw + + + align:start position:0% +go to the start of instructions we saw +then we're in good + + align:start position:0% +then we're in good + + + align:start position:0% +then we're in good +shape that make + + align:start position:0% +shape that make + + + align:start position:0% +shape that make +sense so the one of course problem is + + align:start position:0% +sense so the one of course problem is + + + align:start position:0% +sense so the one of course problem is +that you can't check the targets of + + align:start position:0% +that you can't check the targets of + + + align:start position:0% +that you can't check the targets of +every jump in the program because there + + align:start position:0% +every jump in the program because there + + + align:start position:0% +every jump in the program because there +might be indirect jumps so for example + + align:start position:0% +might be indirect jumps so for example + + + align:start position:0% +might be indirect jumps so for example +in xd6 you could actually have something + + align:start position:0% +in xd6 you could actually have something + + + align:start position:0% +in xd6 you could actually have something +like jump to the value of the eax + + align:start position:0% +like jump to the value of the eax + + + align:start position:0% +like jump to the value of the eax +register so this is great for + + align:start position:0% +register so this is great for + + + align:start position:0% +register so this is great for +implementing function pointers you store + + align:start position:0% +implementing function pointers you store + + + align:start position:0% +implementing function pointers you store +the function pointer somewhere in memory + + align:start position:0% +the function pointer somewhere in memory + + + align:start position:0% +the function pointer somewhere in memory +then you load the function pointer into + + align:start position:0% +then you load the function pointer into + + + align:start position:0% +then you load the function pointer into +some register at run time and then you + + align:start position:0% +some register at run time and then you + + + align:start position:0% +some register at run time and then you +jump to whatever address was in the that + + align:start position:0% +jump to whatever address was in the that + + + align:start position:0% +jump to whatever address was in the that +memory location and + + align:start position:0% +memory location and + + + align:start position:0% +memory location and +register so how do these guys deal with + + align:start position:0% +register so how do these guys deal with + + + align:start position:0% +register so how do these guys deal with +these indirect jumps so they have no + + align:start position:0% +these indirect jumps so they have no + + + align:start position:0% +these indirect jumps so they have no +idea if it's actually going to jump to + + align:start position:0% +idea if it's actually going to jump to + + + align:start position:0% +idea if it's actually going to jump to +the CD b or the 25 byte what do they do + + align:start position:0% +the CD b or the 25 byte what do they do + + + align:start position:0% +the CD b or the 25 byte what do they do +yeah yeah so this is their basically + + align:start position:0% +yeah yeah so this is their basically + + + align:start position:0% +yeah yeah so this is their basically +main trick here is instrumentation so + + align:start position:0% +main trick here is instrumentation so + + + align:start position:0% +main trick here is instrumentation so +whenever they see a jump like this what + + align:start position:0% +whenever they see a jump like this what + + + align:start position:0% +whenever they see a jump like this what +they actually what the compiler is going + + align:start position:0% +they actually what the compiler is going + + + align:start position:0% +they actually what the compiler is going +to generate is a proof that this jump is + + align:start position:0% +to generate is a proof that this jump is + + + align:start position:0% +to generate is a proof that this jump is +actually going to do the the right thing + + align:start position:0% +actually going to do the the right thing + + + align:start position:0% +actually going to do the the right thing +and the way they actually do this is + + align:start position:0% +and the way they actually do this is + + + align:start position:0% +and the way they actually do this is +well they don't actually know it's + + align:start position:0% +well they don't actually know it's + + + align:start position:0% +well they don't actually know it's +actually kind of hard to put in a proof + + align:start position:0% +actually kind of hard to put in a proof + + + align:start position:0% +actually kind of hard to put in a proof +here that it's one of the addresses that + + align:start position:0% +here that it's one of the addresses that + + + align:start position:0% +here that it's one of the addresses that +you saw during the left to right + + align:start position:0% +you saw during the left to right + + + align:start position:0% +you saw during the left to right +disassembly so instead what they do is + + align:start position:0% +disassembly so instead what they do is + + + align:start position:0% +disassembly so instead what they do is +they want to make sure that all the + + align:start position:0% +they want to make sure that all the + + + align:start position:0% +they want to make sure that all the +jumps go to multiples of 32 bytes and + + align:start position:0% +jumps go to multiples of 32 bytes and + + + align:start position:0% +jumps go to multiples of 32 bytes and +the way they do this is they actually + + align:start position:0% +the way they do this is they actually + + + align:start position:0% +the way they do this is they actually +change all the jump instructions into + + align:start position:0% +change all the jump instructions into + + + align:start position:0% +change all the jump instructions into +something that they call a pseudo + + align:start position:0% +something that they call a pseudo + + + align:start position:0% +something that they call a pseudo +instruction so there's still that sort + + align:start position:0% +instruction so there's still that sort + + + align:start position:0% +instruction so there's still that sort +of jump to you know gu the eax register + + align:start position:0% +of jump to you know gu the eax register + + + align:start position:0% +of jump to you know gu the eax register +at the + + align:start position:0% +at the + + + align:start position:0% +at the +end but they prefix it with an end + + align:start position:0% +end but they prefix it with an end + + + align:start position:0% +end but they prefix it with an end +instruction that uh is going to + + align:start position:0% +instruction that uh is going to + + + align:start position:0% +instruction that uh is going to +clear the low five + + align:start position:0% +clear the low five + + + align:start position:0% +clear the low five +bits + + align:start position:0% +bits + + + align:start position:0% +bits +F uh 1 2 3 4 5 6 e0 with the eax + + align:start position:0% +F uh 1 2 3 4 5 6 e0 with the eax + + + align:start position:0% +F uh 1 2 3 4 5 6 e0 with the eax +register so this and instruction clears + + align:start position:0% +register so this and instruction clears + + + align:start position:0% +register so this and instruction clears +the low five bits which means that it + + align:start position:0% +the low five bits which means that it + + + align:start position:0% +the low five bits which means that it +forces this value to be a multiple of 32 + + align:start position:0% +forces this value to be a multiple of 32 + + + align:start position:0% +forces this value to be a multiple of 32 +2 to the + + align:start position:0% +2 to the + + + align:start position:0% +2 to the +5 and then you jump to it so if you look + + align:start position:0% +5 and then you jump to it so if you look + + + align:start position:0% +5 and then you jump to it so if you look +at it during verification time then you + + align:start position:0% +at it during verification time then you + + + align:start position:0% +at it during verification time then you +can sort of convince yourself that this + + align:start position:0% +can sort of convince yourself that this + + + align:start position:0% +can sort of convince yourself that this +instruction this in this instruction + + align:start position:0% +instruction this in this instruction + + + align:start position:0% +instruction this in this instruction +pair will only jump to a multiple of 32 + + align:start position:0% +pair will only jump to a multiple of 32 + + + align:start position:0% +pair will only jump to a multiple of 32 +bytes and then in order to make sure + + align:start position:0% +bytes and then in order to make sure + + + align:start position:0% +bytes and then in order to make sure +that this is not going to jump to some + + align:start position:0% +that this is not going to jump to some + + + align:start position:0% +that this is not going to jump to some +weird instruction you're going to + + align:start position:0% +weird instruction you're going to + + + align:start position:0% +weird instruction you're going to +enforce an extra rule which is that + + align:start position:0% +enforce an extra rule which is that + + + align:start position:0% +enforce an extra rule which is that +during your disassembly when you're + + align:start position:0% +during your disassembly when you're + + + align:start position:0% +during your disassembly when you're +scanning the instructions from left to + + align:start position:0% +scanning the instructions from left to + + + align:start position:0% +scanning the instructions from left to +right you're going to ensure that every + + align:start position:0% +right you're going to ensure that every + + + align:start position:0% +right you're going to ensure that every +multiple of 32 bytes is a start of a + + align:start position:0% +multiple of 32 bytes is a start of a + + + align:start position:0% +multiple of 32 bytes is a start of a +valid + + align:start position:0% +valid + + + align:start position:0% +valid +instruction so in addition to this + + align:start position:0% +instruction so in addition to this + + + align:start position:0% +instruction so in addition to this +instrumentation you also are going to + + align:start position:0% +instrumentation you also are going to + + + align:start position:0% +instrumentation you also are going to +check that + + align:start position:0% +check that + + + align:start position:0% +check that +every multiple of + + align:start position:0% +every multiple of + + + align:start position:0% +every multiple of +32 is a valid + + align:start position:0% + + + + align:start position:0% + +instruction and well what what I mean by + + align:start position:0% +instruction and well what what I mean by + + + align:start position:0% +instruction and well what what I mean by +valid instruction here is it's an + + align:start position:0% +valid instruction here is it's an + + + align:start position:0% +valid instruction here is it's an +instruction that you see when you + + align:start position:0% +instruction that you see when you + + + align:start position:0% +instruction that you see when you +disassemble from left to right + + align:start position:0% +disassemble from left to right + + + align:start position:0% +disassemble from left to right +yeah2 well yeah so why do they choose 32 + + align:start position:0% +yeah2 well yeah so why do they choose 32 + + + align:start position:0% +yeah2 well yeah so why do they choose 32 +that seems like some magic number they + + align:start position:0% +that seems like some magic number they + + + align:start position:0% +that seems like some magic number they +pulled out of a hat like should you + + align:start position:0% +pulled out of a hat like should you + + + align:start position:0% +pulled out of a hat like should you +choose a thousand or + + align:start position:0% +choose a thousand or + + + align:start position:0% +choose a thousand or +five any comment okay like should we + + align:start position:0% +five any comment okay like should we + + + align:start position:0% +five any comment okay like should we +choose five is okay so why is five bad + + align:start position:0% +choose five is okay so why is five bad + + + align:start position:0% +choose five is okay so why is five bad +power of two yes okay so we want a power + + align:start position:0% +power of two yes okay so we want a power + + + align:start position:0% +power of two yes okay so we want a power +of two okay so good point because + + align:start position:0% +of two okay so good point because + + + align:start position:0% +of two okay so good point because +otherwise like ensuring something is a + + align:start position:0% +otherwise like ensuring something is a + + + align:start position:0% +otherwise like ensuring something is a +multiple of five is going to require a + + align:start position:0% +multiple of five is going to require a + + + align:start position:0% +multiple of five is going to require a +couple of instruction here which is + + align:start position:0% +couple of instruction here which is + + + align:start position:0% +couple of instruction here which is +going to lead to overhead okay how about + + align:start position:0% +going to lead to overhead okay how about + + + align:start position:0% +going to lead to overhead okay how about +eight is eight good enough yeah you can + + align:start position:0% +eight is eight good enough yeah you can + + + align:start position:0% +eight is eight good enough yeah you can +have instruction long yeah okay so it + + align:start position:0% +have instruction long yeah okay so it + + + align:start position:0% +have instruction long yeah okay so it +has to be at least as long as the + + align:start position:0% +has to be at least as long as the + + + align:start position:0% +has to be at least as long as the +longest x86 instruction you want to + + align:start position:0% +longest x86 instruction you want to + + + align:start position:0% +longest x86 instruction you want to +allow so if there's a 10 BTE instruction + + align:start position:0% +allow so if there's a 10 BTE instruction + + + align:start position:0% +allow so if there's a 10 BTE instruction +everything has to be a multiple of eight + + align:start position:0% +everything has to be a multiple of eight + + + align:start position:0% +everything has to be a multiple of eight +well you're kind of screwed with that 10 + + align:start position:0% +well you're kind of screwed with that 10 + + + align:start position:0% +well you're kind of screwed with that 10 +B instruction there's nowhere to put it + + align:start position:0% +B instruction there's nowhere to put it + + + align:start position:0% +B instruction there's nowhere to put it +um so it has to be at least as long so + + align:start position:0% +um so it has to be at least as long so + + + align:start position:0% +um so it has to be at least as long so +32 is pretty good like the biggest I + + align:start position:0% +32 is pretty good like the biggest I + + + align:start position:0% +32 is pretty good like the biggest I +could find was 15 bytes so it's probably + + align:start position:0% +could find was 15 bytes so it's probably + + + align:start position:0% +could find was 15 bytes so it's probably +good enough yeah be longer than that I + + align:start position:0% +good enough yeah be longer than that I + + + align:start position:0% +good enough yeah be longer than that I +think it's called the trampoline code + + align:start position:0% +think it's called the trampoline code + + + align:start position:0% +think it's called the trampoline code +they have to like you know have a he + + align:start position:0% +they have to like you know have a he + + + align:start position:0% +they have to like you know have a he +instruction at the beginning second so + + align:start position:0% +instruction at the beginning second so + + + align:start position:0% +instruction at the beginning second so +you can't just jump directly into there + + align:start position:0% +you can't just jump directly into there + + + align:start position:0% +you can't just jump directly into there +like code and then they also need REM + + align:start position:0% +like code and then they also need REM + + + align:start position:0% +like code and then they also need REM +jump instruction that like jumps to you + + align:start position:0% +jump instruction that like jumps to you + + + align:start position:0% +jump instruction that like jumps to you +know another like that's right yeah so + + align:start position:0% +know another like that's right yeah so + + + align:start position:0% +know another like that's right yeah so +you have to be able to fit for their + + align:start position:0% +you have to be able to fit for their + + + align:start position:0% +you have to be able to fit for their +entry and exit from The Trusted service + + align:start position:0% +entry and exit from The Trusted service + + + align:start position:0% +entry and exit from The Trusted service +run time you need to be able to fit some + + align:start position:0% +run time you need to be able to fit some + + + align:start position:0% +run time you need to be able to fit some +non-trivial amount of code in a single + + align:start position:0% +non-trivial amount of code in a single + + + align:start position:0% +non-trivial amount of code in a single +32 byte slot we'll see how this works in + + align:start position:0% +32 byte slot we'll see how this works in + + + align:start position:0% +32 byte slot we'll see how this works in +a second or even 31 byte slot as you're + + align:start position:0% +a second or even 31 byte slot as you're + + + align:start position:0% +a second or even 31 byte slot as you're +pointing out for one hold instruction um + + align:start position:0% +pointing out for one hold instruction um + + + align:start position:0% +pointing out for one hold instruction um +should it be much larger should we make + + align:start position:0% +should it be much larger should we make + + + align:start position:0% +should it be much larger should we make +it I don't know a th by well 1024 + + align:start position:0% +it I don't know a th by well 1024 + + + align:start position:0% +it I don't know a th by well 1024 +problem your too SP because you have + + align:start position:0% +problem your too SP because you have + + + align:start position:0% +problem your too SP because you have +jum yeah so if if you if you have a lot + + align:start position:0% +jum yeah so if if you if you have a lot + + + align:start position:0% +jum yeah so if if you if you have a lot +of function pointers or lots of sort of + + align:start position:0% +of function pointers or lots of sort of + + + align:start position:0% +of function pointers or lots of sort of +indirect jumps then every time you want + + align:start position:0% +indirect jumps then every time you want + + + align:start position:0% +indirect jumps then every time you want +to create some place where you're going + + align:start position:0% +to create some place where you're going + + + align:start position:0% +to create some place where you're going +to jump two you have to Pat it out to + + align:start position:0% +to jump two you have to Pat it out to + + + align:start position:0% +to jump two you have to Pat it out to +the next boundary of whatever this value + + align:start position:0% +the next boundary of whatever this value + + + align:start position:0% +the next boundary of whatever this value +is so with 32 maybe that's okay you're + + align:start position:0% +is so with 32 maybe that's okay you're + + + align:start position:0% +is so with 32 maybe that's okay you're +like well worst case you waste 31 bytes + + align:start position:0% +like well worst case you waste 31 bytes + + + align:start position:0% +like well worst case you waste 31 bytes +because you just need to fast forward to + + align:start position:0% +because you just need to fast forward to + + + align:start position:0% +because you just need to fast forward to +the next boundary but if it's a multiple + + align:start position:0% +the next boundary but if it's a multiple + + + align:start position:0% +the next boundary but if it's a multiple +of a 1024 then all of a sudden you're + + align:start position:0% +of a 1024 then all of a sudden you're + + + align:start position:0% +of a 1024 then all of a sudden you're +wasting a kilobyte of memory for an + + align:start position:0% +wasting a kilobyte of memory for an + + + align:start position:0% +wasting a kilobyte of memory for an +indirect + + align:start position:0% +indirect + + + align:start position:0% +indirect +jump and if you have probably you know + + align:start position:0% +jump and if you have probably you know + + + align:start position:0% +jump and if you have probably you know +short functions or you know lots of + + align:start position:0% +short functions or you know lots of + + + align:start position:0% +short functions or you know lots of +function pointers then this might + + align:start position:0% +function pointers then this might + + + align:start position:0% +function pointers then this might +actually be a memory overhead all of a + + align:start position:0% +actually be a memory overhead all of a + + + align:start position:0% +actually be a memory overhead all of a +sudden as well do that make sense + + align:start position:0% +sudden as well do that make sense + + + align:start position:0% +sudden as well do that make sense +roughly so yeah I think the 32 is not + + align:start position:0% +roughly so yeah I think the 32 is not + + + align:start position:0% +roughly so yeah I think the 32 is not +like set in stone like native client has + + align:start position:0% +like set in stone like native client has + + + align:start position:0% +like set in stone like native client has +to have 32 byte blocks but you know + + align:start position:0% +to have 32 byte blocks but you know + + + align:start position:0% +to have 32 byte blocks but you know +something on that order probably works + + align:start position:0% +something on that order probably works + + + align:start position:0% +something on that order probably works +16 is probably a little short on the + + align:start position:0% +16 is probably a little short on the + + + align:start position:0% +16 is probably a little short on the +other hand like 64 could work 128 maybe + + align:start position:0% +other hand like 64 could work 128 maybe + + + align:start position:0% +other hand like 64 could work 128 maybe +it's getting a little longish but it's I + + align:start position:0% +it's getting a little longish but it's I + + + align:start position:0% +it's getting a little longish but it's I +don't think you can derive 32 from first + + align:start position:0% +don't think you can derive 32 from first + + + align:start position:0% +don't think you can derive 32 from first +principles make sense + + align:start position:0% +principles make sense + + + align:start position:0% +principles make sense +all right so that's sort a plan for + + align:start position:0% +all right so that's sort a plan for + + + align:start position:0% +all right so that's sort a plan for +Reliable disassembly and as a result + + align:start position:0% +Reliable disassembly and as a result + + + align:start position:0% +Reliable disassembly and as a result +sort of the the compiler has to be a has + + align:start position:0% +sort of the the compiler has to be a has + + + align:start position:0% +sort of the the compiler has to be a has +to be a little bit careful when it's + + align:start position:0% +to be a little bit careful when it's + + + align:start position:0% +to be a little bit careful when it's +compiling your C or C++ code into a + + align:start position:0% +compiling your C or C++ code into a + + + align:start position:0% +compiling your C or C++ code into a +native client binary it has to basically + + align:start position:0% +native client binary it has to basically + + + align:start position:0% +native client binary it has to basically +follow these rules so whenever it has a + + align:start position:0% +follow these rules so whenever it has a + + + align:start position:0% +follow these rules so whenever it has a +jump it has to instru add this extra + + align:start position:0% +jump it has to instru add this extra + + + align:start position:0% +jump it has to instru add this extra +instruction in front and whenever it's + + align:start position:0% +instruction in front and whenever it's + + + align:start position:0% +instruction in front and whenever it's +creating a function that it's going to + + align:start position:0% +creating a function that it's going to + + + align:start position:0% +creating a function that it's going to +jump to or an instruction is going to + + align:start position:0% +jump to or an instruction is going to + + + align:start position:0% +jump to or an instruction is going to +jump to as we were talking about it has + + align:start position:0% +jump to as we were talking about it has + + + align:start position:0% +jump to as we were talking about it has +to Pat out and it can just Pat it out + + align:start position:0% +to Pat out and it can just Pat it out + + + align:start position:0% +to Pat out and it can just Pat it out +with zeros because all those have to be + + align:start position:0% +with zeros because all those have to be + + + align:start position:0% +with zeros because all those have to be +valid up code so it actually has to Pat + + align:start position:0% +valid up code so it actually has to Pat + + + align:start position:0% +valid up code so it actually has to Pat +it out with knobs just to make the + + align:start position:0% +it out with knobs just to make the + + + align:start position:0% +it out with knobs just to make the +validator happy just to make sure that + + align:start position:0% +validator happy just to make sure that + + + align:start position:0% +validator happy just to make sure that +every possible instruction is a valid + + align:start position:0% +every possible instruction is a valid + + + align:start position:0% +every possible instruction is a valid +one and luckily on x86 KN is a single + + align:start position:0% +one and luckily on x86 KN is a single + + + align:start position:0% +one and luckily on x86 KN is a single +bite so or at least there is a no that's + + align:start position:0% +bite so or at least there is a no that's + + + align:start position:0% +bite so or at least there is a no that's +a single bite there's many NOS on x86 uh + + align:start position:0% +a single bite there's many NOS on x86 uh + + + align:start position:0% +a single bite there's many NOS on x86 uh +so you can always pan things out to a + + align:start position:0% +so you can always pan things out to a + + + align:start position:0% +so you can always pan things out to a +multiple of whatever this constant + + align:start position:0% +multiple of whatever this constant + + + align:start position:0% +multiple of whatever this constant +is make + + align:start position:0% +is make + + + align:start position:0% +is make +sense all right so + + align:start position:0% +sense all right so + + + align:start position:0% +sense all right so +so what does this guarantee to us I + + align:start position:0% +so what does this guarantee to us I + + + align:start position:0% +so what does this guarantee to us I +guess what what what what this makes + + align:start position:0% +guess what what what what this makes + + + align:start position:0% +guess what what what what this makes +sure is that we always see what happens + + align:start position:0% +sure is that we always see what happens + + + align:start position:0% +sure is that we always see what happens +in terms of the instructions that will + + align:start position:0% +in terms of the instructions that will + + + align:start position:0% +in terms of the instructions that will +be executed so this finally gets us this + + align:start position:0% +be executed so this finally gets us this + + + align:start position:0% +be executed so this finally gets us this +rule so we can be sure there's never a + + align:start position:0% +rule so we can be sure there's never a + + + align:start position:0% +rule so we can be sure there's never a +system call being + + align:start position:0% +system call being + + + align:start position:0% +system call being +issued what about so this is for jumps + + align:start position:0% +issued what about so this is for jumps + + + align:start position:0% +issued what about so this is for jumps +what about returns how do they deal with + + align:start position:0% +what about returns how do they deal with + + + align:start position:0% +what about returns how do they deal with +returns can you return from a function + + align:start position:0% +returns can you return from a function + + + align:start position:0% +returns can you return from a function +in Native + + align:start position:0% +in Native + + + align:start position:0% +in Native +client gu what would happen if you ran a + + align:start position:0% +client gu what would happen if you ran a + + + align:start position:0% +client gu what would happen if you ran a +red op + + align:start position:0% +red op + + + align:start position:0% +red op +code that' be good yeah po the stack you + + align:start position:0% +code that' be good yeah po the stack you + + + align:start position:0% +code that' be good yeah po the stack you +don't want theode to be modifying your + + align:start position:0% +don't want theode to be modifying your + + + align:start position:0% +don't want theode to be modifying your +overall St well so it's true that it + + align:start position:0% +overall St well so it's true that it + + + align:start position:0% +overall St well so it's true that it +pops the stack + + align:start position:0% +pops the stack + + + align:start position:0% +pops the stack +but the stack that native client modules + + align:start position:0% +but the stack that native client modules + + + align:start position:0% +but the stack that native client modules +use is actually just some data inside of + + align:start position:0% +use is actually just some data inside of + + + align:start position:0% +use is actually just some data inside of +their section so you don't actually care + + align:start position:0% +their section so you don't actually care + + + align:start position:0% +their section so you don't actually care +well the native client runtime doesn't + + align:start position:0% +well the native client runtime doesn't + + + align:start position:0% +well the native client runtime doesn't +care whether this guy screws up their + + align:start position:0% +care whether this guy screws up their + + + align:start position:0% +care whether this guy screws up their +stack overflows their stack or what but + + align:start position:0% +stack overflows their stack or what but + + + align:start position:0% +stack overflows their stack or what but +but you can put anything on the stack + + align:start position:0% +but you can put anything on the stack + + + align:start position:0% +but you can put anything on the stack +and when you return you jump for that + + align:start position:0% +and when you return you jump for that + + + align:start position:0% +and when you return you jump for that +that's true yeah so return is almost + + align:start position:0% +that's true yeah so return is almost + + + align:start position:0% +that's true yeah so return is almost +like an indirect jump from a particular + + align:start position:0% +like an indirect jump from a particular + + + align:start position:0% +like an indirect jump from a particular +weird memory location that's the top of + + align:start position:0% +weird memory location that's the top of + + + align:start position:0% +weird memory location that's the top of +the stack so I guess one thing they + + align:start position:0% +the stack so I guess one thing they + + + align:start position:0% +the stack so I guess one thing they +could do for returns is maybe prefix it + + align:start position:0% +could do for returns is maybe prefix it + + + align:start position:0% +could do for returns is maybe prefix it +with a similar check where maybe you + + align:start position:0% +with a similar check where maybe you + + + align:start position:0% +with a similar check where maybe you +like pop the top thing of the stack you + + align:start position:0% +like pop the top thing of the stack you + + + align:start position:0% +like pop the top thing of the stack you +check whether it's valid and then you WR + + align:start position:0% +check whether it's valid and then you WR + + + align:start position:0% +check whether it's valid and then you WR +maybe you somehow do an and to a memory + + align:start position:0% +maybe you somehow do an and to a memory + + + align:start position:0% +maybe you somehow do an and to a memory +oper and that's the top of the stack um + + align:start position:0% +oper and that's the top of the stack um + + + align:start position:0% +oper and that's the top of the stack um +that seems a little fragile um partly + + align:start position:0% +that seems a little fragile um partly + + + align:start position:0% +that seems a little fragile um partly +because of race conditions because for + + align:start position:0% +because of race conditions because for + + + align:start position:0% +because of race conditions because for +example if you look at the top location + + align:start position:0% +example if you look at the top location + + + align:start position:0% +example if you look at the top location +on a stack and you check that it's okay + + align:start position:0% +on a stack and you check that it's okay + + + align:start position:0% +on a stack and you check that it's okay +and then you do a r later another thread + + align:start position:0% +and then you do a r later another thread + + + align:start position:0% +and then you do a r later another thread +in the same module could modify the + + align:start position:0% +in the same module could modify the + + + align:start position:0% +in the same module could modify the +thing at the top of the stack uh and + + align:start position:0% +thing at the top of the stack uh and + + + align:start position:0% +thing at the top of the stack uh and +then you would be returning to a bad + + align:start position:0% +then you would be returning to a bad + + + align:start position:0% +then you would be returning to a bad +address could this not be the case with + + align:start position:0% +address could this not be the case with + + + align:start position:0% +address could this not be the case with +the jumps as well yeah so what happens + + align:start position:0% +the jumps as well yeah so what happens + + + align:start position:0% +the jumps as well yeah so what happens +with a jump could a race condition + + align:start position:0% +with a jump could a race condition + + + align:start position:0% +with a jump could a race condition +somehow invalidate this + + align:start position:0% + + + + align:start position:0% + +check yeah notable well so the code is + + align:start position:0% +check yeah notable well so the code is + + + align:start position:0% +check yeah notable well so the code is +not writable that's true so you can't + + align:start position:0% +not writable that's true so you can't + + + align:start position:0% +not writable that's true so you can't +modify the and but could another thread + + align:start position:0% +modify the and but could another thread + + + align:start position:0% +modify the and but could another thread +modify this jump Target in between these + + align:start position:0% +modify this jump Target in between these + + + align:start position:0% +modify this jump Target in between these +two instructions + + align:start position:0% +two instructions + + + align:start position:0% +two instructions +yeah yeah so that's the cool thing there + + align:start position:0% +yeah yeah so that's the cool thing there + + + align:start position:0% +yeah yeah so that's the cool thing there +there's basically well if if it modifies + + align:start position:0% +there's basically well if if it modifies + + + align:start position:0% +there's basically well if if it modifies +it in memory or wherever it loaded into + + align:start position:0% +it in memory or wherever it loaded into + + + align:start position:0% +it in memory or wherever it loaded into +E from sure it could do it before you + + align:start position:0% +E from sure it could do it before you + + + align:start position:0% +E from sure it could do it before you +load in which case this e will be bad + + align:start position:0% +load in which case this e will be bad + + + align:start position:0% +load in which case this e will be bad +but then will clear the bad bits or it + + align:start position:0% +but then will clear the bad bits or it + + + align:start position:0% +but then will clear the bad bits or it +could modify it after at which point + + align:start position:0% +could modify it after at which point + + + align:start position:0% +could modify it after at which point +it's already in eex so it doesn't matter + + align:start position:0% +it's already in eex so it doesn't matter + + + align:start position:0% +it's already in eex so it doesn't matter +that it's modifying the memory location + + align:start position:0% +that it's modifying the memory location + + + align:start position:0% +that it's modifying the memory location +from which the E register was + + align:start position:0% +from which the E register was + + + align:start position:0% +from which the E register was +loaded and threads don't actually share + + align:start position:0% +loaded and threads don't actually share + + + align:start position:0% +loaded and threads don't actually share +the register sets so if another thread + + align:start position:0% +the register sets so if another thread + + + align:start position:0% +the register sets so if another thread +modifies the eax register it will not + + align:start position:0% +modifies the eax register it will not + + + align:start position:0% +modifies the eax register it will not +affect this thread's eax register so + + align:start position:0% +affect this thread's eax register so + + + align:start position:0% +affect this thread's eax register so +this instruction actually is sort of + + align:start position:0% +this instruction actually is sort of + + + align:start position:0% +this instruction actually is sort of +race proof in some sense other threads + + align:start position:0% +race proof in some sense other threads + + + align:start position:0% +race proof in some sense other threads +can't invalidate this instruction + + align:start position:0% +can't invalidate this instruction + + + align:start position:0% +can't invalidate this instruction +sequence make + + align:start position:0% +sequence make + + + align:start position:0% +sequence make +sense all right so here's another + + align:start position:0% +sense all right so here's another + + + align:start position:0% +sense all right so here's another +interesting question + + align:start position:0% +interesting question + + + align:start position:0% +interesting question +um could we bypass this and like I can + + align:start position:0% +um could we bypass this and like I can + + + align:start position:0% +um could we bypass this and like I can +jump around on this address space all I + + align:start position:0% +jump around on this address space all I + + + align:start position:0% +jump around on this address space all I +want and when I'm disassembling this + + align:start position:0% +want and when I'm disassembling this + + + align:start position:0% +want and when I'm disassembling this +instruction this seems like a perfectly + + align:start position:0% +instruction this seems like a perfectly + + + align:start position:0% +instruction this seems like a perfectly +fine pair of instructions an and and a + + align:start position:0% +fine pair of instructions an and and a + + + align:start position:0% +fine pair of instructions an and and a +jump and the check for + + align:start position:0% +jump and the check for + + + align:start position:0% +jump and the check for +static jumps is that well it just has to + + align:start position:0% +static jumps is that well it just has to + + + align:start position:0% +static jumps is that well it just has to +point to some Target that was seen so + + align:start position:0% +point to some Target that was seen so + + + align:start position:0% +point to some Target that was seen so +yeah we saw an end that's one + + align:start position:0% +yeah we saw an end that's one + + + align:start position:0% +yeah we saw an end that's one +instruction that's valid we saw a jump + + align:start position:0% +instruction that's valid we saw a jump + + + align:start position:0% +instruction that's valid we saw a jump +that's another valid instruction so when + + align:start position:0% +that's another valid instruction so when + + + align:start position:0% +that's another valid instruction so when +I see a direct jump up here maybe I you + + align:start position:0% +I see a direct jump up here maybe I you + + + align:start position:0% +I see a direct jump up here maybe I you +know jump to some address I don't know 1 + + align:start position:0% +know jump to some address I don't know 1 + + + align:start position:0% +know jump to some address I don't know 1 +2 3 + + align:start position:0% +2 3 + + + align:start position:0% +2 3 +7 that's actually okay even though it's + + align:start position:0% +7 that's actually okay even though it's + + + align:start position:0% +7 that's actually okay even though it's +not a multiple of 32 native client + + align:start position:0% +not a multiple of 32 native client + + + align:start position:0% +not a multiple of 32 native client +doesn't General allow direct jumps to + + align:start position:0% +doesn't General allow direct jumps to + + + align:start position:0% +doesn't General allow direct jumps to +arbitrary addresses as long as that + + align:start position:0% +arbitrary addresses as long as that + + + align:start position:0% +arbitrary addresses as long as that +address is a instruction that we saw + + align:start position:0% +address is a instruction that we saw + + + align:start position:0% +address is a instruction that we saw +during this assembly as we were just + + align:start position:0% +during this assembly as we were just + + + align:start position:0% +during this assembly as we were just +talking + + align:start position:0% +talking + + + align:start position:0% +talking +about so could I put in this very nicely + + align:start position:0% +about so could I put in this very nicely + + + align:start position:0% +about so could I put in this very nicely +checked indirect jump and then later on + + align:start position:0% +checked indirect jump and then later on + + + align:start position:0% +checked indirect jump and then later on +in the code jump to the second + + align:start position:0% +in the code jump to the second + + + align:start position:0% +in the code jump to the second +instruction in that sequence so then + + align:start position:0% +instruction in that sequence so then + + + align:start position:0% +instruction in that sequence so then +I'll load something into e jump here and + + align:start position:0% +I'll load something into e jump here and + + + align:start position:0% +I'll load something into e jump here and +then directly jump into this unsandboxed + + align:start position:0% + + + + align:start position:0% + +address so that would violate the + + align:start position:0% +address so that would violate the + + + align:start position:0% +address so that would violate the +security right did everyone see that so + + align:start position:0% +security right did everyone see that so + + + align:start position:0% +security right did everyone see that so +how how is this avoided well the any + + align:start position:0% +how how is this avoided well the any + + + align:start position:0% +how how is this avoided well the any +should and jump as a single instruction + + align:start position:0% +should and jump as a single instruction + + + align:start position:0% +should and jump as a single instruction +yeah so this is why they call this thing + + align:start position:0% +yeah so this is why they call this thing + + + align:start position:0% +yeah so this is why they call this thing +a single pseudo + + align:start position:0% +a single pseudo + + + align:start position:0% +a single pseudo +instruction and even though at the x86 + + align:start position:0% +instruction and even though at the x86 + + + align:start position:0% +instruction and even though at the x86 +level they're actually distinct + + align:start position:0% +level they're actually distinct + + + align:start position:0% +level they're actually distinct +instruction as far as the knal validator + + align:start position:0% +instruction as far as the knal validator + + + align:start position:0% +instruction as far as the knal validator +thinks of it it's actually a single + + align:start position:0% +thinks of it it's actually a single + + + align:start position:0% +thinks of it it's actually a single +Atomic unit so as far as this check for + + align:start position:0% +Atomic unit so as far as this check for + + + align:start position:0% +Atomic unit so as far as this check for +whether it's an instruction that you saw + + align:start position:0% +whether it's an instruction that you saw + + + align:start position:0% +whether it's an instruction that you saw +before they think oh this is the only + + align:start position:0% +before they think oh this is the only + + + align:start position:0% +before they think oh this is the only +instruction that I saw before jumping in + + align:start position:0% +instruction that I saw before jumping in + + + align:start position:0% +instruction that I saw before jumping in +the middle it's like jumping in the + + align:start position:0% +the middle it's like jumping in the + + + align:start position:0% +the middle it's like jumping in the +middle of this guy it's the same thing + + align:start position:0% +middle of this guy it's the same thing + + + align:start position:0% +middle of this guy it's the same thing +so they basically enfor slightly + + align:start position:0% +so they basically enfor slightly + + + align:start position:0% +so they basically enfor slightly +different semantics than what x86 + + align:start position:0% +different semantics than what x86 + + + align:start position:0% +different semantics than what x86 +enforces in terms of what an instruction + + align:start position:0% +enforces in terms of what an instruction + + + align:start position:0% +enforces in terms of what an instruction +is and this might actually mean that you + + align:start position:0% +is and this might actually mean that you + + + align:start position:0% +is and this might actually mean that you +can't represent certain instruction + + align:start position:0% +can't represent certain instruction + + + align:start position:0% +can't represent certain instruction +sequences in knle so you know if you + + align:start position:0% +sequences in knle so you know if you + + + align:start position:0% +sequences in knle so you know if you +actually had legitimate code that looked + + align:start position:0% +actually had legitimate code that looked + + + align:start position:0% +actually had legitimate code that looked +like this + + align:start position:0% +like this + + + align:start position:0% +like this +before this is going to be turned into a + + align:start position:0% +before this is going to be turned into a + + + align:start position:0% +before this is going to be turned into a +single op code and knle but hopefully + + align:start position:0% +single op code and knle but hopefully + + + align:start position:0% +single op code and knle but hopefully +that's not a problem yeah presumably + + align:start position:0% +that's not a problem yeah presumably + + + align:start position:0% +that's not a problem yeah presumably +they could put that in the the trusted + + align:start position:0% +they could put that in the the trusted + + + align:start position:0% +they could put that in the the trusted +codebase in the start of the the text + + align:start position:0% +codebase in the start of the the text + + + align:start position:0% +codebase in the start of the the text +segment because that way all you would + + align:start position:0% +segment because that way all you would + + + align:start position:0% +segment because that way all you would +always replace those two instead of + + align:start position:0% +always replace those two instead of + + + align:start position:0% +always replace those two instead of +putting those in the binary that you + + align:start position:0% +putting those in the binary that you + + + align:start position:0% +putting those in the binary that you +produce anyway you just jump straight to + + align:start position:0% +produce anyway you just jump straight to + + + align:start position:0% +produce anyway you just jump straight to +that jump Target that's in the + + align:start position:0% +that jump Target that's in the + + + align:start position:0% +that jump Target that's in the +privileged section in this trusted run + + align:start position:0% +privileged section in this trusted run + + + align:start position:0% +privileged section in this trusted run +time you mean or something no so in the + + align:start position:0% +time you mean or something no so in the + + + align:start position:0% +time you mean or something no so in the +the first 64k the yeah they have these + + align:start position:0% +the first 64k the yeah they have these + + + align:start position:0% +the first 64k the yeah they have these +trampolines and yeah right so they could + + align:start position:0% +trampolines and yeah right so they could + + + align:start position:0% +trampolines and yeah right so they could +make that one of the trampolines except + + align:start position:0% +make that one of the trampolines except + + + align:start position:0% +make that one of the trampolines except +that it doesn't jump out it jumps back + + align:start position:0% +that it doesn't jump out it jumps back + + + align:start position:0% +that it doesn't jump out it jumps back +in so that way the it wouldn't need to + + align:start position:0% +in so that way the it wouldn't need to + + + align:start position:0% +in so that way the it wouldn't need to +be a superu it just be a single x86 jump + + align:start position:0% +be a superu it just be a single x86 jump + + + align:start position:0% +be a superu it just be a single x86 jump +into there which would then jump out + + align:start position:0% +into there which would then jump out + + + align:start position:0% +into there which would then jump out +that's true yeah so so that's another + + align:start position:0% +that's true yeah so so that's another + + + align:start position:0% +that's true yeah so so that's another +sort of clever solution that you could + + align:start position:0% +sort of clever solution that you could + + + align:start position:0% +sort of clever solution that you could +do is instead so does everyone sort of + + align:start position:0% +do is instead so does everyone sort of + + + align:start position:0% +do is instead so does everyone sort of +see what what the plan is so suppose + + align:start position:0% +see what what the plan is so suppose + + + align:start position:0% +see what what the plan is so suppose +that you didn't want to do this pseudo + + align:start position:0% +that you didn't want to do this pseudo + + + align:start position:0% +that you didn't want to do this pseudo +instruction trick and you just wanted to + + align:start position:0% +instruction trick and you just wanted to + + + align:start position:0% +instruction trick and you just wanted to +have a single instruction replacing the + + align:start position:0% +have a single instruction replacing the + + + align:start position:0% +have a single instruction replacing the +jump eax well what you could basically + + align:start position:0% +jump eax well what you could basically + + + align:start position:0% +jump eax well what you could basically +come up with is a library of all + + align:start position:0% +come up with is a library of all + + + align:start position:0% +come up with is a library of all +possible indirect jumps you could ever + + align:start position:0% +possible indirect jumps you could ever + + + align:start position:0% +possible indirect jumps you could ever +do so like well there's jump + + align:start position:0% +do so like well there's jump + + + align:start position:0% +do so like well there's jump +eax there's jump ebx and so on and you + + align:start position:0% +eax there's jump ebx and so on and you + + + align:start position:0% +eax there's jump ebx and so on and you +would construct a library of these guys + + align:start position:0% +would construct a library of these guys + + + align:start position:0% +would construct a library of these guys +for each of them you would construct the + + align:start position:0% +for each of them you would construct the + + + align:start position:0% +for each of them you would construct the +safe check that you want to replace them + + align:start position:0% +safe check that you want to replace them + + + align:start position:0% +safe check that you want to replace them +with so for this one you would put an + + align:start position:0% +with so for this one you would put an + + + align:start position:0% +with so for this one you would put an +and in front of it and so on for this + + align:start position:0% +and in front of it and so on for this + + + align:start position:0% +and in front of it and so on for this +one You' also put an end in front of it + + align:start position:0% +one You' also put an end in front of it + + + align:start position:0% +one You' also put an end in front of it +and so on and then in the compiled + + align:start position:0% +and so on and then in the compiled + + + align:start position:0% +and so on and then in the compiled +binary every time you want to jump to + + align:start position:0% +binary every time you want to jump to + + + align:start position:0% +binary every time you want to jump to +eax what you actually do is you actually + + align:start position:0% +eax what you actually do is you actually + + + align:start position:0% +eax what you actually do is you actually +jump to a fixed address that corresponds + + align:start position:0% +jump to a fixed address that corresponds + + + align:start position:0% +jump to a fixed address that corresponds +to this helpful piece of code stored + + align:start position:0% +to this helpful piece of code stored + + + align:start position:0% +to this helpful piece of code stored +somewhere in that low 64k of the program + + align:start position:0% +somewhere in that low 64k of the program + + + align:start position:0% +somewhere in that low 64k of the program +and then this guy will do the end and + + align:start position:0% +and then this guy will do the end and + + + align:start position:0% +and then this guy will do the end and +jump again the reason that they probably + + align:start position:0% +jump again the reason that they probably + + + align:start position:0% +jump again the reason that they probably +don't do this is performance for this + + align:start position:0% +don't do this is performance for this + + + align:start position:0% +don't do this is performance for this +sort of interesting reason so the Intel + + align:start position:0% +sort of interesting reason so the Intel + + + align:start position:0% +sort of interesting reason so the Intel +processor and actually most processors + + align:start position:0% +processor and actually most processors + + + align:start position:0% +processor and actually most processors +these days um + + align:start position:0% +these days um + + + align:start position:0% +these days um +have have to predict where the Branch + + align:start position:0% +have have to predict where the Branch + + + align:start position:0% +have have to predict where the Branch +goes to keep the pipeline of the + + align:start position:0% +goes to keep the pipeline of the + + + align:start position:0% +goes to keep the pipeline of the +processor full at all times so there's a + + align:start position:0% +processor full at all times so there's a + + + align:start position:0% +processor full at all times so there's a +really complicated Branch predictor that + + align:start position:0% +really complicated Branch predictor that + + + align:start position:0% +really complicated Branch predictor that +not only decides whether you're going to + + align:start position:0% +not only decides whether you're going to + + + align:start position:0% +not only decides whether you're going to +Branch or not like if statements but it + + align:start position:0% +Branch or not like if statements but it + + + align:start position:0% +Branch or not like if statements but it +also actually guesses where you're going + + align:start position:0% +also actually guesses where you're going + + + align:start position:0% +also actually guesses where you're going +to jump so if you see an indirect jump + + align:start position:0% +to jump so if you see an indirect jump + + + align:start position:0% +to jump so if you see an indirect jump +it actually is going to guess what the + + align:start position:0% +it actually is going to guess what the + + + align:start position:0% +it actually is going to guess what the +address is going to be and this is + + align:start position:0% +address is going to be and this is + + + align:start position:0% +address is going to be and this is +actually a guess that's stored per cach + + align:start position:0% +actually a guess that's stored per cach + + + align:start position:0% +actually a guess that's stored per cach +line storing the jump instruction so if + + align:start position:0% +line storing the jump instruction so if + + + align:start position:0% +line storing the jump instruction so if +you have a single place where all the + + align:start position:0% +you have a single place where all the + + + align:start position:0% +you have a single place where all the +jump EXs come from then the CPU is + + align:start position:0% +jump EXs come from then the CPU is + + + align:start position:0% +jump EXs come from then the CPU is +always going to be very confused because + + align:start position:0% +always going to be very confused because + + + align:start position:0% +always going to be very confused because +these jump EXs seem to be going all over + + align:start position:0% +these jump EXs seem to be going all over + + + align:start position:0% +these jump EXs seem to be going all over +the place everywhere whereas if you + + align:start position:0% +the place everywhere whereas if you + + + align:start position:0% +the place everywhere whereas if you +really tie to a particular jump + + align:start position:0% +really tie to a particular jump + + + align:start position:0% +really tie to a particular jump +instruction it'll be a better prediction + + align:start position:0% +instruction it'll be a better prediction + + + align:start position:0% +instruction it'll be a better prediction +but that's just a sort of performance uh + + align:start position:0% +but that's just a sort of performance uh + + + align:start position:0% +but that's just a sort of performance uh +trick that they play make + + align:start position:0% +trick that they play make + + + align:start position:0% +trick that they play make +sense all right + + align:start position:0% +sense all right + + + align:start position:0% +sense all right +so so I guess we roughly understand how + + align:start position:0% +so so I guess we roughly understand how + + + align:start position:0% +so so I guess we roughly understand how +it's going to disassemble all the + + align:start position:0% +it's going to disassemble all the + + + align:start position:0% +it's going to disassemble all the +instructions how it's going to prevent + + align:start position:0% +instructions how it's going to prevent + + + align:start position:0% +instructions how it's going to prevent +these instructions so now let's look at + + align:start position:0% +these instructions so now let's look at + + + align:start position:0% +these instructions so now let's look at +the set of rules they are going to + + align:start position:0% +the set of rules they are going to + + + align:start position:0% +the set of rules they are going to +enforce so there's this table in the + + align:start position:0% +enforce so there's this table in the + + + align:start position:0% +enforce so there's this table in the +paper table one that has all these + + align:start position:0% +paper table one that has all these + + + align:start position:0% +paper table one that has all these +different rules for the validator to + + align:start position:0% +different rules for the validator to + + + align:start position:0% +different rules for the validator to +follow or that the binaries have to + + align:start position:0% +follow or that the binaries have to + + + align:start position:0% +follow or that the binaries have to +follow and the validator checks so let's + + align:start position:0% +follow and the validator checks so let's + + + align:start position:0% +follow and the validator checks so let's +go through these rules and just double + + align:start position:0% +go through these rules and just double + + + align:start position:0% +go through these rules and just double +check that we understand why all of + + align:start position:0% +check that we understand why all of + + + align:start position:0% +check that we understand why all of +these rules are there so so they have + + align:start position:0% +these rules are there so so they have + + + align:start position:0% +these rules are there so so they have +these things C1 all the way to + + align:start position:0% +these things C1 all the way to + + + align:start position:0% +these things C1 all the way to +C7 so C1 basically says that once you + + align:start position:0% +C7 so C1 basically says that once you + + + align:start position:0% +C7 so C1 basically says that once you +load the binary in memory then the + + align:start position:0% +load the binary in memory then the + + + align:start position:0% +load the binary in memory then the +binary is actually not + + align:start position:0% + + + + align:start position:0% + +writable at the page table level so they + + align:start position:0% +writable at the page table level so they + + + align:start position:0% +writable at the page table level so they +map they set the permission bits for the + + align:start position:0% +map they set the permission bits for the + + + align:start position:0% +map they set the permission bits for the +binary to be non-writable so + + align:start position:0% +binary to be non-writable so + + + align:start position:0% +binary to be non-writable so +why should be fairly obvious + + align:start position:0% +why should be fairly obvious + + + align:start position:0% +why should be fairly obvious +hopefully so I guess the the the reason + + align:start position:0% +hopefully so I guess the the the reason + + + align:start position:0% +hopefully so I guess the the the reason +is that their whole security plan relies + + align:start position:0% +is that their whole security plan relies + + + align:start position:0% +is that their whole security plan relies +on them checking that your binary is + + align:start position:0% +on them checking that your binary is + + + align:start position:0% +on them checking that your binary is +correct so once they've checked it they + + align:start position:0% +correct so once they've checked it they + + + align:start position:0% +correct so once they've checked it they +want to make sure you can't modify the + + align:start position:0% +want to make sure you can't modify the + + + align:start position:0% +want to make sure you can't modify the +binary and have it do something illegal + + align:start position:0% +binary and have it do something illegal + + + align:start position:0% +binary and have it do something illegal +uh that they prohibited so this is I + + align:start position:0% +uh that they prohibited so this is I + + + align:start position:0% +uh that they prohibited so this is I +think reasonably clear then so C2 is + + align:start position:0% +think reasonably clear then so C2 is + + + align:start position:0% +think reasonably clear then so C2 is +their plan that basically has to you + + align:start position:0% +their plan that basically has to you + + + align:start position:0% +their plan that basically has to you +know linked at zero and start at 64k so + + align:start position:0% +know linked at zero and start at 64k so + + + align:start position:0% +know linked at zero and start at 64k so +this requirement I think doesn't + + align:start position:0% +this requirement I think doesn't + + + align:start position:0% +this requirement I think doesn't +actually have to do with security so + + align:start position:0% +actually have to do with security so + + + align:start position:0% +actually have to do with security so +much I think it's just for convenience + + align:start position:0% +much I think it's just for convenience + + + align:start position:0% +much I think it's just for convenience +because they just want to have a + + align:start position:0% +because they just want to have a + + + align:start position:0% +because they just want to have a +standard layout for the program in some + + align:start position:0% +standard layout for the program in some + + + align:start position:0% +standard layout for the program in some +sense it's for simp licity so that they + + align:start position:0% +sense it's for simp licity so that they + + + align:start position:0% +sense it's for simp licity so that they +don't have to deal with complicated + + align:start position:0% +don't have to deal with complicated + + + align:start position:0% +don't have to deal with complicated +relocation records which means that + + align:start position:0% +relocation records which means that + + + align:start position:0% +relocation records which means that +there's fewer things that the validator + + align:start position:0% +there's fewer things that the validator + + + align:start position:0% +there's fewer things that the validator +or loader would might screw up but + + align:start position:0% +or loader would might screw up but + + + align:start position:0% +or loader would might screw up but +basically this is a sort of a + + align:start position:0% +basically this is a sort of a + + + align:start position:0% +basically this is a sort of a +standardization plan for them in terms + + align:start position:0% +standardization plan for them in terms + + + align:start position:0% +standardization plan for them in terms +of how to load their um executable make + + align:start position:0% +of how to load their um executable make + + + align:start position:0% +of how to load their um executable make +sense all right so the third requirement + + align:start position:0% +sense all right so the third requirement + + + align:start position:0% +sense all right so the third requirement +um is that I guess their + + align:start position:0% +um is that I guess their + + + align:start position:0% +um is that I guess their +indirect + + align:start position:0% +indirect + + + align:start position:0% +indirect +jumps use the Pudo + + align:start position:0% + + + + align:start position:0% + +instruction so the the Pudo instruction + + align:start position:0% +instruction so the the Pudo instruction + + + align:start position:0% +instruction so the the Pudo instruction +is this thing above so that we just + + align:start position:0% +is this thing above so that we just + + + align:start position:0% +is this thing above so that we just +talked about why it needs to ensure this + + align:start position:0% +talked about why it needs to ensure this + + + align:start position:0% +talked about why it needs to ensure this +so that you don't jump to the middle of + + align:start position:0% +so that you don't jump to the middle of + + + align:start position:0% +so that you don't jump to the middle of +some instruction or sort of somehow + + align:start position:0% +some instruction or sort of somehow + + + align:start position:0% +some instruction or sort of somehow +invoke you know CIS Call Etc make + + align:start position:0% +invoke you know CIS Call Etc make + + + align:start position:0% +invoke you know CIS Call Etc make +sense all right so what's going on with + + align:start position:0% +sense all right so what's going on with + + + align:start position:0% +sense all right so what's going on with +C4 so basically you have to pad + + align:start position:0% +C4 so basically you have to pad + + + align:start position:0% +C4 so basically you have to pad +out to page + + align:start position:0% + + + + align:start position:0% + +boundary with a halt + + align:start position:0% +boundary with a halt + + + align:start position:0% +boundary with a halt +instruction why do they want to pad + + align:start position:0% +instruction why do they want to pad + + + align:start position:0% +instruction why do they want to pad +their binary out with + + align:start position:0% + + + + align:start position:0% + +halts any + + align:start position:0% +halts any + + + align:start position:0% +halts any +ideas yeah maybe + + align:start position:0% +ideas yeah maybe + + + align:start position:0% +ideas yeah maybe +like like + + align:start position:0% + + + + align:start position:0% + +instead yeah I think um so I I I don't + + align:start position:0% +instead yeah I think um so I I I don't + + + align:start position:0% +instead yeah I think um so I I I don't +actually I have to admit I don't have a + + align:start position:0% +actually I have to admit I don't have a + + + align:start position:0% +actually I have to admit I don't have a +crisp answer for why C4 exists but I + + align:start position:0% +crisp answer for why C4 exists but I + + + align:start position:0% +crisp answer for why C4 exists but I +think it's roughly what you're saying + + align:start position:0% +think it's roughly what you're saying + + + align:start position:0% +think it's roughly what you're saying +which is that if you well this code + + align:start position:0% +which is that if you well this code + + + align:start position:0% +which is that if you well this code +module stops at some point there's some + + align:start position:0% +module stops at some point there's some + + + align:start position:0% +module stops at some point there's some +end to it and the question is what + + align:start position:0% +end to it and the question is what + + + align:start position:0% +end to it and the question is what +happens when when you just keep + + align:start position:0% +happens when when you just keep + + + align:start position:0% +happens when when you just keep +executing and you get to the end then + + align:start position:0% +executing and you get to the end then + + + align:start position:0% +executing and you get to the end then +the processor might just keep executing + + align:start position:0% +the processor might just keep executing + + + align:start position:0% +the processor might just keep executing +past the end and execute some extra + + align:start position:0% +past the end and execute some extra + + + align:start position:0% +past the end and execute some extra +instructions or maybe it wraps around in + + align:start position:0% +instructions or maybe it wraps around in + + + align:start position:0% +instructions or maybe it wraps around in +some weird way so they just want to make + + align:start position:0% +some weird way so they just want to make + + + align:start position:0% +some weird way so they just want to make +sure that there's no ambiguity about + + align:start position:0% +sure that there's no ambiguity about + + + align:start position:0% +sure that there's no ambiguity about +what happens if you keep running and you + + align:start position:0% +what happens if you keep running and you + + + align:start position:0% +what happens if you keep running and you +don't jump and you just run off the end + + align:start position:0% +don't jump and you just run off the end + + + align:start position:0% +don't jump and you just run off the end +of the instruction Stream So this just + + align:start position:0% +of the instruction Stream So this just + + + align:start position:0% +of the instruction Stream So this just +make sure that the only answer there is + + align:start position:0% +make sure that the only answer there is + + + align:start position:0% +make sure that the only answer there is +if you keep executing you'll Halt and + + align:start position:0% +if you keep executing you'll Halt and + + + align:start position:0% +if you keep executing you'll Halt and +that'll trap into the runtime and you'll + + align:start position:0% +that'll trap into the runtime and you'll + + + align:start position:0% +that'll trap into the runtime and you'll +terminate the module so think it's just + + align:start position:0% +terminate the module so think it's just + + + align:start position:0% +terminate the module so think it's just +sort of a Simplicity safety guarantee + + align:start position:0% +sort of a Simplicity safety guarantee + + + align:start position:0% +sort of a Simplicity safety guarantee +there uh I don't think there's a + + align:start position:0% +there uh I don't think there's a + + + align:start position:0% +there uh I don't think there's a +concrete attack that I could at least + + align:start position:0% +concrete attack that I could at least + + + align:start position:0% +concrete attack that I could at least +construct in my + + align:start position:0% + + + + align:start position:0% + +head yeah but uh here's the thing you + + align:start position:0% +head yeah but uh here's the thing you + + + align:start position:0% +head yeah but uh here's the thing you +can't jump past the end so the last + + align:start position:0% +can't jump past the end so the last + + + align:start position:0% +can't jump past the end so the last +thing that you could jump to is the last + + align:start position:0% +thing that you could jump to is the last + + + align:start position:0% +thing that you could jump to is the last +instruction and by this rule that + + align:start position:0% +instruction and by this rule that + + + align:start position:0% +instruction and by this rule that +instruction must be halt so you could + + align:start position:0% +instruction must be halt so you could + + + align:start position:0% +instruction must be halt so you could +jump to the halt but then you'll + + align:start position:0% +jump to the halt but then you'll + + + align:start position:0% +jump to the halt but then you'll +immediately Halt and you won't ran past + + align:start position:0% +immediately Halt and you won't ran past + + + align:start position:0% +immediately Halt and you won't ran past +past the end either so I think it's just + + align:start position:0% +past the end either so I think it's just + + + align:start position:0% +past the end either so I think it's just +sort of a cleanliness uh as far as I + + align:start position:0% +sort of a cleanliness uh as far as I + + + align:start position:0% +sort of a cleanliness uh as far as I +could tell again guante for them to make + + align:start position:0% +could tell again guante for them to make + + + align:start position:0% +could tell again guante for them to make +sure that there's no weirdness in terms + + align:start position:0% +sure that there's no weirdness in terms + + + align:start position:0% +sure that there's no weirdness in terms +of wrap around at the + + align:start position:0% +of wrap around at the + + + align:start position:0% +of wrap around at the +edges all right so then the the C5 is + + align:start position:0% +edges all right so then the the C5 is + + + align:start position:0% +edges all right so then the the C5 is +basically no + + align:start position:0% +basically no + + + align:start position:0% +basically no +instructions that span the 32bit bound + + align:start position:0% +instructions that span the 32bit bound + + + align:start position:0% +instructions that span the 32bit bound +the 32 byte + + align:start position:0% +the 32 byte + + + align:start position:0% +the 32 byte +boundary so this is sort of a variant of + + align:start position:0% +boundary so this is sort of a variant of + + + align:start position:0% +boundary so this is sort of a variant of +this rule that we talked about before + + align:start position:0% +this rule that we talked about before + + + align:start position:0% +this rule that we talked about before +where every uh multiple of 32 must be a + + align:start position:0% +where every uh multiple of 32 must be a + + + align:start position:0% +where every uh multiple of 32 must be a +valid instruction that we saw during + + align:start position:0% +valid instruction that we saw during + + + align:start position:0% +valid instruction that we saw during +disassembly so otherwise we'll jump to + + align:start position:0% +disassembly so otherwise we'll jump to + + + align:start position:0% +disassembly so otherwise we'll jump to +the middle of an instruction and have + + align:start position:0% +the middle of an instruction and have + + + align:start position:0% +the middle of an instruction and have +the problem with that csol that might be + + align:start position:0% +the problem with that csol that might be + + + align:start position:0% +the problem with that csol that might be +hidden + + align:start position:0% +hidden + + + align:start position:0% +hidden +there okay and then we have C6 which is + + align:start position:0% +there okay and then we have C6 which is + + + align:start position:0% +there okay and then we have C6 which is +basically all + + align:start position:0% +basically all + + + align:start position:0% +basically all +instructions + + align:start position:0% +instructions + + + align:start position:0% +instructions +reachable by + + align:start position:0% +reachable by + + + align:start position:0% +reachable by +disassembly from the start so this + + align:start position:0% +disassembly from the start so this + + + align:start position:0% +disassembly from the start so this +ensures that we see every instruction we + + align:start position:0% +ensures that we see every instruction we + + + align:start position:0% +ensures that we see every instruction we +can check every instruction that can + + align:start position:0% +can check every instruction that can + + + align:start position:0% +can check every instruction that can +possibly be run at runtime and I guess + + align:start position:0% +possibly be run at runtime and I guess + + + align:start position:0% +possibly be run at runtime and I guess +C7 is this basically all direct jumps + + align:start position:0% + + + + align:start position:0% + +are okay so this is an example of that + + align:start position:0% +are okay so this is an example of that + + + align:start position:0% +are okay so this is an example of that +jump up there where you code in the + + align:start position:0% +jump up there where you code in the + + + align:start position:0% +jump up there where you code in the +Target right away so it doesn't have a + + align:start position:0% +Target right away so it doesn't have a + + + align:start position:0% +Target right away so it doesn't have a +multiple of 32 but it still has to be a + + align:start position:0% +multiple of 32 but it still has to be a + + + align:start position:0% +multiple of 32 but it still has to be a +valid instruction that we saw during the + + align:start position:0% +valid instruction that we saw during the + + + align:start position:0% +valid instruction that we saw during the +left to right disassembly question + + align:start position:0% +left to right disassembly question + + + align:start position:0% +left to right disassembly question +what's the difference between C5 and + + align:start position:0% +what's the difference between C5 and + + + align:start position:0% +what's the difference between C5 and +C3 yeah so I think C5 says that if I + + align:start position:0% +C3 yeah so I think C5 says that if I + + + align:start position:0% +C3 yeah so I think C5 says that if I +have a instruction that's multiple bytes + + align:start position:0% +have a instruction that's multiple bytes + + + align:start position:0% +have a instruction that's multiple bytes +it cannot uh span that 32 byte boundary + + align:start position:0% +it cannot uh span that 32 byte boundary + + + align:start position:0% +it cannot uh span that 32 byte boundary +so suppose that I have uh you know my + + align:start position:0% +so suppose that I have uh you know my + + + align:start position:0% +so suppose that I have uh you know my +instruction stream and here's you know + + align:start position:0% +instruction stream and here's you know + + + align:start position:0% +instruction stream and here's you know +an address 32 here's address 64 and + + align:start position:0% +an address 32 here's address 64 and + + + align:start position:0% +an address 32 here's address 64 and +maybe I have some sort of an end + + align:start position:0% +maybe I have some sort of an end + + + align:start position:0% +maybe I have some sort of an end +instruction that sort of spans this + + align:start position:0% +instruction that sort of spans this + + + align:start position:0% +instruction that sort of spans this +boundary so this is what C5 prohibits no + + align:start position:0% +boundary so this is what C5 prohibits no + + + align:start position:0% +boundary so this is what C5 prohibits no +instructions can span this boundary + + align:start position:0% +instructions can span this boundary + + + align:start position:0% +instructions can span this boundary +because otherwise we saw this s + + align:start position:0% +because otherwise we saw this s + + + align:start position:0% +because otherwise we saw this s +instruction but because you can always + + align:start position:0% +instruction but because you can always + + + align:start position:0% +instruction but because you can always +jump to 32 by multiples you could jump + + align:start position:0% +jump to 32 by multiples you could jump + + + align:start position:0% +jump to 32 by multiples you could jump +into the middle of the end and who knows + + align:start position:0% +into the middle of the end and who knows + + + align:start position:0% +into the middle of the end and who knows +what will happen there so this is what + + align:start position:0% +what will happen there so this is what + + + align:start position:0% +what will happen there so this is what +C5 prohibits for them and C3 is the sort + + align:start position:0% +C5 prohibits for them and C3 is the sort + + + align:start position:0% +C5 prohibits for them and C3 is the sort +of counterpart to it on the jump side so + + align:start position:0% +of counterpart to it on the jump side so + + + align:start position:0% +of counterpart to it on the jump side so +C3 says that whenever you jump you're + + align:start position:0% +C3 says that whenever you jump you're + + + align:start position:0% +C3 says that whenever you jump you're +going to jump to a multiple of 32 bytes + + align:start position:0% +going to jump to a multiple of 32 bytes + + + align:start position:0% +going to jump to a multiple of 32 bytes +and C5 says that everything you can find + + align:start position:0% +and C5 says that everything you can find + + + align:start position:0% +and C5 says that everything you can find +at a multiple of 32 bytes is a safe + + align:start position:0% +at a multiple of 32 bytes is a safe + + + align:start position:0% +at a multiple of 32 bytes is a safe +instruction I'm wondering if there's any + + align:start position:0% +instruction I'm wondering if there's any + + + align:start position:0% +instruction I'm wondering if there's any +redundancy between some yeah I don't + + align:start position:0% +redundancy between some yeah I don't + + + align:start position:0% +redundancy between some yeah I don't +know I I'm not sure I I had a little bit + + align:start position:0% +know I I'm not sure I I had a little bit + + + align:start position:0% +know I I'm not sure I I had a little bit +of that feeling when reading this list + + align:start position:0% +of that feeling when reading this list + + + align:start position:0% +of that feeling when reading this list +it seems like well they're all good + + align:start position:0% +it seems like well they're all good + + + align:start position:0% +it seems like well they're all good +rules but I'm not sure it's the minimal + + align:start position:0% +rules but I'm not sure it's the minimal + + + align:start position:0% +rules but I'm not sure it's the minimal +non-orthogonal set of or set of + + align:start position:0% +non-orthogonal set of or set of + + + align:start position:0% +non-orthogonal set of or set of +orthogonal rules that that uh um you + + align:start position:0% +orthogonal rules that that uh um you + + + align:start position:0% +orthogonal rules that that uh um you +need to enforce this um but any other + + align:start position:0% +need to enforce this um but any other + + + align:start position:0% +need to enforce this um but any other +questions about the set of restrictions + + align:start position:0% +questions about the set of restrictions + + + align:start position:0% +questions about the set of restrictions +they + + align:start position:0% +they + + + align:start position:0% +they +have all right so I guess let's uh think + + align:start position:0% +have all right so I guess let's uh think + + + align:start position:0% +have all right so I guess let's uh think +about uh this homework question that we + + align:start position:0% +about uh this homework question that we + + + align:start position:0% +about uh this homework question that we +sort of assigned it turns out I think + + align:start position:0% +sort of assigned it turns out I think + + + align:start position:0% +sort of assigned it turns out I think +there was actually a bug that native + + align:start position:0% +there was actually a bug that native + + + align:start position:0% +there was actually a bug that native +client had in its inner sandbox at some + + align:start position:0% +client had in its inner sandbox at some + + + align:start position:0% +client had in its inner sandbox at some +point which is that for some complicated + + align:start position:0% +point which is that for some complicated + + + align:start position:0% +point which is that for some complicated +instruction I believe they didn't have + + align:start position:0% +instruction I believe they didn't have + + + align:start position:0% +instruction I believe they didn't have +the length encoding correctly if I + + align:start position:0% +the length encoding correctly if I + + + align:start position:0% +the length encoding correctly if I +remember properly uh in which case + + align:start position:0% +remember properly uh in which case + + + align:start position:0% +remember properly uh in which case +something bad might happen I don't + + align:start position:0% +something bad might happen I don't + + + align:start position:0% +something bad might happen I don't +remember exactly what the bug was but uh + + align:start position:0% +remember exactly what the bug was but uh + + + align:start position:0% +remember exactly what the bug was but uh +suppose that the inter sandbox validator + + align:start position:0% +suppose that the inter sandbox validator + + + align:start position:0% +suppose that the inter sandbox validator +gets the length of some instruction + + align:start position:0% +gets the length of some instruction + + + align:start position:0% +gets the length of some instruction +wrong what what bad things could happen + + align:start position:0% +wrong what what bad things could happen + + + align:start position:0% +wrong what what bad things could happen +how would you exploit this we can hide + + align:start position:0% +how would you exploit this we can hide + + + align:start position:0% +how would you exploit this we can hide +this call or R and eventually yeah so + + align:start position:0% +this call or R and eventually yeah so + + + align:start position:0% +this call or R and eventually yeah so +suppose that you know there's some you + + align:start position:0% +suppose that you know there's some you + + + align:start position:0% +suppose that you know there's some you +know fancy variant of some and + + align:start position:0% +know fancy variant of some and + + + align:start position:0% +know fancy variant of some and +instruction that you could write down + + align:start position:0% +instruction that you could write down + + + align:start position:0% +instruction that you could write down +and maybe the validator gets that wrong + + align:start position:0% +and maybe the validator gets that wrong + + + align:start position:0% +and maybe the validator gets that wrong +and thinks that ah this guy is actually + + align:start position:0% +and thinks that ah this guy is actually + + + align:start position:0% +and thinks that ah this guy is actually +six bytes when in reality it's five + + align:start position:0% +six bytes when in reality it's five + + + align:start position:0% +six bytes when in reality it's five +bytes long so you could plop this down + + align:start position:0% +bytes long so you could plop this down + + + align:start position:0% +bytes long so you could plop this down +plop this and down and then the + + align:start position:0% +plop this and down and then the + + + align:start position:0% +plop this and down and then the +validator thinks oh it's six bytes so + + align:start position:0% +validator thinks oh it's six bytes so + + + align:start position:0% +validator thinks oh it's six bytes so +I'll look six bytes further and I'll + + align:start position:0% +I'll look six bytes further and I'll + + + align:start position:0% +I'll look six bytes further and I'll +check whether this is a valid + + align:start position:0% +check whether this is a valid + + + align:start position:0% +check whether this is a valid +instruction and we just have to make + + align:start position:0% +instruction and we just have to make + + + align:start position:0% +instruction and we just have to make +sure that whatever is six bytes later + + align:start position:0% +sure that whatever is six bytes later + + + align:start position:0% +sure that whatever is six bytes later +looks like a valid instruction but the + + align:start position:0% +looks like a valid instruction but the + + + align:start position:0% +looks like a valid instruction but the +CPU itself when it runs this code is + + align:start position:0% +CPU itself when it runs this code is + + + align:start position:0% +CPU itself when it runs this code is +going to maybe only look five bytes + + align:start position:0% +going to maybe only look five bytes + + + align:start position:0% +going to maybe only look five bytes +since from the end because that's the + + align:start position:0% +since from the end because that's the + + + align:start position:0% +since from the end because that's the +real length of the instruction so if we + + align:start position:0% +real length of the instruction so if we + + + align:start position:0% +real length of the instruction so if we +can use this extra bite to stick a sisol + + align:start position:0% +can use this extra bite to stick a sisol + + + align:start position:0% +can use this extra bite to stick a sisol +instruction then we could be in business + + align:start position:0% +instruction then we could be in business + + + align:start position:0% +instruction then we could be in business +so if we stick that you know remember + + align:start position:0% +so if we stick that you know remember + + + align:start position:0% +so if we stick that you know remember +from that example above on x86 Ox CD is + + align:start position:0% +from that example above on x86 Ox CD is + + + align:start position:0% +from that example above on x86 Ox CD is +how you make an in instruction so if we + + align:start position:0% +how you make an in instruction so if we + + + align:start position:0% +how you make an in instruction so if we +stick a CD bite at the end of that and + + align:start position:0% +stick a CD bite at the end of that and + + + align:start position:0% +stick a CD bite at the end of that and +then maybe we can put something here + + align:start position:0% +then maybe we can put something here + + + align:start position:0% +then maybe we can put something here +that looks like an instruction but + + align:start position:0% +that looks like an instruction but + + + align:start position:0% +that looks like an instruction but +actually is going to be part of the in + + align:start position:0% +actually is going to be part of the in + + + align:start position:0% +actually is going to be part of the in +instruction here and then we could all + + align:start position:0% +instruction here and then we could all + + + align:start position:0% +instruction here and then we could all +of a sudden make a CIS call and escape + + align:start position:0% +of a sudden make a CIS call and escape + + + align:start position:0% +of a sudden make a CIS call and escape +the inner + + align:start position:0% +the inner + + + align:start position:0% +the inner +sandbox make sense any + + align:start position:0% +sandbox make sense any + + + align:start position:0% +sandbox make sense any +questions so the validator in Native + + align:start position:0% +questions so the validator in Native + + + align:start position:0% +questions so the validator in Native +client has to be really in sync with + + align:start position:0% +client has to be really in sync with + + + align:start position:0% +client has to be really in sync with +what the CPU is doing because it's sort + + align:start position:0% +what the CPU is doing because it's sort + + + align:start position:0% +what the CPU is doing because it's sort +of guessing well here's exactly how the + + align:start position:0% +of guessing well here's exactly how the + + + align:start position:0% +of guessing well here's exactly how the +CPU is going to interpret every + + align:start position:0% +CPU is going to interpret every + + + align:start position:0% +CPU is going to interpret every +instruction it has to be right at every + + align:start position:0% +instruction it has to be right at every + + + align:start position:0% +instruction it has to be right at every +level here um so that's going to be a + + align:start position:0% +level here um so that's going to be a + + + align:start position:0% +level here um so that's going to be a +little bit tricky to do right um there's + + align:start position:0% +little bit tricky to do right um there's + + + align:start position:0% +little bit tricky to do right um there's +been actually sort of other interesting + + align:start position:0% +been actually sort of other interesting + + + align:start position:0% +been actually sort of other interesting +bugs in Native client that people have + + align:start position:0% +bugs in Native client that people have + + + align:start position:0% +bugs in Native client that people have +found one I think has to do with not + + align:start position:0% +found one I think has to do with not + + + align:start position:0% +found one I think has to do with not +properly sanitizing the environment of + + align:start position:0% +properly sanitizing the environment of + + + align:start position:0% +properly sanitizing the environment of +the CPU when you're jumping into the + + align:start position:0% +the CPU when you're jumping into the + + + align:start position:0% +the CPU when you're jumping into the +trusted service runtime so I guess we'll + + align:start position:0% +trusted service runtime so I guess we'll + + + align:start position:0% +trusted service runtime so I guess we'll +talk about this in a second but the + + align:start position:0% +talk about this in a second but the + + + align:start position:0% +talk about this in a second but the +trusted service runtime is going to + + align:start position:0% +trusted service runtime is going to + + + align:start position:0% +trusted service runtime is going to +basically run with the same sort of set + + align:start position:0% +basically run with the same sort of set + + + align:start position:0% +basically run with the same sort of set +of CPU registers initially that the + + align:start position:0% +of CPU registers initially that the + + + align:start position:0% +of CPU registers initially that the +untrusted module was running with so if + + align:start position:0% +untrusted module was running with so if + + + align:start position:0% +untrusted module was running with so if +there's something that it forgets to + + align:start position:0% +there's something that it forgets to + + + align:start position:0% +there's something that it forgets to +clear or reset or whatnot then the + + align:start position:0% +clear or reset or whatnot then the + + + align:start position:0% +clear or reset or whatnot then the +trusted service runtime might be tricked + + align:start position:0% +trusted service runtime might be tricked + + + align:start position:0% +trusted service runtime might be tricked +into doing something uh that wasn't + + align:start position:0% +into doing something uh that wasn't + + + align:start position:0% +into doing something uh that wasn't +meant to do or the developers didn't + + align:start position:0% +meant to do or the developers didn't + + + align:start position:0% +meant to do or the developers didn't +want to do it + + align:start position:0% +want to do it + + + align:start position:0% +want to do it +initially okay so let's see where are we + + align:start position:0% +initially okay so let's see where are we + + + align:start position:0% +initially okay so let's see where are we +now so what we understand now is roughly + + align:start position:0% +now so what we understand now is roughly + + + align:start position:0% +now so what we understand now is roughly +how we can disassemble all the + + align:start position:0% +how we can disassemble all the + + + align:start position:0% +how we can disassemble all the +instructions and how to prevent + + align:start position:0% +instructions and how to prevent + + + align:start position:0% +instructions and how to prevent +disallowed instructions so now let's + + align:start position:0% +disallowed instructions so now let's + + + align:start position:0% +disallowed instructions so now let's +look at how do we keep the memory + + align:start position:0% +look at how do we keep the memory + + + align:start position:0% +look at how do we keep the memory +references for both code and data within + + align:start position:0% +references for both code and data within + + + align:start position:0% +references for both code and data within +the bounds of the + + align:start position:0% +the bounds of the + + + align:start position:0% +the bounds of the +module so for performance reasons the + + align:start position:0% +module so for performance reasons the + + + align:start position:0% +module so for performance reasons the +native client guys actually start using + + align:start position:0% +native client guys actually start using + + + align:start position:0% +native client guys actually start using +some Hardware support at this point to + + align:start position:0% +some Hardware support at this point to + + + align:start position:0% +some Hardware support at this point to +make sure this actually doesn't impose + + align:start position:0% +make sure this actually doesn't impose + + + align:start position:0% +make sure this actually doesn't impose +much overhead but before we look at the + + align:start position:0% +much overhead but before we look at the + + + align:start position:0% +much overhead but before we look at the +hardware support that they use does + + align:start position:0% +hardware support that they use does + + + align:start position:0% +hardware support that they use does +anyone have any suggestions for how we + + align:start position:0% +anyone have any suggestions for how we + + + align:start position:0% +anyone have any suggestions for how we +could do it actually without any + + align:start position:0% +could do it actually without any + + + align:start position:0% +could do it actually without any +hardware support could we just enforce + + align:start position:0% +hardware support could we just enforce + + + align:start position:0% +hardware support could we just enforce +all the memory accesses going in bounds + + align:start position:0% +all the memory accesses going in bounds + + + align:start position:0% +all the memory accesses going in bounds +with the Machinery we have so + + align:start position:0% +with the Machinery we have so + + + align:start position:0% +with the Machinery we have so +far yeah we can instrument the + + align:start position:0% +far yeah we can instrument the + + + align:start position:0% +far yeah we can instrument the +instruction is to clear all the higher + + align:start position:0% +instruction is to clear all the higher + + + align:start position:0% +instruction is to clear all the higher +that's right yeah so actually we see we + + align:start position:0% +that's right yeah so actually we see we + + + align:start position:0% +that's right yeah so actually we see we +have this instruction over here which at + + align:start position:0% +have this instruction over here which at + + + align:start position:0% +have this instruction over here which at +every time we s for example jump + + align:start position:0% +every time we s for example jump + + + align:start position:0% +every time we s for example jump +somewhere right now we clear the low + + align:start position:0% +somewhere right now we clear the low + + + align:start position:0% +somewhere right now we clear the low +bits but if you want to keep all the + + align:start position:0% +bits but if you want to keep all the + + + align:start position:0% +bits but if you want to keep all the +possible code that you're executing + + align:start position:0% +possible code that you're executing + + + align:start position:0% +possible code that you're executing +within the low 256 Megs then we could + + align:start position:0% +within the low 256 Megs then we could + + + align:start position:0% +within the low 256 Megs then we could +just replace this with a zero so we end + + align:start position:0% +just replace this with a zero so we end + + + align:start position:0% +just replace this with a zero so we end +with zero FFF Fe zero so this makes + + align:start position:0% +with zero FFF Fe zero so this makes + + + align:start position:0% +with zero FFF Fe zero so this makes +clear as the low bits and also caps the + + align:start position:0% +clear as the low bits and also caps the + + + align:start position:0% +clear as the low bits and also caps the +address to at most 256 Megs so this does + + align:start position:0% +address to at most 256 Megs so this does + + + align:start position:0% +address to at most 256 Megs so this does +exactly what you're sort of suggesting + + align:start position:0% +exactly what you're sort of suggesting + + + align:start position:0% +exactly what you're sort of suggesting +and would make sure that whenever you're + + align:start position:0% +and would make sure that whenever you're + + + align:start position:0% +and would make sure that whenever you're +jumping you're staying within the low + + align:start position:0% +jumping you're staying within the low + + + align:start position:0% +jumping you're staying within the low +256 Megs and the fact that uh I guess + + align:start position:0% +256 Megs and the fact that uh I guess + + + align:start position:0% +256 Megs and the fact that uh I guess +you're we're doing disassembly you can + + align:start position:0% +you're we're doing disassembly you can + + + align:start position:0% +you're we're doing disassembly you can +also check for all the direct jumps that + + align:start position:0% +also check for all the direct jumps that + + + align:start position:0% +also check for all the direct jumps that +they're all in + + align:start position:0% +they're all in + + + align:start position:0% +they're all in +bounds and that's actually not so bad + + align:start position:0% +bounds and that's actually not so bad + + + align:start position:0% +bounds and that's actually not so bad +right the reason I think they don't do + + align:start position:0% +right the reason I think they don't do + + + align:start position:0% +right the reason I think they don't do +this for code is because in x86 you can + + align:start position:0% +this for code is because in x86 you can + + + align:start position:0% +this for code is because in x86 you can +very efficiently encode an and where all + + align:start position:0% +very efficiently encode an and where all + + + align:start position:0% +very efficiently encode an and where all +the top bits are one so this turns out + + align:start position:0% +the top bits are one so this turns out + + + align:start position:0% +the top bits are one so this turns out +to be I think uh basically a three bite + + align:start position:0% +to be I think uh basically a three bite + + + align:start position:0% +to be I think uh basically a three bite +instruction for the end and a two bite + + align:start position:0% +instruction for the end and a two bite + + + align:start position:0% +instruction for the end and a two bite +instruction for the jump so the overhead + + align:start position:0% +instruction for the jump so the overhead + + + align:start position:0% +instruction for the jump so the overhead +is like three more bytes but if you want + + align:start position:0% +is like three more bytes but if you want + + + align:start position:0% +is like three more bytes but if you want +to have non one Pi bits then this is + + align:start position:0% +to have non one Pi bits then this is + + + align:start position:0% +to have non one Pi bits then this is +actually now a five byte instruction all + + align:start position:0% +actually now a five byte instruction all + + + align:start position:0% +actually now a five byte instruction all +of a sudden so I think they're worried a + + align:start position:0% +of a sudden so I think they're worried a + + + align:start position:0% +of a sudden so I think they're worried a +little bit about the overhead here + + align:start position:0% +little bit about the overhead here + + + align:start position:0% +little bit about the overhead here +question there also the problem that you + + align:start position:0% +question there also the problem that you + + + align:start position:0% +question there also the problem that you +might as some instructions which like + + align:start position:0% +might as some instructions which like + + + align:start position:0% +might as some instructions which like +increment the like location that you're + + align:start position:0% +increment the like location that you're + + + align:start position:0% +increment the like location that you're +trying to get so you might say like your + + align:start position:0% +trying to get so you might say like your + + + align:start position:0% +trying to get so you might say like your +instruction might have like a constant + + align:start position:0% +instruction might have like a constant + + + align:start position:0% +instruction might have like a constant +offset or something like that well so I + + align:start position:0% +offset or something like that well so I + + + align:start position:0% +offset or something like that well so I +think yeah you would probably prohibit + + align:start position:0% +think yeah you would probably prohibit + + + align:start position:0% +think yeah you would probably prohibit +instructions that jump to some + + align:start position:0% +instructions that jump to some + + + align:start position:0% +instructions that jump to some +complicated formula of an address so you + + align:start position:0% +complicated formula of an address so you + + + align:start position:0% +complicated formula of an address so you +only support an instruction that jumps + + align:start position:0% +only support an instruction that jumps + + + align:start position:0% +only support an instruction that jumps +directly to this value and this value + + align:start position:0% +directly to this value and this value + + + align:start position:0% +directly to this value and this value +always gets anded and more for memory + + align:start position:0% +always gets anded and more for memory + + + align:start position:0% +always gets anded and more for memory +accesses rather yeah okay so yeah so + + align:start position:0% +accesses rather yeah okay so yeah so + + + align:start position:0% +accesses rather yeah okay so yeah so +that's a good point because this is just + + align:start position:0% +that's a good point because this is just + + + align:start position:0% +that's a good point because this is just +code and for memory access there's lots + + align:start position:0% +code and for memory access there's lots + + + align:start position:0% +code and for memory access there's lots +of weird ways on x86 to refer to a + + align:start position:0% +of weird ways on x86 to refer to a + + + align:start position:0% +of weird ways on x86 to refer to a +particular memory location and in that + + align:start position:0% +particular memory location and in that + + + align:start position:0% +particular memory location and in that +case you'd basically have to first + + align:start position:0% +case you'd basically have to first + + + align:start position:0% +case you'd basically have to first +compute the memory location then insert + + align:start position:0% +compute the memory location then insert + + + align:start position:0% +compute the memory location then insert +an extra end and then do the access and + + align:start position:0% +an extra end and then do the access and + + + align:start position:0% +an extra end and then do the access and +I think that's the real reason why + + align:start position:0% +I think that's the real reason why + + + align:start position:0% +I think that's the real reason why +they're actually very worried about the + + align:start position:0% +they're actually very worried about the + + + align:start position:0% +they're actually very worried about the +performance overheads of this + + align:start position:0% +performance overheads of this + + + align:start position:0% +performance overheads of this +instrumentation uh so on x86 at least on + + align:start position:0% +instrumentation uh so on x86 at least on + + + align:start position:0% +instrumentation uh so on x86 at least on +30 two bit which is what this paper + + align:start position:0% +30 two bit which is what this paper + + + align:start position:0% +30 two bit which is what this paper +talks about they actually use some + + align:start position:0% +talks about they actually use some + + + align:start position:0% +talks about they actually use some +Hardware support instead to limit the + + align:start position:0% +Hardware support instead to limit the + + + align:start position:0% +Hardware support instead to limit the +code and data addresses that the + + align:start position:0% +code and data addresses that the + + + align:start position:0% +code and data addresses that the +untrusted module can refer + + align:start position:0% +untrusted module can refer + + + align:start position:0% +untrusted module can refer +to so this actually leverages some + + align:start position:0% +to so this actually leverages some + + + align:start position:0% +to so this actually leverages some +somewhat esoteric Hardware in x86 so + + align:start position:0% +somewhat esoteric Hardware in x86 so + + + align:start position:0% +somewhat esoteric Hardware in x86 so +let's see what it looks like first + + align:start position:0% +let's see what it looks like first + + + align:start position:0% +let's see what it looks like first +before we start figuring out how we're + + align:start position:0% +before we start figuring out how we're + + + align:start position:0% +before we start figuring out how we're +going to use it to sandbox the Naco + + align:start position:0% +going to use it to sandbox the Naco + + + align:start position:0% +going to use it to sandbox the Naco +module so this Hardware is called + + align:start position:0% +module so this Hardware is called + + + align:start position:0% +module so this Hardware is called +segmentation and sort of left over from + + align:start position:0% +segmentation and sort of left over from + + + align:start position:0% +segmentation and sort of left over from +from the days before x86 actually even + + align:start position:0% +from the days before x86 actually even + + + align:start position:0% +from the days before x86 actually even +had paging so the way it works is + + align:start position:0% +had paging so the way it works is + + + align:start position:0% +had paging so the way it works is +actually um there's + + align:start position:0% +actually um there's + + + align:start position:0% +actually um there's +a + + align:start position:0% +a + + + align:start position:0% +a +segmentation on x86 the way it works is + + align:start position:0% +segmentation on x86 the way it works is + + + align:start position:0% +segmentation on x86 the way it works is +that whenever a process is + + align:start position:0% +that whenever a process is + + + align:start position:0% +that whenever a process is +running um there's + + align:start position:0% +running um there's + + + align:start position:0% +running um there's +actually a table maintained by the + + align:start position:0% +actually a table maintained by the + + + align:start position:0% +actually a table maintained by the +hardware uh that's called a segment + + align:start position:0% +hardware uh that's called a segment + + + align:start position:0% +hardware uh that's called a segment +descriptor table + + align:start position:0% + + + + align:start position:0% + +and what this table has is just a bunch + + align:start position:0% +and what this table has is just a bunch + + + align:start position:0% +and what this table has is just a bunch +of segments numbered from zero up to + + align:start position:0% +of segments numbered from zero up to + + + align:start position:0% +of segments numbered from zero up to +whatever the size of the table is kind + + align:start position:0% +whatever the size of the table is kind + + + align:start position:0% +whatever the size of the table is kind +of like file descriptors in Unix except + + align:start position:0% +of like file descriptors in Unix except + + + align:start position:0% +of like file descriptors in Unix except +every entry has two values in it some + + align:start position:0% +every entry has two values in it some + + + align:start position:0% +every entry has two values in it some +sort of a + + align:start position:0% +sort of a + + + align:start position:0% +sort of a +base and a length and same for every + + align:start position:0% +base and a length and same for every + + + align:start position:0% +base and a length and same for every +entry base and + + align:start position:0% + + + + align:start position:0% + +length Okay so what this table does is + + align:start position:0% +length Okay so what this table does is + + + align:start position:0% +length Okay so what this table does is +tells us uh that we have you know a + + align:start position:0% +tells us uh that we have you know a + + + align:start position:0% +tells us uh that we have you know a +couple of segments and whenever we refer + + align:start position:0% +couple of segments and whenever we refer + + + align:start position:0% +couple of segments and whenever we refer +to a particular segment uh what this in + + align:start position:0% +to a particular segment uh what this in + + + align:start position:0% +to a particular segment uh what this in +some sense means is that we're talking + + align:start position:0% +some sense means is that we're talking + + + align:start position:0% +some sense means is that we're talking +about a chunk of memory that starts at + + align:start position:0% +about a chunk of memory that starts at + + + align:start position:0% +about a chunk of memory that starts at +address base and goes for this length + + align:start position:0% +address base and goes for this length + + + align:start position:0% +address base and goes for this length +from that base + + align:start position:0% +from that base + + + align:start position:0% +from that base +upwards and the way that this actually + + align:start position:0% +upwards and the way that this actually + + + align:start position:0% +upwards and the way that this actually +helps us to enforce memory bounds is + + align:start position:0% +helps us to enforce memory bounds is + + + align:start position:0% +helps us to enforce memory bounds is +that on x86 every single instruction in + + align:start position:0% +that on x86 every single instruction in + + + align:start position:0% +that on x86 every single instruction in +one way or another um whenever it's + + align:start position:0% +one way or another um whenever it's + + + align:start position:0% +one way or another um whenever it's +talking about memory actually talks + + align:start position:0% +talking about memory actually talks + + + align:start position:0% +talking about memory actually talks +talks about memory with respect to a + + align:start position:0% +talks about memory with respect to a + + + align:start position:0% +talks about memory with respect to a +particular particular segment in this + + align:start position:0% +particular particular segment in this + + + align:start position:0% +particular particular segment in this +table so for example when you actually + + align:start position:0% +table so for example when you actually + + + align:start position:0% +table so for example when you actually +do something like move a a memory value + + align:start position:0% +do something like move a a memory value + + + align:start position:0% +do something like move a a memory value +from the value from a pointer stored in + + align:start position:0% +from the value from a pointer stored in + + + align:start position:0% +from the value from a pointer stored in +the eex register into maybe another + + align:start position:0% +the eex register into maybe another + + + align:start position:0% +the eex register into maybe another +pointer stored in the ebx register what + + align:start position:0% +pointer stored in the ebx register what + + + align:start position:0% +pointer stored in the ebx register what +you would sort of think it does is it + + align:start position:0% +you would sort of think it does is it + + + align:start position:0% +you would sort of think it does is it +figures out well what's this address + + align:start position:0% +figures out well what's this address + + + align:start position:0% +figures out well what's this address +loads memory at this address and then + + align:start position:0% +loads memory at this address and then + + + align:start position:0% +loads memory at this address and then +figures out okay what's this address and + + align:start position:0% +figures out okay what's this address and + + + align:start position:0% +figures out okay what's this address and +stores the value there but in fact on + + align:start position:0% +stores the value there but in fact on + + + align:start position:0% +stores the value there but in fact on +x86 there's whenever you're talking + + align:start position:0% +x86 there's whenever you're talking + + + align:start position:0% +x86 there's whenever you're talking +about memory there's an implicit what's + + align:start position:0% +about memory there's an implicit what's + + + align:start position:0% +about memory there's an implicit what's +called a segment descriptor which is + + align:start position:0% +called a segment descriptor which is + + + align:start position:0% +called a segment descriptor which is +kind of like a file descriptor in Unix + + align:start position:0% +kind of like a file descriptor in Unix + + + align:start position:0% +kind of like a file descriptor in Unix +it's just an index into this descriptor + + align:start position:0% +it's just an index into this descriptor + + + align:start position:0% +it's just an index into this descriptor +table and unless sort of specified + + align:start position:0% +table and unless sort of specified + + + align:start position:0% +table and unless sort of specified +otherwise every op code has a default + + align:start position:0% +otherwise every op code has a default + + + align:start position:0% +otherwise every op code has a default +segment in it so in when you're doing a + + align:start position:0% +segment in it so in when you're doing a + + + align:start position:0% +segment in it so in when you're doing a +move this is actually relative to the DS + + align:start position:0% +move this is actually relative to the DS + + + align:start position:0% +move this is actually relative to the DS +or the data segment register so it's + + align:start position:0% +or the data segment register so it's + + + align:start position:0% +or the data segment register so it's +like a special register in your CPU + + align:start position:0% +like a special register in your CPU + + + align:start position:0% +like a special register in your CPU +that's a 16bit integer if I remember + + align:start position:0% +that's a 16bit integer if I remember + + + align:start position:0% +that's a 16bit integer if I remember +correctly and that 16bit integer points + + align:start position:0% +correctly and that 16bit integer points + + + align:start position:0% +correctly and that 16bit integer points +into this descriptor table and the same + + align:start position:0% +into this descriptor table and the same + + + align:start position:0% +into this descriptor table and the same +here here this is actually relative to + + align:start position:0% +here here this is actually relative to + + + align:start position:0% +here here this is actually relative to +that DS segment selector actually a + + align:start position:0% +that DS segment selector actually a + + + align:start position:0% +that DS segment selector actually a +bunch of these guys there are six + + align:start position:0% +bunch of these guys there are six + + + align:start position:0% +bunch of these guys there are six +segment selectors on x86 there's the + + align:start position:0% +segment selectors on x86 there's the + + + align:start position:0% +segment selectors on x86 there's the +code selector CS DS es FS GS and SS + + align:start position:0% +code selector CS DS es FS GS and SS + + + align:start position:0% +code selector CS DS es FS GS and SS +and the code selector is sort of + + align:start position:0% +and the code selector is sort of + + + align:start position:0% +and the code selector is sort of +implicitly used to fetch the instruction + + align:start position:0% +implicitly used to fetch the instruction + + + align:start position:0% +implicitly used to fetch the instruction +so if your instruction pointer points + + align:start position:0% +so if your instruction pointer points + + + align:start position:0% +so if your instruction pointer points +somewhere it's actually relative to what + + align:start position:0% +somewhere it's actually relative to what + + + align:start position:0% +somewhere it's actually relative to what +the Cs segment selector says and most + + align:start position:0% +the Cs segment selector says and most + + + align:start position:0% +the Cs segment selector says and most +data references implicitly use either DS + + align:start position:0% +data references implicitly use either DS + + + align:start position:0% +data references implicitly use either DS +or ES and then fs and Gs are like some + + align:start position:0% +or ES and then fs and Gs are like some + + + align:start position:0% +or ES and then fs and Gs are like some +special things and SS is always used for + + align:start position:0% +special things and SS is always used for + + + align:start position:0% +special things and SS is always used for +the stack operations if you push and pop + + align:start position:0% +the stack operations if you push and pop + + + align:start position:0% +the stack operations if you push and pop +they implicitly come off of this segment + + align:start position:0% +they implicitly come off of this segment + + + align:start position:0% +they implicitly come off of this segment +selector it's like a fairly Baroque + + align:start position:0% +selector it's like a fairly Baroque + + + align:start position:0% +selector it's like a fairly Baroque +Machinery but it turns out to be hugely + + align:start position:0% +Machinery but it turns out to be hugely + + + align:start position:0% +Machinery but it turns out to be hugely +useful for this particular use case + + align:start position:0% +useful for this particular use case + + + align:start position:0% +useful for this particular use case +because what happens is if you access + + align:start position:0% +because what happens is if you access + + + align:start position:0% +because what happens is if you access +some address at you know maybe some + + align:start position:0% +some address at you know maybe some + + + align:start position:0% +some address at you know maybe some +selector DS you know callon some offset + + align:start position:0% +selector DS you know callon some offset + + + align:start position:0% +selector DS you know callon some offset +or some address here what the hardware + + align:start position:0% +or some address here what the hardware + + + align:start position:0% +or some address here what the hardware +will actually do is translate it into + + align:start position:0% +will actually do is translate it into + + + align:start position:0% +will actually do is translate it into +well it'll put this address and it'll + + align:start position:0% +well it'll put this address and it'll + + + align:start position:0% +well it'll put this address and it'll +add the table of + + align:start position:0% +add the table of + + + align:start position:0% +add the table of +DS base to this guy and it'll actually + + align:start position:0% +DS base to this guy and it'll actually + + + align:start position:0% +DS base to this guy and it'll actually +take the address + + align:start position:0% +take the address + + + align:start position:0% +take the address +modul the length from the same table so + + align:start position:0% +modul the length from the same table so + + + align:start position:0% +modul the length from the same table so +whenever you're doing a memory access + + align:start position:0% +whenever you're doing a memory access + + + align:start position:0% +whenever you're doing a memory access +it's actually going to add the base of + + align:start position:0% +it's actually going to add the base of + + + align:start position:0% +it's actually going to add the base of +your segment selectors sort of + + align:start position:0% +your segment selectors sort of + + + align:start position:0% +your segment selectors sort of +descriptor table entry and take your + + align:start position:0% +descriptor table entry and take your + + + align:start position:0% +descriptor table entry and take your +address that you're actually specifying + + align:start position:0% +address that you're actually specifying + + + align:start position:0% +address that you're actually specifying +and mod it with the l of the + + align:start position:0% +and mod it with the l of the + + + align:start position:0% +and mod it with the l of the +corresponding segment does this make + + align:start position:0% +corresponding segment does this make + + + align:start position:0% +corresponding segment does this make +sense it's a little Baro but that's what + + align:start position:0% +sense it's a little Baro but that's what + + + align:start position:0% +sense it's a little Baro but that's what +the hardware gives us so why isn't this + + align:start position:0% +the hardware gives us so why isn't this + + + align:start position:0% +the hardware gives us so why isn't this +use for example for like buffer + + align:start position:0% +use for example for like buffer + + + align:start position:0% +use for example for like buffer +protection yeah a good question so could + + align:start position:0% +protection yeah a good question so could + + + align:start position:0% +protection yeah a good question so could +you use this for protecting against + + align:start position:0% +you use this for protecting against + + + align:start position:0% +you use this for protecting against +buffer + + align:start position:0% + + + + align:start position:0% + +overflows so how what's the plan like + + align:start position:0% +overflows so how what's the plan like + + + align:start position:0% +overflows so how what's the plan like +you could basically set up uh a for + + align:start position:0% +you could basically set up uh a for + + + align:start position:0% +you could basically set up uh a for +every buffer that you have you could put + + align:start position:0% +every buffer that you have you could put + + + align:start position:0% +every buffer that you have you could put +the Buffer's base here you could put the + + align:start position:0% +the Buffer's base here you could put the + + + align:start position:0% +the Buffer's base here you could put the +size of the buffer + + align:start position:0% +size of the buffer + + + align:start position:0% +size of the buffer +there you don't need to there before you + + align:start position:0% +there you don't need to there before you + + + align:start position:0% +there you don't need to there before you +want to write to it you wouldn't need it + + align:start position:0% +want to write to it you wouldn't need it + + + align:start position:0% +want to write to it you wouldn't need it +there conly yeah so I think the reason + + align:start position:0% +there conly yeah so I think the reason + + + align:start position:0% +there conly yeah so I think the reason +that this isn't used so much for + + align:start position:0% +that this isn't used so much for + + + align:start position:0% +that this isn't used so much for +protecting against buffer overflows is + + align:start position:0% +protecting against buffer overflows is + + + align:start position:0% +protecting against buffer overflows is +that this table has at most two to the + + align:start position:0% +that this table has at most two to the + + + align:start position:0% +that this table has at most two to the +16 entries because these descriptors are + + align:start position:0% +16 entries because these descriptors are + + + align:start position:0% +16 entries because these descriptors are +actually 16 bits long and in fact a + + align:start position:0% +actually 16 bits long and in fact a + + + align:start position:0% +actually 16 bits long and in fact a +couple of the bits are used for other + + align:start position:0% +couple of the bits are used for other + + + align:start position:0% +couple of the bits are used for other +stuff so in fact I think you can only + + align:start position:0% +stuff so in fact I think you can only + + + align:start position:0% +stuff so in fact I think you can only +stick like two to the 13 entries here so + + align:start position:0% +stick like two to the 13 entries here so + + + align:start position:0% +stick like two to the 13 entries here so +if you have more than two to the 13 + + align:start position:0% +if you have more than two to the 13 + + + align:start position:0% +if you have more than two to the 13 +variable size array things in your code + + align:start position:0% +variable size array things in your code + + + align:start position:0% +variable size array things in your code +then that's probably going to overflow + + align:start position:0% +then that's probably going to overflow + + + align:start position:0% +then that's probably going to overflow +this stable + + align:start position:0% +this stable + + + align:start position:0% +this stable +it actually a little bit weird for the + + align:start position:0% +it actually a little bit weird for the + + + align:start position:0% +it actually a little bit weird for the +compiler to manipulate this table + + align:start position:0% +compiler to manipulate this table + + + align:start position:0% +compiler to manipulate this table +because the way you actually manipulate + + align:start position:0% +because the way you actually manipulate + + + align:start position:0% +because the way you actually manipulate +it is through system calls so you can't + + align:start position:0% +it is through system calls so you can't + + + align:start position:0% +it is through system calls so you can't +actually directly write to this table + + align:start position:0% +actually directly write to this table + + + align:start position:0% +actually directly write to this table +you have to issue a system call to the + + align:start position:0% +you have to issue a system call to the + + + align:start position:0% +you have to issue a system call to the +operating system and the operating + + align:start position:0% +operating system and the operating + + + align:start position:0% +operating system and the operating +system will put this table into the + + align:start position:0% +system will put this table into the + + + align:start position:0% +system will put this table into the +hardware for you so I think most + + align:start position:0% +hardware for you so I think most + + + align:start position:0% +hardware for you so I think most +compilers just don't bother having this + + align:start position:0% +compilers just don't bother having this + + + align:start position:0% +compilers just don't bother having this +complicated story for managing buffers + + align:start position:0% +complicated story for managing buffers + + + align:start position:0% +complicated story for managing buffers +multic actually did this though so like + + align:start position:0% +multic actually did this though so like + + + align:start position:0% +multic actually did this though so like +on multic you actually had two to the 18 + + align:start position:0% +on multic you actually had two to the 18 + + + align:start position:0% +on multic you actually had two to the 18 +distinct segments and two to the 18 + + align:start position:0% +distinct segments and two to the 18 + + + align:start position:0% +distinct segments and two to the 18 +possible offsets within a segment and + + align:start position:0% +possible offsets within a segment and + + + align:start position:0% +possible offsets within a segment and +every sort of possible like shared + + align:start position:0% +every sort of possible like shared + + + align:start position:0% +every sort of possible like shared +Library chunk or chunk of memory was a + + align:start position:0% +Library chunk or chunk of memory was a + + + align:start position:0% +Library chunk or chunk of memory was a +distinct segment and then they would all + + align:start position:0% +distinct segment and then they would all + + + align:start position:0% +distinct segment and then they would all +be range checked not maybe at the + + align:start position:0% +be range checked not maybe at the + + + align:start position:0% +be range checked not maybe at the +variable level but still yeah presumably + + align:start position:0% +variable level but still yeah presumably + + + align:start position:0% +variable level but still yeah presumably +it's also a bit slower if you have to + + align:start position:0% +it's also a bit slower if you have to + + + align:start position:0% +it's also a bit slower if you have to +chop into the kernel all the time to + + align:start position:0% +chop into the kernel all the time to + + + align:start position:0% +chop into the kernel all the time to +that's right yeah so there's also the + + align:start position:0% +that's right yeah so there's also the + + + align:start position:0% +that's right yeah so there's also the +overhead uh I guess to set this up there + + align:start position:0% +overhead uh I guess to set this up there + + + align:start position:0% +overhead uh I guess to set this up there +would be some overhead or if you create + + align:start position:0% +would be some overhead or if you create + + + align:start position:0% +would be some overhead or if you create +a new buffer on the stack all of a + + align:start position:0% +a new buffer on the stack all of a + + + align:start position:0% +a new buffer on the stack all of a +sudden you have to call in to this guy + + align:start position:0% +sudden you have to call in to this guy + + + align:start position:0% +sudden you have to call in to this guy +and uh uh add an extra entry so yeah + + align:start position:0% +and uh uh add an extra entry so yeah + + + align:start position:0% +and uh uh add an extra entry so yeah +it's U it is nice machinery and but it's + + align:start position:0% +it's U it is nice machinery and but it's + + + align:start position:0% +it's U it is nice machinery and but it's +mostly used for coarser grain things + + align:start position:0% +mostly used for coarser grain things + + + align:start position:0% +mostly used for coarser grain things +because of the overheads of changing it + + align:start position:0% +because of the overheads of changing it + + + align:start position:0% +because of the overheads of changing it +a bit make + + align:start position:0% +a bit make + + + align:start position:0% +a bit make +sense all right so how do these guys + + align:start position:0% +sense all right so how do these guys + + + align:start position:0% +sense all right so how do these guys +actually use now the segmentation + + align:start position:0% +actually use now the segmentation + + + align:start position:0% +actually use now the segmentation +Machinery well you can sort of guess + + align:start position:0% +Machinery well you can sort of guess + + + align:start position:0% +Machinery well you can sort of guess +what how it works I guess by default all + + align:start position:0% +what how it works I guess by default all + + + align:start position:0% +what how it works I guess by default all +these segments in x86 have a base of + + align:start position:0% +these segments in x86 have a base of + + + align:start position:0% +these segments in x86 have a base of +zero and a length of 2 to the 32 so you + + align:start position:0% +zero and a length of 2 to the 32 so you + + + align:start position:0% +zero and a length of 2 to the 32 so you +can access the entire range of memory + + align:start position:0% +can access the entire range of memory + + + align:start position:0% +can access the entire range of memory +you could possibly want so for Native + + align:start position:0% +you could possibly want so for Native + + + align:start position:0% +you could possibly want so for Native +client what they do is code in a base of + + align:start position:0% +client what they do is code in a base of + + + align:start position:0% +client what they do is code in a base of +zero and a length of 256 + + align:start position:0% +zero and a length of 256 + + + align:start position:0% +zero and a length of 256 +Megs and then they Point all these six + + align:start position:0% +Megs and then they Point all these six + + + align:start position:0% +Megs and then they Point all these six +segment selector registers to this entry + + align:start position:0% +segment selector registers to this entry + + + align:start position:0% +segment selector registers to this entry +for a 256 Meg region So then whenever + + align:start position:0% +for a 256 Meg region So then whenever + + + align:start position:0% +for a 256 Meg region So then whenever +the hardware does a memory access it's + + align:start position:0% +the hardware does a memory access it's + + + align:start position:0% +the hardware does a memory access it's +going to modit the the offset with 256 + + align:start position:0% +going to modit the the offset with 256 + + + align:start position:0% +going to modit the the offset with 256 +Megs and it'll be restricted to that 256 + + align:start position:0% +Megs and it'll be restricted to that 256 + + + align:start position:0% +Megs and it'll be restricted to that 256 +Meg range of memory that's allowed for + + align:start position:0% +Meg range of memory that's allowed for + + + align:start position:0% +Meg range of memory that's allowed for +the module to read and modify make + + align:start position:0% +the module to read and modify make + + + align:start position:0% +the module to read and modify make +sense all right so I guess we sort of + + align:start position:0% +sense all right so I guess we sort of + + + align:start position:0% +sense all right so I guess we sort of +roughly understand now this Hardware + + align:start position:0% +roughly understand now this Hardware + + + align:start position:0% +roughly understand now this Hardware +support and how this works uh and how + + align:start position:0% +support and how this works uh and how + + + align:start position:0% +support and how this works uh and how +you could potenti do it without segment + + align:start position:0% +you could potenti do it without segment + + + align:start position:0% +you could potenti do it without segment +selectors um so if we just implement + + align:start position:0% +selectors um so if we just implement + + + align:start position:0% +selectors um so if we just implement +this plan um is there anything that + + align:start position:0% +this plan um is there anything that + + + align:start position:0% +this plan um is there anything that +could go wrong like could we escape out + + align:start position:0% +could go wrong like could we escape out + + + align:start position:0% +could go wrong like could we escape out +of this segment + + align:start position:0% +of this segment + + + align:start position:0% +of this segment +selector in the untrusted + + align:start position:0% + + + + align:start position:0% + +module I guess there's one one thing you + + align:start position:0% +module I guess there's one one thing you + + + align:start position:0% +module I guess there's one one thing you +have to watch out for is that these + + align:start position:0% +have to watch out for is that these + + + align:start position:0% +have to watch out for is that these +registers are just like regular + + align:start position:0% +registers are just like regular + + + align:start position:0% +registers are just like regular +registers and you can actually move + + align:start position:0% +registers and you can actually move + + + align:start position:0% +registers and you can actually move +values in and out of them so you have to + + align:start position:0% +values in and out of them so you have to + + + align:start position:0% +values in and out of them so you have to +make sure that the untrusted module now + + align:start position:0% +make sure that the untrusted module now + + + align:start position:0% +make sure that the untrusted module now +doesn't tamper with these registers the + + align:start position:0% +doesn't tamper with these registers the + + + align:start position:0% +doesn't tamper with these registers the +segment selectors because somewhere in + + align:start position:0% +segment selectors because somewhere in + + + align:start position:0% +segment selectors because somewhere in +your descriptor table is also the + + align:start position:0% +your descriptor table is also the + + + align:start position:0% +your descriptor table is also the +original segment descriptor for your + + align:start position:0% +original segment descriptor for your + + + align:start position:0% +original segment descriptor for your +entire process which has a base of zero + + align:start position:0% +entire process which has a base of zero + + + align:start position:0% +entire process which has a base of zero +and a length of two to the 32 so if the + + align:start position:0% +and a length of two to the 32 so if the + + + align:start position:0% +and a length of two to the 32 so if the +untrusted module could somehow change + + align:start position:0% +untrusted module could somehow change + + + align:start position:0% +untrusted module could somehow change +the Cs or DS or ES or any of these guys + + align:start position:0% +the Cs or DS or ES or any of these guys + + + align:start position:0% +the Cs or DS or ES or any of these guys +to point to this original operating + + align:start position:0% +to point to this original operating + + + align:start position:0% +to point to this original operating +system segment that covers your entire + + align:start position:0% +system segment that covers your entire + + + align:start position:0% +system segment that covers your entire +address space then you could then do + + align:start position:0% +address space then you could then do + + + align:start position:0% +address space then you could then do +memory references with respect to this + + align:start position:0% +memory references with respect to this + + + align:start position:0% +memory references with respect to this +segment and get out of this + + align:start position:0% +segment and get out of this + + + align:start position:0% +segment and get out of this +sandbox so as a result native client has + + align:start position:0% +sandbox so as a result native client has + + + align:start position:0% +sandbox so as a result native client has +to add some more instructions to this + + align:start position:0% +to add some more instructions to this + + + align:start position:0% +to add some more instructions to this +prohibited list so I think they + + align:start position:0% +prohibited list so I think they + + + align:start position:0% +prohibited list so I think they +basically prohibit all instructions that + + align:start position:0% +basically prohibit all instructions that + + + align:start position:0% +basically prohibit all instructions that +you know move into a segment selector DS + + align:start position:0% +you know move into a segment selector DS + + + align:start position:0% +you know move into a segment selector DS +es Etc so that once you're in the + + align:start position:0% +es Etc so that once you're in the + + + align:start position:0% +es Etc so that once you're in the +sandbox you cannot change the segment + + align:start position:0% +sandbox you cannot change the segment + + + align:start position:0% +sandbox you cannot change the segment +that you're referencing things with + + align:start position:0% +that you're referencing things with + + + align:start position:0% +that you're referencing things with +respect to make sense yeah the + + align:start position:0% +respect to make sense yeah the + + + align:start position:0% +respect to make sense yeah the +segmentation AR privil yeah so it turns + + align:start position:0% +segmentation AR privil yeah so it turns + + + align:start position:0% +segmentation AR privil yeah so it turns +out that on x86 the instructions to + + align:start position:0% +out that on x86 the instructions to + + + align:start position:0% +out that on x86 the instructions to +change the segment descriptor table are + + align:start position:0% +change the segment descriptor table are + + + align:start position:0% +change the segment descriptor table are +privileged but changing these sort of es + + align:start position:0% +privileged but changing these sort of es + + + align:start position:0% +privileged but changing these sort of es +into the table are completely + + align:start position:0% +into the table are completely + + + align:start position:0% +into the table are completely +unprivileged + + align:start position:0% +unprivileged + + + align:start position:0% +unprivileged +yeah sense other questions yeah can you + + align:start position:0% +yeah sense other questions yeah can you + + + align:start position:0% +yeah sense other questions yeah can you +initialize the table to put all zero + + align:start position:0% +initialize the table to put all zero + + + align:start position:0% +initialize the table to put all zero +lens in the unused slots well yes so the + + align:start position:0% +lens in the unused slots well yes so the + + + align:start position:0% +lens in the unused slots well yes so the +the unused slots uh you could yeah you + + align:start position:0% +the unused slots uh you could yeah you + + + align:start position:0% +the unused slots uh you could yeah you +can set the length of the table to + + align:start position:0% +can set the length of the table to + + + align:start position:0% +can set the length of the table to +something so there are no unused slots + + align:start position:0% +something so there are no unused slots + + + align:start position:0% +something so there are no unused slots +it turns out that you actually need this + + align:start position:0% +it turns out that you actually need this + + + align:start position:0% +it turns out that you actually need this +extra slot containing zero and 2 to the + + align:start position:0% +extra slot containing zero and 2 to the + + + align:start position:0% +extra slot containing zero and 2 to the +32 because the trusted runtime is going + + align:start position:0% +32 because the trusted runtime is going + + + align:start position:0% +32 because the trusted runtime is going +to need to run in this segment and + + align:start position:0% +to need to run in this segment and + + + align:start position:0% +to need to run in this segment and +access the entire memory range so you + + align:start position:0% +access the entire memory range so you + + + align:start position:0% +access the entire memory range so you +need this entry in there for the trusted + + align:start position:0% +need this entry in there for the trusted + + + align:start position:0% +need this entry in there for the trusted +runtime to work question in order to set + + align:start position:0% +runtime to work question in order to set + + + align:start position:0% +runtime to work question in order to set +this in order to set the table + + align:start position:0% + + + + align:start position:0% + +out no actually it's pretty cool there's + + align:start position:0% +out no actually it's pretty cool there's + + + align:start position:0% +out no actually it's pretty cool there's +like something that you don't have to be + + align:start position:0% +like something that you don't have to be + + + align:start position:0% +like something that you don't have to be +root for on Linux there's actually a + + align:start position:0% +root for on Linux there's actually a + + + align:start position:0% +root for on Linux there's actually a +system called I think it's called modify + + align:start position:0% +system called I think it's called modify + + + align:start position:0% +system called I think it's called modify +unor ldt for local descriptor table and + + align:start position:0% +unor ldt for local descriptor table and + + + align:start position:0% +unor ldt for local descriptor table and +it lets any process modify its own table + + align:start position:0% +it lets any process modify its own table + + + align:start position:0% +it lets any process modify its own table +these tables are actually per process + + align:start position:0% +these tables are actually per process + + + align:start position:0% +these tables are actually per process +well as everything in X is actually more + + align:start position:0% +well as everything in X is actually more + + + align:start position:0% +well as everything in X is actually more +complicated there's a global table and + + align:start position:0% +complicated there's a global table and + + + align:start position:0% +complicated there's a global table and +there's a local table table but the + + align:start position:0% +there's a local table table but the + + + align:start position:0% +there's a local table table but the +local table is per process you can + + align:start position:0% +local table is per process you can + + + align:start position:0% +local table is per process you can +modify that one uh at least yeah Mak + + align:start position:0% +modify that one uh at least yeah Mak + + + align:start position:0% +modify that one uh at least yeah Mak +sense all + + align:start position:0% +sense all + + + align:start position:0% +sense all +right okay so I guess one thing we could + + align:start position:0% +right okay so I guess one thing we could + + + align:start position:0% +right okay so I guess one thing we could +uh now try to figure out is how do we + + align:start position:0% +uh now try to figure out is how do we + + + align:start position:0% +uh now try to figure out is how do we +jump in and out of the Native client + + align:start position:0% +jump in and out of the Native client + + + align:start position:0% +jump in and out of the Native client +runtime or or out of the sandbox right + + align:start position:0% +runtime or or out of the sandbox right + + + align:start position:0% +runtime or or out of the sandbox right +so what does it mean for us to jump out + + align:start position:0% +so what does it mean for us to jump out + + + align:start position:0% +so what does it mean for us to jump out +so we need to run that trusted code and + + align:start position:0% +so we need to run that trusted code and + + + align:start position:0% +so we need to run that trusted code and +the trusted code lives somewhere up + + align:start position:0% +the trusted code lives somewhere up + + + align:start position:0% +the trusted code lives somewhere up +above the 256 Meg limit and in order to + + align:start position:0% +above the 256 Meg limit and in order to + + + align:start position:0% +above the 256 Meg limit and in order to +jump there we basically have to undo all + + align:start position:0% +jump there we basically have to undo all + + + align:start position:0% +jump there we basically have to undo all +these protections that native client + + align:start position:0% +these protections that native client + + + align:start position:0% +these protections that native client +sets in place and they basically boil + + align:start position:0% +sets in place and they basically boil + + + align:start position:0% +sets in place and they basically boil +down to changing these uh selectors so + + align:start position:0% +down to changing these uh selectors so + + + align:start position:0% +down to changing these uh selectors so +we already I guess our validator isn't + + align:start position:0% +we already I guess our validator isn't + + + align:start position:0% +we already I guess our validator isn't +going to enforce the same rules for the + + align:start position:0% +going to enforce the same rules for the + + + align:start position:0% +going to enforce the same rules for the +stuff above 256 Meg so that's easy + + align:start position:0% +stuff above 256 Meg so that's easy + + + align:start position:0% +stuff above 256 Meg so that's easy +enough but then we need to somehow jump + + align:start position:0% +enough but then we need to somehow jump + + + align:start position:0% +enough but then we need to somehow jump +into the trusted runtime and reset these + + align:start position:0% +into the trusted runtime and reset these + + + align:start position:0% +into the trusted runtime and reset these +segment selectors to the right values to + + align:start position:0% +segment selectors to the right values to + + + align:start position:0% +segment selectors to the right values to +this sort of giant segment that covers + + align:start position:0% +this sort of giant segment that covers + + + align:start position:0% +this sort of giant segment that covers +the entire process address space so the + + align:start position:0% +the entire process address space so the + + + align:start position:0% +the entire process address space so the +way that works on uh Native client is + + align:start position:0% +way that works on uh Native client is + + + align:start position:0% +way that works on uh Native client is +through this mechanism they call + + align:start position:0% +through this mechanism they call + + + align:start position:0% +through this mechanism they call +trampolines and spring + + align:start position:0% + + + + align:start position:0% + +springboards so all these guys are + + align:start position:0% +springboards so all these guys are + + + align:start position:0% +springboards so all these guys are +things that uh live in the low 64k of + + align:start position:0% +things that uh live in the low 64k of + + + align:start position:0% +things that uh live in the low 64k of +the process of the module um and the + + align:start position:0% +the process of the module um and the + + + align:start position:0% +the process of the module um and the +cool thing about that is that these are + + align:start position:0% +cool thing about that is that these are + + + align:start position:0% +cool thing about that is that these are +going to be sort of chunks of code + + align:start position:0% +going to be sort of chunks of code + + + align:start position:0% +going to be sort of chunks of code +living that low 64k of the process space + + align:start position:0% +living that low 64k of the process space + + + align:start position:0% +living that low 64k of the process space +so that means that this untrusted module + + align:start position:0% +so that means that this untrusted module + + + align:start position:0% +so that means that this untrusted module +can actually jump there because it's a + + align:start position:0% +can actually jump there because it's a + + + align:start position:0% +can actually jump there because it's a +valid code address it's going to be on a + + align:start position:0% +valid code address it's going to be on a + + + align:start position:0% +valid code address it's going to be on a +32 by boundary potentially and it's + + align:start position:0% +32 by boundary potentially and it's + + + align:start position:0% +32 by boundary potentially and it's +going to be within the 256 Meg limit so + + align:start position:0% +going to be within the 256 Meg limit so + + + align:start position:0% +going to be within the 256 Meg limit so +you can jump to these + + align:start position:0% +you can jump to these + + + align:start position:0% +you can jump to these +trampolines but the native client + + align:start position:0% +trampolines but the native client + + + align:start position:0% +trampolines but the native client +runtime is going to actually copy these + + align:start position:0% +runtime is going to actually copy these + + + align:start position:0% +runtime is going to actually copy these +trampolines from somewhere outside so + + align:start position:0% +trampolines from somewhere outside so + + + align:start position:0% +trampolines from somewhere outside so +the native client module isn't allowed + + align:start position:0% +the native client module isn't allowed + + + align:start position:0% +the native client module isn't allowed +to supply its own trampoline code the + + align:start position:0% +to supply its own trampoline code the + + + align:start position:0% +to supply its own trampoline code the +trampoline code comes from The Trusted + + align:start position:0% +trampoline code comes from The Trusted + + + align:start position:0% +trampoline code comes from The Trusted +runtime so as a result it can actually + + align:start position:0% +runtime so as a result it can actually + + + align:start position:0% +runtime so as a result it can actually +contain some of these sensitive + + align:start position:0% +contain some of these sensitive + + + align:start position:0% +contain some of these sensitive +instructions like moving DS and CS + + align:start position:0% +instructions like moving DS and CS + + + align:start position:0% +instructions like moving DS and CS +Etc that the untrusted code itself is + + align:start position:0% +Etc that the untrusted code itself is + + + align:start position:0% +Etc that the untrusted code itself is +not allowed to have + + align:start position:0% +not allowed to have + + + align:start position:0% +not allowed to have +so the way you actually jump out of the + + align:start position:0% +so the way you actually jump out of the + + + align:start position:0% +so the way you actually jump out of the +sandbox and into the trusted run time to + + align:start position:0% +sandbox and into the trusted run time to + + + align:start position:0% +sandbox and into the trusted run time to +do something like malok or create a + + align:start position:0% +do something like malok or create a + + + align:start position:0% +do something like malok or create a +thread is you jump to a trampoline which + + align:start position:0% +thread is you jump to a trampoline which + + + align:start position:0% +thread is you jump to a trampoline which +uh lives at a 32 by offset so maybe it's + + align:start position:0% +uh lives at a 32 by offset so maybe it's + + + align:start position:0% +uh lives at a 32 by offset so maybe it's +an address well who knows maybe it's + + align:start position:0% +an address well who knows maybe it's + + + align:start position:0% +an address well who knows maybe it's +4096 plus 32 and it's going to have some + + align:start position:0% +4096 plus 32 and it's going to have some + + + align:start position:0% +4096 plus 32 and it's going to have some +instructions to basically undo these + + align:start position:0% +instructions to basically undo these + + + align:start position:0% +instructions to basically undo these +segment selector so what it's probably + + align:start position:0% +segment selector so what it's probably + + + align:start position:0% +segment selector so what it's probably +going to do is it's going to you know + + align:start position:0% +going to do is it's going to you know + + + align:start position:0% +going to do is it's going to you know +move some value I don't know maybe seven + + align:start position:0% +move some value I don't know maybe seven + + + align:start position:0% +move some value I don't know maybe seven +into the DS register and maybe 7 point + + align:start position:0% +into the DS register and maybe 7 point + + + align:start position:0% +into the DS register and maybe 7 point +to this entry here that's allowed for + + align:start position:0% +to this entry here that's allowed for + + + align:start position:0% +to this entry here that's allowed for +the entire 2 to 32 address space and + + align:start position:0% +the entire 2 to 32 address space and + + + align:start position:0% +the entire 2 to 32 address space and +then you're going to effectively move Cs + + align:start position:0% +then you're going to effectively move Cs + + + align:start position:0% +then you're going to effectively move Cs +and then jump somewhere up into the + + align:start position:0% +and then jump somewhere up into the + + + align:start position:0% +and then jump somewhere up into the +service + + align:start position:0% +service + + + align:start position:0% +service +runtime and this is basically going to + + align:start position:0% +runtime and this is basically going to + + + align:start position:0% +runtime and this is basically going to +be past 256 + + align:start position:0% +be past 256 + + + align:start position:0% +be past 256 +Megs so there's going to be this jump in + + align:start position:0% +Megs so there's going to be this jump in + + + align:start position:0% +Megs so there's going to be this jump in +here that's not regularly allowed but + + align:start position:0% +here that's not regularly allowed but + + + align:start position:0% +here that's not regularly allowed but +we're going to be okay with it because + + align:start position:0% +we're going to be okay with it because + + + align:start position:0% +we're going to be okay with it because +it's going to be into a point in The + + align:start position:0% +it's going to be into a point in The + + + align:start position:0% +it's going to be into a point in The +Trusted service runtime that is + + align:start position:0% +Trusted service runtime that is + + + align:start position:0% +Trusted service runtime that is +expecting these jumps and it's going to + + align:start position:0% +expecting these jumps and it's going to + + + align:start position:0% +expecting these jumps and it's going to +perform proper checks afterwards uh on + + align:start position:0% +perform proper checks afterwards uh on + + + align:start position:0% +perform proper checks afterwards uh on +the jump on the arguments and whatever + + align:start position:0% +the jump on the arguments and whatever + + + align:start position:0% +the jump on the arguments and whatever +else that is being passed around and we + + align:start position:0% +else that is being passed around and we + + + align:start position:0% +else that is being passed around and we +can actually do this move DS here + + align:start position:0% +can actually do this move DS here + + + align:start position:0% +can actually do this move DS here +because we know that it's actually safe + + align:start position:0% +because we know that it's actually safe + + + align:start position:0% +because we know that it's actually safe +the code we're going to jump to isn't + + align:start position:0% +the code we're going to jump to isn't + + + align:start position:0% +the code we're going to jump to isn't +going to do anything arbitrary or funny + + align:start position:0% +going to do anything arbitrary or funny + + + align:start position:0% +going to do anything arbitrary or funny +with our untrusted module make sense + + align:start position:0% +with our untrusted module make sense + + + align:start position:0% +with our untrusted module make sense +roughly what's going + + align:start position:0% +roughly what's going + + + align:start position:0% +roughly what's going +on so why do these guys bother jumping + + align:start position:0% +on so why do these guys bother jumping + + + align:start position:0% +on so why do these guys bother jumping +out of this segments like why not just + + align:start position:0% +out of this segments like why not just + + + align:start position:0% +out of this segments like why not just +put the whole thing in in the trampoline + + align:start position:0% + + + + align:start position:0% + +seems like more work in some level yeah + + align:start position:0% +seems like more work in some level yeah + + + align:start position:0% +seems like more work in some level yeah +only have4 yeah you don't actually have + + align:start position:0% +only have4 yeah you don't actually have + + + align:start position:0% +only have4 yeah you don't actually have +a lot of space and well I guess you have + + align:start position:0% +a lot of space and well I guess you have + + + align:start position:0% +a lot of space and well I guess you have +64k so that's potentially maybe enough + + align:start position:0% +64k so that's potentially maybe enough + + + align:start position:0% +64k so that's potentially maybe enough +for like maybe you can Implement maloc + + align:start position:0% +for like maybe you can Implement maloc + + + align:start position:0% +for like maybe you can Implement maloc +in there but the problem is not so much + + align:start position:0% +in there but the problem is not so much + + + align:start position:0% +in there but the problem is not so much +the 64k I think but this 32 by + + align:start position:0% +the 64k I think but this 32 by + + + align:start position:0% +the 64k I think but this 32 by +restriction and it's actually not a + + align:start position:0% +restriction and it's actually not a + + + align:start position:0% +restriction and it's actually not a +restriction on The Trusted code because + + align:start position:0% +restriction on The Trusted code because + + + align:start position:0% +restriction on The Trusted code because +the trusted code can do whatever it + + align:start position:0% +the trusted code can do whatever it + + + align:start position:0% +the trusted code can do whatever it +wants here it's not going to be checked + + align:start position:0% +wants here it's not going to be checked + + + align:start position:0% +wants here it's not going to be checked +the problem is that the untrusted code + + align:start position:0% +the problem is that the untrusted code + + + align:start position:0% +the problem is that the untrusted code +can jump to every 32 byte offset so + + align:start position:0% +can jump to every 32 byte offset so + + + align:start position:0% +can jump to every 32 byte offset so +every 32 white offset has to be prepared + + align:start position:0% +every 32 white offset has to be prepared + + + align:start position:0% +every 32 white offset has to be prepared +to be very suspicious of its arguments + + align:start position:0% +to be very suspicious of its arguments + + + align:start position:0% +to be very suspicious of its arguments +so you probably are going to be are + + align:start position:0% +so you probably are going to be are + + + align:start position:0% +so you probably are going to be are +going to have a hard time writing this + + align:start position:0% +going to have a hard time writing this + + + align:start position:0% +going to have a hard time writing this +code here with every 32 by rechecking + + align:start position:0% +code here with every 32 by rechecking + + + align:start position:0% +code here with every 32 by rechecking +the arguments and values and so on so + + align:start position:0% +the arguments and values and so on so + + + align:start position:0% +the arguments and values and so on so +basically you have to jump out of the + + align:start position:0% +basically you have to jump out of the + + + align:start position:0% +basically you have to jump out of the +trampoline and into the runtime up here + + align:start position:0% +trampoline and into the runtime up here + + + align:start position:0% +trampoline and into the runtime up here +within 32 bytes of + + align:start position:0% +within 32 bytes of + + + align:start position:0% +within 32 bytes of +code so then if you jump to the next + + align:start position:0% +code so then if you jump to the next + + + align:start position:0% +code so then if you jump to the next +thing then well something else is going + + align:start position:0% +thing then well something else is going + + + align:start position:0% +thing then well something else is going +to happen here but it's not part of this + + align:start position:0% +to happen here but it's not part of this + + + align:start position:0% +to happen here but it's not part of this +same trusted routine + + align:start position:0% +same trusted routine + + + align:start position:0% +same trusted routine +here + + align:start position:0% +here + + + align:start position:0% +here +sense okay so this is how you sort of + + align:start position:0% +sense okay so this is how you sort of + + + align:start position:0% +sense okay so this is how you sort of +jump out of the uh sandbox to jump back + + align:start position:0% +jump out of the uh sandbox to jump back + + + align:start position:0% +jump out of the uh sandbox to jump back +in you also need to you basically need + + align:start position:0% +in you also need to you basically need + + + align:start position:0% +in you also need to you basically need +to invert the these Transformations you + + align:start position:0% +to invert the these Transformations you + + + align:start position:0% +to invert the these Transformations you +need to sort of set the DS back and CS + + align:start position:0% +need to sort of set the DS back and CS + + + align:start position:0% +need to sort of set the DS back and CS +back and so on and the tricky thing is + + align:start position:0% +back and so on and the tricky thing is + + + align:start position:0% +back and so on and the tricky thing is +that if you're running outside of this + + align:start position:0% +that if you're running outside of this + + + align:start position:0% +that if you're running outside of this +um 256 Meg limit if you're running + + align:start position:0% +um 256 Meg limit if you're running + + + align:start position:0% +um 256 Meg limit if you're running +inside of the trusted runtime then you + + align:start position:0% +inside of the trusted runtime then you + + + align:start position:0% +inside of the trusted runtime then you +can't really reset these registers yet + + align:start position:0% +can't really reset these registers yet + + + align:start position:0% +can't really reset these registers yet +because otherwise you won't then be able + + align:start position:0% +because otherwise you won't then be able + + + align:start position:0% +because otherwise you won't then be able +to access any of the memory in your sort + + align:start position:0% +to access any of the memory in your sort + + + align:start position:0% +to access any of the memory in your sort +of space outside so what they actually + + align:start position:0% +of space outside so what they actually + + + align:start position:0% +of space outside so what they actually +do is they have this thing called a + + align:start position:0% +do is they have this thing called a + + + align:start position:0% +do is they have this thing called a +springboard which is how the trusted + + align:start position:0% +springboard which is how the trusted + + + align:start position:0% +springboard which is how the trusted +runtime from outside the 256 Meg limit + + align:start position:0% +runtime from outside the 256 Meg limit + + + align:start position:0% +runtime from outside the 256 Meg limit +is actually going to jump back into the + + align:start position:0% +is actually going to jump back into the + + + align:start position:0% +is actually going to jump back into the +native client module so here it's going + + align:start position:0% +native client module so here it's going + + + align:start position:0% +native client module so here it's going +to reload the DS register with maybe + + align:start position:0% +to reload the DS register with maybe + + + align:start position:0% +to reload the DS register with maybe +whatever that limited segment descriptor + + align:start position:0% +whatever that limited segment descriptor + + + align:start position:0% +whatever that limited segment descriptor +is maybe let's say it's one and then + + align:start position:0% +is maybe let's say it's one and then + + + align:start position:0% +is maybe let's say it's one and then +it's going to reset other things and + + align:start position:0% +it's going to reset other things and + + + align:start position:0% +it's going to reset other things and +then it'll jump to you know whatever + + align:start position:0% +then it'll jump to you know whatever + + + align:start position:0% +then it'll jump to you know whatever +address the trust runtime wants to + + align:start position:0% +address the trust runtime wants to + + + align:start position:0% +address the trust runtime wants to +return to in the untrusted module Mak + + align:start position:0% +return to in the untrusted module Mak + + + align:start position:0% +return to in the untrusted module Mak +sense so this is how you sort of jump + + align:start position:0% +sense so this is how you sort of jump + + + align:start position:0% +sense so this is how you sort of jump +back in and the only sort of tricky + + align:start position:0% +back in and the only sort of tricky + + + align:start position:0% +back in and the only sort of tricky +piece here is that you don't want the + + align:start position:0% +piece here is that you don't want the + + + align:start position:0% +piece here is that you don't want the +untrusted code to jump into the + + align:start position:0% +untrusted code to jump into the + + + align:start position:0% +untrusted code to jump into the +springboard itself maybe something weird + + align:start position:0% +springboard itself maybe something weird + + + align:start position:0% +springboard itself maybe something weird +will happen who knows so what they do is + + align:start position:0% +will happen who knows so what they do is + + + align:start position:0% +will happen who knows so what they do is +they actually put a halt instruction as + + align:start position:0% +they actually put a halt instruction as + + + align:start position:0% +they actually put a halt instruction as +the first bite of this 32 by multiple + + align:start position:0% +the first bite of this 32 by multiple + + + align:start position:0% +the first bite of this 32 by multiple +sequence so if you jump into the middle + + align:start position:0% +sequence so if you jump into the middle + + + align:start position:0% +sequence so if you jump into the middle +of to the beginning of this guy you'll + + align:start position:0% +of to the beginning of this guy you'll + + + align:start position:0% +of to the beginning of this guy you'll +immediately halt the trusted runtime is + + align:start position:0% +immediately halt the trusted runtime is + + + align:start position:0% +immediately halt the trusted runtime is +going to jump to one past this bite and + + align:start position:0% +going to jump to one past this bite and + + + align:start position:0% +going to jump to one past this bite and +be able to execute the springboard but + + align:start position:0% +be able to execute the springboard but + + + align:start position:0% +be able to execute the springboard but +this is something that only The Trusted + + align:start position:0% +this is something that only The Trusted + + + align:start position:0% +this is something that only The Trusted +runtime can do because regularly check + + align:start position:0% +runtime can do because regularly check + + + align:start position:0% +runtime can do because regularly check +this is not going to be allowed question + + align:start position:0% +this is not going to be allowed question + + + align:start position:0% +this is not going to be allowed question +is a springboard in the untrusted module + + align:start position:0% +is a springboard in the untrusted module + + + align:start position:0% +is a springboard in the untrusted module +so the springboard is within the 0 to 56 + + align:start position:0% +so the springboard is within the 0 to 56 + + + align:start position:0% +so the springboard is within the 0 to 56 +Meg part of the untrusted module but it + + align:start position:0% +Meg part of the untrusted module but it + + + align:start position:0% +Meg part of the untrusted module but it +actually lives in that 64-bit chunk at + + align:start position:0% +actually lives in that 64-bit chunk at + + + align:start position:0% +actually lives in that 64-bit chunk at +the very beginning that doesn't actually + + align:start position:0% +the very beginning that doesn't actually + + + align:start position:0% +the very beginning that doesn't actually +come from the binary you download from + + align:start position:0% +come from the binary you download from + + + align:start position:0% +come from the binary you download from +some website but it's actually patched + + align:start position:0% +some website but it's actually patched + + + align:start position:0% +some website but it's actually patched +into it by the native client runtime + + align:start position:0% +into it by the native client runtime + + + align:start position:0% +into it by the native client runtime +when it first loads this modu memory why + + align:start position:0% +when it first loads this modu memory why + + + align:start position:0% +when it first loads this modu memory why +not just have it in the runtime yeah so + + align:start position:0% +not just have it in the runtime yeah so + + + align:start position:0% +not just have it in the runtime yeah so +why not have it in the runtime so what + + align:start position:0% +why not have it in the runtime so what + + + align:start position:0% +why not have it in the runtime so what +happens if the runtime was allowed to + + align:start position:0% +happens if the runtime was allowed to + + + align:start position:0% +happens if the runtime was allowed to +supply the + + align:start position:0% + + + + align:start position:0% + +springboard is this + + align:start position:0% + + + + align:start position:0% + +bad + + align:start position:0% +bad + + + align:start position:0% +bad +yeah how how would it know how would it + + align:start position:0% +yeah how how would it know how would it + + + align:start position:0% +yeah how how would it know how would it +know where to jump back to well so + + align:start position:0% +know where to jump back to well so + + + align:start position:0% +know where to jump back to well so +actually I think what this actually is + + align:start position:0% +actually I think what this actually is + + + align:start position:0% +actually I think what this actually is +is it actually jumps to something like + + align:start position:0% +is it actually jumps to something like + + + align:start position:0% +is it actually jumps to something like +eax so the trusted runtime says oh I + + align:start position:0% +eax so the trusted runtime says oh I + + + align:start position:0% +eax so the trusted runtime says oh I +want to return to this address it puts + + align:start position:0% +want to return to this address it puts + + + align:start position:0% +want to return to this address it puts +it in the eax register jumps here the + + align:start position:0% +it in the eax register jumps here the + + + align:start position:0% +it in the eax register jumps here the +springboard does this this this and then + + align:start position:0% +springboard does this this this and then + + + align:start position:0% +springboard does this this this and then +jumps to eax wherever the trusted run + + align:start position:0% +jumps to eax wherever the trusted run + + + align:start position:0% +jumps to eax wherever the trusted run +time set to + + align:start position:0% +time set to + + + align:start position:0% +time set to +jump so what if the module came with its + + align:start position:0% +jump so what if the module came with its + + + align:start position:0% +jump so what if the module came with its +own + + align:start position:0% +own + + + align:start position:0% +own +springboard um well in theory you could + + align:start position:0% +springboard um well in theory you could + + + align:start position:0% +springboard um well in theory you could +do it as like a natural jump type thing + + align:start position:0% +do it as like a natural jump type thing + + + align:start position:0% +do it as like a natural jump type thing +but it shouldn't know anything about the + + align:start position:0% +but it shouldn't know anything about the + + + align:start position:0% +but it shouldn't know anything about the +descriptor table like that's like a + + align:start position:0% +descriptor table like that's like a + + + align:start position:0% +descriptor table like that's like a +hardware yeah so actually this is like a + + align:start position:0% +hardware yeah so actually this is like a + + + align:start position:0% +hardware yeah so actually this is like a +really important instruction for + + align:start position:0% +really important instruction for + + + align:start position:0% +really important instruction for +sandboxing the fact that we reload that + + align:start position:0% +sandboxing the fact that we reload that + + + align:start position:0% +sandboxing the fact that we reload that +descriptor to point at one of those + + align:start position:0% +descriptor to point at one of those + + + align:start position:0% +descriptor to point at one of those +limited descriptors up there it's really + + align:start position:0% +limited descriptors up there it's really + + + align:start position:0% +limited descriptors up there it's really +important and if the module was allowed + + align:start position:0% +important and if the module was allowed + + + align:start position:0% +important and if the module was allowed +to supply its own springboard maybe + + align:start position:0% +to supply its own springboard maybe + + + align:start position:0% +to supply its own springboard maybe +it'll just skip this part and then not + + align:start position:0% +it'll just skip this part and then not + + + align:start position:0% +it'll just skip this part and then not +restrict itself back to 26 Megs so then + + align:start position:0% +restrict itself back to 26 Megs so then + + + align:start position:0% +restrict itself back to 26 Megs so then +once you jump through the springboard + + align:start position:0% +once you jump through the springboard + + + align:start position:0% +once you jump through the springboard +you'll be able to still access the + + align:start position:0% +you'll be able to still access the + + + align:start position:0% +you'll be able to still access the +entire process address space so it's + + align:start position:0% +entire process address space so it's + + + align:start position:0% +entire process address space so it's +actually the springboard is part of the + + align:start position:0% +actually the springboard is part of the + + + align:start position:0% +actually the springboard is part of the +enforcement mechanism it sort of sets up + + align:start position:0% +enforcement mechanism it sort of sets up + + + align:start position:0% +enforcement mechanism it sort of sets up +the boundaries so this is the reason why + + align:start position:0% +the boundaries so this is the reason why + + + align:start position:0% +the boundaries so this is the reason why +I think they don't want the springboard + + align:start position:0% +I think they don't want the springboard + + + align:start position:0% +I think they don't want the springboard +to come from the + + align:start position:0% +to come from the + + + align:start position:0% +to come from the +developer now yeah question put the + + align:start position:0% +developer now yeah question put the + + + align:start position:0% +developer now yeah question put the +spring board p the 256 me so I think uh + + align:start position:0% +spring board p the 256 me so I think uh + + + align:start position:0% +spring board p the 256 me so I think uh +they don't want to put the springboard + + align:start position:0% +they don't want to put the springboard + + + align:start position:0% +they don't want to put the springboard +past the 256 Megs because then you might + + align:start position:0% +past the 256 Megs because then you might + + + align:start position:0% +past the 256 Megs because then you might +have trouble jumping down so you want to + + align:start position:0% +have trouble jumping down so you want to + + + align:start position:0% +have trouble jumping down so you want to +jump to a particular address but you + + align:start position:0% +jump to a particular address but you + + + align:start position:0% +jump to a particular address but you +also want to set some extra registers + + align:start position:0% +also want to set some extra registers + + + align:start position:0% +also want to set some extra registers +here so if + + align:start position:0% +here so if + + + align:start position:0% +here so if +you're I think this basically has to + + align:start position:0% +you're I think this basically has to + + + align:start position:0% +you're I think this basically has to +sorry this has to do with setting that + + align:start position:0% +sorry this has to do with setting that + + + align:start position:0% +sorry this has to do with setting that +CS code descriptor segment because you + + align:start position:0% +CS code descriptor segment because you + + + align:start position:0% +CS code descriptor segment because you +want to set the code descriptor segment + + align:start position:0% +want to set the code descriptor segment + + + align:start position:0% +want to set the code descriptor segment +to this bounded segment and you want to + + align:start position:0% +to this bounded segment and you want to + + + align:start position:0% +to this bounded segment and you want to +jump to some particular address at the + + align:start position:0% +jump to some particular address at the + + + align:start position:0% +jump to some particular address at the +same time so I think it's easier for + + align:start position:0% +same time so I think it's easier for + + + align:start position:0% +same time so I think it's easier for +these guys to do it through a + + align:start position:0% +these guys to do it through a + + + align:start position:0% +these guys to do it through a +springboard because you first sort of + + align:start position:0% +springboard because you first sort of + + + align:start position:0% +springboard because you first sort of +jump to here then you can set your CS + + align:start position:0% +jump to here then you can set your CS + + + align:start position:0% +jump to here then you can set your CS +value but you can still execute the same + + align:start position:0% +value but you can still execute the same + + + align:start position:0% +value but you can still execute the same +code you're still + + align:start position:0% +code you're still + + + align:start position:0% +code you're still +running uh because you're within the 256 + + align:start position:0% +running uh because you're within the 256 + + + align:start position:0% +running uh because you're within the 256 +bound make sense hold bit I think it + + align:start position:0% +bound make sense hold bit I think it + + + align:start position:0% +bound make sense hold bit I think it +basically has to do with what Atomic + + align:start position:0% +basically has to do with what Atomic + + + align:start position:0% +basically has to do with what Atomic +Primitives the hardware provides to you + + align:start position:0% +Primitives the hardware provides to you + + + align:start position:0% +Primitives the hardware provides to you +so you basically you want to set a whole + + align:start position:0% +so you basically you want to set a whole + + + align:start position:0% +so you basically you want to set a whole +bunch of these DS segment selector + + align:start position:0% +bunch of these DS segment selector + + + align:start position:0% +bunch of these DS segment selector +registers and the Cs register and jump + + align:start position:0% +registers and the Cs register and jump + + + align:start position:0% +registers and the Cs register and jump +to somewhere at the same time so it's + + align:start position:0% +to somewhere at the same time so it's + + + align:start position:0% +to somewhere at the same time so it's +sort of this is one way to for them to + + align:start position:0% +sort of this is one way to for them to + + + align:start position:0% +sort of this is one way to for them to +do + + align:start position:0% +do + + + align:start position:0% +do +it sense I think that's maybe not as + + align:start position:0% +it sense I think that's maybe not as + + + align:start position:0% +it sense I think that's maybe not as +fundamental I you probably if you if you + + align:start position:0% +fundamental I you probably if you if you + + + align:start position:0% +fundamental I you probably if you if you +tried hard you could probably come up + + align:start position:0% +tried hard you could probably come up + + + align:start position:0% +tried hard you could probably come up +with some x86 instruction sequence that + + align:start position:0% +with some x86 instruction sequence that + + + align:start position:0% +with some x86 instruction sequence that +could do it from outside the uh bounded + + align:start position:0% +could do it from outside the uh bounded + + + align:start position:0% +could do it from outside the uh bounded +address space of the + + align:start position:0% +address space of the + + + align:start position:0% +address space of the +module make sense all right so I guess + + align:start position:0% +module make sense all right so I guess + + + align:start position:0% +module make sense all right so I guess +that's it for uh Native client uh and I + + align:start position:0% +that's it for uh Native client uh and I + + + align:start position:0% +that's it for uh Native client uh and I +see you guys next week we'll talk about + + align:start position:0% +see you guys next week we'll talk about + + + align:start position:0% +see you guys next week we'll talk about +web security starting then \ No newline at end of file diff --git a/I6ZSrgxiofs.txt b/I6ZSrgxiofs.txt new file mode 100644 index 0000000000000000000000000000000000000000..4066b23ed63e1d1a776511bd4875c8deb939b46c --- /dev/null +++ b/I6ZSrgxiofs.txt @@ -0,0 +1,12027 @@ +align:start position:0% + +All right. Well, we have two more + + align:start position:0% +All right. Well, we have two more + + + align:start position:0% +All right. Well, we have two more +classes and this is uh day two of trying + + align:start position:0% +classes and this is uh day two of trying + + + align:start position:0% +classes and this is uh day two of trying +to grapple with the recent big + + align:start position:0% +to grapple with the recent big + + + align:start position:0% +to grapple with the recent big +breakthrough in projection theory. So, + + align:start position:0% +breakthrough in projection theory. So, + + + align:start position:0% +breakthrough in projection theory. So, +this is sharp projection theorems part + + align:start position:0% +this is sharp projection theorems part + + + align:start position:0% +this is sharp projection theorems part +two. And in part two we're going to talk + + align:start position:0% +two. And in part two we're going to talk + + + align:start position:0% +two. And in part two we're going to talk +about the ad regular case. So let's + + align:start position:0% +about the ad regular case. So let's + + + align:start position:0% +about the ad regular case. So let's +first remember our goal and remember + + align:start position:0% +first remember our goal and remember + + + align:start position:0% +first remember our goal and remember +what is the ad regular case. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So our goal is the first set conjecture + + align:start position:0% +So our goal is the first set conjecture + + + align:start position:0% +So our goal is the first set conjecture +which is a theorem of Orpin and Schmurk + + align:start position:0% +which is a theorem of Orpin and Schmurk + + + align:start position:0% +which is a theorem of Orpin and Schmurk +and Ren and W says if E contained in R2 + + align:start position:0% +and Ren and W says if E contained in R2 + + + align:start position:0% +and Ren and W says if E contained in R2 +is a delta T C set + + align:start position:0% +is a delta T C set + + + align:start position:0% +is a delta T C set +and then for every point in E there are + + align:start position:0% +and then for every point in E there are + + + align:start position:0% +and then for every point in E there are +a bunch of delta tubes going through it. + + align:start position:0% +a bunch of delta tubes going through it. + + + align:start position:0% +a bunch of delta tubes going through it. +So t subx is a set of delta tubes + + align:start position:0% +So t subx is a set of delta tubes + + + align:start position:0% +So t subx is a set of delta tubes +through x + + align:start position:0% +through x + + + align:start position:0% +through x +and the the directions if you like of + + align:start position:0% +and the the directions if you like of + + + align:start position:0% +and the the directions if you like of +this set of delta tubes is a delta s c + + align:start position:0% +this set of delta tubes is a delta s c + + + align:start position:0% +this set of delta tubes is a delta s c +set. + + align:start position:0% + + + + align:start position:0% + +Okay. And parenthetically we can assume + + align:start position:0% +Okay. And parenthetically we can assume + + + align:start position:0% +Okay. And parenthetically we can assume +a couple of things. uh we can assume + + align:start position:0% +a couple of things. uh we can assume + + + align:start position:0% +a couple of things. uh we can assume +that this is uh is uniform + + align:start position:0% +that this is uh is uniform + + + align:start position:0% +that this is uh is uniform +and also that the number of them it's + + align:start position:0% +and also that the number of them it's + + + align:start position:0% +and also that the number of them it's +like delta to the minus s and s should + + align:start position:0% +like delta to the minus s and s should + + + align:start position:0% +like delta to the minus s and s should +be bigger than zero. + + align:start position:0% +be bigger than zero. + + + align:start position:0% +be bigger than zero. +Okay, so we put all of these tubes + + align:start position:0% +Okay, so we put all of these tubes + + + align:start position:0% +Okay, so we put all of these tubes +together to get one big set of tubes + + align:start position:0% + + + + align:start position:0% + +and the question is how many tubes are + + align:start position:0% +and the question is how many tubes are + + + align:start position:0% +and the question is how many tubes are +there? + + align:start position:0% +there? + + + align:start position:0% +there? +Um so then the conclusion is + + align:start position:0% +Um so then the conclusion is + + + align:start position:0% +Um so then the conclusion is +that the number of tubes is at least a + + align:start position:0% +that the number of tubes is at least a + + + align:start position:0% +that the number of tubes is at least a +little fudge factor. + + align:start position:0% + + + + align:start position:0% + +So this whole thing I'll abbreviate like + + align:start position:0% +So this whole thing I'll abbreviate like + + + align:start position:0% +So this whole thing I'll abbreviate like +that and then the minimum of a few + + align:start position:0% +that and then the minimum of a few + + + align:start position:0% +that and then the minimum of a few +options + + align:start position:0% + + + + align:start position:0% + +which we'll call option A, option B and + + align:start position:0% +which we'll call option A, option B and + + + align:start position:0% +which we'll call option A, option B and +option C. + + align:start position:0% + + + + align:start position:0% + +Okay. And these exponents are hard to + + align:start position:0% +Okay. And these exponents are hard to + + + align:start position:0% +Okay. And these exponents are hard to +remember, but I would prefer to remember + + align:start position:0% +remember, but I would prefer to remember + + + align:start position:0% +remember, but I would prefer to remember +for everyone to think of them in terms + + align:start position:0% +for everyone to think of them in terms + + + align:start position:0% +for everyone to think of them in terms +of three different scenarios. + + align:start position:0% +of three different scenarios. + + + align:start position:0% +of three different scenarios. +So option A that corresponds to the I + + align:start position:0% +So option A that corresponds to the I + + + align:start position:0% +So option A that corresponds to the I +call it the stars scenario. Have a bunch + + align:start position:0% +call it the stars scenario. Have a bunch + + + align:start position:0% +call it the stars scenario. Have a bunch +of points and through each you have a + + align:start position:0% +of points and through each you have a + + + align:start position:0% +of points and through each you have a +bunch of tubes and they're just + + align:start position:0% +bunch of tubes and they're just + + + align:start position:0% +bunch of tubes and they're just +unrelated to each other. + + align:start position:0% +unrelated to each other. + + + align:start position:0% +unrelated to each other. +Option B is more intricate. It's the + + align:start position:0% +Option B is more intricate. It's the + + + align:start position:0% +Option B is more intricate. It's the +integer grid scenario. + + align:start position:0% +integer grid scenario. + + + align:start position:0% +integer grid scenario. +Um and option C is a kind of random + + align:start position:0% +Um and option C is a kind of random + + + align:start position:0% +Um and option C is a kind of random +scenario. So E is arbitrary + + align:start position:0% + + + + align:start position:0% + +and T is random. + + align:start position:0% + + + + align:start position:0% + +Okay. Um + + align:start position:0% +Okay. Um + + + align:start position:0% +Okay. Um +now it's it's really a good idea to + + align:start position:0% +now it's it's really a good idea to + + + align:start position:0% +now it's it's really a good idea to +think about this theorem in these three + + align:start position:0% +think about this theorem in these three + + + align:start position:0% +think about this theorem in these three +different scenarios. So it's good to + + align:start position:0% +different scenarios. So it's good to + + + align:start position:0% +different scenarios. So it's good to +separate out the case where each one of + + align:start position:0% +separate out the case where each one of + + + align:start position:0% +separate out the case where each one of +those things is the minimum. Um, so let + + align:start position:0% +those things is the minimum. Um, so let + + + align:start position:0% +those things is the minimum. Um, so let +me do that and recall for you how much + + align:start position:0% +me do that and recall for you how much + + + align:start position:0% +me do that and recall for you how much +we know about each case so far. + + align:start position:0% + + + + align:start position:0% + +Um, and I said something about this last + + align:start position:0% +Um, and I said something about this last + + + align:start position:0% +Um, and I said something about this last +time, but what I said wasn't uh the best + + align:start position:0% +time, but what I said wasn't uh the best + + + align:start position:0% +time, but what I said wasn't uh the best +thing to say. So I wanted to do it again + + align:start position:0% +thing to say. So I wanted to do it again + + + align:start position:0% +thing to say. So I wanted to do it again +and get it right. + + align:start position:0% +and get it right. + + + align:start position:0% +and get it right. +All right. So there's the case where a + + align:start position:0% +All right. So there's the case where a + + + align:start position:0% +All right. So there's the case where a +is the minimum option. And if you do a + + align:start position:0% +is the minimum option. And if you do a + + + align:start position:0% +is the minimum option. And if you do a +little algebra that corresponds to s + + align:start position:0% +little algebra that corresponds to s + + + align:start position:0% +little algebra that corresponds to s +being at least as big as t. + + align:start position:0% +being at least as big as t. + + + align:start position:0% +being at least as big as t. +Um and in this case + + align:start position:0% +Um and in this case + + + align:start position:0% +Um and in this case +so if s is at least as big as t then the + + align:start position:0% +so if s is at least as big as t then the + + + align:start position:0% +so if s is at least as big as t then the +uh the theorem is is true the first so + + align:start position:0% +uh the theorem is is true the first so + + + align:start position:0% +uh the theorem is is true the first so +first is is true + + align:start position:0% + + + + align:start position:0% + +and it follows just by double counting. + + align:start position:0% + + + + align:start position:0% + +So we did it very early in the course + + align:start position:0% +So we did it very early in the course + + + align:start position:0% +So we did it very early in the course +like on the second one. + + align:start position:0% +like on the second one. + + + align:start position:0% +like on the second one. +Okay. Then I'll come back to B which is + + align:start position:0% +Okay. Then I'll come back to B which is + + + align:start position:0% +Okay. Then I'll come back to B which is +the most interesting. C is the minimal. + + align:start position:0% +the most interesting. C is the minimal. + + + align:start position:0% +the most interesting. C is the minimal. +If you do a little algebra it's if S + + align:start position:0% +If you do a little algebra it's if S + + + align:start position:0% +If you do a little algebra it's if S +plus T is at least two. + + align:start position:0% +plus T is at least two. + + + align:start position:0% +plus T is at least two. +Um and in this whole range where S plus + + align:start position:0% +Um and in this whole range where S plus + + + align:start position:0% +Um and in this whole range where S plus +T is at least two the theorem is is also + + align:start position:0% +T is at least two the theorem is is also + + + align:start position:0% +T is at least two the theorem is is also +true true and it's true by the forier + + align:start position:0% +true true and it's true by the forier + + + align:start position:0% +true true and it's true by the forier +method. So it follows from the theorem + + align:start position:0% +method. So it follows from the theorem + + + align:start position:0% +method. So it follows from the theorem +we proved in the second or third week + + align:start position:0% +we proved in the second or third week + + + align:start position:0% +we proved in the second or third week +using for a analysis. So the whole case + + align:start position:0% +using for a analysis. So the whole case + + + align:start position:0% +using for a analysis. So the whole case +where C is minimal uh we we also already + + align:start position:0% +where C is minimal uh we we also already + + + align:start position:0% +where C is minimal uh we we also already +understand that + + align:start position:0% +understand that + + + align:start position:0% +understand that +okay and that leaves a case where B is + + align:start position:0% +okay and that leaves a case where B is + + + align:start position:0% +okay and that leaves a case where B is +minimal and that's like otherwise if + + align:start position:0% +minimal and that's like otherwise if + + + align:start position:0% +minimal and that's like otherwise if +neither of these things are true then B + + align:start position:0% +neither of these things are true then B + + + align:start position:0% +neither of these things are true then B +is minimal and um and so that's that's + + align:start position:0% +is minimal and um and so that's that's + + + align:start position:0% +is minimal and um and so that's that's +the content of this theorem. So this is + + align:start position:0% +the content of this theorem. So this is + + + align:start position:0% +the content of this theorem. So this is +the hard new thing + + align:start position:0% + + + + align:start position:0% + +in the uh OSRW thing. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +cool. + + align:start position:0% +cool. + + + align:start position:0% +cool. +Another little comment is that the the + + align:start position:0% +Another little comment is that the the + + + align:start position:0% +Another little comment is that the the +number of tubes is not my favorite + + align:start position:0% +number of tubes is not my favorite + + + align:start position:0% +number of tubes is not my favorite +parameter to keep track of. Um, my + + align:start position:0% +parameter to keep track of. Um, my + + + align:start position:0% +parameter to keep track of. Um, my +favorite parameter to keep track of is + + align:start position:0% +favorite parameter to keep track of is + + + align:start position:0% +favorite parameter to keep track of is +I'll call it R + + align:start position:0% +I'll call it R + + + align:start position:0% +I'll call it R +of of ET, + + align:start position:0% +of of ET, + + + align:start position:0% +of of ET, +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +which in words is like the typical + + align:start position:0% +which in words is like the typical + + + align:start position:0% +which in words is like the typical +number + + align:start position:0% +number + + + align:start position:0% +number +of delta balls + + align:start position:0% +of delta balls + + + align:start position:0% +of delta balls +of E on a typical tube of T. + + align:start position:0% + + + + align:start position:0% + +Um so let's make a uh + + align:start position:0% +Um so let's make a uh + + + align:start position:0% +Um so let's make a uh +let's make a picture. Um so we have some + + align:start position:0% +let's make a picture. Um so we have some + + + align:start position:0% +let's make a picture. Um so we have some +delta balls and then we have some delta + + align:start position:0% +delta balls and then we have some delta + + + align:start position:0% +delta balls and then we have some delta +tubes going through them + + align:start position:0% +tubes going through them + + + align:start position:0% +tubes going through them +and in in an interesting scenario each + + align:start position:0% +and in in an interesting scenario each + + + align:start position:0% +and in in an interesting scenario each +tube will have many balls in it and r is + + align:start position:0% +tube will have many balls in it and r is + + + align:start position:0% +tube will have many balls in it and r is +this number of balls in a tube. Okay. + + align:start position:0% +this number of balls in a tube. Okay. + + + align:start position:0% +this number of balls in a tube. Okay. +So algebraically + + align:start position:0% +So algebraically + + + align:start position:0% +So algebraically +by double counting + + align:start position:0% +by double counting + + + align:start position:0% +by double counting +number of balls in a tube would be the + + align:start position:0% +number of balls in a tube would be the + + + align:start position:0% +number of balls in a tube would be the +number of points times the number of + + align:start position:0% +number of points times the number of + + + align:start position:0% +number of points times the number of +tubes going through a point divided by + + align:start position:0% +tubes going through a point divided by + + + align:start position:0% +tubes going through a point divided by +uh the number of tubes. So that would be + + align:start position:0% +uh the number of tubes. So that would be + + + align:start position:0% +uh the number of tubes. So that would be +the algebraic definition of r. And then + + align:start position:0% +the algebraic definition of r. And then + + + align:start position:0% +the algebraic definition of r. And then +it's easy to convert bounds for t into + + align:start position:0% +it's easy to convert bounds for t into + + + align:start position:0% +it's easy to convert bounds for t into +bounds for r. So our theorem is + + align:start position:0% +bounds for r. So our theorem is + + + align:start position:0% +bounds for r. So our theorem is +equivalent to + + align:start position:0% + + + + align:start position:0% + +um that r is upper bounded by the + + align:start position:0% +um that r is upper bounded by the + + + align:start position:0% +um that r is upper bounded by the +maximum of three things. Scenario one is + + align:start position:0% +maximum of three things. Scenario one is + + + align:start position:0% +maximum of three things. Scenario one is +a. So scenario one the number of balls + + align:start position:0% +a. So scenario one the number of balls + + + align:start position:0% +a. So scenario one the number of balls +per tube is one which is always easy to + + align:start position:0% +per tube is one which is always easy to + + + align:start position:0% +per tube is one which is always easy to +arrange. + + align:start position:0% +arrange. + + + align:start position:0% +arrange. +Uh b you have to do a little + + align:start position:0% +Uh b you have to do a little + + + align:start position:0% +Uh b you have to do a little +computation. It works out to this. + + align:start position:0% +computation. It works out to this. + + + align:start position:0% +computation. It works out to this. +I don't really care what the exponent. + + align:start position:0% +I don't really care what the exponent. + + + align:start position:0% +I don't really care what the exponent. +It's not important what the exponents + + align:start position:0% +It's not important what the exponents + + + align:start position:0% +It's not important what the exponents +are. And C is delta to the uh t + one. + + align:start position:0% +are. And C is delta to the uh t + one. + + + align:start position:0% +are. And C is delta to the uh t + one. +Okay. And this delta to the t + one has + + align:start position:0% +Okay. And this delta to the t + one has + + + align:start position:0% +Okay. And this delta to the t + one has +a nice interpretation which might + + align:start position:0% +a nice interpretation which might + + + align:start position:0% +a nice interpretation which might +clarify a little bit what we mean by + + align:start position:0% +clarify a little bit what we mean by + + + align:start position:0% +clarify a little bit what we mean by +this random case. So if um e is a set is + + align:start position:0% +this random case. So if um e is a set is + + + align:start position:0% +this random case. So if um e is a set is +a delta tc set. So the size of e is + + align:start position:0% +a delta tc set. So the size of e is + + + align:start position:0% +a delta tc set. So the size of e is +delta to the minus t. Uh let me say it + + align:start position:0% +delta to the minus t. Uh let me say it + + + align:start position:0% +delta to the minus t. Uh let me say it +this way. Suppose that E + + align:start position:0% +this way. Suppose that E + + + align:start position:0% +this way. Suppose that E +is a set of delta to the minus T delta + + align:start position:0% +is a set of delta to the minus T delta + + + align:start position:0% +is a set of delta to the minus T delta +balls in the unit ball. + + align:start position:0% +balls in the unit ball. + + + align:start position:0% +balls in the unit ball. +And then I take the average over any + + align:start position:0% +And then I take the average over any + + + align:start position:0% +And then I take the average over any +choice of delta by one rectangles of um + + align:start position:0% +choice of delta by one rectangles of um + + + align:start position:0% +choice of delta by one rectangles of um +the number of delta balls that the + + align:start position:0% +the number of delta balls that the + + + align:start position:0% +the number of delta balls that the +rectangle covers. You would get delta to + + align:start position:0% +rectangle covers. You would get delta to + + + align:start position:0% +rectangle covers. You would get delta to +the minus t + 1. + + align:start position:0% +the minus t + 1. + + + align:start position:0% +the minus t + 1. +So it's not difficult to locate + + align:start position:0% +So it's not difficult to locate + + + align:start position:0% +So it's not difficult to locate +rectangles with that richness. Almost + + align:start position:0% +rectangles with that richness. Almost + + + align:start position:0% +rectangles with that richness. Almost +any rectangle would do the job. And + + align:start position:0% +any rectangle would do the job. And + + + align:start position:0% +any rectangle would do the job. And +scenario C is when the rectangles just + + align:start position:0% +scenario C is when the rectangles just + + + align:start position:0% +scenario C is when the rectangles just +have this average richness. There's + + align:start position:0% +have this average richness. There's + + + align:start position:0% +have this average richness. There's +really nothing special about them. + + align:start position:0% + + + + align:start position:0% + +Okay. So next let's remember. So their + + align:start position:0% +Okay. So next let's remember. So their + + + align:start position:0% +Okay. So next let's remember. So their +goal today is to talk about the ad + + align:start position:0% +goal today is to talk about the ad + + + align:start position:0% +goal today is to talk about the ad +regular case. So let's remember what + + align:start position:0% +regular case. So let's remember what + + + align:start position:0% +regular case. So let's remember what +what is the ad regular case. + + align:start position:0% + + + + align:start position:0% + +Okay. So we're going to suppose + + align:start position:0% +Okay. So we're going to suppose + + + align:start position:0% +Okay. So we're going to suppose +that E is uniform. + + align:start position:0% +that E is uniform. + + + align:start position:0% +that E is uniform. +So that means that our delta is some um + + align:start position:0% +So that means that our delta is some um + + + align:start position:0% +So that means that our delta is some um +capital delta to the m where m is a + + align:start position:0% +capital delta to the m where m is a + + + align:start position:0% +capital delta to the m where m is a +large number + + align:start position:0% + + + + align:start position:0% + +and the uniformity is that if I take e + + align:start position:0% +and the uniformity is that if I take e + + + align:start position:0% +and the uniformity is that if I take e +and I intersect it with a cube of side + + align:start position:0% +and I intersect it with a cube of side + + + align:start position:0% +and I intersect it with a cube of side +length delta to the j and I ask about + + align:start position:0% +length delta to the j and I ask about + + + align:start position:0% +length delta to the j and I ask about +its delta to the j + one covering number + + align:start position:0% +its delta to the j + one covering number + + + align:start position:0% +its delta to the j + one covering number +that's around some uh beta j + + align:start position:0% +that's around some uh beta j + + + align:start position:0% +that's around some uh beta j +for all the iatic + + align:start position:0% +for all the iatic + + + align:start position:0% +for all the iatic +Q delta J um that intersect E. + + align:start position:0% + + + + align:start position:0% + +Okay, so these beta J are the branching + + align:start position:0% +Okay, so these beta J are the branching + + + align:start position:0% +Okay, so these beta J are the branching +numbers. We drew pictures last time to + + align:start position:0% +numbers. We drew pictures last time to + + + align:start position:0% +numbers. We drew pictures last time to +illustrate what they mean. Um and so + + align:start position:0% +illustrate what they mean. Um and so + + + align:start position:0% +illustrate what they mean. Um and so +definition would be that E is C L4 is to + + align:start position:0% +definition would be that E is C L4 is to + + + align:start position:0% +definition would be that E is C L4 is to +be regular. So actually let's say it's a + + align:start position:0% +be regular. So actually let's say it's a + + + align:start position:0% +be regular. So actually let's say it's a +delta t c a d regular set + + align:start position:0% +delta t c a d regular set + + + align:start position:0% +delta t c a d regular set +f um has a this branching structure like + + align:start position:0% +f um has a this branching structure like + + + align:start position:0% +f um has a this branching structure like +above and um if I take the product j = 1 + + align:start position:0% +above and um if I take the product j = 1 + + + align:start position:0% +above and um if I take the product j = 1 +to capital j of beta j. So that would be + + align:start position:0% +to capital j of beta j. So that would be + + + align:start position:0% +to capital j of beta j. So that would be +the delta j covering number delta to the + + align:start position:0% +the delta j covering number delta to the + + + align:start position:0% +the delta j covering number delta to the +j covering number of our set. + + align:start position:0% +j covering number of our set. + + + align:start position:0% +j covering number of our set. +um + + align:start position:0% +um + + + align:start position:0% +um +it is at most C * delta to the J to the + + align:start position:0% +it is at most C * delta to the J to the + + + align:start position:0% +it is at most C * delta to the J to the +minus T and it is at least 1 / C * delta + + align:start position:0% +minus T and it is at least 1 / C * delta + + + align:start position:0% +minus T and it is at least 1 / C * delta +to the J to the minus T. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% + + + + align:start position:0% + +So, let's label all these hypotheses in + + align:start position:0% +So, let's label all these hypotheses in + + + align:start position:0% +So, let's label all these hypotheses in +our theorem by each our hypothesis. + + align:start position:0% + + + + align:start position:0% + +And what we'd like to understand is + + align:start position:0% +And what we'd like to understand is + + + align:start position:0% +And what we'd like to understand is +given these hypotheses, how big could R + + align:start position:0% +given these hypotheses, how big could R + + + align:start position:0% +given these hypotheses, how big could R +be? + + align:start position:0% +be? + + + align:start position:0% +be? +And for for today we're going to talk + + align:start position:0% +And for for today we're going to talk + + + align:start position:0% +And for for today we're going to talk +about the AD regular case. So let's give + + align:start position:0% +about the AD regular case. So let's give + + + align:start position:0% +about the AD regular case. So let's give +that a name. So R A D of S T delta C + + align:start position:0% +that a name. So R A D of S T delta C + + + align:start position:0% +that a name. So R A D of S T delta C +that is the maximum + + align:start position:0% +that is the maximum + + + align:start position:0% +that is the maximum +over E and T obey our hypothesis + + align:start position:0% +over E and T obey our hypothesis + + + align:start position:0% +over E and T obey our hypothesis +and E is a + + align:start position:0% +and E is a + + + align:start position:0% +and E is a +delta T C a d regular + + align:start position:0% +delta T C a d regular + + + align:start position:0% +delta T C a d regular +of R of E and T. How big could it be in + + align:start position:0% +of R of E and T. How big could it be in + + + align:start position:0% +of R of E and T. How big could it be in +in this case? + + align:start position:0% +in this case? + + + align:start position:0% +in this case? +Okay, there's really a mouthful of + + align:start position:0% +Okay, there's really a mouthful of + + + align:start position:0% +Okay, there's really a mouthful of +parameters. So, let me just say to uh + + align:start position:0% +parameters. So, let me just say to uh + + + align:start position:0% +parameters. So, let me just say to uh +reduce a little bit for today, we'll + + align:start position:0% +reduce a little bit for today, we'll + + + align:start position:0% +reduce a little bit for today, we'll +have C equals 1. Um so, that means it's + + align:start position:0% +have C equals 1. Um so, that means it's + + + align:start position:0% +have C equals 1. Um so, that means it's +you know really ad regular and + + align:start position:0% +you know really ad regular and + + + align:start position:0% +you know really ad regular and +everything we say actually um will work + + align:start position:0% +everything we say actually um will work + + + align:start position:0% +everything we say actually um will work +for small C that are bigger than + + align:start position:0% + + + + align:start position:0% + +that will allow us to not write the + + align:start position:0% +that will allow us to not write the + + + align:start position:0% +that will allow us to not write the +letter C. And then s and t will not be + + align:start position:0% +letter C. And then s and t will not be + + + align:start position:0% +letter C. And then s and t will not be +changing through our arguments. So I + + align:start position:0% +changing through our arguments. So I + + + align:start position:0% +changing through our arguments. So I +won't write them every time. So now I'll + + align:start position:0% +won't write them every time. So now I'll + + + align:start position:0% +won't write them every time. So now I'll +just abbreviate it + + align:start position:0% +just abbreviate it + + + align:start position:0% +just abbreviate it +as r a d of dot. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +All right. So um + + align:start position:0% +All right. So um + + + align:start position:0% +All right. So um +so the theorem that orbit and smirkin + + align:start position:0% +so the theorem that orbit and smirkin + + + align:start position:0% +so the theorem that orbit and smirkin +proved is that they they proved this + + align:start position:0% +proved is that they they proved this + + + align:start position:0% +proved is that they they proved this +thing in the ad case. So r a d s delta + + align:start position:0% +thing in the ad case. So r a d s delta + + + align:start position:0% +thing in the ad case. So r a d s delta +is indeed bounded by + + align:start position:0% +is indeed bounded by + + + align:start position:0% +is indeed bounded by +that. + + align:start position:0% + + + + align:start position:0% + +I'm not sure I computed right. + + align:start position:0% +I'm not sure I computed right. + + + align:start position:0% +I'm not sure I computed right. +Got the minus signs wrong. + + align:start position:0% + + + + align:start position:0% + +So that's our goal for today is to + + align:start position:0% +So that's our goal for today is to + + + align:start position:0% +So that's our goal for today is to +understand this theorem which is a + + align:start position:0% +understand this theorem which is a + + + align:start position:0% +understand this theorem which is a +really important special case of that + + align:start position:0% +really important special case of that + + + align:start position:0% +really important special case of that +theorem. + + align:start position:0% + + + + align:start position:0% + +Cool. + + align:start position:0% +Cool. + + + align:start position:0% +Cool. +So maybe so it's clearly a special case + + align:start position:0% +So maybe so it's clearly a special case + + + align:start position:0% +So maybe so it's clearly a special case +of that theorem. Um and at first it + + align:start position:0% +of that theorem. Um and at first it + + + align:start position:0% +of that theorem. Um and at first it +might seem like a very special case + + align:start position:0% +might seem like a very special case + + + align:start position:0% +might seem like a very special case +because these branching function + + align:start position:0% +because these branching function + + + align:start position:0% +because these branching function +basically there's a huge range of what + + align:start position:0% +basically there's a huge range of what + + + align:start position:0% +basically there's a huge range of what +the branching function could be and ad + + align:start position:0% +the branching function could be and ad + + + align:start position:0% +the branching function could be and ad +regular is just one particular choice in + + align:start position:0% +regular is just one particular choice in + + + align:start position:0% +regular is just one particular choice in +this huge range but it's a particularly + + align:start position:0% +this huge range but it's a particularly + + + align:start position:0% +this huge range but it's a particularly +important case and we'll see tomorrow or + + align:start position:0% +important case and we'll see tomorrow or + + + align:start position:0% +important case and we'll see tomorrow or +next class that that this is really a + + align:start position:0% +next class that that this is really a + + + align:start position:0% +next class that that this is really a +crucial case plays a big role in + + align:start position:0% +crucial case plays a big role in + + + align:start position:0% +crucial case plays a big role in +understanding the theorem in general. + + align:start position:0% +understanding the theorem in general. + + + align:start position:0% +understanding the theorem in general. +Okay, + + align:start position:0% + + + + align:start position:0% + +cool. Um, yeah. So, so it was a really + + align:start position:0% +cool. Um, yeah. So, so it was a really + + + align:start position:0% +cool. Um, yeah. So, so it was a really +it was a really important realization in + + align:start position:0% +it was a really important realization in + + + align:start position:0% +it was a really important realization in +thinking about this theorem that we + + align:start position:0% +thinking about this theorem that we + + + align:start position:0% +thinking about this theorem that we +should break it into cases. The + + align:start position:0% +should break it into cases. The + + + align:start position:0% +should break it into cases. The +different cases have their different + + align:start position:0% +different cases have their different + + + align:start position:0% +different cases have their different +things that are useful and their + + align:start position:0% +things that are useful and their + + + align:start position:0% +things that are useful and their +different things that are difficult um + + align:start position:0% +different things that are difficult um + + + align:start position:0% +different things that are difficult um +and um and and so that recognition is is + + align:start position:0% +and um and and so that recognition is is + + + align:start position:0% +and um and and so that recognition is is +key. So the next thing I want to try to + + align:start position:0% +key. So the next thing I want to try to + + + align:start position:0% +key. So the next thing I want to try to +talk about is like what is special about + + align:start position:0% +talk about is like what is special about + + + align:start position:0% +talk about is like what is special about +ad regular sets that we could use to to + + align:start position:0% +ad regular sets that we could use to to + + + align:start position:0% +ad regular sets that we could use to to +get a handle on them um that we couldn't + + align:start position:0% +get a handle on them um that we couldn't + + + align:start position:0% +get a handle on them um that we couldn't +use just for the for the general setup. + + align:start position:0% +use just for the for the general setup. + + + align:start position:0% +use just for the for the general setup. +All right. + + align:start position:0% + + + + align:start position:0% + +Okay. So this proof is is quite + + align:start position:0% +Okay. So this proof is is quite + + + align:start position:0% +Okay. So this proof is is quite +difficult. We won't do all of it, but I + + align:start position:0% +difficult. We won't do all of it, but I + + + align:start position:0% +difficult. We won't do all of it, but I +would like to share some key ideas about + + align:start position:0% +would like to share some key ideas about + + + align:start position:0% +would like to share some key ideas about +it which I think are really cool and and + + align:start position:0% +it which I think are really cool and and + + + align:start position:0% +it which I think are really cool and and +are like sort of worth taking with you + + align:start position:0% +are like sort of worth taking with you + + + align:start position:0% +are like sort of worth taking with you +away from this class. + + align:start position:0% +away from this class. + + + align:start position:0% +away from this class. +All right. + + align:start position:0% + + + + align:start position:0% + +Okay, so in a nutshell, the important + + align:start position:0% +Okay, so in a nutshell, the important + + + align:start position:0% +Okay, so in a nutshell, the important +special thing about ad regular sets is + + align:start position:0% +special thing about ad regular sets is + + + align:start position:0% +special thing about ad regular sets is +in this lema that has a one board proof + + align:start position:0% +in this lema that has a one board proof + + + align:start position:0% +in this lema that has a one board proof +which is called the sub multiplicative + + align:start position:0% +which is called the sub multiplicative + + + align:start position:0% +which is called the sub multiplicative +lema. + + align:start position:0% + + + + align:start position:0% + +Okay, so it says that RA a delta, let me + + align:start position:0% +Okay, so it says that RA a delta, let me + + + align:start position:0% +Okay, so it says that RA a delta, let me +put it this way. If delta is delta 1 * + + align:start position:0% +put it this way. If delta is delta 1 * + + + align:start position:0% +put it this way. If delta is delta 1 * +delta 2, then RA a delta is bounded by + + align:start position:0% +delta 2, then RA a delta is bounded by + + + align:start position:0% +delta 2, then RA a delta is bounded by +with a little bit of fudge RA a delta 1 + + align:start position:0% +with a little bit of fudge RA a delta 1 + + + align:start position:0% +with a little bit of fudge RA a delta 1 +time ra + + align:start position:0% +time ra + + + align:start position:0% +time ra +delta 2. + + align:start position:0% + + + + align:start position:0% + +It is sub multiplicative. + + align:start position:0% +It is sub multiplicative. + + + align:start position:0% +It is sub multiplicative. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +and + + align:start position:0% +and + + + align:start position:0% +and +it follows from understanding thinking a + + align:start position:0% +it follows from understanding thinking a + + + align:start position:0% +it follows from understanding thinking a +lot about a picture of an ad regular + + align:start position:0% +lot about a picture of an ad regular + + + align:start position:0% +lot about a picture of an ad regular +set. + + align:start position:0% +set. + + + align:start position:0% +set. +Okay. So + + align:start position:0% +Okay. So + + + align:start position:0% +Okay. So +remember that E is a set of delta balls + + align:start position:0% +remember that E is a set of delta balls + + + align:start position:0% +remember that E is a set of delta balls +and T is a set of delta tubes and we're + + align:start position:0% +and T is a set of delta tubes and we're + + + align:start position:0% +and T is a set of delta tubes and we're +going to imagine thickening them. + + align:start position:0% +going to imagine thickening them. + + + align:start position:0% +going to imagine thickening them. +So, so in this setup here, um, delta is + + align:start position:0% +So, so in this setup here, um, delta is + + + align:start position:0% +So, so in this setup here, um, delta is +smaller than delta 1 and delta 2, which + + align:start position:0% +smaller than delta 1 and delta 2, which + + + align:start position:0% +smaller than delta 1 and delta 2, which +are smaller than one. So, delta 1 and + + align:start position:0% +are smaller than one. So, delta 1 and + + + align:start position:0% +are smaller than one. So, delta 1 and +delta 2 are each bigger than delta. So, + + align:start position:0% +delta 2 are each bigger than delta. So, + + + align:start position:0% +delta 2 are each bigger than delta. So, +I'm going to thicken them, and I'll get + + align:start position:0% +I'm going to thicken them, and I'll get + + + align:start position:0% +I'm going to thicken them, and I'll get +E1, + + align:start position:0% +E1, + + + align:start position:0% +E1, +I'll call it, which are the delta 1 + + align:start position:0% +I'll call it, which are the delta 1 + + + align:start position:0% +I'll call it, which are the delta 1 +balls around E, and T1, which are delta + + align:start position:0% +balls around E, and T1, which are delta + + + align:start position:0% +balls around E, and T1, which are delta +1 tools. + + align:start position:0% + + + + align:start position:0% + +All right. So, what does it look like? + + align:start position:0% +All right. So, what does it look like? + + + align:start position:0% +All right. So, what does it look like? +Let's think about E and thickening E. + + align:start position:0% + + + + align:start position:0% + +So here is E1 is this bunch of circles. + + align:start position:0% +So here is E1 is this bunch of circles. + + + align:start position:0% +So here is E1 is this bunch of circles. +Each circle has radius delta 1 + + align:start position:0% +Each circle has radius delta 1 + + + align:start position:0% +Each circle has radius delta 1 +and inside of those circles there are + + align:start position:0% +and inside of those circles there are + + + align:start position:0% +and inside of those circles there are +some delta balls + + align:start position:0% + + + + align:start position:0% + +and those guys are my delta balls E. + + align:start position:0% + + + + align:start position:0% + +Okay. Now, + + align:start position:0% +Okay. Now, + + + align:start position:0% +Okay. Now, +um, T1 are some delta 1 tubes. + + align:start position:0% +um, T1 are some delta 1 tubes. + + + align:start position:0% +um, T1 are some delta 1 tubes. +So, they might look sort of like this. + + align:start position:0% + + + + align:start position:0% + +Let's put one more ball up here. + + align:start position:0% + + + + align:start position:0% + +That looks like that. So, those are my + + align:start position:0% +That looks like that. So, those are my + + + align:start position:0% +That looks like that. So, those are my +fat tubes. T1 + + align:start position:0% + + + + align:start position:0% + +Um and then there are inside of them + + align:start position:0% +Um and then there are inside of them + + + align:start position:0% +Um and then there are inside of them +there are some delta tubes T2 + + align:start position:0% + + + + align:start position:0% + +that um + + align:start position:0% +that um + + + align:start position:0% +that um +there are too many but I'll try to give + + align:start position:0% +there are too many but I'll try to give + + + align:start position:0% +there are too many but I'll try to give +some idea. So, + + align:start position:0% +some idea. So, + + + align:start position:0% +some idea. So, +so through this point here, + + align:start position:0% +so through this point here, + + + align:start position:0% +so through this point here, +there might be a couple of red tubes + + align:start position:0% +there might be a couple of red tubes + + + align:start position:0% +there might be a couple of red tubes +that are inside of that orange tube. And + + align:start position:0% +that are inside of that orange tube. And + + + align:start position:0% +that are inside of that orange tube. And +then there might be a couple of red + + align:start position:0% +then there might be a couple of red + + + align:start position:0% +then there might be a couple of red +tubes + + align:start position:0% +tubes + + + align:start position:0% +tubes +that are inside of that orange tube. + + align:start position:0% + + + + align:start position:0% + +Okay? And I just drew the ones through + + align:start position:0% +Okay? And I just drew the ones through + + + align:start position:0% +Okay? And I just drew the ones through +this point. Experience has taught me + + align:start position:0% +this point. Experience has taught me + + + align:start position:0% +this point. Experience has taught me +that if I draw more, this picture will + + align:start position:0% +that if I draw more, this picture will + + + align:start position:0% +that if I draw more, this picture will +get too messy. But you should imagine + + align:start position:0% +get too messy. But you should imagine + + + align:start position:0% +get too messy. But you should imagine +that this is happening at every point. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So + + align:start position:0% + + + + align:start position:0% + +first observation is that E1 and T1 obey + + align:start position:0% +first observation is that E1 and T1 obey + + + align:start position:0% +first observation is that E1 and T1 obey +the hypothesis of our theorem + + align:start position:0% + + + + align:start position:0% + +because actually if so if you take a + + align:start position:0% +because actually if so if you take a + + + align:start position:0% +because actually if so if you take a +delta t set of balls and you thicken + + align:start position:0% +delta t set of balls and you thicken + + + align:start position:0% +delta t set of balls and you thicken +them up to radius delta 1, you get a + + align:start position:0% +them up to radius delta 1, you get a + + + align:start position:0% +them up to radius delta 1, you get a +delta onet set of balls + + align:start position:0% +delta onet set of balls + + + align:start position:0% +delta onet set of balls +at least if because if it's uniform + + align:start position:0% +at least if because if it's uniform + + + align:start position:0% +at least if because if it's uniform +and um if you Look at who's going + + align:start position:0% +and um if you Look at who's going + + + align:start position:0% +and um if you Look at who's going +through this point. Uh we have a delta s + + align:start position:0% +through this point. Uh we have a delta s + + + align:start position:0% +through this point. Uh we have a delta s +set of directions leaving that point. + + align:start position:0% +set of directions leaving that point. + + + align:start position:0% +set of directions leaving that point. +And if you thicken them up a little bit, + + align:start position:0% +And if you thicken them up a little bit, + + + align:start position:0% +And if you thicken them up a little bit, +you get um the directions corresponding + + align:start position:0% +you get um the directions corresponding + + + align:start position:0% +you get um the directions corresponding +to the orange tubes. And that will be a + + align:start position:0% +to the orange tubes. And that will be a + + + align:start position:0% +to the orange tubes. And that will be a +delta 1 s set of directions. + + align:start position:0% +delta 1 s set of directions. + + + align:start position:0% +delta 1 s set of directions. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +great. Um then + + align:start position:0% + + + + align:start position:0% + +yeah. Okay, so + + align:start position:0% +yeah. Okay, so + + + align:start position:0% +yeah. Okay, so +let let me put the punch line and then + + align:start position:0% +let let me put the punch line and then + + + align:start position:0% +let let me put the punch line and then +we'll think through why this works. + + align:start position:0% +we'll think through why this works. + + + align:start position:0% +we'll think through why this works. +So R A D of delta that's the number of + + align:start position:0% +So R A D of delta that's the number of + + + align:start position:0% +So R A D of delta that's the number of +white balls in a red tube, but that's + + align:start position:0% +white balls in a red tube, but that's + + + align:start position:0% +white balls in a red tube, but that's +bounded by the number of delta 1 balls + + align:start position:0% +bounded by the number of delta 1 balls + + + align:start position:0% +bounded by the number of delta 1 balls +in a delta 1 tube. + + align:start position:0% + + + + align:start position:0% + +Right? So I look in this orange tube, I + + align:start position:0% +Right? So I look in this orange tube, I + + + align:start position:0% +Right? So I look in this orange tube, I +see how many of these balls there are + + align:start position:0% +see how many of these balls there are + + + align:start position:0% +see how many of these balls there are +times + + align:start position:0% +times + + + align:start position:0% +times +the number of delta balls + + align:start position:0% +the number of delta balls + + + align:start position:0% +the number of delta balls +in a delta tube within + + align:start position:0% +in a delta tube within + + + align:start position:0% +in a delta tube within +one delta 1 bar. + + align:start position:0% + + + + align:start position:0% + +So if I'm looking at this at this red + + align:start position:0% +So if I'm looking at this at this red + + + align:start position:0% +So if I'm looking at this at this red +tube here, I want to know how many delta + + align:start position:0% +tube here, I want to know how many delta + + + align:start position:0% +tube here, I want to know how many delta +balls are in it. It's bounded by the + + align:start position:0% +balls are in it. It's bounded by the + + + align:start position:0% +balls are in it. It's bounded by the +number of big balls that it enters + + align:start position:0% +number of big balls that it enters + + + align:start position:0% +number of big balls that it enters +times the number of little balls in each + + align:start position:0% +times the number of little balls in each + + + align:start position:0% +times the number of little balls in each +of the big balls. + + align:start position:0% + + + + align:start position:0% + +Okay. So, we'd like to relate these two + + align:start position:0% +Okay. So, we'd like to relate these two + + + align:start position:0% +Okay. So, we'd like to relate these two +things to our problem at a coarser + + align:start position:0% +things to our problem at a coarser + + + align:start position:0% +things to our problem at a coarser +scale. + + align:start position:0% +scale. + + + align:start position:0% +scale. +And this one here well E1 and T1 obey + + align:start position:0% +And this one here well E1 and T1 obey + + + align:start position:0% +And this one here well E1 and T1 obey +our hypothesis. So this this one here is + + align:start position:0% +our hypothesis. So this this one here is + + + align:start position:0% +our hypothesis. So this this one here is +bounded by RA a D of delta 1. + + align:start position:0% + + + + align:start position:0% + +Now here + + align:start position:0% +Now here + + + align:start position:0% +Now here +if you take E and T and you restrict + + align:start position:0% +if you take E and T and you restrict + + + align:start position:0% +if you take E and T and you restrict +them + + align:start position:0% +them + + + align:start position:0% +them +to a delta 1 ball + + align:start position:0% +to a delta 1 ball + + + align:start position:0% +to a delta 1 ball +and then you magnify it to bring it up + + align:start position:0% +and then you magnify it to bring it up + + + align:start position:0% +and then you magnify it to bring it up +to scale one. Um this also obeys our + + align:start position:0% +to scale one. Um this also obeys our + + + align:start position:0% +to scale one. Um this also obeys our +hypothesis. + + align:start position:0% +hypothesis. + + + align:start position:0% +hypothesis. +So if you look inside of here, you see a + + align:start position:0% +So if you look inside of here, you see a + + + align:start position:0% +So if you look inside of here, you see a +little delta TC sat a little a little uh + + align:start position:0% +little delta TC sat a little a little uh + + + align:start position:0% +little delta TC sat a little a little uh +you know this this this + + align:start position:0% +you know this this this + + + align:start position:0% +you know this this this +and and these red tubes. That's the same + + align:start position:0% +and and these red tubes. That's the same + + + align:start position:0% +and and these red tubes. That's the same +situation on a smaller scale or on a + + align:start position:0% +situation on a smaller scale or on a + + + align:start position:0% +situation on a smaller scale or on a +coarser scale. So when you when you blow + + align:start position:0% +coarser scale. So when you when you blow + + + align:start position:0% +coarser scale. So when you when you blow +this up um uh if you blow it up then you + + align:start position:0% +this up um uh if you blow it up then you + + + align:start position:0% +this up um uh if you blow it up then you +get delta 2 balls + + align:start position:0% +get delta 2 balls + + + align:start position:0% +get delta 2 balls +and delta 2 tubes + + align:start position:0% +and delta 2 tubes + + + align:start position:0% +and delta 2 tubes +in the unit ball. + + align:start position:0% +in the unit ball. + + + align:start position:0% +in the unit ball. +So this guy is bounded by the uh ra of + + align:start position:0% +So this guy is bounded by the uh ra of + + + align:start position:0% +So this guy is bounded by the uh ra of +delta 2. + + align:start position:0% + + + + align:start position:0% + +Okay, I'm going call this claim one and + + align:start position:0% +Okay, I'm going call this claim one and + + + align:start position:0% +Okay, I'm going call this claim one and +claim two. + + align:start position:0% + + + + align:start position:0% + +All right, + + align:start position:0% +All right, + + + align:start position:0% +All right, +so this picture is perhaps the most + + align:start position:0% +so this picture is perhaps the most + + + align:start position:0% +so this picture is perhaps the most +important thing uh to take away from + + align:start position:0% +important thing uh to take away from + + + align:start position:0% +important thing uh to take away from +this proof and this class. So take a + + align:start position:0% +this proof and this class. So take a + + + align:start position:0% +this proof and this class. So take a +moment and see if you have questions + + align:start position:0% +moment and see if you have questions + + + align:start position:0% +moment and see if you have questions +about this proof. + + align:start position:0% + + + + align:start position:0% + +ready to verify. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. Okay. So the question is do we + + align:start position:0% +>> Yeah. Okay. So the question is do we + + + align:start position:0% +>> Yeah. Okay. So the question is do we +need to check that everything is ad + + align:start position:0% +need to check that everything is ad + + + align:start position:0% +need to check that everything is ad +regular? Yeah. Okay. So let me add to + + align:start position:0% +regular? Yeah. Okay. So let me add to + + + align:start position:0% +regular? Yeah. Okay. So let me add to +these claims and then if we want to + + align:start position:0% +these claims and then if we want to + + + align:start position:0% +these claims and then if we want to +we'll we'll prove we can add details to + + align:start position:0% +we'll we'll prove we can add details to + + + align:start position:0% +we'll we'll prove we can add details to +the proof of these claims. E E1 and T1 + + align:start position:0% +the proof of these claims. E E1 and T1 + + + align:start position:0% +the proof of these claims. E E1 and T1 +obey the hypothesis and they're ad + + align:start position:0% +obey the hypothesis and they're ad + + + align:start position:0% +obey the hypothesis and they're ad +regular. And we need that this blow up + + align:start position:0% +regular. And we need that this blow up + + + align:start position:0% +regular. And we need that this blow up +here obeys the hypothesis and it's ad + + align:start position:0% +here obeys the hypothesis and it's ad + + + align:start position:0% +here obeys the hypothesis and it's ad +regular. And if you believe those two + + align:start position:0% +regular. And if you believe those two + + + align:start position:0% +regular. And if you believe those two +things, then you can plug you just plug + + align:start position:0% +things, then you can plug you just plug + + + align:start position:0% +things, then you can plug you just plug +in and you get that. + + align:start position:0% + + + + align:start position:0% + +Yeah. And we we can talk a little bit + + align:start position:0% +Yeah. And we we can talk a little bit + + + align:start position:0% +Yeah. And we we can talk a little bit +more about those two things if you want. + + align:start position:0% +more about those two things if you want. + + + align:start position:0% +more about those two things if you want. +Are there other questions or comments? + + align:start position:0% + + + + align:start position:0% + +Okay. So, I'll probably add a little + + align:start position:0% +Okay. So, I'll probably add a little + + + align:start position:0% +Okay. So, I'll probably add a little +more, but actually I wanted to ask you + + align:start position:0% +more, but actually I wanted to ask you + + + align:start position:0% +more, but actually I wanted to ask you +all a question. Um, in this argument, + + align:start position:0% +all a question. Um, in this argument, + + + align:start position:0% +all a question. Um, in this argument, +where did we take advantage of the fact + + align:start position:0% +where did we take advantage of the fact + + + align:start position:0% +where did we take advantage of the fact +that the original E was ad regular? + + align:start position:0% + + + + align:start position:0% + +Yeah. Jonathan, + + align:start position:0% +Yeah. Jonathan, + + + align:start position:0% +Yeah. Jonathan, +>> is it like picking one delta one ball + + align:start position:0% +>> is it like picking one delta one ball + + + align:start position:0% +>> is it like picking one delta one ball +and magnifying it? + + align:start position:0% +and magnifying it? + + + align:start position:0% +and magnifying it? +>> Yeah. So, it's related to when we picked + + align:start position:0% +>> Yeah. So, it's related to when we picked + + + align:start position:0% +>> Yeah. So, it's related to when we picked +this one delta 1 ball and magnified it. + + align:start position:0% +this one delta 1 ball and magnified it. + + + align:start position:0% +this one delta 1 ball and magnified it. +Yeah. So, so let's talk about one and + + align:start position:0% +Yeah. So, so let's talk about one and + + + align:start position:0% +Yeah. So, so let's talk about one and +two a little more carefully. Um, + + align:start position:0% + + + + align:start position:0% + +all right. + + align:start position:0% + + + + align:start position:0% + +So let's discuss + + align:start position:0% +So let's discuss + + + align:start position:0% +So let's discuss +one and two. Okay. So point one if e and + + align:start position:0% +one and two. Okay. So point one if e and + + + align:start position:0% +one and two. Okay. So point one if e and +tx are uniform which we can pretty much + + align:start position:0% +tx are uniform which we can pretty much + + + align:start position:0% +tx are uniform which we can pretty much +assume in the which we can assume from + + align:start position:0% +assume in the which we can assume from + + + align:start position:0% +assume in the which we can assume from +the beginning with a little pruning + + align:start position:0% +the beginning with a little pruning + + + align:start position:0% +the beginning with a little pruning +um then um + + align:start position:0% +um then um + + + align:start position:0% +um then um +e delta t implies that e1 is delta1 t + + align:start position:0% +e delta t implies that e1 is delta1 t + + + align:start position:0% +e delta t implies that e1 is delta1 t +and + + align:start position:0% +and + + + align:start position:0% +and +tx + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +delta s implies that t1x + + align:start position:0% +delta s implies that t1x + + + align:start position:0% +delta s implies that t1x +is is delta 1x. + + align:start position:0% + + + + align:start position:0% + +Okay. And also uh if E is ad regular + + align:start position:0% +Okay. And also uh if E is ad regular + + + align:start position:0% +Okay. And also uh if E is ad regular +it implies that E1 is AD regular + + align:start position:0% +it implies that E1 is AD regular + + + align:start position:0% +it implies that E1 is AD regular +because this is saying all the branching + + align:start position:0% +because this is saying all the branching + + + align:start position:0% +because this is saying all the branching +numbers of E are the same as each other + + align:start position:0% +numbers of E are the same as each other + + + align:start position:0% +numbers of E are the same as each other +and this is saying that all the + + align:start position:0% +and this is saying that all the + + + align:start position:0% +and this is saying that all the +branching numbers of E down to the depth + + align:start position:0% +branching numbers of E down to the depth + + + align:start position:0% +branching numbers of E down to the depth +of delta 1 are the same as each other. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +we didn't need E to be ad regular to do + + align:start position:0% +we didn't need E to be ad regular to do + + + align:start position:0% +we didn't need E to be ad regular to do +this or this, + + align:start position:0% +this or this, + + + align:start position:0% +this or this, +but it comes in in part two. So + + align:start position:0% +but it comes in in part two. So + + + align:start position:0% +but it comes in in part two. So +because E is a deregular + + align:start position:0% +because E is a deregular + + + align:start position:0% +because E is a deregular +then we get that if you take E and you + + align:start position:0% +then we get that if you take E and you + + + align:start position:0% +then we get that if you take E and you +intersect it with a small ball and + + align:start position:0% +intersect it with a small ball and + + + align:start position:0% +intersect it with a small ball and +magnify it + + align:start position:0% +magnify it + + + align:start position:0% +magnify it +then this is uh a delta I guess delta 2 + + align:start position:0% +then this is uh a delta I guess delta 2 + + + align:start position:0% +then this is uh a delta I guess delta 2 +t and a d regular. + + align:start position:0% + + + + align:start position:0% + +So let me illustrate this with pictures + + align:start position:0% +So let me illustrate this with pictures + + + align:start position:0% +So let me illustrate this with pictures +instead of equations. So what does it + + align:start position:0% +instead of equations. So what does it + + + align:start position:0% +instead of equations. So what does it +look like? Let's draw an ad regular set + + align:start position:0% +look like? Let's draw an ad regular set + + + align:start position:0% +look like? Let's draw an ad regular set +and a not regular set and we'll look at + + align:start position:0% +and a not regular set and we'll look at + + + align:start position:0% +and a not regular set and we'll look at +both of them. Okay. So if E is ad + + align:start position:0% +both of them. Okay. So if E is ad + + + align:start position:0% +both of them. Okay. So if E is ad +regular + + align:start position:0% +regular + + + align:start position:0% +regular +what I do + + align:start position:0% + + + + align:start position:0% + +I pick say four of them. + + align:start position:0% + + + + align:start position:0% + +Let me do this in the color. + + align:start position:0% + + + + align:start position:0% + +Okay. Then for each one that I picked, I + + align:start position:0% +Okay. Then for each one that I picked, I + + + align:start position:0% +Okay. Then for each one that I picked, I +subdivide it + + align:start position:0% + + + + align:start position:0% + +uh and I pick four of them. + + align:start position:0% + + + + align:start position:0% + +Okay, I'll stop drawing. You get the + + align:start position:0% +Okay, I'll stop drawing. You get the + + + align:start position:0% +Okay, I'll stop drawing. You get the +idea, right? Okay, now this is a self + + align:start position:0% +idea, right? Okay, now this is a self + + + align:start position:0% +idea, right? Okay, now this is a self +similar construction. If I take this + + align:start position:0% +similar construction. If I take this + + + align:start position:0% +similar construction. If I take this +thing in here and I blow it up, it's + + align:start position:0% +thing in here and I blow it up, it's + + + align:start position:0% +thing in here and I blow it up, it's +just like what I started with. So it + + align:start position:0% +just like what I started with. So it + + + align:start position:0% +just like what I started with. So it +will be a dere regular and it will be in + + align:start position:0% +will be a dere regular and it will be in + + + align:start position:0% +will be a dere regular and it will be in +particular a delta it will be a a delta + + align:start position:0% +particular a delta it will be a a delta + + + align:start position:0% +particular a delta it will be a a delta +t set for the appropriate delta. + + align:start position:0% +t set for the appropriate delta. + + + align:start position:0% +t set for the appropriate delta. +Okay what would it look like if e was + + align:start position:0% +Okay what would it look like if e was + + + align:start position:0% +Okay what would it look like if e was +not a d regular? + + align:start position:0% +not a d regular? + + + align:start position:0% +not a d regular? +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +for example, + + align:start position:0% +for example, + + + align:start position:0% +for example, +I might do the following thing. Might + + align:start position:0% +I might do the following thing. Might + + + align:start position:0% +I might do the following thing. Might +cut it into a 4x4 grid. And I might take + + align:start position:0% +cut it into a 4x4 grid. And I might take + + + align:start position:0% +cut it into a 4x4 grid. And I might take +all of the boxes. And then I could cut + + align:start position:0% +all of the boxes. And then I could cut + + + align:start position:0% +all of the boxes. And then I could cut +each of each one of them into a 4x4 grid + + align:start position:0% +each of each one of them into a 4x4 grid + + + align:start position:0% +each of each one of them into a 4x4 grid +and pick just one box. + + align:start position:0% +and pick just one box. + + + align:start position:0% +and pick just one box. +So this was the, you know, the well + + align:start position:0% +So this was the, you know, the well + + + align:start position:0% +So this was the, you know, the well +spaced example that we drew last time. + + align:start position:0% + + + + align:start position:0% + +Okay. So this whole thing is a delta t + + align:start position:0% +Okay. So this whole thing is a delta t + + + align:start position:0% +Okay. So this whole thing is a delta t +set. But if I took just one of these + + align:start position:0% +set. But if I took just one of these + + + align:start position:0% +set. But if I took just one of these +boxes, what I would see is much more + + align:start position:0% +boxes, what I would see is much more + + + align:start position:0% +boxes, what I would see is much more +concentrated. This is not a delta t set. + + align:start position:0% +concentrated. This is not a delta t set. + + + align:start position:0% +concentrated. This is not a delta t set. +So if I were to take this guy + + align:start position:0% + + + + align:start position:0% + +and take it out here and magnify it, + + align:start position:0% +and take it out here and magnify it, + + + align:start position:0% +and take it out here and magnify it, +then inside of here, I would just see + + align:start position:0% +then inside of here, I would just see + + + align:start position:0% +then inside of here, I would just see +this. This here is a blank T set. But + + align:start position:0% +this. This here is a blank T set. But + + + align:start position:0% +this. This here is a blank T set. But +this here is not a blank T- set. + + align:start position:0% +this here is not a blank T- set. + + + align:start position:0% +this here is not a blank T- set. +Whereas in the AD regular case, if I + + align:start position:0% +Whereas in the AD regular case, if I + + + align:start position:0% +Whereas in the AD regular case, if I +were to take one of these and bring it + + align:start position:0% +were to take one of these and bring it + + + align:start position:0% +were to take one of these and bring it +out and magnify it, then what I would + + align:start position:0% +out and magnify it, then what I would + + + align:start position:0% +out and magnify it, then what I would +see in here would be very similar to the + + align:start position:0% +see in here would be very similar to the + + + align:start position:0% +see in here would be very similar to the +original set. This is um + + align:start position:0% +original set. This is um + + + align:start position:0% +original set. This is um +similar to B. So this here is a + + align:start position:0% +similar to B. So this here is a + + + align:start position:0% +similar to B. So this here is a +blank T set and it's a dregular. And + + align:start position:0% +blank T set and it's a dregular. And + + + align:start position:0% +blank T set and it's a dregular. And +that thing in there is still a blank T + + align:start position:0% +that thing in there is still a blank T + + + align:start position:0% +that thing in there is still a blank T +set and it's still ad regular. + + align:start position:0% + + + + align:start position:0% + +Okay, so this is the special feature of + + align:start position:0% +Okay, so this is the special feature of + + + align:start position:0% +Okay, so this is the special feature of +ad regular. The word regular refers to + + align:start position:0% +ad regular. The word regular refers to + + + align:start position:0% +ad regular. The word regular refers to +the fact that all the different scales + + align:start position:0% +the fact that all the different scales + + + align:start position:0% +the fact that all the different scales +look the same. And so when we uh look + + align:start position:0% +look the same. And so when we uh look + + + align:start position:0% +look the same. And so when we uh look +inside this ball here, we have another + + align:start position:0% +inside this ball here, we have another + + + align:start position:0% +inside this ball here, we have another +example of our original problem at a + + align:start position:0% +example of our original problem at a + + + align:start position:0% +example of our original problem at a +coarser scale. And that feeds into an + + align:start position:0% +coarser scale. And that feeds into an + + + align:start position:0% +coarser scale. And that feeds into an +inductive argument and we can say for + + align:start position:0% +inductive argument and we can say for + + + align:start position:0% +inductive argument and we can say for +example we can say this sub + + align:start position:0% +example we can say this sub + + + align:start position:0% +example we can say this sub +multiplicative lema. + + align:start position:0% +multiplicative lema. + + + align:start position:0% +multiplicative lema. +>> Yeah first inequality over there do you + + align:start position:0% +>> Yeah first inequality over there do you + + + align:start position:0% +>> Yeah first inequality over there do you +need some sort of uniformity on the + + align:start position:0% +need some sort of uniformity on the + + + align:start position:0% +need some sort of uniformity on the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +cuz like the average and you're saying + + align:start position:0% +cuz like the average and you're saying + + + align:start position:0% +cuz like the average and you're saying +something like the average. + + align:start position:0% + + + + align:start position:0% + +>> Yeah that's right. That's right. So so + + align:start position:0% +>> Yeah that's right. That's right. So so + + + align:start position:0% +>> Yeah that's right. That's right. So so +um + + align:start position:0% +um + + + align:start position:0% +um +yes that is a good point. Okay, so the + + align:start position:0% +yes that is a good point. Okay, so the + + + align:start position:0% +yes that is a good point. Okay, so the +comment is that RA was defined as an + + align:start position:0% +comment is that RA was defined as an + + + align:start position:0% +comment is that RA was defined as an +average number of delta tubes per delta + + align:start position:0% +average number of delta tubes per delta + + + align:start position:0% +average number of delta tubes per delta +ball. And here I was pretending that all + + align:start position:0% +ball. And here I was pretending that all + + + align:start position:0% +ball. And here I was pretending that all +the tubes are average. Um so + + align:start position:0% +the tubes are average. Um so + + + align:start position:0% +the tubes are average. Um so +let's call this a proof sketch. + + align:start position:0% +let's call this a proof sketch. + + + align:start position:0% +let's call this a proof sketch. +Um you do need some uniformity. If you + + align:start position:0% +Um you do need some uniformity. If you + + + align:start position:0% +Um you do need some uniformity. If you +think back to the original setting, you + + align:start position:0% +think back to the original setting, you + + + align:start position:0% +think back to the original setting, you +know, you have the set E and then you + + align:start position:0% +know, you have the set E and then you + + + align:start position:0% +know, you have the set E and then you +draw all these tubes. You can sort them + + align:start position:0% +draw all these tubes. You can sort them + + + align:start position:0% +draw all these tubes. You can sort them +by how many delta tubes are in each one + + align:start position:0% +by how many delta tubes are in each one + + + align:start position:0% +by how many delta tubes are in each one +and you take the category that has the + + align:start position:0% +and you take the category that has the + + + align:start position:0% +and you take the category that has the +most delta tubes and that will still you + + align:start position:0% +most delta tubes and that will still you + + + align:start position:0% +most delta tubes and that will still you +can work with that. So you can do it you + + align:start position:0% +can work with that. So you can do it you + + + align:start position:0% +can work with that. So you can do it you +you you're correct. You we have to + + align:start position:0% +you you're correct. You we have to + + + align:start position:0% +you you're correct. You we have to +uniformize it. Um and it is possible to + + align:start position:0% +uniformize it. Um and it is possible to + + + align:start position:0% +uniformize it. Um and it is possible to +uniformize it. + + align:start position:0% +uniformize it. + + + align:start position:0% +uniformize it. +Okay. So let me scribe that. So um + + align:start position:0% +Okay. So let me scribe that. So um + + + align:start position:0% +Okay. So let me scribe that. So um +um + + align:start position:0% +um + + + align:start position:0% +um +can do some + + align:start position:0% +can do some + + + align:start position:0% +can do some +uniformizing + + align:start position:0% + + + + align:start position:0% + +so all tubes + + align:start position:0% +so all tubes + + + align:start position:0% +so all tubes +have the same number of balls. + + align:start position:0% + + + + align:start position:0% + +Okay, other questions or comments? + + align:start position:0% + + + + align:start position:0% + +Okay. Cool. + + align:start position:0% +Okay. Cool. + + + align:start position:0% +Okay. Cool. +All right. So, this little lema is very + + align:start position:0% +All right. So, this little lema is very + + + align:start position:0% +All right. So, this little lema is very +important. Um, for people who have some + + align:start position:0% +important. Um, for people who have some + + + align:start position:0% +important. Um, for people who have some +seen some other things in harmonic + + align:start position:0% +seen some other things in harmonic + + + align:start position:0% +seen some other things in harmonic +analysis, there's a submative lema + + align:start position:0% +analysis, there's a submative lema + + + align:start position:0% +analysis, there's a submative lema +that's sort of like this in decoupling + + align:start position:0% +that's sort of like this in decoupling + + + align:start position:0% +that's sort of like this in decoupling +theory and it's the beginning of what's + + align:start position:0% +theory and it's the beginning of what's + + + align:start position:0% +theory and it's the beginning of what's +special about decoupling. If those words + + align:start position:0% +special about decoupling. If those words + + + align:start position:0% +special about decoupling. If those words +don't mean anything to you, don't worry + + align:start position:0% +don't mean anything to you, don't worry + + + align:start position:0% +don't mean anything to you, don't worry +about it. Um so let me show you some uh + + align:start position:0% +about it. Um so let me show you some uh + + + align:start position:0% +about it. Um so let me show you some uh +corlary some applications of this lema + + align:start position:0% +corlary some applications of this lema + + + align:start position:0% +corlary some applications of this lema +and then we'll um and then we'll sort of + + align:start position:0% +and then we'll um and then we'll sort of + + + align:start position:0% +and then we'll um and then we'll sort of +go in earnest into using it to prove + + align:start position:0% +go in earnest into using it to prove + + + align:start position:0% +go in earnest into using it to prove +this theorem. + + align:start position:0% +this theorem. + + + align:start position:0% +this theorem. +All right. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +All + + align:start position:0% + + + + align:start position:0% + +right. So the first application is sort + + align:start position:0% +right. So the first application is sort + + + align:start position:0% +right. So the first application is sort +of tongue and cheek + + align:start position:0% +of tongue and cheek + + + align:start position:0% +of tongue and cheek +but uh also I I I think it's + + align:start position:0% +but uh also I I I think it's + + + align:start position:0% +but uh also I I I think it's +philosophically important. I'm going to + + align:start position:0% +philosophically important. I'm going to + + + align:start position:0% +philosophically important. I'm going to +call it so applications. + + align:start position:0% +call it so applications. + + + align:start position:0% +call it so applications. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +I'm gonna call it uh brute force proof + + align:start position:0% + + + + align:start position:0% + +of a theorem of theorem um of the the ad + + align:start position:0% +of a theorem of theorem um of the the ad + + + align:start position:0% +of a theorem of theorem um of the the ad +regular case. + + align:start position:0% +regular case. + + + align:start position:0% +regular case. +So here's how it goes. + + align:start position:0% +So here's how it goes. + + + align:start position:0% +So here's how it goes. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +so for some + + align:start position:0% +so for some + + + align:start position:0% +so for some +for some specific delta knot + + align:start position:0% +for some specific delta knot + + + align:start position:0% +for some specific delta knot +we check by brute force + + align:start position:0% + + + + align:start position:0% + +that r a d + + align:start position:0% +that r a d + + + align:start position:0% +that r a d +s delta kn is bounded by um the right + + align:start position:0% +s delta kn is bounded by um the right + + + align:start position:0% +s delta kn is bounded by um the right +hand side + + align:start position:0% +hand side + + + align:start position:0% +hand side +and we won't be able to get it perfectly + + align:start position:0% +and we won't be able to get it perfectly + + + align:start position:0% +and we won't be able to get it perfectly +but we could get something like + + align:start position:0% + + + + align:start position:0% + +Okay. So, how could you do this? Once + + align:start position:0% +Okay. So, how could you do this? Once + + + align:start position:0% +Okay. So, how could you do this? Once +you fix a particular delta knot, like + + align:start position:0% +you fix a particular delta knot, like + + + align:start position:0% +you fix a particular delta knot, like +one over a million, there are really + + align:start position:0% +one over a million, there are really + + + align:start position:0% +one over a million, there are really +only finitely many different ways you + + align:start position:0% +only finitely many different ways you + + + align:start position:0% +only finitely many different ways you +could arrange the delta balls. And there + + align:start position:0% +could arrange the delta balls. And there + + + align:start position:0% +could arrange the delta balls. And there +are really only finitely many ways you + + align:start position:0% +are really only finitely many ways you + + + align:start position:0% +are really only finitely many ways you +could put the tubes. So, there's a giant + + align:start position:0% +could put the tubes. So, there's a giant + + + align:start position:0% +could put the tubes. So, there's a giant +brute force calculation that you + + align:start position:0% +brute force calculation that you + + + align:start position:0% +brute force calculation that you +couldn't really do, but we could + + align:start position:0% +couldn't really do, but we could + + + align:start position:0% +couldn't really do, but we could +imagine. And you could just check this. + + align:start position:0% +imagine. And you could just check this. + + + align:start position:0% +imagine. And you could just check this. +Once you have this then you use the + + align:start position:0% +Once you have this then you use the + + + align:start position:0% +Once you have this then you use the +submultiplicative lema + + align:start position:0% + + + + align:start position:0% + +many times. + + align:start position:0% + + + + align:start position:0% + +Um and so you know when you used it once + + align:start position:0% +Um and so you know when you used it once + + + align:start position:0% +Um and so you know when you used it once +you would get ra s delta kn squared that + + align:start position:0% +you would get ra s delta kn squared that + + + align:start position:0% +you would get ra s delta kn squared that +would be bounded by right hand side + + align:start position:0% +would be bounded by right hand side + + + align:start position:0% +would be bounded by right hand side +times delta kn squar to the minus + + align:start position:0% +times delta kn squar to the minus + + + align:start position:0% +times delta kn squar to the minus +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +because the the right hand side is just + + align:start position:0% +because the the right hand side is just + + + align:start position:0% +because the the right hand side is just +a power delta kn. So it multiplies + + align:start position:0% +a power delta kn. So it multiplies + + + align:start position:0% +a power delta kn. So it multiplies +everything fits and you you keep going. + + align:start position:0% + + + + align:start position:0% + +Okay, so of course this so this brute + + align:start position:0% +Okay, so of course this so this brute + + + align:start position:0% +Okay, so of course this so this brute +force computation is so large that it's + + align:start position:0% +force computation is so large that it's + + + align:start position:0% +force computation is so large that it's +out of the question to do it even with a + + align:start position:0% +out of the question to do it even with a + + + align:start position:0% +out of the question to do it even with a +supercomputer etc. Um, nevertheless, it + + align:start position:0% +supercomputer etc. Um, nevertheless, it + + + align:start position:0% +supercomputer etc. Um, nevertheless, it +is worth noticing that this very + + align:start position:0% +is worth noticing that this very + + + align:start position:0% +is worth noticing that this very +difficult theorem has a one blackboard + + align:start position:0% +difficult theorem has a one blackboard + + + align:start position:0% +difficult theorem has a one blackboard +proof up to a brute force computation. + + align:start position:0% +proof up to a brute force computation. + + + align:start position:0% +proof up to a brute force computation. +Up to a finite computation. Most + + align:start position:0% +Up to a finite computation. Most + + + align:start position:0% +Up to a finite computation. Most +difficult theorems in math, it's not + + align:start position:0% +difficult theorems in math, it's not + + + align:start position:0% +difficult theorems in math, it's not +obvious how to reduce to a finite + + align:start position:0% +obvious how to reduce to a finite + + + align:start position:0% +obvious how to reduce to a finite +computation. I wouldn't say this is + + align:start position:0% +computation. I wouldn't say this is + + + align:start position:0% +computation. I wouldn't say this is +obvious either, but for most difficult + + align:start position:0% +obvious either, but for most difficult + + + align:start position:0% +obvious either, but for most difficult +theorems in math, there's not a + + align:start position:0% +theorems in math, there's not a + + + align:start position:0% +theorems in math, there's not a +half-page argument to reduce it to a + + align:start position:0% +half-page argument to reduce it to a + + + align:start position:0% +half-page argument to reduce it to a +finite computation. For this one, there + + align:start position:0% +finite computation. For this one, there + + + align:start position:0% +finite computation. For this one, there +is, but it shows that this is quite + + align:start position:0% +is, but it shows that this is quite + + + align:start position:0% +is, but it shows that this is quite +important. + + align:start position:0% + + + + align:start position:0% + +Okay, let me give another application. + + align:start position:0% +Okay, let me give another application. + + + align:start position:0% +Okay, let me give another application. +Um, second application is the general + + align:start position:0% +Um, second application is the general + + + align:start position:0% +Um, second application is the general +case + + align:start position:0% +case + + + align:start position:0% +case +general ad versus the projective ad. + + align:start position:0% + + + + align:start position:0% + +Um, okay. So, the course was called + + align:start position:0% +Um, okay. So, the course was called + + + align:start position:0% +Um, okay. So, the course was called +projection theory. Uh, and at the + + align:start position:0% +projection theory. Uh, and at the + + + align:start position:0% +projection theory. Uh, and at the +beginning we talked about problems about + + align:start position:0% +beginning we talked about problems about + + + align:start position:0% +beginning we talked about problems about +orthogonal projections. And this theorem + + align:start position:0% +orthogonal projections. And this theorem + + + align:start position:0% +orthogonal projections. And this theorem +is really more general. I guess I've + + align:start position:0% +is really more general. I guess I've + + + align:start position:0% +is really more general. I guess I've +erased the theorem. The theorem we're + + align:start position:0% +erased the theorem. The theorem we're + + + align:start position:0% +erased the theorem. The theorem we're +talking about today is more general than + + align:start position:0% +talking about today is more general than + + + align:start position:0% +talking about today is more general than +just orthogonal projections. Um, and if + + align:start position:0% +just orthogonal projections. Um, and if + + + align:start position:0% +just orthogonal projections. Um, and if +you had some orthogonal projections, the + + align:start position:0% +you had some orthogonal projections, the + + + align:start position:0% +you had some orthogonal projections, the +way you would get all these tubes is you + + align:start position:0% +way you would get all these tubes is you + + + align:start position:0% +way you would get all these tubes is you +would pick a direction from your + + align:start position:0% +would pick a direction from your + + + align:start position:0% +would pick a direction from your +direction set. And then you would get a + + align:start position:0% +direction set. And then you would get a + + + align:start position:0% +direction set. And then you would get a +bunch of tubes in that direction that + + align:start position:0% +bunch of tubes in that direction that + + + align:start position:0% +bunch of tubes in that direction that +cover your set. + + align:start position:0% +cover your set. + + + align:start position:0% +cover your set. +So um, so I make a definition. + + align:start position:0% +So um, so I make a definition. + + + align:start position:0% +So um, so I make a definition. +Let's say that ET is projective + + align:start position:0% + + + + align:start position:0% + +If + + align:start position:0% +If + + + align:start position:0% +If +for every X and E, + + align:start position:0% +for every X and E, + + + align:start position:0% +for every X and E, +the direction set of the tubes TX, let + + align:start position:0% +the direction set of the tubes TX, let + + + align:start position:0% +the direction set of the tubes TX, let +me put it this way, for every X1 and X2 + + align:start position:0% +me put it this way, for every X1 and X2 + + + align:start position:0% +me put it this way, for every X1 and X2 +and E, the direction of the tubes + + align:start position:0% +and E, the direction of the tubes + + + align:start position:0% +and E, the direction of the tubes +through X1 is the same as the direction + + align:start position:0% +through X1 is the same as the direction + + + align:start position:0% +through X1 is the same as the direction +of the tubes through X2. + + align:start position:0% +of the tubes through X2. + + + align:start position:0% +of the tubes through X2. +In other words, you have just one set of + + align:start position:0% +In other words, you have just one set of + + + align:start position:0% +In other words, you have just one set of +directions and TX is all the tubes + + align:start position:0% +directions and TX is all the tubes + + + align:start position:0% +directions and TX is all the tubes +through X in that set of directions. + + align:start position:0% +through X in that set of directions. + + + align:start position:0% +through X in that set of directions. +Okay, so if you think about the general + + align:start position:0% +Okay, so if you think about the general + + + align:start position:0% +Okay, so if you think about the general +the problem that we wrote down, this is + + align:start position:0% +the problem that we wrote down, this is + + + align:start position:0% +the problem that we wrote down, this is +a very special case. So it used to be at + + align:start position:0% +a very special case. So it used to be at + + + align:start position:0% +a very special case. So it used to be at +every point you picked your own + + align:start position:0% +every point you picked your own + + + align:start position:0% +every point you picked your own +independent set of tubes, but now + + align:start position:0% +independent set of tubes, but now + + + align:start position:0% +independent set of tubes, but now +there's an extra rule that that the + + align:start position:0% +there's an extra rule that that the + + + align:start position:0% +there's an extra rule that that the +directions have to be the same at each + + align:start position:0% +directions have to be the same at each + + + align:start position:0% +directions have to be the same at each +point. It's a very special case. + + align:start position:0% +point. It's a very special case. + + + align:start position:0% +point. It's a very special case. +Okay, so + + align:start position:0% +Okay, so + + + align:start position:0% +Okay, so +let's say RA a projection of delta is uh + + align:start position:0% +let's say RA a projection of delta is uh + + + align:start position:0% +let's say RA a projection of delta is uh +the maximum over the usual stuff. So ET + + align:start position:0% +the maximum over the usual stuff. So ET + + + align:start position:0% +the maximum over the usual stuff. So ET +obeys our hypothesis. Uh E is a regular + + align:start position:0% +obeys our hypothesis. Uh E is a regular + + + align:start position:0% +obeys our hypothesis. Uh E is a regular +but also ET is projective. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% + + + + align:start position:0% + +Cool. + + align:start position:0% + + + + align:start position:0% + +So um + + align:start position:0% +So um + + + align:start position:0% +So um +in general that you know that we're + + align:start position:0% +in general that you know that we're + + + align:start position:0% +in general that you know that we're +taking a maximum and this is a + + align:start position:0% +taking a maximum and this is a + + + align:start position:0% +taking a maximum and this is a +restricted maximum. So we clearly have + + align:start position:0% +restricted maximum. So we clearly have + + + align:start position:0% +restricted maximum. So we clearly have +that ra a projective + + align:start position:0% +that ra a projective + + + align:start position:0% +that ra a projective +is smaller than rather + + align:start position:0% +is smaller than rather + + + align:start position:0% +is smaller than rather +more cases + + align:start position:0% +more cases + + + align:start position:0% +more cases +but it turns out that they're basically + + align:start position:0% +but it turns out that they're basically + + + align:start position:0% +but it turns out that they're basically +equal to each other. So let's make that + + align:start position:0% +equal to each other. So let's make that + + + align:start position:0% +equal to each other. So let's make that +a lema. + + align:start position:0% +a lema. + + + align:start position:0% +a lema. +So r a d of delta is less than here + + align:start position:0% +So r a d of delta is less than here + + + align:start position:0% +So r a d of delta is less than here +there are some fudge factors so I'll + + align:start position:0% +there are some fudge factors so I'll + + + align:start position:0% +there are some fudge factors so I'll +write something like this c epsilon + + align:start position:0% +write something like this c epsilon + + + align:start position:0% +write something like this c epsilon +delta to the minus epsilon + + align:start position:0% + + + + align:start position:0% + +actually let me I don't quite say that + + align:start position:0% +actually let me I don't quite say that + + + align:start position:0% +actually let me I don't quite say that +that's true but + + align:start position:0% +that's true but + + + align:start position:0% +that's true but +let me just say something uh okay so + + align:start position:0% +let me just say something uh okay so + + + align:start position:0% +let me just say something uh okay so +here so here's a cool observation based + + align:start position:0% +here so here's a cool observation based + + + align:start position:0% +here so here's a cool observation based +on that diagram and that proof + + align:start position:0% +on that diagram and that proof + + + align:start position:0% +on that diagram and that proof +so notice + + align:start position:0% +so notice + + + align:start position:0% +so notice +that in the uh sub multip applicative + + align:start position:0% +that in the uh sub multip applicative + + + align:start position:0% +that in the uh sub multip applicative +lama. + + align:start position:0% + + + + align:start position:0% + +If um delta 1 equals delta 2= square + + align:start position:0% +If um delta 1 equals delta 2= square + + + align:start position:0% +If um delta 1 equals delta 2= square +root of delta, + + align:start position:0% +root of delta, + + + align:start position:0% +root of delta, +then + + align:start position:0% +then + + + align:start position:0% +then +the + + align:start position:0% +the + + + align:start position:0% +the +inner uh the the small ball problems are + + align:start position:0% +inner uh the the small ball problems are + + + align:start position:0% +inner uh the the small ball problems are +all projective. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So in this in this problem we sort of we + + align:start position:0% +So in this in this problem we sort of we + + + align:start position:0% +So in this in this problem we sort of we +have a a delta scale + + align:start position:0% +have a a delta scale + + + align:start position:0% +have a a delta scale +>> fenberg problem and we broke it up into + + align:start position:0% +>> fenberg problem and we broke it up into + + + align:start position:0% +>> fenberg problem and we broke it up into +two pieces a coarse piece at the large + + align:start position:0% +two pieces a coarse piece at the large + + + align:start position:0% +two pieces a coarse piece at the large +scale and a piece a small piece inside + + align:start position:0% +scale and a piece a small piece inside + + + align:start position:0% +scale and a piece a small piece inside +each small ball. Okay so I claim that + + align:start position:0% +each small ball. Okay so I claim that + + + align:start position:0% +each small ball. Okay so I claim that +this piece inside the small ball is + + align:start position:0% +this piece inside the small ball is + + + align:start position:0% +this piece inside the small ball is +projective. + + align:start position:0% +projective. + + + align:start position:0% +projective. +Why is it? Well, + + align:start position:0% + + + + align:start position:0% + +so pick one of these points and I'm + + align:start position:0% +so pick one of these points and I'm + + + align:start position:0% +so pick one of these points and I'm +going to look at the directions of the + + align:start position:0% +going to look at the directions of the + + + align:start position:0% +going to look at the directions of the +red tubes going through this point. + + align:start position:0% +red tubes going through this point. + + + align:start position:0% +red tubes going through this point. +Um, now I'm working in this small ball, + + align:start position:0% +Um, now I'm working in this small ball, + + + align:start position:0% +Um, now I'm working in this small ball, +so I can only distinguish them up to an + + align:start position:0% +so I can only distinguish them up to an + + + align:start position:0% +so I can only distinguish them up to an +angle of square root of delta. + + align:start position:0% +angle of square root of delta. + + + align:start position:0% +angle of square root of delta. +So what directions will they be? They'll + + align:start position:0% +So what directions will they be? They'll + + + align:start position:0% +So what directions will they be? They'll +be the directions of these orange tubes + + align:start position:0% +be the directions of these orange tubes + + + align:start position:0% +be the directions of these orange tubes +going out through here. + + align:start position:0% +going out through here. + + + align:start position:0% +going out through here. +So, so there there could well be two + + align:start position:0% +So, so there there could well be two + + + align:start position:0% +So, so there there could well be two +long red tubes going through here in the + + align:start position:0% +long red tubes going through here in the + + + align:start position:0% +long red tubes going through here in the +that are in the same orange tube, but + + align:start position:0% +that are in the same orange tube, but + + + align:start position:0% +that are in the same orange tube, but +inside of this small ball, they'll just + + align:start position:0% +inside of this small ball, they'll just + + + align:start position:0% +inside of this small ball, they'll just +be on top of each other. I won't see any + + align:start position:0% +be on top of each other. I won't see any + + + align:start position:0% +be on top of each other. I won't see any +difference between them. + + align:start position:0% +difference between them. + + + align:start position:0% +difference between them. +So, the directions that I'll see within + + align:start position:0% +So, the directions that I'll see within + + + align:start position:0% +So, the directions that I'll see within +the small ball, they just correspond to + + align:start position:0% +the small ball, they just correspond to + + + align:start position:0% +the small ball, they just correspond to +these orange tubes. + + align:start position:0% +these orange tubes. + + + align:start position:0% +these orange tubes. +And if I look at different guys inside + + align:start position:0% +And if I look at different guys inside + + + align:start position:0% +And if I look at different guys inside +the small ball, I have the same set of + + align:start position:0% +the small ball, I have the same set of + + + align:start position:0% +the small ball, I have the same set of +orange tubes. + + align:start position:0% + + + + align:start position:0% + +Okay, so that gives me an inequality + + align:start position:0% + + + + align:start position:0% + +r a delta is bounded by + + align:start position:0% +r a delta is bounded by + + + align:start position:0% +r a delta is bounded by +R a D delta to the half times R A D + + align:start position:0% +R a D delta to the half times R A D + + + align:start position:0% +R a D delta to the half times R A D +projective + + align:start position:0% +projective + + + align:start position:0% +projective +delta to the 12. + + align:start position:0% +delta to the 12. + + + align:start position:0% +delta to the 12. +Yeah, + + align:start position:0% +Yeah, + + + align:start position:0% +Yeah, +>> I thought that you were writing + + align:start position:0% +>> I thought that you were writing + + + align:start position:0% +>> I thought that you were writing +projective, + + align:start position:0% +projective, + + + align:start position:0% +projective, +>> right? Only the inner one is projective. + + align:start position:0% +>> right? Only the inner one is projective. + + + align:start position:0% +>> right? Only the inner one is projective. +The outer one is arbitrary. + + align:start position:0% + + + + align:start position:0% + +However, we can repeat this. + + align:start position:0% +However, we can repeat this. + + + align:start position:0% +However, we can repeat this. +So now that's bounded by RA a delta to + + align:start position:0% +So now that's bounded by RA a delta to + + + align:start position:0% +So now that's bounded by RA a delta to +the quarter R A projective delta to the + + align:start position:0% +the quarter R A projective delta to the + + + align:start position:0% +the quarter R A projective delta to the +quarter + + align:start position:0% +quarter + + + align:start position:0% +quarter +R A projective + + align:start position:0% +R A projective + + + align:start position:0% +R A projective +delta to the half. + + align:start position:0% + + + + align:start position:0% + +And now you can keep going. + + align:start position:0% +And now you can keep going. + + + align:start position:0% +And now you can keep going. +Okay, so you do this many times. + + align:start position:0% +Okay, so you do this many times. + + + align:start position:0% +Okay, so you do this many times. +There'll be a T appendix left here that + + align:start position:0% +There'll be a T appendix left here that + + + align:start position:0% +There'll be a T appendix left here that +is still has no projective on it, but + + align:start position:0% +is still has no projective on it, but + + + align:start position:0% +is still has no projective on it, but +it'll be very minor. And the rest of + + align:start position:0% +it'll be very minor. And the rest of + + + align:start position:0% +it'll be very minor. And the rest of +them all have projective. And so the + + align:start position:0% +them all have projective. And so the + + + align:start position:0% +them all have projective. And so the +conclusion is that to prove the theorem, + + align:start position:0% + + + + align:start position:0% + +it suffices to check the projective + + align:start position:0% +it suffices to check the projective + + + align:start position:0% +it suffices to check the projective +case. + + align:start position:0% + + + + align:start position:0% + +So that's a cute application of being + + align:start position:0% +So that's a cute application of being + + + align:start position:0% +So that's a cute application of being +submitted. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So those are a couple of cute + + align:start position:0% +So those are a couple of cute + + + align:start position:0% +So those are a couple of cute +applications of this lama. Yeah. + + align:start position:0% +applications of this lama. Yeah. + + + align:start position:0% +applications of this lama. Yeah. +>> Is that like extra r that kind of went + + align:start position:0% +>> Is that like extra r that kind of went + + + align:start position:0% +>> Is that like extra r that kind of went +over epsilon + + align:start position:0% +over epsilon + + + align:start position:0% +over epsilon +uh kind of where the delta epsilon kind + + align:start position:0% +uh kind of where the delta epsilon kind + + + align:start position:0% +uh kind of where the delta epsilon kind +of error term final or is there as well? + + align:start position:0% +of error term final or is there as well? + + + align:start position:0% +of error term final or is there as well? +>> There are several places where we might + + align:start position:0% +>> There are several places where we might + + + align:start position:0% +>> There are several places where we might +incur a delta to the epsilon in the + + align:start position:0% +incur a delta to the epsilon in the + + + align:start position:0% +incur a delta to the epsilon in the +final thing and this is one of them. + + align:start position:0% +final thing and this is one of them. + + + align:start position:0% +final thing and this is one of them. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. Um, + + align:start position:0% +Okay. Um, + + + align:start position:0% +Okay. Um, +so let's say something big picture about + + align:start position:0% +so let's say something big picture about + + + align:start position:0% +so let's say something big picture about +trying to prove this theorem. + + align:start position:0% +trying to prove this theorem. + + + align:start position:0% +trying to prove this theorem. +So we were saying yesterday that for a + + align:start position:0% +So we were saying yesterday that for a + + + align:start position:0% +So we were saying yesterday that for a +while in this subject there were only + + align:start position:0% +while in this subject there were only + + + align:start position:0% +while in this subject there were only +kind of there were only epsilon + + align:start position:0% +kind of there were only epsilon + + + align:start position:0% +kind of there were only epsilon +improvements on some classical things. + + align:start position:0% +improvements on some classical things. + + + align:start position:0% +improvements on some classical things. +And what was very striking to me is to + + align:start position:0% +And what was very striking to me is to + + + align:start position:0% +And what was very striking to me is to +go from just making epsilon improvements + + align:start position:0% +go from just making epsilon improvements + + + align:start position:0% +go from just making epsilon improvements +to go to making to to proving the sharp + + align:start position:0% +to go to making to to proving the sharp + + + align:start position:0% +to go to making to to proving the sharp +theorem. + + align:start position:0% +theorem. + + + align:start position:0% +theorem. +And while Pablush Murkin was visiting, I + + align:start position:0% +And while Pablush Murkin was visiting, I + + + align:start position:0% +And while Pablush Murkin was visiting, I +talked with him a lot about all this + + align:start position:0% +talked with him a lot about all this + + + align:start position:0% +talked with him a lot about all this +stuff. And he said to me something one + + align:start position:0% +stuff. And he said to me something one + + + align:start position:0% +stuff. And he said to me something one +day that really stuck with me. He said + + align:start position:0% +day that really stuck with me. He said + + + align:start position:0% +day that really stuck with me. He said +sort of philosophically. + + align:start position:0% +sort of philosophically. + + + align:start position:0% +sort of philosophically. +Um + + align:start position:0% + + + + align:start position:0% + +that here, yeah, here's how I would like + + align:start position:0% +that here, yeah, here's how I would like + + + align:start position:0% +that here, yeah, here's how I would like +to put it. Um + + align:start position:0% +to put it. Um + + + align:start position:0% +to put it. Um +that in order to prove this theorem, + + align:start position:0% +that in order to prove this theorem, + + + align:start position:0% +that in order to prove this theorem, +what we need to do is make an epsilon + + align:start position:0% +what we need to do is make an epsilon + + + align:start position:0% +what we need to do is make an epsilon +improvement on the submicative lema. + + align:start position:0% +improvement on the submicative lema. + + + align:start position:0% +improvement on the submicative lema. +So let me write that down because I + + align:start position:0% +So let me write that down because I + + + align:start position:0% +So let me write that down because I +think it's worth taking with you out of + + align:start position:0% +think it's worth taking with you out of + + + align:start position:0% +think it's worth taking with you out of +this class. + + align:start position:0% +this class. + + + align:start position:0% +this class. +So + + align:start position:0% +So + + + align:start position:0% +So +philosophy + + align:start position:0% + + + + align:start position:0% + +to prove the theorem + + align:start position:0% +to prove the theorem + + + align:start position:0% +to prove the theorem +what we need + + align:start position:0% +what we need + + + align:start position:0% +what we need +an epsilon improvement + + align:start position:0% +an epsilon improvement + + + align:start position:0% +an epsilon improvement +on the sub multiplicative length. + + align:start position:0% + + + + align:start position:0% + +Okay. So in other words, we'd like to + + align:start position:0% +Okay. So in other words, we'd like to + + + align:start position:0% +Okay. So in other words, we'd like to +say either + + align:start position:0% +say either + + + align:start position:0% +say either +one possibility is that ra a d square + + align:start position:0% +one possibility is that ra a d square + + + align:start position:0% +one possibility is that ra a d square +root of delta is already obeys the + + align:start position:0% +root of delta is already obeys the + + + align:start position:0% +root of delta is already obeys the +bound. + + align:start position:0% + + + + align:start position:0% + +Okay. Well then we're happy and you know + + align:start position:0% +Okay. Well then we're happy and you know + + + align:start position:0% +Okay. Well then we're happy and you know +by by the sub multiplicative lema our + + align:start position:0% +by by the sub multiplicative lema our + + + align:start position:0% +by by the sub multiplicative lema our +ide of delta also will obey the bound. + + align:start position:0% +ide of delta also will obey the bound. + + + align:start position:0% +ide of delta also will obey the bound. +So we'll be happy + + align:start position:0% +So we'll be happy + + + align:start position:0% +So we'll be happy +or + + align:start position:0% +or + + + align:start position:0% +or +we have so I'll write down the um sub + + align:start position:0% +we have so I'll write down the um sub + + + align:start position:0% +we have so I'll write down the um sub +multiplicative lema. + + align:start position:0% + + + + align:start position:0% + +So that's the sub multiplicative lema + + align:start position:0% +So that's the sub multiplicative lema + + + align:start position:0% +So that's the sub multiplicative lema +but or we have not not this lema but a + + align:start position:0% +but or we have not not this lema but a + + + align:start position:0% +but or we have not not this lema but a +little tiny improvement on it. + + align:start position:0% + + + + align:start position:0% + +Okay, so in this case of course we're + + align:start position:0% +Okay, so in this case of course we're + + + align:start position:0% +Okay, so in this case of course we're +happy and in this case we can iterate + + align:start position:0% +happy and in this case we can iterate + + + align:start position:0% +happy and in this case we can iterate +and so you can think of ra of delta as + + align:start position:0% +and so you can think of ra of delta as + + + align:start position:0% +and so you can think of ra of delta as +being some power of delta + + align:start position:0% +being some power of delta + + + align:start position:0% +being some power of delta +and then every time we do this that + + align:start position:0% +and then every time we do this that + + + align:start position:0% +and then every time we do this that +power goes down + + align:start position:0% +power goes down + + + align:start position:0% +power goes down +uh or some negative power of delta. + + align:start position:0% +uh or some negative power of delta. + + + align:start position:0% +uh or some negative power of delta. +Every time we do this, that power is + + align:start position:0% +Every time we do this, that power is + + + align:start position:0% +Every time we do this, that power is +going to go down. Um and um uh and so + + align:start position:0% +going to go down. Um and um uh and so + + + align:start position:0% +going to go down. Um and um uh and so +it'll keep going down until we get into + + align:start position:0% +it'll keep going down until we get into + + + align:start position:0% +it'll keep going down until we get into +this case and we're happy. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% +So + + + align:start position:0% +So +so let's illustrate that. So if say we + + align:start position:0% +so let's illustrate that. So if say we + + + align:start position:0% +so let's illustrate that. So if say we +have ra a delta + + align:start position:0% +have ra a delta + + + align:start position:0% +have ra a delta +um let me write it this way be easier as + + align:start position:0% +um let me write it this way be easier as + + + align:start position:0% +um let me write it this way be easier as +delta to the minus gamma then we'd have + + align:start position:0% +delta to the minus gamma then we'd have + + + align:start position:0% +delta to the minus gamma then we'd have +ra a d of delta squared + + align:start position:0% +ra a d of delta squared + + + align:start position:0% +ra a d of delta squared +would be bounded by um so this would + + align:start position:0% +would be bounded by um so this would + + + align:start position:0% +would be bounded by um so this would +give us delta to the minus 2 gamma but + + align:start position:0% +give us delta to the minus 2 gamma but + + + align:start position:0% +give us delta to the minus 2 gamma but +plus epsilon + + align:start position:0% + + + + align:start position:0% + +Then we would do this again. + + align:start position:0% +Then we would do this again. + + + align:start position:0% +Then we would do this again. +RA a D delta 4th would be bounded by + + align:start position:0% +RA a D delta 4th would be bounded by + + + align:start position:0% +RA a D delta 4th would be bounded by +delta 4 to the minus gamma plus epsilon + + align:start position:0% +delta 4 to the minus gamma plus epsilon + + + align:start position:0% +delta 4 to the minus gamma plus epsilon +plus epsilon. We keep going and this + + align:start position:0% +plus epsilon. We keep going and this + + + align:start position:0% +plus epsilon. We keep going and this +exponent keeps getting better and better + + align:start position:0% +exponent keeps getting better and better + + + align:start position:0% +exponent keeps getting better and better +until we can't make an epsilon + + align:start position:0% +until we can't make an epsilon + + + align:start position:0% +until we can't make an epsilon +improvement anymore. So if we have this + + align:start position:0% +improvement anymore. So if we have this + + + align:start position:0% +improvement anymore. So if we have this +dichotomy then we can get um the + + align:start position:0% +dichotomy then we can get um the + + + align:start position:0% +dichotomy then we can get um the +theorem. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Cool. + + align:start position:0% +Cool. + + + align:start position:0% +Cool. +Um + + align:start position:0% + + + + align:start position:0% + +all right. So so then you might reflect + + align:start position:0% +all right. So so then you might reflect + + + align:start position:0% +all right. So so then you might reflect +well you know why is it easier to make + + align:start position:0% +well you know why is it easier to make + + + align:start position:0% +well you know why is it easier to make +an epsilon improvement kind of theorem + + align:start position:0% +an epsilon improvement kind of theorem + + + align:start position:0% +an epsilon improvement kind of theorem +than it is to uh you know prove a really + + align:start position:0% +than it is to uh you know prove a really + + + align:start position:0% +than it is to uh you know prove a really +sharp bound straight out. Well, there's + + align:start position:0% +sharp bound straight out. Well, there's + + + align:start position:0% +sharp bound straight out. Well, there's +a thought process for that. If we have + + align:start position:0% +a thought process for that. If we have + + + align:start position:0% +a thought process for that. If we have +we already have a result and then we + + align:start position:0% +we already have a result and then we + + + align:start position:0% +we already have a result and then we +want to make an epsilon improvement, + + align:start position:0% +want to make an epsilon improvement, + + + align:start position:0% +want to make an epsilon improvement, +then we say to ourselves, you know, what + + align:start position:0% +then we say to ourselves, you know, what + + + align:start position:0% +then we say to ourselves, you know, what +would it look like if the result we have + + align:start position:0% +would it look like if the result we have + + + align:start position:0% +would it look like if the result we have +is sharp + + align:start position:0% +is sharp + + + align:start position:0% +is sharp +and maybe there's a lot of specific + + align:start position:0% +and maybe there's a lot of specific + + + align:start position:0% +and maybe there's a lot of specific +things that have to happen for the + + align:start position:0% +things that have to happen for the + + + align:start position:0% +things that have to happen for the +result we have to be sharp. So, we get a + + align:start position:0% +result we have to be sharp. So, we get a + + + align:start position:0% +result we have to be sharp. So, we get a +lot of structure and then we have then + + align:start position:0% +lot of structure and then we have then + + + align:start position:0% +lot of structure and then we have then +we have to get a contradiction and that + + align:start position:0% +we have to get a contradiction and that + + + align:start position:0% +we have to get a contradiction and that +shows you can do just a little bit + + align:start position:0% +shows you can do just a little bit + + + align:start position:0% +shows you can do just a little bit +better. That's why an epsilon + + align:start position:0% +better. That's why an epsilon + + + align:start position:0% +better. That's why an epsilon +improvement result is is easier than um + + align:start position:0% +improvement result is is easier than um + + + align:start position:0% +improvement result is is easier than um +than just getting a a great balance + + align:start position:0% +than just getting a a great balance + + + align:start position:0% +than just getting a a great balance +straight away. And you know and when we + + align:start position:0% +straight away. And you know and when we + + + align:start position:0% +straight away. And you know and when we +so you know if if we go back to Bans's + + align:start position:0% +so you know if if we go back to Bans's + + + align:start position:0% +so you know if if we go back to Bans's +projection theorem and we tried to make + + align:start position:0% +projection theorem and we tried to make + + + align:start position:0% +projection theorem and we tried to make +you know epsilon improvement in a in a + + align:start position:0% +you know epsilon improvement in a in a + + + align:start position:0% +you know epsilon improvement in a in a +projection theorem well we we didn't say + + align:start position:0% +projection theorem well we we didn't say + + + align:start position:0% +projection theorem well we we didn't say +this at the time but it might have been + + align:start position:0% +this at the time but it might have been + + + align:start position:0% +this at the time but it might have been +good to say you know what would it be + + align:start position:0% +good to say you know what would it be + + + align:start position:0% +good to say you know what would it be +like what would it mean if the bound we + + align:start position:0% +like what would it mean if the bound we + + + align:start position:0% +like what would it mean if the bound we +have so far is sharp would mean we have + + align:start position:0% +have so far is sharp would mean we have + + + align:start position:0% +have so far is sharp would mean we have +this structure and that structure and + + align:start position:0% +this structure and that structure and + + + align:start position:0% +this structure and that structure and +eventually we have this subset that is + + align:start position:0% +eventually we have this subset that is + + + align:start position:0% +eventually we have this subset that is +almost closed under addition and almost + + align:start position:0% +almost closed under addition and almost + + + align:start position:0% +almost closed under addition and almost +closed under multiplication anda d + + align:start position:0% + + + + align:start position:0% + +Okay, so the idea is we are going to try + + align:start position:0% +Okay, so the idea is we are going to try + + + align:start position:0% +Okay, so the idea is we are going to try +to do the same thing. We're going to + + align:start position:0% +to do the same thing. We're going to + + + align:start position:0% +to do the same thing. We're going to +think about what would it mean if the + + align:start position:0% +think about what would it mean if the + + + align:start position:0% +think about what would it mean if the +sub multiplicative lema was sharp and + + align:start position:0% +sub multiplicative lema was sharp and + + + align:start position:0% +sub multiplicative lema was sharp and +we're going to see that it just means + + align:start position:0% +we're going to see that it just means + + + align:start position:0% +we're going to see that it just means +the set has to have a lot of structure + + align:start position:0% +the set has to have a lot of structure + + + align:start position:0% +the set has to have a lot of structure +and eventually we'll get down maybe not + + align:start position:0% +and eventually we'll get down maybe not + + + align:start position:0% +and eventually we'll get down maybe not +today but eventually + + align:start position:0% +today but eventually + + + align:start position:0% +today but eventually +orin and smirkin uh got down to to the + + align:start position:0% +orin and smirkin uh got down to to the + + + align:start position:0% +orin and smirkin uh got down to to the +structures got down to the banan + + align:start position:0% +structures got down to the banan + + + align:start position:0% +structures got down to the banan +projection theorem or um and got a + + align:start position:0% +projection theorem or um and got a + + + align:start position:0% +projection theorem or um and got a +contradiction + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's talk about what would it mean + + align:start position:0% +so let's talk about what would it mean + + + align:start position:0% +so let's talk about what would it mean +if the sub multiplic Licative llama is + + align:start position:0% +if the sub multiplic Licative llama is + + + align:start position:0% +if the sub multiplic Licative llama is +sharp. + + align:start position:0% + + + + align:start position:0% + +Okay. So let me draw a couple pictures + + align:start position:0% +Okay. So let me draw a couple pictures + + + align:start position:0% +Okay. So let me draw a couple pictures +for you. And one of the pictures it + + align:start position:0% +for you. And one of the pictures it + + + align:start position:0% +for you. And one of the pictures it +corresponds to the sub multiplicative + + align:start position:0% +corresponds to the sub multiplicative + + + align:start position:0% +corresponds to the sub multiplicative +lamina is sharp and in the other one it + + align:start position:0% +lamina is sharp and in the other one it + + + align:start position:0% +lamina is sharp and in the other one it +it it's not. + + align:start position:0% +it it's not. + + + align:start position:0% +it it's not. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So, + + align:start position:0% + + + + align:start position:0% + +so we'll have some fat balls in a fat + + align:start position:0% +so we'll have some fat balls in a fat + + + align:start position:0% +so we'll have some fat balls in a fat +tube. + + align:start position:0% + + + + align:start position:0% + +And + + align:start position:0% +And + + + align:start position:0% +And +then in each fat tube, in each fat ball, + + align:start position:0% +then in each fat tube, in each fat ball, + + + align:start position:0% +then in each fat tube, in each fat ball, +we have some little balls. + + align:start position:0% +we have some little balls. + + + align:start position:0% +we have some little balls. +And the little balls are in little + + align:start position:0% +And the little balls are in little + + + align:start position:0% +And the little balls are in little +tubes. + + align:start position:0% + + + + align:start position:0% + +So there's your typical little tube and + + align:start position:0% +So there's your typical little tube and + + + align:start position:0% +So there's your typical little tube and +okay in each of these balls there are + + align:start position:0% +okay in each of these balls there are + + + align:start position:0% +okay in each of these balls there are +some each of these back balls there are + + align:start position:0% +some each of these back balls there are + + + align:start position:0% +some each of these back balls there are +some little balls. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So in the scenario in this picture would + + align:start position:0% +So in the scenario in this picture would + + + align:start position:0% +So in the scenario in this picture would +the sub multiplicative lema be sharp or + + align:start position:0% +the sub multiplicative lema be sharp or + + + align:start position:0% +the sub multiplicative lema be sharp or +not sharp? + + align:start position:0% +not sharp? + + + align:start position:0% +not sharp? +Stand next to the picture + + align:start position:0% +Stand next to the picture + + + align:start position:0% +Stand next to the picture +in this picture. Would the sub + + align:start position:0% +in this picture. Would the sub + + + align:start position:0% +in this picture. Would the sub +multiplicative lema be sharp or not + + align:start position:0% +multiplicative lema be sharp or not + + + align:start position:0% +multiplicative lema be sharp or not +sharp? + + align:start position:0% + + + + align:start position:0% + +I don't think it's sharp because there's + + align:start position:0% +I don't think it's sharp because there's + + + align:start position:0% +I don't think it's sharp because there's +just one tube for the like coarser + + align:start position:0% +just one tube for the like coarser + + + align:start position:0% +just one tube for the like coarser +scale. that could be consist of several + + align:start position:0% +scale. that could be consist of several + + + align:start position:0% +scale. that could be consist of several +tubes for the fine scale. + + align:start position:0% +tubes for the fine scale. + + + align:start position:0% +tubes for the fine scale. +>> Um, okay. So, let me clarify what this + + align:start position:0% +>> Um, okay. So, let me clarify what this + + + align:start position:0% +>> Um, okay. So, let me clarify what this +is a picture of. + + align:start position:0% +is a picture of. + + + align:start position:0% +is a picture of. +So, so there are many coarse scale + + align:start position:0% +So, so there are many coarse scale + + + align:start position:0% +So, so there are many coarse scale +tubes, but I just drew one of them. And + + align:start position:0% +tubes, but I just drew one of them. And + + + align:start position:0% +tubes, but I just drew one of them. And +I'm just drawing what's happening inside + + align:start position:0% +I'm just drawing what's happening inside + + + align:start position:0% +I'm just drawing what's happening inside +of one of them. So, inside of that one + + align:start position:0% +of one of them. So, inside of that one + + + align:start position:0% +of one of them. So, inside of that one +coarse tube, this is what we see based + + align:start position:0% +coarse tube, this is what we see based + + + align:start position:0% +coarse tube, this is what we see based +on this is the + + align:start position:0% +on this is the + + + align:start position:0% +on this is the +>> So, there's only one fine scale tube. Um + + align:start position:0% +>> So, there's only one fine scale tube. Um + + + align:start position:0% +>> So, there's only one fine scale tube. Um +there could be more fine scale tubes but + + align:start position:0% +there could be more fine scale tubes but + + + align:start position:0% +there could be more fine scale tubes but +this is a typical one. Yes, there are + + align:start position:0% +this is a typical one. Yes, there are + + + align:start position:0% +this is a typical one. Yes, there are +many orange tubes and many red tubes but + + align:start position:0% +many orange tubes and many red tubes but + + + align:start position:0% +many orange tubes and many red tubes but +I'm drawing uh only one of each to + + align:start position:0% +I'm drawing uh only one of each to + + + align:start position:0% +I'm drawing uh only one of each to +direct your to focus our attention. + + align:start position:0% + + + + align:start position:0% + +Okay, so let's review for a second the + + align:start position:0% +Okay, so let's review for a second the + + + align:start position:0% +Okay, so let's review for a second the +proof of the sub multiplicative lama uh + + align:start position:0% +proof of the sub multiplicative lama uh + + + align:start position:0% +proof of the sub multiplicative lama uh +because it's really important and maybe + + align:start position:0% +because it's really important and maybe + + + align:start position:0% +because it's really important and maybe +it'll go in a little deeper and then + + align:start position:0% +it'll go in a little deeper and then + + + align:start position:0% +it'll go in a little deeper and then +I'll try this again. Okay, so our goal + + align:start position:0% +I'll try this again. Okay, so our goal + + + align:start position:0% +I'll try this again. Okay, so our goal +is to estimate ra of delta, which is the + + align:start position:0% +is to estimate ra of delta, which is the + + + align:start position:0% +is to estimate ra of delta, which is the +number of delta balls per delta tube. + + align:start position:0% +number of delta balls per delta tube. + + + align:start position:0% +number of delta balls per delta tube. +So I picked a delta tube like this red + + align:start position:0% +So I picked a delta tube like this red + + + align:start position:0% +So I picked a delta tube like this red +one here. I I have to estimate the + + align:start position:0% +one here. I I have to estimate the + + + align:start position:0% +one here. I I have to estimate the +number of delta balls in it. First I + + align:start position:0% +number of delta balls in it. First I + + + align:start position:0% +number of delta balls in it. First I +estimate the number of fat balls that it + + align:start position:0% +estimate the number of fat balls that it + + + align:start position:0% +estimate the number of fat balls that it +intersects + + align:start position:0% +intersects + + + align:start position:0% +intersects +and then I multiply that by the number + + align:start position:0% +and then I multiply that by the number + + + align:start position:0% +and then I multiply that by the number +of delta balls that it intersects within + + align:start position:0% +of delta balls that it intersects within + + + align:start position:0% +of delta balls that it intersects within +each fat ball. And that was my bat. + + align:start position:0% +each fat ball. And that was my bat. + + + align:start position:0% +each fat ball. And that was my bat. +And that each one of those things I + + align:start position:0% +And that each one of those things I + + + align:start position:0% +And that each one of those things I +bounded sort of by induction and I got + + align:start position:0% +bounded sort of by induction and I got + + + align:start position:0% +bounded sort of by induction and I got +those two members. All right. So + + align:start position:0% +those two members. All right. So + + + align:start position:0% +those two members. All right. So +if I take a particular fat tube and + + align:start position:0% +if I take a particular fat tube and + + + align:start position:0% +if I take a particular fat tube and +inside of it a particular thin tube and + + align:start position:0% +inside of it a particular thin tube and + + + align:start position:0% +inside of it a particular thin tube and +I see this would that argument be sharp? + + align:start position:0% + + + + align:start position:0% + +Right. Okay. So so the suggestion is + + align:start position:0% +Right. Okay. So so the suggestion is + + + align:start position:0% +Right. Okay. So so the suggestion is +that this is not sharp because uh inside + + align:start position:0% +that this is not sharp because uh inside + + + align:start position:0% +that this is not sharp because uh inside +of this red tube most of the fat balls + + align:start position:0% +of this red tube most of the fat balls + + + align:start position:0% +of this red tube most of the fat balls +are contributed nothing. + + align:start position:0% +are contributed nothing. + + + align:start position:0% +are contributed nothing. +And only this one fat ball is + + align:start position:0% +And only this one fat ball is + + + align:start position:0% +And only this one fat ball is +contributing. + + align:start position:0% + + + + align:start position:0% + +And it would be sharp if the number of + + align:start position:0% +And it would be sharp if the number of + + + align:start position:0% +And it would be sharp if the number of +delta balls in the fat ball was the + + align:start position:0% +delta balls in the fat ball was the + + + align:start position:0% +delta balls in the fat ball was the +number of sorry the number of delta + + align:start position:0% +number of sorry the number of delta + + + align:start position:0% +number of sorry the number of delta +balls in the delta tube was the number + + align:start position:0% +balls in the delta tube was the number + + + align:start position:0% +balls in the delta tube was the number +of fat balls times the number of delta + + align:start position:0% +of fat balls times the number of delta + + + align:start position:0% +of fat balls times the number of delta +balls in one of them. So let me show. So + + align:start position:0% +balls in one of them. So let me show. So + + + align:start position:0% +balls in one of them. So let me show. So +this is not sharp. And let me draw the + + align:start position:0% +this is not sharp. And let me draw the + + + align:start position:0% +this is not sharp. And let me draw the +one that's sharp. You'll see the + + align:start position:0% +one that's sharp. You'll see the + + + align:start position:0% +one that's sharp. You'll see the +difference. This is not sharp. + + align:start position:0% + + + + align:start position:0% + +Delta tube + + align:start position:0% +Delta tube + + + align:start position:0% +Delta tube +should look like this, + + align:start position:0% + + + + align:start position:0% + +right? So the delta tube should + + align:start position:0% +right? So the delta tube should + + + align:start position:0% +right? So the delta tube should +intersect a bunch of fat balls. It + + align:start position:0% +intersect a bunch of fat balls. It + + + align:start position:0% +intersect a bunch of fat balls. It +should intersect that many fat balls as + + align:start position:0% +should intersect that many fat balls as + + + align:start position:0% +should intersect that many fat balls as +many as possible. And inside each one of + + align:start position:0% +many as possible. And inside each one of + + + align:start position:0% +many as possible. And inside each one of +them, it should intersect a lot of delta + + align:start position:0% +them, it should intersect a lot of delta + + + align:start position:0% +them, it should intersect a lot of delta +balls, as many as possible. That's what + + align:start position:0% +balls, as many as possible. That's what + + + align:start position:0% +balls, as many as possible. That's what +it takes for the sub multiplicative lema + + align:start position:0% +it takes for the sub multiplicative lema + + + align:start position:0% +it takes for the sub multiplicative lema +to be sharp. + + align:start position:0% +to be sharp. + + + align:start position:0% +to be sharp. +So it should look like this. So this is + + align:start position:0% +So it should look like this. So this is + + + align:start position:0% +So it should look like this. So this is +sharp. + + align:start position:0% +sharp. + + + align:start position:0% +sharp. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um, + + align:start position:0% + + + + align:start position:0% + +and this is a kind of striking picture. + + align:start position:0% + + + + align:start position:0% + +Um, + + align:start position:0% + + + + align:start position:0% + +right. So + + align:start position:0% +right. So + + + align:start position:0% +right. So +in this ball, these points are in just a + + align:start position:0% +in this ball, these points are in just a + + + align:start position:0% +in this ball, these points are in just a +few tubes in a certain direction. Could + + align:start position:0% +few tubes in a certain direction. Could + + + align:start position:0% +few tubes in a certain direction. Could +also imagine we're in the projective + + align:start position:0% +also imagine we're in the projective + + + align:start position:0% +also imagine we're in the projective +case. And in these other balls, the + + align:start position:0% +case. And in these other balls, the + + + align:start position:0% +case. And in these other balls, the +points are in those same tubes. + + align:start position:0% +points are in those same tubes. + + + align:start position:0% +points are in those same tubes. +Goes all the way across. Of course, the + + align:start position:0% +Goes all the way across. Of course, the + + + align:start position:0% +Goes all the way across. Of course, the +balls don't have to look exactly the + + align:start position:0% +balls don't have to look exactly the + + + align:start position:0% +balls don't have to look exactly the +same as each other. So maybe a better + + align:start position:0% +same as each other. So maybe a better + + + align:start position:0% +same as each other. So maybe a better +picture might be like so. + + align:start position:0% + + + + align:start position:0% + +But the the tubes are exactly the same. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So, + + align:start position:0% + + + + align:start position:0% + +let me pause. I'm going to erase a + + align:start position:0% +let me pause. I'm going to erase a + + + align:start position:0% +let me pause. I'm going to erase a +little bit to make some space around + + align:start position:0% +little bit to make some space around + + + align:start position:0% +little bit to make some space around +here. Is that okay with everybody? that + + align:start position:0% +here. Is that okay with everybody? that + + + align:start position:0% +here. Is that okay with everybody? that +if the sub multiplicative lema is sharp, + + align:start position:0% +if the sub multiplicative lema is sharp, + + + align:start position:0% +if the sub multiplicative lema is sharp, +it has to look like this, not like that. + + align:start position:0% +it has to look like this, not like that. + + + align:start position:0% +it has to look like this, not like that. +Okay. All right. So, let's erase around + + align:start position:0% +Okay. All right. So, let's erase around + + + align:start position:0% +Okay. All right. So, let's erase around +here a little bit. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um we already reduced to the + + align:start position:0% +Okay. So, um we already reduced to the + + + align:start position:0% +Okay. So, um we already reduced to the +projective case. + + align:start position:0% + + + + align:start position:0% + +So let's say D is the set of directions + + align:start position:0% +So let's say D is the set of directions + + + align:start position:0% +So let's say D is the set of directions +which is the same everywhere as our + + align:start position:0% +which is the same everywhere as our + + + align:start position:0% +which is the same everywhere as our +projections + + align:start position:0% +projections + + + align:start position:0% +projections +and so D is a delta S set in the circle + + align:start position:0% +and so D is a delta S set in the circle + + + align:start position:0% +and so D is a delta S set in the circle +and here I fixed a typical fat tube. So + + align:start position:0% +and here I fixed a typical fat tube. So + + + align:start position:0% +and here I fixed a typical fat tube. So +here's a typical + + align:start position:0% +here's a typical + + + align:start position:0% +here's a typical +root delta tube. + + align:start position:0% + + + + align:start position:0% + +Um, and I'm going to look at the angles + + align:start position:0% +Um, and I'm going to look at the angles + + + align:start position:0% +Um, and I'm going to look at the angles +that are within this fat tube. + + align:start position:0% +that are within this fat tube. + + + align:start position:0% +that are within this fat tube. +So, um, so let's say, + + align:start position:0% +So, um, so let's say, + + + align:start position:0% +So, um, so let's say, +so here's our circle and, um, there's a + + align:start position:0% +so here's our circle and, um, there's a + + + align:start position:0% +so here's our circle and, um, there's a +little range of angles here. This is a + + align:start position:0% +little range of angles here. This is a + + + align:start position:0% +little range of angles here. This is a +delta to the here's theta, which is a + + align:start position:0% +delta to the here's theta, which is a + + + align:start position:0% +delta to the here's theta, which is a +delta to the 1/2 arc that corresponds to + + align:start position:0% +delta to the 1/2 arc that corresponds to + + + align:start position:0% +delta to the 1/2 arc that corresponds to +the that tube. + + align:start position:0% + + + + align:start position:0% + +Um okay + + align:start position:0% +Um okay + + + align:start position:0% +Um okay +and so D is some delta set delta SC set + + align:start position:0% +and so D is some delta set delta SC set + + + align:start position:0% +and so D is some delta set delta SC set +in here and let's say that C is D + + align:start position:0% +in here and let's say that C is D + + + align:start position:0% +in here and let's say that C is D +intersected with theta. So it's just + + align:start position:0% +intersected with theta. So it's just + + + align:start position:0% +intersected with theta. So it's just +these directions. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um so + + align:start position:0% +Um so + + + align:start position:0% +Um so +so the red tubes correspond to one of + + align:start position:0% +so the red tubes correspond to one of + + + align:start position:0% +so the red tubes correspond to one of +the directions in theta. So this one + + align:start position:0% +the directions in theta. So this one + + + align:start position:0% +the directions in theta. So this one +there red tube. + + align:start position:0% +there red tube. + + + align:start position:0% +there red tube. +And um so when I project the set in the + + align:start position:0% +And um so when I project the set in the + + + align:start position:0% +And um so when I project the set in the +red direction, I just get a small set. + + align:start position:0% +red direction, I just get a small set. + + + align:start position:0% +red direction, I just get a small set. +But it's not just the red direction. I + + align:start position:0% +But it's not just the red direction. I + + + align:start position:0% +But it's not just the red direction. I +could draw some other directions inside + + align:start position:0% +could draw some other directions inside + + + align:start position:0% +could draw some other directions inside +of the tube also. Let me do one more. + + align:start position:0% +of the tube also. Let me do one more. + + + align:start position:0% +of the tube also. Let me do one more. +I'll take here a blue direction inside + + align:start position:0% +I'll take here a blue direction inside + + + align:start position:0% +I'll take here a blue direction inside +of here. + + align:start position:0% +of here. + + + align:start position:0% +of here. +So I draw the tubes in the blue + + align:start position:0% +So I draw the tubes in the blue + + + align:start position:0% +So I draw the tubes in the blue +direction. What would it look like? I + + align:start position:0% +direction. What would it look like? I + + + align:start position:0% +direction. What would it look like? I +think I need to make this picture come + + align:start position:0% +think I need to make this picture come + + + align:start position:0% +think I need to make this picture come +out nicely. I need to add a few more + + align:start position:0% +out nicely. I need to add a few more + + + align:start position:0% +out nicely. I need to add a few more +points. + + align:start position:0% + + + + align:start position:0% + +And then so there'll be one more red + + align:start position:0% +And then so there'll be one more red + + + align:start position:0% +And then so there'll be one more red +tube. + + align:start position:0% +tube. + + + align:start position:0% +tube. +Oops. + + align:start position:0% + + + + align:start position:0% + +And now I'll draw a typical blue tube. + + align:start position:0% +And now I'll draw a typical blue tube. + + + align:start position:0% +And now I'll draw a typical blue tube. +The blue tube also manages to intersect + + align:start position:0% +The blue tube also manages to intersect + + + align:start position:0% +The blue tube also manages to intersect +our points a lot. So it should look sort + + align:start position:0% +our points a lot. So it should look sort + + + align:start position:0% +our points a lot. So it should look sort +of like this. + + align:start position:0% + + + + align:start position:0% + +Okay, I don't think I can draw anymore + + align:start position:0% +Okay, I don't think I can draw anymore + + + align:start position:0% +Okay, I don't think I can draw anymore +without making a complete mess, but get + + align:start position:0% +without making a complete mess, but get + + + align:start position:0% +without making a complete mess, but get +the idea. + + align:start position:0% + + + + align:start position:0% + +So the blue tube passes through all + + align:start position:0% +So the blue tube passes through all + + + align:start position:0% +So the blue tube passes through all +these balls also. And each time the blue + + align:start position:0% +these balls also. And each time the blue + + + align:start position:0% +these balls also. And each time the blue +tube passes through a ball, it manages + + align:start position:0% +tube passes through a ball, it manages + + + align:start position:0% +tube passes through a ball, it manages +to line up with one of the red tubes. + + align:start position:0% +to line up with one of the red tubes. + + + align:start position:0% +to line up with one of the red tubes. +All right. Okay. + + align:start position:0% +All right. Okay. + + + align:start position:0% +All right. Okay. +So, we have a kind of special situation + + align:start position:0% +So, we have a kind of special situation + + + align:start position:0% +So, we have a kind of special situation +here with a product structure. + + align:start position:0% +here with a product structure. + + + align:start position:0% +here with a product structure. +So, what is our set? Um, so let's say + + align:start position:0% +So, what is our set? Um, so let's say + + + align:start position:0% +So, what is our set? Um, so let's say +over here + + align:start position:0% +over here + + + align:start position:0% +over here +these dots this the projection in the + + align:start position:0% +these dots this the projection in the + + + align:start position:0% +these dots this the projection in the +red direction. Let's call this A. + + align:start position:0% +red direction. Let's call this A. + + + align:start position:0% +red direction. Let's call this A. +And then um down here we can make a set + + align:start position:0% +And then um down here we can make a set + + + align:start position:0% +And then um down here we can make a set +that illustrates where the fat balls are + + align:start position:0% +that illustrates where the fat balls are + + + align:start position:0% +that illustrates where the fat balls are +in the fat tube. Let's call that B. + + align:start position:0% + + + + align:start position:0% + +And so what we see is that for every C + + align:start position:0% +And so what we see is that for every C + + + align:start position:0% +And so what we see is that for every C +in C + + align:start position:0% +in C + + + align:start position:0% +in C +the projection + + align:start position:0% +the projection + + + align:start position:0% +the projection +uh in the C direction or I'll write it + + align:start position:0% +uh in the C direction or I'll write it + + + align:start position:0% +uh in the C direction or I'll write it +this way. A + C B that's the projection + + align:start position:0% +this way. A + C B that's the projection + + + align:start position:0% +this way. A + C B that's the projection +in the C direction + + align:start position:0% +in the C direction + + + align:start position:0% +in the C direction +is not much bigger than A. + + align:start position:0% +is not much bigger than A. + + + align:start position:0% +is not much bigger than A. +So + + align:start position:0% +So + + + align:start position:0% +So +the you know the projection in every one + + align:start position:0% +the you know the projection in every one + + + align:start position:0% +the you know the projection in every one +of these directions is small. They're + + align:start position:0% +of these directions is small. They're + + + align:start position:0% +of these directions is small. They're +all about the same as each other. A was + + align:start position:0% +all about the same as each other. A was + + + align:start position:0% +all about the same as each other. A was +the projection in the red direction. B + + align:start position:0% +the projection in the red direction. B + + + align:start position:0% +the projection in the red direction. B +the blue one is just as good. So A plus + + align:start position:0% +the blue one is just as good. So A plus + + + align:start position:0% +the blue one is just as good. So A plus +CB should be not much bigger than A. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So, let me summarize what we have + + align:start position:0% +Okay. So, let me summarize what we have + + + align:start position:0% +Okay. So, let me summarize what we have +seen here. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So + + align:start position:0% +So + + + align:start position:0% +So +f sub multiplicative lama + + align:start position:0% +f sub multiplicative lama + + + align:start position:0% +f sub multiplicative lama +is sharp. + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% +Um + + + align:start position:0% +Um +then + + align:start position:0% +then + + + align:start position:0% +then +we get sets A and B and C which are + + align:start position:0% +we get sets A and B and C which are + + + align:start position:0% +we get sets A and B and C which are +subsets of real numbers. + + align:start position:0% +subsets of real numbers. + + + align:start position:0% +subsets of real numbers. +And in the main case, + + align:start position:0% + + + + align:start position:0% + +a is a delta a a set. + + align:start position:0% +a is a delta a a set. + + + align:start position:0% +a is a delta a a set. +Well, it's a row a set. Uh size of a is + + align:start position:0% +Well, it's a row a set. Uh size of a is + + + align:start position:0% +Well, it's a row a set. Uh size of a is +like row to the minus a. + + align:start position:0% +like row to the minus a. + + + align:start position:0% +like row to the minus a. +B is a row B set. Size of B is like row + + align:start position:0% +B is a row B set. Size of B is like row + + + align:start position:0% +B is a row B set. Size of B is like row +to the minus B. C is a row C set. + + align:start position:0% +to the minus B. C is a row C set. + + + align:start position:0% +to the minus B. C is a row C set. +size of C is like row to the minus C. + + align:start position:0% +size of C is like row to the minus C. + + + align:start position:0% +size of C is like row to the minus C. +And + + align:start position:0% +And + + + align:start position:0% +And +for every C in C, + + align:start position:0% +for every C in C, + + + align:start position:0% +for every C in C, +A + CB is not very much bigger than A. + + align:start position:0% + + + + align:start position:0% + +Okay. Now, the size of A and B and C can + + align:start position:0% +Okay. Now, the size of A and B and C can + + + align:start position:0% +Okay. Now, the size of A and B and C can +all be traced back to the numbers in our + + align:start position:0% +all be traced back to the numbers in our + + + align:start position:0% +all be traced back to the numbers in our +problem. + + align:start position:0% +problem. + + + align:start position:0% +problem. +Um and + + align:start position:0% +Um and + + + align:start position:0% +Um and +we find that if uh + + align:start position:0% +we find that if uh + + + align:start position:0% +we find that if uh +if a is smaller than b + c that's + + align:start position:0% +if a is smaller than b + c that's + + + align:start position:0% +if a is smaller than b + c that's +equivalent to saying that ra a d square + + align:start position:0% +equivalent to saying that ra a d square + + + align:start position:0% +equivalent to saying that ra a d square +root of delta is good + + align:start position:0% +root of delta is good + + + align:start position:0% +root of delta is good +a sorry if a is larger than b plus c + + align:start position:0% +a sorry if a is larger than b plus c + + + align:start position:0% +a sorry if a is larger than b plus c +then that means you do a boring + + align:start position:0% +then that means you do a boring + + + align:start position:0% +then that means you do a boring +computation. + + align:start position:0% + + + + align:start position:0% + +Um so there's a + + align:start position:0% +Um so there's a + + + align:start position:0% +Um so there's a +intermediate result maybe I'll call it a + + align:start position:0% +intermediate result maybe I'll call it a + + + align:start position:0% +intermediate result maybe I'll call it a +key lema which is called the ABC sum + + align:start position:0% +key lema which is called the ABC sum + + + align:start position:0% +key lema which is called the ABC sum +product lema + + align:start position:0% + + + + align:start position:0% + +which is goes into this paper of open + + align:start position:0% +which is goes into this paper of open + + + align:start position:0% +which is goes into this paper of open +schwarin. Uh, and it says if you have + + align:start position:0% +schwarin. Uh, and it says if you have + + + align:start position:0% +schwarin. Uh, and it says if you have +all of this stuff, um, then indeed a is + + align:start position:0% +all of this stuff, um, then indeed a is + + + align:start position:0% +all of this stuff, um, then indeed a is +bigger than b + c. + + align:start position:0% + + + + align:start position:0% + +Okay, let's yeah, + + align:start position:0% +Okay, let's yeah, + + + align:start position:0% +Okay, let's yeah, +>> good means that it obeys the theorem. + + align:start position:0% + + + + align:start position:0% + +Um so the theorem's up there. So smaller + + align:start position:0% +Um so the theorem's up there. So smaller + + + align:start position:0% +Um so the theorem's up there. So smaller +than the maximum of one and + + align:start position:0% +than the maximum of one and + + + align:start position:0% +than the maximum of one and +root delta to the minus t / 2 + s / 2 + + align:start position:0% +root delta to the minus t / 2 + s / 2 + + + align:start position:0% +root delta to the minus t / 2 + s / 2 +and root delta to the 1us t. + + align:start position:0% +and root delta to the 1us t. + + + align:start position:0% +and root delta to the 1us t. +So if if that's the case, we're we're + + align:start position:0% +So if if that's the case, we're we're + + + align:start position:0% +So if if that's the case, we're we're +happy. And otherwise uh yeah. Okay. + + align:start position:0% +happy. And otherwise uh yeah. Okay. + + + align:start position:0% +happy. And otherwise uh yeah. Okay. +Right. + + align:start position:0% + + + + align:start position:0% + +Okay. So, let's go back to our general + + align:start position:0% +Okay. So, let's go back to our general + + + align:start position:0% +Okay. So, let's go back to our general +strategy, our big our big picture + + align:start position:0% +strategy, our big our big picture + + + align:start position:0% +strategy, our big our big picture +strategy. We'd like to prove this + + align:start position:0% +strategy. We'd like to prove this + + + align:start position:0% +strategy. We'd like to prove this +theorem that RA of delta is always + + align:start position:0% +theorem that RA of delta is always + + + align:start position:0% +theorem that RA of delta is always +smaller than that. + + align:start position:0% +smaller than that. + + + align:start position:0% +smaller than that. +And we consider the sub multiplicative + + align:start position:0% +And we consider the sub multiplicative + + + align:start position:0% +And we consider the sub multiplicative +limit which doesn't give us the theorem + + align:start position:0% +limit which doesn't give us the theorem + + + align:start position:0% +limit which doesn't give us the theorem +yet, but it's an important tool. + + align:start position:0% +yet, but it's an important tool. + + + align:start position:0% +yet, but it's an important tool. +And we'd like to say + + align:start position:0% +And we'd like to say + + + align:start position:0% +And we'd like to say +um + + align:start position:0% +um + + + align:start position:0% +um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +if if the if we can have an epsilon + + align:start position:0% +if if the if we can have an epsilon + + + align:start position:0% +if if the if we can have an epsilon +improvement in the sub multiplicative + + align:start position:0% +improvement in the sub multiplicative + + + align:start position:0% +improvement in the sub multiplicative +lema then that's great. We go to the + + align:start position:0% +lema then that's great. We go to the + + + align:start position:0% +lema then that's great. We go to the +next scale and we have a better bound. + + align:start position:0% +next scale and we have a better bound. + + + align:start position:0% +next scale and we have a better bound. +So you keep doing that until you stop + + align:start position:0% +So you keep doing that until you stop + + + align:start position:0% +So you keep doing that until you stop +and we must stop in a situation where + + align:start position:0% +and we must stop in a situation where + + + align:start position:0% +and we must stop in a situation where +there's no more where the sub + + align:start position:0% +there's no more where the sub + + + align:start position:0% +there's no more where the sub +multiplicative lema becomes sharp. + + align:start position:0% +multiplicative lema becomes sharp. + + + align:start position:0% +multiplicative lema becomes sharp. +And maybe that's a better way to say it. + + align:start position:0% +And maybe that's a better way to say it. + + + align:start position:0% +And maybe that's a better way to say it. +We have the sub multiplicative lama. we + + align:start position:0% +We have the sub multiplicative lama. we + + + align:start position:0% +We have the sub multiplicative lama. we +use it. It's either sharp or it's not. + + align:start position:0% +use it. It's either sharp or it's not. + + + align:start position:0% +use it. It's either sharp or it's not. +If it's not, we get a, you know, a nicer + + align:start position:0% +If it's not, we get a, you know, a nicer + + + align:start position:0% +If it's not, we get a, you know, a nicer +exponent at at delta squared than we did + + align:start position:0% +exponent at at delta squared than we did + + + align:start position:0% +exponent at at delta squared than we did +at delta. We keep doing that and the + + align:start position:0% +at delta. We keep doing that and the + + + align:start position:0% +at delta. We keep doing that and the +exponent is not going to keep getting + + align:start position:0% +exponent is not going to keep getting + + + align:start position:0% +exponent is not going to keep getting +better forever. So, we stop at some + + align:start position:0% +better forever. So, we stop at some + + + align:start position:0% +better forever. So, we stop at some +moment where the sub multiplicative lama + + align:start position:0% +moment where the sub multiplicative lama + + + align:start position:0% +moment where the sub multiplicative lama +is basically sharp. + + align:start position:0% +is basically sharp. + + + align:start position:0% +is basically sharp. +But the fact that the sub multiplicative + + align:start position:0% +But the fact that the sub multiplicative + + + align:start position:0% +But the fact that the sub multiplicative +lama is sharp gives us a lot of + + align:start position:0% +lama is sharp gives us a lot of + + + align:start position:0% +lama is sharp gives us a lot of +structure. It gives us uh the structure + + align:start position:0% +structure. It gives us uh the structure + + + align:start position:0% +structure. It gives us uh the structure +of being projective + + align:start position:0% +of being projective + + + align:start position:0% +of being projective +and it gives us this kind of product + + align:start position:0% +and it gives us this kind of product + + + align:start position:0% +and it gives us this kind of product +structure and it leads us to this + + align:start position:0% +structure and it leads us to this + + + align:start position:0% +structure and it leads us to this +problem which looks a lot like additive + + align:start position:0% +problem which looks a lot like additive + + + align:start position:0% +problem which looks a lot like additive +combinotaurics and which is very special + + align:start position:0% +combinotaurics and which is very special + + + align:start position:0% +combinotaurics and which is very special +problem compared to our original setup. + + align:start position:0% +problem compared to our original setup. + + + align:start position:0% +problem compared to our original setup. +Um okay and then the bound we need to + + align:start position:0% +Um okay and then the bound we need to + + + align:start position:0% +Um okay and then the bound we need to +prove for this problem if you just + + align:start position:0% +prove for this problem if you just + + + align:start position:0% +prove for this problem if you just +unwind the computation we need to prove + + align:start position:0% +unwind the computation we need to prove + + + align:start position:0% +unwind the computation we need to prove +this bound for this problem and if you + + align:start position:0% +this bound for this problem and if you + + + align:start position:0% +this bound for this problem and if you +unwind it it will tell us that um that + + align:start position:0% +unwind it it will tell us that um that + + + align:start position:0% +unwind it it will tell us that um that +ra obeys the desired bound + + align:start position:0% + + + + align:start position:0% + +yeah row I guess row is also row here is + + align:start position:0% +yeah row I guess row is also row here is + + + align:start position:0% +yeah row I guess row is also row here is +square root of delta + + align:start position:0% +square root of delta + + + align:start position:0% +square root of delta +Yeah. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Okay. So this situation + + align:start position:0% +Okay. So this situation + + + align:start position:0% +Okay. So this situation +is now a lot more structured than what + + align:start position:0% +is now a lot more structured than what + + + align:start position:0% +is now a lot more structured than what +we started with and it looks reminiscent + + align:start position:0% +we started with and it looks reminiscent + + + align:start position:0% +we started with and it looks reminiscent +of uh additive cominatorics maybe of + + align:start position:0% +of uh additive cominatorics maybe of + + + align:start position:0% +of uh additive cominatorics maybe of +brian projection theorem and so on and + + align:start position:0% +brian projection theorem and so on and + + + align:start position:0% +brian projection theorem and so on and +indeed they were able to deal with it + + align:start position:0% +indeed they were able to deal with it + + + align:start position:0% +indeed they were able to deal with it +with that toolkit. + + align:start position:0% +with that toolkit. + + + align:start position:0% +with that toolkit. +I could say a little I don't I don't + + align:start position:0% +I could say a little I don't I don't + + + align:start position:0% +I could say a little I don't I don't +want to write too many equations so I + + align:start position:0% +want to write too many equations so I + + + align:start position:0% +want to write too many equations so I +won't say the whole thing. I could say a + + align:start position:0% +won't say the whole thing. I could say a + + + align:start position:0% +won't say the whole thing. I could say a +little bit about it. Um, but I I think + + align:start position:0% +little bit about it. Um, but I I think + + + align:start position:0% +little bit about it. Um, but I I think +that what we've done so far is what what + + align:start position:0% +that what we've done so far is what what + + + align:start position:0% +that what we've done so far is what what +I feel is most worth remembering about + + align:start position:0% +I feel is most worth remembering about + + + align:start position:0% +I feel is most worth remembering about +the proof of this theorem. So, let's + + align:start position:0% +the proof of this theorem. So, let's + + + align:start position:0% +the proof of this theorem. So, let's +pause here and see if people have any + + align:start position:0% +pause here and see if people have any + + + align:start position:0% +pause here and see if people have any +questions or comments about + + align:start position:0% + + + + align:start position:0% + +Let me let me summarize it. + + align:start position:0% +Let me let me summarize it. + + + align:start position:0% +Let me let me summarize it. +So the ad regular case is special + + align:start position:0% +So the ad regular case is special + + + align:start position:0% +So the ad regular case is special +because all the scales are related to + + align:start position:0% +because all the scales are related to + + + align:start position:0% +because all the scales are related to +each other and so we can break it up + + align:start position:0% +each other and so we can break it up + + + align:start position:0% +each other and so we can break it up +into problems at different scales and + + align:start position:0% +into problems at different scales and + + + align:start position:0% +into problems at different scales and +put them together. And by doing that we + + align:start position:0% +put them together. And by doing that we + + + align:start position:0% +put them together. And by doing that we +get problems that are somewhat nicer. So + + align:start position:0% +get problems that are somewhat nicer. So + + + align:start position:0% +get problems that are somewhat nicer. So +first of all if we look at the problem + + align:start position:0% +first of all if we look at the problem + + + align:start position:0% +first of all if we look at the problem +in a small ball instead of the original + + align:start position:0% +in a small ball instead of the original + + + align:start position:0% +in a small ball instead of the original +problem it becomes nicer because the + + align:start position:0% +problem it becomes nicer because the + + + align:start position:0% +problem it becomes nicer because the +directions through any point are the + + align:start position:0% +directions through any point are the + + + align:start position:0% +directions through any point are the +same for any two points. the directions + + align:start position:0% +same for any two points. the directions + + + align:start position:0% +same for any two points. the directions +are the same because they correspond to + + align:start position:0% +are the same because they correspond to + + + align:start position:0% +are the same because they correspond to +the directions of the fat tube through + + align:start position:0% +the directions of the fat tube through + + + align:start position:0% +the directions of the fat tube through +there. So this already made it a little + + align:start position:0% +there. So this already made it a little + + + align:start position:0% +there. So this already made it a little +bit nicer. + + align:start position:0% +bit nicer. + + + align:start position:0% +bit nicer. +Then moreover in order for the sub + + align:start position:0% +Then moreover in order for the sub + + + align:start position:0% +Then moreover in order for the sub +multiplicative lema to be sharp. So if + + align:start position:0% +multiplicative lema to be sharp. So if + + + align:start position:0% +multiplicative lema to be sharp. So if +the sub multiplicative lema is not sharp + + align:start position:0% +the sub multiplicative lema is not sharp + + + align:start position:0% +the sub multiplicative lema is not sharp +then you just keep going down scales and + + align:start position:0% +then you just keep going down scales and + + + align:start position:0% +then you just keep going down scales and +you keep getting better exponents and + + align:start position:0% +you keep getting better exponents and + + + align:start position:0% +you keep getting better exponents and +eventually that has to stop when the sub + + align:start position:0% +eventually that has to stop when the sub + + + align:start position:0% +eventually that has to stop when the sub +multiplicative lema is sharp. when the + + align:start position:0% +multiplicative lema is sharp. when the + + + align:start position:0% +multiplicative lema is sharp. when the +sub multiplicative lema is sharp, + + align:start position:0% +sub multiplicative lema is sharp, + + + align:start position:0% +sub multiplicative lema is sharp, +there's even more structure because + + align:start position:0% +there's even more structure because + + + align:start position:0% +there's even more structure because +these different balls have to talk to + + align:start position:0% +these different balls have to talk to + + + align:start position:0% +these different balls have to talk to +each other. Um, and so if you know + + align:start position:0% +each other. Um, and so if you know + + + align:start position:0% +each other. Um, and so if you know +there's a if if you see in this ball, + + align:start position:0% +there's a if if you see in this ball, + + + align:start position:0% +there's a if if you see in this ball, +you see a tube here, then you have to + + align:start position:0% +you see a tube here, then you have to + + + align:start position:0% +you see a tube here, then you have to +see a tube in the same place in that + + align:start position:0% +see a tube in the same place in that + + + align:start position:0% +see a tube in the same place in that +ball. + + align:start position:0% +ball. + + + align:start position:0% +ball. +Um, and that means that this set of + + align:start position:0% +Um, and that means that this set of + + + align:start position:0% +Um, and that means that this set of +points has kind of a product structure. + + align:start position:0% +points has kind of a product structure. + + + align:start position:0% +points has kind of a product structure. +And in particular if you what what's + + align:start position:0% +And in particular if you what what's + + + align:start position:0% +And in particular if you what what's +literally true is that if you take this + + align:start position:0% +literally true is that if you take this + + + align:start position:0% +literally true is that if you take this +uh well anyway so if you if you take the + + align:start position:0% +uh well anyway so if you if you take the + + + align:start position:0% +uh well anyway so if you if you take the +set of red tubes in this ball and then + + align:start position:0% +set of red tubes in this ball and then + + + align:start position:0% +set of red tubes in this ball and then +in this ball and then in this ball that + + align:start position:0% +in this ball and then in this ball that + + + align:start position:0% +in this ball and then in this ball that +is a product which is very helpful. + + align:start position:0% +is a product which is very helpful. + + + align:start position:0% +is a product which is very helpful. +Okay. Um + + align:start position:0% +Okay. Um + + + align:start position:0% +Okay. Um +cool. So, + + align:start position:0% +cool. So, + + + align:start position:0% +cool. So, +so the the the ad regular case allows us + + align:start position:0% +so the the the ad regular case allows us + + + align:start position:0% +so the the the ad regular case allows us +to restrict to a situation which has a + + align:start position:0% +to restrict to a situation which has a + + + align:start position:0% +to restrict to a situation which has a +lot more structure and uh it restricts + + align:start position:0% +lot more structure and uh it restricts + + + align:start position:0% +lot more structure and uh it restricts +to to to this lema about projections of + + align:start position:0% +to to to this lema about projections of + + + align:start position:0% +to to to this lema about projections of +a product set. + + align:start position:0% +a product set. + + + align:start position:0% +a product set. +>> Okay. Yeah. Um, so the argument like can + + align:start position:0% +>> Okay. Yeah. Um, so the argument like can + + + align:start position:0% +>> Okay. Yeah. Um, so the argument like can +continue sort of until the + + align:start position:0% +continue sort of until the + + + align:start position:0% +continue sort of until the +more is sharp. How do you know that kind + + align:start position:0% +more is sharp. How do you know that kind + + + align:start position:0% +more is sharp. How do you know that kind +of sharpness corresponds to kind of the + + align:start position:0% +of sharpness corresponds to kind of the + + + align:start position:0% +of sharpness corresponds to kind of the +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +delta to the epsilon factor rather than + + align:start position:0% +delta to the epsilon factor rather than + + + align:start position:0% +delta to the epsilon factor rather than +just kind of something much smaller? + + align:start position:0% +just kind of something much smaller? + + + align:start position:0% +just kind of something much smaller? +It's seems like I don't I don't + + align:start position:0% +It's seems like I don't I don't + + + align:start position:0% +It's seems like I don't I don't +understand how to kind of get a + + align:start position:0% +understand how to kind of get a + + + align:start position:0% +understand how to kind of get a +quantitative bound kind of a more + + align:start position:0% +quantitative bound kind of a more + + + align:start position:0% +quantitative bound kind of a more +qualitative proof by contradiction. + + align:start position:0% +qualitative proof by contradiction. + + + align:start position:0% +qualitative proof by contradiction. +>> Yeah. Okay. Okay. So the quest this + + align:start position:0% +>> Yeah. Okay. Okay. So the quest this + + + align:start position:0% +>> Yeah. Okay. Okay. So the quest this +question is about keeping track of the + + align:start position:0% +question is about keeping track of the + + + align:start position:0% +question is about keeping track of the +small parameters. So every time I apply + + align:start position:0% +small parameters. So every time I apply + + + align:start position:0% +small parameters. So every time I apply +the sub multiplicative lema + + align:start position:0% +the sub multiplicative lema + + + align:start position:0% +the sub multiplicative lema +I was using the word sharp or not sharp + + align:start position:0% +I was using the word sharp or not sharp + + + align:start position:0% +I was using the word sharp or not sharp +but of course there's some kind of a + + align:start position:0% +but of course there's some kind of a + + + align:start position:0% +but of course there's some kind of a +gray zone and I have to decide where I'm + + align:start position:0% +gray zone and I have to decide where I'm + + + align:start position:0% +gray zone and I have to decide where I'm +going to cut how how what am I going to + + align:start position:0% +going to cut how how what am I going to + + + align:start position:0% +going to cut how how what am I going to +consider to be sharp and what is not + + align:start position:0% +consider to be sharp and what is not + + + align:start position:0% +consider to be sharp and what is not +sharp. Um and um then + + align:start position:0% +sharp. Um and um then + + + align:start position:0% +sharp. Um and um then +in this analysis um + + align:start position:0% +in this analysis um + + + align:start position:0% +in this analysis um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um yeah okay so so actually so in in + + align:start position:0% +um yeah okay so so actually so in in + + + align:start position:0% +um yeah okay so so actually so in in +order for this to stop in a reasonable + + align:start position:0% +order for this to stop in a reasonable + + + align:start position:0% +order for this to stop in a reasonable +amount of time I'm going to have to have + + align:start position:0% +amount of time I'm going to have to have + + + align:start position:0% +amount of time I'm going to have to have +a cutoff that's a tiny power of delta + + align:start position:0% +a cutoff that's a tiny power of delta + + + align:start position:0% +a cutoff that's a tiny power of delta +otherwise this would go on too long + + align:start position:0% +otherwise this would go on too long + + + align:start position:0% +otherwise this would go on too long +wouldn't work. Um, so my so I would say + + align:start position:0% +wouldn't work. Um, so my so I would say + + + align:start position:0% +wouldn't work. Um, so my so I would say +um + + align:start position:0% +um + + + align:start position:0% +um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so what would the definition of sharp + + align:start position:0% +so what would the definition of sharp + + + align:start position:0% +so what would the definition of sharp +be? + + align:start position:0% +be? + + + align:start position:0% +be? +Keep that. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +All right, let's get rid of this stuff. + + align:start position:0% +All right, let's get rid of this stuff. + + + align:start position:0% +All right, let's get rid of this stuff. +So we're going to we're going to use the + + align:start position:0% +So we're going to we're going to use the + + + align:start position:0% +So we're going to we're going to use the +sub multiplicative lama + + align:start position:0% +sub multiplicative lama + + + align:start position:0% +sub multiplicative lama +repeatedly. + + align:start position:0% + + + + align:start position:0% + +And so if ra a d of delta is bigger than + + align:start position:0% +And so if ra a d of delta is bigger than + + + align:start position:0% +And so if ra a d of delta is bigger than +I need to put something here ra a d of + + align:start position:0% +I need to put something here ra a d of + + + align:start position:0% +I need to put something here ra a d of +root delta squared and here I'm going to + + align:start position:0% +root delta squared and here I'm going to + + + align:start position:0% +root delta squared and here I'm going to +put delta to the epsilon kn where + + align:start position:0% +put delta to the epsilon kn where + + + align:start position:0% +put delta to the epsilon kn where +epsilon kn is a tiny parameter then I'm + + align:start position:0% +epsilon kn is a tiny parameter then I'm + + + align:start position:0% +epsilon kn is a tiny parameter then I'm +going to call this sharp + + align:start position:0% +going to call this sharp + + + align:start position:0% +going to call this sharp +and I'm going to stop and analyze + + align:start position:0% + + + + align:start position:0% + +the Other possibility is that RA A of + + align:start position:0% +the Other possibility is that RA A of + + + align:start position:0% +the Other possibility is that RA A of +delta is less than delta to the epsilon + + align:start position:0% +delta is less than delta to the epsilon + + + align:start position:0% +delta is less than delta to the epsilon +KN RA a + + align:start position:0% +KN RA a + + + align:start position:0% +KN RA a +root delta squared. And here I'm making + + align:start position:0% +root delta squared. And here I'm making + + + align:start position:0% +root delta squared. And here I'm making +progress. So I'll keep going. So this is + + align:start position:0% +progress. So I'll keep going. So this is + + + align:start position:0% +progress. So I'll keep going. So this is +the not sharp case. + + align:start position:0% +the not sharp case. + + + align:start position:0% +the not sharp case. +So now I'll keep going. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's that's if we're more + + align:start position:0% +Okay. So that's that's if we're more + + + align:start position:0% +Okay. So that's that's if we're more +careful about what is sharp and not + + align:start position:0% +careful about what is sharp and not + + + align:start position:0% +careful about what is sharp and not +sharpening. All right. So here um if I + + align:start position:0% +sharpening. All right. So here um if I + + + align:start position:0% +sharpening. All right. So here um if I +keep going every time I make a definite + + align:start position:0% +keep going every time I make a definite + + + align:start position:0% +keep going every time I make a definite +amount of progress and so uh this this + + align:start position:0% +amount of progress and so uh this this + + + align:start position:0% +amount of progress and so uh this this +actually cannot keep going forever + + align:start position:0% +actually cannot keep going forever + + + align:start position:0% +actually cannot keep going forever +because eventually the exponents would + + align:start position:0% +because eventually the exponents would + + + align:start position:0% +because eventually the exponents would +be negative instead of positive. So it + + align:start position:0% +be negative instead of positive. So it + + + align:start position:0% +be negative instead of positive. So it +will stop. So we will end up here. Once + + align:start position:0% +will stop. So we will end up here. Once + + + align:start position:0% +will stop. So we will end up here. Once +we end up here we have to analyze the + + align:start position:0% +we end up here we have to analyze the + + + align:start position:0% +we end up here we have to analyze the +sharp case and we do have to remember it + + align:start position:0% +sharp case and we do have to remember it + + + align:start position:0% +sharp case and we do have to remember it +wasn't perfectly sharp but we had a + + align:start position:0% +wasn't perfectly sharp but we had a + + + align:start position:0% +wasn't perfectly sharp but we had a +fudge factor of a tiny power of delta + + align:start position:0% +fudge factor of a tiny power of delta + + + align:start position:0% +fudge factor of a tiny power of delta +and that complicates all the pictures + + align:start position:0% +and that complicates all the pictures + + + align:start position:0% +and that complicates all the pictures +that we have drawn. So in this picture + + align:start position:0% +that we have drawn. So in this picture + + + align:start position:0% +that we have drawn. So in this picture +here, + + align:start position:0% +here, + + + align:start position:0% +here, +this tube goes through many fat tubes. + + align:start position:0% +this tube goes through many fat tubes. + + + align:start position:0% +this tube goes through many fat tubes. +It doesn't have to have many delta balls + + align:start position:0% +It doesn't have to have many delta balls + + + align:start position:0% +It doesn't have to have many delta balls +in all of them. It has to have many + + align:start position:0% +in all of them. It has to have many + + + align:start position:0% +in all of them. It has to have many +delta balls in a fraction like delta to + + align:start position:0% +delta balls in a fraction like delta to + + + align:start position:0% +delta balls in a fraction like delta to +the epsilon, not fraction of them. It + + align:start position:0% +the epsilon, not fraction of them. It + + + align:start position:0% +the epsilon, not fraction of them. It +makes the picture a little bit more + + align:start position:0% +makes the picture a little bit more + + + align:start position:0% +makes the picture a little bit more +complicated. Um and actually because of + + align:start position:0% +complicated. Um and actually because of + + + align:start position:0% +complicated. Um and actually because of +that in in this theorem, + + align:start position:0% +that in in this theorem, + + + align:start position:0% +that in in this theorem, +if we're honest, it's a little bit more + + align:start position:0% +if we're honest, it's a little bit more + + + align:start position:0% +if we're honest, it's a little bit more +complicated. It's not um so it's um + + align:start position:0% +complicated. It's not um so it's um + + + align:start position:0% +complicated. It's not um so it's um +this would actually be pi c of x where x + + align:start position:0% +this would actually be pi c of x where x + + + align:start position:0% +this would actually be pi c of x where x +is a subset of a cross b and it's like a + + align:start position:0% +is a subset of a cross b and it's like a + + + align:start position:0% +is a subset of a cross b and it's like a +delta to the epsilon subset. + + align:start position:0% + + + + align:start position:0% + +So we wouldn't have to fill the whole + + align:start position:0% +So we wouldn't have to fill the whole + + + align:start position:0% +So we wouldn't have to fill the whole +product. we'd only have. + + align:start position:0% +product. we'd only have. + + + align:start position:0% +product. we'd only have. +Okay. So for that's what how we would be + + align:start position:0% +Okay. So for that's what how we would be + + + align:start position:0% +Okay. So for that's what how we would be +careful about sharp and how we would + + align:start position:0% +careful about sharp and how we would + + + align:start position:0% +careful about sharp and how we would +have to be more careful here. + + align:start position:0% + + + + align:start position:0% + +Okay. Um let me tell you just the first + + align:start position:0% +Okay. Um let me tell you just the first + + + align:start position:0% +Okay. Um let me tell you just the first +idea of the of the proof of um of this + + align:start position:0% +idea of the of the proof of um of this + + + align:start position:0% +idea of the of the proof of um of this +key lama. + + align:start position:0% + + + + align:start position:0% + +So um so we have + + align:start position:0% +So um so we have + + + align:start position:0% +So um so we have +just a step proof + + align:start position:0% +just a step proof + + + align:start position:0% +just a step proof +um so we have a plus cb is only a little + + align:start position:0% +um so we have a plus cb is only a little + + + align:start position:0% +um so we have a plus cb is only a little +bit bigger than a + + align:start position:0% +bit bigger than a + + + align:start position:0% +bit bigger than a +um that reminds us of plunicus. So an + + align:start position:0% +um that reminds us of plunicus. So an + + + align:start position:0% +um that reminds us of plunicus. So an +appropriate version of plunicusia + + align:start position:0% +appropriate version of plunicusia + + + align:start position:0% +appropriate version of plunicusia +well okay we have this big subset x we + + align:start position:0% +well okay we have this big subset x we + + + align:start position:0% +well okay we have this big subset x we +might want to get rid of that by doing + + align:start position:0% +might want to get rid of that by doing + + + align:start position:0% +might want to get rid of that by doing +bix gowers. Um so a val 80 hours would + + align:start position:0% +bix gowers. Um so a val 80 hours would + + + align:start position:0% +bix gowers. Um so a val 80 hours would +reduce + + align:start position:0% +reduce + + + align:start position:0% +reduce +to um a prime plus c b prime smaller + + align:start position:0% +to um a prime plus c b prime smaller + + + align:start position:0% +to um a prime plus c b prime smaller +than a prime we actually have all of it + + align:start position:0% +than a prime we actually have all of it + + + align:start position:0% +than a prime we actually have all of it +instead of just a big piece of it and + + align:start position:0% +instead of just a big piece of it and + + + align:start position:0% +instead of just a big piece of it and +then uh plunicus + + align:start position:0% +then uh plunicus + + + align:start position:0% +then uh plunicus +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +would give us so this would be true for + + align:start position:0% +would give us so this would be true for + + + align:start position:0% +would give us so this would be true for +man c and c + + align:start position:0% +man c and c + + + align:start position:0% +man c and c +and that would give us a prime prime + + align:start position:0% +and that would give us a prime prime + + + align:start position:0% +and that would give us a prime prime +plus C1 B prime plus C2 B prime plus C3 + + align:start position:0% +plus C1 B prime plus C2 B prime plus C3 + + + align:start position:0% +plus C1 B prime plus C2 B prime plus C3 +B prime would still be smaller than A + + align:start position:0% +B prime would still be smaller than A + + + align:start position:0% +B prime would still be smaller than A +prime could get that from plunicus + + align:start position:0% +prime could get that from plunicus + + + align:start position:0% +prime could get that from plunicus +okay and so now you we're not done yet + + align:start position:0% +okay and so now you we're not done yet + + + align:start position:0% +okay and so now you we're not done yet +but you sort of have the feeling that + + align:start position:0% +but you sort of have the feeling that + + + align:start position:0% +but you sort of have the feeling that +we keep using these tools from additive + + align:start position:0% +we keep using these tools from additive + + + align:start position:0% +we keep using these tools from additive +commentary we keep having stronger and + + align:start position:0% +commentary we keep having stronger and + + + align:start position:0% +commentary we keep having stronger and +stronger sounding uh information about A + + align:start position:0% +stronger sounding uh information about A + + + align:start position:0% +stronger sounding uh information about A +and B more and more suspicious + + align:start position:0% + + + + align:start position:0% + +okay And it definitely takes some some + + align:start position:0% +okay And it definitely takes some some + + + align:start position:0% +okay And it definitely takes some some +skill and some some good ideas to to + + align:start position:0% +skill and some some good ideas to to + + + align:start position:0% +skill and some some good ideas to to +finish from here. But we're in a setting + + align:start position:0% +finish from here. But we're in a setting + + + align:start position:0% +finish from here. But we're in a setting +where the tools of additive + + align:start position:0% +where the tools of additive + + + align:start position:0% +where the tools of additive +combinatorics are quite powerful and + + align:start position:0% +combinatorics are quite powerful and + + + align:start position:0% +combinatorics are quite powerful and +they're able to analyze what happens. + + align:start position:0% + + + + align:start position:0% + +Okay, good. + + align:start position:0% + + + + align:start position:0% + +Any final questions or comments? + + align:start position:0% +Any final questions or comments? + + + align:start position:0% +Any final questions or comments? +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> How did we reduce the projected case? we + + align:start position:0% +>> How did we reduce the projected case? we + + + align:start position:0% +>> How did we reduce the projected case? we +reduced to the projective case at the + + align:start position:0% +reduced to the projective case at the + + + align:start position:0% +reduced to the projective case at the +beginning. Um we said uh so after we had + + align:start position:0% +beginning. Um we said uh so after we had + + + align:start position:0% +beginning. Um we said uh so after we had +the um sub multiplicative lama we + + align:start position:0% +the um sub multiplicative lama we + + + align:start position:0% +the um sub multiplicative lama we +reduced to the projective case by saying + + align:start position:0% +reduced to the projective case by saying + + + align:start position:0% +reduced to the projective case by saying +that um this ball is in the projective + + align:start position:0% +that um this ball is in the projective + + + align:start position:0% +that um this ball is in the projective +case. + + align:start position:0% +case. + + + align:start position:0% +case. +Um and so using that we were able to + + align:start position:0% +Um and so using that we were able to + + + align:start position:0% +Um and so using that we were able to +show that it suffices to prove it for + + align:start position:0% +show that it suffices to prove it for + + + align:start position:0% +show that it suffices to prove it for +the projective case. + + align:start position:0% +the projective case. + + + align:start position:0% +the projective case. +How do you put that? How do you chain + + align:start position:0% +How do you put that? How do you chain + + + align:start position:0% +How do you put that? How do you chain +that argument? + + align:start position:0% + + + + align:start position:0% + +>> What's that like? Like like I I don't + + align:start position:0% +>> What's that like? Like like I I don't + + + align:start position:0% +>> What's that like? Like like I I don't +understand how you use uh like that kind + + align:start position:0% +understand how you use uh like that kind + + + align:start position:0% +understand how you use uh like that kind +of argument and the and the reduction at + + align:start position:0% +of argument and the and the reduction at + + + align:start position:0% +of argument and the and the reduction at +the same time. + + align:start position:0% +the same time. + + + align:start position:0% +the same time. +>> Ah um so the question is about how we + + align:start position:0% +>> Ah um so the question is about how we + + + align:start position:0% +>> Ah um so the question is about how we +put together reducing to the projective + + align:start position:0% +put together reducing to the projective + + + align:start position:0% +put together reducing to the projective +case with all the other things that we + + align:start position:0% +case with all the other things that we + + + align:start position:0% +case with all the other things that we +did. Yeah. Um + + align:start position:0% +did. Yeah. Um + + + align:start position:0% +did. Yeah. Um +um okay. So, + + align:start position:0% +um okay. So, + + + align:start position:0% +um okay. So, +so using this lama, we had an argument + + align:start position:0% +so using this lama, we had an argument + + + align:start position:0% +so using this lama, we had an argument +that if you could prove a good bound for + + align:start position:0% +that if you could prove a good bound for + + + align:start position:0% +that if you could prove a good bound for +the projective case, then combining it + + align:start position:0% +the projective case, then combining it + + + align:start position:0% +the projective case, then combining it +with this lama and and noticing that + + align:start position:0% +with this lama and and noticing that + + + align:start position:0% +with this lama and and noticing that +this is projective that then we get a + + align:start position:0% +this is projective that then we get a + + + align:start position:0% +this is projective that then we get a +good bound for the general case. So now + + align:start position:0% +good bound for the general case. So now + + + align:start position:0% +good bound for the general case. So now +we just imagine we're trying to prove + + align:start position:0% +we just imagine we're trying to prove + + + align:start position:0% +we just imagine we're trying to prove +the theorem in the projective case. + + align:start position:0% +the theorem in the projective case. + + + align:start position:0% +the theorem in the projective case. +Um so we can assume that we're in the + + align:start position:0% +Um so we can assume that we're in the + + + align:start position:0% +Um so we can assume that we're in the +projective case + + align:start position:0% +projective case + + + align:start position:0% +projective case +and then we start applying the sub + + align:start position:0% +and then we start applying the sub + + + align:start position:0% +and then we start applying the sub +multiplicative lema. + + align:start position:0% +multiplicative lema. + + + align:start position:0% +multiplicative lema. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +ah so you're wondering when we do this + + align:start position:0% + + + + align:start position:0% + +yeah you can so you can think of this in + + align:start position:0% +yeah you can so you can think of this in + + + align:start position:0% +yeah you can so you can think of this in +this picture um where over here we have + + align:start position:0% +this picture um where over here we have + + + align:start position:0% +this picture um where over here we have +um not just some abstract thing but the + + align:start position:0% +um not just some abstract thing but the + + + align:start position:0% +um not just some abstract thing but the +this would be the R in the small ball + + align:start position:0% +this would be the R in the small ball + + + align:start position:0% +this would be the R in the small ball +and the R for the fat tubes. So, we look + + align:start position:0% +and the R for the fat tubes. So, we look + + + align:start position:0% +and the R for the fat tubes. So, we look +at those and if if the R if the R is + + align:start position:0% +at those and if if the R if the R is + + + align:start position:0% +at those and if if the R if the R is +better than multiplying the small balls + + align:start position:0% +better than multiplying the small balls + + + align:start position:0% +better than multiplying the small balls +times the fat tubes, then we keep + + align:start position:0% +times the fat tubes, then we keep + + + align:start position:0% +times the fat tubes, then we keep +breaking things up. Take the small balls + + align:start position:0% +breaking things up. Take the small balls + + + align:start position:0% +breaking things up. Take the small balls +and break them into smaller balls. And + + align:start position:0% +and break them into smaller balls. And + + + align:start position:0% +and break them into smaller balls. And +otherwise, if if they're comparable, + + align:start position:0% +otherwise, if if they're comparable, + + + align:start position:0% +otherwise, if if they're comparable, +then we look at at what's happening. + + align:start position:0% + + + + align:start position:0% + +>> Yeah, that's a good question. Yeah. + + align:start position:0% +>> Yeah, that's a good question. Yeah. + + + align:start position:0% +>> Yeah, that's a good question. Yeah. +>> So, I understand uh what's going on. Is + + align:start position:0% +>> So, I understand uh what's going on. Is + + + align:start position:0% +>> So, I understand uh what's going on. Is +this example uh supposed to be similar + + align:start position:0% +this example uh supposed to be similar + + + align:start position:0% +this example uh supposed to be similar +to the case B that we had at the + + align:start position:0% +to the case B that we had at the + + + align:start position:0% +to the case B that we had at the +beginning where like for instance if we + + align:start position:0% +beginning where like for instance if we + + + align:start position:0% +beginning where like for instance if we +started with tubes and points on a + + align:start position:0% +started with tubes and points on a + + + align:start position:0% +started with tubes and points on a +bridge would we kind of immediately fall + + align:start position:0% +bridge would we kind of immediately fall + + + align:start position:0% +bridge would we kind of immediately fall +just into the situation and what we're + + align:start position:0% +just into the situation and what we're + + + align:start position:0% +just into the situation and what we're +doing is blowing things up until we get + + align:start position:0% +doing is blowing things up until we get + + + align:start position:0% +doing is blowing things up until we get +there. + + align:start position:0% +there. + + + align:start position:0% +there. +>> Yeah. Okay. So the question is how how + + align:start position:0% +>> Yeah. Okay. So the question is how how + + + align:start position:0% +>> Yeah. Okay. So the question is how how +these pictures and these examples relate + + align:start position:0% +these pictures and these examples relate + + + align:start position:0% +these pictures and these examples relate +to the the the three examples that we + + align:start position:0% +to the the the three examples that we + + + align:start position:0% +to the the the three examples that we +had in mind at the beginning. Um so the + + align:start position:0% +had in mind at the beginning. Um so the + + + align:start position:0% +had in mind at the beginning. Um so the +three examples we had in mind at the + + align:start position:0% +three examples we had in mind at the + + + align:start position:0% +three examples we had in mind at the +beginning were there was a simple one + + align:start position:0% +beginning were there was a simple one + + + align:start position:0% +beginning were there was a simple one +the stars example there was the grid + + align:start position:0% +the stars example there was the grid + + + align:start position:0% +the stars example there was the grid +that was interesting and there was like + + align:start position:0% +that was interesting and there was like + + + align:start position:0% +that was interesting and there was like +the random example + + align:start position:0% +the random example + + + align:start position:0% +the random example +and a funny thing is that none of those + + align:start position:0% +and a funny thing is that none of those + + + align:start position:0% +and a funny thing is that none of those +is ad regular + + align:start position:0% +is ad regular + + + align:start position:0% +is ad regular +right and now the the the + + align:start position:0% +right and now the the the + + + align:start position:0% +right and now the the the +random one we could fidget to make it ad + + align:start position:0% +random one we could fidget to make it ad + + + align:start position:0% +random one we could fidget to make it ad +regular if we wanted to um and the stars + + align:start position:0% +regular if we wanted to um and the stars + + + align:start position:0% +regular if we wanted to um and the stars +we we could make it ad regular if we + + align:start position:0% +we we could make it ad regular if we + + + align:start position:0% +we we could make it ad regular if we +wanted to but the grid is is actually is + + align:start position:0% +wanted to but the grid is is actually is + + + align:start position:0% +wanted to but the grid is is actually is +really not adular + + align:start position:0% +really not adular + + + align:start position:0% +really not adular +Um and so that is a little bit funny + + align:start position:0% +Um and so that is a little bit funny + + + align:start position:0% +Um and so that is a little bit funny +that in the most important example is + + align:start position:0% +that in the most important example is + + + align:start position:0% +that in the most important example is +not in this case. Um even though this + + align:start position:0% +not in this case. Um even though this + + + align:start position:0% +not in this case. Um even though this +case is very important in the final + + align:start position:0% +case is very important in the final + + + align:start position:0% +case is very important in the final +proof. + + align:start position:0% +proof. + + + align:start position:0% +proof. +Um so you can't really start with the + + align:start position:0% +Um so you can't really start with the + + + align:start position:0% +Um so you can't really start with the +grid + + align:start position:0% +grid + + + align:start position:0% +grid +and it is + + align:start position:0% +and it is + + + align:start position:0% +and it is +not at least until recently it was not + + align:start position:0% +not at least until recently it was not + + + align:start position:0% +not at least until recently it was not +known what is the actual worst behavior + + align:start position:0% +known what is the actual worst behavior + + + align:start position:0% +known what is the actual worst behavior +in the AD regular case. It may be so it + + align:start position:0% +in the AD regular case. It may be so it + + + align:start position:0% +in the AD regular case. It may be so it +may be that RA a is much smaller than R. + + align:start position:0% +may be that RA a is much smaller than R. + + + align:start position:0% +may be that RA a is much smaller than R. +Um uh although but the argument so far + + align:start position:0% +Um uh although but the argument so far + + + align:start position:0% +Um uh although but the argument so far +doesn't prove that and that's a little + + align:start position:0% +doesn't prove that and that's a little + + + align:start position:0% +doesn't prove that and that's a little +it's a little bit funny because it means + + align:start position:0% +it's a little bit funny because it means + + + align:start position:0% +it's a little bit funny because it means +there's not an example that you can keep + + align:start position:0% +there's not an example that you can keep + + + align:start position:0% +there's not an example that you can keep +in mind when you go through the ad + + align:start position:0% +in mind when you go through the ad + + + align:start position:0% +in mind when you go through the ad +regular case. + + align:start position:0% +regular case. + + + align:start position:0% +regular case. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> What what goes wrong with trying to kind + + align:start position:0% +>> What what goes wrong with trying to kind + + + align:start position:0% +>> What what goes wrong with trying to kind +construct an ad regular grid where you + + align:start position:0% +construct an ad regular grid where you + + + align:start position:0% +construct an ad regular grid where you +just kind of have a grid wherein each + + align:start position:0% +just kind of have a grid wherein each + + + align:start position:0% +just kind of have a grid wherein each +point has a lot of sort of nested + + align:start position:0% +point has a lot of sort of nested + + + align:start position:0% +point has a lot of sort of nested +subgrids within it. + + align:start position:0% +subgrids within it. + + + align:start position:0% +subgrids within it. +>> Yeah. So the question is could you make + + align:start position:0% +>> Yeah. So the question is could you make + + + align:start position:0% +>> Yeah. So the question is could you make +an ad? Yeah, I guess that's true. You + + align:start position:0% +an ad? Yeah, I guess that's true. You + + + align:start position:0% +an ad? Yeah, I guess that's true. You +could make a roughly a somewhat ad + + align:start position:0% +could make a roughly a somewhat ad + + + align:start position:0% +could make a roughly a somewhat ad +regular grid by taking a grid of balls + + align:start position:0% +regular grid by taking a grid of balls + + + align:start position:0% +regular grid by taking a grid of balls +and then in each one of those balls you + + align:start position:0% +and then in each one of those balls you + + + align:start position:0% +and then in each one of those balls you +put a grid of balls and you repeat like + + align:start position:0% +put a grid of balls and you repeat like + + + align:start position:0% +put a grid of balls and you repeat like +this. Um uh but it's not since the grid + + align:start position:0% +this. Um uh but it's not since the grid + + + align:start position:0% +this. Um uh but it's not since the grid +itself is not a dregular. This this is + + align:start position:0% +itself is not a dregular. This this is + + + align:start position:0% +itself is not a dregular. This this is +only a it's only a dregular with a big + + align:start position:0% +only a it's only a dregular with a big + + + align:start position:0% +only a it's only a dregular with a big +c. Um could you do that? Yeah, I guess + + align:start position:0% +c. Um could you do that? Yeah, I guess + + + align:start position:0% +c. Um could you do that? Yeah, I guess +you could do that. + + align:start position:0% + + + + align:start position:0% + +Yeah. Yeah. Okay. So you could do that. + + align:start position:0% +Yeah. Yeah. Okay. So you could do that. + + + align:start position:0% +Yeah. Yeah. Okay. So you could do that. +And then what would happen here? The A, + + align:start position:0% +And then what would happen here? The A, + + + align:start position:0% +And then what would happen here? The A, +B and C would be like sets of integers + + align:start position:0% +B and C would be like sets of integers + + + align:start position:0% +B and C would be like sets of integers +except they would have this ad regular + + align:start position:0% +except they would have this ad regular + + + align:start position:0% +except they would have this ad regular +structure. So A would be like take an + + align:start position:0% +structure. So A would be like take an + + + align:start position:0% +structure. So A would be like take an +arithmetic progression of intervals and + + align:start position:0% +arithmetic progression of intervals and + + + align:start position:0% +arithmetic progression of intervals and +in each one of them put an arithmetic + + align:start position:0% +in each one of them put an arithmetic + + + align:start position:0% +in each one of them put an arithmetic +progression of smaller intervals and so + + align:start position:0% +progression of smaller intervals and so + + + align:start position:0% +progression of smaller intervals and so +on. That's what A and B and C would look + + align:start position:0% +on. That's what A and B and C would look + + + align:start position:0% +on. That's what A and B and C would look +like. + + align:start position:0% +like. + + + align:start position:0% +like. +>> Can you cancept them? + + align:start position:0% +>> Can you cancept them? + + + align:start position:0% +>> Can you cancept them? +>> Yeah, it's kind of like a caner. It's + + align:start position:0% +>> Yeah, it's kind of like a caner. It's + + + align:start position:0% +>> Yeah, it's kind of like a caner. It's +like a counter set but the but with but + + align:start position:0% +like a counter set but the but with but + + + align:start position:0% +like a counter set but the but with but +in order to make it make the numbers + + align:start position:0% +in order to make it make the numbers + + + align:start position:0% +in order to make it make the numbers +come out well you you need to have a lot + + align:start position:0% +come out well you you need to have a lot + + + align:start position:0% +come out well you you need to have a lot +of intervals in an arithmetic + + align:start position:0% +of intervals in an arithmetic + + + align:start position:0% +of intervals in an arithmetic +progression in each step. Here I'll draw + + align:start position:0% +progression in each step. Here I'll draw + + + align:start position:0% +progression in each step. Here I'll draw +it and then I'm over so I'm going to + + align:start position:0% +it and then I'm over so I'm going to + + + align:start position:0% +it and then I'm over so I'm going to +stop. + + align:start position:0% +stop. + + + align:start position:0% +stop. +So the example is um for a big line you + + align:start position:0% +So the example is um for a big line you + + + align:start position:0% +So the example is um for a big line you +make an arithmetic progression with a + + align:start position:0% +make an arithmetic progression with a + + + align:start position:0% +make an arithmetic progression with a +lot of intervals. + + align:start position:0% + + + + align:start position:0% + +Okay? Then you look inside of each one + + align:start position:0% +Okay? Then you look inside of each one + + + align:start position:0% +Okay? Then you look inside of each one +of these intervals and you repeat what I + + align:start position:0% +of these intervals and you repeat what I + + + align:start position:0% +of these intervals and you repeat what I +just did. Um and for for this to for + + align:start position:0% +just did. Um and for for this to for + + + align:start position:0% +just did. Um and for for this to for +this to be a kind of sharp interesting + + align:start position:0% +this to be a kind of sharp interesting + + + align:start position:0% +this to be a kind of sharp interesting +example, it needs to be a lot of + + align:start position:0% +example, it needs to be a lot of + + + align:start position:0% +example, it needs to be a lot of +intervals. + + align:start position:0% +intervals. + + + align:start position:0% +intervals. +Okay. Okay. Good. Sorry for going a + + align:start position:0% +Okay. Okay. Good. Sorry for going a + + + align:start position:0% +Okay. Okay. Good. Sorry for going a +little bit over. Um, those are great + + align:start position:0% +little bit over. Um, those are great + + + align:start position:0% +little bit over. Um, those are great +questions. Let's stop there and I will + + align:start position:0% +questions. Let's stop there and I will + + + align:start position:0% +questions. Let's stop there and I will +see you next week. \ No newline at end of file diff --git a/IC-pnm6PEGk.txt b/IC-pnm6PEGk.txt new file mode 100644 index 0000000000000000000000000000000000000000..90a4ab9262441f9818ee5da673220242935cc683 --- /dev/null +++ b/IC-pnm6PEGk.txt @@ -0,0 +1,1531 @@ +align:start position:0% + +we will now apply our multinomial + + align:start position:0% +we will now apply our multinomial + + + align:start position:0% +we will now apply our multinomial +formula for counting the number of + + align:start position:0% +formula for counting the number of + + + align:start position:0% +formula for counting the number of +partitions to solve the following + + align:start position:0% +partitions to solve the following + + + align:start position:0% +partitions to solve the following +probability problem we have a standard + + align:start position:0% +probability problem we have a standard + + + align:start position:0% +probability problem we have a standard +52-card deck which we deal to four + + align:start position:0% +52-card deck which we deal to four + + + align:start position:0% +52-card deck which we deal to four +persons each person gets 13 cards as for + + align:start position:0% +persons each person gets 13 cards as for + + + align:start position:0% +persons each person gets 13 cards as for +example in bridge what is the + + align:start position:0% +example in bridge what is the + + + align:start position:0% +example in bridge what is the +probability that each person gets + + align:start position:0% +probability that each person gets + + + align:start position:0% +probability that each person gets +exactly one ace well before we start as + + align:start position:0% +exactly one ace well before we start as + + + align:start position:0% +exactly one ace well before we start as +always we will need a probability model + + align:start position:0% +always we will need a probability model + + + align:start position:0% +always we will need a probability model +we deal the cards + + align:start position:0% +we deal the cards + + + align:start position:0% +we deal the cards +fairly and this is going to be our model + + align:start position:0% +fairly and this is going to be our model + + + align:start position:0% +fairly and this is going to be our model +but we still need to interpret our + + align:start position:0% +but we still need to interpret our + + + align:start position:0% +but we still need to interpret our +statements to give this interpretation + + align:start position:0% +statements to give this interpretation + + + align:start position:0% +statements to give this interpretation +let us first think of the outcomes of + + align:start position:0% +let us first think of the outcomes of + + + align:start position:0% +let us first think of the outcomes of +the experiment what are the possible + + align:start position:0% +the experiment what are the possible + + + align:start position:0% +the experiment what are the possible +outcomes and outcome of this experiment + + align:start position:0% +outcomes and outcome of this experiment + + + align:start position:0% +outcomes and outcome of this experiment +is a partition of the fifty-two cards + + align:start position:0% +is a partition of the fifty-two cards + + + align:start position:0% +is a partition of the fifty-two cards +into the four persons so that each + + align:start position:0% +into the four persons so that each + + + align:start position:0% +into the four persons so that each +person gets exactly 13 cards our + + align:start position:0% +person gets exactly 13 cards our + + + align:start position:0% +person gets exactly 13 cards our +statement about dealing the cards fairly + + align:start position:0% +statement about dealing the cards fairly + + + align:start position:0% +statement about dealing the cards fairly +will be an assumption that all + + align:start position:0% +will be an assumption that all + + + align:start position:0% +will be an assumption that all +partitions are equally likely + + align:start position:0% + + + + align:start position:0% + +okay so since all partitions all + + align:start position:0% +okay so since all partitions all + + + align:start position:0% +okay so since all partitions all +outcomes of the experiment are equally + + align:start position:0% +outcomes of the experiment are equally + + + align:start position:0% +outcomes of the experiment are equally +likely this means that we can solve a + + align:start position:0% +likely this means that we can solve a + + + align:start position:0% +likely this means that we can solve a +probability question by Counting we need + + align:start position:0% +probability question by Counting we need + + + align:start position:0% +probability question by Counting we need +to count the number of elements of our + + align:start position:0% +to count the number of elements of our + + + align:start position:0% +to count the number of elements of our +sample space the number of possible + + align:start position:0% +sample space the number of possible + + + align:start position:0% +sample space the number of possible +outcomes and then count the number of + + align:start position:0% +outcomes and then count the number of + + + align:start position:0% +outcomes and then count the number of +outcomes that make the event of interest + + align:start position:0% +outcomes that make the event of interest + + + align:start position:0% +outcomes that make the event of interest +to occur let us start with the number of + + align:start position:0% +to occur let us start with the number of + + + align:start position:0% +to occur let us start with the number of +elements of the sample space this is the + + align:start position:0% +elements of the sample space this is the + + + align:start position:0% +elements of the sample space this is the +problem that we just dealt with a little + + align:start position:0% +problem that we just dealt with a little + + + align:start position:0% +problem that we just dealt with a little +while ago the number of outcomes the + + align:start position:0% +while ago the number of outcomes the + + + align:start position:0% +while ago the number of outcomes the +number of partitions of 52 items by into + + align:start position:0% +number of partitions of 52 items by into + + + align:start position:0% +number of partitions of 52 items by into +four persons where we give thirteen + + align:start position:0% +four persons where we give thirteen + + + align:start position:0% +four persons where we give thirteen +cards to person one thirteen cards to + + align:start position:0% +cards to person one thirteen cards to + + + align:start position:0% +cards to person one thirteen cards to +person two thirteen cards to person + + align:start position:0% +person two thirteen cards to person + + + align:start position:0% +person two thirteen cards to person +three and thirteen cards to person for + + align:start position:0% +three and thirteen cards to person for + + + align:start position:0% +three and thirteen cards to person for +the number of possible ways of doing + + align:start position:0% +the number of possible ways of doing + + + align:start position:0% +the number of possible ways of doing +this is equal to this multinomial + + align:start position:0% +this is equal to this multinomial + + + align:start position:0% +this is equal to this multinomial +coefficient so now let us count the + + align:start position:0% +coefficient so now let us count the + + + align:start position:0% +coefficient so now let us count the +number of outcomes that belong to the + + align:start position:0% +number of outcomes that belong to the + + + align:start position:0% +number of outcomes that belong to the +event of interest namely the outcomes + + align:start position:0% +event of interest namely the outcomes + + + align:start position:0% +event of interest namely the outcomes +were where each person gets an ace we + + align:start position:0% +were where each person gets an ace we + + + align:start position:0% +were where each person gets an ace we +think of the process of constructing + + align:start position:0% +think of the process of constructing + + + align:start position:0% +think of the process of constructing +such an outcome as a multi-stage process + + align:start position:0% +such an outcome as a multi-stage process + + + align:start position:0% +such an outcome as a multi-stage process +and we count the number of choices that + + align:start position:0% +and we count the number of choices that + + + align:start position:0% +and we count the number of choices that +we have at each stage the process is as + + align:start position:0% +we have at each stage the process is as + + + align:start position:0% +we have at each stage the process is as +follows we first distribute the four + + align:start position:0% +follows we first distribute the four + + + align:start position:0% +follows we first distribute the four +aces we take the ace of spades and give + + align:start position:0% +aces we take the ace of spades and give + + + align:start position:0% +aces we take the ace of spades and give +it to one person in how many ways can we + + align:start position:0% +it to one person in how many ways can we + + + align:start position:0% +it to one person in how many ways can we +do it we can do it in four ways then we + + align:start position:0% +do it we can do it in four ways then we + + + align:start position:0% +do it we can do it in four ways then we +take the next ace the next ace must be + + align:start position:0% +take the next ace the next ace must be + + + align:start position:0% +take the next ace the next ace must be +given to a different person and so at + + align:start position:0% +given to a different person and so at + + + align:start position:0% +given to a different person and so at +that stage we have three different + + align:start position:0% +that stage we have three different + + + align:start position:0% +that stage we have three different +choices about whom to give that ace to + + align:start position:0% +choices about whom to give that ace to + + + align:start position:0% +choices about whom to give that ace to +then we consider the next ace at this + + align:start position:0% +then we consider the next ace at this + + + align:start position:0% +then we consider the next ace at this +point two persons already have aces so + + align:start position:0% +point two persons already have aces so + + + align:start position:0% +point two persons already have aces so +we have two available choices for who + + align:start position:0% +we have two available choices for who + + + align:start position:0% +we have two available choices for who +can get the next ace and finally for the + + align:start position:0% +can get the next ace and finally for the + + + align:start position:0% +can get the next ace and finally for the +last ace we do not have any choice we + + align:start position:0% +last ace we do not have any choice we + + + align:start position:0% +last ace we do not have any choice we +give it to the only remaining person who + + align:start position:0% +give it to the only remaining person who + + + align:start position:0% +give it to the only remaining person who +doesn't yet have an ace having + + align:start position:0% +doesn't yet have an ace having + + + align:start position:0% +doesn't yet have an ace having +distributed the four aces then we need + + align:start position:0% +distributed the four aces then we need + + + align:start position:0% +distributed the four aces then we need +to somehow distribute the remaining 48 + + align:start position:0% +to somehow distribute the remaining 48 + + + align:start position:0% +to somehow distribute the remaining 48 +cards to the four people but we can do + + align:start position:0% +cards to the four people but we can do + + + align:start position:0% +cards to the four people but we can do +that in any way we want + + align:start position:0% +that in any way we want + + + align:start position:0% +that in any way we want +so all we need to do is to + + align:start position:0% +so all we need to do is to + + + align:start position:0% +so all we need to do is to +partition the 48 cards into four subsets + + align:start position:0% +partition the 48 cards into four subsets + + + align:start position:0% +partition the 48 cards into four subsets +of given cardinalities and this can done + + align:start position:0% +of given cardinalities and this can done + + + align:start position:0% +of given cardinalities and this can done +by a number of ways which is the number + + align:start position:0% +by a number of ways which is the number + + + align:start position:0% +by a number of ways which is the number +of such partitions we have already found + + align:start position:0% +of such partitions we have already found + + + align:start position:0% +of such partitions we have already found +what that number is and it is this + + align:start position:0% +what that number is and it is this + + + align:start position:0% +what that number is and it is this +particular multinomial coefficient so + + align:start position:0% +particular multinomial coefficient so + + + align:start position:0% +particular multinomial coefficient so +the number of ways that we can + + align:start position:0% +the number of ways that we can + + + align:start position:0% +the number of ways that we can +distribute the cards so that each person + + align:start position:0% +distribute the cards so that each person + + + align:start position:0% +distribute the cards so that each person +gets an A is according to the counting + + align:start position:0% +gets an A is according to the counting + + + align:start position:0% +gets an A is according to the counting +principle is going to be the number of + + align:start position:0% +principle is going to be the number of + + + align:start position:0% +principle is going to be the number of +ways that we can distribute the aces + + align:start position:0% +ways that we can distribute the aces + + + align:start position:0% +ways that we can distribute the aces +times the number of ways that we can + + align:start position:0% +times the number of ways that we can + + + align:start position:0% +times the number of ways that we can +distribute the remaining cards the + + align:start position:0% +distribute the remaining cards the + + + align:start position:0% +distribute the remaining cards the +product of this number gives us the + + align:start position:0% +product of this number gives us the + + + align:start position:0% +product of this number gives us the +count gives us the cardinality of the + + align:start position:0% +count gives us the cardinality of the + + + align:start position:0% +count gives us the cardinality of the +event of interest we also have the + + align:start position:0% +event of interest we also have the + + + align:start position:0% +event of interest we also have the +cardinality of the sample space so the + + align:start position:0% +cardinality of the sample space so the + + + align:start position:0% +cardinality of the sample space so the +desired probability can be found by + + align:start position:0% +desired probability can be found by + + + align:start position:0% +desired probability can be found by +dividing these two numbers and the final + + align:start position:0% +dividing these two numbers and the final + + + align:start position:0% +dividing these two numbers and the final +answer takes this form let us now look + + align:start position:0% +answer takes this form let us now look + + + align:start position:0% +answer takes this form let us now look +at the same problem but in a different + + align:start position:0% +at the same problem but in a different + + + align:start position:0% +at the same problem but in a different +way + + align:start position:0% +way + + + align:start position:0% +way +probability problems can often be solved + + align:start position:0% +probability problems can often be solved + + + align:start position:0% +probability problems can often be solved +in multiple ways and some can be faster + + align:start position:0% +in multiple ways and some can be faster + + + align:start position:0% +in multiple ways and some can be faster +than others so we want to look for a + + align:start position:0% +than others so we want to look for a + + + align:start position:0% +than others so we want to look for a +smarter solution that perhaps will get + + align:start position:0% +smarter solution that perhaps will get + + + align:start position:0% +smarter solution that perhaps will get +us in a faster way to the desired answer + + align:start position:0% +us in a faster way to the desired answer + + + align:start position:0% +us in a faster way to the desired answer +we will use the following trick we will + + align:start position:0% +we will use the following trick we will + + + align:start position:0% +we will use the following trick we will +think about a very specific way of + + align:start position:0% +think about a very specific way of + + + align:start position:0% +think about a very specific way of +dealing the currents which is the + + align:start position:0% +dealing the currents which is the + + + align:start position:0% +dealing the currents which is the +following we take the 52 cards the card + + align:start position:0% +following we take the 52 cards the card + + + align:start position:0% +following we take the 52 cards the card +deck and stack it so that the four aces + + align:start position:0% +deck and stack it so that the four aces + + + align:start position:0% +deck and stack it so that the four aces +are at the top so they are first and + + align:start position:0% +are at the top so they are first and + + + align:start position:0% +are at the top so they are first and +then we deal those cards to the players + + align:start position:0% +then we deal those cards to the players + + + align:start position:0% +then we deal those cards to the players +as follows we think of each player + + align:start position:0% +as follows we think of each player + + + align:start position:0% +as follows we think of each player +having 13 slots of his own and the cards + + align:start position:0% +having 13 slots of his own and the cards + + + align:start position:0% +having 13 slots of his own and the cards +will be placed randomly into the + + align:start position:0% +will be placed randomly into the + + + align:start position:0% +will be placed randomly into the +different slots so we can do this one + + align:start position:0% +different slots so we can do this one + + + align:start position:0% +different slots so we can do this one +card at a time starting from the top we + + align:start position:0% +card at a time starting from the top we + + + align:start position:0% +card at a time starting from the top we +take the first ace and send it to a + + align:start position:0% +take the first ace and send it to a + + + align:start position:0% +take the first ace and send it to a +random location then we will take the + + align:start position:0% +random location then we will take the + + + align:start position:0% +random location then we will take the +second ace and it to a random location + + align:start position:0% +second ace and it to a random location + + + align:start position:0% +second ace and it to a random location +and so on what we want to calculate + + align:start position:0% +and so on what we want to calculate + + + align:start position:0% +and so on what we want to calculate +is the probability that the four aces we + + align:start position:0% +is the probability that the four aces we + + + align:start position:0% +is the probability that the four aces we +end up in locations or in slots that are + + align:start position:0% +end up in locations or in slots that are + + + align:start position:0% +end up in locations or in slots that are +associated with different persons so let + + align:start position:0% +associated with different persons so let + + + align:start position:0% +associated with different persons so let +us calculate this probability the first + + align:start position:0% +us calculate this probability the first + + + align:start position:0% +us calculate this probability the first +ace can go anywhere it doesn't matter + + align:start position:0% +ace can go anywhere it doesn't matter + + + align:start position:0% +ace can go anywhere it doesn't matter +for the second ace it has 51 slots to + + align:start position:0% +for the second ace it has 51 slots to + + + align:start position:0% +for the second ace it has 51 slots to +choose from it's 51 because we started + + align:start position:0% +choose from it's 51 because we started + + + align:start position:0% +choose from it's 51 because we started +with 52 but one slot has already been + + align:start position:0% +with 52 but one slot has already been + + + align:start position:0% +with 52 but one slot has already been +taken by that particular ace so for the + + align:start position:0% +taken by that particular ace so for the + + + align:start position:0% +taken by that particular ace so for the +ace of hearts we have 51 slots that it + + align:start position:0% +ace of hearts we have 51 slots that it + + + align:start position:0% +ace of hearts we have 51 slots that it +can go to and out of those 51 we have 39 + + align:start position:0% +can go to and out of those 51 we have 39 + + + align:start position:0% +can go to and out of those 51 we have 39 +of them that belong to people who do not + + align:start position:0% +of them that belong to people who do not + + + align:start position:0% +of them that belong to people who do not +yet have an ace so this is the + + align:start position:0% +yet have an ace so this is the + + + align:start position:0% +yet have an ace so this is the +probability that the ace of hearts gets + + align:start position:0% +probability that the ace of hearts gets + + + align:start position:0% +probability that the ace of hearts gets +placed into a slot that belongs to a + + align:start position:0% +placed into a slot that belongs to a + + + align:start position:0% +placed into a slot that belongs to a +person who is different than the person + + align:start position:0% +person who is different than the person + + + align:start position:0% +person who is different than the person +who got the second the first ace now let + + align:start position:0% +who got the second the first ace now let + + + align:start position:0% +who got the second the first ace now let +us consider this ace what is the + + align:start position:0% +us consider this ace what is the + + + align:start position:0% +us consider this ace what is the +probability that this ace will get into + + align:start position:0% +probability that this ace will get into + + + align:start position:0% +probability that this ace will get into +a slot which belongs to either this + + align:start position:0% +a slot which belongs to either this + + + align:start position:0% +a slot which belongs to either this +person or that person it has 26 slots in + + align:start position:0% +person or that person it has 26 slots in + + + align:start position:0% +person or that person it has 26 slots in +which this desired event is going to + + align:start position:0% +which this desired event is going to + + + align:start position:0% +which this desired event is going to +happen and it's 26 out of the 50 + + align:start position:0% +happen and it's 26 out of the 50 + + + align:start position:0% +happen and it's 26 out of the 50 +available slots finally let us consider + + align:start position:0% +available slots finally let us consider + + + align:start position:0% +available slots finally let us consider +this ace so having placed that ace and + + align:start position:0% +this ace so having placed that ace and + + + align:start position:0% +this ace so having placed that ace and +assuming that it goes to a different + + align:start position:0% +assuming that it goes to a different + + + align:start position:0% +assuming that it goes to a different +person what is the probability now that + + align:start position:0% +person what is the probability now that + + + align:start position:0% +person what is the probability now that +this ace is going to go to this person + + align:start position:0% +this ace is going to go to this person + + + align:start position:0% +this ace is going to go to this person +who doesn't yet have one the probability + + align:start position:0% +who doesn't yet have one the probability + + + align:start position:0% +who doesn't yet have one the probability +of this happening is the number of slots + + align:start position:0% +of this happening is the number of slots + + + align:start position:0% +of this happening is the number of slots +associated with that person which is + + align:start position:0% +associated with that person which is + + + align:start position:0% +associated with that person which is +equal to 13 divided by the number of + + align:start position:0% +equal to 13 divided by the number of + + + align:start position:0% +equal to 13 divided by the number of +slots that this card can choose from and + + align:start position:0% +slots that this card can choose from and + + + align:start position:0% +slots that this card can choose from and +the number of slots is 52 - the three + + align:start position:0% +the number of slots is 52 - the three + + + align:start position:0% +the number of slots is 52 - the three +slots that have already been taken + + align:start position:0% +slots that have already been taken + + + align:start position:0% +slots that have already been taken +so it's 49 and so this is the answer to + + align:start position:0% +so it's 49 and so this is the answer to + + + align:start position:0% +so it's 49 and so this is the answer to +our problem this expression looks very + + align:start position:0% +our problem this expression looks very + + + align:start position:0% +our problem this expression looks very +different from the expression that we + + align:start position:0% +different from the expression that we + + + align:start position:0% +different from the expression that we +derived a little earlier but you can do + + align:start position:0% +derived a little earlier but you can do + + + align:start position:0% +derived a little earlier but you can do +the algebra the arithmetic simplify the + + align:start position:0% +the algebra the arithmetic simplify the + + + align:start position:0% +the algebra the arithmetic simplify the +answer and you will + + align:start position:0% +answer and you will + + + align:start position:0% +answer and you will +verify that indeed it's exactly the same + + align:start position:0% +verify that indeed it's exactly the same + + + align:start position:0% +verify that indeed it's exactly the same +answer and case you're curious the + + align:start position:0% +answer and case you're curious the + + + align:start position:0% +answer and case you're curious the +numerical value turns out to be point + + align:start position:0% +numerical value turns out to be point + + + align:start position:0% +numerical value turns out to be point +105 so there is about 10% that when you + + align:start position:0% +105 so there is about 10% that when you + + + align:start position:0% +105 so there is about 10% that when you +deal the cards in bridge each one of the + + align:start position:0% +deal the cards in bridge each one of the + + + align:start position:0% +deal the cards in bridge each one of the +players is going to end up by half + + align:start position:0% +players is going to end up by half + + + align:start position:0% +players is going to end up by half +having exactly one ace so this was a + + align:start position:0% +having exactly one ace so this was a + + + align:start position:0% +having exactly one ace so this was a +faster way of getting to the answer to + + align:start position:0% +faster way of getting to the answer to + + + align:start position:0% +faster way of getting to the answer to +our problem compared to the previous one + + align:start position:0% +our problem compared to the previous one + + + align:start position:0% +our problem compared to the previous one +but it raises a legitimate question is + + align:start position:0% +but it raises a legitimate question is + + + align:start position:0% +but it raises a legitimate question is +the way that we dealt the cards by + + align:start position:0% +the way that we dealt the cards by + + + align:start position:0% +the way that we dealt the cards by +putting the aces on top and then dealing + + align:start position:0% +putting the aces on top and then dealing + + + align:start position:0% +putting the aces on top and then dealing +them is that way a fair way of dealing + + align:start position:0% +them is that way a fair way of dealing + + + align:start position:0% +them is that way a fair way of dealing +the cards is it true that with this way + + align:start position:0% +the cards is it true that with this way + + + align:start position:0% +the cards is it true that with this way +of dealing the cards all partitions are + + align:start position:0% +of dealing the cards all partitions are + + + align:start position:0% +of dealing the cards all partitions are +equally likely it turns out that this is + + align:start position:0% +equally likely it turns out that this is + + + align:start position:0% +equally likely it turns out that this is +indeed the case but it does require a + + align:start position:0% +indeed the case but it does require a + + + align:start position:0% +indeed the case but it does require a +bit of thinking maybe you can see it + + align:start position:0% +bit of thinking maybe you can see it + + + align:start position:0% +bit of thinking maybe you can see it +intuitively that this is the case but if + + align:start position:0% +intuitively that this is the case but if + + + align:start position:0% +intuitively that this is the case but if +not then it is something that one can + + align:start position:0% +not then it is something that one can + + + align:start position:0% +not then it is something that one can +prove it can be proved formally as + + align:start position:0% +prove it can be proved formally as + + + align:start position:0% +prove it can be proved formally as +follows one first needs to check that + + align:start position:0% +follows one first needs to check that + + + align:start position:0% +follows one first needs to check that +all permutations that is all possible + + align:start position:0% +all permutations that is all possible + + + align:start position:0% +all permutations that is all possible +allocations of cards into slots are + + align:start position:0% +allocations of cards into slots are + + + align:start position:0% +allocations of cards into slots are +equally likely and because of this one + + align:start position:0% +equally likely and because of this one + + + align:start position:0% +equally likely and because of this one +can then argue that any possible + + align:start position:0% +can then argue that any possible + + + align:start position:0% +can then argue that any possible +partition in two subsets of 12 is also + + align:start position:0% +partition in two subsets of 12 is also + + + align:start position:0% +partition in two subsets of 12 is also +equally likely so this is an equivalent + + align:start position:0% +equally likely so this is an equivalent + + + align:start position:0% +equally likely so this is an equivalent +way of dealing the cards to the one that + + align:start position:0% +way of dealing the cards to the one that + + + align:start position:0% +way of dealing the cards to the one that +we considered earlier which was that + + align:start position:0% +we considered earlier which was that + + + align:start position:0% +we considered earlier which was that +every partition is equally likely + + align:start position:0% +every partition is equally likely + + + align:start position:0% +every partition is equally likely +therefore we did indeed solve the same + + align:start position:0% +therefore we did indeed solve the same + + + align:start position:0% +therefore we did indeed solve the same +problem and so this is a legitimate + + align:start position:0% +problem and so this is a legitimate + + + align:start position:0% +problem and so this is a legitimate +alternative way of getting to the answer + + align:start position:0% +alternative way of getting to the answer + + + align:start position:0% +alternative way of getting to the answer +and of course it's reassuring to check + + align:start position:0% +and of course it's reassuring to check + + + align:start position:0% +and of course it's reassuring to check +that this numerical expression agrees + + align:start position:0% +that this numerical expression agrees + + + align:start position:0% +that this numerical expression agrees +with a numerical expression we had + + align:start position:0% +with a numerical expression we had + + + align:start position:0% +with a numerical expression we had +derived earlier \ No newline at end of file diff --git a/IXwPD4R6V6M.txt b/IXwPD4R6V6M.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d64f8bbb6f82bbec8d3a8292e2d2f25b76d036c --- /dev/null +++ b/IXwPD4R6V6M.txt @@ -0,0 +1,899 @@ +align:start position:0% + +okay so now we know what CP is we can go + + align:start position:0% +okay so now we know what CP is we can go + + + align:start position:0% +okay so now we know what CP is we can go +ahead and build one last tree using + + align:start position:0% +ahead and build one last tree using + + + align:start position:0% +ahead and build one last tree using +cross-validation so we need to make sure + + align:start position:0% +cross-validation so we need to make sure + + + align:start position:0% +cross-validation so we need to make sure +that we have the required libraries and + + align:start position:0% +that we have the required libraries and + + + align:start position:0% +that we have the required libraries and +install and use so those packages the + + align:start position:0% +install and use so those packages the + + + align:start position:0% +install and use so those packages the +carrot package and secondly we need this + + align:start position:0% +carrot package and secondly we need this + + + align:start position:0% +carrot package and secondly we need this +e 107 1 package okay so we need to tell + + align:start position:0% +e 107 1 package okay so we need to tell + + + align:start position:0% +e 107 1 package okay so we need to tell +the carrot package how is that clear we + + align:start position:0% +the carrot package how is that clear we + + + align:start position:0% +the carrot package how is that clear we +want to do our parameter tuning there + + align:start position:0% +want to do our parameter tuning there + + + align:start position:0% +want to do our parameter tuning there +are actually quite a few ways of doing + + align:start position:0% +are actually quite a few ways of doing + + + align:start position:0% +are actually quite a few ways of doing +it but we're gonna restrict ourselves in + + align:start position:0% +it but we're gonna restrict ourselves in + + + align:start position:0% +it but we're gonna restrict ourselves in +this course to just 10-fold + + align:start position:0% +this course to just 10-fold + + + align:start position:0% +this course to just 10-fold +cross-validation as was explained in the + + align:start position:0% +cross-validation as was explained in the + + + align:start position:0% +cross-validation as was explained in the +literature so let's say train troll is + + align:start position:0% +literature so let's say train troll is + + + align:start position:0% +literature so let's say train troll is +Sue's method cross-validation and to use + + align:start position:0% +Sue's method cross-validation and to use + + + align:start position:0% +Sue's method cross-validation and to use +in folks okay that was easy now + + align:start position:0% +in folks okay that was easy now + + + align:start position:0% +in folks okay that was easy now +now we need to tell carrot which range + + align:start position:0% +now we need to tell carrot which range + + + align:start position:0% +now we need to tell carrot which range +of CP parameters to try out now remember + + align:start position:0% +of CP parameters to try out now remember + + + align:start position:0% +of CP parameters to try out now remember +that CP varies between 0 and 1 it's + + align:start position:0% +that CP varies between 0 and 1 it's + + + align:start position:0% +that CP varies between 0 and 1 it's +likely that for any given problem we + + align:start position:0% +likely that for any given problem we + + + align:start position:0% +likely that for any given problem we +don't need to explore the full range I + + align:start position:0% +don't need to explore the full range I + + + align:start position:0% +don't need to explore the full range I +happen to know by the fact that made + + align:start position:0% +happen to know by the fact that made + + + align:start position:0% +happen to know by the fact that made +this recitation here time that the value + + align:start position:0% +this recitation here time that the value + + + align:start position:0% +this recitation here time that the value +of CP we're gonna pick who's very small + + align:start position:0% +of CP we're gonna pick who's very small + + + align:start position:0% +of CP we're gonna pick who's very small +so what I want to do is make a grid of + + align:start position:0% +so what I want to do is make a grid of + + + align:start position:0% +so what I want to do is make a grid of +CP values to try then we'll be over the + + align:start position:0% +CP values to try then we'll be over the + + + align:start position:0% +CP values to try then we'll be over the +range + + align:start position:0% + + + + align:start position:0% + +of zero + + align:start position:0% +of zero + + + align:start position:0% +of zero +oops zero to 0.01 okay so how does what + + align:start position:0% +oops zero to 0.01 okay so how does what + + + align:start position:0% +oops zero to 0.01 okay so how does what +I Roach think to that well 1 times 0.01 + + align:start position:0% +I Roach think to that well 1 times 0.01 + + + align:start position:0% +I Roach think to that well 1 times 0.01 +is obviously zero point zero zero one + + align:start position:0% +is obviously zero point zero zero one + + + align:start position:0% +is obviously zero point zero zero one +and ten times 0.001 is obviously zero + + align:start position:0% +and ten times 0.001 is obviously zero + + + align:start position:0% +and ten times 0.001 is obviously zero +point zero one zero two five zero to ten + + align:start position:0% +point zero one zero two five zero to ten + + + align:start position:0% +point zero one zero two five zero to ten +means the numbers zero one two three + + align:start position:0% +means the numbers zero one two three + + + align:start position:0% +means the numbers zero one two three +four five six seven eight nine ten + + align:start position:0% +four five six seven eight nine ten + + + align:start position:0% +four five six seven eight nine ten +so zero to ten times 0.001 is those + + align:start position:0% +so zero to ten times 0.001 is those + + + align:start position:0% +so zero to ten times 0.001 is those +numbers scale it by 0.001 suppose my + + align:start position:0% +numbers scale it by 0.001 suppose my + + + align:start position:0% +numbers scale it by 0.001 suppose my +values of CP that carrot will try so + + align:start position:0% +values of CP that carrot will try so + + + align:start position:0% +values of CP that carrot will try so +let's stole the results of the + + align:start position:0% +let's stole the results of the + + + align:start position:0% +let's stole the results of the +cross-validation fitting in a very local + + align:start position:0% +cross-validation fitting in a very local + + + align:start position:0% +cross-validation fitting in a very local +truck and we'll use a train function + + align:start position:0% +truck and we'll use a train function + + + align:start position:0% +truck and we'll use a train function +predicting with V based on lat/long + + align:start position:0% +predicting with V based on lat/long + + + align:start position:0% +predicting with V based on lat/long +crime starting industry charles river + + align:start position:0% +crime starting industry charles river + + + align:start position:0% +crime starting industry charles river +pollution rooms age distance distance + + align:start position:0% +pollution rooms age distance distance + + + align:start position:0% +pollution rooms age distance distance +from highways tax + + align:start position:0% +from highways tax + + + align:start position:0% +from highways tax +and people teacher ratio okay + + align:start position:0% +and people teacher ratio okay + + + align:start position:0% +and people teacher ratio okay +we're using the training days we're + + align:start position:0% +we're using the training days we're + + + align:start position:0% +we're using the training days we're +using trees haha how train control is + + align:start position:0% +using trees haha how train control is + + + align:start position:0% +using trees haha how train control is +what we just made before and shooting + + align:start position:0% +what we just made before and shooting + + + align:start position:0% +what we just made before and shooting +fruit is the other thing we just made + + align:start position:0% +fruit is the other thing we just made + + + align:start position:0% +fruit is the other thing we just made +which we called steeply throughs and it + + align:start position:0% +which we called steeply throughs and it + + + align:start position:0% +which we called steeply throughs and it +was a way and what it's doing there is + + align:start position:0% +was a way and what it's doing there is + + + align:start position:0% +was a way and what it's doing there is +it's trying all different values of CP + + align:start position:0% +it's trying all different values of CP + + + align:start position:0% +it's trying all different values of CP +that we asked it to so we can see what + + align:start position:0% +that we asked it to so we can see what + + + align:start position:0% +that we asked it to so we can see what +is done by typing Tia did you can see it + + align:start position:0% +is done by typing Tia did you can see it + + + align:start position:0% +is done by typing Tia did you can see it +tried Tim that 11 who values of CP and + + align:start position:0% +tried Tim that 11 who values of CP and + + + align:start position:0% +tried Tim that 11 who values of CP and +they decided that CP equals 0.001 was + + align:start position:0% +they decided that CP equals 0.001 was + + + align:start position:0% +they decided that CP equals 0.001 was +the best because I had the best rmsd + + align:start position:0% +the best because I had the best rmsd + + + align:start position:0% +the best because I had the best rmsd +root mean square error and it was 5.03 + + align:start position:0% +root mean square error and it was 5.03 + + + align:start position:0% +root mean square error and it was 5.03 +of 0.001 you can see that it's pretty + + align:start position:0% +of 0.001 you can see that it's pretty + + + align:start position:0% +of 0.001 you can see that it's pretty +insensitive to tickle value of cv a CP + + align:start position:0% +insensitive to tickle value of cv a CP + + + align:start position:0% +insensitive to tickle value of cv a CP +so it's maybe not too important + + align:start position:0% +so it's maybe not too important + + + align:start position:0% +so it's maybe not too important +it's interesting though that the numbers + + align:start position:0% +it's interesting though that the numbers + + + align:start position:0% +it's interesting though that the numbers +are so low I tried it for a much larger + + align:start position:0% +are so low I tried it for a much larger + + + align:start position:0% +are so low I tried it for a much larger +range of CP values and it is the best + + align:start position:0% +range of CP values and it is the best + + + align:start position:0% +range of CP values and it is the best +solutions are always very close to 0 so + + align:start position:0% +solutions are always very close to 0 so + + + align:start position:0% +solutions are always very close to 0 so +it wants us to build a very detailed a + + align:start position:0% +it wants us to build a very detailed a + + + align:start position:0% +it wants us to build a very detailed a +rich tree so let's let's see what the + + align:start position:0% +rich tree so let's let's see what the + + + align:start position:0% +rich tree so let's let's see what the +tree that that value of CP corresponds + + align:start position:0% +tree that that value of CP corresponds + + + align:start position:0% +tree that that value of CP corresponds +to is so we can get that from + + align:start position:0% +to is so we can get that from + + + align:start position:0% +to is so we can get that from +during Tia we have to say base tree is T + + align:start position:0% +during Tia we have to say base tree is T + + + align:start position:0% +during Tia we have to say base tree is T +as the train functions final model and + + align:start position:0% +as the train functions final model and + + + align:start position:0% +as the train functions final model and +we can plot that tree so that's the + + align:start position:0% +we can plot that tree so that's the + + + align:start position:0% +we can plot that tree so that's the +model that corresponds to 0.01 0.001 + + align:start position:0% + + + + align:start position:0% + +Wow okay it's best a very detailed tree + + align:start position:0% +Wow okay it's best a very detailed tree + + + align:start position:0% +Wow okay it's best a very detailed tree +you can see that looks pretty much like + + align:start position:0% +you can see that looks pretty much like + + + align:start position:0% +you can see that looks pretty much like +the same tree we had before initially + + align:start position:0% +the same tree we had before initially + + + align:start position:0% +the same tree we had before initially +the dense us or get much more detail at + + align:start position:0% +the dense us or get much more detail at + + + align:start position:0% +the dense us or get much more detail at +the bottom and in fact if you can see + + align:start position:0% +the bottom and in fact if you can see + + + align:start position:0% +the bottom and in fact if you can see +close enough there's actually latitude + + align:start position:0% +close enough there's actually latitude + + + align:start position:0% +close enough there's actually latitude +and longitude in there right down the + + align:start position:0% +and longitude in there right down the + + + align:start position:0% +and longitude in there right down the +bottom as well so maybe you know maybe + + align:start position:0% +bottom as well so maybe you know maybe + + + align:start position:0% +bottom as well so maybe you know maybe +the tree is finally gonna be blooming a + + align:start position:0% +the tree is finally gonna be blooming a + + + align:start position:0% +the tree is finally gonna be blooming a +regression model well we can test it out + + align:start position:0% +regression model well we can test it out + + + align:start position:0% +regression model well we can test it out +same we did it before + + align:start position:0% +same we did it before + + + align:start position:0% +same we did it before +this tree predictions is a predictions + + align:start position:0% +this tree predictions is a predictions + + + align:start position:0% +this tree predictions is a predictions +or a best tree on the new data the test + + align:start position:0% +or a best tree on the new data the test + + + align:start position:0% +or a best tree on the new data the test +set the best tree SSE sum of squared + + align:start position:0% +set the best tree SSE sum of squared + + + align:start position:0% +set the best tree SSE sum of squared +errors this is some the best trees + + align:start position:0% +errors this is some the best trees + + + align:start position:0% +errors this is some the best trees +predictions less the truth values that's + + align:start position:0% +predictions less the truth values that's + + + align:start position:0% +predictions less the truth values that's +when that number is 3675 + + align:start position:0% +when that number is 3675 + + + align:start position:0% +when that number is 3675 +so if you can remember from the last + + align:start position:0% +so if you can remember from the last + + + align:start position:0% +so if you can remember from the last +video the street from the previous video + + align:start position:0% +video the street from the previous video + + + align:start position:0% +video the street from the previous video +actually or need got something in the + + align:start position:0% +actually or need got something in the + + + align:start position:0% +actually or need got something in the +for thousands so not very good so we + + align:start position:0% +for thousands so not very good so we + + + align:start position:0% +for thousands so not very good so we +have actually improved this treat is + + align:start position:0% +have actually improved this treat is + + + align:start position:0% +have actually improved this treat is +better + + align:start position:0% +better + + + align:start position:0% +better +Alma testing set then the original tree + + align:start position:0% +Alma testing set then the original tree + + + align:start position:0% +Alma testing set then the original tree +we created but you may also remember + + align:start position:0% +we created but you may also remember + + + align:start position:0% +we created but you may also remember +that the linear regression model did + + align:start position:0% +that the linear regression model did + + + align:start position:0% +that the linear regression model did +actually better than that still the + + align:start position:0% +actually better than that still the + + + align:start position:0% +actually better than that still the +linear regression SSE was more around + + align:start position:0% +linear regression SSE was more around + + + align:start position:0% +linear regression SSE was more around +three thousands of 30 so the mystery is + + align:start position:0% +three thousands of 30 so the mystery is + + + align:start position:0% +three thousands of 30 so the mystery is +not as good as a linear regression model + + align:start position:0% +not as good as a linear regression model + + + align:start position:0% +not as good as a linear regression model +but cross-validation did improve + + align:start position:0% +but cross-validation did improve + + + align:start position:0% +but cross-validation did improve +performance so the takeaway is I guess + + align:start position:0% +performance so the takeaway is I guess + + + align:start position:0% +performance so the takeaway is I guess +that Teresa always I know is the best + + align:start position:0% +that Teresa always I know is the best + + + align:start position:0% +that Teresa always I know is the best +you get to be available to you but + + align:start position:0% +you get to be available to you but + + + align:start position:0% +you get to be available to you but +should always try cross validated + + align:start position:0% +should always try cross validated + + + align:start position:0% +should always try cross validated +possibility cost validating them feed as + + align:start position:0% +possibility cost validating them feed as + + + align:start position:0% +possibility cost validating them feed as +much performance out of + + align:start position:0% +much performance out of + + + align:start position:0% +much performance out of +as you can and as in the first station + + align:start position:0% +as you can and as in the first station + + + align:start position:0% +as you can and as in the first station +thank you \ No newline at end of file diff --git a/Ih01TfuEfqU.txt b/Ih01TfuEfqU.txt new file mode 100644 index 0000000000000000000000000000000000000000..a721aea1360e123b60df84d07dabf59fa9aa1cd9 --- /dev/null +++ b/Ih01TfuEfqU.txt @@ -0,0 +1,4415 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK, good afternoon. + +So this week we talk +about quantum gases, + +ultra-cold atomic gases. + +And sure, they're ideal Bose +gases, ideal Fermi gases, + +but I will spend one +or two minutes on each, + +because that's exactly solvable. + +It's in all the textbooks. + +That's simple. + +Quantum gases become interesting +because of interactions. + +And in my lecture today +and my last lecture + +I want to introduce you +to Bose gases and Fermi + +gases with inter actions. + +And they both turn superfluid, +and the superfluid properties + +are determined by the +interactions between the atoms. + +So the purpose of those +lectures is number one, + +to acquaint to you with +important phenomena + +in cold gases-- superfluidity, +superfluidity in lattices, + +superfluidity just in +free gas, in a normal gas + +without lattice, and +superfluidity of fermions. + +But at the same +time, I also want + +to have sort of a theme for you +how we deal with interactions. + +And that kind of theme +is how theoretically we + +reduce unsolvable +Hamiltonians to Hamiltonians + +which can be solved. + +And you will see that +actually appearing + +in different situations +with similarities, + +but important differences. + +So just to remind +you, we started out + +with the interacting Bose +gas in a homogeneous system. + +We have a very general +way to describe + +scattering two particles with +initial momentum disappear + +and two particles +with momenta appear. + +This is a scattering event. + +Now this means we have products +of four operators, which + +is very difficult to solve. + +And the Bogoliubov approximation +which we discussed on Monday + +replaces the operator for +the condensate for the zero + +momentum state with a Z number, +saying that N 0, N 0 plus 1 + +is the same-- a little +bit waving your hands. + +But it's also you can say +the macroscopic limit when + +we have a photon field +with many, many photons, + +we can use a Z number +in our Hamiltonian + +to describe the electric field. + +So that's the same spirit. + +So maybe I should emphasize it. + +This is for atoms. + +What you're used to do with +photons for your whole life. + +OK. + +With that we have +transformed the Hamiltonian + +into a bilinear expression. + +And so at the moment your +bilinear expression-- + +you do a Bogoliubov +transformation. + +You simply diagonalize it by +finding a new set operators + +where the cross term +between a and b or between a + +of k and a of minus k disappear. + +And then you've solved it. + +And this is what we arrived at +at the end of the last lecture. + +With those +approximations, we have + +diagonalized the Hamiltonian. + +Our Hamiltonian is now, you +can say harmonic oscillator + +Hamiltonian, or +you can see it has + +become a gas of non-interacting +quasi particles. + +Each of those operators +creates a quasi particle, + +and the quasi particle +energy is U of k. + +And I explained to +you that as expected, + +the quasi particle +energy is simply + +particles with momentum +h-bar k for high momenta, + +because in high excitation +of Bose quantums + +it is a free particle. + +But a low-lying excitation +is affected in a major way + +by all of these +interactions with + +the Bose-Einstein condensate. + +And that turns the quadratic +dispersion relation + +into a linear one, +or you can say + +that turns the free particle +into a photon or something. + +So that's my review +of the last class. + +Are there any questions +before we go further? + +Colin. + +AUDIENCE: Does this require +low density and [INAUDIBLE], + +or one or the other? + +PROFESSOR: We come a little bit +later to that, but in the end, + +there is a small parameter. + +The small parameter will be N +a cubed-- the gas parameter-- + +N, the density, a cubed, +the scattering length. + +It's usually the dimensionless +combination of the two + +which decides whether we are +in the weakly or strongly + +interacting limit. + +There is another assumption +which we have made here, + +but it's related to that-- as +you will see a few moments-- + +that most of the are +in the condensate. + +We assumed N0 is peak. + +The condensate depletion-- the +number of atoms which are not + +in the condensate, +t equals 0 is small. + +But let me just +first show you-- I + +want to mix in +theory and experiment + +how sound can be observed. + +I should actually say this +experiment is sort of dear + +to my heart, because +at some point + +it clicked to me how the +new world of atomic physics + +connects with condensed +matter physics. + +Soon after we had realized +Bose-Einstein condensates, + +a famous condensed matter +theorist said hey, Wolfgang, + +you should now observe sound. + +Sound is important. + +Yeah, OK, but how do +you observe sound? + +You know, use a piezo +and just kick the system + +and create a sound wave. + +And I said, oh, gosh, this +guy doesn't know with that + +if you put anything in contact +with the quantum gases-- + +a piezo-- the gases +will just stick to it. + +He has no idea +what our system is. + +But then I said wait a +moment-- we have to translate. + +He says use a piezo. + +Well, I have to translate. + +In atomic physics +how do we kick atoms? + +With a laser beam. + +And in that moment, +I had the idea + +that we can take a +Bose-Einstein condensate, + +suddenly switch on a blue +de-tuned repulsive laser beam. + +This will do exactly as a +piezo-- create a density + +perturbation, and then +the density perturbation + +will propagate with +the speed of sound. + +And that worked. + +That was just when Bose-Einstein +condensations were very fresh. + +One of the first +scientific experiments + +done-- we switch on +the laser and you + +see color-coded in red the +density perturbation which + +propagates out of it. + +And the slope of this line +is the speed of sound. + +And here we determined +the speed of sound + +as a function of density. + +So that's how phonons-- +or at least how + +the speed of sound +and wave packets which + +propagate with the speed +of sound can be prepared. + +I come back to phonons +and collective excitations + +in a few moments. + +But let me first say +when we have diagonalized + +the Hamiltonian we know +everything we want to know. + +I just focused on the +quasi particle energies, + +but you also know the +ground-state energy. + +And actually here Colin, +you see that the corrections + +to the ground-state +energy scale with N + +a cubed, so this is really the +small parameter in this system. + +But we can also find out what is +the ground state wave function. + +And let me use it to introduce +an important concept to you + +called the quantum depletion. + +When you have two atoms in the +condensator at zero momentum + +and you switch on +the interactions, + +the delta function interaction +couples zero momentum state + +to higher momentum states. + +So therefore, the +effect of interactions + +is that the condensate is +not just at zero momentum. + +It has some probability, +or some admixture, + +of finite momentum states. + +This is the ground state. + +This is how the Hamiltonian +is diagonalized. + +So from the Bogoliubov +approximation, + +where we introduced +this V and U parameter + +to transfer from one +set of Bose operators + +to another set of +Bose operators, + +those coefficients +give us the population + +of those momentum states in the +[INAUDIBLE] of the condensate. + +So if I now ask, what is +the condensate fraction? + +What is the number of atoms +in the zero momentum states? + +It's all atoms, but those +who have finite momentum. + +And we find again the +small parameter N a cubed. + +Now this quantum +depletion allows me now + +to make a distinction +between the cold atomic gas + +condensates and +superfluid helium form. + +In cold atomic gas condensates, +this correction is about 1%. + +So therefore, I can say +with 99% probability, + +or with 99% weight, +the condensate, + +the many-body wave +function of the condensate + +is just the zero momentum +state to the power N. + +And this very complicated +admixture of correlation + +into the ideal gas wave function +is only 1% for alkali gases. + +But for liquid helium, +the condensate fraction-- + +even at zero +temperature-- is only 10%. + +So when people use +neutron scattering-- + +it would be a long story in +itself how this is done-- + +but when they use neutron +scattering to analyze + +the liquid helium +at low temperature, + +and figure out what is the +fraction of atoms which + +have zero momentum, +they found 10%. + +The quantum depletion is 90%. + +But that's just the +difference between a quantum + +gas and a quantum liquid. + +And in the quantum liquid-- +in liquid helium-- N + +a cubed is on the +order of unity. + +OK, I mentioned this +dispersion relation. + +These are sort of +quasi particles. + +And I at least +showed you how you + +can measure the slope of the +quasi particle dispersion + +relation by propagating +sound waves. + +But let me now tell you how we +can observe quasi particles' + +elementary excitations directly. + +And this is actually simply +done by light scattering. + +If you scatter a photon, +and the scattered photon + +loses energy h-bar U. And +it is scattered at an angle. + +Therefore, it +transfers momentum q. + +These forces can +only happen if there + +is an elementary excitation +with momentum q and energy h U. + +So in other words, +on a photon basis, + +you can see photon +by photon, if you + +scatter a photon, the photon +transfers momentum and energy. + +The process can only happen if +you can form a quasiparticle + +with this momentum and energy. + +So since this is sort of the +direct way of mapping out + +whether the system +has the possibility + +to absorb momentum q and energy +h nu, this has sort of a name. + +The scattering probability is +called the dynamic structure + +factor. + +And the dynamic structure +factor is just an integral + +over all the possibilities +that a many-body system can + +absorb momentum and energy. + +Now there is one +nice feature which + +was introduced by +us at MIT, and that + +is if you're going to measure +the dynamic structure factor, + +often you do it with +neutron scattering. + +You scatter neutrons or x-rays +and they scatter spontaneously + +at an angle, and +you need a detector + +to detect the +scattered particles. + +But in our case, because +the gas is so dilute, + +the distance between +atoms is on the order + +of the optical wavelengths. + +We don't want neutrons. + +We don't want x-rays. + +We want photons, because +the wavelengths of photons + +is perfectly matched +to the properties, + +to momentum transfer and +such we need for our system. + +But photons-- we +have photon lasers. + +So instead of in a painstakingly +way analyzing the frequency + +and the momentum of +scattered photons, + +we don't do the spontaneous +scattering process. + +We do a stimulated process. + +We use two laser beams, +and we stimulate a photon + +to be scattered into +the other laser beam. + +And by having the two laser +beams at frequency difference + +delta omega, we're +really asking the system, + +are you ready to absorb +delta omega energy? + +If yes, then you +have a quasiparticle. + +So this is how we do +quasiparticle spectroscopy. + +And a few years +later, this method + +was defined by the +[INAUDIBLE] Institute. + +And what you see +here is they varied + +the angles between the +two laser beams, realized + +different momentum +transfer, and what + +you see is the low dispersion, +the linear dispersion + +relation for low +momenta, and then + +the quadratic part +at high momentum. + +So this is called +BEC spectroscopy. + +It's a variant, you can see, +of Raman spectroscopy where + +you go from a zero quasiparticle +state to a one quasiparticle + +state through a +simulated Raman process, + +and this is how the dispersion +relation is determined. + +OK so I've so far +dealt with aspects + +of a homogeneous Bose-Einstein +condensate where, + +of course, if you're +a homogeneous system, + +you formulate everything +in momentum space. + +But now we want to +deal with the situation + +that our condensates +are finite in size. + +And in addition, they're +usually in a harmonic oscillator + +potential, and therefore their +density is inhomogeneous. + +Let me start the discussion with +the inhomogeneous Bose-Einstein + +condensate by showing +again a picture which + +brings in some +memories of '90, '96. + +It was the first +time that we could + +see the Bose-Einstein +condensate in the trap. + +Before people have just +seen it by time of flight + +when it was pretty +much already destroyed + +or it was just flying out. + +But here we see the trapped +Bose-Einstein condensate + +and we could even +take multiple pictures + +of the same condensate. + +So you can see that +this was the first time + +that a condensate +was seen alive. + +What you see here is actually +the bimodal distribution. + +You see the condensate and +then due to speckled pattern, + +the Fermi cloud +looks fragmented, + +but this is just a +speckled pattern due + +to the signal to noise. + +But here you really see now-- +not in ballistic expansion + +as I showed you on Monday-- +but really insight to the size + +and shape of the condensate. + +OK, how do we describe it? + +Well, the message is pretty +much exactly the same way + +as we did with the Bogoliubov +approximation and such, + +but instead of in +momentum space, + +we do it now in position space. + +Actually, I have +to say this week, + +I go through a lot of material. + +But what I'm trying +is to give you + +sort of a spirited +and animated overview + +that you really know +what is important. + +Where is the same +concept appearing again + +in a different way. + +The details-- I've +posted, actually, + +the original +articles, references. + +Some of are school +notes, some of them + +written by myself +on the backside. + +So yes, it's a little +bit different character + +than other lectures. + +I want to show you +a lot of things, + +and put a special +emphasis on the ideas. + +OK, so in second +quantization, we + +are now using field operators +which create and annihilate + +particles at position R. +This is the single particle + +Hamiltonian-- kinetic +energy and potential energy. + +And our interaction term has +now, again, four operators-- + +two interrelation operators, +two creation operators, + +but they're now formulated +in position space. + +We do exactly the same as we +did in the homogeneous gas. + +We assume the potential +is short range. + +That means delta function. + +And that means we +can get rid of one + +of the integrations +in r and r prime. + +But we still have product +of four operators. + +We can formally solve the +equation by writing down + +Heisenberg's situation for the +equation of motion for those + +field operators, but of +course this cannot be solved. + +Remember products are +four operators are hard. + +We have to reduce +it to two operators. + +And this is actually done by the +Bogoliubov approximation again. + +But it's done here +in the following way. + +Remember, in the momentum space +we replaced a0 and a0 dagger + +by the square root of a0. + +What we do here is we say this +is sort of a quantum field. + +And when we have a superfluid, +this field operator + +has an average value. + +It's actually the macroscopic +superfluid order parameter. + +So we replace the operator +by an average value + +which we assume is large, +because many, many particles + +are in the superfluid state. + +And then we have +fluctuations which are small. + +And what we will do is-- it's +pretty clear-- when it comes + +to the fluctuations, we will +neglect higher products-- + +products of four +fluctuation operators. + +And we are down to C +numbers and, as you + +will see, two operators. + +We can-- and this is +even more dramatic-- + +it wouldn't make sense +in momentum space, + +but it does make sense +in position space-- + +we can even do a +first approximation + +where we completely +neglect those fluctuations. + +And then what we have +is when we simply + +insert a [? Z ?] number +into this Hamiltonian. + +We have then an equation +for this number, + +for this function psi. + +And this is the nonlinear +Schrodinger equation, + +or it's also called +Gross-Pitaevskii equation, + +which is now the analogy +to Schrodinger's equation, + +but now for the macroscopic +wave function which + +is occupied by many, +many particles. + +And in addition to +the kinetic energy + +and the trapping potential +in the external potential, + +it has a term which is +proportional to the density. + +And this is just +mean field repulsion + +which one atom feels +exerted by the other atoms. + +I should say-- +just to connect it + +to what I've said earlier +about the quantum depletion-- + +that you can regard the +function psi as the best + +approximation to an ideal +Bose-Einstein condensate. + +So if you want to write +your many-body wave + +function as a function +psi to the power N, + +all particles are in +the same quantum state, + +then a variational +calculation would + +say that this function psi +should obey this equation. + +If you want to read +up what I've said, + +I've posted a recent paper, +which I found very pedagogical, + +where they derive the +Gross-Pitaevskii equation + +without even using an +operator psi dagger, + +without using any +second quantization. + +They just say we have an +Hamiltonian for an interaction + +system, and we try to write +the complicated, many-body wave + +function as a wave +function to the power N. + +And then you put this +ansatz into your Hamiltonian + +and do a variation optimization +which single-particle wave + +function psi, if +taken to the power N, + +minimizes the total +energy of N particles, + +including interactions. + +And the answer is this equation. + +So there are many +ways this equation + +is sort of very natural. + +Now you all know about +single-particle physics-- + +kinetic energy in an +external potential. + +Let's now learn what this +density-dependent term does. + +Well, it's pretty clear. + +There is a price to +be paid for density. + +And while the total +integrated density, of course, + +is given by the total +number of particles. + +That means if you lower +the density somewhere, + +you have to increase +the density. + +But because this is +a non-linear term, + +if you have an average +density and you lower it + +here and increase it here, you +have actually more repulsive + +energy than if the +density is flat. + +So this term has only one goal. + +It wants to flatten +out densities. + +So therefore if we +have a box potential + +and you know the +ground state in a box + +is just half a period +of a sine function. + +This is a non-interacting +condensate. + +This would be the +macroscopic wave + +function in a box potential. + +But if you now put in +strong interactions, + +the strong interaction's going +to flatten out the potential. + +They flatten out the +potential, and only at the very + +last moment-- all +right, now it's + +time to go down because we have +to meet our boundary condition. + +And the length scale where +you eventually go down-- it + +has a famous name, +the healing length-- + +is the length scale +where the kinetic energy + +due to the curvature +of the wave function + +is now comparable to +the interaction energy. + +If the system would +curve down earlier, + +it would cause too +much repulsive energy, + +because the density +is not kept flat. + +If it would curve down too +late, the enormous curvature + +would mean a lot +of kinetic energy. + +And this is just +the best compromise + +between those two criteria. + +So that's how you derive +the healing length. + +The healing length is +now the length scale + +over which the system is willing +to meet boundary conditions, + +and not stay flat, +as flat as possible. + +Yes. + +AUDIENCE: Just curious-- +in that equation, + +the atom has the mass +of each individual-- + +PROFESSOR: The mass is +the mass of a single atom. + +AUDIENCE: Single atom, +it's not-- sorry, + +I wasn't here last time. + +But the quasiparticles are +the same mass [INAUDIBLE]. + +PROFESSOR: In a Bose-Einstein +condensate they are. + +We haven't changed the mass. + +But we're not talking +actually about quasiparticle. + +We're actually really talking +about here qualitative features + +of the solution of the +Gross-Pitaevskii equation. + +And the Gross-Pitaevskii +equation + +is sort of a single particle +equation for particles of mass, + +of the original bare mass +M. It's a macroscopic wave + +function, but I sometimes say +it describes the wave function + +of a single particle where +all the other particles are + +included at the +mean field level. + +So therefore, it is really +this, the atomic mass, + +and not any form of +collective mass here. + +Well, if you would now +ask how do interactions + +transform the first excited +state in the box potential? + +Well, then it's again flat +this as much as possible. + +But then if you want to +maintain the parity of the wave + +function, then it's +only close to the zero + +crossing within a healing length +that the system says OK, now I + +change sign. + +So that's sort of what is inside +the Gross-Pitaevskii equation. + +Now once we realize that, we +can take it to the next level + +and say, well, if you +neglect-- let's say + +we're interested +in the ground state + +and we neglect this +boundary region where + +the kinetic energy +becomes important-- maybe + +we can simplify the +Gross-Pitaevskii equation + +by neglecting the +kinetic energy. + +If potential energy dominates +by far, we can neglect that. + +And then we should +get a good description + +which will not be valid in +the wings of the wave function + +but in most of space. + +But now if you look +at this equation, + +it's no longer a +differential equation. + +It has no derivatives. + +It's just something +which applies + +to the wave function psi itself. + +And we can simply solve that. + +The solution of that +is that psi squared-- + +the density-- is +nothing else than there + +is a constant minus the +inverted trapping potential. + +So therefore in this +Thomas-Fermi approximation + +where we neglect the +kinetic energy completely, + +you just take your trapping +potential, turn it upside down, + +and then you fill +it up with density + +until you have accommodated +the number of atoms + +you want to accommodate. + +And this is, of +course-- the constraint + +in the number of atoms is +determined by the chemical + +potential. + +Or if you have a more +complicated W-shaped potential, + +the same construction. + +Flip it over, fill it up, +gives you the condensate wave + +function, the +density distribution + +of the condensate +in this potential. + +I don't want to belabor +it, but coming back + +to the question of +the small parameter, + +if you look at +those equations, you + +can identify a parameter-- this +is now the small parameter, + +or the parameter +in the system which + +is the important +dimensionless parameter. + +It depends on the +number of atoms, + +and it depends now on the ratio +of the scattering length-- + +which characterizes +the interaction-- + +and the harmonic +oscillator length. + +You can say the +harmonic oscillator + +length is the ideal wave +function harmonic oscillator. + +So this parametrizes the +importance of kinetic energy, + +whereas the scattering +length parametrizes + +the importance of interactions. + +And all those solutions +can be nicely written + +as what you would +have in an ideal gas, + +and then this parameter X. So +in typical experiments, N a, + +N is a million. + +The scattering length is smaller +than the oscillator length, + +but N is a million, and this +parameter X is usually large. + +So therefore-- and I'm +simply just talking + +about this solution-- we have +the situation that the chemical + +potential is larger +by a power of X + +than the ideal gas solution, +which would just be the ground + +state with its zero point energy +in the harmonic oscillator + +potential, or the width-- the +size-- of the wave function + +is larger than the ground state +of the harmonic oscillator, + +but only with an exponent, +which is one-fifth. + +Well, we can see that. + +These are now, again, +somewhat improved pictures + +of condensates inside the trap. + +For the expert, the +previous picture + +was dark-ground imaging. + +This is now +phase-contrast imaging. + +And if you take a +profile, we clearly + +see the condensate wave function +and we see the thermal wings. + +When we look at the size of +the condensate wave function, + +you realize what I just meant-- +that the ground-state wave + +function, the harmonic +oscillator length + +is 7 micron in the +axial direction, + +but here you have 300 micron. + +So this condensate is completely +dominated by interactions. + +And it fulfils very nice, and +pretty much the whole shape, + +except maybe some +details in the wings, + +are quantitatively described +by the simple approximation + +I have explained to you. + +So just a little +bit show and tell. + +We have this +Gross-Pitaevskii equation. + +The Gross-Pitaevskii equation +has, as Schrodinger's equation, + +a time independent form +to get the ground state. + +It has also a time +dependent form. + +You simply replace the +energy by the derivative + +of the wave function. + +This is the time-dependent form. + +Everything is very simple, and +you can do many-body physics, + +but on your computer, +you pretty much look + +for single-particle +wave function + +and take them to the power N. + +So some areas where the +Gross-Pitaevskii equation + +has quantitatively +explained experiments-- one + +is the expansion of a +Bose-Einstein condensate. + +It's this famous +situation when you + +have an elongated condensate +and let it expand. + +It expands faster in +the radial direction. + +One simple argument +is the pressure + +of the mean field is larger and +leads to faster acceleration. + +So therefore, if you have +a cigar-shaped condensate + +and release it, it +turns into a disk. + +It inverts the aspect ratio, +going from a cigar shape + +to a disk shape. + +And that has been beautifully +and quantitatively described + +by the Gross-Pitaevskii +equation. + +Here we have measured +the interaction energy + +as a number of condensed atoms. + +And I mentioned to you that +this X parameter comes often + +with power 1/5 and 2/5. + +And this here is a +fit to the power 2/5, + +beautifully +confirming the theory. + +So the Gross-Pitaevskii +equation was + +invented in 1962, about 50 years +ago by Gross and Pitaevskii + +to describe vortices. + +Actually, Lev Pitaevskii +is still alive, + +going strong, and +publishing papers. + +One of his latest predictions +was solitons in Fermi gases, + +and I know in Professor +Zwierlein's group, + +one of his lab just looked +at the same physics, + +and compared to the +theory of Lev Pitaevskii. + +And this year we +are celebrating-- + +I forgot, the 85th or +90th birthday of him. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: 90? + +AUDIENCE: There's a poster. + +PROFESSOR: I know there's +a poster next to my door, + +but I forgot which anniversary. + +So I mean, he's an legend. + +But he's still walking. + +He's still doing science. + +So if you meet him, you go +back to 50 years in history. + +Anyway, it is this +Lev Pitaevskii, + +and he invented his equations +to describe vortices. + +So anyway so we have this +nonlinear Schrodinger equation. + +Let me just show you +what vortices are + +and how they are formed. + +Vortices come-- if you solve +the Gross-Pitaevskii equation-- + +if you ever any quantum +fluid or quantum gas, + +and you add angular momentum, +the angular momentum cannot + +lead to rigid body rotation. + +This would violate the fact +that the velocity field has + +to be irrotational to make +sure that the phase of the wave + +function is well defined. + +So if you rotate the system, +it can absorb angular momentum + +only by forming vortices. + +And vortices are singular points +of the wave function-- singular + +points where the density is 0. + +In other words-- I don't have +time to be exhaustive here-- + +but when something +rotates, there + +is a dynamic phase you +can say, because there + +are matter waves +going in circles. + +And the integral +of the phase has + +to be an integer number +of 2 pi, otherwise + +you would not have a +well-defined phase of the wave + +function. + +And if you now say you make +a circle, which is 2 pi. + +You make the circle +smaller, smaller, smaller. + +In the middle of the +circle, you go around. + +The wave function +changes by 2 pi, + +but what should the wave +function do on one point? + +Which number between 0 and 2 pi +should the wave function peak? + +Well, the wave function +says I can't peak. + +I just go to 0. + +And a 0 value has no +phase and I'm fine. + +That's exactly what the +wave function tells you. + +So therefore if you want +to describe vortices, + +you want to now describe the +Gross-Pitaevskii equation, + +but with the boundary condition +that the wave function + +goes to 0. + +And if you want to +describe one vortex, + +you want the wave function to +go 0 in the center of the cloud. + +And so you make a +corresponding Ansatz. + +You allow the phase to +wrap around by 2 pi, + +when the angle phi is varied. + +And then when you solve +it, you have, of course, + +put in that there should be a +0 of the density at the center. + +And it's now nice for me to-- +there's an important review + +paper which describes +all that and more-- + +but it's nice to +show you now the two + +extreme cases of the ideal +condensate without interaction, + +and the strong +interacting condensate. + +The ideal condensate-- well, we +are in the first excited state + +of the harmonic +oscillator potential. + +And this is the dashed line. + +And of course, the size +of the whole, the 0, + +is pretty much on the order +of the oscillator length, + +because there is no +other length scale + +in the ideal +harmonic oscillator. + +But if you have the +interacting system, + +remember what +interactions are doing. + +They want to keep the density +as constant as possible. + +Well, we are not +in a box potential. + +We're in an inverted +parabola potential. + +And remember, our +Thomas-Fermi solution, + +which neglects kinetic energy, +is the inverted parabola + +up to here. + +And then the tail is +when we can no longer + +neglect the kinetic energy. + +But if we now say, OK, fine, +but now in addition, we + +want a vortex in +the center, the wave + +function out there says no. + +We do what minimizes +kinetic energy, + +and what minimizes +repulsive energy. + +We follow the inverted +parabola, and only + +at the very last moment-- on +the scale of the healing length, + +the system meets the +required boundary condition + +that the density goes to 0. + +Anyway, with this +qualitative understanding, + +you can get a lot out of those. + +You can immediately +understand the salient feature + +of the solution. + +Question? + +AUDIENCE: I know we're +not talking details, + +but is there a simple, +maybe clear reason why + +when you spin a +Bose-Einstein condensate + +you get many vortices, but +when you spin your coffee + +in your cup, you +just get one big one? + +PROFESSOR: Yes. + +So the question is, if I have +a wrap-around of 4 pi in phase, + +whether the system should have +a doubly charged vortex, or two + +singly charged vortices? + +What is the +difference in energy? + +Well, what happens is doubly +charged vortices are unstable. + +My group, at some point, +were the first to create + +doubly charged +vortices, but we saw + +that they immediately decayed. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Pardon? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: Initially, +we couldn't observe. + +We just saw that +it was unstable. + +But it's a decay +into two vortices. + +But it's easy to understand. + +If you put two vortices +on top of each other, + +what is the energy of the +system compared to one vortex? + +Well, the energy of a vortex is +the rotational field around it, + +and if you superimpose +two vortices, + +the velocity around the +doubly charged vortices + +is twice the velocity +of one vortex. + +And therefore, the kinetic +energy is four times. + +If you have two +vortices which are + +far separated that it has +its own velocity field. + +It has its own +velocity field here. + +And when the two velocity +fields come together, + +the velocity is +already so low that you + +don't have to consider that, +then those two vortices have + +an energy which is two times +the energy of a single vortex. + +So therefore, when +the two vortices, + +they start out with four times +the energy of a single vortex, + +and when they dissociate +and repel each other, + +they have shed half +of their energy. + +So this argument +tells you immediately + +that vortices are +in effect repulsive. + +And therefore, any +multiple-charged vortex + +will spontaneously decay. + +It's also this net +repulsion between vortices + +which makes the vortices +arrange in a regular lattice. + +The regular lattice +which you saw before + +is Nature's answer to +how can we minimize + +the energy of all +those vortices? + +And the idea is let's keep the +average distance between them + +as large as possible, and the +answer is a hexagonal lattice. + +Yeah. + +AUDIENCE: So a few +slides back, when + +you write the G-P equation, when +you plotted sort of for the box + +potential, the ground state +and the excited state comparing + +the G-P equation to the typical +single-particle [INAUDIBLE]. + +And so I guess I'm a +little bit confused + +about how excitations manifest +themselves in the system. + +Because in some sense, if you +were to solve the G-P equation, + +would you arrive at a +spectrum of solutions? + +Then I guess I'd be confused +at whether excitations manifest + +themselves into that +spectrum of solutions, + +or rather than they become +excitations, sort of deviations + +from the mean field as +including the [INAUDIBLE]. + +PROFESSOR: You are now +asking about something + +more complicated. + +You're asking what +are the excited + +states of the many-body system? + +And actually, we have +already found one answer. + +And this is if you want +these small excitations, + +it's one particle +becomes a phonon, + +or one particle becomes +a quasiparticle. + +What we are talking +about here is + +what happens if the +whole macroscopic wave + +function is in an excited state. + +So we are asking here in +the box potential what + +happens if you force all N atoms +to have one node in the wave + +function. + +And this is what I'm +talking about here. + +So the excitation +energy of this state + +here is much, much higher +than of single quasiparticle + +excitations. + +I'm not sure if I'm addressing +your question here, but-- + +AUDIENCE: So with +single quasiparticle + +excitations, are +those essentially sort + +of deviations from +the mean field? + +PROFESSOR: No, they +are-- you really + +look for many-body physics-- +main field deviations-- + +probably. + +I mean, what you do +is in that sense, yes. + +You're allowing in this +Ansatz that psi operator + +is psi average +plus fluctuations. + +You now look for +fluctuations, and you're + +looking for the +energy eigenspectrum + +of those fluctuations. + +And the answer are +quasiparticles. + +So it is, actually, +the Bogoliubov solution + +for the spectrum of +the fluctuations. + +And the answer is the dispersion +relation I presented to you. + +Whereas here we +are asking what are + +excited states of the +macroscopic wave function? + +It's a very, very +different question + +which we've addressed here. + +Yes. + +AUDIENCE: So when you +stir the condensate, + +do you view it as-- do you +stir, sort of, at the trap + +frequency, so I do sort +of N single excitations? + +Or do you stir at N +times the trap frequency, + +so you get one sort of +N particle excitation? + +PROFESSOR: Well, the +experimental answer + +is you want to stir at the +quadrupole frequency, which + +is square root 2 times +the trap frequency. + +Then you create +quadrupolar excitations. + +The quadrupolar excitation can +be regarded as a standing sound + +wave, but you create +a macroscopic number + +of those excitations. + +So you make, actually, the +whole condensate wave function + +oscillate in a +quadrupolar pattern, + +but it's a rotating +quadrupole, and that + +eventually then rearranges +itself and leads to vortices. + +So I think the correct answer +is the most efficient way + +to create vortices would be to +excite quasiparticles, but then + +create so many-- and this may +relate to Matt's question-- + +create so many quasiparticles +that you have really + +a time-dependent and oscillating +macroscopic wave function. + +So eventually, you have +a coherent excitation + +of quasiparticles. + +And that eventually means +the condensate moves + +in a quadrupolar pattern, but +it's a quadrupolar pattern + +with rotation, and +that eventually + +turns into many vortices. + +But that's really a very rich +question which you're asking, + +which has been studied-- a lot +of different aspects of that + +have been studied. + +OK, so we've talked about +Bose-Einstein condensates + +in a homogeneous system, just +sort of to lay the groundwork. + +We've talked about +Bose-Einstein condensates + +in traps in +inhomogeneous system. + +Now we want to talk about +Bose-Einstein condensates + +in optical lattices. + +Well, there are two reasons +why we want to do that. + +One is we want to use the +Bose-Einstein condensate + +to obtain deeper insight into +the properties of matter. + +And a lot of forms of matter +appear in periodic lattices. + +So if you put a +Bose-Einstein condensate + +into a periodic +potential, we can at least + +understand some +of the properties + +of crystalline +matter, or electrons + +which are block waves +in a periodic potential. + +So this is one reason why. + +The other reason why we want +to go to optical lattices + +is the following-- ideal +Bose-Einstein condensates + +are trivial. + +Weakly interacting Bose-Einstein +condensates are entertaining, + +and you can write a lot of +papers, have a lot of fun + +with it, develop your methods-- +also mildly intellectually + +interesting because how those +weak interactions manifest + +itself in vortices and all. + +It's really rich +and interesting. + +But the conceptional +problems appear + +when you go to +strong interactions. + +Strongly correlated matter is +where mean field descriptions + +no longer work. + +This is really the frontier +of our understanding + +of many-body systems. + +And when you want +to be there, you + +want to create a strongly +correlated system. + +And strongly correlated systems +means that the interaction + +energy dominates +over kinetic energy. + +In Bose-Einstein +condensates you can only + +go so far with +increasing interactions-- + +why are Feshbach resonances? + +Because you get into some +inelastic collisions. + +So that's one knob to turn. + +You go to larger and larger +of scattering lengths, + +and crank up the interactions. + +But if atoms strongly interact, +they start to do bad chemistry. + +They start to spin flip. + +They do other things. + +And in some cases you +keep it under control. + +In others, you just can't +keep it under control. + +But another way to get +to strong interactions + +means you reduce +the kinetic energy. + +It's the ratio of the +two which matters. + +And when you put particles +in a lattice, well, + +the lattice actually +reduces the kinetic energy. + +You may know from +condensed matter physics + +that in a lattice there is +an effective mass, which + +is higher than the +[INAUDIBLE] mass. + +Therefore you've reduced +the kinetic energy. + +Or if you want another +hand-waving approximation, + +the kinetic energy is +given by the bandwidths. + +And if the tunneling +becomes slower and slower, + +the width of your +band becomes narrower, + +and your kinetic energy is less. + +So anyway, I can give you many +hand-waving approximations + +why in a lattice, +kinetic energy is reduced + +and repulsive energy +is probably enhanced, + +because instead of having +your atoms spread out, + +they're bunched up +at each lattice site + +into a higher density cloud. + +So anyway, maybe you're +interested in parity + +potentials, or you're +interested in quantum systems + +with strong correlations. + +For whatever reasons, you +want optical lattices. + +Now I have here a +few slides which + +introduce periodic +potentials, but it is really + +just the single particle +physics in a periodic potential. + +It has nothing do +with quantum gases. + +This could be the +first lecture of how + +to describe +electrons in a metal. + +So let me just quickly +go through assuming + +that almost all of +you are familiar. + +But I use those slides also just +to give you a few definitions + +and introduce a few symbols. + +So this is simple, boring, +exactly understood physics. + +We have a Hamiltonian +which has kinetic energy, + +and a periodic potential which +is our lattice potential. + +It's rather trivial to solve, +but exactly for your wave + +function, you use +Bloch's theorem + +and divide it by an exponential +factor with quasi momentum + +times a periodic function. + +And if you now solve +Schrodinger's equation, + +you want to use Fourier space. + +You Fourier analyze +the wave function. + +You Fourier analyze +the potential. + +And since the +potential is periodic, + +sine square potential has +only three Fourier components + +at 0 plus/minus 1 times the +periodicity of the lattice. + +You do a Fourier expansion for +your periodic wave function. + +And if you insert that into +Schrodinger's equation, + +well, the Fourier transform +has turned the differential + +equation into an +algebraic equation, + +because the second +derivative simply + +becomes now k +squared or q squared. + +So in other words, you have +a set of linear equations. + +There is an index +which is the band + +index-- how high +do you want to go? + +And usually you truncate it. + +But it's the same. + +It is that same +trivial story which + +is told in all textbooks of +condensed matter physics. + +If you have no band structure, +well, you have the parabola, + +but to prepare for +band structure, + +I've opened it down here in +the first Brillouin zone. + +And if you now +introduce a lattice, + +you introduce band gaps, and you +go from the left to the middle + +to the right for stronger +and stronger lattices. + +So the case which +I will focus on, + +because it is the most extreme +case away from free space, + +is this case which is called +the tight binding limit, where + +the potential energy of +the lattice is large. + +And large means compared +with the kinetic energy + +at the Brillouin +Zone, which is k + +squared-- k is the lattice +momentum-- k squared over 2 m. + +And that's the recoil energy. + +So that our dimensionless +parameter here + +is the depth of the +lattice measured + +in recoil energies +of the photon, + +because that is +the kinetic energy + +of the free gas at +the Brillouin zone. + +OK there are few things which +immediately simplify that. + +Once we're in the +tight binding limit, + +our lattice is really +deep, and each side + +forms a harmonic oscillator. + +And the harmonic +oscillator frequency + +is analytically given by +the depth of the lattice. + +And the solution here +for the lowest band + +is that the lowest +band-- the energy + +in the lowest band, the +dispersion relation is-- well, + +we have a harmonic oscillator +in each site at x y z. + +So the average energy +in the lowest band + +is the 0 point energy in x, y, +and z-- three half h-bar omega + +0. + +And then we have a +cosinusoidal band structure + +where q is the quasimomentum. + +And what appears here as the +only interesting parameter + +is j. + +And j is I think this 4 +should be 4j is the bandwidth. + +So what appears here now +for the first time is j. + +It appears here +as the bandwidth. + +But let me immediately give +it another interpretation + +as a tunneling matrix element in +the following way-- right now, + +we have formulated the physics +in Bloch wave functions + +which are infinitely extended. + +The Bloch wave functions +are for the lattice + +what plain waves +are for free space. + +But if you have +tight binding limit, + +there is another limit +which is important. + +Namely, a particle is localized +and hops around in the lattice. + +The localized particle, of +course, is in free space. + +It would be a wave packet-- a +superposition of plain waves. + +So let's do the +same in the lattice. + +Let's construct +superpositions of Bloch waves. + +And these are our wave packets. + +And the wave packet is now +called the Wannier function. + +And there is a +mathematical procedure + +how you should pick +the phases here + +to get the maximal +normalization. + +But the simple picture is +those Wannier functions are + +very, very close to the +Gaussian ground state + +solution of the harmonic +oscillator on each side. + +The wings are different, but +I don't want to go into that. + +You transform from an +orthonormal basis of Bloch wave + +function to another orthonormal +basis Wannier function. + +And the Wannier functions are +as well localized as possible. + +That's the procedure. + +And now we can simply +rewrite our total Hamiltonian + +or everything we're interested +in, not in Bloch wave functions + +but in Wannier wave functions. + +And what comes out now is, +is that the bandwidth j + +is nothing else than our +Hamiltonian with kinetic energy + +in the periodic potential. + +But j becomes now +a matrix element + +between two Wannier functions. + +But the Wannier +functions have now-- I'll + +put in some indices +in a moment-- + +connect now two different sides. + +So it is-- you have +Wannier function. + +You have the Hamiltonian +and connect it + +to another Wannier function. + +So it is the amplitude +that, with the Hamiltonian, + +the particle can hop from +one side to another side. + +So therefore j, which +was the bandwidth, + +is now the tunneling +energy divided + +by h bar-- the tunneling +rate from on one side + +to the other side. + +For very deep lattice, +everything is analytic + +and it can easily be solved. + +And I mentioned already in the +tight binding approximation, + +you should think about +your Wannier function + +as just localized +Gaussian eigensolutions + +of the harmonic oscillator. + +Yes? + +AUDIENCE: So qualitatively, this +question sounds sort of silly, + +but normally when we write +down the solution for j, + +we're only considering +nearest neighbor. + +But from the math, +I don't immediately + +see why we wouldn't +include i equal to j. + +PROFESSOR: Give +me one more slide. + +So I should've +actually-- what I should + +have done is that-- +j has an index here. + +I just didn't want to +overload you with indices. + +I mean, this is sort +of just telling you + +what j is in its simplest form. + +It is loaded with indices and +I well show you in a moment + +where those indices come in. + +So I just wanted to +give you the idea + +if we want to have +Wannier function. + +We hop from one Wannier +function to the other one, + +and the operator +is the Hamiltonian. + +And therefore, there +should be an index j and l. + +And maybe-- let me just do the +next step first and then come + +back to it, but I +wanted to tell you here + +what I'm aiming at-- +namely interpretation of j, + +of tunneling from +one side to the next. + +But right now I haven't really +told you which j I really mean. + +There should be-- based +on the right-hand side, + +there is a j which +has two indices. + +And I will make the indices +disappear in a moment. + +But before I make those +indices disappear, + +let me introduce the other +relevant parameter, which + +will also have +indices, and that is we + +have to bring in +the interactions. + +We want to describe +an interacting system. + +We describe an +interacting system + +using the short-range +approximation + +by assuming that two particles +interact with a delta function. + +And if you have two particles +on site, each of them + +has a density which is the +Wannier function squared. + +And the product of the +two densities integrated + +gives us the expectation value +for the repulsive energy. + +And this is given here. + +So the moment we +introduce interactions, + +we are now interested in +the interaction energy + +between two particles which in +this case occupy the same side. + +OK so I've tried to introduce +was what sort of j is. + +j is a matrix element +between two Wannier functions + +with a Hamiltonian in between. + +And u is the matrix element +of two Wannier functions + +with the interaction +operator in between. + +And now I want to +use that concept + +to take my full +Hamiltonian and transform + +from field operators localized +at x to Wannier functions. + +So they B operators are +now creation operators. + +They create an atom +in a Wannier function. + +In other words, B +dagger means you + +have a particle in a +Wannier function at site i. + +And I just use that as +a basis transformation + +and the exact transformation +of this Hamiltonian + +is now into this form. + +So + +What I have right now is, I have +the tunneling matrix element + +between particles +at site i and j, + +and I have to sum +over all of them. + +And in terms of interaction, +I can calculate this matrix + +element by using Wannier +function with four + +different indices +and ask what happens. + +And this is simply an +exact way of rewriting it. + +And here I've given +you the definition. + +So if you want to +forget everything + +I told you about j and u, I've +done an exact transformation + +from field operators to Wannier +function creation operators. + +And this introduces tunneling +terms like this from site i + +to site j. + +And these here includes products +of four Wannier functions + +which are responsible +for the interaction term. + +Actually, if this is +not complicated enough, + +I've suppressed +band indices here. + +I should also now sum +over all possible bands. + +But OK, I want to come now +to the leading approximation + +in a tight binding model. + +And that is where-- +I mean those Wannier + +functions are overlapped. + +Two neighboring Wannier +functions barely overlap. + +If I go further away, the +overlap becomes even smaller. + +So the most dominant terms are +nearest neighbor interactions. + +And the nearest +neighbor interaction + +is where i and j differ by 1. + +And this is what I +call j without indices. + +And similarly, when it comes +to the interaction term + +where we have products +of four Wannier functions + +and we want to get the +overlap of all four, + +and then multiply it with g, +the prefactor of our delta + +function to get an +interaction term, + +well the best overlap is if +all indices are the same. + +And this is what I call U. + +So in that limit, in +that tight binding limit, + +my Hamiltonian is +now very simple. + +It consists of a tunneling +term parametrized with j, + +and an on site interaction +term parametrized with U. Yes. + +AUDIENCE: So you're saying +i, j and k are all the same, + +so the interaction +is with itself? + +PROFESSOR: No, two +particles per site. + +When the four +particles are the same, + +it turns into-- this +Hamiltonian here has + +all indices are the same. + +And if you calculate that, it +turns into the product of 2 b. + +b dagger is the occupation +number at each site. + +But if you're careful +with commutators, + +it becomes occupation number +times occupation number + +minus 1. + +If you have only one particle +per site, this term is 0. + +So technically U is, if +you put in 2 times 1, + +if you have two +particles per site, + +U is the interaction energy +between two particles. + +Just use this +expression to figure out + +what it is for three or four. + +But for one particle, you get 0. + +The self interaction of a +particle is absolutely 0. + +One particle does not +interact with itself. + +AUDIENCE: That gets back to my +question with the [INAUDIBLE]. + +So when you have i equals j, the +[INAUDIBLE] term, do you just-- + +PROFESSOR: No, I assume, +i j is nearest neighbor. + +I assume that the index +i and j differ by 1. + +AUDIENCE: Yeah, I mean your +argument was that the best + +overlap is between +nearest neighbors. + +PROFESSOR: Yes. + +AUDIENCE: So an overlap +with the Wannier functions + +at the same site is sort +of the kinetic energy term. + +Is it approximately 0, +or you just absorb that + +into the chemical potential? + +PROFESSOR: This is a 0. + +AUDIENCE: [INAUDIBLE] +So we're only + +looking at nearest neighbor, +so are we essentially saying + +the case where i equals j is +approximately 0 [INAUDIBLE]. + +AUDIENCE 2: Because +it's the matrix element + +of a Hamiltonian. + +So p, the candidate, plus +the lattice operator. + +So if I take my +Wannier function, + +which is built out of +eigenvalues for that equation, + +[INAUDIBLE] bunch +of energy terms. + +On every site [INAUDIBLE] +they're the same. + +Because you have a common +[INAUDIBLE] energy that you can + +[INAUDIBLE]. + +AUDIENCE: Well then just +multiple it by [INAUDIBLE]. + +PROFESSOR: My gut +feeling is-- and this + +is why nobody considers +it-- it's just + +a constant energy, which is +probably something like the 0 + +point energy times the number +of particles, which is not + +affecting any dynamics. + +It's pretty much a constant +which can be simply dropped. + +Let me just go +back to that slide. + +I hope-- let me just +look up the reference. + +I haven't looked at it recently. + +When we do this +exact transformation, + +there should be a +reference whether i + +and j, what happens +when i equals j. + +I think it's just +a constant term. + +AUDIENCE: Because +if you're summing + +over every single +lattice site, so + +you get the number of +particles times 0 [INAUDIBLE]. + +PROFESSOR: Yeah, but +even mathematically + +it gives just a constant term, +here, which is [INAUDIBLE]. + +Thanks. + +It was good to clarify it. + +OK, I think within +the next 20 minutes, + +I can step you through +the superfluid to Mott + +insulator transition. + +First, references for what +I've just said are given here. + +But let me now come take +this Bose-Hubbard model + +and discuss its +two limiting cases. + +One case is where U +is much larger than j. + +The other case is where +j is much larger than U. + +These are the two +limiting cases, + +and it will turn out +that one is an insulator + +and one is a superfluid. + +And that makes perfect +sense, of course. + +If U is much larger than +j, I can set j equals to 0 + +if I can neglect it. + +No tunneling means no transport, +and that means an insulator. + +It's also clear that when +there is no tunneling, + +that the system is +really described + +by a product of so and so +many particles per site. + +So it could be one +particle per site. + +And I have a product +over all sites, + +or two particles per site. + +So this will be +the ground state. + +And it's called the ground +state of the Mott insulator. + +It's also trivial +to discuss what + +happens if j is much, +much larger than U, + +because then I simply neglect +U, and I have a free gas. + +Well, a free gas of +Bloch wave function, + +but that's the same as a free +gas of planar wave function. + +It's just that quasimomentum +replaces momentum. + +And if you have just +an ideal Bose gas + +in a periodic lattice instead +of Bose-Einstein condensation + +in the lowest +momentum state, you + +have Bose-Einstein condensation +in the lowest quasimomentum + +state. + +The lowest quasimomentum +state is a superposition + +of all Wannier +function-- I mean, + +the 0 momentum +state in free space + +is a superposition of all +position delta functions. + +The plane wave is delocalized. + +And the lowest +quasimomentum state + +is just completely delocalized +over all Wannier functions. + +But this is nothing +else than the q + +equals 0 quasimomentum +Bloch wave. + +The interesting +question is-- and this + +has led to hundreds if not +more papers in the literature-- + +how do we go from one +limit to the other limit? + +And now you would +say, well, maybe we + +should use what +has worked so well. + +We should use the +Bogoliubov approximation. + +Just assume we +have a condensate, + +replace all those kind of a 0 +operators for the lowest Bloch + +waves. + +However, this doesn't work, +because the interesting thing + +here is to find the +transition from the superfluid + +from the Bose-Einstein +condensate + +to an insulating state. + +The nature of this +approximation is + +that you need N 0 to be large. + +But we're interested when the +condensate wave function turns + +to 0, and in the +insulator it becomes 0. + +So we are actually interested +in the opposite limit. + +And indeed, if you +would ignore everything + +I've just said that +doesn't make sense + +to make this approximation +and make it nevertheless, + +you will find that you never +get the insulating state + +because you've pretty much +eliminated the possibility + +to describe an insulating state +by doing this approximation. + +So I want to show +you now that we + +have to do another mean +field approximation, which + +is actually nice. + +It's very different from this +Bogoliubov approximation, + +but it's also a mean +field approximation + +which will describe our system. + +So the goal is now +that I want to find + +an effective Hamiltonian +which describes + +the transition +from here to there. + +And the important +approximation I will use + +was is the following-- again, +I have to get rid of operators. + +Products of two many +operators cannot be solved. + +And so what I will do is I +will use products of operators, + +write them as average +value plus fluctuations. + +And then when I +multiply that out, + +I take the product of +the average values, + +and I include the +fluctuations in leading order. + +So I take delta A times B +and delta B times A average, + +but I neglect the product +of those fluctuations. + +You can say I neglect the +correlation of fluctuations + +here. + +So this is spelled out here. + +But the sign is important. + +Just look at this equation-- +A delta B plus delta B with B + +plus A average times B average. + +If I absorb A times B by +upgrading delta B to B, + +but I do the same here, +I have to subtract + +1 product of the +two average values. + +It's actually this minus sign +which will play a role later, + +but here you see already that +I will make this decoupling + +approximation-- that I +decouple the fluctuations + +from each other and I +write it in this way, + +there is an +important minus sign. + +OK, so we want to start +in the insulating state. + +And we're going to figure out +how does the system develop + +superfluidity out of +the insulation state? + +And the perturbation +operator which takes me out + +of the insulating +state is tunneling. + +So therefore, the operator which +is responsible for breaking out + +of the insulating +state is the operator + +which induces tunneling +between neighboring sites. + +And the tunneling operator +in this Hamiltonian-- + +remember, the Bose-Hubbard +model had j times B dagger B-- + +this was our tunneling +term-- this involves now + +products of operators. + +And I told you we want to get +rid of products of operators + +to get something we +can easily solve. + +So we use now this +product of operators + +on two neighboring sites. + +And we use exactly this +decoupling approximation. + +So therefore, we replace each +operator by an average value, + +and we neglect the product +of the fluctuations. + +And then we obtain this. + +And I explained to you where +the minus sign came from. + +So now I call this average +value of the operator B l, + +I call the superfluid +order parameter psi. + +I think I could have +chosen psi to be complex, + +and then B l dagger B l +would have complex conjugate. + +But it's sufficient here +to restrict the discussion + +on real numbers, and it +makes the notation simpler. + +So anyway, I introduce that. + +And what happens now +is the following-- + +that I have my Hamiltonian. + +The Hamiltonian had +the interaction energy. + +But the tunneling term +is now very simplified, + +because instead of +tunneling from one site + +to a neighboring +site, the other side + +is sort of absorbed +by the mean field, + +by the superfluid +order parameter psi. + +And therefore, and this +here gives me a psi + +squared term which appears here. + +Trust me, this is just +an identical rewrite + +of the previous Hamiltonian +by using this decoupling + +approximation. + +So what we have gained now +is something really dramatic. + +We had many sites and +tunneling from site to site. + +But if you look at +it now, we simply sum + +the effective Hamiltonian +over site index l. + +So our effective +Hamiltonian is now + +the sum of an identical +Hamiltonian per site. + +The sites no longer +interact with each other. + +Each site interacts with all +the other sites described + +by the mean field by the +superfluid order parameter psi. + +So therefore, our +many-body problem, + +which is still a +many-body problem, + +but has turned into an effective +Hamiltonian for each site, + +because each side has +the same Hamiltonian. + +Colin. + +AUDIENCE: What happened +to the j psi squared term? + +PROFESSOR: This here? + +AUDIENCE: Oh, OK. + +PROFESSOR: OK so I can say +instead of solving for the sum, + +I can just solve for +each site individually. + +And this is now my effective +Hamiltonian for each site. + +Now I want to catch the +onset of superfluidity. + +So I want to get the +system when psi is small. + +And therefore, I can just +ask-- I don't know what psi is. + +It's part of my solution. + +But I'm interested +in the moment when + +psi begins to take off from +0, when superfluidity emerges. + +So what I can therefore do is, +I can regard psi as an epsilon + +parameter, as a small parameter. + +And the psi parameter +comes with an operator V. + +And this operator V is nothing +else than B l dagger plus B l. + +So in other words, +what I'm doing is, + +I'm separating my Hamiltonian +into a Hamiltonian which + +is diagonal in the +quantum numbers + +of the isolating state-- +just one, two, three + +particles per site. + +And psi squared is the Z number. + +Psi squared is also +diagonal in that. + +And now the possibility +of tunneling, + +the possibility of +superfluidity is now + +perturbative in this +term psi times V. + +OK, I don't want to explain, +actually, this expression. + +It just formalizes +[INAUDIBLE] intermediate step. + +When we have the +chemical potential, + +and we raise the +chemical potential-- + +we go from zero to +one particle per site + +to two particles per site. + +And whatever the +chemical potential is + +determines whether we have +one or two particles per site. + +This is just telling me as a +function of chemical potential, + +what is the ground +state of the insulator? + +So now we take this ground +state-- it's actually + +much easier described +in words then + +by this formula-- we +take this ground state + +and do perturbation theory in +our term psi times V. Remember, + +the operator is B dagger +B. And the epsilon is psi. + +So in second-order perturbation +theory, we get psi squared. + +And then V, because B B +dagger, is very simple. + +It only couples one occupation +number N to N plus 1 + +and N minus 1, +because B and B dagger + +destroy or create a +particle per site. + +So therefore, I can +immediately write down + +what this matrix element is +in second-order perturbation + +theory. + +I mean, these are all-- +sorry, it's all defined here. + +I know I'm losing you now. + +Nobody will tell me what is the +difference between U bar and U, + +but it's trivially defined. + +So the idea is we have +the isolating system. + +We do perturbation +theory in tunneling. + +And the perturbative operator +is psi times B plus B dagger. + +The B plus B dagger +matrix elements + +are trivial, because +they admix to N particles + +per site-- N plus +1 and N minus 1. + +And this is what +we've done here. + +AUDIENCE: And the j is +just occupation number? + +PROFESSOR: The j is the +occupation number of our site. + +AUDIENCE: I have two questions. + +So in the bottom equation, what +happened to the psi squared? + +PROFESSOR: Sorry, +this is the sum. + +The psi square is missing. + +AUDIENCE: I guess I +had the same question + +for the equation next +to the green thing. + +Is there supposed to be +a psi squared in there? + +Because originally, there's +a psi squared and an h0. + +PROFESSOR: No, this is the +ground state where psi is 0. + +And now we do +perturbation theory + +in psi V. These are the +unperturbed energies which + +appear in the +energy denominator. + +The wave functions +we are using are + +Fock states-- number +states-- per site. + +And here we couple occupation +number j to all possible N's. + +But because of B and B dagger, +N has only two values-- + +j plus 1 and j minus 1. + +And this is what's given here. + +It's mathematically trivial. + +The notation is more complicated +than the physics behind it. + +But now comes again-- I think I +need five minutes and I'm done. + +But now comes the +interesting physics. + +We have to ask what +are we doing here? + +It's all the mathematical, and +the math is really simple here. + +What we have done is we have +looked at the isolating state, + +and we have done perturbation +theory in psi times B plus B + +dagger. + +And now we get an +energy correction + +which is psi squared. + +And what are we +really doing here? + +Well, you can say +the following-- + +we started with a +hypothesis that we + +have a superfluid state +characterized by psi and psi, + +at the onset of +superfluidity-- is small. + +But now we have +done the calculation + +assuming that there is a psi. + +But now we are turning around +and said have we really + +done the system a favor by +introducing superfluidity? + +In other words, has our +perturbation theory in psi + +lowered the energy of +the state or raised + +the energy of the state. + +So in other words, we've done +a hypothetical calculation. + +Hey, what would the +system feel like if there + +were a little bit +of superfluidity? + +If the system says great, +I've lowered my energy, + +then we know we are in +the superfluid state. + +When the system says no, +I raised my energy because + +of the psi, then the system +has rejected our idea + +to introduce superfluidity. + +So therefore, the question +we are raising now + +is after we have done the +calculation, for what values + +of U and j is it favorable +to introduce a psi or not? + +Now I was expecting the +question of some of you + +that in second-order +perturbation theory, + +second-order perturbation +theory always lowers the energy. + +But remember, this is why I +emphasized the minus sign-- + +we had a psi squared term +which came from that, which + +came from the last term of the +decoupling approximation, which + +had a minus sign. + +And therefore, we +have in psi squared + +one term which came +from this special psi-- + +and I emphasized in the +decoupling approximation. + +And we have a contribution +of psi squared + +which comes from +perturbation theory. + +And the two together can +actually change their sign. + +So what we have right now is +if you describe the ground + +state as a function of psi, +we have our unperturbed energy + +of the Mott insulating +states, and then we + +have a term in psi squared. + +And we should-- and we could, +but we don't-- calculate + +the next order in +psi to the four. + +And it turns out in fourth-order +perturbation theory, + +this term is always positive. + +So what happens now +to the total energy + +when this term A2, which we +have exactly analytically + +calculated-- if this term A2 +is larger or smaller than 0. + +Well, if you have a parabolic +term and a quartic term, + +in this case, both the +quadratic and the quartic term + +are opening up +like in a U shape, + +but here the total energy +turns into W shape. + +And the interpretation +is fairly simple. + +Under those +conditions, the system + +prefers to have psi equal +0, whereas here, it's + +like the system wants to +have a psi parameter which + +is finite, either +positive or negative. + +And whether it's +positive or negative + +is sometimes called +spontaneous symmetry breaking + +between two +degenerate solutions. + +What I'm showing +here is, of course, + +very similar to the +Ginzburg-Landau theory + +of phase transitions, where +you have an effective potential + +and the phase transition +takes place when + +the second-order +coefficient changes sign, + +and the effective potential +turns from U-shaped + +into W-shaped. + +So that's what we have done. + +So anyway, I think this +is a nice problem where + +the interpretation +is, I think, much more + +subtle than the +calculation itself. + +But we've calculated +the phase transition. + +Everything is analytic. + +Here is the analytic +result, which + +I know with very +indigestible notation. + +I followed exactly the paper +by Vanderstraeten, [? Stouff ?] + +and collaborators, which +is posted on the website. + +You can plot this phase +diagram in this way. + +But if you use what +is more common, + +normalize the chemical potential +by U and normalize j by U, + +you get these wonderful +lobes of the Mott insulator + +where you see that, +if you increase + +the chemical potential, you +have N equals 1, N equals 2, + +N equals 3, Mott insulator, +and in between you + +go through superfluid regions. + +However if your +tunneling is larger, + +if your tunneling is too +large, you're only superfluid. + +So this is sort +of the way how you + +derive this rather +rich phase diagram + +of bosonic atoms in +an optical lattice. + +Green is an insulating state. + +And white is the +superfluid state. + +Let me just conclude by +showing a few slides how + +this can be observed. + +So in one case, we have +an insulating state + +with a definite number +of particles per site. + +And here we have +superfluid state, + +which has the normal +fluctuations in number. + +Here's another cartoon picture +of an condensate in the lowest + +Bloch wave function. + +And here you have +localized number states. + +Often, you observe the +transition by taking the system + +and releasing it +in time of flight + +into ballistic expansion. + +If the superfluidity +is coherent, + +the wave function on the +different sites is coherent. + +And what you get is a +multi-slit interference pattern, + +which is a diffraction pattern. + +And you see these characteristic +diffraction patterns. + +It's an in-slit +diffraction pattern + +which characterizes the +coherence in the initial state. + +However if you have a +completely isolating state, + +you have a Gaussian wave +packet on each side, which + +has nothing to do with +the next neighbor. + +And then the Gaussian +wave function simply + +expands in a structureless way. + +And so the transition +from here to there + +happens exactly when +the ratio of U over j + +crosses the value +we have derived. + +There's another +technique of observing + +that which is more recent. + +This is a quantum +gas microscopes + +where you do the same +physics in two dimensions, + +so you have only one plane +where this physics takes place. + +And you can observe atoms +now with a microscope. + +So each green dot +here is an atom. + +If you sort of zoom in. + +And if you now study +the region where + +you go through the superfluid +to the Mott insulator, + +you see that you have +exactly one atom per site. + +If you increase the atom +number, you have an insulator + +with one atom per site. + +And in the middle, +you have state + +with two atoms per site, +which-- for reasons + +I don't want to discuss-- are +color-coded here in black. + +And that sort of +goes on and goes on. + +So you can really +resolve site per site + +the occupation of the +number of atoms per site. + +So I think I'll stop +here with the Bose gases. + +When you think the +Mott insulator is + +the end of the story, all +motion has been frozen out + +and you have one +particle per site, well, + +it could be the +beginning of a new story. + +Because if you use two +different hyperfine states, + +spin up and spin down, we +can talk about spin ordering. + +But this would be a +whole different lecture. \ No newline at end of file diff --git a/Iq8yyEHm_jI.txt b/Iq8yyEHm_jI.txt new file mode 100644 index 0000000000000000000000000000000000000000..d63fb6fa4837f205f9d461794b4d37827a0ef202 --- /dev/null +++ b/Iq8yyEHm_jI.txt @@ -0,0 +1,4626 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +JEFFREY C. GROSSMAN: All right. + +So we are here. + +I'm highlighting +two, because I really + +want to keep talking +about solar thermal fuels, + +mostly because it really +captures a key problem + +that only quantum +mechanics can solve. + +OK? + +So I really want to +hit that home hard. + +Also, because it's the +topic of your next homework, + +and also because I'm biased. + +I'm more excited +about this than this. + +But I want to tell you a little +bit about hydrogen storage + +too, and why I think +that's a perfect problem + +for atomic-scale +computational modeling. + +OK? + +So we're going to do a lot +more of solar thermal fuels, + +picking up where we did +before, and then a little bit + +of hydrogen storage. + +Now, before we do that, +I want to keep blending + +in some reinforcement +of key basic concepts + +that we have touched on, +and we need to make sure + +we feel good about them. + +So we're going to +feel good today + +about energy levels, first +bullet of the outline, + +feeling good. + +It's a good way +to start, I think. + +I didn't need to put +that there, because you + +would have felt good anyway. + +Right? + +But there it is in writing. + +We're going to feel good +about energy levels, + +and then we're going to keep +talking about solar fuels. + +And we'll do a few +calculations, more calculations + +on the nanoHUB together. + +Right? + +Again, no better +way to pass time. + +OK? + +And then we'll talk +about hydrogen storage. + +That's our plan. + +Now, like I said, I want +to keep reinforcing-- + +I did this, and it +put me off balance. + +It's excitement. + +That's a little bit +more than my usual even. + +It's also, I think, +just old age. + +I think sometimes, you +get a little off balance. + +Anyway, now, point is +that I think probably I + +like watch the NBA so +much, because I still + +don't want to give up the +idea that I could someday + +be in the NBA myself. + +So I'm not letting +go of that dream, + +but anyway, I want to go back to +one of my original excitements + +here about materials +design which + +is one of the +things I really want + +to make sure we +capture in this class, + +designing materials +and computers. + +Right? + +So I want to take +carbon, and I just + +have two or three slides here. + +So I want to touch +on what I think + +is a really exciting +example of materials design, + +and you all know this. + +Right? + +You know carbon can do this +and this, and many of you + +know that carbon can do-- + +well, where are my fullerenes? + +Well, there's some nanotubes. + +There's fullerenes inside +of nanotubes, p-pods. + +Right? + +Now, there's all kinds +of forms of carbon + +that there didn't used to +be, or there used to be, + +but we didn't see them, and +we couldn't control them. + +OK? + +And I want to give +you a really, I think, + +interesting analysis of one +thing you can do with carbon. + +OK? + +And then another thing you can +do with it, when you design it, + +when you can do +materials design. + +So this is what we do with +carbon now that we find in oil. + +Right? + +We burn it, and there's 1.73 +megawatt hours of energy + +when you burn a barrel of oil. + +Right? + +I didn't show you this example. + +Did I? + +OK. + +Because I think it's +a really neat one. + +So that's how much energy +is in a barrel of oil, + +and it's a lot of energy. + +That's a really nice-- + +oil is amazing. + +It's like this incredible +energy-dense, safe, + +transportable, storage system. + +Right? + +It's solar powered. + +Right? + +You all know that +it's made by the sun, + +but it's not renewable, +which is a problem, + +but it's a really +beautiful fuel. + +Now, oil has a lot +of carbon in it + +which is what's burning there +and giving you that energy + +release. + +But there are other things +you can do with that material, + +and one thing you can do is +you can make these other forms + +of carbon from the oil. + +In fact, that's how we +make a lot of our plastics. + +OK? + +We make a lot of +plastics using oil. + +If I take 1%, just 1% of the +carbon in these 159 liters + +of oil, just 1% of it, and +I make that into plastic, + +then because I know how to +design carbon to be something + +else, like fullerenes, I can +make polymers and fullerenes + +out of that same element +carbon and put them together-- + +gesundheit, whoever that was-- + +and make solar cells, +new kinds of solar cells, + +in fact, solar cells made +out of mostly carbon. + +If I take 1% of that +carbon that was in here, + +and I turn it into this, +which we now know how to do, + +then I can make really +bad solar cells. + +5% efficient, not so +good, die in one year, + +not so good. right? + +The efficiency goes down. + +Most solar cells, you +get a 20-year warranty. + +This one, one-year warranty, +then efficiency is gone. + +Even in that case, +this solar cell + +over that one year of +really crappy efficiency + +will give me 10,000 +times as much energy than + +by burning the carbon, 10,000. + +Now, these are hand-waving +arguments that are + +back-of-the-envelope +calculations, + +but when you've got five orders +of magnitude to play with, + +things are good. + +Right? + +And this is an example +in the energy space. + +This is why I get so excited +about designing materials, + +and this in particular, this +is only 100 nanometers thick. + +Right? + +The solar cell's +thicker, because it's + +packaged but the active layer, +the part of the material that's + +making the sun turn into +electrons and holes, + +something we're going to talk +about in our next example, + +in a few weeks. + +That part is 100 +nanometers thick. + +That's atomic scale. + +That's the atomic scale. + +You can't pack that many +polymers and fullerenes + +into 100 nanometers. + +Things at the atomic scale and +the quantum mechanical aspects + +of that material are +critical, and designing + +that material is +something you can + +do using atomistic modeling. + +So this is what I mean. + +You want to give elements +completely new possibilities, + +and you can see the +power of doing that. + +It changes the way we know +how to use those elements, + +and I think that's just +a very powerful concept. + +OK. + +Any questions +about that example. + +So that's my little my material +design example of the day, + +if you will. + +We should make like a +calendar, each day a new-- + +OK. + +Now, I want to pause and feel +our oneness with energy levels + +and basis sets. + +So this is, again, going back +to some important key elements + +of the computations, +and then we're + +going to come back to the +calculations and the example + +of the solar thermal fuels. + +OK? + +Now these are things that +we have talked about, + +but they're so +important that I want + +to talk about them again and +make sure there's no questions. + +Make sure that we are +all on the same page + +and know what these things mean. + +OK? + +So I want to give you, +this is my attempt + +at summarizing our beautiful +path to the energy level. + +OK? + +So let's make sure +we're with it. + +All right? + +So it all started back +in the day in lecture one + +with the Schrodinger equation. + +Does everybody recognized that? + +Now, that is the +equation we're solving. + +When you click +Simulate to calculate + +the energy versus separation +in say, I don't know, + +n-2, then the equation that's +being solved in a computer + +is this one, the +Schrodinger equation. + +Now, what are you getting +out of that equation? + +Well, what you're +getting are what? + +These, what are these? + +AUDIENCE: Wave functions. + +JEFFREY C. GROSSMAN: OK. + +Thank you, and why +do I want those? + +What do they tell me? + +AUDIENCE: Probability. + +JEFFREY C. GROSSMAN: OK. + +Yeah. + +The tell me the probability, +and they tell me more than + +that which is what we need +to make sure we understand. + +So you see, solving +that equation gives me + +wave function, and the wave +functions, well, they're waves. + +Right? + +They have some shape to them. + +They may change in time. + +Do we care about that? + +Not in this class, not in +this class, in this class, + +its all time independent. + +So we're doing like a snapshot, +but they may change in time. + +But they certainly vary +in space, and that is psi. + +Right? + +Now, what we talked about +is how these wave functions + +themselves, we don't know how +to draw physical meaning from. + +That doesn't mean that +they're meaningless, + +and this is a really +important point + +that we have to feel good about. + +OK? + +So I'm going to +come back to that, + +but we know that when you square +them, we know what they mean, + +and that's this. + +Right? + +So what are These do you +guys remember what these are? + +AUDIENCE: Orbitals. + +JEFFREY C. GROSSMAN: +Orbitals, such a bad name, + +but anyway, because +why is it a bad name? + +AUDIENCE: Because they +don't really orbit. + +JEFFREY C. GROSSMAN: +Yeah, totally, but anyway, + +these are orbitals. + +So these are those wave +functions squared for what? + +Who knows what-- but +what system is this? + +These are the atomic +orbitals of a hydrogen + +atom, one electron, one proton. + +OK? + +You can solve that analytically. + +Now, so we said, OK, +well, this gives us + +like an electron sitting in +one of these little wiggles. + +OK? + +We said that they +go up in energy. + +They have different energies. + +That's really important. + +Each wave function you solve +for has a different energy. + +Right? + +So you get these functions, and +they have different energies, + +and there it is for +hydrogen. There's + +the energy for hydrogen. It just +depends on 1 over the principle + +quantum number squared. + +Right? + +Remember, we talked +about how it's quantized? + +But these little wiggles, +when you square them, + +they give you the picture of +where that electron is going + +to be, where it's likely to be. + +And we looked at how the +shapes got more complicated, + +and what are these +type of orbitals? + +AUDIENCE: P + +JEFFREY C. GROSSMAN: p? + +And then it goes to other +things, d and then f. + +And then we said, +OK, that's nice. + +That's great, but also there's +this thing called spin. + +OK? + +And somebody remind +me what spin is. + +AUDIENCE: Property +of the material. + +JEFFREY C. GROSSMAN: Property +of what thing in particular? + +Yeah? + +AUDIENCE: It's some +intrinsic angular momentum + +that a particle has. + +JEFFREY C. GROSSMAN: OK. + +AUDIENCE: Regardless +of its motion. + +JEFFREY C. GROSSMAN: +And if that particle + +happens to be an electron, +what are your options? + +AUDIENCE: In the first one? + +JEFFREY C. GROSSMAN: Yes. + +AUDIENCE: Plus or minus. + +JEFFREY C. GROSSMAN: +Plus or minus. + +It can only be-- + +or as we like to say +up or down or as we + +like to draw this or that. + +Lots of ways of doing this, +but I think you get the point. + +And then we talked +about poly which + +gave us rules for how +electrons can be together + +in one of these orbitals. + +OK? + +So you have wave +functions that wiggle. + +We don't know how to +interpret what they mean, + +but we know that their square +gives you the probability + +distribution of that electron. + +And we know that +these electrons also + +have another important quantity +associated with them, a spin, + +and the spin can only be one +of two values, up or down. + +OK? + +That is the information we +need to go to energy levels. + +OK? + +To this point, this is a +review, but it's about to be-- + +well, maybe +something some of you + +know, but it's about to +be a little different. + +OK? + +So I want to make sure +we all understand this. + +Once I know that you can +have two kinds of spin, + +and once I know that you get +energies out of this equation, + +then the answer to +the energy levels, + +to what energy +levels are, is there + +are these things that you fill. + +There are these things that +you fill with electrons. + +How do you fill them? + +I keep blocking the screen, +but it's fun to go in there. + +It makes me feel +important maybe. + +I don't know. + +Never mind. + +How do you fill them? + +I'll use this. + +Oh, yeah. + +What do you do here? + +What's going on? + +I want to fill these orbitals. + +Do I fill this one + +AUDIENCE: You start +at the lowest end + +and work to the highest. + +JEFFREY C. GROSSMAN: +Yeah, and when do I stop? + +AUDIENCE: When you +run out of electrons. + +JEFFREY C. GROSSMAN: When +you run out of electrons. + +How many electrons did I have? + +AUDIENCE: 29. + +JEFFREY C. GROSSMAN: It depends +on the atom or molecule which + +is where we are now or solid. + +Now, that is really +in a way-- the reason + +I'm focusing on it is this +is the key quantum mechanical + +nature thingy, +property of materials, + +I want you to come away with +being able to understand + +and calculate in this class. + +OK? + +It's these energy levels. + +This is the most important +thing I want you to come away + +with from this class. + +Why? + +Well, we can calculate +other things, + +and I've talked about that. + +We can calculate energies. + +We can calculate +binding energies. + +We can calculate +all kinds of things, + +but these energy levels are +purely quantum mechanical. + +Right? + +There where those electrons +want to be in energy, + +and they matter so much to +the properties of materials. + +So I want to focus on +these and connect them + +to real exciting problems. + +OK? + +And make sure that +you understand + +where they come from and +also how to calculate them + +and what they can mean. + +So that's where we are. + +So that's why I keep +drawing things like this. + +You see me just drawing this. + +Right? + +Now, what did I draw? + +I don't know. + +I drew a bunch of levels. + +Right? + +If I'm a little more +careful, and I do this, + +now what am I drawing? + +What is that? + +AUDIENCE: Energy diagram. + +JEFFREY C. GROSSMAN: +Energy diagram. + +OK, good. + +What is it though? + +Do we know? + +AUDIENCE: Like there's +no electrons in there. + +JEFFREY C. GROSSMAN: +OK, and it's + +the solution to which problem? + +Actually, this is +infinite square well. + +So that's not the +hydrogen atom, but those + +are the energy levels +you get for the solution + +of the hydrogen atom. + +OK? + +Now, if I ask you what this +is though without putting + +any electrons down, we don't +know, but what if I do this? + +Now, what is it? + +Hydrogen, what about now? + +AUDIENCE: Lithium. + +JEFFREY C. GROSSMAN: +Lithium, what is this? + +Oh, I love this one. + +AUDIENCE: Carbon. + +JEFFREY C. GROSSMAN: +Carbon, carbon, + +it's a beautiful material. + +I love carbon. + +OK? + +I almost feel like you +need a little moment. + +When you draw the +energy levels of carbon, + +you need a little +moment of respect. + +Now, but you see, +this is what we did. + +We solved for these wiggles. + +We got energies, and +we put them in order + +from lowest to highest. + +And then we said how many +electrons do we have? + +Six, OK, fill them, +and then there + +are rules that we talked +about about how you fill them. + +Now, why am I +going through this? + +Well, because that is only +good for what kind of material? + +That is only a correct picture +for what kind of material? + +Atoms, that's an atomic picture. + +We solve for the atom, and +this is true-- and remember, + +I said that we can solve +for the hydrogen atom + +and see the whole +periodic table. + +Right? + +Powerful stuff, but +this is only an atom. + +These are how you would fill +the energy levels of an atom, + +and we've talked about this. + +But see now, we're going +onto other things, where + +you bring atoms together, +and you form molecules. + +This is not a chemistry class. + +So I'm not going to spend +a lot of time telling you + +about sigma orbitals, pi +orbitals, bonding orbitals, + +antibonding orbitals. + +That's not what +we're about, but I + +do need you to understand that, +when you bring atoms together, + +the orbitals from those +atoms come together + +and form new orbitals. + +They form molecular orbitals. + +OK? + +Now, in this case, you're +seeing the H2 molecule, + +and this is from this website. + +There's lots of great +websites that talk + +about molecular orbital theory. + +OK? + +And in this case, you +brought two s electrons + +together, see, from a hydrogen +atom over here and a hydrogen + +atom over there, and they +drew those energy levels. + +And then they brought +them together, + +and it turns out, when +you bring to 1s levels + +together to form a molecule, +you get two new levels. + +Right? + +And the chemists love names, and +so they gave this one a sigma + +1s, and that's a sigma star 1s. + +Those are just two +new levels that + +are formed, when you bring +these atomic levels together. + +Now, all the same rules-- and +one of them, ah, two points-- + +one of them is a +bonding orbital. + +See, this actually looks like +I brought two circles together, + +and they overlapped. + +That's a bonding orbital. + +OK? + +Another one of them, though, +is an antibonding orbital. + +All right? + +And an antibonding orbital +is higher in energy. + +So it's going to come up higher. + +Its energy is going to be +higher than the bonding orbital, + +when you bring two +orbitals together. + +when you bring two +orbitals together. + +And often, an +antibonding orbital + +will actually have +a node, which means + +there's zero chance +of any electron being + +in between, exactly in between. + +That doesn't sound +very binding-y. + +Right? + +Doesn't have a lot of +appeal for bonding, + +if there's like a +plane of no existing. + +Now, why would that be possible? + +Doesn't it seem +from this picture-- + +I took to 1s orbitals, and +I brought them together. + +Right? + +How can I get a +node between them? + +AUDIENCE: Is it [INAUDIBLE] + +JEFFREY C. GROSSMAN: Not quite. + +What is it? + +AUDIENCE: Coulomb repulsion. + +JEFFREY C. GROSSMAN: Yeah. + +It is actually. + +It does have to do +with Coulomb repulsion, + +but there's something +more basic here at play. + +How is it that I can +bring two spheres, + +probability spheres +like this together + +and have two orbitals +that form, one of which + +has a node in between, +and one of which is + +like really nicely happy bound. + +AUDIENCE: [INAUDIBLE] + +JEFFREY C. GROSSMAN: +Not quite, any other? + +Yeah? + +AUDIENCE: It looks like the +infinite square well there. + +You've got the ground state +that doesn't have any nodes + +and then the first excited +state does, the same deal. + +JEFFREY C. GROSSMAN: Exactly. + +Well, so that's exactly right. + +We're not bringing together +probability distributions. + +OK? + +That is not the right +way to think about it. + +I won't stand in front anymore. + +We're not bringing together +probability distributions. + +We're bringing together +wave functions, + +and then when those +come together, + +they form a probability +distribution or two, + +in the case I just showed you. + +And we all know that, +when waves come together, + +they can do what and what? + +AUDIENCE: Construct +and deconstruct. + +JEFFREY C. GROSSMAN: Exactly. + +They can construct, and they +can deconstruct one another. + +Sounds like they're +going to have + +like a philosophical discussion. + +So that's what's happening. + +We're bringing the +wave function together, + +when we bring atoms together +and molecules together. + +We're bringing +their size together. + +Oh, size, you can't get away +from size being so important, + +and we're solving for +the collective psi. + +And when you bring waves +together, they have phase, + +and they can form constructive +and destructive interference, + +as we talked about in +lectures one and two, + +and that's what's +happening here. + +And then you square those, +and you get new orbitals + +which have those properties. + +OK? + +So this is the simplest +example which is H2 molecule, + +and then we fill those orbitals. + +And when we fill these +orbitals, when we draw them + +for a molecule, very often, +I'll lose this notation, + +because there isn't-- + +and I'm not going to go +through this notation, + +mostly because I can't +remember past sigma and pi. + +But there's a whole +lot of notation + +out there for +molecular orbitals, + +and it depends on the +symmetry and the group + +symmetry of the molecule +you're working with, + +and there are rules +and all that stuff. + +But all we're going +to need in this class + +is to know that, when +you have a molecule, + +and you calculate +this wave function + +which gives you the wiggles. + +And then you square it, +you get the distributions, + +and that helps set +the energy levels. + +It tells you where those +energy levels are going to be, + +that will just draw +them like this. + +Right? + +Now, this is how +I'll draw molecules, + +the energy levels of molecules, +and again this is it. + +This is one of the most +important properties + +I want to focus on, +because this is everything. + +This is where those electrons +are in energy space, + +and I can plot them. + +I can look at their energy, +and there's all kinds + +of important information here. + +OK? + +And so what this +means is usually I'll + +leave a space here. + +Does anybody know +what this is called? + +AUDIENCE: Gap. + +JEFFREY C. GROSSMAN: Right. + +This is the gap, +because that's how many + +electrons I had in my molecule. + +Not my atom, but in my molecule. + +So I do the same thing. + +I calculate energy levels, +I fill them up, and I stop. + +I apply some rules, +like you wouldn't + +have one level with two +electrons up, Pauli exclusion. + +Right? + +And then I stop, +and then there's + +another level beyond that. + +Oh, that's important. + +So we're going to +talk about that today. + +There's another level beyond +that that's not filled, + +but the distance in +energy between these + +is called the gap, and +it's really important. + +And the energy gap is +what determines all kinds + +of properties about a material. + +It determines how +it absorbs light. + +It determines how +it conducts charge. + +It can determine things about +its magnetic properties, + +certainly transport properties. + +And what's going to +happen, and that's + +why I really want +to make sure we all + +understand this for a molecule. + +What's going to happen +is, when we go to solids-- + +on Thursday, we're +going to start talking + +about moving to solids-- + +this is going to happen. + +These are no longer +simple lines. + +These go like this, +and that's really cool. + +That happens because +you're putting them + +in a periodic arrangement. + +That's called a band structure. + +It doesn't happen for molecules. + +They're just little flat +lines, like they are in atoms. + +OK? + +So are we all good with this? + +Are there questions? + +Energy levels, +energy levels, need + +to know about energy levels. + +No questions? + +Yeah? + +AUDIENCE: So when you +put up every central gas + +and you calculated +all the total energy, + +if you like have big molecules-- + +JEFFREY C. GROSSMAN: Yeah. + +AUDIENCE: --you got huge gap and +it's harder to identify that. + +JEFFREY C. GROSSMAN: Which one? + +What's harder to identify? + +AUDIENCE: Ammonia. + +Because if you have one +more unit, for example-- + +JEFFREY C. GROSSMAN: One more. + +AUDIENCE: --some group. + +JEFFREY C. GROSSMAN: OK. + +So you put an electron here? + +Or what do you mean? + +AUDIENCE: So when you +calculated the wave function-- + +JEFFREY C. GROSSMAN: Yeah. + +AUDIENCE: --how did you know +the electron wave function + +for this type of ammonia? + +JEFFREY C. GROSSMAN: +Well, that's-- + +Yeah. + +So that's where really +lecture three covers that. + +Where basically, you need +to use an approximation + +to the Schrodinger equation, +and that approximation + +that we're using +in this class is + +called density function theory. + +But then you simply what +goes into that equation + +is the approximations +you choose, + +and the positions of the atoms +and the number of electrons. + +And once you have +that, you basically + +are solving for the psi. + +You're solving for these. + +Right? + +And you get them and +their energies out, + +and it's in the outputs +of the nanoHUB runs. + +OK? + +Now, one last thing before +we go back to solar fuels + +that I want to make sure +we feel our oneness with + +are these basis functions. + +So this is a slide from another +lecture, an older lecture, + +but I just want to +be sure we understand + +what we're doing here. + +OK? + +So we said we needed to +make size for our materials. + +We need the code to give us psi. + +Now, for a hydrogen atom, +these are analytic functions. + +Right? + +They're like sines, cosines, +but for more complex material, + +a complex atom, they +can look like this. + +They can be really complicated. + +OK? + +So but a computer +can't just draw lines. + +Right? + +A computer can't do that. + +It needs to have some +mathematical representation + +for that function, and +that's what a basis set is. + +But as I stressed +last week, this + +is a new sort of not +a problem, but it's + +a parameter that is not present +in classical simulations. + +But it's one you have to +be very carefully aware of, + +and you have to know +when you've converted it. + +OK? + +And the question +came up last week + +of when is a basis +set converged? + +OK? + +And what do I mean? + +Well, I can make a +basis out of anything-- + +Gaussians, exponents, +plane waves. + +I can make a basis +out of wavelets + +which are really interesting +hat-like functions. + +But I can take any function, +and if I add enough of them + +in the right places, and they +have the right width and size, + +I can recreate a curve. + +That's what we're +doing, but I want + +to have as few as possible. + +OK? + +So this is a basis set +study that somebody did + +and randomly put on the +web, which I randomly + +found and didn't credit, +which I should have. + +Anyway, this is the +number of basis functions + +going this way, number +of basis functions, + +and that's the energy. + +And you can see that the +energy is going to change, + +as you increase the +number of basis functions, + +and there's this thing +called the basis set limit. + +Sometimes it's called the +complete basis set limit, + +and that complete basis set +limit is basically just saying, + +hey, I've represented +my wave function + +now numerically correctly. + +So infinite number of basis +functions should give you that. + +We don't have +enough computer time + +to have that many basis +functions, because it + +gets really long and slow. + +So we don't do that. + +Usually, we do calculations out +here, and maybe we extrapolate. + +OK? + +Or we just do a few +cases, and we say, + +well, my results are converged. + +But when is a basis +set converged? + +It's a really important +point of quantum mechanical-- + +hey, that would be like +a good quiz question. + +Right? + +Like it's a really +important part of quantum + +mechanical simulations are +always a quiz question. + +It's not a bad one. + +Is it converged here, +or is it converged here? + +You know what answer +I'm looking for. + +AUDIENCE: Depends +on the problem. + +JEFFREY C. GROSSMAN: It depends. + +I love that answer +for this class. + +It depends, because +here, I'm plotting + +the total energy of +the whole system, + +but is that what I want? + +Is that what I'm calculating? + +I don't know, maybe, but what if +I'm actually calculating this? + +What if I'm calculating the gap +between the highest occupied + +and lowest occupied level? + +Well then, I should plot +that versus the basis set, + +and that, this line, the total +energy may converge like this. + +Whereas, if I do the gap, it +kind of goes-- maybe it's here, + +and then I get +another value here, + +and then everything is fully +converged all the way in. + +So the gap value +converged there. + +You don't know. + +Different properties will +converge differently, + +and you start to +get a feel for it, + +as you do more calculations. + +I'm not expecting you to get +to that point in this class, + +but I want you to +understand this. + +It's really important. + +OK? + +So basis sets must be converged. + +That's one point. + +This can lead to big tables. + +Chemists love big tables. + +So it's actually a perfect fit. + +So you see papers like this. + +Oh, you can go to bse.pnl.gov, +and let's see, maybe I can just + +go there really quickly. + +And you can see, +oh, look at that. + +There's the nanoHUB. + +We're coming. + +We're coming, and look at this. + +Oh, this is beautiful. + +See, many basis sets have +been made over the years. + +Right? + +And so here, they are. + +Look at all these basis sets +for different-- and you see, + +I can scroll down here. + +Look at these basis sets. + +You have a few of these to +choose from in the nanoHUB, + +but look at how many there are. + +These are all +published basis sets, + +and you can go to +a place like this. + +And you can click on one, like +3-21G*, and you can click on-- + +well, I don't think that-- + +and you can say what +code am I going to use? + +Right? + +And then, you can say get the +basis sets, and there they are. + +And there are the papers, +where basically, they're + +trying to say what is the +fewest number of Gaussians + +that we can use to +represent these atoms? + +So basis sets are fit to +atomic orbital wave functions. + +OK? + +And this is just a +certain form, where + +you have the exponent +of the Gaussian + +and a coefficient +of the Gaussian. + +And I'm not going +to go into details, + +because we don't need them. + +OK? + +There's a lot of +work on basis sets. + +There's also a +lot of papers that + +were published in the 1970s +and also '80s using basis sets, + +like this, that show +really good answers using + +like Hartree-Fock theory or +density functional theory + +even but for the +completely wrong reason. + +Because they used a level of +theory that wasn't accurate + +and a basis set that +wasn't converged, + +because the computers couldn't +go to larger basis sets, + +and so the errors canceled. + +So there are many papers +with really nice agreement + +with experiment from theory +that are complete nonsense, + +because they're using very +inaccurate theory and really + +bad basis sets. + +And so the errors cancel, and +you get beautiful results. + +It's something that +we need to be aware of + +and understand in this +class, but we're not + +going to go into great detail in +all these different basis sets. + +But you can go there, +and there's just a lot + +of information there. + +And you can play around, and you +can make big tables like this. + +I don't recommend +that you do this. + +But this was a study, this +is like the kind of thing-- + +I think that some people +really like big tables. + +This one goes on and +on and on, by the way. + +It never stops. + +It almost never stops. + +And you see, different +levels theory here. + +These ones we +haven't talked about. + +That's LDA, Hartree-Fock and +then different basis sets. + +You see? + +And some property, +the binding energy + +and some other properties +that they care about. + +OK? + +Yeah. + +Not expecting you +to do that, but I + +want you to be aware +of how big of a concern + +this is in quantum +mechanical calculations. + +Any questions about basis sets? + +Basis sets. + +The last theory +point, last question + +I want to ask, so we +asked, with basis sets, + +how do we know when +we're converged? + +Well, it depends. + +When you add more basis +functions or do a larger basis + +and things don't +change, your converged. + +But there's another +bigger question, + +which is how do we know when +the calculation is right, + +that we talked about here. + +Now, this is very +important, and it + +goes to the point I just made. + +Just because you +agree with experiment, + +if you're not doing your +calculations carefully, + +it can be still dangerous. + +OK? + +But let's suppose that you +have done your calculations + +carefully, and you have +converged your basis set. + +And you have checked everything +else about your code, + +and you're asking +the question of which + +of these structures of carbon-- + +remember, I really like carbon. + +Which of these three +structures-- a ring, + +a kind of bowl, or a cage-- + +gives you-- is most +stable for 20 atoms? + +That's a pretty simple question. + +Right? + +This is the question I asked +as a second-year grad student, + +a few years ago now. + +Who laughed? + +Sam? + +And it was really +cool, because see, + +you could try one +level of theory + +and work really hard to +converge it completely. + +And you'd get, for +example with LDA-- + +something you can +do on the nanoHUB-- + +you would get that the cage, +this guy, is the lowest energy. + +This means the most stable. + +And then you would do another +level of theory, Hartree-Fock + +or this other thing +that you also have, + +this is called the GGA. + +It's another flavor of +density function theory, + +and you would get +exactly the opposite. + +You would get that the +ring is the most stable, + +and the cage is +the least stable. + +So what's going on? + +What's going on? + +Two different DFT +functionals gave me + +completely different answers, +and I've converged everything. + +AUDIENCE: Two more functionals. + +JEFFREY C. GROSSMAN: +Two more functionals. + +Now, that's actually +a really good idea, + +and it's actually +what people do. + +OK? + +In fact, you see, if you go to-- + +I think I left +this web page open. + +Here's one of the +codes that does + +density functional theory +and other quantum chemistry + +calculations. + +It's called Gaussian. + +And if you look in +their 2009 version, + +this is a code you +have to pay for. + +There's lots of codes +that are free, by the way. + +NWChem, if anybody wants to +play with a code, download it, + +that does quantum +chemistry, that's + +a pretty darn good one that's +free which you can download, + +and there are others. + +I'm happy to provide a list. + +But look at the +number of functionals + +you have to choose from. + +OK? + +Here's a little bit +about density functional + +theory and the methods, and +then here are the functionals. + +exchange functionals. + +You see S, XA, B, PW, G96, PBE. + +That's one of the +ones on the nanoHUB. + +Right? + +And correlation functionals, +VWN, LYP, B95, and so + +what you wind up getting-- +and then it goes on, + +standalone functionals, +hybrid functionals. + +OK? + +Here's some more. + +User defined functionals, you +can actually make up your own. + +Right? + +So here's a short list +of some of the keywords + +you can enter and get +different functionals out. + +So now, what do I do? + +AUDIENCE: All of them. + +JEFFREY C. GROSSMAN: +All of them. + +Well, sadly, I think +some researchers do that. + +So here's the broader point. + +OK? + +Density functional theory is +an approximation in the way + +that we use it in our codes. + +The actual theory +itself could be exact, + +but the way that it +has to be implemented + +requires this +approximate functional, + +as you learned in lecture three. + +OK? + +What functional do I use? + +Well, some of these +have been well tested + +for broad classes +of materials and are + +known to do well for certain +properties, certain materials, + +and known to do not +as well for others, + +but it's mostly empirical in +terms of our understanding. + +It's because it's been +tried for many systems. + +OK? + +And so in a way, +we're a little bit + +back to the classical world. + +In the sense that +density functional theory + +is a beautiful theory, +but to make it practical, + +you have to make +approximations that make it + +so that you have almost +an empirical nature to it, + +or a semi-empirical +nature which is what you + +have in classical force fields. + +Right? + +In classical force +fields, the potential + +is as good as the +complexity of the potential + +and what you fit it to. + +Right? + +Density function theory is, +I think, much more powerful, + +in the sense that +you can really solve + +for the electronic +structure, but we + +have the same kind of problem +in density functional theory. + +So the functionals that I've +given you on the nanoHUB + +are some of the +most popular ones, + +but you always +need to be aware-- + +[NON-ENGLISH]---- of the fact that +we're making an approximation. + +And yes, one way to check +is to try two functionals, + +and if they don't disagree +too much, you may be OK. + +That's not the most +gratifying way to do it. + +Another way would be to +compare with experiment, + +and that's actually the +most gratifying way. + +Once you converge +everything else, + +if you're functional +agrees with experiment + +for the kind of +problem you're trying + +to solve, then that's a pretty +good indication that it's + +an accurate solution to +the Schrodinger equation, + +but you are making +a approximations. + +OK? + +And that is something +that we won't-- + +as you can see, I don't +give you much options + +on the nanoHUB, because I +don't really want to go there, + +but I do want you +to be aware of this. + +We are not solving +quantum mechanics exactly. + +We cannot, and with +density functional theory, + +there are some systems. + +So in my graduate days, +I worked on a method + +that goes beyond density +functional theory inaccuracy. + +So it's a very accurate method, +very slow but very accurate. + +And so I was +purposefully looking + +for systems where DFT fails, and +I was very happy with this one, + +where you basically +don't know the answer. + +You can try +functionals, and you'll + +get all kinds of +different results. + +So the only thing you +can do in that case + +is go to a higher +accuracy method. + +OK? + +What I found out is +that this method here + +is the most accurate one, that +actually none of the functions + +were right, and the bowl +was the most stable. + +So it's pretty cool. + +It was exciting. + +What can I say? + +I was a physicist at +the time, so you know. + +I won't say anything more. + +OK. + +Now, let's go back to our +first application example. + +Does everybody remember +this from last week? + +OK. + +So let me make sure we know why. + +OK. + +I want to make +sure we understand + +why this is such an important +problem for quantum mechanics. + +OK? + +So sun shines on a molecule, +the molecule changes shape, + +and that changed shape +is a higher energy. + +So if you draw the +reaction, if you + +draw the reaction +coordinate for this system, + +It looks like this. + +OK? + +So that would be the trans +state and the cis state, + +and this is the higher +energy that that forms, + +and it stores that much +energy in the molecule. + +OK? + +Now, what we found +is that there's + +all these molecules +that do this, + +but they're not very +good solar fuels. + +OK? + +So there's lots of +them that do this trans + +to cis photoisomerization. + +So the sun makes it go, or light +makes it go, from one state + +to another. + +None of them are good +solar fuels on their own, + +but we found this way of making +them in general into good ones. + +And this is a slide +I skipped last week, + +so I want to just very +quickly explain this again. + +Because it's really +important to understand why + +we're so excited about this. + +If you put these molecules +that switch back and forth + +onto a template, and the +template can be anything, + +but here it's a nanotube. + +But if you put them onto it, +and you covalently bind them-- + +that means you attach +them really strongly, + +so they're not +going to come off. + +Then, what you've done is +you've packed them in a way + +that they're not +able to get out of. + +So you've packed them +together, and they're not + +allowed to get out, because +they're covalently bound. + +Some self-assembly +work is weakly bound. + +Some is not. + +Here, it's really +strongly bound. + +So they're really forced +into this packing. + +Now, what does that mean? + +Well, look up here for a minute. + +It's a little busy, +but look at that cyan + +curve, the light blue. + +This is the spacing that they're +packing on on this template. + +This is it, 4.2 angstroms. + +OK? + +And that's also exactly the +minimum of that molecule, + +when it's in the T state, here. + +When it's in the T state, +it's happy at that spacing. + +It's happiest. + +Right? + +But when it's in +the cis state, you + +see the cis state has +a different spacing + +that it wants to be at. + +That's the red curve. + +Right? + +These are the +kinds of curves you + +should be getting in your +homework for problem two. + +That's the curve +for the cis state, + +and you can see that it's a +happy place is much further + +out, but it can't +be much further out. + +It does not have that +flexibility anymore. + +So you've constrained +it to always + +be in the trans, happy place, +in terms of its spacing. + +Now, what that means is that, +you can see right away, what + +that means is that, when +it's in the cis state, + +the energy of the cis state +is going to be higher. + +So already, what you've done is +you've made this state go up, + +because you've sterically +inhibited it just + +by forcing it to be this +close and never further apart. + +In the gas phase or in solution, +when it goes back and forth + +between trans and cis. + +It's always going to +find its happy place. + +They're not going to worry +about this, but here they can't. + +But as I mentioned last week, +much more importantly even, + +when you're in this highly +confined geometry, this highly + +constrained rigid packing, +what you can do now + +is you can play +chemistry between them. + +So I can actually +create functional groups + +on these molecules that +bond them to each other + +and to themselves +in different ways, + +depending on whether they're +in the cis or the trans state. + +OK? + +And what that does +is that allows me + +to lower this and lower this. + +That's the key. + +OK? + +So now, because the +key is, remember, + +goal is to increase +this and this barrier. + +Going back, we want to be +able to tune it separately. + +And you can see that, if you +just look at this reaction + +coordinate, if I +increase delta H, + +it looks like I'm going +to probably decrease + +the activation barrier +which is not a good thing. + +Because that's related to the +stability of the fuel, when + +it's charged, the lifetime. + +These molecules +on their own last + +in the charged state +for a few minutes. + +That's not very useful. + +So what we'd like to do is +to be able to change both, + +and this trick +allows us to do that. + +We push this up from +steric inhibition, + +but we pull it back +down from reactions. + +We pull this, from interactions, +we pull this down even more, + +because we can customize +the interactions that + +happen between these molecules +and within the molecule. + +So that's the key. + +That's the magic sauce. + +Right? + +Now, all that is fine, +except that, as I-- + +OK. + +So we have this new +class of materials + +we're very excited about. + +We're making them in the lab. + +We're designing +them on a computer. + +They're going to save the +world, or maybe they'll + +just de-ice windows, but +anyway, that's very exciting. + +Now, all of that can be done +using classical force fields. + +You can calculate +delta H. You could + +try to get a good model of +potentials for these molecules. + +You could maybe try +different potentials + +and see when it agrees with +experiment and all that + +and try to explore this phase +space using classical force + +fields. + +That is accessible. + +You may not-- gesundheit-- +you may not be accurate. + +You may have some +worries about validating + +the potentials and +all that, but you + +can do this with +classical force fields. + +You can get energies as a +function of these twists + +in the bonds and try to +engineer it this way, + +but you cannot talk about +the optical properties. + +You cannot do that using +classical potentials. + +You need the electrons, and this +goes back to our energy levels. + +OK? + +So now, it will come +in to play here. + +We're going to go +back to energy levels. + +You see, I can make +a really dense energy + +fuel, a really highly +energy dense fuel, + +but if it doesn't absorb +the sunlight efficiently, + +then I can never charge it. + +Right? + +So that's a critical +part of this. + +If it doesn't absorb sunlight +well, it's useless to me. + +OK? + +Now, so this is the thing +that we've been talking about, + +but that part can be looked at +with potentials, if you wanted. + +This part here, where you +absorb the light, cannot. + +So here's the light that +comes down to Earth. + +Right? + +We talked about this. + +That's the solar flux. + +And the key point here is that-- + +I keep that? + +We don't need that anymore. + +The key point here is that those +molecules have energy levels, + +like this and like this, +and they have a gap. + +Right? + +These are what we call occupied, +and these are unoccupied. + +Unoccupied levels, +occupied levels, + +I just don't want +to draw the arrows, + +and that's the energy gap. + +Now, why does the energy +gap matter with respect + +to this picture? + +Yeah? + +At the same time-- + +one, two, no. + +Go ahead. + +AUDIENCE: Because +all the absorption + +are at certain frequencies-- +or certain light + +coming in at frequencies +with great enough energy that + +surpass the energy gap. + +JEFFREY C. GROSSMAN: Why? + +That's really good. + +That's exactly right. + +AUDIENCE: So it's too low. + +It's not enough +energy to shut it off + +from occupied to unoccupied. + +JEFFREY C. GROSSMAN: Yeah. + +AUDIENCE: I mean, +too low of energy. + +JEFFREY C. GROSSMAN: Too +low of an energy, right? + +So this is energy going-- + +this is wavelength +going that way. + +So energy goes this way. + +OK? + +Right? + +So there is going to be some +minimum energy below which + +you can no longer absorb light. + +The molecule is transparent. + +That is the energy gap. + +That's this energy gap here. + +Any energy that that +molecule receives + +that's from those photons-- + +and this is the energy. + +Wavelength, as we know +same, as the energy. + +Any photons it receives +from the sun that's less + +than this just go right past. + +They cannot get absorbed. + +If I don't absorb a +photon, I don't do this. + +I don't switch. + +OK? + +So this is important. + +Now, the question +is what do I want? + +Well, do I want the material to +have a very high gap or a very + +low gap? + +Out here would be a +very low energy gap, + +and over here, it would +be a very high energy gap. + +What do you guys +think I want here? + +How would I get-- and I'm +going to collect energy only + +above the gap. + +So if my energy +gap is here, it's + +only going to be this part +of the sun I can collect. + +So where do you think +I want my gap to be? + +Over here? + +That's definitely +what you would think. + +Why not just make this +material have almost no gap? + +Right? + +If it had almost no gap, then +if this were the gap, then + +any little bit of sunlight +would excite electrons up, + +and you'd absorbed the photon. + +Why is that not a +good solar fuel? + +AUDIENCE: They fall easily. + +JEFFREY C. GROSSMAN: +Say that again. + +AUDIENCE: They fall +back down easily. + +JEFFREY C. GROSSMAN: Well, they +certainly could fall back down, + +and actually usually, they'd +be absorbed say up here, + +and they'd usually trickle +down to here anyway + +to the LUMO state. + +That's called thermalization. + +They could also fall back +down to the homo state + +and re-emit a photon. + +That's absolutely right, +but there's another reason. + +AUDIENCE: Lower energy density. + +JEFFREY C. GROSSMAN: Yeah. + +Why? + +AUDIENCE: There's a band +gap in the partial delta H. + +JEFFREY C. GROSSMAN: Yeah. + +That's it. + +So what are we doing +in storage materials? + +What are we doing with +electrons in batteries, + +in solar thermal fuels? + +What are we doing +with those electrons? + +AUDIENCE: Storing them. + +JEFFREY C. GROSSMAN: +We are storing them. + +Yes, but what are we +doing to make them-- + +what are we doing +when we convert them? + +Maybe I should say it that way. + +Same thing happens +in a solar cell. + +I'm doing something +to these electrons. + +AUDIENCE: Putting +them on a shelf. + +JEFFREY C. GROSSMAN: Yeah. + +You know I love that analogy. + +Yeah? + +It's like pumping hydro. + +Hydro pumping is one of +the best technologies + +we know of to store energy. + +It's even creating a little +stir here in the third row, + +because he has read +the reports, and he + +knows that there are +certain areas where + +that's the only +game in town, pumped + +hydro, a beautiful technology. + +It works. + +You pump water up a hill. + +When you got too much +energy, and you let + +it roll back down +when you need it. + +Right? + +Now, that's all we're +doing with electrons. + +That's it. + +It's the same exact thing. + +We're pumping +electrons up a hill. + +We're using light to do it here. + +For a battery, when you +plug your electric car + +in, you're using current +and electrons, potential, + +voltage to do it, but you're +driving electrons up the hill. + +And then you're trying +to keep them up there, + +and then let them come +back when you need them, + +when you need them +to release energy. + +OK? + +Now, if my gap is +really low, you + +see, the hill, it's never +going to get to the top. + +Here's my hill. + +OK? + +If my gap is only +this much in energy, + +then I'm just going +to roll around here, + +and I'm never going to +get any amount of storage. + +Right? + +So you want this to be +as large as possible, + +because that's how +much energy you store. + +But the gap can't be +any smaller than this, + +or you're not going to give +those electrons enough energy + +to get up the hill to go there, +so the material can go there. + +Yeah? + +AUDIENCE: So let's see +you have some material + +with some small +gap, and you just + +have it exposed to sunlight +and then compare it + +with some material +with a large gap. + +Wouldn't they both on average +collect the same number + +of high-energy photons anyway? + +JEFFREY C. GROSSMAN: Yes. + +AUDIENCE: So with +the low-gap material, + +you'd get some with height +that collect higher-- + +JEFFREY C. GROSSMAN: +Great question. + +AUDIENCE: High energy +photons, and then they + +have some excited state. + +And then the ones +with the high gap + +will also have +that excited state, + +but the ones with +the low gap will also + +have these lower, +excited states. + +JEFFREY C. GROSSMAN: Yes. + +Yes. + +AUDIENCE: On top of that? + +JEFFREY C. GROSSMAN: +It's a great question, + +and what you're talking +about is such a cool idea + +in solar PV called hot carrier. + +What you'd like to do is get +those excited, really high + +energy electrons +out in solar cells, + +before they come back down. + +In this case, they +come back down. + +See in this case, +they thermalize, + +and the reaction happens in +the lowest excited state. + +But it also happens +in solar cells, + +because there are no hot +carrier solar cells today. + +It's a great theory. + +It's a great idea. + +So this is the idea, and +there's a lot of active research + +in this area. + +And it's basically the +idea of multijunction cells + +which are cells that work, and +in fact, the highest efficiency + +solar cells to date +are multijunction, + +triple-junction solar cells. + +Where basically, you have +different band gaps together, + +and those different band +gaps do exactly what you say. + +OK? + +They let you take some +electrons out here, + +and then you have another +material with a higher gap, + +and you can take them out here. + +And then you have +another material + +with an even higher gap, and +you can take those electrons out + +there. + +OK? + +And see because +otherwise, what happens? + +Otherwise, all the electrons +will-- in each case-- + +all the electrons +cascade down to here. + +They all wind up in that +conduction band or that LUMO + +state, if it's a molecule. + +No matter what, that's just +the dramatic and traumatic loss + +of solar materials. + +Right? + +Solar conversion, solar capture, +those electrons thermalize, + +because that process +of thermalization + +is so fast, that it's +very hard to beat. + +The way you beat it in +multijunction solar cells-- + +42% maybe is the record, +something like that. + +The way you beat it +is you literally just + +stick a level in there. + +So it's sort of a +cheat, but that's + +the only way to do it that we +know technologically today. + +If there were other ways +of extracting electrons out + +at their higher energies, +you could do wonders + +in solar capture and storage. + +In the molecule, the +electron thermalizes down, + +and the reaction goes in +that lowest excited state. + +So that gap has to be +bigger than delta H. OK? + +Does everybody see that? + +It's a very good question. + +So it's this +beautiful, constrained + +optimization problem. + +I love those, because +constrained optimization + +problems, I want this +to be really big, + +but I want this to stay not +less than an electron volt. + +But then if this +is really big, I + +can't absorb any of the light. + +Right? + +If I made delta H +huge, then I'd have + +to have a gap that +was like here, + +and I'd get almost +no solar efficiency. + +These are beautiful problems +for materials design + +and for computation, +because they're constrained, + +but they're not +that constrained. + +And using computers, +you can get your way out + +of that, those +constraints, sometimes. + +OK? + +And that's what's, I +think, really exciting. + +That's what your homework +is going to be about, and so + +let's calculate one of these. + +OK? + +Because that is the key +to the optical efficiency. + +Yeah? + +AUDIENCE: So is the gas thinner +than the just delta H or delta + +H plus the base? + +JEFFREY C. GROSSMAN: That's +a very good question, and-- + +AUDIENCE: He told me to ask. + +JEFFREY C. GROSSMAN: Yeah. + +Yeah. + +It's a very good question. + +So in general, +most of these kinds + +of photoactive molecules-- + +I've already talked to a +chemist, so I'm well armed. + +Most of these +photoactive molecules + +need the gap plus the +activation barrier, + +because in the excited state, +you'll get a similar barrier. + +It's not clear that's +always true though, + +and so that puts more +constraints on this. + +So it's even less of the +spectrum you can absorb, + +basically. + +Right? + +If you want to store +1 1/2 electron volts, + +and you need an electron volt +of an activation barrier, + +that's a 2 1/2 v-gap minimum. + +Which means you're closing +in on the UV, which + +means your optical efficiency +is probably at most 5%, 8%, 10%, + +at most. + +Right? + +That doesn't mean it's +a deal breaker at all. + +But there are also +cases where you + +do change the barrier +in the exciting state, + +and so we're looking into that. + +Now, I want another concept +here to come across which + +is really important. + +OK? + +And that is nothing more than +these levels smoothed out, + +and it's called the +density of states. + +OK? + +So if you do a calculation +of one of these molecules-- + +let me go back to here. + +Oh, yeah. + +You know we love this. + +Have you all rated this +say a 10 out of 10? + +Come on. + +You know it's a 10 experience. + +AUDIENCE: Someone gave it a 9.5? + +JEFFREY C. GROSSMAN: No. + +That's an average. + +OK. + +I want to start using-- + +we're going to use a different +tool for our next homework. + +We're going to use DFT +for solids, surfaces, + +and molecules. + +It's called SIESTA. + +It's another free software +that you can download. + +And it's solving +the same equations, + +but it uses different +approximations, different basis + +sets, and so forth. + +OK? + +But here, and you +see that basis sets + +are called different +things, but I've still + +tried to help by saying really +bad, mediocre, and OK, in terms + +of the quality. + +OK? + +Again, that's not the +focus in this class. + +Let's look at it, and we're +going to do a molecule here-- + +Uh-oh, there we go-- + +a molecule. + +And I'm going to upload one, +and you're going to get these. + +We'll give these +with the homeworks. + +We'll put them on Steller. + +So here's a trans state. + +Let's do the phenyl. + +Here's a trans state. + +We're going to upload +it and simulate. + +OK? + +And this is doing just +what the other code does. + +It's doing this self-consistent +cycle, where it's + +solving for the wave function. + +OK? + +And it's getting +the wave functions + +of all these levels for the +molecule I just entered. + +So it's going to give +me all these levels. + +That's what I want. + +Now, the way this plots +it though is in something + +called the density +of states, and all + +that is, as we'll see in a +minute, is you take these, + +and you turn it on the side. + +OK? + +So let's take a look. + +Is it done? + +Yes. + +There it is. + +Oh, this is a +beautiful solar fuel. + +It's actually got two +photo-switchable molecules + +hanging off the same +azobenzene ring. + +But anyway, and this-- + +where is the-- there we go. + +OK. + +So the key outputs, so +it tells you some things, + +and then you can go +to Density of States, + +and this is a very +important property. + +OK? + +This is the way that we like +to look at energy levels, + +especially in solids. + +So we're going to be +looking at DOS plots + +when we get to solids. + +OK? + +But in molecules, you +can look at the DOS plot + +as well, and +basically, what it is + +it's just these levels +turned on their side. + +So if there's a bunch of +levels near each other, + +you'll get a higher +peak in the DOS. + +You want to think about +it as averaging over + +the likelihood of finding +states at these energies. + +Has anybody seen a DOS plot? + +How many of you have seen a +DOS plot, a density of states? + +One or two? + +That's OK. + +They're energy levels +turned on their side. + +Right? + +Now, when we do solids, +it gets really fun. + +It gets really fun +when we do solids, + +because when we do +solids, like I said, + +these things go like this in +a space yet to be determined. + +And then you turn +those on their sides, + +and you still get the +same kind of DOS plot. + +But for molecules, this is +what it would look like. + +So there's a little +smoothing going on, + +but you're also +representing how many states + +you have near these energies. + +So that's why it's called +the density of states. + +Right? + +Gesundheit. + +Does everybody see that +this is that energy gap? + +This is it. + +That's the energy +gap, but there's + +more in the density of states. + +OK? + +So the energy gap, now I can-- + +watch this-- I can go +back, and I can magically + +put on some functional groups +and go to the amino benzene + +case, and I can do +that simulation. + +How many people really want +to hear about hydrogen storage + +or don't care? + +Be honest. + +Really want to hear +about hydrogen storage? + +In the back. + +Because I really want to make +this point, because also, + +this will be the basis +of your homework. + +But I can also take the +first 10 minutes of Thursday + +and talk about hydrogen storage. + +Hydrogen storage, nobody cares +about hydrogen storage anymore, + +do they? + +In the back, we have +one hydrogen storage. + +The hydrogen economy, +it was a big myth. + +Well, it's not a myth, +but it's a long way off. + +That we'd all be-- + +I'm not sure I would +use that-- that we'd all + +be driving hydrogen-powered +cars in this decade + +was a little bit of an +exaggeration, to say the least. + +So here's this guy. + +Now, what I did +is I decorated it. + +I did some, like I +thought-- oh, by the way, + +your computation is only +as good as what's up here. + +Right? + +So you need to think about +what you want to simulate, + +and here, we thought, +well, we had this one. + +OK? + +We had this one, and it's +not quite the same angle, + +but it's close. + +OK? + +So these guys are +going to switch, + +when the sun shines on +them, and store some energy + +and switch back. + +But I decided that I wanted +to try to do something + +about the strain in this state. + +Again, you're trying +to lower, remember-- + +you're trying to +lower these states, + +or change them, figure +out how to tune them. + +Right? + +So what I did is we +put a group in there. + +You can see, you put +a group in here which + +is going to cause some bonding, +when it's in the trans state. + +And you put another +group here which + +causes some bonding +between those OH + +groups and the nitrogen, +and that adds to the energy. + +It lowers the energy. + +Right? + +Now, as I said, we do that +with quantum mechanics, + +because it's actually not +that big of a problem, + +but that doesn't +tell me whether-- + +I may have made this a great +solar thermal fuel that + +can never absorb light. + +And so you got to go, and you've +got to look at these things, + +like the density of states. + +OK? + +And so here they are together, +and you can see that in-- + +so that's one. + +OK. + +So one is now bold, and you can +see that my modifications have + +done some interesting things. + +My chemical +modifications have really + +changed where those +energy levels are. + +Now, remember, they're +getting filled from here. + +Remember the filling. + +Right? + +You draw from the bottom, the +most energy favorable ones, + +all the way up, and +then you fill them up, + +and you stop filling here. + +Right? + +You stop filling here, +and that's your gap, + +and you can see that the gap +has changed considerably. + +So the gap has +changed considerably, + +and that changes +what kind of sunlight + +that molecule can absorb. + +Now, what's nice about +having the density of states + +is that, you see, +I'm getting-- in all + +of the energy levels-- is I'm +getting more than just the gap. + +Right? + +I'm getting other things. + +I'm getting shapes and peaks, +and here's a double peak. + +There's a single peak. + +Here's a little narrow peak, +but there's a really broad thing + +with like three +peaks and a shoulder. + +Right? + +That matters too. + +That matters a whole lot. + +OK? + +And the reason is that to a +very, very crude approximation, + +you can consider these peaks in +where the states are in energy + +as the places where +this molecule will + +be able to absorb light. + +OK? + +And so you can match this +up with the solar spectrum. + +Right? + +Because what you want +is for the molecules + +to be able to absorb light, +where there's a lot of light. + +And you don't really care +about them absorbing light. + +You don't necessarily need +them to have huge peaks, + +where there's no sunlight. + +Right? + +So now, you have an +interesting comparison + +of where these molecules +tend to absorb light + +and where the light is. + +OK? + +So let's go back +to this and make + +sure we know where I'm going. + +OK? + +So see, we talked about-- + +just another five +minutes or so I think + +to finish this discussion. + +We talked about how, +well, you don't want-- + +there are constraints on just +thinking about how big of a gap + +you want. + +Because it's a +constrained optimization + +problem with this thing and +this thing and this stuff. + +Right? + +We just talked about that. + +Now, I'm going to tell you +there's another problem, + +and that is that this +state is also photoactive. + +So this state can absorb +light which makes it go back. + +Well, that's a bummer. + +Right? + +That is a bummer. + +Now, what that +means is that, when + +I shine light on +this material, I + +will never get it +all to convert. + +I will never charge +all of the material + +and make it all go +from here to here, + +because there's constantly +a competition at play. + +Some of it will be going +this way, and some of it + +will be going that way. + +And what holds the key to +determining how much of which + +one is made? + +What holds the key? + +AUDIENCE: The ratio +of delta H plus EA. + +JEFFREY C. GROSSMAN: Well, +actually, but the delta H + +and EA are out of +the picture for now, + +because I'm only talking about +the absorption efficiency. + +What type of photons it +could absorb and what else? + +What type of photons +it can absorb and? + +Yeah? + +AUDIENCE: How many of +those types of photons-- + +JEFFREY C. GROSSMAN: Exactly. + +AUDIENCE: Your solar cell. + +JEFFREY C. GROSSMAN: +Exactly, and this. + +Right? + +So you're given this much +photons on planet Earth. + +You're give given the yellow, +if you go up a little bit. + +Right? + +We're not going to charge +our fuels in space. + +So this is what you +got, the red, and that's + +where the photons are in +energy, in wavelength energy, + +same thing. + +Now, I'm giving you the +fact that some molecules-- + +let's go back here. + +I can't just delete one, can I? + +I'm going to do one more +simulation while I talk. + +I wish it wouldn't show +my picture everywhere. + +I'm going to do the cis state. + +OK? + +You see, some molecules +in their cis state, + +they're still photoactive, +which means they go back here, + +when you shine light on them. + +What that means is that there's +going to be a stationary state. + +When I hold the +fuel out in the sun, + +the light is converting this +into this, as well as this + +into this with some +efficiency in both directions. + +And there will be +a stationary state + +that gives me a +percentage, or a yield, + +or as it's called +in the literature + +a quantum yield, of +charged material. + +How much is it? + +Well, in isolated azobenzene, +when you don't do anything + +to it, it's 25%. + +I can only charge +25% of this stuff + +in the photo-stationary state, +when I hold it out in the sun. + +And you can see why this +is such an important part + +of the problem, I +will remind you, + +a purely quantum mechanical +part of the problem. + +Because if I increase this, I +work so hard to increase this + +by a factor of three +or four, and then I + +can only charge a +fourth of it, that's + +a whole factor of four hit. + +If you can only charge a +fourth of it at a time, + +it's four times less useful. + +So it's effectively changing +this by four times back. + +Right? + +So this is critical. + +How much of this can you charge? + +Right? + +And that comes from +the quantum mechanics. + +Now, the way that you +get it is by looking at-- + +and I'll go through +the equations + +on the next line a minute. + +So here it is now in +the charged state. + +OK? + +So it's flipped. + +It's done its flip. + +You can see, it's rotated +those nitrogen bonds. + +It's a beautiful thing, kind of +an emotional moment in a way. + +And you go back to here, +and you look at your DOS, + +and now this is +kind of hard to see. + +Isn't it? + +One of these is the cis +state that I just mentioned, + +and it's different. + +I can't see, because +there's two trans + +states here and one cis state. + +I don't think there's any +way to just do simulations + +two and three, but I think you +know what I'm talking about. + +There's a density of +states for the trans. + +These levels here +turn on their side, + +and there's a density of +states for the cis state. + +And matching that +with the solar flux + +is what will give you the +photo-stationary state. + +It will give you the quantum +yield of the material. + +OK? + +That will be your +second homework. + +So this, let's see, this is +two ways that you could do it. + +OK? + +One way is you could just assume +that all of the photons higher + +in energy than the gap are +absorbed and lead to a switch. + +And if you do that, then the +fraction of the molecules + +in the cis state, if +you let them be x, + +you can show that +it's just going + +to be a simple integral +over the solar spectrum, + +that this I function, +up to the gap times x. + +That's how many are +in the cis state. + +Gesundheit. + +[NON-ENGLISH] Equals the number +that are in the trans state, + +1 minus x, times the integral +over the number of photons that + +convert the trans. + +OK? + +That's just +stationary-- that's just + +telling you that the change +in the concentration of cis + +is the same. + +It's like a reaction +kinetics equation, + +the rate of going from +one state to another times + +the number in that state equals +the same as the other way. + +That's all we've done here. + +But it gets more interesting if +you use the density of states, + +because now, you +have the absorption-- + +what I'm calling the absorption. + +Again, it's a +crude approximation + +for the absorption, but +let's just call it that-- + +of the cis state as a +function of the wavelength, + +convoluted with, or +times, the solar spectrum. + +Where you have states in +both is where it matters. + +Right? + +Where you have states in both +is where you hit the integral, + +and it's when those +are taken together + +that you can calculate +more accurately than just + +using the gap. + +You can calculate the +photo-stationary yield, + +and you get this all +from those energy levels, + +those beautiful energy +levels that we started + +this lecture talking about. + +OK? + +That yield is so important, +because it can kill your-- + +great idea for improving +delta H can get + +killed if the yield isn't good. + +OK? + +Maybe I'll spend 10 minutes +on hydrogen storage. + +Nobody raised their hands, +but we'll do another poll. + +And we're going to start +moving now-- you'll + +have a homework on this. + +It'll be lots of fun, and +then on Thursday, we're + +going to move into solids. \ No newline at end of file diff --git a/J5Mg_tqT18g.txt b/J5Mg_tqT18g.txt new file mode 100644 index 0000000000000000000000000000000000000000..44e66441bfedf96b5da99cff071eefcdb0b2ab41 --- /dev/null +++ b/J5Mg_tqT18g.txt @@ -0,0 +1,120 @@ +Using more complicated series/parallel networks +of switches, we can build devices that implement + +more complex logic functions. + +To design a more complex logic gate, first +figure the series and parallel connections + +of PFET switches that will connect the gate's +output to V_DD for the right combination of + +inputs. + +In this example, the output F will be 1 when +A is 0 OR when both B is 0 AND C is 0. + +The "OR" translates into a parallel connection, +and the "AND" translates into a series connection, + +giving the pullup circuit you see to the right. + +To build the complementary pulldown circuit, +systematically walk the hierarchy of pullup + +connections, replacing PFETs with NFETs, series +subcircuits with parallel subcircuits, and + +parallel subcircuits with series subcircuits. + +In the example shown, the pullup circuit had +a switch controlled by A in parallel with + +a series subcircuit consisting of switches +controlled by B and C. + +The complementary pulldown circuit uses NFETs, +with the switch controlled by A in series + +with a parallel subcircuit consisting of switches +controlled by B and C. + +Finally combine the pullup and pulldown circuits +to form a fully-complementary CMOS implementation. + +This probably went by a quickly, but with +practice you'll get comfortable with the CMOS + +design process. + +Mr. Blue is asking a good question: will this +recipe work for any and all logic functions? + +The answer is "no", let's see why. + +Using CMOS, a single gate (a circuit with +one pullup network and one pulldown network) + +can only implement the so-called inverting +functions where rising inputs lead to falling + +outputs and vice versa. + +To see why, consider what happens with one +of the gate's inputs goes from 0 to 1. + +Any NFET switches controlled by the rising +input will go from off to on. + +This may enable one or more paths between +the gate's output and GROUND. + +And PFET switches controlled by the rising +input will from on to off. + +This may disable one or more paths between +the gate's output and V_DD. + +So if the gate's output changes as the result +of the rising input, it must be because some + +pulldown path was enabled and some pullup +path was disabled. + +In other words, any change in the output voltage +due to a rising input must be a falling transition + +from 1 to 0. + +Similar reasoning tells us that falling inputs +must lead to rising outputs. + +In fact, for any non-constant CMOS gate, we +know that its output must be 1 when all inputs + +are 0 (since all the NFETs are off and all +the PFETs are on). + +And vice-versa: if all the inputs are 1, the +gate's output must be 0. + +This means that so-called positive logic can't +be implemented with a single CMOS gate. + +Look at this truth table for the AND function. + +It's value when both inputs are 0 or both +inputs are 1 is inconsistent with our deductions + +about the output of a CMOS gate for these +combinations of inputs. + +Furthermore, we can see that when A is 1 and +B rises from 0 to 1, the output rises instead + +of falls. + +Moral of the story: when you're a CMOS designer, +you'll get very good at implementing functionality + +with inverting logic! \ No newline at end of file diff --git a/J8L9kRGSvSY.txt b/J8L9kRGSvSY.txt new file mode 100644 index 0000000000000000000000000000000000000000..2a0d1a8dd0edee5c9aa00358057cb68a29a03411 --- /dev/null +++ b/J8L9kRGSvSY.txt @@ -0,0 +1,499 @@ +align:start position:0% + +we now want to introduce some examples + + align:start position:0% +we now want to introduce some examples + + + align:start position:0% +we now want to introduce some examples +of random variables and we will start + + align:start position:0% +of random variables and we will start + + + align:start position:0% +of random variables and we will start +with the simplest conceivable random + + align:start position:0% +with the simplest conceivable random + + + align:start position:0% +with the simplest conceivable random +variable a random variable that takes + + align:start position:0% +variable a random variable that takes + + + align:start position:0% +variable a random variable that takes +the values of zero or one with certain + + align:start position:0% +the values of zero or one with certain + + + align:start position:0% +the values of zero or one with certain +given probabilities such a random + + align:start position:0% +given probabilities such a random + + + align:start position:0% +given probabilities such a random +variable is called a Bernoulli random + + align:start position:0% +variable is called a Bernoulli random + + + align:start position:0% +variable is called a Bernoulli random +variable and the distribution of this + + align:start position:0% +variable and the distribution of this + + + align:start position:0% +variable and the distribution of this +random variable is determined by this + + align:start position:0% +random variable is determined by this + + + align:start position:0% +random variable is determined by this +parameter P which is a given number that + + align:start position:0% +parameter P which is a given number that + + + align:start position:0% +parameter P which is a given number that +lies in the interval between 0 & 1 + + align:start position:0% +lies in the interval between 0 & 1 + + + align:start position:0% +lies in the interval between 0 & 1 +using PMF notation we have the + + align:start position:0% +using PMF notation we have the + + + align:start position:0% +using PMF notation we have the +probability of 0 being equal to 1 minus + + align:start position:0% +probability of 0 being equal to 1 minus + + + align:start position:0% +probability of 0 being equal to 1 minus +P and the probability of taking the + + align:start position:0% +P and the probability of taking the + + + align:start position:0% +P and the probability of taking the +value of 1 equal to P if you wish to + + align:start position:0% +value of 1 equal to P if you wish to + + + align:start position:0% +value of 1 equal to P if you wish to +plot this particular PMF the plot is + + align:start position:0% +plot this particular PMF the plot is + + + align:start position:0% +plot this particular PMF the plot is +rather simple it consists of two bars + + align:start position:0% +rather simple it consists of two bars + + + align:start position:0% +rather simple it consists of two bars +one at 0 and 1 at 1 this one has a + + align:start position:0% +one at 0 and 1 at 1 this one has a + + + align:start position:0% +one at 0 and 1 at 1 this one has a +height of P and this has a height of 1 + + align:start position:0% +height of P and this has a height of 1 + + + align:start position:0% +height of P and this has a height of 1 +minus P Bernoulli random variables show + + align:start position:0% +minus P Bernoulli random variables show + + + align:start position:0% +minus P Bernoulli random variables show +up whenever you are trying to model a + + align:start position:0% +up whenever you are trying to model a + + + align:start position:0% +up whenever you are trying to model a +situation where you run a trial and that + + align:start position:0% +situation where you run a trial and that + + + align:start position:0% +situation where you run a trial and that +trial can result in two alternative + + align:start position:0% +trial can result in two alternative + + + align:start position:0% +trial can result in two alternative +outcomes either success or failure or + + align:start position:0% +outcomes either success or failure or + + + align:start position:0% +outcomes either success or failure or +heads versus tails and so on another + + align:start position:0% +heads versus tails and so on another + + + align:start position:0% +heads versus tails and so on another +situation where Bernoulli random + + align:start position:0% +situation where Bernoulli random + + + align:start position:0% +situation where Bernoulli random +variables show up is when we're making a + + align:start position:0% +variables show up is when we're making a + + + align:start position:0% +variables show up is when we're making a +connection between events and random + + align:start position:0% +connection between events and random + + + align:start position:0% +connection between events and random +variables here's how this connection is + + align:start position:0% +variables here's how this connection is + + + align:start position:0% +variables here's how this connection is +made we have our sample space Omega and + + align:start position:0% +made we have our sample space Omega and + + + align:start position:0% +made we have our sample space Omega and +within that sample space we have a + + align:start position:0% +within that sample space we have a + + + align:start position:0% +within that sample space we have a +certain event a and outside the event a + + align:start position:0% +certain event a and outside the event a + + + align:start position:0% +certain event a and outside the event a +of course we have the complement of a + + align:start position:0% +of course we have the complement of a + + + align:start position:0% +of course we have the complement of a +our random variable is defined so that + + align:start position:0% +our random variable is defined so that + + + align:start position:0% +our random variable is defined so that +it takes a value of 1 whenever the + + align:start position:0% +it takes a value of 1 whenever the + + + align:start position:0% +it takes a value of 1 whenever the +outcome of the experiment lies in a and + + align:start position:0% +outcome of the experiment lies in a and + + + align:start position:0% +outcome of the experiment lies in a and +it takes a value of 0 + + align:start position:0% +it takes a value of 0 + + + align:start position:0% +it takes a value of 0 +whenever the outcome of the experiment + + align:start position:0% +whenever the outcome of the experiment + + + align:start position:0% +whenever the outcome of the experiment +lies outside the event a so that it lies + + align:start position:0% +lies outside the event a so that it lies + + + align:start position:0% +lies outside the event a so that it lies +in the complement this random variable + + align:start position:0% +in the complement this random variable + + + align:start position:0% +in the complement this random variable +is called the indicator random variable + + align:start position:0% +is called the indicator random variable + + + align:start position:0% +is called the indicator random variable +of the event a it is equal to 1 if and + + align:start position:0% +of the event a it is equal to 1 if and + + + align:start position:0% +of the event a it is equal to 1 if and +only if event a occurs + + align:start position:0% +only if event a occurs + + + align:start position:0% +only if event a occurs +and the PMF of that random variable can + + align:start position:0% +and the PMF of that random variable can + + + align:start position:0% +and the PMF of that random variable can +be found as follows + + align:start position:0% +be found as follows + + + align:start position:0% +be found as follows +this is PMF notation this is the + + align:start position:0% +this is PMF notation this is the + + + align:start position:0% +this is PMF notation this is the +equivalent probabilistic notation this + + align:start position:0% +equivalent probabilistic notation this + + + align:start position:0% +equivalent probabilistic notation this +is the probability that a random + + align:start position:0% +is the probability that a random + + + align:start position:0% +is the probability that a random +variable takes a value of 1 now the + + align:start position:0% +variable takes a value of 1 now the + + + align:start position:0% +variable takes a value of 1 now the +random variable takes the value of 1 if + + align:start position:0% +random variable takes the value of 1 if + + + align:start position:0% +random variable takes the value of 1 if +and only if event a occurs and so what + + align:start position:0% +and only if event a occurs and so what + + + align:start position:0% +and only if event a occurs and so what +we have is that our random variable the + + align:start position:0% +we have is that our random variable the + + + align:start position:0% +we have is that our random variable the +indicator random variable is a Bernoulli + + align:start position:0% +indicator random variable is a Bernoulli + + + align:start position:0% +indicator random variable is a Bernoulli +random variable with a parameter P equal + + align:start position:0% +random variable with a parameter P equal + + + align:start position:0% +random variable with a parameter P equal +to the probability of the event of + + align:start position:0% +to the probability of the event of + + + align:start position:0% +to the probability of the event of +interest indicator random variables are + + align:start position:0% +interest indicator random variables are + + + align:start position:0% +interest indicator random variables are +very useful because they allow us to + + align:start position:0% +very useful because they allow us to + + + align:start position:0% +very useful because they allow us to +translate a manipulation of events to a + + align:start position:0% +translate a manipulation of events to a + + + align:start position:0% +translate a manipulation of events to a +manipulation of random variables and + + align:start position:0% +manipulation of random variables and + + + align:start position:0% +manipulation of random variables and +sometimes the algebra of working with + + align:start position:0% +sometimes the algebra of working with + + + align:start position:0% +sometimes the algebra of working with +random variables is easier than working + + align:start position:0% +random variables is easier than working + + + align:start position:0% +random variables is easier than working +with events as we will see in some later + + align:start position:0% +with events as we will see in some later + + + align:start position:0% +with events as we will see in some later +examples \ No newline at end of file diff --git a/JZkT3NU2mPM.txt b/JZkT3NU2mPM.txt new file mode 100644 index 0000000000000000000000000000000000000000..08babdc75b86af921acf4455a688324e67e77a4e --- /dev/null +++ b/JZkT3NU2mPM.txt @@ -0,0 +1,127 @@ +Let us now discuss an +interesting fact about + +independence that should enhance +our understanding. + +Suppose that events A and +B are independent. + +Intuitively, if I tell you that +A occurred, this does not + +change your beliefs as to the +likelihood that B will occur. + +But in that case, this should +not change your beliefs as to + +the likelihood that +B will not occur. + +So A should be independent +of B complement. + +In other words, the occurrence +of A tells you nothing about + +B, and therefore tells +you nothing about + +B complement either. + +This was an intuitive argument +that if A and B are + +independent, then A and +B complement are also + +independent. + +But let us now verify +this intuition + +through a formal proof. + +The formal proof goes +as follows. + +We have the two events, A and +B. And event A can be broken + +down into two pieces. + +One piece is the intersection +of A with B. So that's the + +first piece. + +And the second piece is the part +of A which is outside B. + +And that piece is A intersection +with the + +complement of B. So these are +the two pieces that together + +comprise event A. + +Now, these two pieces are +disjoint from each other. + +And therefore, by the additivity +axiom, the + +probability of A is equal +to the probability of A + +intersection B plus the +probability of A intersection + +with B complement. + +Using independence, the first +term becomes probability of A + +times probability of B. And we +leave the second term as is. + +Now let us move this term +to the other side. + +And we obtain that the +probability of A intersection + +with B complement is the +probability of A minus the + +probability of A times the +probability of B. We factor + +out the term probability of A, +and we are left with 1 minus + +probability of B. And then we +recognize that 1 minus the + +probability of B is the same +as the probability of B + +complement. + +So we proved that the +probability of A and B + +complement occurring together +is the product of their + +individual probabilities. + +And that's exactly the +definition of A being + +independent from B complement. + +And this concludes +the formal proof. \ No newline at end of file diff --git a/JyIsB5D3ZCg.txt b/JyIsB5D3ZCg.txt new file mode 100644 index 0000000000000000000000000000000000000000..095c2c0d896f0f3b59d00fcdba0ce2463b3f88f2 --- /dev/null +++ b/JyIsB5D3ZCg.txt @@ -0,0 +1,1719 @@ +PROFESSOR: We had begun to +discuss, really what is, + +although you would not gather +it from last time, a fairly + +straightforward matter. + +Set up our usual Cartesian +coordinate system. + +And then look at the surface of +the solid, and applied to + +this solid a force per unit +area, which we'll represent by + +a vector k. + +And then put on some +labels here. + +Let this be O. Let this be A, +let this be B, and this be + +point C. Then we +proceeded to-- + +I will say, attempt to-- + +set up a balance of forces +between the external force per + +unit area and the internal +forces per unit area, which + +have to push back on the +external force if the solid is + +to remain motionless. + +The thing that I did not carry +through is that there are two + +directions involved. + +One is the direction to the +normal, to the particular + +surface that we're looking at. + +We'll call that N. And there is +the direction that k, the + +vector k, makes with respect to +the three reference x axes, + +x1, x2, x3. + +Let's take k and immediately +split it up into the three + +components, k1, k2, k3, because +throughout, we're + +going to be dealing with the +balance of those three forces + +per unit area in the directions +of x1, x2, and x3. + +We want to take this surface +area and resolve it into three + +separate areas that are +normal to x1, x2, x3. + +And what I did at the end of +last hour was to look at k and + +try to express these internal +areas in terms of the + +direction cosines of k. + +Forget that. + +We've split up k into its three +components, and I didn't + +draw in the direction +of the normal to the + +surface N last time. + +So I kept saying, direction +cosines of k, and people in + +the audience said, +no, no, no, no. + +And I said, yeah, because you +see, that's the ratio + +of these two areas. + +And everybody said, no, that's +wrong, and I said, ha. + +And that's where we ended +my most inglorious hour. + +And they've got this +all down on tape. + +My reputation's going +to be ruined. + +So, anyway, let's now +do it properly. + +And what I will say is that in +the x1 direction, we have to + +have internal forces that push +back, and we have to balance + +those forces in all +three directions. + +So I'll say is that in the x1 +direction, and this as you saw + +last time, gets very cumbersome +because we have to + +deal with all these clumsy +areas, that the force per unit + +area on ABC has to be balanced +for each of the three + +components of k by internal +forces acting + +along x1, x2, and x3. + +So we can say is that the first +in the x1 direction, the + +component of k that acts on +the surface ABC in the x1 + +direction has to be balanced +by internal forces. + +And let's look first at +the x1 direction. + +So there are three internal +surfaces. + +They are the area BOC. + +That is this back surface here, +and the normal to that + +surface is x1. + +So let me define some forces +per unit area that are + +internal, and I'll use the +term sigma for that. + +And I will use a first subscript +that gives the + +direction in which that force +per unit area acts, and I'll + +use a second subscript that +indicates the normal to the + +internal surface. + +So area BOC obviously, as we +observed a moment ago, has x1 + +as its normal. + +But there are three +internal surfaces. + +There will also be an internal +area, AOC, on which a force + +per unit area acts in +the x1 direction. + +So I'll call this one +by analogy to what I + +did a moment ago. + +I'll call this sigma 1, because +it acts in the x1 + +direction, and it acts on the +surface AOC, which has x2 as + +its normal. + +Then finally, there will be a +third force per unit area, + +sigma 1 3, acting in the x1 +direction, on a surface whose + +normal is perpendicular +to-- along x3. + +The surface is perpendicular +to x3. + +And that's area AOB. + +OK, so this is just a simple +balance of forces, external + +and internal balancing forces, +which act in the x1 direction. + +Then we'll write a similar thing +for the x2 direction. + +And we'll say that the x2 +component of force per unit + +area external to the volume +element acting on area ABC is + +going to be balanced by, again, +forces now acting in + +the x2 direction. + +So first, there will be a +component of 4 sigma 2 acting + +on the area that's normal to x1, +and that's the same area + +BOC, plus another force per +unit area acting in the x2 + +direction on the surface, whose +normal is a long x2. + +And that is, once +more, area AOC. + +And that would be a force per +unit area that I'll define, + +because it's my ball game +and I own the ball. + +So again, that would be sigma 2 +2, and then finally a sigma + +2 3 times the area whose +normal is x3. + +And I think I need not write +the third term that follows + +automatically from what +I've written so far. + +So now comes the geometry part, +where I'm going to get + +rid of these messy areas, and +I'm going to divide through by + +the external area on the +surface of the solid. + +I will then write accordingly +that k1 is equal to sigma 11 + +times the ratio of area BOC +divided by area ABC plus sigma + +12 times area AOC divided +by area AOB-- + +ABC, excuse me. + +Then finally sigma 1 3 times +area AOB divided by area ABC. + +So now I'll introduce a little +bit of geometry that caused + +such difficulties last time. + +If I have an area and project +it onto another area that + +makes an angle C with respect +to the first, this area A + +prime is equal to the area A +times the cosine of Phi and + +you could define that Phi in a +different way, namely take the + +normal to one of the two areas +and let M prime be the other + +normal, so C then is exactly +the same thing as the angle + +between the normals to +these two surfaces. + +So let's now look at what the +ratio of these two areas that + +we have is. + +What we're dealing with here is +an angle between the normal + +to the surface, not k, but the +normal to the surface, and + +either x1, x2, or x3. + +So the ratio of-- + +let's look at one of these +specific terms. + +The ratio of area BOC through +the ratio of the area ABC + +should be the cosine of the +angle between the normal to + +the surface and the normal +to area BOC. + +Well, the normal to area BOC is +x1, so that first ratio of + +areas is just going to be the +cosine of this angle. + +And that cosine is just the +direction cosine of N1 along + +the x1 of M along the +x1 direction. + +So this is just the direction +cosine between N, the normal + +to the surface, and x1. + +And let me say then that, by +definition, I'll let the + +direction to the normal be its +three direction cosines, L 1 + +plus L 2, plus J plus +L3 times k. + +These are the direction cosines +of the normal to the + +surface, and not k. + +So this then simply comes down +to sigma 11 times L1, the + +ratio of the area AOC to ABC +is going to be the angle + +between N and x2. + +And that's the angle whose +direction cosine is L2. + +And similarly, the ratio of +these two areas will be cosine + +minus 1 of L3. + +So this cumbersome construction +with ratios of + +areas just reduces to sigma 11 +L1 plus sigma 12 times L2 plus + +sigma 13 times L3. + +And the other two equations will +follow a similar form. + +K2 will be sigma 21 times L1 +plus sigma 22 times L2 plus + +sigma 23 times L3. + +Or in general, case of I will be +given by sigma I J times L + +to J. Easy. + +Nice and compact. + +Nice and simple. + +What can we say about this? + +K is a vector which has +components k1, k2, and k3. + +The direction cosines can be, +as we said a moment ago, can + +be regarded as the components +of a unit vector pointing + +along the normal +to the surface. + +So k is a vector. + +These three direction cosines +are the direction cosine to a + +unit vector normal +to the surface. + +If we were to be so foolish to +try to change the coordinate + +system., having just gotten it +right for the first time in + +one coordinate system, we know +exactly how the two vectors + +will change because +we have a law for + +transformation of a vector. + +If we were to change the +coordinate system, the + +components of k would wink on +end of and take new values and + +we know exactly how the +components of a vector will + +change as we change +coordinate system. + +OK, if this transforms like a +vector and this transforms + +like the vector, then the 3 by +3 array of coefficients which + +relate those to quantities +must be a tensor. + +So we've proven rigorously that +sigma IJ is a tensor, in + +particular, it's a second +rank tensor. + +And were we to change coordinate +system, we know + +from what we've done in the +past, exactly how the numbers + +that make up this 3 by 3 +array will transform. + +These quantities, sigma IJ, +are something that you've + +probably encountered, introduced +to be sure, + +probably in a little +different way. + +These are the elements of +stress, and sigma IJ is the + +stress tensor. + +We can immediately, on physical +grounds, established + +that sigma IJ must be +a symmetric tensor. + +So let's set up two axes, x1, +and x2, and x3 obviously is + +normal to the board. + +And let us look at some +off-diagonal terms like sigma + +12 and sigma 21. + +Sigma 1 2 would be a force +acting on the x1 direction on + +a surface whose normal is x2. + +So this is going to be a sheer +stress and that, to prevent + +any translation of the volume +element, must be balanced by a + +sigma 12 on the other +face that acts in + +the opposite direction. + +We're going to need a convention +for defining sign, + +S-I-G-N, of what constitutes a +positive element of stress and + +a negative element of stress. + +And I'll define a plus sigma +IJ as a force per unit area + +acting in the plus xi direction +on a surface whose + +normal is plus xj. + +So if this is a force per unit +area acting on this surface, + +and it acts in the direction +of x1 on a surface whose + +normal is x2, what I've shown +here is a positive sigma 12. + +A sheer force going in the +opposite direction would be a + +negative sigma 12. + +A positive sigma 11 would be +a stress that's tensile, a + +negative sigma 11 would be a +stress that's compressive. + +So here's a sigma 12, a sigma +12 on the opposite face. + +If we went away and turned our +back, this volume element + +would start accelerating, +getting an angular + +acceleration, would start +furiously spinning about the + +x3 axis like a top. + +So something, if this volume +element is, by definition, an + +equilibrium, something has +to balance this couple. + +And if it's to stay put, we must +have a sheer force like + +this and a sheer force +like this. + +And that's the only thing +available from the nine + +elements of stress that will +give a net torque on the + +volume element. + +So what are these? + +This is a stress that +acts on the surface + +whose normal is x2-- + +whose normal as x1 in +the x2 direction. + +So this is sigma 21. + +It acts in x2 direction, +and its normal is x1. + +An x, and then [? plus ?] + +x2 direction on [? I ?] + +surface, which has a normal +that is along x1. + +So the only way we can avoid an +angular acceleration is to + +say that sigma 12 has to be +identical to sigma 21 if + +there's no rotation about x3. + +And looking at the couple's that +act about x2, and x3, we + +could say in general that sigma +IJ is going to have to + +be equal to sigma JI for a +volume element in equilibrium. + +So stress then is equilibrium +is in place, has to be a + +symmetric tensor. + +It is, however, a plain old +second-rank tensor like all of + +the other second-rank tensors +that we've spent the last + +month talking about. + +And I think I tried to swindle +you on this one before. + +If this is a second-rank tensor, +the stress tensor must + +be symmetric and diagonal +for a cubic crystal. + +In other words, the stress +tensor sigma IJ must have the + +form sigma 0 0, 0 sigma 0, 0 0 +sigma because we've shown that + +that is what is required of a +tensor if the crystal has + +cubic symmetry. + +So surprisingly, you cannot +subject a single crystal with + +cubic material to +sheer stress. + +Any quarrel with that? + +Should we move on? + +We better not, but somebody +better raise an objection. + +That's not true, obviously. + +I can take a cubic crystal and +shear the stuffings out of it. + +So what's going on here? + +AUDIENCE: The tensor property +that you are applying to + +[INAUDIBLE] + +property of the [? crystal. ?] + +But if it is an outside force, +it doesn't [INAUDIBLE]. + +PROFESSOR: This is one +of your good days. + +AUDIENCE: [INAUDIBLE] + +society [INAUDIBLE]. + +PROFESSOR: That makes it an +especially good day because + +you're paying attention to +what I said for a change. + +The distinction here, and I did +make it last time-- it was + +one of the things that +I did correctly-- + +that there are really two kinds +of things that have to + +be described by second-rank +tensors. + +There are the things that we +have been spending most of our + +time on, and these are property +tensors and-- + +I mentioned last time, too, so +I know I said this before-- + +Nye calls them field tensors. + +I'm sorry. + +Nye calls them property +tensors, also. + +And these are something that +depends on the structure and + +bonding and other + +characteristics of the material. + +The stress is something that we +we're taking and imposing + +on an innocent, unsuspecting +crystal, and that is + +something we do. + +And we can, by design, twist it, +shear it, stretch it, as + +hard as we like, provided +we don't break it. + +And so this is something that +is externally imposed on the + +crystal, and this is something +that's called a field tensor. + +We mentioned last time +the meaning of field. + +The field is a volume of space +and a field tensor is a space + +in which a value of the tensor +is defined as every point, x1, + +x2, x3, in the space. + +Just as an electric field is a +vector field and you define + +the electric field we as a +function of every point x1, + +x2, x3, in the space. + +So there's no reason whatsoever +that there need be + +restrictions on the tensor +that we apply. + +And when we can cross out that +interesting, but incorrect, + +supposition. + +But they can be a lot of +different forms, special + +forms, of stress tensors which +have special forms simply + +because of the nature +of what we do. + +And these have restrictions and +equalities that have no + +counterpart in property +tensors. + +For example, we can have the +cancer sigma 00000000, which + +is something we could never +have identically so for a + +property tensor. + +And what does this represent? + +This is a tensor for which sigma +IJ is 0, unless I equals + +J equals 1. + +So this is the only thing that's +going on, is a force + +per unit area along +the x1 direction. + +So this is a uniaxial stress. + +And that is a stress field +which we could apply on a + +piece of material very easily. + +Just screw a hook into the +material and hang a weight on + +the hook and you've got +uniaxial stress. + +We can also have something +that's a little harder to + +visualize, a biaxial stress. + +And this would be a stress that +had elements sigma 11, + +register 0-- + +at least when we refer +to principal axes-- + +0 sigma 2 2 0 0 0 0. + +When it's in diagonal +form, two of the + +diagonal terms are 0. + +That doesn't seem to make sense +because, if this is a + +force per unit area along x1, +and this is a force per unit + +area along x2, can't we add up +those vectors and say that + +that's a uniaxial stress? + +Depends on your coordinate +system. + +If you want an example of a +biaxial stress, imagine some + +firemen underneath a burning +building, and they're holding + +out a blanket for somebody +to jump into. + +You have one pair of firemen +pulling in this direction to + +keep the blanket taut, and +another pair of firemen are + +not quite so vigorous, and +they're pulling in an + +orthogonal direction. + +And those two forces, sigma 11 +and sigma 22, create a biaxial + +stress event material. + +You could change the form of +the tensor by rotating the + +coordinate system, but +this is one example + +of a biaxial stress. + +The final general form, a +triaxial stress, obviously by + +extension, is going to be where +of all three diagonals, + +sigma 11, sigma 22, and sigma +33, are non-zero when you put + +the tensor in diagonal form. + +This would be a general +triaxial stress. + +And an example of that would +be when the jumping person + +lands on the blanket, there's +going to be a force that his + +or her mass exerts on the +blanket, and that would be a + +third sigma 3 3. + +So that would be a +triaxial stress. + +Let me give you a couple of +special cases of specialized + +stress tensors. + +And suppose I had a triaxial +stress, but all the diagonal + +terms were equal. + +That's something that I tried +a moment ago to hoodwink you + +into believing was required by +a cubic crystal, but suppose + +that was the form of +the stress tensor. + +What would that represent? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: That is something +that's going to be-- + +yeah, very good. + +That's not a pressure. + +It's a dilation. + +But if I make it into a more +familiar form, put it here, + +minus P, minus P, minus P. It's +a force prevented area. + +That's where the stress is. + +If it's a hydrostatic pressure, +it's squeezing the + +volume element so it has to be, +by our definition, acting + +in a negative x1 direction +on a surface whose + +normal is plus x1. + +So minus P, minus P, +minus P, represents + +a hydrostatic pressure. + +And now, unless you've seen it +before, or you're reading the + +notes instead of listening to +me, let me give you a really + +strange-looking one. + +What is this stress tensor? + +Where sigma 22 is opposite +in sign but equal in + +magnitude to sigma 11. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah. + +Good. + +The way to see that + +geometrically is the following. + +What we're doing is, we're +pushing with a force per unit + +area in this direction. + +That would be sigma 11, and +then we squeeze in the + +orthogonal direction. + +And that is a sigma 22, +which is negative. + +If we rotate the solid by 90 +degrees, then we've got this, + +plus this, acting on this face, +same forces per unit + +area as we have here. + +And that is a net force per +unit area like this. + +On the opposite surface, we've +got this force per unit area + +and this force per unit +area, component + +going in this direction. + +And that is going to be a force +that goes like this. + +That's going to be a force per +unit area like this, and + +similarly, this combined with +this is going to be a force + +acting in the reverse +direction. + +That would be, again, this with +this, and this would be + +this with that. + +So clearly, that is a body +that's being subjected to pure + +sheer, and if we rotated the +axes x1 and x2 by 45 degrees + +to an x1 prime and x2 prime +like this, and then + +transformed the tensor, it +would take the form 0 + +sigma sigma 0 0. + +And then, what do we want now? + +This would be the only +thing we get. + +Except I should be careful to +put a sigma prime on this + +because, when we change axes, +these sigmas will not be of + +the same magnitude as +the original ones. + +There's going to be a square +root of 2 coming from cosine + +of 45 degrees in there. + +But, anyway, just rotating the +axes 45 degrees of as I've + +indicated schematically here +with vector sums is going to + +give me two off diagonal terms +equal in magnitude that would + +correspond to sigma +12 and sigma 21. + +So those are some special forms +of a stress tensor when + +you place it in a diagonalized +form. + +But let's conclude this part of +our discussion by observing + +that everything that we've said +about second-rank tensors + +holds for the stress tensor. + +For example, you can always +select new axes that put the + +tensor in diagonal form. + +So that's one general +property. + +You can define a stress quadric, +and we'll do that + +with the equation sigma +ij xi xj equals 1. + +Why not? + +It's a second-ranked tensor. + +We can take the elements and +construct a surface from it. + +This quadric will have the +properties of any other + +quadric for a second-rank +tensor. + +In particular, if we construct +the quadric, it's now for sure + +going to be able to be either +an ellipsoid, an hyperboloid + +of one or two sheets, or in this +case, even an imaginary + +ellipsoid for a stress that's +everywhere compressive. + +The quadric could have +its diagonal + +elements all negative. + +The radius of the stress +quadric in a particular + +direction is going to be the 1 +over the square root of the + +property in that direction. + +What does that mean, stress +in a given direction? + +Well, let's again remember +how we have + +defined the stress tensor. + +A force per unit area has three +components, k1, k2, k3, + +and they're equal to +sigma ij times lj. + +So the value of the property in +this direction is going to + +be the value of the property +in the direction defined by + +[? elsa ?] j and the values of +[? elsa ?] j are components of + +the unit vector that point +in that direction. + +So if this is the direction of +k, [? off ?] like this, the + +value of this quadric in this +direction is going to be the + +value of the part of k that's +parallel to the radius vector + +over the magnitude of +the radius vector. + +But the [? radius ?] vector is +a unit vector, so it's simply + +going to be equal +to k parallel. + +And if k parallel is the part +of the vector that is along + +the surface normal, that is +going to be the component of k + +which is purely tensile. + +This is a force per unit area, +has parts that are, components + +that are normal to the +surface normal. + +Those are shear components. + +The component that's directly +along the normal to the + +surface is going to be a purely +tensile component. + +And, therefore, the radius +of the quadric in a given + +direction gives us the tensile +component of the force density + +vector k that is transmitted +across the face-- + +so let's not say face, +but interface-- + +whose normal is in the +direction of R. + +So this is the radius vector. + +That's the direction of the +normal to a surface and 1 over + +the radius of-- + +The radius of the quadric in +that direction is going to be + +1 over the square root of the +tensile component of stress + +that's transmitted across an +interface in this direction. + +How are we doing on time? + +Any questions at this point? + +AUDIENCE: Can you explain how +you know that's [INAUDIBLE]? + +PROFESSOR: Remember what our +radius normal property said. + +If we have a tensor like good +conductivity, where a current + +density is related to an +applied electric field, + +[? essa ?] j and we've-- + +unfortunately, that's +segment 2. + +This is the conductivity +tensor. + +What we said is that, if we +take the components of the + +tensor, sigma ij, and construct +the surface sigma ij + +xij equals unity, that will be +some sort of quadratic form + +that has the property that the +radius in any given direction + +is 1 over the square root of +the value of the property, + +sigma conductivity +in this case. + +Bad case. + +I shouldn't have picked +things where the + +sigma is also involved. + +And the value of the property +in the given direction is + +going to be the parallel +component of what happens over + +the magnitude of what you do. + +So in the case of electrical +conductivity, if we apply a + +field in this direction, the +value of the property is going + +to be that part of the current +flow, which is parallel to the + +electric field, divided +by the magnitude of + +the electric field. + +So that is a relation that you +know by heart and have come to + +not only know, but to love. + +So what are we saying here? + +For the stress tensor, we can +take the elements of the + +stress tensor and construct +a quadric. + +And the thing that's related +here is a force per unit area + +that we're applying to the +surface of the crystal, and + +that's transmitted through the +volume of the crystal by the + +relation that we have defined +as the stress tensor. + +So, unfortunately, +again, sigma Ij. + +And now what is involved are the +direction cosines of the + +normal to the surface. + +So what is the applied vector? + +The applied vector is a unit +vector, and this is the normal + +to the surface. + +And the surface in question +would be a surface like this. + +The thing that results is +a force per unit area k. + +So what we're doing is taking +k, the value of + +sigma, in that direction. + +A scalar quantity will be the +part of k that's parallel to + +the normal vector, +divided by the + +magnitude of the unit vector. + +And that's, a magnitude +of n is 1, so + +that's just k parallel. + +So this is the surface. + +This is its normal. + +And what the radius of the +quadric is going to give us is + +that part of the force density, +which is the force + +density vector resolved onto +the normal vector. + +And this is a tensile. + +This is the part of the +tensile stress that's + +transmitted. + +This is the total stress +that has a sheer part + +and a tensile part. + +The radius of the quadric is +going to give you the part + +that's transmitted across the +surface in this orientation. + +That is purely a +tensile force. + +That make sense? + +I should have done it +without sigmas being + +present in both tensors. + +So everything you want to know +about stress that's applied to + +a solid is contained in a +second-rank tensor that is + +symmetric and obeys all of the +characteristics that we + +derived earlier for property +tensors, even though this is a + +field tensor, and not +a property tensor. + +Let us then turn to the next +thing that I want to discuss, + +again something you've +heard before. + +But we'll do it within the +context of the tensor algebra + +that we've developed before. + +And this is the concept +of strength. + +And let me introduce +the subject by a + +one-dimensional analog. + +Suppose we have a very thin +elastic band fastened to some + +immovable surface, and this +will be the direction x. + +And then we pull on it. + +And here again, we have to be +complete and note that there + +are several different +kinds of behavior. + +One type of behavior is a case +where the elastic band + +stretches, and if there's some +point P on the initial state + +that point P will move to +a point P prime that is + +displaced from the original +location by a vector U. + +There's another point Q part +way along the elastic band. + +If the thing that we have +fastened to the elastic band + +slipped, and there's no +deformation at all, Q would be + +displaced by the same amount U +if there was just translation + +of the elastic because it wasn't +fastened down solidly. + +But if it's stretching here +between this point and this + +point, it's going to stretch +up here, too. + +And, in general, it will move +over to some point Q prime, + +and this displacement vector is +going to be the original U + +plus delta U. And what we care +about in defining strength is + +not the absolute coordinates, +but the interval + +between these points. + +This separation is U, and this +separation is U plus delta U. + +Now this is a common, but +not a necessarily + +unique, sort of behavior. + +This is something where the +displacement does not change + +along the length of +the elastic bands. + +This is something that's +called homogeneous + +deformation. + +And this is characterized by a +displacement view that varies + +linearly with position along +the elastic band. + +Does something like this. + +It's possible, in a [? grade ?] +of material, if + +you'd like a real example, +that U, as a function of + +distance along this +one-dimensional object, does + +something like this. + +Why not? + +That's what might happen +for example in-- + +that's almost an oxymoron, a +one-dimensional elastic band + +whose cross-sectional area +changes with distance in that + +one dimension. + +So this is homogeneous +deformation, as opposed to + +inhomogeneous deformation. + +There's another type of +behavior, and this is apparent + +if you place a thin piece of +metal or plastic, let's say, + +between the pair of grips in the +Instron machine, and after + +deformation, it does something +like this. + +There's an inhomogeneous +deformation, which is to + +referred to colloquially +as necking. + +A very good example of that is +what happens when you grab + +hold of some cheap plastic +shrink wrap that has been + +shrunk around a package that +has been mailed to you. + +And you want to get it +off, so you grab it. + +And it doesn't deform +elastically. + +What happens is that it necks +in places where there's a + +stress concentration. + +And you get something +exactly like this. + +And if we were to indicate that +sort of behavior, U as a + +function of position would be +one U, and then it would + +increase very rapidly. + +The [? UDX ?] + +would be very much larger than +the places which had uniform + +elastic deformation, so it would +be a nonlinear behavior + +of this sort. + +And that would be necking. + +If you've never noticed that +sort of behavior before, I + +give you an assignment tonight +of going home and getting a + +piece of Saran wrap from your +kitchen drawer and grabbing + +hold of it and pulling it. + +And it deforms non-uniformly in +a fashion that's indicative + +of necking. + +OK, it's just about five of. + +Why don't I stop there. + +And what I would like to do next +is to cast this relation, + +which is a one-dimensional +stream, into a + +three-dimensional situation. + +And we'll look at some of the +properties of the description + +of a body that's been deformed +in three dimensions. \ No newline at end of file diff --git a/KSD3avale8o.txt b/KSD3avale8o.txt new file mode 100644 index 0000000000000000000000000000000000000000..3fdfd9e7cb701725d8049204faddefd7c182bbbd --- /dev/null +++ b/KSD3avale8o.txt @@ -0,0 +1,8115 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu in the last class we were + + align:start position:0% +ocw.mit.edu in the last class we were + + + align:start position:0% +ocw.mit.edu in the last class we were +talking about the parasitic birds that + + align:start position:0% +talking about the parasitic birds that + + + align:start position:0% +talking about the parasitic birds that +lay their eggs in the nest of another + + align:start position:0% +lay their eggs in the nest of another + + + align:start position:0% +lay their eggs in the nest of another +bird and I asked you a question you know + + align:start position:0% +bird and I asked you a question you know + + + align:start position:0% +bird and I asked you a question you know +how why wouldn't these other + + align:start position:0% +how why wouldn't these other + + + align:start position:0% +how why wouldn't these other +birds evolve means of opposing that why + + align:start position:0% +birds evolve means of opposing that why + + + align:start position:0% +birds evolve means of opposing that why +don't they just learn to th recognize + + align:start position:0% +don't they just learn to th recognize + + + align:start position:0% +don't they just learn to th recognize +the eggs of the other bird you can see + + align:start position:0% +the eggs of the other bird you can see + + + align:start position:0% +the eggs of the other bird you can see +here that in many cases the can see that + + align:start position:0% +here that in many cases the can see that + + + align:start position:0% +here that in many cases the can see that +much larger egg + + align:start position:0% +much larger egg + + + align:start position:0% +much larger egg +there uh and yet they generally will + + align:start position:0% +there uh and yet they generally will + + + align:start position:0% +there uh and yet they generally will +raise it raise the check in fact it's + + align:start position:0% +raise it raise the check in fact it's + + + align:start position:0% +raise it raise the check in fact it's +it's often at the expense of their own + + align:start position:0% +it's often at the expense of their own + + + align:start position:0% +it's often at the expense of their own +chicks because the cuu is an aggressive + + align:start position:0% +chicks because the cuu is an aggressive + + + align:start position:0% +chicks because the cuu is an aggressive +chick uh often you know pushes the other + + align:start position:0% +chick uh often you know pushes the other + + + align:start position:0% +chick uh often you know pushes the other +the smaller chicks out of the nest + + align:start position:0% +the smaller chicks out of the nest + + + align:start position:0% +the smaller chicks out of the nest +sometimes the the Foster mother in this + + align:start position:0% +sometimes the the Foster mother in this + + + align:start position:0% +sometimes the the Foster mother in this +case uh is Raising only the + + align:start position:0% +case uh is Raising only the + + + align:start position:0% +case uh is Raising only the +kuu but at least her reproduction is + + align:start position:0% +kuu but at least her reproduction is + + + align:start position:0% +kuu but at least her reproduction is +considerably diminished by + + align:start position:0% +considerably diminished by + + + align:start position:0% +considerably diminished by +this by this problem + + align:start position:0% + + + + align:start position:0% + +and one of the reasons they do it has + + align:start position:0% +and one of the reasons they do it has + + + align:start position:0% +and one of the reasons they do it has +been investigated in a study of the the + + align:start position:0% +been investigated in a study of the the + + + align:start position:0% +been investigated in a study of the the +spotted Kaku and magpies um in + + align:start position:0% +spotted Kaku and magpies um in + + + align:start position:0% +spotted Kaku and magpies um in +Spain when + + align:start position:0% +Spain when + + + align:start position:0% +Spain when +the at a time when the + + align:start position:0% + + + + align:start position:0% + +uh the cus moved into an area the + + align:start position:0% +uh the cus moved into an area the + + + align:start position:0% +uh the cus moved into an area the +magpies were living or the mag Pi moved + + align:start position:0% +magpies were living or the mag Pi moved + + + align:start position:0% +magpies were living or the mag Pi moved +in I can't remember which I think the + + align:start position:0% +in I can't remember which I think the + + + align:start position:0% +in I can't remember which I think the +cus came in later okay and so they + + align:start position:0% +cus came in later okay and so they + + + align:start position:0% +cus came in later okay and so they +started laying their eggs in other + + align:start position:0% +started laying their eggs in other + + + align:start position:0% +started laying their eggs in other +bird's + + align:start position:0% +bird's + + + align:start position:0% +bird's +nest but then they found out that the + + align:start position:0% +nest but then they found out that the + + + align:start position:0% +nest but then they found out that the +birds often + + align:start position:0% +birds often + + + align:start position:0% +birds often +do destroy the kaku's + + align:start position:0% +do destroy the kaku's + + + align:start position:0% +do destroy the kaku's +egg but when they + + align:start position:0% +egg but when they + + + align:start position:0% +egg but when they +do there's sort of a MAG a Kaku Mafia + + align:start position:0% +do there's sort of a MAG a Kaku Mafia + + + align:start position:0% +do there's sort of a MAG a Kaku Mafia +that comes around and destroys their + + align:start position:0% +that comes around and destroys their + + + align:start position:0% +that comes around and destroys their +nest so then they don't reproduce at all + + align:start position:0% +nest so then they don't reproduce at all + + + align:start position:0% +nest so then they don't reproduce at all +and it's better to + + align:start position:0% +and it's better to + + + align:start position:0% +and it's better to +reproduce even a few than + + align:start position:0% +reproduce even a few than + + + align:start position:0% +reproduce even a few than +none so that was the mafia hypothesis + + align:start position:0% +none so that was the mafia hypothesis + + + align:start position:0% +none so that was the mafia hypothesis +and it was + + align:start position:0% +and it was + + + align:start position:0% +and it was +verified uh in + + align:start position:0% +verified uh in + + + align:start position:0% +verified uh in +Spain but there have been reports and I + + align:start position:0% +Spain but there have been reports and I + + + align:start position:0% +Spain but there have been reports and I +don't know of any uh really quanitative + + align:start position:0% +don't know of any uh really quanitative + + + align:start position:0% +don't know of any uh really quanitative +description of this but were cases + + align:start position:0% +description of this but were cases + + + align:start position:0% +description of this but were cases +when the song bird would uh build a a + + align:start position:0% +when the song bird would uh build a a + + + align:start position:0% +when the song bird would uh build a a +decoy Nest above his real nest and lay + + align:start position:0% +decoy Nest above his real nest and lay + + + align:start position:0% +decoy Nest above his real nest and lay +eggs in both and uh the caku generally + + align:start position:0% +eggs in both and uh the caku generally + + + align:start position:0% +eggs in both and uh the caku generally +will lay the egg in the the conspicuous + + align:start position:0% +will lay the egg in the the conspicuous + + + align:start position:0% +will lay the egg in the the conspicuous +Nest The Nest at the + + align:start position:0% +Nest The Nest at the + + + align:start position:0% +Nest The Nest at the +top and the nest below is more hidden U + + align:start position:0% +top and the nest below is more hidden U + + + align:start position:0% +top and the nest below is more hidden U +but I don't know just how often that + + align:start position:0% +but I don't know just how often that + + + align:start position:0% +but I don't know just how often that +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +happen but they have to do it in a way + + align:start position:0% +happen but they have to do it in a way + + + align:start position:0% +happen but they have to do it in a way +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +this uh group of tuus couldn't force + + align:start position:0% +this uh group of tuus couldn't force + + + align:start position:0% +this uh group of tuus couldn't force +them or couldn't destroy their n because + + align:start position:0% +them or couldn't destroy their n because + + + align:start position:0% +them or couldn't destroy their n because +they destroyed their + + align:start position:0% +they destroyed their + + + align:start position:0% +they destroyed their +egg but we saw this last time + + align:start position:0% +egg but we saw this last time + + + align:start position:0% +egg but we saw this last time +uh well so the Kaku is exploiting the + + align:start position:0% +uh well so the Kaku is exploiting the + + + align:start position:0% +uh well so the Kaku is exploiting the +innate releasing mechanism of the song + + align:start position:0% +innate releasing mechanism of the song + + + align:start position:0% +innate releasing mechanism of the song +birds that they use to raise their + + align:start position:0% +birds that they use to raise their + + + align:start position:0% +birds that they use to raise their +young it's because the they can't resist + + align:start position:0% +young it's because the they can't resist + + + align:start position:0% +young it's because the they can't resist +that big gape of the kuu + + align:start position:0% +that big gape of the kuu + + + align:start position:0% +that big gape of the kuu +chick it elicits feeding + + align:start position:0% +chick it elicits feeding + + + align:start position:0% +chick it elicits feeding +Behavior so they get + + align:start position:0% + + + + align:start position:0% + +fed but this kind of thing happens in + + align:start position:0% +fed but this kind of thing happens in + + + align:start position:0% +fed but this kind of thing happens in +humans too we discussed earlier how the + + align:start position:0% +humans too we discussed earlier how the + + + align:start position:0% +humans too we discussed earlier how the +food industry uh and restaurants add + + align:start position:0% +food industry uh and restaurants add + + + align:start position:0% +food industry uh and restaurants add +extra fat including saturated fat to + + align:start position:0% +extra fat including saturated fat to + + + align:start position:0% +extra fat including saturated fat to +Foods + + align:start position:0% +Foods + + + align:start position:0% +Foods +especially the fast food industry + + align:start position:0% +especially the fast food industry + + + align:start position:0% +especially the fast food industry +because people prefer the taste they + + align:start position:0% +because people prefer the taste they + + + align:start position:0% +because people prefer the taste they +want it to be fat think of all the + + align:start position:0% +want it to be fat think of all the + + + align:start position:0% +want it to be fat think of all the +people that that are eating the high fat + + align:start position:0% + + + + align:start position:0% + +uh potato uh what do they call + + align:start position:0% +uh potato uh what do they call + + + align:start position:0% +uh potato uh what do they call +them french fries the french fries I + + align:start position:0% +them french fries the french fries I + + + align:start position:0% +them french fries the french fries I +never eat them don't even remember their + + align:start position:0% +never eat them don't even remember their + + + align:start position:0% +never eat them don't even remember their +name all right when you're diabetic you + + align:start position:0% +name all right when you're diabetic you + + + align:start position:0% +name all right when you're diabetic you +know you really pay if you eat stuff + + align:start position:0% +know you really pay if you eat stuff + + + align:start position:0% +know you really pay if you eat stuff +Lake that the high fat because fat + + align:start position:0% +Lake that the high fat because fat + + + align:start position:0% +Lake that the high fat because fat +digests very slowly and it raises blood + + align:start position:0% +digests very slowly and it raises blood + + + align:start position:0% +digests very slowly and it raises blood +sugar for many hours afterwards has more + + align:start position:0% +sugar for many hours afterwards has more + + + align:start position:0% +sugar for many hours afterwards has more +than double the number of calories of + + align:start position:0% +than double the number of calories of + + + align:start position:0% +than double the number of calories of +protein and + + align:start position:0% +protein and + + + align:start position:0% +protein and +carbohydrate but what I mention here the + + align:start position:0% +carbohydrate but what I mention here the + + + align:start position:0% +carbohydrate but what I mention here the +doll indust stre uh this these are + + align:start position:0% +doll indust stre uh this these are + + + align:start position:0% +doll indust stre uh this these are +pictures from the iel iisi one of his + + align:start position:0% +pictures from the iel iisi one of his + + + align:start position:0% +pictures from the iel iisi one of his +papers uh and some of these properties + + align:start position:0% +papers uh and some of these properties + + + align:start position:0% +papers uh and some of these properties +of infants were pointed out by Lawrence + + align:start position:0% +of infants were pointed out by Lawrence + + + align:start position:0% +of infants were pointed out by Lawrence +and how you find it in many different + + align:start position:0% +and how you find it in many different + + + align:start position:0% +and how you find it in many different +species that babies have a relatively + + align:start position:0% +species that babies have a relatively + + + align:start position:0% +species that babies have a relatively +larger head relatively larger eyes they + + align:start position:0% +larger head relatively larger eyes they + + + align:start position:0% +larger head relatively larger eyes they +have short limbs + + align:start position:0% +have short limbs + + + align:start position:0% +have short limbs +uh short usually chubby Limbs and that + + align:start position:0% +uh short usually chubby Limbs and that + + + align:start position:0% +uh short usually chubby Limbs and that +that appearance of the baby elicits + + align:start position:0% +that appearance of the baby elicits + + + align:start position:0% +that appearance of the baby elicits +caregiving you know even + + align:start position:0% +caregiving you know even + + + align:start position:0% +caregiving you know even +uh a big aggressive male will respond to + + align:start position:0% +uh a big aggressive male will respond to + + + align:start position:0% +uh a big aggressive male will respond to +babies showing these properties + + align:start position:0% +babies showing these properties + + + align:start position:0% +babies showing these properties +especially if the baby's emitting the + + align:start position:0% +especially if the baby's emitting the + + + align:start position:0% +especially if the baby's emitting the +cute little sounds they make we call + + align:start position:0% +cute little sounds they make we call + + + align:start position:0% +cute little sounds they make we call +them cute because of the stimuli they + + align:start position:0% +them cute because of the stimuli they + + + align:start position:0% +them cute because of the stimuli they +have even + + align:start position:0% +have even + + + align:start position:0% +have even +men are affected by it and the doll + + align:start position:0% +men are affected by it and the doll + + + align:start position:0% +men are affected by it and the doll +industry uses that + + align:start position:0% +industry uses that + + + align:start position:0% +industry uses that +also uh in creating dolls the Cy doll is + + align:start position:0% +also uh in creating dolls the Cy doll is + + + align:start position:0% +also uh in creating dolls the Cy doll is +normally made with again relatively + + align:start position:0% +normally made with again relatively + + + align:start position:0% +normally made with again relatively +larger head and large eyes but if you + + align:start position:0% +larger head and large eyes but if you + + + align:start position:0% +larger head and large eyes but if you +overdo that what + + align:start position:0% +overdo that what + + + align:start position:0% +overdo that what +happens there's a line between what's + + align:start position:0% +happens there's a line between what's + + + align:start position:0% +happens there's a line between what's +cute and what's + + align:start position:0% +cute and what's + + + align:start position:0% +cute and what's +grotesque okay so obviously they they + + align:start position:0% +grotesque okay so obviously they they + + + align:start position:0% +grotesque okay so obviously they they +simply use uh human reactions to uh to + + align:start position:0% +simply use uh human reactions to uh to + + + align:start position:0% +simply use uh human reactions to uh to +shape the way they design those + + align:start position:0% + + + + align:start position:0% + +things okay now we we talk about key + + align:start position:0% +things okay now we we talk about key + + + align:start position:0% +things okay now we we talk about key +stimuli and we say that they can release + + align:start position:0% +stimuli and we say that they can release + + + align:start position:0% +stimuli and we say that they can release +fixed action + + align:start position:0% + + + + align:start position:0% + +patterns but we don't call all T + + align:start position:0% +patterns but we don't call all T + + + align:start position:0% +patterns but we don't call all T +stimuli that Engage The innate releasing + + align:start position:0% +stimuli that Engage The innate releasing + + + align:start position:0% +stimuli that Engage The innate releasing +mechanisms we don't call them releasers + + align:start position:0% +mechanisms we don't call them releasers + + + align:start position:0% +mechanisms we don't call them releasers +generally because that term is used + + align:start position:0% +generally because that term is used + + + align:start position:0% +generally because that term is used +somewhat + + align:start position:0% +somewhat + + + align:start position:0% +somewhat +differently a + + align:start position:0% +differently a + + + align:start position:0% +differently a +releaser + + align:start position:0% +releaser + + + align:start position:0% +releaser +is a stimulus property that has evolved + + align:start position:0% +is a stimulus property that has evolved + + + align:start position:0% +is a stimulus property that has evolved +for the purpose of communicating for the + + align:start position:0% +for the purpose of communicating for the + + + align:start position:0% +for the purpose of communicating for the +purpose of eliciting behavior from + + align:start position:0% +purpose of eliciting behavior from + + + align:start position:0% +purpose of eliciting behavior from +members of the same species + + align:start position:0% + + + + align:start position:0% + +so so this is the way it's defined a + + align:start position:0% +so so this is the way it's defined a + + + align:start position:0% +so so this is the way it's defined a +structure or a + + align:start position:0% +structure or a + + + align:start position:0% +structure or a +movement most often a combination that's + + align:start position:0% +movement most often a combination that's + + + align:start position:0% +movement most often a combination that's +evolved in the service of sending a + + align:start position:0% +evolved in the service of sending a + + + align:start position:0% +evolved in the service of sending a +signal so that is they emit key + + align:start position:0% +signal so that is they emit key + + + align:start position:0% +signal so that is they emit key +stimula so in nature whenever you see + + align:start position:0% +stimula so in nature whenever you see + + + align:start position:0% +stimula so in nature whenever you see +really showy color patterns or + + align:start position:0% +really showy color patterns or + + + align:start position:0% +really showy color patterns or +structures in any + + align:start position:0% +structures in any + + + align:start position:0% +structures in any +vertebrate and they don't have to be in + + align:start position:0% +vertebrate and they don't have to be in + + + align:start position:0% +vertebrate and they don't have to be in +vertebrates they can be in invertebrates + + align:start position:0% +vertebrates they can be in invertebrates + + + align:start position:0% +vertebrates they can be in invertebrates +as well and also any loud or regular + + align:start position:0% +as well and also any loud or regular + + + align:start position:0% +as well and also any loud or regular +sound utterance any regular complicated + + align:start position:0% +sound utterance any regular complicated + + + align:start position:0% +sound utterance any regular complicated +and rhythmically perform Movement Like + + align:start position:0% +and rhythmically perform Movement Like + + + align:start position:0% +and rhythmically perform Movement Like +evolves in the rituals of + + align:start position:0% +evolves in the rituals of + + + align:start position:0% +evolves in the rituals of +cording it functions as + + align:start position:0% +cording it functions as + + + align:start position:0% +cording it functions as +releaser + + align:start position:0% +releaser + + + align:start position:0% +releaser +and I'm showing you the cover of + + align:start position:0% +and I'm showing you the cover of + + + align:start position:0% +and I'm showing you the cover of +Smithsonian uh a Smithsonian publication + + align:start position:0% +Smithsonian uh a Smithsonian publication + + + align:start position:0% +Smithsonian uh a Smithsonian publication +there that shows the hamadryas ballooon + + align:start position:0% +there that shows the hamadryas ballooon + + + align:start position:0% +there that shows the hamadryas ballooon +face um but let's start with with humans + + align:start position:0% +face um but let's start with with humans + + + align:start position:0% +face um but let's start with with humans +describe two releasers in human one + + align:start position:0% +describe two releasers in human one + + + align:start position:0% +describe two releasers in human one +involving a motor pattern well that's + + align:start position:0% +involving a motor pattern well that's + + + align:start position:0% +involving a motor pattern well that's +easy + + align:start position:0% + + + + align:start position:0% + +smiling smiling is a movement but it's + + align:start position:0% +smiling smiling is a movement but it's + + + align:start position:0% +smiling smiling is a movement but it's +evolved because of the way it the + + align:start position:0% +evolved because of the way it the + + + align:start position:0% +evolved because of the way it the +stimuli it that cause a reaction in + + align:start position:0% +stimuli it that cause a reaction in + + + align:start position:0% +stimuli it that cause a reaction in +others + + align:start position:0% +others + + + align:start position:0% +others +okay almost all of us respond positively + + align:start position:0% +okay almost all of us respond positively + + + align:start position:0% +okay almost all of us respond positively +to + + align:start position:0% +to + + + align:start position:0% +to +smile okay and we smile whether we're + + align:start position:0% +smile okay and we smile whether we're + + + align:start position:0% +smile okay and we smile whether we're +aware of it or not in order to you know + + align:start position:0% +aware of it or not in order to you know + + + align:start position:0% +aware of it or not in order to you know +get those positive + + align:start position:0% +get those positive + + + align:start position:0% +get those positive +responses uh what other can can you + + align:start position:0% +responses uh what other can can you + + + align:start position:0% +responses uh what other can can you +think of anything else think of babies + + align:start position:0% +think of anything else think of babies + + + align:start position:0% +think of anything else think of babies +and their appearance they evolves not + + align:start position:0% +and their appearance they evolves not + + + align:start position:0% +and their appearance they evolves not +just the the larger head and the short + + align:start position:0% +just the the larger head and the short + + + align:start position:0% +just the the larger head and the short +limbs I mean there could be various + + align:start position:0% +limbs I mean there could be various + + + align:start position:0% +limbs I mean there could be various +reasons for that but they've evolved + + align:start position:0% +reasons for that but they've evolved + + + align:start position:0% +reasons for that but they've evolved +these chubby cheeks they actually have + + align:start position:0% +these chubby cheeks they actually have + + + align:start position:0% +these chubby cheeks they actually have +fat pads in their cheeks that disappear + + align:start position:0% +fat pads in their cheeks that disappear + + + align:start position:0% +fat pads in their cheeks that disappear +later + + align:start position:0% +later + + + align:start position:0% +later +on they've even Evol + + align:start position:0% +on they've even Evol + + + align:start position:0% +on they've even Evol +specifically to + + align:start position:0% +specifically to + + + align:start position:0% +specifically to +elicit a certain reaction and there's no + + align:start position:0% +elicit a certain reaction and there's no + + + align:start position:0% +elicit a certain reaction and there's no +doubt that human breasts have a similar + + align:start position:0% +doubt that human breasts have a similar + + + align:start position:0% +doubt that human breasts have a similar +function that is breasts don't have to + + align:start position:0% +function that is breasts don't have to + + + align:start position:0% +function that is breasts don't have to +be as large as they are they evolved in + + align:start position:0% +be as large as they are they evolved in + + + align:start position:0% +be as large as they are they evolved in +order to elicit + + align:start position:0% +order to elicit + + + align:start position:0% +order to elicit +response okay so these are what + + align:start position:0% +response okay so these are what + + + align:start position:0% +response okay so these are what +releasers + + align:start position:0% +releasers + + + align:start position:0% +releasers +are and there's of course many others + + align:start position:0% +are and there's of course many others + + + align:start position:0% +are and there's of course many others +you can think of very as emotionally + + align:start position:0% +you can think of very as emotionally + + + align:start position:0% +you can think of very as emotionally +expressions and things that also have + + align:start position:0% +expressions and things that also have + + + align:start position:0% +expressions and things that also have +evolved to as these signals social + + align:start position:0% +evolved to as these signals social + + + align:start position:0% +evolved to as these signals social +signals of various + + align:start position:0% +signals of various + + + align:start position:0% +signals of various +sorts now when we talk about mimicry + + align:start position:0% +sorts now when we talk about mimicry + + + align:start position:0% +sorts now when we talk about mimicry +we're usually talking about something + + align:start position:0% +we're usually talking about something + + + align:start position:0% +we're usually talking about something +that's evolved to affect the behavior of + + align:start position:0% +that's evolved to affect the behavior of + + + align:start position:0% +that's evolved to affect the behavior of +another species like the monarch + + align:start position:0% +another species like the monarch + + + align:start position:0% +another species like the monarch +butterfly has mimics because the Monarch + + align:start position:0% +butterfly has mimics because the Monarch + + + align:start position:0% +butterfly has mimics because the Monarch +is tastes terrible uh other you know + + align:start position:0% +is tastes terrible uh other you know + + + align:start position:0% +is tastes terrible uh other you know +Birds won't generally attack monarchs + + align:start position:0% +Birds won't generally attack monarchs + + + align:start position:0% +Birds won't generally attack monarchs +because they taste bad + + align:start position:0% +because they taste bad + + + align:start position:0% +because they taste bad +uh so they quickly learn you know it + + align:start position:0% +uh so they quickly learn you know it + + + align:start position:0% +uh so they quickly learn you know it +only takes one experience of a really + + align:start position:0% +only takes one experience of a really + + + align:start position:0% +only takes one experience of a really +horrible taste and animals won't do it + + align:start position:0% +horrible taste and animals won't do it + + + align:start position:0% +horrible taste and animals won't do it +again but so other butterflies and moths + + align:start position:0% +again but so other butterflies and moths + + + align:start position:0% +again but so other butterflies and moths +have evolved to mimic the bitter tasting + + align:start position:0% +have evolved to mimic the bitter tasting + + + align:start position:0% +have evolved to mimic the bitter tasting +ones and the same thing happens in some + + align:start position:0% +ones and the same thing happens in some + + + align:start position:0% +ones and the same thing happens in some +insects but in some cases a species + + align:start position:0% +insects but in some cases a species + + + align:start position:0% +insects but in some cases a species +evolves some way to mimic + + align:start position:0% + + + + align:start position:0% + +aminic that it affects its own species + + align:start position:0% +aminic that it affects its own species + + + align:start position:0% +aminic that it affects its own species +and I these are the two examples I like + + align:start position:0% +and I these are the two examples I like + + + align:start position:0% +and I these are the two examples I like +the mouth breeder fish let's look at + + align:start position:0% +the mouth breeder fish let's look at + + + align:start position:0% +the mouth breeder fish let's look at +that here the mouth breeder fish here's + + align:start position:0% +that here the mouth breeder fish here's + + + align:start position:0% +that here the mouth breeder fish here's +the male and if you look here at the uh + + align:start position:0% +the male and if you look here at the uh + + + align:start position:0% +the male and if you look here at the uh +the anal fin you see the little spots + + align:start position:0% +the anal fin you see the little spots + + + align:start position:0% +the anal fin you see the little spots +what are those orange + + align:start position:0% +what are those orange + + + align:start position:0% +what are those orange +spots well they look just like the eggs + + align:start position:0% +spots well they look just like the eggs + + + align:start position:0% +spots well they look just like the eggs +of the female mouth breeder well what is + + align:start position:0% +of the female mouth breeder well what is + + + align:start position:0% +of the female mouth breeder well what is +the mouth bre her do She lays her eggs + + align:start position:0% +the mouth bre her do She lays her eggs + + + align:start position:0% +the mouth bre her do She lays her eggs +and she takes them up in her mouth she + + align:start position:0% +and she takes them up in her mouth she + + + align:start position:0% +and she takes them up in her mouth she +breeds them in her + + align:start position:0% +breeds them in her + + + align:start position:0% +breeds them in her +mouth so she tries to get these + + align:start position:0% +mouth so she tries to get these + + + align:start position:0% +mouth so she tries to get these +too perfect for the + + align:start position:0% +too perfect for the + + + align:start position:0% +too perfect for the +male he comes after she comes after the + + align:start position:0% +male he comes after she comes after the + + + align:start position:0% +male he comes after she comes after the +male her her mouth is there trying to + + align:start position:0% +male her her mouth is there trying to + + + align:start position:0% +male her her mouth is there trying to +get at those eggs and what does he do he + + align:start position:0% +get at those eggs and what does he do he + + + align:start position:0% +get at those eggs and what does he do he +injects seen right into her + + align:start position:0% +injects seen right into her + + + align:start position:0% +injects seen right into her +mouth so he fertilizes her + + align:start position:0% +mouth so he fertilizes her + + + align:start position:0% +mouth so he fertilizes her +eggs so that's why the mouth breeder + + align:start position:0% +eggs so that's why the mouth breeder + + + align:start position:0% +eggs so that's why the mouth breeder +fish has evolved that way mouth breed or + + align:start position:0% +fish has evolved that way mouth breed or + + + align:start position:0% +fish has evolved that way mouth breed or +male now let's take + + align:start position:0% +male now let's take + + + align:start position:0% +male now let's take +baboons here's a here's a female Olive + + align:start position:0% +baboons here's a here's a female Olive + + + align:start position:0% +baboons here's a here's a female Olive +baboon and notice this pink patch on a + + align:start position:0% +baboon and notice this pink patch on a + + + align:start position:0% +baboon and notice this pink patch on a +rump used as a signal it's evolved to + + align:start position:0% +rump used as a signal it's evolved to + + + align:start position:0% +rump used as a signal it's evolved to +affect the male but then look males + + align:start position:0% +affect the male but then look males + + + align:start position:0% +affect the male but then look males +evolve a patch too and some of them like + + align:start position:0% +evolve a patch too and some of them like + + + align:start position:0% +evolve a patch too and some of them like +this I couldn't find a really pink one + + align:start position:0% +this I couldn't find a really pink one + + + align:start position:0% +this I couldn't find a really pink one +but this one's pink only at the edge but + + align:start position:0% +but this one's pink only at the edge but + + + align:start position:0% +but this one's pink only at the edge but +the hamadryas baboon it's even more + + align:start position:0% +the hamadryas baboon it's even more + + + align:start position:0% +the hamadryas baboon it's even more +obvious you know here's male hamadryas + + align:start position:0% +obvious you know here's male hamadryas + + + align:start position:0% +obvious you know here's male hamadryas +baboon and look at the pink rump on that + + align:start position:0% +baboon and look at the pink rump on that + + + align:start position:0% +baboon and look at the pink rump on that +animal and here are two females actually + + align:start position:0% +animal and here are two females actually + + + align:start position:0% +animal and here are two females actually +presenting to a male and you can see you + + align:start position:0% +presenting to a male and you can see you + + + align:start position:0% +presenting to a male and you can see you +know that's what's being imitated well + + align:start position:0% +know that's what's being imitated well + + + align:start position:0% +know that's what's being imitated well +why would they do that why would a male + + align:start position:0% +why would they do that why would a male + + + align:start position:0% +why would they do that why would a male +do + + align:start position:0% +do + + + align:start position:0% +do +that because if a female appears and + + align:start position:0% +that because if a female appears and + + + align:start position:0% +that because if a female appears and +presents to him it totally inhibits his + + align:start position:0% +presents to him it totally inhibits his + + + align:start position:0% +presents to him it totally inhibits his +aggressive + + align:start position:0% +aggressive + + + align:start position:0% +aggressive +response these are pretty aggressive + + align:start position:0% +response these are pretty aggressive + + + align:start position:0% +response these are pretty aggressive +animals okay and they need ways to turn + + align:start position:0% +animals okay and they need ways to turn + + + align:start position:0% +animals okay and they need ways to turn +off the aggression + + align:start position:0% +off the aggression + + + align:start position:0% +off the aggression +so the males have taken advantage of + + align:start position:0% +so the males have taken advantage of + + + align:start position:0% +so the males have taken advantage of +that they evolve a signal where they can + + align:start position:0% +that they evolve a signal where they can + + + align:start position:0% +that they evolve a signal where they can +turn off the aggression of a more + + align:start position:0% +turn off the aggression of a more + + + align:start position:0% +turn off the aggression of a more +dominant male and it protects + + align:start position:0% +dominant male and it protects + + + align:start position:0% +dominant male and it protects +them and many rodents many of these + + align:start position:0% +them and many rodents many of these + + + align:start position:0% +them and many rodents many of these +things are a little more subtle you know + + align:start position:0% +things are a little more subtle you know + + + align:start position:0% +things are a little more subtle you know +the uh a + + align:start position:0% +the uh a + + + align:start position:0% +the uh a +hamster a normal Syrian hamster is + + align:start position:0% +hamster a normal Syrian hamster is + + + align:start position:0% +hamster a normal Syrian hamster is +evolved + + align:start position:0% +evolved + + + align:start position:0% +evolved +uh these white patches on his vest okay + + align:start position:0% +uh these white patches on his vest okay + + + align:start position:0% +uh these white patches on his vest okay +if those are exposed it reduces the + + align:start position:0% +if those are exposed it reduces the + + + align:start position:0% +if those are exposed it reduces the +aggression of a male okay if he wants to + + align:start position:0% +aggression of a male okay if he wants to + + + align:start position:0% +aggression of a male okay if he wants to +attack he actually covers them with his + + align:start position:0% +attack he actually covers them with his + + + align:start position:0% +attack he actually covers them with his +feet okay because of the signal property + + align:start position:0% +feet okay because of the signal property + + + align:start position:0% +feet okay because of the signal property +that they have and similarly their white + + align:start position:0% +that they have and similarly their white + + + align:start position:0% +that they have and similarly their white +underbelly if they expose that because + + align:start position:0% +underbelly if they expose that because + + + align:start position:0% +underbelly if they expose that because +they're defeated in a fight it generally + + align:start position:0% +they're defeated in a fight it generally + + + align:start position:0% +they're defeated in a fight it generally +works pretty well to inhibit the attack + + align:start position:0% +works pretty well to inhibit the attack + + + align:start position:0% +works pretty well to inhibit the attack +so they won't get killed the only time + + align:start position:0% +so they won't get killed the only time + + + align:start position:0% +so they won't get killed the only time +I've had hamster males kill or or + + align:start position:0% +I've had hamster males kill or or + + + align:start position:0% +I've had hamster males kill or or +females they both are pretty aggressive + + align:start position:0% +females they both are pretty aggressive + + + align:start position:0% +females they both are pretty aggressive +kill another animal is is when it's an + + align:start position:0% +kill another animal is is when it's an + + + align:start position:0% +kill another animal is is when it's an +artificial situation in a cage where the + + align:start position:0% +artificial situation in a cage where the + + + align:start position:0% +artificial situation in a cage where the +animal gets caught and he can't expose + + align:start position:0% +animal gets caught and he can't expose + + + align:start position:0% +animal gets caught and he can't expose +the right + + align:start position:0% +the right + + + align:start position:0% +the right +stimuli like he's caught in the wire + + align:start position:0% +stimuli like he's caught in the wire + + + align:start position:0% +stimuli like he's caught in the wire +mesh or where they he's not they're in + + align:start position:0% +mesh or where they he's not they're in + + + align:start position:0% +mesh or where they he's not they're in +such Close Quarters he can't you know + + align:start position:0% +such Close Quarters he can't you know + + + align:start position:0% +such Close Quarters he can't you know +actually expose those signals all right + + align:start position:0% +actually expose those signals all right + + + align:start position:0% +actually expose those signals all right +just a couple of things we'll get on to + + align:start position:0% +just a couple of things we'll get on to + + + align:start position:0% +just a couple of things we'll get on to +the next class here the I want you to + + align:start position:0% +the next class here the I want you to + + + align:start position:0% +the next class here the I want you to +know what the dummy rule is it the rule + + align:start position:0% +know what the dummy rule is it the rule + + + align:start position:0% +know what the dummy rule is it the rule +is + + align:start position:0% +is + + + align:start position:0% +is +um that if you can make a simple + + align:start position:0% +um that if you can make a simple + + + align:start position:0% +um that if you can make a simple +model like those models of the + + align:start position:0% +model like those models of the + + + align:start position:0% +model like those models of the +stickleback female that elicits a fixed + + align:start position:0% +stickleback female that elicits a fixed + + + align:start position:0% +stickleback female that elicits a fixed +action pattern like the following + + align:start position:0% +action pattern like the following + + + align:start position:0% +action pattern like the following +response the male then we're dealing + + align:start position:0% +response the male then we're dealing + + + align:start position:0% +response the male then we're dealing +with a innate releasing mechanism + + align:start position:0% +with a innate releasing mechanism + + + align:start position:0% +with a innate releasing mechanism +something that + + align:start position:0% +something that + + + align:start position:0% +something that +has on the sensory side that's evolved + + align:start position:0% +has on the sensory side that's evolved + + + align:start position:0% +has on the sensory side that's evolved +to respond to those stimula but if you + + align:start position:0% +to respond to those stimula but if you + + + align:start position:0% +to respond to those stimula but if you +can't find a dummy stimulus that works + + align:start position:0% +can't find a dummy stimulus that works + + + align:start position:0% +can't find a dummy stimulus that works +it doesn't mean there's no releasing + + align:start position:0% +it doesn't mean there's no releasing + + + align:start position:0% +it doesn't mean there's no releasing +mechanism and the reason is this + + align:start position:0% +mechanism and the reason is this + + + align:start position:0% +mechanism and the reason is this +learning the usual role of + + align:start position:0% + + + + align:start position:0% + +learning in animals it does affect + + align:start position:0% +learning in animals it does affect + + + align:start position:0% +learning in animals it does affect +instinctive Behavior and the way it it + + align:start position:0% +instinctive Behavior and the way it it + + + align:start position:0% +instinctive Behavior and the way it it +usually doesn't affect the motor side + + align:start position:0% +usually doesn't affect the motor side + + + align:start position:0% +usually doesn't affect the motor side +very much different motor patterns can + + align:start position:0% +very much different motor patterns can + + + align:start position:0% +very much different motor patterns can +be linked in specific ways as we've + + align:start position:0% +be linked in specific ways as we've + + + align:start position:0% +be linked in specific ways as we've +talked about with the attack Behavior + + align:start position:0% +talked about with the attack Behavior + + + align:start position:0% +talked about with the attack Behavior +predatory attack and cats they do have + + align:start position:0% +predatory attack and cats they do have + + + align:start position:0% +predatory attack and cats they do have +to put the various individual fixed + + align:start position:0% +to put the various individual fixed + + + align:start position:0% +to put the various individual fixed +motor patterns together okay they learn + + align:start position:0% +motor patterns together okay they learn + + + align:start position:0% +motor patterns together okay they learn +that but the selectivity of the stimuli + + align:start position:0% +that but the selectivity of the stimuli + + + align:start position:0% +that but the selectivity of the stimuli +that elicit a fixed action pattern can + + align:start position:0% +that elicit a fixed action pattern can + + + align:start position:0% +that elicit a fixed action pattern can +be increased with + + align:start position:0% +be increased with + + + align:start position:0% +be increased with +learning okay + + align:start position:0% + + + + align:start position:0% + +so in imprinting you see that happening + + align:start position:0% +so in imprinting you see that happening + + + align:start position:0% +so in imprinting you see that happening +it it can change with the experience of + + align:start position:0% +it it can change with the experience of + + + align:start position:0% +it it can change with the experience of +the animal uh but even an animal that + + align:start position:0% +the animal uh but even an animal that + + + align:start position:0% +the animal uh but even an animal that +doesn't have to imprint he responds + + align:start position:0% +doesn't have to imprint he responds + + + align:start position:0% +doesn't have to imprint he responds +innately to something like the a novel + + align:start position:0% +innately to something like the a novel + + + align:start position:0% +innately to something like the a novel +box moved overhead above turkeys can + + align:start position:0% +box moved overhead above turkeys can + + + align:start position:0% +box moved overhead above turkeys can +elicit the anti-predator response of + + align:start position:0% +elicit the anti-predator response of + + + align:start position:0% +elicit the anti-predator response of +crouching and freezing but that can + + align:start position:0% +crouching and freezing but that can + + + align:start position:0% +crouching and freezing but that can +become more specific with + + align:start position:0% + + + + align:start position:0% + +experience okay now this will take us + + align:start position:0% +experience okay now this will take us + + + align:start position:0% +experience okay now this will take us +the rest of this hour and + + align:start position:0% +the rest of this hour and + + + align:start position:0% +the rest of this hour and +Monday + + align:start position:0% +Monday + + + align:start position:0% +Monday +uh I want to go through the theoretical + + align:start position:0% +uh I want to go through the theoretical + + + align:start position:0% +uh I want to go through the theoretical +models of fixed action pattern + + align:start position:0% +models of fixed action pattern + + + align:start position:0% +models of fixed action pattern +and the innate releasing + + align:start position:0% +and the innate releasing + + + align:start position:0% +and the innate releasing +mechanism of Lawrence and tenbergen + + align:start position:0% +mechanism of Lawrence and tenbergen + + + align:start position:0% +mechanism of Lawrence and tenbergen +which have been the major + + align:start position:0% +which have been the major + + + align:start position:0% +which have been the major +ones and you can easily see how their + + align:start position:0% +ones and you can easily see how their + + + align:start position:0% +ones and you can easily see how their +models can be uh put into computer + + align:start position:0% +models can be uh put into computer + + + align:start position:0% +models can be uh put into computer +models using uh information flow uh and + + align:start position:0% +models using uh information flow uh and + + + align:start position:0% +models using uh information flow uh and +that has been done uh fairly + + align:start position:0% +that has been done uh fairly + + + align:start position:0% +that has been done uh fairly +successfully the second thing is the + + align:start position:0% +successfully the second thing is the + + + align:start position:0% +successfully the second thing is the +hierarchy and chains of + + align:start position:0% +hierarchy and chains of + + + align:start position:0% +hierarchy and chains of +behavior the hierarchical organization + + align:start position:0% +behavior the hierarchical organization + + + align:start position:0% +behavior the hierarchical organization +of instinctive + + align:start position:0% +of instinctive + + + align:start position:0% +of instinctive +behavior and then + + align:start position:0% +behavior and then + + + align:start position:0% +behavior and then +uh special + + align:start position:0% +uh special + + + align:start position:0% +uh special +orientation by reflexes and an internal + + align:start position:0% +orientation by reflexes and an internal + + + align:start position:0% +orientation by reflexes and an internal +model we'll talk about that and then + + align:start position:0% +model we'll talk about that and then + + + align:start position:0% +model we'll talk about that and then +finally what happens when there are + + align:start position:0% +finally what happens when there are + + + align:start position:0% +finally what happens when there are +multiple motivations aroused + + align:start position:0% +multiple motivations aroused + + + align:start position:0% +multiple motivations aroused +simultaneously and that happens very + + align:start position:0% +simultaneously and that happens very + + + align:start position:0% +simultaneously and that happens very +commonly and + + align:start position:0% +commonly and + + + align:start position:0% +commonly and +sometimes two two motivations can be + + align:start position:0% +sometimes two two motivations can be + + + align:start position:0% +sometimes two two motivations can be +almost equally strong how does an animal + + align:start position:0% +almost equally strong how does an animal + + + align:start position:0% +almost equally strong how does an animal +handle that + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so Lawrence's model we call a it's + + align:start position:0% +so Lawrence's model we call a it's + + + align:start position:0% +so Lawrence's model we call a it's +sometimes been called a psycho hydraulic + + align:start position:0% +sometimes been called a psycho hydraulic + + + align:start position:0% +sometimes been called a psycho hydraulic +model it's really a sort of hydraulic + + align:start position:0% +model it's really a sort of hydraulic + + + align:start position:0% +model it's really a sort of hydraulic +mechanical model of U of the + + align:start position:0% +mechanical model of U of the + + + align:start position:0% +mechanical model of U of the +motivational State the action specific + + align:start position:0% +motivational State the action specific + + + align:start position:0% +motivational State the action specific +potential in his terms and he had two + + align:start position:0% +potential in his terms and he had two + + + align:start position:0% +potential in his terms and he had two +models he changed it after a while on + + align:start position:0% +models he changed it after a while on + + + align:start position:0% +models he changed it after a while on +the left there you see his old model uh + + align:start position:0% +the left there you see his old model uh + + + align:start position:0% +the left there you see his old model uh +the action specific potential was + + align:start position:0% +the action specific potential was + + + align:start position:0% +the action specific potential was +represent entered as a reservoir that + + align:start position:0% +represent entered as a reservoir that + + + align:start position:0% +represent entered as a reservoir that +they the + + align:start position:0% +they the + + + align:start position:0% +they the +endogenous uh stimulus that is an + + align:start position:0% +endogenous uh stimulus that is an + + + align:start position:0% +endogenous uh stimulus that is an +internal stimulus is always there and so + + align:start position:0% +internal stimulus is always there and so + + + align:start position:0% +internal stimulus is always there and so +it's gradually building up that level + + align:start position:0% +it's gradually building up that level + + + align:start position:0% +it's gradually building up that level +until uh it's released and he he has the + + align:start position:0% +until uh it's released and he he has the + + + align:start position:0% +until uh it's released and he he has the +release there by the + + align:start position:0% +release there by the + + + align:start position:0% +release there by the +uh he throws this mechanical thing where + + align:start position:0% +uh he throws this mechanical thing where + + + align:start position:0% +uh he throws this mechanical thing where +the the spring there represents some + + align:start position:0% +the the spring there represents some + + + align:start position:0% +the the spring there represents some +kind of inertia of the system but the + + align:start position:0% +kind of inertia of the system but the + + + align:start position:0% +kind of inertia of the system but the +releasing stimulus + + align:start position:0% +releasing stimulus + + + align:start position:0% +releasing stimulus +there caused the discharge of that + + align:start position:0% +there caused the discharge of that + + + align:start position:0% +there caused the discharge of that +fluid but then his observations on + + align:start position:0% +fluid but then his observations on + + + align:start position:0% +fluid but then his observations on +animals made him realize that it's not + + align:start position:0% +animals made him realize that it's not + + + align:start position:0% +animals made him realize that it's not +accurate enough so he revised + + align:start position:0% +accurate enough so he revised + + + align:start position:0% +accurate enough so he revised +it and he he realized that there's not + + align:start position:0% +it and he he realized that there's not + + + align:start position:0% +it and he he realized that there's not +only this + + align:start position:0% +only this + + + align:start position:0% +only this +endogenous + + align:start position:0% +endogenous + + + align:start position:0% +endogenous +input that's gradually building + + align:start position:0% +input that's gradually building + + + align:start position:0% +input that's gradually building +up like our tendency to blink our eyes + + align:start position:0% +up like our tendency to blink our eyes + + + align:start position:0% +up like our tendency to blink our eyes +gradually builds up until we blink and + + align:start position:0% +gradually builds up until we blink and + + + align:start position:0% +gradually builds up until we blink and +we do it spontaneously and we don't even + + align:start position:0% +we do it spontaneously and we don't even + + + align:start position:0% +we do it spontaneously and we don't even +think about it unless right now I'm + + align:start position:0% +think about it unless right now I'm + + + align:start position:0% +think about it unless right now I'm +conscious of it and I realized i' now + + align:start position:0% +conscious of it and I realized i' now + + + align:start position:0% +conscious of it and I realized i' now +blink twice since I started talking okay + + align:start position:0% +blink twice since I started talking okay + + + align:start position:0% +blink twice since I started talking okay +but he's got other stimuli there too and + + align:start position:0% +but he's got other stimuli there too and + + + align:start position:0% +but he's got other stimuli there too and +these are he calls Readiness increasing + + align:start position:0% +these are he calls Readiness increasing + + + align:start position:0% +these are he calls Readiness increasing +stimuli they are stimuli that don't act + + align:start position:0% +stimuli they are stimuli that don't act + + + align:start position:0% +stimuli they are stimuli that don't act +quite like the releasing they're not + + align:start position:0% +quite like the releasing they're not + + + align:start position:0% +quite like the releasing they're not +adequate to actually release the + + align:start position:0% +adequate to actually release the + + + align:start position:0% +adequate to actually release the +movement but they do increase the + + align:start position:0% +movement but they do increase the + + + align:start position:0% +movement but they do increase the +motivation + + align:start position:0% +motivation + + + align:start position:0% +motivation +okay and you can think how many of those + + align:start position:0% +okay and you can think how many of those + + + align:start position:0% +okay and you can think how many of those +could be + + align:start position:0% +could be + + + align:start position:0% +could be +learned but then the releasing + + align:start position:0% + + + + align:start position:0% + +stimulus the key stimuli that caused + + align:start position:0% +stimulus the key stimuli that caused + + + align:start position:0% +stimulus the key stimuli that caused +the the + + align:start position:0% +the the + + + align:start position:0% +the the +discharge of the fixed motor pattern is + + align:start position:0% +discharge of the fixed motor pattern is + + + align:start position:0% +discharge of the fixed motor pattern is +like just pouring more fluid rapidly + + align:start position:0% +like just pouring more fluid rapidly + + + align:start position:0% +like just pouring more fluid rapidly +into the cup so it he sees the releasing + + align:start position:0% +into the cup so it he sees the releasing + + + align:start position:0% +into the cup so it he sees the releasing +stimula is just something that raises + + align:start position:0% +stimula is just something that raises + + + align:start position:0% +stimula is just something that raises +the motivation to a high level and it + + align:start position:0% +the motivation to a high level and it + + + align:start position:0% +the motivation to a high level and it +does so rapidly + + align:start position:0% + + + + align:start position:0% + +and I've defined the various things + + align:start position:0% +and I've defined the various things + + + align:start position:0% +and I've defined the various things +there uh below + + align:start position:0% +there uh below + + + align:start position:0% +there uh below +now the major difference of course is + + align:start position:0% +now the major difference of course is + + + align:start position:0% +now the major difference of course is +the the way the releasing stimuli are + + align:start position:0% +the the way the releasing stimuli are + + + align:start position:0% +the the way the releasing stimuli are +acting as I pointed + + align:start position:0% +acting as I pointed + + + align:start position:0% +acting as I pointed +out and + + align:start position:0% + + + + align:start position:0% + +uh where these things are in the CNS + + align:start position:0% +uh where these things are in the CNS + + + align:start position:0% +uh where these things are in the CNS +this is very far from any kind of CNS + + align:start position:0% +this is very far from any kind of CNS + + + align:start position:0% +this is very far from any kind of CNS +model it's an analogist model okay + + align:start position:0% +model it's an analogist model okay + + + align:start position:0% +model it's an analogist model okay +uh it's + + align:start position:0% +uh it's + + + align:start position:0% +uh it's +a hydraulic mechanical model + + align:start position:0% +a hydraulic mechanical model + + + align:start position:0% +a hydraulic mechanical model +that unfortunately looks more like a + + align:start position:0% +that unfortunately looks more like a + + + align:start position:0% +that unfortunately looks more like a +flush toilet than other things you can + + align:start position:0% +flush toilet than other things you can + + + align:start position:0% +flush toilet than other things you can +think of and so sometimes Lawrence was + + align:start position:0% +think of and so sometimes Lawrence was + + + align:start position:0% +think of and so sometimes Lawrence was +made fun of for + + align:start position:0% +made fun of for + + + align:start position:0% +made fun of for +this uh but in fact the model was + + align:start position:0% +this uh but in fact the model was + + + align:start position:0% +this uh but in fact the model was +youthful in that it it pointed out + + align:start position:0% +youthful in that it it pointed out + + + align:start position:0% +youthful in that it it pointed out +properties he's basically summarizing + + align:start position:0% +properties he's basically summarizing + + + align:start position:0% +properties he's basically summarizing +properties that he observed for many + + align:start position:0% +properties that he observed for many + + + align:start position:0% +properties that he observed for many +different fixed action + + align:start position:0% +different fixed action + + + align:start position:0% +different fixed action +patterns and the one on the the right + + align:start position:0% +patterns and the one on the the right + + + align:start position:0% +patterns and the one on the the right +does a better job than the one on the + + align:start position:0% + + + + align:start position:0% + +left now if we talk about where these + + align:start position:0% +left now if we talk about where these + + + align:start position:0% +left now if we talk about where these +things are in the brain it's interesting + + align:start position:0% +things are in the brain it's interesting + + + align:start position:0% +things are in the brain it's interesting +because if + + align:start position:0% +because if + + + align:start position:0% +because if +we go here now let's say you were + + align:start position:0% +we go here now let's say you were + + + align:start position:0% +we go here now let's say you were +stimulating the spinal cord or the hind + + align:start position:0% +stimulating the spinal cord or the hind + + + align:start position:0% +stimulating the spinal cord or the hind +brain you can get various components of + + align:start position:0% +brain you can get various components of + + + align:start position:0% +brain you can get various components of +fixed motor patterns okay uh but + + align:start position:0% +fixed motor patterns okay uh but + + + align:start position:0% +fixed motor patterns okay uh but +generally only when the stimulus is on + + align:start position:0% +generally only when the stimulus is on + + + align:start position:0% +generally only when the stimulus is on +you get them so it's not acting at all + + align:start position:0% +you get them so it's not acting at all + + + align:start position:0% +you get them so it's not acting at all +like the action specific potential in + + align:start position:0% +like the action specific potential in + + + align:start position:0% +like the action specific potential in +the reservoir + + align:start position:0% +the reservoir + + + align:start position:0% +the reservoir +here where you get the whole + + align:start position:0% +here where you get the whole + + + align:start position:0% +here where you get the whole +sequence okay + + align:start position:0% +sequence okay + + + align:start position:0% +sequence okay +and and when you suddenly take the + + align:start position:0% +and and when you suddenly take the + + + align:start position:0% +and and when you suddenly take the +stimulus away the action doesn't just + + align:start position:0% +stimulus away the action doesn't just + + + align:start position:0% +stimulus away the action doesn't just +suddenly stop just like in the model + + align:start position:0% +suddenly stop just like in the model + + + align:start position:0% +suddenly stop just like in the model +so + + align:start position:0% + + + + align:start position:0% + +uh so I just summarize that here for low + + align:start position:0% +uh so I just summarize that here for low + + + align:start position:0% +uh so I just summarize that here for low +levels the the behavioral changes occur + + align:start position:0% +levels the the behavioral changes occur + + + align:start position:0% +levels the the behavioral changes occur +only during the periods of stimulation + + align:start position:0% +only during the periods of stimulation + + + align:start position:0% +only during the periods of stimulation +then they + + align:start position:0% +then they + + + align:start position:0% +then they +stop and in fact if you have an animal + + align:start position:0% +stop and in fact if you have an animal + + + align:start position:0% +stop and in fact if you have an animal +that's had a transection of the higher + + align:start position:0% +that's had a transection of the higher + + + align:start position:0% +that's had a transection of the higher +areas of the brain they've been totally + + align:start position:0% +areas of the brain they've been totally + + + align:start position:0% +areas of the brain they've been totally +separated they're no longer influ the + + align:start position:0% +separated they're no longer influ the + + + align:start position:0% +separated they're no longer influ the +hypothalamic region the whole forbrain + + align:start position:0% +hypothalamic region the whole forbrain + + + align:start position:0% +hypothalamic region the whole forbrain +is cut off from those lower regions you + + align:start position:0% +is cut off from those lower regions you + + + align:start position:0% +is cut off from those lower regions you +can still stimulate fixed action + + align:start position:0% +can still stimulate fixed action + + + align:start position:0% +can still stimulate fixed action +patterns but only the motor component + + align:start position:0% +patterns but only the motor component + + + align:start position:0% +patterns but only the motor component +and they just stop immediately just like + + align:start position:0% +and they just stop immediately just like + + + align:start position:0% +and they just stop immediately just like +the effects of electrical stimulation of + + align:start position:0% +the effects of electrical stimulation of + + + align:start position:0% +the effects of electrical stimulation of +those lower levels + + align:start position:0% +those lower levels + + + align:start position:0% +those lower levels +but when you stimulate in the coddle + + align:start position:0% +but when you stimulate in the coddle + + + align:start position:0% +but when you stimulate in the coddle +forbrain there the hypothalamic area + + align:start position:0% +forbrain there the hypothalamic area + + + align:start position:0% +forbrain there the hypothalamic area +then you do illicit + + align:start position:0% +then you do illicit + + + align:start position:0% +then you do illicit +moods that are very very hard to + + align:start position:0% +moods that are very very hard to + + + align:start position:0% +moods that are very very hard to +distinguish + + align:start position:0% +distinguish + + + align:start position:0% +distinguish +from the mood that would occur in a + + align:start position:0% + + + + align:start position:0% + +normally and that's been done for both + + align:start position:0% +normally and that's been done for both + + + align:start position:0% +normally and that's been done for both +the quiet biting attack the predatory + + align:start position:0% +the quiet biting attack the predatory + + + align:start position:0% +the quiet biting attack the predatory +attack of a cat and or the the more + + align:start position:0% +attack of a cat and or the the more + + + align:start position:0% +attack of a cat and or the the more +aggressive defensive attack and you are + + align:start position:0% +aggressive defensive attack and you are + + + align:start position:0% +aggressive defensive attack and you are +all familiar with that the cat that + + align:start position:0% +all familiar with that the cat that + + + align:start position:0% +all familiar with that the cat that +arches its back you know and extends its + + align:start position:0% +arches its back you know and extends its + + + align:start position:0% +arches its back you know and extends its +claws and makes a lot of + + align:start position:0% +claws and makes a lot of + + + align:start position:0% +claws and makes a lot of +noise okay where we call the other one a + + align:start position:0% +noise okay where we call the other one a + + + align:start position:0% +noise okay where we call the other one a +quiet biting attack because he does not + + align:start position:0% +quiet biting attack because he does not + + + align:start position:0% +quiet biting attack because he does not +make noise it's designed specifically to + + align:start position:0% +make noise it's designed specifically to + + + align:start position:0% +make noise it's designed specifically to +kill + + align:start position:0% + + + + align:start position:0% + +prey so I'm just pointing out uh I want + + align:start position:0% +prey so I'm just pointing out uh I want + + + align:start position:0% +prey so I'm just pointing out uh I want +want you to give examples of the effects + + align:start position:0% +want you to give examples of the effects + + + align:start position:0% +want you to give examples of the effects +of the inertia of excitation in animal + + align:start position:0% + + + + align:start position:0% + +behavior think of an example from human + + align:start position:0% +behavior think of an example from human + + + align:start position:0% +behavior think of an example from human +behavior but it occurs with animals too + + align:start position:0% +behavior but it occurs with animals too + + + align:start position:0% +behavior but it occurs with animals too +if you suddenly remove a stimulus you + + align:start position:0% +if you suddenly remove a stimulus you + + + align:start position:0% +if you suddenly remove a stimulus you +elicit the whole you increase the level + + align:start position:0% +elicit the whole you increase the level + + + align:start position:0% +elicit the whole you increase the level +of motivation that remember the + + align:start position:0% +of motivation that remember the + + + align:start position:0% +of motivation that remember the +Lawrence's model on the right there you + + align:start position:0% +Lawrence's model on the right there you + + + align:start position:0% +Lawrence's model on the right there you +you cause the the motivation to go way + + align:start position:0% +you cause the the motivation to go way + + + align:start position:0% +you cause the the motivation to go way +way up if you just sudden L remove that + + align:start position:0% +way up if you just sudden L remove that + + + align:start position:0% +way up if you just sudden L remove that +stimulus the behavior doesn't just go + + align:start position:0% +stimulus the behavior doesn't just go + + + align:start position:0% +stimulus the behavior doesn't just go +away + + align:start position:0% +away + + + align:start position:0% +away +okay I like the example from a Disney + + align:start position:0% +okay I like the example from a Disney + + + align:start position:0% +okay I like the example from a Disney +movie of a bear they show the bear + + align:start position:0% +movie of a bear they show the bear + + + align:start position:0% +movie of a bear they show the bear +that's high on a hill and he's trying to + + align:start position:0% +that's high on a hill and he's trying to + + + align:start position:0% +that's high on a hill and he's trying to +get something in a log a big log and he + + align:start position:0% +get something in a log a big log and he + + + align:start position:0% +get something in a log a big log and he +crawls into the log as far as he can get + + align:start position:0% +crawls into the log as far as he can get + + + align:start position:0% +crawls into the log as far as he can get +and he gets stuck there and then the log + + align:start position:0% +and he gets stuck there and then the log + + + align:start position:0% +and he gets stuck there and then the log +starts rolling down the hill bounding + + align:start position:0% +starts rolling down the hill bounding + + + align:start position:0% +starts rolling down the hill bounding +down the hill until finally it crashes + + align:start position:0% +down the hill until finally it crashes + + + align:start position:0% +down the hill until finally it crashes +against a tree and breaks open the log + + align:start position:0% +against a tree and breaks open the log + + + align:start position:0% +against a tree and breaks open the log +and the bear comes out angry as can be + + align:start position:0% +and the bear comes out angry as can be + + + align:start position:0% +and the bear comes out angry as can be +and he starts swatting he pulls little + + align:start position:0% +and he starts swatting he pulls little + + + align:start position:0% +and he starts swatting he pulls little +trees you know he just like an angry + + align:start position:0% +trees you know he just like an angry + + + align:start position:0% +trees you know he just like an angry +human that you don't get over it + + align:start position:0% +human that you don't get over it + + + align:start position:0% +human that you don't get over it +suddenly even if the stimuli are + + align:start position:0% + + + + align:start position:0% + +gone if something on the TV makes you + + align:start position:0% +gone if something on the TV makes you + + + align:start position:0% +gone if something on the TV makes you +very angry some people have been known + + align:start position:0% +very angry some people have been known + + + align:start position:0% +very angry some people have been known +to break their + + align:start position:0% +to break their + + + align:start position:0% +to break their +TV you know this + + align:start position:0% +TV you know this + + + align:start position:0% +TV you know this +this is the inertia of excitation of a + + align:start position:0% +this is the inertia of excitation of a + + + align:start position:0% +this is the inertia of excitation of a +fixed action pattern okay by this change + + align:start position:0% +fixed action pattern okay by this change + + + align:start position:0% +fixed action pattern okay by this change +in the motivational + + align:start position:0% +in the motivational + + + align:start position:0% +in the motivational +level here on the right that you can + + align:start position:0% +level here on the right that you can + + + align:start position:0% +level here on the right that you can +remove that stimulus there but the + + align:start position:0% +remove that stimulus there but the + + + align:start position:0% +remove that stimulus there but the +reservoir is so full that the action + + align:start position:0% +reservoir is so full that the action + + + align:start position:0% +reservoir is so full that the action +continues for some + + align:start position:0% + + + + align:start position:0% + +time all right + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so you see that with fear with + + align:start position:0% +so you see that with fear with + + + align:start position:0% +so you see that with fear with +aggression with sexual excitement + + align:start position:0% +aggression with sexual excitement + + + align:start position:0% +aggression with sexual excitement +certainly these are the areas certainly + + align:start position:0% +certainly these are the areas certainly + + + align:start position:0% +certainly these are the areas certainly +in human behavior but also in many + + align:start position:0% +in human behavior but also in many + + + align:start position:0% +in human behavior but also in many +animals that you see that the + + align:start position:0% +animals that you see that the + + + align:start position:0% +animals that you see that the +most how can we explain the fact that + + align:start position:0% +most how can we explain the fact that + + + align:start position:0% +most how can we explain the fact that +the urination activities of a male dog + + align:start position:0% +the urination activities of a male dog + + + align:start position:0% +the urination activities of a male dog +often don't depend on the amount of + + align:start position:0% +often don't depend on the amount of + + + align:start position:0% +often don't depend on the amount of +urine in the ladder you say well why do + + align:start position:0% +urine in the ladder you say well why do + + + align:start position:0% +urine in the ladder you say well why do +we urinate well we have an urge to + + align:start position:0% +we urinate well we have an urge to + + + align:start position:0% +we urinate well we have an urge to +urinate because the ladder's full but in + + align:start position:0% +urinate because the ladder's full but in + + + align:start position:0% +urinate because the ladder's full but in +the case of a + + align:start position:0% +the case of a + + + align:start position:0% +the case of a +dog urination has other + + align:start position:0% +dog urination has other + + + align:start position:0% +dog urination has other +functions so there's two very different + + align:start position:0% +functions so there's two very different + + + align:start position:0% +functions so there's two very different +motivations that make at least the male + + align:start position:0% +motivations that make at least the male + + + align:start position:0% +motivations that make at least the male +dog + + align:start position:0% +dog + + + align:start position:0% +dog +urinate and in the case of female cats + + align:start position:0% +urinate and in the case of female cats + + + align:start position:0% +urinate and in the case of female cats +uh in in the case of cats I don't know + + align:start position:0% +uh in in the case of cats I don't know + + + align:start position:0% +uh in in the case of cats I don't know +about I don't think + + align:start position:0% +about I don't think + + + align:start position:0% +about I don't think +dogs uh but what are they + + align:start position:0% +dogs uh but what are they + + + align:start position:0% +dogs uh but what are they +doing why do they hold back they don't + + align:start position:0% +doing why do they hold back they don't + + + align:start position:0% +doing why do they hold back they don't +discharge all their + + align:start position:0% +discharge all their + + + align:start position:0% +discharge all their +urine they need it percent marking + + align:start position:0% +urine they need it percent marking + + + align:start position:0% +urine they need it percent marking +Behavior so that's a separate + + align:start position:0% +Behavior so that's a separate + + + align:start position:0% +Behavior so that's a separate +motivation okay and cats do it too both + + align:start position:0% +motivation okay and cats do it too both + + + align:start position:0% +motivation okay and cats do it too both +male and + + align:start position:0% +male and + + + align:start position:0% +male and +female uh because of the odor these are + + align:start position:0% +female uh because of the odor these are + + + align:start position:0% +female uh because of the odor these are +very old factory animals and + + align:start position:0% +very old factory animals and + + + align:start position:0% +very old factory animals and +they're their whole world is very + + align:start position:0% +they're their whole world is very + + + align:start position:0% +they're their whole world is very +different from ours it is Visual and + + align:start position:0% +different from ours it is Visual and + + + align:start position:0% +different from ours it is Visual and +auditory Lars but much more old factory + + align:start position:0% +auditory Lars but much more old factory + + + align:start position:0% +auditory Lars but much more old factory +they come into an area they + + align:start position:0% +they come into an area they + + + align:start position:0% +they come into an area they +know which other cats which individual + + align:start position:0% +know which other cats which individual + + + align:start position:0% +know which other cats which individual +cats have been in that region and + + align:start position:0% +cats have been in that region and + + + align:start position:0% +cats have been in that region and +whether they were male or female okay + + align:start position:0% +whether they were male or female okay + + + align:start position:0% +whether they were male or female okay +and they leave their + + align:start position:0% + + + + align:start position:0% + +Mark humans sometimes do that too they + + align:start position:0% +Mark humans sometimes do that too they + + + align:start position:0% +Mark humans sometimes do that too they +write on walls and things like + + align:start position:0% +write on walls and things like + + + align:start position:0% +write on walls and things like +that okay + + align:start position:0% + + + + align:start position:0% + +uh let's talk about chains of behavior + + align:start position:0% +uh let's talk about chains of behavior + + + align:start position:0% +uh let's talk about chains of behavior +and then the hierarchy of the system + + align:start position:0% +and then the hierarchy of the system + + + align:start position:0% +and then the hierarchy of the system +systems of fixed action + + align:start position:0% +systems of fixed action + + + align:start position:0% +systems of fixed action +patterns so as an example here I'm + + align:start position:0% +patterns so as an example here I'm + + + align:start position:0% +patterns so as an example here I'm +asking for a description of the chain of + + align:start position:0% +asking for a description of the chain of + + + align:start position:0% +asking for a description of the chain of +behavior pattern shown by newborn + + align:start position:0% +behavior pattern shown by newborn + + + align:start position:0% +behavior pattern shown by newborn +kittens in nursing Behavior it's very + + align:start position:0% +kittens in nursing Behavior it's very + + + align:start position:0% +kittens in nursing Behavior it's very +interesting it's a consistent chain of + + align:start position:0% +interesting it's a consistent chain of + + + align:start position:0% +interesting it's a consistent chain of +behavior that they + + align:start position:0% +behavior that they + + + align:start position:0% +behavior that they +show and normally one Behavior leads to + + align:start position:0% +show and normally one Behavior leads to + + + align:start position:0% +show and normally one Behavior leads to +the next because it leads to the + + align:start position:0% +the next because it leads to the + + + align:start position:0% +the next because it leads to the +stimulus that elicits the next and I've + + align:start position:0% +stimulus that elicits the next and I've + + + align:start position:0% +stimulus that elicits the next and I've +listed them here if he's awake and he's + + align:start position:0% +listed them here if he's awake and he's + + + align:start position:0% +listed them here if he's awake and he's +not suckling he shows this constant to + + align:start position:0% +not suckling he shows this constant to + + + align:start position:0% +not suckling he shows this constant to +and fro sideways sweeping movement of + + align:start position:0% +and fro sideways sweeping movement of + + + align:start position:0% +and fro sideways sweeping movement of +the head and four parts of the body + + align:start position:0% +the head and four parts of the body + + + align:start position:0% +the head and four parts of the body +while he creeps + + align:start position:0% +while he creeps + + + align:start position:0% +while he creeps +forward like no of course he's normally + + align:start position:0% +forward like no of course he's normally + + + align:start position:0% +forward like no of course he's normally +near the + + align:start position:0% +near the + + + align:start position:0% +near the +mother and if he touches a solid + + align:start position:0% +mother and if he touches a solid + + + align:start position:0% +mother and if he touches a solid +vertical surface even if it's not the + + align:start position:0% +vertical surface even if it's not the + + + align:start position:0% +vertical surface even if it's not the +mother he snuggles up to it and + + align:start position:0% +mother he snuggles up to it and + + + align:start position:0% +mother he snuggles up to it and +maintains contact while he continues + + align:start position:0% +maintains contact while he continues + + + align:start position:0% +maintains contact while he continues +that sweeping + + align:start position:0% +that sweeping + + + align:start position:0% +that sweeping +motion it's designed of course even + + align:start position:0% +motion it's designed of course even + + + align:start position:0% +motion it's designed of course even +though it's a fixed motor pattern uh + + align:start position:0% +though it's a fixed motor pattern uh + + + align:start position:0% +though it's a fixed motor pattern uh +it's designed to find the teeth of the + + align:start position:0% +it's designed to find the teeth of the + + + align:start position:0% +it's designed to find the teeth of the +mother so if he contacts fur he stops + + align:start position:0% +mother so if he contacts fur he stops + + + align:start position:0% +mother so if he contacts fur he stops +his Forward Motion okay but he continues + + align:start position:0% +his Forward Motion okay but he continues + + + align:start position:0% +his Forward Motion okay but he continues +the sweeping motions his nose pressed + + align:start position:0% +the sweeping motions his nose pressed + + + align:start position:0% +the sweeping motions his nose pressed +against the fur if he touches a bare + + align:start position:0% +against the fur if he touches a bare + + + align:start position:0% +against the fur if he touches a bare +spot then he ceases the sweeping motion + + align:start position:0% +spot then he ceases the sweeping motion + + + align:start position:0% +spot then he ceases the sweeping motion +and initiates a different Behavior it's + + align:start position:0% +and initiates a different Behavior it's + + + align:start position:0% +and initiates a different Behavior it's +kind of snapping he's trying to get the + + align:start position:0% +kind of snapping he's trying to get the + + + align:start position:0% +kind of snapping he's trying to get the +tee in his mouth so he finds it he stops + + align:start position:0% +tee in his mouth so he finds it he stops + + + align:start position:0% +tee in his mouth so he finds it he stops +his other movements and that initiates + + align:start position:0% +his other movements and that initiates + + + align:start position:0% +his other movements and that initiates +the sucking Behavior sucking behavior + + align:start position:0% +the sucking Behavior sucking behavior + + + align:start position:0% +the sucking Behavior sucking behavior +and also melt treading while he's + + align:start position:0% +and also melt treading while he's + + + align:start position:0% +and also melt treading while he's +sucking he's you see this movement of + + align:start position:0% +sucking he's you see this movement of + + + align:start position:0% +sucking he's you see this movement of +the front + + align:start position:0% + + + + align:start position:0% + +paws so each motor pattern serves as + + align:start position:0% +paws so each motor pattern serves as + + + align:start position:0% +paws so each motor pattern serves as +competitive behavior for the next fixed + + align:start position:0% +competitive behavior for the next fixed + + + align:start position:0% +competitive behavior for the next fixed +action + + align:start position:0% +action + + + align:start position:0% +action +pattern or I would say the next + + align:start position:0% +pattern or I would say the next + + + align:start position:0% +pattern or I would say the next +component of the + + align:start position:0% +component of the + + + align:start position:0% +component of the +sequence because these are always + + align:start position:0% + + + + align:start position:0% + +linked but Lawrence sees them as + + align:start position:0% +linked but Lawrence sees them as + + + align:start position:0% +linked but Lawrence sees them as +a very different fixed action + + align:start position:0% +a very different fixed action + + + align:start position:0% +a very different fixed action +patterns + + align:start position:0% +patterns + + + align:start position:0% +patterns +uh because in fact you don't have to + + align:start position:0% +uh because in fact you don't have to + + + align:start position:0% +uh because in fact you don't have to +have the whole sequence if you put the + + align:start position:0% +have the whole sequence if you put the + + + align:start position:0% +have the whole sequence if you put the +an the animal right next to the mother + + align:start position:0% +an the animal right next to the mother + + + align:start position:0% +an the animal right next to the mother +then he won't show the earlier compounds + + align:start position:0% +then he won't show the earlier compounds + + + align:start position:0% +then he won't show the earlier compounds +he does not have to go through the + + align:start position:0% +he does not have to go through the + + + align:start position:0% +he does not have to go through the +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +ones because they're + + align:start position:0% +ones because they're + + + align:start position:0% +ones because they're +all somewhat independent fixed action + + align:start position:0% +all somewhat independent fixed action + + + align:start position:0% +all somewhat independent fixed action +patterns but they're normally linked + + align:start position:0% +patterns but they're normally linked + + + align:start position:0% +patterns but they're normally linked +because of the situation + + align:start position:0% + + + + align:start position:0% + +and Timber had described these kinds of + + align:start position:0% +and Timber had described these kinds of + + + align:start position:0% +and Timber had described these kinds of +things as examples of the hierarchical + + align:start position:0% +things as examples of the hierarchical + + + align:start position:0% +things as examples of the hierarchical +organization of + + align:start position:0% +organization of + + + align:start position:0% +organization of +instinct and he he has some very + + align:start position:0% +instinct and he he has some very + + + align:start position:0% +instinct and he he has some very +well-known diagrams that you should be + + align:start position:0% +well-known diagrams that you should be + + + align:start position:0% +well-known diagrams that you should be +familiar + + align:start position:0% +familiar + + + align:start position:0% +familiar +with + + align:start position:0% +with + + + align:start position:0% +with +uh he shows a view of innate releasing + + align:start position:0% +uh he shows a view of innate releasing + + + align:start position:0% +uh he shows a view of innate releasing +mechanisms that are quite a bit + + align:start position:0% +mechanisms that are quite a bit + + + align:start position:0% +mechanisms that are quite a bit +different from Lawrence they did work + + align:start position:0% +different from Lawrence they did work + + + align:start position:0% +different from Lawrence they did work +together some but they had a different + + align:start position:0% +together some but they had a different + + + align:start position:0% +together some but they had a different +way of picturing it + + align:start position:0% +way of picturing it + + + align:start position:0% +way of picturing it +uh and you can see that he doesn't + + align:start position:0% +uh and you can see that he doesn't + + + align:start position:0% +uh and you can see that he doesn't +explain some of the aspects that + + align:start position:0% +explain some of the aspects that + + + align:start position:0% +explain some of the aspects that +Lawrence was dealing with all that stuff + + align:start position:0% +Lawrence was dealing with all that stuff + + + align:start position:0% +Lawrence was dealing with all that stuff +about the inertia behavior and so forth + + align:start position:0% +about the inertia behavior and so forth + + + align:start position:0% +about the inertia behavior and so forth +he didn't try to deal with but he did + + align:start position:0% +he didn't try to deal with but he did + + + align:start position:0% +he didn't try to deal with but he did +deal with the hierarchy in this case we + + align:start position:0% +deal with the hierarchy in this case we + + + align:start position:0% +deal with the hierarchy in this case we +just take one component of it + + align:start position:0% +just take one component of it + + + align:start position:0% +just take one component of it +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay and this is just + + align:start position:0% +okay and this is just + + + align:start position:0% +okay and this is just +uh for example um and we're dealing with + + align:start position:0% +uh for example um and we're dealing with + + + align:start position:0% +uh for example um and we're dealing with +an aspect of reproductive Behavior + + align:start position:0% +an aspect of reproductive Behavior + + + align:start position:0% +an aspect of reproductive Behavior +hormones provide a major + + align:start position:0% +hormones provide a major + + + align:start position:0% +hormones provide a major +input + + align:start position:0% +input + + + align:start position:0% +input +uh the higher level could be coming from + + align:start position:0% +uh the higher level could be coming from + + + align:start position:0% +uh the higher level could be coming from +the visual system that signals time of + + align:start position:0% +the visual system that signals time of + + + align:start position:0% +the visual system that signals time of +year + + align:start position:0% +year + + + align:start position:0% +year +uh other input that increase that + + align:start position:0% +uh other input that increase that + + + align:start position:0% +uh other input that increase that +motivation and then unlike Lawrence he + + align:start position:0% +motivation and then unlike Lawrence he + + + align:start position:0% +motivation and then unlike Lawrence he +has a + + align:start position:0% +has a + + + align:start position:0% +has a +block preventing the continuous + + align:start position:0% +block preventing the continuous + + + align:start position:0% +block preventing the continuous +discharge of the motor paddings + + align:start position:0% +discharge of the motor paddings + + + align:start position:0% +discharge of the motor paddings +and the innate releasing + + align:start position:0% + + + + align:start position:0% + +mechanism then the stimulus that + + align:start position:0% +mechanism then the stimulus that + + + align:start position:0% +mechanism then the stimulus that +activates the innate releasing mechanism + + align:start position:0% +activates the innate releasing mechanism + + + align:start position:0% +activates the innate releasing mechanism +its function is simply to remove that + + align:start position:0% +its function is simply to remove that + + + align:start position:0% +its function is simply to remove that +block and then the block once it's + + align:start position:0% +block and then the block once it's + + + align:start position:0% +block and then the block once it's +removed can elicit a whole + + align:start position:0% +removed can elicit a whole + + + align:start position:0% +removed can elicit a whole +series and which one would be first well + + align:start position:0% +series and which one would be first well + + + align:start position:0% +series and which one would be first well +the one with the lowest threshold and + + align:start position:0% +the one with the lowest threshold and + + + align:start position:0% +the one with the lowest threshold and +normally that's ative + + align:start position:0% +normally that's ative + + + align:start position:0% +normally that's ative +Behavior okay and these different + + align:start position:0% +Behavior okay and these different + + + align:start position:0% +Behavior okay and these different +components of the fixed action pattern + + align:start position:0% +components of the fixed action pattern + + + align:start position:0% +components of the fixed action pattern +are normally inhibiting each other and + + align:start position:0% +are normally inhibiting each other and + + + align:start position:0% +are normally inhibiting each other and +this shows a more complete model where + + align:start position:0% +this shows a more complete model where + + + align:start position:0% +this shows a more complete model where +he shows uh male stick stickleback + + align:start position:0% +he shows uh male stick stickleback + + + align:start position:0% +he shows uh male stick stickleback +reproductive Behavior basically the + + align:start position:0% +reproductive Behavior basically the + + + align:start position:0% +reproductive Behavior basically the +whole hierarchy starting with hormones + + align:start position:0% +whole hierarchy starting with hormones + + + align:start position:0% +whole hierarchy starting with hormones +with a spring + + align:start position:0% +with a spring + + + align:start position:0% +with a spring +migration uh the nature of the water has + + align:start position:0% +migration uh the nature of the water has + + + align:start position:0% +migration uh the nature of the water has +an + + align:start position:0% +an + + + align:start position:0% +an +influence uh the plants and the vicinity + + align:start position:0% +influence uh the plants and the vicinity + + + align:start position:0% +influence uh the plants and the vicinity +and various internal factors and then + + align:start position:0% +and various internal factors and then + + + align:start position:0% +and various internal factors and then +there's the block the innate releasing + + align:start position:0% +there's the block the innate releasing + + + align:start position:0% +there's the block the innate releasing +mechanism that can remove the block and + + align:start position:0% +mechanism that can remove the block and + + + align:start position:0% +mechanism that can remove the block and +start these various behaviors and note + + align:start position:0% +start these various behaviors and note + + + align:start position:0% +start these various behaviors and note +he has the mutual inhibition shown by + + align:start position:0% +he has the mutual inhibition shown by + + + align:start position:0% +he has the mutual inhibition shown by +the double arrows here he has fighting + + align:start position:0% +the double arrows here he has fighting + + + align:start position:0% +the double arrows here he has fighting +nesting courtship and parental Behavior + + align:start position:0% +nesting courtship and parental Behavior + + + align:start position:0% +nesting courtship and parental Behavior +each with somewhat different stimuli and + + align:start position:0% +each with somewhat different stimuli and + + + align:start position:0% +each with somewhat different stimuli and +so depending on the stimuli there uh + + align:start position:0% +so depending on the stimuli there uh + + + align:start position:0% +so depending on the stimuli there uh +these will be + + align:start position:0% +these will be + + + align:start position:0% +these will be +discharged and then he shows the lower + + align:start position:0% +discharged and then he shows the lower + + + align:start position:0% +discharged and then he shows the lower +levels + + align:start position:0% +levels + + + align:start position:0% +levels +too the level of the actual action so + + align:start position:0% +too the level of the actual action so + + + align:start position:0% +too the level of the actual action so +here for fighting Behavior he has the + + align:start position:0% +here for fighting Behavior he has the + + + align:start position:0% +here for fighting Behavior he has the +displaying the biting and the + + align:start position:0% +displaying the biting and the + + + align:start position:0% +displaying the biting and the +chasing okay and if if you get the + + align:start position:0% +chasing okay and if if you get the + + + align:start position:0% +chasing okay and if if you get the +display hurrying uh then you get whole + + align:start position:0% +display hurrying uh then you get whole + + + align:start position:0% +display hurrying uh then you get whole +fins rays of one fin muscle fibers of + + align:start position:0% +fins rays of one fin muscle fibers of + + + align:start position:0% +fins rays of one fin muscle fibers of +one Ray and motor + + align:start position:0% +one Ray and motor + + + align:start position:0% +one Ray and motor +neurons for for one the muscle fiber so + + align:start position:0% +neurons for for one the muscle fiber so + + + align:start position:0% +neurons for for one the muscle fiber so +he shows the whole hierarchy here and + + align:start position:0% +he shows the whole hierarchy here and + + + align:start position:0% +he shows the whole hierarchy here and +this is often reproduced because + + align:start position:0% +this is often reproduced because + + + align:start position:0% +this is often reproduced because +neuroscientists like it because it sort + + align:start position:0% +neuroscientists like it because it sort + + + align:start position:0% +neuroscientists like it because it sort +of fits the hierarchical organization of + + align:start position:0% +of fits the hierarchical organization of + + + align:start position:0% +of fits the hierarchical organization of +the nervous system and this shows a + + align:start position:0% +the nervous system and this shows a + + + align:start position:0% +the nervous system and this shows a +functional picture of that + + align:start position:0% + + + + align:start position:0% + +okay and I'm + + align:start position:0% +okay and I'm + + + align:start position:0% +okay and I'm +uh this is the level of ethology up here + + align:start position:0% +uh this is the level of ethology up here + + + align:start position:0% +uh this is the level of ethology up here +and here we're at the level of + + align:start position:0% +and here we're at the level of + + + align:start position:0% +and here we're at the level of +neurophysiology they study different + + align:start position:0% +neurophysiology they study different + + + align:start position:0% +neurophysiology they study different +aspects of it but in fact the + + align:start position:0% +aspects of it but in fact the + + + align:start position:0% +aspects of it but in fact the +physiologists working on hypothalamus + + align:start position:0% +physiologists working on hypothalamus + + + align:start position:0% +physiologists working on hypothalamus +have also studied many of these + + align:start position:0% + + + + align:start position:0% + +things so the major difference then + + align:start position:0% +things so the major difference then + + + align:start position:0% +things so the major difference then +between the Lawrence model and the + + align:start position:0% +between the Lawrence model and the + + + align:start position:0% +between the Lawrence model and the +tinbergen model I've listed for you here + + align:start position:0% +tinbergen model I've listed for you here + + + align:start position:0% +tinbergen model I've listed for you here +here obviously tinbergen's view is the + + align:start position:0% +here obviously tinbergen's view is the + + + align:start position:0% +here obviously tinbergen's view is the +broader + + align:start position:0% +broader + + + align:start position:0% +broader +one uh it looks more like an information + + align:start position:0% +one uh it looks more like an information + + + align:start position:0% +one uh it looks more like an information +flow scheme uh but Lawrence by focusing + + align:start position:0% +flow scheme uh but Lawrence by focusing + + + align:start position:0% +flow scheme uh but Lawrence by focusing +on dynamics of the of the drive State + + align:start position:0% +on dynamics of the of the drive State + + + align:start position:0% +on dynamics of the of the drive State +the action specific potential and the + + align:start position:0% +the action specific potential and the + + + align:start position:0% +the action specific potential and the +innate releasing + + align:start position:0% +innate releasing + + + align:start position:0% +innate releasing +mechanism + + align:start position:0% + + + + align:start position:0% + +uh it showing very different aspects of + + align:start position:0% +uh it showing very different aspects of + + + align:start position:0% +uh it showing very different aspects of +these the properties of innate behavior + + align:start position:0% +these the properties of innate behavior + + + align:start position:0% +these the properties of innate behavior +and here I just point out the strengths + + align:start position:0% +and here I just point out the strengths + + + align:start position:0% +and here I just point out the strengths +and + + align:start position:0% + + + + align:start position:0% + +weaknesses and I I also note that + + align:start position:0% +weaknesses and I I also note that + + + align:start position:0% +weaknesses and I I also note that +tinbergen's model has been more popular + + align:start position:0% +tinbergen's model has been more popular + + + align:start position:0% +tinbergen's model has been more popular +among the the neural + + align:start position:0% +among the the neural + + + align:start position:0% +among the the neural +people um but it was the Lawrence view + + align:start position:0% +people um but it was the Lawrence view + + + align:start position:0% +people um but it was the Lawrence view +that was actually used in the modeling + + align:start position:0% +that was actually used in the modeling + + + align:start position:0% +that was actually used in the modeling +of real Behavior patterns in + + align:start position:0% +of real Behavior patterns in + + + align:start position:0% +of real Behavior patterns in +animals + + align:start position:0% +animals + + + align:start position:0% +animals +uh in the work of uh Bruce plumberg here + + align:start position:0% +uh in the work of uh Bruce plumberg here + + + align:start position:0% +uh in the work of uh Bruce plumberg here +that might when he was doing that in the + + align:start position:0% +that might when he was doing that in the + + + align:start position:0% +that might when he was doing that in the +media lab + + align:start position:0% + + + + align:start position:0% + +okay so let's go + + align:start position:0% +okay so let's go + + + align:start position:0% +okay so let's go +to the discussion of Lawrence of the + + align:start position:0% +to the discussion of Lawrence of the + + + align:start position:0% +to the discussion of Lawrence of the +work of Barons and this is his work on + + align:start position:0% +work of Barons and this is his work on + + + align:start position:0% +work of Barons and this is his work on +the female Digger was because it points + + align:start position:0% +the female Digger was because it points + + + align:start position:0% +the female Digger was because it points +out another aspect of innate behavior + + align:start position:0% +out another aspect of innate behavior + + + align:start position:0% +out another aspect of innate behavior +that I think is quite important and this + + align:start position:0% +that I think is quite important and this + + + align:start position:0% +that I think is quite important and this +uh we're going to come back to the + + align:start position:0% +uh we're going to come back to the + + + align:start position:0% +uh we're going to come back to the +digger wasp next week when we read uh uh + + align:start position:0% +digger wasp next week when we read uh uh + + + align:start position:0% +digger wasp next week when we read uh uh +little bit from tinbergen and his + + align:start position:0% +little bit from tinbergen and his + + + align:start position:0% +little bit from tinbergen and his +studies of uh + + align:start position:0% +studies of uh + + + align:start position:0% +studies of uh +orienting uh behavior in that that wasp + + align:start position:0% +orienting uh behavior in that that wasp + + + align:start position:0% +orienting uh behavior in that that wasp +how does he find + + align:start position:0% +how does he find + + + align:start position:0% +how does he find +things okay + + align:start position:0% + + + + align:start position:0% + +so he's he's doing experiments on the + + align:start position:0% +so he's he's doing experiments on the + + + align:start position:0% +so he's he's doing experiments on the +influence of inspections of the nest by + + align:start position:0% +influence of inspections of the nest by + + + align:start position:0% +influence of inspections of the nest by +the + + align:start position:0% +the + + + align:start position:0% +the +WASP it's a behavior that has a lot of + + align:start position:0% +WASP it's a behavior that has a lot of + + + align:start position:0% +WASP it's a behavior that has a lot of +plasticity okay and uh this is what this + + align:start position:0% +plasticity okay and uh this is what this + + + align:start position:0% +plasticity okay and uh this is what this +is what the digger wasp is like and note + + align:start position:0% +is what the digger wasp is like and note + + + align:start position:0% +is what the digger wasp is like and note +there's a hole in the sand and she's + + align:start position:0% +there's a hole in the sand and she's + + + align:start position:0% +there's a hole in the sand and she's +made that hole and she it's basically a + + align:start position:0% +made that hole and she it's basically a + + + align:start position:0% +made that hole and she it's basically a +nest she makes nests in the sand and + + align:start position:0% +nest she makes nests in the sand and + + + align:start position:0% +nest she makes nests in the sand and +little holes in the + + align:start position:0% +little holes in the + + + align:start position:0% +little holes in the +sand and she digs a separate hole for + + align:start position:0% +sand and she digs a separate hole for + + + align:start position:0% +sand and she digs a separate hole for +every egg She + + align:start position:0% + + + + align:start position:0% + +lays and she has + + align:start position:0% +lays and she has + + + align:start position:0% +lays and she has +to the egg will hatch lar comes out and + + align:start position:0% +to the egg will hatch lar comes out and + + + align:start position:0% +to the egg will hatch lar comes out and +when the lar comes out they have to have + + align:start position:0% +when the lar comes out they have to have + + + align:start position:0% +when the lar comes out they have to have +food right away so + + align:start position:0% +food right away so + + + align:start position:0% +food right away so +she + + align:start position:0% +she + + + align:start position:0% +she +catches insects this wasp is catching + + align:start position:0% +catches insects this wasp is catching + + + align:start position:0% +catches insects this wasp is catching +little insects and worms and bringing + + align:start position:0% +little insects and worms and bringing + + + align:start position:0% +little insects and worms and bringing +them killing them and bringing them + + align:start position:0% +them killing them and bringing them + + + align:start position:0% +them killing them and bringing them +putting them in these + + align:start position:0% +putting them in these + + + align:start position:0% +putting them in these +nests but she doesn't have just one Nest + + align:start position:0% +nests but she doesn't have just one Nest + + + align:start position:0% +nests but she doesn't have just one Nest +she has a bunch of them and so when she + + align:start position:0% +she has a bunch of them and so when she + + + align:start position:0% +she has a bunch of them and so when she +comes to a + + align:start position:0% +comes to a + + + align:start position:0% +comes to a +nest she inspect her first task is just + + align:start position:0% +nest she inspect her first task is just + + + align:start position:0% +nest she inspect her first task is just +to inspect + + align:start position:0% +to inspect + + + align:start position:0% +to inspect +it and if it's already got some food + + align:start position:0% +it and if it's already got some food + + + align:start position:0% +it and if it's already got some food +there then she goes + + align:start position:0% +there then she goes + + + align:start position:0% +there then she goes +on and if it's + + align:start position:0% +on and if it's + + + align:start position:0% +on and if it's +empty then she will fly off and she will + + align:start position:0% +empty then she will fly off and she will + + + align:start position:0% +empty then she will fly off and she will +bring food back and she has to remember + + align:start position:0% +bring food back and she has to remember + + + align:start position:0% +bring food back and she has to remember +which Nest it was and she does she does + + align:start position:0% +which Nest it was and she does she does + + + align:start position:0% +which Nest it was and she does she does +does it pretty + + align:start position:0% +does it pretty + + + align:start position:0% +does it pretty +accurately + + align:start position:0% +accurately + + + align:start position:0% +accurately +okay and she can have a a lot of + + align:start position:0% +okay and she can have a a lot of + + + align:start position:0% +okay and she can have a a lot of +different nests so when you look at the + + align:start position:0% +different nests so when you look at the + + + align:start position:0% +different nests so when you look at the +whole whole situation it seems like + + align:start position:0% +whole whole situation it seems like + + + align:start position:0% +whole whole situation it seems like +quite complex behavior that obviously + + align:start position:0% +quite complex behavior that obviously + + + align:start position:0% +quite complex behavior that obviously +involves some learning and yet the whole + + align:start position:0% +involves some learning and yet the whole + + + align:start position:0% +involves some learning and yet the whole +structure is innate behavior but with + + align:start position:0% +structure is innate behavior but with + + + align:start position:0% +structure is innate behavior but with +these specific things she has to + + align:start position:0% +these specific things she has to + + + align:start position:0% +these specific things she has to +remember in order to carry out the whole + + align:start position:0% + + + + align:start position:0% + +sequence so what she detects in the nest + + align:start position:0% +sequence so what she detects in the nest + + + align:start position:0% +sequence so what she detects in the nest +determines her next Behavior looks like + + align:start position:0% +determines her next Behavior looks like + + + align:start position:0% +determines her next Behavior looks like +my words didn't all copy + + align:start position:0% +my words didn't all copy + + + align:start position:0% +my words didn't all copy +there so the behavior sequences are + + align:start position:0% +there so the behavior sequences are + + + align:start position:0% +there so the behavior sequences are +Complicated by the fact that she digs + + align:start position:0% +Complicated by the fact that she digs + + + align:start position:0% +Complicated by the fact that she digs +and uses multip + + align:start position:0% + + + + align:start position:0% + +nest and that LE LED uh in general + + align:start position:0% +nest and that LE LED uh in general + + + align:start position:0% +nest and that LE LED uh in general +motivational States underlying the + + align:start position:0% +motivational States underlying the + + + align:start position:0% +motivational States underlying the +feeding Behavior chicks and geese also + + align:start position:0% +feeding Behavior chicks and geese also + + + align:start position:0% +feeding Behavior chicks and geese also +show this relative hierarchy of moods + + align:start position:0% +show this relative hierarchy of moods + + + align:start position:0% +show this relative hierarchy of moods +and a good example is the feeding of + + align:start position:0% +and a good example is the feeding of + + + align:start position:0% +and a good example is the feeding of +ducks which we we talked about that a + + align:start position:0% +ducks which we we talked about that a + + + align:start position:0% +ducks which we we talked about that a +little bit but we didn't describe this + + align:start position:0% +little bit but we didn't describe this + + + align:start position:0% +little bit but we didn't describe this +Behavior the upending behavior of ducks + + align:start position:0% +Behavior the upending behavior of ducks + + + align:start position:0% +Behavior the upending behavior of ducks +and geese what is + + align:start position:0% +and geese what is + + + align:start position:0% +and geese what is +upending have you ever watched ducks or + + align:start position:0% +upending have you ever watched ducks or + + + align:start position:0% +upending have you ever watched ducks or +geese feeding in a pond uh much of the + + align:start position:0% +geese feeding in a pond uh much of the + + + align:start position:0% +geese feeding in a pond uh much of the +time you only see their + + align:start position:0% +time you only see their + + + align:start position:0% +time you only see their +tail they're upended they're they're + + align:start position:0% +tail they're upended they're they're + + + align:start position:0% +tail they're upended they're they're +looking for something down below okay + + align:start position:0% +looking for something down below okay + + + align:start position:0% +looking for something down below okay +and that's how they + + align:start position:0% +and that's how they + + + align:start position:0% +and that's how they +feed if you feed the geese or the ducks + + align:start position:0% +feed if you feed the geese or the ducks + + + align:start position:0% +feed if you feed the geese or the ducks +on the + + align:start position:0% +on the + + + align:start position:0% +on the +ground uh then they wouldn't have to do + + align:start position:0% +ground uh then they wouldn't have to do + + + align:start position:0% +ground uh then they wouldn't have to do +that right ah but they're highly + + align:start position:0% +that right ah but they're highly + + + align:start position:0% +that right ah but they're highly +motivated to do upending see it's a + + align:start position:0% +motivated to do upending see it's a + + + align:start position:0% +motivated to do upending see it's a +separate + + align:start position:0% +separate + + + align:start position:0% +separate +motivation so if you deprive them of + + align:start position:0% +motivation so if you deprive them of + + + align:start position:0% +motivation so if you deprive them of +food they will go out and + + align:start position:0% +food they will go out and + + + align:start position:0% +food they will go out and +upend okay they're not they're + + align:start position:0% +upend okay they're not they're + + + align:start position:0% +upend okay they're not they're +feeding because they want to upend + + align:start position:0% +feeding because they want to upend + + + align:start position:0% +feeding because they want to upend +they're not upending in order to feed + + align:start position:0% +they're not upending in order to feed + + + align:start position:0% +they're not upending in order to feed +and that's similar to what we talked + + align:start position:0% +and that's similar to what we talked + + + align:start position:0% +and that's similar to what we talked +about before when we talked about the + + align:start position:0% +about before when we talked about the + + + align:start position:0% +about before when we talked about the +Starling poking into things he's so + + align:start position:0% +Starling poking into things he's so + + + align:start position:0% +Starling poking into things he's so +highly motivated to poke that even if + + align:start position:0% +highly motivated to poke that even if + + + align:start position:0% +highly motivated to poke that even if +he's well fed he will do it and + + align:start position:0% +he's well fed he will do it and + + + align:start position:0% +he's well fed he will do it and +similarly the cactus Finch will still + + align:start position:0% +similarly the cactus Finch will still + + + align:start position:0% +similarly the cactus Finch will still +find a cactus spine and poke in the + + align:start position:0% +find a cactus spine and poke in the + + + align:start position:0% +find a cactus spine and poke in the +things cuz he's high even if he's + + align:start position:0% +things cuz he's high even if he's + + + align:start position:0% +things cuz he's high even if he's +wellfed because he's highly motivated to + + align:start position:0% +wellfed because he's highly motivated to + + + align:start position:0% +wellfed because he's highly motivated to +do + + align:start position:0% + + + + align:start position:0% + +that so well-fed Birds deprived of + + align:start position:0% +that so well-fed Birds deprived of + + + align:start position:0% +that so well-fed Birds deprived of +upending um we'll do + + align:start position:0% +upending um we'll do + + + align:start position:0% +upending um we'll do +that here's the picture of what it looks + + align:start position:0% +that here's the picture of what it looks + + + align:start position:0% +that here's the picture of what it looks +like and two ducks + + align:start position:0% + + + + align:start position:0% + +upending + + align:start position:0% + + + + align:start position:0% + +and I just point out here that the + + align:start position:0% +and I just point out here that the + + + align:start position:0% +and I just point out here that the +action specific potential for that + + align:start position:0% +action specific potential for that + + + align:start position:0% +action specific potential for that +behavior is separate than for + + align:start position:0% + + + + align:start position:0% + +Hunger so if you deprive them of it they + + align:start position:0% +Hunger so if you deprive them of it they + + + align:start position:0% +Hunger so if you deprive them of it they +will show the + + align:start position:0% + + + + align:start position:0% + +behavior Lawrence has this interesting + + align:start position:0% +behavior Lawrence has this interesting + + + align:start position:0% +behavior Lawrence has this interesting +little discussion of why the + + align:start position:0% +little discussion of why the + + + align:start position:0% +little discussion of why the +head which he says contains the Locust + + align:start position:0% +head which he says contains the Locust + + + align:start position:0% +head which he says contains the Locust +of superior command had to e be invented + + align:start position:0% +of superior command had to e be invented + + + align:start position:0% +of superior command had to e be invented +in evolution + + align:start position:0% +in evolution + + + align:start position:0% +in evolution +so how is the + + align:start position:0% + + + + align:start position:0% + +function has I'm asking has the function + + align:start position:0% +function has I'm asking has the function + + + align:start position:0% +function has I'm asking has the function +of the head ganglion changed in higher + + align:start position:0% +of the head ganglion changed in higher + + + align:start position:0% +of the head ganglion changed in higher +vertebrates with respect to fixed action + + align:start position:0% +vertebrates with respect to fixed action + + + align:start position:0% +vertebrates with respect to fixed action +patterns and that's an interesting + + align:start position:0% +patterns and that's an interesting + + + align:start position:0% +patterns and that's an interesting +question Lawrence says the head had to + + align:start position:0% +question Lawrence says the head had to + + + align:start position:0% +question Lawrence says the head had to +evolve to limit Behavior to one motor + + align:start position:0% +evolve to limit Behavior to one motor + + + align:start position:0% +evolve to limit Behavior to one motor +pattern at a + + align:start position:0% + + + + align:start position:0% + +time it was to embody the innate + + align:start position:0% +time it was to embody the innate + + + align:start position:0% +time it was to embody the innate +releasing mechanisms also because most + + align:start position:0% +releasing mechanisms also because most + + + align:start position:0% +releasing mechanisms also because most +innate releasing mechanisms involve + + align:start position:0% +innate releasing mechanisms involve + + + align:start position:0% +innate releasing mechanisms involve +stimuli coming into the head and the + + align:start position:0% +stimuli coming into the head and the + + + align:start position:0% +stimuli coming into the head and the +stimuli come in through the cranial + + align:start position:0% +stimuli come in through the cranial + + + align:start position:0% +stimuli come in through the cranial +nerves most of them do not come in + + align:start position:0% +nerves most of them do not come in + + + align:start position:0% +nerves most of them do not come in +through the spinal nerves + + align:start position:0% +through the spinal nerves + + + align:start position:0% +through the spinal nerves +okay there are some components for + + align:start position:0% +okay there are some components for + + + align:start position:0% +okay there are some components for +example in + + align:start position:0% +example in + + + align:start position:0% +example in +that nursing behavior of the the kitten + + align:start position:0% +that nursing behavior of the the kitten + + + align:start position:0% +that nursing behavior of the the kitten +looking for the opportunity to nurse + + align:start position:0% +looking for the opportunity to nurse + + + align:start position:0% +looking for the opportunity to nurse +that do come in through the spinal cord + + align:start position:0% +that do come in through the spinal cord + + + align:start position:0% +that do come in through the spinal cord +but most of them are coming in through + + align:start position:0% +but most of them are coming in through + + + align:start position:0% +but most of them are coming in through +the + + align:start position:0% +the + + + align:start position:0% +the +head + + align:start position:0% +head + + + align:start position:0% +head +then I'm asking here how the function + + align:start position:0% +then I'm asking here how the function + + + align:start position:0% +then I'm asking here how the function +has changed in higher vertebrates I + + align:start position:0% +has changed in higher vertebrates I + + + align:start position:0% +has changed in higher vertebrates I +would say that the main thing that's + + align:start position:0% +would say that the main thing that's + + + align:start position:0% +would say that the main thing that's +been changing is increased linkage + + align:start position:0% +been changing is increased linkage + + + align:start position:0% +been changing is increased linkage +between innate and learned aspects of + + align:start position:0% +between innate and learned aspects of + + + align:start position:0% +between innate and learned aspects of +behavior and that reaches a peak in + + align:start position:0% +behavior and that reaches a peak in + + + align:start position:0% +behavior and that reaches a peak in +humans uh but it's very prominent in + + align:start position:0% +humans uh but it's very prominent in + + + align:start position:0% +humans uh but it's very prominent in +other other + + align:start position:0% +other other + + + align:start position:0% +other other +animals uh and the other is initiation + + align:start position:0% +animals uh and the other is initiation + + + align:start position:0% +animals uh and the other is initiation +of behavior + + align:start position:0% +of behavior + + + align:start position:0% +of behavior +patterns by learn + + align:start position:0% +patterns by learn + + + align:start position:0% +patterns by learn +motivations motivations can be learned + + align:start position:0% +motivations motivations can be learned + + + align:start position:0% +motivations motivations can be learned +okay and uh acquired motivations are + + align:start position:0% +okay and uh acquired motivations are + + + align:start position:0% +okay and uh acquired motivations are +common we all know about of course some + + align:start position:0% +common we all know about of course some + + + align:start position:0% +common we all know about of course some +of the the bad ones The Addictive + + align:start position:0% +of the the bad ones The Addictive + + + align:start position:0% +of the the bad ones The Addictive +behaviors but there are many different + + align:start position:0% +behaviors but there are many different + + + align:start position:0% +behaviors but there are many different +motivations we become highly motivated + + align:start position:0% +motivations we become highly motivated + + + align:start position:0% +motivations we become highly motivated +to do certain tasks okay well that was + + align:start position:0% +to do certain tasks okay well that was + + + align:start position:0% +to do certain tasks okay well that was +not we didn't carry that with us from + + align:start position:0% +not we didn't carry that with us from + + + align:start position:0% +not we didn't carry that with us from +the uterus + + align:start position:0% + + + + align:start position:0% + +okay but also our cognitive level + + align:start position:0% +okay but also our cognitive level + + + align:start position:0% +okay but also our cognitive level +uh we contain a model of the world and + + align:start position:0% +uh we contain a model of the world and + + + align:start position:0% +uh we contain a model of the world and +in that we make we embod choices we make + + align:start position:0% +in that we make we embod choices we make + + + align:start position:0% +in that we make we embod choices we make +and so + + align:start position:0% +and so + + + align:start position:0% +and so +[Music] + + align:start position:0% + + + + align:start position:0% + +forth I just point out here that the + + align:start position:0% +forth I just point out here that the + + + align:start position:0% +forth I just point out here that the +cognitive level is at the + + align:start position:0% +cognitive level is at the + + + align:start position:0% +cognitive level is at the +top of a neural hierarchy but it doesn't + + align:start position:0% +top of a neural hierarchy but it doesn't + + + align:start position:0% +top of a neural hierarchy but it doesn't +mean just because it's at the top that + + align:start position:0% +mean just because it's at the top that + + + align:start position:0% +mean just because it's at the top that +it's always dominant and we all know + + align:start position:0% +it's always dominant and we all know + + + align:start position:0% +it's always dominant and we all know +that for sure people can be totally + + align:start position:0% +that for sure people can be totally + + + align:start position:0% +that for sure people can be totally +dominated by + + align:start position:0% +dominated by + + + align:start position:0% +dominated by +see drive to enact + + align:start position:0% +see drive to enact + + + align:start position:0% +see drive to enact +Revenge uh drive to feed drive to + + align:start position:0% +Revenge uh drive to feed drive to + + + align:start position:0% +Revenge uh drive to feed drive to +acquire things these are innate behavior + + align:start position:0% +acquire things these are innate behavior + + + align:start position:0% +acquire things these are innate behavior +patterns and + + align:start position:0% +patterns and + + + align:start position:0% +patterns and +uh that cognitive level is often not at + + align:start position:0% +uh that cognitive level is often not at + + + align:start position:0% +uh that cognitive level is often not at +the + + align:start position:0% +the + + + align:start position:0% +the +top maybe in true + + align:start position:0% +top maybe in true + + + align:start position:0% +top maybe in true +intellectuals it + + align:start position:0% +intellectuals it + + + align:start position:0% +intellectuals it +is I Define a true intellectual as + + align:start position:0% +is I Define a true intellectual as + + + align:start position:0% +is I Define a true intellectual as +somebody who by what he knows and what + + align:start position:0% +somebody who by what he knows and what + + + align:start position:0% +somebody who by what he knows and what +he + + align:start position:0% +he + + + align:start position:0% +he +learns the cognitions that he acquires + + align:start position:0% +learns the cognitions that he acquires + + + align:start position:0% +learns the cognitions that he acquires +actually affect his behavior in a major + + align:start position:0% +actually affect his behavior in a major + + + align:start position:0% +actually affect his behavior in a major +way it's not true most + + align:start position:0% +way it's not true most + + + align:start position:0% +way it's not true most +people in fact when the one student uh + + align:start position:0% +people in fact when the one student uh + + + align:start position:0% +people in fact when the one student uh +working with Bruce and with me here at + + align:start position:0% +working with Bruce and with me here at + + + align:start position:0% +working with Bruce and with me here at +MIT was simulating human + + align:start position:0% +MIT was simulating human + + + align:start position:0% +MIT was simulating human +behavior everything in it except for + + align:start position:0% +behavior everything in it except for + + + align:start position:0% +behavior everything in it except for +some very simple spatial things was not + + align:start position:0% +some very simple spatial things was not + + + align:start position:0% +some very simple spatial things was not +learned it was all built into the + + align:start position:0% +learned it was all built into the + + + align:start position:0% +learned it was all built into the +software and yet you show the the + + align:start position:0% +software and yet you show the the + + + align:start position:0% +software and yet you show the the +results of simulations where you see + + align:start position:0% +results of simulations where you see + + + align:start position:0% +results of simulations where you see +people moving around making choices and + + align:start position:0% +people moving around making choices and + + + align:start position:0% +people moving around making choices and +this and that it looks like pretty + + align:start position:0% +this and that it looks like pretty + + + align:start position:0% +this and that it looks like pretty +normal human + + align:start position:0% +normal human + + + align:start position:0% +normal human +behavior so a lot of times when we're + + align:start position:0% +behavior so a lot of times when we're + + + align:start position:0% +behavior so a lot of times when we're +observing human behavior we're just + + align:start position:0% +observing human behavior we're just + + + align:start position:0% +observing human behavior we're just +looking at fixed action + + align:start position:0% + + + + align:start position:0% + +patterns all right + + align:start position:0% +patterns all right + + + align:start position:0% +patterns all right +uh next topic here is concerns what we + + align:start position:0% +uh next topic here is concerns what we + + + align:start position:0% +uh next topic here is concerns what we +call taxes and reflexes this involves + + align:start position:0% +call taxes and reflexes this involves + + + align:start position:0% +call taxes and reflexes this involves +spatial + + align:start position:0% +spatial + + + align:start position:0% +spatial +orientation and that leads to a + + align:start position:0% +orientation and that leads to a + + + align:start position:0% +orientation and that leads to a +discussion of thinking in higher + + align:start position:0% +discussion of thinking in higher + + + align:start position:0% +discussion of thinking in higher +animals uh first of all and we won't + + align:start position:0% +animals uh first of all and we won't + + + align:start position:0% +animals uh first of all and we won't +have time for too much more than this uh + + align:start position:0% +have time for too much more than this uh + + + align:start position:0% +have time for too much more than this uh +explain how the mantle of reflexes the + + align:start position:0% +explain how the mantle of reflexes the + + + align:start position:0% +explain how the mantle of reflexes the +term I've used from from phone + + align:start position:0% +term I've used from from phone + + + align:start position:0% +term I've used from from phone +Holst uh and Lawrence uses it I + + align:start position:0% +Holst uh and Lawrence uses it I + + + align:start position:0% +Holst uh and Lawrence uses it I +believe it tends to conceal the rigidity + + align:start position:0% +believe it tends to conceal the rigidity + + + align:start position:0% +believe it tends to conceal the rigidity +of fixed motor patterns + + align:start position:0% +of fixed motor patterns + + + align:start position:0% +of fixed motor patterns +you know when we walk for example we + + align:start position:0% +you know when we walk for example we + + + align:start position:0% +you know when we walk for example we +know that's a fixed motor pattern it + + align:start position:0% +know that's a fixed motor pattern it + + + align:start position:0% +know that's a fixed motor pattern it +appears at a certain age when the neural + + align:start position:0% +appears at a certain age when the neural + + + align:start position:0% +appears at a certain age when the neural +mechanisms of the spinal cord mature and + + align:start position:0% +mechanisms of the spinal cord mature and + + + align:start position:0% +mechanisms of the spinal cord mature and +the various gates are walking and + + align:start position:0% +the various gates are walking and + + + align:start position:0% +the various gates are walking and +running the various Gates of a horse + + align:start position:0% +running the various Gates of a horse + + + align:start position:0% +running the various Gates of a horse +which are multiple they're all + + align:start position:0% +which are multiple they're all + + + align:start position:0% +which are multiple they're all +inherited and yet at least especially + + align:start position:0% +inherited and yet at least especially + + + align:start position:0% +inherited and yet at least especially +for humans when we're walking around it + + align:start position:0% +for humans when we're walking around it + + + align:start position:0% +for humans when we're walking around it +seems to vary a lot it depends on what + + align:start position:0% +seems to vary a lot it depends on what + + + align:start position:0% +seems to vary a lot it depends on what +we're walking on it depends on the + + align:start position:0% +we're walking on it depends on the + + + align:start position:0% +we're walking on it depends on the +terrain even horses change the way they + + align:start position:0% +terrain even horses change the way they + + + align:start position:0% +terrain even horses change the way they +walk even though much less than say the + + align:start position:0% +walk even though much less than say the + + + align:start position:0% +walk even though much less than say the +more sure-footed animals like goats and + + align:start position:0% +more sure-footed animals like goats and + + + align:start position:0% +more sure-footed animals like goats and +donkeys but it's being adjusted by the + + align:start position:0% +donkeys but it's being adjusted by the + + + align:start position:0% +donkeys but it's being adjusted by the +reflexes you know if I'm walking along + + align:start position:0% +reflexes you know if I'm walking along + + + align:start position:0% +reflexes you know if I'm walking along +here I'm responding visually here too + + align:start position:0% +here I'm responding visually here too + + + align:start position:0% +here I'm responding visually here too +and I don't even look here but I can see + + align:start position:0% +and I don't even look here but I can see + + + align:start position:0% +and I don't even look here but I can see +the edge of this table and I will walk + + align:start position:0% +the edge of this table and I will walk + + + align:start position:0% +the edge of this table and I will walk +around it without even thinking about it + + align:start position:0% +around it without even thinking about it + + + align:start position:0% +around it without even thinking about it +this is just an example of simple + + align:start position:0% +this is just an example of simple + + + align:start position:0% +this is just an example of simple +spatial + + align:start position:0% +spatial + + + align:start position:0% +spatial +orientation uh reflexes that alter the + + align:start position:0% +orientation uh reflexes that alter the + + + align:start position:0% +orientation uh reflexes that alter the +way The Locomotion is expressed and + + align:start position:0% +way The Locomotion is expressed and + + + align:start position:0% +way The Locomotion is expressed and +there's much simpler examples uh like + + align:start position:0% +there's much simpler examples uh like + + + align:start position:0% +there's much simpler examples uh like +the egg rolling behavior of the grey leg + + align:start position:0% +the egg rolling behavior of the grey leg + + + align:start position:0% +the egg rolling behavior of the grey leg +Goose every time you see a grey leg + + align:start position:0% +Goose every time you see a grey leg + + + align:start position:0% +Goose every time you see a grey leg +Goose rolling a leg an egg back into the + + align:start position:0% +Goose rolling a leg an egg back into the + + + align:start position:0% +Goose rolling a leg an egg back into the +nest it looks a little different than + + align:start position:0% +nest it looks a little different than + + + align:start position:0% +nest it looks a little different than +other times you see it because the egg + + align:start position:0% +other times you see it because the egg + + + align:start position:0% +other times you see it because the egg +is rolling this way and that it's + + align:start position:0% +is rolling this way and that it's + + + align:start position:0% +is rolling this way and that it's +meeting little stones and he has to keep + + align:start position:0% +meeting little stones and he has to keep + + + align:start position:0% +meeting little stones and he has to keep +adjusting how + + align:start position:0% +adjusting how + + + align:start position:0% +adjusting how +he's getting his beak over the egg and + + align:start position:0% +he's getting his beak over the egg and + + + align:start position:0% +he's getting his beak over the egg and +pulling it back towards the nest so it + + align:start position:0% +pulling it back towards the nest so it + + + align:start position:0% +pulling it back towards the nest so it +looks like it's complex and yet it's a + + align:start position:0% +looks like it's complex and yet it's a + + + align:start position:0% +looks like it's complex and yet it's a +fixed motor pattern it's basically the + + align:start position:0% +fixed motor pattern it's basically the + + + align:start position:0% +fixed motor pattern it's basically the +same motor pattern but it's working at a + + align:start position:0% +same motor pattern but it's working at a + + + align:start position:0% +same motor pattern but it's working at a +higher level than all these reflexes + + align:start position:0% +higher level than all these reflexes + + + align:start position:0% +higher level than all these reflexes +that are constantly adjusting it and the + + align:start position:0% +that are constantly adjusting it and the + + + align:start position:0% +that are constantly adjusting it and the +reflexes never stop remember they don't + + align:start position:0% +reflexes never stop remember they don't + + + align:start position:0% +reflexes never stop remember they don't +depend on the + + align:start position:0% +depend on the + + + align:start position:0% +depend on the +motivation they always + + align:start position:0% +motivation they always + + + align:start position:0% +motivation they always +act so it looks variable and complex + + align:start position:0% +act so it looks variable and complex + + + align:start position:0% +act so it looks variable and complex +because it's + + align:start position:0% +because it's + + + align:start position:0% +because it's +superimposed um superimposed on the + + align:start position:0% +superimposed um superimposed on the + + + align:start position:0% +superimposed um superimposed on the +behavior are these various reflexes + + align:start position:0% +behavior are these various reflexes + + + align:start position:0% +behavior are these various reflexes +they're vestibular they're tactile + + align:start position:0% +they're vestibular they're tactile + + + align:start position:0% +they're vestibular they're tactile +they're + + align:start position:0% +they're + + + align:start position:0% +they're +visual uh and so + + align:start position:0% + + + + align:start position:0% + +forth last topic a + + align:start position:0% +forth last topic a + + + align:start position:0% +forth last topic a +goldfish behind a barrier let's say + + align:start position:0% +goldfish behind a barrier let's say + + + align:start position:0% +goldfish behind a barrier let's say +these are thick weeds he can't swim + + align:start position:0% +these are thick weeds he can't swim + + + align:start position:0% +these are thick weeds he can't swim +through but he can see through it well + + align:start position:0% +through but he can see through it well + + + align:start position:0% +through but he can see through it well +enough to see that there's food on the + + align:start position:0% +enough to see that there's food on the + + + align:start position:0% +enough to see that there's food on the +other side + + align:start position:0% + + + + align:start position:0% + +how does he solve that problem and + + align:start position:0% +how does he solve that problem and + + + align:start position:0% +how does he solve that problem and +actually goldfish show pretty well + + align:start position:0% +actually goldfish show pretty well + + + align:start position:0% +actually goldfish show pretty well +better than dogs + + align:start position:0% +better than dogs + + + align:start position:0% +better than dogs +actually here's what he does he swims + + align:start position:0% +actually here's what he does he swims + + + align:start position:0% +actually here's what he does he swims +right for + + align:start position:0% +right for + + + align:start position:0% +right for +it and as soon as he touches it he's got + + align:start position:0% +it and as soon as he touches it he's got + + + align:start position:0% +it and as soon as he touches it he's got +another reflex okay we call it a + + align:start position:0% +another reflex okay we call it a + + + align:start position:0% +another reflex okay we call it a +negative figmo taxis a negative response + + align:start position:0% +negative figmo taxis a negative response + + + align:start position:0% +negative figmo taxis a negative response +to touching with his snout and that + + align:start position:0% +to touching with his snout and that + + + align:start position:0% +to touching with his snout and that +causes him to pull back now of course + + align:start position:0% +causes him to pull back now of course + + + align:start position:0% +causes him to pull back now of course +the algorithm can vary among fish and + + align:start position:0% +the algorithm can vary among fish and + + + align:start position:0% +the algorithm can vary among fish and +it's very different in dogs but normally + + align:start position:0% +it's very different in dogs but normally + + + align:start position:0% +it's very different in dogs but normally +he will keep trying to get at the food + + align:start position:0% +he will keep trying to get at the food + + + align:start position:0% +he will keep trying to get at the food +but he will keep moving like this until + + align:start position:0% +but he will keep moving like this until + + + align:start position:0% +but he will keep moving like this until +he can get it the + + align:start position:0% +he can get it the + + + align:start position:0% +he can get it the +food so just two reflexes are enough + + align:start position:0% +food so just two reflexes are enough + + + align:start position:0% +food so just two reflexes are enough +positive tilot taxis is what we call his + + align:start position:0% +positive tilot taxis is what we call his + + + align:start position:0% +positive tilot taxis is what we call his +moving towards the food there just a + + align:start position:0% +moving towards the food there just a + + + align:start position:0% +moving towards the food there just a +technical name for it positive tilo + + align:start position:0% +technical name for it positive tilo + + + align:start position:0% +technical name for it positive tilo +taxis tilo means the end taxis movement + + align:start position:0% +taxis tilo means the end taxis movement + + + align:start position:0% +taxis tilo means the end taxis movement +okay directed towards the towards the + + align:start position:0% +okay directed towards the towards the + + + align:start position:0% +okay directed towards the towards the +prey or towards other food that he was + + align:start position:0% +prey or towards other food that he was + + + align:start position:0% +prey or towards other food that he was +trying to get to and then the negative + + align:start position:0% +trying to get to and then the negative + + + align:start position:0% +trying to get to and then the negative +thigo + + align:start position:0% +thigo + + + align:start position:0% +thigo +thigmotaxis causes him to avoid the + + align:start position:0% +thigmotaxis causes him to avoid the + + + align:start position:0% +thigmotaxis causes him to avoid the +obstacles branches plants so forth so it + + align:start position:0% +obstacles branches plants so forth so it + + + align:start position:0% +obstacles branches plants so forth so it +looks like intelligent + + align:start position:0% + + + + align:start position:0% + +Behavior he seems to figure out how to + + align:start position:0% +Behavior he seems to figure out how to + + + align:start position:0% +Behavior he seems to figure out how to +reach the food but in fact it's just two + + align:start position:0% +reach the food but in fact it's just two + + + align:start position:0% +reach the food but in fact it's just two +reflexes running off okay so now think + + align:start position:0% +reflexes running off okay so now think + + + align:start position:0% +reflexes running off okay so now think +about how a dog does it and we'll come + + align:start position:0% +about how a dog does it and we'll come + + + align:start position:0% +about how a dog does it and we'll come +back here next time \ No newline at end of file diff --git a/Ke2CpF8M0mc.txt b/Ke2CpF8M0mc.txt new file mode 100644 index 0000000000000000000000000000000000000000..acb3394686543a2e4c937a661a9cda6c0b9c3f84 --- /dev/null +++ b/Ke2CpF8M0mc.txt @@ -0,0 +1,79 @@ +Hello. This is Cheryl Siegel from MIT OpenCourseWare. +Today I'm going to show you the Chandra Astrophysics + +Institute course on Highlights for High School. +This section of OCW is for high school students, + +teachers, and parents who want to learn about +math, science, engineering, and technology. + +You can find this course under High School +Courses Developed by MIT. I chose Chandra + +Astrophysics, because it is a unique resource +for high school teachers and their students. + +Astrophysics isn't usually taught at the +high school level, but this course makes the + +subject easy and interesting for anyone that +wants to learn about this branch of astronomy. + +This course also offers models and instructions +to replicate many hands-on activities and + +includes dozens of hours of video. +Chandra Astrophysics Institute is an MIT program + +for students in grades 9 through 11. Students +tackle astrophysics projects, are mentored + +by MIT scientists, and use images from the +Chandra X-Ray space telescope. The sessions + +weÕve published here were taught by Mark +Hartman in the summer of 2008. + +As you can see, the course is divided into +six investigations, each focusing on a specific + +area of astrophysics. Each investigation builds +on the knowledge from the previous one. + +The investigations are organized around a +series of activities. + +Activity 2 in Investigation 1 taught students +about the size of objects in images and how + +to make observations about angular size. +Here, students can see examples of trick photography... + +...and even a video of Kobe Bryant demonstrating +the concept by appearing to jump over a car. + +There are detailed instructions for teachers, +including notes, tips and tricks, as well + +as ideas for assessment. +Also you will see several embedded videos, + +which correspond to the investigation and +activity. This is a great way to get a glimpse + +of what it was like to be in this class. +The image gallery shows dozens of photographs + +taken during the course. +Here a student demonstrates his attempt at + +creating his own trick photograph. +You can explore more high school resources + +at ocw.mit.edu/highschool +You can also subscribe to our newsletter to + +get email updates from OCW. +Finally, you can help support OCW by making + +a donation at ocw.mit.edu/donate \ No newline at end of file diff --git a/KhT9m9kFzv8.txt b/KhT9m9kFzv8.txt new file mode 100644 index 0000000000000000000000000000000000000000..22afb394ff36f9c0184d6333e1b394aecd185472 --- /dev/null +++ b/KhT9m9kFzv8.txt @@ -0,0 +1,7619 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +I think I might actually use all 16 + + align:start position:0% +I think I might actually use all 16 + + + align:start position:0% +I think I might actually use all 16 +colors today oh no this is the most + + align:start position:0% +colors today oh no this is the most + + + align:start position:0% +colors today oh no this is the most +satisfying day whereas Tuesday was + + align:start position:0% +satisfying day whereas Tuesday was + + + align:start position:0% +satisfying day whereas Tuesday was +probably the most mathematically intense + + align:start position:0% +probably the most mathematically intense + + + align:start position:0% +probably the most mathematically intense +because we developed this equation right + + align:start position:0% +because we developed this equation right + + + align:start position:0% +because we developed this equation right +here today is gonna be the most + + align:start position:0% +here today is gonna be the most + + + align:start position:0% +here today is gonna be the most +satisfying because we are going to + + align:start position:0% +satisfying because we are going to + + + align:start position:0% +satisfying because we are going to +cancel out just about every term leaving + + align:start position:0% +cancel out just about every term leaving + + + align:start position:0% +cancel out just about every term leaving +a homogeneous infinite reactor + + align:start position:0% +a homogeneous infinite reactor + + + align:start position:0% +a homogeneous infinite reactor +criticality condition so we will go over + + align:start position:0% +criticality condition so we will go over + + + align:start position:0% +criticality condition so we will go over +today how do you go from this to what is + + align:start position:0% +today how do you go from this to what is + + + align:start position:0% +today how do you go from this to what is +criticality in a reactor so I want to + + align:start position:0% +criticality in a reactor so I want to + + + align:start position:0% +criticality in a reactor so I want to +get a couple of variables up over here + + align:start position:0% +get a couple of variables up over here + + + align:start position:0% +get a couple of variables up over here +to remind you guys we had this variable + + align:start position:0% +to remind you guys we had this variable + + + align:start position:0% +to remind you guys we had this variable +flux of our I Omega T in the number of + + align:start position:0% +flux of our I Omega T in the number of + + + align:start position:0% +flux of our I Omega T in the number of +neutrons per centimeter squared per + + align:start position:0% +neutrons per centimeter squared per + + + align:start position:0% +neutrons per centimeter squared per +second travelling through something and + + align:start position:0% +second travelling through something and + + + align:start position:0% +second travelling through something and +we also had its corresponding non + + align:start position:0% +we also had its corresponding non + + + align:start position:0% +we also had its corresponding non +angular dependent term on just R et if + + align:start position:0% +angular dependent term on just R et if + + + align:start position:0% +angular dependent term on just R et if +we don't care what angle things go + + align:start position:0% +we don't care what angle things go + + + align:start position:0% +we don't care what angle things go +through we've got a corresponding + + align:start position:0% +through we've got a corresponding + + + align:start position:0% +through we've got a corresponding +variable called current so I'll put this + + align:start position:0% +variable called current so I'll put this + + + align:start position:0% +variable called current so I'll put this +as flux we have current J R Omega T and + + align:start position:0% +as flux we have current J R Omega T and + + + align:start position:0% +as flux we have current J R Omega T and +it's corresponding we don't care about + + align:start position:0% +it's corresponding we don't care about + + + align:start position:0% +it's corresponding we don't care about +angle form and today what we're gonna do + + align:start position:0% +angle form and today what we're gonna do + + + align:start position:0% +angle form and today what we're gonna do +is first go over this equation again so + + align:start position:0% +is first go over this equation again so + + + align:start position:0% +is first go over this equation again so +that we understand all of its parts and + + align:start position:0% +that we understand all of its parts and + + + align:start position:0% +that we understand all of its parts and +there are more parts here than are in + + align:start position:0% +there are more parts here than are in + + + align:start position:0% +there are more parts here than are in +the reading if you remember that's + + align:start position:0% +the reading if you remember that's + + + align:start position:0% +the reading if you remember that's +because I wanted to show you how all of + + align:start position:0% +because I wanted to show you how all of + + + align:start position:0% +because I wanted to show you how all of +these terms are created just about every + + align:start position:0% +these terms are created just about every + + + align:start position:0% +these terms are created just about every +one of these terms except the external + + align:start position:0% +one of these terms except the external + + + align:start position:0% +one of these terms except the external +source and the flow through some surface + + align:start position:0% +source and the flow through some surface + + + align:start position:0% +source and the flow through some surface +has the form of some multiplier times + + align:start position:0% +has the form of some multiplier times + + + align:start position:0% +has the form of some multiplier times +the integral over all possible variables + + align:start position:0% +the integral over all possible variables + + + align:start position:0% +the integral over all possible variables +that we care about times a reaction rate + + align:start position:0% +that we care about times a reaction rate + + + align:start position:0% +that we care about times a reaction rate +D stuff where this reaction rate is + + align:start position:0% +D stuff where this reaction rate is + + + align:start position:0% +D stuff where this reaction rate is +always going to be some cross-section + + align:start position:0% +always going to be some cross-section + + + align:start position:0% +always going to be some cross-section +times some flux so when you look at this + + align:start position:0% +times some flux so when you look at this + + + align:start position:0% +times some flux so when you look at this +equation using that template it's + + align:start position:0% +equation using that template it's + + + align:start position:0% +equation using that template it's +actually not so bad so let's go through + + align:start position:0% +actually not so bad so let's go through + + + align:start position:0% +actually not so bad so let's go through +each of these pieces right here and then + + align:start position:0% +each of these pieces right here and then + + + align:start position:0% +each of these pieces right here and then +we're going to start simplifying things + + align:start position:0% +we're going to start simplifying things + + + align:start position:0% +we're going to start simplifying things +and this boards going to look like + + align:start position:0% +and this boards going to look like + + + align:start position:0% +and this boards going to look like +something + + align:start position:0% +something + + + align:start position:0% +something +rainbow explosion but all that's gonna + + align:start position:0% +rainbow explosion but all that's gonna + + + align:start position:0% +rainbow explosion but all that's gonna +be left is a much simpler form of the + + align:start position:0% +be left is a much simpler form of the + + + align:start position:0% +be left is a much simpler form of the +neutron diffusion equation so we've got + + align:start position:0% +neutron diffusion equation so we've got + + + align:start position:0% +neutron diffusion equation so we've got +our time dependent term right here where + + align:start position:0% +our time dependent term right here where + + + align:start position:0% +our time dependent term right here where +I've stuck in this variable flux instead + + align:start position:0% +I've stuck in this variable flux instead + + + align:start position:0% +I've stuck in this variable flux instead +of the number of neutrons n because we + + align:start position:0% +of the number of neutrons n because we + + + align:start position:0% +of the number of neutrons n because we +know that flux is the number of neutrons + + align:start position:0% +know that flux is the number of neutrons + + + align:start position:0% +know that flux is the number of neutrons +times the speed V at which they're + + align:start position:0% +times the speed V at which they're + + + align:start position:0% +times the speed V at which they're +moving and just to check our units flux + + align:start position:0% +moving and just to check our units flux + + + align:start position:0% +moving and just to check our units flux +should be in neutrons per centimeter + + align:start position:0% +should be in neutrons per centimeter + + + align:start position:0% +should be in neutrons per centimeter +squared per second and n is in neutrons + + align:start position:0% +squared per second and n is in neutrons + + + align:start position:0% +squared per second and n is in neutrons +per cubic centimeter and velocity is in + + align:start position:0% +per cubic centimeter and velocity is in + + + align:start position:0% +per cubic centimeter and velocity is in +centimeters per second so the unit's + + align:start position:0% +centimeters per second so the unit's + + + align:start position:0% +centimeters per second so the unit's +check out that's why I made that + + align:start position:0% +check out that's why I made that + + + align:start position:0% +check out that's why I made that +substitution right there and this way + + align:start position:0% +substitution right there and this way + + + align:start position:0% +substitution right there and this way +everything is in terms of little Phi the + + align:start position:0% +everything is in terms of little Phi the + + + align:start position:0% +everything is in terms of little Phi the +flux we have our first term here I think + + align:start position:0% +flux we have our first term here I think + + + align:start position:0% +flux we have our first term here I think +I'll have a labeling color that'll make + + align:start position:0% +I'll have a labeling color that'll make + + + align:start position:0% +I'll have a labeling color that'll make +things a little easier to understand + + align:start position:0% +things a little easier to understand + + + align:start position:0% +things a little easier to understand +which is due to a regular old fission in + + align:start position:0% +which is due to a regular old fission in + + + align:start position:0% +which is due to a regular old fission in +this case we have knew the number of + + align:start position:0% +this case we have knew the number of + + + align:start position:0% +this case we have knew the number of +neutrons created per fission times Chi + + align:start position:0% +neutrons created per fission times Chi + + + align:start position:0% +neutrons created per fission times Chi +the sort of the fission births spectrum + + align:start position:0% +the sort of the fission births spectrum + + + align:start position:0% +the sort of the fission births spectrum +or at what energy the neutrons are born + + align:start position:0% +or at what energy the neutrons are born + + + align:start position:0% +or at what energy the neutrons are born +over 4pi to account for all different + + align:start position:0% +over 4pi to account for all different + + + align:start position:0% +over 4pi to account for all different +angles in which they could go out times + + align:start position:0% +angles in which they could go out times + + + align:start position:0% +angles in which they could go out times +the integral over our whole control + + align:start position:0% +the integral over our whole control + + + align:start position:0% +the integral over our whole control +volume and all other energies and angles + + align:start position:0% +volume and all other energies and angles + + + align:start position:0% +volume and all other energies and angles +if you remember now we're trying to + + align:start position:0% +if you remember now we're trying to + + + align:start position:0% +if you remember now we're trying to +track the number of neutrons in some + + align:start position:0% +track the number of neutrons in some + + + align:start position:0% +track the number of neutrons in some +small Energy Group e traveling in some + + align:start position:0% +small Energy Group e traveling in some + + + align:start position:0% +small Energy Group e traveling in some +small direction Omega and those have + + align:start position:0% +small direction Omega and those have + + + align:start position:0% +small direction Omega and those have +little vector things on it at some + + align:start position:0% +little vector things on it at some + + + align:start position:0% +little vector things on it at some +specific position as a function of time + + align:start position:0% +specific position as a function of time + + + align:start position:0% +specific position as a function of time +so in order to figure out how many + + align:start position:0% +so in order to figure out how many + + + align:start position:0% +so in order to figure out how many +neutrons are entering our group from + + align:start position:0% +neutrons are entering our group from + + + align:start position:0% +neutrons are entering our group from +fission we need to know what are all + + align:start position:0% +fission we need to know what are all + + + align:start position:0% +fission we need to know what are all +divisions happening in all the other + + align:start position:0% +divisions happening in all the other + + + align:start position:0% +divisions happening in all the other +groups + + align:start position:0% +groups + + + align:start position:0% +groups +I've also escalated this problem a + + align:start position:0% +I've also escalated this problem a + + + align:start position:0% +I've also escalated this problem a +little bit to not assume that the + + align:start position:0% +little bit to not assume that the + + + align:start position:0% +little bit to not assume that the +reactors homogeneous so I've added an R + + align:start position:0% +reactors homogeneous so I've added an R + + + align:start position:0% +reactors homogeneous so I've added an R +or a spatial dependence for every cross + + align:start position:0% +or a spatial dependence for every cross + + + align:start position:0% +or a spatial dependence for every cross +section here which means that as you + + align:start position:0% +section here which means that as you + + + align:start position:0% +section here which means that as you +move through the reactor you might + + align:start position:0% +move through the reactor you might + + + align:start position:0% +move through the reactor you might +encounter different materials you almost + + align:start position:0% +encounter different materials you almost + + + align:start position:0% +encounter different materials you almost +certainly will unless your reactors been + + align:start position:0% +certainly will unless your reactors been + + + align:start position:0% +certainly will unless your reactors been +in a blender so it except for that case + + align:start position:0% +in a blender so it except for that case + + + align:start position:0% +in a blender so it except for that case +you would actually have different cross + + align:start position:0% +you would actually have different cross + + + align:start position:0% +you would actually have different cross +sections in different parts of the + + align:start position:0% +sections in different parts of the + + + align:start position:0% +sections in different parts of the +reactor so all of a sudden this is + + align:start position:0% +reactor so all of a sudden this is + + + align:start position:0% +reactor so all of a sudden this is +starting to get awfully interesting or + + align:start position:0% +starting to get awfully interesting or + + + align:start position:0% +starting to get awfully interesting or +messy depending on what + + align:start position:0% +messy depending on what + + + align:start position:0% +messy depending on what +want to think about it there's the + + align:start position:0% +want to think about it there's the + + + align:start position:0% +want to think about it there's the +external source which is actually a real + + align:start position:0% +external source which is actually a real + + + align:start position:0% +external source which is actually a real +phenomenon because reactors do stick in + + align:start position:0% +phenomenon because reactors do stick in + + + align:start position:0% +phenomenon because reactors do stick in +those californium kickstarter sources so + + align:start position:0% +those californium kickstarter sources so + + + align:start position:0% +those californium kickstarter sources so +for some amount of time there is an + + align:start position:0% +for some amount of time there is an + + + align:start position:0% +for some amount of time there is an +external source of neutrons giving them + + align:start position:0% +external source of neutrons giving them + + + align:start position:0% +external source of neutrons giving them +out with some positional energy angle + + align:start position:0% +out with some positional energy angle + + + align:start position:0% +out with some positional energy angle +and time dependence so let's call this + + align:start position:0% +and time dependence so let's call this + + + align:start position:0% +and time dependence so let's call this +the Kickstarter source there's this term + + align:start position:0% +the Kickstarter source there's this term + + + align:start position:0% +the Kickstarter source there's this term +right here the n i n reactions so these + + align:start position:0% +right here the n i n reactions so these + + + align:start position:0% +right here the n i n reactions so these +are other reactions where it's absorb a + + align:start position:0% +are other reactions where it's absorb a + + + align:start position:0% +are other reactions where it's absorb a +neutron and give off anywhere between 2 + + align:start position:0% +neutron and give off anywhere between 2 + + + align:start position:0% +neutron and give off anywhere between 2 +& 4 neutrons beyond that there it's just + + align:start position:0% +& 4 neutrons beyond that there it's just + + + align:start position:0% +& 4 neutrons beyond that there it's just +not energetically possible in a fission + + align:start position:0% +not energetically possible in a fission + + + align:start position:0% +not energetically possible in a fission +reactor but don't undergo fission they + + align:start position:0% +reactor but don't undergo fission they + + + align:start position:0% +reactor but don't undergo fission they +have their own cross-sections their own + + align:start position:0% +have their own cross-sections their own + + + align:start position:0% +have their own cross-sections their own +birth spectrum and I've stuck in + + align:start position:0% +birth spectrum and I've stuck in + + + align:start position:0% +birth spectrum and I've stuck in +something right here if we're summing + + align:start position:0% +something right here if we're summing + + + align:start position:0% +something right here if we're summing +over all possible I where you have this + + align:start position:0% +over all possible I where you have this + + + align:start position:0% +over all possible I where you have this +reaction D and I an reaction where one + + align:start position:0% +reaction D and I an reaction where one + + + align:start position:0% +reaction D and I an reaction where one +Neutron goes in and I neutrons come out + + align:start position:0% +Neutron goes in and I neutrons come out + + + align:start position:0% +Neutron goes in and I neutrons come out +you've got to multiply by the number of + + align:start position:0% +you've got to multiply by the number of + + + align:start position:0% +you've got to multiply by the number of +neutrons per reaction for fission that + + align:start position:0% +neutrons per reaction for fission that + + + align:start position:0% +neutrons per reaction for fission that +was new for an ni n reaction that's just + + align:start position:0% +was new for an ni n reaction that's just + + + align:start position:0% +was new for an ni n reaction that's just +AI but otherwise the term looks the same + + align:start position:0% +AI but otherwise the term looks the same + + + align:start position:0% +AI but otherwise the term looks the same +you have your multiplier your birth + + align:start position:0% +you have your multiplier your birth + + + align:start position:0% +you have your multiplier your birth +spectrum your 4pi your integral over + + align:start position:0% +spectrum your 4pi your integral over + + + align:start position:0% +spectrum your 4pi your integral over +stuff your unique cross-section and the + + align:start position:0% +stuff your unique cross-section and the + + + align:start position:0% +stuff your unique cross-section and the +flux and these two together give you a + + align:start position:0% +flux and these two together give you a + + + align:start position:0% +flux and these two together give you a +reaction rate I've just written all of + + align:start position:0% +reaction rate I've just written all of + + + align:start position:0% +reaction rate I've just written all of +the differentials as D stuff because it + + align:start position:0% +the differentials as D stuff because it + + + align:start position:0% +the differentials as D stuff because it +takes a lot of time to write those over + + align:start position:0% +takes a lot of time to write those over + + + align:start position:0% +takes a lot of time to write those over +and over again and then we have our + + align:start position:0% +and over again and then we have our + + + align:start position:0% +and over again and then we have our +photo fission term where gamma rays of + + align:start position:0% +photo fission term where gamma rays of + + + align:start position:0% +photo fission term where gamma rays of +sufficiently high energy can also induce + + align:start position:0% +sufficiently high energy can also induce + + + align:start position:0% +sufficiently high energy can also induce +fission external to the neutrons the + + align:start position:0% +fission external to the neutrons the + + + align:start position:0% +fission external to the neutrons the +term looks exactly the same there's + + align:start position:0% +term looks exactly the same there's + + + align:start position:0% +term looks exactly the same there's +going to be some new for photo fission + + align:start position:0% +going to be some new for photo fission + + + align:start position:0% +going to be some new for photo fission +some birth spectrum for photo fission + + align:start position:0% +some birth spectrum for photo fission + + + align:start position:0% +some birth spectrum for photo fission +some cross-section for photo fission and + + align:start position:0% +some cross-section for photo fission and + + + align:start position:0% +some cross-section for photo fission and +the same flux that we're using + + align:start position:0% +the same flux that we're using + + + align:start position:0% +the same flux that we're using +everywhere else then we had what's + + align:start position:0% +everywhere else then we had what's + + + align:start position:0% +everywhere else then we had what's +called the in scattering term where + + align:start position:0% +called the in scattering term where + + + align:start position:0% +called the in scattering term where +neutrons can undergo scattering lose + + align:start position:0% +neutrons can undergo scattering lose + + + align:start position:0% +neutrons can undergo scattering lose +some energy and enter our group from + + align:start position:0% +some energy and enter our group from + + + align:start position:0% +some energy and enter our group from +somewhere else + + align:start position:0% +somewhere else + + + align:start position:0% +somewhere else +that's why we have those Ian Omega + + align:start position:0% +that's why we have those Ian Omega + + + align:start position:0% +that's why we have those Ian Omega +Prime's because it's some other energy + + align:start position:0% +Prime's because it's some other energy + + + align:start position:0% +Prime's because it's some other energy +and we have to account for all of those + + align:start position:0% +and we have to account for all of those + + + align:start position:0% +and we have to account for all of those +energy groups that's why we have this + + align:start position:0% +energy groups that's why we have this + + + align:start position:0% +energy groups that's why we have this +integral there and it looks very much + + align:start position:0% +integral there and it looks very much + + + align:start position:0% +integral there and it looks very much +the same there's a scattering + + align:start position:0% +the same there's a scattering + + + align:start position:0% +the same there's a scattering +cross-section and those should actually + + align:start position:0% +cross-section and those should actually + + + align:start position:0% +cross-section and those should actually +be it should be an e Prime right there + + align:start position:0% +be it should be an e Prime right there + + + align:start position:0% +be it should be an e Prime right there +make sure I'm not missing any more of + + align:start position:0% +make sure I'm not missing any more of + + + align:start position:0% +make sure I'm not missing any more of +those inside the integral that's all + + align:start position:0% +those inside the integral that's all + + + align:start position:0% +those inside the integral that's all +good + + align:start position:0% +good + + + align:start position:0% +good +that's a prime good there's also a flux + + align:start position:0% +that's a prime good there's also a flux + + + align:start position:0% +that's a prime good there's also a flux +and then there was this probability + + align:start position:0% +and then there was this probability + + + align:start position:0% +and then there was this probability +function that a given Neutron starting + + align:start position:0% +function that a given Neutron starting + + + align:start position:0% +function that a given Neutron starting +off at energy E prime Omega prime ends + + align:start position:0% +off at energy E prime Omega prime ends + + + align:start position:0% +off at energy E prime Omega prime ends +up scattering into our energy in Omega + + align:start position:0% +up scattering into our energy in Omega + + + align:start position:0% +up scattering into our energy in Omega +so this would be the other one and this + + align:start position:0% +so this would be the other one and this + + + align:start position:0% +so this would be the other one and this +would be our group but otherwise the + + align:start position:0% +would be our group but otherwise the + + + align:start position:0% +would be our group but otherwise the +term looks very much the same and that + + align:start position:0% +term looks very much the same and that + + + align:start position:0% +term looks very much the same and that +takes care of all the possible gains of + + align:start position:0% +takes care of all the possible gains of + + + align:start position:0% +takes care of all the possible gains of +neutrons into our group the losses are a + + align:start position:0% +neutrons into our group the losses are a + + + align:start position:0% +neutrons into our group the losses are a +fair bit simpler there's reaction of + + align:start position:0% +fair bit simpler there's reaction of + + + align:start position:0% +fair bit simpler there's reaction of +absolutely any kind let's say this would + + align:start position:0% +absolutely any kind let's say this would + + + align:start position:0% +absolutely any kind let's say this would +be the total cross-section which says + + align:start position:0% +be the total cross-section which says + + + align:start position:0% +be the total cross-section which says +that if a neutron undergoes any reaction + + align:start position:0% +that if a neutron undergoes any reaction + + + align:start position:0% +that if a neutron undergoes any reaction +at all it's going to lose energy and go + + align:start position:0% +at all it's going to lose energy and go + + + align:start position:0% +at all it's going to lose energy and go +out of our energy group de notice here + + align:start position:0% +out of our energy group de notice here + + + align:start position:0% +out of our energy group de notice here +that these are all these energies and + + align:start position:0% +that these are all these energies and + + + align:start position:0% +that these are all these energies and +omegas are all our group because we only + + align:start position:0% +omegas are all our group because we only + + + align:start position:0% +omegas are all our group because we only +care about how many neutrons in our + + align:start position:0% +care about how many neutrons in our + + + align:start position:0% +care about how many neutrons in our +group undergo a reaction and leaf and + + align:start position:0% +group undergo a reaction and leaf and + + + align:start position:0% +group undergo a reaction and leaf and +the form is very simple integrate over + + align:start position:0% +the form is very simple integrate over + + + align:start position:0% +the form is very simple integrate over +volume energy in and Direction times a + + align:start position:0% +volume energy in and Direction times a + + + align:start position:0% +volume energy in and Direction times a +cross section times the flux just like + + align:start position:0% +cross section times the flux just like + + + align:start position:0% +cross section times the flux just like +all the other ones then the only + + align:start position:0% +all the other ones then the only + + + align:start position:0% +all the other ones then the only +difference and one right here is what + + align:start position:0% +difference and one right here is what + + + align:start position:0% +difference and one right here is what +we'll call leakage these are neutrons + + align:start position:0% +we'll call leakage these are neutrons + + + align:start position:0% +we'll call leakage these are neutrons +moving out of whatever control surface + + align:start position:0% +moving out of whatever control surface + + + align:start position:0% +moving out of whatever control surface +that we're looking at and this can be + + align:start position:0% +that we're looking at and this can be + + + align:start position:0% +that we're looking at and this can be +some arbitrarily complex control surface + + align:start position:0% +some arbitrarily complex control surface + + + align:start position:0% +some arbitrarily complex control surface +in 3d I don't really know how to draw a + + align:start position:0% +in 3d I don't really know how to draw a + + + align:start position:0% +in 3d I don't really know how to draw a +blob in 3d but at every point on that + + align:start position:0% +blob in 3d but at every point on that + + + align:start position:0% +blob in 3d but at every point on that +glob there's going to be a normal vector + + align:start position:0% +glob there's going to be a normal vector + + + align:start position:0% +glob there's going to be a normal vector +and you can then take the current of + + align:start position:0% +and you can then take the current of + + + align:start position:0% +and you can then take the current of +neutrons traveling out that normal + + align:start position:0% +neutrons traveling out that normal + + + align:start position:0% +neutrons traveling out that normal +vector and figure out how much of that + + align:start position:0% +vector and figure out how much of that + + + align:start position:0% +vector and figure out how much of that +is actually leaving our surface DS the + + align:start position:0% +is actually leaving our surface DS the + + + align:start position:0% +is actually leaving our surface DS the +one problem we had is that everything + + align:start position:0% +one problem we had is that everything + + + align:start position:0% +one problem we had is that everything +here is in terms of volume volume volume + + align:start position:0% +here is in terms of volume volume volume + + + align:start position:0% +here is in terms of volume volume volume +surface so we don't have all the same + + align:start position:0% +surface so we don't have all the same + + + align:start position:0% +surface so we don't have all the same +terms because once we have everything in + + align:start position:0% +terms because once we have everything in + + + align:start position:0% +terms because once we have everything in +the same variables we can start to make + + align:start position:0% +the same variables we can start to make + + + align:start position:0% +the same variables we can start to make +some pretty crazy simplifications the + + align:start position:0% +some pretty crazy simplifications the + + + align:start position:0% +some pretty crazy simplifications the +last thing we did is we invoked the + + align:start position:0% +last thing we did is we invoked the + + + align:start position:0% +last thing we did is we invoked the +divergence theorem that says that the + + align:start position:0% +divergence theorem that says that the + + + align:start position:0% +divergence theorem that says that the +surface integral of some variable f DS + + align:start position:0% +surface integral of some variable f DS + + + align:start position:0% +surface integral of some variable f DS +is the same as the volume integral of + + align:start position:0% +is the same as the volume integral of + + + align:start position:0% +is the same as the volume integral of +the divergence of that variable DV so I + + align:start position:0% +the divergence of that variable DV so I + + + align:start position:0% +the divergence of that variable DV so I +remember there was some snickering last + + align:start position:0% +remember there was some snickering last + + + align:start position:0% +remember there was some snickering last +time because you probably haven't seen + + align:start position:0% +time because you probably haven't seen + + + align:start position:0% +time because you probably haven't seen +this since was it 1801 or 1802 1802 okay + + align:start position:0% +this since was it 1801 or 1802 1802 okay + + + align:start position:0% +this since was it 1801 or 1802 1802 okay +that makes sense because divergence + + align:start position:0% +that makes sense because divergence + + + align:start position:0% +that makes sense because divergence +usually has more than one variable + + align:start position:0% +usually has more than one variable + + + align:start position:0% +usually has more than one variable +associated with it I'll include the dot + + align:start position:0% +associated with it I'll include the dot + + + align:start position:0% +associated with it I'll include the dot +because that's what makes it divergence + + align:start position:0% +because that's what makes it divergence + + + align:start position:0% +because that's what makes it divergence +so we can then rewrite this term let's + + align:start position:0% +so we can then rewrite this term let's + + + align:start position:0% +so we can then rewrite this term let's +start our simplification colors that's + + align:start position:0% +start our simplification colors that's + + + align:start position:0% +start our simplification colors that's +our divergence theorem so let's get rid + + align:start position:0% +our divergence theorem so let's get rid + + + align:start position:0% +our divergence theorem so let's get rid +of it in this form and call it minus + + align:start position:0% +of it in this form and call it minus + + + align:start position:0% +of it in this form and call it minus +integral over all that stuff then we'll + + align:start position:0% +integral over all that stuff then we'll + + + align:start position:0% +integral over all that stuff then we'll +have del dot little J to be careful R + + align:start position:0% + + + + align:start position:0% + +Omega T so for every step I'm going to + + align:start position:0% +Omega T so for every step I'm going to + + + align:start position:0% +Omega T so for every step I'm going to +use a different color so you can see + + align:start position:0% +use a different color so you can see + + + align:start position:0% +use a different color so you can see +which simplification led to how much + + align:start position:0% +which simplification led to how much + + + align:start position:0% +which simplification led to how much +crossing stuff out and so like I said + + align:start position:0% +crossing stuff out and so like I said + + + align:start position:0% +crossing stuff out and so like I said +this board is gonna look like a rainbow + + align:start position:0% +this board is gonna look like a rainbow + + + align:start position:0% +this board is gonna look like a rainbow +explosion but then we'll rewrite it at + + align:start position:0% +explosion but then we'll rewrite it at + + + align:start position:0% +explosion but then we'll rewrite it at +the end and it's gonna look a whole lot + + align:start position:0% +the end and it's gonna look a whole lot + + + align:start position:0% +the end and it's gonna look a whole lot +simpler so now let's start making some + + align:start position:0% +simpler so now let's start making some + + + align:start position:0% +simpler so now let's start making some +simplifications let's say you're an + + align:start position:0% +simplifications let's say you're an + + + align:start position:0% +simplifications let's say you're an +actual reactor designer and all you care + + align:start position:0% +actual reactor designer and all you care + + + align:start position:0% +actual reactor designer and all you care +about is how many neutrons are here of + + align:start position:0% +about is how many neutrons are here of + + + align:start position:0% +about is how many neutrons are here of +the variables here which one do you + + align:start position:0% +the variables here which one do you + + + align:start position:0% +the variables here which one do you +think we care the least about + + align:start position:0% + + + + align:start position:0% + +angle I mean do we really care which + + align:start position:0% +angle I mean do we really care which + + + align:start position:0% +angle I mean do we really care which +direction the neutrons are going no we + + align:start position:0% +direction the neutrons are going no we + + + align:start position:0% +direction the neutrons are going no we +pretty much care where are they and are + + align:start position:0% +pretty much care where are they and are + + + align:start position:0% +pretty much care where are they and are +they causing fission or getting absorbed + + align:start position:0% +they causing fission or getting absorbed + + + align:start position:0% +they causing fission or getting absorbed +so let's start our simplification board + + align:start position:0% +so let's start our simplification board + + + align:start position:0% +so let's start our simplification board +and in blue neglect angle this is where + + align:start position:0% +and in blue neglect angle this is where + + + align:start position:0% +and in blue neglect angle this is where +it starts to get fun so in this case we + + align:start position:0% +it starts to get fun so in this case we + + + align:start position:0% +it starts to get fun so in this case we +will just perform the Omega integral + + align:start position:0% +will just perform the Omega integral + + + align:start position:0% +will just perform the Omega integral +over all angles we just neglect angle + + align:start position:0% +over all angles we just neglect angle + + + align:start position:0% +over all angles we just neglect angle +here we forget the Omega integral forget + + align:start position:0% +here we forget the Omega integral forget + + + align:start position:0% +here we forget the Omega integral forget +Omega there away goes the 4 pi because + + align:start position:0% +Omega there away goes the 4 pi because + + + align:start position:0% +Omega there away goes the 4 pi because +we've integrated over all 4 pi star ad + + align:start position:0% +we've integrated over all 4 pi star ad + + + align:start position:0% +we've integrated over all 4 pi star ad +ins or all solid angle and let's just + + align:start position:0% +ins or all solid angle and let's just + + + align:start position:0% +ins or all solid angle and let's just +keep going + + align:start position:0% +keep going + + + align:start position:0% +keep going +forget the 4 pi forget the Omega forget + + align:start position:0% +forget the 4 pi forget the Omega forget + + + align:start position:0% +forget the 4 pi forget the Omega forget +the Omega forget the 4 PI and the Omega + + align:start position:0% +the Omega forget the 4 PI and the Omega + + + align:start position:0% +the Omega forget the 4 PI and the Omega +and the Omega same thing here + + align:start position:0% +and the Omega same thing here + + + align:start position:0% +and the Omega same thing here +forget the Omega in the scattering + + align:start position:0% +forget the Omega in the scattering + + + align:start position:0% +forget the Omega in the scattering +kernel forget it in the flux forget it + + align:start position:0% +kernel forget it in the flux forget it + + + align:start position:0% +kernel forget it in the flux forget it +there forget it there and there as well + + align:start position:0% +there forget it there and there as well + + + align:start position:0% +there forget it there and there as well +okay we've now completely eliminated one + + align:start position:0% +okay we've now completely eliminated one + + + align:start position:0% +okay we've now completely eliminated one +variable and all we had to do is ditch + + align:start position:0% +variable and all we had to do is ditch + + + align:start position:0% +variable and all we had to do is ditch +the for PI's and one of the integrals + + align:start position:0% +the for PI's and one of the integrals + + + align:start position:0% +the for PI's and one of the integrals +what next we're tracking right now every + + align:start position:0% +what next we're tracking right now every + + + align:start position:0% +what next we're tracking right now every +possible position every possible energy + + align:start position:0% +possible position every possible energy + + + align:start position:0% +possible position every possible energy +at every possible time if you want to + + align:start position:0% +at every possible time if you want to + + + align:start position:0% +at every possible time if you want to +know what is your flux going to be in + + align:start position:0% +know what is your flux going to be in + + + align:start position:0% +know what is your flux going to be in +the reactor at steady state what + + align:start position:0% +the reactor at steady state what + + + align:start position:0% +the reactor at steady state what +variable do you attack next yep time so + + align:start position:0% +variable do you attack next yep time so + + + align:start position:0% +variable do you attack next yep time so +let's just say this reactor is at steady + + align:start position:0% +let's just say this reactor is at steady + + + align:start position:0% +let's just say this reactor is at steady +state that's going to invoke a few + + align:start position:0% +state that's going to invoke a few + + + align:start position:0% +state that's going to invoke a few +things for one it's going to ditch the + + align:start position:0% +things for one it's going to ditch the + + + align:start position:0% +things for one it's going to ditch the +entire steady state term we're gonna get + + align:start position:0% +entire steady state term we're gonna get + + + align:start position:0% +entire steady state term we're gonna get +rid of all the T's in all the fluxes + + align:start position:0% +rid of all the T's in all the fluxes + + + align:start position:0% +rid of all the T's in all the fluxes +this shouldn't take too long to do I + + align:start position:0% +this shouldn't take too long to do I + + + align:start position:0% +this shouldn't take too long to do I +think that's all of them and the third + + align:start position:0% +think that's all of them and the third + + + align:start position:0% +think that's all of them and the third +thing is if this reactor is at steady + + align:start position:0% +thing is if this reactor is at steady + + + align:start position:0% +thing is if this reactor is at steady +state chances are we've taken our + + align:start position:0% +state chances are we've taken our + + + align:start position:0% +state chances are we've taken our +Kickstarter source out because we just + + align:start position:0% +Kickstarter source out because we just + + + align:start position:0% +Kickstarter source out because we just +needed it to get it going but the + + align:start position:0% +needed it to get it going but the + + + align:start position:0% +needed it to get it going but the +reactor should be self-sustaining once + + align:start position:0% +reactor should be self-sustaining once + + + align:start position:0% +reactor should be self-sustaining once +it's at steady state so let's just get + + align:start position:0% +it's at steady state so let's just get + + + align:start position:0% +it's at steady state so let's just get +rid of our source term so you just want + + align:start position:0% +rid of our source term so you just want + + + align:start position:0% +rid of our source term so you just want +to make sure I didn't miss any here okay + + align:start position:0% +to make sure I didn't miss any here okay + + + align:start position:0% +to make sure I didn't miss any here okay +next up go with green what else do you + + align:start position:0% +next up go with green what else do you + + + align:start position:0% +next up go with green what else do you +think we can simplify about this problem + + align:start position:0% + + + + align:start position:0% + +well if you look far enough away from + + align:start position:0% +well if you look far enough away from + + + align:start position:0% +well if you look far enough away from +the reactor we can make an assumption + + align:start position:0% +the reactor we can make an assumption + + + align:start position:0% +the reactor we can make an assumption +that the reactor is roughly homogeneous + + align:start position:0% + + + + align:start position:0% + +in some cases it's not so good of an + + align:start position:0% +in some cases it's not so good of an + + + align:start position:0% +in some cases it's not so good of an +assumption like very close to anything + + align:start position:0% +assumption like very close to anything + + + align:start position:0% +assumption like very close to anything +that has a huge absorption cross-section + + align:start position:0% +that has a huge absorption cross-section + + + align:start position:0% +that has a huge absorption cross-section +now I want to explain the physics behind + + align:start position:0% +now I want to explain the physics behind + + + align:start position:0% +now I want to explain the physics behind +this if the neutrons travel a very long + + align:start position:0% +this if the neutrons travel a very long + + + align:start position:0% +this if the neutrons travel a very long +distance through any group of materials + + align:start position:0% +distance through any group of materials + + + align:start position:0% +distance through any group of materials +then those materials will appear to be + + align:start position:0% +then those materials will appear to be + + + align:start position:0% +then those materials will appear to be +roughly homogeneous to the neutrons if + + align:start position:0% +roughly homogeneous to the neutrons if + + + align:start position:0% +roughly homogeneous to the neutrons if +however the neutrons travel through + + align:start position:0% +however the neutrons travel through + + + align:start position:0% +however the neutrons travel through +something that's very different from the + + align:start position:0% +something that's very different from the + + + align:start position:0% +something that's very different from the +materials around it then that + + align:start position:0% +materials around it then that + + + align:start position:0% +materials around it then that +homogeneous assumption breaks down so in + + align:start position:0% +homogeneous assumption breaks down so in + + + align:start position:0% +homogeneous assumption breaks down so in +what locations in a nuclear reactor do + + align:start position:0% +what locations in a nuclear reactor do + + + align:start position:0% +what locations in a nuclear reactor do +you think you cannot treat the system is + + align:start position:0% +you think you cannot treat the system is + + + align:start position:0% +you think you cannot treat the system is +homogeneous where do the properties of + + align:start position:0% +homogeneous where do the properties of + + + align:start position:0% +homogeneous where do the properties of +materials suddenly change by a huge + + align:start position:0% +materials suddenly change by a huge + + + align:start position:0% +materials suddenly change by a huge +amount yeah Luke control rods right so + + align:start position:0% +amount yeah Luke control rods right so + + + align:start position:0% +amount yeah Luke control rods right so +let's say it's bad for control rods + + align:start position:0% + + + + align:start position:0% + +where else + + align:start position:0% + + + + align:start position:0% + +how about the fuel all of a sudden + + align:start position:0% +how about the fuel all of a sudden + + + align:start position:0% +how about the fuel all of a sudden +you're moving from a bunch of structural + + align:start position:0% +you're moving from a bunch of structural + + + align:start position:0% +you're moving from a bunch of structural +materials where Sigma fission equals + + align:start position:0% +materials where Sigma fission equals + + + align:start position:0% +materials where Sigma fission equals +zero to the fuel where Sigma fission + + align:start position:0% +zero to the fuel where Sigma fission + + + align:start position:0% +zero to the fuel where Sigma fission +like you saw in the test can be like + + align:start position:0% +like you saw in the test can be like + + + align:start position:0% +like you saw in the test can be like +five hundred barns which even though + + align:start position:0% +five hundred barns which even though + + + align:start position:0% +five hundred barns which even though +it's got a very small exponent in front + + align:start position:0% +it's got a very small exponent in front + + + align:start position:0% +it's got a very small exponent in front +of it ten to the minus 22 centimeters + + align:start position:0% +of it ten to the minus 22 centimeters + + + align:start position:0% +of it ten to the minus 22 centimeters +squared it's still pretty significant so + + align:start position:0% +squared it's still pretty significant so + + + align:start position:0% +squared it's still pretty significant so +this assumption breaks down around the + + align:start position:0% +this assumption breaks down around the + + + align:start position:0% +this assumption breaks down around the +control rods and around the fuel but we + + align:start position:0% +control rods and around the fuel but we + + + align:start position:0% +control rods and around the fuel but we +can get around this let's analyze the + + align:start position:0% +can get around this let's analyze the + + + align:start position:0% +can get around this let's analyze the +simplest crazy as possible reactor which + + align:start position:0% +simplest crazy as possible reactor which + + + align:start position:0% +simplest crazy as possible reactor which +would be a molten salt fueled reactor + + align:start position:0% +would be a molten salt fueled reactor + + + align:start position:0% +would be a molten salt fueled reactor +it's just a blob of 700 Celsius goo + + align:start position:0% +it's just a blob of 700 Celsius goo + + + align:start position:0% +it's just a blob of 700 Celsius goo +that's got its fuel coolant and control + + align:start position:0% +that's got its fuel coolant and control + + + align:start position:0% +that's got its fuel coolant and control +rods all built in so if we assume that + + align:start position:0% +rods all built in so if we assume that + + + align:start position:0% +rods all built in so if we assume that +the reactor is homogeneous which is a + + align:start position:0% +the reactor is homogeneous which is a + + + align:start position:0% +the reactor is homogeneous which is a +pretty good assumption for molten salt + + align:start position:0% +pretty good assumption for molten salt + + + align:start position:0% +pretty good assumption for molten salt +fueled reactors because the fuels + + align:start position:0% +fueled reactors because the fuels + + + align:start position:0% +fueled reactors because the fuels +dissolved in the coolant and it builds + + align:start position:0% +dissolved in the coolant and it builds + + + align:start position:0% +dissolved in the coolant and it builds +up its own fission product poisons so + + align:start position:0% +up its own fission product poisons so + + + align:start position:0% +up its own fission product poisons so +it's got some of its own control rods + + align:start position:0% +it's got some of its own control rods + + + align:start position:0% +it's got some of its own control rods +kind of built in usually will have other + + align:start position:0% +kind of built in usually will have other + + + align:start position:0% +kind of built in usually will have other +extra ones too but whatever then we can + + align:start position:0% +extra ones too but whatever then we can + + + align:start position:0% +extra ones too but whatever then we can +start to really simplify things if we + + align:start position:0% +start to really simplify things if we + + + align:start position:0% +start to really simplify things if we +get rid of any homogeneity assumptions + + align:start position:0% +get rid of any homogeneity assumptions + + + align:start position:0% +get rid of any homogeneity assumptions +we cannot necessarily get rid of the R + + align:start position:0% +we cannot necessarily get rid of the R + + + align:start position:0% +we cannot necessarily get rid of the R +in the flux because even if the reactors + + align:start position:0% +in the flux because even if the reactors + + + align:start position:0% +in the flux because even if the reactors +homogeneous it still might have + + align:start position:0% +homogeneous it still might have + + + align:start position:0% +homogeneous it still might have +boundaries so you might be able to + + align:start position:0% +boundaries so you might be able to + + + align:start position:0% +boundaries so you might be able to +approximate it as just a cylinder or a + + align:start position:0% +approximate it as just a cylinder or a + + + align:start position:0% +approximate it as just a cylinder or a +slab of uniform materials but if we were + + align:start position:0% +slab of uniform materials but if we were + + + align:start position:0% +slab of uniform materials but if we were +to get rid of the R's in the flux term + + align:start position:0% +to get rid of the R's in the flux term + + + align:start position:0% +to get rid of the R's in the flux term +that would mean that as we graph flux as + + align:start position:0% +that would mean that as we graph flux as + + + align:start position:0% +that would mean that as we graph flux as +a function of distance it would look + + align:start position:0% +a function of distance it would look + + + align:start position:0% +a function of distance it would look +like that + + align:start position:0% + + + + align:start position:0% + +including infinitely far away from the + + align:start position:0% +including infinitely far away from the + + + align:start position:0% +including infinitely far away from the +reactor and now is that true absolutely + + align:start position:0% +reactor and now is that true absolutely + + + align:start position:0% +reactor and now is that true absolutely +not so I don't want to leave that up for + + align:start position:0% +not so I don't want to leave that up for + + + align:start position:0% +not so I don't want to leave that up for +anyone we'll fill in what these graphs + + align:start position:0% +anyone we'll fill in what these graphs + + + align:start position:0% +anyone we'll fill in what these graphs +look like a little later just leave them + + align:start position:0% +look like a little later just leave them + + + align:start position:0% +look like a little later just leave them +there for now we can get rid of some of + + align:start position:0% +there for now we can get rid of some of + + + align:start position:0% +there for now we can get rid of some of +the other ARS though like these + + align:start position:0% +the other ARS though like these + + + align:start position:0% +the other ARS though like these +cross-sections if the reactor is + + align:start position:0% +cross-sections if the reactor is + + + align:start position:0% +cross-sections if the reactor is +actually homogeneous then the + + align:start position:0% +actually homogeneous then the + + + align:start position:0% +actually homogeneous then the +cross-section is the same everywhere + + align:start position:0% +cross-section is the same everywhere + + + align:start position:0% +cross-section is the same everywhere +because the materials are the same + + align:start position:0% +because the materials are the same + + + align:start position:0% +because the materials are the same +everywhere so we can get rid of the ARS + + align:start position:0% +everywhere so we can get rid of the ARS + + + align:start position:0% +everywhere so we can get rid of the ARS +here the R's here and there and there + + align:start position:0% +here the R's here and there and there + + + align:start position:0% +here the R's here and there and there +and that's it I think don't think I + + align:start position:0% +and that's it I think don't think I + + + align:start position:0% +and that's it I think don't think I +missed any good next up if this reactors + + align:start position:0% +missed any good next up if this reactors + + + align:start position:0% +missed any good next up if this reactors +homogeneous then does it really matter + + align:start position:0% +homogeneous then does it really matter + + + align:start position:0% +homogeneous then does it really matter +at which location were taking this + + align:start position:0% +at which location were taking this + + + align:start position:0% +at which location were taking this +balance does it really matter which + + align:start position:0% +balance does it really matter which + + + align:start position:0% +balance does it really matter which +little volume element we're looking at + + align:start position:0% +little volume element we're looking at + + + align:start position:0% +little volume element we're looking at +we say these equations are will call + + align:start position:0% +we say these equations are will call + + + align:start position:0% +we say these equations are will call +them volume identical which means if + + align:start position:0% +them volume identical which means if + + + align:start position:0% +them volume identical which means if +this same equation is satisfied at any + + align:start position:0% +this same equation is satisfied at any + + + align:start position:0% +this same equation is satisfied at any +point in the reactor we don't need to do + + align:start position:0% +point in the reactor we don't need to do + + + align:start position:0% +point in the reactor we don't need to do +the volume integral over the whole + + align:start position:0% +the volume integral over the whole + + + align:start position:0% +the volume integral over the whole +reactor it's not like it's gonna change + + align:start position:0% +reactor it's not like it's gonna change + + + align:start position:0% +reactor it's not like it's gonna change +anywhere we go so forget the volume + + align:start position:0% +anywhere we go so forget the volume + + + align:start position:0% +anywhere we go so forget the volume +integrals hopefully you guys see where + + align:start position:0% +integrals hopefully you guys see where + + + align:start position:0% +integrals hopefully you guys see where +I'm going with this and I've never I've + + align:start position:0% +I'm going with this and I've never I've + + + align:start position:0% +I'm going with this and I've never I've +never tried teaching it like this + + align:start position:0% +never tried teaching it like this + + + align:start position:0% +never tried teaching it like this +rainbow explosion before but I'm kind of + + align:start position:0% +rainbow explosion before but I'm kind of + + + align:start position:0% +rainbow explosion before but I'm kind of +excited to see how it turns out + + align:start position:0% +excited to see how it turns out + + + align:start position:0% +excited to see how it turns out +so already like 2/3 of the stuff that we + + align:start position:0% +so already like 2/3 of the stuff that we + + + align:start position:0% +so already like 2/3 of the stuff that we +had written are gone what's the only + + align:start position:0% +had written are gone what's the only + + + align:start position:0% +had written are gone what's the only +variable left that we can go after and + + align:start position:0% +variable left that we can go after and + + + align:start position:0% +variable left that we can go after and +what's the only color left that I + + align:start position:0% +what's the only color left that I + + + align:start position:0% +what's the only color left that I +haven't really used energy yeah so we + + align:start position:0% +haven't really used energy yeah so we + + + align:start position:0% +haven't really used energy yeah so we +can make a couple of us different + + align:start position:0% +can make a couple of us different + + + align:start position:0% +can make a couple of us different +assumptions this equation as it is is + + align:start position:0% +assumptions this equation as it is is + + + align:start position:0% +assumptions this equation as it is is +not yet really analytically solvable + + align:start position:0% +not yet really analytically solvable + + + align:start position:0% +not yet really analytically solvable +because a lot of these energy dependent + + align:start position:0% +because a lot of these energy dependent + + + align:start position:0% +because a lot of these energy dependent +terms don't have analytical solutions or + + align:start position:0% +terms don't have analytical solutions or + + + align:start position:0% +terms don't have analytical solutions or +even forms like the cross-sections but + + align:start position:0% +even forms like the cross-sections but + + + align:start position:0% +even forms like the cross-sections but +we can start attacking energy hopefully + + align:start position:0% +we can start attacking energy hopefully + + + align:start position:0% +we can start attacking energy hopefully +this is different enough from white yeah + + align:start position:0% +this is different enough from white yeah + + + align:start position:0% +this is different enough from white yeah +is that big enough difference for you + + align:start position:0% +is that big enough difference for you + + + align:start position:0% +is that big enough difference for you +guys to see good ok we can start doing + + align:start position:0% +guys to see good ok we can start doing + + + align:start position:0% +guys to see good ok we can start doing +this in a few different ways I want to + + align:start position:0% +this in a few different ways I want to + + + align:start position:0% +this in a few different ways I want to +mention what they are and then we're + + align:start position:0% +mention what they are and then we're + + + align:start position:0% +mention what they are and then we're +gonna do the easiest one + + align:start position:0% +gonna do the easiest one + + + align:start position:0% +gonna do the easiest one +so the way it's done for real like in + + align:start position:0% +so the way it's done for real like in + + + align:start position:0% +so the way it's done for real like in +the computational reactor physics group + + align:start position:0% +the computational reactor physics group + + + align:start position:0% +the computational reactor physics group +is you can discretize the energy + + align:start position:0% + + + + align:start position:0% + +discretize the energy into a bunch of + + align:start position:0% +discretize the energy into a bunch of + + + align:start position:0% +discretize the energy into a bunch of +little energy groups so you can write + + align:start position:0% +little energy groups so you can write + + + align:start position:0% +little energy groups so you can write +this equation for every little energy + + align:start position:0% +this equation for every little energy + + + align:start position:0% +this equation for every little energy +group and assume that along this energy + + align:start position:0% +group and assume that along this energy + + + align:start position:0% +group and assume that along this energy +scale ranging from your maximum energy + + align:start position:0% +scale ranging from your maximum energy + + + align:start position:0% +scale ranging from your maximum energy +to probably thermal energy yeah oh to + + align:start position:0% +to probably thermal energy yeah oh to + + + align:start position:0% +to probably thermal energy yeah oh to +five okay let's do this clearly with + + align:start position:0% +five okay let's do this clearly with + + + align:start position:0% +five okay let's do this clearly with +thick chalk there we go + + align:start position:0% +thick chalk there we go + + + align:start position:0% +thick chalk there we go +you can then discretize into some little + + align:start position:0% +you can then discretize into some little + + + align:start position:0% +you can then discretize into some little +energy group let's say that's eg I + + align:start position:0% +energy group let's say that's eg I + + + align:start position:0% +energy group let's say that's eg I +that's eg I plus one and so on and so on + + align:start position:0% +that's eg I plus one and so on and so on + + + align:start position:0% +that's eg I plus one and so on and so on +and depending on the type of reactor + + align:start position:0% +and depending on the type of reactor + + + align:start position:0% +and depending on the type of reactor +that you're looking at and the energy + + align:start position:0% +that you're looking at and the energy + + + align:start position:0% +that you're looking at and the energy +resolution that you need you choose the + + align:start position:0% +resolution that you need you choose the + + + align:start position:0% +resolution that you need you choose the +number of energy groups accordingly does + + align:start position:0% +number of energy groups accordingly does + + + align:start position:0% +number of energy groups accordingly does +anyone happen to know for a light water + + align:start position:0% +anyone happen to know for a light water + + + align:start position:0% +anyone happen to know for a light water +reactor how many energy groups do you + + align:start position:0% +reactor how many energy groups do you + + + align:start position:0% +reactor how many energy groups do you +think we need to model a light water + + align:start position:0% +think we need to model a light water + + + align:start position:0% +think we need to model a light water +reactor the answer might surprise you + + align:start position:0% +reactor the answer might surprise you + + + align:start position:0% +reactor the answer might surprise you +it's just two actually all we care about + + align:start position:0% +it's just two actually all we care about + + + align:start position:0% +it's just two actually all we care about +so let's say this would be for the + + align:start position:0% +so let's say this would be for the + + + align:start position:0% +so let's say this would be for the +general case all we care about for a + + align:start position:0% +general case all we care about for a + + + align:start position:0% +general case all we care about for a +light water reactor is are your neutrons + + align:start position:0% +light water reactor is are your neutrons + + + align:start position:0% +light water reactor is are your neutrons +thermal or are they not because the + + align:start position:0% +thermal or are they not because the + + + align:start position:0% +thermal or are they not because the +neutrons that are not thermal are not + + align:start position:0% +neutrons that are not thermal are not + + + align:start position:0% +neutrons that are not thermal are not +contributing to fission that much they + + align:start position:0% +contributing to fission that much they + + + align:start position:0% +contributing to fission that much they +are just a little bit and you can + + align:start position:0% +are just a little bit and you can + + + align:start position:0% +are just a little bit and you can +account for those but pretty much + + align:start position:0% +account for those but pretty much + + + align:start position:0% +account for those but pretty much +they're not once the neutrons slow down + + align:start position:0% +they're not once the neutrons slow down + + + align:start position:0% +they're not once the neutrons slow down +to get thermal in the range from like + + align:start position:0% +to get thermal in the range from like + + + align:start position:0% +to get thermal in the range from like +let's say about an e V to that + + align:start position:0% +let's say about an e V to that + + + align:start position:0% +let's say about an e V to that +temperature took a surprising amount of + + align:start position:0% +temperature took a surprising amount of + + + align:start position:0% +temperature took a surprising amount of +time to write with sidewalk chalk then + + align:start position:0% +time to write with sidewalk chalk then + + + align:start position:0% +time to write with sidewalk chalk then +you've got things that are about 500 or + + align:start position:0% +you've got things that are about 500 or + + + align:start position:0% +you've got things that are about 500 or +a thousand times more likely to undergo + + align:start position:0% +a thousand times more likely to undergo + + + align:start position:0% +a thousand times more likely to undergo +fission and so all you care about is the + + align:start position:0% +fission and so all you care about is the + + + align:start position:0% +fission and so all you care about is the +neutrons are all born they're all born + + align:start position:0% +neutrons are all born they're all born + + + align:start position:0% +neutrons are all born they're all born +right about here and they scatter + + align:start position:0% +right about here and they scatter + + + align:start position:0% +right about here and they scatter +and bounce around and you don't care + + align:start position:0% +and bounce around and you don't care + + + align:start position:0% +and bounce around and you don't care +because they're just in this not thermal + + align:start position:0% +because they're just in this not thermal + + + align:start position:0% +because they're just in this not thermal +region and when they enter the thermal + + align:start position:0% +region and when they enter the thermal + + + align:start position:0% +region and when they enter the thermal +region you start tracking them because + + align:start position:0% +region you start tracking them because + + + align:start position:0% +region you start tracking them because +those are the ones that really count for + + align:start position:0% +those are the ones that really count for + + + align:start position:0% +those are the ones that really count for +fission and if you actually look up the + + align:start position:0% +fission and if you actually look up the + + + align:start position:0% +fission and if you actually look up the +specifications for the ap1000 this is a + + align:start position:0% +specifications for the ap1000 this is a + + + align:start position:0% +specifications for the ap1000 this is a +modern reactor under construction in + + align:start position:0% +modern reactor under construction in + + + align:start position:0% +modern reactor under construction in +many different places in the world when + + align:start position:0% +many different places in the world when + + + align:start position:0% +many different places in the world when +you see how do they do the neutronic + + align:start position:0% +you see how do they do the neutronic + + + align:start position:0% +you see how do they do the neutronic +analysis two group approximation so this + + align:start position:0% +analysis two group approximation so this + + + align:start position:0% +analysis two group approximation so this +isn't just an academic exercise to make + + align:start position:0% +isn't just an academic exercise to make + + + align:start position:0% +isn't just an academic exercise to make +it easier for sophomores to understand + + align:start position:0% +it easier for sophomores to understand + + + align:start position:0% +it easier for sophomores to understand +this is actually something that's done + + align:start position:0% +this is actually something that's done + + + align:start position:0% +this is actually something that's done +for real reactors so if you ever felt + + align:start position:0% +for real reactors so if you ever felt + + + align:start position:0% +for real reactors so if you ever felt +like I'm making it too simple no no this + + align:start position:0% +like I'm making it too simple no no this + + + align:start position:0% +like I'm making it too simple no no this +is I'm simplifying it down to what's + + align:start position:0% +is I'm simplifying it down to what's + + + align:start position:0% +is I'm simplifying it down to what's +really done and I will get you that + + align:start position:0% +really done and I will get you that + + + align:start position:0% +really done and I will get you that +specification so you can see what + + align:start position:0% +specification so you can see what + + + align:start position:0% +specification so you can see what +westinghouse says like this is how we + + align:start position:0% +westinghouse says like this is how we + + + align:start position:0% +westinghouse says like this is how we +design the reactor we made a two group + + align:start position:0% +design the reactor we made a two group + + + align:start position:0% +design the reactor we made a two group +simplification in many cases so you can + + align:start position:0% +simplification in many cases so you can + + + align:start position:0% +simplification in many cases so you can +discretize you can forget it + + align:start position:0% +discretize you can forget it + + + align:start position:0% +discretize you can forget it +which we're going to call the one group + + align:start position:0% +which we're going to call the one group + + + align:start position:0% +which we're going to call the one group +approximation or you can well let's say + + align:start position:0% +approximation or you can well let's say + + + align:start position:0% +approximation or you can well let's say +two group is the other one that we're + + align:start position:0% +two group is the other one that we're + + + align:start position:0% +two group is the other one that we're +actually gonna tackle we're gonna do + + align:start position:0% +actually gonna tackle we're gonna do + + + align:start position:0% +actually gonna tackle we're gonna do +this one forget energy but we're not + + align:start position:0% +this one forget energy but we're not + + + align:start position:0% +this one forget energy but we're not +really going to forget energy because + + align:start position:0% +really going to forget energy because + + + align:start position:0% +really going to forget energy because +you can't just pick an energy and pick a + + align:start position:0% +you can't just pick an energy and pick a + + + align:start position:0% +you can't just pick an energy and pick a +cross-section and say okay that's the + + align:start position:0% +cross-section and say okay that's the + + + align:start position:0% +cross-section and say okay that's the +cross-section we're going to use if most + + align:start position:0% +cross-section we're going to use if most + + + align:start position:0% +cross-section we're going to use if most +cross-sections have the following form + + align:start position:0% +cross-sections have the following form + + + align:start position:0% +cross-sections have the following form +if this is log of energy and this is log + + align:start position:0% +if this is log of energy and this is log + + + align:start position:0% +if this is log of energy and this is log +of Sigma and it goes something like that + + align:start position:0% +of Sigma and it goes something like that + + + align:start position:0% +of Sigma and it goes something like that +what energy do you pick go ahead tell me + + align:start position:0% +what energy do you pick go ahead tell me + + + align:start position:0% +what energy do you pick go ahead tell me +which energy do you pick anyone want to + + align:start position:0% +which energy do you pick anyone want to + + + align:start position:0% +which energy do you pick anyone want to +wager a guess + + align:start position:0% + + + + align:start position:0% + +the ones before after the big squigglies + + align:start position:0% +the ones before after the big squigglies + + + align:start position:0% +the ones before after the big squigglies +I don't think that's correct because if + + align:start position:0% +I don't think that's correct because if + + + align:start position:0% +I don't think that's correct because if +you do it this then you're gonna weigh + + align:start position:0% +you do it this then you're gonna weigh + + + align:start position:0% +you do it this then you're gonna weigh +underestimate vision if you do it here + + align:start position:0% +underestimate vision if you do it here + + + align:start position:0% +underestimate vision if you do it here +you're gonna weigh overestimate vision + + align:start position:0% +you're gonna weigh overestimate vision + + + align:start position:0% +you're gonna weigh overestimate vision +or whatever rank we have the reaction + + align:start position:0% +or whatever rank we have the reaction + + + align:start position:0% +or whatever rank we have the reaction +you have we didn't say which reaction + + align:start position:0% +you have we didn't say which reaction + + + align:start position:0% +you have we didn't say which reaction +this is the rest of you who are silent + + align:start position:0% +this is the rest of you who are silent + + + align:start position:0% +this is the rest of you who are silent +and afraid to speak up you're actually + + align:start position:0% +and afraid to speak up you're actually + + + align:start position:0% +and afraid to speak up you're actually +correct I wouldn't actually pick any + + align:start position:0% +correct I wouldn't actually pick any + + + align:start position:0% +correct I wouldn't actually pick any +single value here what you need to do is + + align:start position:0% +single value here what you need to do is + + + align:start position:0% +single value here what you need to do is +find some sort of average cross-section + + align:start position:0% +find some sort of average cross-section + + + align:start position:0% +find some sort of average cross-section +for whatever reaction that accurately + + align:start position:0% +for whatever reaction that accurately + + + align:start position:0% +for whatever reaction that accurately +represents the number of reactions + + align:start position:0% +represents the number of reactions + + + align:start position:0% +represents the number of reactions +happening in the system and in order to + + align:start position:0% +happening in the system and in order to + + + align:start position:0% +happening in the system and in order to +do that you have to come up with some + + align:start position:0% +do that you have to come up with some + + + align:start position:0% +do that you have to come up with some +average cross-section for whatever + + align:start position:0% +average cross-section for whatever + + + align:start position:0% +average cross-section for whatever +reaction you have by integrating over + + align:start position:0% +reaction you have by integrating over + + + align:start position:0% +reaction you have by integrating over +your whole energy range of the energy + + align:start position:0% +your whole energy range of the energy + + + align:start position:0% +your whole energy range of the energy +dependent cross-section as a function of + + align:start position:0% +dependent cross-section as a function of + + + align:start position:0% +dependent cross-section as a function of +energy times your flux de over this look + + align:start position:0% +energy times your flux de over this look + + + align:start position:0% +energy times your flux de over this look +familiar from 1801 or two as well what's + + align:start position:0% +familiar from 1801 or two as well what's + + + align:start position:0% +familiar from 1801 or two as well what's +the average value of some function a + + align:start position:0% +the average value of some function a + + + align:start position:0% +the average value of some function a +little bit well we'll bring it back here + + align:start position:0% +little bit well we'll bring it back here + + + align:start position:0% +little bit well we'll bring it back here +now so retrieve it from cold storage in + + align:start position:0% +now so retrieve it from cold storage in + + + align:start position:0% +now so retrieve it from cold storage in +your memories because this is how actual + + align:start position:0% +your memories because this is how actual + + + align:start position:0% +your memories because this is how actual +cross-sections are averaged for whatever + + align:start position:0% +cross-sections are averaged for whatever + + + align:start position:0% +cross-sections are averaged for whatever +energy range you're picking you know + + align:start position:0% +energy range you're picking you know + + + align:start position:0% +energy range you're picking you know +what I'm gonna make this a little more + + align:start position:0% +what I'm gonna make this a little more + + + align:start position:0% +what I'm gonna make this a little more +general I won't say zero I'll just say + + align:start position:0% +general I won't say zero I'll just say + + + align:start position:0% +general I won't say zero I'll just say +your minimum energy for your group so + + align:start position:0% +your minimum energy for your group so + + + align:start position:0% +your minimum energy for your group so +now this equation is general for the + + align:start position:0% +now this equation is general for the + + + align:start position:0% +now this equation is general for the +multi group and the one group and two + + align:start position:0% +multi group and the one group and two + + + align:start position:0% +multi group and the one group and two +group method for whatever cross-section + + align:start position:0% +group method for whatever cross-section + + + align:start position:0% +group method for whatever cross-section +you want to pick and whatever energy + + align:start position:0% +you want to pick and whatever energy + + + align:start position:0% +you want to pick and whatever energy +range you're looking at you take the + + align:start position:0% +range you're looking at you take the + + + align:start position:0% +range you're looking at you take the +actual data and perform an average for + + align:start position:0% +actual data and perform an average for + + + align:start position:0% +actual data and perform an average for +the fast and thermal delineation where + + align:start position:0% +the fast and thermal delineation where + + + align:start position:0% +the fast and thermal delineation where +let's say this is fast and this is + + align:start position:0% +let's say this is fast and this is + + + align:start position:0% +let's say this is fast and this is +thermal you would have two different + + align:start position:0% +thermal you would have two different + + + align:start position:0% +thermal you would have two different +averages maybe this average would be + + align:start position:0% +averages maybe this average would be + + + align:start position:0% +averages maybe this average would be +right there you know what let's use + + align:start position:0% +right there you know what let's use + + + align:start position:0% +right there you know what let's use +white so it actually has some contrast + + align:start position:0% +white so it actually has some contrast + + + align:start position:0% +white so it actually has some contrast +so this would be one value of the + + align:start position:0% +so this would be one value of the + + + align:start position:0% +so this would be one value of the +cross-section and maybe the next average + + align:start position:0% +cross-section and maybe the next average + + + align:start position:0% +cross-section and maybe the next average +would be right there so you simplify + + align:start position:0% +would be right there so you simplify + + + align:start position:0% +would be right there so you simplify +this absolutely non analytical + + align:start position:0% +this absolutely non analytical + + + align:start position:0% +this absolutely non analytical +form of your complicated cross-section + + align:start position:0% +form of your complicated cross-section + + + align:start position:0% +form of your complicated cross-section +to just a couple of values maybe we'll + + align:start position:0% +to just a couple of values maybe we'll + + + align:start position:0% +to just a couple of values maybe we'll +call that average Sigma fast and we'll + + align:start position:0% +call that average Sigma fast and we'll + + + align:start position:0% +call that average Sigma fast and we'll +call that average Sigma thermal + + align:start position:0% + + + + align:start position:0% + +so using this analogy and this color we + + align:start position:0% +so using this analogy and this color we + + + align:start position:0% +so using this analogy and this color we +can then say we're gonna take an average + + align:start position:0% +can then say we're gonna take an average + + + align:start position:0% +can then say we're gonna take an average +new an average CAI get rid of the + + align:start position:0% +new an average CAI get rid of the + + + align:start position:0% +new an average CAI get rid of the +energies because we can perform the same + + align:start position:0% +energies because we can perform the same + + + align:start position:0% +energies because we can perform the same +energy average integration on every + + align:start position:0% +energy average integration on every + + + align:start position:0% +energy average integration on every +quantity with energy dependence so all + + align:start position:0% +quantity with energy dependence so all + + + align:start position:0% +quantity with energy dependence so all +we do is we put a bar there ditch the + + align:start position:0% +we do is we put a bar there ditch the + + + align:start position:0% +we do is we put a bar there ditch the +energies + + align:start position:0% +energies + + + align:start position:0% +energies +it's the energies and let's just say + + align:start position:0% +it's the energies and let's just say + + + align:start position:0% +it's the energies and let's just say +that flux is going to be what it is + + align:start position:0% +that flux is going to be what it is + + + align:start position:0% +that flux is going to be what it is +same thing here yeah same thing there + + align:start position:0% +same thing here yeah same thing there + + + align:start position:0% +same thing here yeah same thing there +and there and there they're there + + align:start position:0% +and there and there they're there + + + align:start position:0% +and there and there they're there +they're here and here and here and + + align:start position:0% +they're here and here and here and + + + align:start position:0% +they're here and here and here and +there's a cross-section there's an + + align:start position:0% +there's a cross-section there's an + + + align:start position:0% +there's a cross-section there's an +energy there's an energy there is a + + align:start position:0% +energy there's an energy there is a + + + align:start position:0% +energy there's an energy there is a +cross-section we don't care about those + + align:start position:0% +cross-section we don't care about those + + + align:start position:0% +cross-section we don't care about those +anymore and there's a couple of other + + align:start position:0% +anymore and there's a couple of other + + + align:start position:0% +anymore and there's a couple of other +implications of this energy + + align:start position:0% +implications of this energy + + + align:start position:0% +implications of this energy +simplification what is the birth + + align:start position:0% +simplification what is the birth + + + align:start position:0% +simplification what is the birth +spectrum now what's the probability that + + align:start position:0% +spectrum now what's the probability that + + + align:start position:0% +spectrum now what's the probability that +a neutron is born in our energy group + + align:start position:0% +a neutron is born in our energy group + + + align:start position:0% +a neutron is born in our energy group +which contains all energies one yeah + + align:start position:0% +which contains all energies one yeah + + + align:start position:0% +which contains all energies one yeah +okay so forget the Chi and that one and + + align:start position:0% +okay so forget the Chi and that one and + + + align:start position:0% +okay so forget the Chi and that one and +that one and what about this scattering + + align:start position:0% +that one and what about this scattering + + + align:start position:0% +that one and what about this scattering +kernel what's the probability that a + + align:start position:0% +kernel what's the probability that a + + + align:start position:0% +kernel what's the probability that a +neutron scatters from any other energy + + align:start position:0% +neutron scatters from any other energy + + + align:start position:0% +neutron scatters from any other energy +which is already in our group into our + + align:start position:0% +which is already in our group into our + + + align:start position:0% +which is already in our group into our +group which contains all energies yeah + + align:start position:0% +group which contains all energies yeah + + + align:start position:0% +group which contains all energies yeah +scattering no longer matters when you do + + align:start position:0% +scattering no longer matters when you do + + + align:start position:0% +scattering no longer matters when you do +the one group approximation because if + + align:start position:0% +the one group approximation because if + + + align:start position:0% +the one group approximation because if +the neutron loses some of its energy + + align:start position:0% +the neutron loses some of its energy + + + align:start position:0% +the neutron loses some of its energy +it's still in our energy group because + + align:start position:0% +it's still in our energy group because + + + align:start position:0% +it's still in our energy group because +our energy group contains all energies + + align:start position:0% +our energy group contains all energies + + + align:start position:0% +our energy group contains all energies +so forget the scattering kernel and + + align:start position:0% +so forget the scattering kernel and + + + align:start position:0% +so forget the scattering kernel and +forget the energy integrals what are we + + align:start position:0% +forget the energy integrals what are we + + + align:start position:0% +forget the energy integrals what are we +actually left with not much there's no + + align:start position:0% +actually left with not much there's no + + + align:start position:0% +actually left with not much there's no +green in here yet good because I need to + + align:start position:0% +green in here yet good because I need to + + + align:start position:0% +green in here yet good because I need to +do one more thing there is no more green + + align:start position:0% +do one more thing there is no more green + + + align:start position:0% +do one more thing there is no more green +oh we did green we did time okay green + + align:start position:0% +oh we did green we did time okay green + + + align:start position:0% +oh we did green we did time okay green +red + + align:start position:0% +red + + + align:start position:0% +red +orange is if the orange I used damn it + + align:start position:0% +orange is if the orange I used damn it + + + align:start position:0% +orange is if the orange I used damn it +okay we've used those purple no we've + + align:start position:0% +okay we've used those purple no we've + + + align:start position:0% +okay we've used those purple no we've +used that oh my god we've used both + + align:start position:0% +used that oh my god we've used both + + + align:start position:0% +used that oh my god we've used both +blues bright yellow yeah yes + + align:start position:0% +blues bright yellow yeah yes + + + align:start position:0% +blues bright yellow yeah yes +chi is the fission birth spectrum the + + align:start position:0% +chi is the fission birth spectrum the + + + align:start position:0% +chi is the fission birth spectrum the +probability that a neutron is born at + + align:start position:0% +probability that a neutron is born at + + + align:start position:0% +probability that a neutron is born at +any given energy but because all + + align:start position:0% +any given energy but because all + + + align:start position:0% +any given energy but because all +neutrons are born in our energy group + + align:start position:0% +neutrons are born in our energy group + + + align:start position:0% +neutrons are born in our energy group +which contains all energies then that + + align:start position:0% +which contains all energies then that + + + align:start position:0% +which contains all energies then that +just becomes one and goes away there's + + align:start position:0% +just becomes one and goes away there's + + + align:start position:0% +just becomes one and goes away there's +there's no birth spectrum because + + align:start position:0% +there's no birth spectrum because + + + align:start position:0% +there's no birth spectrum because +they're just born in our group yes that + + align:start position:0% +they're just born in our group yes that + + + align:start position:0% +they're just born in our group yes that +makes sense yeah + + align:start position:0% +makes sense yeah + + + align:start position:0% +makes sense yeah +okay I think I found the reaction we'll + + align:start position:0% +okay I think I found the reaction we'll + + + align:start position:0% +okay I think I found the reaction we'll +only color besides black on a black + + align:start position:0% +only color besides black on a black + + + align:start position:0% +only color besides black on a black +chalkboard and white which we already + + align:start position:0% +chalkboard and white which we already + + + align:start position:0% +chalkboard and white which we already +have that I have left we also have a + + align:start position:0% +have that I have left we also have a + + + align:start position:0% +have that I have left we also have a +slightly darker shade of gray but I'm + + align:start position:0% +slightly darker shade of gray but I'm + + + align:start position:0% +slightly darker shade of gray but I'm +literally out this worked out awesome + + align:start position:0% +literally out this worked out awesome + + + align:start position:0% +literally out this worked out awesome +because there's one more thing that we + + align:start position:0% +because there's one more thing that we + + + align:start position:0% +because there's one more thing that we +want to deal with what do we even have + + align:start position:0% +want to deal with what do we even have + + + align:start position:0% +want to deal with what do we even have +left all right + + align:start position:0% +left all right + + + align:start position:0% +left all right +what is the one term that is not in all + + align:start position:0% +what is the one term that is not in all + + + align:start position:0% +what is the one term that is not in all +of the same variables as the others that + + align:start position:0% +of the same variables as the others that + + + align:start position:0% +of the same variables as the others that +current that J what do we do about that + + align:start position:0% + + + + align:start position:0% + +so we're going sorry yeah the F e to e + + align:start position:0% +so we're going sorry yeah the F e to e + + + align:start position:0% +so we're going sorry yeah the F e to e +so I'll actually I'll recreate some of + + align:start position:0% +so I'll actually I'll recreate some of + + + align:start position:0% +so I'll actually I'll recreate some of +our variables here because there's a lot + + align:start position:0% +our variables here because there's a lot + + + align:start position:0% +our variables here because there's a lot +of them so our F of e prime to e is + + align:start position:0% +of them so our F of e prime to e is + + + align:start position:0% +of them so our F of e prime to e is +what's called the scattering kernel and + + align:start position:0% +what's called the scattering kernel and + + + align:start position:0% +what's called the scattering kernel and +that's the probability that a neutron + + align:start position:0% +that's the probability that a neutron + + + align:start position:0% +that's the probability that a neutron +scatters from some other energy Group E + + align:start position:0% +scatters from some other energy Group E + + + align:start position:0% +scatters from some other energy Group E +Prime in two hours in a about de and Chi + + align:start position:0% +Prime in two hours in a about de and Chi + + + align:start position:0% +Prime in two hours in a about de and Chi +of e is the fission birth spectrum + + align:start position:0% + + + + align:start position:0% + +and just for completeness knew of e is + + align:start position:0% +and just for completeness knew of e is + + + align:start position:0% +and just for completeness knew of e is +our Neutron multiplier or neutrons per + + align:start position:0% +our Neutron multiplier or neutrons per + + + align:start position:0% +our Neutron multiplier or neutrons per +fission I think that gives a pretty + + align:start position:0% +fission I think that gives a pretty + + + align:start position:0% +fission I think that gives a pretty +complete explanation of what's up here + + align:start position:0% +complete explanation of what's up here + + + align:start position:0% +complete explanation of what's up here +so now let's figure out how to deal with + + align:start position:0% +so now let's figure out how to deal with + + + align:start position:0% +so now let's figure out how to deal with +the current term this is when we make + + align:start position:0% +the current term this is when we make + + + align:start position:0% +the current term this is when we make +one of the biggest approximations here + + align:start position:0% +one of the biggest approximations here + + + align:start position:0% +one of the biggest approximations here +and go from what's called the neutron + + align:start position:0% +and go from what's called the neutron + + + align:start position:0% +and go from what's called the neutron +transport equation which is a fully + + align:start position:0% +transport equation which is a fully + + + align:start position:0% +transport equation which is a fully +accurate physical model of what's really + + align:start position:0% +accurate physical model of what's really + + + align:start position:0% +accurate physical model of what's really +going on to the neutron diffusion + + align:start position:0% +going on to the neutron diffusion + + + align:start position:0% +going on to the neutron diffusion +equation and this is where it gets + + align:start position:0% +equation and this is where it gets + + + align:start position:0% +equation and this is where it gets +really fun you don't assume that + + align:start position:0% +really fun you don't assume that + + + align:start position:0% +really fun you don't assume that +neutrons are subatomic particles that + + align:start position:0% +neutrons are subatomic particles that + + + align:start position:0% +neutrons are subatomic particles that +are whizzing about and knocking off of + + align:start position:0% +are whizzing about and knocking off of + + + align:start position:0% +are whizzing about and knocking off of +everything else you then treat the + + align:start position:0% +everything else you then treat the + + + align:start position:0% +everything else you then treat the +neutrons kind of like a gas or like a + + align:start position:0% +neutrons kind of like a gas or like a + + + align:start position:0% +neutrons kind of like a gas or like a +chemical and you just say that it + + align:start position:0% +chemical and you just say that it + + + align:start position:0% +chemical and you just say that it +follows the laws of diffusion again this + + align:start position:0% +follows the laws of diffusion again this + + + align:start position:0% +follows the laws of diffusion again this +works out very well except for places + + align:start position:0% +works out very well except for places + + + align:start position:0% +works out very well except for places +where cross sections suddenly change + + align:start position:0% +where cross sections suddenly change + + + align:start position:0% +where cross sections suddenly change +like near control rods or near fuel but + + align:start position:0% +like near control rods or near fuel but + + + align:start position:0% +like near control rods or near fuel but +for most of the reactor especially if we + + align:start position:0% +for most of the reactor especially if we + + + align:start position:0% +for most of the reactor especially if we +have a molten salt fuel reactor we can + + align:start position:0% +have a molten salt fuel reactor we can + + + align:start position:0% +have a molten salt fuel reactor we can +invoke what's called ficks law this + + align:start position:0% +invoke what's called ficks law this + + + align:start position:0% +invoke what's called ficks law this +sound familiar to anyone ficks law of + + align:start position:0% +sound familiar to anyone ficks law of + + + align:start position:0% +sound familiar to anyone ficks law of +diffusion three or nine one or five + + align:start position:0% +diffusion three or nine one or five + + + align:start position:0% +diffusion three or nine one or five +eleven one it's it is that it's the + + align:start position:0% +eleven one it's it is that it's the + + + align:start position:0% +eleven one it's it is that it's the +change of a chemical on down a density + + align:start position:0% +change of a chemical on down a density + + + align:start position:0% +change of a chemical on down a density +or concentration gradient so yeah you've + + align:start position:0% +or concentration gradient so yeah you've + + + align:start position:0% +or concentration gradient so yeah you've +got the idea what ficks law says is that + + align:start position:0% +got the idea what ficks law says is that + + + align:start position:0% +got the idea what ficks law says is that +the current or let's say the diffusion + + align:start position:0% +the current or let's say the diffusion + + + align:start position:0% +the current or let's say the diffusion +current or the Neutron current is going + + align:start position:0% +current or the Neutron current is going + + + align:start position:0% +current or the Neutron current is going +to be equal to some diffusion + + align:start position:0% +to be equal to some diffusion + + + align:start position:0% +to be equal to some diffusion +coefficient times the gradient of + + align:start position:0% +coefficient times the gradient of + + + align:start position:0% +coefficient times the gradient of +whatever a chemical concentration you've + + align:start position:0% +whatever a chemical concentration you've + + + align:start position:0% +whatever a chemical concentration you've +got let me put the C in there so right + + align:start position:0% +got let me put the C in there so right + + + align:start position:0% +got let me put the C in there so right +here this would be the current I'll + + align:start position:0% +here this would be the current I'll + + + align:start position:0% +here this would be the current I'll +label in a different color + + align:start position:0% + + + + align:start position:0% + +this would be your variable of interest + + align:start position:0% +this would be your variable of interest + + + align:start position:0% +this would be your variable of interest +maybe C is for concentration or Phi is + + align:start position:0% +maybe C is for concentration or Phi is + + + align:start position:0% +maybe C is for concentration or Phi is +for flux oh that reminds me where are + + align:start position:0% +for flux oh that reminds me where are + + + align:start position:0% +for flux oh that reminds me where are +those bars on our flux which term did we + + align:start position:0% +those bars on our flux which term did we + + + align:start position:0% +those bars on our flux which term did we +do energy whereas my slightly + + align:start position:0% +do energy whereas my slightly + + + align:start position:0% +do energy whereas my slightly +blue over here all of these Phi's become + + align:start position:0% +blue over here all of these Phi's become + + + align:start position:0% +blue over here all of these Phi's become +Capitol because we've gotten rid of all + + align:start position:0% +Capitol because we've gotten rid of all + + + align:start position:0% +Capitol because we've gotten rid of all +the angular and energy in everything + + align:start position:0% +the angular and energy in everything + + + align:start position:0% +the angular and energy in everything +dependence Oh angular dependence neglect + + align:start position:0% +dependence Oh angular dependence neglect + + + align:start position:0% +dependence Oh angular dependence neglect +Omega that should be dark blue mega goes + + align:start position:0% +Omega that should be dark blue mega goes + + + align:start position:0% +Omega that should be dark blue mega goes +away + + align:start position:0% +away + + + align:start position:0% +away +and the flux has become capital so many + + align:start position:0% +and the flux has become capital so many + + + align:start position:0% +and the flux has become capital so many +terms to keep track of luckily you will + + align:start position:0% +terms to keep track of luckily you will + + + align:start position:0% +terms to keep track of luckily you will +never have to and then the J becomes a + + align:start position:0% +never have to and then the J becomes a + + + align:start position:0% +never have to and then the J becomes a +capital J miss any Phi's here no because + + align:start position:0% +capital J miss any Phi's here no because + + + align:start position:0% +capital J miss any Phi's here no because +that one was already gone cool alright + + align:start position:0% +that one was already gone cool alright + + + align:start position:0% +that one was already gone cool alright +so we can use ficks law and transform + + align:start position:0% +so we can use ficks law and transform + + + align:start position:0% +so we can use ficks law and transform +the current into something related to + + align:start position:0% +the current into something related to + + + align:start position:0% +the current into something related to +flux and what we're saying here is that + + align:start position:0% +flux and what we're saying here is that + + + align:start position:0% +flux and what we're saying here is that +we're getting rid of the true physics + + align:start position:0% +we're getting rid of the true physics + + + align:start position:0% +we're getting rid of the true physics +which is that there's some fixed Neutron + + align:start position:0% +which is that there's some fixed Neutron + + + align:start position:0% +which is that there's some fixed Neutron +current and we're saying that neutrons + + align:start position:0% +current and we're saying that neutrons + + + align:start position:0% +current and we're saying that neutrons +behave kind of like a gas or a chemical + + align:start position:0% +behave kind of like a gas or a chemical + + + align:start position:0% +behave kind of like a gas or a chemical +in solution and so in yellow we can + + align:start position:0% +in solution and so in yellow we can + + + align:start position:0% +in solution and so in yellow we can +ditch our current related term and + + align:start position:0% +ditch our current related term and + + + align:start position:0% +ditch our current related term and +rewrite it we don't have any integrals + + align:start position:0% +rewrite it we don't have any integrals + + + align:start position:0% +rewrite it we don't have any integrals +left as negative del squared Phi I think + + align:start position:0% +left as negative del squared Phi I think + + + align:start position:0% +left as negative del squared Phi I think +the only variable left is our not too + + align:start position:0% +the only variable left is our not too + + + align:start position:0% +the only variable left is our not too +bad now we have a second order linear + + align:start position:0% +bad now we have a second order linear + + + align:start position:0% +bad now we have a second order linear +differential equation describing the + + align:start position:0% +differential equation describing the + + + align:start position:0% +differential equation describing the +flow of neutrons in this system it's we + + align:start position:0% +flow of neutrons in this system it's we + + + align:start position:0% +flow of neutrons in this system it's we +actually have something that we can + + align:start position:0% +actually have something that we can + + + align:start position:0% +actually have something that we can +solve for flux I think it's time to + + align:start position:0% +solve for flux I think it's time to + + + align:start position:0% +solve for flux I think it's time to +rewrite it wouldn't you say this has + + align:start position:0% +rewrite it wouldn't you say this has + + + align:start position:0% +rewrite it wouldn't you say this has +been fun so + + align:start position:0% + + + + align:start position:0% + +let's rewrite what's left actually see + + align:start position:0% +let's rewrite what's left actually see + + + align:start position:0% +let's rewrite what's left actually see +everything there will write it in boring + + align:start position:0% +everything there will write it in boring + + + align:start position:0% +everything there will write it in boring +old white so we have no transient + + align:start position:0% +old white so we have no transient + + + align:start position:0% +old white so we have no transient +dependence and we have left Sigma + + align:start position:0% +dependence and we have left Sigma + + + align:start position:0% +dependence and we have left Sigma +fission times flux as a function of our + + align:start position:0% +fission times flux as a function of our + + + align:start position:0% +fission times flux as a function of our +no source and we have our Neutron and I + + align:start position:0% +no source and we have our Neutron and I + + + align:start position:0% +no source and we have our Neutron and I +n reactions of oh we forgot our new + + align:start position:0% +n reactions of oh we forgot our new + + + align:start position:0% +n reactions of oh we forgot our new +Sigma fission then we have our I Sigma + + align:start position:0% +Sigma fission then we have our I Sigma + + + align:start position:0% +Sigma fission then we have our I Sigma +fission from n I n times flux next term + + align:start position:0% +fission from n I n times flux next term + + + align:start position:0% +fission from n I n times flux next term +we have photo fission so we have a new + + align:start position:0% +we have photo fission so we have a new + + + align:start position:0% +we have photo fission so we have a new +from gamma rays times Sigma fission from + + align:start position:0% +from gamma rays times Sigma fission from + + + align:start position:0% +from gamma rays times Sigma fission from +gamma rays times flux next up we have + + align:start position:0% +gamma rays times flux next up we have + + + align:start position:0% +gamma rays times flux next up we have +well last last simplification to make we + + align:start position:0% +well last last simplification to make we + + + align:start position:0% +well last last simplification to make we +have scattering and we have total + + align:start position:0% +have scattering and we have total + + + align:start position:0% +have scattering and we have total +cross-section when we said forget about + + align:start position:0% +cross-section when we said forget about + + + align:start position:0% +cross-section when we said forget about +energy and our scattering kernel becomes + + align:start position:0% +energy and our scattering kernel becomes + + + align:start position:0% +energy and our scattering kernel becomes +one and that's light blue gonna make one + + align:start position:0% +one and that's light blue gonna make one + + + align:start position:0% +one and that's light blue gonna make one +more modification to this board do we + + align:start position:0% +more modification to this board do we + + + align:start position:0% +more modification to this board do we +care about scattering at all anymore + + align:start position:0% +care about scattering at all anymore + + + align:start position:0% +care about scattering at all anymore +whatsoever because scattering doesn't + + align:start position:0% +whatsoever because scattering doesn't + + + align:start position:0% +whatsoever because scattering doesn't +change the number of neutrons left so we + + align:start position:0% +change the number of neutrons left so we + + + align:start position:0% +change the number of neutrons left so we +can then take these two terms and just + + align:start position:0% +can then take these two terms and just + + + align:start position:0% +can then take these two terms and just +call it Sigma absorption times flux + + align:start position:0% + + + + align:start position:0% + +because if we take scattering minus the + + align:start position:0% +because if we take scattering minus the + + + align:start position:0% +because if we take scattering minus the +total cross-section it's like saying all + + align:start position:0% +total cross-section it's like saying all + + + align:start position:0% +total cross-section it's like saying all +that's left if you don't scatter is you + + align:start position:0% +that's left if you don't scatter is you + + + align:start position:0% +that's left if you don't scatter is you +absorb and if you remember all add to + + align:start position:0% +absorb and if you remember all add to + + + align:start position:0% +absorb and if you remember all add to +the energy pile we said that our total + + align:start position:0% +the energy pile we said that our total + + + align:start position:0% +the energy pile we said that our total +cross-section is scattering plus + + align:start position:0% +cross-section is scattering plus + + + align:start position:0% +cross-section is scattering plus +absorption and absorption could be + + align:start position:0% +absorption and absorption could be + + + align:start position:0% +absorption and absorption could be +vision and capture and capture could be + + align:start position:0% +vision and capture and capture could be + + + align:start position:0% +vision and capture and capture could be +lets say capture with nothing happens + + align:start position:0% +lets say capture with nothing happens + + + align:start position:0% +lets say capture with nothing happens +Plus these end I and reactions plus any + + align:start position:0% +Plus these end I and reactions plus any + + + align:start position:0% +Plus these end I and reactions plus any +other capture reaction that does + + align:start position:0% +other capture reaction that does + + + align:start position:0% +other capture reaction that does +something so we're going to use this + + align:start position:0% +something so we're going to use this + + + align:start position:0% +something so we're going to use this +cross section identity right here with a + + align:start position:0% +cross section identity right here with a + + + align:start position:0% +cross section identity right here with a +couple of minus signs on it and say well + + align:start position:0% +couple of minus signs on it and say well + + + align:start position:0% +couple of minus signs on it and say well +scattering minus total leaves you with + + align:start position:0% + + + + align:start position:0% + +negative absorption to simplify terms + + align:start position:0% + + + + align:start position:0% + +I'll leave that up there for everyone to + + align:start position:0% +I'll leave that up there for everyone to + + + align:start position:0% +I'll leave that up there for everyone to +see so then we have scattering and total + + align:start position:0% +see so then we have scattering and total + + + align:start position:0% +see so then we have scattering and total +just becomes minus Sigma absorption + + align:start position:0% +just becomes minus Sigma absorption + + + align:start position:0% +just becomes minus Sigma absorption +times Phi of R and we're left with what + + align:start position:0% +times Phi of R and we're left with what + + + align:start position:0% +times Phi of R and we're left with what +was that current that becomes plus + + align:start position:0% + + + + align:start position:0% + +there's Adi missing in there isn't there + + align:start position:0% +there's Adi missing in there isn't there + + + align:start position:0% +there's Adi missing in there isn't there +a yellow D minus D okay and that's it + + align:start position:0% +a yellow D minus D okay and that's it + + + align:start position:0% +a yellow D minus D okay and that's it +yes + + align:start position:0% +yes + + + align:start position:0% +yes +D is the diffusion coefficient right + + align:start position:0% +D is the diffusion coefficient right + + + align:start position:0% +D is the diffusion coefficient right +here so we're assuming that neutrons + + align:start position:0% +here so we're assuming that neutrons + + + align:start position:0% +here so we're assuming that neutrons +diffused like a gas or a chemical with + + align:start position:0% +diffused like a gas or a chemical with + + + align:start position:0% +diffused like a gas or a chemical with +some diffusion coefficient and so we'll + + align:start position:0% +some diffusion coefficient and so we'll + + + align:start position:0% +some diffusion coefficient and so we'll +define what that is Oh probably next + + align:start position:0% +define what that is Oh probably next + + + align:start position:0% +define what that is Oh probably next +class because we have seven minutes yeah + + align:start position:0% +class because we have seven minutes yeah + + + align:start position:0% +class because we have seven minutes yeah +Luke + + align:start position:0% +Luke + + + align:start position:0% +Luke +uh-huh the see right here that's + + align:start position:0% +uh-huh the see right here that's + + + align:start position:0% +uh-huh the see right here that's +whatever variable we're tracking so + + align:start position:0% +whatever variable we're tracking so + + + align:start position:0% +whatever variable we're tracking so +let's call that flux or let's call it an + + align:start position:0% +let's call that flux or let's call it an + + + align:start position:0% +let's call that flux or let's call it an +the number of neutrons because flux is + + align:start position:0% +the number of neutrons because flux is + + + align:start position:0% +the number of neutrons because flux is +just number of neutrons times velocity + + align:start position:0% +just number of neutrons times velocity + + + align:start position:0% +just number of neutrons times velocity +so let's say that the concentration was + + align:start position:0% +so let's say that the concentration was + + + align:start position:0% +so let's say that the concentration was +the concentration of neutrons and we + + align:start position:0% +the concentration of neutrons and we + + + align:start position:0% +the concentration of neutrons and we +just multiplied by their velocity to get + + align:start position:0% +just multiplied by their velocity to get + + + align:start position:0% +just multiplied by their velocity to get +flux so it's almost like we can say that + + align:start position:0% +flux so it's almost like we can say that + + + align:start position:0% +flux so it's almost like we can say that +the concentration of neutrons is + + align:start position:0% +the concentration of neutrons is + + + align:start position:0% +the concentration of neutrons is +directly related to the flux and that + + align:start position:0% +directly related to the flux and that + + + align:start position:0% +directly related to the flux and that +way we have everything in flux and + + align:start position:0% +way we have everything in flux and + + + align:start position:0% +way we have everything in flux and +that's the entire Neutron diffusion + + align:start position:0% +that's the entire Neutron diffusion + + + align:start position:0% +that's the entire Neutron diffusion +equation yep this is for one group with + + align:start position:0% +equation yep this is for one group with + + + align:start position:0% +equation yep this is for one group with +all the assumptions we made right here + + align:start position:0% + + + + align:start position:0% + +homogeneous what other assumptions did + + align:start position:0% +homogeneous what other assumptions did + + + align:start position:0% +homogeneous what other assumptions did +we make steady state and we already + + align:start position:0% +we make steady state and we already + + + align:start position:0% +we make steady state and we already +neglected that and I think that's enough + + align:start position:0% +neglected that and I think that's enough + + + align:start position:0% +neglected that and I think that's enough +qualifiers for this but it's directly + + align:start position:0% +qualifiers for this but it's directly + + + align:start position:0% +qualifiers for this but it's directly +from this equation right here that we + + align:start position:0% +from this equation right here that we + + + align:start position:0% +from this equation right here that we +can develop what's called our + + align:start position:0% +can develop what's called our + + + align:start position:0% +can develop what's called our +criticality condition under what + + align:start position:0% +criticality condition under what + + + align:start position:0% +criticality condition under what +conditions is the reactor critical so + + align:start position:0% +conditions is the reactor critical so + + + align:start position:0% +conditions is the reactor critical so +then in this case by critical we're + + align:start position:0% +then in this case by critical we're + + + align:start position:0% +then in this case by critical we're +gonna have some variable called K + + align:start position:0% +gonna have some variable called K + + + align:start position:0% +gonna have some variable called K +effective which defines whether that's + + align:start position:0% +effective which defines whether that's + + + align:start position:0% +effective which defines whether that's +defines the number of neutrons produced + + align:start position:0% +defines the number of neutrons produced + + + align:start position:0% +defines the number of neutrons produced +over the number of neutrons consumed and + + align:start position:0% +over the number of neutrons consumed and + + + align:start position:0% +over the number of neutrons consumed and +if K effective equals 1 then we say that + + align:start position:0% +if K effective equals 1 then we say that + + + align:start position:0% +if K effective equals 1 then we say that +the reactor is critical that means that + + align:start position:0% +the reactor is critical that means that + + + align:start position:0% +the reactor is critical that means that +exactly the number of neutrons produced + + align:start position:0% +exactly the number of neutrons produced + + + align:start position:0% +exactly the number of neutrons produced +by regular fission ni n reactions and + + align:start position:0% +by regular fission ni n reactions and + + + align:start position:0% +by regular fission ni n reactions and +photo fission equals exactly the number + + align:start position:0% +photo fission equals exactly the number + + + align:start position:0% +photo fission equals exactly the number +of neutrons absorbed in the anything and + + align:start position:0% +of neutrons absorbed in the anything and + + + align:start position:0% +of neutrons absorbed in the anything and +that leaked out + + align:start position:0% +that leaked out + + + align:start position:0% +that leaked out +so let's relabeled our terms in the same + + align:start position:0% +so let's relabeled our terms in the same + + + align:start position:0% +so let's relabeled our terms in the same +font that we did here so this would be + + align:start position:0% +font that we did here so this would be + + + align:start position:0% +font that we did here so this would be +the fission term this would be n i n + + align:start position:0% +the fission term this would be n i n + + + align:start position:0% +the fission term this would be n i n +reactions + + align:start position:0% +reactions + + + align:start position:0% +reactions +this would be photo fission this would + + align:start position:0% +this would be photo fission this would + + + align:start position:0% +this would be photo fission this would +be absorption this would be leakage how + + align:start position:0% +be absorption this would be leakage how + + + align:start position:0% +be absorption this would be leakage how +many neutrons get out of our finite + + align:start position:0% +many neutrons get out of our finite + + + align:start position:0% +many neutrons get out of our finite +boundary and if you remember when we + + align:start position:0% +boundary and if you remember when we + + + align:start position:0% +boundary and if you remember when we +started out we said we're gonna make the + + align:start position:0% +started out we said we're gonna make the + + + align:start position:0% +started out we said we're gonna make the +neutron balance equation equal to gains + + align:start position:0% +neutron balance equation equal to gains + + + align:start position:0% +neutron balance equation equal to gains +minus losses and through our rainbow + + align:start position:0% +minus losses and through our rainbow + + + align:start position:0% +minus losses and through our rainbow +explosion simplification we've done + + align:start position:0% +explosion simplification we've done + + + align:start position:0% +explosion simplification we've done +exactly that these are your gains these + + align:start position:0% +exactly that these are your gains these + + + align:start position:0% +exactly that these are your gains these +are your losses when gains minus losses + + align:start position:0% +are your losses when gains minus losses + + + align:start position:0% +are your losses when gains minus losses +equals zero the reactors in perfect + + align:start position:0% +equals zero the reactors in perfect + + + align:start position:0% +equals zero the reactors in perfect +balance yep leakage comes out to be + + align:start position:0% +balance yep leakage comes out to be + + + align:start position:0% +balance yep leakage comes out to be +negative + + align:start position:0% +negative + + + align:start position:0% +negative +despite the plus sign here and that's + + align:start position:0% +despite the plus sign here and that's + + + align:start position:0% +despite the plus sign here and that's +actually intentional + + align:start position:0% +actually intentional + + + align:start position:0% +actually intentional +that's because neutrons travel down the + + align:start position:0% +that's because neutrons travel down the + + + align:start position:0% +that's because neutrons travel down the +concentration gradient so let's say + + align:start position:0% +concentration gradient so let's say + + + align:start position:0% +concentration gradient so let's say +we're gonna draw an imaginary flux + + align:start position:0% +we're gonna draw an imaginary flux + + + align:start position:0% +we're gonna draw an imaginary flux +spectrum that's gonna be quite correct + + align:start position:0% +spectrum that's gonna be quite correct + + + align:start position:0% +spectrum that's gonna be quite correct +and I'm doing all of those features for + + align:start position:0% +and I'm doing all of those features for + + + align:start position:0% +and I'm doing all of those features for +a reason but let's look at the + + align:start position:0% +a reason but let's look at the + + + align:start position:0% +a reason but let's look at the +concentration gradient right here + + align:start position:0% +concentration gradient right here + + + align:start position:0% +concentration gradient right here +leakage is positive when your flux + + align:start position:0% +leakage is positive when your flux + + + align:start position:0% +leakage is positive when your flux +gradient is negative that's why the sign + + align:start position:0% +gradient is negative that's why the sign + + + align:start position:0% +gradient is negative that's why the sign +is flipped right there so a positive + + align:start position:0% +is flipped right there so a positive + + + align:start position:0% +is flipped right there so a positive +diffusion term means you have neutrons + + align:start position:0% +diffusion term means you have neutrons + + + align:start position:0% +diffusion term means you have neutrons +leaking out down a negative + + align:start position:0% +leaking out down a negative + + + align:start position:0% +leaking out down a negative +concentration gradient because if you + + align:start position:0% +concentration gradient because if you + + + align:start position:0% +concentration gradient because if you +look at the slope here the change in X + + align:start position:0% +look at the slope here the change in X + + + align:start position:0% +look at the slope here the change in X +is positive and the change in flux is + + align:start position:0% +is positive and the change in flux is + + + align:start position:0% +is positive and the change in flux is +negative so the slope is negative + + align:start position:0% +negative so the slope is negative + + + align:start position:0% +negative so the slope is negative +concentration gradients negative that's + + align:start position:0% +concentration gradients negative that's + + + align:start position:0% +concentration gradients negative that's +why the sign is the opposite of what you + + align:start position:0% +why the sign is the opposite of what you + + + align:start position:0% +why the sign is the opposite of what you +may expect and the same thing goes for + + align:start position:0% +may expect and the same thing goes for + + + align:start position:0% +may expect and the same thing goes for +chemical or gaseous or any other kind of + + align:start position:0% +chemical or gaseous or any other kind of + + + align:start position:0% +chemical or gaseous or any other kind of +diffusion that's come glad you asked + + align:start position:0% +diffusion that's come glad you asked + + + align:start position:0% +diffusion that's come glad you asked +because that's always a point of + + align:start position:0% +because that's always a point of + + + align:start position:0% +because that's always a point of +confusion is why is there that plus sign + + align:start position:0% +confusion is why is there that plus sign + + + align:start position:0% +confusion is why is there that plus sign +that's intentional and that's correct + + align:start position:0% +that's intentional and that's correct + + + align:start position:0% +that's intentional and that's correct +cool so it's in yeah Sean + + align:start position:0% +cool so it's in yeah Sean + + + align:start position:0% +cool so it's in yeah Sean +in that case if you really explicitly + + align:start position:0% +in that case if you really explicitly + + + align:start position:0% +in that case if you really explicitly +write our losses would it be - + + align:start position:0% +write our losses would it be - + + + align:start position:0% +write our losses would it be - +absorption let's put some parentheses on + + align:start position:0% +absorption let's put some parentheses on + + + align:start position:0% +absorption let's put some parentheses on +here equals zero and a minus and when we + + align:start position:0% +here equals zero and a minus and when we + + + align:start position:0% +here equals zero and a minus and when we +say plus leakage we have that plus sign + + align:start position:0% +say plus leakage we have that plus sign + + + align:start position:0% +say plus leakage we have that plus sign +in there so I'm not gonna put any + + align:start position:0% +in there so I'm not gonna put any + + + align:start position:0% +in there so I'm not gonna put any +parentheses up here because that + + align:start position:0% +parentheses up here because that + + + align:start position:0% +parentheses up here because that +wouldn't be correct but what I can say + + align:start position:0% +wouldn't be correct but what I can say + + + align:start position:0% +wouldn't be correct but what I can say +is that gains minus losses have to be in + + align:start position:0% +is that gains minus losses have to be in + + + align:start position:0% +is that gains minus losses have to be in +perfect balance to have a K effective + + align:start position:0% +perfect balance to have a K effective + + + align:start position:0% +perfect balance to have a K effective +equal to one anyone else have any + + align:start position:0% +equal to one anyone else have any + + + align:start position:0% +equal to one anyone else have any +questions before I continue the + + align:start position:0% +questions before I continue the + + + align:start position:0% +questions before I continue the +explanation cool let's say you're + + align:start position:0% +explanation cool let's say you're + + + align:start position:0% +explanation cool let's say you're +producing more neutrons than you're + + align:start position:0% +producing more neutrons than you're + + + align:start position:0% +producing more neutrons than you're +destroying that's what we call + + align:start position:0% +destroying that's what we call + + + align:start position:0% +destroying that's what we call +supercritical so I just did an interview + + align:start position:0% +supercritical so I just did an interview + + + align:start position:0% +supercritical so I just did an interview +for this K through 12 outreach program + + align:start position:0% +for this K through 12 outreach program + + + align:start position:0% +for this K through 12 outreach program +and they said should be people be afraid + + align:start position:0% +and they said should be people be afraid + + + align:start position:0% +and they said should be people be afraid +when something quote-unquote goes + + align:start position:0% +when something quote-unquote goes + + + align:start position:0% +when something quote-unquote goes +critical + + align:start position:0% +critical + + + align:start position:0% +critical +sounds scary emotionally right and the + + align:start position:0% +sounds scary emotionally right and the + + + align:start position:0% +sounds scary emotionally right and the +answer is absolutely not if your reactor + + align:start position:0% +answer is absolutely not if your reactor + + + align:start position:0% +answer is absolutely not if your reactor +goes critical it's turned on and it's in + + align:start position:0% +goes critical it's turned on and it's in + + + align:start position:0% +goes critical it's turned on and it's in +perfect balance that's exactly what you + + align:start position:0% +perfect balance that's exactly what you + + + align:start position:0% +perfect balance that's exactly what you +want so going critical is not a scary + + align:start position:0% +want so going critical is not a scary + + + align:start position:0% +want so going critical is not a scary +thing it means we have control if + + align:start position:0% +thing it means we have control if + + + align:start position:0% +thing it means we have control if +something goes supercritical it doesn't + + align:start position:0% +something goes supercritical it doesn't + + + align:start position:0% +something goes supercritical it doesn't +necessarily mean it's out of control + + align:start position:0% +necessarily mean it's out of control + + + align:start position:0% +necessarily mean it's out of control +reactors can be very slightly + + align:start position:0% +reactors can be very slightly + + + align:start position:0% +reactors can be very slightly +supercritical and still in control + + align:start position:0% +supercritical and still in control + + + align:start position:0% +supercritical and still in control +because of what's called delayed + + align:start position:0% +because of what's called delayed + + + align:start position:0% +because of what's called delayed +neutrons which I will not introduce + + align:start position:0% +neutrons which I will not introduce + + + align:start position:0% +neutrons which I will not introduce +today because we have two minutes if a + + align:start position:0% +today because we have two minutes if a + + + align:start position:0% +today because we have two minutes if a +reactor has a K effective of less than 1 + + align:start position:0% +reactor has a K effective of less than 1 + + + align:start position:0% +reactor has a K effective of less than 1 +we call that subcritical so it's + + align:start position:0% +we call that subcritical so it's + + + align:start position:0% +we call that subcritical so it's +important to note that the the nuclear + + align:start position:0% +important to note that the the nuclear + + + align:start position:0% +important to note that the the nuclear +terminology that's kind of leaked out + + align:start position:0% +terminology that's kind of leaked out + + + align:start position:0% +terminology that's kind of leaked out +into our vernacular is not physically + + align:start position:0% +into our vernacular is not physically + + + align:start position:0% +into our vernacular is not physically +correct in the way that it's used words + + align:start position:0% +correct in the way that it's used words + + + align:start position:0% +correct in the way that it's used words +like critical or me are used to incite + + align:start position:0% +like critical or me are used to incite + + + align:start position:0% +like critical or me are used to incite +emotions and bring about fear when to a + + align:start position:0% +emotions and bring about fear when to a + + + align:start position:0% +emotions and bring about fear when to a +nuclear engineer critical means in + + align:start position:0% +nuclear engineer critical means in + + + align:start position:0% +nuclear engineer critical means in +perfect control in balance like you + + align:start position:0% +perfect control in balance like you + + + align:start position:0% +perfect control in balance like you +would expect are in equilibrium that all + + align:start position:0% +would expect are in equilibrium that all + + + align:start position:0% +would expect are in equilibrium that all +sounds kind of nice makes you calm down + + align:start position:0% +sounds kind of nice makes you calm down + + + align:start position:0% +sounds kind of nice makes you calm down +a little bit yeah so we can put one last + + align:start position:0% +a little bit yeah so we can put one last + + + align:start position:0% +a little bit yeah so we can put one last +term in front of our criticality + + align:start position:0% +term in front of our criticality + + + align:start position:0% +term in front of our criticality +condition we can take either the gains + + align:start position:0% +condition we can take either the gains + + + align:start position:0% +condition we can take either the gains +or the losses move the equal sign and + + align:start position:0% +or the losses move the equal sign and + + + align:start position:0% +or the losses move the equal sign and +zero over a little bit + + align:start position:0% +zero over a little bit + + + align:start position:0% +zero over a little bit +and put a 1 over K effective here this + + align:start position:0% +and put a 1 over K effective here this + + + align:start position:0% +and put a 1 over K effective here this +then perfectly describes the difference + + align:start position:0% +then perfectly describes the difference + + + align:start position:0% +then perfectly describes the difference +between the gains and the losses in a + + align:start position:0% +between the gains and the losses in a + + + align:start position:0% +between the gains and the losses in a +reactor so if the gains equal the losses + + align:start position:0% +reactor so if the gains equal the losses + + + align:start position:0% +reactor so if the gains equal the losses +then k effective must equal 1 and the + + align:start position:0% +then k effective must equal 1 and the + + + align:start position:0% +then k effective must equal 1 and the +reactor has got to be in balance if + + align:start position:0% +reactor has got to be in balance if + + + align:start position:0% +reactor has got to be in balance if +there are more gains than losses which + + align:start position:0% +there are more gains than losses which + + + align:start position:0% +there are more gains than losses which +means if you are producing more neutrons + + align:start position:0% +means if you are producing more neutrons + + + align:start position:0% +means if you are producing more neutrons +than you're consuming then k effective + + align:start position:0% +than you're consuming then k effective + + + align:start position:0% +than you're consuming then k effective +must be greater than 1 for this equation + + align:start position:0% +must be greater than 1 for this equation + + + align:start position:0% +must be greater than 1 for this equation +to still equal zero because this + + align:start position:0% +to still equal zero because this + + + align:start position:0% +to still equal zero because this +equation must be satisfied so if you're + + align:start position:0% +equation must be satisfied so if you're + + + align:start position:0% +equation must be satisfied so if you're +making more neutrons your k effectives + + align:start position:0% +making more neutrons your k effectives + + + align:start position:0% +making more neutrons your k effectives +got to be greater than 1 so you have a + + align:start position:0% +got to be greater than 1 so you have a + + + align:start position:0% +got to be greater than 1 so you have a +less than 1 multiplier in front and on + + align:start position:0% +less than 1 multiplier in front and on + + + align:start position:0% +less than 1 multiplier in front and on +the opposite side if you're losing more + + align:start position:0% +the opposite side if you're losing more + + + align:start position:0% +the opposite side if you're losing more +neutrons than you're gaining your K + + align:start position:0% +neutrons than you're gaining your K + + + align:start position:0% +neutrons than you're gaining your K +effective has to be less than 1 to make + + align:start position:0% +effective has to be less than 1 to make + + + align:start position:0% +effective has to be less than 1 to make +this equation balanced going along with + + align:start position:0% +this equation balanced going along with + + + align:start position:0% +this equation balanced going along with +all these definitions right here so it's + + align:start position:0% +all these definitions right here so it's + + + align:start position:0% +all these definitions right here so it's +exactly 505 of I've given you delivered + + align:start position:0% +exactly 505 of I've given you delivered + + + align:start position:0% +exactly 505 of I've given you delivered +promised blackboard of Lucky Charms and + + align:start position:0% +promised blackboard of Lucky Charms and + + + align:start position:0% +promised blackboard of Lucky Charms and +we've hit perfect spot which is the one + + align:start position:0% +we've hit perfect spot which is the one + + + align:start position:0% +we've hit perfect spot which is the one +group homogeneous steady-state neutron + + align:start position:0% +group homogeneous steady-state neutron + + + align:start position:0% +group homogeneous steady-state neutron +diffusion equation from which we can + + align:start position:0% +diffusion equation from which we can + + + align:start position:0% +diffusion equation from which we can +develop our criticality conditions and + + align:start position:0% +develop our criticality conditions and + + + align:start position:0% +develop our criticality conditions and +solve this much simpler equation to get + + align:start position:0% +solve this much simpler equation to get + + + align:start position:0% +solve this much simpler equation to get +the flux profiles that I've started to + + align:start position:0% +the flux profiles that I've started to + + + align:start position:0% +the flux profiles that I've started to +draw here so I want to stop here and + + align:start position:0% +draw here so I want to stop here and + + + align:start position:0% +draw here so I want to stop here and +take any questions on any of the terms + + align:start position:0% +take any questions on any of the terms + + + align:start position:0% +take any questions on any of the terms +you see here yeah + + align:start position:0% + + + + align:start position:0% + +the disparate energy groups and then + + align:start position:0% +the disparate energy groups and then + + + align:start position:0% +the disparate energy groups and then +when we're doing the one group you're + + align:start position:0% +when we're doing the one group you're + + + align:start position:0% +when we're doing the one group you're +actually just treating sperm one fast + + align:start position:0% +actually just treating sperm one fast + + + align:start position:0% +actually just treating sperm one fast +together we are that's right yep so a + + align:start position:0% +together we are that's right yep so a + + + align:start position:0% +together we are that's right yep so a +lot of reactors at least thermal + + align:start position:0% +lot of reactors at least thermal + + + align:start position:0% +lot of reactors at least thermal +reactors where you only care if neutrons + + align:start position:0% +reactors where you only care if neutrons + + + align:start position:0% +reactors where you only care if neutrons +are thermal or not two groups enough + + align:start position:0% +are thermal or not two groups enough + + + align:start position:0% +are thermal or not two groups enough +when you have a one group or a two group + + align:start position:0% +when you have a one group or a two group + + + align:start position:0% +when you have a one group or a two group +equation these are fairly analytically + + align:start position:0% +equation these are fairly analytically + + + align:start position:0% +equation these are fairly analytically +solvable things and get to any more + + align:start position:0% +solvable things and get to any more + + + align:start position:0% +solvable things and get to any more +groups than that and yes they're + + align:start position:0% +groups than that and yes they're + + + align:start position:0% +groups than that and yes they're +analytically solvable but it gets + + align:start position:0% +analytically solvable but it gets + + + align:start position:0% +analytically solvable but it gets +horrible and that's why we have + + align:start position:0% +horrible and that's why we have + + + align:start position:0% +horrible and that's why we have +computers to do the sorts of repetitive + + align:start position:0% +computers to do the sorts of repetitive + + + align:start position:0% +computers to do the sorts of repetitive +calculations over and over again once + + align:start position:0% +calculations over and over again once + + + align:start position:0% +calculations over and over again once +we've solved the one group equation I'll + + align:start position:0% +we've solved the one group equation I'll + + + align:start position:0% +we've solved the one group equation I'll +then show you intuitive ways to write + + align:start position:0% +then show you intuitive ways to write + + + align:start position:0% +then show you intuitive ways to write +but not solve the equations for multi + + align:start position:0% +but not solve the equations for multi + + + align:start position:0% +but not solve the equations for multi +group equations sure any other questions + + align:start position:0% + + + + align:start position:0% + +so like I promise we didn't stay complex + + align:start position:0% +so like I promise we didn't stay complex + + + align:start position:0% +so like I promise we didn't stay complex +for long because there's basically + + align:start position:0% +for long because there's basically + + + align:start position:0% +for long because there's basically +nothing left yeah oh that's a partial + + align:start position:0% +nothing left yeah oh that's a partial + + + align:start position:0% +nothing left yeah oh that's a partial +derivatives yep that yeah there we go + + align:start position:0% +derivatives yep that yeah there we go + + + align:start position:0% +derivatives yep that yeah there we go +yeah so this is saying a change in + + align:start position:0% +yeah so this is saying a change in + + + align:start position:0% +yeah so this is saying a change in +Neutron population or the partial + + align:start position:0% +Neutron population or the partial + + + align:start position:0% +Neutron population or the partial +derivative of n with respect to T cuz n + + align:start position:0% +derivative of n with respect to T cuz n + + + align:start position:0% +derivative of n with respect to T cuz n +varies with space energy angle time and + + align:start position:0% +varies with space energy angle time and + + + align:start position:0% +varies with space energy angle time and +anything else you could possibly think + + align:start position:0% +anything else you could possibly think + + + align:start position:0% +anything else you could possibly think +about equals the gains minus the losses + + align:start position:0% +about equals the gains minus the losses + + + align:start position:0% +about equals the gains minus the losses +I think this is worthy of a t-shirt if + + align:start position:0% +I think this is worthy of a t-shirt if + + + align:start position:0% +I think this is worthy of a t-shirt if +any of you guys would like to update the + + align:start position:0% +any of you guys would like to update the + + + align:start position:0% +any of you guys would like to update the +department shirts to properly take into + + align:start position:0% +department shirts to properly take into + + + align:start position:0% +department shirts to properly take into +account photo fission external sources + + align:start position:0% +account photo fission external sources + + + align:start position:0% +account photo fission external sources +and ni n reactions I think it would make + + align:start position:0% +and ni n reactions I think it would make + + + align:start position:0% +and ni n reactions I think it would make +for a much more impressive thing because + + align:start position:0% +for a much more impressive thing because + + + align:start position:0% +for a much more impressive thing because +we kind of printed an oversimplification + + align:start position:0% +we kind of printed an oversimplification + + + align:start position:0% +we kind of printed an oversimplification +before it's too bad and we definitely + + align:start position:0% +before it's too bad and we definitely + + + align:start position:0% +before it's too bad and we definitely +had room on the shirt there was like + + align:start position:0% +had room on the shirt there was like + + + align:start position:0% +had room on the shirt there was like +room on the sides and on the sleeves + + align:start position:0% +room on the sides and on the sleeves + + + align:start position:0% +room on the sides and on the sleeves +yeah keep going on that might have to be + + align:start position:0% +yeah keep going on that might have to be + + + align:start position:0% +yeah keep going on that might have to be +long-sleeved I think they'll be pretty + + align:start position:0% +long-sleeved I think they'll be pretty + + + align:start position:0% +long-sleeved I think they'll be pretty +soon yeah okay if no one else has any + + align:start position:0% +soon yeah okay if no one else has any + + + align:start position:0% +soon yeah okay if no one else has any +immediate questions you'll have plenty + + align:start position:0% +immediate questions you'll have plenty + + + align:start position:0% +immediate questions you'll have plenty +of time tomorrow because the whole goal + + align:start position:0% +of time tomorrow because the whole goal + + + align:start position:0% +of time tomorrow because the whole goal +tomorrow is gonna be to solve this + + align:start position:0% +tomorrow is gonna be to solve this + + + align:start position:0% +tomorrow is gonna be to solve this +equation that's only gonna take like 20 + + align:start position:0% +equation that's only gonna take like 20 + + + align:start position:0% +equation that's only gonna take like 20 +minutes so we can do a quick review of + + align:start position:0% +minutes so we can do a quick review of + + + align:start position:0% +minutes so we can do a quick review of +the simplification of the neutron + + align:start position:0% +the simplification of the neutron + + + align:start position:0% +the simplification of the neutron +transport equation solve the neutron + + align:start position:0% +transport equation solve the neutron + + + align:start position:0% +transport equation solve the neutron +diffusion equation if you have questions + + align:start position:0% +diffusion equation if you have questions + + + align:start position:0% +diffusion equation if you have questions +we'll spend time to answer them there + + align:start position:0% +we'll spend time to answer them there + + + align:start position:0% +we'll spend time to answer them there +and if you don't we'll move on to + + align:start position:0% +and if you don't we'll move on to + + + align:start position:0% +and if you don't we'll move on to +writing multi group equations and also + + align:start position:0% +writing multi group equations and also + + + align:start position:0% +writing multi group equations and also +Friday for recitation it's electron + + align:start position:0% +Friday for recitation it's electron + + + align:start position:0% +Friday for recitation it's electron +microscope time so now that you guys + + align:start position:0% +microscope time so now that you guys + + + align:start position:0% +microscope time so now that you guys +have learned different electron + + align:start position:0% +have learned different electron + + + align:start position:0% +have learned different electron +interactions with matter you're going to + + align:start position:0% +interactions with matter you're going to + + + align:start position:0% +interactions with matter you're going to +see them so we're going to be analyzing + + align:start position:0% +see them so we're going to be analyzing + + + align:start position:0% +see them so we're going to be analyzing +a couple of different pieces of + + align:start position:0% +a couple of different pieces of + + + align:start position:0% +a couple of different pieces of +materials that a couple of you are gonna + + align:start position:0% +materials that a couple of you are gonna + + + align:start position:0% +materials that a couple of you are gonna +get to select and we're going to image + + align:start position:0% +get to select and we're going to image + + + align:start position:0% +get to select and we're going to image +them with electrons to show how you can + + align:start position:0% +them with electrons to show how you can + + + align:start position:0% +them with electrons to show how you can +beat the wavelength of light imaging + + align:start position:0% +beat the wavelength of light imaging + + + align:start position:0% +beat the wavelength of light imaging +limit like I told you before we're gonna + + align:start position:0% +limit like I told you before we're gonna + + + align:start position:0% +limit like I told you before we're gonna +produce our own x-ray spectra to analyze + + align:start position:0% +produce our own x-ray spectra to analyze + + + align:start position:0% +produce our own x-ray spectra to analyze +them elementally where you'll see the + + align:start position:0% +them elementally where you'll see the + + + align:start position:0% +them elementally where you'll see the +bremsstrahlung you'll see the + + align:start position:0% +bremsstrahlung you'll see the + + + align:start position:0% +bremsstrahlung you'll see the +characteristic Peaks and you'll see a + + align:start position:0% +characteristic Peaks and you'll see a + + + align:start position:0% +characteristic Peaks and you'll see a +couple of other features that I'll + + align:start position:0% +couple of other features that I'll + + + align:start position:0% +couple of other features that I'll +explain too so get ready for some SEM + + align:start position:0% +explain too so get ready for some SEM + + + align:start position:0% +explain too so get ready for some SEM +tomorrow \ No newline at end of file diff --git a/L8PXcZ2ExiU.txt b/L8PXcZ2ExiU.txt new file mode 100644 index 0000000000000000000000000000000000000000..cb7ae02b6c124893ed810e43c3d640c1a672ef82 --- /dev/null +++ b/L8PXcZ2ExiU.txt @@ -0,0 +1,15307 @@ +align:start position:0% + +today we're going to uh continue we're + + align:start position:0% +today we're going to uh continue we're + + + align:start position:0% +today we're going to uh continue we're +going to talk about a new notion a + + align:start position:0% +going to talk about a new notion a + + + align:start position:0% +going to talk about a new notion a +really really interesting notion in my + + align:start position:0% +really really interesting notion in my + + + align:start position:0% +really really interesting notion in my +opinion uh called probabilistically + + align:start position:0% +opinion uh called probabilistically + + + align:start position:0% +opinion uh called probabilistically +checkable proofs I'll explain what it is + + align:start position:0% +checkable proofs I'll explain what it is + + + align:start position:0% +checkable proofs I'll explain what it is +so we'll we're going to Define this + + align:start position:0% +so we'll we're going to Define this + + + align:start position:0% +so we'll we're going to Define this +notion and we're going to construct it + + align:start position:0% +notion and we're going to construct it + + + align:start position:0% +notion and we're going to construct it +uh from the GK protocol so you'll kind + + align:start position:0% +uh from the GK protocol so you'll kind + + + align:start position:0% +uh from the GK protocol so you'll kind +of see not only the definition but + + align:start position:0% +of see not only the definition but + + + align:start position:0% +of see not only the definition but +you'll be able after this class the hope + + align:start position:0% +you'll be able after this class the hope + + + align:start position:0% +you'll be able after this class the hope +is that you'll be able to construct a + + align:start position:0% +is that you'll be able to construct a + + + align:start position:0% +is that you'll be able to construct a +PCP if you need to construct proof + + align:start position:0% +PCP if you need to construct proof + + + align:start position:0% +PCP if you need to construct proof +you'll be able to do that so that's + + align:start position:0% +you'll be able to do that so that's + + + align:start position:0% +you'll be able to do that so that's +going to be the first part of today's + + align:start position:0% +going to be the first part of today's + + + align:start position:0% +going to be the first part of today's +lecture and the second part of today's + + align:start position:0% +lecture and the second part of today's + + + align:start position:0% +lecture and the second part of today's +lecture is actually going to be the + + align:start position:0% +lecture is actually going to be the + + + align:start position:0% +lecture is actually going to be the +first time we actually use cryptography + + align:start position:0% +first time we actually use cryptography + + + align:start position:0% +first time we actually use cryptography +so so far this class has not been at all + + align:start position:0% +so so far this class has not been at all + + + align:start position:0% +so so far this class has not been at all +about cryptography it was everything was + + align:start position:0% +about cryptography it was everything was + + + align:start position:0% +about cryptography it was everything was +information it was actually complexity + + align:start position:0% +information it was actually complexity + + + align:start position:0% +information it was actually complexity +Theory uh but today is going to be the + + align:start position:0% +Theory uh but today is going to be the + + + align:start position:0% +Theory uh but today is going to be the +first time we're going to move + + align:start position:0% +first time we're going to move + + + align:start position:0% +first time we're going to move +into uh + + align:start position:0% +into uh + + + align:start position:0% +into uh +cryptography and uh as we'll talk we'll + + align:start position:0% +cryptography and uh as we'll talk we'll + + + align:start position:0% +cryptography and uh as we'll talk we'll +see that doing this information + + align:start position:0% +see that doing this information + + + align:start position:0% +see that doing this information +theoretic proofs where you say okay no + + align:start position:0% +theoretic proofs where you say okay no + + + align:start position:0% +theoretic proofs where you say okay no +Pro can create a give you a false proof + + align:start position:0% +Pro can create a give you a false proof + + + align:start position:0% +Pro can create a give you a false proof +that is limiting okay we can do + + align:start position:0% +that is limiting okay we can do + + + align:start position:0% +that is limiting okay we can do +everything we want using that uh a this + + align:start position:0% +everything we want using that uh a this + + + align:start position:0% +everything we want using that uh a this +notion and therefore we're going to go + + align:start position:0% +notion and therefore we're going to go + + + align:start position:0% +notion and therefore we're going to go +into a new notion of soundness which is + + align:start position:0% +into a new notion of soundness which is + + + align:start position:0% +into a new notion of soundness which is +what we call arguments or computational + + align:start position:0% +what we call arguments or computational + + + align:start position:0% +what we call arguments or computational +soundness and we're going to relax the + + align:start position:0% +soundness and we're going to relax the + + + align:start position:0% +soundness and we're going to relax the +prover and say an all Power Pro an all + + align:start position:0% +prover and say an all Power Pro an all + + + align:start position:0% +prover and say an all Power Pro an all +powerful approver may be able to cheat + + align:start position:0% +powerful approver may be able to cheat + + + align:start position:0% +powerful approver may be able to cheat +but the guarantee we give hey Tony is + + align:start position:0% +but the guarantee we give hey Tony is + + + align:start position:0% +but the guarantee we give hey Tony is +that a computationally bounded PR cannot + + align:start position:0% +that a computationally bounded PR cannot + + + align:start position:0% +that a computationally bounded PR cannot +cheat okay that's going to be the + + align:start position:0% +cheat okay that's going to be the + + + align:start position:0% +cheat okay that's going to be the +guarantee we get and we'll see once we + + align:start position:0% +guarantee we get and we'll see once we + + + align:start position:0% +guarantee we get and we'll see once we +relax the soundness requirement to a + + align:start position:0% +relax the soundness requirement to a + + + align:start position:0% +relax the soundness requirement to a +requirement that's only computational + + align:start position:0% +requirement that's only computational + + + align:start position:0% +requirement that's only computational +sound then we'll be able to get a lot + + align:start position:0% +sound then we'll be able to get a lot + + + align:start position:0% +sound then we'll be able to get a lot +more and kind of uh you know the life + + align:start position:0% +more and kind of uh you know the life + + + align:start position:0% +more and kind of uh you know the life +will kind of open for us and we're going + + align:start position:0% +will kind of open for us and we're going + + + align:start position:0% +will kind of open for us and we're going +to have a lot a lot of new uh kind of + + align:start position:0% +to have a lot a lot of new uh kind of + + + align:start position:0% +to have a lot a lot of new uh kind of +constructions and things that we were + + align:start position:0% +constructions and things that we were + + + align:start position:0% +constructions and things that we were +unable to do information + + align:start position:0% +unable to do information + + + align:start position:0% +unable to do information +theoretically so this is uh the plan for + + align:start position:0% +theoretically so this is uh the plan for + + + align:start position:0% +theoretically so this is uh the plan for +today questions before we start I + + align:start position:0% +today questions before we start I + + + align:start position:0% +today questions before we start I +haven't seen you guys in a + + align:start position:0% +haven't seen you guys in a + + + align:start position:0% +haven't seen you guys in a +while so it's good to see you a lot of + + align:start position:0% +while so it's good to see you a lot of + + + align:start position:0% +while so it's good to see you a lot of +things changed since the last time I've + + align:start position:0% +things changed since the last time I've + + + align:start position:0% +things changed since the last time I've +seen you I'm probably going to be a bit + + align:start position:0% +seen you I'm probably going to be a bit + + + align:start position:0% +seen you I'm probably going to be a bit +distracted today so I'm sorry + + align:start position:0% +distracted today so I'm sorry + + + align:start position:0% +distracted today so I'm sorry +okay okay let's start so what are no + + align:start position:0% +okay okay let's start so what are no + + + align:start position:0% +okay okay let's start so what are no +questions okay so let's start with pcps + + align:start position:0% +questions okay so let's start with pcps + + + align:start position:0% +questions okay so let's start with pcps +what are probity checkable proofs + + align:start position:0% +what are probity checkable proofs + + + align:start position:0% +what are probity checkable proofs +so these are the idea of probability + + align:start position:0% +so these are the idea of probability + + + align:start position:0% +so these are the idea of probability +checkable proofs is to take a proof like + + align:start position:0% +checkable proofs is to take a proof like + + + align:start position:0% +checkable proofs is to take a proof like +a classical proof think of NP in NP we + + align:start position:0% +a classical proof think of NP in NP we + + + align:start position:0% +a classical proof think of NP in NP we +have a instance X and A Witness this + + align:start position:0% +have a instance X and A Witness this + + + align:start position:0% +have a instance X and A Witness this +witness is like a proof for X being in + + align:start position:0% +witness is like a proof for X being in + + + align:start position:0% +witness is like a proof for X being in +the + + align:start position:0% +the + + + align:start position:0% +the +language to verify this proof you need + + align:start position:0% +language to verify this proof you need + + + align:start position:0% +language to verify this proof you need +to read the entire thing and do some + + align:start position:0% +to read the entire thing and do some + + + align:start position:0% +to read the entire thing and do some +computation like this verification + + align:start position:0% +computation like this verification + + + align:start position:0% +computation like this verification +circuit you know a that checks that X + + align:start position:0% +circuit you know a that checks that X + + + align:start position:0% +circuit you know a that checks that X +and W is in the relation there's a + + align:start position:0% +and W is in the relation there's a + + + align:start position:0% +and W is in the relation there's a +circuit that checks this + + align:start position:0% +circuit that checks this + + + align:start position:0% +circuit that checks this +okay what is the idea of a probability + + align:start position:0% +okay what is the idea of a probability + + + align:start position:0% +okay what is the idea of a probability +checkable proof the idea here what we + + align:start position:0% +checkable proof the idea here what we + + + align:start position:0% +checkable proof the idea here what we +want is to take this proof and convert + + align:start position:0% +want is to take this proof and convert + + + align:start position:0% +want is to take this proof and convert +it into a new proof it may be larger + + align:start position:0% +it into a new proof it may be larger + + + align:start position:0% +it into a new proof it may be larger +actually than the original proof so + + align:start position:0% +actually than the original proof so + + + align:start position:0% +actually than the original proof so +maybe you know the original proof was of + + align:start position:0% +maybe you know the original proof was of + + + align:start position:0% +maybe you know the original proof was of +size M let's say the instance of size n + + align:start position:0% +size M let's say the instance of size n + + + align:start position:0% +size M let's say the instance of size n +this may be of size much bigger still we + + align:start position:0% +this may be of size much bigger still we + + + align:start position:0% +this may be of size much bigger still we +want it to be polinomial in n& + + align:start position:0% +want it to be polinomial in n& + + + align:start position:0% +want it to be polinomial in n& +M but now so we just made it bigger so + + align:start position:0% +M but now so we just made it bigger so + + + align:start position:0% +M but now so we just made it bigger so +what's what's good about it so what's + + align:start position:0% +what's what's good about it so what's + + + align:start position:0% +what's what's good about it so what's +nice about this proof is the IDE is you + + align:start position:0% +nice about this proof is the IDE is you + + + align:start position:0% +nice about this proof is the IDE is you +don't actually have to read all of it to + + align:start position:0% +don't actually have to read all of it to + + + align:start position:0% +don't actually have to read all of it to +check it and that's weird so the idea + + align:start position:0% +check it and that's weird so the idea + + + align:start position:0% +check it and that's weird so the idea +here yeah the proof may be a little + + align:start position:0% +here yeah the proof may be a little + + + align:start position:0% +here yeah the proof may be a little +longer polom longer but you only need to + + align:start position:0% +longer polom longer but you only need to + + + align:start position:0% +longer polom longer but you only need to +read a few + + align:start position:0% +read a few + + + align:start position:0% +read a few +locations to and to check that it's + + align:start position:0% +locations to and to check that it's + + + align:start position:0% +locations to and to check that it's +valid so to verify often pcps are + + align:start position:0% +valid so to verify often pcps are + + + align:start position:0% +valid so to verify often pcps are +denoted by pi uh to verify PCP proof + + align:start position:0% +denoted by pi uh to verify PCP proof + + + align:start position:0% +denoted by pi uh to verify PCP proof +given X all the verifier needs to do is + + align:start position:0% +given X all the verifier needs to do is + + + align:start position:0% +given X all the verifier needs to do is +query doesn't actually need to read + + align:start position:0% +query doesn't actually need to read + + + align:start position:0% +query doesn't actually need to read +these things he queries a few locations + + align:start position:0% +these things he queries a few locations + + + align:start position:0% +these things he queries a few locations +a few bits checks a few bits of the + + align:start position:0% +a few bits checks a few bits of the + + + align:start position:0% +a few bits checks a few bits of the +proof and then applies a verification + + align:start position:0% +proof and then applies a verification + + + align:start position:0% +proof and then applies a verification +circuit that depends only on these + + align:start position:0% +circuit that depends only on these + + + align:start position:0% +circuit that depends only on these +bits okay and importantly the bits he + + align:start position:0% +bits okay and importantly the bits he + + + align:start position:0% +bits okay and importantly the bits he +chooses are random the the prover + + align:start position:0% +chooses are random the the prover + + + align:start position:0% +chooses are random the the prover +doesn't know otherwise he will it's like + + align:start position:0% +doesn't know otherwise he will it's like + + + align:start position:0% +doesn't know otherwise he will it's like +shrinking if he knew the prover knew oh + + align:start position:0% +shrinking if he knew the prover knew oh + + + align:start position:0% +shrinking if he knew the prover knew oh +the refer is going to only check in bit + + align:start position:0% +the refer is going to only check in bit + + + align:start position:0% +the refer is going to only check in bit +17 22 and 25 then he would just give you + + align:start position:0% +17 22 and 25 then he would just give you + + + align:start position:0% +17 22 and 25 then he would just give you +it's like you'll have a succinct witness + + align:start position:0% +it's like you'll have a succinct witness + + + align:start position:0% +it's like you'll have a succinct witness +and of course we can't take arbitrary + + align:start position:0% +and of course we can't take arbitrary + + + align:start position:0% +and of course we can't take arbitrary +Witnesses and just make them 16 if you + + align:start position:0% +Witnesses and just make them 16 if you + + + align:start position:0% +Witnesses and just make them 16 if you +don't believe that's possible yeah so + + align:start position:0% +don't believe that's possible yeah so + + + align:start position:0% +don't believe that's possible yeah so +it's a PTP then only used for as m is + + align:start position:0% +it's a PTP then only used for as m is + + + align:start position:0% +it's a PTP then only used for as m is +much greater than M okay so the question + + align:start position:0% +much greater than M okay so the question + + + align:start position:0% +much greater than M okay so the question +was is a PCP used if m is much greater + + align:start position:0% +was is a PCP used if m is much greater + + + align:start position:0% +was is a PCP used if m is much greater +than n and the answer is no actually we + + align:start position:0% +than n and the answer is no actually we + + + align:start position:0% +than n and the answer is no actually we +can think of it we can even use it where + + align:start position:0% +can think of it we can even use it where + + + align:start position:0% +can think of it we can even use it where +M the length of w is n to the Epsilon + + align:start position:0% +M the length of w is n to the Epsilon + + + align:start position:0% +M the length of w is n to the Epsilon +okay even less than n to the EPS even n + + align:start position:0% +okay even less than n to the EPS even n + + + align:start position:0% +okay even less than n to the EPS even n +to the little o of n now you this will + + align:start position:0% +to the little o of n now you this will + + + align:start position:0% +to the little o of n now you this will +still be polinomial in N so actually you + + align:start position:0% +still be polinomial in N so actually you + + + align:start position:0% +still be polinomial in N so actually you +you took the proof and make it actually + + align:start position:0% +you took the proof and make it actually + + + align:start position:0% +you took the proof and make it actually +more than polom larger because it's + + align:start position:0% +more than polom larger because it's + + + align:start position:0% +more than polom larger because it's +polinomial an n and M and if the proof + + align:start position:0% +polinomial an n and M and if the proof + + + align:start position:0% +polinomial an n and M and if the proof +here is smaller is n to the little of + + align:start position:0% +here is smaller is n to the little of + + + align:start position:0% +here is smaller is n to the little of +one then this is polyn it's actually + + align:start position:0% +one then this is polyn it's actually + + + align:start position:0% +one then this is polyn it's actually +more than polinomial bigger but so + + align:start position:0% +more than polinomial bigger but so + + + align:start position:0% +more than polinomial bigger but so +you're saying what did we gain we took + + align:start position:0% +you're saying what did we gain we took + + + align:start position:0% +you're saying what did we gain we took +us a short proof made it so much bigger + + align:start position:0% +us a short proof made it so much bigger + + + align:start position:0% +us a short proof made it so much bigger +what did we gain and what we gained is + + align:start position:0% +what did we gain and what we gained is + + + align:start position:0% +what did we gain and what we gained is +the Hope is that you can query this the + + align:start position:0% +the Hope is that you can query this the + + + align:start position:0% +the Hope is that you can query this the +verif can query this in very very few + + align:start position:0% +verif can query this in very very few + + + align:start position:0% +verif can query this in very very few +locations read only very very few bits + + align:start position:0% +locations read only very very few bits + + + align:start position:0% +locations read only very very few bits +of this proof okay okay verifier also + + align:start position:0% +of this proof okay okay verifier also + + + align:start position:0% +of this proof okay okay verifier also +have to Rex that yeah the verifier all + + align:start position:0% +have to Rex that yeah the verifier all + + + align:start position:0% +have to Rex that yeah the verifier all +of so yes good so the question that's a + + align:start position:0% +of so yes good so the question that's a + + + align:start position:0% +of so yes good so the question that's a +good question so the question was does + + align:start position:0% +good question so the question was does + + + align:start position:0% +good question so the question was does +the verifier have to read all of X and + + align:start position:0% +the verifier have to read all of X and + + + align:start position:0% +the verifier have to read all of X and +because I said he only needs to read a + + align:start position:0% +because I said he only needs to read a + + + align:start position:0% +because I said he only needs to read a +few location the proof does he need to + + align:start position:0% +few location the proof does he need to + + + align:start position:0% +few location the proof does he need to +read all of X and a prior of course he + + align:start position:0% +read all of X and a prior of course he + + + align:start position:0% +read all of X and a prior of course he +needs to read all of X because even if + + align:start position:0% +needs to read all of X because even if + + + align:start position:0% +needs to read all of X because even if +there's one bit in X that he doesn't + + align:start position:0% +there's one bit in X that he doesn't + + + align:start position:0% +there's one bit in X that he doesn't +read you know what if that bit is it's + + align:start position:0% +read you know what if that bit is it's + + + align:start position:0% +read you know what if that bit is it's +actually what the state what the + + align:start position:0% +actually what the state what the + + + align:start position:0% +actually what the state what the +sentence is what the statement is you + + align:start position:0% +sentence is what the statement is you + + + align:start position:0% +sentence is what the statement is you +know the Prov need to know what am I + + align:start position:0% +know the Prov need to know what am I + + + align:start position:0% +know the Prov need to know what am I +reading what am I what are you proving + + align:start position:0% +reading what am I what are you proving + + + align:start position:0% +reading what am I what are you proving +to me but there are extensions called + + align:start position:0% +to me but there are extensions called + + + align:start position:0% +to me but there are extensions called +called PCP of proximity which I'm not + + align:start position:0% +called PCP of proximity which I'm not + + + align:start position:0% +called PCP of proximity which I'm not +going to get into in this class where + + align:start position:0% +going to get into in this class where + + + align:start position:0% +going to get into in this class where +actually the verify the verifier also + + align:start position:0% +actually the verify the verifier also + + + align:start position:0% +actually the verify the verifier also +doesn't read all of X but the guarantee + + align:start position:0% +doesn't read all of X but the guarantee + + + align:start position:0% +doesn't read all of X but the guarantee +is not that X is in the language it's + + align:start position:0% +is not that X is in the language it's + + + align:start position:0% +is not that X is in the language it's +the guarantee is that kind of it's a the + + align:start position:0% +the guarantee is that kind of it's a the + + + align:start position:0% +the guarantee is that kind of it's a the +Oracle that is given to the verifier + + align:start position:0% +Oracle that is given to the verifier + + + align:start position:0% +Oracle that is given to the verifier +there is something close to it that's in + + align:start position:0% +there is something close to it that's in + + + align:start position:0% +there is something close to it that's in +the linguage so it there is a notion of + + align:start position:0% +the linguage so it there is a notion of + + + align:start position:0% +the linguage so it there is a notion of +extension of this notion of the PCP + + align:start position:0% +extension of this notion of the PCP + + + align:start position:0% +extension of this notion of the PCP +where the verifier doesn't even need to + + align:start position:0% +where the verifier doesn't even need to + + + align:start position:0% +where the verifier doesn't even need to +read all of X the guarantees there are + + align:start position:0% +read all of X the guarantees there are + + + align:start position:0% +read all of X the guarantees there are +not very easy to state but it's a very + + align:start position:0% +not very easy to state but it's a very + + + align:start position:0% +not very easy to state but it's a very +useful notion actually it's used a lot + + align:start position:0% +useful notion actually it's used a lot + + + align:start position:0% +useful notion actually it's used a lot +it's called prob uh pcps of + + align:start position:0% +it's called prob uh pcps of + + + align:start position:0% +it's called prob uh pcps of +proximity okay + + align:start position:0% +proximity okay + + + align:start position:0% +proximity okay +so okay so that's what we're going to do + + align:start position:0% +so okay so that's what we're going to do + + + align:start position:0% +so okay so that's what we're going to do +today okay and let me just mention + + align:start position:0% +today okay and let me just mention + + + align:start position:0% +today okay and let me just mention +before even we start the formal thing + + align:start position:0% +before even we start the formal thing + + + align:start position:0% +before even we start the formal thing +let me just say this is really an + + align:start position:0% +let me just say this is really an + + + align:start position:0% +let me just say this is really an +amazing line of work today we know how + + align:start position:0% +amazing line of work today we know how + + + align:start position:0% +amazing line of work today we know how +to take any witness convert it to a + + align:start position:0% +to take any witness convert it to a + + + align:start position:0% +to take any witness convert it to a +probity checkable one that the verifier + + align:start position:0% +probity checkable one that the verifier + + + align:start position:0% +probity checkable one that the verifier +only reads three bits three three bits + + align:start position:0% +only reads three bits three three bits + + + align:start position:0% +only reads three bits three three bits +of this + + align:start position:0% +of this + + + align:start position:0% +of this +uh proof and is convinced with cut and + + align:start position:0% +uh proof and is convinced with cut and + + + align:start position:0% +uh proof and is convinced with cut and +probability 78 is the the parameter but + + align:start position:0% +probability 78 is the the parameter but + + + align:start position:0% +probability 78 is the the parameter but +and then if you want more of course you + + align:start position:0% +and then if you want more of course you + + + align:start position:0% +and then if you want more of course you +repeat but even with just three bits you + + align:start position:0% +repeat but even with just three bits you + + + align:start position:0% +repeat but even with just three bits you +get uh some soundness that's really + + align:start position:0% +get uh some soundness that's really + + + align:start position:0% +get uh some soundness that's really +amazing so we're not going to see the + + align:start position:0% +amazing so we're not going to see the + + + align:start position:0% +amazing so we're not going to see the +three bit proof but we're going to see a + + align:start position:0% +three bit proof but we're going to see a + + + align:start position:0% +three bit proof but we're going to see a +poly Logan proof so what we're going to + + align:start position:0% +poly Logan proof so what we're going to + + + align:start position:0% +poly Logan proof so what we're going to +show what what the construction we're + + align:start position:0% +show what what the construction we're + + + align:start position:0% +show what what the construction we're +going to see today is how to go from a + + align:start position:0% +going to see today is how to go from a + + + align:start position:0% +going to see today is how to go from a +witness to a probability checkable one + + align:start position:0% +witness to a probability checkable one + + + align:start position:0% +witness to a probability checkable one +that the verifier only needs to read + + align:start position:0% +that the verifier only needs to read + + + align:start position:0% +that the verifier only needs to read +polylog + + align:start position:0% +polylog + + + align:start position:0% +polylog +n of this of these uh bits and verify + + align:start position:0% +n of this of these uh bits and verify + + + align:start position:0% +n of this of these uh bits and verify +and to go to the constant there's an + + align:start position:0% +and to go to the constant there's an + + + align:start position:0% +and to go to the constant there's an +additional tricks of recursion and so on + + align:start position:0% +additional tricks of recursion and so on + + + align:start position:0% +additional tricks of recursion and so on +that one needs to do to get there but + + align:start position:0% +that one needs to do to get there but + + + align:start position:0% +that one needs to do to get there but +we're not going to cover that + + align:start position:0% +we're not going to cover that + + + align:start position:0% +we're not going to cover that +part okay ready to roll + + align:start position:0% +part okay ready to roll + + + align:start position:0% +part okay ready to roll +sleeves okay + + align:start position:0% + + + + align:start position:0% + +let's okay so let me just Define the + + align:start position:0% +let's okay so let me just Define the + + + align:start position:0% +let's okay so let me just Define the +complexity class people often think of + + align:start position:0% +complexity class people often think of + + + align:start position:0% +complexity class people often think of +it as a complexity class even though for + + align:start position:0% +it as a complexity class even though for + + + align:start position:0% +it as a complexity class even though for +us because this is more of a proof + + align:start position:0% +us because this is more of a proof + + + align:start position:0% +us because this is more of a proof +system cryptography I know class we + + align:start position:0% +system cryptography I know class we + + + align:start position:0% +system cryptography I know class we +always want efficiency we want we don't + + align:start position:0% +always want efficiency we want we don't + + + align:start position:0% +always want efficiency we want we don't +care just about complexity we want to + + align:start position:0% +care just about complexity we want to + + + align:start position:0% +care just about complexity we want to +say that actually you can take any + + align:start position:0% +say that actually you can take any + + + align:start position:0% +say that actually you can take any +witness and efficiently convert it it's + + align:start position:0% +witness and efficiently convert it it's + + + align:start position:0% +witness and efficiently convert it it's +not just about existence we want to + + align:start position:0% +not just about existence we want to + + + align:start position:0% +not just about existence we want to +actually use these things and let me + + align:start position:0% +actually use these things and let me + + + align:start position:0% +actually use these things and let me +just jump ahead and say that these + + align:start position:0% +just jump ahead and say that these + + + align:start position:0% +just jump ahead and say that these +things are used it's not just a + + align:start position:0% +things are used it's not just a + + + align:start position:0% +things are used it's not just a +theoretical uh you know even though + + align:start position:0% +theoretical uh you know even though + + + align:start position:0% +theoretical uh you know even though +everything we've seen so far in the + + align:start position:0% +everything we've seen so far in the + + + align:start position:0% +everything we've seen so far in the +class is like very just beautiful + + align:start position:0% +class is like very just beautiful + + + align:start position:0% +class is like very just beautiful +mathematically it seems a very um a you + + align:start position:0% +mathematically it seems a very um a you + + + align:start position:0% +mathematically it seems a very um a you +know uh a + + align:start position:0% +know uh a + + + align:start position:0% +know uh a +kind of low like a very uh away from + + align:start position:0% +kind of low like a very uh away from + + + align:start position:0% +kind of low like a very uh away from +very far from practice you know and but + + align:start position:0% +very far from practice you know and but + + + align:start position:0% +very far from practice you know and but +actually it's not all these things that + + align:start position:0% +actually it's not all these things that + + + align:start position:0% +actually it's not all these things that +I've shown you so far that you've seen + + align:start position:0% +I've shown you so far that you've seen + + + align:start position:0% +I've shown you so far that you've seen +so far are things that actually are used + + align:start position:0% +so far are things that actually are used + + + align:start position:0% +so far are things that actually are used +and uh so and and the PCP as well uh all + + align:start position:0% +and uh so and and the PCP as well uh all + + + align:start position:0% +and uh so and and the PCP as well uh all +this Machinery are things that too so we + + align:start position:0% +this Machinery are things that too so we + + + align:start position:0% +this Machinery are things that too so we +actually do care about efficiency but + + align:start position:0% +actually do care about efficiency but + + + align:start position:0% +actually do care about efficiency but +let me first kind of Define it as a + + align:start position:0% +let me first kind of Define it as a + + + align:start position:0% +let me first kind of Define it as a +complexity class so we defined the + + align:start position:0% +complexity class so we defined the + + + align:start position:0% +complexity class so we defined the +complex the complexity class PCP C for + + align:start position:0% +complex the complexity class PCP C for + + + align:start position:0% +complex the complexity class PCP C for +for completeness parameter s for + + align:start position:0% +for completeness parameter s for + + + align:start position:0% +for completeness parameter s for +soundness parameter R for Randomness + + align:start position:0% +soundness parameter R for Randomness + + + align:start position:0% +soundness parameter R for Randomness +parameter and Q for query parameter so + + align:start position:0% +parameter and Q for query parameter so + + + align:start position:0% +parameter and Q for query parameter so +this is a class this is the + + align:start position:0% +this is a class this is the + + + align:start position:0% +this is a class this is the +class of all + + align:start position:0% + + + + align:start position:0% + +languages + + align:start position:0% + + + + align:start position:0% + +L A that + + align:start position:0% + + + + align:start position:0% + +have a probabilistically able proof but + + align:start position:0% +have a probabilistically able proof but + + + align:start position:0% +have a probabilistically able proof but +I'll explain exactly what I mean uh okay + + align:start position:0% +I'll explain exactly what I mean uh okay + + + align:start position:0% +I'll explain exactly what I mean uh okay +so actually let me say a okay these are + + align:start position:0% +so actually let me say a okay these are + + + align:start position:0% +so actually let me say a okay these are +all the let me write it + + align:start position:0% +all the let me write it + + + align:start position:0% +all the let me write it +formally for which these are all the + + align:start position:0% +formally for which these are all the + + + align:start position:0% +formally for which these are all the +languages L such that there + + align:start position:0% + + + + align:start position:0% + +exists uh PPT a probabilistic polinomial + + align:start position:0% +exists uh PPT a probabilistic polinomial + + + align:start position:0% +exists uh PPT a probabilistic polinomial +Time + + align:start position:0% +Time + + + align:start position:0% +Time +verifier + + align:start position:0% +verifier + + + align:start position:0% +verifier +a actually it's a a PPT Oracle machine + + align:start position:0% +a actually it's a a PPT Oracle machine + + + align:start position:0% +a actually it's a a PPT Oracle machine +because it takes the PCP is an oracle + + align:start position:0% +because it takes the PCP is an oracle + + + align:start position:0% +because it takes the PCP is an oracle +Oracle + + align:start position:0% +Oracle + + + align:start position:0% +Oracle +machine v such + + align:start position:0% +machine v such + + + align:start position:0% +machine v such +that okay so the + + align:start position:0% + + + + align:start position:0% + +completeness here's the condition the + + align:start position:0% +completeness here's the condition the + + + align:start position:0% +completeness here's the condition the +completeness says that for every X in + + align:start position:0% +completeness says that for every X in + + + align:start position:0% +completeness says that for every X in +the language there exists a PCP Pi such + + align:start position:0% +the language there exists a PCP Pi such + + + align:start position:0% +the language there exists a PCP Pi such +that the probability that V the verifier + + align:start position:0% +that the probability that V the verifier + + + align:start position:0% +that the probability that V the verifier +given Oracle access to this PCP pi and + + align:start position:0% +given Oracle access to this PCP pi and + + + align:start position:0% +given Oracle access to this PCP pi and +input the instance so for every instance + + align:start position:0% +input the instance so for every instance + + + align:start position:0% +input the instance so for every instance +there exists a PCP so that the verifier + + align:start position:0% +there exists a PCP so that the verifier + + + align:start position:0% +there exists a PCP so that the verifier +will accept it will output one with + + align:start position:0% +will accept it will output one with + + + align:start position:0% +will accept it will output one with +probability at least C that's the + + align:start position:0% +probability at least C that's the + + + align:start position:0% +probability at least C that's the +completeness parameter for us the PCP + + align:start position:0% +completeness parameter for us the PCP + + + align:start position:0% +completeness parameter for us the PCP +will see we'll have complet this + + align:start position:0% +will see we'll have complet this + + + align:start position:0% +will see we'll have complet this +parameter one okay so we'll see so we + + align:start position:0% +parameter one okay so we'll see so we + + + align:start position:0% +parameter one okay so we'll see so we +want to say that a class that a language + + align:start position:0% +want to say that a class that a language + + + align:start position:0% +want to say that a class that a language +L has such a PCP if there's a verifier V + + align:start position:0% +L has such a PCP if there's a verifier V + + + align:start position:0% +L has such a PCP if there's a verifier V +efficient verifier it takes Oracle axis + + align:start position:0% +efficient verifier it takes Oracle axis + + + align:start position:0% +efficient verifier it takes Oracle axis +so if x is in the language there exists + + align:start position:0% +so if x is in the language there exists + + + align:start position:0% +so if x is in the language there exists +in PCP so I to verify with Oracle axis + + align:start position:0% +in PCP so I to verify with Oracle axis + + + align:start position:0% +in PCP so I to verify with Oracle axis +of this PCP given this input outputs one + + align:start position:0% +of this PCP given this input outputs one + + + align:start position:0% +of this PCP given this input outputs one +with probity C yes maybe I'm jumping a + + align:start position:0% +with probity C yes maybe I'm jumping a + + + align:start position:0% +with probity C yes maybe I'm jumping a +bit but what does the Oracle look like + + align:start position:0% +bit but what does the Oracle look like + + + align:start position:0% +bit but what does the Oracle look like +like what are the inputs okay good good + + align:start position:0% +like what are the inputs okay good good + + + align:start position:0% +like what are the inputs okay good good +good so this okay oh good no you're not + + align:start position:0% +good so this okay oh good no you're not + + + align:start position:0% +good so this okay oh good no you're not +jumping so good good question so this Pi + + align:start position:0% +jumping so good good question so this Pi + + + align:start position:0% +jumping so good good question so this Pi +you should think of it as a + + align:start position:0% +you should think of it as a + + + align:start position:0% +you should think of it as a +string it has bits B1 maybe I call it Pi + + align:start position:0% +string it has bits B1 maybe I call it Pi + + + align:start position:0% +string it has bits B1 maybe I call it Pi +1 Pi 2 up to Pi I don't know + + align:start position:0% +1 Pi 2 up to Pi I don't know + + + align:start position:0% +1 Pi 2 up to Pi I don't know +n and uh the verifier can ask give me + + align:start position:0% +n and uh the verifier can ask give me + + + align:start position:0% +n and uh the verifier can ask give me +like Pi 1 give me pi 2 give me pi 3 so + + align:start position:0% +like Pi 1 give me pi 2 give me pi 3 so + + + align:start position:0% +like Pi 1 give me pi 2 give me pi 3 so +he just has Oracle queries he can query + + align:start position:0% +he just has Oracle queries he can query + + + align:start position:0% +he just has Oracle queries he can query +this string okay that's what Oracle it's + + align:start position:0% +this string okay that's what Oracle it's + + + align:start position:0% +this string okay that's what Oracle it's +not really don't think of it as a + + align:start position:0% +not really don't think of it as a + + + align:start position:0% +not really don't think of it as a +function he has Oracle access to the + + align:start position:0% +function he has Oracle access to the + + + align:start position:0% +function he has Oracle access to the +string and he can just ask for specific + + align:start position:0% +string and he can just ask for specific + + + align:start position:0% +string and he can just ask for specific +bits from the string great question + + align:start position:0% +bits from the string great question + + + align:start position:0% +bits from the string great question +thank + + align:start position:0% +thank + + + align:start position:0% +thank +you okay uh good and the sound is + + align:start position:0% + + + + align:start position:0% + +guarantee says that that for every X + + align:start position:0% +guarantee says that that for every X + + + align:start position:0% +guarantee says that that for every X +that's not in the + + align:start position:0% +that's not in the + + + align:start position:0% +that's not in the +language any any guesses by the way what + + align:start position:0% +language any any guesses by the way what + + + align:start position:0% +language any any guesses by the way what +would you okay so you need to define a + + align:start position:0% +would you okay so you need to define a + + + align:start position:0% +would you okay so you need to define a +PCP here how would you define + + align:start position:0% +PCP here how would you define + + + align:start position:0% +PCP here how would you define +sonus yeah for + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +wonderful exactly you want to say that + + align:start position:0% +wonderful exactly you want to say that + + + align:start position:0% +wonderful exactly you want to say that +for every Pi star this know how we do + + align:start position:0% +for every Pi star this know how we do + + + align:start position:0% +for every Pi star this know how we do +note bad things Prime will do too uh for + + align:start position:0% +note bad things Prime will do too uh for + + + align:start position:0% +note bad things Prime will do too uh for +every bad now there's a cheating Pro he + + align:start position:0% +every bad now there's a cheating Pro he + + + align:start position:0% +every bad now there's a cheating Pro he +tries to fool the verifier he cannot so + + align:start position:0% +tries to fool the verifier he cannot so + + + align:start position:0% +tries to fool the verifier he cannot so +for no matter what he tries to give him + + align:start position:0% +for no matter what he tries to give him + + + align:start position:0% +for no matter what he tries to give him +the verifier will reject him with + + align:start position:0% +the verifier will reject him with + + + align:start position:0% +the verifier will reject him with +probability or a will accept probability + + align:start position:0% +probability or a will accept probability + + + align:start position:0% +probability or a will accept probability +smaller than + + align:start position:0% +smaller than + + + align:start position:0% +smaller than +S that's the soundness guarantee okay + + align:start position:0% +S that's the soundness guarantee okay + + + align:start position:0% +S that's the soundness guarantee okay +and ideally we want to push the + + align:start position:0% +and ideally we want to push the + + + align:start position:0% +and ideally we want to push the +completeness to one the soundness to + + align:start position:0% +completeness to one the soundness to + + + align:start position:0% +completeness to one the soundness to +zero great and then the a the + + align:start position:0% +zero great and then the a the + + + align:start position:0% +zero great and then the a the +complexity uh is now we want to say in + + align:start position:0% +complexity uh is now we want to say in + + + align:start position:0% +complexity uh is now we want to say in +terms of complexity now we'll go to + + align:start position:0% + + + + align:start position:0% + +the the V + + align:start position:0% +the the V + + + align:start position:0% +the the V +uses our bits of + + align:start position:0% + + + + align:start position:0% + +Randomness and Q Oracle + + align:start position:0% + + + + align:start position:0% + +calls and moreover we'll see this is + + align:start position:0% +calls and moreover we'll see this is + + + align:start position:0% +calls and moreover we'll see this is +important for us this is often in the + + align:start position:0% +important for us this is often in the + + + align:start position:0% +important for us this is often in the +definition though not always but often + + align:start position:0% +definition though not always but often + + + align:start position:0% +definition though not always but often +this is part of the Q + + align:start position:0% + + + + align:start position:0% + +nonadaptive what do I mean by + + align:start position:0% +nonadaptive what do I mean by + + + align:start position:0% +nonadaptive what do I mean by +nonadaptive what I mean is the way V + + align:start position:0% +nonadaptive what I mean is the way V + + + align:start position:0% +nonadaptive what I mean is the way V +Works he gets input X he gets input X he + + align:start position:0% +Works he gets input X he gets input X he + + + align:start position:0% +Works he gets input X he gets input X he +then chooses kind of + + align:start position:0% +then chooses kind of + + + align:start position:0% +then chooses kind of +i1 up to + + align:start position:0% + + + + align:start position:0% + +IQ locations in the PCP okay so here's + + align:start position:0% +IQ locations in the PCP okay so here's + + + align:start position:0% +IQ locations in the PCP okay so here's +the v v he doesn't even look at the + + align:start position:0% +the v v he doesn't even look at the + + + align:start position:0% +the v v he doesn't even look at the +Oracle yet he has an input X + + align:start position:0% +Oracle yet he has an input X + + + align:start position:0% +Oracle yet he has an input X +he first computes Q + + align:start position:0% +he first computes Q + + + align:start position:0% +he first computes Q +locations he then goes to the Oracle + + align:start position:0% +locations he then goes to the Oracle + + + align:start position:0% +locations he then goes to the Oracle +asks these Q locations and then so V1 + + align:start position:0% +asks these Q locations and then so V1 + + + align:start position:0% +asks these Q locations and then so V1 +just just these locations and then V2 so + + align:start position:0% +just just these locations and then V2 so + + + align:start position:0% +just just these locations and then V2 so +you can think of v as being like V1 and + + align:start position:0% +you can think of v as being like V1 and + + + align:start position:0% +you can think of v as being like V1 and +V2 V1 doesn't look at his Oracle he just + + align:start position:0% +V2 V1 doesn't look at his Oracle he just + + + align:start position:0% +V2 V1 doesn't look at his Oracle he just +looks as an + + align:start position:0% +looks as an + + + align:start position:0% +looks as an +input and using Randomness chooses Q + + align:start position:0% +input and using Randomness chooses Q + + + align:start position:0% +input and using Randomness chooses Q +locations and then + + align:start position:0% +locations and then + + + align:start position:0% +locations and then +V2 kind of uh just given + + align:start position:0% +V2 kind of uh just given + + + align:start position:0% +V2 kind of uh just given +X i1 up to IQ and Pi i1 up to Pi + + align:start position:0% +X i1 up to IQ and Pi i1 up to Pi + + + align:start position:0% +X i1 up to IQ and Pi i1 up to Pi +IQ decides if to like uh accept or + + align:start position:0% +IQ decides if to like uh accept or + + + align:start position:0% +IQ decides if to like uh accept or +reject okay so this is the how you + + align:start position:0% +reject okay so this is the how you + + + align:start position:0% +reject okay so this is the how you +should think of the of the verifier the + + align:start position:0% +should think of the of the verifier the + + + align:start position:0% +should think of the of the verifier the +verifier has access to the proof Pi but + + align:start position:0% +verifier has access to the proof Pi but + + + align:start position:0% +verifier has access to the proof Pi but +what he does he does he because a more + + align:start position:0% +what he does he does he because a more + + + align:start position:0% +what he does he does he because a more +General verifier will have X decide on + + align:start position:0% +General verifier will have X decide on + + + align:start position:0% +General verifier will have X decide on +location first location 3 i1 look at Pi + + align:start position:0% +location first location 3 i1 look at Pi + + + align:start position:0% +location first location 3 i1 look at Pi +1 then hm interesting okay in that case + + align:start position:0% +1 then hm interesting okay in that case + + + align:start position:0% +1 then hm interesting okay in that case +I want to see location I2 h i get Pi I2 + + align:start position:0% +I want to see location I2 h i get Pi I2 + + + align:start position:0% +I want to see location I2 h i get Pi I2 +interesting given Pi I2 I want to see + + align:start position:0% +interesting given Pi I2 I want to see + + + align:start position:0% +interesting given Pi I2 I want to see +location that would be an Adaptive + + align:start position:0% +location that would be an Adaptive + + + align:start position:0% +location that would be an Adaptive +verifier okay but often in the PCP + + align:start position:0% +verifier okay but often in the PCP + + + align:start position:0% +verifier okay but often in the PCP +literature when we Define PCP we require + + align:start position:0% +literature when we Define PCP we require + + + align:start position:0% +literature when we Define PCP we require +the verifier to be + + align:start position:0% +the verifier to be + + + align:start position:0% +the verifier to be +non-adaptive and this non- adaptivity is + + align:start position:0% +non-adaptive and this non- adaptivity is + + + align:start position:0% +non-adaptive and this non- adaptivity is +kind of uh is it's a property that we + + align:start position:0% +kind of uh is it's a property that we + + + align:start position:0% +kind of uh is it's a property that we +like for applications and we'll see that + + align:start position:0% +like for applications and we'll see that + + + align:start position:0% +like for applications and we'll see that +today uh why an example for why when + + align:start position:0% +today uh why an example for why when + + + align:start position:0% +today uh why an example for why when +we'll construct succinct arguments we'll + + align:start position:0% +we'll construct succinct arguments we'll + + + align:start position:0% +we'll construct succinct arguments we'll +use the fact that it's non adaptive but + + align:start position:0% +use the fact that it's non adaptive but + + + align:start position:0% +use the fact that it's non adaptive but +let me just say most PCP all pcps I know + + align:start position:0% +let me just say most PCP all pcps I know + + + align:start position:0% +let me just say most PCP all pcps I know +are nonadaptive maybe there other was + + align:start position:0% +are nonadaptive maybe there other was + + + align:start position:0% +are nonadaptive maybe there other was +that your question yeah so I don't I + + align:start position:0% +that your question yeah so I don't I + + + align:start position:0% +that your question yeah so I don't I +there may exist I'm not you know I'm not + + align:start position:0% +there may exist I'm not you know I'm not + + + align:start position:0% +there may exist I'm not you know I'm not +uh I didn't do a full literature search + + align:start position:0% +uh I didn't do a full literature search + + + align:start position:0% +uh I didn't do a full literature search +but the pcps that are you know the most + + align:start position:0% +but the pcps that are you know the most + + + align:start position:0% +but the pcps that are you know the most +common ones that we talk about are all + + align:start position:0% +common ones that we talk about are all + + + align:start position:0% +common ones that we talk about are all +non-adaptive yeah did V get to know what + + align:start position:0% +non-adaptive yeah did V get to know what + + + align:start position:0% +non-adaptive yeah did V get to know what +capital N is yeah yeah yeah yeah so V + + align:start position:0% +capital N is yeah yeah yeah yeah so V + + + align:start position:0% +capital N is yeah yeah yeah yeah so V +yes V knows yeah so V good very good + + align:start position:0% +yes V knows yeah so V good very good + + + align:start position:0% +yes V knows yeah so V good very good +question let me repeat for the uh video + + align:start position:0% +question let me repeat for the uh video + + + align:start position:0% +question let me repeat for the uh video +uh so the question was does v know what + + align:start position:0% +uh so the question was does v know what + + + align:start position:0% +uh so the question was does v know what +n what capital N is so the answer is yes + + align:start position:0% +n what capital N is so the answer is yes + + + align:start position:0% +n what capital N is so the answer is yes +and the V knows uh V knows the language + + align:start position:0% +and the V knows uh V knows the language + + + align:start position:0% +and the V knows uh V knows the language +so he knows what small n is well he got + + align:start position:0% +so he knows what small n is well he got + + + align:start position:0% +so he knows what small n is well he got +small n he knows small n the language + + align:start position:0% +small n he knows small n the language + + + align:start position:0% +small n he knows small n the language +has like is there's M so he V get small + + align:start position:0% +has like is there's M so he V get small + + + align:start position:0% +has like is there's M so he V get small +n so he knows what an N is the language + + align:start position:0% +n so he knows what an N is the language + + + align:start position:0% +n so he knows what an N is the language +is associated with the witness size M of + + align:start position:0% +is associated with the witness size M of + + + align:start position:0% +is associated with the witness size M of +n so he knows that because he knows n so + + align:start position:0% +n so he knows that because he knows n so + + + align:start position:0% +n so he knows that because he knows n so +he knows the witness size and the PCP + + align:start position:0% +he knows the witness size and the PCP + + + align:start position:0% +he knows the witness size and the PCP +itself is associated with n which + + align:start position:0% +itself is associated with n which + + + align:start position:0% +itself is associated with n which +is you know you can think of it this way + + align:start position:0% +is you know you can think of it this way + + + align:start position:0% +is you know you can think of it this way +so so the answer is yes these are kind + + align:start position:0% +so so the answer is yes these are kind + + + align:start position:0% +so so the answer is yes these are kind +of fixed these uh M and N are fixed + + align:start position:0% +of fixed these uh M and N are fixed + + + align:start position:0% +of fixed these uh M and N are fixed +parameters that are defined by the PCP + + align:start position:0% +parameters that are defined by the PCP + + + align:start position:0% +parameters that are defined by the PCP +and the prover knows them the verifier + + align:start position:0% +and the prover knows them the verifier + + + align:start position:0% +and the prover knows them the verifier +the pro they yeah yes we gain + + align:start position:0% +the pro they yeah yes we gain + + + align:start position:0% +the pro they yeah yes we gain +orose yes good good good so the question + + align:start position:0% +orose yes good good good so the question + + + align:start position:0% +orose yes good good good so the question +is do we lose something and the answer + + align:start position:0% +is do we lose something and the answer + + + align:start position:0% +is do we lose something and the answer +is we do uh okay so what do we lose and + + align:start position:0% +is we do uh okay so what do we lose and + + + align:start position:0% +is we do uh okay so what do we lose and +what do we gain is your question what we + + align:start position:0% +what do we gain is your question what we + + + align:start position:0% +what do we gain is your question what we +lose is for application so we you when + + align:start position:0% +lose is for application so we you when + + + align:start position:0% +lose is for application so we you when +we'll go to in the second part of + + align:start position:0% +we'll go to in the second part of + + + align:start position:0% +we'll go to in the second part of +today's class we're going to construct + + align:start position:0% +today's class we're going to construct + + + align:start position:0% +today's class we're going to construct +succinct arguments and we're going to + + align:start position:0% +succinct arguments and we're going to + + + align:start position:0% +succinct arguments and we're going to +construct them from pcps and you'll see + + align:start position:0% +construct them from pcps and you'll see + + + align:start position:0% +construct them from pcps and you'll see +that if our PCP is adaptive this becomes + + align:start position:0% +that if our PCP is adaptive this becomes + + + align:start position:0% +that if our PCP is adaptive this becomes +the problem so we do gain now you're + + align:start position:0% +the problem so we do gain now you're + + + align:start position:0% +the problem so we do gain now you're +saying what do we Lo and so we do lose + + align:start position:0% +saying what do we Lo and so we do lose + + + align:start position:0% +saying what do we Lo and so we do lose +sorry we do lose if we make it adapted + + align:start position:0% +sorry we do lose if we make it adapted + + + align:start position:0% +sorry we do lose if we make it adapted +now you're saying but maybe we gain + + align:start position:0% +now you're saying but maybe we gain + + + align:start position:0% +now you're saying but maybe we gain +something maybe we construct pcps that + + align:start position:0% +something maybe we construct pcps that + + + align:start position:0% +something maybe we construct pcps that +are much better if you make them + + align:start position:0% +are much better if you make them + + + align:start position:0% +are much better if you make them +adaptive and I I don't think so but I'm + + align:start position:0% +adaptive and I I don't think so but I'm + + + align:start position:0% +adaptive and I I don't think so but I'm +not sure maybe maybe one can actually + + align:start position:0% +not sure maybe maybe one can actually + + + align:start position:0% +not sure maybe maybe one can actually +argue that you don't gain anything but I + + align:start position:0% +argue that you don't gain anything but I + + + align:start position:0% +argue that you don't gain anything but I +haven't thought about it um but it's not + + align:start position:0% +haven't thought about it um but it's not + + + align:start position:0% +haven't thought about it um but it's not +something that making it nonadaptive + + align:start position:0% +something that making it nonadaptive + + + align:start position:0% +something that making it nonadaptive +that for all we know is not a price it's + + align:start position:0% +that for all we know is not a price it's + + + align:start position:0% +that for all we know is not a price it's +just our pcps happen to be that way + + align:start position:0% + + + + align:start position:0% + +yeah good good good very very good + + align:start position:0% +yeah good good good very very good + + + align:start position:0% +yeah good good good very very good +question so uh I think I I think maybe I + + align:start position:0% +question so uh I think I I think maybe I + + + align:start position:0% +question so uh I think I I think maybe I +misunderstood but maybe your question + + align:start position:0% +misunderstood but maybe your question + + + align:start position:0% +misunderstood but maybe your question +was is it clear that these have to + + align:start position:0% +was is it clear that these have to + + + align:start position:0% +was is it clear that these have to +depend on X can they even not depend on + + align:start position:0% +depend on X can they even not depend on + + + align:start position:0% +depend on X can they even not depend on +X and the answer is yes actually in the + + align:start position:0% +X and the answer is yes actually in the + + + align:start position:0% +X and the answer is yes actually in the +pcps will see they don't depend on x + + align:start position:0% +pcps will see they don't depend on x + + + align:start position:0% +pcps will see they don't depend on x +okay the pcps we know actually these + + align:start position:0% +okay the pcps we know actually these + + + align:start position:0% +okay the pcps we know actually these +they only depend on you know n and the + + align:start position:0% +they only depend on you know n and the + + + align:start position:0% +they only depend on you know n and the +instance size or or again it's but they + + align:start position:0% +instance size or or again it's but they + + + align:start position:0% +instance size or or again it's but they +don't actually depend on the instance + + align:start position:0% +don't actually depend on the instance + + + align:start position:0% +don't actually depend on the instance +and the PCP I'll construct today you'll + + align:start position:0% +and the PCP I'll construct today you'll + + + align:start position:0% +and the PCP I'll construct today you'll +see that so we'll get back to that that + + align:start position:0% +see that so we'll get back to that that + + + align:start position:0% +see that so we'll get back to that that +really really great questions + + align:start position:0% +really really great questions + + + align:start position:0% +really really great questions +yeah does that + + align:start position:0% +yeah does that + + + align:start position:0% +yeah does that +think knows what indes you're going + + align:start position:0% +think knows what indes you're going + + + align:start position:0% +think knows what indes you're going +Advance you could construct a of course + + align:start position:0% +Advance you could construct a of course + + + align:start position:0% +Advance you could construct a of course +of course great wow guys you're really + + align:start position:0% +of course great wow guys you're really + + + align:start position:0% +of course great wow guys you're really +Lifting me up this is great thank you uh + + align:start position:0% +Lifting me up this is great thank you uh + + + align:start position:0% +Lifting me up this is great thank you uh +yeah 100% so you're what you're saying + + align:start position:0% +yeah 100% so you're what you're saying + + + align:start position:0% +yeah 100% so you're what you're saying +is of course if the ver if the prover + + align:start position:0% +is of course if the ver if the prover + + + align:start position:0% +is of course if the ver if the prover +knew the locations you're quering he + + align:start position:0% +knew the locations you're quering he + + + align:start position:0% +knew the locations you're quering he +will cheat the thing is these locations + + align:start position:0% +will cheat the thing is these locations + + + align:start position:0% +will cheat the thing is these locations +are random the prover doesn't know what + + align:start position:0% +are random the prover doesn't know what + + + align:start position:0% +are random the prover doesn't know what +they are they just don't depend on X + + align:start position:0% +they are they just don't depend on X + + + align:start position:0% +they are they just don't depend on X +okay okay but they they come from a + + align:start position:0% +okay okay but they they come from a + + + align:start position:0% +okay okay but they they come from a +distribution it's very important if + + align:start position:0% +distribution it's very important if + + + align:start position:0% +distribution it's very important if +these were deterministic there's no way + + align:start position:0% +these were deterministic there's no way + + + align:start position:0% +these were deterministic there's no way +if you can do a PCP where these are + + align:start position:0% +if you can do a PCP where these are + + + align:start position:0% +if you can do a PCP where these are +deterministic it's like you took NP and + + align:start position:0% +deterministic it's like you took NP and + + + align:start position:0% +deterministic it's like you took NP and +you just made it end time much smaller + + align:start position:0% +you just made it end time much smaller + + + align:start position:0% +you just made it end time much smaller +like we don't believe that that can + + align:start position:0% +like we don't believe that that can + + + align:start position:0% +like we don't believe that that can +happen in so no it the there's no way we + + align:start position:0% +happen in so no it the there's no way we + + + align:start position:0% +happen in so no it the there's no way we +believe you can construct pcps for which + + align:start position:0% +believe you can construct pcps for which + + + align:start position:0% +believe you can construct pcps for which +the qu the query distribution is + + align:start position:0% +the qu the query distribution is + + + align:start position:0% +the qu the query distribution is +deterministic it's like just fixed this + + align:start position:0% +deterministic it's like just fixed this + + + align:start position:0% +deterministic it's like just fixed this +has to come from a distribution but the + + align:start position:0% +has to come from a distribution but the + + + align:start position:0% +has to come from a distribution but the +question is does this distribution + + align:start position:0% +question is does this distribution + + + align:start position:0% +question is does this distribution +depend on X or does it only depend on + + align:start position:0% +depend on X or does it only depend on + + + align:start position:0% +depend on X or does it only depend on +the parameter n and then and what we'll + + align:start position:0% +the parameter n and then and what we'll + + + align:start position:0% +the parameter n and then and what we'll +see it actually only depends on N it + + align:start position:0% +see it actually only depends on N it + + + align:start position:0% +see it actually only depends on N it +doesn't depend on X so that's what we'll + + align:start position:0% +doesn't depend on X so that's what we'll + + + align:start position:0% +doesn't depend on X so that's what we'll +see a in a + + align:start position:0% + + + + align:start position:0% + +minute great question guys any any more + + align:start position:0% +minute great question guys any any more + + + align:start position:0% +minute great question guys any any more +questions before we + + align:start position:0% + + + + align:start position:0% + +yeah so okay good so actually V1 you can + + align:start position:0% +yeah so okay good so actually V1 you can + + + align:start position:0% +yeah so okay good so actually V1 you can +think of usually V1 is randomized and V2 + + align:start position:0% +think of usually V1 is randomized and V2 + + + align:start position:0% +think of usually V1 is randomized and V2 +is + + align:start position:0% +is + + + align:start position:0% +is +deterministic uh so you can think of it + + align:start position:0% +deterministic uh so you can think of it + + + align:start position:0% +deterministic uh so you can think of it +that way that V1 is randomized V2 is + + align:start position:0% + + + + align:start position:0% + +deterministic okay + + align:start position:0% +deterministic okay + + + align:start position:0% +deterministic okay +uh great so now let me tell you what we + + align:start position:0% +uh great so now let me tell you what we + + + align:start position:0% +uh great so now let me tell you what we +know and what we're going to construct + + align:start position:0% +know and what we're going to construct + + + align:start position:0% +know and what we're going to construct +so here's what we're going to prove + + align:start position:0% +so here's what we're going to prove + + + align:start position:0% +so here's what we're going to prove +today um here is a theorem that we're + + align:start position:0% +today um here is a theorem that we're + + + align:start position:0% +today um here is a theorem that we're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +prove that + + align:start position:0% +prove that + + + align:start position:0% +prove that +PCP with a let's say completeness one + + align:start position:0% +PCP with a let's say completeness one + + + align:start position:0% +PCP with a let's say completeness one +I'll put S as half we can get smaller + + align:start position:0% +I'll put S as half we can get smaller + + + align:start position:0% +I'll put S as half we can get smaller +any con and smaller but I'll just put + + align:start position:0% +any con and smaller but I'll just put + + + align:start position:0% +any con and smaller but I'll just put +half because by repetition uh it doesn't + + align:start position:0% +half because by repetition uh it doesn't + + + align:start position:0% +half because by repetition uh it doesn't +really matter you can get a PCP where + + align:start position:0% +really matter you can get a PCP where + + + align:start position:0% +really matter you can get a PCP where +the query + + align:start position:0% +the query + + + align:start position:0% +the query +complexity is so okay we can get a PCP + + align:start position:0% +complexity is so okay we can get a PCP + + + align:start position:0% +complexity is so okay we can get a PCP +with poly log n query complexity and + + align:start position:0% +with poly log n query complexity and + + + align:start position:0% +with poly log n query complexity and +poly a + + align:start position:0% + + + + align:start position:0% + +login H sorry poly log and Randomness + + align:start position:0% +login H sorry poly log and Randomness + + + align:start position:0% +login H sorry poly log and Randomness +complexity and query complexity for all + + align:start position:0% +complexity and query complexity for all + + + align:start position:0% +complexity and query complexity for all +of + + align:start position:0% +of + + + align:start position:0% +of +NP that's what we're going to see today + + align:start position:0% +NP that's what we're going to see today + + + align:start position:0% +NP that's what we're going to see today +so we're going to see how for any NP + + align:start position:0% +so we're going to see how for any NP + + + align:start position:0% +so we're going to see how for any NP +language we can construct a PCP where + + align:start position:0% +language we can construct a PCP where + + + align:start position:0% +language we can construct a PCP where +the verifier the amount of Randomness he + + align:start position:0% +the verifier the amount of Randomness he + + + align:start position:0% +the verifier the amount of Randomness he +uses is polog and bits of Randomness and + + align:start position:0% +uses is polog and bits of Randomness and + + + align:start position:0% +uses is polog and bits of Randomness and +polog and queries and then we get + + align:start position:0% +polog and queries and then we get + + + align:start position:0% +polog and queries and then we get +completeness one and sound as half + + align:start position:0% + + + + align:start position:0% + +yeaha + + align:start position:0% + + + + align:start position:0% + +usually right right right yeah yeah yeah + + align:start position:0% +usually right right right yeah yeah yeah + + + align:start position:0% +usually right right right yeah yeah yeah +so you're right so often uh okay you're + + align:start position:0% +so you're right so often uh okay you're + + + align:start position:0% +so you're right so often uh okay you're +right the way I wrote it here uh so okay + + align:start position:0% +right the way I wrote it here uh so okay + + + align:start position:0% +right the way I wrote it here uh so okay +why do people care about Randomness + + align:start position:0% +why do people care about Randomness + + + align:start position:0% +why do people care about Randomness +complexity one can say who cares about + + align:start position:0% +complexity one can say who cares about + + + align:start position:0% +complexity one can say who cares about +the random complexity and usually the + + align:start position:0% +the random complexity and usually the + + + align:start position:0% +the random complexity and usually the +way the way I Define PCP and this is + + align:start position:0% +way the way I Define PCP and this is + + + align:start position:0% +way the way I Define PCP and this is +that's why I said it's a complexity + + align:start position:0% +that's why I said it's a complexity + + + align:start position:0% +that's why I said it's a complexity +Theory this is how it's + + align:start position:0% +Theory this is how it's + + + align:start position:0% +Theory this is how it's +defined if if the verifier has only log + + align:start position:0% +defined if if the verifier has only log + + + align:start position:0% +defined if if the verifier has only log +and bits or order lend bits of of + + align:start position:0% +and bits or order lend bits of of + + + align:start position:0% +and bits or order lend bits of of +Randomness then it means that the PCP is + + align:start position:0% +Randomness then it means that the PCP is + + + align:start position:0% +Randomness then it means that the PCP is +only polyn size because look go over all + + align:start position:0% +only polyn size because look go over all + + + align:start position:0% +only polyn size because look go over all +the PO and all the log and bit random + + align:start position:0% +the PO and all the log and bit random + + + align:start position:0% +the PO and all the log and bit random +there's only n of them so that's as much + + align:start position:0% +there's only n of them so that's as much + + + align:start position:0% +there's only n of them so that's as much +as you can uh kind of query so uh so + + align:start position:0% +as you can uh kind of query so uh so + + + align:start position:0% +as you can uh kind of query so uh so +that means the PCV is aized and that's + + align:start position:0% +that means the PCV is aized and that's + + + align:start position:0% +that means the PCV is aized and that's +all we care about okay for me I'm going + + align:start position:0% +all we care about okay for me I'm going + + + align:start position:0% +all we care about okay for me I'm going +to care about so actually for me I'm + + align:start position:0% +to care about so actually for me I'm + + + align:start position:0% +to care about so actually for me I'm +going to add a a requirement actually I + + align:start position:0% +going to add a a requirement actually I + + + align:start position:0% +going to add a a requirement actually I +didn't write it here because it's + + align:start position:0% +didn't write it here because it's + + + align:start position:0% +didn't write it here because it's +usually not defined but I can add a + + align:start position:0% +usually not defined but I can add a + + + align:start position:0% +usually not defined but I can add a +requirement that says this a I'll okay + + align:start position:0% +requirement that says this a I'll okay + + + align:start position:0% +requirement that says this a I'll okay +I'll add it here in tiny this is a a + + align:start position:0% +I'll add it here in tiny this is a a + + + align:start position:0% +I'll add it here in tiny this is a a +requirement that we add in in + + align:start position:0% +requirement that we add in in + + + align:start position:0% +requirement that we add in in +cryptography often what I'm writing now + + align:start position:0% +cryptography often what I'm writing now + + + align:start position:0% +cryptography often what I'm writing now +is not added in the in in the + + align:start position:0% +is not added in the in in the + + + align:start position:0% +is not added in the in in the +definitions but let me write another + + align:start position:0% +definitions but let me write another + + + align:start position:0% +definitions but let me write another +cryptography another that given for + + align:start position:0% +cryptography another that given for + + + align:start position:0% +cryptography another that given for +every + + align:start position:0% +every + + + align:start position:0% +every +X in or X for for every X in l and + + align:start position:0% + + + + align:start position:0% + +witness if it has a + + align:start position:0% +witness if it has a + + + align:start position:0% +witness if it has a +witness W okay so suppose this is a + + align:start position:0% +witness W okay so suppose this is a + + + align:start position:0% +witness W okay so suppose this is a +language in N time I don't know NP or n + + align:start position:0% +language in N time I don't know NP or n + + + align:start position:0% +language in N time I don't know NP or n +time T so it has some witness I want it + + align:start position:0% +time T so it has some witness I want it + + + align:start position:0% +time T so it has some witness I want it +to be the case that given X and W you + + align:start position:0% +to be the case that given X and W you + + + align:start position:0% +to be the case that given X and W you +can + + align:start position:0% +can + + + align:start position:0% +can +efficiently compute Pi so not only there + + align:start position:0% +efficiently compute Pi so not only there + + + align:start position:0% +efficiently compute Pi so not only there +exists Pi of of poly and size you can + + align:start position:0% +exists Pi of of poly and size you can + + + align:start position:0% +exists Pi of of poly and size you can +actually efficiently compute it and + + align:start position:0% +actually efficiently compute it and + + + align:start position:0% +actually efficiently compute it and +because I require efficient Computing I + + align:start position:0% +because I require efficient Computing I + + + align:start position:0% +because I require efficient Computing I +actually don't care anymore so much + + align:start position:0% +actually don't care anymore so much + + + align:start position:0% +actually don't care anymore so much +about the randomness the amount the + + align:start position:0% +about the randomness the amount the + + + align:start position:0% +about the randomness the amount the +number of Randomness uh bits but yeah + + align:start position:0% +number of Randomness uh bits but yeah + + + align:start position:0% +number of Randomness uh bits but yeah +that's a very good point Thank you guys + + align:start position:0% +that's a very good point Thank you guys + + + align:start position:0% +that's a very good point Thank you guys +thank you for the question this is + + align:start position:0% +thank you for the question this is + + + align:start position:0% +thank you for the question this is +great H okay so that's what I'm going to + + align:start position:0% +great H okay so that's what I'm going to + + + align:start position:0% +great H okay so that's what I'm going to +prove even though let me just mention + + align:start position:0% +prove even though let me just mention + + + align:start position:0% +prove even though let me just mention +what is known is you can make this order + + align:start position:0% +what is known is you can make this order + + + align:start position:0% +what is known is you can make this order +login and you can make this + + align:start position:0% + + + + align:start position:0% + +three okay so it's really remarkable if + + align:start position:0% +three okay so it's really remarkable if + + + align:start position:0% +three okay so it's really remarkable if +you think about it wow you can take any + + align:start position:0% +you think about it wow you can take any + + + align:start position:0% +you think about it wow you can take any +proof so you know how I don't know take + + align:start position:0% +proof so you know how I don't know take + + + align:start position:0% +proof so you know how I don't know take +a foras last the take the hardest proof + + align:start position:0% +a foras last the take the hardest proof + + + align:start position:0% +a foras last the take the hardest proof +that we know in mathematics you know one + + align:start position:0% +that we know in mathematics you know one + + + align:start position:0% +that we know in mathematics you know one +can write them in a pro propos checkable + + align:start position:0% +can write them in a pro propos checkable + + + align:start position:0% +can write them in a pro propos checkable +way they you can just take three bits + + align:start position:0% +way they you can just take three bits + + + align:start position:0% +way they you can just take three bits +and verify and if you're not happy with + + align:start position:0% +and verify and if you're not happy with + + + align:start position:0% +and verify and if you're not happy with +probability half repeat it as many times + + align:start position:0% +probability half repeat it as many times + + + align:start position:0% +probability half repeat it as many times +as you want you want prob you want to be + + align:start position:0% +as you want you want prob you want to be + + + align:start position:0% +as you want you want prob you want to be +sure that he can cheat with probability + + align:start position:0% +sure that he can cheat with probability + + + align:start position:0% +sure that he can cheat with probability +only one over two to the 500 repeat it + + align:start position:0% +only one over two to the 500 repeat it + + + align:start position:0% +only one over two to the 500 repeat it +500 times and each one it's like a very + + align:start position:0% +500 times and each one it's like a very + + + align:start position:0% +500 times and each one it's like a very +simple check it depends on three bits so + + align:start position:0% +simple check it depends on three bits so + + + align:start position:0% +simple check it depends on three bits so +it's really + + align:start position:0% + + + + align:start position:0% + +remarkable no never + + align:start position:0% + + + + align:start position:0% + +mindo I guess it doesn't matter + + align:start position:0% +mindo I guess it doesn't matter + + + align:start position:0% +mindo I guess it doesn't matter +to all oh you're saying it's too big + + align:start position:0% +to all oh you're saying it's too big + + + align:start position:0% +to all oh you're saying it's too big +because for theory for practice Yeah but + + align:start position:0% +because for theory for practice Yeah but + + + align:start position:0% +because for theory for practice Yeah but +we're still in theory land yeah in + + align:start position:0% +we're still in theory land yeah in + + + align:start position:0% +we're still in theory land yeah in +practice these pcps you want them to be + + align:start position:0% +practice these pcps you want them to be + + + align:start position:0% +practice these pcps you want them to be +like linear that's the ideal the Quasi + + align:start position:0% +like linear that's the ideal the Quasi + + + align:start position:0% +like linear that's the ideal the Quasi +linear even if they're quadratic people + + align:start position:0% +linear even if they're quadratic people + + + align:start position:0% +linear even if they're quadratic people +don't like them you really want linear + + align:start position:0% +don't like them you really want linear + + + align:start position:0% +don't like them you really want linear +quasi linear pcps for for practice but + + align:start position:0% +quasi linear pcps for for practice but + + + align:start position:0% +quasi linear pcps for for practice but +for here PA is fantastic we're you know + + align:start position:0% +for here PA is fantastic we're you know + + + align:start position:0% +for here PA is fantastic we're you know +we're not we're not the let us stand the + + align:start position:0% +we're not we're not the let us stand the + + + align:start position:0% +we're not we're not the let us stand the +cloud a little bit okay so uh so okay so + + align:start position:0% +cloud a little bit okay so uh so okay so + + + align:start position:0% +cloud a little bit okay so uh so okay so +let's uh let's construct + + align:start position:0% +let's uh let's construct + + + align:start position:0% +let's uh let's construct +this ready okay so okay so we have the + + align:start position:0% +this ready okay so okay so we have the + + + align:start position:0% +this ready okay so okay so we have the +three but we're going to construct for + + align:start position:0% +three but we're going to construct for + + + align:start position:0% +three but we're going to construct for +the polog polog and what actually here's + + align:start position:0% +the polog polog and what actually here's + + + align:start position:0% +the polog polog and what actually here's +what you what's amazing you actually + + align:start position:0% +what you what's amazing you actually + + + align:start position:0% +what you what's amazing you actually +already know how to construct the PCP + + align:start position:0% +already know how to construct the PCP + + + align:start position:0% +already know how to construct the PCP +you just don't know that you know and + + align:start position:0% +you just don't know that you know and + + + align:start position:0% +you just don't know that you know and +how do you construct the PCP it's really + + align:start position:0% +how do you construct the PCP it's really + + + align:start position:0% +how do you construct the PCP it's really +only the GK protocol that's it so you + + align:start position:0% +only the GK protocol that's it so you + + + align:start position:0% +only the GK protocol that's it so you +can unfold gkr and I'm going to show you + + align:start position:0% +can unfold gkr and I'm going to show you + + + align:start position:0% +can unfold gkr and I'm going to show you +exactly how to make it a + + align:start position:0% +exactly how to make it a + + + align:start position:0% +exactly how to make it a +PCP okay so to do that but before and + + align:start position:0% +PCP okay so to do that but before and + + + align:start position:0% +PCP okay so to do that but before and +I'll recall the GK in a second on that + + align:start position:0% +I'll recall the GK in a second on that + + + align:start position:0% +I'll recall the GK in a second on that +board but to do that let's first let's + + align:start position:0% +board but to do that let's first let's + + + align:start position:0% +board but to do that let's first let's +first so I want to say any any language + + align:start position:0% +first so I want to say any any language + + + align:start position:0% +first so I want to say any any language +has a PCP let's con let's + + align:start position:0% + + + + align:start position:0% + +focus on on three set + + align:start position:0% + + + + align:start position:0% + +okay so thre set is an NP complete + + align:start position:0% +okay so thre set is an NP complete + + + align:start position:0% +okay so thre set is an NP complete +language let's just construct a PTP for + + align:start position:0% +language let's just construct a PTP for + + + align:start position:0% +language let's just construct a PTP for +three set and what's nice about three + + align:start position:0% +three set and what's nice about three + + + align:start position:0% +three set and what's nice about three +set is that I mean any NP language you + + align:start position:0% +set is that I mean any NP language you + + + align:start position:0% +set is that I mean any NP language you +can convert to three set so it's nice + + align:start position:0% +can convert to three set so it's nice + + + align:start position:0% +can convert to three set so it's nice +any NP language is that you have a + + align:start position:0% +any NP language is that you have a + + + align:start position:0% +any NP language is that you have a +circuit a verification + + align:start position:0% +circuit a verification + + + align:start position:0% +circuit a verification +circuit so a circuit verifying so you + + align:start position:0% +circuit so a circuit verifying so you + + + align:start position:0% +circuit so a circuit verifying so you +can think of it uh given W verifying + + align:start position:0% +can think of it uh given W verifying + + + align:start position:0% +can think of it uh given W verifying +that it's a valid witness of very small + + align:start position:0% +that it's a valid witness of very small + + + align:start position:0% +that it's a valid witness of very small +depth okay poly and depth and this is + + align:start position:0% +depth okay poly and depth and this is + + + align:start position:0% +depth okay poly and depth and this is +important because if you remember the GK + + align:start position:0% +important because if you remember the GK + + + align:start position:0% +important because if you remember the GK +protocol which we're going to use to + + align:start position:0% +protocol which we're going to use to + + + align:start position:0% +protocol which we're going to use to +construct this + + align:start position:0% +construct this + + + align:start position:0% +construct this +PCP kind of the number the communication + + align:start position:0% +PCP kind of the number the communication + + + align:start position:0% +PCP kind of the number the communication +complexity grows with the depth so we + + align:start position:0% +complexity grows with the depth so we + + + align:start position:0% +complexity grows with the depth so we +want the depth of the circuit to be + + align:start position:0% +want the depth of the circuit to be + + + align:start position:0% +want the depth of the circuit to be +small but any NP language you can + + align:start position:0% +small but any NP language you can + + + align:start position:0% +small but any NP language you can +convert into a three set and thre set + + align:start position:0% +convert into a three set and thre set + + + align:start position:0% +convert into a three set and thre set +has actually it's like the depth of + + align:start position:0% +has actually it's like the depth of + + + align:start position:0% +has actually it's like the depth of +three set is like actually only two but + + align:start position:0% +three set is like actually only two but + + + align:start position:0% +three set is like actually only two but +like you need to do you know uh little + + align:start position:0% +like you need to do you know uh little + + + align:start position:0% +like you need to do you know uh little +ores and then one big end but if + + align:start position:0% +ores and then one big end but if + + + align:start position:0% +ores and then one big end but if +remember gkr we wanted fan in two + + align:start position:0% +remember gkr we wanted fan in two + + + align:start position:0% +remember gkr we wanted fan in two +so once you have F in two it's like + + align:start position:0% +so once you have F in two it's like + + + align:start position:0% +so once you have F in two it's like +order log okay so this is depth you can + + align:start position:0% +order log okay so this is depth you can + + + align:start position:0% +order log okay so this is depth you can +think of it as being uh a like log in or + + align:start position:0% +think of it as being uh a like log in or + + + align:start position:0% +think of it as being uh a like log in or +I'm okay with poogan it doesn't + + align:start position:0% +I'm okay with poogan it doesn't + + + align:start position:0% +I'm okay with poogan it doesn't +matter the point is it's + + align:start position:0% +matter the point is it's + + + align:start position:0% +matter the point is it's +small and uh the reason why I write also + + align:start position:0% +small and uh the reason why I write also + + + align:start position:0% +small and uh the reason why I write also +polog is because uh it's actually log + + align:start position:0% +polog is because uh it's actually log + + + align:start position:0% +polog is because uh it's actually log +however uh this circuit is also any kind + + align:start position:0% +however uh this circuit is also any kind + + + align:start position:0% +however uh this circuit is also any kind +of the circuit is and this I'm not going + + align:start position:0% +of the circuit is and this I'm not going + + + align:start position:0% +of the circuit is and this I'm not going +to get into but it's log space uniform + + align:start position:0% +to get into but it's log space uniform + + + align:start position:0% +to get into but it's log space uniform +and now you can consider the circuit + + align:start position:0% +and now you can consider the circuit + + + align:start position:0% +and now you can consider the circuit +change it a little bit the way Rachel + + align:start position:0% +change it a little bit the way Rachel + + + align:start position:0% +change it a little bit the way Rachel +taught you two weeks ago if you don't + + align:start position:0% +taught you two weeks ago if you don't + + + align:start position:0% +taught you two weeks ago if you don't +remember it's not it's okay you can take + + align:start position:0% +remember it's not it's okay you can take + + + align:start position:0% +remember it's not it's okay you can take +it as a black box uh you can assume that + + align:start position:0% +it as a black box uh you can assume that + + + align:start position:0% +it as a black box uh you can assume that +The Circuit by kind of looking at a + + align:start position:0% +The Circuit by kind of looking at a + + + align:start position:0% +The Circuit by kind of looking at a +universal version of it you can assume + + align:start position:0% +universal version of it you can assume + + + align:start position:0% +universal version of it you can assume +that it has like the gates add I and + + align:start position:0% +that it has like the gates add I and + + + align:start position:0% +that it has like the gates add I and +multi are efficiently + + align:start position:0% + + + + align:start position:0% + +computable and that's what we'll need so + + align:start position:0% +computable and that's what we'll need so + + + align:start position:0% +computable and that's what we'll need so +we can so if if you don't remember uh + + align:start position:0% +we can so if if you don't remember uh + + + align:start position:0% +we can so if if you don't remember uh +things from weeks ago it's okay I'll + + align:start position:0% +things from weeks ago it's okay I'll + + + align:start position:0% +things from weeks ago it's okay I'll +remind you what add I in multi in a + + align:start position:0% +remind you what add I in multi in a + + + align:start position:0% +remind you what add I in multi in a +second but you take any three set you + + align:start position:0% +second but you take any three set you + + + align:start position:0% +second but you take any three set you +can convert it uh or convert to 3 CNF so + + align:start position:0% +can convert it uh or convert to 3 CNF so + + + align:start position:0% +can convert it uh or convert to 3 CNF so +now given a witness you just check that + + align:start position:0% +now given a witness you just check that + + + align:start position:0% +now given a witness you just check that +it verifies hi hello hey wow all my kids + + align:start position:0% +it verifies hi hello hey wow all my kids + + + align:start position:0% +it verifies hi hello hey wow all my kids +come coming + + align:start position:0% + + + + align:start position:0% + +in okay so uh + + align:start position:0% +in okay so uh + + + align:start position:0% +in okay so uh +a you just uh we talking about how to + + align:start position:0% +a you just uh we talking about how to + + + align:start position:0% +a you just uh we talking about how to +construct pcps from gkr right + + align:start position:0% +construct pcps from gkr right + + + align:start position:0% +construct pcps from gkr right +now so what we're proving is that we're + + align:start position:0% +now so what we're proving is that we're + + + align:start position:0% +now so what we're proving is that we're +going to show how you can take any NP + + align:start position:0% +going to show how you can take any NP + + + align:start position:0% +going to show how you can take any NP +language in particular we're focusing on + + align:start position:0% +language in particular we're focusing on + + + align:start position:0% +language in particular we're focusing on +three sat and we're going to show how + + align:start position:0% +three sat and we're going to show how + + + align:start position:0% +three sat and we're going to show how +you can convert three sat into a PCP + + align:start position:0% +you can convert three sat into a PCP + + + align:start position:0% +you can convert three sat into a PCP +where the query complexity is poly Logan + + align:start position:0% +where the query complexity is poly Logan + + + align:start position:0% +where the query complexity is poly Logan +so converting to PCP the verifier needs + + align:start position:0% +so converting to PCP the verifier needs + + + align:start position:0% +so converting to PCP the verifier needs +to query only poly Logan uh locations we + + align:start position:0% +to query only poly Logan uh locations we + + + align:start position:0% +to query only poly Logan uh locations we +know you can do go all the way down to + + align:start position:0% +know you can do go all the way down to + + + align:start position:0% +know you can do go all the way down to +three but we're not uh today we're going + + align:start position:0% +three but we're not uh today we're going + + + align:start position:0% +three but we're not uh today we're going +to so polog this is the randomness + + align:start position:0% +to so polog this is the randomness + + + align:start position:0% +to so polog this is the randomness +complexity this is the query complexity + + align:start position:0% +complexity this is the query complexity + + + align:start position:0% +complexity this is the query complexity +we're focusing on completeness one sound + + align:start position:0% +we're focusing on completeness one sound + + + align:start position:0% +we're focusing on completeness one sound +is half okay so we're going to now + + align:start position:0% +is half okay so we're going to now + + + align:start position:0% +is half okay so we're going to now +construct the PCP and uh before we conr + + align:start position:0% +construct the PCP and uh before we conr + + + align:start position:0% +construct the PCP and uh before we conr +the P the PCP essentially uses gkr so + + align:start position:0% +the P the PCP essentially uses gkr so + + + align:start position:0% +the P the PCP essentially uses gkr so +let me first on this board remind you + + align:start position:0% +let me first on this board remind you + + + align:start position:0% +let me first on this board remind you +quickly what gkr looks like because + + align:start position:0% +quickly what gkr looks like because + + + align:start position:0% +quickly what gkr looks like because +we're going to use it to constuct the + + align:start position:0% +we're going to use it to constuct the + + + align:start position:0% +we're going to use it to constuct the +PCP okay you're cameraman it's okay to + + align:start position:0% +PCP okay you're cameraman it's okay to + + + align:start position:0% +PCP okay you're cameraman it's okay to +move okay okay + + align:start position:0% +move okay okay + + + align:start position:0% +move okay okay +um good so let's let's just recall the + + align:start position:0% +um good so let's let's just recall the + + + align:start position:0% +um good so let's let's just recall the +gkr how does it work we have a + + align:start position:0% +gkr how does it work we have a + + + align:start position:0% +gkr how does it work we have a +circuit there's an input W we're going + + align:start position:0% +circuit there's an input W we're going + + + align:start position:0% +circuit there's an input W we're going +to think of w here as the the satisfying + + align:start position:0% +to think of w here as the the satisfying + + + align:start position:0% +to think of w here as the the satisfying +assignment okay remember in the DK we + + align:start position:0% +assignment okay remember in the DK we + + + align:start position:0% +assignment okay remember in the DK we +assume the verifier has W in his hand + + align:start position:0% +assume the verifier has W in his hand + + + align:start position:0% +assume the verifier has W in his hand +the W the input in his hand here he + + align:start position:0% +the W the input in his hand here he + + + align:start position:0% +the W the input in his hand here he +doesn't W is going to be the witness for + + align:start position:0% +doesn't W is going to be the witness for + + + align:start position:0% +doesn't W is going to be the witness for +the satisfying assignment but that's + + align:start position:0% +the satisfying assignment but that's + + + align:start position:0% +the satisfying assignment but that's +okay now here's what so I'm I'm GNA + + align:start position:0% +okay now here's what so I'm I'm GNA + + + align:start position:0% +okay now here's what so I'm I'm GNA +construct the PCP proof okay I have my + + align:start position:0% +construct the PCP proof okay I have my + + + align:start position:0% +construct the PCP proof okay I have my +witness my satisfying + + align:start position:0% +witness my satisfying + + + align:start position:0% +witness my satisfying +assignment I'm going to construct a + + align:start position:0% +assignment I'm going to construct a + + + align:start position:0% +assignment I'm going to construct a +protic I'm going to convert W into a PCP + + align:start position:0% +protic I'm going to convert W into a PCP + + + align:start position:0% +protic I'm going to convert W into a PCP +into a protic checkable proof okay + + align:start position:0% +into a protic checkable proof okay + + + align:start position:0% +into a protic checkable proof okay +here's how I do it I look at the kind + + align:start position:0% +here's how I do it I look at the kind + + + align:start position:0% +here's how I do it I look at the kind +the circuit that checks that uh W + + align:start position:0% +the circuit that checks that uh W + + + align:start position:0% +the circuit that checks that uh W +actually you can if you want to think of + + align:start position:0% +actually you can if you want to think of + + + align:start position:0% +actually you can if you want to think of +it's completely new form you can think + + align:start position:0% +it's completely new form you can think + + + align:start position:0% +it's completely new form you can think +of having X and W so X and W and it + + align:start position:0% +of having X and W so X and W and it + + + align:start position:0% +of having X and W so X and W and it +checks that uh kind of fe uh sorry that + + align:start position:0% +checks that uh kind of fe uh sorry that + + + align:start position:0% +checks that uh kind of fe uh sorry that +or okay X which is Fe and it checks that + + align:start position:0% +or okay X which is Fe and it checks that + + + align:start position:0% +or okay X which is Fe and it checks that +F of w is one okay this is a log space + + align:start position:0% +F of w is one okay this is a log space + + + align:start position:0% +F of w is one okay this is a log space +uniform uh circuit and uh okay now what + + align:start position:0% +uniform uh circuit and uh okay now what + + + align:start position:0% +uniform uh circuit and uh okay now what +do I do so here's me I know W every we + + align:start position:0% +do I do so here's me I know W every we + + + align:start position:0% +do I do so here's me I know W every we +both know the three set + + align:start position:0% +both know the three set + + + align:start position:0% +both know the three set +formula what I + + align:start position:0% +formula what I + + + align:start position:0% +formula what I +do I and and we assume that this circuit + + align:start position:0% +do I and and we assume that this circuit + + + align:start position:0% +do I and and we assume that this circuit +is kind of has addition Gates and + + align:start position:0% +is kind of has addition Gates and + + + align:start position:0% +is kind of has addition Gates and +multiplication + + align:start position:0% +multiplication + + + align:start position:0% +multiplication +Gates what I do for every + + align:start position:0% +Gates what I do for every + + + align:start position:0% +Gates what I do for every +layer I compute the values of the layer + + align:start position:0% +layer I compute the values of the layer + + + align:start position:0% +layer I compute the values of the layer +okay so I compute for every layer + + align:start position:0% +okay so I compute for every layer + + + align:start position:0% +okay so I compute for every layer +remember I have VI the I assume every + + align:start position:0% +remember I have VI the I assume every + + + align:start position:0% +remember I have VI the I assume every +layer let's say has size let's say the + + align:start position:0% +layer let's say has size let's say the + + + align:start position:0% +layer let's say has size let's say the +same size without L of generality we + + align:start position:0% +same size without L of generality we + + + align:start position:0% +same size without L of generality we +said size s we called it s so each layer + + align:start position:0% +said size s we called it s so each layer + + + align:start position:0% +said size s we called it s so each layer +has s + + align:start position:0% +has s + + + align:start position:0% +has s +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +wires and uh and we ass and we write we + + align:start position:0% +wires and uh and we ass and we write we + + + align:start position:0% +wires and uh and we ass and we write we +compute all these wires for every layer + + align:start position:0% +compute all these wires for every layer + + + align:start position:0% +compute all these wires for every layer +I we think of this wire as go as going + + align:start position:0% +I we think of this wire as go as going + + + align:start position:0% +I we think of this wire as go as going +from H to M to 01 so H is some set and + + align:start position:0% +from H to M to 01 so H is some set and + + + align:start position:0% +from H to M to 01 so H is some set and +we assume that H to the m is s okay so + + align:start position:0% +we assume that H to the m is s okay so + + + align:start position:0% +we assume that H to the m is s okay so +we just encode these s wires in a kind + + align:start position:0% +we just encode these s wires in a kind + + + align:start position:0% +we just encode these s wires in a kind +of cube uh uh M dimensional cube of size + + align:start position:0% +of cube uh uh M dimensional cube of size + + + align:start position:0% +of cube uh uh M dimensional cube of size +H and we just write all the values of + + align:start position:0% +H and we just write all the values of + + + align:start position:0% +H and we just write all the values of +the + + align:start position:0% +the + + + align:start position:0% +the +wires okay and then what we do we look + + align:start position:0% +wires okay and then what we do we look + + + align:start position:0% +wires okay and then what we do we look +at the extension V Tilda which is + + align:start position:0% +at the extension V Tilda which is + + + align:start position:0% +at the extension V Tilda which is +extends to a field F to the m to F and + + align:start position:0% +extends to a field F to the m to F and + + + align:start position:0% +extends to a field F to the m to F and +this is kind of the low degree extension + + align:start position:0% +this is kind of the low degree extension + + + align:start position:0% +this is kind of the low degree extension +so we take any F that can contains the + + align:start position:0% +so we take any F that can contains the + + + align:start position:0% +so we take any F that can contains the +set H and we extend VI via the low + + align:start position:0% +set H and we extend VI via the low + + + align:start position:0% +set H and we extend VI via the low +degree extension so these are things we + + align:start position:0% +degree extension so these are things we + + + align:start position:0% +degree extension so these are things we +covered okay now now is the first time + + align:start position:0% +covered okay now now is the first time + + + align:start position:0% +covered okay now now is the first time +you remember when I when we taught gkr I + + align:start position:0% +you remember when I when we taught gkr I + + + align:start position:0% +you remember when I when we taught gkr I +told you okay why I do why not do 0o one + + align:start position:0% +told you okay why I do why not do 0o one + + + align:start position:0% +told you okay why I do why not do 0o one +to the m you know 0o to the log in it's + + align:start position:0% +to the m you know 0o to the log in it's + + + align:start position:0% +to the m you know 0o to the log in it's +much natural to think of binary + + align:start position:0% +much natural to think of binary + + + align:start position:0% +much natural to think of binary +representation of s as opposed to this H + + align:start position:0% +representation of s as opposed to this H + + + align:start position:0% +representation of s as opposed to this H +to the m which is what H and I told you + + align:start position:0% +to the m which is what H and I told you + + + align:start position:0% +to the m which is what H and I told you +how often we like parameters we like to + + align:start position:0% +how often we like parameters we like to + + + align:start position:0% +how often we like parameters we like to +think of H as + + align:start position:0% +think of H as + + + align:start position:0% +think of H as +login ah sorry log n and M is log n over + + align:start position:0% +login ah sorry log n and M is log n over + + + align:start position:0% +login ah sorry log n and M is log n over +log log + + align:start position:0% + + + + align:start position:0% + +n uh and if you'll see H to the m is + + align:start position:0% +n uh and if you'll see H to the m is + + + align:start position:0% +n uh and if you'll see H to the m is +just becomes n because uh you can think + + align:start position:0% +just becomes n because uh you can think + + + align:start position:0% +just becomes n because uh you can think +of a so H to the + + align:start position:0% +of a so H to the + + + align:start position:0% +of a so H to the +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +m is log n to the N but log n is just + + align:start position:0% +m is log n to the N but log n is just + + + align:start position:0% +m is log n to the N but log n is just +like two log log + + align:start position:0% + + + + align:start position:0% + +n to the n and the log log n cancels out + + align:start position:0% +n to the n and the log log n cancels out + + + align:start position:0% +n to the n and the log log n cancels out +so you have two to the + + align:start position:0% +so you have two to the + + + align:start position:0% +so you have two to the +again so you have uh oh I did everything + + align:start position:0% +again so you have uh oh I did everything + + + align:start position:0% +again so you have uh oh I did everything +everything is s sorry + + align:start position:0% +everything is s sorry + + + align:start position:0% +everything is s sorry +s the N here is s s s + + align:start position:0% + + + + align:start position:0% + +s so you have S now remember I told I + + align:start position:0% +s so you have S now remember I told I + + + align:start position:0% +s so you have S now remember I told I +told you oh we'll need the set of + + align:start position:0% +told you oh we'll need the set of + + + align:start position:0% +told you oh we'll need the set of +parameters as opposed to say 01 it's + + align:start position:0% +parameters as opposed to say 01 it's + + + align:start position:0% +parameters as opposed to say 01 it's +natural to think of H as 01 and M is log + + align:start position:0% +natural to think of H as 01 and M is log + + + align:start position:0% +natural to think of H as 01 and M is log +n that's much more natural uh we used as + + align:start position:0% +n that's much more natural uh we used as + + + align:start position:0% +n that's much more natural uh we used as +computer science to think in binary now + + align:start position:0% +computer science to think in binary now + + + align:start position:0% +computer science to think in binary now +we're thinking of like log ass it's like + + align:start position:0% +we're thinking of like log ass it's like + + + align:start position:0% +we're thinking of like log ass it's like +really how how annoying can you be and + + align:start position:0% +really how how annoying can you be and + + + align:start position:0% +really how how annoying can you be and +the reason is it's for this now now we + + align:start position:0% +the reason is it's for this now now we + + + align:start position:0% +the reason is it's for this now now we +need it why now we take F that is going + + align:start position:0% +need it why now we take F that is going + + + align:start position:0% +need it why now we take F that is going +to + + align:start position:0% + + + + align:start position:0% + +be it's going to be extension of size + + align:start position:0% +be it's going to be extension of size + + + align:start position:0% +be it's going to be extension of size +poly + + align:start position:0% + + + + align:start position:0% + +logus okay we'll see the poly will need + + align:start position:0% +logus okay we'll see the poly will need + + + align:start position:0% +logus okay we'll see the poly will need +to be big enough we'll talk about in a + + align:start position:0% +to be big enough we'll talk about in a + + + align:start position:0% +to be big enough we'll talk about in a +second but the field we don't we don't + + align:start position:0% +second but the field we don't we don't + + + align:start position:0% +second but the field we don't we don't +want more than poly log s and the reason + + align:start position:0% +want more than poly log s and the reason + + + align:start position:0% +want more than poly log s and the reason +is we want + + align:start position:0% +is we want + + + align:start position:0% +is we want +F to the m to be + + align:start position:0% +F to the m to be + + + align:start position:0% +F to the m to be +polys okay so we know we know that H to + + align:start position:0% +polys okay so we know we know that H to + + + align:start position:0% +polys okay so we know we know that H to +the m is s if if uh f is only poly + + align:start position:0% +the m is s if if uh f is only poly + + + align:start position:0% +the m is s if if uh f is only poly +bigger then we have this is poly + + align:start position:0% + + + + align:start position:0% + +s okay and that's important for us okay + + align:start position:0% +s okay and that's important for us okay + + + align:start position:0% +s okay and that's important for us okay +note if H was just 01 so the size of H + + align:start position:0% +note if H was just 01 so the size of H + + + align:start position:0% +note if H was just 01 so the size of H +was two + + align:start position:0% +was two + + + align:start position:0% +was two +we couldn't keep F poly and to we + + align:start position:0% +we couldn't keep F poly and to we + + + align:start position:0% +we couldn't keep F poly and to we +couldn't keep F constant you'll see F + + align:start position:0% +couldn't keep F constant you'll see F + + + align:start position:0% +couldn't keep F constant you'll see F +will need to grow with m m f so for + + align:start position:0% +will need to grow with m m f so for + + + align:start position:0% +will need to grow with m m f so for +soundness m f will need to be + + align:start position:0% +soundness m f will need to be + + + align:start position:0% +soundness m f will need to be +bigger than M * + + align:start position:0% +bigger than M * + + + align:start position:0% +bigger than M * +H actually there's also D that will come + + align:start position:0% +H actually there's also D that will come + + + align:start position:0% +H actually there's also D that will come +in it's significantly bigger so if we + + align:start position:0% +in it's significantly bigger so if we + + + align:start position:0% +in it's significantly bigger so if we +take H to be two we'll need to take F to + + align:start position:0% +take H to be two we'll need to take F to + + + align:start position:0% +take H to be two we'll need to take F to +be at least log n and then we'll have F + + align:start position:0% +be at least log n and then we'll have F + + + align:start position:0% +be at least log n and then we'll have F +to them is log to the power of log n + + align:start position:0% +to them is log to the power of log n + + + align:start position:0% +to them is log to the power of log n +that's more that's super + + align:start position:0% +that's more that's super + + + align:start position:0% +that's more that's super +poly and I want after them to be + + align:start position:0% +poly and I want after them to be + + + align:start position:0% +poly and I want after them to be +poly okay so we do this so now I so what + + align:start position:0% +poly okay so we do this so now I so what + + + align:start position:0% +poly okay so we do this so now I so what +is the PCP the + + align:start position:0% +is the PCP the + + + align:start position:0% +is the PCP the +PCP so actually I'll write there the PCP + + align:start position:0% +PCP so actually I'll write there the PCP + + + align:start position:0% +PCP so actually I'll write there the PCP +but uh now let's let's just finish + + align:start position:0% +but uh now let's let's just finish + + + align:start position:0% +but uh now let's let's just finish +recalling the GK so what does the + + align:start position:0% +recalling the GK so what does the + + + align:start position:0% +recalling the GK so what does the +verifier do in the GK the pro do in the + + align:start position:0% +verifier do in the GK the pro do in the + + + align:start position:0% +verifier do in the GK the pro do in the +GK he computes all these low degree + + align:start position:0% +GK he computes all these low degree + + + align:start position:0% +GK he computes all these low degree +extensions and then the GK consists of D + + align:start position:0% +extensions and then the GK consists of D + + + align:start position:0% +extensions and then the GK consists of D +phases going from the output layer to + + align:start position:0% +phases going from the output layer to + + + align:start position:0% +phases going from the output layer to +the input layer layer where in each + + align:start position:0% +the input layer layer where in each + + + align:start position:0% +the input layer layer where in each +phase we run two Su check protocols in + + align:start position:0% +phase we run two Su check protocols in + + + align:start position:0% +phase we run two Su check protocols in +parallel where the verifier uses the + + align:start position:0% +parallel where the verifier uses the + + + align:start position:0% +parallel where the verifier uses the +same Randomness and what what the + + align:start position:0% +same Randomness and what what the + + + align:start position:0% +same Randomness and what what the +subject protocol does is it it reduces + + align:start position:0% +subject protocol does is it it reduces + + + align:start position:0% +subject protocol does is it it reduces +from checking two values here to + + align:start position:0% +from checking two values here to + + + align:start position:0% +from checking two values here to +reducing checking two values in the + + align:start position:0% +reducing checking two values in the + + + align:start position:0% +reducing checking two values in the +layer below and we kind of go kind of + + align:start position:0% +layer below and we kind of go kind of + + + align:start position:0% +layer below and we kind of go kind of +from checking uh until we get to the + + align:start position:0% +from checking uh until we get to the + + + align:start position:0% +from checking uh until we get to the +input and then input the verifier can + + align:start position:0% +input and then input the verifier can + + + align:start position:0% +input and then input the verifier can +check on his own that's the + + align:start position:0% +check on his own that's the + + + align:start position:0% +check on his own that's the +idea + + align:start position:0% +idea + + + align:start position:0% +idea +okay okay now let's just Rec in a + + align:start position:0% +okay okay now let's just Rec in a + + + align:start position:0% +okay okay now let's just Rec in a +subject protocol here each subject + + align:start position:0% +subject protocol here each subject + + + align:start position:0% +subject protocol here each subject +protocol if you uh remember maybe you + + align:start position:0% +protocol if you uh remember maybe you + + + align:start position:0% +protocol if you uh remember maybe you +don't it's not the details are not so + + align:start position:0% +don't it's not the details are not so + + + align:start position:0% +don't it's not the details are not so +important right now but it's kind of you + + align:start position:0% +important right now but it's kind of you + + + align:start position:0% +important right now but it's kind of you +go from VI inex tension which is let's + + align:start position:0% +go from VI inex tension which is let's + + + align:start position:0% +go from VI inex tension which is let's +say VI Tilda of some + + align:start position:0% +say VI Tilda of some + + + align:start position:0% +say VI Tilda of some +Z and you write it as this is kind of + + align:start position:0% +Z and you write it as this is kind of + + + align:start position:0% +Z and you write it as this is kind of +sum + + align:start position:0% +sum + + + align:start position:0% +sum +of uh points in the in h to the m + + align:start position:0% +of uh points in the in h to the m + + + align:start position:0% +of uh points in the in h to the m +because that's the definition of + + align:start position:0% +because that's the definition of + + + align:start position:0% +because that's the definition of +extension times some k p uh Z this is + + align:start position:0% +extension times some k p uh Z this is + + + align:start position:0% +extension times some k p uh Z this is +the function that checks equality again + + align:start position:0% +the function that checks equality again + + + align:start position:0% +the function that checks equality again +it's not important but what's important + + align:start position:0% +it's not important but what's important + + + align:start position:0% +it's not important but what's important +to me to show is that and then you do + + align:start position:0% +to me to show is that and then you do + + + align:start position:0% +to me to show is that and then you do +sum over P W1 W2 in h of + + align:start position:0% +sum over P W1 W2 in h of + + + align:start position:0% +sum over P W1 W2 in h of +M and you convert VI to either kind of + + align:start position:0% +M and you convert VI to either kind of + + + align:start position:0% +M and you convert VI to either kind of +uh a if if if this is a plus gate you + + align:start position:0% +uh a if if if this is a plus gate you + + + align:start position:0% +uh a if if if this is a plus gate you +convert it to uh like um the plus of the + + align:start position:0% +convert it to uh like um the plus of the + + + align:start position:0% +convert it to uh like um the plus of the +of the wires below with multiplication + + align:start position:0% +of the wires below with multiplication + + + align:start position:0% +of the wires below with multiplication +you check the multiplication so in other + + align:start position:0% +you check the multiplication so in other + + + align:start position:0% +you check the multiplication so in other +words what this + + align:start position:0% +words what this + + + align:start position:0% +words what this +is what this is or I should say what + + align:start position:0% +is what this is or I should say what + + + align:start position:0% +is what this is or I should say what +this is let me just open this what is VI + + align:start position:0% +this is let me just open this what is VI + + + align:start position:0% +this is let me just open this what is VI +P it's if it's an + + align:start position:0% +P it's if it's an + + + align:start position:0% +P it's if it's an +ad if it's an + + align:start position:0% + + + + align:start position:0% + +ad P W1 W2 so if Point p is this just + + align:start position:0% +ad P W1 W2 so if Point p is this just + + + align:start position:0% +ad P W1 W2 so if Point p is this just +the addition of the two wires below then + + align:start position:0% +the addition of the two wires below then + + + align:start position:0% +the addition of the two wires below then +you replace p with W1 with v + + align:start position:0% +you replace p with W1 with v + + + align:start position:0% +you replace p with W1 with v +ius1 + + align:start position:0% +ius1 + + + align:start position:0% +ius1 +W1 plus VI -1 + + align:start position:0% + + + + align:start position:0% + +W2 and plus if it was not an adgate if + + align:start position:0% +W2 and plus if it was not an adgate if + + + align:start position:0% +W2 and plus if it was not an adgate if +it's a + + align:start position:0% + + + + align:start position:0% + +mgate then you replace it with the + + align:start position:0% +mgate then you replace it with the + + + align:start position:0% +mgate then you replace it with the +multiplication of vi- 1 W1 Time vi- 1 W2 + + align:start position:0% +multiplication of vi- 1 W1 Time vi- 1 W2 + + + align:start position:0% +multiplication of vi- 1 W1 Time vi- 1 W2 +so just uh right the idea was and all + + align:start position:0% +so just uh right the idea was and all + + + align:start position:0% +so just uh right the idea was and all +this is times + + align:start position:0% +this is times + + + align:start position:0% +this is times +uh this + + align:start position:0% +uh this + + + align:start position:0% +uh this +Kai k + + align:start position:0% +Kai k + + + align:start position:0% +Kai k +p z but again how do we go from layer I + + align:start position:0% +p z but again how do we go from layer I + + + align:start position:0% +p z but again how do we go from layer I +toay to one layer below we take that + + align:start position:0% +toay to one layer below we take that + + + align:start position:0% +toay to one layer below we take that +element in the extension we think of it + + align:start position:0% +element in the extension we think of it + + + align:start position:0% +element in the extension we think of it +as a sum that's the definition of lree + + align:start position:0% +as a sum that's the definition of lree + + + align:start position:0% +as a sum that's the definition of lree +extension it's sum of the elements in + + align:start position:0% +extension it's sum of the elements in + + + align:start position:0% +extension it's sum of the elements in +the circuit itself with some with some + + align:start position:0% +the circuit itself with some with some + + + align:start position:0% +the circuit itself with some with some +function uh with some weight and now + + align:start position:0% +function uh with some weight and now + + + align:start position:0% +function uh with some weight and now +look at the at the value what what is + + align:start position:0% +look at the at the value what what is + + + align:start position:0% +look at the at the value what what is +the value of this gate well if it's an + + align:start position:0% +the value of this gate well if it's an + + + align:start position:0% +the value of this gate well if it's an +and if it's an add gate it's the sum of + + align:start position:0% +and if it's an add gate it's the sum of + + + align:start position:0% +and if it's an add gate it's the sum of +the two children and if it's a mgate it + + align:start position:0% +the two children and if it's a mgate it + + + align:start position:0% +the two children and if it's a mgate it +should be the multiplication of the two + + align:start position:0% +should be the multiplication of the two + + + align:start position:0% +should be the multiplication of the two +children and so add I just outputs one + + align:start position:0% +children and so add I just outputs one + + + align:start position:0% +children and so add I just outputs one +of these if you know W1 W2 are the + + align:start position:0% +of these if you know W1 W2 are the + + + align:start position:0% +of these if you know W1 W2 are the +children of P zero otherwise similarly + + align:start position:0% +children of P zero otherwise similarly + + + align:start position:0% +children of P zero otherwise similarly +malt and but we do everything in the + + align:start position:0% +malt and but we do everything in the + + + align:start position:0% +malt and but we do everything in the +extension uh we look at everything in + + align:start position:0% +extension uh we look at everything in + + + align:start position:0% +extension uh we look at everything in +the extension because we want to think + + align:start position:0% +the extension because we want to think + + + align:start position:0% +the extension because we want to think +of it as a polinomial and once we think + + align:start position:0% +of it as a polinomial and once we think + + + align:start position:0% +of it as a polinomial and once we think +once we these are all pols then this is + + align:start position:0% +once we these are all pols then this is + + + align:start position:0% +once we these are all pols then this is +just a sum + + align:start position:0% +just a sum + + + align:start position:0% +just a sum +check okay and we saw a sum check how to + + align:start position:0% +check okay and we saw a sum check how to + + + align:start position:0% +check okay and we saw a sum check how to +do it efficiently so now the point is G + + align:start position:0% +do it efficiently so now the point is G + + + align:start position:0% +do it efficiently so now the point is G +consists of only these two D Su checks + + align:start position:0% +consists of only these two D Su checks + + + align:start position:0% +consists of only these two D Su checks +so now let me go to my + + align:start position:0% + + + + align:start position:0% + +PCP a is this so here's uh our PCP + + align:start position:0% + + + + align:start position:0% + +essentially my PCP is just gkr but + + align:start position:0% +essentially my PCP is just gkr but + + + align:start position:0% +essentially my PCP is just gkr but +opened up completely completely + + align:start position:0% +opened up completely completely + + + align:start position:0% +opened up completely completely +unraveled so okay so here's my PCP I + + align:start position:0% +unraveled so okay so here's my PCP I + + + align:start position:0% +unraveled so okay so here's my PCP I +have my X in W here's what I do I'm + + align:start position:0% +have my X in W here's what I do I'm + + + align:start position:0% +have my X in W here's what I do I'm +going to + + align:start position:0% +going to + + + align:start position:0% +going to +compute all the V1 V VI Tilda the + + align:start position:0% +compute all the V1 V VI Tilda the + + + align:start position:0% +compute all the V1 V VI Tilda the +extension of the values of each of all + + align:start position:0% +extension of the values of each of all + + + align:start position:0% +extension of the values of each of all +the gate in each wire for every + + align:start position:0% +the gate in each wire for every + + + align:start position:0% +the gate in each wire for every +Z for every Z and F to the + + align:start position:0% +Z for every Z and F to the + + + align:start position:0% +Z for every Z and F to the +m it's + + align:start position:0% +m it's + + + align:start position:0% +m it's +important this is going to be all this + + align:start position:0% +important this is going to be all this + + + align:start position:0% +important this is going to be all this +is going to be part of the PCP so if F + + align:start position:0% +is going to be part of the PCP so if F + + + align:start position:0% +is going to be part of the PCP so if F +to m is more than polinomial my PCP is + + align:start position:0% +to m is more than polinomial my PCP is + + + align:start position:0% +to m is more than polinomial my PCP is +super + + align:start position:0% +super + + + align:start position:0% +super +polinomial okay so after to them has to + + align:start position:0% +polinomial okay so after to them has to + + + align:start position:0% +polinomial okay so after to them has to +be polinomial this is a ready sized + + align:start position:0% +be polinomial this is a ready sized + + + align:start position:0% +be polinomial this is a ready sized +polinomial + + align:start position:0% + + + + align:start position:0% + +yeah again sorry we have + + align:start position:0% + + + + align:start position:0% + +the oh yeah yeah yeah yeah yeah yeah + + align:start position:0% +the oh yeah yeah yeah yeah yeah yeah + + + align:start position:0% +the oh yeah yeah yeah yeah yeah yeah +okay good good good yes so for gkr we + + align:start position:0% +okay good good good yes so for gkr we + + + align:start position:0% +okay good good good yes so for gkr we +had a restriction that the + + align:start position:0% +had a restriction that the + + + align:start position:0% +had a restriction that the +circuit to do gkr we said gkr is like is + + align:start position:0% +circuit to do gkr we said gkr is like is + + + align:start position:0% +circuit to do gkr we said gkr is like is +proving that uh bounded depth circuit + + align:start position:0% +proving that uh bounded depth circuit + + + align:start position:0% +proving that uh bounded depth circuit +and put x equals y and we had a + + align:start position:0% +and put x equals y and we had a + + + align:start position:0% +and put x equals y and we had a +restriction that the circuit has to be B + + align:start position:0% +restriction that the circuit has to be B + + + align:start position:0% +restriction that the circuit has to be B +bounded uh space uniform or in other + + align:start position:0% +bounded uh space uniform or in other + + + align:start position:0% +bounded uh space uniform or in other +words we needed to ensure that add I and + + align:start position:0% +words we needed to ensure that add I and + + + align:start position:0% +words we needed to ensure that add I and +mul this ex extended Andi and extended + + align:start position:0% +mul this ex extended Andi and extended + + + align:start position:0% +mul this ex extended Andi and extended +multi are computed computer + + align:start position:0% +multi are computed computer + + + align:start position:0% +multi are computed computer +efficiently threat has that property + + align:start position:0% +efficiently threat has that property + + + align:start position:0% +efficiently threat has that property +okay I again I did go into the details + + align:start position:0% +okay I again I did go into the details + + + align:start position:0% +okay I again I did go into the details +but uh the threet is it's a very unifor + + align:start position:0% +but uh the threet is it's a very unifor + + + align:start position:0% +but uh the threet is it's a very unifor +you know given a FNX it's very uniform + + align:start position:0% +you know given a FNX it's very uniform + + + align:start position:0% +you know given a FNX it's very uniform +to check it's a very it is a loog space + + align:start position:0% +to check it's a very it is a loog space + + + align:start position:0% +to check it's a very it is a loog space +uniform and then we can convert it as + + align:start position:0% +uniform and then we can convert it as + + + align:start position:0% +uniform and then we can convert it as +Rachel uh did two weeks ago uh to kind + + align:start position:0% +Rachel uh did two weeks ago uh to kind + + + align:start position:0% +Rachel uh did two weeks ago uh to kind +of one that has uh by increasing the the + + align:start position:0% +of one that has uh by increasing the the + + + align:start position:0% +of one that has uh by increasing the the +depth by poly factors uh so keeping it + + align:start position:0% +depth by poly factors uh so keeping it + + + align:start position:0% +depth by poly factors uh so keeping it +poly log you can make at I at till and + + align:start position:0% +poly log you can make at I at till and + + + align:start position:0% +poly log you can make at I at till and +multi be efficiently computable so yeah + + align:start position:0% +multi be efficiently computable so yeah + + + align:start position:0% +multi be efficiently computable so yeah +great that's a very good question uh so + + align:start position:0% +great that's a very good question uh so + + + align:start position:0% +great that's a very good question uh so +yes good so this is going to be part of + + align:start position:0% +yes good so this is going to be part of + + + align:start position:0% +yes good so this is going to be part of +the uh PCP but that's not all uh by the + + align:start position:0% +the uh PCP but that's not all uh by the + + + align:start position:0% +the uh PCP but that's not all uh by the +way we should also give uh this we give + + align:start position:0% +way we should also give uh this we give + + + align:start position:0% +way we should also give uh this we give +this for every I from the input layer + + align:start position:0% +this for every I from the input layer + + + align:start position:0% +this for every I from the input layer +zero one up to D this is + + align:start position:0% + + + + align:start position:0% + +output and this is the input layer + + align:start position:0% +output and this is the input layer + + + align:start position:0% +output and this is the input layer +we have to give him the input layer + + align:start position:0% +we have to give him the input layer + + + align:start position:0% +we have to give him the input layer +because the poor verifi verifier doesn't + + align:start position:0% +because the poor verifi verifier doesn't + + + align:start position:0% +because the poor verifi verifier doesn't +have W so he doesn't have actually the + + align:start position:0% +have W so he doesn't have actually the + + + align:start position:0% +have W so he doesn't have actually the +input before he and do you care he had + + align:start position:0% +input before he and do you care he had + + + align:start position:0% +input before he and do you care he had +the input here he doesn't have the input + + align:start position:0% +the input here he doesn't have the input + + + align:start position:0% +the input here he doesn't have the input +but we're going to give him the Lo + + align:start position:0% +but we're going to give him the Lo + + + align:start position:0% +but we're going to give him the Lo +extension of this W okay good now but + + align:start position:0% +extension of this W okay good now but + + + align:start position:0% +extension of this W okay good now but +okay so I'm the verifier what do I do I + + align:start position:0% +okay so I'm the verifier what do I do I + + + align:start position:0% +okay so I'm the verifier what do I do I +need to verify the sum checks who do I + + align:start position:0% +need to verify the sum checks who do I + + + align:start position:0% +need to verify the sum checks who do I +interact with Su checks I'll put all the + + align:start position:0% +interact with Su checks I'll put all the + + + align:start position:0% +interact with Su checks I'll put all the +possible answers in the Oracle so now we + + align:start position:0% +possible answers in the Oracle so now we + + + align:start position:0% +possible answers in the Oracle so now we +do two DM checks okay so okay so for + + align:start position:0% +do two DM checks okay so okay so for + + + align:start position:0% +do two DM checks okay so okay so for +every pass possible for okay for every + + align:start position:0% + + + + align:start position:0% + +ey and for every + + align:start position:0% +ey and for every + + + align:start position:0% +ey and for every +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Z in the GTR protocol we may need to do + + align:start position:0% +Z in the GTR protocol we may need to do + + + align:start position:0% +Z in the GTR protocol we may need to do +a sum check because in the sum Che + + align:start position:0% +a sum check because in the sum Che + + + align:start position:0% +a sum check because in the sum Che +protocol what is in the GK what does it + + align:start position:0% +protocol what is in the GK what does it + + + align:start position:0% +protocol what is in the GK what does it +how does it look like the ver the + + align:start position:0% +how does it look like the ver the + + + align:start position:0% +how does it look like the ver the +verifier first decides okay prove the + + align:start position:0% +verifier first decides okay prove the + + + align:start position:0% +verifier first decides okay prove the +output layer is correct let's say the + + align:start position:0% +output layer is correct let's say the + + + align:start position:0% +output layer is correct let's say the +output the Z is fixed fine then he + + align:start position:0% +output the Z is fixed fine then he + + + align:start position:0% +output the Z is fixed fine then he +chooses Randomness Randomness Randomness + + align:start position:0% +chooses Randomness Randomness Randomness + + + align:start position:0% +chooses Randomness Randomness Randomness +in a some check it reduces is the + + align:start position:0% +in a some check it reduces is the + + + align:start position:0% +in a some check it reduces is the +checking Z D minus one in a random + + align:start position:0% +checking Z D minus one in a random + + + align:start position:0% +checking Z D minus one in a random +Z the the Z is determined by the random + + align:start position:0% +Z the the Z is determined by the random + + + align:start position:0% +Z the the Z is determined by the random +coins of the + + align:start position:0% +coins of the + + + align:start position:0% +coins of the +verifier so which Z do I put and I want + + align:start position:0% +verifier so which Z do I put and I want + + + align:start position:0% +verifier so which Z do I put and I want +to show something for every possible Z + + align:start position:0% +to show something for every possible Z + + + align:start position:0% +to show something for every possible Z +so for every possible I for every + + align:start position:0% +so for every possible I for every + + + align:start position:0% +so for every possible I for every +possible Z I'm going to put in the PCP a + + align:start position:0% +possible Z I'm going to put in the PCP a + + + align:start position:0% +possible Z I'm going to put in the PCP a +sum check a sum check so I'm going to + + align:start position:0% +sum check a sum check so I'm going to + + + align:start position:0% +sum check a sum check so I'm going to +give a a su check I'm going to add kind + + align:start position:0% +give a a su check I'm going to add kind + + + align:start position:0% +give a a su check I'm going to add kind +of all the possible + + align:start position:0% + + + + align:start position:0% + +transcript for some check corresponding + + align:start position:0% +transcript for some check corresponding + + + align:start position:0% +transcript for some check corresponding +to + + align:start position:0% +to + + + align:start position:0% +to +VI which VI + + align:start position:0% +VI which VI + + + align:start position:0% +VI which VI +Z or maybe to v i equals VI till the Z + + align:start position:0% +Z or maybe to v i equals VI till the Z + + + align:start position:0% +Z or maybe to v i equals VI till the Z +so for every I and Z I'm going to give a + + align:start position:0% +so for every I and Z I'm going to give a + + + align:start position:0% +so for every I and Z I'm going to give a +some + + align:start position:0% +some + + + align:start position:0% +some +check with respect + + align:start position:0% +check with respect + + + align:start position:0% +check with respect +to Randomness R from the from the + + align:start position:0% +to Randomness R from the from the + + + align:start position:0% +to Randomness R from the from the +verifier so for every I for every Z and + + align:start position:0% +verifier so for every I for every Z and + + + align:start position:0% +verifier so for every I for every Z and +for any Randomness R of the verifier now + + align:start position:0% +for any Randomness R of the verifier now + + + align:start position:0% +for any Randomness R of the verifier now +what is how much Randomness that the + + align:start position:0% +what is how much Randomness that the + + + align:start position:0% +what is how much Randomness that the +verifier use in a sum check protocol so + + align:start position:0% +verifier use in a sum check protocol so + + + align:start position:0% +verifier use in a sum check protocol so +remember the sum check is sum over H to + + align:start position:0% +remember the sum check is sum over H to + + + align:start position:0% +remember the sum check is sum over H to +the 3M kind of variables okay sum over p + + align:start position:0% +the 3M kind of variables okay sum over p + + + align:start position:0% +the 3M kind of variables okay sum over p +p W1 W2 all of them in h to the m so the + + align:start position:0% +p W1 W2 all of them in h to the m so the + + + align:start position:0% +p W1 W2 all of them in h to the m so the +r is going to be for every R in F to the + + align:start position:0% +r is going to be for every R in F to the + + + align:start position:0% +r is going to be for every R in F to the +3M because in the subject protocol what + + align:start position:0% +3M because in the subject protocol what + + + align:start position:0% +3M because in the subject protocol what +you do is every single H you every + + align:start position:0% +you do is every single H you every + + + align:start position:0% +you do is every single H you every +single kind of uh you have three M + + align:start position:0% +single kind of uh you have three M + + + align:start position:0% +single kind of uh you have three M +variables every one you give a random + + align:start position:0% +variables every one you give a random + + + align:start position:0% +variables every one you give a random +field element to kind of reduce get rid + + align:start position:0% +field element to kind of reduce get rid + + + align:start position:0% +field element to kind of reduce get rid +of one of the sums so the verifier will + + align:start position:0% +of one of the sums so the verifier will + + + align:start position:0% +of one of the sums so the verifier will +use will choose kind of R1 up to + + align:start position:0% +use will choose kind of R1 up to + + + align:start position:0% +use will choose kind of R1 up to +r3m so 3M field + + align:start position:0% +r3m so 3M field + + + align:start position:0% +r3m so 3M field +elements so for every Poss for for every + + align:start position:0% +elements so for every Poss for for every + + + align:start position:0% +elements so for every Poss for for every +hour I'm going to actually give you the + + align:start position:0% +hour I'm going to actually give you the + + + align:start position:0% +hour I'm going to actually give you the +transcript so now I know I'm going to + + align:start position:0% +transcript so now I know I'm going to + + + align:start position:0% +transcript so now I know I'm going to +give you the entire + + align:start position:0% + + + + align:start position:0% + +transcript okay but here's the thing I + + align:start position:0% +transcript okay but here's the thing I + + + align:start position:0% +transcript okay but here's the thing I +so I'm gonna have a su check for for all + + align:start position:0% +so I'm gonna have a su check for for all + + + align:start position:0% +so I'm gonna have a su check for for all +of them and now the verifier okay but we + + align:start position:0% +of them and now the verifier okay but we + + + align:start position:0% +of them and now the verifier okay but we +need to be careful we don't just give + + align:start position:0% +need to be careful we don't just give + + + align:start position:0% +need to be careful we don't just give +for every R subject if I knew R I would + + align:start position:0% +for every R subject if I knew R I would + + + align:start position:0% +for every R subject if I knew R I would +cheat so what I what what I mean here is + + align:start position:0% +cheat so what I what what I mean here is + + + align:start position:0% +cheat so what I what what I mean here is +for every Su check for every Z + + align:start position:0% +for every Su check for every Z + + + align:start position:0% +for every Su check for every Z +VI for every our so so uh for every + + align:start position:0% +VI for every our so so uh for every + + + align:start position:0% +VI for every our so so uh for every +R1 I'm going to give all the outputs for + + align:start position:0% +R1 I'm going to give all the outputs for + + + align:start position:0% +R1 I'm going to give all the outputs for +R1 like all the kind of answers of the + + align:start position:0% +R1 like all the kind of answers of the + + + align:start position:0% +R1 like all the kind of answers of the +Su check for R1 then for each one of + + align:start position:0% +Su check for R1 then for each one of + + + align:start position:0% +Su check for R1 then for each one of +them for every R2 I have all the + + align:start position:0% +them for every R2 I have all the + + + align:start position:0% +them for every R2 I have all the +possible answers so no competition you + + align:start position:0% +possible answers so no competition you + + + align:start position:0% +possible answers so no competition you +can't have two different element you + + align:start position:0% +can't have two different element you + + + align:start position:0% +can't have two different element you +can't have one value if you had R1 R2 + + align:start position:0% +can't have one value if you had R1 R2 + + + align:start position:0% +can't have one value if you had R1 R2 +but later different RS or R1 R2 it for + + align:start position:0% +but later different RS or R1 R2 it for + + + align:start position:0% +but later different RS or R1 R2 it for +every for every possible partial + + align:start position:0% +every for every possible partial + + + align:start position:0% +every for every possible partial +transcript you give a value that's what + + align:start position:0% +transcript you give a value that's what + + + align:start position:0% +transcript you give a value that's what +the PCP has in it okay so for every so + + align:start position:0% +the PCP has in it okay so for every so + + + align:start position:0% +the PCP has in it okay so for every so +yeah I should say yeah so for every eye + + align:start position:0% +yeah I should say yeah so for every eye + + + align:start position:0% +yeah I should say yeah so for every eye +for every Z and for every maybe I should + + align:start position:0% +for every Z and for every maybe I should + + + align:start position:0% +for every Z and for every maybe I should +write it + + align:start position:0% +write it + + + align:start position:0% +write it +as R1 up to + + align:start position:0% +as R1 up to + + + align:start position:0% +as R1 up to +r3m I have a + + align:start position:0% +r3m I have a + + + align:start position:0% +r3m I have a +transcript all the part I I should have + + align:start position:0% +transcript all the part I I should have + + + align:start position:0% +transcript all the part I I should have +all all + + align:start position:0% +all all + + + align:start position:0% +all all +partial + + align:start position:0% + + + + align:start position:0% + +transcripts of sum + + align:start position:0% +transcripts of sum + + + align:start position:0% +transcripts of sum +check with with respect to VI IAL v + + align:start position:0% +check with with respect to VI IAL v + + + align:start position:0% +check with with respect to VI IAL v +z and + + align:start position:0% +z and + + + align:start position:0% +z and +Randomness no R1 up to RJ for every + + align:start position:0% + + + + align:start position:0% + +J okay between uh I don't know + + align:start position:0% +J okay between uh I don't know + + + align:start position:0% +J okay between uh I don't know +one and 3 + + align:start position:0% + + + + align:start position:0% + +m okay so for every for every for every + + align:start position:0% +m okay so for every for every for every + + + align:start position:0% +m okay so for every for every for every +I for every R1 I will say what would be + + align:start position:0% +I for every R1 I will say what would be + + + align:start position:0% +I for every R1 I will say what would be +my answer so now I have F to the m + + align:start position:0% +my answer so now I have F to the m + + + align:start position:0% +my answer so now I have F to the m +answers for every one of these answers + + align:start position:0% +answers for every one of these answers + + + align:start position:0% +answers for every one of these answers +for every R2 I'm going to tell you what + + align:start position:0% +for every R2 I'm going to tell you what + + + align:start position:0% +for every R2 I'm going to tell you what +is the answer for + + align:start position:0% +is the answer for + + + align:start position:0% +is the answer for +every sorry I I said I said it wrong for + + align:start position:0% +every sorry I I said I said it wrong for + + + align:start position:0% +every sorry I I said I said it wrong for +every R1 I would give all the answer I + + align:start position:0% +every R1 I would give all the answer I + + + align:start position:0% +every R1 I would give all the answer I +have F each one each one is one field so + + align:start position:0% +have F each one each one is one field so + + + align:start position:0% +have F each one each one is one field so +for every R1 I'll tell you the answer + + align:start position:0% +for every R1 I'll tell you the answer + + + align:start position:0% +for every R1 I'll tell you the answer +that's F options because there are F + + align:start position:0% +that's F options because there are F + + + align:start position:0% +that's F options because there are F +options for R1 and then out of these f + + align:start position:0% +options for R1 and then out of these f + + + align:start position:0% +options for R1 and then out of these f +for each of these FS for every R2 I'm + + align:start position:0% +for each of these FS for every R2 I'm + + + align:start position:0% +for each of these FS for every R2 I'm +going to give you what the prover will + + align:start position:0% +going to give you what the prover will + + + align:start position:0% +going to give you what the prover will +send that F that's f squ and then for + + align:start position:0% +send that F that's f squ and then for + + + align:start position:0% +send that F that's f squ and then for +each of these I'm going to give you R3 + + align:start position:0% +each of these I'm going to give you R3 + + + align:start position:0% +each of these I'm going to give you R3 +so really what this PCP for every VI for + + align:start position:0% +so really what this PCP for every VI for + + + align:start position:0% +so really what this PCP for every VI for +every such VI or for every kind of v i + + align:start position:0% +every such VI or for every kind of v i + + + align:start position:0% +every such VI or for every kind of v i +z for every possible R1 I'm going to + + align:start position:0% +z for every possible R1 I'm going to + + + align:start position:0% +z for every possible R1 I'm going to +give you this is over R1 I'm going to + + align:start position:0% +give you this is over R1 I'm going to + + + align:start position:0% +give you this is over R1 I'm going to +give you the possible answers in the sum + + align:start position:0% +give you the possible answers in the sum + + + align:start position:0% +give you the possible answers in the sum +check protocol like if the pro in the Su + + align:start position:0% +check protocol like if the pro in the Su + + + align:start position:0% +check protocol like if the pro in the Su +if the verer in the sum check protocol + + align:start position:0% +if the verer in the sum check protocol + + + align:start position:0% +if the verer in the sum check protocol +the first Randomness was this R1 this R1 + + align:start position:0% +the first Randomness was this R1 this R1 + + + align:start position:0% +the first Randomness was this R1 this R1 +this R1 I'm going to write all of these + + align:start position:0% +this R1 I'm going to write all of these + + + align:start position:0% +this R1 I'm going to write all of these +in the PCP and then for each R1 and + + align:start position:0% +in the PCP and then for each R1 and + + + align:start position:0% +in the PCP and then for each R1 and +every possible R2 I'm going to write my + + align:start position:0% +every possible R2 I'm going to write my + + + align:start position:0% +every possible R2 I'm going to write my +answers and then for each R1 R2 for + + align:start position:0% +answers and then for each R1 R2 for + + + align:start position:0% +answers and then for each R1 R2 for +every possible R3 I'm going to write my + + align:start position:0% +every possible R3 I'm going to write my + + + align:start position:0% +every possible R3 I'm going to write my +answers it seems like an exponential + + align:start position:0% +answers it seems like an exponential + + + align:start position:0% +answers it seems like an exponential +tree and it is an exponential tree but + + align:start position:0% +tree and it is an exponential tree but + + + align:start position:0% +tree and it is an exponential tree but +that the depth is so small so this is a + + align:start position:0% +that the depth is so small so this is a + + + align:start position:0% +that the depth is so small so this is a +huge tree but this tree is only of size + + align:start position:0% +huge tree but this tree is only of size + + + align:start position:0% +huge tree but this tree is only of size +F to the m or to the 3M + + align:start position:0% +F to the m or to the 3M + + + align:start position:0% +F to the m or to the 3M +sorry which is polinomial it's it's uh s + + align:start position:0% +sorry which is polinomial it's it's uh s + + + align:start position:0% +sorry which is polinomial it's it's uh s +to the 3 and you're right that you know + + align:start position:0% +to the 3 and you're right that you know + + + align:start position:0% +to the 3 and you're right that you know +this is not good enough for practice but + + align:start position:0% +this is not good enough for practice but + + + align:start position:0% +this is not good enough for practice but +uh + + align:start position:0% +uh + + + align:start position:0% +uh +then there's a lot of optimizations on + + align:start position:0% +then there's a lot of optimizations on + + + align:start position:0% +then there's a lot of optimizations on +the gkr that make it quasi linear and + + align:start position:0% +the gkr that make it quasi linear and + + + align:start position:0% +the gkr that make it quasi linear and +today even linear so you can actually + + align:start position:0% +today even linear so you can actually + + + align:start position:0% +today even linear so you can actually +optimize this to get uh you know uh + + align:start position:0% +optimize this to get uh you know uh + + + align:start position:0% +optimize this to get uh you know uh +linear time but uh but or uh but or + + align:start position:0% +linear time but uh but or uh but or + + + align:start position:0% +linear time but uh but or uh but or +quasi linear as a PCP but but for now we + + align:start position:0% +quasi linear as a PCP but but for now we + + + align:start position:0% +quasi linear as a PCP but but for now we +don't care about these a polinomial is + + align:start position:0% +don't care about these a polinomial is + + + align:start position:0% +don't care about these a polinomial is +good enough for + + align:start position:0% +good enough for + + + align:start position:0% +good enough for +us okay so for every I and for every Z + + align:start position:0% +us okay so for every I and for every Z + + + align:start position:0% +us okay so for every I and for every Z +we give this + + align:start position:0% +we give this + + + align:start position:0% +we give this +tree that's the + + align:start position:0% + + + + align:start position:0% + +PTP that's it + + align:start position:0% + + + + align:start position:0% + +okay so again + + align:start position:0% + + + + align:start position:0% + +yeah good good good good good fantastic + + align:start position:0% +yeah good good good good good fantastic + + + align:start position:0% +yeah good good good good good fantastic +you're like wait that's a problem do we + + align:start position:0% +you're like wait that's a problem do we + + + align:start position:0% +you're like wait that's a problem do we +if I require F to be small do we even + + align:start position:0% +if I require F to be small do we even + + + align:start position:0% +if I require F to be small do we even +get soundness that's a great question so + + align:start position:0% +get soundness that's a great question so + + + align:start position:0% +get soundness that's a great question so +the answer is barely but yes so let's + + align:start position:0% +the answer is barely but yes so let's + + + align:start position:0% +the answer is barely but yes so let's +see what's the okay what is the + + align:start position:0% +see what's the okay what is the + + + align:start position:0% +see what's the okay what is the +soundness that we get for to be sound + + align:start position:0% +soundness that we get for to be sound + + + align:start position:0% +soundness that we get for to be sound +each Su check so the the okay so let's + + align:start position:0% +each Su check so the the okay so let's + + + align:start position:0% +each Su check so the the okay so let's +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +soundness maybe I'll put it + + align:start position:0% + + + + align:start position:0% + +here let's talk about soundness here for + + align:start position:0% +here let's talk about soundness here for + + + align:start position:0% +here let's talk about soundness here for +a second because you rais a very but you + + align:start position:0% +a second because you rais a very but you + + + align:start position:0% +a second because you rais a very but you +know what actually before we talk about + + align:start position:0% +know what actually before we talk about + + + align:start position:0% +know what actually before we talk about +soundness I I'll jump to soundness you + + align:start position:0% +soundness I I'll jump to soundness you + + + align:start position:0% +soundness I I'll jump to soundness you +have a very good point I'll we'll talk + + align:start position:0% +have a very good point I'll we'll talk + + + align:start position:0% +have a very good point I'll we'll talk +about soundness but just to make sure + + align:start position:0% +about soundness but just to make sure + + + align:start position:0% +about soundness but just to make sure +the construction is clear okay so let me + + align:start position:0% +the construction is clear okay so let me + + + align:start position:0% +the construction is clear okay so let me +just reiterate one last time I'm a PCP + + align:start position:0% +just reiterate one last time I'm a PCP + + + align:start position:0% +just reiterate one last time I'm a PCP +prover I want to convince you guys that + + align:start position:0% +prover I want to convince you guys that + + + align:start position:0% +prover I want to convince you guys that +I have a satisfying assignment to a + + align:start position:0% +I have a satisfying assignment to a + + + align:start position:0% +I have a satisfying assignment to a +threat formula I have my w what I do I + + align:start position:0% +threat formula I have my w what I do I + + + align:start position:0% +threat formula I have my w what I do I +construct low deegree extension of my w + + align:start position:0% +construct low deegree extension of my w + + + align:start position:0% +construct low deegree extension of my w +my witness but also I have this entire + + align:start position:0% +my witness but also I have this entire + + + align:start position:0% +my witness but also I have this entire +circuit that verifies this witness and + + align:start position:0% +circuit that verifies this witness and + + + align:start position:0% +circuit that verifies this witness and +I'm going to construct a low degree + + align:start position:0% +I'm going to construct a low degree + + + align:start position:0% +I'm going to construct a low degree +extension of each and every layer in + + align:start position:0% +extension of each and every layer in + + + align:start position:0% +extension of each and every layer in +this circuit now the way I wrote it + + align:start position:0% +this circuit now the way I wrote it + + + align:start position:0% +this circuit now the way I wrote it +actually I will construct a low degree + + align:start position:0% +actually I will construct a low degree + + + align:start position:0% +actually I will construct a low degree +extension of X and W that's kind of if I + + align:start position:0% +extension of X and W that's kind of if I + + + align:start position:0% +extension of X and W that's kind of if I +think of the input as X and W I need the + + align:start position:0% +think of the input as X and W I need the + + + align:start position:0% +think of the input as X and W I need the +constru L degree extension of both but + + align:start position:0% +constru L degree extension of both but + + + align:start position:0% +constru L degree extension of both but +you the verifying Knows X so if I + + align:start position:0% +you the verifying Knows X so if I + + + align:start position:0% +you the verifying Knows X so if I +construct a low degree extension of w he + + align:start position:0% +construct a low degree extension of w he + + + align:start position:0% +construct a low degree extension of w he +himself can construct a low extension of + + align:start position:0% +himself can construct a low extension of + + + align:start position:0% +himself can construct a low extension of +X and W together so in the PCP because I + + align:start position:0% +X and W together so in the PCP because I + + + align:start position:0% +X and W together so in the PCP because I +don't want to in the PCP I don't want to + + align:start position:0% +don't want to in the PCP I don't want to + + + align:start position:0% +don't want to in the PCP I don't want to +put X in there the verifier has X and if + + align:start position:0% +put X in there the verifier has X and if + + + align:start position:0% +put X in there the verifier has X and if +I have the freedom to put X in there and + + align:start position:0% +I have the freedom to put X in there and + + + align:start position:0% +I have the freedom to put X in there and +you don't read it then I can put the + + align:start position:0% +you don't read it then I can put the + + + align:start position:0% +you don't read it then I can put the +wrong X so I'm just going to put + + align:start position:0% +wrong X so I'm just going to put + + + align:start position:0% +wrong X so I'm just going to put +v0 is just going to + + align:start position:0% +v0 is just going to + + + align:start position:0% +v0 is just going to +be of the witness I'm going to think of + + align:start position:0% +be of the witness I'm going to think of + + + align:start position:0% +be of the witness I'm going to think of +X as fixed so I'm just going to + + align:start position:0% +X as fixed so I'm just going to + + + align:start position:0% +X as fixed so I'm just going to +construct the loading extension of W and + + align:start position:0% +construct the loading extension of W and + + + align:start position:0% +construct the loading extension of W and +then I'm going to construct the low + + align:start position:0% +then I'm going to construct the low + + + align:start position:0% +then I'm going to construct the low +degree extension of each and every layer + + align:start position:0% +degree extension of each and every layer + + + align:start position:0% +degree extension of each and every layer +of the of the + + align:start position:0% +of the of the + + + align:start position:0% +of the of the +circuit and I'm going to go for every + + align:start position:0% +circuit and I'm going to go for every + + + align:start position:0% +circuit and I'm going to go for every +layer and for every Z I'm going to + + align:start position:0% +layer and for every Z I'm going to + + + align:start position:0% +layer and for every Z I'm going to +construct all the + + align:start position:0% +construct all the + + + align:start position:0% +construct all the +possible Pro messages in the Su protocol + + align:start position:0% +possible Pro messages in the Su protocol + + + align:start position:0% +possible Pro messages in the Su protocol +now because the randomness the options + + align:start position:0% +now because the randomness the options + + + align:start position:0% +now because the randomness the options +for the for the uh the number of + + align:start position:0% +for the for the uh the number of + + + align:start position:0% +for the for the uh the number of +possible random bits for the from the + + align:start position:0% +possible random bits for the from the + + + align:start position:0% +possible random bits for the from the +verifier is only F to the 3M because + + align:start position:0% +verifier is only F to the 3M because + + + align:start position:0% +verifier is only F to the 3M because +there's 3M + + align:start position:0% +there's 3M + + + align:start position:0% +there's 3M +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a variables and F is the field so it's + + align:start position:0% +a variables and F is the field so it's + + + align:start position:0% +a variables and F is the field so it's +only F to the + + align:start position:0% +only F to the + + + align:start position:0% +only F to the +3M then this tree is only going to be of + + align:start position:0% +3M then this tree is only going to be of + + + align:start position:0% +3M then this tree is only going to be of +size after the 3M so it's not too + + align:start position:0% +size after the 3M so it's not too + + + align:start position:0% +size after the 3M so it's not too +bad and I put all of them I put all the + + align:start position:0% +bad and I put all of them I put all the + + + align:start position:0% +bad and I put all of them I put all the +possible Su checks in there so sorry + + align:start position:0% +possible Su checks in there so sorry + + + align:start position:0% +possible Su checks in there so sorry +it's F to the 3M for every I have this + + align:start position:0% +it's F to the 3M for every I have this + + + align:start position:0% +it's F to the 3M for every I have this +size for every I and for every Z okay so + + align:start position:0% +size for every I and for every Z okay so + + + align:start position:0% +size for every I and for every Z okay so +for every I I is only D this is small + + align:start position:0% +for every I I is only D this is small + + + align:start position:0% +for every I I is only D this is small +and Z is another F to them I pay fine so + + align:start position:0% +and Z is another F to them I pay fine so + + + align:start position:0% +and Z is another F to them I pay fine so +after to the + + align:start position:0% +after to the + + + align:start position:0% +after to the +4M okay so for every Z and for every I I + + align:start position:0% +4M okay so for every Z and for every I I + + + align:start position:0% +4M okay so for every Z and for every I I +have the sum + + align:start position:0% +have the sum + + + align:start position:0% +have the sum +check now what the what is so that's + + align:start position:0% +check now what the what is so that's + + + align:start position:0% +check now what the what is so that's +that's the PCP but now what's what does + + align:start position:0% +that's the PCP but now what's what does + + + align:start position:0% +that's the PCP but now what's what does +the verifier do what does v I need to + + align:start position:0% +the verifier do what does v I need to + + + align:start position:0% +the verifier do what does v I need to +Define I told you how to construct this + + align:start position:0% +Define I told you how to construct this + + + align:start position:0% +Define I told you how to construct this +Pi efficiently and it's uh but what does + + align:start position:0% +Pi efficiently and it's uh but what does + + + align:start position:0% +Pi efficiently and it's uh but what does +v do so what does what V + + align:start position:0% +v do so what does what V + + + align:start position:0% +v do so what does what V +does he says I'm going to pretend that + + align:start position:0% +does he says I'm going to pretend that + + + align:start position:0% +does he says I'm going to pretend that +I'm I'm interacting with the gkr prover + + align:start position:0% +I'm I'm interacting with the gkr prover + + + align:start position:0% +I'm I'm interacting with the gkr prover +so he says look what is out he's going + + align:start position:0% +so he says look what is out he's going + + + align:start position:0% +so he says look what is out he's going +to read the output + + align:start position:0% +to read the output + + + align:start position:0% +to read the output +VD and he's going to expect a one if he + + align:start position:0% +VD and he's going to expect a one if he + + + align:start position:0% +VD and he's going to expect a one if he +sees a zero so that's one query I'm + + align:start position:0% +sees a zero so that's one query I'm + + + align:start position:0% +sees a zero so that's one query I'm +going to read the output is it's one + + align:start position:0% +going to read the output is it's one + + + align:start position:0% +going to read the output is it's one +good I'm happy okay now he's going to go + + align:start position:0% +good I'm happy okay now he's going to go + + + align:start position:0% +good I'm happy okay now he's going to go +from verifying D to verifying D minus + + align:start position:0% +from verifying D to verifying D minus + + + align:start position:0% +from verifying D to verifying D minus +one D minus 2 D minus 3 now he he wants + + align:start position:0% +one D minus 2 D minus 3 now he he wants + + + align:start position:0% +one D minus 2 D minus 3 now he he wants +to talk to aover he said okay here's my + + align:start position:0% +to talk to aover he said okay here's my + + + align:start position:0% +to talk to aover he said okay here's my +Randomness my first message in the sum + + align:start position:0% +Randomness my first message in the sum + + + align:start position:0% +Randomness my first message in the sum +check give me back something okay he + + align:start position:0% +check give me back something okay he + + + align:start position:0% +check give me back something okay he +this is the approver the Prov is fixed + + align:start position:0% +this is the approver the Prov is fixed + + + align:start position:0% +this is the approver the Prov is fixed +in the PCP okay so he gets back an + + align:start position:0% +in the PCP okay so he gets back an + + + align:start position:0% +in the PCP okay so he gets back an +answer good now here these at the end + + align:start position:0% +answer good now here these at the end + + + align:start position:0% +answer good now here these at the end +this defines V IUS one Z this this + + align:start position:0% +this defines V IUS one Z this this + + + align:start position:0% +this defines V IUS one Z this this +should be all kind of uh elements in V + + align:start position:0% +should be all kind of uh elements in V + + + align:start position:0% +should be all kind of uh elements in V +minus one Z now actually here what you + + align:start position:0% +minus one Z now actually here what you + + + align:start position:0% +minus one Z now actually here what you +have here is at the end of the gkr + + align:start position:0% +have here is at the end of the gkr + + + align:start position:0% +have here is at the end of the gkr +protocol you're left with two two two V + + align:start position:0% +protocol you're left with two two two V + + + align:start position:0% +protocol you're left with two two two V +two v's right so if you verify here + + align:start position:0% +two v's right so if you verify here + + + align:start position:0% +two v's right so if you verify here +you'll have like at the end you'll have + + align:start position:0% +you'll have like at the end you'll have + + + align:start position:0% +you'll have like at the end you'll have +like V I don't know zero and v z z0 and + + align:start position:0% +like V I don't know zero and v z z0 and + + + align:start position:0% +like V I don't know zero and v z z0 and +Z1 you know you'll verify you need to + + align:start position:0% +Z1 you know you'll verify you need to + + + align:start position:0% +Z1 you know you'll verify you need to +verify two points because we did two + + align:start position:0% +verify two points because we did two + + + align:start position:0% +verify two points because we did two +something called ways so fine he sees + + align:start position:0% +something called ways so fine he sees + + + align:start position:0% +something called ways so fine he sees +these two he checks there's these he + + align:start position:0% +these two he checks there's these he + + + align:start position:0% +these two he checks there's these he +checks that they're equal this is only + + align:start position:0% +checks that they're equal this is only + + + align:start position:0% +checks that they're equal this is only +one okay so we're giving him all the low + + align:start position:0% +one okay so we're giving him all the low + + + align:start position:0% +one okay so we're giving him all the low +degree extension of VI minus one he + + align:start position:0% +degree extension of VI minus one he + + + align:start position:0% +degree extension of VI minus one he +checks oh yeah this is corresponds this + + align:start position:0% +checks oh yeah this is corresponds this + + + align:start position:0% +checks oh yeah this is corresponds this +corresponds this is just to ensure that + + align:start position:0% +corresponds this is just to ensure that + + + align:start position:0% +corresponds this is just to ensure that +he doesn't put different ones in + + align:start position:0% +he doesn't put different ones in + + + align:start position:0% +he doesn't put different ones in +different you know here he may uh you + + align:start position:0% +different you know here he may uh you + + + align:start position:0% +different you know here he may uh you +know and in this Branch he may put the + + align:start position:0% +know and in this Branch he may put the + + + align:start position:0% +know and in this Branch he may put the +value of z0 to be something and in this + + align:start position:0% +value of z0 to be something and in this + + + align:start position:0% +value of z0 to be something and in this +Branch you may put the value of z0 to be + + align:start position:0% +Branch you may put the value of z0 to be + + + align:start position:0% +Branch you may put the value of z0 to be +something else that's + + align:start position:0% +something else that's + + + align:start position:0% +something else that's +that's not not good for us so we just + + align:start position:0% +that's not not good for us so we just + + + align:start position:0% +that's not not good for us so we just +check because he put aside all the low + + align:start position:0% +check because he put aside all the low + + + align:start position:0% +check because he put aside all the low +degree extensions so we check that it's + + align:start position:0% +degree extensions so we check that it's + + + align:start position:0% +degree extensions so we check that it's +equal to what he gave us and we continue + + align:start position:0% +equal to what he gave us and we continue + + + align:start position:0% +equal to what he gave us and we continue +with + + align:start position:0% +with + + + align:start position:0% +with +that okay + + align:start position:0% + + + + align:start position:0% + +um one second actually I'm not sure + + align:start position:0% +um one second actually I'm not sure + + + align:start position:0% +um one second actually I'm not sure +maybe what I said is incorrect I'm not + + align:start position:0% +maybe what I said is incorrect I'm not + + + align:start position:0% +maybe what I said is incorrect I'm not +actually sure that this is a problem + + align:start position:0% +actually sure that this is a problem + + + align:start position:0% +actually sure that this is a problem +even if he gives us different let me + + align:start position:0% +even if he gives us different let me + + + align:start position:0% +even if he gives us different let me +think about it for a + + align:start position:0% +think about it for a + + + align:start position:0% +think about it for a +second + + align:start position:0% + + + + align:start position:0% + +a yeah actually I'm not even sure that + + align:start position:0% +a yeah actually I'm not even sure that + + + align:start position:0% +a yeah actually I'm not even sure that +we need we can just put the Su checks + + align:start position:0% +we need we can just put the Su checks + + + align:start position:0% +we need we can just put the Su checks +even if he gives us even if he gives + + align:start position:0% +even if he gives us even if he gives + + + align:start position:0% +even if he gives us even if he gives +us a + + align:start position:0% + + + + align:start position:0% + +no okay yeah I want to say even if he + + align:start position:0% +no okay yeah I want to say even if he + + + align:start position:0% +no okay yeah I want to say even if he +gives us in this branch and this Branch + + align:start position:0% +gives us in this branch and this Branch + + + align:start position:0% +gives us in this branch and this Branch +different things uh why do we care it's + + align:start position:0% +different things uh why do we care it's + + + align:start position:0% +different things uh why do we care it's +like we run the sum check the sum check + + align:start position:0% +like we run the sum check the sum check + + + align:start position:0% +like we run the sum check the sum check +is sound but we we do care a little bit + + align:start position:0% +is sound but we we do care a little bit + + + align:start position:0% +is sound but we we do care a little bit +because then in the next + + align:start position:0% +because then in the next + + + align:start position:0% +because then in the next +round + + align:start position:0% +round + + + align:start position:0% +round +which let me think you know what I'm not + + align:start position:0% +which let me think you know what I'm not + + + align:start position:0% +which let me think you know what I'm not +actually + + align:start position:0% +actually + + + align:start position:0% +actually +what lay + + align:start position:0% + + + + align:start position:0% + +theand exactly you you let all the verif + + align:start position:0% +theand exactly you you let all the verif + + + align:start position:0% +theand exactly you you let all the verif +so yeah so I don't think actually you + + align:start position:0% +so yeah so I don't think actually you + + + align:start position:0% +so yeah so I don't think actually you +need to give these specific you can just + + align:start position:0% +need to give these specific you can just + + + align:start position:0% +need to give these specific you can just +give give for every VI Tilda you give + + align:start position:0% +give give for every VI Tilda you give + + + align:start position:0% +give give for every VI Tilda you give +but it's the same because you give for + + align:start position:0% +but it's the same because you give for + + + align:start position:0% +but it's the same because you give for +every VI Tilda so actually I think these + + align:start position:0% +every VI Tilda so actually I think these + + + align:start position:0% +every VI Tilda so actually I think these +two are the same so I okay what I I + + align:start position:0% +two are the same so I okay what I I + + + align:start position:0% +two are the same so I okay what I I +guess what I said is uh you know these + + align:start position:0% +guess what I said is uh you know these + + + align:start position:0% +guess what I said is uh you know these +can be maybe V uh VI minus one of z0 + + align:start position:0% +can be maybe V uh VI minus one of z0 + + + align:start position:0% +can be maybe V uh VI minus one of z0 +appears here and it appears here and + + align:start position:0% +appears here and it appears here and + + + align:start position:0% +appears here and it appears here and +they're + + align:start position:0% +they're + + + align:start position:0% +they're +different are we worried we're not + + align:start position:0% +different are we worried we're not + + + align:start position:0% +different are we worried we're not +really worried because it's like you + + align:start position:0% +really worried because it's like you + + + align:start position:0% +really worried because it's like you +think of it it interacts with the prover + + align:start position:0% +think of it it interacts with the prover + + + align:start position:0% +think of it it interacts with the prover +the prover the cheating prover may give + + align:start position:0% +the prover the cheating prover may give + + + align:start position:0% +the prover the cheating prover may give +him different Z here and different Z + + align:start position:0% +him different Z here and different Z + + + align:start position:0% +him different Z here and different Z +here but later the point is later you'll + + align:start position:0% +here but later the point is later you'll + + + align:start position:0% +here but later the point is later you'll +have in VI minus one you'll just + + align:start position:0% +have in VI minus one you'll just + + + align:start position:0% +have in VI minus one you'll just +continue so actually you just need to + + align:start position:0% +continue so actually you just need to + + + align:start position:0% +continue so actually you just need to +give but but but really I think the two + + align:start position:0% +give but but but really I think the two + + + align:start position:0% +give but but but really I think the two +are equivalent so it doesn't really + + align:start position:0% +are equivalent so it doesn't really + + + align:start position:0% +are equivalent so it doesn't really +matter a okay so this is the pp and + + align:start position:0% +matter a okay so this is the pp and + + + align:start position:0% +matter a okay so this is the pp and +that's how you verify and at the end at + + align:start position:0% +that's how you verify and at the end at + + + align:start position:0% +that's how you verify and at the end at +the end of the end of the gkr the + + align:start position:0% +the end of the end of the gkr the + + + align:start position:0% +the end of the end of the gkr the +verifier needs to read the input he + + align:start position:0% +verifier needs to read the input he + + + align:start position:0% +verifier needs to read the input he +needs to check the input and some load + + align:start position:0% +needs to check the input and some load + + + align:start position:0% +needs to check the input and some load +in some locations he doesn't have the + + align:start position:0% +in some locations he doesn't have the + + + align:start position:0% +in some locations he doesn't have the +input but he does because we gave him + + align:start position:0% +input but he does because we gave him + + + align:start position:0% +input but he does because we gave him +the low degree extension of w so once he + + align:start position:0% +the low degree extension of w so once he + + + align:start position:0% +the low degree extension of w so once he +has the low degree extension of w he can + + align:start position:0% +has the low degree extension of w he can + + + align:start position:0% +has the low degree extension of w he can +compute anything uh he so the verifier + + align:start position:0% +compute anything uh he so the verifier + + + align:start position:0% +compute anything uh he so the verifier +needs to + + align:start position:0% +needs to + + + align:start position:0% +needs to +compute a low degree extension of X in W + + align:start position:0% +compute a low degree extension of X in W + + + align:start position:0% +compute a low degree extension of X in W +but any point in the low degree + + align:start position:0% +but any point in the low degree + + + align:start position:0% +but any point in the low degree +extension of X and W is a point in the + + align:start position:0% +extension of X and W is a point in the + + + align:start position:0% +extension of X and W is a point in the +low degree EXT is a sum of points in the + + align:start position:0% +low degree EXT is a sum of points in the + + + align:start position:0% +low degree EXT is a sum of points in the +low degree extension of X and point in + + align:start position:0% +low degree extension of X and point in + + + align:start position:0% +low degree extension of X and point in +the Lo extension of w so every every + + align:start position:0% +the Lo extension of w so every every + + + align:start position:0% +the Lo extension of w so every every +point in the low degree extension of X + + align:start position:0% +point in the low degree extension of X + + + align:start position:0% +point in the low degree extension of X +and W you can write as a weighted sum of + + align:start position:0% +and W you can write as a weighted sum of + + + align:start position:0% +and W you can write as a weighted sum of +a point in the lowre low degree + + align:start position:0% +a point in the lowre low degree + + + align:start position:0% +a point in the lowre low degree +extension of X and a point in the Lo + + align:start position:0% +extension of X and a point in the Lo + + + align:start position:0% +extension of X and a point in the Lo +extension of w so you know once he needs + + align:start position:0% +extension of w so you know once he needs + + + align:start position:0% +extension of w so you know once he needs +to read the point in the Lo extension of + + align:start position:0% +to read the point in the Lo extension of + + + align:start position:0% +to read the point in the Lo extension of +w he has it here so that's all that's + + align:start position:0% +w he has it here so that's all that's + + + align:start position:0% +w he has it here so that's all that's +all the verifier does so he really he's + + align:start position:0% +all the verifier does so he really he's + + + align:start position:0% +all the verifier does so he really he's +it's interesting this PCP he as if he's + + align:start position:0% +it's interesting this PCP he as if he's + + + align:start position:0% +it's interesting this PCP he as if he's +talking to the prover but the prover is + + align:start position:0% +talking to the prover but the prover is + + + align:start position:0% +talking to the prover but the prover is +sitting in the sky in the + + align:start position:0% +sitting in the sky in the + + + align:start position:0% +sitting in the sky in the +PCP the pro strategy just kind of opened + + align:start position:0% +PCP the pro strategy just kind of opened + + + align:start position:0% +PCP the pro strategy just kind of opened +up in in the + + align:start position:0% +up in in the + + + align:start position:0% +up in in the +Oracle okay okay great so now any + + align:start position:0% +Oracle okay okay great so now any + + + align:start position:0% +Oracle okay okay great so now any +questions before we talk about + + align:start position:0% +questions before we talk about + + + align:start position:0% +questions before we talk about +soundness + + align:start position:0% + + + + align:start position:0% + +yeah so right so uh okay good good good + + align:start position:0% +yeah so right so uh okay good good good + + + align:start position:0% +yeah so right so uh okay good good good +good good question the verify great + + align:start position:0% +good good question the verify great + + + align:start position:0% +good good question the verify great +question the verifier needs to check + + align:start position:0% +question the verifier needs to check + + + align:start position:0% +question the verifier needs to check +also that all these things are actually + + align:start position:0% +also that all these things are actually + + + align:start position:0% +also that all these things are actually +low deegree extension okay so what if I + + align:start position:0% +low deegree extension okay so what if I + + + align:start position:0% +low deegree extension okay so what if I +I I said here oh put um you put VI Tilda + + align:start position:0% +I I said here oh put um you put VI Tilda + + + align:start position:0% +I I said here oh put um you put VI Tilda +Z how do I know that you actually put a + + align:start position:0% +Z how do I know that you actually put a + + + align:start position:0% +Z how do I know that you actually put a +low degree extension maybe you put a + + align:start position:0% +low degree extension maybe you put a + + + align:start position:0% +low degree extension maybe you put a +very high degree polinomial there maybe + + align:start position:0% +very high degree polinomial there maybe + + + align:start position:0% +very high degree polinomial there maybe +you just put an arbitrary truth table of + + align:start position:0% +you just put an arbitrary truth table of + + + align:start position:0% +you just put an arbitrary truth table of +size after + + align:start position:0% +size after + + + align:start position:0% +size after +them that would be + + align:start position:0% +them that would be + + + align:start position:0% +them that would be +problematic so you're totally right the + + align:start position:0% +problematic so you're totally right the + + + align:start position:0% +problematic so you're totally right the +verifier so let let me write what the + + align:start position:0% +verifier so let let me write what the + + + align:start position:0% +verifier so let let me write what the +verifier does uh maybe before the sound + + align:start position:0% +verifier does uh maybe before the sound + + + align:start position:0% +verifier does uh maybe before the sound +is yeah + + align:start position:0% + + + + align:start position:0% + +so let me actually write it okay so the + + align:start position:0% +so let me actually write it okay so the + + + align:start position:0% +so let me actually write it okay so the +verifier + + align:start position:0% + + + + align:start position:0% + +okay he + + align:start position:0% +okay he + + + align:start position:0% +okay he +runs first thing he does he runs V of + + align:start position:0% + + + + align:start position:0% + +gkr with its + + align:start position:0% + + + + align:start position:0% + +Oracle okay so he runs the just the gkr + + align:start position:0% +Oracle okay so he runs the just the gkr + + + align:start position:0% +Oracle okay so he runs the just the gkr +but he thinks of kind of the Oracle part + + align:start position:0% +but he thinks of kind of the Oracle part + + + align:start position:0% +but he thinks of kind of the Oracle part +as kind of the the prover he's talking + + align:start position:0% +as kind of the the prover he's talking + + + align:start position:0% +as kind of the the prover he's talking +with and the other thing he needs needs + + align:start position:0% +with and the other thing he needs needs + + + align:start position:0% +with and the other thing he needs needs +to do is he needs to + + align:start position:0% + + + + align:start position:0% + +check that for every + + align:start position:0% +check that for every + + + align:start position:0% +check that for every +I VI + + align:start position:0% +I VI + + + align:start position:0% +I VI +Tilda is of low degree is + + align:start position:0% + + + + align:start position:0% + +doesn't + + align:start position:0% + + + + align:start position:0% + +um yeah what you're saying is that if + + align:start position:0% +um yeah what you're saying is that if + + + align:start position:0% +um yeah what you're saying is that if +you're right so what you're saying is a + + align:start position:0% + + + + align:start position:0% + +okay what you're saying is if he comp If + + align:start position:0% +okay what you're saying is if he comp If + + + align:start position:0% +okay what you're saying is if he comp If +he if he gave VI Tilda that was high + + align:start position:0% + + + + align:start position:0% + +degree then you're saying that GK would + + align:start position:0% +degree then you're saying that GK would + + + align:start position:0% +degree then you're saying that GK would +fail you you would be rejected by the GK + + align:start position:0% +fail you you would be rejected by the GK + + + align:start position:0% +fail you you would be rejected by the GK +should + + align:start position:0% +should + + + align:start position:0% +should +bewi it should be rejected by the GK a + + align:start position:0% + + + + align:start position:0% + +I think you may be right but actually + + align:start position:0% +I think you may be right but actually + + + align:start position:0% +I think you may be right but actually +I'm not 100% sure now + + align:start position:0% +I'm not 100% sure now + + + align:start position:0% +I'm not 100% sure now +uh yeah that + + align:start position:0% + + + + align:start position:0% + +ISE yeah so here's here's the concern + + align:start position:0% +ISE yeah so here's here's the concern + + + align:start position:0% +ISE yeah so here's here's the concern +here's the concern the concern is we + + align:start position:0% +here's the concern the concern is we + + + align:start position:0% +here's the concern the concern is we +want to make sure that the + + align:start position:0% +want to make sure that the + + + align:start position:0% +want to make sure that the +verifier is uh + + align:start position:0% +verifier is uh + + + align:start position:0% +verifier is uh +behaving like that we want to okay we + + align:start position:0% +behaving like that we want to okay we + + + align:start position:0% +behaving like that we want to okay we +want to make sure that this VI Tilda + + align:start position:0% + + + + align:start position:0% + +is of low + + align:start position:0% +is of low + + + align:start position:0% +is of low +degree + + align:start position:0% + + + + align:start position:0% + +why sorry one second + + align:start position:0% + + + + align:start position:0% + +um yeah actually I I + + align:start position:0% + + + + align:start position:0% + +I don't think we need to check that via + + align:start position:0% +I don't think we need to check that via + + + align:start position:0% +I don't think we need to check that via +is a low degree because I I agree that + + align:start position:0% +is a low degree because I I agree that + + + align:start position:0% +is a low degree because I I agree that +we need to check that VI is a low degree + + align:start position:0% +we need to check that VI is a low degree + + + align:start position:0% +we need to check that VI is a low degree +but I think gkr checks that the vi till + + align:start position:0% +but I think gkr checks that the vi till + + + align:start position:0% +but I think gkr checks that the vi till +there's a low degree so I actually don't + + align:start position:0% +there's a low degree so I actually don't + + + align:start position:0% +there's a low degree so I actually don't +want to recheck it so all I want to do + + align:start position:0% +want to recheck it so all I want to do + + + align:start position:0% +want to recheck it so all I want to do +here I think GK test tests it for you so + + align:start position:0% +here I think GK test tests it for you so + + + align:start position:0% +here I think GK test tests it for you so +we're convinced that the gkr is sound + + align:start position:0% +we're convinced that the gkr is sound + + + align:start position:0% +we're convinced that the gkr is sound +let's not recall why it sound but let's + + align:start position:0% +let's not recall why it sound but let's + + + align:start position:0% +let's not recall why it sound but let's +remember we we learned that it sound so + + align:start position:0% +remember we we learned that it sound so + + + align:start position:0% +remember we we learned that it sound so +GK is good now what are we doing I + + align:start position:0% +GK is good now what are we doing I + + + align:start position:0% +GK is good now what are we doing I +essentially what we're saying is + + align:start position:0% +essentially what we're saying is + + + align:start position:0% +essentially what we're saying is +verifier I'm giving you all the possible + + align:start position:0% +verifier I'm giving you all the possible + + + align:start position:0% +verifier I'm giving you all the possible +answers of I'm what is the prover the + + align:start position:0% +answers of I'm what is the prover the + + + align:start position:0% +answers of I'm what is the prover the +prover is a tree you can think what is a + + align:start position:0% +prover is a tree you can think what is a + + + align:start position:0% +prover is a tree you can think what is a +cheating prover a cheating prover for + + align:start position:0% +cheating prover a cheating prover for + + + align:start position:0% +cheating prover a cheating prover for +every possible you know for every + + align:start position:0% +every possible you know for every + + + align:start position:0% +every possible you know for every +possible question he gives you an answer + + align:start position:0% +possible question he gives you an answer + + + align:start position:0% +possible question he gives you an answer +for every question he gives you an + + align:start position:0% +for every question he gives you an + + + align:start position:0% +for every question he gives you an +answer that's what it does so now you're + + align:start position:0% +answer that's what it does so now you're + + + align:start position:0% +answer that's what it does so now you're +saying look I'm going to give you the + + align:start position:0% +saying look I'm going to give you the + + + align:start position:0% +saying look I'm going to give you the +tree now in general this tree is really + + align:start position:0% +tree now in general this tree is really + + + align:start position:0% +tree now in general this tree is really +really big and even in gkr if you give + + align:start position:0% +really big and even in gkr if you give + + + align:start position:0% +really big and even in gkr if you give +the entire if you just open like GK has + + align:start position:0% +the entire if you just open like GK has + + + align:start position:0% +the entire if you just open like GK has +D rounds D rounds of su Che if you just + + align:start position:0% +D rounds D rounds of su Che if you just + + + align:start position:0% +D rounds D rounds of su Che if you just +open the S Che it will be terrible + + align:start position:0% +open the S Che it will be terrible + + + align:start position:0% +open the S Che it will be terrible +however + + align:start position:0% +however + + + align:start position:0% +however +a gkr has this property that it's kind + + align:start position:0% +a gkr has this property that it's kind + + + align:start position:0% +a gkr has this property that it's kind +of memory lless what do I mean by memory + + align:start position:0% +of memory lless what do I mean by memory + + + align:start position:0% +of memory lless what do I mean by memory +list you can compute the first Su check + + align:start position:0% +list you can compute the first Su check + + + align:start position:0% +list you can compute the first Su check +then you don't care what happened before + + align:start position:0% +then you don't care what happened before + + + align:start position:0% +then you don't care what happened before +all you care is what is VI minus one + + align:start position:0% +all you care is what is VI minus one + + + align:start position:0% +all you care is what is VI minus one +that you cut and you check + + align:start position:0% +that you cut and you check + + + align:start position:0% +that you cut and you check +those so now I'm saying so you know + + align:start position:0% +those so now I'm saying so you know + + + align:start position:0% +those so now I'm saying so you know +actually for let's think about this + + align:start position:0% +actually for let's think about this + + + align:start position:0% +actually for let's think about this +first of all we can say open gkr to a + + align:start position:0% +first of all we can say open gkr to a + + + align:start position:0% +first of all we can say open gkr to a +huge tree okay any pro this is true in + + align:start position:0% +huge tree okay any pro this is true in + + + align:start position:0% +huge tree okay any pro this is true in +in general if you had any interactive + + align:start position:0% +in general if you had any interactive + + + align:start position:0% +in general if you had any interactive +proof you can think of a pro write all + + align:start position:0% +proof you can think of a pro write all + + + align:start position:0% +proof you can think of a pro write all +the possible answers like think of its + + align:start position:0% +the possible answers like think of its + + + align:start position:0% +the possible answers like think of its +kind of H strategy as a huge huge tree + + align:start position:0% +kind of H strategy as a huge huge tree + + + align:start position:0% +kind of H strategy as a huge huge tree +right the tree now of course you get + + align:start position:0% +right the tree now of course you get + + + align:start position:0% +right the tree now of course you get +sound this you interact with the + + align:start position:0% +sound this you interact with the + + + align:start position:0% +sound this you interact with the +approver what's the difference okay you + + align:start position:0% +approver what's the difference okay you + + + align:start position:0% +approver what's the difference okay you +can do that with G but of course if you + + align:start position:0% +can do that with G but of course if you + + + align:start position:0% +can do that with G but of course if you +do this huge tree it's going to be + + align:start position:0% +do this huge tree it's going to be + + + align:start position:0% +do this huge tree it's going to be +gigantic because GK consists of d kind + + align:start position:0% +gigantic because GK consists of d kind + + + align:start position:0% +gigantic because GK consists of d kind +of um + + align:start position:0% +of um + + + align:start position:0% +of um +a uh subprotocols each one is a su check + + align:start position:0% +a uh subprotocols each one is a su check + + + align:start position:0% +a uh subprotocols each one is a su check +so now if you think of like a D Cab then + + align:start position:0% +so now if you think of like a D Cab then + + + align:start position:0% +so now if you think of like a D Cab then +you'll be too big but I'm saying we + + align:start position:0% +you'll be too big but I'm saying we + + + align:start position:0% +you'll be too big but I'm saying we +don't need to because gkr has a property + + align:start position:0% +don't need to because gkr has a property + + + align:start position:0% +don't need to because gkr has a property +that actually it consist of this + + align:start position:0% +that actually it consist of this + + + align:start position:0% +that actually it consist of this +subprotocol and then all you need to + + align:start position:0% +subprotocol and then all you need to + + + align:start position:0% +subprotocol and then all you need to +remember you don't need to remember + + align:start position:0% +remember you don't need to remember + + + align:start position:0% +remember you don't need to remember +which branch you're on here all you need + + align:start position:0% +which branch you're on here all you need + + + align:start position:0% +which branch you're on here all you need +to remember is what are the values here + + align:start position:0% +to remember is what are the values here + + + align:start position:0% +to remember is what are the values here +that's all you need to + + align:start position:0% +that's all you need to + + + align:start position:0% +that's all you need to +remember so there's no point in + + align:start position:0% +remember so there's no point in + + + align:start position:0% +remember so there's no point in +repeating it's like you're repeating the + + align:start position:0% +repeating it's like you're repeating the + + + align:start position:0% +repeating it's like you're repeating the +tree for no reason so all you need + + align:start position:0% +tree for no reason so all you need + + + align:start position:0% +tree for no reason so all you need +there's a way to open kind of this Pro + + align:start position:0% +there's a way to open kind of this Pro + + + align:start position:0% +there's a way to open kind of this Pro +in a more efficient + + align:start position:0% +in a more efficient + + + align:start position:0% +in a more efficient +way so by not giving the entire tree and + + align:start position:0% +way so by not giving the entire tree and + + + align:start position:0% +way so by not giving the entire tree and +giving kind of a more efficient kind of + + align:start position:0% +giving kind of a more efficient kind of + + + align:start position:0% +giving kind of a more efficient kind of +opening where all the vi Z all the vi + + align:start position:0% +opening where all the vi Z all the vi + + + align:start position:0% +opening where all the vi Z all the vi +IUS one Z I'm going to say okay forget + + align:start position:0% +IUS one Z I'm going to say okay forget + + + align:start position:0% +IUS one Z I'm going to say okay forget +about it let's just go from VI minus one + + align:start position:0% +about it let's just go from VI minus one + + + align:start position:0% +about it let's just go from VI minus one +Z and continue why do you need to repeat + + align:start position:0% +Z and continue why do you need to repeat + + + align:start position:0% +Z and continue why do you need to repeat +this kind of tree a 100 times it's it's + + align:start position:0% +this kind of tree a 100 times it's it's + + + align:start position:0% +this kind of tree a 100 times it's it's +but it's you can go go from here to kind + + align:start position:0% +but it's you can go go from here to kind + + + align:start position:0% +but it's you can go go from here to kind +of simulating an entire GK + + align:start position:0% + + + + align:start position:0% + +approver yeah if I understand correctly + + align:start position:0% +approver yeah if I understand correctly + + + align:start position:0% +approver yeah if I understand correctly +you're saying like actually the tree of + + align:start position:0% +you're saying like actually the tree of + + + align:start position:0% +you're saying like actually the tree of +gkr is such that most of the parts cof + + align:start position:0% +gkr is such that most of the parts cof + + + align:start position:0% +gkr is such that most of the parts cof +right and so you don't need to repeat + + align:start position:0% +right and so you don't need to repeat + + + align:start position:0% +right and so you don't need to repeat +the copies you can just look it up + + align:start position:0% +the copies you can just look it up + + + align:start position:0% +the copies you can just look it up +exactly exactly + + align:start position:0% +exactly exactly + + + align:start position:0% +exactly exactly +exactly + + align:start position:0% + + + + align:start position:0% + +exactly actually in some sense we're + + align:start position:0% +exactly actually in some sense we're + + + align:start position:0% +exactly actually in some sense we're +restricting the prover here more than + + align:start position:0% +restricting the prover here more than + + + align:start position:0% +restricting the prover here more than +he's restricted in + + align:start position:0% +he's restricted in + + + align:start position:0% +he's restricted in +gkr exactly because in gkr he can be you + + align:start position:0% +gkr exactly because in gkr he can be you + + + align:start position:0% +gkr exactly because in gkr he can be you +know what I'm going to remember the RS + + align:start position:0% +know what I'm going to remember the RS + + + align:start position:0% +know what I'm going to remember the RS +if he's cheating and based on the RS I'm + + align:start position:0% +if he's cheating and based on the RS I'm + + + align:start position:0% +if he's cheating and based on the RS I'm +going to give you a different strategy + + align:start position:0% +going to give you a different strategy + + + align:start position:0% +going to give you a different strategy +whatever here we're not even letting him + + align:start position:0% +whatever here we're not even letting him + + + align:start position:0% +whatever here we're not even letting him +do that we're telling look you tell me + + align:start position:0% +do that we're telling look you tell me + + + align:start position:0% +do that we're telling look you tell me +what you are here from here now you + + align:start position:0% +what you are here from here now you + + + align:start position:0% +what you are here from here now you +forget Ours from VI minus one what's + + align:start position:0% +forget Ours from VI minus one what's + + + align:start position:0% +forget Ours from VI minus one what's +your strategy and now you forget from + + align:start position:0% +your strategy and now you forget from + + + align:start position:0% +your strategy and now you forget from +here what is your + + align:start position:0% +here what is your + + + align:start position:0% +here what is your +strategy so we're really just doing gkr + + align:start position:0% +strategy so we're really just doing gkr + + + align:start position:0% +strategy so we're really just doing gkr +now you're right at the vi minus one do + + align:start position:0% +now you're right at the vi minus one do + + + align:start position:0% +now you're right at the vi minus one do +till they do need to be of low degree + + align:start position:0% +till they do need to be of low degree + + + align:start position:0% +till they do need to be of low degree +but do the Gare test this for you so you + + align:start position:0% +but do the Gare test this for you so you + + + align:start position:0% +but do the Gare test this for you so you +don't need to do it on your + + align:start position:0% +don't need to do it on your + + + align:start position:0% +don't need to do it on your +own but you're right it's confusing a + + align:start position:0% +own but you're right it's confusing a + + + align:start position:0% +own but you're right it's confusing a +little bit because if you if any if + + align:start position:0% +little bit because if you if any if + + + align:start position:0% +little bit because if you if any if +anyone is familiar with the PCP + + align:start position:0% +anyone is familiar with the PCP + + + align:start position:0% +anyone is familiar with the PCP +literature there's always a low deegree + + align:start position:0% +literature there's always a low deegree + + + align:start position:0% +literature there's always a low deegree +test in it so it's kind of interesting + + align:start position:0% +test in it so it's kind of interesting + + + align:start position:0% +test in it so it's kind of interesting +this this kind of is hidden with within + + align:start position:0% +this this kind of is hidden with within + + + align:start position:0% +this this kind of is hidden with within +the Gare + + align:start position:0% +the Gare + + + align:start position:0% +the Gare +protocol this kind of transformation not + + align:start position:0% +protocol this kind of transformation not + + + align:start position:0% +protocol this kind of transformation not +only as as there is efficient way to + + align:start position:0% +only as as there is efficient way to + + + align:start position:0% +only as as there is efficient way to +change the into a sequence that the know + + align:start position:0% +change the into a sequence that the know + + + align:start position:0% +change the into a sequence that the know +where + + align:start position:0% +where + + + align:start position:0% +where +to exactly exactly so yeah this this + + align:start position:0% +to exactly exactly so yeah this this + + + align:start position:0% +to exactly exactly so yeah this this +proof holds it's not specific to gkr + + align:start position:0% +proof holds it's not specific to gkr + + + align:start position:0% +proof holds it's not specific to gkr +it's kind of you can take any sixing + + align:start position:0% +it's kind of you can take any sixing + + + align:start position:0% +it's kind of you can take any sixing +protocol and and interactive protocol + + align:start position:0% +protocol and and interactive protocol + + + align:start position:0% +protocol and and interactive protocol +and lay it open however let me just + + align:start position:0% +and lay it open however let me just + + + align:start position:0% +and lay it open however let me just +mention we have very few actually kind + + align:start position:0% +mention we have very few actually kind + + + align:start position:0% +mention we have very few actually kind +of two examples of suing protocols so it + + align:start position:0% +of two examples of suing protocols so it + + + align:start position:0% +of two examples of suing protocols so it +sound like you can take any of your + + align:start position:0% +sound like you can take any of your + + + align:start position:0% +sound like you can take any of your +choice yeah any but we don't have much + + align:start position:0% +choice yeah any but we don't have much + + + align:start position:0% +choice yeah any but we don't have much +choice so uh you know a coming up with + + align:start position:0% +choice so uh you know a coming up with + + + align:start position:0% +choice so uh you know a coming up with +these succinct interactive proofs is a + + align:start position:0% +these succinct interactive proofs is a + + + align:start position:0% +these succinct interactive proofs is a +super interesting question I'll I'll + + align:start position:0% +super interesting question I'll I'll + + + align:start position:0% +super interesting question I'll I'll +talk a little bit more about this after + + align:start position:0% +talk a little bit more about this after + + + align:start position:0% +talk a little bit more about this after +we do the analysis of the + + align:start position:0% +we do the analysis of the + + + align:start position:0% +we do the analysis of the +PCB okay so great + + align:start position:0% +PCB okay so great + + + align:start position:0% +PCB okay so great +uh any questions before we move to + + align:start position:0% +uh any questions before we move to + + + align:start position:0% +uh any questions before we move to +soundness okay so let's talk about + + align:start position:0% +soundness okay so let's talk about + + + align:start position:0% +soundness okay so let's talk about +soundness and the question that was + + align:start position:0% +soundness and the question that was + + + align:start position:0% +soundness and the question that was +raised which was a great question is + + align:start position:0% +raised which was a great question is + + + align:start position:0% +raised which was a great question is +Wait f needs to be big to get soundness + + align:start position:0% +Wait f needs to be big to get soundness + + + align:start position:0% +Wait f needs to be big to get soundness +so let's really understand what the size + + align:start position:0% +so let's really understand what the size + + + align:start position:0% +so let's really understand what the size +of f needs to be so to get soundness we + + align:start position:0% +of f needs to be so to get soundness we + + + align:start position:0% +of f needs to be so to get soundness we +do 2D Su check + + align:start position:0% +do 2D Su check + + + align:start position:0% +do 2D Su check +protocols each Su check protocol needs + + align:start position:0% +protocols each Su check protocol needs + + + align:start position:0% +protocols each Su check protocol needs +to be pretty sound because it's enough + + align:start position:0% +to be pretty sound because it's enough + + + align:start position:0% +to be pretty sound because it's enough +that you cheat on one of them and we're + + align:start position:0% +that you cheat on one of them and we're + + + align:start position:0% +that you cheat on one of them and we're +dead right + + align:start position:0% +dead right + + + align:start position:0% +dead right +so now each Su Che protocol this is this + + align:start position:0% +so now each Su Che protocol this is this + + + align:start position:0% +so now each Su Che protocol this is this +is just + + align:start position:0% +is just + + + align:start position:0% +is just +recall that + + align:start position:0% +recall that + + + align:start position:0% +recall that +each Su check + + align:start position:0% +each Su check + + + align:start position:0% +each Su check +protocol has sound + + align:start position:0% + + + + align:start position:0% + +is which is + + align:start position:0% +is which is + + + align:start position:0% +is which is +H over F times M the number of variables + + align:start position:0% +H over F times M the number of variables + + + align:start position:0% +H over F times M the number of variables +but for us it's 3M because we have 3M + + align:start position:0% +but for us it's 3M because we have 3M + + + align:start position:0% +but for us it's 3M because we have 3M +variables okay this is just the the each + + align:start position:0% +variables okay this is just the the each + + + align:start position:0% +variables okay this is just the the each +subject protocol now for us so you can + + align:start position:0% +subject protocol now for us so you can + + + align:start position:0% +subject protocol now for us so you can +cheat but with this + + align:start position:0% +cheat but with this + + + align:start position:0% +cheat but with this +probability now for us we have 2D D is + + align:start position:0% +probability now for us we have 2D D is + + + align:start position:0% +probability now for us we have 2D D is +poly Logan like the depth of the circuit + + align:start position:0% +poly Logan like the depth of the circuit + + + align:start position:0% +poly Logan like the depth of the circuit +so for us our sound + + align:start position:0% + + + + align:start position:0% + +is is I'm just doing a union bound so to + + align:start position:0% +is is I'm just doing a union bound so to + + + align:start position:0% +is is I'm just doing a union bound so to +cheat there exist needs to be at least + + align:start position:0% +cheat there exist needs to be at least + + + align:start position:0% +cheat there exist needs to be at least +kind of uh one subject protoc for which + + align:start position:0% +kind of uh one subject protoc for which + + + align:start position:0% +kind of uh one subject protoc for which +you cheated on so you get by Union bound + + align:start position:0% +you cheated on so you get by Union bound + + + align:start position:0% +you cheated on so you get by Union bound +so we have 2D sum checks and then + + align:start position:0% +so we have 2D sum checks and then + + + align:start position:0% +so we have 2D sum checks and then +therefore the + + align:start position:0% + + + + align:start position:0% + +soundness is 2D * 3 m h divided by + + align:start position:0% + + + + align:start position:0% + +F so now if we want sound this half + + align:start position:0% +F so now if we want sound this half + + + align:start position:0% +F so now if we want sound this half +let's say which is what we want after + + align:start position:0% +let's say which is what we want after + + + align:start position:0% +let's say which is what we want after +that you can repeat to increase the + + align:start position:0% +that you can repeat to increase the + + + align:start position:0% +that you can repeat to increase the +soundness all we need is that F so if we + + align:start position:0% +soundness all we need is that F so if we + + + align:start position:0% +soundness all we need is that F so if we +want this to be smaller than + + align:start position:0% +want this to be smaller than + + + align:start position:0% +want this to be smaller than +half then we need F to be bigger than uh + + align:start position:0% +half then we need F to be bigger than uh + + + align:start position:0% +half then we need F to be bigger than uh +12 D + + align:start position:0% +12 D + + + align:start position:0% +12 D +MH but that's good this is log N I don't + + align:start position:0% +MH but that's good this is log N I don't + + + align:start position:0% +MH but that's good this is log N I don't +know if you guys can see H log s sorry + + align:start position:0% +know if you guys can see H log s sorry + + + align:start position:0% +know if you guys can see H log s sorry +this is smaller than log + + align:start position:0% +this is smaller than log + + + align:start position:0% +this is smaller than log +s this is some poly log s okay so just + + align:start position:0% +s this is some poly log s okay so just + + + align:start position:0% +s this is some poly log s okay so just +make it bigger than all of them it's + + align:start position:0% +make it bigger than all of them it's + + + align:start position:0% +make it bigger than all of them it's +still + + align:start position:0% +still + + + align:start position:0% +still +polylog and polylog S is good enough + + align:start position:0% +polylog and polylog S is good enough + + + align:start position:0% +polylog and polylog S is good enough +because then after them is + + align:start position:0% + + + + align:start position:0% + +polys okay so this was sound + + align:start position:0% + + + + align:start position:0% + +is oh oh good why do we need you're + + align:start position:0% +is oh oh good why do we need you're + + + align:start position:0% +is oh oh good why do we need you're +saying why can't it be bigger because + + align:start position:0% +saying why can't it be bigger because + + + align:start position:0% +saying why can't it be bigger because +good because we want our PCP to be of so + + align:start position:0% +good because we want our PCP to be of so + + + align:start position:0% +good because we want our PCP to be of so +the question is just to recap why do we + + align:start position:0% +the question is just to recap why do we + + + align:start position:0% +the question is just to recap why do we +need why do we insist that f is not + + align:start position:0% +need why do we insist that f is not + + + align:start position:0% +need why do we insist that f is not +bigger why does it have to be poom + + align:start position:0% +bigger why does it have to be poom + + + align:start position:0% +bigger why does it have to be poom +related to F and the reason is we want + + align:start position:0% +related to F and the reason is we want + + + align:start position:0% +related to F and the reason is we want +the PCP to beide polys we want the ver + + align:start position:0% +the PCP to beide polys we want the ver + + + align:start position:0% +the PCP to beide polys we want the ver +we want the PCP a to be not we want it + + align:start position:0% +we want the PCP a to be not we want it + + + align:start position:0% +we want the PCP a to be not we want it +to be efficient we want to efficiently + + align:start position:0% +to be efficient we want to efficiently + + + align:start position:0% +to be efficient we want to efficiently +convert a witness to a PCP and the PCP + + align:start position:0% +convert a witness to a PCP and the PCP + + + align:start position:0% +convert a witness to a PCP and the PCP +grows with f to the m much more it's + + align:start position:0% +grows with f to the m much more it's + + + align:start position:0% +grows with f to the m much more it's +like f to the 3M and it needs to be + + align:start position:0% +like f to the 3M and it needs to be + + + align:start position:0% +like f to the 3M and it needs to be +repeated and F to the m is poly so okay + + align:start position:0% +repeated and F to the m is poly so okay + + + align:start position:0% +repeated and F to the m is poly so okay +it's if this is bigger than poly if f is + + align:start position:0% +it's if this is bigger than poly if f is + + + align:start position:0% +it's if this is bigger than poly if f is +more than poly H then F to the m will be + + align:start position:0% +more than poly H then F to the m will be + + + align:start position:0% +more than poly H then F to the m will be +more than poly H to the m so that's why + + align:start position:0% +more than poly H to the m so that's why + + + align:start position:0% +more than poly H to the m so that's why +we want we want it to be it's for the + + align:start position:0% +we want we want it to be it's for the + + + align:start position:0% +we want we want it to be it's for the +sake of efficiency for the for the PCP + + align:start position:0% +sake of efficiency for the for the PCP + + + align:start position:0% +sake of efficiency for the for the PCP +to be small or palomi related to the + + align:start position:0% +to be small or palomi related to the + + + align:start position:0% +to be small or palomi related to the +Circuit um so here you saying that the + + align:start position:0% +Circuit um so here you saying that the + + + align:start position:0% +Circuit um so here you saying that the +randomness complexity is poly now + + align:start position:0% +randomness complexity is poly now + + + align:start position:0% +randomness complexity is poly now +normally you'd be like okay the pro size + + align:start position:0% +normally you'd be like okay the pro size + + + align:start position:0% +normally you'd be like okay the pro size +is just two to the random but You' like + + align:start position:0% +is just two to the random but You' like + + + align:start position:0% +is just two to the random but You' like +more right you found a way to make than + + align:start position:0% +more right you found a way to make than + + + align:start position:0% +more right you found a way to make than +it would be okay good good good so now + + align:start position:0% +it would be okay good good good so now + + + align:start position:0% +it would be okay good good good so now +let's go to the we didn't do the + + align:start position:0% +let's go to the we didn't do the + + + align:start position:0% +let's go to the we didn't do the +complexity yet but yeah you're a bit a + + align:start position:0% +complexity yet but yeah you're a bit a + + + align:start position:0% +complexity yet but yeah you're a bit a +bit ahead of me but you're you're + + align:start position:0% +bit ahead of me but you're you're + + + align:start position:0% +bit ahead of me but you're you're +totally right so now so so far we talked + + align:start position:0% +totally right so now so so far we talked + + + align:start position:0% +totally right so now so so far we talked +about soundness completeness is one + + align:start position:0% +about soundness completeness is one + + + align:start position:0% +about soundness completeness is one +because the G is complete has + + align:start position:0% +because the G is complete has + + + align:start position:0% +because the G is complete has +completeness one so we the Su check has + + align:start position:0% +completeness one so we the Su check has + + + align:start position:0% +completeness one so we the Su check has +completeness one so we're good we talked + + align:start position:0% +completeness one so we're good we talked + + + align:start position:0% +completeness one so we're good we talked +about Su checks any question about + + align:start position:0% +about Su checks any question about + + + align:start position:0% +about Su checks any question about +soundness any question about the + + align:start position:0% + + + + align:start position:0% + +soundness okay uh let's talk about the + + align:start position:0% +soundness okay uh let's talk about the + + + align:start position:0% +soundness okay uh let's talk about the +complexity the so uh the randomness + + align:start position:0% +complexity the so uh the randomness + + + align:start position:0% +complexity the so uh the randomness +complexity in the communic in the query + + align:start position:0% +complexity in the communic in the query + + + align:start position:0% +complexity in the communic in the query +complexity so how much query and + + align:start position:0% +complexity so how much query and + + + align:start position:0% +complexity so how much query and +Randomness do we need so the randomness + + align:start position:0% +Randomness do we need so the randomness + + + align:start position:0% +Randomness do we need so the randomness +complexity is well there's 2D a so let's + + align:start position:0% +complexity is well there's 2D a so let's + + + align:start position:0% +complexity is well there's 2D a so let's +put here + + align:start position:0% + + + + align:start position:0% + +Randomness so there's 2D sum check so + + align:start position:0% +Randomness so there's 2D sum check so + + + align:start position:0% +Randomness so there's 2D sum check so +the verifier kind of he interacts with + + align:start position:0% +the verifier kind of he interacts with + + + align:start position:0% +the verifier kind of he interacts with +his Oracle on 2D sum checks so for each + + align:start position:0% +his Oracle on 2D sum checks so for each + + + align:start position:0% +his Oracle on 2D sum checks so for each +2D sum checks he needs to toss coins now + + align:start position:0% +2D sum checks he needs to toss coins now + + + align:start position:0% +2D sum checks he needs to toss coins now +how much coins does he toss well he + + align:start position:0% +how much coins does he toss well he + + + align:start position:0% +how much coins does he toss well he +needs to generate our random in F to the + + align:start position:0% +needs to generate our random in F to the + + + align:start position:0% +needs to generate our random in F to the +3M that's a su each Su check you need so + + align:start position:0% +3M that's a su each Su check you need so + + + align:start position:0% +3M that's a su each Su check you need so +it's F to the it's like 3M log F bits of + + align:start position:0% +it's F to the it's like 3M log F bits of + + + align:start position:0% +it's F to the it's like 3M log F bits of +Randomness now this is really poly log F + + align:start position:0% +Randomness now this is really poly log F + + + align:start position:0% +Randomness now this is really poly log F +it's it's it's uh it's like poly s it's + + align:start position:0% +it's it's it's uh it's like poly s it's + + + align:start position:0% +it's it's it's uh it's like poly s it's +not log s okay this is really poly not + + align:start position:0% +not log s okay this is really poly not + + + align:start position:0% +not log s okay this is really poly not +not poly log s not just logs so one can + + align:start position:0% +not poly log s not just logs so one can + + + align:start position:0% +not poly log s not just logs so one can +be wait we need to be careful because uh + + align:start position:0% +be wait we need to be careful because uh + + + align:start position:0% +be wait we need to be careful because uh +are we sure we're getting an efficient + + align:start position:0% +are we sure we're getting an efficient + + + align:start position:0% +are we sure we're getting an efficient +PCP here it's a lot of Randomness are we + + align:start position:0% +PCP here it's a lot of Randomness are we + + + align:start position:0% +PCP here it's a lot of Randomness are we +sure there's no blow up in PCP and the + + align:start position:0% +sure there's no blow up in PCP and the + + + align:start position:0% +sure there's no blow up in PCP and the +reason there's no blow up the reason we + + align:start position:0% +reason there's no blow up the reason we + + + align:start position:0% +reason there's no blow up the reason we +have large Randomness yet the the PCP is + + align:start position:0% +have large Randomness yet the the PCP is + + + align:start position:0% +have large Randomness yet the the PCP is +small is exactly because GK has this + + align:start position:0% +small is exactly because GK has this + + + align:start position:0% +small is exactly because GK has this +property of forgetting this uh the fact + + align:start position:0% +property of forgetting this uh the fact + + + align:start position:0% +property of forgetting this uh the fact +we actually don't need to open the + + align:start position:0% +we actually don't need to open the + + + align:start position:0% +we actually don't need to open the +entire tree because of that we use kind + + align:start position:0% +entire tree because of that we use kind + + + align:start position:0% +entire tree because of that we use kind +of an additional property if the point + + align:start position:0% +of an additional property if the point + + + align:start position:0% +of an additional property if the point +is if you know nothing about the + + align:start position:0% +is if you know nothing about the + + + align:start position:0% +is if you know nothing about the +PCP then of course as I said if it's + + align:start position:0% +PCP then of course as I said if it's + + + align:start position:0% +PCP then of course as I said if it's +order log as bits of Randomness it's + + align:start position:0% +order log as bits of Randomness it's + + + align:start position:0% +order log as bits of Randomness it's +always the size PS but the fact that + + align:start position:0% +always the size PS but the fact that + + + align:start position:0% +always the size PS but the fact that +there more bits of Randomness does not + + align:start position:0% +there more bits of Randomness does not + + + align:start position:0% +there more bits of Randomness does not +necessarily Force our PCP to be bigger + + align:start position:0% +necessarily Force our PCP to be bigger + + + align:start position:0% +necessarily Force our PCP to be bigger +we're just not going to open it like + + align:start position:0% +we're just not going to open it like + + + align:start position:0% +we're just not going to open it like +trivially like oh if if we did open it + + align:start position:0% +trivially like oh if if we did open it + + + align:start position:0% +trivially like oh if if we did open it +trivially then we would look at all the + + align:start position:0% +trivially then we would look at all the + + + align:start position:0% +trivially then we would look at all the +around it would be a huge tree like the + + align:start position:0% +around it would be a huge tree like the + + + align:start position:0% +around it would be a huge tree like the +depth but because we do it kind of we + + align:start position:0% +depth but because we do it kind of we + + + align:start position:0% +depth but because we do it kind of we +pack it efficiently we're able to get a + + align:start position:0% +pack it efficiently we're able to get a + + + align:start position:0% +pack it efficiently we're able to get a +small PCP even though we have a lot of + + align:start position:0% +small PCP even though we have a lot of + + + align:start position:0% +small PCP even though we have a lot of +Randomness is it because you're saying + + align:start position:0% +Randomness is it because you're saying + + + align:start position:0% +Randomness is it because you're saying +each tree is size poly and po exactly + + align:start position:0% +each tree is size poly and po exactly + + + align:start position:0% +each tree is size poly and po exactly +each tree is size poly and they're poly + + align:start position:0% +each tree is size poly and they're poly + + + align:start position:0% +each tree is size poly and they're poly +trees and we're not like there's a more + + align:start position:0% +trees and we're not like there's a more + + + align:start position:0% +trees and we're not like there's a more +kind of straightforward way to do it is + + align:start position:0% +kind of straightforward way to do it is + + + align:start position:0% +kind of straightforward way to do it is +for each tree a pen a p like in no we're + + align:start position:0% +for each tree a pen a p like in no we're + + + align:start position:0% +for each tree a pen a p like in no we're +we're kind of doing them in chunks uh + + align:start position:0% +we're kind of doing them in chunks uh + + + align:start position:0% +we're kind of doing them in chunks uh +and so we get the the + + align:start position:0% +and so we get the the + + + align:start position:0% +and so we get the the +efficiency okay uh let's go let's go for + + align:start position:0% +efficiency okay uh let's go let's go for + + + align:start position:0% +efficiency okay uh let's go let's go for +the uh query + + align:start position:0% + + + + align:start position:0% + +complexity okay I'll just put it + + align:start position:0% + + + + align:start position:0% + +here so let's see so for again what's + + align:start position:0% +here so let's see so for again what's + + + align:start position:0% +here so let's see so for again what's +the query he does gkr so he does + + align:start position:0% +the query he does gkr so he does + + + align:start position:0% +the query he does gkr so he does +2D sum checks for each sum check he + + align:start position:0% +2D sum checks for each sum check he + + + align:start position:0% +2D sum checks for each sum check he +needs to read kind of what's what what + + align:start position:0% +needs to read kind of what's what what + + + align:start position:0% +needs to read kind of what's what what +the answer is each answer so there's + + align:start position:0% +the answer is each answer so there's + + + align:start position:0% +the answer is each answer so there's +three M rounds that he needs to read in + + align:start position:0% +three M rounds that he needs to read in + + + align:start position:0% +three M rounds that he needs to read in +each answer he gets kind of a univariate + + align:start position:0% +each answer he gets kind of a univariate + + + align:start position:0% +each answer he gets kind of a univariate +polinomial of small degree so he that + + align:start position:0% +polinomial of small degree so he that + + + align:start position:0% +polinomial of small degree so he that +each answer is not just one field + + align:start position:0% +each answer is not just one field + + + align:start position:0% +each answer is not just one field +element it's actually a few field + + align:start position:0% +element it's actually a few field + + + align:start position:0% +element it's actually a few field +elements + + align:start position:0% +elements + + + align:start position:0% +elements +um a + + align:start position:0% + + + + align:start position:0% + +so it's so he gets log F + + align:start position:0% +so it's so he gets log F + + + align:start position:0% +so it's so he gets log F +elements times a + + align:start position:0% + + + + align:start position:0% + +um the degree which will be in each Su + + align:start position:0% +um the degree which will be in each Su + + + align:start position:0% +um the degree which will be in each Su +check like poly + + align:start position:0% +check like poly + + + align:start position:0% +check like poly +H and most and this again goes back to + + align:start position:0% +H and most and this again goes back to + + + align:start position:0% +H and most and this again goes back to +the gold what's exactly the degree of + + align:start position:0% +the gold what's exactly the degree of + + + align:start position:0% +the gold what's exactly the degree of +the a multi it's polinomial so I'm not + + align:start position:0% +the a multi it's polinomial so I'm not + + + align:start position:0% +the a multi it's polinomial so I'm not +it's polinomial in h it's poly log H I + + align:start position:0% +it's polinomial in h it's poly log H I + + + align:start position:0% +it's polinomial in h it's poly log H I +don't want this is kind of the + + align:start position:0% +don't want this is kind of the + + + align:start position:0% +don't want this is kind of the +degree of uh each of the Su check + + align:start position:0% +degree of uh each of the Su check + + + align:start position:0% +degree of uh each of the Su check +polinomial + + align:start position:0% + + + + align:start position:0% + +and the degrees affected by the ADI and + + align:start position:0% +and the degrees affected by the ADI and + + + align:start position:0% +and the degrees affected by the ADI and +multi which we assumed are the degree is + + align:start position:0% +multi which we assumed are the degree is + + + align:start position:0% +multi which we assumed are the degree is +like + + align:start position:0% +like + + + align:start position:0% +like +poly uh but it's still again polylog so + + align:start position:0% +poly uh but it's still again polylog so + + + align:start position:0% +poly uh but it's still again polylog so +this gives so okay so before we take a + + align:start position:0% +this gives so okay so before we take a + + + align:start position:0% +this gives so okay so before we take a +break H let + + align:start position:0% +break H let + + + align:start position:0% +break H let +me where where where are we now uh so + + align:start position:0% +me where where where are we now uh so + + + align:start position:0% +me where where where are we now uh so +you know we studied the we started + + align:start position:0% +you know we studied the we started + + + align:start position:0% +you know we studied the we started +actually this this class by looking at + + align:start position:0% +actually this this class by looking at + + + align:start position:0% +actually this this class by looking at +some check so I started this class by + + align:start position:0% +some check so I started this class by + + + align:start position:0% +some check so I started this class by +telling you look some Che is a miracle + + align:start position:0% +telling you look some Che is a miracle + + + align:start position:0% +telling you look some Che is a miracle +like giving some Che it gives you + + align:start position:0% +like giving some Che it gives you + + + align:start position:0% +like giving some Che it gives you +everything everything and I hope that + + align:start position:0% +everything everything and I hope that + + + align:start position:0% +everything everything and I hope that +now you see why so we surve some Che and + + align:start position:0% +now you see why so we surve some Che and + + + align:start position:0% +now you see why so we surve some Che and +we looked at some like who cares okay + + align:start position:0% +we looked at some like who cares okay + + + align:start position:0% +we looked at some like who cares okay +this it seemed like why would we need to + + align:start position:0% +this it seemed like why would we need to + + + align:start position:0% +this it seemed like why would we need to +some over so many very multivariate + + align:start position:0% +some over so many very multivariate + + + align:start position:0% +some over so many very multivariate +polinomial where does that come up I + + align:start position:0% +polinomial where does that come up I + + + align:start position:0% +polinomial where does that come up I +don't know it was like okay why am I + + align:start position:0% +don't know it was like okay why am I + + + align:start position:0% +don't know it was like okay why am I +learning this but you know so now where + + align:start position:0% +learning this but you know so now where + + + align:start position:0% +learning this but you know so now where +what did we do with it we start with + + align:start position:0% +what did we do with it we start with + + + align:start position:0% +what did we do with it we start with +with Su we saw + + align:start position:0% +with Su we saw + + + align:start position:0% +with Su we saw +oh just by doing something + + align:start position:0% +oh just by doing something + + + align:start position:0% +oh just by doing something +repeatedly you can verify any low depth + + align:start position:0% +repeatedly you can verify any low depth + + + align:start position:0% +repeatedly you can verify any low depth +computation that's pretty amazing and + + align:start position:0% +computation that's pretty amazing and + + + align:start position:0% +computation that's pretty amazing and +then we saw that actually you can + + align:start position:0% +then we saw that actually you can + + + align:start position:0% +then we saw that actually you can +recover the IP equals P space theorem + + align:start position:0% +recover the IP equals P space theorem + + + align:start position:0% +recover the IP equals P space theorem +that GK actually gives his IP equals P + + align:start position:0% +that GK actually gives his IP equals P + + + align:start position:0% +that GK actually gives his IP equals P +space theorem and now we see gkr + + align:start position:0% +space theorem and now we see gkr + + + align:start position:0% +space theorem and now we see gkr +actually gives you + + align:start position:0% +actually gives you + + + align:start position:0% +actually gives you +PCP and what is GK is just Su + + align:start position:0% +PCP and what is GK is just Su + + + align:start position:0% +PCP and what is GK is just Su +checks okay so just these Su checks you + + align:start position:0% +checks okay so just these Su checks you + + + align:start position:0% +checks okay so just these Su checks you +kind of unroll them unravel them and you + + align:start position:0% +kind of unroll them unravel them and you + + + align:start position:0% +kind of unroll them unravel them and you +get a PCP with polog and + + align:start position:0% +get a PCP with polog and + + + align:start position:0% +get a PCP with polog and +queries and not and it's like efficient + + align:start position:0% +queries and not and it's like efficient + + + align:start position:0% +queries and not and it's like efficient +you can take your input effic your + + align:start position:0% +you can take your input effic your + + + align:start position:0% +you can take your input effic your +witness and efficiently generate this + + align:start position:0% +witness and efficiently generate this + + + align:start position:0% +witness and efficiently generate this +PCP and in a very + + align:start position:0% +PCP and in a very + + + align:start position:0% +PCP and in a very +a like a straightforward way in a sense + + align:start position:0% +a like a straightforward way in a sense + + + align:start position:0% +a like a straightforward way in a sense +you do your computation you have your + + align:start position:0% +you do your computation you have your + + + align:start position:0% +you do your computation you have your +witness you do the computation you do + + align:start position:0% +witness you do the computation you do + + + align:start position:0% +witness you do the computation you do +all the lree extensions and you convince + + align:start position:0% +all the lree extensions and you convince + + + align:start position:0% +all the lree extensions and you convince +round by round you just lay it out + + align:start position:0% +round by round you just lay it out + + + align:start position:0% +round by round you just lay it out +that's it and you have a + + align:start position:0% + + + + align:start position:0% + +PCP okay any any questions about + + align:start position:0% + + + + align:start position:0% + +yeah that relies on just the fact that + + align:start position:0% +yeah that relies on just the fact that + + + align:start position:0% +yeah that relies on just the fact that +it consists of these kind of like + + align:start position:0% +it consists of these kind of like + + + align:start position:0% +it consists of these kind of like +independent subs or also the fact that + + align:start position:0% +independent subs or also the fact that + + + align:start position:0% +independent subs or also the fact that +some itself that each is just random + + align:start position:0% +some itself that each is just random + + + align:start position:0% +some itself that each is just random +good good good so the question is again + + align:start position:0% +good good good so the question is again + + + align:start position:0% +good good good so the question is again +let's understand why do we get this PCP + + align:start position:0% +let's understand why do we get this PCP + + + align:start position:0% +let's understand why do we get this PCP +that's efficient okay why do we get only + + align:start position:0% +that's efficient okay why do we get only + + + align:start position:0% +that's efficient okay why do we get only +poly siiz PCP and the reason we get is + + align:start position:0% +poly siiz PCP and the reason we get is + + + align:start position:0% +poly siiz PCP and the reason we get is +to both twofolds you you said both + + align:start position:0% +to both twofolds you you said both + + + align:start position:0% +to both twofolds you you said both +reasons reason number one that when we + + align:start position:0% +reasons reason number one that when we + + + align:start position:0% +reasons reason number one that when we +do each sum check after that we can + + align:start position:0% +do each sum check after that we can + + + align:start position:0% +do each sum check after that we can +forget about this Randomness and for + + align:start position:0% +forget about this Randomness and for + + + align:start position:0% +forget about this Randomness and for +each VI consider so we really need to + + align:start position:0% +each VI consider so we really need to + + + align:start position:0% +each VI consider so we really need to +write down only kind of D times F to the + + align:start position:0% +write down only kind of D times F to the + + + align:start position:0% +write down only kind of D times F to the +m sub checks okay that's D the depth of + + align:start position:0% +m sub checks okay that's D the depth of + + + align:start position:0% +m sub checks okay that's D the depth of +the circuit time F to the M Subs that's + + align:start position:0% +the circuit time F to the M Subs that's + + + align:start position:0% +the circuit time F to the M Subs that's +number one but number two why is the sum + + align:start position:0% +number one but number two why is the sum + + + align:start position:0% +number one but number two why is the sum +check can we write out all the sum check + + align:start position:0% +check can we write out all the sum check + + + align:start position:0% +check can we write out all the sum check +I mean the sum check is also an + + align:start position:0% +I mean the sum check is also an + + + align:start position:0% +I mean the sum check is also an +interactive protocol can we actually + + align:start position:0% +interactive protocol can we actually + + + align:start position:0% +interactive protocol can we actually +open it up and write the entire thing + + align:start position:0% +open it up and write the entire thing + + + align:start position:0% +open it up and write the entire thing +and the answer is well yeah but at a + + align:start position:0% +and the answer is well yeah but at a + + + align:start position:0% +and the answer is well yeah but at a +exponential cost and but an exponential + + align:start position:0% +exponential cost and but an exponential + + + align:start position:0% +exponential cost and but an exponential +cost in M the number of variables but + + align:start position:0% +cost in M the number of variables but + + + align:start position:0% +cost in M the number of variables but +here the number of variables is + + align:start position:0% +here the number of variables is + + + align:start position:0% +here the number of variables is +log that's important we if M was polog + + align:start position:0% +log that's important we if M was polog + + + align:start position:0% +log that's important we if M was polog +we would have been + + align:start position:0% +we would have been + + + align:start position:0% +we would have been +doomed but M or I mean okay uh it's not + + align:start position:0% +doomed but M or I mean okay uh it's not + + + align:start position:0% +doomed but M or I mean okay uh it's not +just log it's it's we set the parameter + + align:start position:0% +just log it's it's we set the parameter + + + align:start position:0% +just log it's it's we set the parameter +so that it's okay that's what we needed + + align:start position:0% +so that it's okay that's what we needed + + + align:start position:0% +so that it's okay that's what we needed +that's exactly so why can we open up + + align:start position:0% +that's exactly so why can we open up + + + align:start position:0% +that's exactly so why can we open up +this entire sum check it's because we + + align:start position:0% +this entire sum check it's because we + + + align:start position:0% +this entire sum check it's because we +set F to be poly H and H to the m is s + + align:start position:0% +set F to be poly H and H to the m is s + + + align:start position:0% +set F to be poly H and H to the m is s +so we we set it up so that you know + + align:start position:0% +so we we set it up so that you know + + + align:start position:0% +so we we set it up so that you know +opening the sum check + + align:start position:0% +opening the sum check + + + align:start position:0% +opening the sum check +requires F to the m kind of answers uh F + + align:start position:0% +requires F to the m kind of answers uh F + + + align:start position:0% +requires F to the m kind of answers uh F +to the m answers each one is kind of a + + align:start position:0% +to the m answers each one is kind of a + + + align:start position:0% +to the m answers each one is kind of a +low degree polinomial but that's that's + + align:start position:0% +low degree polinomial but that's that's + + + align:start position:0% +low degree polinomial but that's that's +fine but F to the m of them or F to the + + align:start position:0% +fine but F to the m of them or F to the + + + align:start position:0% +fine but F to the m of them or F to the +3M here because we have the number of + + align:start position:0% +3M here because we have the number of + + + align:start position:0% +3M here because we have the number of +variables is 3M + + align:start position:0% +variables is 3M + + + align:start position:0% +variables is 3M +uh and we just need to make sure that + + align:start position:0% +uh and we just need to make sure that + + + align:start position:0% +uh and we just need to make sure that +after the 3M is polinomial and to ensure + + align:start position:0% +after the 3M is polinomial and to ensure + + + align:start position:0% +after the 3M is polinomial and to ensure +that we did do some parameter + + align:start position:0% +that we did do some parameter + + + align:start position:0% +that we did do some parameter +engineering that's why we didn't go the + + align:start position:0% +engineering that's why we didn't go the + + + align:start position:0% +engineering that's why we didn't go the +natural route of taking H to be two and + + align:start position:0% +natural route of taking H to be two and + + + align:start position:0% +natural route of taking H to be two and +M to be log s that would be natural but + + align:start position:0% +M to be log s that would be natural but + + + align:start position:0% +M to be log s that would be natural but +then we would not get so we actually did + + align:start position:0% +then we would not get so we actually did + + + align:start position:0% +then we would not get so we actually did +need to do some kind of Engineering in + + align:start position:0% +need to do some kind of Engineering in + + + align:start position:0% +need to do some kind of Engineering in +parameters uh like an annoying fiddling + + align:start position:0% +parameters uh like an annoying fiddling + + + align:start position:0% +parameters uh like an annoying fiddling +of parameters uh you know this uh this + + align:start position:0% +of parameters uh you know this uh this + + + align:start position:0% +of parameters uh you know this uh this +setting of parameters that you see over + + align:start position:0% +setting of parameters that you see over + + + align:start position:0% +setting of parameters that you see over +and over in any PCP construction this is + + align:start position:0% +and over in any PCP construction this is + + + align:start position:0% +and over in any PCP construction this is +you know we're not the first so we're + + align:start position:0% +you know we're not the first so we're + + + align:start position:0% +you know we're not the first so we're +actually the last if anything to come to + + align:start position:0% +actually the last if anything to come to + + + align:start position:0% +actually the last if anything to come to +use this this was used in the '90s in + + align:start position:0% +use this this was used in the '90s in + + + align:start position:0% +use this this was used in the '90s in +the early PCP constructions and um and + + align:start position:0% +the early PCP constructions and um and + + + align:start position:0% +the early PCP constructions and um and +it's when you look at it first like oh + + align:start position:0% +it's when you look at it first like oh + + + align:start position:0% +it's when you look at it first like oh +really like log n over log log n are you + + align:start position:0% +really like log n over log log n are you + + + align:start position:0% +really like log n over log log n are you +kidding me like couldn't you find + + align:start position:0% +kidding me like couldn't you find + + + align:start position:0% +kidding me like couldn't you find +something nicer but this is this is why + + align:start position:0% +something nicer but this is this is why + + + align:start position:0% +something nicer but this is this is why +because we want these parameters to be + + align:start position:0% +because we want these parameters to be + + + align:start position:0% +because we want these parameters to be +poly yeah so since you're essentially + + align:start position:0% +poly yeah so since you're essentially + + + align:start position:0% +poly yeah so since you're essentially +asking for this for this to be like a + + align:start position:0% +asking for this for this to be like a + + + align:start position:0% +asking for this for this to be like a +nonadaptive can you just like use the + + align:start position:0% +nonadaptive can you just like use the + + + align:start position:0% +nonadaptive can you just like use the +same for and get + + align:start position:0% +same for and get + + + align:start position:0% +same for and get +the so sorry so you're saying sorry your + + align:start position:0% +the so sorry so you're saying sorry your + + + align:start position:0% +the so sorry so you're saying sorry your +question is you're saying you are you + + align:start position:0% +question is you're saying you are you + + + align:start position:0% +question is you're saying you are you +talking about the non the fact that this + + align:start position:0% +talking about the non the fact that this + + + align:start position:0% +talking about the non the fact that this +verifier is nonadaptive or or that + + align:start position:0% +verifier is nonadaptive or or that + + + align:start position:0% +verifier is nonadaptive or or that +theover is nonadaptive right the prover + + align:start position:0% +theover is nonadaptive right the prover + + + align:start position:0% +theover is nonadaptive right the prover +in the yes M like it's not adaptive in + + align:start position:0% +in the yes M like it's not adaptive in + + + align:start position:0% +in the yes M like it's not adaptive in +the previous in the previous uh Su + + align:start position:0% +the previous in the previous uh Su + + + align:start position:0% +the previous in the previous uh Su +checks previous Su checks yeah so then + + align:start position:0% +checks previous Su checks yeah so then + + + align:start position:0% +checks previous Su checks yeah so then +what can you use the same Randomness for + + align:start position:0% +what can you use the same Randomness for + + + align:start position:0% +what can you use the same Randomness for +each round like what would happen if you + + align:start position:0% +each round like what would happen if you + + + align:start position:0% +each round like what would happen if you +theand no okay okay okay that's a good + + align:start position:0% +theand no okay okay okay that's a good + + + align:start position:0% +theand no okay okay okay that's a good +question so you're asking you're saying + + align:start position:0% +question so you're asking you're saying + + + align:start position:0% +question so you're asking you're saying +look we're doing the sum check D times + + align:start position:0% +look we're doing the sum check D times + + + align:start position:0% +look we're doing the sum check D times +can't we use the same Randomness and the + + align:start position:0% +can't we use the same Randomness and the + + + align:start position:0% +can't we use the same Randomness and the +answer is we cannot why because you + + align:start position:0% +answer is we cannot why because you + + + align:start position:0% +answer is we cannot why because you +should think if you use the same + + align:start position:0% +should think if you use the same + + + align:start position:0% +should think if you use the same +Randomness for different rounds then you + + align:start position:0% +Randomness for different rounds then you + + + align:start position:0% +Randomness for different rounds then you +should think of I'm aover I'm like oh I + + align:start position:0% +should think of I'm aover I'm like oh I + + + align:start position:0% +should think of I'm aover I'm like oh I +I'm you're going to use the same + + align:start position:0% +I'm you're going to use the same + + + align:start position:0% +I'm you're going to use the same +Randomness for all your rounds I know + + align:start position:0% +Randomness for all your rounds I know + + + align:start position:0% +Randomness for all your rounds I know +that because you're telling me already + + align:start position:0% +that because you're telling me already + + + align:start position:0% +that because you're telling me already +that you're going to use the same + + align:start position:0% +that you're going to use the same + + + align:start position:0% +that you're going to use the same +Randomness so now in the first round I'm + + align:start position:0% +Randomness so now in the first round I'm + + + align:start position:0% +Randomness so now in the first round I'm +I'm going to behave honestly just learn + + align:start position:0% +I'm going to behave honestly just learn + + + align:start position:0% +I'm going to behave honestly just learn +your Randomness give you so I'm sorry + + align:start position:0% +your Randomness give you so I'm sorry + + + align:start position:0% +your Randomness give you so I'm sorry +I'm not going to be I'm going to cheat + + align:start position:0% +I'm not going to be I'm going to cheat + + + align:start position:0% +I'm not going to be I'm going to cheat +in the first round okay so of course I'm + + align:start position:0% +in the first round okay so of course I'm + + + align:start position:0% +in the first round okay so of course I'm +going to I'm the output is one even + + align:start position:0% +going to I'm the output is one even + + + align:start position:0% +going to I'm the output is one even +though it's zero I'm going to manage to + + align:start position:0% +though it's zero I'm going to manage to + + + align:start position:0% +though it's zero I'm going to manage to +convince you in the first kind of in the + + align:start position:0% +convince you in the first kind of in the + + + align:start position:0% +convince you in the first kind of in the +first Su check I do yeah because I'm + + align:start position:0% +first Su check I do yeah because I'm + + + align:start position:0% +first Su check I do yeah because I'm +just going to lie consistently with + + align:start position:0% +just going to lie consistently with + + + align:start position:0% +just going to lie consistently with +myself arrive to VI to the next layer + + align:start position:0% +myself arrive to VI to the next layer + + + align:start position:0% +myself arrive to VI to the next layer +and the wrong still inconsistent but now + + align:start position:0% +and the wrong still inconsistent but now + + + align:start position:0% +and the wrong still inconsistent but now +I know the randomness that cuz you're + + align:start position:0% +I know the randomness that cuz you're + + + align:start position:0% +I know the randomness that cuz you're +going to reuse you see here the point is + + align:start position:0% +going to reuse you see here the point is + + + align:start position:0% +going to reuse you see here the point is +that the following the verifier here + + align:start position:0% +that the following the verifier here + + + align:start position:0% +that the following the verifier here +should behave like a like an honest + + align:start position:0% +should behave like a like an honest + + + align:start position:0% +should behave like a like an honest +verifier in the gkr if the verifier here + + align:start position:0% +verifier in the gkr if the verifier here + + + align:start position:0% +verifier in the gkr if the verifier here +you cannot if when you use this verifier + + align:start position:0% +you cannot if when you use this verifier + + + align:start position:0% +you cannot if when you use this verifier +he + + align:start position:0% +he + + + align:start position:0% +he +essentially behaves like a GK verifier + + align:start position:0% +essentially behaves like a GK verifier + + + align:start position:0% +essentially behaves like a GK verifier +so now you're telling you're saying look + + align:start position:0% +so now you're telling you're saying look + + + align:start position:0% +so now you're telling you're saying look +why doesn't he use the same Randomness + + align:start position:0% +why doesn't he use the same Randomness + + + align:start position:0% +why doesn't he use the same Randomness +for the different uh subprotocols + + align:start position:0% +for the different uh subprotocols + + + align:start position:0% +for the different uh subprotocols +because if he didn't gkr then he would + + align:start position:0% +because if he didn't gkr then he would + + + align:start position:0% +because if he didn't gkr then he would +fail then you the a cheating prover can + + align:start position:0% +fail then you the a cheating prover can + + + align:start position:0% +fail then you the a cheating prover can +can take advantage of him is isn't there + + align:start position:0% +can take advantage of him is isn't there + + + align:start position:0% +can take advantage of him is isn't there +the difference here that this is + + align:start position:0% +the difference here that this is + + + align:start position:0% +the difference here that this is +nonadaptive like it doesn't remember the + + align:start position:0% +nonadaptive like it doesn't remember the + + + align:start position:0% +nonadaptive like it doesn't remember the +randomness all it depends on + + align:start position:0% + + + + align:start position:0% + +is right so you can't just be like oh + + align:start position:0% +is right so you can't just be like oh + + + align:start position:0% +is right so you can't just be like oh +this is the random oh I see you're + + align:start position:0% +this is the random oh I see you're + + + align:start position:0% +this is the random oh I see you're +saying I see I see okay okay now I + + align:start position:0% +saying I see I see okay okay now I + + + align:start position:0% +saying I see I see okay okay now I +understand your question you're saying + + align:start position:0% +understand your question you're saying + + + align:start position:0% +understand your question you're saying +this guy this uh prover is stuck okay + + align:start position:0% +this guy this uh prover is stuck okay + + + align:start position:0% +this guy this uh prover is stuck okay +okay sorry now I'm I understand what + + align:start position:0% +okay sorry now I'm I understand what + + + align:start position:0% +okay sorry now I'm I understand what +you're saying you're saying look you're + + align:start position:0% +you're saying you're saying look you're + + + align:start position:0% +you're saying you're saying look you're +tying the hand of the prover the prover + + align:start position:0% +tying the hand of the prover the prover + + + align:start position:0% +tying the hand of the prover the prover +in + + align:start position:0% +in + + + align:start position:0% +in +gkr he has power he sees your Randomness + + align:start position:0% +gkr he has power he sees your Randomness + + + align:start position:0% +gkr he has power he sees your Randomness +and based on that he can continue the + + align:start position:0% +and based on that he can continue the + + + align:start position:0% +and based on that he can continue the +honest Pro of course won't do that but + + align:start position:0% +honest Pro of course won't do that but + + + align:start position:0% +honest Pro of course won't do that but +the cheating prover May here you're + + align:start position:0% +the cheating prover May here you're + + + align:start position:0% +the cheating prover May here you're +saying I'm not going to let the prover + + align:start position:0% +saying I'm not going to let the prover + + + align:start position:0% +saying I'm not going to let the prover +do that to me I'm G to force him to + + align:start position:0% +do that to me I'm G to force him to + + + align:start position:0% +do that to me I'm G to force him to +forget because I force him to forget can + + align:start position:0% +forget because I force him to forget can + + + align:start position:0% +forget because I force him to forget can +I think of using the same Randomness + + align:start position:0% +I think of using the same Randomness + + + align:start position:0% +I think of using the same Randomness +that's a good question + + align:start position:0% +that's a good question + + + align:start position:0% +that's a good question +actually a great very good question I it + + align:start position:0% +actually a great very good question I it + + + align:start position:0% +actually a great very good question I it +took me time to understand what you're + + align:start position:0% +took me time to understand what you're + + + align:start position:0% +took me time to understand what you're +asking a + + align:start position:0% + + + + align:start position:0% + +can you use the same it's great qu great + + align:start position:0% +can you use the same it's great qu great + + + align:start position:0% +can you use the same it's great qu great +point verif just said to break that well + + align:start position:0% +point verif just said to break that well + + + align:start position:0% +point verif just said to break that well +no because what okay so I'm so okay so + + align:start position:0% +no because what okay so I'm so okay so + + + align:start position:0% +no because what okay so I'm so okay so +we are pointed the F said you know what + + align:start position:0% +we are pointed the F said you know what + + + align:start position:0% +we are pointed the F said you know what +use the same Randomness in all the + + align:start position:0% +use the same Randomness in all the + + + align:start position:0% +use the same Randomness in all the +subprotocols now in the gkr it's a big + + align:start position:0% +subprotocols now in the gkr it's a big + + + align:start position:0% +subprotocols now in the gkr it's a big +problem because the prover he knows what + + align:start position:0% +problem because the prover he knows what + + + align:start position:0% +problem because the prover he knows what +you saw and he'll use that like he know + + align:start position:0% +you saw and he'll use that like he know + + + align:start position:0% +you saw and he'll use that like he know +the but in in the PCP the + + align:start position:0% +the but in in the PCP the + + + align:start position:0% +the but in in the PCP the +PCP gkr prover his hands are tied yeah + + align:start position:0% +PCP gkr prover his hands are tied yeah + + + align:start position:0% +PCP gkr prover his hands are tied yeah +but the fact like if the Prov knows that + + align:start position:0% +but the fact like if the Prov knows that + + + align:start position:0% +but the fact like if the Prov knows that +you're going to do this then he might be + + align:start position:0% +you're going to do this then he might be + + + align:start position:0% +you're going to do this then he might be +able to engineer all of his responses in + + align:start position:0% +able to engineer all of his responses in + + + align:start position:0% +able to engineer all of his responses in +a way that like takes advantage of the + + align:start position:0% +a way that like takes advantage of the + + + align:start position:0% +a way that like takes advantage of the +correlation of right like by exactly + + align:start position:0% +correlation of right like by exactly + + + align:start position:0% +correlation of right like by exactly +using the same verifier you said like + + align:start position:0% +using the same verifier you said like + + + align:start position:0% +using the same verifier you said like +you pretend you have that verifier that + + align:start position:0% +you pretend you have that verifier that + + + align:start position:0% +you pretend you have that verifier that +cheats you use the same Randomness now + + align:start position:0% +cheats you use the same Randomness now + + + align:start position:0% +cheats you use the same Randomness now +this tree follows that verifier + + align:start position:0% +this tree follows that verifier + + + align:start position:0% +this tree follows that verifier +strategy + + align:start position:0% + + + + align:start position:0% + +shouldn't yeah I mean it is it could be + + align:start position:0% +shouldn't yeah I mean it is it could be + + + align:start position:0% +shouldn't yeah I mean it is it could be +some but like there's this correlation + + align:start position:0% +some but like there's this correlation + + + align:start position:0% +some but like there's this correlation +between the randomness the would know + + align:start position:0% +between the randomness the would know + + + align:start position:0% +between the randomness the would know +about it in advance right so even though + + align:start position:0% +about it in advance right so even though + + + align:start position:0% +about it in advance right so even though +he can't remember the random he can + + align:start position:0% +he can't remember the random he can + + + align:start position:0% +he can't remember the random he can +engineer the strategy to take advantage + + align:start position:0% +engineer the strategy to take advantage + + + align:start position:0% +engineer the strategy to take advantage +of the fact the + + align:start position:0% +of the fact the + + + align:start position:0% +of the fact the +Rand okay let me say the following um to + + align:start position:0% +Rand okay let me say the following um to + + + align:start position:0% +Rand okay let me say the following um to +close this discussion a the discussion + + align:start position:0% +close this discussion a the discussion + + + align:start position:0% +close this discussion a the discussion +is super interesting the question you + + align:start position:0% +is super interesting the question you + + + align:start position:0% +is super interesting the question you +raised is super + + align:start position:0% +raised is super + + + align:start position:0% +raised is super +interesting you know we have one pet in + + align:start position:0% +interesting you know we have one pet in + + + align:start position:0% +interesting you know we have one pet in +this + + align:start position:0% +this + + + align:start position:0% +this +class you gave me a great uh idea for a + + align:start position:0% +class you gave me a great uh idea for a + + + align:start position:0% +class you gave me a great uh idea for a +question a a by the way um before we + + align:start position:0% +question a a by the way um before we + + + align:start position:0% +question a a by the way um before we +break I just want to make a quick + + align:start position:0% +break I just want to make a quick + + + align:start position:0% +break I just want to make a quick +announcement so I wrote in the in the + + align:start position:0% +announcement so I wrote in the in the + + + align:start position:0% +announcement so I wrote in the in the +website that the pet will come later in + + align:start position:0% +website that the pet will come later in + + + align:start position:0% +website that the pet will come later in +during this class because I thought it + + align:start position:0% +during this class because I thought it + + + align:start position:0% +during this class because I thought it +would be good to cover more + + align:start position:0% +would be good to cover more + + + align:start position:0% +would be good to cover more +material but uh I know that I wrote it + + align:start position:0% +material but uh I know that I wrote it + + + align:start position:0% +material but uh I know that I wrote it +pretty close like to the break and maybe + + align:start position:0% +pretty close like to the break and maybe + + + align:start position:0% +pretty close like to the break and maybe +that's so okay so maybe I'll I'll put it + + align:start position:0% +that's so okay so maybe I'll I'll put it + + + align:start position:0% +that's so okay so maybe I'll I'll put it +out earlier give you two weeks and just + + align:start position:0% +out earlier give you two weeks and just + + + align:start position:0% +out earlier give you two weeks and just +because I don't want to sit with it too + + align:start position:0% +because I don't want to sit with it too + + + align:start position:0% +because I don't want to sit with it too +long it's just annoying but if you feel + + align:start position:0% +long it's just annoying but if you feel + + + align:start position:0% +long it's just annoying but if you feel +like the time is doesn't work and you + + align:start position:0% +like the time is doesn't work and you + + + align:start position:0% +like the time is doesn't work and you +want an extension just let me know + + align:start position:0% +want an extension just let me know + + + align:start position:0% +want an extension just let me know +I don't really + + align:start position:0% +I don't really + + + align:start position:0% +I don't really +care I just want you to think about it + + align:start position:0% +care I just want you to think about it + + + align:start position:0% +care I just want you to think about it +and have fun with the you know with the + + align:start position:0% +and have fun with the you know with the + + + align:start position:0% +and have fun with the you know with the +material yeah the way we all do sound is + + align:start position:0% +material yeah the way we all do sound is + + + align:start position:0% +material yeah the way we all do sound is +are we using un bound like yeah exactly + + align:start position:0% +are we using un bound like yeah exactly + + + align:start position:0% +are we using un bound like yeah exactly +we're doing a union bound yeah yes + + align:start position:0% +we're doing a union bound yeah yes + + + align:start position:0% +we're doing a union bound yeah yes +exactly because the in the soundness we + + align:start position:0% +exactly because the in the soundness we + + + align:start position:0% +exactly because the in the soundness we +say the following we say that + + align:start position:0% +say the following we say that + + + align:start position:0% +say the following we say that +uh uh in the so essentially we're we're + + align:start position:0% +uh uh in the so essentially we're we're + + + align:start position:0% +uh uh in the so essentially we're we're +talking with a prover and GK prover and + + align:start position:0% +talking with a prover and GK prover and + + + align:start position:0% +talking with a prover and GK prover and +we're saying for the GK even like a tied + + align:start position:0% +we're saying for the GK even like a tied + + + align:start position:0% +we're saying for the GK even like a tied +GK Pro as you as you mentioned even it's + + align:start position:0% +GK Pro as you as you mentioned even it's + + + align:start position:0% +GK Pro as you as you mentioned even it's +a gar prover with tied hands so for this + + align:start position:0% +a gar prover with tied hands so for this + + + align:start position:0% +a gar prover with tied hands so for this +for this prover to cheat he need so the + + align:start position:0% +for this prover to cheat he need so the + + + align:start position:0% +for this prover to cheat he need so the +output is false that's kind of he + + align:start position:0% +output is false that's kind of he + + + align:start position:0% +output is false that's kind of he +cheated so somewhere he needs to cheat + + align:start position:0% +cheated so somewhere he needs to cheat + + + align:start position:0% +cheated so somewhere he needs to cheat +in one of the gkrs one of the one of the + + align:start position:0% +in one of the gkrs one of the one of the + + + align:start position:0% +in one of the gkrs one of the one of the +sum checks he needs to go from false to + + align:start position:0% +sum checks he needs to go from false to + + + align:start position:0% +sum checks he needs to go from false to +True somewhere because at the end you're + + align:start position:0% +True somewhere because at the end you're + + + align:start position:0% +True somewhere because at the end you're +verifying you verifying that you know he + + align:start position:0% +verifying you verifying that you know he + + + align:start position:0% +verifying you verifying that you know he +put here a witness so he put in the sky + + align:start position:0% +put here a witness so he put in the sky + + + align:start position:0% +put here a witness so he put in the sky +a witness that witness is false because + + align:start position:0% +a witness that witness is false because + + + align:start position:0% +a witness that witness is false because +there's no satisfying assignment so he + + align:start position:0% +there's no satisfying assignment so he + + + align:start position:0% +there's no satisfying assignment so he +put something that's actually + + align:start position:0% +put something that's actually + + + align:start position:0% +put something that's actually +false oh one second there is something + + align:start position:0% +false oh one second there is something + + + align:start position:0% +false oh one second there is something +okay sorry now I remember there is + + align:start position:0% +okay sorry now I remember there is + + + align:start position:0% +okay sorry now I remember there is +something there is a low deegree test to + + align:start position:0% +something there is a low deegree test to + + + align:start position:0% +something there is a low deegree test to +do we'll get back to that sorry uh we'll + + align:start position:0% +do we'll get back to that sorry uh we'll + + + align:start position:0% +do we'll get back to that sorry uh we'll +get back to the low degree test but uh + + align:start position:0% +get back to the low degree test but uh + + + align:start position:0% +get back to the low degree test but uh +there so you're talking with a um a + + align:start position:0% +there so you're talking with a um a + + + align:start position:0% +there so you're talking with a um a +you're talking with a GK prover and this + + align:start position:0% +you're talking with a GK prover and this + + + align:start position:0% +you're talking with a GK prover and this +prover the only way he can convince you + + align:start position:0% +prover the only way he can convince you + + + align:start position:0% +prover the only way he can convince you +is to go from like a false statement to + + align:start position:0% +is to go from like a false statement to + + + align:start position:0% +is to go from like a false statement to +a true statement because at the end you + + align:start position:0% +a true statement because at the end you + + + align:start position:0% +a true statement because at the end you +ver you and to do that you need to break + + align:start position:0% +ver you and to do that you need to break + + + align:start position:0% +ver you and to do that you need to break +one of the sum checks so to break one of + + align:start position:0% +one of the sum checks so to break one of + + + align:start position:0% +one of the sum checks so to break one of +the Su checks you have two Su checks and + + align:start position:0% +the Su checks you have two Su checks and + + + align:start position:0% +the Su checks you have two Su checks and +now I'm using a union bound to say that + + align:start position:0% +now I'm using a union bound to say that + + + align:start position:0% +now I'm using a union bound to say that +the probability that you kind of manag + + align:start position:0% +the probability that you kind of manag + + + align:start position:0% +the probability that you kind of manag +to break one of them is two to the D + + align:start position:0% +to break one of them is two to the D + + + align:start position:0% +to break one of them is two to the D +times the probability that you manage to + + align:start position:0% +times the probability that you manage to + + + align:start position:0% +times the probability that you manage to +break one of + + align:start position:0% +break one of + + + align:start position:0% +break one of +them okay but then back to discussion + + align:start position:0% +them okay but then back to discussion + + + align:start position:0% +them okay but then back to discussion +where like like sharing Randomness so + + align:start position:0% +where like like sharing Randomness so + + + align:start position:0% +where like like sharing Randomness so +does un help + + align:start position:0% +does un help + + + align:start position:0% +does un help +here you you're saying oh you're because + + align:start position:0% +here you you're saying oh you're because + + + align:start position:0% +here you you're saying oh you're because +of + + align:start position:0% +of + + + align:start position:0% +of +theend okay so this is is this related + + align:start position:0% +theend okay so this is is this related + + + align:start position:0% +theend okay so this is is this related +to this qu okay okay actually I don't + + align:start position:0% +to this qu okay okay actually I don't + + + align:start position:0% +to this qu okay okay actually I don't +think so because Union Bound in general + + align:start position:0% +think so because Union Bound in general + + + align:start position:0% +think so because Union Bound in general +it it can be correlated a union Bound in + + align:start position:0% +it it can be correlated a union Bound in + + + align:start position:0% +it it can be correlated a union Bound in +general says that the probability that + + align:start position:0% +general says that the probability that + + + align:start position:0% +general says that the probability that +this or this I don't care how they're + + align:start position:0% +this or this I don't care how they're + + + align:start position:0% +this or this I don't care how they're +correlated it's smaller or equal the + + align:start position:0% +correlated it's smaller or equal the + + + align:start position:0% +correlated it's smaller or equal the +probability of this plus the probability + + align:start position:0% +probability of this plus the probability + + + align:start position:0% +probability of this plus the probability +of this so the correlation here the + + align:start position:0% +of this so the correlation here the + + + align:start position:0% +of this so the correlation here the +union bound is + + align:start position:0% +union bound is + + + align:start position:0% +union bound is +very uh easily used in any situation you + + align:start position:0% +very uh easily used in any situation you + + + align:start position:0% +very uh easily used in any situation you +know just at the probability that you + + align:start position:0% +know just at the probability that you + + + align:start position:0% +know just at the probability that you +have an event you CH you cheated on test + + align:start position:0% +have an event you CH you cheated on test + + + align:start position:0% +have an event you CH you cheated on test +one you cheated on test two you cheated + + align:start position:0% +one you cheated on test two you cheated + + + align:start position:0% +one you cheated on test two you cheated +on test three I don't care how they're + + align:start position:0% +on test three I don't care how they're + + + align:start position:0% +on test three I don't care how they're +correlated the probability that you Che + + align:start position:0% +correlated the probability that you Che + + + align:start position:0% +correlated the probability that you Che +on one of them is small or equal + + align:start position:0% +on one of them is small or equal + + + align:start position:0% +on one of them is small or equal +then yeah but actually before we break + + align:start position:0% +then yeah but actually before we break + + + align:start position:0% +then yeah but actually before we break +sorry there is a some there is a low + + align:start position:0% +sorry there is a some there is a low + + + align:start position:0% +sorry there is a some there is a low +degree extension + + align:start position:0% +degree extension + + + align:start position:0% +degree extension +what + + align:start position:0% +what + + + align:start position:0% +what +exactly you can just + + align:start position:0% +exactly you can just + + + align:start position:0% +exactly you can just +use good okay okay okay + + align:start position:0% +use good okay okay okay + + + align:start position:0% +use good okay okay okay +sorry good uh I love you guys uh so uh + + align:start position:0% +sorry good uh I love you guys uh so uh + + + align:start position:0% +sorry good uh I love you guys uh so uh +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +V uh okay + + align:start position:0% + + + + align:start position:0% + +check v0 Tilda is low + + align:start position:0% + + + + align:start position:0% + +degree because in + + align:start position:0% +degree because in + + + align:start position:0% +degree because in +gkr the verifier has the W the the input + + align:start position:0% +gkr the verifier has the W the the input + + + align:start position:0% +gkr the verifier has the W the the input +which is the witness he computes the Lo + + align:start position:0% +which is the witness he computes the Lo + + + align:start position:0% +which is the witness he computes the Lo +extension by + + align:start position:0% +extension by + + + align:start position:0% +extension by +himself here the poer is giving it to + + align:start position:0% +himself here the poer is giving it to + + + align:start position:0% +himself here the poer is giving it to +him what if you didn't give a low degree + + align:start position:0% + + + + align:start position:0% + +so we do need one low degree test in the + + align:start position:0% +so we do need one low degree test in the + + + align:start position:0% +so we do need one low degree test in the +input other than that it's GK black box + + align:start position:0% +input other than that it's GK black box + + + align:start position:0% +input other than that it's GK black box +but we do need this and by the way note + + align:start position:0% +but we do need this and by the way note + + + align:start position:0% +but we do need this and by the way note +that we're using the gkr the gkr has + + align:start position:0% +that we're using the gkr the gkr has + + + align:start position:0% +that we're using the gkr the gkr has +actually um properties and now I want to + + align:start position:0% +actually um properties and now I want to + + + align:start position:0% +actually um properties and now I want to +go back to the succinctness because + + align:start position:0% +go back to the succinctness because + + + align:start position:0% +go back to the succinctness because +actually you're saying can't you do it + + align:start position:0% +actually you're saying can't you do it + + + align:start position:0% +actually you're saying can't you do it +with any succinct protocol and the + + align:start position:0% +with any succinct protocol and the + + + align:start position:0% +with any succinct protocol and the +answer is maybe but there's also this + + align:start position:0% +answer is maybe but there's also this + + + align:start position:0% +answer is maybe but there's also this +point which is problematic that in gkr + + align:start position:0% +point which is problematic that in gkr + + + align:start position:0% +point which is problematic that in gkr +it's nice because you just check one + + align:start position:0% +it's nice because you just check one + + + align:start position:0% +it's nice because you just check one +point in the low degree + + align:start position:0% +point in the low degree + + + align:start position:0% +point in the low degree +extension and we can verify that you do + + align:start position:0% +extension and we can verify that you do + + + align:start position:0% +extension and we can verify that you do +the low degree + + align:start position:0% +the low degree + + + align:start position:0% +the low degree +extension there there's a low deegree + + align:start position:0% +extension there there's a low deegree + + + align:start position:0% +extension there there's a low deegree +test that I didn't talk to you about but + + align:start position:0% +test that I didn't talk to you about but + + + align:start position:0% +test that I didn't talk to you about but +we'll mention that after the break so + + align:start position:0% +we'll mention that after the break so + + + align:start position:0% +we'll mention that after the break so +there's a uh gkr you can verify the + + align:start position:0% +there's a uh gkr you can verify the + + + align:start position:0% +there's a uh gkr you can verify the +verifier to verify all he needs to do is + + align:start position:0% +verifier to verify all he needs to do is + + + align:start position:0% +verifier to verify all he needs to do is +take his input and compute only one + + align:start position:0% +take his input and compute only one + + + align:start position:0% +take his input and compute only one +point two points in the low degree + + align:start position:0% +point two points in the low degree + + + align:start position:0% +point two points in the low degree +extension of that + + align:start position:0% +extension of that + + + align:start position:0% +extension of that +input this is actually used here + + align:start position:0% +input this is actually used here + + + align:start position:0% +input this is actually used here +because now the ver the prover the + + align:start position:0% +because now the ver the prover the + + + align:start position:0% +because now the ver the prover the +verifier doesn't have the input the + + align:start position:0% +verifier doesn't have the input the + + + align:start position:0% +verifier doesn't have the input the +witness the prover has it he's going to + + align:start position:0% +witness the prover has it he's going to + + + align:start position:0% +witness the prover has it he's going to +put it in the in the sky and now you + + align:start position:0% +put it in the in the sky and now you + + + align:start position:0% +put it in the in the sky and now you +can't read the entire input that's a + + align:start position:0% +can't read the entire input that's a + + + align:start position:0% +can't read the entire input that's a +witness but you can read like you know + + align:start position:0% +witness but you can read like you know + + + align:start position:0% +witness but you can read like you know +what the what what the kind of succinct + + align:start position:0% +what the what what the kind of succinct + + + align:start position:0% +what the what what the kind of succinct +protocol tells you to read you know and + + align:start position:0% +protocol tells you to read you know and + + + align:start position:0% +protocol tells you to read you know and +so this this part is is important in the + + align:start position:0% +so this this part is is important in the + + + align:start position:0% +so this this part is is important in the +G + + align:start position:0% + + + + align:start position:0% + +okay a questions before we break okay so + + align:start position:0% +okay a questions before we break okay so + + + align:start position:0% +okay a questions before we break okay so +after the we'll take a five minutes + + align:start position:0% +after the we'll take a five minutes + + + align:start position:0% +after the we'll take a five minutes +break and then we'll talk quickly about + + align:start position:0% +break and then we'll talk quickly about + + + align:start position:0% +break and then we'll talk quickly about +the low degree test wrap up the + + align:start position:0% +the low degree test wrap up the + + + align:start position:0% +the low degree test wrap up the +information Theory and go to + + align:start position:0% +information Theory and go to + + + align:start position:0% +information Theory and go to +cryptography okay \ No newline at end of file diff --git a/L98VIorbFB0.txt b/L98VIorbFB0.txt new file mode 100644 index 0000000000000000000000000000000000000000..f70e683762c35ad20c1ccd2514c086c9c4213858 --- /dev/null +++ b/L98VIorbFB0.txt @@ -0,0 +1,2719 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Ladies and gentlemen, +welcome to + +lecture number 9. + +In this lecture, I would like +to discuss with you the + +solution of equilibrium +equations in static analysis. + +In the earlier lectures, we +derived equations KU equals R. + +And we now have to solve +these equations for the + +displacements stored +in the vector U. + +This is an important phase of +the finite element analysis, + +because much of the +computational effort goes into + +the solution of these +equations. + +In the earliest finite element +analyses, iterative methods + +were used, among them the +Gauss-Seidel method. + +Now, the basic disadvantage of +using an iterative method is + +that we do not know how many +iterations have to be + +performed for solution, and thus +it is very difficult to + +estimate the total solution +effort to solve the equations + +KU equals R. Now we use almost +exclusively direct methods, or + +computer programs that are in +industry, in abundance use, + +are basically using +direct methods. + +And these direct methods are +basically variations of Gauss + +elimination, a method that +Gauss some 100 years ago + +proposed for the solution +of equations. + +Now we are talking about +static condensation, + +substructuring, frontal +solution, LDL transpose + +factorization, Cholesky +decomposition. + +We are also talking about the +crude method, the column + +reduction skyline solver. + +But all of these methods are +indeed variations of the basic + +Gauss elimination procedure. + +These are direct methods +because the number of + +operations can be counted for +the solution of the equations. + +In fact, the number of +operations for a system with n + +equations, a half bandwidth m, +is 1/2 nm squared, where we of + +course use a half bandwidth +m that is + +constant for the system. + +If the bandwidth varied, some +adjustments have to be made to + +that variable m. + +A mean value has to be used. + +However, the important point is +that we actually can count + +the number of operations to +obtain the solution, which was + +not the case in the iterative +method, because we did not + +know how many iterations +have to be performed. + +What I would like to do now +in this lecture is to very + +briefly review with you how the +basic Gauss elimination is + +performed, and then I would like +to show to you how this + +method is indeed the basis +of static condensation + +substructuring, et cetera. + +We will finally also consider +the column reduction skyline + +solver, which is very +effectively used, and that is + +in fact the equation solver that +is used in Sab and the + +ADINA program. + +Well, I have prepared, as +before, some view graphs here. + +And the first view graph here +shows a system of equations. + +This is the K matrix here. + +This is a displacement vector. + +This a load vector. + +And I will show you later on a +physical system which in fact + +gives this stiffness matrix K. +But let's look now at the + +system simply as an example +for solving equations. + +In the basic Gauss elimination +procedure, + +we proceed as follows. + +We subtract a multiple of this +equation here from the second + +equation and the third equation +in order to produce + +here a 0, and to produce +here a 0. + +Well, to obtain a 0 here, we +have to take 1/5 of this + +equation, 1/5 of that equation, +and subtract it from + +this equation. + +1/5 because then we obtain a 1 +here, and that 1 knocks that 1 + +out to obtain a 0. + +We have to subtract minus 4/5 +of this equation from the + +second equation, and we +obtain a 0 here, too. + +While this process is shown on +the next view graph, the + +result of that process is +this set of equations. + +We now have produced our +0 here, our 0 here. + +Of course we had already +a 0 here. + +We will see later on that the +matrix in here, the 3-by-3 + +matrix, bounded by the dash +lines on the side, in fact + +represents a stiffness matrix. + +That's important, because a +stiffness matrix has always + +positive elements +on the diagonal. + +Otherwise it is not a +stiffness matrix. + +It does not govern a +stable structure. + +See, here we have diagonal +elements that are all + +positive, and if we can show +that in the Gauss elimination + +procedure, we are still always +producing new stiffness + +matrices, here a 3-by-3 matrix, +then we directly can + +conclude that the diagonal +elements must remain positive. + +Well, in the Gauss elimination +procedure, the same process + +that we use to obtain from the +4-by-4 or 3-by-3 system is now + +carried on to obtain, from +the 3-by-3 system, + +a new 2-by-2 system. + +This means that we have to +subtract a multiple of the + +third equation from the fourth +equation and the fifth + +equation in order to obtain +a 0 here and a 0 here. + +For example, 5/14 of the second +equation is subtracted + +from the fourth equation +to obtain a 0 here. + +The result of that operation +is this matrix here. + +Now we have a 2-by-2 +matrix here. + +Again, positive elements +on the diagonal. + +In fact, this is a 2-by-2 +stiffness matrix, as I will be + +showing to you just now. + +Finally we proceed again, once +more, with the same step, to + +produce a 0 here, which means +that we have to subtract from + +this fourth equation a +minus 20/7 divided by + +15/7 of this equation. + +And the result, then, is this +set of equations here. + +Notice that we now have a single +element here, and in + +fact, this is a stiffness +matrix, in this case, a 1-by-1 + +stiffness matrix, just one +element, that governs the + +behavior of a single spring. + +The solution off the equations +is now completed by solving + +for u4 from this relation +down here. + +This is a 1 degree of +freedom system. + +Knowing u4, we can go back to +this equation here, substitute + +u4 in, and the only unknown +variable is u3. + +We solve, therefore, u3 +from this equation. + +Now we know u4 and u3. + +We now go to this equation. + +Knowing u3 u4, the only +unknown in this + +equation here is now u2. + +We can calculate u2, and +repeating the process, we can + +calculate u1. + +A very simple, straightforward +procedure, + +but extremely powerful. + +The result of that solution +is shown here. + +Notice u1 is simply obtained +by this operation here. + +Of course, here we're having +u2 and u3 in that we + +calculated already. + +u2 is calculated here. u4 +is calculated here. + +It might be easier to actually +look at it the way we + +discussed it just now. + +We call that the back +substitution, because we are + +coming from below upwards, and +in the back substitution, we + +have u4 first. + +We then calculate u3. + +u4 is known now, remember. + +We can substitute directly u4 +into here, and we get u3. + +Knowing now u3 and u4, we can +get u2, as shown here. + +And finally, we get u2. + +This is the basic Gauss +elimination procedure, an + +extremely powerful process. + +And I would like to show you +know how this procedure + +relates to the static +condensation and relates to + +the other techniques, and how +we then actually use this + +basic Gauss elimination +procedure in an actual finite + +element program. + +Well, static condensation is the +first topic that I'd like + +to talk about. + +The basic process is here that +we are partitioning the total + +matrix into the following +parts. + +A Kaa, Kac, Kca, and Kcc part. + +The cc part goes with Uc, the +displacements Uc, which we + +want to condense +statically out. + +Notice I'm putting the degrees +of freedom that I want to + +condense out at the bottom +of the U vector. + +Well, by static condensation we +mean that we express Uc in + +terms of Ua, which this equation +here is obtained from + +the bottom equation here. + +We then substitute Uc in the +top equation here, and the + +result is this equation here. + +Notice that the results can +be remembered quite easily + +because we have here an aa, Kaa, +then we have an a here, a + +c, a cc, ca. + +Notice that one might say, just +for remembering it, that + +this c knocks out that c, this +c knocks out that c, and what + +we are left with are aa's. + +And that means an aa +here, an aa here. + +So the dimensions are compatible +of the matrices, + +and the result is, I call +it here, K bar aa. + +Of course the right-hand side +has also changed, because the + +components must have an effect +on the equation that give Ua. + +Well, let's look at this +process, called the static + +condensation process, for +our simple example. + +And in this example now, +I deliberately + +put the Kcc up here. + +In other words, the Uc degree +of freedom is now the U1. + +This is all our Uc vector only +containing now one component. + +The static condensation was +originally proposed by + +considering or statically +condensing out of the last + +equation, and that is how it's +usually used also in finite + +element analysis. + +As an example, if we have +incompatible modes, we might + +condense out the incompatible +degrees of freedom, just as + +shown here. + +Or if we have internal degrees +of freedom in finite elements + +that only that only couple with +the bound the degrees of + +freedom of a finite element, +we could condense them out + +this way, and then we would have +this as the last degree + +of freedom. + +This would be Uc degrees of +freedom, and we would condense + +them out, just as shown here. + +However, in order to show you +how the static condensation + +relates to Gauss elimination, I +want to look at the example + +that we looked at earlier +already, and this the + +partitioning I have used. + +U1 now being the UC, +U2 U4 being the + +Ua degrees of freedom. + +So I want to now statically +condense out Uc. + +The result of the K bar +aa is shown here. + +Notice we are taking this part, +this part here, this + +part here goes right there, +this vector here is this + +vector here, 1/5 is the inverse +of Kcc, and this + +vector here is that +vector there. + +Well, performing these +operations, the + +result is this one here. + +That is the result. + +And if we go back to our earlier +Gauss elimination + +procedure, we in fact notice +that this matrix, K bar aa, is + +nothing else than the matrix +that we derived from the + +4-by-4 system when we eliminated +the non-zero + +elements here. + +In other words, we subtracted in +the Gauss elimination from + +the second equation and the +third equation a multiple of + +the first equation, we +got these zeros here. + +The result was this +3-by-3 matrix. + +And that 3-by-3 matrix is +exactly this matrix. + +So what have we been doing then +in the Gauss elimination? + +We have really statically +condensed out the first degree + +of freedom, and we have obtained +a stiffness matrix, K + +bar aa, in that Gauss +elimination procedure. + +We can now also look at the +physics that we have been + +going through, and this is, +in my opinion, a very + +important part also. + +We start off with this +matrix here. + +Notice the following00 this now +is the stiffness matrix of + +this beam for the U1 to the +U4 degrees of freedom. + +This stiffness matrix actually +has been derived by finite + +differences. + +It is a nice example to show +demonstratively what happens + +in the Gauss elimination. + +Of course, we could've also used +a finite element system, + +but I chose here a finite +difference matrix, which is + +still a stiffness matrix, and +which I can use very nicely to + +show to you the basic procedures +of the Gauss + +elimination. + +So this stiffness matrix +governed this system here. + +Notice the following. + +The first column, this column +here, represents the forces. + +When I displace this node, if +you think of this as a note, + +by unity, and keep all +the other degrees + +of freedom to 0-- + +in other words, if I +put this deflected + +shape onto the beam-- + +0 displacements right here, but +a unit displacement here. + +That is a unit displacement. + +Now notice, these are the forces +that have to act at + +these degrees of freedom +in order to give + +this deflected shape. + +The force here, if I +put them here in + +blue, is 5, as an example. + +The force here is minus 4. + +The force here is 1, and the +force here turns out to be 0. + +That element, or that element, +of course, we + +have a symmetric matrix. + +And of course, in the same way, +we can interpret other + +elements in this matrix. + +1 column represents always +forces that have to act onto + +the system in order to obtain +unit displacements at 1 degree + +of freedom. + +If you look at the I's +column, then it's the + +I's degree of freedom. + +And all the other degrees +of freedom are set to 0. + +Well, if we perform our Gauss +elimination or static + +condensation-- we have shown +that it is the same-- + +on this system, in the +first step, we + +obtain a 3-by-3 matrix. + +Physically, what we have +obtained is the stiffness + +matrix of this system now. + +And the following important +point is now to be noted. + +If I look at this column just in +the same way as I looked at + +the first column of the 4-by-4 +system, then this column + +represents now the forces that +are required at these degrees + +of freedom to impose a unit +displacement here at this + +degree of freedom, this now +being unity, with 0 + +displacements here. + +And the force required +here is 14/5. + +That is the force that I have +to apply here to get a unit + +displacement here. + +At the same time, I have to +apply here a force of minus + +16/5, and I have to apply +here a force of 1. + +So I'm talking again about +forces acting onto the system + +in this matrix here. + +And these forces are stored in +the columns or the rows off + +the matrix, and in the I's +column or row, I have the + +forces required to impose a unit +displacement at the I's + +degree of freedom with all the +degrees of freedom being 0. + +And the important point is that +having performed now the + +Gauss elimination, here +I do not have + +anymore a degree of freedom. + +The system is free +to go down here. + +And that's what we mean by +static condensation, really. + +We have taken a degree of +freedom out of the system. + +Proceeding in the same way, we +obtain this 2 by 2 system. + +Now we only have 2 degrees +of freedom. + +I have condensed out this degree +of freedom and that + +degree of freedom, +which were there. + +The beam is now free to move +down here, so the deflected + +shape corresponding to U3, this +one here, would be like + +that, with 0 displacement +here, and unit + +displacement there. + +The forces required at these +degrees of freedom are stored + +in this column here. + +Now, we immediately can observe +that since we are + +talking about a physical system +into which we have to + +put energy to deform it, we +can conclude that these + +elements here must be +positive elements. + +In other words, the diagonal +elements in the stiffness + +matrices that we derive +must be positive. + +They must be positive because +if I push down the U3 degree + +of freedom to obtain a unit +displacement, surely the force + +that I have to apply here +must be positive. + +In other words, it must be a +force into the direction of + +the degree of freedom U3. + +And that means this must +be a positive element. + +So if, in a Gauss elimination +procedure, we obtain, all of a + +sudden, a negative diagonal +element, this one or that one, + +as an example, then we would +know that the structure we are + +analyzing is unstable. + +In the final step of the Gauss +elimination, we obtain a + +single degree of +freedom system. + +And that single degree +of freedom system + +behaves like that. + +Notice no more degree +of freedoms here. + +And the equation-- + +I have to apologize that this +matrix has been written a + +little bit down. + +It should be a little +bit higher. + +They should, of course, be +aligned these three. + +But basically, we have 5/6 +times U4 equals 7/6. + +And this here is really +nothing else than the + +stiffness of a spring. + +A spring K having +us a number 5/6. + +In other words, a spring +stiffness of 5/6 here. + +This is U4, the U4 degree +of freedom. + +And the force applied to +that spring is 7/6. + +We have a single degree +of freedom system. + +But notice that this single +degree of freedom system, this + +stiffness now, K equals 5/6, +contains really all the + +physical properties +of that beam. + +The effect of the other degrees +of freedom, U1, U2, + +U3, have been carried over into +this spring stiffness. + +Similarly, 7/6 is the force +which is a result off the + +other forces that were +applied to the + +other degrees of freedom. + +And now from the single degree +of freedom system, of course, + +we can solve for U4, and then we +go back to the 2 degree of + +freedom system to solve +for U3, and so on. + +By that back substitution +process, we obtain thus the + +displacement that the beam +is actually undergoing. + +So the important point is that +when we do perform Gauss + +elimination, we really operate +always on physical systems. + +We operate always from one +stiffness matrix on to another + +stiffness matrix, and the next +stiffness matrix is basically + +obtained by static +condensation. + +We are statically condensing +out 1 degree of + +freedom after the next. + +Well, if that is very well +understood, and I urge you to + +read up in the book on this +procedure, then I think you + +can very well appreciate how +the substructuring process, + +frontal solution method, +directly relates, again, to + +Gauss elimination. + +And here I summarize once the +basic procedure that we use in + +substructuring analysis. + +We really go through static +condensation on the internal + +degrees of freedom of +a substructure. + +Here I'm showing a substructure, +which is an + +assemblage, in this case, of +the plane stress 4-node + +elements, just for +illustration. + +Of course, there could be beam +elements internally here or + +externally here. + +There could be shell elements. + +Any kind of elements. + +But the important point is that +we have an assemblage of + +elements, which by itself, +of course, gives + +us a structure already. + +We use static condensation on +the internal degrees of + +freedom of the substructure. + +Well, the result, then, is a +new stiffness matrix of the + +substructure involving boundary + +degrees of freedom only. + +Let us look, then, +at this example. + +Here we have 2 degrees of +freedom at each node. + +At the boundary nodes, which are +shown solid, here, and the + +hollow points here, the +circles here are + +the internal nodes. + +2 degrees of freedom at each. + +The result is that we have a +50-by-50 stiffness matrix, + +because we have 1, 2, 3, 4, 5 +nodes along this length, and 5 + +layers this way. + +So 25 nodes times 2 degrees of +freedom per node gives us a + +50-by-50 stiffness matrix. + +Now what we do in the +substructuring analysis, we + +statically condense out the +internal degrees of freedom, + +just in the way I have shown +how we condense out in that + +beam element, in that beam +analysis, U1 to U3, the same + +way we are condensing out the +internal degrees of freedom. + +Notice that we do not need to +perform Gauss elimination from + +U1 to U3 or U4 onwards. + +We could also first deal with +U2, then with U4, then with + +U1, and then solve for U3. + +So we have really a lot of +flexibility in the Gauss + +elimination procedure. + +The important point is that now +we're using it to condense + +these internal degrees +of freedom out. + +The result, then, is a stiffness +matrix that only + +involves the boundary +degrees of freedom. + +Now in this case, we have 1, +2, 3, 4, 5 nodes here. + +Another 5 is 10. + +3 here and 3 here means 16, +times 2 means it's going to be + +is 32 by 32 stiffness matrix. + +Notice that the internal degrees +of freedom have been + +statically condensed out, which +means that if I impose, + +for example, a unit displacement +here, keeping all + +the other displacements 0 at +the other nodes, and I keep + +this one also 0, then in this +case, I would have internal + +displacements at these nodes. + +Whereas in this case, if I put +a unit displacement only + +corresponding to this degree of +freedom and keep all other + +displacements equal to 0, I +would have 0 displacements at + +these nodes, at these points. + +Here these nodes are free to go +wherever they want to go in + +the finite element solution. + +And if I put a unit displacement +on here, they + +will be taking on a +particular value. + +These nodal displacements will +take on a particular value. + +What we really have derived, +and this is important, is a + +new stiffness matrix. + +A new, we might call it, element +stiffness matrix. + +A superelement, or substructure +stiffness matrix. + +These are all equivalent words +that, however, only involve + +boundary degrees of freedom. + +This is now a new finite element +that can be used just + +as any ordinary finite element +in the assemblage process to + +obtain the stiffness matrix +of the complete structure. + +Let me show to you +a simple example. + +Here is a very simple structure, +a truss element + +that has only 3 degrees +of freedom. + +U1, U2, U3. + +The stiffness matrix of +that truss element is + +shown here as 3-by-3. + +Matrix here, we see U1, +U2, U3, and the forces + +corresponding to these degrees +of freedom, of course, are + +listed here. + +The objective in this example is +to statically condense out + +this degree of freedom, and +thus obtain a new element + +stiffness matrix that only +involve the boundary degrees + +of freedom. + +Well, the first step that I've +pursued here was to rearrange + +the equation so as to have U1 +and U3 as the top equations, + +and U2 as the bottom equation. + +So we want to do static +condensation now from the + +back, or from the bottom, the +way it's usually done. + +And it's usually done that way +because it is numerically + +effective to proceed that way. + +The result, then, +is shown here. + +We write down just +to identify, to + +use the various parts. + +This matrix here is this +2-by-2 matrix. + +This minus 20, minus 28 +is that one here. + +Here we get the Kcc inverse, +which is this part here, and + +then of course here we have +this vector, shown here. + +If we perform these +multiplications here, we + +obtain this stiffness +matrix here. + +A 1 minus 1 minus 11 with +a constant in front. + +Of course, the load vector +also has changed. + +There is a carry over from the +2 degree of freedom in to the + +1 and 3 degrees of freedom. + +The U2 degree of freedom then +can be recovered via this + +equation here, going back to +the original equation. + +The important point is that +we have now obtained the + +stiffness matrix of the truss +element, this stiffness matrix + +of the trust element, involving +U1 and U3 only. + +U2 is not anymore present. + +It has been statically +condensed out. + +The U2 will adjust itself to a +particular value, and that + +value, of course, is +given right here. + +But the stiffness matrix that +we have now here only + +corresponds to U1 and U3. + +Well, that process can then +be repeated, and we can go + +through a process that we call +multilevel substructuring. + +In other words, we don't +just go once through a + +substructuring process, but +we go repeatedly through + +substructuring processes. + +And basically, what we are doing +is we are solving the + +system of equations KU equals R +of the complete system in a + +very effective way. + +Let me show you here +an example. + +Here we have a simple +truss assemblage. + +We have 1, 2, 3, 4 elements. + +The important point +is here that the + +elements are all similar. + +The area is varying 2A1, +4A1, 8A1, 16A1. + +And what I want to do is, +I want to deal now, via + +substructuring with the +equations to obtain a very + +effective solution. + +The first step is to look at +this element, which involves + +U1 and U3 and U2. + +And here you see, once more, +a sketch of that element. + +That is the element here. + +Now I condense out U2, and +that's what we just did in the + +previous example. + +The only degrees of freedom +that we are left with, + +then, are U1 U3. + +So now we have an element +stiffness matrix, this element + +stiffness matrix, but in terms +of U1 and U3 only. + +The next step, then, +is to say, let + +us repeat this process. + +Let us now say, since we have +this element stiffness matrix + +here in terms of U1 and U3 only, +and since this adamant + +is similar to this element here, +there is only a scalar + +involved because the area is +varying as shown, from A1 to + +2A1 to 4A1 and so on, we can +use this stiffness matrix + +here, this element stiffness +matrix, which, however, is + +already a substructure the way +I've defined it, to assemble + +the stiffness matrix +corresponding to + +both of these elements. + +And that process is +schematically shown here. + +This stiffness matrix now will +involve U1, U3, and U5. + +Notice U2 is gone, and the +important point U4 is gone + +also, because I've dealt with +U2, I have statically + +condensed out U2, and by that, +of course, I also have + +statically condensed out U4 +simultaneously, because I'm + +using this element stiffness +matrix here again. + +So U4 is also gone already. + +And now all I need to do is +condense out U3, and I obtain + +a second level substructure, +which I can use again now to + +assemble this element here +with that element. + +And that is shown on the +next view graph here. + +I repeat that process using this +element here now, which + +is this part here, involving +only U1 and U5, and this + +element here, which is similar +to that element. + +Again, an area variation +there, of course. + +And I obtain an element +stiffness matrix, or a + +structural stiffness matrix, +whichever way you want to look + +at it, that involves U1, +U5, and U9 only. + +I can now statically +condense out U5. + +The only unknowns I'm left with +are U1 and U9, and of + +course then I can simply +solve for U1 and U9. + +Of course, we would have +to have also one of the + +displacement being +prescribed to + +actually perform a solution. + +Otherwise we have a rigid +body mode in the system. + +Assuming that, say, U1 is 0, we +now would impose U1 being + +0, solve for U9, go back, solve +for U5, and proceed + +backwards to solve for all +the displacements. + +The important point is that +via this substructuring + +process, a multilevel +substructuring process, we + +have saved operations. + +We have saved operations because +in this particular + +case, you see, I have condensed +out these degrees of + +freedom already, and I use this +fact in this assemblage + +process and solution in such a +way as that I do not need to + +condense out these degrees of +freedom, that I do not need to + +deal with these degrees of +freedom again, because I've + +dealt with them in effect +already by condensing out + +these degrees of freedom here. + +There are also other +advantages using + +substructuring, and one +important advantage that I + +should mention is that in the +input definition phase, we + +only need to define the +elements, nodal points, and so + +on of a typical substructure, +and we can use that definition + +in a computer program, then, +again and again, to assemble + +the complete structure. + +In other words, if I have +defined, typically for a + +high-rise building, one typical +floor, and I have + +assembled the floor stiffness +matrix with columns, beams, + +and so on, that pertain to +that floor, if I then + +statically condense out the +degrees of freedom that we + +want to condense out for that +part of the substructure, I + +can use that floor substructure, +so to say, again + +and again, to assemble the +complete building structure. + +And this means I only have to +define really the particular + +substructure input, and I +deal, then, with that + +substructure numerically, +as I have + +shown here in the example. + +The next important procedure +that I like to discuss very + +briefly with you is the +frontal solution. + +And the frontal solution really, +again, only represents + +a variation of the basic Gauss +elimination procedure. + +It represents, really, a static +condensation procedure. + +And that static condensation, +however, is performed in a + +particular way. + +And this is really where the +advantages of the frontal + +solution can lie. + +It's performed via looking +at the elements. + +Let me describe to you +the basic process. + +Here we have, as an example, a +two-dimensional plane stress + +element mesh. + +We have 4-node elements, as +shown here, element 1, element + +2, element 3, element 4, +q, q plus 1, and so on. + +In other words, there's a whole +lay of elements this + +way, and that way, and so on. + +This mesh could represent, for +example, a cantilever plate + +that acts in plane stress. + +In the frontal solution, the +solution of the KU equals R + +equation is performed +by elements. + +So we're putting in element 1, +which couples into node 1, + +node 2, node m, and +node n plus 1. + +Since the degrees of freedom +at node 1 only obtain + +stiffness from element 1, and +no other element, the + +assemblage of this element +into the global structure + +stiffness matrix gives +the only stiffness + +contribution at node 1. + +Therefore, we have the final +equations at node 1, and we + +can deal with them already. + +And that's how the frontal +solution proceeds now. + +It statically condenses out +these degrees of freedom. + +Then we move on to the +next node of element + +1, this node here. + +However, this node gets +stiffness from element + +1 and element 2. + +So in order to obtain the final +equations here, we have + +to add the element 2 stiffness +matrix to the element 1 + +stiffness matrix. + +And that means in this way, +then, of course, we obtain the + +final equation, corresponding +to node 2. + +We now can statically condense +out the degrees of + +freedom at node 2. + +We then move on to the next +node, involving element 1 and + +element 2, which +is node 3, say. + +And now we have to, however, +assemble the stiffness matrix + +of elements 3, also into the +equations that we have + +assembled already. + +Having done so, we can now use +static condensation to + +condense out these degrees +of freedom. + +We proceed, therefore, via +elements, and we are talking + +about a wave front-- + +which is this one for node 1, +this is the wave front for + +node 2, this is the +wave front-- + +in other words, what we are +saying is, the wave front + +really embodies or contains all +the elements that we need + +to have assembled before +we can condense + +out degrees of freedom. + +To condense out the degrees of +freedom at node 2, we have to + +have a wave front such +as shown here. + +We have to have assembled +element 1 and 2, because + +element 1 and element 2 give +stiffness to node 2. + +The important point is that we +are proceeding via static + +condensation from node 1 to +node 2 and so on, and this + +means really that we +are performing + +Gauss elimination again. + +The process is summarized +here once more. + +The frontal solution consists +of successive static + +condensation of nodal +degrees for freedom. + +The solution is performed +in the order + +of the element numbering. + +That's important. + +Same number of operations are +performed in the frontal + +solution as in the skyline +solution, if the element + +numbering in the wave front +solution corresponds to the + +nodal point numbering in +the skyline solution. + +So if the element numbering +in the frontal solution + +corresponds to the nodal point +numbering in the skyline + +solution, we perform in the +skyline solution, which I have + +not really talked about yet, and +that's what I want to get + +on now, the same number +of operations as + +in the frontal solution. + +By corresponding, I mean in this +particular case here, we + +would condense out in the +frontal solution the degrees + +of freedom at node 1, then 2, +then 3, then 4, and so on. + +And of course, in the skyline +solution, or in the Gauss + +elimination procedure, we also +proceed via node 1, 2, + +3, 4, and so on. + +So in this particular example, +the frontal solution and the + +skyline solution would give the +same number of operations. + +Well, let me go on to the +skyline solution, then. + +And the basis of that solution +is LDL transpose + +factorization. + +Basically again, Gauss +elimination. + +The basic step here +is the following. + +We are having our stiffness +matrix, K here, and now I'm + +going back to that example which +I discussed earlier, the + +beam example. + +We're talking about the 4-by-4 +stiffness matrix again. + +We're using this stiffness +matrix, and we premultiply it + +by an L1 inverse matrix, +this matrix here. + +In fact we never perform +formally this + +premultiplication via matrix, +because what this does is, it + +subtracts a multiple of this +first row from the rows below + +it to update a 0 here +and a 0 there. + +That's all this +premultiplication does. + +And the result is this matrix +here, which I've shown to you + +earlier already. + +The next step is then +to operate on this + +matrix in the same way. + +However, before doing so, let me +show you here a view graph + +in which I have written out +specifically the L1 inverse. + +And the important point, L1. + +Notice that L1, the inverse of +this matrix, is obtained by + +trivial operation. + +Namely, simply changing the plus +here to a minus sign, and + +the minus sign to a plus here. + +Changing the signs of the +off-diagonal elements gives us + +directly the inverse +of that matrix. + +Well, having obtained, +therefore, via this operation, + +or having carried out via this +operation, I should say, the + +first step of the basic Gauss +elimination procedure, namely + +subtracting the top row from +the rows below it to obtain + +zeroes in the first column below +the diagonal element, we + +proceed in the same way. + +and via this procedure here-- + +now, of course, we have an L2 +inverse, and so on-- we obtain + +what we call an upper +triangular matrix. + +S, an upper triangular matrix. + +Zeroes all below the diagonal, +and only non-zero elements + +right here. + +Of course, if the matrix has a +bandwidth originally, that + +bandwidth would be preserved, +and we would have no non-zero + +elements outside that band. + +In other words, all elements +outside the band would, in + +fact, be also zero elements. + +This upper triangular matrix, +then, obtained-- + +this is the S matrix, here-- + +will be used in the +back substitution. + +This is here the element that +gives us the single degree of + +freedom stiffness, which I +talked about earlier, from + +which we can solve Un. + +Here I'm talking about +a general case with + +n degrees of freedom. + +However, looking at this +equation, let us first + +identify that we can put all of +these inverse matrices onto + +the right-hand side, and we +obtain this equation here. + +Now notice that this L1 is +obtained by trivial operation + +from L1 inverse. + +The same holds for +L2 and so on. + +So we never really had +to invert a matrix to + +obtain this part here. + +Furthermore, this L1 was an +identity matrix with only + +non-zero, off-diagonal elements +in the first column. + +This one is a matrix which +looks like the identity + +matrix, but has also non-zero, +off-diagonal elements in the + +second column. + +And so on. + +And the product of these +matrices here, then, is very + +simply obtained by writing +the 1's into the diagonal + +positions, and the off-diagonal +elements here are + +those of L1 in the first column, +those of L2 in the + +second column, and so on. + +So even this multiplication is +obtained in a very simple way. + +We only need to write the first +column of L1 into here, + +the second column of L2 +into here, the third + +column of L3 into here. + +And the result, all of that, +I call the L matrix. + +Now notice that once again, we +do not perform any matrix + +multiplication. + +We have n minus 1 matrices here, +but we do not perform a + +matrix multiplication, because +all we do is, we take the + +first column of L1 and put it +into the first column of L. + +The second column of L2 is the +second column in L. The n + +minus second column in L is +nothing else than the n minus + +second column in L n minus 2. + +And so on. + +The result, therefore, is that +we have written k equal to Lf, + +L being equal to this +product here. + +Now because K is symmetric, we +can, in fact, write this F + +matrix here as D times L +transposed, where d is a + +diagonal matrix, dii +being equal to sii. + +So now we have factorized the K +matrix into LDL transposed. + +The d elements, or the dii +elements, must all be positive + +if our structure is stable, +as I pointed out earlier. + +The Cholesky factorization, +just by remark, uses this + +form, K being L curl times L +curl transpose, where we + +should note that L curl is +really nothing else than L + +times d to the 1/2, where d to +the 1/2 is obtained by using + +the D matrix and taking +square roots of + +the diagonal elements. + +In other words, the ith +elemental of d to the 1/2 is + +nothing else than square +root out of dii. + +Well, having performed the LDL +transpose factorization, we + +now are ready to solve the +equations, and they are solved + +in the following steps. + +We have LV equals R, where V +is defined as shown here. + +Notice that if I were to put +this part into there, I really + +obtain nothing else than LDL +transpose times U equals R, + +where this is, of course, +nothing else than K times U + +equals R, if I were +to substitute + +from here into there. + +However, we separate these two +steps out, and we call this + +the forward reduction of R, +which is really obtained by + +subtracting specific elements +of R from other elements. + +We never really perform +a matrix product here. + +We write it that way, but +really, it means nothing else + +than taking, say, the ith +element off R and subtracting + +that element, or multiple of +that element, from the + +elements below it. + +That is a typical operation +performed when + +we form the V vector. + +Having obtained V, we go back to +this equation here, and we + +perform this step. + +Notice that this step is nothing +else than the division + +off the V elements by +the D elements. + +In other words, here we take +Vi and divide it by dii. + +The final step, then, is the +back substitution, which gives + +us U. The back substitution +is performed + +as I discussed earlier. + +Already we're going from UN, +from the last degree of + +freedom, upwards to calculate +the values of + +the degrees of freedom. + +Let us now look at the actual +implementation. + +The implementation has +to be performed very + +effectively, of course. + +All I have been giving to +you now so far were the + +mathematical equations that we +are basically operating on. + +The LDL transpose factorization +is, of course, a + +way of writing a set of steps +of solution that we are + +performing. + +However, we want to perform +them as effectively as + +possible, and the scheme that +we're using is related, + +really, to the crude scheme-- + +we call it the column +reduction scheme-- + +that we are going through for +the solution of the equation. + +And the procedure that we're +using is as follows. + +Here we have the stiffness +matrix. + +Notice that we only store +the upper part. + +Since we have a asymmetric +matrix, we can directly obtain + +the lower part elements from +the upper part elements. + +We do not need to store them +in the computer program. + +We also perform the Gauss +elimination in a very, you + +might say, strange way, when +you look at it first. + +And the way we're performing +it is the following. + +That we are reducing +this column first. + +In other words, we are +going column-wise. + +We are reducing this +column first. + +The result is that one. + +In the next step, then, we are +going through the reduction of + +the next column. + +See here, we are now reducing +this column, and the + +result is that one. + +The dashed line always is on +the right-hand side of that + +part of the matrix, which has +already been reduced. + +And now we are looking here at +the third column, and this is + +the reduction off the third +column The final step is then + +that we are reducing +the fourth column, + +and this is the result. + +Now notice that having performed +these operations + +column-wise-- + +and I have not given +you the details. + +We do not have time +in this lecture + +to look at the details. + +The details are in the book, if +you want to read them up. + +All I'd like to convey to you +now are the procedures that + +we're using to show you +the effectiveness. + +Notice that the final result +here in this operation is the + +D matrix on the diagonal and +the L transpose in the + +off-diagonal elements. + +And we have done +it column-wise. + +Well, what does this mean, +then, in practice? + +In practice it means +the following. + +Notice that I have now a system +which has different + +column heights for different +equations. + +The column heights are being +defined by the first non-zero + +element in a column. + +So this is the column height +for this last column here, + +because this is the +first non-zero + +element in the column. + +The zero elements below this +element here, in general, + +become non-zero elements. + +In general, not always. + +But because they in general +become non-zero elements, we + +have defined our column +height this way. + +And what we are now doing in the +actual solution is that we + +are reducing, column by column, +just the way I have + +shown it, to obtain finally the +elements of the D matrix + +on the diagonal, and the +elements of the L transpose + +matrix in the off-diagonal +elements here. + +And we can do so-- + +this is important-- + +by simply replacing elements. + +If you go back to an earlier +step that we looked at, what + +we have done here is looked at +this matrix here, and we, in + +the reduction process, simply +replaced this element by 1/5, + +replaced this element by the +minus 4 element, by minus 8/7, + +over and so on. + +So we don't need additional +storage. + +We can simply replace +elements. + +In the same way, we proceed +now here, as shown, on the + +next view graph. + +Here we have filled in the +zero element, and the + +reduction has been performed +column after column. + +The effectiveness of this whole +procedure is really seen + +on this view graph here, when +we talk about large systems. + +I want to denote here this as +a large system, because the + +high speed core storage is not +sufficient to store the + +whole matrix in. + +And so what we have been doing +is, we are storing + +the matrix in blocks. + +This is here the first block, +shown by the dashed line. + +This is the second block. + +This is the third block, and +that's the fourth block. + +What I'm saying is that we +have divided the total + +stiffness matrix into blocks, +and in fact, we divided the + +blocks in such a way as to be +able to take always at least + +two blocks into core. + +In other words, in this solution +process, we have to + +be able to take this +block into core, + +that block into core. + +Two blocks. + +We also would have to be able to +take this block into core, + +that block into core, +and so on. + +Of course, the way this is +actually automatized in a + +computer program, is that +we say we have so + +much storage available. + +Say that we have 40,000 storage +locations available. + +Then for the solution of the +equations, or for the storing + +of the stiffness matrix, +then 20,000 locations + +would be used per block. + +And what the solution routine +simply does-- it counts these + +elements and puts this dashed +line in such a way that 20,000 + +elements are in here, 20,000 +elements are in here, 20,000 + +elements are in here, +and so on. + +The solution procedure, or the +solution of the equation, is + +now performed in the +following way, + +using the block structure. + +We proceed with the reduction +off this column, of that + +column, of that column +and that column. + +Now, I should point out the +following important point. + +When we do we do reduce this +column, this column coupled + +into the first equation. + +So we have to have these +elements in core. + +Of course, since this is 1 +block, and since we can store + +that block in core anyway, +there is no problem. + +We can reduce this +column directly. + +These elements that we +already have obtained + +are indeed in core. + +Now let's go on to +the second block. + +The second block coupled into +the first block, because these + +elements here couple into +these equations. + +So in order to reduce the second +block column by column, + +we have to have the first +block in core. + +And that's what we do. + +We take this block into core and +reduce the second block. + +Having finished the second block +reduction, we go on to + +the fourth block. + +And the fourth block now is +reduced by first taking the + +first block into core, because +the first block also couples + +into the third block. + +Then taking the second block +into core together with this + +one, and reducing this one, and +then of course, finally, + +we reduce this one. + +So the general procedure, +therefore, is that we take a + +particular block into core that +we want to reduce, we + +have reduced already all the +previous blocks, we have + +storage available also for one +of the previous blocks, and we + +sequentially take the previous +blocks into core to take into + +account all the coupling that +these previous blocks have + +onto the current block that +we want to reduce. + +In this example, we're taking +this block into core. + +We then take first also +this block into core. + +That means we have two +blocks in core. + +We take the effect of +this block into + +account onto that block. + +Then we throw this book out. + +We take this block into core. + +We take the effect of this block +into account onto this + +block, and finally, we reduce +the block by itself. + +In the same way, we would +proceed with this block, just + +as another example. + +We take this block +into a core. + +This one couples into all +previous blocks, so what we + +have to do is take this into +core, and first take this into + +core, take the effect of this +coupling into account onto + +this block, throw this out, take +this one into core, put + +this block coupling onto that +block, throw this out, take + +this one into core, and finally +take the effect of + +this block coupling onto that +one into account, and finally + +then, of course, reduce +this block by itself. + +This, then, completes +the complete + +solution of a large system. + +I only was able to give you +the basic principles, the + +basic ideas. + +Some of the details are +described in the textbook, and + +you can read up there +further on it. + +Thank you very much for +your attention. + +This was all what I wanted +to say in this lecture. \ No newline at end of file diff --git a/LCiH8faydGk.txt b/LCiH8faydGk.txt new file mode 100644 index 0000000000000000000000000000000000000000..09653cdeee8c8c082954400cba63e93ba49a7010 --- /dev/null +++ b/LCiH8faydGk.txt @@ -0,0 +1,2859 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is 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courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +we're now at story board 19 panel B in + + align:start position:0% +we're now at story board 19 panel B in + + + align:start position:0% +we're now at story board 19 panel B in +the last lecture I mentioned that we're + + align:start position:0% +the last lecture I mentioned that we're + + + align:start position:0% +the last lecture I mentioned that we're +going to be looking at several special + + align:start position:0% +going to be looking at several special + + + align:start position:0% +going to be looking at several special +cases with regard to the metabolism of + + align:start position:0% +cases with regard to the metabolism of + + + align:start position:0% +cases with regard to the metabolism of +fatty acids the first special case + + align:start position:0% +fatty acids the first special case + + + align:start position:0% +fatty acids the first special case +concerns and metabolism of fatty acids + + align:start position:0% +concerns and metabolism of fatty acids + + + align:start position:0% +concerns and metabolism of fatty acids +that can already contain double bond you + + align:start position:0% +that can already contain double bond you + + + align:start position:0% +that can already contain double bond you +remember from last time that a double + + align:start position:0% +remember from last time that a double + + + align:start position:0% +remember from last time that a double +bond with a trans configuration forms + + align:start position:0% +bond with a trans configuration forms + + + align:start position:0% +bond with a trans configuration forms +naturally during beta oxidation in the + + align:start position:0% +naturally during beta oxidation in the + + + align:start position:0% +naturally during beta oxidation in the +special case we're going to look at now + + align:start position:0% +special case we're going to look at now + + + align:start position:0% +special case we're going to look at now +the double bond has a sis configuration + + align:start position:0% +the double bond has a sis configuration + + + align:start position:0% +the double bond has a sis configuration +fatty acids with a syst double bond + + align:start position:0% +fatty acids with a syst double bond + + + align:start position:0% +fatty acids with a syst double bond +typically come from membranes one of the + + align:start position:0% +typically come from membranes one of the + + + align:start position:0% +typically come from membranes one of the +ways nature plasticizers our membranes + + align:start position:0% +ways nature plasticizers our membranes + + + align:start position:0% +ways nature plasticizers our membranes +is to make them more fluid by putting in + + align:start position:0% +is to make them more fluid by putting in + + + align:start position:0% +is to make them more fluid by putting in +sis double bonds that bend the fatty + + align:start position:0% +sis double bonds that bend the fatty + + + align:start position:0% +sis double bonds that bend the fatty +acid molecule and reduce stacking + + align:start position:0% +acid molecule and reduce stacking + + + align:start position:0% +acid molecule and reduce stacking +ultimately this reduction in stacking + + align:start position:0% +ultimately this reduction in stacking + + + align:start position:0% +ultimately this reduction in stacking +results in a lowering of the overall + + align:start position:0% +results in a lowering of the overall + + + align:start position:0% +results in a lowering of the overall +melting temperature of that part of the + + align:start position:0% +melting temperature of that part of the + + + align:start position:0% +melting temperature of that part of the +membrane the example I'm going to uses + + align:start position:0% +membrane the example I'm going to uses + + + align:start position:0% +membrane the example I'm going to uses +allele coenzyme a this fatty acid a CL + + align:start position:0% +allele coenzyme a this fatty acid a CL + + + align:start position:0% +allele coenzyme a this fatty acid a CL +coenzyme a comes from oleic acid which + + align:start position:0% +coenzyme a comes from oleic acid which + + + align:start position:0% +coenzyme a comes from oleic acid which +also has the short km notation 18:1 + + align:start position:0% +also has the short km notation 18:1 + + + align:start position:0% +also has the short km notation 18:1 +Delta 9 that is there is a double bond + + align:start position:0% +Delta 9 that is there is a double bond + + + align:start position:0% +Delta 9 that is there is a double bond +nine carbons in from the carboxylate the + + align:start position:0% +nine carbons in from the carboxylate the + + + align:start position:0% +nine carbons in from the carboxylate the +reaction I've shown in panel B goes + + align:start position:0% +reaction I've shown in panel B goes + + + align:start position:0% +reaction I've shown in panel B goes +through three rounds of beta oxidation + + align:start position:0% +through three rounds of beta oxidation + + + align:start position:0% +through three rounds of beta oxidation +resulting in a sis + + align:start position:0% +resulting in a sis + + + align:start position:0% +resulting in a sis +Delta three inwe'll coenzyme a the + + align:start position:0% +Delta three inwe'll coenzyme a the + + + align:start position:0% +Delta three inwe'll coenzyme a the +enzyme Olli Weil coenzyme a isomerase + + align:start position:0% +enzyme Olli Weil coenzyme a isomerase + + + align:start position:0% +enzyme Olli Weil coenzyme a isomerase +will then remove the acidic hydrogen + + align:start position:0% +will then remove the acidic hydrogen + + + align:start position:0% +will then remove the acidic hydrogen +from the two carbon repositioning the + + align:start position:0% +from the two carbon repositioning the + + + align:start position:0% +from the two carbon repositioning the +double bond and then putting that double + + align:start position:0% +double bond and then putting that double + + + align:start position:0% +double bond and then putting that double +bond into trans configuration which is + + align:start position:0% +bond into trans configuration which is + + + align:start position:0% +bond into trans configuration which is +now amenable to further hydration and + + align:start position:0% +now amenable to further hydration and + + + align:start position:0% +now amenable to further hydration and +beta oxidation + + align:start position:0% +beta oxidation + + + align:start position:0% +beta oxidation +overall the isomerase has taken this + + align:start position:0% +overall the isomerase has taken this + + + align:start position:0% +overall the isomerase has taken this +double bond and repositioned it to make + + align:start position:0% +double bond and repositioned it to make + + + align:start position:0% +double bond and repositioned it to make +it a trans double bond that is now able + + align:start position:0% +it a trans double bond that is now able + + + align:start position:0% +it a trans double bond that is now able +to undergo further oxidation by the + + align:start position:0% +to undergo further oxidation by the + + + align:start position:0% +to undergo further oxidation by the +classical beta oxidation pathway let's + + align:start position:0% +classical beta oxidation pathway let's + + + align:start position:0% +classical beta oxidation pathway let's +turn now to panel C of story board 19 + + align:start position:0% +turn now to panel C of story board 19 + + + align:start position:0% +turn now to panel C of story board 19 +second special case that I'd like to + + align:start position:0% +second special case that I'd like to + + + align:start position:0% +second special case that I'd like to +deal with concerns the way that we + + align:start position:0% +deal with concerns the way that we + + + align:start position:0% +deal with concerns the way that we +metabolize fatty acids that have an + + align:start position:0% +metabolize fatty acids that have an + + + align:start position:0% +metabolize fatty acids that have an +uneven that is odd number of carbons in + + align:start position:0% +uneven that is odd number of carbons in + + + align:start position:0% +uneven that is odd number of carbons in +them one example would be the C 15 fatty + + align:start position:0% +them one example would be the C 15 fatty + + + align:start position:0% +them one example would be the C 15 fatty +acid Penta decanoic acid which we get + + align:start position:0% +acid Penta decanoic acid which we get + + + align:start position:0% +acid Penta decanoic acid which we get +from milk fat in this case six rounds of + + align:start position:0% +from milk fat in this case six rounds of + + + align:start position:0% +from milk fat in this case six rounds of +beta oxidation will release six acetyl + + align:start position:0% +beta oxidation will release six acetyl + + + align:start position:0% +beta oxidation will release six acetyl +coenzyme a s but note that we're left + + align:start position:0% +coenzyme a s but note that we're left + + + align:start position:0% +coenzyme a s but note that we're left +with a three carbon residue a carboxylic + + align:start position:0% +with a three carbon residue a carboxylic + + + align:start position:0% +with a three carbon residue a carboxylic +acid called propionyl coenzyme a nature + + align:start position:0% +acid called propionyl coenzyme a nature + + + align:start position:0% +acid called propionyl coenzyme a nature +doesn't like to throw anything away + + align:start position:0% +doesn't like to throw anything away + + + align:start position:0% +doesn't like to throw anything away +it's going to take this three carbon + + align:start position:0% +it's going to take this three carbon + + + align:start position:0% +it's going to take this three carbon +molecule propene ilk away that doesn't + + align:start position:0% +molecule propene ilk away that doesn't + + + align:start position:0% +molecule propene ilk away that doesn't +easily integrate into any other + + align:start position:0% +easily integrate into any other + + + align:start position:0% +easily integrate into any other +biochemical pathways nature is going to + + align:start position:0% +biochemical pathways nature is going to + + + align:start position:0% +biochemical pathways nature is going to +add a carbon to it hence making it into + + align:start position:0% +add a carbon to it hence making it into + + + align:start position:0% +add a carbon to it hence making it into +a four carbon molecule as we'll see that + + align:start position:0% +a four carbon molecule as we'll see that + + + align:start position:0% +a four carbon molecule as we'll see that +four carbon molecule will integrate + + align:start position:0% +four carbon molecule will integrate + + + align:start position:0% +four carbon molecule will integrate +seamlessly into the TCA cycle the + + align:start position:0% +seamlessly into the TCA cycle the + + + align:start position:0% +seamlessly into the TCA cycle the +conversion of the three carbon compound + + align:start position:0% +conversion of the three carbon compound + + + align:start position:0% +conversion of the three carbon compound +into a four carbon compound begins with + + align:start position:0% +into a four carbon compound begins with + + + align:start position:0% +into a four carbon compound begins with +the enzyme propionyl coenzyme a + + align:start position:0% +the enzyme propionyl coenzyme a + + + align:start position:0% +the enzyme propionyl coenzyme a +carboxylase in a few minutes we'll look + + align:start position:0% +carboxylase in a few minutes we'll look + + + align:start position:0% +carboxylase in a few minutes we'll look +at these fine details of how this enzyme + + align:start position:0% +at these fine details of how this enzyme + + + align:start position:0% +at these fine details of how this enzyme +works for now however what it does is + + align:start position:0% +works for now however what it does is + + + align:start position:0% +works for now however what it does is +use the cofactor biotin in order to + + align:start position:0% +use the cofactor biotin in order to + + + align:start position:0% +use the cofactor biotin in order to +introduce a carbon dioxide or co2 into + + align:start position:0% +introduce a carbon dioxide or co2 into + + + align:start position:0% +introduce a carbon dioxide or co2 into +the two carbon or of the propionyl + + align:start position:0% +the two carbon or of the propionyl + + + align:start position:0% +the two carbon or of the propionyl +coenzyme a the two carbon is the middle + + align:start position:0% +coenzyme a the two carbon is the middle + + + align:start position:0% +coenzyme a the two carbon is the middle +carbon of the propia neill group this is + + align:start position:0% +carbon of the propia neill group this is + + + align:start position:0% +carbon of the propia neill group this is +now a branched molecule that's called + + align:start position:0% +now a branched molecule that's called + + + align:start position:0% +now a branched molecule that's called +methylmalonyl coenzyme a next the + + align:start position:0% +methylmalonyl coenzyme a next the + + + align:start position:0% +methylmalonyl coenzyme a next the +molecule is subjected to a carbon chain + + align:start position:0% +molecule is subjected to a carbon chain + + + align:start position:0% +molecule is subjected to a carbon chain +rearrangement that takes the branched + + align:start position:0% +rearrangement that takes the branched + + + align:start position:0% +rearrangement that takes the branched +molecule and linearizes it to form + + align:start position:0% +molecule and linearizes it to form + + + align:start position:0% +molecule and linearizes it to form +succinylcholine Sime a sectional + + align:start position:0% +succinylcholine Sime a sectional + + + align:start position:0% +succinylcholine Sime a sectional +coenzyme a will then enter it directly + + align:start position:0% +coenzyme a will then enter it directly + + + align:start position:0% +coenzyme a will then enter it directly +into the TCA cycle to allow its carbons + + align:start position:0% +into the TCA cycle to allow its carbons + + + align:start position:0% +into the TCA cycle to allow its carbons +to be metabolized fully to co2 in + + align:start position:0% +to be metabolized fully to co2 in + + + align:start position:0% +to be metabolized fully to co2 in +summary nature puts a co2 into the three + + align:start position:0% +summary nature puts a co2 into the three + + + align:start position:0% +summary nature puts a co2 into the three +carbon propia neill co a forming a four + + align:start position:0% +carbon propia neill co a forming a four + + + align:start position:0% +carbon propia neill co a forming a four +carbon branch structure then in an + + align:start position:0% +carbon branch structure then in an + + + align:start position:0% +carbon branch structure then in an +amazing rearrangement that we'll look at + + align:start position:0% +amazing rearrangement that we'll look at + + + align:start position:0% +amazing rearrangement that we'll look at +later the branch molecule is made linear + + align:start position:0% +later the branch molecule is made linear + + + align:start position:0% +later the branch molecule is made linear +forming succinylcholine tur mediate so + + align:start position:0% +forming succinylcholine tur mediate so + + + align:start position:0% +forming succinylcholine tur mediate so +the otherwise useless c3 molecule + + align:start position:0% +the otherwise useless c3 molecule + + + align:start position:0% +the otherwise useless c3 molecule +propionyl coenzyme a is converted to + + align:start position:0% +propionyl coenzyme a is converted to + + + align:start position:0% +propionyl coenzyme a is converted to +something of value lastly let's turn to + + align:start position:0% +something of value lastly let's turn to + + + align:start position:0% +something of value lastly let's turn to +panel D I'm going to deal more with the + + align:start position:0% +panel D I'm going to deal more with the + + + align:start position:0% +panel D I'm going to deal more with the +details of this reaction in a few + + align:start position:0% +details of this reaction in a few + + + align:start position:0% +details of this reaction in a few +minutes but for now what I'd like to say + + align:start position:0% +minutes but for now what I'd like to say + + + align:start position:0% +minutes but for now what I'd like to say +is that there are many sources + + align:start position:0% +is that there are many sources + + + align:start position:0% +is that there are many sources +appropriate + + align:start position:0% +appropriate + + + align:start position:0% +appropriate +not just from odd chain fatty acids in + + align:start position:0% +not just from odd chain fatty acids in + + + align:start position:0% +not just from odd chain fatty acids in +the diet secondly the introduction of + + align:start position:0% +the diet secondly the introduction of + + + align:start position:0% +the diet secondly the introduction of +succinate into the TCA cycle results in + + align:start position:0% +succinate into the TCA cycle results in + + + align:start position:0% +succinate into the TCA cycle results in +an increase in the amount of carbon + + align:start position:0% +an increase in the amount of carbon + + + align:start position:0% +an increase in the amount of carbon +going through the TCA cycle that is this + + align:start position:0% +going through the TCA cycle that is this + + + align:start position:0% +going through the TCA cycle that is this +is truly an antibiotic reaction this is + + align:start position:0% +is truly an antibiotic reaction this is + + + align:start position:0% +is truly an antibiotic reaction this is +an reaction that we can use to increase + + align:start position:0% +an reaction that we can use to increase + + + align:start position:0% +an reaction that we can use to increase +the overall rate of carbon metabolism in + + align:start position:0% +the overall rate of carbon metabolism in + + + align:start position:0% +the overall rate of carbon metabolism in +the TCA cycle we're now going to turn to + + align:start position:0% +the TCA cycle we're now going to turn to + + + align:start position:0% +the TCA cycle we're now going to turn to +storyboard 20 let's look at panel a in + + align:start position:0% +storyboard 20 let's look at panel a in + + + align:start position:0% +storyboard 20 let's look at panel a in +the last lecture on fatty acid + + align:start position:0% +the last lecture on fatty acid + + + align:start position:0% +the last lecture on fatty acid +metabolism I talked about protein Eelco + + align:start position:0% +metabolism I talked about protein Eelco + + + align:start position:0% +metabolism I talked about protein Eelco +a carboxylase which uses biotin to add a + + align:start position:0% +a carboxylase which uses biotin to add a + + + align:start position:0% +a carboxylase which uses biotin to add a +co2 moiety to the middle carbon of + + align:start position:0% +co2 moiety to the middle carbon of + + + align:start position:0% +co2 moiety to the middle carbon of +propionyl coenzyme a this lecture is a + + align:start position:0% +propionyl coenzyme a this lecture is a + + + align:start position:0% +propionyl coenzyme a this lecture is a +chemical interlude in which we're going + + align:start position:0% +chemical interlude in which we're going + + + align:start position:0% +chemical interlude in which we're going +to look at propane eel Co a carboxylase + + align:start position:0% +to look at propane eel Co a carboxylase + + + align:start position:0% +to look at propane eel Co a carboxylase +and several other car box lasers that + + align:start position:0% +and several other car box lasers that + + + align:start position:0% +and several other car box lasers that +are used in biochemistry one of these is + + align:start position:0% +are used in biochemistry one of these is + + + align:start position:0% +are used in biochemistry one of these is +acetate co8 carboxylase this carboxylase + + align:start position:0% +acetate co8 carboxylase this carboxylase + + + align:start position:0% +acetate co8 carboxylase this carboxylase +puts the co2 group onto acetyl co a to + + align:start position:0% +puts the co2 group onto acetyl co a to + + + align:start position:0% +puts the co2 group onto acetyl co a to +make malonyl-coa + + align:start position:0% +make malonyl-coa + + + align:start position:0% +make malonyl-coa +which is the precursor to fatty acids + + align:start position:0% +which is the precursor to fatty acids + + + align:start position:0% +which is the precursor to fatty acids +during the fatty acid biosynthesis + + align:start position:0% +during the fatty acid biosynthesis + + + align:start position:0% +during the fatty acid biosynthesis +reactions let's also look at panel B + + align:start position:0% +reactions let's also look at panel B + + + align:start position:0% +reactions let's also look at panel B +we're also going to be looking at + + align:start position:0% +we're also going to be looking at + + + align:start position:0% +we're also going to be looking at +pyruvate carboxylase which adds a + + align:start position:0% +pyruvate carboxylase which adds a + + + align:start position:0% +pyruvate carboxylase which adds a +carbonyl group to the pyruvic acid + + align:start position:0% +carbonyl group to the pyruvic acid + + + align:start position:0% +carbonyl group to the pyruvic acid +molecule in order to make oxaloacetate + + align:start position:0% +molecule in order to make oxaloacetate + + + align:start position:0% +molecule in order to make oxaloacetate +this is one of the anaplerotic enzymes + + align:start position:0% +this is one of the anaplerotic enzymes + + + align:start position:0% +this is one of the anaplerotic enzymes +that can increase the quantity of carbon + + align:start position:0% +that can increase the quantity of carbon + + + align:start position:0% +that can increase the quantity of carbon +going through the TCA cycle that is it + + align:start position:0% +going through the TCA cycle that is it + + + align:start position:0% +going through the TCA cycle that is it +facilitates and applause as' in the + + align:start position:0% +facilitates and applause as' in the + + + align:start position:0% +facilitates and applause as' in the +biological system let's now look at + + align:start position:0% +biological system let's now look at + + + align:start position:0% +biological system let's now look at +storyboard 21 panel a the carboxyl aces + + align:start position:0% +storyboard 21 panel a the carboxyl aces + + + align:start position:0% +storyboard 21 panel a the carboxyl aces +all use carbon dioxide as their + + align:start position:0% +all use carbon dioxide as their + + + align:start position:0% +all use carbon dioxide as their +carboxylated + + align:start position:0% +carboxylated + + + align:start position:0% +carboxylated +reagent co2 itself is not very soluble + + align:start position:0% +reagent co2 itself is not very soluble + + + align:start position:0% +reagent co2 itself is not very soluble +in water so cells use carbonic anhydrase + + align:start position:0% +in water so cells use carbonic anhydrase + + + align:start position:0% +in water so cells use carbonic anhydrase +in order to hydrate it to form carbonic + + align:start position:0% +in order to hydrate it to form carbonic + + + align:start position:0% +in order to hydrate it to form carbonic +acid the biotin carboxyl a subunit will + + align:start position:0% +acid the biotin carboxyl a subunit will + + + align:start position:0% +acid the biotin carboxyl a subunit will +then phosphorylate the carbonic acid in + + align:start position:0% +then phosphorylate the carbonic acid in + + + align:start position:0% +then phosphorylate the carbonic acid in +order to form a chemically reactive + + align:start position:0% +order to form a chemically reactive + + + align:start position:0% +order to form a chemically reactive +intermediate known as carbonyl phosphate + + align:start position:0% +intermediate known as carbonyl phosphate + + + align:start position:0% +intermediate known as carbonyl phosphate +or carboxy phosphate now carbon dioxide + + align:start position:0% +or carboxy phosphate now carbon dioxide + + + align:start position:0% +or carboxy phosphate now carbon dioxide +by virtue of its structure that is a + + align:start position:0% +by virtue of its structure that is a + + + align:start position:0% +by virtue of its structure that is a +carbon with two electronegative oxygens + + align:start position:0% +carbon with two electronegative oxygens + + + align:start position:0% +carbon with two electronegative oxygens +pulling on it is pre activated for + + align:start position:0% +pulling on it is pre activated for + + + align:start position:0% +pulling on it is pre activated for +nucleophilic attack and as I said a few + + align:start position:0% +nucleophilic attack and as I said a few + + + align:start position:0% +nucleophilic attack and as I said a few +minutes ago co2 is just not present at + + align:start position:0% +minutes ago co2 is just not present at + + + align:start position:0% +minutes ago co2 is just not present at +high enough concentration in the cell + + align:start position:0% +high enough concentration in the cell + + + align:start position:0% +high enough concentration in the cell +for it to be able to add effectively to + + align:start position:0% +for it to be able to add effectively to + + + align:start position:0% +for it to be able to add effectively to +nucleophiles a nucleophile such as the a + + align:start position:0% +nucleophiles a nucleophile such as the a + + + align:start position:0% +nucleophiles a nucleophile such as the a +midnight region of biotin + + align:start position:0% +midnight region of biotin + + + align:start position:0% +midnight region of biotin +would be an example so what the cell + + align:start position:0% +would be an example so what the cell + + + align:start position:0% +would be an example so what the cell +does is use ATP to make carbonyl + + align:start position:0% +does is use ATP to make carbonyl + + + align:start position:0% +does is use ATP to make carbonyl +phosphate which is a very water soluble + + align:start position:0% +phosphate which is a very water soluble + + + align:start position:0% +phosphate which is a very water soluble +molecule it's a very efficient delivery + + align:start position:0% +molecule it's a very efficient delivery + + + align:start position:0% +molecule it's a very efficient delivery +vehicle for carbon dioxide into the + + align:start position:0% +vehicle for carbon dioxide into the + + + align:start position:0% +vehicle for carbon dioxide into the +active site of an enzyme now let's look + + align:start position:0% +active site of an enzyme now let's look + + + align:start position:0% +active site of an enzyme now let's look +at panel B the biotin carboxylase + + align:start position:0% +at panel B the biotin carboxylase + + + align:start position:0% +at panel B the biotin carboxylase +subunit of pyruvate carboxylase has a + + align:start position:0% +subunit of pyruvate carboxylase has a + + + align:start position:0% +subunit of pyruvate carboxylase has a +biotin cofactor at the end of a 14 + + align:start position:0% +biotin cofactor at the end of a 14 + + + align:start position:0% +biotin cofactor at the end of a 14 +angstrom long swinging arm this subunit + + align:start position:0% +angstrom long swinging arm this subunit + + + align:start position:0% +angstrom long swinging arm this subunit +of the enzyme breaks the bicarbonate + + align:start position:0% +of the enzyme breaks the bicarbonate + + + align:start position:0% +of the enzyme breaks the bicarbonate +phosphate bond and releases carbon + + align:start position:0% +phosphate bond and releases carbon + + + align:start position:0% +phosphate bond and releases carbon +dioxide in high concentration in the + + align:start position:0% +dioxide in high concentration in the + + + align:start position:0% +dioxide in high concentration in the +active site biotin on the swinging arm + + align:start position:0% +active site biotin on the swinging arm + + + align:start position:0% +active site biotin on the swinging arm +then attacks the high concentration of + + align:start position:0% +then attacks the high concentration of + + + align:start position:0% +then attacks the high concentration of +carbon dioxide in order to become n + + align:start position:0% +carbon dioxide in order to become n + + + align:start position:0% +carbon dioxide in order to become n +carboxy biotin as shown in this figure + + align:start position:0% +carboxy biotin as shown in this figure + + + align:start position:0% +carboxy biotin as shown in this figure +the n carboxy biotin takes advantage of + + align:start position:0% +the n carboxy biotin takes advantage of + + + align:start position:0% +the n carboxy biotin takes advantage of +its swinging arm to move away from the + + align:start position:0% +its swinging arm to move away from the + + + align:start position:0% +its swinging arm to move away from the +active site at which it acquired the co2 + + align:start position:0% +active site at which it acquired the co2 + + + align:start position:0% +active site at which it acquired the co2 +and then move to a second site on the + + align:start position:0% +and then move to a second site on the + + + align:start position:0% +and then move to a second site on the +enzyme at which the arm releases carbon + + align:start position:0% +enzyme at which the arm releases carbon + + + align:start position:0% +enzyme at which the arm releases carbon +dioxide once again at high concentration + + align:start position:0% +dioxide once again at high concentration + + + align:start position:0% +dioxide once again at high concentration +but this time co2 is released at high + + align:start position:0% +but this time co2 is released at high + + + align:start position:0% +but this time co2 is released at high +concentration in the vicinity of the + + align:start position:0% +concentration in the vicinity of the + + + align:start position:0% +concentration in the vicinity of the +substrate pyruvate pyruvate in order to + + align:start position:0% +substrate pyruvate pyruvate in order to + + + align:start position:0% +substrate pyruvate pyruvate in order to +be a good nucleophile to acquire the co2 + + align:start position:0% +be a good nucleophile to acquire the co2 + + + align:start position:0% +be a good nucleophile to acquire the co2 +probably exists as shown in the figure + + align:start position:0% +probably exists as shown in the figure + + + align:start position:0% +probably exists as shown in the figure +as the pyruvate enolate let me review + + align:start position:0% +as the pyruvate enolate let me review + + + align:start position:0% +as the pyruvate enolate let me review +panel B at this point overall this + + align:start position:0% +panel B at this point overall this + + + align:start position:0% +panel B at this point overall this +reaction has resulted in putting a + + align:start position:0% +reaction has resulted in putting a + + + align:start position:0% +reaction has resulted in putting a +carboxylic acid residue on the 3 carbon + + align:start position:0% +carboxylic acid residue on the 3 carbon + + + align:start position:0% +carboxylic acid residue on the 3 carbon +of pyruvate and this results in the + + align:start position:0% +of pyruvate and this results in the + + + align:start position:0% +of pyruvate and this results in the +formation of oxaloacetate thus + + align:start position:0% +formation of oxaloacetate thus + + + align:start position:0% +formation of oxaloacetate thus +activation of pyruvate carboxylase will + + align:start position:0% +activation of pyruvate carboxylase will + + + align:start position:0% +activation of pyruvate carboxylase will +result in taking a molecule of pyruvate + + align:start position:0% +result in taking a molecule of pyruvate + + + align:start position:0% +result in taking a molecule of pyruvate +and converting it to oxaloacetate this + + align:start position:0% +and converting it to oxaloacetate this + + + align:start position:0% +and converting it to oxaloacetate this +anaplerotic reaction gives the ability + + align:start position:0% +anaplerotic reaction gives the ability + + + align:start position:0% +anaplerotic reaction gives the ability +to increase the volume of carbon that's + + align:start position:0% +to increase the volume of carbon that's + + + align:start position:0% +to increase the volume of carbon that's +cycling in the TCA cycle thus allowing + + align:start position:0% +cycling in the TCA cycle thus allowing + + + align:start position:0% +cycling in the TCA cycle thus allowing +you to be able to increase their overall + + align:start position:0% +you to be able to increase their overall + + + align:start position:0% +you to be able to increase their overall +rate of respiration and as I've said + + align:start position:0% +rate of respiration and as I've said + + + align:start position:0% +rate of respiration and as I've said +several times in the past oxaloacetate + + align:start position:0% +several times in the past oxaloacetate + + + align:start position:0% +several times in the past oxaloacetate +is present at rather limiting + + align:start position:0% +is present at rather limiting + + + align:start position:0% +is present at rather limiting +concentrations within the mitochondrial + + align:start position:0% +concentrations within the mitochondrial + + + align:start position:0% +concentrations within the mitochondrial +matrix so this is a very useful + + align:start position:0% +matrix so this is a very useful + + + align:start position:0% +matrix so this is a very useful +biochemical reaction at this point let's + + align:start position:0% +biochemical reaction at this point let's + + + align:start position:0% +biochemical reaction at this point let's +move on to storyboard 22 and look at + + align:start position:0% +move on to storyboard 22 and look at + + + align:start position:0% +move on to storyboard 22 and look at +panel a let me loop back now and give + + align:start position:0% +panel a let me loop back now and give + + + align:start position:0% +panel a let me loop back now and give +some bigger picture points with regard + + align:start position:0% +some bigger picture points with regard + + + align:start position:0% +some bigger picture points with regard +to carboxylate chemistry pyruvate + + align:start position:0% +to carboxylate chemistry pyruvate + + + align:start position:0% +to carboxylate chemistry pyruvate +carboxylase and the other enzymes of + + align:start position:0% +carboxylase and the other enzymes of + + + align:start position:0% +carboxylase and the other enzymes of +this class have two active sites one of + + align:start position:0% +this class have two active sites one of + + + align:start position:0% +this class have two active sites one of +them is the biotin + + align:start position:0% +them is the biotin + + + align:start position:0% +them is the biotin +box'll age domain where a biotin moiety + + align:start position:0% +box'll age domain where a biotin moiety + + + align:start position:0% +box'll age domain where a biotin moiety +covalently attached to the enzyme will + + align:start position:0% +covalently attached to the enzyme will + + + align:start position:0% +covalently attached to the enzyme will +acquire co2 let's call this step one of + + align:start position:0% +acquire co2 let's call this step one of + + + align:start position:0% +acquire co2 let's call this step one of +the reaction scheme once the blatant on + + align:start position:0% +the reaction scheme once the blatant on + + + align:start position:0% +the reaction scheme once the blatant on +the swinging arm has been n carboxylated + + align:start position:0% +the swinging arm has been n carboxylated + + + align:start position:0% +the swinging arm has been n carboxylated +as in step one the N carboxy biotin + + align:start position:0% +as in step one the N carboxy biotin + + + align:start position:0% +as in step one the N carboxy biotin +moves to site 2 where the substrate is + + align:start position:0% +moves to site 2 where the substrate is + + + align:start position:0% +moves to site 2 where the substrate is +the second site is the biotin + + align:start position:0% +the second site is the biotin + + + align:start position:0% +the second site is the biotin +transferase domain in the example I just + + align:start position:0% +transferase domain in the example I just + + + align:start position:0% +transferase domain in the example I just +used the substrate was pyruvate but it + + align:start position:0% +used the substrate was pyruvate but it + + + align:start position:0% +used the substrate was pyruvate but it +just as easily could have been another + + align:start position:0% +just as easily could have been another + + + align:start position:0% +just as easily could have been another +quote-unquote carboxylation substrate + + align:start position:0% +quote-unquote carboxylation substrate + + + align:start position:0% +quote-unquote carboxylation substrate +for example propia Neel Co a in the case + + align:start position:0% +for example propia Neel Co a in the case + + + align:start position:0% +for example propia Neel Co a in the case +of pyruvate as we just saw + + align:start position:0% +of pyruvate as we just saw + + + align:start position:0% +of pyruvate as we just saw +it's the pyruvate enolate that becomes + + align:start position:0% +it's the pyruvate enolate that becomes + + + align:start position:0% +it's the pyruvate enolate that becomes +carboxylated insight 2 in order to form + + align:start position:0% +carboxylated insight 2 in order to form + + + align:start position:0% +carboxylated insight 2 in order to form +the final product oxaloacetate this + + align:start position:0% +the final product oxaloacetate this + + + align:start position:0% +the final product oxaloacetate this +carboxylation of substrate is the second + + align:start position:0% +carboxylation of substrate is the second + + + align:start position:0% +carboxylation of substrate is the second +and final step of the overall reaction + + align:start position:0% +and final step of the overall reaction + + + align:start position:0% +and final step of the overall reaction +take a look at panel B now let me give + + align:start position:0% +take a look at panel B now let me give + + + align:start position:0% +take a look at panel B now let me give +you a second example of carboxylase + + align:start position:0% +you a second example of carboxylase + + + align:start position:0% +you a second example of carboxylase +chemistry in this case our substrate + + align:start position:0% +chemistry in this case our substrate + + + align:start position:0% +chemistry in this case our substrate +will be asked to tell coenzyme a we're + + align:start position:0% +will be asked to tell coenzyme a we're + + + align:start position:0% +will be asked to tell coenzyme a we're +going to use the same chemistry we + + align:start position:0% +going to use the same chemistry we + + + align:start position:0% +going to use the same chemistry we +described a minute ago for pyruvate but + + align:start position:0% +described a minute ago for pyruvate but + + + align:start position:0% +described a minute ago for pyruvate but +in this case it is another carboxylase + + align:start position:0% +in this case it is another carboxylase + + + align:start position:0% +in this case it is another carboxylase +acetyl co a carboxylase that picks up + + align:start position:0% +acetyl co a carboxylase that picks up + + + align:start position:0% +acetyl co a carboxylase that picks up +the co 2 residue at its carboxy + + align:start position:0% +the co 2 residue at its carboxy + + + align:start position:0% +the co 2 residue at its carboxy +transferase domain in step 2 which + + align:start position:0% +transferase domain in step 2 which + + + align:start position:0% +transferase domain in step 2 which +occurs in the carboxy transferase domain + + align:start position:0% +occurs in the carboxy transferase domain + + + align:start position:0% +occurs in the carboxy transferase domain +the substrate esse teal'c away picks up + + align:start position:0% +the substrate esse teal'c away picks up + + + align:start position:0% +the substrate esse teal'c away picks up +co 2 on its 2 carbon the one distal to + + align:start position:0% +co 2 on its 2 carbon the one distal to + + + align:start position:0% +co 2 on its 2 carbon the one distal to +the coenzyme a group to form the 3 + + align:start position:0% +the coenzyme a group to form the 3 + + + align:start position:0% +the coenzyme a group to form the 3 +carbon product malonyl coenzyme a we'll + + align:start position:0% +carbon product malonyl coenzyme a we'll + + + align:start position:0% +carbon product malonyl coenzyme a we'll +see later that the carbon dioxide that's + + align:start position:0% +see later that the carbon dioxide that's + + + align:start position:0% +see later that the carbon dioxide that's +been added to acetyl co a to form + + align:start position:0% +been added to acetyl co a to form + + + align:start position:0% +been added to acetyl co a to form +melanie Ocoee + + align:start position:0% +melanie Ocoee + + + align:start position:0% +melanie Ocoee +is an excellent leaving group millennial + + align:start position:0% +is an excellent leaving group millennial + + + align:start position:0% +is an excellent leaving group millennial +co a is the fundamental precursor to all + + align:start position:0% +co a is the fundamental precursor to all + + + align:start position:0% +co a is the fundamental precursor to all +fatty acids through the fatty acid + + align:start position:0% +fatty acids through the fatty acid + + + align:start position:0% +fatty acids through the fatty acid +biosynthesis pathway again we'll see the + + align:start position:0% +biosynthesis pathway again we'll see the + + + align:start position:0% +biosynthesis pathway again we'll see the +details of this reaction scheme later + + align:start position:0% +details of this reaction scheme later + + + align:start position:0% +details of this reaction scheme later +but keep in mind now that this is a + + align:start position:0% +but keep in mind now that this is a + + + align:start position:0% +but keep in mind now that this is a +biotin requiring reaction just as the + + align:start position:0% +biotin requiring reaction just as the + + + align:start position:0% +biotin requiring reaction just as the +one we just looked at with pyruvate + + align:start position:0% +one we just looked at with pyruvate + + + align:start position:0% +one we just looked at with pyruvate +carboxylase let's look now at panel C my + + align:start position:0% +carboxylase let's look now at panel C my + + + align:start position:0% +carboxylase let's look now at panel C my +last example of carboxylase chemistry + + align:start position:0% +last example of carboxylase chemistry + + + align:start position:0% +last example of carboxylase chemistry +will be propia Neel coenzyme a + + align:start position:0% +will be propia Neel coenzyme a + + + align:start position:0% +will be propia Neel coenzyme a +carboxylase i mentioned earlier that the + + align:start position:0% +carboxylase i mentioned earlier that the + + + align:start position:0% +carboxylase i mentioned earlier that the +breakdown of odd chain number fatty + + align:start position:0% +breakdown of odd chain number fatty + + + align:start position:0% +breakdown of odd chain number fatty +acids results in the formation of a + + align:start position:0% +acids results in the formation of a + + + align:start position:0% +acids results in the formation of a +three carbon linear fatty acid called + + align:start position:0% +three carbon linear fatty acid called + + + align:start position:0% +three carbon linear fatty acid called +propane Eelco a I also said that nature + + align:start position:0% +propane Eelco a I also said that nature + + + align:start position:0% +propane Eelco a I also said that nature +doesn't want to waste any of the + + align:start position:0% +doesn't want to waste any of the + + + align:start position:0% +doesn't want to waste any of the +carbons what she is going to do is add a + + align:start position:0% +carbons what she is going to do is add a + + + align:start position:0% +carbons what she is going to do is add a +carbon dioxide or co2 to the central + + align:start position:0% +carbon dioxide or co2 to the central + + + align:start position:0% +carbon dioxide or co2 to the central +carbon of the propia Neel group as well + + align:start position:0% +carbon of the propia Neel group as well + + + align:start position:0% +carbon of the propia Neel group as well +as fatty acids with odd numbers of + + align:start position:0% +as fatty acids with odd numbers of + + + align:start position:0% +as fatty acids with odd numbers of +carbons certain amino acids such as + + align:start position:0% +carbons certain amino acids such as + + + align:start position:0% +carbons certain amino acids such as +isoleucine methionine and baleen and + + align:start position:0% +isoleucine methionine and baleen and + + + align:start position:0% +isoleucine methionine and baleen and +threonine for example also break down to + + align:start position:0% +threonine for example also break down to + + + align:start position:0% +threonine for example also break down to +form propia neoui so what I'm going to + + align:start position:0% +form propia neoui so what I'm going to + + + align:start position:0% +form propia neoui so what I'm going to +do now is describe a fairly general + + align:start position:0% +do now is describe a fairly general + + + align:start position:0% +do now is describe a fairly general +method of metabolism that involves + + align:start position:0% +method of metabolism that involves + + + align:start position:0% +method of metabolism that involves +restructuring of the carbon chain + + align:start position:0% +restructuring of the carbon chain + + + align:start position:0% +restructuring of the carbon chain +subsequent to the carboxyl age reaction + + align:start position:0% +subsequent to the carboxyl age reaction + + + align:start position:0% +subsequent to the carboxyl age reaction +in this overall reaction a carboxylase + + align:start position:0% +in this overall reaction a carboxylase + + + align:start position:0% +in this overall reaction a carboxylase +is going to carboxylate the middle + + align:start position:0% +is going to carboxylate the middle + + + align:start position:0% +is going to carboxylate the middle +carbon of the propia neill group then + + align:start position:0% +carbon of the propia neill group then + + + align:start position:0% +carbon of the propia neill group then +following the carboxylase reaction + + align:start position:0% +following the carboxylase reaction + + + align:start position:0% +following the carboxylase reaction +there's going to be a skeletal + + align:start position:0% +there's going to be a skeletal + + + align:start position:0% +there's going to be a skeletal +rearrangement to form succinylcholine + + align:start position:0% +rearrangement to form succinylcholine + + + align:start position:0% +rearrangement to form succinylcholine +enter the TCA cycle as shown in the + + align:start position:0% +enter the TCA cycle as shown in the + + + align:start position:0% +enter the TCA cycle as shown in the +reaction scheme propionyl coenzyme a + + align:start position:0% +reaction scheme propionyl coenzyme a + + + align:start position:0% +reaction scheme propionyl coenzyme a +carboxylase carboxylates + + align:start position:0% +carboxylase carboxylates + + + align:start position:0% +carboxylase carboxylates +pro pineal co a to form a very specific + + align:start position:0% +pro pineal co a to form a very specific + + + align:start position:0% +pro pineal co a to form a very specific +stereo isomer s methyl malonyl coenzyme + + align:start position:0% +stereo isomer s methyl malonyl coenzyme + + + align:start position:0% +stereo isomer s methyl malonyl coenzyme +a please note the position of the + + align:start position:0% +a please note the position of the + + + align:start position:0% +a please note the position of the +carbonyl group that's highlighted in + + align:start position:0% +carbonyl group that's highlighted in + + + align:start position:0% +carbonyl group that's highlighted in +blue this carboxylate in blue is + + align:start position:0% +blue this carboxylate in blue is + + + align:start position:0% +blue this carboxylate in blue is +attached to a methylene carbon that has + + align:start position:0% +attached to a methylene carbon that has + + + align:start position:0% +attached to a methylene carbon that has +an inverted triangle on top of it + + align:start position:0% +an inverted triangle on top of it + + + align:start position:0% +an inverted triangle on top of it +epimer ization about the carbon with the + + align:start position:0% +epimer ization about the carbon with the + + + align:start position:0% +epimer ization about the carbon with the +triangle results in the blue carboxylate + + align:start position:0% +triangle results in the blue carboxylate + + + align:start position:0% +triangle results in the blue carboxylate +pointed down the way i've drawn it the + + align:start position:0% +pointed down the way i've drawn it the + + + align:start position:0% +pointed down the way i've drawn it the +resulting epimer is our methyl malonyl + + align:start position:0% +resulting epimer is our methyl malonyl + + + align:start position:0% +resulting epimer is our methyl malonyl +coenzyme a in the art methyl malonyl + + align:start position:0% +coenzyme a in the art methyl malonyl + + + align:start position:0% +coenzyme a in the art methyl malonyl +coenzyme a molecule I put a little lasso + + align:start position:0% +coenzyme a molecule I put a little lasso + + + align:start position:0% +coenzyme a molecule I put a little lasso +around the hydrogen atom at the + + align:start position:0% +around the hydrogen atom at the + + + align:start position:0% +around the hydrogen atom at the +methylene moiety of the molecule I've + + align:start position:0% +methylene moiety of the molecule I've + + + align:start position:0% +methylene moiety of the molecule I've +also lassoed an electron in some of the + + align:start position:0% +also lassoed an electron in some of the + + + align:start position:0% +also lassoed an electron in some of the +atoms of the coenzyme a moiety a vitamin + + align:start position:0% +atoms of the coenzyme a moiety a vitamin + + + align:start position:0% +atoms of the coenzyme a moiety a vitamin +b12 dependent enzyme called methyl + + align:start position:0% +b12 dependent enzyme called methyl + + + align:start position:0% +b12 dependent enzyme called methyl +malonyl coenzyme a mutase which contains + + align:start position:0% +malonyl coenzyme a mutase which contains + + + align:start position:0% +malonyl coenzyme a mutase which contains +an adenosylcobalamin functional group + + align:start position:0% +an adenosylcobalamin functional group + + + align:start position:0% +an adenosylcobalamin functional group +will now act on this molecule in this + + align:start position:0% +will now act on this molecule in this + + + align:start position:0% +will now act on this molecule in this +enzyme a cobalt residue is going to + + align:start position:0% +enzyme a cobalt residue is going to + + + align:start position:0% +enzyme a cobalt residue is going to +enable the formation of an adenosyl + + align:start position:0% +enable the formation of an adenosyl + + + align:start position:0% +enable the formation of an adenosyl +radical look at the book for the + + align:start position:0% +radical look at the book for the + + + align:start position:0% +radical look at the book for the +detailed mechanism but for now it's + + align:start position:0% +detailed mechanism but for now it's + + + align:start position:0% +detailed mechanism but for now it's +sufficient to say that this adenosyl + + align:start position:0% +sufficient to say that this adenosyl + + + align:start position:0% +sufficient to say that this adenosyl +radical is going to facilitate the homo + + align:start position:0% +radical is going to facilitate the homo + + + align:start position:0% +radical is going to facilitate the homo +lid excision of the bond between the + + align:start position:0% +lid excision of the bond between the + + + align:start position:0% +lid excision of the bond between the +carbon and hydrogen of the our methyl + + align:start position:0% +carbon and hydrogen of the our methyl + + + align:start position:0% +carbon and hydrogen of the our methyl +malonyl coenzyme a + + align:start position:0% +malonyl coenzyme a + + + align:start position:0% +malonyl coenzyme a +that is you're going to get a free + + align:start position:0% +that is you're going to get a free + + + align:start position:0% +that is you're going to get a free +radical formed at the carbon that has + + align:start position:0% +radical formed at the carbon that has + + + align:start position:0% +radical formed at the carbon that has +the small blue o written over it that + + align:start position:0% +the small blue o written over it that + + + align:start position:0% +the small blue o written over it that +molecule will lose its hydrogen atom + + align:start position:0% +molecule will lose its hydrogen atom + + + align:start position:0% +molecule will lose its hydrogen atom +that hydrogen atom will migrate to the + + align:start position:0% +that hydrogen atom will migrate to the + + + align:start position:0% +that hydrogen atom will migrate to the +carbon that has the small blue triangle + + align:start position:0% +carbon that has the small blue triangle + + + align:start position:0% +carbon that has the small blue triangle +coordinate Li the carbon with the small + + align:start position:0% +coordinate Li the carbon with the small + + + align:start position:0% +coordinate Li the carbon with the small +box that's part of the coenzyme a + + align:start position:0% +box that's part of the coenzyme a + + + align:start position:0% +box that's part of the coenzyme a +carbonyl group will migrate to the + + align:start position:0% +carbonyl group will migrate to the + + + align:start position:0% +carbonyl group will migrate to the +position originally occupied by the + + align:start position:0% +position originally occupied by the + + + align:start position:0% +position originally occupied by the +hydrogen atom on the carbon with the + + align:start position:0% +hydrogen atom on the carbon with the + + + align:start position:0% +hydrogen atom on the carbon with the +small o over it the skeletal + + align:start position:0% +small o over it the skeletal + + + align:start position:0% +small o over it the skeletal +rearrangement is shown here in panel C + + align:start position:0% +rearrangement is shown here in panel C + + + align:start position:0% +rearrangement is shown here in panel C +and it results in a linearization of the + + align:start position:0% +and it results in a linearization of the + + + align:start position:0% +and it results in a linearization of the +original methylmalonyl coenzyme a if we + + align:start position:0% +original methylmalonyl coenzyme a if we + + + align:start position:0% +original methylmalonyl coenzyme a if we +redraw it as in the box you'll see that + + align:start position:0% +redraw it as in the box you'll see that + + + align:start position:0% +redraw it as in the box you'll see that +you form succinylcholine xym a sectional + + align:start position:0% +you form succinylcholine xym a sectional + + + align:start position:0% +you form succinylcholine xym a sectional +coenzyme a will then feed directly into + + align:start position:0% +coenzyme a will then feed directly into + + + align:start position:0% +coenzyme a will then feed directly into +the TCA cycle this is an antibiotic + + align:start position:0% +the TCA cycle this is an antibiotic + + + align:start position:0% +the TCA cycle this is an antibiotic +reaction that is it will increase the + + align:start position:0% +reaction that is it will increase the + + + align:start position:0% +reaction that is it will increase the +volume of carbon that's rotating in the + + align:start position:0% +volume of carbon that's rotating in the + + + align:start position:0% +volume of carbon that's rotating in the +TCA cycle + + align:start position:0% +TCA cycle + + + align:start position:0% +TCA cycle +overall in the way of review the three + + align:start position:0% +overall in the way of review the three + + + align:start position:0% +overall in the way of review the three +carbon compound propia Neel coenzyme a + + align:start position:0% +carbon compound propia Neel coenzyme a + + + align:start position:0% +carbon compound propia Neel coenzyme a +by way of the carboxylase reaction is + + align:start position:0% +by way of the carboxylase reaction is + + + align:start position:0% +by way of the carboxylase reaction is +converted to a four carbon branched + + align:start position:0% +converted to a four carbon branched + + + align:start position:0% +converted to a four carbon branched +molecule called s methylmalonyl coenzyme + + align:start position:0% +molecule called s methylmalonyl coenzyme + + + align:start position:0% +molecule called s methylmalonyl coenzyme +a it's appears a ssin forms the our + + align:start position:0% +a it's appears a ssin forms the our + + + align:start position:0% +a it's appears a ssin forms the our +methyl malonyl coenzyme a which is the + + align:start position:0% +methyl malonyl coenzyme a which is the + + + align:start position:0% +methyl malonyl coenzyme a which is the +substrate for a third enzyme methyl + + align:start position:0% +substrate for a third enzyme methyl + + + align:start position:0% +substrate for a third enzyme methyl +malonyl coenzyme a mutase a vitamin b-12 + + align:start position:0% +malonyl coenzyme a mutase a vitamin b-12 + + + align:start position:0% +malonyl coenzyme a mutase a vitamin b-12 +enzyme this enzyme catalyzes a free + + align:start position:0% +enzyme this enzyme catalyzes a free + + + align:start position:0% +enzyme this enzyme catalyzes a free +radical mediated rearrangement of the + + align:start position:0% +radical mediated rearrangement of the + + + align:start position:0% +radical mediated rearrangement of the +side chains specifically one hydrogen + + align:start position:0% +side chains specifically one hydrogen + + + align:start position:0% +side chains specifically one hydrogen +and one coenzyme a functionality + + align:start position:0% +and one coenzyme a functionality + + + align:start position:0% +and one coenzyme a functionality +switched positions this rearrangement + + align:start position:0% +switched positions this rearrangement + + + align:start position:0% +switched positions this rearrangement +linearizes the molecule forming + + align:start position:0% +linearizes the molecule forming + + + align:start position:0% +linearizes the molecule forming +ultimately succinylcholine xym a which + + align:start position:0% +ultimately succinylcholine xym a which + + + align:start position:0% +ultimately succinylcholine xym a which +then flows into the TCA cycle \ No newline at end of file diff --git a/LXa9j8ZN5gU.txt b/LXa9j8ZN5gU.txt new file mode 100644 index 0000000000000000000000000000000000000000..4755e025d71ecba8d9725b5ab96a9694c362da81 --- /dev/null +++ b/LXa9j8ZN5gU.txt @@ -0,0 +1,8288 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so today uh I want to talk + + align:start position:0% +ocw.mit.edu so today uh I want to talk + + + align:start position:0% +ocw.mit.edu so today uh I want to talk +about uh now that we + + align:start position:0% +about uh now that we + + + align:start position:0% +about uh now that we +have the machinery for describing + + align:start position:0% +have the machinery for describing + + + align:start position:0% +have the machinery for describing +vibrations uh in polyatomic + + align:start position:0% +vibrations uh in polyatomic + + + align:start position:0% +vibrations uh in polyatomic +molecules um we go to the quantum + + align:start position:0% +molecules um we go to the quantum + + + align:start position:0% +molecules um we go to the quantum +mechanics and we start looking at the uh + + align:start position:0% +mechanics and we start looking at the uh + + + align:start position:0% +mechanics and we start looking at the uh +the actual behavior of real uh + + align:start position:0% +the actual behavior of real uh + + + align:start position:0% +the actual behavior of real uh +polyatomic molecules and so you know we + + align:start position:0% +polyatomic molecules and so you know we + + + align:start position:0% +polyatomic molecules and so you know we +start out with the harmonic + + align:start position:0% +start out with the harmonic + + + align:start position:0% +start out with the harmonic +oscillator basis + + align:start position:0% + + + + align:start position:0% + +set so we showed classically that we can + + align:start position:0% +set so we showed classically that we can + + + align:start position:0% +set so we showed classically that we can +take a polyatomic molecule and uh and + + align:start position:0% +take a polyatomic molecule and uh and + + + align:start position:0% +take a polyatomic molecule and uh and +solve the classical mechanics and find + + align:start position:0% +solve the classical mechanics and find + + + align:start position:0% +solve the classical mechanics and find +the normal modes we know their + + align:start position:0% +the normal modes we know their + + + align:start position:0% +the normal modes we know their +frequencies we know what they are as + + align:start position:0% +frequencies we know what they are as + + + align:start position:0% +frequencies we know what they are as +explicit combinations of internal + + align:start position:0% +explicit combinations of internal + + + align:start position:0% +explicit combinations of internal +coordinates um and the important thing + + align:start position:0% +coordinates um and the important thing + + + align:start position:0% +coordinates um and the important thing +is that there are 3 nus 6 normal modes + + align:start position:0% +is that there are 3 nus 6 normal modes + + + align:start position:0% +is that there are 3 nus 6 normal modes +and that means that the + + align:start position:0% +and that means that the + + + align:start position:0% +and that means that the +hamiltonian can be written or the zero + + align:start position:0% +hamiltonian can be written or the zero + + + align:start position:0% +hamiltonian can be written or the zero +order hamiltonian can be written as a + + align:start position:0% +order hamiltonian can be written as a + + + align:start position:0% +order hamiltonian can be written as a +sum I = 1 to 3 N - 6 + + align:start position:0% +sum I = 1 to 3 N - 6 + + + align:start position:0% +sum I = 1 to 3 N - 6 +zero + + align:start position:0% +zero + + + align:start position:0% +zero +order individual oscillator + + align:start position:0% +order individual oscillator + + + align:start position:0% +order individual oscillator +hamiltonians and this provides a + + align:start position:0% +hamiltonians and this provides a + + + align:start position:0% +hamiltonians and this provides a +normal + + align:start position:0% +normal + + + align:start position:0% +normal +mode basis + + align:start position:0% + + + + align:start position:0% + +set we can say that we have wave + + align:start position:0% +set we can say that we have wave + + + align:start position:0% +set we can say that we have wave +function uh or state vectors + + align:start position:0% +function uh or state vectors + + + align:start position:0% +function uh or state vectors +V1 v 3n- 6 which are just the product + + align:start position:0% +V1 v 3n- 6 which are just the product + + + align:start position:0% +V1 v 3n- 6 which are just the product +I = 1 to 3 N - 6 of VI + + align:start position:0% +I = 1 to 3 N - 6 of VI + + + align:start position:0% +I = 1 to 3 N - 6 of VI +I so this is + + align:start position:0% +I so this is + + + align:start position:0% +I so this is +wonderful once + + align:start position:0% +wonderful once + + + align:start position:0% +wonderful once +we can describe the normal modes we have + + align:start position:0% +we can describe the normal modes we have + + + align:start position:0% +we can describe the normal modes we have +can immediately go to quantum mechanics + + align:start position:0% +can immediately go to quantum mechanics + + + align:start position:0% +can immediately go to quantum mechanics +and we can describe we can write a + + align:start position:0% +and we can describe we can write a + + + align:start position:0% +and we can describe we can write a +complete basis set of normal mode + + align:start position:0% +complete basis set of normal mode + + + align:start position:0% +complete basis set of normal mode +oscillators with which we will deal uh + + align:start position:0% +oscillators with which we will deal uh + + + align:start position:0% +oscillators with which we will deal uh +represent all complexity that could + + align:start position:0% +represent all complexity that could + + + align:start position:0% +represent all complexity that could +occur in a real system where it's not + + align:start position:0% +occur in a real system where it's not + + + align:start position:0% +occur in a real system where it's not +harmonic and so this leads us + + align:start position:0% +harmonic and so this leads us + + + align:start position:0% +harmonic and so this leads us +to the + + align:start position:0% +to the + + + align:start position:0% +to the +standard + + align:start position:0% + + + + align:start position:0% + +model which is the anharmonically + + align:start position:0% +model which is the anharmonically + + + align:start position:0% +model which is the anharmonically +coupled harmonic + + align:start position:0% +coupled harmonic + + + align:start position:0% +coupled harmonic +oscillators so we have harmonic + + align:start position:0% +oscillators so we have harmonic + + + align:start position:0% +oscillators so we have harmonic +oscillators and we introduce harmonic + + align:start position:0% +oscillators and we introduce harmonic + + + align:start position:0% +oscillators and we introduce harmonic +coupling terms and we use what we know + + align:start position:0% +coupling terms and we use what we know + + + align:start position:0% +coupling terms and we use what we know +about creation Annihilation operators uh + + align:start position:0% +about creation Annihilation operators uh + + + align:start position:0% +about creation Annihilation operators uh +to evaluate all conceivable Matrix + + align:start position:0% +to evaluate all conceivable Matrix + + + align:start position:0% +to evaluate all conceivable Matrix +elements among these zero order states + + align:start position:0% +elements among these zero order states + + + align:start position:0% +elements among these zero order states +to describe the real + + align:start position:0% +to describe the real + + + align:start position:0% +to describe the real +problem and so when we do this we get + + align:start position:0% +problem and so when we do this we get + + + align:start position:0% +problem and so when we do this we get +what are called + + align:start position:0% + + + + align:start position:0% + +polyads we have this is an opportunity + + align:start position:0% +polyads we have this is an opportunity + + + align:start position:0% +polyads we have this is an opportunity +for unemployed perturbation theorists I + + align:start position:0% +for unemployed perturbation theorists I + + + align:start position:0% +for unemployed perturbation theorists I +mean as soon as we we do this we have + + align:start position:0% +mean as soon as we we do this we have + + + align:start position:0% +mean as soon as we we do this we have +all sorts of anharmonic terms and we can + + align:start position:0% +all sorts of anharmonic terms and we can + + + align:start position:0% +all sorts of anharmonic terms and we can +do lots of perturbation Theory and many + + align:start position:0% +do lots of perturbation Theory and many + + + align:start position:0% +do lots of perturbation Theory and many +people spend their lives doing that uh + + align:start position:0% +people spend their lives doing that uh + + + align:start position:0% +people spend their lives doing that uh +but one of the things that emerges is + + align:start position:0% +but one of the things that emerges is + + + align:start position:0% +but one of the things that emerges is +there are special cases where because of + + align:start position:0% +there are special cases where because of + + + align:start position:0% +there are special cases where because of +near integer uh ratios of the normal + + align:start position:0% +near integer uh ratios of the normal + + + align:start position:0% +near integer uh ratios of the normal +mode frequencies or combinations of the + + align:start position:0% +mode frequencies or combinations of the + + + align:start position:0% +mode frequencies or combinations of the +normal mode frequencies we get + + align:start position:0% +normal mode frequencies we get + + + align:start position:0% +normal mode frequencies we get +systematic + + align:start position:0% +systematic + + + align:start position:0% +systematic +degeneracies and so the + + align:start position:0% +degeneracies and so the + + + align:start position:0% +degeneracies and so the +antonian uh arranges itself or we + + align:start position:0% +antonian uh arranges itself or we + + + align:start position:0% +antonian uh arranges itself or we +arrange it but we recognize these near + + align:start position:0% +arrange it but we recognize these near + + + align:start position:0% +arrange it but we recognize these near +degeneracies we arrange the groups of + + align:start position:0% +degeneracies we arrange the groups of + + + align:start position:0% +degeneracies we arrange the groups of +near degenerate levels and we say okay + + align:start position:0% +near degenerate levels and we say okay + + + align:start position:0% +near degenerate levels and we say okay +now we have to diagonalize blocks of the + + align:start position:0% +now we have to diagonalize blocks of the + + + align:start position:0% +now we have to diagonalize blocks of the +hamiltonian because those states are + + align:start position:0% +hamiltonian because those states are + + + align:start position:0% +hamiltonian because those states are +coupled by off diagonal matrix elements + + align:start position:0% +coupled by off diagonal matrix elements + + + align:start position:0% +coupled by off diagonal matrix elements +that are large compared to their energy + + align:start position:0% +that are large compared to their energy + + + align:start position:0% +that are large compared to their energy +zero order energy differences and so we + + align:start position:0% +zero order energy differences and so we + + + align:start position:0% +zero order energy differences and so we +get a lot of insights into uh + + align:start position:0% +get a lot of insights into uh + + + align:start position:0% +get a lot of insights into uh +vibrational Dynamics by looking at + + align:start position:0% +vibrational Dynamics by looking at + + + align:start position:0% +vibrational Dynamics by looking at +polyads and I'm going to talk about + + align:start position:0% +polyads and I'm going to talk about + + + align:start position:0% +polyads and I'm going to talk about +polyads a lot today and + + align:start position:0% +polyads a lot today and + + + align:start position:0% +polyads a lot today and +uh there'll be scaling Matrix element + + align:start position:0% +uh there'll be scaling Matrix element + + + align:start position:0% +uh there'll be scaling Matrix element +scaling and selection + + align:start position:0% + + + + align:start position:0% + +rules that are amazingly simple and + + align:start position:0% +rules that are amazingly simple and + + + align:start position:0% +rules that are amazingly simple and +amazingly + + align:start position:0% +amazingly + + + align:start position:0% +amazingly +beautiful and as a result one can + + align:start position:0% +beautiful and as a result one can + + + align:start position:0% +beautiful and as a result one can +understand what's called intr molecular + + align:start position:0% +understand what's called intr molecular + + + align:start position:0% +understand what's called intr molecular +vibrational + + align:start position:0% +vibrational + + + align:start position:0% +vibrational +redistribution uh in a very simple + + align:start position:0% +redistribution uh in a very simple + + + align:start position:0% +redistribution uh in a very simple +mechanistic way simply by looking at the + + align:start position:0% +mechanistic way simply by looking at the + + + align:start position:0% +mechanistic way simply by looking at the +structure of these + + align:start position:0% + + + + align:start position:0% + +polyads and another thing that's + + align:start position:0% +polyads and another thing that's + + + align:start position:0% +polyads and another thing that's +surprising and wonderful is uh + + align:start position:0% +surprising and wonderful is uh + + + align:start position:0% +surprising and wonderful is uh +new uh + + align:start position:0% +new uh + + + align:start position:0% +new uh +classes of + + align:start position:0% +classes of + + + align:start position:0% +classes of +motion + + align:start position:0% +motion + + + align:start position:0% +motion +emerge so we start out with a picture + + align:start position:0% +emerge so we start out with a picture + + + align:start position:0% +emerge so we start out with a picture +expressed in terms of normal + + align:start position:0% +expressed in terms of normal + + + align:start position:0% +expressed in terms of normal +modes and uh remember the normal modes + + align:start position:0% +modes and uh remember the normal modes + + + align:start position:0% +modes and uh remember the normal modes +were explicit combination of internal + + align:start position:0% +were explicit combination of internal + + + align:start position:0% +were explicit combination of internal +displacements and + + align:start position:0% +displacements and + + + align:start position:0% +displacements and +amazingly local modes + + align:start position:0% +amazingly local modes + + + align:start position:0% +amazingly local modes +emerge local uh igen states which are + + align:start position:0% +emerge local uh igen states which are + + + align:start position:0% +emerge local uh igen states which are +predominantly local in other words + + align:start position:0% +predominantly local in other words + + + align:start position:0% +predominantly local in other words +particular internal displacements the + + align:start position:0% +particular internal displacements the + + + align:start position:0% +particular internal displacements the +things that we had to combine to make + + align:start position:0% +things that we had to combine to make + + + align:start position:0% +things that we had to combine to make +the normal modes they reemerge in all + + align:start position:0% +the normal modes they reemerge in all + + + align:start position:0% +the normal modes they reemerge in all +their + + align:start position:0% +their + + + align:start position:0% +their +glory and uh and so and there are many + + align:start position:0% +glory and uh and so and there are many + + + align:start position:0% +glory and uh and so and there are many +classes of uh organized motion that + + align:start position:0% +classes of uh organized motion that + + + align:start position:0% +classes of uh organized motion that +emerge spontaneously from this model + + align:start position:0% +emerge spontaneously from this model + + + align:start position:0% +emerge spontaneously from this model +that doesn't know about them we build a + + align:start position:0% +that doesn't know about them we build a + + + align:start position:0% +that doesn't know about them we build a +model in which we have harmonic + + align:start position:0% +model in which we have harmonic + + + align:start position:0% +model in which we have harmonic +oscillators and we have some coupling + + align:start position:0% +oscillators and we have some coupling + + + align:start position:0% +oscillators and we have some coupling +terms and the coupling terms are mostly + + align:start position:0% +terms and the coupling terms are mostly + + + align:start position:0% +terms and the coupling terms are mostly +dictated by which modes are near + + align:start position:0% +dictated by which modes are near + + + align:start position:0% +dictated by which modes are near +degenerate and so the the molecule sort + + align:start position:0% +degenerate and so the the molecule sort + + + align:start position:0% +degenerate and so the the molecule sort +of selects which are the important + + align:start position:0% +of selects which are the important + + + align:start position:0% +of selects which are the important +dynamically important and Harmon + + align:start position:0% +dynamically important and Harmon + + + align:start position:0% +dynamically important and Harmon +ities and those dynamically important + + align:start position:0% +ities and those dynamically important + + + align:start position:0% +ities and those dynamically important +anharmonicities give birth to + + align:start position:0% +anharmonicities give birth to + + + align:start position:0% +anharmonicities give birth to +qualitatively new classes of organized + + align:start position:0% +qualitatively new classes of organized + + + align:start position:0% +qualitatively new classes of organized +motion which appear in characteristic + + align:start position:0% +motion which appear in characteristic + + + align:start position:0% +motion which appear in characteristic +ways in the spectrum that we'll talk a + + align:start position:0% +ways in the spectrum that we'll talk a + + + align:start position:0% +ways in the spectrum that we'll talk a +little bit about and so one example that + + align:start position:0% +little bit about and so one example that + + + align:start position:0% +little bit about and so one example that +I expect to talk about is the uh uh + + align:start position:0% + + + + align:start position:0% + +normal to + + align:start position:0% +normal to + + + align:start position:0% +normal to +local mode Evolution and that's why I + + align:start position:0% +local mode Evolution and that's why I + + + align:start position:0% +local mode Evolution and that's why I +handed out the pages from the paper + + align:start position:0% +handed out the pages from the paper + + + align:start position:0% +handed out the pages from the paper +which you already have in Toto so I + + align:start position:0% +which you already have in Toto so I + + + align:start position:0% +which you already have in Toto so I +think I gave everybody a copy of the VOR + + align:start position:0% +think I gave everybody a copy of the VOR + + + align:start position:0% +think I gave everybody a copy of the VOR +okay so that's what we're going to do + + align:start position:0% +okay so that's what we're going to do + + + align:start position:0% +okay so that's what we're going to do +and this is + + align:start position:0% +and this is + + + align:start position:0% +and this is +uh not following the notes that I wrote + + align:start position:0% +uh not following the notes that I wrote + + + align:start position:0% +uh not following the notes that I wrote +12 years ago and so I'm doing this + + align:start position:0% +12 years ago and so I'm doing this + + + align:start position:0% +12 years ago and so I'm doing this +mostly on the Fly and so let's just see + + align:start position:0% +mostly on the Fly and so let's just see + + + align:start position:0% +mostly on the Fly and so let's just see +if I can uh make this + + align:start position:0% +if I can uh make this + + + align:start position:0% +if I can uh make this +clear okay so um we start out and we + + align:start position:0% +clear okay so um we start out and we + + + align:start position:0% +clear okay so um we start out and we +Define an effect Ive hamiltonian which + + align:start position:0% +Define an effect Ive hamiltonian which + + + align:start position:0% +Define an effect Ive hamiltonian which +is a sum of individual oscillator + + align:start position:0% +is a sum of individual oscillator + + + align:start position:0% +is a sum of individual oscillator +hamiltonians and those can be + + align:start position:0% +hamiltonians and those can be + + + align:start position:0% +hamiltonians and those can be +written uh + + align:start position:0% + + + + align:start position:0% + +as as uh uh remember Omega because we're + + align:start position:0% +as as uh uh remember Omega because we're + + + align:start position:0% +as as uh uh remember Omega because we're +spectroscopist is always in reciprocal + + align:start position:0% +spectroscopist is always in reciprocal + + + align:start position:0% +spectroscopist is always in reciprocal +centimeter units and uh uh this is + + align:start position:0% +centimeter units and uh uh this is + + + align:start position:0% +centimeter units and uh uh this is +supposed to be an energy unit so we have + + align:start position:0% +supposed to be an energy unit so we have + + + align:start position:0% +supposed to be an energy unit so we have +this factor of HC which + + align:start position:0% +this factor of HC which + + + align:start position:0% +this factor of HC which +we + + align:start position:0% +we + + + align:start position:0% +we +forget but uh to be honest and since + + align:start position:0% +forget but uh to be honest and since + + + align:start position:0% +forget but uh to be honest and since +this is a class rather than a uh um + + align:start position:0% +this is a class rather than a uh um + + + align:start position:0% +this is a class rather than a uh um +whatever okay and so uh we also know + + align:start position:0% +whatever okay and so uh we also know + + + align:start position:0% +whatever okay and so uh we also know +that this is going to be multiplied by + + align:start position:0% +that this is going to be multiplied by + + + align:start position:0% +that this is going to be multiplied by +Vi plus a half but we write v + + align:start position:0% +Vi plus a half but we write v + + + align:start position:0% +Vi plus a half but we write v +v uh in terms of creation and + + align:start position:0% +v uh in terms of creation and + + + align:start position:0% +v uh in terms of creation and +Annihilation + + align:start position:0% +Annihilation + + + align:start position:0% +Annihilation +operators or we write this as n subi + + align:start position:0% +operators or we write this as n subi + + + align:start position:0% +operators or we write this as n subi +which so this is the number + + align:start position:0% +which so this is the number + + + align:start position:0% +which so this is the number +operator and uh because it's convenient + + align:start position:0% +operator and uh because it's convenient + + + align:start position:0% +operator and uh because it's convenient +to replace this thing by the number + + align:start position:0% +to replace this thing by the number + + + align:start position:0% +to replace this thing by the number +operator whenever it appears because it + + align:start position:0% +operator whenever it appears because it + + + align:start position:0% +operator whenever it appears because it +makes the algebra + + align:start position:0% +makes the algebra + + + align:start position:0% +makes the algebra +simpler uh uh we have two symbols to + + align:start position:0% +simpler uh uh we have two symbols to + + + align:start position:0% +simpler uh uh we have two symbols to +describe pretty much the same thing + + align:start position:0% +describe pretty much the same thing + + + align:start position:0% +describe pretty much the same thing +so uh and we talked about the creation + + align:start position:0% +so uh and we talked about the creation + + + align:start position:0% +so uh and we talked about the creation +Annihilation operators earlier so you + + align:start position:0% +Annihilation operators earlier so you + + + align:start position:0% +Annihilation operators earlier so you +you know that if I have ai operating on + + align:start position:0% +you know that if I have ai operating on + + + align:start position:0% +you know that if I have ai operating on +V we get uh uh Square < TK of V vus + + align:start position:0% +V we get uh uh Square < TK of V vus + + + align:start position:0% +V we get uh uh Square < TK of V vus +one and so an AI dagger operating on V + + align:start position:0% +one and so an AI dagger operating on V + + + align:start position:0% +one and so an AI dagger operating on V +gives me V + one square square root uh + + align:start position:0% +gives me V + one square square root uh + + + align:start position:0% +gives me V + one square square root uh +v+ one here and the number that appears + + align:start position:0% +v+ one here and the number that appears + + + align:start position:0% +v+ one here and the number that appears +here is always the higher of the + + align:start position:0% +here is always the higher of the + + + align:start position:0% +here is always the higher of the +two uh quantum + + align:start position:0% +two uh quantum + + + align:start position:0% +two uh quantum +numbers and so it's very it's easily + + align:start position:0% +numbers and so it's very it's easily + + + align:start position:0% +numbers and so it's very it's easily +memorable so we have this this way of + + align:start position:0% +memorable so we have this this way of + + + align:start position:0% +memorable so we have this this way of +representing the zero order hamiltonian + + align:start position:0% +representing the zero order hamiltonian + + + align:start position:0% +representing the zero order hamiltonian +and so then we say everything else and + + align:start position:0% +and so then we say everything else and + + + align:start position:0% +and so then we say everything else and +this is not the way it's done generally + + align:start position:0% +this is not the way it's done generally + + + align:start position:0% +this is not the way it's done generally +although uh keeping with what we did for + + align:start position:0% +although uh keeping with what we did for + + + align:start position:0% +although uh keeping with what we did for +datomic molecules we say there is this + + align:start position:0% +datomic molecules we say there is this + + + align:start position:0% +datomic molecules we say there is this +zero order world and everything else + + align:start position:0% +zero order world and everything else + + + align:start position:0% +zero order world and everything else +that accounts for reality but for the + + align:start position:0% +that accounts for reality but for the + + + align:start position:0% +that accounts for reality but for the +time being I'm just going to talk about + + align:start position:0% +time being I'm just going to talk about + + + align:start position:0% +time being I'm just going to talk about +all of the nonharmonic Beyond harmonic + + align:start position:0% +all of the nonharmonic Beyond harmonic + + + align:start position:0% +all of the nonharmonic Beyond harmonic +terms as a prime rather than as a series + + align:start position:0% +terms as a prime rather than as a series + + + align:start position:0% +terms as a prime rather than as a series +expressed in terms of + + align:start position:0% +expressed in terms of + + + align:start position:0% +expressed in terms of +orders and okay so this is then a power + + align:start position:0% +orders and okay so this is then a power + + + align:start position:0% +orders and okay so this is then a power +series of Beyond harmonic remember in + + align:start position:0% +series of Beyond harmonic remember in + + + align:start position:0% +series of Beyond harmonic remember in +the harmonic oscillator there's no first + + align:start position:0% +the harmonic oscillator there's no first + + + align:start position:0% +the harmonic oscillator there's no first +derivative terms the only second + + align:start position:0% +derivative terms the only second + + + align:start position:0% +derivative terms the only second +derivative terms are the uh are the uh + + align:start position:0% +derivative terms are the uh are the uh + + + align:start position:0% +derivative terms are the uh are the uh +uh squared terms no cross terms and so + + align:start position:0% +uh squared terms no cross terms and so + + + align:start position:0% +uh squared terms no cross terms and so +the first time we encounter cross terms + + align:start position:0% +the first time we encounter cross terms + + + align:start position:0% +the first time we encounter cross terms +is at the cubic stage and uh so we have + + align:start position:0% +is at the cubic stage and uh so we have + + + align:start position:0% +is at the cubic stage and uh so we have +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh a triple sum for the + + align:start position:0% +uh a triple sum for the + + + align:start position:0% +uh a triple sum for the +cubic + + align:start position:0% +cubic + + + align:start position:0% +cubic +and it's f i j k q i q j q k now it + + align:start position:0% +and it's f i j k q i q j q k now it + + + align:start position:0% +and it's f i j k q i q j q k now it +turns out to be convenient to write + + align:start position:0% +turns out to be convenient to write + + + align:start position:0% +turns out to be convenient to write +these as unrestricted + + align:start position:0% +these as unrestricted + + + align:start position:0% +these as unrestricted +sums even though it's more natural to + + align:start position:0% +sums even though it's more natural to + + + align:start position:0% +sums even though it's more natural to +think about you know the the cubic the + + align:start position:0% +think about you know the the cubic the + + + align:start position:0% +think about you know the the cubic the +the the Cub term and the the squar Plus + + align:start position:0% +the the Cub term and the the squar Plus + + + align:start position:0% +the the Cub term and the the squar Plus +lar term times linear term as separate + + align:start position:0% +lar term times linear term as separate + + + align:start position:0% +lar term times linear term as separate +and each of them would have a different + + align:start position:0% +and each of them would have a different + + + align:start position:0% +and each of them would have a different +uh uh factor out here but uh + + align:start position:0% +uh uh factor out here but uh + + + align:start position:0% +uh uh factor out here but uh +combinatorics is much easier and it's + + align:start position:0% +combinatorics is much easier and it's + + + align:start position:0% +combinatorics is much easier and it's +much easier to program using + + align:start position:0% +much easier to program using + + + align:start position:0% +much easier to program using +unrestricted sums and so you really + + align:start position:0% +unrestricted sums and so you really + + + align:start position:0% +unrestricted sums and so you really +should use unrestricted + + align:start position:0% +should use unrestricted + + + align:start position:0% +should use unrestricted +sums and uh um and so and then there's + + align:start position:0% +sums and uh um and so and then there's + + + align:start position:0% +sums and uh um and so and then there's +the the next one the Cordic term and uh + + align:start position:0% + + + + align:start position:0% + +okay so that's what we + + align:start position:0% +okay so that's what we + + + align:start position:0% +okay so that's what we +have + + align:start position:0% +have + + + align:start position:0% +have +and this is the third derivative of the + + align:start position:0% +and this is the third derivative of the + + + align:start position:0% +and this is the third derivative of the +potential with respect to + + align:start position:0% +potential with respect to + + + align:start position:0% +potential with respect to +Qi QJ + + align:start position:0% + + + + align:start position:0% + +qk evaluated at + + align:start position:0% + + + + align:start position:0% + +equilibrium and uh + + align:start position:0% +equilibrium and uh + + + align:start position:0% +equilibrium and uh +um + + align:start position:0% + + + + align:start position:0% + +now in order to be able to make use of + + align:start position:0% +now in order to be able to make use of + + + align:start position:0% +now in order to be able to make use of +creation analiation operators and to see + + align:start position:0% +creation analiation operators and to see + + + align:start position:0% +creation analiation operators and to see +the underlying structure of the problem + + align:start position:0% +the underlying structure of the problem + + + align:start position:0% +the underlying structure of the problem +it's useful to replace the actual normal + + align:start position:0% +it's useful to replace the actual normal + + + align:start position:0% +it's useful to replace the actual normal +coordinate displacements by + + align:start position:0% +coordinate displacements by + + + align:start position:0% +coordinate displacements by +dimensionless objects and then uh + + align:start position:0% +dimensionless objects and then uh + + + align:start position:0% +dimensionless objects and then uh +replace those by the creation + + align:start position:0% +replace those by the creation + + + align:start position:0% +replace those by the creation +Annihilation operator + + align:start position:0% +Annihilation operator + + + align:start position:0% +Annihilation operator +so there is a simple prescription for + + align:start position:0% +so there is a simple prescription for + + + align:start position:0% +so there is a simple prescription for +replacing uh an + + align:start position:0% +replacing uh an + + + align:start position:0% +replacing uh an +ordinary uh coordinate with units by a + + align:start position:0% +ordinary uh coordinate with units by a + + + align:start position:0% +ordinary uh coordinate with units by a +dimensionless quantity and uh uh so we + + align:start position:0% + + + + align:start position:0% + +get so this is uh this is a factor uh + + align:start position:0% +get so this is uh this is a factor uh + + + align:start position:0% +get so this is uh this is a factor uh +this is the normal mode frequency this + + align:start position:0% +this is the normal mode frequency this + + + align:start position:0% +this is the normal mode frequency this +is a mass factor and I haven't had time + + align:start position:0% +is a mass factor and I haven't had time + + + align:start position:0% +is a mass factor and I haven't had time +to figure out what's the appropriate + + align:start position:0% +to figure out what's the appropriate + + + align:start position:0% +to figure out what's the appropriate +Mass Factor uh and that's something that + + align:start position:0% +Mass Factor uh and that's something that + + + align:start position:0% +Mass Factor uh and that's something that +uh I'm sorry about but since I made this + + align:start position:0% +uh I'm sorry about but since I made this + + + align:start position:0% +uh I'm sorry about but since I made this +up on the Fly and and we didn't I didn't + + align:start position:0% +up on the Fly and and we didn't I didn't + + + align:start position:0% +up on the Fly and and we didn't I didn't +do this either in the paper uh this Mass + + align:start position:0% +do this either in the paper uh this Mass + + + align:start position:0% +do this either in the paper uh this Mass +Factor does come out of the FG Matrix uh + + align:start position:0% +Factor does come out of the FG Matrix uh + + + align:start position:0% +Factor does come out of the FG Matrix uh +treatment but I'm not sure what it + + align:start position:0% +treatment but I'm not sure what it + + + align:start position:0% +treatment but I'm not sure what it +is but the there is a factor here that + + align:start position:0% +is but the there is a factor here that + + + align:start position:0% +is but the there is a factor here that +has dimensions of mass and it's knowable + + align:start position:0% +has dimensions of mass and it's knowable + + + align:start position:0% +has dimensions of mass and it's knowable +it's just I don't know it and going from + + align:start position:0% +it's just I don't know it and going from + + + align:start position:0% +it's just I don't know it and going from +now this Dimension quantity to the + + align:start position:0% +now this Dimension quantity to the + + + align:start position:0% +now this Dimension quantity to the +non-dimension the dimensionless quantity + + align:start position:0% +non-dimension the dimensionless quantity + + + align:start position:0% +non-dimension the dimensionless quantity +and then we write that as AI plus AI + + align:start position:0% +and then we write that as AI plus AI + + + align:start position:0% +and then we write that as AI plus AI +dagger 1 / + + align:start position:0% + + + + align:start position:0% + +two so that's the procedure we start out + + align:start position:0% +two so that's the procedure we start out + + + align:start position:0% +two so that's the procedure we start out +with this thing written out in standard + + align:start position:0% +with this thing written out in standard + + + align:start position:0% +with this thing written out in standard +form and we reduce it to something + + align:start position:0% +form and we reduce it to something + + + align:start position:0% +form and we reduce it to something +expressed entirely in terms of creation + + align:start position:0% +expressed entirely in terms of creation + + + align:start position:0% +expressed entirely in terms of creation +Annihilation and number operators + + align:start position:0% +Annihilation and number operators + + + align:start position:0% +Annihilation and number operators +and one reason for doing that is this is + + align:start position:0% +and one reason for doing that is this is + + + align:start position:0% +and one reason for doing that is this is +quantum mechanics and we have to be a + + align:start position:0% +quantum mechanics and we have to be a + + + align:start position:0% +quantum mechanics and we have to be a +little careful with commutation rules + + align:start position:0% +little careful with commutation rules + + + align:start position:0% +little careful with commutation rules +and the operator algebra is much more + + align:start position:0% +and the operator algebra is much more + + + align:start position:0% +and the operator algebra is much more +transparent if we go to this now there's + + align:start position:0% +transparent if we go to this now there's + + + align:start position:0% +transparent if we go to this now there's +more advantages we also uh although in + + align:start position:0% +more advantages we also uh although in + + + align:start position:0% +more advantages we also uh although in +the normal mode hamiltonian the momentum + + align:start position:0% +the normal mode hamiltonian the momentum + + + align:start position:0% +the normal mode hamiltonian the momentum +has + + align:start position:0% +has + + + align:start position:0% +has +disappeared um it's useful to keep in + + align:start position:0% +disappeared um it's useful to keep in + + + align:start position:0% +disappeared um it's useful to keep in +mind that if we go to a local mode + + align:start position:0% +mind that if we go to a local mode + + + align:start position:0% +mind that if we go to a local mode +hamiltonian there will be uh off dial + + align:start position:0% +hamiltonian there will be uh off dial + + + align:start position:0% +hamiltonian there will be uh off dial +Matrix elements of the + + align:start position:0% +Matrix elements of the + + + align:start position:0% +Matrix elements of the +momentum between inter uh uh we already + + align:start position:0% +momentum between inter uh uh we already + + + align:start position:0% +momentum between inter uh uh we already +know that uh if if we're writing in + + align:start position:0% +know that uh if if we're writing in + + + align:start position:0% +know that uh if if we're writing in +classical mechanics if we're writing + + align:start position:0% +classical mechanics if we're writing + + + align:start position:0% +classical mechanics if we're writing +things in terms of the internal + + align:start position:0% +things in terms of the internal + + + align:start position:0% +things in terms of the internal +coordinate displacements the s's there + + align:start position:0% +coordinate displacements the s's there + + + align:start position:0% +coordinate displacements the s's there +are off diagonal matrix elements between + + align:start position:0% +are off diagonal matrix elements between + + + align:start position:0% +are off diagonal matrix elements between +them or that they're coupled by the + + align:start position:0% +them or that they're coupled by the + + + align:start position:0% +them or that they're coupled by the +kinetic energy term and so we don't just + + align:start position:0% +kinetic energy term and so we don't just + + + align:start position:0% +kinetic energy term and so we don't just +forget about the the kinetic energy or + + align:start position:0% +forget about the the kinetic energy or + + + align:start position:0% +forget about the the kinetic energy or +the + + align:start position:0% +the + + + align:start position:0% +the +momentum the reason we can be lulled + + align:start position:0% +momentum the reason we can be lulled + + + align:start position:0% +momentum the reason we can be lulled +into this sense that we can forget about + + align:start position:0% +into this sense that we can forget about + + + align:start position:0% +into this sense that we can forget about +the momentum terms is that in the + + align:start position:0% +the momentum terms is that in the + + + align:start position:0% +the momentum terms is that in the +harmonic oscillator you only have q^2 + + align:start position:0% +harmonic oscillator you only have q^2 + + + align:start position:0% +harmonic oscillator you only have q^2 +terms I'm sorry in the harmonic + + align:start position:0% +terms I'm sorry in the harmonic + + + align:start position:0% +terms I'm sorry in the harmonic +oscillator uh you only have diagonal + + align:start position:0% +oscillator uh you only have diagonal + + + align:start position:0% +oscillator uh you only have diagonal +elements we also have in the harmonic + + align:start position:0% +elements we also have in the harmonic + + + align:start position:0% +elements we also have in the harmonic +oscillator q^ s terms and we know that + + align:start position:0% +oscillator q^ s terms and we know that + + + align:start position:0% +oscillator q^ s terms and we know that +they're going to have Matrix elements + + align:start position:0% +they're going to have Matrix elements + + + align:start position:0% +they're going to have Matrix elements +off diag and V by plus orus + + align:start position:0% +off diag and V by plus orus + + + align:start position:0% +off diag and V by plus orus +2 and we don't just forget them it just + + align:start position:0% +2 and we don't just forget them it just + + + align:start position:0% +2 and we don't just forget them it just +happens they're exactly cancelled by the + + align:start position:0% +happens they're exactly cancelled by the + + + align:start position:0% +happens they're exactly cancelled by the +off diagle by two Matrix elements of p^ + + align:start position:0% +off diagle by two Matrix elements of p^ + + + align:start position:0% +off diagle by two Matrix elements of p^ +s and as a result we get to forget about + + align:start position:0% +s and as a result we get to forget about + + + align:start position:0% +s and as a result we get to forget about +momentum but it's not gone it's just + + align:start position:0% +momentum but it's not gone it's just + + + align:start position:0% +momentum but it's not gone it's just +that in the standard uh ex the simple + + align:start position:0% +that in the standard uh ex the simple + + + align:start position:0% +that in the standard uh ex the simple +Expressions it's + + align:start position:0% +Expressions it's + + + align:start position:0% +Expressions it's +suppressed now when we go beyond the + + align:start position:0% +suppressed now when we go beyond the + + + align:start position:0% +suppressed now when we go beyond the +harmonic oscillator approximation + + align:start position:0% +harmonic oscillator approximation + + + align:start position:0% +harmonic oscillator approximation +the kinetic energy term doesn't + + align:start position:0% +the kinetic energy term doesn't + + + align:start position:0% +the kinetic energy term doesn't +change and so it's + + align:start position:0% +change and so it's + + + align:start position:0% +change and so it's +gone unless we go away from the harmonic + + align:start position:0% +gone unless we go away from the harmonic + + + align:start position:0% +gone unless we go away from the harmonic +oscillator basis set then it's not + + align:start position:0% +oscillator basis set then it's not + + + align:start position:0% +oscillator basis set then it's not +gone and so then we have to be honest + + align:start position:0% +gone and so then we have to be honest + + + align:start position:0% +gone and so then we have to be honest +about Matrix elements of p^ + + align:start position:0% +about Matrix elements of p^ + + + align:start position:0% +about Matrix elements of p^ +s okay so there's a similar operator + + align:start position:0% +s okay so there's a similar operator + + + align:start position:0% +s okay so there's a similar operator +replacement for + + align:start position:0% +replacement for + + + align:start position:0% +replacement for +p uh and uh um might as well just write + + align:start position:0% +p uh and uh um might as well just write + + + align:start position:0% +p uh and uh um might as well just write +it HR 2 pi C mu the same unknown uh Mass + + align:start position:0% +it HR 2 pi C mu the same unknown uh Mass + + + align:start position:0% +it HR 2 pi C mu the same unknown uh Mass +Factor Omega + + align:start position:0% +Factor Omega + + + align:start position:0% +Factor Omega +I uh square + + align:start position:0% +I uh square + + + align:start position:0% +I uh square +root and now we have the dimensionless + + align:start position:0% +root and now we have the dimensionless + + + align:start position:0% +root and now we have the dimensionless +momentum and that is expressed as 1 / + + align:start position:0% +momentum and that is expressed as 1 / + + + align:start position:0% +momentum and that is expressed as 1 / +2 uh time I time a dagger a i dagger + + align:start position:0% +2 uh time I time a dagger a i dagger + + + align:start position:0% +2 uh time I time a dagger a i dagger +minus a + + align:start position:0% +minus a + + + align:start position:0% +minus a +I so there's this factor of I and that's + + align:start position:0% +I so there's this factor of I and that's + + + align:start position:0% +I so there's this factor of I and that's +why in fact the uh uh the square p squ + + align:start position:0% +why in fact the uh uh the square p squ + + + align:start position:0% +why in fact the uh uh the square p squ +and q^ squ terms exactly + + align:start position:0% +and q^ squ terms exactly + + + align:start position:0% +and q^ squ terms exactly +cancel off diagonal but diagonally they + + align:start position:0% +cancel off diagonal but diagonally they + + + align:start position:0% +cancel off diagonal but diagonally they +add okay so we have uh + + align:start position:0% + + + + align:start position:0% + +that okay we're interested in the uh uh + + align:start position:0% +that okay we're interested in the uh uh + + + align:start position:0% +that okay we're interested in the uh uh +q + + align:start position:0% +q + + + align:start position:0% +q +i uh + + align:start position:0% +i uh + + + align:start position:0% +i uh +um + + align:start position:0% +um + + + align:start position:0% +um +terms that are higher than + + align:start position:0% +terms that are higher than + + + align:start position:0% +terms that are higher than +harmonic and and there are several of + + align:start position:0% +harmonic and and there are several of + + + align:start position:0% +harmonic and and there are several of +these that appear + + align:start position:0% +these that appear + + + align:start position:0% +these that appear +commonly um and it's not just because + + align:start position:0% +commonly um and it's not just because + + + align:start position:0% +commonly um and it's not just because +well it is actually because they're the + + align:start position:0% +well it is actually because they're the + + + align:start position:0% +well it is actually because they're the +lowest order uh we have often uh a + + align:start position:0% +lowest order uh we have often uh a + + + align:start position:0% +lowest order uh we have often uh a +situation + + align:start position:0% +situation + + + align:start position:0% +situation +where um we have cubic + + align:start position:0% +where um we have cubic + + + align:start position:0% +where um we have cubic +terms and they have the form uh K1 + + align:start position:0% +terms and they have the form uh K1 + + + align:start position:0% +terms and they have the form uh K1 +22 uh + + align:start position:0% +22 uh + + + align:start position:0% +22 uh +q1 squ uh q1 Q2 + + align:start position:0% +q1 squ uh q1 Q2 + + + align:start position:0% +q1 squ uh q1 Q2 +2 and + + align:start position:0% +2 and + + + align:start position:0% +2 and +uh because in the + + align:start position:0% +uh because in the + + + align:start position:0% +uh because in the +scaling when we replace Q by this + + align:start position:0% +scaling when we replace Q by this + + + align:start position:0% +scaling when we replace Q by this +dimensionless q and there's a Omega in + + align:start position:0% +dimensionless q and there's a Omega in + + + align:start position:0% +dimensionless q and there's a Omega in +the + + align:start position:0% +the + + + align:start position:0% +the +denominator every Power of + + align:start position:0% +denominator every Power of + + + align:start position:0% +denominator every Power of +Q uh results in a term which is reduced + + align:start position:0% +Q uh results in a term which is reduced + + + align:start position:0% +Q uh results in a term which is reduced +in magnitude by this uh one over square + + align:start position:0% +in magnitude by this uh one over square + + + align:start position:0% +in magnitude by this uh one over square +of Omega term and so the higher the + + align:start position:0% +of Omega term and so the higher the + + + align:start position:0% +of Omega term and so the higher the +order the more qes you have in there the + + align:start position:0% +order the more qes you have in there the + + + align:start position:0% +order the more qes you have in there the +smaller it's going to be in absolute + + align:start position:0% +smaller it's going to be in absolute + + + align:start position:0% +smaller it's going to be in absolute +strength okay so cubic terms are the + + align:start position:0% +strength okay so cubic terms are the + + + align:start position:0% +strength okay so cubic terms are the +most important generally beyond the + + align:start position:0% +most important generally beyond the + + + align:start position:0% +most important generally beyond the +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +limit and + + align:start position:0% +limit and + + + align:start position:0% +limit and +um they also are a class of term which + + align:start position:0% +um they also are a class of term which + + + align:start position:0% +um they also are a class of term which +you often encounter when Omega 1 is + + align:start position:0% +you often encounter when Omega 1 is + + + align:start position:0% +you often encounter when Omega 1 is +approximately equal to 2 Omega + + align:start position:0% +approximately equal to 2 Omega + + + align:start position:0% +approximately equal to 2 Omega +2 and and this is the case uh for Bend + + align:start position:0% +2 and and this is the case uh for Bend + + + align:start position:0% +2 and and this is the case uh for Bend +stretch + + align:start position:0% +stretch + + + align:start position:0% +stretch +interactions uh it doesn't have to be + + align:start position:0% +interactions uh it doesn't have to be + + + align:start position:0% +interactions uh it doesn't have to be +that way but bends are always lower + + align:start position:0% +that way but bends are always lower + + + align:start position:0% +that way but bends are always lower +frequency than stretches and it's + + align:start position:0% +frequency than stretches and it's + + + align:start position:0% +frequency than stretches and it's +amazing how common 2:1 resonances are + + align:start position:0% +amazing how common 2:1 resonances are + + + align:start position:0% +amazing how common 2:1 resonances are +and they have a name + + align:start position:0% +and they have a name + + + align:start position:0% +and they have a name +fairy uh fairy resonance is explicitly a + + align:start position:0% +fairy uh fairy resonance is explicitly a + + + align:start position:0% +fairy uh fairy resonance is explicitly a +cubic term of 2:1 + + align:start position:0% +cubic term of 2:1 + + + align:start position:0% +cubic term of 2:1 +resonance we could have a cubic term + + align:start position:0% +resonance we could have a cubic term + + + align:start position:0% +resonance we could have a cubic term +which is a 1: one: one resonance that + + align:start position:0% +which is a 1: one: one resonance that + + + align:start position:0% +which is a 1: one: one resonance that +would not strictly be called fairy and + + align:start position:0% +would not strictly be called fairy and + + + align:start position:0% +would not strictly be called fairy and +uh but so this is an important term that + + align:start position:0% +uh but so this is an important term that + + + align:start position:0% +uh but so this is an important term that +you would include in the hamiltonian and + + align:start position:0% +you would include in the hamiltonian and + + + align:start position:0% +you would include in the hamiltonian and +there's uh there are many quartic + + align:start position:0% +there's uh there are many quartic + + + align:start position:0% +there's uh there are many quartic +terms one of them would be something + + align:start position:0% +terms one of them would be something + + + align:start position:0% +terms one of them would be something +like + + align:start position:0% + + + + align:start position:0% + +this where Omega 1 is approximately + + align:start position:0% +this where Omega 1 is approximately + + + align:start position:0% +this where Omega 1 is approximately +equal to Omega 2 this is even more + + align:start position:0% +equal to Omega 2 this is even more + + + align:start position:0% +equal to Omega 2 this is even more +common + + align:start position:0% +common + + + align:start position:0% +common +because whenever you have two identical + + align:start position:0% +because whenever you have two identical + + + align:start position:0% +because whenever you have two identical +Moes in the + + align:start position:0% +Moes in the + + + align:start position:0% +Moes in the +molecule they're going to give rise to + + align:start position:0% +molecule they're going to give rise to + + + align:start position:0% +molecule they're going to give rise to +local + + align:start position:0% +local + + + align:start position:0% +local +frequencies uh that are equal and so + + align:start position:0% +frequencies uh that are equal and so + + + align:start position:0% +frequencies uh that are equal and so +you're + + align:start position:0% +you're + + + align:start position:0% +you're +guaranteed uh to have uh uh degeneracy + + align:start position:0% +guaranteed uh to have uh uh degeneracy + + + align:start position:0% +guaranteed uh to have uh uh degeneracy +between local uh frequencies and if + + align:start position:0% +between local uh frequencies and if + + + align:start position:0% +between local uh frequencies and if +they're degenerate then any any tiny + + align:start position:0% +they're degenerate then any any tiny + + + align:start position:0% +they're degenerate then any any tiny +little thing will mix them and so it + + align:start position:0% +little thing will mix them and so it + + + align:start position:0% +little thing will mix them and so it +turns out to be really important and so + + align:start position:0% +turns out to be really important and so + + + align:start position:0% +turns out to be really important and so +molecules with two identical uh + + align:start position:0% +molecules with two identical uh + + + align:start position:0% +molecules with two identical uh +stretchers or two identical Benders will + + align:start position:0% +stretchers or two identical Benders will + + + align:start position:0% +stretchers or two identical Benders will +give rise to this now why is it a two to + + align:start position:0% +give rise to this now why is it a two to + + + align:start position:0% +give rise to this now why is it a two to +two as opposed to a 1: one it's 2:2 + + align:start position:0% +two as opposed to a 1: one it's 2:2 + + + align:start position:0% +two as opposed to a 1: one it's 2:2 +because when there's symmetry generally + + align:start position:0% +because when there's symmetry generally + + + align:start position:0% +because when there's symmetry generally +uh one of the uh + + align:start position:0% +uh one of the uh + + + align:start position:0% +uh one of the uh +um the normal modes will be non-totally + + align:start position:0% +um the normal modes will be non-totally + + + align:start position:0% +um the normal modes will be non-totally +symmetric cuz you're making the + + align:start position:0% +symmetric cuz you're making the + + + align:start position:0% +symmetric cuz you're making the +symmetric and antisymmetric combinations + + align:start position:0% +symmetric and antisymmetric combinations + + + align:start position:0% +symmetric and antisymmetric combinations +of the two two identical + + align:start position:0% +of the two two identical + + + align:start position:0% +of the two two identical +objects and when that's + + align:start position:0% +objects and when that's + + + align:start position:0% +objects and when that's +true uh in order to have a term in the + + align:start position:0% +true uh in order to have a term in the + + + align:start position:0% +true uh in order to have a term in the +hamiltonian be non zero it has to be + + align:start position:0% +hamiltonian be non zero it has to be + + + align:start position:0% +hamiltonian be non zero it has to be +totally symmetric all terms in the + + align:start position:0% +totally symmetric all terms in the + + + align:start position:0% +totally symmetric all terms in the +hamiltonian have to be totally + + align:start position:0% +hamiltonian have to be totally + + + align:start position:0% +hamiltonian have to be totally +symmetric and so if you have uh a + + align:start position:0% +symmetric and so if you have uh a + + + align:start position:0% +symmetric and so if you have uh a +non-totally symmetric coordinate + + align:start position:0% +non-totally symmetric coordinate + + + align:start position:0% +non-totally symmetric coordinate +displacement it has to be appear as an + + align:start position:0% +displacement it has to be appear as an + + + align:start position:0% +displacement it has to be appear as an +even + + align:start position:0% +even + + + align:start position:0% +even +power and so it is a one to one + + align:start position:0% +power and so it is a one to one + + + align:start position:0% +power and so it is a one to one +resonance but it it appears in the + + align:start position:0% +resonance but it it appears in the + + + align:start position:0% +resonance but it it appears in the +hiloni as a 2:2 resonance and it's + + align:start position:0% +hiloni as a 2:2 resonance and it's + + + align:start position:0% +hiloni as a 2:2 resonance and it's +extremely + + align:start position:0% +extremely + + + align:start position:0% +extremely +common and uh uh it even though it's of + + align:start position:0% +common and uh uh it even though it's of + + + align:start position:0% +common and uh uh it even though it's of +a higher order than the cubic terms it's + + align:start position:0% +a higher order than the cubic terms it's + + + align:start position:0% +a higher order than the cubic terms it's +more common and it's more important + + align:start position:0% +more common and it's more important + + + align:start position:0% +more common and it's more important +because the resonances are more + + align:start position:0% +because the resonances are more + + + align:start position:0% +because the resonances are more +perfect and so these two are the thing + + align:start position:0% +perfect and so these two are the thing + + + align:start position:0% +perfect and so these two are the thing +and this one is called + + align:start position:0% +and this one is called + + + align:start position:0% +and this one is called +darling andison + + align:start position:0% + + + + align:start position:0% + +I never met fmy but I did meet Denson he + + align:start position:0% +I never met fmy but I did meet Denson he + + + align:start position:0% +I never met fmy but I did meet Denson he +used to be coming he used to go to the + + align:start position:0% +used to be coming he used to go to the + + + align:start position:0% +used to be coming he used to go to the +spectroscopy conference at Ohio State + + align:start position:0% +spectroscopy conference at Ohio State + + + align:start position:0% +spectroscopy conference at Ohio State +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +uh this both of these uh were first most + + align:start position:0% +uh this both of these uh were first most + + + align:start position:0% +uh this both of these uh were first most +fundamentally understood in the 1940s + + align:start position:0% +fundamentally understood in the 1940s + + + align:start position:0% +fundamentally understood in the 1940s +about the time I was born but Dennison + + align:start position:0% +about the time I was born but Dennison + + + align:start position:0% +about the time I was born but Dennison +was only 20 years or so older than I I + + align:start position:0% +was only 20 years or so older than I I + + + align:start position:0% +was only 20 years or so older than I I +no 30 so he was a very uh Old Gentleman + + align:start position:0% +no 30 so he was a very uh Old Gentleman + + + align:start position:0% +no 30 so he was a very uh Old Gentleman +when I first met him so anyway um that's + + align:start position:0% +when I first met him so anyway um that's + + + align:start position:0% +when I first met him so anyway um that's +just + + align:start position:0% +just + + + align:start position:0% +just +um so we have these kinds of resonances + + align:start position:0% +um so we have these kinds of resonances + + + align:start position:0% +um so we have these kinds of resonances +that we want to deal + + align:start position:0% +that we want to deal + + + align:start position:0% +that we want to deal +with + + align:start position:0% +with + + + align:start position:0% +with +okay so question about the the other + + align:start position:0% +okay so question about the the other + + + align:start position:0% +okay so question about the the other +cubic terms like the one to one to one + + align:start position:0% +cubic terms like the one to one to one + + + align:start position:0% +cubic terms like the one to one to one +res yes that you mentioned + + align:start position:0% +res yes that you mentioned + + + align:start position:0% +res yes that you mentioned +um that would also happen I guess if you + + align:start position:0% +um that would also happen I guess if you + + + align:start position:0% +um that would also happen I guess if you +have any three identical Vo + + align:start position:0% +have any three identical Vo + + + align:start position:0% +have any three identical Vo +mole well but the problem then would be + + align:start position:0% +mole well but the problem then would be + + + align:start position:0% +mole well but the problem then would be +that it's likely that one of them would + + align:start position:0% +that it's likely that one of them would + + + align:start position:0% +that it's likely that one of them would +not be totally symmetric that when you + + align:start position:0% +not be totally symmetric that when you + + + align:start position:0% +not be totally symmetric that when you +have you're combining three things that + + align:start position:0% +have you're combining three things that + + + align:start position:0% +have you're combining three things that +are identical you tend to get an a + + align:start position:0% +are identical you tend to get an a + + + align:start position:0% +are identical you tend to get an a +representation and an e + + align:start position:0% +representation and an e + + + align:start position:0% +representation and an e +representation and so you would then not + + align:start position:0% +representation and so you would then not + + + align:start position:0% +representation and so you would then not +be able to have a one to a one to one to + + align:start position:0% +be able to have a one to a one to one to + + + align:start position:0% +be able to have a one to a one to one to +one so + + align:start position:0% +one so + + + align:start position:0% +one so +um but there is a possibility that you + + align:start position:0% +um but there is a possibility that you + + + align:start position:0% +um but there is a possibility that you +have one of one that's totally symmet uh + + align:start position:0% +have one of one that's totally symmet uh + + + align:start position:0% +have one of one that's totally symmet uh +well + + align:start position:0% + + + + align:start position:0% + +um there are cases when you have a + + align:start position:0% +um there are cases when you have a + + + align:start position:0% +um there are cases when you have a +certain coordinate which not totally + + align:start position:0% +certain coordinate which not totally + + + align:start position:0% +certain coordinate which not totally +symmetric and another coordinate it's + + align:start position:0% +symmetric and another coordinate it's + + + align:start position:0% +symmetric and another coordinate it's +not but the product of the two makes so + + align:start position:0% +not but the product of the two makes so + + + align:start position:0% +not but the product of the two makes so +you you can you can have one to one to + + align:start position:0% +you you can you can have one to one to + + + align:start position:0% +you you can you can have one to one to +one where not all three of them are + + align:start position:0% +one where not all three of them are + + + align:start position:0% +one where not all three of them are +totally symmetric two of them have to be + + align:start position:0% +totally symmetric two of them have to be + + + align:start position:0% +totally symmetric two of them have to be +not or all three of them have to be not + + align:start position:0% +not or all three of them have to be not + + + align:start position:0% +not or all three of them have to be not +and depends on the the group Okay so + + align:start position:0% +and depends on the the group Okay so + + + align:start position:0% +and depends on the the group Okay so +so + + align:start position:0% +so + + + align:start position:0% +so +um for the cubic we would write the + + align:start position:0% +um for the cubic we would write the + + + align:start position:0% +um for the cubic we would write the +coupling term + + align:start position:0% +coupling term + + + align:start position:0% +coupling term +as 3 over + + align:start position:0% +as 3 over + + + align:start position:0% +as 3 over +6 uh K1 + + align:start position:0% +6 uh K1 + + + align:start position:0% +6 uh K1 + + align:start position:0% + + + align:start position:0% +q1 + + align:start position:0% +q1 + + + align:start position:0% +q1 +Q + + align:start position:0% +Q + + + align:start position:0% +Q +2^2 now we had the six because it was a + + align:start position:0% +2^2 now we had the six because it was a + + + align:start position:0% +2^2 now we had the six because it was a +cubic term and we have the three because + + align:start position:0% +cubic term and we have the three because + + + align:start position:0% +cubic term and we have the three because +we can put uh you know we can have uh + + align:start position:0% +we can put uh you know we can have uh + + + align:start position:0% +we can put uh you know we can have uh +modes one and two in any of three + + align:start position:0% +modes one and two in any of three + + + align:start position:0% +modes one and two in any of three +different orders we can put the unique + + align:start position:0% +different orders we can put the unique + + + align:start position:0% +different orders we can put the unique +term first second or third and so that + + align:start position:0% +term first second or third and so that + + + align:start position:0% +term first second or third and so that +was gives us the third the six 3 over 6 + + align:start position:0% +was gives us the third the six 3 over 6 + + + align:start position:0% +was gives us the third the six 3 over 6 +and then so that's 1 12 and then uh we + + align:start position:0% +and then so that's 1 12 and then uh we + + + align:start position:0% +and then so that's 1 12 and then uh we +can replace the these dimensionless cues + + align:start position:0% +can replace the these dimensionless cues + + + align:start position:0% +can replace the these dimensionless cues +by the creation Annihilation + + align:start position:0% +by the creation Annihilation + + + align:start position:0% +by the creation Annihilation +operators and so we get an additional + + align:start position:0% +operators and so we get an additional + + + align:start position:0% +operators and so we get an additional +factor of 1/ 2 2 + + align:start position:0% +factor of 1/ 2 2 + + + align:start position:0% +factor of 1/ 2 2 +cubed uh we have K1 22 + + align:start position:0% +cubed uh we have K1 22 + + + align:start position:0% +cubed uh we have K1 22 +in reciprocal centimeter units here and + + align:start position:0% +in reciprocal centimeter units here and + + + align:start position:0% +in reciprocal centimeter units here and +here and uh then A1 + A1 dagger A2 + A2 + + align:start position:0% +here and uh then A1 + A1 dagger A2 + A2 + + + align:start position:0% +here and uh then A1 + A1 dagger A2 + A2 +dagger qu^ squar so that's the the + + align:start position:0% +dagger qu^ squar so that's the the + + + align:start position:0% +dagger qu^ squar so that's the the +quantum mechanical operator that appears + + align:start position:0% +quantum mechanical operator that appears + + + align:start position:0% +quantum mechanical operator that appears +uh that gives rise to off diagonal + + align:start position:0% +uh that gives rise to off diagonal + + + align:start position:0% +uh that gives rise to off diagonal +elements in the uh 2:1 + + align:start position:0% +elements in the uh 2:1 + + + align:start position:0% +elements in the uh 2:1 +resonance you're absorbing the extra + + align:start position:0% +resonance you're absorbing the extra + + + align:start position:0% +resonance you're absorbing the extra +constants into the case yes + + align:start position:0% +constants into the case yes + + + align:start position:0% +constants into the case yes +you usually use Big K for that right I + + align:start position:0% +you usually use Big K for that right I + + + align:start position:0% +you usually use Big K for that right I +don't remember what I did but some of + + align:start position:0% +don't remember what I did but some of + + + align:start position:0% +don't remember what I did but some of +that was idiosyncratic and so let's make + + align:start position:0% +that was idiosyncratic and so let's make + + + align:start position:0% +that was idiosyncratic and so let's make +them big + + align:start position:0% +them big + + + align:start position:0% +them big +K okay you see here I used F instead of + + align:start position:0% +K okay you see here I used F instead of + + + align:start position:0% +K okay you see here I used F instead of +so I get uh I get so this is a big K and + + align:start position:0% +so I get uh I get so this is a big K and + + + align:start position:0% +so I get uh I get so this is a big K and +in the paper it's probably Big K right + + align:start position:0% +in the paper it's probably Big K right + + + align:start position:0% +in the paper it's probably Big K right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay so we have an off diagonal coupling + + align:start position:0% +okay so we have an off diagonal coupling + + + align:start position:0% +okay so we have an off diagonal coupling +term and + + align:start position:0% +term and + + + align:start position:0% +term and +now when you're faced with a real + + align:start position:0% +now when you're faced with a real + + + align:start position:0% +now when you're faced with a real +molecule uh normally you've done some + + align:start position:0% +molecule uh normally you've done some + + + align:start position:0% +molecule uh normally you've done some +spectroscopy or someone else has done + + align:start position:0% +spectroscopy or someone else has done + + + align:start position:0% +spectroscopy or someone else has done +some spectroscopy and so you have a a + + align:start position:0% +some spectroscopy and so you have a a + + + align:start position:0% +some spectroscopy and so you have a a +nearly complete set of uh vibrational + + align:start position:0% +nearly complete set of uh vibrational + + + align:start position:0% +nearly complete set of uh vibrational +frequencies and so you often look at + + align:start position:0% +frequencies and so you often look at + + + align:start position:0% +frequencies and so you often look at +that thing and you say oh well it looks + + align:start position:0% +that thing and you say oh well it looks + + + align:start position:0% +that thing and you say oh well it looks +like I've got a 2 to1 resonance or it + + align:start position:0% +like I've got a 2 to1 resonance or it + + + align:start position:0% +like I've got a 2 to1 resonance or it +looks like I've got a 2 to2 + + align:start position:0% +looks like I've got a 2 to2 + + + align:start position:0% +looks like I've got a 2 to2 +resonance and so I know that I ought to + + align:start position:0% +resonance and so I know that I ought to + + + align:start position:0% +resonance and so I know that I ought to +be careful about writing the + + align:start position:0% +be careful about writing the + + + align:start position:0% +be careful about writing the +hamiltonian uh in terms of uh couplings + + align:start position:0% +hamiltonian uh in terms of uh couplings + + + align:start position:0% +hamiltonian uh in terms of uh couplings +among states which are near + + align:start position:0% + + + + align:start position:0% + +degenerate and so + + align:start position:0% + + + + align:start position:0% + +uh if when you look at the list of the + + align:start position:0% +uh if when you look at the list of the + + + align:start position:0% +uh if when you look at the list of the +harmonic frequencies and one of the + + align:start position:0% +harmonic frequencies and one of the + + + align:start position:0% +harmonic frequencies and one of the +beautiful things about Spectra is that + + align:start position:0% +beautiful things about Spectra is that + + + align:start position:0% +beautiful things about Spectra is that +if you're looking in the fundamental + + align:start position:0% +if you're looking in the fundamental + + + align:start position:0% +if you're looking in the fundamental +region uh you in other words words only + + align:start position:0% +region uh you in other words words only + + + align:start position:0% +region uh you in other words words only +the the uh uh one Quantum in each of the + + align:start position:0% +the the uh uh one Quantum in each of the + + + align:start position:0% +the the uh uh one Quantum in each of the +modes there are very few uh anharmonic + + align:start position:0% +modes there are very few uh anharmonic + + + align:start position:0% +modes there are very few uh anharmonic +terms that are + + align:start position:0% +terms that are + + + align:start position:0% +terms that are +relevant and + + align:start position:0% +relevant and + + + align:start position:0% +relevant and +so and if you do some work you can get a + + align:start position:0% +so and if you do some work you can get a + + + align:start position:0% +so and if you do some work you can get a +pretty good estimate of all of the + + align:start position:0% +pretty good estimate of all of the + + + align:start position:0% +pretty good estimate of all of the +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +frequencies uh and so you can know that + + align:start position:0% +frequencies uh and so you can know that + + + align:start position:0% +frequencies uh and so you can know that +there are or are not likely to be some + + align:start position:0% +there are or are not likely to be some + + + align:start position:0% +there are or are not likely to be some +near + + align:start position:0% +near + + + align:start position:0% +near +resonances Suppose there are + + align:start position:0% +resonances Suppose there are + + + align:start position:0% +resonances Suppose there are +uh and suppose you have something that + + align:start position:0% +uh and suppose you have something that + + + align:start position:0% +uh and suppose you have something that +looks like a 2:1 resonance well then + + align:start position:0% +looks like a 2:1 resonance well then + + + align:start position:0% +looks like a 2:1 resonance well then +what you do is you say I'm going to take + + align:start position:0% +what you do is you say I'm going to take + + + align:start position:0% +what you do is you say I'm going to take +those two modes and I'm going to + + align:start position:0% +those two modes and I'm going to + + + align:start position:0% +those two modes and I'm going to +construct I'm going to organize them + + align:start position:0% +construct I'm going to organize them + + + align:start position:0% +construct I'm going to organize them +according to a meas a a new quantum + + align:start position:0% +according to a meas a a new quantum + + + align:start position:0% +according to a meas a a new quantum +number what we call a polyad quantum + + align:start position:0% +number what we call a polyad quantum + + + align:start position:0% +number what we call a polyad quantum +number which more or less keeps track of + + align:start position:0% +number which more or less keeps track of + + + align:start position:0% +number which more or less keeps track of +the near degeneracies so we say n is + + align:start position:0% +the near degeneracies so we say n is + + + align:start position:0% +the near degeneracies so we say n is +going to be equal to 2 * V1 + V2 if + + align:start position:0% +going to be equal to 2 * V1 + V2 if + + + align:start position:0% +going to be equal to 2 * V1 + V2 if +Omega 1 is approximately equal to 2 + + align:start position:0% +Omega 1 is approximately equal to 2 + + + align:start position:0% +Omega 1 is approximately equal to 2 +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +2 one Quantum in V1 is equal to two in + + align:start position:0% +2 one Quantum in V1 is equal to two in + + + align:start position:0% +2 one Quantum in V1 is equal to two in +in mode one Quantum in mode one is equal + + align:start position:0% +in mode one Quantum in mode one is equal + + + align:start position:0% +in mode one Quantum in mode one is equal +to to two in mode two so we get we + + align:start position:0% +to to two in mode two so we get we + + + align:start position:0% +to to two in mode two so we get we +multiply the number Quantum mode one by + + align:start position:0% +multiply the number Quantum mode one by + + + align:start position:0% +multiply the number Quantum mode one by +two you get two points for each Quantum + + align:start position:0% +two you get two points for each Quantum + + + align:start position:0% +two you get two points for each Quantum +in mode one and one point for each + + align:start position:0% +in mode one and one point for each + + + align:start position:0% +in mode one and one point for each +Quantum mode two and so we have this and + + align:start position:0% +Quantum mode two and so we have this and + + + align:start position:0% +Quantum mode two and so we have this and +so uh we make a little table of + + align:start position:0% +so uh we make a little table of + + + align:start position:0% +so uh we make a little table of +uh the states that we're going to + + align:start position:0% +uh the states that we're going to + + + align:start position:0% +uh the states that we're going to +encounter and so if we have zero n then + + align:start position:0% +encounter and so if we have zero n then + + + align:start position:0% +encounter and so if we have zero n then +that's the0 0 state if we have one + + align:start position:0% +that's the0 0 state if we have one + + + align:start position:0% +that's the0 0 state if we have one +that's the 01 state if we have two + + align:start position:0% +that's the 01 state if we have two + + + align:start position:0% +that's the 01 state if we have two +that's the uh one zero state but it's + + align:start position:0% +that's the uh one zero state but it's + + + align:start position:0% +that's the uh one zero state but it's +also the 02 state so here's in a case + + align:start position:0% +also the 02 state so here's in a case + + + align:start position:0% +also the 02 state so here's in a case +where that fundamental is near + + align:start position:0% +where that fundamental is near + + + align:start position:0% +where that fundamental is near +degenerate with something else and so + + align:start position:0% +degenerate with something else and so + + + align:start position:0% +degenerate with something else and so +that if you were looking for this + + align:start position:0% +that if you were looking for this + + + align:start position:0% +that if you were looking for this +fundamental uh and you saw something + + align:start position:0% +fundamental uh and you saw something + + + align:start position:0% +fundamental uh and you saw something +that you wanted to assign as the uh this + + align:start position:0% +that you wanted to assign as the uh this + + + align:start position:0% +that you wanted to assign as the uh this +fundamental it will have some effect + + align:start position:0% +fundamental it will have some effect + + + align:start position:0% +fundamental it will have some effect +being perturbed by this and often when + + align:start position:0% +being perturbed by this and often when + + + align:start position:0% +being perturbed by this and often when +you have these anharmonic resonances + + align:start position:0% +you have these anharmonic resonances + + + align:start position:0% +you have these anharmonic resonances +that are near degenerate you get too + + align:start position:0% +that are near degenerate you get too + + + align:start position:0% +that are near degenerate you get too +many candidates for the 3 nus 6 normal + + align:start position:0% +many candidates for the 3 nus 6 normal + + + align:start position:0% +many candidates for the 3 nus 6 normal +modes and you know that something is + + align:start position:0% +modes and you know that something is + + + align:start position:0% +modes and you know that something is +wrong so it's one by one 1 by 1 2x two + + align:start position:0% +wrong so it's one by one 1 by 1 2x two + + + align:start position:0% +wrong so it's one by one 1 by 1 2x two +that's called a + + align:start position:0% +that's called a + + + align:start position:0% +that's called a +diad and with three we have one one and + + align:start position:0% +diad and with three we have one one and + + + align:start position:0% +diad and with three we have one one and +uh 03 another diad and then + + align:start position:0% +uh 03 another diad and then + + + align:start position:0% +uh 03 another diad and then +four 2 + + align:start position:0% +four 2 + + + align:start position:0% +four 2 +0 1 2 and + + align:start position:0% +0 1 2 and + + + align:start position:0% +0 1 2 and +04 and if I just I'm picking 10 we could + + align:start position:0% +04 and if I just I'm picking 10 we could + + + align:start position:0% +04 and if I just I'm picking 10 we could +have uh 5 0 all the way down to 010 + + align:start position:0% +have uh 5 0 all the way down to 010 + + + align:start position:0% +have uh 5 0 all the way down to 010 +and there's six of them so diad Triad + + align:start position:0% +and there's six of them so diad Triad + + + align:start position:0% +and there's six of them so diad Triad +sex + + align:start position:0% +sex + + + align:start position:0% +sex +ad uh you can and it as you go up in + + align:start position:0% +ad uh you can and it as you go up in + + + align:start position:0% +ad uh you can and it as you go up in +polyad quantum number you get more and + + align:start position:0% +polyad quantum number you get more and + + + align:start position:0% +polyad quantum number you get more and +more states that are systematically + + align:start position:0% +more states that are systematically + + + align:start position:0% +more states that are systematically +degenerate and then you say oh well we + + align:start position:0% +degenerate and then you say oh well we + + + align:start position:0% +degenerate and then you say oh well we +have cubic couplings or we have two: one + + align:start position:0% +have cubic couplings or we have two: one + + + align:start position:0% +have cubic couplings or we have two: one +couplings and so there ought to be terms + + align:start position:0% +couplings and so there ought to be terms + + + align:start position:0% +couplings and so there ought to be terms +in the hamiltonian that couple this with + + align:start position:0% +in the hamiltonian that couple this with + + + align:start position:0% +in the hamiltonian that couple this with +this and this with that because we're + + align:start position:0% +this and this with that because we're + + + align:start position:0% +this and this with that because we're +taking one Quantum away from here and + + align:start position:0% +taking one Quantum away from here and + + + align:start position:0% +taking one Quantum away from here and +putting qu in there and each of the off + + align:start position:0% +putting qu in there and each of the off + + + align:start position:0% +putting qu in there and each of the off +diagonal coupling terms will allow you + + align:start position:0% +diagonal coupling terms will allow you + + + align:start position:0% +diagonal coupling terms will allow you +to take one step you can't go from here + + align:start position:0% +to take one step you can't go from here + + + align:start position:0% +to take one step you can't go from here +to here because that would take two + + align:start position:0% +to here because that would take two + + + align:start position:0% +to here because that would take two +Quant away from here and add four to + + align:start position:0% +Quant away from here and add four to + + + align:start position:0% +Quant away from here and add four to +that so you have to do that in two steps + + align:start position:0% +that so you have to do that in two steps + + + align:start position:0% +that so you have to do that in two steps +so as soon as you think that there is + + align:start position:0% +so as soon as you think that there is + + + align:start position:0% +so as soon as you think that there is +some kind of systematic degeneracy you + + align:start position:0% +some kind of systematic degeneracy you + + + align:start position:0% +some kind of systematic degeneracy you +make a table like this and you discover + + align:start position:0% +make a table like this and you discover + + + align:start position:0% +make a table like this and you discover +that there is a uh a pattern like that + + align:start position:0% +that there is a uh a pattern like that + + + align:start position:0% +that there is a uh a pattern like that +and uh if it's a 2:1 resonance then you + + align:start position:0% +and uh if it's a 2:1 resonance then you + + + align:start position:0% +and uh if it's a 2:1 resonance then you +know you're going to be looking for + + align:start position:0% +know you're going to be looking for + + + align:start position:0% +know you're going to be looking for +terms of this + + align:start position:0% + + + + align:start position:0% + +form and uh but as soon as you express + + align:start position:0% +form and uh but as soon as you express + + + align:start position:0% +form and uh but as soon as you express +it in terms of creation Annihilation + + align:start position:0% +it in terms of creation Annihilation + + + align:start position:0% +it in terms of creation Annihilation +operators and you say okay we have a two + + align:start position:0% +operators and you say okay we have a two + + + align:start position:0% +operators and you say okay we have a two +Z and we're going to a one two + + align:start position:0% +Z and we're going to a one two + + + align:start position:0% +Z and we're going to a one two +then by specifying the two states that + + align:start position:0% +then by specifying the two states that + + + align:start position:0% +then by specifying the two states that +we want to couple we know exactly which + + align:start position:0% +we want to couple we know exactly which + + + align:start position:0% +we want to couple we know exactly which +operator we want we're going to have uh + + align:start position:0% +operator we want we're going to have uh + + + align:start position:0% +operator we want we're going to have uh +A1 dagger A2 squar n + + align:start position:0% +A1 dagger A2 squar n + + + align:start position:0% +A1 dagger A2 squar n +dagger so uh you make a list of all of + + align:start position:0% +dagger so uh you make a list of all of + + + align:start position:0% +dagger so uh you make a list of all of +the states that are near togenerate and + + align:start position:0% +the states that are near togenerate and + + + align:start position:0% +the states that are near togenerate and +then uh you discover what is going to be + + align:start position:0% +then uh you discover what is going to be + + + align:start position:0% +then uh you discover what is going to be +the lowest order of term that will + + align:start position:0% +the lowest order of term that will + + + align:start position:0% +the lowest order of term that will +couple all of those States and you know + + align:start position:0% +couple all of those States and you know + + + align:start position:0% +couple all of those States and you know +also how to write the Matrix elements so + + align:start position:0% +also how to write the Matrix elements so + + + align:start position:0% +also how to write the Matrix elements so +this is going to give give a term a + + align:start position:0% +this is going to give give a term a + + + align:start position:0% +this is going to give give a term a +dagger one to two is going to give a + + align:start position:0% +dagger one to two is going to give a + + + align:start position:0% +dagger one to two is going to give a +square of Two and a uh squar on two is + + align:start position:0% +square of Two and a uh squar on two is + + + align:start position:0% +square of Two and a uh squar on two is +going to give 2 * + + align:start position:0% +going to give 2 * + + + align:start position:0% +going to give 2 * +1ot so this is just equal to two so + + align:start position:0% +1ot so this is just equal to two so + + + align:start position:0% +1ot so this is just equal to two so +uh once you organize things in terms of + + align:start position:0% +uh once you organize things in terms of + + + align:start position:0% +uh once you organize things in terms of +near degenerate States it tells you what + + align:start position:0% +near degenerate States it tells you what + + + align:start position:0% +near degenerate States it tells you what +terms are going to be important and it + + align:start position:0% +terms are going to be important and it + + + align:start position:0% +terms are going to be important and it +gives you all of the Matrix elements + + align:start position:0% +gives you all of the Matrix elements + + + align:start position:0% +gives you all of the Matrix elements +among them you + + align:start position:0% +among them you + + + align:start position:0% +among them you +have both selection Rule and Matrix + + align:start position:0% +have both selection Rule and Matrix + + + align:start position:0% +have both selection Rule and Matrix +element + + align:start position:0% +element + + + align:start position:0% +element +scaling it + + align:start position:0% +scaling it + + + align:start position:0% +scaling it +becomes really trivial and this is the + + align:start position:0% +becomes really trivial and this is the + + + align:start position:0% +becomes really trivial and this is the +power of the + + align:start position:0% +power of the + + + align:start position:0% +power of the +technique you don't have to know nothing + + align:start position:0% +technique you don't have to know nothing + + + align:start position:0% +technique you don't have to know nothing +uh and one of the nice things about this + + align:start position:0% +uh and one of the nice things about this + + + align:start position:0% +uh and one of the nice things about this +also is once you've say looked at a + + align:start position:0% +also is once you've say looked at a + + + align:start position:0% +also is once you've say looked at a +diad you have determined all of the + + align:start position:0% +diad you have determined all of the + + + align:start position:0% +diad you have determined all of the +adjustable parameters that will describe + + align:start position:0% +adjustable parameters that will describe + + + align:start position:0% +adjustable parameters that will describe +the energy levels and so yes you can you + + align:start position:0% +the energy levels and so yes you can you + + + align:start position:0% +the energy levels and so yes you can you +can go up to 10 uh The Matrix is Big + + align:start position:0% +can go up to 10 uh The Matrix is Big + + + align:start position:0% +can go up to 10 uh The Matrix is Big +it's a 6x6 instead of a 2X two but you + + align:start position:0% +it's a 6x6 instead of a 2X two but you + + + align:start position:0% +it's a 6x6 instead of a 2X two but you +know all the elements in that Matrix and + + align:start position:0% +know all the elements in that Matrix and + + + align:start position:0% +know all the elements in that Matrix and +so you should be able based on what + + align:start position:0% +so you should be able based on what + + + align:start position:0% +so you should be able based on what +you've already determined up to here you + + align:start position:0% +you've already determined up to here you + + + align:start position:0% +you've already determined up to here you +should be able to extrapolate because + + align:start position:0% +should be able to extrapolate because + + + align:start position:0% +should be able to extrapolate because +you DET the value of + + align:start position:0% +you DET the value of + + + align:start position:0% +you DET the value of +K22 yes yeah and now of course nothing + + align:start position:0% +K22 yes yeah and now of course nothing + + + align:start position:0% +K22 yes yeah and now of course nothing +is perfect but uh uh usually the + + align:start position:0% +is perfect but uh uh usually the + + + align:start position:0% +is perfect but uh uh usually the +breakdown of an extrapolation tells you + + align:start position:0% +breakdown of an extrapolation tells you + + + align:start position:0% +breakdown of an extrapolation tells you +you've neglected some other coupling + + align:start position:0% +you've neglected some other coupling + + + align:start position:0% +you've neglected some other coupling +term and then you know that you have to + + align:start position:0% +term and then you know that you have to + + + align:start position:0% +term and then you know that you have to +look for some other coupling term and + + align:start position:0% +look for some other coupling term and + + + align:start position:0% +look for some other coupling term and +where it's important from the pattern of + + align:start position:0% +where it's important from the pattern of + + + align:start position:0% +where it's important from the pattern of +the breakdown and so it's it's really a + + align:start position:0% +the breakdown and so it's it's really a + + + align:start position:0% +the breakdown and so it's it's really a +an amazingly powerful tool + + align:start position:0% + + + + align:start position:0% + +now of course it's totally + + align:start position:0% + + + + align:start position:0% + +nonsensical because the modes the normal + + align:start position:0% +nonsensical because the modes the normal + + + align:start position:0% +nonsensical because the modes the normal +coordinates or or the individual normal + + align:start position:0% +coordinates or or the individual normal + + + align:start position:0% +coordinates or or the individual normal +modes are not harmonic there are + + align:start position:0% +modes are not harmonic there are + + + align:start position:0% +modes are not harmonic there are +diagonal anharmonicities + + align:start position:0% +diagonal anharmonicities + + + align:start position:0% +diagonal anharmonicities +and so uh it is a lie or it is an + + align:start position:0% +and so uh it is a lie or it is an + + + align:start position:0% +and so uh it is a lie or it is an +inaccuracy to represent the + + align:start position:0% +inaccuracy to represent the + + + align:start position:0% +inaccuracy to represent the +problem uh by putting + + align:start position:0% +problem uh by putting + + + align:start position:0% +problem uh by putting +in uh uh on the diagonal saying the + + align:start position:0% +in uh uh on the diagonal saying the + + + align:start position:0% +in uh uh on the diagonal saying the +energy is Omega time V + a half + x * V + + align:start position:0% +energy is Omega time V + a half + x * V + + + align:start position:0% +energy is Omega time V + a half + x * V ++ a half 2ar and y + V + a half cubed + + align:start position:0% ++ a half 2ar and y + V + a half cubed + + + align:start position:0% ++ a half 2ar and y + V + a half cubed +whatever you + + align:start position:0% +whatever you + + + align:start position:0% +whatever you +need it's a lie because you're only + + align:start position:0% +need it's a lie because you're only + + + align:start position:0% +need it's a lie because you're only +allowed in the harmonic limit to do this + + align:start position:0% +allowed in the harmonic limit to do this + + + align:start position:0% +allowed in the harmonic limit to do this +but we put these things on the + + align:start position:0% +but we put these things on the + + + align:start position:0% +but we put these things on the +diagonal and so they are not harmonic + + align:start position:0% +diagonal and so they are not harmonic + + + align:start position:0% +diagonal and so they are not harmonic +oscillators they're anharmonic + + align:start position:0% +oscillators they're anharmonic + + + align:start position:0% +oscillators they're anharmonic +oscillators and the correct application + + align:start position:0% +oscillators and the correct application + + + align:start position:0% +oscillators and the correct application +of perturbation theory is to then + + align:start position:0% +of perturbation theory is to then + + + align:start position:0% +of perturbation theory is to then +calculate Matrix elements of the + + align:start position:0% +calculate Matrix elements of the + + + align:start position:0% +calculate Matrix elements of the +anharmonic oscillators and that's never + + align:start position:0% +anharmonic oscillators and that's never + + + align:start position:0% +anharmonic oscillators and that's never +done and we can get away with that for a + + align:start position:0% +done and we can get away with that for a + + + align:start position:0% +done and we can get away with that for a +long time but that's the reason why this + + align:start position:0% +long time but that's the reason why this + + + align:start position:0% +long time but that's the reason why this +paper was written uh trying to say okay + + align:start position:0% +paper was written uh trying to say okay + + + align:start position:0% +paper was written uh trying to say okay +well this is a wonderful approximation + + align:start position:0% +well this is a wonderful approximation + + + align:start position:0% +well this is a wonderful approximation +but uh it has to + + align:start position:0% +but uh it has to + + + align:start position:0% +but uh it has to +break okay so but let's just say that we + + align:start position:0% +break okay so but let's just say that we + + + align:start position:0% +break okay so but let's just say that we +have a way of representing all the + + align:start position:0% +have a way of representing all the + + + align:start position:0% +have a way of representing all the +energy levels using models based on one + + align:start position:0% +energy levels using models based on one + + + align:start position:0% +energy levels using models based on one +or two a small number of anharmonic + + align:start position:0% +or two a small number of anharmonic + + + align:start position:0% +or two a small number of anharmonic +coupling terms and we have this + + align:start position:0% +coupling terms and we have this + + + align:start position:0% +coupling terms and we have this +incredible + + align:start position:0% +incredible + + + align:start position:0% +incredible +scaling uh then one of the things we can + + align:start position:0% +scaling uh then one of the things we can + + + align:start position:0% +scaling uh then one of the things we can +do is we can understand inmolecular + + align:start position:0% +do is we can understand inmolecular + + + align:start position:0% +do is we can understand inmolecular +vibrational + + align:start position:0% +vibrational + + + align:start position:0% +vibrational +redistribution now when I came into this + + align:start position:0% +redistribution now when I came into this + + + align:start position:0% +redistribution now when I came into this +game the words + + align:start position:0% +game the words + + + align:start position:0% +game the words +ivr nobody really knew what they stood + + align:start position:0% +ivr nobody really knew what they stood + + + align:start position:0% +ivr nobody really knew what they stood +for because nobody knew what ivr was it + + align:start position:0% +for because nobody knew what ivr was it + + + align:start position:0% +for because nobody knew what ivr was it +was basically you know at high exitation + + align:start position:0% +was basically you know at high exitation + + + align:start position:0% +was basically you know at high exitation +there's strong coupling between modes + + align:start position:0% +there's strong coupling between modes + + + align:start position:0% +there's strong coupling between modes +and you get an evolution towards + + align:start position:0% +and you get an evolution towards + + + align:start position:0% +and you get an evolution towards +chaos and and so uh is this + + align:start position:0% +chaos and and so uh is this + + + align:start position:0% +chaos and and so uh is this +redistribution or randomization + + align:start position:0% +redistribution or randomization + + + align:start position:0% +redistribution or randomization +randomization implies chaos + + align:start position:0% +randomization implies chaos + + + align:start position:0% +randomization implies chaos +redistribution implies a mechanism + + align:start position:0% +redistribution implies a mechanism + + + align:start position:0% +redistribution implies a mechanism +uh and this is inmolecular vibration so + + align:start position:0% +uh and this is inmolecular vibration so + + + align:start position:0% +uh and this is inmolecular vibration so +uh ivr was basically one of these uh + + align:start position:0% +uh ivr was basically one of these uh + + + align:start position:0% +uh ivr was basically one of these uh +non-radiative processes that occur in + + align:start position:0% +non-radiative processes that occur in + + + align:start position:0% +non-radiative processes that occur in +molecules where people had taken a + + align:start position:0% +molecules where people had taken a + + + align:start position:0% +molecules where people had taken a +phenomenological mostly + + align:start position:0% +phenomenological mostly + + + align:start position:0% +phenomenological mostly +statistical uh picture of it that there + + align:start position:0% +statistical uh picture of it that there + + + align:start position:0% +statistical uh picture of it that there +was not enough uh information to + + align:start position:0% +was not enough uh information to + + + align:start position:0% +was not enough uh information to +describe it but if we have a polyad + + align:start position:0% +describe it but if we have a polyad + + + align:start position:0% +describe it but if we have a polyad +model then we can always write the ual + + align:start position:0% +model then we can always write the ual + + + align:start position:0% +model then we can always write the ual +Ian States as some linear combination of + + align:start position:0% +Ian States as some linear combination of + + + align:start position:0% +Ian States as some linear combination of +uh zero order States and I'm sorry about + + align:start position:0% +uh zero order States and I'm sorry about + + + align:start position:0% +uh zero order States and I'm sorry about +this + + align:start position:0% +this + + + align:start position:0% +this +notation and we can imagine doing some + + align:start position:0% +notation and we can imagine doing some + + + align:start position:0% +notation and we can imagine doing some +short puls exitation where we prepare a + + align:start position:0% +short puls exitation where we prepare a + + + align:start position:0% +short puls exitation where we prepare a +system at T equals z with a short pulse + + align:start position:0% +system at T equals z with a short pulse + + + align:start position:0% +system at T equals z with a short pulse +and we prepare it not in one igen state + + align:start position:0% +and we prepare it not in one igen state + + + align:start position:0% +and we prepare it not in one igen state +but in a + + align:start position:0% +but in a + + + align:start position:0% +but in a +state a zero order + + align:start position:0% +state a zero order + + + align:start position:0% +state a zero order +State because the the zero order states + + align:start position:0% +State because the the zero order states + + + align:start position:0% +State because the the zero order states +are the are the things that uh uh often + + align:start position:0% +are the are the things that uh uh often + + + align:start position:0% +are the are the things that uh uh often +get picked out by exitation by a + + align:start position:0% +get picked out by exitation by a + + + align:start position:0% +get picked out by exitation by a +photon we'll talk about that more + + align:start position:0% +photon we'll talk about that more + + + align:start position:0% +photon we'll talk about that more +probably uh although how much time do I + + align:start position:0% +probably uh although how much time do I + + + align:start position:0% +probably uh although how much time do I +have not not a lot okay so uh in order + + align:start position:0% +have not not a lot okay so uh in order + + + align:start position:0% +have not not a lot okay so uh in order +to + + align:start position:0% +to + + + align:start position:0% +to +describe s of + + align:start position:0% +describe s of + + + align:start position:0% +describe s of +T you have to reexpress this zero order + + align:start position:0% +T you have to reexpress this zero order + + + align:start position:0% +T you have to reexpress this zero order +State as a sum over ion state it's doing + + align:start position:0% +State as a sum over ion state it's doing + + + align:start position:0% +State as a sum over ion state it's doing +this transformation backwards and so we + + align:start position:0% +this transformation backwards and so we + + + align:start position:0% +this transformation backwards and so we +have b j e to Theus e i t h + + align:start position:0% +have b j e to Theus e i t h + + + align:start position:0% +have b j e to Theus e i t h +bar I so this is an expansion in terms + + align:start position:0% +bar I so this is an expansion in terms + + + align:start position:0% +bar I so this is an expansion in terms +of IG States and this is the time + + align:start position:0% +of IG States and this is the time + + + align:start position:0% +of IG States and this is the time +dependence so it's a superposition of I + + align:start position:0% +dependence so it's a superposition of I + + + align:start position:0% +dependence so it's a superposition of I +States and these two terms come from the + + align:start position:0% +States and these two terms come from the + + + align:start position:0% +States and these two terms come from the +unitary transformation that takes you + + align:start position:0% +unitary transformation that takes you + + + align:start position:0% +unitary transformation that takes you +between the order and the Ian state + + align:start position:0% +between the order and the Ian state + + + align:start position:0% +between the order and the Ian state +representation and it's just a matter of + + align:start position:0% +representation and it's just a matter of + + + align:start position:0% +representation and it's just a matter of +which way you're + + align:start position:0% +which way you're + + + align:start position:0% +which way you're +going okay so we know these things + + align:start position:0% +going okay so we know these things + + + align:start position:0% +going okay so we know these things +because we did diagonalize The Matrix + + align:start position:0% +because we did diagonalize The Matrix + + + align:start position:0% +because we did diagonalize The Matrix +and so if we know by the nature of what + + align:start position:0% +and so if we know by the nature of what + + + align:start position:0% +and so if we know by the nature of what +the molecule is and what the process is + + align:start position:0% +the molecule is and what the process is + + + align:start position:0% +the molecule is and what the process is +for getting into this energy region what + + align:start position:0% +for getting into this energy region what + + + align:start position:0% +for getting into this energy region what +is the bright State then we can always + + align:start position:0% +is the bright State then we can always + + + align:start position:0% +is the bright State then we can always +say okay the time evolving + + align:start position:0% +say okay the time evolving + + + align:start position:0% +say okay the time evolving +State uh well uh we can always write the + + align:start position:0% +State uh well uh we can always write the + + + align:start position:0% +State uh well uh we can always write the +time evolving State as a superposition + + align:start position:0% +time evolving State as a superposition + + + align:start position:0% +time evolving State as a superposition +but one of the members of the + + align:start position:0% +but one of the members of the + + + align:start position:0% +but one of the members of the +superposition is going to I'm + + align:start position:0% +superposition is going to I'm + + + align:start position:0% +superposition is going to I'm +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +backup uh one of the + + align:start position:0% +backup uh one of the + + + align:start position:0% +backup uh one of the +um one of the zero order States is + + align:start position:0% +um one of the zero order States is + + + align:start position:0% +um one of the zero order States is +usually the bright State and + + align:start position:0% +usually the bright State and + + + align:start position:0% +usually the bright State and +there there are two classes of + + align:start position:0% +there there are two classes of + + + align:start position:0% +there there are two classes of +experiment that prepare highly excited + + align:start position:0% +experiment that prepare highly excited + + + align:start position:0% +experiment that prepare highly excited +molecules one is called High + + align:start position:0% + + + + align:start position:0% + +overtone + + align:start position:0% + + + + align:start position:0% + +pumping and the other is called + + align:start position:0% +pumping and the other is called + + + align:start position:0% +pumping and the other is called +stimulated emission + + align:start position:0% +stimulated emission + + + align:start position:0% +stimulated emission +pumping High overtone pumping was very + + align:start position:0% +pumping High overtone pumping was very + + + align:start position:0% +pumping High overtone pumping was very +popular uh in the + + align:start position:0% +popular uh in the + + + align:start position:0% +popular uh in the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh late + + align:start position:0% +uh late + + + align:start position:0% +uh late +70s uh because people started to have + + align:start position:0% +70s uh because people started to have + + + align:start position:0% +70s uh because people started to have +tunable lasers and started to have + + align:start position:0% +tunable lasers and started to have + + + align:start position:0% +tunable lasers and started to have +sufficient ability with the lasers they + + align:start position:0% +sufficient ability with the lasers they + + + align:start position:0% +sufficient ability with the lasers they +could look at Spectra at fairly High + + align:start position:0% +could look at Spectra at fairly High + + + align:start position:0% +could look at Spectra at fairly High +sensitivity and so they were putting all + + align:start position:0% +sensitivity and so they were putting all + + + align:start position:0% +sensitivity and so they were putting all +sorts of gases into their apparatus and + + align:start position:0% +sorts of gases into their apparatus and + + + align:start position:0% +sorts of gases into their apparatus and +they observed vibrational transitions in + + align:start position:0% +they observed vibrational transitions in + + + align:start position:0% +they observed vibrational transitions in +the + + align:start position:0% +the + + + align:start position:0% +the +visible and we know vibrational + + align:start position:0% +visible and we know vibrational + + + align:start position:0% +visible and we know vibrational +transitions are going to be in the + + align:start position:0% +transitions are going to be in the + + + align:start position:0% +transitions are going to be in the +infrared but they observed instead of + + align:start position:0% +infrared but they observed instead of + + + align:start position:0% +infrared but they observed instead of +something really complicated they + + align:start position:0% +something really complicated they + + + align:start position:0% +something really complicated they +observed something really simple they + + align:start position:0% +observed something really simple they + + + align:start position:0% +observed something really simple they +observed a progression of RH stretch + + align:start position:0% +observed a progression of RH stretch + + + align:start position:0% +observed a progression of RH stretch +vibrations as and it didn't matter how + + align:start position:0% +vibrations as and it didn't matter how + + + align:start position:0% +vibrations as and it didn't matter how +complicated the molecule was you had a + + align:start position:0% +complicated the molecule was you had a + + + align:start position:0% +complicated the molecule was you had a +nice slightly anharmonic progression of + + align:start position:0% +nice slightly anharmonic progression of + + + align:start position:0% +nice slightly anharmonic progression of +transitions uh and usually uh the lasers + + align:start position:0% +transitions uh and usually uh the lasers + + + align:start position:0% +transitions uh and usually uh the lasers +started around uh um say 12,000 wave + + align:start position:0% +started around uh um say 12,000 wave + + + align:start position:0% +started around uh um say 12,000 wave +numbers which is 4 * + + align:start position:0% +numbers which is 4 * + + + align:start position:0% +numbers which is 4 * +3,000 and R8 stretches are 3,000 wave + + align:start position:0% +3,000 and R8 stretches are 3,000 wave + + + align:start position:0% +3,000 and R8 stretches are 3,000 wave +numbers and so you often had four five + + align:start position:0% +numbers and so you often had four five + + + align:start position:0% +numbers and so you often had four five +six maybe seven depending if you could + + align:start position:0% +six maybe seven depending if you could + + + align:start position:0% +six maybe seven depending if you could +go the lasers were + + align:start position:0% +go the lasers were + + + align:start position:0% +go the lasers were +sufficiently uh blue uh so you might see + + align:start position:0% +sufficiently uh blue uh so you might see + + + align:start position:0% +sufficiently uh blue uh so you might see +several members of this progression and + + align:start position:0% +several members of this progression and + + + align:start position:0% +several members of this progression and +it was very well behaved and uh uh there + + align:start position:0% +it was very well behaved and uh uh there + + + align:start position:0% +it was very well behaved and uh uh there +was a lot of interest in + + align:start position:0% +was a lot of interest in + + + align:start position:0% +was a lot of interest in +ivr uh on the overtones and so what one + + align:start position:0% +ivr uh on the overtones and so what one + + + align:start position:0% +ivr uh on the overtones and so what one +measured was how broad were these things + + align:start position:0% +measured was how broad were these things + + + align:start position:0% +measured was how broad were these things +and the width was somehow related to + + align:start position:0% +and the width was somehow related to + + + align:start position:0% +and the width was somehow related to +some ivr rate and there were a lot of + + align:start position:0% +some ivr rate and there were a lot of + + + align:start position:0% +some ivr rate and there were a lot of +theories uh what determined these widths + + align:start position:0% +theories uh what determined these widths + + + align:start position:0% +theories uh what determined these widths +now these are not homogeneous widths the + + align:start position:0% +now these are not homogeneous widths the + + + align:start position:0% +now these are not homogeneous widths the +they often at higher resolution you + + align:start position:0% +they often at higher resolution you + + + align:start position:0% +they often at higher resolution you +started to see some structure under + + align:start position:0% +started to see some structure under + + + align:start position:0% +started to see some structure under +these uh they couldn't be homogeneous + + align:start position:0% +these uh they couldn't be homogeneous + + + align:start position:0% +these uh they couldn't be homogeneous +widths but in a molecule like Benzene + + align:start position:0% +widths but in a molecule like Benzene + + + align:start position:0% +widths but in a molecule like Benzene +the density of states is so high that it + + align:start position:0% +the density of states is so high that it + + + align:start position:0% +the density of states is so high that it +would be impossible to resolve but in a + + align:start position:0% +would be impossible to resolve but in a + + + align:start position:0% +would be impossible to resolve but in a +molecule uh like from Malahide or uh uh + + align:start position:0% +molecule uh like from Malahide or uh uh + + + align:start position:0% +molecule uh like from Malahide or uh uh +methyl fluoride or something like that + + align:start position:0% +methyl fluoride or something like that + + + align:start position:0% +methyl fluoride or something like that +you could resolve the lines and there + + align:start position:0% +you could resolve the lines and there + + + align:start position:0% +you could resolve the lines and there +was interesting structure so even in the + + align:start position:0% +was interesting structure so even in the + + + align:start position:0% +was interesting structure so even in the +1970s yeah even oh + + align:start position:0% +1970s yeah even oh + + + align:start position:0% +1970s yeah even oh +sure uh so there was a lot of stuff and + + align:start position:0% +sure uh so there was a lot of stuff and + + + align:start position:0% +sure uh so there was a lot of stuff and +a lot of really stupid stuff said about + + align:start position:0% +a lot of really stupid stuff said about + + + align:start position:0% +a lot of really stupid stuff said about +them and uh um but the possibility of + + align:start position:0% +them and uh um but the possibility of + + + align:start position:0% +them and uh um but the possibility of +looking at high vibrational Levels by + + align:start position:0% +looking at high vibrational Levels by + + + align:start position:0% +looking at high vibrational Levels by +overtones uh stimulated an awful lot of + + align:start position:0% +overtones uh stimulated an awful lot of + + + align:start position:0% +overtones uh stimulated an awful lot of +belief that you could put a lot of + + align:start position:0% +belief that you could put a lot of + + + align:start position:0% +belief that you could put a lot of +exitation in one + + align:start position:0% +exitation in one + + + align:start position:0% +exitation in one +Bond uh because it was clear that these + + align:start position:0% +Bond uh because it was clear that these + + + align:start position:0% +Bond uh because it was clear that these +were local excitations and so it was + + align:start position:0% +were local excitations and so it was + + + align:start position:0% +were local excitations and so it was +clear that you know you could make + + align:start position:0% +clear that you know you could make + + + align:start position:0% +clear that you know you could make +Benzene with 16 six Quant of exitation + + align:start position:0% +Benzene with 16 six Quant of exitation + + + align:start position:0% +Benzene with 16 six Quant of exitation +on in an R8 stretch and this width was + + align:start position:0% +on in an R8 stretch and this width was + + + align:start position:0% +on in an R8 stretch and this width was +somehow telling you how long it would + + align:start position:0% +somehow telling you how long it would + + + align:start position:0% +somehow telling you how long it would +stay there and there are people in fact + + align:start position:0% +stay there and there are people in fact + + + align:start position:0% +stay there and there are people in fact +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um Mike Barry at Allied chemical uh + + align:start position:0% +um Mike Barry at Allied chemical uh + + + align:start position:0% +um Mike Barry at Allied chemical uh +built up a big division promising to do + + align:start position:0% +built up a big division promising to do + + + align:start position:0% +built up a big division promising to do +Bond specific + + align:start position:0% +Bond specific + + + align:start position:0% +Bond specific +chemistry based on the appearance of + + align:start position:0% +chemistry based on the appearance of + + + align:start position:0% +chemistry based on the appearance of +these local modes I mean we're chemists + + align:start position:0% +these local modes I mean we're chemists + + + align:start position:0% +these local modes I mean we're chemists +we we believe in bonds and here + + align:start position:0% +we we believe in bonds and here + + + align:start position:0% +we we believe in bonds and here +something in the spectrum that looks + + align:start position:0% +something in the spectrum that looks + + + align:start position:0% +something in the spectrum that looks +like a bond a selective exitation of a + + align:start position:0% +like a bond a selective exitation of a + + + align:start position:0% +like a bond a selective exitation of a +bond and so here was this dream that you + + align:start position:0% +bond and so here was this dream that you + + + align:start position:0% +bond and so here was this dream that you +could you could excite to a specific put + + align:start position:0% +could you could excite to a specific put + + + align:start position:0% +could you could excite to a specific put +all the energy into a specific Bond and + + align:start position:0% +all the energy into a specific Bond and + + + align:start position:0% +all the energy into a specific Bond and +and then do chemistry on that Bond and + + align:start position:0% +and then do chemistry on that Bond and + + + align:start position:0% +and then do chemistry on that Bond and +that that was sold very hard by Mike + + align:start position:0% +that that was sold very hard by Mike + + + align:start position:0% +that that was sold very hard by Mike +Barry and some several other people okay + + align:start position:0% +Barry and some several other people okay + + + align:start position:0% +Barry and some several other people okay +it turned out to be impossible + + align:start position:0% +it turned out to be impossible + + + align:start position:0% +it turned out to be impossible +uh and stimulator emission pumping was + + align:start position:0% +uh and stimulator emission pumping was + + + align:start position:0% +uh and stimulator emission pumping was +invented by me and this was was a + + align:start position:0% +invented by me and this was was a + + + align:start position:0% +invented by me and this was was a +different class this gave access to a + + align:start position:0% +different class this gave access to a + + + align:start position:0% +different class this gave access to a +different class of Highly vibrationally + + align:start position:0% +different class of Highly vibrationally + + + align:start position:0% +different class of Highly vibrationally +excited + + align:start position:0% +excited + + + align:start position:0% +excited +state the local modes were uh present in + + align:start position:0% +state the local modes were uh present in + + + align:start position:0% +state the local modes were uh present in +the spectrum + + align:start position:0% +the spectrum + + + align:start position:0% +the spectrum +because um the RH stretches were most + + align:start position:0% +because um the RH stretches were most + + + align:start position:0% +because um the RH stretches were most +anharmonic and highest frequency and so + + align:start position:0% +anharmonic and highest frequency and so + + + align:start position:0% +anharmonic and highest frequency and so +in any given energy region a state a + + align:start position:0% +in any given energy region a state a + + + align:start position:0% +in any given energy region a state a +zero order state that has the most Quant + + align:start position:0% +zero order state that has the most Quant + + + align:start position:0% +zero order state that has the most Quant +in this lowest this highest frequency + + align:start position:0% +in this lowest this highest frequency + + + align:start position:0% +in this lowest this highest frequency +mode uh well that that will have the + + align:start position:0% +mode uh well that that will have the + + + align:start position:0% +mode uh well that that will have the +strongest uh the strongest uh uh + + align:start position:0% +strongest uh the strongest uh uh + + + align:start position:0% +strongest uh the strongest uh uh +transition and so because of the + + align:start position:0% +transition and so because of the + + + align:start position:0% +transition and so because of the +anharmonicity and because the fewer + + align:start position:0% +anharmonicity and because the fewer + + + align:start position:0% +anharmonicity and because the fewer +Quant each the rule of thumb is each + + align:start position:0% +Quant each the rule of thumb is each + + + align:start position:0% +Quant each the rule of thumb is each +successive harmonic cost you about a + + align:start position:0% +successive harmonic cost you about a + + + align:start position:0% +successive harmonic cost you about a +factor of 100 in intensity so if you + + align:start position:0% +factor of 100 in intensity so if you + + + align:start position:0% +factor of 100 in intensity so if you +have some states with eight quana in one + + align:start position:0% +have some states with eight quana in one + + + align:start position:0% +have some states with eight quana in one +lower frequency mode degenerate with + + align:start position:0% +lower frequency mode degenerate with + + + align:start position:0% +lower frequency mode degenerate with +states of six quana you would expect + + align:start position:0% +states of six quana you would expect + + + align:start position:0% +states of six quana you would expect +that all things being equal they're + + align:start position:0% +that all things being equal they're + + + align:start position:0% +that all things being equal they're +going to be 10,000 times weak + + align:start position:0% +going to be 10,000 times weak + + + align:start position:0% +going to be 10,000 times weak +transitions at those levels will be + + align:start position:0% +transitions at those levels will be + + + align:start position:0% +transitions at those levels will be +10,000 times weaker and that's true and + + align:start position:0% +10,000 times weaker and that's true and + + + align:start position:0% +10,000 times weaker and that's true and +so what happened in the overtones is + + align:start position:0% +so what happened in the overtones is + + + align:start position:0% +so what happened in the overtones is +that you had one bright State one class + + align:start position:0% +that you had one bright State one class + + + align:start position:0% +that you had one bright State one class +of bright state only one it plucks the + + align:start position:0% +of bright state only one it plucks the + + + align:start position:0% +of bright state only one it plucks the +system in a way which is relatively + + align:start position:0% +system in a way which is relatively + + + align:start position:0% +system in a way which is relatively +special and relatively uh uncoupled from + + align:start position:0% +special and relatively uh uncoupled from + + + align:start position:0% +special and relatively uh uncoupled from +chaos cuz how you know by stretching a + + align:start position:0% +chaos cuz how you know by stretching a + + + align:start position:0% +chaos cuz how you know by stretching a +bond uh uh it takes a while for the + + align:start position:0% +bond uh uh it takes a while for the + + + align:start position:0% +bond uh uh it takes a while for the +energy to leave that + + align:start position:0% +energy to leave that + + + align:start position:0% +energy to leave that +Bond and so it it's uh not a democratic + + align:start position:0% +Bond and so it it's uh not a democratic + + + align:start position:0% +Bond and so it it's uh not a democratic +sample of what's going on in the uh + + align:start position:0% +sample of what's going on in the uh + + + align:start position:0% +sample of what's going on in the uh +vibrational + + align:start position:0% +vibrational + + + align:start position:0% +vibrational +manifold uh and uh and so people were + + align:start position:0% +manifold uh and uh and so people were + + + align:start position:0% +manifold uh and uh and so people were +anxious to have some other way of + + align:start position:0% +anxious to have some other way of + + + align:start position:0% +anxious to have some other way of +starting out the Dynamics some other + + align:start position:0% +starting out the Dynamics some other + + + align:start position:0% +starting out the Dynamics some other +class of zero order bright State + + align:start position:0% +class of zero order bright State + + + align:start position:0% +class of zero order bright State +stimulated emission + + align:start position:0% +stimulated emission + + + align:start position:0% +stimulated emission +pumping was we go from the ground state + + align:start position:0% +pumping was we go from the ground state + + + align:start position:0% +pumping was we go from the ground state +to an electronically excited state and + + align:start position:0% +to an electronically excited state and + + + align:start position:0% +to an electronically excited state and +then back to high vibrational levels of + + align:start position:0% +then back to high vibrational levels of + + + align:start position:0% +then back to high vibrational levels of +the ground state and that's driven not + + align:start position:0% +the ground state and that's driven not + + + align:start position:0% +the ground state and that's driven not +by infrared selection rules or VI + + align:start position:0% +by infrared selection rules or VI + + + align:start position:0% +by infrared selection rules or VI +vibrational selection rules but by Frank + + align:start position:0% +vibrational selection rules but by Frank + + + align:start position:0% +vibrational selection rules but by Frank +Condon factors and so if you used an + + align:start position:0% +Condon factors and so if you used an + + + align:start position:0% +Condon factors and so if you used an +electronically excited state with + + align:start position:0% +electronically excited state with + + + align:start position:0% +electronically excited state with +geometry very different from the ground + + align:start position:0% +geometry very different from the ground + + + align:start position:0% +geometry very different from the ground +state then one can get access to high + + align:start position:0% +state then one can get access to high + + + align:start position:0% +state then one can get access to high +vibrational levels of the ground state + + align:start position:0% +vibrational levels of the ground state + + + align:start position:0% +vibrational levels of the ground state +that uh our frankc and + + align:start position:0% +that uh our frankc and + + + align:start position:0% +that uh our frankc and +selected and so this profoundly changed + + align:start position:0% +selected and so this profoundly changed + + + align:start position:0% +selected and so this profoundly changed +the name of the game because now it's + + align:start position:0% +the name of the game because now it's + + + align:start position:0% +the name of the game because now it's +not just one other class of bright state + + align:start position:0% +not just one other class of bright state + + + align:start position:0% +not just one other class of bright state +but depending on which vibrational level + + align:start position:0% +but depending on which vibrational level + + + align:start position:0% +but depending on which vibrational level +of this state you went to you could get + + align:start position:0% +of this state you went to you could get + + + align:start position:0% +of this state you went to you could get +different bright States and so one could + + align:start position:0% +different bright States and so one could + + + align:start position:0% +different bright States and so one could +start to pick away at the Dynamics and + + align:start position:0% +start to pick away at the Dynamics and + + + align:start position:0% +start to pick away at the Dynamics and +to understand them and so this led to an + + align:start position:0% +to understand them and so this led to an + + + align:start position:0% +to understand them and so this led to an +explosion of uh knowledge and + + align:start position:0% +explosion of uh knowledge and + + + align:start position:0% +explosion of uh knowledge and +experimentation on high vibrational + + align:start position:0% +experimentation on high vibrational + + + align:start position:0% +experimentation on high vibrational +levels because now we had it a much more + + align:start position:0% +levels because now we had it a much more + + + align:start position:0% +levels because now we had it a much more +democratic or at least a much more + + align:start position:0% +democratic or at least a much more + + + align:start position:0% +democratic or at least a much more +systematic view of the uh um the + + align:start position:0% +systematic view of the uh um the + + + align:start position:0% +systematic view of the uh um the +couplings that occur at high + + align:start position:0% + + + + align:start position:0% + +exitation okay I I should stop but I + + align:start position:0% +exitation okay I I should stop but I + + + align:start position:0% +exitation okay I I should stop but I +want to say a couple more things about + + align:start position:0% +want to say a couple more things about + + + align:start position:0% +want to say a couple more things about +uh local + + align:start position:0% + + + + align:start position:0% + +modes so in the early + + align:start position:0% +modes so in the early + + + align:start position:0% +modes so in the early +days uh + + align:start position:0% +days uh + + + align:start position:0% +days uh +one saw experimentally that + + align:start position:0% +one saw experimentally that + + + align:start position:0% +one saw experimentally that +something appeared in the spectrum that + + align:start position:0% +something appeared in the spectrum that + + + align:start position:0% +something appeared in the spectrum that +looked like local RH stretch + + align:start position:0% +looked like local RH stretch + + + align:start position:0% +looked like local RH stretch +overtones and then going to these polyad + + align:start position:0% +overtones and then going to these polyad + + + align:start position:0% +overtones and then going to these polyad +models we discovered that what are the + + align:start position:0% +models we discovered that what are the + + + align:start position:0% +models we discovered that what are the +symptoms of local mode well what you one + + align:start position:0% +symptoms of local mode well what you one + + + align:start position:0% +symptoms of local mode well what you one +of the symptoms is there are almost + + align:start position:0% +of the symptoms is there are almost + + + align:start position:0% +of the symptoms is there are almost +always two + + align:start position:0% +always two + + + align:start position:0% +always two +symmetries I mean if you take two + + align:start position:0% +symmetries I mean if you take two + + + align:start position:0% +symmetries I mean if you take two +identical things and combine them + + align:start position:0% +identical things and combine them + + + align:start position:0% +identical things and combine them +symmetrically and antisymmetrically you + + align:start position:0% +symmetrically and antisymmetrically you + + + align:start position:0% +symmetrically and antisymmetrically you +have two states of different + + align:start position:0% +have two states of different + + + align:start position:0% +have two states of different +Symmetry and because the local modes + + align:start position:0% +Symmetry and because the local modes + + + align:start position:0% +Symmetry and because the local modes +don't know about each + + align:start position:0% +don't know about each + + + align:start position:0% +don't know about each +other they become degenerate and so this + + align:start position:0% +other they become degenerate and so this + + + align:start position:0% +other they become degenerate and so this +uh + + align:start position:0% + + + + align:start position:0% + +degeneracy was the the prime evidence + + align:start position:0% +degeneracy was the the prime evidence + + + align:start position:0% +degeneracy was the the prime evidence +for for the appearance of local + + align:start position:0% +for for the appearance of local + + + align:start position:0% +for for the appearance of local +modes remember when you record a + + align:start position:0% +modes remember when you record a + + + align:start position:0% +modes remember when you record a +spectrum you don't observe the wave + + align:start position:0% +spectrum you don't observe the wave + + + align:start position:0% +spectrum you don't observe the wave +function but when you fit a spectrum to + + align:start position:0% +function but when you fit a spectrum to + + + align:start position:0% +function but when you fit a spectrum to +a model you have igen vectors and you + + align:start position:0% +a model you have igen vectors and you + + + align:start position:0% +a model you have igen vectors and you +can look at what the igen vectors are + + align:start position:0% +can look at what the igen vectors are + + + align:start position:0% +can look at what the igen vectors are +like and you can re write the igen + + align:start position:0% +like and you can re write the igen + + + align:start position:0% +like and you can re write the igen +vectors Express them in terms of the + + align:start position:0% +vectors Express them in terms of the + + + align:start position:0% +vectors Express them in terms of the +internal coordinate displacements and + + align:start position:0% +internal coordinate displacements and + + + align:start position:0% +internal coordinate displacements and +You by examining the igen vectors of the + + align:start position:0% +You by examining the igen vectors of the + + + align:start position:0% +You by examining the igen vectors of the +effect of Hamilton you can see that you + + align:start position:0% +effect of Hamilton you can see that you + + + align:start position:0% +effect of Hamilton you can see that you +do have uh left oscillator and right + + align:start position:0% +do have uh left oscillator and right + + + align:start position:0% +do have uh left oscillator and right +oscillator but the igen states are + + align:start position:0% +oscillator but the igen states are + + + align:start position:0% +oscillator but the igen states are +always symmetric and antisymmetric + + align:start position:0% +always symmetric and antisymmetric + + + align:start position:0% +always symmetric and antisymmetric +combinations and that they're degenerate + + align:start position:0% +combinations and that they're degenerate + + + align:start position:0% +combinations and that they're degenerate +and if you if you took s+ plus SI + + align:start position:0% +and if you if you took s+ plus SI + + + align:start position:0% +and if you if you took s+ plus SI +minus uh where this is just some + + align:start position:0% +minus uh where this is just some + + + align:start position:0% +minus uh where this is just some +symmetric and any symmetric then you get + + align:start position:0% +symmetric and any symmetric then you get + + + align:start position:0% +symmetric and any symmetric then you get +S right and uh uh if you take the minus + + align:start position:0% +S right and uh uh if you take the minus + + + align:start position:0% +S right and uh uh if you take the minus +combination you get S left so the first + + align:start position:0% +combination you get S left so the first + + + align:start position:0% +combination you get S left so the first +thing is the observation of degeneracy + + align:start position:0% +thing is the observation of degeneracy + + + align:start position:0% +thing is the observation of degeneracy +then you look at the igen vectors and + + align:start position:0% +then you look at the igen vectors and + + + align:start position:0% +then you look at the igen vectors and +you see that they really are localized + + align:start position:0% +you see that they really are localized + + + align:start position:0% +you see that they really are localized +but they're not + + align:start position:0% +but they're not + + + align:start position:0% +but they're not +localized uh uh in the sense of one + + align:start position:0% +localized uh uh in the sense of one + + + align:start position:0% +localized uh uh in the sense of one +state because you can't do that you have + + align:start position:0% +state because you can't do that you have + + + align:start position:0% +state because you can't do that you have +left oscillator and right oscillator + + align:start position:0% +left oscillator and right oscillator + + + align:start position:0% +left oscillator and right oscillator +they're equivalent but you make the some + + align:start position:0% +they're equivalent but you make the some + + + align:start position:0% +they're equivalent but you make the some +some indifference terms and then you + + align:start position:0% +some indifference terms and then you + + + align:start position:0% +some indifference terms and then you +take sums IND differences of those you + + align:start position:0% +take sums IND differences of those you + + + align:start position:0% +take sums IND differences of those you +get back to these local mode + + align:start position:0% +get back to these local mode + + + align:start position:0% +get back to these local mode +States um + + align:start position:0% + + + + align:start position:0% + +and the other thing is that the + + align:start position:0% +and the other thing is that the + + + align:start position:0% +and the other thing is that the +intensity + + align:start position:0% + + + + align:start position:0% + +pattern the intensity pattern in the + + align:start position:0% +pattern the intensity pattern in the + + + align:start position:0% +pattern the intensity pattern in the +Spectrum The Disappearance of all but + + align:start position:0% +Spectrum The Disappearance of all but + + + align:start position:0% +Spectrum The Disappearance of all but +one class of state which is recognized + + align:start position:0% +one class of state which is recognized + + + align:start position:0% +one class of state which is recognized +as an overtone of something that looks + + align:start position:0% +as an overtone of something that looks + + + align:start position:0% +as an overtone of something that looks +like an RH stretch because it has a + + align:start position:0% +like an RH stretch because it has a + + + align:start position:0% +like an RH stretch because it has a +frequency on the order of 3,000 wave + + align:start position:0% +frequency on the order of 3,000 wave + + + align:start position:0% +frequency on the order of 3,000 wave +numbers and the different R8 stretches o + + align:start position:0% +numbers and the different R8 stretches o + + + align:start position:0% +numbers and the different R8 stretches o +versus CH they have slightly different + + align:start position:0% +versus CH they have slightly different + + + align:start position:0% +versus CH they have slightly different +frequencies and so uh uh + + align:start position:0% +frequencies and so uh uh + + + align:start position:0% +frequencies and so uh uh +all of this implied the existence of + + align:start position:0% +all of this implied the existence of + + + align:start position:0% +all of this implied the existence of +local + + align:start position:0% +local + + + align:start position:0% +local +modes and uh + + align:start position:0% +modes and uh + + + align:start position:0% +modes and uh +so the the thing that I had hoped to get + + align:start position:0% +so the the thing that I had hoped to get + + + align:start position:0% +so the the thing that I had hoped to get +to today and why I handed out pages from + + align:start position:0% +to today and why I handed out pages from + + + align:start position:0% +to today and why I handed out pages from +the paper was that we can write the + + align:start position:0% +the paper was that we can write the + + + align:start position:0% +the paper was that we can write the +hamiltonian in a normal mode picture or + + align:start position:0% +hamiltonian in a normal mode picture or + + + align:start position:0% +hamiltonian in a normal mode picture or +in a local mode + + align:start position:0% +in a local mode + + + align:start position:0% +in a local mode +picture and + + align:start position:0% +picture and + + + align:start position:0% +picture and +so + + align:start position:0% +so + + + align:start position:0% +so +uh the hamiltonian is expressed in terms + + align:start position:0% +uh the hamiltonian is expressed in terms + + + align:start position:0% +uh the hamiltonian is expressed in terms +of frequencies of modes and and + + align:start position:0% +of frequencies of modes and and + + + align:start position:0% +of frequencies of modes and and +harmonici of modes and coupling terms so + + align:start position:0% +harmonici of modes and coupling terms so + + + align:start position:0% +harmonici of modes and coupling terms so +you have two different + + align:start position:0% +you have two different + + + align:start position:0% +you have two different +models they're really describing the + + align:start position:0% +models they're really describing the + + + align:start position:0% +models they're really describing the +same phenomenon and you have the energy + + align:start position:0% +same phenomenon and you have the energy + + + align:start position:0% +same phenomenon and you have the energy +levels + + align:start position:0% +levels + + + align:start position:0% +levels +so you fit the energy levels + + align:start position:0% +so you fit the energy levels + + + align:start position:0% +so you fit the energy levels +to frequencies and anharmonicities and + + align:start position:0% +to frequencies and anharmonicities and + + + align:start position:0% +to frequencies and anharmonicities and +coupling terms so you have a model where + + align:start position:0% +coupling terms so you have a model where + + + align:start position:0% +coupling terms so you have a model where +you fit the energy levels and what you + + align:start position:0% +you fit the energy levels and what you + + + align:start position:0% +you fit the energy levels and what you +fit in the energy level should be + + align:start position:0% +fit in the energy level should be + + + align:start position:0% +fit in the energy level should be +related to the fundamental parameters in + + align:start position:0% +related to the fundamental parameters in + + + align:start position:0% +related to the fundamental parameters in +these two so all three of these things + + align:start position:0% +these two so all three of these things + + + align:start position:0% +these two so all three of these things +are related and the pages from the paper + + align:start position:0% +are related and the pages from the paper + + + align:start position:0% +are related and the pages from the paper +show how you relate the various + + align:start position:0% +show how you relate the various + + + align:start position:0% +show how you relate the various +quantities there's a lot of insight into + + align:start position:0% +quantities there's a lot of insight into + + + align:start position:0% +quantities there's a lot of insight into +uh the Rel gain from the relationships + + align:start position:0% +uh the Rel gain from the relationships + + + align:start position:0% +uh the Rel gain from the relationships +between these two the last word is as is + + align:start position:0% +between these two the last word is as is + + + align:start position:0% +between these two the last word is as is +always + + align:start position:0% +always + + + align:start position:0% +always +true uh in + + align:start position:0% +true uh in + + + align:start position:0% +true uh in +um uh problems in + + align:start position:0% +um uh problems in + + + align:start position:0% +um uh problems in +spectroscopy you have a war between a + + align:start position:0% +spectroscopy you have a war between a + + + align:start position:0% +spectroscopy you have a war between a +term that tries to make things simple + + align:start position:0% +term that tries to make things simple + + + align:start position:0% +term that tries to make things simple +and a term that tries to make things + + align:start position:0% +and a term that tries to make things + + + align:start position:0% +and a term that tries to make things +complicated and there's usually two + + align:start position:0% +complicated and there's usually two + + + align:start position:0% +complicated and there's usually two +representations and the role of the + + align:start position:0% +representations and the role of the + + + align:start position:0% +representations and the role of the +destroying term and the saving term get + + align:start position:0% +destroying term and the saving term get + + + align:start position:0% +destroying term and the saving term get +switched in the two + + align:start position:0% +switched in the two + + + align:start position:0% +switched in the two +representations and this local and + + align:start position:0% +representations and this local and + + + align:start position:0% +representations and this local and +normal picture are is a beautifully + + align:start position:0% +normal picture are is a beautifully + + + align:start position:0% +normal picture are is a beautifully +instructive situation where you see how + + align:start position:0% +instructive situation where you see how + + + align:start position:0% +instructive situation where you see how +what destroys the regularity in one + + align:start position:0% +what destroys the regularity in one + + + align:start position:0% +what destroys the regularity in one +model preserves in the other and after + + align:start position:0% +model preserves in the other and after + + + align:start position:0% +model preserves in the other and after +all you're trying to the the molecule is + + align:start position:0% +all you're trying to the the molecule is + + + align:start position:0% +all you're trying to the the molecule is +trying to go from this to this so if + + align:start position:0% +trying to go from this to this so if + + + align:start position:0% +trying to go from this to this so if +something is good here it has to be bad + + align:start position:0% +something is good here it has to be bad + + + align:start position:0% +something is good here it has to be bad +here and vice + + align:start position:0% +here and vice + + + align:start position:0% +here and vice +versa but this is so Universal in in + + align:start position:0% +versa but this is so Universal in in + + + align:start position:0% +versa but this is so Universal in in +spectroscopy that as soon as you get + + align:start position:0% +spectroscopy that as soon as you get + + + align:start position:0% +spectroscopy that as soon as you get +away from textbook Spectra you have a + + align:start position:0% +away from textbook Spectra you have a + + + align:start position:0% +away from textbook Spectra you have a +choice of two representations and the + + align:start position:0% +choice of two representations and the + + + align:start position:0% +choice of two representations and the +role played by the good and bad terms is + + align:start position:0% +role played by the good and bad terms is + + + align:start position:0% +role played by the good and bad terms is +reversed and and uh you never get + + align:start position:0% +reversed and and uh you never get + + + align:start position:0% +reversed and and uh you never get +something for nothing you never for + + align:start position:0% +something for nothing you never for + + + align:start position:0% +something for nothing you never for +example in redberg States going to case + + align:start position:0% +example in redberg States going to case + + + align:start position:0% +example in redberg States going to case +D is a wonderful thing because the + + align:start position:0% +D is a wonderful thing because the + + + align:start position:0% +D is a wonderful thing because the +rotational hamiltonian becomes diagonal + + align:start position:0% +rotational hamiltonian becomes diagonal + + + align:start position:0% +rotational hamiltonian becomes diagonal +but magically the electronic hamiltonian + + align:start position:0% +but magically the electronic hamiltonian + + + align:start position:0% +but magically the electronic hamiltonian +becomes off diagonal and most people + + align:start position:0% +becomes off diagonal and most people + + + align:start position:0% +becomes off diagonal and most people +don't know about that and so they think + + align:start position:0% +don't know about that and so they think + + + align:start position:0% +don't know about that and so they think +oh it's just great let's just do this so + + align:start position:0% +oh it's just great let's just do this so + + + align:start position:0% +oh it's just great let's just do this so +there are many many cases where you know + + align:start position:0% +there are many many cases where you know + + + align:start position:0% +there are many many cases where you know +uh you're going to be going between + + align:start position:0% +uh you're going to be going between + + + align:start position:0% +uh you're going to be going between +these two representations there's one + + align:start position:0% +these two representations there's one + + + align:start position:0% +these two representations there's one +that's always better than the other for + + align:start position:0% +that's always better than the other for + + + align:start position:0% +that's always better than the other for +the particular case + + align:start position:0% +the particular case + + + align:start position:0% +the particular case +but um you have to be careful about + + align:start position:0% +but um you have to be careful about + + + align:start position:0% +but um you have to be careful about +remembering what's good and what's bad + + align:start position:0% +remembering what's good and what's bad + + + align:start position:0% +remembering what's good and what's bad +it's all + + align:start position:0% +it's all + + + align:start position:0% +it's all +relative okay so that's that's it I'm + + align:start position:0% +relative okay so that's that's it I'm + + + align:start position:0% +relative okay so that's that's it I'm +not sure what I'm going to do next week + + align:start position:0% +not sure what I'm going to do next week + + + align:start position:0% +not sure what I'm going to do next week +but we're getting close to the end I + + align:start position:0% +but we're getting close to the end I + + + align:start position:0% +but we're getting close to the end I +think I'm not quite finished with + + align:start position:0% +think I'm not quite finished with + + + align:start position:0% +think I'm not quite finished with +vibrations but we'll see \ No newline at end of file diff --git a/LbKKzMag5Rc.txt b/LbKKzMag5Rc.txt new file mode 100644 index 0000000000000000000000000000000000000000..523870b51f19da333226dcad2cd8431c3d3ed480 --- /dev/null +++ b/LbKKzMag5Rc.txt @@ -0,0 +1,8163 @@ +align:start position:0% + +oh the + + align:start position:0% +oh the + + + align:start position:0% +oh the +[Applause] + + align:start position:0% + + + + align:start position:0% + +uh the topic for today is + + align:start position:0% + + + + align:start position:0% + +the uh today we're going to talk uh I'm + + align:start position:0% +the uh today we're going to talk uh I'm + + + align:start position:0% +the uh today we're going to talk uh I'm +postponing the linear equation to next + + align:start position:0% +postponing the linear equation to next + + + align:start position:0% +postponing the linear equation to next +time uh instead uh I think it's a good + + align:start position:0% +time uh instead uh I think it's a good + + + align:start position:0% +time uh instead uh I think it's a good +idea since in real life most of the + + align:start position:0% +idea since in real life most of the + + + align:start position:0% +idea since in real life most of the +differential equations are solved by + + align:start position:0% +differential equations are solved by + + + align:start position:0% +differential equations are solved by +numerical methods to introduce you to + + align:start position:0% +numerical methods to introduce you to + + + align:start position:0% +numerical methods to introduce you to +those right away even when you see the + + align:start position:0% +those right away even when you see the + + + align:start position:0% +those right away even when you see the +compu where you saw the computer screen + + align:start position:0% +compu where you saw the computer screen + + + align:start position:0% +compu where you saw the computer screen +uh the solutions being drawn of course + + align:start position:0% +uh the solutions being drawn of course + + + align:start position:0% +uh the solutions being drawn of course +that what really was happening is that + + align:start position:0% +that what really was happening is that + + + align:start position:0% +that what really was happening is that +the computer was calculating the + + align:start position:0% +the computer was calculating the + + + align:start position:0% +the computer was calculating the +solutions numerically and plotting the + + align:start position:0% +solutions numerically and plotting the + + + align:start position:0% +solutions numerically and plotting the +points + + align:start position:0% +points + + + align:start position:0% +points +so this is the main way numerically is + + align:start position:0% +so this is the main way numerically is + + + align:start position:0% +so this is the main way numerically is +the main way differential equations are + + align:start position:0% +the main way differential equations are + + + align:start position:0% +the main way differential equations are +actually solved there of any complexity + + align:start position:0% +actually solved there of any complexity + + + align:start position:0% +actually solved there of any complexity +at all now so the problem is an initial + + align:start position:0% +at all now so the problem is an initial + + + align:start position:0% +at all now so the problem is an initial +value problem let's write it A first + + align:start position:0% +value problem let's write it A first + + + align:start position:0% +value problem let's write it A first +order problem the way we talked about it + + align:start position:0% +order problem the way we talked about it + + + align:start position:0% +order problem the way we talked about it +on + + align:start position:0% +on + + + align:start position:0% +on +Wednesday uh and now I'll specifically + + align:start position:0% +Wednesday uh and now I'll specifically + + + align:start position:0% +Wednesday uh and now I'll specifically +add to that the starting point that you + + align:start position:0% +add to that the starting point that you + + + align:start position:0% +add to that the starting point that you +used when you did the computer + + align:start position:0% +used when you did the computer + + + align:start position:0% +used when you did the computer +experiments and I'll write the starting + + align:start position:0% +experiments and I'll write the starting + + + align:start position:0% +experiments and I'll write the starting +point this way so y of x0 should be y0 + + align:start position:0% +point this way so y of x0 should be y0 + + + align:start position:0% +point this way so y of x0 should be y0 +so this is the initial condition and + + align:start position:0% +so this is the initial condition and + + + align:start position:0% +so this is the initial condition and +this is the first order differential + + align:start position:0% +this is the first order differential + + + align:start position:0% +this is the first order differential +equation and as you know the two of them + + align:start position:0% +equation and as you know the two of them + + + align:start position:0% +equation and as you know the two of them +together are called an ivp an initial + + align:start position:0% +together are called an ivp an initial + + + align:start position:0% +together are called an ivp an initial +value problem which means two things the + + align:start position:0% +value problem which means two things the + + + align:start position:0% +value problem which means two things the +differential equation and the initial + + align:start position:0% +differential equation and the initial + + + align:start position:0% +differential equation and the initial +value uh that you are want to start the + + align:start position:0% +value uh that you are want to start the + + + align:start position:0% +value uh that you are want to start the +solution at + + align:start position:0% +solution at + + + align:start position:0% +solution at +okay the uh now the + + align:start position:0% +okay the uh now the + + + align:start position:0% +okay the uh now the +method we're going to talk about the + + align:start position:0% +method we're going to talk about the + + + align:start position:0% +method we're going to talk about the +basic method of which many others are + + align:start position:0% +basic method of which many others are + + + align:start position:0% +basic method of which many others are +merely refinements in one way or another + + align:start position:0% +merely refinements in one way or another + + + align:start position:0% +merely refinements in one way or another +is uh called Oilers + + align:start position:0% + + + + align:start position:0% + +method Oiler who did of course + + align:start position:0% +method Oiler who did of course + + + align:start position:0% +method Oiler who did of course +everything in analysis did + + align:start position:0% +everything in analysis did + + + align:start position:0% +everything in analysis did +as far as I know didn't actually use it + + align:start position:0% +as far as I know didn't actually use it + + + align:start position:0% +as far as I know didn't actually use it +to compute Solutions of differential + + align:start position:0% +to compute Solutions of differential + + + align:start position:0% +to compute Solutions of differential +equations his interest was theoretical + + align:start position:0% +equations his interest was theoretical + + + align:start position:0% +equations his interest was theoretical +uh he used it as a method of proving the + + align:start position:0% +uh he used it as a method of proving the + + + align:start position:0% +uh he used it as a method of proving the +existence theorem that proving that + + align:start position:0% +existence theorem that proving that + + + align:start position:0% +existence theorem that proving that +Solutions + + align:start position:0% +Solutions + + + align:start position:0% +Solutions +existed but uh nowadays it's used to + + align:start position:0% +existed but uh nowadays it's used to + + + align:start position:0% +existed but uh nowadays it's used to +calculate the solutions numerically and + + align:start position:0% +calculate the solutions numerically and + + + align:start position:0% +calculate the solutions numerically and +the method is very simple to describe + + align:start position:0% +the method is very simple to describe + + + align:start position:0% +the method is very simple to describe +it's so naive if you probably think that + + align:start position:0% +it's so naive if you probably think that + + + align:start position:0% +it's so naive if you probably think that +if you had been living 300 years ago you + + align:start position:0% +if you had been living 300 years ago you + + + align:start position:0% +if you had been living 300 years ago you +would have discovered a and covered + + align:start position:0% +would have discovered a and covered + + + align:start position:0% +would have discovered a and covered +yourself with glory for all + + align:start position:0% +yourself with glory for all + + + align:start position:0% +yourself with glory for all +eternity here is uh so here is our + + align:start position:0% +eternity here is uh so here is our + + + align:start position:0% +eternity here is uh so here is our +starting point uh x0 + + align:start position:0% + + + + align:start position:0% + +y0 now what information do we have at + + align:start position:0% +y0 now what information do we have at + + + align:start position:0% +y0 now what information do we have at +that point all we have is the little + + align:start position:0% +that point all we have is the little + + + align:start position:0% +that point all we have is the little +line element whose slope is given by F + + align:start position:0% +line element whose slope is given by F + + + align:start position:0% +line element whose slope is given by F +ofx Y so if I start the solution the + + align:start position:0% +ofx Y so if I start the solution the + + + align:start position:0% +ofx Y so if I start the solution the +only way the solution could possibly go + + align:start position:0% +only way the solution could possibly go + + + align:start position:0% +only way the solution could possibly go +would be to start off in that Direction + + align:start position:0% +would be to start off in that Direction + + + align:start position:0% +would be to start off in that Direction +since I have no other + + align:start position:0% +since I have no other + + + align:start position:0% +since I have no other +information at least it's cor has the + + align:start position:0% +information at least it's cor has the + + + align:start position:0% +information at least it's cor has the +correct direction at x0 y0 but of course + + align:start position:0% +correct direction at x0 y0 but of course + + + align:start position:0% +correct direction at x0 y0 but of course +it's not likely to have the correct + + align:start position:0% +it's not likely to have the correct + + + align:start position:0% +it's not likely to have the correct +direction anywhere else now what you do + + align:start position:0% +direction anywhere else now what you do + + + align:start position:0% +direction anywhere else now what you do +then is choose a step size I'll draw + + align:start position:0% +then is choose a step size I'll draw + + + align:start position:0% +then is choose a step size I'll draw +just a few two steps of the method + + align:start position:0% +just a few two steps of the method + + + align:start position:0% +just a few two steps of the method +that's I think good enough uh you choose + + align:start position:0% +that's I think good enough uh you choose + + + align:start position:0% +that's I think good enough uh you choose +a steps a uniform step size which is + + align:start position:0% +a steps a uniform step size which is + + + align:start position:0% +a steps a uniform step size which is +usually called + + align:start position:0% +usually called + + + align:start position:0% +usually called +H and you continue that solution until + + align:start position:0% +H and you continue that solution until + + + align:start position:0% +H and you continue that solution until +you get to the next point which will be + + align:start position:0% +you get to the next point which will be + + + align:start position:0% +you get to the next point which will be +x0 plus h as I've drawn it on the + + align:start position:0% +x0 plus h as I've drawn it on the + + + align:start position:0% +x0 plus h as I've drawn it on the +picture so we get to here uh we stop at + + align:start position:0% +picture so we get to here uh we stop at + + + align:start position:0% +picture so we get to here uh we stop at +that point and now you recalculate what + + align:start position:0% +that point and now you recalculate what + + + align:start position:0% +that point and now you recalculate what +the line element is here suppose here + + align:start position:0% +the line element is here suppose here + + + align:start position:0% +the line element is here suppose here +the line element now through this point + + align:start position:0% +the line element now through this point + + + align:start position:0% +the line element now through this point +goes like that well then that's the new + + align:start position:0% +goes like that well then that's the new + + + align:start position:0% +goes like that well then that's the new +direction that you should start out with + + align:start position:0% +direction that you should start out with + + + align:start position:0% +direction that you should start out with +going from here and so the next step of + + align:start position:0% +going from here and so the next step of + + + align:start position:0% +going from here and so the next step of +the process will carry you to here + + align:start position:0% +the process will carry you to here + + + align:start position:0% +the process will carry you to here +that's two steps of Oilers method notice + + align:start position:0% +that's two steps of Oilers method notice + + + align:start position:0% +that's two steps of Oilers method notice +it produces a broken line approximation + + align:start position:0% +it produces a broken line approximation + + + align:start position:0% +it produces a broken line approximation +to the solution but in fact you only see + + align:start position:0% +to the solution but in fact you only see + + + align:start position:0% +to the solution but in fact you only see +that broken + + align:start position:0% +that broken + + + align:start position:0% +that broken +line if you're at a computer if you're + + align:start position:0% +line if you're at a computer if you're + + + align:start position:0% +line if you're at a computer if you're +uh looking at the computer visual for + + align:start position:0% +uh looking at the computer visual for + + + align:start position:0% +uh looking at the computer visual for +example which is whose purpose is to + + align:start position:0% +example which is whose purpose is to + + + align:start position:0% +example which is whose purpose is to +illustrate for you Oilers method in + + align:start position:0% +illustrate for you Oilers method in + + + align:start position:0% +illustrate for you Oilers method in +actual practice what you see is just the + + align:start position:0% +actual practice what you see is just the + + + align:start position:0% +actual practice what you see is just the +computer is simply calculating this + + align:start position:0% +computer is simply calculating this + + + align:start position:0% +computer is simply calculating this +point that point that point and the + + align:start position:0% +point that point that point and the + + + align:start position:0% +point that point that point and the +succession of points and many programs + + align:start position:0% +succession of points and many programs + + + align:start position:0% +succession of points and many programs +will just automatically connect those + + align:start position:0% +will just automatically connect those + + + align:start position:0% +will just automatically connect those +points by a smooth looking curve if uh + + align:start position:0% +points by a smooth looking curve if uh + + + align:start position:0% +points by a smooth looking curve if uh +that's what you prefer to + + align:start position:0% +that's what you prefer to + + + align:start position:0% +that's what you prefer to +see well that's that's all there is to + + align:start position:0% +see well that's that's all there is to + + + align:start position:0% +see well that's that's all there is to +the method uh what we have to do now is + + align:start position:0% +the method uh what we have to do now is + + + align:start position:0% +the method uh what we have to do now is +derive the equations for the + + align:start position:0% +derive the equations for the + + + align:start position:0% +derive the equations for the +method how are we going to do that well + + align:start position:0% +method how are we going to do that well + + + align:start position:0% +method how are we going to do that well +the essence of it is how to get from the + + align:start position:0% +the essence of it is how to get from the + + + align:start position:0% +the essence of it is how to get from the +nth step to the N plus First Step so I'm + + align:start position:0% +nth step to the N plus First Step so I'm + + + align:start position:0% +nth step to the N plus First Step so I'm +going to draw that a picture just to + + align:start position:0% +going to draw that a picture just to + + + align:start position:0% +going to draw that a picture just to +illustr + + align:start position:0% +illustr + + + align:start position:0% +illustr +that so now we're not at x0 but let's + + align:start position:0% +that so now we're not at x0 but let's + + + align:start position:0% +that so now we're not at x0 but let's +say we've already gotten to xn + + align:start position:0% + + + + align:start position:0% + +YN how do I take the next step well I + + align:start position:0% +YN how do I take the next step well I + + + align:start position:0% +YN how do I take the next step well I +take the line element and it goes up + + align:start position:0% +take the line element and it goes up + + + align:start position:0% +take the line element and it goes up +like that let's say because the slope is + + align:start position:0% +like that let's say because the slope is + + + align:start position:0% +like that let's say because the slope is +uh this I'm going to call that slope a + + align:start position:0% +uh this I'm going to call that slope a + + + align:start position:0% +uh this I'm going to call that slope a +subn of course a subn is the value of + + align:start position:0% +subn of course a subn is the value of + + + align:start position:0% +subn of course a subn is the value of +the right hand side at the point xn1 YN + + align:start position:0% +the right hand side at the point xn1 YN + + + align:start position:0% +the right hand side at the point xn1 YN +and we'll need that in the equation but + + align:start position:0% +and we'll need that in the equation but + + + align:start position:0% +and we'll need that in the equation but +I think it will be a little clearer if I + + align:start position:0% +I think it will be a little clearer if I + + + align:start position:0% +I think it will be a little clearer if I +just give it a capital letter at this + + align:start position:0% +just give it a capital letter at this + + + align:start position:0% +just give it a capital letter at this +point + + align:start position:0% +point + + + align:start position:0% +point +now how this is the new point and all I + + align:start position:0% +now how this is the new point and all I + + + align:start position:0% +now how this is the new point and all I +want to know is what are its coordinates + + align:start position:0% +want to know is what are its coordinates + + + align:start position:0% +want to know is what are its coordinates +well the xn + one is there the YN + one + + align:start position:0% +well the xn + one is there the YN + one + + + align:start position:0% +well the xn + one is there the YN + one +is + + align:start position:0% +is + + + align:start position:0% +is +here clearly I should draw this triangle + + align:start position:0% +here clearly I should draw this triangle + + + align:start position:0% +here clearly I should draw this triangle +complete the + + align:start position:0% +complete the + + + align:start position:0% +complete the +triangle this side of the triangle this + + align:start position:0% +triangle this side of the triangle this + + + align:start position:0% +triangle this side of the triangle this +the hypotenuse has slope a n this side + + align:start position:0% +the hypotenuse has slope a n this side + + + align:start position:0% +the hypotenuse has slope a n this side +of the triangle has length H H is the + + align:start position:0% +of the triangle has length H H is the + + + align:start position:0% +of the triangle has length H H is the +step size perhaps I better indicate that + + align:start position:0% +step size perhaps I better indicate that + + + align:start position:0% +step size perhaps I better indicate that +actually put that up so that you know + + align:start position:0% +actually put that up so that you know + + + align:start position:0% +actually put that up so that you know +the word step size it means how it's the + + align:start position:0% +the word step size it means how it's the + + + align:start position:0% +the word step size it means how it's the +step size on the x axis how far you have + + align:start position:0% +step size on the x axis how far you have + + + align:start position:0% +step size on the x axis how far you have +to go to get from each x to the next + + align:start position:0% +to go to get from each x to the next + + + align:start position:0% +to go to get from each x to the next +one what's this well if that slope has + + align:start position:0% +one what's this well if that slope has + + + align:start position:0% +one what's this well if that slope has +this the slope a n this is H then this + + align:start position:0% +this the slope a n this is H then this + + + align:start position:0% +this the slope a n this is H then this +must be H * a + + align:start position:0% +must be H * a + + + align:start position:0% +must be H * a +n the length of that side + + align:start position:0% +n the length of that side + + + align:start position:0% +n the length of that side +right in order that the ratio of the + + align:start position:0% +right in order that the ratio of the + + + align:start position:0% +right in order that the ratio of the +height to this width should be a n and + + align:start position:0% +height to this width should be a n and + + + align:start position:0% +height to this width should be a n and +that gives us the + + align:start position:0% +that gives us the + + + align:start position:0% +that gives us the +method what's + + align:start position:0% +method what's + + + align:start position:0% +method what's +the how do I get from uh clearly to get + + align:start position:0% +the how do I get from uh clearly to get + + + align:start position:0% +the how do I get from uh clearly to get +from xn to xn plus one I simply add H so + + align:start position:0% +from xn to xn plus one I simply add H so + + + align:start position:0% +from xn to xn plus one I simply add H so +that's the trivial part of it the + + align:start position:0% +that's the trivial part of it the + + + align:start position:0% +that's the trivial part of it the +interesting thing is how do I get the + + align:start position:0% +interesting thing is how do I get the + + + align:start position:0% +interesting thing is how do I get the +new YN + one and so the best way to + + align:start position:0% +new YN + one and so the best way to + + + align:start position:0% +new YN + one and so the best way to +write it as that YN + 1us + + align:start position:0% +write it as that YN + 1us + + + align:start position:0% +write it as that YN + 1us +YN divided by + + align:start position:0% +YN divided by + + + align:start position:0% +YN divided by +H well YN sorry YN + 1 minus YN is is + + align:start position:0% +H well YN sorry YN + 1 minus YN is is + + + align:start position:0% +H well YN sorry YN + 1 minus YN is is +this line the same as the line H * a n + + align:start position:0% +this line the same as the line H * a n + + + align:start position:0% +this line the same as the line H * a n +so that's the way to write + + align:start position:0% + + + + align:start position:0% + +it or since the computer is interested + + align:start position:0% +it or since the computer is interested + + + align:start position:0% +it or since the computer is interested +in calculating YN + one itself put this + + align:start position:0% +in calculating YN + one itself put this + + + align:start position:0% +in calculating YN + one itself put this +on the other side it you take the old YN + + align:start position:0% +on the other side it you take the old YN + + + align:start position:0% +on the other side it you take the old YN +the previous one and to it you add H + + align:start position:0% +the previous one and to it you add H + + + align:start position:0% +the previous one and to it you add H +time a n and what prel is a n well the + + align:start position:0% +time a n and what prel is a n well the + + + align:start position:0% +time a n and what prel is a n well the +computer has to be told that a n is the + + align:start position:0% +computer has to be told that a n is the + + + align:start position:0% +computer has to be told that a n is the +value of f so now with that let's + + align:start position:0% +value of f so now with that let's + + + align:start position:0% +value of f so now with that let's +actually write the oiler program not the + + align:start position:0% +actually write the oiler program not the + + + align:start position:0% +actually write the oiler program not the +program but the oiler the oiler method + + align:start position:0% +program but the oiler the oiler method + + + align:start position:0% +program but the oiler the oiler method +equations let's just call it the oiler + + align:start position:0% +equations let's just call it the oiler + + + align:start position:0% +equations let's just call it the oiler +equations what will they be first of all + + align:start position:0% +equations what will they be first of all + + + align:start position:0% +equations what will they be first of all +the new X is the old x + + + align:start position:0% +the new X is the old x + + + + align:start position:0% +the new X is the old x + +H the new Y is is just what I've written + + align:start position:0% +H the new Y is is just what I've written + + + align:start position:0% +H the new Y is is just what I've written +there the old y plus h * a certain + + align:start position:0% +there the old y plus h * a certain + + + align:start position:0% +there the old y plus h * a certain +number a n and finally a n has the value + + align:start position:0% +number a n and finally a n has the value + + + align:start position:0% +number a n and finally a n has the value +it's the slope of the line element here + + align:start position:0% +it's the slope of the line element here + + + align:start position:0% +it's the slope of the line element here +and therefore by definition that's F of + + align:start position:0% +and therefore by definition that's F of + + + align:start position:0% +and therefore by definition that's F of +xn + + align:start position:0% +xn + + + align:start position:0% +xn +YN so it's these three equations which + + align:start position:0% +YN so it's these three equations which + + + align:start position:0% +YN so it's these three equations which +Define Oilers method if I assume in 100 + + align:start position:0% +Define Oilers method if I assume in 100 + + + align:start position:0% +Define Oilers method if I assume in 100 +surely you must be asked is uh to at + + align:start position:0% +surely you must be asked is uh to at + + + align:start position:0% +surely you must be asked is uh to at +some point as an exercise in the term at + + align:start position:0% +some point as an exercise in the term at + + + align:start position:0% +some point as an exercise in the term at +one point to uh to uh calculate to + + align:start position:0% +one point to uh to uh calculate to + + + align:start position:0% +one point to uh to uh calculate to +program the computer in C or whatever + + align:start position:0% +program the computer in C or whatever + + + align:start position:0% +program the computer in C or whatever +they're using Java now I guess uh to do + + align:start position:0% +they're using Java now I guess uh to do + + + align:start position:0% +they're using Java now I guess uh to do +Oiler Oilers method and these are the + + align:start position:0% +Oiler Oilers method and these are the + + + align:start position:0% +Oiler Oilers method and these are the +equations you these would be the + + align:start position:0% +equations you these would be the + + + align:start position:0% +equations you these would be the +recursive equations that you would put + + align:start position:0% +recursive equations that you would put + + + align:start position:0% +recursive equations that you would put +in to do + + align:start position:0% +in to do + + + align:start position:0% +in to do +that okay uh let's try uh an example + + align:start position:0% +that okay uh let's try uh an example + + + align:start position:0% +that okay uh let's try uh an example +then + + align:start position:0% + + + + align:start position:0% + +so what would be a good color for wher + + align:start position:0% +so what would be a good color for wher + + + align:start position:0% +so what would be a good color for wher +well a purple I assume nobody can see + + align:start position:0% +well a purple I assume nobody can see + + + align:start position:0% +well a purple I assume nobody can see +purple is that + + align:start position:0% +purple is that + + + align:start position:0% +purple is that +correct can anyone in the back of the + + align:start position:0% +correct can anyone in the back of the + + + align:start position:0% +correct can anyone in the back of the +room see that that that's + + align:start position:0% +room see that that that's + + + align:start position:0% +room see that that that's +purple + + align:start position:0% +purple + + + align:start position:0% +purple +what okay sit + + align:start position:0% + + + + align:start position:0% + +closer so let's calculate uh the example + + align:start position:0% +closer so let's calculate uh the example + + + align:start position:0% +closer so let's calculate uh the example +I'll use a simple example but it's not + + align:start position:0% +I'll use a simple example but it's not + + + align:start position:0% +I'll use a simple example but it's not +entirely trivial + + align:start position:0% +entirely trivial + + + align:start position:0% +entirely trivial +my example is going to be the equation + + align:start position:0% +my example is going to be the equation + + + align:start position:0% +my example is going to be the equation +x^2 - y^2 on the right hand side and + + align:start position:0% +x^2 - y^2 on the right hand side and + + + align:start position:0% +x^2 - y^2 on the right hand side and +let's start with Y of 0 equals one let's + + align:start position:0% +let's start with Y of 0 equals one let's + + + align:start position:0% +let's start with Y of 0 equals one let's +say and so this is my initial value + + align:start position:0% +say and so this is my initial value + + + align:start position:0% +say and so this is my initial value +problem that pair of equations and uh I + + align:start position:0% +problem that pair of equations and uh I + + + align:start position:0% +problem that pair of equations and uh I +have to specify a step size so let's + + align:start position:0% +have to specify a step size so let's + + + align:start position:0% +have to specify a step size so let's +take the step size to be + + align:start position:0% +take the step size to be + + + align:start position:0% +take the step size to be +0.1 you choose the step size or the + + align:start position:0% +0.1 you choose the step size or the + + + align:start position:0% +0.1 you choose the step size or the +computer does uh we'll have to talk + + align:start position:0% +computer does uh we'll have to talk + + + align:start position:0% +computer does uh we'll have to talk +about that in a few minutes + + align:start position:0% +about that in a few minutes + + + align:start position:0% +about that in a few minutes +now what do you do + + align:start position:0% +now what do you do + + + align:start position:0% +now what do you do +well I say this is a non-trivial + + align:start position:0% +well I say this is a non-trivial + + + align:start position:0% +well I say this is a non-trivial +equation because uh this equation as far + + align:start position:0% +equation because uh this equation as far + + + align:start position:0% +equation because uh this equation as far +as I know cannot be solved in terms of + + align:start position:0% +as I know cannot be solved in terms of + + + align:start position:0% +as I know cannot be solved in terms of +Elementary functions so this equation + + align:start position:0% +Elementary functions so this equation + + + align:start position:0% +Elementary functions so this equation +would be in fact a very good candidate + + align:start position:0% +would be in fact a very good candidate + + + align:start position:0% +would be in fact a very good candidate +for numerical a numerical method like + + align:start position:0% +for numerical a numerical method like + + + align:start position:0% +for numerical a numerical method like +Oilers and you had to use it or maybe it + + align:start position:0% +Oilers and you had to use it or maybe it + + + align:start position:0% +Oilers and you had to use it or maybe it +was the other way around I forget on + + align:start position:0% +was the other way around I forget on + + + align:start position:0% +was the other way around I forget on +your problem Set uh you drew a picture + + align:start position:0% +your problem Set uh you drew a picture + + + align:start position:0% +your problem Set uh you drew a picture +of the direction field and answered some + + align:start position:0% +of the direction field and answered some + + + align:start position:0% +of the direction field and answered some +questions about the iines + + align:start position:0% +questions about the iines + + + align:start position:0% +questions about the iines +how the solutions behave all right now + + align:start position:0% +how the solutions behave all right now + + + align:start position:0% +how the solutions behave all right now +the main thing I want you to get uh this + + align:start position:0% +the main thing I want you to get uh this + + + align:start position:0% +the main thing I want you to get uh this +is not just for Oilers talking about + + align:start position:0% +is not just for Oilers talking about + + + align:start position:0% +is not just for Oilers talking about +Oilers equations but in + + align:start position:0% +Oilers equations but in + + + align:start position:0% +Oilers equations but in +general for the calculations you have to + + align:start position:0% +general for the calculations you have to + + + align:start position:0% +general for the calculations you have to +do in this course it's extremely + + align:start position:0% +do in this course it's extremely + + + align:start position:0% +do in this course it's extremely +important to be systematic because if + + align:start position:0% +important to be systematic because if + + + align:start position:0% +important to be systematic because if +you are not systematic you know if you + + align:start position:0% +you are not systematic you know if you + + + align:start position:0% +you are not systematic you know if you +just scribble scribble scribble scribble + + align:start position:0% +just scribble scribble scribble scribble + + + align:start position:0% +just scribble scribble scribble scribble +scribble you can do the work but it + + align:start position:0% +scribble you can do the work but it + + + align:start position:0% +scribble you can do the work but it +becomes impossible to find + + align:start position:0% +becomes impossible to find + + + align:start position:0% +becomes impossible to find +mistakes you must do the work in a form + + align:start position:0% +mistakes you must do the work in a form + + + align:start position:0% +mistakes you must do the work in a form +in which which you can check in which it + + align:start position:0% +in which which you can check in which it + + + align:start position:0% +in which which you can check in which it +can be checked which you can look over + + align:start position:0% +can be checked which you can look over + + + align:start position:0% +can be checked which you can look over +it find and try to see where mistakes + + align:start position:0% +it find and try to see where mistakes + + + align:start position:0% +it find and try to see where mistakes +are if in fact there are any so I I + + align:start position:0% +are if in fact there are any so I I + + + align:start position:0% +are if in fact there are any so I I +strongly + + align:start position:0% +strongly + + + align:start position:0% +strongly +suggest uh this is not a suggestion this + + align:start position:0% +suggest uh this is not a suggestion this + + + align:start position:0% +suggest uh this is not a suggestion this +is a command uh that you make a little + + align:start position:0% +is a command uh that you make a little + + + align:start position:0% +is a command uh that you make a little +tight to do a Oilers method by hand I'd + + align:start position:0% +tight to do a Oilers method by hand I'd + + + align:start position:0% +tight to do a Oilers method by hand I'd +only ask you for a step or two since I'm + + align:start position:0% +only ask you for a step or two since I'm + + + align:start position:0% +only ask you for a step or two since I'm +just trying to make sure you have some + + align:start position:0% +just trying to make sure you have some + + + align:start position:0% +just trying to make sure you have some +idea of these equations and where they + + align:start position:0% +idea of these equations and where they + + + align:start position:0% +idea of these equations and where they +come from + + align:start position:0% +come from + + + align:start position:0% +come from +so first the value of n then the value + + align:start position:0% +so first the value of n then the value + + + align:start position:0% +so first the value of n then the value +of xn then the value of the + + align:start position:0% +of xn then the value of the + + + align:start position:0% +of xn then the value of the +YN and then a couple of more columns + + align:start position:0% +YN and then a couple of more columns + + + align:start position:0% +YN and then a couple of more columns +which tell you what the calcul how to do + + align:start position:0% +which tell you what the calcul how to do + + + align:start position:0% +which tell you what the calcul how to do +the calculation you're going to need the + + align:start position:0% +the calculation you're going to need the + + + align:start position:0% +the calculation you're going to need the +value of the + + align:start position:0% +value of the + + + align:start position:0% +value of the +slope and it's probably a good idea also + + align:start position:0% +slope and it's probably a good idea also + + + align:start position:0% +slope and it's probably a good idea also +because otherwise you'll forget it to + + align:start position:0% +because otherwise you'll forget it to + + + align:start position:0% +because otherwise you'll forget it to +put in h a because that occurs in the + + align:start position:0% +put in h a because that occurs in the + + + align:start position:0% +put in h a because that occurs in the +formula all right let's start doing it + + align:start position:0% +formula all right let's start doing it + + + align:start position:0% +formula all right let's start doing it +well the first value of n is zero that's + + align:start position:0% +well the first value of n is zero that's + + + align:start position:0% +well the first value of n is zero that's +the starting point at the starting point + + align:start position:0% +the starting point at the starting point + + + align:start position:0% +the starting point at the starting point +x0 y0 x has the value zero and Y has the + + align:start position:0% +x0 y0 x has the value zero and Y has the + + + align:start position:0% +x0 y0 x has the value zero and Y has the +value one so zero and + + align:start position:0% +value one so zero and + + + align:start position:0% +value one so zero and +one in other words I'm starting I'm + + align:start position:0% +one in other words I'm starting I'm + + + align:start position:0% +one in other words I'm starting I'm +carrying out exactly what I drew + + align:start position:0% +carrying out exactly what I drew + + + align:start position:0% +carrying out exactly what I drew +pictorially only now I'm doing it + + align:start position:0% +pictorially only now I'm doing it + + + align:start position:0% +pictorially only now I'm doing it +arithmetically using a table and + + align:start position:0% +arithmetically using a table and + + + align:start position:0% +arithmetically using a table and +substituting into the formulas okay the + + align:start position:0% +substituting into the formulas okay the + + + align:start position:0% +substituting into the formulas okay the +next thing we have to calc Cal is a n + + align:start position:0% +next thing we have to calc Cal is a n + + + align:start position:0% +next thing we have to calc Cal is a n +well that's since a n is the value of + + align:start position:0% +well that's since a n is the value of + + + align:start position:0% +well that's since a n is the value of +the right hand + + align:start position:0% +the right hand + + + align:start position:0% +the right hand +side at the 01 you have to plug that in + + align:start position:0% +side at the 01 you have to plug that in + + + align:start position:0% +side at the 01 you have to plug that in +the right hand side is x0 x^2 - y^2 so + + align:start position:0% +the right hand side is x0 x^2 - y^2 so + + + align:start position:0% +the right hand side is x0 x^2 - y^2 so +it's 0^ 2us 1^ squar the value of the + + align:start position:0% +it's 0^ 2us 1^ squar the value of the + + + align:start position:0% +it's 0^ 2us 1^ squar the value of the +slope there is minus one negative 1 now + + align:start position:0% +slope there is minus one negative 1 now + + + align:start position:0% +slope there is minus one negative 1 now +I have to multiply that by H H is 0.1 so + + align:start position:0% +I have to multiply that by H H is 0.1 so + + + align:start position:0% +I have to multiply that by H H is 0.1 so +it's minus sorry negative I'll never + + align:start position:0% +it's minus sorry negative I'll never + + + align:start position:0% +it's minus sorry negative I'll never +learn that + + align:start position:0% +learn that + + + align:start position:0% +learn that +the way you learn to talk in + + align:start position:0% +the way you learn to talk in + + + align:start position:0% +the way you learn to talk in +kindergarten is the way you learn to + + align:start position:0% +kindergarten is the way you learn to + + + align:start position:0% +kindergarten is the way you learn to +talk the rest of your life + + align:start position:0% +talk the rest of your life + + + align:start position:0% +talk the rest of your life +unfortunately uh kindergarten we said + + align:start position:0% +unfortunately uh kindergarten we said + + + align:start position:0% +unfortunately uh kindergarten we said +minus uh Sor negative + + align:start position:0% +minus uh Sor negative + + + align:start position:0% +minus uh Sor negative +.1 + + align:start position:0% + + + + align:start position:0% + +uh n is one now what's the value of xn + + align:start position:0% +uh n is one now what's the value of xn + + + align:start position:0% +uh n is one now what's the value of xn +well to the old one I add + + align:start position:0% +well to the old one I add + + + align:start position:0% +well to the old one I add +on10th what's the value of y well at + + align:start position:0% +on10th what's the value of y well at + + + align:start position:0% +on10th what's the value of y well at +this point you have to do the + + align:start position:0% +this point you have to do the + + + align:start position:0% +this point you have to do the +calculation it's the old value of y to + + align:start position:0% +calculation it's the old value of y to + + + align:start position:0% +calculation it's the old value of y to +get this new value it's the old Value + + align:start position:0% +get this new value it's the old Value + + + align:start position:0% +get this new value it's the old Value +Plus this number well that's this plus + + align:start position:0% +Plus this number well that's this plus + + + align:start position:0% +Plus this number well that's this plus +that number is + + align:start position:0% + + + + align:start position:0% + +9/10 a n now I have to calculate the new + + align:start position:0% +9/10 a n now I have to calculate the new + + + align:start position:0% +9/10 a n now I have to calculate the new +slope at this point okay that is one10 + + align:start position:0% +slope at this point okay that is one10 + + + align:start position:0% +slope at this point okay that is one10 +squared - 910 squared Gul that's + + align:start position:0% +squared - 910 squared Gul that's + + + align:start position:0% +squared - 910 squared Gul that's +0.001 minus + + align:start position:0% +0.001 minus + + + align:start position:0% +0.001 minus +81 which makes + + align:start position:0% +81 which makes + + + align:start position:0% +81 which makes +minus80 I + + align:start position:0% + + + + align:start position:0% + +hope check it on your calculators uh + + align:start position:0% +hope check it on your calculators uh + + + align:start position:0% +hope check it on your calculators uh +whip them out and press the buttons uh I + + align:start position:0% +whip them out and press the buttons uh I + + + align:start position:0% +whip them out and press the buttons uh I +now multiply that by H and which means + + align:start position:0% +now multiply that by H and which means + + + align:start position:0% +now multiply that by H and which means +it's going to be minus + + align:start position:0% + + + + align:start position:0% + +.08 uh perhaps with a zero after I + + align:start position:0% +.08 uh perhaps with a zero after I + + + align:start position:0% +.08 uh perhaps with a zero after I +didn't tell you how many decimal places + + align:start position:0% +didn't tell you how many decimal places + + + align:start position:0% +didn't tell you how many decimal places +let's carry it out to two decimal places + + align:start position:0% +let's carry it out to two decimal places + + + align:start position:0% +let's carry it out to two decimal places +I think uh that'll be uh good + + align:start position:0% +I think uh that'll be uh good + + + align:start position:0% +I think uh that'll be uh good +enough and finally the last step two + + align:start position:0% +enough and finally the last step two + + + align:start position:0% +enough and finally the last step two +here add one add another one10 so the + + align:start position:0% +here add one add another one10 so the + + + align:start position:0% +here add one add another one10 so the +value of x is now 210 and finally what's + + align:start position:0% +value of x is now 210 and finally what's + + + align:start position:0% +value of x is now 210 and finally what's +the value of y well I didn't tell you + + align:start position:0% +the value of y well I didn't tell you + + + align:start position:0% +the value of y well I didn't tell you +where to stop let's stop at y of Point + + align:start position:0% +where to stop let's stop at y of Point + + + align:start position:0% +where to stop let's stop at y of Point +let's stop at y of point2 because + + align:start position:0% +let's stop at y of point2 because + + + align:start position:0% +let's stop at y of point2 because +there's no more room on the Blackboard + + align:start position:0% +there's no more room on the Blackboard + + + align:start position:0% +there's no more room on the Blackboard +seems like an + + align:start position:0% +seems like an + + + align:start position:0% +seems like an +excellent about approximately how big is + + align:start position:0% +excellent about approximately how big is + + + align:start position:0% +excellent about approximately how big is +that in other words then uh this is + + align:start position:0% +that in other words then uh this is + + + align:start position:0% +that in other words then uh this is +going to + + align:start position:0% +going to + + + align:start position:0% +going to +be + + align:start position:0% +be + + + align:start position:0% +be +uh this uh the old y uh plus this number + + align:start position:0% +uh this uh the old y uh plus this number + + + align:start position:0% +uh this uh the old y uh plus this number +which seems to be0 82 to + + align:start position:0% + + + + align:start position:0% + +me so the answer is the new value is + + align:start position:0% +me so the answer is the new value is + + + align:start position:0% +me so the answer is the new value is +82 okay well we got a number we did what + + align:start position:0% +82 okay well we got a number we did what + + + align:start position:0% +82 okay well we got a number we did what +we were supposed to do we got a number + + align:start position:0% +we were supposed to do we got a number + + + align:start position:0% +we were supposed to do we got a number +next question well now let's ask a few + + align:start position:0% +next question well now let's ask a few + + + align:start position:0% +next question well now let's ask a few +questions one of the first most basic + + align:start position:0% +questions one of the first most basic + + + align:start position:0% +questions one of the first most basic +thing is you know how right is + + align:start position:0% + + + + align:start position:0% + +this how can I answer such a question if + + align:start position:0% +this how can I answer such a question if + + + align:start position:0% +this how can I answer such a question if +I can't calc if I have no explicit + + align:start position:0% +I can't calc if I have no explicit + + + align:start position:0% +I can't calc if I have no explicit +formula for that Solution that's the + + align:start position:0% +formula for that Solution that's the + + + align:start position:0% +formula for that Solution that's the +basic problem with numerical + + align:start position:0% +basic problem with numerical + + + align:start position:0% +basic problem with numerical +calculation in other words I have to + + align:start position:0% +calculation in other words I have to + + + align:start position:0% +calculation in other words I have to +wander around in the dark to some extent + + align:start position:0% +wander around in the dark to some extent + + + align:start position:0% +wander around in the dark to some extent +and yet have some idea when I've arrived + + align:start position:0% +and yet have some idea when I've arrived + + + align:start position:0% +and yet have some idea when I've arrived +at the place that I want to + + align:start position:0% +at the place that I want to + + + align:start position:0% +at the place that I want to +go well the first question I'd like to + + align:start position:0% +go well the first question I'd like to + + + align:start position:0% +go well the first question I'd like to +answer + + align:start position:0% +answer + + + align:start position:0% +answer +question is is this too high or too low + + align:start position:0% +question is is this too high or too low + + + align:start position:0% +question is is this too high or too low +is + + align:start position:0% +is + + + align:start position:0% +is +Oiler sorry he will forgive me in heaven + + align:start position:0% +Oiler sorry he will forgive me in heaven + + + align:start position:0% +Oiler sorry he will forgive me in heaven +I will use him by this I mean is the + + align:start position:0% +I will use him by this I mean is the + + + align:start position:0% +I will use him by this I mean is the +result well let me say something first + + align:start position:0% +result well let me say something first + + + align:start position:0% +result well let me say something first +and then I'll criticize it uh is Oiler + + align:start position:0% +and then I'll criticize it uh is Oiler + + + align:start position:0% +and then I'll criticize it uh is Oiler +too high or too + + align:start position:0% + + + + align:start position:0% + +low in other words is the result of + + align:start position:0% +low in other words is the result of + + + align:start position:0% +low in other words is the result of +using Oilers method I.E is this number + + align:start position:0% +using Oilers method I.E is this number + + + align:start position:0% +using Oilers method I.E is this number +too high or too low is it higher than + + align:start position:0% +too high or too low is it higher than + + + align:start position:0% +too high or too low is it higher than +the right answer what it should be or is + + align:start position:0% +the right answer what it should be or is + + + align:start position:0% +the right answer what it should be or is +it lower than the right answer or God + + align:start position:0% +it lower than the right answer or God + + + align:start position:0% +it lower than the right answer or God +forbid is it exactly right uh it's + + align:start position:0% +forbid is it exactly right uh it's + + + align:start position:0% +forbid is it exactly right uh it's +almost never exactly right that's not an + + align:start position:0% +almost never exactly right that's not an + + + align:start position:0% +almost never exactly right that's not an +option + + align:start position:0% +option + + + align:start position:0% +option +um how will we answer that question well + + align:start position:0% +um how will we answer that question well + + + align:start position:0% +um how will we answer that question well +let's answer it geometrically + + align:start position:0% +let's answer it geometrically + + + align:start position:0% +let's answer it geometrically +if basically if the solution were a line + + align:start position:0% +if basically if the solution were a line + + + align:start position:0% +if basically if the solution were a line +were a straight line then the oiler + + align:start position:0% +were a straight line then the oiler + + + align:start position:0% +were a straight line then the oiler +method would be exactly right all the + + align:start position:0% +method would be exactly right all the + + + align:start position:0% +method would be exactly right all the +time + + align:start position:0% + + + + align:start position:0% + +but it's not a line then it's a it's a + + align:start position:0% +but it's not a line then it's a it's a + + + align:start position:0% +but it's not a line then it's a it's a +curve well the critical question is is + + align:start position:0% +curve well the critical question is is + + + align:start position:0% +curve well the critical question is is +it curved is the solution so here's the + + align:start position:0% +it curved is the solution so here's the + + + align:start position:0% +it curved is the solution so here's the +solution let's call it y1 of X and let's + + align:start position:0% +solution let's call it y1 of X and let's + + + align:start position:0% +solution let's call it y1 of X and let's +say here was the starting point here the + + align:start position:0% +say here was the starting point here the + + + align:start position:0% +say here was the starting point here the +solution is + + align:start position:0% + + + + align:start position:0% + +convex and here the solution is + + align:start position:0% + + + + align:start position:0% + +concave right a concave up a concave + + align:start position:0% +concave right a concave up a concave + + + align:start position:0% +concave right a concave up a concave +down if you learn those words I think + + align:start position:0% +down if you learn those words I think + + + align:start position:0% +down if you learn those words I think +those have by now pretty I hope pretty + + align:start position:0% +those have by now pretty I hope pretty + + + align:start position:0% +those have by now pretty I hope pretty +well disappeared from the curriculum uh + + align:start position:0% +well disappeared from the curriculum uh + + + align:start position:0% +well disappeared from the curriculum uh +call it if you haven't up till now what + + align:start position:0% +call it if you haven't up till now what + + + align:start position:0% +call it if you haven't up till now what +mathematicians call it convex is that + + align:start position:0% +mathematicians call it convex is that + + + align:start position:0% +mathematicians call it convex is that +and the other one is + + align:start position:0% +and the other one is + + + align:start position:0% +and the other one is +concave uh well how do the oiler + + align:start position:0% +concave uh well how do the oiler + + + align:start position:0% +concave uh well how do the oiler +Solutions look well I'll just sketch I + + align:start position:0% +Solutions look well I'll just sketch I + + + align:start position:0% +Solutions look well I'll just sketch I +think from this you can see already when + + align:start position:0% +think from this you can see already when + + + align:start position:0% +think from this you can see already when +you start out on the oiler solution it's + + align:start position:0% +you start out on the oiler solution it's + + + align:start position:0% +you start out on the oiler solution it's +going to go like that now you're too low + + align:start position:0% +going to go like that now you're too low + + + align:start position:0% +going to go like that now you're too low +well let's suppose after that it the + + align:start position:0% +well let's suppose after that it the + + + align:start position:0% +well let's suppose after that it the +line element here is approximately the + + align:start position:0% +line element here is approximately the + + + align:start position:0% +line element here is approximately the +same as what it is there you know + + align:start position:0% +same as what it is there you know + + + align:start position:0% +same as what it is there you know +roughly parallel after all they're not + + align:start position:0% +roughly parallel after all they're not + + + align:start position:0% +roughly parallel after all they're not +too far apart and the direction field is + + align:start position:0% +too far apart and the direction field is + + + align:start position:0% +too far apart and the direction field is +continuous that is the directions don't + + align:start position:0% +continuous that is the directions don't + + + align:start position:0% +continuous that is the directions don't +change drastically from one point to + + align:start position:0% +change drastically from one point to + + + align:start position:0% +change drastically from one point to +another well then it'll sort of but now + + align:start position:0% +another well then it'll sort of but now + + + align:start position:0% +another well then it'll sort of but now +you see it's still too low it's even + + align:start position:0% +you see it's still too low it's even + + + align:start position:0% +you see it's still too low it's even +lower as it pathetically tries to follow + + align:start position:0% +lower as it pathetically tries to follow + + + align:start position:0% +lower as it pathetically tries to follow +its losing territory and that's + + align:start position:0% +its losing territory and that's + + + align:start position:0% +its losing territory and that's +basically because the curve is convex + + align:start position:0% +basically because the curve is convex + + + align:start position:0% +basically because the curve is convex +exactly the opposite would happen if the + + align:start position:0% +exactly the opposite would happen if the + + + align:start position:0% +exactly the opposite would happen if the +curve were concave if the solution curve + + align:start position:0% +curve were concave if the solution curve + + + align:start position:0% +curve were concave if the solution curve +or concave now it's too high and it's + + align:start position:0% +or concave now it's too high and it's + + + align:start position:0% +or concave now it's too high and it's +not going to be able to correct that as + + align:start position:0% +not going to be able to correct that as + + + align:start position:0% +not going to be able to correct that as +long as the solution curve stays con con + + align:start position:0% +long as the solution curve stays con con + + + align:start position:0% +long as the solution curve stays con con +concave well that's probably too + + align:start position:0% +concave well that's probably too + + + align:start position:0% +concave well that's probably too +optimistic it's probably more like + + align:start position:0% +optimistic it's probably more like + + + align:start position:0% +optimistic it's probably more like +this so in other words in this case if + + align:start position:0% +this so in other words in this case if + + + align:start position:0% +this so in other words in this case if +the curve is convex the oiler is going + + align:start position:0% +the curve is convex the oiler is going + + + align:start position:0% +the curve is convex the oiler is going +to be too high H sorry too + + align:start position:0% + + + + align:start position:0% + +low let's put E for Oiler how about that + + align:start position:0% +low let's put E for Oiler how about that + + + align:start position:0% +low let's put E for Oiler how about that +Oiler is too low if it's concave then + + align:start position:0% +Oiler is too low if it's concave then + + + align:start position:0% +Oiler is too low if it's concave then +Oiler is too + + align:start position:0% +Oiler is too + + + align:start position:0% +Oiler is too +high okay that's + + align:start position:0% +high okay that's + + + align:start position:0% +high okay that's +great uh there's just one little problem + + align:start position:0% +great uh there's just one little problem + + + align:start position:0% +great uh there's just one little problem +left namely if we don't have a formula + + align:start position:0% +left namely if we don't have a formula + + + align:start position:0% +left namely if we don't have a formula +for the solution and we don't have a + + align:start position:0% +for the solution and we don't have a + + + align:start position:0% +for the solution and we don't have a +computer that's busy drawing the picture + + align:start position:0% +computer that's busy drawing the picture + + + align:start position:0% +computer that's busy drawing the picture +for us in which case we wouldn't need + + align:start position:0% +for us in which case we wouldn't need + + + align:start position:0% +for us in which case we wouldn't need +any of this anyway uh how are we + + align:start position:0% +any of this anyway uh how are we + + + align:start position:0% +any of this anyway uh how are we +supposed to tell if it's convex or + + align:start position:0% +supposed to tell if it's convex or + + + align:start position:0% +supposed to tell if it's convex or +concave + + align:start position:0% + + + + align:start position:0% + +ah back to calculus calculus to the + + align:start position:0% +ah back to calculus calculus to the + + + align:start position:0% +ah back to calculus calculus to the +rescue when is it a curve convex a curve + + align:start position:0% +rescue when is it a curve convex a curve + + + align:start position:0% +rescue when is it a curve convex a curve +is convex if its second derivative + + align:start position:0% + + + + align:start position:0% + +is positive because the first to be + + align:start position:0% +is positive because the first to be + + + align:start position:0% +is positive because the first to be +convex means the first derivative is + + align:start position:0% +convex means the first derivative is + + + align:start position:0% +convex means the first derivative is +increasing all the time and therefore + + align:start position:0% +increasing all the time and therefore + + + align:start position:0% +increasing all the time and therefore +the second derivative which is the + + align:start position:0% +the second derivative which is the + + + align:start position:0% +the second derivative which is the +derivative of the first derivative + + align:start position:0% +derivative of the first derivative + + + align:start position:0% +derivative of the first derivative +should be positive just the opposite + + align:start position:0% +should be positive just the opposite + + + align:start position:0% +should be positive just the opposite +here the Curve the slope is the first + + align:start position:0% +here the Curve the slope is the first + + + align:start position:0% +here the Curve the slope is the first +derivative is decreasing all the time + + align:start position:0% +derivative is decreasing all the time + + + align:start position:0% +derivative is decreasing all the time +and therefore the second derivative is + + align:start position:0% +and therefore the second derivative is + + + align:start position:0% +and therefore the second derivative is +negative so all we have to do is decide + + align:start position:0% +negative so all we have to do is decide + + + align:start position:0% +negative so all we have to do is decide +what the first and SEC what the + + align:start position:0% +what the first and SEC what the + + + align:start position:0% +what the first and SEC what the +derivative the second derivative of this + + align:start position:0% +derivative the second derivative of this + + + align:start position:0% +derivative the second derivative of this +solution is let's we should probably + + align:start position:0% +solution is let's we should probably + + + align:start position:0% +solution is let's we should probably +call it a solution to Y of X is a little + + align:start position:0% +call it a solution to Y of X is a little + + + align:start position:0% +call it a solution to Y of X is a little +too vague y1 means the solution that's + + align:start position:0% +too vague y1 means the solution that's + + + align:start position:0% +too vague y1 means the solution that's +started at this point so in fact + + align:start position:0% +started at this point so in fact + + + align:start position:0% +started at this point so in fact +probably it would have been better from + + align:start position:0% +probably it would have been better from + + + align:start position:0% +probably it would have been better from +the beginning to call that y1 except + + align:start position:0% +the beginning to call that y1 except + + + align:start position:0% +the beginning to call that y1 except +there's no + + align:start position:0% +there's no + + + align:start position:0% +there's no +room y1 left say that means the solution + + align:start position:0% +room y1 left say that means the solution + + + align:start position:0% +room y1 left say that means the solution +which started out at the0 01 so I'm + + align:start position:0% +which started out at the0 01 so I'm + + + align:start position:0% +which started out at the0 01 so I'm +still talking about a solution like that + + align:start position:0% +still talking about a solution like that + + + align:start position:0% +still talking about a solution like that +all right so I want to know if this is + + align:start position:0% +all right so I want to know if this is + + + align:start position:0% +all right so I want to know if this is +positive the second derivative is + + align:start position:0% +positive the second derivative is + + + align:start position:0% +positive the second derivative is +positive at the starting point zero or + + align:start position:0% +positive at the starting point zero or + + + align:start position:0% +positive at the starting point zero or +it's negative now again how do you + + align:start position:0% +it's negative now again how do you + + + align:start position:0% +it's negative now again how do you +calculate the second derivative if you + + align:start position:0% +calculate the second derivative if you + + + align:start position:0% +calculate the second derivative if you +can't even if you don't know what the + + align:start position:0% +can't even if you don't know what the + + + align:start position:0% +can't even if you don't know what the +solution is explicitly and the answer is + + align:start position:0% +solution is explicitly and the answer is + + + align:start position:0% +solution is explicitly and the answer is +you can do it from the differential + + align:start position:0% +you can do it from the differential + + + align:start position:0% +you can do it from the differential +equation + + align:start position:0% + + + + align:start position:0% + +itself how do I do that well easy y + + align:start position:0% +itself how do I do that well easy y + + + align:start position:0% +itself how do I do that well easy y +Prime = x^2 - y^2 okay that tells me how + + align:start position:0% +Prime = x^2 - y^2 okay that tells me how + + + align:start position:0% +Prime = x^2 - y^2 okay that tells me how +to calculate y Prime if I know the value + + align:start position:0% +to calculate y Prime if I know the value + + + align:start position:0% +to calculate y Prime if I know the value +of x and y in other words the 0 Z1 what + + align:start position:0% +of x and y in other words the 0 Z1 what + + + align:start position:0% +of x and y in other words the 0 Z1 what +would be the value of y double Prime + + align:start position:0% +would be the value of y double Prime + + + align:start position:0% +would be the value of y double Prime +well differentiate the equation it's 2x + + align:start position:0% +well differentiate the equation it's 2x + + + align:start position:0% +well differentiate the equation it's 2x +- 2 y y Prime don't forget to use the + + align:start position:0% +- 2 y y Prime don't forget to use the + + + align:start position:0% +- 2 y y Prime don't forget to use the +chain + + align:start position:0% +chain + + + align:start position:0% +chain +rule so if I want to calculate at 01 + + align:start position:0% + + + + align:start position:0% + +in other words at my starting point is + + align:start position:0% +in other words at my starting point is + + + align:start position:0% +in other words at my starting point is +that curve convex or concave well let's + + align:start position:0% +that curve convex or concave well let's + + + align:start position:0% +that curve convex or concave well let's +calculate y of 0 equals + + align:start position:0% +calculate y of 0 equals + + + align:start position:0% +calculate y of 0 equals +1 okay what's y Prime of 0 well I don't + + align:start position:0% +1 okay what's y Prime of 0 well I don't + + + align:start position:0% +1 okay what's y Prime of 0 well I don't +have to repeat that calculation using + + align:start position:0% +have to repeat that calculation using + + + align:start position:0% +have to repeat that calculation using +this I already calculated that it was + + align:start position:0% +this I already calculated that it was + + + align:start position:0% +this I already calculated that it was +negative + + align:start position:0% +negative + + + align:start position:0% +negative +one and now the new thing is what's y + + align:start position:0% +one and now the new thing is what's y + + + align:start position:0% +one and now the new thing is what's y +double Prime of zero well it is this it + + align:start position:0% +double Prime of zero well it is this it + + + align:start position:0% +double Prime of zero well it is this it +is I'll write it out it's 2 * 0 0 - 2 + + align:start position:0% +is I'll write it out it's 2 * 0 0 - 2 + + + align:start position:0% +is I'll write it out it's 2 * 0 0 - 2 +* Nega uh Y which is 1 2 * 1 * y Prime + + align:start position:0% +* Nega uh Y which is 1 2 * 1 * y Prime + + + align:start position:0% +* Nega uh Y which is 1 2 * 1 * y Prime +which is negative 1 you you want to see + + align:start position:0% +which is negative 1 you you want to see + + + align:start position:0% +which is negative 1 you you want to see +we're pulling ourselves up our own + + align:start position:0% +we're pulling ourselves up our own + + + align:start position:0% +we're pulling ourselves up our own +bootstraps which is impossible but it is + + align:start position:0% +bootstraps which is impossible but it is + + + align:start position:0% +bootstraps which is impossible but it is +not impossible because we're doing it uh + + align:start position:0% +not impossible because we're doing it uh + + + align:start position:0% +not impossible because we're doing it uh +so so what's the answer zero here two + + align:start position:0% +so so what's the answer zero here two + + + align:start position:0% +so so what's the answer zero here two +I've calculated without having the + + align:start position:0% +I've calculated without having the + + + align:start position:0% +I've calculated without having the +foggiest idea of what the solution is is + + align:start position:0% +foggiest idea of what the solution is is + + + align:start position:0% +foggiest idea of what the solution is is +how it looks I've calculated that its + + align:start position:0% +how it looks I've calculated that its + + + align:start position:0% +how it looks I've calculated that its +second derivative at the starting point + + align:start position:0% +second derivative at the starting point + + + align:start position:0% +second derivative at the starting point +is two therefore my solution is convex + + align:start position:0% +is two therefore my solution is convex + + + align:start position:0% +is two therefore my solution is convex +at the starting point and therefore this + + align:start position:0% +at the starting point and therefore this + + + align:start position:0% +at the starting point and therefore this +Oiler approximation if I don't carry it + + align:start position:0% +Oiler approximation if I don't carry it + + + align:start position:0% +Oiler approximation if I don't carry it +out too far will be too low so it's + + align:start position:0% +out too far will be too low so it's + + + align:start position:0% +out too far will be too low so it's +convex Oiler too + + align:start position:0% + + + + align:start position:0% + +low now you could argue yeah well what + + align:start position:0% +low now you could argue yeah well what + + + align:start position:0% +low now you could argue yeah well what +about this uh you + + align:start position:0% +about this uh you + + + align:start position:0% +about this uh you +know suppose + + align:start position:0% +know suppose + + + align:start position:0% +know suppose +it you know + + align:start position:0% +it you know + + + align:start position:0% +it you know +yeah so you go like this and then then + + align:start position:0% +yeah so you go like this and then then + + + align:start position:0% +yeah so you go like this and then then +but then it uh see it catches up and + + align:start position:0% +but then it uh see it catches up and + + + align:start position:0% +but then it uh see it catches up and +then so well of course if the curve + + align:start position:0% +then so well of course if the curve + + + align:start position:0% +then so well of course if the curve +changes from convex to concave then then + + align:start position:0% +changes from convex to concave then then + + + align:start position:0% +changes from convex to concave then then +it's really impossible to make any + + align:start position:0% +it's really impossible to make any + + + align:start position:0% +it's really impossible to make any +prediction at all uh that's a difficulty + + align:start position:0% +prediction at all uh that's a difficulty + + + align:start position:0% +prediction at all uh that's a difficulty +uh so all this analysis is only if you + + align:start position:0% +uh so all this analysis is only if you + + + align:start position:0% +uh so all this analysis is only if you +stay stay very + + align:start position:0% +stay stay very + + + align:start position:0% +stay stay very +nearby uh however I wanted to show you + + align:start position:0% +nearby uh however I wanted to show you + + + align:start position:0% +nearby uh however I wanted to show you +uh the main purpose of it in my mind was + + align:start position:0% +uh the main purpose of it in my mind was + + + align:start position:0% +uh the main purpose of it in my mind was +to show you how to use the diff it's + + align:start position:0% +to show you how to use the diff it's + + + align:start position:0% +to show you how to use the diff it's +these equations how to use the + + align:start position:0% +these equations how to use the + + + align:start position:0% +these equations how to use the +differential equation itself to get + + align:start position:0% +differential equation itself to get + + + align:start position:0% +differential equation itself to get +information about the solutions without + + align:start position:0% +information about the solutions without + + + align:start position:0% +information about the solutions without +actually being able to calculate the + + align:start position:0% + + + + align:start position:0% + +solutions now so that's the method and + + align:start position:0% +solutions now so that's the method and + + + align:start position:0% +solutions now so that's the method and +that's how to find out something about + + align:start position:0% +that's how to find out something about + + + align:start position:0% +that's how to find out something about +it and now what I'd like to talk talk + + align:start position:0% +it and now what I'd like to talk talk + + + align:start position:0% +it and now what I'd like to talk talk +about is + + align:start position:0% +about is + + + align:start position:0% +about is +errors how do I handle + + align:start position:0% +errors how do I handle + + + align:start position:0% +errors how do I handle +uh + + align:start position:0% + + + + align:start position:0% + +oh right so I mean that's an anal in a + + align:start position:0% +oh right so I mean that's an anal in a + + + align:start position:0% +oh right so I mean that's an anal in a +sense I've started the error analysis in + + align:start position:0% +sense I've started the error analysis in + + + align:start position:0% +sense I've started the error analysis in +other words the error by definition the + + align:start position:0% +other words the error by definition the + + + align:start position:0% +other words the error by definition the +error is this difference e the error so + + align:start position:0% +error is this difference e the error so + + + align:start position:0% +error is this difference e the error so +in other words I'm asking here is the + + align:start position:0% +in other words I'm asking here is the + + + align:start position:0% +in other words I'm asking here is the +error + + align:start position:0% +error + + + align:start position:0% +error +positive as it would be uh it's depends + + align:start position:0% +positive as it would be uh it's depends + + + align:start position:0% +positive as it would be uh it's depends +which way you measure it usually you + + align:start position:0% +which way you measure it usually you + + + align:start position:0% +which way you measure it usually you +take this minus that so here the + + align:start position:0% +take this minus that so here the + + + align:start position:0% +take this minus that so here the +error the error would be considered + + align:start position:0% +error the error would be considered + + + align:start position:0% +error the error would be considered +positive and here it would be considered + + align:start position:0% +positive and here it would be considered + + + align:start position:0% +positive and here it would be considered +negative although I'm sure there's a + + align:start position:0% +negative although I'm sure there's a + + + align:start position:0% +negative although I'm sure there's a +book somewhere in the world which does + + align:start position:0% +book somewhere in the world which does + + + align:start position:0% +book somewhere in the world which does +the opposite uh most hedge by just using + + align:start position:0% +the opposite uh most hedge by just using + + + align:start position:0% +the opposite uh most hedge by just using +the absolute value of the + + align:start position:0% +the absolute value of the + + + align:start position:0% +the absolute value of the +error plus a statement that the method + + align:start position:0% +error plus a statement that the method + + + align:start position:0% +error plus a statement that the method +is producing answers which are too low + + align:start position:0% +is producing answers which are too low + + + align:start position:0% +is producing answers which are too low +or too + + align:start position:0% + + + + align:start position:0% + +high the question then is naturally + + align:start position:0% +high the question then is naturally + + + align:start position:0% +high the question then is naturally +this is not the world's best method it's + + align:start position:0% +this is not the world's best method it's + + + align:start position:0% +this is not the world's best method it's +not as bad as it seems It's not the + + align:start position:0% +not as bad as it seems It's not the + + + align:start position:0% +not as bad as it seems It's not the +world's best method because that + + align:start position:0% +world's best method because that + + + align:start position:0% +world's best method because that +convexity and concavity means that + + align:start position:0% +convexity and concavity means that + + + align:start position:0% +convexity and concavity means that +you're automatically IND introducing a + + align:start position:0% +you're automatically IND introducing a + + + align:start position:0% +you're automatically IND introducing a +systematic + + align:start position:0% +systematic + + + align:start position:0% +systematic +error if you can predict which way the + + align:start position:0% +error if you can predict which way the + + + align:start position:0% +error if you can predict which way the +error is going to be by just knowing if + + align:start position:0% +error is going to be by just knowing if + + + align:start position:0% +error is going to be by just knowing if +the curve is convex or concave then + + align:start position:0% +the curve is convex or concave then + + + align:start position:0% +the curve is convex or concave then +that's it's just it's not what you want + + align:start position:0% +that's it's just it's not what you want + + + align:start position:0% +that's it's just it's not what you want +I mean you want to at least have a + + align:start position:0% +I mean you want to at least have a + + + align:start position:0% +I mean you want to at least have a +chance of getting the right answer + + align:start position:0% +chance of getting the right answer + + + align:start position:0% +chance of getting the right answer +whereas this is telling you you're + + align:start position:0% +whereas this is telling you you're + + + align:start position:0% +whereas this is telling you you're +definitely going to get the wrong answer + + align:start position:0% +definitely going to get the wrong answer + + + align:start position:0% +definitely going to get the wrong answer +all it tells you is and it's telling you + + align:start position:0% +all it tells you is and it's telling you + + + align:start position:0% +all it tells you is and it's telling you +your answer is going to be too high or + + align:start position:0% +your answer is going to be too high or + + + align:start position:0% +your answer is going to be too high or +too low we'd like a better chance of + + align:start position:0% +too low we'd like a better chance of + + + align:start position:0% +too low we'd like a better chance of +getting the right answer + + align:start position:0% +getting the right answer + + + align:start position:0% +getting the right answer +now so the question is how do you get a + + align:start position:0% +now so the question is how do you get a + + + align:start position:0% +now so the question is how do you get a +better + + align:start position:0% + + + + align:start position:0% + +method a search is for a better + + align:start position:0% + + + + align:start position:0% + +method now + + align:start position:0% +method now + + + align:start position:0% +method now +the first method which will occur I'm + + align:start position:0% +the first method which will occur I'm + + + align:start position:0% +the first method which will occur I'm +sure to anyone who looks at that picture + + align:start position:0% +sure to anyone who looks at that picture + + + align:start position:0% +sure to anyone who looks at that picture +is look if you want this yellow line to + + align:start position:0% +is look if you want this yellow line to + + + align:start position:0% +is look if you want this yellow line to +follow the white + + align:start position:0% +follow the white + + + align:start position:0% +follow the white +one the white solution more accurately + + align:start position:0% +one the white solution more accurately + + + align:start position:0% +one the white solution more accurately +For Heaven's Sake don't take such big + + align:start position:0% +For Heaven's Sake don't take such big + + + align:start position:0% +For Heaven's Sake don't take such big +steps take small steps and then it will + + align:start position:0% +steps take small steps and then it will + + + align:start position:0% +steps take small steps and then it will +follow better all right let's draw a + + align:start position:0% +follow better all right let's draw a + + + align:start position:0% +follow better all right let's draw a +picture excuse me + + align:start position:0% + + + + align:start position:0% + +my little box of treasures + + align:start position:0% +my little box of treasures + + + align:start position:0% +my little box of treasures +here take any + + align:start position:0% + + + + align:start position:0% + +away so use a smaller step + + align:start position:0% + + + + align:start position:0% + +size and the picture roughly which is + + align:start position:0% +size and the picture roughly which is + + + align:start position:0% +size and the picture roughly which is +going to justify that will look like + + align:start position:0% +going to justify that will look like + + + align:start position:0% +going to justify that will look like +this uh if the solution curve looks like + + align:start position:0% +this uh if the solution curve looks like + + + align:start position:0% +this uh if the solution curve looks like +this then with a big step size I'm + + align:start position:0% +this then with a big step size I'm + + + align:start position:0% +this then with a big step size I'm +liable to have something that looks like + + align:start position:0% +liable to have something that looks like + + + align:start position:0% +liable to have something that looks like +that but if I take a smaller step size + + align:start position:0% +that but if I take a smaller step size + + + align:start position:0% +that but if I take a smaller step size +suppose I have the step size how is it + + align:start position:0% +suppose I have the step size how is it + + + align:start position:0% +suppose I have the step size how is it +going to look then well I better switch + + align:start position:0% +going to look then well I better switch + + + align:start position:0% +going to look then well I better switch +to a different color if I have the step + + align:start position:0% +to a different color if I have the step + + + align:start position:0% +to a different color if I have the step +size I'll get a a uh a little it goes + + align:start position:0% +size I'll get a a uh a little it goes + + + align:start position:0% +size I'll get a a uh a little it goes +like that and now it's following closer + + align:start position:0% +like that and now it's following closer + + + align:start position:0% +like that and now it's following closer +of course I'm stacking the deck but see + + align:start position:0% +of course I'm stacking the deck but see + + + align:start position:0% +of course I'm stacking the deck but see +how close it follows uh + + align:start position:0% +how close it follows uh + + + align:start position:0% +how close it follows uh +you know I'm definitely not to be + + align:start position:0% +you know I'm definitely not to be + + + align:start position:0% +you know I'm definitely not to be +trusted on this but uh there okay let's + + align:start position:0% +trusted on this but uh there okay let's + + + align:start position:0% +trusted on this but uh there okay let's +do the opposite make a really big steps + + align:start position:0% +do the opposite make a really big steps + + + align:start position:0% +do the opposite make a really big steps +suppose instead of the yellow one I'd + + align:start position:0% +suppose instead of the yellow one I'd + + + align:start position:0% +suppose instead of the yellow one I'd +used the green one well a double step + + align:start position:0% +used the green one well a double step + + + align:start position:0% +used the green one well a double step +size well what would have happened then + + align:start position:0% +size well what would have happened then + + + align:start position:0% +size well what would have happened then +well I started out but now I've gone all + + align:start position:0% +well I started out but now I've gone all + + + align:start position:0% +well I started out but now I've gone all +the way to there and now on my way up of + + align:start position:0% +the way to there and now on my way up of + + + align:start position:0% +the way to there and now on my way up of +course it it has a little further to go + + align:start position:0% +course it it has a little further to go + + + align:start position:0% +course it it has a little further to go +but if for some reason I had stopped + + align:start position:0% +but if for some reason I had stopped + + + align:start position:0% +but if for some reason I had stopped +there you could see I would be still + + align:start position:0% +there you could see I would be still + + + align:start position:0% +there you could see I would be still +lower in other words the bigger the step + + align:start position:0% +lower in other words the bigger the step + + + align:start position:0% +lower in other words the bigger the step +size the the more the error and where + + align:start position:0% +size the the more the error and where + + + align:start position:0% +size the the more the error and where +are the errors that we're talking about + + align:start position:0% +are the errors that we're talking about + + + align:start position:0% +are the errors that we're talking about +well uh the way to think of the errors + + align:start position:0% +well uh the way to think of the errors + + + align:start position:0% +well uh the way to think of the errors +this is the + + align:start position:0% + + + + align:start position:0% + +error that number the error and you can + + align:start position:0% +error that number the error and you can + + + align:start position:0% +error that number the error and you can +make it a positive negative or just put + + align:start position:0% +make it a positive negative or just put + + + align:start position:0% +make it a positive negative or just put +an automatically an absolute value sign + + align:start position:0% +an automatically an absolute value sign + + + align:start position:0% +an automatically an absolute value sign +around it that's not so + + align:start position:0% +around it that's not so + + + align:start position:0% +around it that's not so +important so in other words the + + align:start position:0% +important so in other words the + + + align:start position:0% +important so in other words the +conclusion is that the error that the + + align:start position:0% +conclusion is that the error that the + + + align:start position:0% +conclusion is that the error that the +error E the difference between the True + + align:start position:0% +error E the difference between the True + + + align:start position:0% +error E the difference between the True +Value that I should have gotten the + + align:start position:0% +Value that I should have gotten the + + + align:start position:0% +Value that I should have gotten the +oiler value that the calculation + + align:start position:0% +oiler value that the calculation + + + align:start position:0% +oiler value that the calculation +produced the the error E depends on the + + align:start position:0% +produced the the error E depends on the + + + align:start position:0% +produced the the error E depends on the +step + + align:start position:0% + + + + align:start position:0% + +size now how does it depend on the step + + align:start position:0% +size now how does it depend on the step + + + align:start position:0% +size now how does it depend on the step +size well it's impossible to give an + + align:start position:0% +size well it's impossible to give an + + + align:start position:0% +size well it's impossible to give an +exact formula but there's an approximate + + align:start position:0% +exact formula but there's an approximate + + + align:start position:0% +exact formula but there's an approximate +answer which is by and large true and uh + + align:start position:0% +answer which is by and large true and uh + + + align:start position:0% +answer which is by and large true and uh +the answer is so e is going to be a + + align:start position:0% +the answer is so e is going to be a + + + align:start position:0% +the answer is so e is going to be a +function of H what function well + + align:start position:0% +function of H what function well + + + align:start position:0% +function of H what function well +asymptotically which means is another + + align:start position:0% +asymptotically which means is another + + + align:start position:0% +asymptotically which means is another +way of putting quotation marks uh around + + align:start position:0% +way of putting quotation marks uh around + + + align:start position:0% +way of putting quotation marks uh around +what do I say it's going to be a + + align:start position:0% +what do I say it's going to be a + + + align:start position:0% +what do I say it's going to be a +constant some constant times + + align:start position:0% +constant some constant times + + + align:start position:0% +constant some constant times +H late you pretty + + align:start position:0% + + + + align:start position:0% + +boy nobody right + + align:start position:0% + + + + align:start position:0% + +there it looks like this and for this + + align:start position:0% +there it looks like this and for this + + + align:start position:0% +there it looks like this and for this +reason it's called a uh first + + align:start position:0% +reason it's called a uh first + + + align:start position:0% +reason it's called a uh first +order the oiler is a first order method + + align:start position:0% +order the oiler is a first order method + + + align:start position:0% +order the oiler is a first order method +and now first + + align:start position:0% + + + + align:start position:0% + +order does not refer to the first order + + align:start position:0% +order does not refer to the first order + + + align:start position:0% +order does not refer to the first order +of the differential equation it's not + + align:start position:0% +of the differential equation it's not + + + align:start position:0% +of the differential equation it's not +that use of the word first it's not the + + align:start position:0% +that use of the word first it's not the + + + align:start position:0% +that use of the word first it's not the +first order because it's y Prime equals + + align:start position:0% +first order because it's y Prime equals + + + align:start position:0% +first order because it's y Prime equals +f ofx y the first order means the fact + + align:start position:0% +f ofx y the first order means the fact + + + align:start position:0% +f ofx y the first order means the fact +that H occurs to the first + + align:start position:0% +that H occurs to the first + + + align:start position:0% +that H occurs to the first +Power the way people usually say this + + align:start position:0% +Power the way people usually say this + + + align:start position:0% +Power the way people usually say this +is since the normal way of decreasing + + align:start position:0% +is since the normal way of decreasing + + + align:start position:0% +is since the normal way of decreasing +the step size as you'll see as soon as + + align:start position:0% +the step size as you'll see as soon as + + + align:start position:0% +the step size as you'll see as soon as +you try to use the computer visual that + + align:start position:0% +you try to use the computer visual that + + + align:start position:0% +you try to use the computer visual that +deals with Oiler method which I highly + + align:start position:0% +deals with Oiler method which I highly + + + align:start position:0% +deals with Oiler method which I highly +recommend by the way so highly + + align:start position:0% +recommend by the way so highly + + + align:start position:0% +recommend by the way so highly +recommended that you have to do + + align:start position:0% +recommended that you have to do + + + align:start position:0% +recommended that you have to do +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +is is + + align:start position:0% +is is + + + align:start position:0% +is is +that the way to say it that since you + + align:start position:0% +that the way to say it that since you + + + align:start position:0% +that the way to say it that since you +con each new Step hases the step size + + align:start position:0% +con each new Step hases the step size + + + align:start position:0% +con each new Step hases the step size +that's the usual way to do it uh if you + + align:start position:0% +that's the usual way to do it uh if you + + + align:start position:0% +that's the usual way to do it uh if you +have the step + + align:start position:0% + + + + align:start position:0% + +size since this is a constant if I have + + align:start position:0% +size since this is a constant if I have + + + align:start position:0% +size since this is a constant if I have +the step size I have the eror + + align:start position:0% + + + + align:start position:0% + +approximately have the step size have + + align:start position:0% +approximately have the step size have + + + align:start position:0% +approximately have the step size have +the error that tells you how the error + + align:start position:0% +the error that tells you how the error + + + align:start position:0% +the error that tells you how the error +varies with step size for Oilers + + align:start position:0% +varies with step size for Oilers + + + align:start position:0% +varies with step size for Oilers +method + + align:start position:0% + + + + align:start position:0% + +uh uh please understand that's what + + align:start position:0% +uh uh please understand that's what + + + align:start position:0% +uh uh please understand that's what +people say and please understand the + + align:start position:0% +people say and please understand the + + + align:start position:0% +people say and please understand the +grammatical construction + + align:start position:0% +grammatical construction + + + align:start position:0% +grammatical construction +uh since everyone the math department + + align:start position:0% +uh since everyone the math department + + + align:start position:0% +uh since everyone the math department +has a cold these days except me for the + + align:start position:0% +has a cold these days except me for the + + + align:start position:0% +has a cold these days except me for the +moment + + align:start position:0% + + + + align:start position:0% + +uh everyone goes around chanting this + + align:start position:0% +uh everyone goes around chanting this + + + align:start position:0% +uh everyone goes around chanting this +Mantra this is totally irrelevant + + align:start position:0% +Mantra this is totally irrelevant + + + align:start position:0% +Mantra this is totally irrelevant +uh total Mantra uh you know feed a cold + + align:start position:0% +uh total Mantra uh you know feed a cold + + + align:start position:0% +uh total Mantra uh you know feed a cold +starve a + + align:start position:0% + + + + align:start position:0% + +fever and if you ask them what it means + + align:start position:0% +fever and if you ask them what it means + + + align:start position:0% +fever and if you ask them what it means +they say it means you know eat a lot if + + align:start position:0% +they say it means you know eat a lot if + + + align:start position:0% +they say it means you know eat a lot if +you have a cold and if you have a fever + + align:start position:0% +you have a cold and if you have a fever + + + align:start position:0% +you have a cold and if you have a fever +don't eat very much + + align:start position:0% +don't eat very much + + + align:start position:0% +don't eat very much +which is not what it means at all + + align:start position:0% +which is not what it means at all + + + align:start position:0% +which is not what it means at all +grammatically it's exactly the same + + align:start position:0% +grammatically it's exactly the same + + + align:start position:0% +grammatically it's exactly the same +construction as + + align:start position:0% +construction as + + + align:start position:0% +construction as +this have the what this means is if you + + align:start position:0% +this have the what this means is if you + + + align:start position:0% +this have the what this means is if you +have the step size you will have the + + align:start position:0% +have the step size you will have the + + + align:start position:0% +have the step size you will have the +error and that's what feed a cold starve + + align:start position:0% +error and that's what feed a cold starve + + + align:start position:0% +error and that's what feed a cold starve +a fever means and remember this for the + + align:start position:0% +a fever means and remember this for the + + + align:start position:0% +a fever means and remember this for the +rest of your life if you feed a cold if + + align:start position:0% +rest of your life if you feed a cold if + + + align:start position:0% +rest of your life if you feed a cold if +you eat too much when you have a cold + + align:start position:0% +you eat too much when you have a cold + + + align:start position:0% +you eat too much when you have a cold +you will get a fever and end up St + + align:start position:0% +you will get a fever and end up St + + + align:start position:0% +you will get a fever and end up St +having to starve starve yourself because + + align:start position:0% +having to starve starve yourself because + + + align:start position:0% +having to starve starve yourself because +of course nobody when you have a fever + + align:start position:0% +of course nobody when you have a fever + + + align:start position:0% +of course nobody when you have a fever +nobody feels like eating so they don't + + align:start position:0% +nobody feels like eating so they don't + + + align:start position:0% +nobody feels like eating so they don't +eat + + align:start position:0% +eat + + + align:start position:0% +eat +anything all right you got that you got + + align:start position:0% +anything all right you got that you got + + + align:start position:0% +anything all right you got that you got +that + + align:start position:0% + + + + align:start position:0% + +good good + + align:start position:0% + + + + align:start position:0% + +go I want all of you to go home and tell + + align:start position:0% +go I want all of you to go home and tell + + + align:start position:0% +go I want all of you to go home and tell +that to your + + align:start position:0% + + + + align:start position:0% + +mothers you know that's the way we + + align:start position:0% +mothers you know that's the way we + + + align:start position:0% +mothers you know that's the way we +always used to speak back you know a + + align:start position:0% +always used to speak back you know a + + + align:start position:0% +always used to speak back you know a +Grimmer one spare the rod and spoil the + + align:start position:0% +Grimmer one spare the rod and spoil the + + + align:start position:0% +Grimmer one spare the rod and spoil the +child does not mean that you should not + + align:start position:0% +child does not mean that you should not + + + align:start position:0% +child does not mean that you should not +hit your kid and + + align:start position:0% +hit your kid and + + + align:start position:0% +hit your kid and +uh it means it means that if you fail to + + align:start position:0% +uh it means it means that if you fail to + + + align:start position:0% +uh it means it means that if you fail to +hit your kid uh he or she will be + + align:start position:0% +hit your kid uh he or she will be + + + align:start position:0% +hit your kid uh he or she will be +spoiled whatever that means uh so uh you + + align:start position:0% +spoiled whatever that means uh so uh you + + + align:start position:0% +spoiled whatever that means uh so uh you +don't want to you want to do with that + + align:start position:0% +don't want to you want to do with that + + + align:start position:0% +don't want to you want to do with that +the I guess the mantra today would be uh + + align:start position:0% +the I guess the mantra today would be uh + + + align:start position:0% +the I guess the mantra today would be uh +What + + align:start position:0% +What + + + align:start position:0% +What +uh I don't know + + align:start position:0% + + + + align:start position:0% + +okay so the first line of defense is + + align:start position:0% +okay so the first line of defense is + + + align:start position:0% +okay so the first line of defense is +simply to uh keep having the step size + + align:start position:0% +simply to uh keep having the step size + + + align:start position:0% +simply to uh keep having the step size +in Oiler and what people do is if they + + align:start position:0% +in Oiler and what people do is if they + + + align:start position:0% +in Oiler and what people do is if they +don't want to use anything better than + + align:start position:0% +don't want to use anything better than + + + align:start position:0% +don't want to use anything better than +Oilers method is you keep having the + + align:start position:0% +Oilers method is you keep having the + + + align:start position:0% +Oilers method is you keep having the +step size until the curve doesn't seem + + align:start position:0% +step size until the curve doesn't seem + + + align:start position:0% +step size until the curve doesn't seem +to change anymore and then you say well + + align:start position:0% +to change anymore and then you say well + + + align:start position:0% +to change anymore and then you say well +that must be the + + align:start position:0% +that must be the + + + align:start position:0% +that must be the +solution and I ask you on the problem + + align:start position:0% +solution and I ask you on the problem + + + align:start position:0% +solution and I ask you on the problem +set how much would you could continue to + + align:start position:0% +set how much would you could continue to + + + align:start position:0% +set how much would you could continue to +have to have the step size in order for + + align:start position:0% +have to have the step size in order for + + + align:start position:0% +have to have the step size in order for +that good thing to + + align:start position:0% +that good thing to + + + align:start position:0% +that good thing to +happen however there are more efficient + + align:start position:0% +happen however there are more efficient + + + align:start position:0% +happen however there are more efficient +methods which gets the result + + align:start position:0% +methods which gets the result + + + align:start position:0% +methods which gets the result +faster and so if that's our good method + + align:start position:0% +faster and so if that's our good method + + + align:start position:0% +faster and so if that's our good method +let's call this our a bet a still better + + align:start position:0% +let's call this our a bet a still better + + + align:start position:0% +let's call this our a bet a still better +method the better + + align:start position:0% +method the better + + + align:start position:0% +method the better +methods aim at being better they keep + + align:start position:0% +methods aim at being better they keep + + + align:start position:0% +methods aim at being better they keep +the same idea as Oilers method but they + + align:start position:0% +the same idea as Oilers method but they + + + align:start position:0% +the same idea as Oilers method but they +say look let's try to improve that slope + + align:start position:0% +say look let's try to improve that slope + + + align:start position:0% +say look let's try to improve that slope +a end in other words since the slope a n + + align:start position:0% +a end in other words since the slope a n + + + align:start position:0% +a end in other words since the slope a n +that we start with is guaranteed to be + + align:start position:0% +that we start with is guaranteed to be + + + align:start position:0% +that we start with is guaranteed to be +wrong if the curve is convex or concave + + align:start position:0% +wrong if the curve is convex or concave + + + align:start position:0% +wrong if the curve is convex or concave +can we somehow correct it so that for + + align:start position:0% +can we somehow correct it so that for + + + align:start position:0% +can we somehow correct it so that for +example instead of a immediately aiming + + align:start position:0% +example instead of a immediately aiming + + + align:start position:0% +example instead of a immediately aiming +there can't we somehow aim it so that by + + align:start position:0% +there can't we somehow aim it so that by + + + align:start position:0% +there can't we somehow aim it so that by +luck we just the next step just lands us + + align:start position:0% +luck we just the next step just lands us + + + align:start position:0% +luck we just the next step just lands us +back on the curve again in other words + + align:start position:0% +back on the curve again in other words + + + align:start position:0% +back on the curve again in other words +we're sort of looking for the short path + + align:start position:0% +we're sort of looking for the short path + + + align:start position:0% +we're sort of looking for the short path +a shortcut path which by good luck will + + align:start position:0% +a shortcut path which by good luck will + + + align:start position:0% +a shortcut path which by good luck will +end us up back on the curve again and + + align:start position:0% +end us up back on the curve again and + + + align:start position:0% +end us up back on the curve again and +all the Improv ments the simple + + align:start position:0% +all the Improv ments the simple + + + align:start position:0% +all the Improv ments the simple +improvements on Oiler method method and + + align:start position:0% +improvements on Oiler method method and + + + align:start position:0% +improvements on Oiler method method and +they are the most stable in ways to do + + align:start position:0% +they are the most stable in ways to do + + + align:start position:0% +they are the most stable in ways to do +solve differential equations numerically + + align:start position:0% +solve differential equations numerically + + + align:start position:0% +solve differential equations numerically +aim at finding a better + + align:start position:0% +aim at finding a better + + + align:start position:0% +aim at finding a better +slope so they find a better value for a + + align:start position:0% +slope so they find a better value for a + + + align:start position:0% +slope so they find a better value for a +better a better slope find a better + + align:start position:0% +better a better slope find a better + + + align:start position:0% +better a better slope find a better +value value + + align:start position:0% +value value + + + align:start position:0% +value value +for than a + + align:start position:0% +for than a + + + align:start position:0% +for than a +n try to improve that slope that you + + align:start position:0% +n try to improve that slope that you + + + align:start position:0% +n try to improve that slope that you +found now once you have the idea that + + align:start position:0% +found now once you have the idea that + + + align:start position:0% +found now once you have the idea that +you should look for a better slope uh + + align:start position:0% +you should look for a better slope uh + + + align:start position:0% +you should look for a better slope uh +it's not very difficult to see what in + + align:start position:0% +it's not very difficult to see what in + + + align:start position:0% +it's not very difficult to see what in +fact you should try again I think most + + align:start position:0% +fact you should try again I think most + + + align:start position:0% +fact you should try again I think most +of you would say uh hey I would have + + align:start position:0% +of you would say uh hey I would have + + + align:start position:0% +of you would say uh hey I would have +thought of + + align:start position:0% +thought of + + + align:start position:0% +thought of +that uh and you'd be closer in time + + align:start position:0% +that uh and you'd be closer in time + + + align:start position:0% +that uh and you'd be closer in time +since these methods were only found + + align:start position:0% +since these methods were only found + + + align:start position:0% +since these methods were only found +about uh maybe 100 around the turn of + + align:start position:0% +about uh maybe 100 around the turn of + + + align:start position:0% +about uh maybe 100 around the turn of +the last century is when I plac + + align:start position:0% +the last century is when I plac + + + align:start position:0% +the last century is when I plac +them mostly by some German + + align:start position:0% +them mostly by some German + + + align:start position:0% +them mostly by some German +mathematicians interested in solving + + align:start position:0% +mathematicians interested in solving + + + align:start position:0% +mathematicians interested in solving +equations numerically all right so what + + align:start position:0% +equations numerically all right so what + + + align:start position:0% +equations numerically all right so what +is uh the better method + + align:start position:0% +is uh the better method + + + align:start position:0% +is uh the better method +our better slope what should we look for + + align:start position:0% +our better slope what should we look for + + + align:start position:0% +our better slope what should we look for +in our better slope well the simplest + + align:start position:0% +in our better slope well the simplest + + + align:start position:0% +in our better slope well the simplest +procedure is once again we're starting + + align:start position:0% +procedure is once again we're starting + + + align:start position:0% +procedure is once again we're starting +from there and the oiler slope would be + + align:start position:0% +from there and the oiler slope would be + + + align:start position:0% +from there and the oiler slope would be +the same as the line element so it uh + + align:start position:0% +the same as the line element so it uh + + + align:start position:0% +the same as the line element so it uh +the line element looks like this and our + + align:start position:0% +the line element looks like this and our + + + align:start position:0% +the line element looks like this and our +yellow slope a an I'll still continue to + + align:start position:0% +yellow slope a an I'll still continue to + + + align:start position:0% +yellow slope a an I'll still continue to +call it a goes like that and gets to + + align:start position:0% +call it a goes like that and gets to + + + align:start position:0% +call it a goes like that and gets to +here okay now if it were convex if the + + align:start position:0% +here okay now if it were convex if the + + + align:start position:0% +here okay now if it were convex if the +curve were convex this would be too low + + align:start position:0% +curve were convex this would be too low + + + align:start position:0% +curve were convex this would be too low +and therefore the next step would + + align:start position:0% +and therefore the next step would + + + align:start position:0% +and therefore the next step would +be I'm going to draw this next step in + + align:start position:0% +be I'm going to draw this next step in + + + align:start position:0% +be I'm going to draw this next step in +pink well uh let's let's continue in uh + + align:start position:0% +pink well uh let's let's continue in uh + + + align:start position:0% +pink well uh let's let's continue in uh +here would be uh going up like that I'll + + align:start position:0% +here would be uh going up like that I'll + + + align:start position:0% +here would be uh going up like that I'll +call this BN just because it's the next + + align:start position:0% +call this BN just because it's the next + + + align:start position:0% +call this BN just because it's the next +step of Oilers method it could be called + + align:start position:0% +step of Oilers method it could be called + + + align:start position:0% +step of Oilers method it could be called +a an prime or something like that but + + align:start position:0% +a an prime or something like that but + + + align:start position:0% +a an prime or something like that but +this will do and now what you do is let + + align:start position:0% +this will do and now what you do is let + + + align:start position:0% +this will do and now what you do is let +me put an arrow on it to indicate + + align:start position:0% +me put an arrow on it to indicate + + + align:start position:0% +me put an arrow on it to indicate +parallel this go back to the beginning + + align:start position:0% +parallel this go back to the beginning + + + align:start position:0% +parallel this go back to the beginning +draw this parallel to BN so here is BN + + align:start position:0% +draw this parallel to BN so here is BN + + + align:start position:0% +draw this parallel to BN so here is BN +again just a line of slope that same + + align:start position:0% +again just a line of slope that same + + + align:start position:0% +again just a line of slope that same +slope and now what you should use as the + + align:start position:0% +slope and now what you should use as the + + + align:start position:0% +slope and now what you should use as the +simplest Improvement on Oilers method is + + align:start position:0% +simplest Improvement on Oilers method is + + + align:start position:0% +simplest Improvement on Oilers method is +take the average of these two because + + align:start position:0% +take the average of these two because + + + align:start position:0% +take the average of these two because +that's more likely to hit the curve than + + align:start position:0% +that's more likely to hit the curve than + + + align:start position:0% +that's more likely to hit the curve than +a an will which is sure to be too low if + + align:start position:0% +a an will which is sure to be too low if + + + align:start position:0% +a an will which is sure to be too low if +the curve is convex in other words use + + align:start position:0% +the curve is convex in other words use + + + align:start position:0% +the curve is convex in other words use +this instead use + + align:start position:0% +this instead use + + + align:start position:0% +this instead use +that so this is our better + + align:start position:0% + + + + align:start position:0% + +slope okay what will we call that slope + + align:start position:0% +slope okay what will we call that slope + + + align:start position:0% +slope okay what will we call that slope +we don't have to call it anything what + + align:start position:0% +we don't have to call it anything what + + + align:start position:0% +we don't have to call it anything what +would the equations for the method be + + align:start position:0% +would the equations for the method be + + + align:start position:0% +would the equations for the method be +well xn + 1 is gotten by adding the step + + align:start position:0% +well xn + 1 is gotten by adding the step + + + align:start position:0% +well xn + 1 is gotten by adding the step +size so here's my step size just as it + + align:start position:0% +size so here's my step size just as it + + + align:start position:0% +size so here's my step size just as it +was + + align:start position:0% +was + + + align:start position:0% +was +before just as it was before the new + + align:start position:0% +before just as it was before the new + + + align:start position:0% +before just as it was before the new +thing is how to get the new value of y + + align:start position:0% +thing is how to get the new value of y + + + align:start position:0% +thing is how to get the new value of y +so y n + one should be the old YN plus h + + align:start position:0% +so y n + one should be the old YN plus h + + + align:start position:0% +so y n + one should be the old YN plus h +* not this crummy slope a n but the + + align:start position:0% +* not this crummy slope a n but the + + + align:start position:0% +* not this crummy slope a n but the +better the pink slope what's the formula + + align:start position:0% +better the pink slope what's the formula + + + align:start position:0% +better the pink slope what's the formula +for the pink slope well let's do it in + + align:start position:0% +for the pink slope well let's do it in + + + align:start position:0% +for the pink slope well let's do it in +two steps it's the average of a and + + align:start position:0% + + + + align:start position:0% + +BN hey but you didn't tell me or I + + align:start position:0% +BN hey but you didn't tell me or I + + + align:start position:0% +BN hey but you didn't tell me or I +didn't tell you what BN was so you now + + align:start position:0% +didn't tell you what BN was so you now + + + align:start position:0% +didn't tell you what BN was so you now +must tell the computer oh yes by the way + + align:start position:0% +must tell the computer oh yes by the way + + + align:start position:0% +must tell the computer oh yes by the way +you remember that a an was what it + + align:start position:0% +you remember that a an was what it + + + align:start position:0% +you remember that a an was what it +always was + + align:start position:0% +always was + + + align:start position:0% +always was +the interesting thing is what is BN well + + align:start position:0% +the interesting thing is what is BN well + + + align:start position:0% +the interesting thing is what is BN well +to get BN BN is the slope of the line + + align:start position:0% +to get BN BN is the slope of the line + + + align:start position:0% +to get BN BN is the slope of the line +element at this new + + align:start position:0% +element at this new + + + align:start position:0% +element at this new +point now what am I going to call that + + align:start position:0% +point now what am I going to call that + + + align:start position:0% +point now what am I going to call that +new point I don't want to call this y + + align:start position:0% +new point I don't want to call this y + + + align:start position:0% +new point I don't want to call this y +value YN + one because that's it's this + + align:start position:0% +value YN + one because that's it's this + + + align:start position:0% +value YN + one because that's it's this +up here that's going to be the YN plus + + align:start position:0% +up here that's going to be the YN plus + + + align:start position:0% +up here that's going to be the YN plus +one all this is is a temporary value + + align:start position:0% +one all this is is a temporary value + + + align:start position:0% +one all this is is a temporary value +used to make another calculation which + + align:start position:0% +used to make another calculation which + + + align:start position:0% +used to make another calculation which +will then be combined with the previous + + align:start position:0% +will then be combined with the previous + + + align:start position:0% +will then be combined with the previous +calculations to get the right value + + align:start position:0% +calculations to get the right value + + + align:start position:0% +calculations to get the right value +therefore give it a temporary + + align:start position:0% +therefore give it a temporary + + + align:start position:0% +therefore give it a temporary +name that point we'll call it it's not + + align:start position:0% +name that point we'll call it it's not + + + align:start position:0% +name that point we'll call it it's not +going to be the final the real YN + one + + align:start position:0% +going to be the final the real YN + one + + + align:start position:0% +going to be the final the real YN + one +we'll call it yn+1 twiddles YN plus1 + + align:start position:0% +we'll call it yn+1 twiddles YN plus1 + + + align:start position:0% +we'll call it yn+1 twiddles YN plus1 +temporary uh and what's the formula for + + align:start position:0% +temporary uh and what's the formula for + + + align:start position:0% +temporary uh and what's the formula for +it well it's just going to be what the + + align:start position:0% +it well it's just going to be what the + + + align:start position:0% +it well it's just going to be what the +oiler formula original Oiler formula + + align:start position:0% +oiler formula original Oiler formula + + + align:start position:0% +oiler formula original Oiler formula +it's going to be YN plus what you would + + align:start position:0% +it's going to be YN plus what you would + + + align:start position:0% +it's going to be YN plus what you would +have gotten if you would + + align:start position:0% +have gotten if you would + + + align:start position:0% +have gotten if you would +calculated in other words it's the point + + align:start position:0% +calculated in other words it's the point + + + align:start position:0% +calculated in other words it's the point +that the oiler method produced + + align:start position:0% +that the oiler method produced + + + align:start position:0% +that the oiler method produced +uh but it's not finally the point that + + align:start position:0% +uh but it's not finally the point that + + + align:start position:0% +uh but it's not finally the point that +we + + align:start position:0% +we + + + align:start position:0% +we +want now do I have to say anything else + + align:start position:0% +want now do I have to say anything else + + + align:start position:0% +want now do I have to say anything else +uh yeah I didn't tell the computer what + + align:start position:0% +uh yeah I didn't tell the computer what + + + align:start position:0% +uh yeah I didn't tell the computer what +BN was okay BN is the + + align:start position:0% +BN was okay BN is the + + + align:start position:0% +BN was okay BN is the +slope of the direction field at the + + align:start position:0% +slope of the direction field at the + + + align:start position:0% +slope of the direction field at the +point n + one and the computer knows + + align:start position:0% +point n + one and the computer knows + + + align:start position:0% +point n + one and the computer knows +what that is and this point y n + one + + align:start position:0% +what that is and this point y n + one + + + align:start position:0% +what that is and this point y n + one +temporary + + align:start position:0% + + + + align:start position:0% + +so you make a temporary choice of this + + align:start position:0% +so you make a temporary choice of this + + + align:start position:0% +so you make a temporary choice of this +calculate that number and then go back + + align:start position:0% +calculate that number and then go back + + + align:start position:0% +calculate that number and then go back +and as it were correct that value to + + align:start position:0% +and as it were correct that value to + + + align:start position:0% +and as it were correct that value to +this value by using this better + + align:start position:0% + + + + align:start position:0% + +slope now that's all there is to the + + align:start position:0% +slope now that's all there is to the + + + align:start position:0% +slope now that's all there is to the +method except I didn't give you its name + + align:start position:0% +method except I didn't give you its name + + + align:start position:0% +method except I didn't give you its name +uh well it has three names four names in + + align:start position:0% +uh well it has three names four names in + + + align:start position:0% +uh well it has three names four names in +fact uh which one shall I give you uh I + + align:start position:0% +fact uh which one shall I give you uh I + + + align:start position:0% +fact uh which one shall I give you uh I +don't + + align:start position:0% +don't + + + align:start position:0% +don't +care okay if you the short name is hoins + + align:start position:0% +care okay if you the short name is hoins + + + align:start position:0% +care okay if you the short name is hoins +Method but nobody knows pronounces that + + align:start position:0% +Method but nobody knows pronounces that + + + align:start position:0% +Method but nobody knows pronounces that +correctly uh so that's Hy's method uh + + align:start position:0% +correctly uh so that's Hy's method uh + + + align:start position:0% +correctly uh so that's Hy's method uh +it's called also the improved Oiler + + align:start position:0% + + + + align:start position:0% + +method it's called modified + + align:start position:0% +method it's called modified + + + align:start position:0% +method it's called modified +Oiler very expressive + + align:start position:0% +Oiler very expressive + + + align:start position:0% +Oiler very expressive +word modified Oilers method and it's + + align:start position:0% +word modified Oilers method and it's + + + align:start position:0% +word modified Oilers method and it's +also called AR + + align:start position:0% +also called AR + + + align:start position:0% +also called AR +K2 I'm sure you'll like that name best + + align:start position:0% +K2 I'm sure you'll like that name best + + + align:start position:0% +K2 I'm sure you'll like that name best +it has a Star Wars sort of sound to it + + align:start position:0% +it has a Star Wars sort of sound to it + + + align:start position:0% +it has a Star Wars sort of sound to it +uh R Cas stands for runga cuta and the + + align:start position:0% +uh R Cas stands for runga cuta and the + + + align:start position:0% +uh R Cas stands for runga cuta and the +reason for the + + align:start position:0% +reason for the + + + align:start position:0% +reason for the +two is not that it uses two well it is + + align:start position:0% +two is not that it uses two well it is + + + align:start position:0% +two is not that it uses two well it is +that it uses two slopes but the real + + align:start position:0% +that it uses two slopes but the real + + + align:start position:0% +that it uses two slopes but the real +reason for the two is that it it is a + + align:start position:0% +reason for the two is that it it is a + + + align:start position:0% +reason for the two is that it it is a +second order method so let's that's the + + align:start position:0% +second order method so let's that's the + + + align:start position:0% +second order method so let's that's the +most important thing to put down about + + align:start position:0% +most important thing to put down about + + + align:start position:0% +most important thing to put down about +it it's a second order method whereas + + align:start position:0% +it it's a second order method whereas + + + align:start position:0% +it it's a second order method whereas +Oilers was only a first order method so + + align:start position:0% +Oilers was only a first order method so + + + align:start position:0% +Oilers was only a first order method so +this is a so Ho's + + align:start position:0% +this is a so Ho's + + + align:start position:0% +this is a so Ho's +method or rk2 let's write it that's the + + align:start position:0% +method or rk2 let's write it that's the + + + align:start position:0% +method or rk2 let's write it that's the +shortest thing to write is a second + + align:start position:0% +shortest thing to write is a second + + + align:start position:0% +shortest thing to write is a second +order method + + align:start position:0% +order method + + + align:start position:0% +order method +meaning that the error varies with the + + align:start position:0% +meaning that the error varies with the + + + align:start position:0% +meaning that the error varies with the +step + + align:start position:0% +step + + + align:start position:0% +step +size like some constant it won't be the + + align:start position:0% +size like some constant it won't be the + + + align:start position:0% +size like some constant it won't be the +same as the constant for Oilers method + + align:start position:0% +same as the constant for Oilers method + + + align:start position:0% +same as the constant for Oilers method +times H + + align:start position:0% +times H + + + align:start position:0% +times H +squared that's a big saving because it + + align:start position:0% +squared that's a big saving because it + + + align:start position:0% +squared that's a big saving because it +now means that if you have the step size + + align:start position:0% +now means that if you have the step size + + + align:start position:0% +now means that if you have the step size +you're going to decrease the error by a + + align:start position:0% +you're going to decrease the error by a + + + align:start position:0% +you're going to decrease the error by a +factor of one quarter you will quarter + + align:start position:0% +factor of one quarter you will quarter + + + align:start position:0% +factor of one quarter you will quarter +the + + align:start position:0% +the + + + align:start position:0% +the +error now you say hey great why should + + align:start position:0% +error now you say hey great why should + + + align:start position:0% +error now you say hey great why should +anyone use anything else well think a + + align:start position:0% +anyone use anything else well think a + + + align:start position:0% +anyone use anything else well think a +little second the real thing which + + align:start position:0% +little second the real thing which + + + align:start position:0% +little second the real thing which +determines how slowly one of these + + align:start position:0% +determines how slowly one of these + + + align:start position:0% +determines how slowly one of these +methods run is you look at the hardest + + align:start position:0% +methods run is you look at the hardest + + + align:start position:0% +methods run is you look at the hardest +step of the method and ask how long does + + align:start position:0% +step of the method and ask how long does + + + align:start position:0% +step of the method and ask how long does +the computer take how many of those + + align:start position:0% +the computer take how many of those + + + align:start position:0% +the computer take how many of those +hardest steps are there now the answer + + align:start position:0% +hardest steps are there now the answer + + + align:start position:0% +hardest steps are there now the answer +is the hardest step is always the + + align:start position:0% +is the hardest step is always the + + + align:start position:0% +is the hardest step is always the +evaluation of the slope the evaluation + + align:start position:0% +evaluation of the slope the evaluation + + + align:start position:0% +evaluation of the slope the evaluation +of the function because you know I the + + align:start position:0% +of the function because you know I the + + + align:start position:0% +of the function because you know I the +functions that are in common use are not + + align:start position:0% +functions that are in common use are not + + + align:start position:0% +functions that are in common use are not +x^2 minus y^2 they take half a page and + + align:start position:0% +x^2 minus y^2 they take half a page and + + + align:start position:0% +x^2 minus y^2 they take half a page and +have his coefficients you know 10 + + align:start position:0% +have his coefficients you know 10 + + + align:start position:0% +have his coefficients you know 10 +decimal place numbers whatever the guy + + align:start position:0% +decimal place numbers whatever the guy + + + align:start position:0% +decimal place numbers whatever the guy +the engineer is doing it you know + + align:start position:0% +the engineer is doing it you know + + + align:start position:0% +the engineer is doing it you know +whatever their accuracy + + align:start position:0% +whatever their accuracy + + + align:start position:0% +whatever their accuracy +was so the thing that controls how long + + align:start position:0% +was so the thing that controls how long + + + align:start position:0% +was so the thing that controls how long +a method runs is how many times the + + align:start position:0% +a method runs is how many times the + + + align:start position:0% +a method runs is how many times the +slope the function must be + + align:start position:0% +slope the function must be + + + align:start position:0% +slope the function must be +evaluated for Oiler I only have to + + align:start position:0% +evaluated for Oiler I only have to + + + align:start position:0% +evaluated for Oiler I only have to +evaluate it + + align:start position:0% + + + + align:start position:0% + +once here I have to evaluate it + + align:start position:0% + + + + align:start position:0% + +twice now roughly speaking the number of + + align:start position:0% +twice now roughly speaking the number of + + + align:start position:0% +twice now roughly speaking the number of +function evaluations will each will give + + align:start position:0% +function evaluations will each will give + + + align:start position:0% +function evaluations will each will give +you the exponent the method that's + + align:start position:0% +you the exponent the method that's + + + align:start position:0% +you the exponent the method that's +called rung a cut a fourth order will + + align:start position:0% +called rung a cut a fourth order will + + + align:start position:0% +called rung a cut a fourth order will +require four evaluations of slope but + + align:start position:0% +require four evaluations of slope but + + + align:start position:0% +require four evaluations of slope but +the accuracy will be like H to the + + align:start position:0% +the accuracy will be like H to the + + + align:start position:0% +the accuracy will be like H to the +4th very accurate you have the step size + + align:start position:0% +4th very accurate you have the step size + + + align:start position:0% +4th very accurate you have the step size +and it goes down by a factor of 16 great + + align:start position:0% +and it goes down by a factor of 16 great + + + align:start position:0% +and it goes down by a factor of 16 great +but you had to do it for you had to + + align:start position:0% +but you had to do it for you had to + + + align:start position:0% +but you had to do it for you had to +evaluate the slope four times suppose + + align:start position:0% +evaluate the slope four times suppose + + + align:start position:0% +evaluate the slope four times suppose +instead you + + align:start position:0% +instead you + + + align:start position:0% +instead you +had + + align:start position:0% +had + + + align:start position:0% +had +have four times this thing and what + + align:start position:0% +have four times this thing and what + + + align:start position:0% +have four times this thing and what +would you have done you would have + + align:start position:0% +would you have done you would have + + + align:start position:0% +would you have done you would have +decreased it to 116th of what it + + align:start position:0% +decreased it to 116th of what it + + + align:start position:0% +decreased it to 116th of what it +was you still you would increase the + + align:start position:0% +was you still you would increase the + + + align:start position:0% +was you still you would increase the +number of functions evaluations you + + align:start position:0% +number of functions evaluations you + + + align:start position:0% +number of functions evaluations you +needed + + align:start position:0% +needed + + + align:start position:0% +needed +to four and you would have decreased the + + align:start position:0% +to four and you would have decreased the + + + align:start position:0% +to four and you would have decreased the +error by a 16th so in some sense it + + align:start position:0% +error by a 16th so in some sense it + + + align:start position:0% +error by a 16th so in some sense it +really doesn't matter whether you use a + + align:start position:0% +really doesn't matter whether you use a + + + align:start position:0% +really doesn't matter whether you use a +very fancy method which requires more + + align:start position:0% +very fancy method which requires more + + + align:start position:0% +very fancy method which requires more +function evaluation it's true the eror + + align:start position:0% +function evaluation it's true the eror + + + align:start position:0% +function evaluation it's true the eror +goes down faster but you having to do + + align:start position:0% +goes down faster but you having to do + + + align:start position:0% +goes down faster but you having to do +more work to get it so anyway nothing's + + align:start position:0% +more work to get it so anyway nothing's + + + align:start position:0% +more work to get it so anyway nothing's +free now uh I was I there is an arcave + + align:start position:0% +free now uh I was I there is an arcave + + + align:start position:0% +free now uh I was I there is an arcave +for I think I'll skip that since I + + align:start position:0% +for I think I'll skip that since I + + + align:start position:0% +for I think I'll skip that since I +wouldn't dare to ask you any questions + + align:start position:0% +wouldn't dare to ask you any questions + + + align:start position:0% +wouldn't dare to ask you any questions +about it but uh let me I just mention it + + align:start position:0% +about it but uh let me I just mention it + + + align:start position:0% +about it but uh let me I just mention it +at least because it's the standard it + + align:start position:0% +at least because it's the standard it + + + align:start position:0% +at least because it's the standard it +uses for evaluation it's the standard + + align:start position:0% +uses for evaluation it's the standard + + + align:start position:0% +uses for evaluation it's the standard +method if uh you don't want to do + + align:start position:0% +method if uh you don't want to do + + + align:start position:0% +method if uh you don't want to do +anything fancier uh it's rather + + align:start position:0% +anything fancier uh it's rather + + + align:start position:0% +anything fancier uh it's rather +inefficient but it's very accurate + + align:start position:0% +inefficient but it's very accurate + + + align:start position:0% +inefficient but it's very accurate +standard method uh + + align:start position:0% +standard method uh + + + align:start position:0% +standard method uh +accurate and uh you'll see when you use + + align:start position:0% +accurate and uh you'll see when you use + + + align:start position:0% +accurate and uh you'll see when you use +the programs it's in fact the program + + align:start position:0% +the programs it's in fact the program + + + align:start position:0% +the programs it's in fact the program +which is drawing those curves the + + align:start position:0% +which is drawing those curves the + + + align:start position:0% +which is drawing those curves the +numerical method which draws all those + + align:start position:0% +numerical method which draws all those + + + align:start position:0% +numerical method which draws all those +curves that you believe + + align:start position:0% +curves that you believe + + + align:start position:0% +curves that you believe +in uh on the computer screen is the rk4 + + align:start position:0% +in uh on the computer screen is the rk4 + + + align:start position:0% +in uh on the computer screen is the rk4 +method the runga cut up I should give + + align:start position:0% +method the runga cut up I should give + + + align:start position:0% +method the runga cut up I should give +them the names rangaka fourth order + + align:start position:0% + + + + align:start position:0% + +method two mathemati two I believe both + + align:start position:0% +method two mathemati two I believe both + + + align:start position:0% +method two mathemati two I believe both +German mathematicians around the turn of + + align:start position:0% +German mathematicians around the turn of + + + align:start position:0% +German mathematicians around the turn of +last century rangaka fourth order + + align:start position:0% + + + + align:start position:0% + +method requires four + + align:start position:0% + + + + align:start position:0% + +slopes requires you to calculate four + + align:start position:0% +slopes requires you to calculate four + + + align:start position:0% +slopes requires you to calculate four +slopes I won't bother telling you what + + align:start position:0% +slopes I won't bother telling you what + + + align:start position:0% +slopes I won't bother telling you what +you do but it's a procedure like that + + align:start position:0% +you do but it's a procedure like that + + + align:start position:0% +you do but it's a procedure like that +it's just a little more elaborate and + + align:start position:0% +it's just a little more elaborate and + + + align:start position:0% +it's just a little more elaborate and +you take two of these you make up a + + align:start position:0% +you take two of these you make up a + + + align:start position:0% +you take two of these you make up a +weighted average for the super slope you + + align:start position:0% +weighted average for the super slope you + + + align:start position:0% +weighted average for the super slope you +use weighted average what should I + + align:start position:0% +use weighted average what should I + + + align:start position:0% +use weighted average what should I +divide that + + align:start position:0% +divide that + + + align:start position:0% +divide that +by to get the + + align:start position:0% +by to get the + + + align:start position:0% +by to get the +right + + align:start position:0% +right + + + align:start position:0% +right +six why why six well because if all + + align:start position:0% +six why why six well because if all + + + align:start position:0% +six why why six well because if all +these numbers were the same I'd want it + + align:start position:0% +these numbers were the same I'd want it + + + align:start position:0% +these numbers were the same I'd want it +to come out to be whatever that common + + align:start position:0% +to come out to be whatever that common + + + align:start position:0% +to come out to be whatever that common +value was therefore you always must + + align:start position:0% +value was therefore you always must + + + align:start position:0% +value was therefore you always must +divide by in a weighted average you must + + align:start position:0% +divide by in a weighted average you must + + + align:start position:0% +divide by in a weighted average you must +always divide by the sum of the + + align:start position:0% +always divide by the sum of the + + + align:start position:0% +always divide by the sum of the +coefficients so this is the super + + align:start position:0% + + + + align:start position:0% + +slope and if you plug that super slope + + align:start position:0% +slope and if you plug that super slope + + + align:start position:0% +slope and if you plug that super slope +in uh to here you will be using the + + align:start position:0% +in uh to here you will be using the + + + align:start position:0% +in uh to here you will be using the +wrong a cutter method and get the best + + align:start position:0% +wrong a cutter method and get the best + + + align:start position:0% +wrong a cutter method and get the best +possible results now I wanted to spend + + align:start position:0% +possible results now I wanted to spend + + + align:start position:0% +possible results now I wanted to spend +the last three minutes uh talking about + + align:start position:0% +the last three minutes uh talking about + + + align:start position:0% +the last three minutes uh talking about +pitfalls of numerical computation in + + align:start position:0% +pitfalls of numerical computation in + + + align:start position:0% +pitfalls of numerical computation in +general uh one Pitfall I'm leaving you + + align:start position:0% +general uh one Pitfall I'm leaving you + + + align:start position:0% +general uh one Pitfall I'm leaving you +on the homework to discover for + + align:start position:0% + + + + align:start position:0% + +yourself don't worry it won't cause you + + align:start position:0% +yourself don't worry it won't cause you + + + align:start position:0% +yourself don't worry it won't cause you +any grief + + align:start position:0% +any grief + + + align:start position:0% +any grief +just it'll just destroy your faith in + + align:start position:0% +just it'll just destroy your faith in + + + align:start position:0% +just it'll just destroy your faith in +these things for the rest of your life + + align:start position:0% +these things for the rest of your life + + + align:start position:0% +these things for the rest of your life +which is probably a good thing so + + align:start position:0% + + + + align:start position:0% + +pitfalls number one you find you'll + + align:start position:0% +pitfalls number one you find you'll + + + align:start position:0% +pitfalls number one you find you'll +find let me talk instead briefly about + + align:start position:0% +find let me talk instead briefly about + + + align:start position:0% +find let me talk instead briefly about +number two which I'm not giving you an + + align:start position:0% +number two which I'm not giving you an + + + align:start position:0% +number two which I'm not giving you an +exercise in number two is illustrated by + + align:start position:0% +exercise in number two is illustrated by + + + align:start position:0% +exercise in number two is illustrated by +the following + + align:start position:0% +the following + + + align:start position:0% +the following +equation what could be + + align:start position:0% +equation what could be + + + align:start position:0% +equation what could be +simpler this is a very bad equation to + + align:start position:0% +simpler this is a very bad equation to + + + align:start position:0% +simpler this is a very bad equation to +try to solve numerically now why well + + align:start position:0% +try to solve numerically now why well + + + align:start position:0% +try to solve numerically now why well +because if I separate + + align:start position:0% +because if I separate + + + align:start position:0% +because if I separate +variables uh why don't I save a little + + align:start position:0% +variables uh why don't I save a little + + + align:start position:0% +variables uh why don't I save a little +time I'll just tell you what the + + align:start position:0% +time I'll just tell you what the + + + align:start position:0% +time I'll just tell you what the +solution is okay okay you obviously you + + align:start position:0% +solution is okay okay you obviously you + + + align:start position:0% +solution is okay okay you obviously you +separate variables maybe you can do it + + align:start position:0% +separate variables maybe you can do it + + + align:start position:0% +separate variables maybe you can do it +in your head the solution will be the + + align:start position:0% +in your head the solution will be the + + + align:start position:0% +in your head the solution will be the +solutions will have an arbitrary + + align:start position:0% +solutions will have an arbitrary + + + align:start position:0% +solutions will have an arbitrary +constant in them and they won't be very + + align:start position:0% +constant in them and they won't be very + + + align:start position:0% +constant in them and they won't be very +complicated they will be one over C + + align:start position:0% +complicated they will be one over C + + + align:start position:0% +complicated they will be one over C +minus + + align:start position:0% +minus + + + align:start position:0% +minus +x c is an arbitrary constant and as you + + align:start position:0% +x c is an arbitrary constant and as you + + + align:start position:0% +x c is an arbitrary constant and as you +give different values you get now what + + align:start position:0% +give different values you get now what + + + align:start position:0% +give different values you get now what +do those guys look like okay so here I + + align:start position:0% +do those guys look like okay so here I + + + align:start position:0% +do those guys look like okay so here I +am I I'm start out at The Point one and + + align:start position:0% +am I I'm start out at The Point one and + + + align:start position:0% +am I I'm start out at The Point one and +I start out I tell the computer compute + + align:start position:0% +I start out I tell the computer compute + + + align:start position:0% +I start out I tell the computer compute +for me the value of the solution at one + + align:start position:0% +for me the value of the solution at one + + + align:start position:0% +for me the value of the solution at one +starting out at one and it computes and + + align:start position:0% +starting out at one and it computes and + + + align:start position:0% +starting out at one and it computes and +computes a little while but the solution + + align:start position:0% +computes a little while but the solution + + + align:start position:0% +computes a little while but the solution +how does this curve actually look so in + + align:start position:0% +how does this curve actually look so in + + + align:start position:0% +how does this curve actually look so in +other words suppose I say that y of 0 + + align:start position:0% +other words suppose I say that y of 0 + + + align:start position:0% +other words suppose I say that y of 0 +equals 1 find me y of two in other words + + align:start position:0% +equals 1 find me y of two in other words + + + align:start position:0% +equals 1 find me y of two in other words +take a a nice small step size use the + + align:start position:0% +take a a nice small step size use the + + + align:start position:0% +take a a nice small step size use the +rung of cut of fourth order method + + align:start position:0% +rung of cut of fourth order method + + + align:start position:0% +rung of cut of fourth order method +calculate a little bit and tell me I + + align:start position:0% +calculate a little bit and tell me I + + + align:start position:0% +calculate a little bit and tell me I +just want to know what y of two + + align:start position:0% +just want to know what y of two + + + align:start position:0% +just want to know what y of two +is well what is y of2 oh well + + align:start position:0% +is well what is y of2 oh well + + + align:start position:0% +is well what is y of2 oh well +unfortunately how does that curve look + + align:start position:0% +unfortunately how does that curve look + + + align:start position:0% +unfortunately how does that curve look +the curve looks like this + + align:start position:0% + + + + align:start position:0% + +at that point it drops to + + align:start position:0% +at that point it drops to + + + align:start position:0% +at that point it drops to +Infinity in a manner of speaking and + + align:start position:0% +Infinity in a manner of speaking and + + + align:start position:0% +Infinity in a manner of speaking and +then sort of comes back up again like + + align:start position:0% +then sort of comes back up again like + + + align:start position:0% +then sort of comes back up again like +that what is the value of y this is the + + align:start position:0% +that what is the value of y this is the + + + align:start position:0% +that what is the value of y this is the +point + + align:start position:0% +point + + + align:start position:0% +point +one what is the value of y of two is it + + align:start position:0% +one what is the value of y of two is it + + + align:start position:0% +one what is the value of y of two is it +here is it this well I don't know but I + + align:start position:0% +here is it this well I don't know but I + + + align:start position:0% +here is it this well I don't know but I +do know that the computer will not find + + align:start position:0% +do know that the computer will not find + + + align:start position:0% +do know that the computer will not find +it the computer will follow this along + + align:start position:0% +it the computer will follow this along + + + align:start position:0% +it the computer will follow this along +and get lost in eternity in infinity and + + align:start position:0% +and get lost in eternity in infinity and + + + align:start position:0% +and get lost in eternity in infinity and +see no reason whatever just why it + + align:start position:0% +see no reason whatever just why it + + + align:start position:0% +see no reason whatever just why it +should start again on this branch of the + + align:start position:0% +should start again on this branch of the + + + align:start position:0% +should start again on this branch of the +curve okay well we should can't we + + align:start position:0% +curve okay well we should can't we + + + align:start position:0% +curve okay well we should can't we +predict that that's going to happen + + align:start position:0% +predict that that's going to happen + + + align:start position:0% +predict that that's going to happen +somehow and you know avoided what I + + align:start position:0% +somehow and you know avoided what I + + + align:start position:0% +somehow and you know avoided what I +should have you know the whole + + align:start position:0% +should have you know the whole + + + align:start position:0% +should have you know the whole +difficulty is this is called a singular + + align:start position:0% +difficulty is this is called a singular + + + align:start position:0% +difficulty is this is called a singular +point this this solution has a + + align:start position:0% +point this this solution has a + + + align:start position:0% +point this this solution has a +singularity in other words a place where + + align:start position:0% +singularity in other words a place where + + + align:start position:0% +singularity in other words a place where +it goes to infinity or becomes + + align:start position:0% +it goes to infinity or becomes + + + align:start position:0% +it goes to infinity or becomes +discontinuous maybe has a jump + + align:start position:0% +discontinuous maybe has a jump + + + align:start position:0% +discontinuous maybe has a jump +discontinu + + align:start position:0% +discontinu + + + align:start position:0% +discontinu +it has a singularity at xal + + align:start position:0% +it has a singularity at xal + + + align:start position:0% +it has a singularity at xal +C this in particular at x equal 1 here + + align:start position:0% +C this in particular at x equal 1 here + + + align:start position:0% +C this in particular at x equal 1 here +but from the differential equation there + + align:start position:0% +but from the differential equation there + + + align:start position:0% +but from the differential equation there +is where is that c there is no way of + + align:start position:0% +is where is that c there is no way of + + + align:start position:0% +is where is that c there is no way of +predicting it each solution in other + + align:start position:0% +predicting it each solution in other + + + align:start position:0% +predicting it each solution in other +words to this differential equation has + + align:start position:0% +words to this differential equation has + + + align:start position:0% +words to this differential equation has +its own private Singularity which only + + align:start position:0% +its own private Singularity which only + + + align:start position:0% +its own private Singularity which only +it knows about and where it's going to + + align:start position:0% +it knows about and where it's going to + + + align:start position:0% +it knows about and where it's going to +blow up and there's no way of telling + + align:start position:0% +blow up and there's no way of telling + + + align:start position:0% +blow up and there's no way of telling +from the differential equation where + + align:start position:0% +from the differential equation where + + + align:start position:0% +from the differential equation where +that's going to be that's what makes + + align:start position:0% +that's going to be that's what makes + + + align:start position:0% +that's going to be that's what makes +numerical c one of the things that makes + + align:start position:0% +numerical c one of the things that makes + + + align:start position:0% +numerical c one of the things that makes +numerical calculation difficult when you + + align:start position:0% +numerical calculation difficult when you + + + align:start position:0% +numerical calculation difficult when you +cannot predict where things are going to + + align:start position:0% +cannot predict where things are going to + + + align:start position:0% +cannot predict where things are going to +go bad in advance \ No newline at end of file diff --git a/LgWFurXHX8U.txt b/LgWFurXHX8U.txt new file mode 100644 index 0000000000000000000000000000000000000000..3ef420ee3091d9926a718c6c0479a7f97f1f4266 --- /dev/null +++ b/LgWFurXHX8U.txt @@ -0,0 +1,1573 @@ +PROFESSOR: Hi. + +Well, this is sort of a summary +lecture for the big + +group about differential +calculus. + +And it's got a fancy title, Six +Functions, that we know. + +Well, five of them +that we know. + +And a new one-- of course, +there has to + +be something new-- + +Six Rules, and Six Theorems. +So I haven't emphasized + +theorems, but it seemed like +this was an occasion where we + +could see the main points of the +math behind the functions + +and the rules. + +OK. + +So, here are my first five +functions, all familiar. + +And, what I'm happy about is +that, if we understand those + +five and the rules to create +more out of them, we get + +practically everything, +everything we frequently use. + +OK. + +So, I wrote down function +one, power of x, and its + +derivative, function +two and its + +derivative, function three. + +Function four has, +a little bit, + +something that is important. + +If it's e to the x, +then we know the + +derivative is e to the x. + +But, if it's e to the c, x +of factor c, comes down. + +Important case, you could +say the chain rule. + +The derivative is that times +the derivative of what's + +inside, which is the c. + +And, finally, the natural +logarithm with the great + +derivative of 1/x. + +And now, oh, I left space +to go from function one + +backwards, to remember the +function that came before it. + +So, what function has +this derivative? + +I'm looking here at the other +generation, the older + +generation. + +Well, the function with that +derivative is we need the + +power to be one higher, right? + +And then, the derivative of +that, we need to divide by n + +plus 1 so that, when we take the +derivative, the n plus 1 + +comes down, cancels this, and +gives us x to the n-th. + +The function that comes before +sine x will be-- + +oh, there was cos x +in that direction. + +In this direction, we need +minus cos x because the + +derivative of minus cos +x is plus sine x. + +But, for this guy, cosine x, +that came from sine x. + +And, what about this one? + +What function has +this derivative? + +Well, with exponentials, we +expect to see that exponential + +always, e to the c, x again, +but, since this would bring + +down a c and here we don't +want it, we'd better + +divide by that c. + +So then, if I take that, that's +e to the c, x divided + +by c, so the c will come +down, cancel the c, + +just the way here. + +And, oh, we've never +figured out log x. + +That'll be something novel to +do for integral calculus. + +But, I think, if I write down +the answer, I think it's x + +times log x minus x. + +I believe that works. + +I would use the product +rule on that. + +x times the derivative of that +would be a 1 minus that. + +And the derivative of that +would be a 1, so two ones + +would cancel, and the product +rule would leave me with log x + +times the derivative of that. + +It works. + +It works. + +And notice the one beautiful +thing in this list, that the + +case here is great unless +I'm dividing by 0. + +If n is minus 1, +I'm in trouble. + +If n is minus 1, I don't have +here something whose-- + +if n is minus 1, I can't +divide by 0. + +I don't get x to the minus +1 out of x to the 0. + +That rule fails at +n equal minus 1. + +But look, here, is exactly +fills in that whole. + +Wonderful. + +Here is the minus 1 power, and +here is where it comes from. + +So that log just filled in the +one hole that was left there. + +OK. + +Otherwise, you know +these guys. + +But here's a new one: +a step function. + +A step function, it's 0 and it +jumps up to 1 at x equals 0. + +So, here's x. + +The function is 0 until +it gets to that point. + +So it's level, then it takes +a step up, a jump up, to 1. + +And let's say it's 1 at that +point, so it takes that jump. + +All right. + +OK. + +That's a function that's +actually quite important. + +And it's sort of like a two-part +function, it's got a + +part to the left and a +part to the right. + +And they don't meet, it's a +non-continuous function. + +Can I figure out what is it +that-- so here will be the old + +generation, what graph do +I put there so that the + +derivative is 0 and then 1? + +Well, that's not too hard. + +If I put 0's here, the +derivative will be 0. + +And now, over here, I want the +derivative to be a constant 1. + +And we know that the derivative +of x is what I + +need, so this is 0 and then +x, two parts again. + +And the derivatives of those +parts are 0 and then 1. + +And I often call that a ramp +function because it looks a + +little like a ramp. + +OK. + +What about going this way? + +Ah, that's a little more +interesting because what's the + +derivative of a step function? + +What's the slope of +a step function? + +Well, the slope here is +certainly 0, and the slope + +along here is certainly 0, +so, is the answer 0? + +Well, of course not. + +All the action is +at this jump. + +And what's the derivative +there? + +Now, a careful person +would say there is + +no derivative there. + +The limit of delta f/delta x, +you don't get a correct answer + +there because delta f jumps +by one, and delta x + +could be very small. + +And, as delta x goes to 0, we +have 1/0, we have infinite. + +Well, I say, what? + +Let's go for infinite. + +So my derivative is +0 and 0, and, at + +this point, it's infinite. + +It's a spike, or sometimes +called a delta function. + +It's 0, and then infinite at +one point, and then 0. + +And the oddball thing is that +the area under that one-point + +tower, spike, is supposed +to be 1. + +Because, do you remember-- + +and we'll do more areas if we +get to integral calculus-- + +but, the area under +this function is + +supposed to be this one. + +The area under the cosine +function is sine x. + +The area under this function +should be this one, so the + +area is 0 here. + +Run along here. + +No area under it. + +Then, I have a one-point +spike, and the area is + +supposed to jump to 1 +under that spike, + +at that single point. + +That spike is infinitely tall, +and it actually has a little + +area under it. + +Ah, well, your teacher may say +get that function out of here. + +That's not a function. + +And I'm afraid that's +a true fact that + +it's not a real function. + +So you could say I don't +want to see this + +thing, clear it out. + +But, actually, that's +very useful. + +It's a model for something that +happens very quickly: an + +instant, an impulse, so +I'll leave it there. + +I'll leave it there, +but I'll go on. + +So, if you don't like it, you +don't have to look at it. + +OK. + +So those were the +six functions, + +now for the six rules. + +Nothing too fancy here. + +I don't think I really +emphasized the most important + +and simplest rule that, if you +have as a combination, like + +you add two functions, then +the derivatives add. + +Or, if you multiply that +function by 2 and that + +function by 3 before you add, +then you multiply the + +derivatives by 2 and +3 before you add. + +It's that fact that +allowed us-- + +I mean, you've used +it all the time. + +If you integrated x plus x +squared, you used the sum rule + +to integrate-- + +ah, sorry-- + +took the derivative. + +If you want the slope of x plus +x squared, you would say + +oh, no problem: 1 plus 2x. + +1 coming from the first +function, 2x from the x + +squared function. + +So the slope of a sum is just +the sum of the slopes. + +You constantly use that to build +many more functions out + +of the simple, anything, x +squared plus x cubed plus x 4, + +if you know its derivative and +you're using this rule. + +Now, the product rule, +we worked through. + +You've practiced that. + +The quotient rule is a little +messier with this minus sign + +and the division by g squared. + +It's a fraction. + +And then, a little more +complicated, was + +this inverse function. + +Do you remember that if you +start from y equals f of x-- + +which is what we always +have been doing-- + +and then you say all right, +switch it so that x isn't the + +input anymore, it's now +the output, and the + +input is the y. + +So you're reversing +the function. + +You're flipping the graph. + +We did this to get between +e to the x and log x. + +That was the most important +case of doing this flip + +between y equals e to the +x and x equals log of y. + +And the chain rule tells us that +the derivative of this + +inverse function is 1 over the +derivative of the original. + +Nice rule. + +And here's the full-scale +chain rule. + +Oh, that deserves to be put +inside a box or something + +because this is a really +great way to create new + +functions as a chain. + +You start with x. + +You do g of x, and then +that's the input to f. + +You will know that chain rule. + +And you remember that that +produces a product, the + +derivative of f times the +derivative of g, but there was + +this little trick, right? + +This g of x was the y. + +I'll just remind you that this +g of x is the y, and you have + +to get y out of the answer. + +Use this to get an answer +in terms of x. + +Wherever you see y, you +have to put in g of x. + +So, that's the chain rule. + +And then the final rule that +I want to mention is this + +L'hopital rule about-- + +well, a lot of calculus is about +a ratio of f of x to g + +of x when it's going to 0/0. + +What do you do about 0/0? + +Well, as we're going to some +point, like x equals a, if + +this is going to 0/0, then +you're allowed to look. + +The slopes will tell you how +quickly each one is going to + +0, and the ratio becomes a +ratio of the two slopes. + +So, normally then, this answer +would be the derivative at a + +divided by the derivative +at a. + +If we're lucky, this 0/0 thing, +when we look at the + +slopes, isn't 0/0 any more. + +It's good numbers, +and L'hopital + +gets the answer right. + +OK. + +That's a review of L'hopital's +rule, just really remembering + +that that's an important rule +that came directly from the + +idea of the derivative. + +We're using the important part +of the function because the + +constant term in that +function is 0. + +Good. + +OK, are you ready for +six theorems? + +That is a handful, but +let's just tackle it. + +Why not? + +Why not? + +OK. + +So, six functions were easy. + +Well, we start with the big +theorem, the big theorem, the + +fundamental theorem +of calculus. + +The fundamental theorem +of calculus, OK, + +that ought to be important. + +And what does it say? + +It says that the two operations +of going from + +function one to two by taking +the derivative, the slope, the + +speed, is the reverse of +going the other way, + +from two back to one. + +It's really saying that, if +I start with a function-- + +Here, this would be one way. + +If I start with a function, f, +I take the derivative to get + +function two, the speed, +the slope. + +Then, if I go backwards-- + +which is this integrating that +integration symbol that's the + +core in integral calculus-- + +if I take the derivative +and then take the + +integral, I'm back to f. + +And what you actually get +in this number is f at-- + +it depends. + +It's like a delta f, really. + +It's the f at the end minus +the f at the start. + +Maybe you'll remember that. + +When we talked about it, there +was one lecture on big picture + +of the integral, and there may +be more coming, but that was + +the one where we had +this kind of thing. + +And, in the other direction, if +I start with function two, + +do its integral to get function +one, take the + +derivative of that, then I'm +back to function two. + +Actually, you're going to say +I knew that: function one to + +two, back to one. + +Or start with two, go to one, +then back to two, that's the + +fundamental theorem. + +That those two operations, +of taking the + +derivative, that limit-- + +You remember what's tricky about +all that is that this + +d,f, d,x, involves a limit +as delta x goes to 0. + +And this integral will also +involve a limit as + +delta x goes to 0. + +So that's the point at which it +became calculus instead of + +just algebra. + +Well, important. + +I should say, let's assume here, +that these functions are + +all continuous functions. + +And I'm going to assume that +these theorems will apply to + +continuous functions. + +And do you remember +what that meant? + +Basically, it meant that that +jump function is not + +continuous. + +And that delta function is-- + +well, that's not even +a function. + +The ramp function is continuous +but, of course, the + +derivative isn't. + +OK. + +All right. + +So, we've got functions that +we can draw without raising + +our pen, without lifting +the chalk. + +And here's the fact about +them, that if I have a + +continuous function on an +interval-- so, here is some + +point, a, and here is some +point, b, and my + +function goes like that. + +Oh, it doesn't do that. + +It goes like that. + +Then this thing says that this +maximum is actually reached, + +and this minimum is +actually reached. + +And any value in-between, +anywhere between this height + +and this height, there are +points where the function + +equals that. + +The continuous function hits its +maximum, hits its minimum, + +hits every point in-between. + +Where, if it wasn't continuous, +you see it could + +go up, and then, suddenly, +never reach that point, + +suddenly drop to there. + +There's a function not +continuous, of course, because + +it fell down there. + +And it never reached m because +it was this close, as close as + +it could be. + +But it never got there because, +at the last minute, + +it jumped down. + +OK. + +So, that's sort of a good +theoretical bit about + +continuous functions. + +OK. + +So, that's new. + +That was not mentioned before. + +But you can see it by just +drawing a picture where it + +hits the max, hits the min, hits +all values in-between. + +And then, you see the point, +y, continuous was needed + +because, if you let it jump, +the result doesn't work. + +OK. + +Here's another thing. + +This is now called the +mean value theorem. + +That's a neat theorem. + +OK. + +Oh. + +Now, here, our function is going +to have a derivative + +over some region. + +That function probably +had a derivative. + +OK. + +OK. + +So, that function, or this +function, f of x, here's the + +idea of the mean +value theorem. + +This is like delta f/delta +x for the whole + +interval from a to b. + +Delta x is b minus a, +the whole jump. + +Delta f is f at the end +minus f at this end. + +So that delta f/delta x is like +your average speed over + +the whole trip. + +Like you went on the +MassPike, right? + +And you entered at 1:00 o'clock +and came out at 4:00 + +o'clock, so you were on the +pike for three hours. + +And your trip meter +shows 200 miles. + +So your average speed, average +speed, was 200 divided by 3, + +that number of miles per hour. + +Yeah, about 66 miles-- well, +probably illegal. + +OK. + +A little over 66 miles an +hour: 200/3, so you're + +slightly over the speed limit. + +Well, the mean value theorem +catches you because you could + +say well, but when did +I pass the limit? + +When was I going more than 65? + +And the mean value theorem says +there was a time, there + +was a moment when your speed, +when the speedometer, itself, + +was exactly. + +This instant speed equaled +the average speed. + +Shall I say that again? + +If you travel with a smooth +changes of speed, no jumps in + +speed, then, if I look at the +average speed over a delta t, + +there is some point inside that +one where the average + +speed agrees with the +instant speed. + +Or you could say, if +you prefer slope-- + +Suppose the average slope, the +up over a cross, is 10, So in + +the time at cross, you +eventually got up 10. + +Then there will be some +point when your + +climbing rate was 10. + +There'd be some point when that +instant slope is also 10. + +OK. + +That's the mean value theorem. + +This is called the mean value. + +Mean value is another +word for average. + +So the mean value equals the +instant value at some point. + +But we don't know, that point +could be anywhere. + +OK. + +Now, I'm ready for the last two +theorems. And the first + +one is called Taylor Series, +the Taylor's theorem. + +And we have touched on that. + +And what is Taylor +Series about? + +Taylor Series is when you know +what's going on at some point + +x equal a, and you want to know +what the function is at + +some point x near a. + +So x is near a. + +And, to a very low +approximation, f of x is + +pretty close to f of a. + +This is the constant term. + +That's where the trip started. + +So this is like a trip meter +for a very short trip. + +The first thing would be to know +what was the trip meter + +reading at the start. + +But then the correction term, so +this is the calculus term, + +it's the speed at the start +times the time of the trip. + +If you only keep this, the +trip meter isn't moving. + +When you add on this, you're +like following a tangent line. + +If I try to describe it, you're +pretending the speed + +didn't change. + +Here, you're pretending the +trip meter didn't change. + +Nothing happened. + +Here is the next term. + +But now, of course, this speed +normally changes too. + +So calculus says there is +a term from the second + +derivative, there's +a bending term. + +This, we would be correct to +stop right there on a straight + +line: constant speed. + +But now, if the speed is +increasing, your trip meter + +graph is bending upwards, you'd +better have a correction + +from the second derivative. + +That's the slope of the slope, +the rate of change + +of the rate of change. + +It's the acceleration. + +So, if I had constant +acceleration, like I drop this + +chalk, it accelerates. + +So, from where I drop it, that +gives me its original height. + +Its original speed might be +0, if I hold onto it. + +But then, this term would +account for the second + +derivative, the acceleration. + +And that would give me the right +answer, the right answer + +to the next term, but now I've +drawn the famous three dots. + +So three dots is the way to +say there are more terms + +because the acceleration +might not be constant. + +What's the next term? + +If you know the next +term, then you + +and Taylor are square. + +The next term will be +1/3 factorial, 1/6. + +It'll be a third derivative of +f at the known point times + +this x minus a cubed. + +You see that these terms +are getting, + +typically, for a nice function-- + +and we saw this for +e to the x. + +We saw the Taylor Series +for e to the x. + +Can I remind you of the Taylor +Series for e to the x around + +the point 0 because e to the x +is the greatest function I've + +spoken about, at all? + +So, if this was e to the x, it +would start out at e to the 0, + +which is 1. + +Its slope is 1, so this +is 1 times x. + +Its second derivative +is, again, 1. + +And a is 0 here, so +this would be 1/2, + +1/2 factorial x squared. + +And then that next three-dot +term would be + +1/3 factorial x cube. + +And you remember what +it looks like. + +So the Taylor Series just +looks messy because I'm + +writing any old f. + +I'm allowing it to be the start +point, to be a, and not + +necessarily 0. + +But, typically, it's 0. + +And the e to the x series +is the best example. + +But I want to show you +one more example. + +That'll be my last theorem. + +I just mention it here because +it's just like + +the mean value theorem. + +If I do stop, suppose I stop +here and I don't include the x + +cube term, the third derivative +term, then I've + +made an error. + +And, of course, that error +depends on what the third + +derivative is, the one I +skipped, the x minus a cube, + +the thing I skipped, and +the 1/3 factorial. + +And this third derivative +is, at some point, + +between a and x. + +That's a lot to put in, but the +mean value theorem said + +you could take the derivative at +some point in-between, some + +point along the MassPike. + +And this is just the same thing, +but I'm keeping more + +terms. I'm quitting at any +point, and then I would take + +the next derivative at somewhere +along the MassPike. + +What should you learn +out of that? + +I think the idea is +Taylor Series. + +And, of course, we have +two possibilities. + +Either we cut the series off and +we make some error, but we + +get a pretty good answer, or we +let the series go forever. + +And then comes the question. + +Then we have an infinite number +of terms, and then the + +question is does that series add +up to a finite thing like + +e to the x? + +Or does it add up to a delta +function or something + +impossible? + +So that leads to the question +of learning + +about infinite series. + +In calculus, Taylor +Series is where + +infinite series come from. + +And, if we want to go all the +way with them, then we have to + +begin to think about what does +it mean for that infinite + +series to add up to a +number, or maybe it + +just goes off to infinity. + +Does it converge, or +does it diverge? + +Ah, that would be another +lecture or two. + +Let me complete today with one +more theorem, a famous one, + +the binomial theorem. + +So, what's the binomial +theorem about? + +The binomial theorem is about +powers of 1 plus x. + +1 plus x is a typical binomial: +two things, 1 and x. + +And we have various powers. + +Well, if the powers are the +first power, the second power, + +the third power, we can write +out, we can square 1 plus x, + +and we can get 1 plus x cubed. + +And, out of it, we get this. + +And there would be 1 plus +x to the 0-th power. + +And do you see that there's a +whole lot of ones in the neat + +pattern there? + +And then there's a +2, and a 3, 3. + +And if you'd like to know this +one, it would be 1, 4, 6, 4, 1 + +would be the next +row of Pascal. + +Pascal really had a sense of +beauty or art in this triangle + +of numbers. + +And that's the triangle you +get, Pascal's triangle, if + +you're taking-- + +A whole number, a power is 1 +plus x to the third power, + +fourth power, fifth power, +sixth power, but what if + +you're taking to some other +power, any power, p? + +So now I'm interested in this +guy to a power of p that, + +maybe, is not two, three, +four, five. + +It could be 1/2, 1 plus x square +root to the 1/2 power, + +or 1 plus x to the +minus 1 power. + +All other powers are possible +and, for those, + +the Taylor's theorem. + +And here's my function. + +And I could apply Taylor's +theorem to find the-- + +and I'll do it at x equals 0, +that's the place Taylor liked + +the best. So the +constant term-- + +think of this Taylor expansion +that we just did-- + +at x equals 0, this +thing is 1. + +So, the big theory starts +out with a 1 for + +the constant term. + +Then what I do for the next +term of the Taylor Series? + +I take the derivative and +I put x equals 0. + +And what do I get then? + +I get p times x. + +So this is the constant +term: f of 0. + +This is the derivative: +times x minus a + +divided by 1 factorial. + +Well, you didn't see all those +things because one factorial I + +didn't write. + +And then the next term would be +the next derivative, of p + +minus 1 will come down, so +you'll have p, p minus 1. + +You're supposed to divide +by 2 factorial. + +That multiplies x squared. + +Well, my point is just that +this binomial formula is + +Taylor's formula. + +The binomial theorem, with +these, this is called a + +binomial coefficient. + +Gamblers know all about +that, you know? + +If you've got p things and you +want to take two, how many + +ways to do it? + +You know, how many ways to get +two aces out of a deck, all + +these things are hidden in those +numbers, which gamblers + +learn or lose. + +OK. + +So, I'll make one last point +about the binomial theorem. + +Those were Taylor Series. + +This is a Taylor series. + +What's the difference? + +The difference is these +series stop. + +This is a series: 1 +plus x squared. + +That's the Taylor Series, +but the third + +derivative is 0, right? + +The third derivative of that +function, because that + +function's only going up to x +squared, the third derivative + +is 0, so the rest of Taylor +Series has died. + +It's not there. + +So that's all there is. + +The derivative of any of those +powers, one, two, three, four, + +five powers, after I take enough +derivatives, gone. + +But, if I take a power like +minus 1, or 1/2, or pi, or + +anything, then I can take +derivatives forever + +without hitting 0. + +In other words, this series +goes on, and on, and on. + +Those three dots-- + +let me move that eraser so you +see those three dots-- + +that signals an infinite series +and the question of + +does it add up to a finite +number, what's going on with + +infinite series? + +But, for the moment, my point +is just this is what + +calculus can do. + +If you not only take that slope, +but the slope of the + +slope, and the third derivative, +and all higher + +derivatives, that's what Taylor +Series tells you. + +OK. + +So that's the, in some way, high +point of the highlights + +of calculus, and I sure hope +they're helpful to you. + +Thank you. + +FEMALE VOICE: This has been +a production of MIT + +OpenCourseWare and +Gilbert Strang. + +Funding for this video was +provided by the Lord + +Foundation. + +To help OCW continue to provide +free and open access + +to MIT courses, please +make a donation at + +ocw.mit.edu/donate. \ No newline at end of file diff --git a/Lm4p4YPC_q0.txt b/Lm4p4YPC_q0.txt new file mode 100644 index 0000000000000000000000000000000000000000..d1ba1fa510a287c18fdb36da0c9483de6f2704c2 --- /dev/null +++ b/Lm4p4YPC_q0.txt @@ -0,0 +1,5051 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer high quality educational + + align:start position:0% +to offer high quality educational + + + align:start position:0% +to offer high quality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu uh we're the bds2 team + + align:start position:0% +ocw.mit.edu uh we're the bds2 team + + + align:start position:0% +ocw.mit.edu uh we're the bds2 team +design team to and we designed or post + + align:start position:0% +design team to and we designed or post + + + align:start position:0% +design team to and we designed or post +design the electric home owner my name + + align:start position:0% +design the electric home owner my name + + + align:start position:0% +design the electric home owner my name +is Harvey tank my colleagues are M and + + align:start position:0% +is Harvey tank my colleagues are M and + + + align:start position:0% +is Harvey tank my colleagues are M and +Eric + + align:start position:0% + + + + align:start position:0% + +Conor our main motivation for Designing + + align:start position:0% +Conor our main motivation for Designing + + + align:start position:0% +Conor our main motivation for Designing +this motor uh was that the original + + align:start position:0% +this motor uh was that the original + + + align:start position:0% +this motor uh was that the original +a assisted human power vehicle uh the + + align:start position:0% +a assisted human power vehicle uh the + + + align:start position:0% +a assisted human power vehicle uh the +motor was prohibitively expensive they + + align:start position:0% +motor was prohibitively expensive they + + + align:start position:0% +motor was prohibitively expensive they +use a new generation motor vehicle a + + align:start position:0% +use a new generation motor vehicle a + + + align:start position:0% +use a new generation motor vehicle a +motor and it cost $8,000 it's pictured + + align:start position:0% +motor and it cost $8,000 it's pictured + + + align:start position:0% +motor and it cost $8,000 it's pictured +right here our main goal was to create a + + align:start position:0% +right here our main goal was to create a + + + align:start position:0% +right here our main goal was to create a +motor that would fit in the same area + + align:start position:0% +motor that would fit in the same area + + + align:start position:0% +motor that would fit in the same area +and also as a stepping stone to move on + + align:start position:0% +and also as a stepping stone to move on + + + align:start position:0% +and also as a stepping stone to move on +to the bds2 the new + + align:start position:0% +to the bds2 the new + + + align:start position:0% +to the bds2 the new +design and these requirements were + + align:start position:0% +design and these requirements were + + + align:start position:0% +design and these requirements were +handed down to us by VDS we wanted 10 KW + + align:start position:0% +handed down to us by VDS we wanted 10 KW + + + align:start position:0% +handed down to us by VDS we wanted 10 KW +continuous power uh the original motor + + align:start position:0% +continuous power uh the original motor + + + align:start position:0% +continuous power uh the original motor +that was pictured before had + + align:start position:0% +that was pictured before had + + + align:start position:0% +that was pictured before had +3.4 uh we want 90% or above efficiently + + align:start position:0% +3.4 uh we want 90% or above efficiently + + + align:start position:0% +3.4 uh we want 90% or above efficiently +optimally at 45 mph which we considered + + align:start position:0% +optimally at 45 mph which we considered + + + align:start position:0% +optimally at 45 mph which we considered +you know reasonable speed the old motor + + align:start position:0% +you know reasonable speed the old motor + + + align:start position:0% +you know reasonable speed the old motor +had about 94% efficiency and Medi + + align:start position:0% +had about 94% efficiency and Medi + + + align:start position:0% +had about 94% efficiency and Medi +decided that it was acceptable to lose a + + align:start position:0% +decided that it was acceptable to lose a + + + align:start position:0% +decided that it was acceptable to lose a +few percentage to gain the extra power + + align:start position:0% +few percentage to gain the extra power + + + align:start position:0% +few percentage to gain the extra power +um they also wanted a motor that weighed + + align:start position:0% +um they also wanted a motor that weighed + + + align:start position:0% +um they also wanted a motor that weighed +less than 30 kg and you also had to + + align:start position:0% +less than 30 kg and you also had to + + + align:start position:0% +less than 30 kg and you also had to +interface an evc2 200 controller this + + align:start position:0% +interface an evc2 200 controller this + + + align:start position:0% +interface an evc2 200 controller this +controller is actually the NGM + + align:start position:0% +controller is actually the NGM + + + align:start position:0% +controller is actually the NGM +controller uh we learned later that + + align:start position:0% +controller uh we learned later that + + + align:start position:0% +controller uh we learned later that +there were some limitations to that uh + + align:start position:0% +there were some limitations to that uh + + + align:start position:0% +there were some limitations to that uh +we also wanted an acceleration from 0 to + + align:start position:0% +we also wanted an acceleration from 0 to + + + align:start position:0% +we also wanted an acceleration from 0 to +60 M hour in 15 seconds to give you a + + align:start position:0% +60 M hour in 15 seconds to give you a + + + align:start position:0% +60 M hour in 15 seconds to give you a +rough idea the too previous can do in + + align:start position:0% +rough idea the too previous can do in + + + align:start position:0% +rough idea the too previous can do in +about 12 seconds so we're on par with + + align:start position:0% +about 12 seconds so we're on par with + + + align:start position:0% +about 12 seconds so we're on par with +them um also Tor with speed variation + + align:start position:0% +them um also Tor with speed variation + + + align:start position:0% +them um also Tor with speed variation +and we're powered by electricity uh we + + align:start position:0% +and we're powered by electricity uh we + + + align:start position:0% +and we're powered by electricity uh we +have batteries we can be supplied by + + align:start position:0% +have batteries we can be supplied by + + + align:start position:0% +have batteries we can be supplied by +solar or plug into + + align:start position:0% +solar or plug into + + + align:start position:0% +solar or plug into +the and our constraints start with the + + align:start position:0% +the and our constraints start with the + + + align:start position:0% +the and our constraints start with the +physical constraints where basically we + + align:start position:0% +physical constraints where basically we + + + align:start position:0% +physical constraints where basically we +had to fit into this eyebolt and we also + + align:start position:0% +had to fit into this eyebolt and we also + + + align:start position:0% +had to fit into this eyebolt and we also +had a volume constraint because we + + align:start position:0% +had a volume constraint because we + + + align:start position:0% +had a volume constraint because we +couldn't make the motor uh prohibitively + + align:start position:0% +couldn't make the motor uh prohibitively + + + align:start position:0% +couldn't make the motor uh prohibitively +large because the wheel feature here had + + align:start position:0% +large because the wheel feature here had + + + align:start position:0% +large because the wheel feature here had +a certain diameter um also the torque + + align:start position:0% +a certain diameter um also the torque + + + align:start position:0% +a certain diameter um also the torque +couldn't surpass how much this could + + align:start position:0% +couldn't surpass how much this could + + + align:start position:0% +couldn't surpass how much this could +hold + + align:start position:0% +hold + + + align:start position:0% +hold +and also the EVC 200 which is one uh one + + align:start position:0% +and also the EVC 200 which is one uh one + + + align:start position:0% +and also the EVC 200 which is one uh one +era we did not realize at first but it + + align:start position:0% +era we did not realize at first but it + + + align:start position:0% +era we did not realize at first but it +could only Supply approximately 3.4 Kow + + align:start position:0% +could only Supply approximately 3.4 Kow + + + align:start position:0% +could only Supply approximately 3.4 Kow +continuous unfortunately we learned this + + align:start position:0% +continuous unfortunately we learned this + + + align:start position:0% +continuous unfortunately we learned this +a little bit too + + align:start position:0% +a little bit too + + + align:start position:0% +a little bit too +late can you say that again just that + + align:start position:0% +late can you say that again just that + + + align:start position:0% +late can you say that again just that +last s well we we learned it a little + + align:start position:0% +last s well we we learned it a little + + + align:start position:0% +last s well we we learned it a little +bit too late after we we accepted the + + align:start position:0% +bit too late after we we accepted the + + + align:start position:0% +bit too late after we we accepted the +VDS they handed down their requirements + + align:start position:0% +VDS they handed down their requirements + + + align:start position:0% +VDS they handed down their requirements +when they said to use the NGM controller + + align:start position:0% +when they said to use the NGM controller + + + align:start position:0% +when they said to use the NGM controller +but through our research we found out + + align:start position:0% +but through our research we found out + + + align:start position:0% +but through our research we found out +that it could Supply 8 KW Peak but not + + align:start position:0% +that it could Supply 8 KW Peak but not + + + align:start position:0% +that it could Supply 8 KW Peak but not +continuous only approximately 4 Kow + + align:start position:0% +continuous only approximately 4 Kow + + + align:start position:0% +continuous only approximately 4 Kow +continuous basically to meet the + + align:start position:0% +continuous basically to meet the + + + align:start position:0% +continuous basically to meet the +requirements that were given to us we + + align:start position:0% +requirements that were given to us we + + + align:start position:0% +requirements that were given to us we +would have to have designed a completely + + align:start position:0% +would have to have designed a completely + + + align:start position:0% +would have to have designed a completely +new uh digital brushless motor + + align:start position:0% +new uh digital brushless motor + + + align:start position:0% +new uh digital brushless motor +controller which is like from what we + + align:start position:0% +controller which is like from what we + + + align:start position:0% +controller which is like from what we +learned like a 2-year process if you + + align:start position:0% +learned like a 2-year process if you + + + align:start position:0% +learned like a 2-year process if you +want to get a really good one um in the + + align:start position:0% +want to get a really good one um in the + + + align:start position:0% +want to get a really good one um in the +lecture so that was uh we would had to + + align:start position:0% +lecture so that was uh we would had to + + + align:start position:0% +lecture so that was uh we would had to +make a decision uh whether to go for + + align:start position:0% +make a decision uh whether to go for + + + align:start position:0% +make a decision uh whether to go for +long term or a motor that wouldn't meet + + align:start position:0% +long term or a motor that wouldn't meet + + + align:start position:0% +long term or a motor that wouldn't meet +the requirements they gave us because it + + align:start position:0% +the requirements they gave us because it + + + align:start position:0% +the requirements they gave us because it +wasn't + + align:start position:0% +wasn't + + + align:start position:0% +wasn't +feasible okay + + align:start position:0% +feasible okay + + + align:start position:0% +feasible okay +preliminary design choices in the world + + align:start position:0% +preliminary design choices in the world + + + align:start position:0% +preliminary design choices in the world +of electric motors there's uh a lot of + + align:start position:0% +of electric motors there's uh a lot of + + + align:start position:0% +of electric motors there's uh a lot of +different uh selections you have to make + + align:start position:0% +different uh selections you have to make + + + align:start position:0% +different uh selections you have to make +right away lots of different uh motor + + align:start position:0% +right away lots of different uh motor + + + align:start position:0% +right away lots of different uh motor +types General Motors and we needed to + + align:start position:0% +types General Motors and we needed to + + + align:start position:0% +types General Motors and we needed to +decide just based on Research not + + align:start position:0% +decide just based on Research not + + + align:start position:0% +decide just based on Research not +talking about any design variables like + + align:start position:0% +talking about any design variables like + + + align:start position:0% +talking about any design variables like +pool numbers and such but just the vague + + align:start position:0% +pool numbers and such but just the vague + + + align:start position:0% +pool numbers and such but just the vague +idea of what kind of engine or motor we + + align:start position:0% +idea of what kind of engine or motor we + + + align:start position:0% +idea of what kind of engine or motor we +wanted to design so we started out just + + align:start position:0% +wanted to design so we started out just + + + align:start position:0% +wanted to design so we started out just +tacking this with research and looking + + align:start position:0% +tacking this with research and looking + + + align:start position:0% +tacking this with research and looking +at the field and looking at our + + align:start position:0% +at the field and looking at our + + + align:start position:0% +at the field and looking at our +requirements and deciding okay what fits + + align:start position:0% +requirements and deciding okay what fits + + + align:start position:0% +requirements and deciding okay what fits +what is going to make sense to design + + align:start position:0% +what is going to make sense to design + + + align:start position:0% +what is going to make sense to design +here so basically why did we decide + + align:start position:0% +here so basically why did we decide + + + align:start position:0% +here so basically why did we decide +designed a three-phase axial Gap + + align:start position:0% +designed a three-phase axial Gap + + + align:start position:0% +designed a three-phase axial Gap +double-sided slotted surface mounted + + align:start position:0% +double-sided slotted surface mounted + + + align:start position:0% +double-sided slotted surface mounted +brushless DC motor now it's basically + + align:start position:0% +brushless DC motor now it's basically + + + align:start position:0% +brushless DC motor now it's basically +all decided with no optimization these + + align:start position:0% +all decided with no optimization these + + + align:start position:0% +all decided with no optimization these +are just general ideas testing um first + + align:start position:0% +are just general ideas testing um first + + + align:start position:0% +are just general ideas testing um first +off the brushless home motor compared to + + align:start position:0% +off the brushless home motor compared to + + + align:start position:0% +off the brushless home motor compared to +the brush home motor which is just the + + align:start position:0% +the brush home motor which is just the + + + align:start position:0% +the brush home motor which is just the +brushes on the motor uh brush sub Motors + + align:start position:0% +brushes on the motor uh brush sub Motors + + + align:start position:0% +brushes on the motor uh brush sub Motors +are more uh standard more typical you + + align:start position:0% +are more uh standard more typical you + + + align:start position:0% +are more uh standard more typical you +see them more often brushless is + + align:start position:0% +see them more often brushless is + + + align:start position:0% +see them more often brushless is +something that's come up more in the + + align:start position:0% +something that's come up more in the + + + align:start position:0% +something that's come up more in the +last like 15 years or so um there is a + + align:start position:0% +last like 15 years or so um there is a + + + align:start position:0% +last like 15 years or so um there is a +lot of advantages to brushless motors uh + + align:start position:0% +lot of advantages to brushless motors uh + + + align:start position:0% +lot of advantages to brushless motors uh +one being higher efficiency and + + align:start position:0% +one being higher efficiency and + + + align:start position:0% +one being higher efficiency and +reliability because you reduce the + + align:start position:0% +reliability because you reduce the + + + align:start position:0% +reliability because you reduce the +electromatic interference that's the + + align:start position:0% +electromatic interference that's the + + + align:start position:0% +electromatic interference that's the +main reason why people use them and why + + align:start position:0% +main reason why people use them and why + + + align:start position:0% +main reason why people use them and why +they become more prevalent in the last + + align:start position:0% +they become more prevalent in the last + + + align:start position:0% +they become more prevalent in the last +15 or so years you also reduce the noise + + align:start position:0% +15 or so years you also reduce the noise + + + align:start position:0% +15 or so years you also reduce the noise +because you don't have the brushes + + align:start position:0% +because you don't have the brushes + + + align:start position:0% +because you don't have the brushes +obviously uh and you have a longer life + + align:start position:0% +obviously uh and you have a longer life + + + align:start position:0% +obviously uh and you have a longer life +power because you don't have brushes + + align:start position:0% +power because you don't have brushes + + + align:start position:0% +power because you don't have brushes +you're not going to have that erosion + + align:start position:0% +you're not going to have that erosion + + + align:start position:0% +you're not going to have that erosion +Factor after 5 or 10 years it's going to + + align:start position:0% +Factor after 5 or 10 years it's going to + + + align:start position:0% +Factor after 5 or 10 years it's going to +limit your engine so you have a much + + align:start position:0% +limit your engine so you have a much + + + align:start position:0% +limit your engine so you have a much +longer lifetime which is another one of + + align:start position:0% +longer lifetime which is another one of + + + align:start position:0% +longer lifetime which is another one of +the downstream goals that we have in the + + align:start position:0% +the downstream goals that we have in the + + + align:start position:0% +the downstream goals that we have in the +general electrical vehicle concept going + + align:start position:0% +general electrical vehicle concept going + + + align:start position:0% +general electrical vehicle concept going +be cheaper lastly um it is much more + + align:start position:0% +be cheaper lastly um it is much more + + + align:start position:0% +be cheaper lastly um it is much more +difficult to control like we just talked + + align:start position:0% +difficult to control like we just talked + + + align:start position:0% +difficult to control like we just talked +about the controller uh with digital + + align:start position:0% +about the controller uh with digital + + + align:start position:0% +about the controller uh with digital +control it's become a little bit easier + + align:start position:0% +control it's become a little bit easier + + + align:start position:0% +control it's become a little bit easier +but because of the way interfaces work + + align:start position:0% +but because of the way interfaces work + + + align:start position:0% +but because of the way interfaces work +with the uh the pulse currents and the + + align:start position:0% +with the uh the pulse currents and the + + + align:start position:0% +with the uh the pulse currents and the +phases it becomes much more difficult to + + align:start position:0% +phases it becomes much more difficult to + + + align:start position:0% +phases it becomes much more difficult to +control and that's a much more uh larg + + align:start position:0% +control and that's a much more uh larg + + + align:start position:0% +control and that's a much more uh larg +investment should you need to design + + align:start position:0% +investment should you need to design + + + align:start position:0% +investment should you need to design +your controller that you have to + + align:start position:0% +your controller that you have to + + + align:start position:0% +your controller that you have to +consider uh for three phase basically + + align:start position:0% +consider uh for three phase basically + + + align:start position:0% +consider uh for three phase basically +that is talking about when you're going + + align:start position:0% +that is talking about when you're going + + + align:start position:0% +that is talking about when you're going +to pulse your currents and how many + + align:start position:0% +to pulse your currents and how many + + + align:start position:0% +to pulse your currents and how many +pulse currents you're going to have at a + + align:start position:0% +pulse currents you're going to have at a + + + align:start position:0% +pulse currents you're going to have at a +minimum you can have two phase because + + align:start position:0% +minimum you can have two phase because + + + align:start position:0% +minimum you can have two phase because +if you only have one phase you're going + + align:start position:0% +if you only have one phase you're going + + + align:start position:0% +if you only have one phase you're going +to turn your you're going to turn your + + align:start position:0% +to turn your you're going to turn your + + + align:start position:0% +to turn your you're going to turn your +magnets and it's going to stop you're + + align:start position:0% +magnets and it's going to stop you're + + + align:start position:0% +magnets and it's going to stop you're +going to have nothing you can do uh two + + align:start position:0% +going to have nothing you can do uh two + + + align:start position:0% +going to have nothing you can do uh two +phase though the problem you into is if + + align:start position:0% +phase though the problem you into is if + + + align:start position:0% +phase though the problem you into is if +you pulse one of the currents and it + + align:start position:0% +you pulse one of the currents and it + + + align:start position:0% +you pulse one of the currents and it +happens to stop in a position where it's + + align:start position:0% +happens to stop in a position where it's + + + align:start position:0% +happens to stop in a position where it's +lined up perfectly with the magnet at 0° + + align:start position:0% +lined up perfectly with the magnet at 0° + + + align:start position:0% +lined up perfectly with the magnet at 0° +when you try to start your engine you're + + align:start position:0% +when you try to start your engine you're + + + align:start position:0% +when you try to start your engine you're +going to have no net uh magnet flux and + + align:start position:0% +going to have no net uh magnet flux and + + + align:start position:0% +going to have no net uh magnet flux and +you're going to have no ability to start + + align:start position:0% +you're going to have no ability to start + + + align:start position:0% +you're going to have no ability to start +your engine so there's very poor + + align:start position:0% +your engine so there's very poor + + + align:start position:0% +your engine so there's very poor +starting condition so three-phase + + align:start position:0% +starting condition so three-phase + + + align:start position:0% +starting condition so three-phase +typically is represented as a minimum + + align:start position:0% +typically is represented as a minimum + + + align:start position:0% +typically is represented as a minimum +for a uh smooth torque uh car having + + align:start position:0% +for a uh smooth torque uh car having + + + align:start position:0% +for a uh smooth torque uh car having +three phases separates the phases by + + align:start position:0% +three phases separates the phases by + + + align:start position:0% +three phases separates the phases by +120° so when you start your engine and + + align:start position:0% +120° so when you start your engine and + + + align:start position:0% +120° so when you start your engine and +the way it puls you're pulsing two at a + + align:start position:0% +the way it puls you're pulsing two at a + + + align:start position:0% +the way it puls you're pulsing two at a +time and one's off and you get a really + + align:start position:0% +time and one's off and you get a really + + + align:start position:0% +time and one's off and you get a really +really smooth torque uh that's really + + align:start position:0% +really smooth torque uh that's really + + + align:start position:0% +really smooth torque uh that's really +good for motor application because you + + align:start position:0% +good for motor application because you + + + align:start position:0% +good for motor application because you +have no torque Ripple which decreases + + align:start position:0% +have no torque Ripple which decreases + + + align:start position:0% +have no torque Ripple which decreases +your structal resonance considerably and + + align:start position:0% +your structal resonance considerably and + + + align:start position:0% +your structal resonance considerably and +you're going to have a lot less + + align:start position:0% +you're going to have a lot less + + + align:start position:0% +you're going to have a lot less +mechanical stress once again increasing + + align:start position:0% +mechanical stress once again increasing + + + align:start position:0% +mechanical stress once again increasing +the reliability and lifetime of the + + align:start position:0% +the reliability and lifetime of the + + + align:start position:0% +the reliability and lifetime of the +engine which is a big deal for us + + align:start position:0% +engine which is a big deal for us + + + align:start position:0% +engine which is a big deal for us +generally when you increase your phases + + align:start position:0% +generally when you increase your phases + + + align:start position:0% +generally when you increase your phases +you're going to increase the utilization + + align:start position:0% +you're going to increase the utilization + + + align:start position:0% +you're going to increase the utilization +of materials you're using in the motor + + align:start position:0% +of materials you're using in the motor + + + align:start position:0% +of materials you're using in the motor +that's a good thing but should you keep + + align:start position:0% +that's a good thing but should you keep + + + align:start position:0% +that's a good thing but should you keep +going for five six phases yeah you're + + align:start position:0% +going for five six phases yeah you're + + + align:start position:0% +going for five six phases yeah you're +going to get better utilization and + + align:start position:0% +going to get better utilization and + + + align:start position:0% +going to get better utilization and +lower percent losses but you're going to + + align:start position:0% +lower percent losses but you're going to + + + align:start position:0% +lower percent losses but you're going to +have a lot more leads a lot more + + align:start position:0% +have a lot more leads a lot more + + + align:start position:0% +have a lot more leads a lot more +transistors it's going to become vastly + + align:start position:0% +transistors it's going to become vastly + + + align:start position:0% +transistors it's going to become vastly +complex the control is going to be a + + align:start position:0% +complex the control is going to be a + + + align:start position:0% +complex the control is going to be a +nightmare and it's going to be much more + + align:start position:0% +nightmare and it's going to be much more + + + align:start position:0% +nightmare and it's going to be much more +expensive so that's why 3phase was + + align:start position:0% +expensive so that's why 3phase was + + + align:start position:0% +expensive so that's why 3phase was +chosen so couple more uh couple more + + align:start position:0% +chosen so couple more uh couple more + + + align:start position:0% +chosen so couple more uh couple more +decisions we need to make about the + + align:start position:0% +decisions we need to make about the + + + align:start position:0% +decisions we need to make about the +motor uh for brushless motors the + + align:start position:0% +motor uh for brushless motors the + + + align:start position:0% +motor uh for brushless motors the +difference between a brushless motor and + + align:start position:0% +difference between a brushless motor and + + + align:start position:0% +difference between a brushless motor and +a brush motor is uh you reverse where + + align:start position:0% +a brush motor is uh you reverse where + + + align:start position:0% +a brush motor is uh you reverse where +the coils and magnets are on a brush + + align:start position:0% +the coils and magnets are on a brush + + + align:start position:0% +the coils and magnets are on a brush +motor the coils are on the the rotor and + + align:start position:0% +motor the coils are on the the rotor and + + + align:start position:0% +motor the coils are on the the rotor and +the as the rotor turns it switches its + + align:start position:0% +the as the rotor turns it switches its + + + align:start position:0% +the as the rotor turns it switches its +own current with the brushes uh + + align:start position:0% +own current with the brushes uh + + + align:start position:0% +own current with the brushes uh +brushless motor is usually so the + + align:start position:0% +brushless motor is usually so the + + + align:start position:0% +brushless motor is usually so the +permanent magnets are on the rotor and + + align:start position:0% +permanent magnets are on the rotor and + + + align:start position:0% +permanent magnets are on the rotor and +the stator has the coils and you just + + align:start position:0% +the stator has the coils and you just + + + align:start position:0% +the stator has the coils and you just +pulse current through transistors and + + align:start position:0% +pulse current through transistors and + + + align:start position:0% +pulse current through transistors and +stuff so um you get basically two + + align:start position:0% +stuff so um you get basically two + + + align:start position:0% +stuff so um you get basically two +configurations that are commonly + + align:start position:0% +configurations that are commonly + + + align:start position:0% +configurations that are commonly +produced you can make a radial gas motor + + align:start position:0% +produced you can make a radial gas motor + + + align:start position:0% +produced you can make a radial gas motor +uh radial flux modities where you have + + align:start position:0% +uh radial flux modities where you have + + + align:start position:0% +uh radial flux modities where you have +the rotor in the middle magnets facing + + align:start position:0% +the rotor in the middle magnets facing + + + align:start position:0% +the rotor in the middle magnets facing +outward and stator coils ranged around + + align:start position:0% +outward and stator coils ranged around + + + align:start position:0% +outward and stator coils ranged around +uh the other the design we chose is an + + align:start position:0% +uh the other the design we chose is an + + + align:start position:0% +uh the other the design we chose is an +actual fluxus motor which is uh + + align:start position:0% +actual fluxus motor which is uh + + + align:start position:0% +actual fluxus motor which is uh +basically two discs next to + + align:start position:0% +basically two discs next to + + + align:start position:0% +basically two discs next to +one with the Perman magnets rotates one + + align:start position:0% +one with the Perman magnets rotates one + + + align:start position:0% +one with the Perman magnets rotates one +the St stay still uh we went with actual + + align:start position:0% +the St stay still uh we went with actual + + + align:start position:0% +the St stay still uh we went with actual +Gap mostly because of spatial problems + + align:start position:0% +Gap mostly because of spatial problems + + + align:start position:0% +Gap mostly because of spatial problems +um if you want to make a radial flux + + align:start position:0% +um if you want to make a radial flux + + + align:start position:0% +um if you want to make a radial flux +Motors uh more powerful you need to + + align:start position:0% +Motors uh more powerful you need to + + + align:start position:0% +Motors uh more powerful you need to +basically extend it lengthwise on the + + align:start position:0% +basically extend it lengthwise on the + + + align:start position:0% +basically extend it lengthwise on the +cylinder to get more surface area + + align:start position:0% +cylinder to get more surface area + + + align:start position:0% +cylinder to get more surface area +between the St and the motor but uh we + + align:start position:0% +between the St and the motor but uh we + + + align:start position:0% +between the St and the motor but uh we +you know we can't go too wide and we + + align:start position:0% +you know we can't go too wide and we + + + align:start position:0% +you know we can't go too wide and we +keep the wheel still in the car so we + + align:start position:0% +keep the wheel still in the car so we + + + align:start position:0% +keep the wheel still in the car so we +went with an actual Gap motor we can + + align:start position:0% +went with an actual Gap motor we can + + + align:start position:0% +went with an actual Gap motor we can +just increase the uh diameter if we want + + align:start position:0% +just increase the uh diameter if we want + + + align:start position:0% +just increase the uh diameter if we want +and + + align:start position:0% +and + + + align:start position:0% +and +it'll we increase the surface area that + + align:start position:0% +it'll we increase the surface area that + + + align:start position:0% +it'll we increase the surface area that +way um we're basically going for power + + align:start position:0% +way um we're basically going for power + + + align:start position:0% +way um we're basically going for power +density here so we went with two sters + + align:start position:0% +density here so we went with two sters + + + align:start position:0% +density here so we went with two sters +one the either side of the rotor again + + align:start position:0% +one the either side of the rotor again + + + align:start position:0% +one the either side of the rotor again +we're just we get more surface area + + align:start position:0% +we're just we get more surface area + + + align:start position:0% +we're just we get more surface area +right between the mags and the St um + + align:start position:0% +right between the mags and the St um + + + align:start position:0% +right between the mags and the St um +this + + align:start position:0% +this + + + align:start position:0% +this +is setting it up like this is a lot more + + align:start position:0% +is setting it up like this is a lot more + + + align:start position:0% +is setting it up like this is a lot more +efficient lot of Radix Motors that are + + align:start position:0% +efficient lot of Radix Motors that are + + + align:start position:0% +efficient lot of Radix Motors that are +often used for like + + align:start position:0% + + + + align:start position:0% + +St uh sled Armature so you can build uh + + align:start position:0% +St uh sled Armature so you can build uh + + + align:start position:0% +St uh sled Armature so you can build uh +you can build your stator it basically + + align:start position:0% +you can build your stator it basically + + + align:start position:0% +you can build your stator it basically +just has to be a coil so you can pulse + + align:start position:0% +just has to be a coil so you can pulse + + + align:start position:0% +just has to be a coil so you can pulse +it like an electromagnet but what you + + align:start position:0% +it like an electromagnet but what you + + + align:start position:0% +it like an electromagnet but what you +often do with electr magets is put + + align:start position:0% +often do with electr magets is put + + + align:start position:0% +often do with electr magets is put +something Paris in the middle to get a + + align:start position:0% +something Paris in the middle to get a + + + align:start position:0% +something Paris in the middle to get a +much stronger field right there in the + + align:start position:0% +much stronger field right there in the + + + align:start position:0% +much stronger field right there in the +middle um so rather than just embed + + align:start position:0% +middle um so rather than just embed + + + align:start position:0% +middle um so rather than just embed +coils in epoxy or something uh we we put + + align:start position:0% +coils in epoxy or something uh we we put + + + align:start position:0% +coils in epoxy or something uh we we put +slots uh basically paramagnetic + + align:start position:0% +slots uh basically paramagnetic + + + align:start position:0% +slots uh basically paramagnetic +extensions to the structure through the + + align:start position:0% +extensions to the structure through the + + + align:start position:0% +extensions to the structure through the +through the St cles so what these let + + align:start position:0% +through the St cles so what these let + + + align:start position:0% +through the St cles so what these let +you do is um you can have them go right + + align:start position:0% +you do is um you can have them go right + + + align:start position:0% +you do is um you can have them go right +up to the surface of the per so you have + + align:start position:0% +up to the surface of the per so you have + + + align:start position:0% +up to the surface of the per so you have +a really small air gap for the field you + + align:start position:0% +a really small air gap for the field you + + + align:start position:0% +a really small air gap for the field you +get a lot more power that way and it's + + align:start position:0% +get a lot more power that way and it's + + + align:start position:0% +get a lot more power that way and it's +also much more mechanically + + align:start position:0% +also much more mechanically + + + align:start position:0% +also much more mechanically +uh structurally sound I guess to have uh + + align:start position:0% +uh structurally sound I guess to have uh + + + align:start position:0% +uh structurally sound I guess to have uh +steel basically reinforcing your whole + + align:start position:0% +steel basically reinforcing your whole + + + align:start position:0% +steel basically reinforcing your whole +state structure so uh setting it up with + + align:start position:0% +state structure so uh setting it up with + + + align:start position:0% +state structure so uh setting it up with +a bunch of a bunch of slots uh is + + align:start position:0% +a bunch of a bunch of slots uh is + + + align:start position:0% +a bunch of a bunch of slots uh is +probably going to get us a lot more + + align:start position:0% +probably going to get us a lot more + + + align:start position:0% +probably going to get us a lot more +power it'll uh be a lot stronger the it + + align:start position:0% +power it'll uh be a lot stronger the it + + + align:start position:0% +power it'll uh be a lot stronger the it +does have a couple of disadvantages with + + align:start position:0% +does have a couple of disadvantages with + + + align:start position:0% +does have a couple of disadvantages with +regard to efficiency especially starting + + align:start position:0% +regard to efficiency especially starting + + + align:start position:0% +regard to efficiency especially starting +up you can get a lot of + + align:start position:0% +up you can get a lot of + + + align:start position:0% +up you can get a lot of +which is uh it's not moving fast enough + + align:start position:0% +which is uh it's not moving fast enough + + + align:start position:0% +which is uh it's not moving fast enough +for it to act continuous so it P + + align:start position:0% +for it to act continuous so it P + + + align:start position:0% +for it to act continuous so it P +specific slots and can holds can sort of + + align:start position:0% +specific slots and can holds can sort of + + + align:start position:0% +specific slots and can holds can sort of +stick to one another if not switching + + align:start position:0% +stick to one another if not switching + + + align:start position:0% +stick to one another if not switching +fast enough but besides that uh it's not + + align:start position:0% +fast enough but besides that uh it's not + + + align:start position:0% +fast enough but besides that uh it's not +much of a loss of efficiency and it + + align:start position:0% +much of a loss of efficiency and it + + + align:start position:0% +much of a loss of efficiency and it +gives us a lot more power density which + + align:start position:0% +gives us a lot more power density which + + + align:start position:0% +gives us a lot more power density which +is what we going for and surface amount + + align:start position:0% +is what we going for and surface amount + + + align:start position:0% +is what we going for and surface amount +of permanent BS so just way we machine + + align:start position:0% +of permanent BS so just way we machine + + + align:start position:0% +of permanent BS so just way we machine +try B inside + + align:start position:0% +try B inside + + + align:start position:0% +try B inside +structure given the complexity of the + + align:start position:0% +structure given the complexity of the + + + align:start position:0% +structure given the complexity of the +design + + align:start position:0% +design + + + align:start position:0% +design +uh we decided it was prudent to limit + + align:start position:0% +uh we decided it was prudent to limit + + + align:start position:0% +uh we decided it was prudent to limit +the number of design variables and we + + align:start position:0% +the number of design variables and we + + + align:start position:0% +the number of design variables and we +decided that the number of poles theator + + align:start position:0% +decided that the number of poles theator + + + align:start position:0% +decided that the number of poles theator +slots the magnet span magnet grade + + align:start position:0% +slots the magnet span magnet grade + + + align:start position:0% +slots the magnet span magnet grade +magnet skew the number of coil turns and + + align:start position:0% +magnet skew the number of coil turns and + + + align:start position:0% +magnet skew the number of coil turns and +the air gap the primary focus and with + + align:start position:0% +the air gap the primary focus and with + + + align:start position:0% +the air gap the primary focus and with +those variables it gave us this + + align:start position:0% +those variables it gave us this + + + align:start position:0% +those variables it gave us this +handdrawn preliminary sketch and we + + align:start position:0% +handdrawn preliminary sketch and we + + + align:start position:0% +handdrawn preliminary sketch and we +could obtain a fair idea of what we were + + align:start position:0% +could obtain a fair idea of what we were + + + align:start position:0% +could obtain a fair idea of what we were +a going for um to improve on it we have + + align:start position:0% +a going for um to improve on it we have + + + align:start position:0% +a going for um to improve on it we have +to find we could not use solid + + align:start position:0% +to find we could not use solid + + + align:start position:0% +to find we could not use solid +unfortunately because they only did + + align:start position:0% +unfortunately because they only did + + + align:start position:0% +unfortunately because they only did +mechanic + + align:start position:0% +mechanic + + + align:start position:0% +mechanic +finite element analysis we found that we + + align:start position:0% +finite element analysis we found that we + + + align:start position:0% +finite element analysis we found that we +could use Maxwell 3D um unfortunately + + align:start position:0% +could use Maxwell 3D um unfortunately + + + align:start position:0% +could use Maxwell 3D um unfortunately +Maxwell 3D was a program that's not + + align:start position:0% +Maxwell 3D was a program that's not + + + align:start position:0% +Maxwell 3D was a program that's not +supported directly by MIT Isn and we had + + align:start position:0% +supported directly by MIT Isn and we had + + + align:start position:0% +supported directly by MIT Isn and we had +to contact several of Engineers at Ansa + + align:start position:0% +to contact several of Engineers at Ansa + + + align:start position:0% +to contact several of Engineers at Ansa +and also uh one person here my Tran who + + align:start position:0% +and also uh one person here my Tran who + + + align:start position:0% +and also uh one person here my Tran who +would help us but even then we had many + + align:start position:0% +would help us but even then we had many + + + align:start position:0% +would help us but even then we had many +problems and we could not use it to + + align:start position:0% +problems and we could not use it to + + + align:start position:0% +problems and we could not use it to +fullest + + align:start position:0% + + + + align:start position:0% + +capabilities and here uh when we did use + + align:start position:0% +capabilities and here uh when we did use + + + align:start position:0% +capabilities and here uh when we did use +maxo 3D um we couldn't use its + + align:start position:0% +maxo 3D um we couldn't use its + + + align:start position:0% +maxo 3D um we couldn't use its +optimization software but we could plug + + align:start position:0% +optimization software but we could plug + + + align:start position:0% +optimization software but we could plug +in specific values and given that it + + align:start position:0% +in specific values and given that it + + + align:start position:0% +in specific values and given that it +took about I would say half an hour to + + align:start position:0% +took about I would say half an hour to + + + align:start position:0% +took about I would say half an hour to +run one simulation and that simulation + + align:start position:0% +run one simulation and that simulation + + + align:start position:0% +run one simulation and that simulation +was quite limited to about3 seconds or 6 + + align:start position:0% +was quite limited to about3 seconds or 6 + + + align:start position:0% +was quite limited to about3 seconds or 6 +seconds if we ran into the full this + + align:start position:0% +seconds if we ran into the full this + + + align:start position:0% +seconds if we ran into the full this +limit we can only find that these values + + align:start position:0% +limit we can only find that these values + + + align:start position:0% +limit we can only find that these values +were the optimized values where we have + + align:start position:0% +were the optimized values where we have + + + align:start position:0% +were the optimized values where we have +eight poles 18 slots um the mag grade + + align:start position:0% +eight poles 18 slots um the mag grade + + + align:start position:0% +eight poles 18 slots um the mag grade +here is neodium ironon close span of two + + align:start position:0% +here is neodium ironon close span of two + + + align:start position:0% +here is neodium ironon close span of two +air gap of 1 mm stay offset of 15° + + align:start position:0% +air gap of 1 mm stay offset of 15° + + + align:start position:0% +air gap of 1 mm stay offset of 15° +magnet span of 150° magnet skew of one + + align:start position:0% +magnet span of 150° magnet skew of one + + + align:start position:0% +magnet span of 150° magnet skew of one +pitch one slot pitch and a wi D on 2 + + align:start position:0% + + + + align:start position:0% + +mm so we're going to talk about the + + align:start position:0% +mm so we're going to talk about the + + + align:start position:0% +mm so we're going to talk about the +design variables just uh briefly and + + align:start position:0% +design variables just uh briefly and + + + align:start position:0% +design variables just uh briefly and +tell you what they mean and what the + + align:start position:0% +tell you what they mean and what the + + + align:start position:0% +tell you what they mean and what the +optimiz values are going to do for our + + align:start position:0% +optimiz values are going to do for our + + + align:start position:0% +optimiz values are going to do for our +engine in the long term for the full + + align:start position:0% +engine in the long term for the full + + + align:start position:0% +engine in the long term for the full +number um typically you increase the + + align:start position:0% +number um typically you increase the + + + align:start position:0% +number um typically you increase the +pole number to get a smooth torque which + + align:start position:0% +pole number to get a smooth torque which + + + align:start position:0% +pole number to get a smooth torque which +we talked about several times one of the + + align:start position:0% +we talked about several times one of the + + + align:start position:0% +we talked about several times one of the +big the big things we're trying to get + + align:start position:0% +big the big things we're trying to get + + + align:start position:0% +big the big things we're trying to get +for an engine you need a smooth torque + + align:start position:0% +for an engine you need a smooth torque + + + align:start position:0% +for an engine you need a smooth torque +to reduce the stresses on the engine and + + align:start position:0% +to reduce the stresses on the engine and + + + align:start position:0% +to reduce the stresses on the engine and +uh that usually implies a large pull + + align:start position:0% +uh that usually implies a large pull + + + align:start position:0% +uh that usually implies a large pull +count by large a typical engines have + + align:start position:0% +count by large a typical engines have + + + align:start position:0% +count by large a typical engines have +two or four folds so eight actually is + + align:start position:0% +two or four folds so eight actually is + + + align:start position:0% +two or four folds so eight actually is +considered somewhat large it's more + + align:start position:0% +considered somewhat large it's more + + + align:start position:0% +considered somewhat large it's more +standard nowadays than it was about 10 + + align:start position:0% +standard nowadays than it was about 10 + + + align:start position:0% +standard nowadays than it was about 10 +years ago but uh if you increase it past + + align:start position:0% +years ago but uh if you increase it past + + + align:start position:0% +years ago but uh if you increase it past +eight it becomes very complex and once + + align:start position:0% +eight it becomes very complex and once + + + align:start position:0% +eight it becomes very complex and once +again the control becomes a nightmare + + align:start position:0% +again the control becomes a nightmare + + + align:start position:0% +again the control becomes a nightmare +what eight FS to do is it decrease the + + align:start position:0% +what eight FS to do is it decrease the + + + align:start position:0% +what eight FS to do is it decrease the +thickness of the root yolk and the ster + + align:start position:0% +thickness of the root yolk and the ster + + + align:start position:0% +thickness of the root yolk and the ster +yolk so it decreases our overall + + align:start position:0% +yolk so it decreases our overall + + + align:start position:0% +yolk so it decreases our overall +diameter which is good for us that's + + align:start position:0% +diameter which is good for us that's + + + align:start position:0% +diameter which is good for us that's +what we're looking for it minimizes the + + align:start position:0% +what we're looking for it minimizes the + + + align:start position:0% +what we're looking for it minimizes the +flux leakage which uh will decrease the + + align:start position:0% +flux leakage which uh will decrease the + + + align:start position:0% +flux leakage which uh will decrease the +overall I mean increase the overall + + align:start position:0% +overall I mean increase the overall + + + align:start position:0% +overall I mean increase the overall +efficiency once again because you have + + align:start position:0% +efficiency once again because you have + + + align:start position:0% +efficiency once again because you have +less uh increase your power than2 + + align:start position:0% +less uh increase your power than2 + + + align:start position:0% +less uh increase your power than2 +because you're not losing as much of the + + align:start position:0% +because you're not losing as much of the + + + align:start position:0% +because you're not losing as much of the +flux and uh thirdly it increases the + + align:start position:0% +flux and uh thirdly it increases the + + + align:start position:0% +flux and uh thirdly it increases the +actual length of the stator and in + + align:start position:0% +actual length of the stator and in + + + align:start position:0% +actual length of the stator and in +windings which once again is related to + + align:start position:0% +windings which once again is related to + + + align:start position:0% +windings which once again is related to +the efficiency of the engine uh we can + + align:start position:0% +the efficiency of the engine uh we can + + + align:start position:0% +the efficiency of the engine uh we can +increase the efficiency by reducing the + + align:start position:0% +increase the efficiency by reducing the + + + align:start position:0% +increase the efficiency by reducing the +veloc for the Stater slots uh there's + + align:start position:0% +veloc for the Stater slots uh there's + + + align:start position:0% +veloc for the Stater slots uh there's +actually a relationship between Stater + + align:start position:0% +actually a relationship between Stater + + + align:start position:0% +actually a relationship between Stater +slots full number and phase um there's + + align:start position:0% +slots full number and phase um there's + + + align:start position:0% +slots full number and phase um there's +certain fractions that you can and + + align:start position:0% +certain fractions that you can and + + + align:start position:0% +certain fractions that you can and +cannot have and what you want be + + align:start position:0% +cannot have and what you want be + + + align:start position:0% +cannot have and what you want be +fractions of the St pull it needs to + + align:start position:0% +fractions of the St pull it needs to + + + align:start position:0% +fractions of the St pull it needs to +round down it has to do with the coil + + align:start position:0% +round down it has to do with the coil + + + align:start position:0% +round down it has to do with the coil +windings um so basically we chose 18 as + + align:start position:0% +windings um so basically we chose 18 as + + + align:start position:0% +windings um so basically we chose 18 as +a maximum that's pull round down to two + + align:start position:0% +a maximum that's pull round down to two + + + align:start position:0% +a maximum that's pull round down to two +and makes it much much more uh easy to + + align:start position:0% +and makes it much much more uh easy to + + + align:start position:0% +and makes it much much more uh easy to +manufacture you can actually manufacture + + align:start position:0% +manufacture you can actually manufacture + + + align:start position:0% +manufacture you can actually manufacture +this on uh on machines that are actually + + align:start position:0% +this on uh on machines that are actually + + + align:start position:0% +this on uh on machines that are actually +offered M for the the winding turns um + + align:start position:0% +offered M for the the winding turns um + + + align:start position:0% +offered M for the the winding turns um +if you have it higher than two the three + + align:start position:0% +if you have it higher than two the three + + + align:start position:0% +if you have it higher than two the three +or four you're going to need some very + + align:start position:0% +or four you're going to need some very + + + align:start position:0% +or four you're going to need some very +expensive uh machines from what I + + align:start position:0% +expensive uh machines from what I + + + align:start position:0% +expensive uh machines from what I +understand let me ask you why didn't you + + align:start position:0% +understand let me ask you why didn't you + + + align:start position:0% +understand let me ask you why didn't you +go to 16 slots which was sort of around + + align:start position:0% +go to 16 slots which was sort of around + + + align:start position:0% +go to 16 slots which was sort of around +you know there's actually a table um + + align:start position:0% +you know there's actually a table um + + + align:start position:0% +you know there's actually a table um +that allows you and 16 / 8 gives you two + + align:start position:0% +that allows you and 16 / 8 gives you two + + + align:start position:0% +that allows you and 16 / 8 gives you two +but you don't want it to be integer + + align:start position:0% +but you don't want it to be integer + + + align:start position:0% +but you don't want it to be integer +because if it's an integer or the way it + + align:start position:0% +because if it's an integer or the way it + + + align:start position:0% +because if it's an integer or the way it +lines up with the phases you can have + + align:start position:0% +lines up with the phases you can have + + + align:start position:0% +lines up with the phases you can have +Cog problems it needs to be a fraction + + align:start position:0% +Cog problems it needs to be a fraction + + + align:start position:0% +Cog problems it needs to be a fraction +you want it to be slightly offset + + align:start position:0% +you want it to be slightly offset + + + align:start position:0% +you want it to be slightly offset +because if it's perfectly round + + align:start position:0% +because if it's perfectly round + + + align:start position:0% +because if it's perfectly round +especially if it's an even number then + + align:start position:0% +especially if it's an even number then + + + align:start position:0% +especially if it's an even number then +you're going to have it line up + + align:start position:0% +you're going to have it line up + + + align:start position:0% +you're going to have it line up +perfectly and then the poles and Staters + + align:start position:0% +perfectly and then the poles and Staters + + + align:start position:0% +perfectly and then the poles and Staters +are going to want to just sit there + + align:start position:0% +are going to want to just sit there + + + align:start position:0% +are going to want to just sit there +because they're going to start like in + + align:start position:0% +because they're going to start like in + + + align:start position:0% +because they're going to start like in +line with each other so to speak you + + align:start position:0% +line with each other so to speak you + + + align:start position:0% +line with each other so to speak you +want to fraction so it be slightly + + align:start position:0% +want to fraction so it be slightly + + + align:start position:0% +want to fraction so it be slightly +opposite that that especially during the + + align:start position:0% +opposite that that especially during the + + + align:start position:0% +opposite that that especially during the +start the thing where you have like if + + align:start position:0% +start the thing where you have like if + + + align:start position:0% +start the thing where you have like if +you have two phases it can get stuck + + align:start position:0% +you have two phases it can get stuck + + + align:start position:0% +you have two phases it can get stuck +right there same thing you don't want + + align:start position:0% +right there same thing you don't want + + + align:start position:0% +right there same thing you don't want +everything to fit just it was actually a + + align:start position:0% +everything to fit just it was actually a + + + align:start position:0% +everything to fit just it was actually a +table so we were you know we were + + align:start position:0% +table so we were you know we were + + + align:start position:0% +table so we were you know we were +limited it was actually good for this + + align:start position:0% +limited it was actually good for this + + + align:start position:0% +limited it was actually good for this +cuz we were limited to so many things we + + align:start position:0% +cuz we were limited to so many things we + + + align:start position:0% +cuz we were limited to so many things we +can pick so we actually run a simulation + + align:start position:0% +can pick so we actually run a simulation + + + align:start position:0% +can pick so we actually run a simulation +it wasn't too much of a nightmare as + + align:start position:0% +it wasn't too much of a nightmare as + + + align:start position:0% +it wasn't too much of a nightmare as +opposed to a design variable where + + align:start position:0% +opposed to a design variable where + + + align:start position:0% +opposed to a design variable where +you're looking over a range you can pick + + align:start position:0% +you're looking over a range you can pick + + + align:start position:0% +you're looking over a range you can pick +a a step size where that was much more + + align:start position:0% +a a step size where that was much more + + + align:start position:0% +a a step size where that was much more +difficult for us op ready to do them by + + align:start position:0% +difficult for us op ready to do them by + + + align:start position:0% +difficult for us op ready to do them by +manual inputs so uh for stair slots once + + align:start position:0% +manual inputs so uh for stair slots once + + + align:start position:0% +manual inputs so uh for stair slots once +again it's related to pH number and the + + align:start position:0% +again it's related to pH number and the + + + align:start position:0% +again it's related to pH number and the +and the cogn uh 18 slots gave the qu 2 + + align:start position:0% +and the cogn uh 18 slots gave the qu 2 + + + align:start position:0% +and the cogn uh 18 slots gave the qu 2 +which is EAS manufacturer it reduced the + + align:start position:0% +which is EAS manufacturer it reduced the + + + align:start position:0% +which is EAS manufacturer it reduced the +cogn which is good because it was a + + align:start position:0% +cogn which is good because it was a + + + align:start position:0% +cogn which is good because it was a +fraction and I reduced the length of + + align:start position:0% +fraction and I reduced the length of + + + align:start position:0% +fraction and I reduced the length of +ning once again so once again it uh + + align:start position:0% +ning once again so once again it uh + + + align:start position:0% +ning once again so once again it uh +lowered the copper losses the third + + align:start position:0% +lowered the copper losses the third + + + align:start position:0% +lowered the copper losses the third +design was air graph length um it was a + + align:start position:0% +design was air graph length um it was a + + + align:start position:0% +design was air graph length um it was a +range so we picked I think three + + align:start position:0% +range so we picked I think three + + + align:start position:0% +range so we picked I think three +different ones uh and we ended up siding + + align:start position:0% +different ones uh and we ended up siding + + + align:start position:0% +different ones uh and we ended up siding +on 1 mm generally speaking increasing + + align:start position:0% +on 1 mm generally speaking increasing + + + align:start position:0% +on 1 mm generally speaking increasing +the air graph uh you're going to have + + align:start position:0% +the air graph uh you're going to have + + + align:start position:0% +the air graph uh you're going to have +more flux losses once again Lower power + + align:start position:0% +more flux losses once again Lower power + + + align:start position:0% +more flux losses once again Lower power +density and less efficiency just because + + align:start position:0% +density and less efficiency just because + + + align:start position:0% +density and less efficiency just because +there's more space for things to you + + align:start position:0% +there's more space for things to you + + + align:start position:0% +there's more space for things to you +lost and to make it too small though + + align:start position:0% +lost and to make it too small though + + + align:start position:0% +lost and to make it too small though +you're not going to have enough room for + + align:start position:0% +you're not going to have enough room for + + + align:start position:0% +you're not going to have enough room for +the torque to develop and you're going + + align:start position:0% +the torque to develop and you're going + + + align:start position:0% +the torque to develop and you're going +to have L + + align:start position:0% +to have L + + + align:start position:0% +to have L +power minute + + align:start position:0% +power minute + + + align:start position:0% +power minute +warning okay so just quickly + + align:start position:0% +warning okay so just quickly + + + align:start position:0% +warning okay so just quickly +other mag grade St offset mag skew the + + align:start position:0% +other mag grade St offset mag skew the + + + align:start position:0% +other mag grade St offset mag skew the +two magnet skew and span are just the + + align:start position:0% +two magnet skew and span are just the + + + align:start position:0% +two magnet skew and span are just the +orientation of the magnet inside the + + align:start position:0% +orientation of the magnet inside the + + + align:start position:0% +orientation of the magnet inside the +rotor and we already mentioned wire + + align:start position:0% +rotor and we already mentioned wire + + + align:start position:0% +rotor and we already mentioned wire +diameter and coil span these all have + + align:start position:0% +diameter and coil span these all have + + + align:start position:0% +diameter and coil span these all have +slight things that they do basically we + + align:start position:0% +slight things that they do basically we + + + align:start position:0% +slight things that they do basically we +just pick three values based on Research + + align:start position:0% +just pick three values based on Research + + + align:start position:0% +just pick three values based on Research +that we did and then inut + + align:start position:0% + + + + align:start position:0% + +uh for the stor slot design you can you + + align:start position:0% +uh for the stor slot design you can you + + + align:start position:0% +uh for the stor slot design you can you +can include these design variables uh + + align:start position:0% +can include these design variables uh + + + align:start position:0% +can include these design variables uh +for us it would have been a nightmare + + align:start position:0% +for us it would have been a nightmare + + + align:start position:0% +for us it would have been a nightmare +because these things have so many + + align:start position:0% +because these things have so many + + + align:start position:0% +because these things have so many +variables just for each St slot we chose + + align:start position:0% +variables just for each St slot we chose + + + align:start position:0% +variables just for each St slot we chose +like we have 18 of these going around + + align:start position:0% +like we have 18 of these going around + + + align:start position:0% +like we have 18 of these going around +because we have slotted Staters uh we + + align:start position:0% +because we have slotted Staters uh we + + + align:start position:0% +because we have slotted Staters uh we +decided to use a predefined Maxell one + + align:start position:0% +decided to use a predefined Maxell one + + + align:start position:0% +decided to use a predefined Maxell one +that matched roughly what we were + + align:start position:0% +that matched roughly what we were + + + align:start position:0% +that matched roughly what we were +looking for in terms of performance and + + align:start position:0% +looking for in terms of performance and + + + align:start position:0% +looking for in terms of performance and +those are the values given the right and + + align:start position:0% +those are the values given the right and + + + align:start position:0% +those are the values given the right and +that's the actual diagram of the stat so + + align:start position:0% +that's the actual diagram of the stat so + + + align:start position:0% +that's the actual diagram of the stat so +that was very convenient the motor + + align:start position:0% +that was very convenient the motor + + + align:start position:0% +that was very convenient the motor +geometry uh typically these are very + + align:start position:0% +geometry uh typically these are very + + + align:start position:0% +geometry uh typically these are very +important design variables uh the outer + + align:start position:0% +important design variables uh the outer + + + align:start position:0% +important design variables uh the outer +we chose based on some measurements we + + align:start position:0% +we chose based on some measurements we + + + align:start position:0% +we chose based on some measurements we +did down at The Hanger uh so then we + + align:start position:0% +did down at The Hanger uh so then we + + + align:start position:0% +did down at The Hanger uh so then we +ended up optimizing what was the ratio + + align:start position:0% +ended up optimizing what was the ratio + + + align:start position:0% +ended up optimizing what was the ratio +between these uh based on different + + align:start position:0% +between these uh based on different + + + align:start position:0% +between these uh based on different +values uh we decided on 252 as the inner + + align:start position:0% +values uh we decided on 252 as the inner + + + align:start position:0% +values uh we decided on 252 as the inner +diameter of the not like the engine + + align:start position:0% +diameter of the not like the engine + + + align:start position:0% +diameter of the not like the engine +where the axle is but the inner diameter + + align:start position:0% +where the axle is but the inner diameter + + + align:start position:0% +where the axle is but the inner diameter +of the rotor and + + align:start position:0% +of the rotor and + + + align:start position:0% +of the rotor and +uh + + align:start position:0% + + + + align:start position:0% + +so these okay those are all the other + + align:start position:0% +so these okay those are all the other + + + align:start position:0% +so these okay those are all the other +dimensions so we got an overall + + align:start position:0% +dimensions so we got an overall + + + align:start position:0% +dimensions so we got an overall +thickness of 86 mm + + align:start position:0% +thickness of 86 mm + + + align:start position:0% +thickness of 86 mm +uh performance analysis this is one of + + align:start position:0% +uh performance analysis this is one of + + + align:start position:0% +uh performance analysis this is one of +the images of our motor spinning on maxo + + align:start position:0% +the images of our motor spinning on maxo + + + align:start position:0% +the images of our motor spinning on maxo +which took us a while to figure out how + + align:start position:0% +which took us a while to figure out how + + + align:start position:0% +which took us a while to figure out how +to do that but finally got it to work + + align:start position:0% +to do that but finally got it to work + + + align:start position:0% +to do that but finally got it to work +kept crashing install the wrong + + align:start position:0% +kept crashing install the wrong + + + align:start position:0% +kept crashing install the wrong +operating system and then we just use + + align:start position:0% +operating system and then we just use + + + align:start position:0% +operating system and then we just use +graphs based on each one and pick the + + align:start position:0% +graphs based on each one and pick the + + + align:start position:0% +graphs based on each one and pick the +highest values um with each one as we as + + align:start position:0% +highest values um with each one as we as + + + align:start position:0% +highest values um with each one as we as +we went along can you just U just spend + + align:start position:0% +we went along can you just U just spend + + + align:start position:0% +we went along can you just U just spend +u a little bit of time explaining those + + align:start position:0% +u a little bit of time explaining those + + + align:start position:0% +u a little bit of time explaining those +graphs okay yeah uh so on this graph I + + align:start position:0% +graphs okay yeah uh so on this graph I + + + align:start position:0% +graphs okay yeah uh so on this graph I +think this is the torque graph um as one + + align:start position:0% +think this is the torque graph um as one + + + align:start position:0% +think this is the torque graph um as one +thing to notice is that on both graphs + + align:start position:0% +thing to notice is that on both graphs + + + align:start position:0% +thing to notice is that on both graphs +the time is 600 that's milliseconds so 6 + + align:start position:0% +the time is 600 that's milliseconds so 6 + + + align:start position:0% +the time is 600 that's milliseconds so 6 +seconds is the maximum we can simulate + + align:start position:0% +seconds is the maximum we can simulate + + + align:start position:0% +seconds is the maximum we can simulate +before I ran out of memory uh + + align:start position:0% +before I ran out of memory uh + + + align:start position:0% +before I ran out of memory uh +unfortunately here this part goes back + + align:start position:0% +unfortunately here this part goes back + + + align:start position:0% +unfortunately here this part goes back +to the design of the controller we + + align:start position:0% +to the design of the controller we + + + align:start position:0% +to the design of the controller we +didn't have our team wasn't mandated to + + align:start position:0% +didn't have our team wasn't mandated to + + + align:start position:0% +didn't have our team wasn't mandated to +design the controller that's why our + + align:start position:0% +design the controller that's why our + + + align:start position:0% +design the controller that's why our +torque only went up to think about this + + align:start position:0% +torque only went up to think about this + + + align:start position:0% +torque only went up to think about this +is the8 uh 8 uh newon M and it kind of + + align:start position:0% +is the8 uh 8 uh newon M and it kind of + + + align:start position:0% +is the8 uh 8 uh newon M and it kind of +it levels off because we don't have a + + align:start position:0% +it levels off because we don't have a + + + align:start position:0% +it levels off because we don't have a +proper controller and here the speed is + + align:start position:0% +proper controller and here the speed is + + + align:start position:0% +proper controller and here the speed is +just beginning to accelerate so I mean + + align:start position:0% +just beginning to accelerate so I mean + + + align:start position:0% +just beginning to accelerate so I mean +we only have 6 seconds so we can't + + align:start position:0% +we only have 6 seconds so we can't + + + align:start position:0% +we only have 6 seconds so we can't +really say anything + + align:start position:0% + + + + align:start position:0% + +more um okay so as far as actually + + align:start position:0% +more um okay so as far as actually + + + align:start position:0% +more um okay so as far as actually +manufacturing it we didn't actually + + align:start position:0% +manufacturing it we didn't actually + + + align:start position:0% +manufacturing it we didn't actually +manufacture it um mostly because it's + + align:start position:0% +manufacture it um mostly because it's + + + align:start position:0% +manufacture it um mostly because it's +rather expensive and a lot of the stuff + + align:start position:0% +rather expensive and a lot of the stuff + + + align:start position:0% +rather expensive and a lot of the stuff +such as mounting magnets and winding + + align:start position:0% +such as mounting magnets and winding + + + align:start position:0% +such as mounting magnets and winding +coils we emailed some people about coil + + align:start position:0% +coils we emailed some people about coil + + + align:start position:0% +coils we emailed some people about coil +winding they didn't really get back to + + align:start position:0% +winding they didn't really get back to + + + align:start position:0% +winding they didn't really get back to +us one person that said there's very + + align:start position:0% +us one person that said there's very + + + align:start position:0% +us one person that said there's very +little chance we'd be able to actually + + align:start position:0% +little chance we'd be able to actually + + + align:start position:0% +little chance we'd be able to actually +wind something on the road but like of + + align:start position:0% +wind something on the road but like of + + + align:start position:0% +wind something on the road but like of +our own project like this um it's also + + align:start position:0% +our own project like this um it's also + + + align:start position:0% +our own project like this um it's also +pretty expensive to buy all this stuff + + align:start position:0% +pretty expensive to buy all this stuff + + + align:start position:0% +pretty expensive to buy all this stuff +which we go over in a minute but you can + + align:start position:0% +which we go over in a minute but you can + + + align:start position:0% +which we go over in a minute but you can +see see here material choices pretty + + align:start position:0% +see see here material choices pretty + + + align:start position:0% +see see here material choices pretty +simple uh copper for electrical + + align:start position:0% +simple uh copper for electrical + + + align:start position:0% +simple uh copper for electrical +components uh steel for structure poly + + align:start position:0% +components uh steel for structure poly + + + align:start position:0% +components uh steel for structure poly +carb for sort of the safety shell and + + align:start position:0% +carb for sort of the safety shell and + + + align:start position:0% +carb for sort of the safety shell and +doubles as a structure for the St coils + + align:start position:0% +doubles as a structure for the St coils + + + align:start position:0% +doubles as a structure for the St coils +on and uh we use we just bought or would + + align:start position:0% +on and uh we use we just bought or would + + + align:start position:0% +on and uh we use we just bought or would +have + + align:start position:0% + + + + align:start position:0% + +bought um as far as the simply goes uh + + align:start position:0% +bought um as far as the simply goes uh + + + align:start position:0% +bought um as far as the simply goes uh +we're trying to get a simple design + + align:start position:0% +we're trying to get a simple design + + + align:start position:0% +we're trying to get a simple design +keep it light because it's an electric + + align:start position:0% +keep it light because it's an electric + + + align:start position:0% +keep it light because it's an electric +car um so we basically just have the + + align:start position:0% +car um so we basically just have the + + + align:start position:0% +car um so we basically just have the +rotor disc with the permanent magnets + + align:start position:0% +rotor disc with the permanent magnets + + + align:start position:0% +rotor disc with the permanent magnets +attached to the axle uh the Stater the + + align:start position:0% +attached to the axle uh the Stater the + + + align:start position:0% +attached to the axle uh the Stater the +Stater coils running two rings around + + align:start position:0% +Stater coils running two rings around + + + align:start position:0% +Stater coils running two rings around +the polycarbon safety shell those two + + align:start position:0% +the polycarbon safety shell those two + + + align:start position:0% +the polycarbon safety shell those two +ABS clamp together around the rotor and + + align:start position:0% +ABS clamp together around the rotor and + + + align:start position:0% +ABS clamp together around the rotor and +hold the axle in place and then there's + + align:start position:0% +hold the axle in place and then there's + + + align:start position:0% +hold the axle in place and then there's +sort of Steel arm to go around the + + align:start position:0% +sort of Steel arm to go around the + + + align:start position:0% +sort of Steel arm to go around the +outside and thing together we didn't + + align:start position:0% +outside and thing together we didn't + + + align:start position:0% +outside and thing together we didn't +want to use too much Shel because of + + align:start position:0% +want to use too much Shel because of + + + align:start position:0% +want to use too much Shel because of +magnetic effects you want to use it + + align:start position:0% +magnetic effects you want to use it + + + align:start position:0% +magnetic effects you want to use it +where you need it for structure and get + + align:start position:0% +where you need it for structure and get + + + align:start position:0% +where you need it for structure and get +rid of it everyone else uh so you can't + + align:start position:0% +rid of it everyone else uh so you can't + + + align:start position:0% +rid of it everyone else uh so you can't +read this really all but it's it's + + align:start position:0% +read this really all but it's it's + + + align:start position:0% +read this really all but it's it's +pretty expensive if you count like one + + align:start position:0% +pretty expensive if you count like one + + + align:start position:0% +pretty expensive if you count like one +time design cost and uh paid labor it + + align:start position:0% +time design cost and uh paid labor it + + + align:start position:0% +time design cost and uh paid labor it +comes out to 9300 bucks um which is more + + align:start position:0% +comes out to 9300 bucks um which is more + + + align:start position:0% +comes out to 9300 bucks um which is more +than the NGM one but it also uh we're + + align:start position:0% +than the NGM one but it also uh we're + + + align:start position:0% +than the NGM one but it also uh we're +going eventually for mess production and + + align:start position:0% +going eventually for mess production and + + + align:start position:0% +going eventually for mess production and +uh you know this includes design work + + align:start position:0% +uh you know this includes design work + + + align:start position:0% +uh you know this includes design work +and I just took these from the example + + align:start position:0% +and I just took these from the example + + + align:start position:0% +and I just took these from the example +sheet for like 75 bucks an hour and we + + align:start position:0% +sheet for like 75 bucks an hour and we + + + align:start position:0% +sheet for like 75 bucks an hour and we +spent a lot of time on it so you know uh + + align:start position:0% +spent a lot of time on it so you know uh + + + align:start position:0% +spent a lot of time on it so you know uh +without that and if you were to look at + + align:start position:0% +without that and if you were to look at + + + align:start position:0% +without that and if you were to look at +the economies of scale all a whole lot + + align:start position:0% +the economies of scale all a whole lot + + + align:start position:0% +the economies of scale all a whole lot +of these I think it be far cheaper + + align:start position:0% +of these I think it be far cheaper + + + align:start position:0% +of these I think it be far cheaper +than as + + align:start position:0% +than as + + + align:start position:0% +than as +as finally for uh for future work uh we + + align:start position:0% +as finally for uh for future work uh we + + + align:start position:0% +as finally for uh for future work uh we +definitely need to continue analyze this + + align:start position:0% +definitely need to continue analyze this + + + align:start position:0% +definitely need to continue analyze this +motor uh we need to do better more + + align:start position:0% +motor uh we need to do better more + + + align:start position:0% +motor uh we need to do better more +extensive more than6 uh seconds of + + align:start position:0% +extensive more than6 uh seconds of + + + align:start position:0% +extensive more than6 uh seconds of +analysis on the FDA or else we can't + + align:start position:0% +analysis on the FDA or else we can't + + + align:start position:0% +analysis on the FDA or else we can't +know how the motor will respond at a + + align:start position:0% +know how the motor will respond at a + + + align:start position:0% +know how the motor will respond at a +full speed or at any speed I me 6 + + align:start position:0% +full speed or at any speed I me 6 + + + align:start position:0% +full speed or at any speed I me 6 +seconds just for a startup that's not + + align:start position:0% +seconds just for a startup that's not + + + align:start position:0% +seconds just for a startup that's not +enough um and then another big point is + + align:start position:0% +enough um and then another big point is + + + align:start position:0% +enough um and then another big point is +motor controller uh the our original + + align:start position:0% +motor controller uh the our original + + + align:start position:0% +motor controller uh the our original +requirement to use the EVC 200 that's + + align:start position:0% +requirement to use the EVC 200 that's + + + align:start position:0% +requirement to use the EVC 200 that's +the NGM one that was not that's not + + align:start position:0% +the NGM one that was not that's not + + + align:start position:0% +the NGM one that was not that's not +sufficient we need to design our own and + + align:start position:0% +sufficient we need to design our own and + + + align:start position:0% +sufficient we need to design our own and +that is a completely new project finally + + align:start position:0% +that is a completely new project finally + + + align:start position:0% +that is a completely new project finally +uh we we're looking for continuing + + align:start position:0% +uh we we're looking for continuing + + + align:start position:0% +uh we we're looking for continuing +reduction cost um although there are + + align:start position:0% +reduction cost um although there are + + + align:start position:0% +reduction cost um although there are +economies of scale I'm sure there are + + align:start position:0% +economies of scale I'm sure there are + + + align:start position:0% +economies of scale I'm sure there are +other suppliers and manufacturers that + + align:start position:0% +other suppliers and manufacturers that + + + align:start position:0% +other suppliers and manufacturers that +we look + + align:start position:0% +we look + + + align:start position:0% +we look +toward finally Lessons Learned uh get + + align:start position:0% +toward finally Lessons Learned uh get + + + align:start position:0% +toward finally Lessons Learned uh get +expert advice from the start we're smart + + align:start position:0% +expert advice from the start we're smart + + + align:start position:0% +expert advice from the start we're smart +MIT students but even us looking through + + align:start position:0% +MIT students but even us looking through + + + align:start position:0% +MIT students but even us looking through +the internet looking through books we + + align:start position:0% +the internet looking through books we + + + align:start position:0% +the internet looking through books we +should have known to ask experts from + + align:start position:0% +should have known to ask experts from + + + align:start position:0% +should have known to ask experts from +the start to obtain the rules of thumb + + align:start position:0% +the start to obtain the rules of thumb + + + align:start position:0% +the start to obtain the rules of thumb +to guide us um get proper simulation + + align:start position:0% +to guide us um get proper simulation + + + align:start position:0% +to guide us um get proper simulation +software Maxwell 3D we did not find that + + align:start position:0% +software Maxwell 3D we did not find that + + + align:start position:0% +software Maxwell 3D we did not find that +until the second at least the second + + align:start position:0% +until the second at least the second + + + align:start position:0% +until the second at least the second +week and even then we had many many + + align:start position:0% +week and even then we had many many + + + align:start position:0% +week and even then we had many many +problems um constrain we we constrained + + align:start position:0% +problems um constrain we we constrained + + + align:start position:0% +problems um constrain we we constrained +our variables but we had to constrain + + align:start position:0% +our variables but we had to constrain + + + align:start position:0% +our variables but we had to constrain +even further for this class um and + + align:start position:0% +even further for this class um and + + + align:start position:0% +even further for this class um and +finally we simply needed some more time + + align:start position:0% +finally we simply needed some more time + + + align:start position:0% +finally we simply needed some more time +to further flush out our design and make + + align:start position:0% +to further flush out our design and make + + + align:start position:0% +to further flush out our design and make +it + + align:start position:0% +it + + + align:start position:0% +it +viable thank + + align:start position:0% + + + + align:start position:0% + +you questions + + align:start position:0% + + + + align:start position:0% + +anybody I I had a quick one I mean you + + align:start position:0% +anybody I I had a quick one I mean you + + + align:start position:0% +anybody I I had a quick one I mean you +guys this was kind of an impossible + + align:start position:0% +guys this was kind of an impossible + + + align:start position:0% +guys this was kind of an impossible +project for for a 4-we i class and I I + + align:start position:0% +project for for a 4-we i class and I I + + + align:start position:0% +project for for a 4-we i class and I I +think I think you've admire your courage + + align:start position:0% +think I think you've admire your courage + + + align:start position:0% +think I think you've admire your courage +and how far you pushed it I'm pleased + + align:start position:0% +and how far you pushed it I'm pleased + + + align:start position:0% +and how far you pushed it I'm pleased +with that the one question I have + + align:start position:0% +with that the one question I have + + + align:start position:0% +with that the one question I have +kind of surpr interesting that your cost + + align:start position:0% +kind of surpr interesting that your cost + + + align:start position:0% +kind of surpr interesting that your cost +estimate comes out almost the same as + + align:start position:0% +estimate comes out almost the same as + + + align:start position:0% +estimate comes out almost the same as +the NM motor uh the question I had was + + align:start position:0% +the NM motor uh the question I had was + + + align:start position:0% +the NM motor uh the question I had was +the NGM motor motor is a radial flux + + align:start position:0% +the NGM motor motor is a radial flux + + + align:start position:0% +the NGM motor motor is a radial flux +motor so so you said that you have to + + align:start position:0% +motor so so you said that you have to + + + align:start position:0% +motor so so you said that you have to +put these constraints in pretty quickly + + align:start position:0% +put these constraints in pretty quickly + + + align:start position:0% +put these constraints in pretty quickly +so that you could you know start getting + + align:start position:0% +so that you could you know start getting + + + align:start position:0% +so that you could you know start getting +a design uh but but it seems to me that + + align:start position:0% +a design uh but but it seems to me that + + + align:start position:0% +a design uh but but it seems to me that +the there's two things um that would + + align:start position:0% +the there's two things um that would + + + align:start position:0% +the there's two things um that would +have to be + + align:start position:0% +have to be + + + align:start position:0% +have to be +before you sort of go and fles this out + + align:start position:0% +before you sort of go and fles this out + + + align:start position:0% +before you sort of go and fles this out +in more detail one of them is the + + align:start position:0% +in more detail one of them is the + + + align:start position:0% +in more detail one of them is the +question of is actually a hub motor the + + align:start position:0% +question of is actually a hub motor the + + + align:start position:0% +question of is actually a hub motor the +right way to go for this vehicle or + + align:start position:0% +right way to go for this vehicle or + + + align:start position:0% +right way to go for this vehicle or +couldn't you have a motor sitting in the + + align:start position:0% +couldn't you have a motor sitting in the + + + align:start position:0% +couldn't you have a motor sitting in the +back of a seat with a little drive you + + align:start position:0% +back of a seat with a little drive you + + + align:start position:0% +back of a seat with a little drive you +know a simplified + + align:start position:0% +know a simplified + + + align:start position:0% +know a simplified +drive so that's that's one I just wanted + + align:start position:0% +drive so that's that's one I just wanted + + + align:start position:0% +drive so that's that's one I just wanted +you to respond to that and the second + + align:start position:0% +you to respond to that and the second + + + align:start position:0% +you to respond to that and the second +one was even if you did go with a hub + + align:start position:0% +one was even if you did go with a hub + + + align:start position:0% +one was even if you did go with a hub +motor uh if you allowed for a wider + + align:start position:0% +motor uh if you allowed for a wider + + + align:start position:0% +motor uh if you allowed for a wider +wheel you know the wheel the wheel trade + + align:start position:0% +wheel you know the wheel the wheel trade + + + align:start position:0% +wheel you know the wheel the wheel trade +off I mean um narrow Wheels give you + + align:start position:0% +off I mean um narrow Wheels give you + + + align:start position:0% +off I mean um narrow Wheels give you +good uh low rolling resistance and good + + align:start position:0% +good uh low rolling resistance and good + + + align:start position:0% +good uh low rolling resistance and good +efficiency of the vehicle uh but if you + + align:start position:0% +efficiency of the vehicle uh but if you + + + align:start position:0% +efficiency of the vehicle uh but if you +say well instead of the 86 mm how about + + align:start position:0% +say well instead of the 86 mm how about + + + align:start position:0% +say well instead of the 86 mm how about +120 mm wheel uh would that make the + + align:start position:0% +120 mm wheel uh would that make the + + + align:start position:0% +120 mm wheel uh would that make the +motor design much easier to + + align:start position:0% +motor design much easier to + + + align:start position:0% +motor design much easier to +do so the first one is on up motor yes + + align:start position:0% +do so the first one is on up motor yes + + + align:start position:0% +do so the first one is on up motor yes +or no and the second one is on wheel for + + align:start position:0% +or no and the second one is on wheel for + + + align:start position:0% +or no and the second one is on wheel for +the 1.0 see it's kind of strange cuz our + + align:start position:0% +the 1.0 see it's kind of strange cuz our + + + align:start position:0% +the 1.0 see it's kind of strange cuz our +our our we start out we have the same + + align:start position:0% +our our we start out we have the same + + + align:start position:0% +our our we start out we have the same +we're posted on motor for the 1.0 but + + align:start position:0% +we're posted on motor for the 1.0 but + + + align:start position:0% +we're posted on motor for the 1.0 but +it's supposed to be a stepping stone the + + align:start position:0% +it's supposed to be a stepping stone the + + + align:start position:0% +it's supposed to be a stepping stone the +2.0 the problem is a 1.0 and a 2.0 are + + align:start position:0% +2.0 the problem is a 1.0 and a 2.0 are + + + align:start position:0% +2.0 the problem is a 1.0 and a 2.0 are +completely different machines you know a + + align:start position:0% +completely different machines you know a + + + align:start position:0% +completely different machines you know a +1.0 machine is thr one press into a + + align:start position:0% +1.0 machine is thr one press into a + + + align:start position:0% +1.0 machine is thr one press into a +three wheel car where the Hub meter I + + align:start position:0% +three wheel car where the Hub meter I + + + align:start position:0% +three wheel car where the Hub meter I +don't know maybe it was more viable + + align:start position:0% +don't know maybe it was more viable + + + align:start position:0% +don't know maybe it was more viable +because of the spatial Dimensions but + + align:start position:0% +because of the spatial Dimensions but + + + align:start position:0% +because of the spatial Dimensions but +from the 2.0 that they're talking about + + align:start position:0% +from the 2.0 that they're talking about + + + align:start position:0% +from the 2.0 that they're talking about +a five person car with four wheels so + + align:start position:0% +a five person car with four wheels so + + + align:start position:0% +a five person car with four wheels so +then in that case for sure you might + + align:start position:0% +then in that case for sure you might + + + align:start position:0% +then in that case for sure you might +want to shy away from using the H motor + + align:start position:0% +want to shy away from using the H motor + + + align:start position:0% +want to shy away from using the H motor +because you get lost + + align:start position:0% +because you get lost + + + align:start position:0% +because you get lost +draw uh actually that's exactly say + + align:start position:0% +draw uh actually that's exactly say + + + align:start position:0% +draw uh actually that's exactly say +we're sort of done a weird match between + + align:start position:0% +we're sort of done a weird match between + + + align:start position:0% +we're sort of done a weird match between +like they want it to be able to fit in + + align:start position:0% +like they want it to be able to fit in + + + align:start position:0% +like they want it to be able to fit in +the one but a lot of design requirements + + align:start position:0% +the one but a lot of design requirements + + + align:start position:0% +the one but a lot of design requirements +are coming from the 2.0 what the 2.0 + + align:start position:0% +are coming from the 2.0 what the 2.0 + + + align:start position:0% +are coming from the 2.0 what the 2.0 +design looks like right now so it was + + align:start position:0% +design looks like right now so it was + + + align:start position:0% +design looks like right now so it was +sort of like well yes we're going to use + + align:start position:0% +sort of like well yes we're going to use + + + align:start position:0% +sort of like well yes we're going to use +Hubers that's fixed I don't know whether + + align:start position:0% +Hubers that's fixed I don't know whether + + + align:start position:0% +Hubers that's fixed I don't know whether +or not they're they'd be better off not + + align:start position:0% +or not they're they'd be better off not + + + align:start position:0% +or not they're they'd be better off not +doing hubs Central dve TR I think a lot + + align:start position:0% +doing hubs Central dve TR I think a lot + + + align:start position:0% +doing hubs Central dve TR I think a lot +of modern electric vehicles uh are are + + align:start position:0% +of modern electric vehicles uh are are + + + align:start position:0% +of modern electric vehicles uh are are +switching to H MERS like the Tesla + + align:start position:0% +switching to H MERS like the Tesla + + + align:start position:0% +switching to H MERS like the Tesla +rooster there's a there's a little BM or + + align:start position:0% +rooster there's a there's a little BM or + + + align:start position:0% +rooster there's a there's a little BM or +not a Mini Cooper like 640 horsepower + + align:start position:0% +not a Mini Cooper like 640 horsepower + + + align:start position:0% +not a Mini Cooper like 640 horsepower +just upad + + align:start position:0% +just upad + + + align:start position:0% +just upad +main advantage of a hub motor is that + + align:start position:0% +main advantage of a hub motor is that + + + align:start position:0% +main advantage of a hub motor is that +there's no losses to gear I mean you're + + align:start position:0% +there's no losses to gear I mean you're + + + align:start position:0% +there's no losses to gear I mean you're +the motor is direct the motor is + + align:start position:0% +the motor is direct the motor is + + + align:start position:0% +the motor is direct the motor is +directly on the wheel it's actuating the + + align:start position:0% +directly on the wheel it's actuating the + + + align:start position:0% +directly on the wheel it's actuating the +wheel itself so you don't have gears to + + align:start position:0% +wheel itself so you don't have gears to + + + align:start position:0% +wheel itself so you don't have gears to +transmit U through a + + align:start position:0% +transmit U through a + + + align:start position:0% +transmit U through a +little B of the shaft where you can have + + align:start position:0% +little B of the shaft where you can have + + + align:start position:0% +little B of the shaft where you can have +glosses in you can you can actually + + align:start position:0% +glosses in you can you can actually + + + align:start position:0% +glosses in you can you can actually +entirely you can move your control + + align:start position:0% +entirely you can move your control + + + align:start position:0% +entirely you can move your control +system from half like you know moving + + align:start position:0% +system from half like you know moving + + + align:start position:0% +system from half like you know moving +levers around and have digital to being + + align:start position:0% +levers around and have digital to being + + + align:start position:0% +levers around and have digital to being +entirely digital just driving just + + align:start position:0% +entirely digital just driving just + + + align:start position:0% +entirely digital just driving just +driving the motors + + align:start position:0% + + + + align:start position:0% + +we trying the VS1 wheel + + align:start position:0% + + + + align:start position:0% + +so okay thank you very much \ No newline at end of file diff --git a/LoIXB2GJHkg.txt b/LoIXB2GJHkg.txt new file mode 100644 index 0000000000000000000000000000000000000000..f357fa4acd076336401610989b5c2f992f1a648d --- /dev/null +++ b/LoIXB2GJHkg.txt @@ -0,0 +1,12872 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu good so let us + + align:start position:0% + + + + align:start position:0% + +start so so let me first quickly remind + + align:start position:0% +start so so let me first quickly remind + + + align:start position:0% +start so so let me first quickly remind +you what we did in the last + + align:start position:0% +you what we did in the last + + + align:start position:0% +you what we did in the last +lecture so we first talk about + + align:start position:0% +lecture so we first talk about + + + align:start position:0% +lecture so we first talk about +the say talk about General + + align:start position:0% +the say talk about General + + + align:start position:0% +the say talk about General +observables in Gage + + align:start position:0% + + + + align:start position:0% + +Series so we are interested + + align:start position:0% + + + + align:start position:0% + +in say correlation functions + + align:start position:0% + + + + align:start position:0% + +of gauging wiring + + align:start position:0% + + + + align:start position:0% + +operators in particular we will be uh uh + + align:start position:0% +operators in particular we will be uh uh + + + align:start position:0% +operators in particular we will be uh uh +focus on local + + align:start position:0% + + + + align:start position:0% + +operators + + align:start position:0% +operators + + + align:start position:0% +operators +Lo so we um say for + + align:start position:0% +Lo so we um say for + + + align:start position:0% +Lo so we um say for +example so the local operator can be + + align:start position:0% +example so the local operator can be + + + align:start position:0% +example so the local operator can be +also be separated into say the single + + align:start position:0% +also be separated into say the single + + + align:start position:0% +also be separated into say the single +Chace operator + + align:start position:0% + + + + align:start position:0% + +uh or the yeah single Choice operator so + + align:start position:0% +uh or the yeah single Choice operator so + + + align:start position:0% +uh or the yeah single Choice operator so +n just label different operators or say + + align:start position:0% +n just label different operators or say + + + align:start position:0% +n just label different operators or say +the the double Trace operator sometimes + + align:start position:0% +the the double Trace operator sometimes + + + align:start position:0% +the the double Trace operator sometimes +in order to avoid + + align:start position:0% +in order to avoid + + + align:start position:0% +in order to avoid +confusion we put some dots that means + + align:start position:0% +confusion we put some dots that means + + + align:start position:0% +confusion we put some dots that means +these two operator should be considered + + align:start position:0% +these two operator should be considered + + + align:start position:0% +these two operator should be considered +group together and then you Val then + + align:start position:0% +group together and then you Val then + + + align:start position:0% +group together and then you Val then +evaluate some SpaceTime Point say this + + align:start position:0% +evaluate some SpaceTime Point say this + + + align:start position:0% +evaluate some SpaceTime Point say this +would be a double Choice operator + + align:start position:0% + + + + align:start position:0% + +and uh or maybe the higher ones + + align:start position:0% + + + + align:start position:0% + +okay and uh also we + + align:start position:0% + + + + align:start position:0% + +found that typical correlation function + + align:start position:0% +found that typical correlation function + + + align:start position:0% +found that typical correlation function +say if I look at endpoint + + align:start position:0% +say if I look at endpoint + + + align:start position:0% +say if I look at endpoint +function endpoint connective green + + align:start position:0% +function endpoint connective green + + + align:start position:0% +function endpoint connective green +function of single Chace + + align:start position:0% +function of single Chace + + + align:start position:0% +function of single Chace +operators then + + align:start position:0% +operators then + + + align:start position:0% +operators then +the scale with n as the + + align:start position:0% +the scale with n as the + + + align:start position:0% +the scale with n as the +following again you sum over order H + + align:start position:0% +following again you sum over order H + + + align:start position:0% +following again you sum over order H +which is a topology of your + + align:start position:0% +which is a topology of your + + + align:start position:0% +which is a topology of your +diagrams and then to the power n to the + + align:start position:0% +diagrams and then to the power n to the + + + align:start position:0% +diagrams and then to the power n to the +minus n n is the number of the the + + align:start position:0% +minus n n is the number of the the + + + align:start position:0% +minus n n is the number of the the +endpoint functions the minus 2 H then + + align:start position:0% +endpoint functions the minus 2 H then + + + align:start position:0% +endpoint functions the minus 2 H then +say + + align:start position:0% +say + + + align:start position:0% +say +some some function FN which can depend + + align:start position:0% +some some function FN which can depend + + + align:start position:0% +some some function FN which can depend +on the coing constant and also will + + align:start position:0% +on the coing constant and also will + + + align:start position:0% +on the coing constant and also will +depend on X1 X2 xn Etc okay so so this + + align:start position:0% +depend on X1 X2 xn Etc okay so so this + + + align:start position:0% +depend on X1 X2 xn Etc okay so so this +will start as leading + + align:start position:0% +will start as leading + + + align:start position:0% +will start as leading +order which n 2us n which come from the + + align:start position:0% +order which n 2us n which come from the + + + align:start position:0% +order which n 2us n which come from the +planer + + align:start position:0% + + + + align:start position:0% + +diagram and then the next order just n + + align:start position:0% +diagram and then the next order just n + + + align:start position:0% +diagram and then the next order just n +to the minus n so this will be the + + align:start position:0% +to the minus n so this will be the + + + align:start position:0% +to the minus n so this will be the +Taurus + + align:start position:0% +Taurus + + + align:start position:0% +Taurus +diagram the diagram you can put on the + + align:start position:0% + + + + align:start position:0% + +Taurus or genus two diagrams + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +ex so we also discuss + + align:start position:0% +ex so we also discuss + + + align:start position:0% +ex so we also discuss +that this Behavior has important + + align:start position:0% +that this Behavior has important + + + align:start position:0% +that this Behavior has important +physical + + align:start position:0% +physical + + + align:start position:0% +physical +implications we talked about two + + align:start position:0% + + + + align:start position:0% + +implications we talk about two + + align:start position:0% +implications we talk about two + + + align:start position:0% +implications we talk about two +implications + + align:start position:0% + + + + align:start position:0% + +you say that kind of + + align:start position:0% +you say that kind of + + + align:start position:0% +you say that kind of +Independence means that in the L + + align:start position:0% + + + + align:start position:0% + +limit say in the angle to Infinity + + align:start position:0% +limit say in the angle to Infinity + + + align:start position:0% +limit say in the angle to Infinity +limit we can essentially + + align:start position:0% +limit we can essentially + + + align:start position:0% +limit we can essentially +treat the action of the single particle + + align:start position:0% +treat the action of the single particle + + + align:start position:0% +treat the action of the single particle +a single Choice operator say on the + + align:start position:0% +a single Choice operator say on the + + + align:start position:0% +a single Choice operator say on the +vacuum as a sing as generating a single + + align:start position:0% +vacuum as a sing as generating a single + + + align:start position:0% +vacuum as a sing as generating a single +particle state + + align:start position:0% + + + + align:start position:0% + +say uh we often call this as Global + + align:start position:0% +say uh we often call this as Global + + + align:start position:0% +say uh we often call this as Global +State glose + + align:start position:0% + + + + align:start position:0% + +okay so this single particle + + align:start position:0% +okay so this single particle + + + align:start position:0% +okay so this single particle +State they don't have to appear really + + align:start position:0% +State they don't have to appear really + + + align:start position:0% +State they don't have to appear really +as say asymptotic + + align:start position:0% +as say asymptotic + + + align:start position:0% +as say asymptotic +States uh in your scattering ex I just + + align:start position:0% +States uh in your scattering ex I just + + + align:start position:0% +States uh in your scattering ex I just +say the behavior of such States behave + + align:start position:0% +say the behavior of such States behave + + + align:start position:0% +say the behavior of such States behave +like single particles and then if you + + align:start position:0% +like single particles and then if you + + + align:start position:0% +like single particles and then if you +act on the double Chace + + align:start position:0% + + + + align:start position:0% + +operator on the + + align:start position:0% +operator on the + + + align:start position:0% +operator on the +Zero then that give you the the two + + align:start position:0% +Zero then that give you the the two + + + align:start position:0% +Zero then that give you the the two +particle + + align:start position:0% + + + + align:start position:0% + +States and ex and the three and the + + align:start position:0% +States and ex and the three and the + + + align:start position:0% +States and ex and the three and the +triple chice or give you the three + + align:start position:0% +triple chice or give you the three + + + align:start position:0% +triple chice or give you the three +particle State + + align:start position:0% +particle State + + + align:start position:0% +particle State +ex + + align:start position:0% +ex + + + align:start position:0% +ex +okay so so this is one + + align:start position:0% +okay so so this is one + + + align:start position:0% +okay so so this is one +aspect and the and the second aspect + + align:start position:0% +aspect and the and the second aspect + + + align:start position:0% +aspect and the and the second aspect +is that + + align:start position:0% + + + + align:start position:0% + +if say if there's some single Choice + + align:start position:0% +if say if there's some single Choice + + + align:start position:0% +if say if there's some single Choice +operator whose expectation value is non + + align:start position:0% +operator whose expectation value is non + + + align:start position:0% +operator whose expectation value is non +zero then the + + align:start position:0% + + + + align:start position:0% + +fluctuation are + + align:start position:0% + + + + align:start position:0% + +suppressed okay so for example if you + + align:start position:0% +suppressed okay so for example if you + + + align:start position:0% +suppressed okay so for example if you +look + + align:start position:0% +look + + + align:start position:0% +look +at the + + align:start position:0% + + + + align:start position:0% + +ratio if you look at the ratio of the + + align:start position:0% + + + + align:start position:0% + +variance so o Square the connected part + + align:start position:0% +variance so o Square the connected part + + + align:start position:0% +variance so o Square the connected part +of the O square is essentially the + + align:start position:0% +of the O square is essentially the + + + align:start position:0% +of the O square is essentially the +variance of the of this guy and divided + + align:start position:0% +variance of the of this guy and divided + + + align:start position:0% +variance of the of this guy and divided +by expectation value itself then scale + + align:start position:0% +by expectation value itself then scale + + + align:start position:0% +by expectation value itself then scale +is one one/ M because of that behavior + + align:start position:0% +is one one/ M because of that behavior + + + align:start position:0% +is one one/ M because of that behavior +and this goes zero okay in the Lin as n + + align:start position:0% +and this goes zero okay in the Lin as n + + + align:start position:0% +and this goes zero okay in the Lin as n +goes + + align:start position:0% +goes + + + align:start position:0% +goes +Infinity so that means the fluctuations + + align:start position:0% +Infinity so that means the fluctuations + + + align:start position:0% +Infinity so that means the fluctuations +are suppressed + + align:start position:0% + + + + align:start position:0% + +so any questions regarding + + align:start position:0% + + + + align:start position:0% + +this good okay so now let's talk about + + align:start position:0% +this good okay so now let's talk about + + + align:start position:0% +this good okay so now let's talk about +the third aspect of it the third + + align:start position:0% + + + + align:start position:0% + +implication so now suppose we interpret + + align:start position:0% + + + + align:start position:0% + +suppose we + + align:start position:0% + + + + align:start position:0% + +interpret this endpoint + + align:start position:0% + + + + align:start position:0% + +function so disconnected import + + align:start position:0% + + + + align:start position:0% + +function say uh we which I can + + align:start position:0% +function say uh we which I can + + + align:start position:0% +function say uh we which I can +symbolically write as say some kind of + + align:start position:0% +symbolically write as say some kind of + + + align:start position:0% +symbolically write as say some kind of +blob then you have any external + + align:start position:0% + + + + align:start position:0% + +XS say one two + + align:start position:0% +XS say one two + + + align:start position:0% +XS say one two +3us one n + + align:start position:0% +3us one n + + + align:start position:0% +3us one n +okay so so each nine each N means the + + align:start position:0% +okay so so each nine each N means the + + + align:start position:0% +okay so so each nine each N means the +external operator + + align:start position:0% +external operator + + + align:start position:0% +external operator +insertions so if we interpret this as + + align:start position:0% +insertions so if we interpret this as + + + align:start position:0% +insertions so if we interpret this as +some kind of scattering + + align:start position:0% + + + + align:start position:0% + +amplitude as some kind of scattering + + align:start position:0% +amplitude as some kind of scattering + + + align:start position:0% +amplitude as some kind of scattering +amplitude + + align:start position:0% + + + + align:start position:0% + +so as generates some kind of scattering + + align:start position:0% +so as generates some kind of scattering + + + align:start position:0% +so as generates some kind of scattering +amplitude of the Ang + + align:start position:0% + + + + align:start position:0% + +glose of Ang + + align:start position:0% + + + + align:start position:0% + +globos then you can show because of this + + align:start position:0% +globos then you can show because of this + + + align:start position:0% +globos then you can show because of this +Behavior you can show because of this n + + align:start position:0% +Behavior you can show because of this n + + + align:start position:0% +Behavior you can show because of this n +scaling + + align:start position:0% +scaling + + + align:start position:0% +scaling +and + + align:start position:0% +and + + + align:start position:0% +and +then again to reading + + align:start position:0% + + + + align:start position:0% + +order in the angle to Infinity + + align:start position:0% + + + + align:start position:0% + +limit the + + align:start position:0% + + + + align:start position:0% + +scatterings are classical + + align:start position:0% + + + + align:start position:0% + +by classical + + align:start position:0% +by classical + + + align:start position:0% +by classical +means you said it only + + align:start position:0% + + + + align:start position:0% + +involves only involve two + + align:start position:0% + + + + align:start position:0% + +level Sky + + align:start position:0% + + + + align:start position:0% + +RS okay + + align:start position:0% + + + + align:start position:0% + +so now I'm going to show this uh uh this + + align:start position:0% +so now I'm going to show this uh uh this + + + align:start position:0% +so now I'm going to show this uh uh this +is the uh conclusion so I'm going to uh + + align:start position:0% +is the uh conclusion so I'm going to uh + + + align:start position:0% +is the uh conclusion so I'm going to uh +uh justify this + + align:start position:0% + + + + align:start position:0% + +statement so before I start justifying + + align:start position:0% +statement so before I start justifying + + + align:start position:0% +statement so before I start justifying +this statement do you have any + + align:start position:0% + + + + align:start position:0% + +questions good so so let me just make a + + align:start position:0% +questions good so so let me just make a + + + align:start position:0% +questions good so so let me just make a +few uh um + + align:start position:0% +few uh um + + + align:start position:0% +few uh um +remark so first so let's look at the + + align:start position:0% +remark so first so let's look at the + + + align:start position:0% +remark so first so let's look at the +simplest case which is the + + align:start position:0% +simplest case which is the + + + align:start position:0% +simplest case which is the +three point + + align:start position:0% + + + + align:start position:0% + +function so threo function can be + + align:start position:0% +function so threo function can be + + + align:start position:0% +function so threo function can be +considered just as effective vertex so + + align:start position:0% +considered just as effective vertex so + + + align:start position:0% +considered just as effective vertex so +it can be consider as effective vertex + + align:start position:0% +it can be consider as effective vertex + + + align:start position:0% +it can be consider as effective vertex +of three particle intact with each other + + align:start position:0% +of three particle intact with each other + + + align:start position:0% +of three particle intact with each other +say one say one Global split into two + + align:start position:0% +say one say one Global split into two + + + align:start position:0% +say one say one Global split into two +Global ex okay so this from that + + align:start position:0% +Global ex okay so this from that + + + align:start position:0% +Global ex okay so this from that +definition is scales as one/ + + align:start position:0% +definition is scales as one/ + + + align:start position:0% +definition is scales as one/ +n okay this scale is one/ + + align:start position:0% +n okay this scale is one/ + + + align:start position:0% +n okay this scale is one/ +n so if we treat it as a basic + + align:start position:0% +n so if we treat it as a basic + + + align:start position:0% +n so if we treat it as a basic +vertex so so if we treat it as a basic + + align:start position:0% + + + + align:start position:0% + +vertex so if we suppose we treat it + + align:start position:0% +vertex so if we suppose we treat it + + + align:start position:0% +vertex so if we suppose we treat it +suppose we + + align:start position:0% + + + + align:start position:0% + +treat we treat it as the basic + + align:start position:0% + + + + align:start position:0% + +vertex with cing G so G is one / + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% + + + + align:start position:0% + +okay then from + + align:start position:0% + + + + align:start position:0% + +simple then easy to see + + align:start position:0% + + + + align:start position:0% + +then then two level + + align:start position:0% + + + + align:start position:0% + +amplitudes for EMP particle + + align:start position:0% + + + + align:start position:0% + +scattering and particle + + align:start position:0% +scattering and particle + + + align:start position:0% +scattering and particle +scatterings are precisely scales as G to + + align:start position:0% +scatterings are precisely scales as G to + + + align:start position:0% +scatterings are precisely scales as G to +the nus 2 which is n to the power minus + + align:start position:0% +the nus 2 which is n to the power minus + + + align:start position:0% +the nus 2 which is n to the power minus +2us n and this is precisely we see uh + + align:start position:0% +2us n and this is precisely we see uh + + + align:start position:0% +2us n and this is precisely we see uh +for the leading scaling + + align:start position:0% +for the leading scaling + + + align:start position:0% +for the leading scaling +here + + align:start position:0% +here + + + align:start position:0% +here +okay so is this fact obvious to you that + + align:start position:0% +okay so is this fact obvious to you that + + + align:start position:0% +okay so is this fact obvious to you that +the tree level scattering for M + + align:start position:0% +the tree level scattering for M + + + align:start position:0% +the tree level scattering for M +particles with the with with basic + + align:start position:0% +particles with the with with basic + + + align:start position:0% +particles with the with with basic +vertex given by G with scale like + + align:start position:0% + + + + align:start position:0% + +this oh sorry why is a proportional to G + + align:start position:0% +this oh sorry why is a proportional to G + + + align:start position:0% +this oh sorry why is a proportional to G +because each uh each this in the double + + align:start position:0% +because each uh each this in the double + + + align:start position:0% +because each uh each this in the double +line notation each line contributes to + + align:start position:0% +line notation each line contributes to + + + align:start position:0% +line notation each line contributes to +like a g Square so uh how letter G comes + + align:start position:0% +like a g Square so uh how letter G comes + + + align:start position:0% +like a g Square so uh how letter G comes +from no which G you are talking about oh + + align:start position:0% +from no which G you are talking about oh + + + align:start position:0% +from no which G you are talking about oh +no no no no no oh uh uh maybe let me + + align:start position:0% +no no no no no oh uh uh maybe let me + + + align:start position:0% +no no no no no oh uh uh maybe let me +call it + + align:start position:0% +call it + + + align:start position:0% +call it +Lambda it's a different G is a different + + align:start position:0% +Lambda it's a different G is a different + + + align:start position:0% +Lambda it's a different G is a different +yeah let me call it um Kaa or let me + + align:start position:0% +yeah let me call it um Kaa or let me + + + align:start position:0% +yeah let me call it um Kaa or let me +call it + + align:start position:0% +call it + + + align:start position:0% +call it +the GT + + align:start position:0% + + + + align:start position:0% + +yeah it's not the same it's not the same + + align:start position:0% +yeah it's not the same it's not the same + + + align:start position:0% +yeah it's not the same it's not the same +G as before this is just something I I + + align:start position:0% +G as before this is just something I I + + + align:start position:0% +G as before this is just something I I +de lo I just call it some kind of + + align:start position:0% +de lo I just call it some kind of + + + align:start position:0% +de lo I just call it some kind of +effective + + align:start position:0% +effective + + + align:start position:0% +effective +company + + align:start position:0% +company + + + align:start position:0% +company +yeah yeah just imagine you have a + + align:start position:0% +yeah yeah just imagine you have a + + + align:start position:0% +yeah yeah just imagine you have a +process whose basic interacting vertex + + align:start position:0% +process whose basic interacting vertex + + + align:start position:0% +process whose basic interacting vertex +is G + + align:start position:0% +is G + + + align:start position:0% +is G +TAA and G is order one over + + align:start position:0% +TAA and G is order one over + + + align:start position:0% +TAA and G is order one over +n and then the then the tree level + + align:start position:0% +n and then the then the tree level + + + align:start position:0% +n and then the then the tree level +scattering for imp particle will depend + + align:start position:0% +scattering for imp particle will depend + + + align:start position:0% +scattering for imp particle will depend +on this component to be G to the m minus + + align:start position:0% +on this component to be G to the m minus + + + align:start position:0% +on this component to be G to the m minus +2 okay is this clear to you yeah I can + + align:start position:0% +2 okay is this clear to you yeah I can + + + align:start position:0% +2 okay is this clear to you yeah I can +just draw a tree diagram you can see it + + align:start position:0% +just draw a tree diagram you can see it + + + align:start position:0% +just draw a tree diagram you can see it +immediately + + align:start position:0% +immediately + + + align:start position:0% +immediately +okay so uh so this is + + align:start position:0% +okay so uh so this is + + + align:start position:0% +okay so uh so this is +consistent so this behavior is + + align:start position:0% +consistent so this behavior is + + + align:start position:0% +consistent so this behavior is +consistent to to interpret that as a + + align:start position:0% +consistent to to interpret that as a + + + align:start position:0% +consistent to to interpret that as a +tree but you don't actually have to + + align:start position:0% +tree but you don't actually have to + + + align:start position:0% +tree but you don't actually have to +assume the the basic the threep point + + align:start position:0% +assume the the basic the threep point + + + align:start position:0% +assume the the basic the threep point +vertex so you can also say + + align:start position:0% +vertex so you can also say + + + align:start position:0% +vertex so you can also say +you can also + + align:start position:0% + + + + align:start position:0% + +include so how all the + + align:start position:0% + + + + align:start position:0% + +vertices but your vertices which you + + align:start position:0% +vertices but your vertices which you + + + align:start position:0% +vertices but your vertices which you +include should be consistent with this + + align:start position:0% +include should be consistent with this + + + align:start position:0% +include should be consistent with this +scaling okay say suppose if you want to + + align:start position:0% +scaling okay say suppose if you want to + + + align:start position:0% +scaling okay say suppose if you want to +include a four particle vertices + + align:start position:0% + + + + align:start position:0% + +and then this should scales as G Thea + + align:start position:0% +and then this should scales as G Thea + + + align:start position:0% +and then this should scales as G Thea +Square which is n to the minus + + align:start position:0% +Square which is n to the minus + + + align:start position:0% +Square which is n to the minus +2 because the four point connective + + align:start position:0% +2 because the four point connective + + + align:start position:0% +2 because the four point connective +function should scale as a minus two and + + align:start position:0% +function should scale as a minus two and + + + align:start position:0% +function should scale as a minus two and +similarly if you have a five point + + align:start position:0% +similarly if you have a five point + + + align:start position:0% +similarly if you have a five point +vertex then you should scale s g Thea to + + align:start position:0% +vertex then you should scale s g Thea to + + + align:start position:0% +vertex then you should scale s g Thea to +the cube which is n to Theus 3 because + + align:start position:0% +the cube which is n to Theus 3 because + + + align:start position:0% +the cube which is n to Theus 3 because +the Five Point function should scale as + + align:start position:0% +the Five Point function should scale as + + + align:start position:0% +the Five Point function should scale as +m 3 okay so you can also add such higher + + align:start position:0% +m 3 okay so you can also add such higher + + + align:start position:0% +m 3 okay so you can also add such higher +all the vertices as far as you are + + align:start position:0% +all the vertices as far as you are + + + align:start position:0% +all the vertices as far as you are +consistent with this Nigerian + + align:start position:0% +consistent with this Nigerian + + + align:start position:0% +consistent with this Nigerian +scaling so you then you can easily + + align:start position:0% +scaling so you then you can easily + + + align:start position:0% +scaling so you then you can easily +convince + + align:start position:0% +convince + + + align:start position:0% +convince +yourself that even including such high + + align:start position:0% +yourself that even including such high + + + align:start position:0% +yourself that even including such high +order + + align:start position:0% +order + + + align:start position:0% +order +vertices uh that's do not change this + + align:start position:0% +vertices uh that's do not change this + + + align:start position:0% +vertices uh that's do not change this +conclusion does not change this + + align:start position:0% +conclusion does not change this + + + align:start position:0% +conclusion does not change this +conclusion that the any level + + align:start position:0% +conclusion that the any level + + + align:start position:0% +conclusion that the any level +amplitude again for for n particles with + + align:start position:0% +amplitude again for for n particles with + + + align:start position:0% +amplitude again for for n particles with +scales like this okay + + align:start position:0% +scales like this okay + + + align:start position:0% +scales like this okay +uh we not change that + + align:start position:0% + + + + align:start position:0% + +conclusion so this is second + + align:start position:0% +conclusion so this is second + + + align:start position:0% +conclusion so this is second +statement and this two statement just to + + align:start position:0% +statement and this two statement just to + + + align:start position:0% +statement and this two statement just to +give you a humanistic way to see that + + align:start position:0% +give you a humanistic way to see that + + + align:start position:0% +give you a humanistic way to see that +the that that this kind of scaling can + + align:start position:0% +the that that this kind of scaling can + + + align:start position:0% +the that that this kind of scaling can +be generated indeed generated by three + + align:start position:0% +be generated indeed generated by three + + + align:start position:0% +be generated indeed generated by three +level + + align:start position:0% +level + + + align:start position:0% +level +scatterings so now I'm going to + + align:start position:0% + + + + align:start position:0% + +prove so now I'm going to + + align:start position:0% +prove so now I'm going to + + + align:start position:0% +prove so now I'm going to +prove that in the lar limit to Le in + + align:start position:0% + + + + align:start position:0% + +order in + + align:start position:0% +order in + + + align:start position:0% +order in +n in any such kind of correlation + + align:start position:0% +n in any such kind of correlation + + + align:start position:0% +n in any such kind of correlation +functions + + align:start position:0% + + + + align:start position:0% + +there are no + + align:start position:0% + + + + align:start position:0% + +more than + + align:start position:0% +more than + + + align:start position:0% +more than +one there's no + + align:start position:0% +one there's no + + + align:start position:0% +one there's no +more there's there are only maybe let me + + align:start position:0% +more there's there are only maybe let me + + + align:start position:0% +more there's there are only maybe let me +just say it easier there are + + align:start position:0% + + + + align:start position:0% + +only one particle in the media States + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so I'm going to show + + align:start position:0% +okay so I'm going to show + + + align:start position:0% +okay so I'm going to show +this + + align:start position:0% + + + + align:start position:0% + +um so let's consider say a three part so + + align:start position:0% +um so let's consider say a three part so + + + align:start position:0% +um so let's consider say a three part so +by one particle I always mean one + + align:start position:0% +by one particle I always mean one + + + align:start position:0% +by one particle I always mean one +particle in this sense okay so one + + align:start position:0% +particle in this sense okay so one + + + align:start position:0% +particle in this sense okay so one +particle in this sense + + align:start position:0% + + + + align:start position:0% + +so I will do it a little bit + + align:start position:0% +so I will do it a little bit + + + align:start position:0% +so I will do it a little bit +theistically not very precise but I + + align:start position:0% +theistically not very precise but I + + + align:start position:0% +theistically not very precise but I +think it's it's it's rigorous but it's + + align:start position:0% +think it's it's it's rigorous but it's + + + align:start position:0% +think it's it's it's rigorous but it's +not but I will not write the precise uh + + align:start position:0% +not but I will not write the precise uh + + + align:start position:0% +not but I will not write the precise uh +um uh yeah we not write rigorous + + align:start position:0% +um uh yeah we not write rigorous + + + align:start position:0% +um uh yeah we not write rigorous +formulas so so let's consider just as + + align:start position:0% +formulas so so let's consider just as + + + align:start position:0% +formulas so so let's consider just as +example + + align:start position:0% +example + + + align:start position:0% +example +consider uh the threep point + + align:start position:0% +consider uh the threep point + + + align:start position:0% +consider uh the threep point +scattering threo functions say I have + + align:start position:0% +scattering threo functions say I have + + + align:start position:0% +scattering threo functions say I have +three operators uh uh I look at this + + align:start position:0% +three operators uh uh I look at this + + + align:start position:0% +three operators uh uh I look at this +connected uh uh uh uh a green function + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +now in those + + align:start position:0% +now in those + + + align:start position:0% +now in those +places we can in principle insert + + align:start position:0% +places we can in principle insert + + + align:start position:0% +places we can in principle insert +complete set of States okay uh and those + + align:start position:0% +complete set of States okay uh and those + + + align:start position:0% +complete set of States okay uh and those +can be considered as intermediate uh + + align:start position:0% +can be considered as intermediate uh + + + align:start position:0% +can be considered as intermediate uh +intermediate State contribute to this + + align:start position:0% +intermediate State contribute to this + + + align:start position:0% +intermediate State contribute to this +process say if I consider scattering + + align:start position:0% +process say if I consider scattering + + + align:start position:0% +process say if I consider scattering +process and then and then I can insert + + align:start position:0% +process and then and then I can insert + + + align:start position:0% +process and then and then I can insert +the a complete set of States here and + + align:start position:0% +the a complete set of States here and + + + align:start position:0% +the a complete set of States here and +those state which gives a non-trivial + + align:start position:0% +those state which gives a non-trivial + + + align:start position:0% +those state which gives a non-trivial +contribution can be considered as the a + + align:start position:0% +contribution can be considered as the a + + + align:start position:0% +contribution can be considered as the a +contribution from some intermediate + + align:start position:0% +contribution from some intermediate + + + align:start position:0% +contribution from some intermediate +States + + align:start position:0% +States + + + align:start position:0% +States +okay and uh + + align:start position:0% +okay and uh + + + align:start position:0% +okay and uh +so so for example let + + align:start position:0% +so so for example let + + + align:start position:0% +so so for example let +me introduce a single particle States + + align:start position:0% +me introduce a single particle States + + + align:start position:0% +me introduce a single particle States +here say say this o1 O2 + + align:start position:0% + + + + align:start position:0% + +O3 so suppose I insert a complete set of + + align:start position:0% +O3 so suppose I insert a complete set of + + + align:start position:0% +O3 so suppose I insert a complete set of +I insert the one + + align:start position:0% +I insert the one + + + align:start position:0% +I insert the one +here this one will cons include the sum + + align:start position:0% +here this one will cons include the sum + + + align:start position:0% +here this one will cons include the sum +of all + + align:start position:0% + + + + align:start position:0% + +possible single particle + + align:start position:0% + + + + align:start position:0% + +State and uh also + + align:start position:0% +State and uh also + + + align:start position:0% +State and uh also +include + + align:start position:0% +include + + + align:start position:0% +include +also two particle state + + align:start position:0% + + + + align:start position:0% + +except + + align:start position:0% +except + + + align:start position:0% +except +okay and look at Connected green + + align:start position:0% + + + + align:start position:0% + +function + + align:start position:0% + + + + align:start position:0% + +okay yeah just realistically when I + + align:start position:0% +okay yeah just realistically when I + + + align:start position:0% +okay yeah just realistically when I +insert the complete set of State I can + + align:start position:0% +insert the complete set of State I can + + + align:start position:0% +insert the complete set of State I can +insert off like that + + align:start position:0% +insert off like that + + + align:start position:0% +insert off like that +so now now let's look at the scaling so + + align:start position:0% +so now now let's look at the scaling so + + + align:start position:0% +so now now let's look at the scaling so +this guy according to + + align:start position:0% +this guy according to + + + align:start position:0% +this guy according to +our general Behavior should scale as + + align:start position:0% +our general Behavior should scale as + + + align:start position:0% +our general Behavior should scale as +one/ + + align:start position:0% +one/ + + + align:start position:0% +one/ +n okay so this guy is indeed scale as + + align:start position:0% +n okay so this guy is indeed scale as + + + align:start position:0% +n okay so this guy is indeed scale as +one so two point function scales as one + + align:start position:0% +one so two point function scales as one + + + align:start position:0% +one so two point function scales as one +and to the power zero and this guy and + + align:start position:0% +and to the power zero and this guy and + + + align:start position:0% +and to the power zero and this guy and +this guy scales as to the^ minus + + align:start position:0% + + + + align:start position:0% + +one so so this term is okay so insertion + + align:start position:0% +one so so this term is okay so insertion + + + align:start position:0% +one so so this term is okay so insertion +of the single particle state is + + align:start position:0% +of the single particle state is + + + align:start position:0% +of the single particle state is +okay but now this will give you a higher + + align:start position:0% +okay but now this will give you a higher + + + align:start position:0% +okay but now this will give you a higher +order contribution because this + + align:start position:0% +order contribution because this + + + align:start position:0% +order contribution because this +scales as equal to minus one and this + + align:start position:0% +scales as equal to minus one and this + + + align:start position:0% +scales as equal to minus one and this +scale as equal to minus 2 so all + + align:start position:0% +scale as equal to minus 2 so all + + + align:start position:0% +scale as equal to minus 2 so all +together this contribute to n to the + + align:start position:0% +together this contribute to n to the + + + align:start position:0% +together this contribute to n to the +minus + + align:start position:0% +minus + + + align:start position:0% +minus +3 okay so so the contribution of the two + + align:start position:0% +3 okay so so the contribution of the two + + + align:start position:0% +3 okay so so the contribution of the two +particle State then will be suppressed + + align:start position:0% +particle State then will be suppressed + + + align:start position:0% +particle State then will be suppressed +compared to the contribution of the + + align:start position:0% +compared to the contribution of the + + + align:start position:0% +compared to the contribution of the +single particle State and similarly with + + align:start position:0% +single particle State and similarly with + + + align:start position:0% +single particle State and similarly with +higher even higher even more particle + + align:start position:0% +higher even higher even more particle + + + align:start position:0% +higher even higher even more particle +States + + align:start position:0% +States + + + align:start position:0% +States +okay so so if I draw a + + align:start position:0% +okay so so if I draw a + + + align:start position:0% +okay so so if I draw a +diagram this process is like the + + align:start position:0% +diagram this process is like the + + + align:start position:0% +diagram this process is like the +following you said I can start with + + align:start position:0% +following you said I can start with + + + align:start position:0% +following you said I can start with +one and this one can can say turn into I + + align:start position:0% +one and this one can can say turn into I + + + align:start position:0% +one and this one can can say turn into I +through a two-point + + align:start position:0% +through a two-point + + + align:start position:0% +through a two-point +function and then this I can go to two + + align:start position:0% +function and then this I can go to two + + + align:start position:0% +function and then this I can go to two +and three + + align:start position:0% + + + + align:start position:0% + +okay so this is a true level + + align:start position:0% +okay so this is a true level + + + align:start position:0% +okay so this is a true level +process and this is like the following + + align:start position:0% +process and this is like the following + + + align:start position:0% +process and this is like the following +so this is a two particle state so so + + align:start position:0% +so this is a two particle state so so + + + align:start position:0% +so this is a two particle state so so +this if I draw a diagram will be like if + + align:start position:0% +this if I draw a diagram will be like if + + + align:start position:0% +this if I draw a diagram will be like if +I start with one and then this one can + + align:start position:0% +I start with one and then this one can + + + align:start position:0% +I start with one and then this one can +split into + + align:start position:0% +split into + + + align:start position:0% +split into +IJ and then then this a combine into two + + align:start position:0% + + + + align:start position:0% + +three okay so this is like one Loop + + align:start position:0% +three okay so this is like one Loop + + + align:start position:0% +three okay so this is like one Loop +process okay and this we see is n to + + align:start position:0% +process okay and this we see is n to + + + align:start position:0% +process okay and this we see is n to +Theus 3 and this is indeed just n to + + align:start position:0% +Theus 3 and this is indeed just n to + + + align:start position:0% +Theus 3 and this is indeed just n to +Theus one so this is surprise compared + + align:start position:0% +Theus one so this is surprise compared + + + align:start position:0% +Theus one so this is surprise compared +to + + align:start position:0% +to + + + align:start position:0% +to +that so so this is a direct way to + + align:start position:0% +that so so this is a direct way to + + + align:start position:0% +that so so this is a direct way to +say that in this kind of in this kind to + + align:start position:0% +say that in this kind of in this kind to + + + align:start position:0% +say that in this kind of in this kind to +lead in order indeed there can only + + align:start position:0% +lead in order indeed there can only + + + align:start position:0% +lead in order indeed there can only +three level processes you can never have + + align:start position:0% +three level processes you can never have + + + align:start position:0% +three level processes you can never have +this kind of Loops because whenever you + + align:start position:0% +this kind of Loops because whenever you + + + align:start position:0% +this kind of Loops because whenever you +have a loop then corresponding you must + + align:start position:0% +have a loop then corresponding you must + + + align:start position:0% +have a loop then corresponding you must +have a multi particle you must have + + align:start position:0% +have a multi particle you must have + + + align:start position:0% +have a multi particle you must have +multi particle intermediate States and + + align:start position:0% +multi particle intermediate States and + + + align:start position:0% +multi particle intermediate States and +then they surprised by + + align:start position:0% +then they surprised by + + + align:start position:0% +then they surprised by +login is it + + align:start position:0% +login is it + + + align:start position:0% +login is it +clear so so this tells + + align:start position:0% +clear so so this tells + + + align:start position:0% +clear so so this tells +you that all + + align:start position:0% +you that all + + + align:start position:0% +you that all +Loops are + + align:start position:0% + + + + align:start position:0% + +suppressed and so so a BC + + align:start position:0% +suppressed and so so a BC + + + align:start position:0% +suppressed and so so a BC +together so this a BC together then + + align:start position:0% +together so this a BC together then + + + align:start position:0% +together so this a BC together then +justify the + + align:start position:0% +justify the + + + align:start position:0% +justify the +statement that to Leading order this SC + + align:start position:0% +statement that to Leading order this SC + + + align:start position:0% +statement that to Leading order this SC +this scattering + + align:start position:0% +this scattering + + + align:start position:0% +this scattering +amplitude involving only two level when + + align:start position:0% +amplitude involving only two level when + + + align:start position:0% +amplitude involving only two level when +you have only a Tre level scattering + + align:start position:0% +you have only a Tre level scattering + + + align:start position:0% +you have only a Tre level scattering +then this is like a classical uh story + + align:start position:0% +then this is like a classical uh story + + + align:start position:0% +then this is like a classical uh story +only as you Lear in Quantum fil the + + align:start position:0% +only as you Lear in Quantum fil the + + + align:start position:0% +only as you Lear in Quantum fil the +loops is the can be consider as Quantum + + align:start position:0% +loops is the can be consider as Quantum + + + align:start position:0% +loops is the can be consider as Quantum +fluctuations and if you only have trees + + align:start position:0% +fluctuations and if you only have trees + + + align:start position:0% +fluctuations and if you only have trees +it's essentially just a classical + + align:start position:0% +it's essentially just a classical + + + align:start position:0% +it's essentially just a classical +process so when you solve the classical + + align:start position:0% +process so when you solve the classical + + + align:start position:0% +process so when you solve the classical +equation motion and what you get is the + + align:start position:0% +equation motion and what you get is the + + + align:start position:0% +equation motion and what you get is the +three level processes + + align:start position:0% +three level processes + + + align:start position:0% +three level processes +okay yes what is the number of + + align:start position:0% +okay yes what is the number of + + + align:start position:0% +okay yes what is the number of +operators H what is the number of + + align:start position:0% +operators H what is the number of + + + align:start position:0% +operators H what is the number of +operator in the right SC + + align:start position:0% +operator in the right SC + + + align:start position:0% +operator in the right SC +oh that's a very good question and + + align:start position:0% +oh that's a very good question and + + + align:start position:0% +oh that's a very good question and +essentially the by definition such + + align:start position:0% +essentially the by definition such + + + align:start position:0% +essentially the by definition such +operate only + + align:start position:0% +operate only + + + align:start position:0% +operate only +scales essentially by definition those + + align:start position:0% +scales essentially by definition those + + + align:start position:0% +scales essentially by definition those +operate such kind of So-Cal single + + align:start position:0% +operate such kind of So-Cal single + + + align:start position:0% +operate such kind of So-Cal single +Choice operators and they the scales at + + align:start position:0% +Choice operators and they the scales at + + + align:start position:0% +Choice operators and they the scales at +all the one yeah there's no um + + align:start position:0% +all the one yeah there's no um + + + align:start position:0% +all the one yeah there's no um +yeah just the way you can make such + + align:start position:0% +yeah just the way you can make such + + + align:start position:0% +yeah just the way you can make such +single trace operator is not + + align:start position:0% +single trace operator is not + + + align:start position:0% +single trace operator is not +proportional to + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +questions what is each of these terms + + align:start position:0% +questions what is each of these terms + + + align:start position:0% +questions what is each of these terms +individually small but when you take + + align:start position:0% +individually small but when you take + + + align:start position:0% +individually small but when you take +make summation over them yeah yeah + + align:start position:0% +make summation over them yeah yeah + + + align:start position:0% +make summation over them yeah yeah +that's a question was just asked um so + + align:start position:0% +that's a question was just asked um so + + + align:start position:0% +that's a question was just asked um so +so those operators if you count + + align:start position:0% +so those operators if you count + + + align:start position:0% +so those operators if you count +them at the number of single TR operator + + align:start position:0% +them at the number of single TR operator + + + align:start position:0% +them at the number of single TR operator +you can + + align:start position:0% +you can + + + align:start position:0% +you can +construct is the is independent of + + align:start position:0% +construct is the is independent of + + + align:start position:0% +construct is the is independent of +n uh and so so when you suppress them by + + align:start position:0% +n uh and so so when you suppress them by + + + align:start position:0% +n uh and so so when you suppress them by +n and there's nothing you can compensate + + align:start position:0% +n and there's nothing you can compensate + + + align:start position:0% +n and there's nothing you can compensate +them uh in principle yeah uh uh there's + + align:start position:0% +them uh in principle yeah uh uh there's + + + align:start position:0% +them uh in principle yeah uh uh there's +nothing can compensate them so yeah so + + align:start position:0% +nothing can compensate them so yeah so + + + align:start position:0% +nothing can compensate them so yeah so +like how many you know how many + + align:start position:0% +like how many you know how many + + + align:start position:0% +like how many you know how many +operators that are like um + + align:start position:0% +operators that are like um + + + align:start position:0% +operators that are like um +OJ can you construct like what is the + + align:start position:0% +OJ can you construct like what is the + + + align:start position:0% +OJ can you construct like what is the +magnitude oh it's infinite number of + + align:start position:0% +magnitude oh it's infinite number of + + + align:start position:0% +magnitude oh it's infinite number of +them right it's infinite number of them + + align:start position:0% +them right it's infinite number of them + + + align:start position:0% +them right it's infinite number of them +but the key + + align:start position:0% +but the key + + + align:start position:0% +but the key +is the + + align:start position:0% +is the + + + align:start position:0% +is the +infinite + + align:start position:0% +infinite + + + align:start position:0% +infinite +compare it's a factor we yeah it's a + + align:start position:0% +compare it's a factor we yeah it's a + + + align:start position:0% +compare it's a factor we yeah it's a +infinite is it's + + align:start position:0% + + + + align:start position:0% + +infinite but compared to the lar limit + + align:start position:0% +infinite but compared to the lar limit + + + align:start position:0% +infinite but compared to the lar limit +is still all + + align:start position:0% + + + + align:start position:0% + +one it's + + align:start position:0% +one it's + + + align:start position:0% +one it's +infinite it's + + align:start position:0% +infinite it's + + + align:start position:0% +infinite it's +infinite but it's all the N to the power + + align:start position:0% +infinite but it's all the N to the power + + + align:start position:0% +infinite but it's all the N to the power +zero oh my God all right it's add m to + + align:start position:0% +zero oh my God all right it's add m to + + + align:start position:0% +zero oh my God all right it's add m to +the power zero okay and uh + + align:start position:0% +the power zero okay and uh + + + align:start position:0% +the power zero okay and uh +so but they will be + + align:start position:0% +so but they will be + + + align:start position:0% +so but they will be +suppressed by + + align:start position:0% +suppressed by + + + align:start position:0% +suppressed by +physical they will be surprised by + + align:start position:0% +physical they will be surprised by + + + align:start position:0% +physical they will be surprised by +physical process say for example say + + align:start position:0% +physical process say for example say + + + align:start position:0% +physical process say for example say +this operator it's a box or something + + align:start position:0% +this operator it's a box or something + + + align:start position:0% +this operator it's a box or something +say have some Dimension say say this + + align:start position:0% +say have some Dimension say say this + + + align:start position:0% +say have some Dimension say say this +operator say suppose this particle one + + align:start position:0% +operator say suppose this particle one + + + align:start position:0% +operator say suppose this particle one +have some + + align:start position:0% +have some + + + align:start position:0% +have some +energy and uh and particle has some + + align:start position:0% +energy and uh and particle has some + + + align:start position:0% +energy and uh and particle has some +energy and then the process of this + + align:start position:0% +energy and then the process of this + + + align:start position:0% +energy and then the process of this +generate this two and when they are then + + align:start position:0% +generate this two and when they are then + + + align:start position:0% +generate this two and when they are then +when their energy become very large then + + align:start position:0% +when their energy become very large then + + + align:start position:0% +when their energy become very large then +it's suppressed and uh and and you have + + align:start position:0% +it's suppressed and uh and and you have + + + align:start position:0% +it's suppressed and uh and and you have +this kind of physical suppression of + + align:start position:0% +this kind of physical suppression of + + + align:start position:0% +this kind of physical suppression of +course if you include all all energies + + align:start position:0% +course if you include all all energies + + + align:start position:0% +course if you include all all energies +the infinite number of them but in + + align:start position:0% +the infinite number of them but in + + + align:start position:0% +the infinite number of them but in +effective you + + align:start position:0% +effective you + + + align:start position:0% +effective you +can if you can uh yeah energy + + align:start position:0% +can if you can uh yeah energy + + + align:start position:0% +can if you can uh yeah energy +conservation this kind of thing then + + align:start position:0% +conservation this kind of thing then + + + align:start position:0% +conservation this kind of thing then +essentially there's a fight number of + + align:start position:0% +essentially there's a fight number of + + + align:start position:0% +essentially there's a fight number of +contributes okay yeah but the key is + + align:start position:0% +contributes okay yeah but the key is + + + align:start position:0% +contributes okay yeah but the key is +that this is all n to the power zero + + align:start position:0% +that this is all n to the power zero + + + align:start position:0% +that this is all n to the power zero +just uh maybe one more thing what if it + + align:start position:0% +just uh maybe one more thing what if it + + + align:start position:0% +just uh maybe one more thing what if it +includes the loop + + align:start position:0% +includes the loop + + + align:start position:0% +includes the loop +Clos by itself yeah like a like a close + + align:start position:0% +Clos by itself yeah like a like a close + + + align:start position:0% +Clos by itself yeah like a like a close +firing Loop in QED I mean it doesn't + + align:start position:0% +firing Loop in QED I mean it doesn't + + + align:start position:0% +firing Loop in QED I mean it doesn't +need to involve multiple state it can + + align:start position:0% +need to involve multiple state it can + + + align:start position:0% +need to involve multiple state it can +just bend and then no no no Loop always + + align:start position:0% +just bend and then no no no Loop always + + + align:start position:0% +just bend and then no no no Loop always +involve partic partic States say any + + align:start position:0% +involve partic partic States say any + + + align:start position:0% +involve partic partic States say any +Loop when you cross it there's always + + align:start position:0% +Loop when you cross it there's always + + + align:start position:0% +Loop when you cross it there's always +two states we don't need to cross it at + + align:start position:0% +two states we don't need to cross it at + + + align:start position:0% +two states we don't need to cross it at +the end I mean + + align:start position:0% +the end I mean + + + align:start position:0% +the end I mean +like so sorry I don't quite understand + + align:start position:0% +like so sorry I don't quite understand + + + align:start position:0% +like so sorry I don't quite understand +any + + align:start position:0% +any + + + align:start position:0% +any +Loop any Loop move by definition when + + align:start position:0% +Loop any Loop move by definition when + + + align:start position:0% +Loop any Loop move by definition when +you cross it there's always two points + + align:start position:0% +you cross it there's always two points + + + align:start position:0% +you cross it there's always two points +then that means this is more than one + + align:start position:0% +then that means this is more than one + + + align:start position:0% +then that means this is more than one +particle uh just something like this + + align:start position:0% +particle uh just something like this + + + align:start position:0% +particle uh just something like this +don't cross any no no no no no you cross + + align:start position:0% +don't cross any no no no no no you cross + + + align:start position:0% +don't cross any no no no no no you cross +here you still have two particle right + + align:start position:0% +here you still have two particle right + + + align:start position:0% +here you still have two particle right +cut okay yeah you cut at any time there + + align:start position:0% +cut okay yeah you cut at any time there + + + align:start position:0% +cut okay yeah you cut at any time there +still two particle + + align:start position:0% + + + + align:start position:0% + +yeah uh okay let's + + align:start position:0% +yeah uh okay let's + + + align:start position:0% +yeah uh okay let's +summarize so now let's combine 1 2 three + + align:start position:0% + + + + align:start position:0% + +so we can combine 1 2 + + align:start position:0% +so we can combine 1 2 + + + align:start position:0% +so we can combine 1 2 +3 so this tells + + align:start position:0% +3 so this tells + + + align:start position:0% +3 so this tells +us so this 1 2 3 tells us at leading + + align:start position:0% +us so this 1 2 3 tells us at leading + + + align:start position:0% +us so this 1 2 3 tells us at leading +order in + + align:start position:0% + + + + align:start position:0% + +expansion we have a + + align:start position:0% + + + + align:start position:0% + +theory a classical Theory + + align:start position:0% + + + + align:start position:0% + +we essentially just have a + + align:start position:0% +we essentially just have a + + + align:start position:0% +we essentially just have a +CL we have a classic C of + + align:start position:0% + + + + align:start position:0% + +gloos you just have a bunch of particles + + align:start position:0% +gloos you just have a bunch of particles + + + align:start position:0% +gloos you just have a bunch of particles +and they interact classically uh there's + + align:start position:0% +and they interact classically uh there's + + + align:start position:0% +and they interact classically uh there's +no Quantum + + align:start position:0% +no Quantum + + + align:start position:0% +no Quantum +fluctuations and with + + align:start position:0% + + + + align:start position:0% + +interactions among + + align:start position:0% + + + + align:start position:0% + +globos among them + + align:start position:0% +globos among them + + + align:start position:0% +globos among them +given + + align:start position:0% + + + + align:start position:0% + +by some effective component which I + + align:start position:0% +by some effective component which I + + + align:start position:0% +by some effective component which I +called G Thea which scales at 1 / + + align:start position:0% +called G Thea which scales at 1 / + + + align:start position:0% +called G Thea which scales at 1 / +n okay scales at 1 / + + align:start position:0% + + + + align:start position:0% + +n so so let me just elaborate this + + align:start position:0% +n so so let me just elaborate this + + + align:start position:0% +n so so let me just elaborate this +statement a little bit more so this can + + align:start position:0% +statement a little bit more so this can + + + align:start position:0% +statement a little bit more so this can +be considered as say when we take a gaug + + align:start position:0% +be considered as say when we take a gaug + + + align:start position:0% +be considered as say when we take a gaug +theory say for example yam + + align:start position:0% +theory say for example yam + + + align:start position:0% +theory say for example yam +Theory say QC + + align:start position:0% +Theory say QC + + + align:start position:0% +Theory say QC +B you take angle to Infinity + + align:start position:0% +B you take angle to Infinity + + + align:start position:0% +B you take angle to Infinity +limit and you take H bar + + align:start position:0% +limit and you take H bar + + + align:start position:0% +limit and you take H bar +finite so by definition when we talk + + align:start position:0% +finite so by definition when we talk + + + align:start position:0% +finite so by definition when we talk +about this Ser H bar is always + + align:start position:0% +about this Ser H bar is always + + + align:start position:0% +about this Ser H bar is always +finite but in any equal to Infinity + + align:start position:0% +finite but in any equal to Infinity + + + align:start position:0% +finite but in any equal to Infinity +limit this is + + align:start position:0% +limit this is + + + align:start position:0% +limit this is +equivalent to a global + + align:start position:0% + + + + align:start position:0% + +Theory with h by Thea goes to + + align:start position:0% +Theory with h by Thea goes to + + + align:start position:0% +Theory with h by Thea goes to +zero okay so you get the classical the + + align:start position:0% +zero okay so you get the classical the + + + align:start position:0% +zero okay so you get the classical the +and with effective + + align:start position:0% +and with effective + + + align:start position:0% +and with effective +H H by Thea which is contr essentially + + align:start position:0% +H H by Thea which is contr essentially + + + align:start position:0% +H H by Thea which is contr essentially +by one of n goes to + + align:start position:0% +by one of n goes to + + + align:start position:0% +by one of n goes to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +okay so so here you can do pive + + align:start position:0% +okay so so here you can do pive + + + align:start position:0% +okay so so here you can do pive +expansion One + + align:start position:0% + + + + align:start position:0% + +n so this is just a leading order here + + align:start position:0% +n so this is just a leading order here + + + align:start position:0% +n so this is just a leading order here +you can do poity + + align:start position:0% + + + + align:start position:0% + +expansion in one / n + + align:start position:0% + + + + align:start position:0% + +so in this site it's like some kind of + + align:start position:0% +so in this site it's like some kind of + + + align:start position:0% +so in this site it's like some kind of +semil classical + + align:start position:0% + + + + align:start position:0% + +expansion in this H + + align:start position:0% +expansion in this H + + + align:start position:0% +expansion in this H +theoda which is of course should be + + align:start position:0% +theoda which is of course should be + + + align:start position:0% +theoda which is of course should be +scale as 1 / + + align:start position:0% +scale as 1 / + + + align:start position:0% +scale as 1 / +n okay so so on this side when H bar + + align:start position:0% +n okay so so on this side when H bar + + + align:start position:0% +n okay so so on this side when H bar +goes H bar TAA goes zero because you + + align:start position:0% +goes H bar TAA goes zero because you + + + align:start position:0% +goes H bar TAA goes zero because you +have a classical Theory but then you can + + align:start position:0% +have a classical Theory but then you can + + + align:start position:0% +have a classical Theory but then you can +do uh do expansion H TAA so this what we + + align:start position:0% +do uh do expansion H TAA so this what we + + + align:start position:0% +do uh do expansion H TAA so this what we +normally call semiclassical + + align:start position:0% +normally call semiclassical + + + align:start position:0% +normally call semiclassical +expansion okay so so the so the Lan + + align:start position:0% +expansion okay so so the so the Lan + + + align:start position:0% +expansion okay so so the so the Lan +expansion then translate into some semi + + align:start position:0% +expansion then translate into some semi + + + align:start position:0% +expansion then translate into some semi +classical uh expansion when you + + align:start position:0% +classical uh expansion when you + + + align:start position:0% +classical uh expansion when you +translate into this Global + + align:start position:0% + + + + align:start position:0% + +language and we will + + align:start position:0% +language and we will + + + align:start position:0% +language and we will +now so is this clear yeah this is a + + align:start position:0% +now so is this clear yeah this is a + + + align:start position:0% +now so is this clear yeah this is a +little bit small corner is it is it + + align:start position:0% + + + + align:start position:0% + +readable yeah uh this is a very + + align:start position:0% +readable yeah uh this is a very + + + align:start position:0% +readable yeah uh this is a very +important statement maybe I should + + align:start position:0% +important statement maybe I should + + + align:start position:0% +important statement maybe I should +rewrite it um yeah let me just re + + align:start position:0% +rewrite it um yeah let me just re + + + align:start position:0% +rewrite it um yeah let me just re +rewrite + + align:start position:0% +rewrite + + + align:start position:0% +rewrite +it so fortive + + align:start position:0% + + + + align:start position:0% + +expansion fortive pation in n in one / n + + align:start position:0% +expansion fortive pation in n in one / n + + + align:start position:0% +expansion fortive pation in n in one / n +so this is equal + + align:start position:0% + + + + align:start position:0% + +to semi + + align:start position:0% + + + + align:start position:0% + +classical classical + + align:start position:0% + + + + align:start position:0% + +expansion in h by TAA H + + align:start position:0% +expansion in h by TAA H + + + align:start position:0% +expansion in h by TAA H +scale + + align:start position:0% + + + + align:start position:0% + +okay and we will now + + align:start position:0% + + + + align:start position:0% + +show that this guys this Global Theory + + align:start position:0% +show that this guys this Global Theory + + + align:start position:0% +show that this guys this Global Theory +and this semi classical + + align:start position:0% + + + + align:start position:0% + +expansion is actually a string + + align:start position:0% +expansion is actually a string + + + align:start position:0% +expansion is actually a string +theory okay now I will not show that I + + align:start position:0% +theory okay now I will not show that I + + + align:start position:0% +theory okay now I will not show that I +say I will motivate that uh I say that's + + align:start position:0% +say I will motivate that uh I say that's + + + align:start position:0% +say I will motivate that uh I say that's +a stren + + align:start position:0% +a stren + + + align:start position:0% +a stren +theory so so before I go that uh do you + + align:start position:0% +theory so so before I go that uh do you + + + align:start position:0% +theory so so before I go that uh do you +have any + + align:start position:0% +have any + + + align:start position:0% +have any +questions yes just to clarify I mean you + + align:start position:0% +questions yes just to clarify I mean you + + + align:start position:0% +questions yes just to clarify I mean you +I doesn't the sort of second statement + + align:start position:0% +I doesn't the sort of second statement + + + align:start position:0% +I doesn't the sort of second statement +like the fact that perturbation one of R + + align:start position:0% +like the fact that perturbation one of R + + + align:start position:0% +like the fact that perturbation one of R +corresponds to semic classical expansion + + align:start position:0% +corresponds to semic classical expansion + + + align:start position:0% +corresponds to semic classical expansion +in H part it like isn't that just more a + + align:start position:0% +in H part it like isn't that just more a + + + align:start position:0% +in H part it like isn't that just more a +generalization of the thing you just + + align:start position:0% +generalization of the thing you just + + + align:start position:0% +generalization of the thing you just +wrote like you really it's the same + + align:start position:0% +wrote like you really it's the same + + + align:start position:0% +wrote like you really it's the same +statement yeah it's the same statement + + align:start position:0% +statement yeah it's the same statement + + + align:start position:0% +statement yeah it's the same statement +no no no these two statement they are + + align:start position:0% +no no no these two statement they are + + + align:start position:0% +no no no these two statement they are +basically the + + align:start position:0% +basically the + + + align:start position:0% +basically the +same they're not equivalent this is + + align:start position:0% +same they're not equivalent this is + + + align:start position:0% +same they're not equivalent this is +talking about this particular limit okay + + align:start position:0% +talking about this particular limit okay + + + align:start position:0% +talking about this particular limit okay +this is talking about this particular + + align:start position:0% +this is talking about this particular + + + align:start position:0% +this is talking about this particular +limit and this tells you what happens we + + align:start position:0% +limit and this tells you what happens we + + + align:start position:0% +limit and this tells you what happens we +will relax this limit by including the + + align:start position:0% +will relax this limit by including the + + + align:start position:0% +will relax this limit by including the +including F any fact by one n expansion + + align:start position:0% +including F any fact by one n expansion + + + align:start position:0% +including F any fact by one n expansion +and and to make this + + align:start position:0% +and and to make this + + + align:start position:0% +and and to make this +identification so this by itself does + + align:start position:0% +identification so this by itself does + + + align:start position:0% +identification so this by itself does +not imply that because the other way + + align:start position:0% +not imply that because the other way + + + align:start position:0% +not imply that because the other way +does right yeah goes the other way does + + align:start position:0% +does right yeah goes the other way does + + + align:start position:0% +does right yeah goes the other way does +so this is a stronger statement right + + align:start position:0% +so this is a stronger statement right + + + align:start position:0% +so this is a stronger statement right +okay yeah and this + + align:start position:0% +okay yeah and this + + + align:start position:0% +okay yeah and this +statement is supported by just looking + + align:start position:0% +statement is supported by just looking + + + align:start position:0% +statement is supported by just looking +at the leading order Behavior but if you + + align:start position:0% +at the leading order Behavior but if you + + + align:start position:0% +at the leading order Behavior but if you +want to look at but if you want to look + + align:start position:0% +want to look at but if you want to look + + + align:start position:0% +want to look at but if you want to look +at this behavior and then you look at + + align:start position:0% +at this behavior and then you look at + + + align:start position:0% +at this behavior and then you look at +then then you need to look at the sub + + align:start position:0% +then then you need to look at the sub + + + align:start position:0% +then then you need to look at the sub +leing term in one / n say for example + + align:start position:0% +leing term in one / n say for example + + + align:start position:0% +leing term in one / n say for example +here + + align:start position:0% +here + + + align:start position:0% +here +then you see the + + align:start position:0% +then you see the + + + align:start position:0% +then you see the +fluctuation is controlled by one n this + + align:start position:0% +fluctuation is controlled by one n this + + + align:start position:0% +fluctuation is controlled by one n this +negative fluctuation is controlled by H + + align:start position:0% +negative fluctuation is controlled by H + + + align:start position:0% +negative fluctuation is controlled by H +bar and and the similarly here then then + + align:start position:0% +bar and and the similarly here then then + + + align:start position:0% +bar and and the similarly here then then +when you include one of any fact then + + align:start position:0% +when you include one of any fact then + + + align:start position:0% +when you include one of any fact then +you will see single particle now and the + + align:start position:0% +you will see single particle now and the + + + align:start position:0% +you will see single particle now and the +m and the two particle multi particle + + align:start position:0% +m and the two particle multi particle + + + align:start position:0% +m and the two particle multi particle +they can mix together due to + + align:start position:0% +they can mix together due to + + + align:start position:0% +they can mix together due to +fluctuations and again that amplitude is + + align:start position:0% +fluctuations and again that amplitude is + + + align:start position:0% +fluctuations and again that amplitude is +controlled by one n exact yeah just say + + align:start position:0% +controlled by one n exact yeah just say + + + align:start position:0% +controlled by one n exact yeah just say +this statement is is stronger you need + + align:start position:0% +this statement is is stronger you need + + + align:start position:0% +this statement is is stronger you need +to look at the subing fractions + + align:start position:0% +to look at the subing fractions + + + align:start position:0% +to look at the subing fractions +carefully and you see that fits into a h + + align:start position:0% +carefully and you see that fits into a h + + + align:start position:0% +carefully and you see that fits into a h +bar pattern + + align:start position:0% + + + + align:start position:0% + +yeah yes so instead of this operators we + + align:start position:0% +yeah yes so instead of this operators we + + + align:start position:0% +yeah yes so instead of this operators we +consider regular creation destruction + + align:start position:0% +consider regular creation destruction + + + align:start position:0% +consider regular creation destruction +operators we still come to the + + align:start position:0% +operators we still come to the + + + align:start position:0% +operators we still come to the +conclusion that all the gr diagrams are + + align:start position:0% +conclusion that all the gr diagrams are + + + align:start position:0% +conclusion that all the gr diagrams are +stressed yeah that's a good point so in + + align:start position:0% +stressed yeah that's a good point so in + + + align:start position:0% +stressed yeah that's a good point so in +essence you can imagine this o oi each + + align:start position:0% +essence you can imagine this o oi each + + + align:start position:0% +essence you can imagine this o oi each +oi def + + align:start position:0% +oi def + + + align:start position:0% +oi def +defines this point one is precisely this + + align:start position:0% +defines this point one is precisely this + + + align:start position:0% +defines this point one is precisely this +statement is that you can imagine each + + align:start position:0% +statement is that you can imagine each + + + align:start position:0% +statement is that you can imagine each +oi defines a creation defines + + align:start position:0% +oi defines a creation defines + + + align:start position:0% +oi defines a creation defines +independent creation and relation + + align:start position:0% +independent creation and relation + + + align:start position:0% +independent creation and relation +operator + + align:start position:0% +operator + + + align:start position:0% +operator +yeah the still + + align:start position:0% +yeah the still + + + align:start position:0% +yeah the still +have sorry no in the original Theory + + align:start position:0% +have sorry no in the original Theory + + + align:start position:0% +have sorry no in the original Theory +we're not only in N + + align:start position:0% +we're not only in N + + + align:start position:0% +we're not only in N +limit in the original theory in large we + + align:start position:0% +limit in the original theory in large we + + + align:start position:0% +limit in the original theory in large we +do have suppression no you don't have a + + align:start position:0% +do have suppression no you don't have a + + + align:start position:0% +do have suppression no you don't have a +suppression of loop diagram in terms of + + align:start position:0% +suppression of loop diagram in terms of + + + align:start position:0% +suppression of loop diagram in terms of +the standard Loops you only have the + + align:start position:0% +the standard Loops you only have the + + + align:start position:0% +the standard Loops you only have the +suppression of the loop diagram in terms + + align:start position:0% +suppression of the loop diagram in terms + + + align:start position:0% +suppression of the loop diagram in terms +of those Loops in terms of Loops of + + align:start position:0% +of those Loops in terms of Loops of + + + align:start position:0% +of those Loops in terms of Loops of +globos but here we don't specify like + + align:start position:0% +globos but here we don't specify like + + + align:start position:0% +globos but here we don't specify like +don't put any restrictions on what are + + align:start position:0% +don't put any restrictions on what are + + + align:start position:0% +don't put any restrictions on what are +the operators o so why can't we say just + + align:start position:0% +the operators o so why can't we say just + + + align:start position:0% +the operators o so why can't we say just +o i is just side side I no no no o is + + align:start position:0% +o i is just side side I no no no o is + + + align:start position:0% +o i is just side side I no no no o is +gaging varant operator o is composite + + align:start position:0% +gaging varant operator o is composite + + + align:start position:0% +gaging varant operator o is composite +operator or is some composite operator + + align:start position:0% +operator or is some composite operator + + + align:start position:0% +operator or is some composite operator +so so for example in the in the yam the + + align:start position:0% +so so for example in the in the yam the + + + align:start position:0% +so so for example in the in the yam the +so one example is O can be Chace F + + align:start position:0% +so one example is O can be Chace F + + + align:start position:0% +so one example is O can be Chace F +squ so if you look at the twoo function + + align:start position:0% +squ so if you look at the twoo function + + + align:start position:0% +squ so if you look at the twoo function +of O then that corresponding to two Glon + + align:start position:0% + + + + align:start position:0% + +propagators two Glon propagators and so + + align:start position:0% +propagators two Glon propagators and so + + + align:start position:0% +propagators two Glon propagators and so +you have loops + + align:start position:0% +you have loops + + + align:start position:0% +you have loops +here but but this is not the loop in + + align:start position:0% +here but but this is not the loop in + + + align:start position:0% +here but but this is not the loop in +terms of the globall here when we talk + + align:start position:0% +terms of the globall here when we talk + + + align:start position:0% +terms of the globall here when we talk +about + + align:start position:0% +about + + + align:start position:0% +about +loops yeah so let me emphasize all Loops + + align:start position:0% +loops yeah so let me emphasize all Loops + + + align:start position:0% +loops yeah so let me emphasize all Loops +of global + + align:start position:0% + + + + align:start position:0% + +because here so the key of this + + align:start position:0% +because here so the key of this + + + align:start position:0% +because here so the key of this +statement is that in the Lan limit and + + align:start position:0% +statement is that in the Lan limit and + + + align:start position:0% +statement is that in the Lan limit and +if you + + align:start position:0% +if you + + + align:start position:0% +if you +consider if our thing is caging + + align:start position:0% +consider if our thing is caging + + + align:start position:0% +consider if our thing is caging +operators then that's the AIC you should + + align:start position:0% +operators then that's the AIC you should + + + align:start position:0% +operators then that's the AIC you should +consider and and you should not worry + + align:start position:0% +consider and and you should not worry + + + align:start position:0% +consider and and you should not worry +about the original stuff and those they + + align:start position:0% +about the original stuff and those they + + + align:start position:0% +about the original stuff and those they +have loops Etc have fin H bar Etc but in + + align:start position:0% +have loops Etc have fin H bar Etc but in + + + align:start position:0% +have loops Etc have fin H bar Etc but in +terms of the in terms of those gloal + + align:start position:0% +terms of the in terms of those gloal + + + align:start position:0% +terms of the in terms of those gloal +then you have a classical Theory there's + + align:start position:0% +then you have a classical Theory there's + + + align:start position:0% +then you have a classical Theory there's +no Loops you only have two level + + align:start position:0% +no Loops you only have two level + + + align:start position:0% +no Loops you only have two level +scattering in the lar limit + + align:start position:0% +scattering in the lar limit + + + align:start position:0% +scattering in the lar limit +yes uh so are we talking about a general + + align:start position:0% +yes uh so are we talking about a general + + + align:start position:0% +yes uh so are we talking about a general +like gaug and variant operators or + + align:start position:0% +like gaug and variant operators or + + + align:start position:0% +like gaug and variant operators or +explicitly single + + align:start position:0% +explicitly single + + + align:start position:0% +explicitly single +operators no no no I have to talk about + + align:start position:0% +operators no no no I have to talk about + + + align:start position:0% +operators no no no I have to talk about +everything okay so I mean like the the + + align:start position:0% +everything okay so I mean like the the + + + align:start position:0% +everything okay so I mean like the the +single a single o operator is can be + + align:start position:0% +single a single o operator is can be + + + align:start position:0% +single a single o operator is can be +several traces no no no single O is a + + align:start position:0% +several traces no no no single O is a + + + align:start position:0% +several traces no no no single O is a +single trace no single O is a single + + align:start position:0% +single trace no single O is a single + + + align:start position:0% +single trace no single O is a single +trace that defined there what about like + + align:start position:0% +trace that defined there what about like + + + align:start position:0% +trace that defined there what about like +non-ra gaug variance operators we don't + + align:start position:0% +non-ra gaug variance operators we don't + + + align:start position:0% +non-ra gaug variance operators we don't +consider + + align:start position:0% +consider + + + align:start position:0% +consider +them you mean non gaug ining operator + + align:start position:0% +them you mean non gaug ining operator + + + align:start position:0% +them you mean non gaug ining operator +now every gaug in operator always + + align:start position:0% +now every gaug in operator always + + + align:start position:0% +now every gaug in operator always +involve Chace yeah + + align:start position:0% +involve Chace yeah + + + align:start position:0% +involve Chace yeah +sure you will be a famous mathematician + + align:start position:0% +sure you will be a famous mathematician + + + align:start position:0% +sure you will be a famous mathematician +if you can construct something in warant + + align:start position:0% +if you can construct something in warant + + + align:start position:0% +if you can construct something in warant +which does not involve + + align:start position:0% +which does not involve + + + align:start position:0% +which does not involve +Choice yeah construct something about + + align:start position:0% +Choice yeah construct something about + + + align:start position:0% +Choice yeah construct something about +the Matrix yeah use + + align:start position:0% +the Matrix yeah use + + + align:start position:0% +the Matrix yeah use +something construct something using + + align:start position:0% +something construct something using + + + align:start position:0% +something construct something using +matrices which does not involve in + + align:start position:0% +matrices which does not involve in + + + align:start position:0% +matrices which does not involve in +traces yeah even if you do determinant + + align:start position:0% +traces yeah even if you do determinant + + + align:start position:0% +traces yeah even if you do determinant +and determinant can still be written as + + align:start position:0% +and determinant can still be written as + + + align:start position:0% +and determinant can still be written as +traces and yeah yeah just everything can + + align:start position:0% +traces and yeah yeah just everything can + + + align:start position:0% +traces and yeah yeah just everything can +be written as + + align:start position:0% +be written as + + + align:start position:0% +be written as +CH so determinant would just have if you + + align:start position:0% +CH so determinant would just have if you + + + align:start position:0% +CH so determinant would just have if you +have a determinant operator that can + + align:start position:0% +have a determinant operator that can + + + align:start position:0% +have a determinant operator that can +just be written as like a product of + + align:start position:0% +just be written as like a product of + + + align:start position:0% +just be written as like a product of +many that's right that's right that's + + align:start position:0% +many that's right that's right that's + + + align:start position:0% +many that's right that's right that's +right that's right good any other + + align:start position:0% +right that's right good any other + + + align:start position:0% +right that's right good any other +questions yes clarify we' been talking + + align:start position:0% + + + + align:start position:0% + +about yeah here we are talking about + + align:start position:0% +about yeah here we are talking about + + + align:start position:0% +about yeah here we are talking about +only every field is Matrix valued Fields + + align:start position:0% +only every field is Matrix valued Fields + + + align:start position:0% +only every field is Matrix valued Fields +yeah just every field is Matrix valued + + align:start position:0% +yeah just every field is Matrix valued + + + align:start position:0% +yeah just every field is Matrix valued +Fields yeah yes + + align:start position:0% +Fields yeah yes + + + align:start position:0% +Fields yeah yes +uh I don't know I just uh I thought + + align:start position:0% +uh I don't know I just uh I thought + + + align:start position:0% +uh I don't know I just uh I thought +there was more um invari invariance even + + align:start position:0% +there was more um invari invariance even + + + align:start position:0% +there was more um invari invariance even +construct out of a matrix um like I was + + align:start position:0% +construct out of a matrix um like I was + + + align:start position:0% +construct out of a matrix um like I was +asking you the other day um basically + + align:start position:0% +asking you the other day um basically + + + align:start position:0% +asking you the other day um basically +it's all the each one of the + + align:start position:0% +it's all the each one of the + + + align:start position:0% +it's all the each one of the +coefficients of the characteristic polom + + align:start position:0% +coefficients of the characteristic polom + + + align:start position:0% +coefficients of the characteristic polom +of a mat yeah they can written they can + + align:start position:0% +of a mat yeah they can written they can + + + align:start position:0% +of a mat yeah they can written they can +be written as + + align:start position:0% + + + + align:start position:0% + +traces yeah they can be Reas + + align:start position:0% +traces yeah they can be Reas + + + align:start position:0% +traces yeah they can be Reas +ches + + align:start position:0% +ches + + + align:start position:0% +ches +yeah case of discuss qus here yeah yeah + + align:start position:0% +yeah case of discuss qus here yeah yeah + + + align:start position:0% +yeah case of discuss qus here yeah yeah +here we have the not this quarks and + + align:start position:0% +here we have the not this quarks and + + + align:start position:0% +here we have the not this quarks and +we're going to mention quarks very + + align:start position:0% +we're going to mention quarks very + + + align:start position:0% +we're going to mention quarks very +briefly at the end + + align:start position:0% +briefly at the end + + + align:start position:0% +briefly at the end +yeah any other + + align:start position:0% + + + + align:start position:0% + +questions good good okay so now let's + + align:start position:0% +questions good good okay so now let's + + + align:start position:0% +questions good good okay so now let's +talk about a little bit about String + + align:start position:0% + + + + align:start position:0% + +Theory maybe I will leave + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% +there + + + align:start position:0% +there +that let me see where the leave that + + align:start position:0% + + + + align:start position:0% + +yeah let me leave that oh okay + + align:start position:0% + + + + align:start position:0% + +h + + align:start position:0% + + + + align:start position:0% + +so first I we talk a little bit about + + align:start position:0% +so first I we talk a little bit about + + + align:start position:0% +so first I we talk a little bit about +the + + align:start position:0% + + + + align:start position:0% + +strings so first let me remind you Q + + align:start position:0% +strings so first let me remind you Q + + + align:start position:0% +strings so first let me remind you Q +qft normally when we say a qft we say + + align:start position:0% +qft normally when we say a qft we say + + + align:start position:0% +qft normally when we say a qft we say +qft is a theory of + + align:start position:0% + + + + align:start position:0% + +particles or particles + + align:start position:0% + + + + align:start position:0% + +okay so the standard approach to the qft + + align:start position:0% +okay so the standard approach to the qft + + + align:start position:0% +okay so the standard approach to the qft +is that you write down a field + + align:start position:0% +is that you write down a field + + + align:start position:0% +is that you write down a field +Lin and then you quantize ex so this is + + align:start position:0% +Lin and then you quantize ex so this is + + + align:start position:0% +Lin and then you quantize ex so this is +normally called the second quanti so the + + align:start position:0% +normally called the second quanti so the + + + align:start position:0% +normally called the second quanti so the +standard + + align:start position:0% + + + + align:start position:0% + +approach is called second Quan approach + + align:start position:0% + + + + align:start position:0% + +second quantise approach + + align:start position:0% +second quantise approach + + + align:start position:0% +second quantise approach +okay but there also exists a first + + align:start position:0% +okay but there also exists a first + + + align:start position:0% +okay but there also exists a first +quantise + + align:start position:0% + + + + align:start position:0% + +approach there also exist a first quanti + + align:start position:0% + + + + align:start position:0% + +approach there also exist a first Quant + + align:start position:0% +approach there also exist a first Quant + + + align:start position:0% +approach there also exist a first Quant +approach is that you directly Quant + + align:start position:0% +approach is that you directly Quant + + + align:start position:0% +approach is that you directly Quant +you just + + align:start position:0% + + + + align:start position:0% + +quantize Quantum + + align:start position:0% + + + + align:start position:0% + +motion say or for a particle or + + align:start position:0% + + + + align:start position:0% + +particles say oh say say let's consider + + align:start position:0% +particles say oh say say let's consider + + + align:start position:0% +particles say oh say say let's consider +one particle say a particle in space + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +okay so for example if you can see the + + align:start position:0% +okay so for example if you can see the + + + align:start position:0% +okay so for example if you can see the +particle propagate in space time along + + align:start position:0% +particle propagate in space time along + + + align:start position:0% +particle propagate in space time along +some + + align:start position:0% +some + + + align:start position:0% +some +trajectory so this parameterize this + + align:start position:0% +trajectory so this parameterize this + + + align:start position:0% +trajectory so this parameterize this +trajectory say using a parameter by tow + + align:start position:0% +trajectory say using a parameter by tow + + + align:start position:0% +trajectory say using a parameter by tow +which label the point along the + + align:start position:0% +which label the point along the + + + align:start position:0% +which label the point along the +trajectory and then so this will give + + align:start position:0% +trajectory and then so this will give + + + align:start position:0% +trajectory and then so this will give +you a + + align:start position:0% +you a + + + align:start position:0% +you a +mapping say say the trajectory will map + + align:start position:0% +mapping say say the trajectory will map + + + align:start position:0% +mapping say say the trajectory will map +out the trajectory yeah so this will map + + align:start position:0% +out the trajectory yeah so this will map + + + align:start position:0% +out the trajectory yeah so this will map +out the trajectory space time which can + + align:start position:0% +out the trajectory space time which can + + + align:start position:0% +out the trajectory space time which can +be written as a space time coordinate as + + align:start position:0% +be written as a space time coordinate as + + + align:start position:0% +be written as a space time coordinate as +a function of t + + align:start position:0% +a function of t + + + align:start position:0% +a function of t +okay so this par so this parameterize + + align:start position:0% +okay so this par so this parameterize + + + align:start position:0% +okay so this par so this parameterize +the w nine of the + + align:start position:0% +the w nine of the + + + align:start position:0% +the w nine of the +particle so this parameter is the w nine + + align:start position:0% +particle so this parameter is the w nine + + + align:start position:0% +particle so this parameter is the w nine +of the + + align:start position:0% +of the + + + align:start position:0% +of the +particle and + + align:start position:0% +particle and + + + align:start position:0% +particle and +uh to quantize the + + align:start position:0% +uh to quantize the + + + align:start position:0% +uh to quantize the +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +particle the the Quant the particle the + + align:start position:0% +particle the the Quant the particle the + + + align:start position:0% +particle the the Quant the particle the +simplest way is you imagine + + align:start position:0% +simplest way is you imagine + + + align:start position:0% +simplest way is you imagine +just sum over all possible Paths of the + + align:start position:0% +just sum over all possible Paths of the + + + align:start position:0% +just sum over all possible Paths of the +particle so essentially we're doing a + + align:start position:0% +particle so essentially we're doing a + + + align:start position:0% +particle so essentially we're doing a +path + + align:start position:0% + + + + align:start position:0% + +integral essentially you're doing a path + + align:start position:0% +integral essentially you're doing a path + + + align:start position:0% +integral essentially you're doing a path +integral so you you you just integrate + + align:start position:0% +integral so you you you just integrate + + + align:start position:0% +integral so you you you just integrate +of all possible path of a particle and + + align:start position:0% +of all possible path of a particle and + + + align:start position:0% +of all possible path of a particle and +then this essentially a Quantum motion + + align:start position:0% +then this essentially a Quantum motion + + + align:start position:0% +then this essentially a Quantum motion +just Quantum mechanically you can + + align:start position:0% +just Quantum mechanically you can + + + align:start position:0% +just Quantum mechanically you can +fluctuate any way and then this particle + + align:start position:0% +fluctuate any way and then this particle + + + align:start position:0% +fluctuate any way and then this particle +then this + + align:start position:0% +then this + + + align:start position:0% +then this +action for the particle essentially it + + align:start position:0% +action for the particle essentially it + + + align:start position:0% +action for the particle essentially it +just + + align:start position:0% +just + + + align:start position:0% +just +it's the the + + align:start position:0% +it's the the + + + align:start position:0% +it's the the +length so suppose the particle have mass + + align:start position:0% +length so suppose the particle have mass + + + align:start position:0% +length so suppose the particle have mass +m it's just the length of the particle + + align:start position:0% +m it's just the length of the particle + + + align:start position:0% +m it's just the length of the particle +DL along the + + align:start position:0% + + + + align:start position:0% + +trajectory + + align:start position:0% +trajectory + + + align:start position:0% +trajectory +okay and if you include + + align:start position:0% +okay and if you include + + + align:start position:0% +okay and if you include +interactions then you you have to + + align:start position:0% +interactions then you you have to + + + align:start position:0% +interactions then you you have to +include the trajectory with the particle + + align:start position:0% +include the trajectory with the particle + + + align:start position:0% +include the trajectory with the particle +can split say uh say say line can split + + align:start position:0% +can split say uh say say line can split + + + align:start position:0% +can split say uh say say line can split +in two lines Etc so this give you + + align:start position:0% +in two lines Etc so this give you + + + align:start position:0% +in two lines Etc so this give you +interactions + + align:start position:0% + + + + align:start position:0% + +such + + align:start position:0% + + + + align:start position:0% + +okay and this and this you need to add + + align:start position:0% +okay and this and this you need to add + + + align:start position:0% +okay and this and this you need to add +by hand because the particle in + + align:start position:0% +by hand because the particle in + + + align:start position:0% +by hand because the particle in +principle can because you can draw + + align:start position:0% +principle can because you can draw + + + align:start position:0% +principle can because you can draw +infinite ways of particle split into + + align:start position:0% +infinite ways of particle split into + + + align:start position:0% +infinite ways of particle split into +more particles Etc so depend on your + + align:start position:0% +more particles Etc so depend on your + + + align:start position:0% +more particles Etc so depend on your +specific series you need specify say the + + align:start position:0% +specific series you need specify say the + + + align:start position:0% +specific series you need specify say the +interactions so this you need add by + + align:start position:0% +interactions so this you need add by + + + align:start position:0% +interactions so this you need add by +hand + + align:start position:0% + + + + align:start position:0% + +okay so so in principle you can forget + + align:start position:0% +okay so so in principle you can forget + + + align:start position:0% +okay so so in principle you can forget +about the standard formulation of + + align:start position:0% +about the standard formulation of + + + align:start position:0% +about the standard formulation of +quantum field Theory just to to work + + align:start position:0% +quantum field Theory just to to work + + + align:start position:0% +quantum field Theory just to to work +with this particle theory just work with + + align:start position:0% +with this particle theory just work with + + + align:start position:0% +with this particle theory just work with +this particle + + align:start position:0% + + + + align:start position:0% + +theory so the string theory is a + + align:start position:0% +theory so the string theory is a + + + align:start position:0% +theory so the string theory is a +generalization of this uh first quanti + + align:start position:0% + + + + align:start position:0% + +approach so the string the that is + + align:start position:0% +approach so the string the that is + + + align:start position:0% +approach so the string the that is +currently + + align:start position:0% + + + + align:start position:0% + +formulated is formulated in this first + + align:start position:0% +formulated is formulated in this first + + + align:start position:0% +formulated is formulated in this first +quantize + + align:start position:0% + + + + align:start position:0% + +approach so you just + + align:start position:0% + + + + align:start position:0% + +quantize motion of + + align:start position:0% + + + + align:start position:0% + +string in space time + + align:start position:0% + + + + align:start position:0% + +okay so for simp for + + align:start position:0% +okay so for simp for + + + align:start position:0% +okay so for simp for +example so particle case you have a + + align:start position:0% +example so particle case you have a + + + align:start position:0% +example so particle case you have a +point particle string case you have + + align:start position:0% +point particle string case you have + + + align:start position:0% +point particle string case you have +a you have a close noops so imagine we + + align:start position:0% +a you have a close noops so imagine we + + + align:start position:0% +a you have a close noops so imagine we +have a close string okay you have a + + align:start position:0% +have a close string okay you have a + + + align:start position:0% +have a close string okay you have a +close string a string is a one + + align:start position:0% +close string a string is a one + + + align:start position:0% +close string a string is a one +dimensional object so let's consider + + align:start position:0% +dimensional object so let's consider + + + align:start position:0% +dimensional object so let's consider +close string then then the string can be + + align:start position:0% +close string then then the string can be + + + align:start position:0% +close string then then the string can be +parameterized so string itself can be + + align:start position:0% +parameterized so string itself can be + + + align:start position:0% +parameterized so string itself can be +parameterized by parameter Sigma along + + align:start position:0% +parameterized by parameter Sigma along + + + align:start position:0% +parameterized by parameter Sigma along +the along the + + align:start position:0% +the along the + + + align:start position:0% +the along the +string but then then this string can + + align:start position:0% +string but then then this string can + + + align:start position:0% +string but then then this string can +move in the space + + align:start position:0% +move in the space + + + align:start position:0% +move in the space +time then it will Trace out some + + align:start position:0% + + + + align:start position:0% + +trajectory Trace out some + + align:start position:0% +trajectory Trace out some + + + align:start position:0% +trajectory Trace out some +trajectory uh TR some + + align:start position:0% +trajectory uh TR some + + + align:start position:0% +trajectory uh TR some +trajectory um so this give rise to W + + align:start position:0% + + + + align:start position:0% + +sheet so in the particle case you have a + + align:start position:0% +sheet so in the particle case you have a + + + align:start position:0% +sheet so in the particle case you have a +w nine so so in the string case you have + + align:start position:0% +w nine so so in the string case you have + + + align:start position:0% +w nine so so in the string case you have +have a w sheet which we normally called + + align:start position:0% +have a w sheet which we normally called + + + align:start position:0% +have a w sheet which we normally called +Sigma and then the sigma can be again + + align:start position:0% +Sigma and then the sigma can be again + + + align:start position:0% +Sigma and then the sigma can be again +written in terms of the space time + + align:start position:0% +written in terms of the space time + + + align:start position:0% +written in terms of the space time +coordinates as a function of this T and + + align:start position:0% +coordinates as a function of this T and + + + align:start position:0% +coordinates as a function of this T and +sigma okay so now you have two + + align:start position:0% +sigma okay so now you have two + + + align:start position:0% +sigma okay so now you have two +coordinate to parameterize this W + + align:start position:0% +coordinate to parameterize this W + + + align:start position:0% +coordinate to parameterize this W +sheet so this is essentially a two + + align:start position:0% +sheet so this is essentially a two + + + align:start position:0% +sheet so this is essentially a two +dimensional essentially you have two + + align:start position:0% +dimensional essentially you have two + + + align:start position:0% +dimensional essentially you have two +dimensional surface in the space time + + align:start position:0% +dimensional surface in the space time + + + align:start position:0% +dimensional surface in the space time +embedded in space time and and the + + align:start position:0% +embedded in space time and and the + + + align:start position:0% +embedded in space time and and the +string theory just + + align:start position:0% +string theory just + + + align:start position:0% +string theory just +quantize uh it + + align:start position:0% +quantize uh it + + + align:start position:0% +quantize uh it +you just consider the uh the motion of + + align:start position:0% +you just consider the uh the motion of + + + align:start position:0% +you just consider the uh the motion of +all such kind of surfaces yes so in the + + align:start position:0% +all such kind of surfaces yes so in the + + + align:start position:0% +all such kind of surfaces yes so in the +case of a single particle we have a + + align:start position:0% +case of a single particle we have a + + + align:start position:0% +case of a single particle we have a +point does this action actually repr + + align:start position:0% +point does this action actually repr + + + align:start position:0% +point does this action actually repr +like what does it reproduce exactly like + + align:start position:0% +like what does it reproduce exactly like + + + align:start position:0% +like what does it reproduce exactly like +does it is it capable of reproducing all + + align:start position:0% +does it is it capable of reproducing all + + + align:start position:0% +does it is it capable of reproducing all +of quantum field Theory using this pH + + align:start position:0% +of quantum field Theory using this pH + + + align:start position:0% +of quantum field Theory using this pH +yeah in principle but it's not + + align:start position:0% +yeah in principle but it's not + + + align:start position:0% +yeah in principle but it's not +convenient depend on yeah for example if + + align:start position:0% +convenient depend on yeah for example if + + + align:start position:0% +convenient depend on yeah for example if +you have a scaler particle this can + + align:start position:0% +you have a scaler particle this can + + + align:start position:0% +you have a scaler particle this can +certainly uh uh easily reproduce your + + align:start position:0% +certainly uh uh easily reproduce your + + + align:start position:0% +certainly uh uh easily reproduce your +free scaler field the yeah and if you + + align:start position:0% +free scaler field the yeah and if you + + + align:start position:0% +free scaler field the yeah and if you +want to reproduce five cube Theory then + + align:start position:0% +want to reproduce five cube Theory then + + + align:start position:0% +want to reproduce five cube Theory then +you need to add this kind of splitting + + align:start position:0% +you need to add this kind of splitting + + + align:start position:0% +you need to add this kind of splitting +in your when you uh when you do your P + + align:start position:0% +in your when you uh when you do your P + + + align:start position:0% +in your when you uh when you do your P +inte including the trajectories you need + + align:start position:0% +inte including the trajectories you need + + + align:start position:0% +inte including the trajectories you need +to include this kind of trajectories ET + + align:start position:0% +to include this kind of trajectories ET + + + align:start position:0% +to include this kind of trajectories ET +yeah in principle you can do it it's not + + align:start position:0% +yeah in principle you can do it it's not + + + align:start position:0% +yeah in principle you can do it it's not +very convenient I see okay probably + + align:start position:0% +very convenient I see okay probably + + + align:start position:0% +very convenient I see okay probably +interesting yes how do you add + + align:start position:0% +interesting yes how do you add + + + align:start position:0% +interesting yes how do you add +interactions by hand in that par oh well + + align:start position:0% +interactions by hand in that par oh well + + + align:start position:0% +interactions by hand in that par oh well +you just + + align:start position:0% +you just + + + align:start position:0% +you just +require you just in the past integral + + align:start position:0% +require you just in the past integral + + + align:start position:0% +require you just in the past integral +you in the in the yeah here you + + align:start position:0% +you in the in the yeah here you + + + align:start position:0% +you in the in the yeah here you +integrate of all such kind of paths + + align:start position:0% +integrate of all such kind of paths + + + align:start position:0% +integrate of all such kind of paths +right + + align:start position:0% +right + + + align:start position:0% +right +and then you have prescription you say + + align:start position:0% +and then you have prescription you say + + + align:start position:0% +and then you have prescription you say +what kind of pass to + + align:start position:0% +what kind of pass to + + + align:start position:0% +what kind of pass to +include and uh and and and for example + + align:start position:0% +include and uh and and and for example + + + align:start position:0% +include and uh and and and for example +if I have five cube kind of interaction + + align:start position:0% +if I have five cube kind of interaction + + + align:start position:0% +if I have five cube kind of interaction +then you say we should include this kind + + align:start position:0% +then you say we should include this kind + + + align:start position:0% +then you say we should include this kind +of + + align:start position:0% +of + + + align:start position:0% +of +pass by the case it cannot be paramed as + + align:start position:0% +pass by the case it cannot be paramed as + + + align:start position:0% +pass by the case it cannot be paramed as +top because it has the branch yeah yeah + + align:start position:0% +top because it has the branch yeah yeah + + + align:start position:0% +top because it has the branch yeah yeah +then you have to uh uh uh uh uh yeah + + align:start position:0% +then you have to uh uh uh uh uh yeah + + + align:start position:0% +then you have to uh uh uh uh uh yeah +then you yeah then there technical + + align:start position:0% +then you yeah then there technical + + + align:start position:0% +then you yeah then there technical +complications in doing this + + align:start position:0% +complications in doing this + + + align:start position:0% +complications in doing this +Etc so one more question is string + + align:start position:0% +Etc so one more question is string + + + align:start position:0% +Etc so one more question is string +theory formulated in terms of second is + + align:start position:0% +theory formulated in terms of second is + + + align:start position:0% +theory formulated in terms of second is +it possible to formulate in terms of + + align:start position:0% +it possible to formulate in terms of + + + align:start position:0% +it possible to formulate in terms of +second qu + + align:start position:0% +second qu + + + align:start position:0% +second qu +not um not right + + align:start position:0% +not um not right + + + align:start position:0% +not um not right +now so people have people have written + + align:start position:0% +now so people have people have written + + + align:start position:0% +now so people have people have written +down classical stream field Theory and + + align:start position:0% +down classical stream field Theory and + + + align:start position:0% +down classical stream field Theory and +in principle you can quantize it but + + align:start position:0% +in principle you can quantize it but + + + align:start position:0% +in principle you can quantize it but +that's a very complicated thing I think + + align:start position:0% +that's a very complicated thing I think + + + align:start position:0% +that's a very complicated thing I think +nobody have successfully quantized even + + align:start position:0% +nobody have successfully quantized even + + + align:start position:0% +nobody have successfully quantized even +to write down the Ser is very long + + align:start position:0% +to write down the Ser is very long + + + align:start position:0% +to write down the Ser is very long +trivial + + align:start position:0% +trivial + + + align:start position:0% +trivial +okay so so the similar to do conation + + align:start position:0% +okay so so the similar to do conation + + + align:start position:0% +okay so so the similar to do conation +for + + align:start position:0% +for + + + align:start position:0% +for +string you just look at the be you just + + align:start position:0% +string you just look at the be you just + + + align:start position:0% +string you just look at the be you just +consider the pass + + align:start position:0% + + + + align:start position:0% + +integral so in principle to do the + + align:start position:0% +integral so in principle to do the + + + align:start position:0% +integral so in principle to do the +quanti the + + align:start position:0% + + + + align:start position:0% + +string you can again just imagine you + + align:start position:0% +string you can again just imagine you + + + align:start position:0% +string you can again just imagine you +sum over all + + align:start position:0% +sum over all + + + align:start position:0% +sum over all +possible worksheet + + align:start position:0% +possible worksheet + + + align:start position:0% +possible worksheet +configurations or possible this kind of + + align:start position:0% +configurations or possible this kind of + + + align:start position:0% +configurations or possible this kind of +two diens iding of this two dimensional + + align:start position:0% +two diens iding of this two dimensional + + + align:start position:0% +two diens iding of this two dimensional +surface in space time then that + + align:start position:0% +surface in space time then that + + + align:start position:0% +surface in space time then that +essentially uh give rise to all kind of + + align:start position:0% +essentially uh give rise to all kind of + + + align:start position:0% +essentially uh give rise to all kind of +stream motions okay so weighted by some + + align:start position:0% +stream motions okay so weighted by some + + + align:start position:0% +stream motions okay so weighted by some +string + + align:start position:0% + + + + align:start position:0% + +action so the simplest way to write down + + align:start position:0% +action so the simplest way to write down + + + align:start position:0% +action so the simplest way to write down +the string + + align:start position:0% + + + + align:start position:0% + +action it's a straightforward generation + + align:start position:0% +action it's a straightforward generation + + + align:start position:0% +action it's a straightforward generation +of this particle + + align:start position:0% +of this particle + + + align:start position:0% +of this particle +case you say you just integrate over its + + align:start position:0% + + + + align:start position:0% + +area so here is just the length of the + + align:start position:0% +area so here is just the length of the + + + align:start position:0% +area so here is just the length of the +string here is the area but here we also + + align:start position:0% +string here is the area but here we also + + + align:start position:0% +string here is the area but here we also +need to + + align:start position:0% +need to + + + align:start position:0% +need to +include uh so here is the particle Mass + + align:start position:0% +include uh so here is the particle Mass + + + align:start position:0% +include uh so here is the particle Mass +so generation of the particle + + align:start position:0% +so generation of the particle + + + align:start position:0% +so generation of the particle +mass is the say So-Cal string + + align:start position:0% +mass is the say So-Cal string + + + align:start position:0% +mass is the say So-Cal string +tension so T which is normally written + + align:start position:0% +tension so T which is normally written + + + align:start position:0% +tension so T which is normally written +as two alpha Prime so you introduce a + + align:start position:0% +as two alpha Prime so you introduce a + + + align:start position:0% +as two alpha Prime so you introduce a +parameter you introduce a dimensional + + align:start position:0% +parameter you introduce a dimensional + + + align:start position:0% +parameter you introduce a dimensional +parameter Alpha Prime to parameterize + + align:start position:0% +parameter Alpha Prime to parameterize + + + align:start position:0% +parameter Alpha Prime to parameterize +this T and so this is a string tension + + align:start position:0% + + + + align:start position:0% + +so this is mass per + + align:start position:0% +so this is mass per + + + align:start position:0% +so this is mass per +unit Str tension just ma mass per unit + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +okay and and this is normally called the + + align:start position:0% +okay and and this is normally called the + + + align:start position:0% +okay and and this is normally called the +lambug go + + align:start position:0% +lambug go + + + align:start position:0% +lambug go +action so NG so this is lambug goo + + align:start position:0% + + + + align:start position:0% + +action who first wrote it down + + align:start position:0% + + + + align:start position:0% + +okay so this so This the a is + + align:start position:0% +okay so this so This the a is + + + align:start position:0% +okay so this so This the a is +essentially just the area of the surface + + align:start position:0% +essentially just the area of the surface + + + align:start position:0% +essentially just the area of the surface +in the space time okay it just St + + align:start position:0% +in the space time okay it just St + + + align:start position:0% +in the space time okay it just St +generalization of the lens of the + + align:start position:0% + + + + align:start position:0% + +traj and + + align:start position:0% +traj and + + + align:start position:0% +traj and +uh yeah depend on the warries depend on + + align:start position:0% +uh yeah depend on the warries depend on + + + align:start position:0% +uh yeah depend on the warries depend on +what kind of questions you are + + align:start position:0% +what kind of questions you are + + + align:start position:0% +what kind of questions you are +interested then you try to extract those + + align:start position:0% +interested then you try to extract those + + + align:start position:0% +interested then you try to extract those +kind of physical answers from this this + + align:start position:0% +kind of physical answers from this this + + + align:start position:0% +kind of physical answers from this this +path integral okay any questions so far + + align:start position:0% +path integral okay any questions so far + + + align:start position:0% +path integral okay any questions so far +yes do we allow paths that contract a + + align:start position:0% +yes do we allow paths that contract a + + + align:start position:0% +yes do we allow paths that contract a +string to a point yeah yeah I will show + + align:start position:0% +string to a point yeah yeah I will show + + + align:start position:0% +string to a point yeah yeah I will show +you + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yeah two time + + align:start position:0% +yeah two time + + + align:start position:0% +yeah two time +variable no single no Sigma + + align:start position:0% +variable no single no Sigma + + + align:start position:0% +variable no single no Sigma +parameterize the string itself and the + + align:start position:0% +parameterize the string itself and the + + + align:start position:0% +parameterize the string itself and the +tow is parameterize the motion of the + + align:start position:0% +tow is parameterize the motion of the + + + align:start position:0% +tow is parameterize the motion of the +string along the uh the motion of the + + align:start position:0% +string along the uh the motion of the + + + align:start position:0% +string along the uh the motion of the +string but this the there is a Time + + align:start position:0% +string but this the there is a Time + + + align:start position:0% +string but this the there is a Time +variable in Sigma and or it's just a no + + align:start position:0% +variable in Sigma and or it's just a no + + + align:start position:0% +variable in Sigma and or it's just a no +no T is the time yeah t is the internal + + align:start position:0% +no T is the time yeah t is the internal + + + align:start position:0% +no T is the time yeah t is the internal +time for the string okay and then + + align:start position:0% +time for the string okay and then + + + align:start position:0% +time for the string okay and then +there's a time in the in here in the X + + align:start position:0% +there's a time in the in here in the X + + + align:start position:0% +there's a time in the in here in the X +zero in the space time okay so this can + + align:start position:0% +zero in the space time okay so this can + + + align:start position:0% +zero in the space time okay so this can +be considered some kind of a proper time + + align:start position:0% +be considered some kind of a proper time + + + align:start position:0% +be considered some kind of a proper time +for the string internal time for the + + align:start position:0% +for the string internal time for the + + + align:start position:0% +for the string internal time for the +string yeah just like the you + + align:start position:0% +string yeah just like the you + + + align:start position:0% +string yeah just like the you +parameterize the trajectory of the + + align:start position:0% +parameterize the trajectory of the + + + align:start position:0% +parameterize the trajectory of the +particle uh uh you have some to to + + align:start position:0% +particle uh uh you have some to to + + + align:start position:0% +particle uh uh you have some to to +parameterize the trajectory particle + + align:start position:0% +parameterize the trajectory particle + + + align:start position:0% +parameterize the trajectory particle +this the same thing but I mean for any + + align:start position:0% +this the same thing but I mean for any + + + align:start position:0% +this the same thing but I mean for any +proper time it isn't there is or itself + + align:start position:0% +proper time it isn't there is or itself + + + align:start position:0% +proper time it isn't there is or itself +is a four dimensional space time why + + align:start position:0% +is a four dimensional space time why + + + align:start position:0% +is a four dimensional space time why +there's only like one parameter of to + + align:start position:0% +there's only like one parameter of to + + + align:start position:0% +there's only like one parameter of to +which does not have this uh four + + align:start position:0% +which does not have this uh four + + + align:start position:0% +which does not have this uh four +component no I don't understand what you + + align:start position:0% +component no I don't understand what you + + + align:start position:0% +component no I don't understand what you +no this only a single time you have a + + align:start position:0% +no this only a single time you have a + + + align:start position:0% +no this only a single time you have a +particle you have only single time right + + align:start position:0% +particle you have only single time right + + + align:start position:0% +particle you have only single time right +no do you agree here there's only tow + + align:start position:0% +no do you agree here there's only tow + + + align:start position:0% +no do you agree here there's only tow +here + + align:start position:0% +here + + + align:start position:0% +here +no here I have just have a line I + + align:start position:0% +no here I have just have a line I + + + align:start position:0% +no here I have just have a line I +parameterize this nine I call it tow oh + + align:start position:0% +parameterize this nine I call it tow oh + + + align:start position:0% +parameterize this nine I call it tow oh +okay yes here I have a two dimensional + + align:start position:0% +okay yes here I have a two dimensional + + + align:start position:0% +okay yes here I have a two dimensional +here I have a string and then each point + + align:start position:0% +here I have a string and then each point + + + align:start position:0% +here I have a string and then each point +on the string moves like a particle and + + align:start position:0% +on the string moves like a particle and + + + align:start position:0% +on the string moves like a particle and +then I parametrize by a tow okay it it's + + align:start position:0% +then I parametrize by a tow okay it it's + + + align:start position:0% +then I parametrize by a tow okay it it's +the same thing that's much Clear + + align:start position:0% +the same thing that's much Clear + + + align:start position:0% +the same thing that's much Clear +yeah + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +you what's the metric on the world cheap + + align:start position:0% +you what's the metric on the world cheap + + + align:start position:0% +you what's the metric on the world cheap +does that make sense to us is it like + + align:start position:0% +does that make sense to us is it like + + + align:start position:0% +does that make sense to us is it like +minus plus or of course it makes sense + + align:start position:0% +minus plus or of course it makes sense + + + align:start position:0% +minus plus or of course it makes sense +uh uh uh uh of course on the war sheet + + align:start position:0% +uh uh uh uh of course on the war sheet + + + align:start position:0% +uh uh uh uh of course on the war sheet +should be low ranging oh uh uh whatever + + align:start position:0% +should be low ranging oh uh uh whatever + + + align:start position:0% +should be low ranging oh uh uh whatever +is the uh metric on the uh War sheet is + + align:start position:0% +is the uh metric on the uh War sheet is + + + align:start position:0% +is the uh metric on the uh War sheet is +the uh will be induced from the space + + align:start position:0% +the uh will be induced from the space + + + align:start position:0% +the uh will be induced from the space +time okay so so it would be a minus plus + + align:start position:0% +time okay so so it would be a minus plus + + + align:start position:0% +time okay so so it would be a minus plus +yeah for example yeah yeah it's low + + align:start position:0% +yeah for example yeah yeah it's low + + + align:start position:0% +yeah for example yeah yeah it's low +ranging yeah yeah you can also yeah we + + align:start position:0% +ranging yeah yeah you can also yeah we + + + align:start position:0% +ranging yeah yeah you can also yeah we +can talk yes so one other question so if + + align:start position:0% +can talk yes so one other question so if + + + align:start position:0% +can talk yes so one other question so if +that should be interpreted as proper + + align:start position:0% +that should be interpreted as proper + + + align:start position:0% +that should be interpreted as proper +time if I have a string which is moving + + align:start position:0% +time if I have a string which is moving + + + align:start position:0% +time if I have a string which is moving +in some weird non-uniform way how does + + align:start position:0% +in some weird non-uniform way how does + + + align:start position:0% +in some weird non-uniform way how does +it make sense to talk about the proper + + align:start position:0% +it make sense to talk about the proper + + + align:start position:0% +it make sense to talk about the proper +time of the string when like you can + + align:start position:0% +time of the string when like you can + + + align:start position:0% +time of the string when like you can +imagine the different points on the + + align:start position:0% +imagine the different points on the + + + align:start position:0% +imagine the different points on the +string yeah yeah yeah good point so so + + align:start position:0% +string yeah yeah yeah good point so so + + + align:start position:0% +string yeah yeah yeah good point so so +often you cannot talk about that uh uh + + align:start position:0% +often you cannot talk about that uh uh + + + align:start position:0% +often you cannot talk about that uh uh +and and and this just give you aoristic + + align:start position:0% +and and and this just give you aoristic + + + align:start position:0% +and and and this just give you aoristic +picture because the in principle string + + align:start position:0% +picture because the in principle string + + + align:start position:0% +picture because the in principle string +can can do highly long classical motion + + align:start position:0% +can can do highly long classical motion + + + align:start position:0% +can can do highly long classical motion +and then that is encoded say in + + align:start position:0% +and then that is encoded say in + + + align:start position:0% +and then that is encoded say in +integrating over all such kind of + + align:start position:0% +integrating over all such kind of + + + align:start position:0% +integrating over all such kind of +surfaces okay and and some of them you + + align:start position:0% +surfaces okay and and some of them you + + + align:start position:0% +surfaces okay and and some of them you +cannot interpret it classically or semi + + align:start position:0% +cannot interpret it classically or semi + + + align:start position:0% +cannot interpret it classically or semi +classically into this kind of picture + + align:start position:0% +classically into this kind of picture + + + align:start position:0% +classically into this kind of picture +you visualize it so so I will draw some + + align:start position:0% +you visualize it so so I will draw some + + + align:start position:0% +you visualize it so so I will draw some +pictures later you will see yeah yes um + + align:start position:0% +pictures later you will see yeah yes um + + + align:start position:0% +pictures later you will see yeah yes um +might question like without a good + + align:start position:0% +might question like without a good + + + align:start position:0% +might question like without a good +answer but uh what is the I guess why + + align:start position:0% +answer but uh what is the I guess why + + + align:start position:0% +answer but uh what is the I guess why +does the action take that form what is + + align:start position:0% +does the action take that form what is + + + align:start position:0% +does the action take that form what is +that accomplishing physically or like I + + align:start position:0% +that accomplishing physically or like I + + + align:start position:0% +that accomplishing physically or like I +guess maybe an easier example would be + + align:start position:0% +guess maybe an easier example would be + + + align:start position:0% +guess maybe an easier example would be +um up there on the first bation approach + + align:start position:0% +um up there on the first bation approach + + + align:start position:0% +um up there on the first bation approach +how does that reproduce Q up um you say + + align:start position:0% +how does that reproduce Q up um you say + + + align:start position:0% +how does that reproduce Q up um you say +why that reproduce QT yeah how how that + + align:start position:0% +why that reproduce QT yeah how how that + + + align:start position:0% +why that reproduce QT yeah how how that +reproduce QT of course it's a technical + + align:start position:0% +reproduce QT of course it's a technical + + + align:start position:0% +reproduce QT of course it's a technical +question uh um which you have to + + align:start position:0% +question uh um which you have to + + + align:start position:0% +question uh um which you have to +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +explicitly and uh but the question is + + align:start position:0% +explicitly and uh but the question is + + + align:start position:0% +explicitly and uh but the question is +that why do we choose that uh the reason + + align:start position:0% +that why do we choose that uh the reason + + + align:start position:0% +that why do we choose that uh the reason +we choose that is the it's based on war + + align:start position:0% +we choose that is the it's based on war + + + align:start position:0% +we choose that is the it's based on war +is principles so first uh uh uh uh uh + + align:start position:0% +is principles so first uh uh uh uh uh + + + align:start position:0% +is principles so first uh uh uh uh uh +first that thing whatever it is should + + align:start position:0% +first that thing whatever it is should + + + align:start position:0% +first that thing whatever it is should +not deter should not depend on how you + + align:start position:0% +not deter should not depend on how you + + + align:start position:0% +not deter should not depend on how you +choose this + + align:start position:0% +choose this + + + align:start position:0% +choose this +to because you can parameterize your + + align:start position:0% +to because you can parameterize your + + + align:start position:0% +to because you can parameterize your +trajectory anywhere you want so that the + + align:start position:0% +trajectory anywhere you want so that the + + + align:start position:0% +trajectory anywhere you want so that the +L so whatever this action should not + + align:start position:0% +L so whatever this action should not + + + align:start position:0% +L so whatever this action should not +depend on the parametrization and also + + align:start position:0% +depend on the parametrization and also + + + align:start position:0% +depend on the parametrization and also +uh this action should be + + align:start position:0% +uh this action should be + + + align:start position:0% +uh this action should be +Len in warant on the space and the lence + + align:start position:0% +Len in warant on the space and the lence + + + align:start position:0% +Len in warant on the space and the lence +Boost should be translation warant ETA + + align:start position:0% +Boost should be translation warant ETA + + + align:start position:0% +Boost should be translation warant ETA +and with those conditions then + + align:start position:0% +and with those conditions then + + + align:start position:0% +and with those conditions then +essentially uh uh uh essentially + + align:start position:0% +essentially uh uh uh essentially + + + align:start position:0% +essentially uh uh uh essentially +uniquely determined to be this form yeah + + align:start position:0% +uniquely determined to be this form yeah + + + align:start position:0% +uniquely determined to be this form yeah +essentially unique determined to this + + align:start position:0% +essentially unique determined to this + + + align:start position:0% +essentially unique determined to this +form yes so I guess if you were doing a + + align:start position:0% +form yes so I guess if you were doing a + + + align:start position:0% +form yes so I guess if you were doing a +quantization of the bosonic string like + + align:start position:0% +quantization of the bosonic string like + + + align:start position:0% +quantization of the bosonic string like +if you were deriving the field equations + + align:start position:0% +if you were deriving the field equations + + + align:start position:0% +if you were deriving the field equations +would you use nambo or would you use po + + align:start position:0% +would you use nambo or would you use po + + + align:start position:0% +would you use nambo or would you use po +yeah yeah that's right if you really + + align:start position:0% +yeah yeah that's right if you really + + + align:start position:0% +yeah yeah that's right if you really +quantize you actually don't use + + align:start position:0% +quantize you actually don't use + + + align:start position:0% +quantize you actually don't use +lambot lambot use it for the + + align:start position:0% +lambot lambot use it for the + + + align:start position:0% +lambot lambot use it for the +classical description yeah I did not + + align:start position:0% +classical description yeah I did not + + + align:start position:0% +classical description yeah I did not +mention the other other forms it's just + + align:start position:0% +mention the other other forms it's just + + + align:start position:0% +mention the other other forms it's just +for our prop current discussion is not + + align:start position:0% +for our prop current discussion is not + + + align:start position:0% +for our prop current discussion is not +essential yeah yeah indeed when you + + align:start position:0% +essential yeah yeah indeed when you + + + align:start position:0% +essential yeah yeah indeed when you +quantize you actually use a different + + align:start position:0% +quantize you actually use a different + + + align:start position:0% +quantize you actually use a different +form of this + + align:start position:0% + + + + align:start position:0% + +action any other + + align:start position:0% +action any other + + + align:start position:0% +action any other +questions + + align:start position:0% +questions + + + align:start position:0% +questions +good so + + align:start position:0% + + + + align:start position:0% + +now for + + align:start position:0% +now for + + + align:start position:0% +now for +example yeah + + align:start position:0% +example yeah + + + align:start position:0% +example yeah +so say how you uh + + align:start position:0% +so say how you uh + + + align:start position:0% +so say how you uh +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um so depend on what kind of questions + + align:start position:0% +um so depend on what kind of questions + + + align:start position:0% +um so depend on what kind of questions +you are interested and uh and you you + + align:start position:0% +you are interested and uh and you you + + + align:start position:0% +you are interested and uh and you you +try to extract try to extract them say + + align:start position:0% +try to extract try to extract them say + + + align:start position:0% +try to extract try to extract them say +from this kind of path integral and of + + align:start position:0% +from this kind of path integral and of + + + align:start position:0% +from this kind of path integral and of +course this is a highly non-trivial + + align:start position:0% +course this is a highly non-trivial + + + align:start position:0% +course this is a highly non-trivial +questions and require say some kind of + + align:start position:0% +questions and require say some kind of + + + align:start position:0% +questions and require say some kind of +TR and arrrow Etc so let me just uh tell + + align:start position:0% +TR and arrrow Etc so let me just uh tell + + + align:start position:0% +TR and arrrow Etc so let me just uh tell +you um say if I have a say say if I want + + align:start position:0% +you um say if I have a say say if I want + + + align:start position:0% +you um say if I have a say say if I want +to calculate the vacuum process so if I + + align:start position:0% +to calculate the vacuum process so if I + + + align:start position:0% +to calculate the vacuum process so if I +want to calc the vacuum + + align:start position:0% + + + + align:start position:0% + +energy okay so so let me call this this + + align:start position:0% +energy okay so so let me call this this + + + align:start position:0% +energy okay so so let me call this this +string so if I uh so remember when we + + align:start position:0% +string so if I uh so remember when we + + + align:start position:0% +string so if I uh so remember when we +talk about lar engage series and if you + + align:start position:0% +talk about lar engage series and if you + + + align:start position:0% +talk about lar engage series and if you +want to calculate the vacuum energy then + + align:start position:0% +want to calculate the vacuum energy then + + + align:start position:0% +want to calculate the vacuum energy then +you calculate the you sum of all POS + + align:start position:0% +you calculate the you sum of all POS + + + align:start position:0% +you calculate the you sum of all POS +vacuum diagrams Etc okay you sum of all + + align:start position:0% +vacuum diagrams Etc okay you sum of all + + + align:start position:0% +vacuum diagrams Etc okay you sum of all +possible vacuum diagrams and but suppose + + align:start position:0% +possible vacuum diagrams and but suppose + + + align:start position:0% +possible vacuum diagrams and but suppose +we we want to calculate the vacuum + + align:start position:0% +we we want to calculate the vacuum + + + align:start position:0% +we we want to calculate the vacuum +energy in the stren series + + align:start position:0% +energy in the stren series + + + align:start position:0% +energy in the stren series +and then you do the similar thing you + + align:start position:0% +and then you do the similar thing you + + + align:start position:0% +and then you do the similar thing you +you just do the what do you want to do + + align:start position:0% +you just do the what do you want to do + + + align:start position:0% +you just do the what do you want to do +for the string you say you sum + + align:start position:0% + + + + align:start position:0% + +over or + + align:start position:0% + + + + align:start position:0% + +Clos 2D + + align:start position:0% + + + + align:start position:0% + +surfaces okay so the closed here is + + align:start position:0% +surfaces okay so the closed here is + + + align:start position:0% +surfaces okay so the closed here is +essential so this is based on the + + align:start position:0% +essential so this is based on the + + + align:start position:0% +essential so this is based on the +intuition that when we in the quantum + + align:start position:0% +intuition that when we in the quantum + + + align:start position:0% +intuition that when we in the quantum +vity when you sum over F diagrams and + + align:start position:0% +vity when you sum over F diagrams and + + + align:start position:0% +vity when you sum over F diagrams and +the F diagrams H recity can be + + align:start position:0% +the F diagrams H recity can be + + + align:start position:0% +the F diagrams H recity can be +considered as a particle trajectories + + align:start position:0% +considered as a particle trajectories + + + align:start position:0% +considered as a particle trajectories +Etc and for the vacuum + + align:start position:0% +Etc and for the vacuum + + + align:start position:0% +Etc and for the vacuum +process the none + + align:start position:0% +process the none + + + align:start position:0% +process the none +of there's no exteral LS so so + + align:start position:0% +of there's no exteral LS so so + + + align:start position:0% +of there's no exteral LS so so +everything coming out of the vacuum then + + align:start position:0% +everything coming out of the vacuum then + + + align:start position:0% +everything coming out of the vacuum then +come back to the vacuum so that's why so + + align:start position:0% +come back to the vacuum so that's why so + + + align:start position:0% +come back to the vacuum so that's why so +if we want to calculate the vacuum + + align:start position:0% +if we want to calculate the vacuum + + + align:start position:0% +if we want to calculate the vacuum +energy the string the and again should + + align:start position:0% +energy the string the and again should + + + align:start position:0% +energy the string the and again should +corresponding to the virtual stream + + align:start position:0% +corresponding to the virtual stream + + + align:start position:0% +corresponding to the virtual stream +motion and again the virtual stream + + align:start position:0% +motion and again the virtual stream + + + align:start position:0% +motion and again the virtual stream +motion should correspond to sum of all + + align:start position:0% +motion should correspond to sum of all + + + align:start position:0% +motion should correspond to sum of all +such kind of surfaces without any + + align:start position:0% +such kind of surfaces without any + + + align:start position:0% +such kind of surfaces without any +external lags uh so so should be closed + + align:start position:0% +external lags uh so so should be closed + + + align:start position:0% +external lags uh so so should be closed +surfaces okay to be close surface so as + + align:start position:0% +surfaces okay to be close surface so as + + + align:start position:0% +surfaces okay to be close surface so as +analog of the particle case and uh so as + + align:start position:0% +analog of the particle case and uh so as + + + align:start position:0% +analog of the particle case and uh so as +exactly as in the quantum fi case it's + + align:start position:0% +exactly as in the quantum fi case it's + + + align:start position:0% +exactly as in the quantum fi case it's +easier to do this using the uking by + + align:start position:0% +easier to do this using the uking by + + + align:start position:0% +easier to do this using the uking by +going to the uking + + align:start position:0% +going to the uking + + + align:start position:0% +going to the uking +signature and say say go to the uking + + align:start position:0% +signature and say say go to the uking + + + align:start position:0% +signature and say say go to the uking +signature they're going to in + + align:start position:0% +signature they're going to in + + + align:start position:0% +signature they're going to in +signature so essentially analytic so + + align:start position:0% +signature so essentially analytic so + + + align:start position:0% +signature so essentially analytic so +instead of considering a surface in the + + align:start position:0% +instead of considering a surface in the + + + align:start position:0% +instead of considering a surface in the +low range space time you consider you + + align:start position:0% +low range space time you consider you + + + align:start position:0% +low range space time you consider you +need continue your space time the full + + align:start position:0% +need continue your space time the full + + + align:start position:0% +need continue your space time the full +space time to the to theing signature + + align:start position:0% +space time to the to theing signature + + + align:start position:0% +space time to the to theing signature +and then and then and then this just + + align:start position:0% +and then and then and then this just + + + align:start position:0% +and then and then and then this just +become some surface in some ukian space + + align:start position:0% +become some surface in some ukian space + + + align:start position:0% +become some surface in some ukian space +and then this is just much easier + + align:start position:0% +and then this is just much easier + + + align:start position:0% +and then this is just much easier +mathematical object to deal with okay so + + align:start position:0% +mathematical object to deal with okay so + + + align:start position:0% +mathematical object to deal with okay so +that's what you get and if you have a + + align:start position:0% +that's what you get and if you have a + + + align:start position:0% +that's what you get and if you have a +string and then you have this + + align:start position:0% +string and then you have this + + + align:start position:0% +string and then you have this +okay okay so now when you sum over all + + align:start position:0% +okay okay so now when you sum over all + + + align:start position:0% +okay okay so now when you sum over all +surfaces now you have a choice first you + + align:start position:0% +surfaces now you have a choice first you + + + align:start position:0% +surfaces now you have a choice first you +can sum over the + + align:start position:0% +can sum over the + + + align:start position:0% +can sum over the +topology so we talked about before all + + align:start position:0% +topology so we talked about before all + + + align:start position:0% +topology so we talked about before all +two dimensional surfaces topology is + + align:start position:0% +two dimensional surfaces topology is + + + align:start position:0% +two dimensional surfaces topology is +classified by this + + align:start position:0% +classified by this + + + align:start position:0% +classified by this +genus and then you can sum + + align:start position:0% +genus and then you can sum + + + align:start position:0% +genus and then you can sum +over surfaces with a given uh so you can + + align:start position:0% +over surfaces with a given uh so you can + + + align:start position:0% +over surfaces with a given uh so you can +separate the sum into sum over + + align:start position:0% +separate the sum into sum over + + + align:start position:0% +separate the sum into sum over +topology and uh and then some Services + + align:start position:0% +topology and uh and then some Services + + + align:start position:0% +topology and uh and then some Services +of each of uh a given + + align:start position:0% +of each of uh a given + + + align:start position:0% +of each of uh a given +topology given H okay so this H is the + + align:start position:0% +topology given H okay so this H is the + + + align:start position:0% +topology given H okay so this H is the +genus so essentially we just summing of + + align:start position:0% +genus so essentially we just summing of + + + align:start position:0% +genus so essentially we just summing of +all possible two dimensional closed + + align:start position:0% +all possible two dimensional closed + + + align:start position:0% +all possible two dimensional closed +surfaces + + align:start position:0% +surfaces + + + align:start position:0% +surfaces +okay is this point clear this is Absolut + + align:start position:0% +okay is this point clear this is Absolut + + + align:start position:0% +okay is this point clear this is Absolut +key + + align:start position:0% + + + + align:start position:0% + +point and uh and with this minus S and + + align:start position:0% + + + + align:start position:0% + +G okay + + align:start position:0% + + + + align:start position:0% + +so now there's a very important + + align:start position:0% +so now there's a very important + + + align:start position:0% +so now there's a very important +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +trick and uh and this mathematical trick + + align:start position:0% +trick and uh and this mathematical trick + + + align:start position:0% +trick and uh and this mathematical trick +will + + align:start position:0% +will + + + align:start position:0% +will +um it can be justified rigorously but I + + align:start position:0% +um it can be justified rigorously but I + + + align:start position:0% +um it can be justified rigorously but I +will not just put it + + align:start position:0% +will not just put it + + + align:start position:0% +will not just put it +here I will just add it here it said now + + align:start position:0% +here I will just add it here it said now + + + align:start position:0% +here I will just add it here it said now +just in physics whenever you see a + + align:start position:0% +just in physics whenever you see a + + + align:start position:0% +just in physics whenever you see a +discrete sum like this what do you + + align:start position:0% +discrete sum like this what do you + + + align:start position:0% +discrete sum like this what do you +do or in mathematics whenever you see a + + align:start position:0% +do or in mathematics whenever you see a + + + align:start position:0% +do or in mathematics whenever you see a +discrete sum like this what do you do + + align:start position:0% + + + + align:start position:0% + +H + + align:start position:0% + + + + align:start position:0% + +sorry lar + + align:start position:0% +sorry lar + + + align:start position:0% +sorry lar +terms exactly you add the + + align:start position:0% +terms exactly you add the + + + align:start position:0% +terms exactly you add the +weight so here I will add a weight here + + align:start position:0% +weight so here I will add a weight here + + + align:start position:0% +weight so here I will add a weight here +so so here I'm summing over a + + align:start position:0% +so so here I'm summing over a + + + align:start position:0% +so so here I'm summing over a +topology but I have but in but then I + + align:start position:0% +topology but I have but in but then I + + + align:start position:0% +topology but I have but in but then I +but now I will add by hand a weight to + + align:start position:0% +but now I will add by hand a weight to + + + align:start position:0% +but now I will add by hand a weight to +weight different topology so Lambda just + + align:start position:0% +weight different topology so Lambda just + + + align:start position:0% +weight different topology so Lambda just +some parameter + + align:start position:0% +some parameter + + + align:start position:0% +some parameter +so Lambda this parameter I introduced by + + align:start position:0% +so Lambda this parameter I introduced by + + + align:start position:0% +so Lambda this parameter I introduced by +now uh by hand + + align:start position:0% + + + + align:start position:0% + +myself okay so this is just the + + align:start position:0% + + + + align:start position:0% + +weight for different topology + + align:start position:0% + + + + align:start position:0% + +so Kai is the oil Lumber so Lambda just + + align:start position:0% +so Kai is the oil Lumber so Lambda just + + + align:start position:0% +so Kai is the oil Lumber so Lambda just +some uh so Kai is the oil number 2us 2 + + align:start position:0% +some uh so Kai is the oil number 2us 2 + + + align:start position:0% +some uh so Kai is the oil number 2us 2 +H and the + + align:start position:0% +H and the + + + align:start position:0% +H and the +Lambda just can be consider as some kind + + align:start position:0% +Lambda just can be consider as some kind + + + align:start position:0% +Lambda just can be consider as some kind +of chemical + + align:start position:0% + + + + align:start position:0% + +potential some kind of chemical + + align:start position:0% +potential some kind of chemical + + + align:start position:0% +potential some kind of chemical +potential say for for topology + + align:start position:0% + + + + align:start position:0% + +okay yeah yeah just like uh in the + + align:start position:0% +okay yeah yeah just like uh in the + + + align:start position:0% +okay yeah yeah just like uh in the +system say you have a conserved charge + + align:start position:0% +system say you have a conserved charge + + + align:start position:0% +system say you have a conserved charge +then you then it's when you add + + align:start position:0% +then you then it's when you add + + + align:start position:0% +then you then it's when you add +particles different particle number it's + + align:start position:0% +particles different particle number it's + + + align:start position:0% +particles different particle number it's +convenient to add chemical potential so + + align:start position:0% +convenient to add chemical potential so + + + align:start position:0% +convenient to add chemical potential so +Lambda is like + + align:start position:0% + + + + align:start position:0% + +that so so even though I added by hand + + align:start position:0% +that so so even though I added by hand + + + align:start position:0% +that so so even though I added by hand +now even though I added by hand here but + + align:start position:0% +now even though I added by hand here but + + + align:start position:0% +now even though I added by hand here but +in stren actually this + + align:start position:0% +in stren actually this + + + align:start position:0% +in stren actually this +is arise completely natural from the + + align:start position:0% +is arise completely natural from the + + + align:start position:0% +is arise completely natural from the +stren the uh uh there's a rigorous way + + align:start position:0% +stren the uh uh there's a rigorous way + + + align:start position:0% +stren the uh uh there's a rigorous way +one can show how that arises but I will + + align:start position:0% +one can show how that arises but I will + + + align:start position:0% +one can show how that arises but I will +not do it here it's not important for + + align:start position:0% +not do it here it's not important for + + + align:start position:0% +not do it here it's not important for +our + + align:start position:0% +our + + + align:start position:0% +our +purpose and I will also introduce a + + align:start position:0% +purpose and I will also introduce a + + + align:start position:0% +purpose and I will also introduce a +rotation say GS is equal to exponential + + align:start position:0% +rotation say GS is equal to exponential + + + align:start position:0% +rotation say GS is equal to exponential +Lambda + + align:start position:0% + + + + align:start position:0% + +okay so now let's look at this Pro uh uh + + align:start position:0% +okay so now let's look at this Pro uh uh + + + align:start position:0% +okay so now let's look at this Pro uh uh +now let's look at this + + align:start position:0% +now let's look at this + + + align:start position:0% +now let's look at this +summation so here you sum + + align:start position:0% + + + + align:start position:0% + +over + + align:start position:0% +over + + + align:start position:0% +over +so at H equal to zero you Sum of All + + align:start position:0% +so at H equal to zero you Sum of All + + + align:start position:0% +so at H equal to zero you Sum of All +Surface with the topology of a + + align:start position:0% +Surface with the topology of a + + + align:start position:0% +Surface with the topology of a +sphere and the weight is given by GS + + align:start position:0% +sphere and the weight is given by GS + + + align:start position:0% +sphere and the weight is given by GS +minus 2 which is exponential minus 2 + + align:start position:0% +minus 2 which is exponential minus 2 + + + align:start position:0% +minus 2 which is exponential minus 2 +Lambda okay yeah because the kai when H + + align:start position:0% +Lambda okay yeah because the kai when H + + + align:start position:0% +Lambda okay yeah because the kai when H +equal to Zer Kai = to 2 so this is + + align:start position:0% +equal to Zer Kai = to 2 so this is + + + align:start position:0% +equal to Zer Kai = to 2 so this is +Justus 2 Lambda + + align:start position:0% +Justus 2 Lambda + + + align:start position:0% +Justus 2 Lambda +and uh and so this is one / GS squ okay + + align:start position:0% +and uh and so this is one / GS squ okay + + + align:start position:0% +and uh and so this is one / GS squ okay +and then the then the + + align:start position:0% + + + + align:start position:0% + +Taurus this H equal to 1 so this is just + + align:start position:0% +Taurus this H equal to 1 so this is just + + + align:start position:0% +Taurus this H equal to 1 so this is just +the GS to the power + + align:start position:0% +the GS to the power + + + align:start position:0% +the GS to the power +zero it's order + + align:start position:0% +zero it's order + + + align:start position:0% +zero it's order +one if you have Genus + + align:start position:0% + + + + align:start position:0% + +2 so this would be g h = to 2 then will + + align:start position:0% +2 so this would be g h = to 2 then will + + + align:start position:0% +2 so this would be g h = to 2 then will +be GS s + + align:start position:0% + + + + align:start position:0% + +okay so here is remarkable + + align:start position:0% + + + + align:start position:0% + +fact so here is a remarkable + + align:start position:0% + + + + align:start position:0% + +fact here's a remarkable fact + + align:start position:0% + + + + align:start position:0% + +you said some + + align:start position:0% + + + + align:start position:0% + +over + + align:start position:0% + + + + align:start position:0% + +topology + + align:start position:0% + + + + align:start position:0% + +automatically + + align:start position:0% +automatically + + + align:start position:0% +automatically +automatically includes + + align:start position:0% + + + + align:start position:0% + +interaction of + + align:start position:0% + + + + align:start position:0% + +strings + + align:start position:0% +strings + + + align:start position:0% +strings +okay in + + align:start position:0% + + + + align:start position:0% + +fact this fo is + + align:start position:0% + + + + align:start position:0% + +specifies string interactions + + align:start position:0% + + + + align:start position:0% + +okay so let me just uh elaborate on this + + align:start position:0% + + + + align:start position:0% + +statement so so we can see this + + align:start position:0% +statement so so we can see this + + + align:start position:0% +statement so so we can see this +statement from these pmms here okay so + + align:start position:0% +statement from these pmms here okay so + + + align:start position:0% +statement from these pmms here okay so +now let's look at the physical meaning + + align:start position:0% +now let's look at the physical meaning + + + align:start position:0% +now let's look at the physical meaning +of those + + align:start position:0% +of those + + + align:start position:0% +of those +diagrams so let's first look at the + + align:start position:0% +diagrams so let's first look at the + + + align:start position:0% +diagrams so let's first look at the +sphere diagrams + + align:start position:0% + + + + align:start position:0% + +so this supposed to be draw a + + align:start position:0% + + + + align:start position:0% + +sphere + + align:start position:0% +sphere + + + align:start position:0% +sphere +okay so what I'm describing to is + + align:start position:0% +okay so what I'm describing to is + + + align:start position:0% +okay so what I'm describing to is +puristic from physical perspective from + + align:start position:0% +puristic from physical perspective from + + + align:start position:0% +puristic from physical perspective from +from physical perspective so if you + + align:start position:0% +from physical perspective so if you + + + align:start position:0% +from physical perspective so if you +think about sphere embedded in the + + align:start position:0% +think about sphere embedded in the + + + align:start position:0% +think about sphere embedded in the +space so this is + + align:start position:0% +space so this is + + + align:start position:0% +space so this is +like so if you think from say imagine + + align:start position:0% +like so if you think from say imagine + + + align:start position:0% +like so if you think from say imagine +your time going up okay imagine your + + align:start position:0% +your time going up okay imagine your + + + align:start position:0% +your time going up okay imagine your +time going up so this next you nucleate + + align:start position:0% +time going up so this next you nucleate + + + align:start position:0% +time going up so this next you nucleate +a infini tmal string at the tip of the + + align:start position:0% +a infini tmal string at the tip of the + + + align:start position:0% +a infini tmal string at the tip of the +sphere and then then this stram + + align:start position:0% +sphere and then then this stram + + + align:start position:0% +sphere and then then this stram +propagate at each time you have a string + + align:start position:0% +propagate at each time you have a string + + + align:start position:0% +propagate at each time you have a string +and then at some future time then uh + + align:start position:0% +and then at some future time then uh + + + align:start position:0% +and then at some future time then uh +then then go back to the vacuum okay and + + align:start position:0% +then then go back to the vacuum okay and + + + align:start position:0% +then then go back to the vacuum okay and +so you just have a string come in and + + align:start position:0% +so you just have a string come in and + + + align:start position:0% +so you just have a string come in and +come out a string come out from the + + align:start position:0% +come out a string come out from the + + + align:start position:0% +come out a string come out from the +vacuum and then go back and the sphere + + align:start position:0% +vacuum and then go back and the sphere + + + align:start position:0% +vacuum and then go back and the sphere +just describe this kind of virtual + + align:start position:0% +just describe this kind of virtual + + + align:start position:0% +just describe this kind of virtual +process say so you you nucleate string + + align:start position:0% +process say so you you nucleate string + + + align:start position:0% +process say so you you nucleate string +and then uh uh then light then disappear + + align:start position:0% +and then uh uh then light then disappear + + + align:start position:0% +and then uh uh then light then disappear +again + + align:start position:0% +again + + + align:start position:0% +again +okay say nucleate + + align:start position:0% + + + + align:start position:0% + +string string + + align:start position:0% +string string + + + align:start position:0% +string string +nucleation and then then + + align:start position:0% + + + + align:start position:0% + +disappear into + + align:start position:0% + + + + align:start position:0% + +back + + align:start position:0% +back + + + align:start position:0% +back +okay yes why do we only about CL + + align:start position:0% +okay yes why do we only about CL + + + align:start position:0% +okay yes why do we only about CL +strs because it's enough for my purpose + + align:start position:0% +strs because it's enough for my purpose + + + align:start position:0% +strs because it's enough for my purpose +now yeah + + align:start position:0% +now yeah + + + align:start position:0% +now yeah +uh I'm not trying to give you the full + + align:start position:0% +uh I'm not trying to give you the full + + + align:start position:0% +uh I'm not trying to give you the full +string at Ser at moment I'm just trying + + align:start position:0% +string at Ser at moment I'm just trying + + + align:start position:0% +string at Ser at moment I'm just trying +to give + + align:start position:0% +to give + + + align:start position:0% +to give +you the bit of string series is enough + + align:start position:0% +you the bit of string series is enough + + + align:start position:0% +you the bit of string series is enough +to make that point say the say l + + align:start position:0% +to make that point say the say l + + + align:start position:0% +to make that point say the say l +expansion is like a stre the yeah yeah + + align:start position:0% +expansion is like a stre the yeah yeah + + + align:start position:0% +expansion is like a stre the yeah yeah +because uh otherwise take the whole + + align:start position:0% +because uh otherwise take the whole + + + align:start position:0% +because uh otherwise take the whole +semester to reach the point + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +now let's look at this Taurus diagram + + align:start position:0% + + + + align:start position:0% + +because if you want to sum over all + + align:start position:0% +because if you want to sum over all + + + align:start position:0% +because if you want to sum over all +surfaces then you have to sum over + + align:start position:0% +surfaces then you have to sum over + + + align:start position:0% +surfaces then you have to sum over +different topology then you have to sum + + align:start position:0% +different topology then you have to sum + + + align:start position:0% +different topology then you have to sum +over the Taurus then let's look at what + + align:start position:0% +over the Taurus then let's look at what + + + align:start position:0% +over the Taurus then let's look at what +Taurus diagram + + align:start position:0% +Taurus diagram + + + align:start position:0% +Taurus diagram +means so let me dra the Taurus in the + + align:start position:0% +means so let me dra the Taurus in the + + + align:start position:0% +means so let me dra the Taurus in the +slightly different + + align:start position:0% + + + + align:start position:0% + +way okay okay so the + + align:start position:0% +way okay okay so the + + + align:start position:0% +way okay okay so the +Taurus again if you try to view the time + + align:start position:0% +Taurus again if you try to view the time + + + align:start position:0% +Taurus again if you try to view the time +going up then from here again you loate + + align:start position:0% +going up then from here again you loate + + + align:start position:0% +going up then from here again you loate +a single + + align:start position:0% + + + + align:start position:0% + +string but now at this time then you + + align:start position:0% +string but now at this time then you + + + align:start position:0% +string but now at this time then you +actually have two + + align:start position:0% + + + + align:start position:0% + +strings and then here you have one + + align:start position:0% +strings and then here you have one + + + align:start position:0% +strings and then here you have one +string back + + align:start position:0% +string back + + + align:start position:0% +string back +again okay then the Taurus actually + + align:start position:0% +again okay then the Taurus actually + + + align:start position:0% +again okay then the Taurus actually +describe such a virtual process is that + + align:start position:0% +describe such a virtual process is that + + + align:start position:0% +describe such a virtual process is that +you do create a string from the + + align:start position:0% +you do create a string from the + + + align:start position:0% +you do create a string from the +vacuum and then this string split into + + align:start position:0% + + + + align:start position:0% + +two split into two string and then this + + align:start position:0% +two split into two string and then this + + + align:start position:0% +two split into two string and then this +two string come back to join again to a + + align:start position:0% +two string come back to join again to a + + + align:start position:0% +two string come back to join again to a +single string and then go to the vacuum + + align:start position:0% +single string and then go to the vacuum + + + align:start position:0% +single string and then go to the vacuum +okay so so this is the uh + + align:start position:0% + + + + align:start position:0% + +nucleation out of + + align:start position:0% + + + + align:start position:0% + +vacuum and then here it + + align:start position:0% +vacuum and then here it + + + align:start position:0% +vacuum and then here it +splits so here single string splits into + + align:start position:0% +splits so here single string splits into + + + align:start position:0% +splits so here single string splits into +two string + + align:start position:0% +two string + + + align:start position:0% +two string +and then here they join together join + + align:start position:0% +and then here they join together join + + + align:start position:0% +and then here they join together join +back into single string and then here + + align:start position:0% +back into single string and then here + + + align:start position:0% +back into single string and then here +disappear into the + + align:start position:0% + + + + align:start position:0% + +vacuum okay so so we find by including + + align:start position:0% +vacuum okay so so we find by including + + + align:start position:0% +vacuum okay so so we find by including +the toal diagram you automatically + + align:start position:0% +the toal diagram you automatically + + + align:start position:0% +the toal diagram you automatically +include this kind of + + align:start position:0% +include this kind of + + + align:start position:0% +include this kind of +interaction that the string can split + + align:start position:0% +interaction that the string can split + + + align:start position:0% +interaction that the string can split +into two strings and and two strings can + + align:start position:0% +into two strings and and two strings can + + + align:start position:0% +into two strings and and two strings can +join into single string and + + align:start position:0% +join into single string and + + + align:start position:0% +join into single string and +essentially you don't have choice this + + align:start position:0% +essentially you don't have choice this + + + align:start position:0% +essentially you don't have choice this +is just determined by the + + align:start position:0% +is just determined by the + + + align:start position:0% +is just determined by the +topology okay you don't have Choice it + + align:start position:0% +topology okay you don't have Choice it + + + align:start position:0% +topology okay you don't have Choice it +just once you write down this path + + align:start position:0% +just once you write down this path + + + align:start position:0% +just once you write down this path +integral then then this is fully + + align:start position:0% +integral then then this is fully + + + align:start position:0% +integral then then this is fully +determined okay it's fully + + align:start position:0% +determined okay it's fully + + + align:start position:0% +determined okay it's fully +determined and + + align:start position:0% +determined and + + + align:start position:0% +determined and +similarly if you look at the two Loop + + align:start position:0% + + + + align:start position:0% + +process so you look at the string split + + align:start position:0% +process so you look at the string split + + + align:start position:0% +process so you look at the string split +join splits and join again so the two + + align:start position:0% +join splits and join again so the two + + + align:start position:0% +join splits and join again so the two +string again can be considered + + align:start position:0% +string again can be considered + + + align:start position:0% +string again can be considered +as such + + align:start position:0% +as such + + + align:start position:0% +as such +a + + align:start position:0% + + + + align:start position:0% + +um such in acting process so now the + + align:start position:0% +um such in acting process so now the + + + align:start position:0% +um such in acting process so now the +key so now if we compare the GS + + align:start position:0% +key so now if we compare the GS + + + align:start position:0% +key so now if we compare the GS +dependence of of these + + align:start position:0% +dependence of of these + + + align:start position:0% +dependence of of these +diagrams so so this one so each diagram + + align:start position:0% +diagrams so so this one so each diagram + + + align:start position:0% +diagrams so so this one so each diagram +compared to the earlier one + + align:start position:0% +compared to the earlier one + + + align:start position:0% +compared to the earlier one +you increase by GS to the power + + align:start position:0% +you increase by GS to the power + + + align:start position:0% +you increase by GS to the power +square but for each whenever you include + + align:start position:0% +square but for each whenever you include + + + align:start position:0% +square but for each whenever you include +the genus essentially fact include such + + align:start position:0% +the genus essentially fact include such + + + align:start position:0% +the genus essentially fact include such +a splitting and the joining so that + + align:start position:0% +a splitting and the joining so that + + + align:start position:0% +a splitting and the joining so that +means you can actually associate with + + align:start position:0% +means you can actually associate with + + + align:start position:0% +means you can actually associate with +each process to be effect of g + + align:start position:0% + + + + align:start position:0% + +string okay so for the + + align:start position:0% +string okay so for the + + + align:start position:0% +string okay so for the +sphere you have say from here say say if + + align:start position:0% +sphere you have say from here say say if + + + align:start position:0% +sphere you have say from here say say if +raliz string sphere to be gsus + + align:start position:0% + + + + align:start position:0% + +2 then now if you + + align:start position:0% + + + + align:start position:0% + +include so essentially this + + align:start position:0% +include so essentially this + + + align:start position:0% +include so essentially this +weight this weight which we added here + + align:start position:0% +weight this weight which we added here + + + align:start position:0% +weight this weight which we added here +is to await for such a splitting and + + align:start position:0% +is to await for such a splitting and + + + align:start position:0% +is to await for such a splitting and +joining process so each splitting and + + align:start position:0% +joining process so each splitting and + + + align:start position:0% +joining process so each splitting and +joining give you weight of g string okay + + align:start position:0% +joining give you weight of g string okay + + + align:start position:0% +joining give you weight of g string okay +weight g string so in some sense we + + align:start position:0% +weight g string so in some sense we + + + align:start position:0% +weight g string so in some sense we +concluded + + align:start position:0% + + + + align:start position:0% + +that so we concluded that so the + + align:start position:0% +that so we concluded that so the + + + align:start position:0% +that so we concluded that so the +basic + + align:start position:0% +basic + + + align:start position:0% +basic +string interaction + + align:start position:0% +string interaction + + + align:start position:0% +string interaction +vertex it just a single + + align:start position:0% +vertex it just a single + + + align:start position:0% +vertex it just a single +string can join into two + + align:start position:0% + + + + align:start position:0% + +string or or two string or or single + + align:start position:0% +string or or two string or or single + + + align:start position:0% +string or or two string or or single +string can split into two + + align:start position:0% + + + + align:start position:0% + +string or two string can join into a + + align:start position:0% +string or two string can join into a + + + align:start position:0% +string or two string can join into a +single string and the weight for each + + align:start position:0% +single string and the weight for each + + + align:start position:0% +single string and the weight for each +process is given by G + + align:start position:0% +process is given by G + + + align:start position:0% +process is given by G +string okay so so that's effectively + + align:start position:0% +string okay so so that's effectively + + + align:start position:0% +string okay so so that's effectively +what this mathematical trick + + align:start position:0% +what this mathematical trick + + + align:start position:0% +what this mathematical trick +does so effective what this mathematical + + align:start position:0% +does so effective what this mathematical + + + align:start position:0% +does so effective what this mathematical +trick does is to assign a weight for + + align:start position:0% +trick does is to assign a weight for + + + align:start position:0% +trick does is to assign a weight for +each such a splitting process yes so if + + align:start position:0% +each such a splitting process yes so if + + + align:start position:0% +each such a splitting process yes so if +you start the nucle so you drew it like + + align:start position:0% +you start the nucle so you drew it like + + + align:start position:0% +you start the nucle so you drew it like +this for the two thing but if you start + + align:start position:0% +this for the two thing but if you start + + + align:start position:0% +this for the two thing but if you start +the nucleation from the side rather than + + align:start position:0% +the nucleation from the side rather than + + + align:start position:0% +the nucleation from the side rather than +the bottom then wouldn't it like split + + align:start position:0% +the bottom then wouldn't it like split + + + align:start position:0% +the bottom then wouldn't it like split +into three and then back into one that's + + align:start position:0% +into three and then back into one that's + + + align:start position:0% +into three and then back into one that's +right that's uh you uh yeah it's + + align:start position:0% +right that's uh you uh yeah it's + + + align:start position:0% +right that's uh you uh yeah it's +uh because of the topology you you can + + align:start position:0% +uh because of the topology you you can + + + align:start position:0% +uh because of the topology you you can +split in in arbitary way and this + + align:start position:0% +split in in arbitary way and this + + + align:start position:0% +split in in arbitary way and this +get this just tells you using this basic + + align:start position:0% +get this just tells you using this basic + + + align:start position:0% +get this just tells you using this basic +vertex then then for fixed + + align:start position:0% +vertex then then for fixed + + + align:start position:0% +vertex then then for fixed +paret uh yeah just this vertex already + + align:start position:0% +paret uh yeah just this vertex already + + + align:start position:0% +paret uh yeah just this vertex already +enough and you can indeed it's a very + + align:start position:0% +enough and you can indeed it's a very + + + align:start position:0% +enough and you can indeed it's a very +good question you can try to uh snce the + + align:start position:0% +good question you can try to uh snce the + + + align:start position:0% +good question you can try to uh snce the +dag in arbitary way then that may give + + align:start position:0% +dag in arbitary way then that may give + + + align:start position:0% +dag in arbitary way then that may give +you some arbitary other things then + + align:start position:0% +you some arbitary other things then + + + align:start position:0% +you some arbitary other things then +that's fine and then you can assign + + align:start position:0% +that's fine and then you can assign + + + align:start position:0% +that's fine and then you can assign +weight for some some other vertices but + + align:start position:0% +weight for some some other vertices but + + + align:start position:0% +weight for some some other vertices but +but they will be all consistent with + + align:start position:0% +but they will be all consistent with + + + align:start position:0% +but they will be all consistent with +this fundamental + + align:start position:0% + + + + align:start position:0% + +vertices so so essentially this + + align:start position:0% +vertices so so essentially this + + + align:start position:0% +vertices so so essentially this +GS which I called to be + + align:start position:0% +GS which I called to be + + + align:start position:0% +GS which I called to be +Lambda is essentially the cing for the + + align:start position:0% +Lambda is essentially the cing for the + + + align:start position:0% +Lambda is essentially the cing for the +string + + align:start position:0% +string + + + align:start position:0% +string +okay essentially determines the strength + + align:start position:0% +okay essentially determines the strength + + + align:start position:0% +okay essentially determines the strength +of the string + + align:start position:0% + + + + align:start position:0% + +interactions yeah our choice of weight + + align:start position:0% +interactions yeah our choice of weight + + + align:start position:0% +interactions yeah our choice of weight +is not unique do something ugly like + + align:start position:0% +is not unique do something ugly like + + + align:start position:0% +is not unique do something ugly like +sare and + + align:start position:0% +sare and + + + align:start position:0% +sare and +then + + align:start position:0% +then + + + align:start position:0% +then +um yeah that's a good point indeed + + align:start position:0% +um yeah that's a good point indeed + + + align:start position:0% +um yeah that's a good point indeed +indeed yeah uh uh uh so here so here is + + align:start position:0% +indeed yeah uh uh uh so here so here is + + + align:start position:0% +indeed yeah uh uh uh so here so here is +the simplest choice and it's a choice + + align:start position:0% +the simplest choice and it's a choice + + + align:start position:0% +the simplest choice and it's a choice +which you can uh um um yeah yeah so so + + align:start position:0% +which you can uh um um yeah yeah so so + + + align:start position:0% +which you can uh um um yeah yeah so so +this is the simplest choice you can put + + align:start position:0% +this is the simplest choice you can put + + + align:start position:0% +this is the simplest choice you can put +and this is a choice which will also + + align:start position:0% +and this is a choice which will also + + + align:start position:0% +and this is a choice which will also +arise if you properly quanti string + + align:start position:0% +arise if you properly quanti string + + + align:start position:0% +arise if you properly quanti string +series and indeed you can write down + + align:start position:0% +series and indeed you can write down + + + align:start position:0% +series and indeed you can write down +some other string series with a + + align:start position:0% +some other string series with a + + + align:start position:0% +some other string series with a +different Power it might be + + align:start position:0% +different Power it might be + + + align:start position:0% +different Power it might be +possible yeah I mean just as a maical + + align:start position:0% +possible yeah I mean just as a maical + + + align:start position:0% +possible yeah I mean just as a maical +say at a mathematical level L prevent + + align:start position:0% +say at a mathematical level L prevent + + + align:start position:0% +say at a mathematical level L prevent +you to add some arbitrary function of + + align:start position:0% +you to add some arbitrary function of + + + align:start position:0% +you to add some arbitrary function of +Kai and uh and this is just a simplest + + align:start position:0% +Kai and uh and this is just a simplest + + + align:start position:0% +Kai and uh and this is just a simplest +way to do it and this is the way we rise + + align:start position:0% +way to do it and this is the way we rise + + + align:start position:0% +way to do it and this is the way we rise +out of screen Series yeah uh this is so + + align:start position:0% +out of screen Series yeah uh this is so + + + align:start position:0% +out of screen Series yeah uh this is so +this process is not arbitrary it's + + align:start position:0% +this process is not arbitrary it's + + + align:start position:0% +this process is not arbitrary it's +something which you can derive from scen + + align:start position:0% +something which you can derive from scen + + + align:start position:0% +something which you can derive from scen +Ser + + align:start position:0% +Ser + + + align:start position:0% +Ser +yeah just here I will not go through the + + align:start position:0% +yeah just here I will not go through the + + + align:start position:0% +yeah just here I will not go through the +whole + + align:start position:0% +whole + + + align:start position:0% +whole +thing any other questions um do we have + + align:start position:0% +thing any other questions um do we have + + + align:start position:0% +thing any other questions um do we have +an extra minus sign in the EXP no + + align:start position:0% +an extra minus sign in the EXP no + + + align:start position:0% +an extra minus sign in the EXP no +because more negative as H + + align:start position:0% +because more negative as H + + + align:start position:0% +because more negative as H +increases the exponent becomes larger + + align:start position:0% +increases the exponent becomes larger + + + align:start position:0% +increases the exponent becomes larger +and larger yeah yeah yeah because the + + align:start position:0% +and larger yeah yeah yeah because the + + + align:start position:0% +and larger yeah yeah yeah because the +yeah I can take G to be + + align:start position:0% + + + + align:start position:0% + +small yeah yeah the only thing is I'm I + + align:start position:0% +small yeah yeah the only thing is I'm I + + + align:start position:0% +small yeah yeah the only thing is I'm I +want to be consistent with this + + align:start position:0% + + + + align:start position:0% + +power so now here is the key so now + + align:start position:0% +power so now here is the key so now + + + align:start position:0% +power so now here is the key so now +let's look at the external + + align:start position:0% + + + + align:start position:0% + +strings so here at the beginning I was + + align:start position:0% +strings so here at the beginning I was + + + align:start position:0% +strings so here at the beginning I was +looking at the uh um + + align:start position:0% +looking at the uh um + + + align:start position:0% +looking at the uh um +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +I being I was looking at the vacuum + + align:start position:0% +I being I was looking at the vacuum + + + align:start position:0% +I being I was looking at the vacuum +process there was nothing just + + align:start position:0% +process there was nothing just + + + align:start position:0% +process there was nothing just +everything come out of the vacuum but + + align:start position:0% +everything come out of the vacuum but + + + align:start position:0% +everything come out of the vacuum but +you can also consider say some process + + align:start position:0% +you can also consider say some process + + + align:start position:0% +you can also consider say some process +say you start with two + + align:start position:0% +say you start with two + + + align:start position:0% +say you start with two +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +strings then you scatter them together + + align:start position:0% +strings then you scatter them together + + + align:start position:0% +strings then you scatter them together +you get two string + + align:start position:0% +you get two string + + + align:start position:0% +you get two string +back so you can also consider such kind + + align:start position:0% +back so you can also consider such kind + + + align:start position:0% +back so you can also consider such kind +of string so you started with actually + + align:start position:0% +of string so you started with actually + + + align:start position:0% +of string so you started with actually +two initial + + align:start position:0% +two initial + + + align:start position:0% +two initial +strings and then through some + + align:start position:0% +strings and then through some + + + align:start position:0% +strings and then through some +complicated interaction you have some + + align:start position:0% +complicated interaction you have some + + + align:start position:0% +complicated interaction you have some +two string back okay so for example this + + align:start position:0% +two string back okay so for example this + + + align:start position:0% +two string back okay so for example this +would be such kind of + + align:start position:0% + + + + align:start position:0% + +process again anything can happen + + align:start position:0% +process again anything can happen + + + align:start position:0% +process again anything can happen +between I have two initial + + align:start position:0% +between I have two initial + + + align:start position:0% +between I have two initial +strings two initial + + align:start position:0% +strings two initial + + + align:start position:0% +strings two initial +strings but I have two final string come + + align:start position:0% + + + + align:start position:0% + +out okay so this would be some kind of + + align:start position:0% +out okay so this would be some kind of + + + align:start position:0% +out okay so this would be some kind of +surfaces so this will correspondent you + + align:start position:0% +surfaces so this will correspondent you + + + align:start position:0% +surfaces so this will correspondent you +have the sum of all possible surfaces + + align:start position:0% +have the sum of all possible surfaces + + + align:start position:0% +have the sum of all possible surfaces +with four external string uh uh uh uh + + align:start position:0% +with four external string uh uh uh uh + + + align:start position:0% +with four external string uh uh uh uh +say two come in from minus infinity and + + align:start position:0% +say two come in from minus infinity and + + + align:start position:0% +say two come in from minus infinity and +two come from tal to plus two come out + + align:start position:0% +two come from tal to plus two come out + + + align:start position:0% +two come from tal to plus two come out +at t plus infinity + + align:start position:0% +at t plus infinity + + + align:start position:0% +at t plus infinity +okay and again you need to sum of oppos + + align:start position:0% +okay and again you need to sum of oppos + + + align:start position:0% +okay and again you need to sum of oppos +topology in + + align:start position:0% +topology in + + + align:start position:0% +topology in +between say you you you you sum of a + + align:start position:0% +between say you you you you sum of a + + + align:start position:0% +between say you you you you sum of a +sphere in + + align:start position:0% + + + + align:start position:0% + +between yeah let me just uh uh uh save + + align:start position:0% +between yeah let me just uh uh uh save + + + align:start position:0% +between yeah let me just uh uh uh save +time draw it + + align:start position:0% + + + + align:start position:0% + +quickly so so you can sum over all + + align:start position:0% +quickly so so you can sum over all + + + align:start position:0% +quickly so so you can sum over all +spheres in between some spheres or you + + align:start position:0% +spheres in between some spheres or you + + + align:start position:0% +spheres in between some spheres or you +sum over + + align:start position:0% + + + + align:start position:0% + +Taurus + + align:start position:0% + + + + align:start position:0% + +ex + + align:start position:0% + + + + align:start position:0% + +okay but now if if you do this weight + + align:start position:0% +okay but now if if you do this weight + + + align:start position:0% +okay but now if if you do this weight +according to this + + align:start position:0% +according to this + + + align:start position:0% +according to this +rule okay now if you do the weight + + align:start position:0% +rule okay now if you do the weight + + + align:start position:0% +rule okay now if you do the weight +according to this rule something + + align:start position:0% +according to this rule something + + + align:start position:0% +according to this rule something +changed because the again again we want + + align:start position:0% +changed because the again again we want + + + align:start position:0% +changed because the again again we want +to sum of all possible surfaces with the + + align:start position:0% +to sum of all possible surfaces with the + + + align:start position:0% +to sum of all possible surfaces with the +same rule as you do for the + + align:start position:0% +same rule as you do for the + + + align:start position:0% +same rule as you do for the +vacuum but now there's something + + align:start position:0% +vacuum but now there's something + + + align:start position:0% +vacuum but now there's something +important + + align:start position:0% +important + + + align:start position:0% +important +changes he said this kind of + + align:start position:0% +changes he said this kind of + + + align:start position:0% +changes he said this kind of +surfaces so these are the curves with + + align:start position:0% +surfaces so these are the curves with + + + align:start position:0% +surfaces so these are the curves with +the boundaries so you want to start with + + align:start position:0% +the boundaries so you want to start with + + + align:start position:0% +the boundaries so you want to start with +two two initial external two initial + + align:start position:0% +two two initial external two initial + + + align:start position:0% +two two initial external two initial +strings and two final strings so each + + align:start position:0% +strings and two final strings so each + + + align:start position:0% +strings and two final strings so each +initial string introduce a boundary so + + align:start position:0% +initial string introduce a boundary so + + + align:start position:0% +initial string introduce a boundary so +now you have two four different + + align:start position:0% +now you have two four different + + + align:start position:0% +now you have two four different +boundaries so you have four + + align:start position:0% +boundaries so you have four + + + align:start position:0% +boundaries so you have four +boundaries and so so when you introduce + + align:start position:0% +boundaries and so so when you introduce + + + align:start position:0% +boundaries and so so when you introduce +boundaries into a two dimensional + + align:start position:0% +boundaries into a two dimensional + + + align:start position:0% +boundaries into a two dimensional +surfaces then the oil number + + align:start position:0% +surfaces then the oil number + + + align:start position:0% +surfaces then the oil number +changes so some of you already may know + + align:start position:0% +changes so some of you already may know + + + align:start position:0% +changes so some of you already may know +this from high + + align:start position:0% +this from high + + + align:start position:0% +this from high +school 2 minus H and minus + + align:start position:0% +school 2 minus H and minus + + + align:start position:0% +school 2 minus H and minus +n and n is the number of + + align:start position:0% + + + + align:start position:0% + +boundaries okay number of boundaries and + + align:start position:0% +boundaries okay number of boundaries and + + + align:start position:0% +boundaries okay number of boundaries and +which is the same as the number of + + align:start position:0% +which is the same as the number of + + + align:start position:0% +which is the same as the number of +number of external + + align:start position:0% + + + + align:start position:0% + +strings number of external + + align:start position:0% +strings number of external + + + align:start position:0% +strings number of external +strings okay so now if you use this + + align:start position:0% +strings okay so now if you use this + + + align:start position:0% +strings okay so now if you use this +rule so now for the end string + + align:start position:0% +rule so now for the end string + + + align:start position:0% +rule so now for the end string +scattering + + align:start position:0% + + + + align:start position:0% + +for ning scattering so let me call this + + align:start position:0% +for ning scattering so let me call this + + + align:start position:0% +for ning scattering so let me call this +n a n then you will again Su of all + + align:start position:0% + + + + align:start position:0% + +Genesis so now this + + align:start position:0% +Genesis so now this + + + align:start position:0% +Genesis so now this +weight when I translate into + + align:start position:0% +weight when I translate into + + + align:start position:0% +weight when I translate into +GS become nus 2 - 2 H or plus 2 + + align:start position:0% +GS become nus 2 - 2 H or plus 2 + + + align:start position:0% +GS become nus 2 - 2 H or plus 2 +H Okay so now because of this + + align:start position:0% +H Okay so now because of this + + + align:start position:0% +H Okay so now because of this +n so I have additional power of GS to + + align:start position:0% +n so I have additional power of GS to + + + align:start position:0% +n so I have additional power of GS to +the power + + align:start position:0% +the power + + + align:start position:0% +the power +n say say I can write as FN H + + align:start position:0% + + + + align:start position:0% + +okay so so if you look at the + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +sum so if you look at the + + align:start position:0% +sum so if you look at the + + + align:start position:0% +sum so if you look at the +sum so if you look at the sum so so this + + align:start position:0% +sum so if you look at the sum so so this + + + align:start position:0% +sum so if you look at the sum so so this +is GS to the^ nus 2 come from the + + align:start position:0% + + + + align:start position:0% + +sphere sphere surface spherical surfaces + + align:start position:0% +sphere sphere surface spherical surfaces + + + align:start position:0% +sphere sphere surface spherical surfaces +which can also be considered as a tree + + align:start position:0% +which can also be considered as a tree + + + align:start position:0% +which can also be considered as a tree +level from the string point of view + + align:start position:0% +level from the string point of view + + + align:start position:0% +level from the string point of view +because the string just come out and + + align:start position:0% +because the string just come out and + + + align:start position:0% +because the string just come out and +nucleate and then the next order is GS + + align:start position:0% +nucleate and then the next order is GS + + + align:start position:0% +nucleate and then the next order is GS +to the + + align:start position:0% +to the + + + align:start position:0% +to the +GSN then this is + + align:start position:0% +GSN then this is + + + align:start position:0% +GSN then this is +Taurus topology so this may be consider + + align:start position:0% +Taurus topology so this may be consider + + + align:start position:0% +Taurus topology so this may be consider +is some kind of one Loop process and GS + + align:start position:0% +is some kind of one Loop process and GS + + + align:start position:0% +is some kind of one Loop process and GS +m+ 2 so this is Genus + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +now let's compare with this so so so + + align:start position:0% +now let's compare with this so so so + + + align:start position:0% +now let's compare with this so so so +this also include in the vacuum for the + + align:start position:0% +this also include in the vacuum for the + + + align:start position:0% +this also include in the vacuum for the +vacuum you just set n equal to + + align:start position:0% +vacuum you just set n equal to + + + align:start position:0% +vacuum you just set n equal to +Zer okay just send in to zero so now we + + align:start position:0% +Zer okay just send in to zero so now we + + + align:start position:0% +Zer okay just send in to zero so now we +see exactly + + align:start position:0% +see exactly + + + align:start position:0% +see exactly +parallel with what we + + align:start position:0% +parallel with what we + + + align:start position:0% +parallel with what we +see in the larage + + align:start position:0% +see in the larage + + + align:start position:0% +see in the larage +series in both cases you have summing + + align:start position:0% +series in both cases you have summing + + + align:start position:0% +series in both cases you have summing +over + + align:start position:0% +over + + + align:start position:0% +over +topology and in both cases we have + + align:start position:0% +topology and in both cases we have + + + align:start position:0% +topology and in both cases we have +summing you have this + + align:start position:0% +summing you have this + + + align:start position:0% +summing you have this +expansion and + + align:start position:0% +expansion and + + + align:start position:0% +expansion and +uh + + align:start position:0% + + + + align:start position:0% + +so so identical + + align:start position:0% + + + + align:start position:0% + +mathematical + + align:start position:0% + + + + align:start position:0% + +structure + + align:start position:0% + + + + align:start position:0% + +with + + align:start position:0% +with + + + align:start position:0% +with +nen + + align:start position:0% + + + + align:start position:0% + +expansion in + + align:start position:0% +expansion in + + + align:start position:0% +expansion in +particular g string now corresponding to + + align:start position:0% +particular g string now corresponding to + + + align:start position:0% +particular g string now corresponding to +just one/ + + align:start position:0% +just one/ + + + align:start position:0% +just one/ +n and this external + + align:start position:0% + + + + align:start position:0% + +strings say if you have + + align:start position:0% +strings say if you have + + + align:start position:0% +strings say if you have +some just corresponding to the + + align:start position:0% +some just corresponding to the + + + align:start position:0% +some just corresponding to the +globos what we call the + + align:start position:0% +globos what we call the + + + align:start position:0% +globos what we call the +gloos so this kind of single Chace + + align:start position:0% + + + + align:start position:0% + +operators and the sum of + + align:start position:0% +operators and the sum of + + + align:start position:0% +operators and the sum of +string over string + + align:start position:0% + + + + align:start position:0% + +worksheet of say + + align:start position:0% +worksheet of say + + + align:start position:0% +worksheet of say +topology of genus + + align:start position:0% + + + + align:start position:0% + +H it's then a map to say some overment + + align:start position:0% +H it's then a map to say some overment + + + align:start position:0% +H it's then a map to say some overment +diagrams + + align:start position:0% + + + + align:start position:0% + +of genus + + align:start position:0% + + + + align:start position:0% + +H yeah so you see so exactly parallel + + align:start position:0% +H yeah so you see so exactly parallel + + + align:start position:0% +H yeah so you see so exactly parallel +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +structure between the + + align:start position:0% +structure between the + + + align:start position:0% +structure between the +two so the question is whe is this a + + align:start position:0% +two so the question is whe is this a + + + align:start position:0% +two so the question is whe is this a +accident or this is something deep + + align:start position:0% + + + + align:start position:0% + +okay I think I'm running out of time + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +yeah okay maybe I will stop + + align:start position:0% + + + + align:start position:0% + +here you don't want to + + align:start position:0% +here you don't want to + + + align:start position:0% +here you don't want to +stop only one and a half pages left um + + align:start position:0% + + + + align:start position:0% + +okay yeah let me just say a few + + align:start position:0% + + + + align:start position:0% + +words let me say a few words if you look + + align:start position:0% +words let me say a few words if you look + + + align:start position:0% +words let me say a few words if you look +at these two + + align:start position:0% + + + + align:start position:0% + +sums this + + align:start position:0% + + + + align:start position:0% + +sum and this sum oh yeah let me call + + align:start position:0% +sum and this sum oh yeah let me call + + + align:start position:0% +sum and this sum oh yeah let me call +this FN so that the distinction let me + + align:start position:0% +this FN so that the distinction let me + + + align:start position:0% +this FN so that the distinction let me +call this F so that + + align:start position:0% +call this F so that + + + align:start position:0% +call this F so that +F so if you look at these two + + align:start position:0% + + + + align:start position:0% + +sums so the question is can you really + + align:start position:0% +sums so the question is can you really + + + align:start position:0% +sums so the question is can you really +physically identify this two + + align:start position:0% + + + + align:start position:0% + +okay yeah just say let me just say a + + align:start position:0% +okay yeah just say let me just say a + + + align:start position:0% +okay yeah just say let me just say a +couple + + align:start position:0% + + + + align:start position:0% + +words say fnh + + align:start position:0% +words say fnh + + + align:start position:0% +words say fnh +h which appear in the correlation + + align:start position:0% +h which appear in the correlation + + + align:start position:0% +h which appear in the correlation +functions essentially just some over + + align:start position:0% +functions essentially just some over + + + align:start position:0% +functions essentially just some over +five some over five + + align:start position:0% + + + + align:start position:0% + +diagrams of genus age + + align:start position:0% + + + + align:start position:0% + +and this is the just the F diagrams the + + align:start position:0% +and this is the just the F diagrams the + + + align:start position:0% +and this is the just the F diagrams the +expression for the F + + align:start position:0% + + + + align:start position:0% + +diagrams and this one this + + align:start position:0% +diagrams and this one this + + + align:start position:0% +diagrams and this one this +FH + + align:start position:0% +FH + + + align:start position:0% +FH +fnh so this is sum + + align:start position:0% + + + + align:start position:0% + +over this is path integral say minus S + + align:start position:0% +over this is path integral say minus S + + + align:start position:0% +over this is path integral say minus S +and + + align:start position:0% +and + + + align:start position:0% +and +G of genus h + + align:start position:0% + + + + align:start position:0% + +surfaces so now + + align:start position:0% +surfaces so now + + + align:start position:0% +surfaces so now +remember so now remember one thing we + + align:start position:0% +remember so now remember one thing we + + + align:start position:0% +remember so now remember one thing we +said + + align:start position:0% +said + + + align:start position:0% +said +before is that each fman + + align:start position:0% + + + + align:start position:0% + +diagram each fman + + align:start position:0% + + + + align:start position:0% + +diagram can be considered + + align:start position:0% + + + + align:start position:0% + +as a + + align:start position:0% + + + + align:start position:0% + +partition of a 2d + + align:start position:0% + + + + align:start position:0% + +surface okay so now if you sum of all + + align:start position:0% +surface okay so now if you sum of all + + + align:start position:0% +surface okay so now if you sum of all +possible fan + + align:start position:0% +possible fan + + + align:start position:0% +possible fan +diagrams so you can also think of it + + align:start position:0% +diagrams so you can also think of it + + + align:start position:0% +diagrams so you can also think of it +geometrically as some over all + + align:start position:0% + + + + align:start position:0% + +possible triangulations of a surface + + align:start position:0% +possible triangulations of a surface + + + align:start position:0% +possible triangulations of a surface +conations of a + + align:start position:0% + + + + align:start position:0% + +surface so this are this kind of + + align:start position:0% +surface so this are this kind of + + + align:start position:0% +surface so this are this kind of +partition essentially just a + + align:start position:0% +partition essentially just a + + + align:start position:0% +partition essentially just a +triangularization of the surfaces + + align:start position:0% +triangularization of the surfaces + + + align:start position:0% +triangularization of the surfaces +divided into different parts and with + + align:start position:0% +divided into different parts and with + + + align:start position:0% +divided into different parts and with +some altitude with some weight so Su of + + align:start position:0% +some altitude with some weight so Su of + + + align:start position:0% +some altitude with some weight so Su of +allos triangulation of the surface of + + align:start position:0% +allos triangulation of the surface of + + + align:start position:0% +allos triangulation of the surface of +course this is + + align:start position:0% +course this is + + + align:start position:0% +course this is +precisely just a + + align:start position:0% + + + + align:start position:0% + +discrete + + align:start position:0% +discrete + + + align:start position:0% +discrete +form of summing over all summing over + + align:start position:0% +form of summing over all summing over + + + align:start position:0% +form of summing over all summing over +all + + align:start position:0% + + + + align:start position:0% + +surfaces so this is a disc for discrete + + align:start position:0% +surfaces so this is a disc for discrete + + + align:start position:0% +surfaces so this is a disc for discrete +sum of sum of all + + align:start position:0% +sum of sum of all + + + align:start position:0% +sum of sum of all +surfaces and so so this really identify + + align:start position:0% +surfaces and so so this really identify + + + align:start position:0% +surfaces and so so this really identify +these + + align:start position:0% +these + + + align:start position:0% +these +two are essentially the same object so + + align:start position:0% +two are essentially the same object so + + + align:start position:0% +two are essentially the same object so +when you summing over diagrams you are + + align:start position:0% +when you summing over diagrams you are + + + align:start position:0% +when you summing over diagrams you are +actually summing inly actually summing + + align:start position:0% +actually summing inly actually summing + + + align:start position:0% +actually summing inly actually summing +over all possible edance of some + + align:start position:0% +over all possible edance of some + + + align:start position:0% +over all possible edance of some +surfaces in space time and the precise L + + align:start position:0% +surfaces in space time and the precise L + + + align:start position:0% +surfaces in space time and the precise L +of that surface of course depends + + align:start position:0% +of that surface of course depends + + + align:start position:0% +of that surface of course depends +on uh the diagram + + align:start position:0% +on uh the diagram + + + align:start position:0% +on uh the diagram +itself diagam itself so this really + + align:start position:0% +itself diagam itself so this really + + + align:start position:0% +itself diagam itself so this really +tells you that the + + align:start position:0% +tells you that the + + + align:start position:0% +tells you that the +Len expansion is + + align:start position:0% +Len expansion is + + + align:start position:0% +Len expansion is +really just a string + + align:start position:0% +really just a string + + + align:start position:0% +really just a string +theory okay it's really just a string + + align:start position:0% +theory okay it's really just a string + + + align:start position:0% +theory okay it's really just a string +the and but from here you cannot + + align:start position:0% +the and but from here you cannot + + + align:start position:0% +the and but from here you cannot +immediately tell what kind of string + + align:start position:0% +immediately tell what kind of string + + + align:start position:0% +immediately tell what kind of string +theory is this because from F diagram + + align:start position:0% +theory is this because from F diagram + + + align:start position:0% +theory is this because from F diagram +itself so this L goal action which I I + + align:start position:0% +itself so this L goal action which I I + + + align:start position:0% +itself so this L goal action which I I +wrote earlier corresponding to you map + + align:start position:0% +wrote earlier corresponding to you map + + + align:start position:0% +wrote earlier corresponding to you map +from some surface embedding of some + + align:start position:0% +from some surface embedding of some + + + align:start position:0% +from some surface embedding of some +surface in some space time and that + + align:start position:0% +surface in some space time and that + + + align:start position:0% +surface in some space time and that +space time can be some arbitrary space + + align:start position:0% +space time can be some arbitrary space + + + align:start position:0% +space time can be some arbitrary space +time EX for different space time of + + align:start position:0% +time EX for different space time of + + + align:start position:0% +time EX for different space time of +course you get a different action so the + + align:start position:0% +course you get a different action so the + + + align:start position:0% +course you get a different action so the +question is what does this correspond to + + align:start position:0% +question is what does this correspond to + + + align:start position:0% +question is what does this correspond to +so I give you a set of I give you a fi + + align:start position:0% +so I give you a set of I give you a fi + + + align:start position:0% +so I give you a set of I give you a fi +series and you have those fan diagrams + + align:start position:0% +series and you have those fan diagrams + + + align:start position:0% +series and you have those fan diagrams +and what F what and for each fan diagram + + align:start position:0% +and what F what and for each fan diagram + + + align:start position:0% +and what F what and for each fan diagram +you can write expression for them just + + align:start position:0% +you can write expression for them just + + + align:start position:0% +you can write expression for them just +whether this really corresponding to say + + align:start position:0% +whether this really corresponding to say + + + align:start position:0% +whether this really corresponding to say +some geometric action the F diag whether + + align:start position:0% +some geometric action the F diag whether + + + align:start position:0% +some geometric action the F diag whether +really corresponding some geometrical + + align:start position:0% +really corresponding some geometrical + + + align:start position:0% +really corresponding some geometrical +action describing the motion of some + + align:start position:0% +action describing the motion of some + + + align:start position:0% +action describing the motion of some +surface in some space time yeah yeah so + + align:start position:0% +surface in some space time yeah yeah so + + + align:start position:0% +surface in some space time yeah yeah so +so let me just stop here \ No newline at end of file diff --git a/MAyraVVYB64.txt b/MAyraVVYB64.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a0dd2592cddc19039f3e386b3de277c06e35f77 --- /dev/null +++ b/MAyraVVYB64.txt @@ -0,0 +1,18696 @@ +align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +welcome to our fourth problem session + + align:start position:0% +welcome to our fourth problem session + + + align:start position:0% +welcome to our fourth problem session +uh we're going to be talking about + + align:start position:0% +uh we're going to be talking about + + + align:start position:0% +uh we're going to be talking about +binary trees mostly today we'll talk a + + align:start position:0% +binary trees mostly today we'll talk a + + + align:start position:0% +binary trees mostly today we'll talk a +little bit about + + align:start position:0% +little bit about + + + align:start position:0% +little bit about +binary heaps which is a topic we won't + + align:start position:0% +binary heaps which is a topic we won't + + + align:start position:0% +binary heaps which is a topic we won't +cover until + + align:start position:0% +cover until + + + align:start position:0% +cover until +next tuesday but it will appear + + align:start position:0% +next tuesday but it will appear + + + align:start position:0% +next tuesday but it will appear +in a very small ways on your problem set + + align:start position:0% +in a very small ways on your problem set + + + align:start position:0% +in a very small ways on your problem set +four which will be due next friday + + align:start position:0% +four which will be due next friday + + + align:start position:0% +four which will be due next friday +so i'm going to go over a little bit of + + align:start position:0% +so i'm going to go over a little bit of + + + align:start position:0% +so i'm going to go over a little bit of +that material today + + align:start position:0% +that material today + + + align:start position:0% +that material today +but it's mostly concern the the subject + + align:start position:0% +but it's mostly concern the the subject + + + align:start position:0% +but it's mostly concern the the subject +material for today is mostly + + align:start position:0% +material for today is mostly + + + align:start position:0% +material for today is mostly +uh binary trees specifically + + align:start position:0% +uh binary trees specifically + + + align:start position:0% +uh binary trees specifically +being applied to set data structures and + + align:start position:0% +being applied to set data structures and + + + align:start position:0% +being applied to set data structures and +sequence data structures + + align:start position:0% +sequence data structures + + + align:start position:0% +sequence data structures +as uh professor domain talked to you + + align:start position:0% +as uh professor domain talked to you + + + align:start position:0% +as uh professor domain talked to you +earlier this week um but + + align:start position:0% +earlier this week um but + + + align:start position:0% +earlier this week um but +for now uh actually as of yesterday + + align:start position:0% +for now uh actually as of yesterday + + + align:start position:0% +for now uh actually as of yesterday +you've seen all of the data structures + + align:start position:0% +you've seen all of the data structures + + + align:start position:0% +you've seen all of the data structures +that we're going to cover + + align:start position:0% +that we're going to cover + + + align:start position:0% +that we're going to cover +to imp that that will implement the set + + align:start position:0% +to imp that that will implement the set + + + align:start position:0% +to imp that that will implement the set +interface and the sequence interface + + align:start position:0% +interface and the sequence interface + + + align:start position:0% +interface and the sequence interface +right those uh those nice tables that + + align:start position:0% +right those uh those nice tables that + + + align:start position:0% +right those uh those nice tables that +uh professor domain has been showing you + + align:start position:0% +uh professor domain has been showing you + + + align:start position:0% +uh professor domain has been showing you +right + + align:start position:0% +right + + + align:start position:0% +right +uh those are now complete right we have + + align:start position:0% +uh those are now complete right we have + + + align:start position:0% +uh those are now complete right we have +uh some data structures that are really + + align:start position:0% +uh some data structures that are really + + + align:start position:0% +uh some data structures that are really +good constant time + + align:start position:0% +good constant time + + + align:start position:0% +good constant time +operations for some operations so we + + align:start position:0% +operations for some operations so we + + + align:start position:0% +operations for some operations so we +might choose them for some + + align:start position:0% +might choose them for some + + + align:start position:0% +might choose them for some +uh applications and this week + + align:start position:0% +uh applications and this week + + + align:start position:0% +uh applications and this week +we've been describing to you trees which + + align:start position:0% +we've been describing to you trees which + + + align:start position:0% +we've been describing to you trees which +achieve like really pretty good for any + + align:start position:0% +achieve like really pretty good for any + + + align:start position:0% +achieve like really pretty good for any +type of query operation on my + + align:start position:0% +type of query operation on my + + + align:start position:0% +type of query operation on my +sets or sequences pretty good meaning + + align:start position:0% +sets or sequences pretty good meaning + + + align:start position:0% +sets or sequences pretty good meaning +logarithmic time not quite constant + + align:start position:0% +logarithmic time not quite constant + + + align:start position:0% +logarithmic time not quite constant +but for our purposes log n is + + align:start position:0% +but for our purposes log n is + + + align:start position:0% +but for our purposes log n is +i mean on your computer practically + + align:start position:0% +i mean on your computer practically + + + align:start position:0% +i mean on your computer practically +right not asymptotically but practically + + align:start position:0% +right not asymptotically but practically + + + align:start position:0% +right not asymptotically but practically +log n is going to be at most what + + align:start position:0% +log n is going to be at most what + + + align:start position:0% +log n is going to be at most what +on your computer + + align:start position:0% + + + + align:start position:0% + +something like 64 right + + align:start position:0% +something like 64 right + + + align:start position:0% +something like 64 right +any input that you're operating on with + + align:start position:0% +any input that you're operating on with + + + align:start position:0% +any input that you're operating on with +uh and machine words as your input right + + align:start position:0% +uh and machine words as your input right + + + align:start position:0% +uh and machine words as your input right +uh you need to be able to address all + + align:start position:0% +uh you need to be able to address all + + + align:start position:0% +uh you need to be able to address all +those machine words right + + align:start position:0% +those machine words right + + + align:start position:0% +those machine words right +in in your input and on your computer + + align:start position:0% +in in your input and on your computer + + + align:start position:0% +in in your input and on your computer +the size of your machine word addresses + + align:start position:0% +the size of your machine word addresses + + + align:start position:0% +the size of your machine word addresses +is 64 bits + + align:start position:0% +is 64 bits + + + align:start position:0% +is 64 bits +right and we assume that the word size + + align:start position:0% +right and we assume that the word size + + + align:start position:0% +right and we assume that the word size +is at least log + + align:start position:0% +is at least log + + + align:start position:0% +is at least log +in the num the size of your input so + + align:start position:0% +in the num the size of your input so + + + align:start position:0% +in the num the size of your input so +that you can address the input + + align:start position:0% +that you can address the input + + + align:start position:0% +that you can address the input +right right so for your purposes on your + + align:start position:0% +right right so for your purposes on your + + + align:start position:0% +right right so for your purposes on your +computer + + align:start position:0% +computer + + + align:start position:0% +computer +log n is going to be no more than 64 + + align:start position:0% +log n is going to be no more than 64 + + + align:start position:0% +log n is going to be no more than 64 +which means you get a maybe a 50 times + + align:start position:0% +which means you get a maybe a 50 times + + + align:start position:0% +which means you get a maybe a 50 times +overhead or you know for smaller + + align:start position:0% +overhead or you know for smaller + + + align:start position:0% +overhead or you know for smaller +instances it could be more like 10 right + + align:start position:0% +instances it could be more like 10 right + + + align:start position:0% +instances it could be more like 10 right +if you've got like + + align:start position:0% +if you've got like + + + align:start position:0% +if you've got like +a thousand things that you're working on + + align:start position:0% +a thousand things that you're working on + + + align:start position:0% +a thousand things that you're working on +right it's not that bad + + align:start position:0% +right it's not that bad + + + align:start position:0% +right it's not that bad +right it's a constant it's not a + + align:start position:0% +right it's a constant it's not a + + + align:start position:0% +right it's a constant it's not a +constant factor for theory purposes + + align:start position:0% +constant factor for theory purposes + + + align:start position:0% +constant factor for theory purposes +but for your purposes log n is much + + align:start position:0% +but for your purposes log n is much + + + align:start position:0% +but for your purposes log n is much +better than a than a polynomial factor + + align:start position:0% +better than a than a polynomial factor + + + align:start position:0% +better than a than a polynomial factor +right another factor of n okay so + + align:start position:0% +right another factor of n okay so + + + align:start position:0% +right another factor of n okay so +uh you've seen all the code + + align:start position:0% +uh you've seen all the code + + + align:start position:0% +uh you've seen all the code +you've seen implementations of all of + + align:start position:0% +you've seen implementations of all of + + + align:start position:0% +you've seen implementations of all of +these set and sequence interfaces right + + align:start position:0% +these set and sequence interfaces right + + + align:start position:0% +these set and sequence interfaces right +so i went ahead and wrote a little i + + align:start position:0% +so i went ahead and wrote a little i + + + align:start position:0% +so i went ahead and wrote a little i +compiled all of that code from your + + align:start position:0% +compiled all of that code from your + + + align:start position:0% +compiled all of that code from your +recitation notes of all of the different + + align:start position:0% +recitation notes of all of the different + + + align:start position:0% +recitation notes of all of the different +interface implementations and what i did + + align:start position:0% +interface implementations and what i did + + + align:start position:0% +interface implementations and what i did +was i + + align:start position:0% +was i + + + align:start position:0% +was i +wrote a little test program to see how + + align:start position:0% +wrote a little test program to see how + + + align:start position:0% +wrote a little test program to see how +they ran + + align:start position:0% +they ran + + + align:start position:0% +they ran +on a real machine right so i have a + + align:start position:0% +on a real machine right so i have a + + + align:start position:0% +on a real machine right so i have a +little + + align:start position:0% +little + + + align:start position:0% +little +test code here um right so i have a + + align:start position:0% +test code here um right so i have a + + + align:start position:0% +test code here um right so i have a +little folder + + align:start position:0% +little folder + + + align:start position:0% +little folder +that lists you know an array + + align:start position:0% +that lists you know an array + + + align:start position:0% +that lists you know an array +implementing a sequence a binary tree + + align:start position:0% +implementing a sequence a binary tree + + + align:start position:0% +implementing a sequence a binary tree +implementing a sequence a dynamic array + + align:start position:0% +implementing a sequence a dynamic array + + + align:start position:0% +implementing a sequence a dynamic array +implementing + + align:start position:0% +implementing + + + align:start position:0% +implementing +all these kinds of things right then set + + align:start position:0% +all these kinds of things right then set + + + align:start position:0% +all these kinds of things right then set +things a sorted array being a set + + align:start position:0% +things a sorted array being a set + + + align:start position:0% +things a sorted array being a set +and a binary tree and a hash table right + + align:start position:0% +and a binary tree and a hash table right + + + align:start position:0% +and a binary tree and a hash table right +these are our implementations i'm not + + align:start position:0% +these are our implementations i'm not + + + align:start position:0% +these are our implementations i'm not +using + + align:start position:0% +using + + + align:start position:0% +using +python dictionaries for hash tables i'm + + align:start position:0% +python dictionaries for hash tables i'm + + + align:start position:0% +python dictionaries for hash tables i'm +using the implementations that are in + + align:start position:0% +using the implementations that are in + + + align:start position:0% +using the implementations that are in +your + + align:start position:0% +your + + + align:start position:0% +your +restation and i'm going to run this + + align:start position:0% +restation and i'm going to run this + + + align:start position:0% +restation and i'm going to run this +little test efficiency + + align:start position:0% +little test efficiency + + + align:start position:0% +little test efficiency +python code that basically is just gonna + + align:start position:0% +python code that basically is just gonna + + + align:start position:0% +python code that basically is just gonna +for each one it's gonna do a bunch of + + align:start position:0% +for each one it's gonna do a bunch of + + + align:start position:0% +for each one it's gonna do a bunch of +these different operations + + align:start position:0% +these different operations + + + align:start position:0% +these different operations +and measure to see how much time it took + + align:start position:0% +and measure to see how much time it took + + + align:start position:0% +and measure to see how much time it took +right i'm just logging how much time it + + align:start position:0% +right i'm just logging how much time it + + + align:start position:0% +right i'm just logging how much time it +took it's not an asymptotic analysis but + + align:start position:0% +took it's not an asymptotic analysis but + + + align:start position:0% +took it's not an asymptotic analysis but +you know hopefully we see some + + align:start position:0% +you know hopefully we see some + + + align:start position:0% +you know hopefully we see some +separation yeah + + align:start position:0% +separation yeah + + + align:start position:0% +separation yeah +so i'm going to press that it runs a + + align:start position:0% +so i'm going to press that it runs a + + + align:start position:0% +so i'm going to press that it runs a +bunch of tests so let's take a look + + align:start position:0% +bunch of tests so let's take a look + + + align:start position:0% +bunch of tests so let's take a look +uh okay so i got a bunch of sequence + + align:start position:0% +uh okay so i got a bunch of sequence + + + align:start position:0% +uh okay so i got a bunch of sequence +operations right we got build set at get + + align:start position:0% +operations right we got build set at get + + + align:start position:0% +operations right we got build set at get +at insert delete + + align:start position:0% +at insert delete + + + align:start position:0% +at insert delete +at the various places right and i'm + + align:start position:0% +at the various places right and i'm + + + align:start position:0% +at the various places right and i'm +giving these are the actual timings to + + align:start position:0% +giving these are the actual timings to + + + align:start position:0% +giving these are the actual timings to +some scale + + align:start position:0% +some scale + + + align:start position:0% +some scale +right to some resolution that i had for + + align:start position:0% +right to some resolution that i had for + + + align:start position:0% +right to some resolution that i had for +these data structures + + align:start position:0% +these data structures + + + align:start position:0% +these data structures +and you can see build actually build + + align:start position:0% +and you can see build actually build + + + align:start position:0% +and you can see build actually build +on this machine just allocating some + + align:start position:0% +on this machine just allocating some + + + align:start position:0% +on this machine just allocating some +array and clearing it is a really + + align:start position:0% +array and clearing it is a really + + + align:start position:0% +array and clearing it is a really +efficient thing that's python's going to + + align:start position:0% +efficient thing that's python's going to + + + align:start position:0% +efficient thing that's python's going to +do for me + + align:start position:0% +do for me + + + align:start position:0% +do for me +and so that's actually it's miss + + align:start position:0% +and so that's actually it's miss + + + align:start position:0% +and so that's actually it's miss +labeling that as log n right + + align:start position:0% +labeling that as log n right + + + align:start position:0% +labeling that as log n right +uh but uh you know these other things + + align:start position:0% +uh but uh you know these other things + + + align:start position:0% +uh but uh you know these other things +get out and set act + + align:start position:0% +get out and set act + + + align:start position:0% +get out and set act +really really fast right that's constant + + align:start position:0% +really really fast right that's constant + + + align:start position:0% +really really fast right that's constant +time and then these other things i + + align:start position:0% +time and then these other things i + + + align:start position:0% +time and then these other things i +essentially have + + align:start position:0% +essentially have + + + align:start position:0% +essentially have +can't do better than loop through the + + align:start position:0% +can't do better than loop through the + + + align:start position:0% +can't do better than loop through the +thing and so it takes linear time + + align:start position:0% +thing and so it takes linear time + + + align:start position:0% +thing and so it takes linear time +and again sequence uh stuff + + align:start position:0% +and again sequence uh stuff + + + align:start position:0% +and again sequence uh stuff +setting at and getting at is slow but + + align:start position:0% +setting at and getting at is slow but + + + align:start position:0% +setting at and getting at is slow but +deleting + + align:start position:0% +deleting + + + align:start position:0% +deleting +and removing from the first thing i'm + + align:start position:0% +and removing from the first thing i'm + + + align:start position:0% +and removing from the first thing i'm +just re-linking the pointer right + + align:start position:0% +just re-linking the pointer right + + + align:start position:0% +just re-linking the pointer right +dynamic arrays again set at get ad is + + align:start position:0% +dynamic arrays again set at get ad is + + + align:start position:0% +dynamic arrays again set at get ad is +fast because it's just + + align:start position:0% +fast because it's just + + + align:start position:0% +fast because it's just +dynamic it's just regular arrays and + + align:start position:0% +dynamic it's just regular arrays and + + + align:start position:0% +dynamic it's just regular arrays and +then + + align:start position:0% +then + + + align:start position:0% +then +inserting and deleting last that's + + align:start position:0% +inserting and deleting last that's + + + align:start position:0% +inserting and deleting last that's +getting the essentially constant time + + align:start position:0% +getting the essentially constant time + + + align:start position:0% +getting the essentially constant time +now i'm actually when i'm running these + + align:start position:0% +now i'm actually when i'm running these + + + align:start position:0% +now i'm actually when i'm running these +tests to deal with averages + + align:start position:0% +tests to deal with averages + + + align:start position:0% +tests to deal with averages +i'm actually running these things a lot + + align:start position:0% +i'm actually running these things a lot + + + align:start position:0% +i'm actually running these things a lot +of times and testing their performance + + align:start position:0% +of times and testing their performance + + + align:start position:0% +of times and testing their performance +and so i'm not seeing the worst case + + align:start position:0% +and so i'm not seeing the worst case + + + align:start position:0% +and so i'm not seeing the worst case +happen here + + align:start position:0% +happen here + + + align:start position:0% +happen here +right i'm averaging over all of the + + align:start position:0% +right i'm averaging over all of the + + + align:start position:0% +right i'm averaging over all of the +things which is exactly what + + align:start position:0% +things which is exactly what + + + align:start position:0% +things which is exactly what +amortization + + align:start position:0% +amortization + + + align:start position:0% +amortization +means and so that's why i'm getting good + + align:start position:0% +means and so that's why i'm getting good + + + align:start position:0% +means and so that's why i'm getting good +performance here + + align:start position:0% +performance here + + + align:start position:0% +performance here +uh a hash table again + + align:start position:0% +uh a hash table again + + + align:start position:0% +uh a hash table again +really uh oh so this is what we talked + + align:start position:0% +really uh oh so this is what we talked + + + align:start position:0% +really uh oh so this is what we talked +about + + align:start position:0% +about + + + align:start position:0% +about +in problem session last week right + + align:start position:0% +in problem session last week right + + + align:start position:0% +in problem session last week right +implementing a uh kind of a double-ended + + align:start position:0% +implementing a uh kind of a double-ended + + + align:start position:0% +implementing a uh kind of a double-ended +queue with a hash table + + align:start position:0% +queue with a hash table + + + align:start position:0% +queue with a hash table +uh this is that implementation i just + + align:start position:0% +uh this is that implementation i just + + + align:start position:0% +uh this is that implementation i just +want to show it to you but it's actually + + align:start position:0% +want to show it to you but it's actually + + + align:start position:0% +want to show it to you but it's actually +pretty good this is what javascript uses + + align:start position:0% +pretty good this is what javascript uses + + + align:start position:0% +pretty good this is what javascript uses +for arrays + + align:start position:0% +for arrays + + + align:start position:0% +for arrays +and then a binary sequence represents a + + align:start position:0% +and then a binary sequence represents a + + + align:start position:0% +and then a binary sequence represents a +binary tree + + align:start position:0% +binary tree + + + align:start position:0% +binary tree +right a balanced binary tree this is our + + align:start position:0% +right a balanced binary tree this is our + + + align:start position:0% +right a balanced binary tree this is our +avl code that i had + + align:start position:0% +avl code that i had + + + align:start position:0% +avl code that i had +and you know all the other things have + + align:start position:0% +and you know all the other things have + + + align:start position:0% +and you know all the other things have +been really pretty bad at insert at and + + align:start position:0% +been really pretty bad at insert at and + + + align:start position:0% +been really pretty bad at insert at and +delete at + + align:start position:0% +delete at + + + align:start position:0% +delete at +but this one does comparable to all the + + align:start position:0% +but this one does comparable to all the + + + align:start position:0% +but this one does comparable to all the +other things now you see these are a + + align:start position:0% +other things now you see these are a + + + align:start position:0% +other things now you see these are a +little bit more + + align:start position:0% +little bit more + + + align:start position:0% +little bit more +you know machine cycles than the other + + align:start position:0% +you know machine cycles than the other + + + align:start position:0% +you know machine cycles than the other +things but + + align:start position:0% +things but + + + align:start position:0% +things but +you know not so bad actually uh and then + + align:start position:0% +you know not so bad actually uh and then + + + align:start position:0% +you know not so bad actually uh and then +on the set side of things + + align:start position:0% +on the set side of things + + + align:start position:0% +on the set side of things +again we had a sorted array uh sorry + + align:start position:0% +again we had a sorted array uh sorry + + + align:start position:0% +again we had a sorted array uh sorry +this is a set from + + align:start position:0% +this is a set from + + + align:start position:0% +this is a set from +an array basically it's an unsorted + + align:start position:0% +an array basically it's an unsorted + + + align:start position:0% +an array basically it's an unsorted +array i'm just looking for all the + + align:start position:0% +array i'm just looking for all the + + + align:start position:0% +array i'm just looking for all the +things that's very bad times + + align:start position:0% +things that's very bad times + + + align:start position:0% +things that's very bad times +sorted array does these fine operations + + align:start position:0% +sorted array does these fine operations + + + align:start position:0% +sorted array does these fine operations +great but inserting deleting is + + align:start position:0% +great but inserting deleting is + + + align:start position:0% +great but inserting deleting is +poor right that's why we need binary + + align:start position:0% +poor right that's why we need binary + + + align:start position:0% +poor right that's why we need binary +trees + + align:start position:0% +trees + + + align:start position:0% +trees +hash tables you know get good kind of + + align:start position:0% +hash tables you know get good kind of + + + align:start position:0% +hash tables you know get good kind of +dictionary operations but really bad + + align:start position:0% +dictionary operations but really bad + + + align:start position:0% +dictionary operations but really bad +order operations right + + align:start position:0% +order operations right + + + align:start position:0% +order operations right +and then the binary search tree right a + + align:start position:0% +and then the binary search tree right a + + + align:start position:0% +and then the binary search tree right a +set binary tree + + align:start position:0% +set binary tree + + + align:start position:0% +set binary tree +uh again does quite good on all of these + + align:start position:0% +uh again does quite good on all of these + + + align:start position:0% +uh again does quite good on all of these +things + + align:start position:0% +things + + + align:start position:0% +things +in fact it's getting really quite good + + align:start position:0% +in fact it's getting really quite good + + + align:start position:0% +in fact it's getting really quite good +it's getting better for some reason than + + align:start position:0% +it's getting better for some reason than + + + align:start position:0% +it's getting better for some reason than +these the sorted array even did + + align:start position:0% +these the sorted array even did + + + align:start position:0% +these the sorted array even did +so uh i don't know why + + align:start position:0% +so uh i don't know why + + + align:start position:0% +so uh i don't know why +our implementations are not optimized at + + align:start position:0% +our implementations are not optimized at + + + align:start position:0% +our implementations are not optimized at +all but it does pretty well + + align:start position:0% +all but it does pretty well + + + align:start position:0% +all but it does pretty well +asymptotically yep um could you explain + + align:start position:0% +asymptotically yep um could you explain + + + align:start position:0% +asymptotically yep um could you explain +again why the + + align:start position:0% +again why the + + + align:start position:0% +again why the +in the first day of surgery was blog + + align:start position:0% +in the first day of surgery was blog + + + align:start position:0% +in the first day of surgery was blog +this is just labeled based off the + + align:start position:0% +this is just labeled based off the + + + align:start position:0% +this is just labeled based off the +timings right + + align:start position:0% +timings right + + + align:start position:0% +timings right +it happens to be that probably there's a + + align:start position:0% +it happens to be that probably there's a + + + align:start position:0% +it happens to be that probably there's a +c intrinsic underneath python + + align:start position:0% +c intrinsic underneath python + + + align:start position:0% +c intrinsic underneath python +that allocates this thing and so it does + + align:start position:0% +that allocates this thing and so it does + + + align:start position:0% +that allocates this thing and so it does +it really fast and so my + + align:start position:0% +it really fast and so my + + + align:start position:0% +it really fast and so my +program that's looking at these numbers + + align:start position:0% +program that's looking at these numbers + + + align:start position:0% +program that's looking at these numbers +and trying to guess what the asymptotic + + align:start position:0% +and trying to guess what the asymptotic + + + align:start position:0% +and trying to guess what the asymptotic +running time is + + align:start position:0% +running time is + + + align:start position:0% +running time is +these are just labels based on these + + align:start position:0% +these are just labels based on these + + + align:start position:0% +these are just labels based on these +things ranges + + align:start position:0% +things ranges + + + align:start position:0% +things ranges +i just it's it's mis characterizing + + align:start position:0% +i just it's it's mis characterizing + + + align:start position:0% +i just it's it's mis characterizing +actually building it at any time + + align:start position:0% +actually building it at any time + + + align:start position:0% +actually building it at any time +yeah well i mean in in actuality if it + + align:start position:0% +yeah well i mean in in actuality if it + + + align:start position:0% +yeah well i mean in in actuality if it +was + + align:start position:0% +was + + + align:start position:0% +was +c code right if all of this stuff was in + + align:start position:0% +c code right if all of this stuff was in + + + align:start position:0% +c code right if all of this stuff was in +c + + align:start position:0% +c + + + align:start position:0% +c +probably we'd see that that bar be + + align:start position:0% +probably we'd see that that bar be + + + align:start position:0% +probably we'd see that that bar be +longer because it's actually having to + + align:start position:0% +longer because it's actually having to + + + align:start position:0% +longer because it's actually having to +go through and touch all that memory + + align:start position:0% +go through and touch all that memory + + + align:start position:0% +go through and touch all that memory +it's still doing that here but all the + + align:start position:0% +it's still doing that here but all the + + + align:start position:0% +it's still doing that here but all the +python stuff is super crafty right it's + + align:start position:0% +python stuff is super crafty right it's + + + align:start position:0% +python stuff is super crafty right it's +like + + align:start position:0% +like + + + align:start position:0% +like +100 times slower than anything that c + + align:start position:0% +100 times slower than anything that c + + + align:start position:0% +100 times slower than anything that c +does and so + + align:start position:0% +does and so + + + align:start position:0% +does and so +you're seeing that that disparity here + + align:start position:0% +you're seeing that that disparity here + + + align:start position:0% +you're seeing that that disparity here +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +okay so i just wanted to show you that + + align:start position:0% +okay so i just wanted to show you that + + + align:start position:0% +okay so i just wanted to show you that +uh we might release this + + align:start position:0% +uh we might release this + + + align:start position:0% +uh we might release this +for you to play around with but i just + + align:start position:0% +for you to play around with but i just + + + align:start position:0% +for you to play around with but i just +wanted to + + align:start position:0% +wanted to + + + align:start position:0% +wanted to +give you a taste of that okay any + + align:start position:0% +give you a taste of that okay any + + + align:start position:0% +give you a taste of that okay any +questions + + align:start position:0% +questions + + + align:start position:0% +questions +you move on how do i turn this off + + align:start position:0% +you move on how do i turn this off + + + align:start position:0% +you move on how do i turn this off +up and off + + align:start position:0% +up and off + + + align:start position:0% +up and off +shut down + + align:start position:0% +shut down + + + align:start position:0% +shut down +[Music] + + align:start position:0% + + + + align:start position:0% + +yes okay so what + + align:start position:0% + + + + align:start position:0% + +all right so moving on to problems + + align:start position:0% +all right so moving on to problems + + + align:start position:0% +all right so moving on to problems +working some problems uh so you have + + align:start position:0% +working some problems uh so you have + + + align:start position:0% +working some problems uh so you have +your set of problems here uh the first + + align:start position:0% +your set of problems here uh the first + + + align:start position:0% +your set of problems here uh the first +one is we're going to look at a sequence + + align:start position:0% +one is we're going to look at a sequence + + + align:start position:0% +one is we're going to look at a sequence +avl tree right this is a sequence abl + + align:start position:0% +avl tree right this is a sequence abl + + + align:start position:0% +avl tree right this is a sequence abl +tree how do i know that + + align:start position:0% + + + + align:start position:0% + +you don't necessarily but these things + + align:start position:0% +you don't necessarily but these things + + + align:start position:0% +you don't necessarily but these things +are certainly not + + align:start position:0% +are certainly not + + + align:start position:0% +are certainly not +in sorted order of the things i'm + + align:start position:0% +in sorted order of the things i'm + + + align:start position:0% +in sorted order of the things i'm +storied in them + + align:start position:0% +storied in them + + + align:start position:0% +storied in them +right so it better not be a set avl tree + + align:start position:0% +right so it better not be a set avl tree + + + align:start position:0% +right so it better not be a set avl tree +right is it an avl tree is it balanced + + align:start position:0% +right is it an avl tree is it balanced + + + align:start position:0% +right is it an avl tree is it balanced +height balanced + + align:start position:0% +height balanced + + + align:start position:0% +height balanced +yeah yeah basically actually if you take + + align:start position:0% +yeah yeah basically actually if you take + + + align:start position:0% +yeah yeah basically actually if you take +compute the size of each subtree + + align:start position:0% +compute the size of each subtree + + + align:start position:0% +compute the size of each subtree +right the left and right sub-trees on + + align:start position:0% +right the left and right sub-trees on + + + align:start position:0% +right the left and right sub-trees on +all these you can confirm for yourself + + align:start position:0% +all these you can confirm for yourself + + + align:start position:0% +all these you can confirm for yourself +are balanced right there they're + + align:start position:0% +are balanced right there they're + + + align:start position:0% +are balanced right there they're +within plus or minus one of each other + + align:start position:0% +within plus or minus one of each other + + + align:start position:0% +within plus or minus one of each other +actually this is about as far away from + + align:start position:0% +actually this is about as far away from + + + align:start position:0% +actually this is about as far away from +balance as you could get + + align:start position:0% +balance as you could get + + + align:start position:0% +balance as you could get +for this many nodes uh while still + + align:start position:0% +for this many nodes uh while still + + + align:start position:0% +for this many nodes uh while still +maintaining hype balance maintaining avl + + align:start position:0% +maintaining hype balance maintaining avl + + + align:start position:0% +maintaining hype balance maintaining avl +property + + align:start position:0% +property + + + align:start position:0% +property +which is why this is an instructive + + align:start position:0% +which is why this is an instructive + + + align:start position:0% +which is why this is an instructive +example it's kind of at the limit + + align:start position:0% +example it's kind of at the limit + + + align:start position:0% +example it's kind of at the limit +okay and uh + + align:start position:0% +okay and uh + + + align:start position:0% +okay and uh +what am i going to do this is a see + + align:start position:0% +what am i going to do this is a see + + + align:start position:0% +what am i going to do this is a see +what's missing in this picture + + align:start position:0% +what's missing in this picture + + + align:start position:0% +what's missing in this picture +if i'm claiming this is a sequence avl + + align:start position:0% +if i'm claiming this is a sequence avl + + + align:start position:0% +if i'm claiming this is a sequence avl +tree + + align:start position:0% + + + + align:start position:0% + +any ideas what's missing + + align:start position:0% +any ideas what's missing + + + align:start position:0% +any ideas what's missing +what is the sequence avl tree store that + + align:start position:0% +what is the sequence avl tree store that + + + align:start position:0% +what is the sequence avl tree store that +i'm not showing in this picture + + align:start position:0% +i'm not showing in this picture + + + align:start position:0% +i'm not showing in this picture +what counts and + + align:start position:0% + + + + align:start position:0% + +it's a sequence avl tree heights + + align:start position:0% +it's a sequence avl tree heights + + + align:start position:0% +it's a sequence avl tree heights +right so it's a sequence avl trees + + align:start position:0% +right so it's a sequence avl trees + + + align:start position:0% +right so it's a sequence avl trees +different than set available trees are + + align:start position:0% +different than set available trees are + + + align:start position:0% +different than set available trees are +augmented by two things right because + + align:start position:0% +augmented by two things right because + + + align:start position:0% +augmented by two things right because +i need to be maintaining balance during + + align:start position:0% +i need to be maintaining balance during + + + align:start position:0% +i need to be maintaining balance during +rotations and so i need to store heights + + align:start position:0% +rotations and so i need to store heights + + + align:start position:0% +rotations and so i need to store heights +i need to be able to tell what the + + align:start position:0% +i need to be able to tell what the + + + align:start position:0% +i need to be able to tell what the +heights of these sub trees are in + + align:start position:0% +heights of these sub trees are in + + + align:start position:0% +heights of these sub trees are in +constant time when i'm + + align:start position:0% +constant time when i'm + + + align:start position:0% +constant time when i'm +walking up the tree fixing things and + + align:start position:0% +walking up the tree fixing things and + + + align:start position:0% +walking up the tree fixing things and +the sequence + + align:start position:0% +the sequence + + + align:start position:0% +the sequence +requires me to store their subtree the + + align:start position:0% +requires me to store their subtree the + + + align:start position:0% +requires me to store their subtree the +numbers there + + align:start position:0% +numbers there + + + align:start position:0% +numbers there +right so i don't know i'm not going to + + align:start position:0% +right so i don't know i'm not going to + + + align:start position:0% +right so i don't know i'm not going to +draw it for all of these things but how + + align:start position:0% +draw it for all of these things but how + + + align:start position:0% +draw it for all of these things but how +about for number 4 + + align:start position:0% +about for number 4 + + + align:start position:0% +about for number 4 +what's its height + + align:start position:0% + + + + align:start position:0% + +one two three that's the longest path + + align:start position:0% +one two three that's the longest path + + + align:start position:0% +one two three that's the longest path +from the sub the root subtree of that so + + align:start position:0% +from the sub the root subtree of that so + + + align:start position:0% +from the sub the root subtree of that so +this is you know + + align:start position:0% +this is you know + + + align:start position:0% +this is you know +height equals uh three that came from + + align:start position:0% +height equals uh three that came from + + + align:start position:0% +height equals uh three that came from +height equals two and height is one let + + align:start position:0% +height equals two and height is one let + + + align:start position:0% +height equals two and height is one let +everyone see that + + align:start position:0% +everyone see that + + + align:start position:0% +everyone see that +yeah and then the size here how big is + + align:start position:0% +yeah and then the size here how big is + + + align:start position:0% +yeah and then the size here how big is +that that's + + align:start position:0% +that that's + + + align:start position:0% +that that's +one two three four five six seven right + + align:start position:0% +one two three four five six seven right + + + align:start position:0% +one two three four five six seven right +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +i'm gonna put size equals seven + + align:start position:0% +i'm gonna put size equals seven + + + align:start position:0% +i'm gonna put size equals seven +here right and that's coming from this + + align:start position:0% +here right and that's coming from this + + + align:start position:0% +here right and that's coming from this +guy one two three + + align:start position:0% +guy one two three + + + align:start position:0% +guy one two three +four and this guy + + align:start position:0% +four and this guy + + + align:start position:0% +four and this guy +is two + + align:start position:0% + + + + align:start position:0% + +right so how do i compute the subtree + + align:start position:0% +right so how do i compute the subtree + + + align:start position:0% +right so how do i compute the subtree +size + + align:start position:0% +size + + + align:start position:0% +size +it's my left subtree size plus my right + + align:start position:0% +it's my left subtree size plus my right + + + align:start position:0% +it's my left subtree size plus my right +subtree size plus 1 + + align:start position:0% +subtree size plus 1 + + + align:start position:0% +subtree size plus 1 +right and my height is taking the max of + + align:start position:0% +right and my height is taking the max of + + + align:start position:0% +right and my height is taking the max of +the 2 plus 1 right + + align:start position:0% +the 2 plus 1 right + + + align:start position:0% +the 2 plus 1 right +all right so we did all that yesterday + + align:start position:0% +all right so we did all that yesterday + + + align:start position:0% +all right so we did all that yesterday +so i'm + + align:start position:0% +so i'm + + + align:start position:0% +so i'm +just labeling these things and what i'm + + align:start position:0% +just labeling these things and what i'm + + + align:start position:0% +just labeling these things and what i'm +asking of you + + align:start position:0% +asking of you + + + align:start position:0% +asking of you +is to perform a delete operation + + align:start position:0% +is to perform a delete operation + + + align:start position:0% +is to perform a delete operation +is a sequence uh tree so i'm + + align:start position:0% +is a sequence uh tree so i'm + + + align:start position:0% +is a sequence uh tree so i'm +i'm finding things by their index in the + + align:start position:0% +i'm finding things by their index in the + + + align:start position:0% +i'm finding things by their index in the +tree right so i'm going to ask you to + + align:start position:0% +tree right so i'm going to ask you to + + + align:start position:0% +tree right so i'm going to ask you to +delete the eighth thing + + align:start position:0% +delete the eighth thing + + + align:start position:0% +delete the eighth thing +in my sequence okay so what is the + + align:start position:0% +in my sequence okay so what is the + + + align:start position:0% +in my sequence okay so what is the +eighth thing in my sequence + + align:start position:0% + + + + align:start position:0% + +yeah all right just to clarify is not + + align:start position:0% +yeah all right just to clarify is not + + + align:start position:0% +yeah all right just to clarify is not +delete + + align:start position:0% +delete + + + align:start position:0% +delete +a number correct well delete at + + align:start position:0% +a number correct well delete at + + + align:start position:0% +a number correct well delete at +eight do you see that it's a sequence + + align:start position:0% +eight do you see that it's a sequence + + + align:start position:0% +eight do you see that it's a sequence +operation + + align:start position:0% +operation + + + align:start position:0% +operation +yeah so this is very important that you + + align:start position:0% +yeah so this is very important that you + + + align:start position:0% +yeah so this is very important that you +differentiate between + + align:start position:0% +differentiate between + + + align:start position:0% +differentiate between +sequence and set semantics right if i'm + + align:start position:0% +sequence and set semantics right if i'm + + + align:start position:0% +sequence and set semantics right if i'm +dealing with the sequence + + align:start position:0% +dealing with the sequence + + + align:start position:0% +dealing with the sequence +i better not be looking up intrinsic + + align:start position:0% +i better not be looking up intrinsic + + + align:start position:0% +i better not be looking up intrinsic +things on this data structure right + + align:start position:0% +things on this data structure right + + + align:start position:0% +things on this data structure right +because it's not an intrinsic data + + align:start position:0% +because it's not an intrinsic data + + + align:start position:0% +because it's not an intrinsic data +structure it doesn't support that so if + + align:start position:0% +structure it doesn't support that so if + + + align:start position:0% +structure it doesn't support that so if +i + + align:start position:0% +i + + + align:start position:0% +i +wanted to support find + + align:start position:0% +wanted to support find + + + align:start position:0% +wanted to support find +the say the index of key 8 + + align:start position:0% +the say the index of key 8 + + + align:start position:0% +the say the index of key 8 +or something like that right then all i + + align:start position:0% +or something like that right then all i + + + align:start position:0% +or something like that right then all i +could do is it's similar to like an + + align:start position:0% +could do is it's similar to like an + + + align:start position:0% +could do is it's similar to like an +array i would just have to loop through + + align:start position:0% +array i would just have to loop through + + + align:start position:0% +array i would just have to loop through +the whole sequence and tell me if the + + align:start position:0% +the whole sequence and tell me if the + + + align:start position:0% +the whole sequence and tell me if the +thing's in there + + align:start position:0% +thing's in there + + + align:start position:0% +thing's in there +right can't really do better than linear + + align:start position:0% +right can't really do better than linear + + + align:start position:0% +right can't really do better than linear +time this data structure is not designed + + align:start position:0% +time this data structure is not designed + + + align:start position:0% +time this data structure is not designed +for that what is it designed for it's + + align:start position:0% +for that what is it designed for it's + + + align:start position:0% +for that what is it designed for it's +designed to find things by their index + + align:start position:0% +designed to find things by their index + + + align:start position:0% +designed to find things by their index +in the sequence right so uh + + align:start position:0% +in the sequence right so uh + + + align:start position:0% +in the sequence right so uh +how do i find the eighth index + + align:start position:0% +how do i find the eighth index + + + align:start position:0% +how do i find the eighth index +well i mean i'm looking at the tree and + + align:start position:0% +well i mean i'm looking at the tree and + + + align:start position:0% +well i mean i'm looking at the tree and +i can just + + align:start position:0% +i can just + + + align:start position:0% +i can just +you know count along the in order + + align:start position:0% +you know count along the in order + + + align:start position:0% +you know count along the in order +traversal what's the inorder traversal + + align:start position:0% +traversal what's the inorder traversal + + + align:start position:0% +traversal what's the inorder traversal +right zero one two + + align:start position:0% +right zero one two + + + align:start position:0% +right zero one two +three four five six seven eight okay + + align:start position:0% +three four five six seven eight okay + + + align:start position:0% +three four five six seven eight okay +found eight but what does a sequence avl + + align:start position:0% +found eight but what does a sequence avl + + + align:start position:0% +found eight but what does a sequence avl +tree do + + align:start position:0% +tree do + + + align:start position:0% +tree do +right it i'm storing subtree sizes + + align:start position:0% +right it i'm storing subtree sizes + + + align:start position:0% +right it i'm storing subtree sizes +and when i'm here i don't know what + + align:start position:0% +and when i'm here i don't know what + + + align:start position:0% +and when i'm here i don't know what +index i'm at right + + align:start position:0% +index i'm at right + + + align:start position:0% +index i'm at right +how can i find out what index i'm at + + align:start position:0% +how can i find out what index i'm at + + + align:start position:0% +how can i find out what index i'm at +from the root i look at my left sub tree + + align:start position:0% +from the root i look at my left sub tree + + + align:start position:0% +from the root i look at my left sub tree +see how many it is + + align:start position:0% +see how many it is + + + align:start position:0% +see how many it is +right there are seven things here + + align:start position:0% +right there are seven things here + + + align:start position:0% +right there are seven things here +uh one two three four five seven + + align:start position:0% +uh one two three four five seven + + + align:start position:0% +uh one two three four five seven +eight right yeah because i'm looking for + + align:start position:0% +eight right yeah because i'm looking for + + + align:start position:0% +eight right yeah because i'm looking for +the ninth item + + align:start position:0% +the ninth item + + + align:start position:0% +the ninth item +by index eight right so this is saying + + align:start position:0% +by index eight right so this is saying + + + align:start position:0% +by index eight right so this is saying +that i'm the eighth item + + align:start position:0% +that i'm the eighth item + + + align:start position:0% +that i'm the eighth item +right and the guy at index seven + + align:start position:0% +right and the guy at index seven + + + align:start position:0% +right and the guy at index seven +does that make sense because i'm looking + + align:start position:0% +does that make sense because i'm looking + + + align:start position:0% +does that make sense because i'm looking +at the subtree size here + + align:start position:0% +at the subtree size here + + + align:start position:0% +at the subtree size here +so what do i know i know that the index + + align:start position:0% +so what do i know i know that the index + + + align:start position:0% +so what do i know i know that the index +that i'm looking for is to my right + + align:start position:0% +that i'm looking for is to my right + + + align:start position:0% +that i'm looking for is to my right +right so i go down over here + + align:start position:0% +right so i go down over here + + + align:start position:0% +right so i go down over here +and i happen to know what am i what + + align:start position:0% +and i happen to know what am i what + + + align:start position:0% +and i happen to know what am i what +index of + + align:start position:0% +index of + + + align:start position:0% +index of +of am i looking for in this subtree + + align:start position:0% +of am i looking for in this subtree + + + align:start position:0% +of am i looking for in this subtree +zero right i want the first thing in + + align:start position:0% +zero right i want the first thing in + + + align:start position:0% +zero right i want the first thing in +this sub tree + + align:start position:0% +this sub tree + + + align:start position:0% +this sub tree +my search index has changed now right + + align:start position:0% +my search index has changed now right + + + align:start position:0% +my search index has changed now right +because i + + align:start position:0% +because i + + + align:start position:0% +because i +essentially dealt with all of those + + align:start position:0% +essentially dealt with all of those + + + align:start position:0% +essentially dealt with all of those +eight items + + align:start position:0% +eight items + + + align:start position:0% +eight items +right so here i'm looking for the zero + + align:start position:0% +right so here i'm looking for the zero + + + align:start position:0% +right so here i'm looking for the zero +thing in my index + + align:start position:0% +thing in my index + + + align:start position:0% +thing in my index +i look to my left if i didn't have a + + align:start position:0% +i look to my left if i didn't have a + + + align:start position:0% +i look to my left if i didn't have a +left sub tree i would be the zero thing + + align:start position:0% +left sub tree i would be the zero thing + + + align:start position:0% +left sub tree i would be the zero thing +right and i would return me but there is + + align:start position:0% +right and i would return me but there is + + + align:start position:0% +right and i would return me but there is +stuff in here so i'm looking for the + + align:start position:0% +stuff in here so i'm looking for the + + + align:start position:0% +stuff in here so i'm looking for the +zero thing in here right + + align:start position:0% +zero thing in here right + + + align:start position:0% +zero thing in here right +which is just him and i return it okay + + align:start position:0% +which is just him and i return it okay + + + align:start position:0% +which is just him and i return it okay +and actually what i'm doing is i'm + + align:start position:0% +and actually what i'm doing is i'm + + + align:start position:0% +and actually what i'm doing is i'm +deleting it + + align:start position:0% +deleting it + + + align:start position:0% +deleting it +right so i delete it + + align:start position:0% +right so i delete it + + + align:start position:0% +right so i delete it +yuck what's the problem here + + align:start position:0% + + + + align:start position:0% + +i'm not high balance weird what's not + + align:start position:0% +i'm not high balance weird what's not + + + align:start position:0% +i'm not high balance weird what's not +height balanced here + + align:start position:0% +height balanced here + + + align:start position:0% +height balanced here +um the lug subtree is earth + + align:start position:0% +um the lug subtree is earth + + + align:start position:0% +um the lug subtree is earth +so this guy's not height balance right + + align:start position:0% +so this guy's not height balance right + + + align:start position:0% +so this guy's not height balance right +right + + align:start position:0% +right + + + align:start position:0% +right +this guy's subtree is not height balance + + align:start position:0% +this guy's subtree is not height balance + + + align:start position:0% +this guy's subtree is not height balance +right this guy's two this guy's one + + align:start position:0% +right this guy's two this guy's one + + + align:start position:0% +right this guy's two this guy's one +okay so how do we fix it + + align:start position:0% + + + + align:start position:0% + +we do some rotations right this is + + align:start position:0% +we do some rotations right this is + + + align:start position:0% +we do some rotations right this is +actually the + + align:start position:0% +actually the + + + align:start position:0% +actually the +bad case that with the third bad case + + align:start position:0% +bad case that with the third bad case + + + align:start position:0% +bad case that with the third bad case +that we talked about yesterday + + align:start position:0% +that we talked about yesterday + + + align:start position:0% +that we talked about yesterday +right if i tried to just left rotate + + align:start position:0% +right if i tried to just left rotate + + + align:start position:0% +right if i tried to just left rotate +this + + align:start position:0% +this + + + align:start position:0% +this +guy what would it look like it would put + + align:start position:0% +guy what would it look like it would put + + + align:start position:0% +guy what would it look like it would put +12 here it would put 10 here and 8 would + + align:start position:0% +12 here it would put 10 here and 8 would + + + align:start position:0% +12 here it would put 10 here and 8 would +be attached to that + + align:start position:0% +be attached to that + + + align:start position:0% +be attached to that +now it's height balance wrong in the + + align:start position:0% +now it's height balance wrong in the + + + align:start position:0% +now it's height balance wrong in the +other direction right that's no good + + align:start position:0% +other direction right that's no good + + + align:start position:0% +other direction right that's no good +right so the way to handle this case + + align:start position:0% +right so the way to handle this case + + + align:start position:0% +right so the way to handle this case +where + + align:start position:0% +where + + + align:start position:0% +where +i'm badly skewed to the right + + align:start position:0% +i'm badly skewed to the right + + + align:start position:0% +i'm badly skewed to the right +but my right subtree is badly skew is + + align:start position:0% +but my right subtree is badly skew is + + + align:start position:0% +but my right subtree is badly skew is +skewed to the left + + align:start position:0% +skewed to the left + + + align:start position:0% +skewed to the left +i have to do a rotation here right + + align:start position:0% +i have to do a rotation here right + + + align:start position:0% +i have to do a rotation here right +rotation + + align:start position:0% +rotation + + + align:start position:0% +rotation +and then do a rotation so that's that's + + align:start position:0% +and then do a rotation so that's that's + + + align:start position:0% +and then do a rotation so that's that's +the formula okay + + align:start position:0% +the formula okay + + + align:start position:0% +the formula okay +so here we first do a right rotation at + + align:start position:0% +so here we first do a right rotation at + + + align:start position:0% +so here we first do a right rotation at + + align:start position:0% + + + align:start position:0% +okay which gives me something that looks + + align:start position:0% +okay which gives me something that looks + + + align:start position:0% +okay which gives me something that looks +like + + align:start position:0% + + + + align:start position:0% + +8 10 okay + + align:start position:0% +8 10 okay + + + align:start position:0% +8 10 okay +well obviously this is uh not better + + align:start position:0% +well obviously this is uh not better + + + align:start position:0% +well obviously this is uh not better +than what was before but it's an + + align:start position:0% +than what was before but it's an + + + align:start position:0% +than what was before but it's an +intermediate step so that we can fix it + + align:start position:0% +intermediate step so that we can fix it + + + align:start position:0% +intermediate step so that we can fix it +right + + align:start position:0% +right + + + align:start position:0% +right +we right rotate here and then we left + + align:start position:0% +we right rotate here and then we left + + + align:start position:0% +we right rotate here and then we left +rotate here right + + align:start position:0% +rotate here right + + + align:start position:0% +rotate here right +the default is that we would left rotate + + align:start position:0% +the default is that we would left rotate + + + align:start position:0% +the default is that we would left rotate +here but because this had + + align:start position:0% +here but because this had + + + align:start position:0% +here but because this had +the skew in the wrong direction i need + + align:start position:0% +the skew in the wrong direction i need + + + align:start position:0% +the skew in the wrong direction i need +to + + align:start position:0% +to + + + align:start position:0% +to +right rotate this one first and then we + + align:start position:0% +right rotate this one first and then we + + + align:start position:0% +right rotate this one first and then we +can do it so now i + + align:start position:0% +can do it so now i + + + align:start position:0% +can do it so now i +rotate all of these guys over right + + align:start position:0% +rotate all of these guys over right + + + align:start position:0% +rotate all of these guys over right +and put 12 down here 8 here + + align:start position:0% +and put 12 down here 8 here + + + align:start position:0% +and put 12 down here 8 here +10 here done + + align:start position:0% +10 here done + + + align:start position:0% +10 here done +everyone see that that's what a rotation + + align:start position:0% +everyone see that that's what a rotation + + + align:start position:0% +everyone see that that's what a rotation +looks like + + align:start position:0% +looks like + + + align:start position:0% +looks like +okay it takes a little while to get your + + align:start position:0% +okay it takes a little while to get your + + + align:start position:0% +okay it takes a little while to get your +mind wrapped around + + align:start position:0% +mind wrapped around + + + align:start position:0% +mind wrapped around +what the transformation is but hopefully + + align:start position:0% +what the transformation is but hopefully + + + align:start position:0% +what the transformation is but hopefully +you guys all followed + + align:start position:0% +you guys all followed + + + align:start position:0% +you guys all followed +that transformation there was a little + + align:start position:0% +that transformation there was a little + + + align:start position:0% +that transformation there was a little +magic while i was trying to draw yeah + + align:start position:0% +magic while i was trying to draw yeah + + + align:start position:0% +magic while i was trying to draw yeah +i still don't feel like this tree is + + align:start position:0% +i still don't feel like this tree is + + + align:start position:0% +i still don't feel like this tree is +high balance it's not + + align:start position:0% +high balance it's not + + + align:start position:0% +high balance it's not +good observation why is that this thing + + align:start position:0% +good observation why is that this thing + + + align:start position:0% +good observation why is that this thing +still has height three + + align:start position:0% +still has height three + + + align:start position:0% +still has height three +what is the height of this thing one + + align:start position:0% +what is the height of this thing one + + + align:start position:0% +what is the height of this thing one +right + + align:start position:0% +right + + + align:start position:0% +right +this is height one and actually when i + + align:start position:0% +this is height one and actually when i + + + align:start position:0% +this is height one and actually when i +was doing that rotation + + align:start position:0% +was doing that rotation + + + align:start position:0% +was doing that rotation +i needed to update all these + + align:start position:0% +i needed to update all these + + + align:start position:0% +i needed to update all these +augmentations right + + align:start position:0% +augmentations right + + + align:start position:0% +augmentations right +how which augmentations did i really + + align:start position:0% +how which augmentations did i really + + + align:start position:0% +how which augmentations did i really +need to which subtrees have changed + + align:start position:0% +need to which subtrees have changed + + + align:start position:0% +need to which subtrees have changed +during those things + + align:start position:0% + + + + align:start position:0% + +i don't remember what the thing looked + + align:start position:0% +i don't remember what the thing looked + + + align:start position:0% +i don't remember what the thing looked +like what did the thing look like + + align:start position:0% +like what did the thing look like + + + align:start position:0% +like what did the thing look like +10 10 had eight in its subtree + + align:start position:0% +10 10 had eight in its subtree + + + align:start position:0% +10 10 had eight in its subtree +so its subtree definitely changed right + + align:start position:0% +so its subtree definitely changed right + + + align:start position:0% +so its subtree definitely changed right +eight sub tree changed + + align:start position:0% +eight sub tree changed + + + align:start position:0% +eight sub tree changed +twelve didn't change eventually + + align:start position:0% + + + + align:start position:0% + +okay so there's the case analysis that's + + align:start position:0% +okay so there's the case analysis that's + + + align:start position:0% +okay so there's the case analysis that's +in your lecture notes and was done in + + align:start position:0% +in your lecture notes and was done in + + + align:start position:0% +in your lecture notes and was done in +recitation + + align:start position:0% +recitation + + + align:start position:0% +recitation +right it tells you that these a b + + align:start position:0% +right it tells you that these a b + + + align:start position:0% +right it tells you that these a b +c d kind of sub trees right + + align:start position:0% +c d kind of sub trees right + + + align:start position:0% +c d kind of sub trees right +the ones that could change in these + + align:start position:0% +the ones that could change in these + + + align:start position:0% +the ones that could change in these +things those sub trees don't change + + align:start position:0% +things those sub trees don't change + + + align:start position:0% +things those sub trees don't change +the only sub trees that change during + + align:start position:0% +the only sub trees that change during + + + align:start position:0% +the only sub trees that change during +one of these fixed operations when you + + align:start position:0% +one of these fixed operations when you + + + align:start position:0% +one of these fixed operations when you +do one or two rotations + + align:start position:0% +do one or two rotations + + + align:start position:0% +do one or two rotations +is either two nodes or three nodes that + + align:start position:0% +is either two nodes or three nodes that + + + align:start position:0% +is either two nodes or three nodes that +whose subtree has changed here uh it + + align:start position:0% +whose subtree has changed here uh it + + + align:start position:0% +whose subtree has changed here uh it +could have been the case that three + + align:start position:0% +could have been the case that three + + + align:start position:0% +could have been the case that three +sub trees have changed right but in the + + align:start position:0% +sub trees have changed right but in the + + + align:start position:0% +sub trees have changed right but in the +easy case + + align:start position:0% +easy case + + + align:start position:0% +easy case +only two nodes x and y i think in the + + align:start position:0% +only two nodes x and y i think in the + + + align:start position:0% +only two nodes x and y i think in the +notes + + align:start position:0% +notes + + + align:start position:0% +notes +could have changed and so when i do that + + align:start position:0% +could have changed and so when i do that + + + align:start position:0% +could have changed and so when i do that +i have to recompute + + align:start position:0% +i have to recompute + + + align:start position:0% +i have to recompute +their augmentations from their + + align:start position:0% +their augmentations from their + + + align:start position:0% +their augmentations from their +augmentations of their children + + align:start position:0% +augmentations of their children + + + align:start position:0% +augmentations of their children +but uh it's only a constant number of + + align:start position:0% +but uh it's only a constant number of + + + align:start position:0% +but uh it's only a constant number of +those so i just + + align:start position:0% +those so i just + + + align:start position:0% +those so i just +recompute them because i the sub trees + + align:start position:0% +recompute them because i the sub trees + + + align:start position:0% +recompute them because i the sub trees +below me haven't changed + + align:start position:0% +below me haven't changed + + + align:start position:0% +below me haven't changed +right okay so we have a height mismatch + + align:start position:0% +right okay so we have a height mismatch + + + align:start position:0% +right okay so we have a height mismatch +here + + align:start position:0% +here + + + align:start position:0% +here +yeah should be where + + align:start position:0% +yeah should be where + + + align:start position:0% +yeah should be where +eight is + + align:start position:0% + + + + align:start position:0% + +right so uh originally in the picture + + align:start position:0% +right so uh originally in the picture + + + align:start position:0% +right so uh originally in the picture +12 has a bunch of things in its subtree + + align:start position:0% +12 has a bunch of things in its subtree + + + align:start position:0% +12 has a bunch of things in its subtree +right + + align:start position:0% +right + + + align:start position:0% +right +10 and 8 and we just deleted seven right + + align:start position:0% +10 and 8 and we just deleted seven right + + + align:start position:0% +10 and 8 and we just deleted seven right +so its subtree definitely changed there + + align:start position:0% +so its subtree definitely changed there + + + align:start position:0% +so its subtree definitely changed there +used to be three + + align:start position:0% +used to be three + + + align:start position:0% +used to be three +oh no sorry it did right yeah so here + + align:start position:0% +oh no sorry it did right yeah so here + + + align:start position:0% +oh no sorry it did right yeah so here +three node sub trees have changed but + + align:start position:0% +three node sub trees have changed but + + + align:start position:0% +three node sub trees have changed but +uh that's the actually the most i'm + + align:start position:0% +uh that's the actually the most i'm + + + align:start position:0% +uh that's the actually the most i'm +showing you the worst + + align:start position:0% +showing you the worst + + + align:start position:0% +showing you the worst +case right only three nodes possible in + + align:start position:0% +case right only three nodes possible in + + + align:start position:0% +case right only three nodes possible in +doing one of these + + align:start position:0% +doing one of these + + + align:start position:0% +doing one of these +double rotation things could have + + align:start position:0% +double rotation things could have + + + align:start position:0% +double rotation things could have +changed their sub trees and so we just + + align:start position:0% +changed their sub trees and so we just + + + align:start position:0% +changed their sub trees and so we just +have to + + align:start position:0% +have to + + + align:start position:0% +have to +fix the augmentation of those three + + align:start position:0% +fix the augmentation of those three + + + align:start position:0% +fix the augmentation of those three +things in the easy case it's just two + + align:start position:0% +things in the easy case it's just two + + + align:start position:0% +things in the easy case it's just two +things + + align:start position:0% +things + + + align:start position:0% +things +okay all right we have a uh on balance + + align:start position:0% +okay all right we have a uh on balance + + + align:start position:0% +okay all right we have a uh on balance +how can we fix this + + align:start position:0% + + + + align:start position:0% + +i could have been mean right i wanna be + + align:start position:0% +i could have been mean right i wanna be + + + align:start position:0% +i could have been mean right i wanna be +able to + + align:start position:0% +able to + + + align:start position:0% +able to +right rotate here right to rebalance i + + align:start position:0% +right rotate here right to rebalance i + + + align:start position:0% +right rotate here right to rebalance i +could have been mean and switch these + + align:start position:0% +could have been mean and switch these + + + align:start position:0% +could have been mean and switch these +two + + align:start position:0% +two + + + align:start position:0% +two +right if i switch those two then i'd + + align:start position:0% +right if i switch those two then i'd + + + align:start position:0% +right if i switch those two then i'd +have to do two rotations to fix this + + align:start position:0% +have to do two rotations to fix this + + + align:start position:0% +have to do two rotations to fix this +thing because the middle one is heavier + + align:start position:0% +thing because the middle one is heavier + + + align:start position:0% +thing because the middle one is heavier +than the + + align:start position:0% +than the + + + align:start position:0% +than the +left one against what i'm doing right + + align:start position:0% +left one against what i'm doing right + + + align:start position:0% +left one against what i'm doing right +but i'm not that mean so i'm going to + + align:start position:0% +but i'm not that mean so i'm going to + + + align:start position:0% +but i'm not that mean so i'm going to +right rotate how do i do that well right + + align:start position:0% +right rotate how do i do that well right + + + align:start position:0% +right rotate how do i do that well right +rotate + + align:start position:0% +rotate + + + align:start position:0% +rotate +at 6 is going to bring all of this + + align:start position:0% +at 6 is going to bring all of this + + + align:start position:0% +at 6 is going to bring all of this +down below 4 right and stick this + + align:start position:0% +down below 4 right and stick this + + + align:start position:0% +down below 4 right and stick this +subtree + + align:start position:0% +subtree + + + align:start position:0% +subtree +as the left child of 6. does that make + + align:start position:0% +as the left child of 6. does that make + + + align:start position:0% +as the left child of 6. does that make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +yuck that's going to be fun to draw + + align:start position:0% + + + + align:start position:0% + +i'm just going to redraw it that makes + + align:start position:0% +i'm just going to redraw it that makes + + + align:start position:0% +i'm just going to redraw it that makes +more sense right + + align:start position:0% + + + + align:start position:0% + +uh eleven three two + + align:start position:0% +uh eleven three two + + + align:start position:0% +uh eleven three two +one and then six + + align:start position:0% + + + + align:start position:0% + +five nine + + align:start position:0% +five nine + + + align:start position:0% +five nine +eight twelve + + align:start position:0% + + + + align:start position:0% + +ten that's the right rotation + + align:start position:0% +ten that's the right rotation + + + align:start position:0% +ten that's the right rotation +at six is everyone cool with this + + align:start position:0% +at six is everyone cool with this + + + align:start position:0% +at six is everyone cool with this +the rotation my x is 6 my y is 4 + + align:start position:0% +the rotation my x is 6 my y is 4 + + + align:start position:0% +the rotation my x is 6 my y is 4 +right i have a b c sub trees + + align:start position:0% +right i have a b c sub trees + + + align:start position:0% +right i have a b c sub trees +right what i'm doing is kind of + + align:start position:0% +right what i'm doing is kind of + + + align:start position:0% +right what i'm doing is kind of +switching + + align:start position:0% +switching + + + align:start position:0% +switching +which of x and y is the root here right + + align:start position:0% +which of x and y is the root here right + + + align:start position:0% +which of x and y is the root here right +so now y is the root + + align:start position:0% +so now y is the root + + + align:start position:0% +so now y is the root +and b and c sub trees here now become + + align:start position:0% +and b and c sub trees here now become + + + align:start position:0% +and b and c sub trees here now become +the children of x + + align:start position:0% +the children of x + + + align:start position:0% +the children of x +underneath y and notice that hopefully + + align:start position:0% +underneath y and notice that hopefully + + + align:start position:0% +underneath y and notice that hopefully +through all that process + + align:start position:0% +through all that process + + + align:start position:0% +through all that process +my inorder traversal has not changed + + align:start position:0% +my inorder traversal has not changed + + + align:start position:0% +my inorder traversal has not changed +we had to update our augmentations along + + align:start position:0% +we had to update our augmentations along + + + align:start position:0% +we had to update our augmentations along +the way but you know it's a constant + + align:start position:0% +the way but you know it's a constant + + + align:start position:0% +the way but you know it's a constant +every time we walk up the tree + + align:start position:0% +every time we walk up the tree + + + align:start position:0% +every time we walk up the tree +and we walk up the tree only a + + align:start position:0% +and we walk up the tree only a + + + align:start position:0% +and we walk up the tree only a +logarithmic number of times yeah + + align:start position:0% +logarithmic number of times yeah + + + align:start position:0% +logarithmic number of times yeah +yes so every time we do a rotation we + + align:start position:0% +yes so every time we do a rotation we + + + align:start position:0% +yes so every time we do a rotation we +just like + + align:start position:0% +just like + + + align:start position:0% +just like +update the augmentation immediately + + align:start position:0% +update the augmentation immediately + + + align:start position:0% +update the augmentation immediately +afterwards before we do any other + + align:start position:0% +afterwards before we do any other + + + align:start position:0% +afterwards before we do any other +routine exactly + + align:start position:0% +routine exactly + + + align:start position:0% +routine exactly +second part updating documentation just + + align:start position:0% +second part updating documentation just + + + align:start position:0% +second part updating documentation just +means like + + align:start position:0% +means like + + + align:start position:0% +means like +updating like the count and the height + + align:start position:0% +updating like the count and the height + + + align:start position:0% +updating like the count and the height +just the properties and stuff yeah + + align:start position:0% +just the properties and stuff yeah + + + align:start position:0% +just the properties and stuff yeah +basically what we did we + + align:start position:0% +basically what we did we + + + align:start position:0% +basically what we did we +define when we augmented uh professor + + align:start position:0% +define when we augmented uh professor + + + align:start position:0% +define when we augmented uh professor +domain yesterday + + align:start position:0% +domain yesterday + + + align:start position:0% +domain yesterday +defined for you what a subtree property + + align:start position:0% +defined for you what a subtree property + + + align:start position:0% +defined for you what a subtree property +is right + + align:start position:0% +is right + + + align:start position:0% +is right +it meant a property that i can compute + + align:start position:0% +it meant a property that i can compute + + + align:start position:0% +it meant a property that i can compute +only by looking at my children + + align:start position:0% +only by looking at my children + + + align:start position:0% +only by looking at my children +the augmentations of my children + + align:start position:0% +the augmentations of my children + + + align:start position:0% +the augmentations of my children +recursively right + + align:start position:0% +recursively right + + + align:start position:0% +recursively right +so here uh instead of trying to + + align:start position:0% +so here uh instead of trying to + + + align:start position:0% +so here uh instead of trying to +increment or try to think about locally + + align:start position:0% +increment or try to think about locally + + + align:start position:0% +increment or try to think about locally +what this augmentation should be + + align:start position:0% +what this augmentation should be + + + align:start position:0% +what this augmentation should be +i'm going to throw away my old + + align:start position:0% +i'm going to throw away my old + + + align:start position:0% +i'm going to throw away my old +augmentation and just recompute it from + + align:start position:0% +augmentation and just recompute it from + + + align:start position:0% +augmentation and just recompute it from +my children because + + align:start position:0% +my children because + + + align:start position:0% +my children because +those recursively better be correct does + + align:start position:0% +those recursively better be correct does + + + align:start position:0% +those recursively better be correct does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +yeah so just looking at how the rotation + + align:start position:0% +yeah so just looking at how the rotation + + + align:start position:0% +yeah so just looking at how the rotation +works + + align:start position:0% + + + + align:start position:0% + +so basically you're swapping four and + + align:start position:0% +so basically you're swapping four and + + + align:start position:0% +so basically you're swapping four and +six so that way four becomes the parent + + align:start position:0% +six so that way four becomes the parent + + + align:start position:0% +six so that way four becomes the parent +node + + align:start position:0% +node + + + align:start position:0% +node +and six becomes the right note + + align:start position:0% +and six becomes the right note + + + align:start position:0% +and six becomes the right note +i'm gonna draw this picture just + + align:start position:0% +i'm gonna draw this picture just + + + align:start position:0% +i'm gonna draw this picture just +it's just something you gotta memorize + + align:start position:0% +it's just something you gotta memorize + + + align:start position:0% +it's just something you gotta memorize +it's + + align:start position:0% +it's + + + align:start position:0% +it's +this is x b + + align:start position:0% +this is x b + + + align:start position:0% +this is x b +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +c and a + + align:start position:0% +c and a + + + align:start position:0% +c and a +can you see that picture okay + + align:start position:0% + + + + align:start position:0% + +yeah it's in your notes it's not a big + + align:start position:0% +yeah it's in your notes it's not a big + + + align:start position:0% +yeah it's in your notes it's not a big +deal right + + align:start position:0% +deal right + + + align:start position:0% +deal right +but if you've got this structure where + + align:start position:0% +but if you've got this structure where + + + align:start position:0% +but if you've got this structure where +x has a left child right + + align:start position:0% +x has a left child right + + + align:start position:0% +x has a left child right +and these sub trees may be empty or not + + align:start position:0% +and these sub trees may be empty or not + + + align:start position:0% +and these sub trees may be empty or not +doesn't really matter what i can do is i + + align:start position:0% +doesn't really matter what i can do is i + + + align:start position:0% +doesn't really matter what i can do is i +can + + align:start position:0% +can + + + align:start position:0% +can +move from here to there has the same + + align:start position:0% +move from here to there has the same + + + align:start position:0% +move from here to there has the same +in-order traversal order + + align:start position:0% +in-order traversal order + + + align:start position:0% +in-order traversal order +right but it's got a different shape and + + align:start position:0% +right but it's got a different shape and + + + align:start position:0% +right but it's got a different shape and +in particular subtree + + align:start position:0% +in particular subtree + + + align:start position:0% +in particular subtree +heights have changed which means it can + + align:start position:0% +heights have changed which means it can + + + align:start position:0% +heights have changed which means it can +help us rebalance the tree + + align:start position:0% +help us rebalance the tree + + + align:start position:0% +help us rebalance the tree +and that's that's the whole point of avl + + align:start position:0% +and that's that's the whole point of avl + + + align:start position:0% +and that's that's the whole point of avl +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +and that's the right rotation this one + + align:start position:0% +and that's the right rotation this one + + + align:start position:0% +and that's the right rotation this one +is this is a right rotation this is a + + align:start position:0% +is this is a right rotation this is a + + + align:start position:0% +is this is a right rotation this is a +left rotation + + align:start position:0% +left rotation + + + align:start position:0% +left rotation +any other questions + + align:start position:0% + + + + align:start position:0% + +so as i'm walking up the tree every node + + align:start position:0% +so as i'm walking up the tree every node + + + align:start position:0% +so as i'm walking up the tree every node +i might have to fix with the rebalance + + align:start position:0% +i might have to fix with the rebalance + + + align:start position:0% +i might have to fix with the rebalance +but that rebalance does at most two + + align:start position:0% +but that rebalance does at most two + + + align:start position:0% +but that rebalance does at most two +rotations + + align:start position:0% +rotations + + + align:start position:0% +rotations +and there's at most log n ancestors that + + align:start position:0% +and there's at most log n ancestors that + + + align:start position:0% +and there's at most log n ancestors that +i have + + align:start position:0% +i have + + + align:start position:0% +i have +because my tree is height balance right + + align:start position:0% +because my tree is height balance right + + + align:start position:0% +because my tree is height balance right +at 2 2 log n or something like that + + align:start position:0% +at 2 2 log n or something like that + + + align:start position:0% +at 2 2 log n or something like that +right + + align:start position:0% +right + + + align:start position:0% +right +which means that at max i might have to + + align:start position:0% +which means that at max i might have to + + + align:start position:0% +which means that at max i might have to +do + + align:start position:0% +do + + + align:start position:0% +do +four log n rotations right because each + + align:start position:0% +four log n rotations right because each + + + align:start position:0% +four log n rotations right because each +one could + + align:start position:0% +one could + + + align:start position:0% +one could +do two rotations so that makes sense now + + align:start position:0% +do two rotations so that makes sense now + + + align:start position:0% +do two rotations so that makes sense now +in actuality you can prove that in a + + align:start position:0% +in actuality you can prove that in a + + + align:start position:0% +in actuality you can prove that in a +delete operation + + align:start position:0% +delete operation + + + align:start position:0% +delete operation +it's possible that you have to do a + + align:start position:0% +it's possible that you have to do a + + + align:start position:0% +it's possible that you have to do a +logarithmic number of these rotations up + + align:start position:0% +logarithmic number of these rotations up + + + align:start position:0% +logarithmic number of these rotations up +the tree + + align:start position:0% +the tree + + + align:start position:0% +the tree +this was a that bad case this is called + + align:start position:0% +this was a that bad case this is called + + + align:start position:0% +this was a that bad case this is called +the original tree i gave you is called a + + align:start position:0% +the original tree i gave you is called a + + + align:start position:0% +the original tree i gave you is called a +fibonacci tree + + align:start position:0% +fibonacci tree + + + align:start position:0% +fibonacci tree +it's the fewest it's the highest uh + + align:start position:0% +it's the fewest it's the highest uh + + + align:start position:0% +it's the fewest it's the highest uh +height balanced tree you can have on a + + align:start position:0% +height balanced tree you can have on a + + + align:start position:0% +height balanced tree you can have on a +on a given number of nodes + + align:start position:0% +on a given number of nodes + + + align:start position:0% +on a given number of nodes +um uh that's it's + + align:start position:0% +um uh that's it's + + + align:start position:0% +um uh that's it's +yeah the fewest nodes for a certain + + align:start position:0% +yeah the fewest nodes for a certain + + + align:start position:0% +yeah the fewest nodes for a certain +height i i you can think of it either + + align:start position:0% +height i i you can think of it either + + + align:start position:0% +height i i you can think of it either +way + + align:start position:0% +way + + + align:start position:0% +way +and if you generalize that to a large + + align:start position:0% +and if you generalize that to a large + + + align:start position:0% +and if you generalize that to a large +enough thing then that thing will take a + + align:start position:0% +enough thing then that thing will take a + + + align:start position:0% +enough thing then that thing will take a +logarithmic number of rotations going up + + align:start position:0% +logarithmic number of rotations going up + + + align:start position:0% +logarithmic number of rotations going up +now actually with an insertion you can + + align:start position:0% +now actually with an insertion you can + + + align:start position:0% +now actually with an insertion you can +actually prove you can go through the + + align:start position:0% +actually prove you can go through the + + + align:start position:0% +actually prove you can go through the +case analysis + + align:start position:0% +case analysis + + + align:start position:0% +case analysis +uh an insertion operation will always + + align:start position:0% +uh an insertion operation will always + + + align:start position:0% +uh an insertion operation will always +rebalance the tree after one + + align:start position:0% +rebalance the tree after one + + + align:start position:0% +rebalance the tree after one +after one rebalance operation which + + align:start position:0% +after one rebalance operation which + + + align:start position:0% +after one rebalance operation which +could include two rotations does that + + align:start position:0% +could include two rotations does that + + + align:start position:0% +could include two rotations does that +make sense + + align:start position:0% + + + + align:start position:0% + +yeah so in right rotation this guy + + align:start position:0% +yeah so in right rotation this guy + + + align:start position:0% +yeah so in right rotation this guy +becomes a right child + + align:start position:0% +becomes a right child + + + align:start position:0% +becomes a right child +yes + + align:start position:0% + + + + align:start position:0% + +depending on whether you have a child + + align:start position:0% +depending on whether you have a child + + + align:start position:0% +depending on whether you have a child +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +if i didn't have a left subtree + + align:start position:0% +if i didn't have a left subtree + + + align:start position:0% +if i didn't have a left subtree +can't perform rotation a right rotation + + align:start position:0% +can't perform rotation a right rotation + + + align:start position:0% +can't perform rotation a right rotation +there + + align:start position:0% +there + + + align:start position:0% +there +yeah so a right rotation necessitates + + align:start position:0% +yeah so a right rotation necessitates + + + align:start position:0% +yeah so a right rotation necessitates +that i have a left child so if you're + + align:start position:0% +that i have a left child so if you're + + + align:start position:0% +that i have a left child so if you're +doing it + + align:start position:0% +doing it + + + align:start position:0% +doing it +and you'll see our code actually checks + + align:start position:0% +and you'll see our code actually checks + + + align:start position:0% +and you'll see our code actually checks +to make sure you have a left child + + align:start position:0% +to make sure you have a left child + + + align:start position:0% +to make sure you have a left child +right uh + + align:start position:0% +right uh + + + align:start position:0% +right uh +that's that's a an assertion that you + + align:start position:0% +that's that's a an assertion that you + + + align:start position:0% +that's that's a an assertion that you +might want to fire before you ever do + + align:start position:0% +might want to fire before you ever do + + + align:start position:0% +might want to fire before you ever do +one of these rotations + + align:start position:0% +one of these rotations + + + align:start position:0% +one of these rotations +anything else yeah so an insertion may + + align:start position:0% +anything else yeah so an insertion may + + + align:start position:0% +anything else yeah so an insertion may +take + + align:start position:0% +take + + + align:start position:0% +take +two rotations at most to fix a constant + + align:start position:0% +two rotations at most to fix a constant + + + align:start position:0% +two rotations at most to fix a constant +number of rotations and the deletion + + align:start position:0% +number of rotations and the deletion + + + align:start position:0% +number of rotations and the deletion +could take a logarithmic number of + + align:start position:0% +could take a logarithmic number of + + + align:start position:0% +could take a logarithmic number of +partitions + + align:start position:0% +partitions + + + align:start position:0% +partitions +now that's not something you need to + + align:start position:0% +now that's not something you need to + + + align:start position:0% +now that's not something you need to +know it's not something i'm proving here + + align:start position:0% +know it's not something i'm proving here + + + align:start position:0% +know it's not something i'm proving here +to you + + align:start position:0% +to you + + + align:start position:0% +to you +uh just just something that's + + align:start position:0% +uh just just something that's + + + align:start position:0% +uh just just something that's +interesting there are rebalancing + + align:start position:0% +interesting there are rebalancing + + + align:start position:0% +interesting there are rebalancing +schemes like + + align:start position:0% +schemes like + + + align:start position:0% +schemes like +in in clrs right they they introduce + + align:start position:0% +in in clrs right they they introduce + + + align:start position:0% +in in clrs right they they introduce +a a red black tree to to introduce + + align:start position:0% +a a red black tree to to introduce + + + align:start position:0% +a a red black tree to to introduce +balance + + align:start position:0% +balance + + + align:start position:0% +balance +and that those trees actually have a + + align:start position:0% +and that those trees actually have a + + + align:start position:0% +and that those trees actually have a +weaker bound on + + align:start position:0% +weaker bound on + + + align:start position:0% +weaker bound on +it's not as is tightly height balanced + + align:start position:0% +it's not as is tightly height balanced + + + align:start position:0% +it's not as is tightly height balanced +as as an + + align:start position:0% +as as an + + + align:start position:0% +as as an +avl tree is it allows higher than skew + + align:start position:0% +avl tree is it allows higher than skew + + + align:start position:0% +avl tree is it allows higher than skew +to right uh and because it's + + align:start position:0% +to right uh and because it's + + + align:start position:0% +to right uh and because it's +kind of a weaker restriction they get + + align:start position:0% +kind of a weaker restriction they get + + + align:start position:0% +kind of a weaker restriction they get +away with only doing a constant number + + align:start position:0% +away with only doing a constant number + + + align:start position:0% +away with only doing a constant number +of rotations that + + align:start position:0% +of rotations that + + + align:start position:0% +of rotations that +they can afford that before they fix the + + align:start position:0% +they can afford that before they fix the + + + align:start position:0% +they can afford that before they fix the +tree + + align:start position:0% +tree + + + align:start position:0% +tree +uh but you know a little more + + align:start position:0% +uh but you know a little more + + + align:start position:0% +uh but you know a little more +complicated + + align:start position:0% + + + + align:start position:0% + +very nice okay any questions on this + + align:start position:0% +very nice okay any questions on this + + + align:start position:0% +very nice okay any questions on this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh now so this is more of a + + align:start position:0% +so uh now so this is more of a + + + align:start position:0% +so uh now so this is more of a +mechanical question + + align:start position:0% +mechanical question + + + align:start position:0% +mechanical question +you'll get on your problem sets and now + + align:start position:0% +you'll get on your problem sets and now + + + align:start position:0% +you'll get on your problem sets and now +we get more onto the uh + + align:start position:0% +we get more onto the uh + + + align:start position:0% +we get more onto the uh +the theory type questions these are + + align:start position:0% +the theory type questions these are + + + align:start position:0% +the theory type questions these are +going to be reduction type questions + + align:start position:0% +going to be reduction type questions + + + align:start position:0% +going to be reduction type questions +uh okay so this first problem uh + + align:start position:0% +uh okay so this first problem uh + + + align:start position:0% +uh okay so this first problem uh +thick nuri uh this is + + align:start position:0% +thick nuri uh this is + + + align:start position:0% +thick nuri uh this is +anyone nick fury right so it's a + + align:start position:0% +anyone nick fury right so it's a + + + align:start position:0% +anyone nick fury right so it's a +an avengers reference uh so basically + + align:start position:0% +an avengers reference uh so basically + + + align:start position:0% +an avengers reference uh so basically +what happens in this thing he's got a + + align:start position:0% +what happens in this thing he's got a + + + align:start position:0% +what happens in this thing he's got a +list of + + align:start position:0% +list of + + + align:start position:0% +list of +superheroes uh that each have an opinion + + align:start position:0% +superheroes uh that each have an opinion + + + align:start position:0% +superheroes uh that each have an opinion +on whether they should go fight santa's + + align:start position:0% +on whether they should go fight santa's + + + align:start position:0% +on whether they should go fight santa's +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and uh their opinion + + align:start position:0% +and uh their opinion + + + align:start position:0% +and uh their opinion +can be strongly positive or strongly + + align:start position:0% +can be strongly positive or strongly + + + align:start position:0% +can be strongly positive or strongly +negative + + align:start position:0% +negative + + + align:start position:0% +negative +and so what uh fick is trying to do is + + align:start position:0% +and so what uh fick is trying to do is + + + align:start position:0% +and so what uh fick is trying to do is +find from among his + + align:start position:0% +find from among his + + + align:start position:0% +find from among his +revengers uh what their + + align:start position:0% +revengers uh what their + + + align:start position:0% +revengers uh what their +what the log n most extreme + + align:start position:0% +what the log n most extreme + + + align:start position:0% +what the log n most extreme +opinion revengers are so that you can + + align:start position:0% +opinion revengers are so that you can + + + align:start position:0% +opinion revengers are so that you can +talk to them right he doesn't want to + + align:start position:0% +talk to them right he doesn't want to + + + align:start position:0% +talk to them right he doesn't want to +talk to everybody he wants to talk to a + + align:start position:0% +talk to everybody he wants to talk to a + + + align:start position:0% +talk to everybody he wants to talk to a +you know logarithmic number of them okay + + align:start position:0% +you know logarithmic number of them okay + + + align:start position:0% +you know logarithmic number of them okay +it's kind of + + align:start position:0% +it's kind of + + + align:start position:0% +it's kind of +whatever all right so uh basically + + align:start position:0% +whatever all right so uh basically + + + align:start position:0% +whatever all right so uh basically +we have a uh a classified situation + + align:start position:0% +we have a uh a classified situation + + + align:start position:0% +we have a uh a classified situation +where you're given as a read-only input + + align:start position:0% +where you're given as a read-only input + + + align:start position:0% +where you're given as a read-only input +data store + + align:start position:0% +data store + + + align:start position:0% +data store +of these things in an array okay + + align:start position:0% +of these things in an array okay + + + align:start position:0% +of these things in an array okay +and i want to find the log n + + align:start position:0% +and i want to find the log n + + + align:start position:0% +and i want to find the log n +ones with the strongest opinions does + + align:start position:0% +ones with the strongest opinions does + + + align:start position:0% +ones with the strongest opinions does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +and i want to do it and the first + + align:start position:0% +and i want to do it and the first + + + align:start position:0% +and i want to do it and the first +problem is in linear time + + align:start position:0% +problem is in linear time + + + align:start position:0% +problem is in linear time +okay so you actually don't know how to + + align:start position:0% +okay so you actually don't know how to + + + align:start position:0% +okay so you actually don't know how to +do this yet + + align:start position:0% + + + + align:start position:0% + +you'll know how to do it with material + + align:start position:0% +you'll know how to do it with material + + + align:start position:0% +you'll know how to do it with material +that you cover + + align:start position:0% +that you cover + + + align:start position:0% +that you cover +in uh well they teach you one way to do + + align:start position:0% +in uh well they teach you one way to do + + + align:start position:0% +in uh well they teach you one way to do +it in o46 but we're not going to get you + + align:start position:0% +it in o46 but we're not going to get you + + + align:start position:0% +it in o46 but we're not going to get you +there right now uh we'll teach you + + align:start position:0% +there right now uh we'll teach you + + + align:start position:0% +there right now uh we'll teach you +another way to do it + + align:start position:0% +another way to do it + + + align:start position:0% +another way to do it +uh in uh on tuesday + + align:start position:0% +uh in uh on tuesday + + + align:start position:0% +uh in uh on tuesday +right which is via binary heaps okay + + align:start position:0% +right which is via binary heaps okay + + + align:start position:0% +right which is via binary heaps okay +binary heaps are an interesting thing + + align:start position:0% +binary heaps are an interesting thing + + + align:start position:0% +binary heaps are an interesting thing +that implements a subset + + align:start position:0% + + + + align:start position:0% + +of the set interface okay + + align:start position:0% +of the set interface okay + + + align:start position:0% +of the set interface okay +really it just you can build + + align:start position:0% + + + + align:start position:0% + +on some iterable x okay i + + align:start position:0% +on some iterable x okay i + + + align:start position:0% +on some iterable x okay i +collect a bunch of things these items + + align:start position:0% +collect a bunch of things these items + + + align:start position:0% +collect a bunch of things these items +have keys right it's a key + + align:start position:0% +have keys right it's a key + + + align:start position:0% +have keys right it's a key +data structure in the same way it's + + align:start position:0% +data structure in the same way it's + + + align:start position:0% +data structure in the same way it's +implementing what we call a priority + + align:start position:0% +implementing what we call a priority + + + align:start position:0% +implementing what we call a priority +queue interface i can build these things + + align:start position:0% +queue interface i can build these things + + + align:start position:0% +queue interface i can build these things +i can insert things + + align:start position:0% +i can insert things + + + align:start position:0% +i can insert things +but i'm not going to do that here all i + + align:start position:0% +but i'm not going to do that here all i + + + align:start position:0% +but i'm not going to do that here all i +really need here for this + + align:start position:0% +really need here for this + + + align:start position:0% +really need here for this +situation is a delete superlative kind + + align:start position:0% +situation is a delete superlative kind + + + align:start position:0% +situation is a delete superlative kind +of operation in this case + + align:start position:0% +of operation in this case + + + align:start position:0% +of operation in this case +probably max delete + + align:start position:0% +probably max delete + + + align:start position:0% +probably max delete +max + + align:start position:0% + + + + align:start position:0% + +okay so this is like a i got a data + + align:start position:0% +okay so this is like a i got a data + + + align:start position:0% +okay so this is like a i got a data +structure + + align:start position:0% +structure + + + align:start position:0% +structure +right i'm calling these things does that + + align:start position:0% +right i'm calling these things does that + + + align:start position:0% +right i'm calling these things does that +make sense yeah that's a priority + + align:start position:0% +make sense yeah that's a priority + + + align:start position:0% +make sense yeah that's a priority +yes a priority queue is essentially + + align:start position:0% +yes a priority queue is essentially + + + align:start position:0% +yes a priority queue is essentially +something that implements these two + + align:start position:0% +something that implements these two + + + align:start position:0% +something that implements these two +things + + align:start position:0% +things + + + align:start position:0% +things +actually there's a third one where i can + + align:start position:0% +actually there's a third one where i can + + + align:start position:0% +actually there's a third one where i can +insert a new thing right but i'm not + + align:start position:0% +insert a new thing right but i'm not + + + align:start position:0% +insert a new thing right but i'm not +going to need that right now + + align:start position:0% +going to need that right now + + + align:start position:0% +going to need that right now +so that's what a priority queue is and + + align:start position:0% +so that's what a priority queue is and + + + align:start position:0% +so that's what a priority queue is and +actually a set this is a subset of the + + align:start position:0% +actually a set this is a subset of the + + + align:start position:0% +actually a set this is a subset of the +set + + align:start position:0% +set + + + align:start position:0% +set +interface right right the nice thing + + align:start position:0% +interface right right the nice thing + + + align:start position:0% +interface right right the nice thing +about + + align:start position:0% +about + + + align:start position:0% +about +a heap which i won't show you how it's + + align:start position:0% +a heap which i won't show you how it's + + + align:start position:0% +a heap which i won't show you how it's +done + + align:start position:0% +done + + + align:start position:0% +done +right but what a heap can do so + + align:start position:0% +right but what a heap can do so + + + align:start position:0% +right but what a heap can do so +if i had both of these operations + + align:start position:0% +if i had both of these operations + + + align:start position:0% +if i had both of these operations +implemented using a + + align:start position:0% +implemented using a + + + align:start position:0% +implemented using a +set avl tree how long would these things + + align:start position:0% +set avl tree how long would these things + + + align:start position:0% +set avl tree how long would these things +take me + + align:start position:0% + + + + align:start position:0% + +how long does it take to build a set avl + + align:start position:0% +how long does it take to build a set avl + + + align:start position:0% +how long does it take to build a set avl +tree + + align:start position:0% + + + + align:start position:0% + +and log in right because essentially i'm + + align:start position:0% +and log in right because essentially i'm + + + align:start position:0% +and log in right because essentially i'm +getting a sorted order out of this thing + + align:start position:0% +getting a sorted order out of this thing + + + align:start position:0% +getting a sorted order out of this thing +right if i'm inserting these things one + + align:start position:0% +right if i'm inserting these things one + + + align:start position:0% +right if i'm inserting these things one +at a time right + + align:start position:0% +at a time right + + + align:start position:0% +at a time right +or i could sort them and then put them + + align:start position:0% +or i could sort them and then put them + + + align:start position:0% +or i could sort them and then put them +in a tree in linear time like you saw + + align:start position:0% +in a tree in linear time like you saw + + + align:start position:0% +in a tree in linear time like you saw +a couple days ago right in recitation + + align:start position:0% +a couple days ago right in recitation + + + align:start position:0% +a couple days ago right in recitation +but i have to sort them at some point + + align:start position:0% +but i have to sort them at some point + + + align:start position:0% +but i have to sort them at some point +right i'm kind of + + align:start position:0% +right i'm kind of + + + align:start position:0% +right i'm kind of +i need to take at least n log n time + + align:start position:0% +i need to take at least n log n time + + + align:start position:0% +i need to take at least n log n time +because + + align:start position:0% +because + + + align:start position:0% +because +if i'm going to be able to return their + + align:start position:0% +if i'm going to be able to return their + + + align:start position:0% +if i'm going to be able to return their +order their traversal order in linear + + align:start position:0% +order their traversal order in linear + + + align:start position:0% +order their traversal order in linear +time + + align:start position:0% +time + + + align:start position:0% +time +and i have this lower bound of m log n + + align:start position:0% +and i have this lower bound of m log n + + + align:start position:0% +and i have this lower bound of m log n +on sorting i kind of needed to spend and + + align:start position:0% +on sorting i kind of needed to spend and + + + align:start position:0% +on sorting i kind of needed to spend and +log in + + align:start position:0% +log in + + + align:start position:0% +log in +time here right and how long would this + + align:start position:0% +time here right and how long would this + + + align:start position:0% +time here right and how long would this +delete max take + + align:start position:0% + + + + align:start position:0% + +i started so long log in right so it's a + + align:start position:0% +i started so long log in right so it's a + + + align:start position:0% +i started so long log in right so it's a +set avl tree + + align:start position:0% +set avl tree + + + align:start position:0% +set avl tree +where is my max it's the rightmost thing + + align:start position:0% +where is my max it's the rightmost thing + + + align:start position:0% +where is my max it's the rightmost thing +i can just walk down the thing + + align:start position:0% +i can just walk down the thing + + + align:start position:0% +i can just walk down the thing +take it off maybe i have to rebalance + + align:start position:0% +take it off maybe i have to rebalance + + + align:start position:0% +take it off maybe i have to rebalance +but you know that's a login + + align:start position:0% +but you know that's a login + + + align:start position:0% +but you know that's a login +operation right it's the same as like + + align:start position:0% +operation right it's the same as like + + + align:start position:0% +operation right it's the same as like +insert last in my substrate + + align:start position:0% +insert last in my substrate + + + align:start position:0% +insert last in my substrate +right so for a set avl tree + + align:start position:0% +right so for a set avl tree + + + align:start position:0% +right so for a set avl tree +this is n log n this is uh log n + + align:start position:0% +this is n log n this is uh log n + + + align:start position:0% +this is n log n this is uh log n +right now + + align:start position:0% +right now + + + align:start position:0% +right now +there's another data structure that does + + align:start position:0% +there's another data structure that does + + + align:start position:0% +there's another data structure that does +better for one of these operations and + + align:start position:0% +better for one of these operations and + + + align:start position:0% +better for one of these operations and +the same for the other one + + align:start position:0% +the same for the other one + + + align:start position:0% +the same for the other one +that we've learned earlier + + align:start position:0% +that we've learned earlier + + + align:start position:0% +that we've learned earlier +anyone remember said avl tree didn't + + align:start position:0% +anyone remember said avl tree didn't + + + align:start position:0% +anyone remember said avl tree didn't +actually give us anything over + + align:start position:0% +actually give us anything over + + + align:start position:0% +actually give us anything over +a sorted array in a dynamic + + align:start position:0% +a sorted array in a dynamic + + + align:start position:0% +a sorted array in a dynamic +array okay so what that did right + + align:start position:0% +array okay so what that did right + + + align:start position:0% +array okay so what that did right +was we have a we could sort it in n log + + align:start position:0% +was we have a we could sort it in n log + + + align:start position:0% +was we have a we could sort it in n log +n time using merge sort or something + + align:start position:0% +n time using merge sort or something + + + align:start position:0% +n time using merge sort or something +like that + + align:start position:0% +like that + + + align:start position:0% +like that +and then we could just pop off the last + + align:start position:0% +and then we could just pop off the last + + + align:start position:0% +and then we could just pop off the last +one end times right + + align:start position:0% +one end times right + + + align:start position:0% +one end times right +that would be an amortize i mean if i + + align:start position:0% +that would be an amortize i mean if i + + + align:start position:0% +that would be an amortize i mean if i +didn't care about + + align:start position:0% +didn't care about + + + align:start position:0% +didn't care about +taking up that size i could do it in + + align:start position:0% +taking up that size i could do it in + + + align:start position:0% +taking up that size i could do it in +worse case constant time i just read off + + align:start position:0% +worse case constant time i just read off + + + align:start position:0% +worse case constant time i just read off +the first + + align:start position:0% +the first + + + align:start position:0% +the first +the last one i don't need to resize the + + align:start position:0% +the last one i don't need to resize the + + + align:start position:0% +the last one i don't need to resize the +array ever right i can just + + align:start position:0% +array ever right i can just + + + align:start position:0% +array ever right i can just +ignore that does that make sense okay + + align:start position:0% +ignore that does that make sense okay + + + align:start position:0% +ignore that does that make sense okay +but that's okay if i had a data + + align:start position:0% +but that's okay if i had a data + + + align:start position:0% +but that's okay if i had a data +structure + + align:start position:0% +structure + + + align:start position:0% +structure +that implemented these two operations + + align:start position:0% +that implemented these two operations + + + align:start position:0% +that implemented these two operations +can someone tell me a + + align:start position:0% + + + + align:start position:0% + +uh an algorithm to generate + + align:start position:0% +uh an algorithm to generate + + + align:start position:0% +uh an algorithm to generate +fixed list don't worry about running + + align:start position:0% +fixed list don't worry about running + + + align:start position:0% +fixed list don't worry about running +time right now but that just uses these + + align:start position:0% +time right now but that just uses these + + + align:start position:0% +time right now but that just uses these +two operations + + align:start position:0% + + + + align:start position:0% + +yeah um so we built the data structure + + align:start position:0% +yeah um so we built the data structure + + + align:start position:0% +yeah um so we built the data structure +it's ordered from least to greatest for + + align:start position:0% +it's ordered from least to greatest for + + + align:start position:0% +it's ordered from least to greatest for +absolute value + + align:start position:0% +absolute value + + + align:start position:0% +absolute value +so don't don't don't worry about uh + + align:start position:0% +so don't don't don't worry about uh + + + align:start position:0% +so don't don't don't worry about uh +where things are ordered or anything + + align:start position:0% +where things are ordered or anything + + + align:start position:0% +where things are ordered or anything +like that i don't tell you how these + + align:start position:0% +like that i don't tell you how these + + + align:start position:0% +like that i don't tell you how these +things + + align:start position:0% +things + + + align:start position:0% +things +are implemented right all i'm saying is + + align:start position:0% +are implemented right all i'm saying is + + + align:start position:0% +are implemented right all i'm saying is +i can + + align:start position:0% +i can + + + align:start position:0% +i can +i can accept a bunch of these things and + + align:start position:0% +i can accept a bunch of these things and + + + align:start position:0% +i can accept a bunch of these things and +i can + + align:start position:0% +i can + + + align:start position:0% +i can +remove the maximum and return it + + align:start position:0% +remove the maximum and return it + + + align:start position:0% +remove the maximum and return it +okay yeah anyways just build it but make + + align:start position:0% +okay yeah anyways just build it but make + + + align:start position:0% +okay yeah anyways just build it but make +sure that you build it such that the + + align:start position:0% +sure that you build it such that the + + + align:start position:0% +sure that you build it such that the +opinion levels are the absolute value of + + align:start position:0% +opinion levels are the absolute value of + + + align:start position:0% +opinion levels are the absolute value of +the opinion levels sure okay + + align:start position:0% +the opinion levels sure okay + + + align:start position:0% +the opinion levels sure okay +so that's that's a nice thing what i'm + + align:start position:0% +so that's that's a nice thing what i'm + + + align:start position:0% +so that's that's a nice thing what i'm +going to do as your colleague is saying + + align:start position:0% +going to do as your colleague is saying + + + align:start position:0% +going to do as your colleague is saying +is i'm going to look through all of the + + align:start position:0% +is i'm going to look through all of the + + + align:start position:0% +is i'm going to look through all of the +things in my input i'm going to + + align:start position:0% +things in my input i'm going to + + + align:start position:0% +things in my input i'm going to +copy it over to some writable memory + + align:start position:0% +copy it over to some writable memory + + + align:start position:0% +copy it over to some writable memory +store + + align:start position:0% +store + + + align:start position:0% +store +okay right that read-only thing is not + + align:start position:0% +okay right that read-only thing is not + + + align:start position:0% +okay right that read-only thing is not +relevant to this part of the problem + + align:start position:0% +relevant to this part of the problem + + + align:start position:0% +relevant to this part of the problem +right what i'm going to do is uh + + align:start position:0% + + + + align:start position:0% + +right sorry i'm thinking about your + + align:start position:0% +right sorry i'm thinking about your + + + align:start position:0% +right sorry i'm thinking about your +problem set that we're writing + + align:start position:0% +problem set that we're writing + + + align:start position:0% +problem set that we're writing +and mixing it up okay so uh we copy it + + align:start position:0% +and mixing it up okay so uh we copy it + + + align:start position:0% +and mixing it up okay so uh we copy it +over + + align:start position:0% +over + + + align:start position:0% +over +to uh our new uh like linear size + + align:start position:0% +to uh our new uh like linear size + + + align:start position:0% +to uh our new uh like linear size +array right and but instead of putting + + align:start position:0% +array right and but instead of putting + + + align:start position:0% +array right and but instead of putting +their values there i'm going to put the + + align:start position:0% +their values there i'm going to put the + + + align:start position:0% +their values there i'm going to put the +absolute values of their values that + + align:start position:0% +absolute values of their values that + + + align:start position:0% +absolute values of their values that +make sense i just check if it's negative + + align:start position:0% +make sense i just check if it's negative + + + align:start position:0% +make sense i just check if it's negative +it is i put the positive thing there + + align:start position:0% +it is i put the positive thing there + + + align:start position:0% +it is i put the positive thing there +right okay and then and then i + + align:start position:0% +right okay and then and then i + + + align:start position:0% +right okay and then and then i +stick that array in this build right i + + align:start position:0% +stick that array in this build right i + + + align:start position:0% +stick that array in this build right i +put that + + align:start position:0% +put that + + + align:start position:0% +put that +there right so that'll take some + + align:start position:0% +there right so that'll take some + + + align:start position:0% +there right so that'll take some +whatever this build time is and then i + + align:start position:0% +whatever this build time is and then i + + + align:start position:0% +whatever this build time is and then i +can + + align:start position:0% +can + + + align:start position:0% +can +delete max k times or i can delete max + + align:start position:0% +delete max k times or i can delete max + + + align:start position:0% +delete max k times or i can delete max +some number of times however many things + + align:start position:0% +some number of times however many things + + + align:start position:0% +some number of times however many things +that i need + + align:start position:0% +that i need + + + align:start position:0% +that i need +right that the if i if i want log n + + align:start position:0% +right that the if i if i want log n + + + align:start position:0% +right that the if i if i want log n +highest things i can just + + align:start position:0% +highest things i can just + + + align:start position:0% +highest things i can just +do that log n times right so for this + + align:start position:0% +do that log n times right so for this + + + align:start position:0% +do that log n times right so for this +if i had such a data structure i could + + align:start position:0% +if i had such a data structure i could + + + align:start position:0% +if i had such a data structure i could +do this in one run of this operation + + align:start position:0% +do this in one run of this operation + + + align:start position:0% +do this in one run of this operation +and log in runs of this operation does + + align:start position:0% +and log in runs of this operation does + + + align:start position:0% +and log in runs of this operation does +that make sense i can solve this problem + + align:start position:0% +that make sense i can solve this problem + + + align:start position:0% +that make sense i can solve this problem +reducing to this data structure right + + align:start position:0% +reducing to this data structure right + + + align:start position:0% +reducing to this data structure right +now for a sorted array or a + + align:start position:0% +now for a sorted array or a + + + align:start position:0% +now for a sorted array or a +sat avl tree right this operation kind + + align:start position:0% +sat avl tree right this operation kind + + + align:start position:0% +sat avl tree right this operation kind +of kills me already + + align:start position:0% +of kills me already + + + align:start position:0% +of kills me already +takes m log in time right the nice thing + + align:start position:0% +takes m log in time right the nice thing + + + align:start position:0% +takes m log in time right the nice thing +about a binary heap + + align:start position:0% +about a binary heap + + + align:start position:0% +about a binary heap +is it does this operation in linear time + + align:start position:0% + + + + align:start position:0% + +you will see that on tuesday and it does + + align:start position:0% +you will see that on tuesday and it does + + + align:start position:0% +you will see that on tuesday and it does +this operation + + align:start position:0% +this operation + + + align:start position:0% +this operation +in login time + + align:start position:0% + + + + align:start position:0% + +okay so how what's the running time + + align:start position:0% +okay so how what's the running time + + + align:start position:0% +okay so how what's the running time +if i use a heap to binary heap to + + align:start position:0% +if i use a heap to binary heap to + + + align:start position:0% +if i use a heap to binary heap to +implement this data structure + + align:start position:0% +implement this data structure + + + align:start position:0% +implement this data structure +order of n times order log n + + align:start position:0% +order of n times order log n + + + align:start position:0% +order of n times order log n +times log n how big is log n squared + + align:start position:0% +times log n how big is log n squared + + + align:start position:0% +times log n how big is log n squared +log squared n compared to n + + align:start position:0% +log squared n compared to n + + + align:start position:0% +log squared n compared to n +is smaller right so if i add those two + + align:start position:0% +is smaller right so if i add those two + + + align:start position:0% +is smaller right so if i add those two +running times together it's still linear + + align:start position:0% +running times together it's still linear + + + align:start position:0% +running times together it's still linear +right + + align:start position:0% +right + + + align:start position:0% +right +okay so that's how you solve the first + + align:start position:0% +okay so that's how you solve the first + + + align:start position:0% +okay so that's how you solve the first +problem okay + + align:start position:0% +problem okay + + + align:start position:0% +problem okay +i didn't have to tell you what a binary + + align:start position:0% +i didn't have to tell you what a binary + + + align:start position:0% +i didn't have to tell you what a binary +heap was or how it did what it did all i + + align:start position:0% +heap was or how it did what it did all i + + + align:start position:0% +heap was or how it did what it did all i +needed to tell you was that it did this + + align:start position:0% +needed to tell you was that it did this + + + align:start position:0% +needed to tell you was that it did this +operation in linear time + + align:start position:0% +operation in linear time + + + align:start position:0% +operation in linear time +and it did this operation login type + + align:start position:0% +and it did this operation login type + + + align:start position:0% +and it did this operation login type +okay + + align:start position:0% + + + + align:start position:0% + +yeah all right the magic will be shown + + align:start position:0% +yeah all right the magic will be shown + + + align:start position:0% +yeah all right the magic will be shown +to you on tuesday + + align:start position:0% +to you on tuesday + + + align:start position:0% +to you on tuesday +part b says now suppose fixed computer + + align:start position:0% +part b says now suppose fixed computer + + + align:start position:0% +part b says now suppose fixed computer +is only allowed to write to at most log + + align:start position:0% +is only allowed to write to at most log + + + align:start position:0% +is only allowed to write to at most log +and space + + align:start position:0% +and space + + + align:start position:0% +and space +well okay that's a problem here right + + align:start position:0% +well okay that's a problem here right + + + align:start position:0% +well okay that's a problem here right +because we before we copied over + + align:start position:0% +because we before we copied over + + + align:start position:0% +because we before we copied over +the entire array filtered it out right + + align:start position:0% +the entire array filtered it out right + + + align:start position:0% +the entire array filtered it out right +and then did some operations but we + + align:start position:0% +and then did some operations but we + + + align:start position:0% +and then did some operations but we +couldn't even afford this if we couldn't + + align:start position:0% +couldn't even afford this if we couldn't + + + align:start position:0% +couldn't even afford this if we couldn't +store the whole thing + + align:start position:0% +store the whole thing + + + align:start position:0% +store the whole thing +externally in writable memory right + + align:start position:0% +externally in writable memory right + + + align:start position:0% +externally in writable memory right +okay so we can't do that so in some + + align:start position:0% +okay so we can't do that so in some + + + align:start position:0% +okay so we can't do that so in some +sense this is a more restrictive + + align:start position:0% +sense this is a more restrictive + + + align:start position:0% +sense this is a more restrictive +environment + + align:start position:0% +environment + + + align:start position:0% +environment +right i can do less things + + align:start position:0% +right i can do less things + + + align:start position:0% +right i can do less things +than i could it's a uh it's less + + align:start position:0% +than i could it's a uh it's less + + + align:start position:0% +than i could it's a uh it's less +powerful than my previous situation + + align:start position:0% +powerful than my previous situation + + + align:start position:0% +powerful than my previous situation +where i had as much space as i wanted to + + align:start position:0% +where i had as much space as i wanted to + + + align:start position:0% +where i had as much space as i wanted to +use right + + align:start position:0% +use right + + + align:start position:0% +use right +so it kind of makes sense that + + align:start position:0% +so it kind of makes sense that + + + align:start position:0% +so it kind of makes sense that +i maybe couldn't get + + align:start position:0% +i maybe couldn't get + + + align:start position:0% +i maybe couldn't get +the running time bad that bound that we + + align:start position:0% +the running time bad that bound that we + + + align:start position:0% +the running time bad that bound that we +had before right + + align:start position:0% +had before right + + + align:start position:0% +had before right +maybe i have to sacrifice something + + align:start position:0% +maybe i have to sacrifice something + + + align:start position:0% +maybe i have to sacrifice something +because i'm in a more restrictive + + align:start position:0% +because i'm in a more restrictive + + + align:start position:0% +because i'm in a more restrictive +computational setting right okay + + align:start position:0% +computational setting right okay + + + align:start position:0% +computational setting right okay +now this is something you could solve + + align:start position:0% +now this is something you could solve + + + align:start position:0% +now this is something you could solve +with binary heaps but you don't have to + + align:start position:0% +with binary heaps but you don't have to + + + align:start position:0% +with binary heaps but you don't have to +you could solve it + + align:start position:0% +you could solve it + + + align:start position:0% +you could solve it +with uh scent adl trees + + align:start position:0% + + + + align:start position:0% + +as anyone have an idea of how you could + + align:start position:0% +as anyone have an idea of how you could + + + align:start position:0% +as anyone have an idea of how you could +solve this using a set avl tree + + align:start position:0% +solve this using a set avl tree + + + align:start position:0% +solve this using a set avl tree +i'm limited by my number of mice my + + align:start position:0% +i'm limited by my number of mice my + + + align:start position:0% +i'm limited by my number of mice my +my space is at most log n + + align:start position:0% + + + + align:start position:0% + +yeah all right so how much space does + + align:start position:0% +yeah all right so how much space does + + + align:start position:0% +yeah all right so how much space does +this indial tree take + + align:start position:0% +this indial tree take + + + align:start position:0% +this indial tree take +right space right there's constant + + align:start position:0% +right space right there's constant + + + align:start position:0% +right space right there's constant +number of pointers for each one of these + + align:start position:0% +number of pointers for each one of these + + + align:start position:0% +number of pointers for each one of these +nodes + + align:start position:0% +nodes + + + align:start position:0% +nodes +right and i'm storing in nodes and space + + align:start position:0% +right and i'm storing in nodes and space + + + align:start position:0% +right and i'm storing in nodes and space +right basically every data structure + + align:start position:0% +right basically every data structure + + + align:start position:0% +right basically every data structure +we've shown you + + align:start position:0% +we've shown you + + + align:start position:0% +we've shown you +takes space the order of the things that + + align:start position:0% +takes space the order of the things that + + + align:start position:0% +takes space the order of the things that +we're storing + + align:start position:0% +we're storing + + + align:start position:0% +we're storing +right it's not using additional space it + + align:start position:0% +right it's not using additional space it + + + align:start position:0% +right it's not using additional space it +might take + + align:start position:0% +might take + + + align:start position:0% +might take +more time to do certain things but the + + align:start position:0% +more time to do certain things but the + + + align:start position:0% +more time to do certain things but the +space is + + align:start position:0% +space is + + + align:start position:0% +space is +you know takes the number of items we're + + align:start position:0% +you know takes the number of items we're + + + align:start position:0% +you know takes the number of items we're +storing plus + + align:start position:0% +storing plus + + + align:start position:0% +storing plus +maybe a constant factor right + + align:start position:0% + + + + align:start position:0% + +right so i'm going to draw my input here + + align:start position:0% +right so i'm going to draw my input here + + + align:start position:0% +right so i'm going to draw my input here +which i can only read i can't write + + align:start position:0% +which i can only read i can't write + + + align:start position:0% +which i can only read i can't write +do i give it i'm just going to call it a + + align:start position:0% +do i give it i'm just going to call it a + + + align:start position:0% +do i give it i'm just going to call it a +okay so this is my list + + align:start position:0% + + + + align:start position:0% + +of all the revenger opinions okay i can + + align:start position:0% +of all the revenger opinions okay i can + + + align:start position:0% +of all the revenger opinions okay i can +only read it + + align:start position:0% +only read it + + + align:start position:0% +only read it +but my computer can only write to this + + align:start position:0% +but my computer can only write to this + + + align:start position:0% +but my computer can only write to this +logarithmic amount of space + + align:start position:0% + + + + align:start position:0% + +what can i put in that space + + align:start position:0% + + + + align:start position:0% + +well i can i can certainly put log n + + align:start position:0% +well i can i can certainly put log n + + + align:start position:0% +well i can i can certainly put log n +things in there okay + + align:start position:0% +things in there okay + + + align:start position:0% +things in there okay +so if i'm given that restriction i + + align:start position:0% +so if i'm given that restriction i + + + align:start position:0% +so if i'm given that restriction i +probably want to build a data structure + + align:start position:0% +probably want to build a data structure + + + align:start position:0% +probably want to build a data structure +of that size + + align:start position:0% +of that size + + + align:start position:0% +of that size +right you know containing that number of + + align:start position:0% +right you know containing that number of + + + align:start position:0% +right you know containing that number of +things that make sense + + align:start position:0% +things that make sense + + + align:start position:0% +things that make sense +because what else are you gonna do right + + align:start position:0% + + + + align:start position:0% + +okay so i i gave you an idea maybe we + + align:start position:0% +okay so i i gave you an idea maybe we + + + align:start position:0% +okay so i i gave you an idea maybe we +could use a set avl here + + align:start position:0% +could use a set avl here + + + align:start position:0% +could use a set avl here +right i see a logarithm in my answer + + align:start position:0% +right i see a logarithm in my answer + + + align:start position:0% +right i see a logarithm in my answer +right it's very possible that we might + + align:start position:0% +right it's very possible that we might + + + align:start position:0% +right it's very possible that we might +have + + align:start position:0% +have + + + align:start position:0% +have +you know sorted arrays right or set avl + + align:start position:0% +you know sorted arrays right or set avl + + + align:start position:0% +you know sorted arrays right or set avl +things those + + align:start position:0% +things those + + + align:start position:0% +things those +those things give me a log somewhere in + + align:start position:0% +those things give me a log somewhere in + + + align:start position:0% +those things give me a log somewhere in +my running times right + + align:start position:0% +my running times right + + + align:start position:0% +my running times right +so kind of makes sense that i might have + + align:start position:0% +so kind of makes sense that i might have + + + align:start position:0% +so kind of makes sense that i might have +maybe a set avl tree here why why why + + align:start position:0% +maybe a set avl tree here why why why + + + align:start position:0% +maybe a set avl tree here why why why +would a set avl tree be helpful for me + + align:start position:0% + + + + align:start position:0% + +yeah because it started and you know you + + align:start position:0% +yeah because it started and you know you + + + align:start position:0% +yeah because it started and you know you +have the direct russell order you can + + align:start position:0% +have the direct russell order you can + + + align:start position:0% +have the direct russell order you can +calculate the traversal order + + align:start position:0% +calculate the traversal order + + + align:start position:0% +calculate the traversal order +and insert like anxiety sure i can do + + align:start position:0% +and insert like anxiety sure i can do + + + align:start position:0% +and insert like anxiety sure i can do +all those things but in particular + + align:start position:0% +all those things but in particular + + + align:start position:0% +all those things but in particular +it's going to help me be able to find + + align:start position:0% +it's going to help me be able to find + + + align:start position:0% +it's going to help me be able to find +a large one quickly right if i if i + + align:start position:0% +a large one quickly right if i if i + + + align:start position:0% +a large one quickly right if i if i +kind of uh have a set of things it's + + align:start position:0% +kind of uh have a set of things it's + + + align:start position:0% +kind of uh have a set of things it's +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +and i and i'm maintaining this data + + align:start position:0% +and i and i'm maintaining this data + + + align:start position:0% +and i and i'm maintaining this data +structure by adding things incrementally + + align:start position:0% +structure by adding things incrementally + + + align:start position:0% +structure by adding things incrementally +to it + + align:start position:0% +to it + + + align:start position:0% +to it +right i can find out what the biggest + + align:start position:0% +right i can find out what the biggest + + + align:start position:0% +right i can find out what the biggest +one is + + align:start position:0% +one is + + + align:start position:0% +one is +or the smallest one pretty fast right + + align:start position:0% +or the smallest one pretty fast right + + + align:start position:0% +or the smallest one pretty fast right +and log in time + + align:start position:0% +and log in time + + + align:start position:0% +and log in time +right so if i have log n things in a + + align:start position:0% +right so if i have log n things in a + + + align:start position:0% +right so if i have log n things in a +in a tree here right what's the height + + align:start position:0% +in a tree here right what's the height + + + align:start position:0% +in a tree here right what's the height +of that thing + + align:start position:0% +of that thing + + + align:start position:0% +of that thing +log log n that looks familiar so what + + align:start position:0% +log log n that looks familiar so what + + + align:start position:0% +log log n that looks familiar so what +can i afford i can afford + + align:start position:0% +can i afford i can afford + + + align:start position:0% +can i afford i can afford +a linear number of op set avl tree + + align:start position:0% +a linear number of op set avl tree + + + align:start position:0% +a linear number of op set avl tree +operations on this data structure right + + align:start position:0% +operations on this data structure right + + + align:start position:0% +operations on this data structure right +okay you had a question okay i'm sorry + + align:start position:0% +okay you had a question okay i'm sorry + + + align:start position:0% +okay you had a question okay i'm sorry +yeah um for there'll be an + + align:start position:0% +yeah um for there'll be an + + + align:start position:0% +yeah um for there'll be an +avl tree does it have to be a bts tree + + align:start position:0% +avl tree does it have to be a bts tree + + + align:start position:0% +avl tree does it have to be a bts tree +it's + + align:start position:0% +it's + + + align:start position:0% +it's +uh bts bst + + align:start position:0% +uh bts bst + + + align:start position:0% +uh bts bst +right so when i talk about uh someone + + align:start position:0% +right so when i talk about uh someone + + + align:start position:0% +right so when i talk about uh someone +likes korean k-pop + + align:start position:0% +likes korean k-pop + + + align:start position:0% +likes korean k-pop +okay uh so uh + + align:start position:0% +okay uh so uh + + + align:start position:0% +okay uh so uh +bst but in natural kind of in + + align:start position:0% +bst but in natural kind of in + + + align:start position:0% +bst but in natural kind of in +the lingo that you're probably used to + + align:start position:0% +the lingo that you're probably used to + + + align:start position:0% +the lingo that you're probably used to +hearing in other contexts + + align:start position:0% +hearing in other contexts + + + align:start position:0% +hearing in other contexts +what we mean in this class is a set adl + + align:start position:0% +what we mean in this class is a set adl + + + align:start position:0% +what we mean in this class is a set adl +tree right + + align:start position:0% +tree right + + + align:start position:0% +tree right +now sometimes what people + + align:start position:0% +now sometimes what people + + + align:start position:0% +now sometimes what people +refer to as a binary search tree doesn't + + align:start position:0% +refer to as a binary search tree doesn't + + + align:start position:0% +refer to as a binary search tree doesn't +have balance + + align:start position:0% +have balance + + + align:start position:0% +have balance +semantics right so we might call in this + + align:start position:0% +semantics right so we might call in this + + + align:start position:0% +semantics right so we might call in this +class a set binary tree + + align:start position:0% +class a set binary tree + + + align:start position:0% +class a set binary tree +right but really + + align:start position:0% +right but really + + + align:start position:0% +right but really +they're useful because they're balanced + + align:start position:0% +they're useful because they're balanced + + + align:start position:0% +they're useful because they're balanced +so we're going to usually just assume + + align:start position:0% +so we're going to usually just assume + + + align:start position:0% +so we're going to usually just assume +that we're + + align:start position:0% +that we're + + + align:start position:0% +that we're +talking about balance things here now a + + align:start position:0% +talking about balance things here now a + + + align:start position:0% +talking about balance things here now a +set avl tree has these binary search + + align:start position:0% +set avl tree has these binary search + + + align:start position:0% +set avl tree has these binary search +tree semantics + + align:start position:0% +tree semantics + + + align:start position:0% +tree semantics +where the keys are ordered these items + + align:start position:0% +where the keys are ordered these items + + + align:start position:0% +where the keys are ordered these items +have keys and they're ordered it's a set + + align:start position:0% +have keys and they're ordered it's a set + + + align:start position:0% +have keys and they're ordered it's a set +interface right + + align:start position:0% +interface right + + + align:start position:0% +interface right +whereas we also presented to a sequence + + align:start position:0% +whereas we also presented to a sequence + + + align:start position:0% +whereas we also presented to a sequence +interface + + align:start position:0% +interface + + + align:start position:0% +interface +right for which these these things don't + + align:start position:0% +right for which these these things don't + + + align:start position:0% +right for which these these things don't +even have keys how could i + + align:start position:0% +even have keys how could i + + + align:start position:0% +even have keys how could i +store set semantics there right so but + + align:start position:0% +store set semantics there right so but + + + align:start position:0% +store set semantics there right so but +that's the distinction that we mean when + + align:start position:0% +that's the distinction that we mean when + + + align:start position:0% +that's the distinction that we mean when +we say + + align:start position:0% +we say + + + align:start position:0% +we say +uh binary search tree versus + + align:start position:0% +uh binary search tree versus + + + align:start position:0% +uh binary search tree versus +really a set avl tree versus yeah so if + + align:start position:0% +really a set avl tree versus yeah so if + + + align:start position:0% +really a set avl tree versus yeah so if +we're going to make an avl tree out of + + align:start position:0% +we're going to make an avl tree out of + + + align:start position:0% +we're going to make an avl tree out of +this would that mean that like + + align:start position:0% +this would that mean that like + + + align:start position:0% +this would that mean that like +we when we make a node we tell it like + + align:start position:0% +we when we make a node we tell it like + + + align:start position:0% +we when we make a node we tell it like +we are keying on the absolute value + + align:start position:0% +we are keying on the absolute value + + + align:start position:0% +we are keying on the absolute value +okay so when you're uh + + align:start position:0% +okay so when you're uh + + + align:start position:0% +okay so when you're uh +making a set to avl tree you got to tell + + align:start position:0% +making a set to avl tree you got to tell + + + align:start position:0% +making a set to avl tree you got to tell +us what + + align:start position:0% +us what + + + align:start position:0% +us what +if you're storing objects you got to + + align:start position:0% +if you're storing objects you got to + + + align:start position:0% +if you're storing objects you got to +tell me what their key is right if + + align:start position:0% +tell me what their key is right if + + + align:start position:0% +tell me what their key is right if +you're just storing some numbers + + align:start position:0% +you're just storing some numbers + + + align:start position:0% +you're just storing some numbers +like what i'm doing here right now this + + align:start position:0% +like what i'm doing here right now this + + + align:start position:0% +like what i'm doing here right now this +isn't a set avl tree right but if i'm + + align:start position:0% +isn't a set avl tree right but if i'm + + + align:start position:0% +isn't a set avl tree right but if i'm +just storing numbers + + align:start position:0% +just storing numbers + + + align:start position:0% +just storing numbers +i have to tell you the items that i'm + + align:start position:0% +i have to tell you the items that i'm + + + align:start position:0% +i have to tell you the items that i'm +storing are the keys + + align:start position:0% +storing are the keys + + + align:start position:0% +storing are the keys +okay and then everything follows right + + align:start position:0% +okay and then everything follows right + + + align:start position:0% +okay and then everything follows right +but if you've got an object that you're + + align:start position:0% +but if you've got an object that you're + + + align:start position:0% +but if you've got an object that you're +trying to sort like + + align:start position:0% +trying to sort like + + + align:start position:0% +trying to sort like +the students in this room you got a lot + + align:start position:0% +the students in this room you got a lot + + + align:start position:0% +the students in this room you got a lot +of properties + + align:start position:0% +of properties + + + align:start position:0% +of properties +right i want to all the uh + + align:start position:0% +right i want to all the uh + + + align:start position:0% +right i want to all the uh +the people with phone number right + + align:start position:0% +the people with phone number right + + + align:start position:0% +the people with phone number right +maybe i want to key you on phone number + + align:start position:0% +maybe i want to key you on phone number + + + align:start position:0% +maybe i want to key you on phone number +for some reason that's going to help me + + align:start position:0% +for some reason that's going to help me + + + align:start position:0% +for some reason that's going to help me +find out where you live i don't know + + align:start position:0% +find out where you live i don't know + + + align:start position:0% +find out where you live i don't know +this is getting i don't want to go there + + align:start position:0% +this is getting i don't want to go there + + + align:start position:0% +this is getting i don't want to go there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so but if i if i give you a set to avl + + align:start position:0% +so but if i if i give you a set to avl + + + align:start position:0% +so but if i if i give you a set to avl +tree + + align:start position:0% +tree + + + align:start position:0% +tree +i got to tell you what it's keyed on if + + align:start position:0% +i got to tell you what it's keyed on if + + + align:start position:0% +i got to tell you what it's keyed on if +i give you a sequence avl tree + + align:start position:0% +i give you a sequence avl tree + + + align:start position:0% +i give you a sequence avl tree +right it's obvious what my traversal + + align:start position:0% +right it's obvious what my traversal + + + align:start position:0% +right it's obvious what my traversal +order is going to be because i'm giving + + align:start position:0% +order is going to be because i'm giving + + + align:start position:0% +order is going to be because i'm giving +you a sequence + + align:start position:0% +you a sequence + + + align:start position:0% +you a sequence +right that's what the input gate was + + align:start position:0% +right that's what the input gate was + + + align:start position:0% +right that's what the input gate was +right + + align:start position:0% +right + + + align:start position:0% +right +does that make sense all right so i've + + align:start position:0% +does that make sense all right so i've + + + align:start position:0% +does that make sense all right so i've +got this + + align:start position:0% +got this + + + align:start position:0% +got this +set avl tree of size log n + + align:start position:0% +set avl tree of size log n + + + align:start position:0% +set avl tree of size log n +what should it be keyed by + + align:start position:0% +what should it be keyed by + + + align:start position:0% +what should it be keyed by +absolute value of their preference right + + align:start position:0% +absolute value of their preference right + + + align:start position:0% +absolute value of their preference right +or of their + + align:start position:0% +or of their + + + align:start position:0% +or of their +opinion i don't remember what this is + + align:start position:0% +opinion i don't remember what this is + + + align:start position:0% +opinion i don't remember what this is +called so + + align:start position:0% +called so + + + align:start position:0% +called so +but i what log n things do i put in here + + align:start position:0% + + + + align:start position:0% + +i don't know i i don't know anything + + align:start position:0% +i don't know i i don't know anything + + + align:start position:0% +i don't know i i don't know anything +about these things + + align:start position:0% +about these things + + + align:start position:0% +about these things +what makes one better than another right + + align:start position:0% +what makes one better than another right + + + align:start position:0% +what makes one better than another right +let's just put the first log in things + + align:start position:0% +let's just put the first log in things + + + align:start position:0% +let's just put the first log in things +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +all right what could that + + align:start position:0% + + + + align:start position:0% + +tell me now i've put this thing in it + + align:start position:0% +tell me now i've put this thing in it + + + align:start position:0% +tell me now i've put this thing in it +how long did that take + + align:start position:0% + + + + align:start position:0% + +log n times log log n + + align:start position:0% +log n times log log n + + + align:start position:0% +log n times log log n +time right but that's much less than our + + align:start position:0% +time right but that's much less than our + + + align:start position:0% +time right but that's much less than our +running time right so + + align:start position:0% +running time right so + + + align:start position:0% +running time right so +that we're looking for so i don't really + + align:start position:0% +that we're looking for so i don't really + + + align:start position:0% +that we're looking for so i don't really +care right + + align:start position:0% +care right + + + align:start position:0% +care right +i mean i want you to say how long it + + align:start position:0% +i mean i want you to say how long it + + + align:start position:0% +i mean i want you to say how long it +took + + align:start position:0% +took + + + align:start position:0% +took +but for my purposes i know that it's + + align:start position:0% +but for my purposes i know that it's + + + align:start position:0% +but for my purposes i know that it's +lower than the running time i'm looking + + align:start position:0% +lower than the running time i'm looking + + + align:start position:0% +lower than the running time i'm looking +for + + align:start position:0% +for + + + align:start position:0% +for +so and i did that operation once i don't + + align:start position:0% +so and i did that operation once i don't + + + align:start position:0% +so and i did that operation once i don't +really care about it anymore + + align:start position:0% +really care about it anymore + + + align:start position:0% +really care about it anymore +okay yep how did you get log n because + + align:start position:0% +okay yep how did you get log n because + + + align:start position:0% +okay yep how did you get log n because +the number of things i'm storing in this + + align:start position:0% +the number of things i'm storing in this + + + align:start position:0% +the number of things i'm storing in this +thing is log n + + align:start position:0% +thing is log n + + + align:start position:0% +thing is log n +and so if i pattern match + + align:start position:0% +and so if i pattern match + + + align:start position:0% +and so if i pattern match +the build time of an avl tree and i + + align:start position:0% +the build time of an avl tree and i + + + align:start position:0% +the build time of an avl tree and i +stick log n in there + + align:start position:0% +stick log n in there + + + align:start position:0% +stick log n in there +right then it's log n times log log n + + align:start position:0% +right then it's log n times log log n + + + align:start position:0% +right then it's log n times log log n +gotcha okay so is that for one iteration + + align:start position:0% +gotcha okay so is that for one iteration + + + align:start position:0% +gotcha okay so is that for one iteration +well right now i've just built this + + align:start position:0% +well right now i've just built this + + + align:start position:0% +well right now i've just built this +thing right + + align:start position:0% +thing right + + + align:start position:0% +thing right +maybe i uh well i just built it once + + align:start position:0% +maybe i uh well i just built it once + + + align:start position:0% +maybe i uh well i just built it once +uh i'm asserting too that maybe i don't + + align:start position:0% +uh i'm asserting too that maybe i don't + + + align:start position:0% +uh i'm asserting too that maybe i don't +need to build it again + + align:start position:0% +need to build it again + + + align:start position:0% +need to build it again +right what could i do instead so right + + align:start position:0% +right what could i do instead so right + + + align:start position:0% +right what could i do instead so right +now + + align:start position:0% +now + + + align:start position:0% +now +i know i haven't filtered my data at all + + align:start position:0% +i know i haven't filtered my data at all + + + align:start position:0% +i know i haven't filtered my data at all +right i'm just storing these things in + + align:start position:0% +right i'm just storing these things in + + + align:start position:0% +right i'm just storing these things in +sorted order in some way + + align:start position:0% +sorted order in some way + + + align:start position:0% +sorted order in some way +right what can i do + + align:start position:0% +right what can i do + + + align:start position:0% +right what can i do +to maybe start processing the rest of + + align:start position:0% +to maybe start processing the rest of + + + align:start position:0% +to maybe start processing the rest of +the data + + align:start position:0% +the data + + + align:start position:0% +the data +yeah well i didn't like try to scroll + + align:start position:0% +yeah well i didn't like try to scroll + + + align:start position:0% +yeah well i didn't like try to scroll +through + + align:start position:0% +through + + + align:start position:0% +through +the list a and try to like remind + + align:start position:0% +the list a and try to like remind + + + align:start position:0% +the list a and try to like remind +someone that's bigger than + + align:start position:0% +someone that's bigger than + + + align:start position:0% +someone that's bigger than +like try to keep the maximum ah + + align:start position:0% +like try to keep the maximum ah + + + align:start position:0% +like try to keep the maximum ah +kind of sweep this guy over inserting + + align:start position:0% +kind of sweep this guy over inserting + + + align:start position:0% +kind of sweep this guy over inserting +things + + align:start position:0% +things + + + align:start position:0% +things +and always maintaining you know if i do + + align:start position:0% +and always maintaining you know if i do + + + align:start position:0% +and always maintaining you know if i do +that and i keep sticking things in + + align:start position:0% +that and i keep sticking things in + + + align:start position:0% +that and i keep sticking things in +i'll have this sorted thing at the end + + align:start position:0% +i'll have this sorted thing at the end + + + align:start position:0% +i'll have this sorted thing at the end +and now i can just read off the + + align:start position:0% +and now i can just read off the + + + align:start position:0% +and now i can just read off the +biggest k things right however + + align:start position:0% +biggest k things right however + + + align:start position:0% +biggest k things right however +as i'm inserting things across here + + align:start position:0% +as i'm inserting things across here + + + align:start position:0% +as i'm inserting things across here +my thing's growing i'll just delete this + + align:start position:0% +my thing's growing i'll just delete this + + + align:start position:0% +my thing's growing i'll just delete this +oh delete small is fun + + align:start position:0% +oh delete small is fun + + + align:start position:0% +oh delete small is fun +i like that idea right basically yeah + + align:start position:0% +i like that idea right basically yeah + + + align:start position:0% +i like that idea right basically yeah +basically replace it right so + + align:start position:0% +basically replace it right so + + + align:start position:0% +basically replace it right so +what i'm going to do here's a proposal + + align:start position:0% +what i'm going to do here's a proposal + + + align:start position:0% +what i'm going to do here's a proposal +we're going to take the next guy stick + + align:start position:0% +we're going to take the next guy stick + + + align:start position:0% +we're going to take the next guy stick +it in + + align:start position:0% +it in + + + align:start position:0% +it in +awesome which one don't i care about now + + align:start position:0% +awesome which one don't i care about now + + + align:start position:0% +awesome which one don't i care about now +the smallest one there so kick the + + align:start position:0% +the smallest one there so kick the + + + align:start position:0% +the smallest one there so kick the +smallest one out + + align:start position:0% +smallest one out + + + align:start position:0% +smallest one out +now this one that i stuck in may be the + + align:start position:0% +now this one that i stuck in may be the + + + align:start position:0% +now this one that i stuck in may be the +smallest + + align:start position:0% +smallest + + + align:start position:0% +smallest +right so i just kind of passed it + + align:start position:0% +right so i just kind of passed it + + + align:start position:0% +right so i just kind of passed it +through this thing but how long did that + + align:start position:0% +through this thing but how long did that + + + align:start position:0% +through this thing but how long did that +take me + + align:start position:0% + + + + align:start position:0% + +it took me the height of this tree + + align:start position:0% +it took me the height of this tree + + + align:start position:0% +it took me the height of this tree +what's the height of the tree log log n + + align:start position:0% +what's the height of the tree log log n + + + align:start position:0% +what's the height of the tree log log n +right so i put one in + + align:start position:0% +right so i put one in + + + align:start position:0% +right so i put one in +i pop one out that's the smallest right + + align:start position:0% +i pop one out that's the smallest right + + + align:start position:0% +i pop one out that's the smallest right +and i keep doing that all the way down + + align:start position:0% +and i keep doing that all the way down + + + align:start position:0% +and i keep doing that all the way down +the thing how long did that take + + align:start position:0% +the thing how long did that take + + + align:start position:0% +the thing how long did that take +yeah i'm processing n minus log n + + align:start position:0% +yeah i'm processing n minus log n + + + align:start position:0% +yeah i'm processing n minus log n +things which is basically n right + + align:start position:0% +things which is basically n right + + + align:start position:0% +things which is basically n right +and each one of those operations took me + + align:start position:0% +and each one of those operations took me + + + align:start position:0% +and each one of those operations took me +height of the tree time + + align:start position:0% +height of the tree time + + + align:start position:0% +height of the tree time +so that gives me the running time that + + align:start position:0% +so that gives me the running time that + + + align:start position:0% +so that gives me the running time that +we're looking for + + align:start position:0% +we're looking for + + + align:start position:0% +we're looking for +and log log + + align:start position:0% +and log log + + + align:start position:0% +and log log +yeah it's like recognition of like a + + align:start position:0% +yeah it's like recognition of like a + + + align:start position:0% +yeah it's like recognition of like a +slide yeah it's a kind of a sliding + + align:start position:0% +slide yeah it's a kind of a sliding + + + align:start position:0% +slide yeah it's a kind of a sliding +window technique you may have + + align:start position:0% +window technique you may have + + + align:start position:0% +window technique you may have +been using one recently + + align:start position:0% +been using one recently + + + align:start position:0% +been using one recently +okay everyone okay with this yeah let me + + align:start position:0% +okay everyone okay with this yeah let me + + + align:start position:0% +okay everyone okay with this yeah let me +just + + align:start position:0% +just + + + align:start position:0% +just +remember the context that we're talking + + align:start position:0% +remember the context that we're talking + + + align:start position:0% +remember the context that we're talking +about is log + + align:start position:0% +about is log + + + align:start position:0% +about is log +log n like tree and like what where so + + align:start position:0% +log n like tree and like what where so + + + align:start position:0% +log n like tree and like what where so +this thing + + align:start position:0% +this thing + + + align:start position:0% +this thing +the size of this thing is log log n yeah + + align:start position:0% +the size of this thing is log log n yeah + + + align:start position:0% +the size of this thing is log log n yeah +i mean sorry + + align:start position:0% +i mean sorry + + + align:start position:0% +i mean sorry +log n and the height of this thing is + + align:start position:0% +log n and the height of this thing is + + + align:start position:0% +log n and the height of this thing is +log of + + align:start position:0% +log of + + + align:start position:0% +log of +the size + + align:start position:0% + + + + align:start position:0% + +in relation to like our little like + + align:start position:0% +in relation to like our little like + + + align:start position:0% +in relation to like our little like +login size + + align:start position:0% +login size + + + align:start position:0% +login size +like right there sticking this full of + + align:start position:0% +like right there sticking this full of + + + align:start position:0% +like right there sticking this full of +small log log entries or like like no so + + align:start position:0% +small log log entries or like like no so + + + align:start position:0% +small log log entries or like like no so +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +i'm taking this stuff there's no + + align:start position:0% +i'm taking this stuff there's no + + + align:start position:0% +i'm taking this stuff there's no +intermediate data structure here + + align:start position:0% +intermediate data structure here + + + align:start position:0% +intermediate data structure here +i'm just sticking all these things into + + align:start position:0% +i'm just sticking all these things into + + + align:start position:0% +i'm just sticking all these things into +a via + + align:start position:0% +a via + + + align:start position:0% +a via +bsta i mean a set abl yep + + align:start position:0% +bsta i mean a set abl yep + + + align:start position:0% +bsta i mean a set abl yep +into one set avl right of size log n + + align:start position:0% +into one set avl right of size log n + + + align:start position:0% +into one set avl right of size log n +i'm sticking a guy in popping the + + align:start position:0% +i'm sticking a guy in popping the + + + align:start position:0% +i'm sticking a guy in popping the +worst guy out right going through all + + align:start position:0% +worst guy out right going through all + + + align:start position:0% +worst guy out right going through all +the things + + align:start position:0% +the things + + + align:start position:0% +the things +i need to make sure when i'm sticking it + + align:start position:0% +i need to make sure when i'm sticking it + + + align:start position:0% +i need to make sure when i'm sticking it +in i'm + + align:start position:0% +in i'm + + + align:start position:0% +in i'm +you know keeping track of which revenger + + align:start position:0% +you know keeping track of which revenger + + + align:start position:0% +you know keeping track of which revenger +it is and that i'm taking the absolute + + align:start position:0% +it is and that i'm taking the absolute + + + align:start position:0% +it is and that i'm taking the absolute +value and all those + + align:start position:0% +value and all those + + + align:start position:0% +value and all those +you know nitty-gritty kind of things but + + align:start position:0% +you know nitty-gritty kind of things but + + + align:start position:0% +you know nitty-gritty kind of things but +that's the basic idea right + + align:start position:0% +that's the basic idea right + + + align:start position:0% +that's the basic idea right +i'm just taking this i'm sliding the + + align:start position:0% +i'm just taking this i'm sliding the + + + align:start position:0% +i'm just taking this i'm sliding the +window in + + align:start position:0% +window in + + + align:start position:0% +window in +putting something in taking something + + align:start position:0% +putting something in taking something + + + align:start position:0% +putting something in taking something +out that may or may not probably is not + + align:start position:0% +out that may or may not probably is not + + + align:start position:0% +out that may or may not probably is not +the + + align:start position:0% +the + + + align:start position:0% +the +same thing and at the end of this + + align:start position:0% +same thing and at the end of this + + + align:start position:0% +same thing and at the end of this +procedure + + align:start position:0% +procedure + + + align:start position:0% +procedure +right the invariant i'm i'm maintaining + + align:start position:0% +right the invariant i'm i'm maintaining + + + align:start position:0% +right the invariant i'm i'm maintaining +here is that my thing + + align:start position:0% +here is that my thing + + + align:start position:0% +here is that my thing +always has the k largest opinions + + align:start position:0% +always has the k largest opinions + + + align:start position:0% +always has the k largest opinions +of the ones that i've processed so far + + align:start position:0% +of the ones that i've processed so far + + + align:start position:0% +of the ones that i've processed so far +right that's obviously true at the + + align:start position:0% +right that's obviously true at the + + + align:start position:0% +right that's obviously true at the +beginning when i build this thing + + align:start position:0% +beginning when i build this thing + + + align:start position:0% +beginning when i build this thing +and when i get to the end i've processed + + align:start position:0% +and when i get to the end i've processed + + + align:start position:0% +and when i get to the end i've processed +all the things + + align:start position:0% +all the things + + + align:start position:0% +all the things +so and this has size log n and so + + align:start position:0% +so and this has size log n and so + + + align:start position:0% +so and this has size log n and so +i have the log n largest + + align:start position:0% +i have the log n largest + + + align:start position:0% +i have the log n largest +like highest extremist opinions + + align:start position:0% +like highest extremist opinions + + + align:start position:0% +like highest extremist opinions +and then i can just do an inorder + + align:start position:0% +and then i can just do an inorder + + + align:start position:0% +and then i can just do an inorder +traversal of this thing and read + + align:start position:0% +traversal of this thing and read + + + align:start position:0% +traversal of this thing and read +and return does that make sense and i've + + align:start position:0% +and return does that make sense and i've + + + align:start position:0% +and return does that make sense and i've +only used + + align:start position:0% +only used + + + align:start position:0% +only used +logarithmic space + + align:start position:0% + + + + align:start position:0% + +okay yeah so i don't get it are all the + + align:start position:0% +okay yeah so i don't get it are all the + + + align:start position:0% +okay yeah so i don't get it are all the +opinions in that uh + + align:start position:0% +opinions in that uh + + + align:start position:0% +opinions in that uh +are all the opinions in that avl tree + + align:start position:0% +are all the opinions in that avl tree + + + align:start position:0% +are all the opinions in that avl tree +all of these opinions are in the abl + + align:start position:0% +all of these opinions are in the abl + + + align:start position:0% +all of these opinions are in the abl +tree + + align:start position:0% +tree + + + align:start position:0% +tree +and at ever at some point + + align:start position:0% +and at ever at some point + + + align:start position:0% +and at ever at some point +i will insert every + + align:start position:0% +i will insert every + + + align:start position:0% +i will insert every +opinion into this abl tree but i'll + + align:start position:0% +opinion into this abl tree but i'll + + + align:start position:0% +opinion into this abl tree but i'll +be removing the ones that i don't care + + align:start position:0% +be removing the ones that i don't care + + + align:start position:0% +be removing the ones that i don't care +about as i go + + align:start position:0% +about as i go + + + align:start position:0% +about as i go +does that make sense i'm always + + align:start position:0% +does that make sense i'm always + + + align:start position:0% +does that make sense i'm always +maintaining the + + align:start position:0% +maintaining the + + + align:start position:0% +maintaining the +the invariant that this thing before i + + align:start position:0% +the invariant that this thing before i + + + align:start position:0% +the invariant that this thing before i +insert something + + align:start position:0% +insert something + + + align:start position:0% +insert something +has exactly log n items in it and then + + align:start position:0% +has exactly log n items in it and then + + + align:start position:0% +has exactly log n items in it and then +i'm maintaining that invariant + + align:start position:0% +i'm maintaining that invariant + + + align:start position:0% +i'm maintaining that invariant +by sticking one in taking one out oh + + align:start position:0% +by sticking one in taking one out oh + + + align:start position:0% +by sticking one in taking one out oh +okay so then which one are you + + align:start position:0% +okay so then which one are you + + + align:start position:0% +okay so then which one are you +always the min right because i'm wanting + + align:start position:0% +always the min right because i'm wanting + + + align:start position:0% +always the min right because i'm wanting +the the largest ones + + align:start position:0% +the the largest ones + + + align:start position:0% +the the largest ones +and the mid by absolute value but yeah + + align:start position:0% +and the mid by absolute value but yeah + + + align:start position:0% +and the mid by absolute value but yeah +so i'm keying by the absolute value of + + align:start position:0% +so i'm keying by the absolute value of + + + align:start position:0% +so i'm keying by the absolute value of +these opinions + + align:start position:0% + + + + align:start position:0% + +total run time here right it's + + align:start position:0% +total run time here right it's + + + align:start position:0% +total run time here right it's +bookkeeping right + + align:start position:0% +bookkeeping right + + + align:start position:0% +bookkeeping right +so it took me + + align:start position:0% + + + + align:start position:0% + +a log n times log + + align:start position:0% +a log n times log + + + align:start position:0% +a log n times log +log and time to build this data + + align:start position:0% +log and time to build this data + + + align:start position:0% +log and time to build this data +structure at the beginning + + align:start position:0% +structure at the beginning + + + align:start position:0% +structure at the beginning +right plus n times + + align:start position:0% +right plus n times + + + align:start position:0% +right plus n times +log log n + + align:start position:0% +log log n + + + align:start position:0% +log log n +i did you know basically n operation + + align:start position:0% +i did you know basically n operation + + + align:start position:0% +i did you know basically n operation +asymptotically and + + align:start position:0% +asymptotically and + + + align:start position:0% +asymptotically and +operations this way it's actually n + + align:start position:0% +operations this way it's actually n + + + align:start position:0% +operations this way it's actually n +minus log n + + align:start position:0% +minus log n + + + align:start position:0% +minus log n +operations right and each one of those + + align:start position:0% +operations right and each one of those + + + align:start position:0% +operations right and each one of those +operations tree operations + + align:start position:0% +operations tree operations + + + align:start position:0% +operations tree operations +you know doing one insert one delete + + align:start position:0% +you know doing one insert one delete + + + align:start position:0% +you know doing one insert one delete +each one of those + + align:start position:0% +each one of those + + + align:start position:0% +each one of those +took the height of the tree time and so + + align:start position:0% +took the height of the tree time and so + + + align:start position:0% +took the height of the tree time and so +this is that good + + align:start position:0% +this is that good + + + align:start position:0% +this is that good +yeah if instead of blind we just insert + + align:start position:0% +yeah if instead of blind we just insert + + + align:start position:0% +yeah if instead of blind we just insert +and do we + + align:start position:0% +and do we + + + align:start position:0% +and do we +do a comparison and then so the in + + align:start position:0% +do a comparison and then so the in + + + align:start position:0% +do a comparison and then so the in +inserting and deleting + + align:start position:0% +inserting and deleting + + + align:start position:0% +inserting and deleting +uh a set avl tree is actually doing + + align:start position:0% +uh a set avl tree is actually doing + + + align:start position:0% +uh a set avl tree is actually doing +comparisons within its data structure + + align:start position:0% +comparisons within its data structure + + + align:start position:0% +comparisons within its data structure +just compare with the name sure you + + align:start position:0% +just compare with the name sure you + + + align:start position:0% +just compare with the name sure you +could do that + + align:start position:0% +could do that + + + align:start position:0% +could do that +right right so you could i could do it + + align:start position:0% +right right so you could i could do it + + + align:start position:0% +right right so you could i could do it +the other way right + + align:start position:0% +the other way right + + + align:start position:0% +the other way right +i could remove the smallest element here + + align:start position:0% +i could remove the smallest element here + + + align:start position:0% +i could remove the smallest element here +to start with + + align:start position:0% +to start with + + + align:start position:0% +to start with +right and then i compare it with this + + align:start position:0% +right and then i compare it with this + + + align:start position:0% +right and then i compare it with this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +and then whichever is bigger i stick it + + align:start position:0% +and then whichever is bigger i stick it + + + align:start position:0% +and then whichever is bigger i stick it +back in + + align:start position:0% +back in + + + align:start position:0% +back in +same thing right it's just am i doing + + align:start position:0% +same thing right it's just am i doing + + + align:start position:0% +same thing right it's just am i doing +the delete first and then + + align:start position:0% +the delete first and then + + + align:start position:0% +the delete first and then +then the insertion or i'm doing the + + align:start position:0% +then the insertion or i'm doing the + + + align:start position:0% +then the insertion or i'm doing the +insertion first and then the deletion + + align:start position:0% +insertion first and then the deletion + + + align:start position:0% +insertion first and then the deletion +any other questions lots of questions + + align:start position:0% +any other questions lots of questions + + + align:start position:0% +any other questions lots of questions +all right well i'm probably gonna have + + align:start position:0% +all right well i'm probably gonna have + + + align:start position:0% +all right well i'm probably gonna have +to skip the problem + + align:start position:0% +to skip the problem + + + align:start position:0% +to skip the problem +uh we're gonna move on to uh c + + align:start position:0% +uh we're gonna move on to uh c + + + align:start position:0% +uh we're gonna move on to uh c +s so now s c l r + + align:start position:0% +s so now s c l r + + + align:start position:0% +s so now s c l r +all right what's the reference here + + align:start position:0% + + + + align:start position:0% + +yeah clrs right so these are four + + align:start position:0% +yeah clrs right so these are four + + + align:start position:0% +yeah clrs right so these are four +academics who wrote a popular textbook + + align:start position:0% +academics who wrote a popular textbook + + + align:start position:0% +academics who wrote a popular textbook +in computer science + + align:start position:0% +in computer science + + + align:start position:0% +in computer science +uh okay this is the same kind of k kind + + align:start position:0% +uh okay this is the same kind of k kind + + + align:start position:0% +uh okay this is the same kind of k kind +of thing okay + + align:start position:0% +of thing okay + + + align:start position:0% +of thing okay +they found k first editions and they + + align:start position:0% +they found k first editions and they + + + align:start position:0% +they found k first editions and they +want to auction them off + + align:start position:0% +want to auction them off + + + align:start position:0% +want to auction them off +uh people can go on to their website + + align:start position:0% +uh people can go on to their website + + + align:start position:0% +uh people can go on to their website +they have a bitter id + + align:start position:0% +they have a bitter id + + + align:start position:0% +they have a bitter id +it's a unique identifier right and they + + align:start position:0% +it's a unique identifier right and they + + + align:start position:0% +it's a unique identifier right and they +can place a bid + + align:start position:0% +can place a bid + + + align:start position:0% +can place a bid +for one of these books right and + + align:start position:0% +for one of these books right and + + + align:start position:0% +for one of these books right and +they can change it during the bidding + + align:start position:0% +they can change it during the bidding + + + align:start position:0% +they can change it during the bidding +period but + + align:start position:0% +period but + + + align:start position:0% +period but +you know at the end of the bidding + + align:start position:0% +you know at the end of the bidding + + + align:start position:0% +you know at the end of the bidding +period the + + align:start position:0% +period the + + + align:start position:0% +period the +academics want to know who the uh + + align:start position:0% +academics want to know who the uh + + + align:start position:0% +academics want to know who the uh +you know what is the expected revenue + + align:start position:0% +you know what is the expected revenue + + + align:start position:0% +you know what is the expected revenue +i'll get by selling to the k highest + + align:start position:0% +i'll get by selling to the k highest + + + align:start position:0% +i'll get by selling to the k highest +bidders does that make sense + + align:start position:0% + + + + align:start position:0% + +yeah okay so + + align:start position:0% +yeah okay so + + + align:start position:0% +yeah okay so +note that before i + + align:start position:0% +note that before i + + + align:start position:0% +note that before i +build this data structure i know what k + + align:start position:0% +build this data structure i know what k + + + align:start position:0% +build this data structure i know what k +is k is a fixed thing + + align:start position:0% +is k is a fixed thing + + + align:start position:0% +is k is a fixed thing +right right because my my running time + + align:start position:0% +right right because my my running time + + + align:start position:0% +right right because my my running time +of this get revenue + + align:start position:0% +of this get revenue + + + align:start position:0% +of this get revenue +depends on this k it's not an input to + + align:start position:0% +depends on this k it's not an input to + + + align:start position:0% +depends on this k it's not an input to +that operation + + align:start position:0% +that operation + + + align:start position:0% +that operation +right so k is kind of i don't know what + + align:start position:0% +right so k is kind of i don't know what + + + align:start position:0% +right so k is kind of i don't know what +it is + + align:start position:0% +it is + + + align:start position:0% +it is +a priori it could be n over 2 it could + + align:start position:0% +a priori it could be n over 2 it could + + + align:start position:0% +a priori it could be n over 2 it could +be log n + + align:start position:0% +be log n + + + align:start position:0% +be log n +right it could be 1 + + align:start position:0% +right it could be 1 + + + align:start position:0% +right it could be 1 +right but the data structure i build + + align:start position:0% +right but the data structure i build + + + align:start position:0% +right but the data structure i build +needs to satisfy these running time + + align:start position:0% +needs to satisfy these running time + + + align:start position:0% +needs to satisfy these running time +properties no matter what choice okay + + align:start position:0% +properties no matter what choice okay + + + align:start position:0% +properties no matter what choice okay +that the academics told me does that + + align:start position:0% +that the academics told me does that + + + align:start position:0% +that the academics told me does that +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +okay so what i need to do is + + align:start position:0% +okay so what i need to do is + + + align:start position:0% +okay so what i need to do is +as as time is going on people are + + align:start position:0% +as as time is going on people are + + + align:start position:0% +as as time is going on people are +placing new bids and updating their bids + + align:start position:0% +placing new bids and updating their bids + + + align:start position:0% +placing new bids and updating their bids +right + + align:start position:0% +right + + + align:start position:0% +right +and you know those updates can take + + align:start position:0% +and you know those updates can take + + + align:start position:0% +and you know those updates can take +longer time + + align:start position:0% +longer time + + + align:start position:0% +longer time +but as soon as i close the window i want + + align:start position:0% +but as soon as i close the window i want + + + align:start position:0% +but as soon as i close the window i want +to be able to tell in constant time + + align:start position:0% +to be able to tell in constant time + + + align:start position:0% +to be able to tell in constant time +right + + align:start position:0% + + + + align:start position:0% + +what the k highest bidders are + + align:start position:0% +what the k highest bidders are + + + align:start position:0% +what the k highest bidders are +any ideas on how to do this what are the + + align:start position:0% +any ideas on how to do this what are the + + + align:start position:0% +any ideas on how to do this what are the +operations that i have to do i have to + + align:start position:0% +operations that i have to do i have to + + + align:start position:0% +operations that i have to do i have to +be able to place a new bid right i + + align:start position:0% +be able to place a new bid right i + + + align:start position:0% +be able to place a new bid right i +associated with a bidder is an id + + align:start position:0% +associated with a bidder is an id + + + align:start position:0% +associated with a bidder is an id +and a bid which is also an integer right + + align:start position:0% +and a bid which is also an integer right + + + align:start position:0% +and a bid which is also an integer right +how many dollars i'm going to pay for + + align:start position:0% +how many dollars i'm going to pay for + + + align:start position:0% +how many dollars i'm going to pay for +this book + + align:start position:0% +this book + + + align:start position:0% +this book +uh update the bid in some sense i need + + align:start position:0% +uh update the bid in some sense i need + + + align:start position:0% +uh update the bid in some sense i need +to find + + align:start position:0% +to find + + + align:start position:0% +to find +whether that person placed the bid + + align:start position:0% +whether that person placed the bid + + + align:start position:0% +whether that person placed the bid +before right + + align:start position:0% +before right + + + align:start position:0% +before right +in my data structure so at some point + + align:start position:0% +in my data structure so at some point + + + align:start position:0% +in my data structure so at some point +i'm going to need a find on bidder id + + align:start position:0% +i'm going to need a find on bidder id + + + align:start position:0% +i'm going to need a find on bidder id +does that seem possible right so i might + + align:start position:0% +does that seem possible right so i might + + + align:start position:0% +does that seem possible right so i might +want to have some kind of dictionary + + align:start position:0% +want to have some kind of dictionary + + + align:start position:0% +want to have some kind of dictionary +on bitter ids right when i say that i + + align:start position:0% +on bitter ids right when i say that i + + + align:start position:0% +on bitter ids right when i say that i +want to + + align:start position:0% +want to + + + align:start position:0% +want to +have a dictionary on something right i'm + + align:start position:0% +have a dictionary on something right i'm + + + align:start position:0% +have a dictionary on something right i'm +not specifying to you yet + + align:start position:0% +not specifying to you yet + + + align:start position:0% +not specifying to you yet +how i'm going to implement that + + align:start position:0% +how i'm going to implement that + + + align:start position:0% +how i'm going to implement that +dictionary right what are my usual + + align:start position:0% +dictionary right what are my usual + + + align:start position:0% +dictionary right what are my usual +options + + align:start position:0% +options + + + align:start position:0% +options +a hash table but what if i need worst + + align:start position:0% +a hash table but what if i need worst + + + align:start position:0% +a hash table but what if i need worst +case time + + align:start position:0% + + + + align:start position:0% + +a set avl tree right that's going to be + + align:start position:0% +a set avl tree right that's going to be + + + align:start position:0% +a set avl tree right that's going to be +your go to for a dictionary + + align:start position:0% +your go to for a dictionary + + + align:start position:0% +your go to for a dictionary +right because that's going to give me + + align:start position:0% +right because that's going to give me + + + align:start position:0% +right because that's going to give me +log n time to find things by a key + + align:start position:0% +log n time to find things by a key + + + align:start position:0% +log n time to find things by a key +right it's the only thing except for + + align:start position:0% +right it's the only thing except for + + + align:start position:0% +right it's the only thing except for +assorted or + + align:start position:0% +assorted or + + + align:start position:0% +assorted or +sorted you could also use a sorted array + + align:start position:0% +sorted you could also use a sorted array + + + align:start position:0% +sorted you could also use a sorted array +right but that's going to + + align:start position:0% +right but that's going to + + + align:start position:0% +right but that's going to +not be dynamic and here we're updating + + align:start position:0% +not be dynamic and here we're updating + + + align:start position:0% +not be dynamic and here we're updating +who's in my data structure all the time + + align:start position:0% +who's in my data structure all the time + + + align:start position:0% +who's in my data structure all the time +right + + align:start position:0% +right + + + align:start position:0% +right +people are going in and placing bids + + align:start position:0% +people are going in and placing bids + + + align:start position:0% +people are going in and placing bids +right new + + align:start position:0% +right new + + + align:start position:0% +right new +new people placing bids so my set of + + align:start position:0% +new people placing bids so my set of + + + align:start position:0% +new people placing bids so my set of +things that i care about is changing all + + align:start position:0% +things that i care about is changing all + + + align:start position:0% +things that i care about is changing all +the time + + align:start position:0% +the time + + + align:start position:0% +the time +so that's probably going to steer me + + align:start position:0% +so that's probably going to steer me + + + align:start position:0% +so that's probably going to steer me +away from sorted arrays because + + align:start position:0% +away from sorted arrays because + + + align:start position:0% +away from sorted arrays because +they're not good with dynamic operations + + align:start position:0% +they're not good with dynamic operations + + + align:start position:0% +they're not good with dynamic operations +okay so i'm going to need some kind of + + align:start position:0% +okay so i'm going to need some kind of + + + align:start position:0% +okay so i'm going to need some kind of +dictionary on + + align:start position:0% +dictionary on + + + align:start position:0% +dictionary on +bitter ids but i'm also going to need to + + align:start position:0% +bitter ids but i'm also going to need to + + + align:start position:0% +bitter ids but i'm also going to need to +maintain the the sum + + align:start position:0% +maintain the the sum + + + align:start position:0% +maintain the the sum +right of the k highest bidders does that + + align:start position:0% +right of the k highest bidders does that + + + align:start position:0% +right of the k highest bidders does that +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +right and so in some sense i need to + + align:start position:0% +right and so in some sense i need to + + + align:start position:0% +right and so in some sense i need to +keep track of + + align:start position:0% +keep track of + + + align:start position:0% +keep track of +an ordered notion of + + align:start position:0% +an ordered notion of + + + align:start position:0% +an ordered notion of +the bidders right the bids that are in + + align:start position:0% +the bidders right the bids that are in + + + align:start position:0% +the bidders right the bids that are in +my data structure does that make sense + + align:start position:0% +my data structure does that make sense + + + align:start position:0% +my data structure does that make sense +right so order is going to be important + + align:start position:0% +right so order is going to be important + + + align:start position:0% +right so order is going to be important +on the bids i'm going to need to look up + + align:start position:0% +on the bids i'm going to need to look up + + + align:start position:0% +on the bids i'm going to need to look up +on bitter id + + align:start position:0% + + + + align:start position:0% + +and that's about it right + + align:start position:0% +and that's about it right + + + align:start position:0% +and that's about it right +okay yeah just checking so something + + align:start position:0% + + + + align:start position:0% + +yes correct yeah so uh + + align:start position:0% +yes correct yeah so uh + + + align:start position:0% +yes correct yeah so uh +that's a very good observation right if + + align:start position:0% +that's a very good observation right if + + + align:start position:0% +that's a very good observation right if +it runs in worst case + + align:start position:0% +it runs in worst case + + + align:start position:0% +it runs in worst case +time it also runs unexpected that time + + align:start position:0% +time it also runs unexpected that time + + + align:start position:0% +time it also runs unexpected that time +right because there's essentially no + + align:start position:0% +right because there's essentially no + + + align:start position:0% +right because there's essentially no +randomization that i'm talking about + + align:start position:0% +randomization that i'm talking about + + + align:start position:0% +randomization that i'm talking about +here right + + align:start position:0% + + + + align:start position:0% + +yeah it's so there's a stronger notion + + align:start position:0% +yeah it's so there's a stronger notion + + + align:start position:0% +yeah it's so there's a stronger notion +which we want you to specify + + align:start position:0% +which we want you to specify + + + align:start position:0% +which we want you to specify +which that actually there is no + + align:start position:0% +which that actually there is no + + + align:start position:0% +which that actually there is no +randomization here we're not using a + + align:start position:0% +randomization here we're not using a + + + align:start position:0% +randomization here we're not using a +hash table + + align:start position:0% +hash table + + + align:start position:0% +hash table +right in this class that really that's + + align:start position:0% +right in this class that really that's + + + align:start position:0% +right in this class that really that's +the only situation where + + align:start position:0% +the only situation where + + + align:start position:0% +the only situation where +uh that's going to be an issue right uh + + align:start position:0% +uh that's going to be an issue right uh + + + align:start position:0% +uh that's going to be an issue right uh +so + + align:start position:0% +so + + + align:start position:0% +so +uh but if it is uh what this problem is + + align:start position:0% +uh but if it is uh what this problem is + + + align:start position:0% +uh but if it is uh what this problem is +saying + + align:start position:0% +saying + + + align:start position:0% +saying +uh for each other state whether your + + align:start position:0% +uh for each other state whether your + + + align:start position:0% +uh for each other state whether your +running time is worst case expected + + align:start position:0% +running time is worst case expected + + + align:start position:0% +running time is worst case expected +and or amortized what we're really + + align:start position:0% +and or amortized what we're really + + + align:start position:0% +and or amortized what we're really +trying to get you to say is + + align:start position:0% +trying to get you to say is + + + align:start position:0% +trying to get you to say is +what's the uh + + align:start position:0% +what's the uh + + + align:start position:0% +what's the uh +evaluate the running time of your + + align:start position:0% +evaluate the running time of your + + + align:start position:0% +evaluate the running time of your +algorithm with the proper qualifications + + align:start position:0% +algorithm with the proper qualifications + + + align:start position:0% +algorithm with the proper qualifications +right + + align:start position:0% +right + + + align:start position:0% +right +if it took worst case i want you to say + + align:start position:0% +if it took worst case i want you to say + + + align:start position:0% +if it took worst case i want you to say +that it took worst case + + align:start position:0% +that it took worst case + + + align:start position:0% +that it took worst case +if it took if you use the hash table i + + align:start position:0% +if it took if you use the hash table i + + + align:start position:0% +if it took if you use the hash table i +want you to say expected + + align:start position:0% +want you to say expected + + + align:start position:0% +want you to say expected +and if these operations i were sometimes + + align:start position:0% +and if these operations i were sometimes + + + align:start position:0% +and if these operations i were sometimes +really bad + + align:start position:0% +really bad + + + align:start position:0% +really bad +but on average they're really good if i + + align:start position:0% +but on average they're really good if i + + + align:start position:0% +but on average they're really good if i +did a lot of them that's that's + + align:start position:0% +did a lot of them that's that's + + + align:start position:0% +did a lot of them that's that's +amortized right + + align:start position:0% +amortized right + + + align:start position:0% +amortized right +right or if i reduce to using a dynamic + + align:start position:0% +right or if i reduce to using a dynamic + + + align:start position:0% +right or if i reduce to using a dynamic +array + + align:start position:0% +array + + + align:start position:0% +array +right or if i reduce to using a hash + + align:start position:0% +right or if i reduce to using a hash + + + align:start position:0% +right or if i reduce to using a hash +table those dynamic operations would + + align:start position:0% +table those dynamic operations would + + + align:start position:0% +table those dynamic operations would +still be amortized right + + align:start position:0% +still be amortized right + + + align:start position:0% +still be amortized right +okay so the dynamic ones uh nice thing + + align:start position:0% +okay so the dynamic ones uh nice thing + + + align:start position:0% +okay so the dynamic ones uh nice thing +about + + align:start position:0% +about + + + align:start position:0% +about +linked data structures is that dynamic + + align:start position:0% +linked data structures is that dynamic + + + align:start position:0% +linked data structures is that dynamic +operations aren't amortized right + + align:start position:0% +operations aren't amortized right + + + align:start position:0% +operations aren't amortized right +so we're gonna get be able to get now + + align:start position:0% +so we're gonna get be able to get now + + + align:start position:0% +so we're gonna get be able to get now +for this problem we can actually get + + align:start position:0% +for this problem we can actually get + + + align:start position:0% +for this problem we can actually get +worst case bounds so we're going to try + + align:start position:0% +worst case bounds so we're going to try + + + align:start position:0% +worst case bounds so we're going to try +for that + + align:start position:0% +for that + + + align:start position:0% +for that +you can also do it in expected using + + align:start position:0% +you can also do it in expected using + + + align:start position:0% +you can also do it in expected using +some hash tables for that + + align:start position:0% +some hash tables for that + + + align:start position:0% +some hash tables for that +that dictionary right okay so + + align:start position:0% +that dictionary right okay so + + + align:start position:0% +that dictionary right okay so +when you approach a data structures + + align:start position:0% +when you approach a data structures + + + align:start position:0% +when you approach a data structures +problem in this class + + align:start position:0% +problem in this class + + + align:start position:0% +problem in this class +you want to tell me what it is you're + + align:start position:0% +you want to tell me what it is you're + + + align:start position:0% +you want to tell me what it is you're +storing + + align:start position:0% +storing + + + align:start position:0% +storing +first off right tell me + + align:start position:0% +first off right tell me + + + align:start position:0% +first off right tell me +what's supposed to be in those things + + align:start position:0% +what's supposed to be in those things + + + align:start position:0% +what's supposed to be in those things +right some invariants on this data + + align:start position:0% +right some invariants on this data + + + align:start position:0% +right some invariants on this data +structure + + align:start position:0% +structure + + + align:start position:0% +structure +to you know make sure that when i do + + align:start position:0% +to you know make sure that when i do + + + align:start position:0% +to you know make sure that when i do +queries later + + align:start position:0% +queries later + + + align:start position:0% +queries later +right that these things are being + + align:start position:0% +right that these things are being + + + align:start position:0% +right that these things are being +maintained right so that + + align:start position:0% +maintained right so that + + + align:start position:0% +maintained right so that +uh you know if i have you know if i'm + + align:start position:0% +uh you know if i have you know if i'm + + + align:start position:0% +uh you know if i have you know if i'm +maintaining a sorted array + + align:start position:0% +maintaining a sorted array + + + align:start position:0% +maintaining a sorted array +right and i'm supporting an operation to + + align:start position:0% +right and i'm supporting an operation to + + + align:start position:0% +right and i'm supporting an operation to +find the maximum + + align:start position:0% +find the maximum + + + align:start position:0% +find the maximum +i better anything i do to this data + + align:start position:0% +i better anything i do to this data + + + align:start position:0% +i better anything i do to this data +structure better be maintaining the + + align:start position:0% +structure better be maintaining the + + + align:start position:0% +structure better be maintaining the +invariance that these things are in + + align:start position:0% +invariance that these things are in + + + align:start position:0% +invariance that these things are in +sorted order and the last thing + + align:start position:0% +sorted order and the last thing + + + align:start position:0% +sorted order and the last thing +has the maximum item because my max + + align:start position:0% +has the maximum item because my max + + + align:start position:0% +has the maximum item because my max +return thing is going to look there and + + align:start position:0% +return thing is going to look there and + + + align:start position:0% +return thing is going to look there and +return that + + align:start position:0% +return that + + + align:start position:0% +return that +does that make sense so i want to tell + + align:start position:0% +does that make sense so i want to tell + + + align:start position:0% +does that make sense so i want to tell +you you want to tell me what is being + + align:start position:0% +you you want to tell me what is being + + + align:start position:0% +you you want to tell me what is being +stored + + align:start position:0% +stored + + + align:start position:0% +stored +at you know a generic point in time + + align:start position:0% +at you know a generic point in time + + + align:start position:0% +at you know a generic point in time +during your data structure + + align:start position:0% +during your data structure + + + align:start position:0% +during your data structure +right what is being maintained so that + + align:start position:0% +right what is being maintained so that + + + align:start position:0% +right what is being maintained so that +when i support a dynamic operation or a + + align:start position:0% +when i support a dynamic operation or a + + + align:start position:0% +when i support a dynamic operation or a +query + + align:start position:0% +query + + + align:start position:0% +query +right in a dynamic operation where i'm + + align:start position:0% +right in a dynamic operation where i'm + + + align:start position:0% +right in a dynamic operation where i'm +inserting and deleting things from this + + align:start position:0% +inserting and deleting things from this + + + align:start position:0% +inserting and deleting things from this +thing + + align:start position:0% +thing + + + align:start position:0% +thing +i need to make sure that i'm maintaining + + align:start position:0% +i need to make sure that i'm maintaining + + + align:start position:0% +i need to make sure that i'm maintaining +those invariants + + align:start position:0% +those invariants + + + align:start position:0% +those invariants +and when i'm querying i can actually + + align:start position:0% +and when i'm querying i can actually + + + align:start position:0% +and when i'm querying i can actually +rely on those invariants + + align:start position:0% +rely on those invariants + + + align:start position:0% +rely on those invariants +to to answer my query does that make + + align:start position:0% +to to answer my query does that make + + + align:start position:0% +to to answer my query does that make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so for this problem this is + + align:start position:0% + + + + align:start position:0% + +okay uh any ideas + + align:start position:0% +okay uh any ideas + + + align:start position:0% +okay uh any ideas +i have two two kind of keys that i might + + align:start position:0% +i have two two kind of keys that i might + + + align:start position:0% +i have two two kind of keys that i might +have to deal with one's a bid id and + + align:start position:0% +have to deal with one's a bid id and + + + align:start position:0% +have to deal with one's a bid id and +one's a + + align:start position:0% +one's a + + + align:start position:0% +one's a +a bid right so how could i + + align:start position:0% +a bid right so how could i + + + align:start position:0% +a bid right so how could i +if i have two keys right that i might + + align:start position:0% +if i have two keys right that i might + + + align:start position:0% +if i have two keys right that i might +want to + + align:start position:0% +want to + + + align:start position:0% +want to +maybe order on one and look up on + + align:start position:0% +maybe order on one and look up on + + + align:start position:0% +maybe order on one and look up on +another + + align:start position:0% +another + + + align:start position:0% +another +how many data structures do you think + + align:start position:0% +how many data structures do you think + + + align:start position:0% +how many data structures do you think +i'm going to use + + align:start position:0% +i'm going to use + + + align:start position:0% +i'm going to use +two that's a pretty good guess okay + + align:start position:0% +two that's a pretty good guess okay + + + align:start position:0% +two that's a pretty good guess okay +so one of them let's just guess right + + align:start position:0% +so one of them let's just guess right + + + align:start position:0% +so one of them let's just guess right +like i need to be able to look up on + + align:start position:0% +like i need to be able to look up on + + + align:start position:0% +like i need to be able to look up on +bid right so let's + + align:start position:0% +bid right so let's + + + align:start position:0% +bid right so let's +store these bitters + + align:start position:0% +store these bitters + + + align:start position:0% +store these bitters +right in some kind of dictionary that's + + align:start position:0% +right in some kind of dictionary that's + + + align:start position:0% +right in some kind of dictionary that's +going to be able to look up those things + + align:start position:0% +going to be able to look up those things + + + align:start position:0% +going to be able to look up those things +fast right so + + align:start position:0% +fast right so + + + align:start position:0% +fast right so +you know two data structures right one + + align:start position:0% +you know two data structures right one + + + align:start position:0% +you know two data structures right one +is a + + align:start position:0% +is a + + + align:start position:0% +is a +a dictionary on + + align:start position:0% +a dictionary on + + + align:start position:0% +a dictionary on +a keyed + + align:start position:0% +a keyed + + + align:start position:0% +a keyed +on bitter + + align:start position:0% +on bitter + + + align:start position:0% +on bitter +id okay + + align:start position:0% + + + + align:start position:0% + +what else am i going to want + + align:start position:0% +what else am i going to want + + + align:start position:0% +what else am i going to want +what's up + + align:start position:0% + + + + align:start position:0% + +the other way around a dictionary stored + + align:start position:0% +the other way around a dictionary stored + + + align:start position:0% +the other way around a dictionary stored +on the bids + + align:start position:0% +on the bids + + + align:start position:0% +on the bids +is a dictionary what i want here + + align:start position:0% +is a dictionary what i want here + + + align:start position:0% +is a dictionary what i want here +i want to maintain order somehow right + + align:start position:0% +i want to maintain order somehow right + + + align:start position:0% +i want to maintain order somehow right +because i want to maintain the k + + align:start position:0% +because i want to maintain the k + + + align:start position:0% +because i want to maintain the k +biggest things that i've seen so far + + align:start position:0% +biggest things that i've seen so far + + + align:start position:0% +biggest things that i've seen so far +right now + + align:start position:0% +right now + + + align:start position:0% +right now +if if i had at some point in time right + + align:start position:0% +if if i had at some point in time right + + + align:start position:0% +if if i had at some point in time right +what's going to happen right if i'm + + align:start position:0% +what's going to happen right if i'm + + + align:start position:0% +what's going to happen right if i'm +maintaining the k largest at any point + + align:start position:0% +maintaining the k largest at any point + + + align:start position:0% +maintaining the k largest at any point +in time + + align:start position:0% +in time + + + align:start position:0% +in time +it's possible that one of those bidders + + align:start position:0% +it's possible that one of those bidders + + + align:start position:0% +it's possible that one of those bidders +maybe decreases his bid + + align:start position:0% +maybe decreases his bid + + + align:start position:0% +maybe decreases his bid +right so it's no longer in the highest + + align:start position:0% +right so it's no longer in the highest + + + align:start position:0% +right so it's no longer in the highest +i'm going to also need to keep track of + + align:start position:0% +i'm going to also need to keep track of + + + align:start position:0% +i'm going to also need to keep track of +the other guys to see who i should add + + align:start position:0% +the other guys to see who i should add + + + align:start position:0% +the other guys to see who i should add +back into that set + + align:start position:0% +back into that set + + + align:start position:0% +back into that set +for example right so here's an idea + + align:start position:0% +for example right so here's an idea + + + align:start position:0% +for example right so here's an idea +i'm going to keep not just one other + + align:start position:0% +i'm going to keep not just one other + + + align:start position:0% +i'm going to keep not just one other +data structure but + + align:start position:0% +data structure but + + + align:start position:0% +data structure but +two other data structures maybe this is + + align:start position:0% +two other data structures maybe this is + + + align:start position:0% +two other data structures maybe this is +a leap + + align:start position:0% +a leap + + + align:start position:0% +a leap +you don't have to do this there's a way + + align:start position:0% +you don't have to do this there's a way + + + align:start position:0% +you don't have to do this there's a way +to do it with just one another + + align:start position:0% +to do it with just one another + + + align:start position:0% +to do it with just one another +but i'm going to store two more one is a + + align:start position:0% +but i'm going to store two more one is a + + + align:start position:0% +but i'm going to store two more one is a +kind of a data structure + + align:start position:0% +kind of a data structure + + + align:start position:0% +kind of a data structure +to store + + align:start position:0% + + + + align:start position:0% + +with uh store + + align:start position:0% + + + + align:start position:0% + +the k highest + + align:start position:0% +the k highest + + + align:start position:0% +the k highest +bidders + + align:start position:0% + + + + align:start position:0% + +and a data structure to store the + + align:start position:0% + + + + align:start position:0% + +n minus k highest bidders + + align:start position:0% +n minus k highest bidders + + + align:start position:0% +n minus k highest bidders +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +so this separates my problem quite + + align:start position:0% +so this separates my problem quite + + + align:start position:0% +so this separates my problem quite +nicely right + + align:start position:0% +nicely right + + + align:start position:0% +nicely right +if every time someone does an + + align:start position:0% +if every time someone does an + + + align:start position:0% +if every time someone does an +interaction with this data structure + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +i can check to see whether it's bigger + + align:start position:0% +i can check to see whether it's bigger + + + align:start position:0% +i can check to see whether it's bigger +than the smallest thing in here + + align:start position:0% +than the smallest thing in here + + + align:start position:0% +than the smallest thing in here +right if it is i can do the same kind of + + align:start position:0% +right if it is i can do the same kind of + + + align:start position:0% +right if it is i can do the same kind of +trick i did before right + + align:start position:0% +trick i did before right + + + align:start position:0% +trick i did before right +i can remove it and stick my new one in + + align:start position:0% +i can remove it and stick my new one in + + + align:start position:0% +i can remove it and stick my new one in +there + + align:start position:0% +there + + + align:start position:0% +there +right and where do i but i removed it i + + align:start position:0% +right and where do i but i removed it i + + + align:start position:0% +right and where do i but i removed it i +have to maintain this + + align:start position:0% +have to maintain this + + + align:start position:0% +have to maintain this +property right so i stick it in here + + align:start position:0% +property right so i stick it in here + + + align:start position:0% +property right so i stick it in here +right + + align:start position:0% +right + + + align:start position:0% +right +there's another case what's the other + + align:start position:0% +there's another case what's the other + + + align:start position:0% +there's another case what's the other +case + + align:start position:0% + + + + align:start position:0% + +it's smaller right in which case + + align:start position:0% +it's smaller right in which case + + + align:start position:0% +it's smaller right in which case +i don't do anything to this data + + align:start position:0% +i don't do anything to this data + + + align:start position:0% +i don't do anything to this data +structure and i just stick it into here + + align:start position:0% +structure and i just stick it into here + + + align:start position:0% +structure and i just stick it into here +that makes sense right so what are the + + align:start position:0% +that makes sense right so what are the + + + align:start position:0% +that makes sense right so what are the +operations these data structures need to + + align:start position:0% +operations these data structures need to + + + align:start position:0% +operations these data structures need to +maintain finding the minimum or the + + align:start position:0% +maintain finding the minimum or the + + + align:start position:0% +maintain finding the minimum or the +maximum + + align:start position:0% +maximum + + + align:start position:0% +maximum +of these two sets does that make sense + + align:start position:0% +of these two sets does that make sense + + + align:start position:0% +of these two sets does that make sense +and actually not + + align:start position:0% +and actually not + + + align:start position:0% +and actually not +really the where are those operations i + + align:start position:0% +really the where are those operations i + + + align:start position:0% +really the where are those operations i +don't have them anymore + + align:start position:0% +don't have them anymore + + + align:start position:0% +don't have them anymore +but they were the priority queue + + align:start position:0% +but they were the priority queue + + + align:start position:0% +but they were the priority queue +operations they had + + align:start position:0% +operations they had + + + align:start position:0% +operations they had +uh delete max right and also insert + + align:start position:0% +uh delete max right and also insert + + + align:start position:0% +uh delete max right and also insert +where things that it did well on right + + align:start position:0% +where things that it did well on right + + + align:start position:0% +where things that it did well on right +so any priority queue right anything + + align:start position:0% +so any priority queue right anything + + + align:start position:0% +so any priority queue right anything +that + + align:start position:0% +that + + + align:start position:0% +that +can deal with maxes and mins right + + align:start position:0% +can deal with maxes and mins right + + + align:start position:0% +can deal with maxes and mins right +is good right and and what what's a data + + align:start position:0% +is good right and and what what's a data + + + align:start position:0% +is good right and and what what's a data +structure you know that can deal with + + align:start position:0% +structure you know that can deal with + + + align:start position:0% +structure you know that can deal with +maxes and mins pretty efficiently + + align:start position:0% +maxes and mins pretty efficiently + + + align:start position:0% +maxes and mins pretty efficiently +the set avl right so + + align:start position:0% +the set avl right so + + + align:start position:0% +the set avl right so +instead of data structure here i'm going + + align:start position:0% +instead of data structure here i'm going + + + align:start position:0% +instead of data structure here i'm going +to say + + align:start position:0% +to say + + + align:start position:0% +to say +set avm + + align:start position:0% +set avm + + + align:start position:0% +set avm +and obviously it's going to + + align:start position:0% +and obviously it's going to + + + align:start position:0% +and obviously it's going to +be keyed by + + align:start position:0% + + + + align:start position:0% + +bid right because that's the thing that + + align:start position:0% +bid right because that's the thing that + + + align:start position:0% +bid right because that's the thing that +i'm going to want to find max's and mins + + align:start position:0% +i'm going to want to find max's and mins + + + align:start position:0% +i'm going to want to find max's and mins +over + + align:start position:0% +over + + + align:start position:0% +over +okay everyone following the logic here + + align:start position:0% +okay everyone following the logic here + + + align:start position:0% +okay everyone following the logic here +of why i mean + + align:start position:0% +of why i mean + + + align:start position:0% +of why i mean +i'm maintaining these things so this is + + align:start position:0% +i'm maintaining these things so this is + + + align:start position:0% +i'm maintaining these things so this is +this is the level of an invariance that + + align:start position:0% +this is the level of an invariance that + + + align:start position:0% +this is the level of an invariance that +i want to maintain because + + align:start position:0% +i want to maintain because + + + align:start position:0% +i want to maintain because +when i go to for example do this query + + align:start position:0% +when i go to for example do this query + + + align:start position:0% +when i go to for example do this query +get revenue right i can just run through + + align:start position:0% +get revenue right i can just run through + + + align:start position:0% +get revenue right i can just run through +and + + align:start position:0% +and + + + align:start position:0% +and +sum all of these things oh wait how much + + align:start position:0% +sum all of these things oh wait how much + + + align:start position:0% +sum all of these things oh wait how much +time do i have + + align:start position:0% +time do i have + + + align:start position:0% +time do i have +do i have k time no i don't have k time + + align:start position:0% +do i have k time no i don't have k time + + + align:start position:0% +do i have k time no i don't have k time +so i don't + + align:start position:0% +so i don't + + + align:start position:0% +so i don't +i can't afford to sum up all of these + + align:start position:0% +i can't afford to sum up all of these + + + align:start position:0% +i can't afford to sum up all of these +things at the end of my + + align:start position:0% +things at the end of my + + + align:start position:0% +things at the end of my +right i have to i have to return it to + + align:start position:0% +right i have to i have to return it to + + + align:start position:0% +right i have to i have to return it to +you in constant time + + align:start position:0% +you in constant time + + + align:start position:0% +you in constant time +any ideas yeah just + + align:start position:0% +any ideas yeah just + + + align:start position:0% +any ideas yeah just +compute you know update a song right + + align:start position:0% +compute you know update a song right + + + align:start position:0% +compute you know update a song right +along with this + + align:start position:0% +along with this + + + align:start position:0% +along with this +data structure i'm going to keep a + + align:start position:0% +data structure i'm going to keep a + + + align:start position:0% +data structure i'm going to keep a +fourth thing + + align:start position:0% +fourth thing + + + align:start position:0% +fourth thing +which is just total + + align:start position:0% + + + + align:start position:0% + +of their bits right i'm going to call it + + align:start position:0% +of their bits right i'm going to call it + + + align:start position:0% +of their bits right i'm going to call it +like a + + align:start position:0% +like a + + + align:start position:0% +like a +t okay + + align:start position:0% +t okay + + + align:start position:0% +t okay +and that's something i'm maintaining + + align:start position:0% +and that's something i'm maintaining + + + align:start position:0% +and that's something i'm maintaining +it's part of my data structure + + align:start position:0% +it's part of my data structure + + + align:start position:0% +it's part of my data structure +right it's you could think of it as i'm + + align:start position:0% +right it's you could think of it as i'm + + + align:start position:0% +right it's you could think of it as i'm +augmenting this thing with a number + + align:start position:0% +augmenting this thing with a number + + + align:start position:0% +augmenting this thing with a number +right and the point of augmenting this + + align:start position:0% +right and the point of augmenting this + + + align:start position:0% +right and the point of augmenting this +thing with the number + + align:start position:0% +thing with the number + + + align:start position:0% +thing with the number +right is that i can just if i need to + + align:start position:0% +right is that i can just if i need to + + + align:start position:0% +right is that i can just if i need to +know what the total of this stuff is i + + align:start position:0% +know what the total of this stuff is i + + + align:start position:0% +know what the total of this stuff is i +can just look at that number + + align:start position:0% +can just look at that number + + + align:start position:0% +can just look at that number +does that make sense all right + + align:start position:0% +does that make sense all right + + + align:start position:0% +does that make sense all right +so now i think you know we're almost + + align:start position:0% +so now i think you know we're almost + + + align:start position:0% +so now i think you know we're almost +done we're basically done + + align:start position:0% +done we're basically done + + + align:start position:0% +done we're basically done +right how do we do this uh + + align:start position:0% +right how do we do this uh + + + align:start position:0% +right how do we do this uh +someone walk through to me how i would + + align:start position:0% +someone walk through to me how i would + + + align:start position:0% +someone walk through to me how i would +get revenue with this data structure + + align:start position:0% +get revenue with this data structure + + + align:start position:0% +get revenue with this data structure +i just i basically kind of told you look + + align:start position:0% +i just i basically kind of told you look + + + align:start position:0% +i just i basically kind of told you look +at this number + + align:start position:0% +at this number + + + align:start position:0% +at this number +return it right because that's the + + align:start position:0% +return it right because that's the + + + align:start position:0% +return it right because that's the +invariance that i've maintained + + align:start position:0% +invariance that i've maintained + + + align:start position:0% +invariance that i've maintained +on my data structure i'm relying on this + + align:start position:0% +on my data structure i'm relying on this + + + align:start position:0% +on my data structure i'm relying on this +invariant now + + align:start position:0% +invariant now + + + align:start position:0% +invariant now +i better make sure this is good when i + + align:start position:0% +i better make sure this is good when i + + + align:start position:0% +i better make sure this is good when i +do dynamic operations + + align:start position:0% +do dynamic operations + + + align:start position:0% +do dynamic operations +right i make sure i maintain it but if i + + align:start position:0% +right i make sure i maintain it but if i + + + align:start position:0% +right i make sure i maintain it but if i +by induction + + align:start position:0% +by induction + + + align:start position:0% +by induction +are ensured that all of this stuff is + + align:start position:0% +are ensured that all of this stuff is + + + align:start position:0% +are ensured that all of this stuff is +good and when i do a dynamic operation + + align:start position:0% +good and when i do a dynamic operation + + + align:start position:0% +good and when i do a dynamic operation +all that stuff is maintained + + align:start position:0% +all that stuff is maintained + + + align:start position:0% +all that stuff is maintained +then i'm all good right so get revenue + + align:start position:0% +then i'm all good right so get revenue + + + align:start position:0% +then i'm all good right so get revenue +after i kind of did all this extra work + + align:start position:0% +after i kind of did all this extra work + + + align:start position:0% +after i kind of did all this extra work +right it's very easy i just look at this + + align:start position:0% +right it's very easy i just look at this + + + align:start position:0% +right it's very easy i just look at this +number and return it + + align:start position:0% +number and return it + + + align:start position:0% +number and return it +okay so when we're grading a data + + align:start position:0% +okay so when we're grading a data + + + align:start position:0% +okay so when we're grading a data +structures problem usually we give you + + align:start position:0% +structures problem usually we give you + + + align:start position:0% +structures problem usually we give you +some points first for + + align:start position:0% +some points first for + + + align:start position:0% +some points first for +setting up your data structure + + align:start position:0% +setting up your data structure + + + align:start position:0% +setting up your data structure +separately from the operations and then + + align:start position:0% +separately from the operations and then + + + align:start position:0% +separately from the operations and then +we give you + + align:start position:0% +we give you + + + align:start position:0% +we give you +points per operation that you + + align:start position:0% +points per operation that you + + + align:start position:0% +points per operation that you +successfully deal with + + align:start position:0% +successfully deal with + + + align:start position:0% +successfully deal with +and then some points for correctness and + + align:start position:0% +and then some points for correctness and + + + align:start position:0% +and then some points for correctness and +running time + + align:start position:0% +running time + + + align:start position:0% +running time +yeah you have a question so + + align:start position:0% +yeah you have a question so + + + align:start position:0% +yeah you have a question so +would total be like a thing that we + + align:start position:0% +would total be like a thing that we + + + align:start position:0% +would total be like a thing that we +update whenever we + + align:start position:0% +update whenever we + + + align:start position:0% +update whenever we +um like mess around with the highest + + align:start position:0% +um like mess around with the highest + + + align:start position:0% +um like mess around with the highest +bitter tree and then + + align:start position:0% +bitter tree and then + + + align:start position:0% +bitter tree and then +and minus k highest bigger tree sorry + + align:start position:0% +and minus k highest bigger tree sorry + + + align:start position:0% +and minus k highest bigger tree sorry +say that again + + align:start position:0% +say that again + + + align:start position:0% +say that again +so like are we treating like the total + + align:start position:0% +so like are we treating like the total + + + align:start position:0% +so like are we treating like the total +like of like an augmentation that we + + align:start position:0% +like of like an augmentation that we + + + align:start position:0% +like of like an augmentation that we +update every time we do something yeah + + align:start position:0% +update every time we do something yeah + + + align:start position:0% +update every time we do something yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so it's just a one number it's not + + align:start position:0% +so it's just a one number it's not + + + align:start position:0% +so it's just a one number it's not +really a data structure it's just one + + align:start position:0% +really a data structure it's just one + + + align:start position:0% +really a data structure it's just one +number + + align:start position:0% +number + + + align:start position:0% +number +that i'm storing with my my database + + align:start position:0% +that i'm storing with my my database + + + align:start position:0% +that i'm storing with my my database +right + + align:start position:0% +right + + + align:start position:0% +right +okay all right so how do i implement + + align:start position:0% +okay all right so how do i implement + + + align:start position:0% +okay all right so how do i implement +a uh new bid operation + + align:start position:0% + + + + align:start position:0% + +yeah can we assume that the bids will + + align:start position:0% +yeah can we assume that the bids will + + + align:start position:0% +yeah can we assume that the bids will +also be unique + + align:start position:0% +also be unique + + + align:start position:0% +also be unique +can you assume that the bids may be + + align:start position:0% +can you assume that the bids may be + + + align:start position:0% +can you assume that the bids may be +unique no + + align:start position:0% +unique no + + + align:start position:0% +unique no +right so that's actually something that + + align:start position:0% +right so that's actually something that + + + align:start position:0% +right so that's actually something that +is a really useful observation + + align:start position:0% +is a really useful observation + + + align:start position:0% +is a really useful observation +we've been talking about set data + + align:start position:0% +we've been talking about set data + + + align:start position:0% +we've been talking about set data +structures + + align:start position:0% +structures + + + align:start position:0% +structures +as requiring unique keys right + + align:start position:0% +as requiring unique keys right + + + align:start position:0% +as requiring unique keys right +how can i deal with non-unique keys it + + align:start position:0% +how can i deal with non-unique keys it + + + align:start position:0% +how can i deal with non-unique keys it +actually turns out that you know hash + + align:start position:0% +actually turns out that you know hash + + + align:start position:0% +actually turns out that you know hash +table it's really important that these + + align:start position:0% +table it's really important that these + + + align:start position:0% +table it's really important that these +be + + align:start position:0% +be + + + align:start position:0% +be +unique keys right because i i need to + + align:start position:0% +unique keys right because i i need to + + + align:start position:0% +unique keys right because i i need to +check whether it's in there i'm looking + + align:start position:0% +check whether it's in there i'm looking + + + align:start position:0% +check whether it's in there i'm looking +for that + + align:start position:0% +for that + + + align:start position:0% +for that +single key and when i find it i have to + + align:start position:0% +single key and when i find it i have to + + + align:start position:0% +single key and when i find it i have to +return right if i had multiple things + + align:start position:0% +return right if i had multiple things + + + align:start position:0% +return right if i had multiple things +with that key + + align:start position:0% +with that key + + + align:start position:0% +with that key +i might not return the one that i'm + + align:start position:0% +i might not return the one that i'm + + + align:start position:0% +i might not return the one that i'm +looking for right it doesn't even make + + align:start position:0% +looking for right it doesn't even make + + + align:start position:0% +looking for right it doesn't even make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +right but you can generalize the + + align:start position:0% +right but you can generalize the + + + align:start position:0% +right but you can generalize the +set uh + + align:start position:0% +set uh + + + align:start position:0% +set uh +uh kind of infrastructure right + + align:start position:0% +uh kind of infrastructure right + + + align:start position:0% +uh kind of infrastructure right +to deal with multi-sets how can i how + + align:start position:0% +to deal with multi-sets how can i how + + + align:start position:0% +to deal with multi-sets how can i how +can i do that + + align:start position:0% +can i do that + + + align:start position:0% +can i do that +well with each key right + + align:start position:0% +well with each key right + + + align:start position:0% +well with each key right +again i'm storing unique keys with each + + align:start position:0% +again i'm storing unique keys with each + + + align:start position:0% +again i'm storing unique keys with each +key i can link it to a sequence data + + align:start position:0% +key i can link it to a sequence data + + + align:start position:0% +key i can link it to a sequence data +structure + + align:start position:0% +structure + + + align:start position:0% +structure +or any other data structure right and + + align:start position:0% +or any other data structure right and + + + align:start position:0% +or any other data structure right and +what i'm do is i'm going to + + align:start position:0% +what i'm do is i'm going to + + + align:start position:0% +what i'm do is i'm going to +anything that has that key i'm going to + + align:start position:0% +anything that has that key i'm going to + + + align:start position:0% +anything that has that key i'm going to +stick it in that data structure + + align:start position:0% +stick it in that data structure + + + align:start position:0% +stick it in that data structure +right so instead of storing one item + + align:start position:0% +right so instead of storing one item + + + align:start position:0% +right so instead of storing one item +there i have the possibility of storing + + align:start position:0% +there i have the possibility of storing + + + align:start position:0% +there i have the possibility of storing +many things there + + align:start position:0% +many things there + + + align:start position:0% +many things there +now i have to change the semantics here + + align:start position:0% +now i have to change the semantics here + + + align:start position:0% +now i have to change the semantics here +right if i'm saying find on this key + + align:start position:0% +right if i'm saying find on this key + + + align:start position:0% +right if i'm saying find on this key +well now i could say i'm going to return + + align:start position:0% +well now i could say i'm going to return + + + align:start position:0% +well now i could say i'm going to return +all of the things with that key + + align:start position:0% +all of the things with that key + + + align:start position:0% +all of the things with that key +or i'm going to show our some thing with + + align:start position:0% +or i'm going to show our some thing with + + + align:start position:0% +or i'm going to show our some thing with +that key + + align:start position:0% +that key + + + align:start position:0% +that key +right but you get the idea all i have to + + align:start position:0% +right but you get the idea all i have to + + + align:start position:0% +right but you get the idea all i have to +do is map it to + + align:start position:0% +do is map it to + + + align:start position:0% +do is map it to +some other data structure to maintain + + align:start position:0% +some other data structure to maintain + + + align:start position:0% +some other data structure to maintain +those things like maybe + + align:start position:0% +those things like maybe + + + align:start position:0% +those things like maybe +i want all the things with that key + + align:start position:0% + + + + align:start position:0% + +i want to find the one with this other + + align:start position:0% +i want to find the one with this other + + + align:start position:0% +i want to find the one with this other +key right + + align:start position:0% +key right + + + align:start position:0% +key right +so maybe i link to a set data structure + + align:start position:0% +so maybe i link to a set data structure + + + align:start position:0% +so maybe i link to a set data structure +that can search on other things right + + align:start position:0% +that can search on other things right + + + align:start position:0% +that can search on other things right +but the idea here is we maintain this + + align:start position:0% +but the idea here is we maintain this + + + align:start position:0% +but the idea here is we maintain this +uniqueness key property + + align:start position:0% +uniqueness key property + + + align:start position:0% +uniqueness key property +right i have to relax my semantics so + + align:start position:0% +right i have to relax my semantics so + + + align:start position:0% +right i have to relax my semantics so +that i'm storing + + align:start position:0% +that i'm storing + + + align:start position:0% +that i'm storing +multiple things at that key location + + align:start position:0% +multiple things at that key location + + + align:start position:0% +multiple things at that key location +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +yeah why does it matter whether you've + + align:start position:0% +yeah why does it matter whether you've + + + align:start position:0% +yeah why does it matter whether you've +said the entree + + align:start position:0% +said the entree + + + align:start position:0% +said the entree +or not uh it does uh so + + align:start position:0% +or not uh it does uh so + + + align:start position:0% +or not uh it does uh so +it's going to matter here right because + + align:start position:0% +it's going to matter here right because + + + align:start position:0% +it's going to matter here right because +i have bids + + align:start position:0% +i have bids + + + align:start position:0% +i have bids +right and the bids could be non-unique + + align:start position:0% +right and the bids could be non-unique + + + align:start position:0% +right and the bids could be non-unique +right + + align:start position:0% +right + + + align:start position:0% +right +two people could have the same you know + + align:start position:0% +two people could have the same you know + + + align:start position:0% +two people could have the same you know +uh bid and by our definition of a set + + align:start position:0% +uh bid and by our definition of a set + + + align:start position:0% +uh bid and by our definition of a set +data structure it had to have unique + + align:start position:0% +data structure it had to have unique + + + align:start position:0% +data structure it had to have unique +keys so if i stuck in all these things + + align:start position:0% +keys so if i stuck in all these things + + + align:start position:0% +keys so if i stuck in all these things +keyed by bidder you got a problem right + + align:start position:0% +keyed by bidder you got a problem right + + + align:start position:0% +keyed by bidder you got a problem right +now in actuality we can get away with + + align:start position:0% +now in actuality we can get away with + + + align:start position:0% +now in actuality we can get away with +that by storing basically a + + align:start position:0% +that by storing basically a + + + align:start position:0% +that by storing basically a +linked list of all the things with that + + align:start position:0% +linked list of all the things with that + + + align:start position:0% +linked list of all the things with that +key and we'd be fine + + align:start position:0% +key and we'd be fine + + + align:start position:0% +key and we'd be fine +right and then whenever i want to + + align:start position:0% +right and then whenever i want to + + + align:start position:0% +right and then whenever i want to +return one i could just do but actually + + align:start position:0% +return one i could just do but actually + + + align:start position:0% +return one i could just do but actually +a binary tree + + align:start position:0% +a binary tree + + + align:start position:0% +a binary tree +right actually is flexible enough that + + align:start position:0% +right actually is flexible enough that + + + align:start position:0% +right actually is flexible enough that +in most implementations you can just + + align:start position:0% +in most implementations you can just + + + align:start position:0% +in most implementations you can just +store a bunch of those things but + + align:start position:0% +store a bunch of those things but + + + align:start position:0% +store a bunch of those things but +actually our run times + + align:start position:0% +actually our run times + + + align:start position:0% +actually our run times +do worse then right what does it mean to + + align:start position:0% +do worse then right what does it mean to + + + align:start position:0% +do worse then right what does it mean to +find next in my sequence + + align:start position:0% +find next in my sequence + + + align:start position:0% +find next in my sequence +right what does it mean to find the + + align:start position:0% +right what does it mean to find the + + + align:start position:0% +right what does it mean to find the +to return the next larger thing above + + align:start position:0% +to return the next larger thing above + + + align:start position:0% +to return the next larger thing above +this key + + align:start position:0% +this key + + + align:start position:0% +this key +doesn't really make sense because there + + align:start position:0% +doesn't really make sense because there + + + align:start position:0% +doesn't really make sense because there +could be multiple ones which one do i + + align:start position:0% +could be multiple ones which one do i + + + align:start position:0% +could be multiple ones which one do i +return + + align:start position:0% +return + + + align:start position:0% +return +and if i repeatedly do find next on this + + align:start position:0% +and if i repeatedly do find next on this + + + align:start position:0% +and if i repeatedly do find next on this +data structure + + align:start position:0% +data structure + + + align:start position:0% +data structure +right i might not loop through all the + + align:start position:0% +right i might not loop through all the + + + align:start position:0% +right i might not loop through all the +things + + align:start position:0% +things + + + align:start position:0% +things +right so some stuff breaks down + + align:start position:0% +right so some stuff breaks down + + + align:start position:0% +right so some stuff breaks down +in our interface right so i would + + align:start position:0% +in our interface right so i would + + + align:start position:0% +in our interface right so i would +prefer you use unique keys in this this + + align:start position:0% +prefer you use unique keys in this this + + + align:start position:0% +prefer you use unique keys in this this +kind of situation + + align:start position:0% +kind of situation + + + align:start position:0% +kind of situation +next tuesday i think with binary heaps + + align:start position:0% +next tuesday i think with binary heaps + + + align:start position:0% +next tuesday i think with binary heaps +uh we'll deal with + + align:start position:0% +uh we'll deal with + + + align:start position:0% +uh we'll deal with +non-unique keys that's fine but + + align:start position:0% +non-unique keys that's fine but + + + align:start position:0% +non-unique keys that's fine but +if you're gonna use non-unique keys in + + align:start position:0% +if you're gonna use non-unique keys in + + + align:start position:0% +if you're gonna use non-unique keys in +here + + align:start position:0% +here + + + align:start position:0% +here +you just gotta be a little bit careful + + align:start position:0% +you just gotta be a little bit careful + + + align:start position:0% +you just gotta be a little bit careful +about the semantics + + align:start position:0% +about the semantics + + + align:start position:0% +about the semantics +okay yep + + align:start position:0% + + + + align:start position:0% + +uh so you get the same uh + + align:start position:0% +uh so you get the same uh + + + align:start position:0% +uh so you get the same uh +running time you the you have to change + + align:start position:0% +running time you the you have to change + + + align:start position:0% +running time you the you have to change +the semantics on what you mean by find + + align:start position:0% +the semantics on what you mean by find + + + align:start position:0% +the semantics on what you mean by find +something + + align:start position:0% +something + + + align:start position:0% +something +right i just want to return anything + + align:start position:0% +right i just want to return anything + + + align:start position:0% +right i just want to return anything +with this key + + align:start position:0% +with this key + + + align:start position:0% +with this key +right what if everything has the same + + align:start position:0% +right what if everything has the same + + + align:start position:0% +right what if everything has the same +key then it takes constant time + + align:start position:0% +key then it takes constant time + + + align:start position:0% +key then it takes constant time +i just returned the first thing + + align:start position:0% +i just returned the first thing + + + align:start position:0% +i just returned the first thing +it's i mean these are special cases that + + align:start position:0% +it's i mean these are special cases that + + + align:start position:0% +it's i mean these are special cases that +you know you have to think about right + + align:start position:0% +you know you have to think about right + + + align:start position:0% +you know you have to think about right +uh i don't like thinking about them + + align:start position:0% +uh i don't like thinking about them + + + align:start position:0% +uh i don't like thinking about them +right so i just like + + align:start position:0% +right so i just like + + + align:start position:0% +right so i just like +having unique keys and if i want a + + align:start position:0% +having unique keys and if i want a + + + align:start position:0% +having unique keys and if i want a +situation where i have non-unique keys + + align:start position:0% +situation where i have non-unique keys + + + align:start position:0% +situation where i have non-unique keys +i'm going to basically put collisions at + + align:start position:0% +i'm going to basically put collisions at + + + align:start position:0% +i'm going to basically put collisions at +that key + + align:start position:0% +that key + + + align:start position:0% +that key +into a new data structure right it's + + align:start position:0% +into a new data structure right it's + + + align:start position:0% +into a new data structure right it's +just easier for me to separate out my + + align:start position:0% +just easier for me to separate out my + + + align:start position:0% +just easier for me to separate out my +head + + align:start position:0% +head + + + align:start position:0% +head +on what's happening because all of the + + align:start position:0% +on what's happening because all of the + + + align:start position:0% +on what's happening because all of the +running times that we proposed + + align:start position:0% +running times that we proposed + + + align:start position:0% +running times that we proposed +you know very strong definitions for + + align:start position:0% +you know very strong definitions for + + + align:start position:0% +you know very strong definitions for +unique key + + align:start position:0% +unique key + + + align:start position:0% +unique key +you know when you're dealing with a + + align:start position:0% +you know when you're dealing with a + + + align:start position:0% +you know when you're dealing with a +multi-set it's a little bit more + + align:start position:0% +multi-set it's a little bit more + + + align:start position:0% +multi-set it's a little bit more +problematic + + align:start position:0% +problematic + + + align:start position:0% +problematic +any other questions i we really need to + + align:start position:0% +any other questions i we really need to + + + align:start position:0% +any other questions i we really need to +kind of move on here + + align:start position:0% +kind of move on here + + + align:start position:0% +kind of move on here +right uh dictionary ketone bitter + + align:start position:0% +right uh dictionary ketone bitter + + + align:start position:0% +right uh dictionary ketone bitter +we still haven't implemented any dynamic + + align:start position:0% +we still haven't implemented any dynamic + + + align:start position:0% +we still haven't implemented any dynamic +operations + + align:start position:0% +operations + + + align:start position:0% +operations +new bid what do i do uh + + align:start position:0% +new bid what do i do uh + + + align:start position:0% +new bid what do i do uh +what am i going to need for my update + + align:start position:0% +what am i going to need for my update + + + align:start position:0% +what am i going to need for my update +i'm going to be able to + + align:start position:0% +i'm going to be able to + + + align:start position:0% +i'm going to be able to +need to essentially find in each of + + align:start position:0% +need to essentially find in each of + + + align:start position:0% +need to essentially find in each of +these data structures + + align:start position:0% +these data structures + + + align:start position:0% +these data structures +where that bidder is right + + align:start position:0% +where that bidder is right + + + align:start position:0% +where that bidder is right +and if i just have a thing keyed on + + align:start position:0% +and if i just have a thing keyed on + + + align:start position:0% +and if i just have a thing keyed on +their bid + + align:start position:0% +their bid + + + align:start position:0% +their bid +right the interface doesn't tell me what + + align:start position:0% +right the interface doesn't tell me what + + + align:start position:0% +right the interface doesn't tell me what +their old bid was + + align:start position:0% +their old bid was + + + align:start position:0% +their old bid was +it just tells me what their bidder id is + + align:start position:0% +it just tells me what their bidder id is + + + align:start position:0% +it just tells me what their bidder id is +right so if i just had their bidder id + + align:start position:0% +right so if i just had their bidder id + + + align:start position:0% +right so if i just had their bidder id +and their new bid how the heck am i + + align:start position:0% +and their new bid how the heck am i + + + align:start position:0% +and their new bid how the heck am i +going to find out + + align:start position:0% +going to find out + + + align:start position:0% +going to find out +which of these dash or where in these + + align:start position:0% +which of these dash or where in these + + + align:start position:0% +which of these dash or where in these +data structures they are + + align:start position:0% +data structures they are + + + align:start position:0% +data structures they are +right what i can do is i can store + + align:start position:0% +right what i can do is i can store + + + align:start position:0% +right what i can do is i can store +in this dictionary which i can look up + + align:start position:0% +in this dictionary which i can look up + + + align:start position:0% +in this dictionary which i can look up +in some amount of time right a pointer + + align:start position:0% +in some amount of time right a pointer + + + align:start position:0% +in some amount of time right a pointer +to where it exists in these things + + align:start position:0% +to where it exists in these things + + + align:start position:0% +to where it exists in these things +does that make sense this is called + + align:start position:0% +does that make sense this is called + + + align:start position:0% +does that make sense this is called +cross linking you may have + + align:start position:0% +cross linking you may have + + + align:start position:0% +cross linking you may have +done that a little bit in problem set + + align:start position:0% +done that a little bit in problem set + + + align:start position:0% +done that a little bit in problem set +two or something like that + + align:start position:0% +two or something like that + + + align:start position:0% +two or something like that +yeah are we storing a pointer to a + + align:start position:0% +yeah are we storing a pointer to a + + + align:start position:0% +yeah are we storing a pointer to a +specific figure + + align:start position:0% +specific figure + + + align:start position:0% +specific figure +yeah exactly right so the the invariant + + align:start position:0% +yeah exactly right so the the invariant + + + align:start position:0% +yeah exactly right so the the invariant +we have is that all of the bidders we've + + align:start position:0% +we have is that all of the bidders we've + + + align:start position:0% +we have is that all of the bidders we've +processed so far exist in these data + + align:start position:0% +processed so far exist in these data + + + align:start position:0% +processed so far exist in these data +structures + + align:start position:0% +structures + + + align:start position:0% +structures +right in one of these data structures + + align:start position:0% +right in one of these data structures + + + align:start position:0% +right in one of these data structures +and because we've used a set avl tree + + align:start position:0% +and because we've used a set avl tree + + + align:start position:0% +and because we've used a set avl tree +right + + align:start position:0% +right + + + align:start position:0% +right +in particular exists in a node of one of + + align:start position:0% +in particular exists in a node of one of + + + align:start position:0% +in particular exists in a node of one of +these data structures + + align:start position:0% +these data structures + + + align:start position:0% +these data structures +right what we can do is in this thing + + align:start position:0% +right what we can do is in this thing + + + align:start position:0% +right what we can do is in this thing +maintain pointers right + + align:start position:0% +maintain pointers right + + + align:start position:0% +maintain pointers right +mapping each of the bitter ids to their + + align:start position:0% +mapping each of the bitter ids to their + + + align:start position:0% +mapping each of the bitter ids to their +location in these data structures + + align:start position:0% +location in these data structures + + + align:start position:0% +location in these data structures +and why is that going to be a useful + + align:start position:0% +and why is that going to be a useful + + + align:start position:0% +and why is that going to be a useful +thing + + align:start position:0% +thing + + + align:start position:0% +thing +right uh say i mapped this dictionary + + align:start position:0% +right uh say i mapped this dictionary + + + align:start position:0% +right uh say i mapped this dictionary +right + + align:start position:0% +right + + + align:start position:0% +right +what could i use for this dictionary to + + align:start position:0% +what could i use for this dictionary to + + + align:start position:0% +what could i use for this dictionary to +get the running time we're looking for + + align:start position:0% +get the running time we're looking for + + + align:start position:0% +get the running time we're looking for +i could use a hash table or a set avl + + align:start position:0% +i could use a hash table or a set avl + + + align:start position:0% +i could use a hash table or a set avl +right if it's set avl + + align:start position:0% +right if it's set avl + + + align:start position:0% +right if it's set avl +i'm going to get logarithmic time worst + + align:start position:0% +i'm going to get logarithmic time worst + + + align:start position:0% +i'm going to get logarithmic time worst +case + + align:start position:0% +case + + + align:start position:0% +case +with a hash table i'm going to get + + align:start position:0% +with a hash table i'm going to get + + + align:start position:0% +with a hash table i'm going to get +constant time but it's expected right so + + align:start position:0% +constant time but it's expected right so + + + align:start position:0% +constant time but it's expected right so +it could be linear time in the worst + + align:start position:0% +it could be linear time in the worst + + + align:start position:0% +it could be linear time in the worst +case + + align:start position:0% +case + + + align:start position:0% +case +right so we're going to use a set avl + + align:start position:0% +right so we're going to use a set avl + + + align:start position:0% +right so we're going to use a set avl +tree right because that's what we do + + align:start position:0% +tree right because that's what we do + + + align:start position:0% +tree right because that's what we do +right now and that's going to give us + + align:start position:0% +right now and that's going to give us + + + align:start position:0% +right now and that's going to give us +worst case + + align:start position:0% +worst case + + + align:start position:0% +worst case +okay so what i'm going to do is for each + + align:start position:0% +okay so what i'm going to do is for each + + + align:start position:0% +okay so what i'm going to do is for each +one of these things i'm going to store + + align:start position:0% +one of these things i'm going to store + + + align:start position:0% +one of these things i'm going to store +that pointer so what i'm going to do + + align:start position:0% +that pointer so what i'm going to do + + + align:start position:0% +that pointer so what i'm going to do +is first i'm going to do that operation + + align:start position:0% +is first i'm going to do that operation + + + align:start position:0% +is first i'm going to do that operation +we had + + align:start position:0% +we had + + + align:start position:0% +we had +if i'm adding a new bitter right i'm + + align:start position:0% +if i'm adding a new bitter right i'm + + + align:start position:0% +if i'm adding a new bitter right i'm +going to take + + align:start position:0% +going to take + + + align:start position:0% +going to take +the you know the d and b right + + align:start position:0% +the you know the d and b right + + + align:start position:0% +the you know the d and b right +these two values that object that's + + align:start position:0% +these two values that object that's + + + align:start position:0% +these two values that object that's +that that bitter object or whatever i'm + + align:start position:0% +that that bitter object or whatever i'm + + + align:start position:0% +that that bitter object or whatever i'm +going to look at the smallest thing in + + align:start position:0% +going to look at the smallest thing in + + + align:start position:0% +going to look at the smallest thing in +this + + align:start position:0% +this + + + align:start position:0% +this +data structure right see if it's bid + + align:start position:0% +data structure right see if it's bid + + + align:start position:0% +data structure right see if it's bid +is bigger than my + + align:start position:0% +is bigger than my + + + align:start position:0% +is bigger than my +my the the thing i'm inserting right if + + align:start position:0% +my the the thing i'm inserting right if + + + align:start position:0% +my the the thing i'm inserting right if +it is then i'm not going to touch this + + align:start position:0% +it is then i'm not going to touch this + + + align:start position:0% +it is then i'm not going to touch this +data structure i'm just going to insert + + align:start position:0% +data structure i'm just going to insert + + + align:start position:0% +data structure i'm just going to insert +it in here + + align:start position:0% +it in here + + + align:start position:0% +it in here +and now after i insert it in here i know + + align:start position:0% +and now after i insert it in here i know + + + align:start position:0% +and now after i insert it in here i know +exactly where it is in the data + + align:start position:0% +exactly where it is in the data + + + align:start position:0% +exactly where it is in the data +structure i just inserted it + + align:start position:0% +structure i just inserted it + + + align:start position:0% +structure i just inserted it +right right so now + + align:start position:0% +right right so now + + + align:start position:0% +right right so now +holding that in my hand the node right + + align:start position:0% +holding that in my hand the node right + + + align:start position:0% +holding that in my hand the node right +i can go and insert that bitter into + + align:start position:0% +i can go and insert that bitter into + + + align:start position:0% +i can go and insert that bitter into +here right + + align:start position:0% +here right + + + align:start position:0% +here right +by bit id right so it's going to take + + align:start position:0% +by bit id right so it's going to take + + + align:start position:0% +by bit id right so it's going to take +logarithmic time + + align:start position:0% +logarithmic time + + + align:start position:0% +logarithmic time +and now i can store with that node + + align:start position:0% +and now i can store with that node + + + align:start position:0% +and now i can store with that node +my pointer to this data structure does + + align:start position:0% +my pointer to this data structure does + + + align:start position:0% +my pointer to this data structure does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +and in the other case i kind of do the + + align:start position:0% +and in the other case i kind of do the + + + align:start position:0% +and in the other case i kind of do the +same thing right + + align:start position:0% +same thing right + + + align:start position:0% +same thing right +if it's bigger than the smallest thing + + align:start position:0% +if it's bigger than the smallest thing + + + align:start position:0% +if it's bigger than the smallest thing +here i pop that smaller thing out stick + + align:start position:0% +here i pop that smaller thing out stick + + + align:start position:0% +here i pop that smaller thing out stick +it in there + + align:start position:0% +it in there + + + align:start position:0% +it in there +and i stick my new guy in here + + align:start position:0% +and i stick my new guy in here + + + align:start position:0% +and i stick my new guy in here +cross-linking + + align:start position:0% +cross-linking + + + align:start position:0% +cross-linking +each of those pointers along the way + + align:start position:0% +each of those pointers along the way + + + align:start position:0% +each of those pointers along the way +does that make sense hopefully + + align:start position:0% +does that make sense hopefully + + + align:start position:0% +does that make sense hopefully +kind of kind of okay yeah + + align:start position:0% +kind of kind of okay yeah + + + align:start position:0% +kind of kind of okay yeah +and for update very similar right if i + + align:start position:0% +and for update very similar right if i + + + align:start position:0% +and for update very similar right if i +want to update + + align:start position:0% +want to update + + + align:start position:0% +want to update +a certain bidder i look in this data + + align:start position:0% +a certain bidder i look in this data + + + align:start position:0% +a certain bidder i look in this data +structure + + align:start position:0% +structure + + + align:start position:0% +structure +finds the bidder + + align:start position:0% +finds the bidder + + + align:start position:0% +finds the bidder +traverse that pointer to wherever it is + + align:start position:0% +traverse that pointer to wherever it is + + + align:start position:0% +traverse that pointer to wherever it is +in one of these avl trees + + align:start position:0% +in one of these avl trees + + + align:start position:0% +in one of these avl trees +right if it's in this if it's in this + + align:start position:0% +right if it's in this if it's in this + + + align:start position:0% +right if it's in this if it's in this +one + + align:start position:0% +one + + + align:start position:0% +one +i just remove it from the tree right or + + align:start position:0% +i just remove it from the tree right or + + + align:start position:0% +i just remove it from the tree right or +i remove it from the tree and then i + + align:start position:0% +i remove it from the tree and then i + + + align:start position:0% +i remove it from the tree and then i +reinsert + + align:start position:0% +reinsert + + + align:start position:0% +reinsert +right with whatever the new bit is right + + align:start position:0% +right with whatever the new bit is right + + + align:start position:0% +right with whatever the new bit is right +and if it's in this one again i remove + + align:start position:0% +and if it's in this one again i remove + + + align:start position:0% +and if it's in this one again i remove +it from the tree + + align:start position:0% +it from the tree + + + align:start position:0% +it from the tree +reinsert and whichever these things is + + align:start position:0% +reinsert and whichever these things is + + + align:start position:0% +reinsert and whichever these things is +and then i might have to you know swap a + + align:start position:0% +and then i might have to you know swap a + + + align:start position:0% +and then i might have to you know swap a +constant number of things back and forth + + align:start position:0% +constant number of things back and forth + + + align:start position:0% +constant number of things back and forth +here to maintain that this has the + + align:start position:0% +here to maintain that this has the + + + align:start position:0% +here to maintain that this has the +k highest right and when i do those + + align:start position:0% +k highest right and when i do those + + + align:start position:0% +k highest right and when i do those +dynamic operations + + align:start position:0% + + + + align:start position:0% + +i'm always removing some constant number + + align:start position:0% +i'm always removing some constant number + + + align:start position:0% +i'm always removing some constant number +of nodes in each of these trees and and + + align:start position:0% +of nodes in each of these trees and and + + + align:start position:0% +of nodes in each of these trees and and +adding back in a constant number of + + align:start position:0% +adding back in a constant number of + + + align:start position:0% +adding back in a constant number of +things and while i do that i just make + + align:start position:0% +things and while i do that i just make + + + align:start position:0% +things and while i do that i just make +sure to update this total as i go + + align:start position:0% +sure to update this total as i go + + + align:start position:0% +sure to update this total as i go +right his total was the sum of all of + + align:start position:0% +right his total was the sum of all of + + + align:start position:0% +right his total was the sum of all of +the + + align:start position:0% +the + + + align:start position:0% +the +bids in here and if i insert a new bid + + align:start position:0% +bids in here and if i insert a new bid + + + align:start position:0% +bids in here and if i insert a new bid +in here + + align:start position:0% +in here + + + align:start position:0% +in here +i have to add to that total and if i + + align:start position:0% +i have to add to that total and if i + + + align:start position:0% +i have to add to that total and if i +remove one i have to remove from that + + align:start position:0% +remove one i have to remove from that + + + align:start position:0% +remove one i have to remove from that +total but + + align:start position:0% +total but + + + align:start position:0% +total but +again it's a constant number of things + + align:start position:0% +again it's a constant number of things + + + align:start position:0% +again it's a constant number of things +i'm moving in and out of these data + + align:start position:0% +i'm moving in and out of these data + + + align:start position:0% +i'm moving in and out of these data +structures + + align:start position:0% +structures + + + align:start position:0% +structures +and so it can update this in constant + + align:start position:0% +and so it can update this in constant + + + align:start position:0% +and so it can update this in constant +time that makes sense + + align:start position:0% +time that makes sense + + + align:start position:0% +time that makes sense +now the look up here and the insertion + + align:start position:0% +now the look up here and the insertion + + + align:start position:0% +now the look up here and the insertion +and deletion into here + + align:start position:0% +and deletion into here + + + align:start position:0% +and deletion into here +those each took logarithmic time + + align:start position:0% +those each took logarithmic time + + + align:start position:0% +those each took logarithmic time +worst case but i did a constant number + + align:start position:0% +worst case but i did a constant number + + + align:start position:0% +worst case but i did a constant number +of them so + + align:start position:0% +of them so + + + align:start position:0% +of them so +again longer than time does that make + + align:start position:0% +again longer than time does that make + + + align:start position:0% +again longer than time does that make +sense that's + + align:start position:0% +sense that's + + + align:start position:0% +sense that's +that's essentially this problem it's a + + align:start position:0% +that's essentially this problem it's a + + + align:start position:0% +that's essentially this problem it's a +little + + align:start position:0% +little + + + align:start position:0% +little +it's difficult right there's a lot of + + align:start position:0% +it's difficult right there's a lot of + + + align:start position:0% +it's difficult right there's a lot of +moving parts here + + align:start position:0% +moving parts here + + + align:start position:0% +moving parts here +right but if you just break it up into + + align:start position:0% +right but if you just break it up into + + + align:start position:0% +right but if you just break it up into +describe to me and + + align:start position:0% +describe to me and + + + align:start position:0% +describe to me and +like you really do a good job on this + + align:start position:0% +like you really do a good job on this + + + align:start position:0% +like you really do a good job on this +part describe well + + align:start position:0% +part describe well + + + align:start position:0% +part describe well +to me what your data structure has then + + align:start position:0% +to me what your data structure has then + + + align:start position:0% +to me what your data structure has then +those descriptions of those algorithms + + align:start position:0% +those descriptions of those algorithms + + + align:start position:0% +those descriptions of those algorithms +can be + + align:start position:0% +can be + + + align:start position:0% +can be +pretty brief actually right so + + align:start position:0% +pretty brief actually right so + + + align:start position:0% +pretty brief actually right so +you know in this one you tell me these + + align:start position:0% +you know in this one you tell me these + + + align:start position:0% +you know in this one you tell me these +three data structures you tell me this + + align:start position:0% +three data structures you tell me this + + + align:start position:0% +three data structures you tell me this +guy's mapping to its location and these + + align:start position:0% +guy's mapping to its location and these + + + align:start position:0% +guy's mapping to its location and these +things + + align:start position:0% +things + + + align:start position:0% +things +i'm maintaining this guy right and then + + align:start position:0% +i'm maintaining this guy right and then + + + align:start position:0% +i'm maintaining this guy right and then +you just maintain those things with + + align:start position:0% +you just maintain those things with + + + align:start position:0% +you just maintain those things with +dynamic operations and then use + + align:start position:0% +dynamic operations and then use + + + align:start position:0% +dynamic operations and then use +those things for query operations that + + align:start position:0% +those things for query operations that + + + align:start position:0% +those things for query operations that +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +okay + + align:start position:0% + + + + align:start position:0% + +wow we have 10 more minutes + + align:start position:0% + + + + align:start position:0% + +i'm going to briefly do four or four + + align:start position:0% +i'm going to briefly do four or four + + + align:start position:0% +i'm going to briefly do four or four +okay + + align:start position:0% +okay + + + align:start position:0% +okay +for you okay receiver roster we've got a + + align:start position:0% +for you okay receiver roster we've got a + + + align:start position:0% +for you okay receiver roster we've got a +coach + + align:start position:0% + + + + align:start position:0% + +she's got a bunch of football players + + align:start position:0% +she's got a bunch of football players + + + align:start position:0% +she's got a bunch of football players +receivers + + align:start position:0% + + + + align:start position:0% + +and wanting to start on our team + + align:start position:0% +and wanting to start on our team + + + align:start position:0% +and wanting to start on our team +the uh some number of of players that + + align:start position:0% +the uh some number of of players that + + + align:start position:0% +the uh some number of of players that +have the best + + align:start position:0% +have the best + + + align:start position:0% +have the best +the highest performance okay and by + + align:start position:0% +the highest performance okay and by + + + align:start position:0% +the highest performance okay and by +performance we mean + + align:start position:0% +performance we mean + + + align:start position:0% +performance we mean +the average number of points they've + + align:start position:0% +the average number of points they've + + + align:start position:0% +the average number of points they've +played in games that they have logged in + + align:start position:0% +played in games that they have logged in + + + align:start position:0% +played in games that they have logged in +their system + + align:start position:0% +their system + + + align:start position:0% +their system +right but actually their data is + + align:start position:0% +right but actually their data is + + + align:start position:0% +right but actually their data is +incomplete + + align:start position:0% +incomplete + + + align:start position:0% +incomplete +right they don't know which games and + + align:start position:0% +right they don't know which games and + + + align:start position:0% +right they don't know which games and +how much they scored in all these things + + align:start position:0% +how much they scored in all these things + + + align:start position:0% +how much they scored in all these things +there could be errors + + align:start position:0% +there could be errors + + + align:start position:0% +there could be errors +right and so these interns they're up + + align:start position:0% +right and so these interns they're up + + + align:start position:0% +right and so these interns they're up +they're constantly updating this + + align:start position:0% +they're constantly updating this + + + align:start position:0% +they're constantly updating this +database with queries like + + align:start position:0% +database with queries like + + + align:start position:0% +database with queries like +uh oh uh + + align:start position:0% +uh oh uh + + + align:start position:0% +uh oh uh +you know never mind this person didn't + + align:start position:0% +you know never mind this person didn't + + + align:start position:0% +you know never mind this person didn't +play in this game + + align:start position:0% +play in this game + + + align:start position:0% +play in this game +or actually they did and they scored + + align:start position:0% +or actually they did and they scored + + + align:start position:0% +or actually they did and they scored +this number of points + + align:start position:0% +this number of points + + + align:start position:0% +this number of points +right that's the clear and record things + + align:start position:0% +right that's the clear and record things + + + align:start position:0% +right that's the clear and record things +right and then at some point in time + + align:start position:0% +right and then at some point in time + + + align:start position:0% +right and then at some point in time +right like when we start + + align:start position:0% +right like when we start + + + align:start position:0% +right like when we start +when we want to play a game right i want + + align:start position:0% +when we want to play a game right i want + + + align:start position:0% +when we want to play a game right i want +to be able to return + + align:start position:0% +to be able to return + + + align:start position:0% +to be able to return +the the jersey with the k-th highest + + align:start position:0% +the the jersey with the k-th highest + + + align:start position:0% +the the jersey with the k-th highest +performance and log in time + + align:start position:0% +performance and log in time + + + align:start position:0% +performance and log in time +okay this is kind of a + + align:start position:0% +okay this is kind of a + + + align:start position:0% +okay this is kind of a +kind of a rank query right right the kth + + align:start position:0% +kind of a rank query right right the kth + + + align:start position:0% +kind of a rank query right right the kth +highest + + align:start position:0% +highest + + + align:start position:0% +highest +okay uh now in actuality i might want to + + align:start position:0% +okay uh now in actuality i might want to + + + align:start position:0% +okay uh now in actuality i might want to +return + + align:start position:0% +return + + + align:start position:0% +return +all k highest players so that that might + + align:start position:0% +all k highest players so that that might + + + align:start position:0% +all k highest players so that that might +be my + + align:start position:0% +be my + + + align:start position:0% +be my +my roster right but this is you know a + + align:start position:0% +my roster right but this is you know a + + + align:start position:0% +my roster right but this is you know a +more generalized query + + align:start position:0% +more generalized query + + + align:start position:0% +more generalized query +it's more specific more it's it's + + align:start position:0% +it's more specific more it's it's + + + align:start position:0% +it's more specific more it's it's +not really comparable but you get an + + align:start position:0% +not really comparable but you get an + + + align:start position:0% +not really comparable but you get an +idea for why that might be useful to the + + align:start position:0% +idea for why that might be useful to the + + + align:start position:0% +idea for why that might be useful to the +coach + + align:start position:0% +coach + + + align:start position:0% +coach +i don't know maybe not okay so what's + + align:start position:0% +i don't know maybe not okay so what's + + + align:start position:0% +i don't know maybe not okay so what's +the idea here + + align:start position:0% +the idea here + + + align:start position:0% +the idea here +we have a lot of different things + + align:start position:0% +we have a lot of different things + + + align:start position:0% +we have a lot of different things +floating around we got games + + align:start position:0% +floating around we got games + + + align:start position:0% +floating around we got games +they have ids unique ids we got + + align:start position:0% +they have ids unique ids we got + + + align:start position:0% +they have ids unique ids we got +receivers they have unique ids + + align:start position:0% +receivers they have unique ids + + + align:start position:0% +receivers they have unique ids +and each receiver could play in many + + align:start position:0% +and each receiver could play in many + + + align:start position:0% +and each receiver could play in many +games + + align:start position:0% +games + + + align:start position:0% +games +right oh that's kind of worrisome + + align:start position:0% +right oh that's kind of worrisome + + + align:start position:0% +right oh that's kind of worrisome +and many receivers could play in the + + align:start position:0% +and many receivers could play in the + + + align:start position:0% +and many receivers could play in the +same game + + align:start position:0% +same game + + + align:start position:0% +same game +these kind of many-to-one mappings are a + + align:start position:0% +these kind of many-to-one mappings are a + + + align:start position:0% +these kind of many-to-one mappings are a +little confusing + + align:start position:0% +little confusing + + + align:start position:0% +little confusing +and then we've got each player + + align:start position:0% + + + + align:start position:0% + +receiver having a certain number of + + align:start position:0% +receiver having a certain number of + + + align:start position:0% +receiver having a certain number of +points per game + + align:start position:0% +points per game + + + align:start position:0% +points per game +and we're trying to sort them kind of by + + align:start position:0% +and we're trying to sort them kind of by + + + align:start position:0% +and we're trying to sort them kind of by +their performance which is a rational + + align:start position:0% +their performance which is a rational + + + align:start position:0% +their performance which is a rational +number + + align:start position:0% +number + + + align:start position:0% +number +right which has to do with the number of + + align:start position:0% +right which has to do with the number of + + + align:start position:0% +right which has to do with the number of +games they've played + + align:start position:0% +games they've played + + + align:start position:0% +games they've played +and the total number of points right + + align:start position:0% +and the total number of points right + + + align:start position:0% +and the total number of points right +now i see rational number i can't + + align:start position:0% +now i see rational number i can't + + + align:start position:0% +now i see rational number i can't +compute that + + align:start position:0% +compute that + + + align:start position:0% +compute that +right that's what we were talking about + + align:start position:0% +right that's what we were talking about + + + align:start position:0% +right that's what we were talking about +last problem session right + + align:start position:0% +last problem session right + + + align:start position:0% +last problem session right +but what i can do is i could store the + + align:start position:0% +but what i can do is i could store the + + + align:start position:0% +but what i can do is i could store the +total number of games they played and + + align:start position:0% +total number of games they played and + + + align:start position:0% +total number of games they played and +the total number of points they had + + align:start position:0% +the total number of points they had + + + align:start position:0% +the total number of points they had +right and you could imagine by + + align:start position:0% +right and you could imagine by + + + align:start position:0% +right and you could imagine by +augmentation similar to this + + align:start position:0% +augmentation similar to this + + + align:start position:0% +augmentation similar to this +right every time i add a game + + align:start position:0% +right every time i add a game + + + align:start position:0% +right every time i add a game +right one of these small operations i + + align:start position:0% +right one of these small operations i + + + align:start position:0% +right one of these small operations i +can + + align:start position:0% +can + + + align:start position:0% +can +update that information for each player + + align:start position:0% +update that information for each player + + + align:start position:0% +update that information for each player +right + + align:start position:0% +right + + + align:start position:0% +right +right if i'm just if one of these these + + align:start position:0% +right if i'm just if one of these these + + + align:start position:0% +right if i'm just if one of these these +dynamic operations is affecting only one + + align:start position:0% +dynamic operations is affecting only one + + + align:start position:0% +dynamic operations is affecting only one +receiver + + align:start position:0% +receiver + + + align:start position:0% +receiver +i can you know update whatever it is in + + align:start position:0% +i can you know update whatever it is in + + + align:start position:0% +i can you know update whatever it is in +in constant time probably right if i + + align:start position:0% +in constant time probably right if i + + + align:start position:0% +in constant time probably right if i +just store with the player + + align:start position:0% +just store with the player + + + align:start position:0% +just store with the player +what their total number of games is as + + align:start position:0% +what their total number of games is as + + + align:start position:0% +what their total number of games is as +recorded by the database + + align:start position:0% +recorded by the database + + + align:start position:0% +recorded by the database +and how many points they've scored then + + align:start position:0% +and how many points they've scored then + + + align:start position:0% +and how many points they've scored then +if i have a data structure + + align:start position:0% +if i have a data structure + + + align:start position:0% +if i have a data structure +that needs to sort + + align:start position:0% +that needs to sort + + + align:start position:0% +that needs to sort +the receivers by their performance so i + + align:start position:0% +the receivers by their performance so i + + + align:start position:0% +the receivers by their performance so i +might be able to find the kth one + + align:start position:0% +might be able to find the kth one + + + align:start position:0% +might be able to find the kth one +right the k largest then + + align:start position:0% +right the k largest then + + + align:start position:0% +right the k largest then +i can't compute that performance but + + align:start position:0% +i can't compute that performance but + + + align:start position:0% +i can't compute that performance but +what can i do + + align:start position:0% +what can i do + + + align:start position:0% +what can i do +i can compare two players based on their + + align:start position:0% +i can compare two players based on their + + + align:start position:0% +i can compare two players based on their +performance using cross multiplication + + align:start position:0% +performance using cross multiplication + + + align:start position:0% +performance using cross multiplication +right right because i have the numerator + + align:start position:0% +right right because i have the numerator + + + align:start position:0% +right right because i have the numerator +and denominator of each of these + + align:start position:0% +and denominator of each of these + + + align:start position:0% +and denominator of each of these +rationals and i can cross multiply + + align:start position:0% +rationals and i can cross multiply + + + align:start position:0% +rationals and i can cross multiply +and figure out whether one's bigger or + + align:start position:0% +and figure out whether one's bigger or + + + align:start position:0% +and figure out whether one's bigger or +smaller and as long as i have a + + align:start position:0% +smaller and as long as i have a + + + align:start position:0% +smaller and as long as i have a +comparator + + align:start position:0% +comparator + + + align:start position:0% +comparator +i can do set jbl stuff does that make + + align:start position:0% +i can do set jbl stuff does that make + + + align:start position:0% +i can do set jbl stuff does that make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so that's the i'm just going to + + align:start position:0% +okay so that's the i'm just going to + + + align:start position:0% +okay so that's the i'm just going to +outline kind of the + + align:start position:0% +outline kind of the + + + align:start position:0% +outline kind of the +the components of this data structure + + align:start position:0% +the components of this data structure + + + align:start position:0% +the components of this data structure +okay well first off uh i'm gonna need to + + align:start position:0% +okay well first off uh i'm gonna need to + + + align:start position:0% +okay well first off uh i'm gonna need to +record a receiver and a receiver could + + align:start position:0% +record a receiver and a receiver could + + + align:start position:0% +record a receiver and a receiver could +have a lot of games + + align:start position:0% +have a lot of games + + + align:start position:0% +have a lot of games +but the important this is kind of a + + align:start position:0% +but the important this is kind of a + + + align:start position:0% +but the important this is kind of a +receiver centric kind of problem does + + align:start position:0% +receiver centric kind of problem does + + + align:start position:0% +receiver centric kind of problem does +that make sense to you guys + + align:start position:0% +that make sense to you guys + + + align:start position:0% +that make sense to you guys +right i'm not ever wanting to filter on + + align:start position:0% +right i'm not ever wanting to filter on + + + align:start position:0% +right i'm not ever wanting to filter on +all the receivers playing a game + + align:start position:0% +all the receivers playing a game + + + align:start position:0% +all the receivers playing a game +right i'm never like removing + + align:start position:0% + + + + align:start position:0% + +i'm never removing a game from the + + align:start position:0% +i'm never removing a game from the + + + align:start position:0% +i'm never removing a game from the +system i'm removing a + + align:start position:0% +system i'm removing a + + + align:start position:0% +system i'm removing a +receiver from ever playing in a specific + + align:start position:0% +receiver from ever playing in a specific + + + align:start position:0% +receiver from ever playing in a specific +game does that make sense + + align:start position:0% +game does that make sense + + + align:start position:0% +game does that make sense +so if i'm storing a receiver and each + + align:start position:0% +so if i'm storing a receiver and each + + + align:start position:0% +so if i'm storing a receiver and each +receiver has + + align:start position:0% +receiver has + + + align:start position:0% +receiver has +some games associated with them kind of + + align:start position:0% +some games associated with them kind of + + + align:start position:0% +some games associated with them kind of +makes sense i might want to have + + align:start position:0% +makes sense i might want to have + + + align:start position:0% +makes sense i might want to have +a nested data structure right where + + align:start position:0% +a nested data structure right where + + + align:start position:0% +a nested data structure right where +with maybe i have a a dictionary on + + align:start position:0% +with maybe i have a a dictionary on + + + align:start position:0% +with maybe i have a a dictionary on +receivers + + align:start position:0% +receivers + + + align:start position:0% +receivers +and for each one i store all the games + + align:start position:0% +and for each one i store all the games + + + align:start position:0% +and for each one i store all the games +that they've played it + + align:start position:0% +that they've played it + + + align:start position:0% +that they've played it +in some other data structure right with + + align:start position:0% +in some other data structure right with + + + align:start position:0% +in some other data structure right with +each receiver + + align:start position:0% +each receiver + + + align:start position:0% +each receiver +i store another its own data structure + + align:start position:0% +i store another its own data structure + + + align:start position:0% +i store another its own data structure +containing all its games so that makes + + align:start position:0% +containing all its games so that makes + + + align:start position:0% +containing all its games so that makes +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so that's the idea right we have + + align:start position:0% +okay so that's the idea right we have + + + align:start position:0% +okay so that's the idea right we have +some kind of + + align:start position:0% +some kind of + + + align:start position:0% +some kind of +i need to be able to look up receivers + + align:start position:0% +i need to be able to look up receivers + + + align:start position:0% +i need to be able to look up receivers +right because uh you know i'm i'm + + align:start position:0% +right because uh you know i'm i'm + + + align:start position:0% +right because uh you know i'm i'm +clearing them or i'm + + align:start position:0% +clearing them or i'm + + + align:start position:0% +clearing them or i'm +recording them right so i'm gonna have a + + align:start position:0% +recording them right so i'm gonna have a + + + align:start position:0% +recording them right so i'm gonna have a +you know + + align:start position:0% +you know + + + align:start position:0% +you know +a dictionary or you know here i'm + + align:start position:0% +a dictionary or you know here i'm + + + align:start position:0% +a dictionary or you know here i'm +looking for worst case login time + + align:start position:0% +looking for worst case login time + + + align:start position:0% +looking for worst case login time +so i'm going to you know skip the + + align:start position:0% +so i'm going to you know skip the + + + align:start position:0% +so i'm going to you know skip the +dictionary abstraction and go straight + + align:start position:0% +dictionary abstraction and go straight + + + align:start position:0% +dictionary abstraction and go straight +for the set avl + + align:start position:0% +for the set avl + + + align:start position:0% +for the set avl +avl uh + + align:start position:0% +avl uh + + + align:start position:0% +avl uh +uh keyed + + align:start position:0% + + + + align:start position:0% + +on receivers + + align:start position:0% +on receivers + + + align:start position:0% +on receivers +i before c e except after c + + align:start position:0% + + + + align:start position:0% + +it is i e i + + align:start position:0% +it is i e i + + + align:start position:0% +it is i e i +okay that rule never works + + align:start position:0% +okay that rule never works + + + align:start position:0% +okay that rule never works +okay uh set avl tree on receivers + + align:start position:0% +okay uh set avl tree on receivers + + + align:start position:0% +okay uh set avl tree on receivers +and each one of those nodes right with + + align:start position:0% +and each one of those nodes right with + + + align:start position:0% +and each one of those nodes right with +each one of those receivers + + align:start position:0% +each one of those receivers + + + align:start position:0% +each one of those receivers +i'm going to store for each + + align:start position:0% +i'm going to store for each + + + align:start position:0% +i'm going to store for each +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +store a set + + align:start position:0% +store a set + + + align:start position:0% +store a set +avl on games + + align:start position:0% +avl on games + + + align:start position:0% +avl on games +okay why do i store a set avl on games + + align:start position:0% +okay why do i store a set avl on games + + + align:start position:0% +okay why do i store a set avl on games +why don't i just store a list of all the + + align:start position:0% +why don't i just store a list of all the + + + align:start position:0% +why don't i just store a list of all the +games + + align:start position:0% + + + + align:start position:0% + +because if i want to remove this game + + align:start position:0% +because if i want to remove this game + + + align:start position:0% +because if i want to remove this game +from a receiver i need to do that in + + align:start position:0% +from a receiver i need to do that in + + + align:start position:0% +from a receiver i need to do that in +login time and + + align:start position:0% +login time and + + + align:start position:0% +login time and +here what we're saying is that n is the + + align:start position:0% +here what we're saying is that n is the + + + align:start position:0% +here what we're saying is that n is the +number of games + + align:start position:0% +number of games + + + align:start position:0% +number of games +but the the number of receivers on the + + align:start position:0% +but the the number of receivers on the + + + align:start position:0% +but the the number of receivers on the +team is always less than the number of + + align:start position:0% +team is always less than the number of + + + align:start position:0% +team is always less than the number of +games so + + align:start position:0% +games so + + + align:start position:0% +games so +right if i search in this avl tree + + align:start position:0% +right if i search in this avl tree + + + align:start position:0% +right if i search in this avl tree +and i search in its avl tree i can + + align:start position:0% +and i search in its avl tree i can + + + align:start position:0% +and i search in its avl tree i can +be assured that those two searches was + + align:start position:0% +be assured that those two searches was + + + align:start position:0% +be assured that those two searches was +only login + + align:start position:0% +only login + + + align:start position:0% +only login +yeah because i might i need to remove a + + align:start position:0% +yeah because i might i need to remove a + + + align:start position:0% +yeah because i might i need to remove a +game right so + + align:start position:0% +game right so + + + align:start position:0% +game right so +there you go then + + align:start position:0% +there you go then + + + align:start position:0% +there you go then +what am i doing i'm returning the k + + align:start position:0% +what am i doing i'm returning the k + + + align:start position:0% +what am i doing i'm returning the k +highest performance well i need for with + + align:start position:0% +highest performance well i need for with + + + align:start position:0% +highest performance well i need for with +each one of these guys + + align:start position:0% +each one of these guys + + + align:start position:0% +each one of these guys +i also store what was this augmentation + + align:start position:0% +i also store what was this augmentation + + + align:start position:0% +i also store what was this augmentation +the sum of the points stored in these + + align:start position:0% +the sum of the points stored in these + + + align:start position:0% +the sum of the points stored in these +games right + + align:start position:0% + + + + align:start position:0% + +sum of points + + align:start position:0% + + + + align:start position:0% + +and uh what was it + + align:start position:0% +and uh what was it + + + align:start position:0% +and uh what was it +number games + + align:start position:0% +number games + + + align:start position:0% +number games +because if i store both of those things + + align:start position:0% +because if i store both of those things + + + align:start position:0% +because if i store both of those things +in constant time i'm going to be able to + + align:start position:0% +in constant time i'm going to be able to + + + align:start position:0% +in constant time i'm going to be able to +compute + + align:start position:0% +compute + + + align:start position:0% +compute +their performance right where i'm going + + align:start position:0% +their performance right where i'm going + + + align:start position:0% +their performance right where i'm going +to be able to + + align:start position:0% +to be able to + + + align:start position:0% +to be able to +you have the data i need to compare + + align:start position:0% +you have the data i need to compare + + + align:start position:0% +you have the data i need to compare +performances yeah so you just don't + + align:start position:0% +performances yeah so you just don't + + + align:start position:0% +performances yeah so you just don't +have variables yeah yeah it's just + + align:start position:0% +have variables yeah yeah it's just + + + align:start position:0% +have variables yeah yeah it's just +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +right these aren't data structures this + + align:start position:0% +right these aren't data structures this + + + align:start position:0% +right these aren't data structures this +is data structure these are just numbers + + align:start position:0% +is data structure these are just numbers + + + align:start position:0% +is data structure these are just numbers +okay i'm storing that with each receiver + + align:start position:0% +okay i'm storing that with each receiver + + + align:start position:0% +okay i'm storing that with each receiver +right but that's not going to help me + + align:start position:0% +right but that's not going to help me + + + align:start position:0% +right but that's not going to help me +find the kth + + align:start position:0% +find the kth + + + align:start position:0% +find the kth +highest player right none of these + + align:start position:0% +highest player right none of these + + + align:start position:0% +highest player right none of these +things are sorted by performance right + + align:start position:0% +things are sorted by performance right + + + align:start position:0% +things are sorted by performance right +so i need the last data structure + + align:start position:0% + + + + align:start position:0% + +five + + align:start position:0% + + + + align:start position:0% + +i need to store something dynamically + + align:start position:0% +i need to store something dynamically + + + align:start position:0% +i need to store something dynamically +sorted by + + align:start position:0% +sorted by + + + align:start position:0% +sorted by +performance so yeah + + align:start position:0% +performance so yeah + + + align:start position:0% +performance so yeah +set avl storing + + align:start position:0% +set avl storing + + + align:start position:0% +set avl storing +receivers + + align:start position:0% + + + + align:start position:0% + +keyed on + + align:start position:0% +keyed on + + + align:start position:0% +keyed on +performance now when i say keyed ketone + + align:start position:0% +performance now when i say keyed ketone + + + align:start position:0% +performance now when i say keyed ketone +performance + + align:start position:0% +performance + + + align:start position:0% +performance +you want to mention something about the + + align:start position:0% +you want to mention something about the + + + align:start position:0% +you want to mention something about the +cross multiplication + + align:start position:0% +cross multiplication + + + align:start position:0% +cross multiplication +right like i'm storing with each one of + + align:start position:0% +right like i'm storing with each one of + + + align:start position:0% +right like i'm storing with each one of +these things this augmentation + + align:start position:0% +these things this augmentation + + + align:start position:0% +these things this augmentation +and when i'm comparing two things i'm + + align:start position:0% +and when i'm comparing two things i'm + + + align:start position:0% +and when i'm comparing two things i'm +using cross multiplication + + align:start position:0% +using cross multiplication + + + align:start position:0% +using cross multiplication +but other than that then we can abstract + + align:start position:0% +but other than that then we can abstract + + + align:start position:0% +but other than that then we can abstract +it away right you've + + align:start position:0% +it away right you've + + + align:start position:0% +it away right you've +abstracted that function call and i can + + align:start position:0% +abstracted that function call and i can + + + align:start position:0% +abstracted that function call and i can +imagine comparing two keys i can do this + + align:start position:0% +imagine comparing two keys i can do this + + + align:start position:0% +imagine comparing two keys i can do this +right this is a theory thing i'm not + + align:start position:0% +right this is a theory thing i'm not + + + align:start position:0% +right this is a theory thing i'm not +asking you to implement that + + align:start position:0% +asking you to implement that + + + align:start position:0% +asking you to implement that +right but that's sufficient for me as a + + align:start position:0% +right but that's sufficient for me as a + + + align:start position:0% +right but that's sufficient for me as a +reader of your solution + + align:start position:0% +reader of your solution + + + align:start position:0% +reader of your solution +to be able to say yeah you know what + + align:start position:0% +to be able to say yeah you know what + + + align:start position:0% +to be able to say yeah you know what +you're talking about + + align:start position:0% +you're talking about + + + align:start position:0% +you're talking about +okay all right so how do i connect these + + align:start position:0% +okay all right so how do i connect these + + + align:start position:0% +okay all right so how do i connect these +things + + align:start position:0% +things + + + align:start position:0% +things +right the thing is i'm going to need to + + align:start position:0% +right the thing is i'm going to need to + + + align:start position:0% +right the thing is i'm going to need to +be uh i need to update this + + align:start position:0% +be uh i need to update this + + + align:start position:0% +be uh i need to update this +these things right when i + + align:start position:0% +these things right when i + + + align:start position:0% +these things right when i +insert or remove a game right + + align:start position:0% + + + + align:start position:0% + +so how do i know where these receivers + + align:start position:0% +so how do i know where these receivers + + + align:start position:0% +so how do i know where these receivers +are + + align:start position:0% +are + + + align:start position:0% +are +in this thing i store a pointer into + + align:start position:0% +in this thing i store a pointer into + + + align:start position:0% +in this thing i store a pointer into +this data structure right + + align:start position:0% +this data structure right + + + align:start position:0% +this data structure right +so up here i store a pointer + + align:start position:0% + + + + align:start position:0% + +right to where it is in the data + + align:start position:0% +right to where it is in the data + + + align:start position:0% +right to where it is in the data +structure right again i'm storing all + + align:start position:0% +structure right again i'm storing all + + + align:start position:0% +structure right again i'm storing all +the receivers + + align:start position:0% +the receivers + + + align:start position:0% +the receivers +this has the same size as the number one + + align:start position:0% +this has the same size as the number one + + + align:start position:0% +this has the same size as the number one +data structure up there + + align:start position:0% +data structure up there + + + align:start position:0% +data structure up there +has the same number of receivers right + + align:start position:0% + + + + align:start position:0% + +but we're not quite done yet because i'm + + align:start position:0% +but we're not quite done yet because i'm + + + align:start position:0% +but we're not quite done yet because i'm +not wanting to know + + align:start position:0% +not wanting to know + + + align:start position:0% +not wanting to know +like who has the the best + + align:start position:0% +like who has the the best + + + align:start position:0% +like who has the the best +performance right i want to know who has + + align:start position:0% +performance right i want to know who has + + + align:start position:0% +performance right i want to know who has +the + + align:start position:0% +the + + + align:start position:0% +the +kaith best performance ugh + + align:start position:0% +kaith best performance ugh + + + align:start position:0% +kaith best performance ugh +how do i find the kate best thing in + + align:start position:0% +how do i find the kate best thing in + + + align:start position:0% +how do i find the kate best thing in +this treat right i've got a tree + + align:start position:0% +this treat right i've got a tree + + + align:start position:0% +this treat right i've got a tree +right set avl tree it's + + align:start position:0% +right set avl tree it's + + + align:start position:0% +right set avl tree it's +mapped on performance right i know where + + align:start position:0% +mapped on performance right i know where + + + align:start position:0% +mapped on performance right i know where +the last one is + + align:start position:0% +the last one is + + + align:start position:0% +the last one is +but if i want to find the kate one from + + align:start position:0% +but if i want to find the kate one from + + + align:start position:0% +but if i want to find the kate one from +the end how do i do that + + align:start position:0% + + + + align:start position:0% + +it's an avl tree a set avl tree + + align:start position:0% +it's an avl tree a set avl tree + + + align:start position:0% +it's an avl tree a set avl tree +all i'm storing is heights is there an + + align:start position:0% +all i'm storing is heights is there an + + + align:start position:0% +all i'm storing is heights is there an +operation that you've + + align:start position:0% +operation that you've + + + align:start position:0% +operation that you've +thought about you're not storing the + + align:start position:0% +thought about you're not storing the + + + align:start position:0% +thought about you're not storing the +size of each + + align:start position:0% +size of each + + + align:start position:0% +size of each +ah a set avl tree by default does not + + align:start position:0% +ah a set avl tree by default does not + + + align:start position:0% +ah a set avl tree by default does not +store sizes right that's what a sequence + + align:start position:0% +store sizes right that's what a sequence + + + align:start position:0% +store sizes right that's what a sequence +does + + align:start position:0% +does + + + align:start position:0% +does +but you think maybe that would be + + align:start position:0% +but you think maybe that would be + + + align:start position:0% +but you think maybe that would be +helpful in this situation + + align:start position:0% +helpful in this situation + + + align:start position:0% +helpful in this situation +right yeah so actually if i decided to + + align:start position:0% +right yeah so actually if i decided to + + + align:start position:0% +right yeah so actually if i decided to +augment by sizes also i could do the + + align:start position:0% +augment by sizes also i could do the + + + align:start position:0% +augment by sizes also i could do the +exact same kind of sequence + + align:start position:0% +exact same kind of sequence + + + align:start position:0% +exact same kind of sequence +find at operation right and i could be + + align:start position:0% +find at operation right and i could be + + + align:start position:0% +find at operation right and i could be +able to look up + + align:start position:0% +able to look up + + + align:start position:0% +able to look up +the n minus k item right + + align:start position:0% +the n minus k item right + + + align:start position:0% +the n minus k item right +in here using the exact same function + + align:start position:0% +in here using the exact same function + + + align:start position:0% +in here using the exact same function +for subtree at that i had + + align:start position:0% +for subtree at that i had + + + align:start position:0% +for subtree at that i had +in the sequence avl tree stuff right so + + align:start position:0% +in the sequence avl tree stuff right so + + + align:start position:0% +in the sequence avl tree stuff right so +actually in clrs they don't even bother + + align:start position:0% +actually in clrs they don't even bother + + + align:start position:0% +actually in clrs they don't even bother +with sequence avl trees + + align:start position:0% +with sequence avl trees + + + align:start position:0% +with sequence avl trees +right they go straight to if i wanted + + align:start position:0% +right they go straight to if i wanted + + + align:start position:0% +right they go straight to if i wanted +this rank find functionality + + align:start position:0% +this rank find functionality + + + align:start position:0% +this rank find functionality +on a sorted order of things right + + align:start position:0% +on a sorted order of things right + + + align:start position:0% +on a sorted order of things right +then i could augment with subtree sizes + + align:start position:0% +then i could augment with subtree sizes + + + align:start position:0% +then i could augment with subtree sizes +right + + align:start position:0% +right + + + align:start position:0% +right +but it's actually a much more useful + + align:start position:0% +but it's actually a much more useful + + + align:start position:0% +but it's actually a much more useful +general property + + align:start position:0% +general property + + + align:start position:0% +general property +so we decided to present it to you in + + align:start position:0% +so we decided to present it to you in + + + align:start position:0% +so we decided to present it to you in +the in the context of sequence abs juice + + align:start position:0% +the in the context of sequence abs juice + + + align:start position:0% +the in the context of sequence abs juice +because then i can just + + align:start position:0% +because then i can just + + + align:start position:0% +because then i can just +basically reduce to it when i get to + + align:start position:0% +basically reduce to it when i get to + + + align:start position:0% +basically reduce to it when i get to +here okay so + + align:start position:0% +here okay so + + + align:start position:0% +here okay so +that's kind of a structure of the data + + align:start position:0% +that's kind of a structure of the data + + + align:start position:0% +that's kind of a structure of the data +structure that'll work on this problem + + align:start position:0% +structure that'll work on this problem + + + align:start position:0% +structure that'll work on this problem +i leave it to you as an exercise to + + align:start position:0% +i leave it to you as an exercise to + + + align:start position:0% +i leave it to you as an exercise to +implement all of these operations + + align:start position:0% +implement all of these operations + + + align:start position:0% +implement all of these operations +for yourself or take a look at the + + align:start position:0% +for yourself or take a look at the + + + align:start position:0% +for yourself or take a look at the +solutions the last one um + + align:start position:0% +solutions the last one um + + + align:start position:0% +solutions the last one um +is going to be put online the solution + + align:start position:0% +is going to be put online the solution + + + align:start position:0% +is going to be put online the solution +uh + + align:start position:0% +uh + + + align:start position:0% +uh +it's pretty complicated it's what's + + align:start position:0% +it's pretty complicated it's what's + + + align:start position:0% +it's pretty complicated it's what's +called you can think of the size + + align:start position:0% +called you can think of the size + + + align:start position:0% +called you can think of the size +augmentation finding rank as a one-sided + + align:start position:0% +augmentation finding rank as a one-sided + + + align:start position:0% +augmentation finding rank as a one-sided +range query + + align:start position:0% +range query + + + align:start position:0% +range query +it's basically how many things are to + + align:start position:0% +it's basically how many things are to + + + align:start position:0% +it's basically how many things are to +the right of this value + + align:start position:0% +the right of this value + + + align:start position:0% +the right of this value +right what the last problem does is + + align:start position:0% +right what the last problem does is + + + align:start position:0% +right what the last problem does is +walks you through a two-sided range + + align:start position:0% +walks you through a two-sided range + + + align:start position:0% +walks you through a two-sided range +query + + align:start position:0% +query + + + align:start position:0% +query +right where i want to know how many + + align:start position:0% +right where i want to know how many + + + align:start position:0% +right where i want to know how many +nodes are between these two values + + align:start position:0% +nodes are between these two values + + + align:start position:0% +nodes are between these two values +okay so it's a walk-through + + align:start position:0% +okay so it's a walk-through + + + align:start position:0% +okay so it's a walk-through +all right thanks guys \ No newline at end of file diff --git a/MxWZwTA_PHc.txt b/MxWZwTA_PHc.txt new file mode 100644 index 0000000000000000000000000000000000000000..c7cc16dae1c908eb95935d455bf4a2e7a7792cfd --- /dev/null +++ b/MxWZwTA_PHc.txt @@ -0,0 +1,365 @@ +LORNA GIBSON: So +really the way I + +set up the lectures +is I write out + +notes for myself of +what I want to cover, + +and the notes are +pretty detailed. + +And in the past I always +just had the notes for me. + +And even though they +were reasonably neat + +and I could read them, I didn't +hand them out to the students. + +But because I've turned my +fall course into an MITx course + +and I want to make the lecture +notes available for that, + +when I was doing that course for +MITx I made really nice notes. + +And a friend of +mine who lectures, + +I was asking her how she did it, +and she said she actually goes + +and measures the chalkboard, +and she measures the aspect + +ratio, how tall to +wide the chalkboard is. + +And then she sets up her notes +so that they're the same aspect + +ratio, and she plans +out exactly where + +she's going to put everything +on the board on her notes. + +And so I started doing that. + +And when I'm doing the lecture +I put it all on the board, + +and I find a lot +of students-- even + +though I hand the +notes out now-- they + +like to write their own notes. + +And I think it helps them +pay attention in class + +and helps them kind of +focus on the material. + +So another thing I do in +the lectures, when I first + +started lecturing and +for a long time I just + +focused on the engineering, +you know, on the equations, + +this is the derivation, +this is an example, + +this is how you use this. + +And it was all just about +kind of the engineering + +of whatever I was working on. + +And I found over +the last few years, + +actually in both courses, in the +fall one on mechanical behavior + +and in the spring course +on cellular solids, + +I look for more interesting +examples and stories, kind + +of stories about the +people who discovered + +some of the principles +that we talk about. + +I tell them stories about +engineering situations that + +came up and there was some +interesting thing happened. + +And the students love it. + +I mean, they really like having +the kind of hard core mechanics + +broken up with some +sort of stories. + +So I do that a lot more +now than I used to do. + +So probably most +lecturers have some kind + +of interesting example +or historical thing + +that I talk about. + +So for instance, when I +teach the fall course, + +the mechanical +behavior materials, + +one of the first things +we talk about is stress. + +So stress is a +force per unit area. + +If I take this piece a wood +and I pull on it like this + +I'm pulling on it with a +force that goes out like this. + +Stress is just that force +divided by that area. + +And the unit of stress in the +SI system is called the Pascal. + +And it's named +after Blaise Pascal + +who's a French mathematician. + +And a couple of years ago I +was in France for a conference + +and I was in a little town +called Clermont-Ferrand, + +which is in the +middle of France. + +It's a pretty little town. + +And I'm just walking +around one day + +kind of seeing the square +and the cathedral and all + +this stuff, and I +see there is sign, + +there's like Pascal +something or another. + +And this was apparently the +site of Blaise Pascal's house. + +And right next door +to it is Cafe Pascal. + +So of course, I have to take +a photograph of Cafe Pascal. + +And in this other course, when +we get to the bit about stress + +and I tell them +about the Pascal I + +show them the picture +of the Cafe Pascal. + +And the other amusing thing +that they kind of get a kick + +out of because of Boston, you +know how in Boston there's + +the Freedom Trail and +there's a red line + +goes around all these +historical sites + +all this colonial and +revolutionary stuff + +around Boston. + +It's kind of cool, all +the tourists to it. + +Well in Clermont-Ferrand +there's a Pascal Trail. + +And there's little +metal medallions + +of the portrait of Blaise +Pascal put in the sidewalk + +and you can walk +around Clermont-Ferrand + +doing the Pascal Trail. + +So I kind of keep an eye +out for stuff like that + +and I put that into +the course now, + +and I never used to +do that kind of stuff. + +I have a picture from +the Library of Congress, + +which I went to just +for fun a while ago. + +And one of the main buildings is +this old, beautiful historical + +building for the +Library of Congress. + +And they have a marble staircase +that goes up the middle. + +And the staircase has +all these little cherubs. + +And there's an +agriculture cherub + +and he's holding +a sheaf of wheat. + +And there's a wine +cherub and he's holding + +a little thing of grapes. + +Well, it turns out +there's a mechanics cherub + +and he's holding a gear. + +So at the end of +the first lecture + +I show them the mechanic's +cherub with the gear. + +So there's these +cute little things. + +So I just keep an eye out +for these cute little things. + +And last fall, this past +fall, one of the students + +came up at the end of the +first lecture and he said, + +I really like art. + +And he says, is there going +to be more art in the class? + +And I'm like, not usually. + +This has kind of exhausted +my art in mechanics. + +And I said, but I'll +keep an eye out. + +And through the term there +actually were different things + +that I saw that had to +do with mechanics and art + +I showed the class. + +So one of them was at the +Peabody Essex Museum this fall + +there's been and display of the +mobile sculptures of Alexander + +Calder. + +And they also made +these very large, + +I think they're called +stabile sculptures, as well. + +The big sail at MIT is +one of his sculptures. + +And these mobiles are +actually a really nice example + +of free body diagrams in +mechanics and balancing + +the forces. + +So anyway, I got a picture +of one of his mobiles + +and I went up to the exhibit. + +And when I was at +the exhibit I found + +that he did a degree in +mechanical engineering. + +He actually was a +mechanical engineer. + +And so the students +were very, very tickled + +by the sculpture, the fact +that he studied engineering. + +So anyway, I look out +for stuff like that. \ No newline at end of file diff --git a/O5Vh5nCMMmA.txt b/O5Vh5nCMMmA.txt new file mode 100644 index 0000000000000000000000000000000000000000..0068f13379c6ae7b9339734bee07532d2a75b351 --- /dev/null +++ b/O5Vh5nCMMmA.txt @@ -0,0 +1,75 @@ +JOEL SCHINDALL: Our grading +in the class is important, + +but it's done a +little bit differently + +from the way an ordinary +course is graded. + +In an ordinary course, there's +a specific body of material, + +and so you can grade +on proficiency. + +Can the student solve second +order differential equations? + +So you give them some second +order differential equations + +on a problem set, +and if they solve it, + +they get a good grade. + +And if they don't solve it, they +wouldn't get as good a grade. + +We're trying to teach a +way of thinking and being + +innovative so we give them +exercises and presentations, + +and then we grade them on the +passion of their engagement. + +Some of them have better +presentation skills + +than others. + +We're not looking at an +absolute mark, but we're saying, + +did you go outside the box? + +Did you try something new? + +Given where you were when +you came into this course, + +did you increase your skill set +effectively and energetically? + +And if you do, that's a +good grade in the course. + +And we actually give many-- +many students get good grades + +in a course like +this, because they've + +elected to take a course to +enhance their capabilities. + +And that deserves a good grade. + +The ones who don't +get as good a grade + +are the ones who simply +haven't participated as fully. \ No newline at end of file diff --git a/OOmZkNa72t4.txt b/OOmZkNa72t4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4384514fd5d07768ca11add4a90c5f7dc995e318 --- /dev/null +++ b/OOmZkNa72t4.txt @@ -0,0 +1,10963 @@ +align:start position:0% + +all right so welcome back well had a + + align:start position:0% +all right so welcome back well had a + + + align:start position:0% +all right so welcome back well had a +little bit of a break before I get into + + align:start position:0% +little bit of a break before I get into + + + align:start position:0% +little bit of a break before I get into +I go over my quick recap you've + + align:start position:0% +I go over my quick recap you've + + + align:start position:0% +I go over my quick recap you've +hopefully all seen the announcements + + align:start position:0% +hopefully all seen the announcements + + + align:start position:0% +hopefully all seen the announcements +that we're going to delay the due date + + align:start position:0% +that we're going to delay the due date + + + align:start position:0% +that we're going to delay the due date +of the next problem set until Tuesday + + align:start position:0% +of the next problem set until Tuesday + + + align:start position:0% +of the next problem set until Tuesday +that's in part because some of the + + align:start position:0% +that's in part because some of the + + + align:start position:0% +that's in part because some of the +material that appears on it is what + + align:start position:0% +material that appears on it is what + + + align:start position:0% +material that appears on it is what +we're going to talk about in today's + + align:start position:0% +we're going to talk about in today's + + + align:start position:0% +we're going to talk about in today's +lecture I want to make sure you've at + + align:start position:0% +lecture I want to make sure you've at + + + align:start position:0% +lecture I want to make sure you've at +least seen a lecture on all the topics + + align:start position:0% +least seen a lecture on all the topics + + + align:start position:0% +least seen a lecture on all the topics +before you try to do some of the + + align:start position:0% +before you try to do some of the + + + align:start position:0% +before you try to do some of the +problems on it in truth you could + + align:start position:0% +problems on it in truth you could + + + align:start position:0% +problems on it in truth you could +probably based on things I talked about + + align:start position:0% +probably based on things I talked about + + + align:start position:0% +probably based on things I talked about +in the previous lecture you could + + align:start position:0% +in the previous lecture you could + + + align:start position:0% +in the previous lecture you could +probably deduce a lot of what you need + + align:start position:0% +probably deduce a lot of what you need + + + align:start position:0% +probably deduce a lot of what you need +to do but still it's good to go over it + + align:start position:0% +to do but still it's good to go over it + + + align:start position:0% +to do but still it's good to go over it +a little bit more methodically and then + + align:start position:0% +a little bit more methodically and then + + + align:start position:0% +a little bit more methodically and then +the next problem set will be posted a + + align:start position:0% +the next problem set will be posted a + + + align:start position:0% +the next problem set will be posted a +week from right yeah I think we posted a + + align:start position:0% +week from right yeah I think we posted a + + + align:start position:0% +week from right yeah I think we posted a +week from today all right so let me just + + align:start position:0% +week from today all right so let me just + + + align:start position:0% +week from today all right so let me just +get back to what we're talking about + + align:start position:0% +get back to what we're talking about + + + align:start position:0% +get back to what we're talking about +last time so I began introducing some + + align:start position:0% +last time so I began introducing some + + + align:start position:0% +last time so I began introducing some +geometric concepts and some quantities + + align:start position:0% +geometric concepts and some quantities + + + align:start position:0% +geometric concepts and some quantities +that we use to describe matter we've + + align:start position:0% +that we use to describe matter we've + + + align:start position:0% +that we use to describe matter we've +done a lot of things so far that's + + align:start position:0% +done a lot of things so far that's + + + align:start position:0% +done a lot of things so far that's +appropriate for describing kind of the + + align:start position:0% +appropriate for describing kind of the + + + align:start position:0% +appropriate for describing kind of the +kinematics of particles but that's + + align:start position:0% +kinematics of particles but that's + + + align:start position:0% +kinematics of particles but that's +rather restrictive okay we want to talk + + align:start position:0% +rather restrictive okay we want to talk + + + align:start position:0% +rather restrictive okay we want to talk +about a broader class of things than + + align:start position:0% +about a broader class of things than + + + align:start position:0% +about a broader class of things than +that and I began by introducing + + align:start position:0% +that and I began by introducing + + + align:start position:0% +that and I began by introducing +something which is again fairly simple + + align:start position:0% +something which is again fairly simple + + + align:start position:0% +something which is again fairly simple +but it's a useful tool for getting to + + align:start position:0% +but it's a useful tool for getting to + + + align:start position:0% +but it's a useful tool for getting to +think about how we are going to + + align:start position:0% +think about how we are going to + + + align:start position:0% +think about how we are going to +mathematically categorize certain + + align:start position:0% +mathematically categorize certain + + + align:start position:0% +mathematically categorize certain +important types of matter per me well + + align:start position:0% +important types of matter per me well + + + align:start position:0% +important types of matter per me well +that puts in my notes away also pardon + + align:start position:0% +that puts in my notes away also pardon + + + align:start position:0% +that puts in my notes away also pardon +me I'm recovering from I caught a + + align:start position:0% +me I'm recovering from I caught a + + + align:start position:0% +me I'm recovering from I caught a +terrible cold or the long weekend and + + align:start position:0% +terrible cold or the long weekend and + + + align:start position:0% +terrible cold or the long weekend and +I'm coughing incessantly so I will be + + align:start position:0% +I'm coughing incessantly so I will be + + + align:start position:0% +I'm coughing incessantly so I will be +occasionally alright so I introduced + + align:start position:0% +occasionally alright so I introduced + + + align:start position:0% +occasionally alright so I introduced +this quantity called the number floor + + align:start position:0% +this quantity called the number floor + + + align:start position:0% +this quantity called the number floor +vector and that is given by imagine you + + align:start position:0% +vector and that is given by imagine you + + + align:start position:0% +vector and that is given by imagine you +have sort of it's its best thinking + + align:start position:0% +have sort of it's its best thinking + + + align:start position:0% +have sort of it's its best thinking +about this in the context of something + + align:start position:0% +about this in the context of something + + + align:start position:0% +about this in the context of something +like dust so you have some kind of + + align:start position:0% +like dust so you have some kind of + + + align:start position:0% +like dust so you have some kind of +non-interacting a little agglomeration + + align:start position:0% +non-interacting a little agglomeration + + + align:start position:0% +non-interacting a little agglomeration +of tiny particles and in the rest frame + + align:start position:0% +of tiny particles and in the rest frame + + + align:start position:0% +of tiny particles and in the rest frame +of an element of this dust so imagine + + align:start position:0% +of an element of this dust so imagine + + + align:start position:0% +of an element of this dust so imagine +you go into the I'm gonna define the + + align:start position:0% +you go into the I'm gonna define the + + + align:start position:0% +you go into the I'm gonna define the +restaurant of that ailment by saying + + align:start position:0% +restaurant of that ailment by saying + + + align:start position:0% +restaurant of that ailment by saying +you'll imagine you've got a cubic + + align:start position:0% +you'll imagine you've got a cubic + + + align:start position:0% +you'll imagine you've got a cubic +nanometer of it or something like that + + align:start position:0% +nanometer of it or something like that + + + align:start position:0% +nanometer of it or something like that +and you go into the frame where + + align:start position:0% +and you go into the frame where + + + align:start position:0% +and you go into the frame where +everything in that cubic nanometer is on + + align:start position:0% +everything in that cubic nanometer is on + + + align:start position:0% +everything in that cubic nanometer is on +average at rest + + align:start position:0% +average at rest + + + align:start position:0% +average at rest +we'll call n sub zero the rest density + + align:start position:0% +we'll call n sub zero the rest density + + + align:start position:0% +we'll call n sub zero the rest density +okay forgot to write that down + + align:start position:0% +okay forgot to write that down + + + align:start position:0% +okay forgot to write that down +[Applause] + + align:start position:0% + + + + align:start position:0% + +so that's the rest density the rest + + align:start position:0% +so that's the rest density the rest + + + align:start position:0% +so that's the rest density the rest +pardon me + + align:start position:0% +pardon me + + + align:start position:0% +pardon me +number density so I go into that rest + + align:start position:0% +number density so I go into that rest + + + align:start position:0% +number density so I go into that rest +frame that tells me how many little dust + + align:start position:0% +frame that tells me how many little dust + + + align:start position:0% +frame that tells me how many little dust +particles there are per cubic volume per + + align:start position:0% +particles there are per cubic volume per + + + align:start position:0% +particles there are per cubic volume per +element of volume multiplied that by the + + align:start position:0% +element of volume multiplied that by the + + + align:start position:0% +element of volume multiplied that by the +four vector that sumi the floor velocity + + align:start position:0% +four vector that sumi the floor velocity + + + align:start position:0% +four vector that sumi the floor velocity +describing that element we're gonna call + + align:start position:0% +describing that element we're gonna call + + + align:start position:0% +describing that element we're gonna call +that capital n so that's a vector that + + align:start position:0% +that capital n so that's a vector that + + + align:start position:0% +that capital n so that's a vector that +describes its it's its components + + align:start position:0% +describes its it's its components + + + align:start position:0% +describes its it's its components +describe the number density in some + + align:start position:0% +describe the number density in some + + + align:start position:0% +describe the number density in some +other frame of reference in any frame of + + align:start position:0% +other frame of reference in any frame of + + + align:start position:0% +other frame of reference in any frame of +reference and the flux tell me about how + + align:start position:0% +reference and the flux tell me about how + + + align:start position:0% +reference and the flux tell me about how +those dust particles flow from one + + align:start position:0% +those dust particles flow from one + + + align:start position:0% +those dust particles flow from one +element to another so we spent a little + + align:start position:0% +element to another so we spent a little + + + align:start position:0% +element to another so we spent a little +bit of time talking about how to define + + align:start position:0% +bit of time talking about how to define + + + align:start position:0% +bit of time talking about how to define +volume elements in a covariant fashion + + align:start position:0% +volume elements in a covariant fashion + + + align:start position:0% +volume elements in a covariant fashion +I'm not going to go through that but + + align:start position:0% +I'm not going to go through that but + + + align:start position:0% +I'm not going to go through that but +part of the punch line of doing that is + + align:start position:0% +part of the punch line of doing that is + + + align:start position:0% +part of the punch line of doing that is +that we're going to define a sort of + + align:start position:0% +that we're going to define a sort of + + + align:start position:0% +that we're going to define a sort of +eight what I call a covariant + + align:start position:0% +eight what I call a covariant + + + align:start position:0% +eight what I call a covariant +formulation of conservation of number is + + align:start position:0% +formulation of conservation of number is + + + align:start position:0% +formulation of conservation of number is +it's going to be the space-time + + align:start position:0% +it's going to be the space-time + + + align:start position:0% +it's going to be the space-time +divergence of that vector is equal to + + align:start position:0% +divergence of that vector is equal to + + + align:start position:0% +divergence of that vector is equal to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +okay that holds this equation holds in + + align:start position:0% +okay that holds this equation holds in + + + align:start position:0% +okay that holds this equation holds in +all frames of reference if I choose a + + align:start position:0% +all frames of reference if I choose a + + + align:start position:0% +all frames of reference if I choose a +particular frame of reference in other + + align:start position:0% +particular frame of reference in other + + + align:start position:0% +particular frame of reference in other +words I define a particular time i + + align:start position:0% +words I define a particular time i + + + align:start position:0% +words I define a particular time i +define a particular set of spatial + + align:start position:0% +define a particular set of spatial + + + align:start position:0% +define a particular set of spatial +coordinates I can then break this up and + + align:start position:0% +coordinates I can then break this up and + + + align:start position:0% +coordinates I can then break this up and +say that this is equivalent to saying + + align:start position:0% +say that this is equivalent to saying + + + align:start position:0% +say that this is equivalent to saying +that the time derivative of the T + + align:start position:0% +that the time derivative of the T + + + align:start position:0% +that the time derivative of the T +component of that plus the spatial + + align:start position:0% +component of that plus the spatial + + + align:start position:0% +component of that plus the spatial +divergence of the spatial comment so + + align:start position:0% +divergence of the spatial comment so + + + align:start position:0% +divergence of the spatial comment so +that they sum to zero I can also take + + align:start position:0% +that they sum to zero I can also take + + + align:start position:0% +that they sum to zero I can also take +this thing and integrate over eight + + align:start position:0% +this thing and integrate over eight + + + align:start position:0% +this thing and integrate over eight +loops would help to have one element to + + align:start position:0% +loops would help to have one element to + + + align:start position:0% +loops would help to have one element to +find here I integrate this over a four + + align:start position:0% +find here I integrate this over a four + + + align:start position:0% +find here I integrate this over a four +dimensional volume and by my + + align:start position:0% +dimensional volume and by my + + + align:start position:0% +dimensional volume and by my +conservation law I must get zero when I + + align:start position:0% +conservation law I must get zero when I + + + align:start position:0% +conservation law I must get zero when I +do that again having chosen a particular + + align:start position:0% +do that again having chosen a particular + + + align:start position:0% +do that again having chosen a particular +frame to find what time means to find + + align:start position:0% +frame to find what time means to find + + + align:start position:0% +frame to find what time means to find +what space means I can then split this + + align:start position:0% +what space means I can then split this + + + align:start position:0% +what space means I can then split this +out into a statement that the time + + align:start position:0% +out into a statement that the time + + + align:start position:0% +out into a statement that the time +derivative of the volume integral of + + align:start position:0% +derivative of the volume integral of + + + align:start position:0% +derivative of the volume integral of +that time component of this thing is + + align:start position:0% +that time component of this thing is + + + align:start position:0% +that time component of this thing is +balanced by the flux of the number + + align:start position:0% +balanced by the flux of the number + + + align:start position:0% +balanced by the flux of the number +across the boundaries of a particular + + align:start position:0% +across the boundaries of a particular + + + align:start position:0% +across the boundaries of a particular +three volume okay + + align:start position:0% +three volume okay + + + align:start position:0% +three volume okay +and I remind you this notation the sort + + align:start position:0% +and I remind you this notation the sort + + + align:start position:0% +and I remind you this notation the sort +of Delta V 3 means the boundaries of the + + align:start position:0% +of Delta V 3 means the boundaries of the + + + align:start position:0% +of Delta V 3 means the boundaries of the +v3 that's used under this integral ok so + + align:start position:0% +v3 that's used under this integral ok so + + + align:start position:0% +v3 that's used under this integral ok so +we talked a little bit about a few other + + align:start position:0% +we talked a little bit about a few other + + + align:start position:0% +we talked a little bit about a few other +four vectors that are used particular I + + align:start position:0% +four vectors that are used particular I + + + align:start position:0% +four vectors that are used particular I +introduced some stuff that we use in + + align:start position:0% +introduced some stuff that we use in + + + align:start position:0% +introduced some stuff that we use in +electricity and magnetism but I want to + + align:start position:0% +electricity and magnetism but I want to + + + align:start position:0% +electricity and magnetism but I want to +switch gears okay in particular I want + + align:start position:0% +switch gears okay in particular I want + + + align:start position:0% +switch gears okay in particular I want +to introduce and discuss in some detail + + align:start position:0% +to introduce and discuss in some detail + + + align:start position:0% +to introduce and discuss in some detail +one of the most important tensors we are + + align:start position:0% +one of the most important tensors we are + + + align:start position:0% +one of the most important tensors we are +going to use all term so I motivated + + align:start position:0% +going to use all term so I motivated + + + align:start position:0% +going to use all term so I motivated +this by saying imagine you know I have a + + align:start position:0% +this by saying imagine you know I have a + + + align:start position:0% +this by saying imagine you know I have a +cloud of dust and I won't recreate one + + align:start position:0% +cloud of dust and I won't recreate one + + + align:start position:0% +cloud of dust and I won't recreate one +because I'm getting home for a cold and + + align:start position:0% +because I'm getting home for a cold and + + + align:start position:0% +because I'm getting home for a cold and +I want to I don't want to breathe chalk + + align:start position:0% +I want to I don't want to breathe chalk + + + align:start position:0% +I want to I don't want to breathe chalk +dust so imagine I make a little cloud of + + align:start position:0% +dust so imagine I make a little cloud of + + + align:start position:0% +dust so imagine I make a little cloud of +these things here so far we've + + align:start position:0% +these things here so far we've + + + align:start position:0% +these things here so far we've +characterized this thing by just + + align:start position:0% +characterized this thing by just + + + align:start position:0% +characterized this thing by just +counting the number of dust particles + + align:start position:0% +counting the number of dust particles + + + align:start position:0% +counting the number of dust particles +that are in there but that's not they're + + align:start position:0% +that are in there but that's not they're + + + align:start position:0% +that are in there but that's not they're +all there is to it right that dust has + + align:start position:0% +all there is to it right that dust has + + + align:start position:0% +all there is to it right that dust has +other properties and so the next thing + + align:start position:0% +other properties and so the next thing + + + align:start position:0% +other properties and so the next thing +which I would like to do is let's + + align:start position:0% +which I would like to do is let's + + + align:start position:0% +which I would like to do is let's +consider the energy and the momentum of + + align:start position:0% +consider the energy and the momentum of + + + align:start position:0% +consider the energy and the momentum of +every particle of dust in that cloud ok + + align:start position:0% +every particle of dust in that cloud ok + + + align:start position:0% +every particle of dust in that cloud ok +so let's just imagine let's again we're + + align:start position:0% +so let's just imagine let's again we're + + + align:start position:0% +so let's just imagine let's again we're +going to start with something simple and + + align:start position:0% +going to start with something simple and + + + align:start position:0% +going to start with something simple and +then we'll kind of walk up from there to + + align:start position:0% +then we'll kind of walk up from there to + + + align:start position:0% +then we'll kind of walk up from there to +a more generic situation let's imagine + + align:start position:0% +a more generic situation let's imagine + + + align:start position:0% +a more generic situation let's imagine +that my cloud consists of particles that + + align:start position:0% +that my cloud consists of particles that + + + align:start position:0% +that my cloud consists of particles that +are all identical and each dust particle + + align:start position:0% +are all identical and each dust particle + + + align:start position:0% +are all identical and each dust particle +has the same rest mass + + align:start position:0% + + + + align:start position:0% + +so suppose this guy has a rest mass so + + align:start position:0% +so suppose this guy has a rest mass so + + + align:start position:0% +so suppose this guy has a rest mass so +one of the things which I might want to + + align:start position:0% +one of the things which I might want to + + + align:start position:0% +one of the things which I might want to +do is in addition to characterizing this + + align:start position:0% +do is in addition to characterizing this + + + align:start position:0% +do is in addition to characterizing this +dust by saying that the number density + + align:start position:0% +dust by saying that the number density + + + align:start position:0% +dust by saying that the number density +mean isn't the same that the number + + align:start position:0% +mean isn't the same that the number + + + align:start position:0% +mean isn't the same that the number +density in a particular frame is N or n + + align:start position:0% +density in a particular frame is N or n + + + align:start position:0% +density in a particular frame is N or n +0 let's go into the rest frame of this + + align:start position:0% +0 let's go into the rest frame of this + + + align:start position:0% +0 let's go into the rest frame of this +thing I might be interested in knowing + + align:start position:0% +thing I might be interested in knowing + + + align:start position:0% +thing I might be interested in knowing +about the rest energy density so I'm + + align:start position:0% +about the rest energy density so I'm + + + align:start position:0% +about the rest energy density so I'm +gonna denote the rest energy density by + + align:start position:0% +gonna denote the rest energy density by + + + align:start position:0% +gonna denote the rest energy density by +Rho sub 0 each particle has a rest + + align:start position:0% +Rho sub 0 each particle has a rest + + + align:start position:0% +Rho sub 0 each particle has a rest +energy of M remember C is equal to 1 so + + align:start position:0% +energy of M remember C is equal to 1 so + + + align:start position:0% +energy of M remember C is equal to 1 so +MC squared if you want to if you want to + + align:start position:0% +MC squared if you want to if you want to + + + align:start position:0% +MC squared if you want to if you want to +hold to the formula that we've all known + + align:start position:0% +hold to the formula that we've all known + + + align:start position:0% +hold to the formula that we've all known +and loved since we were babies so that's + + align:start position:0% +and loved since we were babies so that's + + + align:start position:0% +and loved since we were babies so that's +the rest energy and then how many if I + + align:start position:0% +the rest energy and then how many if I + + + align:start position:0% +the rest energy and then how many if I +want to get the rest energy density I + + align:start position:0% +want to get the rest energy density I + + + align:start position:0% +want to get the rest energy density I +count up the number in each volume are + + align:start position:0% +count up the number in each volume are + + + align:start position:0% +count up the number in each volume are +the number per unit volume so it's M + + align:start position:0% +the number per unit volume so it's M + + + align:start position:0% +the number per unit volume so it's M +times n 0 so that's the rest energy + + align:start position:0% +times n 0 so that's the rest energy + + + align:start position:0% +times n 0 so that's the rest energy +density of this thing + + align:start position:0% +density of this thing + + + align:start position:0% +density of this thing +great let's now ask okay so that's what + + align:start position:0% +great let's now ask okay so that's what + + + align:start position:0% +great let's now ask okay so that's what +it looks like in the rest frame of this + + align:start position:0% +it looks like in the rest frame of this + + + align:start position:0% +it looks like in the rest frame of this +of this dust element let's imagine that + + align:start position:0% +of this dust element let's imagine that + + + align:start position:0% +of this dust element let's imagine that +I now bop into a frame that is moving + + align:start position:0% +I now bop into a frame that is moving + + + align:start position:0% +I now bop into a frame that is moving +with some speed relative to this + + align:start position:0% +with some speed relative to this + + + align:start position:0% +with some speed relative to this +restaurant + + align:start position:0% + + + + align:start position:0% + +in this frame the energy density I'm not + + align:start position:0% +in this frame the energy density I'm not + + + align:start position:0% +in this frame the energy density I'm not +gonna say rest energy down so you cuz + + align:start position:0% +gonna say rest energy down so you cuz + + + align:start position:0% +gonna say rest energy down so you cuz +I'm no longer in the rest frame but the + + align:start position:0% +I'm no longer in the rest frame but the + + + align:start position:0% +I'm no longer in the rest frame but the +energy density in this frame which I + + align:start position:0% +energy density in this frame which I + + + align:start position:0% +energy density in this frame which I +will denote by row without the + + align:start position:0% +will denote by row without the + + + align:start position:0% +will denote by row without the +subscripts zero it's gonna be the energy + + align:start position:0% +subscripts zero it's gonna be the energy + + + align:start position:0% +subscripts zero it's gonna be the energy +of each particle + + align:start position:0% +of each particle + + + align:start position:0% +of each particle +so that's gamma times M and the volume + + align:start position:0% +so that's gamma times M and the volume + + + align:start position:0% +so that's gamma times M and the volume +is going to be length cancer it's going + + align:start position:0% +is going to be length cancer it's going + + + align:start position:0% +is going to be length cancer it's going +to be a little bit larger sorry the + + align:start position:0% +to be a little bit larger sorry the + + + align:start position:0% +to be a little bit larger sorry the +volume is smaller right so because of a + + align:start position:0% +volume is smaller right so because of a + + + align:start position:0% +volume is smaller right so because of a +length contraction and so this guy + + align:start position:0% +length contraction and so this guy + + + align:start position:0% +length contraction and so this guy +actually gets boosted up to gamma and + + align:start position:0% +actually gets boosted up to gamma and + + + align:start position:0% +actually gets boosted up to gamma and +zero so in this frame the energy density + + align:start position:0% +zero so in this frame the energy density + + + align:start position:0% +zero so in this frame the energy density +is larger than the rest energy the rest + + align:start position:0% +is larger than the rest energy the rest + + + align:start position:0% +is larger than the rest energy the rest +energy density with a gamma squared + + align:start position:0% +energy density with a gamma squared + + + align:start position:0% +energy density with a gamma squared +factor okay straightforward algebra but + + align:start position:0% +factor okay straightforward algebra but + + + align:start position:0% +factor okay straightforward algebra but +I want you to stop and think about what + + align:start position:0% +I want you to stop and think about what + + + align:start position:0% +I want you to stop and think about what +that's telling us if this row were a + + align:start position:0% +that's telling us if this row were a + + + align:start position:0% +that's telling us if this row were a +component of a four vector is there any + + align:start position:0% +component of a four vector is there any + + + align:start position:0% +component of a four vector is there any +way I could get a gamma squared out of + + align:start position:0% +way I could get a gamma squared out of + + + align:start position:0% +way I could get a gamma squared out of +this thing by bopping between reference + + align:start position:0% +this thing by bopping between reference + + + align:start position:0% +this thing by bopping between reference +frames no right when I do that it's + + align:start position:0% +frames no right when I do that it's + + + align:start position:0% +frames no right when I do that it's +linear in Lorentz transformation matrix + + align:start position:0% +linear in Lorentz transformation matrix + + + align:start position:0% +linear in Lorentz transformation matrix +there's no way with a linear + + align:start position:0% +there's no way with a linear + + + align:start position:0% +there's no way with a linear +transformation that I would pick up two + + align:start position:0% +transformation that I would pick up two + + + align:start position:0% +transformation that I would pick up two +powers of gamma this is not how a you + + align:start position:0% +powers of gamma this is not how a you + + + align:start position:0% +powers of gamma this is not how a you +guys are probably all used to from + + align:start position:0% +guys are probably all used to from + + + align:start position:0% +guys are probably all used to from +Newtonian physics of thinking of energy + + align:start position:0% +Newtonian physics of thinking of energy + + + align:start position:0% +Newtonian physics of thinking of energy +density as a scalar this is not a + + align:start position:0% +density as a scalar this is not a + + + align:start position:0% +density as a scalar this is not a +Lorentz scalar okay a scalar is the same + + align:start position:0% +Lorentz scalar okay a scalar is the same + + + align:start position:0% +Lorentz scalar okay a scalar is the same +in all frames reference so this is a + + align:start position:0% +in all frames reference so this is a + + + align:start position:0% +in all frames reference so this is a +different quantity + + align:start position:0% + + + + align:start position:0% + +so it's neither a for vector component + + align:start position:0% +so it's neither a for vector component + + + align:start position:0% +so it's neither a for vector component +nor scaler okay it's got two of those + + align:start position:0% +nor scaler okay it's got two of those + + + align:start position:0% +nor scaler okay it's got two of those +things so it's not going to surprise you + + align:start position:0% +things so it's not going to surprise you + + + align:start position:0% +things so it's not going to surprise you +that what's actually going on here is we + + align:start position:0% +that what's actually going on here is we + + + align:start position:0% +that what's actually going on here is we +are picking out what we've done here is + + align:start position:0% +are picking out what we've done here is + + + align:start position:0% +are picking out what we've done here is +we've picked out a particular component + + align:start position:0% +we've picked out a particular component + + + align:start position:0% +we've picked out a particular component +of a tensor let's think a little bit + + align:start position:0% +of a tensor let's think a little bit + + + align:start position:0% +of a tensor let's think a little bit +more methodically about what tensor that + + align:start position:0% +more methodically about what tensor that + + + align:start position:0% +more methodically about what tensor that +must be so when I originally wrote down + + align:start position:0% +must be so when I originally wrote down + + + align:start position:0% +must be so when I originally wrote down +my row zero here I sort of just argued + + align:start position:0% +my row zero here I sort of just argued + + + align:start position:0% +my row zero here I sort of just argued +on physical grounds that it is it's the + + align:start position:0% +on physical grounds that it is it's the + + + align:start position:0% +on physical grounds that it is it's the +energy of every particle times the + + align:start position:0% +energy of every particle times the + + + align:start position:0% +energy of every particle times the +number of particles per unit volume of + + align:start position:0% +number of particles per unit volume of + + + align:start position:0% +number of particles per unit volume of +that thing + + align:start position:0% +that thing + + + align:start position:0% +that thing +well the energy that I use in this thing + + align:start position:0% +well the energy that I use in this thing + + + align:start position:0% +well the energy that I use in this thing +doing it in both the rest frame and in + + align:start position:0% +doing it in both the rest frame and in + + + align:start position:0% +doing it in both the rest frame and in +the other frame those are the time like + + align:start position:0% +the other frame those are the time like + + + align:start position:0% +the other frame those are the time like +components a particular floor vector + + align:start position:0% +components a particular floor vector + + + align:start position:0% +components a particular floor vector +okay so we assembled row by combining + + align:start position:0% + + + + align:start position:0% + +energy which is the time like component + + align:start position:0% + + + + align:start position:0% + +of the for momentum + + align:start position:0% + + + + align:start position:0% + +with number density which is the time + + align:start position:0% +with number density which is the time + + + align:start position:0% +with number density which is the time +like component of the number vector that + + align:start position:0% +like component of the number vector that + + + align:start position:0% +like component of the number vector that +I just recap a few minutes ago so + + align:start position:0% +I just recap a few minutes ago so + + + align:start position:0% +I just recap a few minutes ago so +there's a two time light components of + + align:start position:0% +there's a two time light components of + + + align:start position:0% +there's a two time light components of +four vectors here so that Rho is + + align:start position:0% + + + + align:start position:0% + +something like well let's put it this + + align:start position:0% +something like well let's put it this + + + align:start position:0% +something like well let's put it this +way I can write this as PT NT which + + align:start position:0% +way I can write this as PT NT which + + + align:start position:0% +way I can write this as PT NT which +tells me that it belongs to a tensor so + + align:start position:0% +tells me that it belongs to a tensor so + + + align:start position:0% +tells me that it belongs to a tensor so +let's define this as sum TT of a tensor + + align:start position:0% +let's define this as sum TT of a tensor + + + align:start position:0% +let's define this as sum TT of a tensor +that I've not carefully introduced yet + + align:start position:0% +that I've not carefully introduced yet + + + align:start position:0% +that I've not carefully introduced yet +there is some underlying tensor that we + + align:start position:0% +there is some underlying tensor that we + + + align:start position:0% +there is some underlying tensor that we +have built by looking at the either just + + align:start position:0% +have built by looking at the either just + + + align:start position:0% +have built by looking at the either just +the berries names this we'll call it the + + align:start position:0% +the berries names this we'll call it the + + + align:start position:0% +the berries names this we'll call it the +tensor product of two different four + + align:start position:0% +tensor product of two different four + + + align:start position:0% +tensor product of two different four +vectors + + align:start position:0% + + + + align:start position:0% + +so if I write this in the kind of + + align:start position:0% +so if I write this in the kind of + + + align:start position:0% +so if I write this in the kind of +abstract tensor notation that I've used + + align:start position:0% +abstract tensor notation that I've used + + + align:start position:0% +abstract tensor notation that I've used +occasionally in some of your textbooks + + align:start position:0% +occasionally in some of your textbooks + + + align:start position:0% +occasionally in some of your textbooks +this will be written with a bold-faced + + align:start position:0% +this will be written with a bold-faced + + + align:start position:0% +this will be written with a bold-faced +capital T I will use a double over line + + align:start position:0% +capital T I will use a double over line + + + align:start position:0% +capital T I will use a double over line +for this we might say that this T is the + + align:start position:0% +for this we might say that this T is the + + + align:start position:0% +for this we might say that this T is the +tensor product of the number vector with + + align:start position:0% +tensor product of the number vector with + + + align:start position:0% +tensor product of the number vector with +the 4-momentum okay now the number + + align:start position:0% +the 4-momentum okay now the number + + + align:start position:0% +the 4-momentum okay now the number +vector is itself just and zero times the + + align:start position:0% +vector is itself just and zero times the + + + align:start position:0% +vector is itself just and zero times the +floor velocity and my momentum since all + + align:start position:0% +floor velocity and my momentum since all + + + align:start position:0% +floor velocity and my momentum since all +the particles I'm assuming are the same + + align:start position:0% +the particles I'm assuming are the same + + + align:start position:0% +the particles I'm assuming are the same +is just the rest mass times a four + + align:start position:0% +is just the rest mass times a four + + + align:start position:0% +is just the rest mass times a four +momentum this thing actually looks kind + + align:start position:0% +momentum this thing actually looks kind + + + align:start position:0% +momentum this thing actually looks kind +of like for velocity times a four + + align:start position:0% +of like for velocity times a four + + + align:start position:0% +of like for velocity times a four +velocity with a pre factor and that pre + + align:start position:0% +velocity with a pre factor and that pre + + + align:start position:0% +velocity with a pre factor and that pre +factor is nothing more than the rest + + align:start position:0% +factor is nothing more than the rest + + + align:start position:0% +factor is nothing more than the rest +density okay so another way to say this + + align:start position:0% +density okay so another way to say this + + + align:start position:0% +density okay so another way to say this +is that if I make my cloud of dust and I + + align:start position:0% +is that if I make my cloud of dust and I + + + align:start position:0% +is that if I make my cloud of dust and I +go in and I look at its every little + + align:start position:0% +go in and I look at its every little + + + align:start position:0% +go in and I look at its every little +element in it I take the rest energy + + align:start position:0% +element in it I take the rest energy + + + align:start position:0% +element in it I take the rest energy +density of every dense every element in + + align:start position:0% +density of every dense every element in + + + align:start position:0% +density of every dense every element in +that dust I construct the tensor that + + align:start position:0% +that dust I construct the tensor that + + + align:start position:0% +that dust I construct the tensor that +comes from making the tensor products of + + align:start position:0% +comes from making the tensor products of + + + align:start position:0% +comes from making the tensor products of +the four velocity that dust with itself + + align:start position:0% +the four velocity that dust with itself + + + align:start position:0% +the four velocity that dust with itself +that is what this geometric object is + + align:start position:0% +that is what this geometric object is + + + align:start position:0% +that is what this geometric object is +equal to if you want to write this in + + align:start position:0% +equal to if you want to write this in + + + align:start position:0% +equal to if you want to write this in +index notation which is how we will + + align:start position:0% +index notation which is how we will + + + align:start position:0% +index notation which is how we will +write it ninety-nine point eight percent + + align:start position:0% +write it ninety-nine point eight percent + + + align:start position:0% +write it ninety-nine point eight percent +of time we would say that component + + align:start position:0% +of time we would say that component + + + align:start position:0% +of time we would say that component +alpha beta of this quantity T is that + + align:start position:0% +alpha beta of this quantity T is that + + + align:start position:0% +alpha beta of this quantity T is that +rest density times you offer you better + + align:start position:0% + + + + align:start position:0% + +so this is in terms of the physics we're + + align:start position:0% +so this is in terms of the physics we're + + + align:start position:0% +so this is in terms of the physics we're +gonna do this term this is perhaps the + + align:start position:0% +gonna do this term this is perhaps the + + + align:start position:0% +gonna do this term this is perhaps the +most important quantity that we're going + + align:start position:0% +most important quantity that we're going + + + align:start position:0% +most important quantity that we're going +to talk about so it's worth + + align:start position:0% +to talk about so it's worth + + + align:start position:0% +to talk about so it's worth +understanding what this thing is really + + align:start position:0% +understanding what this thing is really + + + align:start position:0% +understanding what this thing is really +telling us so if I want to get these + + align:start position:0% +telling us so if I want to get these + + + align:start position:0% +telling us so if I want to get these +components the alpha-beta + + align:start position:0% +components the alpha-beta + + + align:start position:0% +components the alpha-beta +out of this thing from this sort of + + align:start position:0% +out of this thing from this sort of + + + align:start position:0% +out of this thing from this sort of +abstract notation of the tensor so I'll + + align:start position:0% +abstract notation of the tensor so I'll + + + align:start position:0% +abstract notation of the tensor so I'll +remind you that we can do this by taking + + align:start position:0% +remind you that we can do this by taking + + + align:start position:0% +remind you that we can do this by taking +the tensor and plugging into its slots + + align:start position:0% +the tensor and plugging into its slots + + + align:start position:0% +the tensor and plugging into its slots +the basis one forms which tell me + + align:start position:0% +the basis one forms which tell me + + + align:start position:0% +the basis one forms which tell me +something about basis one forms are + + align:start position:0% +something about basis one forms are + + + align:start position:0% +something about basis one forms are +really useful for sort of measuring + + align:start position:0% +really useful for sort of measuring + + + align:start position:0% +really useful for sort of measuring +fluxes across a but in a particular + + align:start position:0% +fluxes across a but in a particular + + + align:start position:0% +fluxes across a but in a particular +direction and in fact this quantity has + + align:start position:0% +direction and in fact this quantity has + + + align:start position:0% +direction and in fact this quantity has +the geometric interpretation think of + + align:start position:0% +the geometric interpretation think of + + + align:start position:0% +the geometric interpretation think of +this as the flux of momentum component + + align:start position:0% +this as the flux of momentum component + + + align:start position:0% +this as the flux of momentum component +alpha in the beta direction okay so if + + align:start position:0% +alpha in the beta direction okay so if + + + align:start position:0% +alpha in the beta direction okay so if +we look at this component by component + + align:start position:0% +we look at this component by component + + + align:start position:0% +we look at this component by component +it's worth doing that so let's do the TT + + align:start position:0% +it's worth doing that so let's do the TT + + + align:start position:0% +it's worth doing that so let's do the TT +or zero zero component okay this is the + + align:start position:0% +or zero zero component okay this is the + + + align:start position:0% +or zero zero component okay this is the +one we've already done this is just Rho + + align:start position:0% +one we've already done this is just Rho + + + align:start position:0% +one we've already done this is just Rho +0 UT UT just Rho in that thing according + + align:start position:0% +0 UT UT just Rho in that thing according + + + align:start position:0% +0 UT UT just Rho in that thing according +to the words I've written down here this + + align:start position:0% +to the words I've written down here this + + + align:start position:0% +to the words I've written down here this +is the flux of PT in the T direction ok + + align:start position:0% +is the flux of PT in the T direction ok + + + align:start position:0% +is the flux of PT in the T direction ok +so PT tells me about energy the flux of + + align:start position:0% +so PT tells me about energy the flux of + + + align:start position:0% +so PT tells me about energy the flux of +energy in the energy Direction refers to + + align:start position:0% +energy in the energy Direction refers to + + + align:start position:0% +energy in the energy Direction refers to +you know so here's my water flowing in + + align:start position:0% +you know so here's my water flowing in + + + align:start position:0% +you know so here's my water flowing in +the time like direction just sitting + + align:start position:0% +the time like direction just sitting + + + align:start position:0% +the time like direction just sitting +there apparently doing nothing but know + + align:start position:0% +there apparently doing nothing but know + + + align:start position:0% +there apparently doing nothing but know +it's moving through time this is energy + + align:start position:0% +it's moving through time this is energy + + + align:start position:0% +it's moving through time this is energy +flowing through time it's energy density + + align:start position:0% + + + + align:start position:0% + +all sort of locked up in stable + + align:start position:0% +all sort of locked up in stable + + + align:start position:0% +all sort of locked up in stable +equilibrium here but if somebody comes + + align:start position:0% +equilibrium here but if somebody comes + + + align:start position:0% +equilibrium here but if somebody comes +in someday with a nice cup of anti water + + align:start position:0% +in someday with a nice cup of anti water + + + align:start position:0% +in someday with a nice cup of anti water +and combines that we get to have all + + align:start position:0% +and combines that we get to have all + + + align:start position:0% +and combines that we get to have all +that energy released and we can enjoy + + align:start position:0% +that energy released and we can enjoy + + + align:start position:0% +that energy released and we can enjoy +that for a few femtoseconds before we + + align:start position:0% +that for a few femtoseconds before we + + + align:start position:0% +that for a few femtoseconds before we +evaporate let's look at the other + + align:start position:0% +evaporate let's look at the other + + + align:start position:0% +evaporate let's look at the other +components so t0 I okay you can take the + + align:start position:0% +components so t0 I okay you can take the + + + align:start position:0% +components so t0 I okay you can take the +definition and plug it in in terms of + + align:start position:0% +definition and plug it in in terms of + + + align:start position:0% +definition and plug it in in terms of +the confluence it's obviously u T times + + align:start position:0% +the confluence it's obviously u T times + + + align:start position:0% +the confluence it's obviously u T times +UI but still use the definition by words + + align:start position:0% +UI but still use the definition by words + + + align:start position:0% +UI but still use the definition by words +so this is the flux of P sub T in the X + + align:start position:0% +so this is the flux of P sub T in the X + + + align:start position:0% +so this is the flux of P sub T in the X +I Direction okay so this is talking + + align:start position:0% +I Direction okay so this is talking + + + align:start position:0% +I Direction okay so this is talking +about energy moving in a particular + + align:start position:0% +about energy moving in a particular + + + align:start position:0% +about energy moving in a particular +direction this is nothing more than + + align:start position:0% +direction this is nothing more than + + + align:start position:0% +direction this is nothing more than +energy flux okay energy sort of flux + + align:start position:0% +energy flux okay energy sort of flux + + + align:start position:0% +energy flux okay energy sort of flux +that we're used to think about not + + align:start position:0% +that we're used to think about not + + + align:start position:0% +that we're used to think about not +flowing through time but throwing + + align:start position:0% +flowing through time but throwing + + + align:start position:0% +flowing through time but throwing +through space now T 0 I this is the flux + + align:start position:0% +through space now T 0 I this is the flux + + + align:start position:0% +through space now T 0 I this is the flux +of momentum component I in the T + + align:start position:0% +of momentum component I in the T + + + align:start position:0% +of momentum component I in the T +direction so this tells me about + + align:start position:0% +direction so this tells me about + + + align:start position:0% +direction so this tells me about +momentum density okay so if I had this + + align:start position:0% +momentum density okay so if I had this + + + align:start position:0% +momentum density okay so if I had this +stuff flowing okay there's some momentum + + align:start position:0% +stuff flowing okay there's some momentum + + + align:start position:0% +stuff flowing okay there's some momentum +associate with that flow you can count + + align:start position:0% +associate with that flow you can count + + + align:start position:0% +associate with that flow you can count +up the amount of mass and every little + + align:start position:0% +up the amount of mass and every little + + + align:start position:0% +up the amount of mass and every little +volume divided by that volume take some + + align:start position:0% +volume divided by that volume take some + + + align:start position:0% +volume divided by that volume take some +ratios that is the density of momentum + + align:start position:0% + + + + align:start position:0% + +and finally this last one flux of P I in + + align:start position:0% +and finally this last one flux of P I in + + + align:start position:0% +and finally this last one flux of P I in +the X J direction she's really no great + + align:start position:0% +the X J direction she's really no great + + + align:start position:0% +the X J direction she's really no great +wisdom for that this is nothing more + + align:start position:0% +wisdom for that this is nothing more + + + align:start position:0% +wisdom for that this is nothing more +than momentum flux if I have a bucket of + + align:start position:0% +than momentum flux if I have a bucket of + + + align:start position:0% +than momentum flux if I have a bucket of +water and things are sort of sloshing + + align:start position:0% +water and things are sort of sloshing + + + align:start position:0% +water and things are sort of sloshing +around there's some momentum moving and + + align:start position:0% +around there's some momentum moving and + + + align:start position:0% +around there's some momentum moving and +the whole assembly is moving in some + + align:start position:0% +the whole assembly is moving in some + + + align:start position:0% +the whole assembly is moving in some +direction we can get a flow of momentum + + align:start position:0% +direction we can get a flow of momentum + + + align:start position:0% +direction we can get a flow of momentum +going in kind of a non normal direction + + align:start position:0% +going in kind of a non normal direction + + + align:start position:0% +going in kind of a non normal direction +sometimes it goes in a normal direction + + align:start position:0% +sometimes it goes in a normal direction + + + align:start position:0% +sometimes it goes in a normal direction +it might be moving along so it's flow + + align:start position:0% +it might be moving along so it's flow + + + align:start position:0% +it might be moving along so it's flow +I'm gonna talk about that in a few + + align:start position:0% +I'm gonna talk about that in a few + + + align:start position:0% +I'm gonna talk about that in a few +moments when I talk about a few + + align:start position:0% +moments when I talk about a few + + + align:start position:0% +moments when I talk about a few +different kinds of stress energy tensor + + align:start position:0% +different kinds of stress energy tensor + + + align:start position:0% +different kinds of stress energy tensor +x' the key thing which I want you to be + + align:start position:0% +x' the key thing which I want you to be + + + align:start position:0% +x' the key thing which I want you to be +aware of is that under the hood of this + + align:start position:0% +aware of is that under the hood of this + + + align:start position:0% +aware of is that under the hood of this +thing we're going to talk about + + align:start position:0% +thing we're going to talk about + + + align:start position:0% +thing we're going to talk about +different kinds of stress energy tensor + + align:start position:0% +different kinds of stress energy tensor + + + align:start position:0% +different kinds of stress energy tensor +x' for a little later in this class but + + align:start position:0% +x' for a little later in this class but + + + align:start position:0% +x' for a little later in this class but +this basic interpretation of the way to + + align:start position:0% +this basic interpretation of the way to + + + align:start position:0% +this basic interpretation of the way to +think about the different components it + + align:start position:0% +think about the different components it + + + align:start position:0% +think about the different components it +holds for all of them ok so this is good + + align:start position:0% +holds for all of them ok so this is good + + + align:start position:0% +holds for all of them ok so this is good +intuition to have one thing which is + + align:start position:0% +intuition to have one thing which is + + + align:start position:0% +intuition to have one thing which is +worth noting + + align:start position:0% + + + + align:start position:0% + +is you know if you look at if you + + align:start position:0% +is you know if you look at if you + + + align:start position:0% +is you know if you look at if you +actually let's take the form of the + + align:start position:0% +actually let's take the form of the + + + align:start position:0% +actually let's take the form of the +stress-energy tensor the corresponds to + + align:start position:0% +stress-energy tensor the corresponds to + + + align:start position:0% +stress-energy tensor the corresponds to +the dust okay so I'm gonna write out all + + align:start position:0% +the dust okay so I'm gonna write out all + + + align:start position:0% +the dust okay so I'm gonna write out all +four of my complex I've already given + + align:start position:0% +four of my complex I've already given + + + align:start position:0% +four of my complex I've already given +you t 0 0 t 0 I I can write that as + + align:start position:0% +you t 0 0 t 0 I I can write that as + + + align:start position:0% +you t 0 0 t 0 I I can write that as +gamma squared Rho 0 VI t 0 I equals + + align:start position:0% +gamma squared Rho 0 VI t 0 I equals + + + align:start position:0% +gamma squared Rho 0 VI t 0 I equals +gamma squared Rho 0 V I this guy is + + align:start position:0% +gamma squared Rho 0 V I this guy is + + + align:start position:0% +gamma squared Rho 0 V I this guy is +gamma squared Rho 0 VI VJ there's two + + align:start position:0% +gamma squared Rho 0 VI VJ there's two + + + align:start position:0% +gamma squared Rho 0 VI VJ there's two +elements of symmetry here which I want + + align:start position:0% +elements of symmetry here which I want + + + align:start position:0% +elements of symmetry here which I want +to emphasize notice energy density and + + align:start position:0% +to emphasize notice energy density and + + + align:start position:0% +to emphasize notice energy density and +momentum flux sorry energy flux and + + align:start position:0% +momentum flux sorry energy flux and + + + align:start position:0% +momentum flux sorry energy flux and +momentum density those words are + + align:start position:0% +momentum density those words are + + + align:start position:0% +momentum density those words are +important energy flux and momentum + + align:start position:0% +important energy flux and momentum + + + align:start position:0% +important energy flux and momentum +density they're exactly the same okay + + align:start position:0% +density they're exactly the same okay + + + align:start position:0% +density they're exactly the same okay +that is actually true in all physics + + align:start position:0% +that is actually true in all physics + + + align:start position:0% +that is actually true in all physics +okay it's clouded by the fact though + + align:start position:0% +okay it's clouded by the fact though + + + align:start position:0% +okay it's clouded by the fact though +that in most units that we measure + + align:start position:0% +that in most units that we measure + + + align:start position:0% +that in most units that we measure +things in we don't typically use speed + + align:start position:0% +things in we don't typically use speed + + + align:start position:0% +things in we don't typically use speed +of light equal to 1 so when you look at + + align:start position:0% +of light equal to 1 so when you look at + + + align:start position:0% +of light equal to 1 so when you look at +these kind of quantities in the physics + + align:start position:0% +these kind of quantities in the physics + + + align:start position:0% +these kind of quantities in the physics +that you are more used to you would find + + align:start position:0% +that you are more used to you would find + + + align:start position:0% +that you are more used to you would find +you know your energy your energy flux + + align:start position:0% +you know your energy your energy flux + + + align:start position:0% +you know your energy your energy flux +your momentum density will have + + align:start position:0% +your momentum density will have + + + align:start position:0% +your momentum density will have +different units okay cuz you'll have + + align:start position:0% +different units okay cuz you'll have + + + align:start position:0% +different units okay cuz you'll have +factors of C that come into there that + + align:start position:0% +factors of C that come into there that + + + align:start position:0% +factors of C that come into there that +convert from one momentum and energy and + + align:start position:0% +convert from one momentum and energy and + + + align:start position:0% +convert from one momentum and energy and +time flow and space flow also you don't + + align:start position:0% +time flow and space flow also you don't + + + align:start position:0% +time flow and space flow also you don't +usually include rest mass and rest + + align:start position:0% +usually include rest mass and rest + + + align:start position:0% +usually include rest mass and rest +energy and the energy flows and momentum + + align:start position:0% +energy and the energy flows and momentum + + + align:start position:0% +energy and the energy flows and momentum +densities that you've probably been + + align:start position:0% +densities that you've probably been + + + align:start position:0% +densities that you've probably been +familiar with in the past okay so it's + + align:start position:0% +familiar with in the past okay so it's + + + align:start position:0% +familiar with in the past okay so it's +when we do relativity and we set the + + align:start position:0% +when we do relativity and we set the + + + align:start position:0% +when we do relativity and we set the +speed of light equal to 1 that this + + align:start position:0% +speed of light equal to 1 that this + + + align:start position:0% +speed of light equal to 1 that this +symmetry between energy flux and + + align:start position:0% +symmetry between energy flux and + + + align:start position:0% +symmetry between energy flux and +momentum density becomes apparent + + align:start position:0% +momentum density becomes apparent + + + align:start position:0% +momentum density becomes apparent +question sorry this one yeah on the + + align:start position:0% +question sorry this one yeah on the + + + align:start position:0% +question sorry this one yeah on the +right hand side this is now this is this + + align:start position:0% +right hand side this is now this is this + + + align:start position:0% +right hand side this is now this is this +is definitely what I mean to write down + + align:start position:0% +is definitely what I mean to write down + + + align:start position:0% +is definitely what I mean to write down +here so this is what I've done I've + + align:start position:0% +here so this is what I've done I've + + + align:start position:0% +here so this is what I've done I've +taken advantage of the fact that I can + + align:start position:0% +taken advantage of the fact that I can + + + align:start position:0% +taken advantage of the fact that I can +write + + align:start position:0% + + + + align:start position:0% + +have it down somewhere yeah yeah so what + + align:start position:0% +have it down somewhere yeah yeah so what + + + align:start position:0% +have it down somewhere yeah yeah so what +I've done over here is I have written + + align:start position:0% +I've done over here is I have written + + + align:start position:0% +I've done over here is I have written +the fact so u sub T u T is it's just the + + align:start position:0% +the fact so u sub T u T is it's just the + + + align:start position:0% +the fact so u sub T u T is it's just the +gamma factor okay and I didn't + + align:start position:0% +gamma factor okay and I didn't + + + align:start position:0% +gamma factor okay and I didn't +explicitly write out what T the you know + + align:start position:0% +explicitly write out what T the you know + + + align:start position:0% +explicitly write out what T the you know +the the I complex but you get a similar + + align:start position:0% +the the I complex but you get a similar + + + align:start position:0% +the the I complex but you get a similar +factor that once that so know that that + + align:start position:0% +factor that once that so know that that + + + align:start position:0% +factor that once that so know that that +is correct that way yeah yeah + + align:start position:0% +is correct that way yeah yeah + + + align:start position:0% +is correct that way yeah yeah +a nice one emphasize I mean the key + + align:start position:0% +a nice one emphasize I mean the key + + + align:start position:0% +a nice one emphasize I mean the key +thing which I want to emphasize is when + + align:start position:0% +thing which I want to emphasize is when + + + align:start position:0% +thing which I want to emphasize is when +you do it in the physics that you guys + + align:start position:0% +you do it in the physics that you guys + + + align:start position:0% +you do it in the physics that you guys +have generally all seen up till now it + + align:start position:0% +have generally all seen up till now it + + + align:start position:0% +have generally all seen up till now it +won't look that way and that's to cause + + align:start position:0% +won't look that way and that's to cause + + + align:start position:0% +won't look that way and that's to cause +of that one is you're not used to + + align:start position:0% +of that one is you're not used to + + + align:start position:0% +of that one is you're not used to +necessarily working in units where the + + align:start position:0% +necessarily working in units where the + + + align:start position:0% +necessarily working in units where the +speed of light is one and two rest + + align:start position:0% +speed of light is one and two rest + + + align:start position:0% +speed of light is one and two rest +energy is built into these definitions + + align:start position:0% +energy is built into these definitions + + + align:start position:0% +energy is built into these definitions +that shift things a little bit the other + + align:start position:0% +that shift things a little bit the other + + + align:start position:0% +that shift things a little bit the other +thing which I want to emphasize is + + align:start position:0% +thing which I want to emphasize is + + + align:start position:0% +thing which I want to emphasize is +notice this is symmetric under exchange + + align:start position:0% +notice this is symmetric under exchange + + + align:start position:0% +notice this is symmetric under exchange +of indices okay you know it's obvious + + align:start position:0% +of indices okay you know it's obvious + + + align:start position:0% +of indices okay you know it's obvious +for dust it comes right back to the fact + + align:start position:0% +for dust it comes right back to the fact + + + align:start position:0% +for dust it comes right back to the fact +that these guys that those indices enter + + align:start position:0% +that these guys that those indices enter + + + align:start position:0% +that these guys that those indices enter +like so it's a exterior product the + + align:start position:0% +like so it's a exterior product the + + + align:start position:0% +like so it's a exterior product the +floor velocity with itself I'm not going + + align:start position:0% +floor velocity with itself I'm not going + + + align:start position:0% +floor velocity with itself I'm not going +to go through in detail but there is a + + align:start position:0% +to go through in detail but there is a + + + align:start position:0% +to go through in detail but there is a +physical motivation that I will sketch + + align:start position:0% +physical motivation that I will sketch + + + align:start position:0% +physical motivation that I will sketch +in a few moments that argues that it + + align:start position:0% +in a few moments that argues that it + + + align:start position:0% +in a few moments that argues that it +must be symmetric like this in all + + align:start position:0% +must be symmetric like this in all + + + align:start position:0% +must be symmetric like this in all +physical cases okay I have detailed a + + align:start position:0% +physical cases okay I have detailed a + + + align:start position:0% +physical cases okay I have detailed a +detailed sketch of this it's I keep + + align:start position:0% +detailed sketch of this it's I keep + + + align:start position:0% +detailed sketch of this it's I keep +using the word sketch because my mind + + align:start position:0% +using the word sketch because my mind + + + align:start position:0% +using the word sketch because my mind +wants to say proof but in a proof sort + + align:start position:0% +wants to say proof but in a proof sort + + + align:start position:0% +wants to say proof but in a proof sort +of a motivation and so I will post it + + align:start position:0% +of a motivation and so I will post it + + + align:start position:0% +of a motivation and so I will post it +for everyone to go through but I will + + align:start position:0% +for everyone to go through but I will + + + align:start position:0% +for everyone to go through but I will +sort of illuminate it in a couple + + align:start position:0% +sort of illuminate it in a couple + + + align:start position:0% +sort of illuminate it in a couple +moments basically if this is not true if + + align:start position:0% +moments basically if this is not true if + + + align:start position:0% +moments basically if this is not true if +it's not the case that's a symmetric a + + align:start position:0% +it's not the case that's a symmetric a + + + align:start position:0% +it's not the case that's a symmetric a +physical absurdity can be set up I'll + + align:start position:0% +physical absurdity can be set up I'll + + + align:start position:0% +physical absurdity can be set up I'll +describe that in a few moments so most + + align:start position:0% +describe that in a few moments so most + + + align:start position:0% +describe that in a few moments so most +of the world is not dust so this is a + + align:start position:0% +of the world is not dust so this is a + + + align:start position:0% +of the world is not dust so this is a +decent example for helping to understand + + align:start position:0% +decent example for helping to understand + + + align:start position:0% +decent example for helping to understand +things but we are going to want to do + + align:start position:0% +things but we are going to want to do + + + align:start position:0% +things but we are going to want to do +more complicated and interesting + + align:start position:0% +more complicated and interesting + + + align:start position:0% +more complicated and interesting +examples so for us the way that we are + + align:start position:0% +examples so for us the way that we are + + + align:start position:0% +examples so for us the way that we are +going to do this there is a fairly + + align:start position:0% +going to do this there is a fairly + + + align:start position:0% +going to do this there is a fairly +general recipe that one can imagine + + align:start position:0% +general recipe that one can imagine + + + align:start position:0% +general recipe that one can imagine +applying this I'm going to save it for a + + align:start position:0% +applying this I'm going to save it for a + + + align:start position:0% +applying this I'm going to save it for a +little later in the class it so it + + align:start position:0% +little later in the class it so it + + + align:start position:0% +little later in the class it so it +borrows some techniques from field + + align:start position:0% +borrows some techniques from field + + + align:start position:0% +borrows some techniques from field +theory basically if you can write down a + + align:start position:0% +theory basically if you can write down a + + + align:start position:0% +theory basically if you can write down a +Lagrangian density that describes the + + align:start position:0% +Lagrangian density that describes the + + + align:start position:0% +Lagrangian density that describes the +fifth system that you're under under + + align:start position:0% +fifth system that you're under under + + + align:start position:0% +fifth system that you're under under +study there's a particular particular + + align:start position:0% +study there's a particular particular + + + align:start position:0% +study there's a particular particular +variation you can do that stress energy + + align:start position:0% +variation you can do that stress energy + + + align:start position:0% +variation you can do that stress energy +tensor emerges from but for now the key + + align:start position:0% +tensor emerges from but for now the key + + + align:start position:0% +tensor emerges from but for now the key +thing which I want to sort of say is + + align:start position:0% +thing which I want to sort of say is + + + align:start position:0% +thing which I want to sort of say is +that we basically are going to deduce + + align:start position:0% +that we basically are going to deduce + + + align:start position:0% +that we basically are going to deduce +what the stress energy tensor looks like + + align:start position:0% + + + + align:start position:0% + +by essentially going into a particular + + align:start position:0% +by essentially going into a particular + + + align:start position:0% +by essentially going into a particular +frame we'll call it the rest frame is + + align:start position:0% +frame we'll call it the rest frame is + + + align:start position:0% +frame we'll call it the rest frame is +usually the rest frame of some element + + align:start position:0% +usually the rest frame of some element + + + align:start position:0% +usually the rest frame of some element +of the material being studied and + + align:start position:0% +of the material being studied and + + + align:start position:0% +of the material being studied and +thinking carefully about this physical + + align:start position:0% +thinking carefully about this physical + + + align:start position:0% +thinking carefully about this physical +definition of what the different + + align:start position:0% +definition of what the different + + + align:start position:0% +definition of what the different +components mean okay this is not the + + align:start position:0% +components mean okay this is not the + + + align:start position:0% +components mean okay this is not the +most rigorous way to do it but it's a + + align:start position:0% +most rigorous way to do it but it's a + + + align:start position:0% +most rigorous way to do it but it's a +good way to get started and to develop + + align:start position:0% +good way to get started and to develop + + + align:start position:0% +good way to get started and to develop +some intuition + + align:start position:0% + + + + align:start position:0% + +okay so let me give one example that for + + align:start position:0% +okay so let me give one example that for + + + align:start position:0% +okay so let me give one example that for +many of us in astrophysics this is + + align:start position:0% +many of us in astrophysics this is + + + align:start position:0% +many of us in astrophysics this is +probably the one stress energy tensor + + align:start position:0% +probably the one stress energy tensor + + + align:start position:0% +probably the one stress energy tensor +that we write down and use over and over + + align:start position:0% +that we write down and use over and over + + + align:start position:0% +that we write down and use over and over +and over again in our career and it's + + align:start position:0% +and over again in our career and it's + + + align:start position:0% +and over again in our career and it's +rarely to anything more than this in + + align:start position:0% +rarely to anything more than this in + + + align:start position:0% +rarely to anything more than this in +many many cases this is called a perfect + + align:start position:0% +many many cases this is called a perfect + + + align:start position:0% +many many cases this is called a perfect +fluid so what is perfect about a perfect + + align:start position:0% +fluid so what is perfect about a perfect + + + align:start position:0% +fluid so what is perfect about a perfect +fluid let's beg the question here what + + align:start position:0% +fluid let's beg the question here what + + + align:start position:0% +fluid let's beg the question here what +is what is perfect referring to here so + + align:start position:0% +is what is perfect referring to here so + + + align:start position:0% +is what is perfect referring to here so +a perfect fluid is a fluid in which + + align:start position:0% +a perfect fluid is a fluid in which + + + align:start position:0% +a perfect fluid is a fluid in which +there is no energy flow in what I will + + align:start position:0% +there is no energy flow in what I will + + + align:start position:0% +there is no energy flow in what I will +call the rest frame + + align:start position:0% +call the rest frame + + + align:start position:0% +call the rest frame +I put rest in quotes because you have to + + align:start position:0% +I put rest in quotes because you have to + + + align:start position:0% +I put rest in quotes because you have to +sort of define it from the context of of + + align:start position:0% +sort of define it from the context of of + + + align:start position:0% +sort of define it from the context of of +what your fluid is there basically what + + align:start position:0% +what your fluid is there basically what + + + align:start position:0% +what your fluid is there basically what +it means I can find a frame in which + + align:start position:0% +it means I can find a frame in which + + + align:start position:0% +it means I can find a frame in which +each fluid element there is no energy + + align:start position:0% +each fluid element there is no energy + + + align:start position:0% +each fluid element there is no energy +flow there if a frame exists where that + + align:start position:0% +flow there if a frame exists where that + + + align:start position:0% +flow there if a frame exists where that +happens this is a candidate to be a + + align:start position:0% +happens this is a candidate to be a + + + align:start position:0% +happens this is a candidate to be a +perfect fluid and I also require there + + align:start position:0% +perfect fluid and I also require there + + + align:start position:0% +perfect fluid and I also require there +to be no lateral stresses lateral + + align:start position:0% +to be no lateral stresses lateral + + + align:start position:0% +to be no lateral stresses lateral +stresses refer to this tij when I and J + + align:start position:0% +stresses refer to this tij when I and J + + + align:start position:0% +stresses refer to this tij when I and J +are not equal to one an hour okay so + + align:start position:0% +are not equal to one an hour okay so + + + align:start position:0% +are not equal to one an hour okay so +this sort of refers to imagine that I + + align:start position:0% +this sort of refers to imagine that I + + + align:start position:0% +this sort of refers to imagine that I +have some let's say the going into the + + align:start position:0% +have some let's say the going into the + + + align:start position:0% +have some let's say the going into the +board is the Y direction so if there's + + align:start position:0% +board is the Y direction so if there's + + + align:start position:0% +board is the Y direction so if there's +like some Y stress that is somehow being + + align:start position:0% +like some Y stress that is somehow being + + + align:start position:0% +like some Y stress that is somehow being +transported in the X direction that + + align:start position:0% +transported in the X direction that + + + align:start position:0% +transported in the X direction that +would be a lateral stress physically + + align:start position:0% +would be a lateral stress physically + + + align:start position:0% +would be a lateral stress physically +this is actually that kind of a stress + + align:start position:0% +this is actually that kind of a stress + + + align:start position:0% +this is actually that kind of a stress +is hugely important when one of studying + + align:start position:0% +is hugely important when one of studying + + + align:start position:0% +is hugely important when one of studying +fluids okay and one characterizes it by + + align:start position:0% +fluids okay and one characterizes it by + + + align:start position:0% +fluids okay and one characterizes it by +a quantity known as the viscosity okay + + align:start position:0% +a quantity known as the viscosity okay + + + align:start position:0% +a quantity known as the viscosity okay +this cost he tells me about how stress + + align:start position:0% +this cost he tells me about how stress + + + align:start position:0% +this cost he tells me about how stress +gets transported how momentum rather + + align:start position:0% +gets transported how momentum rather + + + align:start position:0% +gets transported how momentum rather +gets transported in a non + + align:start position:0% +gets transported in a non + + + align:start position:0% +gets transported in a non +normal direction against the direction + + align:start position:0% +normal direction against the direction + + + align:start position:0% +normal direction against the direction +in which the fluid is moving so my + + align:start position:0% +in which the fluid is moving so my + + + align:start position:0% +in which the fluid is moving so my +perfect fluid has no viscosity and I'll + + align:start position:0% +perfect fluid has no viscosity and I'll + + + align:start position:0% +perfect fluid has no viscosity and I'll +just conclude you want to make a there's + + align:start position:0% +just conclude you want to make a there's + + + align:start position:0% +just conclude you want to make a there's +a very important point here a fluid that + + align:start position:0% +a very important point here a fluid that + + + align:start position:0% +a very important point here a fluid that +has no viscosity there's a fluid that + + align:start position:0% +has no viscosity there's a fluid that + + + align:start position:0% +has no viscosity there's a fluid that +doesn't get anything wet okay so this + + align:start position:0% +doesn't get anything wet okay so this + + + align:start position:0% +doesn't get anything wet okay so this +refers to when you pour water on + + align:start position:0% +refers to when you pour water on + + + align:start position:0% +refers to when you pour water on +yourself the reason your hand gets wet + + align:start position:0% +yourself the reason your hand gets wet + + + align:start position:0% +yourself the reason your hand gets wet +is that there's some viscosity that + + align:start position:0% +is that there's some viscosity that + + + align:start position:0% +is that there's some viscosity that +actually prevents it causes there to be + + align:start position:0% +actually prevents it causes there to be + + + align:start position:0% +actually prevents it causes there to be +sort of a shearing force which causes + + align:start position:0% +sort of a shearing force which causes + + + align:start position:0% +sort of a shearing force which causes +the water to stick to your skin so a + + align:start position:0% +the water to stick to your skin so a + + + align:start position:0% +the water to stick to your skin so a +perfect fluid this has been described as + + align:start position:0% +perfect fluid this has been described as + + + align:start position:0% +perfect fluid this has been described as +the physics of dry water okay so it is + + align:start position:0% +the physics of dry water okay so it is + + + align:start position:0% +the physics of dry water okay so it is +anyone who's in an applied math will + + align:start position:0% +anyone who's in an applied math will + + + align:start position:0% +anyone who's in an applied math will +know they'll sort of roll their eyes and + + align:start position:0% +know they'll sort of roll their eyes and + + + align:start position:0% +know they'll sort of roll their eyes and +say okay fine we'll do this sort of + + align:start position:0% +say okay fine we'll do this sort of + + + align:start position:0% +say okay fine we'll do this sort of +infant version of fluid first and then a + + align:start position:0% +infant version of fluid first and then a + + + align:start position:0% +infant version of fluid first and then a +lot of the action and a lot of the fun + + align:start position:0% +lot of the action and a lot of the fun + + + align:start position:0% +lot of the action and a lot of the fun +comes from putting in viscosity and + + align:start position:0% +comes from putting in viscosity and + + + align:start position:0% +comes from putting in viscosity and +doing the real fluids for the purposes + + align:start position:0% +doing the real fluids for the purposes + + + align:start position:0% +doing the real fluids for the purposes +of our class what this boils down to is + + align:start position:0% +of our class what this boils down to is + + + align:start position:0% +of our class what this boils down to is +this tells me that the physics of this + + align:start position:0% +this tells me that the physics of this + + + align:start position:0% +this tells me that the physics of this +quantity is totally dominated by the + + align:start position:0% +quantity is totally dominated by the + + + align:start position:0% +quantity is totally dominated by the +fluids energy density and it's pressure + + align:start position:0% + + + + align:start position:0% + +the pressure is an isotropic spatial + + align:start position:0% +the pressure is an isotropic spatial + + + align:start position:0% +the pressure is an isotropic spatial +stress so in this particular frame where + + align:start position:0% +stress so in this particular frame where + + + align:start position:0% +stress so in this particular frame where +I have no energy being transported + + align:start position:0% + + + + align:start position:0% + +then the stress-energy tensor can be + + align:start position:0% +then the stress-energy tensor can be + + + align:start position:0% +then the stress-energy tensor can be +represented as energy density as usual + + align:start position:0% +represented as energy density as usual + + + align:start position:0% +represented as energy density as usual +up in the over there now up in the titi + + align:start position:0% +up in the over there now up in the titi + + + align:start position:0% +up in the over there now up in the titi +component there is no energy flux by + + align:start position:0% +component there is no energy flux by + + + align:start position:0% +component there is no energy flux by +symmetry if there's no energy flux there + + align:start position:0% +symmetry if there's no energy flux there + + + align:start position:0% +symmetry if there's no energy flux there +is no momentum density and my spatial + + align:start position:0% +is no momentum density and my spatial + + + align:start position:0% +is no momentum density and my spatial +stresses are totally isotropic and none + + align:start position:0% +stresses are totally isotropic and none + + + align:start position:0% +stresses are totally isotropic and none +of them are lateral so it just looks + + align:start position:0% +of them are lateral so it just looks + + + align:start position:0% +of them are lateral so it just looks +like this at the diagonal of Rho okay as + + align:start position:0% +like this at the diagonal of Rho okay as + + + align:start position:0% +like this at the diagonal of Rho okay as +I said this is actually something that + + align:start position:0% +I said this is actually something that + + + align:start position:0% +I said this is actually something that +we're gonna use over and over and over + + align:start position:0% +we're gonna use over and over and over + + + align:start position:0% +we're gonna use over and over and over +again this is actually eight and so you + + align:start position:0% +again this is actually eight and so you + + + align:start position:0% +again this is actually eight and so you +can actually consider my Duff stress + + align:start position:0% +can actually consider my Duff stress + + + align:start position:0% +can actually consider my Duff stress +energy tensor to be a perfect fluid with + + align:start position:0% +energy tensor to be a perfect fluid with + + + align:start position:0% +energy tensor to be a perfect fluid with +no pressure okay so this actually + + align:start position:0% +no pressure okay so this actually + + + align:start position:0% +no pressure okay so this actually +subsumes this this other one I will just + + align:start position:0% +subsumes this this other one I will just + + + align:start position:0% +subsumes this this other one I will just +for the lust rate of purposes I'll show + + align:start position:0% +for the lust rate of purposes I'll show + + + align:start position:0% +for the lust rate of purposes I'll show +an example of a case that cannot be + + align:start position:0% +an example of a case that cannot be + + + align:start position:0% +an example of a case that cannot be +thought of as a as a perfect fluid but + + align:start position:0% +thought of as a as a perfect fluid but + + + align:start position:0% +thought of as a as a perfect fluid but +we will tend to use this a lot in our + + align:start position:0% +we will tend to use this a lot in our + + + align:start position:0% +we will tend to use this a lot in our +class and as I will demonstrate in just + + align:start position:0% +class and as I will demonstrate in just + + + align:start position:0% +class and as I will demonstrate in just +a moment we're going to find that this + + align:start position:0% +a moment we're going to find that this + + + align:start position:0% +a moment we're going to find that this +ends up playing an important role in + + align:start position:0% +ends up playing an important role in + + + align:start position:0% +ends up playing an important role in +generating gravitational fields and + + align:start position:0% +generating gravitational fields and + + + align:start position:0% +generating gravitational fields and +what's interesting about this is you + + align:start position:0% +what's interesting about this is you + + + align:start position:0% +what's interesting about this is you +guys would probably use the idea that + + align:start position:0% +guys would probably use the idea that + + + align:start position:0% +guys would probably use the idea that +mass generates gravity and then throw in + + align:start position:0% +mass generates gravity and then throw in + + + align:start position:0% +mass generates gravity and then throw in +a c square that tells you energy is + + align:start position:0% +a c square that tells you energy is + + + align:start position:0% +a c square that tells you energy is +generating gravity that's also we're + + align:start position:0% +generating gravity that's also we're + + + align:start position:0% +generating gravity that's also we're +gonna see pressure generates gravity + + align:start position:0% +gonna see pressure generates gravity + + + align:start position:0% +gonna see pressure generates gravity +okay and it's connected to the + + align:start position:0% +okay and it's connected to the + + + align:start position:0% +okay and it's connected to the +mathematical structure of this guy here + + align:start position:0% +mathematical structure of this guy here + + + align:start position:0% +mathematical structure of this guy here +so notice I've written an equal dot here + + align:start position:0% +so notice I've written an equal dot here + + + align:start position:0% +so notice I've written an equal dot here +okay so this is just the way this is + + align:start position:0% +okay so this is just the way this is + + + align:start position:0% +okay so this is just the way this is +represented in this particular frame I + + align:start position:0% +represented in this particular frame I + + + align:start position:0% +represented in this particular frame I +would like to write this in a more + + align:start position:0% +would like to write this in a more + + + align:start position:0% +would like to write this in a more +covariant form something that does not + + align:start position:0% +covariant form something that does not + + + align:start position:0% +covariant form something that does not +rely on me going into a particular frame + + align:start position:0% +rely on me going into a particular frame + + + align:start position:0% +rely on me going into a particular frame +of reference + + align:start position:0% + + + + align:start position:0% + +so the trick which I'm going to use for + + align:start position:0% +so the trick which I'm going to use for + + + align:start position:0% +so the trick which I'm going to use for +this is that I think about that form + + align:start position:0% +this is that I think about that form + + + align:start position:0% +this is that I think about that form +there so the row piece of it clearly + + align:start position:0% +there so the row piece of it clearly + + + align:start position:0% +there so the row piece of it clearly +what I'm doing there is I'm picking out + + align:start position:0% +what I'm doing there is I'm picking out + + + align:start position:0% +what I'm doing there is I'm picking out +you know that is can be thought of as + + align:start position:0% +you know that is can be thought of as + + + align:start position:0% +you know that is can be thought of as +the energy density multiplied by the + + align:start position:0% +the energy density multiplied by the + + + align:start position:0% +the energy density multiplied by the +tensor product of the four velocity it + + align:start position:0% +tensor product of the four velocity it + + + align:start position:0% +tensor product of the four velocity it +describes a particular element of this + + align:start position:0% +describes a particular element of this + + + align:start position:0% +describes a particular element of this +fluid so I can write again using this + + align:start position:0% +fluid so I can write again using this + + + align:start position:0% +fluid so I can write again using this +sort of abstract notation this piece of + + align:start position:0% +sort of abstract notation this piece of + + + align:start position:0% +sort of abstract notation this piece of +it looks like this okay and so if I go + + align:start position:0% +it looks like this okay and so if I go + + + align:start position:0% +it looks like this okay and so if I go +into the frame if I go into the rest + + align:start position:0% +into the frame if I go into the rest + + + align:start position:0% +into the frame if I go into the rest +frame of the fluid that's just you know + + align:start position:0% +frame of the fluid that's just you know + + + align:start position:0% +frame of the fluid that's just you know +my U is one and zeros and the spatial + + align:start position:0% +my U is one and zeros and the spatial + + + align:start position:0% +my U is one and zeros and the spatial +components that builds my upper + + align:start position:0% +components that builds my upper + + + align:start position:0% +components that builds my upper +left-hand corner of this tensor how do I + + align:start position:0% +left-hand corner of this tensor how do I + + + align:start position:0% +left-hand corner of this tensor how do I +get the rest of this well to get the + + align:start position:0% +get the rest of this well to get the + + + align:start position:0% +get the rest of this well to get the +rest of it these are all sort of picked + + align:start position:0% +rest of it these are all sort of picked + + + align:start position:0% +rest of it these are all sort of picked +out of compliant to the tensors that are + + align:start position:0% +out of compliant to the tensors that are + + + align:start position:0% +out of compliant to the tensors that are +orthogonal to you and I put an Easter + + align:start position:0% +orthogonal to you and I put an Easter + + + align:start position:0% +orthogonal to you and I put an Easter +egg and pset1 + + align:start position:0% +egg and pset1 + + + align:start position:0% +egg and pset1 +okay you guys developed a tensor that + + align:start position:0% +okay you guys developed a tensor that + + + align:start position:0% +okay you guys developed a tensor that +allows me to build it's a geometric + + align:start position:0% +allows me to build it's a geometric + + + align:start position:0% +allows me to build it's a geometric +object that allows me to describe things + + align:start position:0% +object that allows me to describe things + + + align:start position:0% +object that allows me to describe things +that are orthogonal to a given floor + + align:start position:0% +that are orthogonal to a given floor + + + align:start position:0% +that are orthogonal to a given floor +vector so if I take the projection + + align:start position:0% +vector so if I take the projection + + + align:start position:0% +vector so if I take the projection +tensor that you guys built on pset 1 + + align:start position:0% +tensor that you guys built on pset 1 + + + align:start position:0% +tensor that you guys built on pset 1 +which looks like the metric plus the + + align:start position:0% +which looks like the metric plus the + + + align:start position:0% +which looks like the metric plus the +extra the out the tensor product of a + + align:start position:0% +extra the out the tensor product of a + + + align:start position:0% +extra the out the tensor product of a +four vector with itself that gives me + + align:start position:0% +four vector with itself that gives me + + + align:start position:0% +four vector with itself that gives me +the peas that go into that component + + align:start position:0% +the peas that go into that component + + + align:start position:0% +the peas that go into that component +okay or if I write this in index + + align:start position:0% +okay or if I write this in index + + + align:start position:0% +okay or if I write this in index +notation I can do it in two ways + + align:start position:0% + + + + align:start position:0% + +I will also emphasize that there are a + + align:start position:0% +I will also emphasize that there are a + + + align:start position:0% +I will also emphasize that there are a +few moments in this class where I sort + + align:start position:0% +few moments in this class where I sort + + + align:start position:0% +few moments in this class where I sort +of urge you to take the sort of long + + align:start position:0% +of urge you to take the sort of long + + + align:start position:0% +of urge you to take the sort of long +term memory synapses and switch them on + + align:start position:0% +term memory synapses and switch them on + + + align:start position:0% +term memory synapses and switch them on +this is one of those moments in a couple + + align:start position:0% +this is one of those moments in a couple + + + align:start position:0% +this is one of those moments in a couple +of lectures we're gonna introduce the + + align:start position:0% +of lectures we're gonna introduce the + + + align:start position:0% +of lectures we're gonna introduce the +principle of equivalence which is the + + align:start position:0% +principle of equivalence which is the + + + align:start position:0% +principle of equivalence which is the +physical principle by which we're going + + align:start position:0% +physical principle by which we're going + + + align:start position:0% +physical principle by which we're going +to argue how we go from formulas that + + align:start position:0% +to argue how we go from formulas that + + + align:start position:0% +to argue how we go from formulas that +work in special relativity to formulas + + align:start position:0% +work in special relativity to formulas + + + align:start position:0% +work in special relativity to formulas +that work in general relativity and by + + align:start position:0% +that work in general relativity and by + + + align:start position:0% +that work in general relativity and by +invoking the principle of equivalence + + align:start position:0% +invoking the principle of equivalence + + + align:start position:0% +invoking the principle of equivalence +we're going to see that when we want to + + align:start position:0% +we're going to see that when we want to + + + align:start position:0% +we're going to see that when we want to +describe perfect fluids in a general + + align:start position:0% +describe perfect fluids in a general + + + align:start position:0% +describe perfect fluids in a general +space-time not just in special + + align:start position:0% +space-time not just in special + + + align:start position:0% +space-time not just in special +relativity of in general and general + + align:start position:0% +relativity of in general and general + + + align:start position:0% +relativity of in general and general +relativity it's exactly this formula I + + align:start position:0% +relativity it's exactly this formula I + + + align:start position:0% +relativity it's exactly this formula I +just need to modify what the metric + + align:start position:0% +just need to modify what the metric + + + align:start position:0% +just need to modify what the metric +means okay but that will allow me to + + align:start position:0% +means okay but that will allow me to + + + align:start position:0% +means okay but that will allow me to +carry that over ah let me see + + align:start position:0% +carry that over ah let me see + + + align:start position:0% +carry that over ah let me see +so my notes are a little bit + + align:start position:0% +so my notes are a little bit + + + align:start position:0% +so my notes are a little bit +disorganized here this is a piece that I + + align:start position:0% +disorganized here this is a piece that I + + + align:start position:0% +disorganized here this is a piece that I +every year I want to clean this bit up + + align:start position:0% +every year I want to clean this bit up + + + align:start position:0% +every year I want to clean this bit up +and every year at this time of year I + + align:start position:0% +and every year at this time of year I + + + align:start position:0% +and every year at this time of year I +have 70 gazillion administrative tasks + + align:start position:0% +have 70 gazillion administrative tasks + + + align:start position:0% +have 70 gazillion administrative tasks +and getting behind schedule so I will + + align:start position:0% +and getting behind schedule so I will + + + align:start position:0% +and getting behind schedule so I will +clean this up on the fly so there's a + + align:start position:0% +clean this up on the fly so there's a + + + align:start position:0% +clean this up on the fly so there's a +couple points which I want to make about + + align:start position:0% +couple points which I want to make about + + + align:start position:0% +couple points which I want to make about +this let me do this point first + + align:start position:0% + + + + align:start position:0% + +so by virtue of taking a graduate + + align:start position:0% +so by virtue of taking a graduate + + + align:start position:0% +so by virtue of taking a graduate +physics class I'm confident you guys + + align:start position:0% +physics class I'm confident you guys + + + align:start position:0% +physics class I'm confident you guys +know about Newtonian gravity one can + + align:start position:0% +know about Newtonian gravity one can + + + align:start position:0% +know about Newtonian gravity one can +write the field equation for Newtonian + + align:start position:0% +write the field equation for Newtonian + + + align:start position:0% +write the field equation for Newtonian +gravity as essentially a differential + + align:start position:0% +gravity as essentially a differential + + + align:start position:0% +gravity as essentially a differential +equation for the potential that governs + + align:start position:0% +equation for the potential that governs + + + align:start position:0% +equation for the potential that governs +Newtonian gravitational interaction so + + align:start position:0% +Newtonian gravitational interaction so + + + align:start position:0% +Newtonian gravitational interaction so +it's called Phi sub G the Newtonian + + align:start position:0% +it's called Phi sub G the Newtonian + + + align:start position:0% +it's called Phi sub G the Newtonian +gravitational interaction oops and I can + + align:start position:0% +gravitational interaction oops and I can + + + align:start position:0% +gravitational interaction oops and I can +write a field equation that's governing + + align:start position:0% +write a field equation that's governing + + + align:start position:0% +write a field equation that's governing +it as essentially it's poissons equation + + align:start position:0% +it as essentially it's poissons equation + + + align:start position:0% +it as essentially it's poissons equation +okay so the Laplace operator acting on + + align:start position:0% +okay so the Laplace operator acting on + + + align:start position:0% +okay so the Laplace operator acting on +that potential is up to a constant equal + + align:start position:0% +that potential is up to a constant equal + + + align:start position:0% +that potential is up to a constant equal +to Z we usually learn it in terms of + + align:start position:0% +to Z we usually learn it in terms of + + + align:start position:0% +to Z we usually learn it in terms of +mass density we're working in units + + align:start position:0% +mass density we're working in units + + + align:start position:0% +mass density we're working in units +where the speed of light is equal to 1 + + align:start position:0% +where the speed of light is equal to 1 + + + align:start position:0% +where the speed of light is equal to 1 +so it could just as well be the energy + + align:start position:0% +so it could just as well be the energy + + + align:start position:0% +so it could just as well be the energy +density so you've all kind of seen that + + align:start position:0% +density so you've all kind of seen that + + + align:start position:0% +density so you've all kind of seen that +now if we think about how we're going to + + align:start position:0% +now if we think about how we're going to + + + align:start position:0% +now if we think about how we're going to +carry this forward and make gravity a + + align:start position:0% +carry this forward and make gravity a + + + align:start position:0% +carry this forward and make gravity a +relativistic interaction this equation + + align:start position:0% +relativistic interaction this equation + + + align:start position:0% +relativistic interaction this equation +should right away make us suspicious + + align:start position:0% +should right away make us suspicious + + + align:start position:0% +should right away make us suspicious +because we spent several minutes earlier + + align:start position:0% +because we spent several minutes earlier + + + align:start position:0% +because we spent several minutes earlier +today talking about the fact that this + + align:start position:0% +today talking about the fact that this + + + align:start position:0% +today talking about the fact that this +is not a scalar okay this is a component + + align:start position:0% +is not a scalar okay this is a component + + + align:start position:0% +is not a scalar okay this is a component +of a tensor okay a physical theory which + + align:start position:0% +of a tensor okay a physical theory which + + + align:start position:0% +of a tensor okay a physical theory which +tries to pick out just one component of + + align:start position:0% +tries to pick out just one component of + + + align:start position:0% +tries to pick out just one component of +a geometric tensor is not a healthy + + align:start position:0% +a geometric tensor is not a healthy + + + align:start position:0% +a geometric tensor is not a healthy +theory ok it would be like if you had + + align:start position:0% +theory ok it would be like if you had + + + align:start position:0% +theory ok it would be like if you had +sort of learned in enm that you know + + align:start position:0% +sort of learned in enm that you know + + + align:start position:0% +sort of learned in enm that you know +there was a preferred direction the + + align:start position:0% +there was a preferred direction the + + + align:start position:0% +there was a preferred direction the +electric field you know if there's a + + align:start position:0% +electric field you know if there's a + + + align:start position:0% +electric field you know if there's a +particular set of Maxwell's equations + + align:start position:0% +particular set of Maxwell's equations + + + align:start position:0% +particular set of Maxwell's equations +for e^x and the difference then of + + align:start position:0% +for e^x and the difference then of + + + align:start position:0% +for e^x and the difference then of +Maxwell's equations for y Y that would + + align:start position:0% +Maxwell's equations for y Y that would + + + align:start position:0% +Maxwell's equations for y Y that would +just be nonsense + + align:start position:0% +just be nonsense + + + align:start position:0% +just be nonsense +ok nature doesn't pick out spatial + + align:start position:0% +ok nature doesn't pick out spatial + + + align:start position:0% +ok nature doesn't pick out spatial +components of anyone's being + + align:start position:0% +components of anyone's being + + + align:start position:0% +components of anyone's being +particularly uh having some weight over + + align:start position:0% +particularly uh having some weight over + + + align:start position:0% +particularly uh having some weight over +the others and the same thing holds in + + align:start position:0% +the others and the same thing holds in + + + align:start position:0% +the others and the same thing holds in +relativity for space-time so when we + + align:start position:0% +relativity for space-time so when we + + + align:start position:0% +relativity for space-time so when we +make this into a relativistic theory + + align:start position:0% +make this into a relativistic theory + + + align:start position:0% +make this into a relativistic theory +we're gonna say ah + + align:start position:0% +we're gonna say ah + + + align:start position:0% +we're gonna say ah +if this component of a tensor plays a + + align:start position:0% +if this component of a tensor plays a + + + align:start position:0% +if this component of a tensor plays a +large role in gravity to make this into + + align:start position:0% +large role in gravity to make this into + + + align:start position:0% +large role in gravity to make this into +a geometric object that makes a large + + align:start position:0% +a geometric object that makes a large + + + align:start position:0% +a geometric object that makes a large +role in gravity I'm going to have to so + + align:start position:0% +role in gravity I'm going to have to so + + + align:start position:0% +role in gravity I'm going to have to so +let's call this my Newtonian equation my + + align:start position:0% +let's call this my Newtonian equation my + + + align:start position:0% +let's call this my Newtonian equation my +Einstein in equation I'm going to put an + + align:start position:0% +Einstein in equation I'm going to put an + + + align:start position:0% +Einstein in equation I'm going to put an +equal sign in quotes here because + + align:start position:0% +equal sign in quotes here because + + + align:start position:0% +equal sign in quotes here because +there's a lot of details to fill in but + + align:start position:0% +there's a lot of details to fill in but + + + align:start position:0% +there's a lot of details to fill in but +what's going to go on the right-hand + + align:start position:0% +what's going to go on the right-hand + + + align:start position:0% +what's going to go on the right-hand +side of this has to be something that + + align:start position:0% +side of this has to be something that + + + align:start position:0% +side of this has to be something that +involves the stress energy tensor okay + + align:start position:0% +involves the stress energy tensor okay + + + align:start position:0% +involves the stress energy tensor okay +Newton picks out one component of stress + + align:start position:0% +Newton picks out one component of stress + + + align:start position:0% +Newton picks out one component of stress +energy tensor relativity doesn't let me + + align:start position:0% +energy tensor relativity doesn't let me + + + align:start position:0% +energy tensor relativity doesn't let me +pick out particular components so + + align:start position:0% +pick out particular components so + + + align:start position:0% +pick out particular components so +whatever I get when I do Einstein's + + align:start position:0% +whatever I get when I do Einstein's + + + align:start position:0% +whatever I get when I do Einstein's +gravity if the whole stress energy + + align:start position:0% +gravity if the whole stress energy + + + align:start position:0% +gravity if the whole stress energy +tensor is gonna be important in setting + + align:start position:0% +tensor is gonna be important in setting + + + align:start position:0% +tensor is gonna be important in setting +the source of my gravity that then sort + + align:start position:0% +the source of my gravity that then sort + + + align:start position:0% +the source of my gravity that then sort +of says well then what the heck do you + + align:start position:0% +of says well then what the heck do you + + + align:start position:0% +of says well then what the heck do you +do with this left hand side that is in + + align:start position:0% +do with this left hand side that is in + + + align:start position:0% +do with this left hand side that is in +fact going to be starting probably on + + align:start position:0% +fact going to be starting probably on + + + align:start position:0% +fact going to be starting probably on +Tuesday the subject of the next couple + + align:start position:0% +Tuesday the subject of the next couple + + + align:start position:0% +Tuesday the subject of the next couple +of lectures basically going all the way + + align:start position:0% +of lectures basically going all the way + + + align:start position:0% +of lectures basically going all the way +up to spring break okay the week before + + align:start position:0% +up to spring break okay the week before + + + align:start position:0% +up to spring break okay the week before +spring break is when we complete the + + align:start position:0% +spring break is when we complete the + + + align:start position:0% +spring break is when we complete the +story of what goes on the right-hand + + align:start position:0% +story of what goes on the right-hand + + + align:start position:0% +story of what goes on the right-hand +side see me the left-hand side of this + + align:start position:0% +side see me the left-hand side of this + + + align:start position:0% +side see me the left-hand side of this +equation but what I will tell you is + + align:start position:0% +equation but what I will tell you is + + + align:start position:0% +equation but what I will tell you is +that it is indeed going to involve two + + align:start position:0% +that it is indeed going to involve two + + + align:start position:0% +that it is indeed going to involve two +derivatives of a potential like object + + align:start position:0% +derivatives of a potential like object + + + align:start position:0% +derivatives of a potential like object +in the potential like object is that + + align:start position:0% +in the potential like object is that + + + align:start position:0% +in the potential like object is that +you're gonna turn out to be the metric + + align:start position:0% +you're gonna turn out to be the metric + + + align:start position:0% +you're gonna turn out to be the metric +of space-time okay so that's kind of + + align:start position:0% +of space-time okay so that's kind of + + + align:start position:0% +of space-time okay so that's kind of +where we're going with this all right so + + align:start position:0% + + + + align:start position:0% + +let's do a little bit more physics with + + align:start position:0% +let's do a little bit more physics with + + + align:start position:0% +let's do a little bit more physics with +the stress energy tensor + + align:start position:0% + + + + align:start position:0% + +so I'm I have somewhat more detailed + + align:start position:0% +so I'm I have somewhat more detailed + + + align:start position:0% +so I'm I have somewhat more detailed +notes which I will post online which I + + align:start position:0% +notes which I will post online which I + + + align:start position:0% +notes which I will post online which I +am NOT going to go through in great + + align:start position:0% +am NOT going to go through in great + + + align:start position:0% +am NOT going to go through in great +detail here but I'm gonna kind of sketch + + align:start position:0% +detail here but I'm gonna kind of sketch + + + align:start position:0% +detail here but I'm gonna kind of sketch +this so one is that I would like to + + align:start position:0% +this so one is that I would like to + + + align:start position:0% +this so one is that I would like to +prove again that word is a little bit of + + align:start position:0% +prove again that word is a little bit of + + + align:start position:0% +prove again that word is a little bit of +an overstatement but at least motivate + + align:start position:0% +an overstatement but at least motivate + + + align:start position:0% +an overstatement but at least motivate +the symmetry of this tensor okay I'm + + align:start position:0% +the symmetry of this tensor okay I'm + + + align:start position:0% +the symmetry of this tensor okay I'm +just gonna focus on the spatial bits of + + align:start position:0% +just gonna focus on the spatial bits of + + + align:start position:0% +just gonna focus on the spatial bits of +this that'll be enough okay like I said + + align:start position:0% +this that'll be enough okay like I said + + + align:start position:0% +this that'll be enough okay like I said +you can kind of see that T 0 I and ti0 + + align:start position:0% +you can kind of see that T 0 I and ti0 + + + align:start position:0% +you can kind of see that T 0 I and ti0 +are the same thing by thinking about the + + align:start position:0% +are the same thing by thinking about the + + + align:start position:0% +are the same thing by thinking about the +physical meaning of for momentum and + + align:start position:0% +physical meaning of for momentum and + + + align:start position:0% +physical meaning of for momentum and +what a flux of for momentum is this one + + align:start position:0% +what a flux of for momentum is this one + + + align:start position:0% +what a flux of for momentum is this one +there's kind of a cute calculation you + + align:start position:0% +there's kind of a cute calculation you + + + align:start position:0% +there's kind of a cute calculation you +can do so imagine you have some little + + align:start position:0% +can do so imagine you have some little + + + align:start position:0% +can do so imagine you have some little +cube of stuff could be immersed in some + + align:start position:0% +cube of stuff could be immersed in some + + + align:start position:0% +cube of stuff could be immersed in some +field or fluid something that is + + align:start position:0% +field or fluid something that is + + + align:start position:0% +field or fluid something that is +described by a field of stress energy + + align:start position:0% + + + + align:start position:0% + +and so to start out with let's look at + + align:start position:0% +and so to start out with let's look at + + + align:start position:0% +and so to start out with let's look at +how the flux of member with T alpha beta + + align:start position:0% +how the flux of member with T alpha beta + + + align:start position:0% +how the flux of member with T alpha beta +are really T IJ tells me about is the + + align:start position:0% +are really T IJ tells me about is the + + + align:start position:0% +are really T IJ tells me about is the +flux of momentum in a particular + + align:start position:0% +flux of momentum in a particular + + + align:start position:0% +flux of momentum in a particular +direction it's tell me about the amount + + align:start position:0% +direction it's tell me about the amount + + + align:start position:0% +direction it's tell me about the amount +of momentum going into this box on one + + align:start position:0% +of momentum going into this box on one + + + align:start position:0% +of momentum going into this box on one +side and coming out on the other okay so + + align:start position:0% +side and coming out on the other okay so + + + align:start position:0% +side and coming out on the other okay so +I'm going to look at the momentum flux + + align:start position:0% +I'm going to look at the momentum flux + + + align:start position:0% +I'm going to look at the momentum flux +into and out of this box + + align:start position:0% +into and out of this box + + + align:start position:0% +into and out of this box +and so what I'm going to do is let's + + align:start position:0% +and so what I'm going to do is let's + + + align:start position:0% +and so what I'm going to do is let's +look at the momentum going into the + + align:start position:0% +look at the momentum going into the + + + align:start position:0% +look at the momentum going into the +sides that are so let's call this the + + align:start position:0% +sides that are so let's call this the + + + align:start position:0% +sides that are so let's call this the +top and the bottom here what I'm going + + align:start position:0% +top and the bottom here what I'm going + + + align:start position:0% +top and the bottom here what I'm going +to do then is number the four sides the + + align:start position:0% +to do then is number the four sides the + + + align:start position:0% +to do then is number the four sides the +other four side of the box not the top + + align:start position:0% +other four side of the box not the top + + + align:start position:0% +other four side of the box not the top +and the bottom so let's call this side + + align:start position:0% +and the bottom so let's call this side + + + align:start position:0% +and the bottom so let's call this side +which is sort of facing away from us + + align:start position:0% +which is sort of facing away from us + + + align:start position:0% +which is sort of facing away from us +here that side one the one that is + + align:start position:0% +here that side one the one that is + + + align:start position:0% +here that side one the one that is +facing us that sort of points out in the + + align:start position:0% +facing us that sort of points out in the + + + align:start position:0% +facing us that sort of points out in the +X direction I'll call that two this side + + align:start position:0% +X direction I'll call that two this side + + + align:start position:0% +X direction I'll call that two this side +here I will call three and the one that + + align:start position:0% +here I will call three and the one that + + + align:start position:0% +here I will call three and the one that +is on the back I will call for apologies + + align:start position:0% +is on the back I will call for apologies + + + align:start position:0% +is on the back I will call for apologies +for the little bit of a a busy picture + + align:start position:0% +for the little bit of a a busy picture + + + align:start position:0% +for the little bit of a a busy picture +here but just what you want to do is + + align:start position:0% +here but just what you want to do is + + + align:start position:0% +here but just what you want to do is +there the matting of this cube in front + + align:start position:0% +there the matting of this cube in front + + + align:start position:0% +there the matting of this cube in front +of you and you go around and label the + + align:start position:0% +of you and you go around and label the + + + align:start position:0% +of you and you go around and label the +four sides + + align:start position:0% + + + + align:start position:0% + +what we'd like to do is calculate what + + align:start position:0% +what we'd like to do is calculate what + + + align:start position:0% +what we'd like to do is calculate what +is the force that is flowing through + + align:start position:0% +is the force that is flowing through + + + align:start position:0% +is the force that is flowing through +each of these four sides okay one two + + align:start position:0% +each of these four sides okay one two + + + align:start position:0% +each of these four sides okay one two +three and four let's ignore the top and + + align:start position:0% +three and four let's ignore the top and + + + align:start position:0% +three and four let's ignore the top and +the bottom for just a second + + align:start position:0% +the bottom for just a second + + + align:start position:0% +the bottom for just a second +I'll describe why that is in just a + + align:start position:0% +I'll describe why that is in just a + + + align:start position:0% +I'll describe why that is in just a +moment so if I look at the force on face + + align:start position:0% +moment so if I look at the force on face + + + align:start position:0% +moment so if I look at the force on face +one okay + + align:start position:0% +one okay + + + align:start position:0% +one okay +well face one is pardon me I mislabeled + + align:start position:0% +well face one is pardon me I mislabeled + + + align:start position:0% +well face one is pardon me I mislabeled +my sides I want to be synced up with my + + align:start position:0% +my sides I want to be synced up with my + + + align:start position:0% +my sides I want to be synced up with my +notes and so I realized it's annoying + + align:start position:0% +notes and so I realized it's annoying + + + align:start position:0% +notes and so I realized it's annoying +and I'm very sorry about that but if I + + align:start position:0% +and I'm very sorry about that but if I + + + align:start position:0% +and I'm very sorry about that but if I +mess this up I will get out of sync with + + align:start position:0% +mess this up I will get out of sync with + + + align:start position:0% +mess this up I will get out of sync with +what I have written down so the one that + + align:start position:0% +what I have written down so the one that + + + align:start position:0% +what I have written down so the one that +is facing us is side one two is on the + + align:start position:0% +is facing us is side one two is on the + + + align:start position:0% +is facing us is side one two is on the +right-hand side three is the back four + + align:start position:0% +right-hand side three is the back four + + + align:start position:0% +right-hand side three is the back four +is on the left-hand side my apologies + + align:start position:0% +is on the left-hand side my apologies + + + align:start position:0% +is on the left-hand side my apologies +for that but I think it's important we + + align:start position:0% +for that but I think it's important we + + + align:start position:0% +for that but I think it's important we +get that right so I don't get out of + + align:start position:0% +get that right so I don't get out of + + + align:start position:0% +get that right so I don't get out of +synch with myself so the total force on + + align:start position:0% +synch with myself so the total force on + + + align:start position:0% +synch with myself so the total force on +face one is what I get by basically + + align:start position:0% +face one is what I get by basically + + + align:start position:0% +face one is what I get by basically +adding up all the flux of momentum + + align:start position:0% +adding up all the flux of momentum + + + align:start position:0% +adding up all the flux of momentum +flowing through face one so force on + + align:start position:0% +flowing through face one so force on + + + align:start position:0% +flowing through face one so force on +face one that is the ithe component of + + align:start position:0% +face one that is the ithe component of + + + align:start position:0% +face one that is the ithe component of +that is what I get when I integrate that + + align:start position:0% +that is what I get when I integrate that + + + align:start position:0% +that is what I get when I integrate that +over face one which is normal to the + + align:start position:0% +over face one which is normal to the + + + align:start position:0% +over face one which is normal to the +x-axis each side of the cube is little L + + align:start position:0% +x-axis each side of the cube is little L + + + align:start position:0% +x-axis each side of the cube is little L +so it's t IX l squared okay + + align:start position:0% + + + + align:start position:0% + +force on face - okay now this is the one + + align:start position:0% +force on face - okay now this is the one + + + align:start position:0% +force on face - okay now this is the one +that is normal to the y-axis and so this + + align:start position:0% +that is normal to the y-axis and so this + + + align:start position:0% +that is normal to the y-axis and so this +guy looks like t iy l l squared okay and + + align:start position:0% +guy looks like t iy l l squared okay and + + + align:start position:0% +guy looks like t iy l l squared okay and +if you continue this f3 you look at that + + align:start position:0% +if you continue this f3 you look at that + + + align:start position:0% +if you continue this f3 you look at that +and you know if you assume that this + + align:start position:0% +and you know if you assume that this + + + align:start position:0% +and you know if you assume that this +thing is small it's approximately the + + align:start position:0% + + + + align:start position:0% + +same as the force on f1 it'll become + + align:start position:0% +same as the force on f1 it'll become + + + align:start position:0% +same as the force on f1 it'll become +equal in the limit of the cube becoming + + align:start position:0% +equal in the limit of the cube becoming + + + align:start position:0% +equal in the limit of the cube becoming +infinitesimally small and this is + + align:start position:0% +infinitesimally small and this is + + + align:start position:0% +infinitesimally small and this is +approximately the same as the force on + + align:start position:0% +approximately the same as the force on + + + align:start position:0% +approximately the same as the force on +Phase two + + align:start position:0% +Phase two + + + align:start position:0% +Phase two +so that tells us that there's no + + align:start position:0% +so that tells us that there's no + + + align:start position:0% +so that tells us that there's no +unbalanced force on this thing which is + + align:start position:0% +unbalanced force on this thing which is + + + align:start position:0% +unbalanced force on this thing which is +great + + align:start position:0% + + + + align:start position:0% + +basically it means that you know there's + + align:start position:0% +basically it means that you know there's + + + align:start position:0% +basically it means that you know there's +no unbalanced force causing this little + + align:start position:0% +no unbalanced force causing this little + + + align:start position:0% +no unbalanced force causing this little +element to accelerate away one of the + + align:start position:0% +element to accelerate away one of the + + + align:start position:0% +element to accelerate away one of the +reasons why I am focusing on these four + + align:start position:0% +reasons why I am focusing on these four + + + align:start position:0% +reasons why I am focusing on these four +sides though is I would also like to + + align:start position:0% +sides though is I would also like to + + + align:start position:0% +sides though is I would also like to +consider torques that are acting on this + + align:start position:0% +consider torques that are acting on this + + + align:start position:0% +consider torques that are acting on this +thing + + align:start position:0% + + + + align:start position:0% + +and here's where I'm gonna skip over a + + align:start position:0% +and here's where I'm gonna skip over a + + + align:start position:0% +and here's where I'm gonna skip over a +couple of details and just leave a few + + align:start position:0% +couple of details and just leave a few + + + align:start position:0% +couple of details and just leave a few +notes for you guys to look X we're a + + align:start position:0% +notes for you guys to look X we're a + + + align:start position:0% +notes for you guys to look X we're a +little short on time if there are things + + align:start position:0% +little short on time if there are things + + + align:start position:0% +little short on time if there are things +this calculation is straightforward but + + align:start position:0% +this calculation is straightforward but + + + align:start position:0% +this calculation is straightforward but +it gets I already screwed up a detail + + align:start position:0% +it gets I already screwed up a detail + + + align:start position:0% +it gets I already screwed up a detail +here I don't want to sort of risk + + align:start position:0% +here I don't want to sort of risk + + + align:start position:0% +here I don't want to sort of risk +messing up a few other things what I + + align:start position:0% +messing up a few other things what I + + + align:start position:0% +messing up a few other things what I +want to do is consider the torques about + + align:start position:0% +want to do is consider the torques about + + + align:start position:0% +want to do is consider the torques about +an axis that sort of runs through the + + align:start position:0% +an axis that sort of runs through the + + + align:start position:0% +an axis that sort of runs through the +middle of this thing because it's from + + align:start position:0% +middle of this thing because it's from + + + align:start position:0% +middle of this thing because it's from +the top and the bottom of this okay so + + align:start position:0% +the top and the bottom of this okay so + + + align:start position:0% +the top and the bottom of this okay so +go through and just add up all the + + align:start position:0% +go through and just add up all the + + + align:start position:0% +go through and just add up all the +torques associated these little forces + + align:start position:0% +torques associated these little forces + + + align:start position:0% +torques associated these little forces +about an axis in the center of that goes + + align:start position:0% +about an axis in the center of that goes + + + align:start position:0% +about an axis in the center of that goes +through the center of this cube okay so + + align:start position:0% +through the center of this cube okay so + + + align:start position:0% +through the center of this cube okay so +I'm going out like I said I'm gonna + + align:start position:0% +I'm going out like I said I'm gonna + + + align:start position:0% +I'm going out like I said I'm gonna +leave out the details but basically you + + align:start position:0% +leave out the details but basically you + + + align:start position:0% +leave out the details but basically you +go through and you do the usual R cross + + align:start position:0% +go through and you do the usual R cross + + + align:start position:0% +go through and you do the usual R cross +F to get the forces the torques + + align:start position:0% +F to get the forces the torques + + + align:start position:0% +F to get the forces the torques +associate with each of these different + + align:start position:0% +associate with each of these different + + + align:start position:0% +associate with each of these different +faces + + align:start position:0% + + + + align:start position:0% + +and what you'll find when you do this is + + align:start position:0% +and what you'll find when you do this is + + + align:start position:0% +and what you'll find when you do this is +that there is a net torque that looks + + align:start position:0% +that there is a net torque that looks + + + align:start position:0% +that there is a net torque that looks +like L cubed times T XY minus T YX + + align:start position:0% +like L cubed times T XY minus T YX + + + align:start position:0% +like L cubed times T XY minus T YX +again though this scales with the size + + align:start position:0% +again though this scales with the size + + + align:start position:0% +again though this scales with the size +of the cube right so you look at this + + align:start position:0% +of the cube right so you look at this + + + align:start position:0% +of the cube right so you look at this +and kind of go well who cares you know + + align:start position:0% +and kind of go well who cares you know + + + align:start position:0% +and kind of go well who cares you know +it's a little bit there maybe it spins + + align:start position:0% +it's a little bit there maybe it spins + + + align:start position:0% +it's a little bit there maybe it spins +up a little bit but in the limit this + + align:start position:0% +up a little bit but in the limit this + + + align:start position:0% +up a little bit but in the limit this +thing going to zero there's no net + + align:start position:0% +thing going to zero there's no net + + + align:start position:0% +thing going to zero there's no net +effect well let's be a little bit + + align:start position:0% +effect well let's be a little bit + + + align:start position:0% +effect well let's be a little bit +careful about this what is the moment of + + align:start position:0% +careful about this what is the moment of + + + align:start position:0% +careful about this what is the moment of +inertia of this cube I don't know + + align:start position:0% +inertia of this cube I don't know + + + align:start position:0% +inertia of this cube I don't know +exactly but I know that it's going to be + + align:start position:0% +exactly but I know that it's going to be + + + align:start position:0% +exactly but I know that it's going to be +something like the mass of this cube + + align:start position:0% + + + + align:start position:0% + +we'll call that L cubed times its mass + + align:start position:0% +we'll call that L cubed times its mass + + + align:start position:0% +we'll call that L cubed times its mass +density or its energy density and it's + + align:start position:0% +density or its energy density and it's + + + align:start position:0% +density or its energy density and it's +going to involve two powers of the only + + align:start position:0% +going to involve two powers of the only + + + align:start position:0% +going to involve two powers of the only +length scale characterizing this thing + + align:start position:0% +length scale characterizing this thing + + + align:start position:0% +length scale characterizing this thing +and there'll be some pre factor alpha + + align:start position:0% +and there'll be some pre factor alpha + + + align:start position:0% +and there'll be some pre factor alpha +there'll be some number that's related + + align:start position:0% +there'll be some number that's related + + + align:start position:0% +there'll be some number that's related +to the geometry of this okay an integral + + align:start position:0% +to the geometry of this okay an integral + + + align:start position:0% +to the geometry of this okay an integral +or two will easily work out what the + + align:start position:0% +or two will easily work out what the + + + align:start position:0% +or two will easily work out what the +Alpha is and make this more precise but + + align:start position:0% +Alpha is and make this more precise but + + + align:start position:0% +Alpha is and make this more precise but +the key bit which I want to emphasize is + + align:start position:0% +the key bit which I want to emphasize is + + + align:start position:0% +the key bit which I want to emphasize is +that this is something that scales as + + align:start position:0% +that this is something that scales as + + + align:start position:0% +that this is something that scales as +the size of the fifth power + + align:start position:0% + + + + align:start position:0% + +so yeah the torque vanishes as L goes to + + align:start position:0% +so yeah the torque vanishes as L goes to + + + align:start position:0% +so yeah the torque vanishes as L goes to +zero but it does so with the cubed power + + align:start position:0% +zero but it does so with the cubed power + + + align:start position:0% +zero but it does so with the cubed power +it doesn't vanish as quickly as the + + align:start position:0% +it doesn't vanish as quickly as the + + + align:start position:0% +it doesn't vanish as quickly as the +moment of inertia vanishes and I'll + + align:start position:0% +moment of inertia vanishes and I'll + + + align:start position:0% +moment of inertia vanishes and I'll +remind you the angular acceleration of + + align:start position:0% +remind you the angular acceleration of + + + align:start position:0% +remind you the angular acceleration of +the cube theta double dot is the torque + + align:start position:0% +the cube theta double dot is the torque + + + align:start position:0% +the cube theta double dot is the torque +divided by the moan of inertia so this + + align:start position:0% +divided by the moan of inertia so this + + + align:start position:0% +divided by the moan of inertia so this +is something that is proportional to t + + align:start position:0% +is something that is proportional to t + + + align:start position:0% +is something that is proportional to t +XY minus T Y + + align:start position:0% +XY minus T Y + + + align:start position:0% +XY minus T Y +/ l squared + + align:start position:0% + + + + align:start position:0% + +so yeah the torque does vanish as L goes + + align:start position:0% +so yeah the torque does vanish as L goes + + + align:start position:0% +so yeah the torque does vanish as L goes +to zero but the moment of inertia + + align:start position:0% +to zero but the moment of inertia + + + align:start position:0% +to zero but the moment of inertia +vanishes more rapidly as L goes to zero + + align:start position:0% +vanishes more rapidly as L goes to zero + + + align:start position:0% +vanishes more rapidly as L goes to zero +that sort of suggests that if we're in a + + align:start position:0% +that sort of suggests that if we're in a + + + align:start position:0% +that sort of suggests that if we're in a +screwy universe little microscopic + + align:start position:0% +screwy universe little microscopic + + + align:start position:0% +screwy universe little microscopic +vortices are just gonna start randomly + + align:start position:0% +vortices are just gonna start randomly + + + align:start position:0% +vortices are just gonna start randomly +oscillating in any cup of water that you + + align:start position:0% +oscillating in any cup of water that you + + + align:start position:0% +oscillating in any cup of water that you +pour it in front of you now I don't have + + align:start position:0% +pour it in front of you now I don't have + + + align:start position:0% +pour it in front of you now I don't have +a proof that nature abhors that but it + + align:start position:0% +a proof that nature abhors that but it + + + align:start position:0% +a proof that nature abhors that but it +seems pretty screwy and so the case that + + align:start position:0% +seems pretty screwy and so the case that + + + align:start position:0% +seems pretty screwy and so the case that +most textbooks make at this point is to + + align:start position:0% +most textbooks make at this point is to + + + align:start position:0% +most textbooks make at this point is to +say physics indicates we must have txy + + align:start position:0% +say physics indicates we must have txy + + + align:start position:0% +say physics indicates we must have txy +strikingly equal to G YX in all cases + + align:start position:0% +strikingly equal to G YX in all cases + + + align:start position:0% +strikingly equal to G YX in all cases +independent of what the size of this + + align:start position:0% +independent of what the size of this + + + align:start position:0% +independent of what the size of this +thing is okay that had better just be a + + align:start position:0% +thing is okay that had better just be a + + + align:start position:0% +thing is okay that had better just be a +bloody zero in the numerator in order to + + align:start position:0% +bloody zero in the numerator in order to + + + align:start position:0% +bloody zero in the numerator in order to +prevent this physical absurdity from + + align:start position:0% +prevent this physical absurdity from + + + align:start position:0% +prevent this physical absurdity from +being set up repeat the exercise by + + align:start position:0% +being set up repeat the exercise by + + + align:start position:0% +being set up repeat the exercise by +looking at torques around the other axes + + align:start position:0% +looking at torques around the other axes + + + align:start position:0% +looking at torques around the other axes +and that drives you to the statement + + align:start position:0% +and that drives you to the statement + + + align:start position:0% +and that drives you to the statement +that this thing must in general be + + align:start position:0% +that this thing must in general be + + + align:start position:0% +that this thing must in general be +spatially symmetric and again physics of + + align:start position:0% +spatially symmetric and again physics of + + + align:start position:0% +spatially symmetric and again physics of +the way that energy momentum behaved in + + align:start position:0% +the way that energy momentum behaved in + + + align:start position:0% +the way that energy momentum behaved in +relativity makes our sort of time-space + + align:start position:0% +relativity makes our sort of time-space + + + align:start position:0% +relativity makes our sort of time-space +component symmetric as well I emphasize + + align:start position:0% +component symmetric as well I emphasize + + + align:start position:0% +component symmetric as well I emphasize +this is not a proof this is really just + + align:start position:0% +this is not a proof this is really just + + + align:start position:0% +this is not a proof this is really just +a physical motivation this is the kind + + align:start position:0% +a physical motivation this is the kind + + + align:start position:0% +a physical motivation this is the kind +of thing that I'm a bloody + + align:start position:0% +of thing that I'm a bloody + + + align:start position:0% +of thing that I'm a bloody +astrophysicist I like this kind of stuff + + align:start position:0% +astrophysicist I like this kind of stuff + + + align:start position:0% +astrophysicist I like this kind of stuff +there is a different way of developing + + align:start position:0% +there is a different way of developing + + + align:start position:0% +there is a different way of developing +the stress energy tensor as I said that + + align:start position:0% +the stress energy tensor as I said that + + + align:start position:0% +the stress energy tensor as I said that +comes from a variational principle sort + + align:start position:0% +comes from a variational principle sort + + + align:start position:0% +comes from a variational principle sort +of based on a sort of quantum field + + align:start position:0% +of based on a sort of quantum field + + + align:start position:0% +of based on a sort of quantum field +field theoretic type of methods and the + + align:start position:0% +field theoretic type of methods and the + + + align:start position:0% +field theoretic type of methods and the +symmetry in that case is manifest okay + + align:start position:0% +symmetry in that case is manifest okay + + + align:start position:0% +symmetry in that case is manifest okay +it really does would have come up but + + align:start position:0% +it really does would have come up but + + + align:start position:0% +it really does would have come up but +this is a good way of just motivating + + align:start position:0% +this is a good way of just motivating + + + align:start position:0% +this is a good way of just motivating +the fact that you're not gonna have any + + align:start position:0% +the fact that you're not gonna have any + + + align:start position:0% +the fact that you're not gonna have any +non diagonal or something non symmetric + + align:start position:0% +non diagonal or something non symmetric + + + align:start position:0% +non diagonal or something non symmetric +stretch energy time sirs if you did you + + align:start position:0% +stretch energy time sirs if you did you + + + align:start position:0% +stretch energy time sirs if you did you +would have really bizarre matter + + align:start position:0% +would have really bizarre matter + + + align:start position:0% + +all right now the stress-energy tensor + + align:start position:0% +all right now the stress-energy tensor + + + align:start position:0% +all right now the stress-energy tensor +has this physical interpretation that it + + align:start position:0% +has this physical interpretation that it + + + align:start position:0% +has this physical interpretation that it +tells me about the flow of energy and + + align:start position:0% +tells me about the flow of energy and + + + align:start position:0% +tells me about the flow of energy and +the flow of momentum in space-time as + + align:start position:0% +the flow of momentum in space-time as + + + align:start position:0% +the flow of momentum in space-time as +such it is the tool by which we are + + align:start position:0% +such it is the tool by which we are + + + align:start position:0% +such it is the tool by which we are +going to put conservation of energy and + + align:start position:0% +going to put conservation of energy and + + + align:start position:0% +going to put conservation of energy and +conservation of momentum into our theory + + align:start position:0% + + + + align:start position:0% + +in the way we're going to do this is + + align:start position:0% +in the way we're going to do this is + + + align:start position:0% +in the way we're going to do this is +with a remarkably simple equation the + + align:start position:0% +with a remarkably simple equation the + + + align:start position:0% +with a remarkably simple equation the +space-time divergence of T alpha beta + + align:start position:0% + + + + align:start position:0% + +must equal zero this is a covariant + + align:start position:0% +must equal zero this is a covariant + + + align:start position:0% +must equal zero this is a covariant +formulation of both conservation of + + align:start position:0% +formulation of both conservation of + + + align:start position:0% +formulation of both conservation of +energy and conservation of momentum and + + align:start position:0% +energy and conservation of momentum and + + + align:start position:0% +energy and conservation of momentum and +if you want to say well which one is + + align:start position:0% +if you want to say well which one is + + + align:start position:0% +if you want to say well which one is +that energy or is it momentum you can't + + align:start position:0% +that energy or is it momentum you can't + + + align:start position:0% +that energy or is it momentum you can't +say that in general okay I can only say + + align:start position:0% +say that in general okay I can only say + + + align:start position:0% +say that in general okay I can only say +that after I have picked a particular + + align:start position:0% +that after I have picked a particular + + + align:start position:0% +that after I have picked a particular +reference frame because it's only once I + + align:start position:0% +reference frame because it's only once I + + + align:start position:0% +reference frame because it's only once I +have defined time and I've defined space + + align:start position:0% +have defined time and I've defined space + + + align:start position:0% +have defined time and I've defined space +that I've actually defined energy and + + align:start position:0% +that I've actually defined energy and + + + align:start position:0% +that I've actually defined energy and +momentum okay prior to choosing a + + align:start position:0% +momentum okay prior to choosing a + + + align:start position:0% +momentum okay prior to choosing a +particular reference frame all I have is + + align:start position:0% +particular reference frame all I have is + + + align:start position:0% +particular reference frame all I have is +for momentum one observers energy is + + align:start position:0% +for momentum one observers energy is + + + align:start position:0% +for momentum one observers energy is +another observer superposition of energy + + align:start position:0% +another observer superposition of energy + + + align:start position:0% +another observer superposition of energy +and momentum once I have picked a + + align:start position:0% +and momentum once I have picked a + + + align:start position:0% +and momentum once I have picked a +particular frame + + align:start position:0% + + + + align:start position:0% + +so once I have picked a particular frame + + align:start position:0% + + + + align:start position:0% + +then if I evaluate D alpha T alpha + + align:start position:0% +then if I evaluate D alpha T alpha + + + align:start position:0% +then if I evaluate D alpha T alpha +either 0 or T this is what conservation + + align:start position:0% +either 0 or T this is what conservation + + + align:start position:0% +either 0 or T this is what conservation +of energy looks like in that frame so in + + align:start position:0% +of energy looks like in that frame so in + + + align:start position:0% +of energy looks like in that frame so in +that frame here is conservation of + + align:start position:0% +that frame here is conservation of + + + align:start position:0% +that frame here is conservation of +energy and + + align:start position:0% +energy and + + + align:start position:0% +energy and +[Music] + + align:start position:0% + + + + align:start position:0% + +right the first one yeah sorry just try + + align:start position:0% +right the first one yeah sorry just try + + + align:start position:0% +right the first one yeah sorry just try +to make sure I got my indices lined up + + align:start position:0% +to make sure I got my indices lined up + + + align:start position:0% +to make sure I got my indices lined up +properly so you can't quite read the + + align:start position:0% +properly so you can't quite read the + + + align:start position:0% +properly so you can't quite read the +bottom one so well top one is + + align:start position:0% +bottom one so well top one is + + + align:start position:0% +bottom one so well top one is +conservation of energy in that + + align:start position:0% +conservation of energy in that + + + align:start position:0% +conservation of energy in that +particular frame second one is + + align:start position:0% +particular frame second one is + + + align:start position:0% +particular frame second one is +conservation of momentum in that + + align:start position:0% +conservation of momentum in that + + + align:start position:0% +conservation of momentum in that +particular frame okay and again the key + + align:start position:0% +particular frame okay and again the key + + + align:start position:0% +particular frame okay and again the key +thing which I wanted to emphasize is the + + align:start position:0% +thing which I wanted to emphasize is the + + + align:start position:0% +thing which I wanted to emphasize is the +covariant statement basically puts both + + align:start position:0% +covariant statement basically puts both + + + align:start position:0% +covariant statement basically puts both +of them together into a single equation + + align:start position:0% +of them together into a single equation + + + align:start position:0% +of them together into a single equation +I can only sensibly state conservation + + align:start position:0% +I can only sensibly state conservation + + + align:start position:0% +I can only sensibly state conservation +of energy and conservation of momentum + + align:start position:0% +of energy and conservation of momentum + + + align:start position:0% +of energy and conservation of momentum +according to some particular observer + + align:start position:0% +according to some particular observer + + + align:start position:0% +according to some particular observer +now I can repeat the game that I had + + align:start position:0% +now I can repeat the game that I had + + + align:start position:0% +now I can repeat the game that I had +done before with the number vector and + + align:start position:0% +done before with the number vector and + + + align:start position:0% +done before with the number vector and +turn these conservation laws into + + align:start position:0% +turn these conservation laws into + + + align:start position:0% +turn these conservation laws into +integral equations as well let me do it + + align:start position:0% +integral equations as well let me do it + + + align:start position:0% +integral equations as well let me do it +for energy + + align:start position:0% + + + + align:start position:0% + +so if I take that integral equation and + + align:start position:0% +so if I take that integral equation and + + + align:start position:0% +so if I take that integral equation and +integrate over a three-volume + + align:start position:0% +integrate over a three-volume + + + align:start position:0% +integrate over a three-volume +or if you prefer I can take the the + + align:start position:0% +or if you prefer I can take the the + + + align:start position:0% +or if you prefer I can take the the +original covariant formulation integrate + + align:start position:0% +original covariant formulation integrate + + + align:start position:0% +original covariant formulation integrate +that over a four-volume + + align:start position:0% +that over a four-volume + + + align:start position:0% +that over a four-volume +with a little bit of manipulation akin + + align:start position:0% +with a little bit of manipulation akin + + + align:start position:0% +with a little bit of manipulation akin +to the way I manipulated the + + align:start position:0% +to the way I manipulated the + + + align:start position:0% +to the way I manipulated the +conservation Tugrul associate the number + + align:start position:0% +conservation Tugrul associate the number + + + align:start position:0% +conservation Tugrul associate the number +vector in the previous lecture you can + + align:start position:0% +vector in the previous lecture you can + + + align:start position:0% +vector in the previous lecture you can +write down a law that looks like this + + align:start position:0% + + + + align:start position:0% + +okay and so this again what I've done + + align:start position:0% +okay and so this again what I've done + + + align:start position:0% +okay and so this again what I've done +here is I've chosen a particular set of + + align:start position:0% +here is I've chosen a particular set of + + + align:start position:0% +here is I've chosen a particular set of +time like coordinates and the language + + align:start position:0% +time like coordinates and the language + + + align:start position:0% +time like coordinates and the language +that we often use in relativity is we + + align:start position:0% +that we often use in relativity is we + + + align:start position:0% +that we often use in relativity is we +basically say I'm going to take a single + + align:start position:0% +basically say I'm going to take a single + + + align:start position:0% +basically say I'm going to take a single +slice of time and I would say that the + + align:start position:0% +slice of time and I would say that the + + + align:start position:0% +slice of time and I would say that the +rate of change of energy so integrate + + align:start position:0% +rate of change of energy so integrate + + + align:start position:0% +rate of change of energy so integrate +energy over a volume it's the total + + align:start position:0% +energy over a volume it's the total + + + align:start position:0% +energy over a volume it's the total +energy in that v3 the rate of change of + + align:start position:0% +energy in that v3 the rate of change of + + + align:start position:0% +energy in that v3 the rate of change of +that thing is balanced by the amount of + + align:start position:0% +that thing is balanced by the amount of + + + align:start position:0% +that thing is balanced by the amount of +energy flowing into or out of through + + align:start position:0% +energy flowing into or out of through + + + align:start position:0% +energy flowing into or out of through +the boundaries of that volume okay add + + align:start position:0% +the boundaries of that volume okay add + + + align:start position:0% +the boundaries of that volume okay add +an extra index here so make this this + + align:start position:0% +an extra index here so make this this + + + align:start position:0% +an extra index here so make this this +make one of these be a J make this guy + + align:start position:0% +make one of these be a J make this guy + + + align:start position:0% +make one of these be a J make this guy +be a J and you've got a similar + + align:start position:0% +be a J and you've got a similar + + + align:start position:0% +be a J and you've got a similar +statement for the conservation of + + align:start position:0% +statement for the conservation of + + + align:start position:0% +statement for the conservation of +momentum okay this is a particular trick + + align:start position:0% +momentum okay this is a particular trick + + + align:start position:0% +momentum okay this is a particular trick +I have a set of typed up notes that just + + align:start position:0% +I have a set of typed up notes that just + + + align:start position:0% +I have a set of typed up notes that just +sort of cleaned this up a little bit + + align:start position:0% +sort of cleaned this up a little bit + + + align:start position:0% +sort of cleaned this up a little bit +they're basically exactly this point but + + align:start position:0% +they're basically exactly this point but + + + align:start position:0% +they're basically exactly this point but +I'll put them online after today's + + align:start position:0% +I'll put them online after today's + + + align:start position:0% +I'll put them online after today's +lecture you're going to want to use this + + align:start position:0% +lecture you're going to want to use this + + + align:start position:0% +lecture you're going to want to use this +on one of the pset problems this week + + align:start position:0% +on one of the pset problems this week + + + align:start position:0% +on one of the pset problems this week +okay so you guys are going to do a + + align:start position:0% +okay so you guys are going to do a + + + align:start position:0% +okay so you guys are going to do a +couple exercise that involves + + align:start position:0% +couple exercise that involves + + + align:start position:0% +couple exercise that involves +integrating and actually finding + + align:start position:0% +integrating and actually finding + + + align:start position:0% +integrating and actually finding +essentially moments of the left-hand + + align:start position:0% +essentially moments of the left-hand + + + align:start position:0% +essentially moments of the left-hand +side of this thing okay we're going to + + align:start position:0% +side of this thing okay we're going to + + + align:start position:0% +side of this thing okay we're going to +do a few exercises where you take + + align:start position:0% +do a few exercises where you take + + + align:start position:0% +do a few exercises where you take +advantage of this constant this + + align:start position:0% +advantage of this constant this + + + align:start position:0% +advantage of this constant this +formulation of conservation of energy + + align:start position:0% +formulation of conservation of energy + + + align:start position:0% +formulation of conservation of energy +and momentum to derive a few identities + + align:start position:0% +and momentum to derive a few identities + + + align:start position:0% +and momentum to derive a few identities +involving the stress energy tensor + + align:start position:0% +involving the stress energy tensor + + + align:start position:0% +involving the stress energy tensor +one of which is another Easter Egg that + + align:start position:0% +one of which is another Easter Egg that + + + align:start position:0% +one of which is another Easter Egg that +we're going to use quite a bit in a + + align:start position:0% +we're going to use quite a bit in a + + + align:start position:0% +we're going to use quite a bit in a +future lecture all right so we just wrap + + align:start position:0% +future lecture all right so we just wrap + + + align:start position:0% +future lecture all right so we just wrap +up our discussion of the stress energy + + align:start position:0% +up our discussion of the stress energy + + + align:start position:0% +up our discussion of the stress energy +tensor by just doing two more examples + + align:start position:0% +tensor by just doing two more examples + + + align:start position:0% +tensor by just doing two more examples +and then I'm gonna sort of begin + + align:start position:0% +and then I'm gonna sort of begin + + + align:start position:0% +and then I'm gonna sort of begin +switching gears a little bit so so far I + + align:start position:0% +switching gears a little bit so so far I + + + align:start position:0% +switching gears a little bit so so far I +have only described essentially I've + + align:start position:0% +have only described essentially I've + + + align:start position:0% +have only described essentially I've +really only described perfect fluids + + align:start position:0% +really only described perfect fluids + + + align:start position:0% +really only described perfect fluids +okay + + align:start position:0% +okay + + + align:start position:0% +okay +dust is a perfect fluid with no pressure + + align:start position:0% + + + + align:start position:0% + +there are a lot of other kinds of + + align:start position:0% +there are a lot of other kinds of + + + align:start position:0% +there are a lot of other kinds of +materials that we want to work with in + + align:start position:0% +materials that we want to work with in + + + align:start position:0% +materials that we want to work with in +the universe one of them which it's + + align:start position:0% +the universe one of them which it's + + + align:start position:0% +the universe one of them which it's +unlikely many of you were going to use + + align:start position:0% +unlikely many of you were going to use + + + align:start position:0% +unlikely many of you were going to use +this but it's actually the stress energy + + align:start position:0% +this but it's actually the stress energy + + + align:start position:0% +this but it's actually the stress energy +tensor on which I have built I have + + align:start position:0% +tensor on which I have built I have + + + align:start position:0% +tensor on which I have built I have +built a big chunk of my career is + + align:start position:0% +built a big chunk of my career is + + + align:start position:0% +built a big chunk of my career is +suppose you have you know we kind of + + align:start position:0% +suppose you have you know we kind of + + + align:start position:0% +suppose you have you know we kind of +talked a little bit about how the four + + align:start position:0% +talked a little bit about how the four + + + align:start position:0% +talked a little bit about how the four +velocity in the four momentum but really + + align:start position:0% +velocity in the four momentum but really + + + align:start position:0% +velocity in the four momentum but really +only good we're talking about like the + + align:start position:0% +only good we're talking about like the + + + align:start position:0% +only good we're talking about like the +kinematics of particles well actually + + align:start position:0% +kinematics of particles well actually + + + align:start position:0% +kinematics of particles well actually +particles aren't a bad thing to focus on + + align:start position:0% +particles aren't a bad thing to focus on + + + align:start position:0% +particles aren't a bad thing to focus on +in some of your studies okay and much of + + align:start position:0% +in some of your studies okay and much of + + + align:start position:0% +in some of your studies okay and much of +my research is actually based on the + + align:start position:0% +my research is actually based on the + + + align:start position:0% +my research is actually based on the +idea of thinking about a binary system + + align:start position:0% +idea of thinking about a binary system + + + align:start position:0% +idea of thinking about a binary system +as being one member of being a black + + align:start position:0% +as being one member of being a black + + + align:start position:0% +as being one member of being a black +hole and its companion being a particle + + align:start position:0% +hole and its companion being a particle + + + align:start position:0% +hole and its companion being a particle +like object it's it's a particularly + + align:start position:0% +like object it's it's a particularly + + + align:start position:0% +like object it's it's a particularly +limit of at a part of like object that + + align:start position:0% +limit of at a part of like object that + + + align:start position:0% +limit of at a part of like object that +orbits it so a really simple stress + + align:start position:0% +orbits it so a really simple stress + + + align:start position:0% +orbits it so a really simple stress +energy tensor and I'm just throwing it + + align:start position:0% +energy tensor and I'm just throwing it + + + align:start position:0% +energy tensor and I'm just throwing it +out here because I think it nicely + + align:start position:0% +out here because I think it nicely + + + align:start position:0% +out here because I think it nicely +illustrates the principle a point + + align:start position:0% +illustrates the principle a point + + + align:start position:0% +illustrates the principle a point +particle with rest mass we'll call it m0 + + align:start position:0% + + + + align:start position:0% + +and I'm gonna say it's moving on a + + align:start position:0% +and I'm gonna say it's moving on a + + + align:start position:0% +and I'm gonna say it's moving on a +particular world line through space-time + + align:start position:0% + + + + align:start position:0% + +so the way we define a world line is we + + align:start position:0% +so the way we define a world line is we + + + align:start position:0% +so the way we define a world line is we +just say it's some four-vector that + + align:start position:0% +just say it's some four-vector that + + + align:start position:0% +just say it's some four-vector that +describes there's a place in this thing + + align:start position:0% +describes there's a place in this thing + + + align:start position:0% +describes there's a place in this thing +from some chosen origin and it's + + align:start position:0% +from some chosen origin and it's + + + align:start position:0% +from some chosen origin and it's +generally most convenient to + + align:start position:0% +generally most convenient to + + + align:start position:0% +generally most convenient to +parameterize it by the proper time of + + align:start position:0% +parameterize it by the proper time of + + + align:start position:0% +parameterize it by the proper time of +whatever object or creature is moving on + + align:start position:0% +whatever object or creature is moving on + + + align:start position:0% +whatever object or creature is moving on +that world line and so it's a lot like + + align:start position:0% +that world line and so it's a lot like + + + align:start position:0% +that world line and so it's a lot like +dust only there's no volume right it's + + align:start position:0% +dust only there's no volume right it's + + + align:start position:0% +dust only there's no volume right it's +sort of like one particle of dust and so + + align:start position:0% +sort of like one particle of dust and so + + + align:start position:0% +sort of like one particle of dust and so +the stress energy tensor we use for this + + align:start position:0% + + + + align:start position:0% + +we back up for just a second here when + + align:start position:0% +we back up for just a second here when + + + align:start position:0% +we back up for just a second here when +you guys learned about electricity and + + align:start position:0% +you guys learned about electricity and + + + align:start position:0% +you guys learned about electricity and +magnetism okay for the first thing you + + align:start position:0% +magnetism okay for the first thing you + + + align:start position:0% +magnetism okay for the first thing you +learn about our point charges and then a + + align:start position:0% +learn about our point charges and then a + + + align:start position:0% +learn about our point charges and then a +little bit later you learn about charge + + align:start position:0% +little bit later you learn about charge + + + align:start position:0% +little bit later you learn about charge +distributions and you have charge + + align:start position:0% +distributions and you have charge + + + align:start position:0% +distributions and you have charge +densities okay and then usually at some + + align:start position:0% +densities okay and then usually at some + + + align:start position:0% +densities okay and then usually at some +point in a class it's often like junior + + align:start position:0% +point in a class it's often like junior + + + align:start position:0% +point in a class it's often like junior +level enm we say how do you describe the + + align:start position:0% +level enm we say how do you describe the + + + align:start position:0% +level enm we say how do you describe the +density of a point charge that's where + + align:start position:0% +density of a point charge that's where + + + align:start position:0% +density of a point charge that's where +you learn about the Dirac Delta function + + align:start position:0% +you learn about the Dirac Delta function + + + align:start position:0% +you learn about the Dirac Delta function +well if I have a point particle I'm + + align:start position:0% +well if I have a point particle I'm + + + align:start position:0% +well if I have a point particle I'm +going to need to describe this thing's + + align:start position:0% +going to need to describe this thing's + + + align:start position:0% +going to need to describe this thing's +energy density as essentially a Dirac + + align:start position:0% +energy density as essentially a Dirac + + + align:start position:0% +energy density as essentially a Dirac +Delta function and so what we do is + + align:start position:0% + + + + align:start position:0% + +imagining that these things so this is + + align:start position:0% +imagining that these things so this is + + + align:start position:0% +imagining that these things so this is +the four velocity of that body they + + align:start position:0% +the four velocity of that body they + + + align:start position:0% +the four velocity of that body they +might be functions of time as this guy + + align:start position:0% +might be functions of time as this guy + + + align:start position:0% +might be functions of time as this guy +is moving along here what we do is we + + align:start position:0% +is moving along here what we do is we + + + align:start position:0% +is moving along here what we do is we +introduce a Dirac Delta function as this + + align:start position:0% +introduce a Dirac Delta function as this + + + align:start position:0% +introduce a Dirac Delta function as this +thing moves along through space time + + align:start position:0% +thing moves along through space time + + + align:start position:0% +thing moves along through space time +what this does you can check the + + align:start position:0% +what this does you can check the + + + align:start position:0% +what this does you can check the +dimensions this gives me exactly what we + + align:start position:0% +dimensions this gives me exactly what we + + + align:start position:0% +dimensions this gives me exactly what we +need in order to have something that's + + align:start position:0% +need in order to have something that's + + + align:start position:0% +need in order to have something that's +dimensionally correct and has all the + + align:start position:0% +dimensionally correct and has all the + + + align:start position:0% +dimensionally correct and has all the +symmetries and all the properties that + + align:start position:0% +symmetries and all the properties that + + + align:start position:0% +symmetries and all the properties that +describe a particle moving at the + + align:start position:0% +describe a particle moving at the + + + align:start position:0% +describe a particle moving at the +particular floor velocity through + + align:start position:0% +particular floor velocity through + + + align:start position:0% +particular floor velocity through +space-time now you might want to just + + align:start position:0% +space-time now you might want to just + + + align:start position:0% +space-time now you might want to just +it's the thing which I kind of want to + + align:start position:0% +it's the thing which I kind of want to + + + align:start position:0% +it's the thing which I kind of want to +pause on for a second you go the hell + + align:start position:0% +pause on for a second you go the hell + + + align:start position:0% +pause on for a second you go the hell +you do with this right well the trick we + + align:start position:0% +you do with this right well the trick we + + + align:start position:0% +you do with this right well the trick we +use to sort of clean up that Dirac Delta + + align:start position:0% +use to sort of clean up that Dirac Delta + + + align:start position:0% +use to sort of clean up that Dirac Delta +function is it's very much like what you + + align:start position:0% +function is it's very much like what you + + + align:start position:0% +function is it's very much like what you +do when you encounter a + + align:start position:0% +do when you encounter a + + + align:start position:0% +do when you encounter a +multi-dimensional Delta functions in + + align:start position:0% +multi-dimensional Delta functions in + + + align:start position:0% +multi-dimensional Delta functions in +basic physics you just build it out of a + + align:start position:0% +basic physics you just build it out of a + + + align:start position:0% +basic physics you just build it out of a +bunch of one-dimensional Delta functions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +likewise you let a turn with the Y + + align:start position:0% +likewise you let a turn with the Y + + + align:start position:0% +likewise you let a turn with the Y +component and the Z component then you + + align:start position:0% +component and the Z component then you + + + align:start position:0% +component and the Z component then you +use the rule then if I integrate a + + align:start position:0% +use the rule then if I integrate a + + + align:start position:0% +use the rule then if I integrate a +function of X against a delta function + + align:start position:0% + + + + align:start position:0% + +whose argument is itself a function of X + + align:start position:0% +whose argument is itself a function of X + + + align:start position:0% +whose argument is itself a function of X +I evaluate that function at the zeros of + + align:start position:0% +I evaluate that function at the zeros of + + + align:start position:0% +I evaluate that function at the zeros of +G so let's say x0 is where G has a zero + + align:start position:0% +G so let's say x0 is where G has a zero + + + align:start position:0% +G so let's say x0 is where G has a zero +normalizing to the first derivative of G + + align:start position:0% +normalizing to the first derivative of G + + + align:start position:0% +normalizing to the first derivative of G +evaluated at that zero + + align:start position:0% + + + + align:start position:0% + +when you put all of that together + + align:start position:0% +when you put all of that together + + + align:start position:0% +when you put all of that together +it basically means you can do this + + align:start position:0% +it basically means you can do this + + + align:start position:0% +it basically means you can do this +somewhat abstract integral formally I + + align:start position:0% +somewhat abstract integral formally I + + + align:start position:0% +somewhat abstract integral formally I +mean exactly you can just do it + + align:start position:0% +mean exactly you can just do it + + + align:start position:0% +mean exactly you can just do it +analytically and what you do just you + + align:start position:0% +analytically and what you do just you + + + align:start position:0% +analytically and what you do just you +choose one of the Delta functions to + + align:start position:0% +choose one of the Delta functions to + + + align:start position:0% +choose one of the Delta functions to +apply it to traditionally people apply + + align:start position:0% +apply it to traditionally people apply + + + align:start position:0% +apply it to traditionally people apply +it to the time light component and what + + align:start position:0% +it to the time light component and what + + + align:start position:0% +it to the time light component and what +is the derivative of the world line Z + + align:start position:0% +is the derivative of the world line Z + + + align:start position:0% +is the derivative of the world line Z +component with respect to proper time + + align:start position:0% +component with respect to proper time + + + align:start position:0% +component with respect to proper time +it's the zero complement of the for + + align:start position:0% +it's the zero complement of the for + + + align:start position:0% +it's the zero complement of the for +velocity so you just divide by zero + + align:start position:0% +velocity so you just divide by zero + + + align:start position:0% +velocity so you just divide by zero +content of the floor velocity and then + + align:start position:0% +content of the floor velocity and then + + + align:start position:0% +content of the floor velocity and then +you're left with a three dimensional + + align:start position:0% +you're left with a three dimensional + + + align:start position:0% +you're left with a three dimensional +Delta function for the spatial + + align:start position:0% +Delta function for the spatial + + + align:start position:0% +Delta function for the spatial +trajectory of this thing through all + + align:start position:0% +trajectory of this thing through all + + + align:start position:0% +trajectory of this thing through all +space so it's an example of one that + + align:start position:0% +space so it's an example of one that + + + align:start position:0% +space so it's an example of one that +just again kind of the intuition is one + + align:start position:0% +just again kind of the intuition is one + + + align:start position:0% +just again kind of the intuition is one +things I want to emphasize notice we had + + align:start position:0% +things I want to emphasize notice we had + + + align:start position:0% +things I want to emphasize notice we had +this hat it's the symmetries that we + + align:start position:0% +this hat it's the symmetries that we + + + align:start position:0% +this hat it's the symmetries that we +want it to have it's not hard to show + + align:start position:0% +want it to have it's not hard to show + + + align:start position:0% +want it to have it's not hard to show +that this you can think of this as + + align:start position:0% +that this you can think of this as + + + align:start position:0% +that this you can think of this as +essentially being kinda like a gamma + + align:start position:0% +essentially being kinda like a gamma + + + align:start position:0% +essentially being kinda like a gamma +factor this all ends up giving me just + + align:start position:0% +factor this all ends up giving me just + + + align:start position:0% +factor this all ends up giving me just +what we need for this thing to have the + + align:start position:0% +what we need for this thing to have the + + + align:start position:0% +what we need for this thing to have the +right transformation properties and so + + align:start position:0% +right transformation properties and so + + + align:start position:0% +right transformation properties and so +and it does in fact play a role in some + + align:start position:0% +and it does in fact play a role in some + + + align:start position:0% +and it does in fact play a role in some +I'll just say in some research that's + + align:start position:0% +I'll just say in some research that's + + + align:start position:0% +I'll just say in some research that's +near and dear to my heart let me do + + align:start position:0% +near and dear to my heart let me do + + + align:start position:0% +near and dear to my heart let me do +another example suppose you want to know + + align:start position:0% +another example suppose you want to know + + + align:start position:0% +another example suppose you want to know +the stress energy tensor associated with + + align:start position:0% +the stress energy tensor associated with + + + align:start position:0% +the stress energy tensor associated with +a given electric and magnetic field well + + align:start position:0% +a given electric and magnetic field well + + + align:start position:0% +a given electric and magnetic field well +first let me just quote for you the + + align:start position:0% +first let me just quote for you the + + + align:start position:0% +first let me just quote for you the +exact answer which is most compactly + + align:start position:0% +exact answer which is most compactly + + + align:start position:0% +exact answer which is most compactly +written if we use that Faraday tensor F + + align:start position:0% +written if we use that Faraday tensor F + + + align:start position:0% +written if we use that Faraday tensor F +which describes Electric magnetic fields + + align:start position:0% +which describes Electric magnetic fields + + + align:start position:0% +which describes Electric magnetic fields +in a frame independent fashion the way + + align:start position:0% +in a frame independent fashion the way + + + align:start position:0% +in a frame independent fashion the way +that I introduced it in the last lecture + + align:start position:0% +that I introduced it in the last lecture + + + align:start position:0% +that I introduced it in the last lecture +so in units where basically everything + + align:start position:0% +so in units where basically everything + + + align:start position:0% +so in units where basically everything +but pi is set equal to one + + align:start position:0% + + + + align:start position:0% + +it ends up turning into this okay so + + align:start position:0% +it ends up turning into this okay so + + + align:start position:0% +it ends up turning into this okay so +that's a bit of a mouthful let's go in + + align:start position:0% +that's a bit of a mouthful let's go in + + + align:start position:0% +that's a bit of a mouthful let's go in +and look at particular components of it + + align:start position:0% +and look at particular components of it + + + align:start position:0% +and look at particular components of it +though okay so let's say I go into a + + align:start position:0% +though okay so let's say I go into a + + + align:start position:0% +though okay so let's say I go into a +particular frame I fill in my Faraday + + align:start position:0% +particular frame I fill in my Faraday + + + align:start position:0% +particular frame I fill in my Faraday +tensor with the form of the electric + + align:start position:0% +tensor with the form of the electric + + + align:start position:0% +tensor with the form of the electric +magnetic field that I introduced last + + align:start position:0% +magnetic field that I introduced last + + + align:start position:0% +magnetic field that I introduced last +time and I'll just go through and I'll + + align:start position:0% +time and I'll just go through and I'll + + + align:start position:0% +time and I'll just go through and I'll +evaluate all the different components of + + align:start position:0% +evaluate all the different components of + + + align:start position:0% +evaluate all the different components of +this thing so what you find when you + + align:start position:0% +this thing so what you find when you + + + align:start position:0% +this thing so what you find when you +fill this in is your T zero zero + + align:start position:0% +fill this in is your T zero zero + + + align:start position:0% +fill this in is your T zero zero +component 1 over 8 pi e squared plus B + + align:start position:0% +component 1 over 8 pi e squared plus B + + + align:start position:0% +component 1 over 8 pi e squared plus B +squared okay that's good okay hopefully + + align:start position:0% +squared okay that's good okay hopefully + + + align:start position:0% +squared okay that's good okay hopefully +you all remember from basic E&M the + + align:start position:0% +you all remember from basic E&M the + + + align:start position:0% +you all remember from basic E&M the +energy density of an e field is e + + align:start position:0% +energy density of an e field is e + + + align:start position:0% +energy density of an e field is e +squared over 8 pi from the right system + + align:start position:0% +squared over 8 pi from the right system + + + align:start position:0% +squared over 8 pi from the right system +of units energy dance with a B field is + + align:start position:0% +of units energy dance with a B field is + + + align:start position:0% +of units energy dance with a B field is +B squared over 8 pi if you work in + + align:start position:0% +B squared over 8 pi if you work in + + + align:start position:0% +B squared over 8 pi if you work in +gaad's units let's do the time-space + + align:start position:0% +gaad's units let's do the time-space + + + align:start position:0% +gaad's units let's do the time-space +component so again hack through that + + align:start position:0% +component so again hack through that + + + align:start position:0% +component so again hack through that +mess there this is going to be something + + align:start position:0% +mess there this is going to be something + + + align:start position:0% +mess there this is going to be something +that is a vector + + align:start position:0% + + + + align:start position:0% + +in fact it's the pointing vector okay + + align:start position:0% +in fact it's the pointing vector okay + + + align:start position:0% +in fact it's the pointing vector okay +could it be anything else if you use the + + align:start position:0% +could it be anything else if you use the + + + align:start position:0% +could it be anything else if you use the +recipe that I sort of suggested is the + + align:start position:0% +recipe that I sort of suggested is the + + + align:start position:0% +recipe that I sort of suggested is the +you know the easiest way to approach + + align:start position:0% +you know the easiest way to approach + + + align:start position:0% +you know the easiest way to approach +this this is kind of what you would have + + align:start position:0% +this this is kind of what you would have + + + align:start position:0% +this this is kind of what you would have +guessed for something like that the bit + + align:start position:0% +guessed for something like that the bit + + + align:start position:0% +guessed for something like that the bit +that's actually kind of hard is then + + align:start position:0% +that's actually kind of hard is then + + + align:start position:0% +that's actually kind of hard is then +trying to get the spatial stresses of + + align:start position:0% +trying to get the spatial stresses of + + + align:start position:0% +trying to get the spatial stresses of +this thing and here I don't have any + + align:start position:0% +this thing and here I don't have any + + + align:start position:0% +this thing and here I don't have any +great intuition for this one to convey + + align:start position:0% +great intuition for this one to convey + + + align:start position:0% +great intuition for this one to convey +to you it's derived in textbooks like + + align:start position:0% +to you it's derived in textbooks like + + + align:start position:0% +to you it's derived in textbooks like +Griffiths and Jackson so I'll just quote + + align:start position:0% +Griffiths and Jackson so I'll just quote + + + align:start position:0% +Griffiths and Jackson so I'll just quote +for you the result so you get one term + + align:start position:0% +for you the result so you get one term + + + align:start position:0% +for you the result so you get one term +it looks like a squared plus B squared + + align:start position:0% +it looks like a squared plus B squared + + + align:start position:0% +it looks like a squared plus B squared +on the diagonals then there's a + + align:start position:0% +on the diagonals then there's a + + + align:start position:0% +on the diagonals then there's a +correction which looks like this I want + + align:start position:0% +correction which looks like this I want + + + align:start position:0% +correction which looks like this I want +to just quickly call out one example so + + align:start position:0% +to just quickly call out one example so + + + align:start position:0% +to just quickly call out one example so +you can see what the significance of + + align:start position:0% +you can see what the significance of + + + align:start position:0% +you can see what the significance of +this example is so suppose you have + + align:start position:0% +this example is so suppose you have + + + align:start position:0% +this example is so suppose you have +something like a pair of capacitors + + align:start position:0% +something like a pair of capacitors + + + align:start position:0% +something like a pair of capacitors +right and there's just a uniform + + align:start position:0% +right and there's just a uniform + + + align:start position:0% +right and there's just a uniform +electric field between them you want to + + align:start position:0% +electric field between them you want to + + + align:start position:0% +electric field between them you want to +evaluate the stress energy tensor + + align:start position:0% +evaluate the stress energy tensor + + + align:start position:0% +evaluate the stress energy tensor +between those pairs of capacitors so my + + align:start position:0% +between those pairs of capacitors so my + + + align:start position:0% +between those pairs of capacitors so my +spatial electric field let's say it just + + align:start position:0% +spatial electric field let's say it just + + + align:start position:0% +spatial electric field let's say it just +points in the x-direction and it's + + align:start position:0% +points in the x-direction and it's + + + align:start position:0% +points in the x-direction and it's +constant + + align:start position:0% + + + + align:start position:0% + +so when you actually evaluate this guy + + align:start position:0% +so when you actually evaluate this guy + + + align:start position:0% +so when you actually evaluate this guy +there's no energy flow there's no + + align:start position:0% +there's no energy flow there's no + + + align:start position:0% +there's no energy flow there's no +magnetic field so there's no pointing + + align:start position:0% +magnetic field so there's no pointing + + + align:start position:0% +magnetic field so there's no pointing +factor you of course have a squared over + + align:start position:0% +factor you of course have a squared over + + + align:start position:0% +factor you of course have a squared over +8 pi for your energy density okay + + align:start position:0% +8 pi for your energy density okay + + + align:start position:0% +8 pi for your energy density okay +very different from a perfect fluid okay + + align:start position:0% +very different from a perfect fluid okay + + + align:start position:0% +very different from a perfect fluid okay +and this kind of makes sense that's sort + + align:start position:0% +and this kind of makes sense that's sort + + + align:start position:0% +and this kind of makes sense that's sort +of telling you that there is a stress + + align:start position:0% +of telling you that there is a stress + + + align:start position:0% +of telling you that there is a stress +that you know if you have a pair of + + align:start position:0% +that you know if you have a pair of + + + align:start position:0% +that you know if you have a pair of +plain parallel capacitors you tend to + + align:start position:0% +plain parallel capacitors you tend to + + + align:start position:0% +plain parallel capacitors you tend to +attract the plates to each other right + + align:start position:0% +attract the plates to each other right + + + align:start position:0% +attract the plates to each other right +but there's a pressure associate that + + align:start position:0% +but there's a pressure associate that + + + align:start position:0% +but there's a pressure associate that +electric field it actually goes in the + + align:start position:0% +electric field it actually goes in the + + + align:start position:0% +electric field it actually goes in the +other directions okay this is your X + + align:start position:0% +other directions okay this is your X + + + align:start position:0% +other directions okay this is your X +Direction this is y and z and as a + + align:start position:0% +Direction this is y and z and as a + + + align:start position:0% +Direction this is y and z and as a +consequence of this so there's some + + align:start position:0% +consequence of this so there's some + + + align:start position:0% +consequence of this so there's some +stuff which we're not going to do too + + align:start position:0% +stuff which we're not going to do too + + + align:start position:0% +stuff which we're not going to do too +much with in this class but I may give + + align:start position:0% +much with in this class but I may give + + + align:start position:0% +much with in this class but I may give +you some pointers on this electric and + + align:start position:0% +you some pointers on this electric and + + + align:start position:0% +you some pointers on this electric and +magnetic fields generates they generate + + align:start position:0% +magnetic fields generates they generate + + + align:start position:0% +magnetic fields generates they generate +pressures at least in certain directions + + align:start position:0% +pressures at least in certain directions + + + align:start position:0% +pressures at least in certain directions +they kind of generate like an + + align:start position:0% +they kind of generate like an + + + align:start position:0% +they kind of generate like an +anisotropic pressure ah and when we + + align:start position:0% +anisotropic pressure ah and when we + + + align:start position:0% +anisotropic pressure ah and when we +start coupling this to gravity you can + + align:start position:0% +start coupling this to gravity you can + + + align:start position:0% +start coupling this to gravity you can +get electric fields and magnetic fields + + align:start position:0% +get electric fields and magnetic fields + + + align:start position:0% +get electric fields and magnetic fields +that contribute non negligibly to the + + align:start position:0% +that contribute non negligibly to the + + + align:start position:0% +that contribute non negligibly to the +gravity of their object that is it for + + align:start position:0% +gravity of their object that is it for + + + align:start position:0% +gravity of their object that is it for +the stress energy tensor as I said we + + align:start position:0% +the stress energy tensor as I said we + + + align:start position:0% +the stress energy tensor as I said we +are going to use this guy over and over + + align:start position:0% +are going to use this guy over and over + + + align:start position:0% +are going to use this guy over and over +and over again and the reason for this + + align:start position:0% +and over again and the reason for this + + + align:start position:0% +and over again and the reason for this +does come back to that little motivation + + align:start position:0% +does come back to that little motivation + + + align:start position:0% +does come back to that little motivation +that I gave probably about 45 minutes + + align:start position:0% +that I gave probably about 45 minutes + + + align:start position:0% +that I gave probably about 45 minutes +ago where we sort of looked at the + + align:start position:0% +ago where we sort of looked at the + + + align:start position:0% +ago where we sort of looked at the +Newtonian field equation and instead + + align:start position:0% +Newtonian field equation and instead + + + align:start position:0% +Newtonian field equation and instead +picking out a particular scalar as the + + align:start position:0% +picking out a particular scalar as the + + + align:start position:0% +picking out a particular scalar as the +source of gravity makes no sense in a + + align:start position:0% +source of gravity makes no sense in a + + + align:start position:0% +source of gravity makes no sense in a +relativistic covariant Theory it's got + + align:start position:0% +relativistic covariant Theory it's got + + + align:start position:0% +relativistic covariant Theory it's got +to be the whole tensor and indeed this + + align:start position:0% +to be the whole tensor and indeed this + + + align:start position:0% +to be the whole tensor and indeed this +is the one well not actually the enm one + + align:start position:0% +is the one well not actually the enm one + + + align:start position:0% +is the one well not actually the enm one +but the general notion of a stress + + align:start position:0% +but the general notion of a stress + + + align:start position:0% +but the general notion of a stress +energy tensor is the one that we are + + align:start position:0% +energy tensor is the one that we are + + + align:start position:0% +energy tensor is the one that we are +going to use for that so we have about + + align:start position:0% + + + + align:start position:0% + +10 minutes left and so I would like to + + align:start position:0% +10 minutes left and so I would like to + + + align:start position:0% +10 minutes left and so I would like to +start the process of switching gears + + align:start position:0% +start the process of switching gears + + + align:start position:0% +start the process of switching gears +before I do that are there any questions + + align:start position:0% + + + + align:start position:0% + +all right I will clean the board + + align:start position:0% + + + + align:start position:0% + +so the reason we are switching gears is + + align:start position:0% +so the reason we are switching gears is + + + align:start position:0% +so the reason we are switching gears is +we now have probably the most important + + align:start position:0% +we now have probably the most important + + + align:start position:0% +we now have probably the most important +physical tools that we need in order to + + align:start position:0% +physical tools that we need in order to + + + align:start position:0% +physical tools that we need in order to +start thinking about making a + + align:start position:0% +start thinking about making a + + + align:start position:0% +start thinking about making a +relativistic theory of gravity but we + + align:start position:0% +relativistic theory of gravity but we + + + align:start position:0% +relativistic theory of gravity but we +need a few more mathematical tools in + + align:start position:0% +need a few more mathematical tools in + + + align:start position:0% +need a few more mathematical tools in +particular I'm going to argue in a + + align:start position:0% +particular I'm going to argue in a + + + align:start position:0% +particular I'm going to argue in a +couple of lectures that flat space-time + + align:start position:0% +couple of lectures that flat space-time + + + align:start position:0% +couple of lectures that flat space-time +is not sufficient for us to build a + + align:start position:0% +is not sufficient for us to build a + + + align:start position:0% +is not sufficient for us to build a +theory of gravity we're going to need to + + align:start position:0% +theory of gravity we're going to need to + + + align:start position:0% +theory of gravity we're going to need to +firstly you have to understand what that + + align:start position:0% +firstly you have to understand what that + + + align:start position:0% +firstly you have to understand what that +means and we're not quite ready to go + + align:start position:0% +means and we're not quite ready to go + + + align:start position:0% +means and we're not quite ready to go +there so for now it's just fancy words + + align:start position:0% +there so for now it's just fancy words + + + align:start position:0% +there so for now it's just fancy words +but I'm gonna have to introduce some + + align:start position:0% +but I'm gonna have to introduce some + + + align:start position:0% +but I'm gonna have to introduce some +kind of a notion of curvature into + + align:start position:0% +kind of a notion of curvature into + + + align:start position:0% +kind of a notion of curvature into +things okay what does that even mean + + align:start position:0% +things okay what does that even mean + + + align:start position:0% +things okay what does that even mean +really we need to have the tools to do + + align:start position:0% +really we need to have the tools to do + + + align:start position:0% +really we need to have the tools to do +that and so as a prelude to going in + + align:start position:0% +that and so as a prelude to going in + + + align:start position:0% +that and so as a prelude to going in +that direction I will call this my frail + + align:start position:0% +that direction I will call this my frail + + + align:start position:0% +that direction I will call this my frail +OODA curvature what we're going to start + + align:start position:0% +OODA curvature what we're going to start + + + align:start position:0% +OODA curvature what we're going to start +doing is flat space-time in curvilinear + + align:start position:0% +doing is flat space-time in curvilinear + + + align:start position:0% +doing is flat space-time in curvilinear +coordinates and the importance of doing + + align:start position:0% +coordinates and the importance of doing + + + align:start position:0% +coordinates and the importance of doing +this why this is going to be useful to + + align:start position:0% +this why this is going to be useful to + + + align:start position:0% +this why this is going to be useful to +us is that it will introduce a so it'll + + align:start position:0% +us is that it will introduce a so it'll + + + align:start position:0% +us is that it will introduce a so it'll +keep the physics simple it's still gonna + + align:start position:0% +keep the physics simple it's still gonna + + + align:start position:0% +keep the physics simple it's still gonna +be special relativity but it's now going + + align:start position:0% +be special relativity but it's now going + + + align:start position:0% +be special relativity but it's now going +to be special relativity using a + + align:start position:0% +to be special relativity using a + + + align:start position:0% +to be special relativity using a +mathematical structure in which the + + align:start position:0% +mathematical structure in which the + + + align:start position:0% +mathematical structure in which the +basis vectors are no longer constant + + align:start position:0% +basis vectors are no longer constant + + + align:start position:0% +basis vectors are no longer constant +okay so that's going to allow us to + + align:start position:0% +okay so that's going to allow us to + + + align:start position:0% +okay so that's going to allow us to +begin making a couple of mathematical + + align:start position:0% +begin making a couple of mathematical + + + align:start position:0% +begin making a couple of mathematical +tools that are necessary to build + + align:start position:0% +tools that are necessary to build + + + align:start position:0% +tools that are necessary to build +gravity into this theory so we'll start + + align:start position:0% +gravity into this theory so we'll start + + + align:start position:0% +gravity into this theory so we'll start +by replacing this with just simple plain + + align:start position:0% +by replacing this with just simple plain + + + align:start position:0% +by replacing this with just simple plain +polar coordinates okay + + align:start position:0% +polar coordinates okay + + + align:start position:0% +polar coordinates okay +mapped in the usual way so if you want + + align:start position:0% +mapped in the usual way so if you want + + + align:start position:0% +mapped in the usual way so if you want +to go back and forth well at least one + + align:start position:0% +to go back and forth well at least one + + + align:start position:0% +to go back and forth well at least one +way transformation + + align:start position:0% +way transformation + + + align:start position:0% +way transformation +I build X&Y from R and Phi in that usual + + align:start position:0% +I build X&Y from R and Phi in that usual + + + align:start position:0% +I build X&Y from R and Phi in that usual +way there's an inverse mapping as well + + align:start position:0% +way there's an inverse mapping as well + + + align:start position:0% +way there's an inverse mapping as well +which involves trig functions so I'm not + + align:start position:0% +which involves trig functions so I'm not + + + align:start position:0% +which involves trig functions so I'm not +going to write it down one point which I + + align:start position:0% +going to write it down one point which I + + + align:start position:0% +going to write it down one point which I +really want to emphasize here is we are + + align:start position:0% +really want to emphasize here is we are + + + align:start position:0% +really want to emphasize here is we are +going to continue to use a coordinate + + align:start position:0% +going to continue to use a coordinate + + + align:start position:0% +going to continue to use a coordinate +basis and we remind you what that means + + align:start position:0% + + + + align:start position:0% + +so a coordinate basis means that the + + align:start position:0% +so a coordinate basis means that the + + + align:start position:0% +so a coordinate basis means that the +differential displacement vector from an + + align:start position:0% +differential displacement vector from an + + + align:start position:0% +differential displacement vector from an +event a to a nearby event B is simply + + align:start position:0% +event a to a nearby event B is simply + + + align:start position:0% +event a to a nearby event B is simply +related by differentials of my + + align:start position:0% +related by differentials of my + + + align:start position:0% +related by differentials of my +coordinate contracted on to my basis + + align:start position:0% +coordinate contracted on to my basis + + + align:start position:0% +coordinate contracted on to my basis +factors but when I'm working in a + + align:start position:0% +factors but when I'm working in a + + + align:start position:0% +factors but when I'm working in a +curvilinear coordinate system like this + + align:start position:0% + + + + align:start position:0% + +that means one of them has a somewhat + + align:start position:0% +that means one of them has a somewhat + + + align:start position:0% +that means one of them has a somewhat +different form from what you were used + + align:start position:0% +different form from what you were used + + + align:start position:0% +different form from what you were used +to okay when you guys talk about the + + align:start position:0% +to okay when you guys talk about the + + + align:start position:0% +to okay when you guys talk about the +differential of a displacement and just + + align:start position:0% +differential of a displacement and just + + + align:start position:0% +differential of a displacement and just +about every physics class up till now if + + align:start position:0% +about every physics class up till now if + + + align:start position:0% +about every physics class up till now if +you have a differential angle you'd want + + align:start position:0% +you have a differential angle you'd want + + + align:start position:0% +you have a differential angle you'd want +to throw an R and E here so it just says + + align:start position:0% +to throw an R and E here so it just says + + + align:start position:0% +to throw an R and E here so it just says +the dimensions of length we ain't gonna + + align:start position:0% +the dimensions of length we ain't gonna + + + align:start position:0% +the dimensions of length we ain't gonna +do that okay and so what this means + + align:start position:0% +do that okay and so what this means + + + align:start position:0% +do that okay and so what this means +since this is an angle every component + + align:start position:0% +since this is an angle every component + + + align:start position:0% +since this is an angle every component +of this has the dimensions of length + + align:start position:0% + + + + align:start position:0% + +that means that my basis vector is going + + align:start position:0% +that means that my basis vector is going + + + align:start position:0% +that means that my basis vector is going +to be something that has the dimensions + + align:start position:0% +to be something that has the dimensions + + + align:start position:0% +to be something that has the dimensions +of length associated with it okay + + align:start position:0% +of length associated with it okay + + + align:start position:0% +of length associated with it okay +this in turn means that this is not + + align:start position:0% +this in turn means that this is not + + + align:start position:0% +this in turn means that this is not +going to be a normal basis okay that's + + align:start position:0% +going to be a normal basis okay that's + + + align:start position:0% +going to be a normal basis okay that's +unfortunately a somewhat loaded word + + align:start position:0% +unfortunately a somewhat loaded word + + + align:start position:0% +unfortunately a somewhat loaded word +what I mean by that is that it has not + + align:start position:0% +what I mean by that is that it has not + + + align:start position:0% +what I mean by that is that it has not +been normalized but given that you guys + + align:start position:0% +been normalized but given that you guys + + + align:start position:0% +been normalized but given that you guys +have spent all of your career thinking + + align:start position:0% +have spent all of your career thinking + + + align:start position:0% +have spent all of your career thinking +about the dot product of a unit vector + + align:start position:0% +about the dot product of a unit vector + + + align:start position:0% +about the dot product of a unit vector +with itself of a basis backed with + + align:start position:0% +with itself of a basis backed with + + + align:start position:0% +with itself of a basis backed with +itself equal to one the other meaning of + + align:start position:0% +itself equal to one the other meaning of + + + align:start position:0% +itself equal to one the other meaning of +normal might be good for you to the keep + + align:start position:0% +normal might be good for you to the keep + + + align:start position:0% +normal might be good for you to the keep +thing which I want to emphasize here is + + align:start position:0% +thing which I want to emphasize here is + + + align:start position:0% +thing which I want to emphasize here is +'if i dot e phi does not equal one + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +one other little bit of notation which I + + align:start position:0% +one other little bit of notation which I + + + align:start position:0% +one other little bit of notation which I +would like to introduce so we are going + + align:start position:0% +would like to introduce so we are going + + + align:start position:0% +would like to introduce so we are going +to want to talk about transformations + + align:start position:0% +to want to talk about transformations + + + align:start position:0% +to want to talk about transformations +between different representations okay + + align:start position:0% +between different representations okay + + + align:start position:0% +between different representations okay +we've done this so far we have generally + + align:start position:0% +we've done this so far we have generally + + + align:start position:0% +we've done this so far we have generally +focused on moving between different + + align:start position:0% +focused on moving between different + + + align:start position:0% +focused on moving between different +reference frames + + align:start position:0% +reference frames + + + align:start position:0% +reference frames +I want to generalize this notion and I'm + + align:start position:0% +I want to generalize this notion and I'm + + + align:start position:0% +I want to generalize this notion and I'm +going to tweak my notation a little bit + + align:start position:0% +going to tweak my notation a little bit + + + align:start position:0% +going to tweak my notation a little bit +to indicate the difference okay so I'm + + align:start position:0% +to indicate the difference okay so I'm + + + align:start position:0% +to indicate the difference okay so I'm +going to call capital L alpha mu bar see + + align:start position:0% +going to call capital L alpha mu bar see + + + align:start position:0% +going to call capital L alpha mu bar see +what I get when I just look at the + + align:start position:0% +what I get when I just look at the + + + align:start position:0% +what I get when I just look at the +variation of coordinate the Alpha + + align:start position:0% +variation of coordinate the Alpha + + + align:start position:0% +variation of coordinate the Alpha +coordinate system sorry the unbarred + + align:start position:0% +coordinate system sorry the unbarred + + + align:start position:0% +coordinate system sorry the unbarred +chord system with the barred one okay so + + align:start position:0% +chord system with the barred one okay so + + + align:start position:0% +chord system with the barred one okay so +this is just it's there's there's no + + align:start position:0% +this is just it's there's there's no + + + align:start position:0% +this is just it's there's there's no +deep things here I just want you to be + + align:start position:0% +deep things here I just want you to be + + + align:start position:0% +deep things here I just want you to be +familiar to notation which I'm going to + + align:start position:0% +familiar to notation which I'm going to + + + align:start position:0% +familiar to notation which I'm going to +use I will always reserve lambda for the + + align:start position:0% +use I will always reserve lambda for the + + + align:start position:0% +use I will always reserve lambda for the +Lorentz transformation okay so in the + + align:start position:0% +Lorentz transformation okay so in the + + + align:start position:0% +Lorentz transformation okay so in the +interest of time you know I'll just I'll + + align:start position:0% +interest of time you know I'll just I'll + + + align:start position:0% +interest of time you know I'll just I'll +write down one of these so this sort of + + align:start position:0% +write down one of these so this sort of + + + align:start position:0% +write down one of these so this sort of +means like for instance suppose that I'm + + align:start position:0% +means like for instance suppose that I'm + + + align:start position:0% +means like for instance suppose that I'm +transforming let's let bard indicate my + + align:start position:0% +transforming let's let bard indicate my + + + align:start position:0% +transforming let's let bard indicate my +polar coordinates unbarred the Cartesian + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so if I want to transform in one + + align:start position:0% +okay so if I want to transform in one + + + align:start position:0% +okay so if I want to transform in one +direction between my bar to my unbarred + + align:start position:0% +direction between my bar to my unbarred + + + align:start position:0% +direction between my bar to my unbarred +ones this matrix will go through it and + + align:start position:0% +ones this matrix will go through it and + + + align:start position:0% +ones this matrix will go through it and +it looks like this so this is the thing + + align:start position:0% +it looks like this so this is the thing + + + align:start position:0% +it looks like this so this is the thing +which I will call L alpha mu bar okay in + + align:start position:0% +which I will call L alpha mu bar okay in + + + align:start position:0% +which I will call L alpha mu bar okay in +my notes I also give the inverse + + align:start position:0% +my notes I also give the inverse + + + align:start position:0% +my notes I also give the inverse +transmission and I will actually write I + + align:start position:0% +transmission and I will actually write I + + + align:start position:0% +transmission and I will actually write I +have a minute I will write that one down + + align:start position:0% +have a minute I will write that one down + + + align:start position:0% +have a minute I will write that one down +as well the other direction it's just + + align:start position:0% +as well the other direction it's just + + + align:start position:0% +as well the other direction it's just +the matrix that inverts this + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +and the reason I started to take the + + align:start position:0% +and the reason I started to take the + + + align:start position:0% +and the reason I started to take the +extra 30 seconds or so to write this + + align:start position:0% +extra 30 seconds or so to write this + + + align:start position:0% +extra 30 seconds or so to write this +down is I'm going to call out the fact + + align:start position:0% +down is I'm going to call out the fact + + + align:start position:0% +down is I'm going to call out the fact +that in this kind of a transformation + + align:start position:0% +that in this kind of a transformation + + + align:start position:0% +that in this kind of a transformation +because of the fact that this is a + + align:start position:0% +because of the fact that this is a + + + align:start position:0% +because of the fact that this is a +coordinate basis that has this somewhat + + align:start position:0% +coordinate basis that has this somewhat + + + align:start position:0% +coordinate basis that has this somewhat +unusual property different elements of + + align:start position:0% +unusual property different elements of + + + align:start position:0% +unusual property different elements of +the matrix have different dimensions + + align:start position:0% +the matrix have different dimensions + + + align:start position:0% +the matrix have different dimensions +okay + + align:start position:0% +okay + + + align:start position:0% +okay +the feature not a bug okay so this is + + align:start position:0% +the feature not a bug okay so this is + + + align:start position:0% +the feature not a bug okay so this is +going to show up I'm gonna do a couple + + align:start position:0% +going to show up I'm gonna do a couple + + + align:start position:0% +going to show up I'm gonna do a couple +more calculations with this a little bit + + align:start position:0% +more calculations with this a little bit + + + align:start position:0% +more calculations with this a little bit +tomorrow + + align:start position:0% +tomorrow + + + align:start position:0% +tomorrow +sorry not tomorrow on Tuesday this is + + align:start position:0% +sorry not tomorrow on Tuesday this is + + + align:start position:0% +sorry not tomorrow on Tuesday this is +gonna show up in the way the metric + + align:start position:0% +gonna show up in the way the metric + + + align:start position:0% +gonna show up in the way the metric +looks okay the metric is gonna have a + + align:start position:0% +looks okay the metric is gonna have a + + + align:start position:0% +looks okay the metric is gonna have a +very different character in this + + align:start position:0% +very different character in this + + + align:start position:0% +very different character in this +coordinate system and we're going to see + + align:start position:0% +coordinate system and we're going to see + + + align:start position:0% +coordinate system and we're going to see +the way in which it basically boils down + + align:start position:0% +the way in which it basically boils down + + + align:start position:0% +the way in which it basically boils down +to is it's gonna pick up a non-trivial + + align:start position:0% +to is it's gonna pick up a non-trivial + + + align:start position:0% +to is it's gonna pick up a non-trivial +functional form it's not going to just + + align:start position:0% +functional form it's not going to just + + + align:start position:0% +functional form it's not going to just +be a constant and that fundamentally + + align:start position:0% +be a constant and that fundamentally + + + align:start position:0% +be a constant and that fundamentally +reflects the fact that the basis vectors + + align:start position:0% +reflects the fact that the basis vectors + + + align:start position:0% +reflects the fact that the basis vectors +are not constant anymore + + align:start position:0% +are not constant anymore + + + align:start position:0% +are not constant anymore +okay we'll end it there \ No newline at end of file diff --git a/OZxzHcW663g.txt b/OZxzHcW663g.txt new file mode 100644 index 0000000000000000000000000000000000000000..525cdb037e379492fcbbe41d72d18f1a1f1b2e73 --- /dev/null +++ b/OZxzHcW663g.txt @@ -0,0 +1,883 @@ +align:start position:0% + +welcome today's problem was actually + + align:start position:0% +welcome today's problem was actually + + + align:start position:0% +welcome today's problem was actually +appeared at in a quiz it appeared in + + align:start position:0% +appeared at in a quiz it appeared in + + + align:start position:0% +appeared at in a quiz it appeared in +quiz 1 + + align:start position:0% +quiz 1 + + + align:start position:0% +quiz 1 +in fall of 1999 as question for the + + align:start position:0% +in fall of 1999 as question for the + + + align:start position:0% +in fall of 1999 as question for the +problem it puts the usual solve the + + align:start position:0% +problem it puts the usual solve the + + + align:start position:0% +problem it puts the usual solve the +following system upside down by saying + + align:start position:0% +following system upside down by saying + + + align:start position:0% +following system upside down by saying +we have some matrix and we know that all + + align:start position:0% +we have some matrix and we know that all + + + align:start position:0% +we have some matrix and we know that all +the solutions to ax equals this vector + + align:start position:0% +the solutions to ax equals this vector + + + align:start position:0% +the solutions to ax equals this vector +here 1 4 1 1 all the solutions to this + + align:start position:0% +here 1 4 1 1 all the solutions to this + + + align:start position:0% +here 1 4 1 1 all the solutions to this +problem are given by x equals 0 1 1 plus + + align:start position:0% +problem are given by x equals 0 1 1 plus + + + align:start position:0% +problem are given by x equals 0 1 1 plus +any number C times 0 to 1 and we're + + align:start position:0% +any number C times 0 to 1 and we're + + + align:start position:0% +any number C times 0 to 1 and we're +asked to say everything that we can + + align:start position:0% +asked to say everything that we can + + + align:start position:0% +asked to say everything that we can +about the columns of the matrix a so I'm + + align:start position:0% +about the columns of the matrix a so I'm + + + align:start position:0% +about the columns of the matrix a so I'm +going to let you pretend that you're on + + align:start position:0% +going to let you pretend that you're on + + + align:start position:0% +going to let you pretend that you're on +an exam try to solve it yourself and + + align:start position:0% +an exam try to solve it yourself and + + + align:start position:0% +an exam try to solve it yourself and +then come back and compare your solution + + align:start position:0% +then come back and compare your solution + + + align:start position:0% +then come back and compare your solution +with mine ok welcome back so the first + + align:start position:0% +with mine ok welcome back so the first + + + align:start position:0% +with mine ok welcome back so the first +thing that you should think about in + + align:start position:0% +thing that you should think about in + + + align:start position:0% +thing that you should think about in +this sort of situation is what is the + + align:start position:0% +this sort of situation is what is the + + + align:start position:0% +this sort of situation is what is the +size of a well we want to multiply a + + align:start position:0% +size of a well we want to multiply a + + + align:start position:0% +size of a well we want to multiply a +with an X that has three entries so a + + align:start position:0% +with an X that has three entries so a + + + align:start position:0% +with an X that has three entries so a +should have three columns + + align:start position:0% +should have three columns + + + align:start position:0% +should have three columns +let me call those columns c1 c2 and c3 + + align:start position:0% +let me call those columns c1 c2 and c3 + + + align:start position:0% +let me call those columns c1 c2 and c3 +and when I take some linear combinations + + align:start position:0% +and when I take some linear combinations + + + align:start position:0% +and when I take some linear combinations +of c1 c2 and c3 I'm going to get this + + align:start position:0% +of c1 c2 and c3 I'm going to get this + + + align:start position:0% +of c1 c2 and c3 I'm going to get this +vector here 1 4 1 1 so all the sea-ice + + align:start position:0% +vector here 1 4 1 1 so all the sea-ice + + + align:start position:0% +vector here 1 4 1 1 so all the sea-ice +c1 c2 and c3 are vectors in R 4 now if + + align:start position:0% +c1 c2 and c3 are vectors in R 4 now if + + + align:start position:0% +c1 c2 and c3 are vectors in R 4 now if +you know about if you learned about + + align:start position:0% +you know about if you learned about + + + align:start position:0% +you know about if you learned about +particular solutions and special + + align:start position:0% +particular solutions and special + + + align:start position:0% +particular solutions and special +solutions then my notation here + + align:start position:0% +solutions then my notation here + + + align:start position:0% +solutions then my notation here +shouldn't surprise you I'm going to call + + align:start position:0% +shouldn't surprise you I'm going to call + + + align:start position:0% +shouldn't surprise you I'm going to call +this vector here X P and this vector + + align:start position:0% +this vector here X P and this vector + + + align:start position:0% +this vector here X P and this vector +here XS and I'm going to use the fact + + align:start position:0% +here XS and I'm going to use the fact + + + align:start position:0% +here XS and I'm going to use the fact +that X P plus C times X s satisfies + + align:start position:0% +that X P plus C times X s satisfies + + + align:start position:0% +that X P plus C times X s satisfies +eighty times this equals B I will call + + align:start position:0% +eighty times this equals B I will call + + + align:start position:0% +eighty times this equals B I will call +this vector B for any number C in + + align:start position:0% +this vector B for any number C in + + + align:start position:0% +this vector B for any number C in +particular what I'm going to conclude is + + align:start position:0% +particular what I'm going to conclude is + + + align:start position:0% +particular what I'm going to conclude is +that when C equals zero we get a times X + + align:start position:0% +that when C equals zero we get a times X + + + align:start position:0% +that when C equals zero we get a times X +P equals B but also that when C equals + + align:start position:0% +P equals B but also that when C equals + + + align:start position:0% +P equals B but also that when C equals +one we get a times X P plus a times X s + + align:start position:0% +one we get a times X P plus a times X s + + + align:start position:0% +one we get a times X P plus a times X s +equals B replacing this by B we get the + + align:start position:0% +equals B replacing this by B we get the + + + align:start position:0% +equals B replacing this by B we get the +dis implies that a times X s equals zero + + align:start position:0% +dis implies that a times X s equals zero + + + align:start position:0% +dis implies that a times X s equals zero +so in trying to find what are the + + align:start position:0% +so in trying to find what are the + + + align:start position:0% +so in trying to find what are the +columns C 1 C 2 and C 3 of the matrix a + + align:start position:0% +columns C 1 C 2 and C 3 of the matrix a + + + align:start position:0% +columns C 1 C 2 and C 3 of the matrix a +let's look at these two equations X P + + align:start position:0% +let's look at these two equations X P + + + align:start position:0% +let's look at these two equations X P +satisfies a times X P equals B and X s + + align:start position:0% +satisfies a times X P equals B and X s + + + align:start position:0% +satisfies a times X P equals B and X s +satisfies a times X s equals 0 again if + + align:start position:0% +satisfies a times X s equals 0 again if + + + align:start position:0% +satisfies a times X s equals 0 again if +you know what particular and special + + align:start position:0% +you know what particular and special + + + align:start position:0% +you know what particular and special +solutions are this shouldn't surprise + + align:start position:0% +solutions are this shouldn't surprise + + + align:start position:0% +solutions are this shouldn't surprise +you but we also know what X P and X s + + align:start position:0% +you but we also know what X P and X s + + + align:start position:0% +you but we also know what X P and X s +are so let's use them to try to + + align:start position:0% +are so let's use them to try to + + + align:start position:0% +are so let's use them to try to +calculate C 1 C 2 and C 3 a times X P + + align:start position:0% +calculate C 1 C 2 and C 3 a times X P + + + align:start position:0% +calculate C 1 C 2 and C 3 a times X P +equals B means that the linear + + align:start position:0% +equals B means that the linear + + + align:start position:0% +equals B means that the linear +combination of C 1 C 2 and C 3 encoded + + align:start position:0% +combination of C 1 C 2 and C 3 encoded + + + align:start position:0% +combination of C 1 C 2 and C 3 encoded +in the vector X P which is 0 1 1 gives + + align:start position:0% +in the vector X P which is 0 1 1 gives + + + align:start position:0% +in the vector X P which is 0 1 1 gives +the vector B so C 1 C 2 C 3 times 0 1 1 + + align:start position:0% +the vector B so C 1 C 2 C 3 times 0 1 1 + + + align:start position:0% +the vector B so C 1 C 2 C 3 times 0 1 1 +gives us 1 4 1 1 in other words C 2 plus + + align:start position:0% +gives us 1 4 1 1 in other words C 2 plus + + + align:start position:0% +gives us 1 4 1 1 in other words C 2 plus +C 3 equal B let's turn our attention to + + align:start position:0% +C 3 equal B let's turn our attention to + + + align:start position:0% +C 3 equal B let's turn our attention to +a times X s equals 0 + + align:start position:0% +a times X s equals 0 + + + align:start position:0% +a times X s equals 0 +this says that C 1 C 2 + + align:start position:0% +this says that C 1 C 2 + + + align:start position:0% +this says that C 1 C 2 +see three times excess was defined to be + + align:start position:0% +see three times excess was defined to be + + + align:start position:0% +see three times excess was defined to be +0 to 1 equals 0 in other words two times + + align:start position:0% +0 to 1 equals 0 in other words two times + + + align:start position:0% +0 to 1 equals 0 in other words two times +C 2 plus C 3 equals 0 now solving this + + align:start position:0% +C 2 plus C 3 equals 0 now solving this + + + align:start position:0% +C 2 plus C 3 equals 0 now solving this +system we were the unknowns are vectors + + align:start position:0% +system we were the unknowns are vectors + + + align:start position:0% +system we were the unknowns are vectors +but it still still just a linear system + + align:start position:0% +but it still still just a linear system + + + align:start position:0% +but it still still just a linear system +we can see for example from the second + + align:start position:0% +we can see for example from the second + + + align:start position:0% +we can see for example from the second +equation that C 3 equals -2 C 2 and + + align:start position:0% +equation that C 3 equals -2 C 2 and + + + align:start position:0% +equation that C 3 equals -2 C 2 and +plugging it back into the original + + align:start position:0% +plugging it back into the original + + + align:start position:0% +plugging it back into the original +equation getting C 2 minus 2 C 2 equals + + align:start position:0% +equation getting C 2 minus 2 C 2 equals + + + align:start position:0% +equation getting C 2 minus 2 C 2 equals +B from which it follows that C 2 is + + align:start position:0% +B from which it follows that C 2 is + + + align:start position:0% +B from which it follows that C 2 is +equal to minus B and that C 3 is equal + + align:start position:0% +equal to minus B and that C 3 is equal + + + align:start position:0% +equal to minus B and that C 3 is equal +to 2 times B so from this tiny amount of + + align:start position:0% +to 2 times B so from this tiny amount of + + + align:start position:0% +to 2 times B so from this tiny amount of +information we just knew the the + + align:start position:0% +information we just knew the the + + + align:start position:0% +information we just knew the the +solutions to this one particular + + align:start position:0% +solutions to this one particular + + + align:start position:0% +solutions to this one particular +equation involving a we got the second + + align:start position:0% +equation involving a we got the second + + + align:start position:0% +equation involving a we got the second +column of a and the third column of a + + align:start position:0% +column of a and the third column of a + + + align:start position:0% +column of a and the third column of a +completely explicitly calculated now + + align:start position:0% +completely explicitly calculated now + + + align:start position:0% +completely explicitly calculated now +what can we say about the first call I + + align:start position:0% +what can we say about the first call I + + + align:start position:0% +what can we say about the first call I +said before that um all the solutions of + + align:start position:0% +said before that um all the solutions of + + + align:start position:0% +said before that um all the solutions of +AX equals B are of the form a particular + + align:start position:0% +AX equals B are of the form a particular + + + align:start position:0% +AX equals B are of the form a particular +solution plus some number times a + + align:start position:0% +solution plus some number times a + + + align:start position:0% +solution plus some number times a +special solution and the information + + align:start position:0% +special solution and the information + + + align:start position:0% +special solution and the information +that we have is that there's just one + + align:start position:0% +that we have is that there's just one + + + align:start position:0% +that we have is that there's just one +number here so we said everything once + + align:start position:0% +number here so we said everything once + + + align:start position:0% +number here so we said everything once +we remove this vector here everything + + align:start position:0% +we remove this vector here everything + + + align:start position:0% +we remove this vector here everything +that we get here will satisfy a times x + + align:start position:0% +that we get here will satisfy a times x + + + align:start position:0% +that we get here will satisfy a times x +equals 0 and the fact that there is only + + align:start position:0% +equals 0 and the fact that there is only + + + align:start position:0% +equals 0 and the fact that there is only +that everything that satisfies a times x + + align:start position:0% +that everything that satisfies a times x + + + align:start position:0% +that everything that satisfies a times x +equals 0 is a multiple of this one + + align:start position:0% +equals 0 is a multiple of this one + + + align:start position:0% +equals 0 is a multiple of this one +vector that was given to us means that + + align:start position:0% +vector that was given to us means that + + + align:start position:0% +vector that was given to us means that +the null space of a has dimension 1 + + align:start position:0% +the null space of a has dimension 1 + + + align:start position:0% +the null space of a has dimension 1 +there is just one special solution so + + align:start position:0% + + + + align:start position:0% + +dimension of the null space of a is 1 + + align:start position:0% + + + + align:start position:0% + +so rank of a is the number of combs + + align:start position:0% +so rank of a is the number of combs + + + align:start position:0% +so rank of a is the number of combs +- this dimension of null space and it's + + align:start position:0% +- this dimension of null space and it's + + + align:start position:0% +- this dimension of null space and it's +equal to 2's rank of a is equal to 2 the + + align:start position:0% +equal to 2's rank of a is equal to 2 the + + + align:start position:0% +equal to 2's rank of a is equal to 2 the +number of linearly independent columns + + align:start position:0% +number of linearly independent columns + + + align:start position:0% +number of linearly independent columns +needs to be 2 as well so the only thing + + align:start position:0% +needs to be 2 as well so the only thing + + + align:start position:0% +needs to be 2 as well so the only thing +that we can say at this point is if the + + align:start position:0% +that we can say at this point is if the + + + align:start position:0% +that we can say at this point is if the +first column was also a multiple of B as + + align:start position:0% +first column was also a multiple of B as + + + align:start position:0% +first column was also a multiple of B as +the second and the third are then the + + align:start position:0% +the second and the third are then the + + + align:start position:0% +the second and the third are then the +ring would be smaller than 2 so that is + + align:start position:0% +ring would be smaller than 2 so that is + + + align:start position:0% +ring would be smaller than 2 so that is +the only thing that cannot happen so c1 + + align:start position:0% + + + + align:start position:0% + +is not a multiple of B not any multiple + + align:start position:0% +is not a multiple of B not any multiple + + + align:start position:0% +is not a multiple of B not any multiple +cluding not a zero multiple and that's + + align:start position:0% +cluding not a zero multiple and that's + + + align:start position:0% +cluding not a zero multiple and that's +pretty much everything we can say umm + + align:start position:0% +pretty much everything we can say umm + + + align:start position:0% +pretty much everything we can say umm +yes if it was some other multiple of it + + align:start position:0% +yes if it was some other multiple of it + + + align:start position:0% +yes if it was some other multiple of it +then we would be able to find some other + + align:start position:0% +then we would be able to find some other + + + align:start position:0% +then we would be able to find some other +vector here and we would have two + + align:start position:0% +vector here and we would have two + + + align:start position:0% +vector here and we would have two +parameters but it's not and this is + + align:start position:0% +parameters but it's not and this is + + + align:start position:0% +parameters but it's not and this is +everything that we can say about \ No newline at end of file diff --git a/Oo4iCE48xCc.txt b/Oo4iCE48xCc.txt new file mode 100644 index 0000000000000000000000000000000000000000..012b585af202b180ead88b56fdc8784e41e25558 --- /dev/null +++ b/Oo4iCE48xCc.txt @@ -0,0 +1,10459 @@ +align:start position:0% + +fault tolerant Computing and today's + + align:start position:0% +fault tolerant Computing and today's + + + align:start position:0% +fault tolerant Computing and today's +topic is um one of the most important + + align:start position:0% +topic is um one of the most important + + + align:start position:0% +topic is um one of the most important +Concepts in this uh in this area and + + align:start position:0% +Concepts in this uh in this area and + + + align:start position:0% +Concepts in this uh in this area and +it's called atomicity and what we're + + align:start position:0% +it's called atomicity and what we're + + + align:start position:0% +it's called atomicity and what we're +going to do is spend time um + + align:start position:0% +going to do is spend time um + + + align:start position:0% +going to do is spend time um +understanding what this is as a concept + + align:start position:0% +understanding what this is as a concept + + + align:start position:0% +understanding what this is as a concept +and then understanding how to achieve um + + align:start position:0% +and then understanding how to achieve um + + + align:start position:0% +and then understanding how to achieve um +atomicity in in U + + align:start position:0% +atomicity in in U + + + align:start position:0% +atomicity in in U +systems and recall that the main + + align:start position:0% +systems and recall that the main + + + align:start position:0% +systems and recall that the main +goal is to handle failures and that's + + align:start position:0% +goal is to handle failures and that's + + + align:start position:0% +goal is to handle failures and that's +what we talked about um the last time um + + align:start position:0% +what we talked about um the last time um + + + align:start position:0% +what we talked about um the last time um +and we came up with a bunch of different + + align:start position:0% +and we came up with a bunch of different + + + align:start position:0% +and we came up with a bunch of different +ways of thinking about failures and how + + align:start position:0% +ways of thinking about failures and how + + + align:start position:0% +ways of thinking about failures and how +to cope with it and one idea that we saw + + align:start position:0% +to cope with it and one idea that we saw + + + align:start position:0% +to cope with it and one idea that we saw +the last + + align:start position:0% +the last + + + align:start position:0% +the last +time was an idea + + align:start position:0% + + + + align:start position:0% + +involving replicating a component um + + align:start position:0% +involving replicating a component um + + + align:start position:0% +involving replicating a component um +let's say you know a dis or um any um + + align:start position:0% +let's say you know a dis or um any um + + + align:start position:0% +let's say you know a dis or um any um +component that you wish to U whose + + align:start position:0% +component that you wish to U whose + + + align:start position:0% +component that you wish to U whose +failure you wish to cope with and vote + + align:start position:0% +failure you wish to cope with and vote + + + align:start position:0% +failure you wish to cope with and vote +on the + + align:start position:0% + + + + align:start position:0% + +results and so the idea is that um if + + align:start position:0% +results and so the idea is that um if + + + align:start position:0% +results and so the idea is that um if +you're not exactly sure what the right + + align:start position:0% +you're not exactly sure what the right + + + align:start position:0% +you're not exactly sure what the right +answer should be if you're not sure + + align:start position:0% +answer should be if you're not sure + + + align:start position:0% +answer should be if you're not sure +whether any given component is working + + align:start position:0% +whether any given component is working + + + align:start position:0% +whether any given component is working +correctly or not replicate that + + align:start position:0% +correctly or not replicate that + + + align:start position:0% +correctly or not replicate that +component and then give them all the + + align:start position:0% +component and then give them all the + + + align:start position:0% +component and then give them all the +same input see what output they produce + + align:start position:0% +same input see what output they produce + + + align:start position:0% +same input see what output they produce +and then vote on the results and it turn + + align:start position:0% +and then vote on the results and it turn + + + align:start position:0% +and then vote on the results and it turn +and and we did see that these things are + + align:start position:0% +and and we did see that these things are + + + align:start position:0% +and and we did see that these things are +pretty sophisticated but the main + + align:start position:0% +pretty sophisticated but the main + + + align:start position:0% +pretty sophisticated but the main +problem with replicate plus vote is that + + align:start position:0% +problem with replicate plus vote is that + + + align:start position:0% +problem with replicate plus vote is that +often it's extremely expensive to build + + align:start position:0% +often it's extremely expensive to build + + + align:start position:0% +often it's extremely expensive to build +or very very hard to get right um and + + align:start position:0% +or very very hard to get right um and + + + align:start position:0% +or very very hard to get right um and +second um it often doesn't actually work + + align:start position:0% +second um it often doesn't actually work + + + align:start position:0% +second um it often doesn't actually work +for example uh if you just take um a + + align:start position:0% +for example uh if you just take um a + + + align:start position:0% +for example uh if you just take um a +software program a software module and + + align:start position:0% +software program a software module and + + + align:start position:0% +software program a software module and +you know you make 100 copies or 95 + + align:start position:0% +you know you make 100 copies or 95 + + + align:start position:0% +you know you make 100 copies or 95 +copies of that software module and give + + align:start position:0% +copies of that software module and give + + + align:start position:0% +copies of that software module and give +them all the same input and then vote on + + align:start position:0% +them all the same input and then vote on + + + align:start position:0% +them all the same input and then vote on +the outputs if you have a bug in one of + + align:start position:0% +the outputs if you have a bug in one of + + + align:start position:0% +the outputs if you have a bug in one of +the modules and it's a bug that's + + align:start position:0% +the modules and it's a bug that's + + + align:start position:0% +the modules and it's a bug that's +actually replicated in all of the + + align:start position:0% +actually replicated in all of the + + + align:start position:0% +actually replicated in all of the +modules then all of the replicas are + + align:start position:0% +modules then all of the replicas are + + + align:start position:0% +modules then all of the replicas are +going to give you the same wrong answer + + align:start position:0% +going to give you the same wrong answer + + + align:start position:0% +going to give you the same wrong answer +so the key assumption behind replicating + + align:start position:0% +so the key assumption behind replicating + + + align:start position:0% +so the key assumption behind replicating +and voting is that the replicas are + + align:start position:0% +and voting is that the replicas are + + + align:start position:0% +and voting is that the replicas are +independent of each other and have + + align:start position:0% +independent of each other and have + + + align:start position:0% +independent of each other and have +independent um modes of failure and that + + align:start position:0% +independent um modes of failure and that + + + align:start position:0% +independent um modes of failure and that +may not be true um in all of your + + align:start position:0% +may not be true um in all of your + + + align:start position:0% +may not be true um in all of your +modules and so the way we're going to + + align:start position:0% +modules and so the way we're going to + + + align:start position:0% +modules and so the way we're going to +deal with this problem and even though + + align:start position:0% +deal with this problem and even though + + + align:start position:0% +deal with this problem and even though +it's possible to design software systems + + align:start position:0% +it's possible to design software systems + + + align:start position:0% +it's possible to design software systems +where the replicas are in fact + + align:start position:0% +where the replicas are in fact + + + align:start position:0% +where the replicas are in fact +independent of each other uh it'll turn + + align:start position:0% +independent of each other uh it'll turn + + + align:start position:0% +independent of each other uh it'll turn +out that it's quite expensive to do uh + + align:start position:0% +out that it's quite expensive to do uh + + + align:start position:0% +out that it's quite expensive to do uh +in many cases so what we're going to do + + align:start position:0% +in many cases so what we're going to do + + + align:start position:0% +in many cases so what we're going to do +is to relax this Assumption of having a + + align:start position:0% +is to relax this Assumption of having a + + + align:start position:0% +is to relax this Assumption of having a +system which uh U handles failures by + + align:start position:0% +system which uh U handles failures by + + + align:start position:0% +system which uh U handles failures by +giving the same input to multiple + + align:start position:0% +giving the same input to multiple + + + align:start position:0% +giving the same input to multiple +outputs and then voting on it we're + + align:start position:0% +outputs and then voting on it we're + + + align:start position:0% +outputs and then voting on it we're +going to relax that and instead look at + + align:start position:0% +going to relax that and instead look at + + + align:start position:0% +going to relax that and instead look at +a different + + align:start position:0% +a different + + + align:start position:0% +a different +concept called + + align:start position:0% + + + + align:start position:0% + +recoverability and the idea here is + + align:start position:0% +recoverability and the idea here is + + + align:start position:0% +recoverability and the idea here is +rather than to try to build a system to + + align:start position:0% +rather than to try to build a system to + + + align:start position:0% +rather than to try to build a system to +replicate modules so that to the higher + + align:start position:0% +replicate modules so that to the higher + + + align:start position:0% +replicate modules so that to the higher +layers it looks as if the underlying + + align:start position:0% +layers it looks as if the underlying + + + align:start position:0% +layers it looks as if the underlying +module has never failed because you've + + align:start position:0% +module has never failed because you've + + + align:start position:0% +module has never failed because you've +replicated it um the idea here is to + + align:start position:0% +replicated it um the idea here is to + + + align:start position:0% +replicated it um the idea here is to +allow the underlying module to fail but + + align:start position:0% +allow the underlying module to fail but + + + align:start position:0% +allow the underlying module to fail but +have it failed typically in a fail fast + + align:start position:0% +have it failed typically in a fail fast + + + align:start position:0% +have it failed typically in a fail fast +manner so that you can detect the + + align:start position:0% +manner so that you can detect the + + + align:start position:0% +manner so that you can detect the +failure and then arrange for that module + + align:start position:0% +failure and then arrange for that module + + + align:start position:0% +failure and then arrange for that module +to be restarted and when it restarts the + + align:start position:0% +to be restarted and when it restarts the + + + align:start position:0% +to be restarted and when it restarts the +idea is to make it so that module does + + align:start position:0% +idea is to make it so that module does + + + align:start position:0% +idea is to make it so that module does +something such that in the end you know + + align:start position:0% +something such that in the end you know + + + align:start position:0% +something such that in the end you know +know the state of the system after it + + align:start position:0% +know the state of the system after it + + + align:start position:0% +know the state of the system after it +does that thing usually some kind of a + + align:start position:0% +does that thing usually some kind of a + + + align:start position:0% +does that thing usually some kind of a +recovery procedure is that um you can + + align:start position:0% +recovery procedure is that um you can + + + align:start position:0% +recovery procedure is that um you can +get back to using that module so it's a + + align:start position:0% +get back to using that module so it's a + + + align:start position:0% +get back to using that module so it's a +little bit like rather than try to you + + align:start position:0% +little bit like rather than try to you + + + align:start position:0% +little bit like rather than try to you +know build you know the analogy might be + + align:start position:0% +know build you know the analogy might be + + + align:start position:0% +know build you know the analogy might be +something like this uh you might imagine + + align:start position:0% +something like this uh you might imagine + + + align:start position:0% +something like this uh you might imagine +let's say there's a little child who's + + align:start position:0% +let's say there's a little child who's + + + align:start position:0% +let's say there's a little child who's +learning to walk one approach for nature + + align:start position:0% +learning to walk one approach for nature + + + align:start position:0% +learning to walk one approach for nature +to have adopted would have been to try + + align:start position:0% +to have adopted would have been to try + + + align:start position:0% +to have adopted would have been to try +to make it so the child never Falls and + + align:start position:0% +to make it so the child never Falls and + + + align:start position:0% +to make it so the child never Falls and +there's a lot of complexity associated + + align:start position:0% +there's a lot of complexity associated + + + align:start position:0% +there's a lot of complexity associated +with always keeping that child walking + + align:start position:0% +with always keeping that child walking + + + align:start position:0% +with always keeping that child walking +or alternatively you could have a story + + align:start position:0% +or alternatively you could have a story + + + align:start position:0% +or alternatively you could have a story +where or a method by which every once in + + align:start position:0% +where or a method by which every once in + + + align:start position:0% +where or a method by which every once in +a while the Falls but then has a plan to + + align:start position:0% +a while the Falls but then has a plan to + + + align:start position:0% +a while the Falls but then has a plan to +wake up to get up from that fall and + + align:start position:0% +wake up to get up from that fall and + + + align:start position:0% +wake up to get up from that fall and +then + + align:start position:0% +then + + + align:start position:0% +then +restart so that's the plan that we're + + align:start position:0% +restart so that's the plan that we're + + + align:start position:0% +restart so that's the plan that we're +going to adopt and this notion here um + + align:start position:0% +going to adopt and this notion here um + + + align:start position:0% +going to adopt and this notion here um +is called recoverability and the general + + align:start position:0% +is called recoverability and the general + + + align:start position:0% +is called recoverability and the general +plan is going to be that if you have a + + align:start position:0% +plan is going to be that if you have a + + + align:start position:0% +plan is going to be that if you have a +module + + align:start position:0% +module + + + align:start position:0% +module +M1 which invokes another module + + align:start position:0% +M1 which invokes another module + + + align:start position:0% +M1 which invokes another module +M2 + + align:start position:0% +M2 + + + align:start position:0% +M2 +and M2 were to + + align:start position:0% +and M2 were to + + + align:start position:0% +and M2 were to +fail then the idea is that M2 fails and + + align:start position:0% +fail then the idea is that M2 fails and + + + align:start position:0% +fail then the idea is that M2 fails and +then it recovers and you restart the + + align:start position:0% +then it recovers and you restart the + + + align:start position:0% +then it recovers and you restart the +module and and you want to make sure + + align:start position:0% +module and and you want to make sure + + + align:start position:0% +module and and you want to make sure +that M2 is left in in a situation once + + align:start position:0% +that M2 is left in in a situation once + + + align:start position:0% +that M2 is left in in a situation once +it recovers where there's no partial + + align:start position:0% +it recovers where there's no partial + + + align:start position:0% +it recovers where there's no partial +State and I'll Define that more + + align:start position:0% +State and I'll Define that more + + + align:start position:0% +State and I'll Define that more +precisely when we as we go along today + + align:start position:0% +precisely when we as we go along today + + + align:start position:0% +precisely when we as we go along today +but the main idea is going to be to + + align:start position:0% +but the main idea is going to be to + + + align:start position:0% +but the main idea is going to be to +ensure that there is no vestage of + + align:start position:0% +ensure that there is no vestage of + + + align:start position:0% +ensure that there is no vestage of +previous computations that are in the + + align:start position:0% +previous computations that are in the + + + align:start position:0% +previous computations that are in the +middle of being wrong so the state of + + align:start position:0% +middle of being wrong so the state of + + + align:start position:0% +middle of being wrong so the state of +the system when it recovers is at a well + + align:start position:0% +the system when it recovers is at a well + + + align:start position:0% +the system when it recovers is at a well +understood point so that M1 can continue + + align:start position:0% +understood point so that M1 can continue + + + align:start position:0% +understood point so that M1 can continue +to use that so there's no partial state + + align:start position:0% +to use that so there's no partial state + + + align:start position:0% +to use that so there's no partial state +where partial uh is in quotes here and + + align:start position:0% +where partial uh is in quotes here and + + + align:start position:0% +where partial uh is in quotes here and +we'll we'll talk about what it means for + + align:start position:0% +we'll we'll talk about what it means for + + + align:start position:0% +we'll we'll talk about what it means for +some something to be in a partial State + + align:start position:0% +some something to be in a partial State + + + align:start position:0% +some something to be in a partial State +the idea is to prevent that from + + align:start position:0% + + + + align:start position:0% + +happening so we're going to do this by + + align:start position:0% +happening so we're going to do this by + + + align:start position:0% +happening so we're going to do this by +um starting with an example and the same + + align:start position:0% +um starting with an example and the same + + + align:start position:0% +um starting with an example and the same +example that I mentioned the last time + + align:start position:0% +example that I mentioned the last time + + + align:start position:0% +example that I mentioned the last time +which + + align:start position:0% +which + + + align:start position:0% +which +was a transfer of money from One bank + + align:start position:0% +was a transfer of money from One bank + + + align:start position:0% +was a transfer of money from One bank +account to another so there's a from + + align:start position:0% +account to another so there's a from + + + align:start position:0% +account to another so there's a from +account there's a two account and some + + align:start position:0% + + + + align:start position:0% + +dollar amount and you want to transfer + + align:start position:0% +dollar amount and you want to transfer + + + align:start position:0% +dollar amount and you want to transfer +money from from to two and it's whatever + + align:start position:0% +money from from to two and it's whatever + + + align:start position:0% +money from from to two and it's whatever +amount + + align:start position:0% +amount + + + align:start position:0% +amount +is and the problem here is of course + + align:start position:0% +is and the problem here is of course + + + align:start position:0% +is and the problem here is of course +that um in the middle of transfer this + + align:start position:0% +that um in the middle of transfer this + + + align:start position:0% +that um in the middle of transfer this +procedure might fail or might crash the + + align:start position:0% +procedure might fail or might crash the + + + align:start position:0% +procedure might fail or might crash the +system might crash and you might be left + + align:start position:0% +system might crash and you might be left + + + align:start position:0% +system might crash and you might be left +in a situation where um a part of this + + align:start position:0% +in a situation where um a part of this + + + align:start position:0% +in a situation where um a part of this +transfer has already run so to take a + + align:start position:0% +transfer has already run so to take a + + + align:start position:0% +transfer has already run so to take a +specific example here's an example of + + align:start position:0% +specific example here's an example of + + + align:start position:0% +specific example here's an example of +what the transfer procedure might look + + align:start position:0% +what the transfer procedure might look + + + align:start position:0% +what the transfer procedure might look +like um so it takes a from and a two and + + align:start position:0% +like um so it takes a from and a two and + + + align:start position:0% +like um so it takes a from and a two and +an amount uh and the first thing it does + + align:start position:0% +an amount uh and the first thing it does + + + align:start position:0% +an amount uh and the first thing it does +is to read from this so assume that all + + align:start position:0% +is to read from this so assume that all + + + align:start position:0% +is to read from this so assume that all +of this data is stored on disk um it + + align:start position:0% +of this data is stored on disk um it + + + align:start position:0% +of this data is stored on disk um it +reads you know from the from account and + + align:start position:0% +reads you know from the from account and + + + align:start position:0% +reads you know from the from account and +then it reduces that debits that amount + + align:start position:0% +then it reduces that debits that amount + + + align:start position:0% +then it reduces that debits that amount +uh debits the amount from that account + + align:start position:0% +uh debits the amount from that account + + + align:start position:0% +uh debits the amount from that account +and then writes back and it does the + + align:start position:0% +and then writes back and it does the + + + align:start position:0% +and then writes back and it does the +same same thing to the two accounts so + + align:start position:0% +same same thing to the two accounts so + + + align:start position:0% +same same thing to the two accounts so +in the end if this procedure completely + + align:start position:0% +in the end if this procedure completely + + + align:start position:0% +in the end if this procedure completely +ran then uh from account would be + + align:start position:0% +ran then uh from account would be + + + align:start position:0% +ran then uh from account would be +reduced by amount and to account would + + align:start position:0% +reduced by amount and to account would + + + align:start position:0% +reduced by amount and to account would +be um enhanced by amount of course the + + align:start position:0% +be um enhanced by amount of course the + + + align:start position:0% +be um enhanced by amount of course the +problem is you might have a failure + + align:start position:0% +problem is you might have a failure + + + align:start position:0% +problem is you might have a failure +anywhere in the middle and as a concrete + + align:start position:0% +anywhere in the middle and as a concrete + + + align:start position:0% +anywhere in the middle and as a concrete +example if the failure were to happen if + + align:start position:0% +example if the failure were to happen if + + + align:start position:0% +example if the failure were to happen if +a crash were to happen after the first + + align:start position:0% +a crash were to happen after the first + + + align:start position:0% +a crash were to happen after the first +three lines shown above um if you owned + + align:start position:0% +three lines shown above um if you owned + + + align:start position:0% +three lines shown above um if you owned +this account you wouldn't be very happy + + align:start position:0% +this account you wouldn't be very happy + + + align:start position:0% +this account you wouldn't be very happy +because you just lost some money from an + + align:start position:0% +because you just lost some money from an + + + align:start position:0% +because you just lost some money from an +account and nothing happened right no no + + align:start position:0% +account and nothing happened right no no + + + align:start position:0% +account and nothing happened right no no +other no no other account got money + + align:start position:0% +other no no other account got money + + + align:start position:0% +other no no other account got money +added to + + align:start position:0% +added to + + + align:start position:0% +added to +it and this is the problem that we want + + align:start position:0% +it and this is the problem that we want + + + align:start position:0% +it and this is the problem that we want +to avoid so if you think about this for + + align:start position:0% +to avoid so if you think about this for + + + align:start position:0% +to avoid so if you think about this for +a moment what you would like intuitively + + align:start position:0% +a moment what you would like intuitively + + + align:start position:0% +a moment what you would like intuitively +is that if a crash like this were to + + align:start position:0% +is that if a crash like this were to + + + align:start position:0% +is that if a crash like this were to +happen and the system were to recover + + align:start position:0% +happen and the system were to recover + + + align:start position:0% +happen and the system were to recover +and come back up there's really only two + + align:start position:0% +and come back up there's really only two + + + align:start position:0% +and come back up there's really only two +states that the system should be in for + + align:start position:0% +states that the system should be in for + + + align:start position:0% +states that the system should be in for +the system to really be correct and to + + align:start position:0% +the system to really be correct and to + + + align:start position:0% +the system to really be correct and to +meet what your intuition might expect + + align:start position:0% +meet what your intuition might expect + + + align:start position:0% +meet what your intuition might expect +either this procedure must completely be + + align:start position:0% +either this procedure must completely be + + + align:start position:0% +either this procedure must completely be +finished that is the state of the system + + align:start position:0% +finished that is the state of the system + + + align:start position:0% +finished that is the state of the system +must be the same as if this procedure + + align:start position:0% +must be the same as if this procedure + + + align:start position:0% +must be the same as if this procedure +completely ran and + + align:start position:0% +completely ran and + + + align:start position:0% +completely ran and +finished or the state of the system must + + align:start position:0% +finished or the state of the system must + + + align:start position:0% +finished or the state of the system must +be such that the procedure never ran at + + align:start position:0% +be such that the procedure never ran at + + + align:start position:0% +be such that the procedure never ran at +all it is not at all okay it's not okay + + align:start position:0% +all it is not at all okay it's not okay + + + align:start position:0% +all it is not at all okay it's not okay +to let the state of the system be um + + align:start position:0% +to let the state of the system be um + + + align:start position:0% +to let the state of the system be um +equal to whatever the state was at the + + align:start position:0% +equal to whatever the state was at the + + + align:start position:0% +equal to whatever the state was at the +time in this example at the time the + + align:start position:0% +time in this example at the time the + + + align:start position:0% +time in this example at the time the +crash + + align:start position:0% +crash + + + align:start position:0% +crash +happened so + + align:start position:0% +happened so + + + align:start position:0% +happened so +what you want is a kind of All or + + align:start position:0% +what you want is a kind of All or + + + align:start position:0% +what you want is a kind of All or +Nothing + + align:start position:0% + + + + align:start position:0% + +behavior of course if the crash happened + + align:start position:0% +behavior of course if the crash happened + + + align:start position:0% +behavior of course if the crash happened +as I've shown it here there's no way for + + align:start position:0% +as I've shown it here there's no way for + + + align:start position:0% +as I've shown it here there's no way for +you to have prevented those lines of + + align:start position:0% +you to have prevented those lines of + + + align:start position:0% +you to have prevented those lines of +code from being wrong right those lines + + align:start position:0% +code from being wrong right those lines + + + align:start position:0% +code from being wrong right those lines +of code ran and then the crash happened + + align:start position:0% +of code ran and then the crash happened + + + align:start position:0% +of code ran and then the crash happened +so what you really need is a way by + + align:start position:0% +so what you really need is a way by + + + align:start position:0% +so what you really need is a way by +which you can back out these changes the + + align:start position:0% +which you can back out these changes the + + + align:start position:0% +which you can back out these changes the +what the system needs is a way by which + + align:start position:0% +what the system needs is a way by which + + + align:start position:0% +what the system needs is a way by which +when the system crashes and then the + + align:start position:0% +when the system crashes and then the + + + align:start position:0% +when the system crashes and then the +recovers from the fault from the crash + + align:start position:0% +recovers from the fault from the crash + + + align:start position:0% +recovers from the fault from the crash +um during failure recovery the system + + align:start position:0% +um during failure recovery the system + + + align:start position:0% +um during failure recovery the system +has to have a way to back out of what + + align:start position:0% +has to have a way to back out of what + + + align:start position:0% +has to have a way to back out of what +whatever changes it's + + align:start position:0% +whatever changes it's + + + align:start position:0% +whatever changes it's +made in other words what we want is a + + align:start position:0% +made in other words what we want is a + + + align:start position:0% +made in other words what we want is a +concept called + + align:start position:0% + + + + align:start position:0% + +recoverability so more precise + + align:start position:0% +recoverability so more precise + + + align:start position:0% +recoverability so more precise +definition of recoverability is shown on + + align:start position:0% +definition of recoverability is shown on + + + align:start position:0% +definition of recoverability is shown on +the slide and let me just read it out um + + align:start position:0% +the slide and let me just read it out um + + + align:start position:0% +the slide and let me just read it out um +a composite sequence of steps which + + align:start position:0% +a composite sequence of steps which + + + align:start position:0% +a composite sequence of steps which +we're also going to use the word action + + align:start position:0% +we're also going to use the word action + + + align:start position:0% +we're also going to use the word action +for an action is recoverable if from the + + align:start position:0% +for an action is recoverable if from the + + + align:start position:0% +for an action is recoverable if from the +point of view of the module that invokes + + align:start position:0% +point of view of the module that invokes + + + align:start position:0% +point of view of the module that invokes +this + + align:start position:0% +this + + + align:start position:0% +this +action this sequence either always + + align:start position:0% +action this sequence either always + + + align:start position:0% +action this sequence either always +completes + + align:start position:0% +completes + + + align:start position:0% +completes +or aborts that is if it fails and then + + align:start position:0% +or aborts that is if it fails and then + + + align:start position:0% +or aborts that is if it fails and then +it you know backs out aborts in a way + + align:start position:0% +it you know backs out aborts in a way + + + align:start position:0% +it you know backs out aborts in a way +such that it appears that the sequence + + align:start position:0% +such that it appears that the sequence + + + align:start position:0% +such that it appears that the sequence +sequence had never started to begin with + + align:start position:0% +sequence had never started to begin with + + + align:start position:0% +sequence had never started to begin with +and in particular what this means is + + align:start position:0% +and in particular what this means is + + + align:start position:0% +and in particular what this means is +that if a failure were to happen in the + + align:start position:0% +that if a failure were to happen in the + + + align:start position:0% +that if a failure were to happen in the +middle when the system recovers um it + + align:start position:0% +middle when the system recovers um it + + + align:start position:0% +middle when the system recovers um it +better have a plan of backing out the + + align:start position:0% +better have a plan of backing out the + + + align:start position:0% +better have a plan of backing out the +changes in other words of aborting this + + align:start position:0% +changes in other words of aborting this + + + align:start position:0% +changes in other words of aborting this +action + + align:start position:0% +action + + + align:start position:0% +action +so the way you think about + + align:start position:0% +so the way you think about + + + align:start position:0% +so the way you think about +recoverability the che the the simple + + align:start position:0% +recoverability the che the the simple + + + align:start position:0% +recoverability the che the the simple +way to think about it is is do it all or + + align:start position:0% +way to think about it is is do it all or + + + align:start position:0% +way to think about it is is do it all or +not at + + align:start position:0% + + + + align:start position:0% + +all and our goal is to try to somehow + + align:start position:0% +all and our goal is to try to somehow + + + align:start position:0% +all and our goal is to try to somehow +come up with a way to achieve this + + align:start position:0% + + + + align:start position:0% + +goal before we get into a solution to + + align:start position:0% +goal before we get into a solution to + + + align:start position:0% +goal before we get into a solution to +this problem there's a few other + + align:start position:0% +this problem there's a few other + + + align:start position:0% +this problem there's a few other +Concepts um to discuss and they'll turn + + align:start position:0% +Concepts um to discuss and they'll turn + + + align:start position:0% +Concepts um to discuss and they'll turn +out to be very related to each other and + + align:start position:0% +out to be very related to each other and + + + align:start position:0% +out to be very related to each other and +the second concept after recoverability + + align:start position:0% +the second concept after recoverability + + + align:start position:0% +the second concept after recoverability +that's very closely related to this idea + + align:start position:0% +that's very closely related to this idea + + + align:start position:0% +that's very closely related to this idea +idea has to do with concurrent + + align:start position:0% + + + + align:start position:0% + +actions so imagine for a moment that you + + align:start position:0% +actions so imagine for a moment that you + + + align:start position:0% +actions so imagine for a moment that you +had the same transfer procedure as on um + + align:start position:0% +had the same transfer procedure as on um + + + align:start position:0% +had the same transfer procedure as on um +as in this example but you had two + + align:start position:0% +as in this example but you had two + + + align:start position:0% +as in this example but you had two +transfers running at the same + + align:start position:0% +transfers running at the same + + + align:start position:0% +transfers running at the same +time and they happen to act on the same + + align:start position:0% +time and they happen to act on the same + + + align:start position:0% +time and they happen to act on the same +um data + + align:start position:0% +um data + + + align:start position:0% +um data +items like + + align:start position:0% +items like + + + align:start position:0% +items like +that so let's say that the first + + align:start position:0% +that so let's say that the first + + + align:start position:0% +that so let's say that the first +transfer um moved from a saving account + + align:start position:0% +transfer um moved from a saving account + + + align:start position:0% +transfer um moved from a saving account +to checking account it moved + + align:start position:0% +to checking account it moved + + + align:start position:0% +to checking account it moved +$100 and the second one moved from + + align:start position:0% +$100 and the second one moved from + + + align:start position:0% +$100 and the second one moved from +saving to checkings it checking it moved + + align:start position:0% +saving to checkings it checking it moved + + + align:start position:0% +saving to checkings it checking it moved +$200 and let's say at the beginning s + + align:start position:0% +$200 and let's say at the beginning s + + + align:start position:0% +$200 and let's say at the beginning s +was + + align:start position:0% + + + + align:start position:0% + +th of course as you recall from um + + align:start position:0% +th of course as you recall from um + + + align:start position:0% +th of course as you recall from um +several lectures ago when you have these + + align:start position:0% +several lectures ago when you have these + + + align:start position:0% +several lectures ago when you have these +interl sequences um these two threads + + align:start position:0% +interl sequences um these two threads + + + align:start position:0% +interl sequences um these two threads +are running these the steps um that + + align:start position:0% +are running these the steps um that + + + align:start position:0% +are running these the steps um that +these threads are made of might be + + align:start position:0% +these threads are made of might be + + + align:start position:0% +these threads are made of might be +interleaved in arbitrary order if you + + align:start position:0% +interleaved in arbitrary order if you + + + align:start position:0% +interleaved in arbitrary order if you +don't have a plan to isolate + + align:start position:0% +don't have a plan to isolate + + + align:start position:0% +don't have a plan to isolate +them and in particular you might have + + align:start position:0% +them and in particular you might have + + + align:start position:0% +them and in particular you might have +you know many results that show up and + + align:start position:0% +you know many results that show up and + + + align:start position:0% +you know many results that show up and +one result that might show up is both of + + align:start position:0% +one result that might show up is both of + + + align:start position:0% +one result that might show up is both of +these transfers running concurrently + + align:start position:0% +these transfers running concurrently + + + align:start position:0% +these transfers running concurrently +read the same you know read thousand out + + align:start position:0% +read the same you know read thousand out + + + align:start position:0% +read the same you know read thousand out +from from account and then both of them + + align:start position:0% +from from account and then both of them + + + align:start position:0% +from from account and then both of them +debit by the right by 100 and 200 + + align:start position:0% +debit by the right by 100 and 200 + + + align:start position:0% +debit by the right by 100 and 200 +respectively so at the end of it you + + align:start position:0% +respectively so at the end of it you + + + align:start position:0% +respectively so at the end of it you +might be left with either $800 or $900 + + align:start position:0% +might be left with either $800 or $900 + + + align:start position:0% +might be left with either $800 or $900 +left in the account when the right + + align:start position:0% +left in the account when the right + + + align:start position:0% +left in the account when the right +answer is have been left uh intuitively + + align:start position:0% +answer is have been left uh intuitively + + + align:start position:0% +answer is have been left uh intuitively +if you ran both these transfers you + + align:start position:0% +if you ran both these transfers you + + + align:start position:0% +if you ran both these transfers you +would like to see $700 left uh in that + + align:start position:0% +would like to see $700 left uh in that + + + align:start position:0% +would like to see $700 left uh in that +account right so what you intuitively + + align:start position:0% +account right so what you intuitively + + + align:start position:0% +account right so what you intuitively +want here is if this this is the first + + align:start position:0% +want here is if this this is the first + + + align:start position:0% +want here is if this this is the first +action A1 and this is the second action + + align:start position:0% +action A1 and this is the second action + + + align:start position:0% +action A1 and this is the second action +A2 what you would like to see is a + + align:start position:0% +A2 what you would like to see is a + + + align:start position:0% +A2 what you would like to see is a +sequence you don't actually care what + + align:start position:0% +sequence you don't actually care what + + + align:start position:0% +sequence you don't actually care what +the order is between these two transfers + + align:start position:0% +the order is between these two transfers + + + align:start position:0% +the order is between these two transfers +right I mean you're transferring money + + align:start position:0% +right I mean you're transferring money + + + align:start position:0% +right I mean you're transferring money +from one account to another and you're + + align:start position:0% +from one account to another and you're + + + align:start position:0% +from one account to another and you're +doing two of these you don't actually + + align:start position:0% +doing two of these you don't actually + + + align:start position:0% +doing two of these you don't actually +care in this example and it'll turn out + + align:start position:0% +care in this example and it'll turn out + + + align:start position:0% +care in this example and it'll turn out +in most examples on all examples that + + align:start position:0% +in most examples on all examples that + + + align:start position:0% +in most examples on all examples that +we're going to be talking about um um in + + align:start position:0% +we're going to be talking about um um in + + + align:start position:0% +we're going to be talking about um um in +with this notion that you're not really + + align:start position:0% +with this notion that you're not really + + + align:start position:0% +with this notion that you're not really +going to care what the order is either + + align:start position:0% +going to care what the order is either + + + align:start position:0% +going to care what the order is either +order is perfectly fine but the order + + align:start position:0% +order is perfectly fine but the order + + + align:start position:0% +order is perfectly fine but the order +should be as if it's equivalent to + + align:start position:0% +should be as if it's equivalent to + + + align:start position:0% +should be as if it's equivalent to +either A1 before + + align:start position:0% +either A1 before + + + align:start position:0% +either A1 before +A2 + + align:start position:0% +A2 + + + align:start position:0% +A2 +or A2 before E1 before + + align:start position:0% + + + + align:start position:0% + +A1 and that's what we would + + align:start position:0% +A1 and that's what we would + + + align:start position:0% +A1 and that's what we would +like of course the you know sort of + + align:start position:0% +like of course the you know sort of + + + align:start position:0% +like of course the you know sort of +naive way to achieve this is to ensure + + align:start position:0% +naive way to achieve this is to ensure + + + align:start position:0% +naive way to achieve this is to ensure +that exactly one action runs at a time + + align:start position:0% +that exactly one action runs at a time + + + align:start position:0% +that exactly one action runs at a time +it finishes and then the second one runs + + align:start position:0% +it finishes and then the second one runs + + + align:start position:0% +it finishes and then the second one runs +but that's kind of going to be no fun + + align:start position:0% +but that's kind of going to be no fun + + + align:start position:0% +but that's kind of going to be no fun +for us to do it's the right Simple + + align:start position:0% +for us to do it's the right Simple + + + align:start position:0% +for us to do it's the right Simple +Solution but we're going to want to + + align:start position:0% +Solution but we're going to want to + + + align:start position:0% +Solution but we're going to want to +improve concurrency as we wanted to um + + align:start position:0% +improve concurrency as we wanted to um + + + align:start position:0% +improve concurrency as we wanted to um +you know several lectures ago so we're + + align:start position:0% +you know several lectures ago so we're + + + align:start position:0% +you know several lectures ago so we're +going to come up with ways of getting + + align:start position:0% +going to come up with ways of getting + + + align:start position:0% +going to come up with ways of getting +higher performance than running one + + align:start position:0% +higher performance than running one + + + align:start position:0% +higher performance than running one +after the other but the net effect is as + + align:start position:0% +after the other but the net effect is as + + + align:start position:0% +after the other but the net effect is as +if you run it in some serial order in + + align:start position:0% +if you run it in some serial order in + + + align:start position:0% +if you run it in some serial order in +some sequential order of the actions um + + align:start position:0% +some sequential order of the actions um + + + align:start position:0% +some sequential order of the actions um +that is the result of running concurrent + + align:start position:0% +that is the result of running concurrent + + + align:start position:0% +that is the result of running concurrent +actions has to be the same as some + + align:start position:0% +actions has to be the same as some + + + align:start position:0% +actions has to be the same as some +serial ordering of the of the individual + + align:start position:0% +serial ordering of the of the individual + + + align:start position:0% +serial ordering of the of the individual +actions and this idea of A1 before A2 or + + align:start position:0% +actions and this idea of A1 before A2 or + + + align:start position:0% +actions and this idea of A1 before A2 or +A2 before A1 has a name it's called + + align:start position:0% +A2 before A1 has a name it's called + + + align:start position:0% +A2 before A1 has a name it's called +isolation + + align:start position:0% + + + + align:start position:0% + +and you should distinguish that in your + + align:start position:0% +and you should distinguish that in your + + + align:start position:0% +and you should distinguish that in your +mind clearly from + + align:start position:0% + + + + align:start position:0% + +recoverability so more precise + + align:start position:0% +recoverability so more precise + + + align:start position:0% +recoverability so more precise +definition of isolation is essentially + + align:start position:0% +definition of isolation is essentially + + + align:start position:0% +definition of isolation is essentially +what I said before + + align:start position:0% +what I said before + + + align:start position:0% +what I said before +the equivalent the a composite sequence + + align:start position:0% +the equivalent the a composite sequence + + + align:start position:0% +the equivalent the a composite sequence +of steps is isolated if its effect from + + align:start position:0% +of steps is isolated if its effect from + + + align:start position:0% +of steps is isolated if its effect from +the point of view of its invoker is the + + align:start position:0% +the point of view of its invoker is the + + + align:start position:0% +the point of view of its invoker is the +same as if the action occurred either + + align:start position:0% +same as if the action occurred either + + + align:start position:0% +same as if the action occurred either +completely before or completely after + + align:start position:0% +completely before or completely after + + + align:start position:0% +completely before or completely after +every other isolated + + align:start position:0% +every other isolated + + + align:start position:0% +every other isolated +action and the simple way to understand + + align:start position:0% +action and the simple way to understand + + + align:start position:0% +action and the simple way to understand +this is you either do it all before or + + align:start position:0% +this is you either do it all before or + + + align:start position:0% +this is you either do it all before or +do it all after there is the net effect + + align:start position:0% +do it all after there is the net effect + + + align:start position:0% +do it all after there is the net effect +has to be the same as doing it all + + align:start position:0% +has to be the same as doing it all + + + align:start position:0% +has to be the same as doing it all +before or doing it all after and it's + + align:start position:0% +before or doing it all after and it's + + + align:start position:0% +before or doing it all after and it's +different from recoverability which is + + align:start position:0% +different from recoverability which is + + + align:start position:0% +different from recoverability which is +really do it all or not at + + align:start position:0% + + + + align:start position:0% + +all now when you have a A system + + align:start position:0% +all now when you have a A system + + + align:start position:0% +all now when you have a A system +that satisfies both recoverability and + + align:start position:0% +that satisfies both recoverability and + + + align:start position:0% +that satisfies both recoverability and +isolation so the way to understand this + + align:start position:0% +isolation so the way to understand this + + + align:start position:0% +isolation so the way to understand this +is both of these really although they're + + align:start position:0% +is both of these really although they're + + + align:start position:0% +is both of these really although they're +talking about different concepts this is + + align:start position:0% +talking about different concepts this is + + + align:start position:0% +talking about different concepts this is +saying all or nothing and this is saying + + align:start position:0% +saying all or nothing and this is saying + + + align:start position:0% +saying all or nothing and this is saying +all before or all after both of these + + align:start position:0% +all before or all after both of these + + + align:start position:0% +all before or all after both of these +are getting at the same intuitive idea + + align:start position:0% +are getting at the same intuitive idea + + + align:start position:0% +are getting at the same intuitive idea +which is that somehow there's the + + align:start position:0% +which is that somehow there's the + + + align:start position:0% +which is that somehow there's the +sequence of steps in um for example in + + align:start position:0% +sequence of steps in um for example in + + + align:start position:0% +sequence of steps in um for example in +this transfer procedure there are the + + align:start position:0% +this transfer procedure there are the + + + align:start position:0% +this transfer procedure there are the +sequences of steps and somehow you want + + align:start position:0% +sequences of steps and somehow you want + + + align:start position:0% +sequences of steps and somehow you want +to make it look as if for each action um + + align:start position:0% +to make it look as if for each action um + + + align:start position:0% +to make it look as if for each action um +the sequence of steps is not visible to + + align:start position:0% +the sequence of steps is not visible to + + + align:start position:0% +the sequence of steps is not visible to +somebody invoking the action right + + align:start position:0% +somebody invoking the action right + + + align:start position:0% +somebody invoking the action right +because you don't want the person + + align:start position:0% +because you don't want the person + + + align:start position:0% +because you don't want the person +invoking this action for recoverability + + align:start position:0% +invoking this action for recoverability + + + align:start position:0% +invoking this action for recoverability +you don't want him to know that it's + + align:start position:0% +you don't want him to know that it's + + + align:start position:0% +you don't want him to know that it's +built out of sequence of steps and if a + + align:start position:0% +built out of sequence of steps and if a + + + align:start position:0% +built out of sequence of steps and if a +failure happens in the middle you don't + + align:start position:0% +failure happens in the middle you don't + + + align:start position:0% +failure happens in the middle you don't +want the invoker of that action to see + + align:start position:0% +want the invoker of that action to see + + + align:start position:0% +want the invoker of that action to see +some partial State likewise when you + + align:start position:0% +some partial State likewise when you + + + align:start position:0% +some partial State likewise when you +have concurrent actions running together + + align:start position:0% +have concurrent actions running together + + + align:start position:0% +have concurrent actions running together +you don't want the different invokers of + + align:start position:0% +you don't want the different invokers of + + + align:start position:0% +you don't want the different invokers of +that action to somehow see this modeled + + align:start position:0% +that action to somehow see this modeled + + + align:start position:0% +that action to somehow see this modeled +result of the interleaving you want them + + align:start position:0% +result of the interleaving you want them + + + align:start position:0% +result of the interleaving you want them +to only see the results of running these + + align:start position:0% +to only see the results of running these + + + align:start position:0% +to only see the results of running these +actions one after the + + align:start position:0% +actions one after the + + + align:start position:0% +actions one after the +other so what you're really trying to + + align:start position:0% +other so what you're really trying to + + + align:start position:0% +other so what you're really trying to +achieve for both of these Concepts + + align:start position:0% +achieve for both of these Concepts + + + align:start position:0% +achieve for both of these Concepts +although they're distinct Concepts what + + align:start position:0% +although they're distinct Concepts what + + + align:start position:0% +although they're distinct Concepts what +you're really trying to achieve is to + + align:start position:0% +you're really trying to achieve is to + + + align:start position:0% +you're really trying to achieve is to +hide the fact that this action is a + + align:start position:0% +hide the fact that this action is a + + + align:start position:0% +hide the fact that this action is a +composite sequence of steps you want to + + align:start position:0% +composite sequence of steps you want to + + + align:start position:0% +composite sequence of steps you want to +make it look as if it's quite monolithic + + align:start position:0% +make it look as if it's quite monolithic + + + align:start position:0% +make it look as if it's quite monolithic +and this idea of wanting something to + + align:start position:0% +and this idea of wanting something to + + + align:start position:0% +and this idea of wanting something to +look monolithic is called atom + + align:start position:0% + + + + align:start position:0% + +atomicity and we're going to basically + + align:start position:0% +atomicity and we're going to basically + + + align:start position:0% +atomicity and we're going to basically +be + + align:start position:0% + + + + align:start position:0% + +hiding the fact that it's + + align:start position:0% + + + + align:start position:0% + +composite so more + + align:start position:0% +composite so more + + + align:start position:0% +composite so more +precisely for this course we're going to + + align:start position:0% +precisely for this course we're going to + + + align:start position:0% +precisely for this course we're going to +use the word Atomic to mean recoverable + + align:start position:0% +use the word Atomic to mean recoverable + + + align:start position:0% +use the word Atomic to mean recoverable +and + + align:start position:0% +and + + + align:start position:0% +and +isolated okay I'm going to say for this + + align:start position:0% +isolated okay I'm going to say for this + + + align:start position:0% +isolated okay I'm going to say for this +course because these terms have been um + + align:start position:0% +course because these terms have been um + + + align:start position:0% +course because these terms have been um +in use in various different ways uh for + + align:start position:0% +in use in various different ways uh for + + + align:start position:0% +in use in various different ways uh for +at least you know probably more than 30 + + align:start position:0% +at least you know probably more than 30 + + + align:start position:0% +at least you know probably more than 30 +years and I think it's about time we + + align:start position:0% +years and I think it's about time we + + + align:start position:0% +years and I think it's about time we +made these + + align:start position:0% +made these + + + align:start position:0% +made these +precise so in the literature you'll see + + align:start position:0% +precise so in the literature you'll see + + + align:start position:0% +precise so in the literature you'll see +the word Atomic to often mean + + align:start position:0% +the word Atomic to often mean + + + align:start position:0% +the word Atomic to often mean +recoverable and sometimes and this is + + align:start position:0% +recoverable and sometimes and this is + + + align:start position:0% +recoverable and sometimes and this is +unfortunate sometimes you'll see the + + align:start position:0% +unfortunate sometimes you'll see the + + + align:start position:0% +unfortunate sometimes you'll see the +word consistent to mean isolated and in + + align:start position:0% +word consistent to mean isolated and in + + + align:start position:0% +word consistent to mean isolated and in +particular you'll run into this + + align:start position:0% +particular you'll run into this + + + align:start position:0% +particular you'll run into this +confusion when you read the recitation + + align:start position:0% +confusion when you read the recitation + + + align:start position:0% +confusion when you read the recitation +paper for recitation on Thursday the + + align:start position:0% +paper for recitation on Thursday the + + + align:start position:0% +paper for recitation on Thursday the +system R + + align:start position:0% +system R + + + align:start position:0% +system R +paper um but we'll use the word uh the + + align:start position:0% +paper um but we'll use the word uh the + + + align:start position:0% +paper um but we'll use the word uh the +problem is those terms are used you know + + align:start position:0% +problem is those terms are used you know + + + align:start position:0% +problem is those terms are used you know +historically haven't been used in a very + + align:start position:0% +historically haven't been used in a very + + + align:start position:0% +historically haven't been used in a very +precise way so we'll Define it precisely + + align:start position:0% +precise way so we'll Define it precisely + + + align:start position:0% +precise way so we'll Define it precisely +when we say something is atomic we mean + + align:start position:0% +when we say something is atomic we mean + + + align:start position:0% +when we say something is atomic we mean +in general we mean both recoverable and + + align:start position:0% +in general we mean both recoverable and + + + align:start position:0% +in general we mean both recoverable and +isolated when we mean only one of them + + align:start position:0% +isolated when we mean only one of them + + + align:start position:0% +isolated when we mean only one of them +we will say Atomic with respect to + + align:start position:0% +we will say Atomic with respect to + + + align:start position:0% +we will say Atomic with respect to +recoverability or recoverable um Atomic + + align:start position:0% +recoverability or recoverable um Atomic + + + align:start position:0% +recoverability or recoverable um Atomic +with respect to isolation or + + align:start position:0% +with respect to isolation or + + + align:start position:0% +with respect to isolation or +isolated and like I said Atomic means + + align:start position:0% +isolated and like I said Atomic means + + + align:start position:0% +isolated and like I said Atomic means +recoverable and isolated + + align:start position:0% +recoverable and isolated + + + align:start position:0% +recoverable and isolated +and the general plan is to hide the fact + + align:start position:0% +and the general plan is to hide the fact + + + align:start position:0% +and the general plan is to hide the fact +that an action is built out of composite + + align:start position:0% +that an action is built out of composite + + + align:start position:0% +that an action is built out of composite +sequence of + + align:start position:0% + + + + align:start position:0% + +steps now to add to this confusion of + + align:start position:0% +steps now to add to this confusion of + + + align:start position:0% +steps now to add to this confusion of +terminology there are actually two other + + align:start position:0% +terminology there are actually two other + + + align:start position:0% +terminology there are actually two other +terms that um or two other properties + + align:start position:0% +terms that um or two other properties + + + align:start position:0% +terms that um or two other properties +that you often want from + + align:start position:0% +that you often want from + + + align:start position:0% +that you often want from +actions in addition to recoverability + + align:start position:0% +actions in addition to recoverability + + + align:start position:0% +actions in addition to recoverability +and + + align:start position:0% + + + + align:start position:0% + +isolation and these two other properties + + align:start position:0% +isolation and these two other properties + + + align:start position:0% +isolation and these two other properties +are provided by many database systems + + align:start position:0% +are provided by many database systems + + + align:start position:0% +are provided by many database systems +which are you know one of the most + + align:start position:0% +which are you know one of the most + + + align:start position:0% +which are you know one of the most +common users of these Concepts most + + align:start position:0% +common users of these Concepts most + + + align:start position:0% +common users of these Concepts most +common system that provides atomicity uh + + align:start position:0% +common system that provides atomicity uh + + + align:start position:0% +common system that provides atomicity uh +one example is a database system now + + align:start position:0% +one example is a database system now + + + align:start position:0% +one example is a database system now +many many systems provide um atomicity + + align:start position:0% +many many systems provide um atomicity + + + align:start position:0% +many many systems provide um atomicity +for example your every computer does it + + align:start position:0% +for example your every computer does it + + + align:start position:0% +for example your every computer does it +in its instruction set you often want + + align:start position:0% +in its instruction set you often want + + + align:start position:0% +in its instruction set you often want +your instructions to from the point of + + align:start position:0% +your instructions to from the point of + + + align:start position:0% +your instructions to from the point of +view of the invoker of the instruction + + align:start position:0% +view of the invoker of the instruction + + + align:start position:0% +view of the invoker of the instruction +be Atomic um so we're going to be + + align:start position:0% +be Atomic um so we're going to be + + + align:start position:0% +be Atomic um so we're going to be +designing techniques that in general + + align:start position:0% +designing techniques that in general + + + align:start position:0% +designing techniques that in general +operate across the whole range of + + align:start position:0% +operate across the whole range of + + + align:start position:0% +operate across the whole range of +systems but database systems are of + + align:start position:0% +systems but database systems are of + + + align:start position:0% +systems but database systems are of +particular interest because they're very + + align:start position:0% +particular interest because they're very + + + align:start position:0% +particular interest because they're very +common and they exercise these Concepts + + align:start position:0% +common and they exercise these Concepts + + + align:start position:0% +common and they exercise these Concepts +um to to a high degree and two other + + align:start position:0% +um to to a high degree and two other + + + align:start position:0% +um to to a high degree and two other +Concepts that many systems provide the + + align:start position:0% +Concepts that many systems provide the + + + align:start position:0% +Concepts that many systems provide the +first one is + + align:start position:0% + + + + align:start position:0% + +consistency and it's unfortunate that + + align:start position:0% +consistency and it's unfortunate that + + + align:start position:0% +consistency and it's unfortunate that +the word consistency was previously used + + align:start position:0% +the word consistency was previously used + + + align:start position:0% +the word consistency was previously used +to some extent to mean isolated so it's + + align:start position:0% +to some extent to mean isolated so it's + + + align:start position:0% +to some extent to mean isolated so it's +important not to get into that confusion + + align:start position:0% +important not to get into that confusion + + + align:start position:0% +important not to get into that confusion +so in some old papers when you see + + align:start position:0% +so in some old papers when you see + + + align:start position:0% +so in some old papers when you see +consistent they you should really um + + align:start position:0% +consistent they you should really um + + + align:start position:0% +consistent they you should really um +realize you should realize that what + + align:start position:0% +realize you should realize that what + + + align:start position:0% +realize you should realize that what +they really are talking about is um + + align:start position:0% +they really are talking about is um + + + align:start position:0% +they really are talking about is um +isolated A1 before A2 or A2 before A1 + + align:start position:0% +isolated A1 before A2 or A2 before A1 + + + align:start position:0% +isolated A1 before A2 or A2 before A1 +but what we'll mean by consistency and + + align:start position:0% +but what we'll mean by consistency and + + + align:start position:0% +but what we'll mean by consistency and +we'll get into this next week is that + + align:start position:0% +we'll get into this next week is that + + + align:start position:0% +we'll get into this next week is that +there's some invariant for the + + align:start position:0% +there's some invariant for the + + + align:start position:0% +there's some invariant for the +application that's using um often using + + align:start position:0% +application that's using um often using + + + align:start position:0% +application that's using um often using +atomac City that's + + align:start position:0% +atomac City that's + + + align:start position:0% +atomac City that's +maintained for example in a in a banking + + align:start position:0% +maintained for example in a in a banking + + + align:start position:0% +maintained for example in a in a banking +application if you take the transfer + + align:start position:0% +application if you take the transfer + + + align:start position:0% +application if you take the transfer +examples isolated means that you want + + align:start position:0% +examples isolated means that you want + + + align:start position:0% +examples isolated means that you want +the result to be as if the transfer is + + align:start position:0% +the result to be as if the transfer is + + + align:start position:0% +the result to be as if the transfer is +ran in some serial order consistent + + align:start position:0% +ran in some serial order consistent + + + align:start position:0% +ran in some serial order consistent +means that there might be a higher level + + align:start position:0% +means that there might be a higher level + + + align:start position:0% +means that there might be a higher level +notion that the U designer of this + + align:start position:0% +notion that the U designer of this + + + align:start position:0% +notion that the U designer of this +banking application um might have wanted + + align:start position:0% +banking application um might have wanted + + + align:start position:0% +banking application um might have wanted +such as a bank might have a rule that + + align:start position:0% +such as a bank might have a rule that + + + align:start position:0% +such as a bank might have a rule that +says that at the end of each day um the + + align:start position:0% +says that at the end of each day um the + + + align:start position:0% +says that at the end of each day um the +checking account every checking account + + align:start position:0% +checking account every checking account + + + align:start position:0% +checking account every checking account +should be uh should have an amount + + align:start position:0% +should be uh should have an amount + + + align:start position:0% +should be uh should have an amount +that's at least 10% of every of the + + align:start position:0% +that's at least 10% of every of the + + + align:start position:0% +that's at least 10% of every of the +corresponding savings account now during + + align:start position:0% +corresponding savings account now during + + + align:start position:0% +corresponding savings account now during +the middle of the day there might be + + align:start position:0% +the middle of the day there might be + + + align:start position:0% +the middle of the day there might be +individual um you know there might be + + align:start position:0% +individual um you know there might be + + + align:start position:0% +individual um you know there might be +individual actions + + align:start position:0% +individual actions + + + align:start position:0% +individual actions +that transiently violate that that rule + + align:start position:0% +that transiently violate that that rule + + + align:start position:0% +that transiently violate that that rule +but at various points the designer might + + align:start position:0% +but at various points the designer might + + + align:start position:0% +but at various points the designer might +wish to ensure that the um you know a + + align:start position:0% +wish to ensure that the um you know a + + + align:start position:0% +wish to ensure that the um you know a +rule like the cons that that the + + align:start position:0% +rule like the cons that that the + + + align:start position:0% +rule like the cons that that the +checking account must have at least a + + align:start position:0% +checking account must have at least a + + + align:start position:0% +checking account must have at least a +certain amount of money some fra of the + + align:start position:0% +certain amount of money some fra of the + + + align:start position:0% +certain amount of money some fra of the +savings account or in some you know + + align:start position:0% +savings account or in some you know + + + align:start position:0% +savings account or in some you know +payroll application for a company um you + + align:start position:0% +payroll application for a company um you + + + align:start position:0% +payroll application for a company um you +know they're modifying the payroll and + + align:start position:0% +know they're modifying the payroll and + + + align:start position:0% +know they're modifying the payroll and +adding you know giving raises to various + + align:start position:0% +adding you know giving raises to various + + + align:start position:0% +adding you know giving raises to various +people but they might have a rule that + + align:start position:0% +people but they might have a rule that + + + align:start position:0% +people but they might have a rule that +says that you can give whatever raise + + align:start position:0% +says that you can give whatever raise + + + align:start position:0% +says that you can give whatever raise +you want but every manager must make at + + align:start position:0% +you want but every manager must make at + + + align:start position:0% +you want but every manager must make at +least 5% more than all of his or her + + align:start position:0% +least 5% more than all of his or her + + + align:start position:0% +least 5% more than all of his or her +direct reports so you might have a rule + + align:start position:0% +direct reports so you might have a rule + + + align:start position:0% +direct reports so you might have a rule +like that all of these are application + + align:start position:0% +like that all of these are application + + + align:start position:0% +like that all of these are application +Level invariants that correspond to the + + align:start position:0% +Level invariants that correspond to the + + + align:start position:0% +Level invariants that correspond to the +consistency of the data that's being + + align:start position:0% +consistency of the data that's being + + + align:start position:0% +consistency of the data that's being +maintained in this example in a database + + align:start position:0% +maintained in this example in a database + + + align:start position:0% +maintained in this example in a database +and uh you can use database systems to + + align:start position:0% +and uh you can use database systems to + + + align:start position:0% +and uh you can use database systems to +provide these rules these consistency + + align:start position:0% +provide these rules these consistency + + + align:start position:0% +provide these rules these consistency +rules but that's different from + + align:start position:0% +rules but that's different from + + + align:start position:0% +rules but that's different from +isolation isolation just describes the + + align:start position:0% +isolation isolation just describes the + + + align:start position:0% +isolation isolation just describes the +serial ordering in which oh sorry it + + align:start position:0% +serial ordering in which oh sorry it + + + align:start position:0% +serial ordering in which oh sorry it +just says that there has to be some + + align:start position:0% +just says that there has to be some + + + align:start position:0% +just says that there has to be some +serial equivalent serial ordering in + + align:start position:0% +serial equivalent serial ordering in + + + align:start position:0% +serial equivalent serial ordering in +which things things + + align:start position:0% +which things things + + + align:start position:0% +which things things +run and the fourth um property in + + align:start position:0% +run and the fourth um property in + + + align:start position:0% +run and the fourth um property in +addition to after recoverability + + align:start position:0% +addition to after recoverability + + + align:start position:0% +addition to after recoverability +isolation and consistency is + + align:start position:0% + + + + align:start position:0% + +durability durability basically says + + align:start position:0% +durability durability basically says + + + align:start position:0% +durability durability basically says +that the data should last for as long as + + align:start position:0% +that the data should last for as long as + + + align:start position:0% +that the data should last for as long as +um you know it depends on the it's an + + align:start position:0% +um you know it depends on the it's an + + + align:start position:0% +um you know it depends on the it's an +application specific con concept but + + align:start position:0% +application specific con concept but + + + align:start position:0% +application specific con concept but +what it says is the data must last uh + + align:start position:0% +what it says is the data must last uh + + + align:start position:0% +what it says is the data must last uh +for as long as some predefined um + + align:start position:0% +for as long as some predefined um + + + align:start position:0% +for as long as some predefined um +duration so for example you might store + + align:start position:0% +duration so for example you might store + + + align:start position:0% +duration so for example you might store +data in a database and you know in many + + align:start position:0% +data in a database and you know in many + + + align:start position:0% +data in a database and you know in many +databases you really want it to last + + align:start position:0% +databases you really want it to last + + + align:start position:0% +databases you really want it to last +quote forever but in reality nothing + + align:start position:0% +quote forever but in reality nothing + + + align:start position:0% +quote forever but in reality nothing +ever it's very hard to make things last + + align:start position:0% +ever it's very hard to make things last + + + align:start position:0% +ever it's very hard to make things last +forever uh so you might descri Define + + align:start position:0% +forever uh so you might descri Define + + + align:start position:0% +forever uh so you might descri Define +that the uh data in this database must + + align:start position:0% +that the uh data in this database must + + + align:start position:0% +that the uh data in this database must +last for three years and you work hard + + align:start position:0% +last for three years and you work hard + + + align:start position:0% +last for three years and you work hard +to preserve that or you might have an + + align:start position:0% +to preserve that or you might have an + + + align:start position:0% +to preserve that or you might have an +application that as long as the thread + + align:start position:0% +application that as long as the thread + + + align:start position:0% +application that as long as the thread +is running you want the data to last but + + align:start position:0% +is running you want the data to last but + + + align:start position:0% +is running you want the data to last but +after the thread um is terminated you + + align:start position:0% +after the thread um is terminated you + + + align:start position:0% +after the thread um is terminated you +don't actually care about the data and + + align:start position:0% +don't actually care about the data and + + + align:start position:0% +don't actually care about the data and +that's a different notion of durability + + align:start position:0% +that's a different notion of durability + + + align:start position:0% +that's a different notion of durability +but both of these have talk about the + + align:start position:0% +but both of these have talk about the + + + align:start position:0% +but both of these have talk about the +the lifetime with which you want to + + align:start position:0% +the lifetime with which you want to + + + align:start position:0% +the lifetime with which you want to +preserve + + align:start position:0% +preserve + + + align:start position:0% +preserve +data okay so now when you have a system + + align:start position:0% +data okay so now when you have a system + + + align:start position:0% +data okay so now when you have a system +that provides recoverability and + + align:start position:0% +that provides recoverability and + + + align:start position:0% +that provides recoverability and +isolation that is atomicity consistency + + align:start position:0% +isolation that is atomicity consistency + + + align:start position:0% +isolation that is atomicity consistency +and durability then we're going to call + + align:start position:0% +and durability then we're going to call + + + align:start position:0% +and durability then we're going to call +that a + + align:start position:0% +that a + + + align:start position:0% +that a +transaction so a set of actions that has + + align:start position:0% +transaction so a set of actions that has + + + align:start position:0% +transaction so a set of actions that has +an action that uh sorry a set of actions + + align:start position:0% +an action that uh sorry a set of actions + + + align:start position:0% +an action that uh sorry a set of actions +that Each of which is recoverable that + + align:start position:0% +that Each of which is recoverable that + + + align:start position:0% +that Each of which is recoverable that +are isolated from each other that has + + align:start position:0% +are isolated from each other that has + + + align:start position:0% +are isolated from each other that has +notion of consistency and can achieve it + + align:start position:0% +notion of consistency and can achieve it + + + align:start position:0% +notion of consistency and can achieve it +and where the data has durability um + + align:start position:0% +and where the data has durability um + + + align:start position:0% +and where the data has durability um +those actions are called + + align:start position:0% +those actions are called + + + align:start position:0% +those actions are called +transactions and many database systems + + align:start position:0% +transactions and many database systems + + + align:start position:0% +transactions and many database systems +work hard to provide transactions which + + align:start position:0% +work hard to provide transactions which + + + align:start position:0% +work hard to provide transactions which +means they provide all of these + + align:start position:0% +means they provide all of these + + + align:start position:0% +means they provide all of these +features but it's certainly possible and + + align:start position:0% +features but it's certainly possible and + + + align:start position:0% +features but it's certainly possible and +we'll look at many examples where you + + align:start position:0% +we'll look at many examples where you + + + align:start position:0% +we'll look at many examples where you +can just Design Systems that have just + + align:start position:0% +can just Design Systems that have just + + + align:start position:0% +can just Design Systems that have just +recoverability and + + align:start position:0% +recoverability and + + + align:start position:0% +recoverability and +isolation and we may not even worry + + align:start position:0% +isolation and we may not even worry + + + align:start position:0% +isolation and we may not even worry +about these other Notions and that's + + align:start position:0% +about these other Notions and that's + + + align:start position:0% +about these other Notions and that's +what we'll start with we don't want to + + align:start position:0% +what we'll start with we don't want to + + + align:start position:0% +what we'll start with we don't want to +solve all of the problems at once we + + align:start position:0% +solve all of the problems at once we + + + align:start position:0% +solve all of the problems at once we +start with the easier set of problems + + align:start position:0% +start with the easier set of problems + + + align:start position:0% +start with the easier set of problems +and then build from + + align:start position:0% + + + + align:start position:0% + +there I don't know what happened + + align:start position:0% +there I don't know what happened + + + align:start position:0% +there I don't know what happened +there + + align:start position:0% + + + + align:start position:0% + +okay okay so today and on Wednesday our + + align:start position:0% +okay okay so today and on Wednesday our + + + align:start position:0% +okay okay so today and on Wednesday our +plan is to come up with ways of + + align:start position:0% +plan is to come up with ways of + + + align:start position:0% +plan is to come up with ways of +achieving recoverability so that's what + + align:start position:0% +achieving recoverability so that's what + + + align:start position:0% +achieving recoverability so that's what +we're going to start doing + + align:start position:0% + + + + align:start position:0% + +so the general approach for how we're + + align:start position:0% +so the general approach for how we're + + + align:start position:0% +so the general approach for how we're +going to achieve recoverability of + + align:start position:0% +going to achieve recoverability of + + + align:start position:0% +going to achieve recoverability of +modules is and recall that the problem + + align:start position:0% +modules is and recall that the problem + + + align:start position:0% +modules is and recall that the problem +here is M2 fails and then M1 um somehow + + align:start position:0% +here is M2 fails and then M1 um somehow + + + align:start position:0% +here is M2 fails and then M1 um somehow +discovers its failure and then when it + + align:start position:0% +discovers its failure and then when it + + + align:start position:0% +discovers its failure and then when it +restarts you don't want any partial + + align:start position:0% +restarts you don't want any partial + + + align:start position:0% +restarts you don't want any partial +state to be kept so the general plan is + + align:start position:0% +state to be kept so the general plan is + + + align:start position:0% +state to be kept so the general plan is +to design modules to be fail + + align:start position:0% +to design modules to be fail + + + align:start position:0% +to design modules to be fail +fast so you need a way to discover that + + align:start position:0% +fast so you need a way to discover that + + + align:start position:0% +fast so you need a way to discover that +things are not working and that's the + + align:start position:0% +things are not working and that's the + + + align:start position:0% +things are not working and that's the +scope of the kinds of systems we're + + align:start position:0% +scope of the kinds of systems we're + + + align:start position:0% +scope of the kinds of systems we're +going to be dealing + + align:start position:0% +going to be dealing + + + align:start position:0% +going to be dealing +with and then once um the system failure + + align:start position:0% +with and then once um the system failure + + + align:start position:0% +with and then once um the system failure +is detected and then you restart the + + align:start position:0% +is detected and then you restart the + + + align:start position:0% +is detected and then you restart the +system or recovers um you're onun some + + align:start position:0% +system or recovers um you're onun some + + + align:start position:0% +system or recovers um you're onun some +kind of a repair + + align:start position:0% +kind of a repair + + + align:start position:0% +kind of a repair +procedure this is in general you're onun + + align:start position:0% +procedure this is in general you're onun + + + align:start position:0% +procedure this is in general you're onun +some kind of repair procedure um that + + align:start position:0% +some kind of repair procedure um that + + + align:start position:0% +some kind of repair procedure um that +allows you to recover allows the failed + + align:start position:0% +allows you to recover allows the failed + + + align:start position:0% +allows you to recover allows the failed +module to + + align:start position:0% +module to + + + align:start position:0% +module to +recover and then it + + align:start position:0% + + + + align:start position:0% + +restarts where restarts means it allows + + align:start position:0% +restarts where restarts means it allows + + + align:start position:0% +restarts where restarts means it allows +um M1 in this case allows invokers to + + align:start position:0% +um M1 in this case allows invokers to + + + align:start position:0% +um M1 in this case allows invokers to +start running on that system on that + + align:start position:0% +start running on that system on that + + + align:start position:0% +start running on that system on that +module + + align:start position:0% + + + + align:start position:0% + +so we're going to do this in three steps + + align:start position:0% +so we're going to do this in three steps + + + align:start position:0% +so we're going to do this in three steps +the first thing we're going to do is to + + align:start position:0% +the first thing we're going to do is to + + + align:start position:0% +the first thing we're going to do is to +look at a very specific special case of + + align:start position:0% +look at a very specific special case of + + + align:start position:0% +look at a very specific special case of +this problem which is um realize that + + align:start position:0% +this problem which is um realize that + + + align:start position:0% +this problem which is um realize that +all of these things having to do with + + align:start position:0% +all of these things having to do with + + + align:start position:0% +all of these things having to do with +partial State occur because there's some + + align:start position:0% +partial State occur because there's some + + + align:start position:0% +partial State occur because there's some +State once once a module has crashed + + align:start position:0% +State once once a module has crashed + + + align:start position:0% +State once once a module has crashed +there's some state that it has remaining + + align:start position:0% +there's some state that it has remaining + + + align:start position:0% +there's some state that it has remaining +so if it just recovered and started + + align:start position:0% +so if it just recovered and started + + + align:start position:0% +so if it just recovered and started +running again without doing something + + align:start position:0% +running again without doing something + + + align:start position:0% +running again without doing something +then that partial state is visible to uh + + align:start position:0% +then that partial state is visible to uh + + + align:start position:0% +then that partial state is visible to uh +the invoker of that + + align:start position:0% +the invoker of that + + + align:start position:0% +the invoker of that +module now if this state were all + + align:start position:0% +module now if this state were all + + + align:start position:0% +module now if this state were all +volatile State like in just you know RAM + + align:start position:0% +volatile State like in just you know RAM + + + align:start position:0% +volatile State like in just you know RAM +for example and a thread crashed and if + + align:start position:0% +for example and a thread crashed and if + + + align:start position:0% +for example and a thread crashed and if +it was in its virtual memory and the + + align:start position:0% +it was in its virtual memory and the + + + align:start position:0% +it was in its virtual memory and the +thread crashed and it recovered then you + + align:start position:0% +thread crashed and it recovered then you + + + align:start position:0% +thread crashed and it recovered then you +don't really have to worry about this + + align:start position:0% +don't really have to worry about this + + + align:start position:0% +don't really have to worry about this +because all of the state um anyway has + + align:start position:0% +because all of the state um anyway has + + + align:start position:0% +because all of the state um anyway has +gone + + align:start position:0% +gone + + + align:start position:0% +gone +away so primarily we're worried about + + align:start position:0% +away so primarily we're worried about + + + align:start position:0% +away so primarily we're worried about +state that lasts uh across + + align:start position:0% +state that lasts uh across + + + align:start position:0% +state that lasts uh across +failures and concretely um an example of + + align:start position:0% +failures and concretely um an example of + + + align:start position:0% +failures and concretely um an example of +that concretely is state that that's + + align:start position:0% +that concretely is state that that's + + + align:start position:0% +that concretely is state that that's +maintained um on dis just as a concrete + + align:start position:0% +maintained um on dis just as a concrete + + + align:start position:0% +maintained um on dis just as a concrete +example so we're going to start first by + + align:start position:0% +example so we're going to start first by + + + align:start position:0% +example so we're going to start first by +um obtaining a coverable + + align:start position:0% + + + + align:start position:0% + +sector but basically coming up with a + + align:start position:0% +sector but basically coming up with a + + + align:start position:0% +sector but basically coming up with a +scheme that allows us to do reads and + + align:start position:0% +scheme that allows us to do reads and + + + align:start position:0% +scheme that allows us to do reads and +writes of a single sector of a dis in a + + align:start position:0% +writes of a single sector of a dis in a + + + align:start position:0% +writes of a single sector of a dis in a +recoverable way so we're going to Define + + align:start position:0% +recoverable way so we're going to Define + + + align:start position:0% +recoverable way so we're going to Define +two procedures a recoverable put that + + align:start position:0% +two procedures a recoverable put that + + + align:start position:0% +two procedures a recoverable put that +allows you to put stuff write stuff onto + + align:start position:0% +allows you to put stuff write stuff onto + + + align:start position:0% +allows you to put stuff write stuff onto +a single sector of a disk and a + + align:start position:0% +a single sector of a disk and a + + + align:start position:0% +a single sector of a disk and a +recoverable get that allows you to read + + align:start position:0% +recoverable get that allows you to read + + + align:start position:0% +recoverable get that allows you to read +stuff off of off of a single sector of a + + align:start position:0% +stuff off of off of a single sector of a + + + align:start position:0% +stuff off of off of a single sector of a +disk in a way that um is is recoverable + + align:start position:0% +disk in a way that um is is recoverable + + + align:start position:0% +disk in a way that um is is recoverable +and the general and the hard problem + + align:start position:0% +and the general and the hard problem + + + align:start position:0% +and the general and the hard problem +here is going to be that as the system + + align:start position:0% +here is going to be that as the system + + + align:start position:0% +here is going to be that as the system +sys crashing um for a variety of reasons + + align:start position:0% +sys crashing um for a variety of reasons + + + align:start position:0% +sys crashing um for a variety of reasons +bad data might get written on to a Bas + + align:start position:0% +bad data might get written on to a Bas + + + align:start position:0% +bad data might get written on to a Bas +to a sector so if you just took a + + align:start position:0% +to a sector so if you just took a + + + align:start position:0% +to a sector so if you just took a +regular sector of your disc um you know + + align:start position:0% +regular sector of your disc um you know + + + align:start position:0% +regular sector of your disc um you know +as you know let's say that someone you + + align:start position:0% +as you know let's say that someone you + + + align:start position:0% +as you know let's say that someone you +know this the operating system is trying + + align:start position:0% +know this the operating system is trying + + + align:start position:0% +know this the operating system is trying +to write something into a dis sector + + align:start position:0% +to write something into a dis sector + + + align:start position:0% +to write something into a dis sector +somebody turns off the power and random + + align:start position:0% +somebody turns off the power and random + + + align:start position:0% +somebody turns off the power and random +stuff might get just written out onto + + align:start position:0% +stuff might get just written out onto + + + align:start position:0% +stuff might get just written out onto +the + + align:start position:0% +the + + + align:start position:0% +the +dis and so when the system comes back up + + align:start position:0% +dis and so when the system comes back up + + + align:start position:0% +dis and so when the system comes back up +the reader of that sector might get some + + align:start position:0% +the reader of that sector might get some + + + align:start position:0% +the reader of that sector might get some +garbage value some result of some + + align:start position:0% +garbage value some result of some + + + align:start position:0% +garbage value some result of some +partial right so that's what we're going + + align:start position:0% +partial right so that's what we're going + + + align:start position:0% +partial right so that's what we're going +to try to avoid so we'll do that first + + align:start position:0% +to try to avoid so we'll do that first + + + align:start position:0% +to try to avoid so we'll do that first +and then what we'll do and and and + + align:start position:0% +and then what we'll do and and and + + + align:start position:0% +and then what we'll do and and and +that's for next time to complete the + + align:start position:0% +that's for next time to complete the + + + align:start position:0% +that's for next time to complete the +story recoverability story we're going + + align:start position:0% +story recoverability story we're going + + + align:start position:0% +story recoverability story we're going +to use this solution as a bootstrap to + + align:start position:0% +to use this solution as a bootstrap to + + + align:start position:0% +to use this solution as a bootstrap to +as as a building block for a more + + align:start position:0% +as as a building block for a more + + + align:start position:0% +as as a building block for a more +General solution because it's not going + + align:start position:0% +General solution because it's not going + + + align:start position:0% +General solution because it's not going +to be enough for us to just be able to + + align:start position:0% +to be enough for us to just be able to + + + align:start position:0% +to be enough for us to just be able to +read and write single sectors in a + + align:start position:0% +read and write single sectors in a + + + align:start position:0% +read and write single sectors in a +recoverable way because you know how + + align:start position:0% +recoverable way because you know how + + + align:start position:0% +recoverable way because you know how +many applications use only one sector of + + align:start position:0% +many applications use only one sector of + + + align:start position:0% +many applications use only one sector of +a dis what you'd like to do is to make + + align:start position:0% +a dis what you'd like to do is to make + + + align:start position:0% +a dis what you'd like to do is to make +sure that you have a general solution + + align:start position:0% +sure that you have a general solution + + + align:start position:0% +sure that you have a general solution +that works across all of the data that's + + align:start position:0% +that works across all of the data that's + + + align:start position:0% +that works across all of the data that's +being written and read so we're going to + + align:start position:0% +being written and read so we're going to + + + align:start position:0% +being written and read so we're going to +use that to come up with two schemes the + + align:start position:0% +use that to come up with two schemes the + + + align:start position:0% +use that to come up with two schemes the +first scheme + + align:start position:0% +first scheme + + + align:start position:0% +first scheme +uh is uses an idea called a version + + align:start position:0% + + + + align:start position:0% + +history and the second + + align:start position:0% +history and the second + + + align:start position:0% +history and the second +scheme um uses an idea called log + + align:start position:0% +scheme um uses an idea called log + + + align:start position:0% +scheme um uses an idea called log +logging using logs and both of these + + align:start position:0% +logging using logs and both of these + + + align:start position:0% +logging using logs and both of these +schemes have uh will turn out to be very + + align:start position:0% +schemes have uh will turn out to be very + + + align:start position:0% +schemes have uh will turn out to be very +general and useful and work but both of + + align:start position:0% +general and useful and work but both of + + + align:start position:0% +general and useful and work but both of +these scheme basically will use um this + + align:start position:0% +these scheme basically will use um this + + + align:start position:0% +these scheme basically will use um this +technique as a bootstrapping + + align:start position:0% +technique as a bootstrapping + + + align:start position:0% +technique as a bootstrapping +technique okay and so we need a solution + + align:start position:0% +technique okay and so we need a solution + + + align:start position:0% +technique okay and so we need a solution +here anyway because we're going to build + + align:start position:0% +here anyway because we're going to build + + + align:start position:0% +here anyway because we're going to build +on that to develop a more sophisticated + + align:start position:0% +on that to develop a more sophisticated + + + align:start position:0% +on that to develop a more sophisticated +solution for the general case + + align:start position:0% +solution for the general case + + + align:start position:0% +solution for the general case +and so today we're going to start with + + align:start position:0% +and so today we're going to start with + + + align:start position:0% +and so today we're going to start with +the special case um a because it's a + + align:start position:0% +the special case um a because it's a + + + align:start position:0% +the special case um a because it's a +building block and B because it'll turn + + align:start position:0% +building block and B because it'll turn + + + align:start position:0% +building block and B because it'll turn +out to show us a rule that we're going + + align:start position:0% +out to show us a rule that we're going + + + align:start position:0% +out to show us a rule that we're going +to religiously follow in coming up with + + align:start position:0% +to religiously follow in coming up with + + + align:start position:0% +to religiously follow in coming up with +Solutions systematic solutions for these + + align:start position:0% +Solutions systematic solutions for these + + + align:start position:0% +Solutions systematic solutions for these +more General uh to to work in the most + + align:start position:0% +more General uh to to work in the most + + + align:start position:0% +more General uh to to work in the most +more General case when you have more + + align:start position:0% +more General case when you have more + + + align:start position:0% +more General case when you have more +than one sector being read or + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +written so let's write out um the + + align:start position:0% +written so let's write out um the + + + align:start position:0% +written so let's write out um the +assumptions and the model here for the + + align:start position:0% +assumptions and the model here for the + + + align:start position:0% +assumptions and the model here for the +solution + + align:start position:0% +solution + + + align:start position:0% +solution +the first assumption we're going to make + + align:start position:0% +the first assumption we're going to make + + + align:start position:0% +the first assumption we're going to make +since we're dealing with recoverability + + align:start position:0% +since we're dealing with recoverability + + + align:start position:0% +since we're dealing with recoverability +and not with isolation we're going to + + align:start position:0% +and not with isolation we're going to + + + align:start position:0% +and not with isolation we're going to +deal with isolation next week the first + + align:start position:0% +deal with isolation next week the first + + + align:start position:0% +deal with isolation next week the first +assumption we'll make is that there's no + + align:start position:0% + + + + align:start position:0% + +concurrency and we come up with + + align:start position:0% +concurrency and we come up with + + + align:start position:0% +concurrency and we come up with +different solutions for dealing with + + align:start position:0% +different solutions for dealing with + + + align:start position:0% +different solutions for dealing with +people concurrently trying to write uh + + align:start position:0% +people concurrently trying to write uh + + + align:start position:0% +people concurrently trying to write uh +the same + + align:start position:0% + + + + align:start position:0% + +sector we'll also assume um and this is + + align:start position:0% +sector we'll also assume um and this is + + + align:start position:0% +sector we'll also assume um and this is +an assumption we'll revisit in a couple + + align:start position:0% +an assumption we'll revisit in a couple + + + align:start position:0% +an assumption we'll revisit in a couple +of weeks to show you how to actually um + + align:start position:0% +of weeks to show you how to actually um + + + align:start position:0% +of weeks to show you how to actually um +achieve this goal but we'll assume that + + align:start position:0% +achieve this goal but we'll assume that + + + align:start position:0% +achieve this goal but we'll assume that +there's no Hardware + + align:start position:0% + + + + align:start position:0% + +failures there's no Hardware + + align:start position:0% + + + + align:start position:0% + +errors so for example and the appendix + + align:start position:0% +errors so for example and the appendix + + + align:start position:0% +errors so for example and the appendix +to chapter 8 which we'll actually we + + align:start position:0% +to chapter 8 which we'll actually we + + + align:start position:0% +to chapter 8 which we'll actually we +we'll assign uh for reading later on uh + + align:start position:0% +we'll assign uh for reading later on uh + + + align:start position:0% +we'll assign uh for reading later on uh +in the semester um actually shows two + + align:start position:0% +in the semester um actually shows two + + + align:start position:0% +in the semester um actually shows two +methods careful put and careful get um + + align:start position:0% +methods careful put and careful get um + + + align:start position:0% +methods careful put and careful get um +that actually deal with a variety of + + align:start position:0% +that actually deal with a variety of + + + align:start position:0% +that actually deal with a variety of +Hardware problems so for example every + + align:start position:0% +Hardware problems so for example every + + + align:start position:0% +Hardware problems so for example every +sector has a dis checks them a sector + + align:start position:0% +sector has a dis checks them a sector + + + align:start position:0% +sector has a dis checks them a sector +checks them on it so if you wrote bad + + align:start position:0% +checks them on it so if you wrote bad + + + align:start position:0% +checks them on it so if you wrote bad +data um and something happened in the + + align:start position:0% +data um and something happened in the + + + align:start position:0% +data um and something happened in the +middle of that right um and then someone + + align:start position:0% +middle of that right um and then someone + + + align:start position:0% +middle of that right um and then someone +went back and read that sector they + + align:start position:0% +went back and read that sector they + + + align:start position:0% +went back and read that sector they +would discover that it's bad because the + + align:start position:0% +would discover that it's bad because the + + + align:start position:0% +would discover that it's bad because the +check sum wouldn't + + align:start position:0% +check sum wouldn't + + + align:start position:0% +check sum wouldn't +match now the appendix to this chapter + + align:start position:0% +match now the appendix to this chapter + + + align:start position:0% +match now the appendix to this chapter +9B has a more careful description of how + + align:start position:0% +9B has a more careful description of how + + + align:start position:0% +9B has a more careful description of how +you deal with a variety of Errors so + + align:start position:0% +you deal with a variety of Errors so + + + align:start position:0% +you deal with a variety of Errors so +that you can achieve this careful put + + align:start position:0% +that you can achieve this careful put + + + align:start position:0% +that you can achieve this careful put +and careful get of a dis + + align:start position:0% +and careful get of a dis + + + align:start position:0% +and careful get of a dis +sector so assume for now that there are + + align:start position:0% +sector so assume for now that there are + + + align:start position:0% +sector so assume for now that there are +no Hardware errors there's no decay of + + align:start position:0% +no Hardware errors there's no decay of + + + align:start position:0% +no Hardware errors there's no decay of +data on the disk and so on it'll turn + + align:start position:0% +data on the disk and so on it'll turn + + + align:start position:0% +data on the disk and so on it'll turn +out the problem is still interesting + + align:start position:0% +out the problem is still interesting + + + align:start position:0% +out the problem is still interesting +that it's not easy to achieve um a + + align:start position:0% +that it's not easy to achieve um a + + + align:start position:0% +that it's not easy to achieve um a +recoverable put and get even though the + + align:start position:0% +recoverable put and get even though the + + + align:start position:0% +recoverable put and get even though the +hardware is fine and that's because + + align:start position:0% +hardware is fine and that's because + + + align:start position:0% +hardware is fine and that's because +there are software + + align:start position:0% + + + + align:start position:0% + +errors and in particular um the model + + align:start position:0% +errors and in particular um the model + + + align:start position:0% +errors and in particular um the model +here is that you have some application + + align:start position:0% +here is that you have some application + + + align:start position:0% +here is that you have some application +then you have the operating system and + + align:start position:0% +then you have the operating system and + + + align:start position:0% +then you have the operating system and +the operating system has a buffer + + align:start position:0% +the operating system has a buffer + + + align:start position:0% +the operating system has a buffer +here of data that it's waiting to write + + align:start position:0% +here of data that it's waiting to write + + + align:start position:0% +here of data that it's waiting to write +onto disk + + align:start position:0% +onto disk + + + align:start position:0% +onto disk +then you have a + + align:start position:0% + + + + align:start position:0% + +dis and that's a dis sector the problem + + align:start position:0% +dis and that's a dis sector the problem + + + align:start position:0% +dis and that's a dis sector the problem +might be that if when as a failure + + align:start position:0% +might be that if when as a failure + + + align:start position:0% +might be that if when as a failure +occurs there's something that happens an + + align:start position:0% +occurs there's something that happens an + + + align:start position:0% +occurs there's something that happens an +error something that gets triggered in + + align:start position:0% +error something that gets triggered in + + + align:start position:0% +error something that gets triggered in +the operating system so the buffer gets + + align:start position:0% +the operating system so the buffer gets + + + align:start position:0% +the operating system so the buffer gets +corrupted and then there's some bad data + + align:start position:0% +corrupted and then there's some bad data + + + align:start position:0% +corrupted and then there's some bad data +that gets written out onto this sector + + align:start position:0% +that gets written out onto this sector + + + align:start position:0% +that gets written out onto this sector +and that's the kind of problem that we + + align:start position:0% +and that's the kind of problem that we + + + align:start position:0% +and that's the kind of problem that we +want to protect against it's not I mean + + align:start position:0% +want to protect against it's not I mean + + + align:start position:0% +want to protect against it's not I mean +so the fact that your Hardware is + + align:start position:0% +so the fact that your Hardware is + + + align:start position:0% +so the fact that your Hardware is +perfect doesn't actually solve this + + align:start position:0% +perfect doesn't actually solve this + + + align:start position:0% +perfect doesn't actually solve this +problem because this buffer itself has + + align:start position:0% +problem because this buffer itself has + + + align:start position:0% +problem because this buffer itself has +been corrupted or something happens + + align:start position:0% +been corrupted or something happens + + + align:start position:0% +been corrupted or something happens +during the process of this buffer to the + + align:start position:0% +during the process of this buffer to the + + + align:start position:0% +during the process of this buffer to the +sector so the data itself is bad and + + align:start position:0% +sector so the data itself is bad and + + + align:start position:0% +sector so the data itself is bad and +that's what we want to protect + + align:start position:0% + + + + align:start position:0% + +against so we're going to build on + + align:start position:0% +against so we're going to build on + + + align:start position:0% +against so we're going to build on +something that I've already talked about + + align:start position:0% +something that I've already talked about + + + align:start position:0% +something that I've already talked about +we're going to build on two + + align:start position:0% +we're going to build on two + + + align:start position:0% +we're going to build on two +procedures careful + + align:start position:0% +procedures careful + + + align:start position:0% +procedures careful +put um that puts to a sector it puts + + align:start position:0% +put um that puts to a sector it puts + + + align:start position:0% +put um that puts to a sector it puts +some + + align:start position:0% +some + + + align:start position:0% +some +data and the corresponding careful + + align:start position:0% +data and the corresponding careful + + + align:start position:0% +data and the corresponding careful +get which reads from a sector and + + align:start position:0% +get which reads from a sector and + + + align:start position:0% +get which reads from a sector and +Returns the data that's on that sector + + align:start position:0% +Returns the data that's on that sector + + + align:start position:0% +Returns the data that's on that sector +and the assumption is that careful put + + align:start position:0% +and the assumption is that careful put + + + align:start position:0% +and the assumption is that careful put +in get once you give it some data there + + align:start position:0% +in get once you give it some data there + + + align:start position:0% +in get once you give it some data there +are no Hardware failures for you to + + align:start position:0% +are no Hardware failures for you to + + + align:start position:0% +are no Hardware failures for you to +worry about + + align:start position:0% + + + + align:start position:0% + +anymore so the solution we're going to + + align:start position:0% +anymore so the solution we're going to + + + align:start position:0% +anymore so the solution we're going to +take to this problem is to realize that + + align:start position:0% +take to this problem is to realize that + + + align:start position:0% +take to this problem is to realize that +when a failure happens for example + + align:start position:0% +when a failure happens for example + + + align:start position:0% +when a failure happens for example +somebody you know turns off power switch + + align:start position:0% +somebody you know turns off power switch + + + align:start position:0% +somebody you know turns off power switch +and this buffer gets + + align:start position:0% +and this buffer gets + + + align:start position:0% +and this buffer gets +corrupted when the operating system does + + align:start position:0% +corrupted when the operating system does + + + align:start position:0% +corrupted when the operating system does +a right to that sector the sector might + + align:start position:0% +a right to that sector the sector might + + + align:start position:0% +a right to that sector the sector might +be left in a state which doesn't + + align:start position:0% +be left in a state which doesn't + + + align:start position:0% +be left in a state which doesn't +actually correspond to the data that was + + align:start position:0% +actually correspond to the data that was + + + align:start position:0% +actually correspond to the data that was +intended to be put onto that sector and + + align:start position:0% +intended to be put onto that sector and + + + align:start position:0% +intended to be put onto that sector and +so when the system recovers you're sort + + align:start position:0% +so when the system recovers you're sort + + + align:start position:0% +so when the system recovers you're sort +of stuck because this data in the sector + + align:start position:0% +of stuck because this data in the sector + + + align:start position:0% +of stuck because this data in the sector +contains some values in it that don't + + align:start position:0% +contains some values in it that don't + + + align:start position:0% +contains some values in it that don't +actually correspond to any actual um + + align:start position:0% +actually correspond to any actual um + + + align:start position:0% +actually correspond to any actual um +intended uh put of the data any intended + + align:start position:0% +intended uh put of the data any intended + + + align:start position:0% +intended uh put of the data any intended +right of the data + + align:start position:0% +right of the data + + + align:start position:0% +right of the data +so what this suggests is that a solution + + align:start position:0% +so what this suggests is that a solution + + + align:start position:0% +so what this suggests is that a solution +to this + + align:start position:0% +to this + + + align:start position:0% +to this +problem must involve a copy of some kind + + align:start position:0% +problem must involve a copy of some kind + + + align:start position:0% +problem must involve a copy of some kind +you you must make sure that if you have + + align:start position:0% +you you must make sure that if you have + + + align:start position:0% +you you must make sure that if you have +just one copy of the data and you write + + align:start position:0% +just one copy of the data and you write + + + align:start position:0% +just one copy of the data and you write +to it and something fails in the middle + + align:start position:0% +to it and something fails in the middle + + + align:start position:0% +to it and something fails in the middle +and you don't have a plan to back out to + + align:start position:0% +and you don't have a plan to back out to + + + align:start position:0% +and you don't have a plan to back out to +a an earlier working version that was + + align:start position:0% +a an earlier working version that was + + + align:start position:0% +a an earlier working version that was +correct you're stuck so that suggests + + align:start position:0% +correct you're stuck so that suggests + + + align:start position:0% +correct you're stuck so that suggests +that we better have a solution that + + align:start position:0% +that we better have a solution that + + + align:start position:0% +that we better have a solution that +involves a copy of + + align:start position:0% +involves a copy of + + + align:start position:0% +involves a copy of +data and later on we'll see how to + + align:start position:0% +data and later on we'll see how to + + + align:start position:0% +data and later on we'll see how to +system systematically develop a rule + + align:start position:0% +system systematically develop a rule + + + align:start position:0% +system systematically develop a rule +based on + + align:start position:0% + + + + align:start position:0% + +this so the inter the idea here is is + + align:start position:0% +this so the inter the idea here is is + + + align:start position:0% +this so the inter the idea here is is +very simple the way we're going to + + align:start position:0% +very simple the way we're going to + + + align:start position:0% +very simple the way we're going to +achieve recoverable put and recoverable + + align:start position:0% +achieve recoverable put and recoverable + + + align:start position:0% +achieve recoverable put and recoverable +get of a sector is actually + + align:start position:0% +get of a sector is actually + + + align:start position:0% +get of a sector is actually +to build a sector a single sector + + align:start position:0% +to build a sector a single sector + + + align:start position:0% +to build a sector a single sector +recoverable sector out of three sectors + + align:start position:0% +recoverable sector out of three sectors + + + align:start position:0% +recoverable sector out of three sectors +the first sector here is going to have + + align:start position:0% +the first sector here is going to have + + + align:start position:0% +the first sector here is going to have +one copy of the data the second sector + + align:start position:0% +one copy of the data the second sector + + + align:start position:0% +one copy of the data the second sector +is going to have another copy of the + + align:start position:0% +is going to have another copy of the + + + align:start position:0% +is going to have another copy of the +data and we're going to have a third + + align:start position:0% +data and we're going to have a third + + + align:start position:0% +data and we're going to have a third +sector here which is going to act as a + + align:start position:0% +sector here which is going to act as a + + + align:start position:0% +sector here which is going to act as a +flag um that allows us to choose one ver + + align:start position:0% +flag um that allows us to choose one ver + + + align:start position:0% +flag um that allows us to choose one ver +one version or the other version so let + + align:start position:0% +one version or the other version so let + + + align:start position:0% +one version or the other version so let +me call this d0 let me call this D1 and + + align:start position:0% +me call this d0 let me call this D1 and + + + align:start position:0% +me call this d0 let me call this D1 and +let me call + + align:start position:0% +let me call + + + align:start position:0% +let me call +this the + + align:start position:0% + + + + align:start position:0% + +Chooser so assume that at some point in + + align:start position:0% +Chooser so assume that at some point in + + + align:start position:0% +Chooser so assume that at some point in +time d0 has proper data on it okay so + + align:start position:0% +time d0 has proper data on it okay so + + + align:start position:0% +time d0 has proper data on it okay so +the idea now is going to be that anybody + + align:start position:0% +the idea now is going to be that anybody + + + align:start position:0% +the idea now is going to be that anybody +reading it the Chooser is going to + + align:start position:0% +reading it the Chooser is going to + + + align:start position:0% +reading it the Chooser is going to +contain the value zero in it okay now + + align:start position:0% +contain the value zero in it okay now + + + align:start position:0% +contain the value zero in it okay now +anybody reading is going to read from d0 + + align:start position:0% +anybody reading is going to read from d0 + + + align:start position:0% +anybody reading is going to read from d0 +anybody writing um in recoverable put is + + align:start position:0% +anybody writing um in recoverable put is + + + align:start position:0% +anybody writing um in recoverable put is +not allowed to write to d0 because + + align:start position:0% +not allowed to write to d0 because + + + align:start position:0% +not allowed to write to d0 because +that's what people are reading from + + align:start position:0% +that's what people are reading from + + + align:start position:0% +that's what people are reading from +instead they will write to D1 when the + + align:start position:0% +instead they will write to D1 when the + + + align:start position:0% +instead they will write to D1 when the +Chooser value is zero they will start + + align:start position:0% +Chooser value is zero they will start + + + align:start position:0% +Chooser value is zero they will start +writing in to + + align:start position:0% +writing in to + + + align:start position:0% +writing in to +D1 the plan is going to be that if that + + align:start position:0% +D1 the plan is going to be that if that + + + align:start position:0% +D1 the plan is going to be that if that +right succeeds properly then what we'll + + align:start position:0% +right succeeds properly then what we'll + + + align:start position:0% +right succeeds properly then what we'll +do is go ahead and change the Chooser + + align:start position:0% +do is go ahead and change the Chooser + + + align:start position:0% +do is go ahead and change the Chooser +from zero to a + + align:start position:0% +from zero to a + + + align:start position:0% +from zero to a +one okay and then people will start + + align:start position:0% +one okay and then people will start + + + align:start position:0% +one okay and then people will start +reading from one but if that right were + + align:start position:0% +reading from one but if that right were + + + align:start position:0% +reading from one but if that right were +to fail in the middle the power fails or + + align:start position:0% +to fail in the middle the power fails or + + + align:start position:0% +to fail in the middle the power fails or +something like that that D1 will be left + + align:start position:0% +something like that that D1 will be left + + + align:start position:0% +something like that that D1 will be left +in a in sort of a weird intermediate + + align:start position:0% +in a in sort of a weird intermediate + + + align:start position:0% +in a in sort of a weird intermediate +state but that's okay because nobody's + + align:start position:0% +state but that's okay because nobody's + + + align:start position:0% +state but that's okay because nobody's +really going to be reading from D1 + + align:start position:0% +really going to be reading from D1 + + + align:start position:0% +really going to be reading from D1 +they're all going to be reading from d0 + + align:start position:0% +they're all going to be reading from d0 + + + align:start position:0% +they're all going to be reading from d0 +because the Chooser hasn't yet been + + align:start position:0% +because the Chooser hasn't yet been + + + align:start position:0% +because the Chooser hasn't yet been +changed so the only other thing we have + + align:start position:0% +changed so the only other thing we have + + + align:start position:0% +changed so the only other thing we have +to worry about is now we're okay as long + + align:start position:0% +to worry about is now we're okay as long + + + align:start position:0% +to worry about is now we're okay as long +as the failure happens you know if the + + align:start position:0% +as the failure happens you know if the + + + align:start position:0% +as the failure happens you know if the +failure happens in the middle here + + align:start position:0% +failure happens in the middle here + + + align:start position:0% +failure happens in the middle here +somewhere where we're writing D1 we're + + align:start position:0% +somewhere where we're writing D1 we're + + + align:start position:0% +somewhere where we're writing D1 we're +okay because we haven't touched the + + align:start position:0% +okay because we haven't touched the + + + align:start position:0% +okay because we haven't touched the +Chooser if the failure happens at the + + align:start position:0% +Chooser if the failure happens at the + + + align:start position:0% +Chooser if the failure happens at the +end of writing D1 so we've written D1 + + align:start position:0% +end of writing D1 so we've written D1 + + + align:start position:0% +end of writing D1 so we've written D1 +and then we haven't yet started writing + + align:start position:0% +and then we haven't yet started writing + + + align:start position:0% +and then we haven't yet started writing +the Chooser and a failure happens here + + align:start position:0% +the Chooser and a failure happens here + + + align:start position:0% +the Chooser and a failure happens here +we're still okay because everybody will + + align:start position:0% +we're still okay because everybody will + + + align:start position:0% +we're still okay because everybody will +be reading from zero and that isn't + + align:start position:0% +be reading from zero and that isn't + + + align:start position:0% +be reading from zero and that isn't +going to have garbage in it it's it's + + align:start position:0% +going to have garbage in it it's it's + + + align:start position:0% +going to have garbage in it it's it's +not going to have the latest value in it + + align:start position:0% +not going to have the latest value in it + + + align:start position:0% +not going to have the latest value in it +but that's okay we never said that we + + align:start position:0% +but that's okay we never said that we + + + align:start position:0% +but that's okay we never said that we +should see the latest value um for a + + align:start position:0% +should see the latest value um for a + + + align:start position:0% +should see the latest value um for a +coverability to hold it's going to be + + align:start position:0% +coverability to hold it's going to be + + + align:start position:0% +coverability to hold it's going to be +okay for us to be reading from d0 and + + align:start position:0% +okay for us to be reading from d0 and + + + align:start position:0% +okay for us to be reading from d0 and +we'll continue to read from + + align:start position:0% +we'll continue to read from + + + align:start position:0% +we'll continue to read from +d0 and really the correctness of this + + align:start position:0% +d0 and really the correctness of this + + + align:start position:0% +d0 and really the correctness of this +boils down to understanding what will + + align:start position:0% +boils down to understanding what will + + + align:start position:0% +boils down to understanding what will +happen when a failure happens during the + + align:start position:0% +happen when a failure happens during the + + + align:start position:0% +happen when a failure happens during the +middle of writing this sector you're + + align:start position:0% +middle of writing this sector you're + + + align:start position:0% +middle of writing this sector you're +starting to write the Chooser sector and + + align:start position:0% +starting to write the Chooser sector and + + + align:start position:0% +starting to write the Chooser sector and +the system fails and we're don't have to + + align:start position:0% +the system fails and we're don't have to + + + align:start position:0% +the system fails and we're don't have to +worry about that because now we've + + align:start position:0% +worry about that because now we've + + + align:start position:0% +worry about that because now we've +written D1 completely and a failure + + align:start position:0% +written D1 completely and a failure + + + align:start position:0% +written D1 completely and a failure +happens in the middle of + + align:start position:0% +happens in the middle of + + + align:start position:0% +happens in the middle of +that so to understand that uh we'll get + + align:start position:0% +that so to understand that uh we'll get + + + align:start position:0% +that so to understand that uh we'll get +back to understanding the correctness of + + align:start position:0% +back to understanding the correctness of + + + align:start position:0% +back to understanding the correctness of +it but it helps to see what the pseudo + + align:start position:0% +it but it helps to see what the pseudo + + + align:start position:0% +it but it helps to see what the pseudo +code looks + + align:start position:0% + + + + align:start position:0% + +like so that's what put looks + + align:start position:0% +like so that's what put looks + + + align:start position:0% +like so that's what put looks +like um to do a put you first read the + + align:start position:0% +like um to do a put you first read the + + + align:start position:0% +like um to do a put you first read the +Chooser sector and then you put into the + + align:start position:0% +Chooser sector and then you put into the + + + align:start position:0% +Chooser sector and then you put into the +other place + + align:start position:0% + + + + align:start position:0% + +so this which here is the thing that + + align:start position:0% +so this which here is the thing that + + + align:start position:0% +so this which here is the thing that +tells you what the value of the Chooser + + align:start position:0% +tells you what the value of the Chooser + + + align:start position:0% +tells you what the value of the Chooser +sector is so it tells you which of the + + align:start position:0% +sector is so it tells you which of the + + + align:start position:0% +sector is so it tells you which of the +two um copies to write into and then + + align:start position:0% +two um copies to write into and then + + + align:start position:0% +two um copies to write into and then +after you do the um careful put if which + + align:start position:0% +after you do the um careful put if which + + + align:start position:0% +after you do the um careful put if which +is zero you put it to one if uh which is + + align:start position:0% +is zero you put it to one if uh which is + + + align:start position:0% +is zero you put it to one if uh which is +one you put it into zero and after that + + align:start position:0% +one you put it into zero and after that + + + align:start position:0% +one you put it into zero and after that +you twiddle the bit and then you do a + + align:start position:0% +you twiddle the bit and then you do a + + + align:start position:0% +you twiddle the bit and then you do a +put onto onto the Chooser sector the get + + align:start position:0% +put onto onto the Chooser sector the get + + + align:start position:0% +put onto onto the Chooser sector the get +is actually easier you just look at what + + align:start position:0% +is actually easier you just look at what + + + align:start position:0% +is actually easier you just look at what +the value is of the Chooser sector and + + align:start position:0% +the value is of the Chooser sector and + + + align:start position:0% +the value is of the Chooser sector and +then um get it from the corresponding + + align:start position:0% +then um get it from the corresponding + + + align:start position:0% +then um get it from the corresponding +place now there's a line here the second + + align:start position:0% +place now there's a line here the second + + + align:start position:0% +place now there's a line here the second +line of the pseudo code which says if + + align:start position:0% +line of the pseudo code which says if + + + align:start position:0% +line of the pseudo code which says if +state is not okay so if stateus not okay + + align:start position:0% +state is not okay so if stateus not okay + + + align:start position:0% +state is not okay so if stateus not okay +is the key thing if stateus not okay is + + align:start position:0% +is the key thing if stateus not okay is + + + align:start position:0% +is the key thing if stateus not okay is +what happens when a failure happens in + + align:start position:0% +what happens when a failure happens in + + + align:start position:0% +what happens when a failure happens in +the middle of writing the Chooser sector + + align:start position:0% +the middle of writing the Chooser sector + + + align:start position:0% +the middle of writing the Chooser sector +so let's say a failure happens on this + + align:start position:0% +so let's say a failure happens on this + + + align:start position:0% +so let's say a failure happens on this +pseudo code um I already explained why + + align:start position:0% +pseudo code um I already explained why + + + align:start position:0% +pseudo code um I already explained why +there's no problem if a failure happens + + align:start position:0% +there's no problem if a failure happens + + + align:start position:0% +there's no problem if a failure happens +until you get to the last line until you + + align:start position:0% +until you get to the last line until you + + + align:start position:0% +until you get to the last line until you +get to the careful put of the Chooser + + align:start position:0% +get to the careful put of the Chooser + + + align:start position:0% +get to the careful put of the Chooser +sector until that line is executed + + align:start position:0% +sector until that line is executed + + + align:start position:0% +sector until that line is executed +nobody sees the new dat + + align:start position:0% +nobody sees the new dat + + + align:start position:0% +nobody sees the new dat +everybody doing a get is continuing to + + align:start position:0% +everybody doing a get is continuing to + + + align:start position:0% +everybody doing a get is continuing to +see the old data not the new data that + + align:start position:0% +see the old data not the new data that + + + align:start position:0% +see the old data not the new data that +just got written with careful put after + + align:start position:0% +just got written with careful put after + + + align:start position:0% +just got written with careful put after +this careful put executes and returns + + align:start position:0% +this careful put executes and returns + + + align:start position:0% +this careful put executes and returns +then everybody's going to see the new + + align:start position:0% +then everybody's going to see the new + + + align:start position:0% +then everybody's going to see the new +data because the Chooser sector has been + + align:start position:0% +data because the Chooser sector has been + + + align:start position:0% +data because the Chooser sector has been +correctly changed so the only tricky + + align:start position:0% +correctly changed so the only tricky + + + align:start position:0% +correctly changed so the only tricky +part to worry about we've reduced this + + align:start position:0% +part to worry about we've reduced this + + + align:start position:0% +part to worry about we've reduced this +problem of the more General slightly + + align:start position:0% +problem of the more General slightly + + + align:start position:0% +problem of the more General slightly +more General case of writing these + + align:start position:0% +more General case of writing these + + + align:start position:0% +more General case of writing these +sectors and switching between them to + + align:start position:0% +sectors and switching between them to + + + align:start position:0% +sectors and switching between them to +the specific problem of figuring out + + align:start position:0% +the specific problem of figuring out + + + align:start position:0% +the specific problem of figuring out +what happens if a failure occurs in the + + align:start position:0% +what happens if a failure occurs in the + + + align:start position:0% +what happens if a failure occurs in the +middle of the Chooser sector right if a + + align:start position:0% +middle of the Chooser sector right if a + + + align:start position:0% +middle of the Chooser sector right if a +failure happens here one one of the + + align:start position:0% +failure happens here one one of the + + + align:start position:0% +failure happens here one one of the +things the common thing that could + + align:start position:0% +things the common thing that could + + + align:start position:0% +things the common thing that could +happen is that the this sectors this + + align:start position:0% +happen is that the this sectors this + + + align:start position:0% +happen is that the this sectors this +particular sector's check sum doesn't + + align:start position:0% +particular sector's check sum doesn't + + + align:start position:0% +particular sector's check sum doesn't +match the data that's written here so + + align:start position:0% +match the data that's written here so + + + align:start position:0% +match the data that's written here so +when you do a get of that sector here + + align:start position:0% +when you do a get of that sector here + + + align:start position:0% +when you do a get of that sector here +when you do a get of this sector um in + + align:start position:0% +when you do a get of this sector um in + + + align:start position:0% +when you do a get of this sector um in +the first line up there uh when you do a + + align:start position:0% +the first line up there uh when you do a + + + align:start position:0% +the first line up there uh when you do a +careful get of that you'll find that um + + align:start position:0% +careful get of that you'll find that um + + + align:start position:0% +careful get of that you'll find that um +the check doesn't match so it returns a + + align:start position:0% +the check doesn't match so it returns a + + + align:start position:0% +the check doesn't match so it returns a +status of not okay so if the status is + + align:start position:0% +status of not okay so if the status is + + + align:start position:0% +status of not okay so if the status is +not okay you have to figure out which of + + align:start position:0% +not okay you have to figure out which of + + + align:start position:0% +not okay you have to figure out which of +the two copies to + + align:start position:0% +the two copies to + + + align:start position:0% +the two copies to +put now the reason you can pick either + + align:start position:0% +put now the reason you can pick either + + + align:start position:0% +put now the reason you can pick either +and you can arbitrarily pick here I've + + align:start position:0% +and you can arbitrarily pick here I've + + + align:start position:0% +and you can arbitrarily pick here I've +arbitrarily picked + + align:start position:0% +arbitrarily picked + + + align:start position:0% +arbitrarily picked +to uh read the data from sector zero but + + align:start position:0% +to uh read the data from sector zero but + + + align:start position:0% +to uh read the data from sector zero but +you could pick either of these okay and + + align:start position:0% +you could pick either of these okay and + + + align:start position:0% +you could pick either of these okay and +the reason it's okay to pick either is + + align:start position:0% +the reason it's okay to pick either is + + + align:start position:0% +the reason it's okay to pick either is +you know for sure that the failure must + + align:start position:0% +you know for sure that the failure must + + + align:start position:0% +you know for sure that the failure must +have happened here while writing this + + align:start position:0% +have happened here while writing this + + + align:start position:0% +have happened here while writing this +Chooser + + align:start position:0% +Chooser + + + align:start position:0% +Chooser +sector and because there are no + + align:start position:0% +sector and because there are no + + + align:start position:0% +sector and because there are no +concurrent threads going on you're + + align:start position:0% +concurrent threads going on you're + + + align:start position:0% +concurrent threads going on you're +assured that there is no failure that + + align:start position:0% +assured that there is no failure that + + + align:start position:0% +assured that there is no failure that +happens here while writing that happened + + align:start position:0% +happens here while writing that happened + + + align:start position:0% +happens here while writing that happened +here while writing d0 nor was there any + + align:start position:0% +here while writing d0 nor was there any + + + align:start position:0% +here while writing d0 nor was there any +failure that occurred here while writing + + align:start position:0% + + + + align:start position:0% + +D1 because the Assumption we made was + + align:start position:0% +D1 because the Assumption we made was + + + align:start position:0% +D1 because the Assumption we made was +that there is no concurrency + + align:start position:0% +that there is no concurrency + + + align:start position:0% +that there is no concurrency +so system crashes and recovers and + + align:start position:0% +so system crashes and recovers and + + + align:start position:0% +so system crashes and recovers and +discovers that there's a failure or the + + align:start position:0% +discovers that there's a failure or the + + + align:start position:0% +discovers that there's a failure or the +the get of the Chooser sector the + + align:start position:0% +the get of the Chooser sector the + + + align:start position:0% +the get of the Chooser sector the +careful get of the Chooser sector didn't + + align:start position:0% +careful get of the Chooser sector didn't + + + align:start position:0% +careful get of the Chooser sector didn't +quite work out uh didn't give you the a + + align:start position:0% +quite work out uh didn't give you the a + + + align:start position:0% +quite work out uh didn't give you the a +status of okay that it was not okay then + + align:start position:0% +status of okay that it was not okay then + + + align:start position:0% +status of okay that it was not okay then +you know that the failure happened while + + align:start position:0% +you know that the failure happened while + + + align:start position:0% +you know that the failure happened while +writing here and what that means is it's + + align:start position:0% +writing here and what that means is it's + + + align:start position:0% +writing here and what that means is it's +perfectly okay for you to read from + + align:start position:0% +perfectly okay for you to read from + + + align:start position:0% +perfectly okay for you to read from +either version both of those correspond + + align:start position:0% +either version both of those correspond + + + align:start position:0% +either version both of those correspond +to a right to that individual sector + + align:start position:0% +to a right to that individual sector + + + align:start position:0% +to a right to that individual sector +that did not fail in the + + align:start position:0% +that did not fail in the + + + align:start position:0% +that did not fail in the +middle and it doesn't matter which of + + align:start position:0% +middle and it doesn't matter which of + + + align:start position:0% +middle and it doesn't matter which of +the two you + + align:start position:0% +the two you + + + align:start position:0% +the two you +pick and that's the reason why um this + + align:start position:0% +pick and that's the reason why um this + + + align:start position:0% +pick and that's the reason why um this +approach basically + + align:start position:0% + + + + align:start position:0% + +works and if you look at the solution + + align:start position:0% +works and if you look at the solution + + + align:start position:0% +works and if you look at the solution +this copy idea is actually a pretty + + align:start position:0% +this copy idea is actually a pretty + + + align:start position:0% +this copy idea is actually a pretty +critical idea for all of our solutions + + align:start position:0% +critical idea for all of our solutions + + + align:start position:0% +critical idea for all of our solutions +to achieving uh recoverability and it's + + align:start position:0% +to achieving uh recoverability and it's + + + align:start position:0% +to achieving uh recoverability and it's +going to lead to a rule that we're going + + align:start position:0% +going to lead to a rule that we're going + + + align:start position:0% +going to lead to a rule that we're going +to call um the golden rule of + + align:start position:0% +to call um the golden rule of + + + align:start position:0% +to call um the golden rule of +recoverability the rule says never + + align:start position:0% +recoverability the rule says never + + + align:start position:0% +recoverability the rule says never +modify the only + + align:start position:0% + + + + align:start position:0% + +copy so if you are asked to invent to + + align:start position:0% +copy so if you are asked to invent to + + + align:start position:0% +copy so if you are asked to invent to +come up with a recover way to achieve + + align:start position:0% +come up with a recover way to achieve + + + align:start position:0% +come up with a recover way to achieve +something that's recoverable + + align:start position:0% +something that's recoverable + + + align:start position:0% +something that's recoverable +um you know one guideline this is + + align:start position:0% +um you know one guideline this is + + + align:start position:0% +um you know one guideline this is +unfortunately not a sufficient condition + + align:start position:0% +unfortunately not a sufficient condition + + + align:start position:0% +unfortunately not a sufficient condition +but a necessary condition is that if you + + align:start position:0% +but a necessary condition is that if you + + + align:start position:0% +but a necessary condition is that if you +have something and you only have one + + align:start position:0% +have something and you only have one + + + align:start position:0% +have something and you only have one +copy of that that you end up writing + + align:start position:0% +copy of that that you end up writing + + + align:start position:0% +copy of that that you end up writing +then chances are that if a failure + + align:start position:0% +then chances are that if a failure + + + align:start position:0% +then chances are that if a failure +happens in the middle of writing that + + align:start position:0% +happens in the middle of writing that + + + align:start position:0% +happens in the middle of writing that +journal that one copy you can't back out + + align:start position:0% +journal that one copy you can't back out + + + align:start position:0% +journal that one copy you can't back out +of it so your scheme wouldn't + + align:start position:0% + + + + align:start position:0% + +work so never modify the only copy of + + align:start position:0% +work so never modify the only copy of + + + align:start position:0% +work so never modify the only copy of +anything that's the general rule + + align:start position:0% + + + + align:start position:0% + +now there's another point to uh observe + + align:start position:0% +now there's another point to uh observe + + + align:start position:0% +now there's another point to uh observe +about this recoverable um dis Rite and + + align:start position:0% +about this recoverable um dis Rite and + + + align:start position:0% +about this recoverable um dis Rite and +that has to do with that careful put + + align:start position:0% +that has to do with that careful put + + + align:start position:0% +that has to do with that careful put +line right before that line everybody + + align:start position:0% +line right before that line everybody + + + align:start position:0% +line right before that line everybody +else reading this recoverable sector + + align:start position:0% +else reading this recoverable sector + + + align:start position:0% +else reading this recoverable sector +using recoverable get sees the old + + align:start position:0% +using recoverable get sees the old + + + align:start position:0% +using recoverable get sees the old +version of data right after that line + + align:start position:0% +version of data right after that line + + + align:start position:0% +version of data right after that line +has finished everybody reading it sees + + align:start position:0% +has finished everybody reading it sees + + + align:start position:0% +has finished everybody reading it sees +the new + + align:start position:0% +the new + + + align:start position:0% +the new +data that line is an example of + + align:start position:0% +data that line is an example of + + + align:start position:0% +data that line is an example of +something that we'll uh repeatedly visit + + align:start position:0% +something that we'll uh repeatedly visit + + + align:start position:0% +something that we'll uh repeatedly visit +uh and use called a commit point + + align:start position:0% +uh and use called a commit point + + + align:start position:0% +uh and use called a commit point +point the successful completion of that + + align:start position:0% +point the successful completion of that + + + align:start position:0% +point the successful completion of that +line ensures that everybody else + + align:start position:0% +line ensures that everybody else + + + align:start position:0% +line ensures that everybody else +following doing gets will see the data + + align:start position:0% +following doing gets will see the data + + + align:start position:0% +following doing gets will see the data +that was written by this + + align:start position:0% +that was written by this + + + align:start position:0% +that was written by this +put and before that line is run + + align:start position:0% +put and before that line is run + + + align:start position:0% +put and before that line is run +everybody else following will see the + + align:start position:0% +everybody else following will see the + + + align:start position:0% +everybody else following will see the +the older version of the + + align:start position:0% +the older version of the + + + align:start position:0% +the older version of the +data now if a failure occurs in the + + align:start position:0% +data now if a failure occurs in the + + + align:start position:0% +data now if a failure occurs in the +middle of that line then the answer + + align:start position:0% +middle of that line then the answer + + + align:start position:0% +middle of that line then the answer +depends on what the recovery procedure + + align:start position:0% +depends on what the recovery procedure + + + align:start position:0% +depends on what the recovery procedure +does and one approach might be that the + + align:start position:0% +does and one approach might be that the + + + align:start position:0% +does and one approach might be that the +invoker of this module the person who + + align:start position:0% +invoker of this module the person who + + + align:start position:0% +invoker of this module the person who +originally did the dis right if if a + + align:start position:0% +originally did the dis right if if a + + + align:start position:0% +originally did the dis right if if a +failure happens in the middle of the + + align:start position:0% +failure happens in the middle of the + + + align:start position:0% +failure happens in the middle of the +right one plan might be that the invoker + + align:start position:0% +right one plan might be that the invoker + + + align:start position:0% +right one plan might be that the invoker +of that dis right upon recovery tries + + align:start position:0% +of that dis right upon recovery tries + + + align:start position:0% +of that dis right upon recovery tries +the right again tries the tries the put + + align:start position:0% +the right again tries the tries the put + + + align:start position:0% +the right again tries the tries the put +again and the way he tries the put is he + + align:start position:0% +again and the way he tries the put is he + + + align:start position:0% +again and the way he tries the put is he +first does a get and sees what answer is + + align:start position:0% +first does a get and sees what answer is + + + align:start position:0% +first does a get and sees what answer is +returned if the answer is the new answer + + align:start position:0% +returned if the answer is the new answer + + + align:start position:0% +returned if the answer is the new answer +then he says okay everything is fine if + + align:start position:0% +then he says okay everything is fine if + + + align:start position:0% +then he says okay everything is fine if +the answer is the old answer then he + + align:start position:0% +the answer is the old answer then he + + + align:start position:0% +the answer is the old answer then he +says I'm going to retry the put and this + + align:start position:0% +says I'm going to retry the put and this + + + align:start position:0% +says I'm going to retry the put and this +is an example of something we saw the + + align:start position:0% +is an example of something we saw the + + + align:start position:0% +is an example of something we saw the +last time which is temporal redundancy + + align:start position:0% +last time which is temporal redundancy + + + align:start position:0% +last time which is temporal redundancy +you can retry things you not only can + + align:start position:0% +you can retry things you not only can + + + align:start position:0% +you can retry things you not only can +replicate in space but you can rety + + align:start position:0% +replicate in space but you can rety + + + align:start position:0% +replicate in space but you can rety +things in time which is the idea here + + align:start position:0% +things in time which is the idea here + + + align:start position:0% +things in time which is the idea here +for achieving uh fa + + align:start position:0% + + + + align:start position:0% + +tolerance + + align:start position:0% + + + + align:start position:0% + +so so an example of this idea called a + + align:start position:0% +so so an example of this idea called a + + + align:start position:0% +so so an example of this idea called a +commit point is that line that careful + + align:start position:0% +commit point is that line that careful + + + align:start position:0% +commit point is that line that careful +put line and in general a commit point + + align:start position:0% +put line and in general a commit point + + + align:start position:0% +put line and in general a commit point +is a point in a recoverable action in + + align:start position:0% +is a point in a recoverable action in + + + align:start position:0% +is a point in a recoverable action in +this case and it'll turn out to be an + + align:start position:0% +this case and it'll turn out to be an + + + align:start position:0% +this case and it'll turn out to be an +idea that's useful for um isolated + + align:start position:0% +idea that's useful for um isolated + + + align:start position:0% +idea that's useful for um isolated +actions and for transactions more + + align:start position:0% +actions and for transactions more + + + align:start position:0% +actions and for transactions more +generally but a commit point is there's + + align:start position:0% +generally but a commit point is there's + + + align:start position:0% +generally but a commit point is there's +a point where before the commit Point + + align:start position:0% +a point where before the commit Point + + + align:start position:0% +a point where before the commit Point +other people don't see the results of + + align:start position:0% +other people don't see the results of + + + align:start position:0% +other people don't see the results of +your action and after the commit Point + + align:start position:0% +your action and after the commit Point + + + align:start position:0% +your action and after the commit Point +successfully finishes everybody sees the + + align:start position:0% +successfully finishes everybody sees the + + + align:start position:0% +successfully finishes everybody sees the +results of your action and that's the + + align:start position:0% +results of your action and that's the + + + align:start position:0% +results of your action and that's the +definition of a commit point + + align:start position:0% + + + + align:start position:0% + +so now we have to generalize this idea + + align:start position:0% +so now we have to generalize this idea + + + align:start position:0% +so now we have to generalize this idea +because what we've seen is a scheme by + + align:start position:0% +because what we've seen is a scheme by + + + align:start position:0% +because what we've seen is a scheme by +the way is this clear to everybody a + + align:start position:0% +the way is this clear to everybody a + + + align:start position:0% +the way is this clear to everybody a +scheme are any questions about + + align:start position:0% +scheme are any questions about + + + align:start position:0% +scheme are any questions about +recoverable put and + + align:start position:0% +recoverable put and + + + align:start position:0% +recoverable put and +get what does that + + align:start position:0% +get what does that + + + align:start position:0% +get what does that +mean no questions are not + + align:start position:0% +mean no questions are not + + + align:start position:0% +mean no questions are not +clear questions + + align:start position:0% +clear questions + + + align:start position:0% +clear questions +okay all right good so now we have to + + align:start position:0% +okay all right good so now we have to + + + align:start position:0% +okay all right good so now we have to +generalize this + + align:start position:0% + + + + align:start position:0% + +idea because you know we the the class + + align:start position:0% +idea because you know we the the class + + + align:start position:0% +idea because you know we the the class +of program s where you could just sort + + align:start position:0% +of program s where you could just sort + + + align:start position:0% +of program s where you could just sort +of read and write from one sector is + + align:start position:0% +of read and write from one sector is + + + align:start position:0% +of read and write from one sector is +quite + + align:start position:0% + + + + align:start position:0% + +limited and so to generalize this + + align:start position:0% +limited and so to generalize this + + + align:start position:0% +limited and so to generalize this +generalize this idea what we're going to + + align:start position:0% +generalize this idea what we're going to + + + align:start position:0% +generalize this idea what we're going to +do + + align:start position:0% +do + + + align:start position:0% +do +is to change the programming model for + + align:start position:0% +is to change the programming model for + + + align:start position:0% +is to change the programming model for +writing recoverable actions a little bit + + align:start position:0% +writing recoverable actions a little bit + + + align:start position:0% +writing recoverable actions a little bit +so ideally what you would like to be + + align:start position:0% +so ideally what you would like to be + + + align:start position:0% +so ideally what you would like to be +able to do the model we're going to try + + align:start position:0% +able to do the model we're going to try + + + align:start position:0% +able to do the model we're going to try +to get at is to be able to take a + + align:start position:0% +to get at is to be able to take a + + + align:start position:0% +to get at is to be able to take a +procedure and say begin recoverable + + align:start position:0% +procedure and say begin recoverable + + + align:start position:0% +procedure and say begin recoverable +action in front of that procedure write + + align:start position:0% +action in front of that procedure write + + + align:start position:0% +action in front of that procedure write +the code for that procedure and just say + + align:start position:0% +the code for that procedure and just say + + + align:start position:0% +the code for that procedure and just say +end recoverable action and and sort of + + align:start position:0% +end recoverable action and and sort of + + + align:start position:0% +end recoverable action and and sort of +magically end up with a model where um + + align:start position:0% +magically end up with a model where um + + + align:start position:0% +magically end up with a model where um +that action the set of steps in that + + align:start position:0% +that action the set of steps in that + + + align:start position:0% +that action the set of steps in that +action becomes recoverable and it'll + + align:start position:0% +action becomes recoverable and it'll + + + align:start position:0% +action becomes recoverable and it'll +turn out we come very very close to + + align:start position:0% +turn out we come very very close to + + + align:start position:0% +turn out we come very very close to +achieving this very general model um by + + align:start position:0% +achieving this very general model um by + + + align:start position:0% +achieving this very general model um by +making some slight assumptions in the + + align:start position:0% +making some slight assumptions in the + + + align:start position:0% +making some slight assumptions in the +way people or requiring the programmer + + align:start position:0% +way people or requiring the programmer + + + align:start position:0% +way people or requiring the programmer +to make some small assumptions in the + + align:start position:0% +to make some small assumptions in the + + + align:start position:0% +to make some small assumptions in the +way they write uh their + + align:start position:0% + + + + align:start position:0% + +programs and this generalization to more + + align:start position:0% +programs and this generalization to more + + + align:start position:0% +programs and this generalization to more +General actions um that are recoverable + + align:start position:0% +General actions um that are recoverable + + + align:start position:0% +General actions um that are recoverable +and you know generalizing from a single + + align:start position:0% +and you know generalizing from a single + + + align:start position:0% +and you know generalizing from a single +sector uses the idea of a commit + + align:start position:0% +sector uses the idea of a commit + + + align:start position:0% +sector uses the idea of a commit +point so the way this is going to work + + align:start position:0% +point so the way this is going to work + + + align:start position:0% +point so the way this is going to work +out is the programmer is going to end up + + align:start position:0% +out is the programmer is going to end up + + + align:start position:0% +out is the programmer is going to end up +writing for any recoverable action's + + align:start position:0% +writing for any recoverable action's + + + align:start position:0% +writing for any recoverable action's +she's going she or he is going to end up + + align:start position:0% +she's going she or he is going to end up + + + align:start position:0% +she's going she or he is going to end up +writing this special function call um + + align:start position:0% +writing this special function call um + + + align:start position:0% +writing this special function call um +called begin recoverable action and then + + align:start position:0% +called begin recoverable action and then + + + align:start position:0% +called begin recoverable action and then +writing the code for that recoverable + + align:start position:0% +writing the code for that recoverable + + + align:start position:0% +writing the code for that recoverable +action and then at some point in the + + align:start position:0% +action and then at some point in the + + + align:start position:0% +action and then at some point in the +middle of this code + + align:start position:0% +middle of this code + + + align:start position:0% +middle of this code +calling a function called + + align:start position:0% +calling a function called + + + align:start position:0% +calling a function called +commit and the idea is that until this + + align:start position:0% +commit and the idea is that until this + + + align:start position:0% +commit and the idea is that until this +commit is called nobody else sees the + + align:start position:0% +commit is called nobody else sees the + + + align:start position:0% +commit is called nobody else sees the +results of this action which means that + + align:start position:0% +results of this action which means that + + + align:start position:0% +results of this action which means that +if a failure happened the result would + + align:start position:0% +if a failure happened the result would + + + align:start position:0% +if a failure happened the result would +be as if the upon crash recovery or um + + align:start position:0% +be as if the upon crash recovery or um + + + align:start position:0% +be as if the upon crash recovery or um +you know once the system restarts the + + align:start position:0% +you know once the system restarts the + + + align:start position:0% +you know once the system restarts the +result would be as if none of the steps + + align:start position:0% +result would be as if none of the steps + + + align:start position:0% +result would be as if none of the steps +of this action ever happened so they + + align:start position:0% +of this action ever happened so they + + + align:start position:0% +of this action ever happened so they +call commit and then once commit + + align:start position:0% +call commit and then once commit + + + align:start position:0% +call commit and then once commit +finishes then no matter what happens a + + align:start position:0% +finishes then no matter what happens a + + + align:start position:0% +finishes then no matter what happens a +failure could happen and re the system + + align:start position:0% +failure could happen and re the system + + + align:start position:0% +failure could happen and re the system +restarts but once commit is called and + + align:start position:0% +restarts but once commit is called and + + + align:start position:0% +restarts but once commit is called and +it returns then you're guaranteed that + + align:start position:0% +it returns then you're guaranteed that + + + align:start position:0% +it returns then you're guaranteed that +all other actions see the state changes + + align:start position:0% +all other actions see the state changes + + + align:start position:0% +all other actions see the state changes +made by this action and that's the you + + align:start position:0% +made by this action and that's the you + + + align:start position:0% +made by this action and that's the you +know so this is a special call and then + + align:start position:0% +know so this is a special call and then + + + align:start position:0% +know so this is a special call and then +you know after commit they might have + + align:start position:0% +you know after commit they might have + + + align:start position:0% +you know after commit they might have +some other lines that they write and + + align:start position:0% +some other lines that they write and + + + align:start position:0% +some other lines that they write and +then they end the recoverable + + align:start position:0% +then they end the recoverable + + + align:start position:0% +then they end the recoverable +action now in many many cases the very + + align:start position:0% +action now in many many cases the very + + + align:start position:0% +action now in many many cases the very +last thing that's done before before the + + align:start position:0% +last thing that's done before before the + + + align:start position:0% +last thing that's done before before the +end recoverable action is a + + align:start position:0% +end recoverable action is a + + + align:start position:0% +end recoverable action is a +commit um but in general you might have + + align:start position:0% +commit um but in general you might have + + + align:start position:0% +commit um but in general you might have +other things here uh and it turn out + + align:start position:0% +other things here uh and it turn out + + + align:start position:0% +other things here uh and it turn out +that there you can't do arbitary things + + align:start position:0% +that there you can't do arbitary things + + + align:start position:0% +that there you can't do arbitary things +here for example you can't do uh dis + + align:start position:0% +here for example you can't do uh dis + + + align:start position:0% +here for example you can't do uh dis +writes that you want to make recoverable + + align:start position:0% +writes that you want to make recoverable + + + align:start position:0% +writes that you want to make recoverable +over here because the moment you do that + + align:start position:0% +over here because the moment you do that + + + align:start position:0% +over here because the moment you do that +by definition if a crash happens after a + + align:start position:0% +by definition if a crash happens after a + + + align:start position:0% +by definition if a crash happens after a +commit we don't have a plan to back out + + align:start position:0% +commit we don't have a plan to back out + + + align:start position:0% +commit we don't have a plan to back out +of it because the semantics were that + + align:start position:0% +of it because the semantics were that + + + align:start position:0% +of it because the semantics were that +once a commit is done then no matter + + align:start position:0% +once a commit is done then no matter + + + align:start position:0% +once a commit is done then no matter +what happens the state of the system is + + align:start position:0% +what happens the state of the system is + + + align:start position:0% +what happens the state of the system is +as if all of the um things in this + + align:start position:0% +as if all of the um things in this + + + align:start position:0% +as if all of the um things in this +action finished so the discipline is + + align:start position:0% +action finished so the discipline is + + + align:start position:0% +action finished so the discipline is +going to be this thing is called the + + align:start position:0% +going to be this thing is called the + + + align:start position:0% +going to be this thing is called the +post commit the pre-commit + + align:start position:0% +post commit the pre-commit + + + align:start position:0% +post commit the pre-commit +phase and this thing here is called the + + align:start position:0% +phase and this thing here is called the + + + align:start position:0% +phase and this thing here is called the +postc commit + + align:start position:0% + + + + align:start position:0% + +phase and so the the idea is that in the + + align:start position:0% +phase and so the the idea is that in the + + + align:start position:0% +phase and so the the idea is that in the +pre-commit phase um you should always be + + align:start position:0% +pre-commit phase um you should always be + + + align:start position:0% +pre-commit phase um you should always be +prep prepared to back out because by + + align:start position:0% +prep prepared to back out because by + + + align:start position:0% +prep prepared to back out because by +definition if a failure occurs before + + align:start position:0% +definition if a failure occurs before + + + align:start position:0% +definition if a failure occurs before +commit is called um the results going to + + align:start position:0% +commit is called um the results going to + + + align:start position:0% +commit is called um the results going to +be as if nothing ever happened which + + align:start position:0% +be as if nothing ever happened which + + + align:start position:0% +be as if nothing ever happened which +means that any change you make here you + + align:start position:0% +means that any change you make here you + + + align:start position:0% +means that any change you make here you +better religiously Follow That Never + + align:start position:0% +better religiously Follow That Never + + + align:start position:0% +better religiously Follow That Never +modify the only copy Rule and be + + align:start position:0% +modify the only copy Rule and be + + + align:start position:0% +modify the only copy Rule and be +prepared to back out in the post commit + + align:start position:0% +prepared to back out in the post commit + + + align:start position:0% +prepared to back out in the post commit +phase conversely you better make sure + + align:start position:0% +phase conversely you better make sure + + + align:start position:0% +phase conversely you better make sure +that you can never back you you don't + + align:start position:0% +that you can never back you you don't + + + align:start position:0% +that you can never back you you don't +you know you don't have the option to + + align:start position:0% +you know you don't have the option to + + + align:start position:0% +you know you don't have the option to +back out so you better make sure that + + align:start position:0% +back out so you better make sure that + + + align:start position:0% +back out so you better make sure that +once you get here you just run to + + align:start position:0% +once you get here you just run to + + + align:start position:0% +once you get here you just run to +completion so if a failure occurs + + align:start position:0% +completion so if a failure occurs + + + align:start position:0% +completion so if a failure occurs +and in out here and you restart you + + align:start position:0% +and in out here and you restart you + + + align:start position:0% +and in out here and you restart you +better make sure that you can run to + + align:start position:0% +better make sure that you can run to + + + align:start position:0% +better make sure that you can run to +completion it in fact there are a few + + align:start position:0% +completion it in fact there are a few + + + align:start position:0% +completion it in fact there are a few +other restrictions out in the post + + align:start position:0% +other restrictions out in the post + + + align:start position:0% +other restrictions out in the post +commit phase um so let me do this by an + + align:start position:0% +commit phase um so let me do this by an + + + align:start position:0% +commit phase um so let me do this by an +example so in the pre-commit phase + + align:start position:0% +example so in the pre-commit phase + + + align:start position:0% +example so in the pre-commit phase +because you have to be prepared to back + + align:start position:0% +because you have to be prepared to back + + + align:start position:0% +because you have to be prepared to back +out it often means in practice that you + + align:start position:0% +out it often means in practice that you + + + align:start position:0% +out it often means in practice that you +can't be sending messages out onto the + + align:start position:0% +can't be sending messages out onto the + + + align:start position:0% +can't be sending messages out onto the +network you can you know maintain your + + align:start position:0% +network you can you know maintain your + + + align:start position:0% +network you can you know maintain your +local state but you know you have a way + + align:start position:0% +local state but you know you have a way + + + align:start position:0% +local state but you know you have a way +to back out of that uh but if you're + + align:start position:0% +to back out of that uh but if you're + + + align:start position:0% +to back out of that uh but if you're +sending messages out onto the network + + align:start position:0% +sending messages out onto the network + + + align:start position:0% +sending messages out onto the network +and you don't have a you know a bigger + + align:start position:0% +and you don't have a you know a bigger + + + align:start position:0% +and you don't have a you know a bigger +story to deal with it you know we'll + + align:start position:0% +story to deal with it you know we'll + + + align:start position:0% +story to deal with it you know we'll +talk later about um nesting Atomic + + align:start position:0% +talk later about um nesting Atomic + + + align:start position:0% +talk later about um nesting Atomic +actions within one another or nesting + + align:start position:0% +actions within one another or nesting + + + align:start position:0% +actions within one another or nesting +recoverable actions within one another + + align:start position:0% +recoverable actions within one another + + + align:start position:0% +recoverable actions within one another +in a few lectures from now but in the + + align:start position:0% +in a few lectures from now but in the + + + align:start position:0% +in a few lectures from now but in the +simple model if you do anything that you + + align:start position:0% +simple model if you do anything that you + + + align:start position:0% +simple model if you do anything that you +can't back out off such as sending a + + align:start position:0% +can't back out off such as sending a + + + align:start position:0% +can't back out off such as sending a +network packet then you're stuck so all + + align:start position:0% +network packet then you're stuck so all + + + align:start position:0% +network packet then you're stuck so all +of that stuff like you know printing out + + align:start position:0% +of that stuff like you know printing out + + + align:start position:0% +of that stuff like you know printing out +checks or you know sending a firing a + + align:start position:0% +checks or you know sending a firing a + + + align:start position:0% +checks or you know sending a firing a +bullet or something things like that + + align:start position:0% +bullet or something things like that + + + align:start position:0% +bullet or something things like that +that you can't back out of you better + + align:start position:0% +that you can't back out of you better + + + align:start position:0% +that you can't back out of you better +put out here all the things that you can + + align:start position:0% +put out here all the things that you can + + + align:start position:0% +put out here all the things that you can +back out off go here likewise nothing + + align:start position:0% +back out off go here likewise nothing + + + align:start position:0% +back out off go here likewise nothing +you can back out of has to go can go + + align:start position:0% +you can back out of has to go can go + + + align:start position:0% +you can back out of has to go can go +here because once you reach here and a + + align:start position:0% +here because once you reach here and a + + + align:start position:0% +here because once you reach here and a +failure happen you have to continue to + + align:start position:0% +failure happen you have to continue to + + + align:start position:0% +failure happen you have to continue to +completion what that means is in the + + align:start position:0% +completion what that means is in the + + + align:start position:0% +completion what that means is in the +post commit phase really you can't do + + align:start position:0% +post commit phase really you can't do + + + align:start position:0% +post commit phase really you can't do +very many things I mean you can do + + align:start position:0% +very many things I mean you can do + + + align:start position:0% +very many things I mean you can do +things that don't really have um um you + + align:start position:0% +things that don't really have um um you + + + align:start position:0% +things that don't really have um um you +know for example you can do things that + + align:start position:0% +know for example you can do things that + + + align:start position:0% +know for example you can do things that +are okay to keep doing for example you + + align:start position:0% +are okay to keep doing for example you + + + align:start position:0% +are okay to keep doing for example you +can do item potent operations so that if + + align:start position:0% +can do item potent operations so that if + + + align:start position:0% +can do item potent operations so that if +a failure happens here and you recover + + align:start position:0% +a failure happens here and you recover + + + align:start position:0% +a failure happens here and you recover +then you know that you're out at this + + align:start position:0% +then you know that you're out at this + + + align:start position:0% +then you know that you're out at this +point so you could keep retrying those + + align:start position:0% +point so you could keep retrying those + + + align:start position:0% +point so you could keep retrying those +actions over and over again until you + + align:start position:0% +actions over and over again until you + + + align:start position:0% +actions over and over again until you +ensure that it + + align:start position:0% +ensure that it + + + align:start position:0% +ensure that it +completes but that's the only those are + + align:start position:0% +completes but that's the only those are + + + align:start position:0% +completes but that's the only those are +the only rules there's a pre-commit + + align:start position:0% +the only rules there's a pre-commit + + + align:start position:0% +the only rules there's a pre-commit +phase and a postc commit phase there's a + + align:start position:0% +phase and a postc commit phase there's a + + + align:start position:0% +phase and a postc commit phase there's a +commit that's explicitly called + + align:start position:0% +commit that's explicitly called + + + align:start position:0% +commit that's explicitly called +now in addition there's another call + + align:start position:0% +now in addition there's another call + + + align:start position:0% +now in addition there's another call +that that a programmer can make or that + + align:start position:0% +that that a programmer can make or that + + + align:start position:0% +that that a programmer can make or that +the system can invoke automatically and + + align:start position:0% +the system can invoke automatically and + + + align:start position:0% +the system can invoke automatically and +that's called + + align:start position:0% + + + + align:start position:0% + +aart for example when you're moving + + align:start position:0% +aart for example when you're moving + + + align:start position:0% +aart for example when you're moving +money from savings account to checking + + align:start position:0% +money from savings account to checking + + + align:start position:0% +money from savings account to checking +account in that transfer example um if + + align:start position:0% +account in that transfer example um if + + + align:start position:0% +account in that transfer example um if +you discover in the middle here that you + + align:start position:0% +you discover in the middle here that you + + + align:start position:0% +you discover in the middle here that you +don't have enough funds to cover that + + align:start position:0% +don't have enough funds to cover that + + + align:start position:0% +don't have enough funds to cover that +transfer you could just decide to abart + + align:start position:0% +transfer you could just decide to abart + + + align:start position:0% +transfer you could just decide to abart +the + + align:start position:0% +the + + + align:start position:0% +the +transaction excuse me about the + + align:start position:0% +transaction excuse me about the + + + align:start position:0% +transaction excuse me about the +recoverable + + align:start position:0% +recoverable + + + align:start position:0% +recoverable +action and what that means is that abort + + align:start position:0% +action and what that means is that abort + + + align:start position:0% +action and what that means is that abort +automatically will ensure that the state + + align:start position:0% +automatically will ensure that the state + + + align:start position:0% +automatically will ensure that the state +of the system is at the point right + + align:start position:0% +of the system is at the point right + + + align:start position:0% +of the system is at the point right +before the start of the recoverable + + align:start position:0% +before the start of the recoverable + + + align:start position:0% +before the start of the recoverable +action so whatever changes were made in + + align:start position:0% +action so whatever changes were made in + + + align:start position:0% +action so whatever changes were made in +the middle until abort was called um end + + align:start position:0% +the middle until abort was called um end + + + align:start position:0% +the middle until abort was called um end +up backing out now abort might also be + + align:start position:0% +up backing out now abort might also be + + + align:start position:0% +up backing out now abort might also be +invoked by the system if you know in a + + align:start position:0% +invoked by the system if you know in a + + + align:start position:0% +invoked by the system if you know in a +database system there's somebody you're + + align:start position:0% +database system there's somebody you're + + + align:start position:0% +database system there's somebody you're +booking airline tickets and car + + align:start position:0% +booking airline tickets and car + + + align:start position:0% +booking airline tickets and car +reservations and all of that and you + + align:start position:0% +reservations and all of that and you + + + align:start position:0% +reservations and all of that and you +discover in the middle that you're not + + align:start position:0% +discover in the middle that you're not + + + align:start position:0% +discover in the middle that you're not +actually able to find you know um hotel + + align:start position:0% +actually able to find you know um hotel + + + align:start position:0% +actually able to find you know um hotel +for the same dates so you might just + + align:start position:0% +for the same dates so you might just + + + align:start position:0% +for the same dates so you might just +abort the whole process you know so + + align:start position:0% +abort the whole process you know so + + + align:start position:0% +abort the whole process you know so +control C the thre you're running uh + + align:start position:0% +control C the thre you're running uh + + + align:start position:0% +control C the thre you're running uh +which means that all of the work that's + + align:start position:0% +which means that all of the work that's + + + align:start position:0% +which means that all of the work that's +been done has to be backed out and so + + align:start position:0% +been done has to be backed out and so + + + align:start position:0% +been done has to be backed out and so +the system would normally Implement that + + align:start position:0% +the system would normally Implement that + + + align:start position:0% +the system would normally Implement that +by aborting all of the changes that + + align:start position:0% +by aborting all of the changes that + + + align:start position:0% +by aborting all of the changes that +you've made um so far you know it'll + + align:start position:0% +you've made um so far you know it'll + + + align:start position:0% +you've made um so far you know it'll +back out of your hotel reservation it'll + + align:start position:0% +back out of your hotel reservation it'll + + + align:start position:0% +back out of your hotel reservation it'll +I'm sorry your car reservation back out + + align:start position:0% +I'm sorry your car reservation back out + + + align:start position:0% +I'm sorry your car reservation back out +of your Airline reservation and so on so + + align:start position:0% +of your Airline reservation and so on so + + + align:start position:0% +of your Airline reservation and so on so +bot is called in a few different + + align:start position:0% +bot is called in a few different + + + align:start position:0% +bot is called in a few different +contexts sometimes by the program itself + + align:start position:0% +contexts sometimes by the program itself + + + align:start position:0% +contexts sometimes by the program itself +sometimes by the system to free up + + align:start position:0% +sometimes by the system to free up + + + align:start position:0% +sometimes by the system to free up +resources sometimes by the user of your + + align:start position:0% +resources sometimes by the user of your + + + align:start position:0% +resources sometimes by the user of your +uh for say a transaction system + + align:start position:0% + + + + align:start position:0% + +so before I U I'm not going to get into + + align:start position:0% +so before I U I'm not going to get into + + + align:start position:0% +so before I U I'm not going to get into +how we Implement um you know how we + + align:start position:0% +how we Implement um you know how we + + + align:start position:0% +how we Implement um you know how we +Implement recoverable action today but + + align:start position:0% +Implement recoverable action today but + + + align:start position:0% +Implement recoverable action today but +but this programming model is important + + align:start position:0% +but this programming model is important + + + align:start position:0% +but this programming model is important +to understand I do want to mention one + + align:start position:0% +to understand I do want to mention one + + + align:start position:0% +to understand I do want to mention one +thing going back to this idea of + + align:start position:0% +thing going back to this idea of + + + align:start position:0% +thing going back to this idea of +isolation that we talked about so if you + + align:start position:0% +isolation that we talked about so if you + + + align:start position:0% +isolation that we talked about so if you +recall isolation is this idea that you + + align:start position:0% +recall isolation is this idea that you + + + align:start position:0% +recall isolation is this idea that you +have two actions or multiple actions + + align:start position:0% +have two actions or multiple actions + + + align:start position:0% +have two actions or multiple actions +whose net effect is as if they ran in + + align:start position:0% +whose net effect is as if they ran in + + + align:start position:0% +whose net effect is as if they ran in +some sequential order some serial order + + align:start position:0% +some sequential order some serial order + + + align:start position:0% +some sequential order some serial order +A1 before A2 or A2 before A1 for all you + + align:start position:0% +A1 before A2 or A2 before A1 for all you + + + align:start position:0% +A1 before A2 or A2 before A1 for all you +know permutations of A1 A2 A3 Etc now + + align:start position:0% +know permutations of A1 A2 A3 Etc now + + + align:start position:0% +know permutations of A1 A2 A3 Etc now +this idea is actually very closely + + align:start position:0% +this idea is actually very closely + + + align:start position:0% +this idea is actually very closely +related but not the same as stuff we've + + align:start position:0% +related but not the same as stuff we've + + + align:start position:0% +related but not the same as stuff we've +seen before you know earlier in the + + align:start position:0% +seen before you know earlier in the + + + align:start position:0% +seen before you know earlier in the +semester we looked at ways in which um + + align:start position:0% +semester we looked at ways in which um + + + align:start position:0% +semester we looked at ways in which um +you you have multiple threads that need + + align:start position:0% +you you have multiple threads that need + + + align:start position:0% +you you have multiple threads that need +to be synchronized with each other and + + align:start position:0% +to be synchronized with each other and + + + align:start position:0% +to be synchronized with each other and +you know we actually did look at + + align:start position:0% +you know we actually did look at + + + align:start position:0% +you know we actually did look at +isolation as a concept then but we spe + + align:start position:0% +isolation as a concept then but we spe + + + align:start position:0% +isolation as a concept then but we spe +specifically focused on things like + + align:start position:0% +specifically focused on things like + + + align:start position:0% +specifically focused on things like +sequence coordination where you want to + + align:start position:0% +sequence coordination where you want to + + + align:start position:0% +sequence coordination where you want to +have one thread run before the other + + align:start position:0% +have one thread run before the other + + + align:start position:0% +have one thread run before the other +thread or one thread um you know run + + align:start position:0% +thread or one thread um you know run + + + align:start position:0% +thread or one thread um you know run +after the other thread for example in a + + align:start position:0% +after the other thread for example in a + + + align:start position:0% +after the other thread for example in a +producer consumer uh + + align:start position:0% +producer consumer uh + + + align:start position:0% +producer consumer uh +relationship the point is that in one + + align:start position:0% +relationship the point is that in one + + + align:start position:0% +relationship the point is that in one +significant respect achieving this idea + + align:start position:0% +significant respect achieving this idea + + + align:start position:0% +significant respect achieving this idea +of isolation for actions is harder than + + align:start position:0% +of isolation for actions is harder than + + + align:start position:0% +of isolation for actions is harder than +achieving sequence + + align:start position:0% +achieving sequence + + + align:start position:0% +achieving sequence +coordination and the reason it's harder + + align:start position:0% +coordination and the reason it's harder + + + align:start position:0% +coordination and the reason it's harder +is that everybody who writes an isolated + + align:start position:0% +is that everybody who writes an isolated + + + align:start position:0% +is that everybody who writes an isolated +action in general doesn't know each any + + align:start position:0% +action in general doesn't know each any + + + align:start position:0% +action in general doesn't know each any +given isolated action doesn't know what + + align:start position:0% +given isolated action doesn't know what + + + align:start position:0% +given isolated action doesn't know what +other actions there are in the system so + + align:start position:0% +other actions there are in the system so + + + align:start position:0% +other actions there are in the system so +you might have you know 25 different + + align:start position:0% +you might have you know 25 different + + + align:start position:0% +you might have you know 25 different +actions all of which are touching the + + align:start position:0% +actions all of which are touching the + + + align:start position:0% +actions all of which are touching the +same data but no single action is aware + + align:start position:0% +same data but no single action is aware + + + align:start position:0% +same data but no single action is aware +of all of these other actions and that's + + align:start position:0% +of all of these other actions and that's + + + align:start position:0% +of all of these other actions and that's +very different from sequence + + align:start position:0% +very different from sequence + + + align:start position:0% +very different from sequence +coordination in sequence coordination + + align:start position:0% +coordination in sequence coordination + + + align:start position:0% +coordination in sequence coordination +you know there's one or two or a small + + align:start position:0% +you know there's one or two or a small + + + align:start position:0% +you know there's one or two or a small +number of threads that are actually + + align:start position:0% +number of threads that are actually + + + align:start position:0% +number of threads that are actually +aware of each other and there's a single + + align:start position:0% +aware of each other and there's a single + + + align:start position:0% +aware of each other and there's a single +programmer that's actually designing + + align:start position:0% +programmer that's actually designing + + + align:start position:0% +programmer that's actually designing +these things to specifically interact + + align:start position:0% +these things to specifically interact + + + align:start position:0% +these things to specifically interact +with each other in some fashion So This + + align:start position:0% +with each other in some fashion So This + + + align:start position:0% +with each other in some fashion So This +Thread runs then this other one runs + + align:start position:0% +Thread runs then this other one runs + + + align:start position:0% +Thread runs then this other one runs +after the data has been produced and so + + align:start position:0% +after the data has been produced and so + + + align:start position:0% +after the data has been produced and so +on so in that sense this kind of + + align:start position:0% +on so in that sense this kind of + + + align:start position:0% +on so in that sense this kind of +isolation is a little harder is is + + align:start position:0% +isolation is a little harder is is + + + align:start position:0% +isolation is a little harder is is +harder to achieve because you want to do + + align:start position:0% +harder to achieve because you want to do + + + align:start position:0% +harder to achieve because you want to do +this you know each individual action + + align:start position:0% +this you know each individual action + + + align:start position:0% +this you know each individual action +doesn't know which other actions there + + align:start position:0% +doesn't know which other actions there + + + align:start position:0% +doesn't know which other actions there +are but yet you want achieve um this + + align:start position:0% +are but yet you want achieve um this + + + align:start position:0% +are but yet you want achieve um this +sequential goal now in one other respect + + align:start position:0% +sequential goal now in one other respect + + + align:start position:0% +sequential goal now in one other respect +actually isolated actions are easier + + align:start position:0% +actually isolated actions are easier + + + align:start position:0% +actually isolated actions are easier +than sequence coordination and the way + + align:start position:0% +than sequence coordination and the way + + + align:start position:0% +than sequence coordination and the way +in which the significant way in which + + align:start position:0% +in which the significant way in which + + + align:start position:0% +in which the significant way in which +they're easier is they're easier for + + align:start position:0% +they're easier is they're easier for + + + align:start position:0% +they're easier is they're easier for +programmers because we're not worried + + align:start position:0% +programmers because we're not worried + + + align:start position:0% +programmers because we're not worried +about coordinating different actions + + align:start position:0% +about coordinating different actions + + + align:start position:0% +about coordinating different actions +with each other the programmers once you + + align:start position:0% +with each other the programmers once you + + + align:start position:0% +with each other the programmers once you +design a system that does underneath + + align:start position:0% +design a system that does underneath + + + align:start position:0% +design a system that does underneath +inside the system that deals with you + + align:start position:0% +inside the system that deals with you + + + align:start position:0% +inside the system that deals with you +know uh ways of achieving isolation the + + align:start position:0% +know uh ways of achieving isolation the + + + align:start position:0% +know uh ways of achieving isolation the +programmers don't have to think about + + align:start position:0% +programmers don't have to think about + + + align:start position:0% +programmers don't have to think about +locks and unlocks and acquiring and + + align:start position:0% +locks and unlocks and acquiring and + + + align:start position:0% +locks and unlocks and acquiring and +releasing locks or other ways in which + + align:start position:0% +releasing locks or other ways in which + + + align:start position:0% +releasing locks or other ways in which +they um um they control access to + + align:start position:0% +they um um they control access to + + + align:start position:0% +they um um they control access to +variables that might be shared so what + + align:start position:0% +variables that might be shared so what + + + align:start position:0% +variables that might be shared so what +this means is that if we can design + + align:start position:0% +this means is that if we can design + + + align:start position:0% +this means is that if we can design +isolated actions right um and we don't + + align:start position:0% +isolated actions right um and we don't + + + align:start position:0% +isolated actions right um and we don't +worry about any serial order you know A1 + + align:start position:0% +worry about any serial order you know A1 + + + align:start position:0% +worry about any serial order you know A1 +can run before A2 or A2 before A1 then + + align:start position:0% +can run before A2 or A2 before A1 then + + + align:start position:0% +can run before A2 or A2 before A1 then +it makes life a lot easier for a + + align:start position:0% +it makes life a lot easier for a + + + align:start position:0% +it makes life a lot easier for a +programmer and our goal is to come up + + align:start position:0% +programmer and our goal is to come up + + + align:start position:0% +programmer and our goal is to come up +with ways of achieving recoverability + + align:start position:0% +with ways of achieving recoverability + + + align:start position:0% +with ways of achieving recoverability +and isolation that require very little + + align:start position:0% +and isolation that require very little + + + align:start position:0% +and isolation that require very little +from a programmer that wants these + + align:start position:0% +from a programmer that wants these + + + align:start position:0% +from a programmer that wants these +properties so in a little it's a little + + align:start position:0% +properties so in a little it's a little + + + align:start position:0% +properties so in a little it's a little +bit like pixie DK you might you might + + align:start position:0% +bit like pixie DK you might you might + + + align:start position:0% +bit like pixie DK you might you might +write a general program and come in and + + align:start position:0% +write a general program and come in and + + + align:start position:0% +write a general program and come in and +just put a begin recoverable action end + + align:start position:0% +just put a begin recoverable action end + + + align:start position:0% +just put a begin recoverable action end +recoverable action and make a few + + align:start position:0% +recoverable action and make a few + + + align:start position:0% +recoverable action and make a few +changes to your program or you might + + align:start position:0% +changes to your program or you might + + + align:start position:0% +changes to your program or you might +just say begin isolated action end + + align:start position:0% +just say begin isolated action end + + + align:start position:0% +just say begin isolated action end +isolated action and magically the system + + align:start position:0% +isolated action and magically the system + + + align:start position:0% +isolated action and magically the system +achieves isolation and recoverability + + align:start position:0% +achieves isolation and recoverability + + + align:start position:0% +achieves isolation and recoverability +for you so it's it's uh it can make life + + align:start position:0% +for you so it's it's uh it can make life + + + align:start position:0% +for you so it's it's uh it can make life +much easier for a programmer but it is a + + align:start position:0% +much easier for a programmer but it is a + + + align:start position:0% +much easier for a programmer but it is a +harder problem for us because no single + + align:start position:0% +harder problem for us because no single + + + align:start position:0% +harder problem for us because no single +action is aware of all of the other + + align:start position:0% +action is aware of all of the other + + + align:start position:0% +action is aware of all of the other +actions in the system so next time we'll + + align:start position:0% +actions in the system so next time we'll + + + align:start position:0% +actions in the system so next time we'll +see how to achieve recoverability and + + align:start position:0% +see how to achieve recoverability and + + + align:start position:0% +see how to achieve recoverability and +then isolation and transactions + + align:start position:0% +then isolation and transactions + + + align:start position:0% +then isolation and transactions +if uh if I gave you a survey might just + + align:start position:0% +if uh if I gave you a survey might just + + + align:start position:0% +if uh if I gave you a survey might just +Cy on your way out as Cy didn't get one + + align:start position:0% +Cy on your way out as Cy didn't get one + + + align:start position:0% +Cy on your way out as Cy didn't get one +and you + + align:start position:0% + + + + align:start position:0% + +like design project 2 is out on the + + align:start position:0% +like design project 2 is out on the + + + align:start position:0% +like design project 2 is out on the +website now and the main thing for you + + align:start position:0% +website now and the main thing for you + + + align:start position:0% +website now and the main thing for you +to make sure you do this week is get + + align:start position:0% +to make sure you do this week is get + + + align:start position:0% +to make sure you do this week is get +project Partners uh and send a list of + + align:start position:0% +project Partners uh and send a list of + + + align:start position:0% +project Partners uh and send a list of +team members to your teaching assistant + + align:start position:0% +team members to your teaching assistant + + + align:start position:0% +team members to your teaching assistant +by Thursday's + + align:start position:0% +by Thursday's + + + align:start position:0% +by Thursday's +recitation thanks \ No newline at end of file diff --git a/OwNr82QgkP8.txt b/OwNr82QgkP8.txt new file mode 100644 index 0000000000000000000000000000000000000000..970bd8fd7e26bae635065738e290eab19884456b --- /dev/null +++ b/OwNr82QgkP8.txt @@ -0,0 +1,275 @@ +align:start position:0% + +so we saw that a conservative force is + + align:start position:0% +so we saw that a conservative force is + + + align:start position:0% +so we saw that a conservative force is +path independent and we also had + + align:start position:0% +path independent and we also had + + + align:start position:0% +path independent and we also had +examples of forces which are path + + align:start position:0% +examples of forces which are path + + + align:start position:0% +examples of forces which are path +dependent if you have path two and path + + align:start position:0% +dependent if you have path two and path + + + align:start position:0% +dependent if you have path two and path +one and the work + + align:start position:0% +one and the work + + + align:start position:0% +one and the work +done is path + + align:start position:0% +done is path + + + align:start position:0% +done is path +dependent so that means for each path we + + align:start position:0% +dependent so that means for each path we + + + align:start position:0% +dependent so that means for each path we +would get a different answer then we + + align:start position:0% +would get a different answer then we + + + align:start position:0% +would get a different answer then we +call this Force F we denote it by NC is + + align:start position:0% +call this Force F we denote it by NC is + + + align:start position:0% +call this Force F we denote it by NC is +called + + align:start position:0% +called + + + align:start position:0% +called +nonconservative + + align:start position:0% +nonconservative + + + align:start position:0% +nonconservative +and again we see that friction is the + + align:start position:0% +and again we see that friction is the + + + align:start position:0% +and again we see that friction is the +best example of a non-conservative force + + align:start position:0% +best example of a non-conservative force + + + align:start position:0% +best example of a non-conservative force +and if we go again for non-conservative + + align:start position:0% +and if we go again for non-conservative + + + align:start position:0% +and if we go again for non-conservative +work if we integrate from the initial + + align:start position:0% +work if we integrate from the initial + + + align:start position:0% +work if we integrate from the initial +point to the final + + align:start position:0% +point to the final + + + align:start position:0% +point to the final +point for instance on our path + + align:start position:0% +point for instance on our path + + + align:start position:0% +point for instance on our path +one of this non-conservative Force so if + + align:start position:0% +one of this non-conservative Force so if + + + align:start position:0% +one of this non-conservative Force so if +we integrate this way and if we + + align:start position:0% +we integrate this way and if we + + + align:start position:0% +we integrate this way and if we +reverse the + + align:start position:0% +reverse the + + + align:start position:0% +reverse the +interval and so we go back from the + + align:start position:0% +interval and so we go back from the + + + align:start position:0% +interval and so we go back from the +final point to the initial point on path + + align:start position:0% +final point to the initial point on path + + + align:start position:0% +final point to the initial point on path +two that these integrals will not be + + align:start position:0% +two that these integrals will not be + + + align:start position:0% +two that these integrals will not be +equal to the negative of each other + + align:start position:0% +equal to the negative of each other + + + align:start position:0% +equal to the negative of each other +because the quantities are different for + + align:start position:0% +because the quantities are different for + + + align:start position:0% +because the quantities are different for +the different paths in general and so + + align:start position:0% +the different paths in general and so + + + align:start position:0% +the different paths in general and so +this is + + align:start position:0% +this is + + + align:start position:0% +this is +nonzero and in fact um that's the + + align:start position:0% +nonzero and in fact um that's the + + + align:start position:0% +nonzero and in fact um that's the +property of non-conservative forces that + + align:start position:0% +property of non-conservative forces that + + + align:start position:0% +property of non-conservative forces that +the work done around the closed + + align:start position:0% +the work done around the closed + + + align:start position:0% +the work done around the closed +path for a non-conservative force is is + + align:start position:0% +path for a non-conservative force is is + + + align:start position:0% +path for a non-conservative force is is +not equal to zero in general there may + + align:start position:0% +not equal to zero in general there may + + + align:start position:0% +not equal to zero in general there may +be one specific closed path in which + + align:start position:0% +be one specific closed path in which + + + align:start position:0% +be one specific closed path in which +that answer is zero but in general it's + + align:start position:0% +that answer is zero but in general it's + + + align:start position:0% +that answer is zero but in general it's +non zero \ No newline at end of file diff --git a/OxcCPTc_bXw.txt b/OxcCPTc_bXw.txt new file mode 100644 index 0000000000000000000000000000000000000000..7bd8829f9ed1e7e31a886c2a1c5e73720b6055af --- /dev/null +++ b/OxcCPTc_bXw.txt @@ -0,0 +1,12070 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right I'm a little slow + + align:start position:0% +ocw.mit.edu all right I'm a little slow + + + align:start position:0% +ocw.mit.edu all right I'm a little slow +getting started today better get going + + align:start position:0% + + + + align:start position:0% + +what we're going to talk about today is + + align:start position:0% +what we're going to talk about today is + + + align:start position:0% +what we're going to talk about today is +a + + align:start position:0% + + + + align:start position:0% + +technique you guys done okay thanks + + align:start position:0% +technique you guys done okay thanks + + + align:start position:0% +technique you guys done okay thanks +we're going to talk about it today is a + + align:start position:0% +we're going to talk about it today is a + + + align:start position:0% +we're going to talk about it today is a +technique known as modal analysis and + + align:start position:0% +technique known as modal analysis and + + + align:start position:0% +technique known as modal analysis and +it's a way of + + align:start position:0% +it's a way of + + + align:start position:0% +it's a way of +analyzing things that vibrate + + align:start position:0% +analyzing things that vibrate + + + align:start position:0% +analyzing things that vibrate +essentially thinking about the one mode + + align:start position:0% +essentially thinking about the one mode + + + align:start position:0% +essentially thinking about the one mode +at a time though you might not make a + + align:start position:0% +at a time though you might not make a + + + align:start position:0% +at a time though you might not make a +lot of use of the actual calculation + + align:start position:0% +lot of use of the actual calculation + + + align:start position:0% +lot of use of the actual calculation +doing the math throughout your careers I + + align:start position:0% +doing the math throughout your careers I + + + align:start position:0% +doing the math throughout your careers I +think if you understand it conceptually + + align:start position:0% +think if you understand it conceptually + + + align:start position:0% +think if you understand it conceptually +it'll help you just have a better + + align:start position:0% +it'll help you just have a better + + + align:start position:0% +it'll help you just have a better +understanding of what vibration is all + + align:start position:0% +understanding of what vibration is all + + + align:start position:0% +understanding of what vibration is all +about just give you some insight to it + + align:start position:0% +about just give you some insight to it + + + align:start position:0% +about just give you some insight to it +that you otherwise wouldn't have so the + + align:start position:0% +that you otherwise wouldn't have so the + + + align:start position:0% +that you otherwise wouldn't have so the +basic concept is that you can model just + + align:start position:0% +basic concept is that you can model just + + + align:start position:0% +basic concept is that you can model just +about any structural vibration as the + + align:start position:0% +about any structural vibration as the + + + align:start position:0% +about any structural vibration as the +summation of the individual + + align:start position:0% +summation of the individual + + + align:start position:0% +summation of the individual +contributions of each what we call + + align:start position:0% +contributions of each what we call + + + align:start position:0% +contributions of each what we call +Natural mode so what we mean by that + + align:start position:0% +Natural mode so what we mean by that + + + align:start position:0% +Natural mode so what we mean by that +let's start by thinking let me say that + + align:start position:0% +let's start by thinking let me say that + + + align:start position:0% +let's start by thinking let me say that +this applies to both continuous systems + + align:start position:0% +this applies to both continuous systems + + + align:start position:0% +this applies to both continuous systems +like vibrating strings or beams or + + align:start position:0% +like vibrating strings or beams or + + + align:start position:0% +like vibrating strings or beams or +buildings as it does to finite degree of + + align:start position:0% +buildings as it does to finite degree of + + + align:start position:0% +buildings as it does to finite degree of +Freedom rigid body systems we've been we + + align:start position:0% +Freedom rigid body systems we've been we + + + align:start position:0% +Freedom rigid body systems we've been we +haven't talked about continuous systems + + align:start position:0% +haven't talked about continuous systems + + + align:start position:0% +haven't talked about continuous systems +I'll do a lecture on + + align:start position:0% +I'll do a lecture on + + + align:start position:0% +I'll do a lecture on +it as the last lecture of the term it's + + align:start position:0% +it as the last lecture of the term it's + + + align:start position:0% +it as the last lecture of the term it's +kind of an enrichment sort of lecture + + align:start position:0% +kind of an enrichment sort of lecture + + + align:start position:0% +kind of an enrichment sort of lecture +but everything I say about finite degree + + align:start position:0% +but everything I say about finite degree + + + align:start position:0% +but everything I say about finite degree +of Freedom systems can be extended to + + align:start position:0% +of Freedom systems can be extended to + + + align:start position:0% +of Freedom systems can be extended to +continuous systems but we'll since we've + + align:start position:0% +continuous systems but we'll since we've + + + align:start position:0% +continuous systems but we'll since we've +been studying rigid bodies and systems + + align:start position:0% +been studying rigid bodies and systems + + + align:start position:0% +been studying rigid bodies and systems +with finite numbers of degrees of + + align:start position:0% +with finite numbers of degrees of + + + align:start position:0% +with finite numbers of degrees of +freedom I'll explain I'll go through + + align:start position:0% +freedom I'll explain I'll go through + + + align:start position:0% +freedom I'll explain I'll go through +this analysis in the context of rigid + + align:start position:0% +this analysis in the context of rigid + + + align:start position:0% +this analysis in the context of rigid +body finite degree of Freedom + + align:start position:0% +body finite degree of Freedom + + + align:start position:0% +body finite degree of Freedom +systems so in general we can write the + + align:start position:0% +systems so in general we can write the + + + align:start position:0% +systems so in general we can write the +equations of + + align:start position:0% + + + + align:start position:0% + +motion for finite degree Freedom systems + + align:start position:0% +motion for finite degree Freedom systems + + + align:start position:0% +motion for finite degree Freedom systems +as + + align:start position:0% +as + + + align:start position:0% +as +a mass Matrix and to keep the kind of + + align:start position:0% +a mass Matrix and to keep the kind of + + + align:start position:0% +a mass Matrix and to keep the kind of +writing down I'm just going to + + align:start position:0% +writing down I'm just going to + + + align:start position:0% +writing down I'm just going to +underline matrices and a squiggle under + + align:start position:0% +underline matrices and a squiggle under + + + align:start position:0% +underline matrices and a squiggle under +Vector so we have a in general we can + + align:start position:0% +Vector so we have a in general we can + + + align:start position:0% +Vector so we have a in general we can +write the equations of motion it's a + + align:start position:0% +write the equations of motion it's a + + + align:start position:0% +write the equations of motion it's a +mass Matrix times a an acceleration + + align:start position:0% +mass Matrix times a an acceleration + + + align:start position:0% +mass Matrix times a an acceleration +vector plus a damping Matrix times the + + align:start position:0% +vector plus a damping Matrix times the + + + align:start position:0% +vector plus a damping Matrix times the +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +Vector stiffness Matrix times a + + align:start position:0% +Vector stiffness Matrix times a + + + align:start position:0% +Vector stiffness Matrix times a +displacement Vector all equal to some + + align:start position:0% +displacement Vector all equal to some + + + align:start position:0% +displacement Vector all equal to some +external Vector of x itations now I'm + + align:start position:0% +external Vector of x itations now I'm + + + align:start position:0% +external Vector of x itations now I'm +writing these as if these are + + align:start position:0% +writing these as if these are + + + align:start position:0% +writing these as if these are +translations but you know like from + + align:start position:0% +translations but you know like from + + + align:start position:0% +translations but you know like from +doing the cart the pendulum on the cart + + align:start position:0% +doing the cart the pendulum on the cart + + + align:start position:0% +doing the cart the pendulum on the cart +problem that the equations of motion + + align:start position:0% +problem that the equations of motion + + + align:start position:0% +problem that the equations of motion +might involve rotations and + + align:start position:0% +might involve rotations and + + + align:start position:0% +might involve rotations and +displacements and we let them you know + + align:start position:0% +displacements and we let them you know + + + align:start position:0% +displacements and we let them you know +they mix together here however they fall + + align:start position:0% +they mix together here however they fall + + + align:start position:0% +they mix together here however they fall +out but just to write them symbolically + + align:start position:0% +out but just to write them symbolically + + + align:start position:0% +out but just to write them symbolically +I'm just going to call them all refer to + + align:start position:0% +I'm just going to call them all refer to + + + align:start position:0% +I'm just going to call them all refer to +all of those coordinates with an X + + align:start position:0% +all of those coordinates with an X + + + align:start position:0% +all of those coordinates with an X +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +okay now the basic + + align:start position:0% +okay now the basic + + + align:start position:0% +okay now the basic +premise of modal analysis is a thing + + align:start position:0% +premise of modal analysis is a thing + + + align:start position:0% +premise of modal analysis is a thing +called the + + align:start position:0% + + + + align:start position:0% + +modal expansion + + align:start position:0% + + + + align:start position:0% + +theorem it's basically the assertion + + align:start position:0% +theorem it's basically the assertion + + + align:start position:0% +theorem it's basically the assertion +that you can + + align:start position:0% +that you can + + + align:start position:0% +that you can +represent any motion set of vectors I'll + + align:start position:0% +represent any motion set of vectors I'll + + + align:start position:0% +represent any motion set of vectors I'll +write them kind of as a vector here for + + align:start position:0% +write them kind of as a vector here for + + + align:start position:0% +write them kind of as a vector here for +a moment + + align:start position:0% +a moment + + + align:start position:0% +a moment +any set of of motions X as the + + align:start position:0% + + + + align:start position:0% + +superposition + + align:start position:0% +superposition + + + align:start position:0% +superposition +of each contributing mode now each mode + + align:start position:0% +of each contributing mode now each mode + + + align:start position:0% +of each contributing mode now each mode +has a mode shape to it which I'm going + + align:start position:0% +has a mode shape to it which I'm going + + + align:start position:0% +has a mode shape to it which I'm going +to call + + align:start position:0% +to call + + + align:start position:0% +to call +U and up here I put a superscript For + + align:start position:0% +U and up here I put a superscript For + + + align:start position:0% +U and up here I put a superscript For +What mode it is the first mode times its + + align:start position:0% +What mode it is the first mode times its + + + align:start position:0% +What mode it is the first mode times its +time dependent behavior and this is + + align:start position:0% +time dependent behavior and this is + + + align:start position:0% +time dependent behavior and this is +called what they call in textbooks these + + align:start position:0% +called what they call in textbooks these + + + align:start position:0% +called what they call in textbooks these +are called the natural + + align:start position:0% +are called the natural + + + align:start position:0% +are called the natural +coordinates and we'll see what those are + + align:start position:0% +coordinates and we'll see what those are + + + align:start position:0% +coordinates and we'll see what those are +in a second so mode shape one this is + + align:start position:0% +in a second so mode shape one this is + + + align:start position:0% +in a second so mode shape one this is +the time dependent and amplitude part + + align:start position:0% +the time dependent and amplitude part + + + align:start position:0% +the time dependent and amplitude part +that says how much the contribution of + + align:start position:0% +that says how much the contribution of + + + align:start position:0% +that says how much the contribution of +mode one is to this motion and what its + + align:start position:0% +mode one is to this motion and what its + + + align:start position:0% +mode one is to this motion and what its +time dependence is this is and then + + align:start position:0% +time dependence is this is and then + + + align:start position:0% +time dependence is this is and then +you'd have mode 2's + + align:start position:0% + + + + align:start position:0% + +contribution Q2 + + align:start position:0% + + + + align:start position:0% + +and this goes out to the nth + + align:start position:0% +and this goes out to the nth + + + align:start position:0% +and this goes out to the nth +modes + + align:start position:0% +modes + + + align:start position:0% +modes +contribution + + align:start position:0% +contribution + + + align:start position:0% +contribution +qn of T and that's the proposition that + + align:start position:0% +qn of T and that's the proposition that + + + align:start position:0% +qn of T and that's the proposition that +you can represent the total response of + + align:start position:0% +you can represent the total response of + + + align:start position:0% +you can represent the total response of +the system as a superposition of the + + align:start position:0% +the system as a superposition of the + + + align:start position:0% +the system as a superposition of the +response of each of the natural modes of + + align:start position:0% +response of each of the natural modes of + + + align:start position:0% +response of each of the natural modes of +the system and if it's an in degree of + + align:start position:0% +the system and if it's an in degree of + + + align:start position:0% +the system and if it's an in degree of +Freedom system there'll be in natural + + align:start position:0% +Freedom system there'll be in natural + + + align:start position:0% +Freedom system there'll be in natural +mode so + + align:start position:0% + + + + align:start position:0% + +now something I didn't say here is this + + align:start position:0% +now something I didn't say here is this + + + align:start position:0% +now something I didn't say here is this +is all this all assumes that the system + + align:start position:0% +is all this all assumes that the system + + + align:start position:0% +is all this all assumes that the system +vibrates so this is this is all in the + + align:start position:0% +vibrates so this is this is all in the + + + align:start position:0% +vibrates so this is this is all in the +discussion of things that exhibit + + align:start position:0% +discussion of things that exhibit + + + align:start position:0% +discussion of things that exhibit +vibratory motion so this is + + align:start position:0% + + + + align:start position:0% + +all should see here of + + align:start position:0% + + + + align:start position:0% + +vibrating + + align:start position:0% + + + + align:start position:0% + +systems + + align:start position:0% + + + + align:start position:0% + +okay so this is kind of a long and + + align:start position:0% +okay so this is kind of a long and + + + align:start position:0% +okay so this is kind of a long and +cumbersome way of writing this out so if + + align:start position:0% +cumbersome way of writing this out so if + + + align:start position:0% +cumbersome way of writing this out so if +you + + align:start position:0% +you + + + align:start position:0% +you +notice each one of these is the mode + + align:start position:0% +notice each one of these is the mode + + + align:start position:0% +notice each one of these is the mode +shaped vector and if I put them together + + align:start position:0% +shaped vector and if I put them together + + + align:start position:0% +shaped vector and if I put them together +in a matrix it would look just side by + + align:start position:0% +in a matrix it would look just side by + + + align:start position:0% +in a matrix it would look just side by +side here's a + + align:start position:0% +side here's a + + + align:start position:0% +side here's a +U1 over two u + + align:start position:0% +U1 over two u + + + align:start position:0% +U1 over two u +n and multiply it by this Vector q1 of + + align:start position:0% +n and multiply it by this Vector q1 of + + + align:start position:0% +n and multiply it by this Vector q1 of +T down to + + align:start position:0% + + + + align:start position:0% + +qn that's the same statement but said in + + align:start position:0% +qn that's the same statement but said in + + + align:start position:0% +qn that's the same statement but said in +a much more compact + + align:start position:0% +a much more compact + + + align:start position:0% +a much more compact +way so the statement this modal + + align:start position:0% +way so the statement this modal + + + align:start position:0% +way so the statement this modal +expansion theorem basically says the + + align:start position:0% +expansion theorem basically says the + + + align:start position:0% +expansion theorem basically says the +vector of + + align:start position:0% +vector of + + + align:start position:0% +vector of +these are + + align:start position:0% +these are + + + align:start position:0% +these are +your generalized + + align:start position:0% + + + + align:start position:0% + +coordinates which we've been using all + + align:start position:0% +coordinates which we've been using all + + + align:start position:0% +coordinates which we've been using all +term long these are the generalized + + align:start position:0% +term long these are the generalized + + + align:start position:0% +term long these are the generalized +coordinates that you choose to derive + + align:start position:0% +coordinates that you choose to derive + + + align:start position:0% +coordinates that you choose to derive +the equations of motion around the + + align:start position:0% +the equations of motion around the + + + align:start position:0% +the equations of motion around the +vector of generalized coordinates can be + + align:start position:0% +vector of generalized coordinates can be + + + align:start position:0% +vector of generalized coordinates can be +written as u + + align:start position:0% +written as u + + + align:start position:0% +written as u +q and these are often called the + + align:start position:0% +q and these are often called the + + + align:start position:0% +q and these are often called the +modal coordin + + align:start position:0% +modal coordin + + + align:start position:0% +modal coordin +coordinates or sometimes called the + + align:start position:0% +coordinates or sometimes called the + + + align:start position:0% +coordinates or sometimes called the +natural + + align:start position:0% + + + + align:start position:0% + +coordinates + + align:start position:0% + + + + align:start position:0% + +okay so if we can say that + + align:start position:0% +okay so if we can say that + + + align:start position:0% +okay so if we can say that +X is u q then x dot you take the Der + + align:start position:0% +X is u q then x dot you take the Der + + + align:start position:0% +X is u q then x dot you take the Der +ative of each one of those expressions + + align:start position:0% +ative of each one of those expressions + + + align:start position:0% +ative of each one of those expressions +you'll find that going to be u q + + align:start position:0% +you'll find that going to be u q + + + align:start position:0% +you'll find that going to be u q +Dot and X double dot = u q double dot + + align:start position:0% +Dot and X double dot = u q double dot + + + align:start position:0% +Dot and X double dot = u q double dot +because these are just constants the + + align:start position:0% +because these are just constants the + + + align:start position:0% +because these are just constants the +mode shape vectors are just a fixed set + + align:start position:0% +mode shape vectors are just a fixed set + + + align:start position:0% +mode shape vectors are just a fixed set +of numbers that represent the mode + + align:start position:0% +of numbers that represent the mode + + + align:start position:0% +of numbers that represent the mode +shapes of the system now just to uh I + + align:start position:0% +shapes of the system now just to uh I + + + align:start position:0% +shapes of the system now just to uh I +think maybe this a good time to do this + + align:start position:0% +think maybe this a good time to do this + + + align:start position:0% +think maybe this a good time to do this +you grabb one end + + align:start position:0% + + + + align:start position:0% + +so this is a and it's hard to see black + + align:start position:0% +so this is a and it's hard to see black + + + align:start position:0% +so this is a and it's hard to see black +against black my apologies for that but + + align:start position:0% +against black my apologies for that but + + + align:start position:0% +against black my apologies for that but +so this is a guitar + + align:start position:0% +so this is a guitar + + + align:start position:0% +so this is a guitar +string or um you know any stringed + + align:start position:0% +string or um you know any stringed + + + align:start position:0% +string or um you know any stringed +instrument or in fact any long slender + + align:start position:0% +instrument or in fact any long slender + + + align:start position:0% +instrument or in fact any long slender +thing under tension will vibrate and it + + align:start position:0% +thing under tension will vibrate and it + + + align:start position:0% +thing under tension will vibrate and it +has if I do this carefully that's called + + align:start position:0% +has if I do this carefully that's called + + + align:start position:0% +has if I do this carefully that's called +the + + align:start position:0% +the + + + align:start position:0% +the +first mode of + + align:start position:0% +first mode of + + + align:start position:0% +first mode of +vibration and that's when you pluck your + + align:start position:0% +vibration and that's when you pluck your + + + align:start position:0% +vibration and that's when you pluck your +guitar string or violin in the middle + + align:start position:0% +guitar string or violin in the middle + + + align:start position:0% +guitar string or violin in the middle +you mostly hear that + + align:start position:0% +you mostly hear that + + + align:start position:0% +you mostly hear that +and but at twice the frequency if I can + + align:start position:0% +and but at twice the frequency if I can + + + align:start position:0% +and but at twice the frequency if I can +get it going + + align:start position:0% +get it going + + + align:start position:0% +get it going +here there's the second mode of + + align:start position:0% +here there's the second mode of + + + align:start position:0% +here there's the second mode of +vibration and for a taut string it's it + + align:start position:0% +vibration and for a taut string it's it + + + align:start position:0% +vibration and for a taut string it's it +happens to be at twice the frequency of + + align:start position:0% +happens to be at twice the frequency of + + + align:start position:0% +happens to be at twice the frequency of +the first and if I my hand is well + + align:start position:0% +the first and if I my hand is well + + + align:start position:0% +the first and if I my hand is well +calibrated today may be easier it's a + + align:start position:0% +calibrated today may be easier it's a + + + align:start position:0% +calibrated today may be easier it's a +little longer I get this going + + align:start position:0% +little longer I get this going + + + align:start position:0% +little longer I get this going +right ah there's a third mode + + align:start position:0% + + + + align:start position:0% + +okay so each that's what + + align:start position:0% +okay so each that's what + + + align:start position:0% +okay so each that's what +we that's what we're calling oh what I + + align:start position:0% +we that's what we're calling oh what I + + + align:start position:0% +we that's what we're calling oh what I +meant to say when I was doing this is + + align:start position:0% +meant to say when I was doing this is + + + align:start position:0% +meant to say when I was doing this is +these shapes for the vibrating string + + align:start position:0% +these shapes for the vibrating string + + + align:start position:0% +these shapes for the vibrating string +that second mode shape happens to be one + + align:start position:0% +that second mode shape happens to be one + + + align:start position:0% +that second mode shape happens to be one +full sine wave and the mode shape has + + align:start position:0% +full sine wave and the mode shape has + + + align:start position:0% +full sine wave and the mode shape has +the form sin n pi x over L where L's the + + align:start position:0% +the form sin n pi x over L where L's the + + + align:start position:0% +the form sin n pi x over L where L's the +length of the string 's the mode number + + align:start position:0% +length of the string 's the mode number + + + align:start position:0% +length of the string 's the mode number +so first mode second mode is this when n + + align:start position:0% +so first mode second mode is this when n + + + align:start position:0% +so first mode second mode is this when n +is two first mode n is one nth mode or + + align:start position:0% +is two first mode n is one nth mode or + + + align:start position:0% +is two first mode n is one nth mode or +something High you know you get higher + + align:start position:0% +something High you know you get higher + + + align:start position:0% +something High you know you get higher +modes like that so these are the mode + + align:start position:0% +modes like that so these are the mode + + + align:start position:0% +modes like that so these are the mode +shapes for a vibrating + + align:start position:0% +shapes for a vibrating + + + align:start position:0% +shapes for a vibrating +string so that's and this that's good + + align:start position:0% +string so that's and this that's good + + + align:start position:0% +string so that's and this that's good +for + + align:start position:0% +for + + + align:start position:0% +for +now this this uh two degree of Freedom + + align:start position:0% +now this this uh two degree of Freedom + + + align:start position:0% +now this this uh two degree of Freedom +system with the two lump masses and it's + + align:start position:0% +system with the two lump masses and it's + + + align:start position:0% +system with the two lump masses and it's +going to show up there y okay this is + + align:start position:0% +going to show up there y okay this is + + + align:start position:0% +going to show up there y okay this is +basically two Lum masses and we idealize + + align:start position:0% +basically two Lum masses and we idealize + + + align:start position:0% +basically two Lum masses and we idealize +the Springs as being massless but it's a + + align:start position:0% +the Springs as being massless but it's a + + + align:start position:0% +the Springs as being massless but it's a +pretty good approximation this has two + + align:start position:0% +pretty good approximation this has two + + + align:start position:0% +pretty good approximation this has two +modes of vibration and Professor goser + + align:start position:0% +modes of vibration and Professor goser + + + align:start position:0% +modes of vibration and Professor goser +made these neat + + align:start position:0% + + + + align:start position:0% + +little things that can make it so and I + + align:start position:0% +little things that can make it so and I + + + align:start position:0% +little things that can make it so and I +I'm going to come back to this but + + align:start position:0% +I'm going to come back to this but + + + align:start position:0% +I'm going to come back to this but +there's mode + + align:start position:0% +there's mode + + + align:start position:0% +there's mode +one and the mode shape is as this goes + + align:start position:0% +one and the mode shape is as this goes + + + align:start position:0% +one and the mode shape is as this goes +down one unit that goes down about two + + align:start position:0% +down one unit that goes down about two + + + align:start position:0% +down one unit that goes down about two +two times as much I give you the exact + + align:start position:0% +two times as much I give you the exact + + + align:start position:0% +two times as much I give you the exact +numberers in a minute and the other mode + + align:start position:0% +numberers in a minute and the other mode + + + align:start position:0% +numberers in a minute and the other mode +shape of the + + align:start position:0% + + + + align:start position:0% + +system I do the right in if I give it + + align:start position:0% +system I do the right in if I give it + + + align:start position:0% +system I do the right in if I give it +the right initial we're going to talk + + align:start position:0% +the right initial we're going to talk + + + align:start position:0% +the right initial we're going to talk +about this today and why this happens + + align:start position:0% +about this today and why this happens + + + align:start position:0% +about this today and why this happens +but if I give it the right initial + + align:start position:0% +but if I give it the right initial + + + align:start position:0% +but if I give it the right initial +conditions I can make it vibrate only in + + align:start position:0% +conditions I can make it vibrate only in + + + align:start position:0% +conditions I can make it vibrate only in +the second mode shape and so it's now + + align:start position:0% +the second mode shape and so it's now + + + align:start position:0% +the second mode shape and so it's now +deflected with the right condition so + + align:start position:0% +deflected with the right condition so + + + align:start position:0% +deflected with the right condition so +that it'll respond only in second + + align:start position:0% +that it'll respond only in second + + + align:start position:0% +that it'll respond only in second +mode this Mass goes up and down a lot + + align:start position:0% +mode this Mass goes up and down a lot + + + align:start position:0% +mode this Mass goes up and down a lot +that mass goes up and down a little + + align:start position:0% +that mass goes up and down a little + + + align:start position:0% +that mass goes up and down a little +opposite to it actually the frequency is + + align:start position:0% +opposite to it actually the frequency is + + + align:start position:0% +opposite to it actually the frequency is +different from the first but if this is + + align:start position:0% +different from the first but if this is + + + align:start position:0% +different from the first but if this is +moving one unit then this down here is + + align:start position:0% +moving one unit then this down here is + + + align:start position:0% +moving one unit then this down here is +moving minus. 3 or something like that + + align:start position:0% +moving minus. 3 or something like that + + + align:start position:0% +moving minus. 3 or something like that +and that ratio is constant and that's + + align:start position:0% +and that ratio is constant and that's + + + align:start position:0% +and that ratio is constant and that's +called the mode shape so if you just + + align:start position:0% +called the mode shape so if you just + + + align:start position:0% +called the mode shape so if you just +pick one of them and say Let its motion + + align:start position:0% +pick one of them and say Let its motion + + + align:start position:0% +pick one of them and say Let its motion +be one then all of the other masses in + + align:start position:0% +be one then all of the other masses in + + + align:start position:0% +be one then all of the other masses in +the system will move in a particular + + align:start position:0% +the system will move in a particular + + + align:start position:0% +the system will move in a particular +ratio to the motion of that one that you + + align:start position:0% +ratio to the motion of that one that you + + + align:start position:0% +ratio to the motion of that one that you +arbitrarily set to one so this will mean + + align:start position:0% +arbitrarily set to one so this will mean + + + align:start position:0% +arbitrarily set to one so this will mean +by mode shapes and their natural + + align:start position:0% +by mode shapes and their natural + + + align:start position:0% +by mode shapes and their natural +frequencies there's the natural + + align:start position:0% +frequencies there's the natural + + + align:start position:0% +frequencies there's the natural +frequency associated with that first + + align:start position:0% +frequency associated with that first + + + align:start position:0% +frequency associated with that first +mode and we can solve these things + + align:start position:0% +mode and we can solve these things + + + align:start position:0% +mode and we can solve these things +mathematically and we've been doing that + + align:start position:0% +mathematically and we've been doing that + + + align:start position:0% +mathematically and we've been doing that +a little uh a little bit in the last + + align:start position:0% +a little uh a little bit in the last + + + align:start position:0% +a little uh a little bit in the last +couple of + + align:start position:0% + + + + align:start position:0% + +lectures all + + align:start position:0% + + + + align:start position:0% + +right so this is the relationship + + align:start position:0% +right so this is the relationship + + + align:start position:0% +right so this is the relationship +between these thing the generalized + + align:start position:0% +between these thing the generalized + + + align:start position:0% +between these thing the generalized +coordinates and the modal + + align:start position:0% +coordinates and the modal + + + align:start position:0% +coordinates and the modal +coordinates and we now need to um + + align:start position:0% + + + + align:start position:0% + +see how we are going to use + + align:start position:0% + + + + align:start position:0% + +these so in general we have our + + align:start position:0% +these so in general we have our + + + align:start position:0% +these so in general we have our +equations of + + align:start position:0% + + + + align:start position:0% + +motion and I'm going to substitute + + align:start position:0% +motion and I'm going to substitute + + + align:start position:0% +motion and I'm going to substitute +for XX Dot and xou Dot + + align:start position:0% +for XX Dot and xou Dot + + + align:start position:0% +for XX Dot and xou Dot +these + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +and + + align:start position:0% +and + + + align:start position:0% +and +pre + + align:start position:0% +pre + + + align:start position:0% +pre +multiply by U transpose remember the + + align:start position:0% +multiply by U transpose remember the + + + align:start position:0% +multiply by U transpose remember the +transpose of a matrix you just take the + + align:start position:0% +transpose of a matrix you just take the + + + align:start position:0% +transpose of a matrix you just take the +column First Column make it the first + + align:start position:0% +column First Column make it the first + + + align:start position:0% +column First Column make it the first +row second column make it the second row + + align:start position:0% +row second column make it the second row + + + align:start position:0% +row second column make it the second row +so if I plug in these up here I get + + align:start position:0% +so if I plug in these up here I get + + + align:start position:0% +so if I plug in these up here I get +m u + + align:start position:0% + + + + align:start position:0% + +q going leave some space here because + + align:start position:0% +q going leave some space here because + + + align:start position:0% +q going leave some space here because +I'm going to pre-multiply in a second + + align:start position:0% +I'm going to pre-multiply in a second + + + align:start position:0% +I'm going to pre-multiply in a second +plus + + align:start position:0% +plus + + + align:start position:0% +plus +c + + align:start position:0% +c + + + align:start position:0% +c +u q dot plus k a + + align:start position:0% +u q dot plus k a + + + align:start position:0% +u q dot plus k a +u q + + align:start position:0% + + + + align:start position:0% + +equals the external exciting forces now + + align:start position:0% +equals the external exciting forces now + + + align:start position:0% +equals the external exciting forces now +I'm going to pre-multiply by U + + align:start position:0% + + + + align:start position:0% + +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +okay now a remarkable thing happens + + align:start position:0% +okay now a remarkable thing happens + + + align:start position:0% +okay now a remarkable thing happens +it happens that if you take when you + + align:start position:0% +it happens that if you take when you + + + align:start position:0% +it happens that if you take when you +when you do this calculation when you + + align:start position:0% +when you do this calculation when you + + + align:start position:0% +when you do this calculation when you +multiply this Matrix times that one row + + align:start position:0% +multiply this Matrix times that one row + + + align:start position:0% +multiply this Matrix times that one row +at a time so this has this has vectors + + align:start position:0% +at a time so this has this has vectors + + + align:start position:0% +at a time so this has this has vectors +in it one through n I'm going to pick + + align:start position:0% +in it one through n I'm going to pick + + + align:start position:0% +in it one through n I'm going to pick +Vector R the rth one if I take that arth + + align:start position:0% +Vector R the rth one if I take that arth + + + align:start position:0% +Vector R the rth one if I take that arth +vector and multiply it one at a time by + + align:start position:0% +vector and multiply it one at a time by + + + align:start position:0% +vector and multiply it one at a time by +row by row by + + align:start position:0% +row by row by + + + align:start position:0% +row by row by +row then I get + + align:start position:0% +row then I get + + + align:start position:0% +row then I get +a + + align:start position:0% +a + + + align:start position:0% +a +new vector that results which I'm going + + align:start position:0% +new vector that results which I'm going + + + align:start position:0% +new vector that results which I'm going +to multiply by this so if I'm going to + + align:start position:0% +to multiply by this so if I'm going to + + + align:start position:0% +to multiply by this so if I'm going to +but I'm I'm going to pick out one of the + + align:start position:0% +but I'm I'm going to pick out one of the + + + align:start position:0% +but I'm I'm going to pick out one of the +vectors multiplied through times one of + + align:start position:0% + + + + align:start position:0% + +the uh rows here which is all when you + + align:start position:0% +the uh rows here which is all when you + + + align:start position:0% +the uh rows here which is all when you +transpose them the rows are now the + + align:start position:0% +transpose them the rows are now the + + + align:start position:0% +transpose them the rows are now the +vectors so I'm going to pick if I do the + + align:start position:0% + + + + align:start position:0% + +calculation lost my right piece of paper + + align:start position:0% +calculation lost my right piece of paper + + + align:start position:0% +calculation lost my right piece of paper +here + + align:start position:0% + + + + align:start position:0% + +so I just pull this pull out one of + + align:start position:0% +so I just pull this pull out one of + + + align:start position:0% +so I just pull this pull out one of +these com one of the calculations that + + align:start position:0% +these com one of the calculations that + + + align:start position:0% +these com one of the calculations that +you end up doing is you do this whole + + align:start position:0% +you end up doing is you do this whole + + + align:start position:0% +you end up doing is you do this whole +triple Matrix M + + align:start position:0% +triple Matrix M + + + align:start position:0% +triple Matrix M +multiplication um there will you need to + + align:start position:0% +multiplication um there will you need to + + + align:start position:0% +multiplication um there will you need to +know the following fact + + align:start position:0% +know the following fact + + + align:start position:0% +know the following fact +so for mode the mode s transpose that's + + align:start position:0% +so for mode the mode s transpose that's + + + align:start position:0% +so for mode the mode s transpose that's +one of the rows out of + + align:start position:0% +one of the rows out of + + + align:start position:0% +one of the rows out of +here time + + align:start position:0% +here time + + + align:start position:0% +here time +M times one of the columns the arth + + align:start position:0% +M times one of the columns the arth + + + align:start position:0% +M times one of the columns the arth +one from + + align:start position:0% +one from + + + align:start position:0% +one from +here and I do this calculation this is + + align:start position:0% +here and I do this calculation this is + + + align:start position:0% +here and I do this calculation this is +zero + + align:start position:0% +zero + + + align:start position:0% +zero +for R not equal to + + align:start position:0% +for R not equal to + + + align:start position:0% +for R not equal to +S what that statement says is the only + + align:start position:0% +S what that statement says is the only + + + align:start position:0% +S what that statement says is the only +nonzero result from this is the is when + + align:start position:0% +nonzero result from this is the is when + + + align:start position:0% +nonzero result from this is the is when +you multiply when you take the arth + + align:start position:0% +you multiply when you take the arth + + + align:start position:0% +you multiply when you take the arth +column from here and you use the AR Row + + align:start position:0% +column from here and you use the AR Row + + + align:start position:0% +column from here and you use the AR Row +from here all the other combinations of + + align:start position:0% +from here all the other combinations of + + + align:start position:0% +from here all the other combinations of +this thing go to zero and the net result + + align:start position:0% +this thing go to zero and the net result + + + align:start position:0% +this thing go to zero and the net result +of that is that this implies that U + + align:start position:0% +of that is that this implies that U + + + align:start position:0% +of that is that this implies that U +transpose mu + + align:start position:0% +transpose mu + + + align:start position:0% +transpose mu +U + + align:start position:0% +U + + + align:start position:0% +U +always equals to a + + align:start position:0% +always equals to a + + + align:start position:0% +always equals to a +diagonal Vector which I would call this + + align:start position:0% +diagonal Vector which I would call this + + + align:start position:0% +diagonal Vector which I would call this +like + + align:start position:0% +like + + + align:start position:0% +like +that sometimes a mass Matrix is diagonal + + align:start position:0% +that sometimes a mass Matrix is diagonal + + + align:start position:0% +that sometimes a mass Matrix is diagonal +to start with but even if it isn't you + + align:start position:0% +to start with but even if it isn't you + + + align:start position:0% +to start with but even if it isn't you +do this calculation it will produce a + + align:start position:0% +do this calculation it will produce a + + + align:start position:0% +do this calculation it will produce a +diagonal matrix and that's because this + + align:start position:0% +diagonal matrix and that's because this + + + align:start position:0% +diagonal matrix and that's because this +is this these multiplications are always + + align:start position:0% +is this these multiplications are always + + + align:start position:0% +is this these multiplications are always +zero unless R is the same as + + align:start position:0% +zero unless R is the same as + + + align:start position:0% +zero unless R is the same as +s and the same is true for U transpose k + + align:start position:0% +s and the same is true for U transpose k + + + align:start position:0% +s and the same is true for U transpose k +u will give you + + align:start position:0% +u will give you + + + align:start position:0% +u will give you +a a k Matrix + + align:start position:0% +a a k Matrix + + + align:start position:0% +a a k Matrix +that is diagonal and you know normal for + + align:start position:0% +that is diagonal and you know normal for + + + align:start position:0% +that is diagonal and you know normal for +when the stiffest Matrix we've come up + + align:start position:0% +when the stiffest Matrix we've come up + + + align:start position:0% +when the stiffest Matrix we've come up +with they've generally not been they've + + align:start position:0% +with they've generally not been they've + + + align:start position:0% +with they've generally not been they've +generally been full matrices often times + + align:start position:0% +generally been full matrices often times + + + align:start position:0% +generally been full matrices often times +but you do u k u KU U you will get a + + align:start position:0% +but you do u k u KU U you will get a + + + align:start position:0% +but you do u k u KU U you will get a +diagonal stiffness + + align:start position:0% + + + + align:start position:0% + +Matrix and the problem there the little + + align:start position:0% +Matrix and the problem there the little + + + align:start position:0% +Matrix and the problem there the little +problem comes because youu transpose c + + align:start position:0% + + + + align:start position:0% + +u well sometimes + + align:start position:0% + + + + align:start position:0% + +this one is diagonal only + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +ideal conditions of damping so we're + + align:start position:0% +ideal conditions of damping so we're + + + align:start position:0% +ideal conditions of damping so we're +going to have that's something you just + + align:start position:0% +going to have that's something you just + + + align:start position:0% +going to have that's something you just +have to address + + align:start position:0% + + + + align:start position:0% + +so only for ideal conditions and that's + + align:start position:0% +so only for ideal conditions and that's + + + align:start position:0% +so only for ideal conditions and that's +just something you have to deal + + align:start position:0% + + + + align:start position:0% + +with so this why is this why is this got + + align:start position:0% +with so this why is this why is this got + + + align:start position:0% +with so this why is this why is this got +you know why is there this special + + align:start position:0% +you know why is there this special + + + align:start position:0% +you know why is there this special +wonderful thing the the natural + + align:start position:0% +wonderful thing the the natural + + + align:start position:0% +wonderful thing the the natural +modes of a system this one is a two + + align:start position:0% +modes of a system this one is a two + + + align:start position:0% +modes of a system this one is a two +degree Freedom system form a complete + + align:start position:0% +degree Freedom system form a complete + + + align:start position:0% +degree Freedom system form a complete +and independent set of + + align:start position:0% +and independent set of + + + align:start position:0% +and independent set of +vectors and in this case of this two + + align:start position:0% +vectors and in this case of this two + + + align:start position:0% +vectors and in this case of this two +degree Freedom system I can pick any any + + align:start position:0% +degree Freedom system I can pick any any + + + align:start position:0% +degree Freedom system I can pick any any +allow any kinematically allowable + + align:start position:0% +allow any kinematically allowable + + + align:start position:0% +allow any kinematically allowable +position like + + align:start position:0% +position like + + + align:start position:0% +position like +this stationary static is static is one + + align:start position:0% +this stationary static is static is one + + + align:start position:0% +this stationary static is static is one +of the solutions right to this two + + align:start position:0% +of the solutions right to this two + + + align:start position:0% +of the solutions right to this two +degree freom systems so any any possible + + align:start position:0% +degree freom systems so any any possible + + + align:start position:0% +degree freom systems so any any possible +allowable position of these two things + + align:start position:0% +allowable position of these two things + + + align:start position:0% +allowable position of these two things +static or moving can be + + align:start position:0% +static or moving can be + + + align:start position:0% +static or moving can be +described by a linear combination of the + + align:start position:0% +described by a linear combination of the + + + align:start position:0% +described by a linear combination of the +mode shapes of the system a weighted sum + + align:start position:0% +mode shapes of the system a weighted sum + + + align:start position:0% +mode shapes of the system a weighted sum +of the mode shapes of the system and + + align:start position:0% +of the mode shapes of the system and + + + align:start position:0% +of the mode shapes of the system and +that's all it takes so this one has two + + align:start position:0% +that's all it takes so this one has two + + + align:start position:0% +that's all it takes so this one has two +mode shapes you know one that looks kind + + align:start position:0% +mode shapes you know one that looks kind + + + align:start position:0% +mode shapes you know one that looks kind +of like that one that looks like this + + align:start position:0% +of like that one that looks like this + + + align:start position:0% +of like that one that looks like this +one's going down this one's going up + + align:start position:0% +one's going down this one's going up + + + align:start position:0% +one's going down this one's going up +there are + + align:start position:0% +there are + + + align:start position:0% +there are +particular + + align:start position:0% +particular + + + align:start position:0% +particular +ratios and I can take a weighted amount + + align:start position:0% +ratios and I can take a weighted amount + + + align:start position:0% +ratios and I can take a weighted amount +of that first mode so much of it and a + + align:start position:0% +of that first mode so much of it and a + + + align:start position:0% +of that first mode so much of it and a +weighted amount of the second mode and + + align:start position:0% +weighted amount of the second mode and + + + align:start position:0% +weighted amount of the second mode and +add them together and describe any + + align:start position:0% +add them together and describe any + + + align:start position:0% +add them together and describe any +possible position of the system the same + + align:start position:0% +possible position of the system the same + + + align:start position:0% +possible position of the system the same +thing is true of that strength + + align:start position:0% +thing is true of that strength + + + align:start position:0% +thing is true of that strength +it has mode shapes that are sine wise + + align:start position:0% +it has mode shapes that are sine wise + + + align:start position:0% +it has mode shapes that are sine wise +but they you know sin 1 pix sin 2 pix + + align:start position:0% +but they you know sin 1 pix sin 2 pix + + + align:start position:0% +but they you know sin 1 pix sin 2 pix +over L and so forth any possible linear + + align:start position:0% +over L and so forth any possible linear + + + align:start position:0% +over L and so forth any possible linear +any possible allowable shape of that + + align:start position:0% +any possible allowable shape of that + + + align:start position:0% +any possible allowable shape of that +guitar string can be made up of a + + align:start position:0% +guitar string can be made up of a + + + align:start position:0% +guitar string can be made up of a +weighted sum of the mode shapes of the + + align:start position:0% +weighted sum of the mode shapes of the + + + align:start position:0% +weighted sum of the mode shapes of the +system and moreover the mode + + align:start position:0% +system and moreover the mode + + + align:start position:0% +system and moreover the mode +shapes the reason this + + align:start position:0% + + + + align:start position:0% + +works be is because the mode shape + + align:start position:0% + + + + align:start position:0% + +are orthogonal to one + + align:start position:0% + + + + align:start position:0% + +another now you know that if you take uh + + align:start position:0% +another now you know that if you take uh + + + align:start position:0% +another now you know that if you take uh +two sine waves like that string and you + + align:start position:0% +two sine waves like that string and you + + + align:start position:0% +two sine waves like that string and you +and you take s first mode sign pix over + + align:start position:0% +and you take s first mode sign pix over + + + align:start position:0% +and you take s first mode sign pix over +L and second mode say sign 2 pix over L + + align:start position:0% +L and second mode say sign 2 pix over L + + + align:start position:0% +L and second mode say sign 2 pix over L +and you multiply them together and + + align:start position:0% +and you multiply them together and + + + align:start position:0% +and you multiply them together and +integrate from 0 to L what do you + + align:start position:0% + + + + align:start position:0% + +get you always get zero if there if the + + align:start position:0% +get you always get zero if there if the + + + align:start position:0% +get you always get zero if there if the +two signs are if they're full + + align:start position:0% +two signs are if they're full + + + align:start position:0% +two signs are if they're full +wavelengths they go to nodes at the end + + align:start position:0% +wavelengths they go to nodes at the end + + + align:start position:0% +wavelengths they go to nodes at the end +you will always get zero if the + + align:start position:0% +you will always get zero if the + + + align:start position:0% +you will always get zero if the +wavelengths are + + align:start position:0% +wavelengths are + + + align:start position:0% +wavelengths are +different + + align:start position:0% +different + + + align:start position:0% +different +always right that's a statement of + + align:start position:0% +always right that's a statement of + + + align:start position:0% +always right that's a statement of +orthogonality of S + + align:start position:0% +orthogonality of S + + + align:start position:0% +orthogonality of S +functions right same thing is true of + + align:start position:0% +functions right same thing is true of + + + align:start position:0% +functions right same thing is true of +these simple vectors they're orthogonal + + align:start position:0% +these simple vectors they're orthogonal + + + align:start position:0% +these simple vectors they're orthogonal +to one another such that if you do this + + align:start position:0% +to one another such that if you do this + + + align:start position:0% +to one another such that if you do this +multiplication you transpose mu you only + + align:start position:0% +multiplication you transpose mu you only + + + align:start position:0% +multiplication you transpose mu you only +get contributions when you are using + + align:start position:0% +get contributions when you are using + + + align:start position:0% +get contributions when you are using +mode R transpose M mode R you only get a + + align:start position:0% +mode R transpose M mode R you only get a + + + align:start position:0% +mode R transpose M mode R you only get a +contribution from each of those that + + align:start position:0% +contribution from each of those that + + + align:start position:0% +contribution from each of those that +gives you the diagonals same is true + + align:start position:0% +gives you the diagonals same is true + + + align:start position:0% +gives you the diagonals same is true +when you do U transpose KU because of + + align:start position:0% +when you do U transpose KU because of + + + align:start position:0% +when you do U transpose KU because of +orthogonality you only get a diagonal + + align:start position:0% +orthogonality you only get a diagonal + + + align:start position:0% +orthogonality you only get a diagonal +matrix at the end and under the right + + align:start position:0% +matrix at the end and under the right + + + align:start position:0% +matrix at the end and under the right +conditions you transpose CU gives you a + + align:start position:0% +conditions you transpose CU gives you a + + + align:start position:0% +conditions you transpose CU gives you a +diagonal + + align:start position:0% +diagonal + + + align:start position:0% +diagonal +matrix so what's that good for + + align:start position:0% + + + + align:start position:0% + +well here was the set of equations that + + align:start position:0% +well here was the set of equations that + + + align:start position:0% +well here was the set of equations that +we get when we make that substitution + + align:start position:0% +we get when we make that substitution + + + align:start position:0% +we get when we make that substitution +this is going to give + + align:start position:0% + + + + align:start position:0% + +us a + + align:start position:0% +us a + + + align:start position:0% +us a +diagonal Mass Matrix time Q dot plus + + align:start position:0% +diagonal Mass Matrix time Q dot plus + + + align:start position:0% +diagonal Mass Matrix time Q dot plus +when conditions are right a diagonal + + align:start position:0% +when conditions are right a diagonal + + + align:start position:0% +when conditions are right a diagonal +damping Matrix time Q dot plus a + + align:start position:0% +damping Matrix time Q dot plus a + + + align:start position:0% +damping Matrix time Q dot plus a +diagonal stiffness Matrix time + + align:start position:0% + + + + align:start position:0% + +Q + + align:start position:0% +Q + + + align:start position:0% +Q +equals U transpose + + align:start position:0% +equals U transpose + + + align:start position:0% +equals U transpose +F which it's a vector times a matrix + + align:start position:0% +F which it's a vector times a matrix + + + align:start position:0% +F which it's a vector times a matrix +gives you back a vector which we call + + align:start position:0% +gives you back a vector which we call + + + align:start position:0% +gives you back a vector which we call +capital Q it's a function of time and + + align:start position:0% +capital Q it's a function of time and + + + align:start position:0% +capital Q it's a function of time and +this is called the modal Force + + align:start position:0% + + + + align:start position:0% + +but if you look carefully at these if I + + align:start position:0% +but if you look carefully at these if I + + + align:start position:0% +but if you look carefully at these if I +pick the arth one mode mode R out of + + align:start position:0% +pick the arth one mode mode R out of + + + align:start position:0% +pick the arth one mode mode R out of +this whole + + align:start position:0% +this whole + + + align:start position:0% +this whole +thing so + + align:start position:0% +thing so + + + align:start position:0% +thing so +the or I if I just pick any mode out of + + align:start position:0% +the or I if I just pick any mode out of + + + align:start position:0% +the or I if I just pick any mode out of +this any part of this vector and + + align:start position:0% +this any part of this vector and + + + align:start position:0% +this any part of this vector and +complete this multiplication I will find + + align:start position:0% +complete this multiplication I will find + + + align:start position:0% +complete this multiplication I will find +that I get an m r which is the rth entry + + align:start position:0% +that I get an m r which is the rth entry + + + align:start position:0% +that I get an m r which is the rth entry +here and now to to I'm going to refer to + + align:start position:0% +here and now to to I'm going to refer to + + + align:start position:0% +here and now to to I'm going to refer to +these as the modal masses and I'll write + + align:start position:0% +these as the modal masses and I'll write + + + align:start position:0% +these as the modal masses and I'll write +them with capitals and I'll give it + + align:start position:0% +them with capitals and I'll give it + + + align:start position:0% +them with capitals and I'll give it +subscript to tell you what the mode is + + align:start position:0% +subscript to tell you what the mode is + + + align:start position:0% +subscript to tell you what the mode is +this is a number this is the modal mass + + align:start position:0% +this is a number this is the modal mass + + + align:start position:0% +this is a number this is the modal mass +for mode R this gives me an equation + + align:start position:0% +for mode R this gives me an equation + + + align:start position:0% +for mode R this gives me an equation +that looks like m r QR dble dot plus CR + + align:start position:0% +that looks like m r QR dble dot plus CR + + + align:start position:0% +that looks like m r QR dble dot plus CR +QR dot plus KR QR equals QR of T and + + align:start position:0% +QR dot plus KR QR equals QR of T and + + + align:start position:0% +QR dot plus KR QR equals QR of T and +what does that remind you + + align:start position:0% +what does that remind you + + + align:start position:0% +what does that remind you +of that we've done a lot of work + + align:start position:0% +of that we've done a lot of work + + + align:start position:0% +of that we've done a lot of work +with what how many degree of Freedom + + align:start position:0% +with what how many degree of Freedom + + + align:start position:0% +with what how many degree of Freedom +system it looks that's the equation of + + align:start position:0% +system it looks that's the equation of + + + align:start position:0% +system it looks that's the equation of +motion the generic equation of motion of + + align:start position:0% +motion the generic equation of motion of + + + align:start position:0% +motion the generic equation of motion of +a single degree Freedom oscillator and + + align:start position:0% +a single degree Freedom oscillator and + + + align:start position:0% +a single degree Freedom oscillator and +you know how to calculate the response + + align:start position:0% +you know how to calculate the response + + + align:start position:0% +you know how to calculate the response +to initial conditions for that you know + + align:start position:0% +to initial conditions for that you know + + + align:start position:0% +to initial conditions for that you know +how to calculate the steady state + + align:start position:0% +how to calculate the steady state + + + align:start position:0% +how to calculate the steady state +response for that when you have harmonic + + align:start position:0% +response for that when you have harmonic + + + align:start position:0% +response for that when you have harmonic +input right when I said at the beginning + + align:start position:0% +input right when I said at the beginning + + + align:start position:0% +input right when I said at the beginning +of the beginning of the discussion about + + align:start position:0% +of the beginning of the discussion about + + + align:start position:0% +of the beginning of the discussion about +vibration is it's really important to + + align:start position:0% +vibration is it's really important to + + + align:start position:0% +vibration is it's really important to +understand the single degree of Freedom + + align:start position:0% +understand the single degree of Freedom + + + align:start position:0% +understand the single degree of Freedom +oscillator because it gives you it'll + + align:start position:0% +oscillator because it gives you it'll + + + align:start position:0% +oscillator because it gives you it'll +give you insight as to the behavior of + + align:start position:0% +give you insight as to the behavior of + + + align:start position:0% +give you insight as to the behavior of +complicated multiple degree Freedom + + align:start position:0% +complicated multiple degree Freedom + + + align:start position:0% +complicated multiple degree Freedom +systems and here's here's the the proof + + align:start position:0% +systems and here's here's the the proof + + + align:start position:0% +systems and here's here's the the proof +of + + align:start position:0% +of + + + align:start position:0% +of +this + + align:start position:0% +this + + + align:start position:0% +this +any this is now n uncoupled single + + align:start position:0% +any this is now n uncoupled single + + + align:start position:0% +any this is now n uncoupled single +degree of Freedom + + align:start position:0% +degree of Freedom + + + align:start position:0% +degree of Freedom +systems this is n + + align:start position:0% + + + + align:start position:0% + +independent single one degree of + + align:start position:0% +independent single one degree of + + + align:start position:0% +independent single one degree of +Freedom systems + + align:start position:0% + + + + align:start position:0% + +which you can solve one at a + + align:start position:0% + + + + align:start position:0% + +time now lots of + + align:start position:0% + + + + align:start position:0% + +times a vibrating system a complicated + + align:start position:0% +times a vibrating system a complicated + + + align:start position:0% +times a vibrating system a complicated +one might be this + + align:start position:0% +one might be this + + + align:start position:0% +one might be this +thing if I hit this it's vibrating and + + align:start position:0% +thing if I hit this it's vibrating and + + + align:start position:0% +thing if I hit this it's vibrating and +actually it's pretty much vibrating at a + + align:start position:0% +actually it's pretty much vibrating at a + + + align:start position:0% +actually it's pretty much vibrating at a +single + + align:start position:0% + + + + align:start position:0% + +frequency and are there any once I've + + align:start position:0% +frequency and are there any once I've + + + align:start position:0% +frequency and are there any once I've +hit it are there any external forces + + align:start position:0% +hit it are there any external forces + + + align:start position:0% +hit it are there any external forces +driving it so what kind of response are + + align:start position:0% +driving it so what kind of response are + + + align:start position:0% +driving it so what kind of response are +you + + align:start position:0% + + + + align:start position:0% + +seeing response + + align:start position:0% +seeing response + + + align:start position:0% +seeing response +to initial conditions right now in + + align:start position:0% +to initial conditions right now in + + + align:start position:0% +to initial conditions right now in +general each one of the natural modes of + + align:start position:0% +general each one of the natural modes of + + + align:start position:0% +general each one of the natural modes of +a system has a different natural + + align:start position:0% +a system has a different natural + + + align:start position:0% +a system has a different natural +frequency right + + align:start position:0% +frequency right + + + align:start position:0% +frequency right +so if I hit this thing and I look at it + + align:start position:0% +so if I hit this thing and I look at it + + + align:start position:0% +so if I hit this thing and I look at it +you know it really I can just see it + + align:start position:0% +you know it really I can just see it + + + align:start position:0% +you know it really I can just see it +wiggling back and forth and basically at + + align:start position:0% +wiggling back and forth and basically at + + + align:start position:0% +wiggling back and forth and basically at +one + + align:start position:0% +one + + + align:start position:0% +one +frequency so if you wanted to come up + + align:start position:0% +frequency so if you wanted to come up + + + align:start position:0% +frequency so if you wanted to come up +with a simple model of this system how + + align:start position:0% +with a simple model of this system how + + + align:start position:0% +with a simple model of this system how +many natural modes do you think you'd + + align:start position:0% +many natural modes do you think you'd + + + align:start position:0% +many natural modes do you think you'd +have to include to describe the motion + + align:start position:0% +have to include to describe the motion + + + align:start position:0% +have to include to describe the motion +of this + + align:start position:0% +of this + + + align:start position:0% +of this +system one now is that a lot easier than + + align:start position:0% +system one now is that a lot easier than + + + align:start position:0% +system one now is that a lot easier than +having to do the full General equation + + align:start position:0% +having to do the full General equation + + + align:start position:0% +having to do the full General equation +of motion for all the possible modes + + align:start position:0% +of motion for all the possible modes + + + align:start position:0% +of motion for all the possible modes +that this thing has and D out a lot + + align:start position:0% +that this thing has and D out a lot + + + align:start position:0% +that this thing has and D out a lot +right you have to deal with with + + align:start position:0% +right you have to deal with with + + + align:start position:0% +right you have to deal with with +equation of motion of a single degree + + align:start position:0% +equation of motion of a single degree + + + align:start position:0% +equation of motion of a single degree +Freedom system to describe this and + + align:start position:0% +Freedom system to describe this and + + + align:start position:0% +Freedom system to describe this and +that's the real point you know they + + align:start position:0% +that's the real point you know they + + + align:start position:0% +that's the real point you know they +built the Hancock building across the + + align:start position:0% +built the Hancock building across the + + + align:start position:0% +built the Hancock building across the +river 35 years ago was losing Windows + + align:start position:0% +river 35 years ago was losing Windows + + + align:start position:0% +river 35 years ago was losing Windows +like crazy it was brand new building and + + align:start position:0% +like crazy it was brand new building and + + + align:start position:0% +like crazy it was brand new building and +the windows when the wind would get + + align:start position:0% +the windows when the wind would get + + + align:start position:0% +the windows when the wind would get +about 40 mes hour the window started + + align:start position:0% +about 40 mes hour the window started + + + align:start position:0% +about 40 mes hour the window started +falling out 60 stories high 60 61 + + align:start position:0% +falling out 60 stories high 60 61 + + + align:start position:0% +falling out 60 stories high 60 61 +stories high and the wind was blowing + + align:start position:0% +stories high and the wind was blowing + + + align:start position:0% +stories high and the wind was blowing +where do you suppos the window do fall + + align:start position:0% +where do you suppos the window do fall + + + align:start position:0% +where do you suppos the window do fall +out what part of the building + + align:start position:0% +out what part of the building + + + align:start position:0% +out what part of the building +huh I mean you'd think the wind wind is + + align:start position:0% +huh I mean you'd think the wind wind is + + + align:start position:0% +huh I mean you'd think the wind wind is +blown it gets stronger as it goes up + + align:start position:0% +blown it gets stronger as it goes up + + + align:start position:0% +blown it gets stronger as it goes up +it's probably blown out the wind is at + + align:start position:0% +it's probably blown out the wind is at + + + align:start position:0% +it's probably blown out the wind is at +the top right but the windows were + + align:start position:0% +the top right but the windows were + + + align:start position:0% +the top right but the windows were +breaking as you you as time went by + + align:start position:0% +breaking as you you as time went by + + + align:start position:0% +breaking as you you as time went by +every time the window would break they + + align:start position:0% +every time the window would break they + + + align:start position:0% +every time the window would break they +would they replace this 5 foot by 9t + + align:start position:0% +would they replace this 5 foot by 9t + + + align:start position:0% +would they replace this 5 foot by 9t +sheet of glass with a piece of plywood + + align:start position:0% +sheet of glass with a piece of plywood + + + align:start position:0% +sheet of glass with a piece of plywood +and so you got this statistical sampling + + align:start position:0% +and so you got this statistical sampling + + + align:start position:0% +and so you got this statistical sampling +after a while of where the breakage was + + align:start position:0% +after a while of where the breakage was + + + align:start position:0% +after a while of where the breakage was +so you had no windows broken at the + + align:start position:0% +so you had no windows broken at the + + + align:start position:0% +so you had no windows broken at the +top and a few as you got further down + + align:start position:0% +top and a few as you got further down + + + align:start position:0% +top and a few as you got further down +and more and lots of them broken out at + + align:start position:0% +and more and lots of them broken out at + + + align:start position:0% +and more and lots of them broken out at +the bottom + + align:start position:0% +the bottom + + + align:start position:0% +the bottom +it turns out that that building was + + align:start position:0% +it turns out that that building was + + + align:start position:0% +it turns out that that building was +vibrating in its both mostly in its + + align:start position:0% +vibrating in its both mostly in its + + + align:start position:0% +vibrating in its both mostly in its +first bending mode it was going back and + + align:start position:0% +first bending mode it was going back and + + + align:start position:0% +first bending mode it was going back and +forth like + + align:start position:0% +forth like + + + align:start position:0% +forth like +this also happened to have a torsional + + align:start position:0% +this also happened to have a torsional + + + align:start position:0% +this also happened to have a torsional +mode this first torsional mode was kind + + align:start position:0% +mode this first torsional mode was kind + + + align:start position:0% +mode this first torsional mode was kind +of twisting around the base like that so + + align:start position:0% +of twisting around the base like that so + + + align:start position:0% +of twisting around the base like that so +in fact this motion the mo when when to + + align:start position:0% +in fact this motion the mo when when to + + + align:start position:0% +in fact this motion the mo when when to +get about 40 miles hour this building + + align:start position:0% +get about 40 miles hour this building + + + align:start position:0% +get about 40 miles hour this building +start rocking and rolling mostly like + + align:start position:0% +start rocking and rolling mostly like + + + align:start position:0% +start rocking and rolling mostly like +this with a little of this thrown in + + align:start position:0% +this with a little of this thrown in + + + align:start position:0% +this with a little of this thrown in +okay and but you can basically model + + align:start position:0% +okay and but you can basically model + + + align:start position:0% +okay and but you can basically model +that complicated building that has + + align:start position:0% +that complicated building that has + + + align:start position:0% +that complicated building that has +millions of possible natural modes in it + + align:start position:0% +millions of possible natural modes in it + + + align:start position:0% +millions of possible natural modes in it +by one or possibly two single degree + + align:start position:0% +by one or possibly two single degree + + + align:start position:0% +by one or possibly two single degree +Freedom + + align:start position:0% +Freedom + + + align:start position:0% +Freedom +oscillators so that's the power modal + + align:start position:0% +oscillators so that's the power modal + + + align:start position:0% +oscillators so that's the power modal +analysis but I think the real power of + + align:start position:0% +analysis but I think the real power of + + + align:start position:0% +analysis but I think the real power of +understanding that you can do this is + + align:start position:0% +understanding that you can do this is + + + align:start position:0% +understanding that you can do this is +that it gives you this immediate insight + + align:start position:0% +that it gives you this immediate insight + + + align:start position:0% +that it gives you this immediate insight +as to what might be going on in + + align:start position:0% +as to what might be going on in + + + align:start position:0% +as to what might be going on in +something so I look at this I don't I + + align:start position:0% +something so I look at this I don't I + + + align:start position:0% +something so I look at this I don't I +don't see a complicated thing that I + + align:start position:0% +don't see a complicated thing that I + + + align:start position:0% +don't see a complicated thing that I +have to model with a big finite element + + align:start position:0% +have to model with a big finite element + + + align:start position:0% +have to model with a big finite element +model I see something that's vibrating + + align:start position:0% +model I see something that's vibrating + + + align:start position:0% +model I see something that's vibrating +at one frequency and I can I know it has + + align:start position:0% +at one frequency and I can I know it has + + + align:start position:0% +at one frequency and I can I know it has +a it'll Decay it'll have damping it'll + + align:start position:0% +a it'll Decay it'll have damping it'll + + + align:start position:0% +a it'll Decay it'll have damping it'll +have a natural natural frequency and I + + align:start position:0% +have a natural natural frequency and I + + + align:start position:0% +have a natural natural frequency and I +to get immediate insight as to Its + + align:start position:0% +to get immediate insight as to Its + + + align:start position:0% +to get immediate insight as to Its +Behavior by knowing this okay and that's + + align:start position:0% +Behavior by knowing this okay and that's + + + align:start position:0% +Behavior by knowing this okay and that's +the real reason why I wanted to show + + align:start position:0% +the real reason why I wanted to show + + + align:start position:0% +the real reason why I wanted to show +this to + + align:start position:0% +this to + + + align:start position:0% +this to +you so today + + align:start position:0% +you so today + + + align:start position:0% +you so today +we I want we'll do um there sort of two + + align:start position:0% +we I want we'll do um there sort of two + + + align:start position:0% +we I want we'll do um there sort of two +things two two directions we can go with + + align:start position:0% +things two two directions we can go with + + + align:start position:0% +things two two directions we can go with +this one is to talk about response to + + align:start position:0% +this one is to talk about response to + + + align:start position:0% +this one is to talk about response to +initial conditions and the other is to + + align:start position:0% +initial conditions and the other is to + + + align:start position:0% +initial conditions and the other is to +talk about the response to force + + align:start position:0% +talk about the response to force + + + align:start position:0% +talk about the response to force +excitation so let's we're going to begin + + align:start position:0% + + + + align:start position:0% + +by doing response to + + align:start position:0% +by doing response to + + + align:start position:0% +by doing response to +I's okay and then we'll move on probably + + align:start position:0% +I's okay and then we'll move on probably + + + align:start position:0% +I's okay and then we'll move on probably +next time and talk about response to + + align:start position:0% +next time and talk about response to + + + align:start position:0% +next time and talk about response to +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +excitations and uh be so be and we're + + align:start position:0% +excitations and uh be so be and we're + + + align:start position:0% +excitations and uh be so be and we're +going to use that as the + + align:start position:0% +going to use that as the + + + align:start position:0% +going to use that as the +example before I go there how uh once we + + align:start position:0% +example before I go there how uh once we + + + align:start position:0% +example before I go there how uh once we +have broken the system down and analyzed + + align:start position:0% +have broken the system down and analyzed + + + align:start position:0% +have broken the system down and analyzed +it this way how do we get back + + align:start position:0% +it this way how do we get back + + + align:start position:0% +it this way how do we get back +to the motion of the system in our + + align:start position:0% +to the motion of the system in our + + + align:start position:0% +to the motion of the system in our +generalized coordinates which are the + + align:start position:0% +generalized coordinates which are the + + + align:start position:0% +generalized coordinates which are the +ones we're comfortable with because I + + align:start position:0% +ones we're comfortable with because I + + + align:start position:0% +ones we're comfortable with because I +don't know how to take where to take a + + align:start position:0% +don't know how to take where to take a + + + align:start position:0% +don't know how to take where to take a +ruler and go + + align:start position:0% +ruler and go + + + align:start position:0% +ruler and go +measure measure this natural + + align:start position:0% +measure measure this natural + + + align:start position:0% +measure measure this natural +coordinate so somehow I have to get back + + align:start position:0% +coordinate so somehow I have to get back + + + align:start position:0% +coordinate so somehow I have to get back +to putting into real physical + + align:start position:0% +to putting into real physical + + + align:start position:0% +to putting into real physical +measurements that I know how that I can + + align:start position:0% +measurements that I know how that I can + + + align:start position:0% +measurements that I know how that I can +relate to well that's easy because it's + + align:start position:0% +relate to well that's easy because it's + + + align:start position:0% +relate to well that's easy because it's +where where did we start with this we + + align:start position:0% +where where did we start with this we + + + align:start position:0% +where where did we start with this we +started by saying this whole thing began + + align:start position:0% +started by saying this whole thing began + + + align:start position:0% +started by saying this whole thing began +right here + + align:start position:0% + + + + align:start position:0% + +and so at the end you we we just come + + align:start position:0% +and so at the end you we we just come + + + align:start position:0% +and so at the end you we we just come +back and say oh well X here our + + align:start position:0% +back and say oh well X here our + + + align:start position:0% +back and say oh well X here our +generalized coordinates is this + + align:start position:0% +generalized coordinates is this + + + align:start position:0% +generalized coordinates is this +summation of the mode + + align:start position:0% +summation of the mode + + + align:start position:0% +summation of the mode +shapes + + align:start position:0% + + + + align:start position:0% + +u i here summed summed over I of q i + + align:start position:0% +u i here summed summed over I of q i + + + align:start position:0% +u i here summed summed over I of q i +of + + align:start position:0% +of + + + align:start position:0% +of +T now the reason I wrote it here is a + + align:start position:0% +T now the reason I wrote it here is a + + + align:start position:0% +T now the reason I wrote it here is a +summation is to to you is to remind you + + align:start position:0% +summation is to to you is to remind you + + + align:start position:0% +summation is to to you is to remind you +that you do + + align:start position:0% + + + + align:start position:0% + +this that's the beauty of this thing is + + align:start position:0% +this that's the beauty of this thing is + + + align:start position:0% +this that's the beauty of this thing is +you only have to do it over the modes + + align:start position:0% +you only have to do it over the modes + + + align:start position:0% +you only have to do it over the modes +that matter or so if you've decided to + + align:start position:0% +that matter or so if you've decided to + + + align:start position:0% +that matter or so if you've decided to +approximate the motion of this complic + + align:start position:0% +approximate the motion of this complic + + + align:start position:0% +approximate the motion of this complic +comp at system by just a couple of modal + + align:start position:0% +comp at system by just a couple of modal + + + align:start position:0% +comp at system by just a couple of modal +contributions because you know they're + + align:start position:0% +contributions because you know they're + + + align:start position:0% +contributions because you know they're +the important ones this this is a pretty + + align:start position:0% +the important ones this this is a pretty + + + align:start position:0% +the important ones this this is a pretty +short summation this is how you get back + + align:start position:0% +short summation this is how you get back + + + align:start position:0% +short summation this is how you get back +to your original modal coordinates is + + align:start position:0% +to your original modal coordinates is + + + align:start position:0% +to your original modal coordinates is +take the modal + + align:start position:0% +take the modal + + + align:start position:0% +take the modal +amplitude multiply it by the mode + + align:start position:0% +amplitude multiply it by the mode + + + align:start position:0% +amplitude multiply it by the mode +shape and when you do that it says you + + align:start position:0% +shape and when you do that it says you + + + align:start position:0% +shape and when you do that it says you +know this turns out to be say some a sin + + align:start position:0% +know this turns out to be say some a sin + + + align:start position:0% +know this turns out to be say some a sin +Omega T when you multiply it by the mode + + align:start position:0% +Omega T when you multiply it by the mode + + + align:start position:0% +Omega T when you multiply it by the mode +shape it basically tells you how much + + align:start position:0% +shape it basically tells you how much + + + align:start position:0% +shape it basically tells you how much +each generalized coordinate gets of the + + align:start position:0% +each generalized coordinate gets of the + + + align:start position:0% +each generalized coordinate gets of the +motion the mode shape distributes the + + align:start position:0% +motion the mode shape distributes the + + + align:start position:0% +motion the mode shape distributes the +answer out proportionally in the correct + + align:start position:0% +answer out proportionally in the correct + + + align:start position:0% +answer out proportionally in the correct +amount so this is how you get back to + + align:start position:0% +amount so this is how you get back to + + + align:start position:0% +amount so this is how you get back to +the iginal so let's think about that + + align:start position:0% + + + + align:start position:0% + +system and we'll do an initial + + align:start position:0% +system and we'll do an initial + + + align:start position:0% +system and we'll do an initial +conditions kind of problem so I think + + align:start position:0% +conditions kind of problem so I think + + + align:start position:0% +conditions kind of problem so I think +Professor goser you I think in class you + + align:start position:0% +Professor goser you I think in class you + + + align:start position:0% +Professor goser you I think in class you +sort of figured out what the approximate + + align:start position:0% +sort of figured out what the approximate + + + align:start position:0% +sort of figured out what the approximate +K's and M's and things were for that + + align:start position:0% +K's and M's and things were for that + + + align:start position:0% +K's and M's and things were for that +system so I actually took it apart + + align:start position:0% +system so I actually took it apart + + + align:start position:0% +system so I actually took it apart +weighed it measured some natural free + + align:start position:0% +weighed it measured some natural free + + + align:start position:0% +weighed it measured some natural free +frequencies and have come up + + align:start position:0% +frequencies and have come up + + + align:start position:0% +frequencies and have come up +with a pretty + + align:start position:0% +with a pretty + + + align:start position:0% +with a pretty +good + + align:start position:0% +good + + + align:start position:0% +good +model I release pretty good set of + + align:start position:0% +model I release pretty good set of + + + align:start position:0% +model I release pretty good set of +numbers characterizing this two degree + + align:start position:0% +numbers characterizing this two degree + + + align:start position:0% +numbers characterizing this two degree +Freedom + + align:start position:0% + + + + align:start position:0% + +system so + + align:start position:0% +system so + + + align:start position:0% +system so +C1 K1 M1 K2 + + align:start position:0% + + + + align:start position:0% + +C2 + + align:start position:0% +C2 + + + align:start position:0% +C2 +X1 X2 so these are my generalized + + align:start position:0% +X1 X2 so these are my generalized + + + align:start position:0% +X1 X2 so these are my generalized +coordinates measured probably from what + + align:start position:0% + + + + align:start position:0% + +position static equilibrium right so I + + align:start position:0% +position static equilibrium right so I + + + align:start position:0% +position static equilibrium right so I +don't have to mess with gravity in + + align:start position:0% +don't have to mess with gravity in + + + align:start position:0% +don't have to mess with gravity in +this measured from static equilibrium + + align:start position:0% +this measured from static equilibrium + + + align:start position:0% +this measured from static equilibrium +and to try to help keep + + align:start position:0% +and to try to help keep + + + align:start position:0% +and to try to help keep +things understandable track I've write I + + align:start position:0% +things understandable track I've write I + + + align:start position:0% +things understandable track I've write I +tried to write the parameters of the + + align:start position:0% +tried to write the parameters of the + + + align:start position:0% +tried to write the parameters of the +system as lowercase k1s k2s k3s because + + align:start position:0% +system as lowercase k1s k2s k3s because + + + align:start position:0% +system as lowercase k1s k2s k3s because +I want to write modal stiffness for mode + + align:start position:0% +I want to write modal stiffness for mode + + + align:start position:0% +I want to write modal stiffness for mode +one is a capital K1 so I'll try to be + + align:start position:0% +one is a capital K1 so I'll try to be + + + align:start position:0% +one is a capital K1 so I'll try to be +consistent about that and notice where I + + align:start position:0% +consistent about that and notice where I + + + align:start position:0% +consistent about that and notice where I +put the dampers in the + + align:start position:0% +put the dampers in the + + + align:start position:0% +put the dampers in the +system that's because most of the + + align:start position:0% +system that's because most of the + + + align:start position:0% +system that's because most of the +damping in this thing comes from the + + align:start position:0% +damping in this thing comes from the + + + align:start position:0% +damping in this thing comes from the +upper Mass rubs against the stationary + + align:start position:0% +upper Mass rubs against the stationary + + + align:start position:0% +upper Mass rubs against the stationary +object and the lower which is the the + + align:start position:0% +object and the lower which is the the + + + align:start position:0% +object and the lower which is the the +bar here the lower Mass rubs against the + + align:start position:0% +bar here the lower Mass rubs against the + + + align:start position:0% +bar here the lower Mass rubs against the +station area object so it's as if I'm + + align:start position:0% +station area object so it's as if I'm + + + align:start position:0% +station area object so it's as if I'm +going to model that as a dash putt + + align:start position:0% +going to model that as a dash putt + + + align:start position:0% +going to model that as a dash putt +between each mass and the fixed + + align:start position:0% +between each mass and the fixed + + + align:start position:0% +between each mass and the fixed +reference frame because the the bar + + align:start position:0% +reference frame because the the bar + + + align:start position:0% +reference frame because the the bar +doesn't move so it's an approximate + + align:start position:0% +doesn't move so it's an approximate + + + align:start position:0% +doesn't move so it's an approximate +model of the damping and so if we do our + + align:start position:0% +model of the damping and so if we do our + + + align:start position:0% +model of the damping and so if we do our +sum of + + align:start position:0% +sum of + + + align:start position:0% +sum of +forces on each of these masses just do + + align:start position:0% +forces on each of these masses just do + + + align:start position:0% +forces on each of these masses just do +Newton's on the mass uh we can come up + + align:start position:0% +Newton's on the mass uh we can come up + + + align:start position:0% +Newton's on the mass uh we can come up +with our two equations of motion we get + + align:start position:0% +with our two equations of motion we get + + + align:start position:0% +with our two equations of motion we get +two equations of + + align:start position:0% + + + + align:start position:0% + +motion and let's see + + align:start position:0% + + + + align:start position:0% + +think I give you some information here + + align:start position:0% +think I give you some information here + + + align:start position:0% +think I give you some information here +first M1 + + align:start position:0% + + + + align:start position:0% + +so those and I really don't know the + + align:start position:0% +so those and I really don't know the + + + align:start position:0% +so those and I really don't know the +damping but we can get that by counting + + align:start position:0% +damping but we can get that by counting + + + align:start position:0% +damping but we can get that by counting +how many cycles it takes to Decay and so + + align:start position:0% +how many cycles it takes to Decay and so + + + align:start position:0% +how many cycles it takes to Decay and so +forth so that's basically what I go come + + align:start position:0% +forth so that's basically what I go come + + + align:start position:0% +forth so that's basically what I go come +into this problem + + align:start position:0% + + + + align:start position:0% + +knowing and I'm going to write my + + align:start position:0% +knowing and I'm going to write my + + + align:start position:0% +knowing and I'm going to write my +equations of motion as in Matrix form so + + align:start position:0% +equations of motion as in Matrix form so + + + align:start position:0% +equations of motion as in Matrix form so +it's going to end up looking like + + align:start position:0% + + + + align:start position:0% + +M1 now notice the damping in this one + + align:start position:0% +M1 now notice the damping in this one + + + align:start position:0% +M1 now notice the damping in this one +the damping force is only proportion + + align:start position:0% +the damping force is only proportion + + + align:start position:0% +the damping force is only proportion +it'll be C1 X1 dot had nothing doesn't + + align:start position:0% +it'll be C1 X1 dot had nothing doesn't + + + align:start position:0% +it'll be C1 X1 dot had nothing doesn't +involve the motion of the other object + + align:start position:0% +involve the motion of the other object + + + align:start position:0% +involve the motion of the other object +and this one the damping Force only + + align:start position:0% +and this one the damping Force only + + + align:start position:0% +and this one the damping Force only +involves the second motion so this H + + align:start position:0% +involves the second motion so this H + + + align:start position:0% +involves the second motion so this H +this one happens to look like a + + align:start position:0% +this one happens to look like a + + + align:start position:0% +this one happens to look like a +C1 0 + + align:start position:0% + + + + align:start position:0% + +C2 and the stiffness + + align:start position:0% +C2 and the stiffness + + + align:start position:0% +C2 and the stiffness +Matrix well it's K1 + + + align:start position:0% +Matrix well it's K1 + + + + align:start position:0% +Matrix well it's K1 + +K2 - + + align:start position:0% +K2 - + + + align:start position:0% +K2 - +K2 Min - + + align:start position:0% +K2 Min - + + + align:start position:0% +K2 Min - +K2 and K + + align:start position:0% + + + + align:start position:0% + +K2 X1 + + align:start position:0% +K2 X1 + + + align:start position:0% +K2 X1 +X2 and + + align:start position:0% +X2 and + + + align:start position:0% +X2 and +for no external forces this starts off + + align:start position:0% +for no external forces this starts off + + + align:start position:0% +for no external forces this starts off +this one is a has no exter and nothing + + align:start position:0% +this one is a has no exter and nothing + + + align:start position:0% +this one is a has no exter and nothing +on the right hand side equal to zero so + + align:start position:0% +on the right hand side equal to zero so + + + align:start position:0% +on the right hand side equal to zero so +those are my equations of motion and you + + align:start position:0% +those are my equations of motion and you + + + align:start position:0% +those are my equations of motion and you +know if you multiply these out you get + + align:start position:0% +know if you multiply these out you get + + + align:start position:0% +know if you multiply these out you get +two equations and each one would be is a + + align:start position:0% +two equations and each one would be is a + + + align:start position:0% +two equations and each one would be is a +result that you get by applying Newton's + + align:start position:0% +result that you get by applying Newton's + + + align:start position:0% +result that you get by applying Newton's +law to mass one and Newton's law to mass + + align:start position:0% +law to mass one and Newton's law to mass + + + align:start position:0% +law to mass one and Newton's law to mass +two but you we've done that enough times + + align:start position:0% +two but you we've done that enough times + + + align:start position:0% +two but you we've done that enough times +I'm not going to go through that that + + align:start position:0% +I'm not going to go through that that + + + align:start position:0% +I'm not going to go through that that +part of + + align:start position:0% + + + + align:start position:0% + +it okay + + align:start position:0% + + + + align:start position:0% + +and putting in real + + align:start position:0% + + + + align:start position:0% + +numbers that's our Mass + + align:start position:0% + + + + align:start position:0% + +Matrix I don't know + + align:start position:0% +Matrix I don't know + + + align:start position:0% +Matrix I don't know +this my stiffness Matrix + + align:start position:0% + + + + align:start position:0% + +so this is my K Matrix + + align:start position:0% +so this is my K Matrix + + + align:start position:0% +so this is my K Matrix +here and stiffness matrices they're + + align:start position:0% +here and stiffness matrices they're + + + align:start position:0% +here and stiffness matrices they're +always + + align:start position:0% +always + + + align:start position:0% +always +symmetric damping that although this one + + align:start position:0% +symmetric damping that although this one + + + align:start position:0% +symmetric damping that although this one +happen to be diagonal you'll find the + + align:start position:0% +happen to be diagonal you'll find the + + + align:start position:0% +happen to be diagonal you'll find the +mass matrices and even the damping + + align:start position:0% +mass matrices and even the damping + + + align:start position:0% +mass matrices and even the damping +matrices for our linear systems are + + align:start position:0% +matrices for our linear systems are + + + align:start position:0% +matrices for our linear systems are +symmetric so here's my stiffest Matrix + + align:start position:0% +symmetric so here's my stiffest Matrix + + + align:start position:0% +symmetric so here's my stiffest Matrix +here's my mass + + align:start position:0% +here's my mass + + + align:start position:0% +here's my mass +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +okay so now I want to do and also in + + align:start position:0% +okay so now I want to do and also in + + + align:start position:0% +okay so now I want to do and also in +this case here's my damping Matrix but I + + align:start position:0% +this case here's my damping Matrix but I + + + align:start position:0% +this case here's my damping Matrix but I +leave that because it's the one that's a + + align:start position:0% +leave that because it's the one that's a + + + align:start position:0% +leave that because it's the one that's a +little bit + + align:start position:0% +little bit + + + align:start position:0% +little bit +Troublesome so what do I need to do to + + align:start position:0% +Troublesome so what do I need to do to + + + align:start position:0% +Troublesome so what do I need to do to +this to uh carry out my modal analysis + + align:start position:0% +this to uh carry out my modal analysis + + + align:start position:0% +this to uh carry out my modal analysis +so I need + + align:start position:0% +so I need + + + align:start position:0% +so I need +to go find the results of computing U + + align:start position:0% +to go find the results of computing U + + + align:start position:0% +to go find the results of computing U +transpose M and u u and U transpose + + align:start position:0% +transpose M and u u and U transpose + + + align:start position:0% +transpose M and u u and U transpose +KU and let's see what we + + align:start position:0% + + + + align:start position:0% + +get so we need to know a couple of + + align:start position:0% +get so we need to know a couple of + + + align:start position:0% +get so we need to know a couple of +things about this + + align:start position:0% + + + + align:start position:0% + +system we need to know natural + + align:start position:0% +system we need to know natural + + + align:start position:0% +system we need to know natural +frequencies and mode shapes so if we + + align:start position:0% +frequencies and mode shapes so if we + + + align:start position:0% +frequencies and mode shapes so if we +have this Mass Matrix and we have the + + align:start position:0% +have this Mass Matrix and we have the + + + align:start position:0% +have this Mass Matrix and we have the +stiffness Matrix then we know we can + + align:start position:0% +stiffness Matrix then we know we can + + + align:start position:0% +stiffness Matrix then we know we can +cast this we want the + + align:start position:0% + + + + align:start position:0% + +undamped natural + + align:start position:0% +undamped natural + + + align:start position:0% +undamped natural +frequencies and our mode shapes + + align:start position:0% + + + + align:start position:0% + +and we know that we can + + align:start position:0% +and we know that we can + + + align:start position:0% +and we know that we can +transform the equation we the equations + + align:start position:0% +transform the equation we the equations + + + align:start position:0% +transform the equation we the equations +of motion into an algebraic problem or + + align:start position:0% +of motion into an algebraic problem or + + + align:start position:0% +of motion into an algebraic problem or +we solve for the natural frequencies and + + align:start position:0% +we solve for the natural frequencies and + + + align:start position:0% +we solve for the natural frequencies and +mode shapes so we have uh just to kind + + align:start position:0% +mode shapes so we have uh just to kind + + + align:start position:0% +mode shapes so we have uh just to kind +of remind you really quickly of that + + align:start position:0% +of remind you really quickly of that + + + align:start position:0% +of remind you really quickly of that +remember our equations look like this + + align:start position:0% + + + + align:start position:0% + +undamped and you assume that X is some + + align:start position:0% +undamped and you assume that X is some + + + align:start position:0% +undamped and you assume that X is some +form u in fact e to the the I Omega + + align:start position:0% +form u in fact e to the the I Omega + + + align:start position:0% +form u in fact e to the the I Omega +T you plug it in you get minus Omega 2 m + + align:start position:0% +T you plug it in you get minus Omega 2 m + + + align:start position:0% +T you plug it in you get minus Omega 2 m ++ + + align:start position:0% + + + + align:start position:0% + +k u e to the I Omega T equals + + align:start position:0% +k u e to the I Omega T equals + + + align:start position:0% +k u e to the I Omega T equals +z and this now is your algebraic problem + + align:start position:0% +z and this now is your algebraic problem + + + align:start position:0% +z and this now is your algebraic problem +either this unknown set of amplitudes is + + align:start position:0% +either this unknown set of amplitudes is + + + align:start position:0% +either this unknown set of amplitudes is +zero what these going to turn out to be + + align:start position:0% +zero what these going to turn out to be + + + align:start position:0% +zero what these going to turn out to be +the mod shapes and they're not generally + + align:start position:0% +the mod shapes and they're not generally + + + align:start position:0% +the mod shapes and they're not generally +zero so that means this has to be zero + + align:start position:0% +zero so that means this has to be zero + + + align:start position:0% +zero so that means this has to be zero +that means we know the determinant of + + align:start position:0% +that means we know the determinant of + + + align:start position:0% +that means we know the determinant of +this + + align:start position:0% + + + + align:start position:0% + +Matrix and that'll give you the n in + + align:start position:0% +Matrix and that'll give you the n in + + + align:start position:0% +Matrix and that'll give you the n in +this case the two natural frequencies + + align:start position:0% +this case the two natural frequencies + + + align:start position:0% +this case the two natural frequencies +this gives you the Omega n's of the + + align:start position:0% +this gives you the Omega n's of the + + + align:start position:0% +this gives you the Omega n's of the +system Omega n squares is what you solve + + align:start position:0% +system Omega n squares is what you solve + + + align:start position:0% +system Omega n squares is what you solve +for okay and then you go back and you + + align:start position:0% +for okay and then you go back and you + + + align:start position:0% +for okay and then you go back and you +get the + + align:start position:0% +get the + + + align:start position:0% +get the +um the mode shapes out of it and but + + align:start position:0% +um the mode shapes out of it and but + + + align:start position:0% +um the mode shapes out of it and but +this you can do on the computer too you + + align:start position:0% +this you can do on the computer too you + + + align:start position:0% +this you can do on the computer too you +can either crank out the qu this gives + + align:start position:0% +can either crank out the qu this gives + + + align:start position:0% +can either crank out the qu this gives +you for a two degree Freedom system this + + align:start position:0% +you for a two degree Freedom system this + + + align:start position:0% +you for a two degree Freedom system this +gives you a quadratic you know Mega + + align:start position:0% +gives you a quadratic you know Mega + + + align:start position:0% +gives you a quadratic you know Mega +squar you solve it you plug it back in + + align:start position:0% +squar you solve it you plug it back in + + + align:start position:0% +squar you solve it you plug it back in +and get the mode shapes I'm not going to + + align:start position:0% +and get the mode shapes I'm not going to + + + align:start position:0% +and get the mode shapes I'm not going to +take the time to do that today because I + + align:start position:0% +take the time to do that today because I + + + align:start position:0% +take the time to do that today because I +want to do emphasize the modal analysis + + align:start position:0% +want to do emphasize the modal analysis + + + align:start position:0% +want to do emphasize the modal analysis +part so I'll give you the + + align:start position:0% + + + + align:start position:0% + +answers where are we here + + align:start position:0% + + + + align:start position:0% + +so you get Omega 1 it's + + align:start position:0% +so you get Omega 1 it's + + + align:start position:0% +so you get Omega 1 it's +5 65 4 6 and I seem to be keeping a lot + + align:start position:0% +5 65 4 6 and I seem to be keeping a lot + + + align:start position:0% +5 65 4 6 and I seem to be keeping a lot +of lot of significant digits and there's + + align:start position:0% +of lot of significant digits and there's + + + align:start position:0% +of lot of significant digits and there's +a reason for + + align:start position:0% + + + + align:start position:0% + +that one of the reason you need in both + + align:start position:0% +that one of the reason you need in both + + + align:start position:0% +that one of the reason you need in both +mode shapes and natural frequencies you + + align:start position:0% +mode shapes and natural frequencies you + + + align:start position:0% +mode shapes and natural frequencies you +need to carry a lot of signal + + align:start position:0% +need to carry a lot of signal + + + align:start position:0% +need to carry a lot of signal +significant digits or modal analysis + + align:start position:0% +significant digits or modal analysis + + + align:start position:0% +significant digits or modal analysis +doesn't work or at least you don't get + + align:start position:0% +doesn't work or at least you don't get + + + align:start position:0% +doesn't work or at least you don't get +the clean results you expect if you're + + align:start position:0% +the clean results you expect if you're + + + align:start position:0% +the clean results you expect if you're +sloppy about the number of significant + + align:start position:0% +sloppy about the number of significant + + + align:start position:0% +sloppy about the number of significant +digits and you compute youu transpose mu + + align:start position:0% +digits and you compute youu transpose mu + + + align:start position:0% +digits and you compute youu transpose mu +the off diagonal terms won't quite go to + + align:start position:0% +the off diagonal terms won't quite go to + + + align:start position:0% +the off diagonal terms won't quite go to +zero and it's just because you're not + + align:start position:0% +zero and it's just because you're not + + + align:start position:0% +zero and it's just because you're not +carrying enough + + align:start position:0% +carrying enough + + + align:start position:0% +carrying enough +Precision okay now that's the two uh + + align:start position:0% +Precision okay now that's the two uh + + + align:start position:0% +Precision okay now that's the two uh +natural frequencies and now the U Matrix + + align:start position:0% +natural frequencies and now the U Matrix + + + align:start position:0% +natural frequencies and now the U Matrix +the mode shapes for this system that + + align:start position:0% +the mode shapes for this system that + + + align:start position:0% +the mode shapes for this system that +goes with that U comes out to be + + align:start position:0% +goes with that U comes out to be + + + align:start position:0% +goes with that U comes out to be +1.0 + + align:start position:0% +1.0 + + + align:start position:0% +1.0 +and + + align:start position:0% +and + + + align:start position:0% +and +2. + + align:start position:0% + + + + align:start position:0% + +2667 that's mode I'll do this to help + + align:start position:0% +2667 that's mode I'll do this to help + + + align:start position:0% +2667 that's mode I'll do this to help +you the columns are the mode shapes + + align:start position:0% +you the columns are the mode shapes + + + align:start position:0% +you the columns are the mode shapes +that's the first mode shape and the + + align:start position:0% +that's the first mode shape and the + + + align:start position:0% +that's the first mode shape and the +second mode + + align:start position:0% +second mode + + + align:start position:0% +second mode +shape is + + align:start position:0% +shape is + + + align:start position:0% +shape is +one and minus + + align:start position:0% +one and minus + + + align:start position:0% +one and minus +0 22 3 + + align:start position:0% +0 22 3 + + + align:start position:0% +0 22 3 +six so that's your mode so those are the + + align:start position:0% +six so that's your mode so those are the + + + align:start position:0% +six so that's your mode so those are the +mode shapes for the first and second + + align:start position:0% +mode shapes for the first and second + + + align:start position:0% +mode shapes for the first and second +mode that go with these two natural + + align:start position:0% +mode that go with these two natural + + + align:start position:0% +mode that go with these two natural +frequencies so that's for this system + + align:start position:0% +frequencies so that's for this system + + + align:start position:0% +frequencies so that's for this system +the top one moves one unit the bottom + + align:start position:0% +the top one moves one unit the bottom + + + align:start position:0% +the top one moves one unit the bottom +one moves + + align:start position:0% +one moves + + + align:start position:0% +one moves +2.27 times that same direction positive + + align:start position:0% +2.27 times that same direction positive + + + align:start position:0% +2.27 times that same direction positive +positive the upper one moves one unit + + align:start position:0% +positive the upper one moves one unit + + + align:start position:0% +positive the upper one moves one unit +the bottom one moves the opposite + + align:start position:0% +the bottom one moves the opposite + + + align:start position:0% +the bottom one moves the opposite +direction that's the minus signs + + align:start position:0% +direction that's the minus signs + + + align:start position:0% +direction that's the minus signs +equivalent to a phase angle of + + align:start position:0% +equivalent to a phase angle of + + + align:start position:0% +equivalent to a phase angle of +180° minus 22% of the amount that the + + align:start position:0% +180° minus 22% of the amount that the + + + align:start position:0% +180° minus 22% of the amount that the +upper one moves so first one + + align:start position:0% +upper one moves so first one + + + align:start position:0% +upper one moves so first one +moves one unit the bottom one moves 2.2 + + align:start position:0% +moves one unit the bottom one moves 2.2 + + + align:start position:0% +moves one unit the bottom one moves 2.2 +times + + align:start position:0% +times + + + align:start position:0% +times +that and in the second mode which is + + align:start position:0% +that and in the second mode which is + + + align:start position:0% +that and in the second mode which is +much harder to get + + align:start position:0% + + + + align:start position:0% + +going gu the only way I can do it is to + + align:start position:0% +going gu the only way I can do it is to + + + align:start position:0% +going gu the only way I can do it is to +do it the way Professor goser intended + + align:start position:0% + + + + align:start position:0% + +here one unit up and down + + align:start position:0% +here one unit up and down + + + align:start position:0% +here one unit up and down +minus 2236 + + align:start position:0% +minus 2236 + + + align:start position:0% +minus 2236 +going the opposite way so those are our + + align:start position:0% +going the opposite way so those are our + + + align:start position:0% +going the opposite way so those are our +mode shapes these are the natural + + align:start position:0% +mode shapes these are the natural + + + align:start position:0% +mode shapes these are the natural +frequencies I calculated this one and + + align:start position:0% +frequencies I calculated this one and + + + align:start position:0% +frequencies I calculated this one and +measured it with stopwatch this one I + + align:start position:0% +measured it with stopwatch this one I + + + align:start position:0% +measured it with stopwatch this one I +can do watching it with a stopwatch and + + align:start position:0% +can do watching it with a stopwatch and + + + align:start position:0% +can do watching it with a stopwatch and +I came within less better than 1% + + align:start position:0% +I came within less better than 1% + + + align:start position:0% +I came within less better than 1% +getting the same + + align:start position:0% +getting the same + + + align:start position:0% +getting the same +number okay + + align:start position:0% + + + + align:start position:0% + +so I carry I want my modal Mass Matrix I + + align:start position:0% +so I carry I want my modal Mass Matrix I + + + align:start position:0% +so I carry I want my modal Mass Matrix I +carry out this calculation and for this + + align:start position:0% +carry out this calculation and for this + + + align:start position:0% +carry out this calculation and for this +system remember it's going to give me + + align:start position:0% +system remember it's going to give me + + + align:start position:0% +system remember it's going to give me +back a diagonal matrix looking like + + align:start position:0% +back a diagonal matrix looking like + + + align:start position:0% +back a diagonal matrix looking like +this and in fact the numbers are + + align:start position:0% + + + + align:start position:0% + +35562 z0 + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +358 and when I can calculate U transpose + + align:start position:0% +358 and when I can calculate U transpose + + + align:start position:0% +358 and when I can calculate U transpose +k + + align:start position:0% +k + + + align:start position:0% +k +u gives me a diagonal stiffness + + align:start position:0% + + + + align:start position:0% + +Matrix and I get the numbers 1 1 + + align:start position:0% +Matrix and I get the numbers 1 1 + + + align:start position:0% +Matrix and I get the numbers 1 1 + + align:start position:0% + + + align:start position:0% + + align:start position:0% + + + align:start position:0% +1 and + + align:start position:0% +1 and + + + align:start position:0% +1 and +and 0 + + align:start position:0% +and 0 + + + align:start position:0% +and 0 +0 1 + + align:start position:0% + + + + align:start position:0% + +9839 and that's my diagonal diagonalized + + align:start position:0% +9839 and that's my diagonal diagonalized + + + align:start position:0% +9839 and that's my diagonal diagonalized +stiffness + + align:start position:0% +stiffness + + + align:start position:0% +stiffness +Matrix now something had better be true + + align:start position:0% +Matrix now something had better be true + + + align:start position:0% +Matrix now something had better be true +I'm saying that this is this is now + + align:start position:0% +I'm saying that this is this is now + + + align:start position:0% +I'm saying that this is this is now +going to give me my two independent + + align:start position:0% +going to give me my two independent + + + align:start position:0% +going to give me my two independent +single degree of Frum equations of + + align:start position:0% +single degree of Frum equations of + + + align:start position:0% +single degree of Frum equations of +motion right so I'm looking for + + align:start position:0% + + + + align:start position:0% + +so what I'm seeking here I want to get + + align:start position:0% +so what I'm seeking here I want to get + + + align:start position:0% +so what I'm seeking here I want to get +two equations one that looks like + + align:start position:0% +two equations one that looks like + + + align:start position:0% +two equations one that looks like +M1 q1 dot plus + + align:start position:0% +M1 q1 dot plus + + + align:start position:0% +M1 q1 dot plus +C1 q1 dot plus K1 q1 equals zero for no + + align:start position:0% +C1 q1 dot plus K1 q1 equals zero for no + + + align:start position:0% +C1 q1 dot plus K1 q1 equals zero for no +external Force that's one of the + + align:start position:0% +external Force that's one of the + + + align:start position:0% +external Force that's one of the +equations I'm after and the other one it + + align:start position:0% +equations I'm after and the other one it + + + align:start position:0% +equations I'm after and the other one it +look like + + align:start position:0% +look like + + + align:start position:0% +look like +M2 Q2 dot plus c 2 Q2 + + align:start position:0% +M2 Q2 dot plus c 2 Q2 + + + align:start position:0% +M2 Q2 dot plus c 2 Q2 +do K2 + + align:start position:0% +do K2 + + + align:start position:0% +do K2 +Q2 now one way to check that you've + + align:start position:0% +Q2 now one way to check that you've + + + align:start position:0% +Q2 now one way to check that you've +gotten the right thing is now these are + + align:start position:0% +gotten the right thing is now these are + + + align:start position:0% +gotten the right thing is now these are +independent two independent single + + align:start position:0% +independent two independent single + + + align:start position:0% +independent two independent single +degree Freedom systems what's the + + align:start position:0% +degree Freedom systems what's the + + + align:start position:0% +degree Freedom systems what's the +natural frequency of this + + align:start position:0% + + + + align:start position:0% + +system yeah actually I heard somebody + + align:start position:0% +system yeah actually I heard somebody + + + align:start position:0% +system yeah actually I heard somebody +say square root of K1 over M1 that it + + align:start position:0% +say square root of K1 over M1 that it + + + align:start position:0% +say square root of K1 over M1 that it +better be true but what numerically + + align:start position:0% +better be true but what numerically + + + align:start position:0% +better be true but what numerically +what's the number what did it better + + align:start position:0% +what's the number what did it better + + + align:start position:0% +what's the number what did it better +be it better be the Omega 1 of the + + align:start position:0% +be it better be the Omega 1 of the + + + align:start position:0% +be it better be the Omega 1 of the +system right and so a check that you can + + align:start position:0% +system right and so a check that you can + + + align:start position:0% +system right and so a check that you can +perform is is to + + align:start position:0% +perform is is to + + + align:start position:0% +perform is is to +check to see if the Omega 1 squared + + align:start position:0% +check to see if the Omega 1 squared + + + align:start position:0% +check to see if the Omega 1 squared +equal K1 over M1 just you found two + + align:start position:0% +equal K1 over M1 just you found two + + + align:start position:0% +equal K1 over M1 just you found two +numbers you've got uh up here K1 is + + align:start position:0% +numbers you've got uh up here K1 is + + + align:start position:0% +numbers you've got uh up here K1 is +113.9 + + align:start position:0% + + + + align:start position:0% + +M1 is 3.55 take K1 over + + align:start position:0% +M1 is 3.55 take K1 over + + + align:start position:0% +M1 is 3.55 take K1 over +M1 and take its square root so K1 over + + align:start position:0% +M1 and take its square root so K1 over + + + align:start position:0% +M1 and take its square root so K1 over +M1 that's about + + align:start position:0% +M1 that's about + + + align:start position:0% +M1 that's about + + align:start position:0% + + + align:start position:0% +something square root of 30 something is + + align:start position:0% +something square root of 30 something is + + + align:start position:0% +something square root of 30 something is +a little less than + + align:start position:0% +a little less than + + + align:start position:0% +a little less than +six Omega 1 is + + align:start position:0% +six Omega 1 is + + + align:start position:0% +six Omega 1 is +5.65 and the same thing Omega 2 had + + align:start position:0% +5.65 and the same thing Omega 2 had + + + align:start position:0% +5.65 and the same thing Omega 2 had +better be equal to the square < TK of + + align:start position:0% +better be equal to the square < TK of + + + align:start position:0% +better be equal to the square < TK of +K2 over M2 so one one of the things you + + align:start position:0% +K2 over M2 so one one of the things you + + + align:start position:0% +K2 over M2 so one one of the things you +can always do when you do your modal + + align:start position:0% +can always do when you do your modal + + + align:start position:0% +can always do when you do your modal +analysis you do your calculations youut + + align:start position:0% +analysis you do your calculations youut + + + align:start position:0% +analysis you do your calculations youut +transpose mu you transpose KU if you + + align:start position:0% +transpose mu you transpose KU if you + + + align:start position:0% +transpose mu you transpose KU if you +calculate the ratios of each one of + + align:start position:0% +calculate the ratios of each one of + + + align:start position:0% +calculate the ratios of each one of +these things you can go back and check + + align:start position:0% +these things you can go back and check + + + align:start position:0% +these things you can go back and check +and see the natural frequencies are the + + align:start position:0% +and see the natural frequencies are the + + + align:start position:0% +and see the natural frequencies are the +ones that you started with if you have + + align:start position:0% +ones that you started with if you have + + + align:start position:0% +ones that you started with if you have +if they are not then you've messed up in + + align:start position:0% +if they are not then you've messed up in + + + align:start position:0% +if they are not then you've messed up in +your arithmetic so now we've got our two + + align:start position:0% +your arithmetic so now we've got our two + + + align:start position:0% +your arithmetic so now we've got our two +impendent equations and the natural + + align:start position:0% +impendent equations and the natural + + + align:start position:0% +impendent equations and the natural +frequencies check + + align:start position:0% +frequencies check + + + align:start position:0% +frequencies check +out but we haven't uh we we still have a + + align:start position:0% +out but we haven't uh we we still have a + + + align:start position:0% +out but we haven't uh we we still have a +couple of things to deal with we have to + + align:start position:0% +couple of things to deal with we have to + + + align:start position:0% +couple of things to deal with we have to +figure out how to can calculate the + + align:start position:0% +figure out how to can calculate the + + + align:start position:0% +figure out how to can calculate the +initial conditions and we have to figure + + align:start position:0% +initial conditions and we have to figure + + + align:start position:0% +initial conditions and we have to figure +out how to deal with + + align:start position:0% + + + + align:start position:0% + +damping let's do + + align:start position:0% +damping let's do + + + align:start position:0% +damping let's do +initial I's + + align:start position:0% + + + + align:start position:0% + +first so those of you who were here last + + align:start position:0% +first so those of you who were here last + + + align:start position:0% +first so those of you who were here last +time I ended kind right at the + + align:start position:0% +time I ended kind right at the + + + align:start position:0% +time I ended kind right at the +end we kind of worked our way through + + align:start position:0% +end we kind of worked our way through + + + align:start position:0% +end we kind of worked our way through +figuring out the initial conditions for + + align:start position:0% +figuring out the initial conditions for + + + align:start position:0% +figuring out the initial conditions for +a two degree Freedom system doing it the + + align:start position:0% +a two degree Freedom system doing it the + + + align:start position:0% +a two degree Freedom system doing it the +hard way end up with four equations and + + align:start position:0% +hard way end up with four equations and + + + align:start position:0% +hard way end up with four equations and +four unknowns for the A1 A2 F1 F2 + + align:start position:0% +four unknowns for the A1 A2 F1 F2 + + + align:start position:0% +four unknowns for the A1 A2 F1 F2 +remember that I mean it's really + + align:start position:0% +remember that I mean it's really + + + align:start position:0% +remember that I mean it's really +painful there's a this this is + + align:start position:0% +painful there's a this this is + + + align:start position:0% +painful there's a this this is +incredibly easier we're going to do the + + align:start position:0% +incredibly easier we're going to do the + + + align:start position:0% +incredibly easier we're going to do the +same thing + + align:start position:0% +same thing + + + align:start position:0% +same thing +but extremely easily so I I would never + + align:start position:0% +but extremely easily so I I would never + + + align:start position:0% +but extremely easily so I I would never +go myself given the choice of grinding + + align:start position:0% +go myself given the choice of grinding + + + align:start position:0% +go myself given the choice of grinding +not all those phas angles and amplitudes + + align:start position:0% +not all those phas angles and amplitudes + + + align:start position:0% +not all those phas angles and amplitudes +I by in simultaneous equations I'd do + + align:start position:0% +I by in simultaneous equations I'd do + + + align:start position:0% +I by in simultaneous equations I'd do +the following how if I generally now I + + align:start position:0% +the following how if I generally now I + + + align:start position:0% +the following how if I generally now I +know the initial conditions are going to + + align:start position:0% +know the initial conditions are going to + + + align:start position:0% +know the initial conditions are going to +be specified not in Q coordinates but in + + align:start position:0% +be specified not in Q coordinates but in + + + align:start position:0% +be specified not in Q coordinates but in +what coordinate + + align:start position:0% + + + + align:start position:0% + +system your original generalized + + align:start position:0% +system your original generalized + + + align:start position:0% +system your original generalized +coordinates right you going to know + + align:start position:0% +coordinates right you going to know + + + align:start position:0% +coordinates right you going to know +you're X on this one the general if I'm + + align:start position:0% +you're X on this one the general if I'm + + + align:start position:0% +you're X on this one the general if I'm +going to set initial conditions here I'm + + align:start position:0% +going to set initial conditions here I'm + + + align:start position:0% +going to set initial conditions here I'm +not going to say q1 is equal to + + align:start position:0% +not going to say q1 is equal to + + + align:start position:0% +not going to say q1 is equal to +something I'm going to say I'm going to + + align:start position:0% +something I'm going to say I'm going to + + + align:start position:0% +something I'm going to say I'm going to +put this one down one unit and this one + + align:start position:0% +put this one down one unit and this one + + + align:start position:0% +put this one down one unit and this one +down two units and like go this is in X1 + + align:start position:0% +down two units and like go this is in X1 + + + align:start position:0% +down two units and like go this is in X1 +and X2 coordinates but the beautiful + + align:start position:0% +and X2 coordinates but the beautiful + + + align:start position:0% +and X2 coordinates but the beautiful +thing here is that we know that + + align:start position:0% +thing here is that we know that + + + align:start position:0% +thing here is that we know that +x equals u + + align:start position:0% +x equals u + + + align:start position:0% +x equals u +q so if I know the initial conditions on + + align:start position:0% +q so if I know the initial conditions on + + + align:start position:0% +q so if I know the initial conditions on +I'll call it X knot + + align:start position:0% +I'll call it X knot + + + align:start position:0% +I'll call it X knot +here if I know the initial deflections + + align:start position:0% +here if I know the initial deflections + + + align:start position:0% +here if I know the initial deflections +of the system they're going to be U + + align:start position:0% +of the system they're going to be U + + + align:start position:0% +of the system they're going to be U +times the initial value the initial + + align:start position:0% +times the initial value the initial + + + align:start position:0% +times the initial value the initial +values of Q + + align:start position:0% +values of Q + + + align:start position:0% +values of Q +and if I know a vector of initial + + align:start position:0% +and if I know a vector of initial + + + align:start position:0% +and if I know a vector of initial +velocities at Time Zero they're going to + + align:start position:0% +velocities at Time Zero they're going to + + + align:start position:0% +velocities at Time Zero they're going to +be U q0 + + align:start position:0% + + + + align:start position:0% + +dot so if I told you values of X knot + + align:start position:0% +dot so if I told you values of X knot + + + align:start position:0% +dot so if I told you values of X knot +and I and you know that this equation is + + align:start position:0% +and I and you know that this equation is + + + align:start position:0% +and I and you know that this equation is +true what we need is Q the Q knots we + + align:start position:0% +true what we need is Q the Q knots we + + + align:start position:0% +true what we need is Q the Q knots we +need the initial conditions in that in a + + align:start position:0% +need the initial conditions in that in a + + + align:start position:0% +need the initial conditions in that in a +modal coordinates in order to finish + + align:start position:0% +modal coordinates in order to finish + + + align:start position:0% +modal coordinates in order to finish +this problem how would you get if I told + + align:start position:0% +this problem how would you get if I told + + + align:start position:0% +this problem how would you get if I told +you this how would you solve for that + + align:start position:0% + + + + align:start position:0% + +just a little linear algebra + + align:start position:0% + + + + align:start position:0% + +here inverse Matrix of you yeah do what + + align:start position:0% +here inverse Matrix of you yeah do what + + + align:start position:0% +here inverse Matrix of you yeah do what +with it and you multiply multipli + + align:start position:0% +with it and you multiply multipli + + + align:start position:0% +with it and you multiply multipli +by U inverse right okay so this + + align:start position:0% +by U inverse right okay so this + + + align:start position:0% +by U inverse right okay so this +implies + + align:start position:0% +implies + + + align:start position:0% +implies +that + + align:start position:0% +that + + + align:start position:0% +that +Q + + align:start position:0% + + + + align:start position:0% + +not well better I'll write it out a + + align:start position:0% +not well better I'll write it out a + + + align:start position:0% +not well better I'll write it out a +little more fully here so if I + + align:start position:0% +little more fully here so if I + + + align:start position:0% +little more fully here so if I +do U + + align:start position:0% +do U + + + align:start position:0% +do U +inverse X + + align:start position:0% + + + + align:start position:0% + +knot that's going to be equal to U + + align:start position:0% +knot that's going to be equal to U + + + align:start position:0% +knot that's going to be equal to U +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +u q + + align:start position:0% +u q + + + align:start position:0% +u q +knot U inverse time U gives you one + + align:start position:0% +knot U inverse time U gives you one + + + align:start position:0% +knot U inverse time U gives you one +basically right and so I have just if I + + align:start position:0% +basically right and so I have just if I + + + align:start position:0% +basically right and so I have just if I +do U inverse X + + align:start position:0% +do U inverse X + + + align:start position:0% +do U inverse X +knot I get Q + + align:start position:0% + + + + align:start position:0% + +that's all there is to it + + align:start position:0% + + + + align:start position:0% + +yeah I C is a problem okay I'm leaving + + align:start position:0% +yeah I C is a problem okay I'm leaving + + + align:start position:0% +yeah I C is a problem okay I'm leaving +it I'm leaving it to the end we're going + + align:start position:0% +it I'm leaving it to the end we're going + + + align:start position:0% +it I'm leaving it to the end we're going +to deal with it as the last step and if + + align:start position:0% +to deal with it as the last step and if + + + align:start position:0% +to deal with it as the last step and if +I have initial velocities U inverse + + align:start position:0% +I have initial velocities U inverse + + + align:start position:0% +I have initial velocities U inverse +times x initial velocities Vector I get + + align:start position:0% +times x initial velocities Vector I get + + + align:start position:0% +times x initial velocities Vector I get +the initial velocities Vector in the + + align:start position:0% +the initial velocities Vector in the + + + align:start position:0% +the initial velocities Vector in the +natural + + align:start position:0% +natural + + + align:start position:0% +natural +coordinates so that's how simple it is + + align:start position:0% +coordinates so that's how simple it is + + + align:start position:0% +coordinates so that's how simple it is +to get the initial conditions in modal + + align:start position:0% +to get the initial conditions in modal + + + align:start position:0% +to get the initial conditions in modal +coordinates + + align:start position:0% +coordinates + + + align:start position:0% +coordinates +boom + + align:start position:0% + + + + align:start position:0% + +okay and we're going to we'll do a + + align:start position:0% +okay and we're going to we'll do a + + + align:start position:0% +okay and we're going to we'll do a +numerical example in a second + + align:start position:0% + + + + align:start position:0% + +here we're looking for we're seeking a + + align:start position:0% +here we're looking for we're seeking a + + + align:start position:0% +here we're looking for we're seeking a +solution of the + + align:start position:0% +solution of the + + + align:start position:0% +solution of the +form to do initial to do uh response to + + align:start position:0% +form to do initial to do uh response to + + + align:start position:0% +form to do initial to do uh response to +initial + + align:start position:0% + + + + align:start position:0% + +conditions we seek + + align:start position:0% + + + + align:start position:0% + +equations that we know a right for a + + align:start position:0% +equations that we know a right for a + + + align:start position:0% +equations that we know a right for a +single degree of Freedom system response + + align:start position:0% +single degree of Freedom system response + + + align:start position:0% +single degree of Freedom system response +to initial conditions so we know that + + align:start position:0% +to initial conditions so we know that + + + align:start position:0% +to initial conditions so we know that +for a single degree of Freedom system X + + align:start position:0% +for a single degree of Freedom system X + + + align:start position:0% +for a single degree of Freedom system X +of T this is for SDF for + + align:start position:0% +of T this is for SDF for + + + align:start position:0% +of T this is for SDF for +SDF system + + align:start position:0% +SDF system + + + align:start position:0% +SDF system +here x of t + + align:start position:0% + + + + align:start position:0% + +we've worked out before is equal to some + + align:start position:0% +we've worked out before is equal to some + + + align:start position:0% +we've worked out before is equal to some +e to the minus Zeta Omega n t this is + + align:start position:0% +e to the minus Zeta Omega n t this is + + + align:start position:0% +e to the minus Zeta Omega n t this is +just a transient Decay problem of + + align:start position:0% +just a transient Decay problem of + + + align:start position:0% +just a transient Decay problem of +xnot cosine Omega + + align:start position:0% +xnot cosine Omega + + + align:start position:0% +xnot cosine Omega +DT + + align:start position:0% +DT + + + align:start position:0% +DT +plus + + align:start position:0% +plus + + + align:start position:0% +plus +V plus Zeta Omega n x + + align:start position:0% +V plus Zeta Omega n x + + + align:start position:0% +V plus Zeta Omega n x +knot all over Omega + + align:start position:0% +knot all over Omega + + + align:start position:0% +knot all over Omega +D + + align:start position:0% +D + + + align:start position:0% +D +sin Omega DT we know that that's what + + align:start position:0% +sin Omega DT we know that that's what + + + align:start position:0% +sin Omega DT we know that that's what +the response of a single degree Freedom + + align:start position:0% +the response of a single degree Freedom + + + align:start position:0% +the response of a single degree Freedom +system looks like to initial conditions + + align:start position:0% +system looks like to initial conditions + + + align:start position:0% +system looks like to initial conditions +X knot and V + + align:start position:0% +X knot and V + + + align:start position:0% +X knot and V +KN and for light damping for small + + align:start position:0% +KN and for light damping for small + + + align:start position:0% +KN and for light damping for small +damping you can off usually even ignore + + align:start position:0% +damping you can off usually even ignore + + + align:start position:0% +damping you can off usually even ignore +this term so it's just it's even + + align:start position:0% +this term so it's just it's even + + + align:start position:0% +this term so it's just it's even +simpler this term is usually small + + align:start position:0% +simpler this term is usually small + + + align:start position:0% +simpler this term is usually small +compared to the + + align:start position:0% +compared to the + + + align:start position:0% +compared to the +all right small this term contribution + + align:start position:0% +all right small this term contribution + + + align:start position:0% +all right small this term contribution +from X notot is small compared to this + + align:start position:0% +from X notot is small compared to this + + + align:start position:0% +from X notot is small compared to this +term so it's basically dominated by an x + + align:start position:0% +term so it's basically dominated by an x + + + align:start position:0% +term so it's basically dominated by an x +cosine and a v over Omega D sin but + + align:start position:0% +cosine and a v over Omega D sin but + + + align:start position:0% +cosine and a v over Omega D sin but +that's the we know that's the exact + + align:start position:0% +that's the we know that's the exact + + + align:start position:0% +that's the we know that's the exact +response to a a single degree Freedom + + align:start position:0% +response to a a single degree Freedom + + + align:start position:0% +response to a a single degree Freedom +system to initial conditions so just by + + align:start position:0% +system to initial conditions so just by + + + align:start position:0% +system to initial conditions so just by +analogy to that we're looking for for + + align:start position:0% +analogy to that we're looking for for + + + align:start position:0% +analogy to that we're looking for for +mode one in modal coordinates it's going + + align:start position:0% +mode one in modal coordinates it's going + + + align:start position:0% +mode one in modal coordinates it's going +to look exactly the same way e the minus + + align:start position:0% +to look exactly the same way e the minus + + + align:start position:0% +to look exactly the same way e the minus +Theta Omega n t + + align:start position:0% +Theta Omega n t + + + align:start position:0% +Theta Omega n t +Q + + align:start position:0% +Q + + + align:start position:0% +Q +not cosine Omega + + align:start position:0% +not cosine Omega + + + align:start position:0% +not cosine Omega + + align:start position:0% + + + align:start position:0% +D this is Omega + + align:start position:0% + + + + align:start position:0% + +DT plus Q KN dot plus Zeta 1 Omega + + align:start position:0% +DT plus Q KN dot plus Zeta 1 Omega + + + align:start position:0% +DT plus Q KN dot plus Zeta 1 Omega +1 Q KN I guess I need to do q1 + + align:start position:0% +1 Q KN I guess I need to do q1 + + + align:start position:0% +1 Q KN I guess I need to do q1 +KN like + + align:start position:0% +KN like + + + align:start position:0% +KN like +that this is the mo first modes equation + + align:start position:0% +that this is the mo first modes equation + + + align:start position:0% +that this is the mo first modes equation +Zeta 1 and I'll call this Omega one but + + align:start position:0% +Zeta 1 and I'll call this Omega one but + + + align:start position:0% +Zeta 1 and I'll call this Omega one but +now that you get multiple degree Freedom + + align:start position:0% +now that you get multiple degree Freedom + + + align:start position:0% +now that you get multiple degree Freedom +systems you got to keep track of what + + align:start position:0% +systems you got to keep track of what + + + align:start position:0% +systems you got to keep track of what +mode you're talking about mode one + + align:start position:0% +mode you're talking about mode one + + + align:start position:0% +mode you're talking about mode one +damping ratio mode one natural frequency + + align:start position:0% +damping ratio mode one natural frequency + + + align:start position:0% +damping ratio mode one natural frequency +mode One initial displacement mode One + + align:start position:0% +mode One initial displacement mode One + + + align:start position:0% +mode One initial displacement mode One +initial velocity mode + + align:start position:0% +initial velocity mode + + + align:start position:0% +initial velocity mode +one Omega 1 D like that and mode two is + + align:start position:0% +one Omega 1 D like that and mode two is + + + align:start position:0% +one Omega 1 D like that and mode two is +going to be exactly analogous + + align:start position:0% +going to be exactly analogous + + + align:start position:0% +going to be exactly analogous +Q2 equals and + + align:start position:0% +Q2 equals and + + + align:start position:0% +Q2 equals and +it's exactly similar except you put it + + align:start position:0% +it's exactly similar except you put it + + + align:start position:0% +it's exactly similar except you put it +update it with a two instead of a + + align:start position:0% + + + + align:start position:0% + +one and if you plug in the initial you + + align:start position:0% +one and if you plug in the initial you + + + align:start position:0% +one and if you plug in the initial you +over here have found the initial values + + align:start position:0% +over here have found the initial values + + + align:start position:0% +over here have found the initial values +for + + align:start position:0% +for + + + align:start position:0% +for +Q one and one KN and Q2 KN and q1 do not + + align:start position:0% +Q one and one KN and Q2 KN and q1 do not + + + align:start position:0% +Q one and one KN and Q2 KN and q1 do not +and so forth you found the initial + + align:start position:0% +and so forth you found the initial + + + align:start position:0% +and so forth you found the initial +values that go plug into that equation + + align:start position:0% +values that go plug into that equation + + + align:start position:0% +values that go plug into that equation +by just doing + + align:start position:0% +by just doing + + + align:start position:0% +by just doing +this and once we have this then we can + + align:start position:0% +this and once we have this then we can + + + align:start position:0% +this and once we have this then we can +go back to saying how do you get to the + + align:start position:0% +go back to saying how do you get to the + + + align:start position:0% +go back to saying how do you get to the +get back to the final answer well you + + align:start position:0% +get back to the final answer well you + + + align:start position:0% +get back to the final answer well you +just multiply the result for Q times the + + align:start position:0% +just multiply the result for Q times the + + + align:start position:0% +just multiply the result for Q times the +mode shape and add them up and you have + + align:start position:0% +mode shape and add them up and you have + + + align:start position:0% +mode shape and add them up and you have +the + + align:start position:0% +the + + + align:start position:0% +the +answer but we still have to deal with + + align:start position:0% +answer but we still have to deal with + + + align:start position:0% +answer but we still have to deal with +the damping + + align:start position:0% + + + + align:start position:0% + +problem I'm going to do that one next + + align:start position:0% +problem I'm going to do that one next + + + align:start position:0% +problem I'm going to do that one next +but I see a bunch of hands and some + + align:start position:0% +but I see a bunch of hands and some + + + align:start position:0% +but I see a bunch of hands and some +puzzled look so it means it's a good + + align:start position:0% +puzzled look so it means it's a good + + + align:start position:0% +puzzled look so it means it's a good +time to stop and talk for a second + + align:start position:0% + + + + align:start position:0% + +yeah pardon do I can't quite hear it S I + + align:start position:0% +yeah pardon do I can't quite hear it S I + + + align:start position:0% +yeah pardon do I can't quite hear it S I +mean s Omega DT yeah what about why do + + align:start position:0% +mean s Omega DT yeah what about why do + + + align:start position:0% +mean s Omega DT yeah what about why do +we lose it why do we use it lose it oh + + align:start position:0% +we lose it why do we use it lose it oh + + + align:start position:0% +we lose it why do we use it lose it oh +you don't lose it I was saying see this + + align:start position:0% +you don't lose it I was saying see this + + + align:start position:0% +you don't lose it I was saying see this +is this bit it's like that these are two + + align:start position:0% +is this bit it's like that these are two + + + align:start position:0% +is this bit it's like that these are two +pieces that behave like + + align:start position:0% +pieces that behave like + + + align:start position:0% +pieces that behave like +sign and this see this one depends on + + align:start position:0% +sign and this see this one depends on + + + align:start position:0% +sign and this see this one depends on +initial displacement but it's multiplied + + align:start position:0% +initial displacement but it's multiplied + + + align:start position:0% +initial displacement but it's multiplied +by the damping ratio the damping ratio + + align:start position:0% +by the damping ratio the damping ratio + + + align:start position:0% +by the damping ratio the damping ratio +for things that are interesting is + + align:start position:0% +for things that are interesting is + + + align:start position:0% +for things that are interesting is +usually pretty small so here you have a + + align:start position:0% +usually pretty small so here you have a + + + align:start position:0% +usually pretty small so here you have a +term that's xot cosine Omega 1 + + align:start position:0% + + + + align:start position:0% + +damped and here you have a contribution + + align:start position:0% +damped and here you have a contribution + + + align:start position:0% +damped and here you have a contribution +that's X notot small time x not sine + + align:start position:0% +that's X notot small time x not sine + + + align:start position:0% +that's X notot small time x not sine +Omega one Mega one damped so you + + align:start position:0% +Omega one Mega one damped so you + + + align:start position:0% +Omega one Mega one damped so you +multiply the same they're operating the + + align:start position:0% +multiply the same they're operating the + + + align:start position:0% +multiply the same they're operating the +same frequency two terms at the same + + align:start position:0% +same frequency two terms at the same + + + align:start position:0% +same frequency two terms at the same +frequency add them together it's like a + + align:start position:0% +frequency add them together it's like a + + + align:start position:0% +frequency add them together it's like a +cosine Omega T minus some phase angle if + + align:start position:0% +cosine Omega T minus some phase angle if + + + align:start position:0% +cosine Omega T minus some phase angle if +this little term is small that phase + + align:start position:0% +this little term is small that phase + + + align:start position:0% +this little term is small that phase +angle is almost zero + + align:start position:0% + + + + align:start position:0% + +cosine x cosine plus something x s it + + align:start position:0% +cosine x cosine plus something x s it + + + align:start position:0% +cosine x cosine plus something x s it +gives you a cosine term that has shifted + + align:start position:0% +gives you a cosine term that has shifted + + + align:start position:0% +gives you a cosine term that has shifted +a little bit and it's at magnitude is + + align:start position:0% +a little bit and it's at magnitude is + + + align:start position:0% +a little bit and it's at magnitude is +different by this little amount I'm just + + align:start position:0% +different by this little amount I'm just + + + align:start position:0% +different by this little amount I'm just +saying often times this is small but if + + align:start position:0% +saying often times this is small but if + + + align:start position:0% +saying often times this is small but if +you don't want to make that + + align:start position:0% +you don't want to make that + + + align:start position:0% +you don't want to make that +approximation just carry it along just + + align:start position:0% +approximation just carry it along just + + + align:start position:0% +approximation just carry it along just +do + + align:start position:0% + + + + align:start position:0% + +it oh no and I'm not throw I'm just + + align:start position:0% +it oh no and I'm not throw I'm just + + + align:start position:0% +it oh no and I'm not throw I'm just +saying you can take you can throw out + + align:start position:0% +saying you can take you can throw out + + + align:start position:0% +saying you can take you can throw out +this piece usually and it's simply it + + align:start position:0% +this piece usually and it's simply it + + + align:start position:0% +this piece usually and it's simply it +makes I keep in my + + align:start position:0% +makes I keep in my + + + align:start position:0% +makes I keep in my +mind vibr let me let me say kind of + + align:start position:0% +mind vibr let me let me say kind of + + + align:start position:0% +mind vibr let me let me say kind of +vibration engineering is full of lots of + + align:start position:0% +vibration engineering is full of lots of + + + align:start position:0% +vibration engineering is full of lots of +approximations because it's very hard to + + align:start position:0% +approximations because it's very hard to + + + align:start position:0% +approximations because it's very hard to +get oftentimes to get detailed + + align:start position:0% +get oftentimes to get detailed + + + align:start position:0% +get oftentimes to get detailed +quantitative numbers on exactly + + align:start position:0% +quantitative numbers on exactly + + + align:start position:0% +quantitative numbers on exactly +everything you need to know so I carry + + align:start position:0% +everything you need to know so I carry + + + align:start position:0% +everything you need to know so I carry +around little approximations that I know + + align:start position:0% +around little approximations that I know + + + align:start position:0% +around little approximations that I know +is the way the world mostly behaves and + + align:start position:0% +is the way the world mostly behaves and + + + align:start position:0% +is the way the world mostly behaves and +the way the world mostly behaves for a + + align:start position:0% +the way the world mostly behaves for a + + + align:start position:0% +the way the world mostly behaves for a +single degree Freedom system is the + + align:start position:0% +single degree Freedom system is the + + + align:start position:0% +single degree Freedom system is the +response to initial conditions looks + + align:start position:0% +response to initial conditions looks + + + align:start position:0% +response to initial conditions looks +like this + + align:start position:0% + + + + align:start position:0% + +and this initial value here is always + + align:start position:0% +and this initial value here is always + + + align:start position:0% +and this initial value here is always +approximately X + + align:start position:0% +approximately X + + + align:start position:0% +approximately X +knot and this initial slope here is + + align:start position:0% +knot and this initial slope here is + + + align:start position:0% +knot and this initial slope here is +always + + align:start position:0% +always + + + align:start position:0% +always +approximately uh tell the slope is + + align:start position:0% + + + + align:start position:0% + +vot that's the + + align:start position:0% +vot that's the + + + align:start position:0% +vot that's the +slope now it turns out that this thing + + align:start position:0% +slope now it turns out that this thing + + + align:start position:0% +slope now it turns out that this thing +has shifted just it's shifted just + + align:start position:0% +has shifted just it's shifted just + + + align:start position:0% +has shifted just it's shifted just +slightly why because of this + + align:start position:0% +slightly why because of this + + + align:start position:0% +slightly why because of this +term okay but I honest tell you the + + align:start position:0% +term okay but I honest tell you the + + + align:start position:0% +term okay but I honest tell you the +truth it almost really rarely matters so + + align:start position:0% +truth it almost really rarely matters so + + + align:start position:0% +truth it almost really rarely matters so +as a vibration engineer I often times + + align:start position:0% +as a vibration engineer I often times + + + align:start position:0% +as a vibration engineer I often times +just I just remember I have an xot + + align:start position:0% +just I just remember I have an xot + + + align:start position:0% +just I just remember I have an xot +cosine I have a vot over Mega D sign and + + align:start position:0% +cosine I have a vot over Mega D sign and + + + align:start position:0% +cosine I have a vot over Mega D sign and +the whole thing decays like that but if + + align:start position:0% +the whole thing decays like that but if + + + align:start position:0% +the whole thing decays like that but if +you like to be mathematically precise + + align:start position:0% +you like to be mathematically precise + + + align:start position:0% +you like to be mathematically precise +you carry along that little bit + + align:start position:0% +you carry along that little bit + + + align:start position:0% +you carry along that little bit +yeah you're not going to lose a + + align:start position:0% + + + + align:start position:0% + +sign oh oh wait a minute I just left it + + align:start position:0% +sign oh oh wait a minute I just left it + + + align:start position:0% +sign oh oh wait a minute I just left it +out ah you guys well I'm glad you're + + align:start position:0% +out ah you guys well I'm glad you're + + + align:start position:0% +out ah you guys well I'm glad you're +awake this is + + align:start position:0% + + + + align:start position:0% + +good now how's that ah good now I know + + align:start position:0% +good now how's that ah good now I know + + + align:start position:0% +good now how's that ah good now I know +how I had so many puzzled puzzle looks + + align:start position:0% +how I had so many puzzled puzzle looks + + + align:start position:0% +how I had so many puzzled puzzle looks +anybody have a different question just + + align:start position:0% +anybody have a different question just + + + align:start position:0% +anybody have a different question just +anything now about this whole modal + + align:start position:0% +anything now about this whole modal + + + align:start position:0% +anything now about this whole modal +analysis thing because then we have to + + align:start position:0% +analysis thing because then we have to + + + align:start position:0% +analysis thing because then we have to +deal with this awkward part that has to + + align:start position:0% +deal with this awkward part that has to + + + align:start position:0% +deal with this awkward part that has to +do with the + + align:start position:0% +do with the + + + align:start position:0% +do with the +damping and I got to finish on time + + align:start position:0% +damping and I got to finish on time + + + align:start position:0% +damping and I got to finish on time +okay the + + align:start position:0% +okay the + + + align:start position:0% +okay the +um all right + + align:start position:0% + + + + align:start position:0% + +so damping I've gotten this far I have + + align:start position:0% +so damping I've gotten this far I have + + + align:start position:0% +so damping I've gotten this far I have +what I need is I need estimates for the + + align:start position:0% +what I need is I need estimates for the + + + align:start position:0% +what I need is I need estimates for the +for the damping for uh mode one and + + align:start position:0% +for the damping for uh mode one and + + + align:start position:0% +for the damping for uh mode one and +damping for mode two + + align:start position:0% + + + + align:start position:0% + +right so the problem + + align:start position:0% + + + + align:start position:0% + +is that + + align:start position:0% +is that + + + align:start position:0% +is that +u c u does + + align:start position:0% + + + + align:start position:0% + +not + + align:start position:0% +not + + + align:start position:0% +not +always + + align:start position:0% +always + + + align:start position:0% +always +equal some nice + + align:start position:0% +equal some nice + + + align:start position:0% +equal some nice +diagonalized Matrix you sometimes get + + align:start position:0% +diagonalized Matrix you sometimes get + + + align:start position:0% +diagonalized Matrix you sometimes get +these are not always zero + + align:start position:0% + + + + align:start position:0% + +okay it just the orthogonality principle + + align:start position:0% +okay it just the orthogonality principle + + + align:start position:0% +okay it just the orthogonality principle +just doesn't apply to the damping + + align:start position:0% +just doesn't apply to the damping + + + align:start position:0% +just doesn't apply to the damping +terms just + + align:start position:0% +terms just + + + align:start position:0% +terms just +doesn't and but hasn't but this actually + + align:start position:0% +doesn't and but hasn't but this actually + + + align:start position:0% +doesn't and but hasn't but this actually +doesn't hurt you a lot you just got to + + align:start position:0% +doesn't hurt you a lot you just got to + + + align:start position:0% +doesn't hurt you a lot you just got to +know that this is going to be a problem + + align:start position:0% +know that this is going to be a problem + + + align:start position:0% +know that this is going to be a problem +and when the systems are lightly damped + + align:start position:0% +and when the systems are lightly damped + + + align:start position:0% +and when the systems are lightly damped +the approximation even if you're the + + align:start position:0% +the approximation even if you're the + + + align:start position:0% +the approximation even if you're the +true damping in the system gives you + + align:start position:0% +true damping in the system gives you + + + align:start position:0% +true damping in the system gives you +some nonzero elements here the the first + + align:start position:0% +some nonzero elements here the the first + + + align:start position:0% +some nonzero elements here the the first +order behavior of the system is + + align:start position:0% +order behavior of the system is + + + align:start position:0% +order behavior of the system is +basically going to be you can just + + align:start position:0% +basically going to be you can just + + + align:start position:0% +basically going to be you can just +ignore the off diagonal elements what + + align:start position:0% +ignore the off diagonal elements what + + + align:start position:0% +ignore the off diagonal elements what +practical consequence do you think it + + align:start position:0% +practical consequence do you think it + + + align:start position:0% +practical consequence do you think it +has if these if you have some actual + + align:start position:0% +has if these if you have some actual + + + align:start position:0% +has if these if you have some actual +nonzero numbers + + align:start position:0% +nonzero numbers + + + align:start position:0% +nonzero numbers +here go back and look at the equations + + align:start position:0% +here go back and look at the equations + + + align:start position:0% +here go back and look at the equations +that you were trying to + + align:start position:0% +that you were trying to + + + align:start position:0% +that you were trying to +derive it's these were the equations + + align:start position:0% +derive it's these were the equations + + + align:start position:0% +derive it's these were the equations +that we were trying to come up with and + + align:start position:0% +that we were trying to come up with and + + + align:start position:0% +that we were trying to come up with and +we wanted them to be in + + align:start position:0% +we wanted them to be in + + + align:start position:0% +we wanted them to be in +individual single degree Freedom systems + + align:start position:0% +individual single degree Freedom systems + + + align:start position:0% +individual single degree Freedom systems +but if this has off non-zero off + + align:start position:0% +but if this has off non-zero off + + + align:start position:0% +but if this has off non-zero off +diagonal terms you're going to find + + align:start position:0% +diagonal terms you're going to find + + + align:start position:0% +diagonal terms you're going to find +popping up in this single degree Freedom + + align:start position:0% +popping up in this single degree Freedom + + + align:start position:0% +popping up in this single degree Freedom +equation another term that couples it + + align:start position:0% +equation another term that couples it + + + align:start position:0% +equation another term that couples it +through damping to the other modes it + + align:start position:0% +through damping to the other modes it + + + align:start position:0% +through damping to the other modes it +provides a little bit of coupling to the + + align:start position:0% +provides a little bit of coupling to the + + + align:start position:0% +provides a little bit of coupling to the +other to other modes they can talk to + + align:start position:0% +other to other modes they can talk to + + + align:start position:0% +other to other modes they can talk to +one + + align:start position:0% +one + + + align:start position:0% +one +another all right and what that means is + + align:start position:0% +another all right and what that means is + + + align:start position:0% +another all right and what that means is +if I this may be a good time to do the + + align:start position:0% +if I this may be a good time to do the + + + align:start position:0% +if I this may be a good time to do the +the the + + align:start position:0% +the the + + + align:start position:0% +the the +demonstration um + + align:start position:0% + + + + align:start position:0% + +do I want to say + + align:start position:0% + + + + align:start position:0% + +this if the initial displacement of the + + align:start position:0% +this if the initial displacement of the + + + align:start position:0% +this if the initial displacement of the +system is in the + + align:start position:0% +system is in the + + + align:start position:0% +system is in the +shape of one of the natural + + align:start position:0% + + + + align:start position:0% + +modes so if this is some U this is + + align:start position:0% +modes so if this is some U this is + + + align:start position:0% +modes so if this is some U this is +exactly shaped like mode R so this looks + + align:start position:0% +exactly shaped like mode R so this looks + + + align:start position:0% +exactly shaped like mode R so this looks +like the UR Vector when I multiply it by + + align:start position:0% +like the UR Vector when I multiply it by + + + align:start position:0% +like the UR Vector when I multiply it by +this in when I when I multiply when I + + align:start position:0% +this in when I when I multiply when I + + + align:start position:0% +this in when I when I multiply when I +carry out this + + align:start position:0% +carry out this + + + align:start position:0% +carry out this +multiplication what do you think will + + align:start position:0% + + + + align:start position:0% + +happen if this shape if this is shaped + + align:start position:0% +happen if this shape if this is shaped + + + align:start position:0% +happen if this shape if this is shaped +like modar because of + + align:start position:0% +like modar because of + + + align:start position:0% +like modar because of +orthogonality when I do U inverse which + + align:start position:0% +orthogonality when I do U inverse which + + + align:start position:0% +orthogonality when I do U inverse which +is all about the mode shapes information + + align:start position:0% +is all about the mode shapes information + + + align:start position:0% +is all about the mode shapes information +and the mode shapes are or these + + align:start position:0% +and the mode shapes are or these + + + align:start position:0% +and the mode shapes are or these +orthogonal set of independent orthogonal + + align:start position:0% +orthogonal set of independent orthogonal + + + align:start position:0% +orthogonal set of independent orthogonal +vectors if this is exactly one mode and + + align:start position:0% +vectors if this is exactly one mode and + + + align:start position:0% +vectors if this is exactly one mode and +I do U inverse times that I will get + + align:start position:0% +I do U inverse times that I will get + + + align:start position:0% +I do U inverse times that I will get +zero over here on the right hand side + + align:start position:0% +zero over here on the right hand side + + + align:start position:0% +zero over here on the right hand side +for every mode except the mode that + + align:start position:0% +for every mode except the mode that + + + align:start position:0% +for every mode except the mode that +that's shaped + + align:start position:0% +that's shaped + + + align:start position:0% +that's shaped +like so if this is shaped like a that + + align:start position:0% +like so if this is shaped like a that + + + align:start position:0% +like so if this is shaped like a that +particular + + align:start position:0% +particular + + + align:start position:0% +particular +mode then over here all of the modal + + align:start position:0% +mode then over here all of the modal + + + align:start position:0% +mode then over here all of the modal +initial conditions are zero except that + + align:start position:0% +initial conditions are zero except that + + + align:start position:0% +initial conditions are zero except that +mode that means if I set this give its + + align:start position:0% +mode that means if I set this give its + + + align:start position:0% +mode that means if I set this give its +initial conditions are equal to the + + align:start position:0% +initial conditions are equal to the + + + align:start position:0% +initial conditions are equal to the +shape exactly of mode + + align:start position:0% + + + + align:start position:0% + +one it only responds in mode + + align:start position:0% +one it only responds in mode + + + align:start position:0% +one it only responds in mode +one and if I give it put it give it + + align:start position:0% +one and if I give it put it give it + + + align:start position:0% +one and if I give it put it give it +initial conditions that are exactly + + align:start position:0% +initial conditions that are exactly + + + align:start position:0% +initial conditions that are exactly +equal to shape like that of mode + + align:start position:0% +equal to shape like that of mode + + + align:start position:0% +equal to shape like that of mode +two then it only responds in mode + + align:start position:0% +two then it only responds in mode + + + align:start position:0% +two then it only responds in mode +two and if I give it anything + + align:start position:0% + + + + align:start position:0% + +else like I move just the top one but + + align:start position:0% +else like I move just the top one but + + + align:start position:0% +else like I move just the top one but +not the bottom and let it go then + + align:start position:0% +not the bottom and let it go then + + + align:start position:0% +not the bottom and let it go then +there's that one's maybe I better do the + + align:start position:0% +there's that one's maybe I better do the + + + align:start position:0% +there's that one's maybe I better do the +other one that one at too much of one + + align:start position:0% +other one that one at too much of one + + + align:start position:0% +other one that one at too much of one +not the other if I hold this one here's + + align:start position:0% +not the other if I hold this one here's + + + align:start position:0% +not the other if I hold this one here's +its reference I'm going to hold it right + + align:start position:0% +its reference I'm going to hold it right + + + align:start position:0% +its reference I'm going to hold it right +there and I'm going to give this one a + + align:start position:0% +there and I'm going to give this one a + + + align:start position:0% +there and I'm going to give this one a +unit deflection and let go + + align:start position:0% +unit deflection and let go + + + align:start position:0% +unit deflection and let go +now you see you got some of both all + + align:start position:0% +now you see you got some of both all + + + align:start position:0% +now you see you got some of both all +right + + align:start position:0% + + + + align:start position:0% + +so if when I + + align:start position:0% +so if when I + + + align:start position:0% +so if when I +do this first one say first + + align:start position:0% +do this first one say first + + + align:start position:0% +do this first one say first +mode I could sit here and measure how + + align:start position:0% +mode I could sit here and measure how + + + align:start position:0% +mode I could sit here and measure how +many cycles it takes to Decay halfway + + align:start position:0% +many cycles it takes to Decay halfway + + + align:start position:0% +many cycles it takes to Decay halfway +and estimate the damping ratio for that + + align:start position:0% +and estimate the damping ratio for that + + + align:start position:0% +and estimate the damping ratio for that +mode if it's only moving in this mode I + + align:start position:0% +mode if it's only moving in this mode I + + + align:start position:0% +mode if it's only moving in this mode I +can estimate it I could estimate it + + align:start position:0% +can estimate it I could estimate it + + + align:start position:0% +can estimate it I could estimate it +damping directly for that mode and get + + align:start position:0% +damping directly for that mode and get + + + align:start position:0% +damping directly for that mode and get +Zeta one you agree okay and if I did the + + align:start position:0% +Zeta one you agree okay and if I did the + + + align:start position:0% +Zeta one you agree okay and if I did the +same thing with mode two it's too fast + + align:start position:0% +same thing with mode two it's too fast + + + align:start position:0% +same thing with mode two it's too fast +for me to make my to catch it with a + + align:start position:0% +for me to make my to catch it with a + + + align:start position:0% +for me to make my to catch it with a +stopwatch but I could measure its + + align:start position:0% +stopwatch but I could measure its + + + align:start position:0% +stopwatch but I could measure its +damping and as it decays I could get an + + align:start position:0% +damping and as it decays I could get an + + + align:start position:0% +damping and as it decays I could get an +estimate for Zeta 2 for the damping + + align:start position:0% +estimate for Zeta 2 for the damping + + + align:start position:0% +estimate for Zeta 2 for the damping +ratio for mode two right all right and + + align:start position:0% +ratio for mode two right all right and + + + align:start position:0% +ratio for mode two right all right and +somehow I have to get damping ratio for + + align:start position:0% +somehow I have to get damping ratio for + + + align:start position:0% +somehow I have to get damping ratio for +mode one zeta 1 and damping ratio for + + align:start position:0% +mode one zeta 1 and damping ratio for + + + align:start position:0% +mode one zeta 1 and damping ratio for +mode two Zeta 2 I have to somehow get it + + align:start position:0% +mode two Zeta 2 I have to somehow get it + + + align:start position:0% +mode two Zeta 2 I have to somehow get it +out of this uh + + align:start position:0% +out of this uh + + + align:start position:0% +out of this uh +I have to model it somehow with these + + align:start position:0% +I have to model it somehow with these + + + align:start position:0% +I have to model it somehow with these +stamping coefficients that come from + + align:start position:0% +stamping coefficients that come from + + + align:start position:0% +stamping coefficients that come from +Computing this UT transposed + + align:start position:0% +Computing this UT transposed + + + align:start position:0% +Computing this UT transposed +CU + + align:start position:0% + + + + align:start position:0% + +okay so I'm going to this is I'm going + + align:start position:0% +okay so I'm going to this is I'm going + + + align:start position:0% +okay so I'm going to this is I'm going +to show you a kind of damping called ra + + align:start position:0% + + + + align:start position:0% + +damping okay Lord rley who did lots of + + align:start position:0% +damping okay Lord rley who did lots of + + + align:start position:0% +damping okay Lord rley who did lots of +things in science that you've probably + + align:start position:0% +things in science that you've probably + + + align:start position:0% +things in science that you've probably +run + + align:start position:0% +run + + + align:start position:0% +run +into um propose that if you let the + + align:start position:0% +into um propose that if you let the + + + align:start position:0% +into um propose that if you let the +damping if you model your damping the C + + align:start position:0% +damping if you model your damping the C + + + align:start position:0% +damping if you model your damping the C +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +as this is just now the system damping + + align:start position:0% +as this is just now the system damping + + + align:start position:0% +as this is just now the system damping +Matrix that you start with as + + align:start position:0% +Matrix that you start with as + + + align:start position:0% +Matrix that you start with as +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +sum + + align:start position:0% +sum + + + align:start position:0% +sum +Alpha times the mass Matrix plus beta + + align:start position:0% +Alpha times the mass Matrix plus beta + + + align:start position:0% +Alpha times the mass Matrix plus beta +time the stiffness Matrix these are now + + align:start position:0% +time the stiffness Matrix these are now + + + align:start position:0% +time the stiffness Matrix these are now +the original ones of your in your + + align:start position:0% +the original ones of your in your + + + align:start position:0% +the original ones of your in your +generalized coordinates it's your mass + + align:start position:0% +generalized coordinates it's your mass + + + align:start position:0% +generalized coordinates it's your mass +and stiffness matrices if you model if + + align:start position:0% +and stiffness matrices if you model if + + + align:start position:0% +and stiffness matrices if you model if +you say I'm going to approximate my + + align:start position:0% +you say I'm going to approximate my + + + align:start position:0% +you say I'm going to approximate my +damping model like this + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +then I want to compute U transpose + + align:start position:0% +then I want to compute U transpose + + + align:start position:0% +then I want to compute U transpose +CU I'm going to get Alpha you transpose + + align:start position:0% +CU I'm going to get Alpha you transpose + + + align:start position:0% +CU I'm going to get Alpha you transpose +m u plus beta you transpose k + + align:start position:0% +m u plus beta you transpose k + + + align:start position:0% +m u plus beta you transpose k +u but we know that this gives you the + + align:start position:0% +u but we know that this gives you the + + + align:start position:0% +u but we know that this gives you the +diagonalized mass Matrix and this known + + align:start position:0% +diagonalized mass Matrix and this known + + + align:start position:0% +diagonalized mass Matrix and this known +as a modal Mass Matrix this gives you + + align:start position:0% +as a modal Mass Matrix this gives you + + + align:start position:0% +as a modal Mass Matrix this gives you +the diagonalized stiffness Matrix and so + + align:start position:0% +the diagonalized stiffness Matrix and so + + + align:start position:0% +the diagonalized stiffness Matrix and so +this damping model this says this is + + align:start position:0% +this damping model this says this is + + + align:start position:0% +this damping model this says this is +guaranteed to give you a diagonalized + + align:start position:0% +guaranteed to give you a diagonalized + + + align:start position:0% +guaranteed to give you a diagonalized +damping + + align:start position:0% +damping + + + align:start position:0% +damping +Matrix which we'll call you know some + + align:start position:0% +Matrix which we'll call you know some + + + align:start position:0% +Matrix which we'll call you know some +have some Capital C1 0 0 + + align:start position:0% +have some Capital C1 0 0 + + + align:start position:0% +have some Capital C1 0 0 +C2 right and it's going to be Alpha + + align:start position:0% +C2 right and it's going to be Alpha + + + align:start position:0% +C2 right and it's going to be Alpha +times the modal Mass + + align:start position:0% + + + + align:start position:0% + +Matrix plus a beta times the modal + + align:start position:0% +Matrix plus a beta times the modal + + + align:start position:0% +Matrix plus a beta times the modal +stiffness + + align:start position:0% +stiffness + + + align:start position:0% +stiffness +Matrix and these alphas and betas you + + align:start position:0% +Matrix and these alphas and betas you + + + align:start position:0% +Matrix and these alphas and betas you +adjust they're just parameters you + + align:start position:0% +adjust they're just parameters you + + + align:start position:0% +adjust they're just parameters you +adjust to get the amount of damping you + + align:start position:0% +adjust to get the amount of damping you + + + align:start position:0% +adjust to get the amount of damping you +need + + align:start position:0% +need + + + align:start position:0% +need +okay so for a two degree Freedom + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +C1 here is Alpha M1 plus beta M beta + + align:start position:0% +C1 here is Alpha M1 plus beta M beta + + + align:start position:0% +C1 here is Alpha M1 plus beta M beta +K2 K K1 excuse me modal Mass Alpha time + + align:start position:0% +K2 K K1 excuse me modal Mass Alpha time + + + align:start position:0% +K2 K K1 excuse me modal Mass Alpha time +the modal Mass plus beta time the modal + + align:start position:0% +the modal Mass plus beta time the modal + + + align:start position:0% +the modal Mass plus beta time the modal +stiffness that's what you get for the + + align:start position:0% +stiffness that's what you get for the + + + align:start position:0% +stiffness that's what you get for the +first one and + + align:start position:0% +first one and + + + align:start position:0% +first one and +C2 is Alpha + + align:start position:0% +C2 is Alpha + + + align:start position:0% +C2 is Alpha +M2 plus beta + + align:start position:0% +M2 plus beta + + + align:start position:0% +M2 plus beta +K2 + + align:start position:0% + + + + align:start position:0% + +okay and the alphas and betas give you + + align:start position:0% +okay and the alphas and betas give you + + + align:start position:0% +okay and the alphas and betas give you +two free parameters you can play with + + align:start position:0% +two free parameters you can play with + + + align:start position:0% +two free parameters you can play with +and for a two degree Freedom system I + + align:start position:0% +and for a two degree Freedom system I + + + align:start position:0% +and for a two degree Freedom system I +can manipulate Alpha and beta to get the + + align:start position:0% +can manipulate Alpha and beta to get the + + + align:start position:0% +can manipulate Alpha and beta to get the +D in that I + + align:start position:0% +D in that I + + + align:start position:0% +D in that I +measure and I and I've forced my + + align:start position:0% +measure and I and I've forced my + + + align:start position:0% +measure and I and I've forced my +equations of motion to uncouple now + + align:start position:0% +equations of motion to uncouple now + + + align:start position:0% +equations of motion to uncouple now +Mother Nature may say that you know you + + align:start position:0% +Mother Nature may say that you know you + + + align:start position:0% +Mother Nature may say that you know you +know vand they don't + + align:start position:0% +know vand they don't + + + align:start position:0% +know vand they don't +uncouple and there's going to be a + + align:start position:0% +uncouple and there's going to be a + + + align:start position:0% +uncouple and there's going to be a +little cross talk between them but I say + + align:start position:0% +little cross talk between them but I say + + + align:start position:0% +little cross talk between them but I say +yeah but to first order I it's I'm going + + align:start position:0% +yeah but to first order I it's I'm going + + + align:start position:0% +yeah but to first order I it's I'm going +to get a pretty good model of the system + + align:start position:0% +to get a pretty good model of the system + + + align:start position:0% +to get a pretty good model of the system +so let's do that in this case let's uh + + align:start position:0% +so let's do that in this case let's uh + + + align:start position:0% +so let's do that in this case let's uh +maybe just to keep it I've got numbers + + align:start position:0% +maybe just to keep it I've got numbers + + + align:start position:0% +maybe just to keep it I've got numbers +here so let me find my notes so I don't + + align:start position:0% +here so let me find my notes so I don't + + + align:start position:0% +here so let me find my notes so I don't +get completely lost + + align:start position:0% +get completely lost + + + align:start position:0% +get completely lost +here so uh I don't want I'm going to + + align:start position:0% +here so uh I don't want I'm going to + + + align:start position:0% +here so uh I don't want I'm going to +just pick one for now I'm going to model + + align:start position:0% +just pick one for now I'm going to model + + + align:start position:0% +just pick one for now I'm going to model +my damping with just beta + + align:start position:0% + + + + align:start position:0% + +K beta time my diagonal stiffness Matrix + + align:start position:0% +K beta time my diagonal stiffness Matrix + + + align:start position:0% +K beta time my diagonal stiffness Matrix +and let's see + + align:start position:0% +and let's see + + + align:start position:0% +and let's see +let's see what happens + + align:start position:0% + + + + align:start position:0% + +here so that says my modal stamping is + + align:start position:0% +here so that says my modal stamping is + + + align:start position:0% +here so that says my modal stamping is +going to be some for mode one which be + + align:start position:0% +going to be some for mode one which be + + + align:start position:0% +going to be some for mode one which be +beta + + align:start position:0% +beta + + + align:start position:0% +beta +K1 now what's stamping ratio Zeta + + align:start position:0% +K1 now what's stamping ratio Zeta + + + align:start position:0% +K1 now what's stamping ratio Zeta +1 equals for a single degree Freedom + + align:start position:0% +1 equals for a single degree Freedom + + + align:start position:0% +1 equals for a single degree Freedom +system is the damping constant for the + + align:start position:0% +system is the damping constant for the + + + align:start position:0% +system is the damping constant for the +system over 2 Omega 1 m + + align:start position:0% +system over 2 Omega 1 m + + + align:start position:0% +system over 2 Omega 1 m +1 but that's going to be beta + + align:start position:0% +1 but that's going to be beta + + + align:start position:0% +1 but that's going to be beta +K1 over 2 Omega 1 + + align:start position:0% +K1 over 2 Omega 1 + + + align:start position:0% +K1 over 2 Omega 1 +M1 but M1 over K1 is Omega 1 + + align:start position:0% +M1 but M1 over K1 is Omega 1 + + + align:start position:0% +M1 but M1 over K1 is Omega 1 +s so I get an Omega 1 s in the + + align:start position:0% +s so I get an Omega 1 s in the + + + align:start position:0% +s so I get an Omega 1 s in the +numerator beta Omega 1^ 2ar over 2 + + align:start position:0% +numerator beta Omega 1^ 2ar over 2 + + + align:start position:0% +numerator beta Omega 1^ 2ar over 2 +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +1 remember the K over the M gave me the + + align:start position:0% +1 remember the K over the M gave me the + + + align:start position:0% +1 remember the K over the M gave me the +Omega 1 squ so the M's gone can cancel + + align:start position:0% +Omega 1 squ so the M's gone can cancel + + + align:start position:0% +Omega 1 squ so the M's gone can cancel +one of these this gives me beta Omega 1 + + align:start position:0% +one of these this gives me beta Omega 1 + + + align:start position:0% +one of these this gives me beta Omega 1 +over + + align:start position:0% + + + + align:start position:0% + +two so this now gives me a way of I can + + align:start position:0% +two so this now gives me a way of I can + + + align:start position:0% +two so this now gives me a way of I can +fit one of the + + align:start position:0% +fit one of the + + + align:start position:0% +fit one of the +dampings I can get exactly what I want + + align:start position:0% +dampings I can get exactly what I want + + + align:start position:0% +dampings I can get exactly what I want +say for mode one if I pick beta to be + + align:start position:0% +say for mode one if I pick beta to be + + + align:start position:0% +say for mode one if I pick beta to be +the right number okay so in this case + + align:start position:0% +the right number okay so in this case + + + align:start position:0% +the right number okay so in this case +I actually did did some + + align:start position:0% + + + + align:start position:0% + +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +pardon can't hear + + align:start position:0% +pardon can't hear + + + align:start position:0% +pardon can't hear +you + + align:start position:0% +you + + + align:start position:0% +you +no K1 over M1 is Omega 1 squ Omega 1 squ + + align:start position:0% +no K1 over M1 is Omega 1 squ Omega 1 squ + + + align:start position:0% +no K1 over M1 is Omega 1 squ Omega 1 squ +takes care of the M1 I get rid of one of + + align:start position:0% +takes care of the M1 I get rid of one of + + + align:start position:0% +takes care of the M1 I get rid of one of +the Omega 1es I'm left with + + align:start position:0% +the Omega 1es I'm left with + + + align:start position:0% +the Omega 1es I'm left with +this okay um + + align:start position:0% +this okay um + + + align:start position:0% +this okay um +okay so what if so let's just + + align:start position:0% +okay so what if so let's just + + + align:start position:0% +okay so what if so let's just +let beta equals + + align:start position:0% +let beta equals + + + align:start position:0% +let beta equals +01 and if you let beta equal to 01 then + + align:start position:0% +01 and if you let beta equal to 01 then + + + align:start position:0% +01 and if you let beta equal to 01 then +Zeta 1 = .01 Omega 1/ 2 we know Omega 1 + + align:start position:0% +Zeta 1 = .01 Omega 1/ 2 we know Omega 1 + + + align:start position:0% +Zeta 1 = .01 Omega 1/ 2 we know Omega 1 +is + + align:start position:0% +is + + + align:start position:0% +is +5.65 uh this when you work it out then + + align:start position:0% +5.65 uh this when you work it out then + + + align:start position:0% +5.65 uh this when you work it out then +gives you a number + + align:start position:0% +gives you a number + + + align:start position:0% +gives you a number +of + + align:start position:0% + + + + align:start position:0% + +0283 about + + align:start position:0% +0283 about + + + align:start position:0% +0283 about +3% and that would model + + align:start position:0% +3% and that would model + + + align:start position:0% +3% and that would model +uh that would say that this system when + + align:start position:0% +uh that would say that this system when + + + align:start position:0% +uh that would say that this system when +it vibrates in mode one it's going to + + align:start position:0% +it vibrates in mode one it's going to + + + align:start position:0% +it vibrates in mode one it's going to +damp out up to 50% in about three + + align:start position:0% +damp out up to 50% in about three + + + align:start position:0% +damp out up to 50% in about three +Cycles not bad approximations I'm just + + align:start position:0% +Cycles not bad approximations I'm just + + + align:start position:0% +Cycles not bad approximations I'm just +guessing about what it is that's a + + align:start position:0% +guessing about what it is that's a + + + align:start position:0% +guessing about what it is that's a +reasonable amount of damping for mode + + align:start position:0% +reasonable amount of damping for mode + + + align:start position:0% +reasonable amount of damping for mode +one now the problem is when I only use + + align:start position:0% +one now the problem is when I only use + + + align:start position:0% +one now the problem is when I only use +just beta K as my + + align:start position:0% +just beta K as my + + + align:start position:0% +just beta K as my +model now I'm stuck with whatever + + align:start position:0% +model now I'm stuck with whatever + + + align:start position:0% +model now I'm stuck with whatever +happens for mode two once I pick beta + + align:start position:0% +happens for mode two once I pick beta + + + align:start position:0% +happens for mode two once I pick beta +because Zeta + + align:start position:0% +because Zeta + + + align:start position:0% +because Zeta +2 is going to be beta Omega 2 over two + + align:start position:0% +2 is going to be beta Omega 2 over two + + + align:start position:0% +2 is going to be beta Omega 2 over two +and Omega 2 is quite a bit larger so + + align:start position:0% +and Omega 2 is quite a bit larger so + + + align:start position:0% +and Omega 2 is quite a bit larger so +that makes I'm stuck with a greater + + align:start position:0% +that makes I'm stuck with a greater + + + align:start position:0% +that makes I'm stuck with a greater +value for the second mode in this case + + align:start position:0% +value for the second mode in this case + + + align:start position:0% +value for the second mode in this case +it's + + align:start position:0% +it's + + + align:start position:0% +it's +uh + + align:start position:0% + + + + align:start position:0% + +0885 so if I just pick a one parameter + + align:start position:0% +0885 so if I just pick a one parameter + + + align:start position:0% +0885 so if I just pick a one parameter +model for my damping I'm I can make one + + align:start position:0% +model for my damping I'm I can make one + + + align:start position:0% +model for my damping I'm I can make one +perfect I can match it perfectly but + + align:start position:0% +perfect I can match it perfectly but + + + align:start position:0% +perfect I can match it perfectly but +then I'm stuck with whatever the other + + align:start position:0% +then I'm stuck with whatever the other + + + align:start position:0% +then I'm stuck with whatever the other +one is so I I did this because I could + + align:start position:0% +one is so I I did this because I could + + + align:start position:0% +one is so I I did this because I could +do it simply with one but if IID kept + + align:start position:0% +do it simply with one but if IID kept + + + align:start position:0% +do it simply with one but if IID kept +the + + align:start position:0% +the + + + align:start position:0% +the +full Model A two parameter model I could + + align:start position:0% +full Model A two parameter model I could + + + align:start position:0% +full Model A two parameter model I could +actually with manipulating both Alpha + + align:start position:0% +actually with manipulating both Alpha + + + align:start position:0% +actually with manipulating both Alpha +and beta I could actually model get both + + align:start position:0% +and beta I could actually model get both + + + align:start position:0% +and beta I could actually model get both +of the two measured dampings exactly + + align:start position:0% +of the two measured dampings exactly + + + align:start position:0% +of the two measured dampings exactly +right but if I have an N degree if I + + align:start position:0% +right but if I have an N degree if I + + + align:start position:0% +right but if I have an N degree if I +have three deegree Freedom system I only + + align:start position:0% +have three deegree Freedom system I only + + + align:start position:0% +have three deegree Freedom system I only +have two parameters I can fit two of the + + align:start position:0% +have two parameters I can fit two of the + + + align:start position:0% +have two parameters I can fit two of the +damping ratios but then I'm going to be + + align:start position:0% +damping ratios but then I'm going to be + + + align:start position:0% +damping ratios but then I'm going to be +stuck with whatever it gives me for the + + align:start position:0% +stuck with whatever it gives me for the + + + align:start position:0% +stuck with whatever it gives me for the +third but often times it's just one mode + + align:start position:0% +third but often times it's just one mode + + + align:start position:0% +third but often times it's just one mode +you really care about it's the problem + + align:start position:0% +you really care about it's the problem + + + align:start position:0% +you really care about it's the problem +mode you're at its natural frequency + + align:start position:0% +mode you're at its natural frequency + + + align:start position:0% +mode you're at its natural frequency +it's right going like crazy initi + + align:start position:0% +it's right going like crazy initi + + + align:start position:0% +it's right going like crazy initi +conditions make it vibrate a lot in that + + align:start position:0% +conditions make it vibrate a lot in that + + + align:start position:0% +conditions make it vibrate a lot in that +mode but this is what Ray damping allows + + align:start position:0% +mode but this is what Ray damping allows + + + align:start position:0% +mode but this is what Ray damping allows +you to do it all guarantees you that you + + align:start position:0% +you to do it all guarantees you that you + + + align:start position:0% +you to do it all guarantees you that you +will have a diagonal diagonalized set of + + align:start position:0% +will have a diagonal diagonalized set of + + + align:start position:0% +will have a diagonal diagonalized set of +equations of motion and it gives you two + + align:start position:0% +equations of motion and it gives you two + + + align:start position:0% +equations of motion and it gives you two +parameters that you can play with to fit + + align:start position:0% +parameters that you can play with to fit + + + align:start position:0% +parameters that you can play with to fit +the damping model however you + + align:start position:0% +the damping model however you + + + align:start position:0% +the damping model however you +want once you have + + align:start position:0% +want once you have + + + align:start position:0% +want once you have +damping now you have the complete + + align:start position:0% +damping now you have the complete + + + align:start position:0% +damping now you have the complete +solution for Decay from initial + + align:start position:0% + + + + align:start position:0% + +conditions and there's your two model + + align:start position:0% +conditions and there's your two model + + + align:start position:0% +conditions and there's your two model +you can solve for q1 transient Decay + + align:start position:0% +you can solve for q1 transient Decay + + + align:start position:0% +you can solve for q1 transient Decay +given initial conditions you can solve + + align:start position:0% +given initial conditions you can solve + + + align:start position:0% +given initial conditions you can solve +for Q2 transient decay of the second + + align:start position:0% +for Q2 transient decay of the second + + + align:start position:0% +for Q2 transient decay of the second +mode and then to to get back to the + + align:start position:0% +mode and then to to get back to the + + + align:start position:0% +mode and then to to get back to the +initial to the response in terms of your + + align:start position:0% +initial to the response in terms of your + + + align:start position:0% +initial to the response in terms of your +modal coordinates you just add the two + + align:start position:0% + + + + align:start position:0% + +together + + align:start position:0% + + + + align:start position:0% + +okay got some numbers here would are + + align:start position:0% +okay got some numbers here would are + + + align:start position:0% +okay got some numbers here would are +just instructive let's uh U inverse in + + align:start position:0% +just instructive let's uh U inverse in + + + align:start position:0% +just instructive let's uh U inverse in +order to get these initial conditions + + align:start position:0% +order to get these initial conditions + + + align:start position:0% +order to get these initial conditions +you got to know you inverse do we know + + align:start position:0% +you got to know you inverse do we know + + + align:start position:0% +you got to know you inverse do we know +you I gave us you here's our mode shape + + align:start position:0% +you I gave us you here's our mode shape + + + align:start position:0% +you I gave us you here's our mode shape +set of mod shape + + align:start position:0% +set of mod shape + + + align:start position:0% +set of mod shape +vectors and I'm run out of boards + + align:start position:0% + + + + align:start position:0% + +so we have the U Matrix we need U + + align:start position:0% +so we have the U Matrix we need U + + + align:start position:0% +so we have the U Matrix we need U +inverse so U inverse for this + + align:start position:0% + + + + align:start position:0% + +problem and we're going to quickly do + + align:start position:0% +problem and we're going to quickly do + + + align:start position:0% +problem and we're going to quickly do +some examples let's let + + align:start position:0% +some examples let's let + + + align:start position:0% +some examples let's let +uh + + align:start position:0% +uh + + + align:start position:0% +uh +V the V kns be zero no initial + + align:start position:0% +V the V kns be zero no initial + + + align:start position:0% +V the V kns be zero no initial +conditions on + + align:start position:0% +conditions on + + + align:start position:0% +conditions on +velocities and let's do + + align:start position:0% +velocities and let's do + + + align:start position:0% +velocities and let's do +X not the initial + + align:start position:0% +X not the initial + + + align:start position:0% +X not the initial +displacements + + align:start position:0% +displacements + + + align:start position:0% +displacements +be 1 and zero so the one and zero what + + align:start position:0% +be 1 and zero so the one and zero what + + + align:start position:0% +be 1 and zero so the one and zero what +we're saying is the bottom one doesn't + + align:start position:0% +we're saying is the bottom one doesn't + + + align:start position:0% +we're saying is the bottom one doesn't +move unit deflection here let go what + + align:start position:0% +move unit deflection here let go what + + + align:start position:0% +move unit deflection here let go what +you what are you going to get for the + + align:start position:0% +you what are you going to get for the + + + align:start position:0% +you what are you going to get for the +initial + + align:start position:0% +initial + + + align:start position:0% +initial +conditions X not equal 1 and z + + align:start position:0% +conditions X not equal 1 and z + + + align:start position:0% +conditions X not equal 1 and z +well that implies + + align:start position:0% +well that implies + + + align:start position:0% +well that implies +that the + + align:start position:0% + + + + align:start position:0% + +q's are going to be U inverse X + + align:start position:0% +q's are going to be U inverse X + + + align:start position:0% +q's are going to be U inverse X +knot so by the way this if this is true + + align:start position:0% +knot so by the way this if this is true + + + align:start position:0% +knot so by the way this if this is true +this implies that all Q do initial + + align:start position:0% +this implies that all Q do initial + + + align:start position:0% +this implies that all Q do initial +conditions + + align:start position:0% +conditions + + + align:start position:0% +conditions +equal zero right no initial velocities + + align:start position:0% +equal zero right no initial velocities + + + align:start position:0% +equal zero right no initial velocities +in generalized coordinates no initial + + align:start position:0% +in generalized coordinates no initial + + + align:start position:0% +in generalized coordinates no initial +velocities in modal coordinates but here + + align:start position:0% +velocities in modal coordinates but here + + + align:start position:0% +velocities in modal coordinates but here +we have but we are going to have an + + align:start position:0% +we have but we are going to have an + + + align:start position:0% +we have but we are going to have an +initial deflection and if I want to + + align:start position:0% +initial deflection and if I want to + + + align:start position:0% +initial deflection and if I want to +multip I want to then compute U + + align:start position:0% +multip I want to then compute U + + + align:start position:0% +multip I want to then compute U +inverse X knot and see what I + + align:start position:0% +inverse X knot and see what I + + + align:start position:0% +inverse X knot and see what I +get and what I get back when I do this + + align:start position:0% +get and what I get back when I do this + + + align:start position:0% +get and what I get back when I do this +one + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +9102 remember this is q1 not Q2 + + align:start position:0% +9102 remember this is q1 not Q2 + + + align:start position:0% +9102 remember this is q1 not Q2 +not so for that case it says I'm going + + align:start position:0% +not so for that case it says I'm going + + + align:start position:0% +not so for that case it says I'm going +to get 0.08 or 09 q1 equal to q1 and 0.9 + + align:start position:0% +to get 0.08 or 09 q1 equal to q1 and 0.9 + + + align:start position:0% +to get 0.08 or 09 q1 equal to q1 and 0.9 +of + + align:start position:0% +of + + + align:start position:0% +of +Q2 and my I go back over here to my + + align:start position:0% +Q2 and my I go back over here to my + + + align:start position:0% +Q2 and my I go back over here to my +transient DK there's no velocity so this + + align:start position:0% +transient DK there's no velocity so this + + + align:start position:0% +transient DK there's no velocity so this +basically going to look like + + align:start position:0% + + + + align:start position:0% + +q1 q1 KN cosine Omega DT eus th Omega t + + align:start position:0% +q1 q1 KN cosine Omega DT eus th Omega t + + + align:start position:0% +q1 q1 KN cosine Omega DT eus th Omega t +decaying + + align:start position:0% +decaying + + + align:start position:0% +decaying +cosine but for mode one its initial + + align:start position:0% +cosine but for mode one its initial + + + align:start position:0% +cosine but for mode one its initial +amplitudes you know less than 0.1 and + + align:start position:0% +amplitudes you know less than 0.1 and + + + align:start position:0% +amplitudes you know less than 0.1 and +mode two it's got a lot of mode two so + + align:start position:0% +mode two it's got a lot of mode two so + + + align:start position:0% +mode two it's got a lot of mode two so +it is what + + align:start position:0% +it is what + + + align:start position:0% +it is what +happens so unit deflection + + align:start position:0% +happens so unit deflection + + + align:start position:0% +happens so unit deflection +here in fact it's mostly mode two and if + + align:start position:0% +here in fact it's mostly mode two and if + + + align:start position:0% +here in fact it's mostly mode two and if +I just quickly I'll do one other X knot + + align:start position:0% +I just quickly I'll do one other X knot + + + align:start position:0% +I just quickly I'll do one other X knot +is + + align:start position:0% +is + + + align:start position:0% +is +01 that implies that Q + + align:start position:0% +01 that implies that Q + + + align:start position:0% +01 that implies that Q +uh + + align:start position:0% +uh + + + align:start position:0% +uh +q that you get from that + + align:start position:0% +q that you get from that + + + align:start position:0% +q that you get from that +is + + align:start position:0% +is + + + align:start position:0% +is +416 and + + align:start position:0% +416 and + + + align:start position:0% +416 and +minus + + align:start position:0% +minus + + + align:start position:0% +minus +4016 says you get about equal + + align:start position:0% +4016 says you get about equal + + + align:start position:0% +4016 says you get about equal +amounts so that's this one I don't move + + align:start position:0% +amounts so that's this one I don't move + + + align:start position:0% +amounts so that's this one I don't move +this one but I give this one a unit + + align:start position:0% +this one but I give this one a unit + + + align:start position:0% +this one but I give this one a unit +deflection let go I get about equal + + align:start position:0% +deflection let go I get about equal + + + align:start position:0% +deflection let go I get about equal +amounts of each one + + align:start position:0% +amounts of each one + + + align:start position:0% +amounts of each one +and of course I've told you the answer + + align:start position:0% +and of course I've told you the answer + + + align:start position:0% +and of course I've told you the answer +to this one is if I let x equal mode + + align:start position:0% +to this one is if I let x equal mode + + + align:start position:0% +to this one is if I let x equal mode +one's mode shape 1 and + + align:start position:0% +one's mode shape 1 and + + + align:start position:0% +one's mode shape 1 and +2.2 + + align:start position:0% +2.2 + + + align:start position:0% +2.2 +66 that implies that + + align:start position:0% +66 that implies that + + + align:start position:0% +66 that implies that +q1 equals 1 and Q2 when you multiply it + + align:start position:0% +q1 equals 1 and Q2 when you multiply it + + + align:start position:0% +q1 equals 1 and Q2 when you multiply it +out is zero so if I def it in the shape + + align:start position:0% +out is zero so if I def it in the shape + + + align:start position:0% +out is zero so if I def it in the shape +of mode one and I do U inverse X knot I + + align:start position:0% +of mode one and I do U inverse X knot I + + + align:start position:0% +of mode one and I do U inverse X knot I +will get back zero one and if I make + + align:start position:0% +will get back zero one and if I make + + + align:start position:0% +will get back zero one and if I make +this the shape of mode two I will get + + align:start position:0% +this the shape of mode two I will get + + + align:start position:0% +this the shape of mode two I will get +back zero for mode one and one for mode + + align:start position:0% + + + + align:start position:0% + +two so that will that's the run out of + + align:start position:0% +two so that will that's the run out of + + + align:start position:0% +two so that will that's the run out of +time but that's your intro to modal + + align:start position:0% +time but that's your intro to modal + + + align:start position:0% +time but that's your intro to modal +analysis so I think it's conceptually + + align:start position:0% +analysis so I think it's conceptually + + + align:start position:0% +analysis so I think it's conceptually +powerful + + align:start position:0% + + + + align:start position:0% + +oh is this one + + align:start position:0% +oh is this one + + + align:start position:0% +oh is this one +8 okay I may have written that + + align:start position:0% + + + + align:start position:0% + +down yeah I'll I'll double check that + + align:start position:0% +down yeah I'll I'll double check that + + + align:start position:0% +down yeah I'll I'll double check that +but yeah question why is + + align:start position:0% +but yeah question why is + + + align:start position:0% +but yeah question why is +it C to be only a function of beta + + align:start position:0% +it C to be only a function of beta + + + align:start position:0% +it C to be only a function of beta +because I wanted to get done by the end + + align:start position:0% +because I wanted to get done by the end + + + align:start position:0% +because I wanted to get done by the end +of the okay 60 you know 80 minutes I + + align:start position:0% +of the okay 60 you know 80 minutes I + + + align:start position:0% +of the okay 60 you know 80 minutes I +could have put both of them in + + align:start position:0% +could have put both of them in + + + align:start position:0% +could have put both of them in +manipulated both parameters these two + + align:start position:0% +manipulated both parameters these two + + + align:start position:0% +manipulated both parameters these two +equations and two unknowns two target + + align:start position:0% +equations and two unknowns two target + + + align:start position:0% +equations and two unknowns two target +values of damping I'd find an alpha and + + align:start position:0% +values of damping I'd find an alpha and + + + align:start position:0% +values of damping I'd find an alpha and +a beta that would make both work exactly + + align:start position:0% +a beta that would make both work exactly + + + align:start position:0% +a beta that would make both work exactly +right it actually just this one model is + + align:start position:0% +right it actually just this one model is + + + align:start position:0% +right it actually just this one model is +pretty good for this case the damping + + align:start position:0% +pretty good for this case the damping + + + align:start position:0% +pretty good for this case the damping +for second mode is greater than the + + align:start position:0% +for second mode is greater than the + + + align:start position:0% +for second mode is greater than the +first mode just happens to be this model + + align:start position:0% +first mode just happens to be this model + + + align:start position:0% +first mode just happens to be this model +is not bad right so you try see what + + align:start position:0% +is not bad right so you try see what + + + align:start position:0% +is not bad right so you try see what +gets best results yeah \ No newline at end of file diff --git a/PC3qooaF5Xs.txt b/PC3qooaF5Xs.txt new file mode 100644 index 0000000000000000000000000000000000000000..1a09b01c1a6fb1954f87c164e41ac0a060cb5194 --- /dev/null +++ b/PC3qooaF5Xs.txt @@ -0,0 +1,9195 @@ +align:start position:0% + +okay so let's continue our + + align:start position:0% +okay so let's continue our + + + align:start position:0% +okay so let's continue our +of welfare economics just to review + + align:start position:0% +of welfare economics just to review + + + align:start position:0% +of welfare economics just to review +where we are the first set of lectures + + align:start position:0% +where we are the first set of lectures + + + align:start position:0% +where we are the first set of lectures +in the course were about positive + + align:start position:0% +in the course were about positive + + + align:start position:0% +in the course were about positive +economics about understanding where + + align:start position:0% +economics about understanding where + + + align:start position:0% +economics about understanding where +supply and demand curves come from and + + align:start position:0% +supply and demand curves come from and + + + align:start position:0% +supply and demand curves come from and +what they mean now last lecture we + + align:start position:0% +what they mean now last lecture we + + + align:start position:0% +what they mean now last lecture we +turned from positive to normative + + align:start position:0% +turned from positive to normative + + + align:start position:0% +turned from positive to normative +economics and actually making judgments + + align:start position:0% +economics and actually making judgments + + + align:start position:0% +economics and actually making judgments +about whether things are good or bad and + + align:start position:0% +about whether things are good or bad and + + + align:start position:0% +about whether things are good or bad and +when choose the concept of welfare + + align:start position:0% +when choose the concept of welfare + + + align:start position:0% +when choose the concept of welfare +economic welfare or well-being and we + + align:start position:0% +economic welfare or well-being and we + + + align:start position:0% +economic welfare or well-being and we +talked about consumer surplus which is a + + align:start position:0% +talked about consumer surplus which is a + + + align:start position:0% +talked about consumer surplus which is a +measure of how well-off consumers are + + align:start position:0% +measure of how well-off consumers are + + + align:start position:0% +measure of how well-off consumers are +made by given exchange of goods and + + align:start position:0% +made by given exchange of goods and + + + align:start position:0% +made by given exchange of goods and +services and producer surplus how + + align:start position:0% +services and producer surplus how + + + align:start position:0% +services and producer surplus how +well-off police's are made we're going + + align:start position:0% +well-off police's are made we're going + + + align:start position:0% +well-off police's are made we're going +to start our lecture by proving what's + + align:start position:0% +to start our lecture by proving what's + + + align:start position:0% +to start our lecture by proving what's +modestly called the first fundamental + + align:start position:0% +modestly called the first fundamental + + + align:start position:0% +modestly called the first fundamental +theorem of welfare economics which is + + align:start position:0% +theorem of welfare economics which is + + + align:start position:0% +theorem of welfare economics which is +that competition maximizes welfare so + + align:start position:0% +that competition maximizes welfare so + + + align:start position:0% +that competition maximizes welfare so +this is basically taking our positive + + align:start position:0% +this is basically taking our positive + + + align:start position:0% +this is basically taking our positive +economics at a meeting our normative + + align:start position:0% +economics at a meeting our normative + + + align:start position:0% +economics at a meeting our normative +economics that is we are going to talk + + align:start position:0% +economics that is we are going to talk + + + align:start position:0% +economics that is we are going to talk +about how the model we've derived so far + + align:start position:0% +about how the model we've derived so far + + + align:start position:0% +about how the model we've derived so far +which is the equilibrium and a perfect + + align:start position:0% +which is the equilibrium and a perfect + + + align:start position:0% +which is the equilibrium and a perfect +competition happens to also be the + + align:start position:0% +competition happens to also be the + + + align:start position:0% +competition happens to also be the +outcome that delivers the maximum + + align:start position:0% +outcome that delivers the maximum + + + align:start position:0% +outcome that delivers the maximum +well-being to society let's step back + + align:start position:0% +well-being to society let's step back + + + align:start position:0% +well-being to society let's step back +well-being we called welfare how do we + + align:start position:0% +well-being we called welfare how do we + + + align:start position:0% +well-being we called welfare how do we +define the well-being of society well + + align:start position:0% +define the well-being of society well + + + align:start position:0% +define the well-being of society well +we're going to start with a simple + + align:start position:0% +we're going to start with a simple + + + align:start position:0% +we're going to start with a simple +definition which is we're gonna sadly + + align:start position:0% +definition which is we're gonna sadly + + + align:start position:0% +definition which is we're gonna sadly +say that social welfare social welfare + + align:start position:0% +say that social welfare social welfare + + + align:start position:0% +say that social welfare social welfare +is the total welfare of society is + + align:start position:0% +is the total welfare of society is + + + align:start position:0% +is the total welfare of society is +simply consumer surplus plus producer + + align:start position:0% +simply consumer surplus plus producer + + + align:start position:0% +simply consumer surplus plus producer +surplus that is we're not going to put + + align:start position:0% +surplus that is we're not going to put + + + align:start position:0% +surplus that is we're not going to put +any different weights we're not going to + + align:start position:0% +any different weights we're not going to + + + align:start position:0% +any different weights we're not going to +say we like somebody better than another + + align:start position:0% +say we like somebody better than another + + + align:start position:0% +say we like somebody better than another +which is because they look surplus is + + align:start position:0% +which is because they look surplus is + + + align:start position:0% +which is because they look surplus is +produced by a transaction and we just + + align:start position:0% +produced by a transaction and we just + + + align:start position:0% +produced by a transaction and we just +care about the total surplus that's + + align:start position:0% +care about the total surplus that's + + + align:start position:0% +care about the total surplus that's +produced and later we can come down via + + align:start position:0% +produced and later we can come down via + + + align:start position:0% +produced and later we can come down via +about consumers versus producers and we + + align:start position:0% +about consumers versus producers and we + + + align:start position:0% +about consumers versus producers and we +will but right now let's just say we + + align:start position:0% +will but right now let's just say we + + + align:start position:0% +will but right now let's just say we +care about the total surplus that's + + align:start position:0% +care about the total surplus that's + + + align:start position:0% +care about the total surplus that's +produced for society how much benefit is + + align:start position:0% +produced for society how much benefit is + + + align:start position:0% +produced for society how much benefit is +produced by this transaction ok well the + + align:start position:0% +produced by this transaction ok well the + + + align:start position:0% +produced by this transaction ok well the +benefits produced by this transaction is + + align:start position:0% +benefits produced by this transaction is + + + align:start position:0% +benefits produced by this transaction is +going to be the surplus derive surplus + + align:start position:0% +going to be the surplus derive surplus + + + align:start position:0% +going to be the surplus derive surplus +generated for consumers by that + + align:start position:0% +generated for consumers by that + + + align:start position:0% +generated for consumers by that +transaction and the surplus generated + + align:start position:0% +transaction and the surplus generated + + + align:start position:0% +transaction and the surplus generated +for producers by that transaction so our + + align:start position:0% +for producers by that transaction so our + + + align:start position:0% +for producers by that transaction so our +total measure of social well-being is + + align:start position:0% +total measure of social well-being is + + + align:start position:0% +total measure of social well-being is +going to be the sum of consumer and + + align:start position:0% +going to be the sum of consumer and + + + align:start position:0% +going to be the sum of consumer and +producer surplus and we are going to + + align:start position:0% +producer surplus and we are going to + + + align:start position:0% +producer surplus and we are going to +prove as I said we you don't need to + + align:start position:0% +prove as I said we you don't need to + + + align:start position:0% +prove as I said we you don't need to +know this but it's in graduating I was + + align:start position:0% +know this but it's in graduating I was + + + align:start position:0% +know this but it's in graduating I was +called the first fundamental theorem of + + align:start position:0% +called the first fundamental theorem of + + + align:start position:0% +called the first fundamental theorem of +welfare economics + + align:start position:0% +welfare economics + + + align:start position:0% +welfare economics +which is that under the assumptions + + align:start position:0% +which is that under the assumptions + + + align:start position:0% +which is that under the assumptions +we've made which are many okay under the + + align:start position:0% +we've made which are many okay under the + + + align:start position:0% +we've made which are many okay under the +assumptions we've made the competitive + + align:start position:0% +assumptions we've made the competitive + + + align:start position:0% +assumptions we've made the competitive +equilibrium where supply equals demand + + align:start position:0% +equilibrium where supply equals demand + + + align:start position:0% +equilibrium where supply equals demand +is the point that maximizes social + + align:start position:0% +is the point that maximizes social + + + align:start position:0% +is the point that maximizes social +welfare that is the key insight is the + + align:start position:0% +welfare that is the key insight is the + + + align:start position:0% +welfare that is the key insight is the +point that the market naturally delivers + + align:start position:0% +point that the market naturally delivers + + + align:start position:0% +point that the market naturally delivers +the equilibrium that's gained by the + + align:start position:0% +the equilibrium that's gained by the + + + align:start position:0% +the equilibrium that's gained by the +market naturally happens to be the point + + align:start position:0% +market naturally happens to be the point + + + align:start position:0% +market naturally happens to be the point +that also makes society as well off as + + align:start position:0% +that also makes society as well off as + + + align:start position:0% +that also makes society as well off as +possible a very profound result okay + + align:start position:0% +possible a very profound result okay + + + align:start position:0% +possible a very profound result okay +that is a positive conclusion which is + + align:start position:0% +that is a positive conclusion which is + + + align:start position:0% +that is a positive conclusion which is +that supplying a man will meet at a + + align:start position:0% +that supplying a man will meet at a + + + align:start position:0% +that supplying a man will meet at a +certain equilibrium delivers a normative + + align:start position:0% +certain equilibrium delivers a normative + + + align:start position:0% +certain equilibrium delivers a normative +conclusion which is that equilibrium is + + align:start position:0% +conclusion which is that equilibrium is + + + align:start position:0% +conclusion which is that equilibrium is +the point which maximizes social welfare + + align:start position:0% +the point which maximizes social welfare + + + align:start position:0% +the point which maximizes social welfare +okay now the best way to see this is + + align:start position:0% +okay now the best way to see this is + + + align:start position:0% +okay now the best way to see this is +just graphically so let's go to figure + + align:start position:0% +just graphically so let's go to figure + + + align:start position:0% +just graphically so let's go to figure +10:1 okay figure ten one has supply and + + align:start position:0% +10:1 okay figure ten one has supply and + + + align:start position:0% +10:1 okay figure ten one has supply and +demand curve okay once again whether + + align:start position:0% +demand curve okay once again whether + + + align:start position:0% +demand curve okay once again whether +these are curved or linear these are + + align:start position:0% +these are curved or linear these are + + + align:start position:0% +these are curved or linear these are +just you know it's still the basic idea + + align:start position:0% +just you know it's still the basic idea + + + align:start position:0% +just you know it's still the basic idea +of supply and demand curve so a curve + + align:start position:0% +of supply and demand curve so a curve + + + align:start position:0% +of supply and demand curve so a curve +supplying a main curve are things which + + align:start position:0% +supplying a main curve are things which + + + align:start position:0% +supplying a main curve are things which +more are more sort of constant + + align:start position:0% +more are more sort of constant + + + align:start position:0% +more are more sort of constant +elasticity type curves but that doesn't + + align:start position:0% +elasticity type curves but that doesn't + + + align:start position:0% +elasticity type curves but that doesn't +really affect the intuition okay we have + + align:start position:0% +really affect the intuition okay we have + + + align:start position:0% +really affect the intuition okay we have +here the triangles of consumer surplus + + align:start position:0% +here the triangles of consumer surplus + + + align:start position:0% +here the triangles of consumer surplus +and producer surplus so consumer surplus + + align:start position:0% +and producer surplus so consumer surplus + + + align:start position:0% +and producer surplus so consumer surplus +give me the letter somebody raise their + + align:start position:0% +give me the letter somebody raise their + + + align:start position:0% +give me the letter somebody raise their +hand and tell me which letters on this + + align:start position:0% +hand and tell me which letters on this + + + align:start position:0% +hand and tell me which letters on this +diagram correspond to consumer surplus + + align:start position:0% +diagram correspond to consumer surplus + + + align:start position:0% +diagram correspond to consumer surplus +and Y which which areas denoted by which + + align:start position:0% +and Y which which areas denoted by which + + + align:start position:0% +and Y which which areas denoted by which +letters correspond to consumer surplus + + align:start position:0% +letters correspond to consumer surplus + + + align:start position:0% +letters correspond to consumer surplus +and why yeah why is that + + align:start position:0% + + + + align:start position:0% + +exactly everything above below the + + align:start position:0% +exactly everything above below the + + + align:start position:0% +exactly everything above below the +demand curve above the price consumer + + align:start position:0% +demand curve above the price consumer + + + align:start position:0% +demand curve above the price consumer +surplus so R plus V so therefore what's + + align:start position:0% +surplus so R plus V so therefore what's + + + align:start position:0% +surplus so R plus V so therefore what's +producer surplus same person s plus T + + align:start position:0% +producer surplus same person s plus T + + + align:start position:0% +producer surplus same person s plus T +plus U is producer surplus so consumer + + align:start position:0% +plus U is producer surplus so consumer + + + align:start position:0% +plus U is producer surplus so consumer +surplus R plus V producer surplus is s + + align:start position:0% +surplus R plus V producer surplus is s + + + align:start position:0% +surplus R plus V producer surplus is s +plus t plus u okay you can see those of + + align:start position:0% +plus t plus u okay you can see those of + + + align:start position:0% +plus t plus u okay you can see those of +you are sort of graphically oriented can + + align:start position:0% +you are sort of graphically oriented can + + + align:start position:0% +you are sort of graphically oriented can +immediately see the sum of those two + + align:start position:0% +immediately see the sum of those two + + + align:start position:0% +immediately see the sum of those two +triangles will be maximized at the + + align:start position:0% +triangles will be maximized at the + + + align:start position:0% +triangles will be maximized at the +intersection of the curves and nowhere + + align:start position:0% +intersection of the curves and nowhere + + + align:start position:0% +intersection of the curves and nowhere +else okay so for example let's think + + align:start position:0% +else okay so for example let's think + + + align:start position:0% +else okay so for example let's think +about the case where I say well look + + align:start position:0% +about the case where I say well look + + + align:start position:0% +about the case where I say well look +it's a shame the prices that high we + + align:start position:0% +it's a shame the prices that high we + + + align:start position:0% +it's a shame the prices that high we +ought to make the price lower let's set + + align:start position:0% +ought to make the price lower let's set + + + align:start position:0% +ought to make the price lower let's set +a new price let's have the government + + align:start position:0% +a new price let's have the government + + + align:start position:0% +a new price let's have the government +mandate a new price at p2 suppose the + + align:start position:0% +mandate a new price at p2 suppose the + + + align:start position:0% +mandate a new price at p2 suppose the +government intervenes and since we're + + align:start position:0% +government intervenes and since we're + + + align:start position:0% +government intervenes and since we're +gonna set a price ceiling we're gonna + + align:start position:0% +gonna set a price ceiling we're gonna + + + align:start position:0% +gonna set a price ceiling we're gonna +say no one can charge more than p2 for + + align:start position:0% +say no one can charge more than p2 for + + + align:start position:0% +say no one can charge more than p2 for +their product and won't that be a good + + align:start position:0% +their product and won't that be a good + + + align:start position:0% +their product and won't that be a good +thing because consumers ould be better + + align:start position:0% +thing because consumers ould be better + + + align:start position:0% +thing because consumers ould be better +off they'll pay lower prices well what + + align:start position:0% +off they'll pay lower prices well what + + + align:start position:0% +off they'll pay lower prices well what +does that do that does what does that do + + align:start position:0% +does that do that does what does that do + + + align:start position:0% +does that do that does what does that do +to consumer surplus + + align:start position:0% +to consumer surplus + + + align:start position:0% +to consumer surplus +well consumer surplus used to be R plus + + align:start position:0% +well consumer surplus used to be R plus + + + align:start position:0% +well consumer surplus used to be R plus +V it instead becomes R plus s which is + + align:start position:0% +V it instead becomes R plus s which is + + + align:start position:0% +V it instead becomes R plus s which is +bigger + + align:start position:0% +bigger + + + align:start position:0% +bigger +okay consumer surplus Rises you lose the + + align:start position:0% +okay consumer surplus Rises you lose the + + + align:start position:0% +okay consumer surplus Rises you lose the +triangle V and you gain the and you gain + + align:start position:0% +triangle V and you gain the and you gain + + + align:start position:0% +triangle V and you gain the and you gain +the rectangle S but the key point is at + + align:start position:0% +the rectangle S but the key point is at + + + align:start position:0% +the rectangle S but the key point is at +the price e to okay at the price P to + + align:start position:0% +the price e to okay at the price P to + + + align:start position:0% +the price e to okay at the price P to +yet that becomes the new consumer + + align:start position:0% +yet that becomes the new consumer + + + align:start position:0% +yet that becomes the new consumer +surplus the new producer surplus is what + + align:start position:0% +surplus the new producer surplus is what + + + align:start position:0% +surplus the new producer surplus is what +at that price p2 what's the new producer + + align:start position:0% +at that price p2 what's the new producer + + + align:start position:0% +at that price p2 what's the new producer +surplus so raise their hand and tell me + + align:start position:0% +surplus so raise their hand and tell me + + + align:start position:0% +surplus so raise their hand and tell me +yeah it's T it drops to t producers just + + align:start position:0% +yeah it's T it drops to t producers just + + + align:start position:0% +yeah it's T it drops to t producers just +get below the price above the supply + + align:start position:0% +get below the price above the supply + + + align:start position:0% +get below the price above the supply +curve so what has happened to total + + align:start position:0% +curve so what has happened to total + + + align:start position:0% +curve so what has happened to total +social welfare it has fallen by the + + align:start position:0% +social welfare it has fallen by the + + + align:start position:0% +social welfare it has fallen by the +amount V Plus u total social welfare has + + align:start position:0% +amount V Plus u total social welfare has + + + align:start position:0% +amount V Plus u total social welfare has +fallen play deepest V Plus u so in some + + align:start position:0% +fallen play deepest V Plus u so in some + + + align:start position:0% +fallen play deepest V Plus u so in some +sense two things have happened here + + align:start position:0% +sense two things have happened here + + + align:start position:0% +sense two things have happened here +we've set this price the first is a + + align:start position:0% +we've set this price the first is a + + + align:start position:0% +we've set this price the first is a +transfer we have transferred the + + align:start position:0% +transfer we have transferred the + + + align:start position:0% +transfer we have transferred the +rectangle s from producers to consumers + + align:start position:0% +rectangle s from producers to consumers + + + align:start position:0% +rectangle s from producers to consumers +s used to be part of producer surplus + + align:start position:0% +s used to be part of producer surplus + + + align:start position:0% +s used to be part of producer surplus +we're not giving it to consumers first + + align:start position:0% +we're not giving it to consumers first + + + align:start position:0% +we're not giving it to consumers first +thing that happens is a transfer that + + align:start position:0% +thing that happens is a transfer that + + + align:start position:0% +thing that happens is a transfer that +was probably the idea of this policy + + align:start position:0% +was probably the idea of this policy + + + align:start position:0% +was probably the idea of this policy +make consumers better off so who + + align:start position:0% +make consumers better off so who + + + align:start position:0% +make consumers better off so who +transferred what you see pretty surplus + + align:start position:0% +transferred what you see pretty surplus + + + align:start position:0% +transferred what you see pretty surplus +to consumers that's the rectangle s + + align:start position:0% +to consumers that's the rectangle s + + + align:start position:0% +to consumers that's the rectangle s +that's the first thing this happened so + + align:start position:0% +that's the first thing this happened so + + + align:start position:0% +that's the first thing this happened so +thing one this happened is a transfer of + + align:start position:0% +thing one this happened is a transfer of + + + align:start position:0% +thing one this happened is a transfer of +s but the second thing that's happened + + align:start position:0% +s but the second thing that's happened + + + align:start position:0% +s but the second thing that's happened +is we have created what we call a + + align:start position:0% +is we have created what we call a + + + align:start position:0% +is we have created what we call a +deadweight loss of U plus V a deadweight + + align:start position:0% +deadweight loss of U plus V a deadweight + + + align:start position:0% +deadweight loss of U plus V a deadweight +loss of U plus V dwl deadweight loss + + align:start position:0% +loss of U plus V dwl deadweight loss + + + align:start position:0% +loss of U plus V dwl deadweight loss +what does the deadweight loss that is + + align:start position:0% +what does the deadweight loss that is + + + align:start position:0% +what does the deadweight loss that is +the net reduction in welfare from trades + + align:start position:0% +the net reduction in welfare from trades + + + align:start position:0% +the net reduction in welfare from trades +that are not made the deadweight loss is + + align:start position:0% +that are not made the deadweight loss is + + + align:start position:0% +that are not made the deadweight loss is +a key concept we'll come back to I'll + + align:start position:0% +a key concept we'll come back to I'll + + + align:start position:0% +a key concept we'll come back to I'll +expect you to know it in your sleep okay + + align:start position:0% +expect you to know it in your sleep okay + + + align:start position:0% +expect you to know it in your sleep okay +is that deadweight loss is the net + + align:start position:0% +is that deadweight loss is the net + + + align:start position:0% +is that deadweight loss is the net +reduction in Social Welfare from trades + + align:start position:0% +reduction in Social Welfare from trades + + + align:start position:0% +reduction in Social Welfare from trades +that are not made the intuition here is + + align:start position:0% +that are not made the intuition here is + + + align:start position:0% +that are not made the intuition here is +that every trade that makes at least one + + align:start position:0% +that every trade that makes at least one + + + align:start position:0% +that every trade that makes at least one +party better off without making the + + align:start position:0% +party better off without making the + + + align:start position:0% +party better off without making the +other party worse off is a good trade to + + align:start position:0% +other party worse off is a good trade to + + + align:start position:0% +other party worse off is a good trade to +do under the assumption we made so far + + align:start position:0% +do under the assumption we made so far + + + align:start position:0% +do under the assumption we made so far +if you ever trade that increased + + align:start position:0% +if you ever trade that increased + + + align:start position:0% +if you ever trade that increased +consumer surplus or produce surplus or + + align:start position:0% +consumer surplus or produce surplus or + + + align:start position:0% +consumer surplus or produce surplus or +both that's a good thing to have right + + align:start position:0% +both that's a good thing to have right + + + align:start position:0% +both that's a good thing to have right +if my daughter has any song she wants to + + align:start position:0% +if my daughter has any song she wants to + + + align:start position:0% +if my daughter has any song she wants to +buy by Kendrick Lamar that you guys have + + align:start position:0% +buy by Kendrick Lamar that you guys have + + + align:start position:0% +buy by Kendrick Lamar that you guys have +more than a dollar she gets him for a + + align:start position:0% +more than a dollar she gets him for a + + + align:start position:0% +more than a dollar she gets him for a +dollar anything which stops her from + + align:start position:0% +dollar anything which stops her from + + + align:start position:0% +dollar anything which stops her from +buying those songs is bad she's losing + + align:start position:0% +buying those songs is bad she's losing + + + align:start position:0% +buying those songs is bad she's losing +surplus okay so basically the key point + + align:start position:0% +surplus okay so basically the key point + + + align:start position:0% +surplus okay so basically the key point +is that deadweight loss is an + + align:start position:0% +is that deadweight loss is an + + + align:start position:0% +is that deadweight loss is an +inefficiency okay we talked about how + + align:start position:0% +inefficiency okay we talked about how + + + align:start position:0% +inefficiency okay we talked about how +competition leads to maximally efficient + + align:start position:0% +competition leads to maximally efficient + + + align:start position:0% +competition leads to maximally efficient +production through cost minimization + + align:start position:0% +production through cost minimization + + + align:start position:0% +production through cost minimization +competition also leads to the maximum + + align:start position:0% +competition also leads to the maximum + + + align:start position:0% +competition also leads to the maximum +welfare outcome because that point is + + align:start position:0% +welfare outcome because that point is + + + align:start position:0% +welfare outcome because that point is +the point which makes society best off + + align:start position:0% +the point which makes society best off + + + align:start position:0% +the point which makes society best off +defined as the sum of consumer surplus + + align:start position:0% +defined as the sum of consumer surplus + + + align:start position:0% +defined as the sum of consumer surplus +plus producer surplus + + align:start position:0% +plus producer surplus + + + align:start position:0% +plus producer surplus +okay but once again I cannot highlight + + align:start position:0% +okay but once again I cannot highlight + + + align:start position:0% +okay but once again I cannot highlight +enough the depth of this insight at this + + align:start position:0% +enough the depth of this insight at this + + + align:start position:0% +enough the depth of this insight at this +point which before today you knew as the + + align:start position:0% +point which before today you knew as the + + + align:start position:0% +point which before today you knew as the +outcome I showed him the first lecture + + align:start position:0% +outcome I showed him the first lecture + + + align:start position:0% +outcome I showed him the first lecture +this what happens we have supply and + + align:start position:0% +this what happens we have supply and + + + align:start position:0% +this what happens we have supply and +demand you get to this equilibrium that + + align:start position:0% +demand you get to this equilibrium that + + + align:start position:0% +demand you get to this equilibrium that +happens to be the very best place to be + + align:start position:0% +happens to be the very best place to be + + + align:start position:0% +happens to be the very best place to be +and that's why we call it the first + + align:start position:0% +and that's why we call it the first + + + align:start position:0% +and that's why we call it the first +fundamental theorem it's very important + + align:start position:0% +fundamental theorem it's very important + + + align:start position:0% +fundamental theorem it's very important +okay yeah so so so let's I want to come + + align:start position:0% +okay yeah so so so let's I want to come + + + align:start position:0% +okay yeah so so so let's I want to come +to that let's talk about that let's go + + align:start position:0% +to that let's talk about that let's go + + + align:start position:0% +to that let's talk about that let's go +to another example to talk about that + + align:start position:0% +to another example to talk about that + + + align:start position:0% +to another example to talk about that +let's talk about interventions let's do + + align:start position:0% +let's talk about interventions let's do + + + align:start position:0% +let's talk about interventions let's do +it let's do it let's do an example let + + align:start position:0% +it let's do it let's do an example let + + + align:start position:0% +it let's do it let's do an example let +that was just sort of to teach you the + + align:start position:0% +that was just sort of to teach you the + + + align:start position:0% +that was just sort of to teach you the +basic idea but let's go on to more + + align:start position:0% +basic idea but let's go on to more + + + align:start position:0% +basic idea but let's go on to more +explicit example of a government + + align:start position:0% +explicit example of a government + + + align:start position:0% +explicit example of a government +intervention actually do it here let me + + align:start position:0% +intervention actually do it here let me + + + align:start position:0% +intervention actually do it here let me +do explicit example of a government + + align:start position:0% +do explicit example of a government + + + align:start position:0% +do explicit example of a government +intervention that will and that will + + align:start position:0% +intervention that will and that will + + + align:start position:0% +intervention that will and that will +address the question was just asked + + align:start position:0% +address the question was just asked + + + align:start position:0% +address the question was just asked +because I skipped over sort of a key + + align:start position:0% +because I skipped over sort of a key + + + align:start position:0% +because I skipped over sort of a key +point here that that I'm always I'm + + align:start position:0% +point here that that I'm always I'm + + + align:start position:0% +point here that that I'm always I'm +always not sure whether way order to + + align:start position:0% +always not sure whether way order to + + + align:start position:0% +always not sure whether way order to +teach you things so so let's ask let's + + align:start position:0% +teach you things so so let's ask let's + + + align:start position:0% +teach you things so so let's ask let's +take an example of a market let's + + align:start position:0% +take an example of a market let's + + + align:start position:0% +take an example of a market let's +consider the market for gas so go to + + align:start position:0% +consider the market for gas so go to + + + align:start position:0% +consider the market for gas so go to +figure 10 to this heart we talked about + + align:start position:0% +figure 10 to this heart we talked about + + + align:start position:0% +figure 10 to this heart we talked about +before the market for gas + + align:start position:0% +before the market for gas + + + align:start position:0% +before the market for gas +imagine the market for gas is initially + + align:start position:0% +imagine the market for gas is initially + + + align:start position:0% +imagine the market for gas is initially +in equilibrium with supply curve s1 and + + align:start position:0% +in equilibrium with supply curve s1 and + + + align:start position:0% +in equilibrium with supply curve s1 and +a demand curve D it's initially in + + align:start position:0% +a demand curve D it's initially in + + + align:start position:0% +a demand curve D it's initially in +equilibrium at Point little E one with + + align:start position:0% +equilibrium at Point little E one with + + + align:start position:0% +equilibrium at Point little E one with +q1 gallons of gas being sold at a price + + align:start position:0% +q1 gallons of gas being sold at a price + + + align:start position:0% +q1 gallons of gas being sold at a price +p1 that's the initial equilibrium now + + align:start position:0% +p1 that's the initial equilibrium now + + + align:start position:0% +p1 that's the initial equilibrium now +imagine that there is an oil crisis + + align:start position:0% +imagine that there is an oil crisis + + + align:start position:0% +imagine that there is an oil crisis +because for example low company cited be + + align:start position:0% +because for example low company cited be + + + align:start position:0% +because for example low company cited be +good idea to drill 8 miles underground + + align:start position:0% +good idea to drill 8 miles underground + + + align:start position:0% +good idea to drill 8 miles underground +horizontally and the busts and their + + align:start position:0% +horizontally and the busts and their + + + align:start position:0% +horizontally and the busts and their +spills everywhere something like that + + align:start position:0% +spills everywhere something like that + + + align:start position:0% +spills everywhere something like that +some random example like that ok and + + align:start position:0% +some random example like that ok and + + + align:start position:0% +some random example like that ok and +this was a supply crisis what happens + + align:start position:0% +this was a supply crisis what happens + + + align:start position:0% +this was a supply crisis what happens +now is suddenly it gets more expensive + + align:start position:0% +now is suddenly it gets more expensive + + + align:start position:0% +now is suddenly it gets more expensive +to produce gas so the supply curve + + align:start position:0% +to produce gas so the supply curve + + + align:start position:0% +to produce gas so the supply curve +shifts upwards we talked about this last + + align:start position:0% +shifts upwards we talked about this last + + + align:start position:0% +shifts upwards we talked about this last +time leading us to new equilibrium at + + align:start position:0% +time leading us to new equilibrium at + + + align:start position:0% +time leading us to new equilibrium at +Point E - and your we talked about the + + align:start position:0% +Point E - and your we talked about the + + + align:start position:0% +Point E - and your we talked about the +echolert mork's firt initially there if + + align:start position:0% +echolert mork's firt initially there if + + + align:start position:0% +echolert mork's firt initially there if +we think about in steps initially you've + + align:start position:0% +we think about in steps initially you've + + + align:start position:0% +we think about in steps initially you've +created an excess demand because gas + + align:start position:0% +created an excess demand because gas + + + align:start position:0% +created an excess demand because gas +companies no longer want to supply + + align:start position:0% +companies no longer want to supply + + + align:start position:0% +companies no longer want to supply +q1 Gallants at a price p1 from their new + + align:start position:0% +q1 Gallants at a price p1 from their new + + + align:start position:0% +q1 Gallants at a price p1 from their new +supply curve so you move you shift along + + align:start position:0% +supply curve so you move you shift along + + + align:start position:0% +supply curve so you move you shift along +the demand curve to the new point e 2 + + align:start position:0% +the demand curve to the new point e 2 + + + align:start position:0% +the demand curve to the new point e 2 +which is new equilibrium and all's well + + align:start position:0% +which is new equilibrium and all's well + + + align:start position:0% +which is new equilibrium and all's well +and good + + align:start position:0% +and good + + + align:start position:0% +and good +okay prices go up that's what happened + + align:start position:0% +okay prices go up that's what happened + + + align:start position:0% +okay prices go up that's what happened +after deepwater and things like that + + align:start position:0% +after deepwater and things like that + + + align:start position:0% +after deepwater and things like that +okay now imagine the government doesn't + + align:start position:0% +okay now imagine the government doesn't + + + align:start position:0% +okay now imagine the government doesn't +like that magic government says well we + + align:start position:0% +like that magic government says well we + + + align:start position:0% +like that magic government says well we +don't like that we don't like the fact + + align:start position:0% +don't like that we don't like the fact + + + align:start position:0% +don't like that we don't like the fact +consumer is a table for gas consumers + + align:start position:0% +consumer is a table for gas consumers + + + align:start position:0% +consumer is a table for gas consumers +vote us out of office we'll have to pay + + align:start position:0% +vote us out of office we'll have to pay + + + align:start position:0% +vote us out of office we'll have to pay +more for gas so we are gonna solve this + + align:start position:0% +more for gas so we are gonna solve this + + + align:start position:0% +more for gas so we are gonna solve this +by imposing a price ceiling we're gonna + + align:start position:0% +by imposing a price ceiling we're gonna + + + align:start position:0% +by imposing a price ceiling we're gonna +announce the price of gas must remain at + + align:start position:0% +announce the price of gas must remain at + + + align:start position:0% +announce the price of gas must remain at +its old level p1 okay + + align:start position:0% +its old level p1 okay + + + align:start position:0% +its old level p1 okay +so let's go to figure 10 three figure 10 + + align:start position:0% +so let's go to figure 10 three figure 10 + + + align:start position:0% +so let's go to figure 10 three figure 10 +three shows what happens when the + + align:start position:0% +three shows what happens when the + + + align:start position:0% +three shows what happens when the +government imposed that price ceiling + + align:start position:0% +government imposed that price ceiling + + + align:start position:0% +government imposed that price ceiling +okay well the first question is if the + + align:start position:0% +okay well the first question is if the + + + align:start position:0% +okay well the first question is if the +government imposed a price ceiling of p1 + + align:start position:0% +government imposed a price ceiling of p1 + + + align:start position:0% +government imposed a price ceiling of p1 +how much actually gets sold in the + + align:start position:0% +how much actually gets sold in the + + + align:start position:0% +how much actually gets sold in the +market this comes the question was just + + align:start position:0% +market this comes the question was just + + + align:start position:0% +market this comes the question was just +asked well this is sort of a new thing + + align:start position:0% +asked well this is sort of a new thing + + + align:start position:0% +asked well this is sort of a new thing +this sort of a new thing we've looked at + + align:start position:0% +this sort of a new thing we've looked at + + + align:start position:0% +this sort of a new thing we've looked at +which is we have the situation was + + align:start position:0% +which is we have the situation was + + + align:start position:0% +which is we have the situation was +excess demand at the price p1 could + + align:start position:0% +excess demand at the price p1 could + + + align:start position:0% +excess demand at the price p1 could +sumers still want Q little deep but + + align:start position:0% +sumers still want Q little deep but + + + align:start position:0% +sumers still want Q little deep but +suppliers are only willing to supply Q s + + align:start position:0% +suppliers are only willing to supply Q s + + + align:start position:0% +suppliers are only willing to supply Q s +cute little s see consumers still are + + align:start position:0% +cute little s see consumers still are + + + align:start position:0% +cute little s see consumers still are +working off the same demand curve if + + align:start position:0% +working off the same demand curve if + + + align:start position:0% +working off the same demand curve if +used the government says we still want + + align:start position:0% +used the government says we still want + + + align:start position:0% +used the government says we still want +the price to be p1 they're like great we + + align:start position:0% +the price to be p1 they're like great we + + + align:start position:0% +the price to be p1 they're like great we +someone as much gas we had before + + align:start position:0% +someone as much gas we had before + + + align:start position:0% +someone as much gas we had before +suppliers are like no way we're not + + align:start position:0% +suppliers are like no way we're not + + + align:start position:0% +suppliers are like no way we're not +going to supply it if you're gonna keep + + align:start position:0% +going to supply it if you're gonna keep + + + align:start position:0% +going to supply it if you're gonna keep +the price at that level we're gonna + + align:start position:0% +the price at that level we're gonna + + + align:start position:0% +the price at that level we're gonna +produce less gas because we haven't + + align:start position:0% +produce less gas because we haven't + + + align:start position:0% +produce less gas because we haven't +rising marginal cost so if you're gonna + + align:start position:0% +rising marginal cost so if you're gonna + + + align:start position:0% +rising marginal cost so if you're gonna +force have that same price we're gonna + + align:start position:0% +force have that same price we're gonna + + + align:start position:0% +force have that same price we're gonna +work our way back down the supply curve + + align:start position:0% +work our way back down the supply curve + + + align:start position:0% +work our way back down the supply curve +and produce less gas so suddenly you + + align:start position:0% +and produce less gas so suddenly you + + + align:start position:0% +and produce less gas so suddenly you +have a situation of excess demand that + + align:start position:0% +have a situation of excess demand that + + + align:start position:0% +have a situation of excess demand that +doesn't get resolved remember the last + + align:start position:0% +doesn't get resolved remember the last + + + align:start position:0% +doesn't get resolved remember the last +time I said excess demand I resolved by + + align:start position:0% +time I said excess demand I resolved by + + + align:start position:0% +time I said excess demand I resolved by +moving up the demand curve well you + + align:start position:0% +moving up the demand curve well you + + + align:start position:0% +moving up the demand curve well you +can't hear you can't resolve that + + align:start position:0% +can't hear you can't resolve that + + + align:start position:0% +can't hear you can't resolve that +because the price is forced to be a p1 + + align:start position:0% +because the price is forced to be a p1 + + + align:start position:0% +because the price is forced to be a p1 +ok now what determines what actually + + align:start position:0% +ok now what determines what actually + + + align:start position:0% +ok now what determines what actually +gets sold ones a price restriction + + align:start position:0% +gets sold ones a price restriction + + + align:start position:0% +gets sold ones a price restriction +here's the way I like to think of it I + + align:start position:0% +here's the way I like to think of it I + + + align:start position:0% +here's the way I like to think of it I +like to think of the actual quantity + + align:start position:0% +like to think of the actual quantity + + + align:start position:0% +like to think of the actual quantity +gets set by the constrained party so in + + align:start position:0% +gets set by the constrained party so in + + + align:start position:0% +gets set by the constrained party so in +this case a price ceiling means that + + align:start position:0% +this case a price ceiling means that + + + align:start position:0% +this case a price ceiling means that +suppliers want our ask supply more than + + align:start position:0% +suppliers want our ask supply more than + + + align:start position:0% +suppliers want our ask supply more than +they're willing to so they just say no + + align:start position:0% +they're willing to so they just say no + + + align:start position:0% +they're willing to so they just say no +so you actually get the ultimate quality + + align:start position:0% +so you actually get the ultimate quality + + + align:start position:0% +so you actually get the ultimate quality +in the market is qsr it doesn't matter + + align:start position:0% +in the market is qsr it doesn't matter + + + align:start position:0% +in the market is qsr it doesn't matter +that demand is yqd they can't buy stuff + + align:start position:0% +that demand is yqd they can't buy stuff + + + align:start position:0% +that demand is yqd they can't buy stuff +that's not produced likewise we'll do + + align:start position:0% +that's not produced likewise we'll do + + + align:start position:0% +that's not produced likewise we'll do +examples later with a price floor where + + align:start position:0% +examples later with a price floor where + + + align:start position:0% +examples later with a price floor where +suppliers where could worship where + + align:start position:0% +suppliers where could worship where + + + align:start position:0% +suppliers where could worship where +consumers want less the suppliers want + + align:start position:0% +consumers want less the suppliers want + + + align:start position:0% +consumers want less the suppliers want +it but will provide then its consumers + + align:start position:0% +it but will provide then its consumers + + + align:start position:0% +it but will provide then its consumers +that decide what gets sold so mace + + align:start position:0% +that decide what gets sold so mace + + + align:start position:0% +that decide what gets sold so mace +whoever wants less gets to decide + + align:start position:0% +whoever wants less gets to decide + + + align:start position:0% +whoever wants less gets to decide +because you can't force the producers to + + align:start position:0% +because you can't force the producers to + + + align:start position:0% +because you can't force the producers to +produce more we don't know we have a + + align:start position:0% +produce more we don't know we have a + + + align:start position:0% +produce more we don't know we have a +private oil industry gas industry so you + + align:start position:0% +private oil industry gas industry so you + + + align:start position:0% +private oil industry gas industry so you +end up with qsr units of gas sold at a + + align:start position:0% +end up with qsr units of gas sold at a + + + align:start position:0% +end up with qsr units of gas sold at a +price p1 so what the price ceiling does + + align:start position:0% +price p1 so what the price ceiling does + + + align:start position:0% +price p1 so what the price ceiling does +is move you from e1 to e3 you would have + + align:start position:0% +is move you from e1 to e3 you would have + + + align:start position:0% +is move you from e1 to e3 you would have +moved to e2 without the government + + align:start position:0% +moved to e2 without the government + + + align:start position:0% +moved to e2 without the government +intervention instead it moves you to e3 + + align:start position:0% +intervention instead it moves you to e3 + + + align:start position:0% +intervention instead it moves you to e3 +ok and as a result you end up with + + align:start position:0% +ok and as a result you end up with + + + align:start position:0% +ok and as a result you end up with +consumers consumer surplus being a plus + + align:start position:0% +consumers consumer surplus being a plus + + + align:start position:0% +consumers consumer surplus being a plus +C producer surplus being e and relative + + align:start position:0% +C producer surplus being e and relative + + + align:start position:0% +C producer surplus being e and relative +to an unconstrained world I wrote over + + align:start position:0% +to an unconstrained world I wrote over + + + align:start position:0% +to an unconstrained world I wrote over +before but relative without government + + align:start position:0% +before but relative without government + + + align:start position:0% +before but relative without government +intervention you have a deadweight loss + + align:start position:0% +intervention you have a deadweight loss + + + align:start position:0% +intervention you have a deadweight loss +of B plus D yeah well that's a very deep + + align:start position:0% +of B plus D yeah well that's a very deep + + + align:start position:0% +of B plus D yeah well that's a very deep +question the guy says that we don't have + + align:start position:0% +question the guy says that we don't have + + + align:start position:0% +question the guy says that we don't have +a nationalized gas industry we just have + + align:start position:0% +a nationalized gas industry we just have + + + align:start position:0% +a nationalized gas industry we just have +private gas industries there's a + + align:start position:0% +private gas industries there's a + + + align:start position:0% +private gas industries there's a +separate issue you know a larger issue + + align:start position:0% +separate issue you know a larger issue + + + align:start position:0% +separate issue you know a larger issue +about whether private or public sector + + align:start position:0% +about whether private or public sector + + + align:start position:0% +about whether private or public sector +should be producing things and that's + + align:start position:0% +should be producing things and that's + + + align:start position:0% +should be producing things and that's +sort of beyond the scope of what we're + + align:start position:0% +sort of beyond the scope of what we're + + + align:start position:0% +sort of beyond the scope of what we're +discussing here but for now assume the + + align:start position:0% +discussing here but for now assume the + + + align:start position:0% +discussing here but for now assume the +government just has a regulatory role + + align:start position:0% +government just has a regulatory role + + + align:start position:0% +government just has a regulatory role +not a gas production role the government + + align:start position:0% +not a gas production role the government + + + align:start position:0% +not a gas production role the government +by the way does have a little gas + + align:start position:0% +by the way does have a little gas + + + align:start position:0% +by the way does have a little gas +production role because the government + + align:start position:0% +production role because the government + + + align:start position:0% +production role because the government +actually something called the strategic + + align:start position:0% +actually something called the strategic + + + align:start position:0% +actually something called the strategic +oil reserve where they have millions of + + align:start position:0% +oil reserve where they have millions of + + + align:start position:0% +oil reserve where they have millions of +barrels they can actually release and + + align:start position:0% +barrels they can actually release and + + + align:start position:0% +barrels they can actually release and +release out in the market at certain + + align:start position:0% +release out in the market at certain + + + align:start position:0% +release out in the market at certain +times the government does have a way try + + align:start position:0% +times the government does have a way try + + + align:start position:0% +times the government does have a way try +to deal with this but for now let's + + align:start position:0% +to deal with this but for now let's + + + align:start position:0% +to deal with this but for now let's +assume that I could use the strategic + + align:start position:0% +assume that I could use the strategic + + + align:start position:0% +assume that I could use the strategic +reserve just regulate price ok so they + + align:start position:0% +reserve just regulate price ok so they + + + align:start position:0% +reserve just regulate price ok so they +regulate price and what they've done is + + align:start position:0% +regulate price and what they've done is + + + align:start position:0% +regulate price and what they've done is +they've created a deadweight loss ok so + + align:start position:0% +they've created a deadweight loss ok so + + + align:start position:0% +they've created a deadweight loss ok so +basically if we think about it what are + + align:start position:0% +basically if we think about it what are + + + align:start position:0% +basically if we think about it what are +the costs and benefits of government + + align:start position:0% +the costs and benefits of government + + + align:start position:0% +the costs and benefits of government +intervention the costs of government + + align:start position:0% +intervention the costs of government + + + align:start position:0% +intervention the costs of government +intervention are twofold + + align:start position:0% +intervention are twofold + + + align:start position:0% +intervention are twofold +what are the costs of this price ceiling + + align:start position:0% +what are the costs of this price ceiling + + + align:start position:0% +what are the costs of this price ceiling +there's two costs cost one is you've + + align:start position:0% +there's two costs cost one is you've + + + align:start position:0% +there's two costs cost one is you've +created an inefficiency you've created + + align:start position:0% +created an inefficiency you've created + + + align:start position:0% +created an inefficiency you've created +you straighten this deadweight loss + + align:start position:0% +you straighten this deadweight loss + + + align:start position:0% +you straighten this deadweight loss +because basically if you didn't restrict + + align:start position:0% +because basically if you didn't restrict + + + align:start position:0% +because basically if you didn't restrict +things there are people who would have + + align:start position:0% +things there are people who would have + + + align:start position:0% +things there are people who would have +bought gas to the right of Q sub s and + + align:start position:0% +bought gas to the right of Q sub s and + + + align:start position:0% +bought gas to the right of Q sub s and +to the left of e to those units between + + align:start position:0% +to the left of e to those units between + + + align:start position:0% +to the left of e to those units between +Q sub s and E to worry to intersects the + + align:start position:0% +Q sub s and E to worry to intersects the + + + align:start position:0% +Q sub s and E to worry to intersects the +x axis those are units where the + + align:start position:0% +x axis those are units where the + + + align:start position:0% +x axis those are units where the +consumer surplus plus the Bruce surplus + + align:start position:0% +consumer surplus plus the Bruce surplus + + + align:start position:0% +consumer surplus plus the Bruce surplus +is positive right you look at the unit + + align:start position:0% +is positive right you look at the unit + + + align:start position:0% +is positive right you look at the unit +right to the right of Q sub s that's a + + align:start position:0% +right to the right of Q sub s that's a + + + align:start position:0% +right to the right of Q sub s that's a +unit that would have that consumers + + align:start position:0% +unit that would have that consumers + + + align:start position:0% +unit that would have that consumers +would have happily bought at the new + + align:start position:0% +would have happily bought at the new + + + align:start position:0% +would have happily bought at the new +higher price and producer would have + + align:start position:0% +higher price and producer would have + + + align:start position:0% +higher price and producer would have +happily sold the new higher price but + + align:start position:0% +happily sold the new higher price but + + + align:start position:0% +happily sold the new higher price but +the government isn't letting it happen + + align:start position:0% +the government isn't letting it happen + + + align:start position:0% +the government isn't letting it happen +so that's a deadweight loss so that's an + + align:start position:0% +so that's a deadweight loss so that's an + + + align:start position:0% +so that's a deadweight loss so that's an +inefficiency okay so that's the first + + align:start position:0% +inefficiency okay so that's the first + + + align:start position:0% +inefficiency okay so that's the first +cost the cost of society of trades that + + align:start position:0% +cost the cost of society of trades that + + + align:start position:0% +cost the cost of society of trades that +don't get made and we call this an + + align:start position:0% +don't get made and we call this an + + + align:start position:0% +don't get made and we call this an +efficiency loss because there are + + align:start position:0% +efficiency loss because there are + + + align:start position:0% +efficiency loss because there are +efficient trays trake things are + + align:start position:0% +efficient trays trake things are + + + align:start position:0% +efficient trays trake things are +efficient if they make the whole the + + align:start position:0% +efficient if they make the whole the + + + align:start position:0% +efficient if they make the whole the +joint surplus is positive if I net + + align:start position:0% +joint surplus is positive if I net + + + align:start position:0% +joint surplus is positive if I net +people are better off there are fishing + + align:start position:0% +people are better off there are fishing + + + align:start position:0% +people are better off there are fishing +trades + + align:start position:0% +trades + + + align:start position:0% +trades +which both sides were happy to make and + + align:start position:0% +which both sides were happy to make and + + + align:start position:0% +which both sides were happy to make and +they can't mate and they can't make so + + align:start position:0% +they can't mate and they can't make so + + + align:start position:0% +they can't mate and they can't make so +we call us an efficiency loss okay but + + align:start position:0% +we call us an efficiency loss okay but + + + align:start position:0% +we call us an efficiency loss okay but +that's not the only cost to this policy + + align:start position:0% +that's not the only cost to this policy + + + align:start position:0% +that's not the only cost to this policy +what's the other cost it's a hard + + align:start position:0% +what's the other cost it's a hard + + + align:start position:0% +what's the other cost it's a hard +question yeah so this enforcement you + + align:start position:0% +question yeah so this enforcement you + + + align:start position:0% +question yeah so this enforcement you +have to like go around send regulars + + align:start position:0% +have to like go around send regulars + + + align:start position:0% +have to like go around send regulars +around the gas stations make sure + + align:start position:0% +around the gas stations make sure + + + align:start position:0% +around the gas stations make sure +they're not charging the wrong price + + align:start position:0% +they're not charging the wrong price + + + align:start position:0% +they're not charging the wrong price +that's true I sort of make that small + + align:start position:0% +that's true I sort of make that small + + + align:start position:0% +that's true I sort of make that small +let's take more sort of a theoretical + + align:start position:0% +let's take more sort of a theoretical + + + align:start position:0% +let's take more sort of a theoretical +not theoretical but what's the other big + + align:start position:0% +not theoretical but what's the other big + + + align:start position:0% +not theoretical but what's the other big +source of what yeah + + align:start position:0% + + + + align:start position:0% + +there's sort of a dynamic but once again + + align:start position:0% +there's sort of a dynamic but once again + + + align:start position:0% +there's sort of a dynamic but once again +the producers think this may be a + + align:start position:0% +the producers think this may be a + + + align:start position:0% +the producers think this may be a +short-run thing and what's the pro you + + align:start position:0% +short-run thing and what's the pro you + + + align:start position:0% +short-run thing and what's the pro you +know once the deepwater horizon gets + + align:start position:0% +know once the deepwater horizon gets + + + align:start position:0% +know once the deepwater horizon gets +fixed they'll prices will be back down + + align:start position:0% +fixed they'll prices will be back down + + + align:start position:0% +fixed they'll prices will be back down +or whatever but what's the other miracle + + align:start position:0% +or whatever but what's the other miracle + + + align:start position:0% +or whatever but what's the other miracle +of the market that we lose here what + + align:start position:0% +of the market that we lose here what + + + align:start position:0% +of the market that we lose here what +time is the very first lecture yeah but + + align:start position:0% +time is the very first lecture yeah but + + + align:start position:0% +time is the very first lecture yeah but +that's one lets rule out of choice + + align:start position:0% +that's one lets rule out of choice + + + align:start position:0% +that's one lets rule out of choice +because just a short-run deal yeah yes + + align:start position:0% +because just a short-run deal yeah yes + + + align:start position:0% +because just a short-run deal yeah yes +there's allocated inefficiency remember + + align:start position:0% +there's allocated inefficiency remember + + + align:start position:0% +there's allocated inefficiency remember +one of the things we talked about in the + + align:start position:0% +one of the things we talked about in the + + + align:start position:0% +one of the things we talked about in the +very first lecture I think we did maybe + + align:start position:0% +very first lecture I think we did maybe + + + align:start position:0% +very first lecture I think we did maybe +not + + align:start position:0% +not + + + align:start position:0% +not +anyway one of the most important + + align:start position:0% +anyway one of the most important + + + align:start position:0% +anyway one of the most important +benefits of the competitive equilibrium + + align:start position:0% +benefits of the competitive equilibrium + + + align:start position:0% +benefits of the competitive equilibrium +it doesn't just deliver the right + + align:start position:0% +it doesn't just deliver the right + + + align:start position:0% +it doesn't just deliver the right +quantity it delivers it to the people + + align:start position:0% +quantity it delivers it to the people + + + align:start position:0% +quantity it delivers it to the people +who want it the most so if you think + + align:start position:0% +who want it the most so if you think + + + align:start position:0% +who want it the most so if you think +about let's go back to figure 10 - it's + + align:start position:0% +about let's go back to figure 10 - it's + + + align:start position:0% +about let's go back to figure 10 - it's +easy to see there if you think about who + + align:start position:0% +easy to see there if you think about who + + + align:start position:0% +easy to see there if you think about who +gets gas at the initial equity one and + + align:start position:0% +gets gas at the initial equity one and + + + align:start position:0% +gets gas at the initial equity one and +actually no but let's go ten three + + align:start position:0% +actually no but let's go ten three + + + align:start position:0% +actually no but let's go ten three +that's fine so let's say we hadn't + + align:start position:0% +that's fine so let's say we hadn't + + + align:start position:0% +that's fine so let's say we hadn't +interfered and we'd allowed the price to + + align:start position:0% +interfered and we'd allowed the price to + + + align:start position:0% +interfered and we'd allowed the price to +go to e - well fewer people would've + + align:start position:0% +go to e - well fewer people would've + + + align:start position:0% +go to e - well fewer people would've +bought gas right supply the quantity + + align:start position:0% +bought gas right supply the quantity + + + align:start position:0% +bought gas right supply the quantity +would have fallen from QD would have + + align:start position:0% +would have fallen from QD would have + + + align:start position:0% +would have fallen from QD would have +fallen all the way from e1 to e2 but the + + align:start position:0% +fallen all the way from e1 to e2 but the + + + align:start position:0% +fallen all the way from e1 to e2 but the +people who dropped out would have been + + align:start position:0% +people who dropped out would have been + + + align:start position:0% +people who dropped out would have been +who the people who value gas - the least + + align:start position:0% +who the people who value gas - the least + + + align:start position:0% +who the people who value gas - the least +the people who got the lowest surplus + + align:start position:0% +the people who got the lowest surplus + + + align:start position:0% +the people who got the lowest surplus +from it okay however now suddenly you + + align:start position:0% +from it okay however now suddenly you + + + align:start position:0% +from it okay however now suddenly you +only have qsr units of gas and you have + + align:start position:0% +only have qsr units of gas and you have + + + align:start position:0% +only have qsr units of gas and you have +QD people who want them well now who + + align:start position:0% +QD people who want them well now who + + + align:start position:0% +QD people who want them well now who +decides who gets them before the market + + align:start position:0% +decides who gets them before the market + + + align:start position:0% +decides who gets them before the market +did the magic the market made sure the + + align:start position:0% +did the magic the market made sure the + + + align:start position:0% +did the magic the market made sure the +people who wanted the unit's got them + + align:start position:0% +people who wanted the unit's got them + + + align:start position:0% +people who wanted the unit's got them +now of a sudden something else has to + + align:start position:0% +now of a sudden something else has to + + + align:start position:0% +now of a sudden something else has to +decide so how do you resolve this well + + align:start position:0% +decide so how do you resolve this well + + + align:start position:0% +decide so how do you resolve this well +we actually had an answer to this we had + + align:start position:0% +we actually had an answer to this we had + + + align:start position:0% +we actually had an answer to this we had +a gas crisis in the 1970s and the + + align:start position:0% +a gas crisis in the 1970s and the + + + align:start position:0% +a gas crisis in the 1970s and the +government imposed the price ceiling and + + align:start position:0% +government imposed the price ceiling and + + + align:start position:0% +government imposed the price ceiling and +have it get resolved how do we decide + + align:start position:0% +have it get resolved how do we decide + + + align:start position:0% +have it get resolved how do we decide +then who got the gas does anyone know + + align:start position:0% +then who got the gas does anyone know + + + align:start position:0% +then who got the gas does anyone know +raise your hand tell me if you know yeah + + align:start position:0% + + + + align:start position:0% + +people wait in line people basically sat + + align:start position:0% +people wait in line people basically sat + + + align:start position:0% +people wait in line people basically sat +in their cars and waited in line okay + + align:start position:0% +in their cars and waited in line okay + + + align:start position:0% +in their cars and waited in line okay +now so essentially if you think about it + + align:start position:0% +now so essentially if you think about it + + + align:start position:0% +now so essentially if you think about it +we goods are going to get allocated + + align:start position:0% +we goods are going to get allocated + + + align:start position:0% +we goods are going to get allocated +somehow if the market isn't allocate + + align:start position:0% +somehow if the market isn't allocate + + + align:start position:0% +somehow if the market isn't allocate +them there'll be another less efficient + + align:start position:0% +them there'll be another less efficient + + + align:start position:0% +them there'll be another less efficient +allocation mechanism okay and basically + + align:start position:0% +allocation mechanism okay and basically + + + align:start position:0% +allocation mechanism okay and basically +why is it inefficient that people waited + + align:start position:0% +why is it inefficient that people waited + + + align:start position:0% +why is it inefficient that people waited +in line for gas there's actually two + + align:start position:0% +in line for gas there's actually two + + + align:start position:0% +in line for gas there's actually two +reasons one sort of cute but what's the + + align:start position:0% +reasons one sort of cute but what's the + + + align:start position:0% +reasons one sort of cute but what's the +main reason officially waiting in line + + align:start position:0% +main reason officially waiting in line + + + align:start position:0% +main reason officially waiting in line +for gas yeah yes the opportunity cost + + align:start position:0% +for gas yeah yes the opportunity cost + + + align:start position:0% +for gas yeah yes the opportunity cost +little point little one you have the + + align:start position:0% +little point little one you have the + + + align:start position:0% +little point little one you have the +opportunity cost okay you have the fact + + align:start position:0% +opportunity cost okay you have the fact + + + align:start position:0% +opportunity cost okay you have the fact +that that time I spent waiting in line I + + align:start position:0% +that that time I spent waiting in line I + + + align:start position:0% +that that time I spent waiting in line I +could have been working or having fun + + align:start position:0% +could have been working or having fun + + + align:start position:0% +could have been working or having fun +but certainly something I would've + + align:start position:0% +but certainly something I would've + + + align:start position:0% +but certainly something I would've +enjoyed more than waiting line for gas I + + align:start position:0% +enjoyed more than waiting line for gas I + + + align:start position:0% +enjoyed more than waiting line for gas I +think we'd all agree that there's + + align:start position:0% +think we'd all agree that there's + + + align:start position:0% +think we'd all agree that there's +something we'd rather be doing with our + + align:start position:0% +something we'd rather be doing with our + + + align:start position:0% +something we'd rather be doing with our +time than waiting in line for gas okay + + align:start position:0% +time than waiting in line for gas okay + + + align:start position:0% +time than waiting in line for gas okay +unless you really like the music getting + + align:start position:0% +unless you really like the music getting + + + align:start position:0% +unless you really like the music getting +your car stereo you can't listen + + align:start position:0% +your car stereo you can't listen + + + align:start position:0% +your car stereo you can't listen +anywhere else I don't know what the + + align:start position:0% +anywhere else I don't know what the + + + align:start position:0% +anywhere else I don't know what the +story would be but I can't imagine that + + align:start position:0% +story would be but I can't imagine that + + + align:start position:0% +story would be but I can't imagine that +many of us would prefer to wait in line + + align:start position:0% +many of us would prefer to wait in line + + + align:start position:0% +many of us would prefer to wait in line +for gas do something else does the + + align:start position:0% +for gas do something else does the + + + align:start position:0% +for gas do something else does the +opportunity cost that's it inefficiency + + align:start position:0% +opportunity cost that's it inefficiency + + + align:start position:0% +opportunity cost that's it inefficiency +society is losing out because you are + + align:start position:0% +society is losing out because you are + + + align:start position:0% +society is losing out because you are +not using your time in the most + + align:start position:0% +not using your time in the most + + + align:start position:0% +not using your time in the most +productive way and the way that maximize + + align:start position:0% +productive way and the way that maximize + + + align:start position:0% +productive way and the way that maximize +your welfare okay so there's that what + + align:start position:0% +your welfare okay so there's that what + + + align:start position:0% +your welfare okay so there's that what +else what's the other small other cost + + align:start position:0% +else what's the other small other cost + + + align:start position:0% +else what's the other small other cost +yeah yeah people use gas waiting in line + + align:start position:0% +yeah yeah people use gas waiting in line + + + align:start position:0% +yeah yeah people use gas waiting in line +so there's literally the technical and + + align:start position:0% +so there's literally the technical and + + + align:start position:0% +so there's literally the technical and +efficiency and remember this is like + + align:start position:0% +efficiency and remember this is like + + + align:start position:0% +efficiency and remember this is like +back when cars got like eight miles to + + align:start position:0% +back when cars got like eight miles to + + + align:start position:0% +back when cars got like eight miles to +the gallon so you'd like get to the + + align:start position:0% +the gallon so you'd like get to the + + + align:start position:0% +the gallon so you'd like get to the +front line get gas let's go back to the + + align:start position:0% +front line get gas let's go back to the + + + align:start position:0% +front line get gas let's go back to the +back of the line again because use so + + align:start position:0% +back of the line again because use so + + + align:start position:0% +back of the line again because use so +much gas plus not to mention the + + align:start position:0% +much gas plus not to mention the + + + align:start position:0% +much gas plus not to mention the +pollution all that other stuff so + + align:start position:0% +pollution all that other stuff so + + + align:start position:0% +pollution all that other stuff so +basically this is the inefficiency from + + align:start position:0% +basically this is the inefficiency from + + + align:start position:0% +basically this is the inefficiency from +an on market allocation mechanism okay + + align:start position:0% +an on market allocation mechanism okay + + + align:start position:0% +an on market allocation mechanism okay +which is that people could be doing more + + align:start position:0% +which is that people could be doing more + + + align:start position:0% +which is that people could be doing more +productive things and not wasting gas + + align:start position:0% +productive things and not wasting gas + + + align:start position:0% +productive things and not wasting gas +waiting in line yeah + + align:start position:0% + + + + align:start position:0% + +ya know QD month because we fixed the + + align:start position:0% +ya know QD month because we fixed the + + + align:start position:0% +ya know QD month because we fixed the +price of p1 so it's QD months cute since + + align:start position:0% +price of p1 so it's QD months cute since + + + align:start position:0% +price of p1 so it's QD months cute since +we Prix the fysop re1 people want what's + + align:start position:0% +we Prix the fysop re1 people want what's + + + align:start position:0% +we Prix the fysop re1 people want what's +the demand at that price QD let's apply + + align:start position:0% +the demand at that price QD let's apply + + + align:start position:0% +the demand at that price QD let's apply +the price Q s so that's the excess + + align:start position:0% +the price Q s so that's the excess + + + align:start position:0% +the price Q s so that's the excess +demand okay so now no it doesn't but it + + align:start position:0% +demand okay so now no it doesn't but it + + + align:start position:0% +demand okay so now no it doesn't but it +does assume that B basically the market + + align:start position:0% +does assume that B basically the market + + + align:start position:0% +does assume that B basically the market +and this comes to the trade off what's + + align:start position:0% +and this comes to the trade off what's + + + align:start position:0% +and this comes to the trade off what's +the benefit of this policy which you've + + align:start position:0% +the benefit of this policy which you've + + + align:start position:0% +the benefit of this policy which you've +raised with your question which is + + align:start position:0% +raised with your question which is + + + align:start position:0% +raised with your question which is +equity which is I've defined consumer + + align:start position:0% +equity which is I've defined consumer + + + align:start position:0% +equity which is I've defined consumer +surplus as simply being with the market + + align:start position:0% +surplus as simply being with the market + + + align:start position:0% +surplus as simply being with the market +delivers so basically rich guys have + + align:start position:0% +delivers so basically rich guys have + + + align:start position:0% +delivers so basically rich guys have +more consumer surplus than poor guys + + align:start position:0% +more consumer surplus than poor guys + + + align:start position:0% +more consumer surplus than poor guys +okay that might not seem fair to people + + align:start position:0% +okay that might not seem fair to people + + + align:start position:0% +okay that might not seem fair to people +okay as a result the benefit is equity + + align:start position:0% +okay as a result the benefit is equity + + + align:start position:0% +okay as a result the benefit is equity +which is that if you that everyone gets + + align:start position:0% +which is that if you that everyone gets + + + align:start position:0% +which is that if you that everyone gets +gas at a lower price rather the price + + align:start position:0% +gas at a lower price rather the price + + + align:start position:0% +gas at a lower price rather the price +rise and the people who drop out may + + align:start position:0% +rise and the people who drop out may + + + align:start position:0% +rise and the people who drop out may +actually not be the people who don't + + align:start position:0% +actually not be the people who don't + + + align:start position:0% +actually not be the people who don't +need to drive the people can't afford to + + align:start position:0% +need to drive the people can't afford to + + + align:start position:0% +need to drive the people can't afford to +drive so they drop out remember where + + align:start position:0% +drive so they drop out remember where + + + align:start position:0% +drive so they drop out remember where +does the demand curve come from scums + + align:start position:0% +does the demand curve come from scums + + + align:start position:0% +does the demand curve come from scums +utility maximization that's a + + align:start position:0% +utility maximization that's a + + + align:start position:0% +utility maximization that's a +constrained maximization so the people + + align:start position:0% +constrained maximization so the people + + + align:start position:0% +constrained maximization so the people +who drop out mate maybe people we want + + align:start position:0% +who drop out mate maybe people we want + + + align:start position:0% +who drop out mate maybe people we want +maybe their people have to lose their + + align:start position:0% +maybe their people have to lose their + + + align:start position:0% +maybe their people have to lose their +jobs as they can't drive to their jobs + + align:start position:0% +jobs as they can't drive to their jobs + + + align:start position:0% +jobs as they can't drive to their jobs +anymore + + align:start position:0% +anymore + + + align:start position:0% +anymore +that's unfortunate so basically the the + + align:start position:0% +that's unfortunate so basically the the + + + align:start position:0% +that's unfortunate so basically the the +benefit of this is equity and that + + align:start position:0% +benefit of this is equity and that + + + align:start position:0% +benefit of this is equity and that +raises something were to come back to + + align:start position:0% +raises something were to come back to + + + align:start position:0% +raises something were to come back to +over and over again in this class which + + align:start position:0% +over and over again in this class which + + + align:start position:0% +over and over again in this class which +is what we call the equity efficiency + + align:start position:0% +is what we call the equity efficiency + + + align:start position:0% +is what we call the equity efficiency +trade-off okay the equity efficiency + + align:start position:0% +trade-off okay the equity efficiency + + + align:start position:0% +trade-off okay the equity efficiency +trade-off which is there are many + + align:start position:0% +trade-off which is there are many + + + align:start position:0% +trade-off which is there are many +government policies which make society + + align:start position:0% +government policies which make society + + + align:start position:0% +government policies which make society +more equal but along the way deliver + + align:start position:0% +more equal but along the way deliver + + + align:start position:0% +more equal but along the way deliver +deadweight loss and I'll actually tell + + align:start position:0% +deadweight loss and I'll actually tell + + + align:start position:0% +deadweight loss and I'll actually tell +you later in the class how to optimize + + align:start position:0% +you later in the class how to optimize + + + align:start position:0% +you later in the class how to optimize +across that problem how to optimize + + align:start position:0% +across that problem how to optimize + + + align:start position:0% +across that problem how to optimize +across - trade-off between equity and + + align:start position:0% +across - trade-off between equity and + + + align:start position:0% +across - trade-off between equity and +efficiency but for right now I just need + + align:start position:0% +efficiency but for right now I just need + + + align:start position:0% +efficiency but for right now I just need +to understand that there's that there's + + align:start position:0% +to understand that there's that there's + + + align:start position:0% +to understand that there's that there's +a trade-off okay yeah + + align:start position:0% + + + + align:start position:0% + +in this milk ice feeling that the people + + align:start position:0% +in this milk ice feeling that the people + + + align:start position:0% +in this milk ice feeling that the people +who are able to pay the most money will + + align:start position:0% +who are able to pay the most money will + + + align:start position:0% +who are able to pay the most money will +yeah exactly so the point is right the + + align:start position:0% +yeah exactly so the point is right the + + + align:start position:0% +yeah exactly so the point is right the +people who would do more dear it's a + + align:start position:0% +people who would do more dear it's a + + + align:start position:0% +people who would do more dear it's a +different kind of inequity so if you're + + align:start position:0% +different kind of inequity so if you're + + + align:start position:0% +different kind of inequity so if you're +worried about so in some sense the rich + + align:start position:0% +worried about so in some sense the rich + + + align:start position:0% +worried about so in some sense the rich +guy would say well that's not fair to me + + align:start position:0% +guy would say well that's not fair to me + + + align:start position:0% +guy would say well that's not fair to me +just because I've got a productive job I + + align:start position:0% +just because I've got a productive job I + + + align:start position:0% +just because I've got a productive job I +could be doing and someone else has + + align:start position:0% +could be doing and someone else has + + + align:start position:0% +could be doing and someone else has +extra time why should they get the gas + + align:start position:0% +extra time why should they get the gas + + + align:start position:0% +extra time why should they get the gas +instead of me so you're right there's + + align:start position:0% +instead of me so you're right there's + + + align:start position:0% +instead of me so you're right there's +always sort of an inequity I guess when + + align:start position:0% +always sort of an inequity I guess when + + + align:start position:0% +always sort of an inequity I guess when +I say equity that's a great point when I + + align:start position:0% +I say equity that's a great point when I + + + align:start position:0% +I say equity that's a great point when I +say could I implicitly mean what we call + + align:start position:0% +say could I implicitly mean what we call + + + align:start position:0% +say could I implicitly mean what we call +that's actually a very important point + + align:start position:0% +that's actually a very important point + + + align:start position:0% +that's actually a very important point +whatever say equity in this course I + + align:start position:0% +whatever say equity in this course I + + + align:start position:0% +whatever say equity in this course I +implicitly mean what we call vertical + + align:start position:0% +implicitly mean what we call vertical + + + align:start position:0% +implicitly mean what we call vertical +equity vertical equity is rich versus + + align:start position:0% +equity vertical equity is rich versus + + + align:start position:0% +equity vertical equity is rich versus +poor okay there are other kinds of + + align:start position:0% +poor okay there are other kinds of + + + align:start position:0% +poor okay there are other kinds of +equity you might care about like who has + + align:start position:0% +equity you might care about like who has + + + align:start position:0% +equity you might care about like who has +extra time versus who doesn't have extra + + align:start position:0% +extra time versus who doesn't have extra + + + align:start position:0% +extra time versus who doesn't have extra +time okay but and and that's a good + + align:start position:0% +time okay but and and that's a good + + + align:start position:0% +time okay but and and that's a good +point but for now and I think I could + + align:start position:0% +point but for now and I think I could + + + align:start position:0% +point but for now and I think I could +ever think about rich versus poor we + + align:start position:0% +ever think about rich versus poor we + + + align:start position:0% +ever think about rich versus poor we +think about government policy equity + + align:start position:0% +think about government policy equity + + + align:start position:0% +think about government policy equity +efficiency trade-off we really think + + align:start position:0% +efficiency trade-off we really think + + + align:start position:0% +efficiency trade-off we really think +about vertical equity okay other + + align:start position:0% +about vertical equity okay other + + + align:start position:0% +about vertical equity okay other +questions about that okay + + align:start position:0% +questions about that okay + + + align:start position:0% +questions about that okay +so let's do a couple more examples to + + align:start position:0% +so let's do a couple more examples to + + + align:start position:0% +so let's do a couple more examples to +drill this intuition home okay let's do + + align:start position:0% +drill this intuition home okay let's do + + + align:start position:0% +drill this intuition home okay let's do +a couple more examples because this is a + + align:start position:0% +a couple more examples because this is a + + + align:start position:0% +a couple more examples because this is a +very important point okay example a + + align:start position:0% +very important point okay example a + + + align:start position:0% +very important point okay example a +let's talk about ticket scalping okay I + + align:start position:0% +let's talk about ticket scalping okay I + + + align:start position:0% +let's talk about ticket scalping okay I +love going to I go I love going to music + + align:start position:0% +love going to I go I love going to music + + + align:start position:0% +love going to I go I love going to music +concerts one of my 51st concert of the + + align:start position:0% +concerts one of my 51st concert of the + + + align:start position:0% +concerts one of my 51st concert of the +year last year last night sorry went to + + align:start position:0% +year last year last night sorry went to + + + align:start position:0% +year last year last night sorry went to +my 51st cars to here I love going a + + align:start position:0% +my 51st cars to here I love going a + + + align:start position:0% +my 51st cars to here I love going a +music concert so I know a lot about the + + align:start position:0% +music concert so I know a lot about the + + + align:start position:0% +music concert so I know a lot about the +music business and ticket scalping at + + align:start position:0% +music business and ticket scalping at + + + align:start position:0% +music business and ticket scalping at +concerts a big deal for those who know + + align:start position:0% +concerts a big deal for those who know + + + align:start position:0% +concerts a big deal for those who know +the term this is the idea of buying + + align:start position:0% +the term this is the idea of buying + + + align:start position:0% +the term this is the idea of buying +tickets essentially on a secondary + + align:start position:0% +tickets essentially on a secondary + + + align:start position:0% +tickets essentially on a secondary +market so let's use the example of Adele + + align:start position:0% +market so let's use the example of Adele + + + align:start position:0% +market so let's use the example of Adele +so Adele about two years ago went on + + align:start position:0% +so Adele about two years ago went on + + + align:start position:0% +so Adele about two years ago went on +tour for the first time in four years to + + align:start position:0% +tour for the first time in four years to + + + align:start position:0% +tour for the first time in four years to +back up an incredibly successful album + + align:start position:0% +back up an incredibly successful album + + + align:start position:0% +back up an incredibly successful album +and folks really want to see your life + + align:start position:0% +and folks really want to see your life + + + align:start position:0% +and folks really want to see your life +because she had a big fan base she was + + align:start position:0% +because she had a big fan base she was + + + align:start position:0% +because she had a big fan base she was +quiet for a while she made now whom + + align:start position:0% +quiet for a while she made now whom + + + align:start position:0% +quiet for a while she made now whom +people really want to see her life she + + align:start position:0% +people really want to see her life she + + + align:start position:0% +people really want to see her life she +wanted to make sure her fans could + + align:start position:0% +wanted to make sure her fans could + + + align:start position:0% +wanted to make sure her fans could +afford to see her so what she did is she + + align:start position:0% +afford to see her so what she did is she + + + align:start position:0% +afford to see her so what she did is she +said I'm gonna price tickets that many + + align:start position:0% +said I'm gonna price tickets that many + + + align:start position:0% +said I'm gonna price tickets that many +tickets for $40 and the highest tickets + + align:start position:0% +tickets for $40 and the highest tickets + + + align:start position:0% +tickets for $40 and the highest tickets +at 150 which is really really cheap so + + align:start position:0% +at 150 which is really really cheap so + + + align:start position:0% +at 150 which is really really cheap so +my daughter's going to see Jay Cole + + align:start position:0% +my daughter's going to see Jay Cole + + + align:start position:0% +my daughter's going to see Jay Cole +tonight and she's paying + + align:start position:0% +tonight and she's paying + + + align:start position:0% +tonight and she's paying +like 150 for a mediocre ticket okay so + + align:start position:0% +like 150 for a mediocre ticket okay so + + + align:start position:0% +like 150 for a mediocre ticket okay so +40 to 150 s really cheap okay + + align:start position:0% +40 to 150 s really cheap okay + + + align:start position:0% +40 to 150 s really cheap okay +but she's saying I want to live our + + align:start position:0% +but she's saying I want to live our + + + align:start position:0% +but she's saying I want to live our +consumer surplus to my fans I wanna make + + align:start position:0% +consumer surplus to my fans I wanna make + + + align:start position:0% +consumer surplus to my fans I wanna make +sure my fans can really enjoy this enjoy + + align:start position:0% +sure my fans can really enjoy this enjoy + + + align:start position:0% +sure my fans can really enjoy this enjoy +this I get surplus but what happened + + align:start position:0% +this I get surplus but what happened + + + align:start position:0% +this I get surplus but what happened +well what happened is that the tickets + + align:start position:0% +well what happened is that the tickets + + + align:start position:0% +well what happened is that the tickets +sold out instantly + + align:start position:0% +sold out instantly + + + align:start position:0% +sold out instantly +like literally instantaneously and the + + align:start position:0% +like literally instantaneously and the + + + align:start position:0% +like literally instantaneously and the +major purchasers were what we call + + align:start position:0% +major purchasers were what we call + + + align:start position:0% +major purchasers were what we call +scalpers who are essentially + + align:start position:0% +scalpers who are essentially + + + align:start position:0% +scalpers who are essentially +professionals who buy tickets and then + + align:start position:0% +professionals who buy tickets and then + + + align:start position:0% +professionals who buy tickets and then +resell them on what we call the + + align:start position:0% +resell them on what we call the + + + align:start position:0% +resell them on what we call the +secondary market you might have heard of + + align:start position:0% +secondary market you might have heard of + + + align:start position:0% +secondary market you might have heard of +StubHub or other sites like that we're + + align:start position:0% +StubHub or other sites like that we're + + + align:start position:0% +StubHub or other sites like that we're +essentially go on and buy tickets to + + align:start position:0% +essentially go on and buy tickets to + + + align:start position:0% +essentially go on and buy tickets to +sold-out events and the prices on + + align:start position:0% +sold-out events and the prices on + + + align:start position:0% +sold-out events and the prices on +StubHub were much higher there's about + + align:start position:0% +StubHub were much higher there's about + + + align:start position:0% +StubHub were much higher there's about +$1,500 for a good ticket about ten times + + align:start position:0% +$1,500 for a good ticket about ten times + + + align:start position:0% +$1,500 for a good ticket about ten times +what she'd set the price at so basically + + align:start position:0% +what she'd set the price at so basically + + + align:start position:0% +what she'd set the price at so basically +who's getting a surplus not the fans the + + align:start position:0% +who's getting a surplus not the fans the + + + align:start position:0% +who's getting a surplus not the fans the +scalpers the people who are quick enough + + align:start position:0% +scalpers the people who are quick enough + + + align:start position:0% +scalpers the people who are quick enough +to get online who said box set up so the + + align:start position:0% +to get online who said box set up so the + + + align:start position:0% +to get online who said box set up so the +second it went online they went online + + align:start position:0% +second it went online they went online + + + align:start position:0% +second it went online they went online +and got the tickets they have thousands + + align:start position:0% +and got the tickets they have thousands + + + align:start position:0% +and got the tickets they have thousands +of BOTS set up essentially somehow they + + align:start position:0% +of BOTS set up essentially somehow they + + + align:start position:0% +of BOTS set up essentially somehow they +got around the click this if you're + + align:start position:0% +got around the click this if you're + + + align:start position:0% +got around the click this if you're +human box I don't how they do that + + align:start position:0% +human box I don't how they do that + + + align:start position:0% +human box I don't how they do that +but essentially I'm sure it's smart + + align:start position:0% +but essentially I'm sure it's smart + + + align:start position:0% +but essentially I'm sure it's smart +programmers you guys can probably do + + align:start position:0% +programmers you guys can probably do + + + align:start position:0% +programmers you guys can probably do +that in an hour as an extra credit + + align:start position:0% +that in an hour as an extra credit + + + align:start position:0% +that in an hour as an extra credit +project okay they got around it and they + + align:start position:0% +project okay they got around it and they + + + align:start position:0% +project okay they got around it and they +bought and so essentially Adele actually + + align:start position:0% +bought and so essentially Adele actually + + + align:start position:0% +bought and so essentially Adele actually +didn't create surplus for her fans she + + align:start position:0% +didn't create surplus for her fans she + + + align:start position:0% +didn't create surplus for her fans she +created surplus for scalpers okay now it + + align:start position:0% +created surplus for scalpers okay now it + + + align:start position:0% +created surplus for scalpers okay now it +didn't used to be this way when I was a + + align:start position:0% +didn't used to be this way when I was a + + + align:start position:0% +didn't used to be this way when I was a +kid we didn't have a secondary market + + align:start position:0% +kid we didn't have a secondary market + + + align:start position:0% +kid we didn't have a secondary market +we waited online so when I saw my first + + align:start position:0% +we waited online so when I saw my first + + + align:start position:0% +we waited online so when I saw my first +concert in 1981 you guys believe that + + align:start position:0% +concert in 1981 you guys believe that + + + align:start position:0% +concert in 1981 you guys believe that +1981 I saw the cars + + align:start position:0% +1981 I saw the cars + + + align:start position:0% +1981 I saw the cars +how many guys heard of the cars Oh God + + align:start position:0% +how many guys heard of the cars Oh God + + + align:start position:0% +how many guys heard of the cars Oh God +anyway so the cars I had to wait on line + + align:start position:0% +anyway so the cars I had to wait on line + + + align:start position:0% +anyway so the cars I had to wait on line +for hours to get tickets because that + + align:start position:0% +for hours to get tickets because that + + + align:start position:0% +for hours to get tickets because that +was that was the allocation mechanism so + + align:start position:0% +was that was the allocation mechanism so + + + align:start position:0% +was that was the allocation mechanism so +let's think about whether life is better + + align:start position:0% +let's think about whether life is better + + + align:start position:0% +let's think about whether life is better +or worse because on the one hand + + align:start position:0% +or worse because on the one hand + + + align:start position:0% +or worse because on the one hand +scalpers get money on the other hand + + align:start position:0% +scalpers get money on the other hand + + + align:start position:0% +scalpers get money on the other hand +people don't waste time waiting online + + align:start position:0% +people don't waste time waiting online + + + align:start position:0% +people don't waste time waiting online +so it really comes down to the same + + align:start position:0% +so it really comes down to the same + + + align:start position:0% +so it really comes down to the same +equity trade-off we talked about before + + align:start position:0% +equity trade-off we talked about before + + + align:start position:0% +equity trade-off we talked about before +now as a as a 16 year old 1981 I cannot + + align:start position:0% +now as a as a 16 year old 1981 I cannot + + + align:start position:0% +now as a as a 16 year old 1981 I cannot +have afforded to pay probably the + + align:start position:0% +have afforded to pay probably the + + + align:start position:0% +have afforded to pay probably the +secondary market price so I love but I + + align:start position:0% +secondary market price so I love but I + + + align:start position:0% +secondary market price so I love but I +was just 16 I'd nothing do with my time + + align:start position:0% +was just 16 I'd nothing do with my time + + + align:start position:0% +was just 16 I'd nothing do with my time +so I was happy to spend + + align:start position:0% +so I was happy to spend + + + align:start position:0% +so I was happy to spend +I was waiting online okay but on the + + align:start position:0% +I was waiting online okay but on the + + + align:start position:0% +I was waiting online okay but on the +other hand you could say someone is very + + align:start position:0% +other hand you could say someone is very + + + align:start position:0% +other hand you could say someone is very +productive who was a big fan who was + + align:start position:0% +productive who was a big fan who was + + + align:start position:0% +productive who was a big fan who was +very productive and could be out + + align:start position:0% +very productive and could be out + + + align:start position:0% +very productive and could be out +inventing new products if they weren't + + align:start position:0% +inventing new products if they weren't + + + align:start position:0% +inventing new products if they weren't +standing on line they might say that's + + align:start position:0% +standing on line they might say that's + + + align:start position:0% +standing on line they might say that's +really inefficient I'm happy to pay + + align:start position:0% +really inefficient I'm happy to pay + + + align:start position:0% +really inefficient I'm happy to pay +1,500 bucks to spend my time inventing + + align:start position:0% +1,500 bucks to spend my time inventing + + + align:start position:0% +1,500 bucks to spend my time inventing +new things rather than have to sit + + align:start position:0% +new things rather than have to sit + + + align:start position:0% +new things rather than have to sit +around waiting online so it's not clear + + align:start position:0% +around waiting online so it's not clear + + + align:start position:0% +around waiting online so it's not clear +which is the better or the worse system + + align:start position:0% +which is the better or the worse system + + + align:start position:0% +which is the better or the worse system +it's hard to say yeah well no but no + + align:start position:0% +it's hard to say yeah well no but no + + + align:start position:0% +it's hard to say yeah well no but no +here's the point this that's a great + + align:start position:0% +here's the point this that's a great + + + align:start position:0% +here's the point this that's a great +point which is that in some sense what + + align:start position:0% +point which is that in some sense what + + + align:start position:0% +point which is that in some sense what +the scalpers do is undo Adele's action + + align:start position:0% +the scalpers do is undo Adele's action + + + align:start position:0% +the scalpers do is undo Adele's action +and create a truly efficient market so + + align:start position:0% +and create a truly efficient market so + + + align:start position:0% +and create a truly efficient market so +think of the scalper says essentially + + align:start position:0% +think of the scalper says essentially + + + align:start position:0% +think of the scalper says essentially +undoing Adele's action which distorted + + align:start position:0% +undoing Adele's action which distorted + + + align:start position:0% +undoing Adele's action which distorted +the market so you have it you have a + + align:start position:0% +the market so you have it you have a + + + align:start position:0% +the market so you have it you have a +market for adele tickets which is an + + align:start position:0% +market for adele tickets which is an + + + align:start position:0% +market for adele tickets which is an +echo or $1500 adele tried to set a price + + align:start position:0% +echo or $1500 adele tried to set a price + + + align:start position:0% +echo or $1500 adele tried to set a price +ceiling at 150 seemingly selfishly + + align:start position:0% +ceiling at 150 seemingly selfishly + + + align:start position:0% +ceiling at 150 seemingly selfishly +saying look I'm willing to give up my + + align:start position:0% +saying look I'm willing to give up my + + + align:start position:0% +saying look I'm willing to give up my +surplus okay + + align:start position:0% +surplus okay + + + align:start position:0% +surplus okay +I'm for my for my fans but a force + + align:start position:0% +I'm for my for my fans but a force + + + align:start position:0% +I'm for my for my fans but a force +shouldn't work out that way what + + align:start position:0% +shouldn't work out that way what + + + align:start position:0% +shouldn't work out that way what +happened was the market recall but at + + align:start position:0% +happened was the market recall but at + + + align:start position:0% +happened was the market recall but at +1500 but that extra surplus didn't go to + + align:start position:0% +1500 but that extra surplus didn't go to + + + align:start position:0% +1500 but that extra surplus didn't go to +Adele the consumer surplus still + + align:start position:0% +Adele the consumer surplus still + + + align:start position:0% +Adele the consumer surplus still +remained above 1500 the difference was + + align:start position:0% +remained above 1500 the difference was + + + align:start position:0% +remained above 1500 the difference was +that extra gaped 150 and 1500 didn't go + + align:start position:0% +that extra gaped 150 and 1500 didn't go + + + align:start position:0% +that extra gaped 150 and 1500 didn't go +to dela went to the scalpers so it's + + align:start position:0% +to dela went to the scalpers so it's + + + align:start position:0% +to dela went to the scalpers so it's +probably more efficient than waiting on + + align:start position:0% +probably more efficient than waiting on + + + align:start position:0% +probably more efficient than waiting on +line because waiting in line has an + + align:start position:0% +line because waiting in line has an + + + align:start position:0% +line because waiting in line has an +efficiency where's this instantaneous + + align:start position:0% +efficiency where's this instantaneous + + + align:start position:0% +efficiency where's this instantaneous +bidding is more efficient but it in + + align:start position:0% +bidding is more efficient but it in + + + align:start position:0% +bidding is more efficient but it in +substance is delivering that if the + + align:start position:0% +substance is delivering that if the + + + align:start position:0% +substance is delivering that if the +efficiency gain is being delivered not + + align:start position:0% +efficiency gain is being delivered not + + + align:start position:0% +efficiency gain is being delivered not +to consumers as Adele wanted it's being + + align:start position:0% +to consumers as Adele wanted it's being + + + align:start position:0% +to consumers as Adele wanted it's being +delivered to scalpers okay so basically + + align:start position:0% +delivered to scalpers okay so basically + + + align:start position:0% +delivered to scalpers okay so basically +now there's another alternative + + align:start position:0% +now there's another alternative + + + align:start position:0% +now there's another alternative +what could the dell have done instead + + align:start position:0% +what could the dell have done instead + + + align:start position:0% +what could the dell have done instead +what what's what's another way adele + + align:start position:0% +what what's what's another way adele + + + align:start position:0% +what what's what's another way adele +could have approached this well she + + align:start position:0% +could have approached this well she + + + align:start position:0% +could have approached this well she +could have auctioned her tickets online + + align:start position:0% +could have auctioned her tickets online + + + align:start position:0% +could have auctioned her tickets online +she could have said look I know that I + + align:start position:0% +she could have said look I know that I + + + align:start position:0% +she could have said look I know that I +can't manage deliver $40 tickets to my + + align:start position:0% +can't manage deliver $40 tickets to my + + + align:start position:0% +can't manage deliver $40 tickets to my +fans + + align:start position:0% +fans + + + align:start position:0% +fans +it just can't defeat the scalping system + + align:start position:0% +it just can't defeat the scalping system + + + align:start position:0% +it just can't defeat the scalping system +but why so the scalpers have the money + + align:start position:0% +but why so the scalpers have the money + + + align:start position:0% +but why so the scalpers have the money +I'm gonna auction my tickets and + + align:start position:0% +I'm gonna auction my tickets and + + + align:start position:0% +I'm gonna auction my tickets and +essentially she could have set up an + + align:start position:0% +essentially she could have set up an + + + align:start position:0% +essentially she could have set up an +efficient market online we will bid and + + align:start position:0% +efficient market online we will bid and + + + align:start position:0% +efficient market online we will bid and +then you would have gotten the efficient + + align:start position:0% +then you would have gotten the efficient + + + align:start position:0% +then you would have gotten the efficient +outcome and you wouldn't wait online you + + align:start position:0% +outcome and you wouldn't wait online you + + + align:start position:0% +outcome and you wouldn't wait online you +would have bid now would have been + + align:start position:0% +would have bid now would have been + + + align:start position:0% +would have bid now would have been +inequitable outcome + + align:start position:0% +inequitable outcome + + + align:start position:0% +inequitable outcome +but basically the same fans would have + + align:start position:0% +but basically the same fans would have + + + align:start position:0% +but basically the same fans would have +gotten the tickets as in the end got + + align:start position:0% +gotten the tickets as in the end got + + + align:start position:0% +gotten the tickets as in the end got +them from the scalpers but instead it's + + align:start position:0% +them from the scalpers but instead it's + + + align:start position:0% +them from the scalpers but instead it's +paying 1500 to the scalpers unpaid 1500 + + align:start position:0% +paying 1500 to the scalpers unpaid 1500 + + + align:start position:0% +paying 1500 to the scalpers unpaid 1500 +to Adele and probably that's a better + + align:start position:0% +to Adele and probably that's a better + + + align:start position:0% +to Adele and probably that's a better +outcome I mean you know Adele doesn't + + align:start position:0% +outcome I mean you know Adele doesn't + + + align:start position:0% +outcome I mean you know Adele doesn't +need the money but at the end of the day + + align:start position:0% +need the money but at the end of the day + + + align:start position:0% +need the money but at the end of the day +if Adele's generating that amount of + + align:start position:0% +if Adele's generating that amount of + + + align:start position:0% +if Adele's generating that amount of +goodwill from her fans it seems like she + + align:start position:0% +goodwill from her fans it seems like she + + + align:start position:0% +goodwill from her fans it seems like she +should get the money not a bunch of + + align:start position:0% +should get the money not a bunch of + + + align:start position:0% +should get the money not a bunch of +scalpers okay so I guess probably rather + + align:start position:0% +scalpers okay so I guess probably rather + + + align:start position:0% +scalpers okay so I guess probably rather +have her have it than the scalpers now + + align:start position:0% +have her have it than the scalpers now + + + align:start position:0% +have her have it than the scalpers now +ticketmasters tried to set up auction + + align:start position:0% +ticketmasters tried to set up auction + + + align:start position:0% +ticketmasters tried to set up auction +systems recognizing this problem and + + align:start position:0% +systems recognizing this problem and + + + align:start position:0% +systems recognizing this problem and +they're not really taking off and it + + align:start position:0% +they're not really taking off and it + + + align:start position:0% +they're not really taking off and it +just it sort of speaks to the fact that + + align:start position:0% +just it sort of speaks to the fact that + + + align:start position:0% +just it sort of speaks to the fact that +people don't really like to think about + + align:start position:0% +people don't really like to think about + + + align:start position:0% +people don't really like to think about +economics okay so there was that + + align:start position:0% +economics okay so there was that + + + align:start position:0% +economics okay so there was that +basically people are like yeah but if + + align:start position:0% +basically people are like yeah but if + + + align:start position:0% +basically people are like yeah but if +you auction that's ripping off the fans + + align:start position:0% +you auction that's ripping off the fans + + + align:start position:0% +you auction that's ripping off the fans +that's no fair and say why should I say + + align:start position:0% +that's no fair and say why should I say + + + align:start position:0% +that's no fair and say why should I say +well you getting ripped off anyway just + + align:start position:0% +well you getting ripped off anyway just + + + align:start position:0% +well you getting ripped off anyway just +by scalpers and they said no I can still + + align:start position:0% +by scalpers and they said no I can still + + + align:start position:0% +by scalpers and they said no I can still +get online first and get my ticket and + + align:start position:0% +get online first and get my ticket and + + + align:start position:0% +get online first and get my ticket and +people just didn't like it thought it + + align:start position:0% +people just didn't like it thought it + + + align:start position:0% +people just didn't like it thought it +was unfair even though it's almost + + align:start position:0% +was unfair even though it's almost + + + align:start position:0% +was unfair even though it's almost +certainly a better outcome for society + + align:start position:0% +certainly a better outcome for society + + + align:start position:0% +certainly a better outcome for society +if they Goodell shut the money rabbin + + align:start position:0% +if they Goodell shut the money rabbin + + + align:start position:0% +if they Goodell shut the money rabbin +the scalpers which speaks the fact that + + align:start position:0% +the scalpers which speaks the fact that + + + align:start position:0% +the scalpers which speaks the fact that +you no morals matter in markets okay we + + align:start position:0% +you no morals matter in markets okay we + + + align:start position:0% +you no morals matter in markets okay we +like think of these markets abstract a + + align:start position:0% +like think of these markets abstract a + + + align:start position:0% +like think of these markets abstract a +moral concepts but morals do matter + + align:start position:0% +moral concepts but morals do matter + + + align:start position:0% +moral concepts but morals do matter +okay and that basically it's sort of + + align:start position:0% +okay and that basically it's sort of + + + align:start position:0% +okay and that basically it's sort of +matters you know you sometimes can't do + + align:start position:0% +matters you know you sometimes can't do + + + align:start position:0% +matters you know you sometimes can't do +the right thing because it might not be + + align:start position:0% +the right thing because it might not be + + + align:start position:0% +the right thing because it might not be +huh the thing that makes consumers + + align:start position:0% +huh the thing that makes consumers + + + align:start position:0% +huh the thing that makes consumers +willing to participate okay so that's + + align:start position:0% +willing to participate okay so that's + + + align:start position:0% +willing to participate okay so that's +one example scalping another example + + align:start position:0% +one example scalping another example + + + align:start position:0% +one example scalping another example +food banks okay food banks our + + align:start position:0% +food banks okay food banks our + + + align:start position:0% +food banks okay food banks our +organizations which are right oh yeah go + + align:start position:0% +organizations which are right oh yeah go + + + align:start position:0% +organizations which are right oh yeah go +ahead + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah I thought about that so in my if I + + align:start position:0% +yeah I thought about that so in my if I + + + align:start position:0% +yeah I thought about that so in my if I +could do anything I wanted in life I'd + + align:start position:0% +could do anything I wanted in life I'd + + + align:start position:0% +could do anything I wanted in life I'd +be a rock star and I thought if I was a + + align:start position:0% +be a rock star and I thought if I was a + + + align:start position:0% +be a rock star and I thought if I was a +rock star be cool I'd like have a + + align:start position:0% +rock star be cool I'd like have a + + + align:start position:0% +rock star be cool I'd like have a +concert for like my mega fans or like + + align:start position:0% +concert for like my mega fans or like + + + align:start position:0% +concert for like my mega fans or like +they'd have to prove who they were and I + + align:start position:0% +they'd have to prove who they were and I + + + align:start position:0% +they'd have to prove who they were and I +have a bracelet and stuff it just seems + + align:start position:0% +have a bracelet and stuff it just seems + + + align:start position:0% +have a bracelet and stuff it just seems +like it's too hard + + align:start position:0% +like it's too hard + + + align:start position:0% +like it's too hard +it seems the technology is just too hard + + align:start position:0% +it seems the technology is just too hard + + + align:start position:0% +it seems the technology is just too hard +so actually there's a really cool + + align:start position:0% +so actually there's a really cool + + + align:start position:0% +so actually there's a really cool +example that's on the phone this morning + + align:start position:0% +example that's on the phone this morning + + + align:start position:0% +example that's on the phone this morning +with a with a with a rock and roll + + align:start position:0% +with a with a with a rock and roll + + + align:start position:0% +with a with a with a rock and roll +promoter who's doing a super cool thing + + align:start position:0% +promoter who's doing a super cool thing + + + align:start position:0% +promoter who's doing a super cool thing +so as the election approaches I will nag + + align:start position:0% +so as the election approaches I will nag + + + align:start position:0% +so as the election approaches I will nag +you guys to vote voter turnout among the + + align:start position:0% +you guys to vote voter turnout among the + + + align:start position:0% +you guys to vote voter turnout among the +young is an enormous problem in the u.s. + + align:start position:0% +young is an enormous problem in the u.s. + + + align:start position:0% +young is an enormous problem in the u.s. +so she is running a series of concerts + + align:start position:0% +so she is running a series of concerts + + + align:start position:0% +so she is running a series of concerts +around the country where if you show a + + align:start position:0% +around the country where if you show a + + + align:start position:0% +around the country where if you show a +picture of yourself outside a polling + + align:start position:0% +picture of yourself outside a polling + + + align:start position:0% +picture of yourself outside a polling +place you get into the concert for free + + align:start position:0% +place you get into the concert for free + + + align:start position:0% +place you get into the concert for free +to try to promote voting among young + + align:start position:0% +to try to promote voting among young + + + align:start position:0% +to try to promote voting among young +people it's super cool it's called I + + align:start position:0% +people it's super cool it's called I + + + align:start position:0% +people it's super cool it's called I +voted you can look it up on the web it's + + align:start position:0% +voted you can look it up on the web it's + + + align:start position:0% +voted you can look it up on the web it's +kind of a cool thing there's a couple + + align:start position:0% +kind of a cool thing there's a couple + + + align:start position:0% +kind of a cool thing there's a couple +concerts here in Boston they're all over + + align:start position:0% +concerts here in Boston they're all over + + + align:start position:0% +concerts here in Boston they're all over +the country so you could think about + + align:start position:0% +the country so you could think about + + + align:start position:0% +the country so you could think about +things like that the question is + + align:start position:0% +things like that the question is + + + align:start position:0% +things like that the question is +ultimately you know two people + + align:start position:0% +ultimately you know two people + + + align:start position:0% +ultimately you know two people +photoshopped a picture from the polling + + align:start position:0% +photoshopped a picture from the polling + + + align:start position:0% +photoshopped a picture from the polling +place you know it's all it's it's just a + + align:start position:0% +place you know it's all it's it's just a + + + align:start position:0% +place you know it's all it's it's just a +question of enforcement okay so it's + + align:start position:0% +question of enforcement okay so it's + + + align:start position:0% +question of enforcement okay so it's +about food banks so basically um these + + align:start position:0% +about food banks so basically um these + + + align:start position:0% +about food banks so basically um these +are organizations provide free food to + + align:start position:0% +are organizations provide free food to + + + align:start position:0% +are organizations provide free food to +the poor and with the biggest one is + + align:start position:0% +the poor and with the biggest one is + + + align:start position:0% +the poor and with the biggest one is +called feeding America feeding America + + align:start position:0% +called feeding America feeding America + + + align:start position:0% +called feeding America feeding America +has food banks all over the nation and + + align:start position:0% +has food banks all over the nation and + + + align:start position:0% +has food banks all over the nation and +they provide free food free food to the + + align:start position:0% +they provide free food free food to the + + + align:start position:0% +they provide free food free food to the +poor okay + + align:start position:0% +poor okay + + + align:start position:0% +poor okay +now their goal then is they have to + + align:start position:0% +now their goal then is they have to + + + align:start position:0% +now their goal then is they have to +figure out where to send the food to get + + align:start position:0% +figure out where to send the food to get + + + align:start position:0% +figure out where to send the food to get +the people who need it the most + + align:start position:0% +the people who need it the most + + + align:start position:0% +the people who need it the most +now a market does this naturally + + align:start position:0% +now a market does this naturally + + + align:start position:0% +now a market does this naturally +basically if people want more Turkey in + + align:start position:0% +basically if people want more Turkey in + + + align:start position:0% +basically if people want more Turkey in +location a then also in the price for + + align:start position:0% +location a then also in the price for + + + align:start position:0% +location a then also in the price for +turkey goes up all of a sudden the store + + align:start position:0% +turkey goes up all of a sudden the store + + + align:start position:0% +turkey goes up all of a sudden the store +runs out of Turkey it says wow I can + + align:start position:0% +runs out of Turkey it says wow I can + + + align:start position:0% +runs out of Turkey it says wow I can +charge more for Turkey it raises the + + align:start position:0% +charge more for Turkey it raises the + + + align:start position:0% +charge more for Turkey it raises the +price and it a club relates the market + + align:start position:0% +price and it a club relates the market + + + align:start position:0% +price and it a club relates the market +so a market solves for sending the right + + align:start position:0% +so a market solves for sending the right + + + align:start position:0% +so a market solves for sending the right +food to where people want it but the + + align:start position:0% +food to where people want it but the + + + align:start position:0% +food to where people want it but the +problem with feeding America is that + + align:start position:0% +problem with feeding America is that + + + align:start position:0% +problem with feeding America is that +they didn't have that market so this had + + align:start position:0% +they didn't have that market so this had + + + align:start position:0% +they didn't have that market so this had +decide where to send stuff and they'd + + align:start position:0% +decide where to send stuff and they'd + + + align:start position:0% +decide where to send stuff and they'd +screw up they'd like to send potatoes to + + align:start position:0% +screw up they'd like to send potatoes to + + + align:start position:0% +screw up they'd like to send potatoes to +Idaho we're like they're drowning the + + align:start position:0% +Idaho we're like they're drowning the + + + align:start position:0% +Idaho we're like they're drowning the +potatoes stuff like that so it was very + + align:start position:0% +potatoes stuff like that so it was very + + + align:start position:0% +potatoes stuff like that so it was very +hard from the figure out where to send + + align:start position:0% +hard from the figure out where to send + + + align:start position:0% +hard from the figure out where to send +the food exactly what people wanted the + + align:start position:0% +the food exactly what people wanted the + + + align:start position:0% +the food exactly what people wanted the +most because they didn't have the market + + align:start position:0% +most because they didn't have the market + + + align:start position:0% +most because they didn't have the market +mechanism they want to give it away for + + align:start position:0% +mechanism they want to give it away for + + + align:start position:0% +mechanism they want to give it away for +free that sort of defeat the purse they + + align:start position:0% +free that sort of defeat the purse they + + + align:start position:0% +free that sort of defeat the purse they +charge for it but they didn't really + + align:start position:0% +charge for it but they didn't really + + + align:start position:0% +charge for it but they didn't really +know they didn't have the market to tell + + align:start position:0% +know they didn't have the market to tell + + + align:start position:0% +know they didn't have the market to tell +them where folks wanted which foods in + + align:start position:0% +them where folks wanted which foods in + + + align:start position:0% +them where folks wanted which foods in +the real market if you want real foods + + align:start position:0% +the real market if you want real foods + + + align:start position:0% +the real market if you want real foods +you bid the price up + + align:start position:0% +you bid the price up + + + align:start position:0% +you bid the price up +in their market you couldn't so feeding + + align:start position:0% +in their market you couldn't so feeding + + + align:start position:0% +in their market you couldn't so feeding +America came up with a really clever + + align:start position:0% +America came up with a really clever + + + align:start position:0% +America came up with a really clever +solution they made a virtual market they + + align:start position:0% +solution they made a virtual market they + + + align:start position:0% +solution they made a virtual market they +said to each food bank we are gonna give + + align:start position:0% +said to each food bank we are gonna give + + + align:start position:0% +said to each food bank we are gonna give +you a fake budget of X hundred thousands + + align:start position:0% +you a fake budget of X hundred thousands + + + align:start position:0% +you a fake budget of X hundred thousands +of dollars and you bid for which foods + + align:start position:0% +of dollars and you bid for which foods + + + align:start position:0% +of dollars and you bid for which foods +you want based on what the people in + + align:start position:0% +you want based on what the people in + + + align:start position:0% +you want based on what the people in +your area want and will then allocate it + + align:start position:0% +your area want and will then allocate it + + + align:start position:0% +your area want and will then allocate it +according to those bids so they got the + + align:start position:0% +according to those bids so they got the + + + align:start position:0% +according to those bids so they got the +market mechanism working without the + + align:start position:0% +market mechanism working without the + + + align:start position:0% +market mechanism working without the +food banks haven't actually give any + + align:start position:0% +food banks haven't actually give any + + + align:start position:0% +food banks haven't actually give any +money okay + + align:start position:0% +money okay + + + align:start position:0% +money okay +so in that way they massively + + align:start position:0% +so in that way they massively + + + align:start position:0% +so in that way they massively +reallocated food they suddenly said hey + + align:start position:0% +reallocated food they suddenly said hey + + + align:start position:0% +reallocated food they suddenly said hey +the one from Idaho is bidding really + + align:start position:0% +the one from Idaho is bidding really + + + align:start position:0% +the one from Idaho is bidding really +high for Turkey and not all for potatoes + + align:start position:0% +high for Turkey and not all for potatoes + + + align:start position:0% +high for Turkey and not all for potatoes +maybe we should send them more turkey + + align:start position:0% +maybe we should send them more turkey + + + align:start position:0% +maybe we should send them more turkey +and seven potatoes elsewhere so they + + align:start position:0% +and seven potatoes elsewhere so they + + + align:start position:0% +and seven potatoes elsewhere so they +essentially got market signals from a + + align:start position:0% +essentially got market signals from a + + + align:start position:0% +essentially got market signals from a +non financial transaction it was super + + align:start position:0% +non financial transaction it was super + + + align:start position:0% +non financial transaction it was super +cool idea and the amount of and there + + align:start position:0% +cool idea and the amount of and there + + + align:start position:0% +cool idea and the amount of and there +was a huge benefit they were able to + + align:start position:0% +was a huge benefit they were able to + + + align:start position:0% +was a huge benefit they were able to +effectively allocate about 50 million + + align:start position:0% +effectively allocate about 50 million + + + align:start position:0% +effectively allocate about 50 million +pounds of food through this mechanism + + align:start position:0% +pounds of food through this mechanism + + + align:start position:0% +pounds of food through this mechanism +making sure that food got to the folks + + align:start position:0% +making sure that food got to the folks + + + align:start position:0% +making sure that food got to the folks +that needed it so there's an example you + + align:start position:0% +that needed it so there's an example you + + + align:start position:0% +that needed it so there's an example you +can use a market mechanism without + + align:start position:0% +can use a market mechanism without + + + align:start position:0% +can use a market mechanism without +actually while while not violating + + align:start position:0% +actually while while not violating + + + align:start position:0% +actually while while not violating +equity the food was always free but if I + + align:start position:0% +equity the food was always free but if I + + + align:start position:0% +equity the food was always free but if I +set up these virtual prices they managed + + align:start position:0% +set up these virtual prices they managed + + + align:start position:0% +set up these virtual prices they managed +to get the food delivered to where + + align:start position:0% +to get the food delivered to where + + + align:start position:0% +to get the food delivered to where +people who want the most they let the + + align:start position:0% +people who want the most they let the + + + align:start position:0% +people who want the most they let the +market send its allocated signals they + + align:start position:0% +market send its allocated signals they + + + align:start position:0% +market send its allocated signals they +let the market be allocated li efficient + + align:start position:0% +let the market be allocated li efficient + + + align:start position:0% +let the market be allocated li efficient +sent signals of where people wanted the + + align:start position:0% +sent signals of where people wanted the + + + align:start position:0% +sent signals of where people wanted the +food without actually violating equity + + align:start position:0% +food without actually violating equity + + + align:start position:0% +food without actually violating equity +okay + + align:start position:0% +okay + + + align:start position:0% +okay +questions about that okay now let's go + + align:start position:0% +questions about that okay now let's go + + + align:start position:0% +questions about that okay now let's go +to the hardest but my favorite example + + align:start position:0% +to the hardest but my favorite example + + + align:start position:0% +to the hardest but my favorite example +which is taxi medallions this is a hard + + align:start position:0% +which is taxi medallions this is a hard + + + align:start position:0% +which is taxi medallions this is a hard +example but it's a really cool one and + + align:start position:0% +example but it's a really cool one and + + + align:start position:0% +example but it's a really cool one and +it ends with a great story okay taxi + + align:start position:0% +it ends with a great story okay taxi + + + align:start position:0% +it ends with a great story okay taxi +cabs now cast your mind back pre ubirr + + align:start position:0% +cabs now cast your mind back pre ubirr + + + align:start position:0% +cabs now cast your mind back pre ubirr +okay go back ten years about ten years + + align:start position:0% +okay go back ten years about ten years + + + align:start position:0% +okay go back ten years about ten years +taxi cabs were the only way you could + + align:start position:0% +taxi cabs were the only way you could + + + align:start position:0% +taxi cabs were the only way you could +get around town if you didn't have you + + align:start position:0% +get around town if you didn't have you + + + align:start position:0% +get around town if you didn't have you +know if you want to get from one eighty + + align:start position:0% +know if you want to get from one eighty + + + align:start position:0% +know if you want to get from one eighty +point be in a car you known one you took + + align:start position:0% +point be in a car you known one you took + + + align:start position:0% +point be in a car you known one you took +a taxi okay and this was a great example + + align:start position:0% +a taxi okay and this was a great example + + + align:start position:0% +a taxi okay and this was a great example +of an economist perfectly competitive + + align:start position:0% +of an economist perfectly competitive + + + align:start position:0% +of an economist perfectly competitive +market in theory it's the identical + + align:start position:0% +market in theory it's the identical + + + align:start position:0% +market in theory it's the identical +product you want to go from point A to + + align:start position:0% +product you want to go from point A to + + + align:start position:0% +product you want to go from point A to +point B okay + + align:start position:0% +point B okay + + + align:start position:0% +point B okay +it's very there's could be lots of them + + align:start position:0% +it's very there's could be lots of them + + + align:start position:0% +it's very there's could be lots of them +are riding around the streets you can + + align:start position:0% +are riding around the streets you can + + + align:start position:0% +are riding around the streets you can +price compare because cabs are coming by + + align:start position:0% +price compare because cabs are coming by + + + align:start position:0% +price compare because cabs are coming by +all the + + align:start position:0% +all the + + + align:start position:0% +all the +I'm okay it should have been a very + + align:start position:0% +I'm okay it should have been a very + + + align:start position:0% +I'm okay it should have been a very +effective perfectly efficient perfectly + + align:start position:0% +effective perfectly efficient perfectly + + + align:start position:0% +effective perfectly efficient perfectly +competitive market okay but it wasn't + + align:start position:0% +competitive market okay but it wasn't + + + align:start position:0% +competitive market okay but it wasn't +because every city limited the amount of + + align:start position:0% +because every city limited the amount of + + + align:start position:0% +because every city limited the amount of +taxicabs that were allowed in their city + + align:start position:0% +taxicabs that were allowed in their city + + + align:start position:0% +taxicabs that were allowed in their city +every city had a system where to be a + + align:start position:0% +every city had a system where to be a + + + align:start position:0% +every city had a system where to be a +taxicab you had to have what was called + + align:start position:0% +taxicab you had to have what was called + + + align:start position:0% +taxicab you had to have what was called +the medallion rather than really + + align:start position:0% +the medallion rather than really + + + align:start position:0% +the medallion rather than really +Manhattan's if its original Medina is + + align:start position:0% +Manhattan's if its original Medina is + + + align:start position:0% +Manhattan's if its original Medina is +there's a piece of paper actually and + + align:start position:0% +there's a piece of paper actually and + + + align:start position:0% +there's a piece of paper actually and +they regulated the number of taxicabs + + align:start position:0% +they regulated the number of taxicabs + + + align:start position:0% +they regulated the number of taxicabs +allowed in the city they said we're only + + align:start position:0% +allowed in the city they said we're only + + + align:start position:0% +allowed in the city they said we're only +going to allow X many taxicab drivers in + + align:start position:0% +going to allow X many taxicab drivers in + + + align:start position:0% +going to allow X many taxicab drivers in +the city in every city did this now + + align:start position:0% +the city in every city did this now + + + align:start position:0% +the city in every city did this now +we're gonna do both a positive and + + align:start position:0% +we're gonna do both a positive and + + + align:start position:0% +we're gonna do both a positive and +normative analysis of this policy let's + + align:start position:0% +normative analysis of this policy let's + + + align:start position:0% +normative analysis of this policy let's +start with a positive analysis what did + + align:start position:0% +start with a positive analysis what did + + + align:start position:0% +start with a positive analysis what did +this polity jit policy do okay now I'm + + align:start position:0% +this polity jit policy do okay now I'm + + + align:start position:0% +this polity jit policy do okay now I'm +gonna go figure 10 for figure 10 four + + align:start position:0% +gonna go figure 10 for figure 10 four + + + align:start position:0% +gonna go figure 10 for figure 10 four +will be one of the most complicated + + align:start position:0% +will be one of the most complicated + + + align:start position:0% +will be one of the most complicated +figures doing this class so I'm gonna go + + align:start position:0% +figures doing this class so I'm gonna go + + + align:start position:0% +figures doing this class so I'm gonna go +through two slowly as I can but please + + align:start position:0% +through two slowly as I can but please + + + align:start position:0% +through two slowly as I can but please +stop me if it's not clear okay this one + + align:start position:0% +stop me if it's not clear okay this one + + + align:start position:0% +stop me if it's not clear okay this one +of these figures will go back and forth + + align:start position:0% +of these figures will go back and forth + + + align:start position:0% +of these figures will go back and forth +between the two sides so on the right + + align:start position:0% +between the two sides so on the right + + + align:start position:0% +between the two sides so on the right +hand side is the market on the left hand + + align:start position:0% +hand side is the market on the left hand + + + align:start position:0% +hand side is the market on the left hand +side as a cab firm we're gonna start by + + align:start position:0% +side as a cab firm we're gonna start by + + + align:start position:0% +side as a cab firm we're gonna start by +assuming all cabs are identical we + + align:start position:0% +assuming all cabs are identical we + + + align:start position:0% +assuming all cabs are identical we +assume all cabs are identical so one + + align:start position:0% +assume all cabs are identical so one + + + align:start position:0% +assume all cabs are identical so one +representative firm tells us about every + + align:start position:0% +representative firm tells us about every + + + align:start position:0% +representative firm tells us about every +cat firm okay now we start with the + + align:start position:0% +cat firm okay now we start with the + + + align:start position:0% +cat firm okay now we start with the +market we have an initial demand which + + align:start position:0% +market we have an initial demand which + + + align:start position:0% +market we have an initial demand which +is d the line d the blue line is the + + align:start position:0% +is d the line d the blue line is the + + + align:start position:0% +is d the line d the blue line is the +demand for taxi cabs okay an initial + + align:start position:0% +demand for taxi cabs okay an initial + + + align:start position:0% +demand for taxi cabs okay an initial +supply curve s1 we're gonna assume that + + align:start position:0% +supply curve s1 we're gonna assume that + + + align:start position:0% +supply curve s1 we're gonna assume that +essentially in a perfectly competitive + + align:start position:0% +essentially in a perfectly competitive + + + align:start position:0% +essentially in a perfectly competitive +market you have a flat long run supply + + align:start position:0% +market you have a flat long run supply + + + align:start position:0% +market you have a flat long run supply +curve your perfectly elastic supply okay + + align:start position:0% +curve your perfectly elastic supply okay + + + align:start position:0% +curve your perfectly elastic supply okay +anybody can just grab a cab and starts + + align:start position:0% +anybody can just grab a cab and starts + + + align:start position:0% +anybody can just grab a cab and starts +right what's getting in a cab burger + + align:start position:0% +right what's getting in a cab burger + + + align:start position:0% +right what's getting in a cab burger +without medallions anyone could throw + + align:start position:0% +without medallions anyone could throw + + + align:start position:0% +without medallions anyone could throw +can throw a taxi sign in the car so + + align:start position:0% +can throw a taxi sign in the car so + + + align:start position:0% +can throw a taxi sign in the car so +drive we're not picking people up okay + + align:start position:0% +drive we're not picking people up okay + + + align:start position:0% +drive we're not picking people up okay +so it's effectively perfectly + + align:start position:0% +so it's effectively perfectly + + + align:start position:0% +so it's effectively perfectly +entry-and-exit so it's a perfectly + + align:start position:0% +entry-and-exit so it's a perfectly + + + align:start position:0% +entry-and-exit so it's a perfectly +competitive long run market therefore + + align:start position:0% +competitive long run market therefore + + + align:start position:0% +competitive long run market therefore +flat supply that's one so our initial + + align:start position:0% +flat supply that's one so our initial + + + align:start position:0% +flat supply that's one so our initial +equilibrium is that point big e one okay + + align:start position:0% +equilibrium is that point big e one okay + + + align:start position:0% +equilibrium is that point big e one okay +when you have q1 rides big q1 rides per + + align:start position:0% +when you have q1 rides big q1 rides per + + + align:start position:0% +when you have q1 rides big q1 rides per +month and that amounts to so so you have + + align:start position:0% +month and that amounts to so so you have + + + align:start position:0% +month and that amounts to so so you have +Q that's the equilibrium now how many + + align:start position:0% +Q that's the equilibrium now how many + + + align:start position:0% +Q that's the equilibrium now how many +firms are there well we know any firms + + align:start position:0% +firms are there well we know any firms + + + align:start position:0% +firms are there well we know any firms +there are because we say okay at that + + align:start position:0% +there are because we say okay at that + + + align:start position:0% +there are because we say okay at that +price p1 we go to the left + + align:start position:0% +price p1 we go to the left + + + align:start position:0% +price p1 we go to the left +we know that firms will produce where + + align:start position:0% +we know that firms will produce where + + + align:start position:0% +we know that firms will produce where +marginal cost equals average + + align:start position:0% +marginal cost equals average + + + align:start position:0% +marginal cost equals average +that the minimum of long-run average + + align:start position:0% +that the minimum of long-run average + + + align:start position:0% +that the minimum of long-run average +cost we proved that a couple lectures + + align:start position:0% +cost we proved that a couple lectures + + + align:start position:0% +cost we proved that a couple lectures +ago + + align:start position:0% +ago + + + align:start position:0% +ago +therefore if the price is a 1 we know + + align:start position:0% +therefore if the price is a 1 we know + + + align:start position:0% +therefore if the price is a 1 we know +each efficient firm will produce little + + align:start position:0% +each efficient firm will produce little + + + align:start position:0% +each efficient firm will produce little +q1 if there's if each firms could reduce + + align:start position:0% +q1 if there's if each firms could reduce + + + align:start position:0% +q1 if there's if each firms could reduce +a little q1 and the total amount of + + align:start position:0% +a little q1 and the total amount of + + + align:start position:0% +a little q1 and the total amount of +rides is gonna be big q1 then that + + align:start position:0% +rides is gonna be big q1 then that + + + align:start position:0% +rides is gonna be big q1 then that +implies little n1 firms so let me go + + align:start position:0% +implies little n1 firms so let me go + + + align:start position:0% +implies little n1 firms so let me go +through it again supply equals demand a + + align:start position:0% +through it again supply equals demand a + + + align:start position:0% +through it again supply equals demand a +big Q one that gives you a price P one + + align:start position:0% +big Q one that gives you a price P one + + + align:start position:0% +big Q one that gives you a price P one +now we shift to the left at that price P + + align:start position:0% +now we shift to the left at that price P + + + align:start position:0% +now we shift to the left at that price P +1 we know that each firm will choose to + + align:start position:0% +1 we know that each firm will choose to + + + align:start position:0% +1 we know that each firm will choose to +produce little q1 rides because that's + + align:start position:0% +produce little q1 rides because that's + + + align:start position:0% +produce little q1 rides because that's +where price equals marginal cost equals + + align:start position:0% +where price equals marginal cost equals + + + align:start position:0% +where price equals marginal cost equals +average cost now we go back to the right + + align:start position:0% +average cost now we go back to the right + + + align:start position:0% +average cost now we go back to the right +we know if this little each firms racing + + align:start position:0% +we know if this little each firms racing + + + align:start position:0% +we know if this little each firms racing +little q1 rides and you need big q1 then + + align:start position:0% +little q1 rides and you need big q1 then + + + align:start position:0% +little q1 rides and you need big q1 then +there must be n1 firms ok questions + + align:start position:0% +there must be n1 firms ok questions + + + align:start position:0% +there must be n1 firms ok questions +about that that's the initial + + align:start position:0% +about that that's the initial + + + align:start position:0% +about that that's the initial +equilibrium okay and at that point there + + align:start position:0% +equilibrium okay and at that point there + + + align:start position:0% +equilibrium okay and at that point there +are long-run zero profits consumer + + align:start position:0% +are long-run zero profits consumer + + + align:start position:0% +are long-run zero profits consumer +surplus is a plus B plus both seat bus C + + align:start position:0% +surplus is a plus B plus both seat bus C + + + align:start position:0% +surplus is a plus B plus both seat bus C +C by the way is the gray area on either + + align:start position:0% +C by the way is the gray area on either + + + align:start position:0% +C by the way is the gray area on either +side of the dash line a plus B plus C + + align:start position:0% +side of the dash line a plus B plus C + + + align:start position:0% +side of the dash line a plus B plus C +we'd mark it twice because it's + + align:start position:0% +we'd mark it twice because it's + + + align:start position:0% +we'd mark it twice because it's +confusing the dashed line there so the + + align:start position:0% +confusing the dashed line there so the + + + align:start position:0% +confusing the dashed line there so the +blue area of the green area in the gray + + align:start position:0% +blue area of the green area in the gray + + + align:start position:0% +blue area of the green area in the gray +area are the consumer surplus and what's + + align:start position:0% +area are the consumer surplus and what's + + + align:start position:0% +area are the consumer surplus and what's +the producer surplus + + align:start position:0% +the producer surplus + + + align:start position:0% +the producer surplus +what's the Bri surplus raise your hand + + align:start position:0% +what's the Bri surplus raise your hand + + + align:start position:0% +what's the Bri surplus raise your hand +and tell me yeah zero because yeah + + align:start position:0% +and tell me yeah zero because yeah + + + align:start position:0% +and tell me yeah zero because yeah +there's no it's in long run equilibrium + + align:start position:0% +there's no it's in long run equilibrium + + + align:start position:0% +there's no it's in long run equilibrium +there's no profits in long run person + + align:start position:0% +there's no profits in long run person + + + align:start position:0% +there's no profits in long run person +kinetic the Librium price remember + + align:start position:0% +kinetic the Librium price remember + + + align:start position:0% +kinetic the Librium price remember +profits are price minus average cost but + + align:start position:0% +profits are price minus average cost but + + + align:start position:0% +profits are price minus average cost but +price equals average cost okay so + + align:start position:0% +price equals average cost okay so + + + align:start position:0% +price equals average cost okay so +there's no profit so it's all consumer + + align:start position:0% +there's no profit so it's all consumer + + + align:start position:0% +there's no profit so it's all consumer +surplus all well and good now let's say + + align:start position:0% +surplus all well and good now let's say + + + align:start position:0% +surplus all well and good now let's say +the government comes in and says we're + + align:start position:0% +the government comes in and says we're + + + align:start position:0% +the government comes in and says we're +gonna have a medallion system + + align:start position:0% +gonna have a medallion system + + + align:start position:0% +gonna have a medallion system +okay + + align:start position:0% + + + + align:start position:0% + +so let's so let's say um we're gonna + + align:start position:0% +so let's so let's say um we're gonna + + + align:start position:0% +so let's so let's say um we're gonna +wait a minute system we're gonna have a + + align:start position:0% +wait a minute system we're gonna have a + + + align:start position:0% +wait a minute system we're gonna have a +system where only the little N two cabs + + align:start position:0% +system where only the little N two cabs + + + align:start position:0% +system where only the little N two cabs +are allowed in the market little n 2 are + + align:start position:0% +are allowed in the market little n 2 are + + + align:start position:0% +are allowed in the market little n 2 are +the only number of cabs allowed in the + + align:start position:0% +the only number of cabs allowed in the + + + align:start position:0% +the only number of cabs allowed in the +market okay so what is the new market + + align:start position:0% +market okay so what is the new market + + + align:start position:0% +market okay so what is the new market +supply curve start on the right what's + + align:start position:0% +supply curve start on the right what's + + + align:start position:0% +supply curve start on the right what's +do the market supply curve well up to + + align:start position:0% +do the market supply curve well up to + + + align:start position:0% +do the market supply curve well up to +little n 2 times Q 1 nothing's changed + + align:start position:0% +little n 2 times Q 1 nothing's changed + + + align:start position:0% +little n 2 times Q 1 nothing's changed +each cab company used to provide Q what + + align:start position:0% +each cab company used to provide Q what + + + align:start position:0% +each cab company used to provide Q what +little Q 1 rides at a price P 1 so up to + + align:start position:0% +little Q 1 rides at a price P 1 so up to + + + align:start position:0% +little Q 1 rides at a price P 1 so up to +the point little and too little Q 1 + + align:start position:0% +the point little and too little Q 1 + + + align:start position:0% +the point little and too little Q 1 +we're on the same supply curve we used + + align:start position:0% +we're on the same supply curve we used + + + align:start position:0% +we're on the same supply curve we used +to be on but then things change why do + + align:start position:0% +to be on but then things change why do + + + align:start position:0% +to be on but then things change why do +they change because now let's say riders + + align:start position:0% +they change because now let's say riders + + + align:start position:0% +they change because now let's say riders +want more than little n 2 Q 1 + + align:start position:0% +want more than little n 2 Q 1 + + + align:start position:0% +want more than little n 2 Q 1 +well you can't deal with that by entry + + align:start position:0% +well you can't deal with that by entry + + + align:start position:0% +well you can't deal with that by entry +you have to deal with that by the + + align:start position:0% +you have to deal with that by the + + + align:start position:0% +you have to deal with that by the +existing cab drivers working more but if + + align:start position:0% +existing cab drivers working more but if + + + align:start position:0% +existing cab drivers working more but if +they work more supply curve is upward + + align:start position:0% +they work more supply curve is upward + + + align:start position:0% +they work more supply curve is upward +sloping because now marginal costs can + + align:start position:0% +sloping because now marginal costs can + + + align:start position:0% +sloping because now marginal costs can +be rising before the resupply curve was + + align:start position:0% +be rising before the resupply curve was + + + align:start position:0% +be rising before the resupply curve was +flat is when you went to the right of + + align:start position:0% +flat is when you went to the right of + + + align:start position:0% +flat is when you went to the right of +little and to little Q 1 as you move to + + align:start position:0% +little and to little Q 1 as you move to + + + align:start position:0% +little and to little Q 1 as you move to +the right + + align:start position:0% +the right + + + align:start position:0% +the right +you just got more entering and everyone + + align:start position:0% +you just got more entering and everyone + + + align:start position:0% +you just got more entering and everyone +still produces their efficient level of + + align:start position:0% +still produces their efficient level of + + + align:start position:0% +still produces their efficient level of +little Q 1 now when you can't allow more + + align:start position:0% +little Q 1 now when you can't allow more + + + align:start position:0% +little Q 1 now when you can't allow more +entry firms have to produce more and + + align:start position:0% +entry firms have to produce more and + + + align:start position:0% +entry firms have to produce more and +suddenly they're not at the cost + + align:start position:0% +suddenly they're not at the cost + + + align:start position:0% +suddenly they're not at the cost +minimizing point they're riding up their + + align:start position:0% +minimizing point they're riding up their + + + align:start position:0% +minimizing point they're riding up their +marginal cost curve so the supply curve + + align:start position:0% +marginal cost curve so the supply curve + + + align:start position:0% +marginal cost curve so the supply curve +becomes flat to that point and then + + align:start position:0% +becomes flat to that point and then + + + align:start position:0% +becomes flat to that point and then +becomes upward sloping and that's s2 s2 + + align:start position:0% +becomes upward sloping and that's s2 s2 + + + align:start position:0% +becomes upward sloping and that's s2 s2 +is the red line that is flat to the left + + align:start position:0% +is the red line that is flat to the left + + + align:start position:0% +is the red line that is flat to the left +of n little n to little Q 1 and then + + align:start position:0% +of n little n to little Q 1 and then + + + align:start position:0% +of n little n to little Q 1 and then +becomes Verbeek um ZUP words sloping and + + align:start position:0% +becomes Verbeek um ZUP words sloping and + + + align:start position:0% +becomes Verbeek um ZUP words sloping and +the new equilibrium is that point e 2 + + align:start position:0% +the new equilibrium is that point e 2 + + + align:start position:0% +the new equilibrium is that point e 2 +with n 2 firms by law you can only then + + align:start position:0% +with n 2 firms by law you can only then + + + align:start position:0% +with n 2 firms by law you can only then +two firms pricing little Q two rides + + align:start position:0% +two firms pricing little Q two rides + + + align:start position:0% +two firms pricing little Q two rides +each okay and your new equilibrium is + + align:start position:0% +each okay and your new equilibrium is + + + align:start position:0% +each okay and your new equilibrium is +big Q 2 and that new equilibrium price + + align:start position:0% +big Q 2 and that new equilibrium price + + + align:start position:0% +big Q 2 and that new equilibrium price +is the new equilibrium price is P 2 the + + align:start position:0% +is the new equilibrium price is P 2 the + + + align:start position:0% +is the new equilibrium price is P 2 the +director over in price is P 2 okay now P + + align:start position:0% +director over in price is P 2 okay now P + + + align:start position:0% +director over in price is P 2 okay now P +2 if you go to the old um P 2 is the + + align:start position:0% +2 if you go to the old um P 2 is the + + + align:start position:0% +2 if you go to the old um P 2 is the +point if you look at the prices P 2 but + + align:start position:0% +point if you look at the prices P 2 but + + + align:start position:0% +point if you look at the prices P 2 but +I forget the AC 2 curve focus on the AC + + align:start position:0% +I forget the AC 2 curve focus on the AC + + + align:start position:0% +I forget the AC 2 curve focus on the AC +1 curve + + align:start position:0% +1 curve + + + align:start position:0% +1 curve +okay average the average cost function + + align:start position:0% +okay average the average cost function + + + align:start position:0% +okay average the average cost function +hasn't changed it's still a c1 so if + + align:start position:0% +hasn't changed it's still a c1 so if + + + align:start position:0% +hasn't changed it's still a c1 so if +their price is p2 and their average cost + + align:start position:0% +their price is p2 and their average cost + + + align:start position:0% +their price is p2 and their average cost +curve is a c1 there could produce where + + align:start position:0% +curve is a c1 there could produce where + + + align:start position:0% +curve is a c1 there could produce where +price equals marginal cost at little e2 + + align:start position:0% +price equals marginal cost at little e2 + + + align:start position:0% +price equals marginal cost at little e2 +okay so let me back up you have let's go + + align:start position:0% +okay so let me back up you have let's go + + + align:start position:0% +okay so let me back up you have let's go +back to the front curve on the right the + + align:start position:0% +back to the front curve on the right the + + + align:start position:0% +back to the front curve on the right the +equilibrium is not Big E - that's sort + + align:start position:0% +equilibrium is not Big E - that's sort + + + align:start position:0% +equilibrium is not Big E - that's sort +of priced a little P - now shift to the + + align:start position:0% +of priced a little P - now shift to the + + + align:start position:0% +of priced a little P - now shift to the +left at a price of little P - firms + + align:start position:0% +left at a price of little P - firms + + + align:start position:0% +left at a price of little P - firms +produce where price equals marginal cost + + align:start position:0% +produce where price equals marginal cost + + + align:start position:0% +produce where price equals marginal cost +right price equals marginal cost at a + + align:start position:0% +right price equals marginal cost at a + + + align:start position:0% +right price equals marginal cost at a +quantity little Q - so firms produce a + + align:start position:0% +quantity little Q - so firms produce a + + + align:start position:0% +quantity little Q - so firms produce a +little Q - because that's the point at + + align:start position:0% +little Q - because that's the point at + + + align:start position:0% +little Q - because that's the point at +which price equals marginal cost + + align:start position:0% +which price equals marginal cost + + + align:start position:0% +which price equals marginal cost +they produce it a little Q - well if + + align:start position:0% +they produce it a little Q - well if + + + align:start position:0% +they produce it a little Q - well if +they're making little Q two units at a + + align:start position:0% +they're making little Q two units at a + + + align:start position:0% +they're making little Q two units at a +price P - they're earning profits of Pi + + align:start position:0% +price P - they're earning profits of Pi + + + align:start position:0% +price P - they're earning profits of Pi +the shaded area because they are + + align:start position:0% +the shaded area because they are + + + align:start position:0% +the shaded area because they are +producing units at price above marginal + + align:start position:0% +producing units at price above marginal + + + align:start position:0% +producing units at price above marginal +cost and they're producing little Q two + + align:start position:0% +cost and they're producing little Q two + + + align:start position:0% +cost and they're producing little Q two +units so every unit they produce turning + + align:start position:0% +units so every unit they produce turning + + + align:start position:0% +units so every unit they produce turning +profits on so the taxi medallion workers + + align:start position:0% +profits on so the taxi medallion workers + + + align:start position:0% +profits on so the taxi medallion workers +are the taxi companies are now making + + align:start position:0% +are the taxi companies are now making + + + align:start position:0% +are the taxi companies are now making +money they're making profits okay + + align:start position:0% +money they're making profits okay + + + align:start position:0% +money they're making profits okay +questions about that yeah they're making + + align:start position:0% +questions about that yeah they're making + + + align:start position:0% +questions about that yeah they're making +profits so imagine where we started at E + + align:start position:0% +profits so imagine where we started at E + + + align:start position:0% +profits so imagine where we started at E +- in allowed free entry then you'd see + + align:start position:0% +- in allowed free entry then you'd see + + + align:start position:0% +- in allowed free entry then you'd see +basically more firms whenever you drive + + align:start position:0% +basically more firms whenever you drive + + + align:start position:0% +basically more firms whenever you drive +the price down to p1 but we don't allow + + align:start position:0% +the price down to p1 but we don't allow + + + align:start position:0% +the price down to p1 but we don't allow +that + + align:start position:0% +that + + + align:start position:0% +that +so there's profits it's a barrier to + + align:start position:0% +so there's profits it's a barrier to + + + align:start position:0% +so there's profits it's a barrier to +entry which creates profits which breaks + + align:start position:0% +entry which creates profits which breaks + + + align:start position:0% +entry which creates profits which breaks +us from our long-run flat supply curve + + align:start position:0% +us from our long-run flat supply curve + + + align:start position:0% +us from our long-run flat supply curve +we talked about one of the reasons why + + align:start position:0% +we talked about one of the reasons why + + + align:start position:0% +we talked about one of the reasons why +that loop will be flat so now let's move + + align:start position:0% +that loop will be flat so now let's move + + + align:start position:0% +that loop will be flat so now let's move +to the normative is this a good idea or + + align:start position:0% +to the normative is this a good idea or + + + align:start position:0% +to the normative is this a good idea or +not well let's look at the welfare + + align:start position:0% +not well let's look at the welfare + + + align:start position:0% +not well let's look at the welfare +implications what's happened what's + + align:start position:0% +implications what's happened what's + + + align:start position:0% +implications what's happened what's +happened is consumers used to have a + + align:start position:0% +happened is consumers used to have a + + + align:start position:0% +happened is consumers used to have a +surplus a plus B plus C now their + + align:start position:0% +surplus a plus B plus C now their + + + align:start position:0% +surplus a plus B plus C now their +surplus is what what's to do consumer + + align:start position:0% +surplus is what what's to do consumer + + + align:start position:0% +surplus is what what's to do consumer +surplus raise their hand and tell me + + align:start position:0% +surplus raise their hand and tell me + + + align:start position:0% +surplus raise their hand and tell me +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +just a because the line below the demand + + align:start position:0% +just a because the line below the demand + + + align:start position:0% +just a because the line below the demand +above price is just a producer's used to + + align:start position:0% +above price is just a producer's used to + + + align:start position:0% +above price is just a producer's used to +have zero surplus what's their new + + align:start position:0% +have zero surplus what's their new + + + align:start position:0% +have zero surplus what's their new +surplus behind you yeah B because it's + + align:start position:0% +surplus behind you yeah B because it's + + + align:start position:0% +surplus behind you yeah B because it's +the area above the supply curve below + + align:start position:0% +the area above the supply curve below + + + align:start position:0% +the area above the supply curve below +the price line and C is what the + + align:start position:0% +the price line and C is what the + + + align:start position:0% +the price line and C is what the +deadweight loss + + align:start position:0% +deadweight loss + + + align:start position:0% +deadweight loss +those the transactions no longer + + align:start position:0% +those the transactions no longer + + + align:start position:0% +those the transactions no longer +happening okay + + align:start position:0% +happening okay + + + align:start position:0% +happening okay +the deadweight loss okay so basically + + align:start position:0% +the deadweight loss okay so basically + + + align:start position:0% +the deadweight loss okay so basically +normatively you can pose the problem as + + align:start position:0% +normatively you can pose the problem as + + + align:start position:0% +normatively you can pose the problem as +the following is it worth society losing + + align:start position:0% +the following is it worth society losing + + + align:start position:0% +the following is it worth society losing +the area see in order to transfer the + + align:start position:0% +the area see in order to transfer the + + + align:start position:0% +the area see in order to transfer the +area be from consumers to taxicab + + align:start position:0% +area be from consumers to taxicab + + + align:start position:0% +area be from consumers to taxicab +drivers that's the way to think about + + align:start position:0% +drivers that's the way to think about + + + align:start position:0% +drivers that's the way to think about +this problem we say it again it's very + + align:start position:0% +this problem we say it again it's very + + + align:start position:0% +this problem we say it again it's very +important central the government policy + + align:start position:0% +important central the government policy + + + align:start position:0% +important central the government policy +doing is saying I'm going to transfer be + + align:start position:0% +doing is saying I'm going to transfer be + + + align:start position:0% +doing is saying I'm going to transfer be +from consumers to producers even though + + align:start position:0% +from consumers to producers even though + + + align:start position:0% +from consumers to producers even though +it's gonna cost me see and deadweight + + align:start position:0% +it's gonna cost me see and deadweight + + + align:start position:0% +it's gonna cost me see and deadweight +loss that's what the government's saying + + align:start position:0% +loss that's what the government's saying + + + align:start position:0% +loss that's what the government's saying +that's the government's position okay + + align:start position:0% +that's the government's position okay + + + align:start position:0% +that's the government's position okay +now why is the government wrong why in + + align:start position:0% +now why is the government wrong why in + + + align:start position:0% +now why is the government wrong why in +fact is that not the proper statement of + + align:start position:0% +fact is that not the proper statement of + + + align:start position:0% +fact is that not the proper statement of +what happens it's very complicated what + + align:start position:0% +what happens it's very complicated what + + + align:start position:0% +what happens it's very complicated what +is the government miss when it says hey + + align:start position:0% +is the government miss when it says hey + + + align:start position:0% +is the government miss when it says hey +look I've made the drivers better off + + align:start position:0% +look I've made the drivers better off + + + align:start position:0% +look I've made the drivers better off +sure I've created deadweight lost + + align:start position:0% +sure I've created deadweight lost + + + align:start position:0% +sure I've created deadweight lost +beliefs and I made consumers will help + + align:start position:0% +beliefs and I made consumers will help + + + align:start position:0% +beliefs and I made consumers will help +at least I mean these drivers better off + + align:start position:0% +at least I mean these drivers better off + + + align:start position:0% +at least I mean these drivers better off +they leave terrible lives as article in + + align:start position:0% +they leave terrible lives as article in + + + align:start position:0% +they leave terrible lives as article in +the paper all the time about suicides + + align:start position:0% +the paper all the time about suicides + + + align:start position:0% +the paper all the time about suicides +the taxicab drivers it's terrible what + + align:start position:0% +the taxicab drivers it's terrible what + + + align:start position:0% +the taxicab drivers it's terrible what +do they miss yeah they've missed the + + align:start position:0% +do they miss yeah they've missed the + + + align:start position:0% +do they miss yeah they've missed the +fact that the taxicab drivers have to + + align:start position:0% +fact that the taxicab drivers have to + + + align:start position:0% +fact that the taxicab drivers have to +buy the medallions that the limited + + align:start position:0% +buy the medallions that the limited + + + align:start position:0% +buy the medallions that the limited +numbered aliens aren't just given the + + align:start position:0% +numbered aliens aren't just given the + + + align:start position:0% +numbered aliens aren't just given the +taxicab drivers they're bought and the + + align:start position:0% +taxicab drivers they're bought and the + + + align:start position:0% +taxicab drivers they're bought and the +taxicab drivers what is a taxicab driver + + align:start position:0% +taxicab drivers what is a taxicab driver + + + align:start position:0% +taxicab drivers what is a taxicab driver +willing to pay for a medallion they are + + align:start position:0% +willing to pay for a medallion they are + + + align:start position:0% +willing to pay for a medallion they are +willing to pay in the limit the total + + align:start position:0% +willing to pay in the limit the total + + + align:start position:0% +willing to pay in the limit the total +surplus they get from driving the cab - + + align:start position:0% +surplus they get from driving the cab - + + + align:start position:0% +surplus they get from driving the cab - +a dollar or - some amount you know that + + align:start position:0% +a dollar or - some amount you know that + + + align:start position:0% +a dollar or - some amount you know that +they need to eat so if suddenly in a + + align:start position:0% +they need to eat so if suddenly in a + + + align:start position:0% +they need to eat so if suddenly in a +world with no restrictions with no tax + + align:start position:0% +world with no restrictions with no tax + + + align:start position:0% +world with no restrictions with no tax +cab medallions if you said we're gonna + + align:start position:0% +cab medallions if you said we're gonna + + + align:start position:0% +cab medallions if you said we're gonna +be a piece of paper should you drive a + + align:start position:0% +be a piece of paper should you drive a + + + align:start position:0% +be a piece of paper should you drive a +taxi but anyone could have it for free + + align:start position:0% +taxi but anyone could have it for free + + + align:start position:0% +taxi but anyone could have it for free +whoa would it be worth zero but in the + + align:start position:0% +whoa would it be worth zero but in the + + + align:start position:0% +whoa would it be worth zero but in the +world will you say you can if you have + + align:start position:0% +world will you say you can if you have + + + align:start position:0% +world will you say you can if you have +the speed paper you can drive and + + align:start position:0% +the speed paper you can drive and + + + align:start position:0% +the speed paper you can drive and +drivers earn profits pie what will the + + align:start position:0% +drivers earn profits pie what will the + + + align:start position:0% +drivers earn profits pie what will the +taxed have medallions sell for pie - + + align:start position:0% +taxed have medallions sell for pie - + + + align:start position:0% +taxed have medallions sell for pie - +some small amount so actually who wins + + align:start position:0% +some small amount so actually who wins + + + align:start position:0% +some small amount so actually who wins +the taxicab medallion owners and who are + + align:start position:0% +the taxicab medallion owners and who are + + + align:start position:0% +the taxicab medallion owners and who are +they they are random folks who happen to + + align:start position:0% +they they are random folks who happen to + + + align:start position:0% +they they are random folks who happen to +get these things in 1920 when they were + + align:start position:0% +get these things in 1920 when they were + + + align:start position:0% +get these things in 1920 when they were +issued and there + + align:start position:0% +issued and there + + + align:start position:0% +issued and there +descendants and people who bought them + + align:start position:0% +descendants and people who bought them + + + align:start position:0% +descendants and people who bought them +okay so this leads to my great story the + + align:start position:0% +okay so this leads to my great story the + + + align:start position:0% +okay so this leads to my great story the +taxicab medallion king of Long Island + + align:start position:0% +taxicab medallion king of Long Island + + + align:start position:0% +taxicab medallion king of Long Island +was the guy who happened to have a bun + + align:start position:0% +was the guy who happened to have a bun + + + align:start position:0% +was the guy who happened to have a bun +Chee's tax cabinets and as they went + + align:start position:0% +Chee's tax cabinets and as they went + + + align:start position:0% +Chee's tax cabinets and as they went +through the roof they are worth a lot in + + align:start position:0% +through the roof they are worth a lot in + + + align:start position:0% +through the roof they are worth a lot in +New York a tax New York um had 12,000 + + align:start position:0% +New York a tax New York um had 12,000 + + + align:start position:0% +New York a tax New York um had 12,000 +permits and that number did not change + + align:start position:0% +permits and that number did not change + + + align:start position:0% +permits and that number did not change +since they originally sold for $10 each + + align:start position:0% +since they originally sold for $10 each + + + align:start position:0% +since they originally sold for $10 each +in 1937 937 you could have bought her + + align:start position:0% +in 1937 937 you could have bought her + + + align:start position:0% +in 1937 937 you could have bought her +for $10 they issued 12 12,000 + + align:start position:0% +for $10 they issued 12 12,000 + + + align:start position:0% +for $10 they issued 12 12,000 +they've never increased it right now a + + align:start position:0% +they've never increased it right now a + + + align:start position:0% +they've never increased it right now a +tax Hammond I New York is worth $400,000 + + align:start position:0% +tax Hammond I New York is worth $400,000 + + + align:start position:0% +tax Hammond I New York is worth $400,000 +okay well the tax cap king of New York + + align:start position:0% +okay well the tax cap king of New York + + + align:start position:0% +okay well the tax cap king of New York +is a guy lives Long Island who made so + + align:start position:0% +is a guy lives Long Island who made so + + + align:start position:0% +is a guy lives Long Island who made so +much money that he actually uh he + + align:start position:0% +much money that he actually uh he + + + align:start position:0% +much money that he actually uh he +actually first kids Bar Mitzvah + + align:start position:0% +actually first kids Bar Mitzvah + + + align:start position:0% +actually first kids Bar Mitzvah +not only had rented at a hotel ho + + align:start position:0% +not only had rented at a hotel ho + + + align:start position:0% +not only had rented at a hotel ho +basketball theme Bar Mitzvah but hired + + align:start position:0% +basketball theme Bar Mitzvah but hired + + + align:start position:0% +basketball theme Bar Mitzvah but hired +Nicki Minaj okay + + align:start position:0% +Nicki Minaj okay + + + align:start position:0% +Nicki Minaj okay +this was paid for by area B okay this + + align:start position:0% +this was paid for by area B okay this + + + align:start position:0% +this was paid for by area B okay this +was paid for so in fact it's not the + + align:start position:0% +was paid for so in fact it's not the + + + align:start position:0% +was paid for so in fact it's not the +taxi cab drivers that make at under this + + align:start position:0% +taxi cab drivers that make at under this + + + align:start position:0% +taxi cab drivers that make at under this +policy it's a taxi cab medallion king of + + align:start position:0% +policy it's a taxi cab medallion king of + + + align:start position:0% +policy it's a taxi cab medallion king of +La Llorona in who's the big loser not + + align:start position:0% +La Llorona in who's the big loser not + + + align:start position:0% +La Llorona in who's the big loser not +the taxicab drivers the taxi cab + + align:start position:0% +the taxicab drivers the taxi cab + + + align:start position:0% +the taxicab drivers the taxi cab +medallion owners so everyone tells you + + align:start position:0% +medallion owners so everyone tells you + + + align:start position:0% +medallion owners so everyone tells you +burrs a bad thing because these poor + + align:start position:0% +burrs a bad thing because these poor + + + align:start position:0% +burrs a bad thing because these poor +taxi cab drivers are starving taxi cab + + align:start position:0% +taxi cab drivers are starving taxi cab + + + align:start position:0% +taxi cab drivers are starving taxi cab +drivers were always starving it was + + align:start position:0% +drivers were always starving it was + + + align:start position:0% +drivers were always starving it was +always a terrible life the difference + + align:start position:0% +always a terrible life the difference + + + align:start position:0% +always a terrible life the difference +the difference is price and medallions + + align:start position:0% +the difference is price and medallions + + + align:start position:0% +the difference is price and medallions +is down like 50% and I cry no tears for + + align:start position:0% +is down like 50% and I cry no tears for + + + align:start position:0% +is down like 50% and I cry no tears for +the for the Nicki Minaj higher in class + + align:start position:0% +the for the Nicki Minaj higher in class + + + align:start position:0% +the for the Nicki Minaj higher in class +of America okay so basically when you + + align:start position:0% +of America okay so basically when you + + + align:start position:0% +of America okay so basically when you +think about P per se + + align:start position:0% +think about P per se + + + align:start position:0% +think about P per se +Uber's bad it steals jobs tax time + + align:start position:0% +Uber's bad it steals jobs tax time + + + align:start position:0% +Uber's bad it steals jobs tax time +drivers no it doesn't okay it steals + + align:start position:0% +drivers no it doesn't okay it steals + + + align:start position:0% +drivers no it doesn't okay it steals +money from tax cab medallion owners and + + align:start position:0% +money from tax cab medallion owners and + + + align:start position:0% +money from tax cab medallion owners and +that is something we might be okay with + + align:start position:0% +that is something we might be okay with + + + align:start position:0% +that is something we might be okay with +so feel fine taking your uber it's a + + align:start position:0% +so feel fine taking your uber it's a + + + align:start position:0% +so feel fine taking your uber it's a +great it's a great thing so let me stop + + align:start position:0% +great it's a great thing so let me stop + + + align:start position:0% +great it's a great thing so let me stop +there + + align:start position:0% +there + + + align:start position:0% +there +um I'm going to come back come back next + + align:start position:0% +um I'm going to come back come back next + + + align:start position:0% +um I'm going to come back come back next +lecture and we will start talking about + + align:start position:0% +lecture and we will start talking about + + + align:start position:0% +lecture and we will start talking about +monopoly the market structure not the + + align:start position:0% +monopoly the market structure not the + + + align:start position:0% +monopoly the market structure not the +game \ No newline at end of file diff --git a/Penh4mv5gAg.txt b/Penh4mv5gAg.txt new file mode 100644 index 0000000000000000000000000000000000000000..41b7adddafb7c491a57b6e4856c7d5f7a2216d45 --- /dev/null +++ b/Penh4mv5gAg.txt @@ -0,0 +1,2995 @@ +align:start position:0% + +graph coloring is the abstract version + + align:start position:0% +graph coloring is the abstract version + + + align:start position:0% +graph coloring is the abstract version +of a problem that arises from a bunch of + + align:start position:0% +of a problem that arises from a bunch of + + + align:start position:0% +of a problem that arises from a bunch of +conflict scheduling situations so let's + + align:start position:0% +conflict scheduling situations so let's + + + align:start position:0% +conflict scheduling situations so let's +look at an example first and then define + + align:start position:0% +look at an example first and then define + + + align:start position:0% +look at an example first and then define +the problem so let's think about a bunch + + align:start position:0% +the problem so let's think about a bunch + + + align:start position:0% +the problem so let's think about a bunch +of aircraft that have to be scheduled on + + align:start position:0% +of aircraft that have to be scheduled on + + + align:start position:0% +of aircraft that have to be scheduled on +the ground a Czech ports or gates now if + + align:start position:0% +the ground a Czech ports or gates now if + + + align:start position:0% +the ground a Czech ports or gates now if +two flights are on the ground at the + + align:start position:0% +two flights are on the ground at the + + + align:start position:0% +two flights are on the ground at the +same time they need to be assigned to + + align:start position:0% +same time they need to be assigned to + + + align:start position:0% +same time they need to be assigned to +different gates since again serves one + + align:start position:0% +different gates since again serves one + + + align:start position:0% +different gates since again serves one +airplane and what we'd like to do is try + + align:start position:0% +airplane and what we'd like to do is try + + + align:start position:0% +airplane and what we'd like to do is try +to figure out how many different gates + + align:start position:0% +to figure out how many different gates + + + align:start position:0% +to figure out how many different gates +do we need to be able to service all the + + align:start position:0% +do we need to be able to service all the + + + align:start position:0% +do we need to be able to service all the +planes that might be on the ground how + + align:start position:0% +planes that might be on the ground how + + + align:start position:0% +planes that might be on the ground how +many gates are needed so let's look at a + + align:start position:0% +many gates are needed so let's look at a + + + align:start position:0% +many gates are needed so let's look at a +sample schedule there are six flights + + align:start position:0% +sample schedule there are six flights + + + align:start position:0% +sample schedule there are six flights +here numbering 120 to 145 through 99 and + + align:start position:0% +here numbering 120 to 145 through 99 and + + + align:start position:0% +here numbering 120 to 145 through 99 and +these the horizontal bar is say times + + align:start position:0% +these the horizontal bar is say times + + + align:start position:0% +these the horizontal bar is say times +during the day and this blue block + + align:start position:0% +during the day and this blue block + + + align:start position:0% +during the day and this blue block +indicates that flight 122 is on the + + align:start position:0% +indicates that flight 122 is on the + + + align:start position:0% +indicates that flight 122 is on the +ground from let's say 3 a.m. to 7 a.m. + + align:start position:0% +ground from let's say 3 a.m. to 7 a.m. + + + align:start position:0% +ground from let's say 3 a.m. to 7 a.m. +and fight 145 is on the ground and a + + align:start position:0% +and fight 145 is on the ground and a + + + align:start position:0% +and fight 145 is on the ground and a +completely different disjoint time + + align:start position:0% +completely different disjoint time + + + align:start position:0% +completely different disjoint time +interval so 67 to 57 is on the ground + + align:start position:0% +interval so 67 to 57 is on the ground + + + align:start position:0% +interval so 67 to 57 is on the ground +from midnight until about 6 a.m. it does + + align:start position:0% +from midnight until about 6 a.m. it does + + + align:start position:0% +from midnight until about 6 a.m. it does +overlap with 122 and so on so this is + + align:start position:0% +overlap with 122 and so on so this is + + + align:start position:0% +overlap with 122 and so on so this is +the information we have and what we're + + align:start position:0% +the information we have and what we're + + + align:start position:0% +the information we have and what we're +trying to figure out is how many gates + + align:start position:0% +trying to figure out is how many gates + + + align:start position:0% +trying to figure out is how many gates +do we need well it's easy to see here + + align:start position:0% +do we need well it's easy to see here + + + align:start position:0% +do we need well it's easy to see here +that the worst case if you just think of + + align:start position:0% +that the worst case if you just think of + + + align:start position:0% +that the worst case if you just think of +this a vertical Green Line sliding + + align:start position:0% +this a vertical Green Line sliding + + + align:start position:0% +this a vertical Green Line sliding +across the bar and you look at the + + align:start position:0% +across the bar and you look at the + + + align:start position:0% +across the bar and you look at the +maximum number of blue intervals that + + align:start position:0% +maximum number of blue intervals that + + + align:start position:0% +maximum number of blue intervals that +the Green Line ever crosses it's 3 the + + align:start position:0% +the Green Line ever crosses it's 3 the + + + align:start position:0% +the Green Line ever crosses it's 3 the +largest number of planes that are on the + + align:start position:0% +largest number of planes that are on the + + + align:start position:0% +largest number of planes that are on the +gate at any given moment is 3 which + + align:start position:0% +gate at any given moment is 3 which + + + align:start position:0% +gate at any given moment is 3 which +means we can get by with 3 gates so we + + align:start position:0% +means we can get by with 3 gates so we + + + align:start position:0% +means we can get by with 3 gates so we +have to cope with that conflict now so + + align:start position:0% +have to cope with that conflict now so + + + align:start position:0% +have to cope with that conflict now so +abstractly what we're going to do is + + align:start position:0% +abstractly what we're going to do is + + + align:start position:0% +abstractly what we're going to do is +assign each aircraft to be a vertex of a + + align:start position:0% +assign each aircraft to be a vertex of a + + + align:start position:0% +assign each aircraft to be a vertex of a +graph and we're going to put an edge in + + align:start position:0% +graph and we're going to put an edge in + + + align:start position:0% +graph and we're going to put an edge in +to indicate not compatibility but + + align:start position:0% +to indicate not compatibility but + + + align:start position:0% +to indicate not compatibility but +conflict compatibility was what we were + + align:start position:0% +conflict compatibility was what we were + + + align:start position:0% +conflict compatibility was what we were +looking at previously with our examples + + align:start position:0% +looking at previously with our examples + + + align:start position:0% +looking at previously with our examples +of matching now this line means that 306 + + align:start position:0% +of matching now this line means that 306 + + + align:start position:0% +of matching now this line means that 306 +and 145 are on the ground at the same + + align:start position:0% +and 145 are on the ground at the same + + + align:start position:0% +and 145 are on the ground at the same +time they conflict they need the same + + align:start position:0% +time they conflict they need the same + + + align:start position:0% +time they conflict they need the same +gate and we have to serve them with + + align:start position:0% +gate and we have to serve them with + + + align:start position:0% +gate and we have to serve them with +different gates and likewise 99 and 145 + + align:start position:0% +different gates and likewise 99 and 145 + + + align:start position:0% +different gates and likewise 99 and 145 +are on the ground + + align:start position:0% +are on the ground + + + align:start position:0% +are on the ground +$6.99 this was that that the three + + align:start position:0% +$6.99 this was that that the three + + + align:start position:0% +$6.99 this was that that the three +flights that were on the ground at the + + align:start position:0% +flights that were on the ground at the + + + align:start position:0% +flights that were on the ground at the +same time and then if I fill in the + + align:start position:0% +same time and then if I fill in the + + + align:start position:0% +same time and then if I fill in the +computer graph with all the other + + align:start position:0% +computer graph with all the other + + + align:start position:0% +computer graph with all the other +vertices and draw an edge when two + + align:start position:0% +vertices and draw an edge when two + + + align:start position:0% +vertices and draw an edge when two +flights are on the ground at the same + + align:start position:0% +flights are on the ground at the same + + + align:start position:0% +flights are on the ground at the same +time I wind up with this little graph + + align:start position:0% +time I wind up with this little graph + + + align:start position:0% +time I wind up with this little graph +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now we can talk abstractly about the + + align:start position:0% +now we can talk abstractly about the + + + align:start position:0% +now we can talk abstractly about the +coloring problem which is let's assign + + align:start position:0% +coloring problem which is let's assign + + + align:start position:0% +coloring problem which is let's assign +colors to the vertices in such a way + + align:start position:0% +colors to the vertices in such a way + + + align:start position:0% +colors to the vertices in such a way +that no two adjacent vertices have the + + align:start position:0% +that no two adjacent vertices have the + + + align:start position:0% +that no two adjacent vertices have the +same color okay adjacent vertices should + + align:start position:0% +same color okay adjacent vertices should + + + align:start position:0% +same color okay adjacent vertices should +have different colors and it should be + + align:start position:0% +have different colors and it should be + + + align:start position:0% +have different colors and it should be +clear from the description of how we + + align:start position:0% +clear from the description of how we + + + align:start position:0% +clear from the description of how we +derive this graph from the airline + + align:start position:0% +derive this graph from the airline + + + align:start position:0% +derive this graph from the airline +aircraft schedules that the minimum + + align:start position:0% +aircraft schedules that the minimum + + + align:start position:0% +aircraft schedules that the minimum +number of distinct colors needed to + + align:start position:0% +number of distinct colors needed to + + + align:start position:0% +number of distinct colors needed to +color the graph corresponds to the + + align:start position:0% +color the graph corresponds to the + + + align:start position:0% +color the graph corresponds to the +minimum number of gates needed to serve + + align:start position:0% +minimum number of gates needed to serve + + + align:start position:0% +minimum number of gates needed to serve +the aircraft so let's try coloring this + + align:start position:0% +the aircraft so let's try coloring this + + + align:start position:0% +the aircraft so let's try coloring this +graph I'll start with coloring for 257 + + align:start position:0% +graph I'll start with coloring for 257 + + + align:start position:0% +graph I'll start with coloring for 257 +red and 122 yellow and 99 green there's + + align:start position:0% +red and 122 yellow and 99 green there's + + + align:start position:0% +red and 122 yellow and 99 green there's +no loss of generality here because these + + align:start position:0% +no loss of generality here because these + + + align:start position:0% +no loss of generality here because these +are the three that are on the ground at + + align:start position:0% +are the three that are on the ground at + + + align:start position:0% +are the three that are on the ground at +the same time reflected by the fact that + + align:start position:0% +the same time reflected by the fact that + + + align:start position:0% +the same time reflected by the fact that +they're in a triangle and I'm gonna have + + align:start position:0% +they're in a triangle and I'm gonna have + + + align:start position:0% +they're in a triangle and I'm gonna have +to use three different colors since each + + align:start position:0% +to use three different colors since each + + + align:start position:0% +to use three different colors since each +one is adjacent to the other two okay + + align:start position:0% +one is adjacent to the other two okay + + + align:start position:0% +one is adjacent to the other two okay +what next well let's color 145 yellow I + + align:start position:0% +what next well let's color 145 yellow I + + + align:start position:0% +what next well let's color 145 yellow I +might as well reuse it since it's not + + align:start position:0% +might as well reuse it since it's not + + + align:start position:0% +might as well reuse it since it's not +adjacent to a yellow vertex and then um + + align:start position:0% +adjacent to a yellow vertex and then um + + + align:start position:0% +adjacent to a yellow vertex and then um +here I've got a another triangle so if + + align:start position:0% +here I've got a another triangle so if + + + align:start position:0% +here I've got a another triangle so if +I'm not going to use an extra color the + + align:start position:0% +I'm not going to use an extra color the + + + align:start position:0% +I'm not going to use an extra color the +sensible thing to do would be to color + + align:start position:0% +sensible thing to do would be to color + + + align:start position:0% +sensible thing to do would be to color +that red but opus I didn't do that I use + + align:start position:0% +that red but opus I didn't do that I use + + + align:start position:0% +that red but opus I didn't do that I use +the red here there's another triangle I + + align:start position:0% +the red here there's another triangle I + + + align:start position:0% +the red here there's another triangle I +guess that's that allows me to color and + + align:start position:0% +guess that's that allows me to color and + + + align:start position:0% +guess that's that allows me to color and +then I color this black because here I'm + + align:start position:0% +then I color this black because here I'm + + + align:start position:0% +then I color this black because here I'm +stuck I'm adjacent to both a yellow a + + align:start position:0% +stuck I'm adjacent to both a yellow a + + + align:start position:0% +stuck I'm adjacent to both a yellow a +black and a green vertex so I have to + + align:start position:0% +black and a green vertex so I have to + + + align:start position:0% +black and a green vertex so I have to +come up with a fourth color all right we + + align:start position:0% +come up with a fourth color all right we + + + align:start position:0% +come up with a fourth color all right we +did with four colors it means that we + + align:start position:0% +did with four colors it means that we + + + align:start position:0% +did with four colors it means that we +could could have gotten away with four + + align:start position:0% +could could have gotten away with four + + + align:start position:0% +could could have gotten away with four +gates and the colors tell us which + + align:start position:0% +gates and the colors tell us which + + + align:start position:0% +gates and the colors tell us which +aircraft to assign to which gate so 257 + + align:start position:0% +aircraft to assign to which gate so 257 + + + align:start position:0% +aircraft to assign to which gate so 257 +and 67 can both be assigned to the red + + align:start position:0% +and 67 can both be assigned to the red + + + align:start position:0% +and 67 can both be assigned to the red +gate because they are not on the ground + + align:start position:0% +gate because they are not on the ground + + + align:start position:0% +gate because they are not on the ground +at the same time there's no edge between + + align:start position:0% +at the same time there's no edge between + + + align:start position:0% +at the same time there's no edge between +them 122 and 145 can be assigned a + + align:start position:0% +them 122 and 145 can be assigned a + + + align:start position:0% +them 122 and 145 can be assigned a +yellow gate and so on now this was not + + align:start position:0% +yellow gate and so on now this was not + + + align:start position:0% +yellow gate and so on now this was not +the smartest way to color a better + + align:start position:0% +the smartest way to color a better + + + align:start position:0% +the smartest way to color a better +coloring you're shown here you can check + + align:start position:0% +coloring you're shown here you can check + + + align:start position:0% +coloring you're shown here you can check +that every two adjacent vertices have + + align:start position:0% +that every two adjacent vertices have + + + align:start position:0% +that every two adjacent vertices have +different colors and now I've done it + + align:start position:0% +different colors and now I've done it + + + align:start position:0% +different colors and now I've done it +with only three colors red + + align:start position:0% +with only three colors red + + + align:start position:0% +with only three colors red +yellow and green so now there are three + + align:start position:0% +yellow and green so now there are three + + + align:start position:0% +yellow and green so now there are three +gates and I get a better schedule + + align:start position:0% +gates and I get a better schedule + + + align:start position:0% +gates and I get a better schedule +another example of this kind of conflict + + align:start position:0% +another example of this kind of conflict + + + align:start position:0% +another example of this kind of conflict +problem comes up with scheduling final + + align:start position:0% +problem comes up with scheduling final + + + align:start position:0% +problem comes up with scheduling final +exams two subjects conflict if a student + + align:start position:0% +exams two subjects conflict if a student + + + align:start position:0% +exams two subjects conflict if a student +is taking both because if a student is + + align:start position:0% +is taking both because if a student is + + + align:start position:0% +is taking both because if a student is +taking both I can't have the final exams + + align:start position:0% +taking both I can't have the final exams + + + align:start position:0% +taking both I can't have the final exams +at the same time and so I need to assign + + align:start position:0% +at the same time and so I need to assign + + + align:start position:0% +at the same time and so I need to assign +different timeslots during exam period + + align:start position:0% +different timeslots during exam period + + + align:start position:0% +different timeslots during exam period +two subjects that overlap that have a + + align:start position:0% +two subjects that overlap that have a + + + align:start position:0% +two subjects that overlap that have a +student in common and then the question + + align:start position:0% +student in common and then the question + + + align:start position:0% +student in common and then the question +is given this data about which pairs of + + align:start position:0% +is given this data about which pairs of + + + align:start position:0% +is given this data about which pairs of +subjects have a student in common we + + align:start position:0% +subjects have a student in common we + + + align:start position:0% +subjects have a student in common we +want to know how short an exam period + + align:start position:0% +want to know how short an exam period + + + align:start position:0% +want to know how short an exam period +can we get away with again it becomes a + + align:start position:0% +can we get away with again it becomes a + + + align:start position:0% +can we get away with again it becomes a +simple graph model and a coloring + + align:start position:0% +simple graph model and a coloring + + + align:start position:0% +simple graph model and a coloring +problem so here we've drawn a graph with + + align:start position:0% +problem so here we've drawn a graph with + + + align:start position:0% +problem so here we've drawn a graph with +some sample subjects 604 2 and 1802 have + + align:start position:0% +some sample subjects 604 2 and 1802 have + + + align:start position:0% +some sample subjects 604 2 and 1802 have +a student in common that's what that + + align:start position:0% +a student in common that's what that + + + align:start position:0% +a student in common that's what that +edge means they need to be have final + + align:start position:0% +edge means they need to be have final + + + align:start position:0% +edge means they need to be have final +exam scheduled at different times + + align:start position:0% +exam scheduled at different times + + + align:start position:0% +exam scheduled at different times +likewise 802 and 604 to have a student + + align:start position:0% +likewise 802 and 604 to have a student + + + align:start position:0% +likewise 802 and 604 to have a student +in common so they need to be scheduled + + align:start position:0% +in common so they need to be scheduled + + + align:start position:0% +in common so they need to be scheduled +at different times on the other hand 604 + + align:start position:0% +at different times on the other hand 604 + + + align:start position:0% +at different times on the other hand 604 +2 and 1802 sorry what are some two that + + align:start position:0% +2 and 1802 sorry what are some two that + + + align:start position:0% +2 and 1802 sorry what are some two that +are not adjacent + + align:start position:0% +are not adjacent + + + align:start position:0% +are not adjacent +309 1 and 1802 have no edge between them + + align:start position:0% +309 1 and 1802 have no edge between them + + + align:start position:0% +309 1 and 1802 have no edge between them +which means that they can be scheduled + + align:start position:0% +which means that they can be scheduled + + + align:start position:0% +which means that they can be scheduled +at the same time there's no student + + align:start position:0% +at the same time there's no student + + + align:start position:0% +at the same time there's no student +who's taking both 309 1 and 1802 at + + align:start position:0% +who's taking both 309 1 and 1802 at + + + align:start position:0% +who's taking both 309 1 and 1802 at +least according to the data in this + + align:start position:0% +least according to the data in this + + + align:start position:0% +least according to the data in this +graph so let's try covering it and again + + align:start position:0% +graph so let's try covering it and again + + + align:start position:0% +graph so let's try covering it and again +it is a triangle I'm gonna have to use + + align:start position:0% +it is a triangle I'm gonna have to use + + + align:start position:0% +it is a triangle I'm gonna have to use +three different colors for a triangle + + align:start position:0% +three different colors for a triangle + + + align:start position:0% +three different colors for a triangle +and here's another triangle and to be + + align:start position:0% +and here's another triangle and to be + + + align:start position:0% +and here's another triangle and to be +economical let's just reuse green now + + align:start position:0% +economical let's just reuse green now + + + align:start position:0% +economical let's just reuse green now +here I've got another vertex that's + + align:start position:0% +here I've got another vertex that's + + + align:start position:0% +here I've got another vertex that's +adjacent to three different color + + align:start position:0% +adjacent to three different color + + + align:start position:0% +adjacent to three different color +vertices and so it's gonna have to be + + align:start position:0% +vertices and so it's gonna have to be + + + align:start position:0% +vertices and so it's gonna have to be +colored with a fourth color this time it + + align:start position:0% +colored with a fourth color this time it + + + align:start position:0% +colored with a fourth color this time it +turns out that the four colors are best + + align:start position:0% +turns out that the four colors are best + + + align:start position:0% +turns out that the four colors are best +possible you can check that and it + + align:start position:0% +possible you can check that and it + + + align:start position:0% +possible you can check that and it +corresponds to a schedule in which the + + align:start position:0% +corresponds to a schedule in which the + + + align:start position:0% +corresponds to a schedule in which the +604 2 is scheduled on Monday morning at + + align:start position:0% +604 2 is scheduled on Monday morning at + + + align:start position:0% +604 2 is scheduled on Monday morning at +nine and six double-o one is scheduled + + align:start position:0% +nine and six double-o one is scheduled + + + align:start position:0% +nine and six double-o one is scheduled +on Monday at 1:00 + + align:start position:0% +on Monday at 1:00 + + + align:start position:0% +on Monday at 1:00 +but 802 and 309 one can both be + + align:start position:0% +but 802 and 309 one can both be + + + align:start position:0% +but 802 and 309 one can both be +scheduled for Tuesday 9:00 a.m. and + + align:start position:0% +scheduled for Tuesday 9:00 a.m. and + + + align:start position:0% +scheduled for Tuesday 9:00 a.m. and +finally 1802 is scheduled on Tuesday at + + align:start position:0% +finally 1802 is scheduled on Tuesday at + + + align:start position:0% +finally 1802 is scheduled on Tuesday at +1:00 p.m. + + align:start position:0% +1:00 p.m. + + + align:start position:0% +1:00 p.m. +okay so this kind of a conflict modeling + + align:start position:0% +okay so this kind of a conflict modeling + + + align:start position:0% +okay so this kind of a conflict modeling +situation comes up all the time + + align:start position:0% +situation comes up all the time + + + align:start position:0% +situation comes up all the time +another place where you get these kind + + align:start position:0% +another place where you get these kind + + + align:start position:0% +another place where you get these kind +of compatibility graphs or + + align:start position:0% +of compatibility graphs or + + + align:start position:0% +of compatibility graphs or +incompatibility graphs that you want to + + align:start position:0% +incompatibility graphs that you want to + + + align:start position:0% +incompatibility graphs that you want to +color would be if you were running a zoo + + align:start position:0% +color would be if you were running a zoo + + + align:start position:0% +color would be if you were running a zoo +and you had to have separate habit + + align:start position:0% +and you had to have separate habit + + + align:start position:0% +and you had to have separate habit +habitats for certain kinds of species of + + align:start position:0% +habitats for certain kinds of species of + + + align:start position:0% +habitats for certain kinds of species of +animals that you don't want to mix + + align:start position:0% +animals that you don't want to mix + + + align:start position:0% +animals that you don't want to mix +together big fish eat little fish it's a + + align:start position:0% +together big fish eat little fish it's a + + + align:start position:0% +together big fish eat little fish it's a +truism in the aquarium world and so you + + align:start position:0% +truism in the aquarium world and so you + + + align:start position:0% +truism in the aquarium world and so you +need to keep big fish separate from + + align:start position:0% +need to keep big fish separate from + + + align:start position:0% +need to keep big fish separate from +little fish and you don't want the + + align:start position:0% +little fish and you don't want the + + + align:start position:0% +little fish and you don't want the +Tigers living together with the + + align:start position:0% +Tigers living together with the + + + align:start position:0% +Tigers living together with the +chimpanzees so we could again model this + + align:start position:0% +chimpanzees so we could again model this + + + align:start position:0% +chimpanzees so we could again model this +problem as how many cages do we need we + + align:start position:0% +problem as how many cages do we need we + + + align:start position:0% +problem as how many cages do we need we +create a vertex for each species and put + + align:start position:0% +create a vertex for each species and put + + + align:start position:0% +create a vertex for each species and put +an arrow between an edge between two + + align:start position:0% +an arrow between an edge between two + + + align:start position:0% +an arrow between an edge between two +species that mustn't share a habitat or + + align:start position:0% +species that mustn't share a habitat or + + + align:start position:0% +species that mustn't share a habitat or +spheric or share a cage another one + + align:start position:0% +spheric or share a cage another one + + + align:start position:0% +spheric or share a cage another one +would be assigning different frequencies + + align:start position:0% +would be assigning different frequencies + + + align:start position:0% +would be assigning different frequencies +to radio stations and again if two radio + + align:start position:0% +to radio stations and again if two radio + + + align:start position:0% +to radio stations and again if two radio +stations are close to each other they + + align:start position:0% +stations are close to each other they + + + align:start position:0% +stations are close to each other they +they will interfere and so they have to + + align:start position:0% +they will interfere and so they have to + + + align:start position:0% +they will interfere and so they have to +be assigned to different colors or + + align:start position:0% +be assigned to different colors or + + + align:start position:0% +be assigned to different colors or +different frequencies so now we would be + + align:start position:0% +different frequencies so now we would be + + + align:start position:0% +different frequencies so now we would be +using radio stations as vertices and + + align:start position:0% +using radio stations as vertices and + + + align:start position:0% +using radio stations as vertices and +radio stations that were near enough to + + align:start position:0% +radio stations that were near enough to + + + align:start position:0% +radio stations that were near enough to +interfere with each other would get + + align:start position:0% +interfere with each other would get + + + align:start position:0% +interfere with each other would get +connected by an edge indicating that + + align:start position:0% +connected by an edge indicating that + + + align:start position:0% +connected by an edge indicating that +they needed to be assigned different + + align:start position:0% +they needed to be assigned different + + + align:start position:0% +they needed to be assigned different +color frequencies and one of the classic + + align:start position:0% +color frequencies and one of the classic + + + align:start position:0% +color frequencies and one of the classic +ones is literally to color a map if you + + align:start position:0% +ones is literally to color a map if you + + + align:start position:0% +ones is literally to color a map if you +were trying to take say a map of the US + + align:start position:0% +were trying to take say a map of the US + + + align:start position:0% +were trying to take say a map of the US +and assign colors to it in such a way + + align:start position:0% +and assign colors to it in such a way + + + align:start position:0% +and assign colors to it in such a way +that you never had two states that + + align:start position:0% +that you never had two states that + + + align:start position:0% +that you never had two states that +shared a border with the same color and + + align:start position:0% +shared a border with the same color and + + + align:start position:0% +shared a border with the same color and +this is an illustration of doing it with + + align:start position:0% +this is an illustration of doing it with + + + align:start position:0% +this is an illustration of doing it with +four colors the question is if I give + + align:start position:0% +four colors the question is if I give + + + align:start position:0% +four colors the question is if I give +you some kind of a planar map like this + + align:start position:0% +you some kind of a planar map like this + + + align:start position:0% +you some kind of a planar map like this +what's the minimum number of colors that + + align:start position:0% +what's the minimum number of colors that + + + align:start position:0% +what's the minimum number of colors that +will work now you're allowed to have two + + align:start position:0% +will work now you're allowed to have two + + + align:start position:0% +will work now you're allowed to have two +vertices with the two countries rather + + align:start position:0% +vertices with the two countries rather + + + align:start position:0% +vertices with the two countries rather +share the color if they only share a + + align:start position:0% +share the color if they only share a + + + align:start position:0% +share the color if they only share a +meet at one point but if they have a + + align:start position:0% +meet at one point but if they have a + + + align:start position:0% +meet at one point but if they have a +positive length boundary they have to be + + align:start position:0% +positive length boundary they have to be + + + align:start position:0% +positive length boundary they have to be +different colors okay the way that this + + align:start position:0% +different colors okay the way that this + + + align:start position:0% +different colors okay the way that this +turns into a vertex coloring problem is + + align:start position:0% +turns into a vertex coloring problem is + + + align:start position:0% +turns into a vertex coloring problem is +if you take a planar graph like this + + align:start position:0% +if you take a planar graph like this + + + align:start position:0% +if you take a planar graph like this +here's just an arbitrary one what I can + + align:start position:0% +here's just an arbitrary one what I can + + + align:start position:0% +here's just an arbitrary one what I can +do is I'm interested in coloring the + + align:start position:0% +do is I'm interested in coloring the + + + align:start position:0% +do is I'm interested in coloring the +regions the + + align:start position:0% +regions the + + + align:start position:0% +regions the +tres with different colors but I'll just + + align:start position:0% +tres with different colors but I'll just + + + align:start position:0% +tres with different colors but I'll just +replace each region by a vertex so I'm + + align:start position:0% +replace each region by a vertex so I'm + + + align:start position:0% +replace each region by a vertex so I'm +going to stick a vertex in the middle of + + align:start position:0% +going to stick a vertex in the middle of + + + align:start position:0% +going to stick a vertex in the middle of +each of the regions notice there's an + + align:start position:0% +each of the regions notice there's an + + + align:start position:0% +each of the regions notice there's an +outer region here - that gets a vertex + + align:start position:0% +outer region here - that gets a vertex + + + align:start position:0% +outer region here - that gets a vertex +so one two three four five six regions + + align:start position:0% +so one two three four five six regions + + + align:start position:0% +so one two three four five six regions +four six vertices and then I'll simply + + align:start position:0% +four six vertices and then I'll simply + + + align:start position:0% +four six vertices and then I'll simply +connect two vertices when there is a + + align:start position:0% +connect two vertices when there is a + + + align:start position:0% +connect two vertices when there is a +positive length edge that their regions + + align:start position:0% +positive length edge that their regions + + + align:start position:0% +positive length edge that their regions +share so there's that vertex that edge + + align:start position:0% +share so there's that vertex that edge + + + align:start position:0% +share so there's that vertex that edge +corresponds to the fact that there's + + align:start position:0% +corresponds to the fact that there's + + + align:start position:0% +corresponds to the fact that there's +this boundary that's shared between this + + align:start position:0% +this boundary that's shared between this + + + align:start position:0% +this boundary that's shared between this +region in this region if you look at + + align:start position:0% +region in this region if you look at + + + align:start position:0% +region in this region if you look at +this same triangular shaped region it + + align:start position:0% +this same triangular shaped region it + + + align:start position:0% +this same triangular shaped region it +has a boundary with the outside region + + align:start position:0% +has a boundary with the outside region + + + align:start position:0% +has a boundary with the outside region +so there's going to be an edge from here + + align:start position:0% +so there's going to be an edge from here + + + align:start position:0% +so there's going to be an edge from here +to the vertex that represents the + + align:start position:0% +to the vertex that represents the + + + align:start position:0% +to the vertex that represents the +outside and there's the rest of the + + align:start position:0% +outside and there's the rest of the + + + align:start position:0% +outside and there's the rest of the +edges and edge appears when between two + + align:start position:0% +edges and edge appears when between two + + + align:start position:0% +edges and edge appears when between two +regions that share a boundary and now + + align:start position:0% +regions that share a boundary and now + + + align:start position:0% +regions that share a boundary and now +the question is coloring the countries + + align:start position:0% +the question is coloring the countries + + + align:start position:0% +the question is coloring the countries +corresponds to coloring the vertices and + + align:start position:0% +corresponds to coloring the vertices and + + + align:start position:0% +corresponds to coloring the vertices and +we'd like to color the graph with as few + + align:start position:0% +we'd like to color the graph with as few + + + align:start position:0% +we'd like to color the graph with as few +colors as possible well a famous result + + align:start position:0% +colors as possible well a famous result + + + align:start position:0% +colors as possible well a famous result +that was proved in the seventies is that + + align:start position:0% +that was proved in the seventies is that + + + align:start position:0% +that was proved in the seventies is that +every planar graph is in fact four + + align:start position:0% +every planar graph is in fact four + + + align:start position:0% +every planar graph is in fact four +colorable now this was first proved to + + align:start position:0% +colorable now this was first proved to + + + align:start position:0% +colorable now this was first proved to +claim to be proved in the 1850s but in + + align:start position:0% +claim to be proved in the 1850s but in + + + align:start position:0% +claim to be proved in the 1850s but in +fact the published proof was wrong its + + align:start position:0% +fact the published proof was wrong its + + + align:start position:0% +fact the published proof was wrong its +sat around in the journal literature for + + align:start position:0% +sat around in the journal literature for + + + align:start position:0% +sat around in the journal literature for +a decade before somebody found a bug or + + align:start position:0% +a decade before somebody found a bug or + + + align:start position:0% +a decade before somebody found a bug or +that is to say that the proof was wrong + + align:start position:0% +that is to say that the proof was wrong + + + align:start position:0% +that is to say that the proof was wrong +not the result there was a big hole in + + align:start position:0% +not the result there was a big hole in + + + align:start position:0% +not the result there was a big hole in +the proof that that had not been + + align:start position:0% +the proof that that had not been + + + align:start position:0% +the proof that that had not been +adequately justified the proof did give + + align:start position:0% +adequately justified the proof did give + + + align:start position:0% +adequately justified the proof did give +a correct argument for five coloring and + + align:start position:0% +a correct argument for five coloring and + + + align:start position:0% +a correct argument for five coloring and +the four color problem was opened for + + align:start position:0% +the four color problem was opened for + + + align:start position:0% +the four color problem was opened for +over a hundred years then in the 1970s + + align:start position:0% + + + + align:start position:0% + +two mathematicians came up with a proof + + align:start position:0% +two mathematicians came up with a proof + + + align:start position:0% +two mathematicians came up with a proof +of the four color theorem that was very + + align:start position:0% +of the four color theorem that was very + + + align:start position:0% +of the four color theorem that was very +controversial because a lot of it of + + align:start position:0% +controversial because a lot of it of + + + align:start position:0% +controversial because a lot of it of +their proof required a computer program + + align:start position:0% +their proof required a computer program + + + align:start position:0% +their proof required a computer program +to crank through several thousand sample + + align:start position:0% +to crank through several thousand sample + + + align:start position:0% +to crank through several thousand sample +graphs that needed to be verified for 4 + + align:start position:0% +graphs that needed to be verified for 4 + + + align:start position:0% +graphs that needed to be verified for 4 +colorability they had an argument that + + align:start position:0% +colorability they had an argument that + + + align:start position:0% +colorability they had an argument that +showed that that there could only be a + + align:start position:0% +showed that that there could only be a + + + align:start position:0% +showed that that there could only be a +few thousand counter examples if there + + align:start position:0% +few thousand counter examples if there + + + align:start position:0% +few thousand counter examples if there +was or rather if there was any graph + + align:start position:0% +was or rather if there was any graph + + + align:start position:0% +was or rather if there was any graph +that couldn't be for colored it would be + + align:start position:0% +that couldn't be for colored it would be + + + align:start position:0% +that couldn't be for colored it would be +one of these several thousand graphs and + + align:start position:0% +one of these several thousand graphs and + + + align:start position:0% +one of these several thousand graphs and +then they went to work on coloring these + + align:start position:0% +then they went to work on coloring these + + + align:start position:0% +then they went to work on coloring these +several thousand graphs which were + + align:start position:0% +several thousand graphs which were + + + align:start position:0% +several thousand graphs which were +generated with the age eight of a + + align:start position:0% +generated with the age eight of a + + + align:start position:0% +generated with the age eight of a +computer and then colored with the aid + + align:start position:0% +computer and then colored with the aid + + + align:start position:0% +computer and then colored with the aid +of a computer and also by hand + + align:start position:0% +of a computer and also by hand + + + align:start position:0% +of a computer and also by hand +this did not make the mathematical + + align:start position:0% +this did not make the mathematical + + + align:start position:0% +this did not make the mathematical +community happy because a proof like + + align:start position:0% +community happy because a proof like + + + align:start position:0% +community happy because a proof like +that is essentially uncheck Abel a much + + align:start position:0% +that is essentially uncheck Abel a much + + + align:start position:0% +that is essentially uncheck Abel a much +improved version was developed in the + + align:start position:0% +improved version was developed in the + + + align:start position:0% +improved version was developed in the +1990s but it still requires in the end a + + align:start position:0% +1990s but it still requires in the end a + + + align:start position:0% +1990s but it still requires in the end a +computer program to generate about 600 + + align:start position:0% +computer program to generate about 600 + + + align:start position:0% +computer program to generate about 600 +maps and verify their caller ability so + + align:start position:0% +maps and verify their caller ability so + + + align:start position:0% +maps and verify their caller ability so +it remains to find a proof of the + + align:start position:0% +it remains to find a proof of the + + + align:start position:0% +it remains to find a proof of the +four-color theorem that you could say is + + align:start position:0% +four-color theorem that you could say is + + + align:start position:0% +four-color theorem that you could say is +humanly comprehensible without the aid + + align:start position:0% +humanly comprehensible without the aid + + + align:start position:0% +humanly comprehensible without the aid +of a computer but there's no longer any + + align:start position:0% +of a computer but there's no longer any + + + align:start position:0% +of a computer but there's no longer any +doubt really about this theorem in the + + align:start position:0% +doubt really about this theorem in the + + + align:start position:0% +doubt really about this theorem in the +mathematical community in general if I + + align:start position:0% +mathematical community in general if I + + + align:start position:0% +mathematical community in general if I +take an arbitrary graph and I ask what's + + align:start position:0% +take an arbitrary graph and I ask what's + + + align:start position:0% +take an arbitrary graph and I ask what's +the minimum number of colors to color it + + align:start position:0% +the minimum number of colors to color it + + + align:start position:0% +the minimum number of colors to color it +that's called the chromatic number of + + align:start position:0% +that's called the chromatic number of + + + align:start position:0% +that's called the chromatic number of +the graph so Chi of G is the minimum + + align:start position:0% +the graph so Chi of G is the minimum + + + align:start position:0% +the graph so Chi of G is the minimum +number of colors to color G and let's + + align:start position:0% +number of colors to color G and let's + + + align:start position:0% +number of colors to color G and let's +look at some guys for different kinds of + + align:start position:0% +look at some guys for different kinds of + + + align:start position:0% +look at some guys for different kinds of +graphs so here we have a simple cycle of + + align:start position:0% +graphs so here we have a simple cycle of + + + align:start position:0% +graphs so here we have a simple cycle of +length four and it's obvious that that + + align:start position:0% +length four and it's obvious that that + + + align:start position:0% +length four and it's obvious that that +can be colored with two colors just + + align:start position:0% +can be colored with two colors just + + + align:start position:0% +can be colored with two colors just +alternate the colors on the other hand + + align:start position:0% +alternate the colors on the other hand + + + align:start position:0% +alternate the colors on the other hand +so what and if that generalizes I by the + + align:start position:0% +so what and if that generalizes I by the + + + align:start position:0% +so what and if that generalizes I by the +way to any even length cycle the the + + align:start position:0% +way to any even length cycle the the + + + align:start position:0% +way to any even length cycle the the +chromatic number of an even length cycle + + align:start position:0% +chromatic number of an even length cycle + + + align:start position:0% +chromatic number of an even length cycle +is simply two you will color the + + align:start position:0% +is simply two you will color the + + + align:start position:0% +is simply two you will color the +vertices alternately on the other hand + + align:start position:0% +vertices alternately on the other hand + + + align:start position:0% +vertices alternately on the other hand +if the cycle is of odd lengths you're + + align:start position:0% +if the cycle is of odd lengths you're + + + align:start position:0% +if the cycle is of odd lengths you're +gonna need a third color there's no way + + align:start position:0% +gonna need a third color there's no way + + + align:start position:0% +gonna need a third color there's no way +around it because even if you try to get + + align:start position:0% +around it because even if you try to get + + + align:start position:0% +around it because even if you try to get +by with two colors then your color + + align:start position:0% +by with two colors then your color + + + align:start position:0% +by with two colors then your color +things alternately and then when you + + align:start position:0% +things alternately and then when you + + + align:start position:0% +things alternately and then when you +wrap around you discover that um you + + align:start position:0% +wrap around you discover that um you + + + align:start position:0% +wrap around you discover that um you +can't alternately color you're going to + + align:start position:0% +can't alternately color you're going to + + + align:start position:0% +can't alternately color you're going to +need a third color in order to avoid a + + align:start position:0% +need a third color in order to avoid a + + + align:start position:0% +need a third color in order to avoid a +clash so in general the chromatic number + + align:start position:0% +clash so in general the chromatic number + + + align:start position:0% +clash so in general the chromatic number +of an odd length cycle is three the + + align:start position:0% +of an odd length cycle is three the + + + align:start position:0% +of an odd length cycle is three the +complete graph on five vertices is shown + + align:start position:0% +complete graph on five vertices is shown + + + align:start position:0% +complete graph on five vertices is shown +here this is a five vertex graph in + + align:start position:0% +here this is a five vertex graph in + + + align:start position:0% +here this is a five vertex graph in +which every vertex is adjacent to the + + align:start position:0% +which every vertex is adjacent to the + + + align:start position:0% +which every vertex is adjacent to the +other four and since every vertex is + + align:start position:0% +other four and since every vertex is + + + align:start position:0% +other four and since every vertex is +adjacent to the other four you're going + + align:start position:0% +adjacent to the other four you're going + + + align:start position:0% +adjacent to the other four you're going +to need five colors you can't do any + + align:start position:0% +to need five colors you can't do any + + + align:start position:0% +to need five colors you can't do any +better they have to all have different + + align:start position:0% +better they have to all have different + + + align:start position:0% +better they have to all have different +colors and so the chromatic number of + + align:start position:0% +colors and so the chromatic number of + + + align:start position:0% +colors and so the chromatic number of +the complete graph on n vertices where + + align:start position:0% +the complete graph on n vertices where + + + align:start position:0% +the complete graph on n vertices where +every vertex is adjacent to the other n + + align:start position:0% +every vertex is adjacent to the other n + + + align:start position:0% +every vertex is adjacent to the other n +minus one is n another simple example + + align:start position:0% +minus one is n another simple example + + + align:start position:0% +minus one is n another simple example +that comes up is if I take the cycle and + + align:start position:0% +that comes up is if I take the cycle and + + + align:start position:0% +that comes up is if I take the cycle and +I put a an axe + + align:start position:0% +I put a an axe + + + align:start position:0% +I put a an axe +and Axel in the middle call it a wheel + + align:start position:0% +and Axel in the middle call it a wheel + + + align:start position:0% +and Axel in the middle call it a wheel +then a wheel with a a ring of light a + + align:start position:0% +then a wheel with a a ring of light a + + + align:start position:0% +then a wheel with a a ring of light a +cycle of length five around the outside + + align:start position:0% +cycle of length five around the outside + + + align:start position:0% +cycle of length five around the outside +a perimeter of length five is called W + + align:start position:0% +a perimeter of length five is called W + + + align:start position:0% +a perimeter of length five is called W +five and we can color it with four + + align:start position:0% +five and we can color it with four + + + align:start position:0% +five and we can color it with four +colors and in general the argument for + + align:start position:0% +colors and in general the argument for + + + align:start position:0% +colors and in general the argument for +that the chromatic number for an odd + + align:start position:0% +that the chromatic number for an odd + + + align:start position:0% +that the chromatic number for an odd +length wheel is four is that I know I'm + + align:start position:0% +length wheel is four is that I know I'm + + + align:start position:0% +length wheel is four is that I know I'm +going to need three colors to color the + + align:start position:0% +going to need three colors to color the + + + align:start position:0% +going to need three colors to color the +rim and since the axle is adjacent to + + align:start position:0% +rim and since the axle is adjacent to + + + align:start position:0% +rim and since the axle is adjacent to +everything on the rim I'm going to need + + align:start position:0% +everything on the rim I'm going to need + + + align:start position:0% +everything on the rim I'm going to need +a fourth color for it on the other hand + + align:start position:0% +a fourth color for it on the other hand + + + align:start position:0% +a fourth color for it on the other hand +again if the if the perimeter is even + + align:start position:0% +again if the if the perimeter is even + + + align:start position:0% +again if the if the perimeter is even +though I can get by with three colors + + align:start position:0% +though I can get by with three colors + + + align:start position:0% +though I can get by with three colors +one more remark about chromatic numbers + + align:start position:0% +one more remark about chromatic numbers + + + align:start position:0% +one more remark about chromatic numbers +is there's an easy argument that shows + + align:start position:0% +is there's an easy argument that shows + + + align:start position:0% +is there's an easy argument that shows +that if you have a graph every one of + + align:start position:0% +that if you have a graph every one of + + + align:start position:0% +that if you have a graph every one of +whose vertices is at most degree K there + + align:start position:0% +whose vertices is at most degree K there + + + align:start position:0% +whose vertices is at most degree K there +are at most K other vertices adjacent to + + align:start position:0% +are at most K other vertices adjacent to + + + align:start position:0% +are at most K other vertices adjacent to +any given vertex then that implies that + + align:start position:0% +any given vertex then that implies that + + + align:start position:0% +any given vertex then that implies that +the graph is K plus one colorable and + + align:start position:0% +the graph is K plus one colorable and + + + align:start position:0% +the graph is K plus one colorable and +the proof is really constructive and + + align:start position:0% +the proof is really constructive and + + + align:start position:0% +the proof is really constructive and +trivial basically you just start + + align:start position:0% +trivial basically you just start + + + align:start position:0% +trivial basically you just start +coloring the vertices any way you like a + + align:start position:0% +coloring the vertices any way you like a + + + align:start position:0% +coloring the vertices any way you like a +subject to the constraint that when you + + align:start position:0% +subject to the constraint that when you + + + align:start position:0% +subject to the constraint that when you +color a vertex it's supposed to not be + + align:start position:0% +color a vertex it's supposed to not be + + + align:start position:0% +color a vertex it's supposed to not be +the same color as any of the vertices + + align:start position:0% +the same color as any of the vertices + + + align:start position:0% +the same color as any of the vertices +around it but that's easy to do because + + align:start position:0% +around it but that's easy to do because + + + align:start position:0% +around it but that's easy to do because +when it's time to color some vertex even + + align:start position:0% +when it's time to color some vertex even + + + align:start position:0% +when it's time to color some vertex even +if all the vertices around it are + + align:start position:0% +if all the vertices around it are + + + align:start position:0% +if all the vertices around it are +coloured there's only K of them and so I + + align:start position:0% +coloured there's only K of them and so I + + + align:start position:0% +coloured there's only K of them and so I +will always be able to find a k plus + + align:start position:0% +will always be able to find a k plus + + + align:start position:0% +will always be able to find a k plus +first color to assign it without and get + + align:start position:0% +first color to assign it without and get + + + align:start position:0% +first color to assign it without and get +a satisfactory coloring so I can get by + + align:start position:0% +a satisfactory coloring so I can get by + + + align:start position:0% +a satisfactory coloring so I can get by +with K plus 1 colors now the general + + align:start position:0% +with K plus 1 colors now the general + + + align:start position:0% +with K plus 1 colors now the general +setup with color ability is that to + + align:start position:0% +setup with color ability is that to + + + align:start position:0% +setup with color ability is that to +check whether a graph is 2 colorable is + + align:start position:0% +check whether a graph is 2 colorable is + + + align:start position:0% +check whether a graph is 2 colorable is +actually very easy and we may talk about + + align:start position:0% +actually very easy and we may talk about + + + align:start position:0% +actually very easy and we may talk about +that in some class problems but 3 + + align:start position:0% +that in some class problems but 3 + + + align:start position:0% +that in some class problems but 3 +colorability dramatically changes we're + + align:start position:0% +colorability dramatically changes we're + + + align:start position:0% +colorability dramatically changes we're +back in the realm of np-complete + + align:start position:0% +back in the realm of np-complete + + + align:start position:0% +back in the realm of np-complete +problems in fact a result of a student + + align:start position:0% +problems in fact a result of a student + + + align:start position:0% +problems in fact a result of a student +of mine almost 40 years ago was that + + align:start position:0% +of mine almost 40 years ago was that + + + align:start position:0% +of mine almost 40 years ago was that +even if a graph is planar where you know + + align:start position:0% +even if a graph is planar where you know + + + align:start position:0% +even if a graph is planar where you know +it can definitely be colored with four + + align:start position:0% +it can definitely be colored with four + + + align:start position:0% +it can definitely be colored with four +colors determining whether or not it can + + align:start position:0% +colors determining whether or not it can + + + align:start position:0% +colors determining whether or not it can +be colored with three colors is as hard + + align:start position:0% +be colored with three colors is as hard + + + align:start position:0% +be colored with three colors is as hard +as satisfiability + + align:start position:0% +as satisfiability + + + align:start position:0% +as satisfiability +and it is in fact an np-complete problem + + align:start position:0% +and it is in fact an np-complete problem + + + align:start position:0% +and it is in fact an np-complete problem +in fact the proof of how you reduce + + align:start position:0% +in fact the proof of how you reduce + + + align:start position:0% +in fact the proof of how you reduce +satisfiability the color ability appears + + align:start position:0% +satisfiability the color ability appears + + + align:start position:0% +satisfiability the color ability appears +in a problem in the text which we may + + align:start position:0% +in a problem in the text which we may + + + align:start position:0% +in a problem in the text which we may +assign as a problem set problem + + align:start position:0% +assign as a problem set problem + + + align:start position:0% +assign as a problem set problem +so in general finding Chi of G is hard + + align:start position:0% +so in general finding Chi of G is hard + + + align:start position:0% +so in general finding Chi of G is hard +even for three colors now it's not any + + align:start position:0% +even for three colors now it's not any + + + align:start position:0% +even for three colors now it's not any +worse again from a theoretical point of + + align:start position:0% +worse again from a theoretical point of + + + align:start position:0% +worse again from a theoretical point of +view for for checking what Khayyam G is + + align:start position:0% +view for for checking what Khayyam G is + + + align:start position:0% +view for for checking what Khayyam G is +even if it's a very large number or the + + align:start position:0% +even if it's a very large number or the + + + align:start position:0% +even if it's a very large number or the +pragmatically three color will be easier + + align:start position:0% +pragmatically three color will be easier + + + align:start position:0% +pragmatically three color will be easier +to check than end color ability and that + + align:start position:0% +to check than end color ability and that + + + align:start position:0% +to check than end color ability and that +is our story about color ability \ No newline at end of file diff --git a/PsUPRyatjxw.txt b/PsUPRyatjxw.txt new file mode 100644 index 0000000000000000000000000000000000000000..643471067a3214ad8295a01bf1ff92e5a013e205 --- /dev/null +++ b/PsUPRyatjxw.txt @@ -0,0 +1,7803 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +hi today I'd like to discuss a specific + + align:start position:0% +hi today I'd like to discuss a specific + + + align:start position:0% +hi today I'd like to discuss a specific +kind of an electronic feedback system + + align:start position:0% +kind of an electronic feedback system + + + align:start position:0% +kind of an electronic feedback system +called a phase locked Loop the general + + align:start position:0% +called a phase locked Loop the general + + + align:start position:0% +called a phase locked Loop the general +topology for a phase locked Loop is + + align:start position:0% +topology for a phase locked Loop is + + + align:start position:0% +topology for a phase locked Loop is +shown on the board the input to this + + align:start position:0% +shown on the board the input to this + + + align:start position:0% +shown on the board the input to this +type of a system is a command frequency + + align:start position:0% +type of a system is a command frequency + + + align:start position:0% +type of a system is a command frequency +and the information that we're + + align:start position:0% +and the information that we're + + + align:start position:0% +and the information that we're +interested in in that input signal is + + align:start position:0% +interested in in that input signal is + + + align:start position:0% +interested in in that input signal is +specifically its + + align:start position:0% +specifically its + + + align:start position:0% +specifically its +frequency in certain kinds of phase lock + + align:start position:0% +frequency in certain kinds of phase lock + + + align:start position:0% +frequency in certain kinds of phase lock +Loops we have a sidal input and others + + align:start position:0% +Loops we have a sidal input and others + + + align:start position:0% +Loops we have a sidal input and others +we may have a digital logic kind of + + align:start position:0% +we may have a digital logic kind of + + + align:start position:0% +we may have a digital logic kind of +signal but Say in any of these the + + align:start position:0% +signal but Say in any of these the + + + align:start position:0% +signal but Say in any of these the +common feature is that the information + + align:start position:0% +common feature is that the information + + + align:start position:0% +common feature is that the information +of interest is the frequency of the + + align:start position:0% +of interest is the frequency of the + + + align:start position:0% +of interest is the frequency of the +signal that input signal or command + + align:start position:0% +signal that input signal or command + + + align:start position:0% +signal that input signal or command +signal is applied to a phase + + align:start position:0% +signal is applied to a phase + + + align:start position:0% +signal is applied to a phase +detector and the output of the phase + + align:start position:0% +detector and the output of the phase + + + align:start position:0% +detector and the output of the phase +detector goes to an element indicated as + + align:start position:0% +detector goes to an element indicated as + + + align:start position:0% +detector goes to an element indicated as +a Loop filter the loop filter is sort of + + align:start position:0% +a Loop filter the loop filter is sort of + + + align:start position:0% +a Loop filter the loop filter is sort of +jargon in phas lock loop technology for + + align:start position:0% +jargon in phas lock loop technology for + + + align:start position:0% +jargon in phas lock loop technology for +what we've been calling compensation all + + align:start position:0% +what we've been calling compensation all + + + align:start position:0% +what we've been calling compensation all +along for some reason it seems + + align:start position:0% +along for some reason it seems + + + align:start position:0% +along for some reason it seems +traditional in this technology to call + + align:start position:0% +traditional in this technology to call + + + align:start position:0% +traditional in this technology to call +the compensating element the one that + + align:start position:0% +the compensating element the one that + + + align:start position:0% +the compensating element the one that +provides Loop stability the loop filter + + align:start position:0% +provides Loop stability the loop filter + + + align:start position:0% +provides Loop stability the loop filter +the output signal from the loop filter + + align:start position:0% +the output signal from the loop filter + + + align:start position:0% +the output signal from the loop filter +is applied to a voltage controlled + + align:start position:0% +is applied to a voltage controlled + + + align:start position:0% +is applied to a voltage controlled +oscillator and of course the frequency + + align:start position:0% +oscillator and of course the frequency + + + align:start position:0% +oscillator and of course the frequency +out of this voltage controlled + + align:start position:0% +out of this voltage controlled + + + align:start position:0% +out of this voltage controlled +oscillator depends on the signal applied + + align:start position:0% +oscillator depends on the signal applied + + + align:start position:0% +oscillator depends on the signal applied +at its input that that frequency is the + + align:start position:0% +at its input that that frequency is the + + + align:start position:0% +at its input that that frequency is the +response of the system and again the + + align:start position:0% +response of the system and again the + + + align:start position:0% +response of the system and again the +thing we're interested in of course is + + align:start position:0% +thing we're interested in of course is + + + align:start position:0% +thing we're interested in of course is +the frequency of the output + + align:start position:0% +the frequency of the output + + + align:start position:0% +the frequency of the output +signal the output signal is then fed + + align:start position:0% +signal the output signal is then fed + + + align:start position:0% +signal the output signal is then fed +back to form the second input to the + + align:start position:0% +back to form the second input to the + + + align:start position:0% +back to form the second input to the +phase detector the signal out of the + + align:start position:0% +phase detector the signal out of the + + + align:start position:0% +phase detector the signal out of the +phase detector in a way that we'll see + + align:start position:0% +phase detector in a way that we'll see + + + align:start position:0% +phase detector in a way that we'll see +in a in a bit is proportional in some + + align:start position:0% +in a in a bit is proportional in some + + + align:start position:0% +in a in a bit is proportional in some +sense to the difference in Phase between + + align:start position:0% +sense to the difference in Phase between + + + align:start position:0% +sense to the difference in Phase between +its two + + align:start position:0% +its two + + + align:start position:0% +its two +inputs there are numerous applications + + align:start position:0% +inputs there are numerous applications + + + align:start position:0% +inputs there are numerous applications +for this sort of of circuit uh for + + align:start position:0% +for this sort of of circuit uh for + + + align:start position:0% +for this sort of of circuit uh for +example one way to use a phase lock loop + + align:start position:0% +example one way to use a phase lock loop + + + align:start position:0% +example one way to use a phase lock loop +is to is as a uh detector for frequency + + align:start position:0% +is to is as a uh detector for frequency + + + align:start position:0% +is to is as a uh detector for frequency +modulated + + align:start position:0% +modulated + + + align:start position:0% +modulated +signals the signal at this point the + + align:start position:0% +signals the signal at this point the + + + align:start position:0% +signals the signal at this point the +phase error between the command + + align:start position:0% +phase error between the command + + + align:start position:0% +phase error between the command +frequency and the response frequency is + + align:start position:0% +frequency and the response frequency is + + + align:start position:0% +frequency and the response frequency is +of course effectively the error signal + + align:start position:0% +of course effectively the error signal + + + align:start position:0% +of course effectively the error signal +in the loop and if we have a loop with + + align:start position:0% +in the loop and if we have a loop with + + + align:start position:0% +in the loop and if we have a loop with +highd sensitivity with large loop + + align:start position:0% +highd sensitivity with large loop + + + align:start position:0% +highd sensitivity with large loop +transmission magnitude the response + + align:start position:0% +transmission magnitude the response + + + align:start position:0% +transmission magnitude the response +frequency should be very nearly + + align:start position:0% +frequency should be very nearly + + + align:start position:0% +frequency should be very nearly +identical to the command frequency in + + align:start position:0% +identical to the command frequency in + + + align:start position:0% +identical to the command frequency in +fact the phase difference between those + + align:start position:0% +fact the phase difference between those + + + align:start position:0% +fact the phase difference between those +two signals should be very very small + + align:start position:0% +two signals should be very very small + + + align:start position:0% +two signals should be very very small +hence the name phase lock blop if in + + align:start position:0% +hence the name phase lock blop if in + + + align:start position:0% +hence the name phase lock blop if in +addition to that we have a voltage + + align:start position:0% +addition to that we have a voltage + + + align:start position:0% +addition to that we have a voltage +controlled oscillator that's linear that + + align:start position:0% +controlled oscillator that's linear that + + + align:start position:0% +controlled oscillator that's linear that +is whose output frequency is directly + + align:start position:0% +is whose output frequency is directly + + + align:start position:0% +is whose output frequency is directly +proportional to its input voltage we're + + align:start position:0% +proportional to its input voltage we're + + + align:start position:0% +proportional to its input voltage we're +able to use the voltage at this point as + + align:start position:0% +able to use the voltage at this point as + + + align:start position:0% +able to use the voltage at this point as +a measure of the frequency of operation + + align:start position:0% +a measure of the frequency of operation + + + align:start position:0% +a measure of the frequency of operation +of the voltage controlled oscillator and + + align:start position:0% +of the voltage controlled oscillator and + + + align:start position:0% +of the voltage controlled oscillator and +when the loop is locked as a measure of + + align:start position:0% +when the loop is locked as a measure of + + + align:start position:0% +when the loop is locked as a measure of +the input frequency or the command + + align:start position:0% +the input frequency or the command + + + align:start position:0% +the input frequency or the command +frequency and so in that way we're able + + align:start position:0% +frequency and so in that way we're able + + + align:start position:0% +frequency and so in that way we're able +to use a phase locked loop as an FM Dem + + align:start position:0% +to use a phase locked loop as an FM Dem + + + align:start position:0% +to use a phase locked loop as an FM Dem +modulator the signal at this point will + + align:start position:0% +modulator the signal at this point will + + + align:start position:0% +modulator the signal at this point will +be proportional to the frequency applied + + align:start position:0% +be proportional to the frequency applied + + + align:start position:0% +be proportional to the frequency applied +to the + + align:start position:0% +to the + + + align:start position:0% +to the +input in other applications we use phase + + align:start position:0% +input in other applications we use phase + + + align:start position:0% +input in other applications we use phase +locked Loops to recover carriers in + + align:start position:0% +locked Loops to recover carriers in + + + align:start position:0% +locked Loops to recover carriers in +again communication systems where we're + + align:start position:0% +again communication systems where we're + + + align:start position:0% +again communication systems where we're +interested for example in generating a + + align:start position:0% +interested for example in generating a + + + align:start position:0% +interested for example in generating a +carrier or a center frequency locally + + align:start position:0% +carrier or a center frequency locally + + + align:start position:0% +carrier or a center frequency locally +for use in some sort of Dem modulation + + align:start position:0% +for use in some sort of Dem modulation + + + align:start position:0% +for use in some sort of Dem modulation +scheme typically in those sorts of + + align:start position:0% +scheme typically in those sorts of + + + align:start position:0% +scheme typically in those sorts of +applications because the input signal + + align:start position:0% +applications because the input signal + + + align:start position:0% +applications because the input signal +may be quite noisy we get filtering out + + align:start position:0% +may be quite noisy we get filtering out + + + align:start position:0% +may be quite noisy we get filtering out +of the phase locked Loop by really + + align:start position:0% +of the phase locked Loop by really + + + align:start position:0% +of the phase locked Loop by really +making it a narrow band filter by + + align:start position:0% +making it a narrow band filter by + + + align:start position:0% +making it a narrow band filter by +effectively greatly reducing the + + align:start position:0% +effectively greatly reducing the + + + align:start position:0% +effectively greatly reducing the +crossover frequency of the feedback + + align:start position:0% +crossover frequency of the feedback + + + align:start position:0% +crossover frequency of the feedback +system that mechanized the phase locked + + align:start position:0% +system that mechanized the phase locked + + + align:start position:0% +system that mechanized the phase locked +Loop that crossover frequency becomes + + align:start position:0% +Loop that crossover frequency becomes + + + align:start position:0% +Loop that crossover frequency becomes +approximately the filter bandwidth and + + align:start position:0% +approximately the filter bandwidth and + + + align:start position:0% +approximately the filter bandwidth and +we're able to then recover a fairly + + align:start position:0% +we're able to then recover a fairly + + + align:start position:0% +we're able to then recover a fairly +noisy carrier signal and somehow use + + align:start position:0% +noisy carrier signal and somehow use + + + align:start position:0% +noisy carrier signal and somehow use +that in a further demodulating process + + align:start position:0% +that in a further demodulating process + + + align:start position:0% +that in a further demodulating process +in a communication + + align:start position:0% +in a communication + + + align:start position:0% +in a communication +system another application of phase lock + + align:start position:0% +system another application of phase lock + + + align:start position:0% +system another application of phase lock +Loops is in frequency + + align:start position:0% +Loops is in frequency + + + align:start position:0% +Loops is in frequency +synthesizers suppose we have the basic + + align:start position:0% +synthesizers suppose we have the basic + + + align:start position:0% +synthesizers suppose we have the basic +phase lock loop as shown but in in + + align:start position:0% +phase lock loop as shown but in in + + + align:start position:0% +phase lock loop as shown but in in +addition we put in a counter in the + + align:start position:0% +addition we put in a counter in the + + + align:start position:0% +addition we put in a counter in the +feedback path uh a divide byn sort of a + + align:start position:0% +feedback path uh a divide byn sort of a + + + align:start position:0% +feedback path uh a divide byn sort of a +circuit + + align:start position:0% + + + + align:start position:0% + +like so in the feedback path and now + + align:start position:0% +like so in the feedback path and now + + + align:start position:0% +like so in the feedback path and now +let's see what the relationships are + + align:start position:0% +let's see what the relationships are + + + align:start position:0% +let's see what the relationships are +well the to the extent that the loop + + align:start position:0% +well the to the extent that the loop + + + align:start position:0% +well the to the extent that the loop +captures we argue that the signal at + + align:start position:0% +captures we argue that the signal at + + + align:start position:0% +captures we argue that the signal at +this point must be equal to the command + + align:start position:0% +this point must be equal to the command + + + align:start position:0% +this point must be equal to the command +frequency and consequently the response + + align:start position:0% +frequency and consequently the response + + + align:start position:0% +frequency and consequently the response +uh of the system will have to be + + align:start position:0% +uh of the system will have to be + + + align:start position:0% +uh of the system will have to be +equal I'm sorry I have have this in + + align:start position:0% +equal I'm sorry I have have this in + + + align:start position:0% +equal I'm sorry I have have this in +correct the command frequency will will + + align:start position:0% +correct the command frequency will will + + + align:start position:0% +correct the command frequency will will +be equal to the response frequency + + align:start position:0% +be equal to the response frequency + + + align:start position:0% +be equal to the response frequency +divided by n consequently the frequency + + align:start position:0% +divided by n consequently the frequency + + + align:start position:0% +divided by n consequently the frequency +of respon supplied by the system the + + align:start position:0% +of respon supplied by the system the + + + align:start position:0% +of respon supplied by the system the +output frequency of the system will + + align:start position:0% +output frequency of the system will + + + align:start position:0% +output frequency of the system will +simply be equal to n times the command + + align:start position:0% +simply be equal to n times the command + + + align:start position:0% +simply be equal to n times the command +frequency when we use this technique for + + align:start position:0% +frequency when we use this technique for + + + align:start position:0% +frequency when we use this technique for +frequency synthesis we make the command + + align:start position:0% +frequency synthesis we make the command + + + align:start position:0% +frequency synthesis we make the command +frequency a very precisely known + + align:start position:0% +frequency a very precisely known + + + align:start position:0% +frequency a very precisely known +frequency this is derived from a very + + align:start position:0% +frequency this is derived from a very + + + align:start position:0% +frequency this is derived from a very +high stability oscillator an atomicon + + align:start position:0% +high stability oscillator an atomicon + + + align:start position:0% +high stability oscillator an atomicon +something like that + + align:start position:0% +something like that + + + align:start position:0% +something like that +we're then able to by changing the + + align:start position:0% +we're then able to by changing the + + + align:start position:0% +we're then able to by changing the +division ratio in a digital divider and + + align:start position:0% +division ratio in a digital divider and + + + align:start position:0% +division ratio in a digital divider and +is of course an in an integral number we + + align:start position:0% +is of course an in an integral number we + + + align:start position:0% +is of course an in an integral number we +can build a divide byn sort of digital + + align:start position:0% +can build a divide byn sort of digital + + + align:start position:0% +can build a divide byn sort of digital +circuit uh we are then able to in + + align:start position:0% +circuit uh we are then able to in + + + align:start position:0% +circuit uh we are then able to in +discrete steps get a response frequency + + align:start position:0% +discrete steps get a response frequency + + + align:start position:0% +discrete steps get a response frequency +that's a direct multiple of the command + + align:start position:0% +that's a direct multiple of the command + + + align:start position:0% +that's a direct multiple of the command +frequency consequently we can generate + + align:start position:0% +frequency consequently we can generate + + + align:start position:0% +frequency consequently we can generate +uh with uh a resolution dependent on + + align:start position:0% +uh with uh a resolution dependent on + + + align:start position:0% +uh with uh a resolution dependent on +actually the frequency of the command + + align:start position:0% +actually the frequency of the command + + + align:start position:0% +actually the frequency of the command +signal with that sort of resolution + + align:start position:0% +signal with that sort of resolution + + + align:start position:0% +signal with that sort of resolution +since we get inte multiples of that + + align:start position:0% +since we get inte multiples of that + + + align:start position:0% +since we get inte multiples of that +frequency at the output we're able to + + align:start position:0% +frequency at the output we're able to + + + align:start position:0% +frequency at the output we're able to +generate multiple frequencies Each of + + align:start position:0% +generate multiple frequencies Each of + + + align:start position:0% +generate multiple frequencies Each of +which has the same stability as the + + align:start position:0% +which has the same stability as the + + + align:start position:0% +which has the same stability as the +command frequency and so this technique + + align:start position:0% +command frequency and so this technique + + + align:start position:0% +command frequency and so this technique +is is used in frequency + + align:start position:0% +is is used in frequency + + + align:start position:0% +is is used in frequency +synthesizers in order to investigate the + + align:start position:0% +synthesizers in order to investigate the + + + align:start position:0% +synthesizers in order to investigate the +feedback aspects of a phase lock loop we + + align:start position:0% +feedback aspects of a phase lock loop we + + + align:start position:0% +feedback aspects of a phase lock loop we +have to look at a a model for that sort + + align:start position:0% +have to look at a a model for that sort + + + align:start position:0% +have to look at a a model for that sort +of a system and in particular we have to + + align:start position:0% +of a system and in particular we have to + + + align:start position:0% +of a system and in particular we have to +consider how we model the phase detector + + align:start position:0% +consider how we model the phase detector + + + align:start position:0% +consider how we model the phase detector +as we'll see there these systems are + + align:start position:0% +as we'll see there these systems are + + + align:start position:0% +as we'll see there these systems are +typically non linear uh in in quite + + align:start position:0% +typically non linear uh in in quite + + + align:start position:0% +typically non linear uh in in quite +important ways and in ways that that + + align:start position:0% +important ways and in ways that that + + + align:start position:0% +important ways and in ways that that +have very profound implications for the + + align:start position:0% +have very profound implications for the + + + align:start position:0% +have very profound implications for the +operation of a system but generally we + + align:start position:0% +operation of a system but generally we + + + align:start position:0% +operation of a system but generally we +can model them for some limited range of + + align:start position:0% +can model them for some limited range of + + + align:start position:0% +can model them for some limited range of +difference between the input frequency + + align:start position:0% +difference between the input frequency + + + align:start position:0% +difference between the input frequency +and the response frequency as a linear + + align:start position:0% +and the response frequency as a linear + + + align:start position:0% +and the response frequency as a linear +system and when we do that we end up + + align:start position:0% +system and when we do that we end up + + + align:start position:0% +system and when we do that we end up +with a linearized block diagram that's + + align:start position:0% +with a linearized block diagram that's + + + align:start position:0% +with a linearized block diagram that's +something like this we have our + + align:start position:0% +something like this we have our + + + align:start position:0% +something like this we have our +commanded frequency at the input again + + align:start position:0% +commanded frequency at the input again + + + align:start position:0% +commanded frequency at the input again +I'm using linear notation or or + + align:start position:0% +I'm using linear notation or or + + + align:start position:0% +I'm using linear notation or or +frequency domain not ation here the + + align:start position:0% +frequency domain not ation here the + + + align:start position:0% +frequency domain not ation here the +capital F sub lower case C as the input + + align:start position:0% +capital F sub lower case C as the input + + + align:start position:0% +capital F sub lower case C as the input +to our system and the system responds uh + + align:start position:0% +to our system and the system responds uh + + + align:start position:0% +to our system and the system responds uh +the L the linearized or the transform of + + align:start position:0% +the L the linearized or the transform of + + + align:start position:0% +the L the linearized or the transform of +the linearized output is capital F sub + + align:start position:0% +the linearized output is capital F sub + + + align:start position:0% +the linearized output is capital F sub +lowercase R and we subtract that those + + align:start position:0% +lowercase R and we subtract that those + + + align:start position:0% +lowercase R and we subtract that those +two quantities the resultant difference + + align:start position:0% +two quantities the resultant difference + + + align:start position:0% +two quantities the resultant difference +is the error in frequency between the + + align:start position:0% +is the error in frequency between the + + + align:start position:0% +is the error in frequency between the +command signal and the signal being + + align:start position:0% +command signal and the signal being + + + align:start position:0% +command signal and the signal being +provided by the phase locked Loop but + + align:start position:0% +provided by the phase locked Loop but + + + align:start position:0% +provided by the phase locked Loop but +this is a frequency + + align:start position:0% +this is a frequency + + + align:start position:0% +this is a frequency +quantity this is a number that tells us + + align:start position:0% +quantity this is a number that tells us + + + align:start position:0% +quantity this is a number that tells us +the number of cycles per second + + align:start position:0% +the number of cycles per second + + + align:start position:0% +the number of cycles per second +difference for example between this + + align:start position:0% +difference for example between this + + + align:start position:0% +difference for example between this +signal and the + + align:start position:0% +signal and the + + + align:start position:0% +signal and the +signal but our phase detector doesn't + + align:start position:0% +signal but our phase detector doesn't + + + align:start position:0% +signal but our phase detector doesn't +measure frequency it measures phase and + + align:start position:0% +measure frequency it measures phase and + + + align:start position:0% +measure frequency it measures phase and +of course phase is simply the integral + + align:start position:0% +of course phase is simply the integral + + + align:start position:0% +of course phase is simply the integral +of frequency if we have two signals that + + align:start position:0% +of frequency if we have two signals that + + + align:start position:0% +of frequency if we have two signals that +differ in frequency by some amount their + + align:start position:0% +differ in frequency by some amount their + + + align:start position:0% +differ in frequency by some amount their +relative phase changes linearly with + + align:start position:0% +relative phase changes linearly with + + + align:start position:0% +relative phase changes linearly with +time providing the two frequencies are + + align:start position:0% +time providing the two frequencies are + + + align:start position:0% +time providing the two frequencies are +different but each constant the pH angle + + align:start position:0% +different but each constant the pH angle + + + align:start position:0% +different but each constant the pH angle +between the two of them is a progressive + + align:start position:0% +between the two of them is a progressive + + + align:start position:0% +between the two of them is a progressive +function of time and in fact linearly + + align:start position:0% +function of time and in fact linearly + + + align:start position:0% +function of time and in fact linearly +proportional to time uh consequently + + align:start position:0% +proportional to time uh consequently + + + align:start position:0% +proportional to time uh consequently +when we're interested in the error in + + align:start position:0% +when we're interested in the error in + + + align:start position:0% +when we're interested in the error in +Phase rather than the error in frequency + + align:start position:0% +Phase rather than the error in frequency + + + align:start position:0% +Phase rather than the error in frequency +and the error in phase is what our phase + + align:start position:0% +and the error in phase is what our phase + + + align:start position:0% +and the error in phase is what our phase +detector really gives us there's a + + align:start position:0% +detector really gives us there's a + + + align:start position:0% +detector really gives us there's a +single integration between frequency and + + align:start position:0% +single integration between frequency and + + + align:start position:0% +single integration between frequency and +phase and we represent that as simply a + + align:start position:0% +phase and we represent that as simply a + + + align:start position:0% +phase and we represent that as simply a +1 /s in our block + + align:start position:0% +1 /s in our block + + + align:start position:0% +1 /s in our block +diagram there's then some gain Factor + + align:start position:0% +diagram there's then some gain Factor + + + align:start position:0% +diagram there's then some gain Factor +some scale factor associated with + + align:start position:0% +some scale factor associated with + + + align:start position:0% +some scale factor associated with +whatever way we we mechanize the phase + + align:start position:0% +whatever way we we mechanize the phase + + + align:start position:0% +whatever way we we mechanize the phase +detector and again we'll see examples of + + align:start position:0% +detector and again we'll see examples of + + + align:start position:0% +detector and again we'll see examples of +that in a moment so we get some gain + + align:start position:0% +that in a moment so we get some gain + + + align:start position:0% +that in a moment so we get some gain +scale factor associated with the phase + + align:start position:0% +scale factor associated with the phase + + + align:start position:0% +scale factor associated with the phase +detector itself we then go through our + + align:start position:0% +detector itself we then go through our + + + align:start position:0% +detector itself we then go through our +Loop filter AF ofs uh there's presumably + + align:start position:0% +Loop filter AF ofs uh there's presumably + + + align:start position:0% +Loop filter AF ofs uh there's presumably +some scale factor associated with the + + align:start position:0% +some scale factor associated with the + + + align:start position:0% +some scale factor associated with the +voltage controlled oscillator in other + + align:start position:0% +voltage controlled oscillator in other + + + align:start position:0% +voltage controlled oscillator in other +words some number of volts at the input + + align:start position:0% +words some number of volts at the input + + + align:start position:0% +words some number of volts at the input +of the of the voltage controlled + + align:start position:0% +of the of the voltage controlled + + + align:start position:0% +of the of the voltage controlled +oscillator gives us a given change in + + align:start position:0% +oscillator gives us a given change in + + + align:start position:0% +oscillator gives us a given change in +its output frequency we'll call that + + align:start position:0% +its output frequency we'll call that + + + align:start position:0% +its output frequency we'll call that +scale factor a subv and then finally we + + align:start position:0% +scale factor a subv and then finally we + + + align:start position:0% +scale factor a subv and then finally we +get the output frequency from the phase + + align:start position:0% +get the output frequency from the phase + + + align:start position:0% +get the output frequency from the phase +lock loop the interesting or the + + align:start position:0% +lock loop the interesting or the + + + align:start position:0% +lock loop the interesting or the +important thing here is that there's an + + align:start position:0% +important thing here is that there's an + + + align:start position:0% +important thing here is that there's an +intrinsic integration in this system + + align:start position:0% +intrinsic integration in this system + + + align:start position:0% +intrinsic integration in this system +that simply has to do with the + + align:start position:0% +that simply has to do with the + + + align:start position:0% +that simply has to do with the +conversion from frequency to phase we've + + align:start position:0% +conversion from frequency to phase we've + + + align:start position:0% +conversion from frequency to phase we've +seen that sort of a a thing before in + + align:start position:0% +seen that sort of a a thing before in + + + align:start position:0% +seen that sort of a a thing before in +other systems when we looked at + + align:start position:0% +other systems when we looked at + + + align:start position:0% +other systems when we looked at +mechanical systems that included a motor + + align:start position:0% +mechanical systems that included a motor + + + align:start position:0% +mechanical systems that included a motor +we remember that when we put a fixed + + align:start position:0% +we remember that when we put a fixed + + + align:start position:0% +we remember that when we put a fixed +voltage onto a motor we get a uh an + + align:start position:0% +voltage onto a motor we get a uh an + + + align:start position:0% +voltage onto a motor we get a uh an +output angle that's a progressive + + align:start position:0% +output angle that's a progressive + + + align:start position:0% +output angle that's a progressive +function of time if we have a fixed + + align:start position:0% +function of time if we have a fixed + + + align:start position:0% +function of time if we have a fixed +voltage in a motor we get a a ramp for + + align:start position:0% +voltage in a motor we get a a ramp for + + + align:start position:0% +voltage in a motor we get a a ramp for +the total output angle and so if we + + align:start position:0% +the total output angle and so if we + + + align:start position:0% +the total output angle and so if we +write the transfer function that relates + + align:start position:0% +write the transfer function that relates + + + align:start position:0% +write the transfer function that relates +input voltage to Output position or + + align:start position:0% +input voltage to Output position or + + + align:start position:0% +input voltage to Output position or +Theta we get a an integration in that + + align:start position:0% +Theta we get a an integration in that + + + align:start position:0% +Theta we get a an integration in that +transfer function here we have the same + + align:start position:0% +transfer function here we have the same + + + align:start position:0% +transfer function here we have the same +sort of a thing a physical process that + + align:start position:0% +sort of a thing a physical process that + + + align:start position:0% +sort of a thing a physical process that +gives us an + + align:start position:0% +gives us an + + + align:start position:0% +gives us an +integration there are several ways of + + align:start position:0% +integration there are several ways of + + + align:start position:0% +integration there are several ways of +modeling these incidentally you may have + + align:start position:0% +modeling these incidentally you may have + + + align:start position:0% +modeling these incidentally you may have +seen them done in a different way uh in + + align:start position:0% +seen them done in a different way uh in + + + align:start position:0% +seen them done in a different way uh in +some cases the block diagram itself is + + align:start position:0% +some cases the block diagram itself is + + + align:start position:0% +some cases the block diagram itself is +written in terms of phase rather than + + align:start position:0% +written in terms of phase rather than + + + align:start position:0% +written in terms of phase rather than +frequency the input being a phase + + align:start position:0% +frequency the input being a phase + + + align:start position:0% +frequency the input being a phase +command and then keep track of the + + align:start position:0% +command and then keep track of the + + + align:start position:0% +command and then keep track of the +output phase in that case the + + align:start position:0% +output phase in that case the + + + align:start position:0% +output phase in that case the +integration appears in conjunction with + + align:start position:0% +integration appears in conjunction with + + + align:start position:0% +integration appears in conjunction with +the voltage controlled oscillator since + + align:start position:0% +the voltage controlled oscillator since + + + align:start position:0% +the voltage controlled oscillator since +the input to the voltage controlled + + align:start position:0% +the input to the voltage controlled + + + align:start position:0% +the input to the voltage controlled +oscillator is a voltage the output is + + align:start position:0% +oscillator is a voltage the output is + + + align:start position:0% +oscillator is a voltage the output is +the total phase angle that the + + align:start position:0% +the total phase angle that the + + + align:start position:0% +the total phase angle that the +oscillator has has traversed or has gone + + align:start position:0% +oscillator has has traversed or has gone + + + align:start position:0% +oscillator has has traversed or has gone +through in that case we rearrange the + + align:start position:0% +through in that case we rearrange the + + + align:start position:0% +through in that case we rearrange the +block diagram a little bit we get the + + align:start position:0% +block diagram a little bit we get the + + + align:start position:0% +block diagram a little bit we get the +integration appearing in a different + + align:start position:0% +integration appearing in a different + + + align:start position:0% +integration appearing in a different +place in the block diagram but of course + + align:start position:0% +place in the block diagram but of course + + + align:start position:0% +place in the block diagram but of course +there's still the single + + align:start position:0% +there's still the single + + + align:start position:0% +there's still the single +integration well how do we mechanize the + + align:start position:0% +integration well how do we mechanize the + + + align:start position:0% +integration well how do we mechanize the +phase detector that's an important + + align:start position:0% +phase detector that's an important + + + align:start position:0% +phase detector that's an important +consideration in this type of + + align:start position:0% +consideration in this type of + + + align:start position:0% +consideration in this type of +system there are a number of ways and + + align:start position:0% +system there are a number of ways and + + + align:start position:0% +system there are a number of ways and +and they differ particularly in their + + align:start position:0% +and they differ particularly in their + + + align:start position:0% +and they differ particularly in their +large signal Behavior one very simple + + align:start position:0% +large signal Behavior one very simple + + + align:start position:0% +large signal Behavior one very simple +way is to use an exclusive orgate if the + + align:start position:0% +way is to use an exclusive orgate if the + + + align:start position:0% +way is to use an exclusive orgate if the +input signal and the output signal of + + align:start position:0% +input signal and the output signal of + + + align:start position:0% +input signal and the output signal of +our phase locked Loop are both digital + + align:start position:0% +our phase locked Loop are both digital + + + align:start position:0% +our phase locked Loop are both digital +signals let's look at how that might + + align:start position:0% +signals let's look at how that might + + + align:start position:0% +signals let's look at how that might +work suppose our commanded frequency is + + align:start position:0% +work suppose our commanded frequency is + + + align:start position:0% +work suppose our commanded frequency is +the digital signal with a phase as + + align:start position:0% +the digital signal with a phase as + + + align:start position:0% +the digital signal with a phase as +shown and assume that the response of + + align:start position:0% +shown and assume that the response of + + + align:start position:0% +shown and assume that the response of +the system is again a digital signal + + align:start position:0% +the system is again a digital signal + + + align:start position:0% +the system is again a digital signal +phase shifted by 90° In Time by a + + align:start position:0% +phase shifted by 90° In Time by a + + + align:start position:0% +phase shifted by 90° In Time by a +quarter of a cycle uh if we applied + + align:start position:0% +quarter of a cycle uh if we applied + + + align:start position:0% +quarter of a cycle uh if we applied +those two digital signals to an + + align:start position:0% +those two digital signals to an + + + align:start position:0% +those two digital signals to an +exclusive orgate we'd get the following + + align:start position:0% +exclusive orgate we'd get the following + + + align:start position:0% +exclusive orgate we'd get the following +output from the phase detector itself if + + align:start position:0% +output from the phase detector itself if + + + align:start position:0% +output from the phase detector itself if +we used simply an exclusive orgate as + + align:start position:0% +we used simply an exclusive orgate as + + + align:start position:0% +we used simply an exclusive orgate as +the phase detector we'd get the + + align:start position:0% +the phase detector we'd get the + + + align:start position:0% +the phase detector we'd get the +following kind of an output uh here in + + align:start position:0% +following kind of an output uh here in + + + align:start position:0% +following kind of an output uh here in +this time interval one of the signals is + + align:start position:0% +this time interval one of the signals is + + + align:start position:0% +this time interval one of the signals is +high consequently the output of the + + align:start position:0% +high consequently the output of the + + + align:start position:0% +high consequently the output of the +exclusive orgate is high uh in this + + align:start position:0% +exclusive orgate is high uh in this + + + align:start position:0% +exclusive orgate is high uh in this +period both both inputs to the XR gate + + align:start position:0% +period both both inputs to the XR gate + + + align:start position:0% +period both both inputs to the XR gate +are are high the output of the XR gate + + align:start position:0% +are are high the output of the XR gate + + + align:start position:0% +are are high the output of the XR gate +is low here again one signal is high + + align:start position:0% +is low here again one signal is high + + + align:start position:0% +is low here again one signal is high +only one is high the output of the xor + + align:start position:0% +only one is high the output of the xor + + + align:start position:0% +only one is high the output of the xor +is high here uh they're both low the + + align:start position:0% +is high here uh they're both low the + + + align:start position:0% +is high here uh they're both low the +output of the xor is low the information + + align:start position:0% +output of the xor is low the information + + + align:start position:0% +output of the xor is low the information +we're interested in is really the + + align:start position:0% +we're interested in is really the + + + align:start position:0% +we're interested in is really the +average value of this signal and so to + + align:start position:0% +average value of this signal and so to + + + align:start position:0% +average value of this signal and so to +complete the phase detection process uh + + align:start position:0% +complete the phase detection process uh + + + align:start position:0% +complete the phase detection process uh +we might standardize levels not allow + + align:start position:0% +we might standardize levels not allow + + + align:start position:0% +we might standardize levels not allow +them the ambiguity associated with + + align:start position:0% +them the ambiguity associated with + + + align:start position:0% +them the ambiguity associated with +normal digital levels we go through some + + align:start position:0% +normal digital levels we go through some + + + align:start position:0% +normal digital levels we go through some +sort of an analog switch so that we got + + align:start position:0% +sort of an analog switch so that we got + + + align:start position:0% +sort of an analog switch so that we got +standard levels coming out of our + + align:start position:0% +standard levels coming out of our + + + align:start position:0% +standard levels coming out of our +exclusive orgate and then go through a + + align:start position:0% +exclusive orgate and then go through a + + + align:start position:0% +exclusive orgate and then go through a +low pass filter that extracted the + + align:start position:0% +low pass filter that extracted the + + + align:start position:0% +low pass filter that extracted the +average value of the uh output from the + + align:start position:0% +average value of the uh output from the + + + align:start position:0% +average value of the uh output from the +exclusive orgate in this particular case + + align:start position:0% +exclusive orgate in this particular case + + + align:start position:0% +exclusive orgate in this particular case +where we have a 90° relative phase shift + + align:start position:0% +where we have a 90° relative phase shift + + + align:start position:0% +where we have a 90° relative phase shift +between the command signal and the + + align:start position:0% +between the command signal and the + + + align:start position:0% +between the command signal and the +response of the system the average value + + align:start position:0% +response of the system the average value + + + align:start position:0% +response of the system the average value +of the signal out of the exclusive + + align:start position:0% +of the signal out of the exclusive + + + align:start position:0% +of the signal out of the exclusive +orgate would be simply 1/2 of its + + align:start position:0% +orgate would be simply 1/2 of its + + + align:start position:0% +orgate would be simply 1/2 of its +maximum value since it spends half its + + align:start position:0% +maximum value since it spends half its + + + align:start position:0% +maximum value since it spends half its +time in the high and half its time in + + align:start position:0% +time in the high and half its time in + + + align:start position:0% +time in the high and half its time in +the low State again I think you notice + + align:start position:0% +the low State again I think you notice + + + align:start position:0% +the low State again I think you notice +the same sort of a thing as we had in + + align:start position:0% +the same sort of a thing as we had in + + + align:start position:0% +the same sort of a thing as we had in +one of the oscillator examples before + + align:start position:0% +one of the oscillator examples before + + + align:start position:0% +one of the oscillator examples before +where we have a high frequency process + + align:start position:0% +where we have a high frequency process + + + align:start position:0% +where we have a high frequency process +going on the exclusive orgate in this + + align:start position:0% +going on the exclusive orgate in this + + + align:start position:0% +going on the exclusive orgate in this +case is running at twice the operating + + align:start position:0% +case is running at twice the operating + + + align:start position:0% +case is running at twice the operating +frequency of the loop for this + + align:start position:0% +frequency of the loop for this + + + align:start position:0% +frequency of the loop for this +particular combination of inputs the + + align:start position:0% +particular combination of inputs the + + + align:start position:0% +particular combination of inputs the +output is a double frequency component + + align:start position:0% +output is a double frequency component + + + align:start position:0% +output is a double frequency component +plus a low frequency in this case a DC + + align:start position:0% +plus a low frequency in this case a DC + + + align:start position:0% +plus a low frequency in this case a DC +component if there's no change in the + + align:start position:0% +component if there's no change in the + + + align:start position:0% +component if there's no change in the +relative phase between the two signals + + align:start position:0% +relative phase between the two signals + + + align:start position:0% +relative phase between the two signals +uh what we're interested in and the + + align:start position:0% +uh what we're interested in and the + + + align:start position:0% +uh what we're interested in and the +information is contained in the average + + align:start position:0% +information is contained in the average + + + align:start position:0% +information is contained in the average +value of the signal so we have to apply + + align:start position:0% +value of the signal so we have to apply + + + align:start position:0% +value of the signal so we have to apply +some filtering there's some sampling + + align:start position:0% +some filtering there's some sampling + + + align:start position:0% +some filtering there's some sampling +going on we we have sampling kinds of + + align:start position:0% +going on we we have sampling kinds of + + + align:start position:0% +going on we we have sampling kinds of +problems here and that puts a very real + + align:start position:0% +problems here and that puts a very real + + + align:start position:0% +problems here and that puts a very real +limit on the crossover frequency of the + + align:start position:0% +limit on the crossover frequency of the + + + align:start position:0% +limit on the crossover frequency of the +loop and as we did in the case of the + + align:start position:0% +loop and as we did in the case of the + + + align:start position:0% +loop and as we did in the case of the +oscillator whose amplitude was + + align:start position:0% +oscillator whose amplitude was + + + align:start position:0% +oscillator whose amplitude was +controlled we argued that to eliminate + + align:start position:0% +controlled we argued that to eliminate + + + align:start position:0% +controlled we argued that to eliminate +those sorts of problems we cross over in + + align:start position:0% +those sorts of problems we cross over in + + + align:start position:0% +those sorts of problems we cross over in +this kind of a loop at a very small + + align:start position:0% +this kind of a loop at a very small + + + align:start position:0% +this kind of a loop at a very small +fraction of the operating frequency here + + align:start position:0% +fraction of the operating frequency here + + + align:start position:0% +fraction of the operating frequency here +we intend to cross over at a small + + align:start position:0% +we intend to cross over at a small + + + align:start position:0% +we intend to cross over at a small +fraction of f subc or F + + align:start position:0% +fraction of f subc or F + + + align:start position:0% +fraction of f subc or F +subr and by doing that we're able to + + align:start position:0% +subr and by doing that we're able to + + + align:start position:0% +subr and by doing that we're able to +easily extract the average value of this + + align:start position:0% +easily extract the average value of this + + + align:start position:0% +easily extract the average value of this +signal to use as a a phase indication + + align:start position:0% +signal to use as a a phase indication + + + align:start position:0% +signal to use as a a phase indication +let's consider what happens if the + + align:start position:0% +let's consider what happens if the + + + align:start position:0% +let's consider what happens if the +relative phase between the input and the + + align:start position:0% +relative phase between the input and the + + + align:start position:0% +relative phase between the input and the +output signals change such that now the + + align:start position:0% +output signals change such that now the + + + align:start position:0% +output signals change such that now the +response of the system the second + + align:start position:0% +response of the system the second + + + align:start position:0% +response of the system the second +response of the system is in fact in + + align:start position:0% +response of the system is in fact in + + + align:start position:0% +response of the system is in fact in +Phase with the command signal so we have + + align:start position:0% +Phase with the command signal so we have + + + align:start position:0% +Phase with the command signal so we have +one that that's directly in Phase with + + align:start position:0% +one that that's directly in Phase with + + + align:start position:0% +one that that's directly in Phase with +the command signal in that case the + + align:start position:0% +the command signal in that case the + + + align:start position:0% +the command signal in that case the +output of our exclusive orgate is always + + align:start position:0% +output of our exclusive orgate is always + + + align:start position:0% +output of our exclusive orgate is always +low so this would be the output from the + + align:start position:0% +low so this would be the output from the + + + align:start position:0% +low so this would be the output from the +exclusive orgate that corresponds to + + align:start position:0% +exclusive orgate that corresponds to + + + align:start position:0% +exclusive orgate that corresponds to +this second response from the + + align:start position:0% +this second response from the + + + align:start position:0% +this second response from the +system uh if we average that of course + + align:start position:0% +system uh if we average that of course + + + align:start position:0% +system uh if we average that of course +we'd get zero if we average the output + + align:start position:0% +we'd get zero if we average the output + + + align:start position:0% +we'd get zero if we average the output +of the exclusive orgate when the two + + align:start position:0% +of the exclusive orgate when the two + + + align:start position:0% +of the exclusive orgate when the two +signals are 90 degrees out of phase we + + align:start position:0% +signals are 90 degrees out of phase we + + + align:start position:0% +signals are 90 degrees out of phase we +get half of full scale uh if we + + align:start position:0% +get half of full scale uh if we + + + align:start position:0% +get half of full scale uh if we +continued this and looked at what + + align:start position:0% +continued this and looked at what + + + align:start position:0% +continued this and looked at what +happened when the response of the system + + align:start position:0% +happened when the response of the system + + + align:start position:0% +happened when the response of the system +was 180° out of phase with the command + + align:start position:0% +was 180° out of phase with the command + + + align:start position:0% +was 180° out of phase with the command +frequency we'd find out that the output + + align:start position:0% +frequency we'd find out that the output + + + align:start position:0% +frequency we'd find out that the output +of the exclusive orgate was always in + + align:start position:0% +of the exclusive orgate was always in + + + align:start position:0% +of the exclusive orgate was always in +its high state if we averaged that we'd + + align:start position:0% +its high state if we averaged that we'd + + + align:start position:0% +its high state if we averaged that we'd +get the high level and so if we look at + + align:start position:0% +get the high level and so if we look at + + + align:start position:0% +get the high level and so if we look at +the average value of the output from the + + align:start position:0% +the average value of the output from the + + + align:start position:0% +the average value of the output from the +exclusive orgate as a function of the + + align:start position:0% +exclusive orgate as a function of the + + + align:start position:0% +exclusive orgate as a function of the +relative phase shift between the two + + align:start position:0% +relative phase shift between the two + + + align:start position:0% +relative phase shift between the two +signals which I've called Alpha we get a + + align:start position:0% +signals which I've called Alpha we get a + + + align:start position:0% +signals which I've called Alpha we get a +a signal that is uh 0 for 0 deg of + + align:start position:0% +a signal that is uh 0 for 0 deg of + + + align:start position:0% +a signal that is uh 0 for 0 deg of +relative phase + + align:start position:0% +relative phase + + + align:start position:0% +relative phase +uh is half of Maximum value for 90° of + + align:start position:0% +uh is half of Maximum value for 90° of + + + align:start position:0% +uh is half of Maximum value for 90° of +relative phase reaches the maximum value + + align:start position:0% +relative phase reaches the maximum value + + + align:start position:0% +relative phase reaches the maximum value +for 180 degrees of relative phase if we + + align:start position:0% +for 180 degrees of relative phase if we + + + align:start position:0% +for 180 degrees of relative phase if we +continued this we'd find out that we'd + + align:start position:0% +continued this we'd find out that we'd + + + align:start position:0% +continued this we'd find out that we'd +have a triangular function that comes + + align:start position:0% +have a triangular function that comes + + + align:start position:0% +have a triangular function that comes +back down uh once again reaching 0 degre + + align:start position:0% +back down uh once again reaching 0 degre + + + align:start position:0% +back down uh once again reaching 0 degre +when we've accumulated a total phase + + align:start position:0% +when we've accumulated a total phase + + + align:start position:0% +when we've accumulated a total phase +difference of + + align:start position:0% +difference of + + + align:start position:0% +difference of +360° between the uh two signals uh the + + align:start position:0% +360° between the uh two signals uh the + + + align:start position:0% +360° between the uh two signals uh the +error pattern the average value of the + + align:start position:0% +error pattern the average value of the + + + align:start position:0% +error pattern the average value of the +exclusive ore output signal has a + + align:start position:0% +exclusive ore output signal has a + + + align:start position:0% +exclusive ore output signal has a +function of relative phase angle between + + align:start position:0% +function of relative phase angle between + + + align:start position:0% +function of relative phase angle between +the two input signals is cyclical uh + + align:start position:0% +the two input signals is cyclical uh + + + align:start position:0% +the two input signals is cyclical uh +repeats every + + align:start position:0% +repeats every + + + align:start position:0% +repeats every +360° it exhibits both positive and + + align:start position:0% +360° it exhibits both positive and + + + align:start position:0% +360° it exhibits both positive and +negative slopes if we look at the full 0 + + align:start position:0% +negative slopes if we look at the full 0 + + + align:start position:0% +negative slopes if we look at the full 0 +to three 360 Dee range uh one of those + + align:start position:0% +to three 360 Dee range uh one of those + + + align:start position:0% +to three 360 Dee range uh one of those +when we build a loop will represent a + + align:start position:0% +when we build a loop will represent a + + + align:start position:0% +when we build a loop will represent a +point where we have positive feedback + + align:start position:0% +point where we have positive feedback + + + align:start position:0% +point where we have positive feedback +one will represent a point where we have + + align:start position:0% +one will represent a point where we have + + + align:start position:0% +one will represent a point where we have +negative feedback in the loop uh let's + + align:start position:0% +negative feedback in the loop uh let's + + + align:start position:0% +negative feedback in the loop uh let's +assume that this slope gives us negative + + align:start position:0% +assume that this slope gives us negative + + + align:start position:0% +assume that this slope gives us negative +feedback and our our overall Loop we'd + + align:start position:0% +feedback and our our overall Loop we'd + + + align:start position:0% +feedback and our our overall Loop we'd +then presumably try to arrange the loop + + align:start position:0% +then presumably try to arrange the loop + + + align:start position:0% +then presumably try to arrange the loop +so that its operating point was + + align:start position:0% +so that its operating point was + + + align:start position:0% +so that its operating point was +somewhere in here that would allow us a + + align:start position:0% +somewhere in here that would allow us a + + + align:start position:0% +somewhere in here that would allow us a +maximum of plus or minus 90° of phase + + align:start position:0% +maximum of plus or minus 90° of phase + + + align:start position:0% +maximum of plus or minus 90° of phase +deviation between the two signals before + + align:start position:0% +deviation between the two signals before + + + align:start position:0% +deviation between the two signals before +we had a phase reversal a polarity + + align:start position:0% +we had a phase reversal a polarity + + + align:start position:0% +we had a phase reversal a polarity +reversal in the loop so we'd have a + + align:start position:0% +reversal in the loop so we'd have a + + + align:start position:0% +reversal in the loop so we'd have a +total range over which the loop would + + align:start position:0% +total range over which the loop would + + + align:start position:0% +total range over which the loop would +hopefully work normally of plus or minus + + align:start position:0% +hopefully work normally of plus or minus + + + align:start position:0% +hopefully work normally of plus or minus +90 degrees of relative phase between the + + align:start position:0% +90 degrees of relative phase between the + + + align:start position:0% +90 degrees of relative phase between the +two signals there are a lot of other + + align:start position:0% +two signals there are a lot of other + + + align:start position:0% +two signals there are a lot of other +ways to do a phase detection uh for + + align:start position:0% +ways to do a phase detection uh for + + + align:start position:0% +ways to do a phase detection uh for +example we can get much the same kind of + + align:start position:0% +example we can get much the same kind of + + + align:start position:0% +example we can get much the same kind of +thing as we do in the exclusive orgate a + + align:start position:0% +thing as we do in the exclusive orgate a + + + align:start position:0% +thing as we do in the exclusive orgate a +little bit of different detail about the + + align:start position:0% +little bit of different detail about the + + + align:start position:0% +little bit of different detail about the +way the pattern repeats if we simply use + + align:start position:0% +way the pattern repeats if we simply use + + + align:start position:0% +way the pattern repeats if we simply use +a set reset flipflop as the phase + + align:start position:0% +a set reset flipflop as the phase + + + align:start position:0% +a set reset flipflop as the phase +detector set it on one of our signals + + align:start position:0% +detector set it on one of our signals + + + align:start position:0% +detector set it on one of our signals +reset it on the second signal again if + + align:start position:0% +reset it on the second signal again if + + + align:start position:0% +reset it on the second signal again if +the two signals in that case are are 180 + + align:start position:0% +the two signals in that case are are 180 + + + align:start position:0% +the two signals in that case are are 180 +de out of phase we'd find out that the + + align:start position:0% +de out of phase we'd find out that the + + + align:start position:0% +de out of phase we'd find out that the +duty cycle of the flip-flop would be 50% + + align:start position:0% +duty cycle of the flip-flop would be 50% + + + align:start position:0% +duty cycle of the flip-flop would be 50% +it would spend half its time in each + + align:start position:0% +it would spend half its time in each + + + align:start position:0% +it would spend half its time in each +state we'd once again average that out + + align:start position:0% +state we'd once again average that out + + + align:start position:0% +state we'd once again average that out +put and we if we Chase through the + + align:start position:0% +put and we if we Chase through the + + + align:start position:0% +put and we if we Chase through the +relationships uh assuming we're setting + + align:start position:0% +relationships uh assuming we're setting + + + align:start position:0% +relationships uh assuming we're setting +on on one of our signals and resetting + + align:start position:0% +on on one of our signals and resetting + + + align:start position:0% +on on one of our signals and resetting +on the other we'd find out that we get a + + align:start position:0% +on the other we'd find out that we get a + + + align:start position:0% +on the other we'd find out that we get a +signal proportional to the the average + + align:start position:0% +signal proportional to the the average + + + align:start position:0% +signal proportional to the the average +value of the flip-flop output would be + + align:start position:0% +value of the flip-flop output would be + + + align:start position:0% +value of the flip-flop output would be +proportional to the relative phase + + align:start position:0% +proportional to the relative phase + + + align:start position:0% +proportional to the relative phase +difference between the two digital + + align:start position:0% +difference between the two digital + + + align:start position:0% +difference between the two digital +signals for an example of this sort of + + align:start position:0% +signals for an example of this sort of + + + align:start position:0% +signals for an example of this sort of +of system we're going to look at a + + align:start position:0% +of system we're going to look at a + + + align:start position:0% +of system we're going to look at a +commercially available integrated + + align:start position:0% +commercially available integrated + + + align:start position:0% +commercially available integrated +circuit phase lock loop a type 565 which + + align:start position:0% +circuit phase lock loop a type 565 which + + + align:start position:0% +circuit phase lock loop a type 565 which +has been around a while + + align:start position:0% +has been around a while + + + align:start position:0% +has been around a while +it uh uh uses a different kind of a + + align:start position:0% +it uh uh uses a different kind of a + + + align:start position:0% +it uh uh uses a different kind of a +phase + + align:start position:0% +phase + + + align:start position:0% +phase +detector in the + + align:start position:0% +detector in the + + + align:start position:0% +detector in the +565 the reference signal the input uh + + align:start position:0% +565 the reference signal the input uh + + + align:start position:0% +565 the reference signal the input uh +the command signal uh actually in in + + align:start position:0% +the command signal uh actually in in + + + align:start position:0% +the command signal uh actually in in +the phase locked + + align:start position:0% +the phase locked + + + align:start position:0% +the phase locked +Loop is a Soso we get a a sidal input + + align:start position:0% +Loop is a Soso we get a a sidal input + + + align:start position:0% +Loop is a Soso we get a a sidal input +the signal that's fed back is actually a + + align:start position:0% +the signal that's fed back is actually a + + + align:start position:0% +the signal that's fed back is actually a +two-level signal a digital kind of a + + align:start position:0% +two-level signal a digital kind of a + + + align:start position:0% +two-level signal a digital kind of a +signal + + align:start position:0% +signal + + + align:start position:0% +signal +Square wave sort of a thing and the + + align:start position:0% +Square wave sort of a thing and the + + + align:start position:0% +Square wave sort of a thing and the +phase detector used in the 565 basically + + align:start position:0% +phase detector used in the 565 basically + + + align:start position:0% +phase detector used in the 565 basically +performs a multiplication of these two + + align:start position:0% +performs a multiplication of these two + + + align:start position:0% +performs a multiplication of these two +signals and then once again averages the + + align:start position:0% +signals and then once again averages the + + + align:start position:0% +signals and then once again averages the +output uh and we can look at the + + align:start position:0% +output uh and we can look at the + + + align:start position:0% +output uh and we can look at the +operation of that again we assume a + + align:start position:0% +operation of that again we assume a + + + align:start position:0% +operation of that again we assume a +relative phase angle Alpha between the + + align:start position:0% +relative phase angle Alpha between the + + + align:start position:0% +relative phase angle Alpha between the +two signals uh here if Alpha were zero + + align:start position:0% +two signals uh here if Alpha were zero + + + align:start position:0% +two signals uh here if Alpha were zero +we would get as the output of the phase + + align:start position:0% +we would get as the output of the phase + + + align:start position:0% +we would get as the output of the phase +detector uh the product these two + + align:start position:0% +detector uh the product these two + + + align:start position:0% +detector uh the product these two +signals we'd effectively get a full wave + + align:start position:0% +signals we'd effectively get a full wave + + + align:start position:0% +signals we'd effectively get a full wave +rectified sine wave if Alpha were zero + + align:start position:0% +rectified sine wave if Alpha were zero + + + align:start position:0% +rectified sine wave if Alpha were zero +we'd multiply this part of the sine wave + + align:start position:0% +we'd multiply this part of the sine wave + + + align:start position:0% +we'd multiply this part of the sine wave +by+ one this part by minus one which + + align:start position:0% +by+ one this part by minus one which + + + align:start position:0% +by+ one this part by minus one which +would flip it over so the output from + + align:start position:0% +would flip it over so the output from + + + align:start position:0% +would flip it over so the output from +the phase detector prior to filtering + + align:start position:0% +the phase detector prior to filtering + + + align:start position:0% +the phase detector prior to filtering +would be a full wave rectified sine wave + + align:start position:0% +would be a full wave rectified sine wave + + + align:start position:0% +would be a full wave rectified sine wave +uh if we have 90 degrees of relative + + align:start position:0% +uh if we have 90 degrees of relative + + + align:start position:0% +uh if we have 90 degrees of relative +phase shift we find out that the average + + align:start position:0% +phase shift we find out that the average + + + align:start position:0% +phase shift we find out that the average +value of the output is zero uh we get + + align:start position:0% +value of the output is zero uh we get + + + align:start position:0% +value of the output is zero uh we get +little segments that are this segment + + align:start position:0% +little segments that are this segment + + + align:start position:0% +little segments that are this segment +and that kind of AOS soidal segment when + + align:start position:0% +and that kind of AOS soidal segment when + + + align:start position:0% +and that kind of AOS soidal segment when +we average those we get zero for an + + align:start position:0% +we average those we get zero for an + + + align:start position:0% +we average those we get zero for an +output when there's 180 degrees of + + align:start position:0% +output when there's 180 degrees of + + + align:start position:0% +output when there's 180 degrees of +relative phase shift uh we get a + + align:start position:0% +relative phase shift uh we get a + + + align:start position:0% +relative phase shift uh we get a +negative full wave rectified sine wave + + align:start position:0% +negative full wave rectified sine wave + + + align:start position:0% +negative full wave rectified sine wave +when Alpha is such that we multiply this + + align:start position:0% +when Alpha is such that we multiply this + + + align:start position:0% +when Alpha is such that we multiply this +part by minus one this part by plus one + + align:start position:0% +part by minus one this part by plus one + + + align:start position:0% +part by minus one this part by plus one +when we have 180 degrees of relative + + align:start position:0% +when we have 180 degrees of relative + + + align:start position:0% +when we have 180 degrees of relative +phase shift we get a negative full wave + + align:start position:0% +phase shift we get a negative full wave + + + align:start position:0% +phase shift we get a negative full wave +rectified sine wave and so we get a + + align:start position:0% +rectified sine wave and so we get a + + + align:start position:0% +rectified sine wave and so we get a +maximum negative average value if we + + align:start position:0% +maximum negative average value if we + + + align:start position:0% +maximum negative average value if we +keep track of those relation ships this + + align:start position:0% +keep track of those relation ships this + + + align:start position:0% +keep track of those relation ships this +sort of a phase detector or the average + + align:start position:0% +sort of a phase detector or the average + + + align:start position:0% +sort of a phase detector or the average +value out of this sort of a phase + + align:start position:0% +value out of this sort of a phase + + + align:start position:0% +value out of this sort of a phase +detector gives us a transfer function or + + align:start position:0% +detector gives us a transfer function or + + + align:start position:0% +detector gives us a transfer function or +a transfer relationship like so a + + align:start position:0% +a transfer relationship like so a + + + align:start position:0% +a transfer relationship like so a +sinusoidal picture uh if we normalize + + align:start position:0% +sinusoidal picture uh if we normalize + + + align:start position:0% +sinusoidal picture uh if we normalize +things so that the slope is one in here + + align:start position:0% +things so that the slope is one in here + + + align:start position:0% +things so that the slope is one in here +uh we hit a maximum value of 2 over Pi + + align:start position:0% +uh we hit a maximum value of 2 over Pi + + + align:start position:0% +uh we hit a maximum value of 2 over Pi +at the extremes uh or minus 2 over Pi at + + align:start position:0% +at the extremes uh or minus 2 over Pi at + + + align:start position:0% +at the extremes uh or minus 2 over Pi at +The Other Extreme again this is cyclical + + align:start position:0% +The Other Extreme again this is cyclical + + + align:start position:0% +The Other Extreme again this is cyclical +it repeats uh we get uh points of + + align:start position:0% +it repeats uh we get uh points of + + + align:start position:0% +it repeats uh we get uh points of +positive feedback or points of negative + + align:start position:0% +positive feedback or points of negative + + + align:start position:0% +positive feedback or points of negative +feedback displaced from each other by + + align:start position:0% +feedback displaced from each other by + + + align:start position:0% +feedback displaced from each other by +180° of relative phase shift uh only one + + align:start position:0% +180° of relative phase shift uh only one + + + align:start position:0% +180° of relative phase shift uh only one +of these sets of points will be a stable + + align:start position:0% +of these sets of points will be a stable + + + align:start position:0% +of these sets of points will be a stable +equilibrium for the loop the other one + + align:start position:0% +equilibrium for the loop the other one + + + align:start position:0% +equilibrium for the loop the other one +of course will be a positive Fe feedback + + align:start position:0% +of course will be a positive Fe feedback + + + align:start position:0% +of course will be a positive Fe feedback +Point uh in many phase lock Loops we + + align:start position:0% +Point uh in many phase lock Loops we + + + align:start position:0% +Point uh in many phase lock Loops we +intentionally include an additional + + align:start position:0% +intentionally include an additional + + + align:start position:0% +intentionally include an additional +integration in the loop we indicated + + align:start position:0% +integration in the loop we indicated + + + align:start position:0% +integration in the loop we indicated +there was one inherent integration that + + align:start position:0% +there was one inherent integration that + + + align:start position:0% +there was one inherent integration that +has to do with the conversion from + + align:start position:0% +has to do with the conversion from + + + align:start position:0% +has to do with the conversion from +frequency to phase but in many other in + + align:start position:0% +frequency to phase but in many other in + + + align:start position:0% +frequency to phase but in many other in +many Loops we include an additional + + align:start position:0% +many Loops we include an additional + + + align:start position:0% +many Loops we include an additional +integration and the reason for that is + + align:start position:0% +integration and the reason for that is + + + align:start position:0% +integration and the reason for that is +so that under steady state conditions we + + align:start position:0% +so that under steady state conditions we + + + align:start position:0% +so that under steady state conditions we +get zero phase error in the system if we + + align:start position:0% +get zero phase error in the system if we + + + align:start position:0% +get zero phase error in the system if we +have one more integration following the + + align:start position:0% +have one more integration following the + + + align:start position:0% +have one more integration following the +phase detector and if we can stabilize + + align:start position:0% +phase detector and if we can stabilize + + + align:start position:0% +phase detector and if we can stabilize +the loop why the additional integration + + align:start position:0% +the loop why the additional integration + + + align:start position:0% +the loop why the additional integration +would tell us that under static + + align:start position:0% +would tell us that under static + + + align:start position:0% +would tell us that under static +conditions when the signals are time + + align:start position:0% +conditions when the signals are time + + + align:start position:0% +conditions when the signals are time +invariant the loop will work to drive + + align:start position:0% +invariant the loop will work to drive + + + align:start position:0% +invariant the loop will work to drive +the signal out of the phase detector to + + align:start position:0% +the signal out of the phase detector to + + + align:start position:0% +the signal out of the phase detector to +zero and or to its operating point + + align:start position:0% +zero and or to its operating point + + + align:start position:0% +zero and or to its operating point +exactly to its operating point so we'll + + align:start position:0% +exactly to its operating point so we'll + + + align:start position:0% +exactly to its operating point so we'll +end up with a system that has zero + + align:start position:0% +end up with a system that has zero + + + align:start position:0% +end up with a system that has zero +relative phase error whatever the + + align:start position:0% +relative phase error whatever the + + + align:start position:0% +relative phase error whatever the +operating point is in some of these + + align:start position:0% +operating point is in some of these + + + align:start position:0% +operating point is in some of these +detectors for example the operating + + align:start position:0% +detectors for example the operating + + + align:start position:0% +detectors for example the operating +Point's 90° apart in some it's 180° + + align:start position:0% +Point's 90° apart in some it's 180° + + + align:start position:0% +Point's 90° apart in some it's 180° +apart but if we included an an + + align:start position:0% +apart but if we included an an + + + align:start position:0% +apart but if we included an an +additional integration when the input + + align:start position:0% +additional integration when the input + + + align:start position:0% +additional integration when the input +frequency were constant we drive to that + + align:start position:0% +frequency were constant we drive to that + + + align:start position:0% +frequency were constant we drive to that +equilibrium point exactly the 565 + + align:start position:0% +equilibrium point exactly the 565 + + + align:start position:0% +equilibrium point exactly the 565 +doesn't include that the output of the + + align:start position:0% +doesn't include that the output of the + + + align:start position:0% +doesn't include that the output of the +phase detector can be modeled in the 565 + + align:start position:0% +phase detector can be modeled in the 565 + + + align:start position:0% +phase detector can be modeled in the 565 +as some sort of a thant equivalent with + + align:start position:0% +as some sort of a thant equivalent with + + + align:start position:0% +as some sort of a thant equivalent with +a voltage generator proportional to the + + align:start position:0% +a voltage generator proportional to the + + + align:start position:0% +a voltage generator proportional to the +phase error and some output resistance + + align:start position:0% +phase error and some output resistance + + + align:start position:0% +phase error and some output resistance +you mechanize the loop filter in the + + align:start position:0% +you mechanize the loop filter in the + + + align:start position:0% +you mechanize the loop filter in the +565 by adding some components external + + align:start position:0% +565 by adding some components external + + + align:start position:0% +565 by adding some components external +to this thonon equivalent bya an a + + align:start position:0% +to this thonon equivalent bya an a + + + align:start position:0% +to this thonon equivalent bya an a +terminal on the integrated circuit and + + align:start position:0% +terminal on the integrated circuit and + + + align:start position:0% +terminal on the integrated circuit and +then this signal continues on uh inside + + align:start position:0% +then this signal continues on uh inside + + + align:start position:0% +then this signal continues on uh inside +the integrated circuit to change the + + align:start position:0% +the integrated circuit to change the + + + align:start position:0% +the integrated circuit to change the +frequency of operation of the voltage + + align:start position:0% +frequency of operation of the voltage + + + align:start position:0% +frequency of operation of the voltage +controlled oscillator this signal is the + + align:start position:0% +controlled oscillator this signal is the + + + align:start position:0% +controlled oscillator this signal is the +one applied to the + + align:start position:0% +one applied to the + + + align:start position:0% +one applied to the +vco well one thing we might do is simply + + align:start position:0% +vco well one thing we might do is simply + + + align:start position:0% +vco well one thing we might do is simply +add a capacitor which I've chosen to + + align:start position:0% +add a capacitor which I've chosen to + + + align:start position:0% +add a capacitor which I've chosen to +call C big uh across this pair of + + align:start position:0% +call C big uh across this pair of + + + align:start position:0% +call C big uh across this pair of +Terminals and that provides the + + align:start position:0% +Terminals and that provides the + + + align:start position:0% +Terminals and that provides the +filtering function the signal here is + + align:start position:0% +filtering function the signal here is + + + align:start position:0% +filtering function the signal here is +really the raw signal from the phase + + align:start position:0% +really the raw signal from the phase + + + align:start position:0% +really the raw signal from the phase +detector before filtering and we + + align:start position:0% +detector before filtering and we + + + align:start position:0% +detector before filtering and we +indicated we have to do some filtering + + align:start position:0% +indicated we have to do some filtering + + + align:start position:0% +indicated we have to do some filtering +we don't want to apply a Time varying + + align:start position:0% +we don't want to apply a Time varying + + + align:start position:0% +we don't want to apply a Time varying +signal to the phase detector so we might + + align:start position:0% +signal to the phase detector so we might + + + align:start position:0% +signal to the phase detector so we might +do that by simply putting a capacitor + + align:start position:0% +do that by simply putting a capacitor + + + align:start position:0% +do that by simply putting a capacitor +onto that + + align:start position:0% +onto that + + + align:start position:0% +onto that +terminal when we do that we might find + + align:start position:0% +terminal when we do that we might find + + + align:start position:0% +terminal when we do that we might find +uh the following kind of a plot of loop + + align:start position:0% +uh the following kind of a plot of loop + + + align:start position:0% +uh the following kind of a plot of loop +transmission magnitude versus frequency + + align:start position:0% +transmission magnitude versus frequency + + + align:start position:0% +transmission magnitude versus frequency +if the capacitor were large enough we'd + + align:start position:0% +if the capacitor were large enough we'd + + + align:start position:0% +if the capacitor were large enough we'd +get this sort of behavior we have a + + align:start position:0% +get this sort of behavior we have a + + + align:start position:0% +get this sort of behavior we have a +single integration at low frequencies + + align:start position:0% +single integration at low frequencies + + + align:start position:0% +single integration at low frequencies +some constant associated with that and + + align:start position:0% +some constant associated with that and + + + align:start position:0% +some constant associated with that and +then we get a pole that's equal to or + + align:start position:0% +then we get a pole that's equal to or + + + align:start position:0% +then we get a pole that's equal to or +located a frequency that's one over this + + align:start position:0% +located a frequency that's one over this + + + align:start position:0% +located a frequency that's one over this +RC product and beyond that poll we get a + + align:start position:0% +RC product and beyond that poll we get a + + + align:start position:0% +RC product and beyond that poll we get a +second order roll off we cross over with + + align:start position:0% +second order roll off we cross over with + + + align:start position:0% +second order roll off we cross over with +a slope of 1 over S + + align:start position:0% +a slope of 1 over S + + + align:start position:0% +a slope of 1 over S +squ as shown or at least if we had a + + align:start position:0% +squ as shown or at least if we had a + + + align:start position:0% +squ as shown or at least if we had a +sufficiently large capacitor that would + + align:start position:0% +sufficiently large capacitor that would + + + align:start position:0% +sufficiently large capacitor that would +happen and if we did this if we pushed + + align:start position:0% +happen and if we did this if we pushed + + + align:start position:0% +happen and if we did this if we pushed +the pole back to very low frequencies uh + + align:start position:0% +the pole back to very low frequencies uh + + + align:start position:0% +the pole back to very low frequencies uh +we'd have + + align:start position:0% +we'd have + + + align:start position:0% +we'd have +poorly stable performance we'd have low + + align:start position:0% +poorly stable performance we'd have low + + + align:start position:0% +poorly stable performance we'd have low +phase margin in the system uh we could + + align:start position:0% +phase margin in the system uh we could + + + align:start position:0% +phase margin in the system uh we could +of course uh use a smaller value + + align:start position:0% +of course uh use a smaller value + + + align:start position:0% +of course uh use a smaller value +capacitor uh one that was adequate for + + align:start position:0% +capacitor uh one that was adequate for + + + align:start position:0% +capacitor uh one that was adequate for +filtering the Ripple out of the phase + + align:start position:0% +filtering the Ripple out of the phase + + + align:start position:0% +filtering the Ripple out of the phase +detector but didn't create this problem + + align:start position:0% +detector but didn't create this problem + + + align:start position:0% +detector but didn't create this problem +however there's an alternative that can + + align:start position:0% +however there's an alternative that can + + + align:start position:0% +however there's an alternative that can +be used to give us somewhat higher + + align:start position:0% +be used to give us somewhat higher + + + align:start position:0% +be used to give us somewhat higher +desensitivity uh given that the + + align:start position:0% +desensitivity uh given that the + + + align:start position:0% +desensitivity uh given that the +crossover frequency is is more or less a + + align:start position:0% +crossover frequency is is more or less a + + + align:start position:0% +crossover frequency is is more or less a +fixed quantity because we have to cross + + align:start position:0% +fixed quantity because we have to cross + + + align:start position:0% +fixed quantity because we have to cross +over at a small fraction of the + + align:start position:0% +over at a small fraction of the + + + align:start position:0% +over at a small fraction of the +operating + + align:start position:0% +operating + + + align:start position:0% +operating +frequency um we can use a slightly more + + align:start position:0% +frequency um we can use a slightly more + + + align:start position:0% +frequency um we can use a slightly more +complicated Network at the outside of + + align:start position:0% +complicated Network at the outside of + + + align:start position:0% +complicated Network at the outside of +the package that looks something like + + align:start position:0% +the package that looks something like + + + align:start position:0% +the package that looks something like +this we have our C sub big which might + + align:start position:0% +this we have our C sub big which might + + + align:start position:0% +this we have our C sub big which might +be the same value as the C sub big + + align:start position:0% +be the same value as the C sub big + + + align:start position:0% +be the same value as the C sub big +before but then we can put a series + + align:start position:0% +before but then we can put a series + + + align:start position:0% +before but then we can put a series +resistance associated with that uh at + + align:start position:0% +resistance associated with that uh at + + + align:start position:0% +resistance associated with that uh at +high frequencies we get simply an + + align:start position:0% +high frequencies we get simply an + + + align:start position:0% +high frequencies we get simply an +attenuation between this point and this + + align:start position:0% +attenuation between this point and this + + + align:start position:0% +attenuation between this point and this +point then we get lag kinds of transfer + + align:start position:0% +point then we get lag kinds of transfer + + + align:start position:0% +point then we get lag kinds of transfer +functions out of that combination we + + align:start position:0% +functions out of that combination we + + + align:start position:0% +functions out of that combination we +might then put a smaller capacitor + + align:start position:0% +might then put a smaller capacitor + + + align:start position:0% +might then put a smaller capacitor +across this network that would provide + + align:start position:0% +across this network that would provide + + + align:start position:0% +across this network that would provide +additional Ripple filter ing at high + + align:start position:0% +additional Ripple filter ing at high + + + align:start position:0% +additional Ripple filter ing at high +frequency so the purpose of this is + + align:start position:0% +frequency so the purpose of this is + + + align:start position:0% +frequency so the purpose of this is +simply to provide Ripple filtering if we + + align:start position:0% +simply to provide Ripple filtering if we + + + align:start position:0% +simply to provide Ripple filtering if we +do that we can get a loop transmission + + align:start position:0% +do that we can get a loop transmission + + + align:start position:0% +do that we can get a loop transmission +magnitude that's generally of of this + + align:start position:0% +magnitude that's generally of of this + + + align:start position:0% +magnitude that's generally of of this +form we have a 1 overs kind of roll off + + align:start position:0% +form we have a 1 overs kind of roll off + + + align:start position:0% +form we have a 1 overs kind of roll off +at low + + align:start position:0% +at low + + + align:start position:0% +at low +frequencies at somewhat higher + + align:start position:0% +frequencies at somewhat higher + + + align:start position:0% +frequencies at somewhat higher +frequencies we get into the pole of the + + align:start position:0% +frequencies we get into the pole of the + + + align:start position:0% +frequencies we get into the pole of the +lag type transfer function and that pole + + align:start position:0% +lag type transfer function and that pole + + + align:start position:0% +lag type transfer function and that pole +location is of course uh given by the C + + align:start position:0% +location is of course uh given by the C + + + align:start position:0% +location is of course uh given by the C +subb and the uh sum of of these two + + align:start position:0% +subb and the uh sum of of these two + + + align:start position:0% +subb and the uh sum of of these two +resistors that RC product determines the + + align:start position:0% +resistors that RC product determines the + + + align:start position:0% +resistors that RC product determines the +pole location in the lag type transfer + + align:start position:0% +pole location in the lag type transfer + + + align:start position:0% +pole location in the lag type transfer +function we later get the zero + + align:start position:0% +function we later get the zero + + + align:start position:0% +function we later get the zero +associated with the lag type transfer + + align:start position:0% +associated with the lag type transfer + + + align:start position:0% +associated with the lag type transfer +function and we'd probably we'd + + align:start position:0% +function and we'd probably we'd + + + align:start position:0% +function and we'd probably we'd +presumably arrange things so that that + + align:start position:0% +presumably arrange things so that that + + + align:start position:0% +presumably arrange things so that that +zero occurred at a a frequency below + + align:start position:0% +zero occurred at a a frequency below + + + align:start position:0% +zero occurred at a a frequency below +crossover we can then cross over with + + align:start position:0% +crossover we can then cross over with + + + align:start position:0% +crossover we can then cross over with +acceptable phase margin in our system + + align:start position:0% +acceptable phase margin in our system + + + align:start position:0% +acceptable phase margin in our system +and then finally at a frequency well + + align:start position:0% +and then finally at a frequency well + + + align:start position:0% +and then finally at a frequency well +beyond crossover we get the filtering + + align:start position:0% +beyond crossover we get the filtering + + + align:start position:0% +beyond crossover we get the filtering +action of the small capacitor and + + align:start position:0% +action of the small capacitor and + + + align:start position:0% +action of the small capacitor and +presumably we choose the value of that + + align:start position:0% +presumably we choose the value of that + + + align:start position:0% +presumably we choose the value of that +capacitor so that it provides adequate + + align:start position:0% +capacitor so that it provides adequate + + + align:start position:0% +capacitor so that it provides adequate +filtering to the residual Ripple out of + + align:start position:0% +filtering to the residual Ripple out of + + + align:start position:0% +filtering to the residual Ripple out of +the phase + + align:start position:0% +the phase + + + align:start position:0% +the phase +detector uh this is the way we've + + align:start position:0% +detector uh this is the way we've + + + align:start position:0% +detector uh this is the way we've +arranged a demonstration system using + + align:start position:0% +arranged a demonstration system using + + + align:start position:0% +arranged a demonstration system using +the + + align:start position:0% +the + + + align:start position:0% +the +565 and in fact what we're able to do in + + align:start position:0% +565 and in fact what we're able to do in + + + align:start position:0% +565 and in fact what we're able to do in +the demonstration system is change this + + align:start position:0% +the demonstration system is change this + + + align:start position:0% +the demonstration system is change this +resistor uh the net effect of doing that + + align:start position:0% +resistor uh the net effect of doing that + + + align:start position:0% +resistor uh the net effect of doing that +uh is principally to change the location + + align:start position:0% +uh is principally to change the location + + + align:start position:0% +uh is principally to change the location +of this zero so we can get a family of + + align:start position:0% +of this zero so we can get a family of + + + align:start position:0% +of this zero so we can get a family of +responses from our phase lock loop or a + + align:start position:0% +responses from our phase lock loop or a + + + align:start position:0% +responses from our phase lock loop or a +family of loop Transmissions + + align:start position:0% +family of loop Transmissions + + + align:start position:0% +family of loop Transmissions +that correspond to either crossing over + + align:start position:0% +that correspond to either crossing over + + + align:start position:0% +that correspond to either crossing over +with a 1 over s s kind of a rollof where + + align:start position:0% +with a 1 over s s kind of a rollof where + + + align:start position:0% +with a 1 over s s kind of a rollof where +we pushed out the zero to two to higher + + align:start position:0% +we pushed out the zero to two to higher + + + align:start position:0% +we pushed out the zero to two to higher +frequencies or we can cross over with a + + align:start position:0% +frequencies or we can cross over with a + + + align:start position:0% +frequencies or we can cross over with a +1 overs kind of of roll off that + + align:start position:0% +1 overs kind of of roll off that + + + align:start position:0% +1 overs kind of of roll off that +presumably should give us considerably + + align:start position:0% +presumably should give us considerably + + + align:start position:0% +presumably should give us considerably +better + + align:start position:0% +better + + + align:start position:0% +better +stability uh here we have the system + + align:start position:0% +stability uh here we have the system + + + align:start position:0% +stability uh here we have the system +we're talking about buried in here is + + align:start position:0% +we're talking about buried in here is + + + align:start position:0% +we're talking about buried in here is +the 565 type uh phase lock loop chip and + + align:start position:0% +the 565 type uh phase lock loop chip and + + + align:start position:0% +the 565 type uh phase lock loop chip and +some of the peripheral components that + + align:start position:0% +some of the peripheral components that + + + align:start position:0% +some of the peripheral components that +we need this is the potentiometer that's + + align:start position:0% +we need this is the potentiometer that's + + + align:start position:0% +we need this is the potentiometer that's +mechanizing the resistor function that I + + align:start position:0% +mechanizing the resistor function that I + + + align:start position:0% +mechanizing the resistor function that I +had mentioned we're driving the whole + + align:start position:0% +had mentioned we're driving the whole + + + align:start position:0% +had mentioned we're driving the whole +thing with an external voltage + + align:start position:0% +thing with an external voltage + + + align:start position:0% +thing with an external voltage +controlled oscillator so this box is a a + + align:start position:0% +controlled oscillator so this box is a a + + + align:start position:0% +controlled oscillator so this box is a a +function generator which can in fact be + + align:start position:0% +function generator which can in fact be + + + align:start position:0% +function generator which can in fact be +voltage controlled and we can use that + + align:start position:0% +voltage controlled and we can use that + + + align:start position:0% +voltage controlled and we can use that +function to put in a changes in in input + + align:start position:0% +function to put in a changes in in input + + + align:start position:0% +function to put in a changes in in input +frequency and here we have a a signal + + align:start position:0% +frequency and here we have a a signal + + + align:start position:0% +frequency and here we have a a signal +generated again in our little test + + align:start position:0% +generated again in our little test + + + align:start position:0% +generated again in our little test +circuit that we can use to modulate the + + align:start position:0% +circuit that we can use to modulate the + + + align:start position:0% +circuit that we can use to modulate the +frequency modulate the generator that's + + align:start position:0% +frequency modulate the generator that's + + + align:start position:0% +frequency modulate the generator that's +providing our Command + + align:start position:0% +providing our Command + + + align:start position:0% +providing our Command +signal uh the amplitude of that command + + align:start position:0% +signal uh the amplitude of that command + + + align:start position:0% +signal uh the amplitude of that command +the amplitude of the signal driving our + + align:start position:0% +the amplitude of the signal driving our + + + align:start position:0% +the amplitude of the signal driving our +our the frequency modulation input on + + align:start position:0% +our the frequency modulation input on + + + align:start position:0% +our the frequency modulation input on +our input generator uh can be controlled + + align:start position:0% +our input generator uh can be controlled + + + align:start position:0% +our input generator uh can be controlled +with this + + align:start position:0% +with this + + + align:start position:0% +with this +potentiometer and what we see now is the + + align:start position:0% +potentiometer and what we see now is the + + + align:start position:0% +potentiometer and what we see now is the +commanded signal applied actually to the + + align:start position:0% +commanded signal applied actually to the + + + align:start position:0% +commanded signal applied actually to the +voltage controlled oscillator the bottom + + align:start position:0% +voltage controlled oscillator the bottom + + + align:start position:0% +voltage controlled oscillator the bottom +trace on the oscilloscope the square + + align:start position:0% +trace on the oscilloscope the square + + + align:start position:0% +trace on the oscilloscope the square +wave is is the signal that we're + + align:start position:0% +wave is is the signal that we're + + + align:start position:0% +wave is is the signal that we're +applying to the FM input on our signal + + align:start position:0% +applying to the FM input on our signal + + + align:start position:0% +applying to the FM input on our signal +generator so when we apply a positive + + align:start position:0% +generator so when we apply a positive + + + align:start position:0% +generator so when we apply a positive +signal the frequency speeds up a bit + + align:start position:0% +signal the frequency speeds up a bit + + + align:start position:0% +signal the frequency speeds up a bit +when we apply a negative signal the + + align:start position:0% +when we apply a negative signal the + + + align:start position:0% +when we apply a negative signal the +lower level it slows down a bit the top + + align:start position:0% +lower level it slows down a bit the top + + + align:start position:0% +lower level it slows down a bit the top +Trace uh is the really indicating the + + align:start position:0% +Trace uh is the really indicating the + + + align:start position:0% +Trace uh is the really indicating the +response of our Loop and it's there's a + + align:start position:0% +response of our Loop and it's there's a + + + align:start position:0% +response of our Loop and it's there's a +particularly convenient place to look in + + align:start position:0% +particularly convenient place to look in + + + align:start position:0% +particularly convenient place to look in +in one of these sorts of Loops that's + + align:start position:0% +in one of these sorts of Loops that's + + + align:start position:0% +in one of these sorts of Loops that's +the input to the voltage controlled + + align:start position:0% +the input to the voltage controlled + + + align:start position:0% +the input to the voltage controlled +oscillator so the the signal on the top + + align:start position:0% +oscillator so the the signal on the top + + + align:start position:0% +oscillator so the the signal on the top +trace of the oscilloscope is the signal + + align:start position:0% +trace of the oscilloscope is the signal + + + align:start position:0% +trace of the oscilloscope is the signal +into the voltage controlled oscillator + + align:start position:0% +into the voltage controlled oscillator + + + align:start position:0% +into the voltage controlled oscillator +to the extent that the vco is dynamic + + align:start position:0% +to the extent that the vco is dynamic + + + align:start position:0% +to the extent that the vco is dynamic +less that's a direct measure of the + + align:start position:0% +less that's a direct measure of the + + + align:start position:0% +less that's a direct measure of the +output frequency of the system and so + + align:start position:0% +output frequency of the system and so + + + align:start position:0% +output frequency of the system and so +rather than trying to do something some + + align:start position:0% +rather than trying to do something some + + + align:start position:0% +rather than trying to do something some +sort of discriminator that operates on + + align:start position:0% +sort of discriminator that operates on + + + align:start position:0% +sort of discriminator that operates on +the output frequency we're able to use + + align:start position:0% +the output frequency we're able to use + + + align:start position:0% +the output frequency we're able to use +the input signal to the voltage + + align:start position:0% +the input signal to the voltage + + + align:start position:0% +the input signal to the voltage +controlled oscillator as that as that + + align:start position:0% +controlled oscillator as that as that + + + align:start position:0% +controlled oscillator as that as that +frequency as that signal um now we I'll + + align:start position:0% +frequency as that signal um now we I'll + + + align:start position:0% +frequency as that signal um now we I'll +change the resistor that I indicated in + + align:start position:0% +change the resistor that I indicated in + + + align:start position:0% +change the resistor that I indicated in +the next Network and as we go to smaller + + align:start position:0% +the next Network and as we go to smaller + + + align:start position:0% +the next Network and as we go to smaller +values of resistor why we should have + + align:start position:0% +values of resistor why we should have + + + align:start position:0% +values of resistor why we should have +relatively less stability in the system + + align:start position:0% +relatively less stability in the system + + + align:start position:0% +relatively less stability in the system +so let me work on this now that's this + + align:start position:0% +so let me work on this now that's this + + + align:start position:0% +so let me work on this now that's this +is going toward uh larger values of that + + align:start position:0% +is going toward uh larger values of that + + + align:start position:0% +is going toward uh larger values of that +resistor and we get very close to first + + align:start position:0% +resistor and we get very close to first + + + align:start position:0% +resistor and we get very close to first +order kinds of + + align:start position:0% +order kinds of + + + align:start position:0% +order kinds of +responses uh as we as we make uh this + + align:start position:0% +responses uh as we as we make uh this + + + align:start position:0% +responses uh as we as we make uh this +resistor larger we get as I say very + + align:start position:0% +resistor larger we get as I say very + + + align:start position:0% +resistor larger we get as I say very +close to first order kinds of response + + align:start position:0% +close to first order kinds of response + + + align:start position:0% +close to first order kinds of response +we cross over with very nearly a 1/s + + align:start position:0% +we cross over with very nearly a 1/s + + + align:start position:0% +we cross over with very nearly a 1/s +kind of of slope we've moved + + align:start position:0% +kind of of slope we've moved + + + align:start position:0% +kind of of slope we've moved +this zero back toward lower + + align:start position:0% +this zero back toward lower + + + align:start position:0% +this zero back toward lower +frequencies uh if I now make the + + align:start position:0% +frequencies uh if I now make the + + + align:start position:0% +frequencies uh if I now make the +resistor smaller we cross over or we can + + align:start position:0% +resistor smaller we cross over or we can + + + align:start position:0% +resistor smaller we cross over or we can +force cross over in a one over + + align:start position:0% +force cross over in a one over + + + align:start position:0% +force cross over in a one over +uh s + + align:start position:0% +uh s + + + align:start position:0% +uh s +squ kind of a region + + align:start position:0% + + + + align:start position:0% + +and as we do that we get progressively + + align:start position:0% +and as we do that we get progressively + + + align:start position:0% +and as we do that we get progressively +less + + align:start position:0% +less + + + align:start position:0% +less +stable responses so here's the case + + align:start position:0% +stable responses so here's the case + + + align:start position:0% +stable responses so here's the case +where we have the a very small value for + + align:start position:0% +where we have the a very small value for + + + align:start position:0% +where we have the a very small value for +the resistor we notice a very highly + + align:start position:0% +the resistor we notice a very highly + + + align:start position:0% +the resistor we notice a very highly +oscillatory response probably + + align:start position:0% +oscillatory response probably + + + align:start position:0% +oscillatory response probably +corresponding to several degrees of + + align:start position:0% +corresponding to several degrees of + + + align:start position:0% +corresponding to several degrees of +phase + + align:start position:0% +phase + + + align:start position:0% +phase +margin we can again improve the behavior + + align:start position:0% +margin we can again improve the behavior + + + align:start position:0% +margin we can again improve the behavior +of the system improve the + + align:start position:0% +of the system improve the + + + align:start position:0% +of the system improve the +damping by going to a larger value of + + align:start position:0% +damping by going to a larger value of + + + align:start position:0% +damping by going to a larger value of +resistor but the speed of the system + + align:start position:0% +resistor but the speed of the system + + + align:start position:0% +resistor but the speed of the system +slows down a little little + + align:start position:0% +slows down a little little + + + align:start position:0% +slows down a little little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +uh so we can get that we can observe + + align:start position:0% +uh so we can get that we can observe + + + align:start position:0% +uh so we can get that we can observe +that sort of Behavior Uh in the output + + align:start position:0% +that sort of Behavior Uh in the output + + + align:start position:0% +that sort of Behavior Uh in the output +frequency the output frequency is of + + align:start position:0% +frequency the output frequency is of + + + align:start position:0% +frequency the output frequency is of +course being modulated being frequency + + align:start position:0% +course being modulated being frequency + + + align:start position:0% +course being modulated being frequency +modulated proportional to the signal + + align:start position:0% +modulated proportional to the signal + + + align:start position:0% +modulated proportional to the signal +shown we notice on on the signal + + align:start position:0% +shown we notice on on the signal + + + align:start position:0% +shown we notice on on the signal +relatively small we don't really see + + align:start position:0% +relatively small we don't really see + + + align:start position:0% +relatively small we don't really see +much ripple at all from the phase + + align:start position:0% +much ripple at all from the phase + + + align:start position:0% +much ripple at all from the phase +detector this particular system uh is + + align:start position:0% +detector this particular system uh is + + + align:start position:0% +detector this particular system uh is +working at a carrier frequency of about + + align:start position:0% +working at a carrier frequency of about + + + align:start position:0% +working at a carrier frequency of about +30 khz and we cross over at a fraction + + align:start position:0% +30 khz and we cross over at a fraction + + + align:start position:0% +30 khz and we cross over at a fraction +of a kilohertz somewhere on the order of + + align:start position:0% +of a kilohertz somewhere on the order of + + + align:start position:0% +of a kilohertz somewhere on the order of +700 Herz so we're crossing over at a + + align:start position:0% +700 Herz so we're crossing over at a + + + align:start position:0% +700 Herz so we're crossing over at a +small fraction of the carrier frequency + + align:start position:0% +small fraction of the carrier frequency + + + align:start position:0% +small fraction of the carrier frequency +we're able to a very good job of + + align:start position:0% +we're able to a very good job of + + + align:start position:0% +we're able to a very good job of +filtering the signal out of the phase + + align:start position:0% +filtering the signal out of the phase + + + align:start position:0% +filtering the signal out of the phase +detector with that sort of spread + + align:start position:0% +detector with that sort of spread + + + align:start position:0% +detector with that sort of spread +between crossover frequency and the + + align:start position:0% +between crossover frequency and the + + + align:start position:0% +between crossover frequency and the +frequency of + + align:start position:0% +frequency of + + + align:start position:0% +frequency of +operation I had mentioned earlier that + + align:start position:0% +operation I had mentioned earlier that + + + align:start position:0% +operation I had mentioned earlier that +there are linearity problems associated + + align:start position:0% +there are linearity problems associated + + + align:start position:0% +there are linearity problems associated +with phase lock + + align:start position:0% +with phase lock + + + align:start position:0% +with phase lock +loops and uh we can see a little bit of + + align:start position:0% +loops and uh we can see a little bit of + + + align:start position:0% +loops and uh we can see a little bit of +that let's let's look at at the response + + align:start position:0% +that let's let's look at at the response + + + align:start position:0% +that let's let's look at at the response +of our system and and let's see if we + + align:start position:0% +of our system and and let's see if we + + + align:start position:0% +of our system and and let's see if we +can observe some of those + + align:start position:0% +can observe some of those + + + align:start position:0% +can observe some of those +difficulties one of them uh we can get + + align:start position:0% +difficulties one of them uh we can get + + + align:start position:0% +difficulties one of them uh we can get +uh let's go in there for + + align:start position:0% +uh let's go in there for + + + align:start position:0% +uh let's go in there for +example we notice that that looks almost + + align:start position:0% +example we notice that that looks almost + + + align:start position:0% +example we notice that that looks almost +like a second order response but if we + + align:start position:0% +like a second order response but if we + + + align:start position:0% +like a second order response but if we +look at it very very carefully we find + + align:start position:0% +look at it very very carefully we find + + + align:start position:0% +look at it very very carefully we find +out that that really isn't the response + + align:start position:0% +out that that really isn't the response + + + align:start position:0% +out that that really isn't the response +of a linear second order system the uh + + align:start position:0% +of a linear second order system the uh + + + align:start position:0% +of a linear second order system the uh +for example the second positive + + align:start position:0% +for example the second positive + + + align:start position:0% +for example the second positive +overshoot is Big relative to the first + + align:start position:0% +overshoot is Big relative to the first + + + align:start position:0% +overshoot is Big relative to the first +negative uh undershoot if you will it's + + align:start position:0% +negative uh undershoot if you will it's + + + align:start position:0% +negative uh undershoot if you will it's +not the kind of a of a transient + + align:start position:0% +not the kind of a of a transient + + + align:start position:0% +not the kind of a of a transient +response that corresponds to a true + + align:start position:0% +response that corresponds to a true + + + align:start position:0% +response that corresponds to a true +linear system uh the response also sort + + align:start position:0% +linear system uh the response also sort + + + align:start position:0% +linear system uh the response also sort +of damps out a little bit too quickly + + align:start position:0% +of damps out a little bit too quickly + + + align:start position:0% +of damps out a little bit too quickly +compared to the size of the first + + align:start position:0% +compared to the size of the first + + + align:start position:0% +compared to the size of the first +overshoot uh so there's something just a + + align:start position:0% +overshoot uh so there's something just a + + + align:start position:0% +overshoot uh so there's something just a +little bit funny about the response of + + align:start position:0% +little bit funny about the response of + + + align:start position:0% +little bit funny about the response of +the system and that reflects the + + align:start position:0% +the system and that reflects the + + + align:start position:0% +the system and that reflects the +nonlinearities associated with the phase + + align:start position:0% +nonlinearities associated with the phase + + + align:start position:0% +nonlinearities associated with the phase +detection process and and uh the uh uh + + align:start position:0% +detection process and and uh the uh uh + + + align:start position:0% +detection process and and uh the uh uh +difficulties of of maintaining lock for + + align:start position:0% +difficulties of of maintaining lock for + + + align:start position:0% +difficulties of of maintaining lock for +large ranges of signal we can make that + + align:start position:0% +large ranges of signal we can make that + + + align:start position:0% +large ranges of signal we can make that +problem worse by increasing the amount + + align:start position:0% +problem worse by increasing the amount + + + align:start position:0% +problem worse by increasing the amount +by which we change the command input and + + align:start position:0% +by which we change the command input and + + + align:start position:0% +by which we change the command input and +if I do that with this potentiometer + + align:start position:0% +if I do that with this potentiometer + + + align:start position:0% +if I do that with this potentiometer +which simply adjusts the amplitude of + + align:start position:0% +which simply adjusts the amplitude of + + + align:start position:0% +which simply adjusts the amplitude of +the signal applied to our external + + align:start position:0% +the signal applied to our external + + + align:start position:0% +the signal applied to our external +generator well we notice we can get + + align:start position:0% +generator well we notice we can get + + + align:start position:0% +generator well we notice we can get +quite bizarre modes of behavior in the + + align:start position:0% +quite bizarre modes of behavior in the + + + align:start position:0% +quite bizarre modes of behavior in the +phase lock blue uh uh really very poor + + align:start position:0% +phase lock blue uh uh really very poor + + + align:start position:0% +phase lock blue uh uh really very poor +performance and what we're really what's + + align:start position:0% +performance and what we're really what's + + + align:start position:0% +performance and what we're really what's +really happening here is commanding such + + align:start position:0% +really happening here is commanding such + + + align:start position:0% +really happening here is commanding such +a large frequency Excursion at the input + + align:start position:0% +a large frequency Excursion at the input + + + align:start position:0% +a large frequency Excursion at the input +that the loop can't really keep up we + + align:start position:0% +that the loop can't really keep up we + + + align:start position:0% +that the loop can't really keep up we +skip a couple of Cycles the phase + + align:start position:0% +skip a couple of Cycles the phase + + + align:start position:0% +skip a couple of Cycles the phase +detector is cyclical as I mentioned we + + align:start position:0% +detector is cyclical as I mentioned we + + + align:start position:0% +detector is cyclical as I mentioned we +jump a few Cycles uh the recovery from + + align:start position:0% +jump a few Cycles uh the recovery from + + + align:start position:0% +jump a few Cycles uh the recovery from +that is quite tortured uh if we go back + + align:start position:0% +that is quite tortured uh if we go back + + + align:start position:0% +that is quite tortured uh if we go back +to a more modest input uh we get + + align:start position:0% +to a more modest input uh we get + + + align:start position:0% +to a more modest input uh we get +considerably better looking kinds of + + align:start position:0% +considerably better looking kinds of + + + align:start position:0% +considerably better looking kinds of +responses although we can see a gradual + + align:start position:0% +responses although we can see a gradual + + + align:start position:0% +responses although we can see a gradual +change in the nature uh there's a + + align:start position:0% +change in the nature uh there's a + + + align:start position:0% +change in the nature uh there's a +response that looks somewhat nonlinear + + align:start position:0% +response that looks somewhat nonlinear + + + align:start position:0% +response that looks somewhat nonlinear +again the sort of third positive + + align:start position:0% +again the sort of third positive + + + align:start position:0% +again the sort of third positive +overshoot is really too small relative + + align:start position:0% +overshoot is really too small relative + + + align:start position:0% +overshoot is really too small relative +to the others um and there again is the + + align:start position:0% +to the others um and there again is the + + + align:start position:0% +to the others um and there again is the +very bad response when we completely + + align:start position:0% +very bad response when we completely + + + align:start position:0% +very bad response when we completely +overdrive the system there's a rather + + align:start position:0% +overdrive the system there's a rather + + + align:start position:0% +overdrive the system there's a rather +complex relationship between uh uh that + + align:start position:0% +complex relationship between uh uh that + + + align:start position:0% +complex relationship between uh uh that +control and and the amount of damping in + + align:start position:0% +control and and the amount of damping in + + + align:start position:0% +control and and the amount of damping in +the system and so forth uh that all of + + align:start position:0% +the system and so forth uh that all of + + + align:start position:0% +the system and so forth uh that all of +which interact in the large signal + + align:start position:0% +which interact in the large signal + + + align:start position:0% +which interact in the large signal +performance of the + + align:start position:0% + + + + align:start position:0% + +system much of the difficulty in the the + + align:start position:0% +system much of the difficulty in the the + + + align:start position:0% +system much of the difficulty in the the +large signal behavior of a phase locked + + align:start position:0% +large signal behavior of a phase locked + + + align:start position:0% +large signal behavior of a phase locked +Loop deals with or has to do really with + + align:start position:0% +Loop deals with or has to do really with + + + align:start position:0% +Loop deals with or has to do really with +the cyclical nature of the phase + + align:start position:0% +the cyclical nature of the phase + + + align:start position:0% +the cyclical nature of the phase +detector the kinds of phase detectors + + align:start position:0% +detector the kinds of phase detectors + + + align:start position:0% +detector the kinds of phase detectors +that I've discussed are ones that repeat + + align:start position:0% +that I've discussed are ones that repeat + + + align:start position:0% +that I've discussed are ones that repeat +every 180 or 360 degrees or whatever + + align:start position:0% +every 180 or 360 degrees or whatever + + + align:start position:0% +every 180 or 360 degrees or whatever +and in some sense one of the one of the + + align:start position:0% +and in some sense one of the one of the + + + align:start position:0% +and in some sense one of the one of the +problems with that sort of a thing is is + + align:start position:0% +problems with that sort of a thing is is + + + align:start position:0% +problems with that sort of a thing is is +consider the behavior when we have a + + align:start position:0% +consider the behavior when we have a + + + align:start position:0% +consider the behavior when we have a +significant difference between the + + align:start position:0% +significant difference between the + + + align:start position:0% +significant difference between the +frequencies that we're applying to the + + align:start position:0% +frequencies that we're applying to the + + + align:start position:0% +frequencies that we're applying to the +phase locked Loop and the frequency that + + align:start position:0% +phase locked Loop and the frequency that + + + align:start position:0% +phase locked Loop and the frequency that +the circuit is responding at if there's + + align:start position:0% +the circuit is responding at if there's + + + align:start position:0% +the circuit is responding at if there's +a major frequency difference the output + + align:start position:0% +a major frequency difference the output + + + align:start position:0% +a major frequency difference the output +of the phase detector will be a a signal + + align:start position:0% +of the phase detector will be a a signal + + + align:start position:0% +of the phase detector will be a a signal +at basically the difference frequency + + align:start position:0% +at basically the difference frequency + + + align:start position:0% +at basically the difference frequency +between the two uh it effectively has + + align:start position:0% +between the two uh it effectively has + + + align:start position:0% +between the two uh it effectively has +zero average value uh from that kind of + + align:start position:0% +zero average value uh from that kind of + + + align:start position:0% +zero average value uh from that kind of +a phase detector and so when we're in + + align:start position:0% +a phase detector and so when we're in + + + align:start position:0% +a phase detector and so when we're in +that situation the phase lock loop has a + + align:start position:0% +that situation the phase lock loop has a + + + align:start position:0% +that situation the phase lock loop has a +very difficult time reacquiring lock + + align:start position:0% +very difficult time reacquiring lock + + + align:start position:0% +very difficult time reacquiring lock +because it doesn't get a clear + + align:start position:0% +because it doesn't get a clear + + + align:start position:0% +because it doesn't get a clear +indication of the error it doesn't get a + + align:start position:0% +indication of the error it doesn't get a + + + align:start position:0% +indication of the error it doesn't get a +clear indication of of which frequency + + align:start position:0% +clear indication of of which frequency + + + align:start position:0% +clear indication of of which frequency +applied to the phase detector is the + + align:start position:0% +applied to the phase detector is the + + + align:start position:0% +applied to the phase detector is the +higher of the two and so it has a great + + align:start position:0% +higher of the two and so it has a great + + + align:start position:0% +higher of the two and so it has a great +deal of difficulty recovering the + + align:start position:0% +deal of difficulty recovering the + + + align:start position:0% +deal of difficulty recovering the +Dynamics of those sorts of large signal + + align:start position:0% +Dynamics of those sorts of large signal + + + align:start position:0% +Dynamics of those sorts of large signal +uh behavior in in phase lock Loops uh + + align:start position:0% +uh behavior in in phase lock Loops uh + + + align:start position:0% +uh behavior in in phase lock Loops uh +are are very complicated and and the a + + align:start position:0% +are are very complicated and and the a + + + align:start position:0% +are are very complicated and and the a +lot of the difficulty of design in a + + align:start position:0% +lot of the difficulty of design in a + + + align:start position:0% +lot of the difficulty of design in a +phase lock loop comes from trying to + + align:start position:0% +phase lock loop comes from trying to + + + align:start position:0% +phase lock loop comes from trying to +build a loop that will have good + + align:start position:0% +build a loop that will have good + + + align:start position:0% +build a loop that will have good +acquisition time when it it's fairly + + align:start position:0% +acquisition time when it it's fairly + + + align:start position:0% +acquisition time when it it's fairly +easy to get to get a loop that's well + + align:start position:0% +easy to get to get a loop that's well + + + align:start position:0% +easy to get to get a loop that's well +behaved for small signals for + + align:start position:0% +behaved for small signals for + + + align:start position:0% +behaved for small signals for +sufficiently small signals but if you'd + + align:start position:0% +sufficiently small signals but if you'd + + + align:start position:0% +sufficiently small signals but if you'd +like to have a large or a very fast + + align:start position:0% +like to have a large or a very fast + + + align:start position:0% +like to have a large or a very fast +settling time for a large frequency + + align:start position:0% +settling time for a large frequency + + + align:start position:0% +settling time for a large frequency +error well we find that's a much more + + align:start position:0% +error well we find that's a much more + + + align:start position:0% +error well we find that's a much more +difficult thing to do that problem + + align:start position:0% +difficult thing to do that problem + + + align:start position:0% +difficult thing to do that problem +exists for example often times in the + + align:start position:0% +exists for example often times in the + + + align:start position:0% +exists for example often times in the +frequency synthesizer you make a change + + align:start position:0% +frequency synthesizer you make a change + + + align:start position:0% +frequency synthesizer you make a change +actually a step change in N change the + + align:start position:0% +actually a step change in N change the + + + align:start position:0% +actually a step change in N change the +value of n that disturbs the loop uh but + + align:start position:0% +value of n that disturbs the loop uh but + + + align:start position:0% +value of n that disturbs the loop uh but +in many cases you'd like to have very + + align:start position:0% +in many cases you'd like to have very + + + align:start position:0% +in many cases you'd like to have very +rapid settling to a new frequency and to + + align:start position:0% +rapid settling to a new frequency and to + + + align:start position:0% +rapid settling to a new frequency and to +the new frequency at the output that + + align:start position:0% +the new frequency at the output that + + + align:start position:0% +the new frequency at the output that +kind of of settling rapid settling is is + + align:start position:0% +kind of of settling rapid settling is is + + + align:start position:0% +kind of of settling rapid settling is is +a very challenging sort of design + + align:start position:0% +a very challenging sort of design + + + align:start position:0% +a very challenging sort of design +problem + + align:start position:0% +problem + + + align:start position:0% +problem +part of of the secret is to use a better + + align:start position:0% +part of of the secret is to use a better + + + align:start position:0% +part of of the secret is to use a better +phase detector than the ones we've + + align:start position:0% +phase detector than the ones we've + + + align:start position:0% +phase detector than the ones we've +talked about + + align:start position:0% +talked about + + + align:start position:0% +talked about +here the uh uh for example there are + + align:start position:0% +here the uh uh for example there are + + + align:start position:0% +here the uh uh for example there are +more complicated more sophisticated uh + + align:start position:0% +more complicated more sophisticated uh + + + align:start position:0% +more complicated more sophisticated uh +phase detectors most of them digital in + + align:start position:0% +phase detectors most of them digital in + + + align:start position:0% +phase detectors most of them digital in +nature uh there are several that are + + align:start position:0% +nature uh there are several that are + + + align:start position:0% +nature uh there are several that are +available in integrated circuit form + + align:start position:0% +available in integrated circuit form + + + align:start position:0% +available in integrated circuit form +although we chose not to use them in + + align:start position:0% +although we chose not to use them in + + + align:start position:0% +although we chose not to use them in +this particular system there are several + + align:start position:0% +this particular system there are several + + + align:start position:0% +this particular system there are several +uh which keep track of which frequency + + align:start position:0% +uh which keep track of which frequency + + + align:start position:0% +uh which keep track of which frequency +is higher they are ones that work in in + + align:start position:0% +is higher they are ones that work in in + + + align:start position:0% +is higher they are ones that work in in +basically the mode we've described when + + align:start position:0% +basically the mode we've described when + + + align:start position:0% +basically the mode we've described when +the two frequencies applied to them are + + align:start position:0% +the two frequencies applied to them are + + + align:start position:0% +the two frequencies applied to them are +identical but when the frequencies are + + align:start position:0% +identical but when the frequencies are + + + align:start position:0% +identical but when the frequencies are +different such that you've slipped by a + + align:start position:0% +different such that you've slipped by a + + + align:start position:0% +different such that you've slipped by a +cycle between the one between the two + + align:start position:0% +cycle between the one between the two + + + align:start position:0% +cycle between the one between the two +inputs so that they've slipped relative + + align:start position:0% +inputs so that they've slipped relative + + + align:start position:0% +inputs so that they've slipped relative +to to each other by a cycle why then the + + align:start position:0% +to to each other by a cycle why then the + + + align:start position:0% +to to each other by a cycle why then the +phase detector hangs up and consistently + + align:start position:0% +phase detector hangs up and consistently + + + align:start position:0% +phase detector hangs up and consistently +gives you either a high output or a low + + align:start position:0% +gives you either a high output or a low + + + align:start position:0% +gives you either a high output or a low +output and that difference indicates + + align:start position:0% +output and that difference indicates + + + align:start position:0% +output and that difference indicates +which direction you should change the + + align:start position:0% +which direction you should change the + + + align:start position:0% +which direction you should change the +output frequency to get into + + align:start position:0% +output frequency to get into + + + align:start position:0% +output frequency to get into +correspondence with the command + + align:start position:0% +correspondence with the command + + + align:start position:0% +correspondence with the command +frequency the uh another possibility for + + align:start position:0% +frequency the uh another possibility for + + + align:start position:0% +frequency the uh another possibility for +a phase detector that has again a wide + + align:start position:0% +a phase detector that has again a wide + + + align:start position:0% +a phase detector that has again a wide +dynamic range uh if our signals are + + align:start position:0% +dynamic range uh if our signals are + + + align:start position:0% +dynamic range uh if our signals are +digital in nature is to Simply use a an + + align:start position:0% +digital in nature is to Simply use a an + + + align:start position:0% +digital in nature is to Simply use a an +up down counter as the the phase + + align:start position:0% +up down counter as the the phase + + + align:start position:0% +up down counter as the the phase +detecting element we'll see an example + + align:start position:0% +detecting element we'll see an example + + + align:start position:0% +detecting element we'll see an example +of that actually in the in the next + + align:start position:0% +of that actually in the in the next + + + align:start position:0% +of that actually in the in the next +lecture where I build a particular kind + + align:start position:0% +lecture where I build a particular kind + + + align:start position:0% +lecture where I build a particular kind +of a phase locked Loop and I use an up + + align:start position:0% +of a phase locked Loop and I use an up + + + align:start position:0% +of a phase locked Loop and I use an up +down counter as the phase detector + + align:start position:0% +down counter as the phase detector + + + align:start position:0% +down counter as the phase detector +uh again one might Envision such a loop + + align:start position:0% +uh again one might Envision such a loop + + + align:start position:0% +uh again one might Envision such a loop +operating when the two frequencies + + align:start position:0% +operating when the two frequencies + + + align:start position:0% +operating when the two frequencies +applied to it are identical it works as + + align:start position:0% +applied to it are identical it works as + + + align:start position:0% +applied to it are identical it works as +we've described we get a a signal uh + + align:start position:0% +we've described we get a a signal uh + + + align:start position:0% +we've described we get a a signal uh +from it which basically is averaged in + + align:start position:0% +from it which basically is averaged in + + + align:start position:0% +from it which basically is averaged in +order to get uh a phase relative phase + + align:start position:0% +order to get uh a phase relative phase + + + align:start position:0% +order to get uh a phase relative phase +error when the two signals are are + + align:start position:0% +error when the two signals are are + + + align:start position:0% +error when the two signals are are +nearly identical the U or when the two + + align:start position:0% +nearly identical the U or when the two + + + align:start position:0% +nearly identical the U or when the two +frequencies are identical but there's a + + align:start position:0% +frequencies are identical but there's a + + + align:start position:0% +frequencies are identical but there's a +relative phase difference between them + + align:start position:0% +relative phase difference between them + + + align:start position:0% +relative phase difference between them +we have some sort of a digital signal + + align:start position:0% +we have some sort of a digital signal + + + align:start position:0% +we have some sort of a digital signal +that's averaged + + align:start position:0% +that's averaged + + + align:start position:0% +that's averaged +the when the uh uh frequencies now + + align:start position:0% +the when the uh uh frequencies now + + + align:start position:0% +the when the uh uh frequencies now +differ why the up down counter + + align:start position:0% +differ why the up down counter + + + align:start position:0% +differ why the up down counter +accumulates counts either up counts or + + align:start position:0% +accumulates counts either up counts or + + + align:start position:0% +accumulates counts either up counts or +down counts depending on whether the + + align:start position:0% +down counts depending on whether the + + + align:start position:0% +down counts depending on whether the +command frequency or the response of the + + align:start position:0% +command frequency or the response of the + + + align:start position:0% +command frequency or the response of the +circuit uh is greater uh the state of + + align:start position:0% +circuit uh is greater uh the state of + + + align:start position:0% +circuit uh is greater uh the state of +that counter then is a direct measure of + + align:start position:0% +that counter then is a direct measure of + + + align:start position:0% +that counter then is a direct measure of +the total number of cycles that we've + + align:start position:0% +the total number of cycles that we've + + + align:start position:0% +the total number of cycles that we've +slipped between the two we can then + + align:start position:0% +slipped between the two we can then + + + align:start position:0% +slipped between the two we can then +conceptually D to a convert the output + + align:start position:0% +conceptually D to a convert the output + + + align:start position:0% +conceptually D to a convert the output +of the counter get an analog signal + + align:start position:0% +of the counter get an analog signal + + + align:start position:0% +of the counter get an analog signal +that's a measure of the total number of + + align:start position:0% +that's a measure of the total number of + + + align:start position:0% +that's a measure of the total number of +Cycles the total phase error we now + + align:start position:0% +Cycles the total phase error we now + + + align:start position:0% +Cycles the total phase error we now +don't have this cyclical nature where + + align:start position:0% +don't have this cyclical nature where + + + align:start position:0% +don't have this cyclical nature where +things cycle every 180 degrees of + + align:start position:0% +things cycle every 180 degrees of + + + align:start position:0% +things cycle every 180 degrees of +relative phase error every 360 Dees and + + align:start position:0% +relative phase error every 360 Dees and + + + align:start position:0% +relative phase error every 360 Dees and +we're able to keep a complete measure of + + align:start position:0% +we're able to keep a complete measure of + + + align:start position:0% +we're able to keep a complete measure of +the total phase error of the system the + + align:start position:0% +the total phase error of the system the + + + align:start position:0% +the total phase error of the system the +total accumulated phase error and uh in + + align:start position:0% +total accumulated phase error and uh in + + + align:start position:0% +total accumulated phase error and uh in +that way we're able to build a system + + align:start position:0% +that way we're able to build a system + + + align:start position:0% +that way we're able to build a system +that's linear for very large phase + + align:start position:0% +that's linear for very large phase + + + align:start position:0% +that's linear for very large phase +differences many cycles of phase error + + align:start position:0% +differences many cycles of phase error + + + align:start position:0% +differences many cycles of phase error +depending on the length of the up down + + align:start position:0% +depending on the length of the up down + + + align:start position:0% +depending on the length of the up down +counter and that will enable us to build + + align:start position:0% +counter and that will enable us to build + + + align:start position:0% +counter and that will enable us to build +a a system that that remain that that + + align:start position:0% +a a system that that remain that that + + + align:start position:0% +a a system that that remain that that +exhibits linear responses for very large + + align:start position:0% +exhibits linear responses for very large + + + align:start position:0% +exhibits linear responses for very large +changes in the commanded frequency and + + align:start position:0% +changes in the commanded frequency and + + + align:start position:0% +changes in the commanded frequency and +in that way people are able to build + + align:start position:0% +in that way people are able to build + + + align:start position:0% +in that way people are able to build +phase locked Loops that's one technique + + align:start position:0% +phase locked Loops that's one technique + + + align:start position:0% +phase locked Loops that's one technique +at least used to build phase locked + + align:start position:0% +at least used to build phase locked + + + align:start position:0% +at least used to build phase locked +Loops that have wide dynamic range we + + align:start position:0% +Loops that have wide dynamic range we + + + align:start position:0% +Loops that have wide dynamic range we +have one more demo uh we can use this + + align:start position:0% +have one more demo uh we can use this + + + align:start position:0% +have one more demo uh we can use this +box + + align:start position:0% +box + + + align:start position:0% +box +for uh here what we're looking at is uh + + align:start position:0% +for uh here what we're looking at is uh + + + align:start position:0% +for uh here what we're looking at is uh +again using effectively the same setup + + align:start position:0% +again using effectively the same setup + + + align:start position:0% +again using effectively the same setup +but where we've made a a couple of + + align:start position:0% +but where we've made a a couple of + + + align:start position:0% +but where we've made a a couple of +modific ations to component values so + + align:start position:0% +modific ations to component values so + + + align:start position:0% +modific ations to component values so +that we've increased the dynamic range + + align:start position:0% +that we've increased the dynamic range + + + align:start position:0% +that we've increased the dynamic range +of the circuit the circuit with + + align:start position:0% +of the circuit the circuit with + + + align:start position:0% +of the circuit the circuit with +parameters as we demonstrated it before + + align:start position:0% +parameters as we demonstrated it before + + + align:start position:0% +parameters as we demonstrated it before +had a very small dynamic range a very + + align:start position:0% +had a very small dynamic range a very + + + align:start position:0% +had a very small dynamic range a very +small range of frequencies over which + + align:start position:0% +small range of frequencies over which + + + align:start position:0% +small range of frequencies over which +the loop would work properly here we've + + align:start position:0% +the loop would work properly here we've + + + align:start position:0% +the loop would work properly here we've +modified that a little bit so there's + + align:start position:0% +modified that a little bit so there's + + + align:start position:0% +modified that a little bit so there's +now a few percent possibility for change + + align:start position:0% +now a few percent possibility for change + + + align:start position:0% +now a few percent possibility for change +in + + align:start position:0% +in + + + align:start position:0% +in +frequency and what we're looking at is + + align:start position:0% +frequency and what we're looking at is + + + align:start position:0% +frequency and what we're looking at is +the uh on one hand again the signal uh + + align:start position:0% +the uh on one hand again the signal uh + + + align:start position:0% +the uh on one hand again the signal uh +that's that's applied to the VC o which + + align:start position:0% +that's that's applied to the VC o which + + + align:start position:0% +that's that's applied to the VC o which +is proportional to the command signal + + align:start position:0% +is proportional to the command signal + + + align:start position:0% +is proportional to the command signal +and then the bottom Trace is a signal + + align:start position:0% +and then the bottom Trace is a signal + + + align:start position:0% +and then the bottom Trace is a signal +not the actual operating frequency of + + align:start position:0% +not the actual operating frequency of + + + align:start position:0% +not the actual operating frequency of +the loop but a divided multiple of the + + align:start position:0% +the loop but a divided multiple of the + + + align:start position:0% +the loop but a divided multiple of the +output frequency at which the phase lock + + align:start position:0% +output frequency at which the phase lock + + + align:start position:0% +output frequency at which the phase lock +loop is operating uh so we can see it + + align:start position:0% +loop is operating uh so we can see it + + + align:start position:0% +loop is operating uh so we can see it +conveniently on the same sort of a time + + align:start position:0% +conveniently on the same sort of a time + + + align:start position:0% +conveniently on the same sort of a time +scale as the vco signal and what we can + + align:start position:0% +scale as the vco signal and what we can + + + align:start position:0% +scale as the vco signal and what we can +observe here is the behavior if we + + align:start position:0% +observe here is the behavior if we + + + align:start position:0% +observe here is the behavior if we +increase the amplitude of the drive + + align:start position:0% + + + + align:start position:0% + +signal we again can get into nonlinear + + align:start position:0% +signal we again can get into nonlinear + + + align:start position:0% +signal we again can get into nonlinear +Behavior quite easily but if we don't go + + align:start position:0% +Behavior quite easily but if we don't go + + + align:start position:0% +Behavior quite easily but if we don't go +to that + + align:start position:0% +to that + + + align:start position:0% +to that +point we can see the fing Behavior Uh + + align:start position:0% +point we can see the fing Behavior Uh + + + align:start position:0% +point we can see the fing Behavior Uh +here on + + align:start position:0% +here on + + + align:start position:0% +here on +the first part of the signal if we were + + align:start position:0% +the first part of the signal if we were + + + align:start position:0% +the first part of the signal if we were +direct coupled on the uh signal into the + + align:start position:0% +direct coupled on the uh signal into the + + + align:start position:0% +direct coupled on the uh signal into the +vco we'd see that the first half + + align:start position:0% +vco we'd see that the first half + + + align:start position:0% +vco we'd see that the first half +maintains its DC level and the frequency + + align:start position:0% +maintains its DC level and the frequency + + + align:start position:0% +maintains its DC level and the frequency +on the first part of the cycle does not + + align:start position:0% +on the first part of the cycle does not + + + align:start position:0% +on the first part of the cycle does not +change as we change the amplitude uh + + align:start position:0% +change as we change the amplitude uh + + + align:start position:0% +change as we change the amplitude uh +however the frequency in the second + + align:start position:0% +however the frequency in the second + + + align:start position:0% +however the frequency in the second +portion the uh Following part of the + + align:start position:0% +portion the uh Following part of the + + + align:start position:0% +portion the uh Following part of the +trace we notice changing actually going + + align:start position:0% +trace we notice changing actually going + + + align:start position:0% +trace we notice changing actually going +toward higher frequencies as we increase + + align:start position:0% +toward higher frequencies as we increase + + + align:start position:0% +toward higher frequencies as we increase +the amplitude of the signal applied we + + align:start position:0% +the amplitude of the signal applied we + + + align:start position:0% +the amplitude of the signal applied we +also notice as I say some nonlinear + + align:start position:0% +also notice as I say some nonlinear + + + align:start position:0% +also notice as I say some nonlinear +Behavior there's a little bit of Pop + + align:start position:0% +Behavior there's a little bit of Pop + + + align:start position:0% +Behavior there's a little bit of Pop +there change in mode of behavior in + + align:start position:0% +there change in mode of behavior in + + + align:start position:0% +there change in mode of behavior in +there but as long as we stay down and in + + align:start position:0% +there but as long as we stay down and in + + + align:start position:0% +there but as long as we stay down and in +this range avoid slipping Cycles + + align:start position:0% +this range avoid slipping Cycles + + + align:start position:0% +this range avoid slipping Cycles +basically in the phase detector we get a + + align:start position:0% +basically in the phase detector we get a + + + align:start position:0% +basically in the phase detector we get a +fairly nice indication of the change in + + align:start position:0% +fairly nice indication of the change in + + + align:start position:0% +fairly nice indication of the change in +frequency that occurs from the voltage + + align:start position:0% +frequency that occurs from the voltage + + + align:start position:0% +frequency that occurs from the voltage +controlled + + align:start position:0% + + + + align:start position:0% + +oscillator this concludes our + + align:start position:0% +oscillator this concludes our + + + align:start position:0% +oscillator this concludes our +introduction to phase lock Loops in the + + align:start position:0% +introduction to phase lock Loops in the + + + align:start position:0% +introduction to phase lock Loops in the +next lecture I'd like to show another + + align:start position:0% +next lecture I'd like to show another + + + align:start position:0% +next lecture I'd like to show another +example of a rather interesting + + align:start position:0% +example of a rather interesting + + + align:start position:0% +example of a rather interesting +application of a phase locked Loop and + + align:start position:0% +application of a phase locked Loop and + + + align:start position:0% +application of a phase locked Loop and +we'll see uh how we can use this to + + align:start position:0% +we'll see uh how we can use this to + + + align:start position:0% +we'll see uh how we can use this to +control a mechan mecal system uh here of + + align:start position:0% +control a mechan mecal system uh here of + + + align:start position:0% +control a mechan mecal system uh here of +course we've been looking at a at a + + align:start position:0% +course we've been looking at a at a + + + align:start position:0% +course we've been looking at a at a +purely electronic system but we'll use + + align:start position:0% +purely electronic system but we'll use + + + align:start position:0% +purely electronic system but we'll use +look at a phase lock technique for motor + + align:start position:0% +look at a phase lock technique for motor + + + align:start position:0% +look at a phase lock technique for motor +speed control in the next lecture thank + + align:start position:0% +speed control in the next lecture thank + + + align:start position:0% +speed control in the next lecture thank +you \ No newline at end of file diff --git a/Q47hTa1KvN0.txt b/Q47hTa1KvN0.txt new file mode 100644 index 0000000000000000000000000000000000000000..f588576e41adc3552d4e0c0f254dcebe7ebda4c3 --- /dev/null +++ b/Q47hTa1KvN0.txt @@ -0,0 +1,2491 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +recrystallization + + align:start position:0% + + + + align:start position:0% + +a large percentage of a chemist time in + + align:start position:0% +a large percentage of a chemist time in + + + align:start position:0% +a large percentage of a chemist time in +the laboratory is spent purifying + + align:start position:0% +the laboratory is spent purifying + + + align:start position:0% +the laboratory is spent purifying +chemicals learning to use a variety of + + align:start position:0% +chemicals learning to use a variety of + + + align:start position:0% +chemicals learning to use a variety of +different purification techniques + + align:start position:0% +different purification techniques + + + align:start position:0% +different purification techniques +efficiently and effectively is key to + + align:start position:0% +efficiently and effectively is key to + + + align:start position:0% +efficiently and effectively is key to +becoming a successful + + align:start position:0% +becoming a successful + + + align:start position:0% +becoming a successful +experimentalist recrystallization is one + + align:start position:0% +experimentalist recrystallization is one + + + align:start position:0% +experimentalist recrystallization is one +powerful method for the purification of + + align:start position:0% +powerful method for the purification of + + + align:start position:0% +powerful method for the purification of +crystall and solids this video will + + align:start position:0% +crystall and solids this video will + + + align:start position:0% +crystall and solids this video will +outline the purification of napoline by + + align:start position:0% +outline the purification of napoline by + + + align:start position:0% +outline the purification of napoline by +recrystallization + + align:start position:0% + + + + align:start position:0% + +the technique of recrystallization + + align:start position:0% +the technique of recrystallization + + + align:start position:0% +the technique of recrystallization +involves five main steps first an + + align:start position:0% +involves five main steps first an + + + align:start position:0% +involves five main steps first an +appropriate solvent is determined + + align:start position:0% +appropriate solvent is determined + + + align:start position:0% +appropriate solvent is determined +recrystallizations can be carried out + + align:start position:0% +recrystallizations can be carried out + + + align:start position:0% +recrystallizations can be carried out +using either one or a mixture of two + + align:start position:0% +using either one or a mixture of two + + + align:start position:0% +using either one or a mixture of two +solvents depending on the solubility of + + align:start position:0% +solvents depending on the solubility of + + + align:start position:0% +solvents depending on the solubility of +the + + align:start position:0% +the + + + align:start position:0% +the +sample next the sample is dissolved in a + + align:start position:0% +sample next the sample is dissolved in a + + + align:start position:0% +sample next the sample is dissolved in a +minimal amount of the proper hot + + align:start position:0% +minimal amount of the proper hot + + + align:start position:0% +minimal amount of the proper hot +solvent at this point the solution can + + align:start position:0% +solvent at this point the solution can + + + align:start position:0% +solvent at this point the solution can +be decolorized and insoluble + + align:start position:0% +be decolorized and insoluble + + + align:start position:0% +be decolorized and insoluble +contaminants can be removed by + + align:start position:0% +contaminants can be removed by + + + align:start position:0% +contaminants can be removed by +performing a hot filtration + + align:start position:0% +performing a hot filtration + + + align:start position:0% +performing a hot filtration +the resulting solution is then cooled to + + align:start position:0% +the resulting solution is then cooled to + + + align:start position:0% +the resulting solution is then cooled to +induce + + align:start position:0% +induce + + + align:start position:0% +induce +crystallization and finally the purified + + align:start position:0% +crystallization and finally the purified + + + align:start position:0% +crystallization and finally the purified +crystals are collected by filtration + + align:start position:0% +crystals are collected by filtration + + + align:start position:0% +crystals are collected by filtration +washed and + + align:start position:0% +washed and + + + align:start position:0% +washed and +dried this video will first outline the + + align:start position:0% +dried this video will first outline the + + + align:start position:0% +dried this video will first outline the +general procedure for carrying out a one + + align:start position:0% +general procedure for carrying out a one + + + align:start position:0% +general procedure for carrying out a one +solvent recrystallization of napthalene + + align:start position:0% +solvent recrystallization of napthalene + + + align:start position:0% +solvent recrystallization of napthalene +followed by instructions for adapting + + align:start position:0% +followed by instructions for adapting + + + align:start position:0% +followed by instructions for adapting +the procedure to a two solvent + + align:start position:0% +the procedure to a two solvent + + + align:start position:0% +the procedure to a two solvent +recrystallization choosing an + + align:start position:0% +recrystallization choosing an + + + align:start position:0% +recrystallization choosing an +appropriate solvent for a + + align:start position:0% +appropriate solvent for a + + + align:start position:0% +appropriate solvent for a +recrystallization is a very important + + align:start position:0% +recrystallization is a very important + + + align:start position:0% +recrystallization is a very important +step you won't get acceptable results if + + align:start position:0% +step you won't get acceptable results if + + + align:start position:0% +step you won't get acceptable results if +you don't pick carefully it is helpful + + align:start position:0% +you don't pick carefully it is helpful + + + align:start position:0% +you don't pick carefully it is helpful +to have a variety of solvents at your + + align:start position:0% +to have a variety of solvents at your + + + align:start position:0% +to have a variety of solvents at your +disposal if solubility data for your + + align:start position:0% +disposal if solubility data for your + + + align:start position:0% +disposal if solubility data for your +compounds has been published this will + + align:start position:0% +compounds has been published this will + + + align:start position:0% +compounds has been published this will +help you to narrow the range of + + align:start position:0% +help you to narrow the range of + + + align:start position:0% +help you to narrow the range of +potential + + align:start position:0% +potential + + + align:start position:0% +potential +candidates once you have decided on a + + align:start position:0% +candidates once you have decided on a + + + align:start position:0% +candidates once you have decided on a +few Prime contenders you will perform + + align:start position:0% +few Prime contenders you will perform + + + align:start position:0% +few Prime contenders you will perform +solubility tests to find the ideal + + align:start position:0% +solubility tests to find the ideal + + + align:start position:0% +solubility tests to find the ideal +choice you will need a hot water bath + + align:start position:0% +choice you will need a hot water bath + + + align:start position:0% +choice you will need a hot water bath +for the solubility test as well as the + + align:start position:0% + + + + align:start position:0% + +recrystallization caution organic + + align:start position:0% +recrystallization caution organic + + + align:start position:0% +recrystallization caution organic +solvents are + + align:start position:0% +solvents are + + + align:start position:0% +solvents are +flammable never heat over an open + + align:start position:0% + + + + align:start position:0% + +flame to set up a water bath place a + + align:start position:0% +flame to set up a water bath place a + + + align:start position:0% +flame to set up a water bath place a +large crystallizing dish about half full + + align:start position:0% +large crystallizing dish about half full + + + align:start position:0% +large crystallizing dish about half full +with water on a hot plate add some + + align:start position:0% +with water on a hot plate add some + + + align:start position:0% +with water on a hot plate add some +boiling stones and turn on the heat + + align:start position:0% +boiling stones and turn on the heat + + + align:start position:0% +boiling stones and turn on the heat +don't turn it up all the way start + + align:start position:0% +don't turn it up all the way start + + + align:start position:0% +don't turn it up all the way start +halfway and adjust from there + + align:start position:0% +halfway and adjust from there + + + align:start position:0% +halfway and adjust from there +to perform a solubility test place + + align:start position:0% +to perform a solubility test place + + + align:start position:0% +to perform a solubility test place +approximately 20 mg of your compound in + + align:start position:0% +approximately 20 mg of your compound in + + + align:start position:0% +approximately 20 mg of your compound in +a test + + align:start position:0% +a test + + + align:start position:0% +a test +tube add a half of a milliliter of the + + align:start position:0% +tube add a half of a milliliter of the + + + align:start position:0% +tube add a half of a milliliter of the +appropriate solvent and swirl wait a + + align:start position:0% +appropriate solvent and swirl wait a + + + align:start position:0% +appropriate solvent and swirl wait a +couple of minutes and then make note of + + align:start position:0% +couple of minutes and then make note of + + + align:start position:0% +couple of minutes and then make note of +whether or not the compound + + align:start position:0% + + + + align:start position:0% + +dissolves for example at room + + align:start position:0% +dissolves for example at room + + + align:start position:0% +dissolves for example at room +temperature napthalene is insoluble in + + align:start position:0% +temperature napthalene is insoluble in + + + align:start position:0% +temperature napthalene is insoluble in +ethanol and water but soluble in uine + + align:start position:0% +ethanol and water but soluble in uine + + + align:start position:0% +ethanol and water but soluble in uine +and + + align:start position:0% + + + + align:start position:0% + +acetone if there is still solid + + align:start position:0% +acetone if there is still solid + + + align:start position:0% +acetone if there is still solid +remaining clamp the tube and heat it in + + align:start position:0% +remaining clamp the tube and heat it in + + + align:start position:0% +remaining clamp the tube and heat it in +the water bath until the solvent boils + + align:start position:0% +the water bath until the solvent boils + + + align:start position:0% +the water bath until the solvent boils +swirl the tube and make note of whether + + align:start position:0% +swirl the tube and make note of whether + + + align:start position:0% +swirl the tube and make note of whether +or not the compound + + align:start position:0% +or not the compound + + + align:start position:0% +or not the compound +dissolves after heating napthalene is + + align:start position:0% +dissolves after heating napthalene is + + + align:start position:0% +dissolves after heating napthalene is +still insoluble in water but it is now + + align:start position:0% +still insoluble in water but it is now + + + align:start position:0% +still insoluble in water but it is now +soluble in hot + + align:start position:0% +soluble in hot + + + align:start position:0% +soluble in hot +ethanol now that you have finished the + + align:start position:0% +ethanol now that you have finished the + + + align:start position:0% +ethanol now that you have finished the +solubility test how do you decide which + + align:start position:0% +solubility test how do you decide which + + + align:start position:0% +solubility test how do you decide which +solvent to use for your + + align:start position:0% +solvent to use for your + + + align:start position:0% +solvent to use for your +recrystallization the ideal solvent is + + align:start position:0% +recrystallization the ideal solvent is + + + align:start position:0% +recrystallization the ideal solvent is +one in which your compound is insoluble + + align:start position:0% +one in which your compound is insoluble + + + align:start position:0% +one in which your compound is insoluble +at room + + align:start position:0% +at room + + + align:start position:0% +at room +temperature but soluble at the boiling + + align:start position:0% +temperature but soluble at the boiling + + + align:start position:0% +temperature but soluble at the boiling +point remember at room temperature + + align:start position:0% +point remember at room temperature + + + align:start position:0% +point remember at room temperature +napthalene was soluble in both polline + + align:start position:0% +napthalene was soluble in both polline + + + align:start position:0% +napthalene was soluble in both polline +and acetone so neither of these will + + align:start position:0% +and acetone so neither of these will + + + align:start position:0% +and acetone so neither of these will +work after heating napthalene remained + + align:start position:0% +work after heating napthalene remained + + + align:start position:0% +work after heating napthalene remained +insoluble in water even at the boiling + + align:start position:0% +insoluble in water even at the boiling + + + align:start position:0% +insoluble in water even at the boiling +point + + align:start position:0% + + + + align:start position:0% + +this means that ethanol is the solvent + + align:start position:0% +this means that ethanol is the solvent + + + align:start position:0% +this means that ethanol is the solvent +of choice it dissolves the sample at its + + align:start position:0% +of choice it dissolves the sample at its + + + align:start position:0% +of choice it dissolves the sample at its +boiling point but not at room + + align:start position:0% +boiling point but not at room + + + align:start position:0% +boiling point but not at room +temperature now that we have decided on + + align:start position:0% +temperature now that we have decided on + + + align:start position:0% +temperature now that we have decided on +a solvent it is time to dissolve the + + align:start position:0% +a solvent it is time to dissolve the + + + align:start position:0% +a solvent it is time to dissolve the +sample in some hot + + align:start position:0% +sample in some hot + + + align:start position:0% +sample in some hot +ethanol get ready by heating some + + align:start position:0% +ethanol get ready by heating some + + + align:start position:0% +ethanol get ready by heating some +ethanol in the water bath remember to + + align:start position:0% +ethanol in the water bath remember to + + + align:start position:0% +ethanol in the water bath remember to +add some boiling stones and clamp the + + align:start position:0% +add some boiling stones and clamp the + + + align:start position:0% +add some boiling stones and clamp the +flask securely so that it doesn't tip + + align:start position:0% +flask securely so that it doesn't tip + + + align:start position:0% +flask securely so that it doesn't tip +over + + align:start position:0% + + + + align:start position:0% + +place the sample in an Erland Meer flask + + align:start position:0% +place the sample in an Erland Meer flask + + + align:start position:0% +place the sample in an Erland Meer flask +but before adding solvent it is a good + + align:start position:0% +but before adding solvent it is a good + + + align:start position:0% +but before adding solvent it is a good +idea to set aside a small Crystal it may + + align:start position:0% +idea to set aside a small Crystal it may + + + align:start position:0% +idea to set aside a small Crystal it may +come in handy later if you have trouble + + align:start position:0% +come in handy later if you have trouble + + + align:start position:0% +come in handy later if you have trouble +getting crystals to + + align:start position:0% + + + + align:start position:0% + +form when dissolving your sample use a + + align:start position:0% +form when dissolving your sample use a + + + align:start position:0% +form when dissolving your sample use a +minimal amount of hot solvent this will + + align:start position:0% +minimal amount of hot solvent this will + + + align:start position:0% +minimal amount of hot solvent this will +ensure good recovery of crystals in the + + align:start position:0% +ensure good recovery of crystals in the + + + align:start position:0% +ensure good recovery of crystals in the +end add hot solvent in small amounts + + align:start position:0% +end add hot solvent in small amounts + + + align:start position:0% +end add hot solvent in small amounts +swirling and heating in between each + + align:start position:0% +swirling and heating in between each + + + align:start position:0% +swirling and heating in between each +addition until the sample just + + align:start position:0% + + + + align:start position:0% + +dissolves caution if it won't dissolve + + align:start position:0% +dissolves caution if it won't dissolve + + + align:start position:0% +dissolves caution if it won't dissolve +it's probably an impurity + + align:start position:0% + + + + align:start position:0% + +now that the sample is in solution + + align:start position:0% +now that the sample is in solution + + + align:start position:0% +now that the sample is in solution +impurities can be removed through + + align:start position:0% +impurities can be removed through + + + align:start position:0% +impurities can be removed through +decoloration and hot + + align:start position:0% +decoloration and hot + + + align:start position:0% +decoloration and hot +filtration take a close look at the + + align:start position:0% +filtration take a close look at the + + + align:start position:0% +filtration take a close look at the +solution is it the right color for + + align:start position:0% +solution is it the right color for + + + align:start position:0% +solution is it the right color for +example if you're expecting white + + align:start position:0% +example if you're expecting white + + + align:start position:0% +example if you're expecting white +crystals and your solution is yellow + + align:start position:0% +crystals and your solution is yellow + + + align:start position:0% +crystals and your solution is yellow +then there is a soluble + + align:start position:0% +then there is a soluble + + + align:start position:0% +then there is a soluble +impurity one easy way to remove small + + align:start position:0% +impurity one easy way to remove small + + + align:start position:0% +impurity one easy way to remove small +amounts of colored impurities is with + + align:start position:0% +amounts of colored impurities is with + + + align:start position:0% +amounts of colored impurities is with +activated charcoal before adding any + + align:start position:0% +activated charcoal before adding any + + + align:start position:0% +activated charcoal before adding any +charcoal cool Your solution to slightly + + align:start position:0% +charcoal cool Your solution to slightly + + + align:start position:0% +charcoal cool Your solution to slightly +below the boiling + + align:start position:0% + + + + align:start position:0% + +point caution adding charcoal to a + + align:start position:0% +point caution adding charcoal to a + + + align:start position:0% +point caution adding charcoal to a +boiling solution will cause it to boil + + align:start position:0% + + + + align:start position:0% + +over add a small amount of charcoal to + + align:start position:0% +over add a small amount of charcoal to + + + align:start position:0% +over add a small amount of charcoal to +absorb the impurity do not add too much + + align:start position:0% +absorb the impurity do not add too much + + + align:start position:0% +absorb the impurity do not add too much +or the charcoal will also absorb your + + align:start position:0% + + + + align:start position:0% + +compound swirl the flask + + align:start position:0% + + + + align:start position:0% + +boil it in the water bath for 2 to 3 + + align:start position:0% +boil it in the water bath for 2 to 3 + + + align:start position:0% +boil it in the water bath for 2 to 3 +minutes charcoal is very fine and can be + + align:start position:0% +minutes charcoal is very fine and can be + + + align:start position:0% +minutes charcoal is very fine and can be +hard to remove by + + align:start position:0% +hard to remove by + + + align:start position:0% +hard to remove by +filtration it is easiest to add a small + + align:start position:0% +filtration it is easiest to add a small + + + align:start position:0% +filtration it is easiest to add a small +amount of a filtering agent such as sea + + align:start position:0% +amount of a filtering agent such as sea + + + align:start position:0% +amount of a filtering agent such as sea +light to absorb the charcoal and + + align:start position:0% +light to absorb the charcoal and + + + align:start position:0% +light to absorb the charcoal and +facilitate the + + align:start position:0% +facilitate the + + + align:start position:0% +facilitate the +filtration add only a small amount swirl + + align:start position:0% +filtration add only a small amount swirl + + + align:start position:0% +filtration add only a small amount swirl +the flask and heat it once again for 2 + + align:start position:0% +the flask and heat it once again for 2 + + + align:start position:0% +the flask and heat it once again for 2 +to 3 minutes before performing a hot + + align:start position:0% +to 3 minutes before performing a hot + + + align:start position:0% +to 3 minutes before performing a hot +filtration if the solution is is + + align:start position:0% +filtration if the solution is is + + + align:start position:0% +filtration if the solution is is +colorless the decoloration step is + + align:start position:0% +colorless the decoloration step is + + + align:start position:0% +colorless the decoloration step is +unnecessary but you still need to look + + align:start position:0% +unnecessary but you still need to look + + + align:start position:0% +unnecessary but you still need to look +carefully for any undissolved solid in + + align:start position:0% +carefully for any undissolved solid in + + + align:start position:0% +carefully for any undissolved solid in +the + + align:start position:0% +the + + + align:start position:0% +the +flask if you find any it can be removed + + align:start position:0% +flask if you find any it can be removed + + + align:start position:0% +flask if you find any it can be removed +by performing a hot gravity filtration + + align:start position:0% +by performing a hot gravity filtration + + + align:start position:0% +by performing a hot gravity filtration +with fluted filter paper vacuum + + align:start position:0% +with fluted filter paper vacuum + + + align:start position:0% +with fluted filter paper vacuum +filtrations cool the solution too much + + align:start position:0% +filtrations cool the solution too much + + + align:start position:0% +filtrations cool the solution too much +and crystals are lost on the filter + + align:start position:0% +and crystals are lost on the filter + + + align:start position:0% +and crystals are lost on the filter +paper and + + align:start position:0% + + + + align:start position:0% + +funnel before filtering Your solution + + align:start position:0% +funnel before filtering Your solution + + + align:start position:0% +funnel before filtering Your solution +add some excess solvent and heat it to + + align:start position:0% +add some excess solvent and heat it to + + + align:start position:0% +add some excess solvent and heat it to +the boiling point to ensure that the + + align:start position:0% +the boiling point to ensure that the + + + align:start position:0% +the boiling point to ensure that the +compound stays dissolved during the + + align:start position:0% +compound stays dissolved during the + + + align:start position:0% +compound stays dissolved during the +filtration wet the filter paper with + + align:start position:0% +filtration wet the filter paper with + + + align:start position:0% +filtration wet the filter paper with +some hot solvent and filter the solution + + align:start position:0% + + + + align:start position:0% + +rinse the flask two or three times with + + align:start position:0% +rinse the flask two or three times with + + + align:start position:0% +rinse the flask two or three times with +hot solvent filtering each + + align:start position:0% + + + + align:start position:0% + +rinse finally rinse the filter paper + + align:start position:0% +rinse finally rinse the filter paper + + + align:start position:0% +rinse finally rinse the filter paper +with hot solvent to minimize product + + align:start position:0% +with hot solvent to minimize product + + + align:start position:0% +with hot solvent to minimize product +loss + + align:start position:0% + + + + align:start position:0% + +crystals frequently form in the filtrate + + align:start position:0% +crystals frequently form in the filtrate + + + align:start position:0% +crystals frequently form in the filtrate +during the filtration but they easily + + align:start position:0% +during the filtration but they easily + + + align:start position:0% +during the filtration but they easily +redissolve with + + align:start position:0% + + + + align:start position:0% + +heating caution your compound is no + + align:start position:0% +heating caution your compound is no + + + align:start position:0% +heating caution your compound is no +longer dissolved in a minimum amount of + + align:start position:0% +longer dissolved in a minimum amount of + + + align:start position:0% +longer dissolved in a minimum amount of +solvent before proceeding to The Next + + align:start position:0% +solvent before proceeding to The Next + + + align:start position:0% +solvent before proceeding to The Next +Step you need to boil away the excess + + align:start position:0% +Step you need to boil away the excess + + + align:start position:0% +Step you need to boil away the excess +solvent remember to add a few boiling + + align:start position:0% +solvent remember to add a few boiling + + + align:start position:0% +solvent remember to add a few boiling +stones to the solution and boil until + + align:start position:0% +stones to the solution and boil until + + + align:start position:0% +stones to the solution and boil until +solid begins to + + align:start position:0% + + + + align:start position:0% + +form at this point add a small amount of + + align:start position:0% +form at this point add a small amount of + + + align:start position:0% +form at this point add a small amount of +hot solvent to redissolve the + + align:start position:0% + + + + align:start position:0% + +solid when your sample is once again + + align:start position:0% +solid when your sample is once again + + + align:start position:0% +solid when your sample is once again +dissolved in the minimum amount of + + align:start position:0% +dissolved in the minimum amount of + + + align:start position:0% +dissolved in the minimum amount of +solvent set it side to + + align:start position:0% + + + + align:start position:0% + +cool cover the flask to prevent + + align:start position:0% +cool cover the flask to prevent + + + align:start position:0% +cool cover the flask to prevent +contamination with Airborne particles + + align:start position:0% +contamination with Airborne particles + + + align:start position:0% +contamination with Airborne particles +and allow it to cool to room temperature + + align:start position:0% + + + + align:start position:0% + +undisturbed the flask can also be placed + + align:start position:0% +undisturbed the flask can also be placed + + + align:start position:0% +undisturbed the flask can also be placed +in a beaker stuffed with a paper towel + + align:start position:0% +in a beaker stuffed with a paper towel + + + align:start position:0% +in a beaker stuffed with a paper towel +to slow down the Cooling and promote + + align:start position:0% +to slow down the Cooling and promote + + + align:start position:0% +to slow down the Cooling and promote +slow crystal growth this is especially + + align:start position:0% +slow crystal growth this is especially + + + align:start position:0% +slow crystal growth this is especially +helpful in a cold + + align:start position:0% + + + + align:start position:0% + +laboratory ideally crystals will begin + + align:start position:0% +laboratory ideally crystals will begin + + + align:start position:0% +laboratory ideally crystals will begin +to form as the solution cools you may + + align:start position:0% +to form as the solution cools you may + + + align:start position:0% +to form as the solution cools you may +want to watch it can be very beautiful + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +if the solution reaches room temperature + + align:start position:0% +if the solution reaches room temperature + + + align:start position:0% +if the solution reaches room temperature +without crystal growth you may want to + + align:start position:0% +without crystal growth you may want to + + + align:start position:0% +without crystal growth you may want to +try a trick or two to jump start the + + align:start position:0% +try a trick or two to jump start the + + + align:start position:0% +try a trick or two to jump start the +process + + align:start position:0% + + + + align:start position:0% + +first try scratching the side or bottom + + align:start position:0% +first try scratching the side or bottom + + + align:start position:0% +first try scratching the side or bottom +of the flask with a glass rod don't + + align:start position:0% +of the flask with a glass rod don't + + + align:start position:0% +of the flask with a glass rod don't +press too hard or you'll break + + align:start position:0% + + + + align:start position:0% + +it if that doesn't + + align:start position:0% + + + + align:start position:0% + +work try adding the seed Crystal that + + align:start position:0% +work try adding the seed Crystal that + + + align:start position:0% +work try adding the seed Crystal that +you set aside at the beginning + + align:start position:0% + + + + align:start position:0% + +if you forgot to set aside a seed + + align:start position:0% + + + + align:start position:0% + +Crystal you can also try dipping a glass + + align:start position:0% +Crystal you can also try dipping a glass + + + align:start position:0% +Crystal you can also try dipping a glass +rod in the solution letting it dry so + + align:start position:0% +rod in the solution letting it dry so + + + align:start position:0% +rod in the solution letting it dry so +that the minute crystals form on the + + align:start position:0% +that the minute crystals form on the + + + align:start position:0% +that the minute crystals form on the +surface and then dipping it back in + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +when crystallization has begun and your + + align:start position:0% +when crystallization has begun and your + + + align:start position:0% +when crystallization has begun and your +flask is at room temperature place it in + + align:start position:0% +flask is at room temperature place it in + + + align:start position:0% +flask is at room temperature place it in +an ice bath to drive the crystallization + + align:start position:0% +an ice bath to drive the crystallization + + + align:start position:0% +an ice bath to drive the crystallization +to completion leave it in the ice bath + + align:start position:0% +to completion leave it in the ice bath + + + align:start position:0% +to completion leave it in the ice bath +for at least 15 minutes before + + align:start position:0% +for at least 15 minutes before + + + align:start position:0% +for at least 15 minutes before +collecting the + + align:start position:0% +collecting the + + + align:start position:0% +collecting the +crystals the final step in a + + align:start position:0% +crystals the final step in a + + + align:start position:0% +crystals the final step in a +recrystallization is collecting and + + align:start position:0% +recrystallization is collecting and + + + align:start position:0% +recrystallization is collecting and +washing the purified crystals to do this + + align:start position:0% +washing the purified crystals to do this + + + align:start position:0% +washing the purified crystals to do this +you will need a flask of ice cold + + align:start position:0% +you will need a flask of ice cold + + + align:start position:0% +you will need a flask of ice cold +solvent ethanol in this case and a + + align:start position:0% +solvent ethanol in this case and a + + + align:start position:0% +solvent ethanol in this case and a +vacuum filtration + + align:start position:0% + + + + align:start position:0% + +setup always use a clean dry flask to + + align:start position:0% +setup always use a clean dry flask to + + + align:start position:0% +setup always use a clean dry flask to +collect the filate in many cases a + + align:start position:0% +collect the filate in many cases a + + + align:start position:0% +collect the filate in many cases a +second batch of crystals can be obtained + + align:start position:0% +second batch of crystals can be obtained + + + align:start position:0% +second batch of crystals can be obtained +by concentrating the mother liquor and + + align:start position:0% +by concentrating the mother liquor and + + + align:start position:0% +by concentrating the mother liquor and +crystallizing a second time turn the + + align:start position:0% +crystallizing a second time turn the + + + align:start position:0% +crystallizing a second time turn the +vacuum on and wet the filter paper with + + align:start position:0% +vacuum on and wet the filter paper with + + + align:start position:0% +vacuum on and wet the filter paper with +a small amount of cold + + align:start position:0% +a small amount of cold + + + align:start position:0% +a small amount of cold +solvent pour the crystals and the mother + + align:start position:0% +solvent pour the crystals and the mother + + + align:start position:0% +solvent pour the crystals and the mother +liquor onto the funnel using cold + + align:start position:0% +liquor onto the funnel using cold + + + align:start position:0% +liquor onto the funnel using cold +solvent to transfer all of the crystals + + align:start position:0% +solvent to transfer all of the crystals + + + align:start position:0% +solvent to transfer all of the crystals +from the FL + + align:start position:0% + + + + align:start position:0% + +flask use cold solvent to wash the + + align:start position:0% +flask use cold solvent to wash the + + + align:start position:0% +flask use cold solvent to wash the +crystals and pull air through them to + + align:start position:0% +crystals and pull air through them to + + + align:start position:0% +crystals and pull air through them to +begin the drying process + + align:start position:0% + + + + align:start position:0% + +after pulling air through the crystals + + align:start position:0% +after pulling air through the crystals + + + align:start position:0% +after pulling air through the crystals +for a few minutes scrape the crystals + + align:start position:0% +for a few minutes scrape the crystals + + + align:start position:0% +for a few minutes scrape the crystals +onto a weighing dish and spread them out + + align:start position:0% +onto a weighing dish and spread them out + + + align:start position:0% +onto a weighing dish and spread them out +to facilitate drying depending on the + + align:start position:0% +to facilitate drying depending on the + + + align:start position:0% +to facilitate drying depending on the +compound the crystals can be dried in a + + align:start position:0% +compound the crystals can be dried in a + + + align:start position:0% +compound the crystals can be dried in a +desiccator an oven or on a vacuum line + + align:start position:0% + + + + align:start position:0% + +when one ideal solvent cannot be found + + align:start position:0% +when one ideal solvent cannot be found + + + align:start position:0% +when one ideal solvent cannot be found +for a crystallization it is possible to + + align:start position:0% +for a crystallization it is possible to + + + align:start position:0% +for a crystallization it is possible to +use a mixture of two + + align:start position:0% +use a mixture of two + + + align:start position:0% +use a mixture of two +solvents once again you must choose the + + align:start position:0% +solvents once again you must choose the + + + align:start position:0% +solvents once again you must choose the +solvents very + + align:start position:0% +solvents very + + + align:start position:0% +solvents very +carefully in the first solvent solvent + + align:start position:0% +carefully in the first solvent solvent + + + align:start position:0% +carefully in the first solvent solvent +one your sample should be soluble even + + align:start position:0% +one your sample should be soluble even + + + align:start position:0% +one your sample should be soluble even +at room + + align:start position:0% + + + + align:start position:0% + +temperature and in the second solvent + + align:start position:0% +temperature and in the second solvent + + + align:start position:0% +temperature and in the second solvent +solvent 2 your sample must remain + + align:start position:0% +solvent 2 your sample must remain + + + align:start position:0% +solvent 2 your sample must remain +insoluble even at the boiling point + + align:start position:0% +insoluble even at the boiling point + + + align:start position:0% +insoluble even at the boiling point +the two solvents must also be missable + + align:start position:0% +the two solvents must also be missable + + + align:start position:0% +the two solvents must also be missable +at all ratios so that they don't + + align:start position:0% +at all ratios so that they don't + + + align:start position:0% +at all ratios so that they don't +separate out into different layers + + align:start position:0% +separate out into different layers + + + align:start position:0% +separate out into different layers +during the + + align:start position:0% + + + + align:start position:0% + +recrystallization we know from our + + align:start position:0% +recrystallization we know from our + + + align:start position:0% +recrystallization we know from our +solubility tests that napthalene is + + align:start position:0% +solubility tests that napthalene is + + + align:start position:0% +solubility tests that napthalene is +soluble in both toine and acetone even + + align:start position:0% +soluble in both toine and acetone even + + + align:start position:0% +soluble in both toine and acetone even +at room temperature so which one should + + align:start position:0% +at room temperature so which one should + + + align:start position:0% +at room temperature so which one should +we choose to be our solvent + + align:start position:0% +we choose to be our solvent + + + align:start position:0% +we choose to be our solvent +one that depends entirely on our choice + + align:start position:0% +one that depends entirely on our choice + + + align:start position:0% +one that depends entirely on our choice +for solvent + + align:start position:0% +for solvent + + + align:start position:0% +for solvent +2 we know from our Sol ubility tests + + align:start position:0% +2 we know from our Sol ubility tests + + + align:start position:0% +2 we know from our Sol ubility tests +that napthalene is insoluble in water + + align:start position:0% +that napthalene is insoluble in water + + + align:start position:0% +that napthalene is insoluble in water +even at the boiling point that makes + + align:start position:0% +even at the boiling point that makes + + + align:start position:0% +even at the boiling point that makes +water a very good candidate for solvent + + align:start position:0% + + + + align:start position:0% + +to while acetone and water are missible + + align:start position:0% +to while acetone and water are missible + + + align:start position:0% +to while acetone and water are missible +toine and water are + + align:start position:0% +toine and water are + + + align:start position:0% +toine and water are +not the recrystallization of napthalene + + align:start position:0% +not the recrystallization of napthalene + + + align:start position:0% +not the recrystallization of napthalene +will be carried out using acetone as + + align:start position:0% +will be carried out using acetone as + + + align:start position:0% +will be carried out using acetone as +solvent 1 and water as solvent + + align:start position:0% + + + + align:start position:0% + +two as before dissolve your sample in + + align:start position:0% +two as before dissolve your sample in + + + align:start position:0% +two as before dissolve your sample in +the minimal amount of hot solvent in + + align:start position:0% +the minimal amount of hot solvent in + + + align:start position:0% +the minimal amount of hot solvent in +this case solvent one + + align:start position:0% + + + + align:start position:0% + +acetone add just enough hot solvent to + + align:start position:0% +acetone add just enough hot solvent to + + + align:start position:0% +acetone add just enough hot solvent to +obtain a clear + + align:start position:0% + + + + align:start position:0% + +solution then add solvent two in this + + align:start position:0% +solution then add solvent two in this + + + align:start position:0% +solution then add solvent two in this +case water dropwise until the solution + + align:start position:0% +case water dropwise until the solution + + + align:start position:0% +case water dropwise until the solution +turns + + align:start position:0% + + + + align:start position:0% + +cloudy swirl and heat the solution to + + align:start position:0% +cloudy swirl and heat the solution to + + + align:start position:0% +cloudy swirl and heat the solution to +make sure that the cloudiness + + align:start position:0% + + + + align:start position:0% + +persists and do not confuse cloudiness + + align:start position:0% +persists and do not confuse cloudiness + + + align:start position:0% +persists and do not confuse cloudiness +with the turbidity that is observed upon + + align:start position:0% +with the turbidity that is observed upon + + + align:start position:0% +with the turbidity that is observed upon +mixing two solvents + + align:start position:0% + + + + align:start position:0% + +together once you have obtained a + + align:start position:0% +together once you have obtained a + + + align:start position:0% +together once you have obtained a +consistently cloudy solution add hot + + align:start position:0% +consistently cloudy solution add hot + + + align:start position:0% +consistently cloudy solution add hot +solvent one dropwise until the solution + + align:start position:0% +solvent one dropwise until the solution + + + align:start position:0% +solvent one dropwise until the solution +just turns + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +clear now you're ready to set the + + align:start position:0% +clear now you're ready to set the + + + align:start position:0% +clear now you're ready to set the +solution aside to + + align:start position:0% +solution aside to + + + align:start position:0% +solution aside to +cool once the crystallization is + + align:start position:0% +cool once the crystallization is + + + align:start position:0% +cool once the crystallization is +complete cool down a mixture of solvents + + align:start position:0% +complete cool down a mixture of solvents + + + align:start position:0% +complete cool down a mixture of solvents +in a ratio similar to that which you + + align:start position:0% +in a ratio similar to that which you + + + align:start position:0% +in a ratio similar to that which you +recrystallized + + align:start position:0% +recrystallized + + + align:start position:0% +recrystallized +from the this cold mixture will be used + + align:start position:0% +from the this cold mixture will be used + + + align:start position:0% +from the this cold mixture will be used +to collect and wash your crystals + + align:start position:0% +to collect and wash your crystals + + + align:start position:0% +to collect and wash your crystals +[Music] + + align:start position:0% + + + + align:start position:0% + +remember this video is intended to help + + align:start position:0% +remember this video is intended to help + + + align:start position:0% +remember this video is intended to help +you prepare for lab by providing a + + align:start position:0% +you prepare for lab by providing a + + + align:start position:0% +you prepare for lab by providing a +demonstration of the proper experimental + + align:start position:0% +demonstration of the proper experimental + + + align:start position:0% +demonstration of the proper experimental +technique it is not intended as a + + align:start position:0% +technique it is not intended as a + + + align:start position:0% +technique it is not intended as a +replacement for reading your lab manual + + align:start position:0% +replacement for reading your lab manual + + + align:start position:0% +replacement for reading your lab manual +or the supplementary material in order + + align:start position:0% +or the supplementary material in order + + + align:start position:0% +or the supplementary material in order +to become a great experimentalist it is + + align:start position:0% +to become a great experimentalist it is + + + align:start position:0% +to become a great experimentalist it is +important that you understand both + + align:start position:0% +important that you understand both + + + align:start position:0% +important that you understand both +Theory and technique now it's your turn + + align:start position:0% +Theory and technique now it's your turn + + + align:start position:0% +Theory and technique now it's your turn +good luck + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/Q9XXlbNaOXI.txt b/Q9XXlbNaOXI.txt new file mode 100644 index 0000000000000000000000000000000000000000..26fe5f5723c0eaf2c566522467c44306c91ef593 --- /dev/null +++ b/Q9XXlbNaOXI.txt @@ -0,0 +1,5523 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +in the urban Energy Systems and policy + + align:start position:0% +in the urban Energy Systems and policy + + + align:start position:0% +in the urban Energy Systems and policy +plots at MIT my name is David Sue I'm a + + align:start position:0% +plots at MIT my name is David Sue I'm a + + + align:start position:0% +plots at MIT my name is David Sue I'm a +professor of urban studies and planning + + align:start position:0% +professor of urban studies and planning + + + align:start position:0% +professor of urban studies and planning +and today we're going to talk about + + align:start position:0% +and today we're going to talk about + + + align:start position:0% +and today we're going to talk about +cities and adjust energy transition + + align:start position:0% +cities and adjust energy transition + + + align:start position:0% +cities and adjust energy transition +what is a Just Energy transition going + + align:start position:0% +what is a Just Energy transition going + + + align:start position:0% +what is a Just Energy transition going +to look like what does it mean for us to + + align:start position:0% +to look like what does it mean for us to + + + align:start position:0% +to look like what does it mean for us to +try to achieve a just or Equitable + + align:start position:0% +try to achieve a just or Equitable + + + align:start position:0% +try to achieve a just or Equitable +Equitable energy transition + + align:start position:0% +Equitable energy transition + + + align:start position:0% +Equitable energy transition +the readings for today are listed on + + align:start position:0% +the readings for today are listed on + + + align:start position:0% +the readings for today are listed on +this slide a lot of this lecture will be + + align:start position:0% +this slide a lot of this lecture will be + + + align:start position:0% +this slide a lot of this lecture will be +setting up our discussion in class of + + align:start position:0% +setting up our discussion in class of + + + align:start position:0% +setting up our discussion in class of +these readings it'll be a fairly short + + align:start position:0% +these readings it'll be a fairly short + + + align:start position:0% +these readings it'll be a fairly short +lecture today I think that's going to be + + align:start position:0% +lecture today I think that's going to be + + + align:start position:0% +lecture today I think that's going to be +the best way to set up discussion and + + align:start position:0% +the best way to set up discussion and + + + align:start position:0% +the best way to set up discussion and +hopefully we have a lively discussion in + + align:start position:0% +hopefully we have a lively discussion in + + + align:start position:0% +hopefully we have a lively discussion in +class + + align:start position:0% +class + + + align:start position:0% +class +let me just start with a few stories to + + align:start position:0% +let me just start with a few stories to + + + align:start position:0% +let me just start with a few stories to +kind of supplement the reading I'm going + + align:start position:0% +kind of supplement the reading I'm going + + + align:start position:0% +kind of supplement the reading I'm going +to start with this rather hail looking + + align:start position:0% +to start with this rather hail looking + + + align:start position:0% +to start with this rather hail looking +fellow president Theodore Roosevelt he's + + align:start position:0% +fellow president Theodore Roosevelt he's + + + align:start position:0% +fellow president Theodore Roosevelt he's +the 26th president of the United States + + align:start position:0% +the 26th president of the United States + + + align:start position:0% +the 26th president of the United States +He is known in his lifetime as a soldier + + align:start position:0% +He is known in his lifetime as a soldier + + + align:start position:0% +He is known in his lifetime as a soldier +a naturalist a writer a politician + + align:start position:0% +a naturalist a writer a politician + + + align:start position:0% +a naturalist a writer a politician +reformer and imperialist uh he does all + + align:start position:0% +reformer and imperialist uh he does all + + + align:start position:0% +reformer and imperialist uh he does all +this despite being a Harvard graduate + + align:start position:0% +this despite being a Harvard graduate + + + align:start position:0% +this despite being a Harvard graduate +but I would think what's most relevant + + align:start position:0% +but I would think what's most relevant + + + align:start position:0% +but I would think what's most relevant +about his political career is that also + + align:start position:0% +about his political career is that also + + + align:start position:0% +about his political career is that also +he's known as a progressive a term of + + align:start position:0% +he's known as a progressive a term of + + + align:start position:0% +he's known as a progressive a term of +essential Progressive suspicious of big + + align:start position:0% +essential Progressive suspicious of big + + + align:start position:0% +essential Progressive suspicious of big +corporations a trust Buster + + align:start position:0% +corporations a trust Buster + + + align:start position:0% +corporations a trust Buster +reform-minded in favor of clean and + + align:start position:0% +reform-minded in favor of clean and + + + align:start position:0% +reform-minded in favor of clean and +strong government action and + + align:start position:0% +strong government action and + + + align:start position:0% +strong government action and +intervention into the economy + + align:start position:0% +intervention into the economy + + + align:start position:0% +intervention into the economy +that's why it's become quite relevant + + align:start position:0% +that's why it's become quite relevant + + + align:start position:0% +that's why it's become quite relevant +the Roosevelt Institute is one of our + + align:start position:0% +the Roosevelt Institute is one of our + + + align:start position:0% +the Roosevelt Institute is one of our +most Progressive economic think tanks + + align:start position:0% +most Progressive economic think tanks + + + align:start position:0% +most Progressive economic think tanks +he's also for the purposes of our class + + align:start position:0% +he's also for the purposes of our class + + + align:start position:0% +he's also for the purposes of our class +known as a conservationist he's strongly + + align:start position:0% +known as a conservationist he's strongly + + + align:start position:0% +known as a conservationist he's strongly +associated with the U.S national Park + + align:start position:0% +associated with the U.S national Park + + + align:start position:0% +associated with the U.S national Park +system + + align:start position:0% +system + + + align:start position:0% +system +uh there's a quote from Wallace stegner + + align:start position:0% +uh there's a quote from Wallace stegner + + + align:start position:0% +uh there's a quote from Wallace stegner +a noted and honorable writer he called + + align:start position:0% +a noted and honorable writer he called + + + align:start position:0% +a noted and honorable writer he called +the national parks one of the best ideas + + align:start position:0% +the national parks one of the best ideas + + + align:start position:0% +the national parks one of the best ideas +we ever had absolutely American + + align:start position:0% +we ever had absolutely American + + + align:start position:0% +we ever had absolutely American +absolutely Democratic they reflect us at + + align:start position:0% +absolutely Democratic they reflect us at + + + align:start position:0% +absolutely Democratic they reflect us at +our best rather than our worst of course + + align:start position:0% +our best rather than our worst of course + + + align:start position:0% +our best rather than our worst of course +I put the asterisks on the national park + + align:start position:0% +I put the asterisks on the national park + + + align:start position:0% +I put the asterisks on the national park +system because as many people have noted + + align:start position:0% +system because as many people have noted + + + align:start position:0% +system because as many people have noted +throughout history and more recently a + + align:start position:0% +throughout history and more recently a + + + align:start position:0% +throughout history and more recently a +lot of the national park system is also + + align:start position:0% +lot of the national park system is also + + + align:start position:0% +lot of the national park system is also +land appropriated from indigenous + + align:start position:0% +land appropriated from indigenous + + + align:start position:0% +land appropriated from indigenous +peoples of the United States + + align:start position:0% +peoples of the United States + + + align:start position:0% +peoples of the United States +but also relevant for our discussion + + align:start position:0% +but also relevant for our discussion + + + align:start position:0% +but also relevant for our discussion +today Theodore Roosevelt has fairly + + align:start position:0% +today Theodore Roosevelt has fairly + + + align:start position:0% +today Theodore Roosevelt has fairly +troubling racial beliefs even for his + + align:start position:0% +troubling racial beliefs even for his + + + align:start position:0% +troubling racial beliefs even for his +time + + align:start position:0% +time + + + align:start position:0% +time +one could argue that he was in favor of + + align:start position:0% +one could argue that he was in favor of + + + align:start position:0% +one could argue that he was in favor of +immigration but also assimilation of + + align:start position:0% +immigration but also assimilation of + + + align:start position:0% +immigration but also assimilation of +immigrants into a strong American + + align:start position:0% +immigrants into a strong American + + + align:start position:0% +immigrants into a strong American +culture one could argue that he had + + align:start position:0% +culture one could argue that he had + + + align:start position:0% +culture one could argue that he had +Booker T Washington as a dinner guest at + + align:start position:0% +Booker T Washington as a dinner guest at + + + align:start position:0% +Booker T Washington as a dinner guest at +the White House which was considered + + align:start position:0% +the White House which was considered + + + align:start position:0% +the White House which was considered +quite controversial at the time one of + + align:start position:0% +quite controversial at the time one of + + + align:start position:0% +quite controversial at the time one of +the first presidents to entertain a + + align:start position:0% +the first presidents to entertain a + + + align:start position:0% +the first presidents to entertain a +black dinner guest at the White House + + align:start position:0% +black dinner guest at the White House + + + align:start position:0% +black dinner guest at the White House +halbora Keith also known for essentially + + align:start position:0% +halbora Keith also known for essentially + + + align:start position:0% +halbora Keith also known for essentially +advocating race war against Native + + align:start position:0% +advocating race war against Native + + + align:start position:0% +advocating race war against Native +Americans early in his career in his + + align:start position:0% +Americans early in his career in his + + + align:start position:0% +Americans early in his career in his +writings and also prosecuted a black + + align:start position:0% +writings and also prosecuted a black + + + align:start position:0% +writings and also prosecuted a black +regiment in Brownsville Texas for Mutiny + + align:start position:0% +regiment in Brownsville Texas for Mutiny + + + align:start position:0% +regiment in Brownsville Texas for Mutiny +quite unjustly according to the + + align:start position:0% +quite unjustly according to the + + + align:start position:0% +quite unjustly according to the +historical evidence so we have this kind + + align:start position:0% +historical evidence so we have this kind + + + align:start position:0% +historical evidence so we have this kind +of troubling history on one hand he's + + align:start position:0% +of troubling history on one hand he's + + + align:start position:0% +of troubling history on one hand he's +known as a conservationist he's one of + + align:start position:0% +known as a conservationist he's one of + + + align:start position:0% +known as a conservationist he's one of +our more scholarly presidents he writes + + align:start position:0% +our more scholarly presidents he writes + + + align:start position:0% +our more scholarly presidents he writes +about the environment writes about the + + align:start position:0% +about the environment writes about the + + + align:start position:0% +about the environment writes about the +need to conserve nature at the same time + + align:start position:0% +need to conserve nature at the same time + + + align:start position:0% +need to conserve nature at the same time +he also has these problem racial beliefs + + align:start position:0% +he also has these problem racial beliefs + + + align:start position:0% +he also has these problem racial beliefs +let me tell you another story about John + + align:start position:0% +let me tell you another story about John + + + align:start position:0% +let me tell you another story about John +Muir John Muir was born in Scotland in + + align:start position:0% +Muir John Muir was born in Scotland in + + + align:start position:0% +Muir John Muir was born in Scotland in +1838 he is an early naturalist writer + + align:start position:0% +1838 he is an early naturalist writer + + + align:start position:0% +1838 he is an early naturalist writer +early environmentalist he's considered + + align:start position:0% +early environmentalist he's considered + + + align:start position:0% +early environmentalist he's considered +one of the founding fathers of + + align:start position:0% +one of the founding fathers of + + + align:start position:0% +one of the founding fathers of +environmentalism because of a strong + + align:start position:0% +environmentalism because of a strong + + + align:start position:0% +environmentalism because of a strong +idea about human relationships in nature + + align:start position:0% +idea about human relationships in nature + + + align:start position:0% +idea about human relationships in nature +our impact on the earth and the + + align:start position:0% +our impact on the earth and the + + + align:start position:0% +our impact on the earth and the +preservation of the idea of wilderness + + align:start position:0% +preservation of the idea of wilderness + + + align:start position:0% +preservation of the idea of wilderness +he's also closely associated with the + + align:start position:0% +he's also closely associated with the + + + align:start position:0% +he's also closely associated with the +American West the founding of Yosemite + + align:start position:0% +American West the founding of Yosemite + + + align:start position:0% +American West the founding of Yosemite +Park and the founding of the Sierra Club + + align:start position:0% +Park and the founding of the Sierra Club + + + align:start position:0% +Park and the founding of the Sierra Club +many of his writings have the Sierra + + align:start position:0% +many of his writings have the Sierra + + + align:start position:0% +many of his writings have the Sierra +Nevados leading to the founding of the + + align:start position:0% +Nevados leading to the founding of the + + + align:start position:0% +Nevados leading to the founding of the +Sierra Club + + align:start position:0% +Sierra Club + + + align:start position:0% +Sierra Club +he also has recently noted we've also + + align:start position:0% +he also has recently noted we've also + + + align:start position:0% +he also has recently noted we've also +recently noted his troubling racial + + align:start position:0% +recently noted his troubling racial + + + align:start position:0% +recently noted his troubling racial +beliefs most notably in 2020 when the + + align:start position:0% +beliefs most notably in 2020 when the + + + align:start position:0% +beliefs most notably in 2020 when the +executive director of the Sierra Club + + align:start position:0% +executive director of the Sierra Club + + + align:start position:0% +executive director of the Sierra Club +Michael brune apologized for his racial + + align:start position:0% +Michael brune apologized for his racial + + + align:start position:0% +Michael brune apologized for his racial +beliefs and racial writings he writes + + align:start position:0% +beliefs and racial writings he writes + + + align:start position:0% +beliefs and racial writings he writes +early on his career about Native + + align:start position:0% +early on his career about Native + + + align:start position:0% +early on his career about Native +Americans and blacks as lady + + align:start position:0% +Americans and blacks as lady + + + align:start position:0% +Americans and blacks as lady +at the same time later on this other + + align:start position:0% +at the same time later on this other + + + align:start position:0% +at the same time later on this other +Scholars note that he writes about + + align:start position:0% +Scholars note that he writes about + + + align:start position:0% +Scholars note that he writes about +approvingly of Native American culture + + align:start position:0% +approvingly of Native American culture + + + align:start position:0% +approvingly of Native American culture +as having much less impact on the earth + + align:start position:0% +as having much less impact on the earth + + + align:start position:0% +as having much less impact on the earth +other Scholars have noted that his idea + + align:start position:0% +other Scholars have noted that his idea + + + align:start position:0% +other Scholars have noted that his idea +of wilderness essentially assumes a + + align:start position:0% +of wilderness essentially assumes a + + + align:start position:0% +of wilderness essentially assumes a +pristine Wilderness in the absence of + + align:start position:0% +pristine Wilderness in the absence of + + + align:start position:0% +pristine Wilderness in the absence of +people ignoring the presence of + + align:start position:0% +people ignoring the presence of + + + align:start position:0% +people ignoring the presence of +indigenous peoples and cultures and so + + align:start position:0% +indigenous peoples and cultures and so + + + align:start position:0% +indigenous peoples and cultures and so +what I want to do by kind of just + + align:start position:0% +what I want to do by kind of just + + + align:start position:0% +what I want to do by kind of just +talking about his biographies a little + + align:start position:0% +talking about his biographies a little + + + align:start position:0% +talking about his biographies a little +bit is explore the idea of what is + + align:start position:0% +bit is explore the idea of what is + + + align:start position:0% +bit is explore the idea of what is +Justice going to be in a climate context + + align:start position:0% +Justice going to be in a climate context + + + align:start position:0% +Justice going to be in a climate context +do his racial writings matter or does + + align:start position:0% +do his racial writings matter or does + + + align:start position:0% +do his racial writings matter or does +his idea of wilderness and preservation + + align:start position:0% +his idea of wilderness and preservation + + + align:start position:0% +his idea of wilderness and preservation +of wilderness also matter how do they + + align:start position:0% +of wilderness also matter how do they + + + align:start position:0% +of wilderness also matter how do they +matter that's something we're going to + + align:start position:0% +matter that's something we're going to + + + align:start position:0% +matter that's something we're going to +discuss in class + + align:start position:0% +discuss in class + + + align:start position:0% +discuss in class +just to take one more example Frederick + + align:start position:0% +just to take one more example Frederick + + + align:start position:0% +just to take one more example Frederick +Law Olmsted Jr is a noted journalist + + align:start position:0% +Law Olmsted Jr is a noted journalist + + + align:start position:0% +Law Olmsted Jr is a noted journalist +writer farmer and abolitionist a + + align:start position:0% +writer farmer and abolitionist a + + + align:start position:0% +writer farmer and abolitionist a +well-known first writings before he + + align:start position:0% +well-known first writings before he + + + align:start position:0% +well-known first writings before he +becomes a landscape architect but as a + + align:start position:0% +becomes a landscape architect but as a + + + align:start position:0% +becomes a landscape architect but as a +landscape architect he's fairly prolific + + align:start position:0% +landscape architect he's fairly prolific + + + align:start position:0% +landscape architect he's fairly prolific +here in Boston he built the Boston + + align:start position:0% +here in Boston he built the Boston + + + align:start position:0% +here in Boston he built the Boston +Common the public garden the emerald + + align:start position:0% +Common the public garden the emerald + + + align:start position:0% +Common the public garden the emerald +necklace and the fence + + align:start position:0% +necklace and the fence + + + align:start position:0% +necklace and the fence +in New York he builds a prospects park + + align:start position:0% +in New York he builds a prospects park + + + align:start position:0% +in New York he builds a prospects park +in Brooklyn Belle Isle Park in the + + align:start position:0% +in Brooklyn Belle Isle Park in the + + + align:start position:0% +in Brooklyn Belle Isle Park in the +Detroit River the Biltmore Estate in + + align:start position:0% +Detroit River the Biltmore Estate in + + + align:start position:0% +Detroit River the Biltmore Estate in +North Carolina and also designs the U.S + + align:start position:0% +North Carolina and also designs the U.S + + + align:start position:0% +North Carolina and also designs the U.S +Capitol grounds more recently however + + align:start position:0% +Capitol grounds more recently however + + + align:start position:0% +Capitol grounds more recently however +there's been controversy not so much + + align:start position:0% +there's been controversy not so much + + + align:start position:0% +there's been controversy not so much +about his role but about his most noted + + align:start position:0% +about his role but about his most noted + + + align:start position:0% +about his role but about his most noted +perhaps work Central Park Central Park + + align:start position:0% +perhaps work Central Park Central Park + + + align:start position:0% +perhaps work Central Park Central Park +at the time was well north of the city + + align:start position:0% +at the time was well north of the city + + + align:start position:0% +at the time was well north of the city +so actually almost outside of New York + + align:start position:0% +so actually almost outside of New York + + + align:start position:0% +so actually almost outside of New York +City which is I think largely below 34th + + align:start position:0% +City which is I think largely below 34th + + + align:start position:0% +City which is I think largely below 34th +Street + + align:start position:0% +Street + + + align:start position:0% +Street +and at the time New York state + + align:start position:0% +and at the time New York state + + + align:start position:0% +and at the time New York state +legislators basically looked at it as + + align:start position:0% +legislators basically looked at it as + + + align:start position:0% +legislators basically looked at it as +700 Acres of not particularly desirable + + align:start position:0% +700 Acres of not particularly desirable + + + align:start position:0% +700 Acres of not particularly desirable +landscape + + align:start position:0% +landscape + + + align:start position:0% +landscape +Frederick Law Olmstead and his partner + + align:start position:0% +Frederick Law Olmstead and his partner + + + align:start position:0% +Frederick Law Olmstead and his partner +Calvert Beau are well known for our + + align:start position:0% +Calvert Beau are well known for our + + + align:start position:0% +Calvert Beau are well known for our +transforming Central Park into what we + + align:start position:0% +transforming Central Park into what we + + + align:start position:0% +transforming Central Park into what we +know it as today the design has largely + + align:start position:0% +know it as today the design has largely + + + align:start position:0% +know it as today the design has largely +preserved and they build Central Park + + align:start position:0% +preserved and they build Central Park + + + align:start position:0% +preserved and they build Central Park +and they write about Prospect Park as a + + align:start position:0% +and they write about Prospect Park as a + + + align:start position:0% +and they write about Prospect Park as a +open-air area for immigrants and people + + align:start position:0% +open-air area for immigrants and people + + + align:start position:0% +open-air area for immigrants and people +from all backgrounds to mix so they have + + align:start position:0% +from all backgrounds to mix so they have + + + align:start position:0% +from all backgrounds to mix so they have +essentially they have an essentially + + align:start position:0% +essentially they have an essentially + + + align:start position:0% +essentially they have an essentially +Democratic vision of what these parks + + align:start position:0% +Democratic vision of what these parks + + + align:start position:0% +Democratic vision of what these parks +are meant to do in a bustling turn of + + align:start position:0% +are meant to do in a bustling turn of + + + align:start position:0% +are meant to do in a bustling turn of +the century rapidly changing New York + + align:start position:0% +the century rapidly changing New York + + + align:start position:0% +the century rapidly changing New York +City of course more recently Landscape + + align:start position:0% +City of course more recently Landscape + + + align:start position:0% +City of course more recently Landscape +Architects and historians have Unearthed + + align:start position:0% +Architects and historians have Unearthed + + + align:start position:0% +Architects and historians have Unearthed +or noted these presence that it was not + + align:start position:0% +or noted these presence that it was not + + + align:start position:0% +or noted these presence that it was not +actually a Barren landscape as the New + + align:start position:0% +actually a Barren landscape as the New + + + align:start position:0% +actually a Barren landscape as the New +York state legislator wrote about it + + align:start position:0% +York state legislator wrote about it + + + align:start position:0% +York state legislator wrote about it +there were actually several small + + align:start position:0% +there were actually several small + + + align:start position:0% +there were actually several small +villages notably Seneca Village one of + + align:start position:0% +villages notably Seneca Village one of + + + align:start position:0% +villages notably Seneca Village one of +the few middle class black communities + + align:start position:0% +the few middle class black communities + + + align:start position:0% +the few middle class black communities +in New York City apparently it also had + + align:start position:0% +in New York City apparently it also had + + + align:start position:0% +in New York City apparently it also had +German and Irish immigrants but by + + align:start position:0% +German and Irish immigrants but by + + + align:start position:0% +German and Irish immigrants but by +eminent domain the city or the state + + align:start position:0% +eminent domain the city or the state + + + align:start position:0% +eminent domain the city or the state +claims the landscape of Central Park and + + align:start position:0% +claims the landscape of Central Park and + + + align:start position:0% +claims the landscape of Central Park and +essentially raises Seneca Village so + + align:start position:0% +essentially raises Seneca Village so + + + align:start position:0% +essentially raises Seneca Village so +there's a lot more historical writing + + align:start position:0% +there's a lot more historical writing + + + align:start position:0% +there's a lot more historical writing +about Seneca Village recently and the + + align:start position:0% +about Seneca Village recently and the + + + align:start position:0% +about Seneca Village recently and the +question is does this change the legacy + + align:start position:0% +question is does this change the legacy + + + align:start position:0% +question is does this change the legacy +of Frederick Law Olmstead or should we + + align:start position:0% +of Frederick Law Olmstead or should we + + + align:start position:0% +of Frederick Law Olmstead or should we +talk about his Works in a different way + + align:start position:0% +talk about his Works in a different way + + + align:start position:0% +talk about his Works in a different way +and this brings me to uh The Last Story + + align:start position:0% +and this brings me to uh The Last Story + + + align:start position:0% +and this brings me to uh The Last Story +I want to tell you it's about Professor + + align:start position:0% +I want to tell you it's about Professor + + + align:start position:0% +I want to tell you it's about Professor +Robert Bullard considered one of the + + align:start position:0% +Robert Bullard considered one of the + + + align:start position:0% +Robert Bullard considered one of the +leading Scholars on environmental racism + + align:start position:0% +leading Scholars on environmental racism + + + align:start position:0% +leading Scholars on environmental racism +and viral Justice and I think it's just + + align:start position:0% +and viral Justice and I think it's just + + + align:start position:0% +and viral Justice and I think it's just +a good story of how peace gets involved + + align:start position:0% +a good story of how peace gets involved + + + align:start position:0% +a good story of how peace gets involved +in this topic and how he + + align:start position:0% +in this topic and how he + + + align:start position:0% +in this topic and how he +continues to write about these issues + + align:start position:0% +continues to write about these issues + + + align:start position:0% +continues to write about these issues +today there's a 2012 portrait on the + + align:start position:0% +today there's a 2012 portrait on the + + + align:start position:0% +today there's a 2012 portrait on the +left this is a small excerpt on the + + align:start position:0% +left this is a small excerpt on the + + + align:start position:0% +left this is a small excerpt on the +right it's a list of a summary of + + align:start position:0% +right it's a list of a summary of + + + align:start position:0% +right it's a list of a summary of +community disputes for one of his + + align:start position:0% +community disputes for one of his + + + align:start position:0% +community disputes for one of his +earliest writings on environmental + + align:start position:0% +earliest writings on environmental + + + align:start position:0% +earliest writings on environmental +racism + + align:start position:0% +racism + + + align:start position:0% +racism +and essentially lists Grassroots + + align:start position:0% +and essentially lists Grassroots + + + align:start position:0% +and essentially lists Grassroots +movements and throughout the South but + + align:start position:0% +movements and throughout the South but + + + align:start position:0% +movements and throughout the South but +also the American West where communities + + align:start position:0% +also the American West where communities + + + align:start position:0% +also the American West where communities +and neighborhoods are trying to fight + + align:start position:0% +and neighborhoods are trying to fight + + + align:start position:0% +and neighborhoods are trying to fight +back against environmental + + align:start position:0% +back against environmental + + + align:start position:0% +back against environmental +infrastructure that'll be located in + + align:start position:0% +infrastructure that'll be located in + + + align:start position:0% +infrastructure that'll be located in +neighborhoods environmental + + align:start position:0% +neighborhoods environmental + + + align:start position:0% +neighborhoods environmental +infrastructure like landfills smelters + + align:start position:0% +infrastructure like landfills smelters + + + align:start position:0% +infrastructure like landfills smelters +houses waste incinerators petrochemical + + align:start position:0% +houses waste incinerators petrochemical + + + align:start position:0% +houses waste incinerators petrochemical +or binaries that we know will probably + + align:start position:0% +or binaries that we know will probably + + + align:start position:0% +or binaries that we know will probably +have negative environmental or health + + align:start position:0% +have negative environmental or health + + + align:start position:0% +have negative environmental or health +effects on the residents + + align:start position:0% +effects on the residents + + + align:start position:0% +effects on the residents +his wife at the time is a lawyer or his + + align:start position:0% +his wife at the time is a lawyer or his + + + align:start position:0% +his wife at the time is a lawyer or his +wife is a lawyer and at the time she's + + align:start position:0% +wife is a lawyer and at the time she's + + + align:start position:0% +wife is a lawyer and at the time she's +involved in litigation against this + + align:start position:0% +involved in litigation against this + + + align:start position:0% +involved in litigation against this +landfill she asked him to get involved + + align:start position:0% +landfill she asked him to get involved + + + align:start position:0% +landfill she asked him to get involved +in the lawsuit as an expert witness and + + align:start position:0% +in the lawsuit as an expert witness and + + + align:start position:0% +in the lawsuit as an expert witness and +to do research on where landfills are + + align:start position:0% +to do research on where landfills are + + + align:start position:0% +to do research on where landfills are +located he finds that 100 of landfills + + align:start position:0% +located he finds that 100 of landfills + + + align:start position:0% +located he finds that 100 of landfills +in Houston are actually located in black + + align:start position:0% +in Houston are actually located in black + + + align:start position:0% +in Houston are actually located in black +neighborhoods even though only 25 + + align:start position:0% +neighborhoods even though only 25 + + + align:start position:0% +neighborhoods even though only 25 +percent of the population of Houston is + + align:start position:0% +percent of the population of Houston is + + + align:start position:0% +percent of the population of Houston is +black and so he essentially identifies + + align:start position:0% +black and so he essentially identifies + + + align:start position:0% +black and so he essentially identifies +this as a racial phenomenon that these + + align:start position:0% +this as a racial phenomenon that these + + + align:start position:0% +this as a racial phenomenon that these +infrastructures are being located in + + align:start position:0% +infrastructures are being located in + + + align:start position:0% +infrastructures are being located in +Black communities and he starts writing + + align:start position:0% +Black communities and he starts writing + + + align:start position:0% +Black communities and he starts writing +about it + + align:start position:0% +about it + + + align:start position:0% +about it +and so this is a good example or I think + + align:start position:0% +and so this is a good example or I think + + + align:start position:0% +and so this is a good example or I think +all of these stories are good examples + + align:start position:0% +all of these stories are good examples + + + align:start position:0% +all of these stories are good examples +of how we have have to discuss race and + + align:start position:0% +of how we have have to discuss race and + + + align:start position:0% +of how we have have to discuss race and +Justice in environmental context the + + align:start position:0% +Justice in environmental context the + + + align:start position:0% +Justice in environmental context the +1960s and 70s are noted for the + + align:start position:0% +1960s and 70s are noted for the + + + align:start position:0% +1960s and 70s are noted for the +environmental and civil rights movements + + align:start position:0% +environmental and civil rights movements + + + align:start position:0% +environmental and civil rights movements +these civil rights movements obviously + + align:start position:0% +these civil rights movements obviously + + + align:start position:0% +these civil rights movements obviously +typified by the civil rights leaders + + align:start position:0% +typified by the civil rights leaders + + + align:start position:0% +typified by the civil rights leaders +like Martin Luther King Jr or Malcolm X + + align:start position:0% +like Martin Luther King Jr or Malcolm X + + + align:start position:0% +like Martin Luther King Jr or Malcolm X +or Sophie Carmichael and at the same + + align:start position:0% +or Sophie Carmichael and at the same + + + align:start position:0% +or Sophie Carmichael and at the same +time we have the environmental movement + + align:start position:0% +time we have the environmental movement + + + align:start position:0% +time we have the environmental movement +culminating in the Clean Air and clean + + align:start position:0% +culminating in the Clean Air and clean + + + align:start position:0% +culminating in the Clean Air and clean +water acts in the 1970s + + align:start position:0% +water acts in the 1970s + + + align:start position:0% +water acts in the 1970s +these two movements are largely separate + + align:start position:0% +these two movements are largely separate + + + align:start position:0% +these two movements are largely separate +typified by different people and + + align:start position:0% +typified by different people and + + + align:start position:0% +typified by different people and +different leaders + + align:start position:0% +different leaders + + + align:start position:0% +different leaders +and different groups + + align:start position:0% +and different groups + + + align:start position:0% +and different groups +of course there are kind of nascent + + align:start position:0% +of course there are kind of nascent + + + align:start position:0% +of course there are kind of nascent +linkages between some of these issues + + align:start position:0% +linkages between some of these issues + + + align:start position:0% +linkages between some of these issues +the United Church of Christ Commission + + align:start position:0% +the United Church of Christ Commission + + + align:start position:0% +the United Church of Christ Commission +on racial justice issues are reported + + align:start position:0% +on racial justice issues are reported + + + align:start position:0% +on racial justice issues are reported +1987 called toxic waste and race in the + + align:start position:0% +1987 called toxic waste and race in the + + + align:start position:0% +1987 called toxic waste and race in the +United States + + align:start position:0% +United States + + + align:start position:0% +United States +Robert Bullard starts writing about it + + align:start position:0% +Robert Bullard starts writing about it + + + align:start position:0% +Robert Bullard starts writing about it +or after this expert witness testimony + + align:start position:0% +or after this expert witness testimony + + + align:start position:0% +or after this expert witness testimony +in his wife's lawsuit he writes dumping + + align:start position:0% +in his wife's lawsuit he writes dumping + + + align:start position:0% +in his wife's lawsuit he writes dumping +in Dixie in 1990 arguing for convergence + + align:start position:0% +in Dixie in 1990 arguing for convergence + + + align:start position:0% +in Dixie in 1990 arguing for convergence +between the Civil Rights and + + align:start position:0% +between the Civil Rights and + + + align:start position:0% +between the Civil Rights and +environmental movements and he writes + + align:start position:0% +environmental movements and he writes + + + align:start position:0% +environmental movements and he writes +about environmental justice and racism + + align:start position:0% +about environmental justice and racism + + + align:start position:0% +about environmental justice and racism +using very similar terms that we now + + align:start position:0% +using very similar terms that we now + + + align:start position:0% +using very similar terms that we now +think about those things today it's also + + align:start position:0% +think about those things today it's also + + + align:start position:0% +think about those things today it's also +really interesting in these writings how + + align:start position:0% +really interesting in these writings how + + + align:start position:0% +really interesting in these writings how +he writes very clearly that racism plays + + align:start position:0% +he writes very clearly that racism plays + + + align:start position:0% +he writes very clearly that racism plays +a key factor in environmental planning + + align:start position:0% +a key factor in environmental planning + + + align:start position:0% +a key factor in environmental planning +and decision making + + align:start position:0% +and decision making + + + align:start position:0% +and decision making +and what's really striking about his + + align:start position:0% +and what's really striking about his + + + align:start position:0% +and what's really striking about his +writing is that it's a very clear + + align:start position:0% +writing is that it's a very clear + + + align:start position:0% +writing is that it's a very clear +critique of the mainstream environmental + + align:start position:0% +critique of the mainstream environmental + + + align:start position:0% +critique of the mainstream environmental +movement which is separate than the + + align:start position:0% +movement which is separate than the + + + align:start position:0% +movement which is separate than the +Civil Rights Movement he writes it is a + + align:start position:0% +Civil Rights Movement he writes it is a + + + align:start position:0% +Civil Rights Movement he writes it is a +fact of life in the United States that + + align:start position:0% +fact of life in the United States that + + + align:start position:0% +fact of life in the United States that +the mainstream environmental movement is + + align:start position:0% +the mainstream environmental movement is + + + align:start position:0% +the mainstream environmental movement is +only beginning to wake up to the fact of + + align:start position:0% +only beginning to wake up to the fact of + + + align:start position:0% +only beginning to wake up to the fact of +life being racism + + align:start position:0% +life being racism + + + align:start position:0% +life being racism +but just the same year the EPA issues a + + align:start position:0% +but just the same year the EPA issues a + + + align:start position:0% +but just the same year the EPA issues a +report called environmental Equity + + align:start position:0% +report called environmental Equity + + + align:start position:0% +report called environmental Equity +reducing risk for all communities + + align:start position:0% +reducing risk for all communities + + + align:start position:0% +reducing risk for all communities +they very self-consciously choose the + + align:start position:0% +they very self-consciously choose the + + + align:start position:0% +they very self-consciously choose the +phrase environmental equity and they put + + align:start position:0% +phrase environmental equity and they put + + + align:start position:0% +phrase environmental equity and they put +in terms of reducing risk for all + + align:start position:0% +in terms of reducing risk for all + + + align:start position:0% +in terms of reducing risk for all +communities they say in the introduction + + align:start position:0% +communities they say in the introduction + + + align:start position:0% +communities they say in the introduction +that environmental Equity is to study or + + align:start position:0% +that environmental Equity is to study or + + + align:start position:0% +that environmental Equity is to study or +to identify the distribution and effects + + align:start position:0% +to identify the distribution and effects + + + align:start position:0% +to identify the distribution and effects +of environmental problems and the + + align:start position:0% +of environmental problems and the + + + align:start position:0% +of environmental problems and the +policies and processes to reduce + + align:start position:0% +policies and processes to reduce + + + align:start position:0% +policies and processes to reduce +differences in who Bears environmental + + align:start position:0% +differences in who Bears environmental + + + align:start position:0% +differences in who Bears environmental +risks + + align:start position:0% +risks + + + align:start position:0% +risks +and in just the next year the U.S + + align:start position:0% +and in just the next year the U.S + + + align:start position:0% +and in just the next year the U.S +President Bill Clinton issued an + + align:start position:0% +President Bill Clinton issued an + + + align:start position:0% +President Bill Clinton issued an +executive order in 1994 titled Federal + + align:start position:0% +executive order in 1994 titled Federal + + + align:start position:0% +executive order in 1994 titled Federal +actions to address environmental justice + + align:start position:0% +actions to address environmental justice + + + align:start position:0% +actions to address environmental justice +and minority populations and low-income + + align:start position:0% +and minority populations and low-income + + + align:start position:0% +and minority populations and low-income +populations so even in this seven year + + align:start position:0% +populations so even in this seven year + + + align:start position:0% +populations so even in this seven year +period or so in these writings you see + + align:start position:0% +period or so in these writings you see + + + align:start position:0% +period or so in these writings you see +the idea of environmental justice + + align:start position:0% +the idea of environmental justice + + + align:start position:0% +the idea of environmental justice +essentially becoming fully normalized of + + align:start position:0% +essentially becoming fully normalized of + + + align:start position:0% +essentially becoming fully normalized of +course we still have to understand what + + align:start position:0% +course we still have to understand what + + + align:start position:0% +course we still have to understand what +it means + + align:start position:0% +it means + + + align:start position:0% +it means +of course it's also worth pointing out + + align:start position:0% +of course it's also worth pointing out + + + align:start position:0% +of course it's also worth pointing out +that environmentalists are the + + align:start position:0% +that environmentalists are the + + + align:start position:0% +that environmentalists are the +mainstream environmental movement as + + align:start position:0% +mainstream environmental movement as + + + align:start position:0% +mainstream environmental movement as +Robert Bullard calls it is still quite + + align:start position:0% +Robert Bullard calls it is still quite + + + align:start position:0% +Robert Bullard calls it is still quite +separate from the environmental justice + + align:start position:0% +separate from the environmental justice + + + align:start position:0% +separate from the environmental justice +movement here's a headline a very + + align:start position:0% +movement here's a headline a very + + + align:start position:0% +movement here's a headline a very +typical in 2020 about green groups that + + align:start position:0% +typical in 2020 about green groups that + + + align:start position:0% +typical in 2020 about green groups that +are grappling with a history of racism + + align:start position:0% +are grappling with a history of racism + + + align:start position:0% +are grappling with a history of racism +and exclusion + + align:start position:0% +and exclusion + + + align:start position:0% +and exclusion +the environmental movement in America + + align:start position:0% +the environmental movement in America + + + align:start position:0% +the environmental movement in America +has deep ties to the nation's history of + + align:start position:0% +has deep ties to the nation's history of + + + align:start position:0% +has deep ties to the nation's history of +systemic racism and white supremacy this + + align:start position:0% +systemic racism and white supremacy this + + + align:start position:0% +systemic racism and white supremacy this +article writes now as Americans confront + + align:start position:0% +article writes now as Americans confront + + + align:start position:0% +article writes now as Americans confront +racial Injustice Anew powerful Green + + align:start position:0% +racial Injustice Anew powerful Green + + + align:start position:0% +racial Injustice Anew powerful Green +groups like the Sierra Club are + + align:start position:0% +groups like the Sierra Club are + + + align:start position:0% +groups like the Sierra Club are +beginning to reckon with their own + + align:start position:0% +beginning to reckon with their own + + + align:start position:0% +beginning to reckon with their own +histories of hate and exclusion and so + + align:start position:0% +histories of hate and exclusion and so + + + align:start position:0% +histories of hate and exclusion and so +there's significant controversy within + + align:start position:0% +there's significant controversy within + + + align:start position:0% +there's significant controversy within +the Sierra Club itself Sierra Club also + + align:start position:0% +the Sierra Club itself Sierra Club also + + + align:start position:0% +the Sierra Club itself Sierra Club also +closely associated with the idea of + + align:start position:0% +closely associated with the idea of + + + align:start position:0% +closely associated with the idea of +conservation the executive director + + align:start position:0% +conservation the executive director + + + align:start position:0% +conservation the executive director +apologized for John Muir's writings + + align:start position:0% +apologized for John Muir's writings + + + align:start position:0% +apologized for John Muir's writings +about black people and Native Americans + + align:start position:0% +about black people and Native Americans + + + align:start position:0% +about black people and Native Americans +other board members disagreed and argued + + align:start position:0% +other board members disagreed and argued + + + align:start position:0% +other board members disagreed and argued +that the Sierra Club has a strong Legacy + + align:start position:0% +that the Sierra Club has a strong Legacy + + + align:start position:0% +that the Sierra Club has a strong Legacy +of conservation of course the question + + align:start position:0% +of conservation of course the question + + + align:start position:0% +of conservation of course the question +is conservation for who and what's more + + align:start position:0% +is conservation for who and what's more + + + align:start position:0% +is conservation for who and what's more +interesting about the article I + + align:start position:0% +interesting about the article I + + + align:start position:0% +interesting about the article I +encourage you to either listen to it at + + align:start position:0% +encourage you to either listen to it at + + + align:start position:0% +encourage you to either listen to it at +the radio segment or read it is that + + align:start position:0% +the radio segment or read it is that + + + align:start position:0% +the radio segment or read it is that +a reporter from Milwaukee Washington + + align:start position:0% +a reporter from Milwaukee Washington + + + align:start position:0% +a reporter from Milwaukee Washington +Post Daryl fears I started writing about + + align:start position:0% +Post Daryl fears I started writing about + + + align:start position:0% +Post Daryl fears I started writing about +green groups and their lack of diversity + + align:start position:0% +green groups and their lack of diversity + + + align:start position:0% +green groups and their lack of diversity +many years before he said that if you go + + align:start position:0% +many years before he said that if you go + + + align:start position:0% +many years before he said that if you go +to many environmental meetings and + + align:start position:0% +to many environmental meetings and + + + align:start position:0% +to many environmental meetings and +basically essentially see no other black + + align:start position:0% +basically essentially see no other black + + + align:start position:0% +basically essentially see no other black +people there and so he started writing + + align:start position:0% +people there and so he started writing + + + align:start position:0% +people there and so he started writing +about the homogeneity of the + + align:start position:0% +about the homogeneity of the + + + align:start position:0% +about the homogeneity of the +environmental movement then and so + + align:start position:0% +environmental movement then and so + + + align:start position:0% +environmental movement then and so +environmental justice movements are much + + align:start position:0% +environmental justice movements are much + + + align:start position:0% +environmental justice movements are much +more closely associated with Grassroots + + align:start position:0% +more closely associated with Grassroots + + + align:start position:0% +more closely associated with Grassroots +movements and Community groups and the + + align:start position:0% +movements and Community groups and the + + + align:start position:0% +movements and Community groups and the +question is how do we perhaps hopefully + + align:start position:0% +question is how do we perhaps hopefully + + + align:start position:0% +question is how do we perhaps hopefully +bring these two movements together into + + align:start position:0% +bring these two movements together into + + + align:start position:0% +bring these two movements together into +a coalition + + align:start position:0% +a coalition + + + align:start position:0% +a coalition +and so this has spawned many different + + align:start position:0% +and so this has spawned many different + + + align:start position:0% +and so this has spawned many different +kind of conceptions and I would argue to + + align:start position:0% +kind of conceptions and I would argue to + + + align:start position:0% +kind of conceptions and I would argue to +you that our ideas about Justice + + align:start position:0% +you that our ideas about Justice + + + align:start position:0% +you that our ideas about Justice +fairness and equity which are not + + align:start position:0% +fairness and equity which are not + + + align:start position:0% +fairness and equity which are not +necessarily the same but often used + + align:start position:0% +necessarily the same but often used + + + align:start position:0% +necessarily the same but often used +quite interchangeably have become + + align:start position:0% +quite interchangeably have become + + + align:start position:0% +quite interchangeably have become +crossed with energy and climate and this + + align:start position:0% +crossed with energy and climate and this + + + align:start position:0% +crossed with energy and climate and this +is the key thing we want to discuss in + + align:start position:0% +is the key thing we want to discuss in + + + align:start position:0% +is the key thing we want to discuss in +class + + align:start position:0% +class + + + align:start position:0% +class +uh for example climate justice has roots + + align:start position:0% +uh for example climate justice has roots + + + align:start position:0% +uh for example climate justice has roots +in ideas about historical responsibility + + align:start position:0% +in ideas about historical responsibility + + + align:start position:0% +in ideas about historical responsibility +and intergenerational Equity we would + + align:start position:0% +and intergenerational Equity we would + + + align:start position:0% +and intergenerational Equity we would +talk about historical responsibility and + + align:start position:0% +talk about historical responsibility and + + + align:start position:0% +talk about historical responsibility and +generational Equity as uh in terms of + + align:start position:0% +generational Equity as uh in terms of + + + align:start position:0% +generational Equity as uh in terms of +climate change as a problem that older + + align:start position:0% +climate change as a problem that older + + + align:start position:0% +climate change as a problem that older +Generations may be leaving for later or + + align:start position:0% +Generations may be leaving for later or + + + align:start position:0% +Generations may be leaving for later or +following Generations it is interesting + + align:start position:0% +following Generations it is interesting + + + align:start position:0% +following Generations it is interesting +to see how that rhetoric has perhaps + + align:start position:0% +to see how that rhetoric has perhaps + + + align:start position:0% +to see how that rhetoric has perhaps +diminished because climate change is + + align:start position:0% +diminished because climate change is + + + align:start position:0% +diminished because climate change is +here now we all know that climate change + + align:start position:0% +here now we all know that climate change + + + align:start position:0% +here now we all know that climate change +is happening it may not no longer be + + align:start position:0% +is happening it may not no longer be + + + align:start position:0% +is happening it may not no longer be +intergenerational problem it is a + + align:start position:0% +intergenerational problem it is a + + + align:start position:0% +intergenerational problem it is a +problem here and now and so I think a + + align:start position:0% +problem here and now and so I think a + + + align:start position:0% +problem here and now and so I think a +more modern I guess way to talk about + + align:start position:0% +more modern I guess way to talk about + + + align:start position:0% +more modern I guess way to talk about +climate justice has been about as + + align:start position:0% +climate justice has been about as + + + align:start position:0% +climate justice has been about as +disproportionate causes and burdens not + + align:start position:0% +disproportionate causes and burdens not + + + align:start position:0% +disproportionate causes and burdens not +only are older Generations causing + + align:start position:0% +only are older Generations causing + + + align:start position:0% +only are older Generations causing +greenhouse gas emissions that will + + align:start position:0% +greenhouse gas emissions that will + + + align:start position:0% +greenhouse gas emissions that will +affect future Generations in terms of + + align:start position:0% +affect future Generations in terms of + + + align:start position:0% +affect future Generations in terms of +climate change we also know that rich + + align:start position:0% +climate change we also know that rich + + + align:start position:0% +climate change we also know that rich +western or developed countries have + + align:start position:0% +western or developed countries have + + + align:start position:0% +western or developed countries have +disproportionately caused the problem + + align:start position:0% +disproportionately caused the problem + + + align:start position:0% +disproportionately caused the problem +this is an argument I've made to you + + align:start position:0% +this is an argument I've made to you + + + align:start position:0% +this is an argument I've made to you +before and that those burdens have been + + align:start position:0% +before and that those burdens have been + + + align:start position:0% +before and that those burdens have been +modeled or forecast to disruportionately + + align:start position:0% +modeled or forecast to disruportionately + + + align:start position:0% +modeled or forecast to disruportionately +affect the countries that are least + + align:start position:0% +affect the countries that are least + + + align:start position:0% +affect the countries that are least +responsible for causing climate change + + align:start position:0% +responsible for causing climate change + + + align:start position:0% +responsible for causing climate change +like the flooding happening in Pakistan + + align:start position:0% +like the flooding happening in Pakistan + + + align:start position:0% +like the flooding happening in Pakistan +like hurricanes and typhoons hitting + + align:start position:0% +like hurricanes and typhoons hitting + + + align:start position:0% +like hurricanes and typhoons hitting +Mozambique + + align:start position:0% +Mozambique + + + align:start position:0% +Mozambique +at the same time climate justice has + + align:start position:0% +at the same time climate justice has + + + align:start position:0% +at the same time climate justice has +become a more important phrase or idea + + align:start position:0% +become a more important phrase or idea + + + align:start position:0% +become a more important phrase or idea +because of the rise of Grassroots + + align:start position:0% +because of the rise of Grassroots + + + align:start position:0% +because of the rise of Grassroots +movements like Friday after the future + + align:start position:0% +movements like Friday after the future + + + align:start position:0% +movements like Friday after the future +or Extinction Rebellion when you have a + + align:start position:0% +or Extinction Rebellion when you have a + + + align:start position:0% +or Extinction Rebellion when you have a +social movement you need to have a set + + align:start position:0% +social movement you need to have a set + + + align:start position:0% +social movement you need to have a set +of organizing principles or ideas + + align:start position:0% +of organizing principles or ideas + + + align:start position:0% +of organizing principles or ideas +climate justice has become one of those + + align:start position:0% +climate justice has become one of those + + + align:start position:0% +climate justice has become one of those +important ideas + + align:start position:0% +important ideas + + + align:start position:0% +important ideas +and of course climate justice has become + + align:start position:0% +and of course climate justice has become + + + align:start position:0% +and of course climate justice has become +a more important idea because of legal + + align:start position:0% +a more important idea because of legal + + + align:start position:0% +a more important idea because of legal +actions on climate change I think the + + align:start position:0% +actions on climate change I think the + + + align:start position:0% +actions on climate change I think the +United Nations counted recently almost + + align:start position:0% +United Nations counted recently almost + + + align:start position:0% +United Nations counted recently almost +900 legal actions on climate change a + + align:start position:0% +900 legal actions on climate change a + + + align:start position:0% +900 legal actions on climate change a +lot of those adjudication of litigation + + align:start position:0% +lot of those adjudication of litigation + + + align:start position:0% +lot of those adjudication of litigation +around the effects of climate change are + + align:start position:0% +around the effects of climate change are + + + align:start position:0% +around the effects of climate change are +trying to get to an idea of who is + + align:start position:0% +trying to get to an idea of who is + + + align:start position:0% +trying to get to an idea of who is +responsible for climate change how can + + align:start position:0% +responsible for climate change how can + + + align:start position:0% +responsible for climate change how can +let's say different countries or groups + + align:start position:0% +let's say different countries or groups + + + align:start position:0% +let's say different countries or groups +or corporations be held responsible for + + align:start position:0% +or corporations be held responsible for + + + align:start position:0% +or corporations be held responsible for +the impacts of climate change do they + + align:start position:0% +the impacts of climate change do they + + + align:start position:0% +the impacts of climate change do they +owe reparations or remedies to affected + + align:start position:0% +owe reparations or remedies to affected + + + align:start position:0% +owe reparations or remedies to affected +groups + + align:start position:0% +groups + + + align:start position:0% +groups +climate Justice is also closely + + align:start position:0% +climate Justice is also closely + + + align:start position:0% +climate Justice is also closely +associated with the idea of + + align:start position:0% +associated with the idea of + + + align:start position:0% +associated with the idea of +transformative Justice these are + + align:start position:0% +transformative Justice these are + + + align:start position:0% +transformative Justice these are +practices and philosophies designed to + + align:start position:0% +practices and philosophies designed to + + + align:start position:0% +practices and philosophies designed to +create change in Social systems I would + + align:start position:0% +create change in Social systems I would + + + align:start position:0% +create change in Social systems I would +encourage you to take note of the idea + + align:start position:0% +encourage you to take note of the idea + + + align:start position:0% +encourage you to take note of the idea +of transformational Justice in shalanda + + align:start position:0% +of transformational Justice in shalanda + + + align:start position:0% +of transformational Justice in shalanda +baker's article that I assigned for this + + align:start position:0% +baker's article that I assigned for this + + + align:start position:0% +baker's article that I assigned for this +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +and also the idea of energy Justice a + + align:start position:0% +and also the idea of energy Justice a + + + align:start position:0% +and also the idea of energy Justice a +number of these different articles + + align:start position:0% +number of these different articles + + + align:start position:0% +number of these different articles +mentioned in the idea of energy Justice + + align:start position:0% +mentioned in the idea of energy Justice + + + align:start position:0% +mentioned in the idea of energy Justice +as a fairly innocent idea in the + + align:start position:0% +as a fairly innocent idea in the + + + align:start position:0% +as a fairly innocent idea in the +literature and the idea of energy + + align:start position:0% +literature and the idea of energy + + + align:start position:0% +literature and the idea of energy +Justice gets at the idea that there are + + align:start position:0% +Justice gets at the idea that there are + + + align:start position:0% +Justice gets at the idea that there are +disproportionate access or + + align:start position:0% +disproportionate access or + + + align:start position:0% +disproportionate access or +disproportionate people who have access + + align:start position:0% +disproportionate people who have access + + + align:start position:0% +disproportionate people who have access +to the Energy System including its + + align:start position:0% +to the Energy System including its + + + align:start position:0% +to the Energy System including its +benefits but also the Energy System we + + align:start position:0% +benefits but also the Energy System we + + + align:start position:0% +benefits but also the Energy System we +know has clear harms and burdens that + + align:start position:0% +know has clear harms and burdens that + + + align:start position:0% +know has clear harms and burdens that +fall disreportationally on certain + + align:start position:0% +fall disreportationally on certain + + + align:start position:0% +fall disreportationally on certain +groups like black Americans and minority + + align:start position:0% +groups like black Americans and minority + + + align:start position:0% +groups like black Americans and minority +groups who live much more closely to the + + align:start position:0% +groups who live much more closely to the + + + align:start position:0% +groups who live much more closely to the +polluting infrastructure that Robert + + align:start position:0% +polluting infrastructure that Robert + + + align:start position:0% +polluting infrastructure that Robert +Bullard Bullard first identified in the + + align:start position:0% +Bullard Bullard first identified in the + + + align:start position:0% +Bullard Bullard first identified in the +70s and 80s + + align:start position:0% +70s and 80s + + + align:start position:0% +70s and 80s +and of course our discussion of kind of + + align:start position:0% +and of course our discussion of kind of + + + align:start position:0% +and of course our discussion of kind of +justice has to get at the idea of + + align:start position:0% +justice has to get at the idea of + + + align:start position:0% +justice has to get at the idea of +disproportionate to who there are plenty + + align:start position:0% +disproportionate to who there are plenty + + + align:start position:0% +disproportionate to who there are plenty +of disappointment harms of the fossil + + align:start position:0% +of disappointment harms of the fossil + + + align:start position:0% +of disappointment harms of the fossil +fuel system to go around but as we start + + align:start position:0% +fuel system to go around but as we start + + + align:start position:0% +fuel system to go around but as we start +to seek an energy transition one group + + align:start position:0% +to seek an energy transition one group + + + align:start position:0% +to seek an energy transition one group +that has been notably skeptical until + + align:start position:0% +that has been notably skeptical until + + + align:start position:0% +that has been notably skeptical until +recently of an energy transition mostly + + align:start position:0% +recently of an energy transition mostly + + + align:start position:0% +recently of an energy transition mostly +pushed by environmentalists unions and + + align:start position:0% +pushed by environmentalists unions and + + + align:start position:0% +pushed by environmentalists unions and +workers have been notably skeptical + + align:start position:0% +workers have been notably skeptical + + + align:start position:0% +workers have been notably skeptical +sometimes of the idea of an energy + + align:start position:0% +sometimes of the idea of an energy + + + align:start position:0% +sometimes of the idea of an energy +transition and the energy transition + + align:start position:0% +transition and the energy transition + + + align:start position:0% +transition and the energy transition +that we are seeking because of probably + + align:start position:0% +that we are seeking because of probably + + + align:start position:0% +that we are seeking because of probably +well-founded skepticism that they will + + align:start position:0% +well-founded skepticism that they will + + + align:start position:0% +well-founded skepticism that they will +may not have the same jobs or standard + + align:start position:0% +may not have the same jobs or standard + + + align:start position:0% +may not have the same jobs or standard +of living in an energy transition and I + + align:start position:0% +of living in an energy transition and I + + + align:start position:0% +of living in an energy transition and I +think for good reason fossil fuel + + align:start position:0% +think for good reason fossil fuel + + + align:start position:0% +think for good reason fossil fuel +dominated communities fossil fuel jobs + + align:start position:0% +dominated communities fossil fuel jobs + + + align:start position:0% +dominated communities fossil fuel jobs +typically are higher paying than average + + align:start position:0% +typically are higher paying than average + + + align:start position:0% +typically are higher paying than average +than other jobs with the same education + + align:start position:0% +than other jobs with the same education + + + align:start position:0% +than other jobs with the same education +level + + align:start position:0% +level + + + align:start position:0% +level +and fossil fuel job in our fossil fuel + + align:start position:0% +and fossil fuel job in our fossil fuel + + + align:start position:0% +and fossil fuel job in our fossil fuel +dominant Community according to this + + align:start position:0% +dominant Community according to this + + + align:start position:0% +dominant Community according to this +marchan Weber study typically creates or + + align:start position:0% +marchan Weber study typically creates or + + + align:start position:0% +marchan Weber study typically creates or +supports two to five other jobs so if we + + align:start position:0% +supports two to five other jobs so if we + + + align:start position:0% +supports two to five other jobs so if we +seek an energy transition how are we + + align:start position:0% +seek an energy transition how are we + + + align:start position:0% +seek an energy transition how are we +going to make sure that workers and + + align:start position:0% +going to make sure that workers and + + + align:start position:0% +going to make sure that workers and +unions and fossil fuel dominated + + align:start position:0% +unions and fossil fuel dominated + + + align:start position:0% +unions and fossil fuel dominated +communities maintain or even improve + + align:start position:0% +communities maintain or even improve + + + align:start position:0% +communities maintain or even improve +their standard of living + + align:start position:0% +their standard of living + + + align:start position:0% +their standard of living +and of course we know that they're just + + align:start position:0% +and of course we know that they're just + + + align:start position:0% +and of course we know that they're just +disproportionate harms on the front line + + align:start position:0% +disproportionate harms on the front line + + + align:start position:0% +disproportionate harms on the front line +our local Justice communities like + + align:start position:0% +our local Justice communities like + + + align:start position:0% +our local Justice communities like +minority groups like African Americans + + align:start position:0% +minority groups like African Americans + + + align:start position:0% +minority groups like African Americans +we know that there are particular places + + align:start position:0% +we know that there are particular places + + + align:start position:0% +we know that there are particular places +that are affected by the harms of fossil + + align:start position:0% +that are affected by the harms of fossil + + + align:start position:0% +that are affected by the harms of fossil +fuels including spills including + + align:start position:0% +fuels including spills including + + + align:start position:0% +fuels including spills including +refining including air pollution and of + + align:start position:0% +refining including air pollution and of + + + align:start position:0% +refining including air pollution and of +course it's also worth noting that these + + align:start position:0% +course it's also worth noting that these + + + align:start position:0% +course it's also worth noting that these +two groups + + align:start position:0% +two groups + + + align:start position:0% +two groups +will have disappointing effects of the + + align:start position:0% +will have disappointing effects of the + + + align:start position:0% +will have disappointing effects of the +energy system are often the same group + + align:start position:0% +energy system are often the same group + + + align:start position:0% +energy system are often the same group +you could be a member of a Frontline + + align:start position:0% +you could be a member of a Frontline + + + align:start position:0% +you could be a member of a Frontline +environmental justice Community whether + + align:start position:0% +environmental justice Community whether + + + align:start position:0% +environmental justice Community whether +you're white or black you may be a + + align:start position:0% +you're white or black you may be a + + + align:start position:0% +you're white or black you may be a +fossil fuel worker also and you may + + align:start position:0% +fossil fuel worker also and you may + + + align:start position:0% +fossil fuel worker also and you may +actually oppose change the fossil fuel + + align:start position:0% +actually oppose change the fossil fuel + + + align:start position:0% +actually oppose change the fossil fuel +system because you're worried about + + align:start position:0% +system because you're worried about + + + align:start position:0% +system because you're worried about +maintaining your standard of living or + + align:start position:0% +maintaining your standard of living or + + + align:start position:0% +maintaining your standard of living or +job + + align:start position:0% +job + + + align:start position:0% +job +and so it's interesting actually if you + + align:start position:0% +and so it's interesting actually if you + + + align:start position:0% +and so it's interesting actually if you +look at the shlanda baker article she + + align:start position:0% +look at the shlanda baker article she + + + align:start position:0% +look at the shlanda baker article she +talks about her black relatives who are + + align:start position:0% +talks about her black relatives who are + + + align:start position:0% +talks about her black relatives who are +fossil fuel workers in Port Arthur and + + align:start position:0% +fossil fuel workers in Port Arthur and + + + align:start position:0% +fossil fuel workers in Port Arthur and +of course this recent headline for the + + align:start position:0% +of course this recent headline for the + + + align:start position:0% +of course this recent headline for the +Washington Post + + align:start position:0% +Washington Post + + + align:start position:0% +Washington Post +a few weeks ago actually kind of + + align:start position:0% +a few weeks ago actually kind of + + + align:start position:0% +a few weeks ago actually kind of +describes now how the conversation has + + align:start position:0% +describes now how the conversation has + + + align:start position:0% +describes now how the conversation has +changed this headline is about people in + + align:start position:0% +changed this headline is about people in + + + align:start position:0% +changed this headline is about people in +Port Arthur Texas who are surrounded by + + align:start position:0% +Port Arthur Texas who are surrounded by + + + align:start position:0% +Port Arthur Texas who are surrounded by +fossil fuels but they fear that the + + align:start position:0% +fossil fuels but they fear that the + + + align:start position:0% +fossil fuels but they fear that the +climate Bill leaves them behind and this + + align:start position:0% +climate Bill leaves them behind and this + + + align:start position:0% +climate Bill leaves them behind and this +includes not only fossil fuel workers + + align:start position:0% +includes not only fossil fuel workers + + + align:start position:0% +includes not only fossil fuel workers +who work in Port Arthur but climate and + + align:start position:0% +who work in Port Arthur but climate and + + + align:start position:0% +who work in Port Arthur but climate and +iranical activists who've been fighting + + align:start position:0% +iranical activists who've been fighting + + + align:start position:0% +iranical activists who've been fighting +this environmental infrastructure for a + + align:start position:0% +this environmental infrastructure for a + + + align:start position:0% +this environmental infrastructure for a +long time the climate bill which I've + + align:start position:0% +long time the climate bill which I've + + + align:start position:0% +long time the climate bill which I've +been celebrating a discussion we know + + align:start position:0% +been celebrating a discussion we know + + + align:start position:0% +been celebrating a discussion we know +has significant gaps and one of the + + align:start position:0% +has significant gaps and one of the + + + align:start position:0% +has significant gaps and one of the +significant gaps of the Barnacle Justice + + align:start position:0% +significant gaps of the Barnacle Justice + + + align:start position:0% +significant gaps of the Barnacle Justice +in fact one of the compromises made in + + align:start position:0% +in fact one of the compromises made in + + + align:start position:0% +in fact one of the compromises made in +the climate legislation was to allow + + align:start position:0% +the climate legislation was to allow + + + align:start position:0% +the climate legislation was to allow +additional oil and gas leasing in the + + align:start position:0% +additional oil and gas leasing in the + + + align:start position:0% +additional oil and gas leasing in the +Gulf of Mexico and additional permitting + + align:start position:0% +Gulf of Mexico and additional permitting + + + align:start position:0% +Gulf of Mexico and additional permitting +of pipelines may be coming this fall but + + align:start position:0% +of pipelines may be coming this fall but + + + align:start position:0% +of pipelines may be coming this fall but +environable Justice activists in places + + align:start position:0% +environable Justice activists in places + + + align:start position:0% +environable Justice activists in places +like Port Arthur are quite disappointed + + align:start position:0% +like Port Arthur are quite disappointed + + + align:start position:0% +like Port Arthur are quite disappointed +by the climate Bill even as much of the + + align:start position:0% +by the climate Bill even as much of the + + + align:start position:0% +by the climate Bill even as much of the +climate movement celebrates this bill + + align:start position:0% +climate movement celebrates this bill + + + align:start position:0% +climate movement celebrates this bill +and so this brings me to kind of the + + align:start position:0% +and so this brings me to kind of the + + + align:start position:0% +and so this brings me to kind of the +basis for our discussion our class + + align:start position:0% +basis for our discussion our class + + + align:start position:0% +basis for our discussion our class +exercise + + align:start position:0% +exercise + + + align:start position:0% +exercise +um that we're going to have this is a + + align:start position:0% +um that we're going to have this is a + + + align:start position:0% +um that we're going to have this is a +geography article by Heffron and + + align:start position:0% +geography article by Heffron and + + + align:start position:0% +geography article by Heffron and +Macaulay asking what is the just + + align:start position:0% +Macaulay asking what is the just + + + align:start position:0% +Macaulay asking what is the just +transition they identify four components + + align:start position:0% +transition they identify four components + + + align:start position:0% +transition they identify four components +of the just transition uh the Justice + + align:start position:0% +of the just transition uh the Justice + + + align:start position:0% +of the just transition uh the Justice +universality it's a geography article + + align:start position:0% +universality it's a geography article + + + align:start position:0% +universality it's a geography article +stay focus on space and also the time I + + align:start position:0% +stay focus on space and also the time I + + + align:start position:0% +stay focus on space and also the time I +want to focus on the different forms of + + align:start position:0% +want to focus on the different forms of + + + align:start position:0% +want to focus on the different forms of +Justice because I would argue that + + align:start position:0% +Justice because I would argue that + + + align:start position:0% +Justice because I would argue that +they're rhetorical forms or rhetorical + + align:start position:0% +they're rhetorical forms or rhetorical + + + align:start position:0% +they're rhetorical forms or rhetorical +framings of the idea of justice and + + align:start position:0% +framings of the idea of justice and + + + align:start position:0% +framings of the idea of justice and +they're all quite different they're the + + align:start position:0% +they're all quite different they're the + + + align:start position:0% +they're all quite different they're the +idea of distributional Justice there's + + align:start position:0% +idea of distributional Justice there's + + + align:start position:0% +idea of distributional Justice there's +procedural Justice there's restorative + + align:start position:0% +procedural Justice there's restorative + + + align:start position:0% +procedural Justice there's restorative +justice they say there's a different + + align:start position:0% +justice they say there's a different + + + align:start position:0% +justice they say there's a different +kind of dimension of universality that + + align:start position:0% +kind of dimension of universality that + + + align:start position:0% +kind of dimension of universality that +Universal forms of Justice may include + + align:start position:0% +Universal forms of Justice may include + + + align:start position:0% +Universal forms of Justice may include +recognition Justice and cosmopolitanism + + align:start position:0% +recognition Justice and cosmopolitanism + + + align:start position:0% +recognition Justice and cosmopolitanism +let's examine that a little more closely + + align:start position:0% +let's examine that a little more closely + + + align:start position:0% +let's examine that a little more closely +how Pi uses it in their article + + align:start position:0% +how Pi uses it in their article + + + align:start position:0% +how Pi uses it in their article +distributional Justice concerns the + + align:start position:0% +distributional Justice concerns the + + + align:start position:0% +distributional Justice concerns the +equitable distribution of burdens and + + align:start position:0% +equitable distribution of burdens and + + + align:start position:0% +equitable distribution of burdens and +benefits of energy and environmental + + align:start position:0% +benefits of energy and environmental + + + align:start position:0% +benefits of energy and environmental +decisions + + align:start position:0% +decisions + + + align:start position:0% +decisions +procedural Justice highlights the right + + align:start position:0% +procedural Justice highlights the right + + + align:start position:0% +procedural Justice highlights the right +to a fair process for different + + align:start position:0% +to a fair process for different + + + align:start position:0% +to a fair process for different +stakeholders to take part equitably in + + align:start position:0% +stakeholders to take part equitably in + + + align:start position:0% +stakeholders to take part equitably in +the decision-making process + + align:start position:0% +the decision-making process + + + align:start position:0% +the decision-making process +restorative justice primarily aims to + + align:start position:0% +restorative justice primarily aims to + + + align:start position:0% +restorative justice primarily aims to +repair the harm done to individuals + + align:start position:0% +repair the harm done to individuals + + + align:start position:0% +repair the harm done to individuals +instead of focusing upon punishing the + + align:start position:0% +instead of focusing upon punishing the + + + align:start position:0% +instead of focusing upon punishing the +offender + + align:start position:0% +offender + + + align:start position:0% +offender +whereas Universal conceptions of Justice + + align:start position:0% +whereas Universal conceptions of Justice + + + align:start position:0% +whereas Universal conceptions of Justice +do draw on these other forms of justice + + align:start position:0% +do draw on these other forms of justice + + + align:start position:0% +do draw on these other forms of justice +but high at all distinguished + + align:start position:0% +but high at all distinguished + + + align:start position:0% +but high at all distinguished +recognition justice has entailing + + align:start position:0% +recognition justice has entailing + + + align:start position:0% +recognition justice has entailing +recognition of parts of society that + + align:start position:0% +recognition of parts of society that + + + align:start position:0% +recognition of parts of society that +might suffer as the result of energy in + + align:start position:0% +might suffer as the result of energy in + + + align:start position:0% +might suffer as the result of energy in +our decisions and identify individuals + + align:start position:0% +our decisions and identify individuals + + + align:start position:0% +our decisions and identify individuals +and groups who might be impacted by such + + align:start position:0% +and groups who might be impacted by such + + + align:start position:0% +and groups who might be impacted by such +decisions the jump to kind of + + align:start position:0% +decisions the jump to kind of + + + align:start position:0% +decisions the jump to kind of +universality is to start to think about + + align:start position:0% +universality is to start to think about + + + align:start position:0% +universality is to start to think about +groups of individuals rather than + + align:start position:0% +groups of individuals rather than + + + align:start position:0% +groups of individuals rather than +specific harm or specific individuals + + align:start position:0% +specific harm or specific individuals + + + align:start position:0% +specific harm or specific individuals +and of course how can Paul Injustice is + + align:start position:0% +and of course how can Paul Injustice is + + + align:start position:0% +and of course how can Paul Injustice is +an idea that reinforces all of the above + + align:start position:0% +an idea that reinforces all of the above + + + align:start position:0% +an idea that reinforces all of the above +Justice forms but states that the above + + align:start position:0% +Justice forms but states that the above + + + align:start position:0% +Justice forms but states that the above +forms of Justice must apply universally + + align:start position:0% +forms of Justice must apply universally + + + align:start position:0% +forms of Justice must apply universally +to all human beings I think it's + + align:start position:0% +to all human beings I think it's + + + align:start position:0% +to all human beings I think it's +important for us to think about how our + + align:start position:0% +important for us to think about how our + + + align:start position:0% +important for us to think about how our +conceptions of justice and how our + + align:start position:0% +conceptions of justice and how our + + + align:start position:0% +conceptions of justice and how our +rhetorical framing of Justice May apply + + align:start position:0% +rhetorical framing of Justice May apply + + + align:start position:0% +rhetorical framing of Justice May apply +to different groups does it apply + + align:start position:0% +to different groups does it apply + + + align:start position:0% +to different groups does it apply +differently to people in cities or rural + + align:start position:0% +differently to people in cities or rural + + + align:start position:0% +differently to people in cities or rural +areas does it apply differently to + + align:start position:0% +areas does it apply differently to + + + align:start position:0% +areas does it apply differently to +people involved in the fossil fuel + + align:start position:0% +people involved in the fossil fuel + + + align:start position:0% +people involved in the fossil fuel +industry but they're not their white or + + align:start position:0% +industry but they're not their white or + + + align:start position:0% +industry but they're not their white or +they're black in the United States do we + + align:start position:0% +they're black in the United States do we + + + align:start position:0% +they're black in the United States do we +expect that energy work workers the + + align:start position:0% +expect that energy work workers the + + + align:start position:0% +expect that energy work workers the +United States should have the same + + align:start position:0% +United States should have the same + + + align:start position:0% +United States should have the same +standard living as energy workers in + + align:start position:0% +standard living as energy workers in + + + align:start position:0% +standard living as energy workers in +other countries say India say in + + align:start position:0% +other countries say India say in + + + align:start position:0% +other countries say India say in +Pakistan what does this mean for us for + + align:start position:0% +Pakistan what does this mean for us for + + + align:start position:0% +Pakistan what does this mean for us for +our conception of climate Justice + + align:start position:0% +our conception of climate Justice + + + align:start position:0% +our conception of climate Justice +depending on the scale that we apply it + + align:start position:0% +depending on the scale that we apply it + + + align:start position:0% +depending on the scale that we apply it +to + + align:start position:0% +to + + + align:start position:0% +to +and of course I would argue that our + + align:start position:0% +and of course I would argue that our + + + align:start position:0% +and of course I would argue that our +idea of climate Justice is fairly + + align:start position:0% +idea of climate Justice is fairly + + + align:start position:0% +idea of climate Justice is fairly +Inseparable from our idea of politics + + align:start position:0% +Inseparable from our idea of politics + + + align:start position:0% +Inseparable from our idea of politics +just to take the climate part this is a + + align:start position:0% +just to take the climate part this is a + + + align:start position:0% +just to take the climate part this is a +figure from the Yale project on climate + + align:start position:0% +figure from the Yale project on climate + + + align:start position:0% +figure from the Yale project on climate +Communication in 2018 they look at + + align:start position:0% +Communication in 2018 they look at + + + align:start position:0% +Communication in 2018 they look at +Democratic and Republican views of + + align:start position:0% +Democratic and Republican views of + + + align:start position:0% +Democratic and Republican views of +global warming and when they asked + + align:start position:0% +global warming and when they asked + + + align:start position:0% +global warming and when they asked +estimated registered voters what percent + + align:start position:0% +estimated registered voters what percent + + + align:start position:0% +estimated registered voters what percent +if they're worried about global warming + + align:start position:0% +if they're worried about global warming + + + align:start position:0% +if they're worried about global warming +the percentages are quite striking you + + align:start position:0% +the percentages are quite striking you + + + align:start position:0% +the percentages are quite striking you +look here in the left-hand side + + align:start position:0% +look here in the left-hand side + + + align:start position:0% +look here in the left-hand side +regardless of Geography about 80 to 90 + + align:start position:0% +regardless of Geography about 80 to 90 + + + align:start position:0% +regardless of Geography about 80 to 90 +percent of Democrats are fairly + + align:start position:0% +percent of Democrats are fairly + + + align:start position:0% +percent of Democrats are fairly +concerned about global warming if you + + align:start position:0% +concerned about global warming if you + + + align:start position:0% +concerned about global warming if you +look on the right hand side about maybe + + align:start position:0% +look on the right hand side about maybe + + + align:start position:0% +look on the right hand side about maybe +30 to 40 percent of Republicans are + + align:start position:0% +30 to 40 percent of Republicans are + + + align:start position:0% +30 to 40 percent of Republicans are +quite concerned about global warming + + align:start position:0% +quite concerned about global warming + + + align:start position:0% +quite concerned about global warming +this is not to say that there are equal + + align:start position:0% +this is not to say that there are equal + + + align:start position:0% +this is not to say that there are equal +distributions of Democrats and + + align:start position:0% +distributions of Democrats and + + + align:start position:0% +distributions of Democrats and +Republicans across the United States but + + align:start position:0% +Republicans across the United States but + + + align:start position:0% +Republicans across the United States but +I would argue for the purposes of our + + align:start position:0% +I would argue for the purposes of our + + + align:start position:0% +I would argue for the purposes of our +class talking about cities and what + + align:start position:0% +class talking about cities and what + + + align:start position:0% +class talking about cities and what +cities can do there may not be similar + + align:start position:0% +cities can do there may not be similar + + + align:start position:0% +cities can do there may not be similar +numbers of Democrats Republicans and + + align:start position:0% +numbers of Democrats Republicans and + + + align:start position:0% +numbers of Democrats Republicans and +City and rural areas that's for sure but + + align:start position:0% +City and rural areas that's for sure but + + + align:start position:0% +City and rural areas that's for sure but +at the same time it's also quite + + align:start position:0% +at the same time it's also quite + + + align:start position:0% +at the same time it's also quite +possible that our partisanship or our + + align:start position:0% +possible that our partisanship or our + + + align:start position:0% +possible that our partisanship or our +political beliefs made Trump necessarily + + align:start position:0% +political beliefs made Trump necessarily + + + align:start position:0% +political beliefs made Trump necessarily +where we live + + align:start position:0% +where we live + + + align:start position:0% +where we live +I guess unintended and this may affect + + align:start position:0% +I guess unintended and this may affect + + + align:start position:0% +I guess unintended and this may affect +how we talk about climate not only + + align:start position:0% +how we talk about climate not only + + + align:start position:0% +how we talk about climate not only +climate but even the word justice May + + align:start position:0% +climate but even the word justice May + + + align:start position:0% +climate but even the word justice May +resonate quite differently we talk about + + align:start position:0% +resonate quite differently we talk about + + + align:start position:0% +resonate quite differently we talk about +racial and social justice quite often in + + align:start position:0% +racial and social justice quite often in + + + align:start position:0% +racial and social justice quite often in +universities I would argue that Justice + + align:start position:0% +universities I would argue that Justice + + + align:start position:0% +universities I would argue that Justice +may not be a frame or a phrase that even + + align:start position:0% +may not be a frame or a phrase that even + + + align:start position:0% +may not be a frame or a phrase that even +carries very far outside of universities + + align:start position:0% +carries very far outside of universities + + + align:start position:0% +carries very far outside of universities +for example ideas about fairness May + + align:start position:0% +for example ideas about fairness May + + + align:start position:0% +for example ideas about fairness May +resonate more deeply with different + + align:start position:0% +resonate more deeply with different + + + align:start position:0% +resonate more deeply with different +audiences + + align:start position:0% +audiences + + + align:start position:0% +audiences +just to kind of reinforce this point + + align:start position:0% +just to kind of reinforce this point + + + align:start position:0% +just to kind of reinforce this point +again another figure from the Yale + + align:start position:0% +again another figure from the Yale + + + align:start position:0% +again another figure from the Yale +project in climate communication this is + + align:start position:0% +project in climate communication this is + + + align:start position:0% +project in climate communication this is +from their sixth American study they + + align:start position:0% +from their sixth American study they + + + align:start position:0% +from their sixth American study they +have run I think 20 or so surveys since + + align:start position:0% +have run I think 20 or so surveys since + + + align:start position:0% +have run I think 20 or so surveys since +2008 looking at the U.S adults + + align:start position:0% +2008 looking at the U.S adults + + + align:start position:0% +2008 looking at the U.S adults +populations attitudes about climate + + align:start position:0% +populations attitudes about climate + + + align:start position:0% +populations attitudes about climate +change they ask questions about race + + align:start position:0% +change they ask questions about race + + + align:start position:0% +change they ask questions about race +ethnicity harder than affiliation or + + align:start position:0% +ethnicity harder than affiliation or + + + align:start position:0% +ethnicity harder than affiliation or +political affiliation and they find that + + align:start position:0% +political affiliation and they find that + + + align:start position:0% +political affiliation and they find that +they can segment the US population + + align:start position:0% +they can segment the US population + + + align:start position:0% +they can segment the US population +overwhelmingly into six groups on the + + align:start position:0% +overwhelmingly into six groups on the + + + align:start position:0% +overwhelmingly into six groups on the +left hand side there's the alarmed and + + align:start position:0% +left hand side there's the alarmed and + + + align:start position:0% +left hand side there's the alarmed and +concert concerned groups these are the + + align:start position:0% +concert concerned groups these are the + + + align:start position:0% +concert concerned groups these are the +groups that had the highest belief in + + align:start position:0% +groups that had the highest belief in + + + align:start position:0% +groups that had the highest belief in +global warming they're most concerned + + align:start position:0% +global warming they're most concerned + + + align:start position:0% +global warming they're most concerned +about climate change they're most + + align:start position:0% +about climate change they're most + + + align:start position:0% +about climate change they're most +motivated to do something about it and + + align:start position:0% +motivated to do something about it and + + + align:start position:0% +motivated to do something about it and +on the right hand side these four groups + + align:start position:0% +on the right hand side these four groups + + + align:start position:0% +on the right hand side these four groups +the cautious the disengaged the doubtful + + align:start position:0% +the cautious the disengaged the doubtful + + + align:start position:0% +the cautious the disengaged the doubtful +and the dismissive happy lowest belief + + align:start position:0% +and the dismissive happy lowest belief + + + align:start position:0% +and the dismissive happy lowest belief +in global warming they're at least + + align:start position:0% +in global warming they're at least + + + align:start position:0% +in global warming they're at least +concerned they're least motivated of + + align:start position:0% +concerned they're least motivated of + + + align:start position:0% +concerned they're least motivated of +course + + align:start position:0% +course + + + align:start position:0% +course +on the left hand side of these two + + align:start position:0% +on the left hand side of these two + + + align:start position:0% +on the left hand side of these two +groups alarm to concern are dominated by + + align:start position:0% +groups alarm to concern are dominated by + + + align:start position:0% +groups alarm to concern are dominated by +democrats the other four groups are + + align:start position:0% +democrats the other four groups are + + + align:start position:0% +democrats the other four groups are +dominated by Republicans the groups on + + align:start position:0% +dominated by Republicans the groups on + + + align:start position:0% +dominated by Republicans the groups on +the left tend to skew younger and more + + align:start position:0% +the left tend to skew younger and more + + + align:start position:0% +the left tend to skew younger and more +female big groups on the right tend to + + align:start position:0% +female big groups on the right tend to + + + align:start position:0% +female big groups on the right tend to +skew older and more male and so this is + + align:start position:0% +skew older and more male and so this is + + + align:start position:0% +skew older and more male and so this is +just a question about how are we going + + align:start position:0% +just a question about how are we going + + + align:start position:0% +just a question about how are we going +to present the idea of climate Justice + + align:start position:0% +to present the idea of climate Justice + + + align:start position:0% +to present the idea of climate Justice +is this an idea that is going to have + + align:start position:0% +is this an idea that is going to have + + + align:start position:0% +is this an idea that is going to have +attraction with all six of Youth groups + + align:start position:0% +attraction with all six of Youth groups + + + align:start position:0% +attraction with all six of Youth groups +we're going to discuss this in class + + align:start position:0% +we're going to discuss this in class + + + align:start position:0% +we're going to discuss this in class +finally there's this interesting quiz I + + align:start position:0% +finally there's this interesting quiz I + + + align:start position:0% +finally there's this interesting quiz I +kind of enjoy taking at the New York + + align:start position:0% +kind of enjoy taking at the New York + + + align:start position:0% +kind of enjoy taking at the New York +Times quiz if America had six parties + + align:start position:0% +Times quiz if America had six parties + + + align:start position:0% +Times quiz if America had six parties +rather than two which would you belong + + align:start position:0% +rather than two which would you belong + + + align:start position:0% +rather than two which would you belong +to this is a political scientist simply + + align:start position:0% +to this is a political scientist simply + + + align:start position:0% +to this is a political scientist simply +commenting on how our major political + + align:start position:0% +commenting on how our major political + + + align:start position:0% +commenting on how our major political +parties are distributed or comprised of + + align:start position:0% +parties are distributed or comprised of + + + align:start position:0% +parties are distributed or comprised of +different coalitions and different + + align:start position:0% +different coalitions and different + + + align:start position:0% +different coalitions and different +groups those groups have different + + align:start position:0% +groups those groups have different + + + align:start position:0% +groups those groups have different +social certain levels of social + + align:start position:0% +social certain levels of social + + + align:start position:0% +social certain levels of social +conservatism and economic conservatism + + align:start position:0% +conservatism and economic conservatism + + + align:start position:0% +conservatism and economic conservatism +for example you could take the American + + align:start position:0% +for example you could take the American + + + align:start position:0% +for example you could take the American +labor party Progressive Party a new + + align:start position:0% +labor party Progressive Party a new + + + align:start position:0% +labor party Progressive Party a new +Liberal Party as relatively Democratic + + align:start position:0% +Liberal Party as relatively Democratic + + + align:start position:0% +Liberal Party as relatively Democratic +groups but it turns out that the + + align:start position:0% +groups but it turns out that the + + + align:start position:0% +groups but it turns out that the +American labor party and the growth and + + align:start position:0% +American labor party and the growth and + + + align:start position:0% +American labor party and the growth and +opportunity party uh probably more + + align:start position:0% +opportunity party uh probably more + + + align:start position:0% +opportunity party uh probably more +Associated Republicans have similar + + align:start position:0% +Associated Republicans have similar + + + align:start position:0% +Associated Republicans have similar +attitudes about social conservatism + + align:start position:0% +attitudes about social conservatism + + + align:start position:0% +attitudes about social conservatism +at the same time if you look at the + + align:start position:0% +at the same time if you look at the + + + align:start position:0% +at the same time if you look at the +Patriot party the Christian conservative + + align:start position:0% +Patriot party the Christian conservative + + + align:start position:0% +Patriot party the Christian conservative +party and the growth opportunity party + + align:start position:0% +party and the growth opportunity party + + + align:start position:0% +party and the growth opportunity party +it turns out that part of the royal + + align:start position:0% +it turns out that part of the royal + + + align:start position:0% +it turns out that part of the royal +Republican Coalition or Republican party + + align:start position:0% +Republican Coalition or Republican party + + + align:start position:0% +Republican Coalition or Republican party +is relatively close to the economically + + align:start position:0% +is relatively close to the economically + + + align:start position:0% +is relatively close to the economically +conservative group in the Democratic + + align:start position:0% +conservative group in the Democratic + + + align:start position:0% +conservative group in the Democratic +Coalition all the new Liberal Party and + + align:start position:0% +Coalition all the new Liberal Party and + + + align:start position:0% +Coalition all the new Liberal Party and +so this is to say that all of our + + align:start position:0% +so this is to say that all of our + + + align:start position:0% +so this is to say that all of our +different rhetorical framings of Justice + + align:start position:0% +different rhetorical framings of Justice + + + align:start position:0% +different rhetorical framings of Justice +how we talk about history some of these + + align:start position:0% +how we talk about history some of these + + + align:start position:0% +how we talk about history some of these +ideas how we talk about the imperative + + align:start position:0% +ideas how we talk about the imperative + + + align:start position:0% +ideas how we talk about the imperative +to achieve climate Justice May resonate + + align:start position:0% +to achieve climate Justice May resonate + + + align:start position:0% +to achieve climate Justice May resonate +differently with all six of these groups + + align:start position:0% +differently with all six of these groups + + + align:start position:0% +differently with all six of these groups +so what we're going to do in our class + + align:start position:0% +so what we're going to do in our class + + + align:start position:0% +so what we're going to do in our class +discussion is we're going to do a + + align:start position:0% +discussion is we're going to do a + + + align:start position:0% +discussion is we're going to do a +discussion exercise that requires you to + + align:start position:0% +discussion exercise that requires you to + + + align:start position:0% +discussion exercise that requires you to +argue for a different energy policy + + align:start position:0% +argue for a different energy policy + + + align:start position:0% +argue for a different energy policy +based on different conceptions of + + align:start position:0% +based on different conceptions of + + + align:start position:0% +based on different conceptions of +Justice + + align:start position:0% +Justice + + + align:start position:0% +Justice +and we're going to do this as discussion + + align:start position:0% +and we're going to do this as discussion + + + align:start position:0% +and we're going to do this as discussion +together and it's good for you to + + align:start position:0% +together and it's good for you to + + + align:start position:0% +together and it's good for you to +prepare by looking at the Remy edel + + align:start position:0% +prepare by looking at the Remy edel + + + align:start position:0% +prepare by looking at the Remy edel +article looking at a specific energy + + align:start position:0% +article looking at a specific energy + + + align:start position:0% +article looking at a specific energy +policy and thinking about how different + + align:start position:0% +policy and thinking about how different + + + align:start position:0% +policy and thinking about how different +groups might talk about this energy + + align:start position:0% +groups might talk about this energy + + + align:start position:0% +groups might talk about this energy +policy \ No newline at end of file diff --git a/QC8q4oYKwBI.txt b/QC8q4oYKwBI.txt new file mode 100644 index 0000000000000000000000000000000000000000..a547479bd9aff79660e06054611c18b096010dae --- /dev/null +++ b/QC8q4oYKwBI.txt @@ -0,0 +1,16659 @@ +align:start position:0% + +Today we're going to talk about + + align:start position:0% +Today we're going to talk about + + + align:start position:0% +Today we're going to talk about +peerguided learning at scale. Um the + + align:start position:0% +peerguided learning at scale. Um the + + + align:start position:0% +peerguided learning at scale. Um the +thing I asked you to do for today was to + + align:start position:0% +thing I asked you to do for today was to + + + align:start position:0% +thing I asked you to do for today was to +write a little bit in your learning + + align:start position:0% +write a little bit in your learning + + + align:start position:0% +write a little bit in your learning +journal about um one of your hobbies + + align:start position:0% +journal about um one of your hobbies + + + align:start position:0% +journal about um one of your hobbies +that you use online resources to learn + + align:start position:0% +that you use online resources to learn + + + align:start position:0% +that you use online resources to learn +from. Um, so just get in groups of + + align:start position:0% +from. Um, so just get in groups of + + + align:start position:0% +from. Um, so just get in groups of +three, um, and spend the first few + + align:start position:0% +three, um, and spend the first few + + + align:start position:0% +three, um, and spend the first few +minutes talking to each other about what + + align:start position:0% +minutes talking to each other about what + + + align:start position:0% +minutes talking to each other about what +kinds of, uh, hobbies you have and what + + align:start position:0% +kinds of, uh, hobbies you have and what + + + align:start position:0% +kinds of, uh, hobbies you have and what +kind of online learning you do in those + + align:start position:0% +kind of online learning you do in those + + + align:start position:0% +kind of online learning you do in those +hobbies. Does that make sense? Ready? + + align:start position:0% +hobbies. Does that make sense? Ready? + + + align:start position:0% +hobbies. Does that make sense? Ready? +Go. + + align:start position:0% + + + + align:start position:0% + +All right, come on back. Great + + align:start position:0% +All right, come on back. Great + + + align:start position:0% +All right, come on back. Great +condition. So, first of all, Omar should + + align:start position:0% +condition. So, first of all, Omar should + + + align:start position:0% +condition. So, first of all, Omar should +show us his camera. Do you want to talk + + align:start position:0% +show us his camera. Do you want to talk + + + align:start position:0% +show us his camera. Do you want to talk +about um, so I I I talked about + + align:start position:0% +about um, so I I I talked about + + + align:start position:0% +about um, so I I I talked about +photography? Like I spend an unhealthy + + align:start position:0% +photography? Like I spend an unhealthy + + + align:start position:0% +photography? Like I spend an unhealthy +amount of time on YouTube like with + + align:start position:0% +amount of time on YouTube like with + + + align:start position:0% +amount of time on YouTube like with +photography tutorials. And so this + + align:start position:0% +photography tutorials. And so this + + + align:start position:0% +photography tutorials. And so this +camera is a 50-y old camera and I had no + + align:start position:0% +camera is a 50-y old camera and I had no + + + align:start position:0% +camera is a 50-y old camera and I had no +idea um how to even begin looking for + + align:start position:0% +idea um how to even begin looking for + + + align:start position:0% +idea um how to even begin looking for +one. And like these last three weeks + + align:start position:0% +one. And like these last three weeks + + + align:start position:0% +one. And like these last three weeks +I've been looking because I want to run + + align:start position:0% +I've been looking because I want to run + + + align:start position:0% +I've been looking because I want to run +a CPW event um for uh admits on how to + + align:start position:0% +a CPW event um for uh admits on how to + + + align:start position:0% +a CPW event um for uh admits on how to +use an SLR camera. Isn't that cool? So I + + align:start position:0% +use an SLR camera. Isn't that cool? So I + + + align:start position:0% +use an SLR camera. Isn't that cool? So I +don't know like this is in really great + + align:start position:0% +don't know like this is in really great + + + align:start position:0% +don't know like this is in really great +condition and I was like on eBay for + + align:start position:0% +condition and I was like on eBay for + + + align:start position:0% +condition and I was like on eBay for +hours but I you know watched YouTube + + align:start position:0% +hours but I you know watched YouTube + + + align:start position:0% +hours but I you know watched YouTube +tutorials was reading on like Reddit + + align:start position:0% +tutorials was reading on like Reddit + + + align:start position:0% +tutorials was reading on like Reddit +forums, photography forums, DP review, + + align:start position:0% +forums, photography forums, DP review, + + + align:start position:0% +forums, photography forums, DP review, +pedopixel like on what to look out for + + align:start position:0% +pedopixel like on what to look out for + + + align:start position:0% +pedopixel like on what to look out for +and before that like learning how to + + align:start position:0% +and before that like learning how to + + + align:start position:0% +and before that like learning how to +actually take photos. Um was all done + + align:start position:0% +actually take photos. Um was all done + + + align:start position:0% +actually take photos. Um was all done +through YouTube. It was selftaught. I + + align:start position:0% +through YouTube. It was selftaught. I + + + align:start position:0% +through YouTube. It was selftaught. I +started off with a phone and then I + + align:start position:0% +started off with a phone and then I + + + align:start position:0% +started off with a phone and then I +slowly built up um my toolbox once I had + + align:start position:0% +slowly built up um my toolbox once I had + + + align:start position:0% +slowly built up um my toolbox once I had +the knowledge and yeah now I'm like the + + align:start position:0% +the knowledge and yeah now I'm like the + + + align:start position:0% +the knowledge and yeah now I'm like the +photo editor for the tech. I stuff for + + align:start position:0% +photo editor for the tech. I stuff for + + + align:start position:0% +photo editor for the tech. I stuff for +yearbook and now I do a lot of stuff for + + align:start position:0% +yearbook and now I do a lot of stuff for + + + align:start position:0% +yearbook and now I do a lot of stuff for +photography and now I'm actually + + align:start position:0% +photography and now I'm actually + + + align:start position:0% +photography and now I'm actually +teaching others. Um I recently actually + + align:start position:0% +teaching others. Um I recently actually + + + align:start position:0% +teaching others. Um I recently actually +just interviewed up here this I + + align:start position:0% +just interviewed up here this I + + + align:start position:0% +just interviewed up here this I +interviewed for to teach a digital + + align:start position:0% +interviewed for to teach a digital + + + align:start position:0% +interviewed for to teach a digital +photography course although due to time + + align:start position:0% +photography course although due to time + + + align:start position:0% +photography course although due to time +conflicts I won't be able to do that. Um + + align:start position:0% +conflicts I won't be able to do that. Um + + + align:start position:0% +conflicts I won't be able to do that. Um +but I did interview and I um was about + + align:start position:0% +but I did interview and I um was about + + + align:start position:0% +but I did interview and I um was about +to go on the other side of that um + + align:start position:0% +to go on the other side of that um + + + align:start position:0% +to go on the other side of that um +learning experience. + + align:start position:0% +learning experience. + + + align:start position:0% +learning experience. +Camera's rad. I just got it um before my + + align:start position:0% +Camera's rad. I just got it um before my + + + align:start position:0% +Camera's rad. I just got it um before my +last class. So like I need to go to a + + align:start position:0% +last class. So like I need to go to a + + + align:start position:0% +last class. So like I need to go to a +camera shop just to make sure it works. + + align:start position:0% +camera shop just to make sure it works. + + + align:start position:0% +camera shop just to make sure it works. +um which I'll be doing after this class. + + align:start position:0% +um which I'll be doing after this class. + + + align:start position:0% +um which I'll be doing after this class. +A photo of that. I want a photo a photo + + align:start position:0% +A photo of that. I want a photo a photo + + + align:start position:0% +A photo of that. I want a photo a photo +of Omar with his new camera taken with a + + align:start position:0% +of Omar with his new camera taken with a + + + align:start position:0% +of Omar with his new camera taken with a +contemporary. + + align:start position:0% + + + + align:start position:0% + +Yeah. I I I mean those Polaroid cameras + + align:start position:0% +Yeah. I I I mean those Polaroid cameras + + + align:start position:0% +Yeah. I I I mean those Polaroid cameras +became much more widely accessible + + align:start position:0% +became much more widely accessible + + + align:start position:0% +became much more widely accessible +probably when I was in grade school. + + align:start position:0% +probably when I was in grade school. + + + align:start position:0% +probably when I was in grade school. +Like they were pretty common and then + + align:start position:0% +Like they were pretty common and then + + + align:start position:0% +Like they were pretty common and then +and then there was sort of a revival in + + align:start position:0% +and then there was sort of a revival in + + + align:start position:0% +and then there was sort of a revival in +the last few years. So like my daughter + + align:start position:0% +the last few years. So like my daughter + + + align:start position:0% +the last few years. So like my daughter +has a Polaroid camera. I don't think + + align:start position:0% +has a Polaroid camera. I don't think + + + align:start position:0% +has a Polaroid camera. I don't think +it's called. We call them Polaroid + + align:start position:0% +it's called. We call them Polaroid + + + align:start position:0% +it's called. We call them Polaroid +cameras because they probably have some + + align:start position:0% +cameras because they probably have some + + + align:start position:0% +cameras because they probably have some +different term now of instant camera or + + align:start position:0% +different term now of instant camera or + + + align:start position:0% +different term now of instant camera or +something like that. Um, anybody have a + + align:start position:0% +something like that. Um, anybody have a + + + align:start position:0% +something like that. Um, anybody have a +completely different hobby from Omar + + align:start position:0% +completely different hobby from Omar + + + align:start position:0% +completely different hobby from Omar +where you could tell a very similar kind + + align:start position:0% +where you could tell a very similar kind + + + align:start position:0% +where you could tell a very similar kind +of story about learning + + align:start position:0% + + + + align:start position:0% + +or I guess like you know similar sort of + + align:start position:0% +or I guess like you know similar sort of + + + align:start position:0% +or I guess like you know similar sort of +story of learning is like you know + + align:start position:0% +story of learning is like you know + + + align:start position:0% +story of learning is like you know +through YouTube right like I want to or + + align:start position:0% +through YouTube right like I want to or + + + align:start position:0% +through YouTube right like I want to or +I'm like starting to learn how to like + + align:start position:0% +I'm like starting to learn how to like + + + align:start position:0% +I'm like starting to learn how to like +play guitar and bass and stuff. Um, but + + align:start position:0% +play guitar and bass and stuff. Um, but + + + align:start position:0% +play guitar and bass and stuff. Um, but +the thing with YouTube is it's like we + + align:start position:0% +the thing with YouTube is it's like we + + + align:start position:0% +the thing with YouTube is it's like we +talk about like algorithm guided + + align:start position:0% +talk about like algorithm guided + + + align:start position:0% +talk about like algorithm guided +learning or whatever, but like it kind + + align:start position:0% +learning or whatever, but like it kind + + + align:start position:0% +learning or whatever, but like it kind +of almost feels like YouTube's sort of + + align:start position:0% +of almost feels like YouTube's sort of + + + align:start position:0% +of almost feels like YouTube's sort of +an algorithm kind of guided learning in + + align:start position:0% +an algorithm kind of guided learning in + + + align:start position:0% +an algorithm kind of guided learning in +a way or like I feel like the YouTube + + align:start position:0% +a way or like I feel like the YouTube + + + align:start position:0% +a way or like I feel like the YouTube +algorithm really sort of drives my + + align:start position:0% +algorithm really sort of drives my + + + align:start position:0% +algorithm really sort of drives my +interests or like diverts my interests + + align:start position:0% +interests or like diverts my interests + + + align:start position:0% +interests or like diverts my interests +into different things at different + + align:start position:0% +into different things at different + + + align:start position:0% +into different things at different +periods of time. Like on a weekby- week + + align:start position:0% +periods of time. Like on a weekby- week + + + align:start position:0% +periods of time. Like on a weekby- week +beek basis, I can be interested in + + align:start position:0% +beek basis, I can be interested in + + + align:start position:0% +beek basis, I can be interested in +something completely different than what + + align:start position:0% +something completely different than what + + + align:start position:0% +something completely different than what +I was interested in last week. So, it + + align:start position:0% +I was interested in last week. So, it + + + align:start position:0% +I was interested in last week. So, it +feels like I like I'm just sort of + + align:start position:0% +feels like I like I'm just sort of + + + align:start position:0% +feels like I like I'm just sort of +moving through a bunch of like different + + align:start position:0% +moving through a bunch of like different + + + align:start position:0% +moving through a bunch of like different +hobbies and because I feel like I'm at + + align:start position:0% +hobbies and because I feel like I'm at + + + align:start position:0% +hobbies and because I feel like I'm at +the whim of the YouTube algorithm + + align:start position:0% +the whim of the YouTube algorithm + + + align:start position:0% +the whim of the YouTube algorithm +sometimes. Oh, yeah. Yeah. Yeah. Yeah. + + align:start position:0% +sometimes. Oh, yeah. Yeah. Yeah. Yeah. + + + align:start position:0% +sometimes. Oh, yeah. Yeah. Yeah. Yeah. +People Yeah. Yeah. No, I think people + + align:start position:0% +People Yeah. Yeah. No, I think people + + + align:start position:0% +People Yeah. Yeah. No, I think people +feel that way with lots of uh kind of + + align:start position:0% +feel that way with lots of uh kind of + + + align:start position:0% +feel that way with lots of uh kind of +technologies that do some kind of + + align:start position:0% +technologies that do some kind of + + + align:start position:0% +technologies that do some kind of +aggregation. Pinterest for people who do + + align:start position:0% +aggregation. Pinterest for people who do + + + align:start position:0% +aggregation. Pinterest for people who do +crafty kinds of things. Tik Tok for + + align:start position:0% +crafty kinds of things. Tik Tok for + + + align:start position:0% +crafty kinds of things. Tik Tok for +people who follow media and stuff like + + align:start position:0% +people who follow media and stuff like + + + align:start position:0% +people who follow media and stuff like +that. Yeah. Good. What other what other + + align:start position:0% +that. Yeah. Good. What other what other + + + align:start position:0% +that. Yeah. Good. What other what other +hobbies do you talk about or what other + + align:start position:0% +hobbies do you talk about or what other + + + align:start position:0% +hobbies do you talk about or what other +sort of learn like informal learning + + align:start position:0% +sort of learn like informal learning + + + align:start position:0% +sort of learn like informal learning +strategies seem important and + + align:start position:0% +strategies seem important and + + + align:start position:0% +strategies seem important and +interesting or things that you were + + align:start position:0% +interesting or things that you were + + + align:start position:0% +interesting or things that you were +talking about in your groups? + + align:start position:0% +talking about in your groups? + + + align:start position:0% +talking about in your groups? +Yeah. Awesome. I'll say like on a less I + + align:start position:0% +Yeah. Awesome. I'll say like on a less I + + + align:start position:0% +Yeah. Awesome. I'll say like on a less I +guess handson like level. Um, I like use + + align:start position:0% +guess handson like level. Um, I like use + + + align:start position:0% +guess handson like level. Um, I like use +like similar resources like YouTube and + + align:start position:0% +like similar resources like YouTube and + + + align:start position:0% +like similar resources like YouTube and +stuff like that for like a lot of like + + align:start position:0% +stuff like that for like a lot of like + + + align:start position:0% +stuff like that for like a lot of like +collecting knowledge for like things + + align:start position:0% +collecting knowledge for like things + + + align:start position:0% +collecting knowledge for like things +that I'm interested in like fashion for + + align:start position:0% +that I'm interested in like fashion for + + + align:start position:0% +that I'm interested in like fashion for +example because a lot of a lot of it is + + align:start position:0% +example because a lot of a lot of it is + + + align:start position:0% +example because a lot of a lot of it is +like you know like like in New York + + align:start position:0% +like you know like like in New York + + + align:start position:0% +like you know like like in New York +fashion week for example it's like these + + align:start position:0% +fashion week for example it's like these + + + align:start position:0% +fashion week for example it's like these +very condensed times right where like + + align:start position:0% +very condensed times right where like + + + align:start position:0% +very condensed times right where like +it's all happening and a lot of people + + align:start position:0% +it's all happening and a lot of people + + + align:start position:0% +it's all happening and a lot of people +follow very closely but if you're an MIT + + align:start position:0% +follow very closely but if you're an MIT + + + align:start position:0% +follow very closely but if you're an MIT +student you're probably like I can't + + align:start position:0% +student you're probably like I can't + + + align:start position:0% +student you're probably like I can't +feeling + + align:start position:0% +feeling + + + align:start position:0% +feeling +But like then you can like watch + + align:start position:0% +But like then you can like watch + + + align:start position:0% +But like then you can like watch +highlights from it and like actual like + + align:start position:0% +highlights from it and like actual like + + + align:start position:0% +highlights from it and like actual like +critics commentary on them and like kind + + align:start position:0% +critics commentary on them and like kind + + + align:start position:0% +critics commentary on them and like kind +of see like what that's doing both + + align:start position:0% +of see like what that's doing both + + + align:start position:0% +of see like what that's doing both +socially and also like from an artistic + + align:start position:0% +socially and also like from an artistic + + + align:start position:0% +socially and also like from an artistic +sense. Yeah. Do you use Pinterest or + + align:start position:0% +sense. Yeah. Do you use Pinterest or + + + align:start position:0% +sense. Yeah. Do you use Pinterest or +anything for sort of collecting your um + + align:start position:0% +anything for sort of collecting your um + + + align:start position:0% +anything for sort of collecting your um +I'm I've I had a social media + + align:start position:0% +I'm I've I had a social media + + + align:start position:0% +I'm I've I had a social media +problem YouTube so now I've kind of just + + align:start position:0% +problem YouTube so now I've kind of just + + + align:start position:0% +problem YouTube so now I've kind of just +continued into YouTube and stuff but I I + + align:start position:0% +continued into YouTube and stuff but I I + + + align:start position:0% +continued into YouTube and stuff but I I +do get to I guess reflect on it because + + align:start position:0% +do get to I guess reflect on it because + + + align:start position:0% +do get to I guess reflect on it because +I'm doing costume designs and stuff. Oh, + + align:start position:0% +I'm doing costume designs and stuff. Oh, + + + align:start position:0% +I'm doing costume designs and stuff. Oh, +cool. Yeah. My my my daughter is big + + align:start position:0% +cool. Yeah. My my my daughter is big + + + align:start position:0% +cool. Yeah. My my my daughter is big +into aesthetics of various kinds, craft + + align:start position:0% +into aesthetics of various kinds, craft + + + align:start position:0% +into aesthetics of various kinds, craft +things or design things. And Pinterest + + align:start position:0% +things or design things. And Pinterest + + + align:start position:0% +things or design things. And Pinterest +is like a big part of how she like she + + align:start position:0% +is like a big part of how she like she + + + align:start position:0% +is like a big part of how she like she +does the same kind of combing that you + + align:start position:0% +does the same kind of combing that you + + + align:start position:0% +does the same kind of combing that you +does, but she's deliberate about taking + + align:start position:0% +does, but she's deliberate about taking + + + align:start position:0% +does, but she's deliberate about taking +things that she likes and storing them + + align:start position:0% +things that she likes and storing them + + + align:start position:0% +things that she likes and storing them +and categorizing them and trying to make + + align:start position:0% +and categorizing them and trying to make + + + align:start position:0% +and categorizing them and trying to make +sense of them and things like + + align:start position:0% +sense of them and things like + + + align:start position:0% +sense of them and things like +that. Yeah. Dana. And then I was just + + align:start position:0% +that. Yeah. Dana. And then I was just + + + align:start position:0% +that. Yeah. Dana. And then I was just +going to say like just like another + + align:start position:0% +going to say like just like another + + + align:start position:0% +going to say like just like another +medium outside of like watching videos + + align:start position:0% +medium outside of like watching videos + + + align:start position:0% +medium outside of like watching videos +is just like online like so mine is like + + align:start position:0% +is just like online like so mine is like + + + align:start position:0% +is just like online like so mine is like +cooking. So like recipes and just like + + align:start position:0% +cooking. So like recipes and just like + + + align:start position:0% +cooking. So like recipes and just like +articles. Um, and then also like mine + + align:start position:0% +articles. Um, and then also like mine + + + align:start position:0% +articles. Um, and then also like mine +was like a little bit of TikTok just in + + align:start position:0% +was like a little bit of TikTok just in + + + align:start position:0% +was like a little bit of TikTok just in +like the one minute video of like you + + align:start position:0% +like the one minute video of like you + + + align:start position:0% +like the one minute video of like you +can cook this and it like isn't a + + align:start position:0% +can cook this and it like isn't a + + + align:start position:0% +can cook this and it like isn't a +professional chef showing you how to do + + align:start position:0% +professional chef showing you how to do + + + align:start position:0% +professional chef showing you how to do +it was cool to see that like oh like I + + align:start position:0% +it was cool to see that like oh like I + + + align:start position:0% +it was cool to see that like oh like I +can relate to that person so I can do + + align:start position:0% +can relate to that person so I can do + + + align:start position:0% +can relate to that person so I can do +it. Um, what what what are your favorite + + align:start position:0% +it. Um, what what what are your favorite + + + align:start position:0% +it. Um, what what what are your favorite +sort of recipe media or cooking media? + + align:start position:0% +sort of recipe media or cooking media? + + + align:start position:0% +sort of recipe media or cooking media? +Like how do you So I've only perfected + + align:start position:0% +Like how do you So I've only perfected + + + align:start position:0% +Like how do you So I've only perfected +one singular dish. Um, and it's + + align:start position:0% +one singular dish. Um, and it's + + + align:start position:0% +one singular dish. Um, and it's +scallops. Um, which is like a relatively + + align:start position:0% +scallops. Um, which is like a relatively + + + align:start position:0% +scallops. Um, which is like a relatively +hard thing, but like I'm scared to cook + + align:start position:0% +hard thing, but like I'm scared to cook + + + align:start position:0% +hard thing, but like I'm scared to cook +a chicken because I'm gonna give myself + + align:start position:0% +a chicken because I'm gonna give myself + + + align:start position:0% +a chicken because I'm gonna give myself +salmonilla a scallop. + + align:start position:0% +salmonilla a scallop. + + + align:start position:0% +salmonilla a scallop. +Yeah. So, my family joke is you only + + align:start position:0% +Yeah. So, my family joke is you only + + + align:start position:0% +Yeah. So, my family joke is you only +going to eat scallops for this. You're + + align:start position:0% +going to eat scallops for this. You're + + + align:start position:0% +going to eat scallops for this. You're +like, "Yeah, they're pretty good. + + align:start position:0% +like, "Yeah, they're pretty good. + + + align:start position:0% +like, "Yeah, they're pretty good. +They're healthy. Might be too many heavy + + align:start position:0% +They're healthy. Might be too many heavy + + + align:start position:0% +They're healthy. Might be too many heavy +metals if you do that your whole life or + + align:start position:0% +metals if you do that your whole life or + + + align:start position:0% +metals if you do that your whole life or +something like that." But yeah. Yeah. I + + align:start position:0% +something like that." But yeah. Yeah. I + + + align:start position:0% +something like that." But yeah. Yeah. I +don't know if bottom feeders are what + + align:start position:0% +don't know if bottom feeders are what + + + align:start position:0% +don't know if bottom feeders are what +you should do for your whole life, but + + align:start position:0% +you should do for your whole life, but + + + align:start position:0% +you should do for your whole life, but +that seems like seems like a good start. + + align:start position:0% +that seems like seems like a good start. + + + align:start position:0% +that seems like seems like a good start. +How about you, Armon? Uh I do mention + + align:start position:0% +How about you, Armon? Uh I do mention + + + align:start position:0% +How about you, Armon? Uh I do mention +this in our group but what came out from + + align:start position:0% +this in our group but what came out from + + + align:start position:0% +this in our group but what came out from +people talking like a lot of people + + align:start position:0% +people talking like a lot of people + + + align:start position:0% +people talking like a lot of people +relate is number file uh stream blue one + + align:start position:0% +relate is number file uh stream blue one + + + align:start position:0% +relate is number file uh stream blue one +brown this video I just put them in what + + align:start position:0% +brown this video I just put them in what + + + align:start position:0% +brown this video I just put them in what +is this it's a maths video they just + + align:start position:0% +is this it's a maths video they just + + + align:start position:0% +is this it's a maths video they just +tell you cool math stuff + + align:start position:0% +tell you cool math stuff + + + align:start position:0% +tell you cool math stuff +it's called number file number file + + align:start position:0% +it's called number file number file + + + align:start position:0% +it's called number file number file +street blue on brown those kind of + + align:start position:0% +street blue on brown those kind of + + + align:start position:0% +street blue on brown those kind of +videos so sometimes you learn that there + + align:start position:0% +videos so sometimes you learn that there + + + align:start position:0% +videos so sometimes you learn that there +is fractional dimension and you just be + + align:start position:0% +is fractional dimension and you just be + + + align:start position:0% +is fractional dimension and you just be +watching what that means And I watch + + align:start position:0% +watching what that means And I watch + + + align:start position:0% +watching what that means And I watch +those, too. So, they're really + + align:start position:0% +those, too. So, they're really + + + align:start position:0% +those, too. So, they're really +interested. Um, yeah. Who's who's the + + align:start position:0% +interested. Um, yeah. Who's who's the + + + align:start position:0% +interested. Um, yeah. Who's who's the +guy who came here a couple years ago for + + align:start position:0% +guy who came here a couple years ago for + + + align:start position:0% +guy who came here a couple years ago for +a graduation or convocation or + + align:start position:0% +a graduation or convocation or + + + align:start position:0% +a graduation or convocation or +something? Mark. Hm. Mark Robber. Mark + + align:start position:0% +something? Mark. Hm. Mark Robber. Mark + + + align:start position:0% +something? Mark. Hm. Mark Robber. Mark +Robber. Yep. Yeah. Yeah. He's sort of + + align:start position:0% +Robber. Yep. Yeah. Yeah. He's sort of + + + align:start position:0% +Robber. Yep. Yeah. Yeah. He's sort of +science YouTuber. Guy named Veritasium + + align:start position:0% +science YouTuber. Guy named Veritasium + + + align:start position:0% +science YouTuber. Guy named Veritasium +does uh does things like that too. Yeah. + + align:start position:0% +does uh does things like that too. Yeah. + + + align:start position:0% +does uh does things like that too. Yeah. +Yeah. Enormously uh popular and + + align:start position:0% +Yeah. Enormously uh popular and + + + align:start position:0% +Yeah. Enormously uh popular and +successful and things like that. Um I + + align:start position:0% +successful and things like that. Um I + + + align:start position:0% +successful and things like that. Um I +play a lot of computer games and I my + + align:start position:0% +play a lot of computer games and I my + + + align:start position:0% +play a lot of computer games and I my +life sort of overlaps. I don't know. + + align:start position:0% +life sort of overlaps. I don't know. + + + align:start position:0% +life sort of overlaps. I don't know. +computer games are like a couple of + + align:start position:0% +computer games are like a couple of + + + align:start position:0% +computer games are like a couple of +years older than me, but not by much. I + + align:start position:0% +years older than me, but not by much. I + + + align:start position:0% +years older than me, but not by much. I +mean, definitely some of my earliest + + align:start position:0% +mean, definitely some of my earliest + + + align:start position:0% +mean, definitely some of my earliest +memories are um games that would have + + align:start position:0% +memories are um games that would have + + + align:start position:0% +memories are um games that would have +been played off of like a cassette reel + + align:start position:0% +been played off of like a cassette reel + + + align:start position:0% +been played off of like a cassette reel +rather than any kind of rotary disc or + + align:start position:0% +rather than any kind of rotary disc or + + + align:start position:0% +rather than any kind of rotary disc or +or something like that. Um but another + + align:start position:0% +or something like that. Um but another + + + align:start position:0% +or something like that. Um but another +distinctive memory is that uh one of the + + align:start position:0% +distinctive memory is that uh one of the + + + align:start position:0% +distinctive memory is that uh one of the +first categories of games were these + + align:start position:0% +first categories of games were these + + + align:start position:0% +first categories of games were these +textbased games where you had to sort of + + align:start position:0% +textbased games where you had to sort of + + + align:start position:0% +textbased games where you had to sort of +enter prompts into a parser like open + + align:start position:0% +enter prompts into a parser like open + + + align:start position:0% +enter prompts into a parser like open +mailbox, go left, go right, walk in, you + + align:start position:0% +mailbox, go left, go right, walk in, you + + + align:start position:0% +mailbox, go left, go right, walk in, you +know, pick up key, put key and lock, + + align:start position:0% +know, pick up key, put key and lock, + + + align:start position:0% +know, pick up key, put key and lock, +those kinds of things. So, a lot of what + + align:start position:0% +those kinds of things. So, a lot of what + + + align:start position:0% +those kinds of things. So, a lot of what +you're doing Yeah. Come on in. um was + + align:start position:0% +you're doing Yeah. Come on in. um was + + + align:start position:0% +you're doing Yeah. Come on in. um was +kind of guessing like uh you know what + + align:start position:0% +kind of guessing like uh you know what + + + align:start position:0% +kind of guessing like uh you know what +what was the what was the right key term + + align:start position:0% +what was the what was the right key term + + + align:start position:0% +what was the what was the right key term +to put in to um to engage things and so + + align:start position:0% +to put in to um to engage things and so + + + align:start position:0% +to put in to um to engage things and so +actually a lot of these games Infocom + + align:start position:0% +actually a lot of these games Infocom + + + align:start position:0% +actually a lot of these games Infocom +was a company that sold a lot of them. + + align:start position:0% +was a company that sold a lot of them. + + + align:start position:0% +was a company that sold a lot of them. +Um the game companies would also publish + + align:start position:0% +Um the game companies would also publish + + + align:start position:0% +Um the game companies would also publish +a book and the book would have uh the + + align:start position:0% +a book and the book would have uh the + + + align:start position:0% +a book and the book would have uh the +answers to a whole bunch of things or + + align:start position:0% +answers to a whole bunch of things or + + + align:start position:0% +answers to a whole bunch of things or +like solution sets in invisible ink and + + align:start position:0% +like solution sets in invisible ink and + + + align:start position:0% +like solution sets in invisible ink and +so you had like a little uh um pen that + + align:start position:0% +so you had like a little uh um pen that + + + align:start position:0% +so you had like a little uh um pen that +came with it. And so when you decided + + align:start position:0% +came with it. And so when you decided + + + align:start position:0% +came with it. And so when you decided +that you had given up trying for + + align:start position:0% +that you had given up trying for + + + align:start position:0% +that you had given up trying for +yourself, you would uh you would cover + + align:start position:0% +yourself, you would uh you would cover + + + align:start position:0% +yourself, you would uh you would cover +the invisible ink with this pen that + + align:start position:0% +the invisible ink with this pen that + + + align:start position:0% +the invisible ink with this pen that +would reveal the sort of next clue and + + align:start position:0% +would reveal the sort of next clue and + + + align:start position:0% +would reveal the sort of next clue and +help you go on and so forth. Um and uh + + align:start position:0% +help you go on and so forth. Um and uh + + + align:start position:0% +help you go on and so forth. Um and uh +but now you know essentially every video + + align:start position:0% +but now you know essentially every video + + + align:start position:0% +but now you know essentially every video +game it like they almost instantly are + + align:start position:0% +game it like they almost instantly are + + + align:start position:0% +game it like they almost instantly are +created with a wiki that has you know + + align:start position:0% +created with a wiki that has you know + + + align:start position:0% +created with a wiki that has you know +every item in the game and what they do + + align:start position:0% +every item in the game and what they do + + + align:start position:0% +every item in the game and what they do +and where they go. Um a Reddit forum for + + align:start position:0% +and where they go. Um a Reddit forum for + + + align:start position:0% +and where they go. Um a Reddit forum for +conversation. um more recently Discord + + align:start position:0% +conversation. um more recently Discord + + + align:start position:0% +conversation. um more recently Discord +um pages, you know, that actually, you + + align:start position:0% +um pages, you know, that actually, you + + + align:start position:0% +um pages, you know, that actually, you +know, for smaller games can be kind of + + align:start position:0% +know, for smaller games can be kind of + + + align:start position:0% +know, for smaller games can be kind of +surprisingly intimate where you, you + + align:start position:0% +surprisingly intimate where you, you + + + align:start position:0% +surprisingly intimate where you, you +know, you really do feel like you're + + align:start position:0% +know, you really do feel like you're + + + align:start position:0% +know, you really do feel like you're +just like chatting with the guy who made + + align:start position:0% +just like chatting with the guy who made + + + align:start position:0% +just like chatting with the guy who made +the game. Um even if you know, there may + + align:start position:0% +the game. Um even if you know, there may + + + align:start position:0% +the game. Um even if you know, there may +not be responding to you directly, but + + align:start position:0% +not be responding to you directly, but + + + align:start position:0% +not be responding to you directly, but +they're certainly like responding to + + align:start position:0% +they're certainly like responding to + + + align:start position:0% +they're certainly like responding to +people that are there around with you + + align:start position:0% +people that are there around with you + + + align:start position:0% +people that are there around with you +and things like that, YouTube channels + + align:start position:0% +and things like that, YouTube channels + + + align:start position:0% +and things like that, YouTube channels +or all these kinds of things. Um yeah, I + + align:start position:0% +or all these kinds of things. Um yeah, I + + + align:start position:0% +or all these kinds of things. Um yeah, I +think there I think there's all kinds of + + align:start position:0% +think there I think there's all kinds of + + + align:start position:0% +think there I think there's all kinds of +ways. There ve there are very few + + align:start position:0% +ways. There ve there are very few + + + align:start position:0% +ways. There ve there are very few +people I think left in theorked world + + align:start position:0% +people I think left in theorked world + + + align:start position:0% +people I think left in theorked world +who don't have some kind of encounter + + align:start position:0% +who don't have some kind of encounter + + + align:start position:0% +who don't have some kind of encounter +with this sort of informal learning. Um + + align:start position:0% +with this sort of informal learning. Um + + + align:start position:0% +with this sort of informal learning. Um +I I I think you know just an enormous + + align:start position:0% +I I I think you know just an enormous + + + align:start position:0% +I I I think you know just an enormous +number of people in a very short period + + align:start position:0% +number of people in a very short period + + + align:start position:0% +number of people in a very short period +of time. I mean obviously there have + + align:start position:0% +of time. I mean obviously there have + + + align:start position:0% +of time. I mean obviously there have +always been people who do DIY kinds of + + align:start position:0% +always been people who do DIY kinds of + + + align:start position:0% +always been people who do DIY kinds of +things and stuff like that but the + + align:start position:0% +things and stuff like that but the + + + align:start position:0% +things and stuff like that but the +degree to which online resources has + + align:start position:0% +degree to which online resources has + + + align:start position:0% +degree to which online resources has +shaped those learning interactions um is + + align:start position:0% +shaped those learning interactions um is + + + align:start position:0% +shaped those learning interactions um is +a profound change over the last uh + + align:start position:0% +a profound change over the last uh + + + align:start position:0% +a profound change over the last uh +decade or two. The uh um and I think it + + align:start position:0% +decade or two. The uh um and I think it + + + align:start position:0% +decade or two. The uh um and I think it +I think it reminds us to do a few things + + align:start position:0% +I think it reminds us to do a few things + + + align:start position:0% +I think it reminds us to do a few things +that are useful. One is to um is to + + align:start position:0% +that are useful. One is to um is to + + + align:start position:0% +that are useful. One is to um is to +conceptualize learning really broadly. + + align:start position:0% +conceptualize learning really broadly. + + + align:start position:0% +conceptualize learning really broadly. +Um, you know, a lot of times that we + + align:start position:0% +Um, you know, a lot of times that we + + + align:start position:0% +Um, you know, a lot of times that we +think of learning, we sort of we pin it + + align:start position:0% +think of learning, we sort of we pin it + + + align:start position:0% +think of learning, we sort of we pin it +down in education, K12 education, + + align:start position:0% +down in education, K12 education, + + + align:start position:0% +down in education, K12 education, +college, things like that, but that's + + align:start position:0% +college, things like that, but that's + + + align:start position:0% +college, things like that, but that's +that's a relatively small part of + + align:start position:0% +that's a relatively small part of + + + align:start position:0% +that's a relatively small part of +people's lives. Um, people are learning + + align:start position:0% +people's lives. Um, people are learning + + + align:start position:0% +people's lives. Um, people are learning +all throughout their lives all the time. + + align:start position:0% +all throughout their lives all the time. + + + align:start position:0% +all throughout their lives all the time. +Um, people are developing new skills for + + align:start position:0% +Um, people are developing new skills for + + + align:start position:0% +Um, people are developing new skills for +work. They're developing new skills + + align:start position:0% +work. They're developing new skills + + + align:start position:0% +work. They're developing new skills +around their interests. They're they're + + align:start position:0% +around their interests. They're they're + + + align:start position:0% +around their interests. They're they're +they're pursuing passions. They're doing + + align:start position:0% +they're pursuing passions. They're doing + + + align:start position:0% +they're pursuing passions. They're doing +whatever else. And so think I think it's + + align:start position:0% +whatever else. And so think I think it's + + + align:start position:0% +whatever else. And so think I think it's +very helpful when thinking about online + + align:start position:0% +very helpful when thinking about online + + + align:start position:0% +very helpful when thinking about online +learning to be really open um to all + + align:start position:0% +learning to be really open um to all + + + align:start position:0% +learning to be really open um to all +these kinds of things. And then you know + + align:start position:0% +these kinds of things. And then you know + + + align:start position:0% +these kinds of things. And then you know +I I would say if there's a core argument + + align:start position:0% +I I would say if there's a core argument + + + align:start position:0% +I I would say if there's a core argument +in peerg guided learning at scale it's + + align:start position:0% +in peerg guided learning at scale it's + + + align:start position:0% +in peerg guided learning at scale it's +that these technologies have been so + + align:start position:0% +that these technologies have been so + + + align:start position:0% +that these technologies have been so +profound in changing the ways that we + + align:start position:0% +profound in changing the ways that we + + + align:start position:0% +profound in changing the ways that we +pursue learning outside of school and + + align:start position:0% +pursue learning outside of school and + + + align:start position:0% +pursue learning outside of school and +schools have proven to be institutions + + align:start position:0% +schools have proven to be institutions + + + align:start position:0% +schools have proven to be institutions +that are just remarkably resistant um to + + align:start position:0% +that are just remarkably resistant um to + + + align:start position:0% +that are just remarkably resistant um to +these forms of learning as well. Well, + + align:start position:0% +these forms of learning as well. Well, + + + align:start position:0% +these forms of learning as well. Well, +my hunch is most of you don't have an + + align:start position:0% +my hunch is most of you don't have an + + + align:start position:0% +my hunch is most of you don't have an +experience where you feel like, yeah, + + align:start position:0% +experience where you feel like, yeah, + + + align:start position:0% +experience where you feel like, yeah, +the kind of learning that I did in my + + align:start position:0% +the kind of learning that I did in my + + + align:start position:0% +the kind of learning that I did in my +eighth grade physics class was really + + align:start position:0% +eighth grade physics class was really + + + align:start position:0% +eighth grade physics class was really +just like the kind of learning that I + + align:start position:0% +just like the kind of learning that I + + + align:start position:0% +just like the kind of learning that I +did to learn photography or something + + align:start position:0% +did to learn photography or something + + + align:start position:0% +did to learn photography or something +like that. Um, there's something about + + align:start position:0% +like that. Um, there's something about + + + align:start position:0% +like that. Um, there's something about +schools um and the design and + + align:start position:0% +schools um and the design and + + + align:start position:0% +schools um and the design and +organization of schools that makes it + + align:start position:0% +organization of schools that makes it + + + align:start position:0% +organization of schools that makes it +really hard for these kinds of learning + + align:start position:0% +really hard for these kinds of learning + + + align:start position:0% +really hard for these kinds of learning +environments to make their way in. Um, I + + align:start position:0% +environments to make their way in. Um, I + + + align:start position:0% +environments to make their way in. Um, I +think a lot of what I want to share with + + align:start position:0% +think a lot of what I want to share with + + + align:start position:0% +think a lot of what I want to share with +you today are some of the most + + align:start position:0% +you today are some of the most + + + align:start position:0% +you today are some of the most +substantial efforts particularly in + + align:start position:0% +substantial efforts particularly in + + + align:start position:0% +substantial efforts particularly in +higher education to figure out how some + + align:start position:0% +higher education to figure out how some + + + align:start position:0% +higher education to figure out how some +of these approaches to um peer-guided + + align:start position:0% +of these approaches to um peer-guided + + + align:start position:0% +of these approaches to um peer-guided +learning at scale could make their way + + align:start position:0% +learning at scale could make their way + + + align:start position:0% +learning at scale could make their way +into formal institutions. Um I the ideas + + align:start position:0% +into formal institutions. Um I the ideas + + + align:start position:0% +into formal institutions. Um I the ideas +that I am presenting to you when I you + + align:start position:0% +that I am presenting to you when I you + + + align:start position:0% +that I am presenting to you when I you +know if I was talking about them 10 + + align:start position:0% +know if I was talking about them 10 + + + align:start position:0% +know if I was talking about them 10 +years ago I would have positioned them + + align:start position:0% +years ago I would have positioned them + + + align:start position:0% +years ago I would have positioned them +more as these are very viable ways in + + align:start position:0% +more as these are very viable ways in + + + align:start position:0% +more as these are very viable ways in +which at least higher education maybe a + + align:start position:0% +which at least higher education maybe a + + + align:start position:0% +which at least higher education maybe a +number of forms of education might + + align:start position:0% +number of forms of education might + + + align:start position:0% +number of forms of education might +substantially change in the next five or + + align:start position:0% +substantially change in the next five or + + + align:start position:0% +substantially change in the next five or +10 years. Um and I think I will I'm more + + align:start position:0% +10 years. Um and I think I will I'm more + + + align:start position:0% +10 years. Um and I think I will I'm more +likely to present you them today as an + + align:start position:0% +likely to present you them today as an + + + align:start position:0% +likely to present you them today as an +interesting dead end. um as a set of + + align:start position:0% +interesting dead end. um as a set of + + + align:start position:0% +interesting dead end. um as a set of +things that people were trying putting a + + align:start position:0% +things that people were trying putting a + + + align:start position:0% +things that people were trying putting a +lot of effort behind putting a lot of + + align:start position:0% +lot of effort behind putting a lot of + + + align:start position:0% +lot of effort behind putting a lot of +design behind and and really didn't have + + align:start position:0% +design behind and and really didn't have + + + align:start position:0% +design behind and and really didn't have +um much impact in how especially higher + + align:start position:0% +um much impact in how especially higher + + + align:start position:0% +um much impact in how especially higher +education Kate in how in how formal + + align:start position:0% +education Kate in how in how formal + + + align:start position:0% +education Kate in how in how formal +education of all kinds are organized um + + align:start position:0% +education of all kinds are organized um + + + align:start position:0% +education of all kinds are organized um +you know studying things that flop is is + + align:start position:0% +you know studying things that flop is is + + + align:start position:0% +you know studying things that flop is is +good we're going to come back to this a + + align:start position:0% +good we're going to come back to this a + + + align:start position:0% +good we're going to come back to this a +few different times studying things that + + align:start position:0% +few different times studying things that + + + align:start position:0% +few different times studying things that +flop is really important to figure out + + align:start position:0% +flop is really important to figure out + + + align:start position:0% +flop is really important to figure out +um why things work if you just study uh + + align:start position:0% +um why things work if you just study uh + + + align:start position:0% +um why things work if you just study uh +things that work um you actually don't + + align:start position:0% +things that work um you actually don't + + + align:start position:0% +things that work um you actually don't +know why they work you know the + + align:start position:0% +know why they work you know the + + + align:start position:0% +know why they work you know the +characteristics I have, but but there's + + align:start position:0% +characteristics I have, but but there's + + + align:start position:0% +characteristics I have, but but there's +lots of things that are in common + + align:start position:0% +lots of things that are in common + + + align:start position:0% +lots of things that are in common +between things that work and things that + + align:start position:0% +between things that work and things that + + + align:start position:0% +between things that work and things that +don't work. Um, and so that's what we'll + + align:start position:0% +don't work. Um, and so that's what we'll + + + align:start position:0% +don't work. Um, and so that's what we'll +uh we'll delve into some today. Um, + + align:start position:0% +uh we'll delve into some today. Um, + + + align:start position:0% +uh we'll delve into some today. Um, +maybe I'll talk for a little bit and + + align:start position:0% +maybe I'll talk for a little bit and + + + align:start position:0% +maybe I'll talk for a little bit and +then see what kind of thoughts you have. + + align:start position:0% +then see what kind of thoughts you have. + + + align:start position:0% +then see what kind of thoughts you have. +All right, so we are I think we did the + + align:start position:0% +All right, so we are I think we did the + + + align:start position:0% +All right, so we are I think we did the +Rainbow Loom story. We talked about this + + align:start position:0% +Rainbow Loom story. We talked about this + + + align:start position:0% +Rainbow Loom story. We talked about this +the other the other day. This is, you + + align:start position:0% +the other the other day. This is, you + + + align:start position:0% +the other the other day. This is, you +know, one I think iconic moment of, you + + align:start position:0% +know, one I think iconic moment of, you + + + align:start position:0% +know, one I think iconic moment of, you +know, the creation of a new craft + + align:start position:0% +know, the creation of a new craft + + + align:start position:0% +know, the creation of a new craft +generates um these these new kinds of + + align:start position:0% +generates um these these new kinds of + + + align:start position:0% +generates um these these new kinds of +communities. Um, this was from 2013. You + + align:start position:0% +communities. Um, this was from 2013. You + + + align:start position:0% +communities. Um, this was from 2013. You +know, low tech but high in creativity. + + align:start position:0% +know, low tech but high in creativity. + + + align:start position:0% +know, low tech but high in creativity. +The Rainbow Loom has kids hooked, + + align:start position:0% +The Rainbow Loom has kids hooked, + + + align:start position:0% +The Rainbow Loom has kids hooked, +spending hours after school and on + + align:start position:0% +spending hours after school and on + + + align:start position:0% +spending hours after school and on +weekends making bracelets, weaving + + align:start position:0% +weekends making bracelets, weaving + + + align:start position:0% +weekends making bracelets, weaving +together small, colorful rubber bands on + + align:start position:0% +together small, colorful rubber bands on + + + align:start position:0% +together small, colorful rubber bands on +a simple plastic loom. Um, and all of + + align:start position:0% +a simple plastic loom. Um, and all of + + + align:start position:0% +a simple plastic loom. Um, and all of +the um the narrative around Rainbow Loom + + align:start position:0% +the um the narrative around Rainbow Loom + + + align:start position:0% +the um the narrative around Rainbow Loom +was, man, look, we finally got kids off + + align:start position:0% +was, man, look, we finally got kids off + + + align:start position:0% +was, man, look, we finally got kids off +their phones. Like, we finally got kids + + align:start position:0% +their phones. Like, we finally got kids + + + align:start position:0% +their phones. Like, we finally got kids +in the real world connecting to one + + align:start position:0% +in the real world connecting to one + + + align:start position:0% +in the real world connecting to one +another. You know, this is I think 2013 + + align:start position:0% +another. You know, this is I think 2013 + + + align:start position:0% +another. You know, this is I think 2013 +that this is published right before + + align:start position:0% +that this is published right before + + + align:start position:0% +that this is published right before +Christmas. Um, but of course the kids + + align:start position:0% +Christmas. Um, but of course the kids + + + align:start position:0% +Christmas. Um, but of course the kids +were were on their phones the whole time + + align:start position:0% +were were on their phones the whole time + + + align:start position:0% +were were on their phones the whole time +that they were playing with Rainbow + + align:start position:0% +that they were playing with Rainbow + + + align:start position:0% +that they were playing with Rainbow +Loom. And so this is Ashley and Steph um + + align:start position:0% +Loom. And so this is Ashley and Steph um + + + align:start position:0% +Loom. And so this is Ashley and Steph um +who are these two girls, you know, who + + align:start position:0% +who are these two girls, you know, who + + + align:start position:0% +who are these two girls, you know, who +have 200, you know, a quarter of a + + align:start position:0% +have 200, you know, a quarter of a + + + align:start position:0% +have 200, you know, a quarter of a +million people subscribed to. Oh, this + + align:start position:0% +million people subscribed to. Oh, this + + + align:start position:0% +million people subscribed to. Oh, this +is Yeah. How to make a Rainbow Loom + + align:start position:0% +is Yeah. How to make a Rainbow Loom + + + align:start position:0% +is Yeah. How to make a Rainbow Loom +Starburst bracelet. When whenever I + + align:start position:0% +Starburst bracelet. When whenever I + + + align:start position:0% +Starburst bracelet. When whenever I +recorded this um 30 million views, um + + align:start position:0% +recorded this um 30 million views, um + + + align:start position:0% +recorded this um 30 million views, um +probably 10 times as many that were on + + align:start position:0% +probably 10 times as many that were on + + + align:start position:0% +probably 10 times as many that were on +the official Rainbow Loom um Starburst + + align:start position:0% +the official Rainbow Loom um Starburst + + + align:start position:0% +the official Rainbow Loom um Starburst +page that somehow these uh these two + + align:start position:0% +page that somehow these uh these two + + + align:start position:0% +page that somehow these uh these two +kids had um captivated. I I don't know. + + align:start position:0% +kids had um captivated. I I don't know. + + + align:start position:0% +kids had um captivated. I I don't know. +It's hard to say that it was millions of + + align:start position:0% +It's hard to say that it was millions of + + + align:start position:0% +It's hard to say that it was millions of +people because it actually could have + + align:start position:0% +people because it actually could have + + + align:start position:0% +people because it actually could have +been like a couple hundred thousand + + align:start position:0% +been like a couple hundred thousand + + + align:start position:0% +been like a couple hundred thousand +people each watch this like 10 or 20 + + align:start position:0% +people each watch this like 10 or 20 + + + align:start position:0% +people each watch this like 10 or 20 +times because it's super hard to make + + align:start position:0% +times because it's super hard to make + + + align:start position:0% +times because it's super hard to make +one of these bracelets. Um but uh um you + + align:start position:0% +one of these bracelets. Um but uh um you + + + align:start position:0% +one of these bracelets. Um but uh um you +know I think a a compelling example of + + align:start position:0% +know I think a a compelling example of + + + align:start position:0% +know I think a a compelling example of +how network learning was you know and + + align:start position:0% +how network learning was you know and + + + align:start position:0% +how network learning was you know and +and and something like this if you're my + + align:start position:0% +and and something like this if you're my + + + align:start position:0% +and and something like this if you're my +age you know looking at this in 2013 + + align:start position:0% +age you know looking at this in 2013 + + + align:start position:0% +age you know looking at this in 2013 +it's it's really hard to imagine + + align:start position:0% +it's it's really hard to imagine + + + align:start position:0% +it's it's really hard to imagine +something similar happening in 1990 or + + align:start position:0% +something similar happening in 1990 or + + + align:start position:0% +something similar happening in 1990 or +something like that. Like if someone had + + align:start position:0% +something like that. Like if someone had + + + align:start position:0% +something like that. Like if someone had +invented a new kind of craft you would + + align:start position:0% +invented a new kind of craft you would + + + align:start position:0% +invented a new kind of craft you would +have like had to go to a craft store. + + align:start position:0% +have like had to go to a craft store. + + + align:start position:0% +have like had to go to a craft store. +You would have had to join a club. be + + align:start position:0% +You would have had to join a club. be + + + align:start position:0% +You would have had to join a club. be +able to go to classes. There have to be + + align:start position:0% +able to go to classes. There have to be + + + align:start position:0% +able to go to classes. There have to be +a college club or something like that. + + align:start position:0% +a college club or something like that. + + + align:start position:0% +a college club or something like that. +Um there wouldn't, you know, I I mean, + + align:start position:0% +Um there wouldn't, you know, I I mean, + + + align:start position:0% +Um there wouldn't, you know, I I mean, +you know, maybe PBS would put on a + + align:start position:0% +you know, maybe PBS would put on a + + + align:start position:0% +you know, maybe PBS would put on a +television show about it. You'd have, + + align:start position:0% +television show about it. You'd have, + + + align:start position:0% +television show about it. You'd have, +you know, you could imagine like the Bob + + align:start position:0% +you know, you could imagine like the Bob + + + align:start position:0% +you know, you could imagine like the Bob +Ross of Rainbow Loom or something like + + align:start position:0% +Ross of Rainbow Loom or something like + + + align:start position:0% +Ross of Rainbow Loom or something like +that. Um but uh you know, um very hard + + align:start position:0% +that. Um but uh you know, um very hard + + + align:start position:0% +that. Um but uh you know, um very hard +to imagine the same kind of highly + + align:start position:0% +to imagine the same kind of highly + + + align:start position:0% +to imagine the same kind of highly +decentralized + + align:start position:0% +decentralized + + + align:start position:0% +decentralized +um uh mechanism by which learners + + align:start position:0% +um uh mechanism by which learners + + + align:start position:0% +um uh mechanism by which learners +connect themselves to each other. I + + align:start position:0% +connect themselves to each other. I + + + align:start position:0% +connect themselves to each other. I +think one of the things I'm going to ask + + align:start position:0% +think one of the things I'm going to ask + + + align:start position:0% +think one of the things I'm going to ask +you to um read for an upcoming week, I + + align:start position:0% +you to um read for an upcoming week, I + + + align:start position:0% +you to um read for an upcoming week, I +can't remember, it's next week. Um uh + + align:start position:0% +can't remember, it's next week. Um uh + + + align:start position:0% +can't remember, it's next week. Um uh +but this uh piece by Ivon Illich called + + align:start position:0% +but this uh piece by Ivon Illich called + + + align:start position:0% +but this uh piece by Ivon Illich called +Deschooling Society um I think it's + + align:start position:0% +Deschooling Society um I think it's + + + align:start position:0% +Deschooling Society um I think it's +written in the 1960s. Um and he he + + align:start position:0% +written in the 1960s. Um and he he + + + align:start position:0% +written in the 1960s. Um and he he +almost exactly with like the very dawn + + align:start position:0% +almost exactly with like the very dawn + + + align:start position:0% +almost exactly with like the very dawn +of computing and he predicts learning + + align:start position:0% +of computing and he predicts learning + + + align:start position:0% +of computing and he predicts learning +networks that that emerge like this. Um + + align:start position:0% +networks that that emerge like this. Um + + + align:start position:0% +networks that that emerge like this. Um +he says you know one day I mean he has a + + align:start position:0% +he says you know one day I mean he has a + + + align:start position:0% +he says you know one day I mean he has a +funny way of describing he says well you + + align:start position:0% +funny way of describing he says well you + + + align:start position:0% +funny way of describing he says well you +know one day there's going to be a bunch + + align:start position:0% +know one day there's going to be a bunch + + + align:start position:0% +know one day there's going to be a bunch +of learners um who write down the things + + align:start position:0% +of learners um who write down the things + + + align:start position:0% +of learners um who write down the things +they're interested in learning on punch + + align:start position:0% +they're interested in learning on punch + + + align:start position:0% +they're interested in learning on punch +cards because that's what computers at + + align:start position:0% +cards because that's what computers at + + + align:start position:0% +cards because that's what computers at +the time and there's going to be a bunch + + align:start position:0% +the time and there's going to be a bunch + + + align:start position:0% +the time and there's going to be a bunch +of experts who share their interests on + + align:start position:0% +of experts who share their interests on + + + align:start position:0% +of experts who share their interests on +punch cards and the computers are going + + align:start position:0% +punch cards and the computers are going + + + align:start position:0% +punch cards and the computers are going +to connect these punch cards together um + + align:start position:0% +to connect these punch cards together um + + + align:start position:0% +to connect these punch cards together um +and get people teaching and learning + + align:start position:0% +and get people teaching and learning + + + align:start position:0% +and get people teaching and learning +from one another and like we it turned + + align:start position:0% +from one another and like we it turned + + + align:start position:0% +from one another and like we it turned +out we had YouTube rather than punch + + align:start position:0% +out we had YouTube rather than punch + + + align:start position:0% +out we had YouTube rather than punch +cards but um it was a pretty similar + + align:start position:0% +cards but um it was a pretty similar + + + align:start position:0% +cards but um it was a pretty similar +kind of phenomenon um there are you know + + align:start position:0% +kind of phenomenon um there are you know + + + align:start position:0% +kind of phenomenon um there are you know +in in the in the 20 in the early 2010s, + + align:start position:0% +in in the in the 20 in the early 2010s, + + + align:start position:0% +in in the in the 20 in the early 2010s, +there were some people who were + + align:start position:0% +there were some people who were + + + align:start position:0% +there were some people who were +particularly enthusiastic about the + + align:start position:0% +particularly enthusiastic about the + + + align:start position:0% +particularly enthusiastic about the +fact, you know, so one thing about + + align:start position:0% +fact, you know, so one thing about + + + align:start position:0% +fact, you know, so one thing about +Rainbow Loom you could say is something + + align:start position:0% +Rainbow Loom you could say is something + + + align:start position:0% +Rainbow Loom you could say is something +like, well, all right, so some kids + + align:start position:0% +like, well, all right, so some kids + + + align:start position:0% +like, well, all right, so some kids +figured out how to make plastic + + align:start position:0% +figured out how to make plastic + + + align:start position:0% +figured out how to make plastic +bracelets. That's okay. Um, but there + + align:start position:0% +bracelets. That's okay. Um, but there + + + align:start position:0% +bracelets. That's okay. Um, but there +are people who achieve like elite levels + + align:start position:0% +are people who achieve like elite levels + + + align:start position:0% +are people who achieve like elite levels +of performance in a variety of different + + align:start position:0% +of performance in a variety of different + + + align:start position:0% +of performance in a variety of different +disciplines and domains by following the + + align:start position:0% +disciplines and domains by following the + + + align:start position:0% +disciplines and domains by following the +same kinds of practices that the Rainbow + + align:start position:0% +same kinds of practices that the Rainbow + + + align:start position:0% +same kinds of practices that the Rainbow +Kids, Rainbow Kids were using. So, this + + align:start position:0% +Kids, Rainbow Kids were using. So, this + + + align:start position:0% +Kids, Rainbow Kids were using. So, this +is a guy named Julius Jgo who, as I + + align:start position:0% +is a guy named Julius Jgo who, as I + + + align:start position:0% +is a guy named Julius Jgo who, as I +recall, won a silver medal in the + + align:start position:0% +recall, won a silver medal in the + + + align:start position:0% +recall, won a silver medal in the +Olympics. Um, he was from Kenya and he + + align:start position:0% +Olympics. Um, he was from Kenya and he + + + align:start position:0% +Olympics. Um, he was from Kenya and he +was a javelin thrower. There are no + + align:start position:0% +was a javelin thrower. There are no + + + align:start position:0% +was a javelin thrower. There are no +field athletes in Kenya. They're all + + align:start position:0% +field athletes in Kenya. They're all + + + align:start position:0% +field athletes in Kenya. They're all +track runners. Um, and for whatever + + align:start position:0% +track runners. Um, and for whatever + + + align:start position:0% +track runners. Um, and for whatever +reason, Julius Diego got it in his head + + align:start position:0% +reason, Julius Diego got it in his head + + + align:start position:0% +reason, Julius Diego got it in his head +like, I'm going to be a javelin thrower. + + align:start position:0% +like, I'm going to be a javelin thrower. + + + align:start position:0% +like, I'm going to be a javelin thrower. +Um, and uh, you know, I mean, here, you + + align:start position:0% +Um, and uh, you know, I mean, here, you + + + align:start position:0% +Um, and uh, you know, I mean, here, you +know, my coach is me and the YouTube + + align:start position:0% +know, my coach is me and the YouTube + + + align:start position:0% +know, my coach is me and the YouTube +videos. Um, and he became an elite, you + + align:start position:0% +videos. Um, and he became an elite, you + + + align:start position:0% +videos. Um, and he became an elite, you +know, globally recognized ath. I mean, + + align:start position:0% +know, globally recognized ath. I mean, + + + align:start position:0% +know, globally recognized ath. I mean, +there's a there's a there's a moment + + align:start position:0% +there's a there's a there's a moment + + + align:start position:0% +there's a there's a there's a moment +where this tips. there's a moment where + + align:start position:0% +where this tips. there's a moment where + + + align:start position:0% +where this tips. there's a moment where +he goes to um a track and field + + align:start position:0% +he goes to um a track and field + + + align:start position:0% +he goes to um a track and field +competition um you know he doesn't + + align:start position:0% +competition um you know he doesn't + + + align:start position:0% +competition um you know he doesn't +really have a coach and he throws a + + align:start position:0% +really have a coach and he throws a + + + align:start position:0% +really have a coach and he throws a +javelin pretty far and some people + + align:start position:0% +javelin pretty far and some people + + + align:start position:0% +javelin pretty far and some people +notice him and kind of take him under + + align:start position:0% +notice him and kind of take him under + + + align:start position:0% +notice him and kind of take him under +his wing and stuff like that. So it's + + align:start position:0% +his wing and stuff like that. So it's + + + align:start position:0% +his wing and stuff like that. So it's +not you know it's it's not just YouTube + + align:start position:0% +not you know it's it's not just YouTube + + + align:start position:0% +not you know it's it's not just YouTube +videos that get you entirely to um being + + align:start position:0% +videos that get you entirely to um being + + + align:start position:0% +videos that get you entirely to um being +the second best javelin thrower in the + + align:start position:0% +the second best javelin thrower in the + + + align:start position:0% +the second best javelin thrower in the +world. Um but uh but going quite a long + + align:start position:0% +world. Um but uh but going quite a long + + + align:start position:0% +world. Um but uh but going quite a long +way you know there's there's echoes of + + align:start position:0% +way you know there's there's echoes of + + + align:start position:0% +way you know there's there's echoes of +this of the story that I told you before + + align:start position:0% +this of the story that I told you before + + + align:start position:0% +this of the story that I told you before +of uh um Batush the boy genius of Ulan + + align:start position:0% +of uh um Batush the boy genius of Ulan + + + align:start position:0% +of uh um Batush the boy genius of Ulan +Batar the the kid who sort of discovered + + align:start position:0% +Batar the the kid who sort of discovered + + + align:start position:0% +Batar the the kid who sort of discovered +in Mongolia um through MITx and things + + align:start position:0% +in Mongolia um through MITx and things + + + align:start position:0% +in Mongolia um through MITx and things +like this the idea that these could have + + align:start position:0% +like this the idea that these could have + + + align:start position:0% +like this the idea that these could have +these profound democratizing effects + + align:start position:0% +these profound democratizing effects + + + align:start position:0% +these profound democratizing effects +like you don't you know you don't have + + align:start position:0% +like you don't you know you don't have + + + align:start position:0% +like you don't you know you don't have +to be um in in a country that has a + + align:start position:0% +to be um in in a country that has a + + + align:start position:0% +to be um in in a country that has a +really big track and field + + align:start position:0% +really big track and field + + + align:start position:0% +really big track and field +infrastructure um to be able to become a + + align:start position:0% +infrastructure um to be able to become a + + + align:start position:0% +infrastructure um to be able to become a +great athlete. You can do it anywhere + + align:start position:0% +great athlete. You can do it anywhere + + + align:start position:0% +great athlete. You can do it anywhere +because we have YouTube now. + + align:start position:0% +because we have YouTube now. + + + align:start position:0% +because we have YouTube now. +Um, so in I I was working for Harvard X + + align:start position:0% +Um, so in I I was working for Harvard X + + + align:start position:0% +Um, so in I I was working for Harvard X +in 2013. Um, + + align:start position:0% +in 2013. Um, + + + align:start position:0% +in 2013. Um, +uh, maybe I, you know, maybe I'll pause + + align:start position:0% +uh, maybe I, you know, maybe I'll pause + + + align:start position:0% +uh, maybe I, you know, maybe I'll pause +to tell this story, too. Well, I don't + + align:start position:0% +to tell this story, too. Well, I don't + + + align:start position:0% +to tell this story, too. Well, I don't +know what the right order is now that + + align:start position:0% +know what the right order is now that + + + align:start position:0% +know what the right order is now that +I'm inspired by it, but um there was + + align:start position:0% +I'm inspired by it, but um there was + + + align:start position:0% +I'm inspired by it, but um there was +this term massive open online courses + + align:start position:0% +this term massive open online courses + + + align:start position:0% +this term massive open online courses +and it actually was not originally + + align:start position:0% +and it actually was not originally + + + align:start position:0% +and it actually was not originally +applied to the courses that came out of + + align:start position:0% +applied to the courses that came out of + + + align:start position:0% +applied to the courses that came out of +Corsera um and edex and MITx and Udacity + + align:start position:0% +Corsera um and edex and MITx and Udacity + + + align:start position:0% +Corsera um and edex and MITx and Udacity +and things like that. There were a group + + align:start position:0% +and things like that. There were a group + + + align:start position:0% +and things like that. There were a group +of Canadian educators who 2008, 2009, + + align:start position:0% +of Canadian educators who 2008, 2009, + + + align:start position:0% +of Canadian educators who 2008, 2009, +2010, 2011 started building theseworked + + align:start position:0% +2010, 2011 started building theseworked + + + align:start position:0% +2010, 2011 started building theseworked +courses. Um, some of the I'll go more + + align:start position:0% +courses. Um, some of the I'll go more + + + align:start position:0% +courses. Um, some of the I'll go more +into the details of the network courses, + + align:start position:0% +into the details of the network courses, + + + align:start position:0% +into the details of the network courses, +but you would basically kind of create + + align:start position:0% +but you would basically kind of create + + + align:start position:0% +but you would basically kind of create +an online learning environment, have + + align:start position:0% +an online learning environment, have + + + align:start position:0% +an online learning environment, have +people create blogs, connect on Twitter, + + align:start position:0% +people create blogs, connect on Twitter, + + + align:start position:0% +people create blogs, connect on Twitter, +form social network connections with one + + align:start position:0% +form social network connections with one + + + align:start position:0% +form social network connections with one +another and sort of all be studying the + + align:start position:0% +another and sort of all be studying the + + + align:start position:0% +another and sort of all be studying the +same thing at the same time. Sometimes + + align:start position:0% +same thing at the same time. Sometimes + + + align:start position:0% +same thing at the same time. Sometimes +some of the people would be getting + + align:start position:0% +some of the people would be getting + + + align:start position:0% +some of the people would be getting +credit from some institution and other + + align:start position:0% +credit from some institution and other + + + align:start position:0% +credit from some institution and other +people would not be getting credit. They + + align:start position:0% +people would not be getting credit. They + + + align:start position:0% +people would not be getting credit. They +were all kind of openly being involved. + + align:start position:0% +were all kind of openly being involved. + + + align:start position:0% +were all kind of openly being involved. +You know, a few thousand people, + + align:start position:0% +You know, a few thousand people, + + + align:start position:0% +You know, a few thousand people, +probably the largest of these, um, + + align:start position:0% +probably the largest of these, um, + + + align:start position:0% +probably the largest of these, um, +signing up. And so there was actually a + + align:start position:0% +signing up. And so there was actually a + + + align:start position:0% +signing up. And so there was actually a +reporter who when um Edex and Corsera + + align:start position:0% +reporter who when um Edex and Corsera + + + align:start position:0% +reporter who when um Edex and Corsera +got started was trying to figure out + + align:start position:0% +got started was trying to figure out + + + align:start position:0% +got started was trying to figure out +what these things should be called. Um + + align:start position:0% +what these things should be called. Um + + + align:start position:0% +what these things should be called. Um +and somebody said like well these + + align:start position:0% +and somebody said like well these + + + align:start position:0% +and somebody said like well these +Canadian guys have these things called + + align:start position:0% +Canadian guys have these things called + + + align:start position:0% +Canadian guys have these things called +massive open online courses. Um and the + + align:start position:0% +massive open online courses. Um and the + + + align:start position:0% +massive open online courses. Um and the +name stuck but it stuck to describe + + align:start position:0% +name stuck but it stuck to describe + + + align:start position:0% +name stuck but it stuck to describe +something very very different. Um, one + + align:start position:0% +something very very different. Um, one + + + align:start position:0% +something very very different. Um, one +of the things that we recognized early + + align:start position:0% +of the things that we recognized early + + + align:start position:0% +of the things that we recognized early +on is that is that in the early days of + + align:start position:0% +on is that is that in the early days of + + + align:start position:0% +on is that is that in the early days of +people doing the massive open online + + align:start position:0% +people doing the massive open online + + + align:start position:0% +people doing the massive open online +courses that came out of Harvard and MIT + + align:start position:0% +courses that came out of Harvard and MIT + + + align:start position:0% +courses that came out of Harvard and MIT +is many of them were not just using the + + align:start position:0% +is many of them were not just using the + + + align:start position:0% +is many of them were not just using the +course materials that were being + + align:start position:0% +course materials that were being + + + align:start position:0% +course materials that were being +provided on these platforms, but they + + align:start position:0% +provided on these platforms, but they + + + align:start position:0% +provided on these platforms, but they +were using all kinds of other things. + + align:start position:0% +were using all kinds of other things. + + + align:start position:0% +were using all kinds of other things. +So, you'd ask people and they're like, + + align:start position:0% +So, you'd ask people and they're like, + + + align:start position:0% +So, you'd ask people and they're like, +you know, um, yeah, well, we're + + align:start position:0% +you know, um, yeah, well, we're + + + align:start position:0% +you know, um, yeah, well, we're +searching for all kinds of things that + + align:start position:0% +searching for all kinds of things that + + + align:start position:0% +searching for all kinds of things that +show up. We're reading like the + + align:start position:0% +show up. We're reading like the + + + align:start position:0% +show up. We're reading like the +Wikipedia entries about the things that + + align:start position:0% +Wikipedia entries about the things that + + + align:start position:0% +Wikipedia entries about the things that +show up in these classes. We're buying + + align:start position:0% +show up in these classes. We're buying + + + align:start position:0% +show up in these classes. We're buying +additional books that are around them. + + align:start position:0% +additional books that are around them. + + + align:start position:0% +additional books that are around them. +Um, we're looking for those books on + + align:start position:0% +Um, we're looking for those books on + + + align:start position:0% +Um, we're looking for those books on +Google books. We're joining Facebook + + align:start position:0% +Google books. We're joining Facebook + + + align:start position:0% +Google books. We're joining Facebook +groups of people who are studying these + + align:start position:0% +groups of people who are studying these + + + align:start position:0% +groups of people who are studying these +courses together and things like that. + + align:start position:0% +courses together and things like that. + + + align:start position:0% +courses together and things like that. +Um, and so the the the the barriers + + align:start position:0% +Um, and so the the the the barriers + + + align:start position:0% +Um, and so the the the the barriers +between these sort of instructorg guided + + align:start position:0% +between these sort of instructorg guided + + + align:start position:0% +between these sort of instructorg guided +learning at scale, these like highly + + align:start position:0% +learning at scale, these like highly + + + align:start position:0% +learning at scale, these like highly +structured learning management system + + align:start position:0% +structured learning management system + + + align:start position:0% +structured learning management system +kinds of things and the sort of informal + + align:start position:0% +kinds of things and the sort of informal + + + align:start position:0% +kinds of things and the sort of informal +world of people messing around on + + align:start position:0% +world of people messing around on + + + align:start position:0% +world of people messing around on +YouTube learning about stuff um sort of + + align:start position:0% +YouTube learning about stuff um sort of + + + align:start position:0% +YouTube learning about stuff um sort of +uh smooshed together. probably a bunch + + align:start position:0% +uh smooshed together. probably a bunch + + + align:start position:0% +uh smooshed together. probably a bunch +of you have some kind of experience of + + align:start position:0% +of you have some kind of experience of + + + align:start position:0% +of you have some kind of experience of +that in your classes too. I mean + + align:start position:0% +that in your classes too. I mean + + + align:start position:0% +that in your classes too. I mean +presumably all of you like are like when + + align:start position:0% +presumably all of you like are like when + + + align:start position:0% +presumably all of you like are like when +you don't understand something in class + + align:start position:0% +you don't understand something in class + + + align:start position:0% +you don't understand something in class +you're looking up online videos about it + + align:start position:0% +you're looking up online videos about it + + + align:start position:0% +you're looking up online videos about it +or you don't like the lecture and you + + align:start position:0% +or you don't like the lecture and you + + + align:start position:0% +or you don't like the lecture and you +know probably mostly in your technical + + align:start position:0% +know probably mostly in your technical + + + align:start position:0% +know probably mostly in your technical +classes you watch it from some other + + align:start position:0% +classes you watch it from some other + + + align:start position:0% +classes you watch it from some other +place. I don't know do any of you join + + align:start position:0% +place. I don't know do any of you join + + + align:start position:0% +place. I don't know do any of you join +groups or like find communities of + + align:start position:0% +groups or like find communities of + + + align:start position:0% +groups or like find communities of +people who are good at at solving + + align:start position:0% +people who are good at at solving + + + align:start position:0% +people who are good at at solving +problems and the things that you're + + align:start position:0% +problems and the things that you're + + + align:start position:0% +problems and the things that you're +interested in. + + align:start position:0% + + + + align:start position:0% + +One thing about being an MIT student is + + align:start position:0% +One thing about being an MIT student is + + + align:start position:0% +One thing about being an MIT student is +you can go on OCW if you miss a lecture + + align:start position:0% +you can go on OCW if you miss a lecture + + + align:start position:0% +you can go on OCW if you miss a lecture +or you don't understand the lecture you + + align:start position:0% +or you don't understand the lecture you + + + align:start position:0% +or you don't understand the lecture you +want to explain in a different way from + + align:start position:0% +want to explain in a different way from + + + align:start position:0% +want to explain in a different way from +a different professor just watch that + + align:start position:0% +a different professor just watch that + + + align:start position:0% +a different professor just watch that +same lecture which I've done before for + + align:start position:0% +same lecture which I've done before for + + + align:start position:0% +same lecture which I've done before for +some of my more technical classes. Yep. + + align:start position:0% +some of my more technical classes. Yep. + + + align:start position:0% +some of my more technical classes. Yep. +So yeah, so you can rewatch sort of past + + align:start position:0% +So yeah, so you can rewatch sort of past + + + align:start position:0% +So yeah, so you can rewatch sort of past +things. Some professors are sort of + + align:start position:0% +things. Some professors are sort of + + + align:start position:0% +things. Some professors are sort of +pretty explicit about that. You know, + + align:start position:0% +pretty explicit about that. You know, + + + align:start position:0% +pretty explicit about that. You know, +they'll be like, "Well, this is my + + align:start position:0% +they'll be like, "Well, this is my + + + align:start position:0% +they'll be like, "Well, this is my +lecture, but like somebody else filmed, + + align:start position:0% +lecture, but like somebody else filmed, + + + align:start position:0% +lecture, but like somebody else filmed, +you know, roughly the same course four + + align:start position:0% +you know, roughly the same course four + + + align:start position:0% +you know, roughly the same course four +years ago, and so you can watch all + + align:start position:0% +years ago, and so you can watch all + + + align:start position:0% +years ago, and so you can watch all +those things." Um, how many of your + + align:start position:0% +those things." Um, how many of your + + + align:start position:0% +those things." Um, how many of your +classes still use Piaza or some kind of + + align:start position:0% +classes still use Piaza or some kind of + + + align:start position:0% +classes still use Piaza or some kind of +discussion forum sort of things? Um, are + + align:start position:0% +discussion forum sort of things? Um, are + + + align:start position:0% +discussion forum sort of things? Um, are +the are the Piaza forms ever + + align:start position:0% +the are the Piaza forms ever + + + align:start position:0% +the are the Piaza forms ever +insufficient and then you go to Stack + + align:start position:0% +insufficient and then you go to Stack + + + align:start position:0% +insufficient and then you go to Stack +Overflow or to some other kind of maybe + + align:start position:0% +Overflow or to some other kind of maybe + + + align:start position:0% +Overflow or to some other kind of maybe +for your coding classes and things like + + align:start position:0% +for your coding classes and things like + + + align:start position:0% +for your coding classes and things like +that? I would say Piaza has like a weird + + align:start position:0% +that? I would say Piaza has like a weird + + + align:start position:0% +that? I would say Piaza has like a weird +social dynamic in itself. No, I want + + align:start position:0% +social dynamic in itself. No, I want + + + align:start position:0% +social dynamic in itself. No, I want +that now. Tell me more. + + align:start position:0% +that now. Tell me more. + + + align:start position:0% +that now. Tell me more. +I think it's like um I mean like + + align:start position:0% +I think it's like um I mean like + + + align:start position:0% +I think it's like um I mean like +obviously you can both do like anonymous + + align:start position:0% +obviously you can both do like anonymous + + + align:start position:0% +obviously you can both do like anonymous +questions and non-anmous question but + + align:start position:0% +questions and non-anmous question but + + + align:start position:0% +questions and non-anmous question but +usually it seems like you know it it + + align:start position:0% +usually it seems like you know it it + + + align:start position:0% +usually it seems like you know it it +really depends + + align:start position:0% +really depends + + + align:start position:0% +really depends +on a little bit on like who's really + + align:start position:0% +on a little bit on like who's really + + + align:start position:0% +on a little bit on like who's really +using it and also how responsive the + + align:start position:0% +using it and also how responsive the + + + align:start position:0% +using it and also how responsive the +faculty and stuff are and how they + + align:start position:0% +faculty and stuff are and how they + + + align:start position:0% +faculty and stuff are and how they +choose to respond because that I have + + align:start position:0% +choose to respond because that I have + + + align:start position:0% +choose to respond because that I have +been in a in quite a few classes where + + align:start position:0% +been in a in quite a few classes where + + + align:start position:0% +been in a in quite a few classes where +like + + align:start position:0% +like + + + align:start position:0% +like +log on and then it's like yes I had that + + align:start position:0% +log on and then it's like yes I had that + + + align:start position:0% +log on and then it's like yes I had that +question and they're like oh sorry we + + align:start position:0% +question and they're like oh sorry we + + + align:start position:0% +question and they're like oh sorry we +boarded the question weird but then I've + + align:start position:0% +boarded the question weird but then I've + + + align:start position:0% +boarded the question weird but then I've +also been quite a few classes where it's + + align:start position:0% +also been quite a few classes where it's + + + align:start position:0% +also been quite a few classes where it's +like they're asking this like super + + align:start position:0% +like they're asking this like super + + + align:start position:0% +like they're asking this like super +highlevel question about the lecture and + + align:start position:0% +highlevel question about the lecture and + + + align:start position:0% +highlevel question about the lecture and +then it kind of sets that expectation + + align:start position:0% +then it kind of sets that expectation + + + align:start position:0% +then it kind of sets that expectation +for the class especially if it's a + + align:start position:0% +for the class especially if it's a + + + align:start position:0% +for the class especially if it's a +larger class of like oh like my like + + align:start position:0% +larger class of like oh like my like + + + align:start position:0% +larger class of like oh like my like +quotequote dumb questions not going to + + align:start position:0% +quotequote dumb questions not going to + + + align:start position:0% +quotequote dumb questions not going to +be answered yeah it's not going to be + + align:start position:0% +be answered yeah it's not going to be + + + align:start position:0% +be answered yeah it's not going to be +kind of respected or things like that + + align:start position:0% +kind of respected or things like that + + + align:start position:0% +kind of respected or things like that +yeah you know And um I mean because + + align:start position:0% +yeah you know And um I mean because + + + align:start position:0% +yeah you know And um I mean because +these things are social in nature, I bet + + align:start position:0% +these things are social in nature, I bet + + + align:start position:0% +these things are social in nature, I bet +a lot of those things can be determined + + align:start position:0% +a lot of those things can be determined + + + align:start position:0% +a lot of those things can be determined +pretty early on by the actions of a + + align:start position:0% +pretty early on by the actions of a + + + align:start position:0% +pretty early on by the actions of a +couple of people. Um when we were + + align:start position:0% +couple of people. Um when we were + + + align:start position:0% +couple of people. Um when we were +studying Massive Women online courses, + + align:start position:0% +studying Massive Women online courses, + + + align:start position:0% +studying Massive Women online courses, +one of the things we found in the + + align:start position:0% +one of the things we found in the + + + align:start position:0% +one of the things we found in the +discussion forums, the largest threads, + + align:start position:0% +discussion forums, the largest threads, + + + align:start position:0% +discussion forums, the largest threads, +the most upvoted kinds of things were + + align:start position:0% +the most upvoted kinds of things were + + + align:start position:0% +the most upvoted kinds of things were +almost always amongst the very first + + align:start position:0% +almost always amongst the very first + + + align:start position:0% +almost always amongst the very first +topics cho like posted. So, so it wasn't + + align:start position:0% +topics cho like posted. So, so it wasn't + + + align:start position:0% +topics cho like posted. So, so it wasn't +like the forums were surfacing um like + + align:start position:0% +like the forums were surfacing um like + + + align:start position:0% +like the forums were surfacing um like +it wasn't like there was lots of ideas + + align:start position:0% +it wasn't like there was lots of ideas + + + align:start position:0% +it wasn't like there was lots of ideas +and the most interesting or important of + + align:start position:0% +and the most interesting or important of + + + align:start position:0% +and the most interesting or important of +those ideas were surfacing at the top. + + align:start position:0% +those ideas were surfacing at the top. + + + align:start position:0% +those ideas were surfacing at the top. +It was like somebody jumped in there + + align:start position:0% +It was like somebody jumped in there + + + align:start position:0% +It was like somebody jumped in there +first and then people started talking + + align:start position:0% +first and then people started talking + + + align:start position:0% +first and then people started talking +about those things, you know. Um and you + + align:start position:0% +about those things, you know. Um and you + + + align:start position:0% +about those things, you know. Um and you +could imagine you could imagine an + + align:start position:0% +could imagine you could imagine an + + + align:start position:0% +could imagine you could imagine an +alternate timeline of the exact same + + align:start position:0% +alternate timeline of the exact same + + + align:start position:0% +alternate timeline of the exact same +course you're in where the first two + + align:start position:0% +course you're in where the first two + + + align:start position:0% +course you're in where the first two +people to co post happen to just be + + align:start position:0% +people to co post happen to just be + + + align:start position:0% +people to co post happen to just be +people who are like I don't understand + + align:start position:0% +people who are like I don't understand + + + align:start position:0% +people who are like I don't understand +this really basic thing. Will someone + + align:start position:0% +this really basic thing. Will someone + + + align:start position:0% +this really basic thing. Will someone +explain it again? And the forums have + + align:start position:0% +explain it again? And the forums have + + + align:start position:0% +explain it again? And the forums have +sort of a whole different uh character + + align:start position:0% +sort of a whole different uh character + + + align:start position:0% +sort of a whole different uh character +to them. I mean to some extent I think + + align:start position:0% +to them. I mean to some extent I think + + + align:start position:0% +to them. I mean to some extent I think +of computer programming in particular as + + align:start position:0% +of computer programming in particular as + + + align:start position:0% +of computer programming in particular as +a field that depends upon this kind of + + align:start position:0% +a field that depends upon this kind of + + + align:start position:0% +a field that depends upon this kind of +informal learning that b like that + + align:start position:0% +informal learning that b like that + + + align:start position:0% +informal learning that b like that +basically no one knows enough about + + align:start position:0% +basically no one knows enough about + + + align:start position:0% +basically no one knows enough about +programming languages and how they + + align:start position:0% +programming languages and how they + + + align:start position:0% +programming languages and how they +operate and how they solve problems and + + align:start position:0% +operate and how they solve problems and + + + align:start position:0% +operate and how they solve problems and +so you you essentially can't do that + + align:start position:0% +so you you essentially can't do that + + + align:start position:0% +so you you essentially can't do that +profession if you can't figure out how + + align:start position:0% +profession if you can't figure out how + + + align:start position:0% +profession if you can't figure out how +to navigate all the online resources all + + align:start position:0% +to navigate all the online resources all + + + align:start position:0% +to navigate all the online resources all +online communities and things like that. + + align:start position:0% +online communities and things like that. + + + align:start position:0% +online communities and things like that. +And unusually um you can you can be pro + + align:start position:0% +And unusually um you can you can be pro + + + align:start position:0% +And unusually um you can you can be pro +be promoted and thrive in those + + align:start position:0% +be promoted and thrive in those + + + align:start position:0% +be promoted and thrive in those +communities through your participation + + align:start position:0% +communities through your participation + + + align:start position:0% +communities through your participation +in some of these kind of informal + + align:start position:0% +in some of these kind of informal + + + align:start position:0% +in some of these kind of informal +learning networks. You know you can be + + align:start position:0% +learning networks. You know you can be + + + align:start position:0% +learning networks. You know you can be +really active I mean in creating open + + align:start position:0% +really active I mean in creating open + + + align:start position:0% +really active I mean in creating open +source projects or just be a really + + align:start position:0% +source projects or just be a really + + + align:start position:0% +source projects or just be a really +active contributor to Stack Overflow or + + align:start position:0% +active contributor to Stack Overflow or + + + align:start position:0% +active contributor to Stack Overflow or +other kinds of communities like that get + + align:start position:0% +other kinds of communities like that get + + + align:start position:0% +other kinds of communities like that get +recognized for your contributions and + + align:start position:0% +recognized for your contributions and + + + align:start position:0% +recognized for your contributions and +have that translate into other kinds of + + align:start position:0% +have that translate into other kinds of + + + align:start position:0% +have that translate into other kinds of +opportunities. So um the boundaries + + align:start position:0% +opportunities. So um the boundaries + + + align:start position:0% +opportunities. So um the boundaries +between um there there are ways that I + + align:start position:0% +between um there there are ways that I + + + align:start position:0% +between um there there are ways that I +think these informal learning + + align:start position:0% +think these informal learning + + + align:start position:0% +think these informal learning +environments and formal learning + + align:start position:0% +environments and formal learning + + + align:start position:0% +environments and formal learning +environments the boundaries can permeate + + align:start position:0% +environments the boundaries can permeate + + + align:start position:0% +environments the boundaries can permeate +even if as we'll keep talking about like + + align:start position:0% +even if as we'll keep talking about like + + + align:start position:0% +even if as we'll keep talking about like +just trying to take the whole informal + + align:start position:0% +just trying to take the whole informal + + + align:start position:0% +just trying to take the whole informal +peer guided learning infrastructure and + + align:start position:0% +peer guided learning infrastructure and + + + align:start position:0% +peer guided learning infrastructure and +bring it into schools seems not to to + + align:start position:0% +bring it into schools seems not to to + + + align:start position:0% +bring it into schools seems not to to +work pretty well. + + align:start position:0% +work pretty well. + + + align:start position:0% +work pretty well. +Um uh you know I think one of the + + align:start position:0% +Um uh you know I think one of the + + + align:start position:0% +Um uh you know I think one of the +actually one of the most compelling + + align:start position:0% +actually one of the most compelling + + + align:start position:0% +actually one of the most compelling +reasons for integrating technology into + + align:start position:0% +reasons for integrating technology into + + + align:start position:0% +reasons for integrating technology into +people's school learning at all is the + + align:start position:0% +people's school learning at all is the + + + align:start position:0% +people's school learning at all is the +idea that actually for most of your + + align:start position:0% +idea that actually for most of your + + + align:start position:0% +idea that actually for most of your +lives the kind of learning that you do + + align:start position:0% +lives the kind of learning that you do + + + align:start position:0% +lives the kind of learning that you do +will look more like the learning around + + align:start position:0% +will look more like the learning around + + + align:start position:0% +will look more like the learning around +your hobbies than it does look like the + + align:start position:0% +your hobbies than it does look like the + + + align:start position:0% +your hobbies than it does look like the +learning in your classes. You know in in + + align:start position:0% +learning in your classes. You know in in + + + align:start position:0% +learning in your classes. You know in in +the next couple of years some of you + + align:start position:0% +the next couple of years some of you + + + align:start position:0% +the next couple of years some of you +will keep taking classes for a long long + + align:start position:0% +will keep taking classes for a long long + + + align:start position:0% +will keep taking classes for a long long +time but most of you will probably stop + + align:start position:0% +time but most of you will probably stop + + + align:start position:0% +time but most of you will probably stop +um or take them only infrequently. You + + align:start position:0% +um or take them only infrequently. You + + + align:start position:0% +um or take them only infrequently. You +will probably however continue um to + + align:start position:0% +will probably however continue um to + + + align:start position:0% +will probably however continue um to +participate in these online learning + + align:start position:0% +participate in these online learning + + + align:start position:0% +participate in these online learning +communities. To me it raises really + + align:start position:0% +communities. To me it raises really + + + align:start position:0% +communities. To me it raises really +interesting questions like you know what + + align:start position:0% +interesting questions like you know what + + + align:start position:0% +interesting questions like you know what +responsibility does a school have for + + align:start position:0% +responsibility does a school have for + + + align:start position:0% +responsibility does a school have for +helping people become really good um you + + align:start position:0% +helping people become really good um you + + + align:start position:0% +helping people become really good um you +know at learning cooking through playing + + align:start position:0% +know at learning cooking through playing + + + align:start position:0% +know at learning cooking through playing +with recipes the way Dana described or + + align:start position:0% +with recipes the way Dana described or + + + align:start position:0% +with recipes the way Dana described or +or learning photography um through + + align:start position:0% +or learning photography um through + + + align:start position:0% +or learning photography um through +online forums or music through uh online + + align:start position:0% +online forums or music through uh online + + + align:start position:0% +online forums or music through uh online +videos in the way that that Jiren and + + align:start position:0% +videos in the way that that Jiren and + + + align:start position:0% +videos in the way that that Jiren and +Omar described. like what what would + + align:start position:0% +Omar described. like what what would + + + align:start position:0% +Omar described. like what what would +what would a K12 education look like if + + align:start position:0% +what would a K12 education look like if + + + align:start position:0% +what would a K12 education look like if +someone left school and they were like, + + align:start position:0% +someone left school and they were like, + + + align:start position:0% +someone left school and they were like, +I'm totally prepared to teach myself + + align:start position:0% +I'm totally prepared to teach myself + + + align:start position:0% +I'm totally prepared to teach myself +stuff by engaging these online + + align:start position:0% +stuff by engaging these online + + + align:start position:0% +stuff by engaging these online +communities because I've had a bunch of + + align:start position:0% +communities because I've had a bunch of + + + align:start position:0% +communities because I've had a bunch of +practice in those sorts of things. What + + align:start position:0% +practice in those sorts of things. What + + + align:start position:0% +practice in those sorts of things. What +would a what would a college education + + align:start position:0% +would a what would a college education + + + align:start position:0% +would a what would a college education +look like if it was good at that? I feel + + align:start position:0% +look like if it was good at that? I feel + + + align:start position:0% +look like if it was good at that? I feel +like that's like such an interesting + + align:start position:0% +like that's like such an interesting + + + align:start position:0% +like that's like such an interesting +point because I like think back to a + + align:start position:0% +point because I like think back to a + + + align:start position:0% +point because I like think back to a +conversation I had with my mom where she + + align:start position:0% +conversation I had with my mom where she + + + align:start position:0% +conversation I had with my mom where she +like grew up and was out of college or + + align:start position:0% +like grew up and was out of college or + + + align:start position:0% +like grew up and was out of college or +out of high school like right before the + + align:start position:0% +out of high school like right before the + + + align:start position:0% +out of high school like right before the +like really dawn of like computer + + align:start position:0% +like really dawn of like computer + + + align:start position:0% +like really dawn of like computer +classes in high school and middle school + + align:start position:0% +classes in high school and middle school + + + align:start position:0% +classes in high school and middle school +and like in middle school so like + + align:start position:0% +and like in middle school so like + + + align:start position:0% +and like in middle school so like +rudimentary to us we like learn how to + + align:start position:0% +rudimentary to us we like learn how to + + + align:start position:0% +rudimentary to us we like learn how to +use an Excel sheet and like just learn + + align:start position:0% +use an Excel sheet and like just learn + + + align:start position:0% +use an Excel sheet and like just learn +how to like Google things um and like a + + align:start position:0% +how to like Google things um and like a + + + align:start position:0% +how to like Google things um and like a +lot of just like the super basic skills + + align:start position:0% +lot of just like the super basic skills + + + align:start position:0% +lot of just like the super basic skills +like how to type on a computer a + + align:start position:0% +like how to type on a computer a + + + align:start position:0% +like how to type on a computer a +computer like keyboard that she doesn't + + align:start position:0% +computer like keyboard that she doesn't + + + align:start position:0% +computer like keyboard that she doesn't +know how to do and it almost seems like + + align:start position:0% +know how to do and it almost seems like + + + align:start position:0% +know how to do and it almost seems like +the next generation will like leave + + align:start position:0% +the next generation will like leave + + + align:start position:0% +the next generation will like leave +computer classes like knowing how to + + align:start position:0% +computer classes like knowing how to + + + align:start position:0% +computer classes like knowing how to +navigate these sites and like then all + + align:start position:0% +navigate these sites and like then all + + + align:start position:0% +navigate these sites and like then all +the stuff that I had to learn on my own + + align:start position:0% +the stuff that I had to learn on my own + + + align:start position:0% +the stuff that I had to learn on my own +like maybe I'm asking my kids like where + + align:start position:0% +like maybe I'm asking my kids like where + + + align:start position:0% +like maybe I'm asking my kids like where +did you learn that and they're just like + + align:start position:0% +did you learn that and they're just like + + + align:start position:0% +did you learn that and they're just like +in school. Um there was a phrase that + + align:start position:0% +in school. Um there was a phrase that + + + align:start position:0% +in school. Um there was a phrase that +was used for a number of years that was + + align:start position:0% +was used for a number of years that was + + + align:start position:0% +was used for a number of years that was +called digital native. Um the idea maybe + + align:start position:0% +called digital native. Um the idea maybe + + + align:start position:0% +called digital native. Um the idea maybe +maybe a more common you know phrase that + + align:start position:0% +maybe a more common you know phrase that + + + align:start position:0% +maybe a more common you know phrase that +you'll hear probably in the next few + + align:start position:0% +you'll hear probably in the next few + + + align:start position:0% +you'll hear probably in the next few +years will be something like AI native. + + align:start position:0% +years will be something like AI native. + + + align:start position:0% +years will be something like AI native. +um the idea that like what's the + + align:start position:0% +um the idea that like what's the + + + align:start position:0% +um the idea that like what's the +difference between having to learn + + align:start position:0% +difference between having to learn + + + align:start position:0% +difference between having to learn +something by by having it come into you + + align:start position:0% +something by by having it come into you + + + align:start position:0% +something by by having it come into you +into your into your life versus like + + align:start position:0% +into your into your life versus like + + + align:start position:0% +into your into your life versus like +having it be something that you kind of + + align:start position:0% +having it be something that you kind of + + + align:start position:0% +having it be something that you kind of +grow up with all the time. There's + + align:start position:0% +grow up with all the time. There's + + + align:start position:0% +grow up with all the time. There's +actually a bunch of good evidence that + + align:start position:0% +actually a bunch of good evidence that + + + align:start position:0% +actually a bunch of good evidence that +in fact that digital natives that young + + align:start position:0% +in fact that digital natives that young + + + align:start position:0% +in fact that digital natives that young +people are actually not that much better + + align:start position:0% +people are actually not that much better + + + align:start position:0% +people are actually not that much better +at using technology especially learning + + align:start position:0% +at using technology especially learning + + + align:start position:0% +at using technology especially learning +things than older folks. Um you know + + align:start position:0% +things than older folks. Um you know + + + align:start position:0% +things than older folks. Um you know +young people in schools are usually + + align:start position:0% +young people in schools are usually + + + align:start position:0% +young people in schools are usually +pretty good at doing certain kinds of + + align:start position:0% +pretty good at doing certain kinds of + + + align:start position:0% +pretty good at doing certain kinds of +technology mediated things but the + + align:start position:0% +technology mediated things but the + + + align:start position:0% +technology mediated things but the +things that are most helpful for + + align:start position:0% +things that are most helpful for + + + align:start position:0% +things that are most helpful for +learning they're often no better at than + + align:start position:0% +learning they're often no better at than + + + align:start position:0% +learning they're often no better at than +sort of anybody else. Um although I' + + align:start position:0% +sort of anybody else. Um although I' + + + align:start position:0% +sort of anybody else. Um although I' +I've always liked the idea you know one + + align:start position:0% +I've always liked the idea you know one + + + align:start position:0% +I've always liked the idea you know one +of the things that comes along with the + + align:start position:0% +of the things that comes along with the + + + align:start position:0% +of the things that comes along with the +idea of immigration of digital natives + + align:start position:0% +idea of immigration of digital natives + + + align:start position:0% +idea of immigration of digital natives +and so digital immigrants and digital + + align:start position:0% +and so digital immigrants and digital + + + align:start position:0% +and so digital immigrants and digital +natives is that uh um you know second + + align:start position:0% +natives is that uh um you know second + + + align:start position:0% +natives is that uh um you know second +generation immigrants are always taking + + align:start position:0% +generation immigrants are always taking + + + align:start position:0% +generation immigrants are always taking +on new responsibilities for teaching + + align:start position:0% +on new responsibilities for teaching + + + align:start position:0% +on new responsibilities for teaching +their first generation parents about + + align:start position:0% +their first generation parents about + + + align:start position:0% +their first generation parents about +things you know you like you you grow up + + align:start position:0% +things you know you like you you grow up + + + align:start position:0% +things you know you like you you grow up +in a country and you learn the language + + align:start position:0% +in a country and you learn the language + + + align:start position:0% +in a country and you learn the language +you learn the culture you know other + + align:start position:0% +you learn the culture you know other + + + align:start position:0% +you learn the culture you know other +kinds of things that you sort of have to + + align:start position:0% +kinds of things that you sort of have to + + + align:start position:0% +kinds of things that you sort of have to +explain to your parents so there's + + align:start position:0% +explain to your parents so there's + + + align:start position:0% +explain to your parents so there's +something kind of nice about um that + + align:start position:0% +something kind of nice about um that + + + align:start position:0% +something kind of nice about um that +metaphor carrying over + + align:start position:0% +metaphor carrying over + + + align:start position:0% +metaphor carrying over +um something that I know state of + + align:start position:0% +um something that I know state of + + + align:start position:0% +um something that I know state of +Massachusetts is doing is um I don't + + align:start position:0% +Massachusetts is doing is um I don't + + + align:start position:0% +Massachusetts is doing is um I don't +know if I completely agree with it um + + align:start position:0% +know if I completely agree with it um + + + align:start position:0% +know if I completely agree with it um +blending computer science and computer + + align:start position:0% +blending computer science and computer + + + align:start position:0% +blending computer science and computer +literacy together. I do think that + + align:start position:0% +literacy together. I do think that + + + align:start position:0% +literacy together. I do think that +teaching computer literacy is of utmost + + align:start position:0% +teaching computer literacy is of utmost + + + align:start position:0% +teaching computer literacy is of utmost +importance. Um I credit a lot of my um + + align:start position:0% +importance. Um I credit a lot of my um + + + align:start position:0% +importance. Um I credit a lot of my um +computer literacy to my seventh grade + + align:start position:0% +computer literacy to my seventh grade + + + align:start position:0% +computer literacy to my seventh grade +seventh and eighth grade technology + + align:start position:0% +seventh and eighth grade technology + + + align:start position:0% +seventh and eighth grade technology +teacher. Um you know the link that I use + + align:start position:0% +teacher. Um you know the link that I use + + + align:start position:0% +teacher. Um you know the link that I use +now was created back in seventh grade. + + align:start position:0% +now was created back in seventh grade. + + + align:start position:0% +now was created back in seventh grade. +use is the very same account and he was + + align:start position:0% +use is the very same account and he was + + + align:start position:0% +use is the very same account and he was +the one who got me um I think I + + align:start position:0% +the one who got me um I think I + + + align:start position:0% +the one who got me um I think I +mentioned the typing lessons like the + + align:start position:0% +mentioned the typing lessons like the + + + align:start position:0% +mentioned the typing lessons like the +beginning of the class that's where I + + align:start position:0% +beginning of the class that's where I + + + align:start position:0% +beginning of the class that's where I +learned how to type um that's where I + + align:start position:0% +learned how to type um that's where I + + + align:start position:0% +learned how to type um that's where I +learned how to um create a portfolio + + align:start position:0% +learned how to um create a portfolio + + + align:start position:0% +learned how to um create a portfolio +create an online website um do like + + align:start position:0% +create an online website um do like + + + align:start position:0% +create an online website um do like +individual kind of research and like + + align:start position:0% +individual kind of research and like + + + align:start position:0% +individual kind of research and like +create a project on something that I'm + + align:start position:0% +create a project on something that I'm + + + align:start position:0% +create a project on something that I'm +interested about um and I think creating + + align:start position:0% +interested about um and I think creating + + + align:start position:0% +interested about um and I think creating +projects on something that's is like + + align:start position:0% +projects on something that's is like + + + align:start position:0% +projects on something that's is like +personal to someone within a K through + + align:start position:0% +personal to someone within a K through + + + align:start position:0% +personal to someone within a K through +12 um lesson is really important for + + align:start position:0% +12 um lesson is really important for + + + align:start position:0% +12 um lesson is really important for +teaching them how to like conduct + + align:start position:0% +teaching them how to like conduct + + + align:start position:0% +teaching them how to like conduct +research + + align:start position:0% +research + + + align:start position:0% +research +take notes and uh come up with + + align:start position:0% +take notes and uh come up with + + + align:start position:0% +take notes and uh come up with +conclusions on what they've um gone up + + align:start position:0% +conclusions on what they've um gone up + + + align:start position:0% +conclusions on what they've um gone up +and looked for online. And a constant + + align:start position:0% +and looked for online. And a constant + + + align:start position:0% +and looked for online. And a constant +challenge educators have is what new + + align:start position:0% +challenge educators have is what new + + + align:start position:0% +challenge educators have is what new +things are actually worth investing + + align:start position:0% +things are actually worth investing + + + align:start position:0% +things are actually worth investing +additional discretionary time in. I + + align:start position:0% +additional discretionary time in. I + + + align:start position:0% +additional discretionary time in. I +mean, there were, you know, plenty of + + align:start position:0% +mean, there were, you know, plenty of + + + align:start position:0% +mean, there were, you know, plenty of +folks 10 years ago who said, man, it's + + align:start position:0% +folks 10 years ago who said, man, it's + + + align:start position:0% +folks 10 years ago who said, man, it's +incredibly important. Every high + + align:start position:0% +incredibly important. Every high + + + align:start position:0% +incredibly important. Every high +schooler should complete a MOO. MOUKs + + align:start position:0% +schooler should complete a MOO. MOUKs + + + align:start position:0% +schooler should complete a MOO. MOUKs +are going to be absolutely essential to + + align:start position:0% +are going to be absolutely essential to + + + align:start position:0% +are going to be absolutely essential to +how people learn and finish higher + + align:start position:0% +how people learn and finish higher + + + align:start position:0% +how people learn and finish higher +education in the future. If you can't do + + align:start position:0% +education in the future. If you can't do + + + align:start position:0% +education in the future. If you can't do +a MOO, you're really going to be left + + align:start position:0% +a MOO, you're really going to be left + + + align:start position:0% +a MOO, you're really going to be left +out. It's like, well, maybe not so much. + + align:start position:0% +out. It's like, well, maybe not so much. + + + align:start position:0% +out. It's like, well, maybe not so much. +turned like a LinkedIn profile however + + align:start position:0% +turned like a LinkedIn profile however + + + align:start position:0% +turned like a LinkedIn profile however +many years later still seems like a + + align:start position:0% +many years later still seems like a + + + align:start position:0% +many years later still seems like a +pretty handy thing to have. There is no + + align:start position:0% +pretty handy thing to have. There is no + + + align:start position:0% +pretty handy thing to have. There is no +reason 10 years ago that you could it's + + align:start position:0% +reason 10 years ago that you could it's + + + align:start position:0% +reason 10 years ago that you could it's +very easy to imagine a world where + + align:start position:0% +very easy to imagine a world where + + + align:start position:0% +very easy to imagine a world where +LinkedIn got replaced by something else + + align:start position:0% +LinkedIn got replaced by something else + + + align:start position:0% +LinkedIn got replaced by something else +entirely and mukes were super important + + align:start position:0% +entirely and mukes were super important + + + align:start position:0% +entirely and mukes were super important +like in 2013 the success paths of those + + align:start position:0% +like in 2013 the success paths of those + + + align:start position:0% +like in 2013 the success paths of those +things were not at all predictable. Um + + align:start position:0% +things were not at all predictable. Um + + + align:start position:0% +things were not at all predictable. Um +uh educators are super anxious about I I + + align:start position:0% +uh educators are super anxious about I I + + + align:start position:0% +uh educators are super anxious about I I +just gave it Aaron came to this + + align:start position:0% +just gave it Aaron came to this + + + align:start position:0% +just gave it Aaron came to this +conference with me. I gave a talk to a + + align:start position:0% +conference with me. I gave a talk to a + + + align:start position:0% +conference with me. I gave a talk to a +bunch of educators about AI and + + align:start position:0% +bunch of educators about AI and + + + align:start position:0% +bunch of educators about AI and +education on Monday. Um and there's a + + align:start position:0% +education on Monday. Um and there's a + + + align:start position:0% +education on Monday. Um and there's a +ton of anxiety about like how important + + align:start position:0% +ton of anxiety about like how important + + + align:start position:0% +ton of anxiety about like how important +are these things? What what do we not + + align:start position:0% +are these things? What what do we not + + + align:start position:0% +are these things? What what do we not +need? Does it make sense to teach kids + + align:start position:0% +need? Does it make sense to teach kids + + + align:start position:0% +need? Does it make sense to teach kids +the same way to search anymore? If you + + align:start position:0% +the same way to search anymore? If you + + + align:start position:0% +the same way to search anymore? If you +know, AI agents are just going to answer + + align:start position:0% +know, AI agents are just going to answer + + + align:start position:0% +know, AI agents are just going to answer +our questions for us or do we is it more + + align:start position:0% +our questions for us or do we is it more + + + align:start position:0% +our questions for us or do we is it more +important to be able to do that because + + align:start position:0% +important to be able to do that because + + + align:start position:0% +important to be able to do that because +the AI agents are going to say nonsense + + align:start position:0% +the AI agents are going to say nonsense + + + align:start position:0% +the AI agents are going to say nonsense +to us? Um all these all these kinds of + + align:start position:0% +to us? Um all these all these kinds of + + + align:start position:0% +to us? Um all these all these kinds of +things. Yeah. Ty, in that Oh, sorry. In + + align:start position:0% +things. Yeah. Ty, in that Oh, sorry. In + + + align:start position:0% +things. Yeah. Ty, in that Oh, sorry. In +that regard, like do you consider AI a + + align:start position:0% +that regard, like do you consider AI a + + + align:start position:0% +that regard, like do you consider AI a +form of like peer learning because it's + + align:start position:0% +form of like peer learning because it's + + + align:start position:0% +form of like peer learning because it's +been trained on pure community like + + align:start position:0% +been trained on pure community like + + + align:start position:0% +been trained on pure community like +stack overflow, all these other things. + + align:start position:0% +stack overflow, all these other things. + + + align:start position:0% +stack overflow, all these other things. +Question. Oh, so my first thing about AI + + align:start position:0% +Question. Oh, so my first thing about AI + + + align:start position:0% +Question. Oh, so my first thing about AI +um uh I was giving a talk with Jim Waldo + + align:start position:0% +um uh I was giving a talk with Jim Waldo + + + align:start position:0% +um uh I was giving a talk with Jim Waldo +um who's the who was the chief technical + + align:start position:0% +um who's the who was the chief technical + + + align:start position:0% +um who's the who was the chief technical +officer at Harvard. He's a neat guy um + + align:start position:0% +officer at Harvard. He's a neat guy um + + + align:start position:0% +officer at Harvard. He's a neat guy um +because he got he got a PhD in + + align:start position:0% +because he got he got a PhD in + + + align:start position:0% +because he got he got a PhD in +philosophy about 40 years ago then went + + align:start position:0% +philosophy about 40 years ago then went + + + align:start position:0% +philosophy about 40 years ago then went +and worked at Oracle, helped write Java. + + align:start position:0% +and worked at Oracle, helped write Java. + + + align:start position:0% +and worked at Oracle, helped write Java. +If you have an Android phone, you're + + align:start position:0% +If you have an Android phone, you're + + + align:start position:0% +If you have an Android phone, you're +probably running his code on it. Um and + + align:start position:0% +probably running his code on it. Um and + + + align:start position:0% +probably running his code on it. Um and +then he came back um and now he does + + align:start position:0% +then he came back um and now he does + + + align:start position:0% +then he came back um and now he does +policy stuff and he's sort of a + + align:start position:0% +policy stuff and he's sort of a + + + align:start position:0% +policy stuff and he's sort of a +philosopher again, but he's like AI what + + align:start position:0% +philosopher again, but he's like AI what + + + align:start position:0% +philosopher again, but he's like AI what +do you AI is what we call computing + + align:start position:0% +do you AI is what we call computing + + + align:start position:0% +do you AI is what we call computing +technologies that are new and we don't + + align:start position:0% +technologies that are new and we don't + + + align:start position:0% +technologies that are new and we don't +understand very well. Um, and 10 years + + align:start position:0% +understand very well. Um, and 10 years + + + align:start position:0% +understand very well. Um, and 10 years +from now, they won't be called AI + + align:start position:0% +from now, they won't be called AI + + + align:start position:0% +from now, they won't be called AI +anymore. Um, and so, uh, you know, like + + align:start position:0% +anymore. Um, and so, uh, you know, like + + + align:start position:0% +anymore. Um, and so, uh, you know, like +are generative pre-trained transformers + + align:start position:0% +are generative pre-trained transformers + + + align:start position:0% +are generative pre-trained transformers +peer communication? Well, you know, + + align:start position:0% +peer communication? Well, you know, + + + align:start position:0% +peer communication? Well, you know, +maybe, um, you know, if like what do I, + + align:start position:0% +maybe, um, you know, if like what do I, + + + align:start position:0% +maybe, um, you know, if like what do I, +what do I think? What do I think a + + align:start position:0% +what do I think? What do I think a + + + align:start position:0% +what do I think? What do I think a +peer-guided network is? Um, a learner + + align:start position:0% +peer-guided network is? Um, a learner + + + align:start position:0% +peer-guided network is? Um, a learner +enters a network with a wide range of + + align:start position:0% +enters a network with a wide range of + + + align:start position:0% +enters a network with a wide range of +learning resources that are generated by + + align:start position:0% +learning resources that are generated by + + + align:start position:0% +learning resources that are generated by +previously all human agents. Um, could + + align:start position:0% +previously all human agents. Um, could + + + align:start position:0% +previously all human agents. Um, could +an a, you know, could a generative + + align:start position:0% +an a, you know, could a generative + + + align:start position:0% +an a, you know, could a generative +pre-trained transformer generate a + + align:start position:0% +pre-trained transformer generate a + + + align:start position:0% +pre-trained transformer generate a +useful learning sequence? Seems + + align:start position:0% +useful learning sequence? Seems + + + align:start position:0% +useful learning sequence? Seems +plausible. Um, you know, I I I remain + + align:start position:0% +plausible. Um, you know, I I I remain + + + align:start position:0% +plausible. Um, you know, I I I remain +not entirely convinced. I I actually + + align:start position:0% +not entirely convinced. I I actually + + + align:start position:0% +not entirely convinced. I I actually +what somebody came up to me and was like + + align:start position:0% +what somebody came up to me and was like + + + align:start position:0% +what somebody came up to me and was like +like we're like we have a startup where + + align:start position:0% +like we're like we have a startup where + + + align:start position:0% +like we're like we have a startup where +we're creating online classes by having + + align:start position:0% +we're creating online classes by having + + + align:start position:0% +we're creating online classes by having +AI create the classes. And I was like, + + align:start position:0% +AI create the classes. And I was like, + + + align:start position:0% +AI create the classes. And I was like, +that just sounds like a terrible idea. + + align:start position:0% +that just sounds like a terrible idea. + + + align:start position:0% +that just sounds like a terrible idea. +In part because there's just such a huge + + align:start position:0% +In part because there's just such a huge + + + align:start position:0% +In part because there's just such a huge +surfet of classes. Like there's so many + + align:start position:0% +surfet of classes. Like there's so many + + + align:start position:0% +surfet of classes. Like there's so many +things out there and they're really not + + align:start position:0% +things out there and they're really not + + + align:start position:0% +things out there and they're really not +unfortunately that expensive to develop. + + align:start position:0% +unfortunately that expensive to develop. + + + align:start position:0% +unfortunately that expensive to develop. +Um like why do you mean machines to do + + align:start position:0% +Um like why do you mean machines to do + + + align:start position:0% +Um like why do you mean machines to do +them? Um + + align:start position:0% +them? Um + + + align:start position:0% +them? Um +uh I have a I have a colleague uh + + align:start position:0% +uh I have a I have a colleague uh + + + align:start position:0% +uh I have a I have a colleague uh +um Carolyn Ros who worked with chat bots + + align:start position:0% +um Carolyn Ros who worked with chat bots + + + align:start position:0% +um Carolyn Ros who worked with chat bots +for decades. Um + + align:start position:0% +for decades. Um + + + align:start position:0% +for decades. Um +uh and and she actually she's has + + align:start position:0% +uh and and she actually she's has + + + align:start position:0% +uh and and she actually she's has +convinced me to be very skeptical of + + align:start position:0% +convinced me to be very skeptical of + + + align:start position:0% +convinced me to be very skeptical of +interactions of individuals with chat + + align:start position:0% +interactions of individuals with chat + + + align:start position:0% +interactions of individuals with chat +bots. Um like I don't know how many of + + align:start position:0% +bots. Um like I don't know how many of + + + align:start position:0% +bots. Um like I don't know how many of +you in the last week spent more than an + + align:start position:0% +you in the last week spent more than an + + + align:start position:0% +you in the last week spent more than an +hour talking to a + + align:start position:0% +hour talking to a + + + align:start position:0% +hour talking to a +chatbot. Zero, maybe one. Um I just + + align:start position:0% +chatbot. Zero, maybe one. Um I just + + + align:start position:0% +chatbot. Zero, maybe one. Um I just +don't think people like it that much. Um + + align:start position:0% +don't think people like it that much. Um + + + align:start position:0% +don't think people like it that much. Um +she really thought that where they could + + align:start position:0% +she really thought that where they could + + + align:start position:0% +she really thought that where they could +be powerful is jumping in in the + + align:start position:0% +be powerful is jumping in in the + + + align:start position:0% +be powerful is jumping in in the +conversations between two people. Um + + align:start position:0% +conversations between two people. Um + + + align:start position:0% +conversations between two people. Um +that you just have peers talking to each + + align:start position:0% +that you just have peers talking to each + + + align:start position:0% +that you just have peers talking to each +other. So you're on this discussion + + align:start position:0% +other. So you're on this discussion + + + align:start position:0% +other. So you're on this discussion +forum and you're going back and forth or + + align:start position:0% +forum and you're going back and forth or + + + align:start position:0% +forum and you're going back and forth or +other things like that and then a bot + + align:start position:0% +other things like that and then a bot + + + align:start position:0% +other things like that and then a bot +comes in and sort of helps you um ask an + + align:start position:0% +comes in and sort of helps you um ask an + + + align:start position:0% +comes in and sort of helps you um ask an +interesting question. Get like oh look + + align:start position:0% +interesting question. Get like oh look + + + align:start position:0% +interesting question. Get like oh look +somebody over here has a different + + align:start position:0% +somebody over here has a different + + + align:start position:0% +somebody over here has a different +perspective on that. Let me connect you + + align:start position:0% +perspective on that. Let me connect you + + + align:start position:0% +perspective on that. Let me connect you +to that. and so you can talk and things + + align:start position:0% +to that. and so you can talk and things + + + align:start position:0% +to that. and so you can talk and things +like that. Um, but yeah, it totally I I + + align:start position:0% +like that. Um, but yeah, it totally I I + + + align:start position:0% +like that. Um, but yeah, it totally I I +think I think it totally seems plausible + + align:start position:0% +think I think it totally seems plausible + + + align:start position:0% +think I think it totally seems plausible +that a peer guided learning environment + + align:start position:0% +that a peer guided learning environment + + + align:start position:0% +that a peer guided learning environment +could include, you know, artificial + + align:start position:0% +could include, you know, artificial + + + align:start position:0% +could include, you know, artificial +agents that are doing things that humans + + align:start position:0% +agents that are doing things that humans + + + align:start position:0% +agents that are doing things that humans +had previously been doing. + + align:start position:0% +had previously been doing. + + + align:start position:0% +had previously been doing. +Yeah, I guess to like both your points + + align:start position:0% +Yeah, I guess to like both your points + + + align:start position:0% +Yeah, I guess to like both your points +of like a interaction, I I would say um + + align:start position:0% +of like a interaction, I I would say um + + + align:start position:0% +of like a interaction, I I would say um +um an interesting aspect of that + + align:start position:0% +um an interesting aspect of that + + + align:start position:0% +um an interesting aspect of that +especially in terms of like what can be + + align:start position:0% +especially in terms of like what can be + + + align:start position:0% +especially in terms of like what can be +a credible source for learning and stuff + + align:start position:0% +a credible source for learning and stuff + + + align:start position:0% +a credible source for learning and stuff +like that. So, I think in California, or + + align:start position:0% +like that. So, I think in California, or + + + align:start position:0% +like that. So, I think in California, or +at least the the the part of California + + align:start position:0% +at least the the the part of California + + + align:start position:0% +at least the the the part of California +I was in for a while, we did have like a + + align:start position:0% +I was in for a while, we did have like a + + + align:start position:0% +I was in for a while, we did have like a +middle school little like a week-l long + + align:start position:0% +middle school little like a week-l long + + + align:start position:0% +middle school little like a week-l long +program that every kid had to do that + + align:start position:0% +program that every kid had to do that + + + align:start position:0% +program that every kid had to do that +was like, "Oh, you're 13. Here, make an + + align:start position:0% +was like, "Oh, you're 13. Here, make an + + + align:start position:0% +was like, "Oh, you're 13. Here, make an +email and here's how you Google stuff." + + align:start position:0% +email and here's how you Google stuff." + + + align:start position:0% +email and here's how you Google stuff." +Um, and like recently with um the new + + align:start position:0% +Um, and like recently with um the new + + + align:start position:0% +Um, and like recently with um the new +Google AI feature that kind of + + align:start position:0% +Google AI feature that kind of + + + align:start position:0% +Google AI feature that kind of +summarizes answers for you. Now, I was + + align:start position:0% +summarizes answers for you. Now, I was + + + align:start position:0% +summarizes answers for you. Now, I was +like thinking about like um how does + + align:start position:0% +like thinking about like um how does + + + align:start position:0% +like thinking about like um how does +that + + align:start position:0% +that + + + align:start position:0% +that +change kind of those levels of + + align:start position:0% +change kind of those levels of + + + align:start position:0% +change kind of those levels of +instructions? Because sometimes I look + + align:start position:0% +instructions? Because sometimes I look + + + align:start position:0% +instructions? Because sometimes I look +up things and I see the summary and I'm + + align:start position:0% +up things and I see the summary and I'm + + + align:start position:0% +up things and I see the summary and I'm +like I don't know what the answer is but + + align:start position:0% +like I don't know what the answer is but + + + align:start position:0% +like I don't know what the answer is but +I know it's not + + align:start position:0% +I know it's not + + + align:start position:0% +I know it's not +that and I and I go deeper. But like + + align:start position:0% +that and I and I go deeper. But like + + + align:start position:0% +that and I and I go deeper. But like +let's say if I'm a middle schooler and + + align:start position:0% +let's say if I'm a middle schooler and + + + align:start position:0% +let's say if I'm a middle schooler and +it's like well I don't learn this or I'm + + align:start position:0% +it's like well I don't learn this or I'm + + + align:start position:0% +it's like well I don't learn this or I'm +a high schooler that took that class in + + align:start position:0% +a high schooler that took that class in + + + align:start position:0% +a high schooler that took that class in +middle school and it's like well now I'm + + align:start position:0% +middle school and it's like well now I'm + + + align:start position:0% +middle school and it's like well now I'm +not sure or I take Bard's word for good. + + align:start position:0% +not sure or I take Bard's word for good. + + + align:start position:0% +not sure or I take Bard's word for good. +Yeah. Yeah. No, a hu a huge problem with + + align:start position:0% +Yeah. Yeah. No, a hu a huge problem with + + + align:start position:0% +Yeah. Yeah. No, a hu a huge problem with +GPT generated text is that it's probably + + align:start position:0% +GPT generated text is that it's probably + + + align:start position:0% +GPT generated text is that it's probably +much more useful for experts than for + + align:start position:0% +much more useful for experts than for + + + align:start position:0% +much more useful for experts than for +noviceses. Um, so if you're an if you + + align:start position:0% +noviceses. Um, so if you're an if you + + + align:start position:0% +noviceses. Um, so if you're an if you +know you ask a GPT to make eight things + + align:start position:0% +know you ask a GPT to make eight things + + + align:start position:0% +know you ask a GPT to make eight things +and and two of them are cool and six of + + align:start position:0% +and and two of them are cool and six of + + + align:start position:0% +and and two of them are cool and six of +them are nonsense or the opposite, an + + align:start position:0% +them are nonsense or the opposite, an + + + align:start position:0% +them are nonsense or the opposite, an +expert can tell the difference and be + + align:start position:0% +expert can tell the difference and be + + + align:start position:0% +expert can tell the difference and be +like, "Oh, that was an idea I didn't + + align:start position:0% +like, "Oh, that was an idea I didn't + + + align:start position:0% +like, "Oh, that was an idea I didn't +have before." But a novice can't. A + + align:start position:0% +have before." But a novice can't. A + + + align:start position:0% +have before." But a novice can't. A +novice just looks and be like, "Okay, + + align:start position:0% +novice just looks and be like, "Okay, + + + align:start position:0% +novice just looks and be like, "Okay, +these are eight ideas. They all seem + + align:start position:0% +these are eight ideas. They all seem + + + align:start position:0% +these are eight ideas. They all seem +plausible and they're confidently stated + + align:start position:0% +plausible and they're confidently stated + + + align:start position:0% +plausible and they're confidently stated +and things like that." It's a huge + + align:start position:0% +and things like that." It's a huge + + + align:start position:0% +and things like that." It's a huge +problem that educators are going to have + + align:start position:0% +problem that educators are going to have + + + align:start position:0% +problem that educators are going to have +to wrestle with um in the in the years + + align:start position:0% +to wrestle with um in the in the years + + + align:start position:0% +to wrestle with um in the in the years +ahead. + + align:start position:0% +ahead. + + + align:start position:0% +ahead. +Um it's, you know, the kind of class + + align:start position:0% +Um it's, you know, the kind of class + + + align:start position:0% +Um it's, you know, the kind of class +that you're describing, um if if it were + + align:start position:0% +that you're describing, um if if it were + + + align:start position:0% +that you're describing, um if if it were +to be taught 10 years ago, a big thing + + align:start position:0% +to be taught 10 years ago, a big thing + + + align:start position:0% +to be taught 10 years ago, a big thing +that educators were thinking about at + + align:start position:0% +that educators were thinking about at + + + align:start position:0% +that educators were thinking about at +the time was how are people going to + + align:start position:0% +the time was how are people going to + + + align:start position:0% +the time was how are people going to +navigate a social web? Um so, um when + + align:start position:0% +navigate a social web? Um so, um when + + + align:start position:0% +navigate a social web? Um so, um when +when the web was first developed, we'll + + align:start position:0% +when the web was first developed, we'll + + + align:start position:0% +when the web was first developed, we'll +get into this a little bit more, it was + + align:start position:0% +get into this a little bit more, it was + + + align:start position:0% +get into this a little bit more, it was +pretty hard for people to contribute to + + align:start position:0% +pretty hard for people to contribute to + + + align:start position:0% +pretty hard for people to contribute to +it. Um you had to know a little bit + + align:start position:0% +it. Um you had to know a little bit + + + align:start position:0% +it. Um you had to know a little bit +about FTP, you had to know a little bit + + align:start position:0% +about FTP, you had to know a little bit + + + align:start position:0% +about FTP, you had to know a little bit +about HTML, a couple other things like + + align:start position:0% +about HTML, a couple other things like + + + align:start position:0% +about HTML, a couple other things like +that. They weren't like super hard, but + + align:start position:0% +that. They weren't like super hard, but + + + align:start position:0% +that. They weren't like super hard, but +there was a relatively small portion of + + align:start position:0% +there was a relatively small portion of + + + align:start position:0% +there was a relatively small portion of +the population that added content to the + + align:start position:0% +the population that added content to the + + + align:start position:0% +the population that added content to the +internet. Um, and there were suite of + + align:start position:0% +internet. Um, and there were suite of + + + align:start position:0% +internet. Um, and there were suite of +technologies that got bundled and called + + align:start position:0% +technologies that got bundled and called + + + align:start position:0% +technologies that got bundled and called +web 2.0. Um, which said, okay, we're + + align:start position:0% +web 2.0. Um, which said, okay, we're + + + align:start position:0% +web 2.0. Um, which said, okay, we're +going to make it much easier for anybody + + align:start position:0% +going to make it much easier for anybody + + + align:start position:0% +going to make it much easier for anybody +to type things online. You can all start + + align:start position:0% +to type things online. You can all start + + + align:start position:0% +to type things online. You can all start +a blog. You can all start a micro blog. + + align:start position:0% +a blog. You can all start a micro blog. + + + align:start position:0% +a blog. You can all start a micro blog. +You can all make a simple website. You + + align:start position:0% +You can all make a simple website. You + + + align:start position:0% +You can all make a simple website. You +don't have to know how to code to do any + + align:start position:0% +don't have to know how to code to do any + + + align:start position:0% +don't have to know how to code to do any +of these things. Um, we're gonna we're + + align:start position:0% +of these things. Um, we're gonna we're + + + align:start position:0% +of these things. Um, we're gonna we're +going to use user interfaces to take + + align:start position:0% +going to use user interfaces to take + + + align:start position:0% +going to use user interfaces to take +away all that sort of programming + + align:start position:0% +away all that sort of programming + + + align:start position:0% +away all that sort of programming +expertise that's necessary. And so + + align:start position:0% +expertise that's necessary. And so + + + align:start position:0% +expertise that's necessary. And so +people thought, "Wow, you know, I bet + + align:start position:0% +people thought, "Wow, you know, I bet + + + align:start position:0% +people thought, "Wow, you know, I bet +our lives are going to and you know, + + align:start position:0% +our lives are going to and you know, + + + align:start position:0% +our lives are going to and you know, +young people's lives." If you, you know, + + align:start position:0% +young people's lives." If you, you know, + + + align:start position:0% +young people's lives." If you, you know, +if you were teaching 11 year olds, 12 + + align:start position:0% +if you were teaching 11 year olds, 12 + + + align:start position:0% +if you were teaching 11 year olds, 12 +year olds in 2013, you thought, man, a + + align:start position:0% +year olds in 2013, you thought, man, a + + + align:start position:0% +year olds in 2013, you thought, man, a +major thing they're going to have to do + + align:start position:0% +major thing they're going to have to do + + + align:start position:0% +major thing they're going to have to do +is how to connect and network with each + + align:start position:0% +is how to connect and network with each + + + align:start position:0% +is how to connect and network with each +other. We have to have them create their + + align:start position:0% +other. We have to have them create their + + + align:start position:0% +other. We have to have them create their +LinkedIn page um so that they know how + + align:start position:0% +LinkedIn page um so that they know how + + + align:start position:0% +LinkedIn page um so that they know how +to social network with each other. We + + align:start position:0% +to social network with each other. We + + + align:start position:0% +to social network with each other. We +have to have them um, you know, + + align:start position:0% +have to have them um, you know, + + + align:start position:0% +have to have them um, you know, +participate in online dialogues. We have + + align:start position:0% +participate in online dialogues. We have + + + align:start position:0% +participate in online dialogues. We have +to have them think about what are + + align:start position:0% +to have them think about what are + + + align:start position:0% +to have them think about what are +responsible ways of representing + + align:start position:0% +responsible ways of representing + + + align:start position:0% +responsible ways of representing +themselves. Um people talk a lot about + + align:start position:0% +themselves. Um people talk a lot about + + + align:start position:0% +themselves. Um people talk a lot about +their digital footprint um and other + + align:start position:0% +their digital footprint um and other + + + align:start position:0% +their digital footprint um and other +kinds of things like that. Um you know + + align:start position:0% +kinds of things like that. Um you know + + + align:start position:0% +kinds of things like that. Um you know +today a 13-year-old is entering a web + + align:start position:0% +today a 13-year-old is entering a web + + + align:start position:0% +today a 13-year-old is entering a web +environment in which there are lots of + + align:start position:0% +environment in which there are lots of + + + align:start position:0% +environment in which there are lots of +parts of social media which are + + align:start position:0% +parts of social media which are + + + align:start position:0% +parts of social media which are +collapsing. Um that uh um you know just + + align:start position:0% +collapsing. Um that uh um you know just + + + align:start position:0% +collapsing. Um that uh um you know just +as an example actually I was I went to + + align:start position:0% +as an example actually I was I went to + + + align:start position:0% +as an example actually I was I went to +the guy who ran this conference on + + align:start position:0% +the guy who ran this conference on + + + align:start position:0% +the guy who ran this conference on +Monday and well it was kind of so there + + align:start position:0% +Monday and well it was kind of so there + + + align:start position:0% +Monday and well it was kind of so there +were usually this conference get 100 or + + align:start position:0% +were usually this conference get 100 or + + + align:start position:0% +were usually this conference get 100 or +150 people show up. It was about AI. + + align:start position:0% +150 people show up. It was about AI. + + + align:start position:0% +150 people show up. It was about AI. +They had 240 people show up and 70 folks + + align:start position:0% +They had 240 people show up and 70 folks + + + align:start position:0% +They had 240 people show up and 70 folks +were on the wait list. Um, tons and tons + + align:start position:0% +were on the wait list. Um, tons and tons + + + align:start position:0% +were on the wait list. Um, tons and tons +of interest from educators. And I and I + + align:start position:0% +of interest from educators. And I and I + + + align:start position:0% +of interest from educators. And I and I +went to the guy who runs it, Tom + + align:start position:0% +went to the guy who runs it, Tom + + + align:start position:0% +went to the guy who runs it, Tom +Driscoll, and says, "What do you think + + align:start position:0% +Driscoll, and says, "What do you think + + + align:start position:0% +Driscoll, and says, "What do you think +these teachers are interested in? Like + + align:start position:0% +these teachers are interested in? Like + + + align:start position:0% +these teachers are interested in? Like +what are you like, what do they want to + + align:start position:0% +what are you like, what do they want to + + + align:start position:0% +what are you like, what do they want to +know? Why are they here?" Um, and he's + + align:start position:0% +know? Why are they here?" Um, and he's + + + align:start position:0% +know? Why are they here?" Um, and he's +like, "You know what? I don't know." Um, + + align:start position:0% +like, "You know what? I don't know." Um, + + + align:start position:0% +like, "You know what? I don't know." Um, +10 years ago, they would have had blogs. + + align:start position:0% +10 years ago, they would have had blogs. + + + align:start position:0% +10 years ago, they would have had blogs. +They would have, you know, participated + + align:start position:0% +They would have, you know, participated + + + align:start position:0% +They would have, you know, participated +in forums. They would have joined + + align:start position:0% +in forums. They would have joined + + + align:start position:0% +in forums. They would have joined +Facebook groups. they would have sort of + + align:start position:0% +Facebook groups. they would have sort of + + + align:start position:0% +Facebook groups. they would have sort of +like um uh they had there were many many + + align:start position:0% +like um uh they had there were many many + + + align:start position:0% +like um uh they had there were many many +more ways that educators were + + align:start position:0% +more ways that educators were + + + align:start position:0% +more ways that educators were +proactively um contributing their ideas + + align:start position:0% +proactively um contributing their ideas + + + align:start position:0% +proactively um contributing their ideas +to the web. Maybe not all of them. Maybe + + align:start position:0% +to the web. Maybe not all of them. Maybe + + + align:start position:0% +to the web. Maybe not all of them. Maybe +it was you know 10% of them or 20% of + + align:start position:0% +it was you know 10% of them or 20% of + + + align:start position:0% +it was you know 10% of them or 20% of +the time but enough of them that you + + align:start position:0% +the time but enough of them that you + + + align:start position:0% +the time but enough of them that you +could kind of get the pulse of a whole + + align:start position:0% +could kind of get the pulse of a whole + + + align:start position:0% +could kind of get the pulse of a whole +community. Um which he felt like and I + + align:start position:0% +community. Um which he felt like and I + + + align:start position:0% +community. Um which he felt like and I +agree you really can't do anymore. Um + + align:start position:0% +agree you really can't do anymore. Um + + + align:start position:0% +agree you really can't do anymore. Um +some of that is that there was there was + + align:start position:0% +some of that is that there was there was + + + align:start position:0% +some of that is that there was there was +a moment in web 2.0 know in which people + + align:start position:0% +a moment in web 2.0 know in which people + + + align:start position:0% +a moment in web 2.0 know in which people +believed that the infrastructure of the + + align:start position:0% +believed that the infrastructure of the + + + align:start position:0% +believed that the infrastructure of the +web might be really quite open and quite + + align:start position:0% +web might be really quite open and quite + + + align:start position:0% +web might be really quite open and quite +owned um or controlled by individual + + align:start position:0% +owned um or controlled by individual + + + align:start position:0% +owned um or controlled by individual +people um that there could be a world + + align:start position:0% +people um that there could be a world + + + align:start position:0% +people um that there could be a world +where people create their own websites, + + align:start position:0% +where people create their own websites, + + + align:start position:0% +where people create their own websites, +they create their own blogs, they host + + align:start position:0% +they create their own blogs, they host + + + align:start position:0% +they create their own blogs, they host +their own accounts and things like that. + + align:start position:0% +their own accounts and things like that. + + + align:start position:0% +their own accounts and things like that. +Um and uh you know I don't know when + + align:start position:0% +Um and uh you know I don't know when + + + align:start position:0% +Um and uh you know I don't know when +some of these things starting around + + align:start position:0% +some of these things starting around + + + align:start position:0% +some of these things starting around +2015 2016 people started describing um + + align:start position:0% +2015 2016 people started describing um + + + align:start position:0% +2015 2016 people started describing um +the web we lost a kind of a kind of + + align:start position:0% +the web we lost a kind of a kind of + + + align:start position:0% +the web we lost a kind of a kind of +moment in which social media took a turn + + align:start position:0% +moment in which social media took a turn + + + align:start position:0% +moment in which social media took a turn +um uh you know so these are the kinds of + + align:start position:0% +um uh you know so these are the kinds of + + + align:start position:0% +um uh you know so these are the kinds of +things that like I don't know I was + + align:start position:0% +things that like I don't know I was + + + align:start position:0% +things that like I don't know I was +playing around with in 2004 2007 any of + + align:start position:0% +playing around with in 2004 2007 any of + + + align:start position:0% +playing around with in 2004 2007 any of +you have a live journal blog as one of + + align:start position:0% +you have a live journal blog as one of + + + align:start position:0% +you have a live journal blog as one of +the early sort of blogging sites people + + align:start position:0% +the early sort of blogging sites people + + + align:start position:0% +the early sort of blogging sites people +like create their own space and hosting + + align:start position:0% +like create their own space and hosting + + + align:start position:0% +like create their own space and hosting +it this was a wordpress.com blog of my + + align:start position:0% +it this was a wordpress.com blog of my + + + align:start position:0% +it this was a wordpress.com blog of my +wife and I you know, writing little + + align:start position:0% +wife and I you know, writing little + + + align:start position:0% +wife and I you know, writing little +stories about us, going on adventures + + align:start position:0% +stories about us, going on adventures + + + align:start position:0% +stories about us, going on adventures +and things like that. Um, posting + + align:start position:0% +and things like that. Um, posting + + + align:start position:0% +and things like that. Um, posting +pictures, hosting it ourselves. Um, and + + align:start position:0% +pictures, hosting it ourselves. Um, and + + + align:start position:0% +pictures, hosting it ourselves. Um, and +essentially Facebook came and sort of + + align:start position:0% +essentially Facebook came and sort of + + + align:start position:0% +essentially Facebook came and sort of +demolished all this. Um, and said, you + + align:start position:0% +demolished all this. Um, and said, you + + + align:start position:0% +demolished all this. Um, and said, you +know what, like you don't need to host + + align:start position:0% +know what, like you don't need to host + + + align:start position:0% +know what, like you don't need to host +your own blog. You don't need to um, you + + align:start position:0% +your own blog. You don't need to um, you + + + align:start position:0% +your own blog. You don't need to um, you +know, you don't need to like figure out + + align:start position:0% +know, you don't need to like figure out + + + align:start position:0% +know, you don't need to like figure out +an FTP server to upload your own + + align:start position:0% +an FTP server to upload your own + + + align:start position:0% +an FTP server to upload your own +pictures or use a picture interface. + + align:start position:0% +pictures or use a picture interface. + + + align:start position:0% +pictures or use a picture interface. +Like we're going to create an interface + + align:start position:0% +Like we're going to create an interface + + + align:start position:0% +Like we're going to create an interface +there. people participate in a lot of + + align:start position:0% +there. people participate in a lot of + + + align:start position:0% +there. people participate in a lot of +the same kind of practices on Facebook + + align:start position:0% +the same kind of practices on Facebook + + + align:start position:0% +the same kind of practices on Facebook +of writing little stories on the trips + + align:start position:0% +of writing little stories on the trips + + + align:start position:0% +of writing little stories on the trips +they do and posting pictures and stuff + + align:start position:0% +they do and posting pictures and stuff + + + align:start position:0% +they do and posting pictures and stuff +like that. But all of a sudden it was + + align:start position:0% +like that. But all of a sudden it was + + + align:start position:0% +like that. But all of a sudden it was +all controlled by Mark Zuckerberg. Um + + align:start position:0% +all controlled by Mark Zuckerberg. Um + + + align:start position:0% +all controlled by Mark Zuckerberg. Um +this was a quote from David Weinberger. + + align:start position:0% +this was a quote from David Weinberger. + + + align:start position:0% +this was a quote from David Weinberger. +In many ways Facebook fulfilled the + + align:start position:0% +In many ways Facebook fulfilled the + + + align:start position:0% +In many ways Facebook fulfilled the +dream of blogging but like not exactly + + align:start position:0% +dream of blogging but like not exactly + + + align:start position:0% +dream of blogging but like not exactly +like like everybody was online but they + + align:start position:0% +like like everybody was online but they + + + align:start position:0% +like like everybody was online but they +weren't in spaces that they owned, had + + align:start position:0% +weren't in spaces that they owned, had + + + align:start position:0% +weren't in spaces that they owned, had +control over, had some familiarity with. + + align:start position:0% +control over, had some familiarity with. + + + align:start position:0% +control over, had some familiarity with. +Um and then um we'll talk about some of + + align:start position:0% +Um and then um we'll talk about some of + + + align:start position:0% +Um and then um we'll talk about some of +this as it goes along. Um, I think there + + align:start position:0% +this as it goes along. Um, I think there + + + align:start position:0% +this as it goes along. Um, I think there +was a there was a moment in which + + align:start position:0% +was a there was a moment in which + + + align:start position:0% +was a there was a moment in which +participation in a broad online life + + align:start position:0% +participation in a broad online life + + + align:start position:0% +participation in a broad online life +felt much less toxic and draining and + + align:start position:0% +felt much less toxic and draining and + + + align:start position:0% +felt much less toxic and draining and +vulnerability inspiring as it does right + + align:start position:0% +vulnerability inspiring as it does right + + + align:start position:0% +vulnerability inspiring as it does right +now. Um uh you know I mean if if there + + align:start position:0% +now. Um uh you know I mean if if there + + + align:start position:0% +now. Um uh you know I mean if if there +are there if you're a teacher who's + + align:start position:0% +are there if you're a teacher who's + + + align:start position:0% +are there if you're a teacher who's +working in a state which has recently + + align:start position:0% +working in a state which has recently + + + align:start position:0% +working in a state which has recently +passed a divisive concepts law um or + + align:start position:0% +passed a divisive concepts law um or + + + align:start position:0% +passed a divisive concepts law um or +other things like that regulating the + + align:start position:0% +other things like that regulating the + + + align:start position:0% +other things like that regulating the +kinds of topics you can talk about and + + align:start position:0% +kinds of topics you can talk about and + + + align:start position:0% +kinds of topics you can talk about and +things like that like all of that has a + + align:start position:0% +things like that like all of that has a + + + align:start position:0% +things like that like all of that has a +sort of chilling effect um you know not + + align:start position:0% +sort of chilling effect um you know not + + + align:start position:0% +sort of chilling effect um you know not +I mean not to mention just the the ways + + align:start position:0% +I mean not to mention just the the ways + + + align:start position:0% +I mean not to mention just the the ways +in which you know the social media + + align:start position:0% +in which you know the social media + + + align:start position:0% +in which you know the social media +services Facebook Twitter other kinds of + + align:start position:0% +services Facebook Twitter other kinds of + + + align:start position:0% +services Facebook Twitter other kinds of +things we use have sort of degraded um + + align:start position:0% +things we use have sort of degraded um + + + align:start position:0% +things we use have sort of degraded um +in their conversations over time um uh + + align:start position:0% +in their conversations over time um uh + + + align:start position:0% +in their conversations over time um uh +you This is what David Weinberger said. + + align:start position:0% +you This is what David Weinberger said. + + + align:start position:0% +you This is what David Weinberger said. +The bloggers field did not scale. Um + + align:start position:0% +The bloggers field did not scale. Um + + + align:start position:0% +The bloggers field did not scale. Um +like like there you know some people + + align:start position:0% +like like there you know some people + + + align:start position:0% +like like there you know some people +created their own blogs but not + + align:start position:0% +created their own blogs but not + + + align:start position:0% +created their own blogs but not +everyone. Um and then Facebook came in + + align:start position:0% +everyone. Um and then Facebook came in + + + align:start position:0% +everyone. Um and then Facebook came in +and many people who created blogs like + + align:start position:0% +and many people who created blogs like + + + align:start position:0% +and many people who created blogs like +I'll just post to Facebook. A lot of + + align:start position:0% +I'll just post to Facebook. A lot of + + + align:start position:0% +I'll just post to Facebook. A lot of +those people have like moved over to + + align:start position:0% +those people have like moved over to + + + align:start position:0% +those people have like moved over to +Substack now or other kinds of things + + align:start position:0% +Substack now or other kinds of things + + + align:start position:0% +Substack now or other kinds of things +like that but but systems that they + + align:start position:0% +like that but but systems that they + + + align:start position:0% +like that but but systems that they +don't control. Um there is I think a + + align:start position:0% +don't control. Um there is I think a + + + align:start position:0% +don't control. Um there is I think a +parallel to that story that happened in + + align:start position:0% +parallel to that story that happened in + + + align:start position:0% +parallel to that story that happened in +higher education. Um so in the early + + align:start position:0% +higher education. Um so in the early + + + align:start position:0% +higher education. Um so in the early +days um when the web was first made + + align:start position:0% +days um when the web was first made + + + align:start position:0% +days um when the web was first made +available broadly to schools which also + + align:start position:0% +available broadly to schools which also + + + align:start position:0% +available broadly to schools which also +h you know happens to overlap with my + + align:start position:0% +h you know happens to overlap with my + + + align:start position:0% +h you know happens to overlap with my +life. So I I think in 1993 Dartmouth + + align:start position:0% +life. So I I think in 1993 Dartmouth + + + align:start position:0% +life. So I I think in 1993 Dartmouth +College is the first college to give um + + align:start position:0% +College is the first college to give um + + + align:start position:0% +College is the first college to give um +every incoming student an email address. + + align:start position:0% +every incoming student an email address. + + + align:start position:0% +every incoming student an email address. +I think in + + align:start position:0% +I think in + + + align:start position:0% +I think in +1994 very quickly many many other + + align:start position:0% +1994 very quickly many many other + + + align:start position:0% +1994 very quickly many many other +colleges had done that. By the time I + + align:start position:0% +colleges had done that. By the time I + + + align:start position:0% +colleges had done that. By the time I +graduated high school but certainly by + + align:start position:0% +graduated high school but certainly by + + + align:start position:0% +graduated high school but certainly by +the time I was into college in 1996 um I + + align:start position:0% +the time I was into college in 1996 um I + + + align:start position:0% +the time I was into college in 1996 um I +had an email address. everybody else + + align:start position:0% +had an email address. everybody else + + + align:start position:0% +had an email address. everybody else +would have had an email address. That + + align:start position:0% +would have had an email address. That + + + align:start position:0% +would have had an email address. That +would have been, you know, um pretty + + align:start position:0% +would have been, you know, um pretty + + + align:start position:0% +would have been, you know, um pretty +pretty universal and standard. Um but + + align:start position:0% +pretty universal and standard. Um but + + + align:start position:0% +pretty universal and standard. Um but +this is what university web pages looked + + align:start position:0% +this is what university web pages looked + + + align:start position:0% +this is what university web pages looked +like at the time. Um MIT still has some + + align:start position:0% +like at the time. Um MIT still has some + + + align:start position:0% +like at the time. Um MIT still has some +of these kinds of things. Has anybody + + align:start position:0% +of these kinds of things. Has anybody + + + align:start position:0% +of these kinds of things. Has anybody +ever been to somebody's tilda space? You + + align:start position:0% +ever been to somebody's tilda space? You + + + align:start position:0% +ever been to somebody's tilda space? You +know, + + align:start position:0% + + + + align:start position:0% + +www.mmit.eduilda jri or something like + + align:start position:0% +www.mmit.eduilda jri or something like + + + align:start position:0% +www.mmit.eduilda jri or something like +that. Who do you um Oh man, the 1806 + + align:start position:0% +that. Who do you um Oh man, the 1806 + + + align:start position:0% +that. Who do you um Oh man, the 1806 +professor. What's what's his + + align:start position:0% +professor. What's what's his + + + align:start position:0% +professor. What's what's his +forgetting? Um the one who just retired + + align:start position:0% +forgetting? Um the one who just retired + + + align:start position:0% +forgetting? Um the one who just retired +Gil String. Good. Perfect. Great. Others + + align:start position:0% +Gil String. Good. Perfect. Great. Others + + + align:start position:0% +Gil String. Good. Perfect. Great. Others +that people can think of who have these + + align:start position:0% +that people can think of who have these + + + align:start position:0% +that people can think of who have these +things? So, um um so some things that + + align:start position:0% +things? So, um um so some things that + + + align:start position:0% +things? So, um um so some things that +you'll notice about the Well, I don't + + align:start position:0% +you'll notice about the Well, I don't + + + align:start position:0% +you'll notice about the Well, I don't +know. What do you just looking at these + + align:start position:0% +know. What do you just looking at these + + + align:start position:0% +know. What do you just looking at these +pictures? What do you notice about these + + align:start position:0% +pictures? What do you notice about these + + + align:start position:0% +pictures? What do you notice about these +things? What strikes you about them? + + align:start position:0% +things? What strikes you about them? + + + align:start position:0% +things? What strikes you about them? +There were some giggles before, which I + + align:start position:0% +There were some giggles before, which I + + + align:start position:0% +There were some giggles before, which I +think is appropriate. + + align:start position:0% + + + + align:start position:0% + +Like everything is + + align:start position:0% +Like everything is + + + align:start position:0% +Like everything is +okay. So, you know, not a lot of font + + align:start position:0% +okay. So, you know, not a lot of font + + + align:start position:0% +okay. So, you know, not a lot of font +diversity. What else? + + align:start position:0% + + + + align:start position:0% + +There's no advertisements. Yeah. Good. + + align:start position:0% +There's no advertisements. Yeah. Good. + + + align:start position:0% +There's no advertisements. Yeah. Good. +No, these are so so these were not + + align:start position:0% +No, these are so so these were not + + + align:start position:0% +No, these are so so these were not +created like with Wix or something like + + align:start position:0% +created like with Wix or something like + + + align:start position:0% +created like with Wix or something like +that where in exchange for making a + + align:start position:0% +that where in exchange for making a + + + align:start position:0% +that where in exchange for making a +website you have to put a bar of + + align:start position:0% +website you have to put a bar of + + + align:start position:0% +website you have to put a bar of +advertisements at the bottom or + + align:start position:0% +advertisements at the bottom or + + + align:start position:0% +advertisements at the bottom or +something like that. So somebody + + align:start position:0% +something like that. So somebody + + + align:start position:0% +something like that. So somebody +actually made these pages. They're all + + align:start position:0% +actually made these pages. They're all + + + align:start position:0% +actually made these pages. They're all +personal homepages. Other things that + + align:start position:0% +personal homepages. Other things that + + + align:start position:0% +personal homepages. Other things that +strike you? + + align:start position:0% +strike you? + + + align:start position:0% +strike you? +The backgrounds. What about the + + align:start position:0% +The backgrounds. What about the + + + align:start position:0% +The backgrounds. What about the +backgrounds? + + align:start position:0% +backgrounds? + + + align:start position:0% +backgrounds? +Um it's certainly of like I don't know. + + align:start position:0% +Um it's certainly of like I don't know. + + + align:start position:0% +Um it's certainly of like I don't know. +I I feel like I I personally associate + + align:start position:0% +I I feel like I I personally associate + + + align:start position:0% +I I feel like I I personally associate +them with a very specific time period. + + align:start position:0% +them with a very specific time period. + + + align:start position:0% +them with a very specific time period. +Okay, good. It's like this is natural. + + align:start position:0% +Okay, good. It's like this is natural. + + + align:start position:0% +Okay, good. It's like this is natural. +They they have they have a '9s aesthetic + + align:start position:0% +They they have they have a '9s aesthetic + + + align:start position:0% +They they have they have a '9s aesthetic +to them. Yeah. I would say maybe it is + + align:start position:0% +to them. Yeah. I would say maybe it is + + + align:start position:0% +to them. Yeah. I would say maybe it is +like partially just like the quality of + + align:start position:0% +like partially just like the quality of + + + align:start position:0% +like partially just like the quality of +like like let's say a pattern or + + align:start position:0% +like like let's say a pattern or + + + align:start position:0% +like like let's say a pattern or +something you can put on or like now we + + align:start position:0% +something you can put on or like now we + + + align:start position:0% +something you can put on or like now we +have a lot of templates that make sure + + align:start position:0% +have a lot of templates that make sure + + + align:start position:0% +have a lot of templates that make sure +it's like aesthetically consistent. This + + align:start position:0% +it's like aesthetically consistent. This + + + align:start position:0% +it's like aesthetically consistent. This +is pre-CAva. We're not we're not uh Ken, + + align:start position:0% +is pre-CAva. We're not we're not uh Ken, + + + align:start position:0% +is pre-CAva. We're not we're not uh Ken, +what were you going to observe? Oh, I + + align:start position:0% +what were you going to observe? Oh, I + + + align:start position:0% +what were you going to observe? Oh, I +was about to say about the templates + + align:start position:0% +was about to say about the templates + + + align:start position:0% +was about to say about the templates +like they're not all using the exact + + align:start position:0% +like they're not all using the exact + + + align:start position:0% +like they're not all using the exact +same uh template and similar formatting. + + align:start position:0% +same uh template and similar formatting. + + + align:start position:0% +same uh template and similar formatting. +They're not all using the exact same + + align:start position:0% +They're not all using the exact same + + + align:start position:0% +They're not all using the exact same +template in similar formatting. I think + + align:start position:0% +template in similar formatting. I think + + + align:start position:0% +template in similar formatting. I think +that that is actually quite important. + + align:start position:0% +that that is actually quite important. + + + align:start position:0% +that that is actually quite important. +Um there are some good things that + + align:start position:0% +Um there are some good things that + + + align:start position:0% +Um there are some good things that +templates do of make things looking um + + align:start position:0% +templates do of make things looking um + + + align:start position:0% +templates do of make things looking um +uh aesthetic. Um but they standardize in + + align:start position:0% +uh aesthetic. Um but they standardize in + + + align:start position:0% +uh aesthetic. Um but they standardize in +a way. They they put things in the same + + align:start position:0% +a way. They they put things in the same + + + align:start position:0% +a way. They they put things in the same +way. People at universities do really + + align:start position:0% +way. People at universities do really + + + align:start position:0% +way. People at universities do really +really different kinds of things. That + + align:start position:0% +really different kinds of things. That + + + align:start position:0% +really different kinds of things. That +might be important. Other observations + + align:start position:0% +might be important. Other observations + + + align:start position:0% +might be important. Other observations +about these? It's very speromorphic. Um, + + align:start position:0% +about these? It's very speromorphic. Um, + + + align:start position:0% +about these? It's very speromorphic. Um, +like there's buttons on the the bottom + + align:start position:0% +like there's buttons on the the bottom + + + align:start position:0% +like there's buttons on the the bottom +left one with like icons that you don't + + align:start position:0% +left one with like icons that you don't + + + align:start position:0% +left one with like icons that you don't +see as often. And I want to say the + + align:start position:0% +see as often. And I want to say the + + + align:start position:0% +see as often. And I want to say the +background, especially the bottom left, + + align:start position:0% +background, especially the bottom left, + + + align:start position:0% +background, especially the bottom left, +reminds me of a a physical wallpaper. + + align:start position:0% +reminds me of a a physical wallpaper. + + + align:start position:0% +reminds me of a a physical wallpaper. +Uhhuh. Um, which is like a principle. Do + + align:start position:0% +Uhhuh. Um, which is like a principle. Do + + + align:start position:0% +Uhhuh. Um, which is like a principle. Do +you want to define skuorphism for us? + + align:start position:0% +you want to define skuorphism for us? + + + align:start position:0% +you want to define skuorphism for us? +Skeorphism is + + align:start position:0% +Skeorphism is + + + align:start position:0% +Skeorphism is +like the most famous example. It's + + align:start position:0% +like the most famous example. It's + + + align:start position:0% +like the most famous example. It's +probably like iOS 6 where you have all + + align:start position:0% +probably like iOS 6 where you have all + + + align:start position:0% +probably like iOS 6 where you have all +these buttons and like reflections that + + align:start position:0% +these buttons and like reflections that + + + align:start position:0% +these buttons and like reflections that +sort of try to mimic real life. And + + align:start position:0% +sort of try to mimic real life. And + + + align:start position:0% +sort of try to mimic real life. And +that's like what skuomorphism is trying + + align:start position:0% +that's like what skuomorphism is trying + + + align:start position:0% +that's like what skuomorphism is trying +to mimic real life. And then when we + + align:start position:0% +to mimic real life. And then when we + + + align:start position:0% +to mimic real life. And then when we +transition to iOS 7, you removed a lot + + align:start position:0% +transition to iOS 7, you removed a lot + + + align:start position:0% +transition to iOS 7, you removed a lot +of that dimension and it became a lot + + align:start position:0% +of that dimension and it became a lot + + + align:start position:0% +of that dimension and it became a lot +more simplistic and and symbolic. A lot + + align:start position:0% +more simplistic and and symbolic. A lot + + + align:start position:0% +more simplistic and and symbolic. A lot +of the early note-taking apps would have + + align:start position:0% +of the early note-taking apps would have + + + align:start position:0% +of the early note-taking apps would have +a background like a yellow legal pad or + + align:start position:0% +a background like a yellow legal pad or + + + align:start position:0% +a background like a yellow legal pad or +or like a spiral binding on the side or + + align:start position:0% +or like a spiral binding on the side or + + + align:start position:0% +or like a spiral binding on the side or +something like that and you're like, + + align:start position:0% +something like that and you're like, + + + align:start position:0% +something like that and you're like, +"Brother, we could put the we don't need + + align:start position:0% +"Brother, we could put the we don't need + + + align:start position:0% +"Brother, we could put the we don't need +the lines. Like the cursor will do that + + align:start position:0% +the lines. Like the cursor will do that + + + align:start position:0% +the lines. Like the cursor will do that +for you." Um but um people wanted to + + align:start position:0% +for you." Um but um people wanted to + + + align:start position:0% +for you." Um but um people wanted to +make some kind of connection between + + align:start position:0% +make some kind of connection between + + + align:start position:0% +make some kind of connection between +what they saw be you know what they saw + + align:start position:0% +what they saw be you know what they saw + + + align:start position:0% +what they saw be you know what they saw +in the physical world and what this new + + align:start position:0% +in the physical world and what this new + + + align:start position:0% +in the physical world and what this new +digital thing was trying to do. + + align:start position:0% +digital thing was trying to do. + + + align:start position:0% +digital thing was trying to do. +Skeumorphism shows up in that book + + align:start position:0% +Skeumorphism shows up in that book + + + align:start position:0% +Skeumorphism shows up in that book +somewhere. I can't remember now where I + + align:start position:0% +somewhere. I can't remember now where I + + + align:start position:0% +somewhere. I can't remember now where I +wrote about it but um um yeah I mean + + align:start position:0% +wrote about it but um um yeah I mean + + + align:start position:0% +wrote about it but um um yeah I mean +obviously these pictures are just + + align:start position:0% +obviously these pictures are just + + + align:start position:0% +obviously these pictures are just +outstanding. Um + + align:start position:0% +outstanding. Um + + + align:start position:0% +outstanding. Um +uh just like people had kind of like a + + align:start position:0% +uh just like people had kind of like a + + + align:start position:0% +uh just like people had kind of like a +cool + + align:start position:0% +cool + + + align:start position:0% +cool +idiosyncratic + + align:start position:0% +idiosyncratic + + + align:start position:0% +idiosyncratic +um personalized kind of a bane in the + + align:start position:0% +um personalized kind of a bane in the + + + align:start position:0% +um personalized kind of a bane in the +butt to organize sort of blogosphere + + align:start position:0% +butt to organize sort of blogosphere + + + align:start position:0% +butt to organize sort of blogosphere +that existed that Facebook just came and + + align:start position:0% +that existed that Facebook just came and + + + align:start position:0% +that existed that Facebook just came and +sort of demolished and homogenized and + + align:start position:0% +sort of demolished and homogenized and + + + align:start position:0% +sort of demolished and homogenized and +standardized and pulled out of the + + align:start position:0% +standardized and pulled out of the + + + align:start position:0% +standardized and pulled out of the +control of individual people's spaces + + align:start position:0% +control of individual people's spaces + + + align:start position:0% +control of individual people's spaces +and into this sort of corporate space. + + align:start position:0% +and into this sort of corporate space. + + + align:start position:0% +and into this sort of corporate space. +Um, you could say that Blackboard did + + align:start position:0% +Um, you could say that Blackboard did + + + align:start position:0% +Um, you could say that Blackboard did +something very very similar to campus + + align:start position:0% +something very very similar to campus + + + align:start position:0% +something very very similar to campus +web pages. Um, that learning management + + align:start position:0% +web pages. Um, that learning management + + + align:start position:0% +web pages. Um, that learning management +systems came along um and they said, + + align:start position:0% +systems came along um and they said, + + + align:start position:0% +systems came along um and they said, +"We're gonna standardize it all." Um, + + align:start position:0% +"We're gonna standardize it all." Um, + + + align:start position:0% +"We're gonna standardize it all." Um, +you you don't have you don't have to + + align:start position:0% +you you don't have you don't have to + + + align:start position:0% +you you don't have you don't have to +create your own page anymore. Like + + align:start position:0% +create your own page anymore. Like + + + align:start position:0% +create your own page anymore. Like +Blackboard will create your own faculty + + align:start position:0% +Blackboard will create your own faculty + + + align:start position:0% +Blackboard will create your own faculty +page, create your own course page. Um, + + align:start position:0% +page, create your own course page. Um, + + + align:start position:0% +page, create your own course page. Um, +and that's going to come with some kind + + align:start position:0% +and that's going to come with some kind + + + align:start position:0% +and that's going to come with some kind +of benefits of standardization. It's + + align:start position:0% +of benefits of standardization. It's + + + align:start position:0% +of benefits of standardization. It's +going to make it a lot easier for + + align:start position:0% +going to make it a lot easier for + + + align:start position:0% +going to make it a lot easier for +people, but it's but it's also going to + + align:start position:0% +people, but it's but it's also going to + + + align:start position:0% +people, but it's but it's also going to +get rid of um some of the kind of + + align:start position:0% +get rid of um some of the kind of + + + align:start position:0% +get rid of um some of the kind of +wonderful + + align:start position:0% +wonderful + + + align:start position:0% +wonderful +idiosyncrasies um of these things. And + + align:start position:0% +idiosyncrasies um of these things. And + + + align:start position:0% +idiosyncrasies um of these things. And +it's going to mean that there's a + + align:start position:0% +it's going to mean that there's a + + + align:start position:0% +it's going to mean that there's a +corporate entity who is who is not + + align:start position:0% +corporate entity who is who is not + + + align:start position:0% +corporate entity who is who is not +accountable who's accountable to their + + align:start position:0% +accountable who's accountable to their + + + align:start position:0% +accountable who's accountable to their +shareholders and not accountable to the + + align:start position:0% +shareholders and not accountable to the + + + align:start position:0% +shareholders and not accountable to the +same values that we might have as a + + align:start position:0% +same values that we might have as a + + + align:start position:0% +same values that we might have as a +university, which is deciding what those + + align:start position:0% +university, which is deciding what those + + + align:start position:0% +university, which is deciding what those +things look like. Much like when we move + + align:start position:0% +things look like. Much like when we move + + + align:start position:0% +things look like. Much like when we move +all of our blogs onto Facebook, um you + + align:start position:0% +all of our blogs onto Facebook, um you + + + align:start position:0% +all of our blogs onto Facebook, um you +don't even you're not even accountable + + align:start position:0% +don't even you're not even accountable + + + align:start position:0% +don't even you're not even accountable +to shareholders. are just accountable to + + align:start position:0% +to shareholders. are just accountable to + + + align:start position:0% +to shareholders. are just accountable to +whatever Mark thinks you know people + + align:start position:0% +whatever Mark thinks you know people + + + align:start position:0% +whatever Mark thinks you know people +should be doing in Facebook. Um yeah, in + + align:start position:0% +should be doing in Facebook. Um yeah, in + + + align:start position:0% +should be doing in Facebook. Um yeah, in +many ways Blackboard fulfilled the dream + + align:start position:0% +many ways Blackboard fulfilled the dream + + + align:start position:0% +many ways Blackboard fulfilled the dream +of the university till the spaces did + + align:start position:0% +of the university till the spaces did + + + align:start position:0% +of the university till the spaces did +not scale. I believe the problem could + + align:start position:0% +not scale. I believe the problem could + + + align:start position:0% +not scale. I believe the problem could +have been solved but then Blackboard + + align:start position:0% +have been solved but then Blackboard + + + align:start position:0% +have been solved but then Blackboard +happened. Um why would Blackboard + + align:start position:0% +happened. Um why would Blackboard + + + align:start position:0% +happened. Um why would Blackboard +happen? Um these are the instructions + + align:start position:0% +happen? Um these are the instructions + + + align:start position:0% +happen? Um these are the instructions +for Sunni onion about how you would go + + align:start position:0% +for Sunni onion about how you would go + + + align:start position:0% +for Sunni onion about how you would go +about creating one of your tilda space + + align:start position:0% +about creating one of your tilda space + + + align:start position:0% +about creating one of your tilda space +pages. you know, log into AAD, create a + + align:start position:0% +pages. you know, log into AAD, create a + + + align:start position:0% +pages. you know, log into AAD, create a +directory, change to this directory, + + align:start position:0% +directory, change to this directory, + + + align:start position:0% +directory, change to this directory, +create HTML documents, um, HTML + + align:start position:0% +create HTML documents, um, HTML + + + align:start position:0% +create HTML documents, um, HTML +developers jumpstation, you know, set + + align:start position:0% +developers jumpstation, you know, set + + + align:start position:0% +developers jumpstation, you know, set +pro equals w file namex. You can like + + align:start position:0% +pro equals w file namex. You can like + + + align:start position:0% +pro equals w file namex. You can like +you read about a page of this stuff and + + align:start position:0% +you read about a page of this stuff and + + + align:start position:0% +you read about a page of this stuff and +you're like, "Yeah, I can see why a lot + + align:start position:0% +you're like, "Yeah, I can see why a lot + + + align:start position:0% +you're like, "Yeah, I can see why a lot +of people, you know, like why launching + + align:start position:0% +of people, you know, like why launching + + + align:start position:0% +of people, you know, like why launching +a Blackboard page might be uh might be + + align:start position:0% +a Blackboard page might be uh might be + + + align:start position:0% +a Blackboard page might be uh might be +fine." Um, + + align:start position:0% +fine." Um, + + + align:start position:0% +fine." Um, +uh, uh, this is what the um, what is + + align:start position:0% +uh, uh, this is what the um, what is + + + align:start position:0% +uh, uh, this is what the um, what is +this + + align:start position:0% +this + + + align:start position:0% +this +blackboard? I don't I don't remember + + align:start position:0% +blackboard? I don't I don't remember + + + align:start position:0% +blackboard? I don't I don't remember +what uh learning management system this + + align:start position:0% +what uh learning management system this + + + align:start position:0% +what uh learning management system this +was. Maybe it's Canvas. It's not Canvas. + + align:start position:0% +was. Maybe it's Canvas. It's not Canvas. + + + align:start position:0% +was. Maybe it's Canvas. It's not Canvas. +I don't I can't remember what it is now. + + align:start position:0% +I don't I can't remember what it is now. + + + align:start position:0% +I don't I can't remember what it is now. +This is the this is the very first + + align:start position:0% +This is the this is the very first + + + align:start position:0% +This is the this is the very first +version of a sort of a version of this + + align:start position:0% +version of a sort of a version of this + + + align:start position:0% +version of a sort of a version of this +course um that I taught 10 years ago. Um + + align:start position:0% +course um that I taught 10 years ago. Um + + + align:start position:0% +course um that I taught 10 years ago. Um +and this is the this is the page that + + align:start position:0% +and this is the this is the page that + + + align:start position:0% +and this is the this is the page that +the that the system generated for me um + + align:start position:0% +the that the system generated for me um + + + align:start position:0% +the that the system generated for me um +when I first created the class. So it + + align:start position:0% +when I first created the class. So it + + + align:start position:0% +when I first created the class. So it +comes with a bunch of these sort of st + + align:start position:0% +comes with a bunch of these sort of st + + + align:start position:0% +comes with a bunch of these sort of st +not not this stuff that I added but + + align:start position:0% +not not this stuff that I added but + + + align:start position:0% +not not this stuff that I added but +syllabus class sessions other resources + + align:start position:0% +syllabus class sessions other resources + + + align:start position:0% +syllabus class sessions other resources +assignments collaborate information + + align:start position:0% +assignments collaborate information + + + align:start position:0% +assignments collaborate information +reserves list search this site lecture + + align:start position:0% +reserves list search this site lecture + + + align:start position:0% +reserves list search this site lecture +video um it makes a set of assumptions + + align:start position:0% +video um it makes a set of assumptions + + + align:start position:0% +video um it makes a set of assumptions +about what my course is um it says you + + align:start position:0% +about what my course is um it says you + + + align:start position:0% +about what my course is um it says you +know this is what the standard format of + + align:start position:0% +know this is what the standard format of + + + align:start position:0% +know this is what the standard format of +this learning experience should be um + + align:start position:0% +this learning experience should be um + + + align:start position:0% +this learning experience should be um +but maybe that's not at all what I want + + align:start position:0% +but maybe that's not at all what I want + + + align:start position:0% +but maybe that's not at all what I want +it certainly doesn't make a lot you know + + align:start position:0% +it certainly doesn't make a lot you know + + + align:start position:0% +it certainly doesn't make a lot you know +if I had if I had taught this class + + align:start position:0% +if I had if I had taught this class + + + align:start position:0% +if I had if I had taught this class +about this was in an education school if + + align:start position:0% +about this was in an education school if + + + align:start position:0% +about this was in an education school if +I had made this class about education + + align:start position:0% +I had made this class about education + + + align:start position:0% +I had made this class about education +technology ology about um the experience + + align:start position:0% +technology ology about um the experience + + + align:start position:0% +technology ology about um the experience +of indigenous kids learning on + + align:start position:0% +of indigenous kids learning on + + + align:start position:0% +of indigenous kids learning on +reservations about um I don't know the + + align:start position:0% +reservations about um I don't know the + + + align:start position:0% +reservations about um I don't know the +uh um global education policy um + + align:start position:0% +uh um global education policy um + + + align:start position:0% +uh um global education policy um +intermediate statistics it all would + + align:start position:0% +intermediate statistics it all would + + + align:start position:0% +intermediate statistics it all would +have been the exact same format um they + + align:start position:0% +have been the exact same format um they + + + align:start position:0% +have been the exact same format um they +would have given the same sort of + + align:start position:0% +would have given the same sort of + + + align:start position:0% +would have given the same sort of +standardized creation for this which + + align:start position:0% +standardized creation for this which + + + align:start position:0% +standardized creation for this which +just in lots of you know it makes sense + + align:start position:0% +just in lots of you know it makes sense + + + align:start position:0% +just in lots of you know it makes sense +in some kind of ways and it's bonkers in + + align:start position:0% +in some kind of ways and it's bonkers in + + + align:start position:0% +in some kind of ways and it's bonkers in +other kinds of ways our courses are + + align:start position:0% +other kinds of ways our courses are + + + align:start position:0% +other kinds of ways our courses are +super different why should all of our + + align:start position:0% +super different why should all of our + + + align:start position:0% +super different why should all of our +courses have the same template why + + align:start position:0% +courses have the same template why + + + align:start position:0% +courses have the same template why +should we all be sort of subtly + + align:start position:0% +should we all be sort of subtly + + + align:start position:0% +should we all be sort of subtly +invisibly squished into teaching our + + align:start position:0% +invisibly squished into teaching our + + + align:start position:0% +invisibly squished into teaching our +courses the same way um by by these + + align:start position:0% +courses the same way um by by these + + + align:start position:0% +courses the same way um by by these +kinds of structures. Um and of course + + align:start position:0% +kinds of structures. Um and of course + + + align:start position:0% +kinds of structures. Um and of course +there's all kinds of physical analoges + + align:start position:0% +there's all kinds of physical analoges + + + align:start position:0% +there's all kinds of physical analoges +to this too. Um the the way we design + + align:start position:0% +to this too. Um the the way we design + + + align:start position:0% +to this too. Um the the way we design +environments shapes the learning + + align:start position:0% +environments shapes the learning + + + align:start position:0% +environments shapes the learning +experiences um that happen in the I just + + align:start position:0% +experiences um that happen in the I just + + + align:start position:0% +experiences um that happen in the I just +read a beautiful sentence of this which + + align:start position:0% +read a beautiful sentence of this which + + + align:start position:0% +read a beautiful sentence of this which +is you know something like um it was + + align:start position:0% +is you know something like um it was + + + align:start position:0% +is you know something like um it was +something like buildings have agenda for + + align:start position:0% +something like buildings have agenda for + + + align:start position:0% +something like buildings have agenda for +their occupants. um the way that spaces + + align:start position:0% +their occupants. um the way that spaces + + + align:start position:0% +their occupants. um the way that spaces +are created, like it doesn't tell you + + align:start position:0% +are created, like it doesn't tell you + + + align:start position:0% +are created, like it doesn't tell you +what to do, but it certainly guides you. + + align:start position:0% +what to do, but it certainly guides you. + + + align:start position:0% +what to do, but it certainly guides you. +You know, you walk into a room like this + + align:start position:0% +You know, you walk into a room like this + + + align:start position:0% +You know, you walk into a room like this +um and you have some thoughts about the + + align:start position:0% +um and you have some thoughts about the + + + align:start position:0% +um and you have some thoughts about the +kind of learning that's going to happen + + align:start position:0% +kind of learning that's going to happen + + + align:start position:0% +kind of learning that's going to happen +in that space. Like, well, you're all + + align:start position:0% +in that space. Like, well, you're all + + + align:start position:0% +in that space. Like, well, you're all +going to be facing in the same + + align:start position:0% +going to be facing in the same + + + align:start position:0% +going to be facing in the same +direction. Probably not going to be + + align:start position:0% +direction. Probably not going to be + + + align:start position:0% +direction. Probably not going to be +talking to a whole each other a whole + + align:start position:0% +talking to a whole each other a whole + + + align:start position:0% +talking to a whole each other a whole +lot um in that space. There's some, you + + align:start position:0% +lot um in that space. There's some, you + + + align:start position:0% +lot um in that space. There's some, you +know, you're going to be writing with + + align:start position:0% +know, you're going to be writing with + + + align:start position:0% +know, you're going to be writing with +certain kinds of physical materials. If + + align:start position:0% +certain kinds of physical materials. If + + + align:start position:0% +certain kinds of physical materials. If +you try to use a laptop on those, uh, + + align:start position:0% +you try to use a laptop on those, uh, + + + align:start position:0% +you try to use a laptop on those, uh, +you know, square square tables, you'll + + align:start position:0% +you know, square square tables, you'll + + + align:start position:0% +you know, square square tables, you'll +have a hard time, you know, there's no + + align:start position:0% +have a hard time, you know, there's no + + + align:start position:0% +have a hard time, you know, there's no +room for power cords or other kinds of + + align:start position:0% +room for power cords or other kinds of + + + align:start position:0% +room for power cords or other kinds of +things like this. Um this is actually + + align:start position:0% +things like this. Um this is actually + + + align:start position:0% +things like this. Um this is actually +one of the most famous examples in elite + + align:start position:0% +one of the most famous examples in elite + + + align:start position:0% +one of the most famous examples in elite +private education in the United States. + + align:start position:0% +private education in the United States. + + + align:start position:0% +private education in the United States. +Um which is uh um there were um uh + + align:start position:0% +Um which is uh um there were um uh + + + align:start position:0% +Um which is uh um there were um uh +donors to the the Philips exit school + + align:start position:0% +donors to the the Philips exit school + + + align:start position:0% +donors to the the Philips exit school +who were really concerned um that that + + align:start position:0% +who were really concerned um that that + + + align:start position:0% +who were really concerned um that that +essentially there's too much + + align:start position:0% +essentially there's too much + + + align:start position:0% +essentially there's too much +instructionism and not enough + + align:start position:0% +instructionism and not enough + + + align:start position:0% +instructionism and not enough +constructionism. They wouldn't have said + + align:start position:0% +constructionism. They wouldn't have said + + + align:start position:0% +constructionism. They wouldn't have said +it the exact same way, but they would + + align:start position:0% +it the exact same way, but they would + + + align:start position:0% +it the exact same way, but they would +have said something along those lines. + + align:start position:0% +have said something along those lines. + + + align:start position:0% +have said something along those lines. +Too much sitting passive listening, not + + align:start position:0% +Too much sitting passive listening, not + + + align:start position:0% +Too much sitting passive listening, not +enough sort of engaged conversation. Um + + align:start position:0% +enough sort of engaged conversation. Um + + + align:start position:0% +enough sort of engaged conversation. Um +and so a a bunch of donors uh got + + align:start position:0% +and so a a bunch of donors uh got + + + align:start position:0% +and so a a bunch of donors uh got +together um and they said in every + + align:start position:0% +together um and they said in every + + + align:start position:0% +together um and they said in every +classroom we're going to pull out all of + + align:start position:0% +classroom we're going to pull out all of + + + align:start position:0% +classroom we're going to pull out all of +the chairs that look like this and we're + + align:start position:0% +the chairs that look like this and we're + + + align:start position:0% +the chairs that look like this and we're +going to put in these tables called + + align:start position:0% +going to put in these tables called + + + align:start position:0% +going to put in these tables called +Harkness tables. Um some of the features + + align:start position:0% +Harkness tables. Um some of the features + + + align:start position:0% +Harkness tables. Um some of the features +of Harkness tables are that you need to + + align:start position:0% +of Harkness tables are that you need to + + + align:start position:0% +of Harkness tables are that you need to +be able to fit everybody in the class + + align:start position:0% +be able to fit everybody in the class + + + align:start position:0% +be able to fit everybody in the class +sort of in an oval around the table. Um + + align:start position:0% +sort of in an oval around the table. Um + + + align:start position:0% +sort of in an oval around the table. Um +the tables are so large that they + + align:start position:0% +the tables are so large that they + + + align:start position:0% +the tables are so large that they +usually have to be like built in + + align:start position:0% +usually have to be like built in + + + align:start position:0% +usually have to be like built in +different pieces and then shipped into + + align:start position:0% +different pieces and then shipped into + + + align:start position:0% +different pieces and then shipped into +the room and then assembled inside the + + align:start position:0% +the room and then assembled inside the + + + align:start position:0% +the room and then assembled inside the +room. um they're incredibly heavy, but + + align:start position:0% +room. um they're incredibly heavy, but + + + align:start position:0% +room. um they're incredibly heavy, but +they um they they make it so there is no + + align:start position:0% +they um they they make it so there is no + + + align:start position:0% +they um they they make it so there is no +front of the room. Um they they and and + + align:start position:0% +front of the room. Um they they and and + + + align:start position:0% +front of the room. Um they they and and +they, you know, at Philips exit at other + + align:start position:0% +they, you know, at Philips exit at other + + + align:start position:0% +they, you know, at Philips exit at other +kinds of independent schools, they put + + align:start position:0% +kinds of independent schools, they put + + + align:start position:0% +kinds of independent schools, they put +these tables in every classroom. Um they + + align:start position:0% +these tables in every classroom. Um they + + + align:start position:0% +these tables in every classroom. Um they +put them in the English classrooms, they + + align:start position:0% +put them in the English classrooms, they + + + align:start position:0% +put them in the English classrooms, they +put them in the history classrooms, but + + align:start position:0% +put them in the history classrooms, but + + + align:start position:0% +put them in the history classrooms, but +they put them in the math classrooms, + + align:start position:0% +they put them in the math classrooms, + + + align:start position:0% +they put them in the math classrooms, +they put them in the science classrooms. + + align:start position:0% +they put them in the science classrooms. + + + align:start position:0% +they put them in the science classrooms. +Um and the intention was to to change + + align:start position:0% +Um and the intention was to to change + + + align:start position:0% +Um and the intention was to to change +the physical space in order to create + + align:start position:0% +the physical space in order to create + + + align:start position:0% +the physical space in order to create +certain kinds of learning environments + + align:start position:0% +certain kinds of learning environments + + + align:start position:0% +certain kinds of learning environments +and certain kinds of interactions there + + align:start position:0% +and certain kinds of interactions there + + + align:start position:0% +and certain kinds of interactions there +and there. Now, of course, um you can + + align:start position:0% +and there. Now, of course, um you can + + + align:start position:0% +and there. Now, of course, um you can +give a math lecture in a room like this, + + align:start position:0% +give a math lecture in a room like this, + + + align:start position:0% +give a math lecture in a room like this, +but it's but it's hard to lecture for 52 + + align:start position:0% +but it's but it's hard to lecture for 52 + + + align:start position:0% +but it's but it's hard to lecture for 52 +minutes, you know, if you're standing + + align:start position:0% +minutes, you know, if you're standing + + + align:start position:0% +minutes, you know, if you're standing +here and half the kids either have their + + align:start position:0% +here and half the kids either have their + + + align:start position:0% +here and half the kids either have their +backs to you or have to, you know, + + align:start position:0% +backs to you or have to, you know, + + + align:start position:0% +backs to you or have to, you know, +rotate around or other kinds of things + + align:start position:0% +rotate around or other kinds of things + + + align:start position:0% +rotate around or other kinds of things +like that. Um it's it's designed to make + + align:start position:0% +like that. Um it's it's designed to make + + + align:start position:0% +like that. Um it's it's designed to make +people do that. So you can sort of think + + align:start position:0% +people do that. So you can sort of think + + + align:start position:0% +people do that. So you can sort of think +about like what are the you know h what + + align:start position:0% +about like what are the you know h what + + + align:start position:0% +about like what are the you know h what +are what you know what uh what agenda + + align:start position:0% +are what you know what uh what agenda + + + align:start position:0% +are what you know what uh what agenda +does this online space have for its + + align:start position:0% +does this online space have for its + + + align:start position:0% +does this online space have for its +occupants? Um what is it that a can that + + align:start position:0% +occupants? Um what is it that a can that + + + align:start position:0% +occupants? Um what is it that a can that +a sort of generic canvas classroom tells + + align:start position:0% +a sort of generic canvas classroom tells + + + align:start position:0% +a sort of generic canvas classroom tells +instructors and students that they're + + align:start position:0% +instructors and students that they're + + + align:start position:0% +instructors and students that they're +supposed to do? + + align:start position:0% +supposed to do? + + + align:start position:0% +supposed to do? +Um the you can look at these links + + align:start position:0% +Um the you can look at these links + + + align:start position:0% +Um the you can look at these links +later, but these are two of the folks + + align:start position:0% +later, but these are two of the folks + + + align:start position:0% +later, but these are two of the folks +who um as as as Blackboard was sort of + + align:start position:0% +who um as as as Blackboard was sort of + + + align:start position:0% +who um as as as Blackboard was sort of +sweeping higher education were uh um uh + + align:start position:0% +sweeping higher education were uh um uh + + + align:start position:0% +sweeping higher education were uh um uh +amongst the most active in trying to + + align:start position:0% +amongst the most active in trying to + + + align:start position:0% +amongst the most active in trying to +have these conversations. There was a + + align:start position:0% +have these conversations. There was a + + + align:start position:0% +have these conversations. There was a +book um that was written about them uh + + align:start position:0% +book um that was written about them uh + + + align:start position:0% +book um that was written about them uh +and some other people called Edupunks um + + align:start position:0% +and some other people called Edupunks um + + + align:start position:0% +and some other people called Edupunks um +and uh trying to make connection between + + align:start position:0% +and uh trying to make connection between + + + align:start position:0% +and uh trying to make connection between +the the punk movement and music um you + + align:start position:0% +the the punk movement and music um you + + + align:start position:0% +the the punk movement and music um you +know very sort of like countercultural + + align:start position:0% +know very sort of like countercultural + + + align:start position:0% +know very sort of like countercultural +do-it-yourself + + align:start position:0% +do-it-yourself + + + align:start position:0% +do-it-yourself +um you know uh kind of stand up to the + + align:start position:0% +um you know uh kind of stand up to the + + + align:start position:0% +um you know uh kind of stand up to the +man sort of thing um and folks like the + + align:start position:0% +man sort of thing um and folks like the + + + align:start position:0% +man sort of thing um and folks like the +Reverend Jim Groom um and Alan Cogdon + + align:start position:0% +Reverend Jim Groom um and Alan Cogdon + + + align:start position:0% +Reverend Jim Groom um and Alan Cogdon +living you know they have they have + + align:start position:0% +living you know they have they have + + + align:start position:0% +living you know they have they have +these monikers because if you were + + align:start position:0% +these monikers because if you were + + + align:start position:0% +these monikers because if you were +participating in social networks you + + align:start position:0% +participating in social networks you + + + align:start position:0% +participating in social networks you +create handles for those kinds of things + + align:start position:0% +create handles for those kinds of things + + + align:start position:0% +create handles for those kinds of things +but also Reverend Jim Groom was a bit a + + align:start position:0% +but also Reverend Jim Groom was a bit a + + + align:start position:0% +but also Reverend Jim Groom was a bit a +profit of such things. + + align:start position:0% +profit of such things. + + + align:start position:0% +profit of such things. +Um so what what these systems really + + align:start position:0% +Um so what what these systems really + + + align:start position:0% +Um so what what these systems really +allow um is a certain kind of + + align:start position:0% +allow um is a certain kind of + + + align:start position:0% +allow um is a certain kind of +coordination. Um it becomes very very + + align:start position:0% +coordination. Um it becomes very very + + + align:start position:0% +coordination. Um it becomes very very +easy to say all the faculty are going to + + align:start position:0% +easy to say all the faculty are going to + + + align:start position:0% +easy to say all the faculty are going to +have a page. Um you're all going to + + align:start position:0% +have a page. Um you're all going to + + + align:start position:0% +have a page. Um you're all going to +create at the same time. It's going to + + align:start position:0% +create at the same time. It's going to + + + align:start position:0% +create at the same time. It's going to +be automatically generated for you at + + align:start position:0% +be automatically generated for you at + + + align:start position:0% +be automatically generated for you at +the beginning of the semester. Even if + + align:start position:0% +the beginning of the semester. Even if + + + align:start position:0% +the beginning of the semester. Even if +you don't like computers, we're still + + align:start position:0% +you don't like computers, we're still + + + align:start position:0% +you don't like computers, we're still +going to be able to make you do it + + align:start position:0% +going to be able to make you do it + + + align:start position:0% +going to be able to make you do it +because it's not that hard. Um but there + + align:start position:0% +because it's not that hard. Um but there + + + align:start position:0% +because it's not that hard. Um but there +are a couple of characteristics of it + + align:start position:0% +are a couple of characteristics of it + + + align:start position:0% +are a couple of characteristics of it +that I think are not so good. I've + + align:start position:0% +that I think are not so good. I've + + + align:start position:0% +that I think are not so good. I've +talked mostly about the sort of stamped + + align:start position:0% +talked mostly about the sort of stamped + + + align:start position:0% +talked mostly about the sort of stamped +piece of it. Um + + align:start position:0% +piece of it. Um + + + align:start position:0% +piece of it. Um +uh there's there's a way in which um the + + align:start position:0% +uh there's there's a way in which um the + + + align:start position:0% +uh there's there's a way in which um the +control of all of the learning artifacts + + align:start position:0% +control of all of the learning artifacts + + + align:start position:0% +control of all of the learning artifacts +is with the institution and not the + + align:start position:0% +is with the institution and not the + + + align:start position:0% +is with the institution and not the +people. Um, so imagine imagine an + + align:start position:0% +people. Um, so imagine imagine an + + + align:start position:0% +people. Um, so imagine imagine an +infrastructure for um online learning + + align:start position:0% +infrastructure for um online learning + + + align:start position:0% +infrastructure for um online learning +and higher education where you didn't + + align:start position:0% +and higher education where you didn't + + + align:start position:0% +and higher education where you didn't +put all the stuff on someone else's web + + align:start position:0% +put all the stuff on someone else's web + + + align:start position:0% +put all the stuff on someone else's web +page, you put it on your own web page. + + align:start position:0% +page, you put it on your own web page. + + + align:start position:0% +page, you put it on your own web page. +Like what if when you went to do + + align:start position:0% +Like what if when you went to do + + + align:start position:0% +Like what if when you went to do +homework, you went to do writing, you + + align:start position:0% +homework, you went to do writing, you + + + align:start position:0% +homework, you went to do writing, you +went to ask questions, it didn't show up + + align:start position:0% +went to ask questions, it didn't show up + + + align:start position:0% +went to ask questions, it didn't show up +on the school's Canvas site, which you + + align:start position:0% +on the school's Canvas site, which you + + + align:start position:0% +on the school's Canvas site, which you +don't care about, but it was on your + + align:start position:0% +don't care about, but it was on your + + + align:start position:0% +don't care about, but it was on your +site in some kind of way. It was in some + + align:start position:0% +site in some kind of way. It was in some + + + align:start position:0% +site in some kind of way. It was in some +sort of space that you controlled. And + + align:start position:0% +sort of space that you controlled. And + + + align:start position:0% +sort of space that you controlled. And +then the thing that was always craziest + + align:start position:0% +then the thing that was always craziest + + + align:start position:0% +then the thing that was always craziest +to me about these sites is that we + + align:start position:0% +to me about these sites is that we + + + align:start position:0% +to me about these sites is that we +delete them every 18 months. Um, you + + align:start position:0% +delete them every 18 months. Um, you + + + align:start position:0% +delete them every 18 months. Um, you +know, it's a it's a strange thing to go + + align:start position:0% +know, it's a it's a strange thing to go + + + align:start position:0% +know, it's a it's a strange thing to go +to students and be like, "Please pour in + + align:start position:0% +to students and be like, "Please pour in + + + align:start position:0% +to students and be like, "Please pour in +um your best, most thoughtful, most + + align:start position:0% +um your best, most thoughtful, most + + + align:start position:0% +um your best, most thoughtful, most +interesting words, ideas." Um, oh, and + + align:start position:0% +interesting words, ideas." Um, oh, and + + + align:start position:0% +interesting words, ideas." Um, oh, and +by the way, nine months from now, + + align:start position:0% +by the way, nine months from now, + + + align:start position:0% +by the way, nine months from now, +they're going to be automatically + + align:start position:0% +they're going to be automatically + + + align:start position:0% +they're going to be automatically +deleted. Um, that's a that's a sort of + + align:start position:0% +deleted. Um, that's a that's a sort of + + + align:start position:0% +deleted. Um, that's a that's a sort of +strange feature to me of a of an online + + align:start position:0% +strange feature to me of a of an online + + + align:start position:0% +strange feature to me of a of an online +learning environment. Um, + + align:start position:0% +learning environment. Um, + + + align:start position:0% +learning environment. Um, +uh, so so me and other folks for a while + + align:start position:0% +uh, so so me and other folks for a while + + + align:start position:0% +uh, so so me and other folks for a while +were really interested in like, well, + + align:start position:0% +were really interested in like, well, + + + align:start position:0% +were really interested in like, well, +what would an alternative to this look + + align:start position:0% +what would an alternative to this look + + + align:start position:0% +what would an alternative to this look +like? um what would be what would be + + align:start position:0% +like? um what would be what would be + + + align:start position:0% +like? um what would be what would be +something um that was not Blackboard + + align:start position:0% +something um that was not Blackboard + + + align:start position:0% +something um that was not Blackboard +that was not Canvas um that still could + + align:start position:0% +that was not Canvas um that still could + + + align:start position:0% +that was not Canvas um that still could +have coordination um but it would let it + + align:start position:0% +have coordination um but it would let it + + + align:start position:0% +have coordination um but it would let it +would have some of these characteristics + + align:start position:0% +would have some of these characteristics + + + align:start position:0% +would have some of these characteristics +that the sort of web 2.0 open web + + align:start position:0% +that the sort of web 2.0 open web + + + align:start position:0% +that the sort of web 2.0 open web +movement had like it let students own + + align:start position:0% +movement had like it let students own + + + align:start position:0% +movement had like it let students own +their own stuff um it helped them + + align:start position:0% +their own stuff um it helped them + + + align:start position:0% +their own stuff um it helped them +develop some technology proficiency. It + + align:start position:0% +develop some technology proficiency. It + + + align:start position:0% +develop some technology proficiency. It +connected people um to each other and to + + align:start position:0% +connected people um to each other and to + + + align:start position:0% +connected people um to each other and to +their work. It didn't just like hoover + + align:start position:0% +their work. It didn't just like hoover + + + align:start position:0% +their work. It didn't just like hoover +up your stuff, churn it through, grade + + align:start position:0% +up your stuff, churn it through, grade + + + align:start position:0% +up your stuff, churn it through, grade +it, and delete it, but it would be like + + align:start position:0% +it, and delete it, but it would be like + + + align:start position:0% +it, and delete it, but it would be like +something that you owned and cared about + + align:start position:0% +something that you owned and cared about + + + align:start position:0% +something that you owned and cared about +for a while. Um, + + align:start position:0% +for a while. Um, + + + align:start position:0% +for a while. Um, +uh, those are ice cream sandwiches. Um, + + align:start position:0% +uh, those are ice cream sandwiches. Um, + + + align:start position:0% +uh, those are ice cream sandwiches. Um, +uh, yeah. Good. Yeah. So, it's a good + + align:start position:0% +uh, yeah. Good. Yeah. So, it's a good + + + align:start position:0% +uh, yeah. Good. Yeah. So, it's a good +it's a good picture. It, you know, it + + align:start position:0% +it's a good picture. It, you know, it + + + align:start position:0% +it's a good picture. It, you know, it +definitely evokes some of these kinds of + + align:start position:0% +definitely evokes some of these kinds of + + + align:start position:0% +definitely evokes some of these kinds of +pictures. Like some of these kinds of + + align:start position:0% +pictures. Like some of these kinds of + + + align:start position:0% +pictures. Like some of these kinds of +pictures sort of ended up on like + + align:start position:0% +pictures sort of ended up on like + + + align:start position:0% +pictures sort of ended up on like +professor Twitter handles in the 2013. + + align:start position:0% +professor Twitter handles in the 2013. + + + align:start position:0% +professor Twitter handles in the 2013. +Um, I didn't make that picture. I had + + align:start position:0% +Um, I didn't make that picture. I had + + + align:start position:0% +Um, I didn't make that picture. I had +one semester um where I don't know some + + align:start position:0% +one semester um where I don't know some + + + align:start position:0% +one semester um where I don't know some +students just were like enjoying class + + align:start position:0% +students just were like enjoying class + + + align:start position:0% +students just were like enjoying class +and they sent me a whole bunch of p I + + align:start position:0% +and they sent me a whole bunch of p I + + + align:start position:0% +and they sent me a whole bunch of p I +don't know how quickly can I find these + + align:start position:0% +don't know how quickly can I find these + + + align:start position:0% +don't know how quickly can I find these +things. + + align:start position:0% +things. + + + align:start position:0% +things. +Um there's one of + + align:start position:0% +Um there's one of + + + align:start position:0% +Um there's one of +me. + + align:start position:0% + + + + align:start position:0% + +Uh are these going to be on here? + + align:start position:0% +Uh are these going to be on here? + + + align:start position:0% +Uh are these going to be on here? +Um. H there's a few. There's like this + + align:start position:0% + + + + align:start position:0% + +one. This one. Oh, no. That's a real + + align:start position:0% +one. This one. Oh, no. That's a real + + + align:start position:0% +one. This one. Oh, no. That's a real +one. Justin is LeBron James. A little + + align:start position:0% +one. Justin is LeBron James. A little + + + align:start position:0% +one. Justin is LeBron James. A little +little dicey to be doing this one these + + align:start position:0% +little dicey to be doing this one these + + + align:start position:0% +little dicey to be doing this one these +days. I don't You probably wouldn't uh + + align:start position:0% +days. I don't You probably wouldn't uh + + + align:start position:0% +days. I don't You probably wouldn't uh +you probably wouldn't put white Justin + + align:start position:0% +you probably wouldn't put white Justin + + + align:start position:0% +you probably wouldn't put white Justin +into a black body anymore, but uh back + + align:start position:0% +into a black body anymore, but uh back + + + align:start position:0% +into a black body anymore, but uh back +in the day. Um yeah, I don't for one day + + align:start position:0% +in the day. Um yeah, I don't for one day + + + align:start position:0% +in the day. Um yeah, I don't for one day +for class uh I think something terrible + + align:start position:0% +for class uh I think something terrible + + + align:start position:0% +for class uh I think something terrible +had happened in the world and I made + + align:start position:0% +had happened in the world and I made + + + align:start position:0% +had happened in the world and I made +them ice cream sandwiches one day for + + align:start position:0% +them ice cream sandwiches one day for + + + align:start position:0% +them ice cream sandwiches one day for +class and so they uh um they made that + + align:start position:0% +class and so they uh um they made that + + + align:start position:0% +class and so they uh um they made that +picture there. + + align:start position:0% + + + + align:start position:0% + +It was for + + align:start position:0% +It was for + + + align:start position:0% +It was for +a we're get we're getting to the real + + align:start position:0% +a we're get we're getting to the real + + + align:start position:0% +a we're get we're getting to the real +issues + + align:start position:0% +issues + + + align:start position:0% +issues +now. I think that I went to the + + align:start position:0% +now. I think that I went to the + + + align:start position:0% +now. I think that I went to the +International Society and Technology and + + align:start position:0% +International Society and Technology and + + + align:start position:0% +International Society and Technology and +Education conference and they basically + + align:start position:0% +Education conference and they basically + + + align:start position:0% +Education conference and they basically +grabbed a bunch of random people and + + align:start position:0% +grabbed a bunch of random people and + + + align:start position:0% +grabbed a bunch of random people and +took them to a photo shoot to generate + + align:start position:0% +took them to a photo shoot to generate + + + align:start position:0% +took them to a photo shoot to generate +their own stock photos. Um they they + + align:start position:0% +their own stock photos. Um they they + + + align:start position:0% +their own stock photos. Um they they +want they wanted to have a whole set of + + align:start position:0% +want they wanted to have a whole set of + + + align:start position:0% +want they wanted to have a whole set of +stock photos that were from the + + align:start position:0% +stock photos that were from the + + + align:start position:0% +stock photos that were from the +membership of this organization. And so + + align:start position:0% +membership of this organization. And so + + + align:start position:0% +membership of this organization. And so +it was just like I don't think I was + + align:start position:0% +it was just like I don't think I was + + + align:start position:0% +it was just like I don't think I was +holding any I think I I mean I like you + + align:start position:0% +holding any I think I I mean I like you + + + align:start position:0% +holding any I think I I mean I like you +could imagine this is like generic + + align:start position:0% +could imagine this is like generic + + + align:start position:0% +could imagine this is like generic +invitation to kind of thing. Um, but + + align:start position:0% +invitation to kind of thing. Um, but + + + align:start position:0% +invitation to kind of thing. Um, but +that's where all that came from. + + align:start position:0% +that's where all that came from. + + + align:start position:0% +that's where all that came from. +Um, is is this worth your learning time? + + align:start position:0% +Um, is is this worth your learning time? + + + align:start position:0% +Um, is is this worth your learning time? +Hard to say, but it's pretty fun. Okay, + + align:start position:0% +Hard to say, but it's pretty fun. Okay, + + + align:start position:0% +Hard to say, but it's pretty fun. Okay, +this you should remember a little bit. + + align:start position:0% +this you should remember a little bit. + + + align:start position:0% +this you should remember a little bit. +Um, this is another this is another + + align:start position:0% +Um, this is another this is another + + + align:start position:0% +Um, this is another this is another +branch of um uh of constructionism. You + + align:start position:0% +branch of um uh of constructionism. You + + + align:start position:0% +branch of um uh of constructionism. You +know, these ideas just repeat + + align:start position:0% +know, these ideas just repeat + + + align:start position:0% +know, these ideas just repeat +themselves. They get reinvented over and + + align:start position:0% +themselves. They get reinvented over and + + + align:start position:0% +themselves. They get reinvented over and +over again. um these two Canadian + + align:start position:0% +over again. um these two Canadian + + + align:start position:0% +over again. um these two Canadian +educators, people who sort of founded + + align:start position:0% +educators, people who sort of founded + + + align:start position:0% +educators, people who sort of founded +the 2007208 original mass of open online + + align:start position:0% +the 2007208 original mass of open online + + + align:start position:0% +the 2007208 original mass of open online +courses and they had this idea called + + align:start position:0% +courses and they had this idea called + + + align:start position:0% +courses and they had this idea called +connectivism. Um and they said, you + + align:start position:0% +connectivism. Um and they said, you + + + align:start position:0% +connectivism. Um and they said, you +know, part of the problem with learning + + align:start position:0% +know, part of the problem with learning + + + align:start position:0% +know, part of the problem with learning +theory is that it thinks that learning + + align:start position:0% +theory is that it thinks that learning + + + align:start position:0% +theory is that it thinks that learning +happens and knowledge exists inside + + align:start position:0% +happens and knowledge exists inside + + + align:start position:0% +happens and knowledge exists inside +people's heads. But learning and + + align:start position:0% +people's heads. But learning and + + + align:start position:0% +people's heads. But learning and +knowledge really exists between people + + align:start position:0% +knowledge really exists between people + + + align:start position:0% +knowledge really exists between people +more than exists within people. Um + + align:start position:0% +more than exists within people. Um + + + align:start position:0% +more than exists within people. Um +there's a famous line which is which you + + align:start position:0% +there's a famous line which is which you + + + align:start position:0% +there's a famous line which is which you +probably all would agree with in some + + align:start position:0% +probably all would agree with in some + + + align:start position:0% +probably all would agree with in some +way that the smartest person in the room + + align:start position:0% +way that the smartest person in the room + + + align:start position:0% +way that the smartest person in the room +is the room. Um that like the collective + + align:start position:0% +is the room. Um that like the collective + + + align:start position:0% +is the room. Um that like the collective +capacity of people is where kind of the + + align:start position:0% +capacity of people is where kind of the + + + align:start position:0% +capacity of people is where kind of the +heart of art intelligence is like + + align:start position:0% +heart of art intelligence is like + + + align:start position:0% +heart of art intelligence is like +connectivism almost went further and + + align:start position:0% +connectivism almost went further and + + + align:start position:0% +connectivism almost went further and +said like maybe the only intelligence in + + align:start position:0% +said like maybe the only intelligence in + + + align:start position:0% +said like maybe the only intelligence in +the room is the room. Um maybe your + + align:start position:0% +the room is the room. Um maybe your + + + align:start position:0% +the room is the room. Um maybe your +knowledge your understanding like + + align:start position:0% +knowledge your understanding like + + + align:start position:0% +knowledge your understanding like +doesn't exist without social convention + + align:start position:0% +doesn't exist without social convention + + + align:start position:0% +doesn't exist without social convention +like language um like culture other + + align:start position:0% +like language um like culture other + + + align:start position:0% +like language um like culture other +kinds of things like that. Um so this + + align:start position:0% +kinds of things like that. Um so this + + + align:start position:0% +kinds of things like that. Um so this +was so this was at first an educational + + align:start position:0% +was so this was at first an educational + + + align:start position:0% +was so this was at first an educational +philosophy. Um may you know may maybe it + + align:start position:0% +philosophy. Um may you know may maybe it + + + align:start position:0% +philosophy. Um may you know may maybe it +was a maybe it was an epistemology maybe + + align:start position:0% +was a maybe it was an epistemology maybe + + + align:start position:0% +was a maybe it was an epistemology maybe +it was a philosophy of knowledge but + + align:start position:0% +it was a philosophy of knowledge but + + + align:start position:0% +it was a philosophy of knowledge but +then it got translated into these + + align:start position:0% +then it got translated into these + + + align:start position:0% +then it got translated into these +pedagogical ideas. Um and the + + align:start position:0% +pedagogical ideas. Um and the + + + align:start position:0% +pedagogical ideas. Um and the +pedagogical ideas were say what if you + + align:start position:0% +pedagogical ideas were say what if you + + + align:start position:0% +pedagogical ideas were say what if you +defined courses where their primary + + align:start position:0% +defined courses where their primary + + + align:start position:0% +defined courses where their primary +value was creating connections between + + align:start position:0% +value was creating connections between + + + align:start position:0% +value was creating connections between +people and ideas. Um uh one of one of + + align:start position:0% +people and ideas. Um uh one of one of + + + align:start position:0% +people and ideas. Um uh one of one of +the things Stephen D said about this + + align:start position:0% +the things Stephen D said about this + + + align:start position:0% +the things Stephen D said about this +which you'll find it very connected to + + align:start position:0% +which you'll find it very connected to + + + align:start position:0% +which you'll find it very connected to +situated learning um he says you know + + align:start position:0% +situated learning um he says you know + + + align:start position:0% +situated learning um he says you know +like if you become a physicist what + + align:start position:0% +like if you become a physicist what + + + align:start position:0% +like if you become a physicist what +happens um well like you read physics + + align:start position:0% +happens um well like you read physics + + + align:start position:0% +happens um well like you read physics +papers and you follow new ideas in + + align:start position:0% +papers and you follow new ideas in + + + align:start position:0% +papers and you follow new ideas in +physics and you figure out where + + align:start position:0% +physics and you figure out where + + + align:start position:0% +physics and you figure out where +physicists talk to each other and like + + align:start position:0% +physicists talk to each other and like + + + align:start position:0% +physicists talk to each other and like +where the physics lounge is um and which + + align:start position:0% +where the physics lounge is um and which + + + align:start position:0% +where the physics lounge is um and which +physics conferences to go to I don't + + align:start position:0% +physics conferences to go to I don't + + + align:start position:0% +physics conferences to go to I don't +know what music physicists like what + + align:start position:0% +know what music physicists like what + + + align:start position:0% +know what music physicists like what +television shows they find funny all + + align:start position:0% +television shows they find funny all + + + align:start position:0% +television shows they find funny all +these kinds of things like that is as + + align:start position:0% +these kinds of things like that is as + + + align:start position:0% +these kinds of things like that is as +much a part of becoming a physicist as + + align:start position:0% +much a part of becoming a physicist as + + + align:start position:0% +much a part of becoming a physicist as +learning formulas and theories and + + align:start position:0% +learning formulas and theories and + + + align:start position:0% +learning formulas and theories and +knowledge and things like that. What if + + align:start position:0% +knowledge and things like that. What if + + + align:start position:0% +knowledge and things like that. What if +we had educational systems that took + + align:start position:0% +we had educational systems that took + + + align:start position:0% +we had educational systems that took +that really seriously? Like the job of a + + align:start position:0% +that really seriously? Like the job of a + + + align:start position:0% +that really seriously? Like the job of a +physics class is not just to have you, + + align:start position:0% +physics class is not just to have you, + + + align:start position:0% +physics class is not just to have you, +you know, be able to learn some formulas + + align:start position:0% +you know, be able to learn some formulas + + + align:start position:0% +you know, be able to learn some formulas +about Newton's three laws, but to + + align:start position:0% +about Newton's three laws, but to + + + align:start position:0% +about Newton's three laws, but to +connect to other physicists. That's kind + + align:start position:0% +connect to other physicists. That's kind + + + align:start position:0% +connect to other physicists. That's kind +of that's kind of a cool idea. Um, uh, + + align:start position:0% +of that's kind of a cool idea. Um, uh, + + + align:start position:0% +of that's kind of a cool idea. Um, uh, +Ste, one of the most radical things + + align:start position:0% +Ste, one of the most radical things + + + align:start position:0% +Ste, one of the most radical things +Steven DS ever said, he said something + + align:start position:0% +Steven DS ever said, he said something + + + align:start position:0% +Steven DS ever said, he said something +along the lines of, "In my class, the + + align:start position:0% +along the lines of, "In my class, the + + + align:start position:0% +along the lines of, "In my class, the +content is McGuffin." Um, a mcguffin is + + align:start position:0% +content is McGuffin." Um, a mcguffin is + + + align:start position:0% +content is McGuffin." Um, a mcguffin is +the thing in a movie that's not really + + align:start position:0% +the thing in a movie that's not really + + + align:start position:0% +the thing in a movie that's not really +important that drives the plot forward. + + align:start position:0% +important that drives the plot forward. + + + align:start position:0% +important that drives the plot forward. +Um, it's the briefcase that gets + + align:start position:0% +Um, it's the briefcase that gets + + + align:start position:0% +Um, it's the briefcase that gets +switched in the beginning which helps + + align:start position:0% +switched in the beginning which helps + + + align:start position:0% +switched in the beginning which helps +two people fall in love with each other + + align:start position:0% +two people fall in love with each other + + + align:start position:0% +two people fall in love with each other +or something like that. Um, the mcguffin + + align:start position:0% +or something like that. Um, the mcguffin + + + align:start position:0% +or something like that. Um, the mcguffin +is the thing that you're sort of chasing + + align:start position:0% +is the thing that you're sort of chasing + + + align:start position:0% +is the thing that you're sort of chasing +to make the plot move forward. This is a + + align:start position:0% +to make the plot move forward. This is a + + + align:start position:0% +to make the plot move forward. This is a +radical statement for an educator. The + + align:start position:0% +radical statement for an educator. The + + + align:start position:0% +radical statement for an educator. The +content is a mcguffin. The thing that I + + align:start position:0% +content is a mcguffin. The thing that I + + + align:start position:0% +content is a mcguffin. The thing that I +told you the class is about as a trick. + + align:start position:0% +told you the class is about as a trick. + + + align:start position:0% +told you the class is about as a trick. +The real part of the class is getting + + align:start position:0% +The real part of the class is getting + + + align:start position:0% +The real part of the class is getting +you connected to each other, to things + + align:start position:0% +you connected to each other, to things + + + align:start position:0% +you connected to each other, to things +that you're interested in, to other + + align:start position:0% +that you're interested in, to other + + + align:start position:0% +that you're interested in, to other +kinds of expertise is a very radical set + + align:start position:0% +kinds of expertise is a very radical set + + + align:start position:0% +kinds of expertise is a very radical set +of ideas. Um, and there are a lot of + + align:start position:0% +of ideas. Um, and there are a lot of + + + align:start position:0% +of ideas. Um, and there are a lot of +people who are sort of um profoundly + + align:start position:0% +people who are sort of um profoundly + + + align:start position:0% +people who are sort of um profoundly +influenced by them. Um, and people + + align:start position:0% +influenced by them. Um, and people + + + align:start position:0% +influenced by them. Um, and people +trying to say like, yeah, well, what + + align:start position:0% +trying to say like, yeah, well, what + + + align:start position:0% +trying to say like, yeah, well, what +what could some like genuine alternative + + align:start position:0% +what could some like genuine alternative + + + align:start position:0% +what could some like genuine alternative +architecture to canvas um that embraced + + align:start position:0% +architecture to canvas um that embraced + + + align:start position:0% +architecture to canvas um that embraced +some of these ideas of the open web, of + + align:start position:0% +some of these ideas of the open web, of + + + align:start position:0% +some of these ideas of the open web, of +web 2.0, of connectism, what might it + + align:start position:0% +web 2.0, of connectism, what might it + + + align:start position:0% +web 2.0, of connectism, what might it +look like? Um, and so this no longer + + align:start position:0% +look like? Um, and so this no longer + + + align:start position:0% +look like? Um, and so this no longer +exists. I don't I don't think either of + + align:start position:0% +exists. I don't I don't think either of + + + align:start position:0% +exists. I don't I don't think either of +those links are live anymore. Um, but + + align:start position:0% +those links are live anymore. Um, but + + + align:start position:0% +those links are live anymore. Um, but +this is what the website for this class, + + align:start position:0% +this is what the website for this class, + + + align:start position:0% +this is what the website for this class, +um, or an earlier version of this class + + align:start position:0% +um, or an earlier version of this class + + + align:start position:0% +um, or an earlier version of this class +used to look like. Um, and here's how + + align:start position:0% +used to look like. Um, and here's how + + + align:start position:0% +used to look like. Um, and here's how +the infrastructure of it worked. Um, at + + align:start position:0% +the infrastructure of it worked. Um, at + + + align:start position:0% +the infrastructure of it worked. Um, at +the beginning of class, um, folks were + + align:start position:0% +the beginning of class, um, folks were + + + align:start position:0% +the beginning of class, um, folks were +assigned to create spaces where they + + align:start position:0% +assigned to create spaces where they + + + align:start position:0% +assigned to create spaces where they +would do the work of this class. Um, so + + align:start position:0% +would do the work of this class. Um, so + + + align:start position:0% +would do the work of this class. Um, so +you wouldn't have a learning journal. + + align:start position:0% +you wouldn't have a learning journal. + + + align:start position:0% +you wouldn't have a learning journal. +You wouldn't have like a Canvas + + align:start position:0% +You wouldn't have like a Canvas + + + align:start position:0% +You wouldn't have like a Canvas +discussion page or something like that. + + align:start position:0% +discussion page or something like that. + + + align:start position:0% +discussion page or something like that. +Go make your own blog. Go make your own + + align:start position:0% +Go make your own blog. Go make your own + + + align:start position:0% +Go make your own blog. Go make your own +Tumblr page. Go make your own Twitter + + align:start position:0% +Tumblr page. Go make your own Twitter + + + align:start position:0% +Tumblr page. Go make your own Twitter +feed. Go make your own Flickr page. Make + + align:start position:0% +feed. Go make your own Flickr page. Make + + + align:start position:0% +feed. Go make your own Flickr page. Make +all kinds of other things like that. Um, + + align:start position:0% +all kinds of other things like that. Um, + + + align:start position:0% +all kinds of other things like that. Um, +and do all of the work for this class in + + align:start position:0% +and do all of the work for this class in + + + align:start position:0% +and do all of the work for this class in +your own space. Now, one problem with + + align:start position:0% +your own space. Now, one problem with + + + align:start position:0% +your own space. Now, one problem with +that is that nobody can find that stuff + + align:start position:0% +that is that nobody can find that stuff + + + align:start position:0% +that is that nobody can find that stuff +anymore. Now, it's all sort of on other + + align:start position:0% +anymore. Now, it's all sort of on other + + + align:start position:0% +anymore. Now, it's all sort of on other +people's things. But that's a solvable + + align:start position:0% +people's things. But that's a solvable + + + align:start position:0% +people's things. But that's a solvable +problem. Um, because we're going to + + align:start position:0% +problem. Um, because we're going to + + + align:start position:0% +problem. Um, because we're going to +build this thing called the syndication + + align:start position:0% +build this thing called the syndication + + + align:start position:0% +build this thing called the syndication +bus. Um and the syndication bus is gonna + + align:start position:0% +bus. Um and the syndication bus is gonna + + + align:start position:0% +bus. Um and the syndication bus is gonna +depend on this technology which how many + + align:start position:0% +depend on this technology which how many + + + align:start position:0% +depend on this technology which how many +of you are familiar with real simple + + align:start position:0% +of you are familiar with real simple + + + align:start position:0% +of you are familiar with real simple +syndication. Is that something that you + + align:start position:0% +syndication. Is that something that you + + + align:start position:0% +syndication. Is that something that you +like you like vaguely know exists? So + + align:start position:0% +like you like vaguely know exists? So + + + align:start position:0% +like you like vaguely know exists? So +again 10 or 15 years ago um this was + + align:start position:0% +again 10 or 15 years ago um this was + + + align:start position:0% +again 10 or 15 years ago um this was +considered like an essential part of the + + align:start position:0% +considered like an essential part of the + + + align:start position:0% +considered like an essential part of the +web and there are many people would have + + align:start position:0% +web and there are many people would have + + + align:start position:0% +web and there are many people would have +told you like this is the future of of + + align:start position:0% +told you like this is the future of of + + + align:start position:0% +told you like this is the future of of +how people will find things. So before + + align:start position:0% +how people will find things. So before + + + align:start position:0% +how people will find things. So before +um you know Jiren was telling us before + + align:start position:0% +um you know Jiren was telling us before + + + align:start position:0% +um you know Jiren was telling us before +about the YouTube algorithm kind of + + align:start position:0% +about the YouTube algorithm kind of + + + align:start position:0% +about the YouTube algorithm kind of +controlling what he watches and what he + + align:start position:0% +controlling what he watches and what he + + + align:start position:0% +controlling what he watches and what he +finds and things like that. An + + align:start position:0% +finds and things like that. An + + + align:start position:0% +finds and things like that. An +alternative to that was you subscribe to + + align:start position:0% +alternative to that was you subscribe to + + + align:start position:0% +alternative to that was you subscribe to +a series of feeds. Um so you would like + + align:start position:0% +a series of feeds. Um so you would like + + + align:start position:0% +a series of feeds. Um so you would like +find all the bloggers that you like or + + align:start position:0% +find all the bloggers that you like or + + + align:start position:0% +find all the bloggers that you like or +all the video bloggers you like or + + align:start position:0% +all the video bloggers you like or + + + align:start position:0% +all the video bloggers you like or +whatever else. You would choose their + + align:start position:0% +whatever else. You would choose their + + + align:start position:0% +whatever else. You would choose their +feeds and then you would have you know + + align:start position:0% +feeds and then you would have you know + + + align:start position:0% +feeds and then you would have you know +one really popular technology was called + + align:start position:0% +one really popular technology was called + + + align:start position:0% +one really popular technology was called +Google Reader which just gave you the + + align:start position:0% +Google Reader which just gave you the + + + align:start position:0% +Google Reader which just gave you the +things that came out of those feeds. So + + align:start position:0% +things that came out of those feeds. So + + + align:start position:0% +things that came out of those feeds. So +instead of instead of being sort of like + + align:start position:0% +instead of instead of being sort of like + + + align:start position:0% +instead of instead of being sort of like +bounced around by an algorithm to things + + align:start position:0% +bounced around by an algorithm to things + + + align:start position:0% +bounced around by an algorithm to things +that people think are popular, + + align:start position:0% +that people think are popular, + + + align:start position:0% +that people think are popular, +interesting and things like that um you + + align:start position:0% +interesting and things like that um you + + + align:start position:0% +interesting and things like that um you +sort of have more control over that. So + + align:start position:0% +sort of have more control over that. So + + + align:start position:0% +sort of have more control over that. So +basically what we did um was everyone + + align:start position:0% +basically what we did um was everyone + + + align:start position:0% +basically what we did um was everyone +would create their own online space and + + align:start position:0% +would create their own online space and + + + align:start position:0% +would create their own online space and +then we would use this signification bus + + align:start position:0% +then we would use this signification bus + + + align:start position:0% +then we would use this signification bus +to aggregate all those things. So + + align:start position:0% +to aggregate all those things. So + + + align:start position:0% +to aggregate all those things. So +effectively um we would oh there + + align:start position:0% +effectively um we would oh there + + + align:start position:0% +effectively um we would oh there +um there's an animation there that's + + align:start position:0% +um there's an animation there that's + + + align:start position:0% +um there's an animation there that's +missing. Um, we would make a copy of + + align:start position:0% +missing. Um, we would make a copy of + + + align:start position:0% +missing. Um, we would make a copy of +each of these pieces and we would pull + + align:start position:0% +each of these pieces and we would pull + + + align:start position:0% +each of these pieces and we would pull +the copy into the syndication bus. So, + + align:start position:0% +the copy into the syndication bus. So, + + + align:start position:0% +the copy into the syndication bus. So, +you owned your own thing, but we would + + align:start position:0% +you owned your own thing, but we would + + + align:start position:0% +you owned your own thing, but we would +use RSS to grab one copy of those + + align:start position:0% +use RSS to grab one copy of those + + + align:start position:0% +use RSS to grab one copy of those +things. Um, and then we would aggregate + + align:start position:0% +things. Um, and then we would aggregate + + + align:start position:0% +things. Um, and then we would aggregate +them in different kinds of ways. Um, so, + + align:start position:0% +them in different kinds of ways. Um, so, + + + align:start position:0% +them in different kinds of ways. Um, so, +um, imagine if every time you wrote in + + align:start position:0% +um, imagine if every time you wrote in + + + align:start position:0% +um, imagine if every time you wrote in +your learning journal, you didn't just + + align:start position:0% +your learning journal, you didn't just + + + align:start position:0% +your learning journal, you didn't just +write in your own Google Slides, um, but + + align:start position:0% +write in your own Google Slides, um, but + + + align:start position:0% +write in your own Google Slides, um, but +you wrote on a blog, um, anybody could + + align:start position:0% +you wrote on a blog, um, anybody could + + + align:start position:0% +you wrote on a blog, um, anybody could +subscribe to that blog, but the course + + align:start position:0% +subscribe to that blog, but the course + + + align:start position:0% +subscribe to that blog, but the course +subscribed to the blog. um and sort of + + align:start position:0% +subscribed to the blog. um and sort of + + + align:start position:0% +subscribed to the blog. um and sort of +hoovered all of those things up into one + + align:start position:0% +hoovered all of those things up into one + + + align:start position:0% +hoovered all of those things up into one +space. Um you could also um teach people + + align:start position:0% +space. Um you could also um teach people + + + align:start position:0% +space. Um you could also um teach people +other ways of aggregating things like + + align:start position:0% +other ways of aggregating things like + + + align:start position:0% +other ways of aggregating things like +anytime in any of the spaces that you're + + align:start position:0% +anytime in any of the spaces that you're + + + align:start position:0% +anytime in any of the spaces that you're +working you share something that we + + align:start position:0% +working you share something that we + + + align:start position:0% +working you share something that we +might be interested tag it with T509 + + align:start position:0% +might be interested tag it with T509 + + + align:start position:0% +might be interested tag it with T509 +massive. Um and then what gets populated + + align:start position:0% +massive. Um and then what gets populated + + + align:start position:0% +massive. Um and then what gets populated +in this sort of syndication bust Twitter + + align:start position:0% +in this sort of syndication bust Twitter + + + align:start position:0% +in this sort of syndication bust Twitter +channel is like all the tweets that + + align:start position:0% +channel is like all the tweets that + + + align:start position:0% +channel is like all the tweets that +people have that are about T509 massive. + + align:start position:0% +people have that are about T509 massive. + + + align:start position:0% +people have that are about T509 massive. +Um there were + + align:start position:0% +Um there were + + + align:start position:0% +Um there were +uh the then um when you showed up on the + + align:start position:0% +uh the then um when you showed up on the + + + align:start position:0% +uh the then um when you showed up on the +homepage I as the instructor would pick + + align:start position:0% +homepage I as the instructor would pick + + + align:start position:0% +homepage I as the instructor would pick +a few of these things. So there was a + + align:start position:0% +a few of these things. So there was a + + + align:start position:0% +a few of these things. So there was a +section called the spotlight where I + + align:start position:0% +section called the spotlight where I + + + align:start position:0% +section called the spotlight where I +would sort of go through all the stuff + + align:start position:0% +would sort of go through all the stuff + + + align:start position:0% +would sort of go through all the stuff +that people were generating every week + + align:start position:0% +that people were generating every week + + + align:start position:0% +that people were generating every week +and pick a few things that I thought + + align:start position:0% +and pick a few things that I thought + + + align:start position:0% +and pick a few things that I thought +were like particularly interesting, + + align:start position:0% +were like particularly interesting, + + + align:start position:0% +were like particularly interesting, +particularly important, particularly + + align:start position:0% +particularly important, particularly + + + align:start position:0% +particularly important, particularly +funny, stuff like that, and sort of show + + align:start position:0% +funny, stuff like that, and sort of show + + + align:start position:0% +funny, stuff like that, and sort of show +them to people to feature them. + + align:start position:0% +them to people to feature them. + + + align:start position:0% +them to people to feature them. +Um and then uh that's probably kind of + + align:start position:0% +Um and then uh that's probably kind of + + + align:start position:0% +Um and then uh that's probably kind of +less important. Um, but then there were + + align:start position:0% +less important. Um, but then there were + + + align:start position:0% +less important. Um, but then there were +other spaces, you know, we I could + + align:start position:0% +other spaces, you know, we I could + + + align:start position:0% +other spaces, you know, we I could +create spaces that were about a + + align:start position:0% +create spaces that were about a + + + align:start position:0% +create spaces that were about a +particular assignment. Um, you could + + align:start position:0% +particular assignment. Um, you could + + + align:start position:0% +particular assignment. Um, you could +say, "Okay, everybody is working on your + + align:start position:0% +say, "Okay, everybody is working on your + + + align:start position:0% +say, "Okay, everybody is working on your +Oh, oh, I want to tell you about how I + + align:start position:0% +Oh, oh, I want to tell you about how I + + + align:start position:0% +Oh, oh, I want to tell you about how I +graded the class, but I could say, + + align:start position:0% +graded the class, but I could say, + + + align:start position:0% +graded the class, but I could say, +"Everybody create your rubric." Um, and + + align:start position:0% +"Everybody create your rubric." Um, and + + + align:start position:0% +"Everybody create your rubric." Um, and +then pull all of those things together, + + align:start position:0% +then pull all of those things together, + + + align:start position:0% +then pull all of those things together, +you know, like have a kind of rubric hub + + align:start position:0% +you know, like have a kind of rubric hub + + + align:start position:0% +you know, like have a kind of rubric hub +that everybody could see those things. + + align:start position:0% +that everybody could see those things. + + + align:start position:0% +that everybody could see those things. +And then we had a space, I think it was + + align:start position:0% +And then we had a space, I think it was + + + align:start position:0% +And then we had a space, I think it was +called the fire hose or something like + + align:start position:0% +called the fire hose or something like + + + align:start position:0% +called the fire hose or something like +that. Um, where it was everything that + + align:start position:0% +that. Um, where it was everything that + + + align:start position:0% +that. Um, where it was everything that +was coming in. Um there were probably 50 + + align:start position:0% +was coming in. Um there were probably 50 + + + align:start position:0% +was coming in. Um there were probably 50 +or 60 people who took this version of + + align:start position:0% +or 60 people who took this version of + + + align:start position:0% +or 60 people who took this version of +the class and so there was no way that + + align:start position:0% +the class and so there was no way that + + + align:start position:0% +the class and so there was no way that +everybody was going to read everything + + align:start position:0% +everybody was going to read everything + + + align:start position:0% +everybody was going to read everything +that everyone else did but like a part + + align:start position:0% +that everyone else did but like a part + + + align:start position:0% +that everyone else did but like a part +of class every week was finding out um + + align:start position:0% +of class every week was finding out um + + + align:start position:0% +of class every week was finding out um +who are you connected with who are you + + align:start position:0% +who are you connected with who are you + + + align:start position:0% +who are you connected with who are you +finding interesting who are you learning + + align:start position:0% +finding interesting who are you learning + + + align:start position:0% +finding interesting who are you learning +from like oh you four were English + + align:start position:0% +from like oh you four were English + + + align:start position:0% +from like oh you four were English +teachers before you came in like this + + align:start position:0% +teachers before you came in like this + + + align:start position:0% +teachers before you came in like this +class like you should beworked with each + + align:start position:0% +class like you should beworked with each + + + align:start position:0% +class like you should beworked with each +other moreover you should beworked to + + align:start position:0% +other moreover you should beworked to + + + align:start position:0% +other moreover you should beworked to +other English teachers um the things + + align:start position:0% +other English teachers um the things + + + align:start position:0% +other English teachers um the things +that you're generating like if you're + + align:start position:0% +that you're generating like if you're + + + align:start position:0% +that you're generating like if you're +putting a bunch of work into this class + + align:start position:0% +putting a bunch of work into this class + + + align:start position:0% +putting a bunch of work into this class +why just have it sit in a, you know, in + + align:start position:0% +why just have it sit in a, you know, in + + + align:start position:0% +why just have it sit in a, you know, in +a discussion form that no one's ever + + align:start position:0% +a discussion form that no one's ever + + + align:start position:0% +a discussion form that no one's ever +going to see again, like put it in this + + align:start position:0% +going to see again, like put it in this + + + align:start position:0% +going to see again, like put it in this +space where you can share with other + + align:start position:0% +space where you can share with other + + + align:start position:0% +space where you can share with other +people and stuff like that. Um, + + align:start position:0% +people and stuff like that. Um, + + + align:start position:0% +people and stuff like that. Um, +uh, + + align:start position:0% +uh, + + + align:start position:0% +uh, +one, you know, if you if you if you if + + align:start position:0% +one, you know, if you if you if you if + + + align:start position:0% +one, you know, if you if you if you if +you take this idea, um, of letting + + align:start position:0% +you take this idea, um, of letting + + + align:start position:0% +you take this idea, um, of letting +people choose how they want to share who + + align:start position:0% +people choose how they want to share who + + + align:start position:0% +people choose how they want to share who +they want to connect with sort of + + align:start position:0% +they want to connect with sort of + + + align:start position:0% +they want to connect with sort of +seriously, the more and more you get to + + align:start position:0% +seriously, the more and more you get to + + + align:start position:0% +seriously, the more and more you get to +this idea of like there, you know, + + align:start position:0% +this idea of like there, you know, + + + align:start position:0% +this idea of like there, you know, +there's no right way to do this. Um, + + align:start position:0% +there's no right way to do this. Um, + + + align:start position:0% +there's no right way to do this. Um, +you're all coming into this class with + + align:start position:0% +you're all coming into this class with + + + align:start position:0% +you're all coming into this class with +different goals. Maybe some of you, you + + align:start position:0% +different goals. Maybe some of you, you + + + align:start position:0% +different goals. Maybe some of you, you +know, really want to connect with other + + align:start position:0% +know, really want to connect with other + + + align:start position:0% +know, really want to connect with other +edtech companies and are interested in + + align:start position:0% +edtech companies and are interested in + + + align:start position:0% +edtech companies and are interested in +being a founder or working for a + + align:start position:0% +being a founder or working for a + + + align:start position:0% +being a founder or working for a +startup. Maybe some of you want to go + + align:start position:0% +startup. Maybe some of you want to go + + + align:start position:0% +startup. Maybe some of you want to go +into education research. Maybe some want + + align:start position:0% +into education research. Maybe some want + + + align:start position:0% +into education research. Maybe some want +to go into teaching. Why should you all + + align:start position:0% +to go into teaching. Why should you all + + + align:start position:0% +to go into teaching. Why should you all +have the same criteria for what you're + + align:start position:0% +have the same criteria for what you're + + + align:start position:0% +have the same criteria for what you're +writing about or what you're sharing? + + align:start position:0% +writing about or what you're sharing? + + + align:start position:0% +writing about or what you're sharing? +Why don't you just tell me what it is + + align:start position:0% +Why don't you just tell me what it is + + + align:start position:0% +Why don't you just tell me what it is +that you want to learn about? Why don't + + align:start position:0% +that you want to learn about? Why don't + + + align:start position:0% +that you want to learn about? Why don't +you tell me what your goals are for this + + align:start position:0% +you tell me what your goals are for this + + + align:start position:0% +you tell me what your goals are for this +kind of communication? Um and so people + + align:start position:0% +kind of communication? Um and so people + + + align:start position:0% +kind of communication? Um and so people +would create uh their own rubrics about + + align:start position:0% +would create uh their own rubrics about + + + align:start position:0% +would create uh their own rubrics about +um you know essentially like you tell me + + align:start position:0% +um you know essentially like you tell me + + + align:start position:0% +um you know essentially like you tell me +what your blog is supposed to do + + align:start position:0% +what your blog is supposed to do + + + align:start position:0% +what your blog is supposed to do +supposed to accomplish. I think at one + + align:start position:0% +supposed to accomplish. I think at one + + + align:start position:0% +supposed to accomplish. I think at one +point um you know there was a part of + + align:start position:0% +point um you know there was a part of + + + align:start position:0% +point um you know there was a part of +the assignment which you had to say like + + align:start position:0% +the assignment which you had to say like + + + align:start position:0% +the assignment which you had to say like +describe how your writing is going to + + align:start position:0% +describe how your writing is going to + + + align:start position:0% +describe how your writing is going to +benefit you and your learning, how your + + align:start position:0% +benefit you and your learning, how your + + + align:start position:0% +benefit you and your learning, how your +writing is going to benefit the other + + align:start position:0% +writing is going to benefit the other + + + align:start position:0% +writing is going to benefit the other +people in this class and how your + + align:start position:0% +people in this class and how your + + + align:start position:0% +people in this class and how your +writing might plausibly benefit some + + align:start position:0% +writing might plausibly benefit some + + + align:start position:0% +writing might plausibly benefit some +other community somewhere else that + + align:start position:0% +other community somewhere else that + + + align:start position:0% +other community somewhere else that +you're connected to in some kind of way. + + align:start position:0% +you're connected to in some kind of way. + + + align:start position:0% +you're connected to in some kind of way. +This was a professional I taught this at + + align:start position:0% +This was a professional I taught this at + + + align:start position:0% +This was a professional I taught this at +the Harvard Graduate School of + + align:start position:0% +the Harvard Graduate School of + + + align:start position:0% +the Harvard Graduate School of +Education. So people were sort of for + + align:start position:0% +Education. So people were sort of for + + + align:start position:0% +Education. So people were sort of for +the most part already coming in with + + align:start position:0% +the most part already coming in with + + + align:start position:0% +the most part already coming in with +with some kind of professional + + align:start position:0% +with some kind of professional + + + align:start position:0% +with some kind of professional +communities from outside to to network. + + align:start position:0% +communities from outside to to network. + + + align:start position:0% +communities from outside to to network. +Um and + + align:start position:0% +Um and + + + align:start position:0% +Um and +um and there were there were lots of + + align:start position:0% +um and there were there were lots of + + + align:start position:0% +um and there were there were lots of +other people um who were doing this kind + + align:start position:0% +other people um who were doing this kind + + + align:start position:0% +other people um who were doing this kind +of thing. Um this was a course called + + align:start position:0% +of thing. Um this was a course called + + + align:start position:0% +of thing. Um this was a course called +connected courses which was basically + + align:start position:0% +connected courses which was basically + + + align:start position:0% +connected courses which was basically +teaching people across higher education + + align:start position:0% +teaching people across higher education + + + align:start position:0% +teaching people across higher education +how you would go about creating these + + align:start position:0% +how you would go about creating these + + + align:start position:0% +how you would go about creating these +courses. Um, but people built them in + + align:start position:0% +courses. Um, but people built them in + + + align:start position:0% +courses. Um, but people built them in +anthropology. You know, probably one of + + align:start position:0% +anthropology. You know, probably one of + + + align:start position:0% +anthropology. You know, probably one of +the most famous ones, which I think + + align:start position:0% +the most famous ones, which I think + + + align:start position:0% +the most famous ones, which I think +still has a bunch of stuff which exists, + + align:start position:0% +still has a bunch of stuff which exists, + + + align:start position:0% +still has a bunch of stuff which exists, +um, is called DS 106, digital + + align:start position:0% +um, is called DS 106, digital + + + align:start position:0% +um, is called DS 106, digital +storytelling 106, um, which was a course + + align:start position:0% +storytelling 106, um, which was a course + + + align:start position:0% +storytelling 106, um, which was a course +offered, um, at the University of Mary + + align:start position:0% +offered, um, at the University of Mary + + + align:start position:0% +offered, um, at the University of Mary +Washington, but like essentially + + align:start position:0% +Washington, but like essentially + + + align:start position:0% +Washington, but like essentially +syndicated to a bunch of other + + align:start position:0% +syndicated to a bunch of other + + + align:start position:0% +syndicated to a bunch of other +universities and also built in such a + + align:start position:0% +universities and also built in such a + + + align:start position:0% +universities and also built in such a +way I still, you can probably still go + + align:start position:0% +way I still, you can probably still go + + + align:start position:0% +way I still, you can probably still go +to ds 106.org right now. Um, and uh, it + + align:start position:0% +to ds 106.org right now. Um, and uh, it + + + align:start position:0% +to ds 106.org right now. Um, and uh, it +was mostly about creative assignments. + + align:start position:0% +was mostly about creative assignments. + + + align:start position:0% +was mostly about creative assignments. +Um, they had a uh they had a feature + + align:start position:0% +Um, they had a uh they had a feature + + + align:start position:0% +Um, they had a uh they had a feature +called the daily create where you know + + align:start position:0% +called the daily create where you know + + + align:start position:0% +called the daily create where you know +some if you took this class four days a + + align:start position:0% +some if you took this class four days a + + + align:start position:0% +some if you took this class four days a +week, you were supposed to do a daily + + align:start position:0% +week, you were supposed to do a daily + + + align:start position:0% +week, you were supposed to do a daily +create. It might be something like my + + align:start position:0% +create. It might be something like my + + + align:start position:0% +create. It might be something like my +favorite one was uh um pull out your + + align:start position:0% +favorite one was uh um pull out your + + + align:start position:0% +favorite one was uh um pull out your +keychain and make a short video where + + align:start position:0% +keychain and make a short video where + + + align:start position:0% +keychain and make a short video where +you tell the story of your keychain. Um + + align:start position:0% +you tell the story of your keychain. Um + + + align:start position:0% +you tell the story of your keychain. Um +where does each key come from? What does + + align:start position:0% +where does each key come from? What does + + + align:start position:0% +where does each key come from? What does +it mean to you? Other kinds of things + + align:start position:0% +it mean to you? Other kinds of things + + + align:start position:0% +it mean to you? Other kinds of things +like that. Um sort of figuring out how + + align:start position:0% +like that. Um sort of figuring out how + + + align:start position:0% +like that. Um sort of figuring out how +to make their way across the web. + + align:start position:0% +to make their way across the web. + + + align:start position:0% +to make their way across the web. +Um so I told you this was a story + + align:start position:0% +Um so I told you this was a story + + + align:start position:0% +Um so I told you this was a story +essentially of a failed enterprise. Um + + align:start position:0% +essentially of a failed enterprise. Um + + + align:start position:0% +essentially of a failed enterprise. Um +you won't f like clearly I'm not + + align:start position:0% +you won't f like clearly I'm not + + + align:start position:0% +you won't f like clearly I'm not +teaching like this anymore. Um you won't + + align:start position:0% +teaching like this anymore. Um you won't + + + align:start position:0% +teaching like this anymore. Um you won't +find many other classes. You'll find + + align:start position:0% +find many other classes. You'll find + + + align:start position:0% +find many other classes. You'll find +you'll find you know the ideas kind of + + align:start position:0% +you'll find you know the ideas kind of + + + align:start position:0% +you'll find you know the ideas kind of +out there percolating in different + + align:start position:0% +out there percolating in different + + + align:start position:0% +out there percolating in different +spaces. Um uh but like probably doesn't + + align:start position:0% +spaces. Um uh but like probably doesn't + + + align:start position:0% +spaces. Um uh but like probably doesn't +really exist. Um why did it fail? + + align:start position:0% +really exist. Um why did it fail? + + + align:start position:0% +really exist. Um why did it fail? +Probably two big reasons. Um one that + + align:start position:0% +Probably two big reasons. Um one that + + + align:start position:0% +Probably two big reasons. Um one that +we'll keep coming back to which I've + + align:start position:0% +we'll keep coming back to which I've + + + align:start position:0% +we'll keep coming back to which I've +termed the curse of the familiar which + + align:start position:0% +termed the curse of the familiar which + + + align:start position:0% +termed the curse of the familiar which +is it's just weird. Um, it's different. + + align:start position:0% +is it's just weird. Um, it's different. + + + align:start position:0% +is it's just weird. Um, it's different. +It's unusual. It takes a bunch of time + + align:start position:0% +It's unusual. It takes a bunch of time + + + align:start position:0% +It's unusual. It takes a bunch of time +to learn. On the one hand, I think + + align:start position:0% +to learn. On the one hand, I think + + + align:start position:0% +to learn. On the one hand, I think +people who are participating in these + + align:start position:0% +people who are participating in these + + + align:start position:0% +people who are participating in these +classes were like, "Ah man, I learned a + + align:start position:0% +classes were like, "Ah man, I learned a + + + align:start position:0% +classes were like, "Ah man, I learned a +lot of stuff about blogging, about using + + align:start position:0% +lot of stuff about blogging, about using + + + align:start position:0% +lot of stuff about blogging, about using +Twitter, about connecting with other + + align:start position:0% +Twitter, about connecting with other + + + align:start position:0% +Twitter, about connecting with other +people, about social networking." But + + align:start position:0% +people, about social networking." But + + + align:start position:0% +people, about social networking." But +like, you know, my guy the, you know, + + align:start position:0% +like, you know, my guy the, you know, + + + align:start position:0% +like, you know, my guy the, you know, +the the class was intermediate + + align:start position:0% +the the class was intermediate + + + align:start position:0% +the the class was intermediate +statistics. Like like that's not what + + align:start position:0% +statistics. Like like that's not what + + + align:start position:0% +statistics. Like like that's not what +you were supposed to be learning in this + + align:start position:0% +you were supposed to be learning in this + + + align:start position:0% +you were supposed to be learning in this +thing. Um there were a handful of + + align:start position:0% +thing. Um there were a handful of + + + align:start position:0% +thing. Um there were a handful of +universities that built a sort of + + align:start position:0% +universities that built a sort of + + + align:start position:0% +universities that built a sort of +collaborative infrastructure around this + + align:start position:0% +collaborative infrastructure around this + + + align:start position:0% +collaborative infrastructure around this +stuff in the hopes that you could drive + + align:start position:0% +stuff in the hopes that you could drive + + + align:start position:0% +stuff in the hopes that you could drive +down some of the complexity. So this guy + + align:start position:0% +down some of the complexity. So this guy + + + align:start position:0% +down some of the complexity. So this guy +Jim Groom built a company called Reclaim + + align:start position:0% +Jim Groom built a company called Reclaim + + + align:start position:0% +Jim Groom built a company called Reclaim +Hosting um which tried to make it really + + align:start position:0% +Hosting um which tried to make it really + + + align:start position:0% +Hosting um which tried to make it really +like universities could sign up to make + + align:start position:0% +like universities could sign up to make + + + align:start position:0% +like universities could sign up to make +it really easy for every student in the + + align:start position:0% +it really easy for every student in the + + + align:start position:0% +it really easy for every student in the +school to start a blog and then you like + + align:start position:0% +school to start a blog and then you like + + + align:start position:0% +school to start a blog and then you like +teach them all about blogging a little + + align:start position:0% +teach them all about blogging a little + + + align:start position:0% +teach them all about blogging a little +bit and then maybe you could get away + + align:start position:0% +bit and then maybe you could get away + + + align:start position:0% +bit and then maybe you could get away +from discussion forums and have people + + align:start position:0% +from discussion forums and have people + + + align:start position:0% +from discussion forums and have people +do more so of their short form writing + + align:start position:0% +do more so of their short form writing + + + align:start position:0% +do more so of their short form writing +on blogs. Um maybe there are some people + + align:start position:0% +on blogs. Um maybe there are some people + + + align:start position:0% +on blogs. Um maybe there are some people +out there that are still trying it but + + align:start position:0% +out there that are still trying it but + + + align:start position:0% +out there that are still trying it but +uh but not that much. Um and then + + align:start position:0% +uh but not that much. Um and then + + + align:start position:0% +uh but not that much. Um and then +um uh another huge challenge with asking + + align:start position:0% +um uh another huge challenge with asking + + + align:start position:0% +um uh another huge challenge with asking +people to write publicly uh is that we + + align:start position:0% +people to write publicly uh is that we + + + align:start position:0% +people to write publicly uh is that we +are not all equally vulnerable to the + + align:start position:0% +are not all equally vulnerable to the + + + align:start position:0% +are not all equally vulnerable to the +consequences of um having our writing be + + align:start position:0% +consequences of um having our writing be + + + align:start position:0% +consequences of um having our writing be +read. Anybody recognize this person? Um + + align:start position:0% +read. Anybody recognize this person? Um + + + align:start position:0% +read. Anybody recognize this person? Um +she's a woman named uh Anita Sarassian + + align:start position:0% +she's a woman named uh Anita Sarassian + + + align:start position:0% +she's a woman named uh Anita Sarassian +um who uh um had a website called + + align:start position:0% +um who uh um had a website called + + + align:start position:0% +um who uh um had a website called +Feminist Frequency which uh um was sort + + align:start position:0% +Feminist Frequency which uh um was sort + + + align:start position:0% +Feminist Frequency which uh um was sort +of one of one of the initial spaces that + + align:start position:0% +of one of one of the initial spaces that + + + align:start position:0% +of one of one of the initial spaces that +was related to um what became Gamergate. + + align:start position:0% +was related to um what became Gamergate. + + + align:start position:0% +was related to um what became Gamergate. +Um she uh she made a bunch of videos + + align:start position:0% +Um she uh she made a bunch of videos + + + align:start position:0% +Um she uh she made a bunch of videos +basically about sort of anti-feminist + + align:start position:0% +basically about sort of anti-feminist + + + align:start position:0% +basically about sort of anti-feminist +themes in video games like how uh um how + + align:start position:0% +themes in video games like how uh um how + + + align:start position:0% +themes in video games like how uh um how +like you know there's always a princess + + align:start position:0% +like you know there's always a princess + + + align:start position:0% +like you know there's always a princess +that needs to be saved and the princess + + align:start position:0% +that needs to be saved and the princess + + + align:start position:0% +that needs to be saved and the princess +doesn't actually have to like doesn't + + align:start position:0% +doesn't actually have to like doesn't + + + align:start position:0% +doesn't actually have to like doesn't +get to have her own character and things + + align:start position:0% +get to have her own character and things + + + align:start position:0% +get to have her own character and things +like that. Um and uh just you know piled + + align:start position:0% +like that. Um and uh just you know piled + + + align:start position:0% +like that. Um and uh just you know piled +on ruthlessly um by by all kinds of + + align:start position:0% +on ruthlessly um by by all kinds of + + + align:start position:0% +on ruthlessly um by by all kinds of +people you know especially people who + + align:start position:0% +people you know especially people who + + + align:start position:0% +people you know especially people who +who saw gaming as a hobby who didn't + + align:start position:0% +who saw gaming as a hobby who didn't + + + align:start position:0% +who saw gaming as a hobby who didn't +want these tropes changed. Um, and so + + align:start position:0% +want these tropes changed. Um, and so + + + align:start position:0% +want these tropes changed. Um, and so +you know, people get doxed and swatted + + align:start position:0% +you know, people get doxed and swatted + + + align:start position:0% +you know, people get doxed and swatted +and all kinds of Are you all familiar + + align:start position:0% +and all kinds of Are you all familiar + + + align:start position:0% +and all kinds of Are you all familiar +with Gamergate? Is that a phrase? Okay. + + align:start position:0% +with Gamergate? Is that a phrase? Okay. + + + align:start position:0% +with Gamergate? Is that a phrase? Okay. +Um, so I don't even remember what year + + align:start position:0% +Um, so I don't even remember what year + + + align:start position:0% +Um, so I don't even remember what year +this was now, but uh um I don't know. We + + align:start position:0% +this was now, but uh um I don't know. We + + + align:start position:0% +this was now, but uh um I don't know. We +should in the media studies department, + + align:start position:0% +should in the media studies department, + + + align:start position:0% +should in the media studies department, +we should be teaching a class called + + align:start position:0% +we should be teaching a class called + + + align:start position:0% +we should be teaching a class called +Gamergate. It was it was kind of um it + + align:start position:0% +Gamergate. It was it was kind of um it + + + align:start position:0% +Gamergate. It was it was kind of um it +seemed ludicrous at the time, but it was + + align:start position:0% +seemed ludicrous at the time, but it was + + + align:start position:0% +seemed ludicrous at the time, but it was +uh it was a sort of way of you know + + align:start position:0% +uh it was a sort of way of you know + + + align:start position:0% +uh it was a sort of way of you know +organizing groups of people to + + align:start position:0% +organizing groups of people to + + + align:start position:0% +organizing groups of people to +effectively suppress communication from + + align:start position:0% +effectively suppress communication from + + + align:start position:0% +effectively suppress communication from +sort of subalter perspectives from + + align:start position:0% +sort of subalter perspectives from + + + align:start position:0% +sort of subalter perspectives from +people who are trying to say different + + align:start position:0% +people who are trying to say different + + + align:start position:0% +people who are trying to say different +kinds of things. Um, so yeah, anyway, + + align:start position:0% +kinds of things. Um, so yeah, anyway, + + + align:start position:0% +kinds of things. Um, so yeah, anyway, +for me as like a pretty privileged white + + align:start position:0% +for me as like a pretty privileged white + + + align:start position:0% +for me as like a pretty privileged white +dude like blogging my way through the + + align:start position:0% +dude like blogging my way through the + + + align:start position:0% +dude like blogging my way through the +world is relatively safe and relatively + + align:start position:0% +world is relatively safe and relatively + + + align:start position:0% +world is relatively safe and relatively +straightforward, but you know, if I have + + align:start position:0% +straightforward, but you know, if I have + + + align:start position:0% +straightforward, but you know, if I have +50 or 60 students in my class, they're + + align:start position:0% +50 or 60 students in my class, they're + + + align:start position:0% +50 or 60 students in my class, they're +all going to be coming from different + + align:start position:0% +all going to be coming from different + + + align:start position:0% +all going to be coming from different +perspectives and they're all going to be + + align:start position:0% +perspectives and they're all going to be + + + align:start position:0% +perspectives and they're all going to be +sort of inequitably vulnerable um to + + align:start position:0% +sort of inequitably vulnerable um to + + + align:start position:0% +sort of inequitably vulnerable um to +writing something which catches the + + align:start position:0% +writing something which catches the + + + align:start position:0% +writing something which catches the +attention in negative ways of big crowds + + align:start position:0% +attention in negative ways of big crowds + + + align:start position:0% +attention in negative ways of big crowds +um or offends people or messes up their + + align:start position:0% +um or offends people or messes up their + + + align:start position:0% +um or offends people or messes up their +relationship or other kinds of things. I + + align:start position:0% +relationship or other kinds of things. I + + + align:start position:0% +relationship or other kinds of things. I +mean, what part of what you want to do + + align:start position:0% +mean, what part of what you want to do + + + align:start position:0% +mean, what part of what you want to do +in writing in a class is let people be + + align:start position:0% +in writing in a class is let people be + + + align:start position:0% +in writing in a class is let people be +experimental and try on ideas that they + + align:start position:0% +experimental and try on ideas that they + + + align:start position:0% +experimental and try on ideas that they +don't agree with yet or don't understand + + align:start position:0% + + + + align:start position:0% + +yet, you know, and in when I was doing + + align:start position:0% +yet, you know, and in when I was doing + + + align:start position:0% +yet, you know, and in when I was doing +this in 2013, that felt like a little + + align:start position:0% +this in 2013, that felt like a little + + + align:start position:0% +this in 2013, that felt like a little +bit risky, maybe like yeah, I could I + + align:start position:0% +bit risky, maybe like yeah, I could I + + + align:start position:0% +bit risky, maybe like yeah, I could I +could imagine someone might like take + + align:start position:0% +could imagine someone might like take + + + align:start position:0% +could imagine someone might like take +down a post that they, you know, decide + + align:start position:0% +down a post that they, you know, decide + + + align:start position:0% +down a post that they, you know, decide +wasn't well worded or disagree with + + align:start position:0% +wasn't well worded or disagree with + + + align:start position:0% +wasn't well worded or disagree with +things like that. Um, in 2024, it seems + + align:start position:0% +things like that. Um, in 2024, it seems + + + align:start position:0% +things like that. Um, in 2024, it seems +substantially um more risky. Not not I + + align:start position:0% +substantially um more risky. Not not I + + + align:start position:0% +substantially um more risky. Not not I +would say not just because um of + + align:start position:0% +would say not just because um of + + + align:start position:0% +would say not just because um of +heightened sensitivities um but because + + align:start position:0% +heightened sensitivities um but because + + + align:start position:0% +heightened sensitivities um but because +you know because actors in society have + + align:start position:0% +you know because actors in society have + + + align:start position:0% +you know because actors in society have +learned how to + + align:start position:0% +learned how to + + + align:start position:0% +learned how to +um how to how to broadcast messages that + + align:start position:0% +um how to how to broadcast messages that + + + align:start position:0% +um how to how to broadcast messages that +appear online in various kinds of places + + align:start position:0% +appear online in various kinds of places + + + align:start position:0% +appear online in various kinds of places +um and to use them to generate outrage + + align:start position:0% +um and to use them to generate outrage + + + align:start position:0% +um and to use them to generate outrage +and drive traffic and and those kinds of + + align:start position:0% +and drive traffic and and those kinds of + + + align:start position:0% +and drive traffic and and those kinds of +things. + + align:start position:0% +things. + + + align:start position:0% +things. +Um, oh, this was the company, uh, + + align:start position:0% +Um, oh, this was the company, uh, + + + align:start position:0% +Um, oh, this was the company, uh, +Reclaim Hosting. Um, and they're, uh, + + align:start position:0% +Reclaim Hosting. Um, and they're, uh, + + + align:start position:0% +Reclaim Hosting. Um, and they're, uh, +somebody should Google Reclaim Hosting + + align:start position:0% +somebody should Google Reclaim Hosting + + + align:start position:0% +somebody should Google Reclaim Hosting +and see if they're they're still, um, + + align:start position:0% +and see if they're they're still, um, + + + align:start position:0% +and see if they're they're still, um, +uh, known for education was a was a + + align:start position:0% +uh, known for education was a was a + + + align:start position:0% +uh, known for education was a was a +project that was basically it was sort + + align:start position:0% +project that was basically it was sort + + + align:start position:0% +project that was basically it was sort +of trying to take like everything that I + + align:start position:0% +of trying to take like everything that I + + + align:start position:0% +of trying to take like everything that I +just described and figure out like how + + align:start position:0% +just described and figure out like how + + + align:start position:0% +just described and figure out like how +do you make a really simple front end + + align:start position:0% +do you make a really simple front end + + + align:start position:0% +do you make a really simple front end +for it so it's not hard for people to + + align:start position:0% +for it so it's not hard for people to + + + align:start position:0% +for it so it's not hard for people to +build, but it still lets people own + + align:start position:0% +build, but it still lets people own + + + align:start position:0% +build, but it still lets people own +stuff. um it still lets people sort of + + align:start position:0% +stuff. um it still lets people sort of + + + align:start position:0% +stuff. um it still lets people sort of +you know be the be the owner of their + + align:start position:0% +you know be the be the owner of their + + + align:start position:0% +you know be the be the owner of their +own means of production. + + align:start position:0% +own means of production. + + + align:start position:0% +own means of production. +Um but it's something that I think will + + align:start position:0% +Um but it's something that I think will + + + align:start position:0% +Um but it's something that I think will +um this was you know by far the most + + align:start position:0% +um this was you know by far the most + + + align:start position:0% +um this was you know by far the most +exciting part of teaching these courses + + align:start position:0% +exciting part of teaching these courses + + + align:start position:0% +exciting part of teaching these courses +was realizing that people were still + + align:start position:0% +was realizing that people were still + + + align:start position:0% +was realizing that people were still +using this infrastructure in various + + align:start position:0% +using this infrastructure in various + + + align:start position:0% +using this infrastructure in various +kinds of ways years after the course + + align:start position:0% +kinds of ways years after the course + + + align:start position:0% +kinds of ways years after the course +ended. So I think I taught this course + + align:start position:0% +ended. So I think I taught this course + + + align:start position:0% +ended. So I think I taught this course +in 2013 and still in 2015 people were + + align:start position:0% +in 2013 and still in 2015 people were + + + align:start position:0% +in 2013 and still in 2015 people were +posting on their blogs connecting with + + align:start position:0% +posting on their blogs connecting with + + + align:start position:0% +posting on their blogs connecting with +each other like you know I don't know + + align:start position:0% +each other like you know I don't know + + + align:start position:0% +each other like you know I don't know +the equivalent of that would be like you + + align:start position:0% +the equivalent of that would be like you + + + align:start position:0% +the equivalent of that would be like you +know if you're in 1806 now and it has a + + align:start position:0% +know if you're in 1806 now and it has a + + + align:start position:0% +know if you're in 1806 now and it has a +piaza forum what if three years from now + + align:start position:0% +piaza forum what if three years from now + + + align:start position:0% +piaza forum what if three years from now +you were inspired to like hop back in + + align:start position:0% +you were inspired to like hop back in + + + align:start position:0% +you were inspired to like hop back in +there and + + align:start position:0% +there and + + + align:start position:0% +there and +still like good god I would never do + + align:start position:0% +still like good god I would never do + + + align:start position:0% +still like good god I would never do +such a thing but part you know you + + align:start position:0% +such a thing but part you know you + + + align:start position:0% +such a thing but part you know you +wouldn't do such a thing because you + + align:start position:0% +wouldn't do such a thing because you + + + align:start position:0% +wouldn't do such a thing because you +don't own it and it's not yours and you + + align:start position:0% +don't own it and it's not yours and you + + + align:start position:0% +don't own it and it's not yours and you +can't take it in the direction that + + align:start position:0% +can't take it in the direction that + + + align:start position:0% +can't take it in the direction that +you're interested in. But if we, you + + align:start position:0% +you're interested in. But if we, you + + + align:start position:0% +you're interested in. But if we, you +know, in higher education, if we gave + + align:start position:0% +know, in higher education, if we gave + + + align:start position:0% +know, in higher education, if we gave +you an infrastructure that you had some + + align:start position:0% +you an infrastructure that you had some + + + align:start position:0% +you an infrastructure that you had some +control over, um, you might be + + align:start position:0% +control over, um, you might be + + + align:start position:0% +control over, um, you might be +substantially more, I mean, at least the + + align:start position:0% +substantially more, I mean, at least the + + + align:start position:0% +substantially more, I mean, at least the +students at the time were, um, were were + + align:start position:0% +students at the time were, um, were were + + + align:start position:0% +students at the time were, um, were were +interested in in continuing to pursue + + align:start position:0% +interested in in continuing to pursue + + + align:start position:0% +interested in in continuing to pursue +these kinds of, uh, these kinds of + + align:start position:0% +these kinds of, uh, these kinds of + + + align:start position:0% +these kinds of, uh, these kinds of +learning experiences. + + align:start position:0% +learning experiences. + + + align:start position:0% +learning experiences. +Um but I would but I would say the sort + + align:start position:0% +Um but I would but I would say the sort + + + align:start position:0% +Um but I would but I would say the sort +of the the the degree to which people + + align:start position:0% +of the the the degree to which people + + + align:start position:0% +of the the the degree to which people +feel much more individual threat about + + align:start position:0% +feel much more individual threat about + + + align:start position:0% +feel much more individual threat about +sharing things um online especially in + + align:start position:0% +sharing things um online especially in + + + align:start position:0% +sharing things um online especially in +really sort of open spaces. Um and just + + align:start position:0% +really sort of open spaces. Um and just + + + align:start position:0% +really sort of open spaces. Um and just +the like difficulty of the ramp up time + + align:start position:0% +the like difficulty of the ramp up time + + + align:start position:0% +the like difficulty of the ramp up time +of building all this infrastructure has + + align:start position:0% +of building all this infrastructure has + + + align:start position:0% +of building all this infrastructure has +made it like more or less um an + + align:start position:0% +made it like more or less um an + + + align:start position:0% +made it like more or less um an +interesting dead end and something kind + + align:start position:0% +interesting dead end and something kind + + + align:start position:0% +interesting dead end and something kind +of fun to learn from and explore. It + + align:start position:0% +of fun to learn from and explore. It + + + align:start position:0% +of fun to learn from and explore. It +probably also illustrates um more of + + align:start position:0% +probably also illustrates um more of + + + align:start position:0% +probably also illustrates um more of +what you'll read about. This is like an + + align:start position:0% +what you'll read about. This is like an + + + align:start position:0% +what you'll read about. This is like an +effort in higher education that + + align:start position:0% +effort in higher education that + + + align:start position:0% +effort in higher education that +basically foundered. Um you'll read + + align:start position:0% +basically foundered. Um you'll read + + + align:start position:0% +basically foundered. Um you'll read +about other kinds of things that sort of + + align:start position:0% +about other kinds of things that sort of + + + align:start position:0% +about other kinds of things that sort of +foundered in different ways in K12 or + + align:start position:0% +foundered in different ways in K12 or + + + align:start position:0% +foundered in different ways in K12 or +the challenge to make them not founder + + align:start position:0% +the challenge to make them not founder + + + align:start position:0% +the challenge to make them not founder +for next week. Like there's all this + + align:start position:0% +for next week. Like there's all this + + + align:start position:0% +for next week. Like there's all this +amazing learning that happens um in + + align:start position:0% +amazing learning that happens um in + + + align:start position:0% +amazing learning that happens um in +people's informal learning experiences. + + align:start position:0% +people's informal learning experiences. + + + align:start position:0% +people's informal learning experiences. +How do we why is it so hard to bring + + align:start position:0% +How do we why is it so hard to bring + + + align:start position:0% +How do we why is it so hard to bring +those practices into school + + align:start position:0% +those practices into school + + + align:start position:0% +those practices into school +environments? What is the nature of + + align:start position:0% +environments? What is the nature of + + + align:start position:0% +environments? What is the nature of +school environments um that makes it + + align:start position:0% +school environments um that makes it + + + align:start position:0% +school environments um that makes it +difficult for that to happen? + + align:start position:0% +difficult for that to happen? + + + align:start position:0% +difficult for that to happen? +Um good. What qu maybe I think that's + + align:start position:0% +Um good. What qu maybe I think that's + + + align:start position:0% +Um good. What qu maybe I think that's +where I got to the end. what questions + + align:start position:0% +where I got to the end. what questions + + + align:start position:0% +where I got to the end. what questions +do folks have or what um um my question + + align:start position:0% +do folks have or what um um my question + + + align:start position:0% +do folks have or what um um my question +is um what place kind of does um like + + align:start position:0% +is um what place kind of does um like + + + align:start position:0% +is um what place kind of does um like +kind of online community building + + align:start position:0% +kind of online community building + + + align:start position:0% +kind of online community building +without the presence of like instructors + + align:start position:0% +without the presence of like instructors + + + align:start position:0% +without the presence of like instructors +have in this + + align:start position:0% +have in this + + + align:start position:0% +have in this +yeah if it was if if this worked + + align:start position:0% +yeah if it was if if this worked + + + align:start position:0% +yeah if it was if if this worked +um because you owned your own piece of + + align:start position:0% +um because you owned your own piece of + + + align:start position:0% +um because you owned your own piece of +writing you know I'm teaching this class + + align:start position:0% +writing you know I'm teaching this class + + + align:start position:0% +writing you know I'm teaching this class +at a professional school um you might + + align:start position:0% +at a professional school um you might + + + align:start position:0% +at a professional school um you might +find that actually what motivates you + + align:start position:0% +find that actually what motivates you + + + align:start position:0% +find that actually what motivates you +most to write these assignments is that + + align:start position:0% +most to write these assignments is that + + + align:start position:0% +most to write these assignments is that +you've found a bunch of other sixth + + align:start position:0% +you've found a bunch of other sixth + + + align:start position:0% +you've found a bunch of other sixth +grade science teachers that are reading + + align:start position:0% +grade science teachers that are reading + + + align:start position:0% +grade science teachers that are reading +your blog posts and you sort of + + align:start position:0% +your blog posts and you sort of + + + align:start position:0% +your blog posts and you sort of +increasingly care less that you know + + align:start position:0% +increasingly care less that you know + + + align:start position:0% +increasingly care less that you know +Justin the instructor of this class is + + align:start position:0% +Justin the instructor of this class is + + + align:start position:0% +Justin the instructor of this class is +reading your stuff and more like hey I'm + + align:start position:0% +reading your stuff and more like hey I'm + + + align:start position:0% +reading your stuff and more like hey I'm +getting my ideas out there and + + align:start position:0% +getting my ideas out there and + + + align:start position:0% +getting my ideas out there and +connecting more with other earth science + + align:start position:0% +connecting more with other earth science + + + align:start position:0% +connecting more with other earth science +teachers. Um and that I think for a lot + + align:start position:0% +teachers. Um and that I think for a lot + + + align:start position:0% +teachers. Um and that I think for a lot +of you know when it was most successful + + align:start position:0% +of you know when it was most successful + + + align:start position:0% +of you know when it was most successful +that for people just felt like work that + + align:start position:0% +that for people just felt like work that + + + align:start position:0% +that for people just felt like work that +was super real and urgent. Um you know + + align:start position:0% +was super real and urgent. Um you know + + + align:start position:0% +was super real and urgent. Um you know +the the other thing is most of the thing + + align:start position:0% +the the other thing is most of the thing + + + align:start position:0% +the the other thing is most of the thing +I don't know um when people got + + align:start position:0% +I don't know um when people got + + + align:start position:0% +I don't know um when people got +responses it it there there wasn't a + + align:start position:0% +responses it it there there wasn't a + + + align:start position:0% +responses it it there there wasn't a +whole lot of there's probably some but + + align:start position:0% +whole lot of there's probably some but + + + align:start position:0% +whole lot of there's probably some but +there wasn't a whole lot of like you are + + align:start position:0% +there wasn't a whole lot of like you are + + + align:start position:0% +there wasn't a whole lot of like you are +required to reply to at least two people + + align:start position:0% +required to reply to at least two people + + + align:start position:0% +required to reply to at least two people +um kinds of things. Um there was a lot + + align:start position:0% +um kinds of things. Um there was a lot + + + align:start position:0% +um kinds of things. Um there was a lot +of you know when like people would write + + align:start position:0% +of you know when like people would write + + + align:start position:0% +of you know when like people would write +blog posts but they would write blog + + align:start position:0% +blog posts but they would write blog + + + align:start position:0% +blog posts but they would write blog +posts that sort of tagged or or posted + + align:start position:0% +posts that sort of tagged or or posted + + + align:start position:0% +posts that sort of tagged or or posted +back to someone else's post. So it was + + align:start position:0% +back to someone else's post. So it was + + + align:start position:0% +back to someone else's post. So it was +just kind of like a natural um uh + + align:start position:0% +just kind of like a natural um uh + + + align:start position:0% +just kind of like a natural um uh +conversation that was that was happening + + align:start position:0% +conversation that was that was happening + + + align:start position:0% +conversation that was that was happening +and unfolding like where it was most + + align:start position:0% +and unfolding like where it was most + + + align:start position:0% +and unfolding like where it was most +successful + + align:start position:0% +successful + + + align:start position:0% +successful +um what you felt like as an instructor + + align:start position:0% +um what you felt like as an instructor + + + align:start position:0% +um what you felt like as an instructor +is you were you were just like put + + align:start position:0% +is you were you were just like put + + + align:start position:0% +is you were you were just like put +putting putting some fuel for this fire + + align:start position:0% +putting putting some fuel for this fire + + + align:start position:0% +putting putting some fuel for this fire +to burn on its own. you were just like, + + align:start position:0% +to burn on its own. you were just like, + + + align:start position:0% +to burn on its own. you were just like, +you know, here check out these things + + align:start position:0% +you know, here check out these things + + + align:start position:0% +you know, here check out these things +like, you know, and then but then people + + align:start position:0% +like, you know, and then but then people + + + align:start position:0% +like, you know, and then but then people +would take them in the directions that + + align:start position:0% +would take them in the directions that + + + align:start position:0% +would take them in the directions that +they were most interested and excited + + align:start position:0% +they were most interested and excited + + + align:start position:0% +they were most interested and excited +about. Does that answer your + + align:start position:0% + + + + align:start position:0% + +question other thoughts or things that + + align:start position:0% +question other thoughts or things that + + + align:start position:0% +question other thoughts or things that +how does this play into the Google doc + + align:start position:0% +how does this play into the Google doc + + + align:start position:0% +how does this play into the Google doc +that runs this course? Huh? Yeah. So, + + align:start position:0% +that runs this course? Huh? Yeah. So, + + + align:start position:0% +that runs this course? Huh? Yeah. So, +well, some of it is I uh probably + + align:start position:0% +well, some of it is I uh probably + + + align:start position:0% +well, some of it is I uh probably +probably the main lingering piece um is + + align:start position:0% +probably the main lingering piece um is + + + align:start position:0% +probably the main lingering piece um is +that it's a is that it's a pain in the + + align:start position:0% +that it's a is that it's a pain in the + + + align:start position:0% +that it's a is that it's a pain in the +ass to show my Canvas site to someone + + align:start position:0% +ass to show my Canvas site to someone + + + align:start position:0% +ass to show my Canvas site to someone +else. And one of the main things that I + + align:start position:0% +else. And one of the main things that I + + + align:start position:0% +else. And one of the main things that I +want to do is, you know, I don't know, + + align:start position:0% +want to do is, you know, I don't know, + + + align:start position:0% +want to do is, you know, I don't know, +in in in my career of teaching is be + + align:start position:0% +in in in my career of teaching is be + + + align:start position:0% +in in in my career of teaching is be +able to like quickly to explain to other + + align:start position:0% +able to like quickly to explain to other + + + align:start position:0% +able to like quickly to explain to other +people how I teach. Um, so one, you + + align:start position:0% +people how I teach. Um, so one, you + + + align:start position:0% +people how I teach. Um, so one, you +know, one of the best things about + + align:start position:0% +know, one of the best things about + + + align:start position:0% +know, one of the best things about +having the whole course live on a Google + + align:start position:0% +having the whole course live on a Google + + + align:start position:0% +having the whole course live on a Google +doc is, you know, any new professor + + align:start position:0% +doc is, you know, any new professor + + + align:start position:0% +doc is, you know, any new professor +who's just starting teaching edtech and + + align:start position:0% +who's just starting teaching edtech and + + + align:start position:0% +who's just starting teaching edtech and +society, it's like here's a whole + + align:start position:0% +society, it's like here's a whole + + + align:start position:0% +society, it's like here's a whole +course, you know, take it and c I mean, + + align:start position:0% +course, you know, take it and c I mean, + + + align:start position:0% +course, you know, take it and c I mean, +they're probably taking it and like + + align:start position:0% +they're probably taking it and like + + + align:start position:0% +they're probably taking it and like +shoving it bit by bit into Canvas, which + + align:start position:0% +shoving it bit by bit into Canvas, which + + + align:start position:0% +shoving it bit by bit into Canvas, which +I've done periodically for some things. + + align:start position:0% +I've done periodically for some things. + + + align:start position:0% +I've done periodically for some things. +Um, that any of you, you know, who want + + align:start position:0% +Um, that any of you, you know, who want + + + align:start position:0% +Um, that any of you, you know, who want +to sign up for my, you know, future + + align:start position:0% +to sign up for my, you know, future + + + align:start position:0% +to sign up for my, you know, future +people who are interested in this class, + + align:start position:0% +people who are interested in this class, + + + align:start position:0% +people who are interested in this class, +you know, syllabus is there. You, you + + align:start position:0% +you know, syllabus is there. You, you + + + align:start position:0% +you know, syllabus is there. You, you +know, I mean, it's even got it's even + + align:start position:0% +know, I mean, it's even got it's even + + + align:start position:0% +know, I mean, it's even got it's even +got the revision history. You can now + + align:start position:0% +got the revision history. You can now + + + align:start position:0% +got the revision history. You can now +see, nobody does that, but you can now + + align:start position:0% +see, nobody does that, but you can now + + + align:start position:0% +see, nobody does that, but you can now +see what we did. I mean in I I would + + align:start position:0% +see what we did. I mean in I I would + + + align:start position:0% +see what we did. I mean in I I would +also say earlier versions of that like + + align:start position:0% +also say earlier versions of that like + + + align:start position:0% +also say earlier versions of that like +when the web was sort of more active in + + align:start position:0% +when the web was sort of more active in + + + align:start position:0% +when the web was sort of more active in +this way, you know, I would like over + + align:start position:0% +this way, you know, I would like over + + + align:start position:0% +this way, you know, I would like over +the summer I would post like here are + + align:start position:0% +the summer I would post like here are + + + align:start position:0% +the summer I would post like here are +all the changes that I made to my + + align:start position:0% +all the changes that I made to my + + + align:start position:0% +all the changes that I made to my +syllabus and like circulated around to + + align:start position:0% +syllabus and like circulated around to + + + align:start position:0% +syllabus and like circulated around to +hashtags or other networks of people + + align:start position:0% +hashtags or other networks of people + + + align:start position:0% +hashtags or other networks of people +that were active in those conversations + + align:start position:0% +that were active in those conversations + + + align:start position:0% +that were active in those conversations +and people would definitely jump in to + + align:start position:0% +and people would definitely jump in to + + + align:start position:0% +and people would definitely jump in to +the syllabus um and through and add + + align:start position:0% +the syllabus um and through and add + + + align:start position:0% +the syllabus um and through and add +comments and be like oh you this new + + align:start position:0% +comments and be like oh you this new + + + align:start position:0% +comments and be like oh you this new +book just came out or these new + + align:start position:0% +book just came out or these new + + + align:start position:0% +book just came out or these new +resources came out and things like that. + + align:start position:0% +resources came out and things like that. + + + align:start position:0% +resources came out and things like that. +I mean it existed as a for for a period + + align:start position:0% +I mean it existed as a for for a period + + + align:start position:0% +I mean it existed as a for for a period +of time a much more sort of social + + align:start position:0% +of time a much more sort of social + + + align:start position:0% +of time a much more sort of social +document. Um again when when yeah there + + align:start position:0% +document. Um again when when yeah there + + + align:start position:0% +document. Um again when when yeah there +were a lot of you know educators + + align:start position:0% +were a lot of you know educators + + + align:start position:0% +were a lot of you know educators +especially people interested in online + + align:start position:0% +especially people interested in online + + + align:start position:0% +especially people interested in online +learning and education technology who + + align:start position:0% +learning and education technology who + + + align:start position:0% +learning and education technology who +were pretty active in those kinds of + + align:start position:0% +were pretty active in those kinds of + + + align:start position:0% +were pretty active in those kinds of +communities. Um and so you could do + + align:start position:0% +communities. Um and so you could do + + + align:start position:0% +communities. Um and so you could do +stuff like that. Now it's mostly just a + + align:start position:0% +stuff like that. Now it's mostly just a + + + align:start position:0% +stuff like that. Now it's mostly just a +legacy of you know editing that thing is + + align:start position:0% +legacy of you know editing that thing is + + + align:start position:0% +legacy of you know editing that thing is +so much easier than editing canvas. Um + + align:start position:0% +so much easier than editing canvas. Um + + + align:start position:0% +so much easier than editing canvas. Um +anytime I want to change something in + + align:start position:0% +anytime I want to change something in + + + align:start position:0% +anytime I want to change something in +canvas I have to do it in three places + + align:start position:0% +canvas I have to do it in three places + + + align:start position:0% +canvas I have to do it in three places +and click 15 buttons like Google doc I + + align:start position:0% +and click 15 buttons like Google doc I + + + align:start position:0% +and click 15 buttons like Google doc I +just edit. Um good. So that was a little + + align:start position:0% +just edit. Um good. So that was a little + + + align:start position:0% +just edit. Um good. So that was a little +bit in uh some of these ideas of peer + + align:start position:0% +bit in uh some of these ideas of peer + + + align:start position:0% +bit in uh some of these ideas of peer +guided learning in higher education. + + align:start position:0% +guided learning in higher education. + + + align:start position:0% +guided learning in higher education. +We'll see some more of them. Um, in K12, + + align:start position:0% +We'll see some more of them. Um, in K12, + + + align:start position:0% +We'll see some more of them. Um, in K12, +I think you're going to read some stuff + + align:start position:0% +I think you're going to read some stuff + + + align:start position:0% +I think you're going to read some stuff +from Mimito and uh + + align:start position:0% +from Mimito and uh + + + align:start position:0% +from Mimito and uh +um what else did I make you do for next + + align:start position:0% +um what else did I make you do for next + + + align:start position:0% +um what else did I make you do for next +time? And and Mitch Resnik um about + + align:start position:0% +time? And and Mitch Resnik um about + + + align:start position:0% +time? And and Mitch Resnik um about +Scratch, which is Scratch is probably + + align:start position:0% +Scratch, which is Scratch is probably + + + align:start position:0% +Scratch, which is Scratch is probably +the um most successful peer-guided + + align:start position:0% +the um most successful peer-guided + + + align:start position:0% +the um most successful peer-guided +learning environment which has made its + + align:start position:0% +learning environment which has made its + + + align:start position:0% +learning environment which has made its +way into K12 schools. Although one of + + align:start position:0% +way into K12 schools. Although one of + + + align:start position:0% +way into K12 schools. Although one of +the things that we'll learn is that uh + + align:start position:0% +the things that we'll learn is that uh + + + align:start position:0% +the things that we'll learn is that uh +when it gets there it kind of gets uh + + align:start position:0% +when it gets there it kind of gets uh + + + align:start position:0% +when it gets there it kind of gets uh +schoolified in ways that are horrific to + + align:start position:0% +schoolified in ways that are horrific to + + + align:start position:0% +schoolified in ways that are horrific to +the people who made it. But uh more to + + align:start position:0% +the people who made it. But uh more to + + + align:start position:0% +the people who made it. But uh more to +follow when they discuss that uh on + + align:start position:0% +follow when they discuss that uh on + + + align:start position:0% +follow when they discuss that uh on +Monday. Great. Have a wonderful uh rest + + align:start position:0% +Monday. Great. Have a wonderful uh rest + + + align:start position:0% +Monday. Great. Have a wonderful uh rest +of your week and weekend and I will see + + align:start position:0% +of your week and weekend and I will see + + + align:start position:0% +of your week and weekend and I will see +you next week. \ No newline at end of file diff --git a/QCA3zOe2xdA.txt b/QCA3zOe2xdA.txt new file mode 100644 index 0000000000000000000000000000000000000000..128e65bd9c9f3da64337edd6af67af0ccba8e842 --- /dev/null +++ b/QCA3zOe2xdA.txt @@ -0,0 +1,1555 @@ +align:start position:0% + +we can consider a given coordinate + + align:start position:0% +we can consider a given coordinate + + + align:start position:0% +we can consider a given coordinate +system as a reference frame within which + + align:start position:0% +system as a reference frame within which + + + align:start position:0% +system as a reference frame within which +we can describe the kinematics of an + + align:start position:0% +we can describe the kinematics of an + + + align:start position:0% +we can describe the kinematics of an +object by the kinematics I mean the + + align:start position:0% +object by the kinematics I mean the + + + align:start position:0% +object by the kinematics I mean the +position the velocity and the + + align:start position:0% +position the velocity and the + + + align:start position:0% +position the velocity and the +acceleration as a function of time + + align:start position:0% +acceleration as a function of time + + + align:start position:0% +acceleration as a function of time +basically a geometric description of the + + align:start position:0% +basically a geometric description of the + + + align:start position:0% +basically a geometric description of the +motion some aspects of these kinematics + + align:start position:0% +motion some aspects of these kinematics + + + align:start position:0% +motion some aspects of these kinematics +will look different in different + + align:start position:0% +will look different in different + + + align:start position:0% +will look different in different +reference frames and I'd like to examine + + align:start position:0% +reference frames and I'd like to examine + + + align:start position:0% +reference frames and I'd like to examine +that now first I want to Define what I + + align:start position:0% +that now first I want to Define what I + + + align:start position:0% +that now first I want to Define what I +mean by an inertial reference frame an + + align:start position:0% +mean by an inertial reference frame an + + + align:start position:0% +mean by an inertial reference frame an +inertial reference frame is one in which + + align:start position:0% +inertial reference frame is one in which + + + align:start position:0% +inertial reference frame is one in which +an isolated body one with no net force + + align:start position:0% +an isolated body one with no net force + + + align:start position:0% +an isolated body one with no net force +acting on it moves at constant velocity + + align:start position:0% +acting on it moves at constant velocity + + + align:start position:0% +acting on it moves at constant velocity +where that constant velocity might be + + align:start position:0% +where that constant velocity might be + + + align:start position:0% +where that constant velocity might be +zero another way of saying this is that + + align:start position:0% +zero another way of saying this is that + + + align:start position:0% +zero another way of saying this is that +an inertial reference frame is one in + + align:start position:0% +an inertial reference frame is one in + + + align:start position:0% +an inertial reference frame is one in +which Newton's Laws of Motion apply + + align:start position:0% +which Newton's Laws of Motion apply + + + align:start position:0% +which Newton's Laws of Motion apply +recall that Newton's first law of motion + + align:start position:0% +recall that Newton's first law of motion + + + align:start position:0% +recall that Newton's first law of motion +states that an isolated object with no + + align:start position:0% +states that an isolated object with no + + + align:start position:0% +states that an isolated object with no +forces acting on it moves at constant + + align:start position:0% +forces acting on it moves at constant + + + align:start position:0% +forces acting on it moves at constant +velocity so let's begin by considering a + + align:start position:0% +velocity so let's begin by considering a + + + align:start position:0% +velocity so let's begin by considering a +an observer in a particular reference + + align:start position:0% +an observer in a particular reference + + + align:start position:0% +an observer in a particular reference +frame we'll call that reference frame s + + align:start position:0% +frame we'll call that reference frame s + + + align:start position:0% +frame we'll call that reference frame s +and denoted by uh cordoes X and Y + + align:start position:0% +and denoted by uh cordoes X and Y + + + align:start position:0% +and denoted by uh cordoes X and Y +and let's consider an + + align:start position:0% +and let's consider an + + + align:start position:0% +and let's consider an +object that in that in that reference + + align:start position:0% +object that in that in that reference + + + align:start position:0% +object that in that in that reference +frame is at a position Vector small R we + + align:start position:0% +frame is at a position Vector small R we + + + align:start position:0% +frame is at a position Vector small R we +can then consider a second reference + + align:start position:0% +can then consider a second reference + + + align:start position:0% +can then consider a second reference +frame which I'll call the frame S Prime + + align:start position:0% +frame which I'll call the frame S Prime + + + align:start position:0% +frame which I'll call the frame S Prime +and I'll denote that with coordinate + + align:start position:0% +and I'll denote that with coordinate + + + align:start position:0% +and I'll denote that with coordinate +axes X Prime and Y Prime in my example + + align:start position:0% +axes X Prime and Y Prime in my example + + + align:start position:0% +axes X Prime and Y Prime in my example +here I'm going to assume that the + + align:start position:0% +here I'm going to assume that the + + + align:start position:0% +here I'm going to assume that the +coordinate axes in frame S Prime are + + align:start position:0% +coordinate axes in frame S Prime are + + + align:start position:0% +coordinate axes in frame S Prime are +parallel to but displaced away from the + + align:start position:0% +parallel to but displaced away from the + + + align:start position:0% +parallel to but displaced away from the +coordinate axes in frame s more + + align:start position:0% +coordinate axes in frame s more + + + align:start position:0% +coordinate axes in frame s more +generally we could have the S Prime + + align:start position:0% +generally we could have the S Prime + + + align:start position:0% +generally we could have the S Prime +coordinate axes rotated with respect to + + align:start position:0% +coordinate axes rotated with respect to + + + align:start position:0% +coordinate axes rotated with respect to +the frame s axis that's a complication + + align:start position:0% +the frame s axis that's a complication + + + align:start position:0% +the frame s axis that's a complication +I'm not going to add now but + + align:start position:0% +I'm not going to add now but + + + align:start position:0% +I'm not going to add now but +conceptually it's not really different + + align:start position:0% +conceptually it's not really different + + + align:start position:0% +conceptually it's not really different +for Simplicity we'll uh stick to + + align:start position:0% +for Simplicity we'll uh stick to + + + align:start position:0% +for Simplicity we'll uh stick to +parallel axes in this example so imagine + + align:start position:0% +parallel axes in this example so imagine + + + align:start position:0% +parallel axes in this example so imagine +we have two observers one in frame S at + + align:start position:0% +we have two observers one in frame S at + + + align:start position:0% +we have two observers one in frame S at +the origin and one at the origin of + + align:start position:0% +the origin and one at the origin of + + + align:start position:0% +the origin and one at the origin of +frame S Prime both looking at the same + + align:start position:0% +frame S Prime both looking at the same + + + align:start position:0% +frame S Prime both looking at the same +object Observer s will measure a + + align:start position:0% +object Observer s will measure a + + + align:start position:0% +object Observer s will measure a +position Vector little r Observer S + + align:start position:0% +position Vector little r Observer S + + + align:start position:0% +position Vector little r Observer S +Prime will measure a position Vector + + align:start position:0% +Prime will measure a position Vector + + + align:start position:0% +Prime will measure a position Vector +little r Prime the two observers have a + + align:start position:0% +little r Prime the two observers have a + + + align:start position:0% +little r Prime the two observers have a +relative position Vector capital r which + + align:start position:0% +relative position Vector capital r which + + + align:start position:0% +relative position Vector capital r which +is the position of S Prime relative to + + align:start position:0% +is the position of S Prime relative to + + + align:start position:0% +is the position of S Prime relative to +the origin of frame s so what we'd like + + align:start position:0% +the origin of frame s so what we'd like + + + align:start position:0% +the origin of frame s so what we'd like +to see is how are these different + + align:start position:0% +to see is how are these different + + + align:start position:0% +to see is how are these different +position vectors related well from the + + align:start position:0% +position vectors related well from the + + + align:start position:0% +position vectors related well from the +geometry of the diagram we can see that + + align:start position:0% +geometry of the diagram we can see that + + + align:start position:0% +geometry of the diagram we can see that +the position measured by Observer s + + align:start position:0% +the position measured by Observer s + + + align:start position:0% +the position measured by Observer s +which is just + + align:start position:0% + + + + align:start position:0% + +R is equal to the position of Observer S + + align:start position:0% +R is equal to the position of Observer S + + + align:start position:0% +R is equal to the position of Observer S +Prime relative to Observer s which is + + align:start position:0% +Prime relative to Observer s which is + + + align:start position:0% +Prime relative to Observer s which is +capital r plus the position Vector + + align:start position:0% +capital r plus the position Vector + + + align:start position:0% +capital r plus the position Vector +measured by The Observer at S Prime + + align:start position:0% +measured by The Observer at S Prime + + + align:start position:0% +measured by The Observer at S Prime +which + + align:start position:0% +which + + + align:start position:0% +which +is little r Prime I can rewrite that if + + align:start position:0% +is little r Prime I can rewrite that if + + + align:start position:0% +is little r Prime I can rewrite that if +I'd like to + + align:start position:0% +I'd like to + + + align:start position:0% +I'd like to +write the position measured by The + + align:start position:0% +write the position measured by The + + + align:start position:0% +write the position measured by The +Observer S Prime in terms of what's + + align:start position:0% +Observer S Prime in terms of what's + + + align:start position:0% +Observer S Prime in terms of what's +measured by The Observer at S I could + + align:start position:0% +measured by The Observer at S I could + + + align:start position:0% +measured by The Observer at S I could +just rearrange this and write that + + align:start position:0% +just rearrange this and write that + + + align:start position:0% +just rearrange this and write that +little r Prime time is equal to little r + + align:start position:0% +little r Prime time is equal to little r + + + align:start position:0% +little r Prime time is equal to little r +minus capital + + align:start position:0% + + + + align:start position:0% + +r now let's add a further complication + + align:start position:0% +r now let's add a further complication + + + align:start position:0% +r now let's add a further complication +and assume that the Observer S Prime is + + align:start position:0% +and assume that the Observer S Prime is + + + align:start position:0% +and assume that the Observer S Prime is +not just at a different location from + + align:start position:0% +not just at a different location from + + + align:start position:0% +not just at a different location from +The Observer of s but is moving at + + align:start position:0% +The Observer of s but is moving at + + + align:start position:0% +The Observer of s but is moving at +constant velocity relative to frame s so + + align:start position:0% +constant velocity relative to frame s so + + + align:start position:0% +constant velocity relative to frame s so +we'll assume that frame S Prime is + + align:start position:0% +we'll assume that frame S Prime is + + + align:start position:0% +we'll assume that frame S Prime is +moving at constant velocity with respect + + align:start position:0% +moving at constant velocity with respect + + + align:start position:0% +moving at constant velocity with respect +to frame s at a constant velocity vector + + align:start position:0% +to frame s at a constant velocity vector + + + align:start position:0% +to frame s at a constant velocity vector +v okay + + align:start position:0% +v okay + + + align:start position:0% +v okay +so V + + align:start position:0% + + + + align:start position:0% + +Vector is a constant and in that case my + + align:start position:0% +Vector is a constant and in that case my + + + align:start position:0% +Vector is a constant and in that case my +offset of Observer S Prime relative to + + align:start position:0% +offset of Observer S Prime relative to + + + align:start position:0% +offset of Observer S Prime relative to +Observer s which is the vector capital r + + align:start position:0% +Observer s which is the vector capital r + + + align:start position:0% +Observer s which is the vector capital r +is a function of + + align:start position:0% +is a function of + + + align:start position:0% +is a function of +time so capital r is a function of time + + align:start position:0% +time so capital r is a function of time + + + align:start position:0% +time so capital r is a function of time +and it's given by the offset at Time + + align:start position:0% +and it's given by the offset at Time + + + align:start position:0% +and it's given by the offset at Time +Zero which I will call all capital r + + align:start position:0% + + + + align:start position:0% + +not plus the + + align:start position:0% +not plus the + + + align:start position:0% +not plus the +elapsed motion due to the constant + + align:start position:0% +elapsed motion due to the constant + + + align:start position:0% +elapsed motion due to the constant +velocity which is capital V time + + align:start position:0% +velocity which is capital V time + + + align:start position:0% +velocity which is capital V time +time so since capital r is a function of + + align:start position:0% +time so since capital r is a function of + + + align:start position:0% +time so since capital r is a function of +time that tells me that in this equation + + align:start position:0% +time that tells me that in this equation + + + align:start position:0% +time that tells me that in this equation +little RP Prime the position Vector + + align:start position:0% +little RP Prime the position Vector + + + align:start position:0% +little RP Prime the position Vector +measured by The Observer in frame S + + align:start position:0% +measured by The Observer in frame S + + + align:start position:0% +measured by The Observer in frame S +Prime is also going to be a function of + + align:start position:0% +Prime is also going to be a function of + + + align:start position:0% +Prime is also going to be a function of +time even if + + align:start position:0% +time even if + + + align:start position:0% +time even if +Capital sorry even if little r is a + + align:start position:0% +Capital sorry even if little r is a + + + align:start position:0% +Capital sorry even if little r is a +constant so notice what that means if + + align:start position:0% +constant so notice what that means if + + + align:start position:0% +constant so notice what that means if +the object is at rest in frame + + align:start position:0% +the object is at rest in frame + + + align:start position:0% +the object is at rest in frame +s the object will appear to be moving + + align:start position:0% +s the object will appear to be moving + + + align:start position:0% +s the object will appear to be moving +its position Vector will be time + + align:start position:0% +its position Vector will be time + + + align:start position:0% +its position Vector will be time +dependent in frame S Prime because + + align:start position:0% +dependent in frame S Prime because + + + align:start position:0% +dependent in frame S Prime because +capital r the location of S Prime + + align:start position:0% +capital r the location of S Prime + + + align:start position:0% +capital r the location of S Prime +relative to S is + + align:start position:0% +relative to S is + + + align:start position:0% +relative to S is +changing so this relation tells us how + + align:start position:0% +changing so this relation tells us how + + + align:start position:0% +changing so this relation tells us how +the position vectors in the two frames + + align:start position:0% +the position vectors in the two frames + + + align:start position:0% +the position vectors in the two frames +are related what about the veloc + + align:start position:0% +are related what about the veloc + + + align:start position:0% +are related what about the veloc +ities well to compute how the velocities + + align:start position:0% +ities well to compute how the velocities + + + align:start position:0% +ities well to compute how the velocities +are related we can just take the time + + align:start position:0% +are related we can just take the time + + + align:start position:0% +are related we can just take the time +derivative of the relation of the + + align:start position:0% +derivative of the relation of the + + + align:start position:0% +derivative of the relation of the +position vectors so in this particular + + align:start position:0% +position vectors so in this particular + + + align:start position:0% +position vectors so in this particular +case we have that the time + + align:start position:0% +case we have that the time + + + align:start position:0% +case we have that the time +derivative of the S Prime position D + + align:start position:0% +derivative of the S Prime position D + + + align:start position:0% +derivative of the S Prime position D +little r Prime DT is equal to the time + + align:start position:0% +little r Prime DT is equal to the time + + + align:start position:0% +little r Prime DT is equal to the time +derivative of the position in frame s + + align:start position:0% +derivative of the position in frame s + + + align:start position:0% +derivative of the position in frame s +which is D little r DT minus the time + + align:start position:0% +which is D little r DT minus the time + + + align:start position:0% +which is D little r DT minus the time +derivative of the offset of S Prime + + align:start position:0% +derivative of the offset of S Prime + + + align:start position:0% +derivative of the offset of S Prime +relative to S so that's minus D capital + + align:start position:0% +relative to S so that's minus D capital + + + align:start position:0% +relative to S so that's minus D capital +r DT and I can rewrite that in terms of + + align:start position:0% +r DT and I can rewrite that in terms of + + + align:start position:0% +r DT and I can rewrite that in terms of +symbols for the velocity so I have + + align:start position:0% +symbols for the velocity so I have + + + align:start position:0% +symbols for the velocity so I have +here the velocity Little V Prime which + + align:start position:0% +here the velocity Little V Prime which + + + align:start position:0% +here the velocity Little V Prime which +is the velocity measured by an observer + + align:start position:0% +is the velocity measured by an observer + + + align:start position:0% +is the velocity measured by an observer +in frame S Prime and that's equal to the + + align:start position:0% +in frame S Prime and that's equal to the + + + align:start position:0% +in frame S Prime and that's equal to the +velocity Little V which is the velocity + + align:start position:0% +velocity Little V which is the velocity + + + align:start position:0% +velocity Little V which is the velocity +measured by frame + + align:start position:0% +measured by frame + + + align:start position:0% +measured by frame +s minus D capital r DT which we see is + + align:start position:0% +s minus D capital r DT which we see is + + + align:start position:0% +s minus D capital r DT which we see is +just + + align:start position:0% +just + + + align:start position:0% +just +capital V Vector which is the velocity + + align:start position:0% +capital V Vector which is the velocity + + + align:start position:0% +capital V Vector which is the velocity +of S Prime relative to S so this is how + + align:start position:0% +of S Prime relative to S so this is how + + + align:start position:0% +of S Prime relative to S so this is how +the velocities are related and again + + align:start position:0% +the velocities are related and again + + + align:start position:0% +the velocities are related and again +notice that if the object is stationary + + align:start position:0% +notice that if the object is stationary + + + align:start position:0% +notice that if the object is stationary +in one frame it will still have it will + + align:start position:0% +in one frame it will still have it will + + + align:start position:0% +in one frame it will still have it will +be so if it's zero in one frame it will + + align:start position:0% +be so if it's zero in one frame it will + + + align:start position:0% +be so if it's zero in one frame it will +be nonzero in the other frame so in + + align:start position:0% +be nonzero in the other frame so in + + + align:start position:0% +be nonzero in the other frame so in +general you will measure different + + align:start position:0% +general you will measure different + + + align:start position:0% +general you will measure different +velocities in the different frames even + + align:start position:0% +velocities in the different frames even + + + align:start position:0% +velocities in the different frames even +if one of those velocities is + + align:start position:0% +if one of those velocities is + + + align:start position:0% +if one of those velocities is +zero now how are the acceleration + + align:start position:0% +zero now how are the acceleration + + + align:start position:0% +zero now how are the acceleration +related well again we can just take the + + align:start position:0% +related well again we can just take the + + + align:start position:0% +related well again we can just take the +time derivative of the velocities to to + + align:start position:0% +time derivative of the velocities to to + + + align:start position:0% +time derivative of the velocities to to +figure out what the relationship of the + + align:start position:0% +figure out what the relationship of the + + + align:start position:0% +figure out what the relationship of the +accelerations is so differentiating this + + align:start position:0% +accelerations is so differentiating this + + + align:start position:0% +accelerations is so differentiating this +equation I have that D Little V Prime DT + + align:start position:0% +equation I have that D Little V Prime DT + + + align:start position:0% +equation I have that D Little V Prime DT +is equal to D Little V DT minus + + align:start position:0% +is equal to D Little V DT minus + + + align:start position:0% +is equal to D Little V DT minus +D capital V DT but here something + + align:start position:0% +D capital V DT but here something + + + align:start position:0% +D capital V DT but here something +interesting happens because remember we + + align:start position:0% +interesting happens because remember we + + + align:start position:0% +interesting happens because remember we +said that capital V is a constant vector + + align:start position:0% +said that capital V is a constant vector + + + align:start position:0% +said that capital V is a constant vector +and remember capital V is the velocity + + align:start position:0% +and remember capital V is the velocity + + + align:start position:0% +and remember capital V is the velocity +that frame S Prime has relative to frame + + align:start position:0% +that frame S Prime has relative to frame + + + align:start position:0% +that frame S Prime has relative to frame +s okay so since capital V is a constant + + align:start position:0% +s okay so since capital V is a constant + + + align:start position:0% +s okay so since capital V is a constant +that means that this term goes to zero + + align:start position:0% +that means that this term goes to zero + + + align:start position:0% +that means that this term goes to zero +and so we see that the acceleration in + + align:start position:0% +and so we see that the acceleration in + + + align:start position:0% +and so we see that the acceleration in +frame S Prime is equal to the + + align:start position:0% +frame S Prime is equal to the + + + align:start position:0% +frame S Prime is equal to the +acceleration in frame a so if I have two + + align:start position:0% +acceleration in frame a so if I have two + + + align:start position:0% +acceleration in frame a so if I have two +reference frames one moving at a + + align:start position:0% +reference frames one moving at a + + + align:start position:0% +reference frames one moving at a +constant velocity relative to the the + + align:start position:0% +constant velocity relative to the the + + + align:start position:0% +constant velocity relative to the the +other in general I will measure + + align:start position:0% +other in general I will measure + + + align:start position:0% +other in general I will measure +different positions and different + + align:start position:0% +different positions and different + + + align:start position:0% +different positions and different +velocities for an object as measured by + + align:start position:0% +velocities for an object as measured by + + + align:start position:0% +velocities for an object as measured by +the two frames however the accelerations + + align:start position:0% +the two frames however the accelerations + + + align:start position:0% +the two frames however the accelerations +measured in both frames will be + + align:start position:0% + + + + align:start position:0% + +identical because the accelerations are + + align:start position:0% +identical because the accelerations are + + + align:start position:0% +identical because the accelerations are +identical we'll see that Newton's Laws + + align:start position:0% +identical we'll see that Newton's Laws + + + align:start position:0% +identical we'll see that Newton's Laws +will look identical in the two + + align:start position:0% +will look identical in the two + + + align:start position:0% +will look identical in the two +frames and we can see that in the + + align:start position:0% +frames and we can see that in the + + + align:start position:0% +frames and we can see that in the +following way in frame s + + align:start position:0% +following way in frame s + + + align:start position:0% +following way in frame s +we have that the force is equal to the + + align:start position:0% +we have that the force is equal to the + + + align:start position:0% +we have that the force is equal to the +mass times the acceleration in frame S + + align:start position:0% +mass times the acceleration in frame S + + + align:start position:0% +mass times the acceleration in frame S +Prime the force F Prime is equal to the + + align:start position:0% +Prime the force F Prime is equal to the + + + align:start position:0% +Prime the force F Prime is equal to the +mass time a + + align:start position:0% + + + + align:start position:0% + +prime but a + + align:start position:0% + + + + align:start position:0% + +prime is equal to a as we calculated + + align:start position:0% +prime is equal to a as we calculated + + + align:start position:0% +prime is equal to a as we calculated +here so we see that the forces in the + + align:start position:0% +here so we see that the forces in the + + + align:start position:0% +here so we see that the forces in the +two frames are ident identical even + + align:start position:0% +two frames are ident identical even + + + align:start position:0% +two frames are ident identical even +though the positions and velocities in + + align:start position:0% +though the positions and velocities in + + + align:start position:0% +though the positions and velocities in +general will be different as measured in + + align:start position:0% +general will be different as measured in + + + align:start position:0% +general will be different as measured in +the two frames for the same + + align:start position:0% +the two frames for the same + + + align:start position:0% +the two frames for the same +object but the accelerations will be + + align:start position:0% +object but the accelerations will be + + + align:start position:0% +object but the accelerations will be +identical and so the forces will be + + align:start position:0% +identical and so the forces will be + + + align:start position:0% +identical and so the forces will be +identical so if one of these reference + + align:start position:0% +identical so if one of these reference + + + align:start position:0% +identical so if one of these reference +frames is an inertial frame one in which + + align:start position:0% +frames is an inertial frame one in which + + + align:start position:0% +frames is an inertial frame one in which +an isolated body moves at constant + + align:start position:0% +an isolated body moves at constant + + + align:start position:0% +an isolated body moves at constant +velocity then any other frame moving at + + align:start position:0% +velocity then any other frame moving at + + + align:start position:0% +velocity then any other frame moving at +constant velocity with respect to the + + align:start position:0% +constant velocity with respect to the + + + align:start position:0% +constant velocity with respect to the +first frame will also be an inertial + + align:start position:0% +first frame will also be an inertial + + + align:start position:0% +first frame will also be an inertial +frame + + align:start position:0% +frame + + + align:start position:0% +frame +what this means is that you're always + + align:start position:0% +what this means is that you're always + + + align:start position:0% +what this means is that you're always +free to transform from one inertial + + align:start position:0% +free to transform from one inertial + + + align:start position:0% +free to transform from one inertial +frame to + + align:start position:0% + + + + align:start position:0% + +another and what that means is that you + + align:start position:0% +another and what that means is that you + + + align:start position:0% +another and what that means is that you +can always transform to another frame + + align:start position:0% +can always transform to another frame + + + align:start position:0% +can always transform to another frame +that is moving at constant velocity with + + align:start position:0% +that is moving at constant velocity with + + + align:start position:0% +that is moving at constant velocity with +respect to an original inertial frame \ No newline at end of file diff --git a/QHaAoQQy07I.txt b/QHaAoQQy07I.txt new file mode 100644 index 0000000000000000000000000000000000000000..01f2fdeaaa369bde9e32be5344a812006ded9770 --- /dev/null +++ b/QHaAoQQy07I.txt @@ -0,0 +1,744 @@ +align:start position:0% + +hello and welcome back to recitation in + + align:start position:0% +hello and welcome back to recitation in + + + align:start position:0% +hello and welcome back to recitation in +this problem I'd like you to compute the + + align:start position:0% +this problem I'd like you to compute the + + + align:start position:0% +this problem I'd like you to compute the +area of a triangle this triangle sits in + + align:start position:0% +area of a triangle this triangle sits in + + + align:start position:0% +area of a triangle this triangle sits in +space and it has its three vertices uh + + align:start position:0% +space and it has its three vertices uh + + + align:start position:0% +space and it has its three vertices uh +labeled here as P1 P2 and P3 so we're + + align:start position:0% +labeled here as P1 P2 and P3 so we're + + + align:start position:0% +labeled here as P1 P2 and P3 so we're +going to compute this area and we're + + align:start position:0% +going to compute this area and we're + + + align:start position:0% +going to compute this area and we're +going to do it using the cross product + + align:start position:0% +going to do it using the cross product + + + align:start position:0% +going to do it using the cross product +which we learned about in lecture so why + + align:start position:0% +which we learned about in lecture so why + + + align:start position:0% +which we learned about in lecture so why +don't you take some time to work this + + align:start position:0% +don't you take some time to work this + + + align:start position:0% +don't you take some time to work this +out pause the video and we'll check back + + align:start position:0% +out pause the video and we'll check back + + + align:start position:0% +out pause the video and we'll check back +in a minute and see how did + + align:start position:0% + + + + align:start position:0% + +it hello and welcome back so the first + + align:start position:0% +it hello and welcome back so the first + + + align:start position:0% +it hello and welcome back so the first +thing that I like to do with a problem + + align:start position:0% +thing that I like to do with a problem + + + align:start position:0% +thing that I like to do with a problem +like this is I like to uh draw a picture + + align:start position:0% +like this is I like to uh draw a picture + + + align:start position:0% +like this is I like to uh draw a picture +so I can kind of think about what's + + align:start position:0% +so I can kind of think about what's + + + align:start position:0% +so I can kind of think about what's +going on so we have this + + align:start position:0% + + + + align:start position:0% + +triangle we have this triangle sitting + + align:start position:0% +triangle we have this triangle sitting + + + align:start position:0% +triangle we have this triangle sitting +out in space and uh we know that we want + + align:start position:0% +out in space and uh we know that we want + + + align:start position:0% +out in space and uh we know that we want +to take a cross product in order to + + align:start position:0% +to take a cross product in order to + + + align:start position:0% +to take a cross product in order to +compute uh compute uh its area uh but we + + align:start position:0% +compute uh compute uh its area uh but we + + + align:start position:0% +compute uh compute uh its area uh but we +need to be careful cross product uh + + align:start position:0% +need to be careful cross product uh + + + align:start position:0% +need to be careful cross product uh +doesn't make sense to take cross product + + align:start position:0% +doesn't make sense to take cross product + + + align:start position:0% +doesn't make sense to take cross product +of points what makes sense is to take + + align:start position:0% +of points what makes sense is to take + + + align:start position:0% +of points what makes sense is to take +cross product of vectors so the first + + align:start position:0% +cross product of vectors so the first + + + align:start position:0% +cross product of vectors so the first +thing that we need to do is build some + + align:start position:0% +thing that we need to do is build some + + + align:start position:0% +thing that we need to do is build some +vectors that describe this triangle and + + align:start position:0% +vectors that describe this triangle and + + + align:start position:0% +vectors that describe this triangle and +the vectors that we need to + + align:start position:0% + + + + align:start position:0% + +build are P1 + + align:start position:0% + + + + align:start position:0% + +P2 and P1 P3 since we're going to use + + align:start position:0% +P2 and P1 P3 since we're going to use + + + align:start position:0% +P2 and P1 P3 since we're going to use +these in a minute let's go ahead and + + align:start position:0% +these in a minute let's go ahead and + + + align:start position:0% +these in a minute let's go ahead and +compute them now so + + align:start position:0% + + + + align:start position:0% + +P1 P2 is just the difference of P2 minus + + align:start position:0% +P1 P2 is just the difference of P2 minus + + + align:start position:0% +P1 P2 is just the difference of P2 minus +P1 so we get uh 0 minus a negative 1 so + + align:start position:0% +P1 so we get uh 0 minus a negative 1 so + + + align:start position:0% +P1 so we get uh 0 minus a negative 1 so +we get + + align:start position:0% +we get + + + align:start position:0% +we get + + align:start position:0% + + + align:start position:0% +2 and one let me just check my notes to + + align:start position:0% +2 and one let me just check my notes to + + + align:start position:0% +2 and one let me just check my notes to +make sure I do that right good and + + align:start position:0% + + + + align:start position:0% + +P1 P3 we get again 0 minus a negative 1 + + align:start position:0% +P1 P3 we get again 0 minus a negative 1 + + + align:start position:0% +P1 P3 we get again 0 minus a negative 1 +so 1 we get minus one and then we get + + align:start position:0% +so 1 we get minus one and then we get + + + align:start position:0% +so 1 we get minus one and then we get +one let me again check my notes very + + align:start position:0% +one let me again check my notes very + + + align:start position:0% +one let me again check my notes very +good okay so now that we have these + + align:start position:0% +good okay so now that we have these + + + align:start position:0% +good okay so now that we have these +vectors we need to remember that if we + + align:start position:0% +vectors we need to remember that if we + + + align:start position:0% +vectors we need to remember that if we +take the absolute + + align:start position:0% +take the absolute + + + align:start position:0% +take the absolute +value of + + align:start position:0% +value of + + + align:start position:0% +value of +P1 P2 cross product with P1 P3 + + align:start position:0% + + + + align:start position:0% + +this will be equal to the + + align:start position:0% +this will be equal to the + + + align:start position:0% +this will be equal to the +area of + + align:start position:0% + + + + align:start position:0% + +um the + + align:start position:0% +um the + + + align:start position:0% +um the +parallelogram uh they + + align:start position:0% + + + + align:start position:0% + +enclose so let's get started by + + align:start position:0% +enclose so let's get started by + + + align:start position:0% +enclose so let's get started by +Computing this cross product so + + align:start position:0% +Computing this cross product so + + + align:start position:0% +Computing this cross product so +P1 + + align:start position:0% +P1 + + + align:start position:0% +P1 +P2 plus + + align:start position:0% +P2 plus + + + align:start position:0% +P2 plus +P2 P3 + + align:start position:0% + + + + align:start position:0% + +so remember to compute a cross product + + align:start position:0% +so remember to compute a cross product + + + align:start position:0% +so remember to compute a cross product +we uh take the determinant of a matrix + + align:start position:0% +we uh take the determinant of a matrix + + + align:start position:0% +we uh take the determinant of a matrix +where we put in our unit normal vectors + + align:start position:0% +where we put in our unit normal vectors + + + align:start position:0% +where we put in our unit normal vectors +i j and + + align:start position:0% +i j and + + + align:start position:0% +i j and +k and then we enter in uh the the + + align:start position:0% +k and then we enter in uh the the + + + align:start position:0% +k and then we enter in uh the the +remaining entries of the Matrix are just + + align:start position:0% +remaining entries of the Matrix are just + + + align:start position:0% +remaining entries of the Matrix are just +the entries of our vectors so we do 1 2 + + align:start position:0% +the entries of our vectors so we do 1 2 + + + align:start position:0% +the entries of our vectors so we do 1 2 +1 and 1 - one + + align:start position:0% +1 and 1 - one + + + align:start position:0% +1 and 1 - one +1 okay and so we can compute + + align:start position:0% +1 okay and so we can compute + + + align:start position:0% +1 okay and so we can compute +this and we + + align:start position:0% +this and we + + + align:start position:0% +this and we +get so the I component we get 2 minus a + + align:start position:0% +get so the I component we get 2 minus a + + + align:start position:0% +get so the I component we get 2 minus a +- 1 so we get + + align:start position:0% +- 1 so we get + + + align:start position:0% +- 1 so we get +3 now the J component if we look at the + + align:start position:0% +3 now the J component if we look at the + + + align:start position:0% +3 now the J component if we look at the +co-actor matrix it's just one one one + + align:start position:0% +co-actor matrix it's just one one one + + + align:start position:0% +co-actor matrix it's just one one one +one and that has determinant zero so our + + align:start position:0% +one and that has determinant zero so our + + + align:start position:0% +one and that has determinant zero so our +middle component is just + + align:start position:0% +middle component is just + + + align:start position:0% +middle component is just +zero and finally the K component we get + + align:start position:0% +zero and finally the K component we get + + + align:start position:0% +zero and finally the K component we get +minus one uh minus another two so Al + + align:start position:0% +minus one uh minus another two so Al + + + align:start position:0% +minus one uh minus another two so Al +together we get minus + + align:start position:0% +together we get minus + + + align:start position:0% +together we get minus +3 so what that tells us now is that + + align:start position:0% +3 so what that tells us now is that + + + align:start position:0% +3 so what that tells us now is that +the um that this quantity here the the + + align:start position:0% +the um that this quantity here the the + + + align:start position:0% +the um that this quantity here the the +magnitude of the cross product is just + + align:start position:0% +magnitude of the cross product is just + + + align:start position:0% +magnitude of the cross product is just +uh 3 * the < TK of 2 just looking at the + + align:start position:0% +uh 3 * the < TK of 2 just looking at the + + + align:start position:0% +uh 3 * the < TK of 2 just looking at the +length of this Vector + + align:start position:0% +length of this Vector + + + align:start position:0% +length of this Vector +here so we're almost done but let's go + + align:start position:0% +here so we're almost done but let's go + + + align:start position:0% +here so we're almost done but let's go +back and look at what we had uh to start + + align:start position:0% +back and look at what we had uh to start + + + align:start position:0% +back and look at what we had uh to start +with we were interested in the Triangle + + align:start position:0% +with we were interested in the Triangle + + + align:start position:0% +with we were interested in the Triangle +over here uh which uh was enclosed by + + align:start position:0% +over here uh which uh was enclosed by + + + align:start position:0% +over here uh which uh was enclosed by +the vectors P1 P2 and the vectors P1 P3 + + align:start position:0% +the vectors P1 P2 and the vectors P1 P3 + + + align:start position:0% +the vectors P1 P2 and the vectors P1 P3 +and what we just computed is actually + + align:start position:0% +and what we just computed is actually + + + align:start position:0% +and what we just computed is actually +the area + + align:start position:0% + + + + align:start position:0% + +of of this parallelogram which as you + + align:start position:0% +of of this parallelogram which as you + + + align:start position:0% +of of this parallelogram which as you +can see is twice the area of the + + align:start position:0% +can see is twice the area of the + + + align:start position:0% +can see is twice the area of the +triangle that we're actually interested + + align:start position:0% +triangle that we're actually interested + + + align:start position:0% +triangle that we're actually interested +in so going back over here we see that + + align:start position:0% +in so going back over here we see that + + + align:start position:0% +in so going back over here we see that +the + + align:start position:0% +the + + + align:start position:0% +the +area of our + + align:start position:0% +area of our + + + align:start position:0% +area of our +triangle is equal to 3 < tk2 and we just + + align:start position:0% +triangle is equal to 3 < tk2 and we just + + + align:start position:0% +triangle is equal to 3 < tk2 and we just +need divide by two to get the triangle + + align:start position:0% +need divide by two to get the triangle + + + align:start position:0% +need divide by two to get the triangle +okay and I'll leave it at that \ No newline at end of file diff --git a/Qa7Xnn7ixpk.txt b/Qa7Xnn7ixpk.txt new file mode 100644 index 0000000000000000000000000000000000000000..9f250bc28e9047051ec5caff305bb3e97dd561f2 --- /dev/null +++ b/Qa7Xnn7ixpk.txt @@ -0,0 +1,11691 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay welcome welcome to the uh + + align:start position:0% +okay welcome welcome to the uh + + + align:start position:0% +okay welcome welcome to the uh +second uh + + align:start position:0% +second uh + + + align:start position:0% +second uh +discussion of networks and the second to + + align:start position:0% +discussion of networks and the second to + + + align:start position:0% +discussion of networks and the second to +last + + align:start position:0% +last + + + align:start position:0% +last +talk of a lecture of this course there's + + align:start position:0% +talk of a lecture of this course there's + + + align:start position:0% +talk of a lecture of this course there's +a very important set of + + align:start position:0% +a very important set of + + + align:start position:0% +a very important set of +lectures after that from the students + + align:start position:0% +lectures after that from the students + + + align:start position:0% +lectures after that from the students +i'm looking forward to + + align:start position:0% +i'm looking forward to + + + align:start position:0% +i'm looking forward to +so last time we talked about the + + align:start position:0% +so last time we talked about the + + + align:start position:0% +so last time we talked about the +mock use of computers to model various + + align:start position:0% +mock use of computers to model various + + + align:start position:0% +mock use of computers to model various +complicated systems in in + + align:start position:0% +complicated systems in in + + + align:start position:0% +complicated systems in in +mainly cellular systems + + align:start position:0% +mainly cellular systems + + + align:start position:0% +mainly cellular systems +ranging from + + align:start position:0% +ranging from + + + align:start position:0% +ranging from +highly cooperative even buy stable + + align:start position:0% +highly cooperative even buy stable + + + align:start position:0% +highly cooperative even buy stable +bifurcations that's sort of where the + + align:start position:0% +bifurcations that's sort of where the + + + align:start position:0% +bifurcations that's sort of where the +cell makes a decision + + align:start position:0% +cell makes a decision + + + align:start position:0% +cell makes a decision +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a discussion of chromosome copy number + + align:start position:0% +a discussion of chromosome copy number + + + align:start position:0% +a discussion of chromosome copy number +and its implications + + align:start position:0% +and its implications + + + align:start position:0% +and its implications +and a large + + align:start position:0% +and a large + + + align:start position:0% +and a large +chunk of time on flux balance + + align:start position:0% +chunk of time on flux balance + + + align:start position:0% +chunk of time on flux balance +optimization where we can look at + + align:start position:0% +optimization where we can look at + + + align:start position:0% +optimization where we can look at +many of these things from the standpoint + + align:start position:0% +many of these things from the standpoint + + + align:start position:0% +many of these things from the standpoint +of optimization + + align:start position:0% +of optimization + + + align:start position:0% +of optimization +now + + align:start position:0% +now + + + align:start position:0% +now +today + + align:start position:0% +today + + + align:start position:0% +today +to + + align:start position:0% +to + + + align:start position:0% +to +paraphrase a famous local politician we + + align:start position:0% +paraphrase a famous local politician we + + + align:start position:0% +paraphrase a famous local politician we +will ask not what computers can do for + + align:start position:0% +will ask not what computers can do for + + + align:start position:0% +will ask not what computers can do for +biology but for what biology can do for + + align:start position:0% +biology but for what biology can do for + + + align:start position:0% +biology but for what biology can do for +computers + + align:start position:0% +computers + + + align:start position:0% +computers +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and of course we'll go back and forth + + align:start position:0% +and of course we'll go back and forth + + + align:start position:0% +and of course we'll go back and forth +and and try to look at what kind of ex + + align:start position:0% +and and try to look at what kind of ex + + + align:start position:0% +and and try to look at what kind of ex +the this interesting dynamic between the + + align:start position:0% +the this interesting dynamic between the + + + align:start position:0% +the this interesting dynamic between the +experimental and the computational side + + align:start position:0% +experimental and the computational side + + + align:start position:0% +experimental and the computational side +and so how can biology aid algorithm + + align:start position:0% +and so how can biology aid algorithm + + + align:start position:0% +and so how can biology aid algorithm +development + + align:start position:0% +development + + + align:start position:0% +development +to return the favor and aid biology + + align:start position:0% +to return the favor and aid biology + + + align:start position:0% +to return the favor and aid biology +but not only algorithm development to + + align:start position:0% +but not only algorithm development to + + + align:start position:0% +but not only algorithm development to +not only inspiring algorithm development + + align:start position:0% +not only inspiring algorithm development + + + align:start position:0% +not only inspiring algorithm development +but actually implementing + + align:start position:0% +but actually implementing + + + align:start position:0% +but actually implementing +uh hardware and software + + align:start position:0% +uh hardware and software + + + align:start position:0% +uh hardware and software +in in + + align:start position:0% +in in + + + align:start position:0% +in in +biological systems we'll talk about that + + align:start position:0% +biological systems we'll talk about that + + + align:start position:0% +biological systems we'll talk about that +and + + align:start position:0% +and + + + align:start position:0% +and +ranging from molecular computing to + + align:start position:0% +ranging from molecular computing to + + + align:start position:0% +ranging from molecular computing to +cellular computing + + align:start position:0% +cellular computing + + + align:start position:0% +cellular computing +and then back to + + align:start position:0% +and then back to + + + align:start position:0% +and then back to +inspiring algorithms again + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +slide three what is it that we're really + + align:start position:0% +slide three what is it that we're really + + + align:start position:0% +slide three what is it that we're really +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +that + + align:start position:0% +that + + + align:start position:0% +that +computation needs in terms of aid how do + + align:start position:0% +computation needs in terms of aid how do + + + align:start position:0% +computation needs in terms of aid how do +we get uh what what are the what are the + + align:start position:0% +we get uh what what are the what are the + + + align:start position:0% +we get uh what what are the what are the +real issues here and we've mentioned a + + align:start position:0% +real issues here and we've mentioned a + + + align:start position:0% +real issues here and we've mentioned a +couple times in the course probably + + align:start position:0% +couple times in the course probably + + + align:start position:0% +couple times in the course probably +initially when we were talking about + + align:start position:0% +initially when we were talking about + + + align:start position:0% +initially when we were talking about +dynamic programming and related topics + + align:start position:0% +dynamic programming and related topics + + + align:start position:0% +dynamic programming and related topics +of how a problem in computer science + + align:start position:0% +of how a problem in computer science + + + align:start position:0% +of how a problem in computer science +scales + + align:start position:0% +scales + + + align:start position:0% +scales +typically you'll have one key input + + align:start position:0% +typically you'll have one key input + + + align:start position:0% +typically you'll have one key input +size in + + align:start position:0% +size in + + + align:start position:0% +size in +and then the running time or sometimes + + align:start position:0% +and then the running time or sometimes + + + align:start position:0% +and then the running time or sometimes +the memory has an upper bound which + + align:start position:0% +the memory has an upper bound which + + + align:start position:0% +the memory has an upper bound which +we've been referring to as the order of + + align:start position:0% +we've been referring to as the order of + + + align:start position:0% +we've been referring to as the order of +some function of that n where n is the + + align:start position:0% +some function of that n where n is the + + + align:start position:0% +some function of that n where n is the +length of the of a string or the size of + + align:start position:0% +length of the of a string or the size of + + + align:start position:0% +length of the of a string or the size of +the problem + + align:start position:0% +the problem + + + align:start position:0% +the problem +there are other uh symbols that are + + align:start position:0% +there are other uh symbols that are + + + align:start position:0% +there are other uh symbols that are +slightly more rarely used there's a in + + align:start position:0% +slightly more rarely used there's a in + + + align:start position:0% +slightly more rarely used there's a in +addition to the upper bound there's + + align:start position:0% +addition to the upper bound there's + + + align:start position:0% +addition to the upper bound there's +lower bound + + align:start position:0% +lower bound + + + align:start position:0% +lower bound +sometimes you can get an exact bound or + + align:start position:0% +sometimes you can get an exact bound or + + + align:start position:0% +sometimes you can get an exact bound or +equal bound + + align:start position:0% +equal bound + + + align:start position:0% +equal bound +and how does this play out when you have + + align:start position:0% +and how does this play out when you have + + + align:start position:0% +and how does this play out when you have +specific instances of n now of course + + align:start position:0% +specific instances of n now of course + + + align:start position:0% +specific instances of n now of course +this when you say that something's on + + align:start position:0% +this when you say that something's on + + + align:start position:0% +this when you say that something's on +the order of or upper bound of a + + align:start position:0% +the order of or upper bound of a + + + align:start position:0% +the order of or upper bound of a +function of n + + align:start position:0% +function of n + + + align:start position:0% +function of n +you don't always necessarily describe + + align:start position:0% +you don't always necessarily describe + + + align:start position:0% +you don't always necessarily describe +with the constants but to give you a + + align:start position:0% +with the constants but to give you a + + + align:start position:0% +with the constants but to give you a +ballpark when you have n ranging from + + align:start position:0% +ballpark when you have n ranging from + + + align:start position:0% +ballpark when you have n ranging from +one to a thousand and the and the + + align:start position:0% +one to a thousand and the and the + + + align:start position:0% +one to a thousand and the and the +polynomial + + align:start position:0% +polynomial + + + align:start position:0% +polynomial +uh ranging from + + align:start position:0% +uh ranging from + + + align:start position:0% +uh ranging from +linear to quadratic to tenth power then + + align:start position:0% +linear to quadratic to tenth power then + + + align:start position:0% +linear to quadratic to tenth power then +the exponential or + + align:start position:0% +the exponential or + + + align:start position:0% +the exponential or +for + + align:start position:0% +for + + + align:start position:0% +for +factorial + + align:start position:0% +factorial + + + align:start position:0% +factorial +and you can see that that for very small + + align:start position:0% +and you can see that that for very small + + + align:start position:0% +and you can see that that for very small +n you can get cases where a polynomial + + align:start position:0% +n you can get cases where a polynomial + + + align:start position:0% +n you can get cases where a polynomial +performance computation time can be + + align:start position:0% +performance computation time can be + + + align:start position:0% +performance computation time can be +longer than an exponential + + align:start position:0% +longer than an exponential + + + align:start position:0% +longer than an exponential +computation time so exponential isn't + + align:start position:0% +computation time so exponential isn't + + + align:start position:0% +computation time so exponential isn't +necessarily bad news depending on the + + align:start position:0% +necessarily bad news depending on the + + + align:start position:0% +necessarily bad news depending on the +size of your problem + + align:start position:0% +size of your problem + + + align:start position:0% +size of your problem +but it gets to be madness very quickly + + align:start position:0% +but it gets to be madness very quickly + + + align:start position:0% +but it gets to be madness very quickly +as in it increases you quickly get + + align:start position:0% +as in it increases you quickly get + + + align:start position:0% +as in it increases you quickly get +over large + + align:start position:0% +over large + + + align:start position:0% +over large +numbers on the far right hand side that + + align:start position:0% +numbers on the far right hand side that + + + align:start position:0% +numbers on the far right hand side that +are + + align:start position:0% +are + + + align:start position:0% +are +computationally intractable with any + + align:start position:0% +computationally intractable with any + + + align:start position:0% +computationally intractable with any +known computer + + align:start position:0% +known computer + + + align:start position:0% +known computer +so + + align:start position:0% +so + + + align:start position:0% +so +we mentioned computational complexity is + + align:start position:0% +we mentioned computational complexity is + + + align:start position:0% +we mentioned computational complexity is +one of the various definitions of + + align:start position:0% +one of the various definitions of + + + align:start position:0% +one of the various definitions of +complexity at the beginning of course + + align:start position:0% +complexity at the beginning of course + + + align:start position:0% +complexity at the beginning of course +this is not the one we chose to to be + + align:start position:0% +this is not the one we chose to to be + + + align:start position:0% +this is not the one we chose to to be +closest to the definition of living + + align:start position:0% +closest to the definition of living + + + align:start position:0% +closest to the definition of living +complexity but it's one that's very + + align:start position:0% +complexity but it's one that's very + + + align:start position:0% +complexity but it's one that's very +frequently used in the + + align:start position:0% +frequently used in the + + + align:start position:0% +frequently used in the +computer science field i just want to + + align:start position:0% +computer science field i just want to + + + align:start position:0% +computer science field i just want to +introduce a few of the terms here just + + align:start position:0% +introduce a few of the terms here just + + + align:start position:0% +introduce a few of the terms here just +so you've kind of heard them in this + + align:start position:0% +so you've kind of heard them in this + + + align:start position:0% +so you've kind of heard them in this +context + + align:start position:0% +context + + + align:start position:0% +context +we have + + align:start position:0% +we have + + + align:start position:0% +we have +and it basically refers to the + + align:start position:0% +and it basically refers to the + + + align:start position:0% +and it basically refers to the +issues brought up in the previous slide + + align:start position:0% +issues brought up in the previous slide + + + align:start position:0% +issues brought up in the previous slide +of whether it takes part whether it + + align:start position:0% +of whether it takes part whether it + + + align:start position:0% +of whether it takes part whether it +scales by a polynomial which is + + align:start position:0% +scales by a polynomial which is + + + align:start position:0% +scales by a polynomial which is +generally desirable whether it scales + + align:start position:0% +generally desirable whether it scales + + + align:start position:0% +generally desirable whether it scales +exponentially or worse + + align:start position:0% +exponentially or worse + + + align:start position:0% +exponentially or worse +and so we have a p of our problems that + + align:start position:0% +and so we have a p of our problems that + + + align:start position:0% +and so we have a p of our problems that +we can solve in polynomial deterministic + + align:start position:0% +we can solve in polynomial deterministic + + + align:start position:0% +we can solve in polynomial deterministic +time deterministic is just describes the + + align:start position:0% +time deterministic is just describes the + + + align:start position:0% +time deterministic is just describes the +fact that the algorithms will do the + + align:start position:0% +fact that the algorithms will do the + + + align:start position:0% +fact that the algorithms will do the +same thing time after time which is + + align:start position:0% +same thing time after time which is + + + align:start position:0% +same thing time after time which is +typical the sort of typical computer + + align:start position:0% +typical the sort of typical computer + + + align:start position:0% +typical the sort of typical computer +that we feel comfortable using + + align:start position:0% +that we feel comfortable using + + + align:start position:0% +that we feel comfortable using +and uh an example of this of problems in + + align:start position:0% +and uh an example of this of problems in + + + align:start position:0% +and uh an example of this of problems in +the p class the dynamic programming + + align:start position:0% +the p class the dynamic programming + + + align:start position:0% +the p class the dynamic programming +which we've used numerous times it + + align:start position:0% +which we've used numerous times it + + + align:start position:0% +which we've used numerous times it +scales polynomial and the polynomial + + align:start position:0% +scales polynomial and the polynomial + + + align:start position:0% +scales polynomial and the polynomial +just depends on the problem slightly + + align:start position:0% +just depends on the problem slightly + + + align:start position:0% +just depends on the problem slightly +from squared to the sixth power we've + + align:start position:0% +from squared to the sixth power we've + + + align:start position:0% +from squared to the sixth power we've +seen + + align:start position:0% +seen + + + align:start position:0% +seen +np + + align:start position:0% +np + + + align:start position:0% +np +is uh has a number of subsets but + + align:start position:0% +is uh has a number of subsets but + + + align:start position:0% +is uh has a number of subsets but +overall it means it's not + + align:start position:0% +overall it means it's not + + + align:start position:0% +overall it means it's not +determined as a polynomial time to get + + align:start position:0% +determined as a polynomial time to get + + + align:start position:0% +determined as a polynomial time to get +the solutions the solutions are + + align:start position:0% +the solutions the solutions are + + + align:start position:0% +the solutions the solutions are +checkable + + align:start position:0% +checkable + + + align:start position:0% +checkable +in polynomial time but uh + + align:start position:0% +in polynomial time but uh + + + align:start position:0% +in polynomial time but uh +are generally felt + + align:start position:0% +are generally felt + + + align:start position:0% +are generally felt +to to not be + + align:start position:0% +to to not be + + + align:start position:0% +to to not be +currently feasible in polynomial time + + align:start position:0% +currently feasible in polynomial time + + + align:start position:0% +currently feasible in polynomial time +for the determination as opposed to + + align:start position:0% +for the determination as opposed to + + + align:start position:0% +for the determination as opposed to +checking + + align:start position:0% +checking + + + align:start position:0% +checking +an example of this where we're actually + + align:start position:0% +an example of this where we're actually + + + align:start position:0% +an example of this where we're actually +the inventors of various + + align:start position:0% +the inventors of various + + + align:start position:0% +the inventors of various +um + + align:start position:0% +um + + + align:start position:0% +um +encryption schemes such as rsa they are + + align:start position:0% +encryption schemes such as rsa they are + + + align:start position:0% +encryption schemes such as rsa they are +in the sda referring to the last + + align:start position:0% +in the sda referring to the last + + + align:start position:0% +in the sda referring to the last +names of the authors + + align:start position:0% +names of the authors + + + align:start position:0% +names of the authors +in a certain sense they are banking on + + align:start position:0% +in a certain sense they are banking on + + + align:start position:0% +in a certain sense they are banking on +the + + align:start position:0% +the + + + align:start position:0% +the +difficulty + + align:start position:0% +difficulty + + + align:start position:0% +difficulty +of + + align:start position:0% +of + + + align:start position:0% +of +cracking these codes + + align:start position:0% +cracking these codes + + + align:start position:0% +cracking these codes +in + + align:start position:0% +in + + + align:start position:0% +in +polynomial time you can you can use the + + align:start position:0% +polynomial time you can you can use the + + + align:start position:0% +polynomial time you can you can use the +codes if you know it you can check it + + align:start position:0% +codes if you know it you can check it + + + align:start position:0% +codes if you know it you can check it +that is to say you can but you can't + + align:start position:0% +that is to say you can but you can't + + + align:start position:0% +that is to say you can but you can't +crack it unless someone comes through + + align:start position:0% +crack it unless someone comes through + + + align:start position:0% +crack it unless someone comes through +with breakthrough on the np problems + + align:start position:0% +with breakthrough on the np problems + + + align:start position:0% +with breakthrough on the np problems +because if you solve one of them you can + + align:start position:0% +because if you solve one of them you can + + + align:start position:0% +because if you solve one of them you can +solve + + align:start position:0% +solve + + + align:start position:0% +solve +all of them + + align:start position:0% +all of them + + + align:start position:0% +all of them +and then there's substance of this this + + align:start position:0% +and then there's substance of this this + + + align:start position:0% +and then there's substance of this this +is a little less critical for today's + + align:start position:0% +is a little less critical for today's + + + align:start position:0% +is a little less critical for today's +discussion but there's np complete + + align:start position:0% +discussion but there's np complete + + + align:start position:0% +discussion but there's np complete +which uh an example of which is so the + + align:start position:0% +which uh an example of which is so the + + + align:start position:0% +which uh an example of which is so the +traveling salesman + + align:start position:0% +traveling salesman + + + align:start position:0% +traveling salesman +can you get through all of all the + + align:start position:0% +can you get through all of all the + + + align:start position:0% +can you get through all of all the +vertices on the on the trip + + align:start position:0% +vertices on the on the trip + + + align:start position:0% +vertices on the on the trip +um with a mileage below certain some + + align:start position:0% +um with a mileage below certain some + + + align:start position:0% +um with a mileage below certain some +threshold + + align:start position:0% +threshold + + + align:start position:0% +threshold +and an mp hard version of that same + + align:start position:0% +and an mp hard version of that same + + + align:start position:0% +and an mp hard version of that same +thing is what's the minimum mileage that + + align:start position:0% +thing is what's the minimum mileage that + + + align:start position:0% +thing is what's the minimum mileage that +you can get not just less than x but + + align:start position:0% +you can get not just less than x but + + + align:start position:0% +you can get not just less than x but +you know how much less than x + + align:start position:0% +you know how much less than x + + + align:start position:0% +you know how much less than x +and the worst case scenario is + + align:start position:0% +and the worst case scenario is + + + align:start position:0% +and the worst case scenario is +undecidable where you really uh + + align:start position:0% +undecidable where you really uh + + + align:start position:0% +undecidable where you really uh +even given an unlimited amount of time + + align:start position:0% +even given an unlimited amount of time + + + align:start position:0% +even given an unlimited amount of time +and space you can't tell whether it is + + align:start position:0% +and space you can't tell whether it is + + + align:start position:0% +and space you can't tell whether it is +and the classic one is the program + + align:start position:0% +and the classic one is the program + + + align:start position:0% +and the classic one is the program +halting problem where you don't know + + align:start position:0% +halting problem where you don't know + + + align:start position:0% +halting problem where you don't know +whether your program is going to halt + + align:start position:0% +whether your program is going to halt + + + align:start position:0% +whether your program is going to halt +and probably all of you run into that + + align:start position:0% +and probably all of you run into that + + + align:start position:0% +and probably all of you run into that +problem + + align:start position:0% +problem + + + align:start position:0% +problem +i'm just being funny + + align:start position:0% +i'm just being funny + + + align:start position:0% +i'm just being funny +so but but i mean it is a real it is the + + align:start position:0% +so but but i mean it is a real it is the + + + align:start position:0% +so but but i mean it is a real it is the +program healthy problem is serious + + align:start position:0% +program healthy problem is serious + + + align:start position:0% +program healthy problem is serious +mathematical construct + + align:start position:0% +mathematical construct + + + align:start position:0% +mathematical construct +okay + + align:start position:0% +okay + + + align:start position:0% +okay +how + + align:start position:0% +how + + + align:start position:0% +how +um + + align:start position:0% +um + + + align:start position:0% +um +how do we deal with this how do we start + + align:start position:0% +how do we deal with this how do we start + + + align:start position:0% +how do we deal with this how do we start +thinking about um + + align:start position:0% +thinking about um + + + align:start position:0% +thinking about um +ways that we've dealt with it before in + + align:start position:0% +ways that we've dealt with it before in + + + align:start position:0% +ways that we've dealt with it before in +ways that biology could change the + + align:start position:0% +ways that biology could change the + + + align:start position:0% +ways that biology could change the +landscape a little bit + + align:start position:0% +landscape a little bit + + + align:start position:0% +landscape a little bit +uh + + align:start position:0% +uh + + + align:start position:0% +uh +usually you can what we do to when we're + + align:start position:0% +usually you can what we do to when we're + + + align:start position:0% +usually you can what we do to when we're +faced with an empty hard problem is uh + + align:start position:0% +faced with an empty hard problem is uh + + + align:start position:0% +faced with an empty hard problem is uh +cheat in some way or another you + + align:start position:0% +cheat in some way or another you + + + align:start position:0% +cheat in some way or another you +redefine the problem so it's in class p + + align:start position:0% +redefine the problem so it's in class p + + + align:start position:0% +redefine the problem so it's in class p +uh sometimes sacrificing something so + + align:start position:0% +uh sometimes sacrificing something so + + + align:start position:0% +uh sometimes sacrificing something so +you might have uh + + align:start position:0% +you might have uh + + + align:start position:0% +you might have uh +if you're interested in tertiary + + align:start position:0% +if you're interested in tertiary + + + align:start position:0% +if you're interested in tertiary +structure we made it redefine it as a + + align:start position:0% +structure we made it redefine it as a + + + align:start position:0% +structure we made it redefine it as a +secondary and we showed the secondary + + align:start position:0% +secondary and we showed the secondary + + + align:start position:0% +secondary and we showed the secondary +structure for + + align:start position:0% +structure for + + + align:start position:0% +structure for +uh rnas + + align:start position:0% +uh rnas + + + align:start position:0% +uh rnas +it can be solved with a dynamic + + align:start position:0% +it can be solved with a dynamic + + + align:start position:0% +it can be solved with a dynamic +programming algorithm with an n squared + + align:start position:0% +programming algorithm with an n squared + + + align:start position:0% +programming algorithm with an n squared +and or worse in the sixth algorithm + + align:start position:0% +and or worse in the sixth algorithm + + + align:start position:0% +and or worse in the sixth algorithm +whether that is as + + align:start position:0% +whether that is as + + + align:start position:0% +whether that is as +precise as the + + align:start position:0% +precise as the + + + align:start position:0% +precise as the +most precise tertiary structure that one + + align:start position:0% +most precise tertiary structure that one + + + align:start position:0% +most precise tertiary structure that one +could get given you know sort of + + align:start position:0% +could get given you know sort of + + + align:start position:0% +could get given you know sort of +infinite at exponential time is an open + + align:start position:0% +infinite at exponential time is an open + + + align:start position:0% +infinite at exponential time is an open +question + + align:start position:0% +question + + + align:start position:0% +question +probably not + + align:start position:0% + + + + align:start position:0% + +some you could + + align:start position:0% +some you could + + + align:start position:0% +some you could +if the pro if n is small enough we + + align:start position:0% +if the pro if n is small enough we + + + align:start position:0% +if the pro if n is small enough we +showed that exponential times can be + + align:start position:0% +showed that exponential times can be + + + align:start position:0% +showed that exponential times can be +reasonable + + align:start position:0% +reasonable + + + align:start position:0% +reasonable +and so you just do an exhaustive search + + align:start position:0% +and so you just do an exhaustive search + + + align:start position:0% +and so you just do an exhaustive search +or if you can't do that then then you + + align:start position:0% +or if you can't do that then then you + + + align:start position:0% +or if you can't do that then then you +use some clever heuristic way of pruning + + align:start position:0% +use some clever heuristic way of pruning + + + align:start position:0% +use some clever heuristic way of pruning +things + + align:start position:0% + + + + align:start position:0% + +and that's in a certain sense that's + + align:start position:0% +and that's in a certain sense that's + + + align:start position:0% +and that's in a certain sense that's +what most of the approximations are + + align:start position:0% +what most of the approximations are + + + align:start position:0% +what most of the approximations are +so what can biology do + + align:start position:0% +so what can biology do + + + align:start position:0% +so what can biology do +we'll talk about three examples in uh + + align:start position:0% +we'll talk about three examples in uh + + + align:start position:0% +we'll talk about three examples in uh +today one is dna computing one is + + align:start position:0% +today one is dna computing one is + + + align:start position:0% +today one is dna computing one is +genetic algorithms and neural networks + + align:start position:0% +genetic algorithms and neural networks + + + align:start position:0% +genetic algorithms and neural networks +the first one in a cert none of these + + align:start position:0% +the first one in a cert none of these + + + align:start position:0% +the first one in a cert none of these +really actually solve the problem + + align:start position:0% + + + + align:start position:0% + +the first one is a way of just obtaining + + align:start position:0% +the first one is a way of just obtaining + + + align:start position:0% +the first one is a way of just obtaining +a lot more wrong computing power + + align:start position:0% +a lot more wrong computing power + + + align:start position:0% +a lot more wrong computing power +i'll show you a quote where they say + + align:start position:0% +i'll show you a quote where they say + + + align:start position:0% +i'll show you a quote where they say +they've solved an np complete problem + + align:start position:0% +they've solved an np complete problem + + + align:start position:0% +they've solved an np complete problem +but it's in the same sense that you can + + align:start position:0% +but it's in the same sense that you can + + + align:start position:0% +but it's in the same sense that you can +solve any exponential problem by by + + align:start position:0% +solve any exponential problem by by + + + align:start position:0% +solve any exponential problem by by +force + + align:start position:0% +force + + + align:start position:0% +force +that's not really finessing it out of np + + align:start position:0% +that's not really finessing it out of np + + + align:start position:0% +that's not really finessing it out of np +into into p + + align:start position:0% +into into p + + + align:start position:0% +into into p +genetic algorithms and neural networks + + align:start position:0% +genetic algorithms and neural networks + + + align:start position:0% +genetic algorithms and neural networks +are definitely heuristics they're + + align:start position:0% +are definitely heuristics they're + + + align:start position:0% +are definitely heuristics they're +beautifully inspired by two of the + + align:start position:0% +beautifully inspired by two of the + + + align:start position:0% +beautifully inspired by two of the +greatest + + align:start position:0% +greatest + + + align:start position:0% +greatest +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +in the history of life + + align:start position:0% +in the history of life + + + align:start position:0% +in the history of life +on earth and that is evolution and um + + align:start position:0% +on earth and that is evolution and um + + + align:start position:0% +on earth and that is evolution and um +complex + + align:start position:0% +complex + + + align:start position:0% +complex +uh brain networks and we'll get and uh + + align:start position:0% +uh brain networks and we'll get and uh + + + align:start position:0% +uh brain networks and we'll get and uh +and so genetic algorithms is based on + + align:start position:0% +and so genetic algorithms is based on + + + align:start position:0% +and so genetic algorithms is based on +the adaptation that occurs + + align:start position:0% +the adaptation that occurs + + + align:start position:0% +the adaptation that occurs +during evolution and recombination and + + align:start position:0% +during evolution and recombination and + + + align:start position:0% +during evolution and recombination and +immunogenesis and neural network is also + + align:start position:0% +immunogenesis and neural network is also + + + align:start position:0% +immunogenesis and neural network is also +about adaptation but this is on sort of + + align:start position:0% +about adaptation but this is on sort of + + + align:start position:0% +about adaptation but this is on sort of +the time scale of learning + + align:start position:0% +the time scale of learning + + + align:start position:0% +the time scale of learning +so we'll first dedicate ourselves to + + align:start position:0% +so we'll first dedicate ourselves to + + + align:start position:0% +so we'll first dedicate ourselves to +molecular computing + + align:start position:0% +molecular computing + + + align:start position:0% +molecular computing +and uh associated just kind of put it in + + align:start position:0% +and uh associated just kind of put it in + + + align:start position:0% +and uh associated just kind of put it in +the context of nano computing in general + + align:start position:0% +the context of nano computing in general + + + align:start position:0% +the context of nano computing in general +and you can see all the issues in + + align:start position:0% +and you can see all the issues in + + + align:start position:0% +and you can see all the issues in +computing not just the uh the math + + align:start position:0% +computing not just the uh the math + + + align:start position:0% +computing not just the uh the math +module so all the steps + + align:start position:0% +module so all the steps + + + align:start position:0% +module so all the steps +are + + align:start position:0% +are + + + align:start position:0% +are +assembly of of the requisite hardware + + align:start position:0% +assembly of of the requisite hardware + + + align:start position:0% +assembly of of the requisite hardware +this is some kind of factory operation + + align:start position:0% +this is some kind of factory operation + + + align:start position:0% +this is some kind of factory operation +typically + + align:start position:0% +typically + + + align:start position:0% +typically +then there's some sort of input module + + align:start position:0% +then there's some sort of input module + + + align:start position:0% +then there's some sort of input module +some hardware and software that's + + align:start position:0% +some hardware and software that's + + + align:start position:0% +some hardware and software that's +required for getting the data in then + + align:start position:0% +required for getting the data in then + + + align:start position:0% +required for getting the data in then +there's some sort of memory + + align:start position:0% +there's some sort of memory + + + align:start position:0% +there's some sort of memory +and then there's a central processor + + align:start position:0% +and then there's a central processor + + + align:start position:0% +and then there's a central processor +might have + + align:start position:0% +might have + + + align:start position:0% +might have +math components and output this is sort + + align:start position:0% +math components and output this is sort + + + align:start position:0% +math components and output this is sort +of like from our first lecture + + align:start position:0% +of like from our first lecture + + + align:start position:0% +of like from our first lecture +assembly input memory process and output + + align:start position:0% +assembly input memory process and output + + + align:start position:0% +assembly input memory process and output +and what we want to do with biology is + + align:start position:0% +and what we want to do with biology is + + + align:start position:0% +and what we want to do with biology is +we want to harvest things uh from + + align:start position:0% +we want to harvest things uh from + + + align:start position:0% +we want to harvest things uh from +genomics and from just biological + + align:start position:0% +genomics and from just biological + + + align:start position:0% +genomics and from just biological +research in general to use design better + + align:start position:0% +research in general to use design better + + + align:start position:0% +research in general to use design better +computers either in silico or in in a + + align:start position:0% +computers either in silico or in in a + + + align:start position:0% +computers either in silico or in in a +biological biochemical sense and then + + align:start position:0% +biological biochemical sense and then + + + align:start position:0% +biological biochemical sense and then +harness evolution either to make devices + + align:start position:0% +harness evolution either to make devices + + + align:start position:0% +harness evolution either to make devices +or or as part of algorithm development + + align:start position:0% + + + + align:start position:0% + +you know we have uh + + align:start position:0% + + + + align:start position:0% + +different different people have + + align:start position:0% +different different people have + + + align:start position:0% +different different people have +different opinions about how much longer + + align:start position:0% +different opinions about how much longer + + + align:start position:0% +different opinions about how much longer +moore's law the scaling for + + align:start position:0% + + + + align:start position:0% + +large-scale integrated circuits or + + align:start position:0% +large-scale integrated circuits or + + + align:start position:0% +large-scale integrated circuits or +curse files version that goes back to + + align:start position:0% +curse files version that goes back to + + + align:start position:0% +curse files version that goes back to +1900 about doubling every two years + + align:start position:0% +1900 about doubling every two years + + + align:start position:0% +1900 about doubling every two years +of + + align:start position:0% +of + + + align:start position:0% +of +the ability to + + align:start position:0% +the ability to + + + align:start position:0% +the ability to +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +calculations per second per thousand + + align:start position:0% +calculations per second per thousand + + + align:start position:0% +calculations per second per thousand +dollars there might be another decade + + align:start position:0% +dollars there might be another decade + + + align:start position:0% +dollars there might be another decade +left in in the silicon + + align:start position:0% +left in in the silicon + + + align:start position:0% +left in in the silicon +uh large scale integrated circuit that's + + align:start position:0% +uh large scale integrated circuit that's + + + align:start position:0% +uh large scale integrated circuit that's +what some people say or maybe more maybe + + align:start position:0% +what some people say or maybe more maybe + + + align:start position:0% +what some people say or maybe more maybe +less + + align:start position:0% +less + + + align:start position:0% +less +um + + align:start position:0% +um + + + align:start position:0% +um +so there are three real options here for + + align:start position:0% +so there are three real options here for + + + align:start position:0% +so there are three real options here for +um + + align:start position:0% + + + + align:start position:0% + +that next step + + align:start position:0% +that next step + + + align:start position:0% +that next step +electro electronic + + align:start position:0% +electro electronic + + + align:start position:0% +electro electronic +uh + + align:start position:0% +uh + + + align:start position:0% +uh +nano computing optical nano computing + + align:start position:0% +nano computing optical nano computing + + + align:start position:0% +nano computing optical nano computing +molecular nano computing and you could + + align:start position:0% +molecular nano computing and you could + + + align:start position:0% +molecular nano computing and you could +add to this quantum computing for maybe + + align:start position:0% +add to this quantum computing for maybe + + + align:start position:0% +add to this quantum computing for maybe +four different options for beating + + align:start position:0% +four different options for beating + + + align:start position:0% +four different options for beating +moore's law or extending moore's law i + + align:start position:0% +moore's law or extending moore's law i + + + align:start position:0% +moore's law or extending moore's law i +think how you look at it + + align:start position:0% +think how you look at it + + + align:start position:0% +think how you look at it +so let's just walk through them quickly + + align:start position:0% +so let's just walk through them quickly + + + align:start position:0% +so let's just walk through them quickly +one at a time optical + + align:start position:0% +one at a time optical + + + align:start position:0% +one at a time optical +computing you can think of is already + + align:start position:0% +computing you can think of is already + + + align:start position:0% +computing you can think of is already +here in a sense in our optical fiber + + align:start position:0% +here in a sense in our optical fiber + + + align:start position:0% +here in a sense in our optical fiber +networks have very fast switches that + + align:start position:0% +networks have very fast switches that + + + align:start position:0% +networks have very fast switches that +are required + + align:start position:0% +are required + + + align:start position:0% +are required +for a good deal of our fastest internet + + align:start position:0% +for a good deal of our fastest internet + + + align:start position:0% +for a good deal of our fastest internet +and there in their various + + align:start position:0% +and there in their various + + + align:start position:0% +and there in their various +demonstrations where you can do optical + + align:start position:0% +demonstrations where you can do optical + + + align:start position:0% +demonstrations where you can do optical +computing + + align:start position:0% +computing + + + align:start position:0% +computing +for many of the tasks not just the data + + align:start position:0% +for many of the tasks not just the data + + + align:start position:0% +for many of the tasks not just the data +transfer + + align:start position:0% +transfer + + + align:start position:0% +transfer +and and and just like many other things + + align:start position:0% +and and and just like many other things + + + align:start position:0% +and and and just like many other things +there's a desire to shrink this down for + + align:start position:0% +there's a desire to shrink this down for + + + align:start position:0% +there's a desire to shrink this down for +cost of manufacturing and quality and so + + align:start position:0% +cost of manufacturing and quality and so + + + align:start position:0% +cost of manufacturing and quality and so +forth + + align:start position:0% +forth + + + align:start position:0% +forth +uh the advantages of the optical over um + + align:start position:0% +uh the advantages of the optical over um + + + align:start position:0% +uh the advantages of the optical over um +electronic typical computers is that + + align:start position:0% +electronic typical computers is that + + + align:start position:0% +electronic typical computers is that +they are + + align:start position:0% +they are + + + align:start position:0% +they are +they uh for a given set of operations + + align:start position:0% +they uh for a given set of operations + + + align:start position:0% +they uh for a given set of operations +there's the general sentiment then it + + align:start position:0% +there's the general sentiment then it + + + align:start position:0% +there's the general sentiment then it +might be lower heat generation + + align:start position:0% +might be lower heat generation + + + align:start position:0% +might be lower heat generation +it it goes at the speed of light + + align:start position:0% +it it goes at the speed of light + + + align:start position:0% +it it goes at the speed of light +rather than the slightly lower than + + align:start position:0% +rather than the slightly lower than + + + align:start position:0% +rather than the slightly lower than +speed of light that typically comes into + + align:start position:0% +speed of light that typically comes into + + + align:start position:0% +speed of light that typically comes into +actual implementations in electronic + + align:start position:0% +actual implementations in electronic + + + align:start position:0% +actual implementations in electronic +circuits + + align:start position:0% +circuits + + + align:start position:0% +circuits +and there here's two examples taken from + + align:start position:0% +and there here's two examples taken from + + + align:start position:0% +and there here's two examples taken from +the literature of getting + + align:start position:0% +the literature of getting + + + align:start position:0% +the literature of getting +natural sort of self-assembly just as + + align:start position:0% +natural sort of self-assembly just as + + + align:start position:0% +natural sort of self-assembly just as +we've seen in many biological systems we + + align:start position:0% +we've seen in many biological systems we + + + align:start position:0% +we've seen in many biological systems we +get self-assembly of membranes + + align:start position:0% +get self-assembly of membranes + + + align:start position:0% +get self-assembly of membranes +self-assembly of multi-protein complexes + + align:start position:0% +self-assembly of multi-protein complexes + + + align:start position:0% +self-assembly of multi-protein complexes +here you have you want to make + + align:start position:0% +here you have you want to make + + + align:start position:0% +here you have you want to make +a particular kind a size of uh + + align:start position:0% + + + + align:start position:0% + +optical of particles + + align:start position:0% +optical of particles + + + align:start position:0% +optical of particles +that have the right uh refractive index + + align:start position:0% +that have the right uh refractive index + + + align:start position:0% +that have the right uh refractive index +and spacing and shape and so forth and + + align:start position:0% +and spacing and shape and so forth and + + + align:start position:0% +and spacing and shape and so forth and +you can use self assembly here + + align:start position:0% +you can use self assembly here + + + align:start position:0% +you can use self assembly here +for that sort of thing + + align:start position:0% +for that sort of thing + + + align:start position:0% +for that sort of thing +that's this is these are examples of + + align:start position:0% +that's this is these are examples of + + + align:start position:0% +that's this is these are examples of +where we're getting sort of in a + + align:start position:0% +where we're getting sort of in a + + + align:start position:0% +where we're getting sort of in a +nanometer range here this is a five + + align:start position:0% +nanometer range here this is a five + + + align:start position:0% +nanometer range here this is a five +micron scale object here + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +i've chosen this particular example + + align:start position:0% +i've chosen this particular example + + + align:start position:0% +i've chosen this particular example +there are a number of uh examples of + + align:start position:0% +there are a number of uh examples of + + + align:start position:0% +there are a number of uh examples of +electronic + + align:start position:0% +electronic + + + align:start position:0% +electronic +nano computing where the electronics is + + align:start position:0% +nano computing where the electronics is + + + align:start position:0% +nano computing where the electronics is +getting down to the sort of size of + + align:start position:0% +getting down to the sort of size of + + + align:start position:0% +getting down to the sort of size of +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +here the molecule chosen + + align:start position:0% +here the molecule chosen + + + align:start position:0% +here the molecule chosen +is a polymer of carbon not a hydrocarbon + + align:start position:0% +is a polymer of carbon not a hydrocarbon + + + align:start position:0% +is a polymer of carbon not a hydrocarbon +but carbon + + align:start position:0% +but carbon + + + align:start position:0% +but carbon +it's like the buckyballs which is carbon + + align:start position:0% +it's like the buckyballs which is carbon + + + align:start position:0% +it's like the buckyballs which is carbon +60 or graphite rolled up in the tubes + + align:start position:0% +60 or graphite rolled up in the tubes + + + align:start position:0% +60 or graphite rolled up in the tubes +the nanotubes can be used as + + align:start position:0% +the nanotubes can be used as + + + align:start position:0% +the nanotubes can be used as +transistor-like elements in very tiny + + align:start position:0% +transistor-like elements in very tiny + + + align:start position:0% +transistor-like elements in very tiny +circuits + + align:start position:0% +circuits + + + align:start position:0% +circuits +um this is this is just a schematic this + + align:start position:0% +um this is this is just a schematic this + + + align:start position:0% +um this is this is just a schematic this +isn't actually a micrograph right and uh + + align:start position:0% +isn't actually a micrograph right and uh + + + align:start position:0% +isn't actually a micrograph right and uh +and here four circuits that kind of + + align:start position:0% +and here four circuits that kind of + + + align:start position:0% +and here four circuits that kind of +reflect what you might that might be + + align:start position:0% +reflect what you might that might be + + + align:start position:0% +reflect what you might that might be +your first four projects in a an + + align:start position:0% +your first four projects in a an + + + align:start position:0% +your first four projects in a an +introductory electronics course um + + align:start position:0% +introductory electronics course um + + + align:start position:0% +introductory electronics course um +ignoring the fact that you might not use + + align:start position:0% +ignoring the fact that you might not use + + + align:start position:0% +ignoring the fact that you might not use +nanotubes but you you would uh you would + + align:start position:0% +nanotubes but you you would uh you would + + + align:start position:0% +nanotubes but you you would uh you would +have voltage in and voltage out there + + align:start position:0% +have voltage in and voltage out there + + + align:start position:0% +have voltage in and voltage out there +was uh this is a transistor light + + align:start position:0% +was uh this is a transistor light + + + align:start position:0% +was uh this is a transistor light +circuit or an inverter like circuit in + + align:start position:0% +circuit or an inverter like circuit in + + + align:start position:0% +circuit or an inverter like circuit in +the upper left hand corner of slide 10. + + align:start position:0% +the upper left hand corner of slide 10. + + + align:start position:0% +the upper left hand corner of slide 10. +and the nano tube here is in the middle + + align:start position:0% +and the nano tube here is in the middle + + + align:start position:0% +and the nano tube here is in the middle +in in + + align:start position:0% +in in + + + align:start position:0% +in in +series with a resistor going from high + + align:start position:0% +series with a resistor going from high + + + align:start position:0% +series with a resistor going from high +voltage to the ground at the lower part + + align:start position:0% +voltage to the ground at the lower part + + + align:start position:0% +voltage to the ground at the lower part +and the voltage in + + align:start position:0% +and the voltage in + + + align:start position:0% +and the voltage in +essentially modulates the voltage out in + + align:start position:0% +essentially modulates the voltage out in + + + align:start position:0% +essentially modulates the voltage out in +the non-linear curve and you can see + + align:start position:0% +the non-linear curve and you can see + + + align:start position:0% +the non-linear curve and you can see +this highly cooperative + + align:start position:0% +this highly cooperative + + + align:start position:0% +this highly cooperative +curve just like the ones that we've been + + align:start position:0% +curve just like the ones that we've been + + + align:start position:0% +curve just like the ones that we've been +talking about in a number of other + + align:start position:0% +talking about in a number of other + + + align:start position:0% +talking about in a number of other +biological and physical systems + + align:start position:0% +biological and physical systems + + + align:start position:0% +biological and physical systems +uh the upper right you have a nor gate + + align:start position:0% +uh the upper right you have a nor gate + + + align:start position:0% +uh the upper right you have a nor gate +almost every circuit can be made by + + align:start position:0% +almost every circuit can be made by + + + align:start position:0% +almost every circuit can be made by +combination simply by + + align:start position:0% +combination simply by + + + align:start position:0% +combination simply by +uh + + align:start position:0% +uh + + + align:start position:0% +uh +not ores this is a this is an inverter + + align:start position:0% +not ores this is a this is an inverter + + + align:start position:0% +not ores this is a this is an inverter +and plus a an ore so you can see that + + align:start position:0% +and plus a an ore so you can see that + + + align:start position:0% +and plus a an ore so you can see that +there there now have two inputs + + align:start position:0% +there there now have two inputs + + + align:start position:0% +there there now have two inputs +on the left and right in one and two and + + align:start position:0% +on the left and right in one and two and + + + align:start position:0% +on the left and right in one and two and +they can have states one one one zero + + align:start position:0% +they can have states one one one zero + + + align:start position:0% +they can have states one one one zero +zero one zero zero going from left to + + align:start position:0% +zero one zero zero going from left to + + + align:start position:0% +zero one zero zero going from left to +right and you can see only the in when + + align:start position:0% +right and you can see only the in when + + + align:start position:0% +right and you can see only the in when +they're both zero does the whole circuit + + align:start position:0% +they're both zero does the whole circuit + + + align:start position:0% +they're both zero does the whole circuit +down go output go down to zero or low + + align:start position:0% +down go output go down to zero or low + + + align:start position:0% +down go output go down to zero or low +voltage for output so input + + align:start position:0% +voltage for output so input + + + align:start position:0% +voltage for output so input +if there are three possible input + + align:start position:0% +if there are three possible input + + + align:start position:0% +if there are three possible input +combinations and and the last one gets + + align:start position:0% +combinations and and the last one gets + + + align:start position:0% +combinations and and the last one gets +low and this is all done this is all + + align:start position:0% +low and this is all done this is all + + + align:start position:0% +low and this is all done this is all +done with these kind of molecular scale + + align:start position:0% +done with these kind of molecular scale + + + align:start position:0% +done with these kind of molecular scale +nano + + align:start position:0% +nano + + + align:start position:0% +nano +tubes + + align:start position:0% +tubes + + + align:start position:0% +tubes +uh here's a ram and virus two nanotubes + + align:start position:0% +uh here's a ram and virus two nanotubes + + + align:start position:0% +uh here's a ram and virus two nanotubes +in order to store where it's either + + align:start position:0% +in order to store where it's either + + + align:start position:0% +in order to store where it's either +where you flip it from from open to to + + align:start position:0% +where you flip it from from open to to + + + align:start position:0% +where you flip it from from open to to +flip it from low to to high + + align:start position:0% +flip it from low to to high + + + align:start position:0% +flip it from low to to high +in the last example the lower right you + + align:start position:0% +in the last example the lower right you + + + align:start position:0% +in the last example the lower right you +now need three nanotubes you see we + + align:start position:0% +now need three nanotubes you see we + + + align:start position:0% +now need three nanotubes you see we +worked our way up in complexity from one + + align:start position:0% +worked our way up in complexity from one + + + align:start position:0% +worked our way up in complexity from one +to two to three and you need three in + + align:start position:0% +to two to three and you need three in + + + align:start position:0% +to two to three and you need three in +order to get a ring oscillator used i + + align:start position:0% +order to get a ring oscillator used i + + + align:start position:0% +order to get a ring oscillator used i +mean that's the way you would think + + align:start position:0% +mean that's the way you would think + + + align:start position:0% +mean that's the way you would think +about + + align:start position:0% +about + + + align:start position:0% +about +most easily think about it where you + + align:start position:0% +most easily think about it where you + + + align:start position:0% +most easily think about it where you +have the first one's output uh + + align:start position:0% +have the first one's output uh + + + align:start position:0% +have the first one's output uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +affecting the second one the second one + + align:start position:0% +affecting the second one the second one + + + align:start position:0% +affecting the second one the second one +affected the third and third one looping + + align:start position:0% +affected the third and third one looping + + + align:start position:0% +affected the third and third one looping +back to the first and the result of this + + align:start position:0% +back to the first and the result of this + + + align:start position:0% +back to the first and the result of this +is you get a series + + align:start position:0% +is you get a series + + + align:start position:0% +is you get a series +of uh peaks and troughs here which you + + align:start position:0% +of uh peaks and troughs here which you + + + align:start position:0% +of uh peaks and troughs here which you +use for synchronizing circuits or + + align:start position:0% +use for synchronizing circuits or + + + align:start position:0% +use for synchronizing circuits or +generating other useful sinusoidal + + align:start position:0% +generating other useful sinusoidal + + + align:start position:0% +generating other useful sinusoidal +processes + + align:start position:0% +processes + + + align:start position:0% +processes +now that's + + align:start position:0% + + + + align:start position:0% + +one example of sort of optical + + align:start position:0% +one example of sort of optical + + + align:start position:0% +one example of sort of optical +electronic molecular includes a number + + align:start position:0% +electronic molecular includes a number + + + align:start position:0% +electronic molecular includes a number +of different possibilities including dna + + align:start position:0% +of different possibilities including dna + + + align:start position:0% +of different possibilities including dna +which is what will focus on dna + + align:start position:0% +which is what will focus on dna + + + align:start position:0% +which is what will focus on dna +computing and this was started by a + + align:start position:0% +computing and this was started by a + + + align:start position:0% +computing and this was started by a +person a physicist famous for thinking + + align:start position:0% +person a physicist famous for thinking + + + align:start position:0% +person a physicist famous for thinking +out of the box quite a bit uh feynman in + + align:start position:0% +out of the box quite a bit uh feynman in + + + align:start position:0% +out of the box quite a bit uh feynman in +1959 when he was still fairly young + + align:start position:0% +1959 when he was still fairly young + + + align:start position:0% +1959 when he was still fairly young +gave a + + align:start position:0% +gave a + + + align:start position:0% +gave a +talk entitled there's plenty of room at + + align:start position:0% +talk entitled there's plenty of room at + + + align:start position:0% +talk entitled there's plenty of room at +the bottom + + align:start position:0% +the bottom + + + align:start position:0% +the bottom +and by that he meant + + align:start position:0% +and by that he meant + + + align:start position:0% +and by that he meant +that we can just as we can + + align:start position:0% +that we can just as we can + + + align:start position:0% +that we can just as we can +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +machine and manufacture + + align:start position:0% +machine and manufacture + + + align:start position:0% +machine and manufacture +objects uh under + + align:start position:0% +objects uh under + + + align:start position:0% +objects uh under +fairly automated fashion we should be + + align:start position:0% +fairly automated fashion we should be + + + align:start position:0% +fairly automated fashion we should be +able to scale that down + + align:start position:0% +able to scale that down + + + align:start position:0% +able to scale that down +to the point where we're manipulating + + align:start position:0% +to the point where we're manipulating + + + align:start position:0% +to the point where we're manipulating +individual atoms and he couldn't think + + align:start position:0% +individual atoms and he couldn't think + + + align:start position:0% +individual atoms and he couldn't think +of any + + align:start position:0% +of any + + + align:start position:0% +of any +physical reason + + align:start position:0% +physical reason + + + align:start position:0% +physical reason +such as the uncertainty principle or + + align:start position:0% +such as the uncertainty principle or + + + align:start position:0% +such as the uncertainty principle or +anything like that that would prevent + + align:start position:0% +anything like that that would prevent + + + align:start position:0% +anything like that that would prevent +one from doing that manipulating + + align:start position:0% +one from doing that manipulating + + + align:start position:0% +one from doing that manipulating +individual atoms and many years later + + align:start position:0% +individual atoms and many years later + + + align:start position:0% +individual atoms and many years later +now he's been proven right and that we + + align:start position:0% +now he's been proven right and that we + + + align:start position:0% +now he's been proven right and that we +are doing that albeit not in any really + + align:start position:0% +are doing that albeit not in any really + + + align:start position:0% +are doing that albeit not in any really +high production method + + align:start position:0% +high production method + + + align:start position:0% +high production method +drexler in his thesis and subsequently + + align:start position:0% +drexler in his thesis and subsequently + + + align:start position:0% +drexler in his thesis and subsequently +has championed uh is probably the right + + align:start position:0% +has championed uh is probably the right + + + align:start position:0% +has championed uh is probably the right +word uh this sort of notion and then and + + align:start position:0% +word uh this sort of notion and then and + + + align:start position:0% +word uh this sort of notion and then and +giving it the name nanotechnology + + align:start position:0% +giving it the name nanotechnology + + + align:start position:0% +giving it the name nanotechnology +nanosystems + + align:start position:0% +nanosystems + + + align:start position:0% +nanosystems +and and really fleshed out some of the + + align:start position:0% +and and really fleshed out some of the + + + align:start position:0% +and and really fleshed out some of the +things that one might be able to do if + + align:start position:0% +things that one might be able to do if + + + align:start position:0% +things that one might be able to do if +you had a much + + align:start position:0% +you had a much + + + align:start position:0% +you had a much +higher throughput way of dealing with + + align:start position:0% +higher throughput way of dealing with + + + align:start position:0% +higher throughput way of dealing with +manufacturing an atomic scale + + align:start position:0% +manufacturing an atomic scale + + + align:start position:0% +manufacturing an atomic scale +however even he did not + + align:start position:0% +however even he did not + + + align:start position:0% +however even he did not +really connect all the dots between + + align:start position:0% +really connect all the dots between + + + align:start position:0% +really connect all the dots between +where we are now and where we and how we + + align:start position:0% +where we are now and where we and how we + + + align:start position:0% +where we are now and where we and how we +get to the very first nano assemblers + + align:start position:0% +get to the very first nano assemblers + + + align:start position:0% +get to the very first nano assemblers +and nano technology + + align:start position:0% +and nano technology + + + align:start position:0% +and nano technology +um since then there's been kind of a + + align:start position:0% +um since then there's been kind of a + + + align:start position:0% +um since then there's been kind of a +renaissance of interest in this um with + + align:start position:0% +renaissance of interest in this um with + + + align:start position:0% +renaissance of interest in this um with +the recognition that biological systems + + align:start position:0% +the recognition that biological systems + + + align:start position:0% +the recognition that biological systems +actually are sort of naturally doing + + align:start position:0% +actually are sort of naturally doing + + + align:start position:0% +actually are sort of naturally doing +nanotech now tech scale atomic + + align:start position:0% +nanotech now tech scale atomic + + + align:start position:0% +nanotech now tech scale atomic +manipulations + + align:start position:0% +manipulations + + + align:start position:0% +manipulations +and you've seen a few examples that in + + align:start position:0% +and you've seen a few examples that in + + + align:start position:0% +and you've seen a few examples that in +this course + + align:start position:0% +this course + + + align:start position:0% +this course +also you know + + align:start position:0% + + + + align:start position:0% + +but the particular instance that we'll + + align:start position:0% +but the particular instance that we'll + + + align:start position:0% +but the particular instance that we'll +use as a jumping off point + + align:start position:0% +use as a jumping off point + + + align:start position:0% +use as a jumping off point +for discussion of all the steps that + + align:start position:0% +for discussion of all the steps that + + + align:start position:0% +for discussion of all the steps that +could be where biology and molecular + + align:start position:0% +could be where biology and molecular + + + align:start position:0% +could be where biology and molecular +mining could give us + + align:start position:0% +mining could give us + + + align:start position:0% +mining could give us +new tools + + align:start position:0% +new tools + + + align:start position:0% +new tools +whether it's from + + align:start position:0% +whether it's from + + + align:start position:0% +whether it's from +assembly + + align:start position:0% +assembly + + + align:start position:0% +assembly +input + + align:start position:0% +input + + + align:start position:0% +input +memory + + align:start position:0% +memory + + + align:start position:0% +memory +computation output + + align:start position:0% +computation output + + + align:start position:0% +computation output +we'll start with + + align:start position:0% +we'll start with + + + align:start position:0% +we'll start with +lynn adelman's + + align:start position:0% + + + + align:start position:0% + +paste changing paper in 1994 this this + + align:start position:0% +paste changing paper in 1994 this this + + + align:start position:0% +paste changing paper in 1994 this this +is the a of the rsa that that + + align:start position:0% +is the a of the rsa that that + + + align:start position:0% +is the a of the rsa that that +we talked about just a few minutes ago + + align:start position:0% +we talked about just a few minutes ago + + + align:start position:0% +we talked about just a few minutes ago +um + + align:start position:0% +um + + + align:start position:0% +um +he was obviously a hardcore + + align:start position:0% +he was obviously a hardcore + + + align:start position:0% +he was obviously a hardcore +and is uh algorithmics + + align:start position:0% +and is uh algorithmics + + + align:start position:0% +and is uh algorithmics +expert + + align:start position:0% +expert + + + align:start position:0% +expert +and decided in 1994 + + align:start position:0% +and decided in 1994 + + + align:start position:0% +and decided in 1994 +to + + align:start position:0% +to + + + align:start position:0% +to +um + + align:start position:0% +um + + + align:start position:0% +um +to actually do a paper that required not + + align:start position:0% +to actually do a paper that required not + + + align:start position:0% +to actually do a paper that required not +only algorithmics but a huge change in + + align:start position:0% +only algorithmics but a huge change in + + + align:start position:0% +only algorithmics but a huge change in +the way you implemented the algorithms + + align:start position:0% +the way you implemented the algorithms + + + align:start position:0% +the way you implemented the algorithms +and then actually to go into the lab + + align:start position:0% +and then actually to go into the lab + + + align:start position:0% +and then actually to go into the lab +into a biochemical laboratory which he + + align:start position:0% +into a biochemical laboratory which he + + + align:start position:0% +into a biochemical laboratory which he +was not + + align:start position:0% +was not + + + align:start position:0% +was not +previously + + align:start position:0% +previously + + + align:start position:0% +previously +trained + + align:start position:0% +trained + + + align:start position:0% +trained +and to to author it's a single author + + align:start position:0% +and to to author it's a single author + + + align:start position:0% +and to to author it's a single author +paper that included such things as pcr + + align:start position:0% +paper that included such things as pcr + + + align:start position:0% +paper that included such things as pcr +as in 1994 there was no literature on + + align:start position:0% +as in 1994 there was no literature on + + + align:start position:0% +as in 1994 there was no literature on +the subject of dna + + align:start position:0% +the subject of dna + + + align:start position:0% +the subject of dna +computers before that a mere six years + + align:start position:0% +computers before that a mere six years + + + align:start position:0% +computers before that a mere six years +later there were 520 references on the + + align:start position:0% +later there were 520 references on the + + + align:start position:0% +later there were 520 references on the +subject so he obviously hit some kind of + + align:start position:0% +subject so he obviously hit some kind of + + + align:start position:0% +subject so he obviously hit some kind of +nerve + + align:start position:0% +nerve + + + align:start position:0% +nerve +uh + + align:start position:0% +uh + + + align:start position:0% +uh +first few years of that after that were + + align:start position:0% +first few years of that after that were + + + align:start position:0% +first few years of that after that were +mainly theoretical but i'll show you + + align:start position:0% +mainly theoretical but i'll show you + + + align:start position:0% +mainly theoretical but i'll show you +some example but his paper was was had + + align:start position:0% +some example but his paper was was had + + + align:start position:0% +some example but his paper was was had +an experimental component and some + + align:start position:0% +an experimental component and some + + + align:start position:0% +an experimental component and some +others that i'll show you + + align:start position:0% +others that i'll show you + + + align:start position:0% +others that i'll show you +since this course is really about that + + align:start position:0% +since this course is really about that + + + align:start position:0% +since this course is really about that +interface constantly checking the theory + + align:start position:0% +interface constantly checking the theory + + + align:start position:0% +interface constantly checking the theory +with reality + + align:start position:0% +with reality + + + align:start position:0% +with reality +that's those are the ones that i'll + + align:start position:0% +that's those are the ones that i'll + + + align:start position:0% +that's those are the ones that i'll +emphasize here + + align:start position:0% +emphasize here + + + align:start position:0% +emphasize here +so the question that he asked in 1994 + + align:start position:0% +so the question that he asked in 1994 + + + align:start position:0% +so the question that he asked in 1994 +and is still fresh today is is there a + + align:start position:0% +and is still fresh today is is there a + + + align:start position:0% +and is still fresh today is is there a +hamiltonian path through all the nodes + + align:start position:0% +hamiltonian path through all the nodes + + + align:start position:0% +hamiltonian path through all the nodes +in a network so we've been talking about + + align:start position:0% +in a network so we've been talking about + + + align:start position:0% +in a network so we've been talking about +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +biological networks but here you know + + align:start position:0% +biological networks but here you know + + + align:start position:0% +biological networks but here you know +just in any network where the black + + align:start position:0% +just in any network where the black + + + align:start position:0% +just in any network where the black +nodes are connected by directed + + align:start position:0% +nodes are connected by directed + + + align:start position:0% +nodes are connected by directed +uh edges in this directed graph you want + + align:start position:0% +uh edges in this directed graph you want + + + align:start position:0% +uh edges in this directed graph you want +to go from the start s to the terminus t + + align:start position:0% +to go from the start s to the terminus t + + + align:start position:0% +to go from the start s to the terminus t +from 1 to 6 + + align:start position:0% +from 1 to 6 + + + align:start position:0% +from 1 to 6 +obeying the arrows and going through + + align:start position:0% +obeying the arrows and going through + + + align:start position:0% +obeying the arrows and going through +every point once + + align:start position:0% +every point once + + + align:start position:0% +every point once +how do you do this + + align:start position:0% +how do you do this + + + align:start position:0% +how do you do this +and how do you do it in dna + + align:start position:0% +and how do you do it in dna + + + align:start position:0% +and how do you do it in dna +so an example of one here is going from + + align:start position:0% +so an example of one here is going from + + + align:start position:0% +so an example of one here is going from +s to three to five to two to the fourth + + align:start position:0% +s to three to five to two to the fourth + + + align:start position:0% +s to three to five to two to the fourth +to t + + align:start position:0% +to t + + + align:start position:0% +to t +okay so the way you do it + + align:start position:0% +okay so the way you do it + + + align:start position:0% +okay so the way you do it +first uh in broad strokes you encode the + + align:start position:0% +first uh in broad strokes you encode the + + + align:start position:0% +first uh in broad strokes you encode the +graph + + align:start position:0% +graph + + + align:start position:0% +graph +both the nodes + + align:start position:0% +both the nodes + + + align:start position:0% +both the nodes +black spots and the edges into single + + align:start position:0% +black spots and the edges into single + + + align:start position:0% +black spots and the edges into single +stranded dna sequences + + align:start position:0% +stranded dna sequences + + + align:start position:0% +stranded dna sequences +then you create all possible paths + + align:start position:0% +then you create all possible paths + + + align:start position:0% +then you create all possible paths +as by using overlapping sequences to + + align:start position:0% +as by using overlapping sequences to + + + align:start position:0% +as by using overlapping sequences to +indicate which node is connected to + + align:start position:0% +indicate which node is connected to + + + align:start position:0% +indicate which node is connected to +which + + align:start position:0% +which + + + align:start position:0% +which +other node by what by an edge in which + + align:start position:0% +other node by what by an edge in which + + + align:start position:0% +other node by what by an edge in which +direction so you can actually have + + align:start position:0% +direction so you can actually have + + + align:start position:0% +direction so you can actually have +directionality just + + align:start position:0% +directionality just + + + align:start position:0% +directionality just +because you know dna has directionality + + align:start position:0% +because you know dna has directionality + + + align:start position:0% +because you know dna has directionality +and you use dna hybridization now to do + + align:start position:0% +and you use dna hybridization now to do + + + align:start position:0% +and you use dna hybridization now to do +that step + + align:start position:0% +that step + + + align:start position:0% +that step +now the first step is linear encoding + + align:start position:0% +now the first step is linear encoding + + + align:start position:0% +now the first step is linear encoding +the graph is linear with the number of + + align:start position:0% +the graph is linear with the number of + + + align:start position:0% +the graph is linear with the number of +points in the graph the number of places + + align:start position:0% +points in the graph the number of places + + + align:start position:0% +points in the graph the number of places +in the hamiltonian path + + align:start position:0% + + + + align:start position:0% + +the second step is not something and + + align:start position:0% +the second step is not something and + + + align:start position:0% +the second step is not something and +that you would do by having your + + align:start position:0% +that you would do by having your + + + align:start position:0% +that you would do by having your +computer program a dna synthesizer which + + align:start position:0% +computer program a dna synthesizer which + + + align:start position:0% +computer program a dna synthesizer which +is an automated machine that we've + + align:start position:0% +is an automated machine that we've + + + align:start position:0% +is an automated machine that we've +described + + align:start position:0% +described + + + align:start position:0% +described +a couple times + + align:start position:0% +a couple times + + + align:start position:0% +a couple times +the second step is + + align:start position:0% +the second step is + + + align:start position:0% +the second step is +is out of your hands this is something + + align:start position:0% +is out of your hands this is something + + + align:start position:0% +is out of your hands this is something +that's uh + + align:start position:0% +that's uh + + + align:start position:0% +that's uh +that + + align:start position:0% +that + + + align:start position:0% +that +that happens automatically when you put + + align:start position:0% +that happens automatically when you put + + + align:start position:0% +that happens automatically when you put +dna in the solution if you design these + + align:start position:0% +dna in the solution if you design these + + + align:start position:0% +dna in the solution if you design these +sequences carefully so they don't cross + + align:start position:0% +sequences carefully so they don't cross + + + align:start position:0% +sequences carefully so they don't cross +hybridize very much then the only way + + align:start position:0% +hybridize very much then the only way + + + align:start position:0% +hybridize very much then the only way +they can assemble is the way you want it + + align:start position:0% +they can assemble is the way you want it + + + align:start position:0% +they can assemble is the way you want it +and then you then finally determine + + align:start position:0% +and then you then finally determine + + + align:start position:0% +and then you then finally determine +whether solution exists and this is + + align:start position:0% +whether solution exists and this is + + + align:start position:0% +whether solution exists and this is +something which is almost constant + + align:start position:0% +something which is almost constant + + + align:start position:0% +something which is almost constant +in + + align:start position:0% +in + + + align:start position:0% +in +complexity so the entire thing scales + + align:start position:0% +complexity so the entire thing scales + + + align:start position:0% +complexity so the entire thing scales +very gracefully + + align:start position:0% +very gracefully + + + align:start position:0% +very gracefully +instead of scaling + + align:start position:0% +instead of scaling + + + align:start position:0% +instead of scaling +exponentially as the hamiltonian path + + align:start position:0% +exponentially as the hamiltonian path + + + align:start position:0% +exponentially as the hamiltonian path +problem normally would this gives the + + align:start position:0% +problem normally would this gives the + + + align:start position:0% +problem normally would this gives the +appearance of a scaling + + align:start position:0% +appearance of a scaling + + + align:start position:0% +appearance of a scaling +linearly in time which is really + + align:start position:0% +linearly in time which is really + + + align:start position:0% +linearly in time which is really +one of the best case scenarios for + + align:start position:0% +one of the best case scenarios for + + + align:start position:0% +one of the best case scenarios for +polynomial time and certainly better + + align:start position:0% +polynomial time and certainly better + + + align:start position:0% +polynomial time and certainly better +than exponential + + align:start position:0% +than exponential + + + align:start position:0% +than exponential +so how do we actually do those broad + + align:start position:0% +so how do we actually do those broad + + + align:start position:0% +so how do we actually do those broad +strokes this is a more detailed view and + + align:start position:0% +strokes this is a more detailed view and + + + align:start position:0% +strokes this is a more detailed view and +you can see how this really seems like + + align:start position:0% +you can see how this really seems like + + + align:start position:0% +you can see how this really seems like +it's going to work you have + + align:start position:0% +it's going to work you have + + + align:start position:0% +it's going to work you have +each of the nodes + + align:start position:0% +each of the nodes + + + align:start position:0% +each of the nodes +encoded by sequences + + align:start position:0% +encoded by sequences + + + align:start position:0% +encoded by sequences +let's say the red + + align:start position:0% +let's say the red + + + align:start position:0% +let's say the red +and tan here on the top left of slide 14 + + align:start position:0% +and tan here on the top left of slide 14 + + + align:start position:0% +and tan here on the top left of slide 14 +and you have + + align:start position:0% +and you have + + + align:start position:0% +and you have +if you want to connect node three + + align:start position:0% +if you want to connect node three + + + align:start position:0% +if you want to connect node three +with node four so that + + align:start position:0% +with node four so that + + + align:start position:0% +with node four so that +you take the right hand end the three + + align:start position:0% +you take the right hand end the three + + + align:start position:0% +you take the right hand end the three +prime ends which is sort of greenish can + + align:start position:0% +prime ends which is sort of greenish can + + + align:start position:0% +prime ends which is sort of greenish can +and you connect it now to the + + align:start position:0% +and you connect it now to the + + + align:start position:0% +and you connect it now to the +other end of uh that is to say the five + + align:start position:0% +other end of uh that is to say the five + + + align:start position:0% +other end of uh that is to say the five +prime end of node four just below it + + align:start position:0% +prime end of node four just below it + + + align:start position:0% +prime end of node four just below it +which is blue so now you have this + + align:start position:0% +which is blue so now you have this + + + align:start position:0% +which is blue so now you have this +hybrid um + + align:start position:0% +hybrid um + + + align:start position:0% +hybrid um +which is ordered so it has so it's an + + align:start position:0% +which is ordered so it has so it's an + + + align:start position:0% +which is ordered so it has so it's an +arrow going from three to four + + align:start position:0% +arrow going from three to four + + + align:start position:0% +arrow going from three to four +and um and that edge has this particular + + align:start position:0% +and um and that edge has this particular + + + align:start position:0% +and um and that edge has this particular +sequence going from 5 prime to 3 prime + + align:start position:0% +sequence going from 5 prime to 3 prime + + + align:start position:0% +sequence going from 5 prime to 3 prime +now in practice you want the edges to be + + align:start position:0% +now in practice you want the edges to be + + + align:start position:0% +now in practice you want the edges to be +complementary not identical to the nodes + + align:start position:0% +complementary not identical to the nodes + + + align:start position:0% +complementary not identical to the nodes +and so all the nodes are actually + + align:start position:0% +and so all the nodes are actually + + + align:start position:0% +and so all the nodes are actually +represented as reverse sequences um in + + align:start position:0% +represented as reverse sequences um in + + + align:start position:0% +represented as reverse sequences um in +the lower left-hand part of + + align:start position:0% +the lower left-hand part of + + + align:start position:0% +the lower left-hand part of +slide 14. and so represent all the + + align:start position:0% +slide 14. and so represent all the + + + align:start position:0% +slide 14. and so represent all the +edges that connect nodes by the in this + + align:start position:0% +edges that connect nodes by the in this + + + align:start position:0% +edges that connect nodes by the in this +directional manner + + align:start position:0% +directional manner + + + align:start position:0% +directional manner +and then + + align:start position:0% +and then + + + align:start position:0% +and then +an example of + + align:start position:0% +an example of + + + align:start position:0% +an example of +how you would connect three nodes three + + align:start position:0% +how you would connect three nodes three + + + align:start position:0% +how you would connect three nodes three +to four to five + + align:start position:0% +to four to five + + + align:start position:0% +to four to five +by + + align:start position:0% +by + + + align:start position:0% +by +two connecting directional edges three + + align:start position:0% +two connecting directional edges three + + + align:start position:0% +two connecting directional edges three +four four five is shown here all the + + align:start position:0% +four four five is shown here all the + + + align:start position:0% +four four five is shown here all the +nodes are in reverse complements + + align:start position:0% +nodes are in reverse complements + + + align:start position:0% +nodes are in reverse complements +and all the edges + + align:start position:0% +and all the edges + + + align:start position:0% +and all the edges +are in the forward + + align:start position:0% +are in the forward + + + align:start position:0% +are in the forward +direction as arbitrarily defined here + + align:start position:0% +direction as arbitrarily defined here + + + align:start position:0% +direction as arbitrarily defined here +and you can see how these stitch these + + align:start position:0% +and you can see how these stitch these + + + align:start position:0% +and you can see how these stitch these +together and you make firm connections + + align:start position:0% +together and you make firm connections + + + align:start position:0% +together and you make firm connections +that are unambiguous not non-cross + + align:start position:0% +that are unambiguous not non-cross + + + align:start position:0% +that are unambiguous not non-cross +reacting + + align:start position:0% +reacting + + + align:start position:0% +reacting +and have a direct directionality + + align:start position:0% +and have a direct directionality + + + align:start position:0% +and have a direct directionality +now that + + align:start position:0% +now that + + + align:start position:0% +now that +you're starting to get the idea that now + + align:start position:0% +you're starting to get the idea that now + + + align:start position:0% +you're starting to get the idea that now +we can encode this in dna but how we're + + align:start position:0% +we can encode this in dna but how we're + + + align:start position:0% +we can encode this in dna but how we're +going to actually do the computation and + + align:start position:0% +going to actually do the computation and + + + align:start position:0% +going to actually do the computation and +how we're going to find out who the + + align:start position:0% +how we're going to find out who the + + + align:start position:0% +how we're going to find out who the +winner is + + align:start position:0% +winner is + + + align:start position:0% +winner is +so what what is done + + align:start position:0% +so what what is done + + + align:start position:0% +so what what is done +remember we want to create all the paths + + align:start position:0% +remember we want to create all the paths + + + align:start position:0% +remember we want to create all the paths +and then ask whether any of them go + + align:start position:0% +and then ask whether any of them go + + + align:start position:0% +and then ask whether any of them go +through all the points and then do any + + align:start position:0% +through all the points and then do any + + + align:start position:0% +through all the points and then do any +of them go through all the points + + align:start position:0% +of them go through all the points + + + align:start position:0% +of them go through all the points +exactly once so the first thing is to + + align:start position:0% +exactly once so the first thing is to + + + align:start position:0% +exactly once so the first thing is to +create all the paths from start to + + align:start position:0% +create all the paths from start to + + + align:start position:0% +create all the paths from start to +terminus and by and by just throwing in + + align:start position:0% +terminus and by and by just throwing in + + + align:start position:0% +terminus and by and by just throwing in +this mixture of all the all the edges + + align:start position:0% +this mixture of all the all the edges + + + align:start position:0% +this mixture of all the all the edges +and all the nodes you will create in + + align:start position:0% +and all the nodes you will create in + + + align:start position:0% +and all the nodes you will create in +principle all the paths now you want to + + align:start position:0% +principle all the paths now you want to + + + align:start position:0% +principle all the paths now you want to +right you will go from the prefix of one + + align:start position:0% +right you will go from the prefix of one + + + align:start position:0% +right you will go from the prefix of one +into the suffix the other + + align:start position:0% +into the suffix the other + + + align:start position:0% +into the suffix the other +in the same way that illustrated on the + + align:start position:0% +in the same way that illustrated on the + + + align:start position:0% +in the same way that illustrated on the +previous slide + + align:start position:0% +previous slide + + + align:start position:0% +previous slide +and here are some examples of some of + + align:start position:0% +and here are some examples of some of + + + align:start position:0% +and here are some examples of some of +the paths some are very short this only + + align:start position:0% +the paths some are very short this only + + + align:start position:0% +the paths some are very short this only +goes through four the one two four six + + align:start position:0% +goes through four the one two four six + + + align:start position:0% +goes through four the one two four six +uh only goes through four of the nodes + + align:start position:0% +uh only goes through four of the nodes + + + align:start position:0% +uh only goes through four of the nodes +that's not all six of them the bottom + + align:start position:0% +that's not all six of them the bottom + + + align:start position:0% +that's not all six of them the bottom +one goes through too many nodes and two + + align:start position:0% +one goes through too many nodes and two + + + align:start position:0% +one goes through too many nodes and two +minutes some of them it's going through + + align:start position:0% +minutes some of them it's going through + + + align:start position:0% +minutes some of them it's going through +repetitively + + align:start position:0% +repetitively + + + align:start position:0% +repetitively +but you get the idea is that you can + + align:start position:0% +but you get the idea is that you can + + + align:start position:0% +but you get the idea is that you can +define the path in terms of all these + + align:start position:0% +define the path in terms of all these + + + align:start position:0% +define the path in terms of all these +edges and the reverse complements which + + align:start position:0% +edges and the reverse complements which + + + align:start position:0% +edges and the reverse complements which +represent the nodes + + align:start position:0% +represent the nodes + + + align:start position:0% +represent the nodes +but here's the actual algorithm as + + align:start position:0% +but here's the actual algorithm as + + + align:start position:0% +but here's the actual algorithm as +encoded in dna + + align:start position:0% +encoded in dna + + + align:start position:0% +encoded in dna +and implemented by practical + + align:start position:0% +and implemented by practical + + + align:start position:0% +and implemented by practical +methods that a a computer scientist + + align:start position:0% +methods that a a computer scientist + + + align:start position:0% +methods that a a computer scientist +can do + + align:start position:0% +can do + + + align:start position:0% +can do +without too much help at least not + + align:start position:0% +without too much help at least not + + + align:start position:0% +without too much help at least not +enough help required for authorship + + align:start position:0% +enough help required for authorship + + + align:start position:0% +enough help required for authorship +so + + align:start position:0% +so + + + align:start position:0% +so +you and go we've already encoded the + + align:start position:0% +you and go we've already encoded the + + + align:start position:0% +you and go we've already encoded the +graph in the dna sequences + + align:start position:0% +graph in the dna sequences + + + align:start position:0% +graph in the dna sequences +and this is done by automated + + align:start position:0% +and this is done by automated + + + align:start position:0% +and this is done by automated +oligonucleotide synthesis you create all + + align:start position:0% +oligonucleotide synthesis you create all + + + align:start position:0% +oligonucleotide synthesis you create all +the paths from s to t by pcr amplifying + + align:start position:0% +the paths from s to t by pcr amplifying + + + align:start position:0% +the paths from s to t by pcr amplifying +from the s end of the oligo to the t end + + align:start position:0% +from the s end of the oligo to the t end + + + align:start position:0% +from the s end of the oligo to the t end +so that means the mere fact that they + + align:start position:0% +so that means the mere fact that they + + + align:start position:0% +so that means the mere fact that they +pcr amplify means they must contain node + + align:start position:0% +pcr amplify means they must contain node + + + align:start position:0% +pcr amplify means they must contain node +one and six the start and determinants + + align:start position:0% +one and six the start and determinants + + + align:start position:0% +one and six the start and determinants +so that's good + + align:start position:0% +so that's good + + + align:start position:0% +so that's good +now you wanna get the ones that visit + + align:start position:0% +now you wanna get the ones that visit + + + align:start position:0% +now you wanna get the ones that visit +every node so by serial hybridization + + align:start position:0% +every node so by serial hybridization + + + align:start position:0% +every node so by serial hybridization +you can have + + align:start position:0% +you can have + + + align:start position:0% +you can have +you can have those two three four and + + align:start position:0% +you can have those two three four and + + + align:start position:0% +you can have those two three four and +five immobilized and you bind the pcr + + align:start position:0% +five immobilized and you bind the pcr + + + align:start position:0% +five immobilized and you bind the pcr +products to it and then you'll lose from + + align:start position:0% +products to it and then you'll lose from + + + align:start position:0% +products to it and then you'll lose from +two and then in series you bind to three + + align:start position:0% +two and then in series you bind to three + + + align:start position:0% +two and then in series you bind to three +from three find it four loop four or + + align:start position:0% +from three find it four loop four or + + + align:start position:0% +from three find it four loop four or +five so now you know it has one and six + + align:start position:0% +five so now you know it has one and six + + + align:start position:0% +five so now you know it has one and six +because that's the pcr primers it has + + align:start position:0% +because that's the pcr primers it has + + + align:start position:0% +because that's the pcr primers it has +two three four and five because it + + align:start position:0% +two three four and five because it + + + align:start position:0% +two three four and five because it +balances them in series by hybridization + + align:start position:0% +balances them in series by hybridization + + + align:start position:0% +balances them in series by hybridization +then + + align:start position:0% +then + + + align:start position:0% +then +but that you could get some of those + + align:start position:0% +but that you could get some of those + + + align:start position:0% +but that you could get some of those +long + + align:start position:0% +long + + + align:start position:0% +long +uh + + align:start position:0% +uh + + + align:start position:0% +uh +paths that went through multiple those + + align:start position:0% +paths that went through multiple those + + + align:start position:0% +paths that went through multiple those +multiple times if you wanted to have + + align:start position:0% +multiple times if you wanted to have + + + align:start position:0% +multiple times if you wanted to have +exactly n nodes and what you do is some + + align:start position:0% +exactly n nodes and what you do is some + + + align:start position:0% +exactly n nodes and what you do is some +sort of electrophoretic sizing and + + align:start position:0% + + + + align:start position:0% + +and here if you have a calibration curve + + align:start position:0% +and here if you have a calibration curve + + + align:start position:0% +and here if you have a calibration curve +as shown at the bottom of slide 16 we + + align:start position:0% +as shown at the bottom of slide 16 we + + + align:start position:0% +as shown at the bottom of slide 16 we +have known dna size markers and no pcr + + align:start position:0% +have known dna size markers and no pcr + + + align:start position:0% +have known dna size markers and no pcr +products going um showing you have + + align:start position:0% +products going um showing you have + + + align:start position:0% +products going um showing you have +one of these dna + + align:start position:0% + + + + align:start position:0% + +nodes two three all the way up to six + + align:start position:0% +nodes two three all the way up to six + + + align:start position:0% +nodes two three all the way up to six +and if you find a solution that has all + + align:start position:0% +and if you find a solution that has all + + + align:start position:0% +and if you find a solution that has all +these properties pcrs does serial + + align:start position:0% +these properties pcrs does serial + + + align:start position:0% +these properties pcrs does serial +hybridization to all the nodes and is + + align:start position:0% +hybridization to all the nodes and is + + + align:start position:0% +hybridization to all the nodes and is +the right length such as the one + + align:start position:0% +the right length such as the one + + + align:start position:0% +the right length such as the one +in column six then you know you've got a + + align:start position:0% +in column six then you know you've got a + + + align:start position:0% +in column six then you know you've got a +solution + + align:start position:0% +solution + + + align:start position:0% +solution +and that was + + align:start position:0% +and that was + + + align:start position:0% +and that was +when edelman's argument that he had dna + + align:start position:0% +when edelman's argument that he had dna + + + align:start position:0% +when edelman's argument that he had dna +computing working + + align:start position:0% +computing working + + + align:start position:0% +computing working +six years later we now have or + + align:start position:0% +six years later we now have or + + + align:start position:0% +six years later we now have or +as of six years later there were now + + align:start position:0% +as of six years later there were now + + + align:start position:0% +as of six years later there were now +over 500 + + align:start position:0% +over 500 + + + align:start position:0% +over 500 +examples of this i'll show you + + align:start position:0% +examples of this i'll show you + + + align:start position:0% +examples of this i'll show you +this example + + align:start position:0% +this example + + + align:start position:0% +this example +as both as an introduction to the + + align:start position:0% +as both as an introduction to the + + + align:start position:0% +as both as an introduction to the +satisfiability problem and also as uh + + align:start position:0% +satisfiability problem and also as uh + + + align:start position:0% +satisfiability problem and also as uh +showing that you can do rna computing + + align:start position:0% +showing that you can do rna computing + + + align:start position:0% +showing that you can do rna computing +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and that you can encode two-dimensional + + align:start position:0% +and that you can encode two-dimensional + + + align:start position:0% +and that you can encode two-dimensional +objects and it illustrates a number of + + align:start position:0% +objects and it illustrates a number of + + + align:start position:0% +objects and it illustrates a number of +things the problem here is a chest + + align:start position:0% +things the problem here is a chest + + + align:start position:0% +things the problem here is a chest +problem very simple chess board it's not + + align:start position:0% +problem very simple chess board it's not + + + align:start position:0% +problem very simple chess board it's not +eight by eight but three by three as and + + align:start position:0% +eight by eight but three by three as and + + + align:start position:0% +eight by eight but three by three as and +the other and you've got an artifice + + align:start position:0% +the other and you've got an artifice + + + align:start position:0% +the other and you've got an artifice +you've got an artificial number of + + align:start position:0% +you've got an artificial number of + + + align:start position:0% +you've got an artificial number of +knights here and you those you know + + align:start position:0% +knights here and you those you know + + + align:start position:0% +knights here and you those you know +chess know that these knights can can + + align:start position:0% +chess know that these knights can can + + + align:start position:0% +chess know that these knights can can +attack in a curious combination of + + align:start position:0% +attack in a curious combination of + + + align:start position:0% +attack in a curious combination of +straight and diagonal it doesn't really + + align:start position:0% +straight and diagonal it doesn't really + + + align:start position:0% +straight and diagonal it doesn't really +matter the point is that this these are + + align:start position:0% +matter the point is that this these are + + + align:start position:0% +matter the point is that this these are +there are a variety of arrangements of + + align:start position:0% +there are a variety of arrangements of + + + align:start position:0% +there are a variety of arrangements of +of any number of knights such that none + + align:start position:0% +of any number of knights such that none + + + align:start position:0% +of any number of knights such that none +of them can attack each other and + + align:start position:0% +of them can attack each other and + + + align:start position:0% +of them can attack each other and +they're all kind of at peace here + + align:start position:0% +they're all kind of at peace here + + + align:start position:0% +they're all kind of at peace here +and the the object of this algorithm is + + align:start position:0% +and the the object of this algorithm is + + + align:start position:0% +and the the object of this algorithm is +to find those combinations and and + + align:start position:0% +to find those combinations and and + + + align:start position:0% +to find those combinations and and +here's uh and you do it by cloning so + + align:start position:0% +here's uh and you do it by cloning so + + + align:start position:0% +here's uh and you do it by cloning so +that was something that + + align:start position:0% +that was something that + + + align:start position:0% +that was something that +was not in the previous example by + + align:start position:0% +was not in the previous example by + + + align:start position:0% +was not in the previous example by +cloning you could find each of the + + align:start position:0% +cloning you could find each of the + + + align:start position:0% +cloning you could find each of the +solutions and you could then determine + + align:start position:0% +solutions and you could then determine + + + align:start position:0% +solutions and you could then determine +what is present in cis along that clones + + align:start position:0% +what is present in cis along that clones + + + align:start position:0% +what is present in cis along that clones +kind of like haplotyping or or splice + + align:start position:0% +kind of like haplotyping or or splice + + + align:start position:0% +kind of like haplotyping or or splice +form + + align:start position:0% +form + + + align:start position:0% +form +uh analysis you can really only analyze + + align:start position:0% +uh analysis you can really only analyze + + + align:start position:0% +uh analysis you can really only analyze +these things by looking at a single at + + align:start position:0% +these things by looking at a single at + + + align:start position:0% +these things by looking at a single at +the product of a single molecule and + + align:start position:0% +the product of a single molecule and + + + align:start position:0% +the product of a single molecule and +that's what cloning is about looking at + + align:start position:0% +that's what cloning is about looking at + + + align:start position:0% +that's what cloning is about looking at +amplifying that single molecule to the + + align:start position:0% +amplifying that single molecule to the + + + align:start position:0% +amplifying that single molecule to the +point where you can analyze it so that's + + align:start position:0% +point where you can analyze it so that's + + + align:start position:0% +point where you can analyze it so that's +one thing that's new the other thing is + + align:start position:0% +one thing that's new the other thing is + + + align:start position:0% +one thing that's new the other thing is +new is you start with + + align:start position:0% +new is you start with + + + align:start position:0% +new is you start with +with an rna + + align:start position:0% +with an rna + + + align:start position:0% +with an rna +in order that you can use this powerful + + align:start position:0% +in order that you can use this powerful + + + align:start position:0% +in order that you can use this powerful +method this enzyme called rna-h + + align:start position:0% +method this enzyme called rna-h + + + align:start position:0% +method this enzyme called rna-h +which will which has a property that + + align:start position:0% +which will which has a property that + + + align:start position:0% +which will which has a property that +when you bind a dna oligonucleotide + + align:start position:0% +when you bind a dna oligonucleotide + + + align:start position:0% +when you bind a dna oligonucleotide +to a + + align:start position:0% +to a + + + align:start position:0% +to a +to an rna and they're complementary + + align:start position:0% +to an rna and they're complementary + + + align:start position:0% +to an rna and they're complementary +rna-sh will destroy the rna at + + align:start position:0% +rna-sh will destroy the rna at + + + align:start position:0% +rna-sh will destroy the rna at +at that point at the point of + + align:start position:0% +at that point at the point of + + + align:start position:0% +at that point at the point of +hybridization so it's a way of + + align:start position:0% +hybridization so it's a way of + + + align:start position:0% +hybridization so it's a way of +eliminating an entire molecule + + align:start position:0% +eliminating an entire molecule + + + align:start position:0% +eliminating an entire molecule +if it happens to have a particular + + align:start position:0% +if it happens to have a particular + + + align:start position:0% +if it happens to have a particular +sequence in it and so one of the ways + + align:start position:0% +sequence in it and so one of the ways + + + align:start position:0% +sequence in it and so one of the ways +that you can + + align:start position:0% +that you can + + + align:start position:0% +that you can +ask logical questions about each + + align:start position:0% +ask logical questions about each + + + align:start position:0% +ask logical questions about each +molecule in a large complex mixture + + align:start position:0% +molecule in a large complex mixture + + + align:start position:0% +molecule in a large complex mixture +molecules is using this rna stage + + align:start position:0% +molecules is using this rna stage + + + align:start position:0% +molecules is using this rna stage +elimination + + align:start position:0% +elimination + + + align:start position:0% +elimination +and in a way it's a way of of having of + + align:start position:0% +and in a way it's a way of of having of + + + align:start position:0% +and in a way it's a way of of having of +designing an infinite number of + + align:start position:0% +designing an infinite number of + + + align:start position:0% +designing an infinite number of +restriction enzymes the the rnas plus + + align:start position:0% +restriction enzymes the the rnas plus + + + align:start position:0% +restriction enzymes the the rnas plus +the + + align:start position:0% +the + + + align:start position:0% +the +dna oligonucleotide provides in a + + align:start position:0% +dna oligonucleotide provides in a + + + align:start position:0% +dna oligonucleotide provides in a +certain sense a custom restriction + + align:start position:0% +certain sense a custom restriction + + + align:start position:0% +certain sense a custom restriction +enzyme + + align:start position:0% +enzyme + + + align:start position:0% +enzyme +any case the other thing that's unusual + + align:start position:0% +any case the other thing that's unusual + + + align:start position:0% +any case the other thing that's unusual +here is the idea of using split and pool + + align:start position:0% +here is the idea of using split and pool + + + align:start position:0% +here is the idea of using split and pool +or ligonite synthesis we introduced this + + align:start position:0% +or ligonite synthesis we introduced this + + + align:start position:0% +or ligonite synthesis we introduced this +in the in the lecture where we had we + + align:start position:0% +in the in the lecture where we had we + + + align:start position:0% +in the in the lecture where we had we +were introducing drug + + align:start position:0% + + + + align:start position:0% + +protein interaction and + + align:start position:0% +protein interaction and + + + align:start position:0% +protein interaction and +ways of synthesizing drugs and and other + + align:start position:0% +ways of synthesizing drugs and and other + + + align:start position:0% +ways of synthesizing drugs and and other +molecules by pool synthesis and the idea + + align:start position:0% +molecules by pool synthesis and the idea + + + align:start position:0% +molecules by pool synthesis and the idea +behind split pool synthesis in this case + + align:start position:0% +behind split pool synthesis in this case + + + align:start position:0% +behind split pool synthesis in this case +is that + + align:start position:0% +is that + + + align:start position:0% +is that +uh it for each of the + + align:start position:0% +uh it for each of the + + + align:start position:0% +uh it for each of the +each of the squares in this three by + + align:start position:0% +each of the squares in this three by + + + align:start position:0% +each of the squares in this three by +three matrix can have two states either + + align:start position:0% +three matrix can have two states either + + + align:start position:0% +three matrix can have two states either +has a knight or it doesn't each of those + + align:start position:0% +has a knight or it doesn't each of those + + + align:start position:0% +has a knight or it doesn't each of those +two states you can consider a zero or + + align:start position:0% +two states you can consider a zero or + + + align:start position:0% +two states you can consider a zero or +one you can represent them as two + + align:start position:0% +one you can represent them as two + + + align:start position:0% +one you can represent them as two +different sequences + + align:start position:0% +different sequences + + + align:start position:0% +different sequences +uh you know sequence a or c plus a prime + + align:start position:0% +uh you know sequence a or c plus a prime + + + align:start position:0% +uh you know sequence a or c plus a prime +representing presence or absence of + + align:start position:0% +representing presence or absence of + + + align:start position:0% +representing presence or absence of +something and so you basically have two + + align:start position:0% +something and so you basically have two + + + align:start position:0% +something and so you basically have two +to the uh + + align:start position:0% +to the uh + + + align:start position:0% +to the uh +you have nine squares since you have two + + align:start position:0% +you have nine squares since you have two + + + align:start position:0% +you have nine squares since you have two +to the ninth different possibilities and + + align:start position:0% +to the ninth different possibilities and + + + align:start position:0% +to the ninth different possibilities and +so down here below + + align:start position:0% +so down here below + + + align:start position:0% +so down here below +they synthesized + + align:start position:0% +they synthesized + + + align:start position:0% +they synthesized +a set of polymers where you have every + + align:start position:0% +a set of polymers where you have every + + + align:start position:0% +a set of polymers where you have every +possible binary state for this + + align:start position:0% +possible binary state for this + + + align:start position:0% +possible binary state for this +three by three grid + + align:start position:0% +three by three grid + + + align:start position:0% +three by three grid +and that's done by your synthesizing + + align:start position:0% +and that's done by your synthesizing + + + align:start position:0% +and that's done by your synthesizing +along and you come to where you're going + + align:start position:0% +along and you come to where you're going + + + align:start position:0% +along and you come to where you're going +to synthesize either a or a prime you + + align:start position:0% +to synthesize either a or a prime you + + + align:start position:0% +to synthesize either a or a prime you +split it + + align:start position:0% +split it + + + align:start position:0% +split it +half of this cool gets a half of it gets + + align:start position:0% +half of this cool gets a half of it gets + + + align:start position:0% +half of this cool gets a half of it gets +sequence a prime you pull them back + + align:start position:0% +sequence a prime you pull them back + + + align:start position:0% +sequence a prime you pull them back +together half gets b half gets b prime + + align:start position:0% +together half gets b half gets b prime + + + align:start position:0% +together half gets b half gets b prime +pull them and split them and c and c + + align:start position:0% +pull them and split them and c and c + + + align:start position:0% +pull them and split them and c and c +prime + + align:start position:0% +prime + + + align:start position:0% +prime +you really only need nine of these they + + align:start position:0% +you really only need nine of these they + + + align:start position:0% +you really only need nine of these they +did ten for some reason or other but the + + align:start position:0% +did ten for some reason or other but the + + + align:start position:0% +did ten for some reason or other but the +point is to get two to the ninth power + + align:start position:0% +point is to get two to the ninth power + + + align:start position:0% +point is to get two to the ninth power +um you need nine of these and then as + + align:start position:0% +um you need nine of these and then as + + + align:start position:0% +um you need nine of these and then as +you can uh then you can read them out + + align:start position:0% +you can uh then you can read them out + + + align:start position:0% +you can uh then you can read them out +electrophoretically just as the + + align:start position:0% +electrophoretically just as the + + + align:start position:0% +electrophoretically just as the +electrophoretic readout gave a sizing + + align:start position:0% +electrophoretic readout gave a sizing + + + align:start position:0% +electrophoretic readout gave a sizing +in the in the in the first dna computing + + align:start position:0% +in the in the in the first dna computing + + + align:start position:0% +in the in the in the first dna computing +you can use it to get the sizes of these + + align:start position:0% +you can use it to get the sizes of these + + + align:start position:0% +you can use it to get the sizes of these +and you can see you can read out this + + align:start position:0% +and you can see you can read out this + + + align:start position:0% +and you can see you can read out this +solute here's two solutions b e f h + + align:start position:0% +solute here's two solutions b e f h + + + align:start position:0% +solute here's two solutions b e f h +referring to the squares on the three by + + align:start position:0% +referring to the squares on the three by + + + align:start position:0% +referring to the squares on the three by +three did and efc these are both + + align:start position:0% +three did and efc these are both + + + align:start position:0% +three did and efc these are both +solutions bdfh um the way of reading + + align:start position:0% +solutions bdfh um the way of reading + + + align:start position:0% +solutions bdfh um the way of reading +this off this combinatorial synthesis + + align:start position:0% +this off this combinatorial synthesis + + + align:start position:0% +this off this combinatorial synthesis +from the bottom is you've got + + align:start position:0% +from the bottom is you've got + + + align:start position:0% +from the bottom is you've got +a through i as the possible bit binary + + align:start position:0% +a through i as the possible bit binary + + + align:start position:0% +a through i as the possible bit binary +signatures and then you have + + align:start position:0% +signatures and then you have + + + align:start position:0% +signatures and then you have +two columns either the zero column or + + align:start position:0% +two columns either the zero column or + + + align:start position:0% +two columns either the zero column or +the one the two states the two sequences + + align:start position:0% +the one the two states the two sequences + + + align:start position:0% +the one the two states the two sequences +and as you + + align:start position:0% +and as you + + + align:start position:0% +and as you +pcr from the end tag + + align:start position:0% +pcr from the end tag + + + align:start position:0% +pcr from the end tag +out to each of these tags a or a prime b + + align:start position:0% +out to each of these tags a or a prime b + + + align:start position:0% +out to each of these tags a or a prime b +or b prime and so forth then you get + + align:start position:0% +or b prime and so forth then you get + + + align:start position:0% +or b prime and so forth then you get +these are all uh you'll get this + + align:start position:0% +these are all uh you'll get this + + + align:start position:0% +these are all uh you'll get this +graduated series it'll tell you you've + + align:start position:0% +graduated series it'll tell you you've + + + align:start position:0% +graduated series it'll tell you you've +got a little you've got you've got + + align:start position:0% +got a little you've got you've got + + + align:start position:0% +got a little you've got you've got +a is in the zero state b is in the one + + align:start position:0% +a is in the zero state b is in the one + + + align:start position:0% +a is in the zero state b is in the one +state + + align:start position:0% +state + + + align:start position:0% +state +uh c and d are in the zero state + + align:start position:0% +uh c and d are in the zero state + + + align:start position:0% +uh c and d are in the zero state +e is in the one state so forth and so + + align:start position:0% +e is in the one state so forth and so + + + align:start position:0% +e is in the one state so forth and so +i've circle b being in the one state + + align:start position:0% +i've circle b being in the one state + + + align:start position:0% +i've circle b being in the one state +showing there's night in that position + + align:start position:0% +showing there's night in that position + + + align:start position:0% +showing there's night in that position +in position b + + align:start position:0% +in position b + + + align:start position:0% +in position b +and you can go through the same thing + + align:start position:0% +and you can go through the same thing + + + align:start position:0% +and you can go through the same thing +for the other solutions um each of these + + align:start position:0% +for the other solutions um each of these + + + align:start position:0% +for the other solutions um each of these +just + + align:start position:0% +just + + + align:start position:0% +just +developed as a clone and there's an and + + align:start position:0% +developed as a clone and there's an and + + + align:start position:0% +developed as a clone and there's an and +the neat thing about all these problems + + align:start position:0% +the neat thing about all these problems + + + align:start position:0% +the neat thing about all these problems +is they have multiple representations + + align:start position:0% +is they have multiple representations + + + align:start position:0% +is they have multiple representations +you represent them in dna your graphics + + align:start position:0% +you represent them in dna your graphics + + + align:start position:0% +you represent them in dna your graphics +in them and data you can represent them + + align:start position:0% +in them and data you can represent them + + + align:start position:0% +in them and data you can represent them +as a boolean logical set of operations + + align:start position:0% +as a boolean logical set of operations + + + align:start position:0% +as a boolean logical set of operations +where these things represent hands and + + align:start position:0% +where these things represent hands and + + + align:start position:0% +where these things represent hands and +ors + + align:start position:0% +ors + + + align:start position:0% +ors +at the bottom of the slide + + align:start position:0% +at the bottom of the slide + + + align:start position:0% +at the bottom of the slide +and so on and you will see that in in + + align:start position:0% +and so on and you will see that in in + + + align:start position:0% +and so on and you will see that in in +the last in the last uh examples where + + align:start position:0% +the last in the last uh examples where + + + align:start position:0% +the last in the last uh examples where +just kind of breeze through um + + align:start position:0% + + + + align:start position:0% + +where that that + + align:start position:0% +where that that + + + align:start position:0% +where that that +set of logical operations is probably + + align:start position:0% +set of logical operations is probably + + + align:start position:0% +set of logical operations is probably +one of the favorite + + align:start position:0% +one of the favorite + + + align:start position:0% +one of the favorite +points of attack for dna computing + + align:start position:0% +points of attack for dna computing + + + align:start position:0% +points of attack for dna computing +still today + + align:start position:0% +still today + + + align:start position:0% +still today +so what are the problems and advantages + + align:start position:0% +so what are the problems and advantages + + + align:start position:0% +so what are the problems and advantages +the problems are + + align:start position:0% +the problems are + + + align:start position:0% +the problems are +that yes it is polynomial time + + align:start position:0% +that yes it is polynomial time + + + align:start position:0% +that yes it is polynomial time +in fact it's close to linear time with a + + align:start position:0% +in fact it's close to linear time with a + + + align:start position:0% +in fact it's close to linear time with a +number of inputs in in terms of + + align:start position:0% +number of inputs in in terms of + + + align:start position:0% +number of inputs in in terms of +synthesis needs uh you you know your + + align:start position:0% +synthesis needs uh you you know your + + + align:start position:0% +synthesis needs uh you you know your +computer tells the synthesizer what to + + align:start position:0% +computer tells the synthesizer what to + + + align:start position:0% +computer tells the synthesizer what to +make and then uh enzymes will + + align:start position:0% +make and then uh enzymes will + + + align:start position:0% +make and then uh enzymes will +or hybridization will do we'll do this + + align:start position:0% +or hybridization will do we'll do this + + + align:start position:0% +or hybridization will do we'll do this +highly parallel reaction um independent + + align:start position:0% +highly parallel reaction um independent + + + align:start position:0% +highly parallel reaction um independent +of n so basically constant time + + align:start position:0% +of n so basically constant time + + + align:start position:0% +of n so basically constant time +so it's linear time for synthesis + + align:start position:0% +so it's linear time for synthesis + + + align:start position:0% +so it's linear time for synthesis +constant time for the computing and + + align:start position:0% +constant time for the computing and + + + align:start position:0% +constant time for the computing and +constant time for the + + align:start position:0% +constant time for the + + + align:start position:0% +constant time for the +getting the answer read out + + align:start position:0% +getting the answer read out + + + align:start position:0% +getting the answer read out +but you have exponential volumes for + + align:start position:0% +but you have exponential volumes for + + + align:start position:0% +but you have exponential volumes for +example a hundred node graph we've been + + align:start position:0% +example a hundred node graph we've been + + + align:start position:0% +example a hundred node graph we've been +talking about the various graph + + align:start position:0% +talking about the various graph + + + align:start position:0% +talking about the various graph +solutions + + align:start position:0% +solutions + + + align:start position:0% +solutions +might be + + align:start position:0% +might be + + + align:start position:0% +might be +10 to the 30th molecules and if any of + + align:start position:0% +10 to the 30th molecules and if any of + + + align:start position:0% +10 to the 30th molecules and if any of +you have + + align:start position:0% +you have + + + align:start position:0% +you have +ever tried to synthesize a mole or 10 to + + align:start position:0% +ever tried to synthesize a mole or 10 to + + + align:start position:0% +ever tried to synthesize a mole or 10 to +the 24th molecules you realize it would + + align:start position:0% +the 24th molecules you realize it would + + + align:start position:0% +the 24th molecules you realize it would +it would uh bankrupt our planet to make + + align:start position:0% +it would uh bankrupt our planet to make + + + align:start position:0% +it would uh bankrupt our planet to make +the 30th molecules + + align:start position:0% +the 30th molecules + + + align:start position:0% +the 30th molecules +so + + align:start position:0% +so + + + align:start position:0% +so +in addition the elementary steps are + + align:start position:0% +in addition the elementary steps are + + + align:start position:0% +in addition the elementary steps are +slow okay it's highly parallel + + align:start position:0% +slow okay it's highly parallel + + + align:start position:0% +slow okay it's highly parallel +you know you can imagine having + + align:start position:0% + + + + align:start position:0% + +trillions of molecules computing in + + align:start position:0% +trillions of molecules computing in + + + align:start position:0% +trillions of molecules computing in +parallel but the elementary steps of + + align:start position:0% +parallel but the elementary steps of + + + align:start position:0% +parallel but the elementary steps of +hybridization and dna polymerase or rna + + align:start position:0% +hybridization and dna polymerase or rna + + + align:start position:0% +hybridization and dna polymerase or rna +stage and support typically are in the + + align:start position:0% +stage and support typically are in the + + + align:start position:0% +stage and support typically are in the +millihertz range as to say you know it + + align:start position:0% +millihertz range as to say you know it + + + align:start position:0% +millihertz range as to say you know it +might take a thousand seconds rather + + align:start position:0% +might take a thousand seconds rather + + + align:start position:0% +might take a thousand seconds rather +than gigahertz which would be a + + align:start position:0% +than gigahertz which would be a + + + align:start position:0% +than gigahertz which would be a +billionth of a second so there might be + + align:start position:0% +billionth of a second so there might be + + + align:start position:0% +billionth of a second so there might be +a 10 to the 12th + + align:start position:0% +a 10 to the 12th + + + align:start position:0% +a 10 to the 12th +gap in rate of of executing the commands + + align:start position:0% +gap in rate of of executing the commands + + + align:start position:0% +gap in rate of of executing the commands +but there's more that the hope is + + align:start position:0% +but there's more that the hope is + + + align:start position:0% +but there's more that the hope is +there's more than a 10-12 advantage in + + align:start position:0% +there's more than a 10-12 advantage in + + + align:start position:0% +there's more than a 10-12 advantage in +parallelism + + align:start position:0% +parallelism + + + align:start position:0% +parallelism +in addition experimental errors um + + align:start position:0% +in addition experimental errors um + + + align:start position:0% +in addition experimental errors um +mustn't be swept under the rug you've + + align:start position:0% +mustn't be swept under the rug you've + + + align:start position:0% +mustn't be swept under the rug you've +got issues with mismatch there's a limit + + align:start position:0% +got issues with mismatch there's a limit + + + align:start position:0% +got issues with mismatch there's a limit +that just how cleverly you can design + + align:start position:0% +that just how cleverly you can design + + + align:start position:0% +that just how cleverly you can design +all these sequences + + align:start position:0% +all these sequences + + + align:start position:0% +all these sequences +as as the graph gets bigger you need to + + align:start position:0% +as as the graph gets bigger you need to + + + align:start position:0% +as as the graph gets bigger you need to +have more and more sequences involved + + align:start position:0% +have more and more sequences involved + + + align:start position:0% +have more and more sequences involved +and that that means that you're going to + + align:start position:0% +and that that means that you're going to + + + align:start position:0% +and that that means that you're going to +get more and more cross hybridization + + align:start position:0% +get more and more cross hybridization + + + align:start position:0% +get more and more cross hybridization +and complete cleavage and so forth + + align:start position:0% +and complete cleavage and so forth + + + align:start position:0% +and complete cleavage and so forth +there are + + align:start position:0% +there are + + + align:start position:0% +there are +when i when this slide 18 says + + align:start position:0% +when i when this slide 18 says + + + align:start position:0% +when i when this slide 18 says +non-reusable there are reusable forms + + align:start position:0% +non-reusable there are reusable forms + + + align:start position:0% +non-reusable there are reusable forms +and we'll get to those in just a minute + + align:start position:0% +and we'll get to those in just a minute + + + align:start position:0% +and we'll get to those in just a minute +so those are the disadvantages what are + + align:start position:0% +so those are the disadvantages what are + + + align:start position:0% +so those are the disadvantages what are +the promises or the possible advantages + + align:start position:0% +the promises or the possible advantages + + + align:start position:0% +the promises or the possible advantages +high parallelism could be much more than + + align:start position:0% +high parallelism could be much more than + + + align:start position:0% +high parallelism could be much more than +the 10 to the 12th full loss in the + + align:start position:0% +the 10 to the 12th full loss in the + + + align:start position:0% +the 10 to the 12th full loss in the +speed + + align:start position:0% + + + + align:start position:0% + +when + + align:start position:0% +when + + + align:start position:0% +when +when computer hardware + + align:start position:0% +when computer hardware + + + align:start position:0% +when computer hardware +and + + align:start position:0% +and + + + align:start position:0% +and +people dream of + + align:start position:0% +people dream of + + + align:start position:0% +people dream of +the + + align:start position:0% +the + + + align:start position:0% +the +next generation of computers they hope + + align:start position:0% +next generation of computers they hope + + + align:start position:0% +next generation of computers they hope +to get away from the current record + + align:start position:0% +to get away from the current record + + + align:start position:0% +to get away from the current record +which is around 10 to the ninth + + align:start position:0% +which is around 10 to the ninth + + + align:start position:0% +which is around 10 to the ninth +operations per joule + + align:start position:0% +operations per joule + + + align:start position:0% +operations per joule +for conventional computers + + align:start position:0% +for conventional computers + + + align:start position:0% +for conventional computers +maybe that's not a record but it's + + align:start position:0% +maybe that's not a record but it's + + + align:start position:0% +maybe that's not a record but it's +conventional computers um + + align:start position:0% +conventional computers um + + + align:start position:0% +conventional computers um +closer to the 34 times 10 of the 19th + + align:start position:0% +closer to the 34 times 10 of the 19th + + + align:start position:0% +closer to the 34 times 10 of the 19th +operations per joule you should be able + + align:start position:0% +operations per joule you should be able + + + align:start position:0% +operations per joule you should be able +to squeak out near the thermodynamic + + align:start position:0% +to squeak out near the thermodynamic + + + align:start position:0% +to squeak out near the thermodynamic +limit as it turns out + + align:start position:0% +limit as it turns out + + + align:start position:0% +limit as it turns out +many dna enzymes such as dna polymerase + + align:start position:0% +many dna enzymes such as dna polymerase + + + align:start position:0% +many dna enzymes such as dna polymerase +are already within a factor of 10 of + + align:start position:0% +are already within a factor of 10 of + + + align:start position:0% +are already within a factor of 10 of +that goal + + align:start position:0% +that goal + + + align:start position:0% +that goal +while conventional computers are off by + + align:start position:0% +while conventional computers are off by + + + align:start position:0% +while conventional computers are off by +10 factors of 10 or more + + align:start position:0% + + + + align:start position:0% + +if one can quote solve or + + align:start position:0% +if one can quote solve or + + + align:start position:0% +if one can quote solve or +one mp complete solve problem you can + + align:start position:0% +one mp complete solve problem you can + + + align:start position:0% +one mp complete solve problem you can +get many + + align:start position:0% +get many + + + align:start position:0% +get many +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +you know they're they're the + + align:start position:0% +you know they're they're the + + + align:start position:0% +you know they're they're the +improvements that we'll just kind of + + align:start position:0% +improvements that we'll just kind of + + + align:start position:0% +improvements that we'll just kind of +briefly talk about that are + + align:start position:0% +briefly talk about that are + + + align:start position:0% +briefly talk about that are +that + + align:start position:0% +that + + + align:start position:0% +that +keep people excited about this are that + + align:start position:0% +keep people excited about this are that + + + align:start position:0% +keep people excited about this are that +this is a natural way of talking to + + align:start position:0% +this is a natural way of talking to + + + align:start position:0% +this is a natural way of talking to +biological problems if there are + + align:start position:0% +biological problems if there are + + + align:start position:0% +biological problems if there are +biological problems + + align:start position:0% +biological problems + + + align:start position:0% +biological problems +you can + + align:start position:0% + + + + align:start position:0% + +it may be a smaller step to get to dna + + align:start position:0% +it may be a smaller step to get to dna + + + align:start position:0% +it may be a smaller step to get to dna +computing and there are faster readout + + align:start position:0% +computing and there are faster readout + + + align:start position:0% +computing and there are faster readout +methods just as there are faster and + + align:start position:0% +methods just as there are faster and + + + align:start position:0% +methods just as there are faster and +faster + + align:start position:0% +faster + + + align:start position:0% +faster +computational methods + + align:start position:0% +computational methods + + + align:start position:0% +computational methods +and natural selection evolution is + + align:start position:0% +and natural selection evolution is + + + align:start position:0% +and natural selection evolution is +something that you can use on dna + + align:start position:0% +something that you can use on dna + + + align:start position:0% +something that you can use on dna +computers which so far has not been + + align:start position:0% +computers which so far has not been + + + align:start position:0% +computers which so far has not been +extremely powerful in + + align:start position:0% +extremely powerful in + + + align:start position:0% +extremely powerful in +conventional computers + + align:start position:0% + + + + align:start position:0% + +although we'll talk about genetic + + align:start position:0% +although we'll talk about genetic + + + align:start position:0% +although we'll talk about genetic +algorithms shortly + + align:start position:0% +algorithms shortly + + + align:start position:0% +algorithms shortly +so one way of getting reuse is to have a + + align:start position:0% +so one way of getting reuse is to have a + + + align:start position:0% +so one way of getting reuse is to have a +so-called sticker-based model or + + align:start position:0% +so-called sticker-based model or + + + align:start position:0% +so-called sticker-based model or +something where you're basically just + + align:start position:0% +something where you're basically just + + + align:start position:0% +something where you're basically just +using + + align:start position:0% +using + + + align:start position:0% +using +hybridization properties without being + + align:start position:0% +hybridization properties without being + + + align:start position:0% +hybridization properties without being +destructive + + align:start position:0% +destructive + + + align:start position:0% +destructive +and and here's an example i'm not going + + align:start position:0% +and and here's an example i'm not going + + + align:start position:0% +and and here's an example i'm not going +to + + align:start position:0% +to + + + align:start position:0% +to +walk through it too much i should point + + align:start position:0% +walk through it too much i should point + + + align:start position:0% +walk through it too much i should point +out the at all in here include that one + + align:start position:0% +out the at all in here include that one + + + align:start position:0% +out the at all in here include that one +again + + align:start position:0% +again + + + align:start position:0% +again +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and uh i'll have + + align:start position:0% +and uh i'll have + + + align:start position:0% +and uh i'll have +one more example of his work in just a + + align:start position:0% +one more example of his work in just a + + + align:start position:0% +one more example of his work in just a +just a moment here but that they're + + align:start position:0% +just a moment here but that they're + + + align:start position:0% +just a moment here but that they're +they're + + align:start position:0% +they're + + + align:start position:0% +they're +they're examples now of of work + + align:start position:0% +they're examples now of of work + + + align:start position:0% +they're examples now of of work +trying to + + align:start position:0% +trying to + + + align:start position:0% +trying to +consider seriously the amount the + + align:start position:0% +consider seriously the amount the + + + align:start position:0% +consider seriously the amount the +volumes of dna that are needed and ways + + align:start position:0% +volumes of dna that are needed and ways + + + align:start position:0% +volumes of dna that are needed and ways +of dealing with + + align:start position:0% +of dealing with + + + align:start position:0% +of dealing with +fault tolerance or + + align:start position:0% +fault tolerance or + + + align:start position:0% +fault tolerance or +or error reduction algorithms where you + + align:start position:0% +or error reduction algorithms where you + + + align:start position:0% +or error reduction algorithms where you +actually go through and + + align:start position:0% +actually go through and + + + align:start position:0% +actually go through and +consciously say okay if we had an error + + align:start position:0% +consciously say okay if we had an error + + + align:start position:0% +consciously say okay if we had an error +here how would we + + align:start position:0% +here how would we + + + align:start position:0% +here how would we +compensate for it how would we dedicate + + align:start position:0% +compensate for it how would we dedicate + + + align:start position:0% +compensate for it how would we dedicate +a little more a few more bits + + align:start position:0% +a little more a few more bits + + + align:start position:0% +a little more a few more bits +to + + align:start position:0% +to + + + align:start position:0% +to +take the next step + + align:start position:0% +take the next step + + + align:start position:0% +take the next step +so + + align:start position:0% +so + + + align:start position:0% +so +just like in the the night + + align:start position:0% +just like in the the night + + + align:start position:0% +just like in the the night +test problem we had a little bit before + + align:start position:0% +test problem we had a little bit before + + + align:start position:0% +test problem we had a little bit before +the idea of using and and ors of uh + + align:start position:0% +the idea of using and and ors of uh + + + align:start position:0% +the idea of using and and ors of uh +boolean variables these x's in slide 21 + + align:start position:0% +boolean variables these x's in slide 21 + + + align:start position:0% +boolean variables these x's in slide 21 +which can have two states zero or one + + align:start position:0% +which can have two states zero or one + + + align:start position:0% +which can have two states zero or one +similar to the boolean variables that we + + align:start position:0% +similar to the boolean variables that we + + + align:start position:0% +similar to the boolean variables that we +run across time time and genetic models + + align:start position:0% +run across time time and genetic models + + + align:start position:0% +run across time time and genetic models +and you can have clauses which are + + align:start position:0% +and you can have clauses which are + + + align:start position:0% +and you can have clauses which are +basically + + align:start position:0% +basically + + + align:start position:0% +basically +logical operations on the set of boolean + + align:start position:0% +logical operations on the set of boolean + + + align:start position:0% +logical operations on the set of boolean +variables + + align:start position:0% +variables + + + align:start position:0% +variables +where you have + + align:start position:0% +where you have + + + align:start position:0% +where you have +knots and ors and ands okay and this + + align:start position:0% +knots and ors and ands okay and this + + + align:start position:0% +knots and ors and ands okay and this +kind of problem is a very general + + align:start position:0% +kind of problem is a very general + + + align:start position:0% +kind of problem is a very general +problem very interesting one and uh it + + align:start position:0% +problem very interesting one and uh it + + + align:start position:0% +problem very interesting one and uh it +has been tackled just in very analogous + + align:start position:0% +has been tackled just in very analogous + + + align:start position:0% +has been tackled just in very analogous +ways to the ways we've been talking + + align:start position:0% +ways to the ways we've been talking + + + align:start position:0% +ways to the ways we've been talking +about the previous ones + + align:start position:0% +about the previous ones + + + align:start position:0% +about the previous ones +where you encode the graph in dna + + align:start position:0% +where you encode the graph in dna + + + align:start position:0% +where you encode the graph in dna +sequences + + align:start position:0% +sequences + + + align:start position:0% +sequences +thereby creating all the paths by + + align:start position:0% +thereby creating all the paths by + + + align:start position:0% +thereby creating all the paths by +hybridization or something like that + + align:start position:0% +hybridization or something like that + + + align:start position:0% +hybridization or something like that +and then + + align:start position:0% +and then + + + align:start position:0% +and then +and then you read it out + + align:start position:0% +and then you read it out + + + align:start position:0% +and then you read it out +with + + align:start position:0% + + + + align:start position:0% + +with um + + align:start position:0% +with um + + + align:start position:0% +with um +pcr + + align:start position:0% +pcr + + + align:start position:0% +pcr +and um + + align:start position:0% +and um + + + align:start position:0% +and um +and solid phase + + align:start position:0% +and solid phase + + + align:start position:0% +and solid phase +and you could say you see here's a quote + + align:start position:0% +and you could say you see here's a quote + + + align:start position:0% +and you could say you see here's a quote +where they say here we solve an np + + align:start position:0% +where they say here we solve an np + + + align:start position:0% +where they say here we solve an np +complete problem + + align:start position:0% +complete problem + + + align:start position:0% +complete problem +they have indeed solved one but + + align:start position:0% +they have indeed solved one but + + + align:start position:0% +they have indeed solved one but +you know they haven't + + align:start position:0% +you know they haven't + + + align:start position:0% +you know they haven't +they haven't really turned it into a a + + align:start position:0% +they haven't really turned it into a a + + + align:start position:0% +they haven't really turned it into a a +polynomial time problem they simply + + align:start position:0% +polynomial time problem they simply + + + align:start position:0% +polynomial time problem they simply +forced it out + + align:start position:0% +forced it out + + + align:start position:0% +forced it out +and this is the most recent one just it + + align:start position:0% +and this is the most recent one just it + + + align:start position:0% +and this is the most recent one just it +came out in science again when adelman + + align:start position:0% +came out in science again when adelman + + + align:start position:0% +came out in science again when adelman +on it and now up to 20 variables in a + + align:start position:0% +on it and now up to 20 variables in a + + + align:start position:0% +on it and now up to 20 variables in a +three-stat problem + + align:start position:0% +three-stat problem + + + align:start position:0% +three-stat problem +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's all about computing it may not + + align:start position:0% +so that's all about computing it may not + + + align:start position:0% +so that's all about computing it may not +since + + align:start position:0% +since + + + align:start position:0% +since +dna is relatively slow at computing + + align:start position:0% +dna is relatively slow at computing + + + align:start position:0% +dna is relatively slow at computing +per step highly parallel it may not be + + align:start position:0% +per step highly parallel it may not be + + + align:start position:0% +per step highly parallel it may not be +the best of the various steps in + + align:start position:0% +the best of the various steps in + + + align:start position:0% +the best of the various steps in +computing assembly + + align:start position:0% +computing assembly + + + align:start position:0% +computing assembly +input memory + + align:start position:0% +input memory + + + align:start position:0% +input memory +computation and output so we'll explore + + align:start position:0% +computation and output so we'll explore + + + align:start position:0% +computation and output so we'll explore +some of the other ones in particular + + align:start position:0% +some of the other ones in particular + + + align:start position:0% +some of the other ones in particular +assembly to a certain extent assembling + + align:start position:0% +assembly to a certain extent assembling + + + align:start position:0% +assembly to a certain extent assembling +computers is slow and so it's something + + align:start position:0% +computers is slow and so it's something + + + align:start position:0% +computers is slow and so it's something +where + + align:start position:0% +where + + + align:start position:0% +where +molecular + + align:start position:0% +molecular + + + align:start position:0% +molecular +assembly might have some advantages + + align:start position:0% +assembly might have some advantages + + + align:start position:0% +assembly might have some advantages +now this particular example + + align:start position:0% +now this particular example + + + align:start position:0% +now this particular example +i'm i'm going to emphasize the assembly + + align:start position:0% +i'm i'm going to emphasize the assembly + + + align:start position:0% +i'm i'm going to emphasize the assembly +aspect of it but you can think of this + + align:start position:0% +aspect of it but you can think of this + + + align:start position:0% +aspect of it but you can think of this +as a way of mapping these authors have + + align:start position:0% +as a way of mapping these authors have + + + align:start position:0% +as a way of mapping these authors have +mapped + + align:start position:0% +mapped + + + align:start position:0% +mapped +a assembly of an actual two-dimensional + + align:start position:0% +a assembly of an actual two-dimensional + + + align:start position:0% +a assembly of an actual two-dimensional +piling + + align:start position:0% +piling + + + align:start position:0% +piling +onto + + align:start position:0% +onto + + + align:start position:0% +onto +an + + align:start position:0% +an + + + align:start position:0% +an +abstract but important and powerful + + align:start position:0% +abstract but important and powerful + + + align:start position:0% +abstract but important and powerful +computer science concept which is a + + align:start position:0% +computer science concept which is a + + + align:start position:0% +computer science concept which is a +general turing machine a machine a kind + + align:start position:0% +general turing machine a machine a kind + + + align:start position:0% +general turing machine a machine a kind +of a tape like structure that can + + align:start position:0% +of a tape like structure that can + + + align:start position:0% +of a tape like structure that can +compute + + align:start position:0% +compute + + + align:start position:0% +compute +do any kind of general + + align:start position:0% +do any kind of general + + + align:start position:0% +do any kind of general +computing deterministic computing + + align:start position:0% +computing deterministic computing + + + align:start position:0% +computing deterministic computing +and + + align:start position:0% +and + + + align:start position:0% +and +so they've mapped a kind of a physical + + align:start position:0% +so they've mapped a kind of a physical + + + align:start position:0% +so they've mapped a kind of a physical +tiling as you might have a you know + + align:start position:0% +tiling as you might have a you know + + + align:start position:0% +tiling as you might have a you know +periodic or a periodic mosaic of tiles + + align:start position:0% +periodic or a periodic mosaic of tiles + + + align:start position:0% +periodic or a periodic mosaic of tiles +onto this computing machine + + align:start position:0% +onto this computing machine + + + align:start position:0% +onto this computing machine +and onto this kind of logical operation + + align:start position:0% +and onto this kind of logical operation + + + align:start position:0% +and onto this kind of logical operation +x4 + + align:start position:0% +x4 + + + align:start position:0% +x4 +on a string of binary bits just as we + + align:start position:0% +on a string of binary bits just as we + + + align:start position:0% +on a string of binary bits just as we +had the previous couple of slides on the + + align:start position:0% +had the previous couple of slides on the + + + align:start position:0% +had the previous couple of slides on the +on the three-stat problem + + align:start position:0% +on the three-stat problem + + + align:start position:0% +on the three-stat problem +i'm going to emphasize the geometric + + align:start position:0% +i'm going to emphasize the geometric + + + align:start position:0% +i'm going to emphasize the geometric +physical version of it because we're + + align:start position:0% +physical version of it because we're + + + align:start position:0% +physical version of it because we're +trying to make a transition now in this + + align:start position:0% +trying to make a transition now in this + + + align:start position:0% +trying to make a transition now in this +paper which combines the dna computing + + align:start position:0% +paper which combines the dna computing + + + align:start position:0% +paper which combines the dna computing +with the dna assembly + + align:start position:0% +with the dna assembly + + + align:start position:0% +with the dna assembly +now up it + + align:start position:0% +now up it + + + align:start position:0% +now up it +we have three more or less equivalent + + align:start position:0% +we have three more or less equivalent + + + align:start position:0% +we have three more or less equivalent +ways of representing the same sort of + + align:start position:0% +ways of representing the same sort of + + + align:start position:0% +ways of representing the same sort of +sequences now these are called triple + + align:start position:0% +sequences now these are called triple + + + align:start position:0% +sequences now these are called triple +crossovers because you can see + + align:start position:0% +crossovers because you can see + + + align:start position:0% +crossovers because you can see +let's take a look at + + align:start position:0% +let's take a look at + + + align:start position:0% +let's take a look at +say y2 here and right in the middle of + + align:start position:0% +say y2 here and right in the middle of + + + align:start position:0% +say y2 here and right in the middle of +the slide + + align:start position:0% +the slide + + + align:start position:0% +the slide +you can see that there are these + + align:start position:0% +you can see that there are these + + + align:start position:0% +you can see that there are these +multiple crossovers where you have a + + align:start position:0% +multiple crossovers where you have a + + + align:start position:0% +multiple crossovers where you have a +kind of a recombination + + align:start position:0% +kind of a recombination + + + align:start position:0% +kind of a recombination +event where you've got two + + align:start position:0% +event where you've got two + + + align:start position:0% +event where you've got two +double-stranded dna molecules that are + + align:start position:0% +double-stranded dna molecules that are + + + align:start position:0% +double-stranded dna molecules that are +exchanging a strand and this is not a + + align:start position:0% +exchanging a strand and this is not a + + + align:start position:0% +exchanging a strand and this is not a +natural homologous recombination event + + align:start position:0% +natural homologous recombination event + + + align:start position:0% +natural homologous recombination event +in the since they're non-homologous and + + align:start position:0% +in the since they're non-homologous and + + + align:start position:0% +in the since they're non-homologous and +this thing is kind of trapped in this + + align:start position:0% +this thing is kind of trapped in this + + + align:start position:0% +this thing is kind of trapped in this +crossover and the crossover when you + + align:start position:0% +crossover and the crossover when you + + + align:start position:0% +crossover and the crossover when you +have a multiple crossovers you can make + + align:start position:0% +have a multiple crossovers you can make + + + align:start position:0% +have a multiple crossovers you can make +a piece of dna that now has more than + + align:start position:0% +a piece of dna that now has more than + + + align:start position:0% +a piece of dna that now has more than +just two ends you can have multiple + + align:start position:0% +just two ends you can have multiple + + + align:start position:0% +just two ends you can have multiple +sticky ends you can have say in this + + align:start position:0% +sticky ends you can have say in this + + + align:start position:0% +sticky ends you can have say in this +case in the upper part you can see four + + align:start position:0% +case in the upper part you can see four + + + align:start position:0% +case in the upper part you can see four +different ends + + align:start position:0% +different ends + + + align:start position:0% +different ends +with + + align:start position:0% + + + + align:start position:0% + +one two three + + align:start position:0% +one two three + + + align:start position:0% +one two three +four crossover strands here and each of + + align:start position:0% +four crossover strands here and each of + + + align:start position:0% +four crossover strands here and each of +these + + align:start position:0% + + + + align:start position:0% + +you can see on the far + + align:start position:0% +you can see on the far + + + align:start position:0% +you can see on the far +right a five base three prime overhang + + align:start position:0% +right a five base three prime overhang + + + align:start position:0% +right a five base three prime overhang +and a seven base five prime overhang and + + align:start position:0% +and a seven base five prime overhang and + + + align:start position:0% +and a seven base five prime overhang and +some flush ends on the far left and so + + align:start position:0% +some flush ends on the far left and so + + + align:start position:0% +some flush ends on the far left and so +each of these things has + + align:start position:0% +each of these things has + + + align:start position:0% +each of these things has +uh ability to stick stick to other uh + + align:start position:0% +uh ability to stick stick to other uh + + + align:start position:0% +uh ability to stick stick to other uh +tiling elements and you can see that you + + align:start position:0% +tiling elements and you can see that you + + + align:start position:0% +tiling elements and you can see that you +can put together a + + align:start position:0% +can put together a + + + align:start position:0% +can put together a +a two-dimensional + + align:start position:0% +a two-dimensional + + + align:start position:0% +a two-dimensional +structure + + align:start position:0% +structure + + + align:start position:0% +structure +which can be as an intricate as a mosaic + + align:start position:0% +which can be as an intricate as a mosaic + + + align:start position:0% +which can be as an intricate as a mosaic +it does not have to repeat itself or it + + align:start position:0% +it does not have to repeat itself or it + + + align:start position:0% +it does not have to repeat itself or it +can repeat itself if you want to use um + + align:start position:0% +can repeat itself if you want to use um + + + align:start position:0% +can repeat itself if you want to use um +you know visual + + align:start position:0% +you know visual + + + align:start position:0% +you know visual +tools such as 40 transforms to look at a + + align:start position:0% +tools such as 40 transforms to look at a + + + align:start position:0% +tools such as 40 transforms to look at a +repeating structure and you can see you + + align:start position:0% +repeating structure and you can see you + + + align:start position:0% +repeating structure and you can see you +can you can engineer in restriction + + align:start position:0% +can you can engineer in restriction + + + align:start position:0% +can you can engineer in restriction +sites to help you analyze + + align:start position:0% +sites to help you analyze + + + align:start position:0% +sites to help you analyze +the structure on on a gel based assay on + + align:start position:0% +the structure on on a gel based assay on + + + align:start position:0% +the structure on on a gel based assay on +the far left + + align:start position:0% +the far left + + + align:start position:0% +the far left +we've seen enough gel based assays + + align:start position:0% +we've seen enough gel based assays + + + align:start position:0% +we've seen enough gel based assays +tonight already i will be labeled we're + + align:start position:0% +tonight already i will be labeled we're + + + align:start position:0% +tonight already i will be labeled we're +not going to walk you through it but you + + align:start position:0% +not going to walk you through it but you + + + align:start position:0% +not going to walk you through it but you +can see that there's even though this is + + align:start position:0% +can see that there's even though this is + + + align:start position:0% +can see that there's even though this is +not straight dna as the previous uh two + + align:start position:0% +not straight dna as the previous uh two + + + align:start position:0% +not straight dna as the previous uh two +or three examples where this is a much + + align:start position:0% +or three examples where this is a much + + + align:start position:0% +or three examples where this is a much +more complicated branch structure + + align:start position:0% +more complicated branch structure + + + align:start position:0% +more complicated branch structure +nevertheless you can + + align:start position:0% +nevertheless you can + + + align:start position:0% +nevertheless you can +turn it into a linear readout with + + align:start position:0% +turn it into a linear readout with + + + align:start position:0% +turn it into a linear readout with +electrophoretic sizes + + align:start position:0% +electrophoretic sizes + + + align:start position:0% +electrophoretic sizes +but you can also look at it as a truly + + align:start position:0% +but you can also look at it as a truly + + + align:start position:0% +but you can also look at it as a truly +two or three dimensional object here + + align:start position:0% +two or three dimensional object here + + + align:start position:0% +two or three dimensional object here +here we use atomic they use atomic force + + align:start position:0% +here we use atomic they use atomic force + + + align:start position:0% +here we use atomic they use atomic force +microscopy + + align:start position:0% +microscopy + + + align:start position:0% +microscopy +where a probe with a single atom at its + + align:start position:0% +where a probe with a single atom at its + + + align:start position:0% +where a probe with a single atom at its +tip + + align:start position:0% +tip + + + align:start position:0% +tip +is responsing to responding to the force + + align:start position:0% +is responsing to responding to the force + + + align:start position:0% +is responsing to responding to the force +that allows that as you touch an object + + align:start position:0% + + + + align:start position:0% + +the feedback in the system with a + + align:start position:0% +the feedback in the system with a + + + align:start position:0% +the feedback in the system with a +scanning telling microscope usually as a + + align:start position:0% +scanning telling microscope usually as a + + + align:start position:0% +scanning telling microscope usually as a +part of the feedback + + align:start position:0% +part of the feedback + + + align:start position:0% +part of the feedback +tells you that you've just touched the + + align:start position:0% +tells you that you've just touched the + + + align:start position:0% +tells you that you've just touched the +surface and you bound to back off a + + align:start position:0% +surface and you bound to back off a + + + align:start position:0% +surface and you bound to back off a +little bit and then you scan along and + + align:start position:0% +little bit and then you scan along and + + + align:start position:0% +little bit and then you scan along and +just just profiling the surface + + align:start position:0% +just just profiling the surface + + + align:start position:0% +just just profiling the surface +and so here with two different tiling + + align:start position:0% +and so here with two different tiling + + + align:start position:0% +and so here with two different tiling +methods this is more repetitive rather + + align:start position:0% +methods this is more repetitive rather + + + align:start position:0% +methods this is more repetitive rather +than an aperiodic title tiling you can + + align:start position:0% +than an aperiodic title tiling you can + + + align:start position:0% +than an aperiodic title tiling you can +see that these little pink protrusions + + align:start position:0% +see that these little pink protrusions + + + align:start position:0% +see that these little pink protrusions +you can engineer into the tile + + align:start position:0% +you can engineer into the tile + + + align:start position:0% +you can engineer into the tile +not just the two-dimensional stickiness + + align:start position:0% +not just the two-dimensional stickiness + + + align:start position:0% +not just the two-dimensional stickiness +sticky + + align:start position:0% +sticky + + + align:start position:0% +sticky +tags but a third dimension which is a + + align:start position:0% +tags but a third dimension which is a + + + align:start position:0% +tags but a third dimension which is a +bump which might be a um + + align:start position:0% +bump which might be a um + + + align:start position:0% +bump which might be a um +a stem loop as we've seen in other + + align:start position:0% +a stem loop as we've seen in other + + + align:start position:0% +a stem loop as we've seen in other +secondary structures there's engineering + + align:start position:0% +secondary structures there's engineering + + + align:start position:0% +secondary structures there's engineering +into this dna so now that these bumps + + align:start position:0% +into this dna so now that these bumps + + + align:start position:0% +into this dna so now that these bumps +will stick up and the easy targets for + + align:start position:0% +will stick up and the easy targets for + + + align:start position:0% +will stick up and the easy targets for +the atomic force microscope and here you + + align:start position:0% +the atomic force microscope and here you + + + align:start position:0% +the atomic force microscope and here you +have a bump every every second uh tile + + align:start position:0% +have a bump every every second uh tile + + + align:start position:0% +have a bump every every second uh tile +and that's on the left and on the right + + align:start position:0% +and that's on the left and on the right + + + align:start position:0% +and that's on the left and on the right +of slide 27 you have a more complicated + + align:start position:0% +of slide 27 you have a more complicated + + + align:start position:0% +of slide 27 you have a more complicated +tiling where you have four different + + align:start position:0% +tiling where you have four different + + + align:start position:0% +tiling where you have four different +types of tiles + + align:start position:0% +types of tiles + + + align:start position:0% +types of tiles +and a bump every + + align:start position:0% +and a bump every + + + align:start position:0% +and a bump every +fourth one and so you expect you can + + align:start position:0% +fourth one and so you expect you can + + + align:start position:0% +fourth one and so you expect you can +calculate from the the uh + + align:start position:0% +calculate from the the uh + + + align:start position:0% +calculate from the the uh +watson crick model for dna or more + + align:start position:0% +watson crick model for dna or more + + + align:start position:0% +watson crick model for dna or more +advanced models of dna even though this + + align:start position:0% +advanced models of dna even though this + + + align:start position:0% +advanced models of dna even though this +is a a lattice of + + align:start position:0% +is a a lattice of + + + align:start position:0% +is a a lattice of +brain structures you can calculate it + + align:start position:0% +brain structures you can calculate it + + + align:start position:0% +brain structures you can calculate it +should be about 33 nanometers between + + align:start position:0% +should be about 33 nanometers between + + + align:start position:0% +should be about 33 nanometers between +the bumps that's what's observed and 65 + + align:start position:0% +the bumps that's what's observed and 65 + + + align:start position:0% +the bumps that's what's observed and 65 +nanometers is calculated and observed + + align:start position:0% +nanometers is calculated and observed + + + align:start position:0% +nanometers is calculated and observed +you can see the bigger lattice facing in + + align:start position:0% +you can see the bigger lattice facing in + + + align:start position:0% +you can see the bigger lattice facing in +these admittedly somewhat fuzzy atomic + + align:start position:0% +these admittedly somewhat fuzzy atomic + + + align:start position:0% +these admittedly somewhat fuzzy atomic +force micrographs + + align:start position:0% +force micrographs + + + align:start position:0% +force micrographs +but you can see you get something + + align:start position:0% +but you can see you get something + + + align:start position:0% +but you can see you get something +experimental confirmation of the + + align:start position:0% +experimental confirmation of the + + + align:start position:0% +experimental confirmation of the +two-dimensional + + align:start position:0% +two-dimensional + + + align:start position:0% +two-dimensional +structures here + + align:start position:0% +structures here + + + align:start position:0% +structures here +now + + align:start position:0% +now + + + align:start position:0% +now +this is a self-assembly nanofabrication + + align:start position:0% +this is a self-assembly nanofabrication + + + align:start position:0% +this is a self-assembly nanofabrication +and and at some extent it is inspired by + + align:start position:0% +and and at some extent it is inspired by + + + align:start position:0% +and and at some extent it is inspired by +and is and can be combined with + + align:start position:0% +and is and can be combined with + + + align:start position:0% +and is and can be combined with +microfabrication this is something where + + align:start position:0% +microfabrication this is something where + + + align:start position:0% +microfabrication this is something where +you basically use optics you go to the + + align:start position:0% +you basically use optics you go to the + + + align:start position:0% +you basically use optics you go to the +limit of current uh optical + + align:start position:0% +limit of current uh optical + + + align:start position:0% +limit of current uh optical +manufacturing + + align:start position:0% +manufacturing + + + align:start position:0% +manufacturing +as a micro fabrication where it's + + align:start position:0% +as a micro fabrication where it's + + + align:start position:0% +as a micro fabrication where it's +typically hard to get below + + align:start position:0% +typically hard to get below + + + align:start position:0% +typically hard to get below +say 100 nanometers or so in feature size + + align:start position:0% +say 100 nanometers or so in feature size + + + align:start position:0% +say 100 nanometers or so in feature size +here you can see this is uh + + align:start position:0% +here you can see this is uh + + + align:start position:0% +here you can see this is uh +and this is the sort of micro + + align:start position:0% +and this is the sort of micro + + + align:start position:0% +and this is the sort of micro +fabrication used to make your uh + + align:start position:0% +fabrication used to make your uh + + + align:start position:0% +fabrication used to make your uh +computer chips + + align:start position:0% +computer chips + + + align:start position:0% +computer chips +but it's uh + + align:start position:0% +but it's uh + + + align:start position:0% +but it's uh +in this case it's used to actually make + + align:start position:0% +in this case it's used to actually make + + + align:start position:0% +in this case it's used to actually make +moving parts parts that move relative to + + align:start position:0% +moving parts parts that move relative to + + + align:start position:0% +moving parts parts that move relative to +one another and that that motion + + align:start position:0% +one another and that that motion + + + align:start position:0% +one another and that that motion +um + + align:start position:0% +um + + + align:start position:0% +um +actually has useful um + + align:start position:0% + + + + align:start position:0% + +applications the first such useful + + align:start position:0% +applications the first such useful + + + align:start position:0% +applications the first such useful +application that i'm aware + + align:start position:0% +application that i'm aware + + + align:start position:0% +application that i'm aware +is putting these things into airbag + + align:start position:0% +is putting these things into airbag + + + align:start position:0% +is putting these things into airbag +sensors and the idea is that when you're + + align:start position:0% +sensors and the idea is that when you're + + + align:start position:0% +sensors and the idea is that when you're +driving your large automobile and run + + align:start position:0% +driving your large automobile and run + + + align:start position:0% +driving your large automobile and run +into a even larger object + + align:start position:0% +into a even larger object + + + align:start position:0% +into a even larger object +you suddenly decelerate either by breaks + + align:start position:0% +you suddenly decelerate either by breaks + + + align:start position:0% +you suddenly decelerate either by breaks +or some other method + + align:start position:0% +or some other method + + + align:start position:0% +or some other method +and + + align:start position:0% +and + + + align:start position:0% +and +when you do + + align:start position:0% +when you do + + + align:start position:0% +when you do +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this little bitty device + + align:start position:0% +this little bitty device + + + align:start position:0% +this little bitty device +ins sensor inside your somewhere in your + + align:start position:0% +ins sensor inside your somewhere in your + + + align:start position:0% +ins sensor inside your somewhere in your +car + + align:start position:0% +car + + + align:start position:0% +car +will shift one of its parts by at least + + align:start position:0% +will shift one of its parts by at least + + + align:start position:0% +will shift one of its parts by at least +point two angstroms meaning a tenth of + + align:start position:0% +point two angstroms meaning a tenth of + + + align:start position:0% +point two angstroms meaning a tenth of +an atomic diameter that doesn't seem + + align:start position:0% +an atomic diameter that doesn't seem + + + align:start position:0% +an atomic diameter that doesn't seem +like very much and it isn't it only + + align:start position:0% +like very much and it isn't it only + + + align:start position:0% +like very much and it isn't it only +causes a hundred femtofarads that means + + align:start position:0% +causes a hundred femtofarads that means + + + align:start position:0% +causes a hundred femtofarads that means +10 to the minus 13 farad capacitors + + align:start position:0% +10 to the minus 13 farad capacitors + + + align:start position:0% +10 to the minus 13 farad capacitors +change but that's quite enough to signal + + align:start position:0% +change but that's quite enough to signal + + + align:start position:0% +change but that's quite enough to signal +a uh + + align:start position:0% + + + + align:start position:0% + +that a collision has occurred or will + + align:start position:0% +that a collision has occurred or will + + + align:start position:0% +that a collision has occurred or will +occur + + align:start position:0% +occur + + + align:start position:0% +occur +and + + align:start position:0% +and + + + align:start position:0% +and +with a very low false positive rate + + align:start position:0% +with a very low false positive rate + + + align:start position:0% +with a very low false positive rate +those of you who have driven large + + align:start position:0% +those of you who have driven large + + + align:start position:0% +those of you who have driven large +automobiles know how infrequently the + + align:start position:0% +automobiles know how infrequently the + + + align:start position:0% +automobiles know how infrequently the +airbag opens up accidentally + + align:start position:0% +airbag opens up accidentally + + + align:start position:0% +airbag opens up accidentally +but when it does deflect by 0.2 + + align:start position:0% +but when it does deflect by 0.2 + + + align:start position:0% +but when it does deflect by 0.2 +angstroms then it does open up the + + align:start position:0% +angstroms then it does open up the + + + align:start position:0% +angstroms then it does open up the +airbag okay so this is a payoff of + + align:start position:0% +airbag okay so this is a payoff of + + + align:start position:0% +airbag okay so this is a payoff of +microfabrication but now we want to + + align:start position:0% +microfabrication but now we want to + + + align:start position:0% +microfabrication but now we want to +combine the sort of nano systems we saw + + align:start position:0% +combine the sort of nano systems we saw + + + align:start position:0% +combine the sort of nano systems we saw +in the dna computers and in the tiling + + align:start position:0% +in the dna computers and in the tiling + + + align:start position:0% +in the dna computers and in the tiling +with microfabrication + + align:start position:0% +with microfabrication + + + align:start position:0% +with microfabrication +and i think this is just one of the very + + align:start position:0% +and i think this is just one of the very + + + align:start position:0% +and i think this is just one of the very +few examples where microfab meets + + align:start position:0% +few examples where microfab meets + + + align:start position:0% +few examples where microfab meets +nanofabrication and we'll call it a + + align:start position:0% +nanofabrication and we'll call it a + + + align:start position:0% +nanofabrication and we'll call it a +nanoelectromechanical system + + align:start position:0% +nanoelectromechanical system + + + align:start position:0% +nanoelectromechanical system +and here so you've got the + + align:start position:0% +and here so you've got the + + + align:start position:0% +and here so you've got the +microfabrication of both the posts upon + + align:start position:0% +microfabrication of both the posts upon + + + align:start position:0% +microfabrication of both the posts upon +which these things stand which is sort + + align:start position:0% +which these things stand which is sort + + + align:start position:0% +which these things stand which is sort +of these nickel columns of of + + align:start position:0% +of these nickel columns of of + + + align:start position:0% +of these nickel columns of of +you know 80 nanometers and the little + + align:start position:0% + + + + align:start position:0% + +bars metal bars + + align:start position:0% +bars metal bars + + + align:start position:0% +bars metal bars +which can be a sort of a micron range + + align:start position:0% +which can be a sort of a micron range + + + align:start position:0% +which can be a sort of a micron range +and that and you can see them visualized + + align:start position:0% +and that and you can see them visualized + + + align:start position:0% +and that and you can see them visualized +in the left-hand photograph where you + + align:start position:0% +in the left-hand photograph where you + + + align:start position:0% +in the left-hand photograph where you +have these bars at regular spacings + + align:start position:0% +have these bars at regular spacings + + + align:start position:0% +have these bars at regular spacings +and + + align:start position:0% +and + + + align:start position:0% +and +if you look at this publication or the + + align:start position:0% +if you look at this publication or the + + + align:start position:0% +if you look at this publication or the +the webs that go along with it these + + align:start position:0% +the webs that go along with it these + + + align:start position:0% +the webs that go along with it these +little bars will spin around + + align:start position:0% +little bars will spin around + + + align:start position:0% +little bars will spin around +and what they're spinning on is not a + + align:start position:0% +and what they're spinning on is not a + + + align:start position:0% +and what they're spinning on is not a +microfabricated motor but it is a + + align:start position:0% +microfabricated motor but it is a + + + align:start position:0% +microfabricated motor but it is a +nano biotech motor which and actually + + align:start position:0% +nano biotech motor which and actually + + + align:start position:0% +nano biotech motor which and actually +it's a protein that most people didn't + + align:start position:0% +it's a protein that most people didn't + + + align:start position:0% +it's a protein that most people didn't +think of on the motor + + align:start position:0% +think of on the motor + + + align:start position:0% +think of on the motor +when it was first discovered it is the + + align:start position:0% +when it was first discovered it is the + + + align:start position:0% +when it was first discovered it is the +the protein present in almost all + + align:start position:0% +the protein present in almost all + + + align:start position:0% +the protein present in almost all +organisms + + align:start position:0% +organisms + + + align:start position:0% +organisms +that is responsible for atp generation + + align:start position:0% +that is responsible for atp generation + + + align:start position:0% +that is responsible for atp generation +usually think of this as making atp for + + align:start position:0% +usually think of this as making atp for + + + align:start position:0% +usually think of this as making atp for +other motor for motors to use but this + + align:start position:0% +other motor for motors to use but this + + + align:start position:0% +other motor for motors to use but this +actually since it is capable of rotary + + align:start position:0% +actually since it is capable of rotary + + + align:start position:0% +actually since it is capable of rotary +motion + + align:start position:0% +motion + + + align:start position:0% +motion +does does move this one micron bar + + align:start position:0% +does does move this one micron bar + + + align:start position:0% +does does move this one micron bar +around + + align:start position:0% +around + + + align:start position:0% +around +at the rate that you would expect + + align:start position:0% + + + + align:start position:0% + +for uh for those for a nano machine to + + align:start position:0% +for uh for those for a nano machine to + + + align:start position:0% +for uh for those for a nano machine to +be generating torque + + align:start position:0% +be generating torque + + + align:start position:0% +be generating torque +okay so that's uh so we're now we've + + align:start position:0% +okay so that's uh so we're now we've + + + align:start position:0% +okay so that's uh so we're now we've +talked about assembly that's an example + + align:start position:0% +talked about assembly that's an example + + + align:start position:0% +talked about assembly that's an example +of an output device what sort of input + + align:start position:0% +of an output device what sort of input + + + align:start position:0% +of an output device what sort of input +devices we have that will work at the + + align:start position:0% +devices we have that will work at the + + + align:start position:0% +devices we have that will work at the +single molecule level + + align:start position:0% + + + + align:start position:0% + +here is uh there are many examples we + + align:start position:0% +here is uh there are many examples we + + + align:start position:0% +here is uh there are many examples we +mentioned a few of them uh in the + + align:start position:0% +mentioned a few of them uh in the + + + align:start position:0% +mentioned a few of them uh in the +sequencing + + align:start position:0% +sequencing + + + align:start position:0% +sequencing +genotyping lecture where we were talking + + align:start position:0% +genotyping lecture where we were talking + + + align:start position:0% +genotyping lecture where we were talking +about single fluorophores + + align:start position:0% +about single fluorophores + + + align:start position:0% +about single fluorophores +here you can use another aspect of + + align:start position:0% +here you can use another aspect of + + + align:start position:0% +here you can use another aspect of +biology + + align:start position:0% + + + + align:start position:0% + +which is a self-assembly of membranes to + + align:start position:0% +which is a self-assembly of membranes to + + + align:start position:0% +which is a self-assembly of membranes to +make a very + + align:start position:0% +make a very + + + align:start position:0% +make a very +very tight + + align:start position:0% +very tight + + + align:start position:0% +very tight +low conductance seal + + align:start position:0% +low conductance seal + + + align:start position:0% +low conductance seal +which is only on the order of two + + align:start position:0% +which is only on the order of two + + + align:start position:0% +which is only on the order of two +nanometers thick but it's enough to make + + align:start position:0% +nanometers thick but it's enough to make + + + align:start position:0% +nanometers thick but it's enough to make +a giga ohm seal a multi gig ohm seal and + + align:start position:0% +a giga ohm seal a multi gig ohm seal and + + + align:start position:0% +a giga ohm seal a multi gig ohm seal and +then you poke a little hole in it with a + + align:start position:0% +then you poke a little hole in it with a + + + align:start position:0% +then you poke a little hole in it with a +single molecule of a protein + + align:start position:0% +single molecule of a protein + + + align:start position:0% +single molecule of a protein +and they're they're + + align:start position:0% +and they're they're + + + align:start position:0% +and they're they're +growing ways to do this on inorganic + + align:start position:0% +growing ways to do this on inorganic + + + align:start position:0% +growing ways to do this on inorganic +substrates as well + + align:start position:0% +substrates as well + + + align:start position:0% +substrates as well +so + + align:start position:0% +so + + + align:start position:0% +so +when you have a single protein pour + + align:start position:0% +when you have a single protein pour + + + align:start position:0% +when you have a single protein pour +which itself might be a one nanometer + + align:start position:0% +which itself might be a one nanometer + + + align:start position:0% +which itself might be a one nanometer +opening + + align:start position:0% +opening + + + align:start position:0% +opening +it will it will allow in the presence of + + align:start position:0% +it will it will allow in the presence of + + + align:start position:0% +it will it will allow in the presence of +electric field indicated by these + + align:start position:0% +electric field indicated by these + + + align:start position:0% +electric field indicated by these +negative and positive charges here + + align:start position:0% +negative and positive charges here + + + align:start position:0% +negative and positive charges here +of + + align:start position:0% +of + + + align:start position:0% +of +yellow negative and positive ions to go + + align:start position:0% +yellow negative and positive ions to go + + + align:start position:0% +yellow negative and positive ions to go +through it's like sodium chloride + + align:start position:0% +through it's like sodium chloride + + + align:start position:0% +through it's like sodium chloride +and they will go through it about + + align:start position:0% + + + + align:start position:0% + +up to a million ions per second + + align:start position:0% +up to a million ions per second + + + align:start position:0% +up to a million ions per second +easily + + align:start position:0% +easily + + + align:start position:0% +easily +and when you + + align:start position:0% +and when you + + + align:start position:0% +and when you +have a larger molecule that's that's say + + align:start position:0% +have a larger molecule that's that's say + + + align:start position:0% +have a larger molecule that's that's say +a polyanion in the electric field it + + align:start position:0% +a polyanion in the electric field it + + + align:start position:0% +a polyanion in the electric field it +will slowly migrate through this pore + + align:start position:0% +will slowly migrate through this pore + + + align:start position:0% +will slowly migrate through this pore +and while it does so it blocks the rapid + + align:start position:0% +and while it does so it blocks the rapid + + + align:start position:0% +and while it does so it blocks the rapid +movement of the smaller ions like sodium + + align:start position:0% + + + + align:start position:0% + +and you can record + + align:start position:0% +and you can record + + + align:start position:0% +and you can record +the uh it doesn't it doesn't necessarily + + align:start position:0% +the uh it doesn't it doesn't necessarily + + + align:start position:0% +the uh it doesn't it doesn't necessarily +completely block the channel you can + + align:start position:0% +completely block the channel you can + + + align:start position:0% +completely block the channel you can +record the rate which sodium will go + + align:start position:0% +record the rate which sodium will go + + + align:start position:0% +record the rate which sodium will go +through and how it's influenced by the + + align:start position:0% +through and how it's influenced by the + + + align:start position:0% +through and how it's influenced by the +composition of the of the polymer um + + align:start position:0% +composition of the of the polymer um + + + align:start position:0% +composition of the of the polymer um +going through and so here's an example + + align:start position:0% +going through and so here's an example + + + align:start position:0% +going through and so here's an example +of a bacterial protein + + align:start position:0% +of a bacterial protein + + + align:start position:0% +of a bacterial protein +this is mellor at all reference down + + align:start position:0% +this is mellor at all reference down + + + align:start position:0% +this is mellor at all reference down +below + + align:start position:0% +below + + + align:start position:0% +below +um a bacterial + + align:start position:0% +um a bacterial + + + align:start position:0% +um a bacterial +toxin actually from + + align:start position:0% +toxin actually from + + + align:start position:0% +toxin actually from +staphylococcus + + align:start position:0% +staphylococcus + + + align:start position:0% +staphylococcus +whose goal in life is not is to is you + + align:start position:0% +whose goal in life is not is to is you + + + align:start position:0% +whose goal in life is not is to is you +know is to kill other organisms it's not + + align:start position:0% +know is to kill other organisms it's not + + + align:start position:0% +know is to kill other organisms it's not +to provide a handy conduit for rna to go + + align:start position:0% +to provide a handy conduit for rna to go + + + align:start position:0% +to provide a handy conduit for rna to go +through a cell but nevertheless in this + + align:start position:0% +through a cell but nevertheless in this + + + align:start position:0% +through a cell but nevertheless in this +in this experiment when it does when + + align:start position:0% +in this experiment when it does when + + + align:start position:0% +in this experiment when it does when +when a nucleic acid does spew through + + align:start position:0% +when a nucleic acid does spew through + + + align:start position:0% +when a nucleic acid does spew through +this it blocks the the + + align:start position:0% +this it blocks the the + + + align:start position:0% +this it blocks the the +little red water molecules and similar + + align:start position:0% +little red water molecules and similar + + + align:start position:0% +little red water molecules and similar +sized ions + + align:start position:0% +sized ions + + + align:start position:0% +sized ions +are blocked and they're blocked in a way + + align:start position:0% +are blocked and they're blocked in a way + + + align:start position:0% +are blocked and they're blocked in a way +which is sensitive to the in the not + + align:start position:0% +which is sensitive to the in the not + + + align:start position:0% +which is sensitive to the in the not +only the the molecule but parts of the + + align:start position:0% +only the the molecule but parts of the + + + align:start position:0% +only the the molecule but parts of the +molecule so you can see here you've got + + align:start position:0% +molecule so you can see here you've got + + + align:start position:0% +molecule so you can see here you've got +a molecule with a poly a lego a + + align:start position:0% +a molecule with a poly a lego a + + + align:start position:0% +a molecule with a poly a lego a +part and a lego c part and you can + + align:start position:0% +part and a lego c part and you can + + + align:start position:0% +part and a lego c part and you can +actually discriminate between these both + + align:start position:0% +actually discriminate between these both + + + align:start position:0% +actually discriminate between these both +in terms of the rate at which they go + + align:start position:0% +in terms of the rate at which they go + + + align:start position:0% +in terms of the rate at which they go +through + + align:start position:0% +through + + + align:start position:0% +through +each of the parts goes through and the + + align:start position:0% +each of the parts goes through and the + + + align:start position:0% +each of the parts goes through and the +conductance so if you look down in the + + align:start position:0% +conductance so if you look down in the + + + align:start position:0% +conductance so if you look down in the +lower right hand + + align:start position:0% +lower right hand + + + align:start position:0% +lower right hand +part you'll see a 5 peco ampere to the + + align:start position:0% +part you'll see a 5 peco ampere to the + + + align:start position:0% +part you'll see a 5 peco ampere to the +minus 12 ampere 20 ampere and 120 ampere + + align:start position:0% +minus 12 ampere 20 ampere and 120 ampere + + + align:start position:0% +minus 12 ampere 20 ampere and 120 ampere +levels for these individual molecules in + + align:start position:0% +levels for these individual molecules in + + + align:start position:0% +levels for these individual molecules in +each of these spikes + + align:start position:0% +each of these spikes + + + align:start position:0% +each of these spikes +it uh is + + align:start position:0% +it uh is + + + align:start position:0% +it uh is +first + + align:start position:0% +first + + + align:start position:0% +first +the the a30 half and then the c70 half + + align:start position:0% +the the a30 half and then the c70 half + + + align:start position:0% +the the a30 half and then the c70 half +going through + + align:start position:0% +going through + + + align:start position:0% +going through +and you can see that the uh + + align:start position:0% +and you can see that the uh + + + align:start position:0% +and you can see that the uh +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +the two different conductance levels you + + align:start position:0% +the two different conductance levels you + + + align:start position:0% +the two different conductance levels you +get reproducibly going it's going + + align:start position:0% +get reproducibly going it's going + + + align:start position:0% +get reproducibly going it's going +through it typically in one direction + + align:start position:0% +through it typically in one direction + + + align:start position:0% +through it typically in one direction +first the a is in the c + + align:start position:0% +first the a is in the c + + + align:start position:0% +first the a is in the c +and uh different conductance levels + + align:start position:0% +and uh different conductance levels + + + align:start position:0% +and uh different conductance levels +different rates and then the 120 + + align:start position:0% +different rates and then the 120 + + + align:start position:0% +different rates and then the 120 +pipeline appears is in between molecules + + align:start position:0% +pipeline appears is in between molecules + + + align:start position:0% +pipeline appears is in between molecules +where you're getting the full + + align:start position:0% +where you're getting the full + + + align:start position:0% +where you're getting the full +conductance capability + + align:start position:0% +conductance capability + + + align:start position:0% +conductance capability +lots of sodium is going through + + align:start position:0% +lots of sodium is going through + + + align:start position:0% +lots of sodium is going through +and uh just like with other methods that + + align:start position:0% +and uh just like with other methods that + + + align:start position:0% +and uh just like with other methods that +we've seen + + align:start position:0% +we've seen + + + align:start position:0% +we've seen +before + + align:start position:0% +before + + + align:start position:0% +before +the use of two dimensions helps get you + + align:start position:0% +the use of two dimensions helps get you + + + align:start position:0% +the use of two dimensions helps get you +better statistical resolution here the + + align:start position:0% +better statistical resolution here the + + + align:start position:0% +better statistical resolution here the +two dimensions are the conductance and + + align:start position:0% +two dimensions are the conductance and + + + align:start position:0% +two dimensions are the conductance and +the time + + align:start position:0% +the time + + + align:start position:0% +the time +time on the vertical axis and + + align:start position:0% +time on the vertical axis and + + + align:start position:0% +time on the vertical axis and +conductance on the horizontal axis + + align:start position:0% +conductance on the horizontal axis + + + align:start position:0% +conductance on the horizontal axis +and you can see how you can discriminate + + align:start position:0% +and you can see how you can discriminate + + + align:start position:0% +and you can see how you can discriminate +different types of polymers by this + + align:start position:0% +different types of polymers by this + + + align:start position:0% +different types of polymers by this +method one molecule at a time each of + + align:start position:0% +method one molecule at a time each of + + + align:start position:0% +method one molecule at a time each of +these dots represents a single molecular + + align:start position:0% +these dots represents a single molecular + + + align:start position:0% +these dots represents a single molecular +event + + align:start position:0% + + + + align:start position:0% + +so we'll take a + + align:start position:0% +so we'll take a + + + align:start position:0% +so we'll take a +short break + + align:start position:0% +short break + + + align:start position:0% +short break +and then when we come back we'll talk + + align:start position:0% +and then when we come back we'll talk + + + align:start position:0% +and then when we come back we'll talk +about + + align:start position:0% +about + + + align:start position:0% +about +not molecular computing but + + align:start position:0% +not molecular computing but + + + align:start position:0% +not molecular computing but +designing cellular computers and + + align:start position:0% +designing cellular computers and + + + align:start position:0% +designing cellular computers and +revisit some of these same themes + + align:start position:0% +revisit some of these same themes + + + align:start position:0% +revisit some of these same themes +thanks \ No newline at end of file diff --git a/Qd-zK_1bEPM.txt b/Qd-zK_1bEPM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f159a37b1460433fd7aa7c83404bb47fa694c8c8 --- /dev/null +++ b/Qd-zK_1bEPM.txt @@ -0,0 +1,98 @@ +TAKAKO AIKAWA: So we had +two different sessions. + +One is grammar session, and +the other one is drill session. + +Grammar session is to teach or +introduce new grammar items, + +and usually, we do +this grammar session, + +we are using English, especially +for beginners classes. + +The drill session is to practice +what students have learned + +in grammar session, +so lots of drills + +and interactive activities +in class, and drills sessions + +are entirely in Japanese, even +from day two of the first year. + +And in terms of +proportion, we usually + +spend one day for +grammar session + +and four to five days for +drill sessions per each lesson. + +So for grammar +session, the students + +are supposed to read grammar +notes of the textbook, so + +each lesson, we have grammar +notes on the textbook. + +And at the same +time, each lesson + +introduces 40 to 50 +new vocabularies, + +so students are supposed to +learn those new vocabularies as + +well. + +For drill sessions, +we have a lot + +of online interactive +exercises, so students + +are supposed to go +to this online site + +and then do a lot of practice. + +So conducting drills +sessions entirely in Japanese + +it's quite challenging +for us, but I + +believe that language needs +to be learned together + +with context. + +So as a language +teacher, and then + +I believe that other +colleagues do the same thing, + +too, we bring a +lot of visual aids. + +so that the classroom becomes +more like a real context, + +and then we try to create +a so-called immersive + +environment in +class, and that way + +we can conduct +interactive drills. \ No newline at end of file diff --git a/QrzHB9_kHPE.txt b/QrzHB9_kHPE.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fda348cbded717177f09159be07b514ee40bab7 --- /dev/null +++ b/QrzHB9_kHPE.txt @@ -0,0 +1,1811 @@ +The following content is +provided under a creative + +commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR NELSON: Over the last +couple lectures through + +our consideration of a number of +somewhat difficult topics, + +including these Carnot cycles +and specific Carnot engine to + +represent them, we've tried to +define and understand a little + +bit about this very special +function, this entropy. + +Where we've got our dS. + +It's dq reversible over T. And +our treatment of reversible + +and irreversible cyclic +processes, what we saw is that + +if we go around a cycle and look +at dq reversible over T, + +then this is zero. + +Now go all the way around a +cycle, of course, this is just + +delta S for the cycle. + +And that's consistent +with the idea that + +entropy is a state functions. + +So if we go around cycle the +cycle, we have the same ending + +point, the starting point, same +state, then the change in + +the state function +has to be zero. + +But we saw that for an +irreversible path around a + +cycle, then we have +that, this gives + +something less than zero. + +And so that was expressed in +Clausius inequality that + +includes both these cases. + +And now I just want to go +through a number of + +calculations of entropy. + +How entropy changes for a number +processes, both to just + +learn more about it in general +terms and also just to see how + +it's calculated and what sort +of changes in undergoes for + +different sorts of +changes in state. + +So the first very general +example that I want to show is + +the following. + +Let's say we've got an isolated +system, and it + +undergoes some irreversible +change. + +So we'll start at one, and we'll +go irreversibly to some + +new state, two. + +OK, now we can always return the +system back to the initial + +state reversibly. + +If we do that, then we can't +keep the system isolated. + +So it won't be isolated +anymore. + +In other words, in order to +arrange things so that you + +could have a return +along a reversible + +path, it can't be isolated. + +In some sense you know that, +because when it was isolated + +it spontaneously irreversibly +went from one to two. + +And example would be ice melting +at some temperature + +that might be higher than +the freezing point. + +So you've got solid ice, but the +temperature is above zero + +degrees Celsius, so irreversibly +it'll melt. + +Systems isolated, it'll melt. + +Then you could put the system +in contact with a cold + +reservoir reversibly re-freeze +the water to form ice again. + +But of course to do that you +couldn't keep it isolated. + +You need to have it in contact +with a low temperature bath. + +But again, this is +just completely + +general at this point. + +It's some irreversible process +returned then along a + +reversible path. + +So let's just look +at what happens. + +So here's our path B. +Along path A, well + +it's an isolated system. + +So the heat exchanged is zero. + +And then, for the cycle based +on the Clausius inequality + +expressed here, the integral +around the cycle of dq over T + +in general, it's less than +or equal to zero. + +If there was an irreversible +process involved, then in + +fact, it'll be less than zero. + +I'll write it here in the more +general case, but we know what + +it's really going to be with +the irreversible step. + +Well, so we can write this +as the integral of dq + +irreversible over T, going from +state one to state two. + +Oh, let me rewrite +this down here. + +So around the cycle, dq over +T, it's integral from state + +one to two of dq irreversible +over T, plus the integral from + +two back to one of dq reversible +over T. And of + +course, we know that that's less +than or equal to zero. + +But this, we know is zero, +right, because this + +irreversible step is +taken in isolation. + +The system is isolated. + +We've already seen that there's +no heat crossing the + +boundary of the system. + +So we just have this. + +So of course this dq reversible +over T from two to + +one, that's, what now we've a +reversible path, so that's + +just the entropy at the delta +S going from two to one. + +It's S1 minus S2 it's delta S, +we can write it as delta S + +backwards, right, we're +going back along + +that reversible path. + +Which is of course negative +delta S forward. + +Because around the whole cycle +delta s has to be zero. + +So what that says is delta S +forward is greater than or + +equal to zero. + +That's interesting. + +What that's saying is -- +remember, we didn't specify + +the process. + +It's just for any completely +general irreversible process. + +For any such process, for any +spontaneous process, this is + +going to be the case. + +So in other words, for an +isolated system, delta S tells + +us the direction of spontaneous +change. + +In particular, for the isolated +system, delta S is + +greater than zero for something +that's irreversible. + +Delta S equals zero for +something that's reversible, + +and delta S is never +less than zero. + +In a sense, this is a direct +consequence of the Clausius + +inequality. + +That's a pretty useful result. + +So remember when we started this +whole discussion, I tried + +to emphasize that the first law +of thermodynamics told us + +about conservation of energy. + +But it didn't tell us which +way something would go + +spontaneously if you just left +the system to its own devices + +under certain conditions. + +This is telling us that. + +We can tell which way the system +will evolve in which + +direction it'll go. + +This is for an isolated system +and we'll generalize this in + +subsequent lectures. + +Now, let's look at what +happens if the + +system isn't isolated. + +So now let's go from one +to two not isolated. + +So of course, delta S I'm +going to specify for the + +system for reasons that'll soon +be obvious is S2 for the + +system minus S1 for +the system. + +Of course it doesn't depend on +the path, even though to + +calculate it, we need to +find a reversible path. + +Just to add emphasis to what we +just did here, of course, + +it was the same thing. + +In order to calculate delta S +along that irreversible path + +for that irreversible process +we needed to construct some + +reversible path. + +And what we did is imagined +the reversible path going + +backwards and then said, OK, +fine then delta S for the + +irreversible process must be the +opposite of delta S that + +we calculated along the + +reversible bath going backwards. + +The point is that to calculate +delta S in either direction, + +we needed to construct +some reversible path. + +All right, and of course +it'll be the same here. + +Now, in this case since the +system isn't isolated, that + +means heat's going to flow +across the boundary. + +So that means heat is going +between, it's being exchanged + +between the system and +the surroundings. + +So what's happening to +the surroundings? + +Generally, we've worry a lot +about the system, but not much + +in recent discussions about +the surroundings. + +But delta S surroundings +must be something. + +We could calculate it. + +And that's depends +on the path. + +Not because it isn't the state +function in the surroundings, + +of course it is, but because +depending on the path, the + +final state of the + +surroundings will be different. + +After all, depending on how much +heat got exchanged, the + +surroundings got more or +less of that heat. + +Work might have been done +on the surroundings. + +So the surroundings are going +to respond, are going to + +change also, when the system +changes in this way and it's + +not isolated. + +And how the surroundings change +will depend on what + +path was taken. + +And you've seen that before +in calculating things like + +pressure, volume, work along +different paths. + +Where you calculated delta u for +the system and saw that it + +was the same for different paths +but q and w were not the + +same for the system, and +therefore, of course, not for + +the surroundings either. + +So let's just consider +an irreversible path. + +And in order to think about +what happens to the + +surroundings, let's take the +entire universe which consists + +of the system and the +surroundings -- that is a big + +isolated system, because +it's everything. + +So it's not somehow in contact +with another additional body + +or universe. + +We can treat the +entire universe + +as an isolated system. + +So, we're going to think about +the entire universe. + +We can think about it as +an isolated system. + +Great. + +And we know that delta S for +an isolated system, for a + +spontaneous process, is +greater than zero. + +That's right there. + +So delta S for the universe +which is delta S for the + +system plus delta S for the +surroundings, and I'll specify + +since we're considering an +irreversible process, specify + +that, it's greater than zero. + +The whole thing happened +spontaneously, and the whole + +universe is an isolated +system. + +So if we wanted to, we can +write that delta S + +irreversible for the +surroundings must be bigger + +than minus delta S for the +system in order that there sum + +be positive. + +All right? + +Now, if we consider a reversible +process, then of + +course we already know what +happens for an isolated system + +in a reversible process, +delta S is zero. + +So delta S in this case of the +whole universe, which is delta + +S for the system plus delta S +for the surroundings in the + +reversible case must +be equal to zero. + +In other words, delta S of the +surroundings in the reversible + +case is exactly the opposite +of delta S of the system. + +Delta S of the system is the +same in either case because + +reversible or irreversible, +we're specifying the system, + +goes between the same states, +but what happens to the + +surroundings is different +in the two cases. + +So one way of recasting this +statement or the Clausius + +inequality is the entropy +of the whole + +universe never decreases. + +Of course, in some sense, +that's obvious from this + +statement, since we're +considering the universe an + +isolated system. + +So the entropy in any process +can, it can, the change in + +entropy can either be zero or +positive and never negative. + +So entropy off the whole +universe never decreases. + +That's actually a really quite +profound conclusion. + +All sorts of philosophical and +other consequences of it that + +are sometimes considered in +things like evolutionary + +biology and other things. + +And how things can change +altogether an + +entire system of things. + +Now, I'd like to just go through +a few calculations of + +delta S for common processes. + +We've seen a few general +features of entropy. + +Let's calculate it +for a few things. + +So calculations of +delta S. And we + +know the general procedure. + +Whatever the process is, we're +going to need to find + +reversible paths, and along a +reversible path then, we'll be + +able to calculate it. + +One, let's just take two +pieces of material at + +different temperatures. + +The entire system is going +to be isolated. + +And then let's connect them. + +And then let's connect them. + +Put some material +between them. + +So now heat can flow from +one to the other. + +And you know what's going to +happen which is if they start + +out at unequal temperatures, and +you wait a little while, + +eventually they're going +to wind up at the same + +temperature. + +In other words, you +know the direction + +of spontaneous change. + +So let's just see what +happens to delta S. + +So isolated system, so there's +no work being done. + +There's no heat that's +being exchanged. + +So delta u is zero. + +What's dS? + +Well it's just the sum of the +changes in entropy for the two + +sub-systems the two +separate pieces. + +So it's dq1 over T1 plus dq2 +over T2, I think there's a + +type in your notes. it's plus +not minus of course. + +But in this case, dq1 is just +the opposite of dq2. + +Because whatever heat is flowing +into T1, into this + +block, is coming out of this +block, or vice versa, + +depending on which +one is hotter. + +So this is just equal to dq1 +times one over T1 minus one + +over T2, which is T2 minus +T1 over T1 times T2. + +So that's dS, and then we could +integrate it to get the + +delta S, but this is sufficient +for what I'd like + +to illustrate, which is just +the sign of things. + +We know dS must be greater than +zero for the spontaneous + +change that's going to occur. + +So let's just make sure that +common sense prevails here. + +That says if T2 is greater than +T1, right T2 is hotter. + +Then dq must be positive, so +this is positive, this is + +positive, dS we know +has to be positive. + +So, it says T2 is hotter. + +This being positive means heat +is flowing in from this one to + +this one, from the hotter +to the colder body. + +So it looks right. + +If T2 is lower than T1, if this +one is colder, then in + +order for dS to be positive, +which it has to be, this + +better be negative. + +In other words, again heat is +going to flow from the hotter + +toward the colder, into +the colder body. + +So, as promised, the condition +that dS must be greater than + +zero, guides us and tells us the +direction that spontaneous + +change is going to occur. + +We can tell just from this +condition which way things + +have to evolve. + +All right, let's try another +pretty simple process. + +Let's just take a gas in some +volume V and over here is + +going to be vacuum of equal +volume, and we're going to + +remove the barrier. + +You know what's going to happen +spontaneously, right? + +The gas is going to fill the +available volume once it + +becomes available. + +So this, we'll make this a Joule +expansion, and we'll + +make it an ideal gas. + +So the process is one mole of +gas at our initial volume and + +some temperature, and we'll make +this adiabatic, and this + +goes to one mole of gas at a new +volume, 2V and at the same + +temperature. + +All right, so there's +no work done. + +It's adiabatic. + +There's no heat exchanged. + +Delta u is zero. + +Everything's zero. + +Almost everything is zero. + +What isn't zero? + +STUDENT: Entropy. + +PROFESSOR NELSON: Entropy. + +It's going to tell us which +way this whole thing goes. + +So this is an irreversible +process. + +In order to calculate delta +S we need to construct a + +reversible path along +which this can go. + +So here's a way to do it. + +We could compress it back, +isothermally and reversibly. + +Just like the example I gave, +the general example, where I + +mentioned the ice melting. + +In that case, it won't +be adiabatic. + +We'd have to put it in +contact with a heat + +source of some sort. + +So reversible process. + +We could compress it back to +volume V, isothermally, and + +reversibly. + +Let me say, there's no -- we +wouldn't have to consider this + +process in reverse. + +Of course, we could also +consider the forward process + +in the presence of some heat +source with isn't isolated and + +do this, but let's just consider +the compression. + +So, OK, now we'll have +the -- well, once + +again, delta u is zero. + +It's an ideal gas. + +There's no temperature change. + +But this time q and w aren't +going to be zero. + +They're going to be some +finite numbers that are + +opposites of each other. + +Because we're no longer +isolated. + +So let's just write out delta +S to go backward is dq + +reversible over T, and +that's minus dw + +over T, not zero anymore. + +And where we're going is from +2V to V, we're compressing, + +and it's an ideal gas. + +So this is the same as p dV, but +it's p dV over T which is + +the same thing as going from +2V to V. Now we're going to + +replace this with RT over V, +and the T's will cancel. + +So it's R dV over V going from +2V to one V. So it's just R + +times the log of 1/2. + +So now we've just calculated +the value of delta S by + +constructing this +reversible path. + +Now this is delta S backward. + +To do the compression, so of +course delta S forward is just + +the opposite of that. + +So, delta S forward +is R log 2. + +Reassuringly, that's +a positive number. + +So this process that we +considered originally, this + +irreversibly process in this +isolated system, remember, for + +the irreversible expansion +we considered the system + +isolated, Happened +spontaneously, and of course + +you know that's the case. + +Now, I'll just mention, and +later on we'll go into this in + +considerably more detail, but +I'll just mention at this + +stage through a little bit of +sort of foreshadowing that + +everything we've discussed so +far about entropy is with a + +macroscopic picture. + +We started with heat engines +and Carnot cycles and + +macroscopic processes, +reversible and irreversible + +processes and so on. + +But there's a, and that's +certainly the way it was all + +formulated originally. + +Part of the power of +thermodynamics is that it + +doesn't depend on a specific +microscopic model of matter. + +That said though, we +have a pretty good + +microscopic model of matter. + +We know about atoms and +molecules, and in fact there + +is an entirely microscopic +formulation of entropy that + +has to do with disorder and +the number of available + +states, microscopic states +available to a system. + +So I'll just state what +we'll see in much more + +detail later on. + +Which is in microscopic terms, +it's going to turn out that + +the entropy of a system can be +given by R over Avogadro's + +number times the log of the +number of distinct microscopic + +states that are available +to a system. + +Right so in this isolated +system, when we double that + +volume, each molecule suddenly +has twice as many states + +available to it. + +You could formulate that +in a lot of ways. + +You can sort of divide up the +volume into tiny little + +molecule-sized cubes and realize +well, now, there are + +twice as many of them. + +Now if I have one molecule, the +number of states doubles. + +If I have n molecules, the +number of states goes + +up by 2 to the n. + +Because for each one of the +molecules, I can select any + +one of those states, and +then the next one I + +can select any one. + +So you have this enormous +increase in + +the number of states. + +So delta S in this case looks +like R over NA log of 2 to the + +power NA, it's Avogadro's +number, + +for a mole of molecules. + +This can come out +and cancel this. + +There's our R log 2 result. + +But the point I'm making here +is that could actually be + +derived from entirely +microscopic consideration. + +We haven't gone through +that yet. + +We've done entirely macroscopic +thermodynamics so + +far, but we'll do a little bit +of treatment of statistical + +mechanics, is what is called +the whole microscopic + +formulation of entropy +in thermodynamics. + +And that's a really important +fundamental result. + +And we'll get to it in much +more detail in a while. + +But for now, I just want to +continue calculating entropy + +changes for a few more +kinds of processes. + +So, how about if we have two +different substances and we + +mix them, entropy of mixing. + +So, we start with some number +of moles of substance A in + +some volume VA, and some other +number of moles of substance B + +in volume VB, separated. + +And then we remove the barrier, +of course we know + +they're going to mix. + +So we'll have some total number +of moles, nA plus nB, + +and they'll be filling some +total volume, which is the sum + +of the two original volumes. + +Certainly this is what +we expect to happen + +spontaneously. + +So are process is nA moles of A, +gas, initial volume VA and + +T, plus nB of substance B, I +think this is miswritten as A + +there in your notes. + +Gas VB and T goes to nA moles of +A plus nB moles of B. Gas, + +total volume and T. And +we'll have constant + +temperature and pressure. + +Well, there was no +p v worked done. + +The temperature didn't change +and it's ideal gases, so delta + +u is zero, but what +about delta S? + +Well again, to calculate +it, we need to find + +a reversible path. + +This is irreversible if we just +remove the barrier and + +let it all go. + +But we could at least imagine +a reversible path, and we + +could actually construct this +for the right substances. + +We could imagine that we can +find some sort of piston here. + +And we're going to prepare +to push it inward, with a + +membrane that's permeable +only to b. + +And over here we could set up +the exact same thing, but this + +one's permeable only to a. + +And then we could just push them +to recover this state. + +And we can do it reversibly. + +So we could construct a +reversible process that does + +the reverse of this. + +And in this case, it'll be +isothermal still, constant + +pressure, reversible compression +of the two gases. + +So, reversible compression +and demixing. + +All right, so what happens? + +Well, of course, our delta S +of demixing is going to be + +minus delta S of mixing. + +Delta u of demixing +is still zero. + +Temperature didn't change, ideal +gases, and there's some + +reversible work and heat. + +So dw in this reversible case, +is just minus pA dVA minus pB + +dVB, the infinitesimal amount +of work done as these things + +are gradually moved +toward each other. + +So delta S for demixing, of +course it's dq reversible over + +T, but just like we did right +there, of course, in this case + +that's just negative dw. + +So it's integral from V to VA, +right, were compressing. + +So for substance a, we're going +to go back to there. + +It was occupying the whole +volume, and then it's going to + +end up in only part +of the volume, VA. + +pA dVA over T. Same thing for +B, going to volume B, pB dVB + +over T. And now we can +substitute for pressure, + +right? pV is nRT, so it's nA +times R log of VA over V plus + +nB of R log of VB over V. + +Now, so this is a suitable +answer, but I'm going to make + +if a little easier by putting +in terms of mole fractions. + +So, mole fractions, of course, +XA is nA over n, and XB is nB + +over n and XA is also equal to +VA over V and XB is equal to + +VB over V for ideal +gases, right? + +The molar volumes +are the same. + +We're at the same temperature +and pressure. + +So that immediately gives us the +delta X of demixing is nR + +times XA log XA plus +XB log XB. + +And of course delta S of mixing +is the opposite of + +this, minus nR XA log +XA plus XB log XB. + +Now XA and XB are +mole fractions. + +They are between zero and +one, So their log + +rhythms are both negative. + +There's a negative sign. + +So delta S of mixing +is positive. + +That's reassuring. + +That tells us as we expect that +the mixing should happen + +spontaneously and irreversibly +when we remove the barrier. + +Any questions so far about how +we're going about these + +calculations of delta S? + +OK, let's just do a couple +more examples. + +Here's a really straightforward +one. + +What if we just heat stuff +up or cool it down. + +It happens all the time, but +it's pretty important, right? + +So let's just heat or cool +at constant volume. + +So, we're going to go from +substance A at T1 and some + +volume going to substance +A at T2 at some volume. + +We can do this. + +Delta S is integral of dq +reversible over T. Going from + +T1 to T2, but we know how +to do this, right? + +It's the heat that we need. + +It's just given by the constant +volume heat capacity + +times the change +in temperature. + +So this is just T1 to T2, Cv dT +over T. And that is just Cv + +times the log of T2 over T1 if +Cv is temperature independent. + +That's not always the case. + +Usually if it's not too big an +excursion of temperature then + +it's a reasonable +approximation. + +So that's straightforward. + +By the way, notice that delta +S is greater than zero if T2 + +is greater than T1. + +In other words, if we heated +it up, delta S is positive. + +Notice also delta S is +less than zero if T2 + +is less than T1. + +Delta S is negative +if we cooled it. + +Now, under certain conditions +we've seen that delta S can't + +be negative. + +Why can it be negative here? + +STUDENT: [UNINTELLIGIBLE]. + +PROFESSOR NELSON: +Yes, I heard it. + +It's because the system +isn't isolated, right. + +It was for the isolated system +that delta S is always greater + +than or equal to zero. + +And you know, for the whole +universe entropy never + +decreases and so on. + +In this case, though, you know +we're taking a system and + +we're putting it in contact +with a cold bath + +and cooling it down. + +It's certainly not isolated. + +Heat is being exchanged. + +It's going from the system to +the surroundings, to the bath. + +So it's fine. + +Delta S can be negative. + +What would happen if we +calculated delta S of a new + +entire system consisting +of the original system + +plus the heat bath? + +What would delta S be then? + +We already kind of did that with +those two blocks, T1 and + +T2 in an isolated systems. + +What do you think is +going to happen? + +In other words, if we call our +system the stuff that is put + +in contact with the heat bath, +well OK, then we've seen delta + +S can be plus, can be positive +or negative. + +Now let's call our system the +original system plus the heat + +bath, and we'll put them all in +some isolating box, that's + +thermally isolating and so on. + +And now we'll put our original +system, which is now sort of a + +sub, part of the system, and +it's now going to be in + +contact with the cold bath. + +The bath that it's in contact +with is colder than it is. + +That's why its delta S +is less than zero. + +But what's delta S to be for +the entire new system + +including the cold bath? + +STUDENT: Wouldn't it +greater than zero? + +PROFESSOR NELSON: Yes, it's +going to be positive, because + +it's an isolated system +and something happened + +spontaneously in it, namely the +original system got cooler + +and presumably the heat +bath got at least + +a little bit warmer. + +And it happened spontaneously, +which immediately means delta + +S had to be positive for that +entire assembly, of you know + +the original system +plus the bath. + +Here's another important +sort of process. + +Reversible phase change, we'll +melt something or freeze it. + +How about water -- liquid +100 degrees Celsius + +one bar goes to water. + +Gas 100 degrees Celsius +one bar. + +Well in that case, you know +what the heat is. + +It's just the delta H of +vaporization, right, at + +constant pressure. + +So there's nothing really +much to calculate here. + +Delta S of vaporization for H2O +at 100 degrees Celsius is + +just q of vaporization over the +boiling temperature, which + +is delta H of vaporization over +the boiling temperature. + +So that was easy. + +One last thing. + +What if we want to calculate the +entropy of melting or some + +phase transition not +at equilibrium? + +In this case it's at equilibrium +because it's water + +and water vapor at 100 degrees +Celsius and one + +atmosphere or one bar. + +So it's at its boiling point. + +But what if it isn't at +its boiling point? + +So what if instead, let's take +H2O, liquid, at minus ten + +degrees Celsius and one +bar so it's cold. + +It's going to freeze. + +So it's going to turn into +solid water at minus 10 + +degrees Celsius and one bar, +we're going to have it be + +isothermal. + +Now you know that's going to +happen spontaneously, and it's + +irreversible. + +Irreversible, which means we +can't just straight away + +calculate delta S along +this path because it's + +irreversible. + +But what we can do, just like +we've done before for making + +cycles, we can make some other +set of events that are all + +reversible. + +We can construct a reversible +pass that will get there. + +How do we do it? + +Well you know for the phase +change, for the freezing to be + +reversible, it has to happen at +zero degrees Celsius right. + +You know that's where +you have reversible, + +freezing and melting. + +Reversible equilibrium between +liquid and solid water. + +So surely that's got to +get involved here. + +H2O liquid zero degrees +Celsius, one bar, in + +equilibrium with H2O solid at +zero degrees Celsius, one bar. + +Whatever reversible path we +construct that's going to go + +from liquid to solid water, +somewhere along the set of + +steps, that better +be one of them. + +So now what we need to do is +go from liquid at minus 10 + +degrees Celsius and one bar to +liquid at zero degrees Celsius + +and one bar. + +That's called heating. + +We have to heat it. + +And here we have to cool it. + +And we've already seen all these +three processes, right. + +So for the phase change, +it's reversible now. + +This is just delta +heat of fusion. + +Great. + +Because this is now +reversible. + +This is going to +be reversible. + +This is going to be reversible. + +Great. + +So dq reversible, it's going +to be the heat capacity at + +constant pressure, the example +we did before it was constant + +volume for the liquid dT. + +Here, dq reversible is going +to be Cp solid, dT. + +Those won't be the same right? + +It's one thing to say the heat +capacity of something doesn't + +change over some small excursion +in temperature, but + +it's another thing when the +thing actually changes phase. + +The heat capacity of the +solid and the liquid + +won't be the same. + +So this we can just finish up in +a jiffy, because we're just + +going to add the three things. + +So delta S is delta S of +heating, minus, I think + +there's a plus that should be +a minus there, minus delta S + +of fusion because it's going in +the direction of freezing + +the way we've written it. + +Plus delta S of cooling. + +So integral from T1 to the +melting point of Cp of the + +liquid dT over T, minus delta +H of fusion over the melting + +temperature. + +Plus the integral going from the +heat of the temperature of + +melting to T1 of Cp of +the solid dT over T. + +That's it, all right? + +So delta S is minus delta H of +fusion over T. That's what it + +would be for just the reversible +phase change + +happening at zero +degrees Celsius. + +And then there's this additional +part which is, we + +can write it from T1 to melting +point of Cp of the + +liquid, minus Cp of the +solid, dT over T. + +Now usually we can assume that +these will be temperature + +independent in their +own phases. + +So we can usually write this +as minus delta H of fusion + +over the melting temperature +plus Cp of the liquid minus Cp + +of the solid log of T +of fusion over T1. + +Any questions? + +What did we do? + +We constructed a reversible path +going from here to here + +and calculated delta S that way, +and of course that has to + +be the same as delta S in the +one irreversible step. + +All right, more on entropy and +its consequences for how to + +figure out what happened +spontaneously next time. \ No newline at end of file diff --git a/QyJkYF-L1Kg.txt b/QyJkYF-L1Kg.txt new file mode 100644 index 0000000000000000000000000000000000000000..c1122a98e6271a8b43b5e15f6be880b3fe3ae726 --- /dev/null +++ b/QyJkYF-L1Kg.txt @@ -0,0 +1,1346 @@ +PROFESSOR: Resume by going back +to our one-dimensional + +body that has undergone some +elastic deformation. + +And what I would like to do now +is to distinguish between + +displacement of an object and +fractional change of length, + +which turned out to be measured +by the same thing, + +that thing that we're +going to name strain + +when properly defined. + +OK, here is our one-dimensional +case. + +And we said that originally some +point, P, at a location x + +gets mapped to a point P prime +that is at x plus some + +displacement U. So this is the +displacement vector U. + +Our point Q, which is originally +at some location x + +plus delta x, where delta x +is the original separation + +between P and Q, gets mapped to +a point Q prime, which is + +going to be equal to a whole +collection of terms. + +It's going to be equal to x +plus delta x, the original + +location, plus the linear +variation of U with x that has + +to go U times x plus delta x. + +And if we simplify this a little +bit, Q prime is going + +to be at a location, factoring +out x plus delta x, x plus + +delta x times 1 plus e. + +AUDIENCE: Is e represented +here? + +PROFESSOR: e is the linear +relation between displacement + +U and position along the body. + +OK, so what has happened here? + +The relative change of length +is going to be P prime + +Q prime minus PQ. + +And if we just substitute in +our two expressions, the + +relative change of length is +going to be equal to delta x + +times 1 plus e minus delta x. + +This is the relative +change of length. + +And I should label this such. + +That's going to be equal to +delta x times 1 plus e minus + +delta x divided by delta x. + +And that simply going to be +e, which is equal to delta + +U over delta x. + +And that is what we +define as strain. + +And that is a dimensionless +quantity. + +Because it has units of +length over length. + +All right, how can we patch this +one-dimensional sort of + +behavior up to a +three-dimensional situation? + +What we are saying in this +one-dimensional case is that + +the displacement of a particular +point P varies + +linearly with position +in the body. + +So let's generalize that into +three dimensions by saying + +that the component of +displacement U1-- and this is + +going to look like an +algebraic identity. + +It's going to be the way in +which U changes with x1 times + +the position x1. + +So this is saying that the +displacement will vary + +linearly with x1. + +And the rate will be du1 dx1. + +But also U1 is going to change +with the coordinate x2. + +And the coefficient there +will be du1 dx2. + +And there's going to be a third +term that will be the + +way in which U1, the x1 +component of displacement, + +changes with x3 times the +position in the body x3. + +So this is saying exactly the +same thing that we did in one + +dimension, that displacement +depends linearly with + +position, except that +there's now three + +coordinates for position. + +And the displacement will change +with an increment of a + +change in position along each +of those three axes. + +Similarly, we can say that U2 +is going to be equal to the + +way in which U2 changes with x1 +times the position x1, the + +way in which U2 changes with x2 +times the coordinate within + +the body x2, and the same for +U2 dx3 and the actual + +positional coordinate x3. + +And so, in general, we're going +to propose that the i-th + +component of displacement is +given by the way in which + +displacement changes with +x sub j times x sub j. + +Or you could do the same thing, +not in terms of actual + +displacement, but differences in +displacement, the same way + +we could define strain as the +fractional change of length of + +our line segment on the +elastic band or, + +alternatively, as the +shift in position. + +So we could define it also as +the difference in distances or + +displacements let +me call them. + +And that really is +a trivial change. + +We'll say the change of a length +along x1 delta U1 is + +going to be the way in which U1 +changes with x1 times delta + +x1 plus the way in which U2 +changes with x1 times the way + +in which U1 changes with x2 +times delta x2 plus the way in + +which U1 changes with x3 times +delta x3 or, in general, that + +the fractional change in length +is going to be equal to + +dui dxj times delta xj. + +All right, so what we're going +to define now is dui. + +Dxj will be defined as something +like strain. + +It's not exactly strain yet. + +And this is going to be a +measure of deformation. + +I'm hedging my words because of +something that we'll want + +to impose upon the proper +strain tensor. + +But first, let's see what these + +three-dimensional terms mean. + +And to see that, let me look +at a place within the body. + +And I'm going to look at a line +segment that goes between + +a P and Q that is oriented +along x1. + +And I'm picking that +deliberately. + +Because I want to keep things +simple and isolate one of + +these terms so we can identify +its meaning. + +So let's say here we have two +points P and Q separated by a + +distance delta x1 prior +to deformation. + +And now we squish the body. + +And what happens is that +P will move to + +a position P prime. + +Q will move to a position +Q prime. + +And this will be the new line +segment, P prime Q prime. + +This will be the original +delta x1. + +To that we're going to +tack on an instrument + +which is delta U1. + +But then there will also +be a delta U2. + +And clearly what has happened is +that the length of the line + +segment P prime Q prime +has changed. + +But also the orientation of the +line segment has changed + +by an angle, which I'll +define as phi. + +So again, we have +a line segment. + +We deform the body. + +P is displaced. + +Q is displaced. + +The component of that line +segment along x1 has changed + +in length by an amount +delta U1. + +The coordinate along x2 will +change by an amount delta U2. + +So we not only change +the length. + +But we rotate the +line segment. + +We can express these in terms of +our general relation that I + +proposed a moment ago. + +Delta U1 is going to be equal +to du1 dx1 times delta x1. + +And that is going to be given +by the element epsilon 1, 1 + +times delta x1. + +The value of x2 was going +to be equal to du2 + +dx1 times delta x1. + +And that's going to be +by definition e2, + +1 times delta x1. + +And the reason this is so simple +is that I initially + +picked the line segment which +was parallel to x1. + +So not all of the four terms +that would be present in the + +x1, x2 system have come in. + +So there's no contribution of +delta x2 because of the fact + +that I've picked this +special orientation. + +OK, the fractional change of +length resolved on x1 is going + +to be, well, it's going to be +exactly delta x plus delta U1 + +quantity squared, it's going +to be this horizontal line + +segment, plus delta U2 +quantity squared all + +to the power 1/2. + +And now I'm going to say that +delta U2 is negligible + +compared to this big delta +x plus delta U1. + +And I'll say that this is +approximately equal to delta x + +plus delta U1, OK, just taking +the whole works outside of the + +square root sign. + +So delta U1 over delta x1 is +going to be equal to the term + +e1, 1 from this expression +here. + +So the term e1, 1 represents the +tensile strain along x1. + +So we can see how these +derivatives are going to enter + +into changes of length. + +The P prime Q prime has also +been rotated by phi. + +And we can say exactly what that +is that the tangent of + +phi is going to be given exactly +by delta U2 divided by + +the original length of the line +segment delta x1 plus the + +little increment of displacement +along x1. + +And this is-- + +I'll walk down here +so I can see it. + +This is delta U1. + +This is delta U2 over +times delta x1-- + +sorry, I can't see what I've +got down here-- delta + +U1 plus delta x1. + +OK, so it's the amount of +displacement along x2 over the + +original line segment delta +x1 plus the change in + +displacement delta U1. + +And clearly delta U1 can be +claimed to be small with + +respect to delta x1. + +So this is approximately equal +to delta U2 over delta x1. + +And tangent of phi is going +to be tangent of + +a very small angle. + +So this will be delta +U2 over delta x1. + +And so this angle phi is, for +small strains, going to be + +equal to delta U2 +over delta x1. + +And that is the definition of +our element of strain e1, 2. + +So e1, 2 corresponds to a +rotation of a line segment + +that was originally parallel to +x1 in the direction of x2-- + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: e2, 1, I'm sorry, e2, +1, yeah, along x1 in the + +direction of x2. + +And that is counterintuitive as +I have just demonstrated. + +e2, 1 is a rotation of a line +segment along x1 in the + +direction of x2, which is just +the reverse of the subscript. + +So eij, a general off-diagonal +element of the array eij, is + +going to be a rotation of a line +segment initially along x + +sub j in the direction +of x sub i. + +And for very small strains, +numerically that term eij will + +give an angle in radiants. + +AUDIENCE: For the equation you +have over there, should it be + +delta x plus delta x2? + +PROFESSOR: No, I would +say this-- + +AUDIENCE: Because aren't +you saying delta U1? + +PROFESSOR: Oh, OK, +you're right. + +Yeah, I didn't take the +difference here. + +AUDIENCE: Delta U1 is basically +negligible? + +PROFESSOR: Yep, yep, so I'm +saying that that [INAUDIBLE] + +should be delta x1-- + +AUDIENCE: Plus delta U2? + +PROFESSOR: --plus delta U2. + +You're right. + +No, I'm throwing this out. + +And that's right. + +So I'm saying that this +is essentially delta + +x1 plus delta U1. + +I'm saying that this +is negligible. + +So strictly speaking the +distance between P prime and Q + +prime is the square +root of this + +squared plus this squared. + +But if this thing is tiny, P +prime Q prime is essentially + +going to be this distance, +delta x1 plus delta U1. + +So that's right. + +OK, so we have something that +looks like it measures + +deformation. + +But I would like to ask if this +is a suitable measure of + +deformation. + +And I would like to show that, +unless the tensor eij is + +symmetric, that we have included +in our definition of + +strain rigid body rotation as +well as true deformation. + +So in order to demonstrate that, +what I'm going to look + +at is a case where we have +actually, by the way in which + +we apply a stress to the +material, actually done + +nothing more than rotate +x1 to x1 prime and + +rotate x2 to x2 prime. + +And in general, for a real +amount of deformation, that is + +something that is +going to happen. + +Let's say I decide to deform +this eraser in shear before + +your very eyes. + +And I try shearing it. + +Nothing much has happened. + +And I squeeze a little harder. + +And finally, I've got it +wrestled down into an + +orientation like this. + +And when I finished, this +was the original + +position of the eraser. + +Here's x1. + +Here's x2. + +And by the time I've wrestled it +around to a deformed state, + +it sits down like this, maybe +deformed a little bit. + +But would you say that this +angle here is a measure of + +deformation? + +No, that's clearly a rigid +body rotation. + +And what I would intuitively +do, if I wanted to measure + +true deformation, if this were +the original body and after + +deformation it went to a +location with some deformation + +to be sure but this has +been rotated to here. + +This has been rotated down. + +And I wouldn't want to say +that this is a measure of + +deformation. + +This would be e1, 2. + +What I would want to do +intuitively would be to + +position the body symmetrically +between the axes + +and then say that this is a +measure of shear strain. + +So let me show you now in a more +rigorous treatment that, + +if there is a component of rigid +body rotation, let me + +show you what a rotation of the +coordinate system to a new + +orientation x1, x +prime would do. + +So let's say that this is +an original point Q1. + +And after deformation, it moves +by a rotation phi that's + +equal to e2, 1 to a new +location Q1 prime. + +Let's suppose that this +is a position Q2. + +And after what we think is the +deformation, this moves to a + +location Q2 prime. + +And this would be e1, 2. + +That's equal to minus phi. + +This is e2, 1. + +And that's equal to plus phi. + +So what we would do is +like to get rid of + +that rigid body rotation. + +And what I'll do is to show +that, if we have a point + +that's out at the end of a +radial vector, R, which has + +coordinates xi, x1, x2, x3, and +if we have a displacement, + +which is absolutely +perpendicular to that radial + +vector, that this would +be characteristic + +of rigid body rotation. + +And I will say that, if Ui is +perpendicular to the radial + +vector xi, then U.R should +be equal to 0 for + +every position xi. + +So if we just multiply this out, +this is saying that Ui Ri + +should be equal to 0 for +rigid body rotation. + +And let's simply carry +out this expansion. + +And I will have then eij xi xj +forming this dot product. + +And that is going to be 0 for +a rigid body rotation. + +And if I expand this, this will +contain terms like e1, 1 + +times x1 x1 plus e2, +2 times x2 x2 plus + +e3, 3 times x3 squared. + +And then they'll be cross-terms +e1, 3 plus e3, 1 + +times x1 x3 plus e1, 2 plus e2, +1 times x1 x2 plus e2, 3 + +plus e3, 2 times x2, x3. + +And my claim now is that, if +this represents rigid body + +rotation, then that +should be 0. + +That is to say the displacement +is absolutely + +perpendicular to the radius +vector for small + +displacements. + +This must be 0 for all xi. + +And the only way that's going +to be possible for any value + +of x1, x2, x3 is that each +of these six terms vanish + +individual. + +It's the only way I'm going to +be able to get the whole thing + +to disappear for any value +of coordinate x1, x2, x3. + +So we're going to have to then +have e1, 1 equals e2, 2 equals + +e3, 3 equals 0. + +All the diagonal terms are +going to have to be 0. + +In order to get the fourth term +to vanish, I'm going to + +have to have e1, 3 equal to the +negative of e3, 1 and e1, + +2 the negative of e2, 1 and e2, +3 the negative of e3, 2. + +So what is this going to look +like for the part of the e + +tensor that corresponds to +rigid body rotation? + +The diagonal terms are +all going to be 0. + +And the off-diagonal terms are +going to be the negative of + +one another. + +So this is e1, 2. + +e2, 1 would have to be +equal to minus e1, 2. + +e3, 1 would have to be equal +to the negative of e1, 3. + +And so we will have something +like this. + +So this suggests that our +definition of the true + +deformation, which will be +a tensor epsilon ij-- + +I bet you kind of guessed I was +going to call it epsilon + +and not E. I can write this +as a sum of two parts. + +I'll turn that around and say +I'll write epsilon ij plus + +another three by three array +omega ij is equal to the + +tensor eij. + +That's a novel idea. + +This is addition of two tensors +element by element. + +And if I do that and define +epsilon ij equal to 1/2 of eij + +plus eji, so for the diagonal +elements that is going to take + +1/2 of e1, 1 plus e1, 1. + +And that's just going to give +me e 1, 1 back again. + +And I'm going to define the +terms omega ij as 1/2 + +of eij minus eji. + +And if I do that, the resulting + +tensor will be symmetric. + +OK, so from tensor eij we can +split it up into two parts and + +a part omega ij. + +And I won't bother +to write it out. + +But you can see that omega ij +plus eij is going to be equal + +to eij minus 1/2 of 2eij +minus 1/2 of 0. + +And that's just going +to be eij. + +So this plus this is indeed +going to give + +me the tensor eij. + +So given a tensor eij, which +is not symmetric, I will + +define eij as the sum of two +parts, a tensor epsilon ij, + +which is true strain, and a part +omega ij, which is rigid + +body rotation. + +And now at last we have a +satisfactory measure of true + +deformation in terms of the +displacement of points within + +a deformed body where that +displacement can arise from + +either rigid body rotation +and or deformation. + +So finally, we have a tensor +epsilon ij, which is the + +strain tensor. + +And now I can finally make my +claim that, if this really is + +true deformation, that +for cubic crystals-- + +you can see the same +[INAUDIBLE] + +window coming again-- + +since second ranked tensors have +to be symmetric for cubic + +crystals, the form of +strain for a cubic + +crystal can only be this. + +It has to be diagonal +if the tensor is to + +conform to cubic symmetry. + +And you say, ah, ah, you tried +to pull that on us with + +stress, too. + +And I can squish a crystal +anyway I want. + +But you can only develop +a strain if + +you deform a crystal. + +And the symmetry of the crystal +is going to determine + +how the crystal deforms. + +So therefore, a cubic crystal +should be able to deform only + +in a way that stays invariant +to the transformations of a + +cubic symmetry, right? + +So cubic crystals can only +deform isotropically. + +So if I wanted to design springs +for an automobile so + +that elastic energy could be +stored most efficiently in a + +solid, I would want to make +these automobile springs out + +of a triclinic metal. + +Because then the tensor could be +one of general deformation. + +OK, well, this, obviously, is +a swindle like my assertion + +that stress could only be an +isotropic compressional stress + +for a cubic crystal. + +But the argument is a little +more convoluted. + +And strain, indeed, is +also a field tensor. + +Because, even though I can only +create the deformation by + +application of a stress or +perhaps an electric field or + +something of that sort in that +the link between the + +deformation and what I do to +the crystal is coupled by a + +property of the crystal, which +has to conform to the symmetry + +of the crystal, nevertheless, +given a tensor that describes + +deformation, I can always, +independent of the symmetry of + +the crystal, devise a particular +set of stresses + +that would produce any state +of strain I want. + +I would have to design, though, +a particular state of + +stress to produce a desired +state of strain. + +And that coupling has +to conform to the + +symmetry of the crystal. + +But there's no reason why strain +itself has to conform + +to the symmetry of +the crystal. + +I can create any state of strain +I like by choosing the + +appropriate stress. + +OK, so that is a swindle. + +But everything now that I can +say about the behavior of a + +second ranked tensor applies +to the strain tensor. + +I can take a strain +tensor epsilon ij. + +And I can perform the surface +epsilon ij xi xj equals 1. + +And that will be the +strain quadric. + +The strain quadric will have the +property like any quadric + +constructed from a tensor that +the value of the radius in a + +particular direction is going to +be such that the strain in + +that direction is equal to 1 +over the radius squared. + +So what does that mean? + +Well, we have to look at what +the strain tensor is relating. + +The direction, remember now +that the definition of the + +strain tensor is that U +sub i equals epsilon + +ij times x sub j. + +So the quote "applied vector" +is the direction in a solid. + +And we will get, in general, a +displacement, U, which is not + +parallel to the direction +that we're considering. + +And the epsilon in a particular +direction is going + +to be equal to the part of +U that's parallel to the + +direction of interest divided by +distance in that direction. + +And what this is going to give +us is the tensile component of + +deformation in the direction +that we're examining. + +Now, the radius normal property +works in this case. + +And what the radius normal +property says, if you look at + +a certain direction in the solid +and then look at the + +normal to the surface at that +particular point, this will be + +the direction of +what happened. + +So I've not drawn +this correctly. + +This should be the direction +of U. And this + +is the radio vector. + +So the normal to the surface +gives us the direction of the + +displacement that's +going to occur. + +And the reason I can say that +is by definition that that + +property holds only for +a symmetric tensor. + +And by definition, we have +defined the strained tensor + +such that it is symmetric. + +So the radius normal +property holds. + +If we want to change from one +coordinate system to another, + +we do that by the all for +transformation of a second + +ranked tensor that, if we change +coordinate system, the + +elements of strain change to +new values epsilon ij prime + +that are given by cil cjm times +epsilon lm, the same law + +for transformation of a second +ranked tensor that we have + +seen earlier. + +Finally, we can, because there +is a quadric, we can change + +that by finding eigenvectors +and eigenvalues, take a + +general form of the tensor +epsilon 1, 1, epsilon 1, 2, + +epsilon 1, 3, and so on, and +by solving the eigenvalue + +problem, convert this to a value +epsilon 1, 1 prime 0, 0, + +0, epsilon 2, 2 prime 0, 0, 0, +epsilon 3, 3 prime to find out + +what the extreme values of +tensile deformation are and + +the orientations within the +original description of the + +body in which these extreme +values occur. + +OK, I'm just about +out of time. + +I'll save until next time +another neat feature of the + +strain tensor. + +And that is contained within +these elements is information + +on the volume change that +the body undergoes. + +And this is something +called the dilation. + +And we'll see that this is +related in a very simple way + +to the elements of the +strain tensor. + +OK, we've spent a lot of time +developing the formalism of + +stress and strain. + +And next thing we'll do is to +move on to some interesting + +properties of crystals, which +are defined in terms of + +tensors of rank higher +than two. + +So we'll look at some third +ranked tensor properties. + +That will include things like +piezoelectricity, the stress + +optical effect, and things +of that sort. + +These are going to be +really anisotropic. + +Second ranked tensors were +anisotropic enough. + +But the variation of property +with direction was a + +quasi-ellipsoidal variation When +as 1 over the square of + +the radius of the quadric. + +For higher ranked tensor +properties, we will encounter + +some absolutely weird surfaces +with dimples and lumps and + +lobes, not this smooth +quasi-ellipsoidal variation, a + +property with direction, which +was the case for second ranked + +tensor properties. + +So we will get into some exotic +anisotropies very + +shortly to finish +up the semester. + +So I will probably see some +of you at the MRS + +meeting next week. + +I won't see you on Thursday for +reasons that I need not + +elaborate upon. + +So I hope you have +a happy holiday. + +Relax, suck in air, and come +back refreshed next Tuesday + +for some really wild anisotropy +of physical + +properties. \ No newline at end of file diff --git a/R2vL2wLqGYg.txt b/R2vL2wLqGYg.txt new file mode 100644 index 0000000000000000000000000000000000000000..880cf9d656fb7cd2d0a6d5c9317b67f6170dd743 --- /dev/null +++ b/R2vL2wLqGYg.txt @@ -0,0 +1,9139 @@ +align:start position:0% + +okay so this is dive in and I'll just + + align:start position:0% +okay so this is dive in and I'll just + + + align:start position:0% +okay so this is dive in and I'll just +quickly recap where we were last time so + + align:start position:0% +quickly recap where we were last time so + + + align:start position:0% +quickly recap where we were last time so +what I did last time was we are now + + align:start position:0% +what I did last time was we are now + + + align:start position:0% +what I did last time was we are now +beginning the adventure so to speak of + + align:start position:0% +beginning the adventure so to speak of + + + align:start position:0% +beginning the adventure so to speak of +looking at how one examines how one + + align:start position:0% +looking at how one examines how one + + + align:start position:0% +looking at how one examines how one +finds and then studies the properties of + + align:start position:0% +finds and then studies the properties of + + + align:start position:0% +finds and then studies the properties of +solutions to the Einstein field + + align:start position:0% +solutions to the Einstein field + + + align:start position:0% +solutions to the Einstein field +equations in other words given a + + align:start position:0% +equations in other words given a + + + align:start position:0% +equations in other words given a +particular source what is the space-time + + align:start position:0% +particular source what is the space-time + + + align:start position:0% +particular source what is the space-time +that emerges + + align:start position:0% +that emerges + + + align:start position:0% +that emerges +what is the space-time that is + + align:start position:0% +what is the space-time that is + + + align:start position:0% +what is the space-time that is +consistent with that source of gravity + + align:start position:0% +consistent with that source of gravity + + + align:start position:0% +consistent with that source of gravity +in Einstein's relativistic theory here + + align:start position:0% +in Einstein's relativistic theory here + + + align:start position:0% +in Einstein's relativistic theory here +so we began we're gonna look at this in + + align:start position:0% +so we began we're gonna look at this in + + + align:start position:0% +so we began we're gonna look at this in +a couple of different ways and the first + + align:start position:0% +a couple of different ways and the first + + + align:start position:0% +a couple of different ways and the first +one is where we're going to what we do + + align:start position:0% +one is where we're going to what we do + + + align:start position:0% +one is where we're going to what we do +linearize the Einstein equations so + + align:start position:0% +linearize the Einstein equations so + + + align:start position:0% +linearize the Einstein equations so +we're gonna imagine that space-time is a + + align:start position:0% +we're gonna imagine that space-time is a + + + align:start position:0% +we're gonna imagine that space-time is a +small deviation from the flat space-time + + align:start position:0% +small deviation from the flat space-time + + + align:start position:0% +small deviation from the flat space-time +that contains no gravity and we are + + align:start position:0% +that contains no gravity and we are + + + align:start position:0% +that contains no gravity and we are +going to expand the Einstein field + + align:start position:0% +going to expand the Einstein field + + + align:start position:0% +going to expand the Einstein field +equations discarding all terms that are + + align:start position:0% +equations discarding all terms that are + + + align:start position:0% +equations discarding all terms that are +nonlinear in the perturbation away from + + align:start position:0% +nonlinear in the perturbation away from + + + align:start position:0% +nonlinear in the perturbation away from +flat space-time so last time we did this + + align:start position:0% +flat space-time so last time we did this + + + align:start position:0% +flat space-time so last time we did this +we developed our we developed our field + + align:start position:0% +we developed our we developed our field + + + align:start position:0% +we developed our we developed our field +equations we recast them in a form + + align:start position:0% +equations we recast them in a form + + + align:start position:0% +equations we recast them in a form +that's particularly convenient for + + align:start position:0% +that's particularly convenient for + + + align:start position:0% +that's particularly convenient for +making solutions and we noted that the + + align:start position:0% +making solutions and we noted that the + + + align:start position:0% +making solutions and we noted that the +coordinate degrees of freedom can be + + align:start position:0% +coordinate degrees of freedom can be + + + align:start position:0% +coordinate degrees of freedom can be +thought of as a kind of gauge freedom + + align:start position:0% +thought of as a kind of gauge freedom + + + align:start position:0% +thought of as a kind of gauge freedom +that in some ways it's very useful for + + align:start position:0% +that in some ways it's very useful for + + + align:start position:0% +that in some ways it's very useful for +us because it allows us to write the + + align:start position:0% +us because it allows us to write the + + + align:start position:0% +us because it allows us to write the +equations in a form that is particularly + + align:start position:0% +equations in a form that is particularly + + + align:start position:0% +equations in a form that is particularly +amenable to solving but can also be a + + align:start position:0% +amenable to solving but can also be a + + + align:start position:0% +amenable to solving but can also be a +little bit dangerous because you can + + align:start position:0% +little bit dangerous because you can + + + align:start position:0% +little bit dangerous because you can +sometimes wind up with a solution whose + + align:start position:0% +sometimes wind up with a solution whose + + + align:start position:0% +sometimes wind up with a solution whose +physical character is masked by the + + align:start position:0% +physical character is masked by the + + + align:start position:0% +physical character is masked by the +nature of that gauge I went through a + + align:start position:0% +nature of that gauge I went through a + + + align:start position:0% +nature of that gauge I went through a +somewhat advanced topic for the purposes + + align:start position:0% +somewhat advanced topic for the purposes + + + align:start position:0% +somewhat advanced topic for the purposes +of 89-62 and I do not expect students to + + align:start position:0% +of 89-62 and I do not expect students to + + + align:start position:0% +of 89-62 and I do not expect students to +follow this in detail but it's good to + + align:start position:0% +follow this in detail but it's good to + + + align:start position:0% +follow this in detail but it's good to +at least survey this and understand what + + align:start position:0% +at least survey this and understand what + + + align:start position:0% +at least survey this and understand what +was going off this what I did was I + + align:start position:0% +was going off this what I did was I + + + align:start position:0% +was going off this what I did was I +decomposed the perturbation of flat + + align:start position:0% +decomposed the perturbation of flat + + + align:start position:0% +decomposed the perturbation of flat +space-time into irreducible degrees of + + align:start position:0% +space-time into irreducible degrees of + + + align:start position:0% +space-time into irreducible degrees of +freedom I sort of chose a time + + align:start position:0% +freedom I sort of chose a time + + + align:start position:0% +freedom I sort of chose a time +coordinate I then imagine the other + + align:start position:0% +coordinate I then imagine the other + + + align:start position:0% +coordinate I then imagine the other +three coordinates are spaced and I + + align:start position:0% +three coordinates are spaced and I + + + align:start position:0% +three coordinates are spaced and I +looked at how having chosen time the + + align:start position:0% +looked at how having chosen time the + + + align:start position:0% +looked at how having chosen time the +different degrees of freedom decomposed + + align:start position:0% +different degrees of freedom decomposed + + + align:start position:0% +different degrees of freedom decomposed +into scalars with respect to coordinate + + align:start position:0% +into scalars with respect to coordinate + + + align:start position:0% +into scalars with respect to coordinate +rotations vectors with respect to + + align:start position:0% +rotations vectors with respect to + + + align:start position:0% +rotations vectors with respect to +coordinate rotations and to index + + align:start position:0% +coordinate rotations and to index + + + align:start position:0% +coordinate rotations and to index +tensors of the Vexin coordinate + + align:start position:0% +tensors of the Vexin coordinate + + + align:start position:0% +tensors of the Vexin coordinate +rotations I then took those particularly + + align:start position:0% +rotations I then took those particularly + + + align:start position:0% +rotations I then took those particularly +the vectors and the tensors + + align:start position:0% +the vectors and the tensors + + + align:start position:0% +the vectors and the tensors +and I further broke them up into degrees + + align:start position:0% +and I further broke them up into degrees + + + align:start position:0% +and I further broke them up into degrees +of freedom that are either divergence + + align:start position:0% +of freedom that are either divergence + + + align:start position:0% +of freedom that are either divergence +free divergence free vector fields or + + align:start position:0% +free divergence free vector fields or + + + align:start position:0% +free divergence free vector fields or +the gradients of scalar fields okay + + align:start position:0% +the gradients of scalar fields okay + + + align:start position:0% +the gradients of scalar fields okay +and in doing this what we found was that + + align:start position:0% +and in doing this what we found was that + + + align:start position:0% +and in doing this what we found was that +the ten degrees of freedom that are + + align:start position:0% +the ten degrees of freedom that are + + + align:start position:0% +the ten degrees of freedom that are +specified actually the ten degrees of + + align:start position:0% +specified actually the ten degrees of + + + align:start position:0% +specified actually the ten degrees of +freedom that are present in the + + align:start position:0% +freedom that are present in the + + + align:start position:0% +freedom that are present in the +perturbation the space-time can be + + align:start position:0% +perturbation the space-time can be + + + align:start position:0% +perturbation the space-time can be +broken down into six functions that are + + align:start position:0% +broken down into six functions that are + + + align:start position:0% +broken down into six functions that are +gauge invariants plus 4 gauge degrees of + + align:start position:0% +gauge invariants plus 4 gauge degrees of + + + align:start position:0% +gauge invariants plus 4 gauge degrees of +freedom applying a similar decomposition + + align:start position:0% +freedom applying a similar decomposition + + + align:start position:0% +freedom applying a similar decomposition +to the source we found that those six + + align:start position:0% +to the source we found that those six + + + align:start position:0% +to the source we found that those six +gauge invariant degrees of freedom are + + align:start position:0% +gauge invariant degrees of freedom are + + + align:start position:0% +gauge invariant degrees of freedom are +governed by four poisson type equations + + align:start position:0% +governed by four poisson type equations + + + align:start position:0% +governed by four poisson type equations +and I will refer you to the previous + + align:start position:0% +and I will refer you to the previous + + + align:start position:0% +and I will refer you to the previous +lecture for exact definitions of these + + align:start position:0% +lecture for exact definitions of these + + + align:start position:0% +lecture for exact definitions of these +things but there is a scalar field Phi + + align:start position:0% +things but there is a scalar field Phi + + + align:start position:0% +things but there is a scalar field Phi +that is related to the mean density of + + align:start position:0% +that is related to the mean density of + + + align:start position:0% +that is related to the mean density of +energy mean density of energy in your + + align:start position:0% +energy mean density of energy in your + + + align:start position:0% +energy mean density of energy in your +space-time and pressures in your space + + align:start position:0% +space-time and pressures in your space + + + align:start position:0% +space-time and pressures in your space +I'm sort of an isotropic stresses this + + align:start position:0% +I'm sort of an isotropic stresses this + + + align:start position:0% +I'm sort of an isotropic stresses this +DTS is an additional degree of freedom + + align:start position:0% +DTS is an additional degree of freedom + + + align:start position:0% +DTS is an additional degree of freedom +that is defined in that previous lecture + + align:start position:0% +that is defined in that previous lecture + + + align:start position:0% +that is defined in that previous lecture +you find that a placin equation for a + + align:start position:0% +you find that a placin equation for a + + + align:start position:0% +you find that a placin equation for a +scalar field I called theta is really + + align:start position:0% +scalar field I called theta is really + + + align:start position:0% +scalar field I called theta is really +directly related to the energy density + + align:start position:0% +directly related to the energy density + + + align:start position:0% +directly related to the energy density +there is there are two degrees of + + align:start position:0% +there is there are two degrees of + + + align:start position:0% +there is there are two degrees of +freedom associated with sort of off + + align:start position:0% +freedom associated with sort of off + + + align:start position:0% +freedom associated with sort of off +diagonal terms in the metric the + + align:start position:0% +diagonal terms in the metric the + + + align:start position:0% +diagonal terms in the metric the +time/space terms in the metric and + + align:start position:0% +time/space terms in the metric and + + + align:start position:0% +time/space terms in the metric and +they're related to the momentum flow + + align:start position:0% +they're related to the momentum flow + + + align:start position:0% +they're related to the momentum flow +these are only two degrees of freedom + + align:start position:0% +these are only two degrees of freedom + + + align:start position:0% +these are only two degrees of freedom +because this sigh is a divergence free + + align:start position:0% +because this sigh is a divergence free + + + align:start position:0% +because this sigh is a divergence free +field and finally what we found is if + + align:start position:0% +field and finally what we found is if + + + align:start position:0% +field and finally what we found is if +you take the spatial piece of the + + align:start position:0% +you take the spatial piece of the + + + align:start position:0% +you take the spatial piece of the +space-time metric you project out the + + align:start position:0% +space-time metric you project out the + + + align:start position:0% +space-time metric you project out the +bits that are transverse in other words + + align:start position:0% +bits that are transverse in other words + + + align:start position:0% +bits that are transverse in other words +it's divergence free we will come to a + + align:start position:0% +it's divergence free we will come to a + + + align:start position:0% +it's divergence free we will come to a +more physical meaning of this a little + + align:start position:0% +more physical meaning of this a little + + + align:start position:0% +more physical meaning of this a little +bit later in today's lecture and require + + align:start position:0% +bit later in today's lecture and require + + + align:start position:0% +bit later in today's lecture and require +that this be traceless then those + + align:start position:0% +that this be traceless then those + + + align:start position:0% +that this be traceless then those +components of the spatial space-time + + align:start position:0% +components of the spatial space-time + + + align:start position:0% +components of the spatial space-time +perturbation are already gauge + + align:start position:0% +perturbation are already gauge + + + align:start position:0% +perturbation are already gauge +invariants and they're related to sort + + align:start position:0% +invariants and they're related to sort + + + align:start position:0% +invariants and they're related to sort +of anisotropic stresses in our source + + align:start position:0% +of anisotropic stresses in our source + + + align:start position:0% +of anisotropic stresses in our source +they are governed by a wave equation and + + align:start position:0% +they are governed by a wave equation and + + + align:start position:0% +they are governed by a wave equation and +as such these represent a radiative + + align:start position:0% +as such these represent a radiative + + + align:start position:0% +as such these represent a radiative +degree of freedom + + align:start position:0% +degree of freedom + + + align:start position:0% +degree of freedom +cuz this is feeling because this is tres + + align:start position:0% +cuz this is feeling because this is tres + + + align:start position:0% +cuz this is feeling because this is tres +free and divergence trait this naively + + align:start position:0% +free and divergence trait this naively + + + align:start position:0% +free and divergence trait this naively +you would think that this that this has + + align:start position:0% +you would think that this that this has + + + align:start position:0% +you would think that this that this has +six numbers in it it's a symmetric 3x3 + + align:start position:0% +six numbers in it it's a symmetric 3x3 + + + align:start position:0% +six numbers in it it's a symmetric 3x3 +matrix is how we would represent it but + + align:start position:0% +matrix is how we would represent it but + + + align:start position:0% +matrix is how we would represent it but +because it is trace free and because of + + align:start position:0% +because it is trace free and because of + + + align:start position:0% +because it is trace free and because of +this divergence list there are four + + align:start position:0% +this divergence list there are four + + + align:start position:0% +this divergence list there are four +constraints and so those six independent + + align:start position:0% +constraints and so those six independent + + + align:start position:0% +constraints and so those six independent +numbers are reduced to two and as we'll + + align:start position:0% +numbers are reduced to two and as we'll + + + align:start position:0% +numbers are reduced to two and as we'll +see in this lecture + + align:start position:0% +see in this lecture + + + align:start position:0% +see in this lecture +those two degrees of freedom correspond + + align:start position:0% +those two degrees of freedom correspond + + + align:start position:0% +those two degrees of freedom correspond +to the polarizations of gravitational + + align:start position:0% +to the polarizations of gravitational + + + align:start position:0% +to the polarizations of gravitational +waves today's lecture is all about + + align:start position:0% +waves today's lecture is all about + + + align:start position:0% +waves today's lecture is all about +understanding these guys okay given our + + align:start position:0% +understanding these guys okay given our + + + align:start position:0% +understanding these guys okay given our +kind of a funny schedule it we're on + + align:start position:0% +kind of a funny schedule it we're on + + + align:start position:0% +kind of a funny schedule it we're on +today I got up early have not had time + + align:start position:0% +today I got up early have not had time + + + align:start position:0% +today I got up early have not had time +to take a shower so I am wearing my LIGO + + align:start position:0% +to take a shower so I am wearing my LIGO + + + align:start position:0% +to take a shower so I am wearing my LIGO +hat and what are we doing today is the + + align:start position:0% +hat and what are we doing today is the + + + align:start position:0% +hat and what are we doing today is the +foundations of how one calculates this + + align:start position:0% +foundations of how one calculates this + + + align:start position:0% +foundations of how one calculates this +and why one builds an observatory like + + align:start position:0% +and why one builds an observatory like + + + align:start position:0% +and why one builds an observatory like +LIGO to measure these things all right + + align:start position:0% +LIGO to measure these things all right + + + align:start position:0% +LIGO to measure these things all right +so let me just write that out so our + + align:start position:0% +so let me just write that out so our + + + align:start position:0% +so let me just write that out so our +goal for today I shouldn't say our goal + + align:start position:0% +goal for today I shouldn't say our goal + + + align:start position:0% +goal for today I shouldn't say our goal +for this lecture because this is the + + align:start position:0% +for this lecture because this is the + + + align:start position:0% +for this lecture because this is the +first of three lectures I'm going to + + align:start position:0% +first of three lectures I'm going to + + + align:start position:0% +first of three lectures I'm going to +record today our goal is to understand + + align:start position:0% + + + + align:start position:0% + +hij tt in terms of quantities that we + + align:start position:0% +hij tt in terms of quantities that we + + + align:start position:0% +hij tt in terms of quantities that we +can observe and also to understand how + + align:start position:0% +can observe and also to understand how + + + align:start position:0% +can observe and also to understand how +to compute this field this h IJ t t + + align:start position:0% + + + + align:start position:0% + +given a source so let's begin by just + + align:start position:0% +given a source so let's begin by just + + + align:start position:0% +given a source so let's begin by just +assuming let's begin by focusing on how + + align:start position:0% +assuming let's begin by focusing on how + + + align:start position:0% +assuming let's begin by focusing on how +we can understand what h IJ t t actually + + align:start position:0% +we can understand what h IJ t t actually + + + align:start position:0% +we can understand what h IJ t t actually +means how we can go and measure this so + + align:start position:0% +means how we can go and measure this so + + + align:start position:0% +means how we can go and measure this so +what I'm gonna do is just we'll start + + align:start position:0% +what I'm gonna do is just we'll start + + + align:start position:0% +what I'm gonna do is just we'll start +out by enlist as hand ourselves an H I J + + align:start position:0% +out by enlist as hand ourselves an H I J + + + align:start position:0% +out by enlist as hand ourselves an H I J +TT and study its properties + + align:start position:0% + + + + align:start position:0% + +so what I'm going to do is begin with a + + align:start position:0% +so what I'm going to do is begin with a + + + align:start position:0% +so what I'm going to do is begin with a +spacetime perturbation it has everything + + align:start position:0% +spacetime perturbation it has everything + + + align:start position:0% +spacetime perturbation it has everything +except hij tt equals zero so this is + + align:start position:0% +except hij tt equals zero so this is + + + align:start position:0% +except hij tt equals zero so this is +something that has Phi equals zero theta + + align:start position:0% +something that has Phi equals zero theta + + + align:start position:0% +something that has Phi equals zero theta +equals zero + + align:start position:0% + + + + align:start position:0% + +sigh equal to zero + + align:start position:0% +sigh equal to zero + + + align:start position:0% +sigh equal to zero +I am going to pick H I J tt we have a + + align:start position:0% +I am going to pick H I J tt we have a + + + align:start position:0% +I am going to pick H I J tt we have a +form such that it only depends it's a + + align:start position:0% +form such that it only depends it's a + + + align:start position:0% +form such that it only depends it's a +function that depends only on the + + align:start position:0% +function that depends only on the + + + align:start position:0% +function that depends only on the +combination T minus C so this represents + + align:start position:0% +combination T minus C so this represents + + + align:start position:0% +combination T minus C so this represents +something propagating as we see it + + align:start position:0% +something propagating as we see it + + + align:start position:0% +something propagating as we see it +actually describes radiation propagating + + align:start position:0% +actually describes radiation propagating + + + align:start position:0% +actually describes radiation propagating +in the Z direction okay so this assumed + + align:start position:0% +in the Z direction okay so this assumed + + + align:start position:0% +in the Z direction okay so this assumed +form can be represented by following + + align:start position:0% +form can be represented by following + + + align:start position:0% +form can be represented by following +matrix + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you take a look at this I'm gonna + + align:start position:0% +so if you take a look at this I'm gonna + + + align:start position:0% +so if you take a look at this I'm gonna +justify a few details of this later + + align:start position:0% +justify a few details of this later + + + align:start position:0% +justify a few details of this later +there's a few constraints so it looks + + align:start position:0% +there's a few constraints so it looks + + + align:start position:0% +there's a few constraints so it looks +like I have four numbers here because my + + align:start position:0% +like I have four numbers here because my + + + align:start position:0% +like I have four numbers here because my +space-time metric is always symmetric + + align:start position:0% +space-time metric is always symmetric + + + align:start position:0% +space-time metric is always symmetric +under just a symmetry its symmetric + + align:start position:0% +under just a symmetry its symmetric + + + align:start position:0% +under just a symmetry its symmetric +under exchange of indices H X Y is the + + align:start position:0% +under exchange of indices H X Y is the + + + align:start position:0% +under exchange of indices H X Y is the +same thing as H Y X so these two things + + align:start position:0% +same thing as H Y X so these two things + + + align:start position:0% +same thing as H Y X so these two things +are the same and from the requirement + + align:start position:0% +are the same and from the requirement + + + align:start position:0% +are the same and from the requirement +that this construction betray straight + + align:start position:0% +that this construction betray straight + + + align:start position:0% +that this construction betray straight +so from the way I've written this here + + align:start position:0% +so from the way I've written this here + + + align:start position:0% +so from the way I've written this here +that tells me that H X X plus h YY must + + align:start position:0% +that tells me that H X X plus h YY must + + + align:start position:0% +that tells me that H X X plus h YY must +equal zero so these two quantities on + + align:start position:0% +equal zero so these two quantities on + + + align:start position:0% +equal zero so these two quantities on +the diagonal are not independent they + + align:start position:0% +the diagonal are not independent they + + + align:start position:0% +the diagonal are not independent they +must be of opposite sign so there are my + + align:start position:0% +must be of opposite sign so there are my + + + align:start position:0% +must be of opposite sign so there are my +two degrees of freedom + + align:start position:0% +two degrees of freedom + + + align:start position:0% +two degrees of freedom +why have I set the Z part equal to zero + + align:start position:0% +why have I set the Z part equal to zero + + + align:start position:0% +why have I set the Z part equal to zero +we'll look at that in a little bit more + + align:start position:0% +we'll look at that in a little bit more + + + align:start position:0% +we'll look at that in a little bit more +detail a little later in the lecture but + + align:start position:0% +detail a little later in the lecture but + + + align:start position:0% +detail a little later in the lecture but +essentially it comes from the fact that + + align:start position:0% +essentially it comes from the fact that + + + align:start position:0% +essentially it comes from the fact that +I'm making it propagate in the Z + + align:start position:0% +I'm making it propagate in the Z + + + align:start position:0% +I'm making it propagate in the Z +direction what we're going to see is + + align:start position:0% +direction what we're going to see is + + + align:start position:0% +direction what we're going to see is +that if whatever direction the wave is + + align:start position:0% +that if whatever direction the wave is + + + align:start position:0% +that if whatever direction the wave is +propagating in my field has to be + + align:start position:0% +propagating in my field has to be + + + align:start position:0% +propagating in my field has to be +orthogonal to it and we'll prove that a + + align:start position:0% +orthogonal to it and we'll prove that a + + + align:start position:0% +orthogonal to it and we'll prove that a +little bit more carefully later so for + + align:start position:0% +little bit more carefully later so for + + + align:start position:0% +little bit more carefully later so for +now let's just take this as handed to us + + align:start position:0% +now let's just take this as handed to us + + + align:start position:0% +now let's just take this as handed to us +okay we can see this is that leaves + + align:start position:0% +okay we can see this is that leaves + + + align:start position:0% +okay we can see this is that leaves +consistent with the properties I've + + align:start position:0% +consistent with the properties I've + + + align:start position:0% +consistent with the properties I've +written down here from the fact that it + + align:start position:0% +written down here from the fact that it + + + align:start position:0% +written down here from the fact that it +depends on T - Z it's not hard to show + + align:start position:0% +depends on T - Z it's not hard to show + + + align:start position:0% +depends on T - Z it's not hard to show +that this thing will satisfy the wave + + align:start position:0% +that this thing will satisfy the wave + + + align:start position:0% +that this thing will satisfy the wave +equation + + align:start position:0% + + + + align:start position:0% + +so we have a good source for exploration + + align:start position:0% +so we have a good source for exploration + + + align:start position:0% +so we have a good source for exploration +in front of us you mean a good space + + align:start position:0% +in front of us you mean a good space + + + align:start position:0% +in front of us you mean a good space +time for us to explore the properties of + + align:start position:0% +time for us to explore the properties of + + + align:start position:0% +time for us to explore the properties of +so let's begin by saying great one of + + align:start position:0% +so let's begin by saying great one of + + + align:start position:0% +so let's begin by saying great one of +the most important things we've learned + + align:start position:0% +the most important things we've learned + + + align:start position:0% +the most important things we've learned +how to do is given a space time I can + + align:start position:0% +how to do is given a space time I can + + + align:start position:0% +how to do is given a space time I can +compute how a freely falling body moves + + align:start position:0% +compute how a freely falling body moves + + + align:start position:0% +compute how a freely falling body moves +in that space-time so let's consider + + align:start position:0% +in that space-time so let's consider + + + align:start position:0% +in that space-time so let's consider +what happens if I have freely falling + + align:start position:0% +what happens if I have freely falling + + + align:start position:0% +what happens if I have freely falling +bodies in a space-time in a spacetime + + align:start position:0% +bodies in a space-time in a spacetime + + + align:start position:0% +bodies in a space-time in a spacetime +such that this you know in a space-time + + align:start position:0% +such that this you know in a space-time + + + align:start position:0% +such that this you know in a space-time +that is this so I'm not saying it's very + + align:start position:0% +that is this so I'm not saying it's very + + + align:start position:0% +that is this so I'm not saying it's very +slowly okay so here's what we want to do + + align:start position:0% +slowly okay so here's what we want to do + + + align:start position:0% +slowly okay so here's what we want to do +we're gonna consider freely falling + + align:start position:0% +we're gonna consider freely falling + + + align:start position:0% +we're gonna consider freely falling +bodies in a space-time that involves + + align:start position:0% +bodies in a space-time that involves + + + align:start position:0% +bodies in a space-time that involves +this HM you know the way I'm going to do + + align:start position:0% +this HM you know the way I'm going to do + + + align:start position:0% +this HM you know the way I'm going to do +this my first pass is sort of say okay I + + align:start position:0% +this my first pass is sort of say okay I + + + align:start position:0% +this my first pass is sort of say okay I +know all about the motion of freely + + align:start position:0% +know all about the motion of freely + + + align:start position:0% +know all about the motion of freely +falling bodies in space-time they are + + align:start position:0% +falling bodies in space-time they are + + + align:start position:0% +falling bodies in space-time they are +geodesics judy's X describes such bodies + + align:start position:0% +geodesics judy's X describes such bodies + + + align:start position:0% +geodesics judy's X describes such bodies +so let's go ahead and look at the judy's + + align:start position:0% +so let's go ahead and look at the judy's + + + align:start position:0% +so let's go ahead and look at the judy's +equation for this for this set up now I + + align:start position:0% +equation for this for this set up now I + + + align:start position:0% +equation for this for this set up now I +wanted to split let's give ourselves a + + align:start position:0% +wanted to split let's give ourselves a + + + align:start position:0% +wanted to split let's give ourselves a +couple of conditions to try to + + align:start position:0% +couple of conditions to try to + + + align:start position:0% +couple of conditions to try to +understand this let's imagine that these + + align:start position:0% +understand this let's imagine that these + + + align:start position:0% +understand this let's imagine that these +are we're initially in a space-time that + + align:start position:0% +are we're initially in a space-time that + + + align:start position:0% +are we're initially in a space-time that +is just flat space-time + + align:start position:0% + + + + align:start position:0% + +so we're gonna imagine that h mu nu is + + align:start position:0% +so we're gonna imagine that h mu nu is + + + align:start position:0% +so we're gonna imagine that h mu nu is +zero initially and perhaps it then you + + align:start position:0% +zero initially and perhaps it then you + + + align:start position:0% +zero initially and perhaps it then you +know we're sort of imagining a spacetime + + align:start position:0% +know we're sort of imagining a spacetime + + + align:start position:0% +know we're sort of imagining a spacetime +in which there's just you're falling + + align:start position:0% +in which there's just you're falling + + + align:start position:0% +in which there's just you're falling +freely an empty space absolutely nothing + + align:start position:0% +freely an empty space absolutely nothing + + + align:start position:0% +freely an empty space absolutely nothing +going on here and this atria new field + + align:start position:0% +going on here and this atria new field + + + align:start position:0% +going on here and this atria new field +passes over you okay a wave packet + + align:start position:0% +passes over you okay a wave packet + + + align:start position:0% +passes over you okay a wave packet +passes over your freely falling + + align:start position:0% +passes over your freely falling + + + align:start position:0% +passes over your freely falling +particles so H mu nu naught equals zero + + align:start position:0% +particles so H mu nu naught equals zero + + + align:start position:0% +particles so H mu nu naught equals zero +comes along and passes over your + + align:start position:0% +comes along and passes over your + + + align:start position:0% +comes along and passes over your +particles I'm going to imagine that + + align:start position:0% +particles I'm going to imagine that + + + align:start position:0% +particles I'm going to imagine that +these bodies are initially at rest okay + + align:start position:0% +these bodies are initially at rest okay + + + align:start position:0% +these bodies are initially at rest okay +so when I'm in this route this regime + + align:start position:0% +so when I'm in this route this regime + + + align:start position:0% +so when I'm in this route this regime +where H V nu is equal to zero these guys + + align:start position:0% +where H V nu is equal to zero these guys + + + align:start position:0% +where H V nu is equal to zero these guys +are just sitting stationary with respect + + align:start position:0% +are just sitting stationary with respect + + + align:start position:0% +are just sitting stationary with respect +to whoever is making these measurements + + align:start position:0% + + + + align:start position:0% + +okay so we're gonna say great I've got + + align:start position:0% +okay so we're gonna say great I've got + + + align:start position:0% +okay so we're gonna say great I've got +these bodies sitting at rest and what is + + align:start position:0% +these bodies sitting at rest and what is + + + align:start position:0% +these bodies sitting at rest and what is +initially empty space-time wave passes + + align:start position:0% +initially empty space-time wave passes + + + align:start position:0% +initially empty space-time wave passes +along what happens to these bodies so if + + align:start position:0% +along what happens to these bodies so if + + + align:start position:0% +along what happens to these bodies so if +these guys are at rest that I know that + + align:start position:0% +these guys are at rest that I know that + + + align:start position:0% +these guys are at rest that I know that +at initial times so let's just say that + + align:start position:0% +at initial times so let's just say that + + + align:start position:0% +at initial times so let's just say that +this comes along and it becomes H P nu + + align:start position:0% +this comes along and it becomes H P nu + + + align:start position:0% +this comes along and it becomes H P nu +not equal to zero at some time what is + + align:start position:0% +not equal to zero at some time what is + + + align:start position:0% +not equal to zero at some time what is +to find that is the origin of time so T + + align:start position:0% +to find that is the origin of time so T + + + align:start position:0% +to find that is the origin of time so T +equals zero is when the non-zero wave + + align:start position:0% +equals zero is when the non-zero wave + + + align:start position:0% +equals zero is when the non-zero wave +comes along so my space time is just + + align:start position:0% +comes along so my space time is just + + + align:start position:0% +comes along so my space time is just +eight mu nu for all earlier times my + + align:start position:0% +eight mu nu for all earlier times my + + + align:start position:0% +eight mu nu for all earlier times my +particles are sitting here at rest at + + align:start position:0% +particles are sitting here at rest at + + + align:start position:0% +particles are sitting here at rest at +all earlier times then H mu nu comes + + align:start position:0% +all earlier times then H mu nu comes + + + align:start position:0% +all earlier times then H mu nu comes +along so what we want to do then is look + + align:start position:0% +along so what we want to do then is look + + + align:start position:0% +along so what we want to do then is look +at how does this guy behave at T equals + + align:start position:0% +at how does this guy behave at T equals + + + align:start position:0% +at how does this guy behave at T equals +zero + + align:start position:0% + + + + align:start position:0% + +okay now initially the only component + + align:start position:0% +okay now initially the only component + + + align:start position:0% +okay now initially the only component +that will get picked out of this is the + + align:start position:0% +that will get picked out of this is the + + + align:start position:0% +that will get picked out of this is the +zero zero complement and working to + + align:start position:0% +zero zero complement and working to + + + align:start position:0% +zero zero complement and working to +linear order I can write this okay right + + align:start position:0% +linear order I can write this okay right + + + align:start position:0% +linear order I can write this okay right +one more step in here let's say that + + align:start position:0% +one more step in here let's say that + + + align:start position:0% +one more step in here let's say that +this I'm going to write as zero go back + + align:start position:0% +this I'm going to write as zero go back + + + align:start position:0% +this I'm going to write as zero go back +to your earlier lecture when we define + + align:start position:0% +to your earlier lecture when we define + + + align:start position:0% +to your earlier lecture when we define +the Christoffel symbol to look up the + + align:start position:0% +the Christoffel symbol to look up the + + + align:start position:0% +the Christoffel symbol to look up the +definition of this guy okay so these are + + align:start position:0% +definition of this guy okay so these are + + + align:start position:0% +definition of this guy okay so these are +all the only components of the + + align:start position:0% +all the only components of the + + + align:start position:0% +all the only components of the +space-time that enter into this + + align:start position:0% +space-time that enter into this + + + align:start position:0% +space-time that enter into this +Christoffel symbol every single one + + align:start position:0% +Christoffel symbol every single one + + + align:start position:0% +Christoffel symbol every single one +let's go back and take a look at the + + align:start position:0% +let's go back and take a look at the + + + align:start position:0% +let's go back and take a look at the +space-time that we're looking down here + + align:start position:0% +space-time that we're looking down here + + + align:start position:0% +space-time that we're looking down here +notice this involves beta 0 0 beta and 0 + + align:start position:0% +notice this involves beta 0 0 beta and 0 + + + align:start position:0% +notice this involves beta 0 0 beta and 0 +0 that is the space-time parts all of + + align:start position:0% +0 that is the space-time parts all of + + + align:start position:0% +0 that is the space-time parts all of +which are 0 the other space-time parts + + align:start position:0% +which are 0 the other space-time parts + + + align:start position:0% +which are 0 the other space-time parts +all of which are 0 and the time time + + align:start position:0% +all of which are 0 and the time time + + + align:start position:0% +all of which are 0 and the time time +part which is 0 so the initial + + align:start position:0% +part which is 0 so the initial + + + align:start position:0% +part which is 0 so the initial +acceleration is 0 that means do u alpha + + align:start position:0% +acceleration is 0 that means do u alpha + + + align:start position:0% +acceleration is 0 that means do u alpha +D tau is equal to 0 which means that my + + align:start position:0% +D tau is equal to 0 which means that my + + + align:start position:0% +D tau is equal to 0 which means that my +particle begins on a judy's ik and it + + align:start position:0% +particle begins on a judy's ik and it + + + align:start position:0% +particle begins on a judy's ik and it +stays on the judy's ik in these + + align:start position:0% +stays on the judy's ik in these + + + align:start position:0% +stays on the judy's ik in these +coordinates it does not move at all + + align:start position:0% + + + + align:start position:0% + +this seems to suggest that gravitation + + align:start position:0% +this seems to suggest that gravitation + + + align:start position:0% +this seems to suggest that gravitation +waves have no effect I have a small body + + align:start position:0% +waves have no effect I have a small body + + + align:start position:0% +waves have no effect I have a small body +here gravitational waves come along + + align:start position:0% +here gravitational waves come along + + + align:start position:0% +here gravitational waves come along +it's unaccelerated so what's this for + + align:start position:0% + + + + align:start position:0% + +well if you think about this for a + + align:start position:0% +well if you think about this for a + + + align:start position:0% +well if you think about this for a +second what you should convince yourself + + align:start position:0% +second what you should convince yourself + + + align:start position:0% +second what you should convince yourself +is that the calculation I just did it's + + align:start position:0% +is that the calculation I just did it's + + + align:start position:0% +is that the calculation I just did it's +probably the first one you would think + + align:start position:0% +probably the first one you would think + + + align:start position:0% +probably the first one you would think +of doing when you're trying to ascertain + + align:start position:0% +of doing when you're trying to ascertain + + + align:start position:0% +of doing when you're trying to ascertain +how does a body move in a particular + + align:start position:0% +how does a body move in a particular + + + align:start position:0% +how does a body move in a particular +space-time but in some ways it was kind + + align:start position:0% +space-time but in some ways it was kind + + + align:start position:0% +space-time but in some ways it was kind +of a dumb calculation to do so let's + + align:start position:0% +of a dumb calculation to do so let's + + + align:start position:0% +of a dumb calculation to do so let's +bear in mind what this is doing is tell + + align:start position:0% +bear in mind what this is doing is tell + + + align:start position:0% +bear in mind what this is doing is tell +me the judaising equation describes + + align:start position:0% +me the judaising equation describes + + + align:start position:0% +me the judaising equation describes +motion with respect to some given + + align:start position:0% +motion with respect to some given + + + align:start position:0% +motion with respect to some given +coordinate system satisfying this + + align:start position:0% +coordinate system satisfying this + + + align:start position:0% +coordinate system satisfying this +equation is just saying yep + + align:start position:0% +equation is just saying yep + + + align:start position:0% +equation is just saying yep +you're falling at Judy's ik and guess + + align:start position:0% +you're falling at Judy's ik and guess + + + align:start position:0% +you're falling at Judy's ik and guess +what these are this the this radiation + + align:start position:0% +what these are this the this radiation + + + align:start position:0% +what these are this the this radiation +is a form of gravity even if the body + + align:start position:0% +is a form of gravity even if the body + + + align:start position:0% +is a form of gravity even if the body +responds to it it is still going to + + align:start position:0% +responds to it it is still going to + + + align:start position:0% +responds to it it is still going to +follow a judy's it is going to be in + + align:start position:0% +follow a judy's it is going to be in + + + align:start position:0% +follow a judy's it is going to be in +freefall the gravitational field may be + + align:start position:0% +freefall the gravitational field may be + + + align:start position:0% +freefall the gravitational field may be +a little bit different from the ones + + align:start position:0% +a little bit different from the ones + + + align:start position:0% +a little bit different from the ones +that you're more used to from your + + align:start position:0% +that you're more used to from your + + + align:start position:0% +that you're more used to from your +previous experiences with gravity but it + + align:start position:0% +previous experiences with gravity but it + + + align:start position:0% +previous experiences with gravity but it +is still just following the free fall + + align:start position:0% +is still just following the free fall + + + align:start position:0% +is still just following the free fall +trajectory that gravity demands + + align:start position:0% + + + + align:start position:0% + +so freefall in these coordinates means + + align:start position:0% +so freefall in these coordinates means + + + align:start position:0% +so freefall in these coordinates means +the body is remaining fixed in these + + align:start position:0% +the body is remaining fixed in these + + + align:start position:0% +the body is remaining fixed in these +coordinates okay this is one of the most + + align:start position:0% +coordinates okay this is one of the most + + + align:start position:0% +coordinates okay this is one of the most +important lessons in general relativity + + align:start position:0% +important lessons in general relativity + + + align:start position:0% +important lessons in general relativity +when you ask the statements that depends + + align:start position:0% +when you ask the statements that depends + + + align:start position:0% +when you ask the statements that depends +on the coordinate system you've written + + align:start position:0% +on the coordinate system you've written + + + align:start position:0% +on the coordinate system you've written +down you have to understand your + + align:start position:0% +down you have to understand your + + + align:start position:0% +down you have to understand your +coordinates and I would submit we don't + + align:start position:0% +coordinates and I would submit we don't + + + align:start position:0% +coordinates and I would submit we don't +really understand the coordinates that + + align:start position:0% +really understand the coordinates that + + + align:start position:0% +really understand the coordinates that +we wrote down here with this these + + align:start position:0% +we wrote down here with this these + + + align:start position:0% +we wrote down here with this these +coordinates essentially follow the body + + align:start position:0% +coordinates essentially follow the body + + + align:start position:0% +coordinates essentially follow the body +even if the body is moving they + + align:start position:0% +even if the body is moving they + + + align:start position:0% +even if the body is moving they +essentially wiggle right along with the + + align:start position:0% +essentially wiggle right along with the + + + align:start position:0% +essentially wiggle right along with the +body itself so if you want to understand + + align:start position:0% +body itself so if you want to understand + + + align:start position:0% +body itself so if you want to understand +what the impact of gravitational waves + + align:start position:0% +what the impact of gravitational waves + + + align:start position:0% +what the impact of gravitational waves +is on things you have to try to + + align:start position:0% +is on things you have to try to + + + align:start position:0% +is on things you have to try to +formulate what you're able to measure + + align:start position:0% +formulate what you're able to measure + + + align:start position:0% +formulate what you're able to measure +using coordinate independent language as + + align:start position:0% +using coordinate independent language as + + + align:start position:0% +using coordinate independent language as +much as possible at the very least you + + align:start position:0% +much as possible at the very least you + + + align:start position:0% +much as possible at the very least you +need to understand your coordinate + + align:start position:0% +need to understand your coordinate + + + align:start position:0% +need to understand your coordinate +system a lot better than I did in + + align:start position:0% +system a lot better than I did in + + + align:start position:0% +system a lot better than I did in +setting up this calculation over here + + align:start position:0% + + + + align:start position:0% + +so let's reframe the way we do this + + align:start position:0% +so let's reframe the way we do this + + + align:start position:0% +so let's reframe the way we do this +analysis let's imagine so what what one + + align:start position:0% +analysis let's imagine so what what one + + + align:start position:0% +analysis let's imagine so what what one +of the things that we learned in + + align:start position:0% +of the things that we learned in + + + align:start position:0% +of the things that we learned in +thinking about how gravity works in + + align:start position:0% +thinking about how gravity works in + + + align:start position:0% +thinking about how gravity works in +general relativity is I can always if + + align:start position:0% +general relativity is I can always if + + + align:start position:0% +general relativity is I can always if +I'm just focusing on a single body a + + align:start position:0% +I'm just focusing on a single body a + + + align:start position:0% +I'm just focusing on a single body a +single point mass I can always go into + + align:start position:0% +single point mass I can always go into + + + align:start position:0% +single point mass I can always go into +freely falling coordinates and + + align:start position:0% +freely falling coordinates and + + + align:start position:0% +freely falling coordinates and +space-time is essentially the space-time + + align:start position:0% +space-time is essentially the space-time + + + align:start position:0% +space-time is essentially the space-time +of special relativity I can find a + + align:start position:0% +of special relativity I can find a + + + align:start position:0% +of special relativity I can find a +representation so that everything looks + + align:start position:0% +representation so that everything looks + + + align:start position:0% +representation so that everything looks +just like special relativity near there + + align:start position:0% +just like special relativity near there + + + align:start position:0% +just like special relativity near there +gravity is basically completely thrown + + align:start position:0% +gravity is basically completely thrown + + + align:start position:0% +gravity is basically completely thrown +away at least as far as the mathematical + + align:start position:0% +away at least as far as the mathematical + + + align:start position:0% +away at least as far as the mathematical +representation is is concerned okay I'm + + align:start position:0% +representation is is concerned okay I'm + + + align:start position:0% +representation is is concerned okay I'm +in freefall + + align:start position:0% +in freefall + + + align:start position:0% +in freefall +I don't really see much if I want to see + + align:start position:0% +I don't really see much if I want to see + + + align:start position:0% +I don't really see much if I want to see +the impact of these waves what I need to + + align:start position:0% +the impact of these waves what I need to + + + align:start position:0% +the impact of these waves what I need to +do is think about how things behave over + + align:start position:0% +do is think about how things behave over + + + align:start position:0% +do is think about how things behave over +some finite region okay I want to put + + align:start position:0% +some finite region okay I want to put + + + align:start position:0% +some finite region okay I want to put +together a set up such that I have two + + align:start position:0% +together a set up such that I have two + + + align:start position:0% +together a set up such that I have two +bodies and those the relative effect of + + align:start position:0% +bodies and those the relative effect of + + + align:start position:0% +bodies and those the relative effect of +things between those two bodies will + + align:start position:0% +things between those two bodies will + + + align:start position:0% +things between those two bodies will +allow me to see the effect of space-time + + align:start position:0% +allow me to see the effect of space-time + + + align:start position:0% +allow me to see the effect of space-time +curvature in action + + align:start position:0% + + + + align:start position:0% + +so let's now with this in mind let's + + align:start position:0% +so let's now with this in mind let's + + + align:start position:0% +so let's now with this in mind let's +consider two nearby bodies that each + + align:start position:0% +consider two nearby bodies that each + + + align:start position:0% +consider two nearby bodies that each +follow Judy's ex so body a + + align:start position:0% + + + + align:start position:0% + +is right here and I'm going to find body + + align:start position:0% +is right here and I'm going to find body + + + align:start position:0% +is right here and I'm going to find body +a as living at the origin of my + + align:start position:0% +a as living at the origin of my + + + align:start position:0% +a as living at the origin of my +coordinates and we've got a body B over + + align:start position:0% +coordinates and we've got a body B over + + + align:start position:0% +coordinates and we've got a body B over +here and we're gonna say that this guy + + align:start position:0% +here and we're gonna say that this guy + + + align:start position:0% +here and we're gonna say that this guy +is displaced from the origin by a small + + align:start position:0% +is displaced from the origin by a small + + + align:start position:0% +is displaced from the origin by a small +amount some epsilon in what I will call + + align:start position:0% +amount some epsilon in what I will call + + + align:start position:0% +amount some epsilon in what I will call +the X direction and what I want to do is + + align:start position:0% +the X direction and what I want to do is + + + align:start position:0% +the X direction and what I want to do is +say okay I've got these two guys they + + align:start position:0% +say okay I've got these two guys they + + + align:start position:0% +say okay I've got these two guys they +are moving through a space-time let's + + align:start position:0% +are moving through a space-time let's + + + align:start position:0% +are moving through a space-time let's +make this be the space-time that we had + + align:start position:0% +make this be the space-time that we had + + + align:start position:0% +make this be the space-time that we had +discussed discussed a moment ago so they + + align:start position:0% +discussed discussed a moment ago so they + + + align:start position:0% +discussed discussed a moment ago so they +are each moving on judy's X of this + + align:start position:0% +are each moving on judy's X of this + + + align:start position:0% +are each moving on judy's X of this +space-time we know that if I set up my + + align:start position:0% +space-time we know that if I set up my + + + align:start position:0% +space-time we know that if I set up my +coordinate system and the way that I've + + align:start position:0% +coordinate system and the way that I've + + + align:start position:0% +coordinate system and the way that I've +done it here I am NOT going to see any + + align:start position:0% +done it here I am NOT going to see any + + + align:start position:0% +done it here I am NOT going to see any +acceleration on each of these bodies + + align:start position:0% +acceleration on each of these bodies + + + align:start position:0% +acceleration on each of these bodies +let's now try to focus on some kind of a + + align:start position:0% +let's now try to focus on some kind of a + + + align:start position:0% +let's now try to focus on some kind of a +some kind of a quantity that tells me + + align:start position:0% +some kind of a quantity that tells me + + + align:start position:0% +some kind of a quantity that tells me +about the separation between these two + + align:start position:0% +about the separation between these two + + + align:start position:0% +about the separation between these two +I'm going to do this in two ways so the + + align:start position:0% +I'm going to do this in two ways so the + + + align:start position:0% +I'm going to do this in two ways so the +first in which I'm going to do is say + + align:start position:0% +first in which I'm going to do is say + + + align:start position:0% +first in which I'm going to do is say +let's imagine let's imagine that I am + + align:start position:0% +let's imagine let's imagine that I am + + + align:start position:0% +let's imagine let's imagine that I am +bouncing a light pulse back and forth + + align:start position:0% +bouncing a light pulse back and forth + + + align:start position:0% +bouncing a light pulse back and forth +between a and B + + align:start position:0% + + + + align:start position:0% + +what I'm going to do is write the for + + align:start position:0% +what I'm going to do is write the for + + + align:start position:0% +what I'm going to do is write the for +momentum so she with that white so + + align:start position:0% +momentum so she with that white so + + + align:start position:0% +momentum so she with that white so +recall I can't really define a for + + align:start position:0% +recall I can't really define a for + + + align:start position:0% +recall I can't really define a for +velocity for light because proper time + + align:start position:0% +velocity for light because proper time + + + align:start position:0% +velocity for light because proper time +is not defined but I can introduce some + + align:start position:0% +is not defined but I can introduce some + + + align:start position:0% +is not defined but I can introduce some +kind of an affine parameter such that D + + align:start position:0% +kind of an affine parameter such that D + + + align:start position:0% +kind of an affine parameter such that D +by D lambda tells me about motional on + + align:start position:0% +by D lambda tells me about motional on + + + align:start position:0% +by D lambda tells me about motional on +the world line that this light follows + + align:start position:0% +the world line that this light follows + + + align:start position:0% +the world line that this light follows +and this is just bouncing back and forth + + align:start position:0% +and this is just bouncing back and forth + + + align:start position:0% +and this is just bouncing back and forth +between these two so it moves on in the + + align:start position:0% +between these two so it moves on in the + + + align:start position:0% +between these two so it moves on in the +X direction because this is light T + + align:start position:0% +X direction because this is light T + + + align:start position:0% +X direction because this is light T +equals zero + + align:start position:0% + + + + align:start position:0% + +so these components are the four + + align:start position:0% +so these components are the four + + + align:start position:0% +so these components are the four +momentum associates light the DTV lambda + + align:start position:0% +momentum associates light the DTV lambda + + + align:start position:0% +momentum associates light the DTV lambda +and the xdxd lambda they are related to + + align:start position:0% +and the xdxd lambda they are related to + + + align:start position:0% +and the xdxd lambda they are related to +each other like so and look the + + align:start position:0% +each other like so and look the + + + align:start position:0% +each other like so and look the +space-time metric the gauge invariant + + align:start position:0% +space-time metric the gauge invariant + + + align:start position:0% +space-time metric the gauge invariant +piece of the space-time hxx tt it is + + align:start position:0% +piece of the space-time hxx tt it is + + + align:start position:0% +piece of the space-time hxx tt it is +appearing in here so let's say okay what + + align:start position:0% +appearing in here so let's say okay what + + + align:start position:0% +appearing in here so let's say okay what +I am interested now is computing what + + align:start position:0% +I am interested now is computing what + + + align:start position:0% +I am interested now is computing what +suppose I'm sitting at a and I want to + + align:start position:0% +suppose I'm sitting at a and I want to + + + align:start position:0% +suppose I'm sitting at a and I want to +compute the time according to a clock + + align:start position:0% +compute the time according to a clock + + + align:start position:0% +compute the time according to a clock +that it takes for a pulse of light to + + align:start position:0% +that it takes for a pulse of light to + + + align:start position:0% +that it takes for a pulse of light to +travel from A to B maybe I'll make it + + align:start position:0% +travel from A to B maybe I'll make it + + + align:start position:0% +travel from A to B maybe I'll make it +bounce back okay may I want to know how + + align:start position:0% +bounce back okay may I want to know how + + + align:start position:0% +bounce back okay may I want to know how +much time it takes for the light poles + + align:start position:0% +much time it takes for the light poles + + + align:start position:0% +much time it takes for the light poles +to go from A to B and back to a so let's + + align:start position:0% +to go from A to B and back to a so let's + + + align:start position:0% +to go from A to B and back to a so let's +turn this into an equation for the + + align:start position:0% +turn this into an equation for the + + + align:start position:0% +turn this into an equation for the +interval DT DT so DT I can do a little + + align:start position:0% +interval DT DT so DT I can do a little + + + align:start position:0% +interval DT DT so DT I can do a little +bit of this trick called division here + + align:start position:0% +bit of this trick called division here + + + align:start position:0% +bit of this trick called division here +is yeah so I'm doing the old physicist + + align:start position:0% +is yeah so I'm doing the old physicist + + + align:start position:0% +is yeah so I'm doing the old physicist +trick I'm just imagining that an + + align:start position:0% +trick I'm just imagining that an + + + align:start position:0% +trick I'm just imagining that an +interval of time Daehyun interval of a + + align:start position:0% +interval of time Daehyun interval of a + + + align:start position:0% +interval of time Daehyun interval of a +fine parameter D lambda the amount of DT + + align:start position:0% +fine parameter D lambda the amount of DT + + + align:start position:0% +fine parameter D lambda the amount of DT +that accumulates as it moves to an + + align:start position:0% +that accumulates as it moves to an + + + align:start position:0% +that accumulates as it moves to an +interval DX they are related by so and + + align:start position:0% +interval DX they are related by so and + + + align:start position:0% +interval DX they are related by so and +remember I am assuming that the + + align:start position:0% +remember I am assuming that the + + + align:start position:0% +remember I am assuming that the +perturbation from space-time from flat + + align:start position:0% +perturbation from space-time from flat + + + align:start position:0% +perturbation from space-time from flat +space-time is small enough that I can + + align:start position:0% +space-time is small enough that I can + + + align:start position:0% +space-time is small enough that I can +always linearize so this can be I can + + align:start position:0% +always linearize so this can be I can + + + align:start position:0% +always linearize so this can be I can +take that square root using the binomial + + align:start position:0% +take that square root using the binomial + + + align:start position:0% +take that square root using the binomial +expansion so + + align:start position:0% + + + + align:start position:0% + +suppose I want to integrate up the time + + align:start position:0% +suppose I want to integrate up the time + + + align:start position:0% +suppose I want to integrate up the time +it takes for this thing to go from A to + + align:start position:0% +it takes for this thing to go from A to + + + align:start position:0% +it takes for this thing to go from A to +B and then back from B well this is + + align:start position:0% +B and then back from B well this is + + + align:start position:0% +B and then back from B well this is +going to be given by integrating this + + align:start position:0% +going to be given by integrating this + + + align:start position:0% +going to be given by integrating this +guy's motion from zero to epsilon and + + align:start position:0% +guy's motion from zero to epsilon and + + + align:start position:0% +guy's motion from zero to epsilon and +then integrating it back again it's + + align:start position:0% +then integrating it back again it's + + + align:start position:0% +then integrating it back again it's +going to switch direction when I do that + + align:start position:0% +going to switch direction when I do that + + + align:start position:0% +going to switch direction when I do that +so I'm going to flip the sign on that DX + + align:start position:0% + + + + align:start position:0% + +okay I'm leaving it written in this form + + align:start position:0% +okay I'm leaving it written in this form + + + align:start position:0% +okay I'm leaving it written in this form +to be a little bit careful you guys will + + align:start position:0% +to be a little bit careful you guys will + + + align:start position:0% +to be a little bit careful you guys will +play with this a little bit more on a + + align:start position:0% +play with this a little bit more on a + + + align:start position:0% +play with this a little bit more on a +problem set bear in mind that as I move + + align:start position:0% +problem set bear in mind that as I move + + + align:start position:0% +problem set bear in mind that as I move +through X the time argument of these + + align:start position:0% +through X the time argument of these + + + align:start position:0% +through X the time argument of these +guys is changing okay and so that's + + align:start position:0% +guys is changing okay and so that's + + + align:start position:0% +guys is changing okay and so that's +where there's a little bit of work that + + align:start position:0% +where there's a little bit of work that + + + align:start position:0% +where there's a little bit of work that +you'll explore on a problem set but I'm + + align:start position:0% +you'll explore on a problem set but I'm + + + align:start position:0% +you'll explore on a problem set but I'm +writing it in this form so that we get + + align:start position:0% +writing it in this form so that we get + + + align:start position:0% +writing it in this form so that we get +some you naively you might think oh okay + + align:start position:0% +some you naively you might think oh okay + + + align:start position:0% +some you naively you might think oh okay +I'll just flip the sign and I'll combine + + align:start position:0% +I'll just flip the sign and I'll combine + + + align:start position:0% +I'll just flip the sign and I'll combine +these and a certain limit that is indeed + + align:start position:0% +these and a certain limit that is indeed + + + align:start position:0% +these and a certain limit that is indeed +a good approximation got to be a little + + align:start position:0% +a good approximation got to be a little + + + align:start position:0% +a good approximation got to be a little +bit more careful in general though this + + align:start position:0% +bit more careful in general though this + + + align:start position:0% +bit more careful in general though this +is the time it would take for light to + + align:start position:0% +is the time it would take for light to + + + align:start position:0% +is the time it would take for light to +go from A to B in back in the absence of + + align:start position:0% +go from A to B in back in the absence of + + + align:start position:0% +go from A to B in back in the absence of +this gravitational wave this h XX TTA + + align:start position:0% +this gravitational wave this h XX TTA + + + align:start position:0% +this gravitational wave this h XX TTA +notice there is an inference on the time + + align:start position:0% +notice there is an inference on the time + + + align:start position:0% +notice there is an inference on the time +of arrival of these pulses that depends + + align:start position:0% +of arrival of these pulses that depends + + + align:start position:0% +of arrival of these pulses that depends +on HX xt t time arrival of the pulses + + align:start position:0% + + + + align:start position:0% + +depends on this particular piece of the + + align:start position:0% +depends on this particular piece of the + + + align:start position:0% +depends on this particular piece of the +space-time metric one could imagine if + + align:start position:0% +space-time metric one could imagine if + + + align:start position:0% +space-time metric one could imagine if +you had a precise clock and you sat + + align:start position:0% +you had a precise clock and you sat + + + align:start position:0% +you had a precise clock and you sat +there and you time the arrival of these + + align:start position:0% +there and you time the arrival of these + + + align:start position:0% +there and you time the arrival of these +things let's say you sent a pulse of + + align:start position:0% +things let's say you sent a pulse of + + + align:start position:0% +things let's say you sent a pulse of +light out Boop and you kept track of how + + align:start position:0% +light out Boop and you kept track of how + + + align:start position:0% +light out Boop and you kept track of how +long it took with a very precise clock + + align:start position:0% +long it took with a very precise clock + + + align:start position:0% +long it took with a very precise clock +you could look for in the absolute + + align:start position:0% +you could look for in the absolute + + + align:start position:0% +you could look for in the absolute +gravitational wave that would be if you + + align:start position:0% +gravitational wave that would be if you + + + align:start position:0% +gravitational wave that would be if you +imagine that your pulse was sent out + + align:start position:0% +imagine that your pulse was sent out + + + align:start position:0% +imagine that your pulse was sent out +perfectly periodically let's say every + + align:start position:0% + + + + align:start position:0% + +every millisecond or something like that + + align:start position:0% +every millisecond or something like that + + + align:start position:0% +every millisecond or something like that +you sent out a little pulse if it + + align:start position:0% +you sent out a little pulse if it + + + align:start position:0% +you sent out a little pulse if it +arrived back and your arrival pulses + + align:start position:0% +arrived back and your arrival pulses + + + align:start position:0% +arrived back and your arrival pulses +were just as spaced by one millisecond + + align:start position:0% +were just as spaced by one millisecond + + + align:start position:0% +were just as spaced by one millisecond +you would say great I am sitting in + + align:start position:0% +you would say great I am sitting in + + + align:start position:0% +you would say great I am sitting in +empty space time but if you found that + + align:start position:0% +empty space time but if you found that + + + align:start position:0% +empty space time but if you found that +their arrivals varied + + align:start position:0% +their arrivals varied + + + align:start position:0% +their arrivals varied +you'd say hmm there's something else + + align:start position:0% +you'd say hmm there's something else + + + align:start position:0% +you'd say hmm there's something else +going on here gravitational waves is one + + align:start position:0% +going on here gravitational waves is one + + + align:start position:0% +going on here gravitational waves is one +of things that could lead to that + + align:start position:0% +of things that could lead to that + + + align:start position:0% +of things that could lead to that +variation so this at least is kind of a + + align:start position:0% +variation so this at least is kind of a + + + align:start position:0% +variation so this at least is kind of a +proof this calculation I just did you + + align:start position:0% +proof this calculation I just did you + + + align:start position:0% +proof this calculation I just did you +guys are actually on one of the upcoming + + align:start position:0% +guys are actually on one of the upcoming + + + align:start position:0% +guys are actually on one of the upcoming +problem sets believe it's problems + + align:start position:0% +problem sets believe it's problems + + + align:start position:0% +problem sets believe it's problems +anywhere for seven or eight you do a + + align:start position:0% +anywhere for seven or eight you do a + + + align:start position:0% +anywhere for seven or eight you do a +little analysis where you will use this + + align:start position:0% +little analysis where you will use this + + + align:start position:0% +little analysis where you will use this +to understand how a detector like LIGO + + align:start position:0% +to understand how a detector like LIGO + + + align:start position:0% +to understand how a detector like LIGO +actually functions to measure out the + + align:start position:0% +actually functions to measure out the + + + align:start position:0% +actually functions to measure out the +effect due to gravitational wave on the + + align:start position:0% +effect due to gravitational wave on the + + + align:start position:0% +effect due to gravitational wave on the +arms of a detector like this let me just + + align:start position:0% +arms of a detector like this let me just + + + align:start position:0% +arms of a detector like this let me just +do one more way of understanding how it + + align:start position:0% +do one more way of understanding how it + + + align:start position:0% +do one more way of understanding how it +is the gravitational wave leaves an + + align:start position:0% +is the gravitational wave leaves an + + + align:start position:0% +is the gravitational wave leaves an +imprint on these two separated particles + + align:start position:0% + + + + align:start position:0% + +so when you look at that first naive + + align:start position:0% +so when you look at that first naive + + + align:start position:0% +so when you look at that first naive +calculation I did the fact that I got no + + align:start position:0% +calculation I did the fact that I got no + + + align:start position:0% +calculation I did the fact that I got no +effect + + align:start position:0% +effect + + + align:start position:0% +effect +I sort of joked that we did a dumb + + align:start position:0% +I sort of joked that we did a dumb + + + align:start position:0% +I sort of joked that we did a dumb +calculation to be fair it wasn't that + + align:start position:0% +calculation to be fair it wasn't that + + + align:start position:0% +calculation to be fair it wasn't that +dumb okay what weird the first thing you + + align:start position:0% +dumb okay what weird the first thing you + + + align:start position:0% +dumb okay what weird the first thing you +usually think of doing when you want to + + align:start position:0% +usually think of doing when you want to + + + align:start position:0% +usually think of doing when you want to +understand the motion of the body in + + align:start position:0% +understand the motion of the body in + + + align:start position:0% +understand the motion of the body in +space-time as you look at Judy's ex + + align:start position:0% +space-time as you look at Judy's ex + + + align:start position:0% +space-time as you look at Judy's ex +Judy's acceleration with respect to the + + align:start position:0% +Judy's acceleration with respect to the + + + align:start position:0% +Judy's acceleration with respect to the +freefall frame is zero and that's + + align:start position:0% +freefall frame is zero and that's + + + align:start position:0% +freefall frame is zero and that's +exactly what we end up getting it's + + align:start position:0% +exactly what we end up getting it's + + + align:start position:0% +exactly what we end up getting it's +basically just saying ah even in a + + align:start position:0% +basically just saying ah even in a + + + align:start position:0% +basically just saying ah even in a +gravitational wave my two bodies are + + align:start position:0% +gravitational wave my two bodies are + + + align:start position:0% +gravitational wave my two bodies are +moving on Judy's ex if I have two + + align:start position:0% +moving on Judy's ex if I have two + + + align:start position:0% +moving on Judy's ex if I have two +separated bodies like I have in this + + align:start position:0% +separated bodies like I have in this + + + align:start position:0% +separated bodies like I have in this +calculation where I just calculated the + + align:start position:0% +calculation where I just calculated the + + + align:start position:0% +calculation where I just calculated the +variation in the time of arrival of + + align:start position:0% +variation in the time of arrival of + + + align:start position:0% +variation in the time of arrival of +light pulses one of the tools we learned + + align:start position:0% +light pulses one of the tools we learned + + + align:start position:0% +light pulses one of the tools we learned +is that I can have - Judy's x2 freefall + + align:start position:0% +is that I can have - Judy's x2 freefall + + + align:start position:0% +is that I can have - Judy's x2 freefall +trajectories that deviate from one + + align:start position:0% +trajectories that deviate from one + + + align:start position:0% +trajectories that deviate from one +another so let's look at the Judy's ik + + align:start position:0% +another so let's look at the Judy's ik + + + align:start position:0% +another so let's look at the Judy's ik +deviation of the freefall world lines of + + align:start position:0% +deviation of the freefall world lines of + + + align:start position:0% +deviation of the freefall world lines of +these two bodies + + align:start position:0% + + + + align:start position:0% + +so I'm gonna as I did when I did my + + align:start position:0% +so I'm gonna as I did when I did my + + + align:start position:0% +so I'm gonna as I did when I did my +Judy's a calculation I'm going to take + + align:start position:0% +Judy's a calculation I'm going to take + + + align:start position:0% +Judy's a calculation I'm going to take +them to initially be close enough that + + align:start position:0% +them to initially be close enough that + + + align:start position:0% +them to initially be close enough that +they have the same for velocity and if + + align:start position:0% +they have the same for velocity and if + + + align:start position:0% +they have the same for velocity and if +you want to be careful about counting + + align:start position:0% +you want to be careful about counting + + + align:start position:0% +you want to be careful about counting +orders here you can imagine when the + + align:start position:0% +orders here you can imagine when the + + + align:start position:0% +orders here you can imagine when the +gravitational wave comes along that one + + align:start position:0% +gravitational wave comes along that one + + + align:start position:0% +gravitational wave comes along that one +or both of them might pick up a + + align:start position:0% +or both of them might pick up a + + + align:start position:0% +or both of them might pick up a +correction of this that's an order H + + align:start position:0% +correction of this that's an order H + + + align:start position:0% +correction of this that's an order H +okay depends on what kind of coordinate + + align:start position:0% +okay depends on what kind of coordinate + + + align:start position:0% +okay depends on what kind of coordinate +system you pick up but the key thing is + + align:start position:0% +system you pick up but the key thing is + + + align:start position:0% +system you pick up but the key thing is +that they start out like this the + + align:start position:0% +that they start out like this the + + + align:start position:0% +that they start out like this the +gravitational wave may come along and it + + align:start position:0% +gravitational wave may come along and it + + + align:start position:0% +gravitational wave may come along and it +will move them around a little bit okay + + align:start position:0% +will move them around a little bit okay + + + align:start position:0% +will move them around a little bit okay +but the amount is going to move them the + + align:start position:0% +but the amount is going to move them the + + + align:start position:0% +but the amount is going to move them the +amount of velocity that they're gonna + + align:start position:0% +amount of velocity that they're gonna + + + align:start position:0% +amount of velocity that they're gonna +pick up not displacement they're going + + align:start position:0% +pick up not displacement they're going + + + align:start position:0% +pick up not displacement they're going +to get from their initial position if + + align:start position:0% +to get from their initial position if + + + align:start position:0% +to get from their initial position if +they're at rest it can only be of order + + align:start position:0% +they're at rest it can only be of order + + + align:start position:0% +they're at rest it can only be of order +the H that you're trying to measure + + align:start position:0% +the H that you're trying to measure + + + align:start position:0% +the H that you're trying to measure +there so I'll remind you the equation of + + align:start position:0% +there so I'll remind you the equation of + + + align:start position:0% +there so I'll remind you the equation of +daeviation equation of Gd is a deviation + + align:start position:0% + + + + align:start position:0% + +it defines a sort of proper acceleration + + align:start position:0% +it defines a sort of proper acceleration + + + align:start position:0% +it defines a sort of proper acceleration +acting on whoops that's a typo it is the + + align:start position:0% +acting on whoops that's a typo it is the + + + align:start position:0% +acting on whoops that's a typo it is the +proper cell acceleration on a vector C + + align:start position:0% +proper cell acceleration on a vector C + + + align:start position:0% +proper cell acceleration on a vector C +that defines in a precise geometric way + + align:start position:0% +that defines in a precise geometric way + + + align:start position:0% +that defines in a precise geometric way +the separation of two geodesics + + align:start position:0% + + + + align:start position:0% + +and what it looks like is the Riemann + + align:start position:0% +and what it looks like is the Riemann + + + align:start position:0% +and what it looks like is the Riemann +curvature of your space-time contracted + + align:start position:0% +curvature of your space-time contracted + + + align:start position:0% +curvature of your space-time contracted +on the for velocity of your bodies and + + align:start position:0% +on the for velocity of your bodies and + + + align:start position:0% +on the for velocity of your bodies and +that separation vector C so linearizing + + align:start position:0% +that separation vector C so linearizing + + + align:start position:0% +that separation vector C so linearizing +everything bearing in mind that our will + + align:start position:0% +everything bearing in mind that our will + + + align:start position:0% +everything bearing in mind that our will +itself be of order H and that's any + + align:start position:0% +itself be of order H and that's any + + + align:start position:0% +itself be of order H and that's any +difference between the proper time along + + align:start position:0% +difference between the proper time along + + + align:start position:0% +difference between the proper time along +these things and the coordinate time if + + align:start position:0% +these things and the coordinate time if + + + align:start position:0% +these things and the coordinate time if +a particular clock is also gonna be of + + align:start position:0% +a particular clock is also gonna be of + + + align:start position:0% +a particular clock is also gonna be of +order H they are small enough that this + + align:start position:0% +order H they are small enough that this + + + align:start position:0% +order H they are small enough that this +equation becomes it looks like this + + align:start position:0% +equation becomes it looks like this + + + align:start position:0% +equation becomes it looks like this +notice I'm only looking at the spatial + + align:start position:0% +notice I'm only looking at the spatial + + + align:start position:0% +notice I'm only looking at the spatial +components of the separation vector C ok + + align:start position:0% +components of the separation vector C ok + + + align:start position:0% +components of the separation vector C ok +that's because since I'm working since + + align:start position:0% +that's because since I'm working since + + + align:start position:0% +that's because since I'm working since +this is what my floor velocity looks + + align:start position:0% +this is what my floor velocity looks + + + align:start position:0% +this is what my floor velocity looks +like I'm gonna pick out the 0 0 + + align:start position:0% +like I'm gonna pick out the 0 0 + + + align:start position:0% +like I'm gonna pick out the 0 0 +components of these things and don't + + align:start position:0% +components of these things and don't + + + align:start position:0% +components of these things and don't +forget Limon is anti-symmetric when I + + align:start position:0% +forget Limon is anti-symmetric when I + + + align:start position:0% +forget Limon is anti-symmetric when I +exchange either indices 1 & 2 or indices + + align:start position:0% +exchange either indices 1 & 2 or indices + + + align:start position:0% +exchange either indices 1 & 2 or indices +3 & 4 and because of that it's just the + + align:start position:0% +3 & 4 and because of that it's just the + + + align:start position:0% +3 & 4 and because of that it's just the +time light component of this guy is + + align:start position:0% +time light component of this guy is + + + align:start position:0% +time light component of this guy is +going to be an uninteresting thing I + + align:start position:0% +going to be an uninteresting thing I + + + align:start position:0% +going to be an uninteresting thing I +will just get that is equal to the + + align:start position:0% +will just get that is equal to the + + + align:start position:0% +will just get that is equal to the +acceleration of the time light component + + align:start position:0% +acceleration of the time light component + + + align:start position:0% +acceleration of the time light component +is zero so it doesn't really matter okay + + align:start position:0% +is zero so it doesn't really matter okay + + + align:start position:0% +is zero so it doesn't really matter okay +so this is telling me that the judy's + + align:start position:0% +so this is telling me that the judy's + + + align:start position:0% +so this is telling me that the judy's +except eration of these two world lines + + align:start position:0% +except eration of these two world lines + + + align:start position:0% +except eration of these two world lines +is it's a second-order equation in time + + align:start position:0% +is it's a second-order equation in time + + + align:start position:0% +is it's a second-order equation in time +and it's proportional to the separation + + align:start position:0% +and it's proportional to the separation + + + align:start position:0% +and it's proportional to the separation +itself we need to work out all of these + + align:start position:0% +itself we need to work out all of these + + + align:start position:0% +itself we need to work out all of these +complex + + align:start position:0% + + + + align:start position:0% + +that is a fairly straightforward + + align:start position:0% +that is a fairly straightforward + + + align:start position:0% +that is a fairly straightforward +exercise and I would just report to you + + align:start position:0% +exercise and I would just report to you + + + align:start position:0% +exercise and I would just report to you +the results brief aside if you wants to + + align:start position:0% +the results brief aside if you wants to + + + align:start position:0% +the results brief aside if you wants to +sort of verify the results I'm about to + + align:start position:0% +sort of verify the results I'm about to + + + align:start position:0% +sort of verify the results I'm about to +write out here you could go into you + + align:start position:0% +write out here you could go into you + + + align:start position:0% +write out here you could go into you +could look up the definition of the + + align:start position:0% +could look up the definition of the + + + align:start position:0% +could look up the definition of the +Riemann tensor bear in mind that you are + + align:start position:0% +Riemann tensor bear in mind that you are + + + align:start position:0% +Riemann tensor bear in mind that you are +doing things at linear orders you can + + align:start position:0% +doing things at linear orders you can + + + align:start position:0% +doing things at linear orders you can +throw away the terms of like connection + + align:start position:0% +throw away the terms of like connection + + + align:start position:0% +throw away the terms of like connection +times connection it's just derivatives + + align:start position:0% +times connection it's just derivatives + + + align:start position:0% +times connection it's just derivatives +of the connection that are going to + + align:start position:0% +of the connection that are going to + + + align:start position:0% +of the connection that are going to +matter at linear order but even so it's + + align:start position:0% +matter at linear order but even so it's + + + align:start position:0% +matter at linear order but even so it's +you know it's a bit of a bit of a grotty + + align:start position:0% +you know it's a bit of a bit of a grotty + + + align:start position:0% +you know it's a bit of a bit of a grotty +calculation I am as I begin to + + align:start position:0% +calculation I am as I begin to + + + align:start position:0% +calculation I am as I begin to +reorganize the problem sets associated + + align:start position:0% +reorganize the problem sets associated + + + align:start position:0% +reorganize the problem sets associated +with this class under the new system + + align:start position:0% +with this class under the new system + + + align:start position:0% +with this class under the new system +that MIT is currently operating on I + + align:start position:0% +that MIT is currently operating on I + + + align:start position:0% +that MIT is currently operating on I +will soon be releasing a few Mathematica + + align:start position:0% +will soon be releasing a few Mathematica + + + align:start position:0% +will soon be releasing a few Mathematica +notebooks that are very useful tools for + + align:start position:0% +notebooks that are very useful tools for + + + align:start position:0% +notebooks that are very useful tools for +doing tedious calculations like + + align:start position:0% +doing tedious calculations like + + + align:start position:0% +doing tedious calculations like +computation of Riemann curvature tensor + + align:start position:0% +computation of Riemann curvature tensor + + + align:start position:0% +computation of Riemann curvature tensor +components okay so I will put a few of + + align:start position:0% +components okay so I will put a few of + + + align:start position:0% +components okay so I will put a few of +those things up there if you would like + + align:start position:0% +those things up there if you would like + + + align:start position:0% +those things up there if you would like +to validate some of the things that I am + + align:start position:0% +to validate some of the things that I am + + + align:start position:0% +to validate some of the things that I am +computing that is where you will find a + + align:start position:0% +computing that is where you will find a + + + align:start position:0% +computing that is where you will find a +good way to test this so anyway the + + align:start position:0% +good way to test this so anyway the + + + align:start position:0% +good way to test this so anyway the +non-zero Riemann components so at linear + + align:start position:0% +non-zero Riemann components so at linear + + + align:start position:0% +non-zero Riemann components so at linear +order you have are X 0 X 0 bear in mind + + align:start position:0% +order you have are X 0 X 0 bear in mind + + + align:start position:0% +order you have are X 0 X 0 bear in mind +that linear order you are raising and + + align:start position:0% +that linear order you are raising and + + + align:start position:0% +that linear order you are raising and +lowering indices with the metric of flat + + align:start position:0% +lowering indices with the metric of flat + + + align:start position:0% +lowering indices with the metric of flat +space-time so that's the same thing as + + align:start position:0% +space-time so that's the same thing as + + + align:start position:0% +space-time so that's the same thing as +this and this turns out to be minus 1/2 + + align:start position:0% +this and this turns out to be minus 1/2 + + + align:start position:0% +this and this turns out to be minus 1/2 +to time derivatives of H X X + + align:start position:0% + + + + align:start position:0% + +y 0 y 0 your yo-yo component pretty much + + align:start position:0% +y 0 y 0 your yo-yo component pretty much + + + align:start position:0% +y 0 y 0 your yo-yo component pretty much +looks exactly the same but it's to time + + align:start position:0% +looks exactly the same but it's to time + + + align:start position:0% +looks exactly the same but it's to time +derivatives of the YY piece remember + + align:start position:0% +derivatives of the YY piece remember + + + align:start position:0% +derivatives of the YY piece remember +though I've erased it a while ago there + + align:start position:0% +though I've erased it a while ago there + + + align:start position:0% +though I've erased it a while ago there +are some constraints that we found due + + align:start position:0% +are some constraints that we found due + + + align:start position:0% +are some constraints that we found due +to the fact that my original H mu nu has + + align:start position:0% +to the fact that my original H mu nu has + + + align:start position:0% +to the fact that my original H mu nu has +to be its spatial piece has to be + + align:start position:0% +to be its spatial piece has to be + + + align:start position:0% +to be its spatial piece has to be +traceless in particular we found h YY + + align:start position:0% +traceless in particular we found h YY + + + align:start position:0% +traceless in particular we found h YY +was minus HX X so I can remove that + + align:start position:0% +was minus HX X so I can remove that + + + align:start position:0% +was minus HX X so I can remove that +additional function and just leave + + align:start position:0% +additional function and just leave + + + align:start position:0% +additional function and just leave +things in terms of HX X and our final + + align:start position:0% +things in terms of HX X and our final + + + align:start position:0% +things in terms of HX X and our final +nonzero component looks like this all + + align:start position:0% +nonzero component looks like this all + + + align:start position:0% +nonzero component looks like this all +others are either 0 or related by a + + align:start position:0% +others are either 0 or related by a + + + align:start position:0% +others are either 0 or related by a +symmetry so notice although I've written + + align:start position:0% +symmetry so notice although I've written + + + align:start position:0% +symmetry so notice although I've written +down three different components here + + align:start position:0% +down three different components here + + + align:start position:0% +down three different components here +there's only only two ok because the + + align:start position:0% +there's only only two ok because the + + + align:start position:0% +there's only only two ok because the +symmetry that that's you know it's not a + + align:start position:0% +symmetry that that's you know it's not a + + + align:start position:0% +symmetry that that's you know it's not a +symmetry of Rima but the symmetry + + align:start position:0% +symmetry of Rima but the symmetry + + + align:start position:0% +symmetry of Rima but the symmetry +associated with the trace free nature of + + align:start position:0% +associated with the trace free nature of + + + align:start position:0% +associated with the trace free nature of +h idat t made these two equal to each + + align:start position:0% +h idat t made these two equal to each + + + align:start position:0% +h idat t made these two equal to each +other so this and this are really the + + align:start position:0% +other so this and this are really the + + + align:start position:0% +other so this and this are really the +only independent degrees of freedom here + + align:start position:0% + + + + align:start position:0% + +alright let's plug this into the + + align:start position:0% +alright let's plug this into the + + + align:start position:0% +alright let's plug this into the +equation of G DS deviation this guy and + + align:start position:0% +equation of G DS deviation this guy and + + + align:start position:0% +equation of G DS deviation this guy and +see what we got + + align:start position:0% +see what we got + + + align:start position:0% +see what we got +so what we get is an equation governing + + align:start position:0% +so what we get is an equation governing + + + align:start position:0% +so what we get is an equation governing +the acceleration of the X component of + + align:start position:0% +the acceleration of the X component of + + + align:start position:0% +the acceleration of the X component of +deviation + + align:start position:0% + + + + align:start position:0% + +here it is let's make a couple of + + align:start position:0% +here it is let's make a couple of + + + align:start position:0% +here it is let's make a couple of +assumptions and try to understand what + + align:start position:0% +assumptions and try to understand what + + + align:start position:0% +assumptions and try to understand what +this is telling us so what I'm going to + + align:start position:0% +this is telling us so what I'm going to + + + align:start position:0% +this is telling us so what I'm going to +do is let's assume this is the first + + align:start position:0% +do is let's assume this is the first + + + align:start position:0% +do is let's assume this is the first +assumption is necessitated by the idea + + align:start position:0% +assumption is necessitated by the idea + + + align:start position:0% +assumption is necessitated by the idea +that I can do linearized gravity so I'm + + align:start position:0% +that I can do linearized gravity so I'm + + + align:start position:0% +that I can do linearized gravity so I'm +gonna assume that these guys are all + + align:start position:0% +gonna assume that these guys are all + + + align:start position:0% +gonna assume that these guys are all +very small and I will imagine that my + + align:start position:0% +very small and I will imagine that my + + + align:start position:0% +very small and I will imagine that my +displacement vectors have some piece + + align:start position:0% +displacement vectors have some piece + + + align:start position:0% +displacement vectors have some piece +which basically is time constant okay it + + align:start position:0% +which basically is time constant okay it + + + align:start position:0% +which basically is time constant okay it +does not change and that there's a bit + + align:start position:0% +does not change and that there's a bit + + + align:start position:0% +does not change and that there's a bit +that will be of order H that describes + + align:start position:0% +that will be of order H that describes + + + align:start position:0% +that will be of order H that describes +how the separation of my two bodies + + align:start position:0% +how the separation of my two bodies + + + align:start position:0% +how the separation of my two bodies +responds to this incoming field okay so + + align:start position:0% +responds to this incoming field okay so + + + align:start position:0% +responds to this incoming field okay so +what I'm gonna do when you go and you + + align:start position:0% +what I'm gonna do when you go and you + + + align:start position:0% +what I'm gonna do when you go and you +plug this in assume that this guy is + + align:start position:0% +plug this in assume that this guy is + + + align:start position:0% +plug this in assume that this guy is +constant in time and this one varies + + align:start position:0% + + + + align:start position:0% + +what I'm going to do is imagine I don't + + align:start position:0% +what I'm going to do is imagine I don't + + + align:start position:0% +what I'm going to do is imagine I don't +just have two bodies imagine I have a + + align:start position:0% +just have two bodies imagine I have a + + + align:start position:0% +just have two bodies imagine I have a +ring of bodies okay so suppose I have + + align:start position:0% +ring of bodies okay so suppose I have + + + align:start position:0% +ring of bodies okay so suppose I have +got to make coordinate axes here + + align:start position:0% +got to make coordinate axes here + + + align:start position:0% +got to make coordinate axes here +horizontal is X vertical and the board + + align:start position:0% +horizontal is X vertical and the board + + + align:start position:0% +horizontal is X vertical and the board +is y and so imagine I have a ring of + + align:start position:0% +is y and so imagine I have a ring of + + + align:start position:0% +is y and so imagine I have a ring of +bodies like so and let's consider the + + align:start position:0% +bodies like so and let's consider the + + + align:start position:0% +bodies like so and let's consider the +following limit let's imagine that my HX + + align:start position:0% +following limit let's imagine that my HX + + + align:start position:0% +following limit let's imagine that my HX +X is some function that is sinusoidally + + align:start position:0% +X is some function that is sinusoidally + + + align:start position:0% +X is some function that is sinusoidally +varying in time and my H X Y is zero + + align:start position:0% +varying in time and my H X Y is zero + + + align:start position:0% +varying in time and my H X Y is zero +okay I just want to call at the as we + + align:start position:0% +okay I just want to call at the as we + + + align:start position:0% +okay I just want to call at the as we +saw there's really only two degrees of + + align:start position:0% +saw there's really only two degrees of + + + align:start position:0% +saw there's really only two degrees of +freedom in this field and in the way + + align:start position:0% +freedom in this field and in the way + + + align:start position:0% +freedom in this field and in the way +that we formulated it it's gonna be + + align:start position:0% +that we formulated it it's gonna be + + + align:start position:0% +that we formulated it it's gonna be +encapsulated by these two functions xx + + align:start position:0% +encapsulated by these two functions xx + + + align:start position:0% +encapsulated by these two functions xx +and XY so let's just look at one let's + + align:start position:0% +and XY so let's just look at one let's + + + align:start position:0% +and XY so let's just look at one let's +just look at the influence of the HX X + + align:start position:0% +just look at the influence of the HX X + + + align:start position:0% +just look at the influence of the HX X +okay so when you do this you essentially + + align:start position:0% +okay so when you do this you essentially + + + align:start position:0% +okay so when you do this you essentially +have the second derivative of CX looks + + align:start position:0% +have the second derivative of CX looks + + + align:start position:0% +have the second derivative of CX looks +like two derivatives of your X field + + align:start position:0% +like two derivatives of your X field + + + align:start position:0% +like two derivatives of your X field +your X X field x CX and two derivatives + + align:start position:0% +your X X field x CX and two derivatives + + + align:start position:0% +your X X field x CX and two derivatives +you're sort of acceleration in the Y + + align:start position:0% +you're sort of acceleration in the Y + + + align:start position:0% +you're sort of acceleration in the Y +Direction is minus those two derivatives + + align:start position:0% +Direction is minus those two derivatives + + + align:start position:0% +Direction is minus those two derivatives +of your field times CY so what this is + + align:start position:0% +of your field times CY so what this is + + + align:start position:0% +of your field times CY so what this is +going to do if you think about the way + + align:start position:0% +going to do if you think about the way + + + align:start position:0% +going to do if you think about the way +this is going to act on these things + + align:start position:0% +this is going to act on these things + + + align:start position:0% +this is going to act on these things +you're gonna get a sinusoidal + + align:start position:0% +you're gonna get a sinusoidal + + + align:start position:0% +you're gonna get a sinusoidal +acceleration associated with the + + align:start position:0% +acceleration associated with the + + + align:start position:0% +acceleration associated with the +displacement of this little sea of + + align:start position:0% +displacement of this little sea of + + + align:start position:0% +displacement of this little sea of +freely falling bodies as the gravitation + + align:start position:0% +freely falling bodies as the gravitation + + + align:start position:0% +freely falling bodies as the gravitation +wave comes along and it's going to do so + + align:start position:0% +wave comes along and it's going to do so + + + align:start position:0% +wave comes along and it's going to do so +in such a way that the displacement in + + align:start position:0% +in such a way that the displacement in + + + align:start position:0% +in such a way that the displacement in +the X direction does the opposite of + + align:start position:0% +the X direction does the opposite of + + + align:start position:0% +the X direction does the opposite of +what the displacement in the Y direction + + align:start position:0% +what the displacement in the Y direction + + + align:start position:0% +what the displacement in the Y direction +is doing so as time passes + + align:start position:0% + + + + align:start position:0% + +you'll find that so initially let's say + + align:start position:0% +you'll find that so initially let's say + + + align:start position:0% +you'll find that so initially let's say +it stretches along X but then squeezes + + align:start position:0% +it stretches along X but then squeezes + + + align:start position:0% +it stretches along X but then squeezes +along Y it's a sinusoid so quarter of a + + align:start position:0% +along Y it's a sinusoid so quarter of a + + + align:start position:0% +along Y it's a sinusoid so quarter of a +cycle later it's back to being a circle + + align:start position:0% +cycle later it's back to being a circle + + + align:start position:0% +cycle later it's back to being a circle +and quarter of a second later it + + align:start position:0% +and quarter of a second later it + + + align:start position:0% +and quarter of a second later it +stretches along Y and squeeze those + + align:start position:0% +stretches along Y and squeeze those + + + align:start position:0% +stretches along Y and squeeze those +along X let's consider the limit now + + align:start position:0% +along X let's consider the limit now + + + align:start position:0% +along X let's consider the limit now +where H xx is equal to zero and H X Y is + + align:start position:0% +where H xx is equal to zero and H X Y is + + + align:start position:0% +where H xx is equal to zero and H X Y is +some sinusoid so I start out with my + + align:start position:0% +some sinusoid so I start out with my + + + align:start position:0% +some sinusoid so I start out with my +circle look at your equations over here + + align:start position:0% +circle look at your equations over here + + + align:start position:0% +circle look at your equations over here +think about what they're going to do now + + align:start position:0% +think about what they're going to do now + + + align:start position:0% +think about what they're going to do now +we're going to find that the change in X + + align:start position:0% +we're going to find that the change in X + + + align:start position:0% +we're going to find that the change in X +and the change in Y is correlated so + + align:start position:0% +and the change in Y is correlated so + + + align:start position:0% +and the change in Y is correlated so +this guy stretches it out into an + + align:start position:0% +this guy stretches it out into an + + + align:start position:0% +this guy stretches it out into an +ellipse along a 45-degree line cycle + + align:start position:0% +ellipse along a 45-degree line cycle + + + align:start position:0% +ellipse along a 45-degree line cycle +later it's back to being a circle and a + + align:start position:0% +later it's back to being a circle and a + + + align:start position:0% +later it's back to being a circle and a +quarter of a second later it does the + + align:start position:0% +quarter of a second later it does the + + + align:start position:0% +quarter of a second later it does the +same thing with opposite sign these two + + align:start position:0% +same thing with opposite sign these two + + + align:start position:0% +same thing with opposite sign these two +fields my HX X and my H XY are what we + + align:start position:0% +fields my HX X and my H XY are what we + + + align:start position:0% +fields my HX X and my H XY are what we +call the fundamental polarizations of + + align:start position:0% +call the fundamental polarizations of + + + align:start position:0% +call the fundamental polarizations of +the gravitational wave + + align:start position:0% + + + + align:start position:0% + +polarization states are only defined + + align:start position:0% +polarization states are only defined + + + align:start position:0% +polarization states are only defined +with respect to a particular set of + + align:start position:0% +with respect to a particular set of + + + align:start position:0% +with respect to a particular set of +basis basis vectors so if I make my + + align:start position:0% +basis basis vectors so if I make my + + + align:start position:0% +basis basis vectors so if I make my +basis vectors B this x and y we call + + align:start position:0% +basis vectors B this x and y we call + + + align:start position:0% +basis vectors B this x and y we call +this one for reasons that I hope are + + align:start position:0% +this one for reasons that I hope are + + + align:start position:0% +this one for reasons that I hope are +obvious the plus polarization okay + + align:start position:0% +obvious the plus polarization okay + + + align:start position:0% +obvious the plus polarization okay +the gravitational waves acts as a tidal + + align:start position:0% +the gravitational waves acts as a tidal + + + align:start position:0% +the gravitational waves acts as a tidal +stretch and squeeze notice what's going + + align:start position:0% +stretch and squeeze notice what's going + + + align:start position:0% +stretch and squeeze notice what's going +on here I stretch along this axis + + align:start position:0% +on here I stretch along this axis + + + align:start position:0% +on here I stretch along this axis +squeeze along this one quarter of a + + align:start position:0% +squeeze along this one quarter of a + + + align:start position:0% +squeeze along this one quarter of a +second ladle later I squeeze along this + + align:start position:0% +second ladle later I squeeze along this + + + align:start position:0% +second ladle later I squeeze along this +one stretch along that one so I get a + + align:start position:0% +one stretch along that one so I get a + + + align:start position:0% +one stretch along that one so I get a +title stretch and squeeze where the main + + align:start position:0% +title stretch and squeeze where the main + + + align:start position:0% +title stretch and squeeze where the main +directions along which the stretch and + + align:start position:0% +directions along which the stretch and + + + align:start position:0% +directions along which the stretch and +squeeze are happening is plus shaped + + align:start position:0% +squeeze are happening is plus shaped + + + align:start position:0% +squeeze are happening is plus shaped +with respect to these axes this one is + + align:start position:0% +with respect to these axes this one is + + + align:start position:0% +with respect to these axes this one is +known as the cross polarization you also + + align:start position:0% +known as the cross polarization you also + + + align:start position:0% +known as the cross polarization you also +have a tidal stretch and squeeze but the + + align:start position:0% +have a tidal stretch and squeeze but the + + + align:start position:0% +have a tidal stretch and squeeze but the +lines of force in this case are along + + align:start position:0% +lines of force in this case are along + + + align:start position:0% +lines of force in this case are along +axes that have a an X shape + + align:start position:0% + + + + align:start position:0% + +so level of eight 962 this is this is + + align:start position:0% +so level of eight 962 this is this is + + + align:start position:0% +so level of eight 962 this is this is +all we're gonna say about the way that + + align:start position:0% +all we're gonna say about the way that + + + align:start position:0% +all we're gonna say about the way that +these things act on how gravitational + + align:start position:0% +these things act on how gravitational + + + align:start position:0% +these things act on how gravitational +waves act and what their observables are + + align:start position:0% +waves act and what their observables are + + + align:start position:0% +waves act and what their observables are +and I deliberately chose to wear my LIGO + + align:start position:0% +and I deliberately chose to wear my LIGO + + + align:start position:0% +and I deliberately chose to wear my LIGO +hat today because what LIGO does is look + + align:start position:0% +hat today because what LIGO does is look + + + align:start position:0% +hat today because what LIGO does is look +for these tidal stretches and squeezes + + align:start position:0% +for these tidal stretches and squeezes + + + align:start position:0% +for these tidal stretches and squeezes +the way it does so so obviously you it's + + align:start position:0% +the way it does so so obviously you it's + + + align:start position:0% +the way it does so so obviously you it's +technologically not really feasible to + + align:start position:0% +technologically not really feasible to + + + align:start position:0% +technologically not really feasible to +set up a ring like this but what you can + + align:start position:0% +set up a ring like this but what you can + + + align:start position:0% +set up a ring like this but what you can +do is sample the ring here in here it's + + align:start position:0% +do is sample the ring here in here it's + + + align:start position:0% +do is sample the ring here in here it's +a little bit better to do on the plus + + align:start position:0% +a little bit better to do on the plus + + + align:start position:0% +a little bit better to do on the plus +crawl ization plot so you make an + + align:start position:0% +crawl ization plot so you make an + + + align:start position:0% +crawl ization plot so you make an +experimental setup that samples the ring + + align:start position:0% +experimental setup that samples the ring + + + align:start position:0% +experimental setup that samples the ring +here in here and if a gravitational wave + + align:start position:0% +here in here and if a gravitational wave + + + align:start position:0% +here in here and if a gravitational wave +comes along and it's lined up right you + + align:start position:0% +comes along and it's lined up right you + + + align:start position:0% +comes along and it's lined up right you +see oh look at that I'm getting that + + align:start position:0% +see oh look at that I'm getting that + + + align:start position:0% +see oh look at that I'm getting that +stretch and squeeze the way you actually + + align:start position:0% +stretch and squeeze the way you actually + + + align:start position:0% +stretch and squeeze the way you actually +measure it out is essentially a timing + + align:start position:0% +measure it out is essentially a timing + + + align:start position:0% +measure it out is essentially a timing +experiment exactly like this little + + align:start position:0% +experiment exactly like this little + + + align:start position:0% +experiment exactly like this little +calculation I did here you bounce light + + align:start position:0% +calculation I did here you bounce light + + + align:start position:0% +calculation I did here you bounce light +between mirrors and you very carefully + + align:start position:0% +between mirrors and you very carefully + + + align:start position:0% +between mirrors and you very carefully +time the the round-trip travel time from + + align:start position:0% +time the the round-trip travel time from + + + align:start position:0% +time the the round-trip travel time from +one mirror to the other and what's + + align:start position:0% +one mirror to the other and what's + + + align:start position:0% +one mirror to the other and what's +particularly cool is the experimental + + align:start position:0% +particularly cool is the experimental + + + align:start position:0% +particularly cool is the experimental +aspect of this so how does one measure + + align:start position:0% +aspect of this so how does one measure + + + align:start position:0% +aspect of this so how does one measure +the time so precisely well you use a + + align:start position:0% +the time so precisely well you use a + + + align:start position:0% +the time so precisely well you use a +laser beam as your clock and what's + + align:start position:0% +laser beam as your clock and what's + + + align:start position:0% +laser beam as your clock and what's +beautiful about doing that is the way + + align:start position:0% +beautiful about doing that is the way + + + align:start position:0% +beautiful about doing that is the way +that you can actually sort of do the + + align:start position:0% +that you can actually sort of do the + + + align:start position:0% +that you can actually sort of do the +metrology at the level necessary to get + + align:start position:0% +metrology at the level necessary to get + + + align:start position:0% +metrology at the level necessary to get +the precision to measure your HX X's in + + align:start position:0% +the precision to measure your HX X's in + + + align:start position:0% +the precision to measure your HX X's in +here is by interference okay so you can + + align:start position:0% +here is by interference okay so you can + + + align:start position:0% +here is by interference okay so you can +treat the incoming laser beam is + + align:start position:0% +treat the incoming laser beam is + + + align:start position:0% +treat the incoming laser beam is +defining your time standard and then by + + align:start position:0% +defining your time standard and then by + + + align:start position:0% +defining your time standard and then by +interfering the the light that has + + align:start position:0% +interfering the the light that has + + + align:start position:0% +interfering the the light that has +traveled down the arm and bounced back + + align:start position:0% +traveled down the arm and bounced back + + + align:start position:0% +traveled down the arm and bounced back +with that laser beam the basically + + align:start position:0% +with that laser beam the basically + + + align:start position:0% +with that laser beam the basically +the laws of nature allow you to + + align:start position:0% +the laws of nature allow you to + + + align:start position:0% +the laws of nature allow you to +automatically check and see whether + + align:start position:0% +automatically check and see whether + + + align:start position:0% +automatically check and see whether +there is a shift in the time of arrival + + align:start position:0% +there is a shift in the time of arrival + + + align:start position:0% +there is a shift in the time of arrival +associated with the action of the + + align:start position:0% +associated with the action of the + + + align:start position:0% +associated with the action of the +gravitational wave so I imagine there'll + + align:start position:0% +gravitational wave so I imagine there'll + + + align:start position:0% +gravitational wave so I imagine there'll +be some questions about this um there + + align:start position:0% +be some questions about this um there + + + align:start position:0% +be some questions about this um there +are there is a homework exercise that + + align:start position:0% +are there is a homework exercise that + + + align:start position:0% +are there is a homework exercise that +allows you to sort of test drive some of + + align:start position:0% +allows you to sort of test drive some of + + + align:start position:0% +allows you to sort of test drive some of +these concepts and allows you to see how + + align:start position:0% +these concepts and allows you to see how + + + align:start position:0% +these concepts and allows you to see how +it is that Lyle works it really just + + align:start position:0% +it is that Lyle works it really just + + + align:start position:0% +it is that Lyle works it really just +sort of touches this it just scratches + + align:start position:0% +sort of touches this it just scratches + + + align:start position:0% +sort of touches this it just scratches +the surface of what an amazing + + align:start position:0% +the surface of what an amazing + + + align:start position:0% +the surface of what an amazing +experimental feat that is but it should + + align:start position:0% +experimental feat that is but it should + + + align:start position:0% +experimental feat that is but it should +give you a good idea as to what goes + + align:start position:0% +give you a good idea as to what goes + + + align:start position:0% +give you a good idea as to what goes +into that now there's an important part + + align:start position:0% +into that now there's an important part + + + align:start position:0% +into that now there's an important part +to all this that we've not talked about + + align:start position:0% +to all this that we've not talked about + + + align:start position:0% +to all this that we've not talked about +yet I handed you + + align:start position:0% +yet I handed you + + + align:start position:0% +yet I handed you +hij really I handed uhm you know the big + + align:start position:0% +hij really I handed uhm you know the big + + + align:start position:0% +hij really I handed uhm you know the big +thing that we care about + + align:start position:0% +thing that we care about + + + align:start position:0% +thing that we care about +next is given a particular source how do + + align:start position:0% +next is given a particular source how do + + + align:start position:0% +next is given a particular source how do +i compute this radiation field so + + align:start position:0% +i compute this radiation field so + + + align:start position:0% +i compute this radiation field so +bearing in mind that h IJ t t this is + + align:start position:0% +bearing in mind that h IJ t t this is + + + align:start position:0% +bearing in mind that h IJ t t this is +the gauge invariant radiative degree of + + align:start position:0% +the gauge invariant radiative degree of + + + align:start position:0% +the gauge invariant radiative degree of +freedom in my space-time how do i + + align:start position:0% +freedom in my space-time how do i + + + align:start position:0% +freedom in my space-time how do i +compute this guy and what i'm going to + + align:start position:0% +compute this guy and what i'm going to + + + align:start position:0% +compute this guy and what i'm going to +do is borrow the sort of one most + + align:start position:0% +do is borrow the sort of one most + + + align:start position:0% +do is borrow the sort of one most +important lessons of that gauge + + align:start position:0% +important lessons of that gauge + + + align:start position:0% +important lessons of that gauge +invariant formalism + + align:start position:0% + + + + align:start position:0% + +so we need to be cautious of the fact + + align:start position:0% +so we need to be cautious of the fact + + + align:start position:0% +so we need to be cautious of the fact +that in some gauges for example the + + align:start position:0% +that in some gauges for example the + + + align:start position:0% +that in some gauges for example the +Lorentz gauge which is so convenient for + + align:start position:0% +Lorentz gauge which is so convenient for + + + align:start position:0% +Lorentz gauge which is so convenient for +solving the Einstein equations + + align:start position:0% + + + + align:start position:0% + +components of the metric appear to be + + align:start position:0% +components of the metric appear to be + + + align:start position:0% +components of the metric appear to be +radiative whether they are or they + + align:start position:0% +radiative whether they are or they + + + align:start position:0% +radiative whether they are or they +aren't this is a consequence of our + + align:start position:0% +aren't this is a consequence of our + + + align:start position:0% +aren't this is a consequence of our +gauge but we also know only hij TT is + + align:start position:0% +gauge but we also know only hij TT is + + + align:start position:0% +gauge but we also know only hij TT is +radiation in all gauges so that was what + + align:start position:0% +radiation in all gauges so that was what + + + align:start position:0% +radiation in all gauges so that was what +the previous lecture was about as I've + + align:start position:0% +the previous lecture was about as I've + + + align:start position:0% +the previous lecture was about as I've +emphasized it was a slightly advanced + + align:start position:0% +emphasized it was a slightly advanced + + + align:start position:0% +emphasized it was a slightly advanced +one I don't expect everyone to follow + + align:start position:0% +one I don't expect everyone to follow + + + align:start position:0% +one I don't expect everyone to follow +all details but if you can sort of grok + + align:start position:0% +all details but if you can sort of grok + + + align:start position:0% +all details but if you can sort of grok +these two main concepts you're ready to + + align:start position:0% +these two main concepts you're ready to + + + align:start position:0% +these two main concepts you're ready to +now exploit this in the following way + + align:start position:0% + + + + align:start position:0% + +what you do is a compute find some + + align:start position:0% +what you do is a compute find some + + + align:start position:0% +what you do is a compute find some +metric perturbation in any convenient + + align:start position:0% +metric perturbation in any convenient + + + align:start position:0% +metric perturbation in any convenient +gauge by any convenient method + + align:start position:0% + + + + align:start position:0% + +once you have that extract hij TT you're + + align:start position:0% +once you have that extract hij TT you're + + + align:start position:0% +once you have that extract hij TT you're +done so that's what we're gonna do right + + align:start position:0% +done so that's what we're gonna do right + + + align:start position:0% +done so that's what we're gonna do right +now in the last 20 or so minutes of this + + align:start position:0% +now in the last 20 or so minutes of this + + + align:start position:0% +now in the last 20 or so minutes of this +recorded lecture + + align:start position:0% + + + + align:start position:0% + +so we're going to do it is let's take + + align:start position:0% +so we're going to do it is let's take + + + align:start position:0% +so we're going to do it is let's take +the linear Eisenstein equation in + + align:start position:0% +the linear Eisenstein equation in + + + align:start position:0% +the linear Eisenstein equation in +Lorentz gauge as we showed in I believe + + align:start position:0% +Lorentz gauge as we showed in I believe + + + align:start position:0% +Lorentz gauge as we showed in I believe +it was two lectures ago the I sign field + + align:start position:0% +it was two lectures ago the I sign field + + + align:start position:0% +it was two lectures ago the I sign field +equations in this case we've used two + + align:start position:0% +equations in this case we've used two + + + align:start position:0% +equations in this case we've used two +flat space-time wave operator on the + + align:start position:0% +flat space-time wave operator on the + + + align:start position:0% +flat space-time wave operator on the +trace reversed metric perturbation being + + align:start position:0% +trace reversed metric perturbation being + + + align:start position:0% +trace reversed metric perturbation being +up to a factor of minus sixteen pi g the + + align:start position:0% +up to a factor of minus sixteen pi g the + + + align:start position:0% +up to a factor of minus sixteen pi g the +stress energy tensor and this has an + + align:start position:0% +stress energy tensor and this has an + + + align:start position:0% +stress energy tensor and this has an +exact solution + + align:start position:0% + + + + align:start position:0% + +I'll remind you this notation so this is + + align:start position:0% +I'll remind you this notation so this is + + + align:start position:0% +I'll remind you this notation so this is +the field at time T and spatial location + + align:start position:0% +the field at time T and spatial location + + + align:start position:0% +the field at time T and spatial location +X X and T well great like this T and X + + align:start position:0% +X X and T well great like this T and X + + + align:start position:0% +X X and T well great like this T and X +are my field point that is where I + + align:start position:0% +are my field point that is where I + + + align:start position:0% +are my field point that is where I +measure my field X prime is my source + + align:start position:0% +measure my field X prime is my source + + + align:start position:0% +measure my field X prime is my source +point that is where I'm looking at my + + align:start position:0% +point that is where I'm looking at my + + + align:start position:0% +point that is where I'm looking at my +particular contribution to the integral + + align:start position:0% +particular contribution to the integral + + + align:start position:0% +particular contribution to the integral +as we were doing this calculation there + + align:start position:0% +as we were doing this calculation there + + + align:start position:0% +as we were doing this calculation there +was a t prime but the rate of greens + + align:start position:0% +was a t prime but the rate of greens + + + align:start position:0% +was a t prime but the rate of greens +function turned that T prime into this + + align:start position:0% +function turned that T prime into this + + + align:start position:0% +function turned that T prime into this + time so what we're seeing is + + align:start position:0% + time so what we're seeing is + + + align:start position:0% + time so what we're seeing is +that the field at T depends upon what's + + align:start position:0% +that the field at T depends upon what's + + + align:start position:0% +that the field at T depends upon what's +going on at the source at t minus the + + align:start position:0% +going on at the source at t minus the + + + align:start position:0% +going on at the source at t minus the +interval of time it takes for + + align:start position:0% +interval of time it takes for + + + align:start position:0% +interval of time it takes for +information to propagate from X prime to + + align:start position:0% +information to propagate from X prime to + + + align:start position:0% +information to propagate from X prime to +X so what I'm going to do is first I'm + + align:start position:0% +X so what I'm going to do is first I'm + + + align:start position:0% +X so what I'm going to do is first I'm +going to introduce a couple of + + align:start position:0% +going to introduce a couple of + + + align:start position:0% +going to introduce a couple of +approximations that reflect the reality + + align:start position:0% +approximations that reflect the reality + + + align:start position:0% +approximations that reflect the reality +of the conditions under which we + + align:start position:0% +of the conditions under which we + + + align:start position:0% +of the conditions under which we +typically evaluate this integral and + + align:start position:0% +typically evaluate this integral and + + + align:start position:0% +typically evaluate this integral and +then we're going to talk about how to + + align:start position:0% +then we're going to talk about how to + + + align:start position:0% +then we're going to talk about how to +solve this thing + + align:start position:0% +solve this thing + + + align:start position:0% +solve this thing +and given that we've now solved it how + + align:start position:0% +and given that we've now solved it how + + + align:start position:0% +and given that we've now solved it how +to project out the gauge invariant + + align:start position:0% +to project out the gauge invariant + + + align:start position:0% +to project out the gauge invariant +degrees of freedom associated with the + + align:start position:0% +degrees of freedom associated with the + + + align:start position:0% +degrees of freedom associated with the +radiation + + align:start position:0% + + + + align:start position:0% + +so first as I introduced its + + align:start position:0% +so first as I introduced its + + + align:start position:0% +so first as I introduced its +approximation it's worth bearing in mind + + align:start position:0% +approximation it's worth bearing in mind + + + align:start position:0% +approximation it's worth bearing in mind +that when you are calculating this X + + align:start position:0% +that when you are calculating this X + + + align:start position:0% +that when you are calculating this X +minus X prime which is kind of like the + + align:start position:0% +minus X prime which is kind of like the + + + align:start position:0% +minus X prime which is kind of like the +distance from a particular point in the + + align:start position:0% +distance from a particular point in the + + + align:start position:0% +distance from a particular point in the +source to where you're making your + + align:start position:0% +source to where you're making your + + + align:start position:0% +source to where you're making your +measurement it is generally a lot larger + + align:start position:0% +measurement it is generally a lot larger + + + align:start position:0% +measurement it is generally a lot larger +than the size of the source okay so the + + align:start position:0% +than the size of the source okay so the + + + align:start position:0% +than the size of the source okay so the +kind of situation we're thinking about + + align:start position:0% +kind of situation we're thinking about + + + align:start position:0% +kind of situation we're thinking about +is here we are making our measurements + + align:start position:0% +is here we are making our measurements + + + align:start position:0% +is here we are making our measurements +at some point X here here's my source + + align:start position:0% +at some point X here here's my source + + + align:start position:0% +at some point X here here's my source +and here's a point X Prime inside the + + align:start position:0% +and here's a point X Prime inside the + + + align:start position:0% +and here's a point X Prime inside the +source okay so the same to bear in mind + + align:start position:0% +source okay so the same to bear in mind + + + align:start position:0% +source okay so the same to bear in mind +is that for the kind of calculations + + align:start position:0% +is that for the kind of calculations + + + align:start position:0% +is that for the kind of calculations +where that you know and when one is + + align:start position:0% +where that you know and when one is + + + align:start position:0% +where that you know and when one is +actually doing this X minus X prime well + + align:start position:0% +actually doing this X minus X prime well + + + align:start position:0% +actually doing this X minus X prime well +if I think about the kind of + + align:start position:0% +if I think about the kind of + + + align:start position:0% +if I think about the kind of +measurements that LIGO is doing for + + align:start position:0% +measurements that LIGO is doing for + + + align:start position:0% +measurements that LIGO is doing for +example that is typically hundreds of + + align:start position:0% +example that is typically hundreds of + + + align:start position:0% +example that is typically hundreds of +millions to billions of light years the + + align:start position:0% +millions to billions of light years the + + + align:start position:0% +millions to billions of light years the +size of the source itself is of order + + align:start position:0% +size of the source itself is of order + + + align:start position:0% +size of the source itself is of order +tens to hundreds of kilometers bit of a + + align:start position:0% +tens to hundreds of kilometers bit of a + + + align:start position:0% +tens to hundreds of kilometers bit of a +separation of length scales there you + + align:start position:0% +separation of length scales there you + + + align:start position:0% +separation of length scales there you +would say so what I'm going to do is + + align:start position:0% + + + + align:start position:0% + +approximate the solution that integral + + align:start position:0% +approximate the solution that integral + + + align:start position:0% +approximate the solution that integral +and for pedantic sake I'm gonna use an + + align:start position:0% +and for pedantic sake I'm gonna use an + + + align:start position:0% +and for pedantic sake I'm gonna use an +approximately equal what I'm going to do + + align:start position:0% +approximately equal what I'm going to do + + + align:start position:0% +approximately equal what I'm going to do +is replace X minus X Prime with our + + align:start position:0% +is replace X minus X Prime with our + + + align:start position:0% +is replace X minus X Prime with our +let's just say that this distance here + + align:start position:0% +let's just say that this distance here + + + align:start position:0% +let's just say that this distance here +it's effectively the same for all points + + align:start position:0% +it's effectively the same for all points + + + align:start position:0% +it's effectively the same for all points +in the source I can pull that out of the + + align:start position:0% +in the source I can pull that out of the + + + align:start position:0% +in the source I can pull that out of the +integral + + align:start position:0% + + + + align:start position:0% + +okay if you like you can refine this + + align:start position:0% +okay if you like you can refine this + + + align:start position:0% +okay if you like you can refine this +there's a more careful expansion and if + + align:start position:0% +there's a more careful expansion and if + + + align:start position:0% +there's a more careful expansion and if +you've done any electrodynamics you + + align:start position:0% +you've done any electrodynamics you + + + align:start position:0% +you've done any electrodynamics you +should be familiar with this and it uses + + align:start position:0% +should be familiar with this and it uses + + + align:start position:0% +should be familiar with this and it uses +the fact that 1 over X minus X prime can + + align:start position:0% +the fact that 1 over X minus X prime can + + + align:start position:0% +the fact that 1 over X minus X prime can +be expanded in Legendre polynomials in a + + align:start position:0% +be expanded in Legendre polynomials in a + + + align:start position:0% +be expanded in Legendre polynomials in a +sum over Legendre polynomials ok so if + + align:start position:0% +sum over Legendre polynomials ok so if + + + align:start position:0% +sum over Legendre polynomials ok so if +you do that you can introduce + + align:start position:0% +you do that you can introduce + + + align:start position:0% +you do that you can introduce +refinements to what I'm about to derive + + align:start position:0% +refinements to what I'm about to derive + + + align:start position:0% +refinements to what I'm about to derive +right here what this does then is it + + align:start position:0% +right here what this does then is it + + + align:start position:0% +right here what this does then is it +defines a multipolar expansion I am NOT + + align:start position:0% +defines a multipolar expansion I am NOT + + + align:start position:0% +defines a multipolar expansion I am NOT +going to do that I'm just going to look + + align:start position:0% +going to do that I'm just going to look + + + align:start position:0% +going to do that I'm just going to look +at the very first term and you can sort + + align:start position:0% +at the very first term and you can sort + + + align:start position:0% +at the very first term and you can sort +of think of that as saying that I am + + align:start position:0% +of think of that as saying that I am + + + align:start position:0% +of think of that as saying that I am +just doing the leading the most + + align:start position:0% +just doing the leading the most + + + align:start position:0% +just doing the leading the most +important multiple additional multiples + + align:start position:0% +important multiple additional multiples + + + align:start position:0% +important multiple additional multiples +beyond that are certainly important and + + align:start position:0% +beyond that are certainly important and + + + align:start position:0% +beyond that are certainly important and +people who work in the field of + + align:start position:0% +people who work in the field of + + + align:start position:0% +people who work in the field of +gravitational radiation we certainly do + + align:start position:0% +gravitational radiation we certainly do + + + align:start position:0% +gravitational radiation we certainly do +not neglect them in fact much of my + + align:start position:0% +not neglect them in fact much of my + + + align:start position:0% +not neglect them in fact much of my +current research is based on sort of + + align:start position:0% +current research is based on sort of + + + align:start position:0% +current research is based on sort of +high order calculations associated with + + align:start position:0% +high order calculations associated with + + + align:start position:0% +high order calculations associated with +looking at behavior some of those some + + align:start position:0% +looking at behavior some of those some + + + align:start position:0% +looking at behavior some of those some +of those multiples this will be fine for + + align:start position:0% +of those multiples this will be fine for + + + align:start position:0% +of those multiples this will be fine for +initial pedagogical purposes next we're + + align:start position:0% +initial pedagogical purposes next we're + + + align:start position:0% +initial pedagogical purposes next we're +gonna use the fact that only the spatial + + align:start position:0% +gonna use the fact that only the spatial + + + align:start position:0% +gonna use the fact that only the spatial +whoops that's not suppose to be an H + + align:start position:0% +whoops that's not suppose to be an H + + + align:start position:0% +whoops that's not suppose to be an H +tilde my apologies + + align:start position:0% +tilde my apologies + + + align:start position:0% +tilde my apologies +just be H bark this is the Tracy first + + align:start position:0% +just be H bark this is the Tracy first + + + align:start position:0% +just be H bark this is the Tracy first +thing weird times folks okay uh what was + + align:start position:0% +thing weird times folks okay uh what was + + + align:start position:0% +thing weird times folks okay uh what was +I at yes so I am only going to care + + align:start position:0% +I at yes so I am only going to care + + + align:start position:0% +I at yes so I am only going to care +about the spatial pieces of this okay + + align:start position:0% +about the spatial pieces of this okay + + + align:start position:0% +about the spatial pieces of this okay +you might protest hey isn't it the + + align:start position:0% +you might protest hey isn't it the + + + align:start position:0% +you might protest hey isn't it the +spatial part of the metric not the trace + + align:start position:0% +spatial part of the metric not the trace + + + align:start position:0% +spatial part of the metric not the trace +reverse metric that matters and you + + align:start position:0% +reverse metric that matters and you + + + align:start position:0% +reverse metric that matters and you +would be correct if you do this + + align:start position:0% +would be correct if you do this + + + align:start position:0% +would be correct if you do this +carefully to be perfectly blunt you have + + align:start position:0% +carefully to be perfectly blunt you have + + + align:start position:0% +carefully to be perfectly blunt you have +to sort of finish the calculation before + + align:start position:0% +to sort of finish the calculation before + + + align:start position:0% +to sort of finish the calculation before +you can kind of justify the step I'm + + align:start position:0% +you can kind of justify the step I'm + + + align:start position:0% +you can kind of justify the step I'm +about to make and we're not gonna have + + align:start position:0% +about to make and we're not gonna have + + + align:start position:0% +about to make and we're not gonna have +time to do that very carefully but I'll + + align:start position:0% +time to do that very carefully but I'll + + + align:start position:0% +time to do that very carefully but I'll +make a comment about it for now it + + align:start position:0% +make a comment about it for now it + + + align:start position:0% +make a comment about it for now it +suffice to say we only care about the + + align:start position:0% +suffice to say we only care about the + + + align:start position:0% +suffice to say we only care about the +spatial components so I'm gonna take my + + align:start position:0% +spatial components so I'm gonna take my + + + align:start position:0% +spatial components so I'm gonna take my +alpha beta over to an IJ okay so I now + + align:start position:0% +alpha beta over to an IJ okay so I now + + + align:start position:0% +alpha beta over to an IJ okay so I now +have something that involves the + + align:start position:0% +have something that involves the + + + align:start position:0% +have something that involves the +integral of the spatial pieces of the + + align:start position:0% +integral of the spatial pieces of the + + + align:start position:0% +integral of the spatial pieces of the +stress energy tensor over my source and + + align:start position:0% +stress energy tensor over my source and + + + align:start position:0% +stress energy tensor over my source and +now I'm going to take advantage of an + + align:start position:0% +now I'm going to take advantage of an + + + align:start position:0% +now I'm going to take advantage of an +Easter egg that was hidden in an early + + align:start position:0% +Easter egg that was hidden in an early + + + align:start position:0% +Easter egg that was hidden in an early +problem set back on problem set two I + + align:start position:0% +problem set back on problem set two I + + + align:start position:0% +problem set back on problem set two I +asked you to prove a result that I + + align:start position:0% +asked you to prove a result that I + + + align:start position:0% +asked you to prove a result that I +called the tensor virial theorem + + align:start position:0% + + + + align:start position:0% + +one of the reasons why I signed that was + + align:start position:0% +one of the reasons why I signed that was + + + align:start position:0% +one of the reasons why I signed that was +that I knew I was going to need it in + + align:start position:0% +that I knew I was going to need it in + + + align:start position:0% +that I knew I was going to need it in +this lecture and what the tensor virial + + align:start position:0% +this lecture and what the tensor virial + + + align:start position:0% +this lecture and what the tensor virial +theorem told us is that if I integrate + + align:start position:0% + + + + align:start position:0% + +that this ends up being equivalent to + + align:start position:0% +that this ends up being equivalent to + + + align:start position:0% +that this ends up being equivalent to +one half two time derivatives equal to + + align:start position:0% +one half two time derivatives equal to + + + align:start position:0% +one half two time derivatives equal to +the integral of two time derivatives + + align:start position:0% +the integral of two time derivatives + + + align:start position:0% +the integral of two time derivatives +assuming it's two time rhythms of the + + align:start position:0% +assuming it's two time rhythms of the + + + align:start position:0% +assuming it's two time rhythms of the +integral of the zero zero piece of my + + align:start position:0% +integral of the zero zero piece of my + + + align:start position:0% +integral of the zero zero piece of my +stress energy tensor sort of the second + + align:start position:0% +stress energy tensor sort of the second + + + align:start position:0% +stress energy tensor sort of the second +moment of that X I prime XJ prime okay + + align:start position:0% +moment of that X I prime XJ prime okay + + + align:start position:0% +moment of that X I prime XJ prime okay +this is great because what I've got on + + align:start position:0% +this is great because what I've got on + + + align:start position:0% +this is great because what I've got on +the left hand side here that's exactly + + align:start position:0% +the left hand side here that's exactly + + + align:start position:0% +the left hand side here that's exactly +what my integral is you know what this + + align:start position:0% +what my integral is you know what this + + + align:start position:0% +what my integral is you know what this +is going to give me a result that + + align:start position:0% +is going to give me a result that + + + align:start position:0% +is going to give me a result that +sufficiently clean I want a new board so + + align:start position:0% +sufficiently clean I want a new board so + + + align:start position:0% +sufficiently clean I want a new board so +when that is done + + align:start position:0% + + + + align:start position:0% + +what I finally see is that my H I J + + align:start position:0% +what I finally see is that my H I J + + + align:start position:0% +what I finally see is that my H I J +trace you first is to G over our two + + align:start position:0% +trace you first is to G over our two + + + align:start position:0% +trace you first is to G over our two +time derivatives of a tensor that I will + + align:start position:0% +time derivatives of a tensor that I will + + + align:start position:0% +time derivatives of a tensor that I will +call i IJ this is what I get when I + + align:start position:0% +call i IJ this is what I get when I + + + align:start position:0% +call i IJ this is what I get when I +integrate T 0 0 to moments of T 0 0 this + + align:start position:0% +integrate T 0 0 to moments of T 0 0 this + + + align:start position:0% +integrate T 0 0 to moments of T 0 0 this +is called the quadrupole moment the + + align:start position:0% +is called the quadrupole moment the + + + align:start position:0% +is called the quadrupole moment the +source the asterisk is because as you + + align:start position:0% +source the asterisk is because as you + + + align:start position:0% +source the asterisk is because as you +guys will see on one of the problem sets + + align:start position:0% +guys will see on one of the problem sets + + + align:start position:0% +guys will see on one of the problem sets +there's a slight tweak that goes into + + align:start position:0% +there's a slight tweak that goes into + + + align:start position:0% +there's a slight tweak that goes into +the exact definition of the quadrupole + + align:start position:0% +the exact definition of the quadrupole + + + align:start position:0% +the exact definition of the quadrupole +moment which has to do with the behavior + + align:start position:0% +moment which has to do with the behavior + + + align:start position:0% +moment which has to do with the behavior +of the trace of I I J I will just leave + + align:start position:0% +of the trace of I I J I will just leave + + + align:start position:0% +of the trace of I I J I will just leave +this like so for now and leave you guys + + align:start position:0% +this like so for now and leave you guys + + + align:start position:0% +this like so for now and leave you guys +to explore that on the problem set so + + align:start position:0% +to explore that on the problem set so + + + align:start position:0% +to explore that on the problem set so +we're almost done what I now need to do + + align:start position:0% +we're almost done what I now need to do + + + align:start position:0% +we're almost done what I now need to do +is pull out the transverse and traceless + + align:start position:0% +is pull out the transverse and traceless + + + align:start position:0% +is pull out the transverse and traceless +piece of this + + align:start position:0% + + + + align:start position:0% + +let's consider the transverse condition + + align:start position:0% +let's consider the transverse condition + + + align:start position:0% +let's consider the transverse condition +first + + align:start position:0% + + + + align:start position:0% + +so to do the transverse condition I'm + + align:start position:0% +so to do the transverse condition I'm + + + align:start position:0% +so to do the transverse condition I'm +gonna take advantage of the fact that + + align:start position:0% +gonna take advantage of the fact that + + + align:start position:0% +gonna take advantage of the fact that +far from the source box h bar IJ is + + align:start position:0% +far from the source box h bar IJ is + + + align:start position:0% +far from the source box h bar IJ is +equal to zero these because I'm in a + + align:start position:0% +equal to zero these because I'm in a + + + align:start position:0% +equal to zero these because I'm in a +region where the source is equal to zero + + align:start position:0% +region where the source is equal to zero + + + align:start position:0% +region where the source is equal to zero +when I'm far away from it this suggests + + align:start position:0% +when I'm far away from it this suggests + + + align:start position:0% +when I'm far away from it this suggests +that what we ought to do is expand our + + align:start position:0% +that what we ought to do is expand our + + + align:start position:0% +that what we ought to do is expand our +solution implant in plain ways so what I + + align:start position:0% +solution implant in plain ways so what I + + + align:start position:0% +solution implant in plain ways so what I +can do is write H bar and choose my + + align:start position:0% +can do is write H bar and choose my + + + align:start position:0% +can do is write H bar and choose my +indices carefully here clot JL it's some + + align:start position:0% +indices carefully here clot JL it's some + + + align:start position:0% +indices carefully here clot JL it's some +amplitude that does not depend on space + + align:start position:0% +amplitude that does not depend on space + + + align:start position:0% +amplitude that does not depend on space +or time e to the I Omega t minus a wave + + align:start position:0% +or time e to the I Omega t minus a wave + + + align:start position:0% +or time e to the I Omega t minus a wave +vector dotted with X okay so this + + align:start position:0% +vector dotted with X okay so this + + + align:start position:0% +vector dotted with X okay so this +amplitude may depend on Omega it may + + align:start position:0% +amplitude may depend on Omega it may + + + align:start position:0% +amplitude may depend on Omega it may +depend on K it does not depend on T or + + align:start position:0% +depend on K it does not depend on T or + + + align:start position:0% +depend on K it does not depend on T or +on X and the reason I changed my indices + + align:start position:0% +on X and the reason I changed my indices + + + align:start position:0% +on X and the reason I changed my indices +from I and J - J and L I did not use the + + align:start position:0% +from I and J - J and L I did not use the + + + align:start position:0% +from I and J - J and L I did not use the +index K is just to avoid confusion + + align:start position:0% +index K is just to avoid confusion + + + align:start position:0% +index K is just to avoid confusion +between square root of -1 and the wave + + align:start position:0% +between square root of -1 and the wave + + + align:start position:0% +between square root of -1 and the wave +vector to be absolutely careful this is + + align:start position:0% +vector to be absolutely careful this is + + + align:start position:0% +vector to be absolutely careful this is +a single mode okay if you like maybe you + + align:start position:0% +a single mode okay if you like maybe you + + + align:start position:0% +a single mode okay if you like maybe you +should think about this as something + + align:start position:0% +should think about this as something + + + align:start position:0% +should think about this as something +that I have I'm doing a sum or an + + align:start position:0% +that I have I'm doing a sum or an + + + align:start position:0% +that I have I'm doing a sum or an +integral over Omega and K in order to + + align:start position:0% +integral over Omega and K in order to + + + align:start position:0% +integral over Omega and K in order to +reconstruct the whole thing this is just + + align:start position:0% +reconstruct the whole thing this is just + + + align:start position:0% +reconstruct the whole thing this is just +a single Fourier mode in the wave field + + align:start position:0% +a single Fourier mode in the wave field + + + align:start position:0% +a single Fourier mode in the wave field +so if I want this to be transverse that + + align:start position:0% +so if I want this to be transverse that + + + align:start position:0% +so if I want this to be transverse that +condition is that the divergence of this + + align:start position:0% +condition is that the divergence of this + + + align:start position:0% +condition is that the divergence of this +guy be equal to zero okay but when I + + align:start position:0% +guy be equal to zero okay but when I + + + align:start position:0% +guy be equal to zero okay but when I +take the divergence of this + + align:start position:0% + + + + align:start position:0% + +this becomes I pull down a factor of + + align:start position:0% +this becomes I pull down a factor of + + + align:start position:0% +this becomes I pull down a factor of +minus I and I pull down the J component + + align:start position:0% +minus I and I pull down the J component + + + align:start position:0% +minus I and I pull down the J component +of my wave vector K and I get my wave my + + align:start position:0% +of my wave vector K and I get my wave my + + + align:start position:0% +of my wave vector K and I get my wave my +for a term that can be thought of as so + + align:start position:0% +for a term that can be thought of as so + + + align:start position:0% +for a term that can be thought of as so +we can clear out the factor of minus I + + align:start position:0% + + + + align:start position:0% + +the transverse condition boils down to + + align:start position:0% +the transverse condition boils down to + + + align:start position:0% +the transverse condition boils down to +saying that KJ KJ contracted on the wave + + align:start position:0% +saying that KJ KJ contracted on the wave + + + align:start position:0% +saying that KJ KJ contracted on the wave +field is equal to zero in other words + + align:start position:0% +field is equal to zero in other words + + + align:start position:0% +field is equal to zero in other words +the wave field is orthogonal to the wave + + align:start position:0% +the wave field is orthogonal to the wave + + + align:start position:0% +the wave field is orthogonal to the wave +vector + + align:start position:0% + + + + align:start position:0% + +if you have studied electrodynamics this + + align:start position:0% +if you have studied electrodynamics this + + + align:start position:0% +if you have studied electrodynamics this +should be familiar to you this is the + + align:start position:0% +should be familiar to you this is the + + + align:start position:0% +should be familiar to you this is the +same it's exactly the same as the idea + + align:start position:0% +same it's exactly the same as the idea + + + align:start position:0% +same it's exactly the same as the idea +that when I have an electromagnetic wave + + align:start position:0% +that when I have an electromagnetic wave + + + align:start position:0% +that when I have an electromagnetic wave +my e field in my B field are orthogonal + + align:start position:0% +my e field in my B field are orthogonal + + + align:start position:0% +my e field in my B field are orthogonal +to the direction of propagation let's + + align:start position:0% +to the direction of propagation let's + + + align:start position:0% +to the direction of propagation let's +define a unit vector and sub J to be KJ + + align:start position:0% +define a unit vector and sub J to be KJ + + + align:start position:0% +define a unit vector and sub J to be KJ +but just normalized okay so my wave is + + align:start position:0% +but just normalized okay so my wave is + + + align:start position:0% +but just normalized okay so my wave is +propagating in the direction of the unit + + align:start position:0% +propagating in the direction of the unit + + + align:start position:0% +propagating in the direction of the unit +vector n go back to another Easter egg + + align:start position:0% +vector n go back to another Easter egg + + + align:start position:0% +vector n go back to another Easter egg +that was hitting on an earlier problem + + align:start position:0% +that was hitting on an earlier problem + + + align:start position:0% +that was hitting on an earlier problem +set you guys studied projection tensors + + align:start position:0% + + + + align:start position:0% + +if I introduced the projection tensor P + + align:start position:0% +if I introduced the projection tensor P + + + align:start position:0% +if I introduced the projection tensor P +IJ P IJ will project any spatial vector + + align:start position:0% +IJ P IJ will project any spatial vector + + + align:start position:0% +IJ P IJ will project any spatial vector +it will project out the components + + align:start position:0% +it will project out the components + + + align:start position:0% +it will project out the components +normal orthogonal to the direction of + + align:start position:0% +normal orthogonal to the direction of + + + align:start position:0% +normal orthogonal to the direction of +propagation n + + align:start position:0% + + + + align:start position:0% + +you can in fact think of pIJ as defining + + align:start position:0% +you can in fact think of pIJ as defining + + + align:start position:0% +you can in fact think of pIJ as defining +the metric for the subspace that is + + align:start position:0% +the metric for the subspace that is + + + align:start position:0% +the metric for the subspace that is +orthogonal to end so if Majan that your + + align:start position:0% +orthogonal to end so if Majan that your + + + align:start position:0% +orthogonal to end so if Majan that your +wave is propagating in the n direction + + align:start position:0% +wave is propagating in the n direction + + + align:start position:0% +wave is propagating in the n direction +there's a plane being carried along that + + align:start position:0% +there's a plane being carried along that + + + align:start position:0% +there's a plane being carried along that +it's the plane that's orthogonal to N + + align:start position:0% +it's the plane that's orthogonal to N + + + align:start position:0% +it's the plane that's orthogonal to N +and P IJ is the metric you use to define + + align:start position:0% +and P IJ is the metric you use to define + + + align:start position:0% +and P IJ is the metric you use to define +spatial distances in that in that plane + + align:start position:0% + + + + align:start position:0% + +using P IJ we can now make my H trace + + align:start position:0% +using P IJ we can now make my H trace + + + align:start position:0% +using P IJ we can now make my H trace +assuming I can make it transverse + + align:start position:0% + + + + align:start position:0% + +all I need to do I'll put one T on this + + align:start position:0% +all I need to do I'll put one T on this + + + align:start position:0% +all I need to do I'll put one T on this +to denote transverse all I need to do is + + align:start position:0% +to denote transverse all I need to do is + + + align:start position:0% +to denote transverse all I need to do is +project each of its indices you think + + align:start position:0% +project each of its indices you think + + + align:start position:0% +project each of its indices you think +that tension so we're almost there + + align:start position:0% +that tension so we're almost there + + + align:start position:0% +that tension so we're almost there +it's transverse but it's not yet trace + + align:start position:0% +it's transverse but it's not yet trace + + + align:start position:0% +it's transverse but it's not yet trace +free so if I take the trace on this guy + + align:start position:0% +free so if I take the trace on this guy + + + align:start position:0% +free so if I take the trace on this guy +okay taking the trace on this guy + + align:start position:0% +okay taking the trace on this guy + + + align:start position:0% +okay taking the trace on this guy +amounts to I am going to require that + + align:start position:0% + + + + align:start position:0% + +this be equal to zero okay now suppose I + + align:start position:0% +this be equal to zero okay now suppose I + + + align:start position:0% +this be equal to zero okay now suppose I +have some tensor that is not trace free + + align:start position:0% +have some tensor that is not trace free + + + align:start position:0% +have some tensor that is not trace free +and I want to remove its trace I'm going + + align:start position:0% +and I want to remove its trace I'm going + + + align:start position:0% +and I want to remove its trace I'm going +to make this it's a to index tensor + + align:start position:0% + + + + align:start position:0% + +so I'm not going to prove the following + + align:start position:0% +so I'm not going to prove the following + + + align:start position:0% +so I'm not going to prove the following +result it's you can easily verify for + + align:start position:0% +result it's you can easily verify for + + + align:start position:0% +result it's you can easily verify for +yourself the formula for doing so is + + align:start position:0% + + + + align:start position:0% + +that a IJ trace free it is a IJ minus 1 + + align:start position:0% +that a IJ trace free it is a IJ minus 1 + + + align:start position:0% +that a IJ trace free it is a IJ minus 1 +over n a KL g KL g IJ g is the metric + + align:start position:0% +over n a KL g KL g IJ g is the metric + + + align:start position:0% +over n a KL g KL g IJ g is the metric +that describes the manifold in which + + align:start position:0% +that describes the manifold in which + + + align:start position:0% +that describes the manifold in which +this tensor lives and is its dimension + + align:start position:0% + + + + align:start position:0% + +now for us the tensor field whose trace + + align:start position:0% +now for us the tensor field whose trace + + + align:start position:0% +now for us the tensor field whose trace +i want to remove is h IJ t + + align:start position:0% + + + + align:start position:0% + +so hij bar T is the field whose trace I + + align:start position:0% +so hij bar T is the field whose trace I + + + align:start position:0% +so hij bar T is the field whose trace I +wish to remove this lives in the two + + align:start position:0% +wish to remove this lives in the two + + + align:start position:0% +wish to remove this lives in the two +dimensional manifold whose metric is + + align:start position:0% +dimensional manifold whose metric is + + + align:start position:0% +dimensional manifold whose metric is +projection tensor pIJ and we are working + + align:start position:0% +projection tensor pIJ and we are working + + + align:start position:0% +projection tensor pIJ and we are working +in a space where raising and lowering + + align:start position:0% +in a space where raising and lowering + + + align:start position:0% +in a space where raising and lowering +indices there's really no important + + align:start position:0% +indices there's really no important + + + align:start position:0% +indices there's really no important +distinction between the two of them + + align:start position:0% +distinction between the two of them + + + align:start position:0% +distinction between the two of them +because we're working in linearized + + align:start position:0% +because we're working in linearized + + + align:start position:0% +because we're working in linearized +theory so I remove the trace by taking + + align:start position:0% +theory so I remove the trace by taking + + + align:start position:0% +theory so I remove the trace by taking +this guy and subtracting off pardon me + + align:start position:0% +this guy and subtracting off pardon me + + + align:start position:0% +this guy and subtracting off pardon me +just one moment yeah + + align:start position:0% + + + + align:start position:0% + +tracting off like so pardon me + + align:start position:0% +tracting off like so pardon me + + + align:start position:0% +tracting off like so pardon me +GWT on it plugging in my various + + align:start position:0% +GWT on it plugging in my various + + + align:start position:0% +GWT on it plugging in my various +definitions this turns into HL k PL i PK + + align:start position:0% +definitions this turns into HL k PL i PK + + + align:start position:0% +definitions this turns into HL k PL i PK +j minus 1/2 + + align:start position:0% + + + + align:start position:0% + +okay so you might want to go and check + + align:start position:0% +okay so you might want to go and check + + + align:start position:0% +okay so you might want to go and check +them outta there but this is all I'm + + align:start position:0% +them outta there but this is all I'm + + + align:start position:0% +them outta there but this is all I'm +very confident in this there's an + + align:start position:0% +very confident in this there's an + + + align:start position:0% +very confident in this there's an +overall factor of H bar LK and the last + + align:start position:0% +overall factor of H bar LK and the last + + + align:start position:0% +overall factor of H bar LK and the last +thing which I will note is that once I + + align:start position:0% +thing which I will note is that once I + + + align:start position:0% +thing which I will note is that once I +have removed the trace this bar becomes + + align:start position:0% +have removed the trace this bar becomes + + + align:start position:0% +have removed the trace this bar becomes +meaningless its trace free so the trace + + align:start position:0% +meaningless its trace free so the trace + + + align:start position:0% +meaningless its trace free so the trace +reversing of it has no action now you + + align:start position:0% +reversing of it has no action now you + + + align:start position:0% +reversing of it has no action now you +should be a little bit careful about + + align:start position:0% +should be a little bit careful about + + + align:start position:0% +should be a little bit careful about +that there's a few different notions of + + align:start position:0% +that there's a few different notions of + + + align:start position:0% +that there's a few different notions of +trace that went into this definition + + align:start position:0% +trace that went into this definition + + + align:start position:0% +trace that went into this definition +without proof and just stating that by + + align:start position:0% +without proof and just stating that by + + + align:start position:0% +without proof and just stating that by +being a little bit more careful with + + align:start position:0% +being a little bit more careful with + + + align:start position:0% +being a little bit more careful with +some of the definitions we put down the + + align:start position:0% +some of the definitions we put down the + + + align:start position:0% +some of the definitions we put down the +difference between when you when you + + align:start position:0% +difference between when you when you + + + align:start position:0% +difference between when you when you +count this up you'll find that you know + + align:start position:0% +count this up you'll find that you know + + + align:start position:0% +count this up you'll find that you know +you may be making a small error but it + + align:start position:0% +you may be making a small error but it + + + align:start position:0% +you may be making a small error but it +is on the order of terms that are + + align:start position:0% +is on the order of terms that are + + + align:start position:0% +is on the order of terms that are +quadratic in the perturbation putting + + align:start position:0% +quadratic in the perturbation putting + + + align:start position:0% +quadratic in the perturbation putting +all these pieces together we find we + + align:start position:0% +all these pieces together we find we + + + align:start position:0% +all these pieces together we find we +obtain our transverse and traceless + + align:start position:0% +obtain our transverse and traceless + + + align:start position:0% +obtain our transverse and traceless +metric perturbation which looks like + + align:start position:0% +metric perturbation which looks like + + + align:start position:0% +metric perturbation which looks like +this + + align:start position:0% + + + + align:start position:0% + +this is a result known as the quadrupole + + align:start position:0% +this is a result known as the quadrupole + + + align:start position:0% +this is a result known as the quadrupole +formula for gravitational waves this is + + align:start position:0% +formula for gravitational waves this is + + + align:start position:0% +formula for gravitational waves this is +so given just take a stock of the final + + align:start position:0% +so given just take a stock of the final + + + align:start position:0% +so given just take a stock of the final +result suppose you have some dynamic + + align:start position:0% +result suppose you have some dynamic + + + align:start position:0% +result suppose you have some dynamic +gravitating source this is telling me + + align:start position:0% +gravitating source this is telling me + + + align:start position:0% +gravitating source this is telling me +what I do is I compute the quadrupole + + align:start position:0% +what I do is I compute the quadrupole + + + align:start position:0% +what I do is I compute the quadrupole +moment associate that source I take two + + align:start position:0% +moment associate that source I take two + + + align:start position:0% +moment associate that source I take two +time derivatives I hit it with this + + align:start position:0% +time derivatives I hit it with this + + + align:start position:0% +time derivatives I hit it with this +combination of projection tensors which + + align:start position:0% +combination of projection tensors which + + + align:start position:0% +combination of projection tensors which +has to do that tells me something about + + align:start position:0% +has to do that tells me something about + + + align:start position:0% +has to do that tells me something about +the geometry of the source that's saying + + align:start position:0% +the geometry of the source that's saying + + + align:start position:0% +the geometry of the source that's saying +that my source the waves of come from + + align:start position:0% +that my source the waves of come from + + + align:start position:0% +that my source the waves of come from +the source propagating along a + + align:start position:0% +the source propagating along a + + + align:start position:0% +the source propagating along a +particular direction to me and this + + align:start position:0% +particular direction to me and this + + + align:start position:0% +particular direction to me and this +picks out the components that are + + align:start position:0% +picks out the components that are + + + align:start position:0% +picks out the components that are +transverse with respect to that + + align:start position:0% +transverse with respect to that + + + align:start position:0% +transverse with respect to that +direction and are our traceless so that + + align:start position:0% +direction and are our traceless so that + + + align:start position:0% +direction and are our traceless so that +I don't have any gauge degrees of + + align:start position:0% +I don't have any gauge degrees of + + + align:start position:0% +I don't have any gauge degrees of +freedom and what results multiply by + + align:start position:0% +freedom and what results multiply by + + + align:start position:0% +freedom and what results multiply by +twice Newton's constant divided by + + align:start position:0% +twice Newton's constant divided by + + + align:start position:0% +twice Newton's constant divided by +distance and this is the wave field that + + align:start position:0% +distance and this is the wave field that + + + align:start position:0% +distance and this is the wave field that +our friends over and building nw20 two + + align:start position:0% +our friends over and building nw20 two + + + align:start position:0% +our friends over and building nw20 two +can now measure pretty much everyday + + align:start position:0% +can now measure pretty much everyday + + + align:start position:0% +can now measure pretty much everyday +you're going to do a few homework + + align:start position:0% +you're going to do a few homework + + + align:start position:0% +you're going to do a few homework +exercises associate with this one thing + + align:start position:0% +exercises associate with this one thing + + + align:start position:0% +exercises associate with this one thing +which is worth commenting on before I + + align:start position:0% +which is worth commenting on before I + + + align:start position:0% +which is worth commenting on before I +move on is when you keep factors of C in + + align:start position:0% +move on is when you keep factors of C in + + + align:start position:0% +move on is when you keep factors of C in +this that G goes over to G over C to the + + align:start position:0% +this that G goes over to G over C to the + + + align:start position:0% +this that G goes over to G over C to the +let me double check that didn't you ever + + align:start position:0% +let me double check that didn't you ever + + + align:start position:0% +let me double check that didn't you ever +see the fourth or G over C squared + + align:start position:0% +see the fourth or G over C squared + + + align:start position:0% +see the fourth or G over C squared +anyhow it's G divided by C to some power + + align:start position:0% + + + + align:start position:0% + +let's just say that it's missing factors + + align:start position:0% +let's just say that it's missing factors + + + align:start position:0% +let's just say that it's missing factors +of C + + align:start position:0% + + + + align:start position:0% + +I'm a comment on that in some notes that + + align:start position:0% +I'm a comment on that in some notes that + + + align:start position:0% +I'm a comment on that in some notes that +I will add to the to the board and so + + align:start position:0% +I will add to the to the board and so + + + align:start position:0% +I will add to the to the board and so +that kind of tells you that this is + + align:start position:0% +that kind of tells you that this is + + + align:start position:0% +that kind of tells you that this is +going to be a really small quantity + + align:start position:0% +going to be a really small quantity + + + align:start position:0% +going to be a really small quantity +makes it very hard for these things to + + align:start position:0% +makes it very hard for these things to + + + align:start position:0% +makes it very hard for these things to +be measured nonetheless it turns out + + align:start position:0% +be measured nonetheless it turns out + + + align:start position:0% +be measured nonetheless it turns out +even though they have you think about + + align:start position:0% +even though they have you think about + + + align:start position:0% +even though they have you think about +the impact they have on a detector even + + align:start position:0% +the impact they have on a detector even + + + align:start position:0% +the impact they have on a detector even +though it's small they carry a + + align:start position:0% +though it's small they carry a + + + align:start position:0% +though it's small they carry a +tremendous amount of energy I'm gonna + + align:start position:0% +tremendous amount of energy I'm gonna + + + align:start position:0% +tremendous amount of energy I'm gonna +take a break before I begin recording + + align:start position:0% +take a break before I begin recording + + + align:start position:0% +take a break before I begin recording +mine Lex lack my next lecture but the + + align:start position:0% +mine Lex lack my next lecture but the + + + align:start position:0% +mine Lex lack my next lecture but the +next lecture is actually going to lead + + align:start position:0% +next lecture is actually going to lead + + + align:start position:0% +next lecture is actually going to lead +us to an understanding of a different + + align:start position:0% +us to an understanding of a different + + + align:start position:0% +us to an understanding of a different +version of the quadrupole formula it's + + align:start position:0% +version of the quadrupole formula it's + + + align:start position:0% +version of the quadrupole formula it's +based on this but it describes the + + align:start position:0% +based on this but it describes the + + + align:start position:0% +based on this but it describes the +energy content of gravitational waves + + align:start position:0% +energy content of gravitational waves + + + align:start position:0% +energy content of gravitational waves +both of these formulas go by the name + + align:start position:0% +both of these formulas go by the name + + + align:start position:0% +both of these formulas go by the name +the quadrupole formula a little bit + + align:start position:0% +the quadrupole formula a little bit + + + align:start position:0% +the quadrupole formula a little bit +confusing sometimes that both are used + + align:start position:0% +confusing sometimes that both are used + + + align:start position:0% +confusing sometimes that both are used +and you're gonna use both of them on up + + align:start position:0% +and you're gonna use both of them on up + + + align:start position:0% +and you're gonna use both of them on up +chemical mark assignments all right so I + + align:start position:0% +chemical mark assignments all right so I + + + align:start position:0% +chemical mark assignments all right so I +will end this recording here \ No newline at end of file diff --git a/RbJV-g9Lob8.txt b/RbJV-g9Lob8.txt new file mode 100644 index 0000000000000000000000000000000000000000..354b8d451165ec3df182cd575edf7e8fce1d04b4 --- /dev/null +++ b/RbJV-g9Lob8.txt @@ -0,0 +1,146 @@ +Our final challenge is figuring out how to +represent signed integers, for example, what + +should be our representation for the number +-2000? + +In decimal notation, the convention is to +precede the number with a "+" or "-" to indicate + +whether it's positive or negative, usually +omitting the "+" to simplify the notation + +for positive numbers. +We could adopt a similar notation -- called + +"signed magnitude" -- in binary, by allocating +a separate bit at the front of the binary + +string to indicate the sign, say "0" for positive +numbers and "1" for negative numbers. + +So the signed-magnitude representation for +-2000 would be an initial "1" to indicate + +a negative number, followed by the representation +for 2000 (as described on the previous two + +slides). +However there are some complications in using + +a signed-magnitude representation. +There are two possible binary representations + +for zero: "+0" and "-0". +This makes the encoding slightly inefficient + +but, more importantly, the circuitry for doing +addition of signed-magnitude numbers is different + +than the circuitry for doing subtraction. +Of course, we're used to that – in elementary + +school we learned one technique for addition +and another for subtraction. + +To keep the circuitry simple, most modern +digital systems use the two's complement binary + +representation for signed numbers. +In this representation, the high-order bit + +of an N-bit two's complement number has a +negative weight, as shown in the figure. + +Thus all negative numbers have a 1 in the +high-order bit and, in that sense, the high-order + +bit is serving as the "sign bit" – if it's +1, the represented number is negative. + +The most negative N-bit number has a 1-bit +in the high-order position, representing the + +value -2^(N-1). +The most positive N-bit number has a 0 in + +the negative-weight high-order bit and 1's +for all the positive-weight bits, representing + +the value 2^(N-1)-1. +This gives us the range of possible values + +– for example, in an 8-bit two's complement +representation, the most negative number is + +-2^7 = -128 and the most positive number is +2^7 – 1 = 127. + +If all N bits are 1, think of that as the +sum of the most negative number with the most + +positive number, i.e., -2^(N-1) + 2^(N-1)-1, +which equals -1. + +And, of course, if all N bits are 0, that's +the unique representation of 0. + +Let's see what happens when we add the N-bit +values for -1 and 1, keeping an N-bit answer. + +In the rightmost column, 1 plus 1 is 0, carry +the 1. + +In the second column, the carry of 1 plus +1 plus 0 is 0, carry the 1. + +And so on – the result is all zero's, the +representation for 0… perfect! + +Notice that we just used ordinary binary addition, +even when one or both of the operands are + +negative. +Two's complement is perfect for N-bit arithmetic! + +To compute B - A, we can just use addition +and compute B + (-A). + +So now we just need to figure out the two's +complement representation for –A, given + +the two's complement representation for A. +Well, we know that A + (-A) = 0 and using + +the example above, we can rewrite 0 as 1 + +(-1). + +Reorganizing terms, we see that –A equals +1 plus the quantity (-1) – A. + +As we saw above, the two's complement representation +for -1 is all 1-bits, so we can write that + +subtraction as all 1's minus the individual +bits of A: A_0, A_1, … up to A_N-1. + +If a particular bit A_i is 0, then 1-A_i = 1 +and if A_i is 1, then 1-A_i = 0. + +So in each column, the result is the bitwise +complement of A_i, which we'll write using + +the C-language bitwise complement operator +tilde. + +So we see that –A equals the bitwise complement +of A plus 1. + +Ta-dah! +To practice your skill with two's complement, + +try your hand at the following exercises. +All you need to remember is how to do binary + +addition and two's complement negation (which +is "bitwise complement and add 1"). \ No newline at end of file diff --git a/Rv1UBrGVGFk.txt b/Rv1UBrGVGFk.txt new file mode 100644 index 0000000000000000000000000000000000000000..f6270d4fc7ee34ccf6e91d94cdf703e342d57ebb --- /dev/null +++ b/Rv1UBrGVGFk.txt @@ -0,0 +1,3089 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK, let's start. + +So we were talking about +melting in two dimensions, + +and the picture that +you had was something + +like a triangular lattice, +which at zero temperature + +has particles sitting +at precise sites-- + +let's say, on this +triangular lattice-- + +but then at finite +temperature, the particles + +will to start to deform. + +And the deformations were +indicated by a vector u. + +And the idea was that this +is like an elastic material, + +as long as we're thinking +about these long wavelength + +deformations. + +u and the energy +costs can be written + +for an isotropic material +in two dimensions in terms + +of two invariants. + +And traditionally, it +is written in terms + +of the so called lame +coefficients, mu and lambda. + +Where this uij, +which is the strain, + +is obtained by taking +derivatives of the deformation, + +the iuj, and symmetrizing it. + +This symmetrization essentially +eliminates an energy + +at a cost for rotations. + +And then because of this +simple quadratic translation + +of invariant form, +we could also express + +this in terms of fullier mode. + +And I'm going to write the +fullier description slightly + +differently than last time. + +Basically, this +whole form can be + +written as u plus 2 lambda over +2 q dot u tilde of q squared. + +And the other term-- other than +previously I had written things + +in terms of q dot +u and q squared + +u squared-- we write it in terms +of q crossed with u tilde of q + +squared. + +Essentially, you can see that +this ratifies that they're + +going to have modes that +are in the direction of q, + +the longitudinal modes. + +Cost is nu plus 2 +lambda, and those + +that are transfers or orthogonal +to the direction of q, + +whose cost is just mu. + +And clearly if I were +to go into real space, + +this is kind of related +to a divergence of u. + +And the divergence +of u corresponds + +to essentially squeezing or +expanding this deformation. + +So what these measures +is essentially + +the cost of changing +the density. + +And this combination is +related to the bark modulus. + +You have that even for a liquid. + +So if you have a liquid, +you try to squeeze it. + +There will be a +bulk energy cost. + +And this term, which in the +real space is kind of related + +to kern u, you would say +is corresponding to making + +the rotations. + +So if you try to rotate +this material locally, + +then the corresponding +sheer cost of the formation + +has a cost that is indicated +by mu, the sheer modulus. + +And basically what really +makes a solid is this term. + +Because as I said, a liquid +also has the bark modulus, + +but lacks the resistance +to try to sheer it, + +which is captured by this, that +is unique and characteristic + +of a solid. + +So this is the energy cost. + +The other part of +this whole story + +is that this +structure has order. + +And we can +characterize that order + +which makes it distinct from a +liquid or gas a number of ways. + +One was to do an +x-ray scattering, + +and then you would +see the back peaks. + +And really that type of +order is translational. + +And you characterize that +by an order parameter. + +It's kind of like +a spin that you + +have in the case of a +magnet being up or down. + +In this case, this +object was e to the i g + +dot u-- the deformation that +you have that's on location r. + +And then these g's are chosen to +be the inverse lattice vectors. + +It doesn't really matter +whether I write here + +u of r or the actual position. + +Because the actual positions +starts at zero temperature, + +we devalue r 0, such that +the dot product of that g + +is a multiple of 2pi. + +And so essentially, +that's what captures this. + +Clearly, if I start with +a zero temperature picture + +and just move this +around, the phase + +of this order parameter +over here will change, + +but it will be the +same across the system. + +And so this is long +range correlation that + +is present at zero +temperature, you + +can ask what happens to +it at finite temperature. + +So we can look at the row +g at some position, row g + +star at some other position. + +And so that was related to +exponential of minus g squared + +over 2-- something +like u squared + +x, or u of x minus 0 squared. + +And what we saw +was that this thing + +had a characteristic that it +was falling off with distance + +according to some +kind of power law. + +The exponent of this power +law, when calculated, + +clearly is related +to this g squared. + +Because this is the quantity +that goes logarithmically. + +And so the answer was +g squared over 4 pi. + +Heat was dependent on these +two modes being present. + +So you have nu 2 nu plus lambda, +and then 2 nu plus lambda. + +You had a form such as this. + +Now this result was +obtained as long + +as we were treating this +field, u, as just the continuum + +field that satisfies this. + +And this result is +really different, also, + +from the expectation that +at very high temperature + +the particle in a liquid +should not know anything + +about the particle +further out in the liquid, + +as long as they're beyond +some small correlation links. + +So we expect this to +actually decay exponentially + +at high temperatures. + +And we found that +we could account + +for that by addition +of these locations, + +can cause a transition +to a high temperature + +phase in which row g, row +g star, between x and 0, + +decays exponentially. + +As opposed to this +algebraic behavior, + +indicating that these +locations-- once you + +go to sufficiently +high temperature, + +such that the entropy of +creating and rearranging + +these dislocations overcomes +the large cost of creating them + +in the first place, +then you'll have + +this absence of +translational order, + +and some kind of exponential +decay of this order parameter. + +So at this stage, you may +feel comfortable enough + +to say that addition +of these dislocation + +causes our solid to melt +and become a liquid. + +Now, I indicated, +however, that the sun also + +has an orientational role. + +What I could do is-- at +each location in the solid, + +I can ask how much has +the angle been deformed, + +and look at the bond angle. + +So maybe this +particle moved here, + +and this particle moved here. + +Somewhere else, the +particles may have + +moved in a different fashion. + +And the angle that +was originally, + +say, along the x direction, +had rotated somewhere else. + +And clearly, again, +at zero temperature, + +I can look at the correlations +of this angular order, + +and they would be the +same across the system. + +I can ask what happens when +I include these deformations + +and then the dislocations. + +So in the same way that we +defined the translational order + +parameter, I can define an +orientational order parameter. + +Let's call it sci +at some location, r, + +which is e to the i. + +Theta at that location r-- + +Except that when I look +at the triangular lattice, + +it may be that the triangles +have actually rotated + +by 60 degrees or 120 degrees. + +And I can't really tell whether +I clicked once, zero times, + +twice, et cetera. + +So because of this symmetry of +the original lattice on their + +on their theta going to +theta plus 2 pi over 6, + +I have to use something +like this that will not + +be modified if I make +this transformation, + +even at zero temperature. + +If I miscount some angle by 60 +degrees, this will become fine. + +Now I want to calculate the +correlations of this theta + +from one part of this system +to another part of the system. + +So for that, what +I need to do is + +to look at the +relationship between theta + +and the distortion field, +u, that I told you before. + +Now you can see that right +on the top right corner + +I took the distortion field, +and I took it's derivative, + +and then symmetrized +the result in pencil. + +And that symmetrization +actually removes any rotation + +that I would have. + +So in order to bring +back the notation, + +I just have to put a minus sign. + +And indeed, one can show that +the distortion or displacement + +u or r across my +system-- let's call it + +u of x-- leads to a +corresponding angular + +distortion, theta, at x, which +is minus one half-- let's + +call it z hat dotted +with curve of u. + +So if, rather than doing +the i u j plus d j u i, + +if I put a minus sign, +you can see that I + +have the structure of a curve. + +In two dimensions, +actually curve + +would be something that +would be pointing only + +along the z direction. + +And so I just make +a scale on my dot, + +without taking that +in the z direction. + +And so you can do +some distortion, + +and convince yourself +that for each distortion + +you will get an +angle that is this. + +AUDIENCE: Do we need some +kind of thermalization + +to fix the dimensions of this? + +Because that can go u has +dimensions of fields, and u-- + +PROFESSOR: I'm only talking +about two dimensions. + +And in any case, +you can see that u + +is a distortion-- +is a displacement-- + +the gradient is reduced +by the displacement, + +so this thing is +dimensionless as long as you + +have these dimensions. + +AUDIENCE: Sorry. + +PROFESSOR: Yes? + +AUDIENCE: That's a 2, right? + +Not a c? + +PROFESSOR: That's a 2. + +It's the same 2 that I have for +the definition of the strain. + +Rather than a plus, +you put a minus. + +AUDIENCE: So can +we think of these + +as two sets of Goldstone +modes, or is that not a way + +to interpret it? + +Is it like two order parameters? + +I mean, you have a think +that has u dependence, but-- + +PROFESSOR: OK, so let's look +at this picture over here. + +You do have two sets of +Goldstone modes corresponding + +to longitudinal transfers. + +You can see that this +curve is the thing + +is that I call the angle. + +So if you like, you can +put the angle over here. + +But the difference between +putting an angle here, + +and this term, is that +in terms of the angle, + +there is no q dependence. + +So it is not a ghost. + +Because the cost of making a +distortion of wave number q + +does not vanish as +q squared works. + +All right, so then I can look +at the correlation between, say, + +sci of x, sci star of zero. + +And what I will be calculating +is expectation value of e + +to the i 6. + +And then I will have +this factor of-- + +So let me write it +in this fashion. + +Theta of x minus theta of 0. + +Since u is Gaussian +distributed, theta + +in the Gaussian distributor. + +So for any Gaussian +distributed entity, + +we can write the +exponential of e + +to the something as its average +as exponential of minus 1/2 + +the average of whatever +is in the exponent. + +So I will get 36 divided by 2. + +I do have the expectation +value of delta theta squared. + +But delta theta is related +up to this factor of 1/4 + +to some expectation +value of kern u. + +So I would need to calculate +kern mu at x minus kern u + +at 0, the whole thing squared +with the Gaussian average. + +Now, this entity-- +clearly what I can do + +is to go back and +look at these things + +in terms of Fourier space, +rather than position space. + +So this becomes an integral +d 2 q 2 pi to the d. + +I will get e to the +i q dot x minus 1. + +And then I have something +like q cross u tilde of q. + +And I have to do that twice. + +When I do that twice, I find +that the different q's are + +uncorrelated. + +So I will get, rather than +two of these integrals, one + +of these integrals. + +And because the q and q prime +are said to be the same, + +the product of those two +factors will be the integral 2 + +minus 2 cosine of q dot x +term that we are used to. + +And so that's where the +x dependence appears. + +And then I need the +average of q cross mu of q. + +And that I can read off +the beta [INAUDIBLE], + +root the energy over here. + +You can see that there +is a Gaussian cost + +for q plus u of q +squared, which is simply + +1 of a lingering variance. + +So basically, this term +you'll the sum of 1 over u. + +Now the difference between +all of the calculations + +that we were doing previously, +as was asked regarding + +Goldstone modes-- if I was just +looking at u squared, which + +is what I was doing +up here, I would + +need to put another factor of +1 over q squared [INAUDIBLE]. + +And then I would have +the coulomb integral that + +would grow logarithmically. + +But here you can see that +the whole thing-- the cosine + +integrated against +the constant-- + +will average out to 0. + +So I will think you +have 2 over u times + +this integral is a constant. + +So the whole thing, +at the end of the day, + +is exponential of-- that +becomes a 9 divided by 2. + +There's a factor +of 1 over the mu, + +and then I have twice the +integral of d 2 q over 2 pi + +squared. + +Which is-- you can +convince yourself + +simply the density of the +system a number of times. + +So as opposed to the +translational order, which + +was decaying as above +our lot, then we + +include the phonon modes. + +When we include +these phonon modes, + +we find that the orientational +order decays much more weakly. + +So that was falling off as +I went further and further. + +This, as I go +further and further, + +eventually reaches a +constant that is less than 1, + +but it is something. + +Using conversely +proportional to temperature-- + +so as I go to 0 +temperature, these go to 1. + +And basically because +this order parameter, + +with respect to-- +well, this measure + +of distortion with respect +to that measure of distortion + +has an additional +factor of gradient. + +I will get an additional +factor of q squared, and then + +everything changes accordingly. + +So orientational order +is much more robust. + +This phase that we were +calling the analogue of a two + +dimensional solid had only +quasi long range order. + +The long range order was +decaying as a power law. + +Yes? + +AUDIENCE: Is n dependent +on the position, or-- + +PROFESSOR: No. + +So basically, if you were to +remember the number of points + +it should be the same as the +number of allowed fullier + +modes. + +And this goes to +an integral-- 2 q + +over 2 pi squared-- when I put +the area in two dimensions. + +So the integral over +whatever [INAUDIBLE] + +zone you have over +the fullier modes + +is the same thing as +the number of points + +that you have in the original +lattice, divided by area, + +or 1 over the size of one +of those triangles squared. + +Yes? + +AUDIENCE: Where is the x +dependent in that expression? + +PROFESSOR: OK, the x +dependence basically + +disappears because you integrate +over the cosine of q x. + +And if x is sufficiently large, +those fluctuations disappear. + +AUDIENCE: Oh, so we're really +looking at the [INAUDIBLE]. + +PROFESSOR: Yes, that's right. + +So at short distances, +there are going + +to be some oscillations +or whatever. + +But it gradually-- we are +interested in the long distance + +behavior. + +At very short +distances, I can't even + +use the continuum +description for things + +that are three or +lattice spacings apart. + +So maybe I should explicitly +say that this is usually + +called quasi long range order, +versus this dependence, which + +is two long ranges. + +So given that this is more +robust than these forum-like + +fluctuations, the +next question is, well + +does it completely disappear +when I include these locations. + +So again, this calculation, +based on Gaussian's, relies + +on just the fullier modes of +that line that I have up there. + +It does not include the +dislocations, which, in order + +to properly account, +you saw that we + +need to look at a collections +of these locations appearing + +at different positions +on the lattice. + +And they had these vectorial +nature of the fullier + +interactions among them. + +So presumably, when I +go into the base where + +these locations unbind-- +and by unbinding-- + +as I said, in the +low temperature + +picture of the +dislocations, they + +should appear very +close to each other + +because it is costly to separate +them by an amount that grows + +invariably in the separation. + +In the unbound phase, you +have essentially a gas + +of dislocations that +can be anywhere. + +So the picture here +now is that indeed this + +is a phase, that if I just +focus on the dislocations, + +there is a whole bunch of them. + +In a triangular +lattice, they could + +be pointing in any one of three +directions, plus or minus. + +And then there is certainly +an additional contribution + +to the angle that comes from the +presence of these dislocations. + +So you calculate-- if you +have a dislocation that + +has inverse b, let's say at the +origin, what kind of angular + +distortion does it cause. + +And you find that it goes +like v dot x, divided + +by the absolute value of x. + +This is for one dislocation. + +This is the theta that you +would get for that dislocation + +at location x. + +Essentially, you +can see that if I + +were to replace the u that +I have here with the u that + +was caused by dislocation, +you would get something + +like this formula. + +Because remember the u that +was caused by dislocation + +was something like the +gradient of the log potential. + +It's kind of hard to +work, but maybe I'll + +make an attempt to write it. + +So let's take a +gradient of theta. + +Gradient of theta, if +I use that formula, + +you would say, OK, I +have minus 1/2 z hat dot + +kern of something. + +And if I take a gradient of the +kern, the answer should be 0. + +But that's as long as this +u is a well defined object. + +And our task was to say +that this u, then you + +have these dislocations, +is not a well defined + +object, in the sense +that you take the kern, + +and the gradient +then you would get 0. + +So essentially, I will +transport the gradient + +all the way over here, +and the part of u + +that will survive that is +the one that is characterized + +by this dislocation feat. + +Now, you can see +that this object + +kind of looks like a +Laplacian of this distortion. + +It's two the derivatives +of this distortion field + +that had this logarithm in it. + +And when you take two +derivatives of a logarithm, + +you get the delta function. + +So if you do things +correctly, you + +will find that this answer +here becomes a sum over i + +v i delta function +of x minus xi. + +So basically, each dislocation +at location x i-- again, + +depending on its v being +in each direction-- + +gives a contribution to +the gradient of theta. + +And if I were to take the +gradient of the expression + +that I have over here, the +gradient of this object + +is also-- this is like +the field that you + +have for the +logarithmic potential-- + +will give you the data function. + +So that's where the +similarity comes. + +So the full answer +comes out to be-- + +if you have a sum +over the dislocations, + +the sum over the distortion +fields that each one of them + +is causing-- and you will +have a form such as this. + +Yes? + +AUDIENCE: Should the +denominator be squared? + +PROFESSOR: Yes, that's right. + +The potential goes +logarithmically. + +The field, which is the +gradient of the potential, + +falls off as 1 over separation. + +So since I put the +separation out there, + +I have to put the +separation squared. + +So you can see that the +singular part, the part that + +arises from dislocations-- if +I have a soup of dislocations, + +I can figure out what theta is. + +Now what I did look +for-- actually, I + +was kind of hinting at that-- if +I take the gradient of theta-- + +and I forgot to put +the factor of 1/2pi + +here-- does the 4 vertices +that had charged to pi-- + +I had the potential. + +That was 1/r. + +So for dislocations +it becomes d/2pi. + +If I take the gradient, +then the gradient translates + +to sum over pi, the i +data function of x minus x + +i-- the expression that I +have written over there. + +And if I do the +fullier transform, + +you see what I did over +here was essentially + +to look at theta +in fullier space. + +So let's do something +similar here. + +So when I do the fullier +transform of this, + +I will get pi q-- the fullier +transform of this angular feat. + +And on the right hand +side, what I would get + +is essentially the +fullier transform + +of the field of dislocations. + +So I have defined my v of q to +be sum over i into the i q dot + +position of the i +dislocation, the vector that + +characterizes the dislocation. + +And it would make +sense to also tap + +into the normalization +that gives 1 + +over the square root of area. + +If you don't do that, +then at some other point + +you have to worry about +the normalization. + +So if I just multiply +both sides by q-- + +and I think I forgot the +minus sign throughout, + +which is not that important-- +but theta tilde of q + +becomes i q dot b of +q, divided-- maybe + +I should've been calling this +b tilde-- divided by q squared. + +So this is important. + +Essentially, you take the +collection of dislocations + +in this picture +and you calculate + +what the fullier transform +is, call that the tilde of q. + +Essentially, you divide +by 1 factor of q, + +and you can get the +corresponding angle of feat. + +Now what I needed +to evaluate for here + +was the average of theta +tilde of q squared. + +And you can see that if I +write this explicitly, let's + +say, q i for be tilde i 4, +then the two of them I will + +get q beta b tilde of beta. + +And then I would +have a q to the side. + +And the average over +here becomes the average + +over all contributions +of these dislocations + +that I can put across my system. + +Now, explicitly I'm interested +in the limit where q goes to 0. + +So these things depend on q. + +What I'm interested +in is the limit + +as q goes to 0, especially +what happens to this average. + +It becomes-- multiplying two +of these things together-- + +actually, in the limit +where q goes to 0, + +what I have is the sum +over all of the b's. + +So in the limit +where q goes to 0, + +this becomes an integral or sum. + +It doesn't matter which +one of them I write. + +q has gone to 0, +so I basically need + +to look at the average of +the alpha of x, the beta of x + +[INAUDIBLE], divided by area. + +So what is there +in the numerator? + +We can see that in the +numerator, sq goes to 0. + +What I'm looking at is the sum +of all of these dislocations + +that I have in the system. + +Now the average up the +sum is 0, because in all + +of our calculations, we've been +restricting the configurations + +that we moved from. + +Because if I go +beyond that strategy, + +it's going to cost too much. + +But what I'm looking +at is not the average + +of b, which is 0, but +the average of b squared, + +which is the variance. + +So essentially I have a system +that has a large area, a. + +It is on average neutral. + +And the question is, what is +the variance of the net charge. + +And my claim is that the +variance of the net charge + +is, by central limit theorem, +proportional to the area-- + +actually, it is proportional +to the units that are + +independent from each other. + +So roughly I would expect that +in this high temperature phase, + +I have a correlation that is c. + +And within each portion of +side c, will be neutral. + +But when I go within things +that are more than c apart, + +there's no reason to +maintain the strategy. + +So overall I have something +like throwing coins, + +but at each one of +them, the average + +is 0, with probability +being up or down. + +But when I look at the +variance for the entire thing, + +the average will be +proportional to the area + +in units of these things that +are independent of each other. + +It was from the normalization +factor of 1 over area. + +And these, really, I should +write as a proportionality, + +because I don't +know precisely what + +the relationship between +these independent sides + +that correlation [INAUDIBLE]. + +But they have to be +roughly proportional. + +So what do you compute? + +You compute that +the limit as q goes + +to 0, of the average of my +theta tilde of q squared + +is a structure such as this. + +I forgot to put one +more thing here. + +I don't expect to +be any correlations + +between the x +component and the y + +component of this +answer-- the variance, + +the covariance of the +dislocations in one + +direction and the +other direction-- + +so I put the delta +function there. + +If I put this over here, +I would get the q squared + +divided by q to the 4th. + +So I will get a 1 +over4 q squared. + +And I have the c squared and +then some unknown coefficient + +up here. + +So it's interesting, +because we started + +without thinking about +dislocations, just in terms + +of the distortion field. + +And we said that this object +is related to the angle. + +And indeed, we had +this distortion, + +that energy cost of distortions +is proportional to angle + +squared. + +And that angle, therefore, +is not the Goldstone mode + +because it doesn't +go like q squared. + +Now we go to this +other phase now, + +with dislocations +all over the place, + +and we calculate the expectation +value of theta squared. + +And it looks like it +came from a theory that + +was like Goldstone modes. + +So you would say that once +I am in this phase, where + +the dislocations are unbound, +there is an effective energy + +cost for these +changes in angle that + +is proportional to the +radiant of the angle squared. + +So that means fullier space, +this would go to k a over 2, + +integral into q 2 pi squared, +q squared theta tilde of q + +squared. + +So that if you had this +theory, you would definitely + +say that the expectation value +of theta tilde of q squared + +is 1 over k a q squared. + +The variance is k +a q squared invers. + +You compare those two things +and you find that once + +the dislocations have +unbound, and there + +is a correlation lend +that essentially tells you + +how far the dislocations +are talking to each other + +and maintaining neutrality, +that there is exactly + +an effective stiffness, +like a Goldstone note, + +for angular distortions, that +is proportional to c squared. + +And hence, if I were to look +at the orientation of all + +their correlations, +I would essentially + +have something like expectation +value of theta q squared, + +which is 1 over q squared. + +If I fully transform +that, I get the log. + +And so I will get +something that falls off + +in the distance to some +other exponent, if I recall + +[INAUDIBLE]. + +If I have a true +liquid-- in a liquid, + +again, maybe in a +neighborhood of seven + +or eight particles, +neighbors, et cetera, + +they talk to each other and the +orientations are correlated. + +But then I go from +one part of the liquid + +to another part of +the liquid, there + +is no correlation +between bond angles. + +I expect these things +to decay exponentially. + +So what we've established +is that neither the phonon + +nor the dislocations +are sufficient to give + +the exponential decay that +you expect for the bond. + +So this object has +quasi long range order, + +versus what I expect to +happen in the liquid, which + +is exponential of +minus x over psi. + +So the unbinding of +dislocations gives rise + +to the new phase of matter +that has this quasi long range + +order in the orientations. + +It has no positional order. + +It's a kind of a liquid crystal +that is called a hexatic. + +Yes? + +AUDIENCE: So your correlation +where you got 1 over k q + +squared, doesn't that assume +that you're allowing the angle + +to vary in minus [INAUDIBLE] +when you do your averaging? + +What about the restriction-- + +PROFESSOR: OK, so what is the +variance of the angle here? + +There's a variance of the angle +that is controlled by this 1 + +over k a. + +So if I go back and calculate +these in real space, + +I will find that if I look at +theta at location x minus theta + +at location 0, the +answer is going to go + +like 1 over k logarithm x. + +So what it says +is that if things + +are close enough to each other-- +and this is in units of 1/a-- + +up to some factor, let's +say log 5, et cetera. + +So I don't go all +the way to infinity. + +The fluctuations in angle are +inversely set by a parameter + +that we see as I approach +right after the transition is + +very large. + +So in the same sense +that previously + +for the positional +correlations I + +had the temperature being small +and inverse temperature being + +large, limiting the size of +the translational fluctuations, + +here the same thing happens for +the bond angle fluctuations. + +Close to the transitions, +they are actually small. + +So the question +that you asked, you + +could have certainly +also asked over here. + +That is, when I'm thinking +about the distortion field, + +the distortion field is +certainly going to be limited. + +If it becomes as big as this, +then it doesn't make sense. + +So given that, +what sense or what + +justification do I have +in making these Gaussian + +integrals? + +And the answer is +that while it is true + +that it is fluctuating, as +I go to low temperature, + +the degree of fluctuations +is very small. + +So effectively +what I have is that + +I have to integrate over +some finite interval + +a function that kind +of looks like this. + +And the fact that I replaced +that with an integration + +from minus infinity to infinity +rather than from minus a + +to a just doesn't matter. + +So we know that ultimately +we should get this, + +but so far we've only got +this, so what should we do? + +Well, we say OK, we +encountered this difficulty + +before in something that looked +like an angle in the xy model-- + +that low temperature +had power-law decay, + +whereas we knew that +at high temperatures + +they would have to +have exponential decay. + +And what we said was that we +need these topological defects + +in angle. + +So what you need-- topological +defects-- or in our case, + +theta is a bond angle. + +And these topological defects +in the bond angle have a name. + +They're called disconnections. + +And very roughly they correspond +to something like this. + +Suppose this is the center +one of these discriminations, + +and then maybe +next to this, here + +I have locally at the distance +r-- if I look at a point, + +I would see that the bonds +that connect it to its neighbor + +have an orientation such as the +one that I have indicated over + +here. + +Now what I want to do is, as I +go around and make a circuit, + +that this angle theta +that I have here to be 0, + +rotates and comes +back up to 60 degrees. + +So essentially what I +do is I take this line + +and I gradually shift it +around so that by the time + +I come back, I have +rotated by 60 degrees. + +It's kind of hard +for me to draw that, + +but you can imagine +what I have to do. + +So what I need to do +is to have the integral + +over a circuit that encloses +this discrimination such + +that when I do a d s dotted +with the gradient of the bond + +orientational angle, +I come back to pi over + +6 times some integer. + +And again, I expect the +[INAUDIBLE] dislocations that + +correspond to minus plus 1. + +Then the cost of +these is obtained + +by taking this distortion +fee, gradient of theta, + +whose magnitude at a distance r +from the center of this object + +is going to be 1 over 2 +pi r times pi over 6 times + +whatever this integer n is. + +And then if I substitute +this 1 over r behavior + +in this expression, which +is the effective energy + +of this entity, I will +get the logarithmic cost + +for making a single +disclination. + +Which means that +at low temperature, + +I have to create +disclination pairs. + +And then there will be +an effective interaction + +between disclination +pairs, that is + +[INAUDIBLE] in exactly the +same way that we calculated + +for the x y model. + +So up to just this minor change +that the charge of a refect + +is reduced by a factor +of six, this theory + +is identical the theory of +the unbinding of the x y + +model [INAUDIBLE] defects. + +Yes? + +AUDIENCE: Why is it pi +over 6 and not 2 pi over 6? + +PROFESSOR: You are right. + +It should be 2 pi over 6. + +Thank you. + +Yes? + +AUDIENCE: So when +you were saying that + +the-- so the distance of this +hexatic phase would require + +the dislocations to occur +to [INAUDIBLE] [INAUDIBLE] + +orientational defects. + +Is there an analogous +case where-- + +I guess you can't have +dislocations in the orientation + +without the dislocation-- + +PROFESSOR: So if you try +to make these objects + +in the original case, in +the origin of lattice, + +you will find that their +cost grows actually + +like l squared log l, as +opposed to dislocations, + +whose cost only grows as log l. + +So these entities are +extremely unlikely to occur + +in the original system. + +If you sort of go back +and ask what they actually + +correspond to, if you have a +picture that you have generated + +on the computer, +they're actually + +reasonably easy to identify. + +Because the centers +of these disclinations + +correspond to +having points, that + +have, rather than 6 +neighbors, 5 or 7 neighbors. + +So you generate the picture, +and you find mostly you have + +neighborhoods with 6 neighbors, +and then there's a site where + +there's 5 neighbours, +and another site that's 7 + +neighbors. + +5 and 7 come more +or less in pairs, + +and you can identify these +disclination pairs reasonably + +easy. + +So at the end of the day, +the picture that we have + +is something like this. + +We are starting with +the triangular lattice + +that I drew at the +beginning, and you're + +increasing temperature. + +We're asking what happens. + +So this is 0 temperature. + +Close to 0 temperature, +what we have + +is an entity that has +translational quasi + +long range order. + +So this quantity goes like 1 +over x to this power a to g. + +Whereas the orientations +go to a constant. + +Now, this a to g is +there because there's + +a shear modulus. + +And so throughout this phase, +I have a shear modulus. + +The parameter that +I'm calling u, + +I had scaled inversely +with temperature. + +So I have this +shear modulus u that + +diverges once we scale +by temperature as 1 + +over temperature. + +But then as I come down, the +reduction is more than one + +over temperature +because I will have + +this effect of dislocations +appearing in pairs, + +and the system becomes softer. + +And eventually you +will find that there's + +a transition temperature at +which the shear modulus drops + +down to 0. + +And we said that +near this transition, + +there is this behavior +that mu approaches mu + +c, whatever it is, +with something-- let's + +call this t 1. + +T 1 minus t to this +exponent mu bar + +which was planned to be 6963. + +Now, once we are beyond +this temperature t 1, then + +our positional correlations +decay exponentially + +at some correlation, like c. + +And this c is +something that diverges + +on approaching this transition. + +So basically I have a c that +goes up here to infinity. + +And the fact that if +we calculate the c, + +it diverges according to +this strange formula that + +was 1 over t minus t +1 to this exponent mu + +bar Very strange +type of divergence. + +But then, associated with +the presence of this c + +is the fact that when you +look at the orientational + +correlations, they don't +decay as an exponential + +but as a power-law 8 of c. + +And this 8 of c is related to +this k a, and falls off as 1 + +over c squared. + +So here it diverges as you +approach this transition. + +Now, as we go further +and further on, + +the disclinations will +appear-- disclinations + +with [INAUDIBLE] +resolve of the angles + +to be parallel to each other. + +And there's another +transition that + +is [INAUDIBLE], at which this is +going to suddenly go down to 0. + +And close to here, +we have that a to c + +reaches the critical +value of 1/4 v + +to square root +of-- let's call it + +t 2-- v the square +root singularity. + +And then finally we have +the ordinary liquid phase, + +where additionally I will find +that psi 6 of x psi star 6 of 0 + +decays exponentially. + +Let's call it psi 6. + +And this psi 6 is +something that will diverge + +of this transition as an +exponential of minus 1 + +over square root of t minus t2. + +So this is the current +scenario of how + +melting could occur for a system +of particles in two dimensions. + +If it is a continuous +phase transition, + +it has to go through +these two transitions + +with the intermediate +exotic phase. + +Of course, it is also +possible-- and typically people + +were seeing numerically +when they were doing hearts, + +spheres, et cetera, +that there is + +a direct transition from here +to here, which is discontinuous, + +like you have in +three dimensions. + +So that's an area of a +discontinuous transition + +that is not ruled out. + +But if you have +continuous transitions, + +it has to have this intermediate +phase in [INAUDIBLE]. + +Any questions? + +Yes? + +AUDIENCE: [INAUDIBLE] +so the red one is mu. + +The yellow one is theta psi, and +the purple one is [INAUDIBLE]. + +PROFESSOR: The correlation, +then, that I would put here. + +So they are three +different entities. + +So throughout the +course, we have + +been thinking about +systems that are + +described by some kind of +an equilibrium probability + +distribution. + +So what we did not +discuss is how the system + +comes to that equilibrium. + +So we're going to now very +briefly talk about dynamics, + +and the specific +type of dynamics + +that is common to +condensed matter + +systems at finite +temperature, which I + +will call precipative dynamics. + +And the prototype of this +is a Brownian particle + +that I will briefly +review for you. + +So what you have is that +you have a particle that + +is within some +kind of a solvent, + +and this particle +is moving around. + +So you would say, +let's for simplicity + +actually focus on +the one direction, x. + +And you would say that +the mass of the particle + +times its acceleration +is equal to the forces + +that it's experiencing. + +The forces-- well, if you +are moving in a fluid, + +you are going to be +subject to some kind + +of a dissipative force +which is typically + +portional to your velocity. + +If you, for example, +solve for the hydrodynamic + +of a sphere in a +fluid, you find that mu + +is related to +viscosity inversely + +to the size of the +particle, et cetera. + +But that behavior is generic. + +You're not going be +thinking about that. + +Now suppose that +additionally I put + +some kind of an optical +trap, or something that tries + +to localize this potential. + +So then there would be +an additional force v + +2, the derivative of the +potential with respect to x. + +And then we are talking +about Brownian particles. + +Brownian particles are +constantly jiggling. + +So there is also a random force +that is a function of time. + +Now we are going to be +interested in the dynamics that + +is very much controlled +by the dissipation term. + +And acceleration we can forget. + +And if we are in that limit, +we can write the equation + +as mu-- I can sort of rearrange +it slightly as-- actually, + +let me change location to this. + +So that the eventual +velocity x dot + +is going to be proportional +to the external force. + +mu the coefficient +that is the mobility. + +So mu essentially relates +the force to the velocity. + +Of course, this is +the average force. + +And there is a fluctuating +part, so essentially, I + +call mu times this to be +the a times function of t. + +Now, if I didn't have +this external force, + +the fluctuations of the +particles would be diffusive. + +And you can convince +yourself that you + +can get the diffusive result +provided that you relate + +the correlations of this +force that fluctuating + +and have 0 average, the +diffusion constant d + +of the particle in the medium +through delta of t minus t. + +So if their track was not there, +you solve of this equation + +without the track and find that +the prohibitive distribution + +for x grows as a Gaussian whose +width grows with time, as d t. + +d therefore must be +the diffusion constant. + +Now, in the presence +of the potential, + +this particle will +start to fluctuate. + +Eventually if you +wait long enough, + +there is a probability +that it will be here, + +a probability to +be somewhere else. + +So at long enough times, +there's a probability p + +of x to find the particle. + +And you expect +that t of x will be + +proportional to exponential +of minus v of x divided + +by whatever the temperature is. + +And you can show that in +order to have this occur, + +you need to relate mu and d +through the so called Einstein + +relation. + +So this is a brief review +of Brownian particles. + +Yes? + +AUDIENCE: The average and +time correlation of eta + +can be found by saying +the potential is 0, right? + +PROFESSOR: Mm hmm. + +AUDIENCE: Those +will still be true + +even if the potential +is not 0, right? + +PROFESSOR: Yes. + +So I just wanted to have an +idea of where this d comes from. + +But more specifically, this +is the important thing. + +That if at very +long times you want + +to have a probability +distribution coming + +from this equation, that +has the Boltzmann form + +with k t, the coefficients +of mu and the noise, + +you have to relate through the +so called Einstein relation. + +And once you do +that, this result + +is true no matter how +complicated this v of x is. + +So in general, for a +complicated v of x, + +you won't be able to solve +this equation analytically. + +You can only do it numerically. + +Yet you are guaranteed that +this equation with this noise + +correlator will have +asymptotically a probability + +distribution of [INAUDIBLE]. + +The problem that we +have been looking at all + +along is something different. + +Let's say you have, let's +say, a piece of magnet + +or some other system +that we characterize, + +let's say, by something m of x. + +Again, you can do it for vector, +but for simplicity, let's do it + +for the scalar case. + +So we know, or we have stated, +that subject to the symmetries + +of the system, I +know the probability. + +For some configuration of this +field is governed by a form, + +let's say, that has +Landau Ginzburg character. + +So that has been +our starting point. + +We have said that I have a +prohibitive distribution that + +is of this form. + +So that statement is kind +of like this statement. + +But the way that I +came to that statement + +was to say that there +was a degree of freedom + +x, the position of the particle, +that was fluctuating subject + +to forces and external +variables from the particles + +of the fluid, that was given +by this so called Langevin + +equation. + +So I had a time +dependent prescription + +that eventually went to the +Boltzmann way that I wanted. + +Here I have started with +the final Boltzmann weight. + +And the question is, can +I think about a dynamics + +for a field that will +eventually give this state. + +So there are lots and +lots of different dynamics + +that I can impose. + +But I want to look +at the dynamics that + +is closest to the Brownian +particle that I wrote, + +and that's where this +word dissipative comes. + +So among the universe of +all possible dynamics, + +I'm going to look at one +that has a linear time + +derivative for the field n. + +So this is the +analog of the x dot. + +And so I write that it is +equal to some coefficient, + +that with their minds, +the ease with which + +that particle-- well the +field of that location x + +changes as a function of the +forces that is exerted on it. + +I assume that mu is the +same across my system. + +So here I'm already assuming +there's no x dependence. + +This system is uniform. + +And then there was a d v by d x. + +So v was ultimately the +thing that was appearing + +in the Boltzmann weight. + +So clearly the analog +of the v that I have + +is this Landau Ginzburg. + +So I will do a function of the +derivative of this quantity + +that I will call beta h, +with respect to m of x. + +Again, over there, I +had one variable, x. + +You can imagine that I could +have had a system where + +two particles, x 1 and x 2, also +have an interaction among them. + +Then the equation that I +would have had over there + +would be the force that +is acting on particle 1, + +by taking the total +potential-- which + +is the external potential +plus the potential that + +comes from the inter +particle interaction. + +So I would have to +take a derivative + +of the net potential energy +v, divided with respect + +to either x 1 or x 2 +to calculate the force + +on the first one +or the second one. + +So here for a +particular configuration + +m of the field +across the system, + +if I'm interested in the +dynamics of this position x, + +I have to take this total +internal potential energy, + +and take the +derivative with respect + +to the variable that is +sitting on that side. + +So that's why this +is a functional + +derivative of this end. + +And then I will have +to put a noise, eta. + +Well, again, if I had +multiple particles, + +I would subject each one of +them to an independent noise. + +So at each location, I +have an independent noise. + +So the noise is a +function of time, + +but it is also wearing +across my system. + +So if I take that form and do +the functional derivative-- + +so if I take the derivative +with respect to m of x, + +I have to take the +derivative of these objects. + +So I will have minus derivative +of t m squared is t m. + +The u m to the 4th is +4 u m q, and so forth. + +Once I have gotten +rid of these terms, + +then I would have terms +that depend on the gradient. + +So I would have minus the +derivative of this object + +with respect to the gradient. + +So here I would get +k gradient of m. + +And then the next term would +be Laplacian derivative, + +with respect to Laplacian. + +So I would put l Laplacian +of m, and so forth + +with the methodologies of +taking function derivatives. + +And then I have the noise. + +So this leads to +an equation which + +is called a time +dependent, Landau Ginzberg. + +Because we started with +the Landau Ginzberg weight, + +and this equation, +as we see shortly, + +subject to similar restrictions +as we had before, will give us, + +eventually, this +probability distribution. + +This is a difficult +equation in the same sense + +that the original +Landau Ginzberg + +is difficult to look at +correlations, et cetera. + +This is a nonlinear equation, +causes various difficulties, + +and we need approaches +to be able to deal + +with the difficult, +non linealities. + +So what we did for +the Landau Ginzburg + +was to initially get insights +and simplify the system + +by focusing on the linearized +or Gaussian version. + +So let's look at the version +of this equation that + +is linearized. + +And when it is linearized, what +I have on the left hand side + +is d m by d t. + +What I have on the +right hand side is mu. + +I have t m. + +I got rid of the +non linear term, + +so the next term that I will +have will be k Laplacian of m, + +and then will be minus l 4th +derivative of m, and so forth. + +And then there will be +a noise [INAUDIBLE]. + +One thing that I +can immediately do + +is to go to fullier transform. + +So m of x goes to m theta of q. + +And if I do that, but not +fullier transform in time, + +I will get that the time +derivative of m tilde of q + +is essentially what I have here. + +And I forgot the minus +that I have here. + +So this minus is important. + +And then this becomes negative, +this becomes positive. + +So that when I go fullier +transform, what I will get + +is minus t plus k q squared plus +l q to the 4th, and so forth. + +And tilde of q with +this mu out front. + +And then the fullier +transform of what my noise is. + +First thing to note is that +even in the absence of noise, + +there is a set of +relaxation times. + +That is, for eta it was to 0. + +Or in general, I would +have n tilde of q and p. + +I can solve this +equation kind of simply. + +It is the m by d t is +some constant times + +n-- let's call it +gama of q-- which + +has dimensions of 1 over time. + +So I can call that +1 over tau of q. + +If I didn't have +noise, if I started + +with some original +value at time 0, + +it is going to +decay exponentially + +with this characteristic time. + +And once I have +noise, it is actually + +easy to convince yourself +that the answer is + +0 2 t d t prime e to the minus +this gamma of q or inversify. + +Tau of q times eta +of q i t prime. + +So you see that you have a +hierarchy of relaxation times, + +ta of q, which are 1 over u t +plus k q squared, and so forth, + +which scale in two limits. + +Either the wavelength lambda, +which is the inverse of q + +is much larger than the +correlation length-- + +and the correlation +length of this model + +you have seen to be the +square root of t over k, + +square root of k over +t-- or the other limit, + +where lambda is +much less than c. + +In this limit, +where we are looking + +at modes that are much shorter +than the correlation length, + +this term is dominant. + +This becomes 1 over +mu k q squared. + +In the other limit, it goes +to a constant 1 over u t. + +So this linear equation +has a whole bunch + +of modes that can +be characterized + +by their wavelength +or their wave number. + +You find that the +short wavelength modes + +have this characteristic, time, +that becomes longer and longer + +as the wavelength increases. + +So if you make the +wavelength twice as large, + +and you want to relax a +system that is linearly + +twice as large, this says that +it will take 4 times longer. + +Because the answer goes +like lambda squared. + +Whereas eventually you reach the +size of the correlation length. + +Once you are beyond the size +of the correlation length, + +it doesn't matter. + +It's the same time. + +But the interesting +thing, of course, to us + +is that there are +phase transitions that + +are continuous. + +And close to that +phase transition, + +the correlation length +goes to infinity. + +Which means that the relaxation +time also will go to infinity. + +So according to +this theory, there's + +a particular divergence +as 1 over t minus t c. + +But it will be modified, and +as I will discuss next time, + +this is only-- even within +to dissipative class-- + +one type of dynamics +that you can have. + +And there are +additional dynamics, + +and this system +characterizes criticality + +as single universality +class in statics. + +There are many dynamic +universality classes that + +correspond to this same static. \ No newline at end of file diff --git a/S6dw885-SZI.txt b/S6dw885-SZI.txt new file mode 100644 index 0000000000000000000000000000000000000000..b8b4d9bd99fbb3ed929517bd422e509e7ea1dd99 --- /dev/null +++ b/S6dw885-SZI.txt @@ -0,0 +1,8616 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu well okay this is my lecture + + align:start position:0% +ocw.mit.edu well okay this is my lecture + + + align:start position:0% +ocw.mit.edu well okay this is my lecture +on uh section 6.1 of the + + align:start position:0% +on uh section 6.1 of the + + + align:start position:0% +on uh section 6.1 of the +notes + + align:start position:0% +notes + + + align:start position:0% +notes +uh really the central problem of uh + + align:start position:0% +uh really the central problem of uh + + + align:start position:0% +uh really the central problem of uh +numerical linear algebra is solving ax + + align:start position:0% +numerical linear algebra is solving ax + + + align:start position:0% +numerical linear algebra is solving ax +equal B by elimination that's what is + + align:start position:0% +equal B by elimination that's what is + + + align:start position:0% +equal B by elimination that's what is +used much more often than anything else + + align:start position:0% +used much more often than anything else + + + align:start position:0% +used much more often than anything else +but we're talking about sparse matrices + + align:start position:0% +but we're talking about sparse matrices + + + align:start position:0% +but we're talking about sparse matrices +large sparse matrices that's what we're + + align:start position:0% +large sparse matrices that's what we're + + + align:start position:0% +large sparse matrices that's what we're +we have in mind from from for a long + + align:start position:0% +we have in mind from from for a long + + + align:start position:0% +we have in mind from from for a long +time now they're probably the all + + align:start position:0% +time now they're probably the all + + + align:start position:0% +time now they're probably the all +lectures coming up thinking of those + + align:start position:0% +lectures coming up thinking of those + + + align:start position:0% +lectures coming up thinking of those +matrices and this is the Prototype of a + + align:start position:0% +matrices and this is the Prototype of a + + + align:start position:0% +matrices and this is the Prototype of a +large sparse Matrix okay so the main + + align:start position:0% +large sparse Matrix okay so the main + + + align:start position:0% +large sparse Matrix okay so the main +point the lecture is if you take the + + align:start position:0% +point the lecture is if you take the + + + align:start position:0% +point the lecture is if you take the +unknowns in whatever order they're given + + align:start position:0% +unknowns in whatever order they're given + + + align:start position:0% +unknowns in whatever order they're given +here I took them uh numbering along the + + align:start position:0% +here I took them uh numbering along the + + + align:start position:0% +here I took them uh numbering along the +rows 1 2 3 4 5 6 seven eight and so on + + align:start position:0% +rows 1 2 3 4 5 6 seven eight and so on + + + align:start position:0% +rows 1 2 3 4 5 6 seven eight and so on +that's uh you you got to stop and think + + align:start position:0% +that's uh you you got to stop and think + + + align:start position:0% +that's uh you you got to stop and think +or get the computer to look at + + align:start position:0% +or get the computer to look at + + + align:start position:0% +or get the computer to look at +reorderings because the reorderings can + + align:start position:0% +reorderings because the reorderings can + + + align:start position:0% +reorderings because the reorderings can +make an enormous difference in the in + + align:start position:0% +make an enormous difference in the in + + + align:start position:0% +make an enormous difference in the in +the in the fill in so this is the + + align:start position:0% +the in the fill in so this is the + + + align:start position:0% +the in the fill in so this is the +actually the key word for this lecture + + align:start position:0% +actually the key word for this lecture + + + align:start position:0% +actually the key word for this lecture +is and the key concept is the fact that + + align:start position:0% +is and the key concept is the fact that + + + align:start position:0% +is and the key concept is the fact that +as elimination goes forward all a lot of + + align:start position:0% +as elimination goes forward all a lot of + + + align:start position:0% +as elimination goes forward all a lot of +these + + align:start position:0% + + + + align:start position:0% + +zeros become + + align:start position:0% +zeros become + + + align:start position:0% +zeros become +nonzeros so let let me see it happen + + align:start position:0% +nonzeros so let let me see it happen + + + align:start position:0% +nonzeros so let let me see it happen +first of all so this is the whole idea + + align:start position:0% +first of all so this is the whole idea + + + align:start position:0% +first of all so this is the whole idea +of fill in what's going to be the very + + align:start position:0% +of fill in what's going to be the very + + + align:start position:0% +of fill in what's going to be the very +first entries that are filled in + + align:start position:0% +first entries that are filled in + + + align:start position:0% +first entries that are filled in +well uh let's see I guess that the very + + align:start position:0% +well uh let's see I guess that the very + + + align:start position:0% +well uh let's see I guess that the very +first row operation if if you took the m + + align:start position:0% +first row operation if if you took the m + + + align:start position:0% +first row operation if if you took the m +tricks like this and did did elimination + + align:start position:0% +tricks like this and did did elimination + + + align:start position:0% +tricks like this and did did elimination +four is the first pivot you would add + + align:start position:0% +four is the first pivot you would add + + + align:start position:0% +four is the first pivot you would add +1/4 of the first row to the second row + + align:start position:0% +1/4 of the first row to the second row + + + align:start position:0% +1/4 of the first row to the second row +to make that a zero right and then what + + align:start position:0% +to make that a zero right and then what + + + align:start position:0% +to make that a zero right and then what +would happen this would change that + + align:start position:0% +would happen this would change that + + + align:start position:0% +would happen this would change that +number that's + + align:start position:0% +number that's + + + align:start position:0% +number that's +okay but this would put a new number in + + align:start position:0% +okay but this would put a new number in + + + align:start position:0% +okay but this would put a new number in +there right so a new number would appear + + align:start position:0% +there right so a new number would appear + + + align:start position:0% +there right so a new number would appear +when we do that first row operation and + + align:start position:0% +when we do that first row operation and + + + align:start position:0% +when we do that first row operation and +then all Al working with this pivot I + + align:start position:0% +then all Al working with this pivot I + + + align:start position:0% +then all Al working with this pivot I +would operate on that row to make this a + + align:start position:0% +would operate on that row to make this a + + + align:start position:0% +would operate on that row to make this a +zero and then this would change that + + align:start position:0% +zero and then this would change that + + + align:start position:0% +zero and then this would change that +would fill in right and I guess that + + align:start position:0% +would fill in right and I guess that + + + align:start position:0% +would fill in right and I guess that +this already has something so that won't + + align:start position:0% +this already has something so that won't + + + align:start position:0% +this already has something so that won't +be new so each of those steps each of + + align:start position:0% +be new so each of those steps each of + + + align:start position:0% +be new so each of those steps each of +those row + + align:start position:0% +those row + + + align:start position:0% +those row +operations filled in a + + align:start position:0% +operations filled in a + + + align:start position:0% +operations filled in a +nonzero + + align:start position:0% +nonzero + + + align:start position:0% +nonzero +and reduce the the sparsity of the + + align:start position:0% +and reduce the the sparsity of the + + + align:start position:0% +and reduce the the sparsity of the +Matrix and the the sparsity is what + + align:start position:0% +Matrix and the the sparsity is what + + + align:start position:0% +Matrix and the the sparsity is what +we're living by so we want to know and + + align:start position:0% +we're living by so we want to know and + + + align:start position:0% +we're living by so we want to know and +and now if I continue and + + align:start position:0% +and now if I continue and + + + align:start position:0% +and now if I continue and +continue uh we'd actually we'd need + + align:start position:0% +continue uh we'd actually we'd need + + + align:start position:0% +continue uh we'd actually we'd need +matlb to use spy in mat lab to uh see + + align:start position:0% +matlb to use spy in mat lab to uh see + + + align:start position:0% +matlb to use spy in mat lab to uh see +what the picture would look like it's + + align:start position:0% +what the picture would look like it's + + + align:start position:0% +what the picture would look like it's +very interesting to see it Spy shows you + + align:start position:0% +very interesting to see it Spy shows you + + + align:start position:0% +very interesting to see it Spy shows you +the nonzeros we're we're we're very much + + align:start position:0% +the nonzeros we're we're we're very much + + + align:start position:0% +the nonzeros we're we're we're very much +focused on what's zero and what isn't + + align:start position:0% +focused on what's zero and what isn't + + + align:start position:0% +focused on what's zero and what isn't +zero in Matrix entry + + align:start position:0% +zero in Matrix entry + + + align:start position:0% +zero in Matrix entry +we we actually keep track of that the + + align:start position:0% +we we actually keep track of that the + + + align:start position:0% +we we actually keep track of that the +the the structure of the Matrix as well + + align:start position:0% +the the structure of the Matrix as well + + + align:start position:0% +the the structure of the Matrix as well +of course as separately keeping track of + + align:start position:0% +of course as separately keeping track of + + + align:start position:0% +of course as separately keeping track of +the actual numbers so one place we're + + align:start position:0% +the actual numbers so one place we're + + + align:start position:0% +the actual numbers so one place we're +keeping the actual numbers but in the + + align:start position:0% +keeping the actual numbers but in the + + + align:start position:0% +keeping the actual numbers but in the +decisions on ordering we're only + + align:start position:0% +decisions on ordering we're only + + + align:start position:0% +decisions on ordering we're only +interested in zeros and nonzeros so let + + align:start position:0% +interested in zeros and nonzeros so let + + + align:start position:0% +interested in zeros and nonzeros so let +me look even more at this fill in just + + align:start position:0% +me look even more at this fill in just + + + align:start position:0% +me look even more at this fill in just +now you saw it happen up there let me + + align:start position:0% +now you saw it happen up there let me + + + align:start position:0% +now you saw it happen up there let me +just look at a single fill-in step + + align:start position:0% +just look at a single fill-in step + + + align:start position:0% +just look at a single fill-in step +so I have a so I have a row J and a row + + align:start position:0% + + + + align:start position:0% + +I and this is going to be the pivot that + + align:start position:0% +I and this is going to be the pivot that + + + align:start position:0% +I and this is going to be the pivot that +I'll use to eliminate this but in this + + align:start position:0% +I'll use to eliminate this but in this + + + align:start position:0% +I'll use to eliminate this but in this +row there's + + align:start position:0% +row there's + + + align:start position:0% +row there's +a another nonzero and in this Row the + + align:start position:0% +a another nonzero and in this Row the + + + align:start position:0% +a another nonzero and in this Row the +case entry is not nonzero it's zero so + + align:start position:0% +case entry is not nonzero it's zero so + + + align:start position:0% +case entry is not nonzero it's zero so +this is what we start with prior to + + align:start position:0% +this is what we start with prior to + + + align:start position:0% +this is what we start with prior to +elimination just as we did there I just + + align:start position:0% +elimination just as we did there I just + + + align:start position:0% +elimination just as we did there I just +want to see focus on the small on the + + align:start position:0% +want to see focus on the small on the + + + align:start position:0% +want to see focus on the small on the +the fill in uh occurring okay so what + + align:start position:0% +the fill in uh occurring okay so what + + + align:start position:0% +the fill in uh occurring okay so what +does of course these are this isn't on + + align:start position:0% +does of course these are this isn't on + + + align:start position:0% +does of course these are this isn't on +the diagonal this is in column this is + + align:start position:0% +the diagonal this is in column this is + + + align:start position:0% +the diagonal this is in column this is +in um uh column K which is somewhere far + + align:start position:0% +in um uh column K which is somewhere far + + + align:start position:0% +in um uh column K which is somewhere far +out in that case somewhere close by in + + align:start position:0% +out in that case somewhere close by in + + + align:start position:0% +out in that case somewhere close by in +that + + align:start position:0% +that + + + align:start position:0% +that +case uh but we're just we're seeing + + align:start position:0% +case uh but we're just we're seeing + + + align:start position:0% +case uh but we're just we're seeing +this is on the diagonal that's the pivot + + align:start position:0% +this is on the diagonal that's the pivot + + + align:start position:0% +this is on the diagonal that's the pivot +the Jace pivot that I'm ready to use so + + align:start position:0% +the Jace pivot that I'm ready to use so + + + align:start position:0% +the Jace pivot that I'm ready to use so +I subtract a multiple of that to remove + + align:start position:0% +I subtract a multiple of that to remove + + + align:start position:0% +I subtract a multiple of that to remove +that so what does elimination will not + + align:start position:0% +that so what does elimination will not + + + align:start position:0% +that so what does elimination will not +change the pivot + + align:start position:0% + + + + align:start position:0% + +row and it will produce a zero there + + align:start position:0% +row and it will produce a zero there + + + align:start position:0% +row and it will produce a zero there +that's the point but then the real point + + align:start position:0% +that's the point but then the real point + + + align:start position:0% +that's the point but then the real point +that I'm making is that when I multiply + + align:start position:0% +that I'm making is that when I multiply + + + align:start position:0% +that I'm making is that when I multiply +this by the right number to produce a + + align:start position:0% +this by the right number to produce a + + + align:start position:0% +this by the right number to produce a +zero and do the subtraction this zero + + align:start position:0% +zero and do the subtraction this zero + + + align:start position:0% +zero and do the subtraction this zero +disappears that fills in + + align:start position:0% +disappears that fills in + + + align:start position:0% +disappears that fills in +that's that's some a i k new new the the + + align:start position:0% +that's that's some a i k new new the the + + + align:start position:0% +that's that's some a i k new new the the +the new value in row I column K is not + + align:start position:0% +the new value in row I column K is not + + + align:start position:0% +the new value in row I column K is not +zero okay so we see + + align:start position:0% +zero okay so we see + + + align:start position:0% +zero okay so we see +that as we saw for numbers here we're + + align:start position:0% +that as we saw for numbers here we're + + + align:start position:0% +that as we saw for numbers here we're +see seeing it symbolically let me see it + + align:start position:0% +see seeing it symbolically let me see it + + + align:start position:0% +see seeing it symbolically let me see it +graphically because everybody sort of to + + align:start position:0% +graphically because everybody sort of to + + + align:start position:0% +graphically because everybody sort of to +visualize the big + + align:start position:0% +visualize the big + + + align:start position:0% +visualize the big +picture I think everybody finds the + + align:start position:0% +picture I think everybody finds the + + + align:start position:0% +picture I think everybody finds the +graph description + + align:start position:0% +graph description + + + align:start position:0% +graph description +of the nonzero structure the simplest to + + align:start position:0% +of the nonzero structure the simplest to + + + align:start position:0% +of the nonzero structure the simplest to +to imagine so the graph for this little + + align:start position:0% +to imagine so the graph for this little + + + align:start position:0% +to imagine so the graph for this little +problem would be so what's the graph + + align:start position:0% +problem would be so what's the graph + + + align:start position:0% +problem would be so what's the graph +that tells me where the nonzeros are + + align:start position:0% +that tells me where the nonzeros are + + + align:start position:0% +that tells me where the nonzeros are +again it doesn't tell me what numbers + + align:start position:0% +again it doesn't tell me what numbers + + + align:start position:0% +again it doesn't tell me what numbers +they are just tells me where they are + + align:start position:0% +they are just tells me where they are + + + align:start position:0% +they are just tells me where they are +which positions it's only the positions + + align:start position:0% +which positions it's only the positions + + + align:start position:0% +which positions it's only the positions +that I worry about in deciding on the + + align:start position:0% +that I worry about in deciding on the + + + align:start position:0% +that I worry about in deciding on the +ordering to use then I execute using the + + align:start position:0% +ordering to use then I execute using the + + + align:start position:0% +ordering to use then I execute using the +actual numbers but in deciding on the + + align:start position:0% +actual numbers but in deciding on the + + + align:start position:0% +actual numbers but in deciding on the +ordering it's just the positions okay so + + align:start position:0% +ordering it's just the positions okay so + + + align:start position:0% +ordering it's just the positions okay so +I think of my graph was having node a + + align:start position:0% +I think of my graph was having node a + + + align:start position:0% +I think of my graph was having node a +node for + + align:start position:0% +node for + + + align:start position:0% +node for +every uh row so that's node J for row J + + align:start position:0% +every uh row so that's node J for row J + + + align:start position:0% +every uh row so that's node J for row J +this is node I for row row I and + + align:start position:0% +this is node I for row row I and + + + align:start position:0% +this is node I for row row I and +somewhere we'll have uh a node + + align:start position:0% +somewhere we'll have uh a node + + + align:start position:0% +somewhere we'll have uh a node +K okay so at the start and now that so + + align:start position:0% +K okay so at the start and now that so + + + align:start position:0% +K okay so at the start and now that so +those are the nodes what are the edges + + align:start position:0% +those are the nodes what are the edges + + + align:start position:0% +those are the nodes what are the edges +well this there is a non so the edges + + align:start position:0% +well this there is a non so the edges + + + align:start position:0% +well this there is a non so the edges +come from the nonzeros in The Matrix so + + align:start position:0% +come from the nonzeros in The Matrix so + + + align:start position:0% +come from the nonzeros in The Matrix so +there's a there's an edge from J to K + + align:start position:0% +there's a there's an edge from J to K + + + align:start position:0% +there's a there's an edge from J to K +because this is not zero and there's an + + align:start position:0% +because this is not zero and there's an + + + align:start position:0% +because this is not zero and there's an +edge from I to J or J to I I'm not + + align:start position:0% +edge from I to J or J to I I'm not + + + align:start position:0% +edge from I to J or J to I I'm not +worrying about the dire this is not a + + align:start position:0% +worrying about the dire this is not a + + + align:start position:0% +worrying about the dire this is not a +directed graph right now so this is the + + align:start position:0% +directed graph right now so this is the + + + align:start position:0% +directed graph right now so this is the +start but there's no edge here initially + + align:start position:0% +start but there's no edge here initially + + + align:start position:0% +start but there's no edge here initially +because AI K is + + align:start position:0% +because AI K is + + + align:start position:0% +because AI K is +zero and now in this graph world well + + align:start position:0% +zero and now in this graph world well + + + align:start position:0% +zero and now in this graph world well +it's so small we can just focus on the + + align:start position:0% +it's so small we can just focus on the + + + align:start position:0% +it's so small we can just focus on the +part that's going to change a little the + + align:start position:0% +part that's going to change a little the + + + align:start position:0% +part that's going to change a little the +rest of all the other uh + + align:start position:0% +rest of all the other uh + + + align:start position:0% +rest of all the other uh +rows uh have their nodes and all the + + align:start position:0% +rows uh have their nodes and all the + + + align:start position:0% +rows uh have their nodes and all the +other nonzero entries have their edges + + align:start position:0% +other nonzero entries have their edges + + + align:start position:0% +other nonzero entries have their edges +so this is a tiny part of the the big + + align:start position:0% +so this is a tiny part of the the big + + + align:start position:0% +so this is a tiny part of the the big +graph uh but what happens to this tiny + + align:start position:0% +graph uh but what happens to this tiny + + + align:start position:0% +graph uh but what happens to this tiny +part okay so again I I want to see the + + align:start position:0% +part okay so again I I want to see the + + + align:start position:0% +part okay so again I I want to see the +same elimination step just uh this way + + align:start position:0% +same elimination step just uh this way + + + align:start position:0% +same elimination step just uh this way +in the graph world okay so after after + + align:start position:0% +in the graph world okay so after after + + + align:start position:0% +in the graph world okay so after after +what what edges are + + align:start position:0% +what what edges are + + + align:start position:0% +what what edges are +there so again it's j i and + + align:start position:0% +there so again it's j i and + + + align:start position:0% +there so again it's j i and +K and after I do elimination well J is + + align:start position:0% +K and after I do elimination well J is + + + align:start position:0% +K and after I do elimination well J is +still connected to K that's still there + + align:start position:0% +still connected to K that's still there + + + align:start position:0% +still connected to K that's still there +no + + align:start position:0% +no + + + align:start position:0% +no +change J is no longer connected to I + + align:start position:0% +change J is no longer connected to I + + + align:start position:0% +change J is no longer connected to I +because elimination killed that edge but + + align:start position:0% +because elimination killed that edge but + + + align:start position:0% +because elimination killed that edge but +elimination created a new Edge I de K so + + align:start position:0% +elimination created a new Edge I de K so + + + align:start position:0% +elimination created a new Edge I de K so +that's that's essentially what + + align:start position:0% +that's that's essentially what + + + align:start position:0% +that's that's essentially what +elimination does maybe we can say it in + + align:start position:0% +elimination does maybe we can say it in + + + align:start position:0% +elimination does maybe we can say it in +words when it so when when this when + + align:start position:0% +words when it so when when this when + + + align:start position:0% +words when it so when when this when +this Edge + + align:start position:0% + + + + align:start position:0% + +disappears at the same time we + + align:start position:0% +disappears at the same time we + + + align:start position:0% +disappears at the same time we +create new + + align:start position:0% +create new + + + align:start position:0% +create new +edges from but connecting any two + + align:start position:0% +edges from but connecting any two + + + align:start position:0% +edges from but connecting any two +nodes that were both connected to J you + + align:start position:0% +nodes that were both connected to J you + + + align:start position:0% +nodes that were both connected to J you +see that point if if if I'm using J as + + align:start position:0% +see that point if if if I'm using J as + + + align:start position:0% +see that point if if if I'm using J as +the pivot row + + align:start position:0% +the pivot row + + + align:start position:0% +the pivot row +and I look on that row and say + + align:start position:0% + + + + align:start position:0% + +what what non-zeros are there what edges + + align:start position:0% +what what non-zeros are there what edges + + + align:start position:0% +what what non-zeros are there what edges +are connected to J and I see + + align:start position:0% +are connected to J and I see + + + align:start position:0% +are connected to J and I see +one and then if I use if I when I do + + align:start position:0% +one and then if I use if I when I do + + + align:start position:0% +one and then if I use if I when I do +elimination I'm going to introduce + + align:start position:0% +elimination I'm going to introduce + + + align:start position:0% +elimination I'm going to introduce +exactly as happened here a new + + align:start position:0% +exactly as happened here a new + + + align:start position:0% +exactly as happened here a new +Edge between any pair that were both + + align:start position:0% +Edge between any pair that were both + + + align:start position:0% +Edge between any pair that were both +connected to J so we're kind of fighting + + align:start position:0% +connected to J so we're kind of fighting + + + align:start position:0% +connected to J so we're kind of fighting +against creeping + + align:start position:0% +against creeping + + + align:start position:0% +against creeping +uh fill + + align:start position:0% +uh fill + + + align:start position:0% +uh fill +in and the question is what order should + + align:start position:0% +in and the question is what order should + + + align:start position:0% +in and the question is what order should +we do these eliminations so now think of + + align:start position:0% +we do these eliminations so now think of + + + align:start position:0% +we do these eliminations so now think of +a larger + + align:start position:0% +a larger + + + align:start position:0% +a larger +graph + + align:start position:0% +graph + + + align:start position:0% +graph +actually I guess we could somehow think + + align:start position:0% +actually I guess we could somehow think + + + align:start position:0% +actually I guess we could somehow think +of + + align:start position:0% +of + + + align:start position:0% +of +that I guess maybe we could try to + + align:start position:0% +that I guess maybe we could try to + + + align:start position:0% +that I guess maybe we could try to +visualize it but maybe not not succeed + + align:start position:0% +visualize it but maybe not not succeed + + + align:start position:0% +visualize it but maybe not not succeed +so the graph for this um for + + align:start position:0% +so the graph for this um for + + + align:start position:0% +so the graph for this um for +that problem + + align:start position:0% +that problem + + + align:start position:0% +that problem +well could that serve as the graph I + + align:start position:0% +well could that serve as the graph I + + + align:start position:0% +well could that serve as the graph I +guess it could really well I would + + align:start position:0% +guess it could really well I would + + + align:start position:0% +guess it could really well I would +remove i' whiz away the the uh if I'm + + align:start position:0% +remove i' whiz away the the uh if I'm + + + align:start position:0% +remove i' whiz away the the uh if I'm +given the values on the outer edges then + + align:start position:0% +given the values on the outer edges then + + + align:start position:0% +given the values on the outer edges then +I would remove all those but essentially + + align:start position:0% +I would remove all those but essentially + + + align:start position:0% +I would remove all those but essentially +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +graph for that Matrix right well yeah + + align:start position:0% +graph for that Matrix right well yeah + + + align:start position:0% +graph for that Matrix right well yeah +yeah if I number each of the nodes 1 to + + align:start position:0% +yeah if I number each of the nodes 1 to + + + align:start position:0% +yeah if I number each of the nodes 1 to +16 and I would do the numbering the way + + align:start position:0% +16 and I would do the numbering the way + + + align:start position:0% +16 and I would do the numbering the way +I did to produce that Matrix now the the + + align:start position:0% +I did to produce that Matrix now the the + + + align:start position:0% +I did to produce that Matrix now the the +whole question is if I do some different + + align:start position:0% +whole question is if I do some different + + + align:start position:0% +whole question is if I do some different +numbering + + align:start position:0% +numbering + + + align:start position:0% +numbering +will I I'll still that will shift around + + align:start position:0% +will I I'll still that will shift around + + + align:start position:0% +will I I'll still that will shift around +that'll just be a permutation Matrix + + align:start position:0% +that'll just be a permutation Matrix + + + align:start position:0% +that'll just be a permutation Matrix +right if I do a different numbering so + + align:start position:0% +right if I do a different numbering so + + + align:start position:0% +right if I do a different numbering so +Matrix wise I have my Matrix + + align:start position:0% + + + + align:start position:0% + +k2d what what what happens Matrix wise + + align:start position:0% +k2d what what what happens Matrix wise + + + align:start position:0% +k2d what what what happens Matrix wise +for a if I do a a numbering a a + + align:start position:0% +for a if I do a a numbering a a + + + align:start position:0% +for a if I do a a numbering a a +different numbering a reordering that + + align:start position:0% +different numbering a reordering that + + + align:start position:0% +different numbering a reordering that +just permutes + + align:start position:0% +just permutes + + + align:start position:0% +just permutes +the uh unknowns and the + + align:start position:0% +the uh unknowns and the + + + align:start position:0% +the uh unknowns and the +equations so really what happens is some + + align:start position:0% +equations so really what happens is some + + + align:start position:0% +equations so really what happens is some +permutation multiplies k2d on the left + + align:start position:0% +permutation multiplies k2d on the left + + + align:start position:0% +permutation multiplies k2d on the left +and its transpose does the same thing to + + align:start position:0% +and its transpose does the same thing to + + + align:start position:0% +and its transpose does the same thing to +the columns on the right because the + + align:start position:0% +the columns on the right because the + + + align:start position:0% +the columns on the right because the +this permutation will change the order + + align:start position:0% +this permutation will change the order + + + align:start position:0% +this permutation will change the order +of the + + align:start position:0% +of the + + + align:start position:0% +of the +equations this permutation will reorder + + align:start position:0% +equations this permutation will reorder + + + align:start position:0% +equations this permutation will reorder +The + + align:start position:0% +The + + + align:start position:0% +The +Columns to to come back to bring the + + align:start position:0% +Columns to to come back to bring the + + + align:start position:0% +Columns to to come back to bring the +diagonal back onto the diagonal but in a + + align:start position:0% +diagonal back onto the diagonal but in a + + + align:start position:0% +diagonal back onto the diagonal but in a +different order well we won't know it + + align:start position:0% +different order well we won't know it + + + align:start position:0% +different order well we won't know it +with all those fours but that that will + + align:start position:0% +with all those fours but that that will + + + align:start position:0% +with all those fours but that that will +have again all the fours on the diagonal + + align:start position:0% +have again all the fours on the diagonal + + + align:start position:0% +have again all the fours on the diagonal +but the minus ones are moved around of + + align:start position:0% +but the minus ones are moved around of + + + align:start position:0% +but the minus ones are moved around of +course none have disappeared or or been + + align:start position:0% +course none have disappeared or or been + + + align:start position:0% +course none have disappeared or or been +created by that it's just that's giving + + align:start position:0% +created by that it's just that's giving + + + align:start position:0% +created by that it's just that's giving +us a new order and so that's the order + + align:start position:0% +us a new order and so that's the order + + + align:start position:0% +us a new order and so that's the order +order reordering Matrix wise what's the + + align:start position:0% +order reordering Matrix wise what's the + + + align:start position:0% +order reordering Matrix wise what's the +reordering graph wise graph wise would + + align:start position:0% +reordering graph wise graph wise would + + + align:start position:0% +reordering graph wise graph wise would +be instead of this numbering of unknowns + + align:start position:0% +be instead of this numbering of unknowns + + + align:start position:0% +be instead of this numbering of unknowns +one 2 2 3 4 5 6 7 8 and so on 9 10 11 12 + + align:start position:0% +one 2 2 3 4 5 6 7 8 and so on 9 10 11 12 + + + align:start position:0% +one 2 2 3 4 5 6 7 8 and so on 9 10 11 12 +13 14 15 16 we have a different order + + align:start position:0% +13 14 15 16 we have a different order + + + align:start position:0% +13 14 15 16 we have a different order +different numbering so there it's a the + + align:start position:0% +different numbering so there it's a the + + + align:start position:0% +different numbering so there it's a the +the computations the the computer + + align:start position:0% +the computations the the computer + + + align:start position:0% +the computations the the computer +science aspect you could say uh is not + + align:start position:0% +science aspect you could say uh is not + + + align:start position:0% +science aspect you could say uh is not +going to be difficult actually we should + + align:start position:0% +going to be difficult actually we should + + + align:start position:0% +going to be difficult actually we should +think and maybe we'll think in a + + align:start position:0% +think and maybe we'll think in a + + + align:start position:0% +think and maybe we'll think in a +minute from for the from the computer + + align:start position:0% +minute from for the from the computer + + + align:start position:0% +minute from for the from the computer +science aspect the the the actual + + align:start position:0% +science aspect the the the actual + + + align:start position:0% +science aspect the the the actual +execution I'm probably not I'm certainly + + align:start position:0% +execution I'm probably not I'm certainly + + + align:start position:0% +execution I'm probably not I'm certainly +not going to write out a permutation + + align:start position:0% +not going to write out a permutation + + + align:start position:0% +not going to write out a permutation +Matrix that's ridiculous I'm not going + + align:start position:0% +Matrix that's ridiculous I'm not going + + + align:start position:0% +Matrix that's ridiculous I'm not going +to draw a graph and keep + + align:start position:0% +to draw a graph and keep + + + align:start position:0% +to draw a graph and keep +that I I'll keep some list of of non of + + align:start position:0% +that I I'll keep some list of of non of + + + align:start position:0% +that I I'll keep some list of of non of +positions for nonzeros so we'll say a + + align:start position:0% +positions for nonzeros so we'll say a + + + align:start position:0% +positions for nonzeros so we'll say a +word about that list later so so I'm but + + align:start position:0% +word about that list later so so I'm but + + + align:start position:0% +word about that list later so so I'm but +here I'm trying to say how do we get an + + align:start position:0% +here I'm trying to say how do we get an + + + align:start position:0% +here I'm trying to say how do we get an +idea of what the effective reordering is + + align:start position:0% +idea of what the effective reordering is + + + align:start position:0% +idea of what the effective reordering is +and what a good reordering would be so + + align:start position:0% +and what a good reordering would be so + + + align:start position:0% +and what a good reordering would be so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +here this is a specific reordering that + + align:start position:0% +here this is a specific reordering that + + + align:start position:0% +here this is a specific reordering that +I want to mention right + + align:start position:0% +I want to mention right + + + align:start position:0% +I want to mention right +away because it's so + + align:start position:0% +away because it's so + + + align:start position:0% +away because it's so +straightforward you you can get the idea + + align:start position:0% +straightforward you you can get the idea + + + align:start position:0% +straightforward you you can get the idea +uh of the red black + + align:start position:0% +uh of the red black + + + align:start position:0% +uh of the red black +ordering um without any big + + align:start position:0% +ordering um without any big + + + align:start position:0% +ordering um without any big +computation this is + + align:start position:0% +computation this is + + + align:start position:0% +computation this is +the fundamentally the the winner this is + + align:start position:0% +the fundamentally the the winner this is + + + align:start position:0% +the fundamentally the the winner this is +what people use all the time and and + + align:start position:0% +what people use all the time and and + + + align:start position:0% +what people use all the time and and +uh matlabs backslash is going to have + + align:start position:0% +uh matlabs backslash is going to have + + + align:start position:0% +uh matlabs backslash is going to have +that + + align:start position:0% +that + + + align:start position:0% +that +available um and uh in inside this the + + align:start position:0% +available um and uh in inside this the + + + align:start position:0% +available um and uh in inside this the +the the codes that are called are + + align:start position:0% +the the codes that are called are + + + align:start position:0% +the the codes that are called are +the column or symmetric Matrix + + align:start position:0% +the column or symmetric Matrix + + + align:start position:0% +the column or symmetric Matrix +approximate minimum + + align:start position:0% +approximate minimum + + + align:start position:0% +approximate minimum +degree so that's what this AMD means + + align:start position:0% + + + + align:start position:0% + +approximate minimum degree + + align:start position:0% +approximate minimum degree + + + align:start position:0% +approximate minimum degree +so that's the basic uh idea that uh I'll + + align:start position:0% +so that's the basic uh idea that uh I'll + + + align:start position:0% +so that's the basic uh idea that uh I'll +come back to as soon as I've just drawn + + align:start position:0% +come back to as soon as I've just drawn + + + align:start position:0% +come back to as soon as I've just drawn +the red black picture and then uh it's + + align:start position:0% +the red black picture and then uh it's + + + align:start position:0% +the red black picture and then uh it's +so important that people don't stop + + align:start position:0% +so important that people don't stop + + + align:start position:0% +so important that people don't stop +thinking uh and then so another uh sort + + align:start position:0% +thinking uh and then so another uh sort + + + align:start position:0% +thinking uh and then so another uh sort +of uh High Lev picture of what how to do + + align:start position:0% +of uh High Lev picture of what how to do + + + align:start position:0% +of uh High Lev picture of what how to do +an ordering is look for graph separator + + align:start position:0% +an ordering is look for graph separator + + + align:start position:0% +an ordering is look for graph separator +that's become a big a big uh uh step in + + align:start position:0% +that's become a big a big uh uh step in + + + align:start position:0% +that's become a big a big uh uh step in +the world of uh comp computational graph + + align:start position:0% +the world of uh comp computational graph + + + align:start position:0% +the world of uh comp computational graph +Theory and that leads to a something + + align:start position:0% +Theory and that leads to a something + + + align:start position:0% +Theory and that leads to a something +called Nesta dissection which is uh + + align:start position:0% +called Nesta dissection which is uh + + + align:start position:0% +called Nesta dissection which is uh +separators of separators of separators + + align:start position:0% +separators of separators of separators + + + align:start position:0% +separators of separators of separators +the usual uh keep going with the same + + align:start position:0% +the usual uh keep going with the same + + + align:start position:0% +the usual uh keep going with the same +idea that you see in in uh algorithms + + align:start position:0% +idea that you see in in uh algorithms + + + align:start position:0% +idea that you see in in uh algorithms +okay what about red + + align:start position:0% +okay what about red + + + align:start position:0% +okay what about red +black red black I'm simp simply going to + + align:start position:0% +black red black I'm simp simply going to + + + align:start position:0% +black red black I'm simp simply going to +imagine that this is a checker board + + align:start position:0% +imagine that this is a checker board + + + align:start position:0% +imagine that this is a checker board +well it's the nodes that I'm looking at + + align:start position:0% +well it's the nodes that I'm looking at + + + align:start position:0% +well it's the nodes that I'm looking at +not the squares so + + align:start position:0% +not the squares so + + + align:start position:0% +not the squares so +imagine so that's red black red black so + + align:start position:0% +imagine so that's red black red black so + + + align:start position:0% +imagine so that's red black red black so +I'm going to number first I'm going to + + align:start position:0% +I'm going to number first I'm going to + + + align:start position:0% +I'm going to number first I'm going to +take all the Reds first so so that uh + + align:start position:0% +take all the Reds first so so that uh + + + align:start position:0% +take all the Reds first so so that uh +I'm changing this numbering now to take + + align:start position:0% +I'm changing this numbering now to take + + + align:start position:0% +I'm changing this numbering now to take +all the + + align:start position:0% +all the + + + align:start position:0% +all the +Reds + + align:start position:0% +Reds + + + align:start position:0% +Reds + + align:start position:0% + + + align:start position:0% +2 3 4 5 5 6 7 8 and now all the blacks 9 + + align:start position:0% +2 3 4 5 5 6 7 8 and now all the blacks 9 + + + align:start position:0% +2 3 4 5 5 6 7 8 and now all the blacks 9 +10 11 12 and so on I'll stop there so + + align:start position:0% +10 11 12 and so on I'll stop there so + + + align:start position:0% +10 11 12 and so on I'll stop there so +you your eye will know how to fill in + + align:start position:0% +you your eye will know how to fill in + + + align:start position:0% +you your eye will know how to fill in +what what's the point of that if I take + + align:start position:0% +what what's the point of that if I take + + + align:start position:0% +what what's the point of that if I take +a red + + align:start position:0% +a red + + + align:start position:0% +a red +node and look suppose this first one is + + align:start position:0% +node and look suppose this first one is + + + align:start position:0% +node and look suppose this first one is +a red node as it + + align:start position:0% +a red node as it + + + align:start position:0% +a red node as it +is okay then what about the what do I + + align:start position:0% +is okay then what about the what do I + + + align:start position:0% +is okay then what about the what do I +know about the positions of those minus + + align:start position:0% +know about the positions of those minus + + + align:start position:0% +know about the positions of those minus +ones the the nonzeros in The Matrix + + align:start position:0% +ones the the nonzeros in The Matrix + + + align:start position:0% +ones the the nonzeros in The Matrix +they're associated + + align:start position:0% +they're associated + + + align:start position:0% +they're associated +with black nodes right the the neighbors + + align:start position:0% +with black nodes right the the neighbors + + + align:start position:0% +with black nodes right the the neighbors +of this node number one + + align:start position:0% +of this node number one + + + align:start position:0% +of this node number one +are black that's they have the black + + align:start position:0% +are black that's they have the black + + + align:start position:0% +are black that's they have the black +ones have numbers from 9 to 16 so the + + align:start position:0% +ones have numbers from 9 to 16 so the + + + align:start position:0% +ones have numbers from 9 to 16 so the +the black well everybody sees it that + + align:start position:0% +the black well everybody sees it that + + + align:start position:0% +the black well everybody sees it that +with this + + align:start position:0% + + + + align:start position:0% + +molecule that has a four in the center + + align:start position:0% +molecule that has a four in the center + + + align:start position:0% +molecule that has a four in the center +and minus ones beside it those minus + + align:start position:0% +and minus ones beside it those minus + + + align:start position:0% +and minus ones beside it those minus +ones are associated with nodes of the + + align:start position:0% +ones are associated with nodes of the + + + align:start position:0% +ones are associated with nodes of the +opposite + + align:start position:0% +opposite + + + align:start position:0% +opposite +color and that's what we see here in the + + align:start position:0% +color and that's what we see here in the + + + align:start position:0% +color and that's what we see here in the +actual numbering so what does the Matrix + + align:start position:0% +actual numbering so what does the Matrix + + + align:start position:0% +actual numbering so what does the Matrix +become what does this if I do that + + align:start position:0% +become what does this if I do that + + + align:start position:0% +become what does this if I do that +permutation the permutation that's + + align:start position:0% +permutation the permutation that's + + + align:start position:0% +permutation the permutation that's +associated with that + + align:start position:0% +associated with that + + + align:start position:0% +associated with that +renumbering what will the same Matrix + + align:start position:0% +renumbering what will the same Matrix + + + align:start position:0% +renumbering what will the same Matrix +well here's the same Matrix but now I'm + + align:start position:0% +well here's the same Matrix but now I'm + + + align:start position:0% +well here's the same Matrix but now I'm +permuting it and so what does it look + + align:start position:0% +permuting it and so what does it look + + + align:start position:0% +permuting it and so what does it look +like maybe I can draw it small I think I + + align:start position:0% +like maybe I can draw it small I think I + + + align:start position:0% +like maybe I can draw it small I think I +probably + + align:start position:0% + + + + align:start position:0% + +can so in this pretty special situation + + align:start position:0% +can so in this pretty special situation + + + align:start position:0% +can so in this pretty special situation +where the red nodes are not connected to + + align:start position:0% +where the red nodes are not connected to + + + align:start position:0% +where the red nodes are not connected to +any other red nodes only to themselves I + + align:start position:0% +any other red nodes only to themselves I + + + align:start position:0% +any other red nodes only to themselves I +think I'll only see the 4i this is red + + align:start position:0% +think I'll only see the 4i this is red + + + align:start position:0% +think I'll only see the 4i this is red +to + + align:start position:0% +to + + + align:start position:0% +to +Red those are the eight red nodes it's + + align:start position:0% +Red those are the eight red nodes it's + + + align:start position:0% +Red those are the eight red nodes it's +an 8 by8 identity Matrix times four and + + align:start position:0% +an 8 by8 identity Matrix times four and + + + align:start position:0% +an 8 by8 identity Matrix times four and +the blacks are only connected to the + + align:start position:0% +the blacks are only connected to the + + + align:start position:0% +the blacks are only connected to the +black + + align:start position:0% + + + + align:start position:0% + +and all the minus + + align:start position:0% +and all the minus + + + align:start position:0% +and all the minus +ones are in the are in our connections + + align:start position:0% +ones are in the are in our connections + + + align:start position:0% +ones are in the are in our connections +between red and black that is this far + + align:start position:0% +between red and black that is this far + + + align:start position:0% +between red and black that is this far +off the diagonal what shall I call it B + + align:start position:0% +off the diagonal what shall I call it B + + + align:start position:0% +off the diagonal what shall I call it B +I'll just pick a letter b and be + + align:start position:0% +I'll just pick a letter b and be + + + align:start position:0% +I'll just pick a letter b and be +transposed probably because I know the + + align:start position:0% +transposed probably because I know the + + + align:start position:0% +transposed probably because I know the +Matrix is going to stay symmetric if it + + align:start position:0% +Matrix is going to stay symmetric if it + + + align:start position:0% +Matrix is going to stay symmetric if it +if it started symmetric as it did then + + align:start position:0% +if it started symmetric as it did then + + + align:start position:0% +if it started symmetric as it did then +this operation of reordering rows and + + align:start position:0% +this operation of reordering rows and + + + align:start position:0% +this operation of reordering rows and +columns compatibly is going to leave it + + align:start position:0% +columns compatibly is going to leave it + + + align:start position:0% +columns compatibly is going to leave it +symmetric and it must look something + + align:start position:0% +symmetric and it must look something + + + align:start position:0% +symmetric and it must look something +like this okay is that Matrix more + + align:start position:0% +like this okay is that Matrix more + + + align:start position:0% +like this okay is that Matrix more +sparse than before no it's got the same + + align:start position:0% +sparse than before no it's got the same + + + align:start position:0% +sparse than before no it's got the same +minus ones they're just all pushed up + + align:start position:0% +minus ones they're just all pushed up + + + align:start position:0% +minus ones they're just all pushed up +into this + + align:start position:0% +into this + + + align:start position:0% +into this +corner will it have fill some fill in as + + align:start position:0% +corner will it have fill some fill in as + + + align:start position:0% +corner will it have fill some fill in as +we go + + align:start position:0% +we go + + + align:start position:0% +we go +forward what's the answer on that one as + + align:start position:0% +forward what's the answer on that one as + + + align:start position:0% +forward what's the answer on that one as +I go + + align:start position:0% +I go + + + align:start position:0% +I go +forward maybe I should I haven't really + + align:start position:0% +forward maybe I should I haven't really + + + align:start position:0% +forward maybe I should I haven't really +thought that through my instinct is yes + + align:start position:0% +thought that through my instinct is yes + + + align:start position:0% +thought that through my instinct is yes +we'll have fill in + + align:start position:0% +we'll have fill in + + + align:start position:0% +we'll have fill in +will we have more fill in or less fill + + align:start position:0% +will we have more fill in or less fill + + + align:start position:0% +will we have more fill in or less fill +in than the than the uh row row by row + + align:start position:0% +in than the than the uh row row by row + + + align:start position:0% +in than the than the uh row row by row +ordering I should know the answer I + + align:start position:0% +ordering I should know the answer I + + + align:start position:0% +ordering I should know the answer I +think I'd probably ask uh the machine to + + align:start position:0% +think I'd probably ask uh the machine to + + + align:start position:0% +think I'd probably ask uh the machine to +tell + + align:start position:0% +tell + + + align:start position:0% +tell +me my guess is probably not more and we + + align:start position:0% +me my guess is probably not more and we + + + align:start position:0% +me my guess is probably not more and we +can + + align:start position:0% +can + + + align:start position:0% +can +well why do I think probably this is + + align:start position:0% +well why do I think probably this is + + + align:start position:0% +well why do I think probably this is +better and of course I should know + + align:start position:0% +better and of course I should know + + + align:start position:0% +better and of course I should know +exactly in general it's better to put + + align:start position:0% +exactly in general it's better to put + + + align:start position:0% +exactly in general it's better to put +off the evil day here that is this this + + align:start position:0% +off the evil day here that is this this + + + align:start position:0% +off the evil day here that is this this +goes through the first half of + + align:start position:0% +goes through the first half of + + + align:start position:0% +goes through the first half of +elimination CL I + + align:start position:0% +elimination CL I + + + align:start position:0% +elimination CL I +mean that you you know what I'm think + + align:start position:0% +mean that you you know what I'm think + + + align:start position:0% +mean that you you know what I'm think +thinking here all the off diagonals have + + align:start position:0% +thinking here all the off diagonals have + + + align:start position:0% +thinking here all the off diagonals have +been sort of pushed down in The + + align:start position:0% +been sort of pushed down in The + + + align:start position:0% +been sort of pushed down in The +Matrix so that now let me do an example + + align:start position:0% +Matrix so that now let me do an example + + + align:start position:0% +Matrix so that now let me do an example +that's it shows that why that's good + + align:start position:0% +that's it shows that why that's good + + + align:start position:0% +that's it shows that why that's good +suppose my Matrix + + align:start position:0% + + + + align:start position:0% + +has a nonzero diagonal and by the way + + align:start position:0% +has a nonzero diagonal and by the way + + + align:start position:0% +has a nonzero diagonal and by the way +the first uh step in + + align:start position:0% +the first uh step in + + + align:start position:0% +the first uh step in +um in the in the good codes for + + align:start position:0% +um in the in the good codes for + + + align:start position:0% +um in the in the good codes for +elimination do a permutation exactly to + + align:start position:0% +elimination do a permutation exactly to + + + align:start position:0% +elimination do a permutation exactly to +produce a non-zero diagonal so you're + + align:start position:0% +produce a non-zero diagonal so you're + + + align:start position:0% +produce a non-zero diagonal so you're +you're you're you're okay to start you + + align:start position:0% +you're you're you're okay to start you + + + align:start position:0% +you're you're you're okay to start you +know where you you are now + + align:start position:0% +know where you you are now + + + align:start position:0% +know where you you are now +suppose that the nonzeros + + align:start position:0% +suppose that the nonzeros + + + align:start position:0% +suppose that the nonzeros +all show up and I'll make the Matrix + + align:start position:0% +all show up and I'll make the Matrix + + + align:start position:0% +all show up and I'll make the Matrix +symmetric so th that's the nonzero + + align:start position:0% +symmetric so th that's the nonzero + + + align:start position:0% +symmetric so th that's the nonzero +pattern and and my point is that's a + + align:start position:0% +pattern and and my point is that's a + + + align:start position:0% +pattern and and my point is that's a +very good nonzero + + align:start position:0% +very good nonzero + + + align:start position:0% +very good nonzero +pattern why is it good it's good because + + align:start position:0% +pattern why is it good it's good because + + + align:start position:0% +pattern why is it good it's good because +there's no fill in whatever when I + + align:start position:0% +there's no fill in whatever when I + + + align:start position:0% +there's no fill in whatever when I +subtract some multiple when I go to make + + align:start position:0% +subtract some multiple when I go to make + + + align:start position:0% +subtract some multiple when I go to make +this zero to eliminate it I subtract a + + align:start position:0% +this zero to eliminate it I subtract a + + + align:start position:0% +this zero to eliminate it I subtract a +multiple using the first pivot it + + align:start position:0% +multiple using the first pivot it + + + align:start position:0% +multiple using the first pivot it +changes that but it doesn't fill in + + align:start position:0% +changes that but it doesn't fill in + + + align:start position:0% +changes that but it doesn't fill in +anything new all the the only operations + + align:start position:0% +anything new all the the only operations + + + align:start position:0% +anything new all the the only operations +required are are operating on the last + + align:start position:0% +required are are operating on the last + + + align:start position:0% +required are are operating on the last +row which is already full so there's an + + align:start position:0% +row which is already full so there's an + + + align:start position:0% +row which is already full so there's an +example in which the + + align:start position:0% +example in which the + + + align:start position:0% +example in which the +bandwidth see normally the bandwidth is + + align:start position:0% +bandwidth see normally the bandwidth is + + + align:start position:0% +bandwidth see normally the bandwidth is +a like a good guide but that's only for + + align:start position:0% +a like a good guide but that's only for + + + align:start position:0% +a like a good guide but that's only for +like pretty full bands here's a matrix + + align:start position:0% +like pretty full bands here's a matrix + + + align:start position:0% +like pretty full bands here's a matrix +that's not banded really it's bandwidth + + align:start position:0% +that's not banded really it's bandwidth + + + align:start position:0% +that's not banded really it's bandwidth +is the full uh five I have five I have + + align:start position:0% +is the full uh five I have five I have + + + align:start position:0% +is the full uh five I have five I have +to go out + + align:start position:0% +to go out + + + align:start position:0% +to go out +five to uh columns until I get the last + + align:start position:0% +five to uh columns until I get the last + + + align:start position:0% +five to uh columns until I get the last +until I get the the + + align:start position:0% +until I get the the + + + align:start position:0% +until I get the the +nonzeros so that has a big bandwidth so + + align:start position:0% +nonzeros so that has a big bandwidth so + + + align:start position:0% +nonzeros so that has a big bandwidth so +bandwidth W the bandwidth W is + + align:start position:0% +bandwidth W the bandwidth W is + + + align:start position:0% +bandwidth W the bandwidth W is +large but it's the right it's the + + align:start position:0% +large but it's the right it's the + + + align:start position:0% +large but it's the right it's the +perfect ordering but no + + align:start position:0% + + + + align:start position:0% + +fill I I don't F anything you realize + + align:start position:0% +fill I I don't F anything you realize + + + align:start position:0% +fill I I don't F anything you realize +that for banded Matrix + + align:start position:0% +that for banded Matrix + + + align:start position:0% +that for banded Matrix +we won't have fill in outside the band + + align:start position:0% +we won't have fill in outside the band + + + align:start position:0% +we won't have fill in outside the band +our our our our concern is for fill in + + align:start position:0% +our our our our concern is for fill in + + + align:start position:0% +our our our our concern is for fill in +inside the band and here we don't have + + align:start position:0% +inside the band and here we don't have + + + align:start position:0% +inside the band and here we don't have +any because the the bad row and actually + + align:start position:0% +any because the the bad row and actually + + + align:start position:0% +any because the the bad row and actually +it often happens in + + align:start position:0% +it often happens in + + + align:start position:0% +it often happens in +um in some lease squares and other + + align:start position:0% +um in some lease squares and other + + + align:start position:0% +um in some lease squares and other +problems that you might this isn't quite + + align:start position:0% +problems that you might this isn't quite + + + align:start position:0% +problems that you might this isn't quite +as stupid a matrix as you might think uh + + align:start position:0% +as stupid a matrix as you might think uh + + + align:start position:0% +as stupid a matrix as you might think uh +these might be blocks rather than single + + align:start position:0% +these might be blocks rather than single + + + align:start position:0% +these might be blocks rather than single +entries you often want to think + + align:start position:0% +entries you often want to think + + + align:start position:0% +entries you often want to think +blockwise about a + + align:start position:0% +blockwise about a + + + align:start position:0% +blockwise about a +matrix and and when would you you might + + align:start position:0% +matrix and and when would you you might + + + align:start position:0% +matrix and and when would you you might +think how why would you have a have a + + align:start position:0% +think how why would you have a have a + + + align:start position:0% +think how why would you have a have a +matrix that was well well separated uh + + align:start position:0% +matrix that was well well separated uh + + + align:start position:0% +matrix that was well well separated uh +with block diagonal which is really good + + align:start position:0% +with block diagonal which is really good + + + align:start position:0% +with block diagonal which is really good +and then a few rows that are full that + + align:start position:0% +and then a few rows that are full that + + + align:start position:0% +and then a few rows that are full that +seems sort of unlikely but I guess I + + align:start position:0% +seems sort of unlikely but I guess I + + + align:start position:0% +seems sort of unlikely but I guess I +want to say it isn't if you had a + + align:start position:0% +want to say it isn't if you had a + + + align:start position:0% +want to say it isn't if you had a +problem in these squares + + align:start position:0% +problem in these squares + + + align:start position:0% +problem in these squares +minimizing some expression involving + + align:start position:0% +minimizing some expression involving + + + align:start position:0% +minimizing some expression involving +that + + align:start position:0% +that + + + align:start position:0% +that +Matrix the block diagonal part but with + + align:start position:0% +Matrix the block diagonal part but with + + + align:start position:0% +Matrix the block diagonal part but with +a constraint that maybe the sum of all + + align:start position:0% +a constraint that maybe the sum of all + + + align:start position:0% +a constraint that maybe the sum of all +the unknowns has to be + + align:start position:0% +the unknowns has to be + + + align:start position:0% +the unknowns has to be +one then when you use a lrange + + align:start position:0% +one then when you use a lrange + + + align:start position:0% +one then when you use a lrange +multiplier to bring that constraint into + + align:start position:0% +multiplier to bring that constraint into + + + align:start position:0% +multiplier to bring that constraint into +the problem into the Matrix that's going + + align:start position:0% +the problem into the Matrix that's going + + + align:start position:0% +the problem into the Matrix that's going +to show like that and the beauty of the + + align:start position:0% +to show like that and the beauty of the + + + align:start position:0% +to show like that and the beauty of the +lron multiplier + + align:start position:0% +lron multiplier + + + align:start position:0% +lron multiplier +devices that also that it'll produce a + + align:start position:0% +devices that also that it'll produce a + + + align:start position:0% +devices that also that it'll produce a +symmetric uh column there well we'll see + + align:start position:0% +symmetric uh column there well we'll see + + + align:start position:0% +symmetric uh column there well we'll see +that in uh the third part of the course + + align:start position:0% +that in uh the third part of the course + + + align:start position:0% +that in uh the third part of the course +but I I'm just my point is that this + + align:start position:0% +but I I'm just my point is that this + + + align:start position:0% +but I I'm just my point is that this +example is not as artificial as it + + align:start position:0% +example is not as artificial as it + + + align:start position:0% +example is not as artificial as it +seems okay + + align:start position:0% +seems okay + + + align:start position:0% +seems okay +now suppose + + align:start position:0% +now suppose + + + align:start position:0% +now suppose +we had taken the bandwidth as + + align:start position:0% +we had taken the bandwidth as + + + align:start position:0% +we had taken the bandwidth as +our metric as our as our goal or + + align:start position:0% +our metric as our as our goal or + + + align:start position:0% +our metric as our as our goal or +reducing the bandwidth as our goal we + + align:start position:0% +reducing the bandwidth as our goal we + + + align:start position:0% +reducing the bandwidth as our goal we +would have made a bad + + align:start position:0% +would have made a bad + + + align:start position:0% +would have made a bad +mistake because if I if I want to do a + + align:start position:0% +mistake because if I if I want to do a + + + align:start position:0% +mistake because if I if I want to do a +permutation that reduces the bandwidth I + + align:start position:0% +permutation that reduces the bandwidth I + + + align:start position:0% +permutation that reduces the bandwidth I +better put this up in the middle + + align:start position:0% +better put this up in the middle + + + align:start position:0% +better put this up in the middle +somewhere so this is that that bad row + + align:start position:0% +somewhere so this is that that bad row + + + align:start position:0% +somewhere so this is that that bad row +comes up in the middle and then I guess + + align:start position:0% +comes up in the middle and then I guess + + + align:start position:0% +comes up in the middle and then I guess +that these are maybe whatever well + + align:start position:0% +that these are maybe whatever well + + + align:start position:0% +that these are maybe whatever well +didn't I guess I need 3 X's down + + align:start position:0% +didn't I guess I need 3 X's down + + + align:start position:0% +didn't I guess I need 3 X's down +here and what oh I'm going to do the + + align:start position:0% +here and what oh I'm going to do the + + + align:start position:0% +here and what oh I'm going to do the +same permutation from the right so that + + align:start position:0% +same permutation from the right so that + + + align:start position:0% +same permutation from the right so that +will move this column over to the + + align:start position:0% +will move this column over to the + + + align:start position:0% +will move this column over to the +middle so that would be this would be a + + align:start position:0% +middle so that would be this would be a + + + align:start position:0% +middle so that would be this would be a +a reordered this would be a p Matrix P + + align:start position:0% +a reordered this would be a p Matrix P + + + align:start position:0% +a reordered this would be a p Matrix P +transposed thing I + + align:start position:0% +transposed thing I + + + align:start position:0% +transposed thing I +think and it's got a better bandwidth + + align:start position:0% +think and it's got a better bandwidth + + + align:start position:0% +think and it's got a better bandwidth +right now now we have we're we're + + align:start position:0% +right now now we have we're we're + + + align:start position:0% +right now now we have we're we're +totally confident of all these zeros + + align:start position:0% + + + + align:start position:0% + +here but + + align:start position:0% +here but + + + align:start position:0% +here but +it will fill in where where will we get + + align:start position:0% +it will fill in where where will we get + + + align:start position:0% +it will fill in where where will we get +fill in in that Matrix so as we start + + align:start position:0% +fill in in that Matrix so as we start + + + align:start position:0% +fill in in that Matrix so as we start +we're we're we're using elimination to + + align:start position:0% +we're we're we're using elimination to + + + align:start position:0% +we're we're we're using elimination to +remove those entries no problem cuz CU + + align:start position:0% +remove those entries no problem cuz CU + + + align:start position:0% +remove those entries no problem cuz CU +that upper left corner is the way this + + align:start position:0% +that upper left corner is the way this + + + align:start position:0% +that upper left corner is the way this +big the whole Matrix was no fill in up + + align:start position:0% +big the whole Matrix was no fill in up + + + align:start position:0% +big the whole Matrix was no fill in up +to there but just as soon as we reach + + align:start position:0% +to there but just as soon as we reach + + + align:start position:0% +to there but just as soon as we reach +this one as our pivot row and use it to + + align:start position:0% +this one as our pivot row and use it to + + + align:start position:0% +this one as our pivot row and use it to +subtract multiples to to knock out those + + align:start position:0% +subtract multiples to to knock out those + + + align:start position:0% +subtract multiples to to knock out those +when I make those Zero by using that + + align:start position:0% +when I make those Zero by using that + + + align:start position:0% +when I make those Zero by using that +pivot it's going to bring the whole this + + align:start position:0% +pivot it's going to bring the whole this + + + align:start position:0% +pivot it's going to bring the whole this +will be gone at that time but this will + + align:start position:0% +will be gone at that time but this will + + + align:start position:0% +will be gone at that time but this will +be non zero and that will produce new uh + + align:start position:0% +be non zero and that will produce new uh + + + align:start position:0% +be non zero and that will produce new uh +new edges in the graph might be fun to + + align:start position:0% +new edges in the graph might be fun to + + + align:start position:0% +new edges in the graph might be fun to +look at the graph that is associated + + align:start position:0% +look at the graph that is associated + + + align:start position:0% +look at the graph that is associated +with these with this Matrix and its + + align:start position:0% +with these with this Matrix and its + + + align:start position:0% +with these with this Matrix and its +permutations but anyway you see that + + align:start position:0% +permutations but anyway you see that + + + align:start position:0% +permutations but anyway you see that +this will all fill + + align:start position:0% + + + + align:start position:0% + +in okay so again + + align:start position:0% +in okay so again + + + align:start position:0% +in okay so again +in that small problem we could really + + align:start position:0% +in that small problem we could really + + + align:start position:0% +in that small problem we could really +see what was + + align:start position:0% +see what was + + + align:start position:0% +see what was +happening in the big problem we could we + + align:start position:0% +happening in the big problem we could we + + + align:start position:0% +happening in the big problem we could we +can almost see it when we take a very + + align:start position:0% +can almost see it when we take a very + + + align:start position:0% +can almost see it when we take a very +specific highly structured permutation + + align:start position:0% +specific highly structured permutation + + + align:start position:0% +specific highly structured permutation +like red + + align:start position:0% +like red + + + align:start position:0% +like red +black although I + + align:start position:0% +black although I + + + align:start position:0% +black although I +haven't pinned down exactly what the + + align:start position:0% +haven't pinned down exactly what the + + + align:start position:0% +haven't pinned down exactly what the +count is like now I I'd be glad if + + align:start position:0% +count is like now I I'd be glad if + + + align:start position:0% +count is like now I I'd be glad if +somebody would just run a computer + + align:start position:0% +somebody would just run a computer + + + align:start position:0% +somebody would just run a computer +experiment count nonzero + + align:start position:0% +experiment count nonzero + + + align:start position:0% +experiment count nonzero +count um yeah count so what what's the + + align:start position:0% +count um yeah count so what what's the + + + align:start position:0% +count um yeah count so what what's the +good thing to count uh what's how do you + + align:start position:0% +good thing to count uh what's how do you + + + align:start position:0% +good thing to count uh what's how do you +see what the fill in finally was when + + align:start position:0% +see what the fill in finally was when + + + align:start position:0% +see what the fill in finally was when +you've done an elimination well I guess + + align:start position:0% +you've done an elimination well I guess + + + align:start position:0% +you've done an elimination well I guess +that + + align:start position:0% +that + + + align:start position:0% +that +the um the lnu factors which is what + + align:start position:0% +the um the lnu factors which is what + + + align:start position:0% +the um the lnu factors which is what +elimination produces that's where the + + align:start position:0% +elimination produces that's where the + + + align:start position:0% +elimination produces that's where the +Fillin will be so maybe I just make that + + align:start position:0% +Fillin will be so maybe I just make that + + + align:start position:0% +Fillin will be so maybe I just make that +point so that so that you could make + + align:start position:0% +point so that so that you could make + + + align:start position:0% +point so that so that you could make +these experiments that I have in mind + + align:start position:0% +these experiments that I have in mind + + + align:start position:0% +these experiments that I have in mind +and tell me what I ought to know about + + align:start position:0% +and tell me what I ought to know about + + + align:start position:0% +and tell me what I ought to know about +it so so if I have the Matrix + + align:start position:0% + + + + align:start position:0% + +k whatever whichever it is whether it's + + align:start position:0% +k whatever whichever it is whether it's + + + align:start position:0% +k whatever whichever it is whether it's +this one or this one or any + + align:start position:0% +this one or this one or any + + + align:start position:0% +this one or this one or any +other then the effect of + + align:start position:0% +other then the effect of + + + align:start position:0% +other then the effect of +elimination is to factor it into a lower + + align:start position:0% +elimination is to factor it into a lower + + + align:start position:0% +elimination is to factor it into a lower +times an upper triangular + + align:start position:0% + + + + align:start position:0% + +Matrix and in the I'll just mention the + + align:start position:0% +Matrix and in the I'll just mention the + + + align:start position:0% +Matrix and in the I'll just mention the +special case while + + align:start position:0% +special case while + + + align:start position:0% +special case while +on special positive definite + + align:start position:0% +on special positive definite + + + align:start position:0% +on special positive definite +case we could we can adjust it so that K + + align:start position:0% +case we could we can adjust it so that K + + + align:start position:0% +case we could we can adjust it so that K +is L * L transpose this is called + + align:start position:0% + + + + align:start position:0% + +keski we can arrange the the well it + + align:start position:0% +keski we can arrange the the well it + + + align:start position:0% +keski we can arrange the the well it +will happen we we can arrange the + + align:start position:0% +will happen we we can arrange the + + + align:start position:0% +will happen we we can arrange the +scaling so that + + align:start position:0% +scaling so that + + + align:start position:0% +scaling so that +um by putting a square root of pivots + + align:start position:0% +um by putting a square root of pivots + + + align:start position:0% +um by putting a square root of pivots +with L and the other square root with L + + align:start position:0% +with L and the other square root with L + + + align:start position:0% +with L and the other square root with L +transpose so keski is a matlb command Co + + align:start position:0% +transpose so keski is a matlb command Co + + + align:start position:0% +transpose so keski is a matlb command Co +chol and actually matlb if you give mat + + align:start position:0% +chol and actually matlb if you give mat + + + align:start position:0% +chol and actually matlb if you give mat +lab + + align:start position:0% +lab + + + align:start position:0% +lab +a symmetric + + align:start position:0% +a symmetric + + + align:start position:0% +a symmetric +Matrix or if you give matlb a matrix to + + align:start position:0% +Matrix or if you give matlb a matrix to + + + align:start position:0% +Matrix or if you give matlb a matrix to +work with it will first ask well it will + + align:start position:0% +work with it will first ask well it will + + + align:start position:0% +work with it will first ask well it will +ask is it symmetric if it is symmetric + + align:start position:0% +ask is it symmetric if it is symmetric + + + align:start position:0% +ask is it symmetric if it is symmetric +it will hope that it's positive definite + + align:start position:0% +it will hope that it's positive definite + + + align:start position:0% +it will hope that it's positive definite +so it will begin in + + align:start position:0% + + + + align:start position:0% + +keski it will begin to look for this + + align:start position:0% +keski it will begin to look for this + + + align:start position:0% +keski it will begin to look for this +it'll begin the the factorization which + + align:start position:0% +it'll begin the the factorization which + + + align:start position:0% +it'll begin the the factorization which +it is perfect for positive definite + + align:start position:0% +it is perfect for positive definite + + + align:start position:0% +it is perfect for positive definite +ones until + + align:start position:0% +ones until + + + align:start position:0% +ones until +it + + align:start position:0% +it + + + align:start position:0% +it +succeeds and finishes KES keski or until + + align:start position:0% +succeeds and finishes KES keski or until + + + align:start position:0% +succeeds and finishes KES keski or until +it discovers that nope a negative pivot + + align:start position:0% +it discovers that nope a negative pivot + + + align:start position:0% +it discovers that nope a negative pivot +appeared + + align:start position:0% +appeared + + + align:start position:0% +appeared +um which means which signals that the + + align:start position:0% +um which means which signals that the + + + align:start position:0% +um which means which signals that the +Matrix is not and was not originally + + align:start position:0% +Matrix is not and was not originally + + + align:start position:0% +Matrix is not and was not originally +positive definite and then then uh mat + + align:start position:0% +positive definite and then then uh mat + + + align:start position:0% +positive definite and then then uh mat +lab has to has to accept okay now I may + + align:start position:0% +lab has to has to accept okay now I may + + + align:start position:0% +lab has to has to accept okay now I may +have to do uh row exchanges pivoting + + align:start position:0% +have to do uh row exchanges pivoting + + + align:start position:0% +have to do uh row exchanges pivoting +operations and all the rest so mat lab + + align:start position:0% +operations and all the rest so mat lab + + + align:start position:0% +operations and all the rest so mat lab +sort of optimistic until it on a + + align:start position:0% +sort of optimistic until it on a + + + align:start position:0% +sort of optimistic until it on a +symmetric Matrix until it uh is told + + align:start position:0% +symmetric Matrix until it uh is told + + + align:start position:0% +symmetric Matrix until it uh is told +otherwise but not all matrices are + + align:start position:0% +otherwise but not all matrices are + + + align:start position:0% +otherwise but not all matrices are +symmetric so this would be the general + + align:start position:0% +symmetric so this would be the general + + + align:start position:0% +symmetric so this would be the general +case the general almost the general case + + align:start position:0% +case the general almost the general case + + + align:start position:0% +case the general almost the general case +I haven't included here the pivoting the + + align:start position:0% +I haven't included here the pivoting the + + + align:start position:0% +I haven't included here the pivoting the +the the row exchanges that matlb does as + + align:start position:0% +the the row exchanges that matlb does as + + + align:start position:0% +the the row exchanges that matlb does as +it as it executes elimination but let so + + align:start position:0% +it as it executes elimination but let so + + + align:start position:0% +it as it executes elimination but let so +let me just finish my sentence on L and + + align:start position:0% +let me just finish my sentence on L and + + + align:start position:0% +let me just finish my sentence on L and +u l will + + align:start position:0% +u l will + + + align:start position:0% +u l will +have the fill in in it it l will tell us + + align:start position:0% +have the fill in in it it l will tell us + + + align:start position:0% +have the fill in in it it l will tell us +and you will certainly I mean they both + + align:start position:0% +and you will certainly I mean they both + + + align:start position:0% +and you will certainly I mean they both +will you you will have these + + align:start position:0% +will you you will have these + + + align:start position:0% +will you you will have these +uh that that guy is going to be part of + + align:start position:0% +uh that that guy is going to be part of + + + align:start position:0% +uh that that guy is going to be part of +you and this + + align:start position:0% +you and this + + + align:start position:0% +you and this +one is I expect to see something there + + align:start position:0% +one is I expect to see something there + + + align:start position:0% +one is I expect to see something there +in L so so L and youu will actually + + align:start position:0% +in L so so L and youu will actually + + + align:start position:0% +in L so so L and youu will actually +exhibit the fill in so that you could + + align:start position:0% +exhibit the fill in so that you could + + + align:start position:0% +exhibit the fill in so that you could +find out how much fill in there is + + align:start position:0% +find out how much fill in there is + + + align:start position:0% +find out how much fill in there is +simply by uh counting the + + align:start position:0% +simply by uh counting the + + + align:start position:0% +simply by uh counting the +nonzeros in the matrices L and u i this + + align:start position:0% +nonzeros in the matrices L and u i this + + + align:start position:0% +nonzeros in the matrices L and u i this +is to encourage you because this is + + align:start position:0% +is to encourage you because this is + + + align:start position:0% +is to encourage you because this is +really a pretty experimental subject + + align:start position:0% +really a pretty experimental subject + + + align:start position:0% +really a pretty experimental subject +nobody + + align:start position:0% +nobody + + + align:start position:0% +nobody +um you know the best + + align:start position:0% +um you know the best + + + align:start position:0% +um you know the best +methods which or the favorite method I + + align:start position:0% +methods which or the favorite method I + + + align:start position:0% +methods which or the favorite method I +think nobody can say best probably but + + align:start position:0% +think nobody can say best probably but + + + align:start position:0% +think nobody can say best probably but +this approximate minimum degree the + + align:start position:0% +this approximate minimum degree the + + + align:start position:0% +this approximate minimum degree the +favorite method um we could prove some + + align:start position:0% +favorite method um we could prove some + + + align:start position:0% +favorite method um we could prove some +theorems to to show that it was better + + align:start position:0% +theorems to to show that it was better + + + align:start position:0% +theorems to to show that it was better +than something else but to really see is + + align:start position:0% +than something else but to really see is + + + align:start position:0% +than something else but to really see is +it successful or not in in on a wide + + align:start position:0% +it successful or not in in on a wide + + + align:start position:0% +it successful or not in in on a wide +variety of problems that's really + + align:start position:0% +variety of problems that's really + + + align:start position:0% +variety of problems that's really +experiment just try it okay now what + + align:start position:0% +experiment just try it okay now what + + + align:start position:0% +experiment just try it okay now what +does it + + align:start position:0% +does it + + + align:start position:0% +does it +mean so I looked at that specific one + + align:start position:0% +mean so I looked at that specific one + + + align:start position:0% +mean so I looked at that specific one +now I'm ready to look at the at the + + align:start position:0% +now I'm ready to look at the at the + + + align:start position:0% +now I'm ready to look at the at the +approximate minimum degree and I'll + + align:start position:0% +approximate minimum degree and I'll + + + align:start position:0% +approximate minimum degree and I'll +contrast it with the perfect minimum + + align:start position:0% + + + + align:start position:0% + +degree and there are codes for that and + + align:start position:0% +degree and there are codes for that and + + + align:start position:0% +degree and there are codes for that and +those A's become + + align:start position:0% +those A's become + + + align:start position:0% +those A's become +M's but it turns out and I don't know + + align:start position:0% +M's but it turns out and I don't know + + + align:start position:0% +M's but it turns out and I don't know +exactly why it's the case that the + + align:start position:0% +exactly why it's the case that the + + + align:start position:0% +exactly why it's the case that the +approximate minimum degree + + align:start position:0% +approximate minimum degree + + + align:start position:0% +approximate minimum degree +usually if anything it's Superior so + + align:start position:0% +usually if anything it's Superior so + + + align:start position:0% +usually if anything it's Superior so +these are the the ones to use so what + + align:start position:0% +these are the the ones to use so what + + + align:start position:0% +these are the the ones to use so what +does minimum degree mean minimum degree + + align:start position:0% +does minimum degree mean minimum degree + + + align:start position:0% +does minimum degree mean minimum degree +means let me if I took this problem oh + + align:start position:0% +means let me if I took this problem oh + + + align:start position:0% +means let me if I took this problem oh +well I should draw the graph for that + + align:start position:0% +well I should draw the graph for that + + + align:start position:0% +well I should draw the graph for that +for this Matrix so what's what does the + + align:start position:0% +for this Matrix so what's what does the + + + align:start position:0% +for this Matrix so what's what does the +graph look look like for this Matrix + + align:start position:0% +graph look look like for this Matrix + + + align:start position:0% +graph look look like for this Matrix +I've got + + align:start position:0% +I've got + + + align:start position:0% +I've got +six uh + + align:start position:0% +six uh + + + align:start position:0% +six uh +nodes so let me put six nodes in well + + align:start position:0% +nodes so let me put six nodes in well + + + align:start position:0% +nodes so let me put six nodes in well +let me put five and the and the node in + + align:start position:0% +let me put five and the and the node in + + + align:start position:0% +let me put five and the and the node in +the middle is will be the one that + + align:start position:0% +the middle is will be the one that + + + align:start position:0% +the middle is will be the one that +they're all connected to so these in + + align:start position:0% +they're all connected to so these in + + + align:start position:0% +they're all connected to so these in +this in this ordering those would be 1 2 + + align:start position:0% +this in this ordering those would be 1 2 + + + align:start position:0% +this in this ordering those would be 1 2 +3 4 5 and six and all the connections go + + align:start position:0% +3 4 5 and six and all the connections go + + + align:start position:0% +3 4 5 and six and all the connections go +into six so that's the graph for that + + align:start position:0% + + + + align:start position:0% + +Matrix and the graph for this + + align:start position:0% +Matrix and the graph for this + + + align:start position:0% +Matrix and the graph for this +one what so you probably see it better + + align:start position:0% +one what so you probably see it better + + + align:start position:0% +one what so you probably see it better +than I do well what I had originally + + align:start position:0% +than I do well what I had originally + + + align:start position:0% +than I do well what I had originally +there uh I guess this is the graph with + + align:start position:0% +there uh I guess this is the graph with + + + align:start position:0% +there uh I guess this is the graph with +the numbering 1 2 3 4 5 six this what + + align:start position:0% +the numbering 1 2 3 4 5 six this what + + + align:start position:0% +the numbering 1 2 3 4 5 six this what +what was there before before the fill in + + align:start position:0% +what was there before before the fill in + + + align:start position:0% +what was there before before the fill in +happened would the graph would look the + + align:start position:0% +happened would the graph would look the + + + align:start position:0% +happened would the graph would look the +same but the nodes would have a + + align:start position:0% +same but the nodes would have a + + + align:start position:0% +same but the nodes would have a +different numbering right 1 2 3 4 5 6 + + align:start position:0% +different numbering right 1 2 3 4 5 6 + + + align:start position:0% +different numbering right 1 2 3 4 5 6 +and then so shall I just shall I just + + align:start position:0% +and then so shall I just shall I just + + + align:start position:0% +and then so shall I just shall I just +put the bad guy here 1 2 3 4 five six + + align:start position:0% +put the bad guy here 1 2 3 4 five six + + + align:start position:0% +put the bad guy here 1 2 3 4 five six +and then what's the point that as soon + + align:start position:0% +and then what's the point that as soon + + + align:start position:0% +and then what's the point that as soon +as I um use number three to eliminate + + align:start position:0% +as I um use number three to eliminate + + + align:start position:0% +as I um use number three to eliminate +four well three was connected to five so + + align:start position:0% +four well three was connected to five so + + + align:start position:0% +four well three was connected to five so +a + + align:start position:0% +a + + + align:start position:0% +a +new Edge is going to appear there and + + align:start position:0% +new Edge is going to appear there and + + + align:start position:0% +new Edge is going to appear there and +three was connected to six three is + + align:start position:0% +three was connected to six three is + + + align:start position:0% +three was connected to six three is +connected to four when I use it a new 4 + + align:start position:0% +connected to four when I use it a new 4 + + + align:start position:0% +connected to four when I use it a new 4 +six is going to appear here so those are + + align:start position:0% +six is going to appear here so those are + + + align:start position:0% +six is going to appear here so those are +a couple of the fill-ins those are the + + align:start position:0% +a couple of the fill-ins those are the + + + align:start position:0% +a couple of the fill-ins those are the +two fill-ins in row four then when I go + + align:start position:0% +two fill-ins in row four then when I go + + + align:start position:0% +two fill-ins in row four then when I go +on to row + + align:start position:0% +on to row + + + align:start position:0% +on to row +five uh well I'll fill in there those + + align:start position:0% +five uh well I'll fill in there those + + + align:start position:0% +five uh well I'll fill in there those +are so those are the three off three low + + align:start position:0% +are so those are the three off three low + + + align:start position:0% +are so those are the three off three low +above below the diagonal and above the + + align:start position:0% +above below the diagonal and above the + + + align:start position:0% +above below the diagonal and above the +diagonal nonzeros that come from the bad + + align:start position:0% +diagonal nonzeros that come from the bad + + + align:start position:0% +diagonal nonzeros that come from the bad +ordering I think I didn't prepare that + + align:start position:0% +ordering I think I didn't prepare that + + + align:start position:0% +ordering I think I didn't prepare that +but I hope it so I hope it's right + + align:start position:0% +but I hope it so I hope it's right + + + align:start position:0% +but I hope it so I hope it's right +yeah okay now so what's minimum degree + + align:start position:0% +yeah okay now so what's minimum degree + + + align:start position:0% +yeah okay now so what's minimum degree +minimum degree is + + align:start position:0% +minimum degree is + + + align:start position:0% +minimum degree is +simply uh sort of a greedy type + + align:start position:0% +simply uh sort of a greedy type + + + align:start position:0% +simply uh sort of a greedy type +algorithm because we have no way to look + + align:start position:0% +algorithm because we have no way to look + + + align:start position:0% +algorithm because we have no way to look +far far ahead and see what what nonzeros + + align:start position:0% +far far ahead and see what what nonzeros + + + align:start position:0% +far far ahead and see what what nonzeros +are coming way way down the line so + + align:start position:0% +are coming way way down the line so + + + align:start position:0% +are coming way way down the line so +let's just take it where we + + align:start position:0% +let's just take it where we + + + align:start position:0% +let's just take it where we +are uh we have to choose what should be + + align:start position:0% +are uh we have to choose what should be + + + align:start position:0% +are uh we have to choose what should be +the next pivot so we here maybe we let's + + align:start position:0% +the next pivot so we here maybe we let's + + + align:start position:0% +the next pivot so we here maybe we let's +say we take that first pivot good + + align:start position:0% +say we take that first pivot good + + + align:start position:0% +say we take that first pivot good +it's it does it's all the all the so + + align:start position:0% +it's it does it's all the all the so + + + align:start position:0% +it's it does it's all the all the so +what are the degrees of these of these + + align:start position:0% +what are the degrees of these of these + + + align:start position:0% +what are the degrees of these of these +um let let me redraw the graph before + + align:start position:0% +um let let me redraw the graph before + + + align:start position:0% +um let let me redraw the graph before +the fill in 1 2 3 four five six so I've + + align:start position:0% +the fill in 1 2 3 four five six so I've + + + align:start position:0% +the fill in 1 2 3 four five six so I've +got six + + align:start position:0% + + + + align:start position:0% + +nodes that has degree one it's connected + + align:start position:0% +nodes that has degree one it's connected + + + align:start position:0% +nodes that has degree one it's connected +only to one other node actually all + + align:start position:0% +only to one other node actually all + + + align:start position:0% +only to one other node actually all +these have degree one and this one has + + align:start position:0% +these have degree one and this one has + + + align:start position:0% +these have degree one and this one has +degree five five edges are going out of + + align:start position:0% +degree five five edges are going out of + + + align:start position:0% +degree five five edges are going out of +it so the whole point of minimum degree + + align:start position:0% +it so the whole point of minimum degree + + + align:start position:0% +it so the whole point of minimum degree +is don't pick that one pick at each step + + align:start position:0% +is don't pick that one pick at each step + + + align:start position:0% +is don't pick that one pick at each step +create the new graph the graph expresses + + align:start position:0% +create the new graph the graph expresses + + + align:start position:0% +create the new graph the graph expresses +a fill in and we're not going to be able + + align:start position:0% +a fill in and we're not going to be able + + + align:start position:0% +a fill in and we're not going to be able +to avoid fill in some fill in normally + + align:start position:0% +to avoid fill in some fill in normally + + + align:start position:0% +to avoid fill in some fill in normally +but at every point take the graph as it + + align:start position:0% +but at every point take the graph as it + + + align:start position:0% +but at every point take the graph as it +is and choose as the next node to work + + align:start position:0% +is and choose as the next node to work + + + align:start position:0% +is and choose as the next node to work +on that means the next row to use in + + align:start position:0% +on that means the next row to use in + + + align:start position:0% +on that means the next row to use in +elimination the next pivot to choose + + align:start position:0% +elimination the next pivot to choose + + + align:start position:0% +elimination the next pivot to choose +choose choose one that has smallest + + align:start position:0% +choose choose one that has smallest + + + align:start position:0% +choose choose one that has smallest +degree don't choose this one so that the + + align:start position:0% +degree don't choose this one so that the + + + align:start position:0% +degree don't choose this one so that the +for for this very special case we could + + align:start position:0% +for for this very special case we could + + + align:start position:0% +for for this very special case we could +we have five choices for what comes + + align:start position:0% +we have five choices for what comes + + + align:start position:0% +we have five choices for what comes +first we make a choice like that one we + + align:start position:0% +first we make a choice like that one we + + + align:start position:0% +first we make a choice like that one we +do elimination in this case it doesn't + + align:start position:0% +do elimination in this case it doesn't + + + align:start position:0% +do elimination in this case it doesn't +fill in anything now I'm looking at the + + align:start position:0% +fill in anything now I'm looking at the + + + align:start position:0% +fill in anything now I'm looking at the +rest of the graph I have four nodes + + align:start position:0% +rest of the graph I have four nodes + + + align:start position:0% +rest of the graph I have four nodes +there with only degree with degree only + + align:start position:0% +there with only degree with degree only + + + align:start position:0% +there with only degree with degree only +one and a node there with high degree so + + align:start position:0% +one and a node there with high degree so + + + align:start position:0% +one and a node there with high degree so +I don't choose that so I choose two and + + align:start position:0% +I don't choose that so I choose two and + + + align:start position:0% +I don't choose that so I choose two and +so on so so of course minimum degree + + align:start position:0% +so on so so of course minimum degree + + + align:start position:0% +so on so so of course minimum degree +approximate or perfect or any dumb idea + + align:start position:0% +approximate or perfect or any dumb idea + + + align:start position:0% +approximate or perfect or any dumb idea +is going to uh create the right ordering + + align:start position:0% +is going to uh create the right ordering + + + align:start position:0% +is going to uh create the right ordering +that produces this Matrix okay so but + + align:start position:0% +that produces this Matrix okay so but + + + align:start position:0% +that produces this Matrix okay so but +hope you've seen what minimum degree is + + align:start position:0% +hope you've seen what minimum degree is + + + align:start position:0% +hope you've seen what minimum degree is +at every stage you look down the column + + align:start position:0% +at every stage you look down the column + + + align:start position:0% +at every stage you look down the column +just as here well actually what would + + align:start position:0% +just as here well actually what would + + + align:start position:0% +just as here well actually what would +what would minimum degree give here I + + align:start position:0% +what would minimum degree give here I + + + align:start position:0% +what would minimum degree give here I +would love to have a complete picture I + + align:start position:0% +would love to have a complete picture I + + + align:start position:0% +would love to have a complete picture I +think we could at least see at the start + + align:start position:0% +think we could at least see at the start + + + align:start position:0% +think we could at least see at the start +let me let me erase this red black + + align:start position:0% +let me let me erase this red black + + + align:start position:0% +let me let me erase this red black +ordering and prepare to write + + align:start position:0% +ordering and prepare to write + + + align:start position:0% +ordering and prepare to write +in um a minimum degree + + align:start position:0% + + + + align:start position:0% + +order if I can complete that recomplete + + align:start position:0% +order if I can complete that recomplete + + + align:start position:0% +order if I can complete that recomplete +that graph okay so what node do I take + + align:start position:0% +that graph okay so what node do I take + + + align:start position:0% +that graph okay so what node do I take +first + + align:start position:0% + + + + align:start position:0% + +remember the the graph really does not + + align:start position:0% +remember the the graph really does not + + + align:start position:0% +remember the the graph really does not +have these pieces I should should uh I + + align:start position:0% +have these pieces I should should uh I + + + align:start position:0% +have these pieces I should should uh I +might as well erase them now shall I + + align:start position:0% +might as well erase them now shall I + + + align:start position:0% +might as well erase them now shall I +just erase these are pieces that connect + + align:start position:0% +just erase these are pieces that connect + + + align:start position:0% +just erase these are pieces that connect +to known values that are on the right + + align:start position:0% +to known values that are on the right + + + align:start position:0% +to known values that are on the right +hand side so I think the graph doesn't + + align:start position:0% +hand side so I think the graph doesn't + + + align:start position:0% +hand side so I think the graph doesn't +have those connections those connections + + align:start position:0% +have those connections those connections + + + align:start position:0% +have those connections those connections +it's going to look pretty much as it did + + align:start position:0% +it's going to look pretty much as it did + + + align:start position:0% +it's going to look pretty much as it did +before + + align:start position:0% +before + + + align:start position:0% +before +but I think now we have the graph of + + align:start position:0% +but I think now we have the graph of + + + align:start position:0% +but I think now we have the graph of +actual + + align:start position:0% +actual + + + align:start position:0% +actual +16 the graph that we should be looking + + align:start position:0% +16 the graph that we should be looking + + + align:start position:0% +16 the graph that we should be looking +at + + align:start position:0% +at + + + align:start position:0% +at +that's the graph of our Matrix the graph + + align:start position:0% +that's the graph of our Matrix the graph + + + align:start position:0% +that's the graph of our Matrix the graph +of the nonzero structure in the Matrix + + align:start position:0% +of the nonzero structure in the Matrix + + + align:start position:0% +of the nonzero structure in the Matrix +okay so what do you take as the first + + align:start position:0% +okay so what do you take as the first + + + align:start position:0% +okay so what do you take as the first +node you take the corners right the + + align:start position:0% +node you take the corners right the + + + align:start position:0% +node you take the corners right the +corners are going to win because they + + align:start position:0% +corners are going to win because they + + + align:start position:0% +corners are going to win because they +have degree two these guys have degree + + align:start position:0% +have degree two these guys have degree + + + align:start position:0% +have degree two these guys have degree +three there's a degree two so I might + + align:start position:0% +three there's a degree two so I might + + + align:start position:0% +three there's a degree two so I might +take that or well let's see what happens + + align:start position:0% +take that or well let's see what happens + + + align:start position:0% +take that or well let's see what happens +when I take this + + align:start position:0% +when I take this + + + align:start position:0% +when I take this +one then I then I have to see okay when + + align:start position:0% +one then I then I have to see okay when + + + align:start position:0% +one then I then I have to see okay when +I use use that as the pivot exactly what + + align:start position:0% +I use use that as the pivot exactly what + + + align:start position:0% +I use use that as the pivot exactly what +I did + + align:start position:0% + + + + align:start position:0% + +here what's going to fill in well I + + align:start position:0% +here what's going to fill in well I + + + align:start position:0% +here what's going to fill in well I +guess explicitly I know that two two new + + align:start position:0% +guess explicitly I know that two two new + + + align:start position:0% +guess explicitly I know that two two new +edges fill in and what are they + + align:start position:0% +edges fill in and what are they + + + align:start position:0% +edges fill in and what are they +H well maybe they're the same I guess + + align:start position:0% +H well maybe they're the same I guess + + + align:start position:0% +H well maybe they're the same I guess +they are this is Edge number yeah so on + + align:start position:0% +they are this is Edge number yeah so on + + + align:start position:0% +they are this is Edge number yeah so on +the graph it's probably easier to see + + align:start position:0% +the graph it's probably easier to see + + + align:start position:0% +the graph it's probably easier to see +than in The Matrix what so I use this + + align:start position:0% +than in The Matrix what so I use this + + + align:start position:0% +than in The Matrix what so I use this +guy it by elimination I'm removing the + + align:start position:0% +guy it by elimination I'm removing the + + + align:start position:0% +guy it by elimination I'm removing the +connections so it's maybe sits there as + + align:start position:0% +connections so it's maybe sits there as + + + align:start position:0% +connections so it's maybe sits there as +surviving the the to remind me what + + align:start position:0% +surviving the the to remind me what + + + align:start position:0% +surviving the the to remind me what +which node was numbered one but these + + align:start position:0% +which node was numbered one but these + + + align:start position:0% +which node was numbered one but these +connections have been removed by + + align:start position:0% +connections have been removed by + + + align:start position:0% +connections have been removed by +elimination these that entry became a + + align:start position:0% +elimination these that entry became a + + + align:start position:0% +elimination these that entry became a +zero and that entry became a zero but + + align:start position:0% +zero and that entry became a zero but + + + align:start position:0% +zero and that entry became a zero but +there was a fill in here + + align:start position:0% +there was a fill in here + + + align:start position:0% +there was a fill in here +right okay that's the first step of + + align:start position:0% +right okay that's the first step of + + + align:start position:0% +right okay that's the first step of +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +degree the Second + + align:start position:0% +degree the Second + + + align:start position:0% +degree the Second +Step as you + + align:start position:0% +Step as you + + + align:start position:0% +Step as you +say it's I'm going to do all the corners + + align:start position:0% +say it's I'm going to do all the corners + + + align:start position:0% +say it's I'm going to do all the corners +first right because that has degree two + + align:start position:0% +first right because that has degree two + + + align:start position:0% +first right because that has degree two +and these still have degree three no no + + align:start position:0% +and these still have degree three no no + + + align:start position:0% +and these still have degree three no no +no improvement it's kind of fun to do + + align:start position:0% +no improvement it's kind of fun to do + + + align:start position:0% +no improvement it's kind of fun to do +these two and that filled + + align:start position:0% +these two and that filled + + + align:start position:0% +these two and that filled +in number three and that filled in + + align:start position:0% +in number three and that filled in + + + align:start position:0% +in number three and that filled in +number four and that filled + + align:start position:0% +number four and that filled + + + align:start position:0% +number four and that filled +in okay what + + align:start position:0% +in okay what + + + align:start position:0% +in okay what +next well there going to be a bunch of + + align:start position:0% +next well there going to be a bunch of + + + align:start position:0% +next well there going to be a bunch of +choices + + align:start position:0% +choices + + + align:start position:0% +choices +now and as far as I know I could be + + align:start position:0% +now and as far as I know I could be + + + align:start position:0% +now and as far as I know I could be +wrong the I I don't know whether the I + + align:start position:0% +wrong the I I don't know whether the I + + + align:start position:0% +wrong the I I don't know whether the I +don't know what the choice decision how + + align:start position:0% +don't know what the choice decision how + + + align:start position:0% +don't know what the choice decision how +the decision is made when there is a + + align:start position:0% +the decision is made when there is a + + + align:start position:0% +the decision is made when there is a +choice when I have one two 3 four five + + align:start position:0% +choice when I have one two 3 four five + + + align:start position:0% +choice when I have one two 3 four five +six seven eight nodes all with degree + + align:start position:0% +six seven eight nodes all with degree + + + align:start position:0% +six seven eight nodes all with degree +three but let me just take this one so + + align:start position:0% +three but let me just take this one so + + + align:start position:0% +three but let me just take this one so +I'll take this as the next one as number + + align:start position:0% +I'll take this as the next one as number + + + align:start position:0% +I'll take this as the next one as number +five I guess that'll be number five that + + align:start position:0% +five I guess that'll be number five that + + + align:start position:0% +five I guess that'll be number five that +will kill all those connections and just + + align:start position:0% +will kill all those connections and just + + + align:start position:0% +will kill all those connections and just +leave the node but it will put in that + + align:start position:0% +leave the node but it will put in that + + + align:start position:0% +leave the node but it will put in that +one any others maybe only that + + align:start position:0% +one any others maybe only that + + + align:start position:0% +one any others maybe only that +one did I do that + + align:start position:0% +one did I do that + + + align:start position:0% +one did I do that +right yep I think I mean it would have + + align:start position:0% +right yep I think I mean it would have + + + align:start position:0% +right yep I think I mean it would have +put in this one because those are both + + align:start position:0% +put in this one because those are both + + + align:start position:0% +put in this one because those are both +connected to this but they that edge is + + align:start position:0% +connected to this but they that edge is + + + align:start position:0% +connected to this but they that edge is +already in there so nothing + + align:start position:0% +already in there so nothing + + + align:start position:0% +already in there so nothing +new okay so actually here I've created a + + align:start position:0% +new okay so actually here I've created a + + + align:start position:0% +new okay so actually here I've created a +node with it's o degree three so I'm + + align:start position:0% +node with it's o degree three so I'm + + + align:start position:0% +node with it's o degree three so I'm +going to do I have a lot of degree 3es + + align:start position:0% +going to do I have a lot of degree 3es + + + align:start position:0% +going to do I have a lot of degree 3es +here but then after a while I think when + + align:start position:0% +here but then after a while I think when + + + align:start position:0% +here but then after a while I think when +I get into the + + align:start position:0% +I get into the + + + align:start position:0% +I get into the +center uh I'm guessing that the degree + + align:start position:0% +center uh I'm guessing that the degree + + + align:start position:0% +center uh I'm guessing that the degree +will go up I don't think I I don't think + + align:start position:0% +will go up I don't think I I don't think + + + align:start position:0% +will go up I don't think I I don't think +I get away with degree 3 all the way in + + align:start position:0% +I get away with degree 3 all the way in + + + align:start position:0% +I get away with degree 3 all the way in +until the finish I don't + + align:start position:0% +until the finish I don't + + + align:start position:0% +until the finish I don't +think anyway you you see + + align:start position:0% +think anyway you you see + + + align:start position:0% +think anyway you you see +the point that there are there are + + align:start position:0% +the point that there are there are + + + align:start position:0% +the point that there are there are +choices to make among uh equal equal + + align:start position:0% +choices to make among uh equal equal + + + align:start position:0% +choices to make among uh equal equal +nodes with equal + + align:start position:0% +nodes with equal + + + align:start position:0% +nodes with equal +degree and then there's this calculation + + align:start position:0% +degree and then there's this calculation + + + align:start position:0% +degree and then there's this calculation +to make maybe I should uh this is a + + align:start position:0% +to make maybe I should uh this is a + + + align:start position:0% +to make maybe I should uh this is a +moment to just mention if I can do it + + align:start position:0% +moment to just mention if I can do it + + + align:start position:0% +moment to just mention if I can do it +how + + align:start position:0% + + + + align:start position:0% + +uh how you might keep how you might + + align:start position:0% +uh how you might keep how you might + + + align:start position:0% +uh how you might keep how you might +organize the the + + align:start position:0% +organize the the + + + align:start position:0% +organize the the +uh this pass through so this pass + + align:start position:0% +uh this pass through so this pass + + + align:start position:0% +uh this pass through so this pass +through the Matrix is really a just a + + align:start position:0% +through the Matrix is really a just a + + + align:start position:0% +through the Matrix is really a just a +pass through the graph it's not looking + + align:start position:0% +pass through the graph it's not looking + + + align:start position:0% +pass through the graph it's not looking +at the actual numbers it's just choosing + + align:start position:0% +at the actual numbers it's just choosing + + + align:start position:0% +at the actual numbers it's just choosing +the ordering and then then the next pass + + align:start position:0% +the ordering and then then the next pass + + + align:start position:0% +the ordering and then then the next pass +through we follow that ordering with the + + align:start position:0% +through we follow that ordering with the + + + align:start position:0% +through we follow that ordering with the +numbers finding the multipliers that go + + align:start position:0% +numbers finding the multipliers that go + + + align:start position:0% +numbers finding the multipliers that go +into L and the numbers that are left in + + align:start position:0% +into L and the numbers that are left in + + + align:start position:0% +into L and the numbers that are left in +the Matrix U okay so how would + + align:start position:0% +the Matrix U okay so how would + + + align:start position:0% +the Matrix U okay so how would +I how would anybody + + align:start position:0% +I how would anybody + + + align:start position:0% +I how would anybody +reasonably write down the original list + + align:start position:0% +reasonably write down the original list + + + align:start position:0% +reasonably write down the original list +so I have the nodes numbers 1 two 3 4 up + + align:start position:0% +so I have the nodes numbers 1 two 3 4 up + + + align:start position:0% +so I have the nodes numbers 1 two 3 4 up +to + + align:start position:0% +to + + + align:start position:0% +to +16 those are the node numbers and now + + align:start position:0% +16 those are the node numbers and now + + + align:start position:0% +16 those are the node numbers and now +with node one I'll list all the so this + + align:start position:0% +with node one I'll list all the so this + + + align:start position:0% +with node one I'll list all the so this +corresponds to row one of the Matrix so + + align:start position:0% +corresponds to row one of the Matrix so + + + align:start position:0% +corresponds to row one of the Matrix so +I list all the nodes that are connected + + align:start position:0% +I list all the nodes that are connected + + + align:start position:0% +I list all the nodes that are connected +to to row one to to node one well I node + + align:start position:0% +to to row one to to node one well I node + + + align:start position:0% +to to row one to to node one well I node +one itself is I don't know whether to + + align:start position:0% +one itself is I don't know whether to + + + align:start position:0% +one itself is I don't know whether to +put that in or not maybe I will just and + + align:start position:0% +put that in or not maybe I will just and + + + align:start position:0% +put that in or not maybe I will just and +number two is connected to it and number + + align:start position:0% +number two is connected to it and number + + + align:start position:0% +number two is connected to it and number +five above it I'm taking the original + + align:start position:0% +five above it I'm taking the original + + + align:start position:0% +five above it I'm taking the original +row order + + align:start position:0% +row order + + + align:start position:0% +row order +okay and then when I look at node two so + + align:start position:0% +okay and then when I look at node two so + + + align:start position:0% +okay and then when I look at node two so +I'm just it's just going to be a long + + align:start position:0% +I'm just it's just going to be a long + + + align:start position:0% +I'm just it's just going to be a long +list but I'll have to have a break there + + align:start position:0% +list but I'll have to have a break there + + + align:start position:0% +list but I'll have to have a break there +to tell me that these were the these + + align:start position:0% +to tell me that these were the these + + + align:start position:0% +to tell me that these were the these +numbers were associated with Row + + align:start position:0% +numbers were associated with Row + + + align:start position:0% +numbers were associated with Row +one now I want to know those associated + + align:start position:0% +one now I want to know those associated + + + align:start position:0% +one now I want to know those associated +with row two so row two had the + + align:start position:0% +with row two so row two had the + + + align:start position:0% +with row two so row two had the +connection back to + + align:start position:0% +connection back to + + + align:start position:0% +connection back to +one so this little group is going to be + + align:start position:0% +one so this little group is going to be + + + align:start position:0% +one so this little group is going to be +all the things connected to row two + + align:start position:0% +all the things connected to row two + + + align:start position:0% +all the things connected to row two +remember sorry since I've erased all + + align:start position:0% +remember sorry since I've erased all + + + align:start position:0% +remember sorry since I've erased all +those connections but you remember them + + align:start position:0% +those connections but you remember them + + + align:start position:0% +those connections but you remember them +two was connected to one it's connected + + align:start position:0% +two was connected to one it's connected + + + align:start position:0% +two was connected to one it's connected +forward to three and above it to + + align:start position:0% +forward to three and above it to + + + align:start position:0% +forward to three and above it to +probably six maybe that's 1 three and + + align:start position:0% +probably six maybe that's 1 three and + + + align:start position:0% +probably six maybe that's 1 three and +six and then a slash and then whatever + + align:start position:0% +six and then a slash and then whatever + + + align:start position:0% +six and then a slash and then whatever +node three so I + + align:start position:0% +node three so I + + + align:start position:0% +node three so I +need I need I I guess I need one more + + align:start position:0% +need I need I I guess I need one more + + + align:start position:0% +need I need I I guess I need one more +line there to tell me I need a pointer I + + align:start position:0% +line there to tell me I need a pointer I + + + align:start position:0% +line there to tell me I need a pointer I +need a line of a pointer that tells me + + align:start position:0% +need a line of a pointer that tells me + + + align:start position:0% +need a line of a pointer that tells me +okay number one start with the first one + + align:start position:0% +okay number one start with the first one + + + align:start position:0% +okay number one start with the first one +one two 3 number two start with the + + align:start position:0% +one two 3 number two start with the + + + align:start position:0% +one two 3 number two start with the +fourth one number three start with the + + align:start position:0% +fourth one number three start with the + + + align:start position:0% +fourth one number three start with the +seventh one so that number seven is + + align:start position:0% +seventh one so that number seven is + + + align:start position:0% +seventh one so that number seven is +pointing to the to the beginning of + + align:start position:0% +pointing to the to the beginning of + + + align:start position:0% +pointing to the to the beginning of +the the Su list the beginning of the of + + align:start position:0% +the the Su list the beginning of the of + + + align:start position:0% +the the Su list the beginning of the of +the short list that's associated to the + + align:start position:0% +the short list that's associated to the + + + align:start position:0% +the short list that's associated to the +to each separate + + align:start position:0% +to each separate + + + align:start position:0% +to each separate +node okay and I I guess what I'm saying + + align:start position:0% +node okay and I I guess what I'm saying + + + align:start position:0% +node okay and I I guess what I'm saying +is that this is a pretty compact + + align:start position:0% +is that this is a pretty compact + + + align:start position:0% +is that this is a pretty compact +description of the graph this will tell + + align:start position:0% +description of the graph this will tell + + + align:start position:0% +description of the graph this will tell +me all the edges in the graph because it + + align:start position:0% +me all the edges in the graph because it + + + align:start position:0% +me all the edges in the graph because it +tells me what two is connected to and + + align:start position:0% +tells me what two is connected to and + + + align:start position:0% +tells me what two is connected to and +this tells me where that + + align:start position:0% +this tells me where that + + + align:start position:0% +this tells me where that +little uh set + + align:start position:0% +little uh set + + + align:start position:0% +little uh set +lies and now if + + align:start position:0% +lies and now if + + + align:start position:0% +lies and now if +I as I will change the + + align:start position:0% +I as I will change the + + + align:start position:0% +I as I will change the +ordering then I just reorganize the + + align:start position:0% +ordering then I just reorganize the + + + align:start position:0% +ordering then I just reorganize the +pointers I'm going to speak roughly and + + align:start position:0% +pointers I'm going to speak roughly and + + + align:start position:0% +pointers I'm going to speak roughly and +not the detail + + align:start position:0% +not the detail + + + align:start position:0% +not the detail +just in in general in the large you + + align:start position:0% +just in in general in the large you + + + align:start position:0% +just in in general in the large you +could imagine that this is a pretty + + align:start position:0% +could imagine that this is a pretty + + + align:start position:0% +could imagine that this is a pretty +convenient um structure to uh to use for + + align:start position:0% +convenient um structure to uh to use for + + + align:start position:0% +convenient um structure to uh to use for +the for the for keeping the record of + + align:start position:0% +the for the for keeping the record of + + + align:start position:0% +the for the for keeping the record of +what the order what what the node + + align:start position:0% +what the order what what the node + + + align:start position:0% +what the order what what the node +numbering is okay so that's and the the + + align:start position:0% +numbering is okay so that's and the the + + + align:start position:0% +numbering is okay so that's and the the +uh command nnz is a useful one that + + align:start position:0% +uh command nnz is a useful one that + + + align:start position:0% +uh command nnz is a useful one that +that's a mat command that counts the + + align:start position:0% +that's a mat command that counts the + + + align:start position:0% +that's a mat command that counts the +number of of + + align:start position:0% + + + + align:start position:0% + +nonzeros so n n and Z suggest exactly + + align:start position:0% +nonzeros so n n and Z suggest exactly + + + align:start position:0% +nonzeros so n n and Z suggest exactly +what that will do so if you pick an + + align:start position:0% +what that will do so if you pick an + + + align:start position:0% +what that will do so if you pick an +ordering like approximate minimum degree + + align:start position:0% +ordering like approximate minimum degree + + + align:start position:0% +ordering like approximate minimum degree +and you pick a matrix like this one and + + align:start position:0% +and you pick a matrix like this one and + + + align:start position:0% +and you pick a matrix like this one and +you run well I'd be very interested in + + align:start position:0% +you run well I'd be very interested in + + + align:start position:0% +you run well I'd be very interested in +that what if you run it you you take you + + align:start position:0% +that what if you run it you you take you + + + align:start position:0% +that what if you run it you you take you +take the Matrix k2d you take the + + align:start position:0% +take the Matrix k2d you take the + + + align:start position:0% +take the Matrix k2d you take the +permutation that comes from approximate + + align:start position:0% +permutation that comes from approximate + + + align:start position:0% +permutation that comes from approximate +minimum degree that gives you this + + align:start position:0% +minimum degree that gives you this + + + align:start position:0% +minimum degree that gives you this +reordered Matrix which you then factor + + align:start position:0% +reordered Matrix which you then factor + + + align:start position:0% +reordered Matrix which you then factor +into you then do elimination which + + align:start position:0% +into you then do elimination which + + + align:start position:0% +into you then do elimination which +factors it in L * U or probably L * L + + align:start position:0% +factors it in L * U or probably L * L + + + align:start position:0% +factors it in L * U or probably L * L +transpose because it's positive definite + + align:start position:0% +transpose because it's positive definite + + + align:start position:0% +transpose because it's positive definite +and then I would do an NZ + + align:start position:0% + + + + align:start position:0% + +ofl as a measure of filling + + align:start position:0% +ofl as a measure of filling + + + align:start position:0% +ofl as a measure of filling +that would count the fill in in L and + + align:start position:0% +that would count the fill in in L and + + + align:start position:0% +that would count the fill in in L and +with symmetry it would be the same in U + + align:start position:0% +with symmetry it would be the same in U + + + align:start position:0% +with symmetry it would be the same in U +and + + align:start position:0% +and + + + align:start position:0% +and +uh if you have a better idea than + + align:start position:0% +uh if you have a better idea than + + + align:start position:0% +uh if you have a better idea than +approximate minimum degree that's a + + align:start position:0% +approximate minimum degree that's a + + + align:start position:0% +approximate minimum degree that's a +measure to to try it to to to use as the + + align:start position:0% +measure to to try it to to to use as the + + + align:start position:0% +measure to to try it to to to use as the +Criterion okay uh just a little time to + + align:start position:0% +Criterion okay uh just a little time to + + + align:start position:0% +Criterion okay uh just a little time to +speak finally about this idea of graph + + align:start position:0% +speak finally about this idea of graph + + + align:start position:0% +speak finally about this idea of graph +separators so again I have to get back + + align:start position:0% +separators so again I have to get back + + + align:start position:0% +separators so again I have to get back +to a + + align:start position:0% +to a + + + align:start position:0% +to a +graph uh let me draw a graph on so now + + align:start position:0% +graph uh let me draw a graph on so now + + + align:start position:0% +graph uh let me draw a graph on so now +I'm ready for for this one I'll put a + + align:start position:0% +I'm ready for for this one I'll put a + + + align:start position:0% +I'm ready for for this one I'll put a +little star next to it to say that it + + align:start position:0% +little star next to it to say that it + + + align:start position:0% +little star next to it to say that it +didn't look for a long time as if it + + align:start position:0% +didn't look for a long time as if it + + + align:start position:0% +didn't look for a long time as if it +could compete with number + + align:start position:0% +could compete with number + + + align:start position:0% +could compete with number +two but uh because it'll be a different + + align:start position:0% + + + + align:start position:0% + +ordering you could in a way it's going + + align:start position:0% +ordering you could in a way it's going + + + align:start position:0% +ordering you could in a way it's going +to be a block minimum degree ordering + + align:start position:0% +to be a block minimum degree ordering + + + align:start position:0% +to be a block minimum degree ordering +let me let me say what it is and as I + + align:start position:0% +let me let me say what it is and as I + + + align:start position:0% +let me let me say what it is and as I +draw the graph let me say when it might + + align:start position:0% +draw the graph let me say when it might + + + align:start position:0% +draw the graph let me say when it might +win it might win when the + + align:start position:0% +win it might win when the + + + align:start position:0% +win it might win when the +when the size goes Way Up 3D in + + align:start position:0% +when the size goes Way Up 3D in + + + align:start position:0% +when the size goes Way Up 3D in +2D minimum degree is on sparse matrices + + align:start position:0% +2D minimum degree is on sparse matrices + + + align:start position:0% +2D minimum degree is on sparse matrices +is quite + + align:start position:0% +is quite + + + align:start position:0% +is quite +successful so in in two Dimensions until + + align:start position:0% +successful so in in two Dimensions until + + + align:start position:0% +successful so in in two Dimensions until +the size really gets big um you that's + + align:start position:0% +the size really gets big um you that's + + + align:start position:0% +the size really gets big um you that's +going to be fine in three dimensions + + align:start position:0% +going to be fine in three dimensions + + + align:start position:0% +going to be fine in three dimensions +well I'm still going to draw only two + + align:start position:0% +well I'm still going to draw only two + + + align:start position:0% +well I'm still going to draw only two +but in three dimensions or very very + + align:start position:0% +but in three dimensions or very very + + + align:start position:0% +but in three dimensions or very very +large + + align:start position:0% +large + + + align:start position:0% +large +matrices I want to think about this + + align:start position:0% +matrices I want to think about this + + + align:start position:0% +matrices I want to think about this +graph separator + + align:start position:0% + + + + align:start position:0% + +so let me I'll make it just so I really + + align:start position:0% +so let me I'll make it just so I really + + + align:start position:0% +so let me I'll make it just so I really +separate it perfectly let me make the + + align:start position:0% +separate it perfectly let me make the + + + align:start position:0% +separate it perfectly let me make the +number + + align:start position:0% + + + + align:start position:0% + +um yeah I so when when you look at that + + align:start position:0% +um yeah I so when when you look at that + + + align:start position:0% +um yeah I so when when you look at that +graph you might say if I look at that + + align:start position:0% +graph you might say if I look at that + + + align:start position:0% +graph you might say if I look at that +that set of nodes so a + + align:start position:0% +that set of nodes so a + + + align:start position:0% +that set of nodes so a +separator is a set of + + align:start position:0% +separator is a set of + + + align:start position:0% +separator is a set of +nodes that separates the rest of the + + align:start position:0% +nodes that separates the rest of the + + + align:start position:0% +nodes that separates the rest of the +nodes into two groups so I have a group + + align:start position:0% +nodes into two groups so I have a group + + + align:start position:0% +nodes into two groups so I have a group +of nodes p a group of nodes q and + + align:start position:0% +of nodes p a group of nodes q and + + + align:start position:0% +of nodes p a group of nodes q and +nothing no connections between p and q p + + align:start position:0% +nothing no connections between p and q p + + + align:start position:0% +nothing no connections between p and q p +is this + + align:start position:0% +is this + + + align:start position:0% +is this +part Q is a s similar part over there s + + align:start position:0% +part Q is a s similar part over there s + + + align:start position:0% +part Q is a s similar part over there s +the + + align:start position:0% +the + + + align:start position:0% +the +separator + + align:start position:0% +separator + + + align:start position:0% +separator +is the part with the with the connection + + align:start position:0% +is the part with the with the connection + + + align:start position:0% +is the part with the with the connection +so p is connected to Q only through S so + + align:start position:0% +so p is connected to Q only through S so + + + align:start position:0% +so p is connected to Q only through S so +now if I think of ordering in what order + + align:start position:0% +now if I think of ordering in what order + + + align:start position:0% +now if I think of ordering in what order +should I take the the P the Q and the + + align:start position:0% +should I take the the P the Q and the + + + align:start position:0% +should I take the the P the Q and the +S well our absolute rule + + align:start position:0% +S well our absolute rule + + + align:start position:0% +S well our absolute rule +is everything's connected to S put it + + align:start position:0% +is everything's connected to S put it + + + align:start position:0% +is everything's connected to S put it +last so you see that this is the block + + align:start position:0% +last so you see that this is the block + + + align:start position:0% +last so you see that this is the block +form of my small example here well I + + align:start position:0% +form of my small example here well I + + + align:start position:0% +form of my small example here well I +didn't particularly have a p or a q but + + align:start position:0% +didn't particularly have a p or a q but + + + align:start position:0% +didn't particularly have a p or a q but +I certainly wanted to put s less oh well + + align:start position:0% +I certainly wanted to put s less oh well + + + align:start position:0% +I certainly wanted to put s less oh well +maybe I did so maybe the separator here + + align:start position:0% +maybe I did so maybe the separator here + + + align:start position:0% +maybe I did so maybe the separator here +was uh so what's the separator well one + + align:start position:0% +was uh so what's the separator well one + + + align:start position:0% +was uh so what's the separator well one +possible separator would be like that as + + align:start position:0% +possible separator would be like that as + + + align:start position:0% +possible separator would be like that as +s p for these two nodes Q for these + + align:start position:0% +s p for these two nodes Q for these + + + align:start position:0% +s p for these two nodes Q for these +three + + align:start position:0% +three + + + align:start position:0% +three +nodes and the rule would be I haven't + + align:start position:0% +nodes and the rule would be I haven't + + + align:start position:0% +nodes and the rule would be I haven't +said what I'll do within P or within Q + + align:start position:0% +said what I'll do within P or within Q + + + align:start position:0% +said what I'll do within P or within Q +or within s but the rule would be put Q + + align:start position:0% +or within s but the rule would be put Q + + + align:start position:0% +or within s but the rule would be put Q +L and of course that was exactly the + + align:start position:0% +L and of course that was exactly the + + + align:start position:0% +L and of course that was exactly the +right thing to do and it's the we're + + align:start position:0% +right thing to do and it's the we're + + + align:start position:0% +right thing to do and it's the we're +following the same rule just blockwise + + align:start position:0% +following the same rule just blockwise + + + align:start position:0% +following the same rule just blockwise +so we have the block so so our Matrix + + align:start position:0% +so we have the block so so our Matrix + + + align:start position:0% +so we have the block so so our Matrix +what is our Matrix look like when you + + align:start position:0% +what is our Matrix look like when you + + + align:start position:0% +what is our Matrix look like when you +choose this ordering well you have + + align:start position:0% +choose this ordering well you have + + + align:start position:0% +choose this ordering well you have +whatever P whatever p is the block of + + align:start position:0% +whatever P whatever p is the block of + + + align:start position:0% +whatever P whatever p is the block of +all these P's you have the block of all + + align:start position:0% +all these P's you have the block of all + + + align:start position:0% +all these P's you have the block of all +these Q's which might be connected to + + align:start position:0% +these Q's which might be connected to + + + align:start position:0% +these Q's which might be connected to +each other and + + align:start position:0% +each other and + + + align:start position:0% +each other and +R but not to P so the main point is to + + align:start position:0% +R but not to P so the main point is to + + + align:start position:0% +R but not to P so the main point is to +have these zero blocks and then + + align:start position:0% +have these zero blocks and then + + + align:start position:0% +have these zero blocks and then +everything is connected to + + align:start position:0% +everything is connected to + + + align:start position:0% +everything is connected to +S and S is connected to itself so it's + + align:start position:0% +S and S is connected to itself so it's + + + align:start position:0% +S and S is connected to itself so it's +all you've achieved but it could be + + align:start position:0% +all you've achieved but it could be + + + align:start position:0% +all you've achieved but it could be +considered considerable is to take an + + align:start position:0% +considered considerable is to take an + + + align:start position:0% +considered considerable is to take an +ordering in which P + + align:start position:0% +ordering in which P + + + align:start position:0% +ordering in which P +was since p is not connected to q that + + align:start position:0% +was since p is not connected to q that + + + align:start position:0% +was since p is not connected to q that +produce these large zero blocks and of + + align:start position:0% +produce these large zero blocks and of + + + align:start position:0% +produce these large zero blocks and of +course they'll stay zero as elimination + + align:start position:0% +course they'll stay zero as elimination + + + align:start position:0% +course they'll stay zero as elimination +goes + + align:start position:0% +goes + + + align:start position:0% +goes +forward those those zeros there will I + + align:start position:0% +forward those those zeros there will I + + + align:start position:0% +forward those those zeros there will I +don't have to do any pivoting operations + + align:start position:0% +don't have to do any pivoting operations + + + align:start position:0% +don't have to do any pivoting operations +any row operations to make those zero + + align:start position:0% +any row operations to make those zero + + + align:start position:0% +any row operations to make those zero +they're already zero and uh so the only + + align:start position:0% +they're already zero and uh so the only + + + align:start position:0% +they're already zero and uh so the only +operations will + + align:start position:0% +operations will + + + align:start position:0% +operations will +be p on to s q on to s s onto + + align:start position:0% +be p on to s q on to s s onto + + + align:start position:0% +be p on to s q on to s s onto +itself and in many problems it's the S + + align:start position:0% +itself and in many problems it's the S + + + align:start position:0% +itself and in many problems it's the S +onto itself part so what will happen + + align:start position:0% +onto itself part so what will happen + + + align:start position:0% +onto itself part so what will happen +then when when I do elimination on this + + align:start position:0% +then when when I do elimination on this + + + align:start position:0% +then when when I do elimination on this +when I do + + align:start position:0% + + + + align:start position:0% + +elimination well I'll have whatever work + + align:start position:0% +elimination well I'll have whatever work + + + align:start position:0% +elimination well I'll have whatever work +is necessary within + + align:start position:0% +is necessary within + + + align:start position:0% +is necessary within +P so I I I'll be factoring can I call + + align:start position:0% +P so I I I'll be factoring can I call + + + align:start position:0% +P so I I I'll be factoring can I call +that P that part of the Matrix just + + align:start position:0% +that P that part of the Matrix just + + + align:start position:0% +that P that part of the Matrix just +it's an abuse of notation and this is + + align:start position:0% +it's an abuse of notation and this is + + + align:start position:0% +it's an abuse of notation and this is +the connections of s to P this is the + + align:start position:0% +the connections of s to P this is the + + + align:start position:0% +the connections of s to P this is the +connections of s to q s to itself Q to s + + align:start position:0% +connections of s to q s to itself Q to s + + + align:start position:0% +connections of s to q s to itself Q to s +p to S probably symmetric but the so + + align:start position:0% +p to S probably symmetric but the so + + + align:start position:0% +p to S probably symmetric but the so +when I do elimination I'll if if I don't + + align:start position:0% +when I do elimination I'll if if I don't + + + align:start position:0% +when I do elimination I'll if if I don't +if I accept this + + align:start position:0% +if I accept this + + + align:start position:0% +if I accept this +ordering if I accept this ordering and + + align:start position:0% +ordering if I accept this ordering and + + + align:start position:0% +ordering if I accept this ordering and +just go for it elimination will Factor P + + align:start position:0% +just go for it elimination will Factor P + + + align:start position:0% +just go for it elimination will Factor P +into Lu because it'll work up in the + + align:start position:0% +into Lu because it'll work up in the + + + align:start position:0% +into Lu because it'll work up in the +corner as always does then + + align:start position:0% +corner as always does then + + + align:start position:0% +corner as always does then +no connection here so it'll Factor Q + + align:start position:0% +no connection here so it'll Factor Q + + + align:start position:0% +no connection here so it'll Factor Q +into its own Lu and of course all that + + align:start position:0% +into its own Lu and of course all that + + + align:start position:0% +into its own Lu and of course all that +all this stuff down here will change but + + align:start position:0% +all this stuff down here will change but + + + align:start position:0% +all this stuff down here will change but +effectively the these will become zeros + + align:start position:0% +effectively the these will become zeros + + + align:start position:0% +effectively the these will become zeros +when because then then there's a serious + + align:start position:0% +when because then then there's a serious + + + align:start position:0% +when because then then there's a serious +elimination p on to S will make that + + align:start position:0% +elimination p on to S will make that + + + align:start position:0% +elimination p on to S will make that +zero P Q on to s q will make that zero + + align:start position:0% +zero P Q on to s q will make that zero + + + align:start position:0% +zero P Q on to s q will make that zero +this will be some I'll call it + + align:start position:0% +this will be some I'll call it + + + align:start position:0% +this will be some I'll call it +SSS it's some much full + + align:start position:0% +SSS it's some much full + + + align:start position:0% +SSS it's some much full +Matrix block smaller though hopefully + + align:start position:0% +Matrix block smaller though hopefully + + + align:start position:0% +Matrix block smaller though hopefully +smaller and uh but pretty full so + + align:start position:0% +smaller and uh but pretty full so + + + align:start position:0% +smaller and uh but pretty full so +actually in the graph separator nested + + align:start position:0% +actually in the graph separator nested + + + align:start position:0% +actually in the graph separator nested +dissection World often the most of the + + align:start position:0% +dissection World often the most of the + + + align:start position:0% +dissection World often the most of the +time is spent on that uh third block + + align:start position:0% +time is spent on that uh third block + + + align:start position:0% +time is spent on that uh third block +just working with it because it's it's + + align:start position:0% +just working with it because it's it's + + + align:start position:0% +just working with it because it's it's +the one that's pretty full okay so so + + align:start position:0% +the one that's pretty full okay so so + + + align:start position:0% +the one that's pretty full okay so so +how do how do graph separators work + + align:start position:0% +how do how do graph separators work + + + align:start position:0% +how do how do graph separators work +first of all you need a an algorithm + + align:start position:0% +first of all you need a an algorithm + + + align:start position:0% +first of all you need a an algorithm +that finds a + + align:start position:0% +that finds a + + + align:start position:0% +that finds a +separator and a lot of computer science + + align:start position:0% +separator and a lot of computer science + + + align:start position:0% +separator and a lot of computer science +attention has gone onto that given a + + align:start position:0% +attention has gone onto that given a + + + align:start position:0% +attention has gone onto that given a +graph cut it in half find a by a short + + align:start position:0% +graph cut it in half find a by a short + + + align:start position:0% +graph cut it in half find a by a short +we don't want more nodes in the + + align:start position:0% +we don't want more nodes in the + + + align:start position:0% +we don't want more nodes in the +separator than necessary because the + + align:start position:0% +separator than necessary because the + + + align:start position:0% +separator than necessary because the +work is going to end up there so we want + + align:start position:0% +work is going to end up there so we want + + + align:start position:0% +work is going to end up there so we want +to cut the graph pretty nearly in + + align:start position:0% +to cut the graph pretty nearly in + + + align:start position:0% +to cut the graph pretty nearly in +half by a short separator + + align:start position:0% +half by a short separator + + + align:start position:0% +half by a short separator +and then uh so that's a if we only did + + align:start position:0% +and then uh so that's a if we only did + + + align:start position:0% +and then uh so that's a if we only did +the the algorithm did this did the + + align:start position:0% +the the algorithm did this did the + + + align:start position:0% +the the algorithm did this did the +separation the cut the dissection once + + align:start position:0% +separation the cut the dissection once + + + align:start position:0% +separation the cut the dissection once +that's that's what we need but this idea + + align:start position:0% +that's that's what we need but this idea + + + align:start position:0% +that's that's what we need but this idea +of nested dissection oh you know what's + + align:start position:0% +of nested dissection oh you know what's + + + align:start position:0% +of nested dissection oh you know what's +going to come before I say it the idea + + align:start position:0% +going to come before I say it the idea + + + align:start position:0% +going to come before I say it the idea +of nested dissection will be take this + + align:start position:0% +of nested dissection will be take this + + + align:start position:0% +of nested dissection will be take this +um take the + + align:start position:0% + + + + align:start position:0% + +graph can I just draw this way without + + align:start position:0% +graph can I just draw this way without + + + align:start position:0% +graph can I just draw this way without +drawing all the Ed put cut it by a + + align:start position:0% +drawing all the Ed put cut it by a + + + align:start position:0% +drawing all the Ed put cut it by a +separator + + align:start position:0% +separator + + + align:start position:0% +separator +S1 that gives a P1 and a q1 but now + + align:start position:0% +S1 that gives a P1 and a q1 but now + + + align:start position:0% +S1 that gives a P1 and a q1 but now +what's + + align:start position:0% +what's + + + align:start position:0% +what's +coming you're going to separate P1 in + + align:start position:0% +coming you're going to separate P1 in + + + align:start position:0% +coming you're going to separate P1 in +order to do the work up in that left + + align:start position:0% +order to do the work up in that left + + + align:start position:0% +order to do the work up in that left +corner for the P + + align:start position:0% +corner for the P + + + align:start position:0% +corner for the P +Matrix that's itself a sparse Matrix so + + align:start position:0% +Matrix that's itself a sparse Matrix so + + + align:start position:0% +Matrix that's itself a sparse Matrix so +now I'll look for a separator and what + + align:start position:0% +now I'll look for a separator and what + + + align:start position:0% +now I'll look for a separator and what +separator will I choose for the left + + align:start position:0% +separator will I choose for the left + + + align:start position:0% +separator will I choose for the left +side of this + + align:start position:0% +side of this + + + align:start position:0% +side of this +graph I'll choose the horizontal Al + + align:start position:0% +graph I'll choose the horizontal Al + + + align:start position:0% +graph I'll choose the horizontal Al +separator this will be the second + + align:start position:0% +separator this will be the second + + + align:start position:0% +separator this will be the second +separator it'll separate the two bits of + + align:start position:0% +separator it'll separate the two bits of + + + align:start position:0% +separator it'll separate the two bits of +P the third separator will separate the + + align:start position:0% +P the third separator will separate the + + + align:start position:0% +P the third separator will separate the +two bits of + + align:start position:0% +two bits of + + + align:start position:0% +two bits of +Q now I have this part to work on a + + align:start position:0% +Q now I have this part to work on a + + + align:start position:0% +Q now I have this part to work on a +fourth separator will you see it's + + align:start position:0% +fourth separator will you see it's + + + align:start position:0% +fourth separator will you see it's +nested these separators become nested + + align:start position:0% +nested these separators become nested + + + align:start position:0% +nested these separators become nested +there's S5 there's S6 and so on okay I + + align:start position:0% +there's S5 there's S6 and so on okay I + + + align:start position:0% +there's S5 there's S6 and so on okay I +think everybody sees in principle what + + align:start position:0% +think everybody sees in principle what + + + align:start position:0% +think everybody sees in principle what +nested dissection should do and the + + align:start position:0% +nested dissection should do and the + + + align:start position:0% +nested dissection should do and the +question is how does it compare with + + align:start position:0% +question is how does it compare with + + + align:start position:0% +question is how does it compare with +minimum degree you see it's just like a + + align:start position:0% +minimum degree you see it's just like a + + + align:start position:0% +minimum degree you see it's just like a +different we're off on a different route + + align:start position:0% +different we're off on a different route + + + align:start position:0% +different we're off on a different route +here and uh you can compute ASM + + align:start position:0% +here and uh you can compute ASM + + + align:start position:0% +here and uh you can compute ASM +totically for large n what the what + + align:start position:0% +totically for large n what the what + + + align:start position:0% +totically for large n what the what +power of n appears there what power of n + + align:start position:0% +power of n appears there what power of n + + + align:start position:0% +power of n appears there what power of n +appears in minimum degree but I would + + align:start position:0% +appears in minimum degree but I would + + + align:start position:0% +appears in minimum degree but I would +love to know does + + align:start position:0% +love to know does + + + align:start position:0% +love to know does +the I I would be happy if + + align:start position:0% +the I I would be happy if + + + align:start position:0% +the I I would be happy if +somebody used approximate minimum degree + + align:start position:0% +somebody used approximate minimum degree + + + align:start position:0% +somebody used approximate minimum degree +on our model problem and maybe also on + + align:start position:0% +on our model problem and maybe also on + + + align:start position:0% +on our model problem and maybe also on +some other problem and uh we could see + + align:start position:0% +some other problem and uh we could see + + + align:start position:0% +some other problem and uh we could see +what U what power of n that's + + align:start position:0% +what U what power of n that's + + + align:start position:0% +what U what power of n that's +essentially what we're looking for so + + align:start position:0% +essentially what we're looking for so + + + align:start position:0% +essentially what we're looking for so +it's n to what power for fill + + align:start position:0% +it's n to what power for fill + + + align:start position:0% +it's n to what power for fill +in and for the operation count which + + align:start position:0% +in and for the operation count which + + + align:start position:0% +in and for the operation count which +which the number of flops which uh + + align:start position:0% +which the number of flops which uh + + + align:start position:0% +which the number of flops which uh +controls the the cost and the time + + align:start position:0% +controls the the cost and the time + + + align:start position:0% +controls the the cost and the time +yeah so it's what power ofan appears + + align:start position:0% +yeah so it's what power ofan appears + + + align:start position:0% +yeah so it's what power ofan appears +there and what power appears in any + + align:start position:0% +there and what power appears in any + + + align:start position:0% +there and what power appears in any +other method so that's there you have it + + align:start position:0% +other method so that's there you have it + + + align:start position:0% +other method so that's there you have it +for um direct elimination methods and + + align:start position:0% +for um direct elimination methods and + + + align:start position:0% +for um direct elimination methods and +I'll just mention the name of the guy + + align:start position:0% +I'll just mention the name of the guy + + + align:start position:0% +I'll just mention the name of the guy +he's at University of + + align:start position:0% +he's at University of + + + align:start position:0% +he's at University of +Florida and he's the one who wrote the + + align:start position:0% +Florida and he's the one who wrote the + + + align:start position:0% +Florida and he's the one who wrote the +contributed the code that MathWorks uses + + align:start position:0% +contributed the code that MathWorks uses + + + align:start position:0% +contributed the code that MathWorks uses +and has just announced a book coming on + + align:start position:0% +and has just announced a book coming on + + + align:start position:0% +and has just announced a book coming on +this + + align:start position:0% +this + + + align:start position:0% +this +exact topic + + align:start position:0% +exact topic + + + align:start position:0% +exact topic +uh to be to come later this year from + + align:start position:0% +uh to be to come later this year from + + + align:start position:0% +uh to be to come later this year from +the from cam so there will be a book + + align:start position:0% +the from cam so there will be a book + + + align:start position:0% +the from cam so there will be a book +that from the the person I take to be + + align:start position:0% +that from the the person I take to be + + + align:start position:0% +that from the the person I take to be +the leader in this uh in this + + align:start position:0% +the leader in this uh in this + + + align:start position:0% +the leader in this uh in this +algorithmic + + align:start position:0% +algorithmic + + + align:start position:0% +algorithmic +development okay and just a reminder + + align:start position:0% +development okay and just a reminder + + + align:start position:0% +development okay and just a reminder +Friday is my guest former PhD student + + align:start position:0% +Friday is my guest former PhD student + + + align:start position:0% +Friday is my guest former PhD student +who's going to speak about numerical + + align:start position:0% +who's going to speak about numerical + + + align:start position:0% +who's going to speak about numerical +methods for finance black schools + + align:start position:0% +methods for finance black schools + + + align:start position:0% +methods for finance black schools +equations and other + + align:start position:0% +equations and other + + + align:start position:0% +equations and other +problems to uh find the value of + + align:start position:0% +problems to uh find the value of + + + align:start position:0% +problems to uh find the value of +financial derivatives okay see you + + align:start position:0% +financial derivatives okay see you + + + align:start position:0% +financial derivatives okay see you +Friday \ No newline at end of file diff --git a/SemWOqUfMAY.txt b/SemWOqUfMAY.txt new file mode 100644 index 0000000000000000000000000000000000000000..fefbde7611395e678015058cb6c9d861ba8e42f6 --- /dev/null +++ b/SemWOqUfMAY.txt @@ -0,0 +1,2448 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK. + +Let's get started. + +So what I'm going to do next +is switch gears to one + +interesting compiler, which +is the StreamIt + +parallelizing compiler. + +The main idea about StreamIt +is the need for a common + +machine language. + +What we want to do normally is, +in a language, you want to + +represent common architecture +properties so you get good + +performance. + +You don't do it at a very high +level of abstraction, so you + +base a lot of cycles dealing +with the abstraction. + +But you want to abstract out +the differences between + +machines to get the portability, +otherwise you are + +going to just do + +assembly-hacking for one machine. + +Also you can't have things too +complex, because a typical + +programmer cannot deal with very +complex things that we + +ask them to do. + +C and Fortran was a really nice +common assembly language + +for imperative languages +running + +on the unicore machines. + +The problem is this type of +language is not a good common + +language for multicores, because +it doesn't deal with, + +first of all, multiple cores. + +And as you keep changing +the number of cores -- + +for example, automatic +parallelizing compilers are + +not good to basically get really +good parallelism out of + +that, even though we +talk about that. + +Still a lot of work has +to be done in there. + +So what's the correct +abstraction if you have + +multicore machines? + +The current offering, what you +guys are doing, is things like + +OpenMP, MPI type stuff. + +You are hand-hacking +the parallelism. + +Well, the issue with that. + +It's basically this explicit +parallel construct. + +It's kind of added to languages +like C -- that's + +what you're working on. + +And what this does is all these +nice properties about + +composability, malleability, +debuggability, portability -- + +all those things were kind +of out of the window. + +And this is why this +parallelizing is hard, because + +all these things makes life +very difficult for the + +programmer. + +And it's a huge additional +program burden. + +The programmer has to introduce +parallelism, + +correctness, optimization -- + +it's all left to +the programmer. + +So what the program has to do in +this kind of world -- what + +you are doing right now -- + +you have to feed all the +granularity decisions. + +If things are too small +you might get too much + +communication. + +If things are too large you +might not get good load + +balancing, and stuff like. + +And then you deal with all the +load balancing decisions. + +All those decisions are +left for you guys. + +You need to figure out what's +local, what's not. + +And if you make a wrong decision +it can cost you. + +All the synchronization, and +all the pain and suffering + +that comes from making +a wrong decision. + +Things like race conditions, +deadlocks, + +and stuff like that. + +And this, while MIT students can +hack it, you can't go and + +convince a dull programmer to +convert from writing nice + +simple Java application code +to dealing with all these + +complexities. + +So this is what kind of led to +our research for the last five + +years to do StreamIt. + +What you want to do is move a +bunch of these decisions to + +the compiler. + +Granularity, load balancing, +locality, and + +synchronization -- + +[OBSCURED] + +And in today's talk I am going +to talk to you about, after + +you write a StreamIt program +-- as Bill pointed out, the + +nice parallel properties -- how +do you actually go about + +getting this kind +of parallelism. + +So in StreamIt , in summary, it +basically has regular and + +repeating computation +in these filters. + +This is called a synchronous +data flow model, because we + +know at compile time exactly how +the data moves, how much + +each produces and consumes. + +And this has natural +parallelism, and it exposes + +exactly what's going to happen +to the compiler. + +And the compiler can do a lot +of powerful transformations, + +as yesterday I pointed out. + +The first thing is, because of +synchronous data flow, we know + +at compile time exactly who +needs to do what when. + +And that really helps +transform. + +It's not like everything happens +run-time dynamically. + +So what does that mean? + +So what that means is each +filter knows exactly how much + +to push and pop -- + +that's in a repeatable +execution. + +And so what we can do is, we +can come up to the static + +schedule that can be repeated +multiple times. + +So let me tell you a little +bit about what a static + +schedule means. + +So assume this filter pushes +two, this filter pops three + +but pushes one, that +filter pops two. + +So these are kind of rate +pushes, it's not everybody + +producing-consuming at once. + +So what's the schedule? + +So you can say -- + +OK, at the beginning it produces +two items, but I + +can't consume that because I +need three items. And then I + +do two of them, and I can +consume the first three and + +then produce one there. + +And I have two left behind. + +I do one more that, and +now I got three. + +And it consumes that +and produces that. + +And then I can fire C. So the +neat thing about this is, when + +I started there was nothing +inside any of these buffers. + +And if I ran A, A, B, A, B, C, +there's nothing inside the + +buffers again. + +So what I have is, I'm back to +the starting positioning. + +And if I repeat this millions +of times -- + +I keep the computation running +nicely without any buffers + +accumulating or anything +like that. + +So I can come up with this very +nice schedule that says + +-- here's what I have to do. + +I have to run A actually three +times, B twice, and C once, in + +this order, and if I +do that I have a + +computation that keeps running. + +And that gives me a good global +view on what can I + +parallelize, what can I load +balance, all those things. + +Because things don't change. + +One more additional thing about +StreamIt is we can look + +at more elements than +I am consuming. + +Question? + +AUDIENCE: How common is it in +your typical code that you can + +actually produce a static +schedule like that? + +PROFESSOR: In a lot of DSV +code this is very common. + +A lot of DSV code right now that +goes into hardware and + +software, they have very +common properties. + +But even things that are not +common, what has a very large + +chunk of the program has this +static property, and there are + +some few places that has +dynamic property. + +So it's like, when you write a +normal program you don't write + +a branch instruction after +every instruction. + +You have a few hundred +instructions and a branch, a + +few tens of instructions and +a branch type thing. + +So what you can think about it +is that those instructions + +without a branch can get +optimized the hell out of + +them, and then you do a +branch dynamically. + +So you can think about +it like this. + +What's the largest chunks you +can find that you don't have + +this uncertainty +until run-time? + +Then you can optimize the hell +out of it, and then you can + +deal with this run-time +issues -- + +basically branches, or control +for changes, or direct your + +rate changes at run-time. + +If we have 10-90 rule, if you +get 90% of the things are in a + +nice thing, and if you get good +performance on that -- + +hey, it has a big impact. + +So in our language you can deal +with dynamism, but our + +analysis is basically trying +to find the largest static + +chunk and analyze. + +So most of the time that +basically said we start with + +empty and end with empty. + +But the trouble is, a lot of +times we actually can look + +beyond the number of +what we consume. + +So what you have to do is kind +of do initial schedule that + +you don't start with empty, +you basically consume + +something -- you start with +something like this. + +So the next time in +something comes -- + +three things come +into this one -- + +I can actually pick four +and pop three. + +So you go through the first +thing kind of priming + +everything with the amount of +data needed, and then you go + +to the static schedule. + +This kind of gives you a feel +for what you'll get. + +This is a neat thing, +I know exactly + +what's going on in here. + +So now how do I run +this parallelism? + +This is something actually +Rodric pointed out before, + +there are three types of +parallelism we can deal with. + +So here's my stream program in +here, and I do some filters, + +scatter-gather in here. + +The first site of parallelism +is task parallelism. + +What that means is the +programmer said, there are + +three things that can +run parallelly + +before I join them together. + +So this is a +programmer-specified + +parallelism. + +And you have a nice data +parallel messenger + +presentation. + +The second part is +data parallelism. + +What that means is, you have +some of these things that + +don't depend on the previous +run of that one. + +So there's no invocation, +dependency across multiple + +invocations. + +These are called stateless +filters, there's no state that + +keeps changing. + +If the state kept changing, +you had to wait till the + +previous one finishes +to run the next one. + +So if you have a stateless +filter -- + +assume that it's data +parallel -- + +what you can do is you can +basically take that, replicate + +it many, many times, and +when the data comes -- + +parallel is in it +every data -- + +and it will compute and +parallelly get out here. + +The final thing is pipeline +parallelism. + +So you can feed this one into +this one, this one into this + +one, and then douse across +in a pipeline fashion. + +And you can get multiple +things execution. + +So we have these three types +of parallelism in here, and + +the interesting thing is if you +have stateful filters, you + +can't run this data parallel. + +Actually the only parallelism +you can get is pipeline + +parallelism. + +So traditionally task +parallelism is fork/join + +parallelism, that you guys +are doing right now. + +Data parallelism is +loop parallelism. + +And pipeline parallelism mainly +was done in hardware. + +If you have done something like +Verilog or VHDL you'll do + +a lot of pipeline parallelism. + +So kind of combining these three +ideas from different + +communities all into one, +because I think programs can + +have each part in there. + +So now, how do you go +and exploit this? + +How do you go take advantage +of that? + +So I'll talk a little bit of +baseline techniques, and then + +talk about what StreamIt +compiler does today. + +So assume I have a program +like this. + +The hardest thing is there +are two tasks in here. + +The programs are given, you +don't have to worry anything + +about that. + +And what you can do is assign +them into different + +cores and run it. + +Neat. + +You can think what a fork /join +parallelism is, you come + +here you fork, you do this +thing, and you join in here. + +So the interesting thing is +if you have two cores. + +You probably got a 2x +speedup in this one. + +This is really neat because +there are two things in here. + +The problem is, how about if you +have a lot more different + +number of cores? + +Or if the next generation has +double the number of cores, + +and I'm stuck with the program +you've written for the current + +generation? + +So this not that great, +interesting. + +So we ran it on the Raw +processor we have -- it has 16 + +cores in there -- + +that we have been building, and +this is actually running a + +simulator of that. + +What you find is, is a bunch of +StreamIt programs we have + +we kind of get performance like +basically close to two, + +because that's the kind of + +parallelism people have written. + +In fact, some programs even +slowed down in there, because + +what happens in here is +the parallelism and + +synchronization is not matched +with the target -- + +because it's matched +with the program. + +Because you wrote a program +because your parallelism in + +there was what you thought was +right for the algorithm. + +We didn't want you to give any +consideration to the machine + +you are running, and it didn't +match the machine, basically, + +if you just got the +parallelism. + +And you just don't +do that right. + +So one thing we have noticed +for a lot of streaming + +programs, to answer your +question, is there are a lot + +of data parallelism. + +In fact, in this filter -- + +in this program -- + +what you can do is you can find +data parallel filters, + +and parallelize them. + +So you can take each +filter, run it on + +every core for awile. + +Get the data back. + +Go to the next filter, +write on every + +go-while, get that back. + +So what you can do is, if you +have four cores in here, you + +can each replicate all +this four times. + +Run these four for a while, +and then these four, these + +four, these four, these four. + +OK? + +So that's the nice +way to do that. + +So the nice thing about doing +that is you have a lot of nice + +in the load balancing, because +each are doing the same amount + +of work for a while. + +And after it accumulates enough +data you go to the next + +one, do for a while, +and then like that. + +And each group basically will +occupy the entire machine -- + +you just go down this +group like that. + +And so we ran it, it started +even slower. + +Why? + +It should have a lot more +parallelism, because all those + +filters were data-parallel. + +So you sort of gettting stuck +with two, now we can easily + +run a parallelism of 16, because +data parallelism you + +can just put it any +amount in there. + +But we are running slow. + +AUDIENCE: Communication +overhead? + +PROFESSOR: Yeah, it could +mainly be communication + +overhead, because what happens +is you run this for a small + +amount of time. + +You had to send it all over +the place, collect it back + +again, send it all over the +place, collect it back again. + +The problem is there's too +much synchronization and + +communication. + +Because every person at the +end is like this global + +barrier, and the data has +to go shuffling around. + +And that doesn't help. + +So the other part, what you can +do in the baseline is what + +you call hardware pipeline. + +What that means is you can +actually do pipeline + +parallelism. + +The way you can do that is you +can look at the amount of work + +each filters contain, and you +can combine them together in a + +way that the number of filters +is going to be just about the + +number of tiles available. + +Most programs have +more filters than + +the number of cores. + +So you review combined filters, +to give us a number + +of filters, is just either the +same, or one or two less than + +the number of cores available. + +In a way that you combine them +so each of them will probably + +have close to the same +amount of work. + +The problem is if when you +combine it's very hard to get + +the same amount of work. + +And if you assume eight cores, +you can do this combination + +and we can say -- + +aha, if I do this combination, +I have one, two, three, four, + +five, six, seven. + +Eight cores, I can get +seven of them. + +Hopefully each of them have the +same amount of work, and I + +can run that. + +And then we assign this to one +filter and say -- "You own + +this one, you run it forever. + +You get the data from the guy +who owns this one, and you + +produce at this one." And if +you have more cores you can + +actually keep doing +some of that. + +If you have enough filters +you can each + +combine them and do that. + +So we perform, and +we got this. + +Not that bad. + +So what might be the +problems here? + +AUDIENCE: Hardware locality. + +You want to make sure that the +communicating filters are + +close to each other. + +PROFESSOR: Yeah, that +we can deal with. + +It's not a big locality +[OBSCURED] + +What's the other problem? + +The bigger problem. + +AUDIENCE: [NOISE] + +load balance. + +PROFESSOR: Load balance is the +biggest problem, because the + +problem is you are combining +different types of things + +together, and you are hoping +that each chunk you get + +combined togeher will +have an almost + +identical amount of work. + +And that's very hard to achieve +most of the time, + +because dynamically things +keep changing. + +The nice thing about loops is, +most of the time if you have a + +loop or state if you replicate +it many times, it's the same + +amount of code, same +amount of work. + +It nicely balances out. + +Hardware -- + +combining different things +becomes actually much harder. + +So again, parallelism and +synchronization are not really + +matched to the target. + +So the StreamIt compiler right +now does two, three things. + +I'll go through details. + +Coarsen the granularity +of things. + +So what happens is if you have +small filters it combines them + +together to get the large +stateless areas. + +It data parallelizes +when possible. + +And it does software pipelining, +that's a pipeline + +parallelism. + +I'll go through all these +things in detail. + +And you can get about +11x's speedup by + +doing all those things. + +So coarsen the stream graph. + +So you look at this stream +graph and say -- wait a + +minute, I have a bunch of +data-parallel parts. + +And before what I did was I take +each data-parallel part, + +when 16 then came or get +together, went 16 came + +together, went 16. + +Why? + +I have put too much +communication. + +Can I combine data-parallel +things into one gigantic unit + +when possible? + +Of course, you don't want to +combine a data-parallel part + +with a non-data-parallel part. + +Then the entire thing +becomes sequential, + +and that's not helpful. + +So in here what we found is +these four cannot be combined, + +because if you combime them +the entire thing becomes + +sequential. + +So what we have to do is, you +can combine this way. + +So all those things are +data-parallel, all those + +things are data-parallel. + +And even though they are +data-parallel if you combine + +them they become +non-data-parallel, because + +this is actually doing peeking, +it's looking at more + +than one, and so it's +looking at somebody + +else's iteration work. + +So you can't combine them. + +So what the benefits of doing +this is you reduce global + +communication basically. + +And the next thing +is you want data + +parallelizing to four cores. + +And this one fits four +ways in there. + +But the interesting thing is, +when you go in this one you + +realize there's some +task parallelism. + +We know there are two tasks that +have the same amount of + +work in here. + +So facing this four ways, and +facing this four ways, and + +giving the entire machine to +this one, and giving the + +entire machine to this one, +might not be the best idea. + +What you want to do is you +want to face it two ways. + +And then basically give the +entire machine to all of these + +running at the same time, +because they're + +load balanced -- + +because they are the same +thing repeated. + +And you can do the same +thing in here. + +OK. + +So that's what the compiler +does automatically, and it + +preserves task parallelism. + +So if you are task parallelism +you don't need -- + +the thing about that is the +parallelism you need, you + +don't need too much +parallelism. + +You need enough parallelism +to make the machine happy. + +If you have too much parallelism +you end up in + +other problems, like +synchronization. + +So this gives enough parallelism +to keep the entire + +machine happy, but +not too much. + +And by doing that actually we +get pretty good performance. + +There are a few cases where this +hardware parallelism wins + +out, these two, but +most of them -- + +actually this last one +we can recover -- + +do it pretty well. + +OK. + +So what's left here is -- so +this is good parallelism and + +low synchronization. + +But there's one thing, when you +are doing data parallelism + +there are places where there +are filters that cannot be + +parallelized -- they are +stateful filters. + +Because you can't run the data +parallelism, and according to + +Amdahl's Law that's actually +going to basically kill you, + +because that's just waiting +there and you + +can't do too much. + +I'm going to show that using +this separate program -- so + +this number is the amount +of work that each + +of them has to do. + +So this is actually a lot of +work, a lot of work -- this + +does a little work in each +of these filters. + +So if you look at that, these +are data parallel but it + +doesn't do any much work. + +Just parallelizing this +doesn't help you. + +And these are data parallel. + +And these actually +do enough work. + +Actually we can go and say I +am replicating this four + +times, and I'm OK. + +I'm getting actually good +performance in here. + +Now what we have is a +program like this. + +And so if you are not doing +anything else that we have + +data parallelism in. + +So what happens in the first +cycle you run these two. + +And then you run data parallel +this one, and then you run + +these, and then you run data +parallel this one. + +And if you look at that, what +happens is we have a bunch of + +holes in here. + +Because at that point when you +are running that part of the + +program there's not enough +parallelism, and you only have + +two things in there. + +And when you're running this +you can run this task + +parallelism in here, but there's +nothing else you can + +do in here. + +And so you get basically +21 time steps each -- + +time minutes basically will +run into that program. + +But here we can do better. + +What we can do is we can take +and try to move that there, + +and kind of compress them. + +But the interesting thing +is these things + +are not data parallel. + +So how do I do that? + +So the way to do that is taking +advantage of pipeline + +parallelism. + +So what you can do is you can +take this filter in here. + +Since each of the entire graph +can run only sequentially -- + +this has to run after this -- +you can look at the filters + +running separately like that, +and kind of say, instead of + +running this and this and this, +why don't I run this + +iterations of this one. + +This iterations of +this invocation. + +And this interations +of this one. + +And this iterations +on the next one. + +And I'm still maintaining -- +because when I'm running this + +even though the -- + +I'm not running anything data +parallel here because these + +ones were already done +previously, so I can actually + +use that value. + +And so I can maintain that +dependency, but I'm running + +things from the different +iterations. + +And so what I need to do is, I +need to kind of do a prologue + +to kind of set everything +up in there. + +And then I can do that and +I don't have any kind of + +dependence among these things. + +So now what I can do is I can +basically take thes two and + +basically lay out anything +anywhere in those groups, + +because they are in different +iterations and since I am + +pipelining these I don't have +any dependence in there. + +So I end up in this kind of a +thing, and basically much + +compress in here. + +And by doing that what you +actually get is a really nice + +performance. + +The only place that this +actually wins -- hardware + +pipelining, and this little +bit in there. + +But the rest you get a really +good win in here. + +OK. + +So what this does is basically +now we got a program that when + +the programmer never thought +anything about what the + +hardware is -- + +just wrote abstract graph +and data streaming. + +And given Raw, we automatically +actually mapped + +into it, and figured out what +is the right balance, right + +communication, right +synchronization, and got + +really good performance. + +And you're getting something +like 11x performance. + +If you do hard hand, if you work +hard probably you can do + +a little bit better. + +But this is good, because you +don't hand-do anything. + +The killer thing is now I can +probably take this set of + +programs -- which we are +actually working on -- is you + +can take them to Cell which has, +depending on the day, six + +cores, seven cores, eight cores, +and we can basically + +get to matching the number +of cores in there. + +So this is it because right now +what happens is you have + +to basically hand code all those +things, and this can + +automate all that process. + +So that's the idea, is can you +do this -- which we haven't + +really proved and this +is our research -- + +write once, use anywhere. + +So write this program once +in this abstract way. + +You have to really don't think +about full parallelism. + +You have to think about some +amount of parallelism, how + +this can be put into a stream +graph, but you are not dealing + +with synchronization, load +balancing, performance. + +You don't have to +deal with that. + +And then the compiler will +automatically do all these + +things behind you, and get +really good performance. + +And the reason I showed +this was -- + +I'll just play one more +slide I think -- + +showed this was it's +not a simple thing. + +The compiler actually has to do +a bunch of work, the work + +that you used to do before. + +Things like figuring out what's +the right granularity, + +what's the right mix of +operations, what type of + +transformations you need +to do to get there. + +But at some point we did three +things -- coarse-grained, data + +parallel, and software +pipelining. + +And by doing these three we can +actually get a really good + +performance in most of the +programs we have. So what we + +are hoping is basically this +kind of techniques can in fact + +help programmers to get +multicore performance without + +really going and dealing in the +grunge level of details + +you guys do. + +You guys will appreciate that, +and hopefully will + +think of making -- + +because now at the end of this +class, you will know all the + +pain and suffering the +programmers go + +through to get there. + +And the interesting thing would +be to in fact look at + +the ways to basically reduce +that pain and suffering. + +So that's what I have today. + +So this was, as I promised, +a short lecture -- + +the second one. + +Any questions? + +AUDIENCE: So if we've got enough +data parallelism we'll + +have the same software pipeline +jumping on each tile? + +Is that right? + +PROFESSOR: Yes. + +AUDIENCE: OK. + +So if you do that how does it +scale up to something that has + +higher communication +costs than Raw? + +By doing this software +pipelining you have to do all + +of your communication +off tile. + +PROFESSOR: So the interest in +there right now is we haven't + +done any kind of hardware +pipelining. + +We are kind of doing -- +everybody's getting a lot of + +data moving in there. + +The neat thing about right now +is, even with the SP in Cell + +and even Raw, the number of +tiles are still small enough + +that a lot of communication +-- unless way too much + +communication -- it doesn't +really overwhelm you. + +Because everybody's nearby, +you can send things. + +They talk a little bit about in +Cell that near enableness + +helps, but not that much. + +But as we go into larger and +larger cores, it's going to + +become an issue. + +Near enables become much easier +to communicate, and you + +can't do global things +in there. + +And at that point you will +actually have to do some + +hardware pipelining. + +You can't just assume that at +some point everybody's going + +to get some data and +go to something. + +So what you need to do is have +different chunks that the only + +communication that would be +between these chunks would be + +kind of a pipeline +communication. + +So you don't mix data around. + +So as we go into larger and +larger cores you need to start + +doing techniques like that. + +The interesting thing here is +even though what you had to + +change was the compiler -- +hopefully the program stays + +the same -- + +right now it's not an easy +issue, because our compiler + +has 10 times more core than the +program, so it's easier in + +the program. + +But if you look at something C, +the core base is millions + +of times larger than the +size of the compiler. + +So at some point they'll +be switched. + +It's easier to change +the compiler to kind + +of keep up to date. + +That's what happened in C. Every +generation you change + +the compiler, you don't ask +programmers where to code the + +application. + +So can you make these kind of +things as the multicores + +become different -- + +bigger, have different +features. + +You change the compiler to get +the performance, but have the + +same code base. + +That's the goal for +portability. + +AUDIENCE: Have you tried +applying StreamIt or the + +streaming model in general, to +codes that are not not very + +clearly stream-based but using +the streaming model to make + +communication explicit, such +as scientific codes. + +Or, for example, the kinds of +parallelizable loops that you + +covered in the first half +of the lecture. + +PROFESSOR: Some of those things, +when you have free + +form simple communication +can map into streaming. + +So for example, one thing +we are doing is things + +like right now MPEG. + +Some part of the MPEG is nicely +StreamIt, but when you + +actually go inside the MPEG and +dealing with the frame, + +it's basically a big array, +and you're doing that. + +So how do you chunkify the +arrays, and basically deal + +with it in a streaming order? + +There's some interesting +things you can do. + +There will be some stuff +that doesn't fit that. + +Things like pattern recognition +type stuff, where + +what you want to do +is you want to -- + +assume you're trying to -- + +good example. + +You're trying to feature +a condition in a video. + +And what happens is the number +of features, can you match or + +connect two features, +or match and + +connect a thousand features. + +And then each feature you need +to do some processing. + +And that is a very +dynamic thing. + +And that doesn't +really fit into + +streaming order right now. + +And so the interesting thing is, +the problem we have been + +doing is we are trying to +fit everything into one. + +So right now the object-oriented +model is it + +basically -- everything +has to fit in there. + +But what you're finding is there +are many things that + +don't really fit nicely. + +And you'll do these very crazy +looking things just to get + +every program to fit into the +object-oriented model. + +That doesn't really work. + +I think the right way +to work is, is there + +might be multiple models. + +There's a streaming model, +there's some kind of a + +threaded model, there might +be different ones -- + +I don't know what other +models are. + +So the key thing is your program +might have a large + +chunky model, another +chunky model. + +Don't try to come up with -- + +right now what we have +is we have a kitchen + +sink type of language. + +It tries to support everything +at the same time. + +And that doesn't really work +because then you have to think + +about and say -- + +OK done, can I have +a pointer here? + +And I need to think about all +the possible models kind of + +colliding in the same space. + +AUDIENCE: On the other hand, the +object-oriented model is + +much more generalized to me. + +It's not the best model for +many things, but it's much + +more generalizable +than some models. + +And having a single model cuts +down on the number of semantic + +barriers you have to cross -- + +PROFESSOR: I don't know but -- + +AUDIENCE: Semantic barriers +incur both programmer overhead + +and run-time overhead. + +PROFESSOR: See the problem with +right now with all the + +semantic barriers, is +object-oriented model plus a + +huge number of libraries. + +If you want to do OpenGL, it's +object-oriented but you have + +no library. + +If you want to do something +else, you have + +to learn the library. + +What the right thing would be, +instead of trying to learn the + +libraries is learn kind +of a subset language. + +So you have nice semantics, you +have nice syntax in there, + +you have nice error +checking, nice + +optimization within that syntax. + +Because the trouble is right now +everything is in this just + +gigantic language, and you +can't do anything. + +And in the program you don't +even know, because you can mix + +and match in really bad ways. + +The mix and match gives you +a lot of power, but it can + +actually really hurt. + +And a lot of people +don't need it. + +Like for example in C, people +doubt it was really crucial + +for you to access any part of +memory anywhere you want. + +You just can go and just access +any program, anywhere, + +anytime in there. + +If you look at it, nobody +takes advantage of that. + +How many times do you write the +program an say -- "Hey, I + +want to go access the other +guy's stack from this part." + +That doesn't work. + +You have a variable and +you use a variable. + +AUDIENCE: It still [OBSCURED] + +PROFESSOR: Yeah, but the thing +is because of that power, it + +creates a lot of problems +for a compiler -- + +because it needs to prove +that you're not doing + +that, which is hard. + +And also, if you make a mistake +the program is like -- + +"Yeah, this looks like right. + +It still matches my semantics +and syntax, I'll let you do + +that." But what you realize is +that's not something people do + +-- just stick with +your variable. + +And if you don't go +to variables -- + +that's what type-safe languages +do -- it's probably + +more for bugs than a feature. + +And the same kind of thing +having efficiency in language, + +is you can do everything +at the same time. + +Why can't you have a language +that you can go with this kind + +of context. + +I'm in the streaming +context now. + +I say this is my streaming +context. + +I am in a threaded context. + +Then what that does is, I have +to learn the full set of + +features, but I restrict +what I'm using here. + +That can probably realistically +improve your + +program building, because you +don't have to worry about -- + +AUDIENCE: It gives the +programmer time to get to know + +each language. + +PROFESSOR: But right now +you have to do that. + +If you look at C# it has +all these features. + +It has streaming features, it +has threaded features, it has + +every possible object-oriented +feature. + +AUDIENCE: Right, but there's a +compact central model which + +covers most things. + +You can pull in additional +features and fit them + +[OBSCURED]. + +You can do pointer manipulation +in C#, but you + +bracket things into +an unsafe block. + +And then the compiler knows +in there you're + +doing really bad things. + +PROFESSOR: That's a nice +thing, because + +you can have unsafe. + +But can you have something +like -- this is + +my streaming part. + +OK. + +Can I do something like +that, so I don't have + +to worry about other? + +The key thing is, is there a +way where -- because right + +now, my feeling is if you look +at the object-oriented part. + +So if you are doing, for +example, Windows programming, + +you can spend about a week +and learn all the + +object-oriented concepts. + +And you have to spend probably +a year to learn all the + +libraries on top of that. + +That's the old action +these days. + +It's basically the building +blocks have become too low, + +and then everything else is kind +of an unorganized mess on + +top of that. + +Can you put more abstraction +things that easy? + +Hey, I'm talking about +research, this is + +one possible angle. + +I mean there might -- you can +think, I know there are messes + +that I think in there. + +My feeling is what we do well +is when things get too + +complicated we build +abstraction layers. + +And the interesting thing there +is, we build this high + +level programming language +abstraction layer. + +And then now we have built so +much crud on top of that + +without any nice abstraction +layers, I think it's probably + +time to think through what +there could be at the + +abstraction level. + +Things like, it's hitting -- + +that is where parallelism +is really hitting. + +Because that layer, the +object-oriented layer, doesn't + +really support that well. + +And it's all kind of ad +hoc on top of that. + +And so that says something. + +Yes, it's usable. + +We had this argument -- + +assembly languages programmers +-- for two decades. + +There are people who were + +swearing by assembly languages. + +They could write it two times +smaller, two times faster than + +anything you can write in +high level language. + +It's probably still +true today. + +But at the end there were +things that high level + +languages won out. + +I think we are probably in +another layer like that. + +I don't know, probably will +go with that argument. + +You can always point to +something saying this is + +something you cannot do. + +If there are still things -- +like structured programs and + +unstructured programs, +we talked about that. + +That argument went +for a decade. + +AUDIENCE: The question I would +pose is can you formulate a + +kitchen sink language at a +parallelizable level of + +abstraction? + +PROFESSOR: Ah. + +That's interesting, because +parallelization is -- one of + +the biggest things people +have to figure out is + +composability. + +You can't have two parallel +regions as a + +black box put together. + +You start running into deadlocks +and all those other + +issues in there. + +Most of the things that you work +is the abstraction works, + +because then you can compose at +a higher level abstraction. + +You can have interface and +say -- here are something + +interface, I don't know what's +underneath, I compose at the + +interface level. + +And then the next guy composes +at the higher level, and + +everything is hidden. + +We don't know how to do that +in parallelism right now. + +We need to combine two things, +it runs into problems. And the + +minute you figure that one out +-- if somebody can figure out + +what's the right abstraction +that is composable, parallel + +abstraction -- + +I think that will solve a +huge amount of problems. + +AUDIENCE: Isn't it Fortress that +attempted to do something + +that's parallelizable and the +kitchen sink, but that then + +leaves all the parallelizable +-- + +AUDIENCE: I'm saying how +terrible [OBSCURED] + +programmers. + +PROFESSOR: But I would say right +now is a very exciting + +time, because there's +a big problem and + +nobody knows the solution. + +And I think for industry they +lose a lot of sleep over that, + +but for academia it's +the best time. + +Because we don't care, we don't +have to make money out + +of these things, we don't have +to get production out of it. + +But these actually have a very +open problem that a lot of + +people care about. + +And I think this is fun partly +because of that. + +I think this huge open problem +that if you talk to people + +like Intels and Microsoft, a +lot of people worry a lot + +about they don't know how to +deal with the future in 5-10 + +years time. + +They don't see this is scaling +what they're doing. + +And from Intel's point of +view, they made money by + +making Moore's Law available +for people to use. + +They know how to make it +available, but they don't know + +how to make people use it. + +From Microsoft's point of +view, their current + +development methodology is +almost at this breaking point. + +And if you look at the last +time this happening -- so + +things like Windows 3.0, where +their current development + +methodology doesn't really +scale, and they really + +revamped it. + +They came up with all this +process, and that had + +lasted until now. + +For the last two Office and +Vista, just realized they + +can't really scale that up. + +So they are already in trouble, +because they can't + +write the next big goal is just +two times bigger than + +Vista, and hopefully +get it working. + +But on top of that, they have +it thrown this multicore + +thing, and that really puts +huge amount of burden. + +So they are worried +about that. + +So from both their point of +view, everybody's clamoring + +for a solution. + +And things like last +time around -- + +I'll talk about this in the +future -- last time around + +when that happened, it created +a huge amount of + +opportunities, and bunch of +people who sold it kind of + +became famous. + +Becuase they say -- we came up +with a solution, and that + +people started using and +stuff like that. + +Right now, everybody's kind of +waiting for somebody to come + +up and say here's the solution, +here's a solution. + +And there are a lot of -- + +Fortress type exports is one, +and what we are doing is one. + +And hopefully some of you will +end up doing something + +interesting that +might solve it. + +This is why it's fun. + +I think we haven't had this much +of an interesting time in + +programming languages, +parallelism, architecture in + +the last two decades. + +With that, I'll stop my talk. \ No newline at end of file diff --git a/SsCeVABM4Mo.txt b/SsCeVABM4Mo.txt new file mode 100644 index 0000000000000000000000000000000000000000..6dfd3eccead51a238873a3658bd3cfc0f6dc7520 --- /dev/null +++ b/SsCeVABM4Mo.txt @@ -0,0 +1,5092 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Any questions +from last lecture + +from before spring break? + +No questions, nothing? + +Nothing at all? + +We you all still on vacation? + +Thank you. + +Yeah. + +AUDIENCE: Could you talk +about coherence states? + +PROFESSOR: Ah. + +OK, well, that's +a great question. + +So coherence states-- +actually, how many people + +have looked at the +optional problems? + +Nice, OK, good. + +Good, so coherence +states were a topic + +that we touched on +the problem sets + +and on the optional problems, +and the optional problems + +are mostly on the harmonic +oscillator and nice problems + +revealing some of the structure +of the harmonic oscillator, + +and it generalizes quite boldly. + +But here's the basic +idea of coherence states. + +Let me just talk you +through the basic ideas + +rather than do any calculations. + +So what's the ground state +of a harmonic oscillator? + +What does its wave +function look like? + +AUDIENCE: Gaussian. + +PROFESSOR: It's a +Gaussian, exactly. + +It's minimum +uncertainty wave packet. + +How does it evolve in time? + +AUDIENCE: Phase. + +PROFESSOR: Yeah, phase. + +It's an energy eigenstate, +it's the ground state, + +so it just evolves in +time with the phase. + +So if we look at the wave +function for the ground + +state, phi naught, it's +something like e to the minus x + +squared over 2a squared with +some normalization coefficient, + +which I'm not going +to worry about. + +So this is a minimal +uncertainty wave packet. + +Its position distribution +is time independent, + +because it's a +stationary statement. + +It's momentum distribution, +which is also a Gaussian, + +the Fourier transform, +is time independent. + +And so this thing up to its +rotation by the overall phase + +just sits there and +remains a Gaussian. + +Now, here's a question. + +Suppose I take my harmonic +oscillator potential, + +and I take my Gaussian, but +I displace it a little bit. + +It's the same ground +state, it's the same state + +but I've just displaced +it over a little. + +What do you expect to happen? + +How will this state +evolve in time? + +So, we know how to +solve that problem. + +We take this state, it's a +known wave function at time 0. + +We expand it in the basis +of energy eigenstates, + +each energy eigenstate +evolves in time with a phase, + +so we put in that +phase and redo the sum, + +and recover the time +evolution of the full state. + +And we've done this a number +of time on the problem sets. + +Yeah. + +AUDIENCE: Would the Gaussian, +the displaced Gaussian + +evolve the same +way, keep its width, + +if it had any +other initial width + +other than the one +of the ground state? + +PROFESSOR: Let me +come back to that, + +because it's a little more +of a precise question. + +So we know how to solve +this problem practically, + +algorithmically. + +But here's a nice fact. + +I'm not going to derive +any equations, that's + +part of the point of +the optional problems, + +but here's a nice +fact about this state. + +So it's clearly a minimum +uncertainty wave packet + +because at time 0, +because it's just + +the same Gaussian just +translated over a little bit. + +So what we'd expect, +naively, from solving + +is we expand this +in Fourier modes + +and then we let this the +system evolve in time. + +We let each individual +Fourier mode-- + +or, sorry, Fourier mode-- we +let each individual energy + +eigenstate evolve in time, pick +up a phase, and now what we get + +is a superposition. + +Instead of sum over +n at time 0, we'd + +have sum over n cn phi n of x. + +Now, as a function of time, +we get e minus I omega nt, + +and these phases are going +to change the interference + +from summing up all +these energy eigenstates, + +and so the system +will change in time. + +Because the way that the various +terms in the superposition + +interfere will change in time. + +So very naively, what you +might expect, if you just + +took a random +function-- for example, + +if I took a harmonic +oscillator potential + +and I took some stupid function +that did something like this. + +What would you expect +it to do over time? + +Well, due to all the complicated +interference effects, + +you'd expect this to turn +into, basically, some schmutz. + +Just some crazy +interference pattern. + +The thing that's nice +about a coherent state, + +and this is where +it gets its name, + +is the way that all of +these interference effects + +conspire together to evolve +the state is to leave it + +a Gaussian that does nothing +but translates in time. + +A coherent state is coherent +because it remains coherently + +a Gaussian as it moves along. + +It oscillates back and forth. + +And in fact, the peak, the +center of this Gaussian wave + +packet, oscillates with +precisely the frequency + +of the trap. + +It behaves just as a classical +particle would have had you + +displaced it from the center of +the harmonic oscillator trap, + +it oscillates back and forth. + +Now, on the other hand, +you know that its momentum + +is changing in time, right. + +And at any given +point, as you've + +shown on the problem set +that's due tomorrow-- + +or you will have shown-- at +any given moment in time, + +the momentum can be understood +as the overall phase. + +You could just change that +momentum by the overall phase, + +so it's the spatial rate +of change of the phase, e + +to the ikx. + +So you know that the way the +phase depends on position + +is changing over time. + +So it can't be quite so simple +that the wave function, rather + +than the probability +distribution, + +is remaining a +Gaussian over time. + +It's not, it's got all +sorts of complicated phases. + +But the upshot is that the +probability distribution + +oscillates back and forth +perfectly coherently. + +So that seems a little +magical, and there's a nice way + +to understand how +that magic arises, + +and it's to understand +the following. + +If I take a state, phi 0, but +I translate it x minus x0. + +OK. + +So we know that this +state, phi 0 of x, + +was the ground +state, what does it + +mean to be the ground state +of the harmonic oscillator? + +How do I check if +I'm the ground state + +of the harmonic oscillator? + +Look, I walk up to +you, I'm like, hey, + +I'm the ground state of +the harmonic oscillator. + +You're suspicious. + +What do you do? + +AUDIENCE: Annihilate. + +PROFESSOR: Annihilate. + +Exactly. + +You act with the +annihilation operator. + +Curse you. + +So you act with the annihilation +operator and you get 0, right. + +What happens if I act with the +annihilation operator on this? + +Is this the ground state? + +No, it's been displaced by x0. + +And meanwhile, I told you that +it oscillates back and forth. + +So what happens if you act +with the annihilation operator? + +Should you get 0? + +No, what are you going to get? + +AUDIENCE: Something weird. + +PROFESSOR: Some +random schmutz, right? + +If you just take a and you +act on some stupid state, + +you'll just get some +other stupid state. + +Except for Gaussians +that have been displaced, + +you get a constant +times the same wave + +function, phi 0 of x minus x0. + +Aha. + +It turns out that these +displaced Gaussians + +are eigenstates of the +annihilation operator. + +What does that mean? + +Well, it means they're +coherent states. + +And so the optional +problems are a working + +through of the study +of the eigenfunctions + +of the annihilation operator, +the coherent states. + +Is that cool? + +It's a state, it's +a superposition. + +You can think +about it like this. + +It's a superposition of +the energy eigenstate. + +Any state is a superposition +of energy eigenstates, + +and a coherent state is +just some particularly + +special superposition +of energy eigenstates. + +So you can think about +it literally as c0 phi + +0 plus c1 phi 1 plus c2 +phi 2, blah blah blah. + +What does the +annihilation operator + +do, what does the +lowering operator do? + +It takes any state +and then lowers it + +with some coefficient. + +So a coherent state, an +eigenstate of the annihilation + +operator, must be a +state such that if you + +take c 0 phi 0 plus +c1 phi 1 plus c2 phi 2 + +and you hit it with the +annihilation operator, which + +will give you see c1 phi 0 plus +c2 phi 1 divided by root 2 plus + +dot, dot, dot-- or times +root 2 plus dot, dot, dot. + +It gives you the +same state back. + +So that gave you a relation +between the coefficients c0 + +and c1, c1 and c2, c2 and c3. + +They've all got to be suitable +multiples of each other. + +And what you can show-- and this +is something you work through, + +not quite in this order, on +the optional problems-- what + +you can show is that +doing so it gives you + +a translated Gaussian. + +OK. + +So physically, that's +what a coherent state is. + +Another way to say what +a coherent state is, + +it's as close to +a classical object + +as you're going +to get by building + +a quantum mechanical +wave function. + +It's something that behaves +just like a classical particle + +in that potential +would have behaved, + +in the harmonic +oscillator potential. + +Did that answer your question? + +OK. + +Anything else? + +So, Matt works with +these for a living. + +Matt, do you want +to add anything? + +All right. + +I like these. + +They show up all over the place. + +This is like the spherical +cow of wave functions + +because it's awesome. + +It's an eigenfunction, it's +an annihilation operator, + +it behaves like a +classical particle. + +AUDIENCE: Is there an easy +way to define coherent states + +in potentials where you don't +have nice operators like a? + +PROFESSOR: No, I +mean, that's usually + +what we mean by +a coherent state. + +So the term coherent state +is often used interchangeably + +to mean many different +things, which + +in the case of the harmonic +oscillator, are identical. + +One is a state +which is a Gaussian. + +OK. + +So in the harmonic +oscillator system, + +that's a particularly nice +state because it oscillates + +particularly nicely and it +maintains its probability + +distribution as a function of +time roughly by translating, + +possibly, some phases. + +But people often use the +phrase coherent state + +even when you're not harmonic. + +And it's useful to keep in mind +that we're often not harmonic, + +nothing's truly harmonic. + +You had another question +a moment ago though, + +and your question +was about the width. + +Yeah. + +AUDIENCE: It just translates +without changing its width, + +with or without changing +its shape at all. + +If the Gaussian were +of a different width, + +would that still happen? + +PROFESSOR: Yeah, it does, +although the details of how + +it does so are +slightly different. + +That's called a squeeze state. + +The basic idea of a +squeeze state is this. + +Suppose I have a +harmonic oscillator-- + +and this is actually +one way people + +build squeeze +states in labs-- so + +suppose I have a +harmonic oscillator + +and I put the system +in a ground state. + +So there's its ground state. + +And its width is correlated with +the frequency of the potential. + +Now, suppose I +take this potential + +at some moment in time and +I control the potential, + +the potential is created by +some laser field, for example. + +And some annoying grad student +walks over to the control panel + +and doubles the +power of the laser. + +All of a sudden, I've +squeezed the potential. + +But my system is already in +a state which is a Gaussian, + +it's just the wrong Gaussian. + +So what does this guy do? + +Well, this is funny. + +The true ground state, +once we've squeezed, + +the true ground state +would be something + +that's much narrower +in position space. + +I didn't draw that +very well, but it + +would be much narrower +in position space, + +and thus its +distribution would be + +much broader in momentum space. + +So the state that +we put the system, + +or we've left the system in, has +too much position uncertainty + +and too little +momentum uncertainty. + +It's been squeezed compared +to the normal state + +in the delta x delta p plane. + +It's uncertainty relation +is still extreme, + +it still saturates the +uncertainty bound because it's + +a Gaussian, but it doesn't have +the specific delta x and delta + +p associated with +the true ground + +state of the squeezed potential. + +OK, so now you can ask what +does this guy do in time. + +And that's one of the +optional problems, too, + +and it has many of the nice +properties of coherent states, + +it's periodic, it evolves much +like a classical particle, + +but it's uncertainties +are different + +and they change shape. + +It's an interesting story, +that's the squeezed state. + +Yeah. + +AUDIENCE: Do other +potentials have + +coherent states +that are Gaussian? + +PROFESSOR: It sort of depends. + +So other potentials have +states that behave classically. + +Yeah. + +There are generally-- so +systems that aren't the harmonic + +oscillator do have very +special states that + +behave like a +classical particle. + +But they're not as +simple as annihilations + +by the annihilation operator. + +Come to my office +and I'll tell you + +about analogous +toys for something + +called supersymmetric +quantum models, + +where there's a +nice story there. + +OK. + +I'm going to cut off coherent +states for the moment + +and move on to where we are now. + +OK, so last time we +talked about scattering + +of a particle, a quantum +particle of mass m + +against a barrier. + +And we made a +classical prediction, + +which I didn't quite +phrase this way. + +But we made a +classical prediction + +that if you took this +particle of mass m + +and threw it against a +barrier of height v0, + +that the probability +that it will transmit + +across this barrier to +infinity is basically 0. + +So this is the +classical prediction. + +It will not transmit to +infinity until the energy goes + +above the potential. + +And when the energy is above the +potential, it will slow down, + +but it will transmit +100% of the time. + +So this is our +classical prediction. + +And so we sought to solve +this problem, we did. + +It was pretty straightforward. + +And the energy eigenstate +took the form-- well, + +we know how to +solve it out here, + +we know how to +solve it out here, + +because these are just +constant potentials + +so it's just plain waves. + +Let's take the +case of the energy + +is less than the potential. + +So this guy. + +Then out here, it's in a +classically disallowed state, + +so it's got to be a exponential. + +If we want it to be +normalized, well, we + +need it to be a +decaying exponential. + +Out here it's +oscillatory, because it's + +a classically allowed region. + +And so the general form of the +wave function of the energy + +eigenstate is a superposition +of a wave moving this way + +with positive momentum, a +wave with negative momentum, + +a contribution with +minus k, and out here it + +had to be the +decaying exponential. + +And then by matching, requiring +that the wave function was + +oscillatory and then +exponentially decaying out + +here, and requiring that it was +continuous and differentiably + +continuous-- that its +derivative was continuous-- + +we found matching +conditions between + +the various +coefficients, and this + +was the solution in general. + +OK. + +Now, in particular, +this term, which + +corresponds to the component +of the wave function moving + +towards the barrier on the left +hand side, has amplitude 1. + +This term, which corresponds +to a wave on the left + +with negative momentum, +so moving to the left, + +has amplitude k minus i +alpha over k plus i alpha, + +where h bar squared +k squared upon 2m + +is equal to-- that's just the +energy, e-- and h bar squared + +alpha squared over 2m-- +that's on this side-- is + +equal to v0 minus e. + +But this, notably, +is a pure phase. + +And we understood that, so +we'll call this parameter r, + +because this is +the reflected wave + +and this is an amplitude +rather than a probability, + +so we'll call it little r. + +And we notice that +the probability + +that we get out-- good. + +So if we want to ask +the question, what + +is the transmission probability, +the probability that I get + +from far out here to far out +here, what is that probability? + +So if I consider a state that +starts out as a localized wave + +packet way out here and I +send it in but with energy + +below the barrier, +what's the probability + +that I'll get +arbitrarily far out here, + +that I will subsequently find +the particle very far out here? + +0, right, exactly. + +And you can see that because +here's the probability + +amplitude, the norm +squared is the probability + +density as a function +of the position. + +And it goes like a constant +times e to the minus alpha x. + +For large x, this +exponential kills us. + +And we made that more precise +by talking about the current. + +We said look, the +current that gets + +transmitted is equal to-- that's +a funny way to write things. + +H bar-- sorry. + +The current that +gets transmitted, + +which equal to h bar upon +2mi psi complex conjugate dx + +psi minus psi dx psi complex +conjugate on the right. + +So we'll put right, +right, right, right. + +This is just equal to +0, and the easiest way + +to see that is +something you already + +showed on a problem set. + +The current vanishes +when the wave function + +can be made real up to a phase. + +And since this is some +number, but in particular it's + +an overall constant +complex number, + +and this is a real +wave function, + +we know that this is 0. + +So the transmitted +current out here is 0. + +The flux of particles moving +out to the right is 0. + +So nothing gets +out to the right. + +So that was for the energy +less than the potential, + +and we've now +re-derived this result, + +the classical prediction. + +So the classical prediction +worked pretty well. + +Now, importantly, +in general, we also + +wanted to define the +transmission probability + +a little more +carefully, and I'm going + +to define the +transmission probability + +as the current of +transmitted particles + +on the right divided by the +current of probability that + +was incident. + +And similarly, we can +define a probability + +that the particle +reflects, which + +is the ratio of the reflected +current, the current + +of the reflected beam, +to the incident current. + +So this is going to be the +transmission probability + +and the reflection probability. + +Yeah. + +AUDIENCE: Is there +a square on t? + +PROFESSOR: Thank you. + +OK. + +So let's do a slightly +different example. + +In this example, I want to +study the same system, the wall, + +but I want to consider +a ball incident + +from the left-- a ball. + +An object, a quantum particle +incident from the left, + +with energy greater +than v. Greater than v0. + +So again, classically, what +do you expect in this case. + +You send in the particle, it +loses a little bit of energy + +going up the potential +barrier, but it's still + +got a positive kinetic energy, +and so it just keeps rolling. + +Just like my car making +it up the driveway, + +just barely makes it. + +OK. + +So here again, what's the +form of the wave function. + +Phi e can be put in +the form on the left. + +It's going to be e to the +ikx plus b to the minus ikx, + +and that's over +here on the left. + +And on the right it's +going in the form ce + +to the ik-- in fact, let me call +this k1x and k2x-- or sorry, + +k1x, which is on the left. + +H bar squared k1 squared +upon 2m is equal to e. + +And on the right, we're going +to have k2x because it's, again, + +a classically +allowed region, it's + +going to be oscillatory but +with a different momentum. + +e to the ik2x plus +de to the minus ik2x + +where h bar squared +k2 squared upon 2m + +is equal to e minus v0, +which is a positive number, + +so that's good. + +So here's our wave function. + +Now, before we do +anything else, I + +want to just interpret +this quickly. + +So again, this is like a wave +that has positive momentum, + +and I'm going to say that it's +like a contribution, a term + +in the superposition, that +is moving to the right, + +and the way to think of it +as moving to the right, well, + +first off, it's got +positive momentum. + +But more to the point, this +is an energy eigenstate. + +So how does this +state evolve in time? + +It's an energy +eigenstate with energy, + +how does it evolve in time. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: It rotates by +an overall phase, exactly. + +So we just get this +times an e to the minus + +i omega t, where h bar omega +is equal to e, the energy. + +And that's true on +the left or right, + +because the energy +is just a constant. + +So this term goes as +e to the ikx minus i + +omega t, or kx minus omega t. + +And this is a point +of constant phase + +in this move to the right. + +As t increases-- in order +for the phase to be constant + +or for the phase, for example, +to be 0-- as t increases, + +x must increase. + +By assumption here, k +is a positive number. + +On the other hand, this guy-- +that was a k1-- the second term + +is of the form e +to the minus ik1x, + +and when I add the omega +t, minus i omega t, + +this becomes kx plus omega t. + +So point of constant +phase, for example, phase + +equals 0, in order for this to +stay 0 then, as t increases, + +x must become negative. +x must decrease. + +So that's why we +say this corresponds + +to a component of +the wave function, + +a term in the superposition +which is moving to the left. + +And this is one which +is moving to the right. + +Sorry, my right, your left. + +Sorry, this is +moving to your right + +and this is moving to your left. + +OK? + +It's that little z2, it's +harder than it seems. + +OK. + +In this set up, we could +imagine two different kinds + +of scattering experiments. + +We can imagine a +scattering experiment + +where we send in a particle from +the left and ask what happens. + +So if you send in a +particle from the left, + +what are the logical +possibilities? + +AUDIENCE: It can go through. + +PROFESSOR: It could +go through, or? + +AUDIENCE: Reflect back. + +PROFESSOR: Reflect back. + +Are you ever going to get a +particle spontaneously coming + +from infinity out here? + +Not so much. + +So if you're sending a +particle in from the left, + +what can you say about +these coefficients? + +d equals 0 and a +is not 0, right. + +Because d corresponds to a +particle on the right hand + +side coming in this way. + +So that's a different +scattering experiment. + +So in particular, +coming in from the left + +means d equals 0 and +a not equal to 0. + +Coming in from the right +means a equals 0 and d + +not equal to 0 by +exactly the same token. + +Cool? + +So I want to emphasize this. + +a and d, when you think of +this as a scattering process, a + +and d are in guys. + +In, in. + +And c and b are out. + +This term corresponds to +moving away from the barrier, + +this term corresponds to +moving away from the barrier, + +just on the left +or on the right. + +OK? + +Out and out. + +Everyone happy with that? + +Yeah. + +AUDIENCE: According to that +graph, if d is-- no, that one. + +Yeah. + +If d is bigger than [INAUDIBLE] +then the transplants will be 1. + +Doesn't that mean +that d is also 0? + +PROFESSOR: So this is +the classical prediction. + +I've written it, +classical prediction. + +So let me rephrase. + +The question was +basically, look, + +that classical +prediction implies + +that b must be 0 on the +other scattering process, + +and that doesn't sound right. + +So is that true? + +No, it's not true, and we'll +see it again in a second. + +So very good intuition. + +That was good. + +OK, good. + +So in general, if we have +a general wave function, + +general superposition of the +two states with energy e with + +a,b,c, and d all +non-0, that's fine. + +That just corresponds +to sending some stuff + +in from the right and +some stuff in-- sorry, + +some stuff in from the left and +some stuff in from the right. + +Yeah? + +But it's, of course, +going to be easier + +if we can just do a +simpler experiment. + +If we send in stuff +from the left or send in + +stuff from the right. + +And if we solve those +problems independently, + +we can then just +superpose the results + +to get the general solution. + +Yeah. + +So it will suffice +to always either set + +d to 0 or a to 0, +corresponding to sending things + +in from the left or sending +things in from the right. + +And then we can just take +a general superposition + +to get the general answer. + +Everyone happy with that? + +So let's do that in this set up. + +So here's our wave function. + +And you guys are now adept at +solving the energy eigenvalue + +equation, it's just the matching +conditions for a,b,c, and d. + +I'm not going to +solve it for you, + +I'm just going to +write down the results. + +So the results-- in fact, +I'll use a new border. + +The results for this guy, +now for e greater than v, + +are that-- doo doo doo, +what just happened. + +Right, OK, good. + +So let's look at the case +d equal 0 corresponding + +to coming in from the left. + +So in the case of +in from the left, + +c is equal to 2k1 +over k1 plus k2, + +and b is equal to k1 +minus k2 over k1 plus k2. + +And this tells us, running +through the definition of j, + +the currents, and t and r, gives +us that, at the end of the day, + +the reflection coefficient is +equal to k1 minus k2 upon k1 + +plus k2 [INAUDIBLE] squared, +whereas the transmission + +amplitude or probability +is equal to 4k1 k2 over k1 + +plus k2 squared. + +And a good exercise for +yourself is to re-derive this, + +you're going to have to do that +on the problem set as a warm + +up for a problem. + +So at this point +we've got an answer, + +but it's not terribly satisfying +because k1 and k2, what's + +the-- so let's put +this in terms of a more + +easily interpretable form. + +k1 and k2 are nothing other +than code for the energy + +and the energy +minus the potential. + +Right, so we must be able to +rewrite this purely in terms + +of the energy in the +potential e and v. In fact, + +if we go through and +divide both top and bottom + +by k1 squared for +both r and t, this + +has a nice expression +in terms of the ratio + +of the potential to the energy. + +And the nice expression is +1 minus the square root of 1 + +minus v0 over e over +1 plus the square root + +of 1 minus v0 over +e norm squared. + +And suddenly, the +transmission amplitude + +has the form 4 root 1 +minus v0 over e over 1 + +plus the square root of 1 +minus v0 over e squared. + +I don't remember which +version of the notes + +I posted for this year's course. + +In the version from +2011 there is a typo + +that had here e over v, and +in the version from 2012, that + +was corrected in the +notes to being v0 over e. + +So I'll check, but let me +just warn you about that. + +On one or two pages of +the notes, at some point, + +these guys were inverted +with respect to each other. + +But the reason to +write this out is now + +we can plot the following. + +We can now plot the quantum +version of this plot. + +We can plot the actual +quantum transmission + +as a function of energy, +and the classical prediction + +was that at energy +is equal to v0, + +we should have a step function. + +But now you can see that +this is not a step function, + +and that's related to the fact +that b was not actually 0, + +as you pointed out. + +Hold on one sec. + +Sorry, was it quick? + +AUDIENCE: The notes are wrong. + +PROFESSOR: OK, the notes +are wrong, good, thank you. + +That's great. + +OK, so the notes are wrong. + +It should be v0 over e, +not e over v0 on the notes + +that are posted. + +We're in the process +of teching them up, + +so eventually a beautiful set +of nice notes will be available. + +Extra elbow grease. + +OK. + +So what do we actually see? + +Here we got for e +less than v0, we + +got in d that the transmission +probability was exactly 0. + +So that's a result for +the quantum result. + +But when e is equal +to v0, what do we get? + +Well, when e is equal +to v0, this is 1. + +And we get square +root of 1 minus 1, + +which is square root of +0, over square root of 1 + +plus square root of 1 +minus 1, which is 0. + +That's 0 over-- OK, good. + +So that's not so bad. + +Except for this 1 over this e, +this is a little bit worrying. + +If you actually +plot this guy out, + +it does this, where +it asymptotes to 1. + +And to see that it +asymptotes to 1, + +to see that it asymptotes +to 1, just take e0 gigantic. + +If you know it's gigantic, +this becomes v0 over e, + +which goes to 0, and if e is +much larger than the potential. + +So this becomes +square root of 1. + +And in the denominator, this +becomes square root of 1, 1 + +plus 1, that's 2 squared, 4, 4 +divided by 4, that goes to 1. + +So for large e much larger +than v0, this goes to 1. + +So we do recover the +classical prediction + +if we look at energy +scales very large + +compared to the +potential height. + +Yeah? + +OK. + +So that's nice. + +Another thing +that's nice to note + +is that if you take this +reflection probability + +and this transmission +probability, + +then they sum up to 1. + +This turns out to +be a general fact + +and it's a necessary +condition in order for those + +to be interpretable +as reflection + +in transition probabilities. + +The probability +that it transmits + +and the probability that it +reflects had better add to 1, + +or something is eating +your particles, which + +is probably not what +you're looking for. + +So this turns out to be true +in this case, just explicitly. + +But you can also, as you +will in your problem set, + +prove that from that definition +r and t, it's always true. + +A check on the sensibility +of our definition. + +If it weren't true, +it wouldn't tell you + +that quantum +mechanics is wrong, it + +would tell you that we +chose a stupid definition + +of the transmission and +reflection probabilities. + +So in this case, we actually +chose quite an enlightened one. + +OK, questions at this point? + +Yeah. + +AUDIENCE: Does +this analysis even + +hold for classical particles? + +If we're talking about the +difference between-- like + +if I threw a baseball and +I happened to throw it + +at a potential that had height +one millionth of a joule + +less than the energy +of the baseball, + +would we observe this also? + +PROFESSOR: No. + +AUDIENCE: No? + +PROFESSOR: No, for +the following reason. + +So here's my classical system. + +Classical system is +literally some hill. + +So where I was +growing up as a kid, + +there was a hill not +far from our house. + +I'm not even going to go +into it, but it was horrible. + +If you have energy just +ever so slightly greater + +than the hill-- he said +from some experience-- + +if you have energy that's +ever so slightly greater-- OK. + +I'm going resist the temptation. + +So one of these days. + +If you have ever so slightly +greater than the hill, + +and you start up here, +what does that tell you? + +What does it mean to +say you have energy + +just ever so slightly greater +than the potential energy + +at that point? + +AUDIENCE: Up more slowly. + +PROFESSOR: Little tiny velocity. + +OK, and I'm going to say I +have a little tiny velocity + +this way. + +OK. + +So what happens? + +We follow Newton's equations. + +They are totally unambiguous, +and what they tell you is, + +with 100% certainty, this thing +will roll and roll and roll, + +and then all hell +will break loose. + +And then if you're +very lucky, your car + +gets caught in the trees on +the side of the cliff, which + +is later referred to by the +policeman who helps you tow it + +out as nature's guard rail. + +I was young, it +won't happen again. + +And So with 100% certainty, +Newton's equations + +send you right off the cliff. + +And for style points, backward. + +So now I'm going to +do the second thing. + +Newton's laws satisfy +time reversal invariance. + +So the time reversal of +this is, this thing has + +this much energy, and +it shoots up the cliff. + +And ever so slowly, +it just eventually + +goes up to the top, +where everything is fine. + +OK, but does it ever +reflect back downhill? + +No. + +And does it ever-- +classically, when + +you roll the thing-- +does it ever actually not + +go off the cliff +and hit the trees, + +but instead reflect backwards. + +I wish the answer were yes. + +But sadly, the answer is no. + +Now, if that car had been +quantum mechanically small, + +my insurance would have +been much more manageable. + +But sadly, it wasn't. + +OK, so this is a pretty +stark and vivid-- this + +is a pretty stark difference +between the quantum + +mechanical prediction and +the classical prediction. + +Everyone cool with that? + +Other questions? + +Yeah. + +AUDIENCE: I understand why +it works out that r plus t + +equals 1, but I'm +not sure I understand + +the motivation to use the +square with the ratios. + +PROFESSOR: Excellent, OK. + +So the reason to do it, +so great, excellent. + +How to say. + +Here's one way to +think about it. + +The first thing +we want is we want + +a-- so this is a +very good question, + +let me repeat the question. + +The question is, look, +why is it squared? + +Why isn't it linear? + +So let's think about that. + +Ah, ah, ah. + +The reason it's squared +is because of a typo. + +So let's think about-- + +[LAUGHTER] + +PROFESSOR: Let's +step back for second + +and let's think, OK, it's +a very good question. + +So let's think about +what it should be. + +OK. + +For the moment, put an +arbitrary power there. + +OK. + +And let's think about +what it should be. + +Thank you so much +for this question. + +I owe you, like, a plate +of cheese or something. + +That's high praise, guys. + +France, cheese. + +So should it be linear or +should it be quadratic? + +What is that supposed +to represent? + +What is T, the capital +T, supposed to represent? + +AUDIENCE: The probability +of transmission. + +PROFESSOR: The probability +of transmission, exactly. + +The wave function. + +Is the wave function, +the value of the wave + +function at some point, +is that a probability? + +It's a-- + +AUDIENCE: Probability +of density. + +No, it's the square root. + +PROFESSOR: Is it a +probability of density? + +It is a probability amplitude. + +It is a thing whose norm +squared is a probability. + +So we want something that's +quadratic in the wave function, + +right. + +Meanwhile, some time before, +we wanted a definition + +of how much stuff is moving +past a point in the given + +moment in time. + +What's the probability +density moving past a point + +at a given moment in time. + +And that's where we got the +current j from the first place. + +j was the probability +density moving past a point + +at a given moment in time. + +So notice that j is quadratic +in the wave function, + +so it's how much stuff is moving +past any particular direction-- + +we chose it to be the incident +to the reflected bit-- + +at a moment in time. + +So it's a probability density-- +it's actually a current-- + +and it's quadratic +in the wave function. + +So it has the right units +and the right structure + +to be a probability. + +If we squared that, we would be +in trouble, because it wouldn't + +be a probability, it would +be a probability squared. + +And in particular, it +wouldn't normalize correctly. + +So that typo was +actually a bad typo. + +So what happened, now +thinking back to-- you + +have a video someday, +so you can scroll back. + +What happened was I didn't +put the squared on the first, + +I put the squared on the +second, and then someone said + +squared on the first? + +Like, yes. + +But the correct answer is +no squared on the second. + +So there are no squareds. + +Thank you for the question. + +Very good question. + +In particular, +the thing that was + +so awesome about +that question was it + +was motivated by physics. + +It was like, look, why is this +thing squared the right thing? + +That's two factors +of the wave function, + +it's already quadratic. + +It should be like a probability. + +Why are you squaring it? + +Very good question. + +Yeah. + +AUDIENCE: So in the +transmission probability, + +why do we know it's 0 if +the energy is less than v0? + +I mean, is there any rule? + +PROFESSOR: Yeah, OK, good. + +We'll come back to that +question in a little bit, + +but let me just quickly +say that we calculated it, + +and we see explicitly +that it's 0. + +Now you might say well, +look, the true wave function + +has a little bit of a tail. + +So there's some +[INAUDIBLE] probability + +you'll find it here if +you do a measurement. + +But the question we want +to ask in transmission + +is, if you send it in +from far away over here, + +how likely are you to catch +it far away over here? + +And the answer is, you are not. + +That make sense? + +OK, good. + +OK, so so much for that one. + +Now, here's a fun +fact, I'm not going + +to go through this +in any detail. + +We could have done exactly +the same calculation-- OK, + +we could have done +the same calculation + +sending something +in from the right. + +And sending something in from +the right, in on the right, + +corresponds to d not +equal to 0 and nothing + +coming in from the +left, that's a equals 0. + +So we could have done +the case a equals 0, + +which is in from the right. + +And if you do that +calculus, what you find + +is c is equal to k1 minus +k2 upon k1 plus k2 d. + +And b is equal to 2k1 +upon k1 plus k2 d. + +And this says that +plugging these guys in, + +the reflection and the +transmission are the same. + +In particular, physically, +what does that mean? + +That means the reflection +and transmission + +are the same uphill as downhill. + +Downhill is uphill, +they're the same both ways. + +But that's truly weird, right? + +What's the probability to +transmit quantum mechanically + +if you have just a +little bit of energy + +and you send the particle in? + +How likely are you +to go off the cliff. + +If we have energy ever so +slightly greater the potential, + +and the transmission +amplitude is the same downhill + +as it was uphill, how likely are +you to fall off the potential? + +AUDIENCE: Always. + +PROFESSOR: Never. + +Because if energy is just +slightly greater than v0, + +then the transmission +probability is very, very low. + +The transmission to +go from here to here + +is extremely low +if the energy is + +close to the height +of the barrier. + +So had I only been on a +quantum mechanical hill, + +I would have been just fine. + +This is a really +striking result, + +but this thing, the +fact that you're + +unlikely to scatter uphill, +that's maybe not so shocking. + +But you're really unlikely +to scatter downhill, + +that is surprising. + +So I'll leave it to you +to check that, in fact, + +the transmission, when we +do it in from the right, + +the transmission and reflection +probabilities are the same. + +Recalling that transmission +means going this way, + +reflection means bouncing +back to the right. + +Cool? + +Yeah. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Uh, because, again. + +Jeez, today is just a disaster. + +Because there's a typo. + +This should be times a. + +God. + +And the reason you know it +should be times a, first off, + +is that these should have +the appropriate dimensions. + +So there should be an +appropriate power of a. + +And the second thing is that +if you double this stuff in, + +you'd better double +this stuff out. + +So if you double a, +you'd better double c. + +So you know there had better +be a factor of a here. + +And that's just a typo again. + +I'm sorry, today is a bad +day at the chalkboard. + +Thank you for that question. + +Yeah. + +AUDIENCE: Is there +a physical reason + +for why r and t are the same +and so different from what + +you would classically expect, +or is that just the way the math + +works? + +PROFESSOR: There is. + +I want you to ponder that, +and either at the end of today + +or at the beginning +of tomorrow, we'll + +talk about that +more in detail when + +we've done a little +more technology. + +It's a good question +and you should + +have that tingling +sensation in your belly + +that something is +confusing and surprising + +and requires more explanation, +and we'll get there. + +But I want you to just think +about it in the background + +first. + +Yeah. + +AUDIENCE: Is there any +physical experiment + +where r and t don't sum up to 1? + +PROFESSOR: Mm mm. + +Nope. + +So the question is, is +there any experiment + +in which r and t +don't sum up to 1? + +And there are two +ways to answer that. + +The first way to answer +that is, it turns out + +that r and t adding up to 1 +follows from the definitions. + +So one of the things you'll +do on the problem set + +is you'll show that using these +definitions of the transmission + +and reflection of +probabilities, they necessarily + +add up to 1, strictly. + +They have to. + +It follows from the +Schrodinger equation. + +The second answer +is, let's think + +about what it would mean if +r and t didn't add up to 1. + +If r and t didn't +add up to 1, then + +that would say, +look, if you throw + +a particle at a barrier, at +some feature in a potential, + +some wall, then the +probability that it + +goes this way at the end +versus the probability + +that it goes that way at the +end if you wait long enough + +is not 1. + +So what could have happened? + +What could have +gotten stuck in there? + +But that doesn't even +conserve momentum, + +not even approximately. + +And we know that the +expectation of momentum + +is time independent +for a free particle. + +In between while it's +actually in the potential, + +it's not actually +time independent, + +there's a potential, +there's a force. + +AUDIENCE: I mean, if it's whole +particles, can't some of them + +get annihilated or something? + +PROFESSOR: Ah, well OK. + +So if you're talking +about multiple particles + +and interactions amongst +multiple particles, + +then it's a slightly more +complicated question. + +The answer there +is still yes, it + +has to be that the +total probability in + +is the total probability out. + +But we're only going to talk +about single particles here. + +But it's always true +that for-- we're + +going to take this +as an assumption, + +that things don't +just disappear, + +that the number of particles +or the total probability + +is conserved. + +There's a third way to +say this, this really + +isn't independent +from the first. + +Remember that these were +defined in terms of the current? + +The current satisfies-- +the current concept + +of probability conservation +equation dt of rho + +is equal to the gradient minus +the gradient of the current. + +So the probability +is always conserved, + +the integral of probability +density is always conserved, + +it's time independent. + +AUDIENCE: So it's +by [INAUDIBLE]. + +PROFESSOR: Yeah, +it's by construction. + +Exactly. + +Yeah? + +AUDIENCE: Looking at your +expression for the transition + +probability, I'm having trouble +seeing how that works out to 0 + +when e is less than v0? + +PROFESSOR: Oh, this +expression is only + +defined when e is equal to v0. + +Because we derived this-- +excellent question-- + +we derived this assuming that +we had an energy greater than v0 + +and then that the wave +function had this form. + +You cannot use this form of the +wave function if the energy is + +less than v0. + +If the energy is +less than v0, you've + +got use that form of +the wave function. + +And in this form of +the wave function, + +we derived that the +transition amplitude is 0, + +because the current on the +right, the transmitted current, + +is 0. + +So this calculation +is appropriate + +when e is less than v0 and +this calculation is appropriate + +when e is greater than v0. + +So you're absolutely correct. + +You can't use this +one e is less than v0, + +it gives you not +the same answer. + +In fact, it gives +you a complex-- + +it's kind of confusing. + +The factors cancel. + +So it's not really a +probability at all, + +and indeed, this is just not +the right quantity to use. + +AUDIENCE: All right, cool. + +PROFESSOR: Cool? + +All right. + +So there are a +bunch of nice things + +I want to deduce from +what we've done so far. + +So the first is, +look, I pointed out + +that this can be +derived just explicitly + +and it gives the same +results as before. + +That's not an accident. + +If you take this +system and you just + +reverse the roles of k1 +and k2, what happens? + +Well that's just +replaces e by e minus v0, + +we can do that by doing this, +replacing e by e minus v0 + +and e minus v0 by e, it +swaps the role of a and d, + +and it gives you exactly +the same things back. + +So if you're careful +about that, you never + +have to do this calculation. + +You can just do the +appropriate transformation + +on that calculation and it gives +you the exactly the same thing. + +It's the same algebraic steps. + +But the other thing +that's nice is + +that you can actually do +the same thing from here. + +So as long as you +set the d equals 0-- + +so there's another term +here that we neglected, + +the plus delta x, +we got rid of it. + +But you can analytically +continue this calculation + +by noting that look, +if we just set alpha, + +we want minus alpha +equals ik2, then + +the algebra is all +going to be the same. + +We just have ik2 +instead of minus alpha. + +So we can just replace +alpha with minus ik2 + +everywhere in our +expressions, being + +careful about +exactly how we do so, + +being careful to +take care of factors + +of i and such correctly. + +And you derive the same +results for both cases, which + +is a nice check on +the calculation. + +So often, when you get a little +bit of experience with these, + +you don't actually have +to do the calculation. + +Again, you can +just take what you + +know from a previous +calculation and write down + +the correct answer. + +So it's a fun +thing to play with, + +exactly how do you do that. + +So I invite you to think +through that process + +while you're doing +your problem set. + +Another thing is the +reflection downhill + +thing which is +pretty surprising. + +But here's the thing that +I really want to emphasize. + +What this calculation +shows you is not so much + +that-- it's not just that +transmission downhill + +is highly unlikely +when the energy is + +very close to the height +of the potential barrier. + +That's true, but it's not +the most interesting thing + +about this calculation. + +The most interesting thing about +this calculation, to my mind, + +is the fact that from +the detailed shape + +of the transmission as +a function of energy, + +we can deduce what +the potential is. + +Think about what that tells you. + +If you do an experiment, +you have a barrier, + +and you want to know the +shape of the barrier. + +Is it straight, +is it wiggly, does + +it have some complicated shape. + +How do you measure that? + +Well, you might measure +it by just looking. + +But imagine you can't, +for some reason. + +For whatever, it's in a box +or you can't look at it. + +Maybe it's just +preposterously small. + +How can you deduce what +the shape of that hill is? + +Well, one way to +do it is to send + +in particles as a function of +energy, more and more energy, + +and measure the probability +that they transmit. + +OK. + +Now if you do so and you get +this graph as a function of e, + +what do you deduce? + +You deduce that the barrier +that you're scattering off of + +is a square step +with this height v0. + +Are we cool with that? + +So apparently, just +look at the transmission + +amplitudes, the +transition probabilities, + +you can deduce at +least something + +of the form of the potential. + +Which is kind of cool. + +If you didn't know +the potential, + +you could figure +out what it was. + +And this turns out to be a +very general statement that you + +can deduce an enormous +amount, and as we'll see, + +you can, in fact, +deduce basically + +everything you want +of the potential + +from knowing about the +transmission probabilities + +as well as the phase shift, +the transmission amplitudes. + +So this is the basic +goal of scattering. + +And so the way I +want you to think + +about it is imagine, for +example, that someone + +hands you an object. + +A box. + +And the box has an in port +and it has an out port. + +And they allow you +to send in particles + +as a function of energy +and measure transmission + +and reflection, you can measure +transmission and reflection. + +Just like I'm measuring +transmission off of your faces + +right now, from the +light from above. + +So suppose that you do so, put +it on your test stand and you + +measure transmission. + +You measure transmission +as a function of energy, + +and you observe the following. + +The transmission as +a function of energy + +is small up until some point, +and then at some point, + +which may be the minimum energy +you can meaningfully probe, + +you get something like this. + +So here's the transmission +as a function of energy. + +So what can you say? + +If this is all the +information you + +have about what's going +on inside the box, + +what can you deduce about +the thing inside the box? + +One thing you can +deduce is that it + +looks kind of like a potential +with height around v0. + +It looks kind of like a +potential step with some height + +v0. + +This is asymptoting to 1. + +However, it's not, because it +has these oscillations in it. + +So there's more to the potential +than just a barrier of height + +v0. + +What I want to show you is +that you can deduce everything + +about that potential, and +that's the point of scattering. + +So let's do it. + +So the goal here, again, to say +it differently, is what's v0? + +What is v of x? + +Not just the height, +but the total potential. + +So another way to say +this, let me set up + +a precise version +of this question. + +I want to be able +to do the following. + +I want to take a system that has +a potential which is constant + +up to some point +which I'll call 0, + +and then again from some +point, which I'll call L, + +is constant again. + +And inside, I don't know +what the potential is. + +So in here, there's +some unknown potential, + +v of x, which is +some crazy thing. + +It could be doing anything. + +It could be some crazy-- it +could have horns and whatever. + +It could be awful. + +But the potential is constant +if you go far enough away, + +and the potential is constant +if you go far enough away. + +A good example of this +is a hydrogen atom. + +It's neutral but there's +a clearly and complicated + +potential inside because +the proton and the electron + +are moving around in there in +some quantum state, anyway, + +and if you send something +at it, far away, it's + +as if it's not there. + +But close by, you know there +are strong electrostatic forces. + +And so the question is what +you learn about those forces, + +what can you learn +about the potential + +by throwing things in from +far away, from either side. + +Now one thing we know already +is that out here, the wave + +function always-- because it's +a constant potential-- always + +takes the form e to the ikx +plus b e to the minus ikx. + +And out here it takes the +form c e to the ikx plus d + +e to the minus ikx. + +And again, this +corresponds to moving in. + +d is in from the right. + +c is out to the right. + +b is out to the left. + +And a is in from the left. + +So again, there are +basically four kind + +of scattering +experiments we can do. + +We can send things in +from the right, which + +corresponds to setting a to 0. + +We can send things in +from the left, which + +corresponds to +setting t equal to 0. + +And all the information +about what happens in v + +is going to be encoded +in what's coming out, + +the b and c coefficients. + +And the way to make +that sharp is just + +to notice that the transmission +probability, if we compute + +for this system, assuming +it's forming the wave function + +asymptotically away from the +potential, the transmission + +amplitude is just +c over a squared + +when you're sending +in from the left. + +And the reflection is equal +to b over a norm squared. + +This squared is a squared. + +[INAUDIBLE] function over +amplitude squared, good. + +To learn about the transmission +and reflection coefficients, + +it's enough-- suffices-- +to compute, to know b and c + +as a function of a and d. + +All of the scattering +information + +is in those coefficients +b and c for a and d. + +And here I'm assuming that I'm +sending in a monochromatic wave + +with a single, well +defined energy. + +I'm sending in a beam of +particles with energy e. + +I don't know where +they are, but I sure + +know what their momentum is. + +So some well defined beam +of particles with energy e. + +And these +probabilities are going + +to contain all the data I want. + +So this is the basic +project of scattering. + +Questions? + +AUDIENCE: So basically, +it only depends + +on the transmission-- it +only depends on the edges? + +PROFESSOR: That's +a good question. + +The question is, does the +transmission depend only + +on what you do with the edges. + +And here's the important thing. + +The transmission +depends crucially + +on what happens in here. + +For example, if this is an +infinitely high barrier, + +nothing's going across. + +So this transmission +depends on what's in here. + +But the point is we can deduce +just by looking far away, + +we can deduce the +transmission probability + +and amplitude just by +measuring b and c far away, + +b and c far away. + +OK. + +So the transmission +amplitude is something + +you measure when very far away. + +You measure-- if I throw +something in from very far + +out here to the left, how likely +is it to get out here very + +far to the right? + +And in order to answer +that, if someone + +hands you the +answer to that, they + +must have solved +for what's inside. + +That the point. + +So knowing the answer +to that question + +encodes information about +what happened in between. + +AUDIENCE: So I guess +initially, your potential's + +going to-- so say it's +stuff you did earlier. + +The potential drops down to +the [INAUDIBLE] in the box. + +Is that going to be problematic? + +PROFESSOR: Yeah, +for simplicity, I'm + +going to assume that the +potential always goes to 0 when + +we're far away, because that's +going to be useful for modeling + +things like hydrogen +and, exactly. + +Carbon, we're going +to do diamond later + +in the semester, +that'll be useful. + +But we could repeat +this analysis + +by adding an extra change +in the asymptotic potential, + +it doesn't really change +anything important. + +Yeah. + +AUDIENCE: It looks like even +for just the simple step up + +[INAUDIBLE] you can't tell +from just the probabilities why + +the step is going +up or going down. + +PROFESSOR: Ah, excellent. + +Excellent, excellent. + +So good, thank you for that +question, that's really great. + +So already, it seems +like we can't uniquely + +identify the potential from +the transmission probability + +if the transmission probability +is the same for step up + +or step down. + +So what's missing? + +AUDIENCE: Maybe the +energy [INAUDIBLE] + +PROFESSOR: But we're working +with an energy [INAUDIBLE]. + +So the energy is just +a global constant. + +We'll see what's +missing, and what's + +missing is something +called the phase shift. + +So very good question, yes. + +AUDIENCE: It looks like when we +did the example for the step, + +that t equals [INAUDIBLE] +over a squared. + +PROFESSOR: Yeah, it is, +because it's the ratio. + +That's why I wrote +t is c over here. + +So t is the ratio of j over ji. + +And in fact, jt here is +equal to c squared times-- + +so this is the +probability density, + +so it's the probability density +times the velocity, what's + +the effect of velocity here? + +H bar k 2 over m, whereas +j incident is equal + +to a squared-- +probability density + +times the momentum there, +the velocity there-- + +which is h bar k1 upon m. + +So here the ratio of j +transmitted to j incident + +is norm c squared k2 +over norm a squared k1. + +AUDIENCE: So because +it's not level-- + +PROFESSOR: Exactly, it's +because it's not level. + +So here, they +happen to be level, + +so they're only +[INAUDIBLE] factor, cancel, + +and the only thing that +survives is the amplitude. + +Good question. + +Yeah. + +AUDIENCE: For the +lead box example, + +is it sufficient +just to know what's + +reflected back to +solve the situation? + +PROFESSOR: So for +precisely for this reason, + +it's not sufficient to know t. + +It's not sufficient +to know t and r. + +But, of course, once +you know r, you know t, + +so you're exactly right. + +Once you know the +reflection probability, + +you know the +transmission probability, + +but there's one more +bit of information + +which we're going to +also need in order + +to specify the potential, which +is going to be the phase shift. + +But you're right, you don't +need to independently compute + +r and t, you can +just compute one. + +AUDIENCE: You need sensors +on both sides of the box, + +to answer my question. + +PROFESSOR: You +don't need sensors + +on both sides of the box, but +you need to do more than just + +do the counting problem. + +We'll see that. + +OK. + +So let's work out a simple +example, the simplest + +example of a barrier +of this kind. + +We want constant potential, +and then ending at 0, + +and we want a constant again +from L going off to infinity. + +So what's the easiest +possible thing we could do? + +Step, step. + +We're just doing what +we've done before twice. + +So this is an example of +this kind of potential. + +It's sort of ridiculously +simple, but let's work it out. + +So we want scattering, +let's start out, + +we could do either +scattering from the left + +or scattering from the right. + +Let's start out scattering +from the left, so d equals 0, + +and let's study this problem. + +So what we know-- +and let's also note + +that we have a choice to make. + +We could either study +energy below the height + +of the potential or +we can study energy + +above the height +of the potential. + +And so for simplicity, +I'm also going + +to start with energy +greater than the height + +of the potential, v0, and +then we'll do e less than v0 + +afterwards. + +It'll be an easy extension +of what we've done. + +OK, so this will be our +first case to study. + +So we know the form of the +wave function out here, + +it's a e to the ikx, +b to the minus ikx. + +We know that for the +potential out here + +it's c e to the ikx and +d e to the minus ikx. + +The only thing we +don't know is the form + +of the potential in here. + +And in here it's +actually very simple. + +It's got to be something +of the form-- I + +think I called it +f and g, I did. + +f e to the ik prime +x-- I'm calling this k, + +so I'll just call this +k prime x-- plus g + +e to the minus ik prime x. + +And the reason I +chose k prime is + +because we're working +with energy greater + +than the potential, so this is +a classically allowed region. + +It's an oscillatory domain +but with a different k prime. + +So here, k squared, h bar +squared over 2m is equal to e, + +and h bar squared k +prime squared over 2m + +is equal to e minus +v0, which is positive + +when e is greater than v0. + +This analysis will not obtain +when e is less than v0, + +we'll have to treat +it separately. + +So now what do we do? + +We do the same thing we did +before, we just do it twice. + +We'll do the matching +conditions here, + +the matching conditions here. + +That's going to give us 1, +2, 3, 4 matching conditions. + +We have 1, 2, 3, 4, 5, +6 unknown coefficients, + +so we'll have two +independent ones. + +That's great. + +We set d equal to 0 +to specify that it's + +coming in from the left and +not from the right, that's 5. + +And then we have +normalization, which is 6, + +so this should uniquely +specify our wave function. + +Yeah. + +Once we've fixed e, we +have enough conditions. + +So I'm not going to go +through the derivation + +because it's just an extension +of what we did for the first. + +It's just a whole +bunch of algebra. + +And let me just emphasize this. + +The algebra is not interesting. + +It's just algebra. + +You have to be +able to do it, you + +have to develop some +familiarity with it, + +and it's easy to +get good at this. + +You just practice. + +It's just algebra. + +But once you get the idea, +don't ever do it again. + +Once you get +reasonably quick at it, + +learn to use Mathematica, Maple, +whatever package you want, + +and use computer algebra +to check your analysis. + +And use your physics +to check the answer + +you get from Mathematica or +Maple or whatever you use. + +Always check against +physical reasonability, + +but use Mathematica. + +So posted on the website +are Mathematica files + +that walk through the +computation of the transmission + +and reflection amplitudes +and probabilities + +for this potential, and I +think maybe another one, + +I don't remember exactly. + +But I encourage you strongly +to use computer algebra tools, + +because it's just +a waste of time + +to spend three hours doing +an algebra calculation. + +In particular, on your +problem set this week, + +you will do a scattering problem +similar to the bound state + +probably you did last week, the +quantum glue problem-- which + +you may be doing tonight, +the one due tomorrow. + +Which is two delta +function wells + +and find the bound +states, so that + +involves a fair +amount of algebra. + +The scattering +problem will involve + +a similar amount of algebra. + +Do not do it. + +Use Mathematica or +computer algebra + +just to simplify your life. + +So if we go through and +compute the-- so what + +are we going to do, we're +going to use the matching + +conditions here to determine +f and g in terms of a and b, + +then we'll use the +matching conditions here + +to determine c-- d is 0-- +c in terms of f and g. + +So that's going to give us an +effective constraint relating + +a and b, leaving us with an +overall unknown coefficient + +a, which we'll use +for normalization. + +The upshot of all of +which is the answers + +are that, I'm not even going +to write down-- they're + +in the notes. + +Should I write this down? + +I will skip. + +So the upshot is that the +transmission amplitude, + +as a function of k and k prime-- +the transmission probability, I + +should say, is 1 +over-- actually, + +I'm going to need +the whole amplitude. + +Shoot. + +The transmission +probability is equal to-- + +and this is a horribly +long expression-- + +the transmission probability, +which is c over a norm squared, + +is equal to 4 k squared k prime +squared cosine squared of k + +prime l plus k squared plus +k prime squared sine squared + +of k prime l under 4k +squared k prime squared. + +Seriously. + +So we can simplify this out, +so you can do some algebra. + +This is just what +you get when you just + +naively do the algebra. + +I want to do two things. + +First off, this is horrible. + +There's a cosine squared, +there's a sine squared, + +surely we can all be +friends and put it together. + +So let's use some trig. + +But the second thing, and +the more important thing, + +is I want to put this +in dimensionless form. + +This is horrible. + +Here we have ks and we have ls, +and these all have dimensions, + +and they're inside the sines +and the cosines it's kl. + +That's good, because this +has units of one over length, + +this has units of length, +so that's dimensions. + +Let's put everything +in dimensionless form. + +And in particular, what are +the parameters of my system? + +The parameters of my system +are, well, there's a mass, + +there's an h bar, there's a +v0, and then there's an energy, + +and there's a length l. + +So it's easy to make a +dimensionless parameter out + +of these guys, and a +ratio of energies-- + +a dimensionless ratio of +energies-- out of these guys. + +So I'm going to do that, and +the parameters I'm going to use + +are coming from here. + +I'm going to define the +parameters g0 squared, which + +is a dimensionless measure of +the depth of the potential. + +We've actually run +into this guy before. + +2m l squared v0 +over h bar squared. + +So this is h bar squared, 1 over +l squared is k squared over 2m, + +so that's an energy. + +So this is a ratio of the +height of the potential + +to the characteristic energy +corresponding to length scale + +l. + +So the width, there's an +energy corresponding to it + +because you take a momentum +which has 1 over that width. + +You can build an energy out of +that h bar k squared over 2m. + +And we have an energy which +is the height of the barrier, + +we take the ratio of those. + +So that's a dimensionless +quantity, g0. + +And the other dimensionless +quantity I want to consider + +is a ratio of the +energy, e, to v0, + +which is what showed up +before in our energy plot. + +Or in our transmission +plot over there, e over v0. + +So when we take this and we +do a little bit of algebra + +to simplify our life, again, use +Mathematica, it's your friend. + +The result is much +more palatable. + +It's t-- again, for the +energy greater than v0-- + +is equal to, still long. + +But 1 plus 1 over 4 epsilon, +epsilon minus 1 sine + +squared of g0 square +root of epsilon minus 1. + +And upstairs is a one. + +So remember this is only +valid for e greater than v0, + +or equivalently, +epsilon greater than 1. + +And I guess we can +put an equal in. + +So when you get an +expression like this, + +this is as easy as you're +going to make this expression. + +It's not going to +get any easier. + +It's 1 over a sine +times a function plus 1. + +There's really no great +way to simplify this. + +So what you need when you +get an expression like this + +is try to figure out +what it's telling you. + +The useful thing to +do is to plot it. + +So let's just look +at this function + +and see what it's telling us. + +Let's plot this t as +a function of epsilon + +and for some fixed g0. + +Keep in mind that this only +makes sense for e greater + +than v0 or for epsilon +greater than 1, so here's 1. + +And we're going +to remain agnostic + +as to what happens below 1. + +And just for normalization, +we know that the transmission + +probability can never +be greater than 1, + +so it's got to be +between 1 and 0. + +So here's 0 and 0. + +We're remaining agnostic +about this for the moment. + +So let's start thinking about +what this plot looks like. + +First off, what does +it look like at 1? + +So when epsilon +goes to 1, this is + +going to 0, that's bad +because it's in a denominator. + +But upstairs, this +is going to 0, + +and sine squared of something +when it's becoming small + +goes like-- well, sine +goes like that thing. + +So sine squared goes like +this quantity squared. + +So sine squared goes +like g0 squared, + +this goes like 1 +over-- this is going + +like g0 squared epsilon +minus 1 square root quantity + +squared, which is +epsilon minus 1. + +So this is going to 0 and +this, the denominator, + +is going to 0 exactly +in the same way. + +Epsilon minus 1 from +here, epsilon minus 1 + +downstairs from here. + +So the epsilon minus +ones precisely cancel. + +From the sine squared +we get a g0 squared, + +and from here we +get a 4 epsilon. + +So we get 1 plus g0 +squared over 4 epsilon. + +But 4 epsilon, what +was epsilon here? + +1. + +We're looking at +epsilon goes to 1, + +so this is just +g0 squared over 4. + +So the height, the value of t-- +so we're not looking in here. + +But at energy is equal to +v0 or epsilon is equal to 1, + +we know that the transmission +amplitude is not 0, + +but it's also strictly +smaller than 1. + +Which is good, +because if it were 6, + +you'd be really worried. + +So g0 squared, if g0 squared +is 0, what do we get? + +1. + +Fantastic, there's no barrier. + +We just keep right on going +through, perfect transmission. + +If g0 is not zero, however, +the transmission is suppressed. + +Like 1 over g0 squared. + +What does this actually +look like with some value. + +And what is this value, +it's just 1 over 1 + +plus 1/4 g0 squared. + +Cool? + +OK. + +And now what +happens, for example, + +for a very large epsilon? + +Well, when epsilon is gigantic, +sine squared of this-- well, + +sine squared is +oscillating rapidly, + +so that's kind of worrying. + +If this is very, +very large, this + +is a rapidly +oscillating function. + +However, it's being divided +by roughly epsilon squared. + +So something that goes between +0 and 1 divided by epsilon + +squared, as epsilon +gets large, becomes 0. + +And so we get 1 over +1 plus 0, we get 1. + +So for very large values +it's asymptoting to 1. + +So naively, it's going to +do something like this. + +However, there's +this sine squared. + +And in fact, this +is exactly what + +it would do if we just had +the 1 over epsilon times + +some constant. + +But in fact, we have +the sine squared, + +and the sine squared +is making it wiggle. + +And the frequency +of the wiggle is g0, + +except that it's not +linear in epsilon, + +it's linear in square +root of epsilon. + +So as epsilon gets larger, +the square root of epsilon + +is getting larger +less than linearly. + +So what that's telling you is +if you looked at root epsilon, + +you would see it +with even period. + +But we don't have +root epsilon, we're + +plugging this as a +function of epsilon. + +So it's not even period, +it's getting wider and wider. + +Meanwhile, there's a +nice fact about this. + +For special values of epsilon, +what happens to sine squared? + +It goes to zero. + +And what happens +when this is zero? + +Yeah, t is 1. + +So every time sine is 0, +i.e., for sufficient values + +when root epsilon is a multiple +of pi determined by g0, + +transmission goes to 1. + +It becomes perfect. + +So in fact, instead +of doing-- wow. + +Instead of doing this, what +it does is it does this. + +So let's check that +I'm not lying to you. + +So let me draw it +slightly different. + +To check, so it's going to +0, and the period of the 0 + +is getting further +and further along. + +That's because this is +square root, not squared. + +So epsilon has to get much +larger to hit the next period. + +That's why it's getting +larger and larger spacing. + +However, the amplitude +goes down from 1, + +that's when this gets largest. + +Well, at large values of +epsilon, this is suppressed. + +As epsilon goes +larger and larger, + +this deviation become +smaller and smaller. + +So that's what this +plot is telling us. + +This plot is telling +us a bunch of things. + +First off, we see that +at large energies, + +we transmit perfectly. + +That makes sense. + +This was a finitely +high barrier. + +Large energies, we +don't even notice it. + +It tells you at low +energies-- well, + +we don't know yet what +happens at very low energies. + +But at reasonably low energies, +the transmission is suppressed. + +And if you sort of +squint, this roughly + +does what we'd expect +from the step barrier. + +However, something +really special + +is happening at special +values of epsilon. + +We're getting +perfect transmission. + +We get perfect transmission of +these points, t is equal to 1. + +Perfect. + +Star. + +Happy with a big nose. + +I don't know. + +Perfect transmission +at all these points. + +So this leaves us with +a question of why. + +Why the perfect +transmission, what's + +the mechanism making +transmission perfect. + +But it also does something +really lovely for us. + +Suppose you see a spectrum, you +see a transmission amplitude + +or transmission probability +that looks like this. + +You may get crappy data. + +You may see that +it's smudged out + +and you see all +sorts of messy stuff. + +But if you know that +there's perfect transmission + +at some particular +epsilon 1, there's + +more perfect transmission at +another epsilon 2, more perfect + +transmission at +epsilon 3, and they + +scale, they fit to +this prediction. + +What do you know? + +That you've got a +finite high barrier, + +and it's probably pretty well +approximated by a square step. + +So in your problem set, you're +going to get experimental data, + +and you're going to have to +match to the experimental data. + +You're going to have +to predict something + +about the potential that created +a particular transmission + +probability distribution. + +And knowing where +these resonances are, + +where these points of +perfect transmission, + +is going to be very +useful for you. + +Yeah. + +AUDIENCE: Wasn't there +another potential + +that will also +create periodic 1s? + +PROFESSOR: A very good question. + +So I'm going to turn +that around to you. + +Can you orchestrate a potential +that gives you the same thing? + +That's an interesting +empirical question. + +So, on the problem set, you'll +study a double well potential. + +So the question +was, how do I know + +isn't another potential that +gives me the same answer? + +At this point, we don't know. + +Maybe there is +another potential. + +In fact, you can do +all sorts of things + +to make a potential that's +very arbitrarily close that + +gives you an arbitrarily +similar profile. + +So if they're +significantly different, + +how different do they look? + +So then the students +say, well, I don't know. + +What about a double +well potential? + +So, in fact, we'll be doing +a double well potential + +on the problem set. + +A good question. + +And we certainly +haven't proven anything + +like this is the +only potentially + +that gives you this +transmission amplitude. + +What we can say is if you get +transmission amplitude that + +looks like this, it's +probably pretty reasonable + +to say it's probably +well modeled. + +We seem to be reproducing +the data reasonably well. + +So it's not a proof of +anything, but it's a nice model. + +And we're physicists, +we build models. + +We don't tell you +what's true, we + +tell you what are good models. + +If a theorist ever +walks up on you + +and he says, here's the +truth, punch him in the gut. + +That's not how it works. + +Experimentalists, +on the other hand. + +We'll just punch +them too, I guess. + +[LAUGHTER] + +PROFESSOR: We build models. + +OK, so this leaves us +with an obvious question, + +which we've answer +in the case of energy + +grade in the potential. + +What about the case of the +energy less than the potential. + +So we haven't filled out +that part of the graph. + +Let's fill out that +part of the graph. + +What happens if the energy +is less than the potential? + +And for this, I'm going to +use the trick that I mentioned + +earlier that, look, +if the energy is + +less than the potential, +that just means that + +in the intervening +regime, in here, + +instead of being +oscillatory, it's + +going to be exponentially +growing [INAUDIBLE] + +because we're in a +classically disallowed region. + +So if the energy +is less than v0, + +here we have instead of +ikx, we have minus alpha x. + +And instead of minus ikx +we have plus alpha x. + +So if you go through +that whole analysis + +and plug in those values for +the k prime, the answer you get + +is really quite nice. + +We find that t for energy +less than v0 is equal to-- + +and it's just a direct +analytic continuation of what + +you get here-- 1 plus 1 over +4 epsilon 1 minus epsilon. + +So epsilon is less than 1 now. + +1 sinh squared of g0 1 +minus epsilon under 1. + +OK, so now this lets +us complete the plot. + +And you can check, it's +pretty straightforward, + +that because sinh, again, +goes like its argument + +at very small values +of its argument, + +we get g0 squared +1 minus epsilon. + +Sorry, this should be +square root 1 minus epsilon. + +Really? + +Is that a typo? + +Oh no, it's in there. + +OK, good. + +So again, we get g0 +squared 1 minus epsilon, + +the 1 minus epsilon cancels, +and we get 1 over 4 g0 squared. + +Which is good, because +if they disagreed, + +we'd be in real trouble. + +So they agree, but the sinh +squared is just a strictly-- + +or that function is just +a strictly decreasing + +function as we approach +epsilon goes to 0. + +It goes mostly to 0. + +So this is what we see. + +We see an exponential +region and then + +we see oscillations +with residences + +where the period is +getting wider and wider. + +But this should trouble +you a little bit. + +Here, what are we saying? + +We're saying look, +if we have a barrier, + +and we send in a +particle with energy way + +below the barrier, +that's kind of troubling. + +If we send in a particle with +energy way below the barrier, + +there's some probability +that it gets out. + +It goes across. + +So for e less than v0, +classically no transmission, + +we get transmission. + +Now, do we get resonances +when e is less than v0? + +No, that's an interesting thing. + +We'll talk about resonances +and where they come from, + +and we'll talk about the more +generalized notion of a nest + +matrix in the next lecture. + +But for now I just want to say +a couple of things about it. + +So I want to ask-- so +this is called tunneling, + +this transmission across +a disallowed barrier, + +a classically +disallowed barrier-- + +so this transmission +across a disallowed barrier + +is called tunneling. + +And just a quick thing to notice +is that if we hold e fixed + +and we vary l, we vary +the width of the barrier, + +how does the tunneling +amplitude depend + +on the width of the barrier? + +At fixed energy, if we vary the +width of the barrier-- which + +is only contained +in g0-- how does + +the transmission amplitude vary? + +And we find that for large +l-- for l much greater than 1 + +for a typical scale +in the problem-- + +the tunneling amplitude goes +like e to the minus 2 alpha l + +where alpha just depends on +the energy in the potential. + +So what we see is that the +probability of transmitting, + +of tunneling through +a wall, depends + +on the width of that wall. + +And it depends on +it exponentially. + +The wider the wall, the +exponentially less likely you + +are to tunnel across it. + +And this fits the +simulation we ran + +where we saw that tunnelling +through a very thin wall + +was actually quite efficient. + +And we also saw that +tunnelling across a wall + +can have resonant peaks. + +At special values, it +transmits perfectly. + +We saw that in the simulations. + +So at this point I can't resist +telling you a very short story. + +I have a very good friend +who is not a physicist, + +but who is a professor at MIT. + +So a smart person, +and very smart. + +She's one of the +smartest people I know. + +She broke her ankle. + +She's always losing stuff, +she's constantly losing stuff. + +And she broke her ankle, and she +was going to the rehab place, + +and she parked her car right +in front of the rehab place. + +She parked her +car right in front + +because she's got +the broken ankle + +and she doesn't want to have to +walk a long way to get the car, + +she parked right in front. + +She went in, she did +her two hours of rehab, + +and she came outside, +and her car was gone. + +And she's always +misplacing her car, + +she's always +misplacing her keys, + +she's always losing everything. + +But this time, this time +she knew where it was. + +And it wasn't there. + +So first she thought, oh +crap, my car's been stolen. + +How annoying, I've +got a broken ankle. + +But she looks +around, and there's + +her car on the other side +of the street pointed + +the opposite direction. + +And she's like, finally. + +Finally. + +She was explaining this to +me and a friend of mine who + +is also a physicist, +she said finally, I + +knew I had incontrovertible +proof that quantum + +effects happen to +macroscopic objects. + +My car tunnelled +across the street. + +[LAUGHTER] + +PROFESSOR: At this +point, of course, + +my friend and I are +just dying of laughter. + +But she said my car +tunnelled across the street. + +But here's the problem, +I couldn't tell anyone. + +Because if I told anyone, they +would know that I was crazy. + +Clearly I'm crazy, because I +lose my stuff all the time, + +but surely it's just +gotten misplaced. + +So I went home, and +I got home and I + +was sitting down to dinner with +my partner and our daughter + +and I was burning up +inside because I wanted + +to tell them this +crazy thing happened. + +I know quantum +mechanics, it happens. + +I couldn't tell them +anything, so I was just + +fidgeting and dying. + +And finally my +daughter said, mom, + +didn't you notice that we moved +the car across the street? + +[LAUGHTER] + +PROFESSOR: See you next time. \ No newline at end of file diff --git a/TOLwmtn8Miw.txt b/TOLwmtn8Miw.txt new file mode 100644 index 0000000000000000000000000000000000000000..ce46fd0096c5533cfc55f8c7fd90d60fd63b1b51 --- /dev/null +++ b/TOLwmtn8Miw.txt @@ -0,0 +1,16712 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% 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+ + align:start position:0% +Horrors + + + align:start position:0% +Horrors +well when I went to graduate school it + + align:start position:0% +well when I went to graduate school it + + + align:start position:0% +well when I went to graduate school it +was at + + align:start position:0% +was at + + + align:start position:0% +was at +Princeton in the math + + align:start position:0% +Princeton in the math + + + align:start position:0% +Princeton in the math +department + + align:start position:0% +department + + + align:start position:0% +department +and there were all sorts of courses + + align:start position:0% +and there were all sorts of courses + + + align:start position:0% +and there were all sorts of courses +given + + align:start position:0% +given + + + align:start position:0% +given +by very good professors because I think + + align:start position:0% +by very good professors because I think + + + align:start position:0% +by very good professors because I think +I've mentioned this this + + align:start position:0% +I've mentioned this this + + + align:start position:0% +I've mentioned this this +is sort of + + align:start position:0% +is sort of + + + align:start position:0% +is sort of +1950 and the + + align:start position:0% +1950 and the + + + align:start position:0% +1950 and the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +universities in the United States were + + align:start position:0% +universities in the United States were + + + align:start position:0% +universities in the United States were +uh at least the science departments were + + align:start position:0% +uh at least the science departments were + + + align:start position:0% +uh at least the science departments were +filled with great mathematicians and + + align:start position:0% +filled with great mathematicians and + + + align:start position:0% +filled with great mathematicians and +physicists and people like that who had + + align:start position:0% +physicists and people like that who had + + + align:start position:0% +physicists and people like that who had +been + + align:start position:0% +been + + + align:start position:0% +been +uh extracted from Europe because of + + align:start position:0% +uh extracted from Europe because of + + + align:start position:0% +uh extracted from Europe because of +World War II + + align:start position:0% +World War II + + + align:start position:0% +World War II +and + + align:start position:0% +and + + + align:start position:0% +and +uh the masterart department at + + align:start position:0% +uh the masterart department at + + + align:start position:0% +uh the masterart department at +Princeton was very very very exciting + + align:start position:0% +Princeton was very very very exciting + + + align:start position:0% +Princeton was very very very exciting +because of + + align:start position:0% + + + + align:start position:0% + +the if you had a question + + align:start position:0% +the if you had a question + + + align:start position:0% +the if you had a question +you you had a very good chance that the + + align:start position:0% +you you had a very good chance that the + + + align:start position:0% +you you had a very good chance that the +uh world's leading Authority on that + + align:start position:0% +uh world's leading Authority on that + + + align:start position:0% +uh world's leading Authority on that +subject would would be in the next room + + align:start position:0% +subject would would be in the next room + + + align:start position:0% +subject would would be in the next room +or two I was interested in the theory of + + align:start position:0% +or two I was interested in the theory of + + + align:start position:0% +or two I was interested in the theory of +knots and there was + + align:start position:0% +knots and there was + + + align:start position:0% +knots and there was +Professor Ralph Fox who was uh one of + + align:start position:0% +Professor Ralph Fox who was uh one of + + + align:start position:0% +Professor Ralph Fox who was uh one of +the world's experts on not + + align:start position:0% +the world's experts on not + + + align:start position:0% +the world's experts on not +Theory and in fact he was so good at it + + align:start position:0% +Theory and in fact he was so good at it + + + align:start position:0% +Theory and in fact he was so good at it +that I gave + + align:start position:0% + + + + align:start position:0% + +up which is nice important thing to keep + + align:start position:0% +up which is nice important thing to keep + + + align:start position:0% +up which is nice important thing to keep +in mind always be ready to give up if + + align:start position:0% +in mind always be ready to give up if + + + align:start position:0% +in mind always be ready to give up if +there's someone doing something better + + align:start position:0% +there's someone doing something better + + + align:start position:0% +there's someone doing something better +than you and find the right Niche but + + align:start position:0% +than you and find the right Niche but + + + align:start position:0% +than you and find the right Niche but +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +um they had courses + + align:start position:0% +um they had courses + + + align:start position:0% +um they had courses +and you would register for courses and + + align:start position:0% +and you would register for courses and + + + align:start position:0% +and you would register for courses and +everyone got an A in all + + align:start position:0% +everyone got an A in all + + + align:start position:0% +everyone got an A in all +courses I'm sorry there were no grades + + align:start position:0% +courses I'm sorry there were no grades + + + align:start position:0% +courses I'm sorry there were no grades +uh when I got + + align:start position:0% +uh when I got + + + align:start position:0% +uh when I got +there um because Professor lefets didn't + + align:start position:0% +there um because Professor lefets didn't + + + align:start position:0% +there um because Professor lefets didn't +like the IDE of grading + + align:start position:0% +like the IDE of grading + + + align:start position:0% +like the IDE of grading +people and his he was head of the + + align:start position:0% +people and his he was head of the + + + align:start position:0% +people and his he was head of the +department and his feeling was + + align:start position:0% +department and his feeling was + + + align:start position:0% +department and his feeling was +that if somebody wasn't doing good work + + align:start position:0% +that if somebody wasn't doing good work + + + align:start position:0% +that if somebody wasn't doing good work +then it wasn't n that person's fault it + + align:start position:0% +then it wasn't n that person's fault it + + + align:start position:0% +then it wasn't n that person's fault it +was the fault of the admissions + + align:start position:0% +was the fault of the admissions + + + align:start position:0% +was the fault of the admissions +committee and if + + align:start position:0% +committee and if + + + align:start position:0% +committee and if +anybody got through the hurdles to get + + align:start position:0% +anybody got through the hurdles to get + + + align:start position:0% +anybody got through the hurdles to get +there then they + + align:start position:0% +there then they + + + align:start position:0% +there then they +were uh assumed to be mathematicians and + + align:start position:0% +were uh assumed to be mathematicians and + + + align:start position:0% +were uh assumed to be mathematicians and +that was that and uh but after a couple + + align:start position:0% +that was that and uh but after a couple + + + align:start position:0% +that was that and uh but after a couple +of years the Provost of the + + align:start position:0% +of years the Provost of the + + + align:start position:0% +of years the Provost of the +University uh got annoyed with the math + + align:start position:0% +University uh got annoyed with the math + + + align:start position:0% +University uh got annoyed with the math +department and he sent down a message + + align:start position:0% +department and he sent down a message + + + align:start position:0% +department and he sent down a message +that there would have to be grades in + + align:start position:0% +that there would have to be grades in + + + align:start position:0% +that there would have to be grades in +Rec course and lefet said + + align:start position:0% +Rec course and lefet said + + + align:start position:0% +Rec course and lefet said +okay uh he didn't believe in fighting + + align:start position:0% +okay uh he didn't believe in fighting + + + align:start position:0% +okay uh he didn't believe in fighting +when there was a good + + align:start position:0% +when there was a good + + + align:start position:0% +when there was a good +alternative the alternative was + + align:start position:0% +alternative the alternative was + + + align:start position:0% +alternative the alternative was +everybody got A's in every course + + align:start position:0% +everybody got A's in every course + + + align:start position:0% +everybody got A's in every course +whether they took the course or + + align:start position:0% +whether they took the course or + + + align:start position:0% +whether they took the course or +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +not and + + align:start position:0% + + + + align:start position:0% + +uh I think the end of the story is that + + align:start position:0% +uh I think the end of the story is that + + + align:start position:0% +uh I think the end of the story is that +when he + + align:start position:0% +when he + + + align:start position:0% +when he +retired the new chairman wasn't as good + + align:start position:0% +retired the new chairman wasn't as good + + + align:start position:0% +retired the new chairman wasn't as good +at evading the authorities + + align:start position:0% +at evading the authorities + + + align:start position:0% +at evading the authorities +but so I have a little discomfort at + + align:start position:0% +but so I have a little discomfort at + + + align:start position:0% +but so I have a little discomfort at +grades myself and when I gave this + + align:start position:0% + + + + align:start position:0% + +course in the 60s and SE in the + + align:start position:0% +course in the 60s and SE in the + + + align:start position:0% +course in the 60s and SE in the +70s uh everybody got an A and it took + + align:start position:0% +70s uh everybody got an A and it took + + + align:start position:0% +70s uh everybody got an A and it took +several years for the Departments to + + align:start position:0% +several years for the Departments to + + + align:start position:0% +several years for the Departments to +notice + + align:start position:0% + + + + align:start position:0% + +anyway so any so we have to give + + align:start position:0% +anyway so any so we have to give + + + align:start position:0% +anyway so any so we have to give +grades + + align:start position:0% + + + + align:start position:0% + +MIT but all that's great fun uh + + align:start position:0% +MIT but all that's great fun uh + + + align:start position:0% +MIT but all that's great fun uh +anybody what didn't we cover in this + + align:start position:0% +anybody what didn't we cover in this + + + align:start position:0% +anybody what didn't we cover in this +course that you wish it we had and uh + + align:start position:0% +course that you wish it we had and uh + + + align:start position:0% +course that you wish it we had and uh +I'd like to know what some of you are + + align:start position:0% +I'd like to know what some of you are + + + align:start position:0% +I'd like to know what some of you are +doing also what's uh what's your plan to + + align:start position:0% +doing also what's uh what's your plan to + + + align:start position:0% +doing also what's uh what's your plan to +make machines smarter in the + + align:start position:0% +make machines smarter in the + + + align:start position:0% +make machines smarter in the +future + + align:start position:0% + + + + align:start position:0% + +and how hard is it to find a job where + + align:start position:0% +and how hard is it to find a job where + + + align:start position:0% +and how hard is it to find a job where +you can do + + align:start position:0% +you can do + + + align:start position:0% +you can do +research I've I haven't tried getting a + + align:start position:0% +research I've I haven't tried getting a + + + align:start position:0% +research I've I haven't tried getting a +new job for a long + + align:start position:0% + + + + align:start position:0% + +time I just tried to hire a former + + align:start position:0% +time I just tried to hire a former + + + align:start position:0% +time I just tried to hire a former +student but he's starting a huge start + + align:start position:0% +student but he's starting a huge start + + + align:start position:0% +student but he's starting a huge start +up and um if you can't find a job I + + align:start position:0% +up and um if you can't find a job I + + + align:start position:0% +up and um if you can't find a job I +guess you can make one if you can full + + align:start position:0% +guess you can make one if you can full + + + align:start position:0% +guess you can make one if you can full +enough investors + + align:start position:0% +enough investors + + + align:start position:0% +enough investors +into supporting a new + + align:start position:0% + + + + align:start position:0% + +operation do is design around a very + + align:start position:0% +operation do is design around a very + + + align:start position:0% +operation do is design around a very +specific problem design what around a + + align:start position:0% +specific problem design what around a + + + align:start position:0% +specific problem design what around a +very specific problem so you're + + align:start position:0% +very specific problem so you're + + + align:start position:0% +very specific problem so you're +addressing getting a machine to solve + + align:start position:0% +addressing getting a machine to solve + + + align:start position:0% +addressing getting a machine to solve +some particular problem which is always + + align:start position:0% +some particular problem which is always + + + align:start position:0% +some particular problem which is always +there's always a fast path to that by + + align:start position:0% +there's always a fast path to that by + + + align:start position:0% +there's always a fast path to that by +finding the right set of data and + + align:start position:0% +finding the right set of data and + + + align:start position:0% +finding the right set of data and +finding the right model that will work + + align:start position:0% +finding the right model that will work + + + align:start position:0% +finding the right model that will work +reasonably + + align:start position:0% +reasonably + + + align:start position:0% +reasonably +well it's not + + align:start position:0% +well it's not + + + align:start position:0% +well it's not +really like a business yes case that can + + align:start position:0% +really like a business yes case that can + + + align:start position:0% +really like a business yes case that can +be made for making a general + + align:start position:0% +be made for making a general + + + align:start position:0% +be made for making a general +intelligence + + align:start position:0% +intelligence + + + align:start position:0% +intelligence +in when there's motivation some specific + + align:start position:0% +in when there's motivation some specific + + + align:start position:0% +in when there's motivation some specific +application + + align:start position:0% +application + + + align:start position:0% +application +something that's right and + + align:start position:0% + + + + align:start position:0% + +the goes back to World War II again the + + align:start position:0% +the goes back to World War II again the + + + align:start position:0% +the goes back to World War II again the +the reason + + align:start position:0% +the reason + + + align:start position:0% +the reason +we could do so much in those early years + + align:start position:0% +we could do so much in those early years + + + align:start position:0% +we could do so much in those early years +about General theories was + + align:start position:0% +about General theories was + + + align:start position:0% +about General theories was +that + + align:start position:0% + + + + align:start position:0% + +uh the defense department had cre + + align:start position:0% +uh the defense department had cre + + + align:start position:0% +uh the defense department had cre +created this uh + + align:start position:0% + + + + align:start position:0% + +new Wing called arpa Advanced research + + align:start position:0% +new Wing called arpa Advanced research + + + align:start position:0% +new Wing called arpa Advanced research +projects + + align:start position:0% +projects + + + align:start position:0% +projects +agency and I actually don't know what + + align:start position:0% +agency and I actually don't know what + + + align:start position:0% +agency and I actually don't know what +caused it to to begin but uh a lot of it + + align:start position:0% +caused it to to begin but uh a lot of it + + + align:start position:0% +caused it to to begin but uh a lot of it +was involved + + align:start position:0% +was involved + + + align:start position:0% +was involved +with uh trying to make new kinds of + + align:start position:0% +with uh trying to make new kinds of + + + align:start position:0% +with uh trying to make new kinds of +instruments to detect InterContinental + + align:start position:0% +instruments to detect InterContinental + + + align:start position:0% +instruments to detect InterContinental +missiles and uh heaven knows what else + + align:start position:0% +missiles and uh heaven knows what else + + + align:start position:0% +missiles and uh heaven knows what else +but + + align:start position:0% +but + + + align:start position:0% +but +uh they decided to have a basic research + + align:start position:0% +uh they decided to have a basic research + + + align:start position:0% +uh they decided to have a basic research +Branch to uh because if you're in the + + align:start position:0% +Branch to uh because if you're in the + + + align:start position:0% +Branch to uh because if you're in the +military one of your concerns is defense + + align:start position:0% +military one of your concerns is defense + + + align:start position:0% +military one of your concerns is defense +and for some reason that uh I + + align:start position:0% +and for some reason that uh I + + + align:start position:0% +and for some reason that uh I +don't know how to I don't know how to + + align:start position:0% +don't know how to I don't know how to + + + align:start position:0% +don't know how to I don't know how to +explain but a group of people in the + + align:start position:0% +explain but a group of people in the + + + align:start position:0% +explain but a group of people in the +Office of Naval Research + + align:start position:0% +Office of Naval Research + + + align:start position:0% +Office of Naval Research +uh concluded + + align:start position:0% +uh concluded + + + align:start position:0% +uh concluded +that the best defense is to be way ahead + + align:start position:0% +that the best defense is to be way ahead + + + align:start position:0% +that the best defense is to be way ahead +in + + align:start position:0% +in + + + align:start position:0% +in +technology of everyone else and since + + align:start position:0% +technology of everyone else and since + + + align:start position:0% +technology of everyone else and since +there were no particular constraints on + + align:start position:0% +there were no particular constraints on + + + align:start position:0% +there were no particular constraints on +them they didn't have to + + align:start position:0% +them they didn't have to + + + align:start position:0% +them they didn't have to +say uh you have to write a progress + + align:start position:0% +say uh you have to write a progress + + + align:start position:0% +say uh you have to write a progress +report every three months and stuff like + + align:start position:0% +report every three months and stuff like + + + align:start position:0% +report every three months and stuff like +that + + align:start position:0% +that + + + align:start position:0% +that +uh so + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +anyway another unique thing about the + + align:start position:0% +anyway another unique thing about the + + + align:start position:0% +anyway another unique thing about the +situation when I started was that the + + align:start position:0% +situation when I started was that the + + + align:start position:0% +situation when I started was that the +students knew more than the professors + + align:start position:0% +students knew more than the professors + + + align:start position:0% +students knew more than the professors +about computer + + align:start position:0% +about computer + + + align:start position:0% +about computer +science uh now there were a couple of + + align:start position:0% +science uh now there were a couple of + + + align:start position:0% +science uh now there were a couple of +there were people around uh MIT who knew + + align:start position:0% +there were people around uh MIT who knew + + + align:start position:0% +there were people around uh MIT who knew +about + + align:start position:0% +about + + + align:start position:0% +about +computers but uh we had the bad luck of + + align:start position:0% +computers but uh we had the bad luck of + + + align:start position:0% +computers but uh we had the bad luck of +having the best analog computers in the + + align:start position:0% +having the best analog computers in the + + + align:start position:0% +having the best analog computers in the +world uh vavar Bush and people like that + + align:start position:0% +world uh vavar Bush and people like that + + + align:start position:0% +world uh vavar Bush and people like that +uh so when things change suddenly enough + + align:start position:0% +uh so when things change suddenly enough + + + align:start position:0% +uh so when things change suddenly enough +uh your best people might be turn out to + + align:start position:0% +uh your best people might be turn out to + + + align:start position:0% +uh your best people might be turn out to +be the worst for a few years and the + + align:start position:0% +be the worst for a few years and the + + + align:start position:0% +be the worst for a few years and the +leaders in Innovation uh came from the + + align:start position:0% +leaders in Innovation uh came from the + + + align:start position:0% +leaders in Innovation uh came from the +tech Model Railroad Club and a few uh + + align:start position:0% +tech Model Railroad Club and a few uh + + + align:start position:0% +tech Model Railroad Club and a few uh +institutions like that uh I + + align:start position:0% +institutions like that uh I + + + align:start position:0% +institutions like that uh I +certainly knew something about + + align:start position:0% +certainly knew something about + + + align:start position:0% +certainly knew something about +computers at least the theory of + + align:start position:0% +computers at least the theory of + + + align:start position:0% +computers at least the theory of +them uh but I didn't know anything about + + align:start position:0% +them uh but I didn't know anything about + + + align:start position:0% +them uh but I didn't know anything about +modern programming and either did anyone + + align:start position:0% +modern programming and either did anyone + + + align:start position:0% +modern programming and either did anyone +else except Newell and Simon and + + align:start position:0% +else except Newell and Simon and + + + align:start position:0% +else except Newell and Simon and +Carnegie melan and John McCarthy + + align:start position:0% +Carnegie melan and John McCarthy + + + align:start position:0% +Carnegie melan and John McCarthy +who uh they invented list processing + + align:start position:0% +who uh they invented list processing + + + align:start position:0% +who uh they invented list processing +languages and John McCarthy refined them + + align:start position:0% +languages and John McCarthy refined them + + + align:start position:0% +languages and John McCarthy refined them +and uh basically combined a very clumsy + + align:start position:0% +and uh basically combined a very clumsy + + + align:start position:0% +and uh basically combined a very clumsy +logol likee list processing + + align:start position:0% +logol likee list processing + + + align:start position:0% +logol likee list processing +language uh with + + align:start position:0% +language uh with + + + align:start position:0% +language uh with +uh with a + + align:start position:0% +uh with a + + + align:start position:0% +uh with a +algebraic language and + + align:start position:0% + + + + align:start position:0% + +uh so lisp came after uh there had been + + align:start position:0% +uh so lisp came after uh there had been + + + align:start position:0% +uh so lisp came after uh there had been +A Primitive list processors and all of + + align:start position:0% +A Primitive list processors and all of + + + align:start position:0% +A Primitive list processors and all of +new and Simon's work including a chess + + align:start position:0% +new and Simon's work including a chess + + + align:start position:0% +new and Simon's work including a chess +program had been done with + + align:start position:0% +program had been done with + + + align:start position:0% +program had been done with +uh just a programming language that had + + align:start position:0% +uh just a programming language that had + + + align:start position:0% +uh just a programming language that had +something like car cter and cons so that + + align:start position:0% + + + + align:start position:0% + +was U so it was about 10 years + + align:start position:0% +was U so it was about 10 years + + + align:start position:0% +was U so it was about 10 years +after uh the + + align:start position:0% +after uh the + + + align:start position:0% +after uh the +be the first computers in at MIT came + + align:start position:0% +be the first computers in at MIT came + + + align:start position:0% +be the first computers in at MIT came +mainly from Lincoln lab who had the job + + align:start position:0% +mainly from Lincoln lab who had the job + + + align:start position:0% +mainly from Lincoln lab who had the job +of building supercomputers to uh analyze + + align:start position:0% +of building supercomputers to uh analyze + + + align:start position:0% +of building supercomputers to uh analyze +radar data and stuff like that uh which + + align:start position:0% +radar data and stuff like that uh which + + + align:start position:0% +radar data and stuff like that uh which +were indeed connected with National + + align:start position:0% +were indeed connected with National + + + align:start position:0% +were indeed connected with National +Defense and uh try to get combined radar + + align:start position:0% +Defense and uh try to get combined radar + + + align:start position:0% +Defense and uh try to get combined radar +reports from all sorts of places to uh + + align:start position:0% +reports from all sorts of places to uh + + + align:start position:0% +reports from all sorts of places to uh +get early warnings of uh activities in + + align:start position:0% +get early warnings of uh activities in + + + align:start position:0% +get early warnings of uh activities in +space and so forth um + + align:start position:0% +space and so forth um + + + align:start position:0% +space and so forth um +when the first Sputnik was launched for + + align:start position:0% +when the first Sputnik was launched for + + + align:start position:0% +when the first Sputnik was launched for +by the Russians there was just a little + + align:start position:0% +by the Russians there was just a little + + + align:start position:0% +by the Russians there was just a little +thing going beep beep beep in low earth + + align:start position:0% +thing going beep beep beep in low earth + + + align:start position:0% +thing going beep beep beep in low earth +orbit and + + align:start position:0% + + + + align:start position:0% + +uh within a couple of hours of + + align:start position:0% +uh within a couple of hours of + + + align:start position:0% +uh within a couple of hours of +after uh the Russians announced that + + align:start position:0% +after uh the Russians announced that + + + align:start position:0% +after uh the Russians announced that +Sputnik was + + align:start position:0% +Sputnik was + + + align:start position:0% +Sputnik was +there uh and they announced its orbit + + align:start position:0% +there uh and they announced its orbit + + + align:start position:0% +there uh and they announced its orbit +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the a couple of hackers at Lincoln + + align:start position:0% +the a couple of hackers at Lincoln + + + align:start position:0% +the a couple of hackers at Lincoln +laboratory uh managed + + align:start position:0% +laboratory uh managed + + + align:start position:0% +laboratory uh managed +to uh track The Thing + + align:start position:0% +to uh track The Thing + + + align:start position:0% +to uh track The Thing +by hooking a couple of radio it was + + align:start position:0% +by hooking a couple of radio it was + + + align:start position:0% +by hooking a couple of radio it was +going beep beep beep and they guy named + + align:start position:0% +going beep beep beep and they guy named + + + align:start position:0% +going beep beep beep and they guy named +Brad Howland who was a teenager I think + + align:start position:0% +Brad Howland who was a teenager I think + + + align:start position:0% +Brad Howland who was a teenager I think +then hooked a couple of radio receivers + + align:start position:0% +then hooked a couple of radio receivers + + + align:start position:0% +then hooked a couple of radio receivers +up with some flip-flops and things and + + align:start position:0% +up with some flip-flops and things and + + + align:start position:0% +up with some flip-flops and things and +uh was able to get its exact traj trory + + align:start position:0% +uh was able to get its exact traj trory + + + align:start position:0% +uh was able to get its exact traj trory +from the Doppler shifts of + + align:start position:0% + + + + align:start position:0% + +uh anyway + + align:start position:0% + + + + align:start position:0% + +uh then I think I've talked about that + + align:start position:0% +uh then I think I've talked about that + + + align:start position:0% +uh then I think I've talked about that +history at some point + + align:start position:0% +history at some point + + + align:start position:0% +history at some point +about early 1970 or so 10 or 15 years + + align:start position:0% +about early 1970 or so 10 or 15 years + + + align:start position:0% +about early 1970 or so 10 or 15 years +after uh arpa started well the big arpa + + align:start position:0% +after uh arpa started well the big arpa + + + align:start position:0% +after uh arpa started well the big arpa +uh project was called project Mac in + + align:start position:0% +uh project was called project Mac in + + + align:start position:0% +uh project was called project Mac in +1963 and MIT got $3 million a year uh + + align:start position:0% + + + + align:start position:0% + +for Designing and building a time + + align:start position:0% +for Designing and building a time + + + align:start position:0% +for Designing and building a time +sharing system the idea for a time + + align:start position:0% +sharing system the idea for a time + + + align:start position:0% +sharing system the idea for a time +sharing system had bubbled up in a few + + align:start position:0% +sharing system had bubbled up in a few + + + align:start position:0% +sharing system had bubbled up in a few +places but it was mainly uh a couple of + + align:start position:0% +places but it was mainly uh a couple of + + + align:start position:0% +places but it was mainly uh a couple of +other youngsters John McCarthy and + + align:start position:0% +other youngsters John McCarthy and + + + align:start position:0% +other youngsters John McCarthy and +Edward fredkin who uh + + align:start position:0% +Edward fredkin who uh + + + align:start position:0% +Edward fredkin who uh +recognize that if a computer could + + align:start position:0% +recognize that if a computer could + + + align:start position:0% +recognize that if a computer could +compute thousands of operations per + + align:start position:0% +compute thousands of operations per + + + align:start position:0% +compute thousands of operations per +second then it should be able to compute + + align:start position:0% +second then it should be able to compute + + + align:start position:0% +second then it should be able to compute +hundreds of operations per second for + + align:start position:0% +hundreds of operations per second for + + + align:start position:0% +hundreds of operations per second for +tens of people and when it gets to a + + align:start position:0% +tens of people and when it gets to a + + + align:start position:0% +tens of people and when it gets to a +billion operations per second then it + + align:start position:0% +billion operations per second then it + + + align:start position:0% +billion operations per second then it +should be able to compute a million + + align:start position:0% +should be able to compute a million + + + align:start position:0% +should be able to compute a million +operations per second for a thousand + + align:start position:0% +operations per second for a thousand + + + align:start position:0% +operations per second for a thousand +people and so forth and uh MIT was the + + align:start position:0% +people and so forth and uh MIT was the + + + align:start position:0% +people and so forth and uh MIT was the +first place to develop time sharing + + align:start position:0% +first place to develop time sharing + + + align:start position:0% +first place to develop time sharing +system and as I said uh they sent this + + align:start position:0% +system and as I said uh they sent this + + + align:start position:0% +system and as I said uh they sent this +$3 million a year to get that project to + + align:start position:0% +$3 million a year to get that project to + + + align:start position:0% +$3 million a year to get that project to +work and because the guy in charge of + + align:start position:0% +work and because the guy in charge of + + + align:start position:0% +work and because the guy in charge of +that was a former professor of + + align:start position:0% +that was a former professor of + + + align:start position:0% +that was a former professor of +psychology named uh Joe + + align:start position:0% +psychology named uh Joe + + + align:start position:0% +psychology named uh Joe +licklider uh had been a friend of mine + + align:start position:0% +licklider uh had been a friend of mine + + + align:start position:0% +licklider uh had been a friend of mine +when I was an + + align:start position:0% +when I was an + + + align:start position:0% +when I was an +undergraduate uh he added another + + align:start position:0% +undergraduate uh he added another + + + align:start position:0% +undergraduate uh he added another +million dollars a year and uh gave it to + + align:start position:0% +million dollars a year and uh gave it to + + + align:start position:0% +million dollars a year and uh gave it to +us to start the AI + + align:start position:0% +us to start the AI + + + align:start position:0% +us to start the AI +lab and + + align:start position:0% +lab and + + + align:start position:0% +lab and +uh if that ever happens to you uh I hope + + align:start position:0% +uh if that ever happens to you uh I hope + + + align:start position:0% +uh if that ever happens to you uh I hope +it + + align:start position:0% + + + + align:start position:0% + +will anyway uh as I've complained a lot + + align:start position:0% +will anyway uh as I've complained a lot + + + align:start position:0% +will anyway uh as I've complained a lot +during the + + align:start position:0% +during the + + + align:start position:0% +during the +course uh we were able + + align:start position:0% + + + + align:start position:0% + +to sort of do anything we thought was + + align:start position:0% +to sort of do anything we thought was + + + align:start position:0% +to sort of do anything we thought was +possible and we didn't worry about + + align:start position:0% +possible and we didn't worry about + + + align:start position:0% +possible and we didn't worry about +whether it could be done in a year or + + align:start position:0% +whether it could be done in a year or + + + align:start position:0% +whether it could be done in a year or +two or + + align:start position:0% +two or + + + align:start position:0% +two or +20 uh we just had enough money and + + align:start position:0% +20 uh we just had enough money and + + + align:start position:0% +20 uh we just had enough money and +enough uh adventurous people to to just + + align:start position:0% +enough uh adventurous people to to just + + + align:start position:0% +enough uh adventurous people to to just +uh start doing those things so in the + + align:start position:0% +uh start doing those things so in the + + + align:start position:0% +uh start doing those things so in the +very first year uh we had Jim slagel + + align:start position:0% +very first year uh we had Jim slagel + + + align:start position:0% +very first year uh we had Jim slagel +making the program that + + align:start position:0% +making the program that + + + align:start position:0% +making the program that +uh could uh do + + align:start position:0% +uh could uh do + + + align:start position:0% +uh could uh do +integrals at the level of uh that + + align:start position:0% +integrals at the level of uh that + + + align:start position:0% +integrals at the level of uh that +student students in + + align:start position:0% +student students in + + + align:start position:0% +student students in +1801 uh were learning to do uh I think I + + align:start position:0% +1801 uh were learning to do uh I think I + + + align:start position:0% +1801 uh were learning to do uh I think I +mentioned I made the first program that + + align:start position:0% +mentioned I made the first program that + + + align:start position:0% +mentioned I made the first program that +computed derivatives and it was just + + align:start position:0% +computed derivatives and it was just + + + align:start position:0% +computed derivatives and it was just +five or 10 lines of code because it it + + align:start position:0% +five or 10 lines of code because it it + + + align:start position:0% +five or 10 lines of code because it it +said it worked lexically it said if you + + align:start position:0% +said it worked lexically it said if you + + + align:start position:0% +said it worked lexically it said if you +see + + align:start position:0% +see + + + align:start position:0% +see +XY replace it by the symbols + + align:start position:0% +XY replace it by the symbols + + + align:start position:0% +XY replace it by the symbols +xdy plus y + + align:start position:0% +xdy plus y + + + align:start position:0% +xdy plus y +DX and so + + align:start position:0% +DX and so + + + align:start position:0% +DX and so +forth uh that's how you do derivatives + + align:start position:0% +forth uh that's how you do derivatives + + + align:start position:0% +forth uh that's how you do derivatives +where d means derivative and since it's + + align:start position:0% +where d means derivative and since it's + + + align:start position:0% +where d means derivative and since it's +operating on the names of functions then + + align:start position:0% +operating on the names of functions then + + + align:start position:0% +operating on the names of functions then +you just recurse until all the function + + align:start position:0% +you just recurse until all the function + + + align:start position:0% +you just recurse until all the function +names have + + align:start position:0% +names have + + + align:start position:0% +names have +disappeared and + + align:start position:0% +disappeared and + + + align:start position:0% +disappeared and +uh so that was just a page of code and + + align:start position:0% +uh so that was just a page of code and + + + align:start position:0% +uh so that was just a page of code and +then slagel uh who was blind wrote 20 + + align:start position:0% +then slagel uh who was blind wrote 20 + + + align:start position:0% +then slagel uh who was blind wrote 20 +pages of code and uh Joel Moses + + align:start position:0% +pages of code and uh Joel Moses + + + align:start position:0% +pages of code and uh Joel Moses +who what's he now Provost or + + align:start position:0% + + + + align:start position:0% + +he did he retire or go back to work I'm + + align:start position:0% +he did he retire or go back to work I'm + + + align:start position:0% +he did he retire or go back to work I'm +not probably + + align:start position:0% +not probably + + + align:start position:0% +not probably +both uh Institute Professor yep and + + align:start position:0% + + + + align:start position:0% + +uh he mentioned that it took him a very + + align:start position:0% +uh he mentioned that it took him a very + + + align:start position:0% +uh he mentioned that it took him a very +long time to decode slagel's 20 Pages + + align:start position:0% +long time to decode slagel's 20 Pages + + + align:start position:0% +long time to decode slagel's 20 Pages +because since slagel is writing in brail + + align:start position:0% +because since slagel is writing in brail + + + align:start position:0% +because since slagel is writing in brail +uh poor slagel has to understand his + + align:start position:0% +uh poor slagel has to understand his + + + align:start position:0% +uh poor slagel has to understand his +code too and + + align:start position:0% +code too and + + + align:start position:0% +code too and +uh you can't just glance at a page so he + + align:start position:0% +uh you can't just glance at a page so he + + + align:start position:0% +uh you can't just glance at a page so he +wrote this incredibly intricate + + align:start position:0% +wrote this incredibly intricate + + + align:start position:0% +wrote this incredibly intricate +compressed stuff and it had the weird + + align:start position:0% +compressed stuff and it had the weird + + + align:start position:0% +compressed stuff and it had the weird +property that it solved + + align:start position:0% +property that it solved + + + align:start position:0% +property that it solved +integrals it did integrals at just about + + align:start position:0% +integrals it did integrals at just about + + + align:start position:0% +integrals it did integrals at just about +the same speed as good math students so + + align:start position:0% +the same speed as good math students so + + + align:start position:0% +the same speed as good math students so +uh if you gave it an expression with a + + align:start position:0% +uh if you gave it an expression with a + + + align:start position:0% +uh if you gave it an expression with a +couple of signs and cosiness and things + + align:start position:0% +couple of signs and cosiness and things + + + align:start position:0% +couple of signs and cosiness and things +it might take 10 or 15 minutes and uh + + align:start position:0% +it might take 10 or 15 minutes and uh + + + align:start position:0% +it might take 10 or 15 minutes and uh +everybody was very impressed that this + + align:start position:0% +everybody was very impressed that this + + + align:start position:0% +everybody was very impressed that this +computer could keep up with a human but + + align:start position:0% +computer could keep up with a human but + + + align:start position:0% +computer could keep up with a human but +uh of + + align:start position:0% +uh of + + + align:start position:0% +uh of +course + + align:start position:0% +course + + + align:start position:0% +course +that that fact had no meaning whatever + + align:start position:0% +that that fact had no meaning whatever + + + align:start position:0% +that that fact had no meaning whatever +it was just that happened to be how slow + + align:start position:0% +it was just that happened to be how slow + + + align:start position:0% +it was just that happened to be how slow +computers were at that + + align:start position:0% +computers were at that + + + align:start position:0% +computers were at that +time uh the IBM 704 which was I guess we + + align:start position:0% +time uh the IBM 704 which was I guess we + + + align:start position:0% +time uh the IBM 704 which was I guess we +had a 701 and then a 704 + + align:start position:0% +had a 701 and then a 704 + + + align:start position:0% +had a 701 and then a 704 +and I think that machine was uh doing + + align:start position:0% +and I think that machine was uh doing + + + align:start position:0% +and I think that machine was uh doing +about 20,000 operations per second which + + align:start position:0% +about 20,000 operations per second which + + + align:start position:0% +about 20,000 operations per second which +is probably more than a person can do + + align:start position:0% +is probably more than a person can do + + + align:start position:0% +is probably more than a person can do +but no one + + align:start position:0% + + + + align:start position:0% + +knows + + align:start position:0% + + + + align:start position:0% + +well so who has an idea on what what + + align:start position:0% +well so who has an idea on what what + + + align:start position:0% +well so who has an idea on what what +should be done next + + align:start position:0% + + + + align:start position:0% + +yeah what would you like to do uh a + + align:start position:0% +yeah what would you like to do uh a + + + align:start position:0% +yeah what would you like to do uh a +robot + + align:start position:0% + + + + align:start position:0% + +that AI system that would interact + + align:start position:0% + + + + align:start position:0% + +the well we're going to need robots + + align:start position:0% +the well we're going to need robots + + + align:start position:0% +the well we're going to need robots +pretty soon if you look at + + align:start position:0% + + + + align:start position:0% + +the just for example this aging problem + + align:start position:0% +the just for example this aging problem + + + align:start position:0% +the just for example this aging problem +uh We've getting more and more people + + align:start position:0% +uh We've getting more and more people + + + align:start position:0% +uh We've getting more and more people +who are uh + + align:start position:0% + + + + align:start position:0% + +crippled in one way or another + + align:start position:0% +crippled in one way or another + + + align:start position:0% +crippled in one way or another +handicapped + + align:start position:0% +handicapped + + + align:start position:0% +handicapped +uh a huge population of people uh with + + align:start position:0% +uh a huge population of people uh with + + + align:start position:0% +uh a huge population of people uh with +with mild brain disorders of course + + align:start position:0% +with mild brain disorders of course + + + align:start position:0% +with mild brain disorders of course +serious ones + + align:start position:0% +serious ones + + + align:start position:0% +serious ones +also and they're not enough uh nurses to + + align:start position:0% +also and they're not enough uh nurses to + + + align:start position:0% +also and they're not enough uh nurses to +take care of + + align:start position:0% +take care of + + + align:start position:0% +take care of +the U disabled aged + + align:start position:0% +the U disabled aged + + + align:start position:0% +the U disabled aged +people and u i I think that's probably + + align:start position:0% +people and u i I think that's probably + + + align:start position:0% +people and u i I think that's probably +the going to be a + + align:start position:0% +the going to be a + + + align:start position:0% +the going to be a +major need for + + align:start position:0% + + + + align:start position:0% + +robotics as I see it the problem with + + align:start position:0% +robotics as I see it the problem with + + + align:start position:0% +robotics as I see it the problem with +robotics is that people build + + align:start position:0% +robotics is that people build + + + align:start position:0% +robotics is that people build +robots and you look at any laboratory + + align:start position:0% +robots and you look at any laboratory + + + align:start position:0% +robots and you look at any laboratory +that has built a physical + + align:start position:0% +that has built a physical + + + align:start position:0% +that has built a physical +robot and media lab is a perfect example + + align:start position:0% +robot and media lab is a perfect example + + + align:start position:0% +robot and media lab is a perfect example +of + + align:start position:0% +of + + + align:start position:0% +of +it or Rod Brooks + + align:start position:0% +it or Rod Brooks + + + align:start position:0% +it or Rod Brooks +uh had a wonderful robot called Cog with + + align:start position:0% +uh had a wonderful robot called Cog with + + + align:start position:0% +uh had a wonderful robot called Cog with +a head and two + + align:start position:0% +a head and two + + + align:start position:0% +a head and two +hands took a lot of engineering and + + align:start position:0% +hands took a lot of engineering and + + + align:start position:0% +hands took a lot of engineering and +there was only one of it and it only + + align:start position:0% +there was only one of it and it only + + + align:start position:0% +there was only one of it and it only +worked for a few hours a week because + + align:start position:0% +worked for a few hours a week because + + + align:start position:0% +worked for a few hours a week because +it's very complicated and it breaks and + + align:start position:0% +it's very complicated and it breaks and + + + align:start position:0% +it's very complicated and it breaks and +so + + align:start position:0% +so + + + align:start position:0% +so +uh so the + + align:start position:0% +uh so the + + + align:start position:0% +uh so the +joke is that if I were starting a + + align:start position:0% +joke is that if I were starting a + + + align:start position:0% +joke is that if I were starting a +robotic slab I would not permit + + align:start position:0% + + + + align:start position:0% + +robots once you simulate the robots and + + align:start position:0% +robots once you simulate the robots and + + + align:start position:0% +robots once you simulate the robots and +get them to do + + align:start position:0% +get them to do + + + align:start position:0% +get them to do +do what you want uh then you take it out + + align:start position:0% +do what you want uh then you take it out + + + align:start position:0% +do what you want uh then you take it out +of the + + align:start position:0% +of the + + + align:start position:0% +of the +university and hire some good mechanical + + align:start position:0% +university and hire some good mechanical + + + align:start position:0% +university and hire some good mechanical +engineers to make the robot you want but + + align:start position:0% +engineers to make the robot you want but + + + align:start position:0% +engineers to make the robot you want but +you don't want to robotics research + + align:start position:0% +you don't want to robotics research + + + align:start position:0% +you don't want to robotics research +should not involve robots and I + + align:start position:0% +should not involve robots and I + + + align:start position:0% +should not involve robots and I +think I have sort of mixed feelings + + align:start position:0% +think I have sort of mixed feelings + + + align:start position:0% +think I have sort of mixed feelings +about the + + align:start position:0% + + + + align:start position:0% + +uh what's the great basketball robot + + align:start position:0% +uh what's the great basketball robot + + + align:start position:0% +uh what's the great basketball robot +event called + + align:start position:0% + + + + align:start position:0% + +Bas mean soccer well whatever you call + + align:start position:0% +Bas mean soccer well whatever you call + + + align:start position:0% +Bas mean soccer well whatever you call +it they kick a ball and try to get it's + + align:start position:0% +it they kick a ball and try to get it's + + + align:start position:0% +it they kick a ball and try to get it's +actually + + align:start position:0% +actually + + + align:start position:0% +actually +it's they try to get it through to a + + align:start position:0% +it's they try to get it through to a + + + align:start position:0% +it's they try to get it through to a +goal so it is it is soccer + + align:start position:0% +goal so it is it is soccer + + + align:start position:0% +goal so it is it is soccer +RoboCop yeah + + align:start position:0% +RoboCop yeah + + + align:start position:0% +RoboCop yeah +whatever uh that's probably a plus for + + align:start position:0% +whatever uh that's probably a plus for + + + align:start position:0% +whatever uh that's probably a plus for +the high school students who are + + align:start position:0% +the high school students who are + + + align:start position:0% +the high school students who are +involved in it but yes why don't you + + align:start position:0% +involved in it but yes why don't you + + + align:start position:0% +involved in it but yes why don't you +would have like uh uh robots that all + + align:start position:0% +would have like uh uh robots that all + + + align:start position:0% +would have like uh uh robots that all +like University use as like a base why + + align:start position:0% +like University use as like a base why + + + align:start position:0% +like University use as like a base why +why do we do we keep building Hardware + + align:start position:0% +why do we do we keep building Hardware + + + align:start position:0% +why do we do we keep building Hardware +like is is it necessary to keep building + + align:start position:0% +like is is it necessary to keep building + + + align:start position:0% +like is is it necessary to keep building +Hardware all back again I'm not sure + + align:start position:0% +Hardware all back again I'm not sure + + + align:start position:0% +Hardware all back again I'm not sure +what what's your question like when we + + align:start position:0% +what what's your question like when we + + + align:start position:0% +what what's your question like when we +use computers we don't build the + + align:start position:0% +use computers we don't build the + + + align:start position:0% +use computers we don't build the +computers like again we + + align:start position:0% +computers like again we + + + align:start position:0% +computers like again we +use the like we just create software yes + + align:start position:0% +use the like we just create software yes + + + align:start position:0% +use the like we just create software yes +aren't we doing the same for for r and + + align:start position:0% +aren't we doing the same for for r and + + + align:start position:0% +aren't we doing the same for for r and +if not why are we just programming the + + align:start position:0% +if not why are we just programming the + + + align:start position:0% +if not why are we just programming the +robot to do stuff that we want what I'm + + align:start position:0% +robot to do stuff that we want what I'm + + + align:start position:0% +robot to do stuff that we want what I'm +say what I'm saying is that if people + + align:start position:0% +say what I'm saying is that if people + + + align:start position:0% +say what I'm saying is that if people +program the + + align:start position:0% +program the + + + align:start position:0% +program the +robot then it takes them two weeks to do + + align:start position:0% +robot then it takes them two weeks to do + + + align:start position:0% +robot then it takes them two weeks to do +the simplest + + align:start position:0% +the simplest + + + align:start position:0% +the simplest +thing if you're programming a simulated + + align:start position:0% +thing if you're programming a simulated + + + align:start position:0% +thing if you're programming a simulated +robot then it takes two minutes why does + + align:start position:0% +robot then it takes two minutes why does + + + align:start position:0% +robot then it takes two minutes why does +it take + + align:start position:0% +it take + + + align:start position:0% +it take +more because the robot's broken and + + align:start position:0% +more because the robot's broken and + + + align:start position:0% +more because the robot's broken and +there's only one in the lab and there + + align:start position:0% +there's only one in the lab and there + + + align:start position:0% +there's only one in the lab and there +are eight people who want to use it and + + align:start position:0% +are eight people who want to use it and + + + align:start position:0% +are eight people who want to use it and +3/4 of the time it's down because some + + align:start position:0% +3/4 of the time it's down because some + + + align:start position:0% +3/4 of the time it's down because some +motor because it's not in mass + + align:start position:0% +motor because it's not in mass + + + align:start position:0% +motor because it's not in mass +production if you have a machine that + + align:start position:0% +production if you have a machine that + + + align:start position:0% +production if you have a machine that +somebody + + align:start position:0% +somebody + + + align:start position:0% +somebody +made it's probably the first machine + + align:start position:0% +made it's probably the first machine + + + align:start position:0% +made it's probably the first machine +that person ever + + align:start position:0% +that person ever + + + align:start position:0% +that person ever +made so it's no + + align:start position:0% +made so it's no + + + align:start position:0% +made so it's no +good look at the Honda robot called + + align:start position:0% + + + + align:start position:0% + +Asimo have you you've all seen it but + + align:start position:0% +Asimo have you you've all seen it but + + + align:start position:0% +Asimo have you you've all seen it but +you all saw it 10 years ago + + align:start position:0% +you all saw it 10 years ago + + + align:start position:0% +you all saw it 10 years ago +go it has not changed but they they say + + align:start position:0% +go it has not changed but they they say + + + align:start position:0% +go it has not changed but they they say +it doesn't fall over so often + + align:start position:0% +it doesn't fall over so often + + + align:start position:0% +it doesn't fall over so often +anymore so like there is a company a + + align:start position:0% +anymore so like there is a company a + + + align:start position:0% +anymore so like there is a company a +French company that there a robot called + + align:start position:0% +French company that there a robot called + + + align:start position:0% +French company that there a robot called +now robot that like it works pretty good + + align:start position:0% +now robot that like it works pretty good + + + align:start position:0% +now robot that like it works pretty good +I don't know why why don't we use a we + + align:start position:0% +I don't know why why don't we use a we + + + align:start position:0% +I don't know why why don't we use a we +buy some robots from some company + + align:start position:0% +buy some robots from some company + + + align:start position:0% +buy some robots from some company +because they're no + + align:start position:0% +because they're no + + + align:start position:0% +because they're no +good they don't do any they've only got + + align:start position:0% +good they don't do any they've only got + + + align:start position:0% +good they don't do any they've only got +one elbow + + align:start position:0% + + + + align:start position:0% + +they can't reach around they don't have + + align:start position:0% +they can't reach around they don't have + + + align:start position:0% +they can't reach around they don't have +they don't not you can buy a hand for 30 + + align:start position:0% +they don't not you can buy a hand for 30 + + + align:start position:0% +they don't not you can buy a hand for 30 +or $40,000 that has three or four + + align:start position:0% +or $40,000 that has three or four + + + align:start position:0% +or $40,000 that has three or four +fingers + + align:start position:0% +fingers + + + align:start position:0% +fingers +but tradeoff though + + align:start position:0% +but tradeoff though + + + align:start position:0% +but tradeoff though +between you know making a more complex + + align:start position:0% +between you know making a more complex + + + align:start position:0% +between you know making a more complex +robot that has more interaction you can + + align:start position:0% +robot that has more interaction you can + + + align:start position:0% +robot that has more interaction you can +make you know that gets more you're + + align:start position:0% +make you know that gets more you're + + + align:start position:0% +make you know that gets more you're +building an actual robot but for a + + align:start position:0% +building an actual robot but for a + + + align:start position:0% +building an actual robot but for a +simulator simulating the Real + + align:start position:0% +simulator simulating the Real + + + align:start position:0% +simulator simulating the Real +Environment gravity and those sort of + + align:start position:0% +Environment gravity and those sort of + + + align:start position:0% +Environment gravity and those sort of +systems + + align:start position:0% +systems + + + align:start position:0% +systems +can also be difficult to create so that + + align:start position:0% +can also be difficult to create so that + + + align:start position:0% +can also be difficult to create so that +you're sure that whatever the reaction + + align:start position:0% +you're sure that whatever the reaction + + + align:start position:0% +you're sure that whatever the reaction +so your program robot you need to make + + align:start position:0% +so your program robot you need to make + + + align:start position:0% +so your program robot you need to make +sure the environment in is somewh real + + align:start position:0% +sure the environment in is somewh real + + + align:start position:0% +sure the environment in is somewh real +well it depends what you mean by real uh + + align:start position:0% +well it depends what you mean by real uh + + + align:start position:0% +well it depends what you mean by real uh +it seems to me if if the robot is smart + + align:start position:0% +it seems to me if if the robot is smart + + + align:start position:0% +it seems to me if if the robot is smart +and can learn and is adaptable and uh + + align:start position:0% +and can learn and is adaptable and uh + + + align:start position:0% +and can learn and is adaptable and uh +when a piece of piece of its software + + align:start position:0% +when a piece of piece of its software + + + align:start position:0% +when a piece of piece of its software +doesn't work then it modifies it + + align:start position:0% +doesn't work then it modifies it + + + align:start position:0% +doesn't work then it modifies it +uh in other words if you had a higher + + align:start position:0% +uh in other words if you had a higher + + + align:start position:0% +uh in other words if you had a higher +level learning machine in the in the uh + + align:start position:0% +level learning machine in the in the uh + + + align:start position:0% +level learning machine in the in the uh +processor of the + + align:start position:0% +processor of the + + + align:start position:0% +processor of the +robot then it could work in a real + + align:start position:0% +robot then it could work in a real + + + align:start position:0% +robot then it could work in a real +environment by learning that if you do + + align:start position:0% +environment by learning that if you do + + + align:start position:0% +environment by learning that if you do +this on a slippery floor you might uh + + align:start position:0% +this on a slippery floor you might uh + + + align:start position:0% +this on a slippery floor you might uh +maybe you should lean the other way + + align:start position:0% +maybe you should lean the other way + + + align:start position:0% +maybe you should lean the other way +before + + align:start position:0% +before + + + align:start position:0% +before +you uh Patty Mays did a little bit of + + align:start position:0% +you uh Patty Mays did a little bit of + + + align:start position:0% +you uh Patty Mays did a little bit of +that 20 years + + align:start position:0% +that 20 years + + + align:start position:0% +that 20 years +ago uh with + + align:start position:0% +ago uh with + + + align:start position:0% +ago uh with +what rule system that + + align:start position:0% + + + + align:start position:0% + +moving yeah but you see if you have a + + align:start position:0% +moving yeah but you see if you have a + + + align:start position:0% +moving yeah but you see if you have a +real robot you've only got an hour a + + align:start position:0% +real robot you've only got an hour a + + + align:start position:0% +real robot you've only got an hour a +week uh to debug this thing and and the + + align:start position:0% +week uh to debug this thing and and the + + + align:start position:0% +week uh to debug this thing and and the +program is working in real time if you + + align:start position:0% +program is working in real time if you + + + align:start position:0% +program is working in real time if you +look at real + + align:start position:0% +look at real + + + align:start position:0% +look at real +robots whereas if you're simulating a + + align:start position:0% +robots whereas if you're simulating a + + + align:start position:0% +robots whereas if you're simulating a +stick figure robot then you can simulate + + align:start position:0% +stick figure robot then you can simulate + + + align:start position:0% +stick figure robot then you can simulate +friction and slipping but uh you can + + align:start position:0% +friction and slipping but uh you can + + + align:start position:0% +friction and slipping but uh you can +move it as at + + align:start position:0% +move it as at + + + align:start position:0% +move it as at +uh 100,000 operations per second maybe + + align:start position:0% +uh 100,000 operations per second maybe + + + align:start position:0% +uh 100,000 operations per second maybe +another thing is uh there's something + + align:start position:0% +another thing is uh there's something + + + align:start position:0% +another thing is uh there's something +weird about the robot people they tell + + align:start position:0% +weird about the robot people they tell + + + align:start position:0% +weird about the robot people they tell +me there's so much uh feedback needed + + align:start position:0% +me there's so much uh feedback needed + + + align:start position:0% +me there's so much uh feedback needed +that they need a separate computer for + + align:start position:0% +that they need a separate computer for + + + align:start position:0% +that they need a separate computer for +each + + align:start position:0% + + + + align:start position:0% + +joint I hear this everywhere they say + + align:start position:0% +joint I hear this everywhere they say + + + align:start position:0% +joint I hear this everywhere they say +it's + + align:start position:0% +it's + + + align:start position:0% +it's +distributed it's really good of course + + align:start position:0% +distributed it's really good of course + + + align:start position:0% +distributed it's really good of course +it's still falling + + align:start position:0% +it's still falling + + + align:start position:0% +it's still falling +over agre there lot about robots that um + + align:start position:0% +over agre there lot about robots that um + + + align:start position:0% +over agre there lot about robots that um +can be simulated on a computer and I + + align:start position:0% +can be simulated on a computer and I + + + align:start position:0% +can be simulated on a computer and I +agree that a lot of the good things that + + align:start position:0% +agree that a lot of the good things that + + + align:start position:0% +agree that a lot of the good things that +people are currently working on with + + align:start position:0% +people are currently working on with + + + align:start position:0% +people are currently working on with +real robots would better be um first + + align:start position:0% +real robots would better be um first + + + align:start position:0% +real robots would better be um first +done simulated but I think that when you + + align:start position:0% +done simulated but I think that when you + + + align:start position:0% +done simulated but I think that when you +have a robot especially when you have + + align:start position:0% +have a robot especially when you have + + + align:start position:0% +have a robot especially when you have +situations where it interacts with the + + align:start position:0% +situations where it interacts with the + + + align:start position:0% +situations where it interacts with the +human being the reaction of the human + + align:start position:0% +human being the reaction of the human + + + align:start position:0% +human being the reaction of the human +being is sort of is really different um + + align:start position:0% +being is sort of is really different um + + + align:start position:0% +being is sort of is really different um +depending on whether it's a simulation + + align:start position:0% +depending on whether it's a simulation + + + align:start position:0% +depending on whether it's a simulation +or a physical being because I think I + + align:start position:0% +or a physical being because I think I + + + align:start position:0% +or a physical being because I think I +guess human beings inherently have + + align:start position:0% +guess human beings inherently have + + + align:start position:0% +guess human beings inherently have +different reactions to objects with + + align:start position:0% +different reactions to objects with + + + align:start position:0% +different reactions to objects with +physical monuments so so I feel like at + + align:start position:0% +physical monuments so so I feel like at + + + align:start position:0% +physical monuments so so I feel like at +a certain point especially when it + + align:start position:0% +a certain point especially when it + + + align:start position:0% +a certain point especially when it +interfaces with humans such as caretaker + + align:start position:0% +interfaces with humans such as caretaker + + + align:start position:0% +interfaces with humans such as caretaker +robots you do have to switch to the real + + align:start position:0% +robots you do have to switch to the real + + + align:start position:0% +robots you do have to switch to the real +robots well the caretaker robot has to + + align:start position:0% +robots well the caretaker robot has to + + + align:start position:0% +robots well the caretaker robot has to +uh be a smart program that's running a + + align:start position:0% +uh be a smart program that's running a + + + align:start position:0% +uh be a smart program that's running a +physical robot eventually it's just that + + align:start position:0% +physical robot eventually it's just that + + + align:start position:0% +physical robot eventually it's just that +we don't have the smart programs and we + + align:start position:0% +we don't have the smart programs and we + + + align:start position:0% +we don't have the smart programs and we +could have had them 25 years ago if the + + align:start position:0% +could have had them 25 years ago if the + + + align:start position:0% +could have had them 25 years ago if the +people wanting to make a helper robot + + align:start position:0% +people wanting to make a helper robot + + + align:start position:0% +people wanting to make a helper robot +didn't have a physical robot in their + + align:start position:0% +didn't have a physical robot in their + + + align:start position:0% +didn't have a physical robot in their +lab uh look at Cog which Cog is proudly + + align:start position:0% +lab uh look at Cog which Cog is proudly + + + align:start position:0% +lab uh look at Cog which Cog is proudly +displayed in the MIT + + align:start position:0% +displayed in the MIT + + + align:start position:0% +displayed in the MIT +Museum I don't know of a + + align:start position:0% + + + + align:start position:0% + +single fact or technique or idea that + + align:start position:0% +single fact or technique or idea that + + + align:start position:0% +single fact or technique or idea that +came out of that project in the decade + + align:start position:0% +came out of that project in the decade + + + align:start position:0% +came out of that project in the decade +when graduate students wrote bad thesis + + align:start position:0% +when graduate students wrote bad thesis + + + align:start position:0% +when graduate students wrote bad thesis +about + + align:start position:0% +about + + + align:start position:0% +about +it so I guess then ultimately it's sort + + align:start position:0% +it so I guess then ultimately it's sort + + + align:start position:0% +it so I guess then ultimately it's sort +of like a division of um labor problem + + align:start position:0% +of like a division of um labor problem + + + align:start position:0% +of like a division of um labor problem +where it's like because it seems like + + align:start position:0% +where it's like because it seems like + + + align:start position:0% +where it's like because it seems like +when people are their code on actual + + align:start position:0% +when people are their code on actual + + + align:start position:0% +when people are their code on actual +robots it's like they have too many + + align:start position:0% +robots it's like they have too many + + + align:start position:0% +robots it's like they have too many +problems at the same time whereas you're + + align:start position:0% +problems at the same time whereas you're + + + align:start position:0% +problems at the same time whereas you're +saying they should focus on the software + + align:start position:0% +saying they should focus on the software + + + align:start position:0% +saying they should focus on the software +and after the software is like all good + + align:start position:0% +and after the software is like all good + + + align:start position:0% +and after the software is like all good +then they can move on to like + + align:start position:0% +then they can move on to like + + + align:start position:0% +then they can move on to like +integrating the software with the + + align:start position:0% +integrating the software with the + + + align:start position:0% +integrating the software with the +hardware yeah well the robots in uh + + align:start position:0% +hardware yeah well the robots in uh + + + align:start position:0% +hardware yeah well the robots in uh +Second Life but we're pretty good uh I + + align:start position:0% +Second Life but we're pretty good uh I + + + align:start position:0% +Second Life but we're pretty good uh I +don't know of any people who complained + + align:start position:0% +don't know of any people who complained + + + align:start position:0% +don't know of any people who complained +that they wanted real + + align:start position:0% + + + + align:start position:0% + +ones not familiar with the + + align:start position:0% +ones not familiar with the + + + align:start position:0% +ones not familiar with the +what did they do well you could make one + + align:start position:0% +what did they do well you could make one + + + align:start position:0% +what did they do well you could make one +because there was a a language for I + + align:start position:0% +because there was a a language for I + + + align:start position:0% +because there was a a language for I +don't think they did anything much but + + align:start position:0% +don't think they did anything much but + + + align:start position:0% +don't think they did anything much but +but they don't fall + + align:start position:0% + + + + align:start position:0% + +over but I guess a good example might + + align:start position:0% +over but I guess a good example might + + + align:start position:0% +over but I guess a good example might +be + + align:start position:0% + + + + align:start position:0% + +uh well the dean + + align:start position:0% +uh well the dean + + + align:start position:0% +uh well the dean +cayman's um + + align:start position:0% + + + + align:start position:0% + +robot soccer project + + align:start position:0% +robot soccer project + + + align:start position:0% +robot soccer project +and Carnegie melon has a had a robot so + + align:start position:0% +and Carnegie melon has a had a robot so + + + align:start position:0% +and Carnegie melon has a had a robot so +socker project for many years and I + + align:start position:0% +socker project for many years and I + + + align:start position:0% +socker project for many years and I +don't know that + + align:start position:0% +don't know that + + + align:start position:0% +don't know that +any I've never heard of any interesting + + align:start position:0% +any I've never heard of any interesting + + + align:start position:0% +any I've never heard of any interesting +discovery that came from + + align:start position:0% + + + + align:start position:0% + +that uh the media lab + + align:start position:0% +that uh the media lab + + + align:start position:0% +that uh the media lab +also they're the Nic looking robots that + + align:start position:0% +also they're the Nic looking robots that + + + align:start position:0% +also they're the Nic looking robots that +smile + + align:start position:0% + + + + align:start position:0% + +and people are impressed + + align:start position:0% +and people are impressed + + + align:start position:0% +and people are impressed +by uh the way that humans are attracted + + align:start position:0% +by uh the way that humans are attracted + + + align:start position:0% +by uh the way that humans are attracted +to + + align:start position:0% +to + + + align:start position:0% +to +these uh to interact with these + + align:start position:0% +these uh to interact with these + + + align:start position:0% +these uh to interact with these +robots + + align:start position:0% +robots + + + align:start position:0% +robots +but I think once we know that it's + + align:start position:0% +but I think once we know that it's + + + align:start position:0% +but I think once we know that it's +something to avoid rather than to + + align:start position:0% +something to avoid rather than to + + + align:start position:0% +something to avoid rather than to +exploit until when the robot says please + + align:start position:0% +exploit until when the robot says please + + + align:start position:0% +exploit until when the robot says please +to meet you uh wouldn't it be nice if it + + align:start position:0% +to meet you uh wouldn't it be nice if it + + + align:start position:0% +to meet you uh wouldn't it be nice if it +were at actually pleased to meet + + align:start position:0% + + + + align:start position:0% + +you the intelligent welcome mat should + + align:start position:0% +you the intelligent welcome mat should + + + align:start position:0% +you the intelligent welcome mat should +be our + + align:start position:0% + + + + align:start position:0% + +Target even if it doesn't move if it + + align:start position:0% +Target even if it doesn't move if it + + + align:start position:0% +Target even if it doesn't move if it +just sat there and felt good about + + align:start position:0% +just sat there and felt good about + + + align:start position:0% +just sat there and felt good about +seeing you that would be a great + + align:start position:0% +seeing you that would be a great + + + align:start position:0% +seeing you that would be a great +achievement I don't know how you would + + align:start position:0% +achievement I don't know how you would + + + align:start position:0% +achievement I don't know how you would +test for + + align:start position:0% + + + + align:start position:0% + +it have you ever played with the Cleo + + align:start position:0% +it have you ever played with the Cleo + + + align:start position:0% +it have you ever played with the Cleo +dinosaur + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +yes and there was a cat that + + align:start position:0% +yes and there was a cat that + + + align:start position:0% +yes and there was a cat that +uh Itachi + + align:start position:0% + + + + align:start position:0% + +made in fact we ordered a pleo but we + + align:start position:0% +made in fact we ordered a pleo but we + + + align:start position:0% +made in fact we ordered a pleo but we +never got it do they are they still in + + align:start position:0% +never got it do they are they still in + + + align:start position:0% +never got it do they are they still in +production uh I believe so I don't I + + align:start position:0% +production uh I believe so I don't I + + + align:start position:0% +production uh I believe so I don't I +don't know I believe + + align:start position:0% +don't know I believe + + + align:start position:0% +don't know I believe +so they like they appear to be what they + + align:start position:0% +so they like they appear to be what they + + + align:start position:0% +so they like they appear to be what they +appear to be yeah it beautiful + + align:start position:0% + + + + align:start position:0% + +job somebody made a cat I'm trying to + + align:start position:0% +job somebody made a cat I'm trying to + + + align:start position:0% +job somebody made a cat I'm trying to +remember another Japanese + + align:start position:0% +remember another Japanese + + + align:start position:0% +remember another Japanese +company it was an awfully good + + align:start position:0% +company it was an awfully good + + + align:start position:0% +company it was an awfully good +cat it wouldn't do much but every now + + align:start position:0% +cat it wouldn't do much but every now + + + align:start position:0% +cat it wouldn't do much but every now +and then it would Mew and sort of look + + align:start position:0% +and then it would Mew and sort of look + + + align:start position:0% +and then it would Mew and sort of look +at look at you and beg for something but + + align:start position:0% +at look at you and beg for something but + + + align:start position:0% +at look at you and beg for something but +you you couldn't resist + + align:start position:0% + + + + align:start position:0% + +it yeah + + align:start position:0% +it yeah + + + align:start position:0% +it yeah +do you know how long would you take to + + align:start position:0% +do you know how long would you take to + + + align:start position:0% +do you know how long would you take to +kind of simulate a real world to like + + align:start position:0% +kind of simulate a real world to like + + + align:start position:0% +kind of simulate a real world to like +kind of great uh to create simulation + + align:start position:0% +kind of great uh to create simulation + + + align:start position:0% +kind of great uh to create simulation +simple simulation the well what and how + + align:start position:0% +simple simulation the well what and how + + + align:start position:0% +simple simulation the well what and how +many people because I you're saying that + + align:start position:0% +many people because I you're saying that + + + align:start position:0% +many people because I you're saying that +we should simulate robots in the + + align:start position:0% +we should simulate robots in the + + + align:start position:0% +we should simulate robots in the +computer create software for that + + align:start position:0% +computer create software for that + + + align:start position:0% +computer create software for that +instead of creating real robots and so + + align:start position:0% +instead of creating real robots and so + + + align:start position:0% +instead of creating real robots and so +we need to create a software that + + align:start position:0% +we need to create a software that + + + align:start position:0% +we need to create a software that +simulates the real world + + align:start position:0% +simulates the real world + + + align:start position:0% +simulates the real world +mhm that's complicated for me you know + + align:start position:0% +mhm that's complicated for me you know + + + align:start position:0% +mhm that's complicated for me you know +like have some ideas like how long would + + align:start position:0% +like have some ideas like how long would + + + align:start position:0% +like have some ideas like how long would +you take would it take how many people + + align:start position:0% +you take would it take how many people + + + align:start position:0% +you take would it take how many people +and why are why aren't we doing that or + + align:start position:0% +and why are why aren't we doing that or + + + align:start position:0% +and why are why aren't we doing that or +why isn't there somebody do + + align:start position:0% + + + + align:start position:0% + +that I wish somebody would explain to me + + align:start position:0% +that I wish somebody would explain to me + + + align:start position:0% +that I wish somebody would explain to me +why why the majority of you know there + + align:start position:0% +why why the majority of you know there + + + align:start position:0% +why why the majority of you know there +there are + + align:start position:0% + + + + align:start position:0% + +uh there are epidemics of + + align:start position:0% +uh there are epidemics of + + + align:start position:0% +uh there are epidemics of +ideologies so that uh around + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +the dominant idea of making machines + + align:start position:0% +the dominant idea of making machines + + + align:start position:0% +the dominant idea of making machines +better was to build rule-based + + align:start position:0% +better was to build rule-based + + + align:start position:0% +better was to build rule-based +systems and uh that's probably still + + align:start position:0% +systems and uh that's probably still + + + align:start position:0% +systems and uh that's probably still +the uh most + + align:start position:0% +the uh most + + + align:start position:0% +the uh most +popular way to program a computer for a + + align:start position:0% +popular way to program a computer for a + + + align:start position:0% +popular way to program a computer for a +complicated commercial application like + + align:start position:0% +complicated commercial application like + + + align:start position:0% +complicated commercial application like +making airplane reservations and keeping + + align:start position:0% +making airplane reservations and keeping + + + align:start position:0% +making airplane reservations and keeping +keeping stock of + + align:start position:0% +keeping stock of + + + align:start position:0% +keeping stock of +uh Parts in the factory and on and on + + align:start position:0% +uh Parts in the factory and on and on + + + align:start position:0% +uh Parts in the factory and on and on +uh now when the first rule-based systems + + align:start position:0% +uh now when the first rule-based systems + + + align:start position:0% +uh now when the first rule-based systems +appeared they were called production + + align:start position:0% +appeared they were called production + + + align:start position:0% +appeared they were called production +based languages production is just + + align:start position:0% +based languages production is just + + + align:start position:0% +based languages production is just +uh I think the word comes from Amo post + + align:start position:0% +uh I think the word comes from Amo post + + + align:start position:0% +uh I think the word comes from Amo post +in the + + align:start position:0% +in the + + + align:start position:0% +in the +1920s and the idea is you you have a set + + align:start position:0% +1920s and the idea is you you have a set + + + align:start position:0% +1920s and the idea is you you have a set +of symbols x + + align:start position:0% +of symbols x + + + align:start position:0% +of symbols x +a y p + + align:start position:0% + + + + align:start position:0% + +z where XY + + align:start position:0% +z where XY + + + align:start position:0% +z where XY +and I meant + + align:start position:0% +and I meant + + + align:start position:0% +and I meant +Z XY and z are variables and a and b are + + align:start position:0% +Z XY and z are variables and a and b are + + + align:start position:0% +Z XY and z are variables and a and b are +constants in other words an algebraic + + align:start position:0% +constants in other words an algebraic + + + align:start position:0% +constants in other words an algebraic +expression + + align:start position:0% +expression + + + align:start position:0% +expression +basically and if the state of the world + + align:start position:0% +basically and if the state of the world + + + align:start position:0% +basically and if the state of the world +or the state of some process is + + align:start position:0% +or the state of some process is + + + align:start position:0% +or the state of some process is +described by this expression then uh + + align:start position:0% +described by this expression then uh + + + align:start position:0% +described by this expression then uh +then you change it into + + align:start position:0% +then you change it into + + + align:start position:0% +then you change it into +uh um something else like + + align:start position:0% +uh um something else like + + + align:start position:0% +uh um something else like +ax so one operation might be if if + + align:start position:0% +ax so one operation might be if if + + + align:start position:0% +ax so one operation might be if if +there's an ace anywhere let's move it uh + + align:start position:0% +there's an ace anywhere let's move it uh + + + align:start position:0% +there's an ace anywhere let's move it uh +to the left that's that's just a simple + + align:start position:0% +to the left that's that's just a simple + + + align:start position:0% +to the left that's that's just a simple +production C uh anyway if you read my + + align:start position:0% +production C uh anyway if you read my + + + align:start position:0% +production C uh anyway if you read my +old book on + + align:start position:0% +old book on + + + align:start position:0% +old book on +computation there's a couple of chapters + + align:start position:0% +computation there's a couple of chapters + + + align:start position:0% +computation there's a couple of chapters +about production systems + + align:start position:0% +about production systems + + + align:start position:0% +about production systems +and uh those were + + align:start position:0% +and uh those were + + + align:start position:0% +and uh those were +the the first Universal logical systems + + align:start position:0% +the the first Universal logical systems + + + align:start position:0% +the the first Universal logical systems +that could be applied to computers so + + align:start position:0% +that could be applied to computers so + + + align:start position:0% +that could be applied to computers so +although there were no computers in the + + align:start position:0% +although there were no computers in the + + + align:start position:0% +although there were no computers in the +1920s when Amil post started working on + + align:start position:0% +1920s when Amil post started working on + + + align:start position:0% +1920s when Amil post started working on +that there had been some + + align:start position:0% +that there had been some + + + align:start position:0% +that there had been some +discussion uh back in 1900 or so when + + align:start position:0% +discussion uh back in 1900 or so when + + + align:start position:0% +discussion uh back in 1900 or so when +mathematicians like Hilbert uh who were + + align:start position:0% +mathematicians like Hilbert uh who were + + + align:start position:0% +mathematicians like Hilbert uh who were +interested both in Applied Mathematics + + align:start position:0% +interested both in Applied Mathematics + + + align:start position:0% +interested both in Applied Mathematics +and basic uh + + align:start position:0% +and basic uh + + + align:start position:0% +and basic uh +logic logic + + align:start position:0% +logic logic + + + align:start position:0% +logic logic +theories uh we're trying to say what + + align:start position:0% +theories uh we're trying to say what + + + align:start position:0% +theories uh we're trying to say what +kinds of processes can be represented by + + align:start position:0% +kinds of processes can be represented by + + + align:start position:0% +kinds of processes can be represented by +what kinds of algebraic or uh production + + align:start position:0% +what kinds of algebraic or uh production + + + align:start position:0% +what kinds of algebraic or uh production +like systems so so there was a lot of + + align:start position:0% +like systems so so there was a lot of + + + align:start position:0% +like systems so so there was a lot of +research before well not a lot but quite + + align:start position:0% +research before well not a lot but quite + + + align:start position:0% +research before well not a lot but quite +a bit of research before computers even + + align:start position:0% +a bit of research before computers even + + + align:start position:0% +a bit of research before computers even +appeared and in the + + align:start position:0% +appeared and in the + + + align:start position:0% +appeared and in the +1950s uh making rule-based + + align:start position:0% +1950s uh making rule-based + + + align:start position:0% +1950s uh making rule-based +systems + + align:start position:0% +systems + + + align:start position:0% +systems +uh just out of uh transforming sequences + + align:start position:0% +uh just out of uh transforming sequences + + + align:start position:0% +uh just out of uh transforming sequences +of symbols became popular and uh that + + align:start position:0% +of symbols became popular and uh that + + + align:start position:0% +of symbols became popular and uh that +was fine because those systems are sort + + align:start position:0% +was fine because those systems are sort + + + align:start position:0% +was fine because those systems are sort +of + + align:start position:0% +of + + + align:start position:0% +of +universal however to make a + + align:start position:0% +universal however to make a + + + align:start position:0% +universal however to make a +uh a production system to play a good + + align:start position:0% +uh a production system to play a good + + + align:start position:0% +uh a production system to play a good +game of chess there might be some point + + align:start position:0% +game of chess there might be some point + + + align:start position:0% +game of chess there might be some point +at which just making rules saying if + + align:start position:0% +at which just making rules saying if + + + align:start position:0% +at which just making rules saying if +there's a pawn here and a queen here and + + align:start position:0% +there's a pawn here and a queen here and + + + align:start position:0% +there's a pawn here and a queen here and +a bishop here do this uh maybe you can't + + align:start position:0% +a bishop here do this uh maybe you can't + + + align:start position:0% +a bishop here do this uh maybe you can't +express things that way and you might + + align:start position:0% +express things that way and you might + + + align:start position:0% +express things that way and you might +have to have a higher level expression + + align:start position:0% +have to have a higher level expression + + + align:start position:0% +have to have a higher level expression +such as if two pieces are under attack + + align:start position:0% +such as if two pieces are under attack + + + align:start position:0% +such as if two pieces are under attack +at distant parts of the board then uh + + align:start position:0% +at distant parts of the board then uh + + + align:start position:0% +at distant parts of the board then uh +you should decide to make a move that + + align:start position:0% +you should decide to make a move that + + + align:start position:0% +you should decide to make a move that +improves your situation + + align:start position:0% +improves your situation + + + align:start position:0% +improves your situation +in in one what do you call these in one + + align:start position:0% +in in one what do you call these in one + + + align:start position:0% +in in one what do you call these in one +of these uh + + align:start position:0% +of these uh + + + align:start position:0% +of these uh +situations and blocks a way of the + + align:start position:0% +situations and blocks a way of the + + + align:start position:0% +situations and blocks a way of the +opponent improving his situation on the + + align:start position:0% +opponent improving his situation on the + + + align:start position:0% +opponent improving his situation on the +other one so you can't express that as a + + align:start position:0% +other one so you can't express that as a + + + align:start position:0% +other one so you can't express that as a +uh in terms of this position of the + + align:start position:0% +uh in terms of this position of the + + + align:start position:0% +uh in terms of this position of the +pieces you have to have a higher level + + align:start position:0% +pieces you have to have a higher level + + + align:start position:0% +pieces you have to have a higher level +abstraction and what happened in the + + align:start position:0% +abstraction and what happened in the + + + align:start position:0% +abstraction and what happened in the +development of rule-based systems is + + align:start position:0% +development of rule-based systems is + + + align:start position:0% +development of rule-based systems is +that you could make rules about rules + + align:start position:0% +that you could make rules about rules + + + align:start position:0% +that you could make rules about rules +but nobody ever got very good at it and + + align:start position:0% +but nobody ever got very good at it and + + + align:start position:0% +but nobody ever got very good at it and +you didn't + + align:start position:0% +you didn't + + + align:start position:0% +you didn't +find and you still don't find six level + + align:start position:0% +find and you still don't find six level + + + align:start position:0% +find and you still don't find six level +systems like the kind proposed in the in + + align:start position:0% +systems like the kind proposed in the in + + + align:start position:0% +systems like the kind proposed in the in +the Society of Mind book which says + + align:start position:0% +the Society of Mind book which says + + + align:start position:0% +the Society of Mind book which says +whatever you do you ought to have + + align:start position:0% +whatever you do you ought to have + + + align:start position:0% +whatever you do you ought to have +multiple + + align:start position:0% +multiple + + + align:start position:0% +multiple +levels uh and at the third or fourth + + align:start position:0% +levels uh and at the third or fourth + + + align:start position:0% +levels uh and at the third or fourth +level the system should have some + + align:start position:0% +level the system should have some + + + align:start position:0% +level the system should have some +reflective ability so that it's keeping + + align:start position:0% +reflective ability so that it's keeping + + + align:start position:0% +reflective ability so that it's keeping +track of how successful it's been at + + align:start position:0% +track of how successful it's been at + + + align:start position:0% +track of how successful it's been at +something that's a simple kind of + + align:start position:0% +something that's a simple kind of + + + align:start position:0% +something that's a simple kind of +learning or it's noticing that + + align:start position:0% +learning or it's noticing that + + + align:start position:0% +learning or it's noticing that +abstractions of a certain sort have been + + align:start position:0% +abstractions of a certain sort have been + + + align:start position:0% +abstractions of a certain sort have been +very productive in a certain kind of + + align:start position:0% +very productive in a certain kind of + + + align:start position:0% +very productive in a certain kind of +situation described by some other + + align:start position:0% +situation described by some other + + + align:start position:0% +situation described by some other +abstraction nobody's ever uh + + align:start position:0% +abstraction nobody's ever uh + + + align:start position:0% +abstraction nobody's ever uh +build any programs that go up four or + + align:start position:0% +build any programs that go up four or + + + align:start position:0% +build any programs that go up four or +five levels of that + + align:start position:0% +five levels of that + + + align:start position:0% +five levels of that +sort and I suppose the reason is that + + align:start position:0% +sort and I suppose the reason is that + + + align:start position:0% +sort and I suppose the reason is that +nobody uh virtually no one has a job + + align:start position:0% +nobody uh virtually no one has a job + + + align:start position:0% +nobody uh virtually no one has a job +where they could uh definitely plan to + + align:start position:0% +where they could uh definitely plan to + + + align:start position:0% +where they could uh definitely plan to +spend four or five years I think David + + align:start position:0% +spend four or five years I think David + + + align:start position:0% +spend four or five years I think David +here said he's did you say three or four + + align:start position:0% +here said he's did you say three or four + + + align:start position:0% +here said he's did you say three or four +years to to map out this animal that's + + align:start position:0% +years to to map out this animal that's + + + align:start position:0% +years to to map out this animal that's +my hope all right and then you should + + align:start position:0% +my hope all right and then you should + + + align:start position:0% +my hope all right and then you should +have a meta hope that you'll have such a + + align:start position:0% +have a meta hope that you'll have such a + + + align:start position:0% +have a meta hope that you'll have such a +good student or two that uh you'll only + + align:start position:0% +good student or two that uh you'll only + + + align:start position:0% +good student or two that uh you'll only +have to spend a year of it in this uh + + align:start position:0% +have to spend a year of it in this uh + + + align:start position:0% +have to spend a year of it in this uh +this young Richard green bladder bill + + align:start position:0% +this young Richard green bladder bill + + + align:start position:0% +this young Richard green bladder bill +gosper or uh Peter Samson will come up + + align:start position:0% +gosper or uh Peter Samson will come up + + + align:start position:0% +gosper or uh Peter Samson will come up +and you'll notice that he's better than + + align:start position:0% +and you'll notice that he's better than + + + align:start position:0% +and you'll notice that he's better than +you at this and that's the best thing + + align:start position:0% +you at this and that's the best thing + + + align:start position:0% +you at this and that's the best thing +and then you can uh quit and go to a + + align:start position:0% +and then you can uh quit and go to a + + + align:start position:0% +and then you can uh quit and go to a +higher level true but + + align:start position:0% +higher level true but + + + align:start position:0% +higher level true but +uh there aren't any jobs like + + align:start position:0% +uh there aren't any jobs like + + + align:start position:0% +uh there aren't any jobs like +that uh we had a lab sublab that split + + align:start position:0% +that uh we had a lab sublab that split + + + align:start position:0% +that uh we had a lab sublab that split +off from the media + + align:start position:0% +off from the media + + + align:start position:0% +off from the media +lab that uh I won't mention its name but + + align:start position:0% +lab that uh I won't mention its name but + + + align:start position:0% +lab that uh I won't mention its name but +its director got into the habit of + + align:start position:0% +its director got into the habit of + + + align:start position:0% +its director got into the habit of +wanning a progress report each + + align:start position:0% + + + + align:start position:0% + +month + + align:start position:0% +month + + + align:start position:0% +month +well uh when we were funded by + + align:start position:0% + + + + align:start position:0% + +arpa there was something about a + + align:start position:0% +arpa there was something about a + + + align:start position:0% +arpa there was something about a +proposal each year and guess what our + + align:start position:0% +proposal each year and guess what our + + + align:start position:0% +proposal each year and guess what our +proposal + + align:start position:0% + + + + align:start position:0% + +was anybody want to guess we intelligent + + align:start position:0% +was anybody want to guess we intelligent + + + align:start position:0% +was anybody want to guess we intelligent +machines it was what we had done we + + align:start position:0% +machines it was what we had done we + + + align:start position:0% +machines it was what we had done we +proposed to do what we had done last + + align:start position:0% + + + + align:start position:0% + +year + + align:start position:0% +year + + + align:start position:0% +year +uh of course it's nice when when the + + align:start position:0% +uh of course it's nice when when the + + + align:start position:0% +uh of course it's nice when when the +head of the agency is an old buddy of + + align:start position:0% +head of the agency is an old buddy of + + + align:start position:0% +head of the agency is an old buddy of +yours from undergraduate years that was + + align:start position:0% +yours from undergraduate years that was + + + align:start position:0% +yours from undergraduate years that was +licklider but uh that worked out fine + + align:start position:0% +licklider but uh that worked out fine + + + align:start position:0% +licklider but uh that worked out fine +and so our proposals were in fact + + align:start position:0% +and so our proposals were in fact + + + align:start position:0% +and so our proposals were in fact +progress + + align:start position:0% +progress + + + align:start position:0% +progress +reports and + + align:start position:0% +reports and + + + align:start position:0% +reports and +uh that way uh you could do anything you + + align:start position:0% +uh that way uh you could do anything you + + + align:start position:0% +uh that way uh you could do anything you +want now if you had to do that every + + align:start position:0% +want now if you had to do that every + + + align:start position:0% +want now if you had to do that every +month then those uh proposals would + + align:start position:0% +month then those uh proposals would + + + align:start position:0% +month then those uh proposals would +would look so flimsy and sick that uh + + align:start position:0% +would look so flimsy and sick that uh + + + align:start position:0% +would look so flimsy and sick that uh +any good executive would say you should + + align:start position:0% +any good executive would say you should + + + align:start position:0% +any good executive would say you should +squash that project it's not getting + + align:start position:0% +squash that project it's not getting + + + align:start position:0% +squash that project it's not getting +anything done + + align:start position:0% + + + + align:start position:0% + +well I don't know how to fix that + + align:start position:0% + + + + align:start position:0% + +U if we try to deal with + + align:start position:0% +U if we try to deal with + + + align:start position:0% +U if we try to deal with +the economic collapse of the + + align:start position:0% +the economic collapse of the + + + align:start position:0% +the economic collapse of the +civilization we're + + align:start position:0% +civilization we're + + + align:start position:0% +civilization we're +in + + align:start position:0% +in + + + align:start position:0% +in +uh we + + align:start position:0% +uh we + + + align:start position:0% +uh we +may it may be politically hard to have + + align:start position:0% +may it may be politically hard to have + + + align:start position:0% +may it may be politically hard to have +five or 10 year research projects so I + + align:start position:0% +five or 10 year research projects so I + + + align:start position:0% +five or 10 year research projects so I +have no idea what's going to happen + + align:start position:0% +have no idea what's going to happen + + + align:start position:0% +have no idea what's going to happen +in in the next decade + + align:start position:0% +in in the next decade + + + align:start position:0% +in in the next decade +yes so two questions one what do you + + align:start position:0% +yes so two questions one what do you + + + align:start position:0% +yes so two questions one what do you +think is the most effective format for + + align:start position:0% +think is the most effective format for + + + align:start position:0% +think is the most effective format for +people to make progress in is it in + + align:start position:0% +people to make progress in is it in + + + align:start position:0% +people to make progress in is it in +universities would it be within + + align:start position:0% +universities would it be within + + + align:start position:0% +universities would it be within +corporations like what I is doing or + + align:start position:0% +corporations like what I is doing or + + + align:start position:0% +corporations like what I is doing or +what and also who do you think should be + + align:start position:0% +what and also who do you think should be + + + align:start position:0% +what and also who do you think should be +working on these + + align:start position:0% +working on these + + + align:start position:0% +working on these +problems well the + + align:start position:0% +problems well the + + + align:start position:0% +problems well the +problem it looks like this + + align:start position:0% +problem it looks like this + + + align:start position:0% +problem it looks like this +uh what do you call the IBM + + align:start position:0% +uh what do you call the IBM + + + align:start position:0% +uh what do you call the IBM +thing + + align:start position:0% +thing + + + align:start position:0% +thing +Watson that might be a good thing uh + + align:start position:0% +Watson that might be a good thing uh + + + align:start position:0% +Watson that might be a good thing uh +it's the + + align:start position:0% +it's the + + + align:start position:0% +it's the +first + + align:start position:0% +first + + + align:start position:0% +first +uh substantial AI + + align:start position:0% +uh substantial AI + + + align:start position:0% +uh substantial AI +project uh that is trying to combine + + align:start position:0% +project uh that is trying to combine + + + align:start position:0% +project uh that is trying to combine +more than one method but I don't know I + + align:start position:0% +more than one method but I don't know I + + + align:start position:0% +more than one method but I don't know I +actually haven't read uh even what's + + align:start position:0% +actually haven't read uh even what's + + + align:start position:0% +actually haven't read uh even what's +available about it + + align:start position:0% +available about it + + + align:start position:0% +available about it +but uh IBM did have ai researchers for + + align:start position:0% +but uh IBM did have ai researchers for + + + align:start position:0% +but uh IBM did have ai researchers for +the + + align:start position:0% +the + + + align:start position:0% +the +last + + align:start position:0% + + + + align:start position:0% + +uh there was a group in + + align:start position:0% +uh there was a group in + + + align:start position:0% +uh there was a group in +the middle + + align:start position:0% + + + + align:start position:0% + +1950s you've all read about this uh + + align:start position:0% +1950s you've all read about this uh + + + align:start position:0% +1950s you've all read about this uh +Dartmouth AI conference in + + align:start position:0% +Dartmouth AI conference in + + + align:start position:0% +Dartmouth AI conference in +1954 and uh that + + align:start position:0% +1954 and uh that + + + align:start position:0% +1954 and uh that +had uh McCarthy and me from around + + align:start position:0% +had uh McCarthy and me from around + + + align:start position:0% +had uh McCarthy and me from around +around here and Newell and Simon who + + align:start position:0% +around here and Newell and Simon who + + + align:start position:0% +around here and Newell and Simon who +were at Carnegie + + align:start position:0% +were at Carnegie + + + align:start position:0% +were at Carnegie +melon + + align:start position:0% + + + + align:start position:0% + +uh I think it was called Carnegie + + align:start position:0% +uh I think it was called Carnegie + + + align:start position:0% +uh I think it was called Carnegie +Institute of Technology then but + + align:start position:0% +Institute of Technology then but + + + align:start position:0% +Institute of Technology then but +whatever and uh it had a couple of + + align:start position:0% +whatever and uh it had a couple of + + + align:start position:0% +whatever and uh it had a couple of +people from IBM and it had about six or + + align:start position:0% +people from IBM and it had about six or + + + align:start position:0% +people from IBM and it had about six or +seven assorted + + align:start position:0% +seven assorted + + + align:start position:0% +seven assorted +individuals um from here and there so + + align:start position:0% +individuals um from here and there so + + + align:start position:0% +individuals um from here and there so +IBM uh had a guy named Nat Roch who had + + align:start position:0% +IBM uh had a guy named Nat Roch who had + + + align:start position:0% +IBM uh had a guy named Nat Roch who had +been involved in + + align:start position:0% +been involved in + + + align:start position:0% +been involved in +designing + + align:start position:0% +designing + + + align:start position:0% +designing +computers and he had a lot of good + + align:start position:0% +computers and he had a lot of good + + + align:start position:0% +computers and he had a lot of good +ideas and uh I had written a on paper a + + align:start position:0% +ideas and uh I had written a on paper a + + + align:start position:0% +ideas and uh I had written a on paper a +geometry theorem proving program and he + + align:start position:0% +geometry theorem proving program and he + + + align:start position:0% +geometry theorem proving program and he +started a project to actually put that + + align:start position:0% +started a project to actually put that + + + align:start position:0% +started a project to actually put that +on a computer and it uh so for a few + + align:start position:0% +on a computer and it uh so for a few + + + align:start position:0% +on a computer and it uh so for a few +years IBM had a few people working + + align:start position:0% +years IBM had a few people working + + + align:start position:0% +years IBM had a few people working +on uh different small AI projects + + align:start position:0% +on uh different small AI projects + + + align:start position:0% +on uh different small AI projects +then that + + align:start position:0% +then that + + + align:start position:0% +then that +disappeared after about 10 or 15 years + + align:start position:0% +disappeared after about 10 or 15 years + + + align:start position:0% +disappeared after about 10 or 15 years +and there was essentially no artificial + + align:start position:0% +and there was essentially no artificial + + + align:start position:0% +and there was essentially no artificial +very little programming research at IBM + + align:start position:0% +very little programming research at IBM + + + align:start position:0% +very little programming research at IBM +and they were mostly into hardware and + + align:start position:0% +and they were mostly into hardware and + + + align:start position:0% +and they were mostly into hardware and +Commercial software so + + align:start position:0% +Commercial software so + + + align:start position:0% +Commercial software so +forth uh this Watson thing is apparently + + align:start position:0% +forth uh this Watson thing is apparently + + + align:start position:0% +forth uh this Watson thing is apparently +three or four years old and it looks + + align:start position:0% +three or four years old and it looks + + + align:start position:0% +three or four years old and it looks +like a substantial project and I'm a + + align:start position:0% +like a substantial project and I'm a + + + align:start position:0% +like a substantial project and I'm a +little worried that uh since they're not + + align:start position:0% +little worried that uh since they're not + + + align:start position:0% +little worried that uh since they're not +very academic they might not have the + + align:start position:0% +very academic they might not have the + + + align:start position:0% +very academic they might not have the +idea that if you've discovered something + + align:start position:0% +idea that if you've discovered something + + + align:start position:0% +idea that if you've discovered something +the first thing you should do is publish + + align:start position:0% +the first thing you should do is publish + + + align:start position:0% +the first thing you should do is publish +all its details so that you get credit + + align:start position:0% +all its details so that you get credit + + + align:start position:0% +all its details so that you get credit +for it well + + align:start position:0% +for it well + + + align:start position:0% +for it well +uh it's hard not very many companies + + align:start position:0% +uh it's hard not very many companies + + + align:start position:0% +uh it's hard not very many companies +encourage the individuals getting credit + + align:start position:0% +encourage the individuals getting credit + + + align:start position:0% +encourage the individuals getting credit +and it looks like uh the guys in that + + align:start position:0% +and it looks like uh the guys in that + + + align:start position:0% +and it looks like uh the guys in that +project are are able to publish a + + align:start position:0% +project are are able to publish a + + + align:start position:0% +project are are able to publish a +substantial amount + + align:start position:0% +substantial amount + + + align:start position:0% +substantial amount +but I think the first sign of uh first + + align:start position:0% +but I think the first sign of uh first + + + align:start position:0% +but I think the first sign of uh first +good sign will be if they uh just dump + + align:start position:0% +good sign will be if they uh just dump + + + align:start position:0% +good sign will be if they uh just dump +their code out too and uh let people go + + align:start position:0% +their code out too and uh let people go + + + align:start position:0% +their code out too and uh let people go +over it and copy it and see if see if + + align:start position:0% +over it and copy it and see if see if + + + align:start position:0% +over it and copy it and see if see if +there's anything there they can + + align:start position:0% + + + + align:start position:0% + +use it's very rare for any AI researcher + + align:start position:0% +use it's very rare for any AI researcher + + + align:start position:0% +use it's very rare for any AI researcher +to use anyone else's code as far as I + + align:start position:0% +to use anyone else's code as far as I + + + align:start position:0% +to use anyone else's code as far as I +know it's almost never + + align:start position:0% + + + + align:start position:0% + +happened I don't + + align:start position:0% + + + + align:start position:0% + +know the best example almost was + + align:start position:0% +know the best example almost was + + + align:start position:0% +know the best example almost was +Winter's Shido program which uh was + + align:start position:0% +Winter's Shido program which uh was + + + align:start position:0% +Winter's Shido program which uh was +exported to Carnegie melon and to + + align:start position:0% +exported to Carnegie melon and to + + + align:start position:0% +exported to Carnegie melon and to +Stanford and both of them uh ran ran + + align:start position:0% +Stanford and both of them uh ran ran + + + align:start position:0% +Stanford and both of them uh ran ran +that program quite a bit but it wasn't I + + align:start position:0% +that program quite a bit but it wasn't I + + + align:start position:0% +that program quite a bit but it wasn't I +don't know why why it it died but + + align:start position:0% +don't know why why it it died but + + + align:start position:0% +don't know why why it it died but +apparently winegrad himself hadn't + + align:start position:0% +apparently winegrad himself hadn't + + + align:start position:0% +apparently winegrad himself hadn't +commented enough to remember how it + + align:start position:0% +commented enough to remember how it + + + align:start position:0% +commented enough to remember how it +worked and uh the beginners uh + + align:start position:0% +worked and uh the beginners uh + + + align:start position:0% +worked and uh the beginners uh +never uh got very far in improving + + align:start position:0% +never uh got very far in improving + + + align:start position:0% +never uh got very far in improving +either its robotic ability which + + align:start position:0% +either its robotic ability which + + + align:start position:0% +either its robotic ability which +was uh non-trivial or its linguistic + + align:start position:0% +was uh non-trivial or its linguistic + + + align:start position:0% +was uh non-trivial or its linguistic +ability which was unique uh it had + + align:start position:0% +ability which was unique uh it had + + + align:start position:0% +ability which was unique uh it had +better parsers and better semantic + + align:start position:0% +better parsers and better semantic + + + align:start position:0% +better parsers and better semantic +operations if only for a limited blocks + + align:start position:0% +operations if only for a limited blocks + + + align:start position:0% +operations if only for a limited blocks +Sr put the big red block on top of the + + align:start position:0% +Sr put the big red block on top of the + + + align:start position:0% +Sr put the big red block on top of the +little green block and uh it would do + + align:start position:0% +little green block and uh it would do + + + align:start position:0% +little green block and uh it would do +things like that so it + + align:start position:0% +things like that so it + + + align:start position:0% +things like that so it +uh and you could say put the block which + + align:start position:0% +uh and you could say put the block which + + + align:start position:0% +uh and you could say put the block which +is on top of the big red + + align:start position:0% +is on top of the big red + + + align:start position:0% +is on top of the big red +block uh and do such and such with it so + + align:start position:0% +block uh and do such and such with it so + + + align:start position:0% +block uh and do such and such with it so +it had uh fairly complicated ways to + + align:start position:0% +it had uh fairly complicated ways to + + + align:start position:0% +it had uh fairly complicated ways to +refer and refer to and describe things + + align:start position:0% +refer and refer to and describe things + + + align:start position:0% +refer and refer to and describe things +uh but it became a showpiece where you + + align:start position:0% +uh but it became a showpiece where you + + + align:start position:0% +uh but it became a showpiece where you +you could demonstrated it and after a + + align:start position:0% +you could demonstrated it and after a + + + align:start position:0% +you could demonstrated it and after a +few years uh you couldn't even has + + align:start position:0% +few years uh you couldn't even has + + + align:start position:0% +few years uh you couldn't even has +anyone tried + + align:start position:0% + + + + align:start position:0% + +it I haven't I've looked into it but it + + align:start position:0% +it I haven't I've looked into it but it + + + align:start position:0% +it I haven't I've looked into it but it +it's I mean it's in Mac list so it's not + + align:start position:0% +it's I mean it's in Mac list so it's not + + + align:start position:0% +it's I mean it's in Mac list so it's not +even there isn't even have to run it so + + align:start position:0% +even there isn't even have to run it so + + + align:start position:0% +even there isn't even have to run it so +there's no interpreter to run it yeah it + + align:start position:0% +there's no interpreter to run it yeah it + + + align:start position:0% +there's no interpreter to run it yeah it +should have had the whole package of + + align:start position:0% +should have had the whole package of + + + align:start position:0% +should have had the whole package of +course + + align:start position:0% +course + + + align:start position:0% +course +but because that program was big and + + align:start position:0% +but because that program was big and + + + align:start position:0% +but because that program was big and +maist would have only been 2% of the + + align:start position:0% +maist would have only been 2% of the + + + align:start position:0% +maist would have only been 2% of the +right the whole + + align:start position:0% + + + + align:start position:0% + +thing when you gret had quite a number + + align:start position:0% +thing when you gret had quite a number + + + align:start position:0% +thing when you gret had quite a number +of graduate students who finally left + + align:start position:0% +of graduate students who finally left + + + align:start position:0% +of graduate students who finally left +and did something else + + align:start position:0% +and did something else + + + align:start position:0% +and did something else +because the project was they just found + + align:start position:0% +because the project was they just found + + + align:start position:0% +because the project was they just found +it too hard to understand the code + + align:start position:0% + + + + align:start position:0% + +but who has an idea what to do next + + align:start position:0% +but who has an idea what to do next + + + align:start position:0% +but who has an idea what to do next +that's I bet you all have + + align:start position:0% +that's I bet you all have + + + align:start position:0% +that's I bet you all have +some fantasy of how to make machines + + align:start position:0% +some fantasy of how to make machines + + + align:start position:0% +some fantasy of how to make machines +smarter + + align:start position:0% + + + + align:start position:0% + +you could wake for the human brain + + align:start position:0% +you could wake for the human brain + + + align:start position:0% +you could wake for the human brain +people to + + align:start position:0% +people to + + + align:start position:0% +people to +yes I was thinking you could get more + + align:start position:0% +yes I was thinking you could get more + + + align:start position:0% +yes I was thinking you could get more +funding for science fiction + + align:start position:0% +funding for science fiction + + + align:start position:0% +funding for science fiction +writers and then hopefully one of them + + align:start position:0% +writers and then hopefully one of them + + + align:start position:0% +writers and then hopefully one of them +will come up with a brilliant + + align:start position:0% + + + + align:start position:0% + +idea ah yes Greg Egan had a + + align:start position:0% +idea ah yes Greg Egan had a + + + align:start position:0% +idea ah yes Greg Egan had a +computer how many of you know the name + + align:start position:0% +computer how many of you know the name + + + align:start position:0% +computer how many of you know the name +of Greg + + align:start position:0% +of Greg + + + align:start position:0% +of Greg +Egan uh look at + + align:start position:0% +Egan uh look at + + + align:start position:0% +Egan uh look at +his his web page has more exciting + + align:start position:0% +his his web page has more exciting + + + align:start position:0% +his his web page has more exciting +mathematical demonstrations and is as + + align:start position:0% +mathematical demonstrations and is as + + + align:start position:0% +mathematical demonstrations and is as +far as I know I've never I don't know + + align:start position:0% +far as I know I've never I don't know + + + align:start position:0% +far as I know I've never I don't know +anything like it uh well yes + + align:start position:0% + + + + align:start position:0% + +uh Ken + + align:start position:0% +uh Ken + + + align:start position:0% +uh Ken +plin uh type Ken perlin into your Google + + align:start position:0% +plin uh type Ken perlin into your Google + + + align:start position:0% +plin uh type Ken perlin into your Google +and get his web page and he + + align:start position:0% +and get his web page and he + + + align:start position:0% +and get his web page and he +has I think he must invent two or three + + align:start position:0% +has I think he must invent two or three + + + align:start position:0% +has I think he must invent two or three +incredibly brilliant small programs + + align:start position:0% +incredibly brilliant small programs + + + align:start position:0% +incredibly brilliant small programs +every week because there are quite a few + + align:start position:0% +every week because there are quite a few + + + align:start position:0% +every week because there are quite a few +hundred of these gorgeous demonstrations + + align:start position:0% +hundred of these gorgeous demonstrations + + + align:start position:0% +hundred of these gorgeous demonstrations +of one principle after + + align:start position:0% + + + + align:start position:0% + +another oh + + align:start position:0% +another oh + + + align:start position:0% +another oh +dear I didn't look ahead + + align:start position:0% +dear I didn't look ahead + + + align:start position:0% +dear I didn't look ahead +[Music] + + align:start position:0% + + + + align:start position:0% + +another feature of Greg Egan is that he + + align:start position:0% +another feature of Greg Egan is that he + + + align:start position:0% +another feature of Greg Egan is that he +read the Society of Mind and worked a + + align:start position:0% +read the Society of Mind and worked a + + + align:start position:0% +read the Society of Mind and worked a +lot of ideas that I hadn't thought of + + align:start position:0% +lot of ideas that I hadn't thought of + + + align:start position:0% +lot of ideas that I hadn't thought of +into some of his stories so uh + + align:start position:0% + + + + align:start position:0% + +but another feature of him is that no + + align:start position:0% +but another feature of him is that no + + + align:start position:0% +but another feature of him is that no +one has ever met + + align:start position:0% + + + + align:start position:0% + +him uh that is if you knock on his door + + align:start position:0% +him uh that is if you knock on his door + + + align:start position:0% +him uh that is if you knock on his door +which is in Perth it he won't answer + + align:start position:0% +which is in Perth it he won't answer + + + align:start position:0% +which is in Perth it he won't answer +and uh I was discussing this with Greg + + align:start position:0% +and uh I was discussing this with Greg + + + align:start position:0% +and uh I was discussing this with Greg +Benford apparently there are a couple of + + align:start position:0% +Benford apparently there are a couple of + + + align:start position:0% +Benford apparently there are a couple of +people who have seen him but uh nobody + + align:start position:0% +people who have seen him but uh nobody + + + align:start position:0% +people who have seen him but uh nobody +knows anyone who knows him + + align:start position:0% + + + + align:start position:0% + +you could do + + align:start position:0% +you could do + + + align:start position:0% +you could do +that maybe that's the way to get a lot + + align:start position:0% + + + + align:start position:0% + +done uh make a list of all your friends + + align:start position:0% +done uh make a list of all your friends + + + align:start position:0% +done uh make a list of all your friends +and abandon + + align:start position:0% + + + + align:start position:0% + +them just think of all the free time + + align:start position:0% +them just think of all the free time + + + align:start position:0% +them just think of all the free time +you'll + + align:start position:0% + + + + align:start position:0% + +have there any other Gregs oh well Greg + + align:start position:0% +have there any other Gregs oh well Greg + + + align:start position:0% +have there any other Gregs oh well Greg +Benford + + align:start position:0% + + + + align:start position:0% + +but this isn't fair I've lost the big + + align:start position:0% + + + + align:start position:0% + +chalk among the science fiction writers + + align:start position:0% +chalk among the science fiction writers + + + align:start position:0% +chalk among the science fiction writers +there are only a few who actually know a + + align:start position:0% +there are only a few who actually know a + + + align:start position:0% +there are only a few who actually know a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +science + + align:start position:0% +science + + + align:start position:0% +science +uh uh Benford is quite a good physicist + + align:start position:0% +uh uh Benford is quite a good physicist + + + align:start position:0% +uh uh Benford is quite a good physicist +and uh knows a lot and publishes serious + + align:start position:0% +and uh knows a lot and publishes serious + + + align:start position:0% +and uh knows a lot and publishes serious +physics + + align:start position:0% +physics + + + align:start position:0% +physics +papers um Larry + + align:start position:0% +papers um Larry + + + align:start position:0% +papers um Larry +nien uh knew quite a bit of science but + + align:start position:0% +nien uh knew quite a bit of science but + + + align:start position:0% +nien uh knew quite a bit of science but +uh was never practicing one and so in + + align:start position:0% +uh was never practicing one and so in + + + align:start position:0% +uh was never practicing one and so in +His science fiction there occasional + + align:start position:0% +His science fiction there occasional + + + align:start position:0% +His science fiction there occasional +technical + + align:start position:0% +technical + + + align:start position:0% +technical +errors like in Ring + + align:start position:0% +errors like in Ring + + + align:start position:0% +errors like in Ring +World ring world was a big ring + + align:start position:0% +World ring world was a big ring + + + align:start position:0% +World ring world was a big ring +shaped planet around the + + align:start position:0% +shaped planet around the + + + align:start position:0% +shaped planet around the +Sun + + align:start position:0% + + + + align:start position:0% + +and so here's the Sun and here's this + + align:start position:0% + + + + align:start position:0% + +ring and the ring is about 8,000 miles + + align:start position:0% +ring and the ring is about 8,000 miles + + + align:start position:0% +ring and the ring is about 8,000 miles +wide and goes all the way around uh its + + align:start position:0% +wide and goes all the way around uh its + + + align:start position:0% +wide and goes all the way around uh its +sun in something like Earth's + + align:start position:0% +sun in something like Earth's + + + align:start position:0% +sun in something like Earth's +orbit uh which means that it has an area + + align:start position:0% +orbit uh which means that it has an area + + + align:start position:0% +orbit uh which means that it has an area +of the orbit + + align:start position:0% +of the orbit + + + align:start position:0% +of the orbit +of 100,000 + + align:start position:0% +of 100,000 + + + align:start position:0% +of 100,000 +Earths U well Larry didn't realize that + + align:start position:0% +Earths U well Larry didn't realize that + + + align:start position:0% +Earths U well Larry didn't realize that +there was a + + align:start position:0% +there was a + + + align:start position:0% +there was a +bug and + + align:start position:0% +bug and + + + align:start position:0% +bug and +uh if you make a ring that's rotating + + align:start position:0% +uh if you make a ring that's rotating + + + align:start position:0% +uh if you make a ring that's rotating +around the Sun well first of all there's + + align:start position:0% +around the Sun well first of all there's + + + align:start position:0% +around the Sun well first of all there's +no particular reason why it should + + align:start position:0% +no particular reason why it should + + + align:start position:0% +no particular reason why it should +rotate uh but uh if it didn't it would + + align:start position:0% +rotate uh but uh if it didn't it would + + + align:start position:0% +rotate uh but uh if it didn't it would +squash + + align:start position:0% +squash + + + align:start position:0% +squash +uh but it's not gravitationally stable + + align:start position:0% +uh but it's not gravitationally stable + + + align:start position:0% +uh but it's not gravitationally stable +so as soon as it gets slightly off + + align:start position:0% +so as soon as it gets slightly off + + + align:start position:0% +so as soon as it gets slightly off +center then uh this part if this is + + align:start position:0% +center then uh this part if this is + + + align:start position:0% +center then uh this part if this is +closer it gets folded in and so finally + + align:start position:0% +closer it gets folded in and so finally + + + align:start position:0% +closer it gets folded in and so finally +one part of it falls into the sun and + + align:start position:0% +one part of it falls into the sun and + + + align:start position:0% +one part of it falls into the sun and +the rest follows it so in the sequel to + + align:start position:0% +the rest follows it so in the sequel to + + + align:start position:0% +the rest follows it so in the sequel to +Ring World some physicist pointed this + + align:start position:0% +Ring World some physicist pointed this + + + align:start position:0% +Ring World some physicist pointed this +out to Larry Nan and + + align:start position:0% +out to Larry Nan and + + + align:start position:0% +out to Larry Nan and +so + + align:start position:0% +so + + + align:start position:0% +so +uh now Larry nien + + align:start position:0% + + + + align:start position:0% + +had he had little + + align:start position:0% + + + + align:start position:0% + +wires I forget what they're connected to + + align:start position:0% +wires I forget what they're connected to + + + align:start position:0% +wires I forget what they're connected to +does + + align:start position:0% +does + + + align:start position:0% +does +anybody they're made of something called + + align:start position:0% +anybody they're made of something called + + + align:start position:0% +anybody they're made of something called +scri which is 10 to the 50th times + + align:start position:0% +scri which is 10 to the 50th times + + + align:start position:0% +scri which is 10 to the 50th times +stronger than anything + + align:start position:0% +stronger than anything + + + align:start position:0% +stronger than anything +real because it's pretty hard to hold + + align:start position:0% +real because it's pretty hard to hold + + + align:start position:0% +real because it's pretty hard to hold +the thing that + + align:start position:0% +the thing that + + + align:start position:0% +the thing that +massive and so oh oh then they're little + + align:start position:0% +massive and so oh oh then they're little + + + align:start position:0% +massive and so oh oh then they're little +Jets which have been built by the + + align:start position:0% +Jets which have been built by the + + + align:start position:0% +Jets which have been built by the +original + + align:start position:0% +original + + + align:start position:0% +original +inhabitants now forgot all the geometry + + align:start position:0% +inhabitants now forgot all the geometry + + + align:start position:0% +inhabitants now forgot all the geometry +but uh so now there's an active system + + align:start position:0% +but uh so now there's an active system + + + align:start position:0% +but uh so now there's an active system +for maintaining the Ring World to not + + align:start position:0% +for maintaining the Ring World to not + + + align:start position:0% +for maintaining the Ring World to not +fall into the sun and the sequel the uh + + align:start position:0% +fall into the sun and the sequel the uh + + + align:start position:0% +fall into the sun and the sequel the uh +this was built by some disappeared + + align:start position:0% +this was built by some disappeared + + + align:start position:0% +this was built by some disappeared +aliens millions of years ago and the + + align:start position:0% +aliens millions of years ago and the + + + align:start position:0% +aliens millions of years ago and the +hardware is beginning to break down so + + align:start position:0% +hardware is beginning to break down so + + + align:start position:0% +hardware is beginning to break down so +they need to find an alien race with + + align:start position:0% +they need to find an alien race with + + + align:start position:0% +they need to find an alien race with +enough engineering to fix it and blah + + align:start position:0% +enough engineering to fix it and blah + + + align:start position:0% +enough engineering to fix it and blah +blah any anyway Larry nien is awfully + + align:start position:0% +blah any anyway Larry nien is awfully + + + align:start position:0% +blah any anyway Larry nien is awfully +good at making up things with a pretty + + align:start position:0% +good at making up things with a pretty + + + align:start position:0% +good at making up things with a pretty +good scientific + + align:start position:0% +good scientific + + + align:start position:0% +good scientific +background and then when he makes a + + align:start position:0% +background and then when he makes a + + + align:start position:0% +background and then when he makes a +mistake uh he writes a sequel to correct + + align:start position:0% +mistake uh he writes a sequel to correct + + + align:start position:0% +mistake uh he writes a sequel to correct +it so uh maybe that's actually better + + align:start position:0% +it so uh maybe that's actually better + + + align:start position:0% +it so uh maybe that's actually better +than getting it right the first + + align:start position:0% + + + + align:start position:0% + +time he has a machine you know the + + align:start position:0% +time he has a machine you know the + + + align:start position:0% +time he has a machine you know the +Transporters in Star Trek + + align:start position:0% +Transporters in Star Trek + + + align:start position:0% +Transporters in Star Trek +uh nien Transporters are nice because + + align:start position:0% +uh nien Transporters are nice because + + + align:start position:0% +uh nien Transporters are nice because +they take out all the + + align:start position:0% +they take out all the + + + align:start position:0% +they take out all the +chemicals uh in your cells that + + align:start position:0% +chemicals uh in your cells that + + + align:start position:0% +chemicals uh in your cells that +shouldn't be there so once they have + + align:start position:0% +shouldn't be there so once they have + + + align:start position:0% +shouldn't be there so once they have +Transporters automatically the people + + align:start position:0% +Transporters automatically the people + + + align:start position:0% +Transporters automatically the people +now become nearly Immortal because if + + align:start position:0% +now become nearly Immortal because if + + + align:start position:0% +now become nearly Immortal because if +you're being scanned and reconstructed + + align:start position:0% +you're being scanned and reconstructed + + + align:start position:0% +you're being scanned and reconstructed +by a transporter it might as well fix + + align:start position:0% +by a transporter it might as well fix + + + align:start position:0% +by a transporter it might as well fix +all your bugs while it's at + + align:start position:0% +all your bugs while it's at + + + align:start position:0% +all your bugs while it's at +it + + align:start position:0% +it + + + align:start position:0% +it +so and anyway uh there's a good idea on + + align:start position:0% +so and anyway uh there's a good idea on + + + align:start position:0% +so and anyway uh there's a good idea on +every page of this guy uh even if it's + + align:start position:0% +every page of this guy uh even if it's + + + align:start position:0% +every page of this guy uh even if it's +wrong + + align:start position:0% +wrong + + + align:start position:0% +wrong +so when I read a regular + + align:start position:0% +so when I read a regular + + + align:start position:0% +so when I read a regular +novel which is very rare there's usually + + align:start position:0% +novel which is very rare there's usually + + + align:start position:0% +novel which is very rare there's usually +a good idea every chapter + + align:start position:0% +a good idea every chapter + + + align:start position:0% +a good idea every chapter +maybe but + + align:start position:0% +maybe but + + + align:start position:0% +maybe but +uh I didn't write Larry nen's name + + align:start position:0% +uh I didn't write Larry nen's name + + + align:start position:0% +uh I didn't write Larry nen's name +probably he had more ideas than any + + align:start position:0% +probably he had more ideas than any + + + align:start position:0% +probably he had more ideas than any +other writer but they're not all + + align:start position:0% + + + + align:start position:0% + +correct so how many of you are going to + + align:start position:0% +correct so how many of you are going to + + + align:start position:0% +correct so how many of you are going to +pursue AI + + align:start position:0% + + + + align:start position:0% + +or are you going to work on trying to + + align:start position:0% +or are you going to work on trying to + + + align:start position:0% +or are you going to work on trying to +make + + align:start position:0% + + + + align:start position:0% + +smarter here's + + align:start position:0% + + + + align:start position:0% + +one we sure could use + + align:start position:0% +one we sure could use + + + align:start position:0% +one we sure could use +them I'm sort of amused at the + + align:start position:0% + + + + align:start position:0% + +uh the there are a couple of + + align:start position:0% +uh the there are a couple of + + + align:start position:0% +uh the there are a couple of +transhumanist communities whatever that + + align:start position:0% +transhumanist communities whatever that + + + align:start position:0% +transhumanist communities whatever that +means and they're worried that the AI + + align:start position:0% +means and they're worried that the AI + + + align:start position:0% +means and they're worried that the AI +will uh as many science fiction writers + + align:start position:0% +will uh as many science fiction writers + + + align:start position:0% +will uh as many science fiction writers +have uh be hostile and take over and uh + + align:start position:0% +have uh be hostile and take over and uh + + + align:start position:0% +have uh be hostile and take over and uh +want everything for itself and so uh + + align:start position:0% +want everything for itself and so uh + + + align:start position:0% +want everything for itself and so uh +there are serious discussions on how to + + align:start position:0% +there are serious discussions on how to + + + align:start position:0% +there are serious discussions on how to +make friendly + + align:start position:0% +make friendly + + + align:start position:0% +make friendly +AIS and of course the master of that was + + align:start position:0% +AIS and of course the master of that was + + + align:start position:0% +AIS and of course the master of that was +Isaac + + align:start position:0% +Isaac + + + align:start position:0% +Isaac +aimof who said that uh a robot should + + align:start position:0% +aimof who said that uh a robot should + + + align:start position:0% +aimof who said that uh a robot should +always put its + + align:start position:0% +always put its + + + align:start position:0% +always put its +interests uh beneath those of its owner + + align:start position:0% +interests uh beneath those of its owner + + + align:start position:0% +interests uh beneath those of its owner +or whatever how many of you know + + align:start position:0% +or whatever how many of you know + + + align:start position:0% +or whatever how many of you know +asimov's + + align:start position:0% +asimov's + + + align:start position:0% +asimov's +laws and then there was the fourth law + + align:start position:0% +laws and then there was the fourth law + + + align:start position:0% +laws and then there was the fourth law +that he + + align:start position:0% +that he + + + align:start position:0% +that he +had to make which is that it's all right + + align:start position:0% +had to make which is that it's all right + + + align:start position:0% +had to make which is that it's all right +to harm a human if if if it's to save a + + align:start position:0% +to harm a human if if if it's to save a + + + align:start position:0% +to harm a human if if if it's to save a +large number of + + align:start position:0% +large number of + + + align:start position:0% +large number of +others uh from being harmed + + align:start position:0% + + + + align:start position:0% + +and but you know + + align:start position:0% +and but you know + + + align:start position:0% +and but you know +uh it's like saying we shouldn't eat + + align:start position:0% +uh it's like saying we shouldn't eat + + + align:start position:0% +uh it's like saying we shouldn't eat +meat it's very hard to + + align:start position:0% +meat it's very hard to + + + align:start position:0% +meat it's very hard to +make up ethical principles that are + + align:start position:0% + + + + align:start position:0% + +foolproof I'm not sure what the uh the + + align:start position:0% +foolproof I'm not sure what the uh the + + + align:start position:0% +foolproof I'm not sure what the uh the +safe AI people have as their asof + + align:start position:0% + + + + align:start position:0% + +laws but if you walk around the uh AI + + align:start position:0% +laws but if you walk around the uh AI + + + align:start position:0% +laws but if you walk around the uh AI +world + + align:start position:0% +world + + + align:start position:0% +world +today it's hard to take ser iously the + + align:start position:0% +today it's hard to take ser iously the + + + align:start position:0% +today it's hard to take ser iously the +idea that they might form some sort of + + align:start position:0% +idea that they might form some sort of + + + align:start position:0% +idea that they might form some sort of +threat of course it could happen + + align:start position:0% +threat of course it could happen + + + align:start position:0% +threat of course it could happen +overnight but + + align:start position:0% + + + + align:start position:0% + +uh well we discussed the big threat the + + align:start position:0% +uh well we discussed the big threat the + + + align:start position:0% +uh well we discussed the big threat the +other day when somebody making a virus + + align:start position:0% +other day when somebody making a virus + + + align:start position:0% +other day when somebody making a virus +that kills + + align:start position:0% + + + + align:start position:0% + +everything that's the road toward + + align:start position:0% +everything that's the road toward + + + align:start position:0% +everything that's the road toward +nanotechnology + + align:start position:0% + + + + align:start position:0% + +I can't get them to propose + + align:start position:0% +I can't get them to propose + + + align:start position:0% +I can't get them to propose +anything what happens in your class Pat + + align:start position:0% +anything what happens in your class Pat + + + align:start position:0% +anything what happens in your class Pat +I haven't been there for a long + + align:start position:0% + + + + align:start position:0% + +time I don't know + + align:start position:0% + + + + align:start position:0% + +yes you think efforts to augment human + + align:start position:0% + + + + align:start position:0% + +intell people more + + align:start position:0% + + + + align:start position:0% + +intelligent that's a great question + + align:start position:0% +intelligent that's a great question + + + align:start position:0% +intelligent that's a great question +because uh we're + + align:start position:0% +because uh we're + + + align:start position:0% +because uh we're +probably fairly close to the technology + + align:start position:0% +probably fairly close to the technology + + + align:start position:0% +probably fairly close to the technology +to do do something exciting in that + + align:start position:0% +to do do something exciting in that + + + align:start position:0% +to do do something exciting in that +direction except that we're afraid to + + align:start position:0% +direction except that we're afraid to + + + align:start position:0% +direction except that we're afraid to +because it seems to me + + align:start position:0% +because it seems to me + + + align:start position:0% +because it seems to me +that suppose you just wanted to do + + align:start position:0% +that suppose you just wanted to do + + + align:start position:0% +that suppose you just wanted to do +something modest like + + align:start position:0% +something modest like + + + align:start position:0% +something modest like +improve some person's + + align:start position:0% +improve some person's + + + align:start position:0% +improve some person's +memory I'll bet that with a few million + + align:start position:0% +memory I'll bet that with a few million + + + align:start position:0% +memory I'll bet that with a few million +dollars + + align:start position:0% +dollars + + + align:start position:0% +dollars +and + + align:start position:0% +and + + + align:start position:0% +and +uh I don't know how many + + align:start position:0% +uh I don't know how many + + + align:start position:0% +uh I don't know how many +years you could do something without + + align:start position:0% +years you could do something without + + + align:start position:0% +years you could do something without +understanding how the brain works + + align:start position:0% +understanding how the brain works + + + align:start position:0% +understanding how the brain works +to attach uh accessories to + + align:start position:0% +to attach uh accessories to + + + align:start position:0% +to attach uh accessories to +it uh I think I mentioned brindley's + + align:start position:0% +it uh I think I mentioned brindley's + + + align:start position:0% +it uh I think I mentioned brindley's +first experiment + + align:start position:0% +first experiment + + + align:start position:0% +first experiment +on + + align:start position:0% + + + + align:start position:0% + +on trying to restore Vision to a blind + + align:start position:0% + + + + align:start position:0% + +person + + align:start position:0% +person + + + align:start position:0% +person +uh I think I mentioned that last time + + align:start position:0% + + + + align:start position:0% + +l e y I + + align:start position:0% +l e y I + + + align:start position:0% +l e y I +think + + align:start position:0% + + + + align:start position:0% + +uh so what he did + + align:start position:0% + + + + align:start position:0% + +was here's his + + align:start position:0% +was here's his + + + align:start position:0% +was here's his +secretary who's + + align:start position:0% +secretary who's + + + align:start position:0% +secretary who's +blind and here's her aital + + align:start position:0% +blind and here's her aital + + + align:start position:0% +blind and here's her aital +lobe + + align:start position:0% +lobe + + + align:start position:0% +lobe +which of the brain + + align:start position:0% +which of the brain + + + align:start position:0% +which of the brain +and here's this area which is the + + align:start position:0% +and here's this area which is the + + + align:start position:0% +and here's this area which is the +primary uh + + align:start position:0% +primary uh + + + align:start position:0% +primary uh +visual I think it's called area 17 for + + align:start position:0% +visual I think it's called area 17 for + + + align:start position:0% +visual I think it's called area 17 for +no good + + align:start position:0% +no good + + + align:start position:0% +no good +reason that's the place where the + + align:start position:0% +reason that's the place where the + + + align:start position:0% +reason that's the place where the +signals get into the brain from the + + align:start position:0% +signals get into the brain from the + + + align:start position:0% +signals get into the brain from the +eye stupid isn't + + align:start position:0% +eye stupid isn't + + + align:start position:0% +eye stupid isn't +it here's the eye and here's the optic + + align:start position:0% +it here's the eye and here's the optic + + + align:start position:0% +it here's the eye and here's the optic +nerve and then here's some other stuff + + align:start position:0% +nerve and then here's some other stuff + + + align:start position:0% +nerve and then here's some other stuff +and it's all the way back + + align:start position:0% +and it's all the way back + + + align:start position:0% +and it's all the way back +here I presume this is because we used + + align:start position:0% +here I presume this is because we used + + + align:start position:0% +here I presume this is because we used +to be an octopus or something and the + + align:start position:0% +to be an octopus or something and the + + + align:start position:0% +to be an octopus or something and the +eye was here but uh + + align:start position:0% +eye was here but uh + + + align:start position:0% +eye was here but uh +anyway what's + + align:start position:0% +anyway what's + + + align:start position:0% +anyway what's +more the wires cross and all sorts of + + align:start position:0% +more the wires cross and all sorts of + + + align:start position:0% +more the wires cross and all sorts of +things but anyway so here's this piece + + align:start position:0% +things but anyway so here's this piece + + + align:start position:0% +things but anyway so here's this piece +of brain and what Brindley does is he + + align:start position:0% +of brain and what Brindley does is he + + + align:start position:0% +of brain and what Brindley does is he +makes a little uh Gadget with 64 + + align:start position:0% + + + + align:start position:0% + +electrodes and I forgotten the details + + align:start position:0% +electrodes and I forgotten the details + + + align:start position:0% +electrodes and I forgotten the details +but I think that these + + align:start position:0% +but I think that these + + + align:start position:0% +but I think that these +are actually uh has little + + align:start position:0% +are actually uh has little + + + align:start position:0% +are actually uh has little +coils I believe that the thing was + + align:start position:0% +coils I believe that the thing was + + + align:start position:0% +coils I believe that the thing was +there's no wire coming out of her head + + align:start position:0% +there's no wire coming out of her head + + + align:start position:0% +there's no wire coming out of her head +uh but these little uh wires little + + align:start position:0% +uh but these little uh wires little + + + align:start position:0% +uh but these little uh wires little +coils and electrodes are in uh + + align:start position:0% +coils and electrodes are in uh + + + align:start position:0% +coils and electrodes are in uh +this is in the + + align:start position:0% +this is in the + + + align:start position:0% +this is in the +1950s and silicone had just + + align:start position:0% +1950s and silicone had just + + + align:start position:0% +1950s and silicone had just +appeared uh and it looked pretty + + align:start position:0% +appeared uh and it looked pretty + + + align:start position:0% +appeared uh and it looked pretty +harmless so there's this a little pad of + + align:start position:0% +harmless so there's this a little pad of + + + align:start position:0% +harmless so there's this a little pad of +silicone he has to take the bone off the + + align:start position:0% +silicone he has to take the bone off the + + + align:start position:0% +silicone he has to take the bone off the +back of her skull which is risky and uh + + align:start position:0% +back of her skull which is risky and uh + + + align:start position:0% +back of her skull which is risky and uh +so there's the + + align:start position:0% +so there's the + + + align:start position:0% +so there's the +gadget and uh as I said uh when you + + align:start position:0% +gadget and uh as I said uh when you + + + align:start position:0% +gadget and uh as I said uh when you +stimulate + + align:start position:0% +stimulate + + + align:start position:0% +stimulate +these + + align:start position:0% +these + + + align:start position:0% +these +uh I believe 48 of them worked + + align:start position:0% +uh I believe 48 of them worked + + + align:start position:0% +uh I believe 48 of them worked +and about eight of them + + align:start position:0% +and about eight of them + + + align:start position:0% +and about eight of them +hurt and uh about eight of them didn't + + align:start position:0% +hurt and uh about eight of them didn't + + + align:start position:0% +hurt and uh about eight of them didn't +do anything but if you fired up this one + + align:start position:0% +do anything but if you fired up this one + + + align:start position:0% +do anything but if you fired up this one +then she described it as being like half + + align:start position:0% +then she described it as being like half + + + align:start position:0% +then she described it as being like half +a match stick at arms length and they + + align:start position:0% +a match stick at arms length and they + + + align:start position:0% +a match stick at arms length and they +were little bars which is interesting + + align:start position:0% +were little bars which is interesting + + + align:start position:0% +were little bars which is interesting +they were not little round dots but + + align:start position:0% +they were not little round dots but + + + align:start position:0% +they were not little round dots but +there were enough of them that she could + + align:start position:0% +there were enough of them that she could + + + align:start position:0% +there were enough of them that she could +read letters one at a time and so that's + + align:start position:0% +read letters one at a time and so that's + + + align:start position:0% +read letters one at a time and so that's +the 1950s and as far as I know it's + + align:start position:0% +the 1950s and as far as I know it's + + + align:start position:0% +the 1950s and as far as I know it's +never been done + + align:start position:0% +never been done + + + align:start position:0% +never been done +again uh maybe there some way to look + + align:start position:0% +again uh maybe there some way to look + + + align:start position:0% +again uh maybe there some way to look +that + + align:start position:0% +that + + + align:start position:0% +that +up yes so they I think improveed the + + align:start position:0% +up yes so they I think improveed the + + + align:start position:0% +up yes so they I think improveed the +memory of rats recently of rats yeah + + align:start position:0% +memory of rats recently of rats yeah + + + align:start position:0% +memory of rats recently of rats yeah +they turn off and turn off okay yeah uh + + align:start position:0% +they turn off and turn off okay yeah uh + + + align:start position:0% +they turn off and turn off okay yeah uh +but anyway I suspect that uh if you got + + align:start position:0% +but anyway I suspect that uh if you got + + + align:start position:0% +but anyway I suspect that uh if you got +permission to + + align:start position:0% +permission to + + + align:start position:0% +permission to +try I'll bet you could put a th000 + + align:start position:0% +try I'll bet you could put a th000 + + + align:start position:0% +try I'll bet you could put a th000 +electrodes + + align:start position:0% +electrodes + + + align:start position:0% +electrodes +uh maybe in a couple of places on the + + align:start position:0% +uh maybe in a couple of places on the + + + align:start position:0% +uh maybe in a couple of places on the +cortex and just poke around and I'll bet + + align:start position:0% +cortex and just poke around and I'll bet + + + align:start position:0% +cortex and just poke around and I'll bet +that you could do it without much + + align:start position:0% +that you could do it without much + + + align:start position:0% +that you could do it without much +danger and + + align:start position:0% +danger and + + + align:start position:0% +danger and +eventually uh get enough inputs and + + align:start position:0% +eventually uh get enough inputs and + + + align:start position:0% +eventually uh get enough inputs and +outputs uh to hook it up to something + + align:start position:0% +outputs uh to hook it up to something + + + align:start position:0% +outputs uh to hook it up to something +stupid like the Oxford + + align:start position:0% +stupid like the Oxford + + + align:start position:0% +stupid like the Oxford +dictionary which would be about that + + align:start position:0% +dictionary which would be about that + + + align:start position:0% +dictionary which would be about that +big and uh + + align:start position:0% +big and uh + + + align:start position:0% +big and uh +or make it a memory retrieval system + + align:start position:0% +or make it a memory retrieval system + + + align:start position:0% +or make it a memory retrieval system +where you + + align:start position:0% +where you + + + align:start position:0% +where you +think I I don't know what you'd think + + align:start position:0% +think I I don't know what you'd think + + + align:start position:0% +think I I don't know what you'd think +but uh + + align:start position:0% +but uh + + + align:start position:0% +but uh +people having this gadget for in their + + align:start position:0% +people having this gadget for in their + + + align:start position:0% +people having this gadget for in their +head for a long time with a with a + + align:start position:0% +head for a long time with a with a + + + align:start position:0% +head for a long time with a with a +screen producing outputs would learn how + + align:start position:0% +screen producing outputs would learn how + + + align:start position:0% +screen producing outputs would learn how +to control some of those little spots + + align:start position:0% +to control some of those little spots + + + align:start position:0% +to control some of those little spots +and uh then another part of their brain + + align:start position:0% +and uh then another part of their brain + + + align:start position:0% +and uh then another part of their brain +would learn to control groups of them + + align:start position:0% +would learn to control groups of them + + + align:start position:0% +would learn to control groups of them +and so forth and maybe after a few days + + align:start position:0% +and so forth and maybe after a few days + + + align:start position:0% +and so forth and maybe after a few days +or weeks or + + align:start position:0% +or weeks or + + + align:start position:0% +or weeks or +months uh you'd be able to operate this + + align:start position:0% +months uh you'd be able to operate this + + + align:start position:0% +months uh you'd be able to operate this +uh as like the touch screen on your + + align:start position:0% +uh as like the touch screen on your + + + align:start position:0% +uh as like the touch screen on your +iPhone and uh uh it would provide you + + align:start position:0% +iPhone and uh uh it would provide you + + + align:start position:0% +iPhone and uh uh it would provide you +with a huge uh inexhaustible amount of + + align:start position:0% +with a huge uh inexhaustible amount of + + + align:start position:0% +with a huge uh inexhaustible amount of +memory that that uh and for one in a + + align:start position:0% +memory that that uh and for one in a + + + align:start position:0% +memory that that uh and for one in a +dozen people it it might produce outputs + + align:start position:0% +dozen people it it might produce outputs + + + align:start position:0% +dozen people it it might produce outputs +that uh get right into your mind in some + + align:start position:0% +that uh get right into your mind in some + + + align:start position:0% +that uh get right into your mind in some +graphic or auditory or uh unspeakably + + align:start position:0% +graphic or auditory or uh unspeakably + + + align:start position:0% +graphic or auditory or uh unspeakably +Alien sense uh and you'd know know + + align:start position:0% +Alien sense uh and you'd know know + + + align:start position:0% +Alien sense uh and you'd know know +something that you didn't know before so + + align:start position:0% +something that you didn't know before so + + + align:start position:0% +something that you didn't know before so +that would be very thrilling uh area and + + align:start position:0% +that would be very thrilling uh area and + + + align:start position:0% +that would be very thrilling uh area and +there lots of epileptics who are having + + align:start position:0% +there lots of epileptics who are having + + + align:start position:0% +there lots of epileptics who are having +pieces of their brain removed + + align:start position:0% +pieces of their brain removed + + + align:start position:0% +pieces of their brain removed +because uh it's saving their life and it + + align:start position:0% +because uh it's saving their life and it + + + align:start position:0% +because uh it's saving their life and it +would be almost risk-free to slide this + + align:start position:0% +would be almost risk-free to slide this + + + align:start position:0% +would be almost risk-free to slide this +little Gadget in while you're at it + + align:start position:0% +little Gadget in while you're at it + + + align:start position:0% +little Gadget in while you're at it +because now it's 60 years later and we + + align:start position:0% +because now it's 60 years later and we + + + align:start position:0% +because now it's 60 years later and we +know which kinds of silicone implants + + align:start position:0% +know which kinds of silicone implants + + + align:start position:0% +know which kinds of silicone implants +are tolerated and I'm sure there are + + align:start position:0% +are tolerated and I'm sure there are + + + align:start position:0% +are tolerated and I'm sure there are +other things what substances can you put + + align:start position:0% +other things what substances can you put + + + align:start position:0% +other things what substances can you put +in the body that don't irritate it must + + align:start position:0% +in the body that don't irritate it must + + + align:start position:0% +in the body that don't irritate it must +be quite a + + align:start position:0% +be quite a + + + align:start position:0% +be quite a +few I mean in a sense we're sort of + + align:start position:0% +few I mean in a sense we're sort of + + + align:start position:0% +few I mean in a sense we're sort of +already doing this like bring + + align:start position:0% +already doing this like bring + + + align:start position:0% +already doing this like bring +augmentation thing right ex like with + + align:start position:0% +augmentation thing right ex like with + + + align:start position:0% +augmentation thing right ex like with +our computers or with our smartphones + + align:start position:0% +our computers or with our smartphones + + + align:start position:0% +our computers or with our smartphones +except for the interface between us and + + align:start position:0% +except for the interface between us and + + + align:start position:0% +except for the interface between us and +the devices a lot Fier this is just like + + align:start position:0% +the devices a lot Fier this is just like + + + align:start position:0% +the devices a lot Fier this is just like +more direct whereas right now it's like + + align:start position:0% +more direct whereas right now it's like + + + align:start position:0% +more direct whereas right now it's like +we have to like I guess use our bodies + + align:start position:0% +we have to like I guess use our bodies + + + align:start position:0% +we have to like I guess use our bodies +actuate the machine and then like use + + align:start position:0% +actuate the machine and then like use + + + align:start position:0% +actuate the machine and then like use +our sentences to get the information + + align:start position:0% +our sentences to get the information + + + align:start position:0% +our sentences to get the information +back into our mind right and we're being + + align:start position:0% +back into our mind right and we're being + + + align:start position:0% +back into our mind right and we're being +very sluggish about it I don't see why + + align:start position:0% +very sluggish about it I don't see why + + + align:start position:0% +very sluggish about it I don't see why +you couldn't put little pads in the toes + + align:start position:0% +you couldn't put little pads in the toes + + + align:start position:0% +you couldn't put little pads in the toes +of your shoes so you wouldn't need a + + align:start position:0% +of your shoes so you wouldn't need a + + + align:start position:0% +of your shoes so you wouldn't need a +mouse or they have like tongue + + align:start position:0% +mouse or they have like tongue + + + align:start position:0% +mouse or they have like tongue +interfaces where like well yes tongue + + align:start position:0% +interfaces where like well yes tongue + + + align:start position:0% +interfaces where like well yes tongue +displays um where it sort of um send + + align:start position:0% +displays um where it sort of um send + + + align:start position:0% +displays um where it sort of um send +like electric signals um on your tongue + + align:start position:0% +like electric signals um on your tongue + + + align:start position:0% +like electric signals um on your tongue +in a 2d grid so that you can like I + + align:start position:0% +in a 2d grid so that you can like I + + + align:start position:0% +in a 2d grid so that you can like I +guess feel like some shape and there's + + align:start position:0% +guess feel like some shape and there's + + + align:start position:0% +guess feel like some shape and there's +also um I saw this talk last week of + + align:start position:0% +also um I saw this talk last week of + + + align:start position:0% +also um I saw this talk last week of +Microsoft research um working on this + + align:start position:0% +Microsoft research um working on this + + + align:start position:0% +Microsoft research um working on this +like tongue controlling interface where + + align:start position:0% +like tongue controlling interface where + + + align:start position:0% +like tongue controlling interface where +you can use no seriously like they gave + + align:start position:0% +you can use no seriously like they gave + + + align:start position:0% +you can use no seriously like they gave +this to disabled people and put them in + + align:start position:0% +this to disabled people and put them in + + + align:start position:0% +this to disabled people and put them in +this wheelchair and they could use their + + align:start position:0% +this wheelchair and they could use their + + + align:start position:0% +this wheelchair and they could use their +tongue to control the wheelchair and + + align:start position:0% +tongue to control the wheelchair and + + + align:start position:0% +tongue to control the wheelchair and +it's almost like their mind control yes + + align:start position:0% +it's almost like their mind control yes + + + align:start position:0% +it's almost like their mind control yes +right it's + + align:start position:0% +right it's + + + align:start position:0% +right it's +uh I think they something that does it + + align:start position:0% +uh I think they something that does it + + + align:start position:0% +uh I think they something that does it +with scanning the activity in the brain + + align:start position:0% +with scanning the activity in the brain + + + align:start position:0% +with scanning the activity in the brain +so I saw on it a while um oh thetive + + align:start position:0% +so I saw on it a while um oh thetive + + + align:start position:0% +so I saw on it a while um oh thetive +device I actually tried it it's not + + align:start position:0% + + + + align:start position:0% + +that of left and right and + + align:start position:0% +that of left and right and + + + align:start position:0% +that of left and right and +they way I don't + + align:start position:0% + + + + align:start position:0% + +know I at a video game company and use + + align:start position:0% +know I at a video game company and use + + + align:start position:0% +know I at a video game company and use +that exact device to make a video and + + align:start position:0% +that exact device to make a video and + + + align:start position:0% +that exact device to make a video and +you have to train it except for it's + + align:start position:0% +you have to train it except for it's + + + align:start position:0% +you have to train it except for it's +sort of finicky because basically the + + align:start position:0% +sort of finicky because basically the + + + align:start position:0% +sort of finicky because basically the +way it works is like you have this + + align:start position:0% +way it works is like you have this + + + align:start position:0% +way it works is like you have this +training interface where um they tell + + align:start position:0% +training interface where um they tell + + + align:start position:0% +training interface where um they tell +you to like push or pull and like it + + align:start position:0% +you to like push or pull and like it + + + align:start position:0% +you to like push or pull and like it +Associates like your certain like + + align:start position:0% +Associates like your certain like + + + align:start position:0% +Associates like your certain like +thought patterns with like the push or + + align:start position:0% +thought patterns with like the push or + + + align:start position:0% +thought patterns with like the push or +with the pull but I don't know it's like + + align:start position:0% +with the pull but I don't know it's like + + + align:start position:0% +with the pull but I don't know it's like +maybe I just didn't practice it enough + + align:start position:0% +maybe I just didn't practice it enough + + + align:start position:0% +maybe I just didn't practice it enough +um it it's not that reliable so it's + + align:start position:0% +um it it's not that reliable so it's + + + align:start position:0% +um it it's not that reliable so it's +like for video game or for like toy + + align:start position:0% +like for video game or for like toy + + + align:start position:0% +like for video game or for like toy +applications it's okay but if you + + align:start position:0% +applications it's okay but if you + + + align:start position:0% +applications it's okay but if you +actually want to use that to like + + align:start position:0% +actually want to use that to like + + + align:start position:0% +actually want to use that to like +control I don't know like an evelon + + align:start position:0% +control I don't know like an evelon + + + align:start position:0% +control I don't know like an evelon +style giant robot + + align:start position:0% + + + + align:start position:0% + +like uh this is an old thing I don't + + align:start position:0% +like uh this is an old thing I don't + + + align:start position:0% +like uh this is an old thing I don't +know if there are any better ones yes + + align:start position:0% +know if there are any better ones yes + + + align:start position:0% +know if there are any better ones yes +uh the people with the tongue Gadget + + align:start position:0% +uh the people with the tongue Gadget + + + align:start position:0% +uh the people with the tongue Gadget +claim very good results I don't know + + align:start position:0% +claim very good results I don't know + + + align:start position:0% +claim very good results I don't know +what it's like to go around with that + + align:start position:0% +what it's like to go around with that + + + align:start position:0% +what it's like to go around with that +thing in your mouth + + align:start position:0% +thing in your mouth + + + align:start position:0% +thing in your mouth +but they made a wireless one it's like + + align:start position:0% +but they made a wireless one it's like + + + align:start position:0% +but they made a wireless one it's like +in the shape of Aer oh okay is is it + + align:start position:0% +in the shape of Aer oh okay is is it + + + align:start position:0% +in the shape of Aer oh okay is is it +anchored to the teeth or something uh + + align:start position:0% +anchored to the teeth or something uh + + + align:start position:0% +anchored to the teeth or something uh +it's basically like a retener with you + + align:start position:0% +it's basically like a retener with you + + + align:start position:0% +it's basically like a retener with you +know wires to hold it on your teeth and + + align:start position:0% +know wires to hold it on your teeth and + + + align:start position:0% +know wires to hold it on your teeth and +it sticks on the your mouth oh so you + + align:start position:0% +it sticks on the your mouth oh so you + + + align:start position:0% +it sticks on the your mouth oh so you +just that that doesn't sound so bad is + + align:start position:0% +just that that doesn't sound so bad is + + + align:start position:0% +just that that doesn't sound so bad is +it Wireless that would be yeah yeah um + + align:start position:0% +it Wireless that would be yeah yeah um + + + align:start position:0% +it Wireless that would be yeah yeah um +okay by tan from Microsoft research and + + align:start position:0% +okay by tan from Microsoft research and + + + align:start position:0% +okay by tan from Microsoft research and +he showed stuff about that this guy I + + align:start position:0% +he showed stuff about that this guy I + + + align:start position:0% +he showed stuff about that this guy I +think it's spelled right but I'm not + + align:start position:0% +think it's spelled right but I'm not + + + align:start position:0% +think it's spelled right but I'm not +sure + + align:start position:0% +sure + + + align:start position:0% +sure +um uh is a professor at Stanford and he + + align:start position:0% +um uh is a professor at Stanford and he + + + align:start position:0% +um uh is a professor at Stanford and he +made a uh an array of vibrators that go + + align:start position:0% +made a uh an array of vibrators that go + + + align:start position:0% +made a uh an array of vibrators that go +on your + + align:start position:0% +on your + + + align:start position:0% +on your +back and uh I put it on once uh it's 20 + + align:start position:0% +back and uh I put it on once uh it's 20 + + + align:start position:0% +back and uh I put it on once uh it's 20 +by 20 I + + align:start position:0% + + + + align:start position:0% + +think and they all work so it's uh + + align:start position:0% +think and they all work so it's uh + + + align:start position:0% +think and they all work so it's uh +that's better than the 8 by8 thing and I + + align:start position:0% +that's better than the 8 by8 thing and I + + + align:start position:0% +that's better than the 8 by8 thing and I +was able to recognize a + + align:start position:0% +was able to recognize a + + + align:start position:0% +was able to recognize a +telephone it's connected to a video + + align:start position:0% +telephone it's connected to a video + + + align:start position:0% +telephone it's connected to a video +camera and it's uh and it's just a pad + + align:start position:0% +camera and it's uh and it's just a pad + + + align:start position:0% +camera and it's uh and it's just a pad +on your back and if um you have a TV + + align:start position:0% +on your back and if um you have a TV + + + align:start position:0% +on your back and if um you have a TV +camera with the right kind of contrast + + align:start position:0% +camera with the right kind of contrast + + + align:start position:0% +camera with the right kind of contrast +and you can uh you can find the + + align:start position:0% +and you can uh you can find the + + + align:start position:0% +and you can uh you can find the +door and stuff like that it's easy and + + align:start position:0% +door and stuff like that it's easy and + + + align:start position:0% +door and stuff like that it's easy and +and I recognized a couple of objects I + + align:start position:0% +and I recognized a couple of objects I + + + align:start position:0% +and I recognized a couple of objects I +was only in it for about five minutes + + align:start position:0% +was only in it for about five minutes + + + align:start position:0% +was only in it for about five minutes +but uh the interesting thing is that uh + + align:start position:0% +but uh the interesting thing is that uh + + + align:start position:0% +but uh the interesting thing is that uh +it didn't take take any time + + align:start position:0% +it didn't take take any time + + + align:start position:0% +it didn't take take any time +to + + align:start position:0% +to + + + align:start position:0% +to +uh feel this in input as a shape I was + + align:start position:0% +uh feel this in input as a shape I was + + + align:start position:0% +uh feel this in input as a shape I was +pretty + + align:start position:0% + + + + align:start position:0% + +surprised um that was many years ago uh + + align:start position:0% +surprised um that was many years ago uh + + + align:start position:0% +surprised um that was many years ago uh +I don't + + align:start position:0% +I don't + + + align:start position:0% +I don't +know what's happened + + align:start position:0% + + + + align:start position:0% + +since uh there's reading devices for the + + align:start position:0% +since uh there's reading devices for the + + + align:start position:0% +since uh there's reading devices for the +blind that uh go on your finger so + + align:start position:0% +blind that uh go on your finger so + + + align:start position:0% +blind that uh go on your finger so +instead of Braille + + align:start position:0% +instead of Braille + + + align:start position:0% +instead of Braille +uh you go like this and it can make make + + align:start position:0% +uh you go like this and it can make make + + + align:start position:0% +uh you go like this and it can make make +a sound or it can make a vibration in + + align:start position:0% +a sound or it can make a vibration in + + + align:start position:0% +a sound or it can make a vibration in +your + + align:start position:0% +your + + + align:start position:0% +your +fingertip see the trouble with Braille + + align:start position:0% +fingertip see the trouble with Braille + + + align:start position:0% +fingertip see the trouble with Braille +is you have to have + + align:start position:0% +is you have to have + + + align:start position:0% +is you have to have +Braille but this + + align:start position:0% +Braille but this + + + align:start position:0% +Braille but this +device I can't remember who makes + + align:start position:0% +device I can't remember who makes + + + align:start position:0% +device I can't remember who makes +it uh you just put this little thimble + + align:start position:0% +it uh you just put this little thimble + + + align:start position:0% +it uh you just put this little thimble +on and it has tiny + + align:start position:0% +on and it has tiny + + + align:start position:0% +on and it has tiny +vibrators so that it's like Braille it + + align:start position:0% +vibrators so that it's like Braille it + + + align:start position:0% +vibrators so that it's like Braille it +makes and you can feel the letters go by + + align:start position:0% +makes and you can feel the letters go by + + + align:start position:0% +makes and you can feel the letters go by +as + + align:start position:0% +as + + + align:start position:0% +as +uh as you move your + + align:start position:0% +uh as you move your + + + align:start position:0% +uh as you move your +finger and I've forgotten the + + align:start position:0% +finger and I've forgotten the + + + align:start position:0% +finger and I've forgotten the +professor's name for this do that + + align:start position:0% +professor's name for this do that + + + align:start position:0% +professor's name for this do that +ringabell uh anyway only about 10% of + + align:start position:0% +ringabell uh anyway only about 10% of + + + align:start position:0% +ringabell uh anyway only about 10% of +blind people find uh it easy to learn to + + align:start position:0% +blind people find uh it easy to learn to + + + align:start position:0% +blind people find uh it easy to learn to +to read this way + + align:start position:0% +to read this way + + + align:start position:0% +to read this way +so it hasn't it's not widely in + + align:start position:0% +so it hasn't it's not widely in + + + align:start position:0% +so it hasn't it's not widely in +production + + align:start position:0% + + + + align:start position:0% + +but that's all beside the point I think + + align:start position:0% +but that's all beside the point I think + + + align:start position:0% +but that's all beside the point I think +at some + + align:start position:0% +at some + + + align:start position:0% +at some +point + + align:start position:0% +point + + + align:start position:0% +point +uh somebody's in some country will will + + align:start position:0% +uh somebody's in some country will will + + + align:start position:0% +uh somebody's in some country will will +uh want to try + + align:start position:0% +uh want to try + + + align:start position:0% +uh want to try +this uh direct brain connection thing + + align:start position:0% +this uh direct brain connection thing + + + align:start position:0% +this uh direct brain connection thing +might be great might be really good for + + align:start position:0% +might be great might be really good for + + + align:start position:0% +might be great might be really good for +an older person who's become + + align:start position:0% +an older person who's become + + + align:start position:0% +an older person who's become +blind + + align:start position:0% +blind + + + align:start position:0% +blind +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +a senior person who's lost Vision might + + align:start position:0% +a senior person who's lost Vision might + + + align:start position:0% +a senior person who's lost Vision might +not be able to soup up their hearing and + + align:start position:0% +not be able to soup up their hearing and + + + align:start position:0% +not be able to soup up their hearing and +and other senses well enough or or learn + + align:start position:0% +and other senses well enough or or learn + + + align:start position:0% +and other senses well enough or or learn +fast enough uh to get + + align:start position:0% +fast enough uh to get + + + align:start position:0% +fast enough uh to get +around uh so + + align:start position:0% + + + + align:start position:0% + +being if you're if you become blind deaf + + align:start position:0% +being if you're if you become blind deaf + + + align:start position:0% +being if you're if you become blind deaf +like Helen Keller when you're a few + + align:start position:0% +like Helen Keller when you're a few + + + align:start position:0% +like Helen Keller when you're a few +months old or was she three years old + + align:start position:0% +months old or was she three years old + + + align:start position:0% +months old or was she three years old +anybody + + align:start position:0% +anybody + + + align:start position:0% +anybody +remember oh but + + align:start position:0% +remember oh but + + + align:start position:0% +remember oh but +uh so she just adapted and became quite + + align:start position:0% +uh so she just adapted and became quite + + + align:start position:0% +uh so she just adapted and became quite +a good writer + + align:start position:0% +a good writer + + + align:start position:0% +a good writer +and + + align:start position:0% +and + + + align:start position:0% +and +uh I think when thinking about like + + align:start position:0% +uh I think when thinking about like + + + align:start position:0% +uh I think when thinking about like +augmenting human intelligence there are + + align:start position:0% +augmenting human intelligence there are + + + align:start position:0% +augmenting human intelligence there are +really like two big rounds um to to + + align:start position:0% +really like two big rounds um to to + + + align:start position:0% +really like two big rounds um to to +think about one realm is sort of like + + align:start position:0% +think about one realm is sort of like + + + align:start position:0% +think about one realm is sort of like +developing the external device that like + + align:start position:0% +developing the external device that like + + + align:start position:0% +developing the external device that like +does the things for you that retrieves + + align:start position:0% +does the things for you that retrieves + + + align:start position:0% +does the things for you that retrieves +information and then the other realm is + + align:start position:0% +information and then the other realm is + + + align:start position:0% +information and then the other realm is +like the interface between the external + + align:start position:0% +like the interface between the external + + + align:start position:0% +like the interface between the external +thing and the human being yes what's the + + align:start position:0% +thing and the human being yes what's the + + + align:start position:0% +thing and the human being yes what's the +representations and it'd be wonderful to + + align:start position:0% +representations and it'd be wonderful to + + + align:start position:0% +representations and it'd be wonderful to +have a a gadget with a bunch of brain + + align:start position:0% +have a a gadget with a bunch of brain + + + align:start position:0% +have a a gadget with a bunch of brain +electrodes so you could you could + + align:start position:0% +electrodes so you could you could + + + align:start position:0% +electrodes so you could you could +discover uh what kinds of symbols can + + align:start position:0% +discover uh what kinds of symbols can + + + align:start position:0% +discover uh what kinds of symbols can +people learn to + + align:start position:0% +people learn to + + + align:start position:0% +people learn to +distinguish and uh we'd probably learn + + align:start position:0% +distinguish and uh we'd probably learn + + + align:start position:0% +distinguish and uh we'd probably learn +more about the brain in a couple of + + align:start position:0% +more about the brain in a couple of + + + align:start position:0% +more about the brain in a couple of +years than in the previous + + align:start position:0% +years than in the previous + + + align:start position:0% +years than in the previous +Century uh because we could we could get + + align:start position:0% +Century uh because we could we could get + + + align:start position:0% +Century uh because we could we could get +some idea of representations to to + + align:start position:0% +some idea of representations to to + + + align:start position:0% +some idea of representations to to +people represent things as list struct + + align:start position:0% +people represent things as list struct + + + align:start position:0% +people represent things as list struct +or as Productions or uh computer science + + align:start position:0% +or as Productions or uh computer science + + + align:start position:0% +or as Productions or uh computer science +has come up with lots of ways to + + align:start position:0% +has come up with lots of ways to + + + align:start position:0% +has come up with lots of ways to +represent + + align:start position:0% +represent + + + align:start position:0% +represent +knowledge I've never met a + + align:start position:0% +knowledge I've never met a + + + align:start position:0% +knowledge I've never met a +neuroscientist who even knows what what + + align:start position:0% +neuroscientist who even knows what what + + + align:start position:0% +neuroscientist who even knows what what +the + + align:start position:0% +the + + + align:start position:0% +the +uh your smirk uh maybe there are some I + + align:start position:0% +uh your smirk uh maybe there are some I + + + align:start position:0% +uh your smirk uh maybe there are some I +haven't met I'm sure well there's me + + align:start position:0% +haven't met I'm sure well there's me + + + align:start position:0% +haven't met I'm sure well there's me +that's why I + + align:start position:0% +that's why I + + + align:start position:0% +that's why I +smirk uh + + align:start position:0% +smirk uh + + + align:start position:0% +smirk uh +but I've complained about this about + + align:start position:0% +but I've complained about this about + + + align:start position:0% +but I've complained about this about +four times already but uh the best + + align:start position:0% +four times already but uh the best + + + align:start position:0% +four times already but uh the best +example is to look at the review of the + + align:start position:0% +example is to look at the review of the + + + align:start position:0% +example is to look at the review of the +emotion machine on my on the Amazon uh + + align:start position:0% +emotion machine on my on the Amazon uh + + + align:start position:0% +emotion machine on my on the Amazon uh +book page for it course there's this + + align:start position:0% +book page for it course there's this + + + align:start position:0% +book page for it course there's this +neurologist who + + align:start position:0% +neurologist who + + + align:start position:0% +neurologist who +says he writes all about these Kines and + + align:start position:0% +says he writes all about these Kines and + + + align:start position:0% +says he writes all about these Kines and +and and penies and + + align:start position:0% +and and penies and + + + align:start position:0% +and and penies and +isomes and he has no evidence they + + align:start position:0% + + + + align:start position:0% + +exist and it's just so funny because I'm + + align:start position:0% +exist and it's just so funny because I'm + + + align:start position:0% +exist and it's just so funny because I'm +writing this book to help those here + + align:start position:0% +writing this book to help those here + + + align:start position:0% +writing this book to help those here +they're drowning in ignorance and I've + + align:start position:0% +they're drowning in ignorance and I've + + + align:start position:0% +they're drowning in ignorance and I've +just taught them this life raft and they + + align:start position:0% +just taught them this life raft and they + + + align:start position:0% +just taught them this life raft and they +say well uh he hasn't tested this life + + align:start position:0% +say well uh he hasn't tested this life + + + align:start position:0% +say well uh he hasn't tested this life +raft to see if + + align:start position:0% +raft to see if + + + align:start position:0% +raft to see if +it they don't like the idea of a + + align:start position:0% +it they don't like the idea of a + + + align:start position:0% +it they don't like the idea of a +suggestion if you haven't proved it it's + + align:start position:0% +suggestion if you haven't proved it it's + + + align:start position:0% +suggestion if you haven't proved it it's +a that is not the way to do + + align:start position:0% +a that is not the way to do + + + align:start position:0% +a that is not the way to do +science uh you have to make + + align:start position:0% +science uh you have to make + + + align:start position:0% +science uh you have to make +hypothesis and if you're neuroscientist + + align:start position:0% +hypothesis and if you're neuroscientist + + + align:start position:0% +hypothesis and if you're neuroscientist +you can't do that because it's not in + + align:start position:0% +you can't do that because it's not in + + + align:start position:0% +you can't do that because it's not in +your nature so you have to get them from + + align:start position:0% +your nature so you have to get them from + + + align:start position:0% +your nature so you have to get them from +someone else it's very + + align:start position:0% + + + + align:start position:0% + +simple how come there are no programming + + align:start position:0% +simple how come there are no programming + + + align:start position:0% +simple how come there are no programming +languages that have decent + + align:start position:0% +languages that have decent + + + align:start position:0% +languages that have decent +representations of + + align:start position:0% +representations of + + + align:start position:0% +representations of +anything I people tell me they use C++ + + align:start position:0% +anything I people tell me they use C++ + + + align:start position:0% +anything I people tell me they use C++ +whatever that + + align:start position:0% + + + + align:start position:0% + +is I think when wrote a book on how to + + align:start position:0% +is I think when wrote a book on how to + + + align:start position:0% +is I think when wrote a book on how to +program in that and I asked him do you + + align:start position:0% +program in that and I asked him do you + + + align:start position:0% +program in that and I asked him do you +actually know how to program in that + + align:start position:0% +actually know how to program in that + + + align:start position:0% +actually know how to program in that +language he said of course not but I + + align:start position:0% +language he said of course not but I + + + align:start position:0% +language he said of course not but I +know how to write books on how to + + align:start position:0% +know how to write books on how to + + + align:start position:0% +know how to write books on how to +program do you remember that it's a + + align:start position:0% +program do you remember that it's a + + + align:start position:0% +program do you remember that it's a +great learning experience you actually + + align:start position:0% +great learning experience you actually + + + align:start position:0% +great learning experience you actually +said something like + + align:start position:0% +said something like + + + align:start position:0% +said something like +that because you write the book and then + + align:start position:0% +that because you write the book and then + + + align:start position:0% +that because you write the book and then +you can get other people to put in the + + align:start position:0% +you can get other people to put in the + + + align:start position:0% +you can get other people to put in the +examples + + align:start position:0% +examples + + + align:start position:0% +examples +uh you should all read some of my I + + align:start position:0% +uh you should all read some of my I + + + align:start position:0% +uh you should all read some of my I +couldn't force myself to learn C without + + align:start position:0% +couldn't force myself to learn C without + + + align:start position:0% +couldn't force myself to learn C without +writing a book about it it was too + + align:start position:0% +writing a book about it it was too + + + align:start position:0% +writing a book about it it was too +boring that's + + align:start position:0% +boring that's + + + align:start position:0% +boring that's +right right um if you if you read my + + align:start position:0% +right right um if you if you read my + + + align:start position:0% +right right um if you if you read my +book on + + align:start position:0% +book on + + + align:start position:0% +book on +computation which is still actually + + align:start position:0% +computation which is still actually + + + align:start position:0% +computation which is still actually +current because it's about things that + + align:start position:0% +current because it's about things that + + + align:start position:0% +current because it's about things that +they don't teach + + align:start position:0% +they don't teach + + + align:start position:0% +they don't teach +much uh and uh the best thing about the + + align:start position:0% +much uh and uh the best thing about the + + + align:start position:0% +much uh and uh the best thing about the +book is that it's full of problems that + + align:start position:0% +book is that it's full of problems that + + + align:start position:0% +book is that it's full of problems that +you can actually solve and most but I + + align:start position:0% +you can actually solve and most but I + + + align:start position:0% +you can actually solve and most but I +wasn't good at making up problems so + + align:start position:0% +wasn't good at making up problems so + + + align:start position:0% +wasn't good at making up problems so +most of the problems there are U Were + + align:start position:0% +most of the problems there are U Were + + + align:start position:0% +most of the problems there are U Were +Made Up by a gradu young graduate + + align:start position:0% +Made Up by a gradu young graduate + + + align:start position:0% +Made Up by a gradu young graduate +student named Manuel + + align:start position:0% +student named Manuel + + + align:start position:0% +student named Manuel +Bloom uh and I don't think I gave him + + align:start position:0% +Bloom uh and I don't think I gave him + + + align:start position:0% +Bloom uh and I don't think I gave him +enough credit in the book I just took it + + align:start position:0% +enough credit in the book I just took it + + + align:start position:0% +enough credit in the book I just took it +for granted that people are good at + + align:start position:0% +for granted that people are good at + + + align:start position:0% +for granted that people are good at +making up problems and I didn't realize + + align:start position:0% +making up problems and I didn't realize + + + align:start position:0% +making up problems and I didn't realize +how rare this + + align:start position:0% +how rare this + + + align:start position:0% +how rare this +was he now has the property + + align:start position:0% +was he now has the property + + + align:start position:0% +was he now has the property +that Manuel and his wife Lenor and his + + align:start position:0% +that Manuel and his wife Lenor and his + + + align:start position:0% +that Manuel and his wife Lenor and his +son whose name I forgot are all + + align:start position:0% +son whose name I forgot are all + + + align:start position:0% +son whose name I forgot are all +professors at + + align:start position:0% +professors at + + + align:start position:0% +professors at +CMU so + + align:start position:0% +CMU so + + + align:start position:0% +CMU so +that's yes is do you know any are there + + align:start position:0% +that's yes is do you know any are there + + + align:start position:0% +that's yes is do you know any are there +any other such + + align:start position:0% + + + + align:start position:0% + +families but uh + + align:start position:0% + + + + align:start position:0% + +and as far as I can tell Winston's book + + align:start position:0% +and as far as I can tell Winston's book + + + align:start position:0% +and as far as I can tell Winston's book +has been substantially replaced by this + + align:start position:0% +has been substantially replaced by this + + + align:start position:0% +has been substantially replaced by this +noran what's his name but there's right + + align:start position:0% +noran what's his name but there's right + + + align:start position:0% +noran what's his name but there's right +but there's almost no ideas about AI in + + align:start position:0% +but there's almost no ideas about AI in + + + align:start position:0% +but there's almost no ideas about AI in +in that book so we have a text + + align:start position:0% +in that book so we have a text + + + align:start position:0% +in that book so we have a text +book that is not helping the field + + align:start position:0% +book that is not helping the field + + + align:start position:0% +book that is not helping the field +progress very much because it's giving a + + align:start position:0% +progress very much because it's giving a + + + align:start position:0% +progress very much because it's giving a +lot of details about methods that I do + + align:start position:0% +lot of details about methods that I do + + + align:start position:0% +lot of details about methods that I do +well you know like lots of stuff about + + align:start position:0% +well you know like lots of stuff about + + + align:start position:0% +well you know like lots of stuff about +probabilistic + + align:start position:0% +probabilistic + + + align:start position:0% +probabilistic +learning which is very nice but I don't + + align:start position:0% +learning which is very nice but I don't + + + align:start position:0% +learning which is very nice but I don't +think it has much + + align:start position:0% + + + + align:start position:0% + +future so if you meet anybody who's + + align:start position:0% +future so if you meet anybody who's + + + align:start position:0% +future so if you meet anybody who's +interested in AI get them to read Pat's + + align:start position:0% +interested in AI get them to read Pat's + + + align:start position:0% +interested in AI get them to read Pat's +book yes so what happened like why did + + align:start position:0% +book yes so what happened like why did + + + align:start position:0% +book yes so what happened like why did +MIT change like so much why like so many + + align:start position:0% +MIT change like so much why like so many + + + align:start position:0% +MIT change like so much why like so many +machine learning people + + align:start position:0% +machine learning people + + + align:start position:0% +machine learning people +well there was a very strange phenomenon + + align:start position:0% +well there was a very strange phenomenon + + + align:start position:0% +well there was a very strange phenomenon +called Rodney + + align:start position:0% +called Rodney + + + align:start position:0% +called Rodney +Brooks who + + align:start position:0% +Brooks who + + + align:start position:0% +Brooks who +uh somehow got a worldwide + + align:start position:0% +uh somehow got a worldwide + + + align:start position:0% +uh somehow got a worldwide +reputation for + + align:start position:0% +reputation for + + + align:start position:0% +reputation for +inventing + + align:start position:0% +inventing + + + align:start position:0% +inventing +uh what was it called subsumption + + align:start position:0% +uh what was it called subsumption + + + align:start position:0% +uh what was it called subsumption +subsumption subsumption was + + align:start position:0% +subsumption subsumption was + + + align:start position:0% +subsumption subsumption was +a formulation related to what the first + + align:start position:0% +a formulation related to what the first + + + align:start position:0% +a formulation related to what the first +computer people called priority + + align:start position:0% +computer people called priority + + + align:start position:0% +computer people called priority +interrupt so uh instead of having + + align:start position:0% +interrupt so uh instead of having + + + align:start position:0% +interrupt so uh instead of having +highlevel programming + + align:start position:0% +highlevel programming + + + align:start position:0% +highlevel programming +languages Brook pointed out that if you + + align:start position:0% +languages Brook pointed out that if you + + + align:start position:0% +languages Brook pointed out that if you +just have a bunch of statements and give + + align:start position:0% +just have a bunch of statements and give + + + align:start position:0% +just have a bunch of statements and give +them + + align:start position:0% +them + + + align:start position:0% +them +priorities uh and then take the one that + + align:start position:0% +priorities uh and then take the one that + + + align:start position:0% +priorities uh and then take the one that +uh you take all the statements that + + align:start position:0% +uh you take all the statements that + + + align:start position:0% +uh you take all the statements that +apply to a situation and take the one + + align:start position:0% +apply to a situation and take the one + + + align:start position:0% +apply to a situation and take the one +with the highest priority and do that uh + + align:start position:0% +with the highest priority and do that uh + + + align:start position:0% +with the highest priority and do that uh +then you can write a PhD thesis + + align:start position:0% +then you can write a PhD thesis + + + align:start position:0% +then you can write a PhD thesis +uh and make a movie of an experiment in + + align:start position:0% +uh and make a movie of an experiment in + + + align:start position:0% +uh and make a movie of an experiment in +which a robot actually found a coke + + align:start position:0% +which a robot actually found a coke + + + align:start position:0% +which a robot actually found a coke +bottle now the fact that the first 40 + + align:start position:0% +bottle now the fact that the first 40 + + + align:start position:0% +bottle now the fact that the first 40 +times it didn't find the coke + + align:start position:0% +times it didn't find the coke + + + align:start position:0% +times it didn't find the coke +bottle uh because when it got near the + + align:start position:0% +bottle uh because when it got near the + + + align:start position:0% +bottle uh because when it got near the +table it couldn't see it anymore and it + + align:start position:0% +table it couldn't see it anymore and it + + + align:start position:0% +table it couldn't see it anymore and it +had no + + align:start position:0% +had no + + + align:start position:0% +had no +memory is uh was ignored by the + + align:start position:0% +memory is uh was ignored by the + + + align:start position:0% +memory is uh was ignored by the +worldwide + + align:start position:0% +worldwide + + + align:start position:0% +worldwide +community and so uh + + align:start position:0% +community and so uh + + + align:start position:0% +community and so uh +some of Rodney Brook's ideas swept the + + align:start position:0% +some of Rodney Brook's ideas swept the + + + align:start position:0% +some of Rodney Brook's ideas swept the +entire world stopped research in + + align:start position:0% +entire world stopped research in + + + align:start position:0% +entire world stopped research in +Japan + + align:start position:0% +Japan + + + align:start position:0% +Japan +uh because they all turned toward saying + + align:start position:0% +uh because they all turned toward saying + + + align:start position:0% +uh because they all turned toward saying +if you just observe the environment + + align:start position:0% +if you just observe the environment + + + align:start position:0% +if you just observe the environment +properly you can solve a lot of problems + + align:start position:0% +properly you can solve a lot of problems + + + align:start position:0% +properly you can solve a lot of problems +without making + + align:start position:0% +without making + + + align:start position:0% +without making +plans uh and he won + + align:start position:0% +plans uh and he won + + + align:start position:0% +plans uh and he won +the top prize that the uh AI + + align:start position:0% +the top prize that the uh AI + + + align:start position:0% +the top prize that the uh AI +Society gave out it's a complete mystery + + align:start position:0% +Society gave out it's a complete mystery + + + align:start position:0% +Society gave out it's a complete mystery +to me here is four or five really bad + + align:start position:0% +to me here is four or five really bad + + + align:start position:0% +to me here is four or five really bad +ideas that swept the world and replaced + + align:start position:0% +ideas that swept the world and replaced + + + align:start position:0% +ideas that swept the world and replaced +almost all other AI research for a + + align:start position:0% +almost all other AI research for a + + + align:start position:0% +almost all other AI research for a +decade or two + + align:start position:0% +decade or two + + + align:start position:0% +decade or two +wonderful uh that's why there are no + + align:start position:0% +wonderful uh that's why there are no + + + align:start position:0% +wonderful uh that's why there are no +robots that can go into the + + align:start position:0% +robots that can go into the + + + align:start position:0% +robots that can go into the +reactors in uh Japan and fix + + align:start position:0% +reactors in uh Japan and fix + + + align:start position:0% +reactors in uh Japan and fix +things because all the robots we have + + align:start position:0% +things because all the robots we have + + + align:start position:0% +things because all the robots we have +only react + + align:start position:0% +only react + + + align:start position:0% +only react +to never mind + + align:start position:0% +to never mind + + + align:start position:0% +to never mind +yeah uh so how do you see we changing + + align:start position:0% +yeah uh so how do you see we changing + + + align:start position:0% +yeah uh so how do you see we changing +that from now now we have a problem that + + align:start position:0% +that from now now we have a problem that + + + align:start position:0% +that from now now we have a problem that +most of + + align:start position:0% +most of + + + align:start position:0% +most of +the maybe most of the stuff in computer + + align:start position:0% +the maybe most of the stuff in computer + + + align:start position:0% +the maybe most of the stuff in computer +science or more people + + align:start position:0% +science or more people + + + align:start position:0% +science or more people +AI real estate I don't know inference or + + align:start position:0% +AI real estate I don't know inference or + + + align:start position:0% +AI real estate I don't know inference or +I don't know some kind of + + align:start position:0% +I don't know some kind of + + + align:start position:0% +I don't know some kind of +uh supervised learning or supervised + + align:start position:0% +uh supervised learning or supervised + + + align:start position:0% +uh supervised learning or supervised +learning and that makes a lot of money I + + align:start position:0% +learning and that makes a lot of money I + + + align:start position:0% +learning and that makes a lot of money I +mean if you well that's the problem + + align:start position:0% +mean if you well that's the problem + + + align:start position:0% +mean if you well that's the problem +uh the best way to make money is to + + align:start position:0% +uh the best way to make money is to + + + align:start position:0% +uh the best way to make money is to +steal it so why doesn't everybody just + + align:start position:0% +steal it so why doesn't everybody just + + + align:start position:0% +steal it so why doesn't everybody just +turn and go down this corner and mug + + align:start position:0% + + + + align:start position:0% + +someone I mean they're thinking long ter + + align:start position:0% +someone I mean they're thinking long ter + + + align:start position:0% +someone I mean they're thinking long ter +yeah there's a real problem here because + + align:start position:0% +yeah there's a real problem here because + + + align:start position:0% +yeah there's a real problem here because +you can mug a lot of people in parallel + + align:start position:0% +you can mug a lot of people in parallel + + + align:start position:0% +you can mug a lot of people in parallel +using uh + + align:start position:0% +using uh + + + align:start position:0% +using uh +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +that's + + align:start position:0% + + + + align:start position:0% + +really you got + + align:start position:0% +really you got + + + align:start position:0% +really you got +it and isn't there any like smart other + + align:start position:0% +it and isn't there any like smart other + + + align:start position:0% +it and isn't there any like smart other +smart professors + + align:start position:0% +smart professors + + + align:start position:0% +smart professors +that like what can they see that why + + align:start position:0% +that like what can they see that why + + + align:start position:0% +that like what can they see that why +they see that it beats me I + + align:start position:0% +they see that it beats me I + + + align:start position:0% +they see that it beats me I +I'd like to hear some theories of + + align:start position:0% +I'd like to hear some theories of + + + align:start position:0% +I'd like to hear some theories of +why + + align:start position:0% +why + + + align:start position:0% +why +uh why the textbook by Russell and + + align:start position:0% +uh why the textbook by Russell and + + + align:start position:0% +uh why the textbook by Russell and +Norwood doesn't mention the Society of + + align:start position:0% +Norwood doesn't mention the Society of + + + align:start position:0% +Norwood doesn't mention the Society of +Mind theories for example I mean they've + + align:start position:0% +Mind theories for example I mean they've + + + align:start position:0% +Mind theories for example I mean they've +been out there for 30 + + align:start position:0% +been out there for 30 + + + align:start position:0% +been out there for 30 +years so there's + + align:start position:0% +years so there's + + + align:start position:0% +years so there's +something I don't know what what the + + align:start position:0% +something I don't know what what the + + + align:start position:0% +something I don't know what what the +problem is but 250,000 people are taking + + align:start position:0% +problem is but 250,000 people are taking + + + align:start position:0% +problem is but 250,000 people are taking +that course well so that things are + + align:start position:0% +that course well so that things are + + + align:start position:0% +that course well so that things are +going to get worse or better worse + + align:start position:0% + + + + align:start position:0% + +has anybody watched some of this course + + align:start position:0% +has anybody watched some of this course + + + align:start position:0% +has anybody watched some of this course +has it started yet oh it's Sil okay has + + align:start position:0% +has it started yet oh it's Sil okay has + + + align:start position:0% +has it started yet oh it's Sil okay has +it have any of you + + align:start position:0% +it have any of you + + + align:start position:0% +it have any of you +looked no one here + + align:start position:0% + + + + align:start position:0% + +I couldn't hear I think have moreal we + + align:start position:0% +I couldn't hear I think have moreal we + + + align:start position:0% +I couldn't hear I think have moreal we +weren't already taking classes here most + + align:start position:0% +weren't already taking classes here most + + + align:start position:0% +weren't already taking classes here most +people I know taking + + align:start position:0% +people I know taking + + + align:start position:0% +people I know taking +that working industry + + align:start position:0% +that working industry + + + align:start position:0% +that working industry +or + + align:start position:0% + + + + align:start position:0% + +uhhuh it it it seems to me that for + + align:start position:0% +uhhuh it it it seems to me that for + + + align:start position:0% +uhhuh it it it seems to me that for +example machine learning when people + + align:start position:0% +example machine learning when people + + + align:start position:0% +example machine learning when people +take machine learning they think they + + align:start position:0% +take machine learning they think they + + + align:start position:0% +take machine learning they think they +are very smart because they can do + + align:start position:0% +are very smart because they can do + + + align:start position:0% +are very smart because they can do +calculations with like a lot of symbols + + align:start position:0% +calculations with like a lot of symbols + + + align:start position:0% +calculations with like a lot of symbols +and they think oh I'm such a genius like + + align:start position:0% +and they think oh I'm such a genius like + + + align:start position:0% +and they think oh I'm such a genius like +I'm not saying that I'm smart but like + + align:start position:0% +I'm not saying that I'm smart but like + + + align:start position:0% +I'm not saying that I'm smart but like +it seems to me that dealing with + + align:start position:0% +it seems to me that dealing with + + + align:start position:0% +it seems to me that dealing with +symbols make people think that they are + + align:start position:0% +symbols make people think that they are + + + align:start position:0% +symbols make people think that they are +very smart and that makes the situation + + align:start position:0% +very smart and that makes the situation + + + align:start position:0% +very smart and that makes the situation +even worse because you have maybe people + + align:start position:0% +even worse because you have maybe people + + + align:start position:0% +even worse because you have maybe people +that could + + align:start position:0% +that could + + + align:start position:0% +that could +solve like this problem and they are oh + + align:start position:0% +solve like this problem and they are oh + + + align:start position:0% +solve like this problem and they are oh +I can do like a lot of calculation there + + align:start position:0% +I can do like a lot of calculation there + + + align:start position:0% +I can do like a lot of calculation there +the there are these really hard formulas + + align:start position:0% +the there are these really hard formulas + + + align:start position:0% +the there are these really hard formulas +that only I know + + align:start position:0% +that only I know + + + align:start position:0% +that only I know +and well + + align:start position:0% +and well + + + align:start position:0% +and well +I like it seems that theory of symbols + + align:start position:0% +I like it seems that theory of symbols + + + align:start position:0% +I like it seems that theory of symbols +is like more complex and harder and + + align:start position:0% +is like more complex and harder and + + + align:start position:0% +is like more complex and harder and +people tend to stick to MH theories that + + align:start position:0% +people tend to stick to MH theories that + + + align:start position:0% +people tend to stick to MH theories that +have symbols and formulas + + align:start position:0% +have symbols and formulas + + + align:start position:0% +have symbols and formulas +and I guess so but it somehow it doesn't + + align:start position:0% +and I guess so but it somehow it doesn't + + + align:start position:0% +and I guess so but it somehow it doesn't +to me mathematics is really hard and + + align:start position:0% +to me mathematics is really hard and + + + align:start position:0% +to me mathematics is really hard and +symbols are easy it's sort of + + align:start position:0% +symbols are easy it's sort of + + + align:start position:0% +symbols are easy it's sort of +funny yeah but there's still symbols + + align:start position:0% + + + + align:start position:0% + +yeah well + + align:start position:0% +yeah well + + + align:start position:0% +yeah well +does the machine course ever + + align:start position:0% +does the machine course ever + + + align:start position:0% +does the machine course ever +mention uh like Pat + + align:start position:0% +mention uh like Pat + + + align:start position:0% +mention uh like Pat +Winston's it's all about + + align:start position:0% +Winston's it's all about + + + align:start position:0% +Winston's it's all about +techniques machine + + align:start position:0% +techniques machine + + + align:start position:0% +techniques machine +learning + + align:start position:0% +learning + + + align:start position:0% +learning +yes + + align:start position:0% +yes + + + align:start position:0% +yes +because what Winston does is he looks at + + align:start position:0% +because what Winston does is he looks at + + + align:start position:0% +because what Winston does is he looks at +the differences between things and gets + + align:start position:0% +the differences between things and gets + + + align:start position:0% +the differences between things and gets +rid of them and you can think of it as a + + align:start position:0% +rid of them and you can think of it as a + + + align:start position:0% +rid of them and you can think of it as a +sort of symbolic + + align:start position:0% +sort of symbolic + + + align:start position:0% +sort of symbolic +Servo but there are a lot of very simple + + align:start position:0% +Servo but there are a lot of very simple + + + align:start position:0% +Servo but there are a lot of very simple +Common Sense sensical operations in the + + align:start position:0% +Common Sense sensical operations in the + + + align:start position:0% +Common Sense sensical operations in the +methods that he describes but none of + + align:start position:0% +methods that he describes but none of + + + align:start position:0% +methods that he describes but none of +them are easy to express as + + align:start position:0% +them are easy to express as + + + align:start position:0% +them are easy to express as +equations and maybe + + align:start position:0% + + + + align:start position:0% + +that's maybe programming isn't technical + + align:start position:0% +that's maybe programming isn't technical + + + align:start position:0% +that's maybe programming isn't technical +enough and you need to dress things up + + align:start position:0% +enough and you need to dress things up + + + align:start position:0% +enough and you need to dress things up +in in uh algebra to make I should redo + + align:start position:0% +in in uh algebra to make I should redo + + + align:start position:0% +in in uh algebra to make I should redo +that pces as an energy minimization + + align:start position:0% +that pces as an energy minimization + + + align:start position:0% +that pces as an energy minimization +principle or something oh that's cute + + align:start position:0% +principle or something oh that's cute + + + align:start position:0% +principle or something oh that's cute +yes getting closer to the goal that's + + align:start position:0% +yes getting closer to the goal that's + + + align:start position:0% +yes getting closer to the goal that's +all it + + align:start position:0% + + + + align:start position:0% + +is I think I mentioned the new and Simon + + align:start position:0% +is I think I mentioned the new and Simon + + + align:start position:0% +is I think I mentioned the new and Simon +had this great idea of of uh getting + + align:start position:0% +had this great idea of of uh getting + + + align:start position:0% +had this great idea of of uh getting +closer to the goal and they gave up with + + align:start position:0% +closer to the goal and they gave up with + + + align:start position:0% +closer to the goal and they gave up with +when they couldn't solve the missionary + + align:start position:0% +when they couldn't solve the missionary + + + align:start position:0% +when they couldn't solve the missionary +and cannibals problem because uh because + + align:start position:0% +and cannibals problem because uh because + + + align:start position:0% +and cannibals problem because uh because +there's a step where you have to take + + align:start position:0% +there's a step where you have to take + + + align:start position:0% +there's a step where you have to take +three people back in the + + align:start position:0% +three people back in the + + + align:start position:0% +three people back in the +boat and their program uh refused to do + + align:start position:0% +boat and their program uh refused to do + + + align:start position:0% +boat and their program uh refused to do +that because it wasn't getting them + + align:start position:0% +that because it wasn't getting them + + + align:start position:0% +that because it wasn't getting them +closer to the goal and the funny part is + + align:start position:0% +closer to the goal and the funny part is + + + align:start position:0% +closer to the goal and the funny part is +that if + + align:start position:0% +that if + + + align:start position:0% +that if +you if you used pairs of operations as + + align:start position:0% +you if you used pairs of operations as + + + align:start position:0% +you if you used pairs of operations as +the unit then then their method would + + align:start position:0% +the unit then then their method would + + + align:start position:0% +the unit then then their method would +work + + align:start position:0% + + + + align:start position:0% + +but nice question is why people how do + + align:start position:0% +but nice question is why people how do + + + align:start position:0% +but nice question is why people how do +people make a very beautiful Theory and + + align:start position:0% +people make a very beautiful Theory and + + + align:start position:0% +people make a very beautiful Theory and +then + + align:start position:0% +then + + + align:start position:0% +then +uh not take the next step and someone + + align:start position:0% +uh not take the next step and someone + + + align:start position:0% +uh not take the next step and someone +else does it n years later + + align:start position:0% +else does it n years later + + + align:start position:0% +else does it n years later +so I + + align:start position:0% +so I + + + align:start position:0% +so I +guess it always happens + + align:start position:0% +guess it always happens + + + align:start position:0% +guess it always happens +yes I just go and say I think machine + + align:start position:0% +yes I just go and say I think machine + + + align:start position:0% +yes I just go and say I think machine +learning is incredibly useful and we + + align:start position:0% +learning is incredibly useful and we + + + align:start position:0% +learning is incredibly useful and we +should discredit it because it really + + align:start position:0% +should discredit it because it really + + + align:start position:0% +should discredit it because it really +isn't Ai and I think a lot of the + + align:start position:0% +isn't Ai and I think a lot of the + + + align:start position:0% +isn't Ai and I think a lot of the +problems between machine learning people + + align:start position:0% +problems between machine learning people + + + align:start position:0% +problems between machine learning people +and AI people is that they're trying to + + align:start position:0% +and AI people is that they're trying to + + + align:start position:0% +and AI people is that they're trying to +do different things and they just have + + align:start position:0% +do different things and they just have + + + align:start position:0% +do different things and they just have +share this + + align:start position:0% +share this + + + align:start position:0% +share this +um and see different different important + + align:start position:0% +um and see different different important + + + align:start position:0% +um and see different different important +problems because well it's not they're + + align:start position:0% +problems because well it's not they're + + + align:start position:0% +problems because well it's not they're +not doing different things one is doing + + align:start position:0% +not doing different things one is doing + + + align:start position:0% +not doing different things one is doing +a subset of the other yes + + align:start position:0% +a subset of the other yes + + + align:start position:0% +a subset of the other yes +I the main problems intelligence and + + align:start position:0% +I the main problems intelligence and + + + align:start position:0% +I the main problems intelligence and +cognition but they are making a lot of + + align:start position:0% +cognition but they are making a lot of + + + align:start position:0% +cognition but they are making a lot of +good progress in solving certain types + + align:start position:0% +good progress in solving certain types + + + align:start position:0% +good progress in solving certain types +of really hard problems and this can be + + align:start position:0% +of really hard problems and this can be + + + align:start position:0% +of really hard problems and this can be +really useful because a lot of these are + + align:start position:0% +really useful because a lot of these are + + + align:start position:0% +really useful because a lot of these are +problems that people aren't able to + + align:start position:0% +problems that people aren't able to + + + align:start position:0% +problems that people aren't able to +solve themselves and aren't good at um + + align:start position:0% + + + + align:start position:0% + +is the science one at a time yeah + + align:start position:0% +is the science one at a time yeah + + + align:start position:0% +is the science one at a time yeah +sorry uh you could say that about + + align:start position:0% +sorry uh you could say that about + + + align:start position:0% +sorry uh you could say that about +anything + + align:start position:0% +anything + + + align:start position:0% +anything +though + + align:start position:0% +though + + + align:start position:0% +though +surely uh what's really important is not + + align:start position:0% +surely uh what's really important is not + + + align:start position:0% +surely uh what's really important is not +solving all sorts of useful things but + + align:start position:0% +solving all sorts of useful things but + + + align:start position:0% +solving all sorts of useful things but +getting to a higher level where you can + + align:start position:0% +getting to a higher level where you can + + + align:start position:0% +getting to a higher level where you can +solve things that no one else can + + align:start position:0% +solve things that no one else can + + + align:start position:0% +solve things that no one else can +solve what you mean important for what + + align:start position:0% +solve what you mean important for what + + + align:start position:0% +solve what you mean important for what +important for the advancement of science + + align:start position:0% +important for the advancement of science + + + align:start position:0% +important for the advancement of science +yes important for like miscellaneous + + align:start position:0% +yes important for like miscellaneous + + + align:start position:0% +yes important for like miscellaneous +applications that are useful + + align:start position:0% +applications that are useful + + + align:start position:0% +applications that are useful +people well in the long run you're dead + + align:start position:0% +people well in the long run you're dead + + + align:start position:0% +people well in the long run you're dead +so uh things like say that everything + + align:start position:0% +so uh things like say that everything + + + align:start position:0% +so uh things like say that everything +that doesn't just Advanced science is + + align:start position:0% +that doesn't just Advanced science is + + + align:start position:0% +that doesn't just Advanced science is +completely useless just crazy I don't no + + align:start position:0% +completely useless just crazy I don't no + + + align:start position:0% +completely useless just crazy I don't no +I'm saying science science has + + align:start position:0% +I'm saying science science has + + + align:start position:0% +I'm saying science science has +disappeared because the Dark Ages so + + align:start position:0% +disappeared because the Dark Ages so + + + align:start position:0% +disappeared because the Dark Ages so +it's interesting but if you say it's + + align:start position:0% +it's interesting but if you say it's + + + align:start position:0% +it's interesting but if you say it's +just advancing + + align:start position:0% +just advancing + + + align:start position:0% +just advancing +science uh yes I take the position that + + align:start position:0% +science uh yes I take the position that + + + align:start position:0% +science uh yes I take the position that +we should spend a fraction of our uh + + align:start position:0% +we should spend a fraction of our uh + + + align:start position:0% +we should spend a fraction of our uh +World Resources on long-term + + align:start position:0% +World Resources on long-term + + + align:start position:0% +World Resources on long-term +things and it's no excuse and and no one + + align:start position:0% +things and it's no excuse and and no one + + + align:start position:0% +things and it's no excuse and and no one +should say let's spend all our resources + + align:start position:0% +should say let's spend all our resources + + + align:start position:0% +should say let's spend all our resources +on immediate useful moneymaking labor + + align:start position:0% +on immediate useful moneymaking labor + + + align:start position:0% +on immediate useful moneymaking labor +saving processes I'm not saying that I + + align:start position:0% +saving processes I'm not saying that I + + + align:start position:0% +saving processes I'm not saying that I +think we should spend quite a bit of + + align:start position:0% +think we should spend quite a bit of + + + align:start position:0% +think we should spend quite a bit of +money on science but I'm saying it + + align:start position:0% +money on science but I'm saying it + + + align:start position:0% +money on science but I'm saying it +doesn't mean that anything that's not + + align:start position:0% +doesn't mean that anything that's not + + + align:start position:0% +doesn't mean that anything that's not +science is yeah but if you look at AI no + + align:start position:0% +science is yeah but if you look at AI no + + + align:start position:0% +science is yeah but if you look at AI no +money I only know about 10 people in the + + align:start position:0% +money I only know about 10 people in the + + + align:start position:0% +money I only know about 10 people in the +entire country who are thinking about + + align:start position:0% +entire country who are thinking about + + + align:start position:0% +entire country who are thinking about +hard problems in AI so it is it's not + + align:start position:0% +hard problems in AI so it is it's not + + + align:start position:0% +hard problems in AI so it is it's not +just a mild complaint there's some kind + + align:start position:0% +just a mild complaint there's some kind + + + align:start position:0% +just a mild complaint there's some kind +of + + align:start position:0% +of + + + align:start position:0% +of +pathology there's no support I don't + + align:start position:0% +pathology there's no support I don't + + + align:start position:0% +pathology there's no support I don't +think anybody's denying that machine + + align:start position:0% +think anybody's denying that machine + + + align:start position:0% +think anybody's denying that machine +learning is useful it's just the problem + + align:start position:0% +learning is useful it's just the problem + + + align:start position:0% +learning is useful it's just the problem +is that it seems like the obsession with + + align:start position:0% +is that it seems like the obsession with + + + align:start position:0% +is that it seems like the obsession with +machine learning is sort of like + + align:start position:0% +machine learning is sort of like + + + align:start position:0% +machine learning is sort of like +overtaking anyone like trying to make + + align:start position:0% +overtaking anyone like trying to make + + + align:start position:0% +overtaking anyone like trying to make +progress in AI so so it's like okay in + + align:start position:0% +progress in AI so so it's like okay in + + + align:start position:0% +progress in AI so so it's like okay in +the ideal world it's like they're the + + align:start position:0% +the ideal world it's like they're the + + + align:start position:0% +the ideal world it's like they're the +people who work on machine learning but + + align:start position:0% +people who work on machine learning but + + + align:start position:0% +people who work on machine learning but +then they're also the people who are + + align:start position:0% +then they're also the people who are + + + align:start position:0% +then they're also the people who are +solving the big AI problems but it seems + + align:start position:0% +solving the big AI problems but it seems + + + align:start position:0% +solving the big AI problems but it seems +like in the current world like so many + + align:start position:0% +like in the current world like so many + + + align:start position:0% +like in the current world like so many +people are doing machine learning that + + align:start position:0% +people are doing machine learning that + + + align:start position:0% +people are doing machine learning that +like and there's so many resources for + + align:start position:0% +like and there's so many resources for + + + align:start position:0% +like and there's so many resources for +it such that there's like not enough for + + align:start position:0% +it such that there's like not enough for + + + align:start position:0% +it such that there's like not enough for +people who are doing + + align:start position:0% +people who are doing + + + align:start position:0% +people who are doing +AI yeah well the complaint my complaint + + align:start position:0% +AI yeah well the complaint my complaint + + + align:start position:0% +AI yeah well the complaint my complaint +is that there's almost no one doing + + align:start position:0% +is that there's almost no one doing + + + align:start position:0% +is that there's almost no one doing +AI it's very peculiar so uh what is it + + align:start position:0% +AI it's very peculiar so uh what is it + + + align:start position:0% +AI it's very peculiar so uh what is it +about + + align:start position:0% +about + + + align:start position:0% +about +the uh current + + align:start position:0% +the uh current + + + align:start position:0% +the uh current +culture of science and technology that + + align:start position:0% +culture of science and technology that + + + align:start position:0% +culture of science and technology that +that causes this to + + align:start position:0% +that causes this to + + + align:start position:0% +that causes this to +happen a great example would be uh + + align:start position:0% +happen a great example would be uh + + + align:start position:0% +happen a great example would be uh +what's the gross product of what's the + + align:start position:0% +what's the gross product of what's the + + + align:start position:0% +what's the gross product of what's the +income of + + align:start position:0% +income of + + + align:start position:0% +income of +IBM it's big company how come they're + + align:start position:0% +IBM it's big company how come they're + + + align:start position:0% +IBM it's big company how come they're +doing that funny thing I keep forgetting + + align:start position:0% +doing that funny thing I keep forgetting + + + align:start position:0% +doing that funny thing I keep forgetting +how come they're doing + + align:start position:0% +how come they're doing + + + align:start position:0% +how come they're doing +Watson isn't that because it's cheaper + + align:start position:0% +Watson isn't that because it's cheaper + + + align:start position:0% +Watson isn't that because it's cheaper +than Super Bowl has + + align:start position:0% + + + + align:start position:0% + +they're getting kid they got a lot more + + align:start position:0% +they're getting kid they got a lot more + + + align:start position:0% +they're getting kid they got a lot more +publicity out of it than they would have + + align:start position:0% +publicity out of it than they would have + + + align:start position:0% +publicity out of it than they would have +gotten if a lot Super Bowl + + align:start position:0% +gotten if a lot Super Bowl + + + align:start position:0% +gotten if a lot Super Bowl +mhm I guess + + align:start position:0% + + + + align:start position:0% + +so but it's a serious company it fired + + align:start position:0% +so but it's a serious company it fired + + + align:start position:0% +so but it's a serious company it fired +its real AI + + align:start position:0% +its real AI + + + align:start position:0% +its real AI +group and + + align:start position:0% +group and + + + align:start position:0% +group and +what maybe properly question is um + + align:start position:0% +what maybe properly question is um + + + align:start position:0% +what maybe properly question is um +perhaps supplementary observation is + + align:start position:0% +perhaps supplementary observation is + + + align:start position:0% +perhaps supplementary observation is +that when + + align:start position:0% +that when + + + align:start position:0% +that when +we were doing stuff a long time ago it + + align:start position:0% +we were doing stuff a long time ago it + + + align:start position:0% +we were doing stuff a long time ago it +was regarded as a great success if you + + align:start position:0% +was regarded as a great success if you + + + align:start position:0% +was regarded as a great success if you +could get a program to do something for + + align:start position:0% +could get a program to do something for + + + align:start position:0% +could get a program to do something for +the first time and the feel taken over + + align:start position:0% +the first time and the feel taken over + + + align:start position:0% +the first time and the feel taken over +by people want to measure how much + + align:start position:0% +by people want to measure how much + + + align:start position:0% +by people want to measure how much +better your thing is than the next thing + + align:start position:0% +better your thing is than the next thing + + + align:start position:0% +better your thing is than the next thing +and there only a few kinds of problems + + align:start position:0% +and there only a few kinds of problems + + + align:start position:0% +and there only a few kinds of problems +that are suscep to kind scoring + + align:start position:0% +that are suscep to kind scoring + + + align:start position:0% +that are suscep to kind scoring +comparison as a consequence people + + align:start position:0% +comparison as a consequence people + + + align:start position:0% +comparison as a consequence people +working on those of problems are not + + align:start position:0% +working on those of problems are not + + + align:start position:0% +working on those of problems are not +doing things that ought to be + + align:start position:0% +doing things that ought to be + + + align:start position:0% +doing things that ought to be +done like doing + + align:start position:0% + + + + align:start position:0% + +mhm so it's a lot easier to write an + + align:start position:0% +mhm so it's a lot easier to write an + + + align:start position:0% +mhm so it's a lot easier to write an +article about how your par is 1% better + + align:start position:0% +article about how your par is 1% better + + + align:start position:0% +article about how your par is 1% better +than somebody else's part to get a + + align:start position:0% +than somebody else's part to get a + + + align:start position:0% +than somebody else's part to get a +program have common sense + + align:start position:0% +program have common sense + + + align:start position:0% +program have common sense +for + + align:start position:0% +for + + + align:start position:0% +for +yeah well now there are four or five + + align:start position:0% +yeah well now there are four or five + + + align:start position:0% +yeah well now there are four or five +common sense research groups I + + align:start position:0% +common sense research groups I + + + align:start position:0% +common sense research groups I +think how many + + align:start position:0% + + + + align:start position:0% + +I don't know if any of them make a + + align:start position:0% +I don't know if any of them make a + + + align:start position:0% +I don't know if any of them make a +living + + align:start position:0% + + + + align:start position:0% + +yet they're collecting common sense I'm + + align:start position:0% +yet they're collecting common sense I'm + + + align:start position:0% +yet they're collecting common sense I'm +not sure they have common sense + + align:start position:0% +not sure they have common sense + + + align:start position:0% +not sure they have common sense +mhm and you can measure how many how + + align:start position:0% +mhm and you can measure how many how + + + align:start position:0% +mhm and you can measure how many how +many things you know + + align:start position:0% +many things you know + + + align:start position:0% +many things you know +but it's not they're measuring how + + align:start position:0% +but it's not they're measuring how + + + align:start position:0% +but it's not they're measuring how +effective they + + align:start position:0% +effective they + + + align:start position:0% +effective they +are yeah + + align:start position:0% + + + + align:start position:0% + +I wonder how hard it would be to make a + + align:start position:0% +I wonder how hard it would be to make a + + + align:start position:0% +I wonder how hard it would be to make a +program that that knows + + align:start position:0% +program that that knows + + + align:start position:0% +program that that knows +mathematics and a lot of + + align:start position:0% +mathematics and a lot of + + + align:start position:0% +mathematics and a lot of +mathematics and does the kinds of things + + align:start position:0% +mathematics and does the kinds of things + + + align:start position:0% +mathematics and does the kinds of things +that that mathematicians + + align:start position:0% + + + + align:start position:0% + +do but somebody would have to pay them + + align:start position:0% +do but somebody would have to pay them + + + align:start position:0% +do but somebody would have to pay them +to do it and that's where do you get + + align:start position:0% +to do it and that's where do you get + + + align:start position:0% +to do it and that's where do you get +support for common sense of in + + align:start position:0% +support for common sense of in + + + align:start position:0% +support for common sense of in +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +reasoning it's a beautiful + + align:start position:0% +reasoning it's a beautiful + + + align:start position:0% +reasoning it's a beautiful +subject well there was L and there was + + align:start position:0% +subject well there was L and there was + + + align:start position:0% +subject well there was L and there was +Maxima and there was slal and there was + + align:start position:0% +Maxima and there was slal and there was + + + align:start position:0% +Maxima and there was slal and there was +Moses mhm so lots + + align:start position:0% +Moses mhm so lots + + + align:start position:0% +Moses mhm so lots +of + + align:start position:0% +of + + + align:start position:0% +of +and right and + + align:start position:0% + + + + align:start position:0% + +wol it might be for all its faults well + + align:start position:0% +wol it might be for all its faults well + + + align:start position:0% +wol it might be for all its faults well +wfrs going to get people to work on real + + align:start position:0% +wfrs going to get people to work on real + + + align:start position:0% +wfrs going to get people to work on real +AI + + align:start position:0% + + + + align:start position:0% + +because + + align:start position:0% +because + + + align:start position:0% +because +he's he's hired some people to try to + + align:start position:0% +he's he's hired some people to try to + + + align:start position:0% +he's he's hired some people to try to +make what's it called Wolfram Alpha at + + align:start position:0% +make what's it called Wolfram Alpha at + + + align:start position:0% +make what's it called Wolfram Alpha at +school to make it have more and more + + align:start position:0% +school to make it have more and more + + + align:start position:0% +school to make it have more and more +common + + align:start position:0% + + + + align:start position:0% + +sense yeah + + align:start position:0% +sense yeah + + + align:start position:0% +sense yeah +um I also think the + + align:start position:0% +um I also think the + + + align:start position:0% +um I also think the +big the challenges to try to make + + align:start position:0% +big the challenges to try to make + + + align:start position:0% +big the challenges to try to make +systems that want to do math or things + + align:start position:0% +systems that want to do math or things + + + align:start position:0% +systems that want to do math or things +that mathematicians do is deciding what + + align:start position:0% +that mathematicians do is deciding what + + + align:start position:0% +that mathematicians do is deciding what +problems are interesting wants to work + + align:start position:0% +problems are interesting wants to work + + + align:start position:0% +problems are interesting wants to work +on is there are there is automatic proof + + align:start position:0% +on is there are there is automatic proof + + + align:start position:0% +on is there are there is automatic proof +verification improving although those + + align:start position:0% +verification improving although those + + + align:start position:0% +verification improving although those +are also rather difficult problems when + + align:start position:0% +are also rather difficult problems when + + + align:start position:0% +are also rather difficult problems when +you get complicated things that don't + + align:start position:0% +you get complicated things that don't + + + align:start position:0% +you get complicated things that don't +seem to work out as well + + align:start position:0% +seem to work out as well + + + align:start position:0% +seem to work out as well +but what should be proven is something + + align:start position:0% +but what should be proven is something + + + align:start position:0% +but what should be proven is something +that I've never seen T tackled and + + align:start position:0% +that I've never seen T tackled and + + + align:start position:0% +that I've never seen T tackled and +doesn't seem + + align:start position:0% +doesn't seem + + + align:start position:0% +doesn't seem +all that P + + align:start position:0% + + + + align:start position:0% + +the well Doug L's first piece of work + + align:start position:0% +the well Doug L's first piece of work + + + align:start position:0% +the well Doug L's first piece of work +was on a thesis that um did a kind of + + align:start position:0% +was on a thesis that um did a kind of + + + align:start position:0% +was on a thesis that um did a kind of +mathematical exploration on the basis + + align:start position:0% +mathematical exploration on the basis + + + align:start position:0% +mathematical exploration on the basis +of some theory of why a piece of math + + align:start position:0% +of some theory of why a piece of math + + + align:start position:0% +of some theory of why a piece of math +why why an expression or a + + align:start position:0% +why why an expression or a + + + align:start position:0% +why why an expression or a +transformation might be interesting so + + align:start position:0% +transformation might be interesting so + + + align:start position:0% +transformation might be interesting so +even that had had some prec oh really + + align:start position:0% +even that had had some prec oh really + + + align:start position:0% +even that had had some prec oh really +and it was + + align:start position:0% +and it was + + + align:start position:0% +and it was +uh it was a system that started from + + align:start position:0% +uh it was a system that started from + + + align:start position:0% +uh it was a system that started from +scratch and proved a few theorems and + + align:start position:0% +scratch and proved a few theorems and + + + align:start position:0% +scratch and proved a few theorems and +looked around for things that were + + align:start position:0% +looked around for things that were + + + align:start position:0% +looked around for things that were +interesting and invented the opposite of + + align:start position:0% +interesting and invented the opposite of + + + align:start position:0% +interesting and invented the opposite of +uh police com advisor or something like + + align:start position:0% +uh police com advisor or something like + + + align:start position:0% +uh police com advisor or something like +that yeah that was + + align:start position:0% +that yeah that was + + + align:start position:0% +that yeah that was +am yeah and it was pretty exciting + + align:start position:0% +am yeah and it was pretty exciting + + + align:start position:0% +am yeah and it was pretty exciting +and that's something that uh anybody + + align:start position:0% +and that's something that uh anybody + + + align:start position:0% +and that's something that uh anybody +could could take up again any time and U + + align:start position:0% +could could take up again any time and U + + + align:start position:0% +could could take up again any time and U +be a great thesis topic + + align:start position:0% +be a great thesis topic + + + align:start position:0% +be a great thesis topic +uh + + align:start position:0% +uh + + + align:start position:0% +uh +lenet the phenomenon in am was that it + + align:start position:0% +lenet the phenomenon in am was that it + + + align:start position:0% +lenet the phenomenon in am was that it +did it discovered Division and prime + + align:start position:0% +did it discovered Division and prime + + + align:start position:0% +did it discovered Division and prime +numbers and and a number I think I + + align:start position:0% +numbers and and a number I think I + + + align:start position:0% +numbers and and a number I think I +talked about it uh and as as Pat says it + + align:start position:0% +talked about it uh and as as Pat says it + + + align:start position:0% +talked about it uh and as as Pat says it +was it had a bunch of Criterion for + + align:start position:0% +was it had a bunch of Criterion for + + + align:start position:0% +was it had a bunch of Criterion for +interestingness and it would find you + + align:start position:0% +interestingness and it would find you + + + align:start position:0% +interestingness and it would find you +know sets that were unusually large or + + align:start position:0% +know sets that were unusually large or + + + align:start position:0% +know sets that were unusually large or +unusually + + align:start position:0% +unusually + + + align:start position:0% +unusually +small uh and uh try to make more things + + align:start position:0% +small uh and uh try to make more things + + + align:start position:0% +small uh and uh try to make more things +like them and that sort of thing but uh + + align:start position:0% +like them and that sort of thing but uh + + + align:start position:0% +like them and that sort of thing but uh +it it's never been followed up + + align:start position:0% + + + + align:start position:0% + +and school + + align:start position:0% +and school + + + align:start position:0% +and school +olyp yeah high school algebra is a + + align:start position:0% +olyp yeah high school algebra is a + + + align:start position:0% +olyp yeah high school algebra is a +wonderful area and there was BOS thesis + + align:start position:0% +wonderful area and there was BOS thesis + + + align:start position:0% +wonderful area and there was BOS thesis +which did a little bit of it and I've + + align:start position:0% +which did a little bit of it and I've + + + align:start position:0% +which did a little bit of it and I've +never seen now there's so much more + + align:start position:0% +never seen now there's so much more + + + align:start position:0% +never seen now there's so much more +known about natural language You' think + + align:start position:0% +known about natural language You' think + + + align:start position:0% +known about natural language You' think +some somebody would do a super babro + + align:start position:0% +some somebody would do a super babro + + + align:start position:0% +some somebody would do a super babro +program that might actually be good + + align:start position:0% +program that might actually be good + + + align:start position:0% +program that might actually be good +enough to connect into Google so that it + + align:start position:0% +enough to connect into Google so that it + + + align:start position:0% +enough to connect into Google so that it +would solve problems that people real + + align:start position:0% +would solve problems that people real + + + align:start position:0% +would solve problems that people real +people face every now and + + align:start position:0% +people face every now and + + + align:start position:0% +people face every now and +then + + align:start position:0% + + + + align:start position:0% + +so yeah the appearance + + align:start position:0% +so yeah the appearance + + + align:start position:0% +so yeah the appearance +of of the + + align:start position:0% + + + + align:start position:0% + +uh the new Siri and dragon things which + + align:start position:0% +uh the new Siri and dragon things which + + + align:start position:0% +uh the new Siri and dragon things which +actually answer useful questions and wol + + align:start position:0% +actually answer useful questions and wol + + + align:start position:0% +actually answer useful questions and wol +from + + align:start position:0% +from + + + align:start position:0% +from +alpha uh might + + align:start position:0% + + + + align:start position:0% + +change there might be an industry in in + + align:start position:0% +change there might be an industry in in + + + align:start position:0% +change there might be an industry in in +common sense + + align:start position:0% +common sense + + + align:start position:0% +common sense +AI uh that's actually useful because a + + align:start position:0% +AI uh that's actually useful because a + + + align:start position:0% +AI uh that's actually useful because a +few million people might start using it + + align:start position:0% +few million people might start using it + + + align:start position:0% +few million people might start using it +as soon as it gets just a little bit + + align:start position:0% +as soon as it gets just a little bit + + + align:start position:0% +as soon as it gets just a little bit +better and uh I find that dragon and + + align:start position:0% +better and uh I find that dragon and + + + align:start position:0% +better and uh I find that dragon and +Siri I haven't used Siri but dragon now + + align:start position:0% +Siri I haven't used Siri but dragon now + + + align:start position:0% +Siri I haven't used Siri but dragon now +uh has a thing called Dragon search you + + align:start position:0% +uh has a thing called Dragon search you + + + align:start position:0% +uh has a thing called Dragon search you +talk to it and + + align:start position:0% +talk to it and + + + align:start position:0% +talk to it and +uh ask a question in ordinary English + + align:start position:0% +uh ask a question in ordinary English + + + align:start position:0% +uh ask a question in ordinary English +and it goes to the web and makes a uh + + align:start position:0% +and it goes to the web and makes a uh + + + align:start position:0% +and it goes to the web and makes a uh +Google search sentence out of what you + + align:start position:0% +Google search sentence out of what you + + + align:start position:0% +Google search sentence out of what you +said and good fraction of the time it + + align:start position:0% +said and good fraction of the time it + + + align:start position:0% +said and good fraction of the time it +saves you a half hour of + + align:start position:0% + + + + align:start position:0% + +search none of those really have any + + align:start position:0% +search none of those really have any + + + align:start position:0% +search none of those really have any +idea of context though like a very + + align:start position:0% +idea of context though like a very + + + align:start position:0% +idea of context though like a very +simple Improvement would be and wolf + + align:start position:0% +simple Improvement would be and wolf + + + align:start position:0% +simple Improvement would be and wolf +from Mal already does this a little bit + + align:start position:0% +from Mal already does this a little bit + + + align:start position:0% +from Mal already does this a little bit +as to say it assuming that you meant X + + align:start position:0% +as to say it assuming that you meant X + + + align:start position:0% +as to say it assuming that you meant X +did you mean y or Z and you can click + + align:start position:0% +did you mean y or Z and you can click + + + align:start position:0% +did you mean y or Z and you can click +those instead and that's as far as the + + align:start position:0% +those instead and that's as far as the + + + align:start position:0% +those instead and that's as far as the +conversation we pull from out right but + + align:start position:0% +conversation we pull from out right but + + + align:start position:0% +conversation we pull from out right but +you're a person and if it had a lot of + + align:start position:0% +you're a person and if it had a lot of + + + align:start position:0% +you're a person and if it had a lot of +information about + + align:start position:0% +information about + + + align:start position:0% +information about +you uh uh you could collect first of all + + align:start position:0% +you uh uh you could collect first of all + + + align:start position:0% +you uh uh you could collect first of all +it would say what kind of person are you + + align:start position:0% +it would say what kind of person are you + + + align:start position:0% +it would say what kind of person are you +and you'd give your biography and maybe + + align:start position:0% +and you'd give your biography and maybe + + + align:start position:0% +and you'd give your biography and maybe +we'll get comments sense databases that + + align:start position:0% +we'll get comments sense databases that + + + align:start position:0% +we'll get comments sense databases that +say well here are the kinds of things + + align:start position:0% +say well here are the kinds of things + + + align:start position:0% +say well here are the kinds of things +that uh somebody who likes pole vating + + align:start position:0% +that uh somebody who likes pole vating + + + align:start position:0% +that uh somebody who likes pole vating +is likely to + + align:start position:0% +is likely to + + + align:start position:0% +is likely to +know we already have the the what kind + + align:start position:0% +know we already have the the what kind + + + align:start position:0% +know we already have the the what kind +of person are you uh databases in social + + align:start position:0% +of person are you uh databases in social + + + align:start position:0% +of person are you uh databases in social +networks that's what it is right M or + + align:start position:0% +networks that's what it is right M or + + + align:start position:0% +networks that's what it is right M or +Google's personalized search + + align:start position:0% +Google's personalized search + + + align:start position:0% +Google's personalized search +yeah well I just joined Facebook by + + align:start position:0% + + + + align:start position:0% + +mistake and all sorts of people want to + + align:start position:0% +mistake and all sorts of people want to + + + align:start position:0% +mistake and all sorts of people want to +link and all you have to do is look at + + align:start position:0% +link and all you have to do is look at + + + align:start position:0% +link and all you have to do is look at +their biography and see what music they + + align:start position:0% +their biography and see what music they + + + align:start position:0% +their biography and see what music they +like and you can see you don't want to + + align:start position:0% +like and you can see you don't want to + + + align:start position:0% +like and you can see you don't want to +have that person as a + + align:start position:0% +have that person as a + + + align:start position:0% +have that person as a +friend but I wish uh has anybody written + + align:start position:0% +friend but I wish uh has anybody written + + + align:start position:0% +friend but I wish uh has anybody written +a program to automate + + align:start position:0% +a program to automate + + + align:start position:0% +a program to automate +this I could tell them I don't like + + align:start position:0% +this I could tell them I don't like + + + align:start position:0% +this I could tell them I don't like +music written in the last 20 + + align:start position:0% +music written in the last 20 + + + align:start position:0% +music written in the last 20 +years uh and that would get rid of about + + align:start position:0% +years uh and that would get rid of about + + + align:start position:0% +years uh and that would get rid of about +half of them right off + + align:start position:0% +half of them right off + + + align:start position:0% +half of them right off +of course there might be Freeman Dyson + + align:start position:0% +of course there might be Freeman Dyson + + + align:start position:0% +of course there might be Freeman Dyson +or somebody happens to like one of these + + align:start position:0% +or somebody happens to like one of these + + + align:start position:0% +or somebody happens to like one of these +Tunes I don't know so then you have + + align:start position:0% +Tunes I don't know so then you have + + + align:start position:0% +Tunes I don't know so then you have +to so you have to make a + + align:start position:0% +to so you have to make a + + + align:start position:0% +to so you have to make a +hierarchy if the person happens to be a + + align:start position:0% +hierarchy if the person happens to be a + + + align:start position:0% +hierarchy if the person happens to be a +really good physicist then then we'll + + align:start position:0% +really good physicist then then we'll + + + align:start position:0% +really good physicist then then we'll +flush that particular filter + + align:start position:0% + + + + align:start position:0% + +yeah also Google's personalized search + + align:start position:0% +yeah also Google's personalized search + + + align:start position:0% +yeah also Google's personalized search +profile thinks that I'm a man because + + align:start position:0% +profile thinks that I'm a man because + + + align:start position:0% +profile thinks that I'm a man because +apparently I've searched too many + + align:start position:0% +apparently I've searched too many + + + align:start position:0% +apparently I've searched too many +computer science things in the + + align:start position:0% +computer science things in the + + + align:start position:0% +computer science things in the +past that's pretty + + align:start position:0% + + + + align:start position:0% + +good maybe thinks most people are a man + + align:start position:0% +good maybe thinks most people are a man + + + align:start position:0% +good maybe thinks most people are a man +oh I don't know like with with other + + align:start position:0% +oh I don't know like with with other + + + align:start position:0% +oh I don't know like with with other +women they they get it right but like if + + align:start position:0% +women they they get it right but like if + + + align:start position:0% +women they they get it right but like if +you're if you happen to be you know um a + + align:start position:0% +you're if you happen to be you know um a + + + align:start position:0% +you're if you happen to be you know um a +woman who does computer techage stuff + + align:start position:0% +woman who does computer techage stuff + + + align:start position:0% +woman who does computer techage stuff +and if you happen to do a lot of search + + align:start position:0% +and if you happen to do a lot of search + + + align:start position:0% +and if you happen to do a lot of search +on like programming for instance like + + align:start position:0% +on like programming for instance like + + + align:start position:0% +on like programming for instance like +looking up apis of things then it it + + align:start position:0% +looking up apis of things then it it + + + align:start position:0% +looking up apis of things then it it +tends to try to think that you're a man + + align:start position:0% +tends to try to think that you're a man + + + align:start position:0% +tends to try to think that you're a man +does it store the gender as a Boolean or + + align:start position:0% +does it store the gender as a Boolean or + + + align:start position:0% +does it store the gender as a Boolean or +is + + align:start position:0% +is + + + align:start position:0% +is +it I I saw this like a while ago and it + + align:start position:0% +it I I saw this like a while ago and it + + + align:start position:0% +it I I saw this like a while ago and it +was just like according to this it + + align:start position:0% +was just like according to this it + + + align:start position:0% +was just like according to this it +here's what they think that you are and + + align:start position:0% +here's what they think that you are and + + + align:start position:0% +here's what they think that you are and +at the top it was like we think you're a + + align:start position:0% +at the top it was like we think you're a + + + align:start position:0% +at the top it was like we think you're a +man I I'm interested to know though like + + align:start position:0% +man I I'm interested to know though like + + + align:start position:0% +man I I'm interested to know though like +how manly exactly you + + align:start position:0% +how manly exactly you + + + align:start position:0% +how manly exactly you +become so I don't think they actually + + align:start position:0% +become so I don't think they actually + + + align:start position:0% +become so I don't think they actually +tell you like their internal + + align:start position:0% +tell you like their internal + + + align:start position:0% +tell you like their internal +representation of of who you are um but + + align:start position:0% +representation of of who you are um but + + + align:start position:0% +representation of of who you are um but +you just get to see like a couple + + align:start position:0% +you just get to see like a couple + + + align:start position:0% +you just get to see like a couple +categories like male 25 to 35 um + + align:start position:0% +categories like male 25 to 35 um + + + align:start position:0% +categories like male 25 to 35 um +interested in computers interested in in + + align:start position:0% +interested in computers interested in in + + + align:start position:0% +interested in computers interested in in +ETC um I'm sure they they keep it as + + align:start position:0% +ETC um I'm sure they they keep it as + + + align:start position:0% +ETC um I'm sure they they keep it as +flat + + align:start position:0% + + + + align:start position:0% + +somewhere you could cross correlate that + + align:start position:0% +somewhere you could cross correlate that + + + align:start position:0% +somewhere you could cross correlate that +with geography and be like this is the + + align:start position:0% +with geography and be like this is the + + + align:start position:0% +with geography and be like this is the +man cleanest level in a certain + + align:start position:0% + + + + align:start position:0% + +is there anything in Facebook that would + + align:start position:0% +is there anything in Facebook that would + + + align:start position:0% +is there anything in Facebook that would +help us get a common sense database or + + align:start position:0% +help us get a common sense database or + + + align:start position:0% +help us get a common sense database or +is it + + align:start position:0% +is it + + + align:start position:0% +is it +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +there's or is there + + align:start position:0% +there's or is there + + + align:start position:0% +there's or is there +no no useful + + align:start position:0% +no no useful + + + align:start position:0% +no no useful +knowledge must be something that well + + align:start position:0% +knowledge must be something that well + + + align:start position:0% +knowledge must be something that well +apparently a few years back for Hon's + + align:start position:0% +apparently a few years back for Hon's + + + align:start position:0% +apparently a few years back for Hon's +class somebody made um a program that + + align:start position:0% +class somebody made um a program that + + + align:start position:0% +class somebody made um a program that +could find out who was gay or not um + + align:start position:0% +could find out who was gay or not um + + + align:start position:0% +could find out who was gay or not um +even if they don't put gay or not gay on + + align:start position:0% +even if they don't put gay or not gay on + + + align:start position:0% +even if they don't put gay or not gay on +their profile like based on who their + + align:start position:0% +their profile like based on who their + + + align:start position:0% +their profile like based on who their +friends + + align:start position:0% +friends + + + align:start position:0% +friends +are yeah my friend is most gay they fall + + align:start position:0% +are yeah my friend is most gay they fall + + + align:start position:0% +are yeah my friend is most gay they fall +out this is my statistical is actually + + align:start position:0% +out this is my statistical is actually + + + align:start position:0% +out this is my statistical is actually +useful because you could specify that + + align:start position:0% +useful because you could specify that + + + align:start position:0% +useful because you could specify that +you're looking for someone who is 75 + + align:start position:0% + + + + align:start position:0% + +female how many women's names begin with + + align:start position:0% +female how many women's names begin with + + + align:start position:0% +female how many women's names begin with +the letter X begin with the letter x X + + align:start position:0% +the letter X begin with the letter x X + + + align:start position:0% +the letter X begin with the letter x X +that may be your + + align:start position:0% + + + + align:start position:0% + +problem yes it could + + align:start position:0% +problem yes it could + + + align:start position:0% +problem yes it could +be I heard that China is allowing more + + align:start position:0% +be I heard that China is allowing more + + + align:start position:0% +be I heard that China is allowing more +names is + + align:start position:0% +names is + + + align:start position:0% +names is +allowing well I read an article which + + align:start position:0% +allowing well I read an article which + + + align:start position:0% +allowing well I read an article which +said there only there are only about a + + align:start position:0% +said there only there are only about a + + + align:start position:0% +said there only there are only about a +hundred + + align:start position:0% +hundred + + + align:start position:0% +hundred +names + + align:start position:0% +names + + + align:start position:0% +names +in most of + + align:start position:0% +in most of + + + align:start position:0% +in most of +China and + + align:start position:0% +China and + + + align:start position:0% +China and +and uh in fact there was a law that that + + align:start position:0% +and uh in fact there was a law that that + + + align:start position:0% +and uh in fact there was a law that that +both your names have to be from this + + align:start position:0% +both your names have to be from this + + + align:start position:0% +both your names have to be from this +small + + align:start position:0% +small + + + align:start position:0% +small +set and so there are only 10,000 + + align:start position:0% +set and so there are only 10,000 + + + align:start position:0% +set and so there are only 10,000 +different pairs of + + align:start position:0% +different pairs of + + + align:start position:0% +different pairs of +names do I mean that yeah family names + + align:start position:0% +names do I mean that yeah family names + + + align:start position:0% +names do I mean that yeah family names +are there a lot of family names um well + + align:start position:0% +are there a lot of family names um well + + + align:start position:0% +are there a lot of family names um well +I feel like there aren't really + + align:start position:0% +I feel like there aren't really + + + align:start position:0% +I feel like there aren't really +restrictions for uh name as long as + + align:start position:0% +restrictions for uh name as long as + + + align:start position:0% +restrictions for uh name as long as +they're Chinese characters right I I + + align:start position:0% +they're Chinese characters right I I + + + align:start position:0% +they're Chinese characters right I I +heard about like a lawsuit in China + + align:start position:0% +heard about like a lawsuit in China + + + align:start position:0% +heard about like a lawsuit in China +where somebody wanted to named their kid + + align:start position:0% +where somebody wanted to named their kid + + + align:start position:0% +where somebody wanted to named their kid +something something.com in the + + align:start position:0% + + + + align:start position:0% + +government but as long as you pick you + + align:start position:0% +government but as long as you pick you + + + align:start position:0% +government but as long as you pick you +know like real Chinese characters you + + align:start position:0% +know like real Chinese characters you + + + align:start position:0% +know like real Chinese characters you +can name your kid like big poopy head + + align:start position:0% +can name your kid like big poopy head + + + align:start position:0% +can name your kid like big poopy head +and it's okay in fact naming your kid + + align:start position:0% +and it's okay in fact naming your kid + + + align:start position:0% +and it's okay in fact naming your kid +big poopy head is actually rather common + + align:start position:0% +big poopy head is actually rather common + + + align:start position:0% +big poopy head is actually rather common +in the countryside because there's some + + align:start position:0% +in the countryside because there's some + + + align:start position:0% +in the countryside because there's some +Superstition that believes that if your + + align:start position:0% +Superstition that believes that if your + + + align:start position:0% +Superstition that believes that if your +kid has a really terrible name then uh + + align:start position:0% +kid has a really terrible name then uh + + + align:start position:0% +kid has a really terrible name then uh +he won't die during childhood because + + align:start position:0% +he won't die during childhood because + + + align:start position:0% +he won't die during childhood because +even the devil won't want want him + + align:start position:0% + + + + align:start position:0% + +and for all we know it's + + align:start position:0% + + + + align:start position:0% + +true say knowledge are you only allowed + + align:start position:0% +true say knowledge are you only allowed + + + align:start position:0% +true say knowledge are you only allowed +to one first and last name though + + align:start position:0% +to one first and last name though + + + align:start position:0% +to one first and last name though +because it seems like you should only + + align:start position:0% +because it seems like you should only + + + align:start position:0% +because it seems like you should only +need two names and then just give + + align:start position:0% +need two names and then just give + + + align:start position:0% +need two names and then just give +everyone at most 64 names and that + + align:start position:0% +everyone at most 64 names and that + + + align:start position:0% +everyone at most 64 names and that +should cover all China I think in + + align:start position:0% +should cover all China I think in + + + align:start position:0% +should cover all China I think in +Chinese it's like um there's a set of + + align:start position:0% +Chinese it's like um there's a set of + + + align:start position:0% +Chinese it's like um there's a set of +last names that's pretty much standard + + align:start position:0% +last names that's pretty much standard + + + align:start position:0% +last names that's pretty much standard +um and I'm not sure how many maybe a few + + align:start position:0% +um and I'm not sure how many maybe a few + + + align:start position:0% +um and I'm not sure how many maybe a few +hundred um and then given names um so + + align:start position:0% +hundred um and then given names um so + + + align:start position:0% +hundred um and then given names um so +family names are usually one character + + align:start position:0% +family names are usually one character + + + align:start position:0% +family names are usually one character +but occasionally they're two characters + + align:start position:0% +but occasionally they're two characters + + + align:start position:0% +but occasionally they're two characters +and um given names are either one or two + + align:start position:0% +and um given names are either one or two + + + align:start position:0% +and um given names are either one or two +characters and you just get those two uh + + align:start position:0% +characters and you just get those two uh + + + align:start position:0% +characters and you just get those two uh +and you can pick any character oh well + + align:start position:0% +and you can pick any character oh well + + + align:start position:0% +and you can pick any character oh well +there are a lot of characters yeah like + + align:start position:0% +there are a lot of characters yeah like + + + align:start position:0% +there are a lot of characters yeah like +several thousand yeah but so it's it's + + align:start position:0% +several thousand yeah but so it's it's + + + align:start position:0% +several thousand yeah but so it's it's +something like a thousand by a + + align:start position:0% + + + + align:start position:0% + +th000 300 + + align:start position:0% + + + + align:start position:0% + +35 maybe another 3000 the British + + align:start position:0% +35 maybe another 3000 the British + + + align:start position:0% +35 maybe another 3000 the British +solution is to just keep add simple + + align:start position:0% +solution is to just keep add simple + + + align:start position:0% +solution is to just keep add simple +names like my brother's name is Dylan + + align:start position:0% +names like my brother's name is Dylan + + + align:start position:0% +names like my brother's name is Dylan +Neville Thomas + + align:start position:0% +Neville Thomas + + + align:start position:0% +Neville Thomas +Bedford and you can just keep changing + + align:start position:0% +Bedford and you can just keep changing + + + align:start position:0% +Bedford and you can just keep changing +names and then if you get stuck with too + + align:start position:0% +names and then if you get stuck with too + + + align:start position:0% +names and then if you get stuck with too +many John Smiths you just do thirds + + align:start position:0% +many John Smiths you just do thirds + + + align:start position:0% +many John Smiths you just do thirds +fourths + + align:start position:0% +fourths + + + align:start position:0% +fourths +fifths well the article I read must have + + align:start position:0% +fifths well the article I read must have + + + align:start position:0% +fifths well the article I read must have +been wrong then or I misunderstood it + + align:start position:0% +been wrong then or I misunderstood it + + + align:start position:0% +been wrong then or I misunderstood it +because it said somewhere areas of China + + align:start position:0% +because it said somewhere areas of China + + + align:start position:0% +because it said somewhere areas of China +there are only a hundred names so if you + + align:start position:0% +there are only a hundred names so if you + + + align:start position:0% +there are only a hundred names so if you +have + + align:start position:0% +have + + + align:start position:0% +have +more than 10,000 people you get people + + align:start position:0% +more than 10,000 people you get people + + + align:start position:0% +more than 10,000 people you get people +with the same name + + align:start position:0% +with the same name + + + align:start position:0% +with the same name +and anyway that's their + + align:start position:0% + + + + align:start position:0% + +problem maybe the person who wrote the + + align:start position:0% +problem maybe the person who wrote the + + + align:start position:0% +problem maybe the person who wrote the +article couldn't tell the difference + + align:start position:0% +article couldn't tell the difference + + + align:start position:0% +article couldn't tell the difference +between their friend shoe and their + + align:start position:0% +between their friend shoe and their + + + align:start position:0% +between their friend shoe and their +friend + + align:start position:0% +friend + + + align:start position:0% +friend +Sho yeah well one thing that they also + + align:start position:0% +Sho yeah well one thing that they also + + + align:start position:0% +Sho yeah well one thing that they also +did historically in China is that + + align:start position:0% +did historically in China is that + + + align:start position:0% +did historically in China is that +sometimes people have m names and the + + align:start position:0% +sometimes people have m names and the + + + align:start position:0% +sometimes people have m names and the +middle names is based on this uh thing + + align:start position:0% +middle names is based on this uh thing + + + align:start position:0% +middle names is based on this uh thing +that was like written centuries ago that + + align:start position:0% +that was like written centuries ago that + + + align:start position:0% +that was like written centuries ago that +for each generation it has a set + + align:start position:0% +for each generation it has a set + + + align:start position:0% +for each generation it has a set +character that must be your middle name + + align:start position:0% +character that must be your middle name + + + align:start position:0% +character that must be your middle name +so your name will be like family name um + + align:start position:0% +so your name will be like family name um + + + align:start position:0% +so your name will be like family name um +this middle name and then your actual + + align:start position:0% +this middle name and then your actual + + + align:start position:0% +this middle name and then your actual +given name so I don't know maybe that + + align:start position:0% +given name so I don't know maybe that + + + align:start position:0% +given name so I don't know maybe that +but that's sort of like becoming more + + align:start position:0% +but that's sort of like becoming more + + + align:start position:0% +but that's sort of like becoming more +obsolete nowadays mhm well in English we + + align:start position:0% +obsolete nowadays mhm well in English we + + + align:start position:0% +obsolete nowadays mhm well in English we +have lots of names like farmer and + + align:start position:0% +have lots of names like farmer and + + + align:start position:0% +have lots of names like farmer and +painter and so forth but people don't + + align:start position:0% +painter and so forth but people don't + + + align:start position:0% +painter and so forth but people don't +live up to them much + + align:start position:0% + + + + align:start position:0% + +mhm because it's difficult to tell what + + align:start position:0% +mhm because it's difficult to tell what + + + align:start position:0% +mhm because it's difficult to tell what +a given baby is going to + + align:start position:0% +a given baby is going to + + + align:start position:0% +a given baby is going to +do but you can order it + + align:start position:0% + + + + align:start position:0% + +around but actually the the historic + + align:start position:0% +around but actually the the historic + + + align:start position:0% +around but actually the the historic +Chinese system is kind of an interesting + + align:start position:0% +Chinese system is kind of an interesting + + + align:start position:0% +Chinese system is kind of an interesting +way of addressing um people like + + align:start position:0% +way of addressing um people like + + + align:start position:0% +way of addressing um people like +indexing people cuz you have the first + + align:start position:0% +indexing people cuz you have the first + + + align:start position:0% +indexing people cuz you have the first +character which is the family and then + + align:start position:0% +character which is the family and then + + + align:start position:0% +character which is the family and then +the second character is the generation + + align:start position:0% +the second character is the generation + + + align:start position:0% +the second character is the generation +and then the third character is you so + + align:start position:0% +and then the third character is you so + + + align:start position:0% +and then the third character is you so +it's like you know if your family is X + + align:start position:0% +it's like you know if your family is X + + + align:start position:0% +it's like you know if your family is X +and you're from generation a then um + + align:start position:0% +and you're from generation a then um + + + align:start position:0% +and you're from generation a then um +your siblings will be like X AA or xab + + align:start position:0% +your siblings will be like X AA or xab + + + align:start position:0% +your siblings will be like X AA or xab +xac whatever um and then like the next + + align:start position:0% +xac whatever um and then like the next + + + align:start position:0% +xac whatever um and then like the next +generation will be like + + align:start position:0% +generation will be like + + + align:start position:0% +generation will be like +XB whatever okay maybe I should have + + align:start position:0% +XB whatever okay maybe I should have + + + align:start position:0% +XB whatever okay maybe I should have +picked different + + align:start position:0% +picked different + + + align:start position:0% +picked different +uh but you know what I mean oh + + align:start position:0% +uh but you know what I mean oh + + + align:start position:0% +uh but you know what I mean oh +generation number kind of except for + + align:start position:0% +generation number kind of except for + + + align:start position:0% +generation number kind of except for +it's a character + + align:start position:0% +it's a character + + + align:start position:0% +it's a character +mhm there should be enough IPv6 + + align:start position:0% + + + + align:start position:0% + +as I feel like you're just going to end + + align:start position:0% +as I feel like you're just going to end + + + align:start position:0% +as I feel like you're just going to end +up with us all being numbers X + + align:start position:0% +up with us all being numbers X + + + align:start position:0% +up with us all being numbers X +so that being said i' I've always wanted + + align:start position:0% +so that being said i' I've always wanted + + + align:start position:0% +so that being said i' I've always wanted +to name my kids something that rhym with + + align:start position:0% +to name my kids something that rhym with + + + align:start position:0% +to name my kids something that rhym with +the letter like 1 two 3 4 so that like I + + align:start position:0% +the letter like 1 two 3 4 so that like I + + + align:start position:0% +the letter like 1 two 3 4 so that like I +can just call them by their their + + align:start position:0% +can just call them by their their + + + align:start position:0% +can just call them by their their +number without realizing that I'm + + align:start position:0% +number without realizing that I'm + + + align:start position:0% +number without realizing that I'm +calling them by number that's good great + + align:start position:0% +calling them by number that's good great + + + align:start position:0% +calling them by number that's good great +idea + + align:start position:0% +idea + + + align:start position:0% +idea +yeah I + + align:start position:0% + + + + align:start position:0% + +think name it could be the number of + + align:start position:0% +think name it could be the number of + + + align:start position:0% +think name it could be the number of +letters in the + + align:start position:0% +letters in the + + + align:start position:0% +letters in the +name like + + align:start position:0% + + + + align:start position:0% + +four you name your fourth kid + + align:start position:0% +four you name your fourth kid + + + align:start position:0% +four you name your fourth kid +Forest come + + align:start position:0% + + + + align:start position:0% + +here or name your third kid + + align:start position:0% + + + + align:start position:0% + +trade eventually the name name could be + + align:start position:0% +trade eventually the name name could be + + + align:start position:0% +trade eventually the name name could be +longer and it could be a whole little + + align:start position:0% +longer and it could be a whole little + + + align:start position:0% +longer and it could be a whole little +semantic net with little list structure + + align:start position:0% +semantic net with little list structure + + + align:start position:0% +semantic net with little list structure +in it + + align:start position:0% + + + + align:start position:0% + +and there was a nice science fiction + + align:start position:0% +and there was a nice science fiction + + + align:start position:0% +and there was a nice science fiction +story about some culture where + + align:start position:0% +story about some culture where + + + align:start position:0% +story about some culture where +they + + align:start position:0% +they + + + align:start position:0% +they +to where you had to know your + + align:start position:0% +to where you had to know your + + + align:start position:0% +to where you had to know your +genealogy back hundreds of generations I + + align:start position:0% +genealogy back hundreds of generations I + + + align:start position:0% +genealogy back hundreds of generations I +forgot the + + align:start position:0% +forgot the + + + align:start position:0% +forgot the +author but it was made into a movie + + align:start position:0% + + + + align:start position:0% + +well who wants the last + + align:start position:0% + + + + align:start position:0% + +word + + align:start position:0% + + + + align:start position:0% + +DUS someone else can have it yeah do we + + align:start position:0% +DUS someone else can have it yeah do we + + + align:start position:0% +DUS someone else can have it yeah do we +have any announcement to make + + align:start position:0% +have any announcement to make + + + align:start position:0% +have any announcement to make +no just final projects would do on + + align:start position:0% +no just final projects would do on + + + align:start position:0% +no just final projects would do on +Sunday + + align:start position:0% +Sunday + + + align:start position:0% +Sunday +that's do you know what you're teaching + + align:start position:0% +that's do you know what you're teaching + + + align:start position:0% +that's do you know what you're teaching +next semester we're trying to make a + + align:start position:0% +next semester we're trying to make a + + + align:start position:0% +next semester we're trying to make a +plan for a some kind of weekly seminar + + align:start position:0% +plan for a some kind of weekly seminar + + + align:start position:0% +plan for a some kind of weekly seminar +that's not for + + align:start position:0% +that's not for + + + align:start position:0% +that's not for +credit + + align:start position:0% +credit + + + align:start position:0% +credit +uh although I might have to make it for + + align:start position:0% +uh although I might have to make it for + + + align:start position:0% +uh although I might have to make it for +credit for financial reasons or nobody + + align:start position:0% +credit for financial reasons or nobody + + + align:start position:0% +credit for financial reasons or nobody +will pay + + align:start position:0% + + + + align:start position:0% + +me but uh we could go back to giving + + align:start position:0% +me but uh we could go back to giving + + + align:start position:0% +me but uh we could go back to giving +everyone A's + + align:start position:0% + + + + align:start position:0% + +again so you won't be teaching this + + align:start position:0% +again so you won't be teaching this + + + align:start position:0% +again so you won't be teaching this +subject until next fall I guess not uh I + + align:start position:0% +subject until next fall I guess not uh I + + + align:start position:0% +subject until next fall I guess not uh I +haven't absolutely decided but I'm + + align:start position:0% +haven't absolutely decided but I'm + + + align:start position:0% +haven't absolutely decided but I'm +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +sure can they take your + + align:start position:0% +sure can they take your + + + align:start position:0% +sure can they take your +class how much how many students do you + + align:start position:0% +class how much how many students do you + + + align:start position:0% +class how much how many students do you +have each + + align:start position:0% +have each + + + align:start position:0% +have each +year well we've got room for about 40 + + align:start position:0% +year well we've got room for about 40 + + + align:start position:0% +year well we've got room for about 40 +and usually about 120 sign up mhm + + align:start position:0% + + + + align:start position:0% + +and then you weed them + + align:start position:0% +and then you weed them + + + align:start position:0% +and then you weed them +out + + align:start position:0% + + + + align:start position:0% + +yes I'd like to borrow your reading + + align:start position:0% +yes I'd like to borrow your reading + + + align:start position:0% +yes I'd like to borrow your reading +program okay well thank you all for + + align:start position:0% +program okay well thank you all for + + + align:start position:0% +program okay well thank you all for +coming it's been fun + + align:start position:0% +coming it's been fun + + + align:start position:0% +coming it's been fun +[Applause] \ No newline at end of file diff --git a/TV6AtNbmLBE.txt b/TV6AtNbmLBE.txt new file mode 100644 index 0000000000000000000000000000000000000000..4aa9052296c92972e5dbe84518b30afdd8c76662 --- /dev/null +++ b/TV6AtNbmLBE.txt @@ -0,0 +1,219 @@ +Okay, let's review our plan. + +The processor starts an access by sending +an address to the cache. + +If data for the requested address is held +in the cache, it's quickly returned to the + +CPU. + +If the data we request is not in the cache, +we have a cache miss, so the cache has to + +make a request to main memory to get the data, +which it then returns to processor. + +Typically the cache will remember the newly +fetched data, possibly replacing some older + +data in the cache. + +Suppose a cache access takes 4 ns and a main +memory access takes 40 ns. + +Then an access that hits in the cache has +a latency of 4 ns, but an access that misses + +in the cache has a latency of 44 ns. + +The processor has to deal with the variable +memory access time, perhaps by simply waiting + +for the access to complete, or, in modern +hyper-threaded processors, it might execute + +an instruction or two from another programming +thread. + +The hit and miss ratios tell us the fraction +of accesses which are cache hits and the fraction + +of accesses which are cache misses. + +Of course, the ratios will sum to 1. + +Using these metrics we can compute the average +memory access time (AMAT). + +Since we always check in the cache first, +every access includes the cache access time + +(called the hit time). + +If we miss in the cache, we have to take the +additional time needed to access main memory + +(called the miss penalty). + +But the main memory access only happens on +some fraction of the accesses: the miss ratio + +tells us how often that occurs. + +So the AMAT can be computed using the formula +shown here. + +The lower the miss ratio (or, equivalently, +the higher the hit ratio), the smaller the + +average access time. + +Our design goal for the cache is to achieve +a high hit ratio. + +If we have multiple levels of cache, we can +apply the formula recursively to calculate + +the AMAT at each level of the memory. + +Each successive level of the cache is slower, +i.e., has a longer hit time, which is offset + +by lower miss ratio because of its increased +size. + +Let's try out some numbers. + +Suppose the cache takes 4 processor cycles +to respond, and main memory takes 100 cycles. + +Without the cache, each memory access would +take 100 cycles. + +With the cache, a cache hit takes 4 cycles, +and a cache miss takes 104 cycles. + +What hit ratio is needed to so that the AMAT +with the cache is 100 cycles, the break-even + +point? + +Using the AMAT formula from the previously +slide, we see that we only need a hit ratio + +of 4% in order for memory system of the Cache ++ Main Memory to perform as well as Main Memory + +alone. + +The idea, of course, is that we'll be able +to do much better than that. + +Suppose we wanted an AMAT of 5 cycles. + +Clearly most of the accesses would have to +be cache hits. + +We can use the AMAT formula to compute the +necessary hit ratio. + +Working through the arithmetic we see that +99% of the accesses must be cache hits in + +order to achieve an average access time of +5 cycles. + +Could we expect to do that well when running +actual programs? + +Happily, we can come close. + +In a simulation of the Spec CPU2000 Benchmark, +the hit ratio for a standard-size level 1 + +cache was measured to be 97.5% over some ~10 +trillion accesses. + +[See the "All benchmarks" arithmetic-mean +table at http://research.cs.wisc.edu/multifacet/misc/spec2000cache-data/] + +Here's a start at building a cache. + +The cache will hold many different blocks +of data. + +For now let's assume each block is an individual +memory location. + +Each data block is "tagged" with its address. + +A combination of a data block and its associated +address tag is called a cache line. + +When an address is received from the CPU, +we'll search the cache looking for a block + +with a matching address tag. + +If we find a matching address tag, we have +a cache hit. + +On a read access, we'll return the data from +the matching cache line. + +On a write access, we'll update the data stored +in the cache line and, at some point, update + +the corresponding location in main memory. + +If no matching tag is found, we have a cache +miss. + +So we'll have to choose a cache line to use +to hold the requested data, which means that + +some previously cached location will no longer +be found in the cache. + +For a read operation, we'll fetch the requested +data from main memory, add it to the cache + +(updating the tag and data fields of the cache +line) and, of course, return the data to the + +CPU. + +On a write, we'll update the tag and data +in the selected cache line and, at some point, + +update the corresponding location in main +memory. + +So the contents of the cache is determined +by the memory requests made by the CPU. + +If the CPU requests a recently-used address, +chances are good the data will still be in + +the cache from the previous access to the +same location. + +As the working set slowly changes, the cache +contents will be updated as needed. + +If the entire working set can fit into the +cache, most of the requests will be hits and + +the AMAT will be close to the cache access +time. + +So far, so good! + +Of course, we'll need to figure how to quickly +search the cache, i.e., we'll a need fast + +way to answer the question of whether a particular +address tag can be found in some cache line. + +That's our next topic. \ No newline at end of file diff --git a/Tyajd1ZddcQ.txt b/Tyajd1ZddcQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..b4ebacc7df2996d2debbc94222724fb2335d7138 --- /dev/null +++ b/Tyajd1ZddcQ.txt @@ -0,0 +1,4403 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu are + + align:start position:0% + + + + align:start position:0% + +oh yeah look you can see the little + + align:start position:0% +oh yeah look you can see the little + + + align:start position:0% +oh yeah look you can see the little +C oh yeah sure you + + align:start position:0% +C oh yeah sure you + + + align:start position:0% +C oh yeah sure you +[Music] + + align:start position:0% + + + + align:start position:0% + +can + + align:start position:0% + + + + align:start position:0% + +down all + + align:start position:0% +down all + + + align:start position:0% +down all +right and we don't have the right sample + + align:start position:0% +right and we don't have the right sample + + + align:start position:0% +right and we don't have the right sample +on right that's right + + align:start position:0% + + + + align:start position:0% + +y + + align:start position:0% +y + + + align:start position:0% +y +what's oh yeah I think that that + + align:start position:0% + + + + align:start position:0% + +glass glassa right yep so one the little + + align:start position:0% +glass glassa right yep so one the little + + + align:start position:0% +glass glassa right yep so one the little +ones I guess oh yeah you can actually + + align:start position:0% +ones I guess oh yeah you can actually + + + align:start position:0% +ones I guess oh yeah you can actually +see + + align:start position:0% + + + + align:start position:0% + +it's + + align:start position:0% + + + + align:start position:0% + +quite so when you when you switch to + + align:start position:0% +quite so when you when you switch to + + + align:start position:0% +quite so when you when you switch to +these P leers it's fairly typical for + + align:start position:0% +these P leers it's fairly typical for + + + align:start position:0% +these P leers it's fairly typical for +them to require refocusing okay cuz + + align:start position:0% +them to require refocusing okay cuz + + + align:start position:0% +them to require refocusing okay cuz +they're significantly shorter than + + align:start position:0% + + + + align:start position:0% + +um he's + + align:start position:0% +um he's + + + align:start position:0% +um he's +coming toward you you have to loosen the + + align:start position:0% +coming toward you you have to loosen the + + + align:start position:0% +coming toward you you have to loosen the +knobs yeah + + align:start position:0% +knobs yeah + + + align:start position:0% +knobs yeah +okay all right so + + align:start position:0% + + + + align:start position:0% + +we I love this that is such a + + align:start position:0% + + + + align:start position:0% + +great not supposed to + + align:start position:0% +great not supposed to + + + align:start position:0% +great not supposed to +touch what is it that you got huh you + + align:start position:0% +touch what is it that you got huh you + + + align:start position:0% +touch what is it that you got huh you +said you must that the you color code + + align:start position:0% +said you must that the you color code + + + align:start position:0% +said you must that the you color code +which pizo power source goes with which + + align:start position:0% +which pizo power source goes with which + + + align:start position:0% +which pizo power source goes with which +switch yeah that was when they were all + + align:start position:0% +switch yeah that was when they were all + + + align:start position:0% +switch yeah that was when they were all +on the same table we had uh two + + align:start position:0% +on the same table we had uh two + + + align:start position:0% +on the same table we had uh two +incarnations of the classic basically + + align:start position:0% +incarnations of the classic basically + + + align:start position:0% +incarnations of the classic basically +one huge object set + + align:start position:0% +one huge object set + + + align:start position:0% +one huge object set +up set + + align:start position:0% + + + + align:start position:0% + +up well these three tables inside + + align:start position:0% +up well these three tables inside + + + align:start position:0% +up well these three tables inside +my it's still useful yeah all right so + + align:start position:0% +my it's still useful yeah all right so + + + align:start position:0% +my it's still useful yeah all right so +probably want to the uh + + align:start position:0% +probably want to the uh + + + align:start position:0% +probably want to the uh +down the + + align:start position:0% +down the + + + align:start position:0% +down the +scope oh yeah can get the you're still + + align:start position:0% +scope oh yeah can get the you're still + + + align:start position:0% +scope oh yeah can get the you're still +doing it with the scope I guess you're + + align:start position:0% +doing it with the scope I guess you're + + + align:start position:0% +doing it with the scope I guess you're +right who oh we took that + + align:start position:0% + + + + align:start position:0% + +ey there's a missing eye piece + + align:start position:0% +ey there's a missing eye piece + + + align:start position:0% +ey there's a missing eye piece +here + + align:start position:0% +here + + + align:start position:0% +here +not I just gave it the old + + align:start position:0% + + + + align:start position:0% + +one all + + align:start position:0% +one all + + + align:start position:0% +one all +right and so then I guess we should hit + + align:start position:0% +right and so then I guess we should hit + + + align:start position:0% +right and so then I guess we should hit +the + + align:start position:0% +the + + + align:start position:0% +the +uh align the spot on + + align:start position:0% +uh align the spot on + + + align:start position:0% +uh align the spot on +the yeah so adjust the height would you + + align:start position:0% + + + + align:start position:0% + +say + + align:start position:0% +say + + + align:start position:0% +say +cuz well I guess I can just do it by + + align:start position:0% +cuz well I guess I can just do it by + + + align:start position:0% +cuz well I guess I can just do it by +ey + + align:start position:0% +ey + + + align:start position:0% +ey +right for you're adjusting the height + + align:start position:0% +right for you're adjusting the height + + + align:start position:0% +right for you're adjusting the height +of I was thinking about adjusting the + + align:start position:0% +of I was thinking about adjusting the + + + align:start position:0% +of I was thinking about adjusting the +height of the + + align:start position:0% +height of the + + + align:start position:0% +height of the +tecture well uh okay but we could hit + + align:start position:0% +tecture well uh okay but we could hit + + + align:start position:0% +tecture well uh okay but we could hit +this uh we could try getting the L are + + align:start position:0% +this uh we could try getting the L are + + + align:start position:0% +this uh we could try getting the L are +on the uh close to the spot also yeah + + align:start position:0% +on the uh close to the spot also yeah + + + align:start position:0% +on the uh close to the spot also yeah +yeah right that's that's and that's what + + align:start position:0% +yeah right that's that's and that's what + + + align:start position:0% +yeah right that's that's and that's what +I meant sorry + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so I think you're going want these yeah + + align:start position:0% +so I think you're going want these yeah + + + align:start position:0% +so I think you're going want these yeah +I'm the stage + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +this surface of glass out so FP it over + + align:start position:0% +this surface of glass out so FP it over + + + align:start position:0% +this surface of glass out so FP it over +the first thing to + + align:start position:0% + + + + align:start position:0% + +touch all + + align:start position:0% +touch all + + + align:start position:0% +touch all +right yeah you're on the lever yeah + + align:start position:0% +right yeah you're on the lever yeah + + + align:start position:0% +right yeah you're on the lever yeah +right + + align:start position:0% +right + + + align:start position:0% +right +middle but you can also push with your + + align:start position:0% +middle but you can also push with your + + + align:start position:0% +middle but you can also push with your +finger and turn and it gets the clip out + + align:start position:0% +finger and turn and it gets the clip out + + + align:start position:0% +finger and turn and it gets the clip out +of the way and then you can turn the + + align:start position:0% +of the way and then you can turn the + + + align:start position:0% +of the way and then you can turn the +then + + align:start position:0% +then + + + align:start position:0% +then +we + + align:start position:0% + + + + align:start position:0% + +sign that makes a lot of sense it + + align:start position:0% +sign that makes a lot of sense it + + + align:start position:0% +sign that makes a lot of sense it +position here but then you look at it + + align:start position:0% +position here but then you look at it + + + align:start position:0% +position here but then you look at it +put it back or rotate it don't yeah so + + align:start position:0% +put it back or rotate it don't yeah so + + + align:start position:0% +put it back or rotate it don't yeah so +so you see the pocket goes in this + + align:start position:0% +so you see the pocket goes in this + + + align:start position:0% +so you see the pocket goes in this +direction you want to just drop the + + align:start position:0% +direction you want to just drop the + + + align:start position:0% +direction you want to just drop the +back talking a + + align:start position:0% +back talking a + + + align:start position:0% +back talking a +camera and to clamp it you just push + + align:start position:0% +camera and to clamp it you just push + + + align:start position:0% +camera and to clamp it you just push +again + + align:start position:0% +again + + + align:start position:0% +again +idea and you can actually you know get + + align:start position:0% +idea and you can actually you know get + + + align:start position:0% +idea and you can actually you know get +it so that the field of view is is + + align:start position:0% +it so that the field of view is is + + + align:start position:0% +it so that the field of view is is +pretty small and so I think that I'll + + align:start position:0% +pretty small and so I think that I'll + + + align:start position:0% +pretty small and so I think that I'll +keep it's not exactly what people + + align:start position:0% +keep it's not exactly what people + + + align:start position:0% +keep it's not exactly what people +not + + align:start position:0% + + + + align:start position:0% + +easic to see + + align:start position:0% +easic to see + + + align:start position:0% +easic to see +the yeah but you know + + align:start position:0% +the yeah but you know + + + align:start position:0% +the yeah but you know +what I once you do it five + + align:start position:0% +what I once you do it five + + + align:start position:0% +what I once you do it five +times for me to in + + align:start position:0% +times for me to in + + + align:start position:0% +times for me to in +so he's the he is our uh he he's the lab + + align:start position:0% +so he's the he is our uh he he's the lab + + + align:start position:0% +so he's the he is our uh he he's the lab +manager for DM for + + align:start position:0% + + + + align:start position:0% + +materials so anyway when we were + + align:start position:0% +materials so anyway when we were + + + align:start position:0% +materials so anyway when we were +developing forc put we + + align:start position:0% +developing forc put we + + + align:start position:0% +developing forc put we +got firewire ceras direct the of all our + + align:start position:0% +got firewire ceras direct the of all our + + + align:start position:0% +got firewire ceras direct the of all our +mic and they work really well + + align:start position:0% +mic and they work really well + + + align:start position:0% +mic and they work really well +for so you know when he's used to tring + + align:start position:0% +for so you know when he's used to tring + + + align:start position:0% +for so you know when he's used to tring +things + + align:start position:0% +things + + + align:start position:0% +things +outc yeah + + align:start position:0% + + + + align:start position:0% + +so so + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +so we can't + + align:start position:0% + + + + align:start position:0% + +adjust you want to put f + + align:start position:0% +adjust you want to put f + + + align:start position:0% +adjust you want to put f +[Music] + + align:start position:0% + + + + align:start position:0% + +use fingers to take it out or tweezers + + align:start position:0% +use fingers to take it out or tweezers + + + align:start position:0% +use fingers to take it out or tweezers +um tweezers are best if you want to use + + align:start position:0% +um tweezers are best if you want to use + + + align:start position:0% +um tweezers are best if you want to use +your fingers I'd recommend the glove + + align:start position:0% +your fingers I'd recommend the glove + + + align:start position:0% +your fingers I'd recommend the glove +just so you don't + + align:start position:0% + + + + align:start position:0% + +use want to go + + align:start position:0% + + + + align:start position:0% + +do you the + + align:start position:0% +do you the + + + align:start position:0% +do you the +twers um we have another + + align:start position:0% +twers um we have another + + + align:start position:0% +twers um we have another +pair blue or + + align:start position:0% +pair blue or + + + align:start position:0% +pair blue or +red that's probably red go on the left + + align:start position:0% +red that's probably red go on the left + + + align:start position:0% +red that's probably red go on the left +side + + align:start position:0% + + + + align:start position:0% + +there so we'll take so you said the + + align:start position:0% +there so we'll take so you said the + + + align:start position:0% +there so we'll take so you said the +softer ones it doesn't matteress like + + align:start position:0% +softer ones it doesn't matteress like + + + align:start position:0% +softer ones it doesn't matteress like +it's the hard ones first yeah you want + + align:start position:0% +it's the hard ones first yeah you want + + + align:start position:0% +it's the hard ones first yeah you want +the hard ones first to give your your + + align:start position:0% +the hard ones first to give your your + + + align:start position:0% +the hard ones first to give your your +calibration measurement basically and + + align:start position:0% + + + + align:start position:0% + +so we should try before we adjust the + + align:start position:0% +so we should try before we adjust the + + + align:start position:0% +so we should try before we adjust the +focus to position the + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +spot nearest tip is the best is the best + + align:start position:0% +spot nearest tip is the best is the best + + + align:start position:0% +spot nearest tip is the best is the best +get + + align:start position:0% + + + + align:start position:0% + +all right so now we have to adjust + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +the keep all of + + align:start position:0% + + + + align:start position:0% + +these Max do you do you keep all four + + align:start position:0% +these Max do you do you keep all four + + + align:start position:0% +these Max do you do you keep all four +screws set screws on the oh no I + + align:start position:0% +screws set screws on the oh no I + + + align:start position:0% +screws set screws on the oh no I +typically just Tien one so and this SC + + align:start position:0% +typically just Tien one so and this SC + + + align:start position:0% +typically just Tien one so and this SC +might be on on the other side there we + + align:start position:0% +might be on on the other side there we + + + align:start position:0% +might be on on the other side there we +go this one yeah that's better one + + align:start position:0% +go this one yeah that's better one + + + align:start position:0% +go this one yeah that's better one +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +sh + + align:start position:0% + + + + align:start position:0% + +okay oh no I don't think that was okay + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% +that's + + + align:start position:0% +that's +[Music] + + align:start position:0% + + + + align:start position:0% + +right and + + align:start position:0% +right and + + + align:start position:0% +right and +then + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +CL do position + + align:start position:0% +CL do position + + + align:start position:0% +CL do position +it to see if you're right position it + + align:start position:0% +it to see if you're right position it + + + align:start position:0% +it to see if you're right position it +again + + align:start position:0% + + + + align:start position:0% + +moving side to + + align:start position:0% +moving side to + + + align:start position:0% +moving side to +[Music] + + align:start position:0% + + + + align:start position:0% + +side right way + + align:start position:0% +side right way + + + align:start position:0% +side right way +now oh + + align:start position:0% +now oh + + + align:start position:0% +now oh +nice good little lower we + + align:start position:0% +nice good little lower we + + + align:start position:0% +nice good little lower we +[Music] + + align:start position:0% + + + + align:start position:0% + +good oh I think we went too far + + align:start position:0% + + + + align:start position:0% + +finally that's how you make an + + align:start position:0% +finally that's how you make an + + + align:start position:0% +finally that's how you make an +adjustment all + + align:start position:0% +adjustment all + + + align:start position:0% +adjustment all +right now your challenge is to tighten + + align:start position:0% +right now your challenge is to tighten + + + align:start position:0% +right now your challenge is to tighten +that set screw without moving + + align:start position:0% + + + + align:start position:0% + +anything the challeng is to not even to + + align:start position:0% +anything the challeng is to not even to + + + align:start position:0% +anything the challeng is to not even to +not move anything even before it okay is + + align:start position:0% +not move anything even before it okay is + + + align:start position:0% +not move anything even before it okay is +this good now yeah that looks great all + + align:start position:0% +this good now yeah that looks great all + + + align:start position:0% +this good now yeah that looks great all +right so + + align:start position:0% +right so + + + align:start position:0% +right so +[Music] + + align:start position:0% + + + + align:start position:0% + +here you can check it once you think you + + align:start position:0% +here you can check it once you think you + + + align:start position:0% +here you can check it once you think you +the tight + + align:start position:0% +the tight + + + align:start position:0% +the tight +okay beautiful all + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +nice just make sure we've got it on + + align:start position:0% +nice just make sure we've got it on + + + align:start position:0% +nice just make sure we've got it on +the bright + + align:start position:0% +the bright + + + align:start position:0% +the bright +one + + align:start position:0% +one + + + align:start position:0% +one +do then the light go to the right to the + + align:start position:0% +do then the light go to the right to the + + + align:start position:0% +do then the light go to the right to the +where we fell off just that we fell off + + align:start position:0% +where we fell off just that we fell off + + + align:start position:0% +where we fell off just that we fell off +the end + + align:start position:0% +the end + + + align:start position:0% +the end +again yeah I didn't move that one so + + align:start position:0% +again yeah I didn't move that one so + + + align:start position:0% +again yeah I didn't move that one so +okay that's right right okay + + align:start position:0% +okay that's right right okay + + + align:start position:0% +okay that's right right okay +nice okay so yeah let's run oh uh let's + + align:start position:0% +nice okay so yeah let's run oh uh let's + + + align:start position:0% +nice okay so yeah let's run oh uh let's +run the software and get the sample in + + align:start position:0% +run the software and get the sample in + + + align:start position:0% +run the software and get the sample in +contact yes + + align:start position:0% + + + + align:start position:0% + +okay we have miles to go + + align:start position:0% + + + + align:start position:0% + +what's + + align:start position:0% +what's + + + align:start position:0% +what's +upfor + + align:start position:0% + + + + align:start position:0% + +mod + + align:start position:0% +mod + + + align:start position:0% +mod +okay all right so start + + align:start position:0% + + + + align:start position:0% + +sure so I don't think we're that close + + align:start position:0% +sure so I don't think we're that close + + + align:start position:0% +sure so I don't think we're that close +yet but you see I've got the disc up + + align:start position:0% +yet but you see I've got the disc up + + + align:start position:0% +yet but you see I've got the disc up +inside the + + align:start position:0% +inside the + + + align:start position:0% +inside the +uhhuh so I don't know if that's too + + align:start position:0% +uhhuh so I don't know if that's too + + + align:start position:0% +uhhuh so I don't know if that's too +cautious as a place to start using the + + align:start position:0% +cautious as a place to start using the + + + align:start position:0% +cautious as a place to start using the +joystick but it I it takes a long time + + align:start position:0% +joystick but it I it takes a long time + + + align:start position:0% +joystick but it I it takes a long time +it's worth getting it it's worth getting + + align:start position:0% +it's worth getting it it's worth getting + + + align:start position:0% +it's worth getting it it's worth getting +it a little closer + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +much + + align:start position:0% + + + + align:start position:0% + +I'm not seeing the reflection of the C + + align:start position:0% +I'm not seeing the reflection of the C + + + align:start position:0% +I'm not seeing the reflection of the C +no you can't tell what you you can see + + align:start position:0% +no you can't tell what you you can see + + + align:start position:0% +no you can't tell what you you can see +the tip move but this with the short one + + align:start position:0% +the tip move but this with the short one + + + align:start position:0% +the tip move but this with the short one +actually you might can be pretty + + align:start position:0% +actually you might can be pretty + + + align:start position:0% +actually you might can be pretty +hard all right so let's go to the see + + align:start position:0% +hard all right so let's go to the see + + + align:start position:0% +hard all right so let's go to the see +under cautious + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah you can also see it on here when + + align:start position:0% +yeah you can also see it on here when + + + align:start position:0% +yeah you can also see it on here when +you hit you can see the oh yeah see the + + align:start position:0% +you hit you can see the oh yeah see the + + + align:start position:0% +you hit you can see the oh yeah see the +spots would here + + align:start position:0% + + + + align:start position:0% + +you can I + + align:start position:0% +you can I + + + align:start position:0% +you can I +mean now I think I can actually see what + + align:start position:0% +mean now I think I can actually see what + + + align:start position:0% +mean now I think I can actually see what +the reflection is + + align:start position:0% +the reflection is + + + align:start position:0% +the reflection is +okay that's the hardest part just + + align:start position:0% +okay that's the hardest part just + + + align:start position:0% +okay that's the hardest part just +getting your bearings on how close are + + align:start position:0% +getting your bearings on how close are + + + align:start position:0% +getting your bearings on how close are +you yeah now + + align:start position:0% + + + + align:start position:0% + +I no I know I'm close + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I'm not that close am I well you can + + align:start position:0% +I'm not that close am I well you can + + + align:start position:0% +I'm not that close am I well you can +also go I mean you can crank it fast you + + align:start position:0% +also go I mean you can crank it fast you + + + align:start position:0% +also go I mean you can crank it fast you +can go faster too on the joystick you to + + align:start position:0% +can go faster too on the joystick you to + + + align:start position:0% +can go faster too on the joystick you to +go + + align:start position:0% + + + + align:start position:0% + +go that yeah you're going pretty slow + + align:start position:0% + + + + align:start position:0% + +before Oh I saw + + align:start position:0% + + + + align:start position:0% + +something it's not it + + align:start position:0% +something it's not it + + + align:start position:0% +something it's not it +Shi yeah something + + align:start position:0% +Shi yeah something + + + align:start position:0% +Shi yeah something +[Music] + + align:start position:0% + + + + align:start position:0% + +this bringing into contact is a delicate + + align:start position:0% +this bringing into contact is a delicate + + + align:start position:0% +this bringing into contact is a delicate +musn't + + align:start position:0% + + + + align:start position:0% + +M good is to we the uh machine parts we + + align:start position:0% +M good is to we the uh machine parts we + + + align:start position:0% +M good is to we the uh machine parts we +need for our sces as well + + align:start position:0% + + + + align:start position:0% + +I can see why the froes get brok it now + + align:start position:0% +I can see why the froes get brok it now + + + align:start position:0% +I can see why the froes get brok it now +yeah cuz you probably get impatient look + + align:start position:0% +yeah cuz you probably get impatient look + + + align:start position:0% +yeah cuz you probably get impatient look +see I lost my + + align:start position:0% +see I lost my + + + align:start position:0% +see I lost my +defraction the + + align:start position:0% +defraction the + + + align:start position:0% +defraction the +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +breako see it loed off + + align:start position:0% +breako see it loed off + + + align:start position:0% +breako see it loed off +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +how's that possible I'm not sure what we + + align:start position:0% + + + + align:start position:0% + +did all + + align:start position:0% + + + + align:start position:0% + +right well should I should I + + align:start position:0% + + + + align:start position:0% + +not you don't think I actually I don't + + align:start position:0% +not you don't think I actually I don't + + + align:start position:0% +not you don't think I actually I don't +know see the thing is now I'm moving + + align:start position:0% +know see the thing is now I'm moving + + + align:start position:0% +know see the thing is now I'm moving +down and I got my defraction spot back + + align:start position:0% +down and I got my defraction spot back + + + align:start position:0% +down and I got my defraction spot back +oh so maybe we did hit it long ago yeah + + align:start position:0% +oh so maybe we did hit it long ago yeah + + + align:start position:0% +oh so maybe we did hit it long ago yeah +but maybe we just don't have look at + + align:start position:0% +but maybe we just don't have look at + + + align:start position:0% +but maybe we just don't have look at +that oh there we go oh it looks like + + align:start position:0% +that oh there we go oh it looks like + + + align:start position:0% +that oh there we go oh it looks like +we're + + align:start position:0% +we're + + + align:start position:0% +we're +hitting so maybe I missed it was just + + align:start position:0% +hitting so maybe I missed it was just + + + align:start position:0% +hitting so maybe I missed it was just +really + + align:start position:0% +really + + + align:start position:0% +really +done yeah I think that's probably right + + align:start position:0% +done yeah I think that's probably right + + + align:start position:0% +done yeah I think that's probably right +okay but I think we didn't break it + + align:start position:0% +okay but I think we didn't break it + + + align:start position:0% +okay but I think we didn't break it +yet hard + + align:start position:0% +yet hard + + + align:start position:0% +yet hard +to no + + align:start position:0% + + + + align:start position:0% + +look how about that that's no joystick + + align:start position:0% +look how about that that's no joystick + + + align:start position:0% +look how about that that's no joystick +Conta + + align:start position:0% +Conta + + + align:start position:0% +Conta +all + + align:start position:0% +all + + + align:start position:0% +all +right you might want to back + + align:start position:0% + + + + align:start position:0% + +off that's almost exactly how I did it + + align:start position:0% +off that's almost exactly how I did it + + + align:start position:0% +off that's almost exactly how I did it +last time is I went and it was actually + + align:start position:0% +last time is I went and it was actually + + + align:start position:0% +last time is I went and it was actually +in very good contact and then I backed + + align:start position:0% +in very good contact and then I backed + + + align:start position:0% +in very good contact and then I backed +off yeah that's yeah another reason why + + align:start position:0% +off yeah that's yeah another reason why + + + align:start position:0% +off yeah that's yeah another reason why +you won't get good images with the hard + + align:start position:0% +you won't get good images with the hard + + + align:start position:0% +you won't get good images with the hard +Conta yeah so out of cont + + align:start position:0% + + + + align:start position:0% + +cont okay so now as far as the biasing + + align:start position:0% +cont okay so now as far as the biasing + + + align:start position:0% +cont okay so now as far as the biasing +right now we're down at the bottom of + + align:start position:0% +right now we're down at the bottom of + + + align:start position:0% +right now we're down at the bottom of +the way versus yeah the + + align:start position:0% +the way versus yeah the + + + align:start position:0% +the way versus yeah the +bottom it's not a big it's not really a + + align:start position:0% +bottom it's not a big it's not really a + + + align:start position:0% +bottom it's not a big it's not really a +big win is it because as long as you + + align:start position:0% +big win is it because as long as you + + + align:start position:0% +big win is it because as long as you +know you're as long as you come from + + align:start position:0% +know you're as long as you come from + + + align:start position:0% +know you're as long as you come from +place the same place the same place yeah + + align:start position:0% +place the same place the same place yeah + + + align:start position:0% +place the same place the same place yeah +yeah maybe that's maybe that's why he + + align:start position:0% +yeah maybe that's maybe that's why he + + + align:start position:0% +yeah maybe that's maybe that's why he +suggests the center it's easy to figure + + align:start position:0% +suggests the center it's easy to figure + + + align:start position:0% +suggests the center it's easy to figure +out where the center is + + align:start position:0% + + + + align:start position:0% + +then I was thinking it would be easier + + align:start position:0% +then I was thinking it would be easier + + + align:start position:0% +then I was thinking it would be easier +to fool yourself about what CER was + + align:start position:0% + + + + align:start position:0% + +too kind weird + + align:start position:0% +too kind weird + + + align:start position:0% +too kind weird +[Music] + + align:start position:0% + + + + align:start position:0% + +so just going to back out of contact + + align:start position:0% +so just going to back out of contact + + + align:start position:0% +so just going to back out of contact +okay so now I'm not in + + align:start position:0% + + + + align:start position:0% + +contact a + + align:start position:0% +contact a + + + align:start position:0% +contact a +little get to contact yeah + + align:start position:0% + + + + align:start position:0% + +so is what's happening + + align:start position:0% + + + + align:start position:0% + +there top of the W it's hard when to + + align:start position:0% +there top of the W it's hard when to + + + align:start position:0% +there top of the W it's hard when to +when to trace the traes are the same + + align:start position:0% +when to trace the traes are the same + + + align:start position:0% +when to trace the traes are the same +color + + align:start position:0% +color + + + align:start position:0% +color +uh so I just move the th closer so we + + align:start position:0% +uh so I just move the th closer so we + + + align:start position:0% +uh so I just move the th closer so we +can get some more uh yeah hers I think + + align:start position:0% +can get some more uh yeah hers I think + + + align:start position:0% +can get some more uh yeah hers I think +so + + align:start position:0% + + + + align:start position:0% + +also you know honestly if you look at + + align:start position:0% +also you know honestly if you look at + + + align:start position:0% +also you know honestly if you look at +the detector I'm not sure we're + + align:start position:0% +the detector I'm not sure we're + + + align:start position:0% +the detector I'm not sure we're +fully capturing the + + align:start position:0% + + + + align:start position:0% + +making me much happier + + align:start position:0% +making me much happier + + + align:start position:0% +making me much happier +though all right well at least we + + align:start position:0% +though all right well at least we + + + align:start position:0% +though all right well at least we +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +now so + + align:start position:0% +now so + + + align:start position:0% +now so +now see + + align:start position:0% +now see + + + align:start position:0% +now see +oh we want to make sure + + align:start position:0% +oh we want to make sure + + + align:start position:0% +oh we want to make sure +we're do we're not on high gain right + + align:start position:0% +we're do we're not on high gain right + + + align:start position:0% +we're do we're not on high gain right +yeah what are we on 100 divide by 100 + + align:start position:0% + + + + align:start position:0% + +right why don't we ground this for a + + align:start position:0% + + + + align:start position:0% + +second + + align:start position:0% + + + + align:start position:0% + +but there we go what did you do uh if we + + align:start position:0% +but there we go what did you do uh if we + + + align:start position:0% +but there we go what did you do uh if we +were grounding one oh yeah + + align:start position:0% +were grounding one oh yeah + + + align:start position:0% +were grounding one oh yeah +so now put that back in the middle there + + align:start position:0% +so now put that back in the middle there + + + align:start position:0% +so now put that back in the middle there +we + + align:start position:0% + + + + align:start position:0% + +go out of contact right now + + align:start position:0% +go out of contact right now + + + align:start position:0% +go out of contact right now +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay slightly in Conta + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah you guys we didn't have the the + + align:start position:0% +yeah you guys we didn't have the the + + + align:start position:0% +yeah you guys we didn't have the the +sauce proper sitting + + align:start position:0% + + + + align:start position:0% + +on oh no same thing as last is this a + + align:start position:0% +on oh no same thing as last is this a + + + align:start position:0% +on oh no same thing as last is this a +bad clip is + + align:start position:0% +bad clip is + + + align:start position:0% +bad clip is +that this one of the clips is a little + + align:start position:0% +that this one of the clips is a little + + + align:start position:0% +that this one of the clips is a little +weak + + align:start position:0% +weak + + + align:start position:0% +weak +right a little bit well we can + + align:start position:0% + + + + align:start position:0% + +talk a + + align:start position:0% +talk a + + + align:start position:0% +talk a +little go + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% + + + + align:start position:0% + +do + + align:start position:0% + + + + align:start position:0% + +yeah there we + + align:start position:0% + + + + align:start position:0% + +go + + align:start position:0% +go + + + align:start position:0% +go +wide yeah I'd expect to see more + + align:start position:0% +wide yeah I'd expect to see more + + + align:start position:0% +wide yeah I'd expect to see more +yeah so that's what + + align:start position:0% +yeah so that's what + + + align:start position:0% +yeah so that's what +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +we that's + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +good actually + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +those parts are bad for us they + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% +what + + + align:start position:0% +what +[Music] + + align:start position:0% + + + + align:start position:0% + +you so are you trying to focus on the + + align:start position:0% +you so are you trying to focus on the + + + align:start position:0% +you so are you trying to focus on the +closer one are you trying to focus on + + align:start position:0% +closer one are you trying to focus on + + + align:start position:0% +closer one are you trying to focus on +The Closer account + + align:start position:0% +The Closer account + + + align:start position:0% +The Closer account +La first of all + + align:start position:0% +La first of all + + + align:start position:0% +La first of all +I don't know don't remember like which + + align:start position:0% + + + + align:start position:0% + +one yeah just + + align:start position:0% + + + + align:start position:0% + +does it look like that one of them might + + align:start position:0% +does it look like that one of them might + + + align:start position:0% +does it look like that one of them might +be + + align:start position:0% + + + + align:start position:0% + +broken yeah the tips I think the poster + + align:start position:0% +broken yeah the tips I think the poster + + + align:start position:0% +broken yeah the tips I think the poster +one is + + align:start position:0% + + + + align:start position:0% + +broken there we + + align:start position:0% +broken there we + + + align:start position:0% +broken there we +go yeah this is what we were seeed not + + align:start position:0% +go yeah this is what we were seeed not + + + align:start position:0% +go yeah this is what we were seeed not +quite this St that + + align:start position:0% + + + + align:start position:0% + +the Ripple in the flat part yeah that + + align:start position:0% +the Ripple in the flat part yeah that + + + align:start position:0% +the Ripple in the flat part yeah that +that there's some + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +bizarre count to much but the basically + + align:start position:0% +bizarre count to much but the basically + + + align:start position:0% +bizarre count to much but the basically +be able to overlap the three different + + align:start position:0% +be able to overlap the three different + + + align:start position:0% +be able to overlap the three different +measurements that you make and then + + align:start position:0% +measurements that you make and then + + + align:start position:0% +measurements that you make and then +compare compare your stage motion + + align:start position:0% + + + + align:start position:0% + +with + + align:start position:0% +with + + + align:start position:0% +with +exct yeah because you can see that okay + + align:start position:0% +exct yeah because you can see that okay + + + align:start position:0% +exct yeah because you can see that okay +here the can is coming in contact well + + align:start position:0% +here the can is coming in contact well + + + align:start position:0% +here the can is coming in contact well +no it's not at all but + + align:start position:0% +no it's not at all but + + + align:start position:0% +no it's not at all but +um it's it's the place where it's + + align:start position:0% +um it's it's the place where it's + + + align:start position:0% +um it's it's the place where it's +clearest where the can comes in contact + + align:start position:0% +clearest where the can comes in contact + + + align:start position:0% +clearest where the can comes in contact +with the surface okay that Mak sense um + + align:start position:0% +with the surface okay that Mak sense um + + + align:start position:0% +with the surface okay that Mak sense um +you might also + + align:start position:0% + + + + align:start position:0% + +check yeah let's see if the other + + align:start position:0% +check yeah let's see if the other + + + align:start position:0% +check yeah let's see if the other +grading is a little bit happier + + align:start position:0% + + + + align:start position:0% + +did you think maybe theor was bit angle + + align:start position:0% +did you think maybe theor was bit angle + + + align:start position:0% +did you think maybe theor was bit angle +yeah it was a little bit angled so you + + align:start position:0% +yeah it was a little bit angled so you + + + align:start position:0% +yeah it was a little bit angled so you +can probably improve some more tiny + + align:start position:0% +can probably improve some more tiny + + + align:start position:0% +can probably improve some more tiny +bit Yeah you see how well + + align:start position:0% +bit Yeah you see how well + + + align:start position:0% +bit Yeah you see how well +[Music] + + align:start position:0% + + + + align:start position:0% + +that's a better shape + + align:start position:0% + + + + align:start position:0% + +so this is because you're on the other + + align:start position:0% +so this is because you're on the other + + + align:start position:0% +so this is because you're on the other +Fringe now or because you adjusted the + + align:start position:0% +Fringe now or because you adjusted the + + + align:start position:0% +Fringe now or because you adjusted the +protector um it's part well so i' I've + + align:start position:0% +protector um it's part well so i' I've + + + align:start position:0% +protector um it's part well so i' I've +switched to the other set of fingers + + align:start position:0% +switched to the other set of fingers + + + align:start position:0% +switched to the other set of fingers +sorry that's they are a little bit + + align:start position:0% +sorry that's they are a little bit + + + align:start position:0% +sorry that's they are a little bit +better it looks + + align:start position:0% + + + + align:start position:0% + +like I also + + align:start position:0% +like I also + + + align:start position:0% +like I also +uh yeah I also slightly like improved + + align:start position:0% +uh yeah I also slightly like improved + + + align:start position:0% +uh yeah I also slightly like improved +the detector + + align:start position:0% +the detector + + + align:start position:0% +the detector +alignment so now the shape looks pretty + + align:start position:0% +alignment so now the shape looks pretty + + + align:start position:0% +alignment so now the shape looks pretty +decent the the the problem here that I + + align:start position:0% +decent the the the problem here that I + + + align:start position:0% +decent the the the problem here that I +anticipate + + align:start position:0% +anticipate + + + align:start position:0% +anticipate +is oh here we are yeah now we're getting + + align:start position:0% +is oh here we are yeah now we're getting + + + align:start position:0% +is oh here we are yeah now we're getting +a full + + align:start position:0% +a full + + + align:start position:0% +a full +Fringe + + align:start position:0% +Fringe + + + align:start position:0% +Fringe +okay so that's actually that's + + align:start position:0% +okay so that's actually that's + + + align:start position:0% +okay so that's actually that's +nice + + align:start position:0% +nice + + + align:start position:0% +nice +um yeah so now you have a very nice + + align:start position:0% +um yeah so now you have a very nice + + + align:start position:0% +um yeah so now you have a very nice +sinos soy that you can get a full Fringe + + align:start position:0% +sinos soy that you can get a full Fringe + + + align:start position:0% +sinos soy that you can get a full Fringe +of this in contact portion so I would uh + + align:start position:0% +of this in contact portion so I would uh + + + align:start position:0% +of this in contact portion so I would uh +I would actually record that okay and + + align:start position:0% +I would actually record that okay and + + + align:start position:0% +I would actually record that okay and +keep that as a reference + + align:start position:0% + + + + align:start position:0% + +yeah I think you can ALS sometimes you + + align:start position:0% +yeah I think you can ALS sometimes you + + + align:start position:0% +yeah I think you can ALS sometimes you +can use the retraction part also + + align:start position:0% +can use the retraction part also + + + align:start position:0% +can use the retraction part also +sometime + + align:start position:0% + + + + align:start position:0% + +it's it helps you interpret whether this + + align:start position:0% +it's it helps you interpret whether this + + + align:start position:0% +it's it helps you interpret whether this +is giving a good day that okay so um to + + align:start position:0% +is giving a good day that okay so um to + + + align:start position:0% +is giving a good day that okay so um to +actually record it I often times will do + + align:start position:0% +actually record it I often times will do + + + align:start position:0% +actually record it I often times will do +a slower Trace like at a half a Hertz so + + align:start position:0% +a slower Trace like at a half a Hertz so + + + align:start position:0% +a slower Trace like at a half a Hertz so +that so that there's no it minimizes + + align:start position:0% +that so that there's no it minimizes + + + align:start position:0% +that so that there's no it minimizes +hysteresis a little + + align:start position:0% +hysteresis a little + + + align:start position:0% +hysteresis a little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +um we should make recorded yeah you can + + align:start position:0% +um we should make recorded yeah you can + + + align:start position:0% +um we should make recorded yeah you can +actually you can you can save a force + + align:start position:0% +actually you can you can save a force + + + align:start position:0% +actually you can you can save a force +curve when it's not + + align:start position:0% +curve when it's not + + + align:start position:0% +curve when it's not +scanning um whatever you see on the + + align:start position:0% +scanning um whatever you see on the + + + align:start position:0% +scanning um whatever you see on the +screen is what it put in the + + align:start position:0% + + + + align:start position:0% + +file yeah yeah + + align:start position:0% +file yeah yeah + + + align:start position:0% +file yeah yeah +oh it's it's a little there's more + + align:start position:0% +oh it's it's a little there's more + + + align:start position:0% +oh it's it's a little there's more +points + + align:start position:0% +points + + + align:start position:0% +points +[Music] + + align:start position:0% + + + + align:start position:0% + +basically good yeah just + + align:start position:0% + + + + align:start position:0% + +say it's badly or it wasn't I think it + + align:start position:0% +say it's badly or it wasn't I think it + + + align:start position:0% +say it's badly or it wasn't I think it +was flipped yeah I think so couldn't + + align:start position:0% +was flipped yeah I think so couldn't + + + align:start position:0% +was flipped yeah I think so couldn't +[Music] + + align:start position:0% + + + + align:start position:0% + +see shall I start taking the sample out + + align:start position:0% +see shall I start taking the sample out + + + align:start position:0% +see shall I start taking the sample out +[Music] + + align:start position:0% + + + + align:start position:0% + +sure yeah that looks + + align:start position:0% +sure yeah that looks + + + align:start position:0% +sure yeah that looks +good oh well did you reverse + + align:start position:0% +good oh well did you reverse + + + align:start position:0% +good oh well did you reverse +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +it yeah so now what you've got you + + align:start position:0% +it yeah so now what you've got you + + + align:start position:0% +it yeah so now what you've got you +actually got these levers that are not + + align:start position:0% + + + + align:start position:0% + +particular yeah + + align:start position:0% +particular yeah + + + align:start position:0% +particular yeah +which they might be now dead in the + + align:start position:0% +which they might be now dead in the + + + align:start position:0% +which they might be now dead in the +background but that's + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +mic yeah let's just change to + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +mhm + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +simp okay thank you let's give it a shot + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay those compressed a + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +why isn't it saving + + align:start position:0% +why isn't it saving + + + align:start position:0% +why isn't it saving +yeah is there no file being + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +created say that again I the full + + align:start position:0% +created say that again I the full + + + align:start position:0% +created say that again I the full +name + + align:start position:0% +name + + + align:start position:0% +name +uh you got to make sure there's a full + + align:start position:0% +uh you got to make sure there's a full + + + align:start position:0% +uh you got to make sure there's a full +[Music] + + align:start position:0% + + + + align:start position:0% + +path oh + + align:start position:0% +path oh + + + align:start position:0% +path oh +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +what + + align:start position:0% +what + + + align:start position:0% +what +the text is + + align:start position:0% + + + + align:start position:0% + +good it just saves an uh + + align:start position:0% + + + + align:start position:0% + +text do you export this to the the M lab + + align:start position:0% +text do you export this to the the M lab + + + align:start position:0% +text do you export this to the the M lab +desktop you can just load it as um it's + + align:start position:0% +desktop you can just load it as um it's + + + align:start position:0% +desktop you can just load it as um it's +should be a two colum file of data okay + + align:start position:0% +should be a two colum file of data okay + + + align:start position:0% +should be a two colum file of data okay +you should be able to just plot X versus + + align:start position:0% + + + + align:start position:0% + +y sorry + + align:start position:0% +y sorry + + + align:start position:0% +y sorry +the gr SLE that should be + + align:start position:0% +the gr SLE that should be + + + align:start position:0% +the gr SLE that should be +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah and that'll help you position it + + align:start position:0% +yeah and that'll help you position it + + + align:start position:0% +yeah and that'll help you position it +and then you can load it back down + + align:start position:0% + + + + align:start position:0% + +yep it's + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +good we + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I have to do you have to do one + + align:start position:0% +I have to do you have to do one + + + align:start position:0% +I have to do you have to do one +vers this is the driving + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah that + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +uh oh uh there that's better + + align:start position:0% +uh oh uh there that's better + + + align:start position:0% +uh oh uh there that's better +[Music] + + align:start position:0% + + + + align:start position:0% + +uh just want + + align:start position:0% +uh just want + + + align:start position:0% +uh just want +open + + align:start position:0% + + + + align:start position:0% + +seal all right um oh and what yeah what + + align:start position:0% +seal all right um oh and what yeah what + + + align:start position:0% +seal all right um oh and what yeah what +actually the best thing to do is open + + align:start position:0% +actually the best thing to do is open + + + align:start position:0% +actually the best thing to do is open +yeah one thing I in the bolab is I just + + align:start position:0% +yeah one thing I in the bolab is I just + + + align:start position:0% +yeah one thing I in the bolab is I just +had all those variables like that appear + + align:start position:0% +had all those variables like that appear + + + align:start position:0% +had all those variables like that appear +in the workspace so you didn't have to + + align:start position:0% +in the workspace so you didn't have to + + + align:start position:0% +in the workspace so you didn't have to +export them and reort them oh should you + + align:start position:0% +export them and reort them oh should you + + + align:start position:0% +export them and reort them oh should you +click on + + align:start position:0% + + + + align:start position:0% + +workpace oh yeah so you got you got to + + align:start position:0% +workpace oh yeah so you got you got to + + + align:start position:0% +workpace oh yeah so you got you got to +you actually have to um they're in the + + align:start position:0% +you actually have to um they're in the + + + align:start position:0% +you actually have to um they're in the +name space of the that GOI application + + align:start position:0% +name space of the that GOI application + + + align:start position:0% +name space of the that GOI application +there's a + + align:start position:0% +there's a + + + align:start position:0% +there's a +command uh there's a command that + + align:start position:0% +command uh there's a command that + + + align:start position:0% +command uh there's a command that +exports it to the oh really I don't + + align:start position:0% +exports it to the oh really I don't + + + align:start position:0% +exports it to the oh really I don't +remember the name of it off off my head + + align:start position:0% +remember the name of it off off my head + + + align:start position:0% +remember the name of it off off my head +but there's a some stupid the long list + + align:start position:0% +but there's a some stupid the long list + + + align:start position:0% +but there's a some stupid the long list +of stupid that lb + + align:start position:0% +of stupid that lb + + + align:start position:0% +of stupid that lb +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +con there's uh there's there's one and + + align:start position:0% +con there's uh there's there's one and + + + align:start position:0% +con there's uh there's there's one and +so what right what + + align:start position:0% + + + + align:start position:0% + +I see + + align:start position:0% +I see + + + align:start position:0% +I see +where's still starting + + align:start position:0% +where's still starting + + + align:start position:0% +where's still starting +can I going be trying to put it in the + + align:start position:0% +can I going be trying to put it in the + + + align:start position:0% +can I going be trying to put it in the +same window or + + align:start position:0% +same window or + + + align:start position:0% +same window or +something thatb is really a pathetic + + align:start position:0% +something thatb is really a pathetic + + + align:start position:0% +something thatb is really a pathetic +program isn't it all right hey hey no I + + align:start position:0% +program isn't it all right hey hey no I + + + align:start position:0% +program isn't it all right hey hey no I +didn't say your stuff I said that + + align:start position:0% +didn't say your stuff I said that + + + align:start position:0% +didn't say your stuff I said that +notel that's + + align:start position:0% +notel that's + + + align:start position:0% +notel that's +right all right all right uh are we + + align:start position:0% +right all right all right uh are we + + + align:start position:0% +right all right all right uh are we +ready yes all right so we're + + align:start position:0% +ready yes all right so we're + + + align:start position:0% +ready yes all right so we're +do don't put the part where I said bat + + align:start position:0% +do don't put the part where I said bat + + + align:start position:0% +do don't put the part where I said bat +loveb is pathetic up all + + align:start position:0% +loveb is pathetic up all + + + align:start position:0% +loveb is pathetic up all +right all + + align:start position:0% + + + + align:start position:0% + +right it's a soft sample it's + + align:start position:0% +right it's a soft sample it's + + + align:start position:0% +right it's a soft sample it's +noted pretty sure I already touched it + + align:start position:0% +noted pretty sure I already touched it + + + align:start position:0% +noted pretty sure I already touched it +oh all right and so I can + + align:start position:0% +oh all right and so I can + + + align:start position:0% +oh all right and so I can +[Music] + + align:start position:0% + + + + align:start position:0% + +there we + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +are so I'm just backing away from the + + align:start position:0% +are so I'm just backing away from the + + + align:start position:0% +are so I'm just backing away from the +surface now + + align:start position:0% +surface now + + + align:start position:0% +surface now +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +contact out of + + align:start position:0% +contact out of + + + align:start position:0% +contact out of +contact just + + align:start position:0% + + + + align:start position:0% + +contact contact all + + align:start position:0% +contact contact all + + + align:start position:0% +contact contact all +right yay all right let me uh maybe back + + align:start position:0% +right yay all right let me uh maybe back + + + align:start position:0% +right yay all right let me uh maybe back +off just a few + + align:start position:0% +off just a few + + + align:start position:0% +off just a few +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +clicks uh + + align:start position:0% +clicks uh + + + align:start position:0% +clicks uh +yeah perfect all right so let's slow + + align:start position:0% +yeah perfect all right so let's slow + + + align:start position:0% +yeah perfect all right so let's slow +this down again + + align:start position:0% + + + + align:start position:0% + +I don't see just one + + align:start position:0% + + + + align:start position:0% + +spot oh this is cool you should uh can + + align:start position:0% +spot oh this is cool you should uh can + + + align:start position:0% +spot oh this is cool you should uh can +you run that again because since you're + + align:start position:0% +you run that again because since you're + + + align:start position:0% +you run that again because since you're +scanning so much more slowly now you can + + align:start position:0% +scanning so much more slowly now you can + + + align:start position:0% +scanning so much more slowly now you can +see the whole Fringe up and down + + align:start position:0% + + + + align:start position:0% + +oh yeah that's really + + align:start position:0% +oh yeah that's really + + + align:start position:0% +oh yeah that's really +nice so this is indenting cyclically + + align:start position:0% +nice so this is indenting cyclically + + + align:start position:0% +nice so this is indenting cyclically +into the pdms so The Fringe moving shows + + align:start position:0% +into the pdms so The Fringe moving shows + + + align:start position:0% +into the pdms so The Fringe moving shows +that he's moving in and out of the + + align:start position:0% + + + + align:start position:0% + +sample did you stop it yeah I I'll sa + + align:start position:0% +sample did you stop it yeah I I'll sa + + + align:start position:0% +sample did you stop it yeah I I'll sa +this one + + align:start position:0% + + + + align:start position:0% + +over + + align:start position:0% +over + + + align:start position:0% +over +and this is art or the soft we don't + + align:start position:0% +and this is art or the soft we don't + + + align:start position:0% +and this is art or the soft we don't +know actually so this I'll save this as + + align:start position:0% +know actually so this I'll save this as + + + align:start position:0% +know actually so this I'll save this as +unknown you can save it as left because + + align:start position:0% +unknown you can save it as left because + + + align:start position:0% +unknown you can save it as left because +left okay that's good oh you know what + + align:start position:0% +left okay that's good oh you know what + + + align:start position:0% +left okay that's good oh you know what +it is the box is labeled I think he + + align:start position:0% +it is the box is labeled I think he + + + align:start position:0% +it is the box is labeled I think he +didn't think it was but it's 25 pdms so + + align:start position:0% +didn't think it was but it's 25 pdms so + + + align:start position:0% +didn't think it was but it's 25 pdms so +that should be the stiffer one I laed it + + align:start position:0% +that should be the stiffer one I laed it + + + align:start position:0% +that should be the stiffer one I laed it +now oh okay 25 is actually the sof oh is + + align:start position:0% +now oh okay 25 is actually the sof oh is + + + align:start position:0% +now oh okay 25 is actually the sof oh is +it yeah + + align:start position:0% +it yeah + + + align:start position:0% +it yeah +because that represents the ratio in + + align:start position:0% +because that represents the ratio in + + + align:start position:0% +because that represents the ratio in +which I Mi the + + align:start position:0% +which I Mi the + + + align:start position:0% +which I Mi the +um puring agent to uh base polymer so + + align:start position:0% +um puring agent to uh base polymer so + + + align:start position:0% +um puring agent to uh base polymer so +it's Mally it's mixed 1 to 10 oh okay + + align:start position:0% +it's Mally it's mixed 1 to 10 oh okay + + + align:start position:0% +it's Mally it's mixed 1 to 10 oh okay +for like the standard recipe and I mixed + + align:start position:0% +for like the standard recipe and I mixed + + + align:start position:0% +for like the standard recipe and I mixed +one to 25 so this I thought it was 10% + + align:start position:0% +one to 25 so this I thought it was 10% + + + align:start position:0% +one to 25 so this I thought it was 10% +25% we don't use standardized things + + align:start position:0% +25% we don't use standardized things + + + align:start position:0% +25% we don't use standardized things +like per that's a silly way to \ No newline at end of file diff --git a/U8R54zOTVLw.txt b/U8R54zOTVLw.txt new file mode 100644 index 0000000000000000000000000000000000000000..ca74468da247f0df5a4c9ec2e57a19656464701c --- /dev/null +++ b/U8R54zOTVLw.txt @@ -0,0 +1,1571 @@ +align:start position:0% + +okay more about igen values and igen + + align:start position:0% +okay more about igen values and igen + + + align:start position:0% +okay more about igen values and igen +vectors well actually it's going to be + + align:start position:0% +vectors well actually it's going to be + + + align:start position:0% +vectors well actually it's going to be +the same thing about igen values and + + align:start position:0% +the same thing about igen values and + + + align:start position:0% +the same thing about igen values and +igen vectors but I'm going to use Matrix + + align:start position:0% +igen vectors but I'm going to use Matrix + + + align:start position:0% +igen vectors but I'm going to use Matrix +notation so you remember I have a matrix + + align:start position:0% +notation so you remember I have a matrix + + + align:start position:0% +notation so you remember I have a matrix +a 2X two for example it's got two igen + + align:start position:0% +a 2X two for example it's got two igen + + + align:start position:0% +a 2X two for example it's got two igen +vectors each igen Vector has its igen + + align:start position:0% +vectors each igen Vector has its igen + + + align:start position:0% +vectors each igen Vector has its igen +value so I could write + + align:start position:0% +value so I could write + + + align:start position:0% +value so I could write +the the IG Value World that that way I + + align:start position:0% +the the IG Value World that that way I + + + align:start position:0% +the the IG Value World that that way I +want to write it in Matrix form I want + + align:start position:0% +want to write it in Matrix form I want + + + align:start position:0% +want to write it in Matrix form I want +to create an igen Vector matrix by + + align:start position:0% +to create an igen Vector matrix by + + + align:start position:0% +to create an igen Vector matrix by +taking the two I vectors and putting + + align:start position:0% +taking the two I vectors and putting + + + align:start position:0% +taking the two I vectors and putting +them in The Columns of my Matrix so + + align:start position:0% +them in The Columns of my Matrix so + + + align:start position:0% +them in The Columns of my Matrix so +that's uh that if I have n of them that + + align:start position:0% +that's uh that if I have n of them that + + + align:start position:0% +that's uh that if I have n of them that +allows me to give one name the I Vector + + align:start position:0% +allows me to give one name the I Vector + + + align:start position:0% +allows me to give one name the I Vector +Matrix maybe I'll call it V for + + align:start position:0% +Matrix maybe I'll call it V for + + + align:start position:0% +Matrix maybe I'll call it V for +vectors so that's a * V + + align:start position:0% + + + + align:start position:0% + +and now just bear with me while I do + + align:start position:0% +and now just bear with me while I do + + + align:start position:0% +and now just bear with me while I do +that multiplication of a * the I Vector + + align:start position:0% +that multiplication of a * the I Vector + + + align:start position:0% +that multiplication of a * the I Vector +Matrix so what do I get I get a matrix + + align:start position:0% +Matrix so what do I get I get a matrix + + + align:start position:0% +Matrix so what do I get I get a matrix +that's 2x two that's 2x two I'm getting + + align:start position:0% +that's 2x two that's 2x two I'm getting + + + align:start position:0% +that's 2x two that's 2x two I'm getting +a 2X two Matrix what's the First Column + + align:start position:0% +a 2X two Matrix what's the First Column + + + align:start position:0% +a 2X two Matrix what's the First Column +the First Column of the output is a * + + align:start position:0% +the First Column of the output is a * + + + align:start position:0% +the First Column of the output is a * +the First Column of the input and what + + align:start position:0% +the First Column of the input and what + + + align:start position:0% +the First Column of the input and what +is a * X1 well a * X X1 is Lambda 1 * X1 + + align:start position:0% +is a * X1 well a * X X1 is Lambda 1 * X1 + + + align:start position:0% +is a * X1 well a * X X1 is Lambda 1 * X1 +so that First Column is Lambda 1 X1 and + + align:start position:0% +so that First Column is Lambda 1 X1 and + + + align:start position:0% +so that First Column is Lambda 1 X1 and +a times the second column is ax2 which + + align:start position:0% +a times the second column is ax2 which + + + align:start position:0% +a times the second column is ax2 which +is Lambda 2x2 so I'm seeing Lambda 2 x2 + + align:start position:0% +is Lambda 2x2 so I'm seeing Lambda 2 x2 + + + align:start position:0% +is Lambda 2x2 so I'm seeing Lambda 2 x2 +in that + + align:start position:0% +in that + + + align:start position:0% +in that +column okay Matrix notation those were + + align:start position:0% +column okay Matrix notation those were + + + align:start position:0% +column okay Matrix notation those were +the I vectors this is the result of a * + + align:start position:0% +the I vectors this is the result of a * + + + align:start position:0% +the I vectors this is the result of a * +V but but I can look at this a little + + align:start position:0% +V but but I can look at this a little + + + align:start position:0% +V but but I can look at this a little +differently I can say wait a minute that + + align:start position:0% +differently I can say wait a minute that + + + align:start position:0% +differently I can say wait a minute that +is my ion Vector Matrix X1 and X2 those + + align:start position:0% +is my ion Vector Matrix X1 and X2 those + + + align:start position:0% +is my ion Vector Matrix X1 and X2 those +two columns times a + + align:start position:0% +two columns times a + + + align:start position:0% +two columns times a +matrix ah yes I want to I'm I'm just + + align:start position:0% +matrix ah yes I want to I'm I'm just + + + align:start position:0% +matrix ah yes I want to I'm I'm just +taking this First Column Lambda 1x1 + + align:start position:0% +taking this First Column Lambda 1x1 + + + align:start position:0% +taking this First Column Lambda 1x1 +is Lambda 1 * X1 + 0 * X2 + + align:start position:0% + + + + align:start position:0% + +right there I did a matrix + + align:start position:0% +right there I did a matrix + + + align:start position:0% +right there I did a matrix +multiplication I did it without + + align:start position:0% +multiplication I did it without + + + align:start position:0% +multiplication I did it without +preparing you for it I'll I'll go back + + align:start position:0% +preparing you for it I'll I'll go back + + + align:start position:0% +preparing you for it I'll I'll go back +and do that preparation in a moment + + align:start position:0% +and do that preparation in a moment + + + align:start position:0% +and do that preparation in a moment +but when I multiply a matrix by a vector + + align:start position:0% +but when I multiply a matrix by a vector + + + align:start position:0% +but when I multiply a matrix by a vector +I take Lambda 1 time that one 0 * that + + align:start position:0% +I take Lambda 1 time that one 0 * that + + + align:start position:0% +I take Lambda 1 time that one 0 * that +one I get Lambda 1x1 which is what I + + align:start position:0% +one I get Lambda 1x1 which is what I + + + align:start position:0% +one I get Lambda 1x1 which is what I +want can you see what I want in the + + align:start position:0% +want can you see what I want in the + + + align:start position:0% +want can you see what I want in the +second column here + + align:start position:0% +second column here + + + align:start position:0% +second column here +I the result I want is Lambda + + align:start position:0% +I the result I want is Lambda + + + align:start position:0% +I the result I want is Lambda +2x2 so I want no + + align:start position:0% +2x2 so I want no + + + align:start position:0% +2x2 so I want no +x1's and Lambda + + align:start position:0% +x1's and Lambda + + + align:start position:0% +x1's and Lambda +2 of that column so that's 0 * that + + align:start position:0% +2 of that column so that's 0 * that + + + align:start position:0% +2 of that column so that's 0 * that +column plus Lambda 2 * that + + align:start position:0% +column plus Lambda 2 * that + + + align:start position:0% +column plus Lambda 2 * that +column are we okay so what do I have now + + align:start position:0% +column are we okay so what do I have now + + + align:start position:0% +column are we okay so what do I have now +I have the whole thing in a beautiful + + align:start position:0% +I have the whole thing in a beautiful + + + align:start position:0% +I have the whole thing in a beautiful +form as is a * the igon vector Matrix + + align:start position:0% +form as is a * the igon vector Matrix + + + align:start position:0% +form as is a * the igon vector Matrix +equals there's the igon vector Matrix + + align:start position:0% +equals there's the igon vector Matrix + + + align:start position:0% +equals there's the igon vector Matrix +again + + align:start position:0% +again + + + align:start position:0% +again +V and here is a new Matrix that I'm + + align:start position:0% +V and here is a new Matrix that I'm + + + align:start position:0% +V and here is a new Matrix that I'm +going to that's the + + align:start position:0% + + + + align:start position:0% + +igon value + + align:start position:0% + + + + align:start position:0% + +Matrix and + + align:start position:0% +Matrix and + + + align:start position:0% +Matrix and +everybody calls that because those are + + align:start position:0% +everybody calls that because those are + + + align:start position:0% +everybody calls that because those are +Lambda 1 and Lambda 2 so the natural + + align:start position:0% +Lambda 1 and Lambda 2 so the natural + + + align:start position:0% +Lambda 1 and Lambda 2 so the natural +letter is a capital Lambda that's a + + align:start position:0% +letter is a capital Lambda that's a + + + align:start position:0% +letter is a capital Lambda that's a +capital Greek Lambda there the best I + + align:start position:0% +capital Greek Lambda there the best I + + + align:start position:0% +capital Greek Lambda there the best I +could do so you see that the two + + align:start position:0% +could do so you see that the two + + + align:start position:0% +could do so you see that the two +equations SE written separately or the + + align:start position:0% +equations SE written separately or the + + + align:start position:0% +equations SE written separately or the +four equations or the N + + align:start position:0% +four equations or the N + + + align:start position:0% +four equations or the N +equations combine into one Matrix + + align:start position:0% +equations combine into one Matrix + + + align:start position:0% +equations combine into one Matrix +equation this is the same as those two + + align:start position:0% +equation this is the same as those two + + + align:start position:0% +equation this is the same as those two +together good good but now now that I + + align:start position:0% +together good good but now now that I + + + align:start position:0% +together good good but now now that I +have it in Matrix form I can mess around + + align:start position:0% +have it in Matrix form I can mess around + + + align:start position:0% +have it in Matrix form I can mess around +with it I can multiply both sides by V + + align:start position:0% +with it I can multiply both sides by V + + + align:start position:0% +with it I can multiply both sides by V +inverse If I multiply both sides by V + + align:start position:0% +inverse If I multiply both sides by V + + + align:start position:0% +inverse If I multiply both sides by V +inverse I I discover well shall I + + align:start position:0% +inverse I I discover well shall I + + + align:start position:0% +inverse I I discover well shall I +multiply on the left by V inverse yes + + align:start position:0% +multiply on the left by V inverse yes + + + align:start position:0% +multiply on the left by V inverse yes +I'll do that if I multiply on the left + + align:start position:0% +I'll do that if I multiply on the left + + + align:start position:0% +I'll do that if I multiply on the left +by V inverse that's V inverse a + + align:start position:0% +by V inverse that's V inverse a + + + align:start position:0% +by V inverse that's V inverse a +v so this the matrix multiplication and + + align:start position:0% +v so this the matrix multiplication and + + + align:start position:0% +v so this the matrix multiplication and +my next video is going to recap + + align:start position:0% +my next video is going to recap + + + align:start position:0% +my next video is going to recap +Matrix uh multiplication so I multiply + + align:start position:0% +Matrix uh multiplication so I multiply + + + align:start position:0% +Matrix uh multiplication so I multiply +both sides by V inverse V inverse time V + + align:start position:0% +both sides by V inverse V inverse time V + + + align:start position:0% +both sides by V inverse V inverse time V +is the identity that's what the inverse + + align:start position:0% +is the identity that's what the inverse + + + align:start position:0% +is the identity that's what the inverse +Matrix is V inverse V is the identity so + + align:start position:0% +Matrix is V inverse V is the identity so + + + align:start position:0% +Matrix is V inverse V is the identity so +there you go let me push that up that's + + align:start position:0% +there you go let me push that up that's + + + align:start position:0% +there you go let me push that up that's +really nice that's really nice that's + + align:start position:0% +really nice that's really nice that's + + + align:start position:0% +really nice that's really nice that's +called diagonalizing a i diagonalize a + + align:start position:0% +called diagonalizing a i diagonalize a + + + align:start position:0% +called diagonalizing a i diagonalize a +by taking the I Vector Matrix on the + + align:start position:0% +by taking the I Vector Matrix on the + + + align:start position:0% +by taking the I Vector Matrix on the +right its inverse on the left multiply + + align:start position:0% +right its inverse on the left multiply + + + align:start position:0% +right its inverse on the left multiply +those three matrices and I get this + + align:start position:0% +those three matrices and I get this + + + align:start position:0% +those three matrices and I get this +diagonal matrix this is the diagonal + + align:start position:0% +diagonal matrix this is the diagonal + + + align:start position:0% +diagonal matrix this is the diagonal +matrix Lambda + + align:start position:0% + + + + align:start position:0% + +or other times I might want to multiply + + align:start position:0% +or other times I might want to multiply + + + align:start position:0% +or other times I might want to multiply +by both sides here by V inverse on the + + align:start position:0% +by both sides here by V inverse on the + + + align:start position:0% +by both sides here by V inverse on the +coming on the right so that would give + + align:start position:0% +coming on the right so that would give + + + align:start position:0% +coming on the right so that would give +me a v v inverse is the identity so I'm + + align:start position:0% +me a v v inverse is the identity so I'm + + + align:start position:0% +me a v v inverse is the identity so I'm +I'm moving V I can move V over there as + + align:start position:0% +I'm moving V I can move V over there as + + + align:start position:0% +I'm moving V I can move V over there as +V inverse that's what it amounts to I + + align:start position:0% +V inverse that's what it amounts to I + + + align:start position:0% +V inverse that's what it amounts to I +multiply both sides by V inverse so this + + align:start position:0% +multiply both sides by V inverse so this + + + align:start position:0% +multiply both sides by V inverse so this +is just a and this is the V and the + + align:start position:0% +is just a and this is the V and the + + + align:start position:0% +is just a and this is the V and the +Lambda and now the V + + align:start position:0% +Lambda and now the V + + + align:start position:0% +Lambda and now the V +inverse that's + + align:start position:0% + + + + align:start position:0% + +great so that is that's a way to see + + align:start position:0% +great so that is that's a way to see + + + align:start position:0% +great so that is that's a way to see +what a how a is built + + align:start position:0% +what a how a is built + + + align:start position:0% +what a how a is built +up or broken down into the IG Vector + + align:start position:0% +up or broken down into the IG Vector + + + align:start position:0% +up or broken down into the IG Vector +Matrix times the igon value Matrix times + + align:start position:0% +Matrix times the igon value Matrix times + + + align:start position:0% +Matrix times the igon value Matrix times +the inverse of the I Vector Matrix okay + + align:start position:0% +the inverse of the I Vector Matrix okay + + + align:start position:0% +the inverse of the I Vector Matrix okay +let me just use that for a moment uh + + align:start position:0% +let me just use that for a moment uh + + + align:start position:0% +let me just use that for a moment uh +just so you see how it connects with + + align:start position:0% +just so you see how it connects with + + + align:start position:0% +just so you see how it connects with +what we already know about igen values + + align:start position:0% +what we already know about igen values + + + align:start position:0% +what we already know about igen values +and I vectors okay so I'll copy that + + align:start position:0% +and I vectors okay so I'll copy that + + + align:start position:0% +and I vectors okay so I'll copy that +great fact that + + align:start position:0% +great fact that + + + align:start position:0% +great fact that +a is V Lambda + + align:start position:0% +a is V Lambda + + + align:start position:0% +a is V Lambda +V + + align:start position:0% +V + + + align:start position:0% +V +inverse oh what do I want to do I want + + align:start position:0% +inverse oh what do I want to do I want + + + align:start position:0% +inverse oh what do I want to do I want +to look at a squ so if I look at a squ + + align:start position:0% +to look at a squ so if I look at a squ + + + align:start position:0% +to look at a squ so if I look at a squ +that's V V inverse + + align:start position:0% +that's V V inverse + + + align:start position:0% +that's V V inverse +times another + + align:start position:0% +times another + + + align:start position:0% +times another +one right there's an a there's an A so + + align:start position:0% +one right there's an a there's an A so + + + align:start position:0% +one right there's an a there's an A so +that's a s well you may say I've made a + + align:start position:0% +that's a s well you may say I've made a + + + align:start position:0% +that's a s well you may say I've made a +mess out of a squ but not true V inverse + + align:start position:0% +mess out of a squ but not true V inverse + + + align:start position:0% +mess out of a squ but not true V inverse +V is the + + align:start position:0% +V is the + + + align:start position:0% +V is the +identity so that's just the identity + + align:start position:0% +identity so that's just the identity + + + align:start position:0% +identity so that's just the identity +sitting in the middle so the V at the + + align:start position:0% +sitting in the middle so the V at the + + + align:start position:0% +sitting in the middle so the V at the +far left then I have the Lambda and then + + align:start position:0% +far left then I have the Lambda and then + + + align:start position:0% +far left then I have the Lambda and then +I have the other Lambda Lambda s squ and + + align:start position:0% +I have the other Lambda Lambda s squ and + + + align:start position:0% +I have the other Lambda Lambda s squ and +then the V inverse at the far + + align:start position:0% + + + + align:start position:0% + +right that's a + + align:start position:0% +right that's a + + + align:start position:0% +right that's a +2 and if I did it n times I would have a + + align:start position:0% +2 and if I did it n times I would have a + + + align:start position:0% +2 and if I did it n times I would have a +to the + + align:start position:0% +to the + + + align:start position:0% +to the +N would be + + align:start position:0% +N would be + + + align:start position:0% +N would be +V Lambda to the N power V inverse what + + align:start position:0% +V Lambda to the N power V inverse what + + + align:start position:0% +V Lambda to the N power V inverse what +is this what is this saying about this + + align:start position:0% +is this what is this saying about this + + + align:start position:0% +is this what is this saying about this +is a s + + align:start position:0% + + + + align:start position:0% + +what what how do I understand that + + align:start position:0% +what what how do I understand that + + + align:start position:0% +what what how do I understand that +equation I to me that says that the I + + align:start position:0% +equation I to me that says that the I + + + align:start position:0% +equation I to me that says that the I +values of a s are Lambda squar I'm just + + align:start position:0% +values of a s are Lambda squar I'm just + + + align:start position:0% +values of a s are Lambda squar I'm just +squaring each igen value and the igen + + align:start position:0% +squaring each igen value and the igen + + + align:start position:0% +squaring each igen value and the igen +vectors what are the I vectors of a s + + align:start position:0% +vectors what are the I vectors of a s + + + align:start position:0% +vectors what are the I vectors of a s +they're the same V the same vectors X1 + + align:start position:0% +they're the same V the same vectors X1 + + + align:start position:0% +they're the same V the same vectors X1 +X2 that went into V they they're also + + align:start position:0% +X2 that went into V they they're also + + + align:start position:0% +X2 that went into V they they're also +the ion vectors of a squ of a cubed of a + + align:start position:0% +the ion vectors of a squ of a cubed of a + + + align:start position:0% +the ion vectors of a squ of a cubed of a +to the N of a inverse and so that's the + + align:start position:0% +to the N of a inverse and so that's the + + + align:start position:0% +to the N of a inverse and so that's the +point of diagonalizing a matrix + + align:start position:0% +point of diagonalizing a matrix + + + align:start position:0% +point of diagonalizing a matrix +diagonalizing a matrix is another way to + + align:start position:0% +diagonalizing a matrix is another way to + + + align:start position:0% +diagonalizing a matrix is another way to +see that when I Square The Matrix which + + align:start position:0% +see that when I Square The Matrix which + + + align:start position:0% +see that when I Square The Matrix which +is usually a big + + align:start position:0% +is usually a big + + + align:start position:0% +is usually a big +mess look looking at the igen values and + + align:start position:0% +mess look looking at the igen values and + + + align:start position:0% +mess look looking at the igen values and +igen vectors it's the opposite of a big + + align:start position:0% +igen vectors it's the opposite of a big + + + align:start position:0% +igen vectors it's the opposite of a big +mess it's very clear the ion vectors are + + align:start position:0% +mess it's very clear the ion vectors are + + + align:start position:0% +mess it's very clear the ion vectors are +the same as for a + + align:start position:0% + + + + align:start position:0% + +and the igen values are + + align:start position:0% + + + + align:start position:0% + +squares of the I + + align:start position:0% +squares of the I + + + align:start position:0% +squares of the I +values of + + align:start position:0% + + + + align:start position:0% + +a in other + + align:start position:0% +a in other + + + align:start position:0% +a in other +words we can take the N power and we + + align:start position:0% +words we can take the N power and we + + + align:start position:0% +words we can take the N power and we +have a nice notation for it we we + + align:start position:0% +have a nice notation for it we we + + + align:start position:0% +have a nice notation for it we we +learned already that the N power has the + + align:start position:0% +learned already that the N power has the + + + align:start position:0% +learned already that the N power has the +igen values to the n power and the igen + + align:start position:0% +igen values to the n power and the igen + + + align:start position:0% +igen values to the n power and the igen +vector is the same but now I just see it + + align:start position:0% +vector is the same but now I just see it + + + align:start position:0% +vector is the same but now I just see it +here and there it is for the ins + + align:start position:0% + + + + align:start position:0% + +power so if I took the same Matrix step + + align:start position:0% +power so if I took the same Matrix step + + + align:start position:0% +power so if I took the same Matrix step +a thousand times what would be important + + align:start position:0% +a thousand times what would be important + + + align:start position:0% +a thousand times what would be important +what controls the thousandth power of a + + align:start position:0% +what controls the thousandth power of a + + + align:start position:0% +what controls the thousandth power of a +matrix the ion vectors + + align:start position:0% +matrix the ion vectors + + + align:start position:0% +matrix the ion vectors +stay they're just set it would be the + + align:start position:0% +stay they're just set it would be the + + + align:start position:0% +stay they're just set it would be the +thousandth power of the igen value so if + + align:start position:0% +thousandth power of the igen value so if + + + align:start position:0% +thousandth power of the igen value so if +this is a matrix with an igen value + + align:start position:0% +this is a matrix with an igen value + + + align:start position:0% +this is a matrix with an igen value +larger than one then the thousandth + + align:start position:0% +larger than one then the thousandth + + + align:start position:0% +larger than one then the thousandth +power is going to be much larger than + + align:start position:0% +power is going to be much larger than + + + align:start position:0% +power is going to be much larger than +one if this is a matrix with igen values + + align:start position:0% +one if this is a matrix with igen values + + + align:start position:0% +one if this is a matrix with igen values +smaller than one they're going to be + + align:start position:0% +smaller than one they're going to be + + + align:start position:0% +smaller than one they're going to be +very small for lamb when I take the + + align:start position:0% +very small for lamb when I take the + + + align:start position:0% +very small for lamb when I take the +thousandth power if if there's an IG + + align:start position:0% +thousandth power if if there's an IG + + + align:start position:0% +thousandth power if if there's an IG +value that's exactly one that will be a + + align:start position:0% +value that's exactly one that will be a + + + align:start position:0% +value that's exactly one that will be a +steady state and one to the thousandth + + align:start position:0% +steady state and one to the thousandth + + + align:start position:0% +steady state and one to the thousandth +power will still be one and nothing will + + align:start position:0% +power will still be one and nothing will + + + align:start position:0% +power will still be one and nothing will +change + + align:start position:0% +change + + + align:start position:0% +change +so the stability what happens as I + + align:start position:0% +so the stability what happens as I + + + align:start position:0% +so the stability what happens as I +multiply take powers of a matrix is a + + align:start position:0% +multiply take powers of a matrix is a + + + align:start position:0% +multiply take powers of a matrix is a +basic question parallel to the question + + align:start position:0% +basic question parallel to the question + + + align:start position:0% +basic question parallel to the question +what happens with a differential + + align:start position:0% +what happens with a differential + + + align:start position:0% +what happens with a differential +equation when I take the the solve + + align:start position:0% +equation when I take the the solve + + + align:start position:0% +equation when I take the the solve +forward in time I I think of those two + + align:start position:0% +forward in time I I think of those two + + + align:start position:0% +forward in time I I think of those two +problems as quite parallel this is + + align:start position:0% +problems as quite parallel this is + + + align:start position:0% +problems as quite parallel this is +taking steps single steps discrete steps + + align:start position:0% +taking steps single steps discrete steps + + + align:start position:0% +taking steps single steps discrete steps +the differential equation is moving + + align:start position:0% +the differential equation is moving + + + align:start position:0% +the differential equation is moving +forward + + align:start position:0% +forward + + + align:start position:0% +forward +continuously this the difference between + + align:start position:0% +continuously this the difference between + + + align:start position:0% +continuously this the difference between +hop hop hop in the discrete case and run + + align:start position:0% +hop hop hop in the discrete case and run + + + align:start position:0% +hop hop hop in the discrete case and run +forward continuously in the differential + + align:start position:0% +forward continuously in the differential + + + align:start position:0% +forward continuously in the differential +case in both cases the I vectors and the + + align:start position:0% +case in both cases the I vectors and the + + + align:start position:0% +case in both cases the I vectors and the +igen values are the guide to what + + align:start position:0% +igen values are the guide to what + + + align:start position:0% +igen values are the guide to what +happens as time goes forward okay I have + + align:start position:0% +happens as time goes forward okay I have + + + align:start position:0% +happens as time goes forward okay I have +to do more about matric working with + + align:start position:0% +to do more about matric working with + + + align:start position:0% +to do more about matric working with +matrices uh let me come to that + + align:start position:0% +matrices uh let me come to that + + + align:start position:0% +matrices uh let me come to that +next thanks \ No newline at end of file diff --git a/UDow47-q5KI.txt b/UDow47-q5KI.txt new file mode 100644 index 0000000000000000000000000000000000000000..28368913bb021df494af5c17525e7ed03fe378e4 --- /dev/null +++ b/UDow47-q5KI.txt @@ -0,0 +1,417 @@ +We'll describe the operation of the FSM for +our combination lock using a state transition + +diagram. + +Initially, the FSM has received no bits of +the combination, a state we'll call SX. + +In the state transition diagram, states are +represented as circles, each labeled for now + +with a symbolic name chosen to remind us of +what history it represents. + +For this FSM, the unlock output U will be +a function of the current state, so we'll + +indicate the value of U inside the circle. + +Since in state SX we know nothing about past +input bits, the lock should stay locked and + +so U = 0. + +We'll indicate the initial state with a wide +border on the circle. + +We'll use the successive states to remember +what we've seen so far of the input combination. + +So if the FSM is in state SX and it receives +a 0 input, it should transition to state S0 + +to remind us that we've seen the first bit +of the combination of 0-1-1-0. + +We use arrows to indicate transitions between +states and each arrow has a label telling + +us when that transition should occur. + +So this particular arrow is telling us that +when the FSM is in state SX and the next input + +is a 0, the FSM should transition to state +S0. + +Transitions are triggered by the rising edge +of the FSM's clock input. + +Let's add the states for the remainder of +the specified combination. + +The rightmost state, S0110, represents the +point at which the FSM has detected the specified + +sequence of inputs, so the unlock signal is +1 in this state. + +Looking at the state transition diagram, we +see that if the FSM starts in state SX, the + +input sequence 0-1-1-0 will leave the FSM +in state S0110. + +So far, so good. + +What should the FSM do if an input bit is +not the next bit in the combination? + +For example, if the FSM is in state SX and +the input bit is a 1, it still has not received + +any correct combination bits, so the next +state is SX again. + +Here are the appropriate non-combination transitions +for the other states. + +Note that an incorrect combination entry doesn't +necessarily take the FSM to state SX. + +For example, if the FSM is in state S0110, +the last four input bits have been 0-1-1-0. + +If the next input is a 1, then the last four +inputs bits are now 1-1-0-1, which won't lead + +to an open lock. + +But the last two bits might be the first two +bits of a valid combination sequence and so + +the FSM transitions to S01, indicating that +a sequence of 0-1 has been entered over the + +last two bits. + +We've been working with an FSM where the outputs +are function of the current state, called + +a Moore machine. + +Here the outputs are written inside the state +circle. + +If the outputs are a function of both the +current state and the current inputs, it's + +called a Mealy machine. + +Since the transitions are also a function +of the current state and current inputs, we'll + +label each transition with appropriate output +values using a slash to separate input values + +from output values. + +So, looking at the state transition diagram +on the right, suppose the FSM is in state + +S3. + +If the input is a 0, look for the arrow leaving +S3 labeled "0/". + +The value after the slash tells us the output +value, in this case 1. + +If the input had been a 1, the output value +would be 0. + +There are some simple rules we can use to +check that a state transition diagram is well + +formed. + +The transitions from a particular state must +be mutually exclusive, i.e., for a each state, + +there can't be more than one transition with +the same input label. + +This makes sense: if the FSM is to operate +consistently there can't be any ambiguity + +about the next state for a given current state +and input. + +By "consistently" we mean that the FSM should +make the same transitions if it's restarted + +at the same starting state and given the same +input sequences. + +Moreover, the transitions leaving each state +should be collectively exhaustive, i.e., there + +should a transition specified for each possible +input value. + +If we wish the FSM to stay in it's current +state for that particular input value, we + +need to show a transition from the current +state back to itself. + +With these rules there will be exactly one +transition selected for every combination + +of current state and input value. + +All the information in a state transition +diagram can be represented in tabular form + +as a truth table. + +The rows of the truth table list all the possible +combinations of current state and inputs. + +And the output columns of the truth table +tell us the next state and output value associated + +with each row. + +If we substitute binary values for the symbolic +state names, we end up with a truth table + +just like the ones we saw in Chapter 4. + +If we have K states in our state transition +diagram we'll need log_2(K) state bits, rounded + +up to the next integer since we don't have +fractional bits! + +In our example, we have a 5-state FSM, so +we'll need 3 state bits. + +We can assign the state encodings in any convenient +way, e.g., 000 for the first state, 001 for + +the second state, and so on. + +But the choice of state encodings can have +a big effect on the logic needed to implement + +the truth table. + +It's actually fun to figure out the state +encoding that produces the simplest possible + +logic. + +With a truth table in hand, we can use the +techniques from Chapter 4 to design logic + +circuits that implement the combinational +logic for the FSM. + +Of course, we can take the easy way out and +simply use a read-only memory to do the job! + +In this circuit, a read-only memory is used +to compute the next state and outputs from + +the current state and inputs. + +We're encoding the 5 states of the FSM using +a 3-bit binary value, so we have a 3-bit state + +register. + +The rectangle with the edge-triggered input +is schematic shorthand for a multi-bit register. + +If a wire in the diagram represents a multi-bit +signal, we use a little slash across the wire + +with a number to indicate how many bits are +in the signal. + +In this example, both current_state and next_state +are 3-bit signals. + +The read-only memory has a total of 4 input +signals - 3 for the current state and 1 for + +the input value - +so the read-only memory has 2^4 or 16 locations, + +which correspond to the 16 rows in the truth +table. + +Each location in the ROM supplies the output +values for a particular row of the truth table. + +Since we have 4 output signals - 3 for the +next state and 1 for the output value - each + +location supplies 4 bits of information. + +Memories are often annotated with their number +of locations and the number of bits in each + +location. + +So our memory is a 16-by-4 ROM: 16 locations +of 4-bits each. + +Of course, in order for the state registers +to work correctly, we need to ensure that + +the dynamic discipline is obeyed. + +We can use the timing analysis techniques +described at the end of Chapter 5 to check + +that this is so. + +For now, we'll assume that the timing of transitions +on the inputs are properly synchronized with + +the rising edges of the clock. + +So now we have the FSM abstraction to use +when designing the functionality of a sequential + +logic system, and a general-purpose circuit +implementation of the FSM using a ROM and + +a multi-bit state register. + +Recapping our design choices: the output bits +can be strictly a function of the current + +state (the FSM would then be called a Moore +machine), + +or they can be a function of both the current +state and current inputs, in which case the + +FSM is called a Mealy machine. + +We can choose the number of state bits - S +state bits will give us the ability to encode + +2^S possible states. + +Note that each extra state bit DOUBLES the +number of locations in the ROM! + +So when using ROMs to implement the necessary +logic, we're very interested in minimizing + +the number of state bits. + +The waveforms for our circuitry are pretty +straightforward. + +The rising edge of the clock triggers a transition +in the state register outputs. + +The ROM then does its thing, calculating the +next state, which becomes valid at some point + +in the clock cycle. + +This is the value that gets loaded into the +state registers at the next rising clock edge. + +This process repeats over-and-over as the +FSM follows the state transitions dictated + +by the state transition diagram. + +There are a few housekeeping details that +need our attention. + +On start-up we need some way to set the initial +contents of the state register to the correct + +encoding for the initial state. + +Many designs use a RESET signal that's set +to 1 to force some initial state and then + +set to 0 to start execution. + +We could adopt that approach here, using the +RESET signal to select an initial value to + +be loaded into the state register. + +In our example, we used a 3-bit state encoding +which would allow us to implement an FSM with + +up to 2^3 = 8 states. + +We're only using 5 of these encodings, which +means there are locations in the ROM we'll + +never access. + +If that's a concern, we can always use logic +gates to implement the necessary combinational + +logic instead of ROMs. + +Suppose the state register somehow got loaded +with one of the unused encodings? + +Well, that would be like being in a state +that's not listed in our state transition + +diagram. + +One way to defend against this problem is +design the ROM contents so that unused states + +always point to the initial state. + +In theory the problem should never arise, +but with this fix at least it won't lead to + +unknown behavior. + +We mentioned earlier the interesting problem +of finding a state encoding that minimized + +the combinational logic. + +There are computer-aided design tools to help +do this as part of the larger problem of finding + +minimal logic implementations for Boolean +functions. + +Mr. Blue is showing us another approach to +building the state register for the combination + +lock: +use a shift register to capture the last four + +input bits, then simply look at the recorded +history to determine if it matches the combination. + +No fancy next0state logic here! + +Finally, we still have to address the problem +of ensuring that input transitions don't violate + +the dynamic discipline for the state register. + +We'll get to this in the last section of this +chapter. \ No newline at end of file diff --git a/UmLCGjbeeJ8.txt b/UmLCGjbeeJ8.txt new file mode 100644 index 0000000000000000000000000000000000000000..441916bf1e3021c45a3b209a4238b5e81dcb254e --- /dev/null +++ b/UmLCGjbeeJ8.txt @@ -0,0 +1,2443 @@ +align:start position:0% + +our discussion about the future of the + + align:start position:0% +our discussion about the future of the + + + align:start position:0% +our discussion about the future of the +workforce would not be complete without + + align:start position:0% +workforce would not be complete without + + + align:start position:0% +workforce would not be complete without +an exploration of what impact the + + align:start position:0% +an exploration of what impact the + + + align:start position:0% +an exploration of what impact the +current innovations in technology will + + align:start position:0% +current innovations in technology will + + + align:start position:0% +current innovations in technology will +have specifically artificial + + align:start position:0% +have specifically artificial + + + align:start position:0% +have specifically artificial +intelligence over the past few years + + align:start position:0% +intelligence over the past few years + + + align:start position:0% +intelligence over the past few years +there have been significant innovations + + align:start position:0% +there have been significant innovations + + + align:start position:0% +there have been significant innovations +in big data database architecture and + + align:start position:0% +in big data database architecture and + + + align:start position:0% +in big data database architecture and +artificial intelligence that are + + align:start position:0% +artificial intelligence that are + + + align:start position:0% +artificial intelligence that are +enabling new business models and + + align:start position:0% +enabling new business models and + + + align:start position:0% +enabling new business models and +products and simplest terms the + + align:start position:0% +products and simplest terms the + + + align:start position:0% +products and simplest terms the +innovations and artificial intelligence + + align:start position:0% +innovations and artificial intelligence + + + align:start position:0% +innovations and artificial intelligence +are equipping algorithms to make smarter + + align:start position:0% +are equipping algorithms to make smarter + + + align:start position:0% +are equipping algorithms to make smarter +decisions about tasks and problems that + + align:start position:0% +decisions about tasks and problems that + + + align:start position:0% +decisions about tasks and problems that +have so far been thought only to be + + align:start position:0% +have so far been thought only to be + + + align:start position:0% +have so far been thought only to be +reserved for humans the accompanying + + align:start position:0% +reserved for humans the accompanying + + + align:start position:0% +reserved for humans the accompanying +innovations and cheapening of hardware + + align:start position:0% +innovations and cheapening of hardware + + + align:start position:0% +innovations and cheapening of hardware +that enables artificial intelligence + + align:start position:0% +that enables artificial intelligence + + + align:start position:0% +that enables artificial intelligence +algorithms to read in process incredibly + + align:start position:0% +algorithms to read in process incredibly + + + align:start position:0% +algorithms to read in process incredibly +large data sets has motivated more + + align:start position:0% +large data sets has motivated more + + + align:start position:0% +large data sets has motivated more +entrepreneurs and technologists to + + align:start position:0% +entrepreneurs and technologists to + + + align:start position:0% +entrepreneurs and technologists to +innovate with artificial intelligence + + align:start position:0% +innovate with artificial intelligence + + + align:start position:0% +innovate with artificial intelligence +many think that the implications for the + + align:start position:0% +many think that the implications for the + + + align:start position:0% +many think that the implications for the +workplace will hurt workers similar to + + align:start position:0% +workplace will hurt workers similar to + + + align:start position:0% +workplace will hurt workers similar to +how the Industrial Revolution displaced + + align:start position:0% +how the Industrial Revolution displaced + + + align:start position:0% +how the Industrial Revolution displaced +many workers through the creation of + + align:start position:0% +many workers through the creation of + + + align:start position:0% +many workers through the creation of +tech that was cheaper and overall more + + align:start position:0% +tech that was cheaper and overall more + + + align:start position:0% +tech that was cheaper and overall more +efficient than people people believe + + align:start position:0% +efficient than people people believe + + + align:start position:0% +efficient than people people believe +that AI will replace and not just + + align:start position:0% +that AI will replace and not just + + + align:start position:0% +that AI will replace and not just +blue-collar workers but also + + align:start position:0% +blue-collar workers but also + + + align:start position:0% +blue-collar workers but also +white-collar workers however the fact is + + align:start position:0% +white-collar workers however the fact is + + + align:start position:0% +white-collar workers however the fact is +that the impact on workers is under our + + align:start position:0% +that the impact on workers is under our + + + align:start position:0% +that the impact on workers is under our +control the control of entrepreneurs + + align:start position:0% +control the control of entrepreneurs + + + align:start position:0% +control the control of entrepreneurs +technologists and everyday citizens that + + align:start position:0% +technologists and everyday citizens that + + + align:start position:0% +technologists and everyday citizens that +are part of the workforce business + + align:start position:0% +are part of the workforce business + + + align:start position:0% +are part of the workforce business +owners and workers can harness AI to + + align:start position:0% +owners and workers can harness AI to + + + align:start position:0% +owners and workers can harness AI to +augment human intelligence in the + + align:start position:0% +augment human intelligence in the + + + align:start position:0% +augment human intelligence in the +workplace to creatively improve + + align:start position:0% +workplace to creatively improve + + + align:start position:0% +workplace to creatively improve +decision-making instead of replacing it + + align:start position:0% +decision-making instead of replacing it + + + align:start position:0% +decision-making instead of replacing it +here is Rob hi the CTO of IBM Watson one + + align:start position:0% +here is Rob hi the CTO of IBM Watson one + + + align:start position:0% +here is Rob hi the CTO of IBM Watson one +of the primary rd leaders in the AI + + align:start position:0% +of the primary rd leaders in the AI + + + align:start position:0% +of the primary rd leaders in the AI +space making this exact point at the + + align:start position:0% +space making this exact point at the + + + align:start position:0% +space making this exact point at the +2016 MIT technology conference right if + + align:start position:0% +2016 MIT technology conference right if + + + align:start position:0% +2016 MIT technology conference right if +we if we become experts and everything + + align:start position:0% +we if we become experts and everything + + + align:start position:0% +we if we become experts and everything +we're experts in nothing and so the same + + align:start position:0% +we're experts in nothing and so the same + + + align:start position:0% +we're experts in nothing and so the same +phenomenon occurs within these cognitive + + align:start position:0% +phenomenon occurs within these cognitive + + + align:start position:0% +phenomenon occurs within these cognitive +systems as well they can actually begin + + align:start position:0% +systems as well they can actually begin + + + align:start position:0% +systems as well they can actually begin +to get a little bit confused and in how + + align:start position:0% +to get a little bit confused and in how + + + align:start position:0% +to get a little bit confused and in how +to how to disambiguate question so a + + align:start position:0% +to how to disambiguate question so a + + + align:start position:0% +to how to disambiguate question so a +couple points to be made about that that + + align:start position:0% +couple points to be made about that that + + + align:start position:0% +couple points to be made about that that +said because each of these are distinct + + align:start position:0% +said because each of these are distinct + + + align:start position:0% +said because each of these are distinct +we can actually set the system up based + + align:start position:0% +we can actually set the system up based + + + align:start position:0% +we can actually set the system up based +on whatever is appropriate for the + + align:start position:0% +on whatever is appropriate for the + + + align:start position:0% +on whatever is appropriate for the +application we're trying to solve for + + align:start position:0% +application we're trying to solve for + + + align:start position:0% +application we're trying to solve for +for the case of oncology treatment + + align:start position:0% +for the case of oncology treatment + + + align:start position:0% +for the case of oncology treatment +advice it's the goal is actually about + + align:start position:0% +advice it's the goal is actually about + + + align:start position:0% +advice it's the goal is actually about +trying to identify + + align:start position:0% +trying to identify + + + align:start position:0% +trying to identify +best treatment based on outcomes based + + align:start position:0% +best treatment based on outcomes based + + + align:start position:0% +best treatment based on outcomes based +on standard of care practices and + + align:start position:0% +on standard of care practices and + + + align:start position:0% +on standard of care practices and +clinical expertise based on similarity + + align:start position:0% +clinical expertise based on similarity + + + align:start position:0% +clinical expertise based on similarity +this patient to other patients and all + + align:start position:0% +this patient to other patients and all + + + align:start position:0% +this patient to other patients and all +this contribute to help Watson come back + + align:start position:0% +this contribute to help Watson come back + + + align:start position:0% +this contribute to help Watson come back +with an ordered list of potential + + align:start position:0% +with an ordered list of potential + + + align:start position:0% +with an ordered list of potential +treatments but we again we're not trying + + align:start position:0% +treatments but we again we're not trying + + + align:start position:0% +treatments but we again we're not trying +to make the decision for the human right + + align:start position:0% +to make the decision for the human right + + + align:start position:0% +to make the decision for the human right +we're not trying to think for the human + + align:start position:0% +we're not trying to think for the human + + + align:start position:0% +we're not trying to think for the human +we're trying to do is do the research + + align:start position:0% +we're trying to do is do the research + + + align:start position:0% +we're trying to do is do the research +for the human so the human can then go + + align:start position:0% +for the human so the human can then go + + + align:start position:0% +for the human so the human can then go +make the better sort of better in this + + align:start position:0% +make the better sort of better in this + + + align:start position:0% +make the better sort of better in this +case the doctor so we're not going to + + align:start position:0% +case the doctor so we're not going to + + + align:start position:0% +case the doctor so we're not going to +take we're not going to you know Watson + + align:start position:0% +take we're not going to you know Watson + + + align:start position:0% +take we're not going to you know Watson +doesn't make the decision about what + + align:start position:0% +doesn't make the decision about what + + + align:start position:0% +doesn't make the decision about what +treatment to give for the doctor it + + align:start position:0% +treatment to give for the doctor it + + + align:start position:0% +treatment to give for the doctor it +presents the doctor a set of relevant + + align:start position:0% +presents the doctor a set of relevant + + + align:start position:0% +presents the doctor a set of relevant +treatments that has been rationalized + + align:start position:0% +treatments that has been rationalized + + + align:start position:0% +treatments that has been rationalized +based on all their information at a + + align:start position:0% +based on all their information at a + + + align:start position:0% +based on all their information at a +speed that a doctor could not do on + + align:start position:0% +speed that a doctor could not do on + + + align:start position:0% +speed that a doctor could not do on +their own including finding all the + + align:start position:0% +their own including finding all the + + + align:start position:0% +their own including finding all the +literature that's relevant to support + + align:start position:0% +literature that's relevant to support + + + align:start position:0% +literature that's relevant to support +why they should believe in that + + align:start position:0% +why they should believe in that + + + align:start position:0% +why they should believe in that +treatment or not okay + + align:start position:0% + + + + align:start position:0% + +so what specific types of disruptions + + align:start position:0% +so what specific types of disruptions + + + align:start position:0% +so what specific types of disruptions +can we expect a I to cause for employers + + align:start position:0% +can we expect a I to cause for employers + + + align:start position:0% +can we expect a I to cause for employers +and employees let's take a look at what + + align:start position:0% +and employees let's take a look at what + + + align:start position:0% +and employees let's take a look at what +David otter a professor of economics at + + align:start position:0% +David otter a professor of economics at + + + align:start position:0% +David otter a professor of economics at +MIT said in the future work panel at the + + align:start position:0% +MIT said in the future work panel at the + + + align:start position:0% +MIT said in the future work panel at the +Nobel week dialogue of 2015 in terms of + + align:start position:0% +Nobel week dialogue of 2015 in terms of + + + align:start position:0% +Nobel week dialogue of 2015 in terms of +employment as we said earlier people + + align:start position:0% +employment as we said earlier people + + + align:start position:0% +employment as we said earlier people +have been worried for centuries about + + align:start position:0% +have been worried for centuries about + + + align:start position:0% +have been worried for centuries about +displacement of labor and labor has been + + align:start position:0% +displacement of labor and labor has been + + + align:start position:0% +displacement of labor and labor has been +vastly displaced right in the start of + + align:start position:0% +vastly displaced right in the start of + + + align:start position:0% +vastly displaced right in the start of +the 20th century forty percent of us + + align:start position:0% +the 20th century forty percent of us + + + align:start position:0% +the 20th century forty percent of us +employment was on in farms now it's + + align:start position:0% +employment was on in farms now it's + + + align:start position:0% +employment was on in farms now it's +under two percent we had no idea what + + align:start position:0% +under two percent we had no idea what + + + align:start position:0% +under two percent we had no idea what +was coming but it came we find uses for + + align:start position:0% +was coming but it came we find uses for + + + align:start position:0% +was coming but it came we find uses for +ourselves and that's partly because the + + align:start position:0% +ourselves and that's partly because the + + + align:start position:0% +ourselves and that's partly because the +technology augments us it doesn't just + + align:start position:0% +technology augments us it doesn't just + + + align:start position:0% +technology augments us it doesn't just +replace us it makes the rest of what we + + align:start position:0% +replace us it makes the rest of what we + + + align:start position:0% +replace us it makes the rest of what we +do more valuable right so you know I can + + align:start position:0% +do more valuable right so you know I can + + + align:start position:0% +do more valuable right so you know I can +make more as an uber driver then as a + + align:start position:0% +make more as an uber driver then as a + + + align:start position:0% +make more as an uber driver then as a +rickshaw driver not just because I'm in + + align:start position:0% +rickshaw driver not just because I'm in + + + align:start position:0% +rickshaw driver not just because I'm in +in the rich world but because I have a + + align:start position:0% +in the rich world but because I have a + + + align:start position:0% +in the rich world but because I have a +tool that makes me able to transport + + align:start position:0% +tool that makes me able to transport + + + align:start position:0% +tool that makes me able to transport +people much faster and further and more + + align:start position:0% +people much faster and further and more + + + align:start position:0% +people much faster and further and more +safely and more comfortably in a given + + align:start position:0% +safely and more comfortably in a given + + + align:start position:0% +safely and more comfortably in a given +amount of time in many many ways tools + + align:start position:0% +amount of time in many many ways tools + + + align:start position:0% +amount of time in many many ways tools +we make make our time more valuable + + align:start position:0% +we make make our time more valuable + + + align:start position:0% +we make make our time more valuable +because there's always some piece that + + align:start position:0% +because there's always some piece that + + + align:start position:0% +because there's always some piece that +we still have to supply and because that + + align:start position:0% +we still have to supply and because that + + + align:start position:0% +we still have to supply and because that +that becomes the scarce factor that + + align:start position:0% +that becomes the scarce factor that + + + align:start position:0% +that becomes the scarce factor that +raises our labor value so there's a + + align:start position:0% +raises our labor value so there's a + + + align:start position:0% +raises our labor value so there's a +challenge so now let me say but let's + + align:start position:0% +challenge so now let me say but let's + + + align:start position:0% +challenge so now let me say but let's +say I'm wrong and that we're going to be + + align:start position:0% +say I'm wrong and that we're going to be + + + align:start position:0% +say I'm wrong and that we're going to be +all replaced by robots right that they + + align:start position:0% +all replaced by robots right that they + + + align:start position:0% +all replaced by robots right that they +can do all the work we want is that a + + align:start position:0% +can do all the work we want is that a + + + align:start position:0% +can do all the work we want is that a +problem well if it's a problem it's a + + align:start position:0% +problem well if it's a problem it's a + + + align:start position:0% +problem well if it's a problem it's a +very unusual historical problem most + + align:start position:0% +very unusual historical problem most + + + align:start position:0% +very unusual historical problem most +problems economic problems societal + + align:start position:0% +problems economic problems societal + + + align:start position:0% +problems economic problems societal +problems are problems of scarcity of not + + align:start position:0% +problems are problems of scarcity of not + + + align:start position:0% +problems are problems of scarcity of not +having enough of something enough food + + align:start position:0% +having enough of something enough food + + + align:start position:0% +having enough of something enough food +enough power enough safety enough + + align:start position:0% +enough power enough safety enough + + + align:start position:0% +enough power enough safety enough +shelter + + align:start position:0% + + + + align:start position:0% + +in addition to changing the kinds of + + align:start position:0% +in addition to changing the kinds of + + + align:start position:0% +in addition to changing the kinds of +roles that workers can take on in the + + align:start position:0% +roles that workers can take on in the + + + align:start position:0% +roles that workers can take on in the +workplace hey I based innovation can + + align:start position:0% +workplace hey I based innovation can + + + align:start position:0% +workplace hey I based innovation can +also impact social inequality for better + + align:start position:0% +also impact social inequality for better + + + align:start position:0% +also impact social inequality for better +or worse to be determined by how we + + align:start position:0% +or worse to be determined by how we + + + align:start position:0% +or worse to be determined by how we +choose to behave for example women and + + align:start position:0% +choose to behave for example women and + + + align:start position:0% +choose to behave for example women and +people of color are very + + align:start position:0% +people of color are very + + + align:start position:0% +people of color are very +underrepresented among technology + + align:start position:0% +underrepresented among technology + + + align:start position:0% +underrepresented among technology +entrepreneurs that receive funding from + + align:start position:0% +entrepreneurs that receive funding from + + + align:start position:0% +entrepreneurs that receive funding from +venture capitalists for their + + align:start position:0% +venture capitalists for their + + + align:start position:0% +venture capitalists for their +enterprises adventure capital investment + + align:start position:0% +enterprises adventure capital investment + + + align:start position:0% +enterprises adventure capital investment +goes towards a more diverse set of + + align:start position:0% +goes towards a more diverse set of + + + align:start position:0% +goes towards a more diverse set of +entrepreneurs then we will see social + + align:start position:0% +entrepreneurs then we will see social + + + align:start position:0% +entrepreneurs then we will see social +inequality improved positively here is + + align:start position:0% +inequality improved positively here is + + + align:start position:0% +inequality improved positively here is +Amanda callow CEO of six sons a + + align:start position:0% +Amanda callow CEO of six sons a + + + align:start position:0% +Amanda callow CEO of six sons a +predictive intelligence platform for + + align:start position:0% +predictive intelligence platform for + + + align:start position:0% +predictive intelligence platform for +marketing and sales expanding on the + + align:start position:0% +marketing and sales expanding on the + + + align:start position:0% +marketing and sales expanding on the +current under representation based on + + align:start position:0% +current under representation based on + + + align:start position:0% +current under representation based on +her experiences the short answer is yes + + align:start position:0% +her experiences the short answer is yes + + + align:start position:0% +her experiences the short answer is yes +I feel supported but I do feel so I go + + align:start position:0% +I feel supported but I do feel so I go + + + align:start position:0% +I feel supported but I do feel so I go +to a lot of CEO events instead I mean + + align:start position:0% +to a lot of CEO events instead I mean + + + align:start position:0% +to a lot of CEO events instead I mean +like on a panel like this last I was in + + align:start position:0% +like on a panel like this last I was in + + + align:start position:0% +like on a panel like this last I was in +Hawaii just a little while ago 250 CEOs + + align:start position:0% +Hawaii just a little while ago 250 CEOs + + + align:start position:0% +Hawaii just a little while ago 250 CEOs +as the only woman an enterprise tech on + + align:start position:0% +as the only woman an enterprise tech on + + + align:start position:0% +as the only woman an enterprise tech on +less than one percent in this world and + + align:start position:0% +less than one percent in this world and + + + align:start position:0% +less than one percent in this world and +it's it's crazy and it's it doesn't feel + + align:start position:0% +it's it's crazy and it's it doesn't feel + + + align:start position:0% +it's it's crazy and it's it doesn't feel +right and I think it's because we're + + align:start position:0% +right and I think it's because we're + + + align:start position:0% +right and I think it's because we're +missing that confidence and the passion + + align:start position:0% +missing that confidence and the passion + + + align:start position:0% +missing that confidence and the passion +to go forward and want to dream big do I + + align:start position:0% +to go forward and want to dream big do I + + + align:start position:0% +to go forward and want to dream big do I +feel supported by the men i think yes + + align:start position:0% +feel supported by the men i think yes + + + align:start position:0% +feel supported by the men i think yes +I'm supported I think pretty much I feel + + align:start position:0% +I'm supported I think pretty much I feel + + + align:start position:0% +I'm supported I think pretty much I feel +very supported especially my mail + + align:start position:0% +very supported especially my mail + + + align:start position:0% +very supported especially my mail +co-founders are ridiculously supportive + + align:start position:0% +co-founders are ridiculously supportive + + + align:start position:0% +co-founders are ridiculously supportive +and actually I think that they have more + + align:start position:0% +and actually I think that they have more + + + align:start position:0% +and actually I think that they have more +faith and confidence in me than I do + + align:start position:0% +faith and confidence in me than I do + + + align:start position:0% +faith and confidence in me than I do +myself which is amazing I think I have + + align:start position:0% +myself which is amazing I think I have + + + align:start position:0% +myself which is amazing I think I have +had to maybe guide and teach some of my + + align:start position:0% +had to maybe guide and teach some of my + + + align:start position:0% +had to maybe guide and teach some of my +VCS and other people in the world like + + align:start position:0% +VCS and other people in the world like + + + align:start position:0% +VCS and other people in the world like +what's important and it's not always + + align:start position:0% +what's important and it's not always + + + align:start position:0% +what's important and it's not always +just about like I think we're talking + + align:start position:0% +just about like I think we're talking + + + align:start position:0% +just about like I think we're talking +earlier about the end goal of the + + align:start position:0% +earlier about the end goal of the + + + align:start position:0% +earlier about the end goal of the +business and growing the business but + + align:start position:0% +business and growing the business but + + + align:start position:0% +business and growing the business but +creating a sustainable company is also + + align:start position:0% +creating a sustainable company is also + + + align:start position:0% +creating a sustainable company is also +about the culture and the people and I + + align:start position:0% +about the culture and the people and I + + + align:start position:0% +about the culture and the people and I +think that what what we're missing in + + align:start position:0% +think that what what we're missing in + + + align:start position:0% +think that what what we're missing in +today's workforce is putting an emphasis + + align:start position:0% +today's workforce is putting an emphasis + + + align:start position:0% +today's workforce is putting an emphasis +on that in addition to all the great + + align:start position:0% +on that in addition to all the great + + + align:start position:0% +on that in addition to all the great +technologies that we can do and that's + + align:start position:0% +technologies that we can do and that's + + + align:start position:0% +technologies that we can do and that's +the thing that the women bring to the + + align:start position:0% +the thing that the women bring to the + + + align:start position:0% +the thing that the women bring to the +table and you know I'm super proud of + + align:start position:0% +table and you know I'm super proud of + + + align:start position:0% +table and you know I'm super proud of +our lack of attrition rate at six cents + + align:start position:0% +our lack of attrition rate at six cents + + + align:start position:0% +our lack of attrition rate at six cents +like we don't have people leave and it's + + align:start position:0% +like we don't have people leave and it's + + + align:start position:0% +like we don't have people leave and it's +because they feel supported supported + + align:start position:0% +because they feel supported supported + + + align:start position:0% +because they feel supported supported +and heard and they can also be creative + + align:start position:0% +and heard and they can also be creative + + + align:start position:0% +and heard and they can also be creative +and do amazing things in the work that + + align:start position:0% +and do amazing things in the work that + + + align:start position:0% +and do amazing things in the work that +we're providing but I think there's I + + align:start position:0% +we're providing but I think there's I + + + align:start position:0% +we're providing but I think there's I +mean I think we're all it's not + + align:start position:0% +mean I think we're all it's not + + + align:start position:0% +mean I think we're all it's not +intentional when men aren't supporting + + align:start position:0% +intentional when men aren't supporting + + + align:start position:0% +intentional when men aren't supporting +you know I was actually sitting on a + + align:start position:0% +you know I was actually sitting on a + + + align:start position:0% +you know I was actually sitting on a +plane the other day talking to a + + align:start position:0% +plane the other day talking to a + + + align:start position:0% +plane the other day talking to a +gentleman and he asked me what I did and + + align:start position:0% +gentleman and he asked me what I did and + + + align:start position:0% +gentleman and he asked me what I did and +I never come out and say I'm a CEO this + + align:start position:0% +I never come out and say I'm a CEO this + + + align:start position:0% +I never come out and say I'm a CEO this +company I say I work for a software + + align:start position:0% +company I say I work for a software + + + align:start position:0% +company I say I work for a software +company I started talking about the + + align:start position:0% +company I started talking about the + + + align:start position:0% +company I started talking about the +stuff that we're doing and then two + + align:start position:0% +stuff that we're doing and then two + + + align:start position:0% +stuff that we're doing and then two +hours into the Congress + + align:start position:0% +hours into the Congress + + + align:start position:0% +hours into the Congress +hey it's like what do you do there and + + align:start position:0% +hey it's like what do you do there and + + + align:start position:0% +hey it's like what do you do there and +he's like are you in marketing and it's + + align:start position:0% +he's like are you in marketing and it's + + + align:start position:0% +he's like are you in marketing and it's +like no I'm the CEO and he got up from + + align:start position:0% +like no I'm the CEO and he got up from + + + align:start position:0% +like no I'm the CEO and he got up from +his seat and he had this like visceral + + align:start position:0% +his seat and he had this like visceral + + + align:start position:0% +his seat and he had this like visceral +reaction like he and he didn't mean to + + align:start position:0% +reaction like he and he didn't mean to + + + align:start position:0% +reaction like he and he didn't mean to +him then he sat down he's like I'm so + + align:start position:0% +him then he sat down he's like I'm so + + + align:start position:0% +him then he sat down he's like I'm so +sorry I didn't mean to react like that + + align:start position:0% +sorry I didn't mean to react like that + + + align:start position:0% +sorry I didn't mean to react like that +and it didn't intend to wait you're + + align:start position:0% +and it didn't intend to wait you're + + + align:start position:0% +and it didn't intend to wait you're +missing it you know it was it was just a + + align:start position:0% +missing it you know it was it was just a + + + align:start position:0% +missing it you know it was it was just a +lack of filter which we all have + + align:start position:0% +lack of filter which we all have + + + align:start position:0% +lack of filter which we all have +sometimes you know when he was realizing + + align:start position:0% +sometimes you know when he was realizing + + + align:start position:0% +sometimes you know when he was realizing +who I was in the company and I wear + + align:start position:0% +who I was in the company and I wear + + + align:start position:0% +who I was in the company and I wear +braids and pigtails and I don't always + + align:start position:0% +braids and pigtails and I don't always + + + align:start position:0% +braids and pigtails and I don't always +you know dress the part of you know + + align:start position:0% +you know dress the part of you know + + + align:start position:0% +you know dress the part of you know +something else I always struggle with + + align:start position:0% +something else I always struggle with + + + align:start position:0% +something else I always struggle with +being my authentic women's self I want + + align:start position:0% +being my authentic women's self I want + + + align:start position:0% +being my authentic women's self I want +to maintain that while dominating in the + + align:start position:0% +to maintain that while dominating in the + + + align:start position:0% +to maintain that while dominating in the +mail world that I'm in so I think there + + align:start position:0% +mail world that I'm in so I think there + + + align:start position:0% +mail world that I'm in so I think there +are just there are levels of education + + align:start position:0% +are just there are levels of education + + + align:start position:0% +are just there are levels of education +that we can give others for taking + + align:start position:0% +that we can give others for taking + + + align:start position:0% +that we can give others for taking +income and social inequality between + + align:start position:0% +income and social inequality between + + + align:start position:0% +income and social inequality between +genders will not improve unless we + + align:start position:0% +genders will not improve unless we + + + align:start position:0% +genders will not improve unless we +choose to make fair decisions about who + + align:start position:0% +choose to make fair decisions about who + + + align:start position:0% +choose to make fair decisions about who +gets opportunities to create and run + + align:start position:0% +gets opportunities to create and run + + + align:start position:0% +gets opportunities to create and run +companies in the tech industry if we do + + align:start position:0% +companies in the tech industry if we do + + + align:start position:0% +companies in the tech industry if we do +not actively monitor our biases we will + + align:start position:0% +not actively monitor our biases we will + + + align:start position:0% +not actively monitor our biases we will +not be able to take advantage of this + + align:start position:0% +not be able to take advantage of this + + + align:start position:0% +not be able to take advantage of this +period of innovation and wealth creation + + align:start position:0% +period of innovation and wealth creation + + + align:start position:0% +period of innovation and wealth creation +towards a more equitable future there is + + align:start position:0% +towards a more equitable future there is + + + align:start position:0% +towards a more equitable future there is +also an opportunity gap among people for + + align:start position:0% +also an opportunity gap among people for + + + align:start position:0% +also an opportunity gap among people for +who gets to work within companies in the + + align:start position:0% +who gets to work within companies in the + + + align:start position:0% +who gets to work within companies in the +tech industry Layla Jenna founder and + + align:start position:0% +tech industry Layla Jenna founder and + + + align:start position:0% +tech industry Layla Jenna founder and +CEO of summer group an organization that + + align:start position:0% +CEO of summer group an organization that + + + align:start position:0% +CEO of summer group an organization that +lift people out of poverty by enabling + + align:start position:0% +lift people out of poverty by enabling + + + align:start position:0% +lift people out of poverty by enabling +them to do work in the digital economy + + align:start position:0% +them to do work in the digital economy + + + align:start position:0% +them to do work in the digital economy +discusses this opportunity gap and how + + align:start position:0% +discusses this opportunity gap and how + + + align:start position:0% +discusses this opportunity gap and how +we can mitigate it now interestingly + + align:start position:0% +we can mitigate it now interestingly + + + align:start position:0% +we can mitigate it now interestingly +traditionally in the informal sector if + + align:start position:0% +traditionally in the informal sector if + + + align:start position:0% +traditionally in the informal sector if +you're doing say construction work and + + align:start position:0% +you're doing say construction work and + + + align:start position:0% +you're doing say construction work and +you go and you find your job by standing + + align:start position:0% +you go and you find your job by standing + + + align:start position:0% +you go and you find your job by standing +on the side of the road and waiting for + + align:start position:0% +on the side of the road and waiting for + + + align:start position:0% +on the side of the road and waiting for +someone to hire you as a labor + + align:start position:0% +someone to hire you as a labor + + + align:start position:0% +someone to hire you as a labor +contractor there is no such thing as + + align:start position:0% +contractor there is no such thing as + + + align:start position:0% +contractor there is no such thing as +getting rewarded for good work you might + + align:start position:0% +getting rewarded for good work you might + + + align:start position:0% +getting rewarded for good work you might +put in a wonderful 10-hour shift but you + + align:start position:0% +put in a wonderful 10-hour shift but you + + + align:start position:0% +put in a wonderful 10-hour shift but you +will get no five-star rating on a + + align:start position:0% +will get no five-star rating on a + + + align:start position:0% +will get no five-star rating on a +website you go back to zero the next day + + align:start position:0% +website you go back to zero the next day + + + align:start position:0% +website you go back to zero the next day +standing on the side of the road waiting + + align:start position:0% +standing on the side of the road waiting + + + align:start position:0% +standing on the side of the road waiting +for your next job so I think that that + + align:start position:0% +for your next job so I think that that + + + align:start position:0% +for your next job so I think that that +technology actually brings a lot more + + align:start position:0% +technology actually brings a lot more + + + align:start position:0% +technology actually brings a lot more +transparency in areas like wages and + + align:start position:0% +transparency in areas like wages and + + + align:start position:0% +transparency in areas like wages and +reviews and feedback that are very good + + align:start position:0% +reviews and feedback that are very good + + + align:start position:0% +reviews and feedback that are very good +for low-income workers and I'll say one + + align:start position:0% +for low-income workers and I'll say one + + + align:start position:0% +for low-income workers and I'll say one +last thing on this which is that Dave + + align:start position:0% +last thing on this which is that Dave + + + align:start position:0% +last thing on this which is that Dave +and I were talking about this just + + align:start position:0% +and I were talking about this just + + + align:start position:0% +and I were talking about this just +before the panel we so often assume that + + align:start position:0% +before the panel we so often assume that + + + align:start position:0% +before the panel we so often assume that +technology has some kind of morality + + align:start position:0% +technology has some kind of morality + + + align:start position:0% +technology has some kind of morality +built into it right technology in fact + + align:start position:0% +built into it right technology in fact + + + align:start position:0% +built into it right technology in fact +is agnostic it's as agnostic as roads + + align:start position:0% +is agnostic it's as agnostic as roads + + + align:start position:0% +is agnostic it's as agnostic as roads +waterways it's all about what we do with + + align:start position:0% +waterways it's all about what we do with + + + align:start position:0% +waterways it's all about what we do with +technology we can choose to inject + + align:start position:0% +technology we can choose to inject + + + align:start position:0% +technology we can choose to inject +morality into the technology we build we + + align:start position:0% +morality into the technology we build we + + + align:start position:0% +morality into the technology we build we +can choose to build systems that + + align:start position:0% +can choose to build systems that + + + align:start position:0% +can choose to build systems that +enfranchise the poor or we can choose + + align:start position:0% +enfranchise the poor or we can choose + + + align:start position:0% +enfranchise the poor or we can choose +not to but we're not victims of + + align:start position:0% +not to but we're not victims of + + + align:start position:0% +not to but we're not victims of +technological progress it's not + + align:start position:0% +technological progress it's not + + + align:start position:0% +technological progress it's not +happening you know in a way that we + + align:start position:0% +happening you know in a way that we + + + align:start position:0% +happening you know in a way that we +can't control at least until the + + align:start position:0% +can't control at least until the + + + align:start position:0% +can't control at least until the +singularity happens at which point all + + align:start position:0% +singularity happens at which point all + + + align:start position:0% +singularity happens at which point all +bets are off the first is job training + + align:start position:0% +bets are off the first is job training + + + align:start position:0% +bets are off the first is job training +needs to completely change in the US + + align:start position:0% +needs to completely change in the US + + + align:start position:0% +needs to completely change in the US +which is the best example I know it's + + align:start position:0% +which is the best example I know it's + + + align:start position:0% +which is the best example I know it's +abysmal we are still training people for + + align:start position:0% +abysmal we are still training people for + + + align:start position:0% +abysmal we are still training people for +jobs that are disappearing at an + + align:start position:0% +jobs that are disappearing at an + + + align:start position:0% +jobs that are disappearing at an +alarming rate we are not training them + + align:start position:0% +alarming rate we are not training them + + + align:start position:0% +alarming rate we are not training them +in how to be entrepreneurial and + + align:start position:0% +in how to be entrepreneurial and + + + align:start position:0% +in how to be entrepreneurial and +marketing themselves the skill that you + + align:start position:0% +marketing themselves the skill that you + + + align:start position:0% +marketing themselves the skill that you +need for 21st century jobs is marketing + + align:start position:0% +need for 21st century jobs is marketing + + + align:start position:0% +need for 21st century jobs is marketing +yourself if Kim Kardashian can teach us + + align:start position:0% +yourself if Kim Kardashian can teach us + + + align:start position:0% +yourself if Kim Kardashian can teach us +anything it's probably only that but + + align:start position:0% +anything it's probably only that but + + + align:start position:0% +anything it's probably only that but +interestingly you know we're see all of + + align:start position:0% +interestingly you know we're see all of + + + align:start position:0% +interestingly you know we're see all of +these new platforms require you to be + + align:start position:0% +these new platforms require you to be + + + align:start position:0% +these new platforms require you to be +able to set up a profile to choose the + + align:start position:0% +able to set up a profile to choose the + + + align:start position:0% +able to set up a profile to choose the +right kind of a photograph that will + + align:start position:0% +right kind of a photograph that will + + + align:start position:0% +right kind of a photograph that will +attract customers to send a follow up + + align:start position:0% +attract customers to send a follow up + + + align:start position:0% +attract customers to send a follow up +email to have customer service skills + + align:start position:0% +email to have customer service skills + + + align:start position:0% +email to have customer service skills +and you're absolutely right that many + + align:start position:0% +and you're absolutely right that many + + + align:start position:0% +and you're absolutely right that many +low income people and just to give you + + align:start position:0% +low income people and just to give you + + + align:start position:0% +low income people and just to give you +an idea of how profound this is in the + + align:start position:0% +an idea of how profound this is in the + + + align:start position:0% +an idea of how profound this is in the +u.s. we have one of our centers which is + + align:start position:0% +u.s. we have one of our centers which is + + + align:start position:0% +u.s. we have one of our centers which is +less than a mile from the facebook + + align:start position:0% +less than a mile from the facebook + + + align:start position:0% +less than a mile from the facebook +headquarters in Silicon Valley in East + + align:start position:0% +headquarters in Silicon Valley in East + + + align:start position:0% +headquarters in Silicon Valley in East +Palo Alto which is a very poor community + + align:start position:0% +Palo Alto which is a very poor community + + + align:start position:0% +Palo Alto which is a very poor community +and fully twenty five percent of our + + align:start position:0% +and fully twenty five percent of our + + + align:start position:0% +and fully twenty five percent of our +incoming class for one of our trainings + + align:start position:0% +incoming class for one of our trainings + + + align:start position:0% +incoming class for one of our trainings +last year had people who had zero + + align:start position:0% +last year had people who had zero + + + align:start position:0% +last year had people who had zero +internet access at home and no + + align:start position:0% +internet access at home and no + + + align:start position:0% +internet access at home and no +smartphone a mile from the Facebook + + align:start position:0% +smartphone a mile from the Facebook + + + align:start position:0% +smartphone a mile from the Facebook +campus so we can talk all we want about + + align:start position:0% +campus so we can talk all we want about + + + align:start position:0% +campus so we can talk all we want about +how technology is going to make + + align:start position:0% +how technology is going to make + + + align:start position:0% +how technology is going to make +everyone's lives better but the reality + + align:start position:0% +everyone's lives better but the reality + + + align:start position:0% +everyone's lives better but the reality +is that many people are disconnected and + + align:start position:0% +is that many people are disconnected and + + + align:start position:0% +is that many people are disconnected and +if you didn't grow up having the + + align:start position:0% +if you didn't grow up having the + + + align:start position:0% +if you didn't grow up having the +internet at home how can you possibly + + align:start position:0% +internet at home how can you possibly + + + align:start position:0% +internet at home how can you possibly +understand how to market yourself you're + + align:start position:0% +understand how to market yourself you're + + + align:start position:0% +understand how to market yourself you're +it's not easy to be an autodidact and to + + align:start position:0% +it's not easy to be an autodidact and to + + + align:start position:0% +it's not easy to be an autodidact and to +learn how to teach yourself yourself + + align:start position:0% +learn how to teach yourself yourself + + + align:start position:0% +learn how to teach yourself yourself +things on YouTube if you didn't grow up + + align:start position:0% +things on YouTube if you didn't grow up + + + align:start position:0% +things on YouTube if you didn't grow up +with the internet + + align:start position:0% + + + + align:start position:0% + +advancements in technology taking place + + align:start position:0% +advancements in technology taking place + + + align:start position:0% +advancements in technology taking place +right now are incredibly exciting and we + + align:start position:0% +right now are incredibly exciting and we + + + align:start position:0% +right now are incredibly exciting and we +all stand to gain from the most + + align:start position:0% +all stand to gain from the most + + + align:start position:0% +all stand to gain from the most +consumers however as with other periods + + align:start position:0% +consumers however as with other periods + + + align:start position:0% +consumers however as with other periods +of societal change we citizens and the + + align:start position:0% +of societal change we citizens and the + + + align:start position:0% +of societal change we citizens and the +government have to ensure that the + + align:start position:0% +government have to ensure that the + + + align:start position:0% +government have to ensure that the +opportunities to launch run and work in + + align:start position:0% +opportunities to launch run and work in + + + align:start position:0% +opportunities to launch run and work in +these new enterprises is made available + + align:start position:0% +these new enterprises is made available + + + align:start position:0% +these new enterprises is made available +to all members of society \ No newline at end of file diff --git a/UswuSLKQVK4.txt b/UswuSLKQVK4.txt new file mode 100644 index 0000000000000000000000000000000000000000..372c594172ff8d2b8836932ede3629492c862ea5 --- /dev/null +++ b/UswuSLKQVK4.txt @@ -0,0 +1,715 @@ +align:start position:0% + +I'm having our students be prepared to + + align:start position:0% +I'm having our students be prepared to + + + align:start position:0% +I'm having our students be prepared to +face fail it's really important because + + align:start position:0% +face fail it's really important because + + + align:start position:0% +face fail it's really important because +I think it's essential to the design + + align:start position:0% +I think it's essential to the design + + + align:start position:0% +I think it's essential to the design +process and I uh we have uh Professor + + align:start position:0% +process and I uh we have uh Professor + + + align:start position:0% +process and I uh we have uh Professor +Rob Miller came in to do a lecture on + + align:start position:0% +Rob Miller came in to do a lecture on + + + align:start position:0% +Rob Miller came in to do a lecture on +user Center design very early on in the + + align:start position:0% +user Center design very early on in the + + + align:start position:0% +user Center design very early on in the +semester where we basically present to + + align:start position:0% +semester where we basically present to + + + align:start position:0% +semester where we basically present to +them this design model of of you know + + align:start position:0% +them this design model of of you know + + + align:start position:0% +them this design model of of you know +where you do iterative design which + + align:start position:0% +where you do iterative design which + + + align:start position:0% +where you do iterative design which +means + + align:start position:0% +means + + + align:start position:0% +means +you quickly come up with a prototype you + + align:start position:0% +you quickly come up with a prototype you + + + align:start position:0% +you quickly come up with a prototype you +fail as fast as possible you figure out + + align:start position:0% +fail as fast as possible you figure out + + + align:start position:0% +fail as fast as possible you figure out +where everything's going wrong and then + + align:start position:0% +where everything's going wrong and then + + + align:start position:0% +where everything's going wrong and then +you make a second prototype you know and + + align:start position:0% +you make a second prototype you know and + + + align:start position:0% +you make a second prototype you know and +you keep going round and round and round + + align:start position:0% +you keep going round and round and round + + + align:start position:0% +you keep going round and round and round +this circle until you reach that perfect + + align:start position:0% +this circle until you reach that perfect + + + align:start position:0% +this circle until you reach that perfect +Prototype at the end of the day um and + + align:start position:0% +Prototype at the end of the day um and + + + align:start position:0% +Prototype at the end of the day um and +so I think they knew from the start that + + align:start position:0% +so I think they knew from the start that + + + align:start position:0% +so I think they knew from the start that +they were going to have to just keep + + align:start position:0% +they were going to have to just keep + + + align:start position:0% +they were going to have to just keep +making things and seeing how they were + + align:start position:0% +making things and seeing how they were + + + align:start position:0% +making things and seeing how they were +going to go wrong um and so yeah failure + + align:start position:0% +going to go wrong um and so yeah failure + + + align:start position:0% +going to go wrong um and so yeah failure +became very entrench as part of the + + align:start position:0% +became very entrench as part of the + + + align:start position:0% +became very entrench as part of the +design process in fact we told them + + align:start position:0% +design process in fact we told them + + + align:start position:0% +design process in fact we told them +right from the start we expect you to + + align:start position:0% +right from the start we expect you to + + + align:start position:0% +right from the start we expect you to +have three prototypes at least by the + + align:start position:0% +have three prototypes at least by the + + + align:start position:0% +have three prototypes at least by the +end of the semester and these are when + + align:start position:0% +end of the semester and these are when + + + align:start position:0% +end of the semester and these are when +your prototypes should be ready by and + + align:start position:0% +your prototypes should be ready by and + + + align:start position:0% +your prototypes should be ready by and +these are the weeks where you will get + + align:start position:0% +these are the weeks where you will get + + + align:start position:0% +these are the weeks where you will get +to test them and every week they had to + + align:start position:0% +to test them and every week they had to + + + align:start position:0% +to test them and every week they had to +come back and tell the mentors where + + align:start position:0% +come back and tell the mentors where + + + align:start position:0% +come back and tell the mentors where +things went well and where things didn't + + align:start position:0% +things went well and where things didn't + + + align:start position:0% +things went well and where things didn't +go well according to some uh set of + + align:start position:0% +go well according to some uh set of + + + align:start position:0% +go well according to some uh set of +success + + align:start position:0% +success + + + align:start position:0% +success +metrics yeah I think the design review + + align:start position:0% +metrics yeah I think the design review + + + align:start position:0% +metrics yeah I think the design review +these midterm panels were really just + + align:start position:0% +these midterm panels were really just + + + align:start position:0% +these midterm panels were really just +that to try to get feedback on the + + align:start position:0% +that to try to get feedback on the + + + align:start position:0% +that to try to get feedback on the +design or really explain the progress + + align:start position:0% +design or really explain the progress + + + align:start position:0% +design or really explain the progress +that they had made + + align:start position:0% +that they had made + + + align:start position:0% +that they had made +uh so far and so I think that that was a + + align:start position:0% +uh so far and so I think that that was a + + + align:start position:0% +uh so far and so I think that that was a +big reason why we did that I think + + align:start position:0% +big reason why we did that I think + + + align:start position:0% +big reason why we did that I think +having mentors this year was helpful on + + align:start position:0% +having mentors this year was helpful on + + + align:start position:0% +having mentors this year was helpful on +this front as well the mentors were + + align:start position:0% +this front as well the mentors were + + + align:start position:0% +this front as well the mentors were +pretty in touch with how teams were + + align:start position:0% +pretty in touch with how teams were + + + align:start position:0% +pretty in touch with how teams were +progressing we had uh each team fill out + + align:start position:0% +progressing we had uh each team fill out + + + align:start position:0% +progressing we had uh each team fill out +this little form um every week + + align:start position:0% +this little form um every week + + + align:start position:0% +this little form um every week +explaining what was going well and what + + align:start position:0% +explaining what was going well and what + + + align:start position:0% +explaining what was going well and what +they needed help with so I think a big + + align:start position:0% +they needed help with so I think a big + + + align:start position:0% +they needed help with so I think a big +part of it was kind of creating the + + align:start position:0% +part of it was kind of creating the + + + align:start position:0% +part of it was kind of creating the +culture that it doesn't have to go + + align:start position:0% +culture that it doesn't have to go + + + align:start position:0% +culture that it doesn't have to go +perfectly well every week there can be + + align:start position:0% +perfectly well every week there can be + + + align:start position:0% +perfectly well every week there can be +setbacks there can be different + + align:start position:0% +setbacks there can be different + + + align:start position:0% +setbacks there can be different +challenges or obstacles to over come but + + align:start position:0% +challenges or obstacles to over come but + + + align:start position:0% +challenges or obstacles to over come but +we're here to uh you know work through + + align:start position:0% +we're here to uh you know work through + + + align:start position:0% +we're here to uh you know work through +them and figure out how to deal with + + align:start position:0% +them and figure out how to deal with + + + align:start position:0% +them and figure out how to deal with +this uh situation or brainstorm some + + align:start position:0% +this uh situation or brainstorm some + + + align:start position:0% +this uh situation or brainstorm some +ideas one of the other things that we + + align:start position:0% +ideas one of the other things that we + + + align:start position:0% +ideas one of the other things that we +tried this year was to have these + + align:start position:0% +tried this year was to have these + + + align:start position:0% +tried this year was to have these +lightning updates at the end of every uh + + align:start position:0% +lightning updates at the end of every uh + + + align:start position:0% +lightning updates at the end of every uh +week's uh lab just to keep uh uh just to + + align:start position:0% +week's uh lab just to keep uh uh just to + + + align:start position:0% +week's uh lab just to keep uh uh just to +inform the rest of the class where + + align:start position:0% +inform the rest of the class where + + + align:start position:0% +inform the rest of the class where +you're at and what you were trying um uh + + align:start position:0% +you're at and what you were trying um uh + + + align:start position:0% +you're at and what you were trying um uh +what progress you were making I think + + align:start position:0% +what progress you were making I think + + + align:start position:0% +what progress you were making I think +this maybe set up a little bit of sort + + align:start position:0% +this maybe set up a little bit of sort + + + align:start position:0% +this maybe set up a little bit of sort +of friendly competition to kind of see + + align:start position:0% +of friendly competition to kind of see + + + align:start position:0% +of friendly competition to kind of see +where other projects are at but it also + + align:start position:0% +where other projects are at but it also + + + align:start position:0% +where other projects are at but it also +I think uh helped maybe the class feel + + align:start position:0% +I think uh helped maybe the class feel + + + align:start position:0% +I think uh helped maybe the class feel +like um We're All in This Together I + + align:start position:0% +like um We're All in This Together I + + + align:start position:0% +like um We're All in This Together I +suppose it's not always going to be easy + + align:start position:0% +suppose it's not always going to be easy + + + align:start position:0% +suppose it's not always going to be easy +maybe there's Logistics challenges maybe + + align:start position:0% +maybe there's Logistics challenges maybe + + + align:start position:0% +maybe there's Logistics challenges maybe +there's design challenges maybe there's + + align:start position:0% +there's design challenges maybe there's + + + align:start position:0% +there's design challenges maybe there's +um other sorts of things so I think um + + align:start position:0% +um other sorts of things so I think um + + + align:start position:0% +um other sorts of things so I think um +students were pretty open to sharing + + align:start position:0% +students were pretty open to sharing + + + align:start position:0% +students were pretty open to sharing +honestly what their progress was and + + align:start position:0% +honestly what their progress was and + + + align:start position:0% +honestly what their progress was and +what they were what they were doing at + + align:start position:0% +what they were what they were doing at + + + align:start position:0% +what they were what they were doing at +least that's what we we tried to do we + + align:start position:0% +least that's what we we tried to do we + + + align:start position:0% +least that's what we we tried to do we +hope so we did get feedback from + + align:start position:0% +hope so we did get feedback from + + + align:start position:0% +hope so we did get feedback from +students though that the lightning + + align:start position:0% +students though that the lightning + + + align:start position:0% +students though that the lightning +updates might have been too regular and + + align:start position:0% +updates might have been too regular and + + + align:start position:0% +updates might have been too regular and +they did say that it would have been + + align:start position:0% +they did say that it would have been + + + align:start position:0% +they did say that it would have been +nice to have it once every two weeks + + align:start position:0% +nice to have it once every two weeks + + + align:start position:0% +nice to have it once every two weeks +instead of every week um and that that + + align:start position:0% +instead of every week um and that that + + + align:start position:0% +instead of every week um and that that +would just give them more time to work + + align:start position:0% +would just give them more time to work + + + align:start position:0% +would just give them more time to work +together as a team and we realized too + + align:start position:0% +together as a team and we realized too + + + align:start position:0% +together as a team and we realized too +that for our students being able to do + + align:start position:0% +that for our students being able to do + + + align:start position:0% +that for our students being able to do +group work outside of class is actually + + align:start position:0% +group work outside of class is actually + + + align:start position:0% +group work outside of class is actually +difficult because they all have such + + align:start position:0% +difficult because they all have such + + + align:start position:0% +difficult because they all have such +busy schedules so anytime they had like + + align:start position:0% +busy schedules so anytime they had like + + + align:start position:0% +busy schedules so anytime they had like +structure time within a class to just do + + align:start position:0% +structure time within a class to just do + + + align:start position:0% +structure time within a class to just do +group work together that was really + + align:start position:0% +group work together that was really + + + align:start position:0% +group work together that was really +valuable for them \ No newline at end of file diff --git a/Uux0VkKaoxY.txt b/Uux0VkKaoxY.txt new file mode 100644 index 0000000000000000000000000000000000000000..6c8523c28ea31878e8573bce3957792b317ce704 --- /dev/null +++ b/Uux0VkKaoxY.txt @@ -0,0 +1,987 @@ +align:start position:0% + +so that's part of the story let's try to + + align:start position:0% +so that's part of the story let's try to + + + align:start position:0% +so that's part of the story let's try to +understand it a little better still so + + align:start position:0% +understand it a little better still so + + + align:start position:0% +understand it a little better still so +what does the state look like well the + + align:start position:0% +what does the state look like well the + + + align:start position:0% +what does the state look like well the +state looks like e to the ikx x times a + + align:start position:0% +state looks like e to the ikx x times a + + + align:start position:0% +state looks like e to the ikx x times a +state of the oscillator and Y okay so + + align:start position:0% +state of the oscillator and Y okay so + + + align:start position:0% +state of the oscillator and Y okay so +what what is happening here we could we + + align:start position:0% +what what is happening here we could we + + + align:start position:0% +what what is happening here we could we +solve this problem using a different + + align:start position:0% +solve this problem using a different + + + align:start position:0% +solve this problem using a different +gauge and you will you will solve it at + + align:start position:0% +gauge and you will you will solve it at + + + align:start position:0% +gauge and you will you will solve it at +least once or twice again this problem + + align:start position:0% +least once or twice again this problem + + + align:start position:0% +least once or twice again this problem +using a different gauge and the + + align:start position:0% +using a different gauge and the + + + align:start position:0% +using a different gauge and the +solutions are going to be looking a + + align:start position:0% +solutions are going to be looking a + + + align:start position:0% +solutions are going to be looking a +little different but of course you're + + align:start position:0% +little different but of course you're + + + align:start position:0% +little different but of course you're +going to find the same Landau levels and + + align:start position:0% +going to find the same Landau levels and + + + align:start position:0% +going to find the same Landau levels and +the same infinite degeneracy the wave + + align:start position:0% +the same infinite degeneracy the wave + + + align:start position:0% +the same infinite degeneracy the wave +functions will look sometimes a little + + align:start position:0% +functions will look sometimes a little + + + align:start position:0% +functions will look sometimes a little +more intuitive so in this case of one + + align:start position:0% +more intuitive so in this case of one + + + align:start position:0% +more intuitive so in this case of one +calculation that is interesting to try + + align:start position:0% +calculation that is interesting to try + + + align:start position:0% +calculation that is interesting to try +to understand the physics of this + + align:start position:0% +to understand the physics of this + + + align:start position:0% +to understand the physics of this +degeneracy is to work roughly a little + + align:start position:0% +degeneracy is to work roughly a little + + + align:start position:0% +degeneracy is to work roughly a little +heuristic aliy on a finite size sample + + align:start position:0% +heuristic aliy on a finite size sample + + + align:start position:0% +heuristic aliy on a finite size sample +you imagine a material but it's now + + align:start position:0% +you imagine a material but it's now + + + align:start position:0% +you imagine a material but it's now +finite size so let me remark to you what + + align:start position:0% +finite size so let me remark to you what + + + align:start position:0% +finite size so let me remark to you what +are the degrees of freedom you have here + + align:start position:0% +are the degrees of freedom you have here + + + align:start position:0% +are the degrees of freedom you have here +suppose you solve the Schrodinger + + align:start position:0% +suppose you solve the Schrodinger + + + align:start position:0% +suppose you solve the Schrodinger +equation in a different gauge a + + align:start position:0% +equation in a different gauge a + + + align:start position:0% +equation in a different gauge a +symmetric gauge in which there is an A Y + + align:start position:0% +symmetric gauge in which there is an A Y + + + align:start position:0% +symmetric gauge in which there is an A Y +and an ax solutions then are going to + + align:start position:0% +and an ax solutions then are going to + + + align:start position:0% +and an ax solutions then are going to +look a little more like circular orbits + + align:start position:0% +look a little more like circular orbits + + + align:start position:0% +look a little more like circular orbits +there's a little more mathematics + + align:start position:0% +there's a little more mathematics + + + align:start position:0% +there's a little more mathematics +involved in solving it but they're going + + align:start position:0% +involved in solving it but they're going + + + align:start position:0% +involved in solving it but they're going +to look a little nicer but how are they + + align:start position:0% +to look a little nicer but how are they + + + align:start position:0% +to look a little nicer but how are they +related to this ones well anyone with a + + align:start position:0% +related to this ones well anyone with a + + + align:start position:0% +related to this ones well anyone with a +circular orbit must be related to these + + align:start position:0% +circular orbit must be related to these + + + align:start position:0% +circular orbit must be related to these +solutions by first forming a + + align:start position:0% +solutions by first forming a + + + align:start position:0% +solutions by first forming a +superposition of those solutions maybe + + align:start position:0% +superposition of those solutions maybe + + + align:start position:0% +superposition of those solutions maybe +localizing it or doing something and + + align:start position:0% +localizing it or doing something and + + + align:start position:0% +localizing it or doing something and +then doing engage transformation so in + + align:start position:0% +then doing engage transformation so in + + + align:start position:0% +then doing engage transformation so in +order to compare your solution + + align:start position:0% +order to compare your solution + + + align:start position:0% +order to compare your solution +in different gauges you have to take + + align:start position:0% +in different gauges you have to take + + + align:start position:0% +in different gauges you have to take +into account you have an infant in + + align:start position:0% +into account you have an infant in + + + align:start position:0% +into account you have an infant in +degeneracy and you have gauge + + align:start position:0% +degeneracy and you have gauge + + + align:start position:0% +degeneracy and you have gauge +transformation so to see what state here + + align:start position:0% +transformation so to see what state here + + + align:start position:0% +transformation so to see what state here +corresponds to a particular state here + + align:start position:0% +corresponds to a particular state here + + + align:start position:0% +corresponds to a particular state here +it may be the gauge transformation of a + + align:start position:0% +it may be the gauge transformation of a + + + align:start position:0% +it may be the gauge transformation of a +particular superposition in this side so + + align:start position:0% +particular superposition in this side so + + + align:start position:0% +particular superposition in this side so +it's in general not all that easy to do + + align:start position:0% +it's in general not all that easy to do + + + align:start position:0% +it's in general not all that easy to do +okay so let's take of count state in a + + align:start position:0% +okay so let's take of count state in a + + + align:start position:0% +okay so let's take of count state in a +finite sample sum so same picture but + + align:start position:0% +finite sample sum so same picture but + + + align:start position:0% +finite sample sum so same picture but +now the material is here and we'll put + + align:start position:0% +now the material is here and we'll put + + + align:start position:0% +now the material is here and we'll put +LX and ly here so finite size in a legs + + align:start position:0% +LX and ly here so finite size in a legs + + + align:start position:0% +LX and ly here so finite size in a legs +finite size in ly so given our intuition + + align:start position:0% +finite size in ly so given our intuition + + + align:start position:0% +finite size in ly so given our intuition +with quantization this suggests that we + + align:start position:0% +with quantization this suggests that we + + + align:start position:0% +with quantization this suggests that we +impose periodic boundary conditions in X + + align:start position:0% +impose periodic boundary conditions in X + + + align:start position:0% +impose periodic boundary conditions in X +and try to quantize the KX here in + + align:start position:0% +and try to quantize the KX here in + + + align:start position:0% +and try to quantize the KX here in +general if you're imposing thinking of + + align:start position:0% +general if you're imposing thinking of + + + align:start position:0% +general if you're imposing thinking of +very large boxes which is the case here + + align:start position:0% +very large boxes which is the case here + + + align:start position:0% +very large boxes which is the case here +it doesn't matter much whether you + + align:start position:0% +it doesn't matter much whether you + + + align:start position:0% +it doesn't matter much whether you +impose periodic or vanishing boundary + + align:start position:0% +impose periodic or vanishing boundary + + + align:start position:0% +impose periodic or vanishing boundary +conditions or anything essentially at + + align:start position:0% +conditions or anything essentially at + + + align:start position:0% +conditions or anything essentially at +large number of states it makes no + + align:start position:0% +large number of states it makes no + + + align:start position:0% +large number of states it makes no +difference + + align:start position:0% +difference + + + align:start position:0% +difference +so we quantize in X so we want e to the + + align:start position:0% +so we quantize in X so we want e to the + + + align:start position:0% +so we quantize in X so we want e to the +I I KX times X to be periodic under X + + align:start position:0% +I I KX times X to be periodic under X + + + align:start position:0% +I I KX times X to be periodic under X +goes to X plus LX + + align:start position:0% +goes to X plus LX + + + align:start position:0% +goes to X plus LX +I'm almost done with Sun so KX LX + + align:start position:0% +I'm almost done with Sun so KX LX + + + align:start position:0% +I'm almost done with Sun so KX LX +will have to be equal to a multiple with + + align:start position:0% +will have to be equal to a multiple with + + + align:start position:0% +will have to be equal to a multiple with +MX since we know that + + align:start position:0% +MX since we know that + + + align:start position:0% +MX since we know that +why naught is equal to minus KX l B + + align:start position:0% +why naught is equal to minus KX l B + + + align:start position:0% +why naught is equal to minus KX l B +squared we should take an x- so that + + align:start position:0% +squared we should take an x- so that + + + align:start position:0% +squared we should take an x- so that +you're within the sample you must be in + + align:start position:0% +you're within the sample you must be in + + + align:start position:0% +you're within the sample you must be in +Y positive and therefore KX should be + + align:start position:0% +Y positive and therefore KX should be + + + align:start position:0% +Y positive and therefore KX should be +negative and X should be negative and + + align:start position:0% +negative and X should be negative and + + + align:start position:0% +negative and X should be negative and +now I have a way to count because I can + + align:start position:0% +now I have a way to count because I can + + + align:start position:0% +now I have a way to count because I can +take an X negative up to some value + + align:start position:0% +take an X negative up to some value + + + align:start position:0% +take an X negative up to some value +minus NX bar and when NX grows + + align:start position:0% +minus NX bar and when NX grows + + + align:start position:0% +minus NX bar and when NX grows +KX grows and Y grow so I can take the + + align:start position:0% +KX grows and Y grow so I can take the + + + align:start position:0% +KX grows and Y grow so I can take the +last NX that I can use is the one in + + align:start position:0% +last NX that I can use is the one in + + + align:start position:0% +last NX that I can use is the one in +which the orbit is still in the sample + + align:start position:0% +which the orbit is still in the sample + + + align:start position:0% +which the orbit is still in the sample +up to the value y naught so this is this + + align:start position:0% +up to the value y naught so this is this + + + align:start position:0% +up to the value y naught so this is this +number is really the degeneracy because + + align:start position:0% +number is really the degeneracy because + + + align:start position:0% +number is really the degeneracy because +this is how many values of NX I can have + + align:start position:0% +this is how many values of NX I can have + + + align:start position:0% +this is how many values of NX I can have +from minus NX up to zero are the number + + align:start position:0% +from minus NX up to zero are the number + + + align:start position:0% +from minus NX up to zero are the number +of values that are consistent with a + + align:start position:0% +of values that are consistent with a + + + align:start position:0% +of values that are consistent with a +state still in the sample so why not + + align:start position:0% +state still in the sample so why not + + + align:start position:0% +state still in the sample so why not +equal to L Y should be equal to minus KX + + align:start position:0% +equal to L Y should be equal to minus KX + + + align:start position:0% +equal to L Y should be equal to minus KX +times L B squared so it's minus 2 pi NX + + align:start position:0% +times L B squared so it's minus 2 pi NX + + + align:start position:0% +times L B squared so it's minus 2 pi NX +bar over LX x lb squared and this gives + + align:start position:0% +bar over LX x lb squared and this gives + + + align:start position:0% +bar over LX x lb squared and this gives +you an X we can solve for an X there MX + + align:start position:0% +you an X we can solve for an X there MX + + + align:start position:0% +you an X we can solve for an X there MX +is ly L x over L B squared over 1 over 2 + + align:start position:0% +is ly L x over L B squared over 1 over 2 + + + align:start position:0% +is ly L x over L B squared over 1 over 2 +pi so NX is the degeneracy this is the + + align:start position:0% +pi so NX is the degeneracy this is the + + + align:start position:0% +pi so NX is the degeneracy this is the +degeneracy and it's equal to the + + align:start position:0% +degeneracy and it's equal to the + + + align:start position:0% +degeneracy and it's equal to the +area / lb square which is H bar C over + + align:start position:0% +area / lb square which is H bar C over + + + align:start position:0% +area / lb square which is H bar C over +QB times 1 over 2 pi so it's equal to + + align:start position:0% +QB times 1 over 2 pi so it's equal to + + + align:start position:0% +QB times 1 over 2 pi so it's equal to +area times B divided by 2 pi H bar C + + align:start position:0% +area times B divided by 2 pi H bar C + + + align:start position:0% +area times B divided by 2 pi H bar C +over cube so we're back to the kind of + + align:start position:0% +over cube so we're back to the kind of + + + align:start position:0% +over cube so we're back to the kind of +thing we were saying before in which the + + align:start position:0% +thing we were saying before in which the + + + align:start position:0% +thing we were saying before in which the +degeneracy degeneracy is equal to the + + align:start position:0% +degeneracy degeneracy is equal to the + + + align:start position:0% +degeneracy degeneracy is equal to the +flux divided by the flux quantum that we + + align:start position:0% +flux divided by the flux quantum that we + + + align:start position:0% +flux divided by the flux quantum that we +figured out earlier today so this is how + + align:start position:0% +figured out earlier today so this is how + + + align:start position:0% +figured out earlier today so this is how +much how much states you can put on the + + align:start position:0% +much how much states you can put on the + + + align:start position:0% +much how much states you can put on the +sample so you find you're given a + + align:start position:0% +sample so you find you're given a + + + align:start position:0% +sample so you find you're given a +magnetic field at Tesla and you have + + align:start position:0% +magnetic field at Tesla and you have + + + align:start position:0% +magnetic field at Tesla and you have +some area you find the Phi u divided by + + align:start position:0% +some area you find the Phi u divided by + + + align:start position:0% +some area you find the Phi u divided by +Phi naught and that's the number of + + align:start position:0% +Phi naught and that's the number of + + + align:start position:0% +Phi naught and that's the number of +degenerate states of each Landau level + + align:start position:0% +degenerate states of each Landau level + + + align:start position:0% +degenerate states of each Landau level +so in particular given that we have that + + align:start position:0% +so in particular given that we have that + + + align:start position:0% +so in particular given that we have that +number that Phi naught is equal to about + + align:start position:0% +number that Phi naught is equal to about + + + align:start position:0% +number that Phi naught is equal to about +2 times 10 to the minus 7 Gauss then + + align:start position:0% +2 times 10 to the minus 7 Gauss then + + + align:start position:0% +2 times 10 to the minus 7 Gauss then +centimeter squared if you have a sample + + align:start position:0% +centimeter squared if you have a sample + + + align:start position:0% +centimeter squared if you have a sample +of 1 centimeter squared and you put one + + align:start position:0% +of 1 centimeter squared and you put one + + + align:start position:0% +of 1 centimeter squared and you put one +Gauss the value of the flux over Phi + + align:start position:0% +Gauss the value of the flux over Phi + + + align:start position:0% +Gauss the value of the flux over Phi +naught would be 1 Gauss centimeter + + align:start position:0% +naught would be 1 Gauss centimeter + + + align:start position:0% +naught would be 1 Gauss centimeter +squared over 2 times 10 to the minus 7 + + align:start position:0% +squared over 2 times 10 to the minus 7 + + + align:start position:0% +squared over 2 times 10 to the minus 7 +same units so it's about five million + + align:start position:0% +same units so it's about five million + + + align:start position:0% +same units so it's about five million +states that's just to give you an idea + + align:start position:0% +states that's just to give you an idea + + + align:start position:0% +states that's just to give you an idea +of how big the numbers are that's the + + align:start position:0% +of how big the numbers are that's the + + + align:start position:0% +of how big the numbers are that's the +degeneracy + + align:start position:0% + + + + align:start position:0% + +so this is a classic problem very + + align:start position:0% +so this is a classic problem very + + + align:start position:0% +so this is a classic problem very +important in condensed matter physics is + + align:start position:0% +important in condensed matter physics is + + + align:start position:0% +important in condensed matter physics is +the first step in trying to understand + + align:start position:0% +the first step in trying to understand + + + align:start position:0% +the first step in trying to understand +quantum Hall effect and and many things + + align:start position:0% +quantum Hall effect and and many things + + + align:start position:0% +quantum Hall effect and and many things +and it's important to solve it and think + + align:start position:0% +and it's important to solve it and think + + + align:start position:0% +and it's important to solve it and think +it in several ways and I think you will + + align:start position:0% +it in several ways and I think you will + + + align:start position:0% +it in several ways and I think you will +be doing that in homework and recitation \ No newline at end of file diff --git a/VTWmccDMlDw.txt b/VTWmccDMlDw.txt new file mode 100644 index 0000000000000000000000000000000000000000..1dd2533a83e498db887218ef738bbb7f2db4b31d --- /dev/null +++ b/VTWmccDMlDw.txt @@ -0,0 +1,1311 @@ +Thanksgivings. We're talking today about rational + +medicine, and really what we're talking about is an understanding of + +the molecular biology of disease has actually helped to revolutionize the + +new science of therapeutic medicine. And here, more often than not, the + +discussions are focused around cancer. And so, + +I will therefore talk about an interesting story, + +vis-à-vis the modern treatment of cancer, and how our understanding of + +the molecular biology of the disease really helps in developing radically + +new kinds of therapies. By way of background, + +let's just mention that most of the chemotherapeutics that we use today + +to treat cancer were developed over the last 40-50 years at a time when + +the molecular and biochemical defects inside cancer cells + +were totally obscure. And therefore, + +to the extent that one developed chemotherapeutics, + +they were developed simply empirically, trial and error. + +For example, some of the most effective chemotherapeutics against + +childhood leukemia are alkylating agents, + + which attach methyl and ethyl groups + +to target molecules inside cells. And their utility in cancer was + +first discerned because of an explosion in a container. + +I think it was in a ship off Naples in World War II where a bin of + +alkylating agents was dispersed. Many people were exposed to it, and + +these people, as a consequence of that, came down with what's + +called leucopoenia. Poenia generally means a depression, + +in this case, a depression of their white blood cells. + +Such alkylating agents had actually been used during the First World War + +in gas warfare because during the First World War, + +one used so-called mustard gases, which was a very effective way, even + +more effective than artillery in killing vast numbers + +of enemy soldiers. And, somebody noticed this + +leucopoenia in 1946-47 as a consequence of inadvertent exposure + +to these alkylating agents, which became dispersed as a gas. + +And about five years later, somebody made the logical leap that + +if these agents were able to suppress normal white blood + +concentrations that perhaps they might also be effective against what + +seemed to be ostensibly a related problem, which is the problem + +of leukemia. And keep in mind that when we talk + +about leukemia, the suffix -emia refers to blood + +generally, and leuk- once again refers to white blood, + +i.e. an excess of white blood cells in the blood. And so, + +through this accidental discovery, one began to develop alkylating + +agents that turned out to be extremely successful in treating, + +and often curing, childhood leukemias, most notably acute + +lymphocytic leukemia, which turns out to be very sensitive + +to this and other related agents. So, this is a very common form of + +childhood leukemia, which is now actually cured in 60 or + +70% of the children who were treated, which would have been unheard of + +half a century ago. But I return to what I said before, + +which is that this kind of treatment was developed in the face of total + +ignorance concerning the nature of the disease, the molecular defects + +that were present in the disease, and that were responsible for the + +runaway, can you still hear me OK, were responsible for the runaway + +proliferation of the cancer cells. So having said that, + +I want to go to a different kind of leukemia, and this is called chronic + +myelogenous leukemia, to give you an indication of the + +path of discovery that led from its original description to the + +development of rather successful treatments. + +So, chronic myelogenous leukemia, I mentioned the prefix myelo- last + +time or the time before referring to bone marrow, and this is a leukemia + +of cells coming from the bone marrow from the myeloid cells in the bone + +marrow, which are the precursors of things like macrophages + +and granulocytes. So, these are cells which are + +playing an important role in the immune response, + +and during this chronic myelogenous leukemia disease, + +which is called CML, there could be a period of three or + +four years where individuals develop large numbers of these cells in + +their blood stream. And after a period of about three or + +four years, all of a sudden there is an eruption into what's called blast + +crisis. And you may recall I mentioned the word blast also on one + +occasion earlier. This all fits together in a nice + +puzzle. Blast refers to primitive, embryonic-like cells, and all of a + +sudden there is an eruption of primitive, embryonic-like cells, + +less differentiated like these macrophages and granulocytes, + +which until this point had been present in vastly excessive numbers + +in the blood. There's blast crisis. + +This leads to acute myelogenous leukemia, and death ensues usually + +within a year or two, or that's been traditionally the + +case. No one really had any idea about the possible causative + +mechanisms of the disease, and that allows me to use another + +word which you might one day come across if you should stay in + +biomedical research. And that is the etiologic agents. + +When we talk about etiologic agents, we talk about the agents which are + +causally responsible for inducing a disease. These can be external + +agents, or they could even be internal agents, + +molecules inside cells which are responsible for the creation of the + +disease. And the key discovery was made in 1960 when individuals were + +looking at the chromosomal makeup of the CML cells. + +The chromosomal makeup, I'll use another word just so we + +could expand our vocabulary this morning, the chromosomal makeup is + +often called the karyotype, that is to say the constellation of + +chromosomes that one can see at mitosis under the microscope. + +Keep in mind, as we've said before, that during the interphase of the + +cell cycle, chromosomes are essentially invisible, + +but during the metaphase of mitosis they become condensed, + +and on that occasion, individuals noticed a 9-22 translocation. + +So here is chromosome nine normally. Here's chromosome 22. And as you + +may know, the numbering system with human chromosomes goes from the + +largest number one all the way down to the smallest. + +So, this is the smallest, with the exception of the Y + +chromosome. And what they notice was instead of + +seeing this regular chromosomal array, they noticed instead what + +looked very much like a structure of this sort here, i.e. + +a translocation. + +And this translocation resulted in a swapping of sequences between these + +two chromosomes. Note, by the way, + +this is reciprocal, i.e. in the sense that nine donates + +something to 22, and 22 donates something to nine. + +However, the segments that are swapped are not necessarily of equal + +size. So, it turns out here that in this case, chromosome nine has + +actually gained a lot more than chromosome 22 gained as a + +consequence of this exchange of genetic segments. + +And this 9-22 translocation made the smallest chromosome even smaller. + +So, this was already the smallest chromosome as I mentioned besides + +the smallest autosome, the smallest non-sex chromosome. + +Now it got even smaller because it lost some of its bulk as a + +consequence of this chromosomal translocation. + +And because this discovery was made in Philadelphia, + +it became known as the Philadelphia chromosome. This is now about 40 + +years ago, or as it's sometimes called, PH-1 for reasons, + +I don't know why it's called PH-1 except for Philadelphia. + +And, as investigators began to look at other cases of chronic + +myelogenous leukemia, they discovered that this + +translocation was present at the Philadelphia chromosome most + +importantly was identifiable in virtually all cases, + +more than 95% of the cases of chronic myelogenous leukemia. + +And moreover, this chromosome was present as well in the more + +differentiated macrophages and granulocytes that were present and + +circulating in the blood of the CML patients. And that began to suggest + +the notion that there was a stem cell of some sort, + +oligopotential stem cell that created various kinds of more + +differentiated white blood cells that had sustained this chromosomal + +translocation because that's what it is, a translocalization, + +a translocation, that all the cells of these patients had sustained this + +chromosomal translocation. And that began to suggest the + +notion that somehow as a consequence of a random genetic accident + +happening in these people's blood, this particular chromosome was + +repeatedly identified. And it was with great likelihood + +causally or etiologically important in the genesis of the disease. + +But that in itself led nowhere. One could simply talk about its + +association until work from a totally unrelated area, + +which is to say the study of retroviruses discovered Abelson + +murine leukemia virus. And Abelson was named after the + +fellow, Herb Abelson, who first discovered it at NIH and + +undertook its molecular characterization here in our own + +cancer center, and Abelson discovered that this + +virus which he studied carried the ends of the murine leukemia virus, + +which was a parental virus. It was as hybrid virus. + +And into the middle of it, Abelson leukemia virus has acquired + +a cellular proto-oncogene, which it had activated into an + +oncogene. And therefore, here we have a situation where a + +cellular gene like sarc in the case of Rous Sarcoma Virus has been + +activated. This became called ABL for obvious reasons. + +And this gene, it turned out, was critically important in + +understanding hwo the chromosomal translocation led to cancer. + +In fact, if one infected mice with a retrovirus carrying this genome, + +this is just to indicate the fact that the repeat ends, + +the long terminal repeat ends of this provirus, + +they occur twice at the ends of this retrovirus. If one infected a mouse + +with the Abelson virus, out came a disease which was + +superficially similar at least to chronic myelogenous leukemia. + +And that began a search, then, for the chromosomal + +localization of the Abel proto-oncogene. + +And what was discovered subsequently, fascinatingly enough, + +was that the Abel proto-oncogene was right at the break point between two + +chromosomes, nine and 22. And what happened as a consequence + +of this translocation, and the resulting fusion of this + +chromosome with this chromosome was the creation of a fuse gene, + +a hybrid gene that now carried the reading frames of two previously + +unconnected gene, one on chromosome nine, + +and one on chromosome 22. Here's the normal, Abel protein. + +It's called C Abel, meaning the cellular or the normal form of Abel. + +And you see it up here. It's shown in a very schematic way. + +And here's a second protein which is encoded on the other chromosome. + +So, Abel is encoded here, and the other gene, which is called BCR is + +encoded here, and as a consequence of the translocation, + +Abel is encoded here. BCR is encoded here. As a consequence of + +the translocation, one now has not only the fusion of + +chromosomal segments. But one has the fusion of the + +reading frames of two previously unlinked genes. + +And here, one creates as a consequence of these fusions, + +any one of a series of three quite distinct fusion proteins, + +which do not naturally preexist in the normal cell. + +And there shown here is P-1 85, P-2 10, and P-2 30. These + +translocations allow different parts of a second gene called BCR. + +BCR refers to breakpoint cluster region. The area of the point of + +fusion is called the breakpoint between the two genes. + +So, the point where each gene is cut and fused with the other is + +called the breakpoint. And it turns out that within the + +region of the chromosome where BCR maps, there's actually three sites + +at which the fusion can occur. If you look carefully at this + +diagram, you see that there's differing extents of the BCR protein, + +which can be contributed to the fusion protein. + +And, what this says, in effect, is the following, + +that here, let's just refer to this diagram right up here. + +Notice, by the way, in all three of these, that the Abel protein is + +present at the C terminal end of the protein. The BCR is present at the + +end terminal end. So, here's the BCR gene. + +Here's the Abel gene down here. And what investigators found is that + +there could be a break at this part of the BCR gene, + +at this part of the BCR gene, or at this part of the BCR gene, + +resulting always in the fusion of Abel, to one, or two, + +or three different kinds of BCR proteins. And, + +breakpoint cluster region signified the fact that there was a whole + +cluster of sites in the previously existing BCR gene to which this + +fusion could take place, resulting, if the break occurred + +here, the breakpoint occurred here, and BCR to get the longer one. + +Here you get the medium-sized one; here you'd get the shortest one. + +And, interestingly enough, as one explored virtually, + +other kinds of different leukemias, one could see different of these + +fusion proteins that were produced. Here's chronic, myelogenous + +leukemia, which I talked to you about before. Here is acute + +lymphocytic leukemia, and here's chronic and neutrophylic + +leukemia, three different kinds of leukemia. We don't have to worry + +about the details of these diseases, aside from the fact to say that the + +structure of this fusion protein encourages the outgrowth of + +different kinds of stem cells in the bone marrow, which in turn create + +three different kinds of diseases. Most importantly for our discussion + +was an attempt to understand the nature of the resulting fusion + +protein, which as a consequence of this fusion caused by the + +chromosomal translocation now clearly acquired biological powers + +that did not preexist in either of the two parental proteins. + +These various notations here indicate a whole series of different + +functions which are associated with the Abel protein, + +and alternatively with the BCR protein. And we don't need to get + +into them, except to say that each one of these different names here + +allows the protein on its own to associate with other proteins and do + +activated downstream signaling cascade. + +What's most important about our discussion is the realization that + +this SH-1 domain, indicated here, SH-1 refers to the + +sarcomology domain, equals sarcomology, equals a + +tyrosine kinase. And therefore, what one has here is + +a protein, which is much more elaborate than sarc, + +has vastly more signaling capabilities, + +by virtue of the fact that these different domains that are indicated + +here allow the resulting fusion protein to grab hold of a whole + +bunch of different signally partners so that it can send out a diverse + +array of downstream activating signals. If one examined the + +structure of the SH-1 domain, it had a tyrosine kinase activity + +very much like sarc, and most importantly, + +if one introduced this fusion protein into a retrovirus, + +now instead of Abel, one could make a BCR Abel fusion protein. + +One could put this into a retrovirus as before, just like up here. + +One could infect mice with it, and now get out of a disease which + +was indistinguishable, in essence, from chronic myelogenous + +leukemia in humans. If one put a subtle point mutation + +in the tyrosine kinase domain, all of the able protein, here is the + +tyrosine kinase domain, SH-1, up here. Here, we see the + +tyrosine kinase domains represented in the three different fusion + +proteins. Keep in mind SH-1 is always the tyrosine kinase domain. + +If one put a subtle, inactivating point mutation in the tyrosine + +kinase domain, that immediately wiped out all + +biological powers of creating leukemias on the part of this + +retrovirus here, or any one of the other closely + +related kinds of fusion proteins. And therefore, + +that indicated that the tyrosine kinase domain indicated right here + +was really critical to creating the tumor, and that any effects on its + +tyrosine kinase signaling ability would, in the end, + +result in the collapse of the tumor, or the inability of the resulting + +retrovirus to actually create cancer. + +And so, now one had, really for the first time, + +a clear demonstration of how a commonly occurring human cancer, + +chronic myelogenous leukemia, is unfortunately not so rare, + +could arise as a consequence of some random, chromosomal translocation + +event. You might ask, why does one always get this + +particular kind of translocation? Well, the answer is, we don't + +really know. It would almost seem as if there's a homing device which + +causes this fragment and this fragment to target each other and to + +exchange one another. It's probably not the case. + +What probably happens is that chromosomal translocations take + +place rather randomly within the bone marrow, and on rare occasion + +there is a chromosomal translocation that creates exactly this kind of + +fusion. And this kind of fusion, in turn, is what's responsible for + +creating this fusion protein, and this fusion protein in turn + +creates the outgrowth of this CML, the chronic myelogenous leukemia + +disease. So what that means is really that a + +randomly occurring chromosomal translocation on rare occasion hits + +a genetic jackpot, and the cell which happens to have + +acquired this kind of chromosomal translocation now begins to + +proliferate wildly, creating first chronic myelogenous + +leukemia, and then subsequently erupting into a subsequent acute + +phase where there are seemingly additional genetic alterations + +beyond this chromosomal translocation that conspire with the + +initially present chromosomal translocation to create a very + +aggressive disease which rapidly leads to the death of the + +leukemia patient. That offered, in principle, + +an attractive way of beginning to develop an anti-cancer therapeutic + +because what one might imagine was that one could develop a tyrosine + +kinase inhibitor. + +Now keep in mind that tyrosine kinases are a class of enzymes which + +attach phosphate groups onto the tyrosine residues of various + +substrate proteins. And keep in mind as well the fact + +that we drew a series of growth factor receptors which have tyrosine + +kinase domains in them. And I'm drawing the tyrosine kinase + +domains here like this, that when these growth factor + +receptors become activated, they attach phosphate groups onto + +the tails of one another. And I'll draw those phosphate + +groups like this, i.e. the binding of ligand or let's + +say epidermal growth factor ligand or plate ligand causes the two + +receptors, which are normally mobilized in the plasma membrane to + +come together to transphosphorylate one another, + +and having done so, to acquire actively signaling powers, + +because once these phosphates become attached, they now represent sites + +where other molecules can anchor themselves and send out downstream + +signals. In fact, there are altogether 90 different + +tyrosine kinases encoded in the human genome. + +And so, to the extent that these tyrosine kinases become + +hyperactivated in various kinds of human cancers, + +this represents in principle a very attractive way of developing an + +anti-cancer therapeutic. But let's think about the problems + +that are inherent in such a compound. First of all, + +if one wants to develop an anti-cancer therapeutic, + +it must be reasonably specific for the Abelson tyrosine kinase, + +and not the 89 kinds of tyrosine kinases that also coexist in the + +human genome, and are active, and apparently responsible for + +normal cell metabolism in a whole variety of normal cell types. + +So, one has to begin to think about the issue of cell activity. + +How can one possibly make a low molecular weight compound, + +which is selectively able to inactivate the Abelson tyrosine + +kinase as indicated here, the SH-1 group, + +but doesn't disturb a whole variety of other tyrosine kinases that are + +responsible for other normal physiological mechanisms. + +Well, you'll say that's pretty easy. We have 90 different genes. + +Each of the 90 different genes makes a distinct protein, + +and these proteins should be very different. And therefore, + +if one can, in fact, if one does the three-dimensional structure of these + +proteins, all the tyrosine kinases look quite similar. + +They have a biload structure. Here is the active site of the + +enzyme. That is to say, in here is the catalytic cleft, + +the site where the actual catalysis takes place, the site where the + +gamma phosphate of ATP is taken from the ATP and attached to a substrate + +protein to the hydroxyl of a tyrosine of a protein that's about + +to be phosphorylated. So, you just make a low moleculoid + +chemical that's specific for the tyrosine kinase domain of the Abel + +protein. And when I draw this biload structure, + +this biload structure is carried here within the SH-1 domain right + +here. So, this has a biload structure. It's obviously not + +indicated here in this very schematic drawing. + +The problem with that is the following. + +All of the SH-1 domains, all of the tyrosine kinase domains + +are evolutionarily closely related to one another. + +They're all derived from the precursors of the tyrosine kinase + +domain that probably existed maybe 600 or 700 million years ago, + +and has as a consequence of gene duplication been diversified to make + +90 different tyrosine kinases. And if you look under x-ray + +crystallography at the three dimensional structure of all these + +tyrosine kinases, they all pretty much look like this, + +i.e. they all have rather similar catalytic clefts because they + +diverge from a common ancestral protein, and they retain this three + +dimensional configuration because this three dimensional configuration + +seems to be important for the retention of their function. + +You could imagine, conversely, that if there were some descendants + +of the ancestral tyrosine kinase domain that some of them became + +mutant and lost its three dimensional structure. + +Those descendant kinases would lose their ability to phosphorylate + +tyrosines on substrate proteins, and therefore would be eliminated + +from the gene pool because they would be defective. + +And that explains the strong conservatism in the structure of + +these 90 different enzymes. They all look very similar to one + +another, and that creates a great difficulty for the drug developer + +because a low molecular weight drug, which one would like to develop, + +that fits in here. So, here I'll draw a low molecular + +weight drug that interacts in a stereo-specific fashion with the + +amino acid residues that are aligning this pocket, + +this catalytic cleft, might bind and nicely inactivate the tyrosine + +kinase domain of Abel. But at the same time, + +it might also bind and inactivate a whole series of other tyrosine + +kinases, and that in turn could lead to therapeutic disaster. + +For instance, if you had a non-selective agent, + +you could treat a chronic myelogenous leukemia patient with a + +low molecular weight inhibitor, a low molecular weight compound, + +which would get into this pocket of the BCR Abel protein. + +But it might similarly get into the catalytic cleft of the EGF receptor. + +And if it shot down the EGF receptor, it might cause a fatal + +diarrhea because after all, the EGF receptor, I will tell you, + +is needed to maintain the structure of the epithelial lining of the + +colon. And so, you might kill the patient simply + +because you had deprived the cells in that person's colon of their + +ability to maintain themselves. There are a whole series of growth + +factor receptors that are required for hematapoeisis that we discussed + +last time. And there, once again, if you had a + +nonselective compound, which got into the domain of one of + +the growth factor receptors that is responsible for hematapoeisis, + +you might shut down the entire bone marrow, and once again kill the + +patient. I'm just giving you those as overly dramatic examples of the + +fact that cell activity is an extremely important consideration in + +developing such a drug. The other thing is affinity for the + +target, for the catalytic cleft that is being targeted. + +What do I mean by affinity? If you look at those response + +curves of various compounds, what you see is the following. + +You can draw out a line that looks like this, a graph that looks like + +this, where here we have log of drug concentration. + +And here is 10-4, here, let's do the other one, + +10-8 molar, 10-7 molar, 10-6, 10-5, 10-4. + +And this is molar drug concentration. And here is the percentage of + +inhibition. Let's say, for example, we were able to take + +the BCR Abel protein and study it in a test tube. And let's say we were + +interested in studying how well its tyrosine kinase activity responded + +to an applied drug that we developed against it. + +So, here's the percentage of inhibition of tyrosine kinase + +activity of BCR Abel protein. Now, I might be able to develop a + +drug whose dose response curve would look like this. + +And you'll say, well, that's terrific. + +That's a drug which shuts down BCR Abel. We haven't even dealt with + +the issue of cell activity, but let's look at where one begins + +to see a dose response right here, 10-5 molar. And if you calculate + +back as to how much of the drug you need to deliver in order to shut + +down the BCR Abel protein in a patient, the size of the pill they'd + +have to get would probably be this big everyday. + +So, what you need to do is you need to be an acceptable range of drug + +concentrations is down in this area here. And therefore, + +only until you get a drug which has a dose response curve that looks + +like this, which is two or three orders of magnitude more potent + +where it's able to shut down the kinase activity already at 10-7 in a, + +this is called a submicromolar concentration. + +Micromolar is 10-6. Here already at a tenth of a + +micromolar, 10-7 molar, we're already getting a shutdown of + +the enzyme function. And if one can do that, + +then one might in principle be able to develop a pill that's this big + +and give that to the patient rather than a pill that's a size of a + +football. And by the way, if you have to make lots of a very + +complex, organic molecule through organic synthesis that has an + +affinity of this, it's also very expensive. + +Obviously, if you can make a compound that's a hundredfold more + +potent and requires a hundredfold less material to deliver to the + +patient body, then you might have some success in treating + +the patient. Here's another issue. + +So, we've talked about cell activity. We've talked about + +potency or affinity, affinity for the substrate or + +potency. So, this would be an acceptable drug. + +It works already at molar concentration where the inflection + +point of this curve is. This is an unacceptable drug at + +10-5. We can also talk about + +pharmacokinetics. I want to give you a feeling for + +how complex drug development is, and why it so rarely succeeds. By + +the way, you know how much it costs to develop a drug that's useful in + +the clinic these days and test it on people? Anybody have any idea? + +How much? Yeah. It's pretty close to $1 billion, + +between $900 million and $1 billion. That's a lot of money. That's more + +money than you and I are going to earn together, all of us + +maybe, in a lifetime. OK, anyhow, pharmacokinetics, + +well what's pharmacokinetics? Glad I asked that question. + +How long does the drug stay inside of you after you take it if you're a + +cancer patient? What happens if the drug is + +excreted by the kidneys within minutes of its being taken, + +let's say, either by injection or orally? + +So here we can imagine, let's talk about drug concentration. + +I'll use the word drug concentration in blood. + +And here's time. And here's what some drugs look like when you give + +them, let's say, orally. Here's what they look like. + +So, let's say here's the effective drug concentration: effective + +concentration. And we know the effective + +concentration from doing measurements like this. + +We just measure it, work that out. So, let's say we develop a drug + +which is able to hit the BCR Abel protein. What are the kinetics with + +which the drug becomes soluble in the blood stream? + +And it might look like this, where I'm drawing here now, this is + +one hour. This is two hours. This is three hours, four hours. + + Is that long enough? + +Well, the fact of the matter is, if you're going to try to kill a + +cancer cell, and that's what the name of this game is, + +you want to have it around for a while because it turns out, + +as one learned, the continued viability of the CML cancer cells of + +the leukemia cells was dependent on the continued firing by the BCR Abel + +kinase protein. In fact, as one learned, + +if one shut off firing by the tyrosine kinase molecule in a + +chronic myelogenous leukemia cell, the cells would implode. + +They would undergo apitosis. So, this began to reveal that in + +fact the BCR Abel protein is not only responsible for forcing these + +cells to proliferate, but it also independently provides + +them with anti-apoptotic signal. It keeps them from falling over the + +cliff into apitosis. It keeps them from killing + +themselves, and that's obviously critical for the ability of this + +tumor to proliferate, for the number of cells to expand in + +the body of a patient. It turns out that if you provide + +these cancer cells with an effective way of shutting down their BCR Abel + +protein for 30 or 40 or 50 minutes, not much happens to them. You need + +to deprive them of the drug for a very long period of time, + +well, 15-20 hours, and therefore you need pharmacokinetics that look like + +this. It needs to be present for an extended period of time, + +or even better, let me re-draw that, even better look like this. + +It stays in the blood for an extended period of time. + +Some drugs stay in the circulation for a long time. + +Other drugs stay in the circulation for a very short period of time. + +There's another problem which we haven't even begun to talk about, + +and that is the metabolism of the drug. It turns out that many drugs + +that you give a patient are rapidly converted by the enzymes and the + +liver which are normally responsible for detoxifying chemicals that come + +into our body. And therefore, + +many of the drugs that come into our bodies are with greater or lesser + +speed altered into something else, detoxified, and therefore rendered + +innocuous. Now you'll say, well, you can figure that out too, + +but here's an additional fly in the ointment. Because we are a + +polymorphic population, because we humans are genetically + +heterogeneous, one from the other, + +some of us metabolize a given drug much more rapidly than others do. + +And here, we have a situation where potentially, most of us might + +metabolize a drug very quickly, in which case the physicians would + +want to give us a very high dose of the drug so that we have enough of + +the drug around for a long enough period of time to do some effect. + +So let's say that 97% of us are able to metabolize the drug very + +quickly, and as a consequence, we're given a very high dosage in + +order to have some effective dosage reaching the tumor to compensate for + +the fact that much of this drug is rapidly eliminated by metabolism + +in the liver. It's inter-converted into another + +chemically innocuous compound. Well, you'll say, that's good. + +We'll just take a large dose of that compound, + +but let's think about the other 3% in the population who metabolize + +this compound very slowly. Like the other 97%, these + +individuals will be given a high dose of the drug because experience + +shows that in general, most human beings metabolize a drug + +very quickly. These individuals metabolize the + +drug very slowly, and what's going to happen to them? + +Well, they might croak. Why? Because that drug is going to be + +around in potent biologically active form for an extended period of time + +in their bodies, and might have in them a lethal + +outcome. So therefore, we have to deal with the effects of + +variability in drug metabolism, variability in metabolism because it + +turns out that different people metabolize the drug differently and + +that variability in drug metabolism is vastly greater if you compare the + +way we metabolize drugs to the way that laboratory mice metabolize + +drugs. Well, you'll say, why should we care about how + +laboratory mice metabolize this or that drug? + +Why is it important? The fact is, the first tryouts of a + +candidate drug are tried out in laboratory mice where laboratory + +mice are given a tumor, and they're injected with the drug + +to see whether the tumor begins to shrink. But if it's the case, + +if the laboratory mice metabolize a drug in a vastly different way than + +do humans, then the outcome of working with laboratory mice might + +be enormously misleading. And these are just some of the + +problems that bedevil the development of a drug. + +In any case, around 1994, at a company which was a precursor + +of Novartis, it was called Ciba-Geigy in Basel, + +Switzerland. They developed a highly specific and potent anti-Abel, + +low molecular weight compound, which came to be called Leveck. + +Or in Europe it's called Gleveck. It's also pronounced Leveck, but + +it's spelled differently. In fact, it was one of the other + +difficulties of developing this drug was the following. + +The higher ups in the drug company who were paying for this research + +wanted on repeated occasion to scrub this entire drug development + +program. Why? Because the number of cases of + +chronic myelogenous leukemia overall worldwide is relatively small. + +How many are in this country every year? I don't know, + +10 or 15,000. So, the question was, economically speaking, would the + +relatively small number of cases of this disease justify their investing + +$1 billion in the development of the drug. Maybe it would take them a + +generation to get any payback from their initial investment. + +And so, they tried time after time, time and again, to shut down this + +development program because it didn't seem to have any clear, + +long-term economic benefit. Of course, now we're not talking about + +biology. We're talking about economics, and rational economics. + +This is not avarice on their part. A drug company like that cannot go + +on spending $1 billion here and $1 billion there without at one point + +or another leading to a major financial hemorrhage. + +So, Gleveck turned out to be highly specific for the Abel kinase, + +and as it turned out, for two other kinds of kinases as well. + +Another kind of kinase is against a tyrosine kinase receptor called KIT, + +this is a receptor tyrosine kinase, and another receptor tyrosine kinase + +called the PDGF receptor, which we've also encountered in + +passing earlier. These two other growth factor + +receptors, KIT and the PDGF receptor also have tyrosine kinase domains. + +They therefore follow this overall structural plan here, + +and it turns out by evolutionary quirk that the structures of their + +tyrosine kinase domains are actually similar in certain ways to the + +tyrosine kinase domain of Abel, and therefore of BCR Abel. + +So, in fact, they didn't actually have a totally specific drug which + +would attack only one out of the 90-tyrosine kinases encoded in their + +genome. It attacked three of the 90-tyrosine kinases, + +the Abel, the KITT, and the PDGF receptor. And this might, + +on its own, have already proven to be the death nail for the protein, + +except they began to try it out for patients, and they saw some + +remarkable responses. It turned out that the great + +majority of CML patients who were treated with Gleveck at therapeutic + +concentrations ended up having a rapid remission of their chronic + +myelogenous leukemia disease, which ultimately resulted in their + +being outwardly free of the disease. This is your question of the day. + +So, Gleveck goes into the catalytic cleft of the Abel tyrosine kinase. + +It blocks the ATP binding site because keep in mind that these + +enzymes need to grab the gamma phosphate off of ATP and transfer it + +to a protein substrate, and it does so because it hydrogen + +bonds to the amino acids which are lining this catalytic cleft. + +In other words, this catalytic cleft up here is + +obviously made of amino acids, and there are hydrogen bonds which + +Gleveck can form with the amino acid resides that you're lining on both + +sides of the cleft. I should have brought you a picture + +of that. And, a similar kind of hydrogen bonding + +can occur with the amino acids that are aligning the catalytic clefts of + +the PDGF receptor and KIT, and that hydrogen bonding can occur + +already at concentrations that are submicromolar, + +less than 10-6 molar, 10-7, even sometimes 10-8 molar + +under certain conditions. So, it's a high affinity binding, + +and it's relatively specific. Only three out of the 90 different + +kinases are bound. We can do the following kind of + +experiment. If I were to add Gleveck to cells + +with BCR Abel function, this is the response that BCR Abel + +would show. Here is the response that the EGF receptor would show. + +So, if I dose the patient at this concentration of drug, + +Gleveck will shut down the BCR Abel protein. + +But it won't shut down the EGF receptor, which requires vastly + +higher concentrations of drug in order to shut down its tyrosine + +kinase domain. And right here, + +we can see what we call selectivity. The fact that this enzyme responds + +at very log drug concentration, this enzyme EGF receptor and its + +tyrosine kinase, it's a growth factor receptor once + +again, requires a vastly higher concentration drug in order to + +elicit an outcome. So, what happened to the chronic + +myelogenous leukemia patients. The great majority of them between + +70-80% had a miraculous collapse of their disease. + +In most cases, this disease could be monitored + +microscopically. One could look for the immature + +myeloid cells in their blood and see where they were previously present + +in vast numbers. They were microscopically now + +indetectable (sic). However, in those patients where the + +disease seemed to collapse, one could still use the PCR test to + +demonstrate there were residual cancer cells in their blood. + +How could one do that? Well, let's imagine that here is the PCR + +Abel fusion protein. So, here's PCR, and here's Abel + +over here. You can make PCR primers, + +one of which is specific for a PCR sequence, and the other of which is + +specific for an Abel sequence, and the only time that you'll get a + +PCR product is if these two sequences exist on the same + +messenger RNA molecule that's reverse transcribed into a CDNA. + +You could even do this genomic DNA as well, and so one can specifically + +detect using this PCR test the presence of cells which have this + +chromosomal translocation. If one of the PCR primers is against + +BCR and the other is Abel, and the distances between these two + +primers is not too far away, not more than, let's say, kilobase, + +so you get rather efficient PCR amplification. + +So, it turned out that the great majority of patients who were + +cytologically cured, cytology means a cytological + +analysis represents what you see through in microscopes. + +So these patients, if you looked at a smear of their + +blood, cytologically they were cured. But if you used PCR analysis, + +which is far more sensitive, one could detect residual cancer cells + +that might be present in one out of 105 or one out of 106 cells moving + +around in circulation, which are almost invisible if you're + +looking through a very complex mixture of cells through the light + +microscope. And so, what happened was that patients + +began to relapse, and after a period of several years, + +a number of patients began to show a restoration of their CML condition. + +In fact, in one recent European study, indicates that between 10-12% + +of the CML patients who were treated with Gleveck relapsed every year. + +What do I mean by relapse? I mean they show a resurgence of their + +disease. The disease comes back to life, and they once again + +have the disease. And interestingly enough, + +if one now looks at their cancer cells, what do you see? + +In virtually every case you see some alteration in the BCR Abel + +protein. In the great majority of instances, you see point mutations + +that affect amino acid residues lining the cavity here, + +lining the cavity of the Abel kinase protein. + +Those amino acid substitutions do not compromise the tyrosine kinase + +activity of this enzyme. But they do prevent Gleveck from + +binding, and as a consequence, now you begin to have patients whose + +tumors are no longer responsive to Gleveck. And what's happened now is + +one has developed a new generation of compounds which binds into this + +pocket even in the presence of these amino acid substitutions to retreat + +these patients. See you on Wednesday. \ No newline at end of file diff --git a/VVOazB6_D3Q.txt b/VVOazB6_D3Q.txt new file mode 100644 index 0000000000000000000000000000000000000000..136ad61fe843567bf9cb4ec41458969bd57d530b --- /dev/null +++ b/VVOazB6_D3Q.txt @@ -0,0 +1,635 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer high quality educational + + align:start position:0% +to offer high quality educational + + + align:start position:0% +to offer high quality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu hi everybody um you're in + + align:start position:0% +ocw.mit.edu hi everybody um you're in + + + align:start position:0% +ocw.mit.edu hi everybody um you're in +507 and if you look at your syllabus + + align:start position:0% +507 and if you look at your syllabus + + + align:start position:0% +507 and if you look at your syllabus +you'll find one of the things in the + + align:start position:0% +you'll find one of the things in the + + + align:start position:0% +you'll find one of the things in the +front page of your syllabus is called a + + align:start position:0% +front page of your syllabus is called a + + + align:start position:0% +front page of your syllabus is called a +lexicon + + align:start position:0% +lexicon + + + align:start position:0% +lexicon +um and I'd like to introduce you to why + + align:start position:0% +um and I'd like to introduce you to why + + + align:start position:0% +um and I'd like to introduce you to why +um we've chosen to have a lexicon for + + align:start position:0% +um we've chosen to have a lexicon for + + + align:start position:0% +um we've chosen to have a lexicon for +this course so if you look at this + + align:start position:0% +this course so if you look at this + + + align:start position:0% +this course so if you look at this +particular slide or overhead this is + + align:start position:0% +particular slide or overhead this is + + + align:start position:0% +particular slide or overhead this is +what John is going to teach you this + + align:start position:0% +what John is going to teach you this + + + align:start position:0% +what John is going to teach you this +semester introduct metabolism the + + align:start position:0% +semester introduct metabolism the + + + align:start position:0% +semester introduct metabolism the +glycolysis pathway fatty acid + + align:start position:0% +glycolysis pathway fatty acid + + + align:start position:0% +glycolysis pathway fatty acid +biosynthesis fatty acid oxidation amino + + align:start position:0% +biosynthesis fatty acid oxidation amino + + + align:start position:0% +biosynthesis fatty acid oxidation amino +acid + + align:start position:0% +acid + + + align:start position:0% +acid +metabolism a complete jungle how are you + + align:start position:0% +metabolism a complete jungle how are you + + + align:start position:0% +metabolism a complete jungle how are you +ever going to learn anything out of this + + align:start position:0% +ever going to learn anything out of this + + + align:start position:0% +ever going to learn anything out of this +myth well it's that's actually exactly + + align:start position:0% +myth well it's that's actually exactly + + + align:start position:0% +myth well it's that's actually exactly +the point so what we're going to do over + + align:start position:0% +the point so what we're going to do over + + + align:start position:0% +the point so what we're going to do over +the course of this semester is convince + + align:start position:0% +the course of this semester is convince + + + align:start position:0% +the course of this semester is convince +you that all of this mess can be um + + align:start position:0% +you that all of this mess can be um + + + align:start position:0% +you that all of this mess can be um +simplified to 10 basic reactions and + + align:start position:0% +simplified to 10 basic reactions and + + + align:start position:0% +simplified to 10 basic reactions and +those 10 basic + + align:start position:0% +those 10 basic + + + align:start position:0% +those 10 basic +reactions are what's in the Lexicon so + + align:start position:0% +reactions are what's in the Lexicon so + + + align:start position:0% +reactions are what's in the Lexicon so +it turns + + align:start position:0% +it turns + + + align:start position:0% +it turns +out all of biochemistry um for primary + + align:start position:0% +out all of biochemistry um for primary + + + align:start position:0% +out all of biochemistry um for primary +metabolism + + align:start position:0% +metabolism + + + align:start position:0% +metabolism +can be described using 10 different sets + + align:start position:0% +can be described using 10 different sets + + + align:start position:0% +can be described using 10 different sets +of reactions and vitam your vitamin + + align:start position:0% +of reactions and vitam your vitamin + + + align:start position:0% +of reactions and vitam your vitamin +bottle and so if you look at your + + align:start position:0% +bottle and so if you look at your + + + align:start position:0% +bottle and so if you look at your +vitamin bottle what do you see most of + + align:start position:0% +vitamin bottle what do you see most of + + + align:start position:0% +vitamin bottle what do you see most of +you probably take vitamins you have + + align:start position:0% +you probably take vitamins you have + + + align:start position:0% +you probably take vitamins you have +vitamin B1 vitamin B2 vitamin B3 vitamin + + align:start position:0% +vitamin B1 vitamin B2 vitamin B3 vitamin + + + align:start position:0% +vitamin B1 vitamin B2 vitamin B3 vitamin +B6 vitamin B12 all of those um provide + + align:start position:0% +B6 vitamin B12 all of those um provide + + + align:start position:0% +B6 vitamin B12 all of those um provide +enzymes the catalysts for all the + + align:start position:0% +enzymes the catalysts for all the + + + align:start position:0% +enzymes the catalysts for all the +reactions in these this complex + + align:start position:0% +reactions in these this complex + + + align:start position:0% +reactions in these this complex +metabolic pathway I showed you um on the + + align:start position:0% +metabolic pathway I showed you um on the + + + align:start position:0% +metabolic pathway I showed you um on the +previous slide um they expand the + + align:start position:0% +previous slide um they expand the + + + align:start position:0% +previous slide um they expand the +repertoire of + + align:start position:0% +repertoire of + + + align:start position:0% +repertoire of +reactions um that enzymes can actually + + align:start position:0% +reactions um that enzymes can actually + + + align:start position:0% +reactions um that enzymes can actually +catalyze and So within the Lexicon what + + align:start position:0% +catalyze and So within the Lexicon what + + + align:start position:0% +catalyze and So within the Lexicon what +we're going to show you is the chemistry + + align:start position:0% +we're going to show you is the chemistry + + + align:start position:0% +we're going to show you is the chemistry +of actually how these vitamins work so + + align:start position:0% +of actually how these vitamins work so + + + align:start position:0% +of actually how these vitamins work so +again if we come back to the Lexicon um + + align:start position:0% +again if we come back to the Lexicon um + + + align:start position:0% +again if we come back to the Lexicon um +we'll talk about how carbon carbon bonds + + align:start position:0% +we'll talk about how carbon carbon bonds + + + align:start position:0% +we'll talk about how carbon carbon bonds +are made and broken fatty acid + + align:start position:0% +are made and broken fatty acid + + + align:start position:0% +are made and broken fatty acid +metabolism um sugar metabolism we'll + + align:start position:0% +metabolism um sugar metabolism we'll + + + align:start position:0% +metabolism um sugar metabolism we'll +talk about oxidation reduction reactions + + align:start position:0% +talk about oxidation reduction reactions + + + align:start position:0% +talk about oxidation reduction reactions +and the vitamins that are used for that + + align:start position:0% +and the vitamins that are used for that + + + align:start position:0% +and the vitamins that are used for that +transformation we'll talk about the + + align:start position:0% +transformation we'll talk about the + + + align:start position:0% +transformation we'll talk about the +energy storage and the energy currency + + align:start position:0% +energy storage and the energy currency + + + align:start position:0% +energy storage and the energy currency +in the cell ATP Etc so what the Lexicon + + align:start position:0% +in the cell ATP Etc so what the Lexicon + + + align:start position:0% +in the cell ATP Etc so what the Lexicon +is meant to do is sort of be an aid when + + align:start position:0% +is meant to do is sort of be an aid when + + + align:start position:0% +is meant to do is sort of be an aid when +you can't remember what does oxidation + + align:start position:0% +you can't remember what does oxidation + + + align:start position:0% +you can't remember what does oxidation +and reduction you can go back to your + + align:start position:0% +and reduction you can go back to your + + + align:start position:0% +and reduction you can go back to your +Lexicon and look up what are the Redux + + align:start position:0% +Lexicon and look up what are the Redux + + + align:start position:0% +Lexicon and look up what are the Redux +co-actors that are involved in + + align:start position:0% +co-actors that are involved in + + + align:start position:0% +co-actors that are involved in +transformation and by practicing the + + align:start position:0% +transformation and by practicing the + + + align:start position:0% +transformation and by practicing the +chemistry in the first part of the + + align:start position:0% +chemistry in the first part of the + + + align:start position:0% +chemistry in the first part of the +semester of all these reactions + + align:start position:0% +semester of all these reactions + + + align:start position:0% +semester of all these reactions +metabolism should be very + + align:start position:0% +metabolism should be very + + + align:start position:0% +metabolism should be very +straightforward in terms of all the cond + + align:start position:0% +straightforward in terms of all the cond + + + align:start position:0% +straightforward in terms of all the cond +activities so um what hopefully what you + + align:start position:0% +activities so um what hopefully what you + + + align:start position:0% +activities so um what hopefully what you +will do is look through your Lexicon + + align:start position:0% +will do is look through your Lexicon + + + align:start position:0% +will do is look through your Lexicon +tonight see what these reactions are and + + align:start position:0% +tonight see what these reactions are and + + + align:start position:0% +tonight see what these reactions are and +then keep it by your side during the + + align:start position:0% +then keep it by your side during the + + + align:start position:0% +then keep it by your side during the +rest of the semester and when you're + + align:start position:0% +rest of the semester and when you're + + + align:start position:0% +rest of the semester and when you're +having trouble understanding some + + align:start position:0% +having trouble understanding some + + + align:start position:0% +having trouble understanding some +chemical transformation you can use the + + align:start position:0% +chemical transformation you can use the + + + align:start position:0% +chemical transformation you can use the +Lexicon as a GU guide to think about the + + align:start position:0% +Lexicon as a GU guide to think about the + + + align:start position:0% +Lexicon as a GU guide to think about the +chemical Transformations that you'll be + + align:start position:0% +chemical Transformations that you'll be + + + align:start position:0% +chemical Transformations that you'll be +looking at over the course of the + + align:start position:0% +looking at over the course of the + + + align:start position:0% +looking at over the course of the +semester \ No newline at end of file diff --git a/VYS9EYZ3gCo.txt b/VYS9EYZ3gCo.txt new file mode 100644 index 0000000000000000000000000000000000000000..47afcf810f4924622e76559cb24870e947c0618e --- /dev/null +++ b/VYS9EYZ3gCo.txt @@ -0,0 +1,1891 @@ +align:start position:0% + +hi everyone welcome back so today we're + + align:start position:0% +hi everyone welcome back so today we're + + + align:start position:0% +hi everyone welcome back so today we're +going to tackle a problem in complex + + align:start position:0% +going to tackle a problem in complex + + + align:start position:0% +going to tackle a problem in complex +matrices and specifically we're going to + + align:start position:0% +matrices and specifically we're going to + + + align:start position:0% +matrices and specifically we're going to +look at diagonalizing a complex matrix + + align:start position:0% +look at diagonalizing a complex matrix + + + align:start position:0% +look at diagonalizing a complex matrix +so given this matrix a we're asked to + + align:start position:0% +so given this matrix a we're asked to + + + align:start position:0% +so given this matrix a we're asked to +find its eigenvalue matrix lambda and + + align:start position:0% +find its eigenvalue matrix lambda and + + + align:start position:0% +find its eigenvalue matrix lambda and +its eigenvector matrix x and one thing + + align:start position:0% +its eigenvector matrix x and one thing + + + align:start position:0% +its eigenvector matrix x and one thing +to note about this matrix a is that if + + align:start position:0% +to note about this matrix a is that if + + + align:start position:0% +to note about this matrix a is that if +we take its conjugate transpose it's + + align:start position:0% +we take its conjugate transpose it's + + + align:start position:0% +we take its conjugate transpose it's +actually equal to itself so in professor + + align:start position:0% +actually equal to itself so in professor + + + align:start position:0% +actually equal to itself so in professor +Strang's + + align:start position:0% +Strang's + + + align:start position:0% +Strang's +book he combines this notation to be a + + align:start position:0% +book he combines this notation to be a + + + align:start position:0% +book he combines this notation to be a +superscript H to mean conjugate + + align:start position:0% +superscript H to mean conjugate + + + align:start position:0% +superscript H to mean conjugate +transpose so if you were to take the + + align:start position:0% +transpose so if you were to take the + + + align:start position:0% +transpose so if you were to take the +transpose of this matrix and then + + align:start position:0% +transpose of this matrix and then + + + align:start position:0% +transpose of this matrix and then +conjugate all the elements you would + + align:start position:0% +conjugate all the elements you would + + + align:start position:0% +conjugate all the elements you would +find that a equals its conjugate + + align:start position:0% +find that a equals its conjugate + + + align:start position:0% +find that a equals its conjugate +transpose and we call this property + + align:start position:0% +transpose and we call this property + + + align:start position:0% +transpose and we call this property +hermitian okay so let you think about + + align:start position:0% +hermitian okay so let you think about + + + align:start position:0% +hermitian okay so let you think about +this for a moment and I'll be back in a + + align:start position:0% +this for a moment and I'll be back in a + + + align:start position:0% +this for a moment and I'll be back in a +sec + + align:start position:0% + + + + align:start position:0% + +okay welcome back so what's the first + + align:start position:0% +okay welcome back so what's the first + + + align:start position:0% +okay welcome back so what's the first +step in computing the eigenvectors and + + align:start position:0% +step in computing the eigenvectors and + + + align:start position:0% +step in computing the eigenvectors and +eigenvalues of a matrix it's to take a + + align:start position:0% +eigenvalues of a matrix it's to take a + + + align:start position:0% +eigenvalues of a matrix it's to take a +look at the characteristic equation so + + align:start position:0% +look at the characteristic equation so + + + align:start position:0% +look at the characteristic equation so +specifically we take DET of a minus + + align:start position:0% +specifically we take DET of a minus + + + align:start position:0% +specifically we take DET of a minus +lambda i and quite possibly the only + + align:start position:0% +lambda i and quite possibly the only + + + align:start position:0% +lambda i and quite possibly the only +thing new with this problem is that the + + align:start position:0% +thing new with this problem is that the + + + align:start position:0% +thing new with this problem is that the +entries of the matrix a are complex now + + align:start position:0% +entries of the matrix a are complex now + + + align:start position:0% +entries of the matrix a are complex now +you may have already seen that lambdas + + align:start position:0% +you may have already seen that lambdas + + + align:start position:0% +you may have already seen that lambdas +being complex but we're going to work + + align:start position:0% +being complex but we're going to work + + + align:start position:0% +being complex but we're going to work +this out explicitly so if I take the + + align:start position:0% +this out explicitly so if I take the + + + align:start position:0% +this out explicitly so if I take the +determinant we get DET of 2 minus lambda + + align:start position:0% +determinant we get DET of 2 minus lambda + + + align:start position:0% +determinant we get DET of 2 minus lambda +3 minus lambda we have 1 minus I 1 plus + + align:start position:0% +3 minus lambda we have 1 minus I 1 plus + + + align:start position:0% +3 minus lambda we have 1 minus I 1 plus +I we want to set this to 0 this then + + align:start position:0% +I we want to set this to 0 this then + + + align:start position:0% +I we want to set this to 0 this then +gives us a polynomial for lambda 1 plus + + align:start position:0% +gives us a polynomial for lambda 1 plus + + + align:start position:0% +gives us a polynomial for lambda 1 plus +I 1 minus I we set it equal to 0 we can + + align:start position:0% +I 1 minus I we set it equal to 0 we can + + + align:start position:0% +I 1 minus I we set it equal to 0 we can +expand out this term we get 6 minus 5 + + align:start position:0% +expand out this term we get 6 minus 5 + + + align:start position:0% +expand out this term we get 6 minus 5 +lambda plus lambda squared these 2 terms + + align:start position:0% +lambda plus lambda squared these 2 terms + + + align:start position:0% +lambda plus lambda squared these 2 terms +you'll note are complex conjugates of + + align:start position:0% +you'll note are complex conjugates of + + + align:start position:0% +you'll note are complex conjugates of +each other + + align:start position:0% +each other + + + align:start position:0% +each other +this tends to make things simple so we + + align:start position:0% +this tends to make things simple so we + + + align:start position:0% +this tends to make things simple so we +have minus 1 minus I squared is going to + + align:start position:0% +have minus 1 minus I squared is going to + + + align:start position:0% +have minus 1 minus I squared is going to +give us 2 because there are differences + + align:start position:0% +give us 2 because there are differences + + + align:start position:0% +give us 2 because there are differences +of squares the cross terms involving I + + align:start position:0% +of squares the cross terms involving I + + + align:start position:0% +of squares the cross terms involving I +cancel and we get the characteristic + + align:start position:0% +cancel and we get the characteristic + + + align:start position:0% +cancel and we get the characteristic +equation + + align:start position:0% + + + + align:start position:0% + +lambda squared minus 5 lambda plus 4 + + align:start position:0% +lambda squared minus 5 lambda plus 4 + + + align:start position:0% +lambda squared minus 5 lambda plus 4 +equals 0 and specifically we can + + align:start position:0% +equals 0 and specifically we can + + + align:start position:0% +equals 0 and specifically we can +factorize this equation we see that + + align:start position:0% +factorize this equation we see that + + + align:start position:0% +factorize this equation we see that +there's roots of minus 1 there + + align:start position:0% +there's roots of minus 1 there + + + align:start position:0% +there's roots of minus 1 there +factorizes into factors of lambda minus + + align:start position:0% +factorizes into factors of lambda minus + + + align:start position:0% +factorizes into factors of lambda minus +1 and lambda minus 4 which then give us + + align:start position:0% +1 and lambda minus 4 which then give us + + + align:start position:0% +1 and lambda minus 4 which then give us +roots of lambda is 1 and lambda is 4 so + + align:start position:0% +roots of lambda is 1 and lambda is 4 so + + + align:start position:0% +roots of lambda is 1 and lambda is 4 so +when one curious point to note is that + + align:start position:0% +when one curious point to note is that + + + align:start position:0% +when one curious point to note is that +the eigenvalues are real in this case 1 + + align:start position:0% +the eigenvalues are real in this case 1 + + + align:start position:0% +the eigenvalues are real in this case 1 +and 4 are real whereas the matrix that + + align:start position:0% +and 4 are real whereas the matrix that + + + align:start position:0% +and 4 are real whereas the matrix that +we started with was complex and this is + + align:start position:0% +we started with was complex and this is + + + align:start position:0% +we started with was complex and this is +a general property of hermitian matrices + + align:start position:0% +a general property of hermitian matrices + + + align:start position:0% +a general property of hermitian matrices +so even though they might be complex + + align:start position:0% +so even though they might be complex + + + align:start position:0% +so even though they might be complex +matrices hermitian matrices always have + + align:start position:0% +matrices hermitian matrices always have + + + align:start position:0% +matrices hermitian matrices always have +real eigenvalues ok so this is the first + + align:start position:0% +real eigenvalues ok so this is the first + + + align:start position:0% +real eigenvalues ok so this is the first +step when I ask to diagonalize a matrix + + align:start position:0% +step when I ask to diagonalize a matrix + + + align:start position:0% +step when I ask to diagonalize a matrix +the second step is to find the + + align:start position:0% +the second step is to find the + + + align:start position:0% +the second step is to find the +eigenvectors and to do that what we have + + align:start position:0% +eigenvectors and to do that what we have + + + align:start position:0% +eigenvectors and to do that what we have +to do is we have to look at the cases + + align:start position:0% +to do is we have to look at the cases + + + align:start position:0% +to do is we have to look at the cases +for lambda equals 1 and lambda is equal + + align:start position:0% +for lambda equals 1 and lambda is equal + + + align:start position:0% +for lambda equals 1 and lambda is equal +4 separately so let's first look at the + + align:start position:0% +4 separately so let's first look at the + + + align:start position:0% +4 separately so let's first look at the +case of lambda is equal to 1 and + + align:start position:0% +case of lambda is equal to 1 and + + + align:start position:0% +case of lambda is equal to 1 and +specifically we're going to be looking + + align:start position:0% +specifically we're going to be looking + + + align:start position:0% +specifically we're going to be looking +for a vector such that a minus lambda I + + align:start position:0% +for a vector such that a minus lambda I + + + align:start position:0% +for a vector such that a minus lambda I +times the vector V is 0 and if we've + + align:start position:0% +times the vector V is 0 and if we've + + + align:start position:0% +times the vector V is 0 and if we've +done things properly this matrix lambda + + align:start position:0% +done things properly this matrix lambda + + + align:start position:0% +done things properly this matrix lambda +minus or sorry a minus lambda I should + + align:start position:0% +minus or sorry a minus lambda I should + + + align:start position:0% +minus or sorry a minus lambda I should +be singular so if we take a minus lambda + + align:start position:0% +be singular so if we take a minus lambda + + + align:start position:0% +be singular so if we take a minus lambda +I we're going to get 1 1 minus I 1 plus + + align:start position:0% +I we're going to get 1 1 minus I 1 plus + + + align:start position:0% +I we're going to get 1 1 minus I 1 plus +I 3 minus 1 is 2 and I'll write out + + align:start position:0% +I 3 minus 1 is 2 and I'll write out + + + align:start position:0% +I 3 minus 1 is 2 and I'll write out +components of V which are V 1 and V 2 + + align:start position:0% +components of V which are V 1 and V 2 + + + align:start position:0% +components of V which are V 1 and V 2 +and we want this to be 0 and you'll note + + align:start position:0% +and we want this to be 0 and you'll note + + + align:start position:0% +and we want this to be 0 and you'll note +that it's it's always the case it's + + align:start position:0% +that it's it's always the case it's + + + align:start position:0% +that it's it's always the case it's +almost always the case that when we work + + align:start position:0% +almost always the case that when we work + + + align:start position:0% +almost always the case that when we work +out a minus lambda I the second row is + + align:start position:0% +out a minus lambda I the second row is + + + align:start position:0% +out a minus lambda I the second row is +going to be a constant multiple of the + + align:start position:0% +going to be a constant multiple of the + + + align:start position:0% +going to be a constant multiple of the +first row and this must be the case + + align:start position:0% +first row and this must be the case + + + align:start position:0% +first row and this must be the case +because these two rows must be linearly + + align:start position:0% +because these two rows must be linearly + + + align:start position:0% +because these two rows must be linearly +depend + + align:start position:0% +depend + + + align:start position:0% +depend +on each other for the matrix a minus + + align:start position:0% +on each other for the matrix a minus + + + align:start position:0% +on each other for the matrix a minus +lambda I to be singular so if you look + + align:start position:0% +lambda I to be singular so if you look + + + align:start position:0% +lambda I to be singular so if you look +at this you might think that these two + + align:start position:0% +at this you might think that these two + + + align:start position:0% +at this you might think that these two +rows aren't necessarily linearly + + align:start position:0% +rows aren't necessarily linearly + + + align:start position:0% +rows aren't necessarily linearly +independent but the point is that + + align:start position:0% +independent but the point is that + + + align:start position:0% +independent but the point is that +there's complex numbers involved and + + align:start position:0% +there's complex numbers involved and + + + align:start position:0% +there's complex numbers involved and +indeed actually if we were to multiply + + align:start position:0% +indeed actually if we were to multiply + + + align:start position:0% +indeed actually if we were to multiply +this first row by 1 plus lambda we would + + align:start position:0% +this first row by 1 plus lambda we would + + + align:start position:0% +this first row by 1 plus lambda we would +get 1 plus lambda and 2 and you note + + align:start position:0% +get 1 plus lambda and 2 and you note + + + align:start position:0% +get 1 plus lambda and 2 and you note +that that's exactly the second row so + + align:start position:0% +that that's exactly the second row so + + + align:start position:0% +that that's exactly the second row so +this second row is actually 1 plus + + align:start position:0% +this second row is actually 1 plus + + + align:start position:0% +this second row is actually 1 plus +lambda times the first row so these rows + + align:start position:0% +lambda times the first row so these rows + + + align:start position:0% +lambda times the first row so these rows +are actually linearly dependent on each + + align:start position:0% +are actually linearly dependent on each + + + align:start position:0% +are actually linearly dependent on each +other okay so what values of V 1 and V 2 + + align:start position:0% +other okay so what values of V 1 and V 2 + + + align:start position:0% +other okay so what values of V 1 and V 2 +can we take well we just need to make + + align:start position:0% +can we take well we just need to make + + + align:start position:0% +can we take well we just need to make +this top row multiplied by V 1 and V 2 + + align:start position:0% +this top row multiplied by V 1 and V 2 + + + align:start position:0% +this top row multiplied by V 1 and V 2 +equal to 0 and then because the second + + align:start position:0% +equal to 0 and then because the second + + + align:start position:0% +equal to 0 and then because the second +row is a constant multiple of the first + + align:start position:0% +row is a constant multiple of the first + + + align:start position:0% +row is a constant multiple of the first +row were automatically guaranteed that + + align:start position:0% +row were automatically guaranteed that + + + align:start position:0% +row were automatically guaranteed that +the second equation holds so just by + + align:start position:0% +the second equation holds so just by + + + align:start position:0% +the second equation holds so just by +looking at it I'm going to take V 1 is + + align:start position:0% +looking at it I'm going to take V 1 is + + + align:start position:0% +looking at it I'm going to take V 1 is +equal to 1 minus I and V 2 is negative 1 + + align:start position:0% +equal to 1 minus I and V 2 is negative 1 + + + align:start position:0% +equal to 1 minus I and V 2 is negative 1 +so we see that 1 times 1 minus I minus 1 + + align:start position:0% +so we see that 1 times 1 minus I minus 1 + + + align:start position:0% +so we see that 1 times 1 minus I minus 1 +times 1 minus I is going to give us 0 so + + align:start position:0% +times 1 minus I is going to give us 0 so + + + align:start position:0% +times 1 minus I is going to give us 0 so +this is one solution and of course we + + align:start position:0% +this is one solution and of course we + + + align:start position:0% +this is one solution and of course we +can take any constant multiple times + + align:start position:0% +can take any constant multiple times + + + align:start position:0% +can take any constant multiple times +this eigenvector and that's also going + + align:start position:0% +this eigenvector and that's also going + + + align:start position:0% +this eigenvector and that's also going +to be an eigenvector so I'll just write + + align:start position:0% +to be an eigenvector so I'll just write + + + align:start position:0% +to be an eigenvector so I'll just write +this out 1 minus I minus 1 is the + + align:start position:0% +this out 1 minus I minus 1 is the + + + align:start position:0% +this out 1 minus I minus 1 is the +eigenvector for lambda is equal to 1 for + + align:start position:0% +eigenvector for lambda is equal to 1 for + + + align:start position:0% +eigenvector for lambda is equal to 1 for +lambda is equal to 4 again a minus + + align:start position:0% +lambda is equal to 4 again a minus + + + align:start position:0% +lambda is equal to 4 again a minus +lambda I is going to give us negative 2 + + align:start position:0% +lambda I is going to give us negative 2 + + + align:start position:0% +lambda I is going to give us negative 2 +1 minus I 1 plus I 3 minus lambda is + + align:start position:0% +1 minus I 1 plus I 3 minus lambda is + + + align:start position:0% +1 minus I 1 plus I 3 minus lambda is +going to be minus 1 and I'll call this + + align:start position:0% +going to be minus 1 and I'll call this + + + align:start position:0% +going to be minus 1 and I'll call this +vector u 1 and u 2 and again we want u 1 + + align:start position:0% +vector u 1 and u 2 and again we want u 1 + + + align:start position:0% +vector u 1 and u 2 and again we want u 1 +u 2 equal to 0 or sorry the matrix + + align:start position:0% +u 2 equal to 0 or sorry the matrix + + + align:start position:0% +u 2 equal to 0 or sorry the matrix +multiplied by u 1 u 2 is equal to 0 and + + align:start position:0% +multiplied by u 1 u 2 is equal to 0 and + + + align:start position:0% +multiplied by u 1 u 2 is equal to 0 and +just by looking at this again we see + + align:start position:0% +just by looking at this again we see + + + align:start position:0% +just by looking at this again we see +that the second row is actually a + + align:start position:0% +that the second row is actually a + + + align:start position:0% +that the second row is actually a +constant multiple of the first row for + + align:start position:0% +constant multiple of the first row for + + + align:start position:0% +constant multiple of the first row for +example if we were to multiply this this + + align:start position:0% +example if we were to multiply this this + + + align:start position:0% +example if we were to multiply this this +row by negative 2 and this row by 1 plus + + align:start position:0% +row by negative 2 and this row by 1 plus + + + align:start position:0% +row by negative 2 and this row by 1 plus +I we would see that there constant + + align:start position:0% +I we would see that there constant + + + align:start position:0% +I we would see that there constant +multiples of each + + align:start position:0% +multiples of each + + + align:start position:0% +multiples of each +so I can take you to B for example 1 + 1 + + align:start position:0% +so I can take you to B for example 1 + 1 + + + align:start position:0% +so I can take you to B for example 1 + 1 ++ I how did I get this well I just + + align:start position:0% ++ I how did I get this well I just + + + align:start position:0% ++ I how did I get this well I just +looked at the second equation because + + align:start position:0% +looked at the second equation because + + + align:start position:0% +looked at the second equation because +it's a little simpler and I said well if + + align:start position:0% +it's a little simpler and I said well if + + + align:start position:0% +it's a little simpler and I said well if +I have 1 plus I here + + align:start position:0% +I have 1 plus I here + + + align:start position:0% +I have 1 plus I here +I can just say multiply by 1 and then + + align:start position:0% +I can just say multiply by 1 and then + + + align:start position:0% +I can just say multiply by 1 and then +minus 1 times 1 plus I when I add them + + align:start position:0% +minus 1 times 1 plus I when I add them + + + align:start position:0% +minus 1 times 1 plus I when I add them +up is going to vanish so this is how I + + align:start position:0% +up is going to vanish so this is how I + + + align:start position:0% +up is going to vanish so this is how I +get the second one now there's something + + align:start position:0% +get the second one now there's something + + + align:start position:0% +get the second one now there's something +curious going on and this is going to be + + align:start position:0% +curious going on and this is going to be + + + align:start position:0% +curious going on and this is going to be +another property of hermitian matrices + + align:start position:0% +another property of hermitian matrices + + + align:start position:0% +another property of hermitian matrices +but if you actually take a look at this + + align:start position:0% +but if you actually take a look at this + + + align:start position:0% +but if you actually take a look at this +eigenvector it will be orthogonal to + + align:start position:0% +eigenvector it will be orthogonal to + + + align:start position:0% +eigenvector it will be orthogonal to +this eigenvector when we conjugate the + + align:start position:0% +this eigenvector when we conjugate the + + + align:start position:0% +this eigenvector when we conjugate the +elements and dot the two vectors + + align:start position:0% +elements and dot the two vectors + + + align:start position:0% +elements and dot the two vectors +together + + align:start position:0% +together + + + align:start position:0% +together +so this is another very special property + + align:start position:0% +so this is another very special property + + + align:start position:0% +so this is another very special property +of complex hermitian matrices ok so the + + align:start position:0% +of complex hermitian matrices ok so the + + + align:start position:0% +of complex hermitian matrices ok so the +last step now is to construct these + + align:start position:0% +last step now is to construct these + + + align:start position:0% +last step now is to construct these +matrices lambda n s now we already know + + align:start position:0% +matrices lambda n s now we already know + + + align:start position:0% +matrices lambda n s now we already know +what lambda is because it's just the + + align:start position:0% +what lambda is because it's just the + + + align:start position:0% +what lambda is because it's just the +matrix it's the diagonal matrix with the + + align:start position:0% +matrix it's the diagonal matrix with the + + + align:start position:0% +matrix it's the diagonal matrix with the +eigenvalues 1 in 4 so we have 1 0 0 and + + align:start position:0% +eigenvalues 1 in 4 so we have 1 0 0 and + + + align:start position:0% +eigenvalues 1 in 4 so we have 1 0 0 and +for now I'm going to do something + + align:start position:0% +for now I'm going to do something + + + align:start position:0% +for now I'm going to do something +special for s I've noticed I've noted + + align:start position:0% +special for s I've noticed I've noted + + + align:start position:0% +special for s I've noticed I've noted +that these two vectors U and V are + + align:start position:0% +that these two vectors U and V are + + + align:start position:0% +that these two vectors U and V are +orthogonal to each other so what do I + + align:start position:0% +orthogonal to each other so what do I + + + align:start position:0% +orthogonal to each other so what do I +mean by orthogonal specifically if I + + align:start position:0% +mean by orthogonal specifically if I + + + align:start position:0% +mean by orthogonal specifically if I +were to take V conjugate transpose and + + align:start position:0% +were to take V conjugate transpose and + + + align:start position:0% +were to take V conjugate transpose and +multiply it by u we would end up getting + + align:start position:0% +multiply it by u we would end up getting + + + align:start position:0% +multiply it by u we would end up getting +1 plus I minus 1 this would be the + + align:start position:0% +1 plus I minus 1 this would be the + + + align:start position:0% +1 plus I minus 1 this would be the +conjugate transpose 1 1 plus I and we + + align:start position:0% +conjugate transpose 1 1 plus I and we + + + align:start position:0% +conjugate transpose 1 1 plus I and we +see that when we multiply these out we + + align:start position:0% +see that when we multiply these out we + + + align:start position:0% +see that when we multiply these out we +get 0 so when we have orthogonal eigen + + align:start position:0% +get 0 so when we have orthogonal eigen + + + align:start position:0% +get 0 so when we have orthogonal eigen +vectors there's a trick that we can do + + align:start position:0% +vectors there's a trick that we can do + + + align:start position:0% +vectors there's a trick that we can do +to build up this matrix s and s inverse + + align:start position:0% +to build up this matrix s and s inverse + + + align:start position:0% +to build up this matrix s and s inverse +what we can do is we can normalize U and + + align:start position:0% +what we can do is we can normalize U and + + + align:start position:0% +what we can do is we can normalize U and +V so specifically we can take any + + align:start position:0% +V so specifically we can take any + + + align:start position:0% +V so specifically we can take any +constant multiple of U and V and it's + + align:start position:0% +constant multiple of U and V and it's + + + align:start position:0% +constant multiple of U and V and it's +still going to be an eigen vector so + + align:start position:0% +still going to be an eigen vector so + + + align:start position:0% +still going to be an eigen vector so +what I'm going to do is I'm going to + + align:start position:0% +what I'm going to do is I'm going to + + + align:start position:0% +what I'm going to do is I'm going to +take U and V and multiply them by their + + align:start position:0% +take U and V and multiply them by their + + + align:start position:0% +take U and V and multiply them by their +length so for example you + + align:start position:0% +length so for example you + + + align:start position:0% +length so for example you +the amplitude of its top component is 1 + + align:start position:0% +the amplitude of its top component is 1 + + + align:start position:0% +the amplitude of its top component is 1 +the amplitude of its bottom component is + + align:start position:0% +the amplitude of its bottom component is + + + align:start position:0% +the amplitude of its bottom component is +2 so notice that the modulus of the + + align:start position:0% +2 so notice that the modulus of the + + + align:start position:0% +2 so notice that the modulus of the +complex number 1 + I is 2 so we have + + align:start position:0% + + + + align:start position:0% + +sorry it's it's root to the complex + + align:start position:0% +sorry it's it's root to the complex + + + align:start position:0% +sorry it's it's root to the complex +modulus is root 2 so the amplitude of + + align:start position:0% +modulus is root 2 so the amplitude of + + + align:start position:0% +modulus is root 2 so the amplitude of +the entire vector is root 3 it's 1 plus + + align:start position:0% +the entire vector is root 3 it's 1 plus + + + align:start position:0% +the entire vector is root 3 it's 1 plus +2 squared quantity square rooting so + + align:start position:0% +2 squared quantity square rooting so + + + align:start position:0% +2 squared quantity square rooting so +it's root 3 so what we can do is we can + + align:start position:0% +it's root 3 so what we can do is we can + + + align:start position:0% +it's root 3 so what we can do is we can +build up this matrix s using a + + align:start position:0% +build up this matrix s using a + + + align:start position:0% +build up this matrix s using a +normalization factor of 1 over root 3 + + align:start position:0% + + + + align:start position:0% + +and I'm going to take the the first + + align:start position:0% +and I'm going to take the the first + + + align:start position:0% +and I'm going to take the the first +column is the first eigenvector that + + align:start position:0% +column is the first eigenvector that + + + align:start position:0% +column is the first eigenvector that +corresponds to eigenvalue 1 and then the + + align:start position:0% +corresponds to eigenvalue 1 and then the + + + align:start position:0% +corresponds to eigenvalue 1 and then the +second column is the second eigen vector + + align:start position:0% +second column is the second eigen vector + + + align:start position:0% +second column is the second eigen vector +which corresponds to eigenvalue 4 and + + align:start position:0% +which corresponds to eigenvalue 4 and + + + align:start position:0% +which corresponds to eigenvalue 4 and +the reason I've put in this root 3 here + + align:start position:0% +the reason I've put in this root 3 here + + + align:start position:0% +the reason I've put in this root 3 here +is to make this column unit length 1 and + + align:start position:0% +is to make this column unit length 1 and + + + align:start position:0% +is to make this column unit length 1 and +this column unit length 1 and the reason + + align:start position:0% +this column unit length 1 and the reason + + + align:start position:0% +this column unit length 1 and the reason +I do this is because now this matrix S + + align:start position:0% +I do this is because now this matrix S + + + align:start position:0% +I do this is because now this matrix S +it's it's it's possible to check that + + align:start position:0% +it's it's it's possible to check that + + + align:start position:0% +it's it's it's possible to check that +this matrix S is actually unitary which + + align:start position:0% +this matrix S is actually unitary which + + + align:start position:0% +this matrix S is actually unitary which +means that its inverse is actually just + + align:start position:0% +means that its inverse is actually just + + + align:start position:0% +means that its inverse is actually just +equal to its conjugate transpose so this + + align:start position:0% +equal to its conjugate transpose so this + + + align:start position:0% +equal to its conjugate transpose so this +is a very special property of the of the + + align:start position:0% +is a very special property of the of the + + + align:start position:0% +is a very special property of the of the +eigenvectors of a hermitian matrix ok + + align:start position:0% +eigenvectors of a hermitian matrix ok + + + align:start position:0% +eigenvectors of a hermitian matrix ok +and then lastly I'm just going to write + + align:start position:0% +and then lastly I'm just going to write + + + align:start position:0% +and then lastly I'm just going to write +down the diagonalization of a so if I + + align:start position:0% +down the diagonalization of a so if I + + + align:start position:0% +down the diagonalization of a so if I +have a because I have its eigenvector + + align:start position:0% +have a because I have its eigenvector + + + align:start position:0% +have a because I have its eigenvector +matrix s and its eigenvalue matrix + + align:start position:0% +matrix s and its eigenvalue matrix + + + align:start position:0% +matrix s and its eigenvalue matrix +lambda it's possible to decompose a into + + align:start position:0% +lambda it's possible to decompose a into + + + align:start position:0% +lambda it's possible to decompose a into +a product of s lambda s inverse and + + align:start position:0% +a product of s lambda s inverse and + + + align:start position:0% +a product of s lambda s inverse and +because s is for me or s is unitary its + + align:start position:0% +because s is for me or s is unitary its + + + align:start position:0% +because s is for me or s is unitary its +inverse is actually its conjugate + + align:start position:0% +inverse is actually its conjugate + + + align:start position:0% +inverse is actually its conjugate +transpose so just to put the pieces + + align:start position:0% +transpose so just to put the pieces + + + align:start position:0% +transpose so just to put the pieces +together we + + align:start position:0% +together we + + + align:start position:0% +together we +a is equal to s which is 1 over root 3 1 + + align:start position:0% +a is equal to s which is 1 over root 3 1 + + + align:start position:0% +a is equal to s which is 1 over root 3 1 +minus I minus 1 1 1 plus I times the + + align:start position:0% +minus I minus 1 1 1 plus I times the + + + align:start position:0% +minus I minus 1 1 1 plus I times the +diagonal matrix 1 0 0 4 times s inverse + + align:start position:0% +diagonal matrix 1 0 0 4 times s inverse + + + align:start position:0% +diagonal matrix 1 0 0 4 times s inverse +which is going to be its conjugate + + align:start position:0% +which is going to be its conjugate + + + align:start position:0% +which is going to be its conjugate +transpose so what I do is I conjugate + + align:start position:0% +transpose so what I do is I conjugate + + + align:start position:0% +transpose so what I do is I conjugate +each element so 1 minus I becomes 1 plus + + align:start position:0% +each element so 1 minus I becomes 1 plus + + + align:start position:0% +each element so 1 minus I becomes 1 plus +I and vice versa and then I take the + + align:start position:0% +I and vice versa and then I take the + + + align:start position:0% +I and vice versa and then I take the +transpose so I get 1 plus I transposing + + align:start position:0% +transpose so I get 1 plus I transposing + + + align:start position:0% +transpose so I get 1 plus I transposing +swaps the minus 1 and 1 and at the end + + align:start position:0% +swaps the minus 1 and 1 and at the end + + + align:start position:0% +swaps the minus 1 and 1 and at the end +of the day I get s inverse is just this + + align:start position:0% +of the day I get s inverse is just this + + + align:start position:0% +of the day I get s inverse is just this +matrix here ok + + align:start position:0% +matrix here ok + + + align:start position:0% +matrix here ok +and if you were to multiply these + + align:start position:0% +and if you were to multiply these + + + align:start position:0% +and if you were to multiply these +matrices out you would see that you + + align:start position:0% +matrices out you would see that you + + + align:start position:0% +matrices out you would see that you +actually do recover a ok so just to + + align:start position:0% +actually do recover a ok so just to + + + align:start position:0% +actually do recover a ok so just to +summarize quickly even though we were + + align:start position:0% +summarize quickly even though we were + + + align:start position:0% +summarize quickly even though we were +given a complex matrix a the the process + + align:start position:0% +given a complex matrix a the the process + + + align:start position:0% +given a complex matrix a the the process +to diagonalize a was this is the same as + + align:start position:0% +to diagonalize a was this is the same as + + + align:start position:0% +to diagonalize a was this is the same as +what we've seen before the first step is + + align:start position:0% +what we've seen before the first step is + + + align:start position:0% +what we've seen before the first step is +to find the characteristic equation and + + align:start position:0% +to find the characteristic equation and + + + align:start position:0% +to find the characteristic equation and +the eigenvalues and then the second step + + align:start position:0% +the eigenvalues and then the second step + + + align:start position:0% +the eigenvalues and then the second step +is to find the eigenvectors and you do + + align:start position:0% +is to find the eigenvectors and you do + + + align:start position:0% +is to find the eigenvectors and you do +this in the same procedure but in + + align:start position:0% +this in the same procedure but in + + + align:start position:0% +this in the same procedure but in +general the eigenvectors can be complex + + align:start position:0% +general the eigenvectors can be complex + + + align:start position:0% +general the eigenvectors can be complex +and for this very special case when a is + + align:start position:0% +and for this very special case when a is + + + align:start position:0% +and for this very special case when a is +hermitian the eigenvalues are real and + + align:start position:0% +hermitian the eigenvalues are real and + + + align:start position:0% +hermitian the eigenvalues are real and +the eigenvectors are orthogonal to each + + align:start position:0% +the eigenvectors are orthogonal to each + + + align:start position:0% +the eigenvectors are orthogonal to each +other ok so I think I'll conclude here + + align:start position:0% +other ok so I think I'll conclude here + + + align:start position:0% +other ok so I think I'll conclude here +and I'll see you next time \ No newline at end of file diff --git a/VqXKa11IA6A.txt b/VqXKa11IA6A.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d7578995387d15aecb5e2ee049902b2d6271340 --- /dev/null +++ b/VqXKa11IA6A.txt @@ -0,0 +1,2531 @@ +align:start position:0% + +okay uh this is the second video for + + align:start position:0% +okay uh this is the second video for + + + align:start position:0% +okay uh this is the second video for +chapter three and it's going to be + + align:start position:0% +chapter three and it's going to be + + + align:start position:0% +chapter three and it's going to be +pictures again but it's pictures for a + + align:start position:0% +pictures again but it's pictures for a + + + align:start position:0% +pictures again but it's pictures for a +second order + + align:start position:0% +second order + + + align:start position:0% +second order +equation uh and in and I'll make them + + align:start position:0% +equation uh and in and I'll make them + + + align:start position:0% +equation uh and in and I'll make them +these will be nice we'll know formulas + + align:start position:0% +these will be nice we'll know formulas + + + align:start position:0% +these will be nice we'll know formulas +here these will be constant coefficient + + align:start position:0% +here these will be constant coefficient + + + align:start position:0% +here these will be constant coefficient +linear second order equations and we + + align:start position:0% +linear second order equations and we + + + align:start position:0% +linear second order equations and we +know that the solution there are + + align:start position:0% +know that the solution there are + + + align:start position:0% +know that the solution there are +two uh special Solutions e to the s 1 T + + align:start position:0% +two uh special Solutions e to the s 1 T + + + align:start position:0% +two uh special Solutions e to the s 1 T +and e to the s2t two null Solutions and + + align:start position:0% +and e to the s2t two null Solutions and + + + align:start position:0% +and e to the s2t two null Solutions and +any combination is a null solution so + + align:start position:0% +any combination is a null solution so + + + align:start position:0% +any combination is a null solution so +we're talking about null equations zero + + align:start position:0% +we're talking about null equations zero + + + align:start position:0% +we're talking about null equations zero +on the right hand side and we just want + + align:start position:0% +on the right hand side and we just want + + + align:start position:0% +on the right hand side and we just want +to draw that picture that goes with + + align:start position:0% +to draw that picture that goes with + + + align:start position:0% +to draw that picture that goes with +Solutions like that so the here is the + + align:start position:0% +Solutions like that so the here is the + + + align:start position:0% +Solutions like that so the here is the +magic word phase + + align:start position:0% +magic word phase + + + align:start position:0% +magic word phase +plane phase plane we're going to draw + + align:start position:0% +plane phase plane we're going to draw + + + align:start position:0% +plane phase plane we're going to draw +the pictures in a plane because that's + + align:start position:0% +the pictures in a plane because that's + + + align:start position:0% +the pictures in a plane because that's +what I'm Blackboard is and the axes we + + align:start position:0% +what I'm Blackboard is and the axes we + + + align:start position:0% +what I'm Blackboard is and the axes we +choose will be Y and Y Prime not + + align:start position:0% +choose will be Y and Y Prime not + + + align:start position:0% +choose will be Y and Y Prime not +t you'll see how T time comes into the + + align:start position:0% +t you'll see how T time comes into the + + + align:start position:0% +t you'll see how T time comes into the +picture but we have the two axes will be + + align:start position:0% +picture but we have the two axes will be + + + align:start position:0% +picture but we have the two axes will be +Y and Y Prime so I had to figure out + + align:start position:0% +Y and Y Prime so I had to figure out + + + align:start position:0% +Y and Y Prime so I had to figure out +what y Prime was it just brings down an + + align:start position:0% +what y Prime was it just brings down an + + + align:start position:0% +what y Prime was it just brings down an +S1 from that term and brings down an S2 + + align:start position:0% +S1 from that term and brings down an S2 + + + align:start position:0% +S1 from that term and brings down an S2 +from that term and now here's the + + align:start position:0% +from that term and now here's the + + + align:start position:0% +from that term and now here's the +example here's the first + + align:start position:0% +example here's the first + + + align:start position:0% +example here's the first +example uh so I made this took this + + align:start position:0% +example uh so I made this took this + + + align:start position:0% +example uh so I made this took this +particular equation notice that the uh + + align:start position:0% +particular equation notice that the uh + + + align:start position:0% +particular equation notice that the uh +damping term is negative I have negative + + align:start position:0% +damping term is negative I have negative + + + align:start position:0% +damping term is negative I have negative +damping this will be unstable Solutions + + align:start position:0% +damping this will be unstable Solutions + + + align:start position:0% +damping this will be unstable Solutions +will go out to infinity and I can find + + align:start position:0% +will go out to infinity and I can find + + + align:start position:0% +will go out to infinity and I can find +those Solutions because you know that I + + align:start position:0% +those Solutions because you know that I + + + align:start position:0% +those Solutions because you know that I +look for e to the St I always look for e + + align:start position:0% +look for e to the St I always look for e + + + align:start position:0% +look for e to the St I always look for e +to the St I plug in e to the St I get an + + align:start position:0% +to the St I plug in e to the St I get an + + + align:start position:0% +to the St I plug in e to the St I get an +s squar from two derivatives - 3S from + + align:start position:0% +s squar from two derivatives - 3S from + + + align:start position:0% +s squar from two derivatives - 3S from +one derivative + 2 equaling 0 I factor + + align:start position:0% +one derivative + 2 equaling 0 I factor + + + align:start position:0% +one derivative + 2 equaling 0 I factor +that and I find the two S1 is one and S2 + + align:start position:0% +that and I find the two S1 is one and S2 + + + align:start position:0% +that and I find the two S1 is one and S2 +is two and now I'm ready for the phase + + align:start position:0% +is two and now I'm ready for the phase + + + align:start position:0% +is two and now I'm ready for the phase +plane picture Okay phase plane + + align:start position:0% +plane picture Okay phase plane + + + align:start position:0% +plane picture Okay phase plane +picture so here are my Solutions s is + + align:start position:0% +picture so here are my Solutions s is + + + align:start position:0% +picture so here are my Solutions s is +one or two then the derivative has a one + + align:start position:0% +one or two then the derivative has a one + + + align:start position:0% +one or two then the derivative has a one +or a two and here's my plane here's my + + align:start position:0% +or a two and here's my plane here's my + + + align:start position:0% +or a two and here's my plane here's my +plane and I want to draw on that the + + align:start position:0% +plane and I want to draw on that the + + + align:start position:0% +plane and I want to draw on that the +solutions these Solutions I actually + + align:start position:0% +solutions these Solutions I actually + + + align:start position:0% +solutions these Solutions I actually +have formulas I just want to draw them + + align:start position:0% +have formulas I just want to draw them + + + align:start position:0% +have formulas I just want to draw them +so I'm plotting the one example would be + + align:start position:0% +so I'm plotting the one example would be + + + align:start position:0% +so I'm plotting the one example would be +let C1 be one and let C2 be zero so + + align:start position:0% +let C1 be one and let C2 be zero so + + + align:start position:0% +let C1 be one and let C2 be zero so +that's gone C1 is one I I just have that + + align:start position:0% +that's gone C1 is one I I just have that + + + align:start position:0% +that's gone C1 is one I I just have that +picture what kind of a picture do I have + + align:start position:0% +picture what kind of a picture do I have + + + align:start position:0% +picture what kind of a picture do I have +in the phase plane in the y y Prime + + align:start position:0% +in the phase plane in the y y Prime + + + align:start position:0% +in the phase plane in the y y Prime +plane when that's Y and that's y Prime + + align:start position:0% +plane when that's Y and that's y Prime + + + align:start position:0% +plane when that's Y and that's y Prime +well those are + + align:start position:0% +well those are + + + align:start position:0% +well those are +equal so y equals y y Prime for that + + align:start position:0% +equal so y equals y y Prime for that + + + align:start position:0% +equal so y equals y y Prime for that +solution y = y Prime along the 45° line + + align:start position:0% +solution y = y Prime along the 45° line + + + align:start position:0% +solution y = y Prime along the 45° line +it's just like yal x y y Prime is y and + + align:start position:0% +it's just like yal x y y Prime is y and + + + align:start position:0% +it's just like yal x y y Prime is y and +what's happening on this 45 Dee line the + + align:start position:0% +what's happening on this 45 Dee line the + + + align:start position:0% +what's happening on this 45 Dee line the +solution is this + + align:start position:0% +solution is this + + + align:start position:0% +solution is this +solution is going straight out the line + + align:start position:0% +solution is going straight out the line + + + align:start position:0% +solution is going straight out the line +as T increases Y and Y Prime both + + align:start position:0% +as T increases Y and Y Prime both + + + align:start position:0% +as T increases Y and Y Prime both +increase I go out to so as T this is T + + align:start position:0% +increase I go out to so as T this is T + + + align:start position:0% +increase I go out to so as T this is T +going to + + align:start position:0% + + + + align:start position:0% + +infinity and what about t going to minus + + align:start position:0% +infinity and what about t going to minus + + + align:start position:0% +infinity and what about t going to minus +infinity cuz we got the whole picture + + align:start position:0% +infinity cuz we got the whole picture + + + align:start position:0% +infinity cuz we got the whole picture +here when T goes to minus infinity that + + align:start position:0% +here when T goes to minus infinity that + + + align:start position:0% +here when T goes to minus infinity that +goes to zero that goes to zero here + + align:start position:0% +goes to zero that goes to zero here + + + align:start position:0% +goes to zero that goes to zero here +here's the point + + align:start position:0% +here's the point + + + align:start position:0% +here's the point +where where the universe began the Big + + align:start position:0% +where where the universe began the Big + + + align:start position:0% +where where the universe began the Big +Bang is right there at t equal minus + + align:start position:0% +Bang is right there at t equal minus + + + align:start position:0% +Bang is right there at t equal minus +infinity and as T + + align:start position:0% +infinity and as T + + + align:start position:0% +infinity and as T +increases this these this point y y + + align:start position:0% +increases this these this point y y + + + align:start position:0% +increases this these this point y y +Prime is is traveling along that 45° + + align:start position:0% +Prime is is traveling along that 45° + + + align:start position:0% +Prime is is traveling along that 45° +line because y equals y Prime and out + + align:start position:0% +line because y equals y Prime and out + + + align:start position:0% +line because y equals y Prime and out +there and what about the rest of the + + align:start position:0% +there and what about the rest of the + + + align:start position:0% +there and what about the rest of the +line well if if I if C1 was negative if + + align:start position:0% +line well if if I if C1 was negative if + + + align:start position:0% +line well if if I if C1 was negative if +C1 was negative I'd have a minus there + + align:start position:0% +C1 was negative I'd have a minus there + + + align:start position:0% +C1 was negative I'd have a minus there +and a minus there I would just have + + align:start position:0% +and a minus there I would just have + + + align:start position:0% +and a minus there I would just have +minuses and I'd be going out that + + align:start position:0% +minuses and I'd be going out that + + + align:start position:0% +minuses and I'd be going out that +line well that's one line in my whole + + align:start position:0% +line well that's one line in my whole + + + align:start position:0% +line well that's one line in my whole +plane but not all now let me take as a + + align:start position:0% +plane but not all now let me take as a + + + align:start position:0% +plane but not all now let me take as a +second line uh C1 equals z so nothing + + align:start position:0% +second line uh C1 equals z so nothing + + + align:start position:0% +second line uh C1 equals z so nothing +from e to the T and let me take y1 as y + + align:start position:0% +from e to the T and let me take y1 as y + + + align:start position:0% +from e to the T and let me take y1 as y +as e to the 2T and Y Prime then would be + + align:start position:0% +as e to the 2T and Y Prime then would be + + + align:start position:0% +as e to the 2T and Y Prime then would be +2 e to + + align:start position:0% +2 e to + + + align:start position:0% +2 e to +2T okay what's happening in the phase + + align:start position:0% +2T okay what's happening in the phase + + + align:start position:0% +2T okay what's happening in the phase +plane for this solution now looking at + + align:start position:0% +plane for this solution now looking at + + + align:start position:0% +plane for this solution now looking at +this one well along in this solution in + + align:start position:0% +this one well along in this solution in + + + align:start position:0% +this one well along in this solution in +this case y Prime is 2 * y y Prime is 2 + + align:start position:0% +this case y Prime is 2 * y y Prime is 2 + + + align:start position:0% +this case y Prime is 2 * y y Prime is 2 +* y so I'm staying on the line Y Prime + + align:start position:0% +* y so I'm staying on the line Y Prime + + + align:start position:0% +* y so I'm staying on the line Y Prime +where y Prime is 2 * y it's a steeper + + align:start position:0% +where y Prime is 2 * y it's a steeper + + + align:start position:0% +where y Prime is 2 * y it's a steeper +line steeper + + align:start position:0% +line steeper + + + align:start position:0% +line steeper +Line This is the case so that was the + + align:start position:0% +Line This is the case so that was the + + + align:start position:0% +Line This is the case so that was the +case this was the line where C2 was Zero + + align:start position:0% +case this was the line where C2 was Zero + + + align:start position:0% +case this was the line where C2 was Zero +there was no e to the 2T on that first + + align:start position:0% +there was no e to the 2T on that first + + + align:start position:0% +there was no e to the 2T on that first +line that we + + align:start position:0% +line that we + + + align:start position:0% +line that we +drew and the second line that we drew + + align:start position:0% +drew and the second line that we drew + + + align:start position:0% +drew and the second line that we drew +C1 is zero there's no e to the T + + align:start position:0% +C1 is zero there's no e to the T + + + align:start position:0% +C1 is zero there's no e to the T +everything is in e to the 2T so now C1 + + align:start position:0% +everything is in e to the 2T so now C1 + + + align:start position:0% +everything is in e to the 2T so now C1 +is zero on this line okay and we just go + + align:start position:0% +is zero on this line okay and we just go + + + align:start position:0% +is zero on this line okay and we just go +out it as T increases y Prime increases + + align:start position:0% +out it as T increases y Prime increases + + + align:start position:0% +out it as T increases y Prime increases +faster because of the factor two so it + + align:start position:0% +faster because of the factor two so it + + + align:start position:0% +faster because of the factor two so it +goes up steeply and it goes this way + + align:start position:0% +goes up steeply and it goes this way + + + align:start position:0% +goes up steeply and it goes this way +when T is negative going to oh no or + + align:start position:0% +when T is negative going to oh no or + + + align:start position:0% +when T is negative going to oh no or +when sorry when C2 is negative if I if + + align:start position:0% +when sorry when C2 is negative if I if + + + align:start position:0% +when sorry when C2 is negative if I if +if I took a minus and a minus I would + + align:start position:0% +if I took a minus and a minus I would + + + align:start position:0% +if I took a minus and a minus I would +just go down uh the other way on the + + align:start position:0% +just go down uh the other way on the + + + align:start position:0% +just go down uh the other way on the +same line and this is still the Big + + align:start position:0% +same line and this is still the Big + + + align:start position:0% +same line and this is still the Big +Bang t equal minus infinity where + + align:start position:0% +Bang t equal minus infinity where + + + align:start position:0% +Bang t equal minus infinity where +everything starts okay so that is two + + align:start position:0% +everything starts okay so that is two + + + align:start position:0% +everything starts okay so that is two +lines two very the two special lines in + + align:start position:0% +lines two very the two special lines in + + + align:start position:0% +lines two very the two special lines in +the phase plane but now I have to draw + + align:start position:0% +the phase plane but now I have to draw + + + align:start position:0% +the phase plane but now I have to draw +all the other curves and they will be + + align:start position:0% +all the other curves and they will be + + + align:start position:0% +all the other curves and they will be +curves and where will they come from + + align:start position:0% +curves and where will they come from + + + align:start position:0% +curves and where will they come from +they will come from a combination + + align:start position:0% +they will come from a combination + + + align:start position:0% +they will come from a combination +now so now I'm ready for that one let me + + align:start position:0% +now so now I'm ready for that one let me + + + align:start position:0% +now so now I'm ready for that one let me +take the case C1 equal 1 C2 equal 1 yeah + + align:start position:0% +take the case C1 equal 1 C2 equal 1 yeah + + + align:start position:0% +take the case C1 equal 1 C2 equal 1 yeah +why not C1 equal 1 so I can erase + + align:start position:0% +why not C1 equal 1 so I can erase + + + align:start position:0% +why not C1 equal 1 so I can erase +C1 C2 equal 1 I can erase + + align:start position:0% +C1 C2 equal 1 I can erase + + + align:start position:0% +C1 C2 equal 1 I can erase +C2 and now I have another solution Y and + + align:start position:0% +C2 and now I have another solution Y and + + + align:start position:0% +C2 and now I have another solution Y and +Y Prime and I want to put it in the + + align:start position:0% +Y Prime and I want to put it in the + + + align:start position:0% +Y Prime and I want to put it in the +phase plane so at every value of t + + align:start position:0% +phase plane so at every value of t + + + align:start position:0% +phase plane so at every value of t +at every value of T that's a point + + align:start position:0% +at every value of T that's a point + + + align:start position:0% +at every value of T that's a point +that's a value of y this is a value of y + + align:start position:0% +that's a value of y this is a value of y + + + align:start position:0% +that's a value of y this is a value of y +Prime I plot the points Y and Y Prime + + align:start position:0% +Prime I plot the points Y and Y Prime + + + align:start position:0% +Prime I plot the points Y and Y Prime +and I look at the picture and again as T + + align:start position:0% +and I look at the picture and again as T + + + align:start position:0% +and I look at the picture and again as T +changes as T changes I'll travel along + + align:start position:0% +changes as T changes I'll travel along + + + align:start position:0% +changes as T changes I'll travel along +the solution curve in the phase plane + + align:start position:0% +the solution curve in the phase plane + + + align:start position:0% +the solution curve in the phase plane +I'll travel along as T changes y will + + align:start position:0% +I'll travel along as T changes y will + + + align:start position:0% +I'll travel along as T changes y will +grow y Prime will grow I'll head out + + align:start position:0% +grow y Prime will grow I'll head out + + + align:start position:0% +grow y Prime will grow I'll head out +here but I won't be on that straight + + align:start position:0% +here but I won't be on that straight + + + align:start position:0% +here but I won't be on that straight +line or that straight line because those + + align:start position:0% +line or that straight line because those + + + align:start position:0% +line or that straight line because those +were the cases when I had only one of + + align:start position:0% +were the cases when I had only one of + + + align:start position:0% +were the cases when I had only one of +the two solutions these were the special + + align:start position:0% +the two solutions these were the special + + + align:start position:0% +the two solutions these were the special +Solutions and now I have a com + + align:start position:0% +Solutions and now I have a com + + + align:start position:0% +Solutions and now I have a com +combination so what happens as T goes to + + align:start position:0% +combination so what happens as T goes to + + + align:start position:0% +combination so what happens as T goes to +Infinity as T goes to Infinity this + + align:start position:0% +Infinity as T goes to Infinity this + + + align:start position:0% +Infinity as T goes to Infinity this +wins as as T goes to + + align:start position:0% +wins as as T goes to + + + align:start position:0% +wins as as T goes to +Infinity the e to the 2T is bigger than + + align:start position:0% +Infinity the e to the 2T is bigger than + + + align:start position:0% +Infinity the e to the 2T is bigger than +e to the T so this is the larger term so + + align:start position:0% +e to the T so this is the larger term so + + + align:start position:0% +e to the T so this is the larger term so +it it approaches this curve now will + + align:start position:0% +it it approaches this curve now will + + + align:start position:0% +it it approaches this curve now will +approach closer and closer to the one + + align:start position:0% +approach closer and closer to the one + + + align:start position:0% +approach closer and closer to the one +when the the the line with slope two the + + align:start position:0% +when the the the line with slope two the + + + align:start position:0% +when the the the line with slope two the +two will be the winner out here but at + + align:start position:0% +two will be the winner out here but at + + + align:start position:0% +two will be the winner out here but at +tal minus infinity near the Big Bang at + + align:start position:0% +tal minus infinity near the Big Bang at + + + align:start position:0% +tal minus infinity near the Big Bang at +tal minus infinity e to the 2T is even + + align:start position:0% +tal minus infinity e to the 2T is even + + + align:start position:0% +tal minus infinity e to the 2T is even +more small so at tal minus infinity + + align:start position:0% +more small so at tal minus infinity + + + align:start position:0% +more small so at tal minus infinity +or tal minus 10 let's say this is eus 10 + + align:start position:0% +or tal minus 10 let's say this is eus 10 + + + align:start position:0% +or tal minus 10 let's say this is eus 10 +this would be eus 20 very very very + + align:start position:0% +this would be eus 20 very very very + + + align:start position:0% +this would be eus 20 very very very +small these would win so what happens + + align:start position:0% +small these would win so what happens + + + align:start position:0% +small these would win so what happens +for this solution is it starts out along + + align:start position:0% +for this solution is it starts out along + + + align:start position:0% +for this solution is it starts out along +the the the line given by the the not so + + align:start position:0% +the the the line given by the the not so + + + align:start position:0% +the the the line given by the the not so +small + + align:start position:0% +small + + + align:start position:0% +small +T the not so small exponent it starts up + + align:start position:0% +T the not so small exponent it starts up + + + align:start position:0% +T the not so small exponent it starts up +that line but T is increasing as T when + + align:start position:0% +that line but T is increasing as T when + + + align:start position:0% +that line but T is increasing as T when +T passes some point this 2T will be + + align:start position:0% +T passes some point this 2T will be + + + align:start position:0% +T passes some point this 2T will be +bigger than T and uh uh it will I guess + + align:start position:0% +bigger than T and uh uh it will I guess + + + align:start position:0% +bigger than T and uh uh it will I guess +T at T equals zero 2T will be bigger + + align:start position:0% +T at T equals zero 2T will be bigger + + + align:start position:0% +T at T equals zero 2T will be bigger +than T and from that point on from the T + + align:start position:0% +than T and from that point on from the T + + + align:start position:0% +than T and from that point on from the T +equals z point oh I could even plot that + + align:start position:0% +equals z point oh I could even plot that + + + align:start position:0% +equals z point oh I could even plot that +t equals z so at t equal 0 Y is 2 and Y + + align:start position:0% +t equals z so at t equal 0 Y is 2 and Y + + + align:start position:0% +t equals z so at t equal 0 Y is 2 and Y +Prime is 3 so 1 two one two 3 somewhere + + align:start position:0% +Prime is 3 so 1 two one two 3 somewhere + + + align:start position:0% +Prime is 3 so 1 two one two 3 somewhere +in there is so you see it the the curve + + align:start position:0% +in there is so you see it the the curve + + + align:start position:0% +in there is so you see it the the curve +starts + + align:start position:0% +starts + + + align:start position:0% +starts +up along the line + + align:start position:0% +up along the line + + + align:start position:0% +up along the line +where where e to the t is + + align:start position:0% +where where e to the t is + + + align:start position:0% +where where e to the t is +bigger they they have the same size at T + + align:start position:0% +bigger they they have the same size at T + + + align:start position:0% +bigger they they have the same size at T +equals 0 both equal one this is at T + + align:start position:0% +equals 0 both equal one this is at T + + + align:start position:0% +equals 0 both equal one this is at T +equals 0 and + + align:start position:0% +equals 0 and + + + align:start position:0% +equals 0 and +then the for large times this one wins + + align:start position:0% +then the for large times this one wins + + + align:start position:0% +then the for large times this one wins +so I approach that line I don't know if + + align:start position:0% +so I approach that line I don't know if + + + align:start position:0% +so I approach that line I don't know if +you can see that curve I I and I don't + + align:start position:0% +you can see that curve I I and I don't + + + align:start position:0% +you can see that curve I I and I don't +swear to the slopes of that curve but in + + align:start position:0% +swear to the slopes of that curve but in + + + align:start position:0% +swear to the slopes of that curve but in +between in in there is filled with + + align:start position:0% +between in in there is filled with + + + align:start position:0% +between in in there is filled with +curves that start out with this slope + + align:start position:0% +curves that start out with this slope + + + align:start position:0% +curves that start out with this slope +and end with that slope and the same + + align:start position:0% +and end with that slope and the same + + + align:start position:0% +and end with that slope and the same +here it'll start with this slope but + + align:start position:0% +here it'll start with this slope but + + + align:start position:0% +here it'll start with this slope but +then go yeah probably this is a better + + align:start position:0% +then go yeah probably this is a better + + + align:start position:0% +then go yeah probably this is a better +picture yeah yeah that's a better + + align:start position:0% +picture yeah yeah that's a better + + + align:start position:0% +picture yeah yeah that's a better +picture yeah it doesn't it it will just + + align:start position:0% +picture yeah it doesn't it it will just + + + align:start position:0% +picture yeah it doesn't it it will just +go up with + + align:start position:0% +go up with + + + align:start position:0% +go up with +slope at the end it will have slope two + + align:start position:0% +slope at the end it will have slope two + + + align:start position:0% +slope at the end it will have slope two +going + + align:start position:0% +going + + + align:start position:0% +going +upwards yeah that looks good well you + + align:start position:0% +upwards yeah that looks good well you + + + align:start position:0% +upwards yeah that looks good well you +could say I only Drew part of the phase + + align:start position:0% +could say I only Drew part of the phase + + + align:start position:0% +could say I only Drew part of the phase +plane and you're completely right if I + + align:start position:0% +plane and you're completely right if I + + + align:start position:0% +plane and you're completely right if I +start somewhere here what would you + + align:start position:0% +start somewhere here what would you + + + align:start position:0% +start somewhere here what would you +think would happen what would you think + + align:start position:0% +think would happen what would you think + + + align:start position:0% +think would happen what would you think +would happen if I start with that value + + align:start position:0% +would happen if I start with that value + + + align:start position:0% +would happen if I start with that value +of y that much and that value of y prime + + align:start position:0% +of y that much and that value of y prime + + + align:start position:0% +of y that much and that value of y prime +it would have some mixture + + align:start position:0% +it would have some mixture + + + align:start position:0% +it would have some mixture +of of there would be a C1 and a + + align:start position:0% +of of there would be a C1 and a + + + align:start position:0% +of of there would be a C1 and a +C2 so the other curves that I haven't + + align:start position:0% +C2 so the other curves that I haven't + + + align:start position:0% +C2 so the other curves that I haven't +drawn yet come from the other C1 and C2 + + align:start position:0% +drawn yet come from the other C1 and C2 + + + align:start position:0% +drawn yet come from the other C1 and C2 +I've done C1 equal 1 and C2 equal 1 and + + align:start position:0% +I've done C1 equal 1 and C2 equal 1 and + + + align:start position:0% +I've done C1 equal 1 and C2 equal 1 and +C1 equal C2 equal 1 but now I have many + + align:start position:0% +C1 equal C2 equal 1 but now I have many + + + align:start position:0% +C1 equal C2 equal 1 but now I have many +more possibilities and what they do is + + align:start position:0% +more possibilities and what they do is + + + align:start position:0% +more possibilities and what they do is +they will uh so suppose I start there it + + align:start position:0% +they will uh so suppose I start there it + + + align:start position:0% +they will uh so suppose I start there it +will start out uh at it will approach + + align:start position:0% +will start out uh at it will approach + + + align:start position:0% +will start out uh at it will approach +the + + align:start position:0% +the + + + align:start position:0% +the +the this is the winner this is the + + align:start position:0% +the this is the winner this is the + + + align:start position:0% +the this is the winner this is the +winner this is this is the where C1 is + + align:start position:0% +winner this is this is the where C1 is + + + align:start position:0% +winner this is this is the where C1 is +one where where this is happening there + + align:start position:0% +one where where this is happening there + + + align:start position:0% +one where where this is happening there +there is the winner for a large time so + + align:start position:0% +there is the winner for a large time so + + + align:start position:0% +there is the winner for a large time so +all curves swing up toward that to + + align:start position:0% +all curves swing up toward that to + + + align:start position:0% +all curves swing up toward that to +parallel to that + + align:start position:0% + + + + align:start position:0% + +line or down here they swing down + + align:start position:0% +line or down here they swing down + + + align:start position:0% +line or down here they swing down +parallel to that line so things here + + align:start position:0% +parallel to that line so things here + + + align:start position:0% +parallel to that line so things here +will swing down this + + align:start position:0% + + + + align:start position:0% + +way that's the phase plane may I do one + + align:start position:0% +way that's the phase plane may I do one + + + align:start position:0% +way that's the phase plane may I do one +more example to show that this was a + + align:start position:0% +more example to show that this was a + + + align:start position:0% +more example to show that this was a +source this is called a source + + align:start position:0% +source this is called a source + + + align:start position:0% +source this is called a source +because the + + align:start position:0% +because the + + + align:start position:0% +because the +the the solution goes to Infinity + + align:start position:0% +the the solution goes to Infinity + + + align:start position:0% +the the solution goes to Infinity +wherever you start the solution goes to + + align:start position:0% +wherever you start the solution goes to + + + align:start position:0% +wherever you start the solution goes to +Infinity it's un totally + + align:start position:0% +Infinity it's un totally + + + align:start position:0% +Infinity it's un totally +unstable now if I changed to a positive + + align:start position:0% +unstable now if I changed to a positive + + + align:start position:0% +unstable now if I changed to a positive +damping then I would have a plus sign + + align:start position:0% +damping then I would have a plus sign + + + align:start position:0% +damping then I would have a plus sign +there these would be plus signs I would + + align:start position:0% +there these would be plus signs I would + + + align:start position:0% +there these would be plus signs I would +have S = minus1 or S equal -2 so with + + align:start position:0% +have S = minus1 or S equal -2 so with + + + align:start position:0% +have S = minus1 or S equal -2 so with +positive damping I damp out naturally + + align:start position:0% +positive damping I damp out naturally + + + align:start position:0% +positive damping I damp out naturally +and the all the this picture would be + + align:start position:0% +and the all the this picture would be + + + align:start position:0% +and the all the this picture would be +the same except all the lines are coming + + align:start position:0% +the same except all the lines are coming + + + align:start position:0% +the same except all the lines are coming +into to 0 0 the solutions are damping to + + align:start position:0% +into to 0 0 the solutions are damping to + + + align:start position:0% +into to 0 0 the solutions are damping to +0 0 to nothing happen happening so I + + align:start position:0% +0 0 to nothing happen happening so I + + + align:start position:0% +0 0 to nothing happen happening so I +just track the same lines but in the + + align:start position:0% +just track the same lines but in the + + + align:start position:0% +just track the same lines but in the +opposite direction into so instead of + + align:start position:0% +opposite direction into so instead of + + + align:start position:0% +opposite direction into so instead of +this being the Big Bang it's the end of + + align:start position:0% +this being the Big Bang it's the end of + + + align:start position:0% +this being the Big Bang it's the end of +the universe t equal + + align:start position:0% +the universe t equal + + + align:start position:0% +the universe t equal +Infinity okay I'm up for one more + + align:start position:0% +Infinity okay I'm up for one more + + + align:start position:0% +Infinity okay I'm up for one more +picture of this uh possibility and let + + align:start position:0% +picture of this uh possibility and let + + + align:start position:0% +picture of this uh possibility and let +me take the equation Y + + align:start position:0% +me take the equation Y + + + align:start position:0% +me take the equation Y +Prime = 4 + + align:start position:0% +Prime = 4 + + + align:start position:0% +Prime = 4 +y so my equation will be + + align:start position:0% +y so my equation will be + + + align:start position:0% +y so my equation will be +s² = 4 4 S = 2 or -2 and when I draw the + + align:start position:0% +s² = 4 4 S = 2 or -2 and when I draw the + + + align:start position:0% +s² = 4 4 S = 2 or -2 and when I draw the +phase + + align:start position:0% +phase + + + align:start position:0% +phase +plane when the and the solutions the + + align:start position:0% +plane when the and the solutions the + + + align:start position:0% +plane when the and the solutions the +solutions will be C1 e to the + + align:start position:0% +solutions will be C1 e to the + + + align:start position:0% +solutions will be C1 e to the +2T and C2 e to Theus 2T from a two and a + + align:start position:0% +2T and C2 e to Theus 2T from a two and a + + + align:start position:0% +2T and C2 e to Theus 2T from a two and a +minus 2 that's the that's the solution + + align:start position:0% +minus 2 that's the that's the solution + + + align:start position:0% +minus 2 that's the that's the solution +we all know and now I should compute its + + align:start position:0% +we all know and now I should compute its + + + align:start position:0% +we all know and now I should compute its +slope y Prime will be 2 C1 1 E to 2T + + align:start position:0% +slope y Prime will be 2 C1 1 E to 2T + + + align:start position:0% +slope y Prime will be 2 C1 1 E to 2T +minus 2 C2 e to 2T and now you just want + + align:start position:0% +minus 2 C2 e to 2T and now you just want + + + align:start position:0% +minus 2 C2 e to 2T and now you just want +me to draw those pictures you just want + + align:start position:0% +me to draw those pictures you just want + + + align:start position:0% +me to draw those pictures you just want +me to draw those pictures and let me try + + align:start position:0% +me to draw those pictures and let me try + + + align:start position:0% +me to draw those pictures and let me try +to say what happens here uh this is this + + align:start position:0% +to say what happens here uh this is this + + + align:start position:0% +to say what happens here uh this is this +is a saddle point it's called a saddle + + align:start position:0% +is a saddle point it's called a saddle + + + align:start position:0% +is a saddle point it's called a saddle +when we have in One Direction things are + + align:start position:0% +when we have in One Direction things are + + + align:start position:0% +when we have in One Direction things are +growing but in the other things are + + align:start position:0% +growing but in the other things are + + + align:start position:0% +growing but in the other things are +decreasing so uh mostly + + align:start position:0% +decreasing so uh mostly + + + align:start position:0% +decreasing so uh mostly +most solutions if C1 is not zero then + + align:start position:0% +most solutions if C1 is not zero then + + + align:start position:0% +most solutions if C1 is not zero then +the growth is going to win and that will + + align:start position:0% +the growth is going to win and that will + + + align:start position:0% +the growth is going to win and that will +disappear but there is the possibility + + align:start position:0% +disappear but there is the possibility + + + align:start position:0% +disappear but there is the possibility +that C1 is zero so there will be one + + align:start position:0% +that C1 is zero so there will be one + + + align:start position:0% +that C1 is zero so there will be one +line coming from there there' be one + + align:start position:0% +line coming from there there' be one + + + align:start position:0% +line coming from there there' be one +line coming from there maybe I can try + + align:start position:0% +line coming from there maybe I can try + + + align:start position:0% +line coming from there maybe I can try +to draw that I'll again I'll draw that + + align:start position:0% +to draw that I'll again I'll draw that + + + align:start position:0% +to draw that I'll again I'll draw that +Pure Line where where C1 is zero so that + + align:start position:0% +Pure Line where where C1 is zero so that + + + align:start position:0% +Pure Line where where C1 is zero so that +Pure Line is coming these are minuses + + align:start position:0% +Pure Line is coming these are minuses + + + align:start position:0% +Pure Line is coming these are minuses +here so that line is coming into the + + align:start position:0% +here so that line is coming into the + + + align:start position:0% +here so that line is coming into the +center so that's why we have a saddle we + + align:start position:0% +center so that's why we have a saddle we + + + align:start position:0% +center so that's why we have a saddle we +we approach the saddle uh if along this + + align:start position:0% +we approach the saddle uh if along this + + + align:start position:0% +we approach the saddle uh if along this +where where where this is minus two of + + align:start position:0% +where where where this is minus two of + + + align:start position:0% +where where where this is minus two of +that so I think it would be so it's a + + align:start position:0% +that so I think it would be so it's a + + + align:start position:0% +that so I think it would be so it's a +slope of Min + + align:start position:0% +slope of Min + + + align:start position:0% +slope of Min +-2 so I think so slope like + + align:start position:0% +-2 so I think so slope like + + + align:start position:0% +-2 so I think so slope like +that so again this is y this is y Prime + + align:start position:0% +that so again this is y this is y Prime + + + align:start position:0% +that so again this is y this is y Prime +this is the slope of Min + + align:start position:0% + + + + align:start position:0% + +-2 and that's this curve and + + align:start position:0% +-2 and that's this curve and + + + align:start position:0% +-2 and that's this curve and +uh uh yeah so so it will be very + + align:start position:0% +uh uh yeah so so it will be very + + + align:start position:0% +uh uh yeah so so it will be very +exceptional that we're just follow that + + align:start position:0% +exceptional that we're just follow that + + + align:start position:0% +exceptional that we're just follow that +we're right on that line all + + align:start position:0% +we're right on that line all + + + align:start position:0% +we're right on that line all +other points all other Curves in this + + align:start position:0% +other points all other Curves in this + + + align:start position:0% +other points all other Curves in this +phase plane are going to have a little + + align:start position:0% +phase plane are going to have a little + + + align:start position:0% +phase plane are going to have a little +C1 in them and then this will take over + + align:start position:0% +C1 in them and then this will take over + + + align:start position:0% +C1 in them and then this will take over +and that is gives us as we saw before + + align:start position:0% +and that is gives us as we saw before + + + align:start position:0% +and that is gives us as we saw before +this slope is this is two times that so + + align:start position:0% +this slope is this is two times that so + + + align:start position:0% +this slope is this is two times that so +that line is the is where everybody + + align:start position:0% +that line is the is where everybody + + + align:start position:0% +that line is the is where everybody +wants to go and only if you start + + align:start position:0% +wants to go and only if you start + + + align:start position:0% +wants to go and only if you start +exactly on this line do you do you get + + align:start position:0% +exactly on this line do you do you get + + + align:start position:0% +exactly on this line do you do you get +this picture and you come in to the S + + align:start position:0% +this picture and you come in to the S + + + align:start position:0% +this picture and you come in to the S +there's the instead of the Big Bang or + + align:start position:0% +there's the instead of the Big Bang or + + + align:start position:0% +there's the instead of the Big Bang or +the end of the universe this is now the + + align:start position:0% +the end of the universe this is now the + + + align:start position:0% +the end of the universe this is now the +saddle point where we come in on this + + align:start position:0% +saddle point where we come in on this + + + align:start position:0% +saddle point where we come in on this +most special of all lines coming from + + align:start position:0% +most special of all lines coming from + + + align:start position:0% +most special of all lines coming from +this picture but almost always this is + + align:start position:0% +this picture but almost always this is + + + align:start position:0% +this picture but almost always this is +the dominant thing and we go out so so + + align:start position:0% +the dominant thing and we go out so so + + + align:start position:0% +the dominant thing and we go out so so +if I take a typical starting point I'll + + align:start position:0% +if I take a typical starting point I'll + + + align:start position:0% +if I take a typical starting point I'll +go out + + align:start position:0% +go out + + + align:start position:0% +go out +this like + + align:start position:0% +this like + + + align:start position:0% +this like +that or like this oh no uh yep no I'll + + align:start position:0% +that or like this oh no uh yep no I'll + + + align:start position:0% +that or like this oh no uh yep no I'll +go out it'll have to go out so if I + + align:start position:0% +go out it'll have to go out so if I + + + align:start position:0% +go out it'll have to go out so if I +start anywhere here these are probably + + align:start position:0% +start anywhere here these are probably + + + align:start position:0% +start anywhere here these are probably +their + + align:start position:0% +their + + + align:start position:0% +their +hyperbolas uh going out in that + + align:start position:0% +hyperbolas uh going out in that + + + align:start position:0% +hyperbolas uh going out in that +direction I don't swear that they're + + align:start position:0% +direction I don't swear that they're + + + align:start position:0% +direction I don't swear that they're +hyperbolas here again we might start in + + align:start position:0% +hyperbolas here again we might start in + + + align:start position:0% +hyperbolas here again we might start in +because we have a big numers here but + + align:start position:0% +because we have a big numers here but + + + align:start position:0% +because we have a big numers here but +then e to the T takes over and we go out + + align:start position:0% +then e to the T takes over and we go out + + + align:start position:0% +then e to the T takes over and we go out +so those go out these go + + align:start position:0% +so those go out these go + + + align:start position:0% +so those go out these go +out and these go out yeah so this is the + + align:start position:0% +out and these go out yeah so this is the + + + align:start position:0% +out and these go out yeah so this is the +big line that's the line coming from + + align:start position:0% +big line that's the line coming from + + + align:start position:0% +big line that's the line coming from +here and that's where everything wants + + align:start position:0% +here and that's where everything wants + + + align:start position:0% +here and that's where everything wants +to go and everything eventually goes + + align:start position:0% +to go and everything eventually goes + + + align:start position:0% +to go and everything eventually goes +that way except the one line where C1 is + + align:start position:0% +that way except the one line where C1 is + + + align:start position:0% +that way except the one line where C1 is +zero so the that this dominant term is + + align:start position:0% +zero so the that this dominant term is + + + align:start position:0% +zero so the that this dominant term is +not even here then and then we come + + align:start position:0% +not even here then and then we come + + + align:start position:0% +not even here then and then we come +inwards so that saddle point is a a the + + align:start position:0% +inwards so that saddle point is a a the + + + align:start position:0% +inwards so that saddle point is a a the +special point where you could go out if + + align:start position:0% +special point where you could go out if + + + align:start position:0% +special point where you could go out if +if you go the right way or you could + + align:start position:0% +if you go the right way or you could + + + align:start position:0% +if you go the right way or you could +come in if you go the other special + + align:start position:0% +come in if you go the other special + + + align:start position:0% +come in if you go the other special +special + + align:start position:0% +special + + + align:start position:0% +special +way okay so that's sources sinks and + + align:start position:0% +way okay so that's sources sinks and + + + align:start position:0% +way okay so that's sources sinks and +Saddles and I still have to draw the + + align:start position:0% +Saddles and I still have to draw the + + + align:start position:0% +Saddles and I still have to draw the +pictures which involve spirals that come + + align:start position:0% +pictures which involve spirals that come + + + align:start position:0% +pictures which involve spirals that come +from complex s where we have oscillation + + align:start position:0% +from complex s where we have oscillation + + + align:start position:0% +from complex s where we have oscillation +that'll be the next video \ No newline at end of file diff --git a/W-7gI87IG1A.txt b/W-7gI87IG1A.txt new file mode 100644 index 0000000000000000000000000000000000000000..0ebb15cbf36ba1d07c2d1eb6cf6329c4d3fac459 --- /dev/null +++ b/W-7gI87IG1A.txt @@ -0,0 +1,18344 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license your support + + align:start position:0% +a creative commons license your support + + + align:start position:0% +a creative commons license your support +will help mit opencourseware continue to + + align:start position:0% +will help mit opencourseware continue to + + + align:start position:0% +will help mit opencourseware continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +yeah so today's class we are going to + + align:start position:0% +yeah so today's class we are going to + + + align:start position:0% +yeah so today's class we are going to +talk about uh + + align:start position:0% +talk about uh + + + align:start position:0% +talk about uh +coherence and + + align:start position:0% +coherence and + + + align:start position:0% +coherence and +basically as + + align:start position:0% +basically as + + + align:start position:0% +basically as +foreign system within current imaging so + + align:start position:0% +foreign system within current imaging so + + + align:start position:0% +foreign system within current imaging so +particularly this topic is very + + align:start position:0% +particularly this topic is very + + + align:start position:0% +particularly this topic is very +important if you want to take optic + + align:start position:0% +important if you want to take optic + + + align:start position:0% +important if you want to take optic +score because you know we're dealing + + align:start position:0% +score because you know we're dealing + + + align:start position:0% +score because you know we're dealing +with coherence and in korean so + + align:start position:0% +with coherence and in korean so + + + align:start position:0% +with coherence and in korean so +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so + + align:start position:0% +so + + + align:start position:0% +so +so far we have deal with the 4f system + + align:start position:0% +so far we have deal with the 4f system + + + align:start position:0% +so far we have deal with the 4f system +with the with a coherent illumination + + align:start position:0% +with the with a coherent illumination + + + align:start position:0% +with the with a coherent illumination +basically a laser light + + align:start position:0% +basically a laser light + + + align:start position:0% +basically a laser light +from a point source i mean pinhole so + + align:start position:0% +from a point source i mean pinhole so + + + align:start position:0% +from a point source i mean pinhole so +the + + align:start position:0% +the + + + align:start position:0% +the +the coherent + + align:start position:0% +the coherent + + + align:start position:0% +the coherent +coherent plane waves are illuminating + + align:start position:0% +coherent plane waves are illuminating + + + align:start position:0% +coherent plane waves are illuminating +the voice system + + align:start position:0% +the voice system + + + align:start position:0% +the voice system +and + + align:start position:0% +and + + + align:start position:0% +and +the frequency content appear at the free + + align:start position:0% +the frequency content appear at the free + + + align:start position:0% +the frequency content appear at the free +up plane and you can put the put the + + align:start position:0% +up plane and you can put the put the + + + align:start position:0% +up plane and you can put the put the +pupil mask to play with the + + align:start position:0% + + + + align:start position:0% + +you know the spatial filtering and + + align:start position:0% +you know the spatial filtering and + + + align:start position:0% +you know the spatial filtering and +you're going to get some + + align:start position:0% +you're going to get some + + + align:start position:0% +you're going to get some +image at the alpha plane but + + align:start position:0% +image at the alpha plane but + + + align:start position:0% +image at the alpha plane but +you know in everyday life if you + + align:start position:0% +you know in everyday life if you + + + align:start position:0% +you know in everyday life if you +use your digital camera you're not using + + align:start position:0% +use your digital camera you're not using + + + align:start position:0% +use your digital camera you're not using +the really + + align:start position:0% +the really + + + align:start position:0% +the really +laser elimination right you mostly use + + align:start position:0% +laser elimination right you mostly use + + + align:start position:0% +laser elimination right you mostly use +this ambient light or + + align:start position:0% +this ambient light or + + + align:start position:0% +this ambient light or +if it's too dark then you're use you're + + align:start position:0% +if it's too dark then you're use you're + + + align:start position:0% +if it's too dark then you're use you're +going to use the flash uh light + + align:start position:0% +going to use the flash uh light + + + align:start position:0% +going to use the flash uh light +so + + align:start position:0% +so + + + align:start position:0% +so +so today we are going to talk about more + + align:start position:0% +so today we are going to talk about more + + + align:start position:0% +so today we are going to talk about more +realistic case we use the in korean + + align:start position:0% +realistic case we use the in korean + + + align:start position:0% +realistic case we use the in korean +light by the way the difference between + + align:start position:0% +light by the way the difference between + + + align:start position:0% +light by the way the difference between +coherent and in colon is + + align:start position:0% +coherent and in colon is + + + align:start position:0% +coherent and in colon is +basically you can make the interference + + align:start position:0% +basically you can make the interference + + + align:start position:0% +basically you can make the interference +with the coherent light right so if you + + align:start position:0% +with the coherent light right so if you + + + align:start position:0% +with the coherent light right so if you +want to make interference you're using + + align:start position:0% +want to make interference you're using + + + align:start position:0% +want to make interference you're using +laser + + align:start position:0% +laser + + + align:start position:0% +laser +but in most cases like this white light + + align:start position:0% +but in most cases like this white light + + + align:start position:0% +but in most cases like this white light +source you are not going to see + + align:start position:0% +source you are not going to see + + + align:start position:0% +source you are not going to see +interference so + + align:start position:0% +interference so + + + align:start position:0% +interference so +we are going to first we are going to + + align:start position:0% +we are going to first we are going to + + + align:start position:0% +we are going to first we are going to +define what coherence is and there are + + align:start position:0% +define what coherence is and there are + + + align:start position:0% +define what coherence is and there are +actually there are two kind of coherence + + align:start position:0% +actually there are two kind of coherence + + + align:start position:0% +actually there are two kind of coherence +temporal coherence and spatial coherence + + align:start position:0% +temporal coherence and spatial coherence + + + align:start position:0% +temporal coherence and spatial coherence +and the rest of the topic is pretty + + align:start position:0% +and the rest of the topic is pretty + + + align:start position:0% +and the rest of the topic is pretty +straightforward we are going to define + + align:start position:0% +straightforward we are going to define + + + align:start position:0% +straightforward we are going to define +incoherent poinsettia function and + + align:start position:0% +incoherent poinsettia function and + + + align:start position:0% +incoherent poinsettia function and +and is free transform pair which is + + align:start position:0% +and is free transform pair which is + + + align:start position:0% +and is free transform pair which is +optical transfer function and modulation + + align:start position:0% +optical transfer function and modulation + + + align:start position:0% +optical transfer function and modulation +transfer function which is + + align:start position:0% +transfer function which is + + + align:start position:0% +transfer function which is +modulus of otf + + align:start position:0% +modulus of otf + + + align:start position:0% +modulus of otf +and + + align:start position:0% +and + + + align:start position:0% +and +we're gonna see what mtf mean and + + align:start position:0% +we're gonna see what mtf mean and + + + align:start position:0% +we're gonna see what mtf mean and +we're gonna compare the difference + + align:start position:0% +we're gonna compare the difference + + + align:start position:0% +we're gonna compare the difference +between especially in core hand and + + align:start position:0% +between especially in core hand and + + + align:start position:0% +between especially in core hand and +especially kohen and current imaging + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +so as i just described the coherence is + + align:start position:0% +so as i just described the coherence is + + + align:start position:0% +so as i just described the coherence is +basically uh popular ability to make + + align:start position:0% +basically uh popular ability to make + + + align:start position:0% +basically uh popular ability to make +interference so if you have incoherent + + align:start position:0% +interference so if you have incoherent + + + align:start position:0% +interference so if you have incoherent +light you cannot make interference and + + align:start position:0% +light you cannot make interference and + + + align:start position:0% +light you cannot make interference and +if you have coherent light then you can + + align:start position:0% +if you have coherent light then you can + + + align:start position:0% +if you have coherent light then you can +make the interference + + align:start position:0% +make the interference + + + align:start position:0% +make the interference +and + + align:start position:0% +and + + + align:start position:0% +and +i'm going to describe later but the + + align:start position:0% +i'm going to describe later but the + + + align:start position:0% +i'm going to describe later but the +mathematically + + align:start position:0% +mathematically + + + align:start position:0% +mathematically +actually the coherence is nothing but + + align:start position:0% +actually the coherence is nothing but + + + align:start position:0% +actually the coherence is nothing but +the correlation of + + align:start position:0% +the correlation of + + + align:start position:0% +the correlation of +wave at two + + align:start position:0% +wave at two + + + align:start position:0% +wave at two +time space point which means we have + + align:start position:0% +time space point which means we have + + + align:start position:0% +time space point which means we have +some light and you just + + align:start position:0% +some light and you just + + + align:start position:0% +some light and you just +sample two uh point it could be + + align:start position:0% +sample two uh point it could be + + + align:start position:0% +sample two uh point it could be +different + + align:start position:0% +different + + + align:start position:0% +different +different time points but you combine + + align:start position:0% +different time points but you combine + + + align:start position:0% +different time points but you combine +them and if you see interference then + + align:start position:0% +them and if you see interference then + + + align:start position:0% +them and if you see interference then +you can say it is coherent but if you + + align:start position:0% +you can say it is coherent but if you + + + align:start position:0% +you can say it is coherent but if you +don't see interference then + + align:start position:0% +don't see interference then + + + align:start position:0% +don't see interference then +in korean + + align:start position:0% +in korean + + + align:start position:0% +in korean +so first let me describe uh what's going + + align:start position:0% +so first let me describe uh what's going + + + align:start position:0% +so first let me describe uh what's going +to happen if i use the incurrent light + + align:start position:0% +to happen if i use the incurrent light + + + align:start position:0% +to happen if i use the incurrent light +in microsoft interferometer so here we + + align:start position:0% +in microsoft interferometer so here we + + + align:start position:0% +in microsoft interferometer so here we +have the microsoft interferometer so + + align:start position:0% +have the microsoft interferometer so + + + align:start position:0% +have the microsoft interferometer so +with the from the point source the light + + align:start position:0% + + + + align:start position:0% + +from the point source light is coming in + + align:start position:0% +from the point source light is coming in + + + align:start position:0% +from the point source light is coming in +this direction this direction and at the + + align:start position:0% +this direction this direction and at the + + + align:start position:0% +this direction this direction and at the +beam spiritual a half of the light just + + align:start position:0% +beam spiritual a half of the light just + + + align:start position:0% +beam spiritual a half of the light just +transmit the beam splitter but the other + + align:start position:0% +transmit the beam splitter but the other + + + align:start position:0% +transmit the beam splitter but the other +half is reflected + + align:start position:0% +half is reflected + + + align:start position:0% +half is reflected +so this path they reflect again at the + + align:start position:0% +so this path they reflect again at the + + + align:start position:0% +so this path they reflect again at the +mirror and pass through the vm splitter + + align:start position:0% +mirror and pass through the vm splitter + + + align:start position:0% +mirror and pass through the vm splitter +and arrives at the detector and the + + align:start position:0% +and arrives at the detector and the + + + align:start position:0% +and arrives at the detector and the +other path + + align:start position:0% +other path + + + align:start position:0% +other path +is reflected again and reflected at the + + align:start position:0% +is reflected again and reflected at the + + + align:start position:0% +is reflected again and reflected at the +beam filler and + + align:start position:0% +beam filler and + + + align:start position:0% +beam filler and +again you get i mean it is it arrives at + + align:start position:0% +again you get i mean it is it arrives at + + + align:start position:0% +again you get i mean it is it arrives at +the detector + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +let's just suppose that we have the + + align:start position:0% +let's just suppose that we have the + + + align:start position:0% +let's just suppose that we have the +laser uh source here then what we want + + align:start position:0% +laser uh source here then what we want + + + align:start position:0% +laser uh source here then what we want +to see at the detector is nice + + align:start position:0% +to see at the detector is nice + + + align:start position:0% +to see at the detector is nice +sinusoidal pattern if i move one of the + + align:start position:0% +sinusoidal pattern if i move one of the + + + align:start position:0% +sinusoidal pattern if i move one of the +mirror right because i can i tune the + + align:start position:0% +mirror right because i can i tune the + + + align:start position:0% +mirror right because i can i tune the +uh optical pass differ actually + + align:start position:0% +uh optical pass differ actually + + + align:start position:0% +uh optical pass differ actually +optical fast length + + align:start position:0% +optical fast length + + + align:start position:0% +optical fast length +that light travels and if the distance + + align:start position:0% +that light travels and if the distance + + + align:start position:0% +that light travels and if the distance +match then + + align:start position:0% +match then + + + align:start position:0% +match then +i get the constructive interference and + + align:start position:0% +i get the constructive interference and + + + align:start position:0% +i get the constructive interference and +the base delay uh + + align:start position:0% +the base delay uh + + + align:start position:0% +the base delay uh +pi then i get destructive interference + + align:start position:0% +pi then i get destructive interference + + + align:start position:0% +pi then i get destructive interference +so as i move to one of the mirror i get + + align:start position:0% +so as i move to one of the mirror i get + + + align:start position:0% +so as i move to one of the mirror i get +nice sinusoidal pattern with the full + + align:start position:0% +nice sinusoidal pattern with the full + + + align:start position:0% +nice sinusoidal pattern with the full +contrast + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +next + + align:start position:0% +next + + + align:start position:0% +next +let's suppose instead of the laser i + + align:start position:0% +let's suppose instead of the laser i + + + align:start position:0% +let's suppose instead of the laser i +have uh in current source which means so + + align:start position:0% +have uh in current source which means so + + + align:start position:0% +have uh in current source which means so +the horizontal axis is time and the + + align:start position:0% +the horizontal axis is time and the + + + align:start position:0% +the horizontal axis is time and the +vertical axis is amplitude but the the + + align:start position:0% +vertical axis is amplitude but the the + + + align:start position:0% +vertical axis is amplitude but the the +phase or amplitudes are varying randomly + + align:start position:0% +phase or amplitudes are varying randomly + + + align:start position:0% +phase or amplitudes are varying randomly +so + + align:start position:0% +so + + + align:start position:0% +so +over time time the amplitudes are very + + align:start position:0% +over time time the amplitudes are very + + + align:start position:0% +over time time the amplitudes are very +very very + + align:start position:0% +very very + + + align:start position:0% +very very +you know + + align:start position:0% + + + + align:start position:0% + +randomly + + align:start position:0% +randomly + + + align:start position:0% +randomly +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +and + + align:start position:0% + + + + align:start position:0% + +even though it's random this wave trend + + align:start position:0% +even though it's random this wave trend + + + align:start position:0% +even though it's random this wave trend +will + + align:start position:0% +will + + + align:start position:0% +will +travel + + align:start position:0% +travel + + + align:start position:0% +travel +through the interferometer so + + align:start position:0% + + + + align:start position:0% + +in this path + + align:start position:0% +in this path + + + align:start position:0% +in this path +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +optical path + + align:start position:0% +optical path + + + align:start position:0% +optical path +length is actually constant which is i + + align:start position:0% +length is actually constant which is i + + + align:start position:0% +length is actually constant which is i +mean these paths are the they're common + + align:start position:0% +mean these paths are the they're common + + + align:start position:0% +mean these paths are the they're common +in two paths so constant plus 2 d 1 over + + align:start position:0% +in two paths so constant plus 2 d 1 over + + + align:start position:0% +in two paths so constant plus 2 d 1 over +c which is time speed of light + + align:start position:0% +c which is time speed of light + + + align:start position:0% +c which is time speed of light +and + + align:start position:0% +and + + + align:start position:0% +and +in the second path i have the same this + + align:start position:0% +in the second path i have the same this + + + align:start position:0% +in the second path i have the same this +little trim also travel but + + align:start position:0% +little trim also travel but + + + align:start position:0% +little trim also travel but +due to the difference between a t1 and + + align:start position:0% +due to the difference between a t1 and + + + align:start position:0% +due to the difference between a t1 and +d2 i mean at a detector + + align:start position:0% +d2 i mean at a detector + + + align:start position:0% +d2 i mean at a detector +essentially i'm going to sample a + + align:start position:0% +essentially i'm going to sample a + + + align:start position:0% +essentially i'm going to sample a +different time point right so + + align:start position:0% +different time point right so + + + align:start position:0% +different time point right so +even though it's random + + align:start position:0% +even though it's random + + + align:start position:0% +even though it's random +i basically choose two time + + align:start position:0% +i basically choose two time + + + align:start position:0% +i basically choose two time +points + + align:start position:0% +points + + + align:start position:0% +points +here and here and combine them at the + + align:start position:0% +here and here and combine them at the + + + align:start position:0% +here and here and combine them at the +detector right + + align:start position:0% +detector right + + + align:start position:0% +detector right +so + + align:start position:0% +so + + + align:start position:0% +so +if d1 and d2 are same then basically two + + align:start position:0% +if d1 and d2 are same then basically two + + + align:start position:0% +if d1 and d2 are same then basically two +basically identical two waves are coming + + align:start position:0% +basically identical two waves are coming + + + align:start position:0% +basically identical two waves are coming +together so i always get constructed + + align:start position:0% +together so i always get constructed + + + align:start position:0% +together so i always get constructed +interference + + align:start position:0% +interference + + + align:start position:0% +interference +but what if d1 and d2 are not same + + align:start position:0% +but what if d1 and d2 are not same + + + align:start position:0% +but what if d1 and d2 are not same +and + + align:start position:0% +and + + + align:start position:0% +and +then basically they get different phase + + align:start position:0% +then basically they get different phase + + + align:start position:0% +then basically they get different phase +shifts right and since it's random so + + align:start position:0% +shifts right and since it's random so + + + align:start position:0% +shifts right and since it's random so +they are kind of the average out so d1 + + align:start position:0% +they are kind of the average out so d1 + + + align:start position:0% +they are kind of the average out so d1 +and d2 are getting bigger then + + align:start position:0% +and d2 are getting bigger then + + + align:start position:0% +and d2 are getting bigger then +basically the degree of correlation is + + align:start position:0% +basically the degree of correlation is + + + align:start position:0% +basically the degree of correlation is +get is getting decreased and which means + + align:start position:0% +get is getting decreased and which means + + + align:start position:0% +get is getting decreased and which means +at the detector the contrast + + align:start position:0% +at the detector the contrast + + + align:start position:0% +at the detector the contrast +will also get decreased + + align:start position:0% +will also get decreased + + + align:start position:0% +will also get decreased +so if i plot the intensity at the + + align:start position:0% +so if i plot the intensity at the + + + align:start position:0% +so if i plot the intensity at the +detector + + align:start position:0% +detector + + + align:start position:0% +detector +with respect to d2 minus t1 which is the + + align:start position:0% +with respect to d2 minus t1 which is the + + + align:start position:0% +with respect to d2 minus t1 which is the +the distance difference of true arm + + align:start position:0% +the distance difference of true arm + + + align:start position:0% +the distance difference of true arm +then the intensity is going to be like + + align:start position:0% +then the intensity is going to be like + + + align:start position:0% +then the intensity is going to be like +this + + align:start position:0% +this + + + align:start position:0% +this +so + + align:start position:0% +so + + + align:start position:0% +so +remember that if we if if i have the + + align:start position:0% +remember that if we if if i have the + + + align:start position:0% +remember that if we if if i have the +laser at + + align:start position:0% +laser at + + + align:start position:0% +laser at +point source then i will get + + align:start position:0% +point source then i will get + + + align:start position:0% +point source then i will get +the sinusoidal pattern with the full + + align:start position:0% +the sinusoidal pattern with the full + + + align:start position:0% +the sinusoidal pattern with the full +contrast but + + align:start position:0% +contrast but + + + align:start position:0% +contrast but +since now i have random randomly varying + + align:start position:0% +since now i have random randomly varying + + + align:start position:0% +since now i have random randomly varying +source + + align:start position:0% +source + + + align:start position:0% +source +those this envelope is getting + + align:start position:0% +those this envelope is getting + + + align:start position:0% +those this envelope is getting +attenuated like this so if i have the + + align:start position:0% +attenuated like this so if i have the + + + align:start position:0% +attenuated like this so if i have the +rapid more rapid decay curve which means + + align:start position:0% +rapid more rapid decay curve which means + + + align:start position:0% +rapid more rapid decay curve which means +i have more incoherent light right and + + align:start position:0% +i have more incoherent light right and + + + align:start position:0% +i have more incoherent light right and +if i have the + + align:start position:0% +if i have the + + + align:start position:0% +if i have the +slowly decaying envelope then it's more + + align:start position:0% +slowly decaying envelope then it's more + + + align:start position:0% +slowly decaying envelope then it's more +coherent + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +there is another + + align:start position:0% +there is another + + + align:start position:0% +there is another +uh + + align:start position:0% +uh + + + align:start position:0% +uh +kind of coherence which is special + + align:start position:0% +kind of coherence which is special + + + align:start position:0% +kind of coherence which is special +coherence so basically the concept is + + align:start position:0% +coherence so basically the concept is + + + align:start position:0% +coherence so basically the concept is +same but we only define the correlation + + align:start position:0% +same but we only define the correlation + + + align:start position:0% +same but we only define the correlation +in space domain + + align:start position:0% +in space domain + + + align:start position:0% +in space domain +so now we i i have the young + + align:start position:0% +so now we i i have the young + + + align:start position:0% +so now we i i have the young +interferometer i have the two pin on x1 + + align:start position:0% +interferometer i have the two pin on x1 + + + align:start position:0% +interferometer i have the two pin on x1 +and x2 and i put a detector at the + + align:start position:0% +and x2 and i put a detector at the + + + align:start position:0% +and x2 and i put a detector at the +center of the two pinhole so + + align:start position:0% +center of the two pinhole so + + + align:start position:0% +center of the two pinhole so +from + + align:start position:0% +from + + + align:start position:0% +from +so from this panel + + align:start position:0% +so from this panel + + + align:start position:0% +so from this panel +you see i mean + + align:start position:0% +you see i mean + + + align:start position:0% +you see i mean +the spherical wave + + align:start position:0% +the spherical wave + + + align:start position:0% +the spherical wave +is going to be emanating but + + align:start position:0% +is going to be emanating but + + + align:start position:0% +is going to be emanating but +since it is at the center these paths + + align:start position:0% +since it is at the center these paths + + + align:start position:0% +since it is at the center these paths +are exactly the same + + align:start position:0% +are exactly the same + + + align:start position:0% +are exactly the same +and first let's suppose we have a laser + + align:start position:0% +and first let's suppose we have a laser + + + align:start position:0% +and first let's suppose we have a laser +illumination so i have + + align:start position:0% +illumination so i have + + + align:start position:0% +illumination so i have +the plane f coming in then this + + align:start position:0% +the plane f coming in then this + + + align:start position:0% +the plane f coming in then this +spherical wave will make the young's + + align:start position:0% +spherical wave will make the young's + + + align:start position:0% +spherical wave will make the young's +interference right so i'm going to have + + align:start position:0% +interference right so i'm going to have + + + align:start position:0% +interference right so i'm going to have +a sinusoidal + + align:start position:0% +a sinusoidal + + + align:start position:0% +a sinusoidal +pattern with the full contrast at this + + align:start position:0% +pattern with the full contrast at this + + + align:start position:0% +pattern with the full contrast at this +plane but i'm just seeing at one point + + align:start position:0% +plane but i'm just seeing at one point + + + align:start position:0% +plane but i'm just seeing at one point +and + + align:start position:0% +and + + + align:start position:0% +and +again if i have the random randomly + + align:start position:0% +again if i have the random randomly + + + align:start position:0% +again if i have the random randomly +varying uh + + align:start position:0% +varying uh + + + align:start position:0% +varying uh +wave here + + align:start position:0% +wave here + + + align:start position:0% +wave here +so in this case + + align:start position:0% +so in this case + + + align:start position:0% +so in this case +this horizontal axis + + align:start position:0% +this horizontal axis + + + align:start position:0% +this horizontal axis +amplitude and vertical axis is space + + align:start position:0% +amplitude and vertical axis is space + + + align:start position:0% +amplitude and vertical axis is space +instead of time + + align:start position:0% +instead of time + + + align:start position:0% +instead of time +so this + + align:start position:0% +so this + + + align:start position:0% +so this +amplitude and phase are varying randomly + + align:start position:0% +amplitude and phase are varying randomly + + + align:start position:0% +amplitude and phase are varying randomly +varying over space + + align:start position:0% +varying over space + + + align:start position:0% +varying over space +since i have two pinots + + align:start position:0% +since i have two pinots + + + align:start position:0% +since i have two pinots +so i essentially sample at two point + + align:start position:0% +so i essentially sample at two point + + + align:start position:0% +so i essentially sample at two point +here and there and + + align:start position:0% +here and there and + + + align:start position:0% +here and there and +combine them + + align:start position:0% + + + + align:start position:0% + +so again if these two panels are very + + align:start position:0% +so again if these two panels are very + + + align:start position:0% +so again if these two panels are very +close then these sampling points also + + align:start position:0% +close then these sampling points also + + + align:start position:0% +close then these sampling points also +very close right so the + + align:start position:0% +very close right so the + + + align:start position:0% +very close right so the +the amplitude and phase are more likely + + align:start position:0% +the amplitude and phase are more likely + + + align:start position:0% +the amplitude and phase are more likely +uh similar + + align:start position:0% +uh similar + + + align:start position:0% +uh similar +i mean there is big change right but if + + align:start position:0% +i mean there is big change right but if + + + align:start position:0% +i mean there is big change right but if +if i move this two pin in i mean to + + align:start position:0% +if i move this two pin in i mean to + + + align:start position:0% +if i move this two pin in i mean to +abort and downward so like this + + align:start position:0% +abort and downward so like this + + + align:start position:0% +abort and downward so like this +then the the spacing between two pins + + align:start position:0% +then the the spacing between two pins + + + align:start position:0% +then the the spacing between two pins +are getting bigger and basically i lose + + align:start position:0% +are getting bigger and basically i lose + + + align:start position:0% +are getting bigger and basically i lose +the + + align:start position:0% +the + + + align:start position:0% +the +correlation which means the special + + align:start position:0% +correlation which means the special + + + align:start position:0% +correlation which means the special +coherence is getting attenuated getting + + align:start position:0% +coherence is getting attenuated getting + + + align:start position:0% +coherence is getting attenuated getting +smaller + + align:start position:0% +smaller + + + align:start position:0% +smaller +so + + align:start position:0% +so + + + align:start position:0% +so +again if i plot the intensity at the + + align:start position:0% +again if i plot the intensity at the + + + align:start position:0% +again if i plot the intensity at the +detector with respect to + + align:start position:0% +detector with respect to + + + align:start position:0% +detector with respect to +x2 minus x1 which is the spacing between + + align:start position:0% +x2 minus x1 which is the spacing between + + + align:start position:0% +x2 minus x1 which is the spacing between +two pinholes + + align:start position:0% +two pinholes + + + align:start position:0% +two pinholes +then + + align:start position:0% +then + + + align:start position:0% +then +intensity varying like this + + align:start position:0% +intensity varying like this + + + align:start position:0% +intensity varying like this +right + + align:start position:0% +right + + + align:start position:0% +right +again remember if i have the laser then + + align:start position:0% +again remember if i have the laser then + + + align:start position:0% +again remember if i have the laser then +it doesn't really matter i mean i always + + align:start position:0% +it doesn't really matter i mean i always + + + align:start position:0% +it doesn't really matter i mean i always +get the full contrast right even though + + align:start position:0% +get the full contrast right even though + + + align:start position:0% +get the full contrast right even though +those frequencies of the uh i'm at the + + align:start position:0% +those frequencies of the uh i'm at the + + + align:start position:0% +those frequencies of the uh i'm at the +observation plane the frequency of the + + align:start position:0% +observation plane the frequency of the + + + align:start position:0% +observation plane the frequency of the +interference + + align:start position:0% +interference + + + align:start position:0% +interference +is changing but i always get the full + + align:start position:0% +is changing but i always get the full + + + align:start position:0% +is changing but i always get the full +contrast but contrast getting smaller if + + align:start position:0% +contrast but contrast getting smaller if + + + align:start position:0% +contrast but contrast getting smaller if +you have the in current source + + align:start position:0% + + + + align:start position:0% + +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +let me describe mathematically why this + + align:start position:0% +let me describe mathematically why this + + + align:start position:0% +let me describe mathematically why this +happened + + align:start position:0% +happened + + + align:start position:0% +happened +it doesn't really matter if i i mean + + align:start position:0% +it doesn't really matter if i i mean + + + align:start position:0% +it doesn't really matter if i i mean +whether i used in my cursing + + align:start position:0% +whether i used in my cursing + + + align:start position:0% +whether i used in my cursing +interferement or young + + align:start position:0% +interferement or young + + + align:start position:0% +interferement or young +interferometer basically in the thermal + + align:start position:0% +interferometer basically in the thermal + + + align:start position:0% +interferometer basically in the thermal +we have uh + + align:start position:0% + + + + align:start position:0% + +we have two waves right so a1 e to the + + align:start position:0% +we have two waves right so a1 e to the + + + align:start position:0% +we have two waves right so a1 e to the +pi 1 and a2 e to the pi 2 basically we + + align:start position:0% +pi 1 and a2 e to the pi 2 basically we + + + align:start position:0% +pi 1 and a2 e to the pi 2 basically we +have two wave i can sample in space or + + align:start position:0% +have two wave i can sample in space or + + + align:start position:0% +have two wave i can sample in space or +time domain but anyway i'm going to have + + align:start position:0% +time domain but anyway i'm going to have + + + align:start position:0% +time domain but anyway i'm going to have +two waves and just add them together and + + align:start position:0% +two waves and just add them together and + + + align:start position:0% +two waves and just add them together and +take the magnitude square which is + + align:start position:0% +take the magnitude square which is + + + align:start position:0% +take the magnitude square which is +intensity right + + align:start position:0% +intensity right + + + align:start position:0% +intensity right +so + + align:start position:0% +so + + + align:start position:0% +so +vacation interferometer this is + + align:start position:0% +vacation interferometer this is + + + align:start position:0% +vacation interferometer this is +i mean basically these two waves came + + align:start position:0% +i mean basically these two waves came + + + align:start position:0% +i mean basically these two waves came +from the + + align:start position:0% +from the + + + align:start position:0% +from the +different the uh path length d1 and d2 + + align:start position:0% +different the uh path length d1 and d2 + + + align:start position:0% +different the uh path length d1 and d2 +and young's interferometer basically + + align:start position:0% +and young's interferometer basically + + + align:start position:0% +and young's interferometer basically +they + + align:start position:0% +they + + + align:start position:0% +they +they came from the two different point p + + align:start position:0% +they came from the two different point p + + + align:start position:0% +they came from the two different point p +notes x1 and x2 but anyway i can always + + align:start position:0% +notes x1 and x2 but anyway i can always + + + align:start position:0% +notes x1 and x2 but anyway i can always +write the interference of two waves as + + align:start position:0% +write the interference of two waves as + + + align:start position:0% +write the interference of two waves as +like this so + + align:start position:0% +like this so + + + align:start position:0% +like this so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +wave one and wave two + + align:start position:0% +wave one and wave two + + + align:start position:0% +wave one and wave two +its negative square is gonna be i naught + + align:start position:0% +its negative square is gonna be i naught + + + align:start position:0% +its negative square is gonna be i naught +and one plus m cosine the phase + + align:start position:0% +and one plus m cosine the phase + + + align:start position:0% +and one plus m cosine the phase +difference + + align:start position:0% + + + + align:start position:0% + +yeah we are assuming monochromatic yes + + align:start position:0% +yeah we are assuming monochromatic yes + + + align:start position:0% +yeah we are assuming monochromatic yes +i mean you can write + + align:start position:0% + + + + align:start position:0% + +the one uh we use assuming monochromatic + + align:start position:0% +the one uh we use assuming monochromatic + + + align:start position:0% +the one uh we use assuming monochromatic +because we are using phase notation + + align:start position:0% +because we are using phase notation + + + align:start position:0% +because we are using phase notation +right so + + align:start position:0% +right so + + + align:start position:0% +right so +we write this this and we rewrite phasor + + align:start position:0% +we write this this and we rewrite phasor + + + align:start position:0% +we write this this and we rewrite phasor +but actually there is e to the i omega t + + align:start position:0% +but actually there is e to the i omega t + + + align:start position:0% +but actually there is e to the i omega t +right + + align:start position:0% +right + + + align:start position:0% +right +so + + align:start position:0% +so + + + align:start position:0% +so +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +from we assume it's monochromatic but + + align:start position:0% +from we assume it's monochromatic but + + + align:start position:0% +from we assume it's monochromatic but +even though it's it's normal commander + + align:start position:0% +even though it's it's normal commander + + + align:start position:0% +even though it's it's normal commander +you can always write just addition of + + align:start position:0% +you can always write just addition of + + + align:start position:0% +you can always write just addition of +two apps right + + align:start position:0% +two apps right + + + align:start position:0% +two apps right +it really doesn't matter + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +yeah so interference is basically the d + + align:start position:0% +yeah so interference is basically the d + + + align:start position:0% +yeah so interference is basically the d +system which is i naught so i naught is + + align:start position:0% +system which is i naught so i naught is + + + align:start position:0% +system which is i naught so i naught is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +a1 square plus a2 square which is + + align:start position:0% +a1 square plus a2 square which is + + + align:start position:0% +a1 square plus a2 square which is +intensity of the wave one and intensity + + align:start position:0% +intensity of the wave one and intensity + + + align:start position:0% +intensity of the wave one and intensity +of the wave two so + + align:start position:0% +of the wave two so + + + align:start position:0% +of the wave two so +this this term is just addition of + + align:start position:0% +this this term is just addition of + + + align:start position:0% +this this term is just addition of +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +and we have some + + align:start position:0% +and we have some + + + align:start position:0% +and we have some +cosine modulation term + + align:start position:0% +cosine modulation term + + + align:start position:0% +cosine modulation term +and + + align:start position:0% + + + + align:start position:0% + +so this is basically + + align:start position:0% +so this is basically + + + align:start position:0% +so this is basically +interference so we if you have uh if you + + align:start position:0% +interference so we if you have uh if you + + + align:start position:0% +interference so we if you have uh if you +have a coherent light then + + align:start position:0% +have a coherent light then + + + align:start position:0% +have a coherent light then +we have some d term and have a + + align:start position:0% +we have some d term and have a + + + align:start position:0% +we have some d term and have a +sinusoidal modulation right + + align:start position:0% +sinusoidal modulation right + + + align:start position:0% +sinusoidal modulation right +and it + + align:start position:0% +and it + + + align:start position:0% +and it +had to fit and as the phase very and + + align:start position:0% +had to fit and as the phase very and + + + align:start position:0% +had to fit and as the phase very and +we're going to see the sinusoidal + + align:start position:0% +we're going to see the sinusoidal + + + align:start position:0% +we're going to see the sinusoidal +pattern is changing + + align:start position:0% +pattern is changing + + + align:start position:0% +pattern is changing +but remember that + + align:start position:0% +but remember that + + + align:start position:0% +but remember that +this optical frequency is very fast + + align:start position:0% +this optical frequency is very fast + + + align:start position:0% +this optical frequency is very fast +right + + align:start position:0% +right + + + align:start position:0% +right +the tens of gigahertz are more than that + + align:start position:0% +the tens of gigahertz are more than that + + + align:start position:0% +the tens of gigahertz are more than that +so actually what we measure i mean + + align:start position:0% +so actually what we measure i mean + + + align:start position:0% +so actually what we measure i mean +intensity is time average of this guy so + + align:start position:0% + + + + align:start position:0% + +we're gonna take the time average of + + align:start position:0% +we're gonna take the time average of + + + align:start position:0% +we're gonna take the time average of +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +and + + align:start position:0% +and + + + align:start position:0% +and +if you + + align:start position:0% +if you + + + align:start position:0% +if you +do the math + + align:start position:0% +do the math + + + align:start position:0% +do the math +actually we we have the this term and + + align:start position:0% +actually we we have the this term and + + + align:start position:0% +actually we we have the this term and +this kind of + + align:start position:0% +this kind of + + + align:start position:0% +this kind of +modulation term which is time average of + + align:start position:0% +modulation term which is time average of + + + align:start position:0% +modulation term which is time average of +cosine + + align:start position:0% +cosine + + + align:start position:0% +cosine +with the phase difference but remember + + align:start position:0% +with the phase difference but remember + + + align:start position:0% +with the phase difference but remember +that if we i have increased like this + + align:start position:0% +that if we i have increased like this + + + align:start position:0% +that if we i have increased like this +phase difference is random so + + align:start position:0% +phase difference is random so + + + align:start position:0% +phase difference is random so +what is the average of + + align:start position:0% +what is the average of + + + align:start position:0% +what is the average of +cosine of random phase + + align:start position:0% + + + + align:start position:0% + +exported + + align:start position:0% + + + + align:start position:0% + +what is the average of + + align:start position:0% +what is the average of + + + align:start position:0% +what is the average of +cosine of random phase + + align:start position:0% + + + + align:start position:0% + +zero yeah zero right cosine is + + align:start position:0% +zero yeah zero right cosine is + + + align:start position:0% +zero yeah zero right cosine is +oscillating between one and + + align:start position:0% +oscillating between one and + + + align:start position:0% +oscillating between one and +plus one to minus one so + + align:start position:0% +plus one to minus one so + + + align:start position:0% +plus one to minus one so +if you have random phase and average + + align:start position:0% +if you have random phase and average + + + align:start position:0% +if you have random phase and average +then you get zero right + + align:start position:0% +then you get zero right + + + align:start position:0% +then you get zero right +so if you have equivalent light + + align:start position:0% +so if you have equivalent light + + + align:start position:0% +so if you have equivalent light +and basically intensity is just + + align:start position:0% +and basically intensity is just + + + align:start position:0% +and basically intensity is just +addition of + + align:start position:0% +addition of + + + align:start position:0% +addition of +intensity of two f and we don't have any + + align:start position:0% +intensity of two f and we don't have any + + + align:start position:0% +intensity of two f and we don't have any +interference term + + align:start position:0% +interference term + + + align:start position:0% +interference term +so that's the difference between + + align:start position:0% +so that's the difference between + + + align:start position:0% +so that's the difference between +coherent and incranolite so coherent we + + align:start position:0% +coherent and incranolite so coherent we + + + align:start position:0% +coherent and incranolite so coherent we +always have + + align:start position:0% +always have + + + align:start position:0% +always have +a modulation term i mean it could be + + align:start position:0% +a modulation term i mean it could be + + + align:start position:0% +a modulation term i mean it could be +zero it depending on phase difference + + align:start position:0% +zero it depending on phase difference + + + align:start position:0% +zero it depending on phase difference +right but + + align:start position:0% +right but + + + align:start position:0% +right but +in corona you always have just addition + + align:start position:0% +in corona you always have just addition + + + align:start position:0% +in corona you always have just addition +of this term i mean addition of + + align:start position:0% +of this term i mean addition of + + + align:start position:0% +of this term i mean addition of +intensity + + align:start position:0% + + + + align:start position:0% + +yeah so if it's perfectly in current + + align:start position:0% +yeah so if it's perfectly in current + + + align:start position:0% +yeah so if it's perfectly in current +then we have just addition of intensity + + align:start position:0% +then we have just addition of intensity + + + align:start position:0% +then we have just addition of intensity +and actually + + align:start position:0% +and actually + + + align:start position:0% +and actually +coherent and encoding is very actually + + align:start position:0% +coherent and encoding is very actually + + + align:start position:0% +coherent and encoding is very actually +true + + align:start position:0% +true + + + align:start position:0% +true +opposite extreme case right + + align:start position:0% +opposite extreme case right + + + align:start position:0% +opposite extreme case right +so i mean it's just like monochromatic + + align:start position:0% +so i mean it's just like monochromatic + + + align:start position:0% +so i mean it's just like monochromatic +we are not gonna i mean in real case we + + align:start position:0% +we are not gonna i mean in real case we + + + align:start position:0% +we are not gonna i mean in real case we +are not gonna have really uh + + align:start position:0% +are not gonna have really uh + + + align:start position:0% +are not gonna have really uh +monochromatic source our source is + + align:start position:0% +monochromatic source our source is + + + align:start position:0% +monochromatic source our source is +always finite bandwidth right it's not + + align:start position:0% +always finite bandwidth right it's not + + + align:start position:0% +always finite bandwidth right it's not +gonna be delta function so it's same + + align:start position:0% +gonna be delta function so it's same + + + align:start position:0% +gonna be delta function so it's same +thing we are not gonna have + + align:start position:0% +thing we are not gonna have + + + align:start position:0% +thing we are not gonna have +the perfectly coherent or perfectly in + + align:start position:0% +the perfectly coherent or perfectly in + + + align:start position:0% +the perfectly coherent or perfectly in +queen everything is a partially coherent + + align:start position:0% +queen everything is a partially coherent + + + align:start position:0% +queen everything is a partially coherent +so you if you want to deal with that and + + align:start position:0% +so you if you want to deal with that and + + + align:start position:0% +so you if you want to deal with that and +you have to apply + + align:start position:0% +you have to apply + + + align:start position:0% +you have to apply +basically statistics + + align:start position:0% +basically statistics + + + align:start position:0% +basically statistics +all to all these uh fresnel and frontal + + align:start position:0% +all to all these uh fresnel and frontal + + + align:start position:0% +all to all these uh fresnel and frontal +flow + + align:start position:0% +flow + + + align:start position:0% +flow +i mean this kind of free optics so + + align:start position:0% +i mean this kind of free optics so + + + align:start position:0% +i mean this kind of free optics so +it's called the statistical optics and + + align:start position:0% +it's called the statistical optics and + + + align:start position:0% +it's called the statistical optics and +it's covered in + + align:start position:0% +it's covered in + + + align:start position:0% +it's covered in +2.717 so if you want to + + align:start position:0% +2.717 so if you want to + + + align:start position:0% +2.717 so if you want to +learn more more about it then you can + + align:start position:0% +learn more more about it then you can + + + align:start position:0% +learn more more about it then you can +take + + align:start position:0% +take + + + align:start position:0% +take +2717. + + align:start position:0% +2717. + + + align:start position:0% +2717. +nevertheless the korean and in current + + align:start position:0% +nevertheless the korean and in current + + + align:start position:0% +nevertheless the korean and in current +case is enough they are enough to + + align:start position:0% +case is enough they are enough to + + + align:start position:0% +case is enough they are enough to +describe uh many many uh phenomena so + + align:start position:0% +describe uh many many uh phenomena so + + + align:start position:0% +describe uh many many uh phenomena so +we are focused on coherent and + + align:start position:0% +we are focused on coherent and + + + align:start position:0% +we are focused on coherent and +increasing uh equal and current uh state + + align:start position:0% +increasing uh equal and current uh state + + + align:start position:0% +increasing uh equal and current uh state +actually + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +really fast + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +oops sorry + + align:start position:0% + + + + align:start position:0% + +so since we have two kind of coherence + + align:start position:0% +so since we have two kind of coherence + + + align:start position:0% +so since we have two kind of coherence +so temporal coherence and special + + align:start position:0% +so temporal coherence and special + + + align:start position:0% +so temporal coherence and special +coherence + + align:start position:0% +coherence + + + align:start position:0% +coherence +so + + align:start position:0% +so + + + align:start position:0% +so +actually we have four different + + align:start position:0% +actually we have four different + + + align:start position:0% +actually we have four different +combinations right so temporally + + align:start position:0% +combinations right so temporally + + + align:start position:0% +combinations right so temporally +especially korean and + + align:start position:0% +especially korean and + + + align:start position:0% +especially korean and +temporary especially in korean and + + align:start position:0% +temporary especially in korean and + + + align:start position:0% +temporary especially in korean and +you know + + align:start position:0% +you know + + + align:start position:0% +you know +temporarily korean especially korean + + align:start position:0% +temporarily korean especially korean + + + align:start position:0% +temporarily korean especially korean +temporary coherence especially in queen + + align:start position:0% +temporary coherence especially in queen + + + align:start position:0% +temporary coherence especially in queen +so + + align:start position:0% +so + + + align:start position:0% +so +the rule of thumb + + align:start position:0% +the rule of thumb + + + align:start position:0% +the rule of thumb +so temporal coherence is related to the + + align:start position:0% +so temporal coherence is related to the + + + align:start position:0% +so temporal coherence is related to the +bandwidth of the + + align:start position:0% +bandwidth of the + + + align:start position:0% +bandwidth of the +your source and basically the color of + + align:start position:0% +your source and basically the color of + + + align:start position:0% +your source and basically the color of +your source so if you have one color in + + align:start position:0% +your source so if you have one color in + + + align:start position:0% +your source so if you have one color in +monochromatic then it's + + align:start position:0% +monochromatic then it's + + + align:start position:0% +monochromatic then it's +question yeah + + align:start position:0% +question yeah + + + align:start position:0% +question yeah +where do diode lasers go in that chart + + align:start position:0% + + + + align:start position:0% + +diode laser is more like + + align:start position:0% +diode laser is more like + + + align:start position:0% +diode laser is more like +temporary and special equivalent + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so oh yeah let me just continue so + + align:start position:0% +so oh yeah let me just continue so + + + align:start position:0% +so oh yeah let me just continue so +temporal aquarius is related to color so + + align:start position:0% +temporal aquarius is related to color so + + + align:start position:0% +temporal aquarius is related to color so +if you have laser like single color + + align:start position:0% +if you have laser like single color + + + align:start position:0% +if you have laser like single color +monochromatic then it's more like + + align:start position:0% +monochromatic then it's more like + + + align:start position:0% +monochromatic then it's more like +coherent but if you have white light + + align:start position:0% +coherent but if you have white light + + + align:start position:0% +coherent but if you have white light +like this fluorescent lamp or halogen + + align:start position:0% +like this fluorescent lamp or halogen + + + align:start position:0% +like this fluorescent lamp or halogen +lamp then you know it's broadband so + + align:start position:0% +lamp then you know it's broadband so + + + align:start position:0% +lamp then you know it's broadband so +it's temporarily increasing + + align:start position:0% +it's temporarily increasing + + + align:start position:0% +it's temporarily increasing +and special occurrence is related to + + align:start position:0% +and special occurrence is related to + + + align:start position:0% +and special occurrence is related to +actually the size of the source and the + + align:start position:0% +actually the size of the source and the + + + align:start position:0% +actually the size of the source and the +distance + + align:start position:0% +distance + + + align:start position:0% +distance +so everything coming from the points of + + align:start position:0% +so everything coming from the points of + + + align:start position:0% +so everything coming from the points of +especially especially cohen because you + + align:start position:0% +especially especially cohen because you + + + align:start position:0% +especially especially cohen because you +know they are basically coming from the + + align:start position:0% +know they are basically coming from the + + + align:start position:0% +know they are basically coming from the +same point + + align:start position:0% +same point + + + align:start position:0% +same point +but if your source is extended like + + align:start position:0% +but if your source is extended like + + + align:start position:0% +but if your source is extended like +or you know you have a filament in the + + align:start position:0% +or you know you have a filament in the + + + align:start position:0% +or you know you have a filament in the +bulb or + + align:start position:0% +bulb or + + + align:start position:0% +bulb or +this kind of fluorescent light then + + align:start position:0% +this kind of fluorescent light then + + + align:start position:0% +this kind of fluorescent light then +especially in korean + + align:start position:0% +especially in korean + + + align:start position:0% +especially in korean +so + + align:start position:0% +so + + + align:start position:0% +so +the monochromatic laser source you know + + align:start position:0% +the monochromatic laser source you know + + + align:start position:0% +the monochromatic laser source you know +laser is very + + align:start position:0% +laser is very + + + align:start position:0% +laser is very +monochromatic and it's the uh the output + + align:start position:0% +monochromatic and it's the uh the output + + + align:start position:0% +monochromatic and it's the uh the output +is very small so + + align:start position:0% +is very small so + + + align:start position:0% +is very small so +laser is typically very temporary and + + align:start position:0% +laser is typically very temporary and + + + align:start position:0% +laser is typically very temporary and +especially in korean and that's why + + align:start position:0% +especially in korean and that's why + + + align:start position:0% +especially in korean and that's why +people use it in interferometry + + align:start position:0% +people use it in interferometry + + + align:start position:0% +people use it in interferometry +and + + align:start position:0% +and + + + align:start position:0% +and +white light source and if you + + align:start position:0% +white light source and if you + + + align:start position:0% +white light source and if you +if you are nearby the wide wildlife + + align:start position:0% +if you are nearby the wide wildlife + + + align:start position:0% +if you are nearby the wide wildlife +source then it's more like temporary and + + align:start position:0% +source then it's more like temporary and + + + align:start position:0% +source then it's more like temporary and +in temporary and especially in korean + + align:start position:0% +in temporary and especially in korean + + + align:start position:0% +in temporary and especially in korean +and actually these two are a little bit + + align:start position:0% +and actually these two are a little bit + + + align:start position:0% +and actually these two are a little bit +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +so temporarily in korean but especially + + align:start position:0% +so temporarily in korean but especially + + + align:start position:0% +so temporarily in korean but especially +kohen + + align:start position:0% +kohen + + + align:start position:0% +kohen +so if you put a pinhole small pinhole in + + align:start position:0% +so if you put a pinhole small pinhole in + + + align:start position:0% +so if you put a pinhole small pinhole in +in front of the white light then it's + + align:start position:0% +in front of the white light then it's + + + align:start position:0% +in front of the white light then it's +temporarily in korean because it's + + align:start position:0% +temporarily in korean because it's + + + align:start position:0% +temporarily in korean because it's +broadband but it's coming from pinhole + + align:start position:0% +broadband but it's coming from pinhole + + + align:start position:0% +broadband but it's coming from pinhole +so especially korean + + align:start position:0% +so especially korean + + + align:start position:0% +so especially korean +at the same reason the sunlight is very + + align:start position:0% +at the same reason the sunlight is very + + + align:start position:0% +at the same reason the sunlight is very +especially + + align:start position:0% +especially + + + align:start position:0% +especially +coherent but temporarily in korean but + + align:start position:0% +coherent but temporarily in korean but + + + align:start position:0% +coherent but temporarily in korean but +sun is very huge but also the distance + + align:start position:0% +sun is very huge but also the distance + + + align:start position:0% +sun is very huge but also the distance +very huge right so if you see the sun + + align:start position:0% +very huge right so if you see the sun + + + align:start position:0% +very huge right so if you see the sun +then it looks you know it's sunlight + + align:start position:0% +then it looks you know it's sunlight + + + align:start position:0% +then it looks you know it's sunlight +it's coming from point source right so + + align:start position:0% +it's coming from point source right so + + + align:start position:0% +it's coming from point source right so +that's why + + align:start position:0% +that's why + + + align:start position:0% +that's why +especially korean + + align:start position:0% +especially korean + + + align:start position:0% +especially korean +and + + align:start position:0% +and + + + align:start position:0% +and +yeah the live from + + align:start position:0% +yeah the live from + + + align:start position:0% +yeah the live from +press the button + + align:start position:0% + + + + align:start position:0% + +doesn't work yeah oh yeah + + align:start position:0% +doesn't work yeah oh yeah + + + align:start position:0% +doesn't work yeah oh yeah +so anyway so one of the terms i heard + + align:start position:0% +so anyway so one of the terms i heard + + + align:start position:0% +so anyway so one of the terms i heard +come off this computer flights which i + + align:start position:0% +come off this computer flights which i + + + align:start position:0% +come off this computer flights which i +guess really is abandonment + + align:start position:0% +guess really is abandonment + + + align:start position:0% +guess really is abandonment +to measure clearance but what + + align:start position:0% +to measure clearance but what + + + align:start position:0% +to measure clearance but what +exactly is + + align:start position:0% +exactly is + + + align:start position:0% +exactly is +overhearing those so here in points uh + + align:start position:0% +overhearing those so here in points uh + + + align:start position:0% +overhearing those so here in points uh +describing + + align:start position:0% + + + + align:start position:0% + +um yeah that's an exclusion + + align:start position:0% + + + + align:start position:0% + +so actually + + align:start position:0% +so actually + + + align:start position:0% +so actually +uh it's it's a little bit + + align:start position:0% +uh it's it's a little bit + + + align:start position:0% +uh it's it's a little bit +lengthy to explain but what essentially + + align:start position:0% +lengthy to explain but what essentially + + + align:start position:0% +lengthy to explain but what essentially +the light i mean this kind of light is + + align:start position:0% +the light i mean this kind of light is + + + align:start position:0% +the light i mean this kind of light is +you know you excite some atom and when + + align:start position:0% +you know you excite some atom and when + + + align:start position:0% +you know you excite some atom and when +they are going down you get the energy + + align:start position:0% +they are going down you get the energy + + + align:start position:0% +they are going down you get the energy +right i mean + + align:start position:0% +right i mean + + + align:start position:0% +right i mean +basically light energy by + + align:start position:0% +basically light energy by + + + align:start position:0% +basically light energy by +e e to the i mean the energy is h new + + align:start position:0% +e e to the i mean the energy is h new + + + align:start position:0% +e e to the i mean the energy is h new +right + + align:start position:0% +right + + + align:start position:0% +right +so + + align:start position:0% + + + + align:start position:0% + +but it's not i mean this kind of + + align:start position:0% +but it's not i mean this kind of + + + align:start position:0% +but it's not i mean this kind of +spontaneous emission it's not correlated + + align:start position:0% +spontaneous emission it's not correlated + + + align:start position:0% +spontaneous emission it's not correlated +you have many many items but they are + + align:start position:0% +you have many many items but they are + + + align:start position:0% +you have many many items but they are +not + + align:start position:0% +not + + + align:start position:0% +not +synchronized right it's they're very + + align:start position:0% +synchronized right it's they're very + + + align:start position:0% +synchronized right it's they're very +emitting randomly + + align:start position:0% +emitting randomly + + + align:start position:0% +emitting randomly +so you basically you have some finite + + align:start position:0% + + + + align:start position:0% + +a wave train so in that a wave trend you + + align:start position:0% +a wave train so in that a wave trend you + + + align:start position:0% +a wave train so in that a wave trend you +get + + align:start position:0% +get + + + align:start position:0% +get +basically coherently but you have many + + align:start position:0% +basically coherently but you have many + + + align:start position:0% +basically coherently but you have many +many of them + + align:start position:0% +many of them + + + align:start position:0% +many of them +with the random phase that's why you add + + align:start position:0% +with the random phase that's why you add + + + align:start position:0% +with the random phase that's why you add +them together then you get in current so + + align:start position:0% +them together then you get in current so + + + align:start position:0% +them together then you get in current so +coherence length is essentially what is + + align:start position:0% +coherence length is essentially what is + + + align:start position:0% +coherence length is essentially what is +the length of the a finite wave train + + align:start position:0% +the length of the a finite wave train + + + align:start position:0% +the length of the a finite wave train +that you can define uh deterministic + + align:start position:0% +that you can define uh deterministic + + + align:start position:0% +that you can define uh deterministic +phase + + align:start position:0% +phase + + + align:start position:0% +phase +so + + align:start position:0% +so + + + align:start position:0% +so +d1 so in the just imagine the + + align:start position:0% +d1 so in the just imagine the + + + align:start position:0% +d1 so in the just imagine the +microscience theorem if you have you + + align:start position:0% +microscience theorem if you have you + + + align:start position:0% +microscience theorem if you have you +have the + + align:start position:0% +have the + + + align:start position:0% +have the +optic capacity first d1 minus t2 but + + align:start position:0% +optic capacity first d1 minus t2 but + + + align:start position:0% +optic capacity first d1 minus t2 but +that difference is within the uh that + + align:start position:0% +that difference is within the uh that + + + align:start position:0% +that difference is within the uh that +the distance then you get + + align:start position:0% +the distance then you get + + + align:start position:0% +the distance then you get +interference right that's why we call + + align:start position:0% +interference right that's why we call + + + align:start position:0% +interference right that's why we call +the coherence length and coordinates + + align:start position:0% +the coherence length and coordinates + + + align:start position:0% +the coherence length and coordinates +time + + align:start position:0% +time + + + align:start position:0% +time +and + + align:start position:0% + + + + align:start position:0% + +yeah essentially that's it + + align:start position:0% +yeah essentially that's it + + + align:start position:0% +yeah essentially that's it +so + + align:start position:0% +so + + + align:start position:0% +so +remember that if we have the + + align:start position:0% + + + + align:start position:0% + +uh excuse me yep + + align:start position:0% +uh excuse me yep + + + align:start position:0% +uh excuse me yep +uh here i also have one question so i + + align:start position:0% +uh here i also have one question so i + + + align:start position:0% +uh here i also have one question so i +want to check whether this understanding + + align:start position:0% +want to check whether this understanding + + + align:start position:0% +want to check whether this understanding +is correct so let's see if the light + + align:start position:0% +is correct so let's see if the light + + + align:start position:0% +is correct so let's see if the light +come at the perfect parallel direction + + align:start position:0% +come at the perfect parallel direction + + + align:start position:0% +come at the perfect parallel direction +even though they have different + + align:start position:0% +even though they have different + + + align:start position:0% +even though they have different +wavelengths it's considered as + + align:start position:0% +wavelengths it's considered as + + + align:start position:0% +wavelengths it's considered as +especially coherent + + align:start position:0% +especially coherent + + + align:start position:0% +especially coherent +and + + align:start position:0% +and + + + align:start position:0% +and +even if life go into different direction + + align:start position:0% +even if life go into different direction + + + align:start position:0% +even if life go into different direction +but if they have perfect the single + + align:start position:0% +but if they have perfect the single + + + align:start position:0% +but if they have perfect the single +wavelengths they consider as a + + align:start position:0% +wavelengths they consider as a + + + align:start position:0% +wavelengths they consider as a +time coherent it is understanding + + align:start position:0% +time coherent it is understanding + + + align:start position:0% +time coherent it is understanding +correct + + align:start position:0% +correct + + + align:start position:0% +correct +so actually if you have plane wave then + + align:start position:0% +so actually if you have plane wave then + + + align:start position:0% +so actually if you have plane wave then +you + + align:start position:0% +you + + + align:start position:0% +you +already assume your wave is specially + + align:start position:0% +already assume your wave is specially + + + align:start position:0% +already assume your wave is specially +coherent + + align:start position:0% +coherent + + + align:start position:0% +coherent +because plainly + + align:start position:0% +because plainly + + + align:start position:0% +because plainly +it doesn't really matter where you + + align:start position:0% +it doesn't really matter where you + + + align:start position:0% +it doesn't really matter where you +sample right they have always in phase + + align:start position:0% +sample right they have always in phase + + + align:start position:0% +sample right they have always in phase +right so + + align:start position:0% +right so + + + align:start position:0% +right so +your assumption is especially coherent + + align:start position:0% +your assumption is especially coherent + + + align:start position:0% +your assumption is especially coherent +if you assume especially in a special + + align:start position:0% +if you assume especially in a special + + + align:start position:0% +if you assume especially in a special +coherent life + + align:start position:0% +coherent life + + + align:start position:0% +coherent life +and you mean even if they have different + + align:start position:0% +and you mean even if they have different + + + align:start position:0% +and you mean even if they have different +wavelengths + + align:start position:0% +wavelengths + + + align:start position:0% +wavelengths +yes + + align:start position:0% +yes + + + align:start position:0% +yes +yeah even yeah even though you have + + align:start position:0% +yeah even yeah even though you have + + + align:start position:0% +yeah even yeah even though you have +different wavelengths that's temporary + + align:start position:0% +different wavelengths that's temporary + + + align:start position:0% +different wavelengths that's temporary +in current but in space domain you have + + align:start position:0% +in current but in space domain you have + + + align:start position:0% +in current but in space domain you have +specially coherent + + align:start position:0% +specially coherent + + + align:start position:0% +specially coherent +yeah another way to think of especially + + align:start position:0% +yeah another way to think of especially + + + align:start position:0% +yeah another way to think of especially +in korean is you have many many plane + + align:start position:0% +in korean is you have many many plane + + + align:start position:0% +in korean is you have many many plane +waves + + align:start position:0% +waves + + + align:start position:0% +waves +and propagating all the different + + align:start position:0% +and propagating all the different + + + align:start position:0% +and propagating all the different +directions + + align:start position:0% +directions + + + align:start position:0% +directions +but they are randomly + + align:start position:0% +but they are randomly + + + align:start position:0% +but they are randomly +they have random initial interface + + align:start position:0% +they have random initial interface + + + align:start position:0% +they have random initial interface +so you know + + align:start position:0% +so you know + + + align:start position:0% +so you know +basically especially in coin light you + + align:start position:0% +basically especially in coin light you + + + align:start position:0% +basically especially in coin light you +cannot really define unique uh + + align:start position:0% +cannot really define unique uh + + + align:start position:0% +cannot really define unique uh +propagation direction + + align:start position:0% +propagation direction + + + align:start position:0% +propagation direction +yeah but + + align:start position:0% +yeah but + + + align:start position:0% +yeah but +especially coherent light you can always + + align:start position:0% +especially coherent light you can always + + + align:start position:0% +especially coherent light you can always +define direction i mean even though + + align:start position:0% +define direction i mean even though + + + align:start position:0% +define direction i mean even though +wave it has all the direction but you + + align:start position:0% +wave it has all the direction but you + + + align:start position:0% +wave it has all the direction but you +can always say + + align:start position:0% +can always say + + + align:start position:0% +can always say +if you put if you define the position + + align:start position:0% +if you put if you define the position + + + align:start position:0% +if you put if you define the position +then that position you have a k vector + + align:start position:0% +then that position you have a k vector + + + align:start position:0% +then that position you have a k vector +right so + + align:start position:0% +right so + + + align:start position:0% +right so +you can define the direction + + align:start position:0% + + + + align:start position:0% + +yeah so let me yeah so let me just + + align:start position:0% +yeah so let me yeah so let me just + + + align:start position:0% +yeah so let me yeah so let me just +finish this + + align:start position:0% +finish this + + + align:start position:0% +finish this +thing so if if d1 and d2 are within the + + align:start position:0% +thing so if if d1 and d2 are within the + + + align:start position:0% +thing so if if d1 and d2 are within the +coherence length or current time then + + align:start position:0% +coherence length or current time then + + + align:start position:0% +coherence length or current time then +you get some + + align:start position:0% +you get some + + + align:start position:0% +you get some +interference but after that so basically + + align:start position:0% +interference but after that so basically + + + align:start position:0% +interference but after that so basically +this is essentially the coherence length + + align:start position:0% +this is essentially the coherence length + + + align:start position:0% +this is essentially the coherence length +of this particular source + + align:start position:0% +of this particular source + + + align:start position:0% +of this particular source +and remember that + + align:start position:0% +and remember that + + + align:start position:0% +and remember that +i mean this always happens so even + + align:start position:0% +i mean this always happens so even + + + align:start position:0% +i mean this always happens so even +though you have a white light you you + + align:start position:0% +though you have a white light you you + + + align:start position:0% +though you have a white light you you +can get interference but + + align:start position:0% +can get interference but + + + align:start position:0% +can get interference but +with within a very limited range okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +how where did i stop + + align:start position:0% + + + + align:start position:0% + +okay yeah and + + align:start position:0% +okay yeah and + + + align:start position:0% +okay yeah and +another + + align:start position:0% +another + + + align:start position:0% +another +excuse me so another interesting is + + align:start position:0% +excuse me so another interesting is + + + align:start position:0% +excuse me so another interesting is +there is a laser + + align:start position:0% +there is a laser + + + align:start position:0% +there is a laser +that has a broadband which is per + + align:start position:0% +that has a broadband which is per + + + align:start position:0% +that has a broadband which is per +continuum laser + + align:start position:0% +continuum laser + + + align:start position:0% +continuum laser +so especially coherent but + + align:start position:0% +so especially coherent but + + + align:start position:0% +so especially coherent but +it's broadband so you have temporary + + align:start position:0% +it's broadband so you have temporary + + + align:start position:0% +it's broadband so you have temporary +inquiry + + align:start position:0% + + + + align:start position:0% + +and the other kind of + + align:start position:0% +and the other kind of + + + align:start position:0% +and the other kind of +this combination is temporary coherent + + align:start position:0% +this combination is temporary coherent + + + align:start position:0% +this combination is temporary coherent +but especially in korean + + align:start position:0% +but especially in korean + + + align:start position:0% +but especially in korean +so it's typically + + align:start position:0% + + + + align:start position:0% + +referred to quasim monochromatic + + align:start position:0% +referred to quasim monochromatic + + + align:start position:0% +referred to quasim monochromatic +temporary cohere + + align:start position:0% +temporary cohere + + + align:start position:0% +temporary cohere +and especially in korean + + align:start position:0% +and especially in korean + + + align:start position:0% +and especially in korean +so if you put a rotating diffuser which + + align:start position:0% +so if you put a rotating diffuser which + + + align:start position:0% +so if you put a rotating diffuser which +is + + align:start position:0% +is + + + align:start position:0% +is +mean you rotate the uh + + align:start position:0% +mean you rotate the uh + + + align:start position:0% +mean you rotate the uh +ground glass or like milky glass in + + align:start position:0% +ground glass or like milky glass in + + + align:start position:0% +ground glass or like milky glass in +front of the razor in front of the laser + + align:start position:0% +front of the razor in front of the laser + + + align:start position:0% +front of the razor in front of the laser +then basically + + align:start position:0% +then basically + + + align:start position:0% +then basically +it induces some random phase to the + + align:start position:0% +it induces some random phase to the + + + align:start position:0% +it induces some random phase to the +laser beam or you can say it destroy the + + align:start position:0% +laser beam or you can say it destroy the + + + align:start position:0% +laser beam or you can say it destroy the +correlation of the laser beam so it's + + align:start position:0% +correlation of the laser beam so it's + + + align:start position:0% +correlation of the laser beam so it's +monochromatic so temporary coherent but + + align:start position:0% +monochromatic so temporary coherent but + + + align:start position:0% +monochromatic so temporary coherent but +in space domain it has a random phase so + + align:start position:0% +in space domain it has a random phase so + + + align:start position:0% +in space domain it has a random phase so +you get you can have the uh especially + + align:start position:0% +you get you can have the uh especially + + + align:start position:0% +you get you can have the uh especially +in current life + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so these are lists of optical instrument + + align:start position:0% +so these are lists of optical instrument + + + align:start position:0% +so these are lists of optical instrument +uh using special coherence on imaging + + align:start position:0% +uh using special coherence on imaging + + + align:start position:0% +uh using special coherence on imaging +microsoft and stellar interferometer and + + align:start position:0% +microsoft and stellar interferometer and + + + align:start position:0% +microsoft and stellar interferometer and +the radio telescope they are basically + + align:start position:0% +the radio telescope they are basically + + + align:start position:0% +the radio telescope they are basically +uh measuring special coherence + + align:start position:0% +uh measuring special coherence + + + align:start position:0% +uh measuring special coherence +of the light coming from a distant star + + align:start position:0% +of the light coming from a distant star + + + align:start position:0% +of the light coming from a distant star +or sun or yeah they're basically for + + align:start position:0% +or sun or yeah they're basically for + + + align:start position:0% +or sun or yeah they're basically for +externally so they can measure + + align:start position:0% +externally so they can measure + + + align:start position:0% +externally so they can measure +for example diameter of a distant star + + align:start position:0% +for example diameter of a distant star + + + align:start position:0% +for example diameter of a distant star +you remember the spatial coherence is + + align:start position:0% +you remember the spatial coherence is + + + align:start position:0% +you remember the spatial coherence is +related to the source size and the + + align:start position:0% +related to the source size and the + + + align:start position:0% +related to the source size and the +distance so if you properly measure + + align:start position:0% +distance so if you properly measure + + + align:start position:0% +distance so if you properly measure +special coherence actually the envelope + + align:start position:0% +special coherence actually the envelope + + + align:start position:0% +special coherence actually the envelope +of the special coherence then you can + + align:start position:0% +of the special coherence then you can + + + align:start position:0% +of the special coherence then you can +estimate the diameter of the star + + align:start position:0% + + + + align:start position:0% + +yeah i believe microsoft are normal + + align:start position:0% +yeah i believe microsoft are normal + + + align:start position:0% +yeah i believe microsoft are normal +price for this + + align:start position:0% + + + + align:start position:0% + +and optical current tomography is + + align:start position:0% +and optical current tomography is + + + align:start position:0% +and optical current tomography is +actually uh utilizing temporal + + align:start position:0% +actually uh utilizing temporal + + + align:start position:0% +actually uh utilizing temporal +incurrence so as i just described if you + + align:start position:0% +incurrence so as i just described if you + + + align:start position:0% +incurrence so as i just described if you +even though you have y light + + align:start position:0% +even though you have y light + + + align:start position:0% +even though you have y light +if you are properly matched optical path + + align:start position:0% +if you are properly matched optical path + + + align:start position:0% +if you are properly matched optical path +difference then you can get interference + + align:start position:0% +difference then you can get interference + + + align:start position:0% +difference then you can get interference +within the very + + align:start position:0% +within the very + + + align:start position:0% +within the very +small range + + align:start position:0% +small range + + + align:start position:0% +small range +so let's say you have multiple layer + + align:start position:0% +so let's say you have multiple layer + + + align:start position:0% +so let's say you have multiple layer +like tissue and you construct a + + align:start position:0% +like tissue and you construct a + + + align:start position:0% +like tissue and you construct a +microscope interferometer with the white + + align:start position:0% +microscope interferometer with the white + + + align:start position:0% +microscope interferometer with the white +light and as you move the other mirror + + align:start position:0% +light and as you move the other mirror + + + align:start position:0% +light and as you move the other mirror +then if the optical pacifiers match then + + align:start position:0% +then if the optical pacifiers match then + + + align:start position:0% +then if the optical pacifiers match then +you get interference but if you slightly + + align:start position:0% +you get interference but if you slightly + + + align:start position:0% +you get interference but if you slightly +off that point then you don't get the + + align:start position:0% +off that point then you don't get the + + + align:start position:0% +off that point then you don't get the +interference right so if you plot the + + align:start position:0% +interference right so if you plot the + + + align:start position:0% +interference right so if you plot the +interference versus the distance of the + + align:start position:0% +interference versus the distance of the + + + align:start position:0% +interference versus the distance of the +mirror then you can + + align:start position:0% +mirror then you can + + + align:start position:0% +mirror then you can +see kind of the peak whenever you have + + align:start position:0% +see kind of the peak whenever you have + + + align:start position:0% +see kind of the peak whenever you have +the + + align:start position:0% +the + + + align:start position:0% +the +right position + + align:start position:0% +right position + + + align:start position:0% +right position +i mean whenever you have the right + + align:start position:0% +i mean whenever you have the right + + + align:start position:0% +i mean whenever you have the right +position to the t to each layer right so + + align:start position:0% +position to the t to each layer right so + + + align:start position:0% +position to the t to each layer right so +you can kind of do the optical + + align:start position:0% +you can kind of do the optical + + + align:start position:0% +you can kind of do the optical +sectioning + + align:start position:0% + + + + align:start position:0% + +and in + + align:start position:0% +and in + + + align:start position:0% +and in +the lithography like verification + + align:start position:0% +the lithography like verification + + + align:start position:0% +the lithography like verification +technique people + + align:start position:0% +technique people + + + align:start position:0% +technique people +use + + align:start position:0% +use + + + align:start position:0% +use +some special coils to + + align:start position:0% + + + + align:start position:0% + +make basically make some uh + + align:start position:0% +make basically make some uh + + + align:start position:0% +make basically make some uh +it's a nice pattern + + align:start position:0% +it's a nice pattern + + + align:start position:0% +it's a nice pattern +because as we describe special currency + + align:start position:0% +because as we describe special currency + + + align:start position:0% +because as we describe special currency +is essentially + + align:start position:0% +is essentially + + + align:start position:0% +is essentially +affecting uh basically resolution and + + align:start position:0% +affecting uh basically resolution and + + + align:start position:0% +affecting uh basically resolution and +the the contrast of your image so + + align:start position:0% +the the contrast of your image so + + + align:start position:0% +the the contrast of your image so +yeah there are these kind of things + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +yeah even though we deal with the + + align:start position:0% +yeah even though we deal with the + + + align:start position:0% +yeah even though we deal with the +especially coherent with the wave system + + align:start position:0% +especially coherent with the wave system + + + align:start position:0% +especially coherent with the wave system +so what if we change the elimination + + align:start position:0% +so what if we change the elimination + + + align:start position:0% +so what if we change the elimination +with to + + align:start position:0% +with to + + + align:start position:0% +with to +especially in korean or + + align:start position:0% +especially in korean or + + + align:start position:0% +especially in korean or +temporary current + + align:start position:0% +temporary current + + + align:start position:0% +temporary current +and + + align:start position:0% +and + + + align:start position:0% +and +you know obviously my image will be + + align:start position:0% +you know obviously my image will be + + + align:start position:0% +you know obviously my image will be +different the way depending on the spec + + align:start position:0% +different the way depending on the spec + + + align:start position:0% +different the way depending on the spec +depending on the coherent state actually + + align:start position:0% +depending on the coherent state actually + + + align:start position:0% +depending on the coherent state actually +that's the bottom line of the uh today's + + align:start position:0% +that's the bottom line of the uh today's + + + align:start position:0% +that's the bottom line of the uh today's +course today's lecture + + align:start position:0% +course today's lecture + + + align:start position:0% +course today's lecture +so + + align:start position:0% +so + + + align:start position:0% +so +so the first if we have the temporary + + align:start position:0% +so the first if we have the temporary + + + align:start position:0% +so the first if we have the temporary +current basically we if you have the + + align:start position:0% +current basically we if you have the + + + align:start position:0% +current basically we if you have the +broadband or many many colors + + align:start position:0% +broadband or many many colors + + + align:start position:0% +broadband or many many colors +then + + align:start position:0% +then + + + align:start position:0% +then +the chromatic aberration is typical + + align:start position:0% +the chromatic aberration is typical + + + align:start position:0% +the chromatic aberration is typical +evidence that i have uh + + align:start position:0% +evidence that i have uh + + + align:start position:0% +evidence that i have uh +temporarily in current source + + align:start position:0% +temporarily in current source + + + align:start position:0% +temporarily in current source +and how to delete how to deal with it if + + align:start position:0% +and how to delete how to deal with it if + + + align:start position:0% +and how to delete how to deal with it if +you have many many colors + + align:start position:0% +you have many many colors + + + align:start position:0% +you have many many colors +it's pretty straightforward right so you + + align:start position:0% +it's pretty straightforward right so you + + + align:start position:0% +it's pretty straightforward right so you +can define point step function or atf or + + align:start position:0% +can define point step function or atf or + + + align:start position:0% +can define point step function or atf or +out or + + align:start position:0% +out or + + + align:start position:0% +out or +whatever it is you can define that thing + + align:start position:0% +whatever it is you can define that thing + + + align:start position:0% +whatever it is you can define that thing +for each wavelength so for example if i + + align:start position:0% +for each wavelength so for example if i + + + align:start position:0% +for each wavelength so for example if i +can define point sphere function for red + + align:start position:0% +can define point sphere function for red + + + align:start position:0% +can define point sphere function for red +wavelengths i can define points function + + align:start position:0% +wavelengths i can define points function + + + align:start position:0% +wavelengths i can define points function +for blue wavelengths so it's just you + + align:start position:0% +for blue wavelengths so it's just you + + + align:start position:0% +for blue wavelengths so it's just you +can do the straightforward fashion + + align:start position:0% +can do the straightforward fashion + + + align:start position:0% +can do the straightforward fashion +and special coherence is a little bit + + align:start position:0% +and special coherence is a little bit + + + align:start position:0% +and special coherence is a little bit +uh + + align:start position:0% +uh + + + align:start position:0% +uh +i mean you need to be careful + + align:start position:0% +i mean you need to be careful + + + align:start position:0% +i mean you need to be careful +so + + align:start position:0% +so + + + align:start position:0% +so +the bottom actually this is the taken + + align:start position:0% +the bottom actually this is the taken + + + align:start position:0% +the bottom actually this is the taken +message of the lecture if the + + align:start position:0% +message of the lecture if the + + + align:start position:0% +message of the lecture if the +illumination is specially coherent then + + align:start position:0% +illumination is specially coherent then + + + align:start position:0% +illumination is specially coherent then +input field is + + align:start position:0% +input field is + + + align:start position:0% +input field is +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +of the actually output field sorry after + + align:start position:0% +of the actually output field sorry after + + + align:start position:0% +of the actually output field sorry after +field is a convolution of input field + + align:start position:0% +field is a convolution of input field + + + align:start position:0% +field is a convolution of input field +with the coherent point spray function + + align:start position:0% +with the coherent point spray function + + + align:start position:0% +with the coherent point spray function +as we all know right + + align:start position:0% +as we all know right + + + align:start position:0% +as we all know right +but if the illumination is specially in + + align:start position:0% +but if the illumination is specially in + + + align:start position:0% +but if the illumination is specially in +coherent then + + align:start position:0% +coherent then + + + align:start position:0% +coherent then +output intensity not the output field so + + align:start position:0% +output intensity not the output field so + + + align:start position:0% +output intensity not the output field so +output intensity is a convolution + + align:start position:0% +output intensity is a convolution + + + align:start position:0% +output intensity is a convolution +of the input intensity + + align:start position:0% +of the input intensity + + + align:start position:0% +of the input intensity +with the + + align:start position:0% +with the + + + align:start position:0% +with the +in current 0.5 function + + align:start position:0% +in current 0.5 function + + + align:start position:0% +in current 0.5 function +so + + align:start position:0% +so + + + align:start position:0% +so +yeah so that's the + + align:start position:0% + + + + align:start position:0% + +which means + + align:start position:0% +which means + + + align:start position:0% +which means +if you have uh especially coherent + + align:start position:0% +if you have uh especially coherent + + + align:start position:0% +if you have uh especially coherent +imaging then + + align:start position:0% +imaging then + + + align:start position:0% +imaging then +field a linear system right you can do + + align:start position:0% +field a linear system right you can do + + + align:start position:0% +field a linear system right you can do +the convolution in field + + align:start position:0% +the convolution in field + + + align:start position:0% +the convolution in field +but if you + + align:start position:0% +but if you + + + align:start position:0% +but if you +if the elimination is in coherent then + + align:start position:0% +if the elimination is in coherent then + + + align:start position:0% +if the elimination is in coherent then +intensity is a linear system so you can + + align:start position:0% +intensity is a linear system so you can + + + align:start position:0% +intensity is a linear system so you can +deal with the intensity with the + + align:start position:0% +deal with the intensity with the + + + align:start position:0% +deal with the intensity with the +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +so yeah so rest of the lecture we're + + align:start position:0% +so yeah so rest of the lecture we're + + + align:start position:0% +so yeah so rest of the lecture we're +gonna deal with the + + align:start position:0% +gonna deal with the + + + align:start position:0% +gonna deal with the +uh special in coin elimination so how we + + align:start position:0% +uh special in coin elimination so how we + + + align:start position:0% +uh special in coin elimination so how we +can define uh point five function and + + align:start position:0% +can define uh point five function and + + + align:start position:0% +can define uh point five function and +transfer function and etc + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so first let's review uh what we + + align:start position:0% +so first let's review uh what we + + + align:start position:0% +so first let's review uh what we +have learned so far + + align:start position:0% +have learned so far + + + align:start position:0% +have learned so far +so we have four four f system with the + + align:start position:0% +so we have four four f system with the + + + align:start position:0% +so we have four four f system with the +two lengths + + align:start position:0% +two lengths + + + align:start position:0% +two lengths +whose focal lengths are f1 and f2 + + align:start position:0% +whose focal lengths are f1 and f2 + + + align:start position:0% +whose focal lengths are f1 and f2 +and typically we put our input + + align:start position:0% +and typically we put our input + + + align:start position:0% +and typically we put our input +transparency a grading at the input + + align:start position:0% +transparency a grading at the input + + + align:start position:0% +transparency a grading at the input +plane + + align:start position:0% +plane + + + align:start position:0% +plane +and we illuminate with the with + + align:start position:0% +and we illuminate with the with + + + align:start position:0% +and we illuminate with the with +especially coherent elimination and also + + align:start position:0% +especially coherent elimination and also + + + align:start position:0% +especially coherent elimination and also +temporary coherence right + + align:start position:0% + + + + align:start position:0% + +so the input field just arrived after + + align:start position:0% +so the input field just arrived after + + + align:start position:0% +so the input field just arrived after +the input transparency is going to be + + align:start position:0% +the input transparency is going to be + + + align:start position:0% +the input transparency is going to be +just product of the illumination field + + align:start position:0% +just product of the illumination field + + + align:start position:0% +just product of the illumination field +and the + + align:start position:0% +and the + + + align:start position:0% +and the +complex transparency that's the the + + align:start position:0% +complex transparency that's the the + + + align:start position:0% +complex transparency that's the the +input field and we're going to take the + + align:start position:0% +input field and we're going to take the + + + align:start position:0% +input field and we're going to take the +phase transform + + align:start position:0% +phase transform + + + align:start position:0% +phase transform +to get the field at the free plane and + + align:start position:0% +to get the field at the free plane and + + + align:start position:0% +to get the field at the free plane and +another fret transform you'll get the + + align:start position:0% +another fret transform you'll get the + + + align:start position:0% +another fret transform you'll get the +final image + + align:start position:0% +final image + + + align:start position:0% +final image +and from that we all know that + + align:start position:0% +and from that we all know that + + + align:start position:0% +and from that we all know that +uh amplitude transfer function is + + align:start position:0% +uh amplitude transfer function is + + + align:start position:0% +uh amplitude transfer function is +nothing but + + align:start position:0% +nothing but + + + align:start position:0% +nothing but +the purple + + align:start position:0% +the purple + + + align:start position:0% +the purple +uh ppl mask function with the + + align:start position:0% +uh ppl mask function with the + + + align:start position:0% +uh ppl mask function with the +coordinate scaling right so atf h of u + + align:start position:0% +coordinate scaling right so atf h of u + + + align:start position:0% +coordinate scaling right so atf h of u +and v is + + align:start position:0% +and v is + + + align:start position:0% +and v is +some constant and + + align:start position:0% +some constant and + + + align:start position:0% +some constant and +p mass function + + align:start position:0% +p mass function + + + align:start position:0% +p mass function +and lambda f 1 u and lambda 1 v + + align:start position:0% + + + + align:start position:0% + +and the + + align:start position:0% +and the + + + align:start position:0% +and the +point function in field is + + align:start position:0% +point function in field is + + + align:start position:0% +point function in field is +just free transform of the + + align:start position:0% +just free transform of the + + + align:start position:0% +just free transform of the +atf so + + align:start position:0% +atf so + + + align:start position:0% +atf so +or you can say it's free transform the + + align:start position:0% +or you can say it's free transform the + + + align:start position:0% +or you can say it's free transform the +purple function + + align:start position:0% +purple function + + + align:start position:0% +purple function +so this is the coherent points function + + align:start position:0% +so this is the coherent points function + + + align:start position:0% +so this is the coherent points function +and you can define coincident function + + align:start position:0% +and you can define coincident function + + + align:start position:0% +and you can define coincident function +in reduced coordinate + + align:start position:0% +in reduced coordinate + + + align:start position:0% +in reduced coordinate +and the relation in between input and + + align:start position:0% +and the relation in between input and + + + align:start position:0% +and the relation in between input and +output field is + + align:start position:0% +output field is + + + align:start position:0% +output field is +this convolution right so g output i + + align:start position:0% +this convolution right so g output i + + + align:start position:0% +this convolution right so g output i +mean output field is convolutional input + + align:start position:0% +mean output field is convolutional input + + + align:start position:0% +mean output field is convolutional input +field and this is coherent point + + align:start position:0% +field and this is coherent point + + + align:start position:0% +field and this is coherent point +function which is defined in field + + align:start position:0% +function which is defined in field + + + align:start position:0% +function which is defined in field +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +this is the stuff that we all know + + align:start position:0% +this is the stuff that we all know + + + align:start position:0% +this is the stuff that we all know +so the next thing is + + align:start position:0% +so the next thing is + + + align:start position:0% +so the next thing is +let's + + align:start position:0% +let's + + + align:start position:0% +let's +let me put the two pin holes at the + + align:start position:0% +let me put the two pin holes at the + + + align:start position:0% +let me put the two pin holes at the +input plane so + + align:start position:0% + + + + align:start position:0% + +and illuminate with especially coherent + + align:start position:0% +and illuminate with especially coherent + + + align:start position:0% +and illuminate with especially coherent +light + + align:start position:0% +light + + + align:start position:0% +light +so basically we have young + + align:start position:0% +so basically we have young + + + align:start position:0% +so basically we have young +interferometer here and + + align:start position:0% +interferometer here and + + + align:start position:0% +interferometer here and +i'm gonna image that + + align:start position:0% +i'm gonna image that + + + align:start position:0% +i'm gonna image that +pattern + + align:start position:0% + + + + align:start position:0% + +and since it is coherent you see it is + + align:start position:0% +and since it is coherent you see it is + + + align:start position:0% +and since it is coherent you see it is +illuminated with the coherent line so + + align:start position:0% +illuminated with the coherent line so + + + align:start position:0% +illuminated with the coherent line so +what essentially + + align:start position:0% +what essentially + + + align:start position:0% +what essentially +i have at the image plane is actually + + align:start position:0% +i have at the image plane is actually + + + align:start position:0% +i have at the image plane is actually +2.3 function + + align:start position:0% +2.3 function + + + align:start position:0% +2.3 function +coming from two pin all right so in the + + align:start position:0% +coming from two pin all right so in the + + + align:start position:0% +coming from two pin all right so in the +upper image actually coming from the + + align:start position:0% +upper image actually coming from the + + + align:start position:0% +upper image actually coming from the +lower panel and the lower image actually + + align:start position:0% +lower panel and the lower image actually + + + align:start position:0% +lower panel and the lower image actually +coming from the upper pinout but i have + + align:start position:0% +coming from the upper pinout but i have + + + align:start position:0% +coming from the upper pinout but i have +the addition + + align:start position:0% +the addition + + + align:start position:0% +the addition +of two + + align:start position:0% +of two + + + align:start position:0% +of two +point three function which is shifted by + + align:start position:0% +point three function which is shifted by + + + align:start position:0% +point three function which is shifted by +the position of the p-troop signal and i + + align:start position:0% +the position of the p-troop signal and i + + + align:start position:0% +the position of the p-troop signal and i +may have some initial phase a one e to + + align:start position:0% +may have some initial phase a one e to + + + align:start position:0% +may have some initial phase a one e to +the e to the phi one and a two e to the + + align:start position:0% +the e to the phi one and a two e to the + + + align:start position:0% +the e to the phi one and a two e to the +phi two but the bottom line is in quran + + align:start position:0% +phi two but the bottom line is in quran + + + align:start position:0% +phi two but the bottom line is in quran +case i just have + + align:start position:0% +case i just have + + + align:start position:0% +case i just have +coherent addition of 2.3 function like + + align:start position:0% +coherent addition of 2.3 function like + + + align:start position:0% +coherent addition of 2.3 function like +this + + align:start position:0% +this + + + align:start position:0% +this +and to get the intensity + + align:start position:0% +and to get the intensity + + + align:start position:0% +and to get the intensity +as you all know you just + + align:start position:0% +as you all know you just + + + align:start position:0% +as you all know you just +take the magnitude square + + align:start position:0% +take the magnitude square + + + align:start position:0% +take the magnitude square +of the sum and if we expand it then we + + align:start position:0% +of the sum and if we expand it then we + + + align:start position:0% +of the sum and if we expand it then we +have + + align:start position:0% +have + + + align:start position:0% +have +two dc term which is intensity of the + + align:start position:0% +two dc term which is intensity of the + + + align:start position:0% +two dc term which is intensity of the +first point sphere function and + + align:start position:0% +first point sphere function and + + + align:start position:0% +first point sphere function and +intensity of the second point function + + align:start position:0% +intensity of the second point function + + + align:start position:0% +intensity of the second point function +and we have some additional + + align:start position:0% +and we have some additional + + + align:start position:0% +and we have some additional +modulation term which means i have some + + align:start position:0% +modulation term which means i have some + + + align:start position:0% +modulation term which means i have some +interference right so it's a1 a2 and + + align:start position:0% +interference right so it's a1 a2 and + + + align:start position:0% +interference right so it's a1 a2 and +rear part of this guy + + align:start position:0% +rear part of this guy + + + align:start position:0% +rear part of this guy +but you know real part is always cosine + + align:start position:0% +but you know real part is always cosine + + + align:start position:0% +but you know real part is always cosine +right so if you change the face + + align:start position:0% +right so if you change the face + + + align:start position:0% +right so if you change the face +you have some cos sinusoidal modulation + + align:start position:0% +you have some cos sinusoidal modulation + + + align:start position:0% +you have some cos sinusoidal modulation +term + + align:start position:0% + + + + align:start position:0% + +yeah so this is sometimes called + + align:start position:0% +yeah so this is sometimes called + + + align:start position:0% +yeah so this is sometimes called +interference term or + + align:start position:0% +interference term or + + + align:start position:0% +interference term or +cluster + + align:start position:0% +cluster + + + align:start position:0% +cluster +implies that you have interference + + align:start position:0% +implies that you have interference + + + align:start position:0% +implies that you have interference +so with + + align:start position:0% +so with + + + align:start position:0% +so with +this parameter so initial phase is just + + align:start position:0% +this parameter so initial phase is just + + + align:start position:0% +this parameter so initial phase is just +e to the uh negative pi over 3 and + + align:start position:0% +e to the uh negative pi over 3 and + + + align:start position:0% +e to the uh negative pi over 3 and +the other one is pi the positive pi over + + align:start position:0% +the other one is pi the positive pi over + + + align:start position:0% +the other one is pi the positive pi over + + align:start position:0% + + + align:start position:0% +then if i plot this intensity + + align:start position:0% +then if i plot this intensity + + + align:start position:0% +then if i plot this intensity +then + + align:start position:0% +then + + + align:start position:0% +then +i'm going to have this kind this blue + + align:start position:0% +i'm going to have this kind this blue + + + align:start position:0% +i'm going to have this kind this blue +line + + align:start position:0% + + + + align:start position:0% + +yeah so this is the case of especially + + align:start position:0% +yeah so this is the case of especially + + + align:start position:0% +yeah so this is the case of especially +coherent illumination + + align:start position:0% +coherent illumination + + + align:start position:0% +coherent illumination +and + + align:start position:0% +and + + + align:start position:0% +and +so next let's suppose if i illuminate + + align:start position:0% +so next let's suppose if i illuminate + + + align:start position:0% +so next let's suppose if i illuminate +with the in current in coin elimination + + align:start position:0% +with the in current in coin elimination + + + align:start position:0% +with the in current in coin elimination +so + + align:start position:0% +so + + + align:start position:0% +so +uh as i as + + align:start position:0% +uh as i as + + + align:start position:0% +uh as i as +as i described earlier so the difference + + align:start position:0% +as i described earlier so the difference + + + align:start position:0% +as i described earlier so the difference +between in korean and korean is you know + + align:start position:0% +between in korean and korean is you know + + + align:start position:0% +between in korean and korean is you know +i don't have interference term if i + + align:start position:0% +i don't have interference term if i + + + align:start position:0% +i don't have interference term if i +eliminate with the + + align:start position:0% +eliminate with the + + + align:start position:0% +eliminate with the +incoherent source right so at the + + align:start position:0% +incoherent source right so at the + + + align:start position:0% +incoherent source right so at the +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +i only have these two terms just + + align:start position:0% +i only have these two terms just + + + align:start position:0% +i only have these two terms just +intensity of the first position function + + align:start position:0% +intensity of the first position function + + + align:start position:0% +intensity of the first position function +and intensity of the second point + + align:start position:0% +and intensity of the second point + + + align:start position:0% +and intensity of the second point +function and i don't have this the extra + + align:start position:0% +function and i don't have this the extra + + + align:start position:0% +function and i don't have this the extra +cosine term + + align:start position:0% +cosine term + + + align:start position:0% +cosine term +so this is just + + align:start position:0% +so this is just + + + align:start position:0% +so this is just +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +so + + align:start position:0% + + + + align:start position:0% + +if i plot the intensity with the same + + align:start position:0% +if i plot the intensity with the same + + + align:start position:0% +if i plot the intensity with the same +parameter then this is how it looks like + + align:start position:0% +parameter then this is how it looks like + + + align:start position:0% +parameter then this is how it looks like +and if i put together + + align:start position:0% +and if i put together + + + align:start position:0% +and if i put together +then the upper left is the + + align:start position:0% +then the upper left is the + + + align:start position:0% +then the upper left is the +the + + align:start position:0% +the + + + align:start position:0% +the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the two intensity uh profile + + align:start position:0% +the two intensity uh profile + + + align:start position:0% +the two intensity uh profile +of cohen and in current elimination + + align:start position:0% +of cohen and in current elimination + + + align:start position:0% +of cohen and in current elimination +so they are slightly different right + + align:start position:0% +so they are slightly different right + + + align:start position:0% +so they are slightly different right +and if i play with a different parameter + + align:start position:0% +and if i play with a different parameter + + + align:start position:0% +and if i play with a different parameter +like uh with different an interface + + align:start position:0% +like uh with different an interface + + + align:start position:0% +like uh with different an interface +and in this case + + align:start position:0% +and in this case + + + align:start position:0% +and in this case +my positive function is as extra linear + + align:start position:0% +my positive function is as extra linear + + + align:start position:0% +my positive function is as extra linear +phase term then the difference is quite + + align:start position:0% +phase term then the difference is quite + + + align:start position:0% +phase term then the difference is quite +dramatic + + align:start position:0% +dramatic + + + align:start position:0% +dramatic +so you always have to careful what kind + + align:start position:0% +so you always have to careful what kind + + + align:start position:0% +so you always have to careful what kind +of coherence + + align:start position:0% +of coherence + + + align:start position:0% +of coherence +your elimination is + + align:start position:0% + + + + align:start position:0% + +any question + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yeah so + + align:start position:0% + + + + align:start position:0% + +in previous case which is especially + + align:start position:0% +in previous case which is especially + + + align:start position:0% +in previous case which is especially +coherent then the input field and output + + align:start position:0% +coherent then the input field and output + + + align:start position:0% +coherent then the input field and output +field is + + align:start position:0% +field is + + + align:start position:0% +field is +they are linear so you can use the + + align:start position:0% +they are linear so you can use the + + + align:start position:0% +they are linear so you can use the +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +but + + align:start position:0% +but + + + align:start position:0% +but +in + + align:start position:0% +in + + + align:start position:0% +in +especially in coherent case + + align:start position:0% + + + + align:start position:0% + +so we deal with the input intensity + + align:start position:0% +so we deal with the input intensity + + + align:start position:0% +so we deal with the input intensity +which is + + align:start position:0% +which is + + + align:start position:0% +which is +uh which is + + align:start position:0% + + + + align:start position:0% + +i don't know so we're gonna deal with + + align:start position:0% +i don't know so we're gonna deal with + + + align:start position:0% +i don't know so we're gonna deal with +the input intensity and output intensity + + align:start position:0% +the input intensity and output intensity + + + align:start position:0% +the input intensity and output intensity +and at the image plane + + align:start position:0% +and at the image plane + + + align:start position:0% +and at the image plane +the intensity will be + + align:start position:0% +the intensity will be + + + align:start position:0% +the intensity will be +will be summed in currently + + align:start position:0% +will be summed in currently + + + align:start position:0% +will be summed in currently +so + + align:start position:0% + + + + align:start position:0% + +so i used i illuminate with a + + align:start position:0% +so i used i illuminate with a + + + align:start position:0% +so i used i illuminate with a +intensity i mean increasing in coherent + + align:start position:0% +intensity i mean increasing in coherent + + + align:start position:0% +intensity i mean increasing in coherent +illumination with the intensity i illume + + align:start position:0% +illumination with the intensity i illume + + + align:start position:0% +illumination with the intensity i illume +and g sub t is the complex transparency + + align:start position:0% +and g sub t is the complex transparency + + + align:start position:0% +and g sub t is the complex transparency +but you know this is in this is field so + + align:start position:0% +but you know this is in this is field so + + + align:start position:0% +but you know this is in this is field so +you have to take + + align:start position:0% +you have to take + + + align:start position:0% +you have to take +negative square so + + align:start position:0% +negative square so + + + align:start position:0% +negative square so +product of this guy + + align:start position:0% +product of this guy + + + align:start position:0% +product of this guy +this guy + + align:start position:0% +this guy + + + align:start position:0% +this guy +is basically your input intensity right + + align:start position:0% +is basically your input intensity right + + + align:start position:0% +is basically your input intensity right +so this illumination intensity and + + align:start position:0% +so this illumination intensity and + + + align:start position:0% +so this illumination intensity and +intensity of your grading + + align:start position:0% +intensity of your grading + + + align:start position:0% +intensity of your grading +and + + align:start position:0% +and + + + align:start position:0% +and +this is + + align:start position:0% + + + + align:start position:0% + +this is point square function + + align:start position:0% +this is point square function + + + align:start position:0% +this is point square function +actually coherent points function but + + align:start position:0% +actually coherent points function but + + + align:start position:0% +actually coherent points function but +you take the magnitude square + + align:start position:0% +you take the magnitude square + + + align:start position:0% +you take the magnitude square +right because you know you take the + + align:start position:0% +right because you know you take the + + + align:start position:0% +right because you know you take the +magnitude square to get intensity so we + + align:start position:0% +magnitude square to get intensity so we + + + align:start position:0% +magnitude square to get intensity so we +define + + align:start position:0% +define + + + align:start position:0% +define +excuse me the defined equivalent points + + align:start position:0% +excuse me the defined equivalent points + + + align:start position:0% +excuse me the defined equivalent points +of function + + align:start position:0% +of function + + + align:start position:0% +of function +which is ipsf is actually negative + + align:start position:0% +which is ipsf is actually negative + + + align:start position:0% +which is ipsf is actually negative +square of the coherent pointer function + + align:start position:0% +square of the coherent pointer function + + + align:start position:0% +square of the coherent pointer function +it's pretty simple right you have + + align:start position:0% +it's pretty simple right you have + + + align:start position:0% +it's pretty simple right you have +coins um + + align:start position:0% +coins um + + + align:start position:0% +coins um +points a function in fair and if you + + align:start position:0% +points a function in fair and if you + + + align:start position:0% +points a function in fair and if you +just take the intensity then that's the + + align:start position:0% +just take the intensity then that's the + + + align:start position:0% +just take the intensity then that's the +you know intensity points for function + + align:start position:0% +you know intensity points for function + + + align:start position:0% +you know intensity points for function +but + + align:start position:0% +but + + + align:start position:0% +but +but + + align:start position:0% +but + + + align:start position:0% +but +you you probably already noticed the + + align:start position:0% +you you probably already noticed the + + + align:start position:0% +you you probably already noticed the +difference right so if you use the + + align:start position:0% +difference right so if you use the + + + align:start position:0% +difference right so if you use the +coherent case if you use the coherent + + align:start position:0% +coherent case if you use the coherent + + + align:start position:0% +coherent case if you use the coherent +elimination then + + align:start position:0% +elimination then + + + align:start position:0% +elimination then +the fields are + + align:start position:0% +the fields are + + + align:start position:0% +the fields are +related to convolution but in current + + align:start position:0% +related to convolution but in current + + + align:start position:0% +related to convolution but in current +case intensity are related to + + align:start position:0% +case intensity are related to + + + align:start position:0% +case intensity are related to +convolution + + align:start position:0% + + + + align:start position:0% + +and points of function are different + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +any question + + align:start position:0% +any question + + + align:start position:0% +any question +i'm going to a little bit fast so + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so + + align:start position:0% + + + + align:start position:0% + +so we just defined the intensity + + align:start position:0% +so we just defined the intensity + + + align:start position:0% +so we just defined the intensity +intensity points function which is + + align:start position:0% +intensity points function which is + + + align:start position:0% +intensity points function which is +magnitude square of current point side + + align:start position:0% +magnitude square of current point side + + + align:start position:0% +magnitude square of current point side +function + + align:start position:0% +function + + + align:start position:0% +function +and by analogy that i mean + + align:start position:0% +and by analogy that i mean + + + align:start position:0% +and by analogy that i mean +uh in + + align:start position:0% +uh in + + + align:start position:0% +uh in +the coherence case we had the current + + align:start position:0% +the coherence case we had the current + + + align:start position:0% +the coherence case we had the current +point spread function and if you take + + align:start position:0% +point spread function and if you take + + + align:start position:0% +point spread function and if you take +the free transform of the coherent point + + align:start position:0% +the free transform of the coherent point + + + align:start position:0% +the free transform of the coherent point +function then there is that is atf right + + align:start position:0% +function then there is that is atf right + + + align:start position:0% +function then there is that is atf right +amplitude transfer function + + align:start position:0% +amplitude transfer function + + + align:start position:0% +amplitude transfer function +so we can define the same transfer + + align:start position:0% +so we can define the same transfer + + + align:start position:0% +so we can define the same transfer +function for in core in coherent point + + align:start position:0% +function for in core in coherent point + + + align:start position:0% +function for in core in coherent point +function which is otf here + + align:start position:0% +function which is otf here + + + align:start position:0% +function which is otf here +so that's derivation that + + align:start position:0% +so that's derivation that + + + align:start position:0% +so that's derivation that +deviation says that + + align:start position:0% + + + + align:start position:0% + +so actually + + align:start position:0% +so actually + + + align:start position:0% +so actually +the small h is the + + align:start position:0% +the small h is the + + + align:start position:0% +the small h is the +coherent point function and + + align:start position:0% +coherent point function and + + + align:start position:0% +coherent point function and +the capital h is + + align:start position:0% +the capital h is + + + align:start position:0% +the capital h is +atf + + align:start position:0% +atf + + + align:start position:0% +atf +which is so they are + + align:start position:0% +which is so they are + + + align:start position:0% +which is so they are +free to some pair + + align:start position:0% +free to some pair + + + align:start position:0% +free to some pair +and h i which is intensity point three + + align:start position:0% +and h i which is intensity point three + + + align:start position:0% +and h i which is intensity point three +function is the magnitude square of the + + align:start position:0% +function is the magnitude square of the + + + align:start position:0% +function is the magnitude square of the +coherent point of function + + align:start position:0% +coherent point of function + + + align:start position:0% +coherent point of function +but h i and + + align:start position:0% +but h i and + + + align:start position:0% +but h i and +otf which is + + align:start position:0% +otf which is + + + align:start position:0% +otf which is +uh this + + align:start position:0% +uh this + + + align:start position:0% +uh this +uh + + align:start position:0% +uh + + + align:start position:0% +uh +weird h + + align:start position:0% +weird h + + + align:start position:0% +weird h +they are + + align:start position:0% +they are + + + align:start position:0% +they are +here actually they are also transform a + + align:start position:0% +here actually they are also transform a + + + align:start position:0% +here actually they are also transform a +free transform pair + + align:start position:0% +free transform pair + + + align:start position:0% +free transform pair +so if you go through this derivation + + align:start position:0% +so if you go through this derivation + + + align:start position:0% +so if you go through this derivation +then + + align:start position:0% +then + + + align:start position:0% +then +it will prove actually they are + + align:start position:0% +it will prove actually they are + + + align:start position:0% +it will prove actually they are +actually to prove that + + align:start position:0% + + + + align:start position:0% + +otf is + + align:start position:0% + + + + align:start position:0% + +otf is actually + + align:start position:0% +otf is actually + + + align:start position:0% +otf is actually +this integration of + + align:start position:0% +this integration of + + + align:start position:0% +this integration of +atf + + align:start position:0% +atf + + + align:start position:0% +atf +so if you once you have atf and you can + + align:start position:0% +so if you once you have atf and you can + + + align:start position:0% +so if you once you have atf and you can +compute and + + align:start position:0% +compute and + + + align:start position:0% +compute and +after you compute this integration then + + align:start position:0% +after you compute this integration then + + + align:start position:0% +after you compute this integration then +you get rtf which is autocorrelation + + align:start position:0% +you get rtf which is autocorrelation + + + align:start position:0% +you get rtf which is autocorrelation +and i'm gonna + + align:start position:0% +and i'm gonna + + + align:start position:0% +and i'm gonna +derive + + align:start position:0% +derive + + + align:start position:0% +derive +in different way here + + align:start position:0% + + + + align:start position:0% + +so can i use darken please + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +we start with h i of x + + align:start position:0% +we start with h i of x + + + align:start position:0% +we start with h i of x +which is intensity point function is + + align:start position:0% +which is intensity point function is + + + align:start position:0% +which is intensity point function is +magnitude square of the coherent point + + align:start position:0% +magnitude square of the coherent point + + + align:start position:0% +magnitude square of the coherent point +function + + align:start position:0% +function + + + align:start position:0% +function +and yes + + align:start position:0% +and yes + + + align:start position:0% +and yes +much bigger + + align:start position:0% +much bigger + + + align:start position:0% +much bigger +all right + + align:start position:0% + + + + align:start position:0% + +okay let me + + align:start position:0% +okay let me + + + align:start position:0% +okay let me +try + + align:start position:0% +try + + + align:start position:0% +try +that's too big + + align:start position:0% + + + + align:start position:0% + +it's too small okay + + align:start position:0% + + + + align:start position:0% + +it will get smaller + + align:start position:0% +it will get smaller + + + align:start position:0% +it will get smaller +yeah we start with this thing and + + align:start position:0% +yeah we start with this thing and + + + align:start position:0% +yeah we start with this thing and +we know that the otf + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +free transform + + align:start position:0% +free transform + + + align:start position:0% +free transform +of intensity + + align:start position:0% +of intensity + + + align:start position:0% +of intensity +point spread function + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +and i can just plug in here so is fret + + align:start position:0% +and i can just plug in here so is fret + + + align:start position:0% +and i can just plug in here so is fret +transform + + align:start position:0% +transform + + + align:start position:0% +transform +of + + align:start position:0% +of + + + align:start position:0% +of +magnitude square + + align:start position:0% +magnitude square + + + align:start position:0% +magnitude square +of the points of coherent points of + + align:start position:0% +of the points of coherent points of + + + align:start position:0% +of the points of coherent points of +function + + align:start position:0% +function + + + align:start position:0% +function +and free transform + + align:start position:0% +and free transform + + + align:start position:0% +and free transform +and + + align:start position:0% +and + + + align:start position:0% +and +since this is complex quantity i can + + align:start position:0% +since this is complex quantity i can + + + align:start position:0% +since this is complex quantity i can +write + + align:start position:0% +write + + + align:start position:0% +write +as + + align:start position:0% +as + + + align:start position:0% +as +h of x + + align:start position:0% +h of x + + + align:start position:0% +h of x +and it's complex conjugate + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +and since these two are product + + align:start position:0% +and since these two are product + + + align:start position:0% +and since these two are product +then i can write as convolution + + align:start position:0% +then i can write as convolution + + + align:start position:0% +then i can write as convolution +of two guys so it's first transform + + align:start position:0% +of two guys so it's first transform + + + align:start position:0% +of two guys so it's first transform +of h of x + + align:start position:0% +of h of x + + + align:start position:0% +of h of x +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +with fret transform + + align:start position:0% +with fret transform + + + align:start position:0% +with fret transform +of + + align:start position:0% +of + + + align:start position:0% +of +a complex conjugate + + align:start position:0% +a complex conjugate + + + align:start position:0% +a complex conjugate +like this + + align:start position:0% + + + + align:start position:0% + +up pretty straightforward right + + align:start position:0% +up pretty straightforward right + + + align:start position:0% +up pretty straightforward right +and + + align:start position:0% +and + + + align:start position:0% +and +you know + + align:start position:0% +you know + + + align:start position:0% +you know +flat transform of the age is actually + + align:start position:0% +flat transform of the age is actually + + + align:start position:0% +flat transform of the age is actually +h of u + + align:start position:0% +h of u + + + align:start position:0% +h of u +right + + align:start position:0% +right + + + align:start position:0% +right +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +this guy + + align:start position:0% + + + + align:start position:0% + +atf is just nothing but frequencies of + + align:start position:0% +atf is just nothing but frequencies of + + + align:start position:0% +atf is just nothing but frequencies of +the + + align:start position:0% +the + + + align:start position:0% +the +coherent points function + + align:start position:0% +coherent points function + + + align:start position:0% +coherent points function +and what about this guy + + align:start position:0% +and what about this guy + + + align:start position:0% +and what about this guy +the transform of + + align:start position:0% +the transform of + + + align:start position:0% +the transform of +complex conjugate of h + + align:start position:0% +complex conjugate of h + + + align:start position:0% +complex conjugate of h +small h + + align:start position:0% +small h + + + align:start position:0% +small h +so i can write this in integral form so + + align:start position:0% +so i can write this in integral form so + + + align:start position:0% +so i can write this in integral form so +integral + + align:start position:0% +integral + + + align:start position:0% +integral +each complex conjugate of x + + align:start position:0% +each complex conjugate of x + + + align:start position:0% +each complex conjugate of x +e to the + + align:start position:0% +e to the + + + align:start position:0% +e to the +minus j 2 pi + + align:start position:0% +minus j 2 pi + + + align:start position:0% +minus j 2 pi +x u + + align:start position:0% +x u + + + align:start position:0% +x u +d x + + align:start position:0% + + + + align:start position:0% + +and since it is complex conjugate i can + + align:start position:0% +and since it is complex conjugate i can + + + align:start position:0% +and since it is complex conjugate i can +write as + + align:start position:0% +write as + + + align:start position:0% +write as +integral + + align:start position:0% +integral + + + align:start position:0% +integral +h of x + + align:start position:0% +h of x + + + align:start position:0% +h of x +e to the i 2 pi + + align:start position:0% +e to the i 2 pi + + + align:start position:0% +e to the i 2 pi +x u + + align:start position:0% +x u + + + align:start position:0% +x u +d x + + align:start position:0% + + + + align:start position:0% + +x and conjugate + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +so i can + + align:start position:0% +so i can + + + align:start position:0% +so i can +write + + align:start position:0% +write + + + align:start position:0% +write +as + + align:start position:0% +as + + + align:start position:0% +as +otf + + align:start position:0% +otf + + + align:start position:0% +otf +is + + align:start position:0% +is + + + align:start position:0% +is +hou + + align:start position:0% + + + + align:start position:0% + +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +and + + align:start position:0% + + + + align:start position:0% + +complex conjugate or free transform of + + align:start position:0% + + + + align:start position:0% + +like this + + align:start position:0% + + + + align:start position:0% + +actually + + align:start position:0% +actually + + + align:start position:0% +actually +inverse spread transform yes + + align:start position:0% +inverse spread transform yes + + + align:start position:0% +inverse spread transform yes +thanks + + align:start position:0% + + + + align:start position:0% + +so actually this inverse transform if + + align:start position:0% +so actually this inverse transform if + + + align:start position:0% +so actually this inverse transform if +you remember + + align:start position:0% +you remember + + + align:start position:0% +you remember +the definition of the fret transform is + + align:start position:0% +the definition of the fret transform is + + + align:start position:0% +the definition of the fret transform is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +you know + + align:start position:0% +you know + + + align:start position:0% +you know +of + + align:start position:0% +of + + + align:start position:0% +of +integral h of x + + align:start position:0% +integral h of x + + + align:start position:0% +integral h of x +e to the i 2 pi x u d x when you can + + align:start position:0% +e to the i 2 pi x u d x when you can + + + align:start position:0% +e to the i 2 pi x u d x when you can +write as uh + + align:start position:0% +write as uh + + + align:start position:0% +write as uh +h of x + + align:start position:0% +h of x + + + align:start position:0% +h of x +e to the + + align:start position:0% +e to the + + + align:start position:0% +e to the +minus 2 pi + + align:start position:0% +minus 2 pi + + + align:start position:0% +minus 2 pi +x minus u dx so actually it is fret + + align:start position:0% +x minus u dx so actually it is fret + + + align:start position:0% +x minus u dx so actually it is fret +transform + + align:start position:0% +transform + + + align:start position:0% +transform +and h of x + + align:start position:0% +and h of x + + + align:start position:0% +and h of x +but you change the spatial frequency + + align:start position:0% +but you change the spatial frequency + + + align:start position:0% +but you change the spatial frequency +variable as a minus u so it's going to + + align:start position:0% +variable as a minus u so it's going to + + + align:start position:0% +variable as a minus u so it's going to +be h of minus u + + align:start position:0% + + + + align:start position:0% + +so at the end we have we have + + align:start position:0% +so at the end we have we have + + + align:start position:0% +so at the end we have we have +h of u + + align:start position:0% +h of u + + + align:start position:0% +h of u +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +and complex conjugate of + + align:start position:0% + + + + align:start position:0% + +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +h complex conjugate or minus uh + + align:start position:0% + + + + align:start position:0% + +which is + + align:start position:0% +which is + + + align:start position:0% +which is +where i can write as an integral form + + align:start position:0% +where i can write as an integral form + + + align:start position:0% +where i can write as an integral form +integration + + align:start position:0% +integration + + + align:start position:0% +integration +h of u prime + + align:start position:0% +h of u prime + + + align:start position:0% +h of u prime +h of + + align:start position:0% +h of + + + align:start position:0% +h of +um + + align:start position:0% + + + + align:start position:0% + +h of minus + + align:start position:0% +h of minus + + + align:start position:0% +h of minus +u minus u prime + + align:start position:0% +u minus u prime + + + align:start position:0% +u minus u prime +complex conjugate + + align:start position:0% +complex conjugate + + + align:start position:0% +complex conjugate +and d u prime so essentially + + align:start position:0% +and d u prime so essentially + + + align:start position:0% +and d u prime so essentially +integration h complex conjugate + + align:start position:0% +integration h complex conjugate + + + align:start position:0% +integration h complex conjugate +no + + align:start position:0% +no + + + align:start position:0% +no +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +so + + align:start position:0% +so + + + align:start position:0% +so +i have com + + align:start position:0% +i have com + + + align:start position:0% +i have com +h of + + align:start position:0% +h of + + + align:start position:0% +h of +u prime + + align:start position:0% +u prime + + + align:start position:0% +u prime +complex conjugate + + align:start position:0% +complex conjugate + + + align:start position:0% +complex conjugate +u prime + + align:start position:0% +u prime + + + align:start position:0% +u prime +minus u + + align:start position:0% +minus u + + + align:start position:0% +minus u +d u prime + + align:start position:0% +d u prime + + + align:start position:0% +d u prime +which is essentially + + align:start position:0% +which is essentially + + + align:start position:0% +which is essentially +this guy + + align:start position:0% +this guy + + + align:start position:0% +this guy +in one + + align:start position:0% +in one + + + align:start position:0% +in one +1d + + align:start position:0% +1d + + + align:start position:0% +1d +one dimensional geometry + + align:start position:0% + + + + align:start position:0% + +and sometimes we denote + + align:start position:0% +and sometimes we denote + + + align:start position:0% +and sometimes we denote +by + + align:start position:0% +by + + + align:start position:0% +by +h of u + + align:start position:0% +h of u + + + align:start position:0% +h of u +and star + + align:start position:0% +and star + + + align:start position:0% +and star +h of u + + align:start position:0% +h of u + + + align:start position:0% +h of u +which is + + align:start position:0% +which is + + + align:start position:0% +which is +auto + + align:start position:0% + + + + align:start position:0% + +correlation + + align:start position:0% + + + + align:start position:0% + +any question in the derivation + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so before uh we move on uh can anyone + + align:start position:0% +so before uh we move on uh can anyone + + + align:start position:0% +so before uh we move on uh can anyone +guess what this integration means + + align:start position:0% +guess what this integration means + + + align:start position:0% +guess what this integration means +so you have your own computer in otf + + align:start position:0% +so you have your own computer in otf + + + align:start position:0% +so you have your own computer in otf +which is autocorrelation or the atf but + + align:start position:0% +which is autocorrelation or the atf but + + + align:start position:0% +which is autocorrelation or the atf but +this integration is basically you have + + align:start position:0% + + + + align:start position:0% + +h + + align:start position:0% +h + + + align:start position:0% +h +and you take the complex conjugate but + + align:start position:0% +and you take the complex conjugate but + + + align:start position:0% +and you take the complex conjugate but +you shift right and take the integral + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +so next slide i'm gonna explain how we + + align:start position:0% +so next slide i'm gonna explain how we + + + align:start position:0% +so next slide i'm gonna explain how we +can compute i mean + + align:start position:0% +can compute i mean + + + align:start position:0% +can compute i mean +so + + align:start position:0% +so + + + align:start position:0% +so +the bottom line of this slide is you + + align:start position:0% +the bottom line of this slide is you + + + align:start position:0% +the bottom line of this slide is you +know otf is nothing but autocorrelation + + align:start position:0% +know otf is nothing but autocorrelation + + + align:start position:0% +know otf is nothing but autocorrelation +of your atf + + align:start position:0% +of your atf + + + align:start position:0% +of your atf +and the next slide is how to compute + + align:start position:0% +and the next slide is how to compute + + + align:start position:0% +and the next slide is how to compute +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +you can simply compute this integration + + align:start position:0% +you can simply compute this integration + + + align:start position:0% +you can simply compute this integration +but there is another easy way + + align:start position:0% +but there is another easy way + + + align:start position:0% +but there is another easy way +to guess the otf + + align:start position:0% + + + + align:start position:0% + +conceptually yes i mean actually the + + align:start position:0% +conceptually yes i mean actually the + + + align:start position:0% +conceptually yes i mean actually the +transform of the + + align:start position:0% +transform of the + + + align:start position:0% +transform of the +input intensity and flex ratio of the + + align:start position:0% +input intensity and flex ratio of the + + + align:start position:0% +input intensity and flex ratio of the +upper intensity and the rate of the two + + align:start position:0% +upper intensity and the rate of the two + + + align:start position:0% +upper intensity and the rate of the two +likes + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so let's first compute the otf for the + + align:start position:0% +so let's first compute the otf for the + + + align:start position:0% +so let's first compute the otf for the +simple case + + align:start position:0% +simple case + + + align:start position:0% +simple case +i have the rectangular aperture in my + + align:start position:0% +i have the rectangular aperture in my + + + align:start position:0% +i have the rectangular aperture in my +purple from trippy plane at the free + + align:start position:0% +purple from trippy plane at the free + + + align:start position:0% +purple from trippy plane at the free +plane + + align:start position:0% +plane + + + align:start position:0% +plane +and from that i know that the atf h of u + + align:start position:0% +and from that i know that the atf h of u + + + align:start position:0% +and from that i know that the atf h of u +is just vector function and u over u max + + align:start position:0% +is just vector function and u over u max + + + align:start position:0% +is just vector function and u over u max +so u max is defined by the physical size + + align:start position:0% +so u max is defined by the physical size + + + align:start position:0% +so u max is defined by the physical size +of the previous function right and + + align:start position:0% +of the previous function right and + + + align:start position:0% +of the previous function right and +so which is x double prime x and + + align:start position:0% +so which is x double prime x and + + + align:start position:0% +so which is x double prime x and +with + + align:start position:0% +with + + + align:start position:0% +with +the scaling vector of lambda f1 + + align:start position:0% +the scaling vector of lambda f1 + + + align:start position:0% +the scaling vector of lambda f1 +so this is the at + + align:start position:0% +so this is the at + + + align:start position:0% +so this is the at +atf + + align:start position:0% +atf + + + align:start position:0% +atf +and + + align:start position:0% +and + + + align:start position:0% +and +we just i just proved that otf is + + align:start position:0% +we just i just proved that otf is + + + align:start position:0% +we just i just proved that otf is +autocorrelation of atf + + align:start position:0% +autocorrelation of atf + + + align:start position:0% +autocorrelation of atf +in integra integral form i have this + + align:start position:0% +in integra integral form i have this + + + align:start position:0% +in integra integral form i have this +integration + + align:start position:0% +integration + + + align:start position:0% +integration +so + + align:start position:0% +so + + + align:start position:0% +so +uh let's just take a look at this in + + align:start position:0% +uh let's just take a look at this in + + + align:start position:0% +uh let's just take a look at this in +this equation actually so otf is + + align:start position:0% +this equation actually so otf is + + + align:start position:0% +this equation actually so otf is +function of u + + align:start position:0% +function of u + + + align:start position:0% +function of u +but this integration i mean inside of + + align:start position:0% +but this integration i mean inside of + + + align:start position:0% +but this integration i mean inside of +this integration i have function of u + + align:start position:0% +this integration i have function of u + + + align:start position:0% +this integration i have function of u +prime + + align:start position:0% +prime + + + align:start position:0% +prime +h of u prime + + align:start position:0% +h of u prime + + + align:start position:0% +h of u prime +and h complex conjugate u prime minus u + + align:start position:0% +and h complex conjugate u prime minus u + + + align:start position:0% +and h complex conjugate u prime minus u +so i have the first function which is + + align:start position:0% +so i have the first function which is + + + align:start position:0% +so i have the first function which is +essentially same as my original function + + align:start position:0% +essentially same as my original function + + + align:start position:0% +essentially same as my original function +right + + align:start position:0% +right + + + align:start position:0% +right +or even though i change the variable u + + align:start position:0% +or even though i change the variable u + + + align:start position:0% +or even though i change the variable u +from u to u prime + + align:start position:0% +from u to u prime + + + align:start position:0% +from u to u prime +but this guy is function of u prime but + + align:start position:0% +but this guy is function of u prime but + + + align:start position:0% +but this guy is function of u prime but +you shift by u + + align:start position:0% +you shift by u + + + align:start position:0% +you shift by u +right + + align:start position:0% +right + + + align:start position:0% +right +and take the integration and this whole + + align:start position:0% +and take the integration and this whole + + + align:start position:0% +and take the integration and this whole +thing is function of u + + align:start position:0% +thing is function of u + + + align:start position:0% +thing is function of u +which means you're gonna take you're + + align:start position:0% +which means you're gonna take you're + + + align:start position:0% +which means you're gonna take you're +gonna compute this integration for every + + align:start position:0% +gonna compute this integration for every + + + align:start position:0% +gonna compute this integration for every +u + + align:start position:0% +u + + + align:start position:0% +u +and then you get otf right + + align:start position:0% +and then you get otf right + + + align:start position:0% +and then you get otf right +and this integration is basically you + + align:start position:0% +and this integration is basically you + + + align:start position:0% +and this integration is basically you +have two functions one is shifted by you + + align:start position:0% +have two functions one is shifted by you + + + align:start position:0% +have two functions one is shifted by you +and multiply them and take the + + align:start position:0% +and multiply them and take the + + + align:start position:0% +and multiply them and take the +integration + + align:start position:0% +integration + + + align:start position:0% +integration +which is + + align:start position:0% +which is + + + align:start position:0% +which is +essentially you + + align:start position:0% +essentially you + + + align:start position:0% +essentially you +compute the area of the overlapped i + + align:start position:0% +compute the area of the overlapped i + + + align:start position:0% +compute the area of the overlapped i +mean overlapped area of the true + + align:start position:0% +mean overlapped area of the true + + + align:start position:0% +mean overlapped area of the true +function right + + align:start position:0% + + + + align:start position:0% + +so graphically + + align:start position:0% +so graphically + + + align:start position:0% +so graphically +if i have the wrapped function and + + align:start position:0% +if i have the wrapped function and + + + align:start position:0% +if i have the wrapped function and +plugging in this integration i have + + align:start position:0% +plugging in this integration i have + + + align:start position:0% +plugging in this integration i have +this + + align:start position:0% +this + + + align:start position:0% +this +integration but i can imagine four + + align:start position:0% +integration but i can imagine four + + + align:start position:0% +integration but i can imagine four +different situations the first + + align:start position:0% +different situations the first + + + align:start position:0% +different situations the first +so + + align:start position:0% +so + + + align:start position:0% +so +so this first vector function is uh the + + align:start position:0% +so this first vector function is uh the + + + align:start position:0% +so this first vector function is uh the +green vector function + + align:start position:0% +green vector function + + + align:start position:0% +green vector function +and the second one which is moving is a + + align:start position:0% +and the second one which is moving is a + + + align:start position:0% +and the second one which is moving is a +green rec function + + align:start position:0% +green rec function + + + align:start position:0% +green rec function +so if they are not overlapped then i get + + align:start position:0% +so if they are not overlapped then i get + + + align:start position:0% +so if they are not overlapped then i get +simply zero right the first situation + + align:start position:0% +simply zero right the first situation + + + align:start position:0% +simply zero right the first situation +and as soon as they are overlapped and + + align:start position:0% +and as soon as they are overlapped and + + + align:start position:0% +and as soon as they are overlapped and +then the overlapped area is getting + + align:start position:0% +then the overlapped area is getting + + + align:start position:0% +then the overlapped area is getting +linearly increased right + + align:start position:0% +linearly increased right + + + align:start position:0% +linearly increased right +so i get this u plus u max until they + + align:start position:0% +so i get this u plus u max until they + + + align:start position:0% +so i get this u plus u max until they +are completely overlapped and then + + align:start position:0% +are completely overlapped and then + + + align:start position:0% +are completely overlapped and then +so this is a concentration + + align:start position:0% +so this is a concentration + + + align:start position:0% +so this is a concentration +and then + + align:start position:0% + + + + align:start position:0% + +once you move uh + + align:start position:0% +once you move uh + + + align:start position:0% +once you move uh +a little bit far then basically this + + align:start position:0% +a little bit far then basically this + + + align:start position:0% +a little bit far then basically this +overlap area is getting decreased so + + align:start position:0% +overlap area is getting decreased so + + + align:start position:0% +overlap area is getting decreased so +this is third situation which is this + + align:start position:0% +this is third situation which is this + + + align:start position:0% +this is third situation which is this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +and eventually + + align:start position:0% +and eventually + + + align:start position:0% +and eventually +they are not going to overlap so i get 0 + + align:start position:0% +they are not going to overlap so i get 0 + + + align:start position:0% +they are not going to overlap so i get 0 +again + + align:start position:0% +again + + + align:start position:0% +again +remember that this otf is function of u + + align:start position:0% +remember that this otf is function of u + + + align:start position:0% +remember that this otf is function of u +which is the amount of shift of this + + align:start position:0% +which is the amount of shift of this + + + align:start position:0% +which is the amount of shift of this +green leg function + + align:start position:0% + + + + align:start position:0% + +any question + + align:start position:0% +any question + + + align:start position:0% +any question +yeah so if you plot + + align:start position:0% +yeah so if you plot + + + align:start position:0% +yeah so if you plot +this overlapped area like i mean this + + align:start position:0% +this overlapped area like i mean this + + + align:start position:0% +this overlapped area like i mean this +guy and this guy + + align:start position:0% +guy and this guy + + + align:start position:0% +guy and this guy +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +u then actually we are going to get a + + align:start position:0% +u then actually we are going to get a + + + align:start position:0% +u then actually we are going to get a +triangular function + + align:start position:0% +triangular function + + + align:start position:0% +triangular function +which + + align:start position:0% + + + + align:start position:0% + +he it looks like + + align:start position:0% +he it looks like + + + align:start position:0% +he it looks like +this one + + align:start position:0% + + + + align:start position:0% + +and we of course we normalize at the + + align:start position:0% +and we of course we normalize at the + + + align:start position:0% +and we of course we normalize at the +zero frequency + + align:start position:0% +zero frequency + + + align:start position:0% +zero frequency +so at a zero we always have a one + + align:start position:0% +so at a zero we always have a one + + + align:start position:0% +so at a zero we always have a one +so you know you notice the difference + + align:start position:0% +so you know you notice the difference + + + align:start position:0% +so you know you notice the difference +between these two + + align:start position:0% +between these two + + + align:start position:0% +between these two +so atf + + align:start position:0% +so atf + + + align:start position:0% +so atf +my activity is nothing but my pupil + + align:start position:0% +my activity is nothing but my pupil + + + align:start position:0% +my activity is nothing but my pupil +function right just wrapped function and + + align:start position:0% +function right just wrapped function and + + + align:start position:0% +function right just wrapped function and +the color frequency u max is defined by + + align:start position:0% +the color frequency u max is defined by + + + align:start position:0% +the color frequency u max is defined by +my physical size of the pupil with the + + align:start position:0% +my physical size of the pupil with the + + + align:start position:0% +my physical size of the pupil with the +scaling factor + + align:start position:0% +scaling factor + + + align:start position:0% +scaling factor +but otf is autocorrelation so the shape + + align:start position:0% +but otf is autocorrelation so the shape + + + align:start position:0% +but otf is autocorrelation so the shape +is now + + align:start position:0% +is now + + + align:start position:0% +is now +the triangular shape but also the color + + align:start position:0% +the triangular shape but also the color + + + align:start position:0% +the triangular shape but also the color +frequency the umx is twice of the umax + + align:start position:0% +frequency the umx is twice of the umax + + + align:start position:0% +frequency the umx is twice of the umax +because you know + + align:start position:0% +because you know + + + align:start position:0% +because you know +basically you basically you + + align:start position:0% +basically you basically you + + + align:start position:0% +basically you basically you +go through all this process so + + align:start position:0% +go through all this process so + + + align:start position:0% +go through all this process so +you get twice of the color frequency + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so whatever yeah + + align:start position:0% +so whatever yeah + + + align:start position:0% +so whatever yeah +so whatever triple you have if you + + align:start position:0% +so whatever triple you have if you + + + align:start position:0% +so whatever triple you have if you +compute this kind of uh overlapped area + + align:start position:0% +compute this kind of uh overlapped area + + + align:start position:0% +compute this kind of uh overlapped area +then you can get + + align:start position:0% +then you can get + + + align:start position:0% +then you can get +otf + + align:start position:0% +otf + + + align:start position:0% +otf +so + + align:start position:0% + + + + align:start position:0% + +in convincebook if you have a + + align:start position:0% +in convincebook if you have a + + + align:start position:0% +in convincebook if you have a +rectangular scale aperture then you know + + align:start position:0% +rectangular scale aperture then you know + + + align:start position:0% +rectangular scale aperture then you know +if you go through this uh + + align:start position:0% +if you go through this uh + + + align:start position:0% +if you go through this uh +autocorrelation then you can get this + + align:start position:0% +autocorrelation then you can get this + + + align:start position:0% +autocorrelation then you can get this +kind of otf so this is just linear + + align:start position:0% +kind of otf so this is just linear + + + align:start position:0% +kind of otf so this is just linear +completely linear in + + align:start position:0% +completely linear in + + + align:start position:0% +completely linear in +u and v direction + + align:start position:0% +u and v direction + + + align:start position:0% +u and v direction +so yeah again the f x and f y they are u + + align:start position:0% +so yeah again the f x and f y they are u + + + align:start position:0% +so yeah again the f x and f y they are u +and v uh in our electron + + align:start position:0% +and v uh in our electron + + + align:start position:0% +and v uh in our electron +and if you have the circular aperture + + align:start position:0% +and if you have the circular aperture + + + align:start position:0% +and if you have the circular aperture +it's almost linear but it's slightly + + align:start position:0% +it's almost linear but it's slightly + + + align:start position:0% +it's almost linear but it's slightly +curved at the edge + + align:start position:0% + + + + align:start position:0% + +yeah but + + align:start position:0% +yeah but + + + align:start position:0% +yeah but +you know essentially base is essentially + + align:start position:0% +you know essentially base is essentially + + + align:start position:0% +you know essentially base is essentially +up + + align:start position:0% +up + + + align:start position:0% +up +same thing so if you + + align:start position:0% +same thing so if you + + + align:start position:0% +same thing so if you +move around two circles and compute the + + align:start position:0% +move around two circles and compute the + + + align:start position:0% +move around two circles and compute the +overlapped area then you will end up + + align:start position:0% +overlapped area then you will end up + + + align:start position:0% +overlapped area then you will end up +with this uh + + align:start position:0% +with this uh + + + align:start position:0% +with this uh +you'll end up with this function + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +i guess this is a good time to + + align:start position:0% +i guess this is a good time to + + + align:start position:0% +i guess this is a good time to +take a break + + align:start position:0% + + + + align:start position:0% + +all righty uh any questions so far + + align:start position:0% +all righty uh any questions so far + + + align:start position:0% +all righty uh any questions so far +so we uh so we discussed that + + align:start position:0% +so we uh so we discussed that + + + align:start position:0% +so we uh so we discussed that +so what the difference between temporal + + align:start position:0% +so what the difference between temporal + + + align:start position:0% +so what the difference between temporal +and special coherence + + align:start position:0% +and special coherence + + + align:start position:0% +and special coherence +and define the intensity point three + + align:start position:0% +and define the intensity point three + + + align:start position:0% +and define the intensity point three +function + + align:start position:0% +function + + + align:start position:0% +function +and also define the otf which is spread + + align:start position:0% +and also define the otf which is spread + + + align:start position:0% +and also define the otf which is spread +transform of the intensity point + + align:start position:0% +transform of the intensity point + + + align:start position:0% +transform of the intensity point +function and + + align:start position:0% +function and + + + align:start position:0% +function and +at the last + + align:start position:0% +at the last + + + align:start position:0% +at the last +excuse me + + align:start position:0% +excuse me + + + align:start position:0% +excuse me +otf is autocorrelation of the atf and i + + align:start position:0% +otf is autocorrelation of the atf and i + + + align:start position:0% +otf is autocorrelation of the atf and i +visually + + align:start position:0% +visually + + + align:start position:0% +visually +show that how to compute the otf + + align:start position:0% + + + + align:start position:0% + +so let's just summarize uh what we + + align:start position:0% +so let's just summarize uh what we + + + align:start position:0% +so let's just summarize uh what we +discussed so far + + align:start position:0% +discussed so far + + + align:start position:0% +discussed so far +so first + + align:start position:0% +so first + + + align:start position:0% +so first +we know and we already we all know that + + align:start position:0% +we know and we already we all know that + + + align:start position:0% +we know and we already we all know that +i mean cohen points a function is + + align:start position:0% +i mean cohen points a function is + + + align:start position:0% +i mean cohen points a function is +nothing but an optical field generated + + align:start position:0% +nothing but an optical field generated + + + align:start position:0% +nothing but an optical field generated +by a point source at the input plane + + align:start position:0% +by a point source at the input plane + + + align:start position:0% +by a point source at the input plane +right + + align:start position:0% +right + + + align:start position:0% +right +and + + align:start position:0% +and + + + align:start position:0% +and +yeah that's the + + align:start position:0% +yeah that's the + + + align:start position:0% +yeah that's the +field and by and also you know that + + align:start position:0% +field and by and also you know that + + + align:start position:0% +field and by and also you know that +point coherent points of function is + + align:start position:0% +point coherent points of function is + + + align:start position:0% +point coherent points of function is +fret transform of your perfect function + + align:start position:0% +fret transform of your perfect function + + + align:start position:0% +fret transform of your perfect function +with a + + align:start position:0% +with a + + + align:start position:0% +with a +coordinate scaling + + align:start position:0% +coordinate scaling + + + align:start position:0% +coordinate scaling +and in cohere in coherent points + + align:start position:0% +and in cohere in coherent points + + + align:start position:0% +and in cohere in coherent points +function is + + align:start position:0% +function is + + + align:start position:0% +function is +magnitude square of + + align:start position:0% +magnitude square of + + + align:start position:0% +magnitude square of +forehand point function + + align:start position:0% +forehand point function + + + align:start position:0% +forehand point function +or another way to say is + + align:start position:0% +or another way to say is + + + align:start position:0% +or another way to say is +intensity function function is intensity + + align:start position:0% +intensity function function is intensity + + + align:start position:0% +intensity function function is intensity +of the field + + align:start position:0% +of the field + + + align:start position:0% +of the field +of coherent points function + + align:start position:0% + + + + align:start position:0% + +and we define that we define the + + align:start position:0% +and we define that we define the + + + align:start position:0% +and we define that we define the +amplitude transfer function atf which is + + align:start position:0% +amplitude transfer function atf which is + + + align:start position:0% +amplitude transfer function atf which is +free transform of the + + align:start position:0% +free transform of the + + + align:start position:0% +free transform of the +coherent points function + + align:start position:0% +coherent points function + + + align:start position:0% +coherent points function +right + + align:start position:0% +right + + + align:start position:0% +right +and + + align:start position:0% +and + + + align:start position:0% +and +it is + + align:start position:0% +it is + + + align:start position:0% +it is +nothing but the pupil + + align:start position:0% +nothing but the pupil + + + align:start position:0% +nothing but the pupil +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +prepare function with the scaling factor + + align:start position:0% +prepare function with the scaling factor + + + align:start position:0% +prepare function with the scaling factor +i mean coordinate scaling + + align:start position:0% +i mean coordinate scaling + + + align:start position:0% +i mean coordinate scaling +and + + align:start position:0% + + + + align:start position:0% + +we just derived that the otf which is + + align:start position:0% +we just derived that the otf which is + + + align:start position:0% +we just derived that the otf which is +free transform of the intensity points + + align:start position:0% +free transform of the intensity points + + + align:start position:0% +free transform of the intensity points +function is actually correlate + + align:start position:0% +function is actually correlate + + + align:start position:0% +function is actually correlate +autocorrelation of the atf + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +in the rest of the lecture we will + + align:start position:0% +in the rest of the lecture we will + + + align:start position:0% +in the rest of the lecture we will +probably um we most we are going to + + align:start position:0% +probably um we most we are going to + + + align:start position:0% +probably um we most we are going to +mostly deal with the the mtf which is uh + + align:start position:0% +mostly deal with the the mtf which is uh + + + align:start position:0% +mostly deal with the the mtf which is uh +magnitude + + align:start position:0% +magnitude + + + align:start position:0% +magnitude +modulus of the mt otf actually it should + + align:start position:0% +modulus of the mt otf actually it should + + + align:start position:0% +modulus of the mt otf actually it should +be otf so mtf is the magnitude component + + align:start position:0% +be otf so mtf is the magnitude component + + + align:start position:0% +be otf so mtf is the magnitude component +of the otf + + align:start position:0% + + + + align:start position:0% + +uh in terms of + + align:start position:0% +uh in terms of + + + align:start position:0% +uh in terms of +inputed output you know we are dealing + + align:start position:0% +inputed output you know we are dealing + + + align:start position:0% +inputed output you know we are dealing +with linear system approach so + + align:start position:0% +with linear system approach so + + + align:start position:0% +with linear system approach so +if we have especially coherent + + align:start position:0% +if we have especially coherent + + + align:start position:0% +if we have especially coherent +illumination + + align:start position:0% +illumination + + + align:start position:0% +illumination +so this sub illumina is the + + align:start position:0% +so this sub illumina is the + + + align:start position:0% +so this sub illumina is the +illumination field and i have the thin + + align:start position:0% +illumination field and i have the thin + + + align:start position:0% +illumination field and i have the thin +transparency the complex transparency g + + align:start position:0% +transparency the complex transparency g + + + align:start position:0% +transparency the complex transparency g +sub t then my input field is just + + align:start position:0% +sub t then my input field is just + + + align:start position:0% +sub t then my input field is just +product of my elimination field and + + align:start position:0% +product of my elimination field and + + + align:start position:0% +product of my elimination field and +complex transparency so g sub in that's + + align:start position:0% +complex transparency so g sub in that's + + + align:start position:0% +complex transparency so g sub in that's +the input field and if i convolve with + + align:start position:0% +the input field and if i convolve with + + + align:start position:0% +the input field and if i convolve with +the coherent point function that's going + + align:start position:0% +the coherent point function that's going + + + align:start position:0% +the coherent point function that's going +to be my + + align:start position:0% +to be my + + + align:start position:0% +to be my +output field which is g sub out + + align:start position:0% +output field which is g sub out + + + align:start position:0% +output field which is g sub out +and i can think of i mean this whole + + align:start position:0% +and i can think of i mean this whole + + + align:start position:0% +and i can think of i mean this whole +thing in frequency domain right so if i + + align:start position:0% +thing in frequency domain right so if i + + + align:start position:0% +thing in frequency domain right so if i +take a transfer transform + + align:start position:0% +take a transfer transform + + + align:start position:0% +take a transfer transform +capital g in is actually free transform + + align:start position:0% +capital g in is actually free transform + + + align:start position:0% +capital g in is actually free transform +of the o + + align:start position:0% +of the o + + + align:start position:0% +of the o +of small g in which is + + align:start position:0% +of small g in which is + + + align:start position:0% +of small g in which is +a free free component of my input field + + align:start position:0% +a free free component of my input field + + + align:start position:0% +a free free component of my input field +and + + align:start position:0% +and + + + align:start position:0% +and +you know convolution is multiplication + + align:start position:0% +you know convolution is multiplication + + + align:start position:0% +you know convolution is multiplication +and frequency domain so i multiply by + + align:start position:0% +and frequency domain so i multiply by + + + align:start position:0% +and frequency domain so i multiply by +atf + + align:start position:0% +atf + + + align:start position:0% +atf +then i'm going to get + + align:start position:0% +then i'm going to get + + + align:start position:0% +then i'm going to get +g sub capital g sub r which is + + align:start position:0% +g sub capital g sub r which is + + + align:start position:0% +g sub capital g sub r which is +phase transform of my upper field + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +if i have the + + align:start position:0% +if i have the + + + align:start position:0% +if i have the +specially in chronic elimination then i + + align:start position:0% +specially in chronic elimination then i + + + align:start position:0% +specially in chronic elimination then i +deal with the intensity + + align:start position:0% +deal with the intensity + + + align:start position:0% +deal with the intensity +so + + align:start position:0% +so + + + align:start position:0% +so +i have the intensity + + align:start position:0% +i have the intensity + + + align:start position:0% +i have the intensity +of illumination and i have the still + + align:start position:0% +of illumination and i have the still + + + align:start position:0% +of illumination and i have the still +complex transparency so actually my + + align:start position:0% +complex transparency so actually my + + + align:start position:0% +complex transparency so actually my +input + + align:start position:0% +input + + + align:start position:0% +input +intensity is + + align:start position:0% +intensity is + + + align:start position:0% +intensity is +elimination intensity times + + align:start position:0% +elimination intensity times + + + align:start position:0% +elimination intensity times +magnitude square of g sub t so + + align:start position:0% +magnitude square of g sub t so + + + align:start position:0% +magnitude square of g sub t so +remember that gt is complex transparency + + align:start position:0% +remember that gt is complex transparency + + + align:start position:0% +remember that gt is complex transparency +so to make the intensity you have to + + align:start position:0% +so to make the intensity you have to + + + align:start position:0% +so to make the intensity you have to +take magnitude square so this is my + + align:start position:0% +take magnitude square so this is my + + + align:start position:0% +take magnitude square so this is my +input intensity + + align:start position:0% +input intensity + + + align:start position:0% +input intensity +and + + align:start position:0% +and + + + align:start position:0% +and +in coherent case + + align:start position:0% +in coherent case + + + align:start position:0% +in coherent case +it is linear in intensity so you have to + + align:start position:0% +it is linear in intensity so you have to + + + align:start position:0% +it is linear in intensity so you have to +convolve with the intensity point + + align:start position:0% +convolve with the intensity point + + + align:start position:0% +convolve with the intensity point +function + + align:start position:0% +function + + + align:start position:0% +function +which is + + align:start position:0% +which is + + + align:start position:0% +which is +magnitude square of the coherent point + + align:start position:0% +magnitude square of the coherent point + + + align:start position:0% +magnitude square of the coherent point +function + + align:start position:0% +function + + + align:start position:0% +function +then + + align:start position:0% +then + + + align:start position:0% +then +you're gonna get in output intensity + + align:start position:0% +you're gonna get in output intensity + + + align:start position:0% +you're gonna get in output intensity +and again in the frequency domain + + align:start position:0% +and again in the frequency domain + + + align:start position:0% +and again in the frequency domain +we can take the phase transform so g sub + + align:start position:0% +we can take the phase transform so g sub + + + align:start position:0% +we can take the phase transform so g sub +i + + align:start position:0% +i + + + align:start position:0% +i +i cannot see + + align:start position:0% +i cannot see + + + align:start position:0% +i cannot see +capital g i + + align:start position:0% +capital g i + + + align:start position:0% +capital g i +input + + align:start position:0% + + + + align:start position:0% + +capital g + + align:start position:0% +capital g + + + align:start position:0% +capital g +sub i + + align:start position:0% +sub i + + + align:start position:0% +sub i +which is uh input free transform of the + + align:start position:0% +which is uh input free transform of the + + + align:start position:0% +which is uh input free transform of the +input intensity and you're going to + + align:start position:0% +input intensity and you're going to + + + align:start position:0% +input intensity and you're going to +multiply by otf + + align:start position:0% +multiply by otf + + + align:start position:0% +multiply by otf +which is autocorrelation of the atf + + align:start position:0% +which is autocorrelation of the atf + + + align:start position:0% +which is autocorrelation of the atf +and you will get the free transform free + + align:start position:0% +and you will get the free transform free + + + align:start position:0% +and you will get the free transform free +transform of the output intensity + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so actually + + align:start position:0% +so actually + + + align:start position:0% +so actually +if you're familiar with + + align:start position:0% +if you're familiar with + + + align:start position:0% +if you're familiar with +the + + align:start position:0% +the + + + align:start position:0% +the +control theory then you probably know + + align:start position:0% +control theory then you probably know + + + align:start position:0% +control theory then you probably know +the body plot so body plot is nothing + + align:start position:0% +the body plot so body plot is nothing + + + align:start position:0% +the body plot so body plot is nothing +but you have + + align:start position:0% +but you have + + + align:start position:0% +but you have +you know in frequency domain you + + align:start position:0% +you know in frequency domain you + + + align:start position:0% +you know in frequency domain you +describe the weighting function that is + + align:start position:0% +describe the weighting function that is + + + align:start position:0% +describe the weighting function that is +going to be multiplied by your input and + + align:start position:0% +going to be multiplied by your input and + + + align:start position:0% +going to be multiplied by your input and +produce your output right so this atf + + align:start position:0% +produce your output right so this atf + + + align:start position:0% +produce your output right so this atf +and otf and also mtf they are basically + + align:start position:0% +and otf and also mtf they are basically + + + align:start position:0% +and otf and also mtf they are basically +the same thing you + + align:start position:0% +the same thing you + + + align:start position:0% +the same thing you +uh you can you multiply your + + align:start position:0% +uh you can you multiply your + + + align:start position:0% +uh you can you multiply your +uh so basically this trans uh fluid + + align:start position:0% +uh so basically this trans uh fluid + + + align:start position:0% +uh so basically this trans uh fluid +transfer function in frequency domain + + align:start position:0% +transfer function in frequency domain + + + align:start position:0% +transfer function in frequency domain +describe the weighting function that is + + align:start position:0% +describe the weighting function that is + + + align:start position:0% +describe the weighting function that is +going to be multiplied by your input and + + align:start position:0% +going to be multiplied by your input and + + + align:start position:0% +going to be multiplied by your input and +you can just you know compare the + + align:start position:0% +you can just you know compare the + + + align:start position:0% +you can just you know compare the +bit and also another way to say is the + + align:start position:0% +bit and also another way to say is the + + + align:start position:0% +bit and also another way to say is the +ratio between input and output okay + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +mtf so yeah so as i just described this + + align:start position:0% +mtf so yeah so as i just described this + + + align:start position:0% +mtf so yeah so as i just described this +frequency uh this transform transfer + + align:start position:0% +frequency uh this transform transfer + + + align:start position:0% +frequency uh this transform transfer +function is nothing but you know the + + align:start position:0% +function is nothing but you know the + + + align:start position:0% +function is nothing but you know the +weighting function in frequency domain + + align:start position:0% +weighting function in frequency domain + + + align:start position:0% +weighting function in frequency domain +frequency domain so uh let me show how + + align:start position:0% +frequency domain so uh let me show how + + + align:start position:0% +frequency domain so uh let me show how +to use it because you know if you if you + + align:start position:0% +to use it because you know if you if you + + + align:start position:0% +to use it because you know if you if you +buy or lens for your digital camera i + + align:start position:0% +buy or lens for your digital camera i + + + align:start position:0% +buy or lens for your digital camera i +mean + + align:start position:0% +mean + + + align:start position:0% +mean +typically the slr camera + + align:start position:0% +typically the slr camera + + + align:start position:0% +typically the slr camera +the lens makers provide the mtf data + + align:start position:0% +the lens makers provide the mtf data + + + align:start position:0% +the lens makers provide the mtf data +which is the weight you know this + + align:start position:0% +which is the weight you know this + + + align:start position:0% +which is the weight you know this +weighting function with the special + + align:start position:0% +weighting function with the special + + + align:start position:0% +weighting function with the special +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +and with the color frequency or i mean + + align:start position:0% +and with the color frequency or i mean + + + align:start position:0% +and with the color frequency or i mean +basically you can say what kind of image + + align:start position:0% +basically you can say what kind of image + + + align:start position:0% +basically you can say what kind of image +quality i can expect with the lens + + align:start position:0% +quality i can expect with the lens + + + align:start position:0% +quality i can expect with the lens +so first let's consider i have the + + align:start position:0% +so first let's consider i have the + + + align:start position:0% +so first let's consider i have the +gradient which + + align:start position:0% +gradient which + + + align:start position:0% +gradient which +whose amplitude transmission function is + + align:start position:0% +whose amplitude transmission function is + + + align:start position:0% +whose amplitude transmission function is +given by this equation + + align:start position:0% +given by this equation + + + align:start position:0% +given by this equation +so + + align:start position:0% +so + + + align:start position:0% +so +the input intensity is going to be + + align:start position:0% +the input intensity is going to be + + + align:start position:0% +the input intensity is going to be +you know i mean + + align:start position:0% +you know i mean + + + align:start position:0% +you know i mean +intensity of the gradient is going to be + + align:start position:0% +intensity of the gradient is going to be + + + align:start position:0% +intensity of the gradient is going to be +negative square so i have one over two + + align:start position:0% +negative square so i have one over two + + + align:start position:0% +negative square so i have one over two +then one plus m modulation and cosine + + align:start position:0% +then one plus m modulation and cosine + + + align:start position:0% +then one plus m modulation and cosine +term + + align:start position:0% +term + + + align:start position:0% +term +and the phase vector + + align:start position:0% +and the phase vector + + + align:start position:0% +and the phase vector +e to the i phi doesn't matter right + + align:start position:0% +e to the i phi doesn't matter right + + + align:start position:0% +e to the i phi doesn't matter right +because you take the negative square + + align:start position:0% +because you take the negative square + + + align:start position:0% +because you take the negative square +it's always + + align:start position:0% +it's always + + + align:start position:0% +it's always +one and + + align:start position:0% + + + + align:start position:0% + +the free transform transform free + + align:start position:0% +the free transform transform free + + + align:start position:0% +the free transform transform free +transform of this intensity + + align:start position:0% +transform of this intensity + + + align:start position:0% +transform of this intensity +input intensity is you know we all know + + align:start position:0% +input intensity is you know we all know + + + align:start position:0% +input intensity is you know we all know +that it has three uh + + align:start position:0% +that it has three uh + + + align:start position:0% +that it has three uh +three orders so so zeroth order and the + + align:start position:0% +three orders so so zeroth order and the + + + align:start position:0% +three orders so so zeroth order and the +one over capital lambda and minus one of + + align:start position:0% +one over capital lambda and minus one of + + + align:start position:0% +one over capital lambda and minus one of +the lambda we have three different + + align:start position:0% +the lambda we have three different + + + align:start position:0% +the lambda we have three different +orders + + align:start position:0% +orders + + + align:start position:0% +orders +and + + align:start position:0% +and + + + align:start position:0% +and +it's going to be multiplied by the otf + + align:start position:0% +it's going to be multiplied by the otf + + + align:start position:0% +it's going to be multiplied by the otf +which is + + align:start position:0% +which is + + + align:start position:0% +which is +at this h right + + align:start position:0% +at this h right + + + align:start position:0% +at this h right +and since this uh delta function which + + align:start position:0% +and since this uh delta function which + + + align:start position:0% +and since this uh delta function which +means this one is one only at + + align:start position:0% +means this one is one only at + + + align:start position:0% +means this one is one only at +u equals zero and on at + + align:start position:0% +u equals zero and on at + + + align:start position:0% +u equals zero and on at +u equal one over capital lambda and at + + align:start position:0% +u equal one over capital lambda and at + + + align:start position:0% +u equal one over capital lambda and at +-1 capital lambda so if you multiply the + + align:start position:0% +-1 capital lambda so if you multiply the + + + align:start position:0% +-1 capital lambda so if you multiply the +otf and actually you still have the + + align:start position:0% +otf and actually you still have the + + + align:start position:0% +otf and actually you still have the +three components + + align:start position:0% +three components + + + align:start position:0% +three components +so at zero component you have the + + align:start position:0% +so at zero component you have the + + + align:start position:0% +so at zero component you have the +otf at the zero frequency + + align:start position:0% +otf at the zero frequency + + + align:start position:0% +otf at the zero frequency +but and these two delta functions are + + align:start position:0% +but and these two delta functions are + + + align:start position:0% +but and these two delta functions are +multiplied by otf at + + align:start position:0% +multiplied by otf at + + + align:start position:0% +multiplied by otf at +the one over capital lambda and minus + + align:start position:0% +the one over capital lambda and minus + + + align:start position:0% +the one over capital lambda and minus +one over capital lambda we still have + + align:start position:0% +one over capital lambda we still have + + + align:start position:0% +one over capital lambda we still have +the uh three diffraction orders + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +and + + align:start position:0% + + + + align:start position:0% + +let me just go back + + align:start position:0% + + + + align:start position:0% + +so since this is your + + align:start position:0% +so since this is your + + + align:start position:0% +so since this is your +first transform of the output intensity + + align:start position:0% +first transform of the output intensity + + + align:start position:0% +first transform of the output intensity +so you can just take the inverse flat + + align:start position:0% +so you can just take the inverse flat + + + align:start position:0% +so you can just take the inverse flat +transform to get to it compute the + + align:start position:0% +transform to get to it compute the + + + align:start position:0% +transform to get to it compute the +output intensity right but there is + + align:start position:0% +output intensity right but there is + + + align:start position:0% +output intensity right but there is +another uh + + align:start position:0% +another uh + + + align:start position:0% +another uh +there is + + align:start position:0% +there is + + + align:start position:0% +there is +important property of the otf so this + + align:start position:0% +important property of the otf so this + + + align:start position:0% +important property of the otf so this +guy and this guy + + align:start position:0% +guy and this guy + + + align:start position:0% +guy and this guy +so + + align:start position:0% + + + + align:start position:0% + +so otf is actually + + align:start position:0% +so otf is actually + + + align:start position:0% +so otf is actually +you know intensity point function which + + align:start position:0% +you know intensity point function which + + + align:start position:0% +you know intensity point function which +is h sub i + + align:start position:0% +is h sub i + + + align:start position:0% +is h sub i +is negative square of the coherent point + + align:start position:0% +is negative square of the coherent point + + + align:start position:0% +is negative square of the coherent point +function so it is always positive + + align:start position:0% +function so it is always positive + + + align:start position:0% +function so it is always positive +i mean it's not non-negative i should + + align:start position:0% +i mean it's not non-negative i should + + + align:start position:0% +i mean it's not non-negative i should +say + + align:start position:0% +say + + + align:start position:0% +say +so it's non-negative so it's free + + align:start position:0% +so it's non-negative so it's free + + + align:start position:0% +so it's non-negative so it's free +transform is actually formation which is + + align:start position:0% +transform is actually formation which is + + + align:start position:0% +transform is actually formation which is +mathematically you can write h of minus + + align:start position:0% +mathematically you can write h of minus + + + align:start position:0% +mathematically you can write h of minus +u is actually h complex conjugate of u + + align:start position:0% +u is actually h complex conjugate of u + + + align:start position:0% +u is actually h complex conjugate of u +or you can say + + align:start position:0% +or you can say + + + align:start position:0% +or you can say +this real part is even function but this + + align:start position:0% +this real part is even function but this + + + align:start position:0% +this real part is even function but this +imaginary part is odd function + + align:start position:0% + + + + align:start position:0% + +so otf of the physically realizable + + align:start position:0% +so otf of the physically realizable + + + align:start position:0% +so otf of the physically realizable +optical system must be hermitian so most + + align:start position:0% +optical system must be hermitian so most + + + align:start position:0% +optical system must be hermitian so most +i mean this condition should be + + align:start position:0% +i mean this condition should be + + + align:start position:0% +i mean this condition should be +satisfied always + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +so in previous slide i had + + align:start position:0% +so in previous slide i had + + + align:start position:0% +so in previous slide i had +let me just + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +capital g + + align:start position:0% + + + + align:start position:0% + +i + + align:start position:0% +i + + + align:start position:0% +i +out + + align:start position:0% +out + + + align:start position:0% +out +was + + align:start position:0% +was + + + align:start position:0% +was +1 over 2 + + align:start position:0% + + + + align:start position:0% + +otf at 0 and delta u + + align:start position:0% +otf at 0 and delta u + + + align:start position:0% +otf at 0 and delta u +plus + + align:start position:0% + + + + align:start position:0% + +m over 2 + + align:start position:0% +m over 2 + + + align:start position:0% +m over 2 +h + + align:start position:0% +h + + + align:start position:0% +h +1 over capital lambda + + align:start position:0% +1 over capital lambda + + + align:start position:0% +1 over capital lambda +and delta + + align:start position:0% +and delta + + + align:start position:0% +and delta +u 1 over lambda plus + + align:start position:0% +u 1 over lambda plus + + + align:start position:0% +u 1 over lambda plus +h + + align:start position:0% +h + + + align:start position:0% +h +minus 1 lambda delta u + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +since the otf is hermitian which means + + align:start position:0% + + + + align:start position:0% + +my + + align:start position:0% +my + + + align:start position:0% +my +i mean at otf over + + align:start position:0% +i mean at otf over + + + align:start position:0% +i mean at otf over +minus one over capital lambda is + + align:start position:0% +minus one over capital lambda is + + + align:start position:0% +minus one over capital lambda is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +a complex conjugate of h + + align:start position:0% +a complex conjugate of h + + + align:start position:0% +a complex conjugate of h +one over capital lambda + + align:start position:0% + + + + align:start position:0% + +this hermitian + + align:start position:0% + + + + align:start position:0% + +so g out i mean the capital g + + align:start position:0% + + + + align:start position:0% + +i out + + align:start position:0% +i out + + + align:start position:0% +i out +i can write as + + align:start position:0% +i can write as + + + align:start position:0% +i can write as +1 over 2 + + align:start position:0% + + + + align:start position:0% + +otf at 0 still delta function + + align:start position:0% +otf at 0 still delta function + + + align:start position:0% +otf at 0 still delta function +and + + align:start position:0% +and + + + align:start position:0% +and +m over 2 + + align:start position:0% +m over 2 + + + align:start position:0% +m over 2 +h 1 over capital lambda delta u 1 over + + align:start position:0% +h 1 over capital lambda delta u 1 over + + + align:start position:0% +h 1 over capital lambda delta u 1 over +capital lambda + + align:start position:0% +capital lambda + + + align:start position:0% +capital lambda +but the last delta function i can write + + align:start position:0% +but the last delta function i can write + + + align:start position:0% +but the last delta function i can write +is + + align:start position:0% +is + + + align:start position:0% +is +h complex conjugate + + align:start position:0% +h complex conjugate + + + align:start position:0% +h complex conjugate +one over capital lambda + + align:start position:0% +one over capital lambda + + + align:start position:0% +one over capital lambda +delta + + align:start position:0% +delta + + + align:start position:0% +delta +u + + align:start position:0% +u + + + align:start position:0% +u +plus omega lambda + + align:start position:0% + + + + align:start position:0% + +so the first data function i mean if you + + align:start position:0% +so the first data function i mean if you + + + align:start position:0% +so the first data function i mean if you +take the inverse phase transform or free + + align:start position:0% +take the inverse phase transform or free + + + align:start position:0% +take the inverse phase transform or free +transform the first data function you + + align:start position:0% +transform the first data function you + + + align:start position:0% +transform the first data function you +know it just generated this term right + + align:start position:0% +know it just generated this term right + + + align:start position:0% +know it just generated this term right +just one or something so it's pretty + + align:start position:0% +just one or something so it's pretty + + + align:start position:0% +just one or something so it's pretty +straightforward the question is still + + align:start position:0% +straightforward the question is still + + + align:start position:0% +straightforward the question is still +what happened + + align:start position:0% +what happened + + + align:start position:0% +what happened +in the + + align:start position:0% +in the + + + align:start position:0% +in the +these two data functions because this + + align:start position:0% +these two data functions because this + + + align:start position:0% +these two data functions because this +one has + + align:start position:0% +one has + + + align:start position:0% +one has +you know + + align:start position:0% +you know + + + align:start position:0% +you know +h of one i mean the otf at capital one + + align:start position:0% +h of one i mean the otf at capital one + + + align:start position:0% +h of one i mean the otf at capital one +over capital lambda and + + align:start position:0% +over capital lambda and + + + align:start position:0% +over capital lambda and +the other one is actually complex + + align:start position:0% +the other one is actually complex + + + align:start position:0% +the other one is actually complex +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +so + + align:start position:0% +so + + + align:start position:0% +so +if i just write + + align:start position:0% +if i just write + + + align:start position:0% +if i just write +this the two delta function part + + align:start position:0% +this the two delta function part + + + align:start position:0% +this the two delta function part +then and i'm going to take the inverse + + align:start position:0% +then and i'm going to take the inverse + + + align:start position:0% +then and i'm going to take the inverse +spread transform so + + align:start position:0% +spread transform so + + + align:start position:0% +spread transform so +inverse fluid transform + + align:start position:0% +inverse fluid transform + + + align:start position:0% +inverse fluid transform +of + + align:start position:0% +of + + + align:start position:0% +of +m over 2 + + align:start position:0% + + + + align:start position:0% + +capital lambda + + align:start position:0% +capital lambda + + + align:start position:0% +capital lambda +delta u 1 over lambda plus + + align:start position:0% +delta u 1 over lambda plus + + + align:start position:0% +delta u 1 over lambda plus +h complex conjugate capital lambda delta + + align:start position:0% +h complex conjugate capital lambda delta + + + align:start position:0% +h complex conjugate capital lambda delta +u plus 1 over capital lambda + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +what is + + align:start position:0% +what is + + + align:start position:0% +what is +inverse frequency of the delta function + + align:start position:0% +inverse frequency of the delta function + + + align:start position:0% +inverse frequency of the delta function +is going to be exponential right so + + align:start position:0% +is going to be exponential right so + + + align:start position:0% +is going to be exponential right so +mr2 is just scalar so it's just outside + + align:start position:0% +mr2 is just scalar so it's just outside + + + align:start position:0% +mr2 is just scalar so it's just outside +and i'm going to have + + align:start position:0% +and i'm going to have + + + align:start position:0% +and i'm going to have +h of + + align:start position:0% +h of + + + align:start position:0% +h of +1 over capital lambda + + align:start position:0% +1 over capital lambda + + + align:start position:0% +1 over capital lambda +and exponent e to the + + align:start position:0% +and exponent e to the + + + align:start position:0% +and exponent e to the +i 2 pi + + align:start position:0% +i 2 pi + + + align:start position:0% +i 2 pi +x over capital lambda + + align:start position:0% +x over capital lambda + + + align:start position:0% +x over capital lambda +plus + + align:start position:0% +plus + + + align:start position:0% +plus +h complex conjugate + + align:start position:0% +h complex conjugate + + + align:start position:0% +h complex conjugate +1 over capital lambda e to the minus i + + align:start position:0% +1 over capital lambda e to the minus i + + + align:start position:0% +1 over capital lambda e to the minus i +2 pi + + align:start position:0% +2 pi + + + align:start position:0% +2 pi +x of capital lambda + + align:start position:0% + + + + align:start position:0% + +and i can write + + align:start position:0% +and i can write + + + align:start position:0% +and i can write +as + + align:start position:0% + + + + align:start position:0% + +capital + + align:start position:0% +capital + + + align:start position:0% +capital +lambda + + align:start position:0% +lambda + + + align:start position:0% +lambda +lambda e to the i 2 pi + + align:start position:0% +lambda e to the i 2 pi + + + align:start position:0% +lambda e to the i 2 pi +x over lambda + + align:start position:0% +x over lambda + + + align:start position:0% +x over lambda +plus + + align:start position:0% +plus + + + align:start position:0% +plus +actually same thing + + align:start position:0% +actually same thing + + + align:start position:0% +actually same thing +h 1 over capital lambda e to the i 2 pi + + align:start position:0% +h 1 over capital lambda e to the i 2 pi + + + align:start position:0% +h 1 over capital lambda e to the i 2 pi +x over lambda + + align:start position:0% +x over lambda + + + align:start position:0% +x over lambda +and complex + + align:start position:0% +and complex + + + align:start position:0% +and complex +conjugate like this + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +so what is the + + align:start position:0% +so what is the + + + align:start position:0% +so what is the +what happen if you add + + align:start position:0% +what happen if you add + + + align:start position:0% +what happen if you add +a + + align:start position:0% +a + + + align:start position:0% +a +and it's complex conjugate so for + + align:start position:0% +and it's complex conjugate so for + + + align:start position:0% +and it's complex conjugate so for +example this is a and this is a complex + + align:start position:0% +example this is a and this is a complex + + + align:start position:0% +example this is a and this is a complex +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +and if you add them together then + + align:start position:0% +and if you add them together then + + + align:start position:0% +and if you add them together then +you get only real part right because you + + align:start position:0% +you get only real part right because you + + + align:start position:0% +you get only real part right because you +know + + align:start position:0% +know + + + align:start position:0% +know +two + + align:start position:0% +two + + + align:start position:0% +two +real part of a + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so i'm gonna have + + align:start position:0% +so i'm gonna have + + + align:start position:0% +so i'm gonna have +m + + align:start position:0% +m + + + align:start position:0% +m +the real part of + + align:start position:0% + + + + align:start position:0% + +otf at capital one over capital lambda + + align:start position:0% +otf at capital one over capital lambda + + + align:start position:0% +otf at capital one over capital lambda +e to the + + align:start position:0% +e to the + + + align:start position:0% +e to the +i two pi x over lambda + + align:start position:0% + + + + align:start position:0% + +which i can write as m + + align:start position:0% + + + + align:start position:0% + +and bring it to the this magnitude is + + align:start position:0% +and bring it to the this magnitude is + + + align:start position:0% +and bring it to the this magnitude is +you know this h is just non-zero so it + + align:start position:0% +you know this h is just non-zero so it + + + align:start position:0% +you know this h is just non-zero so it +only it it could have i mean it + + align:start position:0% +only it it could have i mean it + + + align:start position:0% +only it it could have i mean it +you can have + + align:start position:0% +you can have + + + align:start position:0% +you can have +only + + align:start position:0% +only + + + align:start position:0% +only +zero or minus basically so i can write + + align:start position:0% +zero or minus basically so i can write + + + align:start position:0% +zero or minus basically so i can write +as a magnitude here and this will be + + align:start position:0% +as a magnitude here and this will be + + + align:start position:0% +as a magnitude here and this will be +cosine + + align:start position:0% +cosine + + + align:start position:0% +cosine +2 pi + + align:start position:0% +2 pi + + + align:start position:0% +2 pi +x over lambda + + align:start position:0% + + + + align:start position:0% + +so that's why + + align:start position:0% +so that's why + + + align:start position:0% +so that's why +my g is i mean the output intensity is + + align:start position:0% +my g is i mean the output intensity is + + + align:start position:0% +my g is i mean the output intensity is +just one plus + + align:start position:0% +just one plus + + + align:start position:0% +just one plus +m which is original modulation + + align:start position:0% +m which is original modulation + + + align:start position:0% +m which is original modulation +but i have extra modulation due to otf + + align:start position:0% +but i have extra modulation due to otf + + + align:start position:0% +but i have extra modulation due to otf +and cosine + + align:start position:0% + + + + align:start position:0% + +should i prove why otf is formation + + align:start position:0% +should i prove why otf is formation + + + align:start position:0% +should i prove why otf is formation +actually + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +yeah let me prove why otf is hormone + + align:start position:0% + + + + align:start position:0% + +so otf + + align:start position:0% +so otf + + + align:start position:0% +so otf +is autocorrelation of atf which is + + align:start position:0% +is autocorrelation of atf which is + + + align:start position:0% +is autocorrelation of atf which is +like this + + align:start position:0% + + + + align:start position:0% + +and integration + + align:start position:0% +and integration + + + align:start position:0% +and integration +with the integral form i can write as + + align:start position:0% +with the integral form i can write as + + + align:start position:0% +with the integral form i can write as +h of + + align:start position:0% +h of + + + align:start position:0% +h of +u prime + + align:start position:0% +u prime + + + align:start position:0% +u prime +h + + align:start position:0% +h + + + align:start position:0% +h +complex conjugate + + align:start position:0% +complex conjugate + + + align:start position:0% +complex conjugate +u prime minus u + + align:start position:0% +u prime minus u + + + align:start position:0% +u prime minus u +and v u prime + + align:start position:0% + + + + align:start position:0% + +and i want to compute + + align:start position:0% +and i want to compute + + + align:start position:0% +and i want to compute +h + + align:start position:0% +h + + + align:start position:0% +h +i mean otf + + align:start position:0% +i mean otf + + + align:start position:0% +i mean otf +and complex conjugate of u + + align:start position:0% +and complex conjugate of u + + + align:start position:0% +and complex conjugate of u +so i can write as uh + + align:start position:0% +so i can write as uh + + + align:start position:0% +so i can write as uh +the total thing + + align:start position:0% +the total thing + + + align:start position:0% +the total thing +h of u prime + + align:start position:0% +h of u prime + + + align:start position:0% +h of u prime +x h complex conjugate u prime u + + align:start position:0% +x h complex conjugate u prime u + + + align:start position:0% +x h complex conjugate u prime u +d u u prime + + align:start position:0% +d u u prime + + + align:start position:0% +d u u prime +and complex + + align:start position:0% +and complex + + + align:start position:0% +and complex +excuse me yes uh we're not able to see + + align:start position:0% +excuse me yes uh we're not able to see + + + align:start position:0% +excuse me yes uh we're not able to see +what you are writing means uh + + align:start position:0% + + + + align:start position:0% + +oh okay now okay + + align:start position:0% + + + + align:start position:0% + +yeah so i just take the complex + + align:start position:0% +yeah so i just take the complex + + + align:start position:0% +yeah so i just take the complex +conjugate on both sides okay + + align:start position:0% +conjugate on both sides okay + + + align:start position:0% +conjugate on both sides okay +and + + align:start position:0% +and + + + align:start position:0% +and +i can change the complex conjugate + + align:start position:0% +i can change the complex conjugate + + + align:start position:0% +i can change the complex conjugate +so it's gonna be + + align:start position:0% +so it's gonna be + + + align:start position:0% +so it's gonna be +h complex conjugate over u prime + + align:start position:0% +h complex conjugate over u prime + + + align:start position:0% +h complex conjugate over u prime +h and u prime and u + + align:start position:0% +h and u prime and u + + + align:start position:0% +h and u prime and u +and d u prime + + align:start position:0% +and d u prime + + + align:start position:0% +and d u prime +so i just replied i mean just put the + + align:start position:0% +so i just replied i mean just put the + + + align:start position:0% +so i just replied i mean just put the +complex conjugate inside of the + + align:start position:0% +complex conjugate inside of the + + + align:start position:0% +complex conjugate inside of the +integration + + align:start position:0% +integration + + + align:start position:0% +integration +and here i define the new variable so + + align:start position:0% +and here i define the new variable so + + + align:start position:0% +and here i define the new variable so +u double prime is + + align:start position:0% +u double prime is + + + align:start position:0% +u double prime is +u prime minus u + + align:start position:0% +u prime minus u + + + align:start position:0% +u prime minus u +so + + align:start position:0% + + + + align:start position:0% + +u prime + + align:start position:0% +u prime + + + align:start position:0% +u prime +is u plus u double prime + + align:start position:0% +is u plus u double prime + + + align:start position:0% +is u plus u double prime +and + + align:start position:0% +and + + + align:start position:0% +and +d u prime is actually d u double prime + + align:start position:0% + + + + align:start position:0% + +so this + + align:start position:0% +so this + + + align:start position:0% +so this +h complex conjugate is + + align:start position:0% +h complex conjugate is + + + align:start position:0% +h complex conjugate is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +h + + align:start position:0% + + + + align:start position:0% + +h complex conjugate + + align:start position:0% +h complex conjugate + + + align:start position:0% +h complex conjugate +u plus u double prime + + align:start position:0% +u plus u double prime + + + align:start position:0% +u plus u double prime +h of u double prime + + align:start position:0% +h of u double prime + + + align:start position:0% +h of u double prime +and d u double prime + + align:start position:0% +and d u double prime + + + align:start position:0% +and d u double prime +which i can write as + + align:start position:0% +which i can write as + + + align:start position:0% +which i can write as +integration + + align:start position:0% +integration + + + align:start position:0% +integration +h + + align:start position:0% +h + + + align:start position:0% +h +u double prime + + align:start position:0% +u double prime + + + align:start position:0% +u double prime +x + + align:start position:0% +x + + + align:start position:0% +x +complex conjugate + + align:start position:0% +complex conjugate + + + align:start position:0% +complex conjugate +u double prime + + align:start position:0% +u double prime + + + align:start position:0% +u double prime +minus + + align:start position:0% +minus + + + align:start position:0% +minus +minus u + + align:start position:0% +minus u + + + align:start position:0% +minus u +d u double prime so is + + align:start position:0% +d u double prime so is + + + align:start position:0% +d u double prime so is +h of + + align:start position:0% +h of + + + align:start position:0% +h of +minus u + + align:start position:0% + + + + align:start position:0% + +so this is + + align:start position:0% + + + + align:start position:0% + +complex conjugate + + align:start position:0% + + + + align:start position:0% + +permission + + align:start position:0% + + + + align:start position:0% + +yeah i just proved + + align:start position:0% +yeah i just proved + + + align:start position:0% +yeah i just proved +you know you can easily do that so the + + align:start position:0% +you know you can easily do that so the + + + align:start position:0% +you know you can easily do that so the +bottom line is + + align:start position:0% +bottom line is + + + align:start position:0% +bottom line is +uh at the output plane i mean output + + align:start position:0% +uh at the output plane i mean output + + + align:start position:0% +uh at the output plane i mean output +intensity i have extra modulation uh + + align:start position:0% +intensity i have extra modulation uh + + + align:start position:0% +intensity i have extra modulation uh +coming from the otf i mean you can say + + align:start position:0% +coming from the otf i mean you can say + + + align:start position:0% +coming from the otf i mean you can say +this is magnitude so you can say it's + + align:start position:0% +this is magnitude so you can say it's + + + align:start position:0% +this is magnitude so you can say it's +mtf + + align:start position:0% +mtf + + + align:start position:0% +mtf +right + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +if you compare in terms of the + + align:start position:0% +if you compare in terms of the + + + align:start position:0% +if you compare in terms of the +contrast or visibility so the contract + + align:start position:0% +contrast or visibility so the contract + + + align:start position:0% +contrast or visibility so the contract +is defined by + + align:start position:0% +is defined by + + + align:start position:0% +is defined by +imx minus i min over i max plus i mean + + align:start position:0% +imx minus i min over i max plus i mean + + + align:start position:0% +imx minus i min over i max plus i mean +but at the output plane uh we have the + + align:start position:0% +but at the output plane uh we have the + + + align:start position:0% +but at the output plane uh we have the +extra uh modulation term so if you + + align:start position:0% +extra uh modulation term so if you + + + align:start position:0% +extra uh modulation term so if you +compute the same thing then actually + + align:start position:0% +compute the same thing then actually + + + align:start position:0% +compute the same thing then actually +your contract is going to be on the + + align:start position:0% +your contract is going to be on the + + + align:start position:0% +your contract is going to be on the +original modulation multiplied by + + align:start position:0% +original modulation multiplied by + + + align:start position:0% +original modulation multiplied by +mtf at the + + align:start position:0% +mtf at the + + + align:start position:0% +mtf at the +that spatial frequency + + align:start position:0% + + + + align:start position:0% + +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +yeah mtf is just contrast at the special + + align:start position:0% +yeah mtf is just contrast at the special + + + align:start position:0% +yeah mtf is just contrast at the special +frequency and relative to the + + align:start position:0% +frequency and relative to the + + + align:start position:0% +frequency and relative to the +transmission to the discussion + + align:start position:0% +transmission to the discussion + + + align:start position:0% +transmission to the discussion +so what does it mean + + align:start position:0% +so what does it mean + + + align:start position:0% +so what does it mean +so for example i have + + align:start position:0% +so for example i have + + + align:start position:0% +so for example i have +mtf + + align:start position:0% +mtf + + + align:start position:0% +mtf +looks like this + + align:start position:0% +looks like this + + + align:start position:0% +looks like this +i initially had the grading + + align:start position:0% +i initially had the grading + + + align:start position:0% +i initially had the grading +intensity of the grading is actually one + + align:start position:0% +intensity of the grading is actually one + + + align:start position:0% +intensity of the grading is actually one +over two one plus m cosine two pi x over + + align:start position:0% +over two one plus m cosine two pi x over + + + align:start position:0% +over two one plus m cosine two pi x over +capital lambda so if i draw in greyscale + + align:start position:0% +capital lambda so if i draw in greyscale + + + align:start position:0% +capital lambda so if i draw in greyscale +so the white is one and black is zero + + align:start position:0% +so the white is one and black is zero + + + align:start position:0% +so the white is one and black is zero +right so i have nice sinusoid with the + + align:start position:0% +right so i have nice sinusoid with the + + + align:start position:0% +right so i have nice sinusoid with the +full contrast like this + + align:start position:0% +full contrast like this + + + align:start position:0% +full contrast like this +but + + align:start position:0% +but + + + align:start position:0% +but +the output intensity i'm going to have + + align:start position:0% +the output intensity i'm going to have + + + align:start position:0% +the output intensity i'm going to have +one plus m + + align:start position:0% +one plus m + + + align:start position:0% +one plus m +and additional modulation and cosine + + align:start position:0% +and additional modulation and cosine + + + align:start position:0% +and additional modulation and cosine +term so + + align:start position:0% +term so + + + align:start position:0% +term so +and + + align:start position:0% +and + + + align:start position:0% +and +this factor you can find at the graph + + align:start position:0% +this factor you can find at the graph + + + align:start position:0% +this factor you can find at the graph +right so if you have the vulnerable log + + align:start position:0% +right so if you have the vulnerable log + + + align:start position:0% +right so if you have the vulnerable log +capital lambda then you can find the the + + align:start position:0% +capital lambda then you can find the the + + + align:start position:0% +capital lambda then you can find the the +value at that + + align:start position:0% +value at that + + + align:start position:0% +value at that +point right i mean mtf at that point + + align:start position:0% +point right i mean mtf at that point + + + align:start position:0% +point right i mean mtf at that point +this point so if that value is 0.6 + + align:start position:0% +this point so if that value is 0.6 + + + align:start position:0% +this point so if that value is 0.6 +in this case so this + + align:start position:0% +in this case so this + + + align:start position:0% +in this case so this +sine so the pattern + + align:start position:0% +sine so the pattern + + + align:start position:0% +sine so the pattern +will look like this + + align:start position:0% +will look like this + + + align:start position:0% +will look like this +but if the modulation is 0.2 then + + align:start position:0% +but if the modulation is 0.2 then + + + align:start position:0% +but if the modulation is 0.2 then +you know the black become uh brighter + + align:start position:0% +you know the black become uh brighter + + + align:start position:0% +you know the black become uh brighter +and white become darker so you kind of + + align:start position:0% +and white become darker so you kind of + + + align:start position:0% +and white become darker so you kind of +get + + align:start position:0% +get + + + align:start position:0% +get +the gray scale + + align:start position:0% +the gray scale + + + align:start position:0% +the gray scale +the broad version of the grading like + + align:start position:0% +the broad version of the grading like + + + align:start position:0% +the broad version of the grading like +this + + align:start position:0% +this + + + align:start position:0% +this +so basically this mtf tells you that + + align:start position:0% +so basically this mtf tells you that + + + align:start position:0% +so basically this mtf tells you that +what kind of + + align:start position:0% +what kind of + + + align:start position:0% +what kind of +contrast i expect with that + + align:start position:0% +contrast i expect with that + + + align:start position:0% +contrast i expect with that +i mean at this particular special + + align:start position:0% +i mean at this particular special + + + align:start position:0% +i mean at this particular special +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +and also + + align:start position:0% +and also + + + align:start position:0% +and also +it specifies the maximum special + + align:start position:0% +it specifies the maximum special + + + align:start position:0% +it specifies the maximum special +frequency you can resolve i mean you can + + align:start position:0% +frequency you can resolve i mean you can + + + align:start position:0% +frequency you can resolve i mean you can +see + + align:start position:0% + + + + align:start position:0% + +any questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so far we just deal with the ideal + + align:start position:0% +so so far we just deal with the ideal + + + align:start position:0% +so so far we just deal with the ideal +thin length with the clear aperture like + + align:start position:0% +thin length with the clear aperture like + + + align:start position:0% +thin length with the clear aperture like +the rectangular aperture circular + + align:start position:0% +the rectangular aperture circular + + + align:start position:0% +the rectangular aperture circular +aperture + + align:start position:0% +aperture + + + align:start position:0% +aperture +so in the case of rectangular aperture + + align:start position:0% +so in the case of rectangular aperture + + + align:start position:0% +so in the case of rectangular aperture +we know that the otf is just + + align:start position:0% +we know that the otf is just + + + align:start position:0% +we know that the otf is just +autocorrelation of the two red function + + align:start position:0% +autocorrelation of the two red function + + + align:start position:0% +autocorrelation of the two red function +which is it's just triangular function + + align:start position:0% +which is it's just triangular function + + + align:start position:0% +which is it's just triangular function +so it's + + align:start position:0% +so it's + + + align:start position:0% +so it's +just linear from one to uh color + + align:start position:0% +just linear from one to uh color + + + align:start position:0% +just linear from one to uh color +frequency which is twice of the outer + + align:start position:0% +frequency which is twice of the outer + + + align:start position:0% +frequency which is twice of the outer +frequency at otf + + align:start position:0% +frequency at otf + + + align:start position:0% +frequency at otf +no the atf + + align:start position:0% +no the atf + + + align:start position:0% +no the atf +and if you have the circular aperture + + align:start position:0% +and if you have the circular aperture + + + align:start position:0% +and if you have the circular aperture +it's almost linear except at the + + align:start position:0% +it's almost linear except at the + + + align:start position:0% +it's almost linear except at the +edge region you slide you have slightly + + align:start position:0% +edge region you slide you have slightly + + + align:start position:0% +edge region you slide you have slightly +curved + + align:start position:0% +curved + + + align:start position:0% +curved +line + + align:start position:0% +line + + + align:start position:0% +line +but you know basically same thing so + + align:start position:0% +but you know basically same thing so + + + align:start position:0% +but you know basically same thing so +this blue line + + align:start position:0% +this blue line + + + align:start position:0% +this blue line +and the black line we call uh diffracted + + align:start position:0% +and the black line we call uh diffracted + + + align:start position:0% +and the black line we call uh diffracted +uh deflection limited otf + + align:start position:0% +uh deflection limited otf + + + align:start position:0% +uh deflection limited otf +because we assume the ideal a thin lens + + align:start position:0% +because we assume the ideal a thin lens + + + align:start position:0% +because we assume the ideal a thin lens +without any aberration so this is kind + + align:start position:0% +without any aberration so this is kind + + + align:start position:0% +without any aberration so this is kind +of + + align:start position:0% +of + + + align:start position:0% +of +a maximum otf i mean best rtf you can + + align:start position:0% +a maximum otf i mean best rtf you can + + + align:start position:0% +a maximum otf i mean best rtf you can +achieve + + align:start position:0% +achieve + + + align:start position:0% +achieve +but you know in practice you always have + + align:start position:0% +but you know in practice you always have + + + align:start position:0% +but you know in practice you always have +aeration right i mean chromatic + + align:start position:0% +aeration right i mean chromatic + + + align:start position:0% +aeration right i mean chromatic +aberration or any higher vibration or + + align:start position:0% +aberration or any higher vibration or + + + align:start position:0% +aberration or any higher vibration or +you know you can't have the difficult or + + align:start position:0% +you know you can't have the difficult or + + + align:start position:0% +you know you can't have the difficult or +some + + align:start position:0% +some + + + align:start position:0% +some +imperfect uh factor in length so + + align:start position:0% +imperfect uh factor in length so + + + align:start position:0% +imperfect uh factor in length so +typically + + align:start position:0% +typically + + + align:start position:0% +typically +typical lens has this kind of + + align:start position:0% +typical lens has this kind of + + + align:start position:0% +typical lens has this kind of +distorted or degraded otf like this the + + align:start position:0% +distorted or degraded otf like this the + + + align:start position:0% +distorted or degraded otf like this the +red one like here or here + + align:start position:0% + + + + align:start position:0% + +so you know in terms of of this + + align:start position:0% +so you know in terms of of this + + + align:start position:0% +so you know in terms of of this +deflection limit you want to buy your + + align:start position:0% +deflection limit you want to buy your + + + align:start position:0% +deflection limit you want to buy your +lens that + + align:start position:0% +lens that + + + align:start position:0% +lens that +otf is similar to this blue line because + + align:start position:0% +otf is similar to this blue line because + + + align:start position:0% +otf is similar to this blue line because +you know this is deflection limited + + align:start position:0% +you know this is deflection limited + + + align:start position:0% +you know this is deflection limited +which means the best + + align:start position:0% +which means the best + + + align:start position:0% +which means the best +otf we can achieve + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +yeah so i described i mean this is this + + align:start position:0% +yeah so i described i mean this is this + + + align:start position:0% +yeah so i described i mean this is this +uh slope is linear and + + align:start position:0% +uh slope is linear and + + + align:start position:0% +uh slope is linear and +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah circular aperture and + + align:start position:0% +yeah circular aperture and + + + align:start position:0% +yeah circular aperture and +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +i mean locally it can have a higher + + align:start position:0% +i mean locally it can have a higher + + + align:start position:0% +i mean locally it can have a higher +value but you know overall + + align:start position:0% +value but you know overall + + + align:start position:0% +value but you know overall +the overall shape should be smaller than + + align:start position:0% +the overall shape should be smaller than + + + align:start position:0% +the overall shape should be smaller than +this blue line + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +uh let's just apply the all this concept + + align:start position:0% +uh let's just apply the all this concept + + + align:start position:0% +uh let's just apply the all this concept +in you know the in real voice system + + align:start position:0% +in you know the in real voice system + + + align:start position:0% +in you know the in real voice system +so we have first system was focal length + + align:start position:0% +so we have first system was focal length + + + align:start position:0% +so we have first system was focal length +iphone f2 again + + align:start position:0% +iphone f2 again + + + align:start position:0% +iphone f2 again +and i put a input transparency which is + + align:start position:0% +and i put a input transparency which is + + + align:start position:0% +and i put a input transparency which is +a binary amplitude grading right here + + align:start position:0% +a binary amplitude grading right here + + + align:start position:0% +a binary amplitude grading right here +and illuminate with a + + align:start position:0% +and illuminate with a + + + align:start position:0% +and illuminate with a +quasi-monochromatic + + align:start position:0% +quasi-monochromatic + + + align:start position:0% +quasi-monochromatic +which is from a single color and + + align:start position:0% +which is from a single color and + + + align:start position:0% +which is from a single color and +especially in current illumination + + align:start position:0% +especially in current illumination + + + align:start position:0% +especially in current illumination +and uniform intensity typically we + + align:start position:0% +and uniform intensity typically we + + + align:start position:0% +and uniform intensity typically we +assume the intensity variation is + + align:start position:0% +assume the intensity variation is + + + align:start position:0% +assume the intensity variation is +uniform + + align:start position:0% +uniform + + + align:start position:0% +uniform +so + + align:start position:0% +so + + + align:start position:0% +so +well + + align:start position:0% +well + + + align:start position:0% +well +the possible question is what kind of + + align:start position:0% +the possible question is what kind of + + + align:start position:0% +the possible question is what kind of +image we can expect at the image plane + + align:start position:0% +image we can expect at the image plane + + + align:start position:0% +image we can expect at the image plane +or you know what is the + + align:start position:0% +or you know what is the + + + align:start position:0% +or you know what is the +otf or + + align:start position:0% +otf or + + + align:start position:0% +otf or +yeah what is atf and otf and blah blah + + align:start position:0% +yeah what is atf and otf and blah blah + + + align:start position:0% +yeah what is atf and otf and blah blah +blah so let's go through it + + align:start position:0% + + + + align:start position:0% + +okay so this is the binary amplitude + + align:start position:0% +okay so this is the binary amplitude + + + align:start position:0% +okay so this is the binary amplitude +grading so it is + + align:start position:0% +grading so it is + + + align:start position:0% +grading so it is +still complex transparency + + align:start position:0% +still complex transparency + + + align:start position:0% +still complex transparency +in field so + + align:start position:0% +in field so + + + align:start position:0% +in field so +you know if you have in uh in current + + align:start position:0% +you know if you have in uh in current + + + align:start position:0% +you know if you have in uh in current +elimination you want to compute the + + align:start position:0% +elimination you want to compute the + + + align:start position:0% +elimination you want to compute the +intensity so you have to take the + + align:start position:0% +intensity so you have to take the + + + align:start position:0% +intensity so you have to take the +magnitude square but this is just 0 or 1 + + align:start position:0% +magnitude square but this is just 0 or 1 + + + align:start position:0% +magnitude square but this is just 0 or 1 +so basically you have the same thing in + + align:start position:0% +so basically you have the same thing in + + + align:start position:0% +so basically you have the same thing in +intensity right + + align:start position:0% +intensity right + + + align:start position:0% +intensity right +so that's the input intensity the upper + + align:start position:0% +so that's the input intensity the upper + + + align:start position:0% +so that's the input intensity the upper +right + + align:start position:0% +right + + + align:start position:0% +right +and this is the + + align:start position:0% +and this is the + + + align:start position:0% +and this is the +face mask located at the free plane + + align:start position:0% +face mask located at the free plane + + + align:start position:0% +face mask located at the free plane +and we know that the atf is + + align:start position:0% +and we know that the atf is + + + align:start position:0% +and we know that the atf is +basically the same function with + + align:start position:0% +basically the same function with + + + align:start position:0% +basically the same function with +different uh + + align:start position:0% + + + + align:start position:0% + +different coordinates right + + align:start position:0% +different coordinates right + + + align:start position:0% +different coordinates right +so + + align:start position:0% +so + + + align:start position:0% +so +atf is face mask + + align:start position:0% +atf is face mask + + + align:start position:0% +atf is face mask +but the function is the x double prime i + + align:start position:0% +but the function is the x double prime i + + + align:start position:0% +but the function is the x double prime i +mean you have this coordinate scaling + + align:start position:0% +mean you have this coordinate scaling + + + align:start position:0% +mean you have this coordinate scaling +factor + + align:start position:0% + + + + align:start position:0% + +so if you + + align:start position:0% +so if you + + + align:start position:0% +so if you +compute the otf from this a-tip + + align:start position:0% +compute the otf from this a-tip + + + align:start position:0% +compute the otf from this a-tip +basically what you do is you have two uh + + align:start position:0% +basically what you do is you have two uh + + + align:start position:0% +basically what you do is you have two uh +you have two that two-rect function + + align:start position:0% +you have two that two-rect function + + + align:start position:0% +you have two that two-rect function +actually you have so you you're gonna + + align:start position:0% +actually you have so you you're gonna + + + align:start position:0% +actually you have so you you're gonna +have actually four vector functions + + align:start position:0% +have actually four vector functions + + + align:start position:0% +have actually four vector functions +right and you move one uh two of them + + align:start position:0% +right and you move one uh two of them + + + align:start position:0% +right and you move one uh two of them +so whenever they overlap you get some uh + + align:start position:0% +so whenever they overlap you get some uh + + + align:start position:0% +so whenever they overlap you get some uh +value right + + align:start position:0% +value right + + + align:start position:0% +value right +so if you do uh that autocorrelation + + align:start position:0% +so if you do uh that autocorrelation + + + align:start position:0% +so if you do uh that autocorrelation +then actually + + align:start position:0% +then actually + + + align:start position:0% +then actually +you're going to have + + align:start position:0% +you're going to have + + + align:start position:0% +you're going to have +three triangular so remember that if you + + align:start position:0% +three triangular so remember that if you + + + align:start position:0% +three triangular so remember that if you +have the one right function + + align:start position:0% +have the one right function + + + align:start position:0% +have the one right function +i mean yeah one like function then you + + align:start position:0% +i mean yeah one like function then you + + + align:start position:0% +i mean yeah one like function then you +move two left function so you're going + + align:start position:0% +move two left function so you're going + + + align:start position:0% +move two left function so you're going +to have one triangulation one triangular + + align:start position:0% +to have one triangulation one triangular + + + align:start position:0% +to have one triangulation one triangular +so since we have two vector functions so + + align:start position:0% +so since we have two vector functions so + + + align:start position:0% +so since we have two vector functions so +whenever they first meet + + align:start position:0% +whenever they first meet + + + align:start position:0% +whenever they first meet +that we have the one train one triangle + + align:start position:0% +that we have the one train one triangle + + + align:start position:0% +that we have the one train one triangle +but the second and + + align:start position:0% +but the second and + + + align:start position:0% +but the second and +the two red functions are overlapped and + + align:start position:0% +the two red functions are overlapped and + + + align:start position:0% +the two red functions are overlapped and +we have the center triangle and + + align:start position:0% +we have the center triangle and + + + align:start position:0% +we have the center triangle and +like this we have the another triangle + + align:start position:0% +like this we have the another triangle + + + align:start position:0% +like this we have the another triangle +so we get the three triangles + + align:start position:0% +so we get the three triangles + + + align:start position:0% +so we get the three triangles +so that's the otf + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +if you expand with the frequencies of + + align:start position:0% +if you expand with the frequencies of + + + align:start position:0% +if you expand with the frequencies of +your input intensity then we are going + + align:start position:0% +your input intensity then we are going + + + align:start position:0% +your input intensity then we are going +to have infinite number of deflection + + align:start position:0% +to have infinite number of deflection + + + align:start position:0% +to have infinite number of deflection +but in atf case + + align:start position:0% +but in atf case + + + align:start position:0% +but in atf case +we have uh + + align:start position:0% +we have uh + + + align:start position:0% +we have uh +only first order and the minus first + + align:start position:0% +only first order and the minus first + + + align:start position:0% +only first order and the minus first +order and minus first order + + align:start position:0% +order and minus first order + + + align:start position:0% +order and minus first order +are going to be transmitted but in otf + + align:start position:0% +are going to be transmitted but in otf + + + align:start position:0% +are going to be transmitted but in otf +actually they are blocked because this + + align:start position:0% +actually they are blocked because this + + + align:start position:0% +actually they are blocked because this +is zero + + align:start position:0% +is zero + + + align:start position:0% +is zero +actually plus two and zero and minus two + + align:start position:0% +actually plus two and zero and minus two + + + align:start position:0% +actually plus two and zero and minus two +they are going to be transmitted + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +you just multiply + + align:start position:0% +you just multiply + + + align:start position:0% +you just multiply +these three data functions by the + + align:start position:0% +these three data functions by the + + + align:start position:0% +these three data functions by the +value of the atf i mean this this this + + align:start position:0% +value of the atf i mean this this this + + + align:start position:0% +value of the atf i mean this this this +and that's going to be your + + align:start position:0% +and that's going to be your + + + align:start position:0% +and that's going to be your +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +the free transform of your output + + align:start position:0% +the free transform of your output + + + align:start position:0% +the free transform of your output +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +which is + + align:start position:0% +which is + + + align:start position:0% +which is +this + + align:start position:0% +this + + + align:start position:0% +this +so 1 over 3 is just came from the the + + align:start position:0% +so 1 over 3 is just came from the the + + + align:start position:0% +so 1 over 3 is just came from the the +central data function because this is 1 + + align:start position:0% +central data function because this is 1 + + + align:start position:0% +central data function because this is 1 +so just 1 over three + + align:start position:0% +so just 1 over three + + + align:start position:0% +so just 1 over three +and + + align:start position:0% +and + + + align:start position:0% +and +for the first order + + align:start position:0% +for the first order + + + align:start position:0% +for the first order +at the point one and + + align:start position:0% +at the point one and + + + align:start position:0% +at the point one and +the minus point one and minus point one + + align:start position:0% +the minus point one and minus point one + + + align:start position:0% +the minus point one and minus point one +micrometer actually a vulnerable + + align:start position:0% +micrometer actually a vulnerable + + + align:start position:0% +micrometer actually a vulnerable +micrometer actually they have zero value + + align:start position:0% +micrometer actually they have zero value + + + align:start position:0% +micrometer actually they have zero value +so + + align:start position:0% +so + + + align:start position:0% +so +i multiply by zero + + align:start position:0% +i multiply by zero + + + align:start position:0% +i multiply by zero +and this for the second order + + align:start position:0% +and this for the second order + + + align:start position:0% +and this for the second order +i have one over two which is + + align:start position:0% +i have one over two which is + + + align:start position:0% +i have one over two which is +this value here and here + + align:start position:0% +this value here and here + + + align:start position:0% +this value here and here +so that is the you know free transfer of + + align:start position:0% +so that is the you know free transfer of + + + align:start position:0% +so that is the you know free transfer of +the output intensity + + align:start position:0% + + + + align:start position:0% + +so if you + + align:start position:0% +so if you + + + align:start position:0% +so if you +compute the inverse spread transform of + + align:start position:0% +compute the inverse spread transform of + + + align:start position:0% +compute the inverse spread transform of +this equation then we are going to have + + align:start position:0% +this equation then we are going to have + + + align:start position:0% +this equation then we are going to have +1 over 3 and 1 over 2 and two exponent + + align:start position:0% +1 over 3 and 1 over 2 and two exponent + + + align:start position:0% +1 over 3 and 1 over 2 and two exponent +two exponential which is actually + + align:start position:0% +two exponential which is actually + + + align:start position:0% +two exponential which is actually +uh cosine + + align:start position:0% +uh cosine + + + align:start position:0% +uh cosine +like this + + align:start position:0% +like this + + + align:start position:0% +like this +so in terms of grayscale image we have + + align:start position:0% +so in terms of grayscale image we have + + + align:start position:0% +so in terms of grayscale image we have +the + + align:start position:0% +the + + + align:start position:0% +the +binary amplitude gradient which vary + + align:start position:0% +binary amplitude gradient which vary + + + align:start position:0% +binary amplitude gradient which vary +just black or white like this + + align:start position:0% +just black or white like this + + + align:start position:0% +just black or white like this +but if you go through this 4-f system at + + align:start position:0% +but if you go through this 4-f system at + + + align:start position:0% +but if you go through this 4-f system at +the image you're going to have this kind + + align:start position:0% +the image you're going to have this kind + + + align:start position:0% +the image you're going to have this kind +of gray scale + + align:start position:0% +of gray scale + + + align:start position:0% +of gray scale +because you know contrast is just + + align:start position:0% + + + + align:start position:0% + +three 0.1.1034 + + align:start position:0% + + + + align:start position:0% + +one or three four so it's very little + + align:start position:0% +one or three four so it's very little + + + align:start position:0% +one or three four so it's very little +right so + + align:start position:0% +right so + + + align:start position:0% +right so +and uh the average value is about point + + align:start position:0% +and uh the average value is about point + + + align:start position:0% +and uh the average value is about point +three + + align:start position:0% +three + + + align:start position:0% +three +three or something so basically it looks + + align:start position:0% +three or something so basically it looks + + + align:start position:0% +three or something so basically it looks +great with the little uh wiggling + + align:start position:0% + + + + align:start position:0% + +so you know atf basically tells you the + + align:start position:0% +so you know atf basically tells you the + + + align:start position:0% +so you know atf basically tells you the +contrast i mean contrast of the + + align:start position:0% +contrast i mean contrast of the + + + align:start position:0% +contrast i mean contrast of the +particular spatial frequency + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so + + align:start position:0% + + + + align:start position:0% + +yeah what happened i mean the orders at + + align:start position:0% +yeah what happened i mean the orders at + + + align:start position:0% +yeah what happened i mean the orders at +this side so if my + + align:start position:0% +this side so if my + + + align:start position:0% +this side so if my +you know otf is zero then what kind of + + align:start position:0% +you know otf is zero then what kind of + + + align:start position:0% +you know otf is zero then what kind of +image i can expect + + align:start position:0% + + + + align:start position:0% + +it's black + + align:start position:0% + + + + align:start position:0% + +it's not white right + + align:start position:0% +it's not white right + + + align:start position:0% +it's not white right +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so if it is zero + + align:start position:0% +so if it is zero + + + align:start position:0% +so if it is zero +i mean if the value are zero + + align:start position:0% +i mean if the value are zero + + + align:start position:0% +i mean if the value are zero +then + + align:start position:0% +then + + + align:start position:0% +then +um + + align:start position:0% + + + + align:start position:0% + +but i still have dc term right so some + + align:start position:0% +but i still have dc term right so some + + + align:start position:0% +but i still have dc term right so some +kind of gray scale + + align:start position:0% +kind of gray scale + + + align:start position:0% +kind of gray scale +but i don't see any uh + + align:start position:0% +but i don't see any uh + + + align:start position:0% +but i don't see any uh +demodulation + + align:start position:0% + + + + align:start position:0% + +you know otf is autocorrelation so you + + align:start position:0% +you know otf is autocorrelation so you + + + align:start position:0% +you know otf is autocorrelation so you +always have + + align:start position:0% +always have + + + align:start position:0% +always have +one at the dc frequency + + align:start position:0% +one at the dc frequency + + + align:start position:0% +one at the dc frequency +you know because you know you should + + align:start position:0% +you know because you know you should + + + align:start position:0% +you know because you know you should +move the two function but so they when + + align:start position:0% +move the two function but so they when + + + align:start position:0% +move the two function but so they when +they are exactly overlapped you always + + align:start position:0% +they are exactly overlapped you always + + + align:start position:0% +they are exactly overlapped you always +have a maximum value so + + align:start position:0% + + + + align:start position:0% + +you always have a dc term + + align:start position:0% + + + + align:start position:0% + +actually there is slightly different in + + align:start position:0% +actually there is slightly different in + + + align:start position:0% +actually there is slightly different in +current case right so atf case you can + + align:start position:0% +current case right so atf case you can + + + align:start position:0% +current case right so atf case you can +actually cancel this system right but + + align:start position:0% +actually cancel this system right but + + + align:start position:0% +actually cancel this system right but +otf you cannot cancel this term because + + align:start position:0% +otf you cannot cancel this term because + + + align:start position:0% +otf you cannot cancel this term because +it's autocorrelation + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +again we have a + + align:start position:0% +again we have a + + + align:start position:0% +again we have a +simulation with the mit layer so this + + align:start position:0% +simulation with the mit layer so this + + + align:start position:0% +simulation with the mit layer so this +particular + + align:start position:0% +particular + + + align:start position:0% +particular +circular aperture + + align:start position:0% +circular aperture + + + align:start position:0% +circular aperture +if i use if i illuminate with the + + align:start position:0% +if i use if i illuminate with the + + + align:start position:0% +if i use if i illuminate with the +coherent illumination then this is the + + align:start position:0% +coherent illumination then this is the + + + align:start position:0% +coherent illumination then this is the +image actually yes + + align:start position:0% +image actually yes + + + align:start position:0% +image actually yes +yeah in singapore side the + + align:start position:0% +yeah in singapore side the + + + align:start position:0% +yeah in singapore side the +ppt slides are not means they are + + align:start position:0% +ppt slides are not means they are + + + align:start position:0% +ppt slides are not means they are +phrased + + align:start position:0% +phrased + + + align:start position:0% +phrased +means still it is showing this example + + align:start position:0% +means still it is showing this example + + + align:start position:0% +means still it is showing this example +of band pass filtering + + align:start position:0% +of band pass filtering + + + align:start position:0% +of band pass filtering +slide number + + align:start position:0% +slide number + + + align:start position:0% +slide number +here or maybe it takes time or + + align:start position:0% + + + + align:start position:0% + +no it even didn't show that + + align:start position:0% +no it even didn't show that + + + align:start position:0% +no it even didn't show that +that input + + align:start position:0% +that input + + + align:start position:0% +that input +and output image + + align:start position:0% +and output image + + + align:start position:0% +and output image +when you explained about that contrast + + align:start position:0% +when you explained about that contrast + + + align:start position:0% +when you explained about that contrast +uh-huh + + align:start position:0% + + + + align:start position:0% + +uh just let me ask control + + align:start position:0% +uh just let me ask control + + + align:start position:0% +uh just let me ask control +hello + + align:start position:0% +hello + + + align:start position:0% +hello +hey control + + align:start position:0% + + + + align:start position:0% + +yes uh the same singapore side they + + align:start position:0% +yes uh the same singapore side they + + + align:start position:0% +yes uh the same singapore side they +their screen is freezed + + align:start position:0% +their screen is freezed + + + align:start position:0% +their screen is freezed +it's frozen yeah + + align:start position:0% +it's frozen yeah + + + align:start position:0% +it's frozen yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yeah + + align:start position:0% + + + + align:start position:0% + +are they gonna reset the system so yeah + + align:start position:0% +are they gonna reset the system so yeah + + + align:start position:0% +are they gonna reset the system so yeah +so let me just take a few moments + + align:start position:0% +so let me just take a few moments + + + align:start position:0% +so let me just take a few moments +any questions so far + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yeah so actually + + align:start position:0% + + + + align:start position:0% + +uh yeah actually i'm going to talk about + + align:start position:0% +uh yeah actually i'm going to talk about + + + align:start position:0% +uh yeah actually i'm going to talk about +it but you know + + align:start position:0% +it but you know + + + align:start position:0% +it but you know +in general if you use the equivalent + + align:start position:0% +in general if you use the equivalent + + + align:start position:0% +in general if you use the equivalent +light then you don't see any phase + + align:start position:0% +light then you don't see any phase + + + align:start position:0% +light then you don't see any phase +effect right because you know you're + + align:start position:0% +effect right because you know you're + + + align:start position:0% +effect right because you know you're +going to take the magnitude square so + + align:start position:0% +going to take the magnitude square so + + + align:start position:0% +going to take the magnitude square so +it doesn't really matter so you don't + + align:start position:0% +it doesn't really matter so you don't + + + align:start position:0% +it doesn't really matter so you don't +see any i mean you barely see some + + align:start position:0% +see any i mean you barely see some + + + align:start position:0% +see any i mean you barely see some +variation but usually + + align:start position:0% +variation but usually + + + align:start position:0% +variation but usually +it's not traumatic as coherent + + align:start position:0% +it's not traumatic as coherent + + + align:start position:0% +it's not traumatic as coherent +elimination + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +what i was about to say + + align:start position:0% + + + + align:start position:0% + +oh yeah so mtf is just making to the + + align:start position:0% +oh yeah so mtf is just making to the + + + align:start position:0% +oh yeah so mtf is just making to the +magnitude of the otf right so we we + + align:start position:0% +magnitude of the otf right so we we + + + align:start position:0% +magnitude of the otf right so we we +haven't talked about any + + align:start position:0% +haven't talked about any + + + align:start position:0% +haven't talked about any +phase of the rtf so what's the effect of + + align:start position:0% +phase of the rtf so what's the effect of + + + align:start position:0% +phase of the rtf so what's the effect of +the + + align:start position:0% +the + + + align:start position:0% +the +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +what is what does it mean i mean if i + + align:start position:0% +what is what does it mean i mean if i + + + align:start position:0% +what is what does it mean i mean if i +have + + align:start position:0% +have + + + align:start position:0% +have +some phase variation in otf + + align:start position:0% + + + + align:start position:0% + +can anyone guess + + align:start position:0% +can anyone guess + + + align:start position:0% +can anyone guess +so for example otf is always nine nine + + align:start position:0% +so for example otf is always nine nine + + + align:start position:0% +so for example otf is always nine nine +zero right is + + align:start position:0% +zero right is + + + align:start position:0% +zero right is +always + + align:start position:0% +always + + + align:start position:0% +always +zero or positive + + align:start position:0% +zero or positive + + + align:start position:0% +zero or positive +but you know his face can be zero or pi + + align:start position:0% +but you know his face can be zero or pi + + + align:start position:0% +but you know his face can be zero or pi +right + + align:start position:0% +right + + + align:start position:0% +right +so what if i have + + align:start position:0% +so what if i have + + + align:start position:0% +so what if i have +pi phase shift in otf + + align:start position:0% + + + + align:start position:0% + +for example i have + + align:start position:0% +for example i have + + + align:start position:0% +for example i have +assigned to the grading and at the + + align:start position:0% +assigned to the grading and at the + + + align:start position:0% +assigned to the grading and at the +output i have the sinusoidal gradient + + align:start position:0% +output i have the sinusoidal gradient + + + align:start position:0% +output i have the sinusoidal gradient +but what does it mean i have the pi + + align:start position:0% +but what does it mean i have the pi + + + align:start position:0% +but what does it mean i have the pi +phase shift + + align:start position:0% + + + + align:start position:0% + +not really yeah + + align:start position:0% +not really yeah + + + align:start position:0% +not really yeah +what money what happens if you + + align:start position:0% +what money what happens if you + + + align:start position:0% +what money what happens if you +shift by + + align:start position:0% +shift by + + + align:start position:0% +shift by +pi + + align:start position:0% +pi + + + align:start position:0% +pi +i mean if you move the cosine by pi + + align:start position:0% +i mean if you move the cosine by pi + + + align:start position:0% +i mean if you move the cosine by pi +you get sine right + + align:start position:0% +you get sine right + + + align:start position:0% +you get sine right +so you you have cosine pattern here + + align:start position:0% +so you you have cosine pattern here + + + align:start position:0% +so you you have cosine pattern here +and if you have pi phase shift then + + align:start position:0% +and if you have pi phase shift then + + + align:start position:0% +and if you have pi phase shift then +you're going to have the sine pattern + + align:start position:0% +you're going to have the sine pattern + + + align:start position:0% +you're going to have the sine pattern +which means + + align:start position:0% +which means + + + align:start position:0% +which means +you flip the black and white at the + + align:start position:0% +you flip the black and white at the + + + align:start position:0% +you flip the black and white at the +image + + align:start position:0% + + + + align:start position:0% + +yeah so i flipped the black but still i + + align:start position:0% +yeah so i flipped the black but still i + + + align:start position:0% +yeah so i flipped the black but still i +change the black and white right yeah + + align:start position:0% +change the black and white right yeah + + + align:start position:0% +change the black and white right yeah +not the sine to cosine that's why + + align:start position:0% + + + + align:start position:0% + +i singapore uh otherwise can you guys + + align:start position:0% +i singapore uh otherwise can you guys + + + align:start position:0% +i singapore uh otherwise can you guys +see the side right now or + + align:start position:0% +see the side right now or + + + align:start position:0% +see the side right now or +yes all right yeah thanks yeah uh i have + + align:start position:0% +yes all right yeah thanks yeah uh i have + + + align:start position:0% +yes all right yeah thanks yeah uh i have +one question uh how do you enter this + + align:start position:0% +one question uh how do you enter this + + + align:start position:0% +one question uh how do you enter this +five phase shift in otf + + align:start position:0% +five phase shift in otf + + + align:start position:0% +five phase shift in otf +uh so if you have five phase shift in + + align:start position:0% +uh so if you have five phase shift in + + + align:start position:0% +uh so if you have five phase shift in +otf then basically you flip the black + + align:start position:0% +otf then basically you flip the black + + + align:start position:0% +otf then basically you flip the black +and white + + align:start position:0% +and white + + + align:start position:0% +and white +so your input image is + + align:start position:0% +so your input image is + + + align:start position:0% +so your input image is +black + + align:start position:0% +black + + + align:start position:0% +black +let's say the black white black white + + align:start position:0% +let's say the black white black white + + + align:start position:0% +let's say the black white black white +and your image is going to be white + + align:start position:0% +and your image is going to be white + + + align:start position:0% +and your image is going to be white +black white black + + align:start position:0% +black white black + + + align:start position:0% +black white black +now my question is like uh + + align:start position:0% +now my question is like uh + + + align:start position:0% +now my question is like uh +physically how means how how do you + + align:start position:0% +physically how means how how do you + + + align:start position:0% +physically how means how how do you +introduce that controllable phase shift + + align:start position:0% +introduce that controllable phase shift + + + align:start position:0% +introduce that controllable phase shift +in otf + + align:start position:0% + + + + align:start position:0% + +um so + + align:start position:0% +um so + + + align:start position:0% +um so +you know + + align:start position:0% +you know + + + align:start position:0% +you know +this atf can be complex right so if you + + align:start position:0% +this atf can be complex right so if you + + + align:start position:0% +this atf can be complex right so if you +come if you compute the autocorrelation + + align:start position:0% +come if you compute the autocorrelation + + + align:start position:0% +come if you compute the autocorrelation +then + + align:start position:0% +then + + + align:start position:0% +then +actually you can have a negative value + + align:start position:0% +actually you can have a negative value + + + align:start position:0% +actually you can have a negative value +of otf + + align:start position:0% +of otf + + + align:start position:0% +of otf +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and if you have the negative value in + + align:start position:0% +and if you have the negative value in + + + align:start position:0% +and if you have the negative value in +otf which means you have still positive + + align:start position:0% +otf which means you have still positive + + + align:start position:0% +otf which means you have still positive +magnitude but you have some negative uh + + align:start position:0% +magnitude but you have some negative uh + + + align:start position:0% +magnitude but you have some negative uh +i mean pi basically pi phase right so if + + align:start position:0% +i mean pi basically pi phase right so if + + + align:start position:0% +i mean pi basically pi phase right so if +you want to do that kind of thing + + align:start position:0% +you want to do that kind of thing + + + align:start position:0% +you want to do that kind of thing +basically you have some complex + + align:start position:0% +basically you have some complex + + + align:start position:0% +basically you have some complex +transparency at your pp mask + + align:start position:0% +transparency at your pp mask + + + align:start position:0% +transparency at your pp mask +yeah but if you have clear aperture then + + align:start position:0% +yeah but if you have clear aperture then + + + align:start position:0% +yeah but if you have clear aperture then +you don't you don't get that + + align:start position:0% +you don't you don't get that + + + align:start position:0% +you don't you don't get that +effect + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yeah so let me continue this slide so + + align:start position:0% +yeah so let me continue this slide so + + + align:start position:0% +yeah so let me continue this slide so +this i mean these two image we already + + align:start position:0% +this i mean these two image we already + + + align:start position:0% +this i mean these two image we already +seen + + align:start position:0% +seen + + + align:start position:0% +seen +maybe two or three lectures ago so this + + align:start position:0% +maybe two or three lectures ago so this + + + align:start position:0% +maybe two or three lectures ago so this +is mit lecture i mean the image of the + + align:start position:0% +is mit lecture i mean the image of the + + + align:start position:0% +is mit lecture i mean the image of the +mit ladder with the coherent elimination + + align:start position:0% +mit ladder with the coherent elimination + + + align:start position:0% +mit ladder with the coherent elimination +and + + align:start position:0% +and + + + align:start position:0% +and +this the right to + + align:start position:0% +this the right to + + + align:start position:0% +this the right to +the + + align:start position:0% +the + + + align:start position:0% +the +right two images are + + align:start position:0% +right two images are + + + align:start position:0% +right two images are +obtained with the in query elimination + + align:start position:0% +obtained with the in query elimination + + + align:start position:0% +obtained with the in query elimination +so + + align:start position:0% +so + + + align:start position:0% +so +but + + align:start position:0% +but + + + align:start position:0% +but +i can notice two main difference here so + + align:start position:0% +i can notice two main difference here so + + + align:start position:0% +i can notice two main difference here so +so if i use the in-query elimination i + + align:start position:0% +so if i use the in-query elimination i + + + align:start position:0% +so if i use the in-query elimination i +basically the image looks sharper than + + align:start position:0% +basically the image looks sharper than + + + align:start position:0% +basically the image looks sharper than +the one with the cohen + + align:start position:0% +the one with the cohen + + + align:start position:0% +the one with the cohen +and that's because + + align:start position:0% +and that's because + + + align:start position:0% +and that's because +your you know otf has a higher choice of + + align:start position:0% +your you know otf has a higher choice of + + + align:start position:0% +your you know otf has a higher choice of +higher quarter frequency right even + + align:start position:0% +higher quarter frequency right even + + + align:start position:0% +higher quarter frequency right even +though they get attenuated but basically + + align:start position:0% +though they get attenuated but basically + + + align:start position:0% +though they get attenuated but basically +it can pass through the higher special + + align:start position:0% +it can pass through the higher special + + + align:start position:0% +it can pass through the higher special +frequencies so that's why + + align:start position:0% +frequencies so that's why + + + align:start position:0% +frequencies so that's why +it preserves higher frequency more + + align:start position:0% +it preserves higher frequency more + + + align:start position:0% +it preserves higher frequency more +increases more higher frequency + + align:start position:0% +increases more higher frequency + + + align:start position:0% +increases more higher frequency +preserve higher frequency + + align:start position:0% + + + + align:start position:0% + +it's same thing here so with the cohen + + align:start position:0% +it's same thing here so with the cohen + + + align:start position:0% +it's same thing here so with the cohen +light you barely see the eye + + align:start position:0% +light you barely see the eye + + + align:start position:0% +light you barely see the eye +letter i but you can still see the mit + + align:start position:0% +letter i but you can still see the mit + + + align:start position:0% +letter i but you can still see the mit +right + + align:start position:0% +right + + + align:start position:0% +right +and another difference is actually if + + align:start position:0% +and another difference is actually if + + + align:start position:0% +and another difference is actually if +you see the n or t there are some + + align:start position:0% +you see the n or t there are some + + + align:start position:0% +you see the n or t there are some +variations + + align:start position:0% +variations + + + align:start position:0% +variations +like black or white some wiggling in m + + align:start position:0% +like black or white some wiggling in m + + + align:start position:0% +like black or white some wiggling in m +and t here + + align:start position:0% +and t here + + + align:start position:0% +and t here +but + + align:start position:0% +but + + + align:start position:0% +but +in in coordinate case you + + align:start position:0% +in in coordinate case you + + + align:start position:0% +in in coordinate case you +intensity is more like uniform you don't + + align:start position:0% +intensity is more like uniform you don't + + + align:start position:0% +intensity is more like uniform you don't +see any + + align:start position:0% +see any + + + align:start position:0% +see any +some weird variation so + + align:start position:0% +some weird variation so + + + align:start position:0% +some weird variation so +that's the another difference + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so so if you use the incoherent in + + align:start position:0% +so so if you use the incoherent in + + + align:start position:0% +so so if you use the incoherent in +current light generally + + align:start position:0% +current light generally + + + align:start position:0% +current light generally +you don't have + + align:start position:0% +you don't have + + + align:start position:0% +you don't have +the ringing artifact as i just described + + align:start position:0% +the ringing artifact as i just described + + + align:start position:0% +the ringing artifact as i just described +and also no speckle is in korean so you + + align:start position:0% +and also no speckle is in korean so you + + + align:start position:0% +and also no speckle is in korean so you +know you're not going to see any + + align:start position:0% +know you're not going to see any + + + align:start position:0% +know you're not going to see any +you know interference + + align:start position:0% +you know interference + + + align:start position:0% +you know interference +and + + align:start position:0% +and + + + align:start position:0% +and +it has higher bandwidth because you know + + align:start position:0% +it has higher bandwidth because you know + + + align:start position:0% +it has higher bandwidth because you know +the quarter frequency is twice higher + + align:start position:0% +the quarter frequency is twice higher + + + align:start position:0% +the quarter frequency is twice higher +than the color frequency in atm + + align:start position:0% +than the color frequency in atm + + + align:start position:0% +than the color frequency in atm +so you know you can see basically higher + + align:start position:0% +so you know you can see basically higher + + + align:start position:0% +so you know you can see basically higher +the smaller feature + + align:start position:0% +the smaller feature + + + align:start position:0% +the smaller feature +i mean the two + + align:start position:0% +i mean the two + + + align:start position:0% +i mean the two +uh point + + align:start position:0% +uh point + + + align:start position:0% +uh point +the closer okay so you can see the hot + + align:start position:0% +the closer okay so you can see the hot + + + align:start position:0% +the closer okay so you can see the hot +the smaller feature + + align:start position:0% +the smaller feature + + + align:start position:0% +the smaller feature +and + + align:start position:0% +and + + + align:start position:0% +and +yeah but if i describe as i answered to + + align:start position:0% +yeah but if i describe as i answered to + + + align:start position:0% +yeah but if i describe as i answered to +uh + + align:start position:0% +uh + + + align:start position:0% +uh +javascription uh in current imaging is + + align:start position:0% +javascription uh in current imaging is + + + align:start position:0% +javascription uh in current imaging is +insensitive to phase variation so + + align:start position:0% +insensitive to phase variation so + + + align:start position:0% +insensitive to phase variation so +and + + align:start position:0% +and + + + align:start position:0% +and +yeah so mostly we just deal with the + + align:start position:0% +yeah so mostly we just deal with the + + + align:start position:0% +yeah so mostly we just deal with the +monochromatic especially in korean but + + align:start position:0% +monochromatic especially in korean but + + + align:start position:0% +monochromatic especially in korean but +if you have polychromatic which is + + align:start position:0% +if you have polychromatic which is + + + align:start position:0% +if you have polychromatic which is +broadband and you + + align:start position:0% +broadband and you + + + align:start position:0% +broadband and you +and you're gonna have some chromatic + + align:start position:0% +and you're gonna have some chromatic + + + align:start position:0% +and you're gonna have some chromatic +aberration but + + align:start position:0% +aberration but + + + align:start position:0% +aberration but +again you can define + + align:start position:0% +again you can define + + + align:start position:0% +again you can define +all this otf or mtf or poinsettia + + align:start position:0% +all this otf or mtf or poinsettia + + + align:start position:0% +all this otf or mtf or poinsettia +function for each different wavelength + + align:start position:0% +function for each different wavelength + + + align:start position:0% +function for each different wavelength +so you know you can just extend this in + + align:start position:0% +so you know you can just extend this in + + + align:start position:0% +so you know you can just extend this in +straightforward fashion + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +it's the end of show so + + align:start position:0% +it's the end of show so + + + align:start position:0% +it's the end of show so +any question + + align:start position:0% + + + + align:start position:0% + +yeah so the second message of the + + align:start position:0% +yeah so the second message of the + + + align:start position:0% +yeah so the second message of the +today's lecture is you know + + align:start position:0% +today's lecture is you know + + + align:start position:0% +today's lecture is you know +if you have coherent illumination then + + align:start position:0% +if you have coherent illumination then + + + align:start position:0% +if you have coherent illumination then +you have linear uh convolution in field + + align:start position:0% +you have linear uh convolution in field + + + align:start position:0% +you have linear uh convolution in field +but if you have incoherent case + + align:start position:0% +but if you have incoherent case + + + align:start position:0% +but if you have incoherent case +and you have + + align:start position:0% +and you have + + + align:start position:0% +and you have +the linear linear relation in intensity + + align:start position:0% +the linear linear relation in intensity + + + align:start position:0% +the linear linear relation in intensity +and + + align:start position:0% +and + + + align:start position:0% +and +for in coin coinlight you have to deal + + align:start position:0% +for in coin coinlight you have to deal + + + align:start position:0% +for in coin coinlight you have to deal +with the otf which is autocorrelation of + + align:start position:0% +with the otf which is autocorrelation of + + + align:start position:0% +with the otf which is autocorrelation of +atf + + align:start position:0% +atf + + + align:start position:0% +atf +and that's pretty much about it + + align:start position:0% + + + + align:start position:0% + +yeah if you don't have question then + + align:start position:0% +yeah if you don't have question then + + + align:start position:0% +yeah if you don't have question then +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +next monday \ No newline at end of file diff --git a/WCw7gzz5RZY.txt b/WCw7gzz5RZY.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa9acacd08a92730a7d64170beeb85e3263874aa --- /dev/null +++ b/WCw7gzz5RZY.txt @@ -0,0 +1,4008 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license your support + + align:start position:0% +a creative commons license your support + + + align:start position:0% +a creative commons license your support +will help mit opencourseware continue to + + align:start position:0% +will help mit opencourseware continue to + + + align:start position:0% +will help mit opencourseware continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right so our group is going to talk + + align:start position:0% +all right so our group is going to talk + + + align:start position:0% +all right so our group is going to talk +about the accuracy requirements in the + + align:start position:0% +about the accuracy requirements in the + + + align:start position:0% +about the accuracy requirements in the +mechanical assembly of photonic crystals + + align:start position:0% +mechanical assembly of photonic crystals + + + align:start position:0% +mechanical assembly of photonic crystals +um so to do so + + align:start position:0% +um so to do so + + + align:start position:0% +um so to do so +we'll definitely have to introduce what + + align:start position:0% +we'll definitely have to introduce what + + + align:start position:0% +we'll definitely have to introduce what +a photonic crystal is + + align:start position:0% +a photonic crystal is + + + align:start position:0% +a photonic crystal is +um then martin is going to talk about + + align:start position:0% +um then martin is going to talk about + + + align:start position:0% +um then martin is going to talk about +the um + + align:start position:0% +the um + + + align:start position:0% +the um +the fabrication process + + align:start position:0% +the fabrication process + + + align:start position:0% +the fabrication process +of 3d photonic crystals and corey is + + align:start position:0% +of 3d photonic crystals and corey is + + + align:start position:0% +of 3d photonic crystals and corey is +going to + + align:start position:0% +going to + + + align:start position:0% +going to +have this little application + + align:start position:0% +have this little application + + + align:start position:0% +have this little application +that it carried out + + align:start position:0% +that it carried out + + + align:start position:0% +that it carried out +to see the influence of + + align:start position:0% +to see the influence of + + + align:start position:0% +to see the influence of +misalignment in a 3d structure on the + + align:start position:0% +misalignment in a 3d structure on the + + + align:start position:0% +misalignment in a 3d structure on the +properties of + + align:start position:0% +properties of + + + align:start position:0% +properties of +photonics so an intuitive way to + + align:start position:0% +photonics so an intuitive way to + + + align:start position:0% +photonics so an intuitive way to +introduce photonic crystal is to use the + + align:start position:0% +introduce photonic crystal is to use the + + + align:start position:0% +introduce photonic crystal is to use the +analogy with elect semiconductors in + + align:start position:0% +analogy with elect semiconductors in + + + align:start position:0% +analogy with elect semiconductors in +electronics because photonic crystals + + align:start position:0% +electronics because photonic crystals + + + align:start position:0% +electronics because photonic crystals +are two optics what um semiconductors + + align:start position:0% +are two optics what um semiconductors + + + align:start position:0% +are two optics what um semiconductors +are to electronics which means that + + align:start position:0% +are to electronics which means that + + + align:start position:0% +are to electronics which means that +in uh + + align:start position:0% +in uh + + + align:start position:0% +in uh +semiconductors depending on the electron + + align:start position:0% +semiconductors depending on the electron + + + align:start position:0% +semiconductors depending on the electron +energy you can or cannot propagate a + + align:start position:0% +energy you can or cannot propagate a + + + align:start position:0% +energy you can or cannot propagate a +current in it + + align:start position:0% +current in it + + + align:start position:0% +current in it +in photonic crystal depending on the the + + align:start position:0% +in photonic crystal depending on the the + + + align:start position:0% +in photonic crystal depending on the the +frequency of your wave you will or will + + align:start position:0% +frequency of your wave you will or will + + + align:start position:0% +frequency of your wave you will or will +not propagate + + align:start position:0% +not propagate + + + align:start position:0% +not propagate +waves in it and so to understand this + + align:start position:0% +waves in it and so to understand this + + + align:start position:0% +waves in it and so to understand this +interesting property + + align:start position:0% +interesting property + + + align:start position:0% +interesting property +uh you have to go back to maxwell + + align:start position:0% +uh you have to go back to maxwell + + + align:start position:0% +uh you have to go back to maxwell +equations i'd be quick on this slide + + align:start position:0% +equations i'd be quick on this slide + + + align:start position:0% +equations i'd be quick on this slide +don't worry + + align:start position:0% +don't worry + + + align:start position:0% +don't worry +uh but + + align:start position:0% +uh but + + + align:start position:0% +uh but +you know that + + align:start position:0% +you know that + + + align:start position:0% +you know that +from the the set of the four maxwell's + + align:start position:0% +from the the set of the four maxwell's + + + align:start position:0% +from the the set of the four maxwell's +equation you can write it as a + + align:start position:0% +equation you can write it as a + + + align:start position:0% +equation you can write it as a +eigenvalue problem if you assume that + + align:start position:0% +eigenvalue problem if you assume that + + + align:start position:0% +eigenvalue problem if you assume that +your waves are + + align:start position:0% +your waves are + + + align:start position:0% +your waves are +sinusoidal + + align:start position:0% +sinusoidal + + + align:start position:0% +sinusoidal +and now if you + + align:start position:0% +and now if you + + + align:start position:0% +and now if you +introduce periodicity in your crystal + + align:start position:0% +introduce periodicity in your crystal + + + align:start position:0% +introduce periodicity in your crystal +and the block theorem says that you can + + align:start position:0% +and the block theorem says that you can + + + align:start position:0% +and the block theorem says that you can +write + + align:start position:0% +write + + + align:start position:0% +write +the magnetic field + + align:start position:0% +the magnetic field + + + align:start position:0% +the magnetic field +like this + + align:start position:0% +like this + + + align:start position:0% +like this +where uh the k vector is in the + + align:start position:0% +where uh the k vector is in the + + + align:start position:0% +where uh the k vector is in the +exponential + + align:start position:0% +exponential + + + align:start position:0% +exponential +times a periodic function where + + align:start position:0% +times a periodic function where + + + align:start position:0% +times a periodic function where +u is a + + align:start position:0% +u is a + + + align:start position:0% +u is a +a periodic function + + align:start position:0% +a periodic function + + + align:start position:0% +a periodic function +r is the periodicity of your crystal + + align:start position:0% +r is the periodicity of your crystal + + + align:start position:0% +r is the periodicity of your crystal +lattice + + align:start position:0% +lattice + + + align:start position:0% +lattice +and so the first eigenvalue problem + + align:start position:0% +and so the first eigenvalue problem + + + align:start position:0% +and so the first eigenvalue problem +because becomes this one which can be + + align:start position:0% +because becomes this one which can be + + + align:start position:0% +because becomes this one which can be +solved numerically + + align:start position:0% +solved numerically + + + align:start position:0% +solved numerically +which is what a corey uh + + align:start position:0% +which is what a corey uh + + + align:start position:0% +which is what a corey uh +has done in the simulations + + align:start position:0% +has done in the simulations + + + align:start position:0% +has done in the simulations +and you manage to extract these those + + align:start position:0% +and you manage to extract these those + + + align:start position:0% +and you manage to extract these those +eigenvalues + + align:start position:0% +eigenvalues + + + align:start position:0% +eigenvalues +which are the dispersion relation + + align:start position:0% +which are the dispersion relation + + + align:start position:0% +which are the dispersion relation +between the frequency and the k vector + + align:start position:0% + + + + align:start position:0% + +so if we take the example of a 1d + + align:start position:0% +so if we take the example of a 1d + + + align:start position:0% +so if we take the example of a 1d +photonic crystal like this + + align:start position:0% +photonic crystal like this + + + align:start position:0% +photonic crystal like this +with no periodicity which means that all + + align:start position:0% +with no periodicity which means that all + + + align:start position:0% +with no periodicity which means that all +the permittivity in the in the crystal + + align:start position:0% +the permittivity in the in the crystal + + + align:start position:0% +the permittivity in the in the crystal +are the same equals one for example we + + align:start position:0% +are the same equals one for example we + + + align:start position:0% +are the same equals one for example we +have this relation which is uh + + align:start position:0% +have this relation which is uh + + + align:start position:0% +have this relation which is uh +proportional the frequency is + + align:start position:0% +proportional the frequency is + + + align:start position:0% +proportional the frequency is +proportional to the 2k + + align:start position:0% +proportional to the 2k + + + align:start position:0% +proportional to the 2k +but now if you take different + + align:start position:0% +but now if you take different + + + align:start position:0% +but now if you take different +permittivity in the crystal you + + align:start position:0% +permittivity in the crystal you + + + align:start position:0% +permittivity in the crystal you +introduce those range of frequency in + + align:start position:0% +introduce those range of frequency in + + + align:start position:0% +introduce those range of frequency in +which + + align:start position:0% +which + + + align:start position:0% +which +wave + + align:start position:0% +wave + + + align:start position:0% +wave +cannot propagate and the width the size + + align:start position:0% +cannot propagate and the width the size + + + align:start position:0% +cannot propagate and the width the size +and the position of those gaps the band + + align:start position:0% +and the position of those gaps the band + + + align:start position:0% +and the position of those gaps the band +gaps + + align:start position:0% +gaps + + + align:start position:0% +gaps +are a function of the permeability or + + align:start position:0% +are a function of the permeability or + + + align:start position:0% +are a function of the permeability or +the geometry of your lattice in the + + align:start position:0% +the geometry of your lattice in the + + + align:start position:0% +the geometry of your lattice in the +crystal + + align:start position:0% + + + + align:start position:0% + +uh note that we're only interested uh + + align:start position:0% +uh note that we're only interested uh + + + align:start position:0% +uh note that we're only interested uh +because of the shape of those uh + + align:start position:0% +because of the shape of those uh + + + align:start position:0% +because of the shape of those uh +magnetic field as exponential of ikr + + align:start position:0% +magnetic field as exponential of ikr + + + align:start position:0% +magnetic field as exponential of ikr +then we're only interested and because + + align:start position:0% +then we're only interested and because + + + align:start position:0% +then we're only interested and because +of the the the paradisity in the crystal + + align:start position:0% +of the the the paradisity in the crystal + + + align:start position:0% +of the the the paradisity in the crystal +we aren't interested in this small range + + align:start position:0% +we aren't interested in this small range + + + align:start position:0% +we aren't interested in this small range +of k vectors from + + align:start position:0% +of k vectors from + + + align:start position:0% +of k vectors from +minus k over pi to plus k over pi + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +to illustrate this interesting property + + align:start position:0% +to illustrate this interesting property + + + align:start position:0% +to illustrate this interesting property +we brought + + align:start position:0% +we brought + + + align:start position:0% +we brought +1d photonic crystal + + align:start position:0% +1d photonic crystal + + + align:start position:0% +1d photonic crystal +which can only pass blue light which + + align:start position:0% +which can only pass blue light which + + + align:start position:0% +which can only pass blue light which +means that it will the the vein gaps are + + align:start position:0% +means that it will the the vein gaps are + + + align:start position:0% +means that it will the the vein gaps are +everywhere + + align:start position:0% +everywhere + + + align:start position:0% +everywhere +where you don't propagate blue + + align:start position:0% +where you don't propagate blue + + + align:start position:0% +where you don't propagate blue +so which you can see if you if you shine + + align:start position:0% +so which you can see if you if you shine + + + align:start position:0% +so which you can see if you if you shine +it's going to be easy + + align:start position:0% +it's going to be easy + + + align:start position:0% +it's going to be easy +if you shine blue light + + align:start position:0% +if you shine blue light + + + align:start position:0% +if you shine blue light +if you shine sorry if you eliminate it + + align:start position:0% +if you shine sorry if you eliminate it + + + align:start position:0% +if you shine sorry if you eliminate it +with a white + + align:start position:0% +with a white + + + align:start position:0% +with a white +white light you will + + align:start position:0% + + + + align:start position:0% + +you will + + align:start position:0% +you will + + + align:start position:0% +you will +transmit only blue now if you + + align:start position:0% +transmit only blue now if you + + + align:start position:0% +transmit only blue now if you +shine if you eliminate with a red light + + align:start position:0% +shine if you eliminate with a red light + + + align:start position:0% +shine if you eliminate with a red light +then it will block almost everything + + align:start position:0% +then it will block almost everything + + + align:start position:0% +then it will block almost everything +as you can see on the second i don't + + align:start position:0% +as you can see on the second i don't + + + align:start position:0% +as you can see on the second i don't +know if you can see it but + + align:start position:0% +know if you can see it but + + + align:start position:0% +know if you can see it but +basically there's nothing to see + + align:start position:0% +basically there's nothing to see + + + align:start position:0% +basically there's nothing to see +the only problem with the 1d photonic + + align:start position:0% +the only problem with the 1d photonic + + + align:start position:0% +the only problem with the 1d photonic +crystal if you shine off axis then it + + align:start position:0% +crystal if you shine off axis then it + + + align:start position:0% +crystal if you shine off axis then it +loses its property + + align:start position:0% +loses its property + + + align:start position:0% +loses its property +and now you should be able to see this + + align:start position:0% +and now you should be able to see this + + + align:start position:0% +and now you should be able to see this +red spot over there + + align:start position:0% +red spot over there + + + align:start position:0% +red spot over there +and this + + align:start position:0% +and this + + + align:start position:0% +and this +is the reason why people are trying to + + align:start position:0% +is the reason why people are trying to + + + align:start position:0% +is the reason why people are trying to +now create 2d or 3d photonic + + align:start position:0% +now create 2d or 3d photonic + + + align:start position:0% +now create 2d or 3d photonic +crystals to keep this + + align:start position:0% +crystals to keep this + + + align:start position:0% +crystals to keep this +property in all the directions and with + + align:start position:0% +property in all the directions and with + + + align:start position:0% +property in all the directions and with +all polarization + + align:start position:0% +all polarization + + + align:start position:0% +all polarization +the applications of photon photonic + + align:start position:0% +the applications of photon photonic + + + align:start position:0% +the applications of photon photonic +crystals are well as you saw + + align:start position:0% +crystals are well as you saw + + + align:start position:0% +crystals are well as you saw +to filter some of the frequencies but + + align:start position:0% +to filter some of the frequencies but + + + align:start position:0% +to filter some of the frequencies but +also to use it as a perfect mirror + + align:start position:0% +also to use it as a perfect mirror + + + align:start position:0% +also to use it as a perfect mirror +can also use it as wave guides + + align:start position:0% +can also use it as wave guides + + + align:start position:0% +can also use it as wave guides +or cavities or + + align:start position:0% +or cavities or + + + align:start position:0% +or cavities or +light shaping + + align:start position:0% +light shaping + + + align:start position:0% +light shaping +and now martin's going to talk about the + + align:start position:0% +and now martin's going to talk about the + + + align:start position:0% +and now martin's going to talk about the +fabrication + + align:start position:0% + + + + align:start position:0% + +thank you sebastian so this really + + align:start position:0% +thank you sebastian so this really + + + align:start position:0% +thank you sebastian so this really +photonic crystal seems really + + align:start position:0% +photonic crystal seems really + + + align:start position:0% +photonic crystal seems really +interesting but the main problem is how + + align:start position:0% +interesting but the main problem is how + + + align:start position:0% +interesting but the main problem is how +can you fabricate them so we can there + + align:start position:0% +can you fabricate them so we can there + + + align:start position:0% +can you fabricate them so we can there +are lots of techniques + + align:start position:0% +are lots of techniques + + + align:start position:0% +are lots of techniques +lots of techniques out there but we can + + align:start position:0% +lots of techniques out there but we can + + + align:start position:0% +lots of techniques out there but we can +categorize this + + align:start position:0% +categorize this + + + align:start position:0% +categorize this +in three main categories the first one + + align:start position:0% +in three main categories the first one + + + align:start position:0% +in three main categories the first one +is a full 3d fabrication when you where + + align:start position:0% +is a full 3d fabrication when you where + + + align:start position:0% +is a full 3d fabrication when you where +you create the whole 3d uh structure all + + align:start position:0% +you create the whole 3d uh structure all + + + align:start position:0% +you create the whole 3d uh structure all +at once or you can do a point by point + + align:start position:0% +at once or you can do a point by point + + + align:start position:0% +at once or you can do a point by point +fabrication where you create every + + align:start position:0% +fabrication where you create every + + + align:start position:0% +fabrication where you create every +single + + align:start position:0% +single + + + align:start position:0% +single +aspect in the crystal + + align:start position:0% +aspect in the crystal + + + align:start position:0% +aspect in the crystal +by scanning the whole 3d + + align:start position:0% +by scanning the whole 3d + + + align:start position:0% +by scanning the whole 3d +structure or you can have a layer by + + align:start position:0% +structure or you can have a layer by + + + align:start position:0% +structure or you can have a layer by +layer approach + + align:start position:0% +layer approach + + + align:start position:0% +layer approach +to make a whole 3d structure + + align:start position:0% +to make a whole 3d structure + + + align:start position:0% +to make a whole 3d structure +so first example of full 3d fabrication + + align:start position:0% +so first example of full 3d fabrication + + + align:start position:0% +so first example of full 3d fabrication +is to use colloidal particles so you can + + align:start position:0% +is to use colloidal particles so you can + + + align:start position:0% +is to use colloidal particles so you can +assemble + + align:start position:0% +assemble + + + align:start position:0% +assemble +colloidal particles like different ways + + align:start position:0% +colloidal particles like different ways + + + align:start position:0% +colloidal particles like different ways +you can either use mac you can either + + align:start position:0% +you can either use mac you can either + + + align:start position:0% +you can either use mac you can either +micromanipulate your sphere to put + + align:start position:0% +micromanipulate your sphere to put + + + align:start position:0% +micromanipulate your sphere to put +whatever sphere you want where you want + + align:start position:0% +whatever sphere you want where you want + + + align:start position:0% +whatever sphere you want where you want +or you can use a self-assembly property + + align:start position:0% +or you can use a self-assembly property + + + align:start position:0% +or you can use a self-assembly property +of colloidal particles to make a whole + + align:start position:0% +of colloidal particles to make a whole + + + align:start position:0% +of colloidal particles to make a whole +stack of particles and then you can do + + align:start position:0% +stack of particles and then you can do + + + align:start position:0% +stack of particles and then you can do +different processes to make a whole + + align:start position:0% +different processes to make a whole + + + align:start position:0% +different processes to make a whole +3d structure + + align:start position:0% +3d structure + + + align:start position:0% +3d structure +that can be used as a photonic crystal + + align:start position:0% + + + + align:start position:0% + +a second full 3d fabrication process is + + align:start position:0% +a second full 3d fabrication process is + + + align:start position:0% +a second full 3d fabrication process is +to use what's called holographic + + align:start position:0% +to use what's called holographic + + + align:start position:0% +to use what's called holographic +lithography so in this case you have + + align:start position:0% +lithography so in this case you have + + + align:start position:0% +lithography so in this case you have +four laser beams interfering + + align:start position:0% +four laser beams interfering + + + align:start position:0% +four laser beams interfering +and they create a whole 3d interference + + align:start position:0% +and they create a whole 3d interference + + + align:start position:0% +and they create a whole 3d interference +pattern that can if you stand in this + + align:start position:0% +pattern that can if you stand in this + + + align:start position:0% +pattern that can if you stand in this +into a photoresist you would have + + align:start position:0% +into a photoresist you would have + + + align:start position:0% +into a photoresist you would have +some region which are + + align:start position:0% +some region which are + + + align:start position:0% +some region which are +exposed and some not and if you develop + + align:start position:0% +exposed and some not and if you develop + + + align:start position:0% +exposed and some not and if you develop +your + + align:start position:0% +your + + + align:start position:0% +your +photoresist you would end up having a + + align:start position:0% +photoresist you would end up having a + + + align:start position:0% +photoresist you would end up having a +whole 3d structure that have been made + + align:start position:0% +whole 3d structure that have been made + + + align:start position:0% +whole 3d structure that have been made +like all + + align:start position:0% +like all + + + align:start position:0% +like all +uh like in three dimension all at once + + align:start position:0% + + + + align:start position:0% + +if you move on now to a point by point + + align:start position:0% +if you move on now to a point by point + + + align:start position:0% +if you move on now to a point by point +fabrication process we can use + + align:start position:0% +fabrication process we can use + + + align:start position:0% +fabrication process we can use +multi-photon polymerization + + align:start position:0% +multi-photon polymerization + + + align:start position:0% +multi-photon polymerization +in the sense where here you can expose a + + align:start position:0% +in the sense where here you can expose a + + + align:start position:0% +in the sense where here you can expose a +single dot + + align:start position:0% +single dot + + + align:start position:0% +single dot +exactly where you want so in this case + + align:start position:0% +exactly where you want so in this case + + + align:start position:0% +exactly where you want so in this case +if for example if you shine light with a + + align:start position:0% +if for example if you shine light with a + + + align:start position:0% +if for example if you shine light with a +very tight focus point here you can have + + align:start position:0% +very tight focus point here you can have + + + align:start position:0% +very tight focus point here you can have +a multi multiphoton polymerization in + + align:start position:0% +a multi multiphoton polymerization in + + + align:start position:0% +a multi multiphoton polymerization in +your photoresist that a single photon + + align:start position:0% +your photoresist that a single photon + + + align:start position:0% +your photoresist that a single photon +cannot achieve and so then if you scan + + align:start position:0% +cannot achieve and so then if you scan + + + align:start position:0% +cannot achieve and so then if you scan +your whole three-dimensional structure + + align:start position:0% +your whole three-dimensional structure + + + align:start position:0% +your whole three-dimensional structure +you can make whatever shape you want and + + align:start position:0% +you can make whatever shape you want and + + + align:start position:0% +you can make whatever shape you want and +this is + + align:start position:0% +this is + + + align:start position:0% +this is +this can be combined with holographic + + align:start position:0% +this can be combined with holographic + + + align:start position:0% +this can be combined with holographic +lithography for example + + align:start position:0% +lithography for example + + + align:start position:0% +lithography for example +where in the holographic lithography you + + align:start position:0% +where in the holographic lithography you + + + align:start position:0% +where in the holographic lithography you +make the whole 3d pattern and then with + + align:start position:0% +make the whole 3d pattern and then with + + + align:start position:0% +make the whole 3d pattern and then with +multiphoton primerization you can put + + align:start position:0% +multiphoton primerization you can put + + + align:start position:0% +multiphoton primerization you can put +some defects where you want or correct + + align:start position:0% +some defects where you want or correct + + + align:start position:0% +some defects where you want or correct +for errors that that could have been + + align:start position:0% +for errors that that could have been + + + align:start position:0% +for errors that that could have been +made + + align:start position:0% +made + + + align:start position:0% +made +but another promising approach is to use + + align:start position:0% +but another promising approach is to use + + + align:start position:0% +but another promising approach is to use +a layer by layer + + align:start position:0% + + + + align:start position:0% + +technique so this is an example uh this + + align:start position:0% +technique so this is an example uh this + + + align:start position:0% +technique so this is an example uh this +is called the wood pie structure as you + + align:start position:0% +is called the wood pie structure as you + + + align:start position:0% +is called the wood pie structure as you +can see so this is done + + align:start position:0% +can see so this is done + + + align:start position:0% +can see so this is done +so layer by layer where you uh pattern a + + align:start position:0% +so layer by layer where you uh pattern a + + + align:start position:0% +so layer by layer where you uh pattern a +whole two-dimensional pattern on your + + align:start position:0% +whole two-dimensional pattern on your + + + align:start position:0% +whole two-dimensional pattern on your +substrate and then + + align:start position:0% +substrate and then + + + align:start position:0% +substrate and then +you you move on building the whole stack + + align:start position:0% +you you move on building the whole stack + + + align:start position:0% +you you move on building the whole stack +and this here is a noticeable you we + + align:start position:0% +and this here is a noticeable you we + + + align:start position:0% +and this here is a noticeable you we +have a fcc + + align:start position:0% +have a fcc + + + align:start position:0% +have a fcc +crystal lattice when every other + + align:start position:0% +crystal lattice when every other + + + align:start position:0% +crystal lattice when every other +layer is shifted by half a period + + align:start position:0% + + + + align:start position:0% + +another interesting ladder is we can + + align:start position:0% +another interesting ladder is we can + + + align:start position:0% +another interesting ladder is we can +form with this layer of a layer approach + + align:start position:0% +form with this layer of a layer approach + + + align:start position:0% +form with this layer of a layer approach +is a so-called holes rod structure we + + align:start position:0% +is a so-called holes rod structure we + + + align:start position:0% +is a so-called holes rod structure we +can see here on the right + + align:start position:0% +can see here on the right + + + align:start position:0% +can see here on the right +and how you can + + align:start position:0% +and how you can + + + align:start position:0% +and how you can +make these is to use the same process of + + align:start position:0% +make these is to use the same process of + + + align:start position:0% +make these is to use the same process of +patterning each layer at a time and + + align:start position:0% +patterning each layer at a time and + + + align:start position:0% +patterning each layer at a time and +repeating the process to and you + + align:start position:0% +repeating the process to and you + + + align:start position:0% +repeating the process to and you +actually have this multiple layer + + align:start position:0% +actually have this multiple layer + + + align:start position:0% +actually have this multiple layer +on top of each other + + align:start position:0% +on top of each other + + + align:start position:0% +on top of each other +and with this technique you can also + + align:start position:0% +and with this technique you can also + + + align:start position:0% +and with this technique you can also +make defects uh in whatever layer you + + align:start position:0% +make defects uh in whatever layer you + + + align:start position:0% +make defects uh in whatever layer you +want + + align:start position:0% + + + + align:start position:0% + +you can also use a membrane stacking + + align:start position:0% +you can also use a membrane stacking + + + align:start position:0% +you can also use a membrane stacking +technique so in this case you pattern uh + + align:start position:0% +technique so in this case you pattern uh + + + align:start position:0% +technique so in this case you pattern uh +all your 2d uh + + align:start position:0% +all your 2d uh + + + align:start position:0% +all your 2d uh +structure your 2d membranes uh + + align:start position:0% +structure your 2d membranes uh + + + align:start position:0% +structure your 2d membranes uh +first and you can make whatever shape + + align:start position:0% +first and you can make whatever shape + + + align:start position:0% +first and you can make whatever shape +you want with defects or not and then + + align:start position:0% +you want with defects or not and then + + + align:start position:0% +you want with defects or not and then +you can stack them together + + align:start position:0% +you can stack them together + + + align:start position:0% +you can stack them together +using some alignment techniques + + align:start position:0% +using some alignment techniques + + + align:start position:0% +using some alignment techniques +that here is used uh + + align:start position:0% +that here is used uh + + + align:start position:0% +that here is used uh +by microspheres + + align:start position:0% +by microspheres + + + align:start position:0% +by microspheres +so basically you + + align:start position:0% +so basically you + + + align:start position:0% +so basically you +you come with all these 2d + + align:start position:0% +you come with all these 2d + + + align:start position:0% +you come with all these 2d +two-dimensional structure and you stack + + align:start position:0% +two-dimensional structure and you stack + + + align:start position:0% +two-dimensional structure and you stack +them together using this microsphere for + + align:start position:0% +them together using this microsphere for + + + align:start position:0% +them together using this microsphere for +alignment another promising technique to + + align:start position:0% +alignment another promising technique to + + + align:start position:0% +alignment another promising technique to +align and stack this structure is to use + + align:start position:0% +align and stack this structure is to use + + + align:start position:0% +align and stack this structure is to use +nanomagnets on these membranes and this + + align:start position:0% +nanomagnets on these membranes and this + + + align:start position:0% +nanomagnets on these membranes and this +memory can help you first to align + + align:start position:0% +memory can help you first to align + + + align:start position:0% +memory can help you first to align +each layer uh on the on the other and + + align:start position:0% +each layer uh on the on the other and + + + align:start position:0% +each layer uh on the on the other and +also because the magnetic force can be + + align:start position:0% +also because the magnetic force can be + + + align:start position:0% +also because the magnetic force can be +used to break uh each membrane from the + + align:start position:0% +used to break uh each membrane from the + + + align:start position:0% +used to break uh each membrane from the +from the mainframe + + align:start position:0% + + + + align:start position:0% + +and if you want to build this one of + + align:start position:0% +and if you want to build this one of + + + align:start position:0% +and if you want to build this one of +these layers we can use for + + align:start position:0% +these layers we can use for + + + align:start position:0% +these layers we can use for +this stacking uh a really promising + + align:start position:0% +this stacking uh a really promising + + + align:start position:0% +this stacking uh a really promising +technique is to use coherent diffraction + + align:start position:0% +technique is to use coherent diffraction + + + align:start position:0% +technique is to use coherent diffraction +lithography so here we + + align:start position:0% +lithography so here we + + + align:start position:0% +lithography so here we +we shine light through a mask which is a + + align:start position:0% +we shine light through a mask which is a + + + align:start position:0% +we shine light through a mask which is a +grating for example and + + align:start position:0% +grating for example and + + + align:start position:0% +grating for example and +and you have your uh you have your + + align:start position:0% +and you have your uh you have your + + + align:start position:0% +and you have your uh you have your +substrate below at a specific uh + + align:start position:0% +substrate below at a specific uh + + + align:start position:0% +substrate below at a specific uh +position a specific height below which + + align:start position:0% +position a specific height below which + + + align:start position:0% +position a specific height below which +corresponds to one of the towable plane + + align:start position:0% +corresponds to one of the towable plane + + + align:start position:0% +corresponds to one of the towable plane +for example so here you can see the + + align:start position:0% +for example so here you can see the + + + align:start position:0% +for example so here you can see the +field below the mask or you can see + + align:start position:0% +field below the mask or you can see + + + align:start position:0% +field below the mask or you can see +different double plane and here is an + + align:start position:0% +different double plane and here is an + + + align:start position:0% +different double plane and here is an +example of + + align:start position:0% +example of + + + align:start position:0% +example of +so self-imaging for grading at the first + + align:start position:0% +so self-imaging for grading at the first + + + align:start position:0% +so self-imaging for grading at the first +elbow plane + + align:start position:0% +elbow plane + + + align:start position:0% +elbow plane +so but one of the main problem is this + + align:start position:0% +so but one of the main problem is this + + + align:start position:0% +so but one of the main problem is this +2d + + align:start position:0% +2d + + + align:start position:0% +2d +layer by layer fabrication is how + + align:start position:0% +layer by layer fabrication is how + + + align:start position:0% +layer by layer fabrication is how +accurate do you need an alignment to be + + align:start position:0% +accurate do you need an alignment to be + + + align:start position:0% +accurate do you need an alignment to be +between your different 2d uh + + align:start position:0% +between your different 2d uh + + + align:start position:0% +between your different 2d uh +2d layers so that's really a big big + + align:start position:0% +2d layers so that's really a big big + + + align:start position:0% +2d layers so that's really a big big +problem in the fabrication of this 3d + + align:start position:0% +problem in the fabrication of this 3d + + + align:start position:0% +problem in the fabrication of this 3d +photonic crystal uses this layer by + + align:start position:0% +photonic crystal uses this layer by + + + align:start position:0% +photonic crystal uses this layer by +layer approach and that's why we run + + align:start position:0% +layer approach and that's why we run + + + align:start position:0% +layer approach and that's why we run +some simulation to see how accurate we + + align:start position:0% +some simulation to see how accurate we + + + align:start position:0% +some simulation to see how accurate we +should we need to be + + align:start position:0% +should we need to be + + + align:start position:0% +should we need to be +in a in this layer-by-layer approach i + + align:start position:0% +in a in this layer-by-layer approach i + + + align:start position:0% +in a in this layer-by-layer approach i +got it + + align:start position:0% +got it + + + align:start position:0% +got it +thank you + + align:start position:0% + + + + align:start position:0% + +one second + + align:start position:0% + + + + align:start position:0% + +all right thank you martin so + + align:start position:0% +all right thank you martin so + + + align:start position:0% +all right thank you martin so +one of the structures that martin + + align:start position:0% +one of the structures that martin + + + align:start position:0% +one of the structures that martin +mentioned was the diamond lattice which + + align:start position:0% +mentioned was the diamond lattice which + + + align:start position:0% +mentioned was the diamond lattice which +is just the same as the face center + + align:start position:0% +is just the same as the face center + + + align:start position:0% +is just the same as the face center +cubic but there's two atoms in the + + align:start position:0% +cubic but there's two atoms in the + + + align:start position:0% +cubic but there's two atoms in the +middle + + align:start position:0% +middle + + + align:start position:0% +middle +so what i mean by that + + align:start position:0% + + + + align:start position:0% + +is this atom and this atom this is + + align:start position:0% +is this atom and this atom this is + + + align:start position:0% +is this atom and this atom this is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +eight unit cells in this picture now + + align:start position:0% +eight unit cells in this picture now + + + align:start position:0% +eight unit cells in this picture now +this image and this image were taken + + align:start position:0% +this image and this image were taken + + + align:start position:0% +this image and this image were taken +from a program mit photonic bands which + + align:start position:0% +from a program mit photonic bands which + + + align:start position:0% +from a program mit photonic bands which +allows you to calculate the band gap in + + align:start position:0% +allows you to calculate the band gap in + + + align:start position:0% +allows you to calculate the band gap in +three-dimensional structures + + align:start position:0% +three-dimensional structures + + + align:start position:0% +three-dimensional structures +for this particular structure + + align:start position:0% +for this particular structure + + + align:start position:0% +for this particular structure +the band gap is 10.62 percent and this + + align:start position:0% +the band gap is 10.62 percent and this + + + align:start position:0% +the band gap is 10.62 percent and this +band gap is actually the range of + + align:start position:0% +band gap is actually the range of + + + align:start position:0% +band gap is actually the range of +frequencies here divided by the mid + + align:start position:0% +frequencies here divided by the mid + + + align:start position:0% +frequencies here divided by the mid +frequency so that's what gives us these + + align:start position:0% +frequency so that's what gives us these + + + align:start position:0% +frequency so that's what gives us these +percentages + + align:start position:0% +percentages + + + align:start position:0% +percentages +now + + align:start position:0% +now + + + align:start position:0% +now +one of the things that uh + + align:start position:0% +one of the things that uh + + + align:start position:0% +one of the things that uh +we notice is that it's centered about + + align:start position:0% +we notice is that it's centered about + + + align:start position:0% +we notice is that it's centered about +0.42 + + align:start position:0% +0.42 + + + align:start position:0% +0.42 +and obviously the gap is defined in this + + align:start position:0% +and obviously the gap is defined in this + + + align:start position:0% +and obviously the gap is defined in this +way + + align:start position:0% +way + + + align:start position:0% +way +what we are concerned with is + + align:start position:0% +what we are concerned with is + + + align:start position:0% +what we are concerned with is +what happens if we change this parameter + + align:start position:0% +what happens if we change this parameter + + + align:start position:0% +what happens if we change this parameter +delta so that corresponds to + + align:start position:0% +delta so that corresponds to + + + align:start position:0% +delta so that corresponds to +shifting this sphere this sphere this + + align:start position:0% +shifting this sphere this sphere this + + + align:start position:0% +shifting this sphere this sphere this +sphere and this fear by + + align:start position:0% +sphere and this fear by + + + align:start position:0% +sphere and this fear by +an amount delta in a linear direction + + align:start position:0% +an amount delta in a linear direction + + + align:start position:0% +an amount delta in a linear direction +so what we did was we looked at you know + + align:start position:0% +so what we did was we looked at you know + + + align:start position:0% +so what we did was we looked at you know +say it's 10 20 30 40 what happens to the + + align:start position:0% +say it's 10 20 30 40 what happens to the + + + align:start position:0% +say it's 10 20 30 40 what happens to the +overall band gap + + align:start position:0% +overall band gap + + + align:start position:0% +overall band gap +and so these are the simulations that i + + align:start position:0% +and so these are the simulations that i + + + align:start position:0% +and so these are the simulations that i +ran + + align:start position:0% +ran + + + align:start position:0% +ran +and you can see that at no displacement + + align:start position:0% +and you can see that at no displacement + + + align:start position:0% +and you can see that at no displacement +you've got that nice band gap + + align:start position:0% +you've got that nice band gap + + + align:start position:0% +you've got that nice band gap +and then as you shift it by ten percent + + align:start position:0% +and then as you shift it by ten percent + + + align:start position:0% +and then as you shift it by ten percent +the gap decreases substantially and as + + align:start position:0% +the gap decreases substantially and as + + + align:start position:0% +the gap decreases substantially and as +you go beyond that the gap pretty much + + align:start position:0% +you go beyond that the gap pretty much + + + align:start position:0% +you go beyond that the gap pretty much +goes away + + align:start position:0% +goes away + + + align:start position:0% +goes away +so + + align:start position:0% +so + + + align:start position:0% +so +one of the things that's curious is + + align:start position:0% +one of the things that's curious is + + + align:start position:0% +one of the things that's curious is +what's happening in this you know zero + + align:start position:0% +what's happening in this you know zero + + + align:start position:0% +what's happening in this you know zero +to say 15 percent regime so we ran a + + align:start position:0% +to say 15 percent regime so we ran a + + + align:start position:0% +to say 15 percent regime so we ran a +finer simulation to uh give us that and + + align:start position:0% +finer simulation to uh give us that and + + + align:start position:0% +finer simulation to uh give us that and +plotted the + + align:start position:0% +plotted the + + + align:start position:0% +plotted the +gap + + align:start position:0% +gap + + + align:start position:0% +gap +normalized by that maximum gap that you + + align:start position:0% +normalized by that maximum gap that you + + + align:start position:0% +normalized by that maximum gap that you +could get for those you know percent + + align:start position:0% +could get for those you know percent + + + align:start position:0% +could get for those you know percent +displacements and you can see that + + align:start position:0% +displacements and you can see that + + + align:start position:0% +displacements and you can see that +at around five percent displacement the + + align:start position:0% +at around five percent displacement the + + + align:start position:0% +at around five percent displacement the +gaps about 67 percent of what it was + + align:start position:0% +gaps about 67 percent of what it was + + + align:start position:0% +gaps about 67 percent of what it was +originally so a small displacement can + + align:start position:0% +originally so a small displacement can + + + align:start position:0% +originally so a small displacement can +substantially affect your band gap + + align:start position:0% +substantially affect your band gap + + + align:start position:0% +substantially affect your band gap +and to the extent that you may want that + + align:start position:0% +and to the extent that you may want that + + + align:start position:0% +and to the extent that you may want that +it's not necessarily a bad thing + + align:start position:0% +it's not necessarily a bad thing + + + align:start position:0% +it's not necessarily a bad thing +but you + + align:start position:0% +but you + + + align:start position:0% +but you +need to be aware of it when you're + + align:start position:0% +need to be aware of it when you're + + + align:start position:0% +need to be aware of it when you're +engineering these things + + align:start position:0% +engineering these things + + + align:start position:0% +engineering these things +so + + align:start position:0% +so + + + align:start position:0% +so +these are just some numbers that you + + align:start position:0% +these are just some numbers that you + + + align:start position:0% +these are just some numbers that you +know kind of give you a better handle on + + align:start position:0% +know kind of give you a better handle on + + + align:start position:0% +know kind of give you a better handle on +what that graph means but you know i + + align:start position:0% +what that graph means but you know i + + + align:start position:0% +what that graph means but you know i +like this one the best if you want to + + align:start position:0% +like this one the best if you want to + + + align:start position:0% +like this one the best if you want to +keep your gap above 10 or 95 percent + + align:start position:0% +keep your gap above 10 or 95 percent + + + align:start position:0% +keep your gap above 10 or 95 percent +then that's really a displacement of + + align:start position:0% +then that's really a displacement of + + + align:start position:0% +then that's really a displacement of +around one to two percent which is + + align:start position:0% +around one to two percent which is + + + align:start position:0% +around one to two percent which is +pretty small + + align:start position:0% +pretty small + + + align:start position:0% +pretty small +so a real example of this you know in + + align:start position:0% +so a real example of this you know in + + + align:start position:0% +so a real example of this you know in +the telecom + + align:start position:0% +the telecom + + + align:start position:0% +the telecom +wavelengths and frequencies + + align:start position:0% +wavelengths and frequencies + + + align:start position:0% +wavelengths and frequencies +is you know frequency is 1.9 times 10 to + + align:start position:0% +is you know frequency is 1.9 times 10 to + + + align:start position:0% +is you know frequency is 1.9 times 10 to +the 14 hertz + + align:start position:0% +the 14 hertz + + + align:start position:0% +the 14 hertz +and if you look at the displacement in + + align:start position:0% +and if you look at the displacement in + + + align:start position:0% +and if you look at the displacement in +nanometers now so we've multiplied it by + + align:start position:0% +nanometers now so we've multiplied it by + + + align:start position:0% +nanometers now so we've multiplied it by +our lattice spacing in + + align:start position:0% +our lattice spacing in + + + align:start position:0% +our lattice spacing in +sebastian slides this was the r + + align:start position:0% +sebastian slides this was the r + + + align:start position:0% +sebastian slides this was the r +but in this case it's 663 nanometers you + + align:start position:0% +but in this case it's 663 nanometers you + + + align:start position:0% +but in this case it's 663 nanometers you +multiply the percent by that number you + + align:start position:0% +multiply the percent by that number you + + + align:start position:0% +multiply the percent by that number you +find that you know the bandwidth + + align:start position:0% +find that you know the bandwidth + + + align:start position:0% +find that you know the bandwidth +decreases rapidly as you go out to like + + align:start position:0% +decreases rapidly as you go out to like + + + align:start position:0% +decreases rapidly as you go out to like +you know 40 or 60 nanometers the + + align:start position:0% +you know 40 or 60 nanometers the + + + align:start position:0% +you know 40 or 60 nanometers the +bandwidth is dropped almost 50 percent + + align:start position:0% +bandwidth is dropped almost 50 percent + + + align:start position:0% +bandwidth is dropped almost 50 percent +so in this case + + align:start position:0% +so in this case + + + align:start position:0% +so in this case +we might want to narrow the band gap if + + align:start position:0% +we might want to narrow the band gap if + + + align:start position:0% +we might want to narrow the band gap if +we want to have like a very very uh + + align:start position:0% +we want to have like a very very uh + + + align:start position:0% +we want to have like a very very uh +narrow band filter but we might want to + + align:start position:0% +narrow band filter but we might want to + + + align:start position:0% +narrow band filter but we might want to +have lots of frequencies being reflected + + align:start position:0% +have lots of frequencies being reflected + + + align:start position:0% +have lots of frequencies being reflected +from this particular crystal at which + + align:start position:0% +from this particular crystal at which + + + align:start position:0% +from this particular crystal at which +point we'd want to be operating over + + align:start position:0% +point we'd want to be operating over + + + align:start position:0% +point we'd want to be operating over +here + + align:start position:0% +here + + + align:start position:0% +here +so i hope that this gives you a sense + + align:start position:0% +so i hope that this gives you a sense + + + align:start position:0% +so i hope that this gives you a sense +for how important misalignment is and + + align:start position:0% +for how important misalignment is and + + + align:start position:0% +for how important misalignment is and +how you can use it to engineer your band + + align:start position:0% +how you can use it to engineer your band + + + align:start position:0% +how you can use it to engineer your band +gap appropriately + + align:start position:0% +gap appropriately + + + align:start position:0% +gap appropriately +thank you + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +one of the things that was mentioned was + + align:start position:0% +one of the things that was mentioned was + + + align:start position:0% +one of the things that was mentioned was +that certain fabrication techniques will + + align:start position:0% +that certain fabrication techniques will + + + align:start position:0% +that certain fabrication techniques will +allow you to put defects in why would + + align:start position:0% +allow you to put defects in why would + + + align:start position:0% +allow you to put defects in why would +you want is it the same principle that + + align:start position:0% +you want is it the same principle that + + + align:start position:0% +you want is it the same principle that +you want + + align:start position:0% +you want + + + align:start position:0% +you want +so + + align:start position:0% +so + + + align:start position:0% +so +if you + + align:start position:0% +if you + + + align:start position:0% +if you +um if you add defects into the photonic + + align:start position:0% +um if you add defects into the photonic + + + align:start position:0% +um if you add defects into the photonic +crystal then essentially you make a pass + + align:start position:0% +crystal then essentially you make a pass + + + align:start position:0% +crystal then essentially you make a pass +band in the band gap and light can + + align:start position:0% +band in the band gap and light can + + + align:start position:0% +band in the band gap and light can +propagate if it's like a line defect you + + align:start position:0% +propagate if it's like a line defect you + + + align:start position:0% +propagate if it's like a line defect you +make a waveguide + + align:start position:0% +make a waveguide + + + align:start position:0% +make a waveguide +if it's like a point defect then light + + align:start position:0% +if it's like a point defect then light + + + align:start position:0% +if it's like a point defect then light +will resonate inside that defect and you + + align:start position:0% +will resonate inside that defect and you + + + align:start position:0% +will resonate inside that defect and you +know there's obviously other structures + + align:start position:0% +know there's obviously other structures + + + align:start position:0% +know there's obviously other structures +you could do but those are two of the + + align:start position:0% +you could do but those are two of the + + + align:start position:0% +you could do but those are two of the +simpler ones + + align:start position:0% + + + + align:start position:0% + +is this for a given thickness of + + align:start position:0% +is this for a given thickness of + + + align:start position:0% +is this for a given thickness of +photonic crystal or is it like an + + align:start position:0% +photonic crystal or is it like an + + + align:start position:0% +photonic crystal or is it like an +infinite photonic crystal this is + + align:start position:0% +infinite photonic crystal this is + + + align:start position:0% +infinite photonic crystal this is +actually one of my big caveats about the + + align:start position:0% +actually one of my big caveats about the + + + align:start position:0% +actually one of my big caveats about the +simulation so + + align:start position:0% +simulation so + + + align:start position:0% +simulation so +this software assumes that it's + + align:start position:0% +this software assumes that it's + + + align:start position:0% +this software assumes that it's +infinitely periodic and so + + align:start position:0% +infinitely periodic and so + + + align:start position:0% +infinitely periodic and so +what i've done here + + align:start position:0% +what i've done here + + + align:start position:0% +what i've done here +is actually shifted every other layer + + align:start position:0% +is actually shifted every other layer + + + align:start position:0% +is actually shifted every other layer +not just a single layer and that's an + + align:start position:0% +not just a single layer and that's an + + + align:start position:0% +not just a single layer and that's an +artifact of the simulation software if i + + align:start position:0% +artifact of the simulation software if i + + + align:start position:0% +artifact of the simulation software if i +wanted to try and model just one layer + + align:start position:0% +wanted to try and model just one layer + + + align:start position:0% +wanted to try and model just one layer +it becomes much much more complicated + + align:start position:0% +it becomes much much more complicated + + + align:start position:0% +it becomes much much more complicated +but yeah it is infinite in extent and + + align:start position:0% +but yeah it is infinite in extent and + + + align:start position:0% +but yeah it is infinite in extent and +one of the things that the holographic + + align:start position:0% +one of the things that the holographic + + + align:start position:0% +one of the things that the holographic +lithography is limited by is the actual + + align:start position:0% +lithography is limited by is the actual + + + align:start position:0% +lithography is limited by is the actual +thickness of the photoresist that they + + align:start position:0% +thickness of the photoresist that they + + + align:start position:0% +thickness of the photoresist that they +can expose because after a little while + + align:start position:0% +can expose because after a little while + + + align:start position:0% +can expose because after a little while +the light stops interfering in the right + + align:start position:0% +the light stops interfering in the right + + + align:start position:0% +the light stops interfering in the right +way and you don't get that interference + + align:start position:0% +way and you don't get that interference + + + align:start position:0% +way and you don't get that interference +pattern that you want anymore + + align:start position:0% + + + + align:start position:0% + +in real life how could such a defect + + align:start position:0% +in real life how could such a defect + + + align:start position:0% +in real life how could such a defect +come about + + align:start position:0% +come about + + + align:start position:0% +come about +so it's displacement + + align:start position:0% +so it's displacement + + + align:start position:0% +so it's displacement +yeah there's there's a couple ways right + + align:start position:0% +yeah there's there's a couple ways right + + + align:start position:0% +yeah there's there's a couple ways right +now + + align:start position:0% +now + + + align:start position:0% +now +one of the things that um + + align:start position:0% +one of the things that um + + + align:start position:0% +one of the things that um +martin was showing was this coherent + + align:start position:0% +martin was showing was this coherent + + + align:start position:0% +martin was showing was this coherent +diffraction lithography stuff and i'm + + align:start position:0% +diffraction lithography stuff and i'm + + + align:start position:0% +diffraction lithography stuff and i'm +going to talk about it a little bit + + align:start position:0% +going to talk about it a little bit + + + align:start position:0% +going to talk about it a little bit +because i know very well + + align:start position:0% +because i know very well + + + align:start position:0% +because i know very well +so you can imagine you know if you + + align:start position:0% +so you can imagine you know if you + + + align:start position:0% +so you can imagine you know if you +had your substrate at an angle here + + align:start position:0% +had your substrate at an angle here + + + align:start position:0% +had your substrate at an angle here +you know you pass through a few tablet + + align:start position:0% +you know you pass through a few tablet + + + align:start position:0% +you know you pass through a few tablet +planes and so the actual + + align:start position:0% +planes and so the actual + + + align:start position:0% +planes and so the actual +shape of your grating + + align:start position:0% +shape of your grating + + + align:start position:0% +shape of your grating +wouldn't be just periodic there'd be + + align:start position:0% +wouldn't be just periodic there'd be + + + align:start position:0% +wouldn't be just periodic there'd be +regions where you'd go to frequency + + align:start position:0% +regions where you'd go to frequency + + + align:start position:0% +regions where you'd go to frequency +doubling there'd be regions where you + + align:start position:0% +doubling there'd be regions where you + + + align:start position:0% +doubling there'd be regions where you +didn't + + align:start position:0% +didn't + + + align:start position:0% +didn't +so that alignment capability is really + + align:start position:0% +so that alignment capability is really + + + align:start position:0% +so that alignment capability is really +an important thing and if you imagine + + align:start position:0% +an important thing and if you imagine + + + align:start position:0% +an important thing and if you imagine +stacking in the membrane stacking sense + + align:start position:0% +stacking in the membrane stacking sense + + + align:start position:0% +stacking in the membrane stacking sense +these printed patterns on top of each + + align:start position:0% +these printed patterns on top of each + + + align:start position:0% +these printed patterns on top of each +other you have to be able to align those + + align:start position:0% +other you have to be able to align those + + + align:start position:0% +other you have to be able to align those +patterns relative to each other and if + + align:start position:0% +patterns relative to each other and if + + + align:start position:0% +patterns relative to each other and if +your alignment is off by say 25 + + align:start position:0% +your alignment is off by say 25 + + + align:start position:0% +your alignment is off by say 25 +nanometers then you get something like + + align:start position:0% +nanometers then you get something like + + + align:start position:0% +nanometers then you get something like + + align:start position:0% + + + align:start position:0% +decrease in your band gap + + align:start position:0% +decrease in your band gap + + + align:start position:0% +decrease in your band gap +so one of the examples of misalignment + + align:start position:0% +so one of the examples of misalignment + + + align:start position:0% +so one of the examples of misalignment +is actually in the stacking part of the + + align:start position:0% +is actually in the stacking part of the + + + align:start position:0% +is actually in the stacking part of the +fabrication and one of the things that + + align:start position:0% +fabrication and one of the things that + + + align:start position:0% +fabrication and one of the things that +you know in this particular case this + + align:start position:0% +you know in this particular case this + + + align:start position:0% +you know in this particular case this +stacking is all dependent on how good + + align:start position:0% +stacking is all dependent on how good + + + align:start position:0% +stacking is all dependent on how good +these spheres are + + align:start position:0% +these spheres are + + + align:start position:0% +these spheres are +you know so the misalignment's not i + + align:start position:0% +you know so the misalignment's not i + + + align:start position:0% +you know so the misalignment's not i +don't believe it was reported in this + + align:start position:0% +don't believe it was reported in this + + + align:start position:0% +don't believe it was reported in this +paper but you know + + align:start position:0% +paper but you know + + + align:start position:0% +paper but you know +it could be 20 or 30 nanometers they + + align:start position:0% +it could be 20 or 30 nanometers they + + + align:start position:0% +it could be 20 or 30 nanometers they +don't say + + align:start position:0% +don't say + + + align:start position:0% +don't say +and so that's where the misalignment + + align:start position:0% +and so that's where the misalignment + + + align:start position:0% +and so that's where the misalignment +comes from but you know in ming howe's + + align:start position:0% +comes from but you know in ming howe's + + + align:start position:0% +comes from but you know in ming howe's +work + + align:start position:0% +work + + + align:start position:0% +work +in this one the misalignment comes from + + align:start position:0% +in this one the misalignment comes from + + + align:start position:0% +in this one the misalignment comes from +the e-beam + + align:start position:0% +the e-beam + + + align:start position:0% +the e-beam +right so as the e-beam is writing each + + align:start position:0% +right so as the e-beam is writing each + + + align:start position:0% +right so as the e-beam is writing each +one of these uh + + align:start position:0% +one of these uh + + + align:start position:0% +one of these uh +each one of these hole layers or each + + align:start position:0% +each one of these hole layers or each + + + align:start position:0% +each one of these hole layers or each +one of these rod layers there's a + + align:start position:0% +one of these rod layers there's a + + + align:start position:0% +one of these rod layers there's a +certain few nanometers off error that + + align:start position:0% +certain few nanometers off error that + + + align:start position:0% +certain few nanometers off error that +you know it misplaces a rod or it + + align:start position:0% +you know it misplaces a rod or it + + + align:start position:0% +you know it misplaces a rod or it +misplaces a hole + + align:start position:0% +misplaces a hole + + + align:start position:0% +misplaces a hole +so i guess the answer to your question + + align:start position:0% +so i guess the answer to your question + + + align:start position:0% +so i guess the answer to your question +is that there's a lot of different ways + + align:start position:0% +is that there's a lot of different ways + + + align:start position:0% +is that there's a lot of different ways +that misalignment can happen but it's + + align:start position:0% +that misalignment can happen but it's + + + align:start position:0% +that misalignment can happen but it's +controlling that misalignment + + align:start position:0% +controlling that misalignment + + + align:start position:0% +controlling that misalignment +and if we use diffractive optics we can + + align:start position:0% +and if we use diffractive optics we can + + + align:start position:0% +and if we use diffractive optics we can +control it very well + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so how does a crystal that's designed + + align:start position:0% +so how does a crystal that's designed + + + align:start position:0% +so how does a crystal that's designed +for a wider band gap but like has + + align:start position:0% +for a wider band gap but like has + + + align:start position:0% +for a wider band gap but like has +misalignment so you have an effectively + + align:start position:0% +misalignment so you have an effectively + + + align:start position:0% +misalignment so you have an effectively +shorter one how does that compare to one + + align:start position:0% +shorter one how does that compare to one + + + align:start position:0% +shorter one how does that compare to one +that's actually designed for the + + align:start position:0% +that's actually designed for the + + + align:start position:0% +that's actually designed for the +smaller band gap and is accurately + + align:start position:0% +smaller band gap and is accurately + + + align:start position:0% +smaller band gap and is accurately +aligned + + align:start position:0% +aligned + + + align:start position:0% +aligned +so + + align:start position:0% +so + + + align:start position:0% +so +i think the answer to the question is if + + align:start position:0% +i think the answer to the question is if + + + align:start position:0% +i think the answer to the question is if +i were designing it + + align:start position:0% +i were designing it + + + align:start position:0% +i were designing it +i'd want to go with the one that's + + align:start position:0% +i'd want to go with the one that's + + + align:start position:0% +i'd want to go with the one that's +designed to have a smaller band gap + + align:start position:0% +designed to have a smaller band gap + + + align:start position:0% +designed to have a smaller band gap +without misalignment than one that's + + align:start position:0% +without misalignment than one that's + + + align:start position:0% +without misalignment than one that's +designed to have a smaller gap with + + align:start position:0% +designed to have a smaller gap with + + + align:start position:0% +designed to have a smaller gap with +misalignment like i wouldn't + + align:start position:0% +misalignment like i wouldn't + + + align:start position:0% +misalignment like i wouldn't +screw up my pattern to make the band gap + + align:start position:0% +screw up my pattern to make the band gap + + + align:start position:0% +screw up my pattern to make the band gap +get smaller i'd try and design it to + + align:start position:0% +get smaller i'd try and design it to + + + align:start position:0% +get smaller i'd try and design it to +have that band gap + + align:start position:0% + + + + align:start position:0% + +okay \ No newline at end of file diff --git a/WIKsL9tPoAE.txt b/WIKsL9tPoAE.txt new file mode 100644 index 0000000000000000000000000000000000000000..2bbc5b2927461e19ac0a1a31713a37fdd0b65e68 --- /dev/null +++ b/WIKsL9tPoAE.txt @@ -0,0 +1,1171 @@ +align:start position:0% + +we'll call from our last video that it + + align:start position:0% +we'll call from our last video that it + + + align:start position:0% +we'll call from our last video that it +was impossible for us to use + + align:start position:0% +was impossible for us to use + + + align:start position:0% +was impossible for us to use +hierarchical clustering because of the + + align:start position:0% +hierarchical clustering because of the + + + align:start position:0% +hierarchical clustering because of the +high resolution of our image so in this + + align:start position:0% +high resolution of our image so in this + + + align:start position:0% +high resolution of our image so in this +video we will try to segment the MRI + + align:start position:0% +video we will try to segment the MRI + + + align:start position:0% +video we will try to segment the MRI +image using the canyons clustering + + align:start position:0% +image using the canyons clustering + + + align:start position:0% +image using the canyons clustering +algorithm the first step in k-means + + align:start position:0% +algorithm the first step in k-means + + + align:start position:0% +algorithm the first step in k-means +clustering involves specifying the + + align:start position:0% +clustering involves specifying the + + + align:start position:0% +clustering involves specifying the +number of clusters k but how do we + + align:start position:0% +number of clusters k but how do we + + + align:start position:0% +number of clusters k but how do we +select K while our clusters would + + align:start position:0% +select K while our clusters would + + + align:start position:0% +select K while our clusters would +ideally assign each point in the image + + align:start position:0% +ideally assign each point in the image + + + align:start position:0% +ideally assign each point in the image +to a tissue class or a particular + + align:start position:0% +to a tissue class or a particular + + + align:start position:0% +to a tissue class or a particular +substance for instance gray matter or + + align:start position:0% +substance for instance gray matter or + + + align:start position:0% +substance for instance gray matter or +white matter and so on and these + + align:start position:0% +white matter and so on and these + + + align:start position:0% +white matter and so on and these +substances are known to the medical + + align:start position:0% +substances are known to the medical + + + align:start position:0% +substances are known to the medical +community so setting the number of + + align:start position:0% +community so setting the number of + + + align:start position:0% +community so setting the number of +clusters depends on exactly what you are + + align:start position:0% +clusters depends on exactly what you are + + + align:start position:0% +clusters depends on exactly what you are +trying to extract from the image for the + + align:start position:0% +trying to extract from the image for the + + + align:start position:0% +trying to extract from the image for the +sake of our example let's set the number + + align:start position:0% +sake of our example let's set the number + + + align:start position:0% +sake of our example let's set the number +of clusters here K to 5 and since the + + align:start position:0% +of clusters here K to 5 and since the + + + align:start position:0% +of clusters here K to 5 and since the +k-means clustering algorithm starts by + + align:start position:0% +k-means clustering algorithm starts by + + + align:start position:0% +k-means clustering algorithm starts by +randomly assigning points to clusters we + + align:start position:0% +randomly assigning points to clusters we + + + align:start position:0% +randomly assigning points to clusters we +should set the seed so that we all + + align:start position:0% +should set the seed so that we all + + + align:start position:0% +should set the seed so that we all +obtain the same clusters so let's + + align:start position:0% +obtain the same clusters so let's + + + align:start position:0% +obtain the same clusters so let's +dissect that seed and give it a value of + + align:start position:0% +dissect that seed and give it a value of + + + align:start position:0% +dissect that seed and give it a value of +1/2 of the k-means clustering algorithm + + align:start position:0% +1/2 of the k-means clustering algorithm + + + align:start position:0% +1/2 of the k-means clustering algorithm +or KMC in short we need to use the + + align:start position:0% +or KMC in short we need to use the + + + align:start position:0% +or KMC in short we need to use the +k-means function in our and the first + + align:start position:0% +k-means function in our and the first + + + align:start position:0% +k-means function in our and the first +input is whatever we are trying to + + align:start position:0% +input is whatever we are trying to + + + align:start position:0% +input is whatever we are trying to +cluster in this case it is the healthy + + align:start position:0% +cluster in this case it is the healthy + + + align:start position:0% +cluster in this case it is the healthy +vector the second argument is the number + + align:start position:0% +vector the second argument is the number + + + align:start position:0% +vector the second argument is the number +of clusters and we can specify it using + + align:start position:0% +of clusters and we can specify it using + + + align:start position:0% +of clusters and we can specify it using +the argument centers and that would be + + align:start position:0% +the argument centers and that would be + + + align:start position:0% +the argument centers and that would be +equal to K and then finally since the + + align:start position:0% +equal to K and then finally since the + + + align:start position:0% +equal to K and then finally since the +k-means is an iterative method that + + align:start position:0% +k-means is an iterative method that + + + align:start position:0% +k-means is an iterative method that +could take very long to converge we need + + align:start position:0% +could take very long to converge we need + + + align:start position:0% +could take very long to converge we need +to set a maximum number of iterations + + align:start position:0% +to set a maximum number of iterations + + + align:start position:0% +to set a maximum number of iterations +and we can do this by typing by chopped + + align:start position:0% +and we can do this by typing by chopped + + + align:start position:0% +and we can do this by typing by chopped +Max and give it for instance the value + + align:start position:0% +Max and give it for instance the value + + + align:start position:0% +Max and give it for instance the value +thousand and now let's run the k-means + + align:start position:0% +thousand and now let's run the k-means + + + align:start position:0% +thousand and now let's run the k-means +algorithm the k-means algorithm is + + align:start position:0% +algorithm the k-means algorithm is + + + align:start position:0% +algorithm the k-means algorithm is +actually quite fast even though we have + + align:start position:0% +actually quite fast even though we have + + + align:start position:0% +actually quite fast even though we have +a high-resolution image now to see the + + align:start position:0% +a high-resolution image now to see the + + + align:start position:0% +a high-resolution image now to see the +result of the k-means clustering + + align:start position:0% +result of the k-means clustering + + + align:start position:0% +result of the k-means clustering +algorithm we can output the structure of + + align:start position:0% +algorithm we can output the structure of + + + align:start position:0% +algorithm we can output the structure of +the KFC variable the first thing most + + align:start position:0% +the KFC variable the first thing most + + + align:start position:0% +the KFC variable the first thing most +important piece of information that we + + align:start position:0% +important piece of information that we + + + align:start position:0% +important piece of information that we +get is the cluster vector which assigns + + align:start position:0% +get is the cluster vector which assigns + + + align:start position:0% +get is the cluster vector which assigns +each intensity value in the healthy that + + align:start position:0% +each intensity value in the healthy that + + + align:start position:0% +each intensity value in the healthy that +to a cluster in this case it will be + + align:start position:0% +to a cluster in this case it will be + + + align:start position:0% +to a cluster in this case it will be +given them values one through five since + + align:start position:0% +given them values one through five since + + + align:start position:0% +given them values one through five since +we have five clusters now recall that to + + align:start position:0% +we have five clusters now recall that to + + + align:start position:0% +we have five clusters now recall that to +output the segmented image we need to + + align:start position:0% +output the segmented image we need to + + + align:start position:0% +output the segmented image we need to +extract this vector the way to do this + + align:start position:0% +extract this vector the way to do this + + + align:start position:0% +extract this vector the way to do this +is by using the dollar notation for + + align:start position:0% +is by using the dollar notation for + + + align:start position:0% +is by using the dollar notation for +instance let us define healthy clusters + + align:start position:0% +instance let us define healthy clusters + + + align:start position:0% +instance let us define healthy clusters +and then set it equal to K and C dollar + + align:start position:0% +and then set it equal to K and C dollar + + + align:start position:0% +and then set it equal to K and C dollar +sign cluster and what we're basically + + align:start position:0% +sign cluster and what we're basically + + + align:start position:0% +sign cluster and what we're basically +doing here is that we are taking the + + align:start position:0% +doing here is that we are taking the + + + align:start position:0% +doing here is that we are taking the +information extracting the information + + align:start position:0% +information extracting the information + + + align:start position:0% +information extracting the information +of the cluster vector and putting it in + + align:start position:0% +of the cluster vector and putting it in + + + align:start position:0% +of the cluster vector and putting it in +the new variable that is called healthy + + align:start position:0% +the new variable that is called healthy + + + align:start position:0% +the new variable that is called healthy +clusters now how can we obtain the mean + + align:start position:0% +clusters now how can we obtain the mean + + + align:start position:0% +clusters now how can we obtain the mean +intensity value within each of our five + + align:start position:0% +intensity value within each of our five + + + align:start position:0% +intensity value within each of our five +clusters in hierarchical clustering we + + align:start position:0% +clusters in hierarchical clustering we + + + align:start position:0% +clusters in hierarchical clustering we +needed to do some manual work and use + + align:start position:0% +needed to do some manual work and use + + + align:start position:0% +needed to do some manual work and use +the T apply function to extract this + + align:start position:0% +the T apply function to extract this + + + align:start position:0% +the T apply function to extract this +information in this case we have the + + align:start position:0% +information in this case we have the + + + align:start position:0% +information in this case we have the +answers ready under the vector centers + + align:start position:0% +answers ready under the vector centers + + + align:start position:0% +answers ready under the vector centers +in fact for instance the mean intensity + + align:start position:0% +in fact for instance the mean intensity + + + align:start position:0% +in fact for instance the mean intensity +value of the first cluster is 0.40 a + + align:start position:0% +value of the first cluster is 0.40 a + + + align:start position:0% +value of the first cluster is 0.40 a +then the mean intensity value of the + + align:start position:0% +then the mean intensity value of the + + + align:start position:0% +then the mean intensity value of the +last cluster is 0.18 we can also extract + + align:start position:0% +last cluster is 0.18 we can also extract + + + align:start position:0% +last cluster is 0.18 we can also extract +this information using the dollar sign + + align:start position:0% +this information using the dollar sign + + + align:start position:0% +this information using the dollar sign +for instance KFC dollar sign centers and + + align:start position:0% +for instance KFC dollar sign centers and + + + align:start position:0% +for instance KFC dollar sign centers and +then between brackets the index to this + + align:start position:0% +then between brackets the index to this + + + align:start position:0% +then between brackets the index to this +should give us the mean intensity value + + align:start position:0% +should give us the mean intensity value + + + align:start position:0% +should give us the mean intensity value +of the second cluster which is 0.1 and + + align:start position:0% +of the second cluster which is 0.1 and + + + align:start position:0% +of the second cluster which is 0.1 and +indeed this is what we obtained before + + align:start position:0% +indeed this is what we obtained before + + + align:start position:0% +indeed this is what we obtained before +we move on I would like to point your + + align:start position:0% +we move on I would like to point your + + + align:start position:0% +we move on I would like to point your +attention to one last interesting piece + + align:start position:0% +attention to one last interesting piece + + + align:start position:0% +attention to one last interesting piece +of information that we can get here and + + align:start position:0% +of information that we can get here and + + + align:start position:0% +of information that we can get here and +that is the size of the cluster for + + align:start position:0% +that is the size of the cluster for + + + align:start position:0% +that is the size of the cluster for +instance the largest cluster that we + + align:start position:0% +instance the largest cluster that we + + + align:start position:0% +instance the largest cluster that we +have is the third one which combines + + align:start position:0% +have is the third one which combines + + + align:start position:0% +have is the third one which combines +133,000 values in it and interestingly + + align:start position:0% +133,000 values in it and interestingly + + + align:start position:0% +133,000 values in it and interestingly +it's the one that has the smallest mean + + align:start position:0% +it's the one that has the smallest mean + + + align:start position:0% +it's the one that has the smallest mean +intensity value which means that it + + align:start position:0% +intensity value which means that it + + + align:start position:0% +intensity value which means that it +corresponds to the darkest shade in our + + align:start position:0% +corresponds to the darkest shade in our + + + align:start position:0% +corresponds to the darkest shade in our +image actually if we look at all the + + align:start position:0% +image actually if we look at all the + + + align:start position:0% +image actually if we look at all the +mean intensity values we can see that + + align:start position:0% +mean intensity values we can see that + + + align:start position:0% +mean intensity values we can see that +they're all less than 0.5 so they're all + + align:start position:0% +they're all less than 0.5 so they're all + + + align:start position:0% +they're all less than 0.5 so they're all +pretty close to 0 and this means that + + align:start position:0% +pretty close to 0 and this means that + + + align:start position:0% +pretty close to 0 and this means that +our image is pretty dark if we look at + + align:start position:0% +our image is pretty dark if we look at + + + align:start position:0% +our image is pretty dark if we look at +our image again it's indeed very dark + + align:start position:0% +our image again it's indeed very dark + + + align:start position:0% +our image again it's indeed very dark +and we have very few points that are + + align:start position:0% +and we have very few points that are + + + align:start position:0% +and we have very few points that are +now the exciting part + + align:start position:0% +now the exciting part + + + align:start position:0% +now the exciting part +let us output the segmented image and + + align:start position:0% +let us output the segmented image and + + + align:start position:0% +let us output the segmented image and +see what we get + + align:start position:0% +see what we get + + + align:start position:0% +see what we get +recall that we first need to convert the + + align:start position:0% +recall that we first need to convert the + + + align:start position:0% +recall that we first need to convert the +vector healthy clusters to a matrix to + + align:start position:0% +vector healthy clusters to a matrix to + + + align:start position:0% +vector healthy clusters to a matrix to +do this we will use the dimension + + align:start position:0% +do this we will use the dimension + + + align:start position:0% +do this we will use the dimension +function that takes an input the healthy + + align:start position:0% +function that takes an input the healthy + + + align:start position:0% +function that takes an input the healthy +clusters vector and now we're going to + + align:start position:0% +clusters vector and now we're going to + + + align:start position:0% +clusters vector and now we're going to +turn it into a matrix so we have to + + align:start position:0% +turn it into a matrix so we have to + + + align:start position:0% +turn it into a matrix so we have to +specify using the combined function the + + align:start position:0% +specify using the combined function the + + + align:start position:0% +specify using the combined function the +number of rows and the number of columns + + align:start position:0% +number of rows and the number of columns + + + align:start position:0% +number of rows and the number of columns +that we want we should make sure that it + + align:start position:0% +that we want we should make sure that it + + + align:start position:0% +that we want we should make sure that it +corresponds to the same size as the + + align:start position:0% +corresponds to the same size as the + + + align:start position:0% +corresponds to the same size as the +healthy matrix and since we forgot the + + align:start position:0% +healthy matrix and since we forgot the + + + align:start position:0% +healthy matrix and since we forgot the +number of rows and the number of columns + + align:start position:0% +number of rows and the number of columns + + + align:start position:0% +number of rows and the number of columns +and be healthy matrix we can simply use + + align:start position:0% +and be healthy matrix we can simply use + + + align:start position:0% +and be healthy matrix we can simply use +the n row and M call function to get + + align:start position:0% +the n row and M call function to get + + + align:start position:0% +the n row and M call function to get +them so the first input right now would + + align:start position:0% +them so the first input right now would + + + align:start position:0% +them so the first input right now would +be n row of healthy matrix and then the + + align:start position:0% +be n row of healthy matrix and then the + + + align:start position:0% +be n row of healthy matrix and then the +second input would be the number of + + align:start position:0% +second input would be the number of + + + align:start position:0% +second input would be the number of +columns of the healthy matrix and now we + + align:start position:0% +columns of the healthy matrix and now we + + + align:start position:0% +columns of the healthy matrix and now we +are assigning these numbers of rows and + + align:start position:0% +are assigning these numbers of rows and + + + align:start position:0% +are assigning these numbers of rows and +columns to our new matrix healthy + + align:start position:0% +columns to our new matrix healthy + + + align:start position:0% +columns to our new matrix healthy +clusters and now we can visualize our + + align:start position:0% +clusters and now we can visualize our + + + align:start position:0% +clusters and now we can visualize our +clusters by using the function image + + align:start position:0% +clusters by using the function image + + + align:start position:0% +clusters by using the function image +which takes as an input the healthy + + align:start position:0% +which takes as an input the healthy + + + align:start position:0% +which takes as an input the healthy +clusters matrix then let's turn off the + + align:start position:0% +clusters matrix then let's turn off the + + + align:start position:0% +clusters matrix then let's turn off the +axes and then let's be creative and use + + align:start position:0% +axes and then let's be creative and use + + + align:start position:0% +axes and then let's be creative and use +a fancy color scheme well going to + + align:start position:0% +a fancy color scheme well going to + + + align:start position:0% +a fancy color scheme well going to +invoke for color here the rainbow + + align:start position:0% +invoke for color here the rainbow + + + align:start position:0% +invoke for color here the rainbow +palette and on and the rainbow fat + + align:start position:0% +palette and on and the rainbow fat + + + align:start position:0% +palette and on and the rainbow fat +select or the function rainbow takes as + + align:start position:0% +select or the function rainbow takes as + + + align:start position:0% +select or the function rainbow takes as +an input the number of colors that we + + align:start position:0% +an input the number of colors that we + + + align:start position:0% +an input the number of colors that we +want in this case the number of colors + + align:start position:0% +want in this case the number of colors + + + align:start position:0% +want in this case the number of colors +would correspond to the number of + + align:start position:0% +would correspond to the number of + + + align:start position:0% +would correspond to the number of +clusters so the input would be K and now + + align:start position:0% +clusters so the input would be K and now + + + align:start position:0% +clusters so the input would be K and now +let's output the segmented image going + + align:start position:0% +let's output the segmented image going + + + align:start position:0% +let's output the segmented image going +back to the graphics window we see that + + align:start position:0% +back to the graphics window we see that + + + align:start position:0% +back to the graphics window we see that +the k-means algorithm was able to + + align:start position:0% +the k-means algorithm was able to + + + align:start position:0% +the k-means algorithm was able to +segment the image in five different + + align:start position:0% +segment the image in five different + + + align:start position:0% +segment the image in five different +clusters more refinement maybe needs to + + align:start position:0% +clusters more refinement maybe needs to + + + align:start position:0% +clusters more refinement maybe needs to +be made to our clustering algorithm to + + align:start position:0% +be made to our clustering algorithm to + + + align:start position:0% +be made to our clustering algorithm to +appropriately capture all the anatomical + + align:start position:0% +appropriately capture all the anatomical + + + align:start position:0% +appropriately capture all the anatomical +structures but this seems like a good + + align:start position:0% +structures but this seems like a good + + + align:start position:0% +structures but this seems like a good +starting point the question now is can + + align:start position:0% +starting point the question now is can + + + align:start position:0% +starting point the question now is can +we use the clusters or the classes found + + align:start position:0% +we use the clusters or the classes found + + + align:start position:0% +we use the clusters or the classes found +by our k-means algorithm + + align:start position:0% +by our k-means algorithm + + + align:start position:0% +by our k-means algorithm +on the healthy MRI in it to identify + + align:start position:0% +on the healthy MRI in it to identify + + + align:start position:0% +on the healthy MRI in it to identify +tumors in another MRI image of a sick + + align:start position:0% +tumors in another MRI image of a sick + + + align:start position:0% +tumors in another MRI image of a sick +patient we will see if this is possible + + align:start position:0% +patient we will see if this is possible + + + align:start position:0% +patient we will see if this is possible +in the next video \ No newline at end of file diff --git a/WVOIk8en6YE.txt b/WVOIk8en6YE.txt new file mode 100644 index 0000000000000000000000000000000000000000..87a8c2a82b33b6df6bd27232227ecce4137a2f7c --- /dev/null +++ b/WVOIk8en6YE.txt @@ -0,0 +1,10411 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay let us start so let me + + align:start position:0% +ocw.mit.edu okay let us start so let me + + + align:start position:0% +ocw.mit.edu okay let us start so let me +first remind you what we did uh uh in N + + align:start position:0% +first remind you what we did uh uh in N + + + align:start position:0% +first remind you what we did uh uh in N +neure we proved + + align:start position:0% + + + + align:start position:0% + +we showed that the wber we + + align:start position:0% + + + + align:start position:0% + +theem + + align:start position:0% + + + + align:start position:0% + +forbids + + align:start position:0% + + + + align:start position:0% + +existence of mes + + align:start position:0% + + + + align:start position:0% + +spin two + + align:start position:0% + + + + align:start position:0% + +particles matx spin two particles are + + align:start position:0% +particles matx spin two particles are + + + align:start position:0% +particles matx spin two particles are +whole Mark of of gravity so that's why + + align:start position:0% +whole Mark of of gravity so that's why + + + align:start position:0% +whole Mark of of gravity so that's why +we look for + + align:start position:0% + + + + align:start position:0% + +them in the + + align:start position:0% +them in the + + + align:start position:0% +them in the +same so emphasiz in the same space + + align:start position:0% + + + + align:start position:0% + +time say a + + align:start position:0% +time say a + + + align:start position:0% +time say a +qft leaves + + align:start position:0% + + + + align:start position:0% + +okay so this theem essentially say + + align:start position:0% +okay so this theem essentially say + + + align:start position:0% +okay so this theem essentially say +this you will never have emerging + + align:start position:0% +this you will never have emerging + + + align:start position:0% +this you will never have emerging +gravity start from low ranging variant + + align:start position:0% +gravity start from low ranging variant + + + align:start position:0% +gravity start from low ranging variant +Quantum field Theory with a well defined + + align:start position:0% +Quantum field Theory with a well defined + + + align:start position:0% +Quantum field Theory with a well defined +stress + + align:start position:0% + + + + align:start position:0% + +tensor so as we already + + align:start position:0% +tensor so as we already + + + align:start position:0% +tensor so as we already +mentioned is a nohole of this + + align:start position:0% + + + + align:start position:0% + +Serum is + + align:start position:0% +Serum is + + + align:start position:0% +Serum is +that actually a emerging space emerging + + align:start position:0% + + + + align:start position:0% + +gravity can actually + + align:start position:0% + + + + align:start position:0% + +leave in the different space + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +as in holographic + + align:start position:0% + + + + align:start position:0% + +duality in fact in holographic + + align:start position:0% +duality in fact in holographic + + + align:start position:0% +duality in fact in holographic +Duality the gravity leaves in one + + align:start position:0% +Duality the gravity leaves in one + + + align:start position:0% +Duality the gravity leaves in one +dimension + + align:start position:0% + + + + align:start position:0% + +higher but we are not ready to go there + + align:start position:0% +higher but we are not ready to go there + + + align:start position:0% +higher but we are not ready to go there +yet so in order to describe this thing + + align:start position:0% +yet so in order to describe this thing + + + align:start position:0% +yet so in order to describe this thing +we still lead to um do some + + align:start position:0% +we still lead to um do some + + + align:start position:0% +we still lead to um do some +preparations so the + + align:start position:0% + + + + align:start position:0% + +preparations let me just outline the + + align:start position:0% +preparations let me just outline the + + + align:start position:0% +preparations let me just outline the +preparations we need to + + align:start position:0% + + + + align:start position:0% + +do so the first thing we will do is + + align:start position:0% +do so the first thing we will do is + + + align:start position:0% +do so the first thing we will do is +black hole thermodynamics + + align:start position:0% + + + + align:start position:0% + +okay so this will give + + align:start position:0% +okay so this will give + + + align:start position:0% +okay so this will give +hint for something called holographic + + align:start position:0% + + + + align:start position:0% + +principle which is actually more + + align:start position:0% +principle which is actually more + + + align:start position:0% +principle which is actually more +General than the holographic Duality + + align:start position:0% +General than the holographic Duality + + + align:start position:0% +General than the holographic Duality +discovered so + + align:start position:0% + + + + align:start position:0% + +far and the second thing is we will also + + align:start position:0% + + + + align:start position:0% + +quickly go over the larg engage series + + align:start position:0% +quickly go over the larg engage series + + + align:start position:0% +quickly go over the larg engage series +the properties of the Marg say a G + + align:start position:0% + + + + align:start position:0% + +Series so this give + + align:start position:0% +Series so this give + + + align:start position:0% +Series so this give +hint something called the gauge + + align:start position:0% + + + + align:start position:0% + +strings parity + + align:start position:0% + + + + align:start position:0% + +so the behavior of the Lage + + align:start position:0% +so the behavior of the Lage + + + align:start position:0% +so the behavior of the Lage +the give you a strong + + align:start position:0% +the give you a strong + + + align:start position:0% +the give you a strong +hint that actually this a string series + + align:start position:0% +hint that actually this a string series + + + align:start position:0% +hint that actually this a string series +description for ordinary gauge series + + align:start position:0% +description for ordinary gauge series + + + align:start position:0% +description for ordinary gauge series +okay and when you combine this these two + + align:start position:0% +okay and when you combine this these two + + + align:start position:0% +okay and when you combine this these two +things together then you get what we + + align:start position:0% +things together then you get what we + + + align:start position:0% +things together then you get what we +have currently the holographic + + align:start position:0% +have currently the holographic + + + align:start position:0% +have currently the holographic +Duality and + + align:start position:0% +Duality and + + + align:start position:0% +Duality and +uh then a then we will also talk a + + align:start position:0% +uh then a then we will also talk a + + + align:start position:0% +uh then a then we will also talk a +little bit + + align:start position:0% +little bit + + + align:start position:0% +little bit +of scen theory a tiny bit not a lot so + + align:start position:0% +of scen theory a tiny bit not a lot so + + + align:start position:0% +of scen theory a tiny bit not a lot so +don't be + + align:start position:0% +don't be + + + align:start position:0% +don't be +scared so we also will talk a little bit + + align:start position:0% +scared so we also will talk a little bit + + + align:start position:0% +scared so we also will talk a little bit +about screen + + align:start position:0% +about screen + + + align:start position:0% +about screen +Theory so in principle actually I can + + align:start position:0% +Theory so in principle actually I can + + + align:start position:0% +Theory so in principle actually I can +talk about holographic Duality right now + + align:start position:0% +talk about holographic Duality right now + + + align:start position:0% +talk about holographic Duality right now +but going over those aspects can help + + align:start position:0% +but going over those aspects can help + + + align:start position:0% +but going over those aspects can help +you to build some intuitions and also to + + align:start position:0% +you to build some intuitions and also to + + + align:start position:0% +you to build some intuitions and also to +have a broader uh uh perspective than um + + align:start position:0% +have a broader uh uh perspective than um + + + align:start position:0% +have a broader uh uh perspective than um +than just presenting the uh uh uh + + align:start position:0% +than just presenting the uh uh uh + + + align:start position:0% +than just presenting the uh uh uh +Duality + + align:start position:0% +Duality + + + align:start position:0% +Duality +directory so before I start uh today's + + align:start position:0% +directory so before I start uh today's + + + align:start position:0% +directory so before I start uh today's +uh uh lecture do you have any questions + + align:start position:0% +uh uh lecture do you have any questions + + + align:start position:0% +uh uh lecture do you have any questions +regarding our last lecture and regarding + + align:start position:0% +regarding our last lecture and regarding + + + align:start position:0% +regarding our last lecture and regarding +uh uh this um um yeah General remarks + + align:start position:0% +uh uh this um um yeah General remarks + + + align:start position:0% +uh uh this um um yeah General remarks +here yes so moving forward are we going + + align:start position:0% +here yes so moving forward are we going + + + align:start position:0% +here yes so moving forward are we going +to Define uh emerging gravity as the + + align:start position:0% +to Define uh emerging gravity as the + + + align:start position:0% +to Define uh emerging gravity as the +existence of a massless v 2 particle uh + + align:start position:0% +existence of a massless v 2 particle uh + + + align:start position:0% +existence of a massless v 2 particle uh +no that we will not do so how are we + + align:start position:0% +no that we will not do so how are we + + + align:start position:0% +no that we will not do so how are we +defining emerging gravity + + align:start position:0% +defining emerging gravity + + + align:start position:0% +defining emerging gravity +um um you construct newon La + + align:start position:0% +um um you construct newon La + + + align:start position:0% +um um you construct newon La +yeah you will see it you will see it + + align:start position:0% +yeah you will see it you will see it + + + align:start position:0% +yeah you will see it you will see it +when we have it yeah essentially you see + + align:start position:0% +when we have it yeah essentially you see + + + align:start position:0% +when we have it yeah essentially you see +the uh you see um essentially it's + + align:start position:0% +the uh you see um essentially it's + + + align:start position:0% +the uh you see um essentially it's +handed over to you you don't have to go + + align:start position:0% +handed over to you you don't have to go + + + align:start position:0% +handed over to you you don't have to go +through that step yeah you don't have to + + align:start position:0% +through that step yeah you don't have to + + + align:start position:0% +through that step yeah you don't have to +go through that step uh um yeah + + align:start position:0% + + + + align:start position:0% + +um any other + + align:start position:0% + + + + align:start position:0% + +questions okay okay good good let's + + align:start position:0% +questions okay okay good good let's + + + align:start position:0% +questions okay okay good good let's +start with black hole some + + align:start position:0% + + + + align:start position:0% + +Dynamics so let me we start by doing a + + align:start position:0% +Dynamics so let me we start by doing a + + + align:start position:0% +Dynamics so let me we start by doing a +little bit um dimensional + + align:start position:0% +little bit um dimensional + + + align:start position:0% +little bit um dimensional +analysis just to remind + + align:start position:0% +analysis just to remind + + + align:start position:0% +analysis just to remind +you important scales for the + + align:start position:0% + + + + align:start position:0% + +gravity okay so the first thing is what + + align:start position:0% +gravity okay so the first thing is what + + + align:start position:0% +gravity okay so the first thing is what +we call the plank scale + + align:start position:0% + + + + align:start position:0% + +so in nature we have fundamental + + align:start position:0% + + + + align:start position:0% + +constants H Bar Newton constant and the + + align:start position:0% +constants H Bar Newton constant and the + + + align:start position:0% +constants H Bar Newton constant and the +C speed of + + align:start position:0% +C speed of + + + align:start position:0% +C speed of +light and + + align:start position:0% +light and + + + align:start position:0% +light and +immediately after + + align:start position:0% +immediately after + + + align:start position:0% +immediately after +plunk himself introduced this H + + align:start position:0% +plunk himself introduced this H + + + align:start position:0% +plunk himself introduced this H +bar he realized you can actually combine + + align:start position:0% +bar he realized you can actually combine + + + align:start position:0% +bar he realized you can actually combine +the three of them to come up with a map + + align:start position:0% +the three of them to come up with a map + + + align:start position:0% +the three of them to come up with a map +scale which is just + + align:start position:0% +scale which is just + + + align:start position:0% +scale which is just +hc/ by + + align:start position:0% +hc/ by + + + align:start position:0% +hc/ by +GN and this if you plug in the exessive + + align:start position:0% +GN and this if you plug in the exessive + + + align:start position:0% +GN and this if you plug in the exessive +numerical value is about 1.2 to the 10 + + align:start position:0% +numerical value is about 1.2 to the 10 + + + align:start position:0% +numerical value is about 1.2 to the 10 +to the 19 G + + align:start position:0% +to the 19 G + + + align:start position:0% +to the 19 G +v/ by + + align:start position:0% +v/ by + + + align:start position:0% +v/ by +c² you can also write it in terms of the + + align:start position:0% +c² you can also write it in terms of the + + + align:start position:0% +c² you can also write it in terms of the +gram which is about + + align:start position:0% +gram which is about + + + align:start position:0% +gram which is about +2.2 10 Theus 5 GR + + align:start position:0% + + + + align:start position:0% + +and then you can also have you can also + + align:start position:0% +and then you can also have you can also + + + align:start position:0% +and then you can also have you can also +construct the lens + + align:start position:0% +construct the lens + + + align:start position:0% +construct the lens +scale which is H GN divide C + + align:start position:0% +scale which is H GN divide C + + + align:start position:0% +scale which is H GN divide C +Cube which is about 1.6 to 10 Theus 33 + + align:start position:0% + + + + align:start position:0% + +cm and uh + + align:start position:0% +cm and uh + + + align:start position:0% +cm and uh +PP which is l/ C okay + + align:start position:0% + + + + align:start position:0% + +so so this was discovered so this + + align:start position:0% +so so this was discovered so this + + + align:start position:0% +so so this was discovered so this +was plank introduced them in 19 in 1899 + + align:start position:0% +was plank introduced them in 19 in 1899 + + + align:start position:0% +was plank introduced them in 19 in 1899 +so you may most of you may know the + + align:start position:0% +so you may most of you may know the + + + align:start position:0% +so you may most of you may know the +story and just immediately after he + + align:start position:0% +story and just immediately after he + + + align:start position:0% +story and just immediately after he +introduced HB so so he discovered so + + align:start position:0% +introduced HB so so he discovered so + + + align:start position:0% +introduced HB so so he discovered so +introduced H bar in 1899 in the same + + align:start position:0% +introduced H bar in 1899 in the same + + + align:start position:0% +introduced H bar in 1899 in the same +year he realized you can write down + + align:start position:0% +year he realized you can write down + + + align:start position:0% +year he realized you can write down +those + + align:start position:0% +those + + + align:start position:0% +those +numbers and of course those numbers + + align:start position:0% +numbers and of course those numbers + + + align:start position:0% +numbers and of course those numbers +meant nothing to him because that time + + align:start position:0% +meant nothing to him because that time + + + align:start position:0% +meant nothing to him because that time +we don't know special Rel at that time + + align:start position:0% +we don't know special Rel at that time + + + align:start position:0% +we don't know special Rel at that time +he didn't know special relativity he + + align:start position:0% +he didn't know special relativity he + + + align:start position:0% +he didn't know special relativity he +didn't know quantum mechanics he didn't + + align:start position:0% +didn't know quantum mechanics he didn't + + + align:start position:0% +didn't know quantum mechanics he didn't +he essenti he didn't know + + align:start position:0% +he essenti he didn't know + + + align:start position:0% +he essenti he didn't know +anything + + align:start position:0% +anything + + + align:start position:0% +anything +but but he famously + + align:start position:0% +but but he famously + + + align:start position:0% +but but he famously +said that these + + align:start position:0% +said that these + + + align:start position:0% +said that these +units so he claimed those should be + + align:start position:0% +units so he claimed those should be + + + align:start position:0% +units so he claimed those should be +basic units of + + align:start position:0% +basic units of + + + align:start position:0% +basic units of +physics and he also said these are the + + align:start position:0% +physics and he also said these are the + + + align:start position:0% +physics and he also said these are the +units that would retain the significant + + align:start position:0% +units that would retain the significant + + + align:start position:0% +units that would retain the significant +for all times and all + + align:start position:0% + + + + align:start position:0% + +cultures he even he even said the even + + align:start position:0% +cultures he even he even said the even + + + align:start position:0% +cultures he even he even said the even +will apply to um to + + align:start position:0% + + + + align:start position:0% + +aliens but only after 50 years so after + + align:start position:0% +aliens but only after 50 years so after + + + align:start position:0% +aliens but only after 50 years so after +1950s people uh get some sense so many + + align:start position:0% +1950s people uh get some sense so many + + + align:start position:0% +1950s people uh get some sense so many +years after special + + align:start position:0% +years after special + + + align:start position:0% +years after special +relativity many years after general + + align:start position:0% +relativity many years after general + + + align:start position:0% +relativity many years after general +relativity and also quantum mechanics + + align:start position:0% +relativity and also quantum mechanics + + + align:start position:0% +relativity and also quantum mechanics +Etc + + align:start position:0% +Etc + + + align:start position:0% +Etc +people started grasping the meaning of + + align:start position:0% +people started grasping the meaning of + + + align:start position:0% +people started grasping the meaning of +those + + align:start position:0% +those + + + align:start position:0% +those +scales and uh so uh so let me uh briefly + + align:start position:0% +scales and uh so uh so let me uh briefly + + + align:start position:0% +scales and uh so uh so let me uh briefly +review + + align:start position:0% + + + + align:start position:0% + +them so you + + align:start position:0% +them so you + + + align:start position:0% +them so you +can get the feeling of the meaning of + + align:start position:0% +can get the feeling of the meaning of + + + align:start position:0% +can get the feeling of the meaning of +those scales by looking at the strength + + align:start position:0% +those scales by looking at the strength + + + align:start position:0% +those scales by looking at the strength +of + + align:start position:0% +of + + + align:start position:0% +of +gravity so let me first start this + + align:start position:0% +gravity so let me first start this + + + align:start position:0% +gravity so let me first start this +example for + + align:start position:0% +example for + + + align:start position:0% +example for +electromagnetism which you have a + + align:start position:0% +electromagnetism which you have a + + + align:start position:0% +electromagnetism which you have a +potential which is e s/ r okay + + align:start position:0% +potential which is e s/ r okay + + + align:start position:0% +potential which is e s/ r okay +say if you have two charge particle of + + align:start position:0% +say if you have two charge particle of + + + align:start position:0% +say if you have two charge particle of +charge e then the potential between them + + align:start position:0% +charge e then the potential between them + + + align:start position:0% +charge e then the potential between them +is e s/ + + align:start position:0% + + + + align:start position:0% + +r and for for particle of mass m then + + align:start position:0% +r and for for particle of mass m then + + + align:start position:0% +r and for for particle of mass m then +you also have competent + + align:start position:0% + + + + align:start position:0% + +wavelength say if you have a particle + + align:start position:0% +wavelength say if you have a particle + + + align:start position:0% +wavelength say if you have a particle +with mass m you also have Conant + + align:start position:0% +with mass m you also have Conant + + + align:start position:0% +with mass m you also have Conant +wavelength each H baride by + + align:start position:0% +wavelength each H baride by + + + align:start position:0% +wavelength each H baride by +MC + + align:start position:0% +MC + + + align:start position:0% +MC +okay so you can get + + align:start position:0% + + + + align:start position:0% + +a rough measure of the + + align:start position:0% +a rough measure of the + + + align:start position:0% +a rough measure of the +strings of + + align:start position:0% +strings of + + + align:start position:0% +strings of +electromagnetism the interaction + + align:start position:0% +electromagnetism the interaction + + + align:start position:0% +electromagnetism the interaction +strength of the + + align:start position:0% + + + + align:start position:0% + +electromagnetism by considering the + + align:start position:0% +electromagnetism by considering the + + + align:start position:0% +electromagnetism by considering the +following Dimension is + + align:start position:0% +following Dimension is + + + align:start position:0% +following Dimension is +number so which I call Lambda e which is + + align:start position:0% +number so which I call Lambda e which is + + + align:start position:0% +number so which I call Lambda e which is +the + + align:start position:0% +the + + + align:start position:0% +the +potential + + align:start position:0% +potential + + + align:start position:0% +potential +evaluated at the minimal in Quantum + + align:start position:0% +evaluated at the minimal in Quantum + + + align:start position:0% +evaluated at the minimal in Quantum +mechanic X essentially this is the + + align:start position:0% +mechanic X essentially this is the + + + align:start position:0% +mechanic X essentially this is the +minimal distance you can make sense + + align:start position:0% +minimal distance you can make sense + + + align:start position:0% +minimal distance you can make sense +of because once you go distance smaller + + align:start position:0% +of because once you go distance smaller + + + align:start position:0% +of because once you go distance smaller +than this you can no longer and and then + + align:start position:0% +than this you can no longer and and then + + + align:start position:0% +than this you can no longer and and then +the quantum uncertainty will create the + + align:start position:0% +the quantum uncertainty will create the + + + align:start position:0% +the quantum uncertainty will create the +energy uncertainty bigger than M you can + + align:start position:0% +energy uncertainty bigger than M you can + + + align:start position:0% +energy uncertainty bigger than M you can +no longer talk about the particle + + align:start position:0% +no longer talk about the particle + + + align:start position:0% +no longer talk about the particle +sensity then you can no longer talk + + align:start position:0% +sensity then you can no longer talk + + + align:start position:0% +sensity then you can no longer talk +about single particle in a sensible way + + align:start position:0% +about single particle in a sensible way + + + align:start position:0% +about single particle in a sensible way +so this is essentially the minimal then + + align:start position:0% +so this is essentially the minimal then + + + align:start position:0% +so this is essentially the minimal then +scale you can talk about single + + align:start position:0% +scale you can talk about single + + + align:start position:0% +scale you can talk about single +particles + + align:start position:0% +particles + + + align:start position:0% +particles +so so this is essentially some energy + + align:start position:0% +so so this is essentially some energy + + + align:start position:0% +so so this is essentially some energy +scale so you can compare this to the say + + align:start position:0% +scale so you can compare this to the say + + + align:start position:0% +scale so you can compare this to the say +the static mass of the particle so this + + align:start position:0% +the static mass of the particle so this + + + align:start position:0% +the static mass of the particle so this +give you a a measure of the strength of + + align:start position:0% +give you a a measure of the strength of + + + align:start position:0% +give you a a measure of the strength of +the electrom + + align:start position:0% +the electrom + + + align:start position:0% +the electrom +magnetism of course if you plug this in + + align:start position:0% +magnetism of course if you plug this in + + + align:start position:0% +magnetism of course if you plug this in +you just get e s / H+ C and of course we + + align:start position:0% +you just get e s / H+ C and of course we + + + align:start position:0% +you just get e s / H+ C and of course we +know this is the fine structure constant + + align:start position:0% +know this is the fine structure constant + + + align:start position:0% +know this is the fine structure constant +which is + + align:start position:0% +which is + + + align:start position:0% +which is +indeed the the + + align:start position:0% +indeed the the + + + align:start position:0% +indeed the the +coupling say you would do um indeed is + + align:start position:0% +coupling say you would do um indeed is + + + align:start position:0% +coupling say you would do um indeed is +the coupling Q okay so you can do the + + align:start position:0% +the coupling Q okay so you can do the + + + align:start position:0% +the coupling Q okay so you can do the +same thing for + + align:start position:0% +same thing for + + + align:start position:0% +same thing for +Gravity so you can do the same thing for + + align:start position:0% + + + + align:start position:0% + +Gravity so for + + align:start position:0% + + + + align:start position:0% + +Gravity we have essentially + + align:start position:0% +Gravity we have essentially + + + align:start position:0% +Gravity we have essentially +G and say if you take two particle of + + align:start position:0% +G and say if you take two particle of + + + align:start position:0% +G and say if you take two particle of +mass m + + align:start position:0% +mass m + + + align:start position:0% +mass m +then then then the potential between + + align:start position:0% +then then then the potential between + + + align:start position:0% +then then then the potential between +them is GM m² / + + align:start position:0% +them is GM m² / + + + align:start position:0% +them is GM m² / +R and then again you can Define + + align:start position:0% +R and then again you can Define + + + align:start position:0% +R and then again you can Define +effective strength for the Gravity by + + align:start position:0% +effective strength for the Gravity by + + + align:start position:0% +effective strength for the Gravity by +evaluate this potential at compant wave + + align:start position:0% +evaluate this potential at compant wave + + + align:start position:0% +evaluate this potential at compant wave +lens divided by the static energy of the + + align:start position:0% +lens divided by the static energy of the + + + align:start position:0% +lens divided by the static energy of the +particle and then you can just plug this + + align:start position:0% +particle and then you can just plug this + + + align:start position:0% +particle and then you can just plug this +in so so this is GN m² / by h bar / by + + align:start position:0% +in so so this is GN m² / by h bar / by + + + align:start position:0% +in so so this is GN m² / by h bar / by +MC then / by + + align:start position:0% + + + + align:start position:0% + +mc² and then you find this is just equal + + align:start position:0% + + + + align:start position:0% + +to this is equal to + + align:start position:0% +to this is equal to + + + align:start position:0% +to this is equal to +GN m² divided by H Bar + + align:start position:0% +GN m² divided by H Bar + + + align:start position:0% +GN m² divided by H Bar +C + + align:start position:0% +C + + + align:start position:0% +C +okay so now if you + + align:start position:0% +okay so now if you + + + align:start position:0% +okay so now if you +compare with this + + align:start position:0% +compare with this + + + align:start position:0% +compare with this +equation so so this is just given by m + + align:start position:0% +equation so so this is just given by m + + + align:start position:0% +equation so so this is just given by m +Square MP + + align:start position:0% +Square MP + + + align:start position:0% +Square MP +s okay so for + + align:start position:0% +s okay so for + + + align:start position:0% +s okay so for +Gravity this effective + + align:start position:0% +Gravity this effective + + + align:start position:0% +Gravity this effective +strength is just given by the mass of + + align:start position:0% +strength is just given by the mass of + + + align:start position:0% +strength is just given by the mass of +the particle so because for Gravity the + + align:start position:0% +the particle so because for Gravity the + + + align:start position:0% +the particle so because for Gravity the +Mass is like some kind of effective + + align:start position:0% +Mass is like some kind of effective + + + align:start position:0% +Mass is like some kind of effective +charge and divided by plank scale this + + align:start position:0% +charge and divided by plank scale this + + + align:start position:0% +charge and divided by plank scale this +plank mass square + + align:start position:0% +plank mass square + + + align:start position:0% +plank mass square +okay and you can also write + + align:start position:0% +okay and you can also write + + + align:start position:0% +okay and you can also write +it you can also write it + + align:start position:0% + + + + align:start position:0% + +as LP + + align:start position:0% +as LP + + + align:start position:0% +as LP +s divided by RC + + align:start position:0% +s divided by RC + + + align:start position:0% +s divided by RC +sare or or just as this plank + + align:start position:0% +sare or or just as this plank + + + align:start position:0% +sare or or just as this plank +lens divided by component wavelength of + + align:start position:0% +lens divided by component wavelength of + + + align:start position:0% +lens divided by component wavelength of +this + + align:start position:0% +this + + + align:start position:0% +this +particle + + align:start position:0% +particle + + + align:start position:0% +particle +okay so for most Elementary + + align:start position:0% + + + + align:start position:0% + +particles so so for typical Elementary + + align:start position:0% +particles so so for typical Elementary + + + align:start position:0% +particles so so for typical Elementary +particles we know the m is always much + + align:start position:0% +particles we know the m is always much + + + align:start position:0% +particles we know the m is always much +smaller than MP + + align:start position:0% +smaller than MP + + + align:start position:0% +smaller than MP +okay and then the Lambda G will be + + align:start position:0% +okay and then the Lambda G will be + + + align:start position:0% +okay and then the Lambda G will be +typically much smaller than + + align:start position:0% +typically much smaller than + + + align:start position:0% +typically much smaller than +one so for + + align:start position:0% +one so for + + + align:start position:0% +one so for +example say if you can see the + + align:start position:0% + + + + align:start position:0% + +electron the electron Mass would be say + + align:start position:0% +electron the electron Mass would be say + + + align:start position:0% +electron the electron Mass would be say +5 to the 10 Theus 4 G v/ + + align:start position:0% +5 to the 10 Theus 4 G v/ + + + align:start position:0% +5 to the 10 Theus 4 G v/ +c² of course this is much smaller than + + align:start position:0% +c² of course this is much smaller than + + + align:start position:0% +c² of course this is much smaller than +this plankk + + align:start position:0% +this plankk + + + align:start position:0% +this plankk +mass and then you find this ratio + + align:start position:0% +mass and then you find this ratio + + + align:start position:0% +mass and then you find this ratio +so you can work out this ratio so let's + + align:start position:0% +so you can work out this ratio so let's + + + align:start position:0% +so you can work out this ratio so let's +compare it to the to the corresponding + + align:start position:0% +compare it to the to the corresponding + + + align:start position:0% +compare it to the to the corresponding +strings for the + + align:start position:0% +strings for the + + + align:start position:0% +strings for the +electromagnetic so this is about 10 + + align:start position:0% +electromagnetic so this is about 10 + + + align:start position:0% +electromagnetic so this is about 10 +Theus + + align:start position:0% +Theus + + + align:start position:0% +Theus +43 if you work this + + align:start position:0% +43 if you work this + + + align:start position:0% +43 if you work this +out okay so this tells you the gravity + + align:start position:0% +out okay so this tells you the gravity + + + align:start position:0% +out okay so this tells you the gravity +is really + + align:start position:0% + + + + align:start position:0% + +weak so for + + align:start position:0% + + + + align:start position:0% + +Ordinary Elementary + + align:start position:0% +Ordinary Elementary + + + align:start position:0% +Ordinary Elementary +particles so the gravity is really weak + + align:start position:0% +particles so the gravity is really weak + + + align:start position:0% +particles so the gravity is really weak +and so so we can forget all about + + align:start position:0% +and so so we can forget all about + + + align:start position:0% +and so so we can forget all about +gravity + + align:start position:0% +gravity + + + align:start position:0% +gravity +until you reach the plank + + align:start position:0% +until you reach the plank + + + align:start position:0% +until you reach the plank +Mass all your compant wavelengths reach + + align:start position:0% +Mass all your compant wavelengths reach + + + align:start position:0% +Mass all your compant wavelengths reach +the plank lens and then um then the + + align:start position:0% +the plank lens and then um then the + + + align:start position:0% +the plank lens and then um then the +gravity then effect of the quantum + + align:start position:0% +gravity then effect of the quantum + + + align:start position:0% +gravity then effect of the quantum +gravity will be + + align:start position:0% +gravity will be + + + align:start position:0% +gravity will be +important so so from this exercise we + + align:start position:0% +important so so from this exercise we + + + align:start position:0% +important so so from this exercise we +know that the MP is the energy scale + + align:start position:0% + + + + align:start position:0% + +that the effective gravity strengths + + align:start position:0% +that the effective gravity strengths + + + align:start position:0% +that the effective gravity strengths +become of order + + align:start position:0% +become of order + + + align:start position:0% +become of order +one come of order + + align:start position:0% + + + + align:start position:0% + +one that + + align:start position:0% +one that + + + align:start position:0% +one that +is quantum gravity + + align:start position:0% + + + + align:start position:0% + +effect become significant + + align:start position:0% + + + + align:start position:0% + +okay and uh and similarly so so + + align:start position:0% +okay and uh and similarly so so + + + align:start position:0% +okay and uh and similarly so so +a is the corresponding lens + + align:start position:0% + + + + align:start position:0% + +scale associate with such energy + + align:start position:0% + + + + align:start position:0% + +okay so this give you a + + align:start position:0% +okay so this give you a + + + align:start position:0% +okay so this give you a +heris fit in + + align:start position:0% +heris fit in + + + align:start position:0% +heris fit in +give you her istic + + align:start position:0% +give you her istic + + + align:start position:0% +give you her istic +indication that the meaning of those + + align:start position:0% +indication that the meaning of those + + + align:start position:0% +indication that the meaning of those +plank scales + + align:start position:0% +plank scales + + + align:start position:0% +plank scales +okay so there's another important scale + + align:start position:0% +okay so there's another important scale + + + align:start position:0% +okay so there's another important scale +associate with + + align:start position:0% +associate with + + + align:start position:0% +associate with +gravity so any questions on + + align:start position:0% + + + + align:start position:0% + +this good there's another important + + align:start position:0% +this good there's another important + + + align:start position:0% +this good there's another important +scale associated with gravity it's + + align:start position:0% +scale associated with gravity it's + + + align:start position:0% +scale associated with gravity it's +called swal radius + + align:start position:0% + + + + align:start position:0% + +so I should + + align:start position:0% +so I should + + + align:start position:0% +so I should +radius so the just from dimensional + + align:start position:0% +radius so the just from dimensional + + + align:start position:0% +radius so the just from dimensional +lysis the stral radius can be argued as + + align:start position:0% +lysis the stral radius can be argued as + + + align:start position:0% +lysis the stral radius can be argued as +follows so consider again we can just uh + + align:start position:0% +follows so consider again we can just uh + + + align:start position:0% +follows so consider again we can just uh +even see it from Newtonian + + align:start position:0% +even see it from Newtonian + + + align:start position:0% +even see it from Newtonian +gravity so say let's consider + + align:start position:0% + + + + align:start position:0% + +object of mass + + align:start position:0% + + + + align:start position:0% + +m okay + + align:start position:0% +m okay + + + align:start position:0% +m okay +then we + + align:start position:0% +then we + + + align:start position:0% +then we +ask then we ask + + align:start position:0% +ask then we ask + + + align:start position:0% +ask then we ask +what is the + + align:start position:0% + + + + align:start position:0% + +distance at what distance maybe I + + align:start position:0% + + + + align:start position:0% + +should at what + + align:start position:0% + + + + align:start position:0% + +distance from + + align:start position:0% + + + + align:start position:0% + +it the classical gravity becomes strong + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so for this purpose let's consider say a + + align:start position:0% +so for this purpose let's consider say a + + + align:start position:0% +so for this purpose let's consider say a +pro Mass say m + + align:start position:0% +pro Mass say m + + + align:start position:0% +pro Mass say m +Prime so can see the pro Mass + + align:start position:0% + + + + align:start position:0% + +okay so I Define a scale which I call r + + align:start position:0% +okay so I Define a scale which I call r + + + align:start position:0% +okay so I Define a scale which I call r +s is I require the potential energy + + align:start position:0% +s is I require the potential energy + + + align:start position:0% +s is I require the potential energy +between M and M Prime at such a scale r + + align:start position:0% +between M and M Prime at such a scale r + + + align:start position:0% +between M and M Prime at such a scale r +s then this become of + + align:start position:0% +s then this become of + + + align:start position:0% +s then this become of +order say the again the energy the + + align:start position:0% +order say the again the energy the + + + align:start position:0% +order say the again the energy the +static energy of this probe + + align:start position:0% +static energy of this probe + + + align:start position:0% +static energy of this probe +particle of this probe + + align:start position:0% +particle of this probe + + + align:start position:0% +particle of this probe +Mass so if you cancel things out then + + align:start position:0% +Mass so if you cancel things out then + + + align:start position:0% +Mass so if you cancel things out then +you find is s is of order + + align:start position:0% + + + + align:start position:0% + +GM m / + + align:start position:0% +GM m / + + + align:start position:0% +GM m / +c² + + align:start position:0% +c² + + + align:start position:0% +c² +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so this give you a a + + align:start position:0% +so so this give you a a + + + align:start position:0% +so so this give you a a +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um uh give you a scale you can also ask + + align:start position:0% +um uh give you a scale you can also ask + + + align:start position:0% +um uh give you a scale you can also ask +so this is from neonian + + align:start position:0% +so this is from neonian + + + align:start position:0% +so this is from neonian +gravity of course the um when your + + align:start position:0% +gravity of course the um when your + + + align:start position:0% +gravity of course the um when your +gravity becomes strong uh you should + + align:start position:0% +gravity becomes strong uh you should + + + align:start position:0% +gravity becomes strong uh you should +replace the ding Gravity by by Einstein + + align:start position:0% +replace the ding Gravity by by Einstein + + + align:start position:0% +replace the ding Gravity by by Einstein +relativity and when you go to + + align:start position:0% + + + + align:start position:0% + +relativity when you go to relativity + + align:start position:0% +relativity when you go to relativity + + + align:start position:0% +relativity when you go to relativity +general + + align:start position:0% +general + + + align:start position:0% +general +relativity then you find then this swal + + align:start position:0% +relativity then you find then this swal + + + align:start position:0% +relativity then you find then this swal +radius so uh this saral radius which + + align:start position:0% +radius so uh this saral radius which + + + align:start position:0% +radius so uh this saral radius which +given by 2 + + align:start position:0% +given by 2 + + + align:start position:0% +given by 2 +gmid by + + align:start position:0% +gmid by + + + align:start position:0% +gmid by +c² which corresponding to the side of a + + align:start position:0% +c² which corresponding to the side of a + + + align:start position:0% +c² which corresponding to the side of a +black hole + + align:start position:0% + + + + align:start position:0% + +okay corresponding to the Sid of a black + + align:start position:0% +okay corresponding to the Sid of a black + + + align:start position:0% +okay corresponding to the Sid of a black +ho so this is a classical scale purely + + align:start position:0% +ho so this is a classical scale purely + + + align:start position:0% +ho so this is a classical scale purely +classical Gale just the scale which the + + align:start position:0% +classical Gale just the scale which the + + + align:start position:0% +classical Gale just the scale which the +classical gravity becomes + + align:start position:0% +classical gravity becomes + + + align:start position:0% +classical gravity becomes +strong and in + + align:start position:0% +strong and in + + + align:start position:0% +strong and in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +RS can be + + align:start position:0% + + + + align:start position:0% + +considered as the minimal + + align:start position:0% + + + + align:start position:0% + +M + + align:start position:0% + + + + align:start position:0% + +scale one can + + align:start position:0% + + + + align:start position:0% + +Pro a par an + + align:start position:0% + + + + align:start position:0% + +object of mass + + align:start position:0% +object of mass + + + align:start position:0% +object of mass +n + + align:start position:0% +n + + + align:start position:0% +n +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so classically black absorb everything + + align:start position:0% +so classically black absorb everything + + + align:start position:0% +so classically black absorb everything +so once you four into black ho you can + + align:start position:0% +so once you four into black ho you can + + + align:start position:0% +so once you four into black ho you can +never come + + align:start position:0% +never come + + + align:start position:0% +never come +back and uh so so the minimal distance + + align:start position:0% +back and uh so so the minimal distance + + + align:start position:0% +back and uh so so the minimal distance +you can uh approach a and object of mass + + align:start position:0% +you can uh approach a and object of mass + + + align:start position:0% +you can uh approach a and object of mass +m it just given by the SWAT your radius + + align:start position:0% +m it just given by the SWAT your radius + + + align:start position:0% +m it just given by the SWAT your radius +so when you go inside SWAT your radius + + align:start position:0% +so when you go inside SWAT your radius + + + align:start position:0% +so when you go inside SWAT your radius +you just fall into the black ho and you + + align:start position:0% +you just fall into the black ho and you + + + align:start position:0% +you just fall into the black ho and you +can never send information out + + align:start position:0% +can never send information out + + + align:start position:0% +can never send information out +okay and the why interesting + + align:start position:0% + + + + align:start position:0% + +compare yeah one thing regarding this + + align:start position:0% +compare yeah one thing regarding this + + + align:start position:0% +compare yeah one thing regarding this +wasal radius you said raal radius + + align:start position:0% +wasal radius you said raal radius + + + align:start position:0% +wasal radius you said raal radius +increase + + align:start position:0% +increase + + + align:start position:0% +increase +with mass okay if you increase Mass the + + align:start position:0% +with mass okay if you increase Mass the + + + align:start position:0% +with mass okay if you increase Mass the +spal radius + + align:start position:0% +spal radius + + + align:start position:0% +spal radius +increases okay so in principle can be + + align:start position:0% +increases okay so in principle can be + + + align:start position:0% +increases okay so in principle can be +very large uh when you can see the very + + align:start position:0% +very large uh when you can see the very + + + align:start position:0% +very large uh when you can see the very +large object when you can see the very + + align:start position:0% +large object when you can see the very + + + align:start position:0% +large object when you can see the very +massive + + align:start position:0% + + + + align:start position:0% + +object so now so let us + + align:start position:0% + + + + align:start position:0% + +summarize let us + + align:start position:0% +summarize let us + + + align:start position:0% +summarize let us +summarize so for for object + + align:start position:0% + + + + align:start position:0% + +of mass + + align:start position:0% + + + + align:start position:0% + +m there are two important + + align:start position:0% + + + + align:start position:0% + +scales two important + + align:start position:0% + + + + align:start position:0% + +scales so why is just the standard + + align:start position:0% +scales so why is just the standard + + + align:start position:0% +scales so why is just the standard +compon wavelength + + align:start position:0% + + + + align:start position:0% + +okay and the other is the swal + + align:start position:0% + + + + align:start position:0% + +radius okay so one is quantum and the + + align:start position:0% +radius okay so one is quantum and the + + + align:start position:0% +radius okay so one is quantum and the +other is + + align:start position:0% +other is + + + align:start position:0% +other is +classical yeah the classical so let's + + align:start position:0% +classical yeah the classical so let's + + + align:start position:0% +classical yeah the classical so let's +take the ratio between them okay let's + + align:start position:0% +take the ratio between them okay let's + + + align:start position:0% +take the ratio between them okay let's +take the ratio between + + align:start position:0% + + + + align:start position:0% + +them so if you take the ratio between + + align:start position:0% +them so if you take the ratio between + + + align:start position:0% +them so if you take the ratio between +them + + align:start position:0% +them + + + align:start position:0% +them +so um yeah so so let's forget about this + + align:start position:0% +so um yeah so so let's forget about this + + + align:start position:0% +so um yeah so so let's forget about this +two just to consider of + + align:start position:0% +two just to consider of + + + align:start position:0% +two just to consider of +order up to order one so c² / H baride + + align:start position:0% +order up to order one so c² / H baride + + + align:start position:0% +order up to order one so c² / H baride +by + + align:start position:0% +by + + + align:start position:0% +by +MC and then this again give + + align:start position:0% +MC and then this again give + + + align:start position:0% +MC and then this again give +you GM + + align:start position:0% +you GM + + + align:start position:0% +you GM +m² divided by H Bar + + align:start position:0% + + + + align:start position:0% + +C and this is + + align:start position:0% +C and this is + + + align:start position:0% +C and this is +again just m² / m p + + align:start position:0% +again just m² / m p + + + align:start position:0% +again just m² / m p +sare + + align:start position:0% +sare + + + align:start position:0% +sare +okay this again just m Square MP Square + + align:start position:0% +okay this again just m Square MP Square + + + align:start position:0% +okay this again just m Square MP Square +MP is the plankk + + align:start position:0% +MP is the plankk + + + align:start position:0% +MP is the plankk +mass so so let's consider the different + + align:start position:0% +mass so so let's consider the different + + + align:start position:0% +mass so so let's consider the different +scenarios so the first let's consider + + align:start position:0% +scenarios so the first let's consider + + + align:start position:0% +scenarios so the first let's consider +just suppose the mass of the object is + + align:start position:0% +just suppose the mass of the object is + + + align:start position:0% +just suppose the mass of the object is +much much greater than + + align:start position:0% +much much greater than + + + align:start position:0% +much much greater than +P + + align:start position:0% +P + + + align:start position:0% +P +okay so in this + + align:start position:0% +okay so in this + + + align:start position:0% +okay so in this +case then the swal radius much ner than + + align:start position:0% +case then the swal radius much ner than + + + align:start position:0% +case then the swal radius much ner than +the compant wavelength + + align:start position:0% + + + + align:start position:0% + +much larger than the comant + + align:start position:0% +much larger than the comant + + + align:start position:0% +much larger than the comant +wavelength and essentially all the + + align:start position:0% +wavelength and essentially all the + + + align:start position:0% +wavelength and essentially all the +physics is controlled by the classical + + align:start position:0% +physics is controlled by the classical + + + align:start position:0% +physics is controlled by the classical +gravity because you can because you can + + align:start position:0% +gravity because you can because you can + + + align:start position:0% +gravity because you can because you can +no longer because you can no longer Pro + + align:start position:0% +no longer because you can no longer Pro + + + align:start position:0% +no longer because you can no longer Pro +yeah because this compant wavelength is + + align:start position:0% +yeah because this compant wavelength is + + + align:start position:0% +yeah because this compant wavelength is +much much inside the swash radius which + + align:start position:0% +much much inside the swash radius which + + + align:start position:0% +much much inside the swash radius which +you cannot prob okay so the physic is + + align:start position:0% +you cannot prob okay so the physic is + + + align:start position:0% +you cannot prob okay so the physic is +essentially classical gravity + + align:start position:0% + + + + align:start position:0% + +and uh and the um Quantum effect fact + + align:start position:0% +and uh and the um Quantum effect fact + + + align:start position:0% +and uh and the um Quantum effect fact +not + + align:start position:0% +not + + + align:start position:0% +not +important so you don't have to worry + + align:start position:0% +important so you don't have to worry + + + align:start position:0% +important so you don't have to worry +about the quantum + + align:start position:0% + + + + align:start position:0% + +effect so I will put code + + align:start position:0% +effect so I will put code + + + align:start position:0% +effect so I will put code +here uh uh not code I will put some uh + + align:start position:0% +here uh uh not code I will put some uh + + + align:start position:0% +here uh uh not code I will put some uh +yeah put some code here uh just to yeah + + align:start position:0% +yeah put some code here uh just to yeah + + + align:start position:0% +yeah put some code here uh just to yeah +you will see what this means + + align:start position:0% + + + + align:start position:0% + +and the second possibility is for Mass + + align:start position:0% +and the second possibility is for Mass + + + align:start position:0% +and the second possibility is for Mass +much much smaller than + + align:start position:0% + + + + align:start position:0% + +P so in this case then the compant + + align:start position:0% +P so in this case then the compant + + + align:start position:0% +P so in this case then the compant +wavelength will be much much greater + + align:start position:0% +wavelength will be much much greater + + + align:start position:0% +wavelength will be much much greater +than the the swater + + align:start position:0% +than the the swater + + + align:start position:0% +than the the swater +radius okay so this is a Quantum object + + align:start position:0% +radius okay so this is a Quantum object + + + align:start position:0% +radius okay so this is a Quantum object +so the quantum size is much larger than + + align:start position:0% +so the quantum size is much larger than + + + align:start position:0% +so the quantum size is much larger than +S + + align:start position:0% +S + + + align:start position:0% +S +radius but we also know precisely in + + align:start position:0% +radius but we also know precisely in + + + align:start position:0% +radius but we also know precisely in +this + + align:start position:0% + + + + align:start position:0% + +this Lambda G is also very small the + + align:start position:0% +this Lambda G is also very small the + + + align:start position:0% +this Lambda G is also very small the +effective strength of the gravity is + + align:start position:0% +effective strength of the gravity is + + + align:start position:0% +effective strength of the gravity is +also very very + + align:start position:0% +also very very + + + align:start position:0% +also very very +small so we also have found before that + + align:start position:0% +small so we also have found before that + + + align:start position:0% +small so we also have found before that +the Lambda G is also very very + + align:start position:0% +the Lambda G is also very very + + + align:start position:0% +the Lambda G is also very very +small so in this + + align:start position:0% + + + + align:start position:0% + +case as what we said here the gravity is + + align:start position:0% +case as what we said here the gravity is + + + align:start position:0% +case as what we said here the gravity is +very + + align:start position:0% + + + + align:start position:0% + +weak and notot important + + align:start position:0% + + + + align:start position:0% + +it's much much weaker than other + + align:start position:0% +it's much much weaker than other + + + align:start position:0% +it's much much weaker than other +interactions so you can essentially + + align:start position:0% +interactions so you can essentially + + + align:start position:0% +interactions so you can essentially +ignore + + align:start position:0% + + + + align:start position:0% + +them then then that only left with this + + align:start position:0% +them then then that only left with this + + + align:start position:0% +them then then that only left with this +single Square which mass is off all the + + align:start position:0% +single Square which mass is off all the + + + align:start position:0% +single Square which mass is off all the +MP and then as we said before the + + align:start position:0% +MP and then as we said before the + + + align:start position:0% +MP and then as we said before the +quantum gravity is important so let me + + align:start position:0% +quantum gravity is important so let me + + + align:start position:0% +quantum gravity is important so let me +just say quantum gravity + + align:start position:0% + + + + align:start position:0% + +important okay + + align:start position:0% + + + + align:start position:0% + +If This Were the full + + align:start position:0% +If This Were the full + + + align:start position:0% +If This Were the full +story then the life will be very boring + + align:start position:0% +story then the life will be very boring + + + align:start position:0% +story then the life will be very boring +even though it would be very + + align:start position:0% + + + + align:start position:0% + +simple because then the only scale you + + align:start position:0% +simple because then the only scale you + + + align:start position:0% +simple because then the only scale you +need to worry about quantum + + align:start position:0% +need to worry about quantum + + + align:start position:0% +need to worry about quantum +gravity is essentially matal zero it's + + align:start position:0% +gravity is essentially matal zero it's + + + align:start position:0% +gravity is essentially matal zero it's +only one + + align:start position:0% +only one + + + align:start position:0% +only one +scale and it will took us maybe 100 if + + align:start position:0% +scale and it will took us maybe 100 if + + + align:start position:0% +scale and it will took us maybe 100 if +not thousand years to reach that scale + + align:start position:0% +not thousand years to reach that scale + + + align:start position:0% +not thousand years to reach that scale +but whatever acceleration or other + + align:start position:0% +but whatever acceleration or other + + + align:start position:0% +but whatever acceleration or other +propes and so there's really low urgency + + align:start position:0% +propes and so there's really low urgency + + + align:start position:0% +propes and so there's really low urgency +to think about the quantum + + align:start position:0% +to think about the quantum + + + align:start position:0% +to think about the quantum +gravity because the um yeah right now we + + align:start position:0% +gravity because the um yeah right now we + + + align:start position:0% +gravity because the um yeah right now we +are at this kind of scale right now we + + align:start position:0% +are at this kind of scale right now we + + + align:start position:0% +are at this kind of scale right now we +are at this kind of scale it's very very + + align:start position:0% +are at this kind of scale it's very very + + + align:start position:0% +are at this kind of scale it's very very +far from this kind of + + align:start position:0% + + + + align:start position:0% + +scale but the remarkable + + align:start position:0% +scale but the remarkable + + + align:start position:0% +scale but the remarkable +thing about black + + align:start position:0% +thing about black + + + align:start position:0% +thing about black +hole so this part of the physics is + + align:start position:0% +hole so this part of the physics is + + + align:start position:0% +hole so this part of the physics is +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +controlled Say by swal read because the + + align:start position:0% +controlled Say by swal read because the + + + align:start position:0% +controlled Say by swal read because the +S radius is the + + align:start position:0% +S radius is the + + + align:start position:0% +S radius is the +minimal classical radius you + + align:start position:0% +minimal classical radius you + + + align:start position:0% +minimal classical radius you +can you can achieve uh yeah you can you + + align:start position:0% +can you can achieve uh yeah you can you + + + align:start position:0% +can you can achieve uh yeah you can you +can probe the system and the quantum + + align:start position:0% +can probe the system and the quantum + + + align:start position:0% +can probe the system and the quantum +physics is + + align:start position:0% +physics is + + + align:start position:0% +physics is +relevant but the remarkable + + align:start position:0% + + + + align:start position:0% + +thing is that it turns out this + + align:start position:0% +thing is that it turns out this + + + align:start position:0% +thing is that it turns out this +statement is not + + align:start position:0% + + + + align:start position:0% + +correct this statement is not correct + + align:start position:0% +correct this statement is not correct + + + align:start position:0% +correct this statement is not correct +actually Quantum effect is + + align:start position:0% +actually Quantum effect is + + + align:start position:0% +actually Quantum effect is +important so the remarkable + + align:start position:0% + + + + align:start position:0% + +thing you said the black + + align:start position:0% +thing you said the black + + + align:start position:0% +thing you said the black +ho can have Quantum effect + + align:start position:0% + + + + align:start position:0% + +manifest at the microscopic + + align:start position:0% + + + + align:start position:0% + +level so at then + + align:start position:0% + + + + align:start position:0% + +scale of + + align:start position:0% +scale of + + + align:start position:0% +scale of +order SW your radius okay so that's why + + align:start position:0% +order SW your radius okay so that's why + + + align:start position:0% +order SW your radius okay so that's why +it makes the black hole so + + align:start position:0% +it makes the black hole so + + + align:start position:0% +it makes the black hole so +interesting and also makes the why black + + align:start position:0% +interesting and also makes the why black + + + align:start position:0% +interesting and also makes the why black +ho is such a rich + + align:start position:0% +ho is such a rich + + + align:start position:0% +ho is such a rich +source of insight and information if you + + align:start position:0% +source of insight and information if you + + + align:start position:0% +source of insight and information if you +want to know about quantum + + align:start position:0% +want to know about quantum + + + align:start position:0% +want to know about quantum +gravity and as we will see actually we + + align:start position:0% +gravity and as we will see actually we + + + align:start position:0% +gravity and as we will see actually we +also contain a rich source information + + align:start position:0% +also contain a rich source information + + + align:start position:0% +also contain a rich source information +about ordinary manying body systems due + + align:start position:0% +about ordinary manying body systems due + + + align:start position:0% +about ordinary manying body systems due +to this + + align:start position:0% + + + + align:start position:0% + +Duality any questions regarding + + align:start position:0% +Duality any questions regarding + + + align:start position:0% +Duality any questions regarding +this yes so when we talk about M much + + align:start position:0% +this yes so when we talk about M much + + + align:start position:0% +this yes so when we talk about M much +larger than MP so the m is not only a + + align:start position:0% +larger than MP so the m is not only a + + + align:start position:0% +larger than MP so the m is not only a +elementary particle it can be just an + + align:start position:0% +elementary particle it can be just an + + + align:start position:0% +elementary particle it can be just an +object yeah yeah but if it can be a + + align:start position:0% +object yeah yeah but if it can be a + + + align:start position:0% +object yeah yeah but if it can be a +bound state so it can be a here we + + align:start position:0% +bound state so it can be a here we + + + align:start position:0% +bound state so it can be a here we +always talking about Quantum object Say + + align:start position:0% +always talking about Quantum object Say + + + align:start position:0% +always talking about Quantum object Say +Say Yeah Quantum object but can have + + align:start position:0% +Say Yeah Quantum object but can have + + + align:start position:0% +Say Yeah Quantum object but can have +mass very large that's still and Quantum + + align:start position:0% +mass very large that's still and Quantum + + + align:start position:0% +mass very large that's still and Quantum +object yeah but but you will not see + + align:start position:0% +object yeah but but you will not see + + + align:start position:0% +object yeah but but you will not see +from the from a traditional way for such + + align:start position:0% +from the from a traditional way for such + + + align:start position:0% +from the from a traditional way for such +a large mass object you will not see its + + align:start position:0% +a large mass object you will not see its + + + align:start position:0% +a large mass object you will not see its +of quantum uncertainty because Quantum + + align:start position:0% +of quantum uncertainty because Quantum + + + align:start position:0% +of quantum uncertainty because Quantum +uncertainty is Tiny the contant + + align:start position:0% +uncertainty is Tiny the contant + + + align:start position:0% +uncertainty is Tiny the contant +wavelength is very tiny so the + + align:start position:0% +wavelength is very tiny so the + + + align:start position:0% +wavelength is very tiny so the +fluctuation is very small and so you + + align:start position:0% +fluctuation is very small and so you + + + align:start position:0% +fluctuation is very small and so you +have to Pro very very small lens scale + + align:start position:0% +have to Pro very very small lens scale + + + align:start position:0% +have to Pro very very small lens scale +to see it's content from traditional + + align:start position:0% +to see it's content from traditional + + + align:start position:0% +to see it's content from traditional +point of view you have to Pro very very + + align:start position:0% +point of view you have to Pro very very + + + align:start position:0% +point of view you have to Pro very very +small lens scale to to see it quantum + + align:start position:0% +small lens scale to to see it quantum + + + align:start position:0% +small lens scale to to see it quantum +fluctuations and that lens scale is much + + align:start position:0% +fluctuations and that lens scale is much + + + align:start position:0% +fluctuations and that lens scale is much +much smaller than SWAT your radius okay + + align:start position:0% + + + + align:start position:0% + +yeah any another + + align:start position:0% + + + + align:start position:0% + +question good so let me before we talk + + align:start position:0% +question good so let me before we talk + + + align:start position:0% +question good so let me before we talk +more about talk more specific about + + align:start position:0% +more about talk more specific about + + + align:start position:0% +more about talk more specific about +black + + align:start position:0% +black + + + align:start position:0% +black +holes then let me just make one + + align:start position:0% +holes then let me just make one + + + align:start position:0% +holes then let me just make one +final + + align:start position:0% +final + + + align:start position:0% +final +remark is said in the + + align:start position:0% +remark is said in the + + + align:start position:0% +remark is said in the +sense this plank + + align:start position:0% + + + + align:start position:0% + +lens has defined this L scale as defined + + align:start position:0% +lens has defined this L scale as defined + + + align:start position:0% +lens has defined this L scale as defined +by plank can be considered as a minimal + + align:start position:0% + + + + align:start position:0% + +localization + + align:start position:0% + + + + align:start position:0% + +lens okay for the following reason so + + align:start position:0% +lens okay for the following reason so + + + align:start position:0% +lens okay for the following reason so +let's first imagine in in + + align:start position:0% +let's first imagine in in + + + align:start position:0% +let's first imagine in in +non-gravitational + + align:start position:0% +non-gravitational + + + align:start position:0% +non-gravitational +physics say in non-gravitational + + align:start position:0% + + + + align:start position:0% + +physics if you want to Pro some short + + align:start position:0% +physics if you want to Pro some short + + + align:start position:0% +physics if you want to Pro some short +distance scales okay then it's easy if + + align:start position:0% +distance scales okay then it's easy if + + + align:start position:0% +distance scales okay then it's easy if +you are rich + + align:start position:0% +you are rich + + + align:start position:0% +you are rich +enough then then you just accelerate the + + align:start position:0% +enough then then you just accelerate the + + + align:start position:0% +enough then then you just accelerate the +particles to very high + + align:start position:0% +particles to very high + + + align:start position:0% +particles to very high +energies say say say e plus e + + align:start position:0% + + + + align:start position:0% + +minus with p and minus + + align:start position:0% +minus with p and minus + + + align:start position:0% +minus with p and minus +P so you can then that can Pro the + + align:start position:0% +P so you can then that can Pro the + + + align:start position:0% +P so you can then that can Pro the +distance + + align:start position:0% + + + + align:start position:0% + +scale then then prob then this can prob + + align:start position:0% +scale then then prob then this can prob + + + align:start position:0% +scale then then prob then this can prob +length scale + + align:start position:0% + + + + align:start position:0% + +say of + + align:start position:0% +say of + + + align:start position:0% +say of +order h / + + align:start position:0% + + + + align:start position:0% + +P + + align:start position:0% +P + + + align:start position:0% +P +okay so so if you make make the + + align:start position:0% +okay so so if you make make the + + + align:start position:0% +okay so so if you make make the +particle energy high enough you can in + + align:start position:0% +particle energy high enough you can in + + + align:start position:0% +particle energy high enough you can in +principle prob as short as any scale as + + align:start position:0% +principle prob as short as any scale as + + + align:start position:0% +principle prob as short as any scale as +you want okay you + + align:start position:0% +you want okay you + + + align:start position:0% +you want okay you +can anything uh as far as you can make + + align:start position:0% +can anything uh as far as you can make + + + align:start position:0% +can anything uh as far as you can make +this p as large as you want + + align:start position:0% + + + + align:start position:0% + +so in + + align:start position:0% + + + + align:start position:0% + +principle you can take L all the way to + + align:start position:0% +principle you can take L all the way to + + + align:start position:0% +principle you can take L all the way to +zero so this scale you can all the way + + align:start position:0% +zero so this scale you can all the way + + + align:start position:0% +zero so this scale you can all the way +to zero if you take P go to + + align:start position:0% +to zero if you take P go to + + + align:start position:0% +to zero if you take P go to +Infinity + + align:start position:0% +Infinity + + + align:start position:0% +Infinity +okay but in gravity this is not + + align:start position:0% + + + + align:start position:0% + +so so so with gravity + + align:start position:0% + + + + align:start position:0% + +with gravity this is not + + align:start position:0% + + + + align:start position:0% + +so when your energ is much much greater + + align:start position:0% +so when your energ is much much greater + + + align:start position:0% +so when your energ is much much greater +than EP say say the plankk + + align:start position:0% +than EP say say the plankk + + + align:start position:0% +than EP say say the plankk +mass + + align:start position:0% + + + + align:start position:0% + +okay then as we discuss from + + align:start position:0% +okay then as we discuss from + + + align:start position:0% +okay then as we discuss from +there so so this is a center of mass + + align:start position:0% +there so so this is a center of mass + + + align:start position:0% +there so so this is a center of mass +energy okay so if your center of mass + + align:start position:0% +energy okay so if your center of mass + + + align:start position:0% +energy okay so if your center of mass +energy become much much larger than the + + align:start position:0% +energy become much much larger than the + + + align:start position:0% +energy become much much larger than the +plank scale plank + + align:start position:0% + + + + align:start position:0% + +mass then RS + + align:start position:0% + + + + align:start position:0% + +controlled by the energ yeah let me call + + align:start position:0% + + + + align:start position:0% + +P yeah let me just forget about C let me + + align:start position:0% +P yeah let me just forget about C let me + + + align:start position:0% +P yeah let me just forget about C let me +just + + align:start position:0% + + + + align:start position:0% + +say okay then the SWAT your radius from + + align:start position:0% +say okay then the SWAT your radius from + + + align:start position:0% +say okay then the SWAT your radius from +now + + align:start position:0% + + + + align:start position:0% + +on equal to one + + align:start position:0% +on equal to one + + + align:start position:0% +on equal to one +okay so um + + align:start position:0% + + + + align:start position:0% + +then the swal radius we'll take + + align:start position:0% + + + + align:start position:0% + +over as the + + align:start position:0% + + + + align:start position:0% + +minimal L + + align:start position:0% + + + + align:start position:0% + +scale okay so what's going to + + align:start position:0% +scale okay so what's going to + + + align:start position:0% +scale okay so what's going to +happen is that if you cide these two + + align:start position:0% +happen is that if you cide these two + + + align:start position:0% +happen is that if you cide these two +particle at very high + + align:start position:0% +particle at very high + + + align:start position:0% +particle at very high +energies then at certain point even + + align:start position:0% +energies then at certain point even + + + align:start position:0% +energies then at certain point even +before these two particle meets together + + align:start position:0% +before these two particle meets together + + + align:start position:0% +before these two particle meets together +they will already form a black hole of + + align:start position:0% +they will already form a black hole of + + + align:start position:0% +they will already form a black hole of +the swal sides okay if this energy is + + align:start position:0% +the swal sides okay if this energy is + + + align:start position:0% +the swal sides okay if this energy is +high + + align:start position:0% +high + + + align:start position:0% +high +enough then we form black ho and then + + align:start position:0% +enough then we form black ho and then + + + align:start position:0% +enough then we form black ho and then +you cannot then you can no longer prob + + align:start position:0% +you cannot then you can no longer prob + + + align:start position:0% +you cannot then you can no longer prob +inside the swal radius of that black ho + + align:start position:0% +inside the swal radius of that black ho + + + align:start position:0% +inside the swal radius of that black ho +so that Define a new + + align:start position:0% +so that Define a new + + + align:start position:0% +so that Define a new +scale which you can prob + + align:start position:0% + + + + align:start position:0% + +okay so so the funny thing about this + + align:start position:0% +okay so so the funny thing about this + + + align:start position:0% +okay so so the funny thing about this +was radius is that is proportional to + + align:start position:0% +was radius is that is proportional to + + + align:start position:0% +was radius is that is proportional to +energy + + align:start position:0% +energy + + + align:start position:0% +energy +rather than inverse propor to energy as + + align:start position:0% +rather than inverse propor to energy as + + + align:start position:0% +rather than inverse propor to energy as +a standard compant wavelength okay so + + align:start position:0% +a standard compant wavelength okay so + + + align:start position:0% +a standard compant wavelength okay so +after a certain point when you go beyond + + align:start position:0% +after a certain point when you go beyond + + + align:start position:0% +after a certain point when you go beyond +the plank + + align:start position:0% +the plank + + + align:start position:0% +the plank +Mass when you further increase the + + align:start position:0% +Mass when you further increase the + + + align:start position:0% +Mass when you further increase the +energy then you actually prob in the + + align:start position:0% +energy then you actually prob in the + + + align:start position:0% +energy then you actually prob in the +larger distance scales rather than + + align:start position:0% +larger distance scales rather than + + + align:start position:0% +larger distance scales rather than +smaller distance scales okay due to the + + align:start position:0% +smaller distance scales okay due to the + + + align:start position:0% +smaller distance scales okay due to the +funny thing about the gravity and the + + align:start position:0% +funny thing about the gravity and the + + + align:start position:0% +funny thing about the gravity and the +funny thing about black + + align:start position:0% +funny thing about black + + + align:start position:0% +funny thing about black +hole okay so so + + align:start position:0% +hole okay so so + + + align:start position:0% +hole okay so so +so actually uh this scale increases with + + align:start position:0% +so actually uh this scale increases with + + + align:start position:0% +so actually uh this scale increases with +P increase with your center of mass + + align:start position:0% +P increase with your center of mass + + + align:start position:0% +P increase with your center of mass +energy + + align:start position:0% + + + + align:start position:0% + +okay and the high + + align:start position:0% + + + + align:start position:0% + +energies go to longer length + + align:start position:0% + + + + align:start position:0% + +scales okay + + align:start position:0% +scales okay + + + align:start position:0% +scales okay +so this essentially defines the plank + + align:start position:0% +so this essentially defines the plank + + + align:start position:0% +so this essentially defines the plank +lens as a minimal scale one can + + align:start position:0% + + + + align:start position:0% + +Pro okay so when your center of mass + + align:start position:0% +Pro okay so when your center of mass + + + align:start position:0% +Pro okay so when your center of mass +energy smaller than the plank scale than + + align:start position:0% +energy smaller than the plank scale than + + + align:start position:0% +energy smaller than the plank scale than +the plank mass then you count the + + align:start position:0% +the plank mass then you count the + + + align:start position:0% +the plank mass then you count the +wavelength of course n than + + align:start position:0% + + + + align:start position:0% + +LP but when this is greater than + + align:start position:0% +LP but when this is greater than + + + align:start position:0% +LP but when this is greater than +MP then then as we discussed here then + + align:start position:0% +MP then then as we discussed here then + + + align:start position:0% +MP then then as we discussed here then +the swater radius of corresponding + + align:start position:0% +the swater radius of corresponding + + + align:start position:0% +the swater radius of corresponding +object will be greater + + align:start position:0% +object will be greater + + + align:start position:0% +object will be greater +than the the the plunk + + align:start position:0% +than the the the plunk + + + align:start position:0% +than the the the plunk +side and will will greater than the comp + + align:start position:0% +side and will will greater than the comp + + + align:start position:0% +side and will will greater than the comp +wavelength and will be greater than the + + align:start position:0% +wavelength and will be greater than the + + + align:start position:0% +wavelength and will be greater than the +uh uh plank + + align:start position:0% +uh uh plank + + + align:start position:0% +uh uh plank +sides and this give you essentially the + + align:start position:0% +sides and this give you essentially the + + + align:start position:0% +sides and this give you essentially the +uh the minimum radius to Pro + + align:start position:0% +uh the minimum radius to Pro + + + align:start position:0% +uh the minimum radius to Pro +okay and uh so so in alternatively we + + align:start position:0% +okay and uh so so in alternatively we + + + align:start position:0% +okay and uh so so in alternatively we +can also + + align:start position:0% +can also + + + align:start position:0% +can also +just reach the same + + align:start position:0% +just reach the same + + + align:start position:0% +just reach the same +argument uh uh simply I can just write + + align:start position:0% +argument uh uh simply I can just write + + + align:start position:0% +argument uh uh simply I can just write +down a couple of equations so let's + + align:start position:0% +down a couple of equations so let's + + + align:start position:0% +down a couple of equations so let's +consider you have + + align:start position:0% + + + + align:start position:0% + +uncertainty say suppose you have a + + align:start position:0% +uncertainty say suppose you have a + + + align:start position:0% +uncertainty say suppose you have a +position uncertainty data + + align:start position:0% +position uncertainty data + + + align:start position:0% +position uncertainty data +X + + align:start position:0% +X + + + align:start position:0% +X +okay and then the then the + + align:start position:0% +okay and then the then the + + + align:start position:0% +okay and then the then the +the uncertainty energy or momentum + + align:start position:0% +the uncertainty energy or momentum + + + align:start position:0% +the uncertainty energy or momentum +associated with the this Delta s is + + align:start position:0% +associated with the this Delta s is + + + align:start position:0% +associated with the this Delta s is +Delta + + align:start position:0% + + + + align:start position:0% + +P but on the other hand the distance you + + align:start position:0% +P but on the other hand the distance you + + + align:start position:0% +P but on the other hand the distance you +can + + align:start position:0% +can + + + align:start position:0% +can +prop must be greater + + align:start position:0% +prop must be greater + + + align:start position:0% +prop must be greater +than then the SWAT radius associate with + + align:start position:0% +than then the SWAT radius associate with + + + align:start position:0% +than then the SWAT radius associate with +LP Delta + + align:start position:0% + + + + align:start position:0% + +P okay Delta p + + align:start position:0% +P okay Delta p + + + align:start position:0% +P okay Delta p +so so if you combine this two equation + + align:start position:0% +so so if you combine this two equation + + + align:start position:0% +so so if you combine this two equation +together so this is greater than + + align:start position:0% + + + + align:start position:0% + +GN H bar divided by Del P so so now I + + align:start position:0% +GN H bar divided by Del P so so now I + + + align:start position:0% +GN H bar divided by Del P so so now I +have suppressed the C so you can see + + align:start position:0% +have suppressed the C so you can see + + + align:start position:0% +have suppressed the C so you can see +from this equation you can see that + + align:start position:0% +from this equation you can see that + + + align:start position:0% +from this equation you can see that +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X must be greater + + align:start position:0% +X must be greater + + + align:start position:0% +X must be greater +than H bar + + align:start position:0% +than H bar + + + align:start position:0% +than H bar +GM which is + + align:start position:0% +GM which is + + + align:start position:0% +GM which is +LP + + align:start position:0% +LP + + + align:start position:0% +LP +okay which is the lp here + + align:start position:0% + + + + align:start position:0% + +yeah this is the same argument as this + + align:start position:0% +yeah this is the same argument as this + + + align:start position:0% +yeah this is the same argument as this +one uh but this is a little bit formal + + align:start position:0% +one uh but this is a little bit formal + + + align:start position:0% +one uh but this is a little bit formal +and so so the essence is that once your + + align:start position:0% +and so so the essence is that once your + + + align:start position:0% +and so so the essence is that once your +energy is big enough then you create a + + align:start position:0% +energy is big enough then you create a + + + align:start position:0% +energy is big enough then you create a +black hole and then your physics will + + align:start position:0% +black hole and then your physics will + + + align:start position:0% +black hole and then your physics will +completely change + + align:start position:0% + + + + align:start position:0% + +okay black hole evaporate so they not + + align:start position:0% +okay black hole evaporate so they not + + + align:start position:0% +okay black hole evaporate so they not +cont + + align:start position:0% +cont + + + align:start position:0% +cont +information right yeah so uh uh we yeah + + align:start position:0% +information right yeah so uh uh we yeah + + + align:start position:0% +information right yeah so uh uh we yeah +let's uh uh uh uh uh uh yeah we will go + + align:start position:0% +let's uh uh uh uh uh uh yeah we will go + + + align:start position:0% +let's uh uh uh uh uh uh yeah we will go +into that uh when the Black ho evaporate + + align:start position:0% +into that uh when the Black ho evaporate + + + align:start position:0% +into that uh when the Black ho evaporate +actually you still don't probe the short + + align:start position:0% +actually you still don't probe the short + + + align:start position:0% +actually you still don't probe the short +still harder to Pro the short distance + + align:start position:0% +still harder to Pro the short distance + + + align:start position:0% +still harder to Pro the short distance +scale because if I yeah we will talk + + align:start position:0% +scale because if I yeah we will talk + + + align:start position:0% +scale because if I yeah we will talk +about that later + + align:start position:0% +about that later + + + align:start position:0% +about that later +yeah so yeah here just a heric argument + + align:start position:0% +yeah so yeah here just a heric argument + + + align:start position:0% +yeah so yeah here just a heric argument +to tell you that the because of + + align:start position:0% +to tell you that the because of + + + align:start position:0% +to tell you that the because of +this the actually uh the physic is very + + align:start position:0% +this the actually uh the physic is very + + + align:start position:0% +this the actually uh the physic is very +special okay uh uh the the physic of the + + align:start position:0% +special okay uh uh the the physic of the + + + align:start position:0% +special okay uh uh the the physic of the +gravity is very special + + align:start position:0% + + + + align:start position:0% + +any other + + align:start position:0% + + + + align:start position:0% + +questions yes um so as a pro for Ming + + align:start position:0% +questions yes um so as a pro for Ming + + + align:start position:0% +questions yes um so as a pro for Ming +gravity I was thinking what if there + + align:start position:0% +gravity I was thinking what if there + + + align:start position:0% +gravity I was thinking what if there +were some um phenomenon in which gravity + + align:start position:0% +were some um phenomenon in which gravity + + + align:start position:0% +were some um phenomenon in which gravity +is weak but and it's a macroscopic scale + + align:start position:0% +is weak but and it's a macroscopic scale + + + align:start position:0% +is weak but and it's a macroscopic scale +but there's some kind of um coherence + + align:start position:0% +but there's some kind of um coherence + + + align:start position:0% +but there's some kind of um coherence +happening that will maybe on the scale + + align:start position:0% +happening that will maybe on the scale + + + align:start position:0% +happening that will maybe on the scale +of galaxies or something like that that + + align:start position:0% +of galaxies or something like that that + + + align:start position:0% +of galaxies or something like that that +will allow Quantum effects to be me + + align:start position:0% +will allow Quantum effects to be me + + + align:start position:0% +will allow Quantum effects to be me +like an analogy of what happens in a + + align:start position:0% +like an analogy of what happens in a + + + align:start position:0% +like an analogy of what happens in a +laser or something like that + + align:start position:0% +laser or something like that + + + align:start position:0% +laser or something like that +um yeah uh that is black hole the black + + align:start position:0% +um yeah uh that is black hole the black + + + align:start position:0% +um yeah uh that is black hole the black +hole is the way which black uh black + + align:start position:0% +hole is the way which black uh black + + + align:start position:0% +hole is the way which black uh black +hole is the way which gravity can + + align:start position:0% +hole is the way which gravity can + + + align:start position:0% +hole is the way which gravity can +manifest the quantum effect at lar + + align:start position:0% +manifest the quantum effect at lar + + + align:start position:0% +manifest the quantum effect at lar +scales and we don't know any other ways + + align:start position:0% +scales and we don't know any other ways + + + align:start position:0% +scales and we don't know any other ways +to for for Gravity to manifest such + + align:start position:0% +to for for Gravity to manifest such + + + align:start position:0% +to for for Gravity to manifest such +quantum physics at large decent scales + + align:start position:0% +quantum physics at large decent scales + + + align:start position:0% +quantum physics at large decent scales +yeah okay so + + align:start position:0% +yeah okay so + + + align:start position:0% +yeah okay so +so so let me conclude this General + + align:start position:0% +so so let me conclude this General + + + align:start position:0% +so so let me conclude this General +discussion Again by reminding + + align:start position:0% +discussion Again by reminding + + + align:start position:0% +discussion Again by reminding +you what is regimes of + + align:start position:0% +you what is regimes of + + + align:start position:0% +you what is regimes of +gravity what is regimes of uh the + + align:start position:0% +gravity what is regimes of uh the + + + align:start position:0% +gravity what is regimes of uh the +gravity or quantum + + align:start position:0% + + + + align:start position:0% + +gravity so + + align:start position:0% + + + + align:start position:0% + +okay so in this + + align:start position:0% +okay so in this + + + align:start position:0% +okay so in this +discussion you should always in the + + align:start position:0% +discussion you should always in the + + + align:start position:0% +discussion you should always in the +discussion I'm going to do in the next + + align:start position:0% +discussion I'm going to do in the next + + + align:start position:0% +discussion I'm going to do in the next +minutes you should + + align:start position:0% +minutes you should + + + align:start position:0% +minutes you should +always think when I take the limit I + + align:start position:0% +always think when I take the limit I + + + align:start position:0% +always think when I take the limit I +always keep my energy fixed okay I keep + + align:start position:0% +always keep my energy fixed okay I keep + + + align:start position:0% +always keep my energy fixed okay I keep +the the energy scale I'm interested in + + align:start position:0% +the the energy scale I'm interested in + + + align:start position:0% +the the energy scale I'm interested in +fixed I keep that fixed okay so the + + align:start position:0% +fixed I keep that fixed okay so the + + + align:start position:0% +fixed I keep that fixed okay so the +classical gravity regime + + align:start position:0% + + + + align:start position:0% + +is the regime which you take H bar go + + align:start position:0% +is the regime which you take H bar go + + + align:start position:0% +is the regime which you take H bar go +zero take the Newton constant + + align:start position:0% +zero take the Newton constant + + + align:start position:0% +zero take the Newton constant +finite + + align:start position:0% +finite + + + align:start position:0% +finite +okay and the regime of a particle + + align:start position:0% +okay and the regime of a particle + + + align:start position:0% +okay and the regime of a particle +physics which normally be sometimes say + + align:start position:0% +physics which normally be sometimes say + + + align:start position:0% +physics which normally be sometimes say +qft in the fixed space + + align:start position:0% + + + + align:start position:0% + +time so this is the Quantum F in the in + + align:start position:0% +time so this is the Quantum F in the in + + + align:start position:0% +time so this is the Quantum F in the in +the fixed space time including curved + + align:start position:0% + + + + align:start position:0% + +okay including cured so this is a regime + + align:start position:0% +okay including cured so this is a regime + + + align:start position:0% +okay including cured so this is a regime +which H bar is + + align:start position:0% +which H bar is + + + align:start position:0% +which H bar is +finite but you take the Newton constant + + align:start position:0% +finite but you take the Newton constant + + + align:start position:0% +finite but you take the Newton constant +go to zero + + align:start position:0% + + + + align:start position:0% + +okay and then there's of course the + + align:start position:0% +okay and then there's of course the + + + align:start position:0% +okay and then there's of course the +quantum gravity + + align:start position:0% + + + + align:start position:0% + +regime which is the GM and H bar both + + align:start position:0% +regime which is the GM and H bar both + + + align:start position:0% +regime which is the GM and H bar both +finite + + align:start position:0% + + + + align:start position:0% + +and there's a very interesting regime + + align:start position:0% +and there's a very interesting regime + + + align:start position:0% +and there's a very interesting regime +which is actually the the regime in most + + align:start position:0% +which is actually the the regime in most + + + align:start position:0% +which is actually the the regime in most +of us work + + align:start position:0% + + + + align:start position:0% + +with so there's also something called + + align:start position:0% +with so there's also something called + + + align:start position:0% +with so there's also something called +the semil classical + + align:start position:0% + + + + align:start position:0% + +regime for quantum + + align:start position:0% +regime for quantum + + + align:start position:0% +regime for quantum +gravity so this is the regime you + + align:start position:0% +gravity so this is the regime you + + + align:start position:0% +gravity so this is the regime you +keep H bar finite + + align:start position:0% + + + + align:start position:0% + +and you + + align:start position:0% + + + + align:start position:0% + +expand you expand the + + align:start position:0% +expand you expand the + + + align:start position:0% +expand you expand the +system in Newton constant + + align:start position:0% +system in Newton constant + + + align:start position:0% +system in Newton constant +okay so around say expand the whatever + + align:start position:0% +okay so around say expand the whatever + + + align:start position:0% +okay so around say expand the whatever +quantity Newton constant + + align:start position:0% +quantity Newton constant + + + align:start position:0% +quantity Newton constant +around say gon equal to + + align:start position:0% +around say gon equal to + + + align:start position:0% +around say gon equal to +zero so gon equal to zero is the + + align:start position:0% +zero so gon equal to zero is the + + + align:start position:0% +zero so gon equal to zero is the +classical reg is the classical regime no + + align:start position:0% +classical reg is the classical regime no + + + align:start position:0% +classical reg is the classical regime no +is the is the uh is the regime the + + align:start position:0% +is the is the uh is the regime the + + + align:start position:0% +is the is the uh is the regime the +gravity is not important but including H + + align:start position:0% +gravity is not important but including H + + + align:start position:0% +gravity is not important but including H +bar and now you can take into + + align:start position:0% +bar and now you can take into + + + align:start position:0% +bar and now you can take into +account the quantum gravity effect + + align:start position:0% +account the quantum gravity effect + + + align:start position:0% +account the quantum gravity effect +semiclassically by expanding around the + + align:start position:0% +semiclassically by expanding around the + + + align:start position:0% +semiclassically by expanding around the +GN okay so this is normally what we call + + align:start position:0% +GN okay so this is normally what we call + + + align:start position:0% +GN okay so this is normally what we call +semiclassical regime of + + align:start position:0% + + + + align:start position:0% + +gravity yes do we know that g goes to Z + + align:start position:0% +gravity yes do we know that g goes to Z + + + align:start position:0% +gravity yes do we know that g goes to Z +the smooth limit + + align:start position:0% +the smooth limit + + + align:start position:0% +the smooth limit +it's not sing Point + + align:start position:0% +it's not sing Point + + + align:start position:0% +it's not sing Point +yeah this is a very good question so so + + align:start position:0% +yeah this is a very good question so so + + + align:start position:0% +yeah this is a very good question so so +this is + + align:start position:0% +this is + + + align:start position:0% +this is +indeed so this is indeed the + + align:start position:0% +indeed so this is indeed the + + + align:start position:0% +indeed so this is indeed the +question uh indeed the most of the + + align:start position:0% +question uh indeed the most of the + + + align:start position:0% +question uh indeed the most of the +puzzles regarding black hole is in this + + align:start position:0% +puzzles regarding black hole is in this + + + align:start position:0% +puzzles regarding black hole is in this +regime so our current understanding of + + align:start position:0% +regime so our current understanding of + + + align:start position:0% +regime so our current understanding of +quantum physics of black ho is in this + + align:start position:0% +quantum physics of black ho is in this + + + align:start position:0% +quantum physics of black ho is in this +semi classical regime and uh you you + + align:start position:0% +semi classical regime and uh you you + + + align:start position:0% +semi classical regime and uh you you +treat the any matter field H bar finite + + align:start position:0% +treat the any matter field H bar finite + + + align:start position:0% +treat the any matter field H bar finite +but the gravity is weak and uh so so + + align:start position:0% +but the gravity is weak and uh so so + + + align:start position:0% +but the gravity is weak and uh so so +there are various indication that this + + align:start position:0% +there are various indication that this + + + align:start position:0% +there are various indication that this +limit is actually not smooth but but + + align:start position:0% +limit is actually not smooth but but + + + align:start position:0% +limit is actually not smooth but but +only for very subtle questions for for + + align:start position:0% +only for very subtle questions for for + + + align:start position:0% +only for very subtle questions for for +gener for simple questions for typical + + align:start position:0% +gener for simple questions for typical + + + align:start position:0% +gener for simple questions for typical +questions actually this is a limit this + + align:start position:0% +questions actually this is a limit this + + + align:start position:0% +questions actually this is a limit this +limit is smooth but they can be very + + align:start position:0% +limit is smooth but they can be very + + + align:start position:0% +limit is smooth but they can be very +subtle questions which this limit is not + + align:start position:0% +subtle questions which this limit is not + + + align:start position:0% +subtle questions which this limit is not +smooth and one such question is this + + align:start position:0% +smooth and one such question is this + + + align:start position:0% +smooth and one such question is this +so-call black ho information no and + + align:start position:0% +so-call black ho information no and + + + align:start position:0% +so-call black ho information no and +involving and the subtle limit of taking + + align:start position:0% +involving and the subtle limit of taking + + + align:start position:0% +involving and the subtle limit of taking +this uh yeah involving subt of taking + + align:start position:0% +this uh yeah involving subt of taking + + + align:start position:0% +this uh yeah involving subt of taking +this limit + + align:start position:0% +this limit + + + align:start position:0% +this limit +any other + + align:start position:0% + + + + align:start position:0% + +questions okay and this is the regime + + align:start position:0% +questions okay and this is the regime + + + align:start position:0% +questions okay and this is the regime +actually we will work with most okay + + align:start position:0% +actually we will work with most okay + + + align:start position:0% +actually we will work with most okay +this is the regime we will work with + + align:start position:0% +this is the regime we will work with + + + align:start position:0% +this is the regime we will work with +most and so so we will always uh in + + align:start position:0% +most and so so we will always uh in + + + align:start position:0% +most and so so we will always uh in +particular later so right now I'm + + align:start position:0% +particular later so right now I'm + + + align:start position:0% +particular later so right now I'm +keeping the H bar explicited but later I + + align:start position:0% +keeping the H bar explicited but later I + + + align:start position:0% +keeping the H bar explicited but later I +will also set H bar equal to one and so + + align:start position:0% +will also set H bar equal to one and so + + + align:start position:0% +will also set H bar equal to one and so +H bar will equal to so we always + + align:start position:0% +H bar will equal to so we always + + + align:start position:0% +H bar will equal to so we always +typically work with this regime H bar + + align:start position:0% +typically work with this regime H bar + + + align:start position:0% +typically work with this regime H bar +equal to one and then you will have + + align:start position:0% +equal to one and then you will have + + + align:start position:0% +equal to one and then you will have +uh um uh + + align:start position:0% +uh um uh + + + align:start position:0% +uh um uh +uh yeah then then you take into account + + align:start position:0% +uh yeah then then you take into account + + + align:start position:0% +uh yeah then then you take into account +the effect of GN uh in the peration + + align:start position:0% +the effect of GN uh in the peration + + + align:start position:0% +the effect of GN uh in the peration +theory + + align:start position:0% + + + + align:start position:0% + +okay good good so now let's move to the + + align:start position:0% +okay good good so now let's move to the + + + align:start position:0% +okay good good so now let's move to the +black hole okay so with + + align:start position:0% +black hole okay so with + + + align:start position:0% +black hole okay so with +this uh yes just some random top do + + align:start position:0% +this uh yes just some random top do + + + align:start position:0% +this uh yes just some random top do +people also work in the other semic reg + + align:start position:0% +people also work in the other semic reg + + + align:start position:0% +people also work in the other semic reg +I mean finite butand HR yeah this is not + + align:start position:0% +I mean finite butand HR yeah this is not + + + align:start position:0% +I mean finite butand HR yeah this is not +um + + align:start position:0% +um + + + align:start position:0% +um +um not so much um it's because the + + align:start position:0% +um not so much um it's because the + + + align:start position:0% +um not so much um it's because the +um it's because it's easy in some sense + + align:start position:0% +um it's because it's easy in some sense + + + align:start position:0% +um it's because it's easy in some sense +it's + + align:start position:0% +it's + + + align:start position:0% +it's +easy so so in the sense we are doing a + + align:start position:0% +easy so so in the sense we are doing a + + + align:start position:0% +easy so so in the sense we are doing a +little bit both uh uh + + align:start position:0% +little bit both uh uh + + + align:start position:0% +little bit both uh uh +so yeah so later right now I don't want + + align:start position:0% +so yeah so later right now I don't want + + + align:start position:0% +so yeah so later right now I don't want +to go into that you will see the + + align:start position:0% +to go into that you will see the + + + align:start position:0% +to go into that you will see the +effective uh the effective coupling + + align:start position:0% +effective uh the effective coupling + + + align:start position:0% +effective uh the effective coupling +constant control the the quantum gravity + + align:start position:0% +constant control the the quantum gravity + + + align:start position:0% +constant control the the quantum gravity +effect is in fact the H Bar times + + align:start position:0% +effect is in fact the H Bar times + + + align:start position:0% +effect is in fact the H Bar times +GN is H Bar times GN and so so the + + align:start position:0% +GN is H Bar times GN and so so the + + + align:start position:0% +GN is H Bar times GN and so so the +quantum gravity effect will be important + + align:start position:0% +quantum gravity effect will be important + + + align:start position:0% +quantum gravity effect will be important +when the H Bar times when you do + + align:start position:0% +when the H Bar times when you do + + + align:start position:0% +when the H Bar times when you do +putation Ser in h Bar times GN yeah yeah + + align:start position:0% +putation Ser in h Bar times GN yeah yeah + + + align:start position:0% +putation Ser in h Bar times GN yeah yeah +so when I say uh you are doing things in + + align:start position:0% +so when I say uh you are doing things in + + + align:start position:0% +so when I say uh you are doing things in +GN essentially because I'm fixing H bar + + align:start position:0% +GN essentially because I'm fixing H bar + + + align:start position:0% +GN essentially because I'm fixing H bar +so you're actually doing pation Theory H + + align:start position:0% +so you're actually doing pation Theory H + + + align:start position:0% +so you're actually doing pation Theory H +bar GN yeah so you have to do both yeah + + align:start position:0% +bar GN yeah so you have to do both yeah + + + align:start position:0% +bar GN yeah so you have to do both yeah +any other + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +right so now let's talk about the black + + align:start position:0% + + + + align:start position:0% + +hole so let's first talk about classical + + align:start position:0% +hole so let's first talk about classical + + + align:start position:0% +hole so let's first talk about classical +geometry + + align:start position:0% + + + + align:start position:0% + +okay so here will assume you already + + align:start position:0% +okay so here will assume you already + + + align:start position:0% +okay so here will assume you already +have some background in GR in + + align:start position:0% +have some background in GR in + + + align:start position:0% +have some background in GR in +generativity and for example you have + + align:start position:0% +generativity and for example you have + + + align:start position:0% +generativity and for example you have +seen things like swashi matric + + align:start position:0% +seen things like swashi matric + + + align:start position:0% +seen things like swashi matric +Etc and if you have not seen swashi + + align:start position:0% +Etc and if you have not seen swashi + + + align:start position:0% +Etc and if you have not seen swashi +matric it's also okay uh um I think uh + + align:start position:0% +matric it's also okay uh um I think uh + + + align:start position:0% +matric it's also okay uh um I think uh +uh you should be able to uh to follow uh + + align:start position:0% +uh you should be able to uh to follow uh + + + align:start position:0% +uh you should be able to uh to follow uh +uh what I'm going to say so so for + + align:start position:0% +uh what I'm going to say so so for + + + align:start position:0% +uh what I'm going to say so so for +Simplicity let me consider zero cos mod + + align:start position:0% + + + + align:start position:0% + +constant okay zero cosmology constant + + align:start position:0% +constant okay zero cosmology constant + + + align:start position:0% +constant okay zero cosmology constant +cosmological + + align:start position:0% + + + + align:start position:0% + +constant okay Z cosmological constant + + align:start position:0% +constant okay Z cosmological constant + + + align:start position:0% +constant okay Z cosmological constant +corresponding to we can see the SYM + + align:start position:0% +corresponding to we can see the SYM + + + align:start position:0% +corresponding to we can see the SYM +totically um minkovski space + + align:start position:0% +totically um minkovski space + + + align:start position:0% +totically um minkovski space +time and uh so so in the space time of + + align:start position:0% +time and uh so so in the space time of + + + align:start position:0% +time and uh so so in the space time of +zero coso constant and then the space + + align:start position:0% +zero coso constant and then the space + + + align:start position:0% +zero coso constant and then the space +time + + align:start position:0% + + + + align:start position:0% + +matric due + + align:start position:0% +matric due + + + align:start position:0% +matric due +to an + + align:start position:0% + + + + align:start position:0% + +object of mass + + align:start position:0% + + + + align:start position:0% + +m + + align:start position:0% +m + + + align:start position:0% +m +okay can be written as + + align:start position:0% + + + + align:start position:0% + +so this is + + align:start position:0% + + + + align:start position:0% + +the famous was magic + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay and uh so so of course here we are + + align:start position:0% + + + + align:start position:0% + +assuming this is a a SP + + align:start position:0% + + + + align:start position:0% + +metric and the neutral ex there's not + + align:start position:0% +metric and the neutral ex there's not + + + align:start position:0% +metric and the neutral ex there's not +say this all object does not carry any + + align:start position:0% + + + + align:start position:0% + +charge and then this m and this + + align:start position:0% + + + + align:start position:0% + +F is given by 1 - 2 + + align:start position:0% +F is given by 1 - 2 + + + align:start position:0% +F is given by 1 - 2 +n m/ r or is equal to r s/ r okay so + + align:start position:0% +n m/ r or is equal to r s/ r okay so + + + align:start position:0% +n m/ r or is equal to r s/ r okay so +this RS is the SW radius so now C is + + align:start position:0% +this RS is the SW radius so now C is + + + align:start position:0% +this RS is the SW radius so now C is +always equal to + + align:start position:0% +always equal to + + + align:start position:0% +always equal to +one + + align:start position:0% + + + + align:start position:0% + +okay so if this + + align:start position:0% +okay so if this + + + align:start position:0% +okay so if this +object so we consider this object is + + align:start position:0% +object so we consider this object is + + + align:start position:0% +object so we consider this object is +verical symmetric if this object have a + + align:start position:0% +verical symmetric if this object have a + + + align:start position:0% +verical symmetric if this object have a +fight + + align:start position:0% + + + + align:start position:0% + +sides then then of course this matric + + align:start position:0% +sides then then of course this matric + + + align:start position:0% +sides then then of course this matric +only is valid outside this object + + align:start position:0% +only is valid outside this object + + + align:start position:0% +only is valid outside this object +okay but if the side of this + + align:start position:0% +okay but if the side of this + + + align:start position:0% +okay but if the side of this +object is + + align:start position:0% +object is + + + align:start position:0% +object is +smaller than this wasal radius then this + + align:start position:0% +smaller than this wasal radius then this + + + align:start position:0% +smaller than this wasal radius then this +is a black hole okay and the black hole + + align:start position:0% +is a black hole okay and the black hole + + + align:start position:0% +is a black hole okay and the black hole +is + + align:start position:0% +is + + + align:start position:0% +is +distinguished by even Horizon + + align:start position:0% + + + + align:start position:0% + +at I to r + + align:start position:0% +at I to r + + + align:start position:0% +at I to r +s okay at I to i s so at I to i s you + + align:start position:0% +s okay at I to i s so at I to i s you + + + align:start position:0% +s okay at I to i s so at I to i s you +you see that this F become + + align:start position:0% +you see that this F become + + + align:start position:0% +you see that this F become +zero okay so FAL become zero so + + align:start position:0% +zero okay so FAL become zero so + + + align:start position:0% +zero okay so FAL become zero so +essentially and here + + align:start position:0% +essentially and here + + + align:start position:0% +essentially and here +gtt so the metric for the TT compon + + align:start position:0% +gtt so the metric for the TT compon + + + align:start position:0% +gtt so the metric for the TT compon +component is become + + align:start position:0% +component is become + + + align:start position:0% +component is become +zero and + + align:start position:0% +zero and + + + align:start position:0% +zero and +grr the matric before the the r + + align:start position:0% +grr the matric before the the r + + + align:start position:0% +grr the matric before the the r +component it become + + align:start position:0% +component it become + + + align:start position:0% +component it become +infinite + + align:start position:0% + + + + align:start position:0% + +okay and another thing is that when R + + align:start position:0% +okay and another thing is that when R + + + align:start position:0% +okay and another thing is that when R +become smaller than + + align:start position:0% + + + + align:start position:0% + +RS then F switch sign + + align:start position:0% + + + + align:start position:0% + +so s become + + align:start position:0% +so s become + + + align:start position:0% +so s become +negative and then in this case then R + + align:start position:0% +negative and then in this case then R + + + align:start position:0% +negative and then in this case then R +become time coordinates then the T + + align:start position:0% +become time coordinates then the T + + + align:start position:0% +become time coordinates then the T +become spatial coordinates okay when you + + align:start position:0% +become spatial coordinates okay when you + + + align:start position:0% +become spatial coordinates okay when you +go inside the IAL to i + + align:start position:0% +go inside the IAL to i + + + align:start position:0% +go inside the IAL to i +s okay this is just a feature of this + + align:start position:0% + + + + align:start position:0% + +matric so now let me say some simple uh + + align:start position:0% +matric so now let me say some simple uh + + + align:start position:0% +matric so now let me say some simple uh +now let me uh list some uh uh some + + align:start position:0% +now let me uh list some uh uh some + + + align:start position:0% +now let me uh list some uh uh some +facts about this magic + + align:start position:0% + + + + align:start position:0% + +so most of them I expect to be + + align:start position:0% +so most of them I expect to be + + + align:start position:0% +so most of them I expect to be +low actually I I expect to be low all of + + align:start position:0% + + + + align:start position:0% + +them but it's + + align:start position:0% +them but it's + + + align:start position:0% +them but it's +um just remind + + align:start position:0% +um just remind + + + align:start position:0% +um just remind +you some of those facts will be + + align:start position:0% +you some of those facts will be + + + align:start position:0% +you some of those facts will be +important + + align:start position:0% +important + + + align:start position:0% +important +later okay + + align:start position:0% + + + + align:start position:0% + +so these are mostly + + align:start position:0% + + + + align:start position:0% + +reminders so first this + + align:start position:0% + + + + align:start position:0% + +matric if you look at this Matrix + + align:start position:0% +matric if you look at this Matrix + + + align:start position:0% +matric if you look at this Matrix +itself is time reversal in + + align:start position:0% + + + + align:start position:0% + +warrant + + align:start position:0% +warrant + + + align:start position:0% +warrant +okay because you can if you take T go to + + align:start position:0% +okay because you can if you take T go to + + + align:start position:0% +okay because you can if you take T go to +minus + + align:start position:0% +minus + + + align:start position:0% +minus +t of course the uh uh yeah envirment on + + align:start position:0% +t of course the uh uh yeah envirment on + + + align:start position:0% +t of course the uh uh yeah envirment on +the T goes minus + + align:start position:0% +the T goes minus + + + align:start position:0% +the T goes minus +t + + align:start position:0% +t + + + align:start position:0% +t +Okay so this actually because of this + + align:start position:0% +Okay so this actually because of this + + + align:start position:0% +Okay so this actually because of this +this cannot describe a real black hole + + align:start position:0% +this cannot describe a real black hole + + + align:start position:0% +this cannot describe a real black hole +so the real life black hole + + align:start position:0% +so the real life black hole + + + align:start position:0% +so the real life black hole +arise from gravitational collapse and + + align:start position:0% +arise from gravitational collapse and + + + align:start position:0% +arise from gravitational collapse and +the gravitational collapse cannot be a + + align:start position:0% +the gravitational collapse cannot be a + + + align:start position:0% +the gravitational collapse cannot be a +time symmetric process okay so this + + align:start position:0% +time symmetric process okay so this + + + align:start position:0% +time symmetric process okay so this +cannot describe so this does not + + align:start position:0% +cannot describe so this does not + + + align:start position:0% +cannot describe so this does not +describe a real black + + align:start position:0% +describe a real black + + + align:start position:0% +describe a real black +ho but it's a good approximation to the + + align:start position:0% +ho but it's a good approximation to the + + + align:start position:0% +ho but it's a good approximation to the +real life black hole after this object + + align:start position:0% +real life black hole after this object + + + align:start position:0% +real life black hole after this object +have stabilized so after the + + align:start position:0% +have stabilized so after the + + + align:start position:0% +have stabilized so after the +gravitational collapse has + + align:start position:0% +gravitational collapse has + + + align:start position:0% +gravitational collapse has +finished um yeah so this is the + + align:start position:0% +finished um yeah so this is the + + + align:start position:0% +finished um yeah so this is the +um so this is a mathematical in some + + align:start position:0% +um so this is a mathematical in some + + + align:start position:0% +um so this is a mathematical in some +sense it's a + + align:start position:0% +sense it's a + + + align:start position:0% +sense it's a +mathematical + + align:start position:0% + + + + align:start position:0% + +idealization of real + + align:start position:0% + + + + align:start position:0% + +life back ho + + align:start position:0% + + + + align:start position:0% + +okay so this is first + + align:start position:0% + + + + align:start position:0% + +remark so the second + + align:start position:0% +remark so the second + + + align:start position:0% +remark so the second +remark is that despite this grr goes + + align:start position:0% +remark is that despite this grr goes + + + align:start position:0% +remark is that despite this grr goes +Infinity this MATC component goes + + align:start position:0% +Infinity this MATC component goes + + + align:start position:0% +Infinity this MATC component goes +Infinity so the space + + align:start position:0% + + + + align:start position:0% + +time is non single Horizon + + align:start position:0% + + + + align:start position:0% + +okay so you can check it by Computing + + align:start position:0% +okay so you can check it by Computing + + + align:start position:0% +okay so you can check it by Computing +say curvature + + align:start position:0% +say curvature + + + align:start position:0% +say curvature +invariant of this metric you find none + + align:start position:0% +invariant of this metric you find none + + + align:start position:0% +invariant of this metric you find none +of the all the curvature in warant they + + align:start position:0% +of the all the curvature in warant they + + + align:start position:0% +of the all the curvature in warant they +are well + + align:start position:0% +are well + + + align:start position:0% +are well +defined so so this Horizon is just a + + align:start position:0% +defined so so this Horizon is just a + + + align:start position:0% +defined so so this Horizon is just a +coordinate uh you can show that this + + align:start position:0% +coordinate uh you can show that this + + + align:start position:0% +coordinate uh you can show that this +corizon just a coordinate singularity + + align:start position:0% + + + + align:start position:0% + +which we + + align:start position:0% +which we + + + align:start position:0% +which we +C actually we will see it + + align:start position:0% +C actually we will see it + + + align:start position:0% +C actually we will see it +maybe in next lecture or or maybe at the + + align:start position:0% +maybe in next lecture or or maybe at the + + + align:start position:0% +maybe in next lecture or or maybe at the +end of today's lecture that it just this + + align:start position:0% +end of today's lecture that it just this + + + align:start position:0% +end of today's lecture that it just this +coordinates R and the T coordinate + + align:start position:0% +coordinates R and the T coordinate + + + align:start position:0% +coordinates R and the T coordinate +become singular the coordinate cell + + align:start position:0% +become singular the coordinate cell + + + align:start position:0% +become singular the coordinate cell +become singular + + align:start position:0% + + + + align:start position:0% + +okay so this T we normally call it swash + + align:start position:0% +okay so this T we normally call it swash + + + align:start position:0% +okay so this T we normally call it swash +your + + align:start position:0% +your + + + align:start position:0% +your +time so let me just introduce the L so + + align:start position:0% +time so let me just introduce the L so + + + align:start position:0% +time so let me just introduce the L so +this T we call the swash your time + + align:start position:0% + + + + align:start position:0% + +so swash found a this solution while + + align:start position:0% +so swash found a this solution while + + + align:start position:0% +so swash found a this solution while +fighting first world + + align:start position:0% + + + + align:start position:0% + +war in the really in the + + align:start position:0% +war in the really in the + + + align:start position:0% +war in the really in the +battlefield and uh and a couple months + + align:start position:0% +battlefield and uh and a couple months + + + align:start position:0% +battlefield and uh and a couple months +after he finished this metric he he he + + align:start position:0% +after he finished this metric he he he + + + align:start position:0% +after he finished this metric he he he +died from some + + align:start position:0% + + + + align:start position:0% + +disease right this is that + + align:start position:0% + + + + align:start position:0% + +so so L + + align:start position:0% +so so L + + + align:start position:0% +so so L +thing you can easily check + + align:start position:0% +thing you can easily check + + + align:start position:0% +thing you can easily check +yourself that IAL to RS The Horizon is a + + align:start position:0% +yourself that IAL to RS The Horizon is a + + + align:start position:0% +yourself that IAL to RS The Horizon is a +LW + + align:start position:0% + + + + align:start position:0% + +surface it's a not hypers + + align:start position:0% + + + + align:start position:0% + +surface so nor hypers Surface by now + + align:start position:0% +surface so nor hypers Surface by now + + + align:start position:0% +surface so nor hypers Surface by now +hypersurface just say this surface + + align:start position:0% +hypersurface just say this surface + + + align:start position:0% +hypersurface just say this surface +contains + + align:start position:0% +contains + + + align:start position:0% +contains +now + + align:start position:0% +now + + + align:start position:0% +now +contain + + align:start position:0% +contain + + + align:start position:0% +contain +um geodesics which allow + + align:start position:0% + + + + align:start position:0% + +okay and this is a the thir remark is + + align:start position:0% +okay and this is a the thir remark is + + + align:start position:0% +okay and this is a the thir remark is +extremely important one which we + + align:start position:0% +extremely important one which we + + + align:start position:0% +extremely important one which we +will use many times in the + + align:start position:0% +will use many times in the + + + align:start position:0% +will use many times in the +future is that the + + align:start position:0% +future is that the + + + align:start position:0% +future is that the +Horizon is a surface + + align:start position:0% + + + + align:start position:0% + +of infinite R + + align:start position:0% + + + + align:start position:0% + +shift compared to + + align:start position:0% +shift compared to + + + align:start position:0% +shift compared to +the infinite red + + align:start position:0% + + + + align:start position:0% + +shift from the perspective of Observer + + align:start position:0% +shift from the perspective of Observer + + + align:start position:0% +shift from the perspective of Observer +at Infinity + + align:start position:0% +at Infinity + + + align:start position:0% +at Infinity +okay so let me save time not to add this + + align:start position:0% +okay so let me save time not to add this + + + align:start position:0% +okay so let me save time not to add this +qualifying remark from from the + + align:start position:0% +qualifying remark from from the + + + align:start position:0% +qualifying remark from from the +perspective of the observe by + + align:start position:0% +perspective of the observe by + + + align:start position:0% +perspective of the observe by +Infinity so so let me just illustrate + + align:start position:0% +Infinity so so let me just illustrate + + + align:start position:0% +Infinity so so let me just illustrate +this point + + align:start position:0% +this point + + + align:start position:0% +this point +a little bit more + + align:start position:0% +a little bit more + + + align:start position:0% +a little bit more +explicitly so let's consider + + align:start position:0% + + + + align:start position:0% + +Observer consider an + + align:start position:0% + + + + align:start position:0% + +observer so let me call + + align:start position:0% +observer so let me call + + + align:start position:0% +observer so let me call +O so this is at some hypers surface R + + align:start position:0% +O so this is at some hypers surface R + + + align:start position:0% +O so this is at some hypers surface R +which is close + + align:start position:0% +which is close + + + align:start position:0% +which is close +to + + align:start position:0% +to + + + align:start position:0% +to +Horizon yeah uh some say some as some + + align:start position:0% +Horizon yeah uh some say some as some + + + align:start position:0% +Horizon yeah uh some say some as some +place which is close to the Horizon + + align:start position:0% + + + + align:start position:0% + +okay slightly outside + + align:start position:0% +okay slightly outside + + + align:start position:0% +okay slightly outside +Horizon and let's consider another + + align:start position:0% +Horizon and let's consider another + + + align:start position:0% +Horizon and let's consider another +Observer which I call O + + align:start position:0% +Observer which I call O + + + align:start position:0% +Observer which I call O +Infinity which + + align:start position:0% +Infinity which + + + align:start position:0% +Infinity which +add I equal to + + align:start position:0% +add I equal to + + + align:start position:0% +add I equal to +Infinity okay very far away from the + + align:start position:0% +Infinity okay very far away from the + + + align:start position:0% +Infinity okay very far away from the +black + + align:start position:0% +black + + + align:start position:0% +black +hole so at so let's first look at this + + align:start position:0% +hole so at so let's first look at this + + + align:start position:0% +hole so at so let's first look at this +Observer + + align:start position:0% +Observer + + + align:start position:0% +Observer +so I equal to + + align:start position:0% + + + + align:start position:0% + +Infinity then your + + align:start position:0% +Infinity then your + + + align:start position:0% +Infinity then your +matric so at I go to Infinity this F + + align:start position:0% +matric so at I go to Infinity this F + + + align:start position:0% +matric so at I go to Infinity this F +just become one because when you R go to + + align:start position:0% +just become one because when you R go to + + + align:start position:0% +just become one because when you R go to +Infinity this R just become one and then + + align:start position:0% +Infinity this R just become one and then + + + align:start position:0% +Infinity this R just become one and then +this become the standard + + align:start position:0% +this become the standard + + + align:start position:0% +this become the standard +minkovski space time written in the + + align:start position:0% +minkovski space time written in the + + + align:start position:0% +minkovski space time written in the +spherical + + align:start position:0% + + + + align:start position:0% + +coordinates so so we just have + + align:start position:0% + + + + align:start position:0% + +yeah just standard the mosi's time + + align:start position:0% +yeah just standard the mosi's time + + + align:start position:0% +yeah just standard the mosi's time +written the spical + + align:start position:0% +written the spical + + + align:start position:0% +written the spical +coordinates and uh and from here you can + + align:start position:0% +coordinates and uh and from here you can + + + align:start position:0% +coordinates and uh and from here you can +immediately see so this T this what we + + align:start position:0% +immediately see so this T this what we + + + align:start position:0% +immediately see so this T this what we +call swal time T is the proper + + align:start position:0% + + + + align:start position:0% + +time for this observe at Infinity say + + align:start position:0% +time for this observe at Infinity say + + + align:start position:0% +time for this observe at Infinity say +for all + + align:start position:0% +for all + + + align:start position:0% +for all +Infinity + + align:start position:0% +Infinity + + + align:start position:0% +Infinity +okay so now let's look + + align:start position:0% +okay so now let's look + + + align:start position:0% +okay so now let's look +at at some some place IAL to + + align:start position:0% + + + + align:start position:0% + +RH so at IAL to + + align:start position:0% + + + + align:start position:0% + +RH then the the matric is given by minus + + align:start position:0% +RH then the the matric is given by minus + + + align:start position:0% +RH then the the matric is given by minus +F + + align:start position:0% +F + + + align:start position:0% +F +RH DT + + align:start position:0% +RH DT + + + align:start position:0% +RH DT +s with the + + align:start position:0% +s with the + + + align:start position:0% +s with the +rest + + align:start position:0% +rest + + + align:start position:0% +rest +okay and to to define the proper + + align:start position:0% +okay and to to define the proper + + + align:start position:0% +okay and to to define the proper +time for The Observer at we can just + + align:start position:0% +time for The Observer at we can just + + + align:start position:0% +time for The Observer at we can just +directly write it as minus d square so + + align:start position:0% +directly write it as minus d square so + + + align:start position:0% +directly write it as minus d square so +that's the prop time observed by + + align:start position:0% +that's the prop time observed by + + + align:start position:0% +that's the prop time observed by +Observer at this + + align:start position:0% +Observer at this + + + align:start position:0% +Observer at this +hypersurface okay so so then we conclude + + align:start position:0% +hypersurface okay so so then we conclude + + + align:start position:0% +hypersurface okay so so then we conclude +so let me call it to H so we conclude + + align:start position:0% +so let me call it to H so we conclude + + + align:start position:0% +so let me call it to H so we conclude +that the proper time at for + + align:start position:0% + + + + align:start position:0% + +o is given by + + align:start position:0% +o is given by + + + align:start position:0% +o is given by +F12 I RH * + + align:start position:0% +F12 I RH * + + + align:start position:0% +F12 I RH * +DT okay so relates to the proper time at + + align:start position:0% +DT okay so relates to the proper time at + + + align:start position:0% +DT okay so relates to the proper time at +Infinity by this Factor + + align:start position:0% + + + + align:start position:0% + +so so if I write it more explicitly so + + align:start position:0% +so so if I write it more explicitly so + + + align:start position:0% +so so if I write it more explicitly so +this is 1 minus RH / by RS 12 * + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +DT so we see that + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so we see that + + align:start position:0% +so we see that + + + align:start position:0% +so we see that +as RH suppose this + + align:start position:0% +as RH suppose this + + + align:start position:0% +as RH suppose this +Observer the location of this Ober the + + align:start position:0% +Observer the location of this Ober the + + + align:start position:0% +Observer the location of this Ober the +the location of this Observer approach + + align:start position:0% +the location of this Observer approach + + + align:start position:0% +the location of this Observer approach +The + + align:start position:0% + + + + align:start position:0% + +Horizon say if I H approaches to + + align:start position:0% +Horizon say if I H approaches to + + + align:start position:0% +Horizon say if I H approaches to +is then this d h + + align:start position:0% +is then this d h + + + align:start position:0% +is then this d h +divid by DT will goes to + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% + + + + align:start position:0% + +okay so so that + + align:start position:0% + + + + align:start position:0% + +means + + align:start position:0% + + + + align:start position:0% + +compare to the time at + + align:start position:0% + + + + align:start position:0% + +Infinity the time + + align:start position:0% +Infinity the time + + + align:start position:0% +Infinity the time +at + + align:start position:0% +at + + + align:start position:0% +at +r equal to r + + align:start position:0% +r equal to r + + + align:start position:0% +r equal to r +s becomes infinite snow okay so so + + align:start position:0% +s becomes infinite snow okay so so + + + align:start position:0% +s becomes infinite snow okay so so +approximate let me say becomes infinite + + align:start position:0% + + + + align:start position:0% + +snow + + align:start position:0% +snow + + + align:start position:0% +snow +okay so that + + align:start position:0% +okay so that + + + align:start position:0% +okay so that +means any finite + + align:start position:0% +means any finite + + + align:start position:0% +means any finite +interval any finite proper time + + align:start position:0% +interval any finite proper time + + + align:start position:0% +interval any finite proper time +interval for Observer at o for this + + align:start position:0% +interval for Observer at o for this + + + align:start position:0% +interval for Observer at o for this +o when you viewed from + + align:start position:0% +o when you viewed from + + + align:start position:0% +o when you viewed from +Infinity uh become infinitely long okay + + align:start position:0% +Infinity uh become infinitely long okay + + + align:start position:0% +Infinity uh become infinitely long okay +become very long time scale okay become + + align:start position:0% +become very long time scale okay become + + + align:start position:0% +become very long time scale okay become +very long time scale so you can also + + align:start position:0% +very long time scale so you can also + + + align:start position:0% +very long time scale so you can also +invert this you can also + + align:start position:0% +invert this you can also + + + align:start position:0% +invert this you can also +invert this + + align:start position:0% +invert this + + + align:start position:0% +invert this +relation okay you can also re invert re + + align:start position:0% +relation okay you can also re invert re + + + align:start position:0% +relation okay you can also re invert re +relation say say suppose some event of + + align:start position:0% + + + + align:start position:0% + +energ with + + align:start position:0% + + + + align:start position:0% + +energ EH with proper + + align:start position:0% + + + + align:start position:0% + +energy with proper + + align:start position:0% +energy with proper + + + align:start position:0% +energy with proper +energy + + align:start position:0% +energy + + + align:start position:0% +energy +eh say for this Observer at o for this + + align:start position:0% +eh say for this Observer at o for this + + + align:start position:0% +eh say for this Observer at o for this +observe o + + align:start position:0% +observe o + + + align:start position:0% +observe o +h then because of this time because of + + align:start position:0% +h then because of this time because of + + + align:start position:0% +h then because of this time because of +the time relation between + + align:start position:0% +the time relation between + + + align:start position:0% +the time relation between +them okay because of the time relation + + align:start position:0% +them okay because of the time relation + + + align:start position:0% +them okay because of the time relation +between + + align:start position:0% +between + + + align:start position:0% +between +them then then from the + + align:start position:0% + + + + align:start position:0% + +perspective from the perspective of this + + align:start position:0% +perspective from the perspective of this + + + align:start position:0% +perspective from the perspective of this +obser + + align:start position:0% + + + + align:start position:0% + +Infinity the + + align:start position:0% +Infinity the + + + align:start position:0% +Infinity the +energe is given just by by you inverted + + align:start position:0% +energe is given just by by you inverted + + + align:start position:0% +energe is given just by by you inverted +viation between the time okay because + + align:start position:0% +viation between the time okay because + + + align:start position:0% +viation between the time okay because +the energy and time conjugate so the E + + align:start position:0% +the energy and time conjugate so the E + + + align:start position:0% +the energy and time conjugate so the E +Infinity e times this F12 + + align:start position:0% +Infinity e times this F12 + + + align:start position:0% +Infinity e times this F12 +RH + + align:start position:0% + + + + align:start position:0% + +okay so so this just again say in the + + align:start position:0% +okay so so this just again say in the + + + align:start position:0% +okay so so this just again say in the +slightly different way that for any + + align:start position:0% +slightly different way that for any + + + align:start position:0% +slightly different way that for any +finite any + + align:start position:0% +finite any + + + align:start position:0% +finite any +finite eh prop noal proper energy okay + + align:start position:0% +finite eh prop noal proper energy okay + + + align:start position:0% +finite eh prop noal proper energy okay +so this is a local proper energy for the + + align:start position:0% +so this is a local proper energy for the + + + align:start position:0% +so this is a local proper energy for the +Observer at o + + align:start position:0% + + + + align:start position:0% + +this e + + align:start position:0% +this e + + + align:start position:0% +this e +Infinity the same event viewed from the + + align:start position:0% +Infinity the same event viewed from the + + + align:start position:0% +Infinity the same event viewed from the +from the perspective of the obser + + align:start position:0% +from the perspective of the obser + + + align:start position:0% +from the perspective of the obser +infinity goes + + align:start position:0% +infinity goes + + + align:start position:0% +infinity goes +zero as I goes to I + + align:start position:0% +zero as I goes to I + + + align:start position:0% +zero as I goes to I +okay so that so that is this is + + align:start position:0% +okay so that so that is this is + + + align:start position:0% +okay so that so that is this is +infinitely ref red + + align:start position:0% + + + + align:start position:0% + +shifted okay become infinite R shift so + + align:start position:0% +shifted okay become infinite R shift so + + + align:start position:0% +shifted okay become infinite R shift so +any process + + align:start position:0% +any process + + + align:start position:0% +any process +so any process with noal proper energy + + align:start position:0% +so any process with noal proper energy + + + align:start position:0% +so any process with noal proper energy +Bu from Infinity corresponding to very + + align:start position:0% +Bu from Infinity corresponding to very + + + align:start position:0% +Bu from Infinity corresponding to very +very low energy process okay so this + + align:start position:0% +very low energy process okay so this + + + align:start position:0% +very low energy process okay so this +actually will play a very important role + + align:start position:0% +actually will play a very important role + + + align:start position:0% +actually will play a very important role +this feature will play very important + + align:start position:0% +this feature will play very important + + + align:start position:0% +this feature will play very important +role when later we talk about + + align:start position:0% +role when later we talk about + + + align:start position:0% +role when later we talk about +holographic Duality and its + + align:start position:0% +holographic Duality and its + + + align:start position:0% +holographic Duality and its +simplification say say for the field + + align:start position:0% + + + + align:start position:0% + +ET yes so this is just a tic comment I + + align:start position:0% +ET yes so this is just a tic comment I + + + align:start position:0% +ET yes so this is just a tic comment I +think you need a minus in Fr of your s + + align:start position:0% +think you need a minus in Fr of your s + + + align:start position:0% +think you need a minus in Fr of your s +just to make sure proper time isn't + + align:start position:0% +just to make sure proper time isn't + + + align:start position:0% +just to make sure proper time isn't +imaginary uh sorry which Mal sign um in + + align:start position:0% +imaginary uh sorry which Mal sign um in + + + align:start position:0% +imaginary uh sorry which Mal sign um in +the you mean + + align:start position:0% +the you mean + + + align:start position:0% +the you mean +here you mean here or here below that + + align:start position:0% +here you mean here or here below that + + + align:start position:0% +here you mean here or here below that +below that below that yeah R iser oh no + + align:start position:0% +below that below that yeah R iser oh no + + + align:start position:0% +below that below that yeah R iser oh no +sorry sorry sorry + + align:start position:0% +sorry sorry sorry + + + align:start position:0% +sorry sorry sorry +sorry thank you I wrote it wrong should + + align:start position:0% +sorry thank you I wrote it wrong should + + + align:start position:0% +sorry thank you I wrote it wrong should +be i s i + + align:start position:0% +be i s i + + + align:start position:0% +be i s i +yeah yeah yeah because I S is above + + align:start position:0% +yeah yeah yeah because I S is above + + + align:start position:0% +yeah yeah yeah because I S is above +sorry yeah so r s is above so I Val as I + + align:start position:0% +sorry yeah so r s is above so I Val as I + + + align:start position:0% +sorry yeah so r s is above so I Val as I +so I is downstairs yeah thank you so so + + align:start position:0% +so I is downstairs yeah thank you so so + + + align:start position:0% +so I is downstairs yeah thank you so so +I stand so I always consider RH is great + + align:start position:0% +I stand so I always consider RH is great + + + align:start position:0% +I stand so I always consider RH is great +equal to r s + + align:start position:0% + + + + align:start position:0% + +okay any other questions + + align:start position:0% + + + + align:start position:0% + +okay and uh so some other fact and again + + align:start position:0% +okay and uh so some other fact and again + + + align:start position:0% +okay and uh so some other fact and again +I will just list + + align:start position:0% +I will just list + + + align:start position:0% +I will just list +them I will just list them if you're not + + align:start position:0% +them I will just list them if you're not + + + align:start position:0% +them I will just list them if you're not +not familiar with them uh it should be + + align:start position:0% +not familiar with them uh it should be + + + align:start position:0% +not familiar with them uh it should be +very easy for you to go through them to + + align:start position:0% +very easy for you to go through them to + + + align:start position:0% +very easy for you to go through them to +rederive them with a little bit + + align:start position:0% +rederive them with a little bit + + + align:start position:0% +rederive them with a little bit +knowledge in + + align:start position:0% + + + + align:start position:0% + +gr so number + + align:start position:0% +gr so number + + + align:start position:0% +gr so number +four is that it takes + + align:start position:0% + + + + align:start position:0% + +a free + + align:start position:0% + + + + align:start position:0% + +four fre four means we just follow + + align:start position:0% +four fre four means we just follow + + + align:start position:0% +four fre four means we just follow +geodesics okay fre four + + align:start position:0% + + + + align:start position:0% + +traveler a finite proper + + align:start position:0% + + + + align:start position:0% + +time to reach the Horizon say from the + + align:start position:0% +time to reach the Horizon say from the + + + align:start position:0% +time to reach the Horizon say from the +infinity + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% + + + + align:start position:0% + +infinite s short + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +okay so so you can easily check that + + align:start position:0% +okay so so you can easily check that + + + align:start position:0% +okay so so you can easily check that +actually take infinite spal time for + + align:start position:0% +actually take infinite spal time for + + + align:start position:0% +actually take infinite spal time for +object to Force Through The Horizon + + align:start position:0% +object to Force Through The Horizon + + + align:start position:0% +object to Force Through The Horizon +but from the from the free four obser + + align:start position:0% +but from the from the free four obser + + + align:start position:0% +but from the from the free four obser +itself it's actually just fin at proper + + align:start position:0% +itself it's actually just fin at proper + + + align:start position:0% +itself it's actually just fin at proper +time and so from the perspective of the + + align:start position:0% +time and so from the perspective of the + + + align:start position:0% +time and so from the perspective of the +Observer and infinity looks like this + + align:start position:0% +Observer and infinity looks like this + + + align:start position:0% +Observer and infinity looks like this +object never fall into the black + + align:start position:0% +object never fall into the black + + + align:start position:0% +object never fall into the black +hole it just Frozen at the + + align:start position:0% +hole it just Frozen at the + + + align:start position:0% +hole it just Frozen at the +Horizon so and the and + + align:start position:0% +Horizon so and the and + + + align:start position:0% +Horizon so and the and +the another remark is that + + align:start position:0% +the another remark is that + + + align:start position:0% +the another remark is that +once + + align:start position:0% +once + + + align:start position:0% +once +inside the horizon + + align:start position:0% + + + + align:start position:0% + +that means when R BEC smaller than + + align:start position:0% + + + + align:start position:0% + +RS The + + align:start position:0% + + + + align:start position:0% + +Traveler + + align:start position:0% +Traveler + + + align:start position:0% +Traveler +canot send signals + + align:start position:0% + + + + align:start position:0% + +out + + align:start position:0% +out + + + align:start position:0% +out +signals to outs side + + align:start position:0% + + + + align:start position:0% + +no can + + align:start position:0% +no can + + + align:start position:0% +no can +he + + align:start position:0% + + + + align:start position:0% + +escape okay so that's why this is called + + align:start position:0% +escape okay so that's why this is called + + + align:start position:0% +escape okay so that's why this is called +even Horizon so we will see this uh uh + + align:start position:0% +even Horizon so we will see this uh uh + + + align:start position:0% +even Horizon so we will see this uh uh +slightly + + align:start position:0% +slightly + + + align:start position:0% +slightly +later in next neure we will see this + + align:start position:0% +later in next neure we will see this + + + align:start position:0% +later in next neure we will see this +explicitly + + align:start position:0% +explicitly + + + align:start position:0% +explicitly +um so + + align:start position:0% +um so + + + align:start position:0% +um so +finally there two important geometric + + align:start position:0% +finally there two important geometric + + + align:start position:0% +finally there two important geometric +quantities associated with a + + align:start position:0% +quantities associated with a + + + align:start position:0% +quantities associated with a +horizon two + + align:start position:0% + + + + align:start position:0% + +important + + align:start position:0% + + + + align:start position:0% + +geometric + + align:start position:0% +geometric + + + align:start position:0% +geometric +okay so the first one + + align:start position:0% + + + + align:start position:0% + +it's the area of the spatial section so + + align:start position:0% +it's the area of the spatial section so + + + align:start position:0% +it's the area of the spatial section so +suppose so let's consider we are at IAL + + align:start position:0% +suppose so let's consider we are at IAL + + + align:start position:0% +suppose so let's consider we are at IAL +to + + align:start position:0% +to + + + align:start position:0% +to +RS and then and here you just set this + + align:start position:0% +RS and then and here you just set this + + + align:start position:0% +RS and then and here you just set this +IAL to r s and then this is a two + + align:start position:0% +IAL to r s and then this is a two + + + align:start position:0% +IAL to r s and then this is a two +dimensional sphere okay so this two + + align:start position:0% +dimensional sphere okay so this two + + + align:start position:0% +dimensional sphere okay so this two +dimensional sphere corresponding to a + + align:start position:0% +dimensional sphere corresponding to a + + + align:start position:0% +dimensional sphere corresponding to a +spatial section say of the + + align:start position:0% +spatial section say of the + + + align:start position:0% +spatial section say of the +Horizon so um so + + align:start position:0% +Horizon so um so + + + align:start position:0% +Horizon so um so +first is this is the + + align:start position:0% +first is this is the + + + align:start position:0% +first is this is the +a is this + + align:start position:0% + + + + align:start position:0% + +area of a spatial + + align:start position:0% + + + + align:start position:0% + +section + + align:start position:0% +section + + + align:start position:0% +section +okay so so you can just say let's look + + align:start position:0% +okay so so you can just say let's look + + + align:start position:0% +okay so so you can just say let's look +at the area of this + + align:start position:0% +at the area of this + + + align:start position:0% +at the area of this +part um with the r equal to the Horizon + + align:start position:0% +part um with the r equal to the Horizon + + + align:start position:0% +part um with the r equal to the Horizon +radius so so this just give you a equal + + align:start position:0% +radius so so this just give you a equal + + + align:start position:0% +radius so so this just give you a equal +to ah equal to 4 pi r + + align:start position:0% +to ah equal to 4 pi r + + + align:start position:0% +to ah equal to 4 pi r +s² and this + + align:start position:0% +s² and this + + + align:start position:0% +s² and this +RS is 2 + + align:start position:0% +RS is 2 + + + align:start position:0% +RS is 2 +GM so this + + align:start position:0% +GM so this + + + align:start position:0% +GM so this +become 16 + + align:start position:0% +become 16 + + + align:start position:0% +become 16 +Pi GM + + align:start position:0% +Pi GM + + + align:start position:0% +Pi GM +squ Square okay so this is one of the + + align:start position:0% +squ Square okay so this is one of the + + + align:start position:0% +squ Square okay so this is one of the +key quantities of a black Horizon is it + + align:start position:0% +key quantities of a black Horizon is it + + + align:start position:0% +key quantities of a black Horizon is it +is what we call Horizon area + + align:start position:0% +is what we call Horizon area + + + align:start position:0% +is what we call Horizon area +okay let we call this Horizon area + + align:start position:0% + + + + align:start position:0% + +and the + + align:start position:0% +and the + + + align:start position:0% +and the +B is called the surface + + align:start position:0% + + + + align:start position:0% + +gravity is called surface + + align:start position:0% +gravity is called surface + + + align:start position:0% +gravity is called surface +gravity so the surface gravity is + + align:start position:0% +gravity so the surface gravity is + + + align:start position:0% +gravity so the surface gravity is +defined by the + + align:start position:0% + + + + align:start position:0% + +acceleration of a stationary Observer + + align:start position:0% + + + + align:start position:0% + +and the + + align:start position:0% + + + + align:start position:0% + +Horizon has + + align:start position:0% + + + + align:start position:0% + +measured at + + align:start position:0% + + + + align:start position:0% + +Infinity okay at Infinity means that the + + align:start position:0% +Infinity okay at Infinity means that the + + + align:start position:0% +Infinity okay at Infinity means that the +yeah spatial + + align:start position:0% +yeah spatial + + + align:start position:0% +yeah spatial +Infinity so so you can uh if you're not + + align:start position:0% +Infinity so so you can uh if you're not + + + align:start position:0% +Infinity so so you can uh if you're not +familiar with the this concept of + + align:start position:0% +familiar with the this concept of + + + align:start position:0% +familiar with the this concept of +surface + + align:start position:0% +surface + + + align:start position:0% +surface +gravity you can find it in standard + + align:start position:0% +gravity you can find it in standard + + + align:start position:0% +gravity you can find it in standard +Textbooks For + + align:start position:0% + + + + align:start position:0% + +example the + + align:start position:0% +example the + + + align:start position:0% +example the +W say page + + align:start position:0% +W say page + + + align:start position:0% +W say page +158 and + + align:start position:0% +158 and + + + align:start position:0% +158 and +also + + align:start position:0% +also + + + align:start position:0% +also +section five okay let's try to check it + + align:start position:0% + + + + align:start position:0% + +there so say suppose you have a black + + align:start position:0% +there so say suppose you have a black + + + align:start position:0% +there so say suppose you have a black +hole + + align:start position:0% + + + + align:start position:0% + +say this is a SWAT of + + align:start position:0% +say this is a SWAT of + + + align:start position:0% +say this is a SWAT of +radius of course since want to fall into + + align:start position:0% +radius of course since want to fall into + + + align:start position:0% +radius of course since want to fall into +the black hole so if you want to + + align:start position:0% +the black hole so if you want to + + + align:start position:0% +the black hole so if you want to +remain at a fixed location outside the + + align:start position:0% +remain at a fixed location outside the + + + align:start position:0% +remain at a fixed location outside the +black Co then you really have to + + align:start position:0% +black Co then you really have to + + + align:start position:0% +black Co then you really have to +accelerate okay you have to file some + + align:start position:0% +accelerate okay you have to file some + + + align:start position:0% +accelerate okay you have to file some +engine to keep yourself to stay there + + align:start position:0% +engine to keep yourself to stay there + + + align:start position:0% +engine to keep yourself to stay there +and you can yeah you can calculate what + + align:start position:0% +and you can yeah you can calculate what + + + align:start position:0% +and you can yeah you can calculate what +is acceleration you need to be able to + + align:start position:0% +is acceleration you need to be able to + + + align:start position:0% +is acceleration you need to be able to +stay here still okay + + align:start position:0% +stay here still okay + + + align:start position:0% +stay here still okay +and once you are closer and closer to + + align:start position:0% +and once you are closer and closer to + + + align:start position:0% +and once you are closer and closer to +the Horizon that acceleration become + + align:start position:0% +the Horizon that acceleration become + + + align:start position:0% +the Horizon that acceleration become +bigger and bigger eventually become + + align:start position:0% +bigger and bigger eventually become + + + align:start position:0% +bigger and bigger eventually become +Infinity when you approach The + + align:start position:0% +Infinity when you approach The + + + align:start position:0% +Infinity when you approach The +Horizon but because of this red shift + + align:start position:0% +Horizon but because of this red shift + + + align:start position:0% +Horizon but because of this red shift +effect okay because of this red shift + + align:start position:0% +effect okay because of this red shift + + + align:start position:0% +effect okay because of this red shift +effect when this acceleration is viewed + + align:start position:0% +effect when this acceleration is viewed + + + align:start position:0% +effect when this acceleration is viewed +from the + + align:start position:0% +from the + + + align:start position:0% +from the +units for observe and infinite and + + align:start position:0% +units for observe and infinite and + + + align:start position:0% +units for observe and infinite and +infinity then you have Infinity divide + + align:start position:0% +infinity then you have Infinity divide + + + align:start position:0% +infinity then you have Infinity divide +by Infinity then tends out to be + + align:start position:0% +by Infinity then tends out to be + + + align:start position:0% +by Infinity then tends out to be +finite and + + align:start position:0% +finite and + + + align:start position:0% +finite and +and this is called surface gravity is + + align:start position:0% +and this is called surface gravity is + + + align:start position:0% +and this is called surface gravity is +normally called + + align:start position:0% +normally called + + + align:start position:0% +normally called +Kappa normally called Kappa and this is + + align:start position:0% +Kappa normally called Kappa and this is + + + align:start position:0% +Kappa normally called Kappa and this is +one of basic quantities basic geometric + + align:start position:0% +one of basic quantities basic geometric + + + align:start position:0% +one of basic quantities basic geometric +quantity of the Horizon so so we're not + + align:start position:0% +quantity of the Horizon so so we're not + + + align:start position:0% +quantity of the Horizon so so we're not +derive it here I don't have + + align:start position:0% +derive it here I don't have + + + align:start position:0% +derive it here I don't have +time and if you want to see it uh see + + align:start position:0% +time and if you want to see it uh see + + + align:start position:0% +time and if you want to see it uh see +this WS book so you can calculate that + + align:start position:0% +this WS book so you can calculate that + + + align:start position:0% +this WS book so you can calculate that +this is just given by + + align:start position:0% + + + + align:start position:0% + +one2 the derivative of this function + + align:start position:0% +one2 the derivative of this function + + + align:start position:0% +one2 the derivative of this function +f you validated at the Horizon uh + + align:start position:0% +f you validated at the Horizon uh + + + align:start position:0% +f you validated at the Horizon uh +invited at the Horizon location okay so + + align:start position:0% +invited at the Horizon location okay so + + + align:start position:0% +invited at the Horizon location okay so +f is equal to zero at the Horizon but F + + align:start position:0% +f is equal to zero at the Horizon but F + + + align:start position:0% +f is equal to zero at the Horizon but F +Prime is not okay so so you can easily + + align:start position:0% +Prime is not okay so so you can easily + + + align:start position:0% +Prime is not okay so so you can easily +calculate so this is 1 over 2 + + align:start position:0% +calculate so this is 1 over 2 + + + align:start position:0% +calculate so this is 1 over 2 +RS from + + align:start position:0% +RS from + + + align:start position:0% +RS from +here and uh is equal to 1 over 4 g + + align:start position:0% +here and uh is equal to 1 over 4 g + + + align:start position:0% +here and uh is equal to 1 over 4 g +m okay this is another very important + + align:start position:0% +m okay this is another very important + + + align:start position:0% +m okay this is another very important +quantity for the for the black ho + + align:start position:0% +quantity for the for the black ho + + + align:start position:0% +quantity for the for the black ho +actually I think right now it's + + align:start position:0% +actually I think right now it's + + + align:start position:0% +actually I think right now it's +a good place to + + align:start position:0% +a good place to + + + align:start position:0% +a good place to +stop + + align:start position:0% +stop + + + align:start position:0% +stop +um okay so let's stop here for today and + + align:start position:0% +um okay so let's stop here for today and + + + align:start position:0% +um okay so let's stop here for today and +next time we will describe then we will + + align:start position:0% +next time we will describe then we will + + + align:start position:0% +next time we will describe then we will +from here we will discuss the Cal + + align:start position:0% +from here we will discuss the Cal + + + align:start position:0% +from here we will discuss the Cal +structure of the black hole and then you + + align:start position:0% +structure of the black hole and then you + + + align:start position:0% +structure of the black hole and then you +will see uh explicitely some of those + + align:start position:0% +will see uh explicitely some of those + + + align:start position:0% +will see uh explicitely some of those +statement if you if you have not seen + + align:start position:0% +statement if you if you have not seen + + + align:start position:0% +statement if you if you have not seen +them before \ No newline at end of file diff --git a/X86s94ylybQ.txt b/X86s94ylybQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..123d83d65b187879854a8689e8bb6c7d4c5ac836 --- /dev/null +++ b/X86s94ylybQ.txt @@ -0,0 +1,7779 @@ +align:start position:0% + +sorry okay what + + align:start position:0% +sorry okay what + + + align:start position:0% +sorry okay what +now all right so before I begin I just + + align:start position:0% +now all right so before I begin I just + + + align:start position:0% +now all right so before I begin I just +want to say I want to keep this pretty + + align:start position:0% +want to say I want to keep this pretty + + + align:start position:0% +want to say I want to keep this pretty +informal you know so feel free to jump + + align:start position:0% +informal you know so feel free to jump + + + align:start position:0% +informal you know so feel free to jump +in if you have comments questions if you + + align:start position:0% +in if you have comments questions if you + + + align:start position:0% +in if you have comments questions if you +disagree with me you know which + + align:start position:0% +disagree with me you know which + + + align:start position:0% +disagree with me you know which +hopefully you will you know so okay so + + align:start position:0% +hopefully you will you know so okay so + + + align:start position:0% +hopefully you will you know so okay so +I'm the first presentation here and I + + align:start position:0% +I'm the first presentation here and I + + + align:start position:0% +I'm the first presentation here and I +kind of like being the first because + + align:start position:0% +kind of like being the first because + + + align:start position:0% +kind of like being the first because +we're just getting introduced to the + + align:start position:0% +we're just getting introduced to the + + + align:start position:0% +we're just getting introduced to the +class so I have a chance to kind of say + + align:start position:0% +class so I have a chance to kind of say + + + align:start position:0% +class so I have a chance to kind of say +my own opinions my own viewpoints on why + + align:start position:0% +my own opinions my own viewpoints on why + + + align:start position:0% +my own opinions my own viewpoints on why +we study film why we're studying + + align:start position:0% +we study film why we're studying + + + align:start position:0% +we study film why we're studying +philosophy of film um and so we've all + + align:start position:0% +philosophy of film um and so we've all + + + align:start position:0% +philosophy of film um and so we've all +done the reading you know so I kind of + + align:start position:0% +done the reading you know so I kind of + + + align:start position:0% +done the reading you know so I kind of +want to present my own views my own + + align:start position:0% +want to present my own views my own + + + align:start position:0% +want to present my own views my own +reactions to the reading you know I + + align:start position:0% +reactions to the reading you know I + + + align:start position:0% +reactions to the reading you know I +agree with a lot of it disagree with + + align:start position:0% +agree with a lot of it disagree with + + + align:start position:0% +agree with a lot of it disagree with +some of it I understand hopefully most + + align:start position:0% +some of it I understand hopefully most + + + align:start position:0% +some of it I understand hopefully most +of it and I'm sure I misunderstood some + + align:start position:0% +of it and I'm sure I misunderstood some + + + align:start position:0% +of it and I'm sure I misunderstood some +of it but I mean it definitely brought + + align:start position:0% +of it but I mean it definitely brought + + + align:start position:0% +of it but I mean it definitely brought +up a lot of questions in my mind and + + align:start position:0% +up a lot of questions in my mind and + + + align:start position:0% +up a lot of questions in my mind and +hopefully my my talk will bring up some + + align:start position:0% +hopefully my my talk will bring up some + + + align:start position:0% +hopefully my my talk will bring up some +more questions that we'll go over um + + align:start position:0% +more questions that we'll go over um + + + align:start position:0% +more questions that we'll go over um +through the rest of the term because I + + align:start position:0% +through the rest of the term because I + + + align:start position:0% +through the rest of the term because I +can't I can't possibly answer all the + + align:start position:0% +can't I can't possibly answer all the + + + align:start position:0% +can't I can't possibly answer all the +questions that came into my head let me + + align:start position:0% +questions that came into my head let me + + + align:start position:0% +questions that came into my head let me +interrupt briefly um if you have any + + align:start position:0% +interrupt briefly um if you have any + + + align:start position:0% +interrupt briefly um if you have any +ideas about the movie we watched last + + align:start position:0% +ideas about the movie we watched last + + + align:start position:0% +ideas about the movie we watched last +time Beauty and the Beast yeah I have + + align:start position:0% +time Beauty and the Beast yeah I have + + + align:start position:0% +time Beauty and the Beast yeah I have +some ideas on that and also feel free to + + align:start position:0% +some ideas on that and also feel free to + + + align:start position:0% +some ideas on that and also feel free to +bring that in okay um so one one of the + + align:start position:0% +bring that in okay um so one one of the + + + align:start position:0% +bring that in okay um so one one of the +major questions that I have that's kind + + align:start position:0% +major questions that I have that's kind + + + align:start position:0% +major questions that I have that's kind +of a recurring theme in my life is why + + align:start position:0% +of a recurring theme in my life is why + + + align:start position:0% +of a recurring theme in my life is why +study film because I've been studying + + align:start position:0% +study film because I've been studying + + + align:start position:0% +study film because I've been studying +film all through MIT you know and + + align:start position:0% +film all through MIT you know and + + + align:start position:0% +film all through MIT you know and +obviously all of us have chosen to study + + align:start position:0% +obviously all of us have chosen to study + + + align:start position:0% +obviously all of us have chosen to study +film too and I didn't really know why + + align:start position:0% +film too and I didn't really know why + + + align:start position:0% +film too and I didn't really know why +you know um it's not like my parents + + align:start position:0% +you know um it's not like my parents + + + align:start position:0% +you know um it's not like my parents +made me or I need to do it to graduate + + align:start position:0% +made me or I need to do it to graduate + + + align:start position:0% +made me or I need to do it to graduate +or something you know it's just + + align:start position:0% +or something you know it's just + + + align:start position:0% +or something you know it's just +something that I choose to do and it's a + + align:start position:0% +something that I choose to do and it's a + + + align:start position:0% +something that I choose to do and it's a +it's a very personal question for all of + + align:start position:0% +it's a very personal question for all of + + + align:start position:0% +it's a very personal question for all of +us and we probably each have our own + + align:start position:0% +us and we probably each have our own + + + align:start position:0% +us and we probably each have our own +answers and I'm going to talk about why + + align:start position:0% +answers and I'm going to talk about why + + + align:start position:0% +answers and I'm going to talk about why +I choose to study film because I thought + + align:start position:0% +I choose to study film because I thought + + + align:start position:0% +I choose to study film because I thought +about it a lot and to answer that you + + align:start position:0% +about it a lot and to answer that you + + + align:start position:0% +about it a lot and to answer that you +know I need to tell you a little bit + + align:start position:0% +know I need to tell you a little bit + + + align:start position:0% +know I need to tell you a little bit +about my personal life and I'll get to + + align:start position:0% +about my personal life and I'll get to + + + align:start position:0% +about my personal life and I'll get to +that but first uh some definitions like + + align:start position:0% +that but first uh some definitions like + + + align:start position:0% +that but first uh some definitions like +uh realism and formalism were mentioned + + align:start position:0% +uh realism and formalism were mentioned + + + align:start position:0% +uh realism and formalism were mentioned +in the text and at MIT I've taken I + + align:start position:0% +in the text and at MIT I've taken I + + + align:start position:0% +in the text and at MIT I've taken I +don't know like three or four film + + align:start position:0% +don't know like three or four film + + + align:start position:0% +don't know like three or four film +classes now and in each of those classes + + align:start position:0% +classes now and in each of those classes + + + align:start position:0% +classes now and in each of those classes +we generally use a combination of those + + align:start position:0% +we generally use a combination of those + + + align:start position:0% +we generally use a combination of those +two techniques and honestly I think + + align:start position:0% +two techniques and honestly I think + + + align:start position:0% +two techniques and honestly I think +they're pretty hard to Define they seem + + align:start position:0% +they're pretty hard to Define they seem + + + align:start position:0% +they're pretty hard to Define they seem +to be um the opposite ends of a spectrum + + align:start position:0% +to be um the opposite ends of a spectrum + + + align:start position:0% +to be um the opposite ends of a spectrum +in which you can analyze film and so + + align:start position:0% +in which you can analyze film and so + + + align:start position:0% +in which you can analyze film and so +there's two different ways you can look + + align:start position:0% +there's two different ways you can look + + + align:start position:0% +there's two different ways you can look +at each aspect of film so that that + + align:start position:0% +at each aspect of film so that that + + + align:start position:0% +at each aspect of film so that that +means U for example story editing um uh + + align:start position:0% +means U for example story editing um uh + + + align:start position:0% +means U for example story editing um uh +costumes everything you know there's two + + align:start position:0% +costumes everything you know there's two + + + align:start position:0% +costumes everything you know there's two +different ways you can look at it so + + align:start position:0% +different ways you can look at it so + + + align:start position:0% +different ways you can look at it so +it's hard to Define since they overlaps + + align:start position:0% +it's hard to Define since they overlaps + + + align:start position:0% +it's hard to Define since they overlaps +so much but still I try to Define them + + align:start position:0% +so much but still I try to Define them + + + align:start position:0% +so much but still I try to Define them +you know because I want to have a clear + + align:start position:0% +you know because I want to have a clear + + + align:start position:0% +you know because I want to have a clear +picture of what exactly they mean so in + + align:start position:0% +picture of what exactly they mean so in + + + align:start position:0% +picture of what exactly they mean so in +realism it seems like what that means is + + align:start position:0% +realism it seems like what that means is + + + align:start position:0% +realism it seems like what that means is +the film is capturing an aspect of real + + align:start position:0% +the film is capturing an aspect of real + + + align:start position:0% +the film is capturing an aspect of real +life and that's what makes it powerful + + align:start position:0% +life and that's what makes it powerful + + + align:start position:0% +life and that's what makes it powerful +basically the um I'm sure you've all + + align:start position:0% +basically the um I'm sure you've all + + + align:start position:0% +basically the um I'm sure you've all +heard that art imitates life um so + + align:start position:0% +heard that art imitates life um so + + + align:start position:0% +heard that art imitates life um so +something about film is reflecting the + + align:start position:0% +something about film is reflecting the + + + align:start position:0% +something about film is reflecting the +actual world and maybe maybe even more + + align:start position:0% +actual world and maybe maybe even more + + + align:start position:0% +actual world and maybe maybe even more +than reflecting it's representing the + + align:start position:0% +than reflecting it's representing the + + + align:start position:0% +than reflecting it's representing the +world or being the world now let's talk + + align:start position:0% +world or being the world now let's talk + + + align:start position:0% +world or being the world now let's talk +about formalism um to me that means that + + align:start position:0% +about formalism um to me that means that + + + align:start position:0% +about formalism um to me that means that +you're using the power of film you're + + align:start position:0% +you're using the power of film you're + + + align:start position:0% +you're using the power of film you're +using technology to extend real life + + align:start position:0% +using technology to extend real life + + + align:start position:0% +using technology to extend real life +um so for example with editing of course + + align:start position:0% +um so for example with editing of course + + + align:start position:0% +um so for example with editing of course +a realist would have something different + + align:start position:0% +a realist would have something different + + + align:start position:0% +a realist would have something different +to say about this but but for editing + + align:start position:0% +to say about this but but for editing + + + align:start position:0% +to say about this but but for editing +you're you're able to change um + + align:start position:0% +you're you're able to change um + + + align:start position:0% +you're you're able to change um +temporality you know you can you can + + align:start position:0% +temporality you know you can you can + + + align:start position:0% +temporality you know you can you can +rearrange time you can rearrange space + + align:start position:0% +rearrange time you can rearrange space + + + align:start position:0% +rearrange time you can rearrange space +and that's power part of the power of + + align:start position:0% +and that's power part of the power of + + + align:start position:0% +and that's power part of the power of +film in which you in which you can + + align:start position:0% +film in which you in which you can + + + align:start position:0% +film in which you in which you can +change reality and give people something + + align:start position:0% +change reality and give people something + + + align:start position:0% +change reality and give people something +more um okay so as I said we analyzed + + align:start position:0% +more um okay so as I said we analyzed + + + align:start position:0% +more um okay so as I said we analyzed +film in my previous classes using + + align:start position:0% +film in my previous classes using + + + align:start position:0% +film in my previous classes using +combination of the two things because + + align:start position:0% +combination of the two things because + + + align:start position:0% +combination of the two things because +you want see how it relates to the real + + align:start position:0% +you want see how it relates to the real + + + align:start position:0% +you want see how it relates to the real +world but you also want to see what + + align:start position:0% +world but you also want to see what + + + align:start position:0% +world but you also want to see what +directors can do to harness the power of + + align:start position:0% +directors can do to harness the power of + + + align:start position:0% +directors can do to harness the power of +the media of the medium um so which way + + align:start position:0% +the media of the medium um so which way + + + align:start position:0% +the media of the medium um so which way +is the best I really don't know but I + + align:start position:0% +is the best I really don't know but I + + + align:start position:0% +is the best I really don't know but I +think a combination of the two is useful + + align:start position:0% +think a combination of the two is useful + + + align:start position:0% +think a combination of the two is useful +because at least then you can see what + + align:start position:0% +because at least then you can see what + + + align:start position:0% +because at least then you can see what +you can try to get the advantages of + + align:start position:0% +you can try to get the advantages of + + + align:start position:0% +you can try to get the advantages of +both + + align:start position:0% +both + + + align:start position:0% +both +approaches okay + + align:start position:0% +approaches okay + + + align:start position:0% +approaches okay +so I want to I want to say a quote from + + align:start position:0% +so I want to I want to say a quote from + + + align:start position:0% +so I want to I want to say a quote from +a movie actually um there's a quote from + + align:start position:0% +a movie actually um there's a quote from + + + align:start position:0% +a movie actually um there's a quote from +the player which was I think it came out + + align:start position:0% +the player which was I think it came out + + + align:start position:0% +the player which was I think it came out +in the 80s directed by Alman and the + + align:start position:0% +in the 80s directed by Alman and the + + + align:start position:0% +in the 80s directed by Alman and the +quote I want to say is movies are art + + align:start position:0% +quote I want to say is movies are art + + + align:start position:0% +quote I want to say is movies are art +now more than ever and that's a quote by + + align:start position:0% +now more than ever and that's a quote by + + + align:start position:0% +now more than ever and that's a quote by +the main character and um so to me + + align:start position:0% +the main character and um so to me + + + align:start position:0% +the main character and um so to me +that's one of the central reasons why we + + align:start position:0% +that's one of the central reasons why we + + + align:start position:0% +that's one of the central reasons why we +study film because we think that it's + + align:start position:0% +study film because we think that it's + + + align:start position:0% +study film because we think that it's +art and that's great ex how do you + + align:start position:0% +art and that's great ex how do you + + + align:start position:0% +art and that's great ex how do you +define art because that's really hard to + + align:start position:0% +define art because that's really hard to + + + align:start position:0% +define art because that's really hard to +Define too and in fact it's an ongoing + + align:start position:0% +Define too and in fact it's an ongoing + + + align:start position:0% +Define too and in fact it's an ongoing +battle with modern art you know um a lot + + align:start position:0% +battle with modern art you know um a lot + + + align:start position:0% +battle with modern art you know um a lot +of people go to an art museum and see a + + align:start position:0% +of people go to an art museum and see a + + + align:start position:0% +of people go to an art museum and see a +piece of mod and say oh that's not art + + align:start position:0% +piece of mod and say oh that's not art + + + align:start position:0% +piece of mod and say oh that's not art +well why you know it's really hard to + + align:start position:0% +well why you know it's really hard to + + + align:start position:0% +well why you know it's really hard to +Define um so let me tell you a little + + align:start position:0% +Define um so let me tell you a little + + + align:start position:0% +Define um so let me tell you a little +bit about my own personal background I + + align:start position:0% +bit about my own personal background I + + + align:start position:0% +bit about my own personal background I +started playing piano and violin when I + + align:start position:0% +started playing piano and violin when I + + + align:start position:0% +started playing piano and violin when I +was four years old so and all the way up + + align:start position:0% +was four years old so and all the way up + + + align:start position:0% +was four years old so and all the way up +to MIT when I became too busy with + + align:start position:0% +to MIT when I became too busy with + + + align:start position:0% +to MIT when I became too busy with +problem sets to to really play much + + align:start position:0% +problem sets to to really play much + + + align:start position:0% +problem sets to to really play much +anymore but um so To Me music was my + + align:start position:0% +anymore but um so To Me music was my + + + align:start position:0% +anymore but um so To Me music was my +first my first art you know my first + + align:start position:0% +first my first art you know my first + + + align:start position:0% +first my first art you know my first +love of art came from music now if you + + align:start position:0% +love of art came from music now if you + + + align:start position:0% +love of art came from music now if you +look at music you can't really use + + align:start position:0% +look at music you can't really use + + + align:start position:0% +look at music you can't really use +realism and formalism to analyze music + + align:start position:0% +realism and formalism to analyze music + + + align:start position:0% +realism and formalism to analyze music +because + + align:start position:0% + + + + align:start position:0% + +well go ahead you want to say something + + align:start position:0% +well go ahead you want to say something + + + align:start position:0% +well go ahead you want to say something +well you can talk about leaving aside + + align:start position:0% +well you can talk about leaving aside + + + align:start position:0% +well you can talk about leaving aside +representational music which is + + align:start position:0% +representational music which is + + + align:start position:0% +representational music which is +obviously going to be patterned upon + + align:start position:0% +obviously going to be patterned upon + + + align:start position:0% +obviously going to be patterned upon +some reality right yeah um a tone poem + + align:start position:0% +some reality right yeah um a tone poem + + + align:start position:0% +some reality right yeah um a tone poem +by Richard Strauss wants you + + align:start position:0% +by Richard Strauss wants you + + + align:start position:0% +by Richard Strauss wants you +to hear or imagine sonically what um the + + align:start position:0% +to hear or imagine sonically what um the + + + align:start position:0% +to hear or imagine sonically what um the +Sheep are in + + align:start position:0% +Sheep are in + + + align:start position:0% +Sheep are in +donot or what the adventures are of Don + + align:start position:0% +donot or what the adventures are of Don + + + align:start position:0% +donot or what the adventures are of Don +Juan that's the nature of + + align:start position:0% +Juan that's the nature of + + + align:start position:0% +Juan that's the nature of +programmatic tone poems of that sort now + + align:start position:0% +programmatic tone poems of that sort now + + + align:start position:0% +programmatic tone poems of that sort now +that that would be a realistic effect uh + + align:start position:0% +that that would be a realistic effect uh + + + align:start position:0% +that that would be a realistic effect uh +but over and above that uh almost + + align:start position:0% +but over and above that uh almost + + + align:start position:0% +but over and above that uh almost +everybody recognizes that music is + + align:start position:0% +everybody recognizes that music is + + + align:start position:0% +everybody recognizes that music is +important for what it expresses + + align:start position:0% +important for what it expresses + + + align:start position:0% +important for what it expresses +shuminsky said somewhere music doesn't + + align:start position:0% +shuminsky said somewhere music doesn't + + + align:start position:0% +shuminsky said somewhere music doesn't +Express anything it expresses + + align:start position:0% +Express anything it expresses + + + align:start position:0% +Express anything it expresses +itself which is a way of denying that it + + align:start position:0% +itself which is a way of denying that it + + + align:start position:0% +itself which is a way of denying that it +expresses anything in the composer or in + + align:start position:0% +expresses anything in the composer or in + + + align:start position:0% +expresses anything in the composer or in +the world feelings + + align:start position:0% +the world feelings + + + align:start position:0% +the world feelings +or an a theory of the world an attitude + + align:start position:0% +or an a theory of the world an attitude + + + align:start position:0% +or an a theory of the world an attitude +toward the world it's not expressive at + + align:start position:0% +toward the world it's not expressive at + + + align:start position:0% +toward the world it's not expressive at +all um the OD what's amusing however is + + align:start position:0% +all um the OD what's amusing however is + + + align:start position:0% +all um the OD what's amusing however is +that Stravinsky's music it is often very + + align:start position:0% +that Stravinsky's music it is often very + + + align:start position:0% +that Stravinsky's music it is often very +very expressive and he went through + + align:start position:0% +very expressive and he went through + + + align:start position:0% +very expressive and he went through +Romantic Period and then uh Classical + + align:start position:0% +Romantic Period and then uh Classical + + + align:start position:0% +Romantic Period and then uh Classical +period and in The Classical period + + align:start position:0% +period and in The Classical period + + + align:start position:0% +period and in The Classical period +there's a great emphasis on technique + + align:start position:0% +there's a great emphasis on technique + + + align:start position:0% +there's a great emphasis on technique +but it still it nevertheless remains + + align:start position:0% +but it still it nevertheless remains + + + align:start position:0% +but it still it nevertheless remains +expressive the uh + + align:start position:0% +expressive the uh + + + align:start position:0% +expressive the uh +formalist view would emphasize music as + + align:start position:0% +formalist view would emphasize music as + + + align:start position:0% +formalist view would emphasize music as +a series of techniques as requiring a + + align:start position:0% +a series of techniques as requiring a + + + align:start position:0% +a series of techniques as requiring a +knowledge of the scales of of different + + align:start position:0% +knowledge of the scales of of different + + + align:start position:0% +knowledge of the scales of of different +ways of manipulating the notes of + + align:start position:0% +ways of manipulating the notes of + + + align:start position:0% +ways of manipulating the notes of +different forms musical forms and that's + + align:start position:0% +different forms musical forms and that's + + + align:start position:0% +different forms musical forms and that's +what's usually taught in music classes + + align:start position:0% +what's usually taught in music classes + + + align:start position:0% +what's usually taught in music classes +introductory ones because they're afraid + + align:start position:0% +introductory ones because they're afraid + + + align:start position:0% +introductory ones because they're afraid +the students are going to have Daydreams + + align:start position:0% +the students are going to have Daydreams + + + align:start position:0% +the students are going to have Daydreams +about um some romantic moment or or you + + align:start position:0% +about um some romantic moment or or you + + + align:start position:0% +about um some romantic moment or or you +know something in Schubert which is very + + align:start position:0% +know something in Schubert which is very + + + align:start position:0% +know something in Schubert which is very +sad or very you know something like that + + align:start position:0% +sad or very you know something like that + + + align:start position:0% +sad or very you know something like that +and never hear the music so that there + + align:start position:0% +and never hear the music so that there + + + align:start position:0% +and never hear the music so that there +too you get the same problem about the + + align:start position:0% +too you get the same problem about the + + + align:start position:0% +too you get the same problem about the +formalistic element and the realistic + + align:start position:0% +formalistic element and the realistic + + + align:start position:0% +formalistic element and the realistic +one and the difficulty for the theorist + + align:start position:0% +one and the difficulty for the theorist + + + align:start position:0% +one and the difficulty for the theorist +or the philosopher is to make sense out + + align:start position:0% +or the philosopher is to make sense out + + + align:start position:0% +or the philosopher is to make sense out +of what these different Alternatives + + align:start position:0% +of what these different Alternatives + + + align:start position:0% +of what these different Alternatives +might be so it's not entirely different + + align:start position:0% +might be so it's not entirely different + + + align:start position:0% +might be so it's not entirely different +from film okay but I don't mean I didn't + + align:start position:0% +from film okay but I don't mean I didn't + + + align:start position:0% +from film okay but I don't mean I didn't +mean to interrupt you that long oh no + + align:start position:0% +mean to interrupt you that long oh no + + + align:start position:0% +mean to interrupt you that long oh no +that's okay um so when I was growing up + + align:start position:0% +that's okay um so when I was growing up + + + align:start position:0% +that's okay um so when I was growing up +though of course I didn't approach music + + align:start position:0% +though of course I didn't approach music + + + align:start position:0% +though of course I didn't approach music +with such a with such a philosophy you + + align:start position:0% +with such a with such a philosophy you + + + align:start position:0% +with such a with such a philosophy you +know I was just trying to enjoy it and + + align:start position:0% +know I was just trying to enjoy it and + + + align:start position:0% +know I was just trying to enjoy it and +and try to see how it's an art form and + + align:start position:0% +and try to see how it's an art form and + + + align:start position:0% +and try to see how it's an art form and +one of the things that I noticed is just + + align:start position:0% +one of the things that I noticed is just + + + align:start position:0% +one of the things that I noticed is just +that art I mean music Sorry music is + + align:start position:0% +that art I mean music Sorry music is + + + align:start position:0% +that art I mean music Sorry music is +highly capable of of producing emotion + + align:start position:0% +highly capable of of producing emotion + + + align:start position:0% +highly capable of of producing emotion +in someone you know and that's something + + align:start position:0% +in someone you know and that's something + + + align:start position:0% +in someone you know and that's something +strange you know why should why should + + align:start position:0% +strange you know why should why should + + + align:start position:0% +strange you know why should why should +these noises produce an emotional + + align:start position:0% +these noises produce an emotional + + + align:start position:0% +these noises produce an emotional +response in a human being and that's + + align:start position:0% +response in a human being and that's + + + align:start position:0% +response in a human being and that's +probably never going to be explained but + + align:start position:0% +probably never going to be explained but + + + align:start position:0% +probably never going to be explained but +I mean that's that's one of the reasons + + align:start position:0% +I mean that's that's one of the reasons + + + align:start position:0% +I mean that's that's one of the reasons +to me that it makes it art it it is able + + align:start position:0% +to me that it makes it art it it is able + + + align:start position:0% +to me that it makes it art it it is able +to evolve this emotion and so um I think + + align:start position:0% +to evolve this emotion and so um I think + + + align:start position:0% +to evolve this emotion and so um I think +my personal um definition of art like + + align:start position:0% +my personal um definition of art like + + + align:start position:0% +my personal um definition of art like +what is art to me well I would say that + + align:start position:0% +what is art to me well I would say that + + + align:start position:0% +what is art to me well I would say that +it's something that can either provoke a + + align:start position:0% +it's something that can either provoke a + + + align:start position:0% +it's something that can either provoke a +cognitive or an effective response so + + align:start position:0% +cognitive or an effective response so + + + align:start position:0% +cognitive or an effective response so +what does that mean it either makes me + + align:start position:0% +what does that mean it either makes me + + + align:start position:0% +what does that mean it either makes me +think or it makes me have an emotional + + align:start position:0% +think or it makes me have an emotional + + + align:start position:0% +think or it makes me have an emotional +response to it of which music can do + + align:start position:0% +response to it of which music can do + + + align:start position:0% +response to it of which music can do +both and so to me art is all about the + + align:start position:0% +both and so to me art is all about the + + + align:start position:0% +both and so to me art is all about the +ception you know I don't I don't + + align:start position:0% +ception you know I don't I don't + + + align:start position:0% +ception you know I don't I don't +really um actually let me let me uh save + + align:start position:0% +really um actually let me let me uh save + + + align:start position:0% +really um actually let me let me uh save +that for a little bit later but um so + + align:start position:0% +that for a little bit later but um so + + + align:start position:0% +that for a little bit later but um so +what is it about perception you know why + + align:start position:0% +what is it about perception you know why + + + align:start position:0% +what is it about perception you know why +why would we enjoy something that makes + + align:start position:0% +why would we enjoy something that makes + + + align:start position:0% +why would we enjoy something that makes +us think something that makes us feel + + align:start position:0% +us think something that makes us feel + + + align:start position:0% +us think something that makes us feel +emotions well I think that's just one of + + align:start position:0% +emotions well I think that's just one of + + + align:start position:0% +emotions well I think that's just one of +the basic basic aspects of humanity that + + align:start position:0% +the basic basic aspects of humanity that + + + align:start position:0% +the basic basic aspects of humanity that +we want to learn we want to experience + + align:start position:0% +we want to learn we want to experience + + + align:start position:0% +we want to learn we want to experience +so art makes us learn and it makes us + + align:start position:0% +so art makes us learn and it makes us + + + align:start position:0% +so art makes us learn and it makes us +experience and that satisfies one of our + + align:start position:0% +experience and that satisfies one of our + + + align:start position:0% +experience and that satisfies one of our +basic desires + + align:start position:0% +basic desires + + + align:start position:0% +basic desires +let me interrupt you again one of the + + align:start position:0% +let me interrupt you again one of the + + + align:start position:0% +let me interrupt you again one of the +burdens the main burden of the book + + align:start position:0% +burdens the main burden of the book + + + align:start position:0% +burdens the main burden of the book +which you'll realize when you finish it + + align:start position:0% +which you'll realize when you finish it + + + align:start position:0% +which you'll realize when you finish it +is to say that our way of formulating + + align:start position:0% +is to say that our way of formulating + + + align:start position:0% +is to say that our way of formulating +the problem between the realistic and + + align:start position:0% +the problem between the realistic and + + + align:start position:0% +the problem between the realistic and +the formalistic is itself self deficient + + align:start position:0% +the formalistic is itself self deficient + + + align:start position:0% +the formalistic is itself self deficient +and that's the job of the philosopher to + + align:start position:0% +and that's the job of the philosopher to + + + align:start position:0% +and that's the job of the philosopher to +help us make our ideas clear and my + + align:start position:0% +help us make our ideas clear and my + + + align:start position:0% +help us make our ideas clear and my +suggestion is that the two alternatives + + align:start position:0% +suggestion is that the two alternatives + + + align:start position:0% +suggestion is that the two alternatives +are not really separate it's an + + align:start position:0% +are not really separate it's an + + + align:start position:0% +are not really separate it's an +artificial distinction the way most + + align:start position:0% +artificial distinction the way most + + + align:start position:0% +artificial distinction the way most +philosophical distinctions are and in + + align:start position:0% +philosophical distinctions are and in + + + align:start position:0% +philosophical distinctions are and in +reality the two interpenetrate and so + + align:start position:0% +reality the two interpenetrate and so + + + align:start position:0% +reality the two interpenetrate and so +one has to find a way + + align:start position:0% +one has to find a way + + + align:start position:0% +one has to find a way +of explaining and understanding and + + align:start position:0% +of explaining and understanding and + + + align:start position:0% +of explaining and understanding and +experiencing the + + align:start position:0% +experiencing the + + + align:start position:0% +experiencing the +interpenetration so that it's not just a + + align:start position:0% +interpenetration so that it's not just a + + + align:start position:0% +interpenetration so that it's not just a +question of Music doing both the + + align:start position:0% +question of Music doing both the + + + align:start position:0% +question of Music doing both the +formalistic and the non- formalistic one + + align:start position:0% +formalistic and the non- formalistic one + + + align:start position:0% +formalistic and the non- formalistic one +both uh making sounds and also + + align:start position:0% +both uh making sounds and also + + + align:start position:0% +both uh making sounds and also +expressing emotions but the two are + + align:start position:0% +expressing emotions but the two are + + + align:start position:0% +expressing emotions but the two are +interwoven and then how does one make + + align:start position:0% +interwoven and then how does one make + + + align:start position:0% +interwoven and then how does one make +sense out of the concept of the into W + + align:start position:0% +sense out of the concept of the into W + + + align:start position:0% +sense out of the concept of the into W +woing into weaving and what are + + align:start position:0% +woing into weaving and what are + + + align:start position:0% +woing into weaving and what are +different ways of doing that briefly in + + align:start position:0% +different ways of doing that briefly in + + + align:start position:0% +different ways of doing that briefly in +terms of your two instruments there are + + align:start position:0% +terms of your two instruments there are + + + align:start position:0% +terms of your two instruments there are +pianists and + + align:start position:0% +pianists and + + + align:start position:0% +pianists and +violinists who seem to have a very + + align:start position:0% +violinists who seem to have a very + + + align:start position:0% +violinists who seem to have a very +profound understanding of the music in + + align:start position:0% +profound understanding of the music in + + + align:start position:0% +profound understanding of the music in +terms of the feelings like yudi Manu + + align:start position:0% +terms of the feelings like yudi Manu + + + align:start position:0% +terms of the feelings like yudi Manu +would be a good example um on the other + + align:start position:0% +would be a good example um on the other + + + align:start position:0% +would be a good example um on the other +hand in Violin other hand on the other + + align:start position:0% +hand in Violin other hand on the other + + + align:start position:0% +hand in Violin other hand on the other +hand there are those whose technique is + + align:start position:0% +hand there are those whose technique is + + + align:start position:0% +hand there are those whose technique is +absolutely perfect and they don't seem + + align:start position:0% +absolutely perfect and they don't seem + + + align:start position:0% +absolutely perfect and they don't seem +to express very much they really know + + align:start position:0% +to express very much they really know + + + align:start position:0% +to express very much they really know +how to use the instrument but they don't + + align:start position:0% +how to use the instrument but they don't + + + align:start position:0% +how to use the instrument but they don't +use it with any profound Insight well + + align:start position:0% +use it with any profound Insight well + + + align:start position:0% +use it with any profound Insight well +for me as a listener as observing the + + align:start position:0% +for me as a listener as observing the + + + align:start position:0% +for me as a listener as observing the +situation it tells me something about + + align:start position:0% +situation it tells me something about + + + align:start position:0% +situation it tells me something about +them as people you know I want to say + + align:start position:0% +them as people you know I want to say + + + align:start position:0% +them as people you know I want to say +yudi minu in order to play like that has + + align:start position:0% +yudi minu in order to play like that has + + + align:start position:0% +yudi minu in order to play like that has +not only learned the how how to use the + + align:start position:0% +not only learned the how how to use the + + + align:start position:0% +not only learned the how how to use the +technique but he has developed + + align:start position:0% +technique but he has developed + + + align:start position:0% +technique but he has developed +in his personality and so if one says + + align:start position:0% +in his personality and so if one says + + + align:start position:0% +in his personality and so if one says +about his music it's very spiritual very + + align:start position:0% +about his music it's very spiritual very + + + align:start position:0% +about his music it's very spiritual very +Soulful very filled with a kind of + + align:start position:0% +Soulful very filled with a kind of + + + align:start position:0% +Soulful very filled with a kind of +natural acceptance of the world and of + + align:start position:0% +natural acceptance of the world and of + + + align:start position:0% +natural acceptance of the world and of +other people and that in that sense he's + + align:start position:0% +other people and that in that sense he's + + + align:start position:0% +other people and that in that sense he's +a very beautiful person I've never met + + align:start position:0% +a very beautiful person I've never met + + + align:start position:0% +a very beautiful person I've never met +him but just listening I've I've seen + + align:start position:0% +him but just listening I've I've seen + + + align:start position:0% +him but just listening I've I've seen +him on screen of course but listening to + + align:start position:0% +him on screen of course but listening to + + + align:start position:0% +him on screen of course but listening to +the music I feel like in touch with that + + align:start position:0% +the music I feel like in touch with that + + + align:start position:0% +the music I feel like in touch with that +aspect of his being well that's because + + align:start position:0% +aspect of his being well that's because + + + align:start position:0% +aspect of his being well that's because +of the way in which he integrates the + + align:start position:0% +of the way in which he integrates the + + + align:start position:0% +of the way in which he integrates the +formal and the technical the formal and + + align:start position:0% +formal and the technical the formal and + + + align:start position:0% +formal and the technical the formal and +the realistic and that others um do it + + align:start position:0% +the realistic and that others um do it + + + align:start position:0% +the realistic and that others um do it +in a different way and that tells me + + align:start position:0% +in a different way and that tells me + + + align:start position:0% +in a different way and that tells me +something about them in either event the + + align:start position:0% +something about them in either event the + + + align:start position:0% +something about them in either event the +art is a function of the humanity the + + align:start position:0% +art is a function of the humanity the + + + align:start position:0% +art is a function of the humanity the +total Humanity of the practitioner and + + align:start position:0% +total Humanity of the practitioner and + + + align:start position:0% +total Humanity of the practitioner and +the difficulty is that you can teach + + align:start position:0% +the difficulty is that you can teach + + + align:start position:0% +the difficulty is that you can teach +people scales and exercises you can't + + align:start position:0% +people scales and exercises you can't + + + align:start position:0% +people scales and exercises you can't +teach them how to be human they've got + + align:start position:0% +teach them how to be human they've got + + + align:start position:0% +teach them how to be human they've got +somehow to be lucky enough to grow up in + + align:start position:0% +somehow to be lucky enough to grow up in + + + align:start position:0% +somehow to be lucky enough to grow up in +a world in which it comes out of them + + align:start position:0% +a world in which it comes out of them + + + align:start position:0% +a world in which it comes out of them +maybe they had a suffer or maybe they + + align:start position:0% +maybe they had a suffer or maybe they + + + align:start position:0% +maybe they had a suffer or maybe they +had to have a a loving parent especially + + align:start position:0% +had to have a a loving parent especially + + + align:start position:0% +had to have a a loving parent especially +a loving woman you know uh that I don't + + align:start position:0% +a loving woman you know uh that I don't + + + align:start position:0% +a loving woman you know uh that I don't +mean a loving mother um I haven't done + + align:start position:0% +mean a loving mother um I haven't done + + + align:start position:0% +mean a loving mother um I haven't done +the sociology but um I'll bet one finds + + align:start position:0% +the sociology but um I'll bet one finds + + + align:start position:0% +the sociology but um I'll bet one finds +that a great many of the really + + align:start position:0% +that a great many of the really + + + align:start position:0% +that a great many of the really +outstanding musicians learn music from + + align:start position:0% +outstanding musicians learn music from + + + align:start position:0% +outstanding musicians learn music from +their + + align:start position:0% +their + + + align:start position:0% +their +mothers particularly if they were men I + + align:start position:0% +mothers particularly if they were men I + + + align:start position:0% +mothers particularly if they were men I +don't know what about the girls but the + + align:start position:0% +don't know what about the girls but the + + + align:start position:0% +don't know what about the girls but the +being a little boy sitting at your + + align:start position:0% +being a little boy sitting at your + + + align:start position:0% +being a little boy sitting at your +mother's lap while she's playing the + + align:start position:0% +mother's lap while she's playing the + + + align:start position:0% +mother's lap while she's playing the +piano and teaching you affects them as + + align:start position:0% +piano and teaching you affects them as + + + align:start position:0% +piano and teaching you affects them as +human beings and also uh accelerates + + align:start position:0% +human beings and also uh accelerates + + + align:start position:0% +human beings and also uh accelerates +their ability to become uh proficient + + align:start position:0% +their ability to become uh proficient + + + align:start position:0% +their ability to become uh proficient +technicians in their art form so there + + align:start position:0% +technicians in their art form so there + + + align:start position:0% +technicians in their art form so there +there are all sorts of causes about the + + align:start position:0% +there are all sorts of causes about the + + + align:start position:0% +there are all sorts of causes about the +expressiveness but the two are not going + + align:start position:0% +expressiveness but the two are not going + + + align:start position:0% +expressiveness but the two are not going +to be separable ultimately and that's + + align:start position:0% +to be separable ultimately and that's + + + align:start position:0% +to be separable ultimately and that's +what I tried to argue that was my + + align:start position:0% +what I tried to argue that was my + + + align:start position:0% +what I tried to argue that was my +inspiration when I try to argue uh the + + align:start position:0% +inspiration when I try to argue uh the + + + align:start position:0% +inspiration when I try to argue uh the +um thesis in reality + + align:start position:0% +um thesis in reality + + + align:start position:0% +um thesis in reality +transformed you noticed in the first + + align:start position:0% +transformed you noticed in the first + + + align:start position:0% +transformed you noticed in the first +chapter I set up the positions in terms + + align:start position:0% +chapter I set up the positions in terms + + + align:start position:0% +chapter I set up the positions in terms +of theorists who have maintained that + + align:start position:0% +of theorists who have maintained that + + + align:start position:0% +of theorists who have maintained that +they were realists or formalists and I + + align:start position:0% +they were realists or formalists and I + + + align:start position:0% +they were realists or formalists and I +attack both of them with the idea that + + align:start position:0% +attack both of them with the idea that + + + align:start position:0% +attack both of them with the idea that +what they're saying isn't wrong but + + align:start position:0% +what they're saying isn't wrong but + + + align:start position:0% +what they're saying isn't wrong but +having limited themselves they're + + align:start position:0% +having limited themselves they're + + + align:start position:0% +having limited themselves they're +ignoring something else and then in the + + align:start position:0% +ignoring something else and then in the + + + align:start position:0% +ignoring something else and then in the +last chap I suggest the integration and + + align:start position:0% +last chap I suggest the integration and + + + align:start position:0% +last chap I suggest the integration and +how difficult it is to understand the + + align:start position:0% +how difficult it is to understand the + + + align:start position:0% +how difficult it is to understand the +the second book you of mine you'll be + + align:start position:0% +the second book you of mine you'll be + + + align:start position:0% +the second book you of mine you'll be +reading tries to start from that except + + align:start position:0% +reading tries to start from that except + + + align:start position:0% +reading tries to start from that except +starting with exemplars of cinematic + + align:start position:0% +starting with exemplars of cinematic + + + align:start position:0% +starting with exemplars of cinematic +greatness three great filmmakers none of + + align:start position:0% +greatness three great filmmakers none of + + + align:start position:0% +greatness three great filmmakers none of +whom people would have called + + align:start position:0% +whom people would have called + + + align:start position:0% +whom people would have called +philosophers because they don't come in + + align:start position:0% +philosophers because they don't come in + + + align:start position:0% +philosophers because they don't come in +with thesis like some U European in + + align:start position:0% +with thesis like some U European in + + + align:start position:0% +with thesis like some U European in +particular filmmakers uh but there + + align:start position:0% +particular filmmakers uh but there + + + align:start position:0% +particular filmmakers uh but there +they're great men + + align:start position:0% +they're great men + + + align:start position:0% +they're great men +and approached properly one can see what + + align:start position:0% +and approached properly one can see what + + + align:start position:0% +and approached properly one can see what +the depths of their souls are and that's + + align:start position:0% +the depths of their souls are and that's + + + align:start position:0% +the depths of their souls are and that's +all I care about is when I talk about + + align:start position:0% +all I care about is when I talk about + + + align:start position:0% +all I care about is when I talk about +philosophical I don't care whether + + align:start position:0% +philosophical I don't care whether + + + align:start position:0% +philosophical I don't care whether +they've take taken courses called + + align:start position:0% +they've take taken courses called + + + align:start position:0% +they've take taken courses called +philosophy in some University or whether + + align:start position:0% +philosophy in some University or whether + + + align:start position:0% +philosophy in some University or whether +they've written the equivalent of + + align:start position:0% +they've written the equivalent of + + + align:start position:0% +they've written the equivalent of +consecrate of pure reason it's their + + align:start position:0% +consecrate of pure reason it's their + + + align:start position:0% +consecrate of pure reason it's their +having a deep awareness and sensitivity + + align:start position:0% +having a deep awareness and sensitivity + + + align:start position:0% +having a deep awareness and sensitivity +to human what it is to be a human being + + align:start position:0% +to human what it is to be a human being + + + align:start position:0% +to human what it is to be a human being +and then without they knowing + + align:start position:0% +and then without they knowing + + + align:start position:0% +and then without they knowing +necessarily what they're + + align:start position:0% +necessarily what they're + + + align:start position:0% +necessarily what they're +doing introducing that into the + + align:start position:0% +doing introducing that into the + + + align:start position:0% +doing introducing that into the +expressiveness and the meaningfulness of + + align:start position:0% +expressiveness and the meaningfulness of + + + align:start position:0% +expressiveness and the meaningfulness of +their of their work of art but doing it + + align:start position:0% +their of their work of art but doing it + + + align:start position:0% +their of their work of art but doing it +on the basis of absolute technical + + align:start position:0% +on the basis of absolute technical + + + align:start position:0% +on the basis of absolute technical +Mastery since the two cannot be + + align:start position:0% +Mastery since the two cannot be + + + align:start position:0% +Mastery since the two cannot be +separated okay so um I want to go back + + align:start position:0% +separated okay so um I want to go back + + + align:start position:0% +separated okay so um I want to go back +again to that question on why we study + + align:start position:0% +again to that question on why we study + + + align:start position:0% +again to that question on why we study +film you know and so I'll I'll tell you + + align:start position:0% +film you know and so I'll I'll tell you + + + align:start position:0% +film you know and so I'll I'll tell you +a little bit about my own personal view + + align:start position:0% +a little bit about my own personal view + + + align:start position:0% +a little bit about my own personal view +um I'm an engineer um I'm at MIT to do + + align:start position:0% +um I'm an engineer um I'm at MIT to do + + + align:start position:0% +um I'm an engineer um I'm at MIT to do +electrical engineering and what does + + align:start position:0% +electrical engineering and what does + + + align:start position:0% +electrical engineering and what does +that involve that involves solving a lot + + align:start position:0% +that involve that involves solving a lot + + + align:start position:0% +that involve that involves solving a lot +of problems and in general they're + + align:start position:0% +of problems and in general they're + + + align:start position:0% +of problems and in general they're +pretty easy you know like one of the + + align:start position:0% +pretty easy you know like one of the + + + align:start position:0% +pretty easy you know like one of the +hardest problems would probably take + + align:start position:0% +hardest problems would probably take + + + align:start position:0% +hardest problems would probably take +like you know like a couple days to + + align:start position:0% +like you know like a couple days to + + + align:start position:0% +like you know like a couple days to +solve before you figure it out and then + + align:start position:0% +solve before you figure it out and then + + + align:start position:0% +solve before you figure it out and then +you go on and build something as an + + align:start position:0% +you go on and build something as an + + + align:start position:0% +you go on and build something as an +engineer and the attraction of Art and + + align:start position:0% +engineer and the attraction of Art and + + + align:start position:0% +engineer and the attraction of Art and +philosophy is that the problem can never + + align:start position:0% +philosophy is that the problem can never + + + align:start position:0% +philosophy is that the problem can never +really be solved as far as we know you + + align:start position:0% +really be solved as far as we know you + + + align:start position:0% +really be solved as far as we know you +know you can keep on working on it + + align:start position:0% +know you can keep on working on it + + + align:start position:0% +know you can keep on working on it +forever you can keep on trying to figure + + align:start position:0% +forever you can keep on trying to figure + + + align:start position:0% +forever you can keep on trying to figure +out why film is so powerful and you'll + + align:start position:0% +out why film is so powerful and you'll + + + align:start position:0% +out why film is so powerful and you'll +you'll come up with a lot of reasons but + + align:start position:0% +you'll come up with a lot of reasons but + + + align:start position:0% +you'll come up with a lot of reasons but +you won't ever know for sure and as + + align:start position:0% +you won't ever know for sure and as + + + align:start position:0% +you won't ever know for sure and as +problem solvers you know that's + + align:start position:0% +problem solvers you know that's + + + align:start position:0% +problem solvers you know that's +that's I mean we we chose to challenge + + align:start position:0% +that's I mean we we chose to challenge + + + align:start position:0% +that's I mean we we chose to challenge +exactly you know we live on the + + align:start position:0% +exactly you know we live on the + + + align:start position:0% +exactly you know we live on the +challenge and that for me that's why I + + align:start position:0% +challenge and that for me that's why I + + + align:start position:0% +challenge and that for me that's why I +enjoy the challenge as opposed to say + + align:start position:0% +enjoy the challenge as opposed to say + + + align:start position:0% +enjoy the challenge as opposed to say +studying economics or something where + + align:start position:0% +studying economics or something where + + + align:start position:0% +studying economics or something where +the problems are generally solved and + + align:start position:0% +the problems are generally solved and + + + align:start position:0% +the problems are generally solved and +you just learn how to solve problems + + align:start position:0% +you just learn how to solve problems + + + align:start position:0% +you just learn how to solve problems +that have been solved or mathematics + + align:start position:0% +that have been solved or mathematics + + + align:start position:0% +that have been solved or mathematics +yeah where which is an art form based on + + align:start position:0% +yeah where which is an art form based on + + + align:start position:0% +yeah where which is an art form based on +the possibility of of a solution and + + align:start position:0% +the possibility of of a solution and + + + align:start position:0% +the possibility of of a solution and +then the achievement of + + align:start position:0% +then the achievement of + + + align:start position:0% +then the achievement of +it yes Am I Wrong is there are there any + + align:start position:0% +it yes Am I Wrong is there are there any + + + align:start position:0% +it yes Am I Wrong is there are there any +mathematicians here I you came in late + + align:start position:0% +mathematicians here I you came in late + + + align:start position:0% +mathematicians here I you came in late +you I I talked a little about life not + + align:start position:0% +you I I talked a little about life not + + + align:start position:0% +you I I talked a little about life not +being like a mathematical problem with + + align:start position:0% +being like a mathematical problem with + + + align:start position:0% +being like a mathematical problem with +you did I or was that my other class U + + align:start position:0% +you did I or was that my other class U + + + align:start position:0% +you did I or was that my other class U +why it is that I'm a humanist and + + align:start position:0% +why it is that I'm a humanist and + + + align:start position:0% +why it is that I'm a humanist and +pluralist U but in the context of that + + align:start position:0% +pluralist U but in the context of that + + + align:start position:0% +pluralist U but in the context of that +what I believed and what I must have + + align:start position:0% +what I believed and what I must have + + + align:start position:0% +what I believed and what I must have +said to the other class this term was + + align:start position:0% +said to the other class this term was + + + align:start position:0% +said to the other class this term was +that mathematics is a great art form + + align:start position:0% +that mathematics is a great art form + + + align:start position:0% +that mathematics is a great art form +it's a an abstract art form and + + align:start position:0% +it's a an abstract art form and + + + align:start position:0% +it's a an abstract art form and +therefore possibly the greatest of any + + align:start position:0% +therefore possibly the greatest of any + + + align:start position:0% +therefore possibly the greatest of any +pure art form it's pure + + align:start position:0% +pure art form it's pure + + + align:start position:0% +pure art form it's pure +art I'm not talking about useful + + align:start position:0% +art I'm not talking about useful + + + align:start position:0% +art I'm not talking about useful +mathematics I'm talking about um + + align:start position:0% +mathematics I'm talking about um + + + align:start position:0% +mathematics I'm talking about um +mathematics that is not useful uh it + + align:start position:0% +mathematics that is not useful uh it + + + align:start position:0% +mathematics that is not useful uh it +pure mathematics is pure art because it + + align:start position:0% +pure mathematics is pure art because it + + + align:start position:0% +pure mathematics is pure art because it +is purely + + align:start position:0% + + + + align:start position:0% + +abstract and that's because it can be + + align:start position:0% +abstract and that's because it can be + + + align:start position:0% +abstract and that's because it can be +solved and therefore it can be solved + + align:start position:0% +solved and therefore it can be solved + + + align:start position:0% +solved and therefore it can be solved +life is not like that and therefore um + + align:start position:0% +life is not like that and therefore um + + + align:start position:0% +life is not like that and therefore um +apart from the art of mathematics usual + + align:start position:0% +apart from the art of mathematics usual + + + align:start position:0% +apart from the art of mathematics usual +Arts like film and music and literature + + align:start position:0% +Arts like film and music and literature + + + align:start position:0% +Arts like film and music and literature +are are challenging and intriguing + + align:start position:0% +are are challenging and intriguing + + + align:start position:0% +are are challenging and intriguing +particularly to MIT students because you + + align:start position:0% +particularly to MIT students because you + + + align:start position:0% +particularly to MIT students because you +can recognize the problem and it's not + + align:start position:0% +can recognize the problem and it's not + + + align:start position:0% +can recognize the problem and it's not +clear that there is a solution to + + align:start position:0% +clear that there is a solution to + + + align:start position:0% +clear that there is a solution to +it which doesn't mean you shouldn't work + + align:start position:0% +it which doesn't mean you shouldn't work + + + align:start position:0% +it which doesn't mean you shouldn't work +at it um how much time do we have to I + + align:start position:0% +at it um how much time do we have to I + + + align:start position:0% +at it um how much time do we have to I +don't want to have to we have we can go + + align:start position:0% +don't want to have to we have we can go + + + align:start position:0% +don't want to have to we have we can go +on for an hour this way this is very + + align:start position:0% +on for an hour this way this is very + + + align:start position:0% +on for an hour this way this is very +profitable I think okay no do any of you + + align:start position:0% +profitable I think okay no do any of you + + + align:start position:0% +profitable I think okay no do any of you +feel differently than well I just meant + + align:start position:0% +feel differently than well I just meant + + + align:start position:0% +feel differently than well I just meant +because of the movie that we want what + + align:start position:0% +because of the movie that we want what + + + align:start position:0% +because of the movie that we want what +um because we have to watch the movie we + + align:start position:0% +um because we have to watch the movie we + + + align:start position:0% +um because we have to watch the movie we +have an hour before okay okay great um + + align:start position:0% +have an hour before okay okay great um + + + align:start position:0% +have an hour before okay okay great um +so I want to talk a little bit about the + + align:start position:0% +so I want to talk a little bit about the + + + align:start position:0% +so I want to talk a little bit about the +uni uniqueness and power of film as + + align:start position:0% +uni uniqueness and power of film as + + + align:start position:0% +uni uniqueness and power of film as +opposed to other media um so what is + + align:start position:0% +opposed to other media um so what is + + + align:start position:0% +opposed to other media um so what is +what is different about film you know + + align:start position:0% +what is different about film you know + + + align:start position:0% +what is different about film you know +first of all I can display any image + + align:start position:0% +first of all I can display any image + + + align:start position:0% +first of all I can display any image +it's not limited say an artist a paint + + align:start position:0% +it's not limited say an artist a paint + + + align:start position:0% +it's not limited say an artist a paint +artist is limited by the colors he can + + align:start position:0% +artist is limited by the colors he can + + + align:start position:0% +artist is limited by the colors he can +use or the brush I don't know much about + + align:start position:0% +use or the brush I don't know much about + + + align:start position:0% +use or the brush I don't know much about +painting but um the technique that he + + align:start position:0% +painting but um the technique that he + + + align:start position:0% +painting but um the technique that he +has he can't just put anything up there + + align:start position:0% +has he can't just put anything up there + + + align:start position:0% +has he can't just put anything up there +um of course there's sound in film which + + align:start position:0% +um of course there's sound in film which + + + align:start position:0% +um of course there's sound in film which +can be very powerful there's editing + + align:start position:0% +can be very powerful there's editing + + + align:start position:0% +can be very powerful there's editing +special effects and the experience of + + align:start position:0% +special effects and the experience of + + + align:start position:0% +special effects and the experience of +watching film is very different and + + align:start position:0% +watching film is very different and + + + align:start position:0% +watching film is very different and +that's that's unique to film and we + + align:start position:0% +that's that's unique to film and we + + + align:start position:0% +that's that's unique to film and we +there's definitely um advantage and + + align:start position:0% +there's definitely um advantage and + + + align:start position:0% +there's definitely um advantage and +disadvantages I'll mention a few and + + align:start position:0% +disadvantages I'll mention a few and + + + align:start position:0% +disadvantages I'll mention a few and +finally one of the great powers of film + + align:start position:0% +finally one of the great powers of film + + + align:start position:0% +finally one of the great powers of film +to me is that it's just socially + + align:start position:0% +to me is that it's just socially + + + align:start position:0% +to me is that it's just socially +pervasive and acceptable you know like + + align:start position:0% +pervasive and acceptable you know like + + + align:start position:0% +pervasive and acceptable you know like +it's a great tool as an artist a + + align:start position:0% +it's a great tool as an artist a + + + align:start position:0% +it's a great tool as an artist a +director as an artist and that he can + + align:start position:0% +director as an artist and that he can + + + align:start position:0% +director as an artist and that he can +release a film and instantly worldwide + + align:start position:0% +release a film and instantly worldwide + + + align:start position:0% +release a film and instantly worldwide +it's accessible to everyone and + + align:start position:0% +it's accessible to everyone and + + + align:start position:0% +it's accessible to everyone and +I mean that's that's really every + + align:start position:0% +I mean that's that's really every + + + align:start position:0% +I mean that's that's really every +artist's dream you know if if you're an + + align:start position:0% +artist's dream you know if if you're an + + + align:start position:0% +artist's dream you know if if you're an +artist right now and you want to get + + align:start position:0% +artist right now and you want to get + + + align:start position:0% +artist right now and you want to get +your work out film is probably the best + + align:start position:0% +your work out film is probably the best + + + align:start position:0% +your work out film is probably the best +media in which medium in which to do it + + align:start position:0% +media in which medium in which to do it + + + align:start position:0% +media in which medium in which to do it +but there's another dream and that is + + align:start position:0% +but there's another dream and that is + + + align:start position:0% +but there's another dream and that is +once you've achieved that kind of + + align:start position:0% +once you've achieved that kind of + + + align:start position:0% +once you've achieved that kind of +success you care about the audience you + + align:start position:0% +success you care about the audience you + + + align:start position:0% +success you care about the audience you +want to make sure that they know how to + + align:start position:0% +want to make sure that they know how to + + + align:start position:0% +want to make sure that they know how to +look at film exactly and that's that's + + align:start position:0% +look at film exactly and that's that's + + + align:start position:0% +look at film exactly and that's that's +what this kind of course addresses + + align:start position:0% +what this kind of course addresses + + + align:start position:0% +what this kind of course addresses +itself + + align:start position:0% +itself + + + align:start position:0% +itself +to okay so I want to also compare film + + align:start position:0% +to okay so I want to also compare film + + + align:start position:0% +to okay so I want to also compare film +to + + align:start position:0% +to + + + align:start position:0% +to +photography um because similar in some + + align:start position:0% +photography um because similar in some + + + align:start position:0% +photography um because similar in some +ways and very different in other ways so + + align:start position:0% +ways and very different in other ways so + + + align:start position:0% +ways and very different in other ways so +I think the chief difference between + + align:start position:0% +I think the chief difference between + + + align:start position:0% +I think the chief difference between +film and between movies and photography + + align:start position:0% +film and between movies and photography + + + align:start position:0% +film and between movies and photography +is the way they're experienced now in a + + align:start position:0% +is the way they're experienced now in a + + + align:start position:0% +is the way they're experienced now in a +photograph the image is self-sufficient + + align:start position:0% +photograph the image is self-sufficient + + + align:start position:0% +photograph the image is self-sufficient +and the way it's experienced is you look + + align:start position:0% +and the way it's experienced is you look + + + align:start position:0% +and the way it's experienced is you look +at it and your eye may be drawn around + + align:start position:0% +at it and your eye may be drawn around + + + align:start position:0% +at it and your eye may be drawn around +the film I'm sure you've heard I mean + + align:start position:0% +the film I'm sure you've heard I mean + + + align:start position:0% +the film I'm sure you've heard I mean +the photograph sorry and I'm sure you've + + align:start position:0% +the photograph sorry and I'm sure you've + + + align:start position:0% +the photograph sorry and I'm sure you've +heard about artwork which paintings + + align:start position:0% +heard about artwork which paintings + + + align:start position:0% +heard about artwork which paintings +which draw your gaze to a piece of the + + align:start position:0% +which draw your gaze to a piece of the + + + align:start position:0% +which draw your gaze to a piece of the +artwork that's commonly analyzed + + align:start position:0% +artwork that's commonly analyzed + + + align:start position:0% +artwork that's commonly analyzed +something similar is done with + + align:start position:0% +something similar is done with + + + align:start position:0% +something similar is done with +Photography in film it can still be done + + align:start position:0% +Photography in film it can still be done + + + align:start position:0% +Photography in film it can still be done +but not to the same extent because + + align:start position:0% +but not to the same extent because + + + align:start position:0% +but not to the same extent because +you're experiencing constant stream of + + align:start position:0% +you're experiencing constant stream of + + + align:start position:0% +you're experiencing constant stream of +pictures instead of one self-sufficient + + align:start position:0% +pictures instead of one self-sufficient + + + align:start position:0% +pictures instead of one self-sufficient +picture + + align:start position:0% +picture + + + align:start position:0% +picture +um and also the the experience in which + + align:start position:0% +um and also the the experience in which + + + align:start position:0% +um and also the the experience in which +you which you have at a movie theer is + + align:start position:0% +you which you have at a movie theer is + + + align:start position:0% +you which you have at a movie theer is +completely different than um looking at + + align:start position:0% +completely different than um looking at + + + align:start position:0% +completely different than um looking at +a photograph so how do we look at movies + + align:start position:0% +a photograph so how do we look at movies + + + align:start position:0% +a photograph so how do we look at movies +in general you go to a movie theater you + + align:start position:0% +in general you go to a movie theater you + + + align:start position:0% +in general you go to a movie theater you +sit down and you for 2 hours or however + + align:start position:0% +sit down and you for 2 hours or however + + + align:start position:0% +sit down and you for 2 hours or however +long and you watch the film on the + + align:start position:0% +long and you watch the film on the + + + align:start position:0% +long and you watch the film on the +screen what about photography you go to + + align:start position:0% +screen what about photography you go to + + + align:start position:0% +screen what about photography you go to +an art gallery or maybe it's in a + + align:start position:0% +an art gallery or maybe it's in a + + + align:start position:0% +an art gallery or maybe it's in a +magazine at home and so that experience + + align:start position:0% +magazine at home and so that experience + + + align:start position:0% +magazine at home and so that experience +is completely different and I want to + + align:start position:0% +is completely different and I want to + + + align:start position:0% +is completely different and I want to +bring up um an example of a horror movie + + align:start position:0% +bring up um an example of a horror movie + + + align:start position:0% +bring up um an example of a horror movie +now I was actually talking about this + + align:start position:0% +now I was actually talking about this + + + align:start position:0% +now I was actually talking about this +with my roommates yesterday which is why + + align:start position:0% +with my roommates yesterday which is why + + + align:start position:0% +with my roommates yesterday which is why +I bring this up but so why what what is + + align:start position:0% +I bring this up but so why what what is + + + align:start position:0% +I bring this up but so why what what is +it about a horror movie that is so + + align:start position:0% +it about a horror movie that is so + + + align:start position:0% +it about a horror movie that is so +appealing to people um because so so my + + align:start position:0% +appealing to people um because so so my + + + align:start position:0% +appealing to people um because so so my +roommates said that well it's because + + align:start position:0% +roommates said that well it's because + + + align:start position:0% +roommates said that well it's because +makes you feel scared + + align:start position:0% +makes you feel scared + + + align:start position:0% +makes you feel scared +and and to me that kind of makes sense + + align:start position:0% +and and to me that kind of makes sense + + + align:start position:0% +and and to me that kind of makes sense +but why would you want to feel scared + + align:start position:0% +but why would you want to feel scared + + + align:start position:0% +but why would you want to feel scared +you know that you could just go outside + + align:start position:0% +you know that you could just go outside + + + align:start position:0% +you know that you could just go outside +and walk alone at night you know then + + align:start position:0% +and walk alone at night you know then + + + align:start position:0% +and walk alone at night you know then +you feel scared but that's not enjoyable + + align:start position:0% +you feel scared but that's not enjoyable + + + align:start position:0% +you feel scared but that's not enjoyable +so what is it about a a scary movie + + align:start position:0% +so what is it about a a scary movie + + + align:start position:0% +so what is it about a a scary movie +that's enjoyable well I think it's + + align:start position:0% +that's enjoyable well I think it's + + + align:start position:0% +that's enjoyable well I think it's +because you know you're in the theater + + align:start position:0% +because you know you're in the theater + + + align:start position:0% +because you know you're in the theater +you know you're safe but you can still + + align:start position:0% +you know you're safe but you can still + + + align:start position:0% +you know you're safe but you can still +sympathize with the characters that + + align:start position:0% +sympathize with the characters that + + + align:start position:0% +sympathize with the characters that +you're seeing and so I I just bring up + + align:start position:0% +you're seeing and so I I just bring up + + + align:start position:0% +you're seeing and so I I just bring up +this example because it's one of the uh + + align:start position:0% +this example because it's one of the uh + + + align:start position:0% +this example because it's one of the uh +it's something that that the um director + + align:start position:0% +it's something that that the um director + + + align:start position:0% +it's something that that the um director +has to keep in mind for the mental state + + align:start position:0% +has to keep in mind for the mental state + + + align:start position:0% +has to keep in mind for the mental state +of his audience they know they're safe + + align:start position:0% +of his audience they know they're safe + + + align:start position:0% +of his audience they know they're safe +they know they're probably in a theater + + align:start position:0% +they know they're probably in a theater + + + align:start position:0% +they know they're probably in a theater +or at home watching it on TV and and + + align:start position:0% +or at home watching it on TV and and + + + align:start position:0% +or at home watching it on TV and and +this is part of the experience that they + + align:start position:0% +this is part of the experience that they + + + align:start position:0% +this is part of the experience that they +get as they're watching the film and + + align:start position:0% +get as they're watching the film and + + + align:start position:0% +get as they're watching the film and +that's part of the art form that's part + + align:start position:0% +that's part of the art form that's part + + + align:start position:0% +that's part of the art form that's part +of the medium okay we can discuss this + + align:start position:0% +of the medium okay we can discuss this + + + align:start position:0% +of the medium okay we can discuss this +further when you read my chapter on + + align:start position:0% +further when you read my chapter on + + + align:start position:0% +further when you read my chapter on +Hitchcock who who talks a great deal + + align:start position:0% +Hitchcock who who talks a great deal + + + align:start position:0% +Hitchcock who who talks a great deal +about this uh the principle that he + + align:start position:0% +about this uh the principle that he + + + align:start position:0% +about this uh the principle that he +develops is fear and fear not + + align:start position:0% +develops is fear and fear not + + + align:start position:0% +develops is fear and fear not +go ahead okay and um one thing that is + + align:start position:0% +go ahead okay and um one thing that is + + + align:start position:0% +go ahead okay and um one thing that is +really really important about film to me + + align:start position:0% +really really important about film to me + + + align:start position:0% +really really important about film to me +is that it's influenced by all other + + align:start position:0% +is that it's influenced by all other + + + align:start position:0% +is that it's influenced by all other +films that I've seen it's influenced by + + align:start position:0% +films that I've seen it's influenced by + + + align:start position:0% +films that I've seen it's influenced by +everything that I've seen you know + + align:start position:0% +everything that I've seen you know + + + align:start position:0% +everything that I've seen you know +because my experience watching a movie + + align:start position:0% +because my experience watching a movie + + + align:start position:0% +because my experience watching a movie +is going to be different than okay let's + + align:start position:0% +is going to be different than okay let's + + + align:start position:0% +is going to be different than okay let's +take an example of Beauty and the Beast + + align:start position:0% +take an example of Beauty and the Beast + + + align:start position:0% +take an example of Beauty and the Beast +our experience last week watching Beauty + + align:start position:0% +our experience last week watching Beauty + + + align:start position:0% +our experience last week watching Beauty +and the Beast I'm sure was vastly + + align:start position:0% +and the Beast I'm sure was vastly + + + align:start position:0% +and the Beast I'm sure was vastly +different than audiences watching it + + align:start position:0% +different than audiences watching it + + + align:start position:0% +different than audiences watching it +when it first came out and does that + + align:start position:0% +when it first came out and does that + + + align:start position:0% +when it first came out and does that +mean we got a less we saw less of an + + align:start position:0% +mean we got a less we saw less of an + + + align:start position:0% +mean we got a less we saw less of an +artwork I don't think so does it really + + align:start position:0% +artwork I don't think so does it really + + + align:start position:0% +artwork I don't think so does it really +matter to us um does it it's the point + + align:start position:0% +matter to us um does it it's the point + + + align:start position:0% +matter to us um does it it's the point +of our watching that film to try to + + align:start position:0% +of our watching that film to try to + + + align:start position:0% +of our watching that film to try to +recreate the experience of the original + + align:start position:0% +recreate the experience of the original + + + align:start position:0% +recreate the experience of the original +audiences at the time when it came out + + align:start position:0% +audiences at the time when it came out + + + align:start position:0% +audiences at the time when it came out +no I don't think so either I think to us + + align:start position:0% +no I don't think so either I think to us + + + align:start position:0% +no I don't think so either I think to us +it's a it's a whole different piece of + + align:start position:0% +it's a it's a whole different piece of + + + align:start position:0% +it's a it's a whole different piece of +art than to the people back then or even + + align:start position:0% +art than to the people back then or even + + + align:start position:0% +art than to the people back then or even +say me versus someone else in this room + + align:start position:0% +say me versus someone else in this room + + + align:start position:0% +say me versus someone else in this room +we have a completely different way of + + align:start position:0% +we have a completely different way of + + + align:start position:0% +we have a completely different way of +thinking about the movie it it drew out + + align:start position:0% +thinking about the movie it it drew out + + + align:start position:0% +thinking about the movie it it drew out +different emotions in us but I think + + align:start position:0% +different emotions in us but I think + + + align:start position:0% +different emotions in us but I think +that's okay and that's part of that's + + align:start position:0% +that's okay and that's part of that's + + + align:start position:0% +that's okay and that's part of that's +part of the power of art is that it can + + align:start position:0% +part of the power of art is that it can + + + align:start position:0% +part of the power of art is that it can +draw out different emotions different + + align:start position:0% +draw out different emotions different + + + align:start position:0% +draw out different emotions different +thinking from every single person from + + align:start position:0% +thinking from every single person from + + + align:start position:0% +thinking from every single person from +every single time with different + + align:start position:0% +every single time with different + + + align:start position:0% +every single time with different +experiences that watches the movie well + + align:start position:0% +experiences that watches the movie well + + + align:start position:0% +experiences that watches the movie well +let me inter up that uh that movie was + + align:start position:0% +let me inter up that uh that movie was + + + align:start position:0% +let me inter up that uh that movie was +made what 60 years ago almost and it in + + align:start position:0% +made what 60 years ago almost and it in + + + align:start position:0% +made what 60 years ago almost and it in +a world that you can't possibly + + align:start position:0% +a world that you can't possibly + + + align:start position:0% +a world that you can't possibly +appreciate because even your parents + + align:start position:0% +appreciate because even your parents + + + align:start position:0% +appreciate because even your parents +probably weren't born then um and that's + + align:start position:0% +probably weren't born then um and that's + + + align:start position:0% +probably weren't born then um and that's +the difference and people then for the + + align:start position:0% +the difference and people then for the + + + align:start position:0% +the difference and people then for the +people that who saw it they they were + + align:start position:0% +people that who saw it they they were + + + align:start position:0% +people that who saw it they they were +living in that world and you aren't + + align:start position:0% +living in that world and you aren't + + + align:start position:0% +living in that world and you aren't +anymore at the same time and also so + + align:start position:0% +anymore at the same time and also so + + + align:start position:0% +anymore at the same time and also so +that's a big difference another + + align:start position:0% +that's a big difference another + + + align:start position:0% +that's a big difference another +difference is the version you saw last + + align:start position:0% +difference is the version you saw last + + + align:start position:0% +difference is the version you saw last +week uh has been digitalized cleaned up + + align:start position:0% +week uh has been digitalized cleaned up + + + align:start position:0% +week uh has been digitalized cleaned up +restored looks better than it ever did + + align:start position:0% +restored looks better than it ever did + + + align:start position:0% +restored looks better than it ever did +including the first time it was shown it + + align:start position:0% +including the first time it was shown it + + + align:start position:0% +including the first time it was shown it +was probably much more grainy then and + + align:start position:0% +was probably much more grainy then and + + + align:start position:0% +was probably much more grainy then and +here you saw it as a beautiful perfect + + align:start position:0% +here you saw it as a beautiful perfect + + + align:start position:0% +here you saw it as a beautiful perfect +entity in itself true to its spirit + + align:start position:0% +entity in itself true to its spirit + + + align:start position:0% +entity in itself true to its spirit +but not identical to the first seeing so + + align:start position:0% +but not identical to the first seeing so + + + align:start position:0% +but not identical to the first seeing so +that in that sense too it's very + + align:start position:0% +that in that sense too it's very + + + align:start position:0% +that in that sense too it's very +different but I think what's most + + align:start position:0% +different but I think what's most + + + align:start position:0% +different but I think what's most +important is the fact that you're + + align:start position:0% +important is the fact that you're + + + align:start position:0% +important is the fact that you're +different that uh this is happens + + align:start position:0% +different that uh this is happens + + + align:start position:0% +different that uh this is happens +inevitably in the passage of time uh + + align:start position:0% +inevitably in the passage of time uh + + + align:start position:0% +inevitably in the passage of time uh +life um in a sense never repeats itself + + align:start position:0% +life um in a sense never repeats itself + + + align:start position:0% +life um in a sense never repeats itself +you know there is saying about history + + align:start position:0% +you know there is saying about history + + + align:start position:0% +you know there is saying about history +repeating itself but history doesn't + + align:start position:0% +repeating itself but history doesn't + + + align:start position:0% +repeating itself but history doesn't +repeat itself because every moment is a + + align:start position:0% +repeat itself because every moment is a + + + align:start position:0% +repeat itself because every moment is a +function of what happened before and + + align:start position:0% +function of what happened before and + + + align:start position:0% +function of what happened before and +that affects the novelty of that moment + + align:start position:0% +that affects the novelty of that moment + + + align:start position:0% +that affects the novelty of that moment +which then becomes the past for the next + + align:start position:0% +which then becomes the past for the next + + + align:start position:0% +which then becomes the past for the next +moment that life is dynamic it's + + align:start position:0% +moment that life is dynamic it's + + + align:start position:0% +moment that life is dynamic it's +developing and consequently uh in a + + align:start position:0% +developing and consequently uh in a + + + align:start position:0% +developing and consequently uh in a +sense we can't live the past anymore but + + align:start position:0% +sense we can't live the past anymore but + + + align:start position:0% +sense we can't live the past anymore but +we don't have to because as we change + + align:start position:0% +we don't have to because as we change + + + align:start position:0% +we don't have to because as we change +we're capable of aesthetic um aptitudes + + align:start position:0% +we're capable of aesthetic um aptitudes + + + align:start position:0% +we're capable of aesthetic um aptitudes +that didn't exist before so that it's a + + align:start position:0% +that didn't exist before so that it's a + + + align:start position:0% +that didn't exist before so that it's a +very complicated thing because of the + + align:start position:0% +very complicated thing because of the + + + align:start position:0% +very complicated thing because of the +presence of time uh in relation to + + align:start position:0% +presence of time uh in relation to + + + align:start position:0% +presence of time uh in relation to +particularly a temporal uh phenomenon + + align:start position:0% +particularly a temporal uh phenomenon + + + align:start position:0% +particularly a temporal uh phenomenon +like the movie uh the movies it's also + + align:start position:0% +like the movie uh the movies it's also + + + align:start position:0% +like the movie uh the movies it's also +true of uh non-temporal Arts like poetry + + align:start position:0% +true of uh non-temporal Arts like poetry + + + align:start position:0% +true of uh non-temporal Arts like poetry +but wanted to go on okay adding on to + + align:start position:0% +but wanted to go on okay adding on to + + + align:start position:0% +but wanted to go on okay adding on to +that I I strongly believe that recording + + align:start position:0% +that I I strongly believe that recording + + + align:start position:0% +that I I strongly believe that recording +doesn't reproduce reality and a large + + align:start position:0% +doesn't reproduce reality and a large + + + align:start position:0% +doesn't reproduce reality and a large +part of that is based on the experience + + align:start position:0% +part of that is based on the experience + + + align:start position:0% +part of that is based on the experience +that you have as you're as you're + + align:start position:0% +that you have as you're as you're + + + align:start position:0% +that you have as you're as you're +watching whatever has been recorded so + + align:start position:0% +watching whatever has been recorded so + + + align:start position:0% +watching whatever has been recorded so +for example um this class is being + + align:start position:0% +for example um this class is being + + + align:start position:0% +for example um this class is being +recorded and someone somewhere is + + align:start position:0% +recorded and someone somewhere is + + + align:start position:0% +recorded and someone somewhere is +probably going to watch this tap + + align:start position:0% +probably going to watch this tap + + + align:start position:0% +probably going to watch this tap +and their experience is going to be very + + align:start position:0% +and their experience is going to be very + + + align:start position:0% +and their experience is going to be very +different than the experience of + + align:start position:0% +different than the experience of + + + align:start position:0% +different than the experience of +everyone in this class and so they're + + align:start position:0% +everyone in this class and so they're + + + align:start position:0% +everyone in this class and so they're +it's not like by watching the tape + + align:start position:0% +it's not like by watching the tape + + + align:start position:0% +it's not like by watching the tape +they're suddenly sitting in an empty + + align:start position:0% +they're suddenly sitting in an empty + + + align:start position:0% +they're suddenly sitting in an empty +seat in this in this room as realistic + + align:start position:0% +seat in this in this room as realistic + + + align:start position:0% +seat in this in this room as realistic +as a tape may be and that's something to + + align:start position:0% +as a tape may be and that's something to + + + align:start position:0% +as a tape may be and that's something to +keep in mind also and that applies to + + align:start position:0% +keep in mind also and that applies to + + + align:start position:0% +keep in mind also and that applies to +photography as well that that definitely + + align:start position:0% +photography as well that that definitely + + + align:start position:0% +photography as well that that definitely +applies to film so finally I just want + + align:start position:0% +applies to film so finally I just want + + + align:start position:0% +applies to film so finally I just want +to talk a little bit about uh Beauty and + + align:start position:0% +to talk a little bit about uh Beauty and + + + align:start position:0% +to talk a little bit about uh Beauty and +the Beast and also citizen C so Beauty + + align:start position:0% +the Beast and also citizen C so Beauty + + + align:start position:0% +the Beast and also citizen C so Beauty +and the Beast um it's clear that not + + align:start position:0% +and the Beast um it's clear that not + + + align:start position:0% +and the Beast um it's clear that not +supposed to reflect reality since + + align:start position:0% +supposed to reflect reality since + + + align:start position:0% +supposed to reflect reality since +there's a beast you know it's fictional + + align:start position:0% +there's a beast you know it's fictional + + + align:start position:0% +there's a beast you know it's fictional +characters it's AIC Beast who talks yeah + + align:start position:0% +characters it's AIC Beast who talks yeah + + + align:start position:0% +characters it's AIC Beast who talks yeah +fictional fairy tale story you know + + align:start position:0% +fictional fairy tale story you know + + + align:start position:0% +fictional fairy tale story you know +there's the girl that can that can + + align:start position:0% +there's the girl that can that can + + + align:start position:0% +there's the girl that can that can +transport herself with the uh Power of + + align:start position:0% +transport herself with the uh Power of + + + align:start position:0% +transport herself with the uh Power of +the glove and so it's not a realistic + + align:start position:0% +the glove and so it's not a realistic + + + align:start position:0% +the glove and so it's not a realistic +story but it's still powerful at least I + + align:start position:0% +story but it's still powerful at least I + + + align:start position:0% +story but it's still powerful at least I +found it very powerful and why because + + align:start position:0% +found it very powerful and why because + + + align:start position:0% +found it very powerful and why because +it doesn't really reflect real life well + + align:start position:0% +it doesn't really reflect real life well + + + align:start position:0% +it doesn't really reflect real life well +to me it it does reflect real human them + + align:start position:0% +to me it it does reflect real human them + + + align:start position:0% +to me it it does reflect real human them +um most notably the love conquers all + + align:start position:0% +um most notably the love conquers all + + + align:start position:0% +um most notably the love conquers all +theme the the Beast and and Bell are in + + align:start position:0% +theme the the Beast and and Bell are in + + + align:start position:0% +theme the the Beast and and Bell are in +love and this is this you see in real + + align:start position:0% +love and this is this you see in real + + + align:start position:0% +love and this is this you see in real +life and you also see in the movie + + align:start position:0% +life and you also see in the movie + + + align:start position:0% +life and you also see in the movie +and in the movie love wins in the end + + align:start position:0% +and in the movie love wins in the end + + + align:start position:0% +and in the movie love wins in the end +and so in love of some sort that's + + align:start position:0% +and so in love of some sort that's + + + align:start position:0% +and so in love of some sort that's +something we can discuss go ahead and um + + align:start position:0% +something we can discuss go ahead and um + + + align:start position:0% +something we can discuss go ahead and um +so this kind of movie seems to trigger + + align:start position:0% +so this kind of movie seems to trigger + + + align:start position:0% +so this kind of movie seems to trigger +just H basic human humanistic concerns + + align:start position:0% +just H basic human humanistic concerns + + + align:start position:0% +just H basic human humanistic concerns +you know and I I'll just name a couple + + align:start position:0% +you know and I I'll just name a couple + + + align:start position:0% +you know and I I'll just name a couple +things um that the movie that the movie + + align:start position:0% +things um that the movie that the movie + + + align:start position:0% +things um that the movie that the movie +has in it um physical Beauty uh + + align:start position:0% +has in it um physical Beauty uh + + + align:start position:0% +has in it um physical Beauty uh +Forbidden Love These are these are + + align:start position:0% +Forbidden Love These are these are + + + align:start position:0% +Forbidden Love These are these are +common themes that people think about + + align:start position:0% +common themes that people think about + + + align:start position:0% +common themes that people think about +and can easily see reflected in real + + align:start position:0% +and can easily see reflected in real + + + align:start position:0% +and can easily see reflected in real +life no you're not forbidden to love a a + + align:start position:0% +life no you're not forbidden to love a a + + + align:start position:0% +life no you're not forbidden to love a a +monster it's just it's not ordinary it + + align:start position:0% +monster it's just it's not ordinary it + + + align:start position:0% +monster it's just it's not ordinary it +usually doesn't happen it's socially + + align:start position:0% +usually doesn't happen it's socially + + + align:start position:0% +usually doesn't happen it's socially +unacceptable in in the movie which which + + align:start position:0% +unacceptable in in the movie which which + + + align:start position:0% +unacceptable in in the movie which which +is a common theme in real life too um + + align:start position:0% +is a common theme in real life too um + + + align:start position:0% +is a common theme in real life too um +okay so citizen came no let's discuss + + align:start position:0% +okay so citizen came no let's discuss + + + align:start position:0% +okay so citizen came no let's discuss +this first does anybody want to say + + align:start position:0% +this first does anybody want to say + + + align:start position:0% +this first does anybody want to say +anything about Beauty and the + + align:start position:0% +anything about Beauty and the + + + align:start position:0% +anything about Beauty and the +Beast let me make a couple of remarks um + + align:start position:0% +Beast let me make a couple of remarks um + + + align:start position:0% +Beast let me make a couple of remarks um + to who directed it wrote it who was + + align:start position:0% + to who directed it wrote it who was + + + align:start position:0% + to who directed it wrote it who was +this great genius really um told the + + align:start position:0% +this great genius really um told the + + + align:start position:0% +this great genius really um told the +crew particularly the cinematographer + + align:start position:0% +crew particularly the cinematographer + + + align:start position:0% +crew particularly the cinematographer +alak Kon who does a wonderful job and + + align:start position:0% +alak Kon who does a wonderful job and + + + align:start position:0% +alak Kon who does a wonderful job and +Chan Kant + + align:start position:0% +Chan Kant + + + align:start position:0% +Chan Kant +barah um who was the set designer he + + align:start position:0% +barah um who was the set designer he + + + align:start position:0% +barah um who was the set designer he +said what I want to do is to make a + + align:start position:0% +said what I want to do is to make a + + + align:start position:0% +said what I want to do is to make a +documentary of another world of a + + align:start position:0% +documentary of another world of a + + + align:start position:0% +documentary of another world of a +magical world I don't want it to be uh + + align:start position:0% +magical world I don't want it to be uh + + + align:start position:0% +magical world I don't want it to be uh +have Frills and look look like magic I + + align:start position:0% +have Frills and look look like magic I + + + align:start position:0% +have Frills and look look like magic I +wanted to be another world which is + + align:start position:0% +wanted to be another world which is + + + align:start position:0% +wanted to be another world which is +different from ours because it is Magic + + align:start position:0% +different from ours because it is Magic + + + align:start position:0% +different from ours because it is Magic +now he he couldn't have had in mind + + align:start position:0% +now he he couldn't have had in mind + + + align:start position:0% +now he he couldn't have had in mind +beauty and beast that the Disney Studio + + align:start position:0% +beauty and beast that the Disney Studio + + + align:start position:0% +beauty and beast that the Disney Studio +made about 15 years ago which most of + + align:start position:0% +made about 15 years ago which most of + + + align:start position:0% +made about 15 years ago which most of +you may have seen that is that's not a + + align:start position:0% +you may have seen that is that's not a + + + align:start position:0% +you may have seen that is that's not a +documentary of anything that is uh + + align:start position:0% +documentary of anything that is uh + + + align:start position:0% +documentary of anything that is uh +touching your sense of fancy and the + + align:start position:0% +touching your sense of fancy and the + + + align:start position:0% +touching your sense of fancy and the +fantasy uh and that's not what I I read + + align:start position:0% +fantasy uh and that's not what I I read + + + align:start position:0% +fantasy uh and that's not what I I read +a lot about that in my chapter but I + + align:start position:0% +a lot about that in my chapter but I + + + align:start position:0% +a lot about that in my chapter but I +don't want to get into it right now but + + align:start position:0% +don't want to get into it right now but + + + align:start position:0% +don't want to get into it right now but +I want want to mention that as an + + align:start position:0% +I want want to mention that as an + + + align:start position:0% +I want want to mention that as an +alternative to what kto tried for and I + + align:start position:0% +alternative to what kto tried for and I + + + align:start position:0% +alternative to what kto tried for and I +think succeeded he gets us into the mood + + align:start position:0% +think succeeded he gets us into the mood + + + align:start position:0% +think succeeded he gets us into the mood +that of course this is what a beast + + align:start position:0% +that of course this is what a beast + + + align:start position:0% +that of course this is what a beast +would look like and would be talk like + + align:start position:0% +would look like and would be talk like + + + align:start position:0% +would look like and would be talk like +if he were if he were um able to talk + + align:start position:0% +if he were if he were um able to talk + + + align:start position:0% +if he were if he were um able to talk +you know you're involved in that other + + align:start position:0% +you know you're involved in that other + + + align:start position:0% +you know you're involved in that other +reality and um the whole fantasy of it + + align:start position:0% +reality and um the whole fantasy of it + + + align:start position:0% +reality and um the whole fantasy of it +the Magic The Magic Castle and and the + + align:start position:0% +the Magic The Magic Castle and and the + + + align:start position:0% +the Magic The Magic Castle and and the +the Articles like the glove and the + + align:start position:0% +the Articles like the glove and the + + + align:start position:0% +the Articles like the glove and the +mirror that have magical properties uh + + align:start position:0% +mirror that have magical properties uh + + + align:start position:0% +mirror that have magical properties uh +but they're real articles they're real + + align:start position:0% +but they're real articles they're real + + + align:start position:0% +but they're real articles they're real +things in the world and you get a + + align:start position:0% +things in the world and you get a + + + align:start position:0% +things in the world and you get a +feeling for the real + + align:start position:0% +feeling for the real + + + align:start position:0% +feeling for the real +world um + + align:start position:0% +world um + + + align:start position:0% +world um +why did clo do this that itself is a big + + align:start position:0% +why did clo do this that itself is a big + + + align:start position:0% +why did clo do this that itself is a big +story uh and briefly it's + + align:start position:0% +story uh and briefly it's + + + align:start position:0% +story uh and briefly it's +because he was talking about what he + + align:start position:0% +because he was talking about what he + + + align:start position:0% +because he was talking about what he +calls the Poetry of film his his life + + align:start position:0% +calls the Poetry of film his his life + + + align:start position:0% +calls the Poetry of film his his life +output is mainly as a poet he made + + align:start position:0% +output is mainly as a poet he made + + + align:start position:0% +output is mainly as a poet he made +movies starting with the blood of the + + align:start position:0% +movies starting with the blood of the + + + align:start position:0% +movies starting with the blood of the +poet uh which is um uh what's called a + + align:start position:0% +poet uh which is um uh what's called a + + + align:start position:0% +poet uh which is um uh what's called a +surrealist movie but it isn't really but + + align:start position:0% +surrealist movie but it isn't really but + + + align:start position:0% +surrealist movie but it isn't really but +I'll give you an idea and in 1930 + + align:start position:0% +I'll give you an idea and in 1930 + + + align:start position:0% +I'll give you an idea and in 1930 +when he was already over 40 I think and + + align:start position:0% +when he was already over 40 I think and + + + align:start position:0% +when he was already over 40 I think and +then he didn't make another movie for 15 + + align:start position:0% +then he didn't make another movie for 15 + + + align:start position:0% +then he didn't make another movie for 15 +years and that second movie was Beauty + + align:start position:0% +years and that second movie was Beauty + + + align:start position:0% +years and that second movie was Beauty +and the Beast in the meantime he was + + align:start position:0% +and the Beast in the meantime he was + + + align:start position:0% +and the Beast in the meantime he was +turning out volume after volume of + + align:start position:0% +turning out volume after volume of + + + align:start position:0% +turning out volume after volume of +poetry uh stage plays novels stories + + align:start position:0% +poetry uh stage plays novels stories + + + align:start position:0% +poetry uh stage plays novels stories +everything but always as a poet and uh + + align:start position:0% +everything but always as a poet and uh + + + align:start position:0% +everything but always as a poet and uh +his uh attraction to the film was that + + align:start position:0% +his uh attraction to the film was that + + + align:start position:0% +his uh attraction to the film was that +he saw that there's an aspect of film + + align:start position:0% +he saw that there's an aspect of film + + + align:start position:0% +he saw that there's an aspect of film +that is or can be + + align:start position:0% +that is or can be + + + align:start position:0% +that is or can be +poetic but + + align:start position:0% +poetic but + + + align:start position:0% +poetic but +he distinguishes between poetry itself + + align:start position:0% +he distinguishes between poetry itself + + + align:start position:0% +he distinguishes between poetry itself +and the poetic he says the poetic is + + align:start position:0% +and the poetic he says the poetic is + + + align:start position:0% +and the poetic he says the poetic is +what people uh uh try to emulate when + + align:start position:0% +what people uh uh try to emulate when + + + align:start position:0% +what people uh uh try to emulate when +they're being superficial they're trying + + align:start position:0% +they're being superficial they're trying + + + align:start position:0% +they're being superficial they're trying +to act poetically you know you get the + + align:start position:0% +to act poetically you know you get the + + + align:start position:0% +to act poetically you know you get the +that mood that is being expressed uh and + + align:start position:0% +that mood that is being expressed uh and + + + align:start position:0% +that mood that is being expressed uh and +that's not what that's not what real + + align:start position:0% +that's not what that's not what real + + + align:start position:0% +that's not what that's not what real +life poetry is like that's not what + + align:start position:0% +life poetry is like that's not what + + + align:start position:0% +life poetry is like that's not what +poetry is really like in real life + + align:start position:0% +poetry is really like in real life + + + align:start position:0% +poetry is really like in real life +poetry comes out of the things of + + align:start position:0% +poetry comes out of the things of + + + align:start position:0% +poetry comes out of the things of +everyday life out of common existence + + align:start position:0% +everyday life out of common existence + + + align:start position:0% +everyday life out of common existence +and it comes out in unpr predictable + + align:start position:0% +and it comes out in unpr predictable + + + align:start position:0% +and it comes out in unpr predictable +ways if you look for it you won't find + + align:start position:0% +ways if you look for it you won't find + + + align:start position:0% +ways if you look for it you won't find +it because it hides but if you + + align:start position:0% +it because it hides but if you + + + align:start position:0% +it because it hides but if you +are perceptive and aware of the the + + align:start position:0% +are perceptive and aware of the the + + + align:start position:0% +are perceptive and aware of the the +difference it'll suddenly appear in + + align:start position:0% +difference it'll suddenly appear in + + + align:start position:0% +difference it'll suddenly appear in +unexpected places and for him the + + align:start position:0% +unexpected places and for him the + + + align:start position:0% +unexpected places and for him the +attraction of film is that film lends + + align:start position:0% +attraction of film is that film lends + + + align:start position:0% +attraction of film is that film lends +itself to + + align:start position:0% +itself to + + + align:start position:0% +itself to +that bringing forth of poetry I'll come + + align:start position:0% +that bringing forth of poetry I'll come + + + align:start position:0% +that bringing forth of poetry I'll come +back to this more when we talk about + + align:start position:0% +back to this more when we talk about + + + align:start position:0% +back to this more when we talk about +Wells um and renoa both of whom speak of + + align:start position:0% +Wells um and renoa both of whom speak of + + + align:start position:0% +Wells um and renoa both of whom speak of +poetic effects but they don't analyze it + + align:start position:0% +poetic effects but they don't analyze it + + + align:start position:0% +poetic effects but they don't analyze it +and haven't thought it through as well + + align:start position:0% +and haven't thought it through as well + + + align:start position:0% +and haven't thought it through as well +as cck cck to did uh in in the film uh + + align:start position:0% +as cck cck to did uh in in the film uh + + + align:start position:0% +as cck cck to did uh in in the film uh +there everything is as if it were real + + align:start position:0% +there everything is as if it were real + + + align:start position:0% +there everything is as if it were real +The Farmhouse at the beginning the + + align:start position:0% +The Farmhouse at the beginning the + + + align:start position:0% +The Farmhouse at the beginning the +ordinary life that we accept oh yeah + + align:start position:0% +ordinary life that we accept oh yeah + + + align:start position:0% +ordinary life that we accept oh yeah +that's real a real Farmhouse and it was + + align:start position:0% +that's real a real Farmhouse and it was + + + align:start position:0% +that's real a real Farmhouse and it was +a real Farmhouse um and then the castle + + align:start position:0% +a real Farmhouse um and then the castle + + + align:start position:0% +a real Farmhouse um and then the castle +the castle the Enchanted Castle + + align:start position:0% +the castle the Enchanted Castle + + + align:start position:0% +the castle the Enchanted Castle +uh looks like a real thing except that + + align:start position:0% +uh looks like a real thing except that + + + align:start position:0% +uh looks like a real thing except that +unreal things happen in it but they + + align:start position:0% +unreal things happen in it but they + + + align:start position:0% +unreal things happen in it but they +happen in a way that make it as if in + + align:start position:0% +happen in a way that make it as if in + + + align:start position:0% +happen in a way that make it as if in +another reality there could be arms + + align:start position:0% +another reality there could be arms + + + align:start position:0% +another reality there could be arms +coming out of the walls that hold on + + align:start position:0% +coming out of the walls that hold on + + + align:start position:0% +coming out of the walls that hold on +hold the chandel uh you know candles or + + align:start position:0% +hold the chandel uh you know candles or + + + align:start position:0% +hold the chandel uh you know candles or +that uh pour the wine for you or that + + align:start position:0% +that uh pour the wine for you or that + + + align:start position:0% +that uh pour the wine for you or that +are + + align:start position:0% +are + + + align:start position:0% +are +uh faces embedded in the lle piece that + + align:start position:0% +uh faces embedded in the lle piece that + + + align:start position:0% +uh faces embedded in the lle piece that +keep moving around you remember all that + + align:start position:0% +keep moving around you remember all that + + + align:start position:0% +keep moving around you remember all that +uh all of that is real but in an unreal + + align:start position:0% +uh all of that is real but in an unreal + + + align:start position:0% +uh all of that is real but in an unreal +use and unreal context which is just + + align:start position:0% +use and unreal context which is just + + + align:start position:0% +use and unreal context which is just +what CTO wants um and as a way of + + align:start position:0% +what CTO wants um and as a way of + + + align:start position:0% +what CTO wants um and as a way of +enforcing that he avoided all special + + align:start position:0% +enforcing that he avoided all special + + + align:start position:0% +enforcing that he avoided all special +effects now we live in a world in which + + align:start position:0% +effects now we live in a world in which + + + align:start position:0% +effects now we live in a world in which +special effects have taken over the uh + + align:start position:0% +special effects have taken over the uh + + + align:start position:0% +special effects have taken over the uh +film industry and all visual uh + + align:start position:0% +film industry and all visual uh + + + align:start position:0% +film industry and all visual uh +experiences that we have uh in in his + + align:start position:0% +experiences that we have uh in in his + + + align:start position:0% +experiences that we have uh in in his +day when the movie was made 1945 they + + align:start position:0% +day when the movie was made 1945 they + + + align:start position:0% +day when the movie was made 1945 they +existed though they hadn't gone as far + + align:start position:0% +existed though they hadn't gone as far + + + align:start position:0% +existed though they hadn't gone as far +because they didn't have the computers + + align:start position:0% +because they didn't have the computers + + + align:start position:0% +because they didn't have the computers +at that time uh and he doesn't want it + + align:start position:0% +at that time uh and he doesn't want it + + + align:start position:0% +at that time uh and he doesn't want it +he didn't there's only one special + + align:start position:0% +he didn't there's only one special + + + align:start position:0% +he didn't there's only one special +effect in the movie does anybody + + align:start position:0% + + + + align:start position:0% + +spotted when she disappeared there's the + + align:start position:0% +spotted when she disappeared there's the + + + align:start position:0% +spotted when she disappeared there's the +moment that U Belle has come back to the + + align:start position:0% +moment that U Belle has come back to the + + + align:start position:0% +moment that U Belle has come back to the +farm and dressed gorgeously with her + + align:start position:0% +farm and dressed gorgeously with her + + + align:start position:0% +farm and dressed gorgeously with her +magnificent what is it Collard or + + align:start position:0% +magnificent what is it Collard or + + + align:start position:0% +magnificent what is it Collard or +bracelet you that's necklace that's + + align:start position:0% +bracelet you that's necklace that's + + + align:start position:0% +bracelet you that's necklace that's +right and U uh her sister obviously + + align:start position:0% +right and U uh her sister obviously + + + align:start position:0% +right and U uh her sister obviously +envies it and she takes it off to hand + + align:start position:0% +envies it and she takes it off to hand + + + align:start position:0% +envies it and she takes it off to hand +it to her sister the minute it leaves + + align:start position:0% +it to her sister the minute it leaves + + + align:start position:0% +it to her sister the minute it leaves +her hands it turns into a cluster of + + align:start position:0% +her hands it turns into a cluster of + + + align:start position:0% +her hands it turns into a cluster of +rope that falls to the ground that's a + + align:start position:0% +rope that falls to the ground that's a + + + align:start position:0% +rope that falls to the ground that's a +special effect it's the only + + align:start position:0% +special effect it's the only + + + align:start position:0% +special effect it's the only +one uh and we don't we're used to that + + align:start position:0% +one uh and we don't we're used to that + + + align:start position:0% +one uh and we don't we're used to that +so we don't even notice it um so the + + align:start position:0% +so we don't even notice it um so the + + + align:start position:0% +so we don't even notice it um so the +tuo's idea what's interesting in the + + align:start position:0% +tuo's idea what's interesting in the + + + align:start position:0% +tuo's idea what's interesting in the +movie is that it is like the doc a + + align:start position:0% +movie is that it is like the doc a + + + align:start position:0% +movie is that it is like the doc a +documentary of of another world and that + + align:start position:0% +documentary of of another world and that + + + align:start position:0% +documentary of of another world and that +poses questions about the meaningfulness + + align:start position:0% +poses questions about the meaningfulness + + + align:start position:0% +poses questions about the meaningfulness +which uh I mustn't start because um you + + align:start position:0% +which uh I mustn't start because um you + + + align:start position:0% +which uh I mustn't start because um you +know I've written n 9,000 words already + + align:start position:0% +know I've written n 9,000 words already + + + align:start position:0% +know I've written n 9,000 words already +and I'm only half + + align:start position:0% +and I'm only half + + + align:start position:0% +and I'm only half +finished go ahead okay so I just want to + + align:start position:0% +finished go ahead okay so I just want to + + + align:start position:0% +finished go ahead okay so I just want to +say to wrap up a few words on citizen K + + align:start position:0% +say to wrap up a few words on citizen K + + + align:start position:0% +say to wrap up a few words on citizen K +okay let's go to Citizen K unless + + align:start position:0% +okay let's go to Citizen K unless + + + align:start position:0% +okay let's go to Citizen K unless +somebody wants to say something about it + + align:start position:0% +somebody wants to say something about it + + + align:start position:0% +somebody wants to say something about it +did you all get something out of that + + align:start position:0% +did you all get something out of that + + + align:start position:0% +did you all get something out of that +movie I thought it would be get + + align:start position:0% +movie I thought it would be get + + + align:start position:0% +movie I thought it would be get +increasingly more meaningful to you + + align:start position:0% +increasingly more meaningful to you + + + align:start position:0% +increasingly more meaningful to you +especially after you've had a chance to + + align:start position:0% +especially after you've had a chance to + + + align:start position:0% +especially after you've had a chance to +read the discussion about formalism and + + align:start position:0% +read the discussion about formalism and + + + align:start position:0% +read the discussion about formalism and +realism because it uses both it use it + + align:start position:0% +realism because it uses both it use it + + + align:start position:0% +realism because it uses both it use it +has trick formal tricks like uh uh the + + align:start position:0% +has trick formal tricks like uh uh the + + + align:start position:0% +has trick formal tricks like uh uh the +Beast carrying Beauty into her room did + + align:start position:0% +Beast carrying Beauty into her room did + + + align:start position:0% +Beast carrying Beauty into her room did +you notice she's attired the way she was + + align:start position:0% +you notice she's attired the way she was + + + align:start position:0% +you notice she's attired the way she was +on the farm until she goes through the + + align:start position:0% +on the farm until she goes through the + + + align:start position:0% +on the farm until she goes through the +door and then she ends up gorgeously + + align:start position:0% +door and then she ends up gorgeously + + + align:start position:0% +door and then she ends up gorgeously +dressed now that's a formal technique + + align:start position:0% +dressed now that's a formal technique + + + align:start position:0% +dressed now that's a formal technique +it's it's very inventive Citizen Cane is + + align:start position:0% +it's it's very inventive Citizen Cane is + + + align:start position:0% +it's it's very inventive Citizen Cane is +considered the greatest movie ever made + + align:start position:0% +considered the greatest movie ever made + + + align:start position:0% +considered the greatest movie ever made +by many people because it has so many of + + align:start position:0% +by many people because it has so many of + + + align:start position:0% +by many people because it has so many of +those inventive techniques and yet they + + align:start position:0% +those inventive techniques and yet they + + + align:start position:0% +those inventive techniques and yet they +work on another level as well in Cen + + align:start position:0% +work on another level as well in Cen + + + align:start position:0% +work on another level as well in Cen +Kane and also in Beauty and and the + + align:start position:0% +Kane and also in Beauty and and the + + + align:start position:0% +Kane and also in Beauty and and the +Beast anything else any anything any of + + align:start position:0% +Beast anything else any anything any of + + + align:start position:0% +Beast anything else any anything any of +you want to say about that okay let's go + + align:start position:0% +you want to say about that okay let's go + + + align:start position:0% +you want to say about that okay let's go +on to citiz Kane okay I don't know I + + align:start position:0% +on to citiz Kane okay I don't know I + + + align:start position:0% +on to citiz Kane okay I don't know I +don't want to give away too much about + + align:start position:0% +don't want to give away too much about + + + align:start position:0% +don't want to give away too much about +the movie because how many have not seen + + align:start position:0% +the movie because how many have not seen + + + align:start position:0% +the movie because how many have not seen +it I think about half I think + + align:start position:0% +it I think about half I think + + + align:start position:0% +it I think about half I think +but um I've studied it in several other + + align:start position:0% +but um I've studied it in several other + + + align:start position:0% +but um I've studied it in several other +classes and one thing that's often + + align:start position:0% +classes and one thing that's often + + + align:start position:0% +classes and one thing that's often +brought up is just the history of the + + align:start position:0% +brought up is just the history of the + + + align:start position:0% +brought up is just the history of the +film Orson Wells who's the director was + + align:start position:0% +film Orson Wells who's the director was + + + align:start position:0% +film Orson Wells who's the director was +a radio star at the time but had I think + + align:start position:0% +a radio star at the time but had I think + + + align:start position:0% +a radio star at the time but had I think +no experience at all in movies and this + + align:start position:0% +no experience at all in movies and this + + + align:start position:0% +no experience at all in movies and this +was his first film that's true goad and + + align:start position:0% +was his first film that's true goad and + + + align:start position:0% +was his first film that's true goad and +it was a huge success and at the time at + + align:start position:0% +it was a huge success and at the time at + + + align:start position:0% +it was a huge success and at the time at +the time it was just groundbreaking for + + align:start position:0% +the time it was just groundbreaking for + + + align:start position:0% +the time it was just groundbreaking for +things that he did in editing in special + + align:start position:0% +things that he did in editing in special + + + align:start position:0% +things that he did in editing in special +effects especially and also the the + + align:start position:0% +effects especially and also the the + + + align:start position:0% +effects especially and also the the +camera work that's those are the main + + align:start position:0% +camera work that's those are the main + + + align:start position:0% +camera work that's those are the main +things that we studied um one thing that + + align:start position:0% +things that we studied um one thing that + + + align:start position:0% +things that we studied um one thing that +you hear time and time again is deep + + align:start position:0% +you hear time and time again is deep + + + align:start position:0% +you hear time and time again is deep +focus which is Poss I think this is the + + align:start position:0% +focus which is Poss I think this is the + + + align:start position:0% +focus which is Poss I think this is the +first film that really used it people + + align:start position:0% +first film that really used it people + + + align:start position:0% +first film that really used it people +say that and it's not true but it's not + + align:start position:0% +say that and it's not true but it's not + + + align:start position:0% +say that and it's not true but it's not +your fault it's a common mistake um when + + align:start position:0% +your fault it's a common mistake um when + + + align:start position:0% +your fault it's a common mistake um when +you see the movie by renoa called rules + + align:start position:0% +you see the movie by renoa called rules + + + align:start position:0% +you see the movie by renoa called rules +of the game which is also treated as one + + align:start position:0% +of the game which is also treated as one + + + align:start position:0% +of the game which is also treated as one +of the two or three greatest movies ever + + align:start position:0% +of the two or three greatest movies ever + + + align:start position:0% +of the two or three greatest movies ever +made and that you'll be seeing it in + + align:start position:0% +made and that you'll be seeing it in + + + align:start position:0% +made and that you'll be seeing it in +this course you will see examples of + + align:start position:0% +this course you will see examples of + + + align:start position:0% +this course you will see examples of +deep focus and the movie was was made in + + align:start position:0% + + + + align:start position:0% + +1939 before Orson + + align:start position:0% +1939 before Orson + + + align:start position:0% +1939 before Orson +Wells but Orson Wells developed it + + align:start position:0% +Wells but Orson Wells developed it + + + align:start position:0% +Wells but Orson Wells developed it +further and he gets the credit but um + + align:start position:0% +further and he gets the credit but um + + + align:start position:0% +further and he gets the credit but um +not he wasn't the first one go ahead + + align:start position:0% +not he wasn't the first one go ahead + + + align:start position:0% +not he wasn't the first one go ahead +okay so I mean this historical + + align:start position:0% +okay so I mean this historical + + + align:start position:0% +okay so I mean this historical +background is nice but it doesn't really + + align:start position:0% +background is nice but it doesn't really + + + align:start position:0% +background is nice but it doesn't really +affect our viewing experience of the + + align:start position:0% +affect our viewing experience of the + + + align:start position:0% +affect our viewing experience of the +movie and it's still a very powerful + + align:start position:0% +movie and it's still a very powerful + + + align:start position:0% +movie and it's still a very powerful +movie otherwise why would people say + + align:start position:0% +movie otherwise why would people say + + + align:start position:0% +movie otherwise why would people say +it's the greatest movie of all time and + + align:start position:0% +it's the greatest movie of all time and + + + align:start position:0% +it's the greatest movie of all time and +so um as I was watching the movie you + + align:start position:0% +so um as I was watching the movie you + + + align:start position:0% +so um as I was watching the movie you +know I wasn't really impressed by the + + align:start position:0% +know I wasn't really impressed by the + + + align:start position:0% +know I wasn't really impressed by the +special effect of it all because I've + + align:start position:0% +special effect of it all because I've + + + align:start position:0% +special effect of it all because I've +seen them now I've seen them hundreds of + + align:start position:0% +seen them now I've seen them hundreds of + + + align:start position:0% +seen them now I've seen them hundreds of +times already give an + + align:start position:0% +times already give an + + + align:start position:0% +times already give an +example okay um so there's there's one + + align:start position:0% +example okay um so there's there's one + + + align:start position:0% +example okay um so there's there's one +scene where the camera will scroll up um + + align:start position:0% +scene where the camera will scroll up um + + + align:start position:0% +scene where the camera will scroll up um +okay so they'll be on a stage the camera + + align:start position:0% +okay so they'll be on a stage the camera + + + align:start position:0% +okay so they'll be on a stage the camera +will scroll up and then suddenly it'll + + align:start position:0% +will scroll up and then suddenly it'll + + + align:start position:0% +will scroll up and then suddenly it'll +be another another scene it'll show a + + align:start position:0% +be another another scene it'll show a + + + align:start position:0% +be another another scene it'll show a +person clapping and so at the time that + + align:start position:0% +person clapping and so at the time that + + + align:start position:0% +person clapping and so at the time that +was a tough special effect to do without + + align:start position:0% +was a tough special effect to do without + + + align:start position:0% +was a tough special effect to do without +computers without ways of editing now + + align:start position:0% +computers without ways of editing now + + + align:start position:0% +computers without ways of editing now +it's you know it's you see it all the + + align:start position:0% +it's you know it's you see it all the + + + align:start position:0% +it's you know it's you see it all the +time you know a camera will pan and + + align:start position:0% +time you know a camera will pan and + + + align:start position:0% +time you know a camera will pan and +suddenly you'll be in a different scene + + align:start position:0% +suddenly you'll be in a different scene + + + align:start position:0% +suddenly you'll be in a different scene +and that's really easy to do nowadays um + + align:start position:0% +and that's really easy to do nowadays um + + + align:start position:0% +and that's really easy to do nowadays um +uh what you're referring to perhaps is + + align:start position:0% +uh what you're referring to perhaps is + + + align:start position:0% +uh what you're referring to perhaps is +when Kane gives a political speech and + + align:start position:0% +when Kane gives a political speech and + + + align:start position:0% +when Kane gives a political speech and +so you see him on the stage with his + + align:start position:0% +so you see him on the stage with his + + + align:start position:0% +so you see him on the stage with his +this is one of the images that's often + + align:start position:0% +this is one of the images that's often + + + align:start position:0% +this is one of the images that's often +copied uh even on the cover of my that's + + align:start position:0% +copied uh even on the cover of my that's + + + align:start position:0% +copied uh even on the cover of my that's +right the dusk jacket of my book in the + + align:start position:0% +right the dusk jacket of my book in the + + + align:start position:0% +right the dusk jacket of my book in the +wreath where there are excerpts from + + align:start position:0% +wreath where there are excerpts from + + + align:start position:0% +wreath where there are excerpts from +films by Hitchcock and Renoir as well as + + align:start position:0% +films by Hitchcock and Renoir as well as + + + align:start position:0% +films by Hitchcock and Renoir as well as +Wells there's one um vignette that shows + + align:start position:0% +Wells there's one um vignette that shows + + + align:start position:0% +Wells there's one um vignette that shows +Wells with his arm stretched out + + align:start position:0% +Wells with his arm stretched out + + + align:start position:0% +Wells with his arm stretched out +pointing to his own photograph that + + align:start position:0% +pointing to his own photograph that + + + align:start position:0% +pointing to his own photograph that +happens in this scene it's part of his + + align:start position:0% +happens in this scene it's part of his + + + align:start position:0% +happens in this scene it's part of his +political speech it's done in a big + + align:start position:0% +political speech it's done in a big + + + align:start position:0% +political speech it's done in a big +audience a big theater and you + + align:start position:0% +audience a big theater and you + + + align:start position:0% +audience a big theater and you +occasionally get quick shots of people + + align:start position:0% +occasionally get quick shots of people + + + align:start position:0% +occasionally get quick shots of people +in the audience well there were no + + align:start position:0% +in the audience well there were no + + + align:start position:0% +in the audience well there were no +people in the audience that that was + + align:start position:0% +people in the audience that that was + + + align:start position:0% +people in the audience that that was +done with photographs that saved a lot + + align:start position:0% +done with photographs that saved a lot + + + align:start position:0% +done with photographs that saved a lot +of money and uh they there was no need + + align:start position:0% +of money and uh they there was no need + + + align:start position:0% +of money and uh they there was no need +for there to be real people so they did + + align:start position:0% +for there to be real people so they did + + + align:start position:0% +for there to be real people so they did +it that way um in a movie like Titanic + + align:start position:0% +it that way um in a movie like Titanic + + + align:start position:0% +it that way um in a movie like Titanic +um where they have hordes of people in + + align:start position:0% +um where they have hordes of people in + + + align:start position:0% +um where they have hordes of people in +all sorts of scenes a lot of them are + + align:start position:0% +all sorts of scenes a lot of them are + + + align:start position:0% +all sorts of scenes a lot of them are +not real but rather um uh special + + align:start position:0% +not real but rather um uh special + + + align:start position:0% +not real but rather um uh special +effects with with the computer you can + + align:start position:0% +effects with with the computer you can + + + align:start position:0% +effects with with the computer you can +do more of that uh I myself think that + + align:start position:0% +do more of that uh I myself think that + + + align:start position:0% +do more of that uh I myself think that +the computerized things uh for instance + + align:start position:0% +the computerized things uh for instance + + + align:start position:0% +the computerized things uh for instance +in the movie in Titanic but also the one + + align:start position:0% +in the movie in Titanic but also the one + + + align:start position:0% +in the movie in Titanic but also the one +called Pearl Harbor um where they do + + align:start position:0% +called Pearl Harbor um where they do + + + align:start position:0% +called Pearl Harbor um where they do +that a lot at the end for instance that + + align:start position:0% +that a lot at the end for instance that + + + align:start position:0% +that a lot at the end for instance that +it's so obvious that it for me it + + align:start position:0% +it's so obvious that it for me it + + + align:start position:0% +it's so obvious that it for me it +attracted from the value of the movie in + + align:start position:0% +attracted from the value of the movie in + + + align:start position:0% +attracted from the value of the movie in +the case of Wells I don't think I would + + align:start position:0% +the case of Wells I don't think I would + + + align:start position:0% +the case of Wells I don't think I would +ever have noticed this if I hadn't read + + align:start position:0% +ever have noticed this if I hadn't read + + + align:start position:0% +ever have noticed this if I hadn't read +about it uh I'm telling to you now so + + align:start position:0% +about it uh I'm telling to you now so + + + align:start position:0% +about it uh I'm telling to you now so +you can see for yourself that's an + + align:start position:0% +you can see for yourself that's an + + + align:start position:0% +you can see for yourself that's an +example of a special effect and Wells + + align:start position:0% +example of a special effect and Wells + + + align:start position:0% +example of a special effect and Wells +was very Artful in doing that right I + + align:start position:0% +was very Artful in doing that right I + + + align:start position:0% +was very Artful in doing that right I +agree with that I without a computer all + + align:start position:0% +agree with that I without a computer all + + + align:start position:0% +agree with that I without a computer all +all of the effects I really wouldn't + + align:start position:0% +all of the effects I really wouldn't + + + align:start position:0% +all of the effects I really wouldn't +have known if I hadn't listened to the + + align:start position:0% +have known if I hadn't listened to the + + + align:start position:0% +have known if I hadn't listened to the +director's commentary you know where he + + align:start position:0% +director's commentary you know where he + + + align:start position:0% +director's commentary you know where he +talks about how he had to saw a table in + + align:start position:0% +talks about how he had to saw a table in + + + align:start position:0% +talks about how he had to saw a table in +half so that he could open it as he + + align:start position:0% +half so that he could open it as he + + + align:start position:0% +half so that he could open it as he +moved the camera through things like + + align:start position:0% +moved the camera through things like + + + align:start position:0% +moved the camera through things like +that are just nowadays they probably + + align:start position:0% +that are just nowadays they probably + + + align:start position:0% +that are just nowadays they probably +would have some fancier way of doing it + + align:start position:0% +would have some fancier way of doing it + + + align:start position:0% +would have some fancier way of doing it +but it's not something that that is + + align:start position:0% +but it's not something that that is + + + align:start position:0% +but it's not something that that is +really impressive to the modern audience + + align:start position:0% +really impressive to the modern audience + + + align:start position:0% +really impressive to the modern audience +yet Citizen Kane is still a very + + align:start position:0% +yet Citizen Kane is still a very + + + align:start position:0% +yet Citizen Kane is still a very +powerful film and um I don't really know + + align:start position:0% +powerful film and um I don't really know + + + align:start position:0% +powerful film and um I don't really know +exactly why but to me it it there's some + + align:start position:0% +exactly why but to me it it there's some + + + align:start position:0% +exactly why but to me it it there's some +there's some questions and there's some + + align:start position:0% +there's some questions and there's some + + + align:start position:0% +there's some questions and there's some +mysteries in the movie that aren't + + align:start position:0% +mysteries in the movie that aren't + + + align:start position:0% +mysteries in the movie that aren't +really answered and to me that just + + align:start position:0% +really answered and to me that just + + + align:start position:0% +really answered and to me that just +keeps me thinking about it long after + + align:start position:0% +keeps me thinking about it long after + + + align:start position:0% +keeps me thinking about it long after +after I I leave the theater or leave the + + align:start position:0% +after I I leave the theater or leave the + + + align:start position:0% +after I I leave the theater or leave the +room where I've been watching it you + + align:start position:0% +room where I've been watching it you + + + align:start position:0% +room where I've been watching it you +know I just keep reflecting on the movie + + align:start position:0% +know I just keep reflecting on the movie + + + align:start position:0% +know I just keep reflecting on the movie +and to me that's that's the real power + + align:start position:0% +and to me that's that's the real power + + + align:start position:0% +and to me that's that's the real power +of Citizen Kane was the example about + + align:start position:0% +of Citizen Kane was the example about + + + align:start position:0% +of Citizen Kane was the example about +the sewing of the table out of Citizen + + align:start position:0% +the sewing of the table out of Citizen + + + align:start position:0% +the sewing of the table out of Citizen +Kane yeah when he's in the uh when + + align:start position:0% +Kane yeah when he's in the uh when + + + align:start position:0% +Kane yeah when he's in the uh when +Kane's in the in the window off playing + + align:start position:0% +Kane's in the in the window off playing + + + align:start position:0% +Kane's in the in the window off playing +in the snow in the distance as a boy and + + align:start position:0% +in the snow in the distance as a boy and + + + align:start position:0% +in the snow in the distance as a boy and +his his parents are talking and the + + align:start position:0% +his his parents are talking and the + + + align:start position:0% +his his parents are talking and the +camera is behind the table you'll notice + + align:start position:0% +camera is behind the table you'll notice + + + align:start position:0% +camera is behind the table you'll notice +it and then the camera moves forward I + + align:start position:0% +it and then the camera moves forward I + + + align:start position:0% +it and then the camera moves forward I +see and they had to chop the table in + + align:start position:0% +see and they had to chop the table in + + + align:start position:0% +see and they had to chop the table in +half to get + + align:start position:0% +half to get + + + align:start position:0% +half to get +Wells was a professional magician and + + align:start position:0% +Wells was a professional magician and + + + align:start position:0% +Wells was a professional magician and +that shows up in various + + align:start position:0% +that shows up in various + + + align:start position:0% +that shows up in various +ways you you know he saw ladies in + + align:start position:0% +ways you you know he saw ladies in + + + align:start position:0% +ways you you know he saw ladies in +half go ahead okay so I I think that's I + + align:start position:0% +half go ahead okay so I I think that's I + + + align:start position:0% +half go ahead okay so I I think that's I +think I hit all the main points that I + + align:start position:0% +think I hit all the main points that I + + + align:start position:0% +think I hit all the main points that I +want well that's Splendid I think that's + + align:start position:0% +want well that's Splendid I think that's + + + align:start position:0% +want well that's Splendid I think that's +a very good presentation and we have + + align:start position:0% +a very good presentation and we have + + + align:start position:0% +a very good presentation and we have +time for anybody else to say + + align:start position:0% +time for anybody else to say + + + align:start position:0% +time for anybody else to say +something um I just wanted to say + + align:start position:0% +something um I just wanted to say + + + align:start position:0% +something um I just wanted to say +something about um Beauty and the Beast + + align:start position:0% +something about um Beauty and the Beast + + + align:start position:0% +something about um Beauty and the Beast +like something that I thought was + + align:start position:0% +like something that I thought was + + + align:start position:0% +like something that I thought was +interesting was the communication that + + align:start position:0% +interesting was the communication that + + + align:start position:0% +interesting was the communication that +um he tried to have with the audience + + align:start position:0% +um he tried to have with the audience + + + align:start position:0% +um he tried to have with the audience +especially like even just the beginning + + align:start position:0% +especially like even just the beginning + + + align:start position:0% +especially like even just the beginning +before the movie started you know how he + + align:start position:0% +before the movie started you know how he + + + align:start position:0% +before the movie started you know how he +was like well um just take your + + align:start position:0% +was like well um just take your + + + align:start position:0% +was like well um just take your +preconceptions of Beauty and the Beast + + align:start position:0% +preconceptions of Beauty and the Beast + + + align:start position:0% +preconceptions of Beauty and the Beast +and just humor me in this film and watch + + align:start position:0% +and just humor me in this film and watch + + + align:start position:0% +and just humor me in this film and watch +it in a different way I thought that was + + align:start position:0% +it in a different way I thought that was + + + align:start position:0% +it in a different way I thought that was +very interesting that he he set up the + + align:start position:0% +very interesting that he he set up the + + + align:start position:0% +very interesting that he he set up the +movie like that and actually came out + + align:start position:0% +movie like that and actually came out + + + align:start position:0% +movie like that and actually came out +and said that and then um I don't know + + align:start position:0% +and said that and then um I don't know + + + align:start position:0% +and said that and then um I don't know +well he he says that in order to uh + + align:start position:0% +well he he says that in order to uh + + + align:start position:0% +well he he says that in order to uh +awaken your imagination the way he + + align:start position:0% +awaken your imagination the way he + + + align:start position:0% +awaken your imagination the way he +thinks it would be for children in other + + align:start position:0% +thinks it would be for children in other + + + align:start position:0% +thinks it would be for children in other +words be a child but it's not a movie + + align:start position:0% +words be a child but it's not a movie + + + align:start position:0% +words be a child but it's not a movie +for children I don't think children + + align:start position:0% +for children I don't think children + + + align:start position:0% +for children I don't think children +would get much out of it but that's + + align:start position:0% +would get much out of it but that's + + + align:start position:0% +would get much out of it but that's +that's the mode of expression notice + + align:start position:0% +that's the mode of expression notice + + + align:start position:0% +that's the mode of expression notice +that the credits are put on in a school + + align:start position:0% +that the credits are put on in a school + + + align:start position:0% +that the credits are put on in a school +room and he is like the teacher who + + align:start position:0% +room and he is like the teacher who + + + align:start position:0% +room and he is like the teacher who +writes it on the Blackboard but then the + + align:start position:0% +writes it on the Blackboard but then the + + + align:start position:0% +writes it on the Blackboard but then the +actors who are dressed not in their + + align:start position:0% +actors who are dressed not in their + + + align:start position:0% +actors who are dressed not in their +costumes but as real people they come up + + align:start position:0% +costumes but as real people they come up + + + align:start position:0% +costumes but as real people they come up +and they erase it so there is that play + + align:start position:0% +and they erase it so there is that play + + + align:start position:0% +and they erase it so there is that play +uh which is very clever I think yeah so + + align:start position:0% +uh which is very clever I think yeah so + + + align:start position:0% +uh which is very clever I think yeah so +it's also like the reality of like + + align:start position:0% +it's also like the reality of like + + + align:start position:0% +it's also like the reality of like +trying to show the reality of magic like + + align:start position:0% +trying to show the reality of magic like + + + align:start position:0% +trying to show the reality of magic like +trying to put yourself in that and that + + align:start position:0% +trying to put yourself in that and that + + + align:start position:0% +trying to put yourself in that and that +I thought that was something in a theme + + align:start position:0% +I thought that was something in a theme + + + align:start position:0% +I thought that was something in a theme +through the whole movie you + + align:start position:0% +through the whole movie you + + + align:start position:0% +through the whole movie you +know why don't we go because otherwise + + align:start position:0% +know why don't we go because otherwise + + + align:start position:0% +know why don't we go because otherwise +it'll run after um + + align:start position:0% +it'll run after um + + + align:start position:0% +it'll run after um +I made myself be in a little late who + + align:start position:0% +I made myself be in a little late who + + + align:start position:0% +I made myself be in a little late who +was it put the movie in last + + align:start position:0% + + + + align:start position:0% + +time person who put it in I say uh he's + + align:start position:0% +time person who put it in I say uh he's + + + align:start position:0% +time person who put it in I say uh he's +the person who put it in the last time + + align:start position:0% +the person who put it in the last time + + + align:start position:0% +the person who put it in the last time +he's not here today oh he's not here + + align:start position:0% +he's not here today oh he's not here + + + align:start position:0% +he's not here today oh he's not here +today yeah can any of you manage this or + + align:start position:0% +today yeah can any of you manage this or + + + align:start position:0% +today yeah can any of you manage this or +you really know because there's some + + align:start position:0% +you really know because there's some + + + align:start position:0% +you really know because there's some +trouble with the DVD there okay put it + + align:start position:0% +trouble with the DVD there okay put it + + + align:start position:0% +trouble with the DVD there okay put it +in and uh if I'm not back started anyhow + + align:start position:0% +in and uh if I'm not back started anyhow + + + align:start position:0% +in and uh if I'm not back started anyhow +but I'll try very hard to get back in + + align:start position:0% +but I'll try very hard to get back in + + + align:start position:0% +but I'll try very hard to get back in +time in the meantime could you make out + + align:start position:0% +time in the meantime could you make out + + + align:start position:0% +time in the meantime could you make out +um a card \ No newline at end of file diff --git a/X9eErxRjQEI.txt b/X9eErxRjQEI.txt new file mode 100644 index 0000000000000000000000000000000000000000..4476502a7e22afa515b6de55e9bd214bdb9337f2 --- /dev/null +++ b/X9eErxRjQEI.txt @@ -0,0 +1,12121 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer high quality educational + + align:start position:0% +to offer high quality educational + + + align:start position:0% +to offer high quality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay let's get + + align:start position:0% +ocw.mit.edu okay let's get + + + align:start position:0% +ocw.mit.edu okay let's get +started uh last time we looked at a + + align:start position:0% +started uh last time we looked at a + + + align:start position:0% +started uh last time we looked at a +variety of ways to analyze sums and + + align:start position:0% +variety of ways to analyze sums and + + + align:start position:0% +variety of ways to analyze sums and +Define closed form expressions for the + + align:start position:0% +Define closed form expressions for the + + + align:start position:0% +Define closed form expressions for the +sums and today we're going to use those + + align:start position:0% +sums and today we're going to use those + + + align:start position:0% +sums and today we're going to use those +methods to solve uh a variety of famous + + align:start position:0% +methods to solve uh a variety of famous + + + align:start position:0% +methods to solve uh a variety of famous +problems one of them involving uh Center + + align:start position:0% +problems one of them involving uh Center + + + align:start position:0% +problems one of them involving uh Center +of mass and and stacking blocks uh we + + align:start position:0% +of mass and and stacking blocks uh we + + + align:start position:0% +of mass and and stacking blocks uh we +saw a version of that yesterday in + + align:start position:0% +saw a version of that yesterday in + + + align:start position:0% +saw a version of that yesterday in +recitation where you solved the problem + + align:start position:0% +recitation where you solved the problem + + + align:start position:0% +recitation where you solved the problem +of figuring out how many uh L's you need + + align:start position:0% +of figuring out how many uh L's you need + + + align:start position:0% +of figuring out how many uh L's you need +to make something like this balanced + + align:start position:0% +to make something like this balanced + + + align:start position:0% +to make something like this balanced +perfectly uh now in this case I didn't + + align:start position:0% +perfectly uh now in this case I didn't + + + align:start position:0% +perfectly uh now in this case I didn't +actually get an interg number of L's + + align:start position:0% +actually get an interg number of L's + + + align:start position:0% +actually get an interg number of L's +which is possible because I didn't quite + + align:start position:0% +which is possible because I didn't quite + + + align:start position:0% +which is possible because I didn't quite +get it stacked right at the bottom so I + + align:start position:0% +get it stacked right at the bottom so I + + + align:start position:0% +get it stacked right at the bottom so I +got 10 and a half L's here there's an + + align:start position:0% +got 10 and a half L's here there's an + + + align:start position:0% +got 10 and a half L's here there's an +extra vertical here now in theory there + + align:start position:0% +extra vertical here now in theory there + + + align:start position:0% +extra vertical here now in theory there +are two integer ways of doing it and you + + align:start position:0% +are two integer ways of doing it and you + + + align:start position:0% +are two integer ways of doing it and you +Pro that yesterday in recitation So in + + align:start position:0% +Pro that yesterday in recitation So in + + + align:start position:0% +Pro that yesterday in recitation So in +theory 10 and 11 should work but in + + align:start position:0% +theory 10 and 11 should work but in + + + align:start position:0% +theory 10 and 11 should work but in +practice the blocks aren't perfect I + + align:start position:0% +practice the blocks aren't perfect I + + + align:start position:0% +practice the blocks aren't perfect I +didn't get them perfectly lined up and + + align:start position:0% +didn't get them perfectly lined up and + + + align:start position:0% +didn't get them perfectly lined up and +so 10 wouldn't quite work and 11 tended + + align:start position:0% +so 10 wouldn't quite work and 11 tended + + + align:start position:0% +so 10 wouldn't quite work and 11 tended +to pitch it the other way and of course + + align:start position:0% +to pitch it the other way and of course + + + align:start position:0% +to pitch it the other way and of course +in theory as long as the center of mass + + align:start position:0% +in theory as long as the center of mass + + + align:start position:0% +in theory as long as the center of mass +is just anywhere over this block it's + + align:start position:0% +is just anywhere over this block it's + + + align:start position:0% +is just anywhere over this block it's +going to be stable you know in practice + + align:start position:0% +going to be stable you know in practice + + + align:start position:0% +going to be stable you know in practice +there's air moving around and bouncing + + align:start position:0% +there's air moving around and bouncing + + + align:start position:0% +there's air moving around and bouncing +and stuff and so if you're close to the + + align:start position:0% +and stuff and so if you're close to the + + + align:start position:0% +and stuff and so if you're close to the +edge it's it's going + + align:start position:0% +edge it's it's going + + + align:start position:0% +edge it's it's going +over okay so now if you want to build + + align:start position:0% +over okay so now if you want to build + + + align:start position:0% +over okay so now if you want to build +one of these yourself it's not hard to + + align:start position:0% +one of these yourself it's not hard to + + + align:start position:0% +one of these yourself it's not hard to +do um you just start with an extra block + + align:start position:0% +do um you just start with an extra block + + + align:start position:0% +do um you just start with an extra block +here all right and then you build up and + + align:start position:0% +here all right and then you build up and + + + align:start position:0% +here all right and then you build up and +that's easy and then you notice when + + align:start position:0% +that's easy and then you notice when + + + align:start position:0% +that's easy and then you notice when +it's about right you know and you can + + align:start position:0% +it's about right you know and you can + + + align:start position:0% +it's about right you know and you can +start wiggling this block out and then + + align:start position:0% +start wiggling this block out and then + + + align:start position:0% +start wiggling this block out and then +then it looks pretty cool at that point + + align:start position:0% +then it looks pretty cool at that point + + + align:start position:0% +then it looks pretty cool at that point +uh actually it was a student in the + + align:start position:0% +uh actually it was a student in the + + + align:start position:0% +uh actually it was a student in the +class showed me this + + align:start position:0% +class showed me this + + + align:start position:0% +class showed me this +um a couple years ago because we were + + align:start position:0% +um a couple years ago because we were + + + align:start position:0% +um a couple years ago because we were +doing the blocks the next thing we're + + align:start position:0% +doing the blocks the next thing we're + + + align:start position:0% +doing the blocks the next thing we're +going to do we were doing that and he + + align:start position:0% +going to do we were doing that and he + + + align:start position:0% +going to do we were doing that and he +said hey there's this thing and it's + + align:start position:0% +said hey there's this thing and it's + + + align:start position:0% +said hey there's this thing and it's +pretty cool uh so today we're going to + + align:start position:0% +pretty cool uh so today we're going to + + + align:start position:0% +pretty cool uh so today we're going to +look at a different problem and that's + + align:start position:0% +look at a different problem and that's + + + align:start position:0% +look at a different problem and that's +the problem of getting the blocks + + align:start position:0% +the problem of getting the blocks + + + align:start position:0% +the problem of getting the blocks +stacked up so they go out over the edge + + align:start position:0% +stacked up so they go out over the edge + + + align:start position:0% +stacked up so they go out over the edge +of the table if that's + + align:start position:0% +of the table if that's + + + align:start position:0% +of the table if that's +doable uh so the + + align:start position:0% + + + + align:start position:0% + +goal is + + align:start position:0% +goal is + + + align:start position:0% +goal is +to stack the blocks up + + align:start position:0% +to stack the blocks up + + + align:start position:0% +to stack the blocks up +like this we go farther and farther out + + align:start position:0% +like this we go farther and farther out + + + align:start position:0% +like this we go farther and farther out +and the question we're going to look at + + align:start position:0% +and the question we're going to look at + + + align:start position:0% +and the question we're going to look at +is is it + + align:start position:0% +is is it + + + align:start position:0% +is is it +possible + + align:start position:0% +possible + + + align:start position:0% +possible +whoa almost is it possible to get a + + align:start position:0% +whoa almost is it possible to get a + + + align:start position:0% +whoa almost is it possible to get a +block all the way off the table that's + + align:start position:0% +block all the way off the table that's + + + align:start position:0% +block all the way off the table that's +the question we're going to look at and + + align:start position:0% +the question we're going to look at and + + + align:start position:0% +the question we're going to look at and +here I got I got close and you can see + + align:start position:0% +here I got I got close and you can see + + + align:start position:0% +here I got I got close and you can see +it's getting a little Tippy oh it's not + + align:start position:0% +it's getting a little Tippy oh it's not + + + align:start position:0% +it's getting a little Tippy oh it's not +going to go it's going to fall over if I + + align:start position:0% +going to go it's going to fall over if I + + + align:start position:0% +going to go it's going to fall over if I +so that's so I didn't do it this time um + + align:start position:0% +so that's so I didn't do it this time um + + + align:start position:0% +so that's so I didn't do it this time um +you're only allowed one block per level + + align:start position:0% +you're only allowed one block per level + + + align:start position:0% +you're only allowed one block per level +so you can't you can't do uh you know + + align:start position:0% +so you can't you can't do uh you know + + + align:start position:0% +so you can't you can't do uh you know +anything like this that's not allowed + + align:start position:0% +anything like this that's not allowed + + + align:start position:0% +anything like this that's not allowed +you can go + + align:start position:0% +you can go + + + align:start position:0% +you can go +backwards you know if that helps you you + + align:start position:0% +backwards you know if that helps you you + + + align:start position:0% +backwards you know if that helps you you +well it's got to be stable on both sides + + align:start position:0% +well it's got to be stable on both sides + + + align:start position:0% +well it's got to be stable on both sides +but you can go back and forth um so the + + align:start position:0% +but you can go back and forth um so the + + + align:start position:0% +but you can go back and forth um so the +question is can you get out one block + + align:start position:0% +question is can you get out one block + + + align:start position:0% +question is can you get out one block +totally out over the table how many + + align:start position:0% +totally out over the table how many + + + align:start position:0% +totally out over the table how many +people think it can't be + + align:start position:0% +people think it can't be + + + align:start position:0% +people think it can't be +done right a few doubs oh more doubs how + + align:start position:0% +done right a few doubs oh more doubs how + + + align:start position:0% +done right a few doubs oh more doubs how +many think it can be done oh a lot of + + align:start position:0% +many think it can be done oh a lot of + + + align:start position:0% +many think it can be done oh a lot of +people think it can be done okay well + + align:start position:0% +people think it can be done okay well + + + align:start position:0% +people think it can be done okay well +all + + align:start position:0% +all + + + align:start position:0% +all +right how many people think you can get + + align:start position:0% +right how many people think you can get + + + align:start position:0% +right how many people think you can get +a + + align:start position:0% +a + + + align:start position:0% +a +block two blocks out over the + + align:start position:0% +block two blocks out over the + + + align:start position:0% +block two blocks out over the +table a few of you how many think you + + align:start position:0% +table a few of you how many think you + + + align:start position:0% +table a few of you how many think you +can get it three blocks + + align:start position:0% +can get it three blocks + + + align:start position:0% +can get it three blocks +out ah you're Believers okay how many + + align:start position:0% +out ah you're Believers okay how many + + + align:start position:0% +out ah you're Believers okay how many +people think I can reach that + + align:start position:0% +people think I can reach that + + + align:start position:0% +people think I can reach that +wall well I got to tell you I can't + + align:start position:0% +wall well I got to tell you I can't + + + align:start position:0% +wall well I got to tell you I can't +reach the wall + + align:start position:0% +reach the wall + + + align:start position:0% +reach the wall +because yeah you know that's going to be + + align:start position:0% +because yeah you know that's going to be + + + align:start position:0% +because yeah you know that's going to be +hard to do uh but this is what we're + + align:start position:0% +hard to do uh but this is what we're + + + align:start position:0% +hard to do uh but this is what we're +going to we're going to try to figure + + align:start position:0% +going to we're going to try to figure + + + align:start position:0% +going to we're going to try to figure +out and we're going to do it with a + + align:start position:0% +out and we're going to do it with a + + + align:start position:0% +out and we're going to do it with a +little competition so we're going to + + align:start position:0% +little competition so we're going to + + + align:start position:0% +little competition so we're going to +have a team of you go up against the + + align:start position:0% +have a team of you go up against the + + + align:start position:0% +have a team of you go up against the +Tas and the winner gets candy to + + align:start position:0% +Tas and the winner gets candy to + + + align:start position:0% +Tas and the winner gets candy to +share the losing team gets the infamous + + align:start position:0% +share the losing team gets the infamous + + + align:start position:0% +share the losing team gets the infamous +6042 nerd Pride pocket + + align:start position:0% +6042 nerd Pride pocket + + + align:start position:0% +6042 nerd Pride pocket +protectors very nice you know shiny + + align:start position:0% +protectors very nice you know shiny + + + align:start position:0% +protectors very nice you know shiny +plastic has the MIT logo on them very + + align:start position:0% +plastic has the MIT logo on them very + + + align:start position:0% +plastic has the MIT logo on them very +handy all right so I need four + + align:start position:0% +handy all right so I need four + + + align:start position:0% +handy all right so I need four +volunteers so come on down if you'd like + + align:start position:0% +volunteers so come on down if you'd like + + + align:start position:0% +volunteers so come on down if you'd like +to volunteer you can win some candy for + + align:start position:0% +to volunteer you can win some candy for + + + align:start position:0% +to volunteer you can win some candy for +the class or at least win yourself a + + align:start position:0% +the class or at least win yourself a + + + align:start position:0% +the class or at least win yourself a +pocket + + align:start position:0% +pocket + + + align:start position:0% +pocket +protector and we'll put the class over + + align:start position:0% +protector and we'll put the class over + + + align:start position:0% +protector and we'll put the class over +there and we get the Tas to come + + align:start position:0% +there and we get the Tas to come + + + align:start position:0% +there and we get the Tas to come +down so come on down I got a couple of + + align:start position:0% +down so come on down I got a couple of + + + align:start position:0% +down so come on down I got a couple of +people who else wants to join them all + + align:start position:0% +people who else wants to join them all + + + align:start position:0% +people who else wants to join them all +right come on down we got a fourth + + align:start position:0% +right come on down we got a fourth + + + align:start position:0% +right come on down we got a fourth +volunteer out + + align:start position:0% + + + + align:start position:0% + +there all right we got some people + + align:start position:0% +there all right we got some people + + + align:start position:0% +there all right we got some people +coming down all right come on over + + align:start position:0% +coming down all right come on over + + + align:start position:0% +coming down all right come on over +all right you got all the blocks you + + align:start position:0% +all right you got all the blocks you + + + align:start position:0% +all right you got all the blocks you +want we can even take this thing down so + + align:start position:0% +want we can even take this thing down so + + + align:start position:0% +want we can even take this thing down so +here's your here's your + + align:start position:0% +here's your here's your + + + align:start position:0% +here's your here's your +supply all right now the Tas have a + + align:start position:0% +supply all right now the Tas have a + + + align:start position:0% +supply all right now the Tas have a +little bit of an advantage because + + align:start position:0% +little bit of an advantage because + + + align:start position:0% +little bit of an advantage because +they've done this before some of them uh + + align:start position:0% +they've done this before some of them uh + + + align:start position:0% +they've done this before some of them uh +so you can give some advice to your + + align:start position:0% +so you can give some advice to your + + + align:start position:0% +so you can give some advice to your +colleagues here so you got to get some + + align:start position:0% +colleagues here so you got to get some + + + align:start position:0% +colleagues here so you got to get some +blocks out of the block supply maybe we + + align:start position:0% +blocks out of the block supply maybe we + + + align:start position:0% +blocks out of the block supply maybe we +should take this down it's about to fall + + align:start position:0% +should take this down it's about to fall + + + align:start position:0% +should take this down it's about to fall +over + + align:start position:0% +over + + + align:start position:0% +over +anyway so yeah how do we get this down + + align:start position:0% +anyway so yeah how do we get this down + + + align:start position:0% +anyway so yeah how do we get this down +not sure + + align:start position:0% +not sure + + + align:start position:0% +not sure +all right I got this + + align:start position:0% + + + + align:start position:0% + +end whoa there we go + + align:start position:0% + + + + align:start position:0% + +who all + + align:start position:0% +who all + + + align:start position:0% +who all +right there we + + align:start position:0% + + + + align:start position:0% + +go so whoever gets a block out over the + + align:start position:0% +go so whoever gets a block out over the + + + align:start position:0% +go so whoever gets a block out over the +farthest wins one block per level you + + align:start position:0% +farthest wins one block per level you + + + align:start position:0% +farthest wins one block per level you +can't do two blocks on a level believe + + align:start position:0% +can't do two blocks on a level believe + + + align:start position:0% +can't do two blocks on a level believe +me it's a lot easier if you can do multi + + align:start position:0% +me it's a lot easier if you can do multi + + + align:start position:0% +me it's a lot easier if you can do multi +M blocks per + + align:start position:0% + + + + align:start position:0% + +level you can go back and forth go ahead + + align:start position:0% +level you can go back and forth go ahead + + + align:start position:0% +level you can go back and forth go ahead +and give them some advice they look like + + align:start position:0% +and give them some advice they look like + + + align:start position:0% +and give them some advice they look like +they need + + align:start position:0% +they need + + + align:start position:0% +they need +it they're only about half a block out + + align:start position:0% +it they're only about half a block out + + + align:start position:0% +it they're only about half a block out +so + + align:start position:0% + + + + align:start position:0% + +far how are the Tas doing here + + align:start position:0% + + + + align:start position:0% + +all right the Tas are getting scientific + + align:start position:0% +all right the Tas are getting scientific + + + align:start position:0% +all right the Tas are getting scientific +here you know it's not looking good for + + align:start position:0% +here you know it's not looking good for + + + align:start position:0% +here you know it's not looking good for +you guys to get the candy today I gotta + + align:start position:0% +you guys to get the candy today I gotta + + + align:start position:0% +you guys to get the candy today I gotta +tell + + align:start position:0% + + + + align:start position:0% + +you oh Tas are close + + align:start position:0% + + + + align:start position:0% + +all right you got oh you're about two3 + + align:start position:0% +all right you got oh you're about two3 + + + align:start position:0% +all right you got oh you're about two3 +of the way over we got one + + align:start position:0% +of the way over we got one + + + align:start position:0% +of the way over we got one +2/3 got an inch to go yeah maybe it's + + align:start position:0% +2/3 got an inch to go yeah maybe it's + + + align:start position:0% +2/3 got an inch to go yeah maybe it's +not doable it's not the first time we've + + align:start position:0% +not doable it's not the first time we've + + + align:start position:0% +not doable it's not the first time we've +done this + + align:start position:0% +done this + + + align:start position:0% +done this +and and the problem has not been + + align:start position:0% + + + + align:start position:0% + +solvable oh Tas are close they're + + align:start position:0% +solvable oh Tas are close they're + + + align:start position:0% +solvable oh Tas are close they're +definitely within an + + align:start position:0% +definitely within an + + + align:start position:0% +definitely within an +inch uh maybe an inch and a half + + align:start position:0% + + + + align:start position:0% + +yeah you can't hold it it's got to stand + + align:start position:0% +yeah you can't hold it it's got to stand + + + align:start position:0% +yeah you can't hold it it's got to stand +up by + + align:start position:0% + + + + align:start position:0% + +itself now the bottom block can go out + + align:start position:0% +itself now the bottom block can go out + + + align:start position:0% +itself now the bottom block can go out +over the edge if you + + align:start position:0% + + + + align:start position:0% + +want oh they're getting + + align:start position:0% +want oh they're getting + + + align:start position:0% +want oh they're getting +close oh I think you might you might + + align:start position:0% +close oh I think you might you might + + + align:start position:0% +close oh I think you might you might +have the but the top block out over + + align:start position:0% + + + + align:start position:0% + +maybe how you guys + + align:start position:0% + + + + align:start position:0% + +doing not good this is this is trouble + + align:start position:0% +doing not good this is this is trouble + + + align:start position:0% +doing not good this is this is trouble +for + + align:start position:0% + + + + align:start position:0% + +the you got it yeah oh all right you + + align:start position:0% +the you got it yeah oh all right you + + + align:start position:0% +the you got it yeah oh all right you +gota you got to work fast now if you're + + align:start position:0% +gota you got to work fast now if you're + + + align:start position:0% +gota you got to work fast now if you're +gonna beat that ta's got it out over the + + align:start position:0% +gonna beat that ta's got it out over the + + + align:start position:0% +gonna beat that ta's got it out over the +edge you see that they're out over the + + align:start position:0% +edge you see that they're out over the + + + align:start position:0% +edge you see that they're out over the +edge all right I think they did it + + align:start position:0% + + + + align:start position:0% + +we're going to have a hard time + + align:start position:0% +we're going to have a hard time + + + align:start position:0% +we're going to have a hard time +analyzing that + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% + + + + align:start position:0% + +no all right we'll try another block or + + align:start position:0% +no all right we'll try another block or + + + align:start position:0% +no all right we'll try another block or +two and then we'll uh + + align:start position:0% + + + + align:start position:0% + +vote looks like the stat Center yeah + + align:start position:0% +vote looks like the stat Center yeah + + + align:start position:0% +vote looks like the stat Center yeah +that's it + + align:start position:0% + + + + align:start position:0% + +uh you're + + align:start position:0% + + + + align:start position:0% + +close you're not the most efficient + + align:start position:0% +close you're not the most efficient + + + align:start position:0% +close you're not the most efficient +that's for + + align:start position:0% + + + + align:start position:0% + +sure yeah the Tas are already munching + + align:start position:0% +sure yeah the Tas are already munching + + + align:start position:0% +sure yeah the Tas are already munching +down here this is + + align:start position:0% + + + + align:start position:0% + +Sol now there's an + + align:start position:0% + + + + align:start position:0% + +idea all right well I think it's time + + align:start position:0% +idea all right well I think it's time + + + align:start position:0% +idea all right well I think it's time +for a + + align:start position:0% +for a + + + align:start position:0% +for a +vote but let the class see what you did + + align:start position:0% +vote but let the class see what you did + + + align:start position:0% +vote but let the class see what you did +REM yeah you got to take your hands off + + align:start position:0% +REM yeah you got to take your hands off + + + align:start position:0% +REM yeah you got to take your hands off +that's you know we're just choosing not + + align:start position:0% + + + + align:start position:0% + +to I'll get some good top balancing on + + align:start position:0% + + + + align:start position:0% + +there I don't know + + align:start position:0% + + + + align:start position:0% + +all right can you let it go all right + + align:start position:0% +all right can you let it go all right + + + align:start position:0% +all right can you let it go all right +they let it go all right let's see did + + align:start position:0% +they let it go all right let's see did + + + align:start position:0% +they let it go all right let's see did +you get one + + align:start position:0% +you get one + + + align:start position:0% +you get one +out all right we're going to do a vote + + align:start position:0% +out all right we're going to do a vote + + + align:start position:0% +out all right we're going to do a vote +who thinks they got the one farthest + + align:start position:0% +who thinks they got the one farthest + + + align:start position:0% +who thinks they got the one farthest +out oh it's close oh look at that we + + align:start position:0% +out oh it's close oh look at that we + + + align:start position:0% +out oh it's close oh look at that we +need some glasses out there who thinks + + align:start position:0% +need some glasses out there who thinks + + + align:start position:0% +need some glasses out there who thinks +the TA has got it farther + + align:start position:0% +the TA has got it farther + + + align:start position:0% +the TA has got it farther +out oh man all rightor tower all right + + align:start position:0% +out oh man all rightor tower all right + + + align:start position:0% +out oh man all rightor tower all right +so you guys here you go very nice pocket + + align:start position:0% +so you guys here you go very nice pocket + + + align:start position:0% +so you guys here you go very nice pocket +protect a good effort right there you + + align:start position:0% +protect a good effort right there you + + + align:start position:0% +protect a good effort right there you +are well + + align:start position:0% +are well + + + align:start position:0% +are well +done and I'm afraid they get the candy + + align:start position:0% +done and I'm afraid they get the candy + + + align:start position:0% +done and I'm afraid they get the candy +here so you can take these out and share + + align:start position:0% +here so you can take these out and share + + + align:start position:0% +here so you can take these out and share +them with the + + align:start position:0% +them with the + + + align:start position:0% +them with the +class oh leave it that way leave it + + align:start position:0% +class oh leave it that way leave it + + + align:start position:0% +class oh leave it that way leave it +there I'm we're going to analyze yours + + align:start position:0% +there I'm we're going to analyze yours + + + align:start position:0% +there I'm we're going to analyze yours +because I can't begin to analyze + + align:start position:0% + + + + align:start position:0% + +that all right now watching this how + + align:start position:0% +that all right now watching this how + + + align:start position:0% +that all right now watching this how +many people still think we can get it + + align:start position:0% +many people still think we can get it + + + align:start position:0% +many people still think we can get it +all the way to the + + align:start position:0% +all the way to the + + + align:start position:0% +all the way to the +wall a few people in fact if you stack + + align:start position:0% +wall a few people in fact if you stack + + + align:start position:0% +wall a few people in fact if you stack +this high enough and we're going to + + align:start position:0% +this high enough and we're going to + + + align:start position:0% +this high enough and we're going to +analyze how high it has to go you could + + align:start position:0% +analyze how high it has to go you could + + + align:start position:0% +analyze how high it has to go you could +reach the wall now in fact we're going + + align:start position:0% +reach the wall now in fact we're going + + + align:start position:0% +reach the wall now in fact we're going +to find that you probably got to go out + + align:start position:0% +to find that you probably got to go out + + + align:start position:0% +to find that you probably got to go out +to the Stars to get that high before you + + align:start position:0% +to the Stars to get that high before you + + + align:start position:0% +to the Stars to get that high before you +can reach the wall so it's not too + + align:start position:0% +can reach the wall so it's not too + + + align:start position:0% +can reach the wall so it's not too +practical now what I want to do is + + align:start position:0% +practical now what I want to do is + + + align:start position:0% +practical now what I want to do is +analyze this strategy and this sort of + + align:start position:0% +analyze this strategy and this sort of + + + align:start position:0% +analyze this strategy and this sort of +looks like a nice design they got out + + align:start position:0% +looks like a nice design they got out + + + align:start position:0% +looks like a nice design they got out +there with just five and they did a a + + align:start position:0% +there with just five and they did a a + + + align:start position:0% +there with just five and they did a a +particular approach using what we could + + align:start position:0% +particular approach using what we could + + + align:start position:0% +particular approach using what we could +call as the greedy algorithm you know + + align:start position:0% +call as the greedy algorithm you know + + + align:start position:0% +call as the greedy algorithm you know +we've seen greedy algorithms before and + + align:start position:0% +we've seen greedy algorithms before and + + + align:start position:0% +we've seen greedy algorithms before and +they used another greedy algorithm here + + align:start position:0% +they used another greedy algorithm here + + + align:start position:0% +they used another greedy algorithm here +now what their greedy strategy did and + + align:start position:0% +now what their greedy strategy did and + + + align:start position:0% +now what their greedy strategy did and +I'm going to redo it + + align:start position:0% +I'm going to redo it + + + align:start position:0% +I'm going to redo it +here is stack all the blocks right at + + align:start position:0% +here is stack all the blocks right at + + + align:start position:0% +here is stack all the blocks right at +the edge line it up + + align:start position:0% +the edge line it up + + + align:start position:0% +the edge line it up +here and starting at the Top push it out + + align:start position:0% +here and starting at the Top push it out + + + align:start position:0% +here and starting at the Top push it out +as far as you can go now in this case we + + align:start position:0% +as far as you can go now in this case we + + + align:start position:0% +as far as you can go now in this case we +can get it out about halfway because the + + align:start position:0% +can get it out about halfway because the + + + align:start position:0% +can get it out about halfway because the +center of mass of this block is at + + align:start position:0% +center of mass of this block is at + + + align:start position:0% +center of mass of this block is at +halfway point and that better be sitting + + align:start position:0% +halfway point and that better be sitting + + + align:start position:0% +halfway point and that better be sitting +over this block or it's going to + + align:start position:0% +over this block or it's going to + + + align:start position:0% +over this block or it's going to +tip so the top block goes out here now + + align:start position:0% +tip so the top block goes out here now + + + align:start position:0% +tip so the top block goes out here now +I'm going to slide the top two blocks + + align:start position:0% +I'm going to slide the top two blocks + + + align:start position:0% +I'm going to slide the top two blocks +out as far as they + + align:start position:0% + + + + align:start position:0% + +go all right that's about the tip then I + + align:start position:0% +go all right that's about the tip then I + + + align:start position:0% +go all right that's about the tip then I +slide the top three out as far as they + + align:start position:0% + + + + align:start position:0% + +go + + align:start position:0% +go + + + align:start position:0% +go +almost oops theory is always easier than + + align:start position:0% +almost oops theory is always easier than + + + align:start position:0% +almost oops theory is always easier than +practice and now we do the top four + + align:start position:0% +practice and now we do the top four + + + align:start position:0% +practice and now we do the top four +blocks and they did a better job than I + + align:start position:0% +blocks and they did a better job than I + + + align:start position:0% +blocks and they did a better job than I +did but that's the algorithm okay the + + align:start position:0% +did but that's the algorithm okay the + + + align:start position:0% +did but that's the algorithm okay the +greedy algorithm you just the top ey + + align:start position:0% +greedy algorithm you just the top ey + + + align:start position:0% +greedy algorithm you just the top ey +blocks from I goes one to n push it out + + align:start position:0% +blocks from I goes one to n push it out + + + align:start position:0% +blocks from I goes one to n push it out +as far as you can go all right and we're + + align:start position:0% +as far as you can go all right and we're + + + align:start position:0% +as far as you can go all right and we're +going to analyze that + + align:start position:0% + + + + align:start position:0% + +strategy and see how far it + + align:start position:0% + + + + align:start position:0% + +goes so we're given + + align:start position:0% +goes so we're given + + + align:start position:0% +goes so we're given +n blocks and let's say they all have + + align:start position:0% +n blocks and let's say they all have + + + align:start position:0% +n blocks and let's say they all have +length one to make it + + align:start position:0% + + + + align:start position:0% + +easy and we're going to + + align:start position:0% +easy and we're going to + + + align:start position:0% +easy and we're going to +Define r sub I to be the amount by which + + align:start position:0% +Define r sub I to be the amount by which + + + align:start position:0% +Define r sub I to be the amount by which +the I block hangs out over the edge + + align:start position:0% + + + + align:start position:0% + +and we're going to count from the + + align:start position:0% + + + + align:start position:0% + +top all right so let's see this on a + + align:start position:0% +top all right so let's see this on a + + + align:start position:0% +top all right so let's see this on a +picture so I got the table + + align:start position:0% + + + + align:start position:0% + +here and then I'm stacking the blocks + + align:start position:0% +here and then I'm stacking the blocks + + + align:start position:0% +here and then I'm stacking the blocks +out + + align:start position:0% +out + + + align:start position:0% +out +in some way like + + align:start position:0% +in some way like + + + align:start position:0% +in some way like +this and with the greedy strategy you + + align:start position:0% +this and with the greedy strategy you + + + align:start position:0% +this and with the greedy strategy you +don't ever go + + align:start position:0% + + + + align:start position:0% + +backwards all right so I'm + + align:start position:0% +backwards all right so I'm + + + align:start position:0% +backwards all right so I'm +defining this distance this is block + + align:start position:0% +defining this distance this is block + + + align:start position:0% +defining this distance this is block +one this distance + + align:start position:0% + + + + align:start position:0% + +here is + + align:start position:0% +here is + + + align:start position:0% +here is +R1 this + + align:start position:0% +R1 this + + + align:start position:0% +R1 this +distance is + + align:start position:0% +distance is + + + align:start position:0% +distance is +R2 this one is R3 and so forth until you + + align:start position:0% +R2 this one is R3 and so forth until you + + + align:start position:0% +R2 this one is R3 and so forth until you +get down to here this is + + align:start position:0% +get down to here this is + + + align:start position:0% +get down to here this is +RN because this is the nth block and it + + align:start position:0% +RN because this is the nth block and it + + + align:start position:0% +RN because this is the nth block and it +extends out RN from the table and this + + align:start position:0% +extends out RN from the table and this + + + align:start position:0% +extends out RN from the table and this +is zero here which in the table we'll + + align:start position:0% +is zero here which in the table we'll + + + align:start position:0% +is zero here which in the table we'll +consider the table to be the N plus + + align:start position:0% +consider the table to be the N plus + + + align:start position:0% +consider the table to be the N plus +first block so RN + one is + + align:start position:0% +first block so RN + one is + + + align:start position:0% +first block so RN + one is +zero okay and so using the strategy the + + align:start position:0% +zero okay and so using the strategy the + + + align:start position:0% +zero okay and so using the strategy the +greedy strategy we want to know what's + + align:start position:0% +greedy strategy we want to know what's + + + align:start position:0% +greedy strategy we want to know what's +R1 we want to compute that if I keep + + align:start position:0% +R1 we want to compute that if I keep + + + align:start position:0% +R1 we want to compute that if I keep +pushing the the blocks out in a topw + + align:start position:0% +pushing the the blocks out in a topw + + + align:start position:0% +pushing the the blocks out in a topw +fashion as far as they'll go now the + + align:start position:0% +fashion as far as they'll go now the + + + align:start position:0% +fashion as far as they'll go now the +constraint is the stability constraint + + align:start position:0% +constraint is the stability constraint + + + align:start position:0% +constraint is the stability constraint +so it won't fall + + align:start position:0% + + + + align:start position:0% + +over the stability constraint says that + + align:start position:0% +over the stability constraint says that + + + align:start position:0% +over the stability constraint says that +the center of + + align:start position:0% + + + + align:start position:0% + +mass we'll call it + + align:start position:0% +mass we'll call it + + + align:start position:0% +mass we'll call it +CK of the top K block + + align:start position:0% + + + + align:start position:0% + +X must lie on the K plus first block + + align:start position:0% +X must lie on the K plus first block + + + align:start position:0% +X must lie on the K plus first block +otherwise it'll tip + + align:start position:0% + + + + align:start position:0% + +over and of course the table is block n + + align:start position:0% +over and of course the table is block n + + + align:start position:0% +over and of course the table is block n +plus one in this context + + align:start position:0% + + + + align:start position:0% + +okay so if at any point we've got K + + align:start position:0% +okay so if at any point we've got K + + + align:start position:0% +okay so if at any point we've got K +blocks and their Center of mass is out + + align:start position:0% +blocks and their Center of mass is out + + + align:start position:0% +blocks and their Center of mass is out +here they'll fall over at that point or + + align:start position:0% +here they'll fall over at that point or + + + align:start position:0% +here they'll fall over at that point or +if you were building it this way they + + align:start position:0% +if you were building it this way they + + + align:start position:0% +if you were building it this way they +would fall over that way right so for + + align:start position:0% +would fall over that way right so for + + + align:start position:0% +would fall over that way right so for +each set of the top K blocks the center + + align:start position:0% +each set of the top K blocks the center + + + align:start position:0% +each set of the top K blocks the center +of mass has to be on the Block below and + + align:start position:0% +of mass has to be on the Block below and + + + align:start position:0% +of mass has to be on the Block below and +if it is we're fine it won't fall + + align:start position:0% + + + + align:start position:0% + +over now for the greedy stacking + + align:start position:0% + + + + align:start position:0% + +where is the center of mass of the top K + + align:start position:0% +where is the center of mass of the top K + + + align:start position:0% +where is the center of mass of the top K +blocks in the greedy stacking the way we + + align:start position:0% +blocks in the greedy stacking the way we + + + align:start position:0% +blocks in the greedy stacking the way we +defin + + align:start position:0% +defin + + + align:start position:0% +defin +it in terms of these variables what is + + align:start position:0% + + + + align:start position:0% + +CK right so I got the top K blocks + + align:start position:0% + + + + align:start position:0% + +r k + one the center of mass of the top + + align:start position:0% +r k + one the center of mass of the top + + + align:start position:0% +r k + one the center of mass of the top +K blocks by the greedy strategy is right + + align:start position:0% +K blocks by the greedy strategy is right + + + align:start position:0% +K blocks by the greedy strategy is right +at the edge of the K block so if this is + + align:start position:0% +at the edge of the K block so if this is + + + align:start position:0% +at the edge of the K block so if this is +block K here then this is RK + + + align:start position:0% +block K here then this is RK + + + + align:start position:0% +block K here then this is RK + +one that's where the center of mass has + + align:start position:0% +one that's where the center of mass has + + + align:start position:0% +one that's where the center of mass has +to be of all these blocks the top K + + align:start position:0% +to be of all these blocks the top K + + + align:start position:0% +to be of all these blocks the top K +blocks if it's a little bit more it's + + align:start position:0% +blocks if it's a little bit more it's + + + align:start position:0% +blocks if it's a little bit more it's +going to fall over if it's less then + + align:start position:0% +going to fall over if it's less then + + + align:start position:0% +going to fall over if it's less then +it's not greedy we didn't push it out as + + align:start position:0% +it's not greedy we didn't push it out as + + + align:start position:0% +it's not greedy we didn't push it out as +far as it could go all right + + align:start position:0% +far as it could go all right + + + align:start position:0% +far as it could go all right +so for the greedy stacking CK is equal + + align:start position:0% +so for the greedy stacking CK is equal + + + align:start position:0% +so for the greedy stacking CK is equal +to RK + + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +and RN + one of course is the edge of + + align:start position:0% +and RN + one of course is the edge of + + + align:start position:0% +and RN + one of course is the edge of +the table that's + + align:start position:0% + + + + align:start position:0% + +zero any questions so + + align:start position:0% +zero any questions so + + + align:start position:0% +zero any questions so +far what we're + + align:start position:0% +far what we're + + + align:start position:0% +far what we're +doing okay all right so let's figure out + + align:start position:0% +doing okay all right so let's figure out + + + align:start position:0% +doing okay all right so let's figure out +where the center of mass of the top K + + align:start position:0% +where the center of mass of the top K + + + align:start position:0% +where the center of mass of the top K +blocks is you know a formula for that a + + align:start position:0% +blocks is you know a formula for that a + + + align:start position:0% +blocks is you know a formula for that a +recursive formula + + align:start position:0% +recursive formula + + + align:start position:0% +recursive formula +so to do that we look at the center of + + align:start position:0% +so to do that we look at the center of + + + align:start position:0% +so to do that we look at the center of +mass of the kith block by itself and + + align:start position:0% +mass of the kith block by itself and + + + align:start position:0% +mass of the kith block by itself and +then average it in with the center of + + align:start position:0% +then average it in with the center of + + + align:start position:0% +then average it in with the center of +mass of the top K minus one + + align:start position:0% +mass of the top K minus one + + + align:start position:0% +mass of the top K minus one +blocks okay so we're going to set up a + + align:start position:0% +blocks okay so we're going to set up a + + + align:start position:0% +blocks okay so we're going to set up a +recursion to compute + + align:start position:0% +recursion to compute + + + align:start position:0% +recursion to compute +CK where is the center of mass of the + + align:start position:0% +CK where is the center of mass of the + + + align:start position:0% +CK where is the center of mass of the +kith + + align:start position:0% +kith + + + align:start position:0% +kith +block just by itself the center of mass + + align:start position:0% +block just by itself the center of mass + + + align:start position:0% +block just by itself the center of mass +of the kith + + align:start position:0% +of the kith + + + align:start position:0% +of the kith +block this guy where's it Center of mass + + align:start position:0% + + + + align:start position:0% + +yeah RK +1 minus 0.5 because it's the + + align:start position:0% +yeah RK +1 minus 0.5 because it's the + + + align:start position:0% +yeah RK +1 minus 0.5 because it's the +center of mass of this block is a half + + align:start position:0% +center of mass of this block is a half + + + align:start position:0% +center of mass of this block is a half +from the right Edge and the right Edge + + align:start position:0% +from the right Edge and the right Edge + + + align:start position:0% +from the right Edge and the right Edge +is oh it's + + align:start position:0% +is oh it's + + + align:start position:0% +is oh it's +RK sorry right the top yeah this is what + + align:start position:0% +RK sorry right the top yeah this is what + + + align:start position:0% +RK sorry right the top yeah this is what +did I do here oh the top k sorry this is + + align:start position:0% +did I do here oh the top k sorry this is + + + align:start position:0% +did I do here oh the top k sorry this is +the Ki block the way I had it here's the + + align:start position:0% +the Ki block the way I had it here's the + + + align:start position:0% +the Ki block the way I had it here's the +K so it is RK minus a half that's right + + align:start position:0% +K so it is RK minus a half that's right + + + align:start position:0% +K so it is RK minus a half that's right +this is RK plus one down here + + align:start position:0% +this is RK plus one down here + + + align:start position:0% +this is RK plus one down here +all right because the right edge of the + + align:start position:0% +all right because the right edge of the + + + align:start position:0% +all right because the right edge of the +C block is at RK the center of mass is a + + align:start position:0% +C block is at RK the center of mass is a + + + align:start position:0% +C block is at RK the center of mass is a +half left of + + align:start position:0% +half left of + + + align:start position:0% +half left of +that all right so we know that the + + align:start position:0% +that all right so we know that the + + + align:start position:0% +that all right so we know that the +center of + + align:start position:0% + + + + align:start position:0% + +mass of the Ki + + align:start position:0% + + + + align:start position:0% + +block is at RK minus a + + align:start position:0% +block is at RK minus a + + + align:start position:0% +block is at RK minus a +half all right now we can compute + + align:start position:0% +half all right now we can compute + + + align:start position:0% +half all right now we can compute +another expression for CK + + align:start position:0% + + + + align:start position:0% + +Center of + + align:start position:0% + + + + align:start position:0% + +mass of the top K + + align:start position:0% + + + + align:start position:0% + +blocks + + align:start position:0% +blocks + + + align:start position:0% +blocks +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +is + + align:start position:0% +is + + + align:start position:0% +is +CK equals well there's K minus one + + align:start position:0% +CK equals well there's K minus one + + + align:start position:0% +CK equals well there's K minus one +blocks centered at CK + + align:start position:0% +blocks centered at CK + + + align:start position:0% +blocks centered at CK +minus1 because the center of mass of the + + align:start position:0% +minus1 because the center of mass of the + + + align:start position:0% +minus1 because the center of mass of the +top K minus1 blocks by definition is C + + align:start position:0% +top K minus1 blocks by definition is C + + + align:start position:0% +top K minus1 blocks by definition is C +kus1 and they have weight K + + align:start position:0% +kus1 and they have weight K + + + align:start position:0% +kus1 and they have weight K +minus1 and then we average that with a + + align:start position:0% +minus1 and then we average that with a + + + align:start position:0% +minus1 and then we average that with a +Ki block that has weight one at position + + align:start position:0% +Ki block that has weight one at position + + + align:start position:0% +Ki block that has weight one at position +r k minus a + + align:start position:0% +r k minus a + + + align:start position:0% +r k minus a +half and the total weight of this is K + + align:start position:0% +half and the total weight of this is K + + + align:start position:0% +half and the total weight of this is K +minus one here and one for this block so + + align:start position:0% +minus one here and one for this block so + + + align:start position:0% +minus one here and one for this block so +this equals K CK minus one plus sorry + + align:start position:0% +this equals K CK minus one plus sorry + + + align:start position:0% +this equals K CK minus one plus sorry +minus let me write it better here k + + align:start position:0% +minus let me write it better here k + + + align:start position:0% +minus let me write it better here k +minus1 c k - + + align:start position:0% +minus1 c k - + + + align:start position:0% +minus1 c k - +1+ r k - a half all over + + align:start position:0% +1+ r k - a half all over + + + align:start position:0% +1+ r k - a half all over +K all right so now we' got an expression + + align:start position:0% +K all right so now we' got an expression + + + align:start position:0% +K all right so now we' got an expression +a recursive expression for + + align:start position:0% + + + + align:start position:0% + +CK and to simplify it we're going to + + align:start position:0% +CK and to simplify it we're going to + + + align:start position:0% +CK and to simplify it we're going to +plug in that CK as rk+ one for the + + align:start position:0% +plug in that CK as rk+ one for the + + + align:start position:0% +plug in that CK as rk+ one for the +greedy strategy + + align:start position:0% + + + + align:start position:0% + +yeah L is one the length of the blocks + + align:start position:0% +yeah L is one the length of the blocks + + + align:start position:0% +yeah L is one the length of the blocks +is one here all right to make it simpler + + align:start position:0% +is one here all right to make it simpler + + + align:start position:0% +is one here all right to make it simpler +otherwise it would have been a half l so + + align:start position:0% +otherwise it would have been a half l so + + + align:start position:0% +otherwise it would have been a half l so +yesterday we talked about length L + + align:start position:0% +yesterday we talked about length L + + + align:start position:0% +yesterday we talked about length L +blocks today they're length one to be + + align:start position:0% +blocks today they're length one to be + + + align:start position:0% +blocks today they're length one to be +simple all right so now for the greedy + + align:start position:0% +simple all right so now for the greedy + + + align:start position:0% +simple all right so now for the greedy +strategy I'm just going to plug in CK as + + align:start position:0% +strategy I'm just going to plug in CK as + + + align:start position:0% +strategy I'm just going to plug in CK as +RK + one so let's do + + align:start position:0% +RK + one so let's do + + + align:start position:0% +RK + one so let's do +that so I got CK is RK + 1 + + align:start position:0% + + + + align:start position:0% + +equals uh K minus one well CK minus one + + align:start position:0% +equals uh K minus one well CK minus one + + + align:start position:0% +equals uh K minus one well CK minus one +is just RK + + align:start position:0% + + + + align:start position:0% + +plus rkus a + + align:start position:0% +plus rkus a + + + align:start position:0% +plus rkus a +half over K and this simplifies to K + + align:start position:0% +half over K and this simplifies to K + + + align:start position:0% +half over K and this simplifies to K +RK minus RK plus RK they cancel minus a + + align:start position:0% +RK minus RK plus RK they cancel minus a + + + align:start position:0% +RK minus RK plus RK they cancel minus a +half over + + align:start position:0% +half over + + + align:start position:0% +half over +K this equals RK minus a half so getting + + align:start position:0% +K this equals RK minus a half so getting + + + align:start position:0% +K this equals RK minus a half so getting +very simple + + align:start position:0% +very simple + + + align:start position:0% +very simple +now and I'm just going to rewrite this + + align:start position:0% +now and I'm just going to rewrite this + + + align:start position:0% +now and I'm just going to rewrite this +to look at the difference between RK and + + align:start position:0% +to look at the difference between RK and + + + align:start position:0% +to look at the difference between RK and +RK + 1 so RK minus RK + + + align:start position:0% +RK + 1 so RK minus RK + + + + align:start position:0% +RK + 1 so RK minus RK + +1 oops I made a mistake that's 1 over 2K + + align:start position:0% +1 oops I made a mistake that's 1 over 2K + + + align:start position:0% +1 oops I made a mistake that's 1 over 2K +half over K is 1 over + + align:start position:0% + + + + align:start position:0% + +2K any questions about the math we + + align:start position:0% +2K any questions about the math we + + + align:start position:0% +2K any questions about the math we +did interesting this is one of those + + align:start position:0% +did interesting this is one of those + + + align:start position:0% +did interesting this is one of those +problems where the math this way is easy + + align:start position:0% +problems where the math this way is easy + + + align:start position:0% +problems where the math this way is easy +there are other ways to try to solve + + align:start position:0% +there are other ways to try to solve + + + align:start position:0% +there are other ways to try to solve +this problem the math gets pretty hairy + + align:start position:0% +this problem the math gets pretty hairy + + + align:start position:0% +this problem the math gets pretty hairy +uh but this one's a a simple + + align:start position:0% +uh but this one's a a simple + + + align:start position:0% +uh but this one's a a simple +approach what's the meaning of this + + align:start position:0% +approach what's the meaning of this + + + align:start position:0% +approach what's the meaning of this +what's an interpretation of RK minus RK + + align:start position:0% +what's an interpretation of RK minus RK + + + align:start position:0% +what's an interpretation of RK minus RK +plus + + align:start position:0% +plus + + + align:start position:0% +plus +one + + align:start position:0% + + + + align:start position:0% + +yeah yeah this is how much further the K + + align:start position:0% +yeah yeah this is how much further the K + + + align:start position:0% +yeah yeah this is how much further the K +block sticks out over the K plus first + + align:start position:0% +block sticks out over the K plus first + + + align:start position:0% +block sticks out over the K plus first +block so let's see + + align:start position:0% +block so let's see + + + align:start position:0% +block so let's see +that right so here's R1 here's R2 R1 + + align:start position:0% +that right so here's R1 here's R2 R1 + + + align:start position:0% +that right so here's R1 here's R2 R1 +minus R2 is the the amount by which the + + align:start position:0% +minus R2 is the the amount by which the + + + align:start position:0% +minus R2 is the the amount by which the +first block sticks out over the second + + align:start position:0% +first block sticks out over the second + + + align:start position:0% +first block sticks out over the second +here's R2 minus R3 it's that + + align:start position:0% +here's R2 minus R3 it's that + + + align:start position:0% +here's R2 minus R3 it's that +distance all right so we've gotten a + + align:start position:0% +distance all right so we've gotten a + + + align:start position:0% +distance all right so we've gotten a +formula for the greedy + + align:start position:0% +formula for the greedy + + + align:start position:0% +formula for the greedy +strategy of how much the Ki block sticks + + align:start position:0% +strategy of how much the Ki block sticks + + + align:start position:0% +strategy of how much the Ki block sticks +out over the K plus first block and it's + + align:start position:0% +out over the K plus first block and it's + + + align:start position:0% +out over the K plus first block and it's +pretty simple all right so now we can + + align:start position:0% +pretty simple all right so now we can + + + align:start position:0% +pretty simple all right so now we can +write + + align:start position:0% +write + + + align:start position:0% +write +down this expression for all the values + + align:start position:0% +down this expression for all the values + + + align:start position:0% +down this expression for all the values +of K so what's R1 minus R2 going to be + + align:start position:0% +of K so what's R1 minus R2 going to be + + + align:start position:0% +of K so what's R1 minus R2 going to be +in the greedy strategy how much is the + + align:start position:0% +in the greedy strategy how much is the + + + align:start position:0% +in the greedy strategy how much is the +top block sticking out over the second + + align:start position:0% +top block sticking out over the second + + + align:start position:0% +top block sticking out over the second +Block in the greedy + + align:start position:0% +Block in the greedy + + + align:start position:0% +Block in the greedy +Strat 1 12 just plug in K = + + align:start position:0% +Strat 1 12 just plug in K = + + + align:start position:0% +Strat 1 12 just plug in K = +1 R2 - R3 + + align:start position:0% +1 R2 - R3 + + + align:start position:0% +1 R2 - R3 +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] += qu quarter one quter R3 - + + align:start position:0% += qu quarter one quter R3 - + + + align:start position:0% += qu quarter one quter R3 - +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +R4 is what a six all right so now you + + align:start position:0% +R4 is what a six all right so now you + + + align:start position:0% +R4 is what a six all right so now you +can start to see what the T did how it + + align:start position:0% +can start to see what the T did how it + + + align:start position:0% +can start to see what the T did how it +got smaller each step going down all the + + align:start position:0% +got smaller each step going down all the + + + align:start position:0% +got smaller each step going down all the +way to the end here you get + + align:start position:0% +way to the end here you get + + + align:start position:0% +way to the end here you get +RN the nth block minus the the + + align:start position:0% +RN the nth block minus the the + + + align:start position:0% +RN the nth block minus the the +table is 1 over 2 + + align:start position:0% +table is 1 over 2 + + + align:start position:0% +table is 1 over 2 +N all right now there's a very easy way + + align:start position:0% +N all right now there's a very easy way + + + align:start position:0% +N all right now there's a very easy way +to figure out what R1 + + align:start position:0% +to figure out what R1 + + + align:start position:0% +to figure out what R1 +is which is what we're after how far out + + align:start position:0% +is which is what we're after how far out + + + align:start position:0% +is which is what we're after how far out +of the top block what do I + + align:start position:0% +of the top block what do I + + + align:start position:0% +of the top block what do I +do add them all + + align:start position:0% +do add them all + + + align:start position:0% +do add them all +together and and everything + + align:start position:0% +together and and everything + + + align:start position:0% +together and and everything +cancels so I get R1 - r n + 1 + + align:start position:0% +cancels so I get R1 - r n + 1 + + + align:start position:0% +cancels so I get R1 - r n + 1 +equals a half plus A4 plus a + + align:start position:0% +equals a half plus A4 plus a + + + align:start position:0% +equals a half plus A4 plus a +6 out to 1 over 2 + + align:start position:0% + + + + align:start position:0% + +N all right so that's just equal to the + + align:start position:0% +N all right so that's just equal to the + + + align:start position:0% +N all right so that's just equal to the +sum I = 1 to n 1 over 2 + + align:start position:0% +sum I = 1 to n 1 over 2 + + + align:start position:0% +sum I = 1 to n 1 over 2 +I all right + + align:start position:0% +I all right + + + align:start position:0% +I all right +now I got R1 RN + 1 but what's RN + + align:start position:0% +now I got R1 RN + 1 but what's RN + + + align:start position:0% +now I got R1 RN + 1 but what's RN +plus1 zero that's the table the table + + align:start position:0% +plus1 zero that's the table the table + + + align:start position:0% +plus1 zero that's the table the table +doesn't hang out over itself so in fact + + align:start position:0% + + + + align:start position:0% + +R1 equals a half of the + + align:start position:0% +R1 equals a half of the + + + align:start position:0% +R1 equals a half of the +sum of the inverses of the first and + + align:start position:0% + + + + align:start position:0% + +integers okay and so now alls we have to + + align:start position:0% +integers okay and so now alls we have to + + + align:start position:0% +integers okay and so now alls we have to +do is to compute this sum to know how + + align:start position:0% +do is to compute this sum to know how + + + align:start position:0% +do is to compute this sum to know how +far out it is uh in fact this sum comes + + align:start position:0% +far out it is uh in fact this sum comes + + + align:start position:0% +far out it is uh in fact this sum comes +up so often in mathematics and computer + + align:start position:0% +up so often in mathematics and computer + + + align:start position:0% +up so often in mathematics and computer +science that it has a special name it's + + align:start position:0% +science that it has a special name it's + + + align:start position:0% +science that it has a special name it's +called the harmonic sum and the numbers + + align:start position:0% +called the harmonic sum and the numbers + + + align:start position:0% +called the harmonic sum and the numbers +are called the harmonic numbers and in + + align:start position:0% +are called the harmonic numbers and in + + + align:start position:0% +are called the harmonic numbers and in +particular the nth harmonic + + align:start position:0% + + + + align:start position:0% + +number is typically denoted + + align:start position:0% +number is typically denoted + + + align:start position:0% +number is typically denoted +hn just equals the sum of the first n + + align:start position:0% +hn just equals the sum of the first n + + + align:start position:0% +hn just equals the sum of the first n +reciprocals + + align:start position:0% + + + + align:start position:0% + +all right so for example the first + + align:start position:0% +all right so for example the first + + + align:start position:0% +all right so for example the first +harmonic number is one the second is 1+ + + align:start position:0% +harmonic number is one the second is 1+ + + + align:start position:0% +harmonic number is one the second is 1+ +a half = + + align:start position:0% +a half = + + + align:start position:0% +a half = +3es the 3 is 3es plus a + + align:start position:0% +3es the 3 is 3es plus a + + + align:start position:0% +3es the 3 is 3es plus a +3 which + + align:start position:0% +3 which + + + align:start position:0% +3 which +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +is + + align:start position:0% +is + + + align:start position:0% +is +116 the fourth harmonic number is that + + align:start position:0% +116 the fourth harmonic number is that + + + align:start position:0% +116 the fourth harmonic number is that +plus a + + align:start position:0% +plus a + + + align:start position:0% +plus a +quarter 22+ 3 12th is 25 + + align:start position:0% +quarter 22+ 3 12th is 25 + + + align:start position:0% +quarter 22+ 3 12th is 25 +12ths that's sort of an interesting + + align:start position:0% +12ths that's sort of an interesting + + + align:start position:0% +12ths that's sort of an interesting +number because it's bigger than + + align:start position:0% +number because it's bigger than + + + align:start position:0% +number because it's bigger than +two what does that tell + + align:start position:0% +two what does that tell + + + align:start position:0% +two what does that tell +us why is that interesting from this + + align:start position:0% +us why is that interesting from this + + + align:start position:0% +us why is that interesting from this +perspective what we're doing + + align:start position:0% +perspective what we're doing + + + align:start position:0% +perspective what we're doing +here now you can get a block off the + + align:start position:0% +here now you can get a block off the + + + align:start position:0% +here now you can get a block off the +table because R1 the distance that the + + align:start position:0% +table because R1 the distance that the + + + align:start position:0% +table because R1 the distance that the +top block hangs out off the table is + + align:start position:0% +top block hangs out off the table is + + + align:start position:0% +top block hangs out off the table is +half the harmonic number half of H4 is a + + align:start position:0% +half the harmonic number half of H4 is a + + + align:start position:0% +half the harmonic number half of H4 is a +little bit bigger than one which means + + align:start position:0% +little bit bigger than one which means + + + align:start position:0% +little bit bigger than one which means +means with four blocks the top block can + + align:start position:0% +means with four blocks the top block can + + + align:start position:0% +means with four blocks the top block can +be off the table now the T did it using + + align:start position:0% +be off the table now the T did it using + + + align:start position:0% +be off the table now the T did it using +five I didn't even get it to work with + + align:start position:0% +five I didn't even get it to work with + + + align:start position:0% +five I didn't even get it to work with +five in theory it'll work with 12 you + + align:start position:0% +five in theory it'll work with 12 you + + + align:start position:0% +five in theory it'll work with 12 you +can hang one out there just a 24th + + align:start position:0% +can hang one out there just a 24th + + + align:start position:0% +can hang one out there just a 24th +Beyond the Edge of the table in + + align:start position:0% +Beyond the Edge of the table in + + + align:start position:0% +Beyond the Edge of the table in +theory all right if we kept on + + align:start position:0% +theory all right if we kept on + + + align:start position:0% +theory all right if we kept on +going h of a million the million tonic + + align:start position:0% +going h of a million the million tonic + + + align:start position:0% +going h of a million the million tonic +number if you were to go comput it is + + align:start position:0% +number if you were to go comput it is + + + align:start position:0% +number if you were to go comput it is +14392 7 and some other stuff + + align:start position:0% +14392 7 and some other stuff + + + align:start position:0% +14392 7 and some other stuff +so if I had a million blocks stacked up + + align:start position:0% +so if I had a million blocks stacked up + + + align:start position:0% +so if I had a million blocks stacked up +in theory how far would I get the top + + align:start position:0% +in theory how far would I get the top + + + align:start position:0% +in theory how far would I get the top +block out off the + + align:start position:0% +block out off the + + + align:start position:0% +block out off the +table seven blocks all right so that + + align:start position:0% +table seven blocks all right so that + + + align:start position:0% +table seven blocks all right so that +gives you an idea you got to do a lot of + + align:start position:0% +gives you an idea you got to do a lot of + + + align:start position:0% +gives you an idea you got to do a lot of +work to get seven um and in fact it's + + align:start position:0% +work to get seven um and in fact it's + + + align:start position:0% +work to get seven um and in fact it's +hard because the bottom block would be + + align:start position:0% +hard because the bottom block would be + + + align:start position:0% +hard because the bottom block would be +hanging out one two millionth of a block + + align:start position:0% +hanging out one two millionth of a block + + + align:start position:0% +hanging out one two millionth of a block +right so you're adding up a lot of tiny + + align:start position:0% +right so you're adding up a lot of tiny + + + align:start position:0% +right so you're adding up a lot of tiny +things to get to Seven out + + align:start position:0% +things to get to Seven out + + + align:start position:0% +things to get to Seven out +there now it turns out that the harmonic + + align:start position:0% +there now it turns out that the harmonic + + + align:start position:0% +there now it turns out that the harmonic +numbers grow to Infinity + + align:start position:0% +numbers grow to Infinity + + + align:start position:0% +numbers grow to Infinity +and we'll see that but they grow very + + align:start position:0% +and we'll see that but they grow very + + + align:start position:0% +and we'll see that but they grow very +very + + align:start position:0% +very + + + align:start position:0% +very +slowly uh and to see that we need to get + + align:start position:0% +slowly uh and to see that we need to get + + + align:start position:0% +slowly uh and to see that we need to get +a closed form expression for this + + align:start position:0% +a closed form expression for this + + + align:start position:0% +a closed form expression for this +sum now does anybody know a closed form + + align:start position:0% +sum now does anybody know a closed form + + + align:start position:0% +sum now does anybody know a closed form +expression for the sum of 1 over + + align:start position:0% +expression for the sum of 1 over + + + align:start position:0% +expression for the sum of 1 over +I I don't think so because I don't I + + align:start position:0% +I I don't think so because I don't I + + + align:start position:0% +I I don't think so because I don't I +don't know I don't know anybody who + + align:start position:0% +don't know I don't know anybody who + + + align:start position:0% +don't know I don't know anybody who +knows + + align:start position:0% +knows + + + align:start position:0% +knows +that uh in fact it's probably believed + + align:start position:0% +that uh in fact it's probably believed + + + align:start position:0% +that uh in fact it's probably believed +that it doesn't + + align:start position:0% +that it doesn't + + + align:start position:0% +that it doesn't +exist so what do we do to get a good + + align:start position:0% +exist so what do we do to get a good + + + align:start position:0% +exist so what do we do to get a good +estimation of that + + align:start position:0% + + + + align:start position:0% + +sum what do we do integration bounds + + align:start position:0% +sum what do we do integration bounds + + + align:start position:0% +sum what do we do integration bounds +integration bounds yeah because we're + + align:start position:0% +integration bounds yeah because we're + + + align:start position:0% +integration bounds yeah because we're +not going to get a closed form at least + + align:start position:0% +not going to get a closed form at least + + + align:start position:0% +not going to get a closed form at least +I don't know if anybody who knows how to + + align:start position:0% +I don't know if anybody who knows how to + + + align:start position:0% +I don't know if anybody who knows how to +do it uh so we'll use the integration + + align:start position:0% + + + + align:start position:0% + +bounds and what kind of function are we + + align:start position:0% +bounds and what kind of function are we + + + align:start position:0% +bounds and what kind of function are we +summing is it increasing or + + align:start position:0% +summing is it increasing or + + + align:start position:0% +summing is it increasing or +decreasing decreasing + + align:start position:0% +decreasing decreasing + + + align:start position:0% +decreasing decreasing +yeah so we use the formula we did last + + align:start position:0% + + + + align:start position:0% + +time all right and that formula is that + + align:start position:0% +time all right and that formula is that + + + align:start position:0% +time all right and that formula is that +the sum I = 1 to + + align:start position:0% +the sum I = 1 to + + + align:start position:0% +the sum I = 1 to +n of f of + + align:start position:0% +n of f of + + + align:start position:0% +n of f of +I is at most the first term plus the + + align:start position:0% +I is at most the first term plus the + + + align:start position:0% +I is at most the first term plus the +integral + + align:start position:0% + + + + align:start position:0% + +and it's at least the last term plus the + + align:start position:0% + + + + align:start position:0% + +integral all right in this case we have + + align:start position:0% +integral all right in this case we have + + + align:start position:0% +integral all right in this case we have +F of I is 1 over + + align:start position:0% + + + + align:start position:0% + +I so the first step is to compute the + + align:start position:0% +I so the first step is to compute the + + + align:start position:0% +I so the first step is to compute the +integral + + align:start position:0% + + + + align:start position:0% + +and that's pretty easy that's just the + + align:start position:0% +and that's pretty easy that's just the + + + align:start position:0% +and that's pretty easy that's just the +natural log of + + align:start position:0% +natural log of + + + align:start position:0% +natural log of +x evaluated at n and one and that's easy + + align:start position:0% +x evaluated at n and one and that's easy + + + align:start position:0% +x evaluated at n and one and that's easy +that's just a natural log of + + align:start position:0% +that's just a natural log of + + + align:start position:0% +that's just a natural log of +n so the integral is very easy here and + + align:start position:0% +n so the integral is very easy here and + + + align:start position:0% +n so the integral is very easy here and +now we actually can just plug in and get + + align:start position:0% +now we actually can just plug in and get + + + align:start position:0% +now we actually can just plug in and get +really good + + align:start position:0% +really good + + + align:start position:0% +really good +bounds um maybe I'll save that just in + + align:start position:0% +bounds um maybe I'll save that just in + + + align:start position:0% +bounds um maybe I'll save that just in +case + + align:start position:0% + + + + align:start position:0% + +okay so plugging in into the bounds F of + + align:start position:0% +okay so plugging in into the bounds F of + + + align:start position:0% +okay so plugging in into the bounds F of +n is 1 / + + align:start position:0% +n is 1 / + + + align:start position:0% +n is 1 / +n plus the integral is log of n is less + + align:start position:0% +n plus the integral is log of n is less + + + align:start position:0% +n plus the integral is log of n is less +than or equal to the nth harmonic number + + align:start position:0% +than or equal to the nth harmonic number + + + align:start position:0% +than or equal to the nth harmonic number +and it's upper bounded by F of one which + + align:start position:0% +and it's upper bounded by F of one which + + + align:start position:0% +and it's upper bounded by F of one which +is one + + align:start position:0% +is one + + + align:start position:0% +is one +plus the + + align:start position:0% +plus the + + + align:start position:0% +plus the +integral all right so that's really good + + align:start position:0% +integral all right so that's really good + + + align:start position:0% +integral all right so that's really good +we got very tight bounds and now you can + + align:start position:0% +we got very tight bounds and now you can + + + align:start position:0% +we got very tight bounds and now you can +see that the nth harmonic number how + + align:start position:0% +see that the nth harmonic number how + + + align:start position:0% +see that the nth harmonic number how +fast is it growing if I were to use + + align:start position:0% +fast is it growing if I were to use + + + align:start position:0% +fast is it growing if I were to use +Tilda notation what would I + + align:start position:0% +Tilda notation what would I + + + align:start position:0% +Tilda notation what would I +write as log n yeah so this means that h + + align:start position:0% +write as log n yeah so this means that h + + + align:start position:0% +write as log n yeah so this means that h +of n is Tilda log of + + align:start position:0% +of n is Tilda log of + + + align:start position:0% +of n is Tilda log of +n okay now this is such an important + + align:start position:0% +n okay now this is such an important + + + align:start position:0% +n okay now this is such an important +function that people have gone to a lot + + align:start position:0% +function that people have gone to a lot + + + align:start position:0% +function that people have gone to a lot +of extra work which we can't do in this + + align:start position:0% +of extra work which we can't do in this + + + align:start position:0% +of extra work which we can't do in this +class um to really nail down the value + + align:start position:0% +class um to really nail down the value + + + align:start position:0% +class um to really nail down the value +get it much closer and in + + align:start position:0% +get it much closer and in + + + align:start position:0% +get it much closer and in +fact it's now known that it's the + + align:start position:0% +fact it's now known that it's the + + + align:start position:0% +fact it's now known that it's the +natural log of n + 1 over 2 + + align:start position:0% +natural log of n + 1 over 2 + + + align:start position:0% +natural log of n + 1 over 2 +n + 1 over 12 + + align:start position:0% +n + 1 over 12 + + + align:start position:0% +n + 1 over 12 +n^2 plus Epsilon of n over 120 n + + align:start position:0% +n^2 plus Epsilon of n over 120 n + + + align:start position:0% +n^2 plus Epsilon of n over 120 n + + align:start position:0% + + + + align:start position:0% + +where for all n Epsilon n is between + + align:start position:0% +where for all n Epsilon n is between + + + align:start position:0% +where for all n Epsilon n is between +zero and + + align:start position:0% + + + + align:start position:0% + +one oh and I laugh lost left one piece + + align:start position:0% +one oh and I laugh lost left one piece + + + align:start position:0% +one oh and I laugh lost left one piece +out actually there's a constant term in + + align:start position:0% +out actually there's a constant term in + + + align:start position:0% +out actually there's a constant term in +here Delta that's called Oiler + + align:start position:0% +here Delta that's called Oiler + + + align:start position:0% +here Delta that's called Oiler +constant all right + + align:start position:0% +constant all right + + + align:start position:0% +constant all right +Delta is called Oiler + + align:start position:0% +Delta is called Oiler + + + align:start position:0% +Delta is called Oiler +constant and + + align:start position:0% +constant and + + + align:start position:0% +constant and +equals + + align:start position:0% +equals + + + align:start position:0% +equals +0.577 21 + + align:start position:0% +0.577 21 + + + align:start position:0% +0.577 21 + + align:start position:0% + + + align:start position:0% +664 and some other stuff and in fact to + + align:start position:0% +664 and some other stuff and in fact to + + + align:start position:0% +664 and some other stuff and in fact to +this day people don't know if this + + align:start position:0% +this day people don't know if this + + + align:start position:0% +this day people don't know if this +constant is rational or + + align:start position:0% +constant is rational or + + + align:start position:0% +constant is rational or +irrational but they know it to a lot of + + align:start position:0% +irrational but they know it to a lot of + + + align:start position:0% +irrational but they know it to a lot of +decimal + + align:start position:0% +decimal + + + align:start position:0% +decimal +places uh so basically hn is the log of + + align:start position:0% +places uh so basically hn is the log of + + + align:start position:0% +places uh so basically hn is the log of +n plus some fixed value between zero and + + align:start position:0% +n plus some fixed value between zero and + + + align:start position:0% +n plus some fixed value between zero and +one as we knew it had to be plus even + + align:start position:0% +one as we knew it had to be plus even + + + align:start position:0% +one as we knew it had to be plus even +some tail terms here that get very small + + align:start position:0% +some tail terms here that get very small + + + align:start position:0% +some tail terms here that get very small +as n gets + + align:start position:0% +as n gets + + + align:start position:0% +as n gets +large all right so say I wanted to know + + align:start position:0% +large all right so say I wanted to know + + + align:start position:0% +large all right so say I wanted to know +using this greedy strategy how many + + align:start position:0% +using this greedy strategy how many + + + align:start position:0% +using this greedy strategy how many +blocks I would need to get a block a + + align:start position:0% +blocks I would need to get a block a + + + align:start position:0% +blocks I would need to get a block a +hundred blocks out over the end of the + + align:start position:0% +hundred blocks out over the end of the + + + align:start position:0% +hundred blocks out over the end of the +table so I want to go a 100 blocks out + + align:start position:0% +table so I want to go a 100 blocks out + + + align:start position:0% +table so I want to go a 100 blocks out +how many blocks do I need using this + + align:start position:0% +how many blocks do I need using this + + + align:start position:0% +how many blocks do I need using this +strategy + + align:start position:0% + + + + align:start position:0% + +roughly what is + + align:start position:0% +roughly what is + + + align:start position:0% +roughly what is +it think somebody said + + align:start position:0% +it think somebody said + + + align:start position:0% +it think somebody said +it so I want to + + align:start position:0% +it so I want to + + + align:start position:0% +it so I want to +get R1 to be 100 + + align:start position:0% + + + + align:start position:0% + +so I need the harmonic number to be + + align:start position:0% +so I need the harmonic number to be + + + align:start position:0% +so I need the harmonic number to be +200 and what does this tell me about n + + align:start position:0% +200 and what does this tell me about n + + + align:start position:0% +200 and what does this tell me about n +to get this to be + + align:start position:0% + + + + align:start position:0% + +200 e to the 200 right so you're going + + align:start position:0% +200 e to the 200 right so you're going + + + align:start position:0% +200 e to the 200 right so you're going +to need an exponential in 200 number of + + align:start position:0% +to need an exponential in 200 number of + + + align:start position:0% +to need an exponential in 200 number of +blocks which now we're past the Stars + + align:start position:0% +blocks which now we're past the Stars + + + align:start position:0% +blocks which now we're past the Stars +right to get that many right all right + + align:start position:0% +right to get that many right all right + + + align:start position:0% +right to get that many right all right +now we won't prove it in class but this + + align:start position:0% +now we won't prove it in class but this + + + align:start position:0% +now we won't prove it in class but this +strategy the TA greedy strategy is + + align:start position:0% +strategy the TA greedy strategy is + + + align:start position:0% +strategy the TA greedy strategy is +optimal there is no way to get a block + + align:start position:0% +optimal there is no way to get a block + + + align:start position:0% +optimal there is no way to get a block +farther out over the + + align:start position:0% +farther out over the + + + align:start position:0% +farther out over the +edge uh that said there is a second way + + align:start position:0% +edge uh that said there is a second way + + + align:start position:0% +edge uh that said there is a second way +to get there and in the second way the + + align:start position:0% +to get there and in the second way the + + + align:start position:0% +to get there and in the second way the +top block is not the optimal Block in + + align:start position:0% +top block is not the optimal Block in + + + align:start position:0% +top block is not the optimal Block in +the second way it's the second block + + align:start position:0% +the second way it's the second block + + + align:start position:0% +the second way it's the second block +that goes out so it looks something like + + align:start position:0% +that goes out so it looks something like + + + align:start position:0% +that goes out so it looks something like +that so there's a counterweight on it + + align:start position:0% +that so there's a counterweight on it + + + align:start position:0% +that so there's a counterweight on it +and in the text when you read chapter 9 + + align:start position:0% +and in the text when you read chapter 9 + + + align:start position:0% +and in the text when you read chapter 9 +you will see the proof that shows that + + align:start position:0% +you will see the proof that shows that + + + align:start position:0% +you will see the proof that shows that +there's two solutions that are optimal + + align:start position:0% +there's two solutions that are optimal + + + align:start position:0% +there's two solutions that are optimal +one's the greedy and one's this other + + align:start position:0% +one's the greedy and one's this other + + + align:start position:0% +one's the greedy and one's this other +one that sort of is mostly the greedy + + align:start position:0% +one that sort of is mostly the greedy + + + align:start position:0% +one that sort of is mostly the greedy +except the top couple of blocks are + + align:start position:0% +except the top couple of blocks are + + + align:start position:0% +except the top couple of blocks are +different and it proves that's optimal + + align:start position:0% +different and it proves that's optimal + + + align:start position:0% +different and it proves that's optimal +we won't we won't cover that in + + align:start position:0% +we won't we won't cover that in + + + align:start position:0% +we won't we won't cover that in +class uh now actually in the literature + + align:start position:0% +class uh now actually in the literature + + + align:start position:0% +class uh now actually in the literature +today people have been studying how far + + align:start position:0% +today people have been studying how far + + + align:start position:0% +today people have been studying how far +a block can go out if you're allowed to + + align:start position:0% +a block can go out if you're allowed to + + + align:start position:0% +a block can go out if you're allowed to +do more than one block per level like + + align:start position:0% +do more than one block per level like + + + align:start position:0% +do more than one block per level like +one of the students wanted to do so if + + align:start position:0% +one of the students wanted to do so if + + + align:start position:0% +one of the students wanted to do so if +you're allowed to have multiple blocks + + align:start position:0% +you're allowed to have multiple blocks + + + align:start position:0% +you're allowed to have multiple blocks +on the same level it turns out you can + + align:start position:0% +on the same level it turns out you can + + + align:start position:0% +on the same level it turns out you can +get much farther out then blocks and + + align:start position:0% +get much farther out then blocks and + + + align:start position:0% +get much farther out then blocks and +right now it's known that it's uh + + align:start position:0% +right now it's known that it's uh + + + align:start position:0% +right now it's known that it's uh +something like n the3 is how far you can + + align:start position:0% +something like n the3 is how far you can + + + align:start position:0% +something like n the3 is how far you can +get out which is much better than log of + + align:start position:0% +get out which is much better than log of + + + align:start position:0% +get out which is much better than log of +N and so mathematicians have been + + align:start position:0% +N and so mathematicians have been + + + align:start position:0% +N and so mathematicians have been +studying that + + align:start position:0% +studying that + + + align:start position:0% +studying that +problem any + + align:start position:0% +problem any + + + align:start position:0% +problem any +questions about the block + + align:start position:0% + + + + align:start position:0% + +stacking okay all right so um that's + + align:start position:0% +stacking okay all right so um that's + + + align:start position:0% +stacking okay all right so um that's +basically it for sums I do want to spend + + align:start position:0% +basically it for sums I do want to spend + + + align:start position:0% +basically it for sums I do want to spend +a little time talking about products and + + align:start position:0% +a little time talking about products and + + + align:start position:0% +a little time talking about products and +that may get us back into sums pretty + + align:start position:0% +that may get us back into sums pretty + + + align:start position:0% +that may get us back into sums pretty +quick + + align:start position:0% +quick + + + align:start position:0% +quick +um the most famous product out there is + + align:start position:0% +um the most famous product out there is + + + align:start position:0% +um the most famous product out there is +n + + align:start position:0% +n + + + align:start position:0% +n +factorial and once we get to counting + + align:start position:0% +factorial and once we get to counting + + + align:start position:0% +factorial and once we get to counting +and probability probably every lecture + + align:start position:0% +and probability probably every lecture + + + align:start position:0% +and probability probably every lecture +we're going to be looking at n factorial + + align:start position:0% +we're going to be looking at n factorial + + + align:start position:0% +we're going to be looking at n factorial +one way or another just comes up all the + + align:start position:0% +one way or another just comes up all the + + + align:start position:0% +one way or another just comes up all the +time n factorial is the + + align:start position:0% +time n factorial is the + + + align:start position:0% +time n factorial is the +product of I = 1 to n of I it's the + + align:start position:0% +product of I = 1 to n of I it's the + + + align:start position:0% +product of I = 1 to n of I it's the +product of the first n now natural + + align:start position:0% +product of the first n now natural + + + align:start position:0% +product of the first n now natural +numbers after + + align:start position:0% +numbers after + + + align:start position:0% +numbers after +zero now we'd like to be able to get a + + align:start position:0% +zero now we'd like to be able to get a + + + align:start position:0% +zero now we'd like to be able to get a +closed form expression for this because + + align:start position:0% +closed form expression for this because + + + align:start position:0% +closed form expression for this because +factorial is really not closed form + + align:start position:0% +factorial is really not closed form + + + align:start position:0% +factorial is really not closed form +because it's it's hiding this + + align:start position:0% +because it's it's hiding this + + + align:start position:0% +because it's it's hiding this +thing and if I ask you how big is n + + align:start position:0% +thing and if I ask you how big is n + + + align:start position:0% +thing and if I ask you how big is n +factorial sort of hard to to say how big + + align:start position:0% +factorial sort of hard to to say how big + + + align:start position:0% +factorial sort of hard to to say how big +it is how fast it + + align:start position:0% +it is how fast it + + + align:start position:0% +it is how fast it +grows any ideas about how we might go + + align:start position:0% +grows any ideas about how we might go + + + align:start position:0% +grows any ideas about how we might go +about doing a + + align:start position:0% +about doing a + + + align:start position:0% +about doing a +product to get a closed form expression + + align:start position:0% +product to get a closed form expression + + + align:start position:0% +product to get a closed form expression +yeah LM of a product you get a sum yeah + + align:start position:0% +yeah LM of a product you get a sum yeah + + + align:start position:0% +yeah LM of a product you get a sum yeah +good take the log of + + align:start position:0% + + + + align:start position:0% + +it well that's just let's write that out + + align:start position:0% +it well that's just let's write that out + + + align:start position:0% +it well that's just let's write that out +1 * 2 * 3 to n that equals the log of + + align:start position:0% +1 * 2 * 3 to n that equals the log of + + + align:start position:0% +1 * 2 * 3 to n that equals the log of +one plus the log of + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% + + + + align:start position:0% + +whoops all right so I've now got a sum + + align:start position:0% + + + + align:start position:0% + +and now that I got a sum we can use all + + align:start position:0% +and now that I got a sum we can use all + + + align:start position:0% +and now that I got a sum we can use all +the tools we had for sums so really + + align:start position:0% +the tools we had for sums so really + + + align:start position:0% +the tools we had for sums so really +products look hairy but they're no + + align:start position:0% +products look hairy but they're no + + + align:start position:0% +products look hairy but they're no +different than sums because we're going + + align:start position:0% +different than sums because we're going + + + align:start position:0% +different than sums because we're going +to get an approximation or get an answer + + align:start position:0% +to get an approximation or get an answer + + + align:start position:0% +to get an approximation or get an answer +for log of n factorial then we'll + + align:start position:0% +for log of n factorial then we'll + + + align:start position:0% +for log of n factorial then we'll +exponentiate it we'll have the + + align:start position:0% +exponentiate it we'll have the + + + align:start position:0% +exponentiate it we'll have the +answer all right so we're looking at + + align:start position:0% +answer all right so we're looking at + + + align:start position:0% +answer all right so we're looking at +this + + align:start position:0% +this + + + align:start position:0% +this +sum and uh so how do I get a closed form + + align:start position:0% +sum and uh so how do I get a closed form + + + align:start position:0% +sum and uh so how do I get a closed form +for + + align:start position:0% +for + + + align:start position:0% +for +that turns out nobody knows a closed + + align:start position:0% +that turns out nobody knows a closed + + + align:start position:0% +that turns out nobody knows a closed +form but we do know a method that + + align:start position:0% +form but we do know a method that + + + align:start position:0% +form but we do know a method that +approximates it very + + align:start position:0% +approximates it very + + + align:start position:0% +approximates it very +well which is the integration + + align:start position:0% +well which is the integration + + + align:start position:0% +well which is the integration +bounds only in this case it's an + + align:start position:0% +bounds only in this case it's an + + + align:start position:0% +bounds only in this case it's an +increasing + + align:start position:0% +increasing + + + align:start position:0% +increasing +function so let's do that + + align:start position:0% + + + + align:start position:0% + +okay so let's do + + align:start position:0% + + + + align:start position:0% + +that and the formula is easy it's + + align:start position:0% +that and the formula is easy it's + + + align:start position:0% +that and the formula is easy it's +basically the same formula we had there + + align:start position:0% +basically the same formula we had there + + + align:start position:0% +basically the same formula we had there +that the sum + + align:start position:0% +that the sum + + + align:start position:0% +that the sum +I = 1 to n of f of I is at most the nth + + align:start position:0% +I = 1 to n of f of I is at most the nth + + + align:start position:0% +I = 1 to n of f of I is at most the nth +term plus the + + align:start position:0% + + + + align:start position:0% + +integral and it's at least the first + + align:start position:0% +integral and it's at least the first + + + align:start position:0% +integral and it's at least the first +term plus the + + align:start position:0% + + + + align:start position:0% + +integral all right now in this case f of + + align:start position:0% +integral all right now in this case f of + + + align:start position:0% +integral all right now in this case f of +I is the log of + + align:start position:0% + + + + align:start position:0% + +I and so we need to compute the integral + + align:start position:0% + + + + align:start position:0% + +of log of + + align:start position:0% +of log of + + + align:start position:0% +of log of +x and that's easy that's X Ln of x minus + + align:start position:0% +x and that's easy that's X Ln of x minus + + + align:start position:0% +x and that's easy that's X Ln of x minus +X evaluated at n and + + align:start position:0% +X evaluated at n and + + + align:start position:0% +X evaluated at n and +one and that's just NL n log of n minus + + align:start position:0% + + + + align:start position:0% + +n if I plug in one I get a zero here and + + align:start position:0% +n if I plug in one I get a zero here and + + + align:start position:0% +n if I plug in one I get a zero here and +I'm subtracting negative one + + align:start position:0% +I'm subtracting negative one + + + align:start position:0% +I'm subtracting negative one +there all right and so now we'll just + + align:start position:0% +there all right and so now we'll just + + + align:start position:0% +there all right and so now we'll just +plug this into the integral and we'll + + align:start position:0% +plug this into the integral and we'll + + + align:start position:0% +plug this into the integral and we'll +get our + + align:start position:0% + + + + align:start position:0% + +bounce so F of + + align:start position:0% +bounce so F of + + + align:start position:0% +bounce so F of +one what is f of + + align:start position:0% +one what is f of + + + align:start position:0% +one what is f of +one in this + + align:start position:0% +one in this + + + align:start position:0% +one in this +case yeah + + align:start position:0% +case yeah + + + align:start position:0% +case yeah +zero + + align:start position:0% +zero + + + align:start position:0% +zero +plus n + + align:start position:0% +plus n + + + align:start position:0% +plus n +Ln and - n + 1 less than equal + + align:start position:0% +Ln and - n + 1 less than equal + + + align:start position:0% +Ln and - n + 1 less than equal +to log of n factorial + + align:start position:0% +to log of n factorial + + + align:start position:0% +to log of n factorial +or equal to F of n is log of + + align:start position:0% + + + + align:start position:0% + +n okay so to get bounds on N factorial + + align:start position:0% +n okay so to get bounds on N factorial + + + align:start position:0% +n okay so to get bounds on N factorial +we just exponentiate both + + align:start position:0% +we just exponentiate both + + + align:start position:0% +we just exponentiate both +sides so I take e to this gives me well + + align:start position:0% +sides so I take e to this gives me well + + + align:start position:0% +sides so I take e to this gives me well +that's going to + + align:start position:0% +that's going to + + + align:start position:0% +that's going to +give n to the N here and then this is + + align:start position:0% +give n to the N here and then this is + + + align:start position:0% +give n to the N here and then this is +negative that'll be e to the N minus one + + align:start position:0% + + + + align:start position:0% + +and here I've + + align:start position:0% +and here I've + + + align:start position:0% +and here I've +got uh n +1 * the log of n so it's n the + + align:start position:0% +got uh n +1 * the log of n so it's n the + + + align:start position:0% +got uh n +1 * the log of n so it's n the +n + one over the same thing e to the N + + align:start position:0% +n + one over the same thing e to the N + + + align:start position:0% +n + one over the same thing e to the N +minus + + align:start position:0% +minus + + + align:start position:0% +minus +one so we got very close bounds they're + + align:start position:0% +one so we got very close bounds they're + + + align:start position:0% +one so we got very close bounds they're +within a factor of + + align:start position:0% +within a factor of + + + align:start position:0% +within a factor of +n which sounds like a lot but compared + + align:start position:0% +n which sounds like a lot but compared + + + align:start position:0% +n which sounds like a lot but compared +to how big n factorial is not so bad + + align:start position:0% +to how big n factorial is not so bad + + + align:start position:0% +to how big n factorial is not so bad +pretty pretty good bounds + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% +there + + + align:start position:0% +there +okay it's about so n factorial is about + + align:start position:0% +okay it's about so n factorial is about + + + align:start position:0% +okay it's about so n factorial is about +n over e to the N + + align:start position:0% +n over e to the N + + + align:start position:0% +n over e to the N +power now this is so important that that + + align:start position:0% +power now this is so important that that + + + align:start position:0% +power now this is so important that that +even more important than harmonic + + align:start position:0% +even more important than harmonic + + + align:start position:0% +even more important than harmonic +numbers people have gone to a lot of + + align:start position:0% +numbers people have gone to a lot of + + + align:start position:0% +numbers people have gone to a lot of +effort to get very tight bounds on N + + align:start position:0% +effort to get very tight bounds on N + + + align:start position:0% +effort to get very tight bounds on N +factorial so let me tell you what those + + align:start position:0% + + + + align:start position:0% + +are it's called Sterling's formula + + align:start position:0% + + + + align:start position:0% + +and that says that n + + align:start position:0% +and that says that n + + + align:start position:0% +and that says that n +factorial equals n / e to the N Power + + align:start position:0% +factorial equals n / e to the N Power + + + align:start position:0% +factorial equals n / e to the N Power +Times the < TK of 2 piun + + align:start position:0% +Times the < TK of 2 piun + + + align:start position:0% +Times the < TK of 2 piun +N time e to the Epsilon + + align:start position:0% +N time e to the Epsilon + + + align:start position:0% +N time e to the Epsilon +n + + align:start position:0% + + + + align:start position:0% + +where Epsilon n is between 1 over 12 n + + + align:start position:0% +where Epsilon n is between 1 over 12 n + + + + align:start position:0% +where Epsilon n is between 1 over 12 n + + + align:start position:0% + + + align:start position:0% +and 1 over + + align:start position:0% +and 1 over + + + align:start position:0% +and 1 over +12n so it's Epsilon n is going to zero + + align:start position:0% +12n so it's Epsilon n is going to zero + + + align:start position:0% +12n so it's Epsilon n is going to zero +as n gets big so e is something going to + + align:start position:0% +as n gets big so e is something going to + + + align:start position:0% +as n gets big so e is something going to +zero is going to one all right so + + align:start position:0% +zero is going to one all right so + + + align:start position:0% +zero is going to one all right so +another way of looking at this is you + + align:start position:0% +another way of looking at this is you + + + align:start position:0% +another way of looking at this is you +could put a Tilda here all right and + + align:start position:0% +could put a Tilda here all right and + + + align:start position:0% +could put a Tilda here all right and +ignore that term that's called + + align:start position:0% +ignore that term that's called + + + align:start position:0% +ignore that term that's called +Sterling's formula this is a good thing + + align:start position:0% +Sterling's formula this is a good thing + + + align:start position:0% +Sterling's formula this is a good thing +to have on your crib sheet all right for + + align:start position:0% +to have on your crib sheet all right for + + + align:start position:0% +to have on your crib sheet all right for +the midterm so very likely there'll be + + align:start position:0% +the midterm so very likely there'll be + + + align:start position:0% +the midterm so very likely there'll be +something where you got to have some + + align:start position:0% +something where you got to have some + + + align:start position:0% +something where you got to have some +kind of analysis of n factorial and to + + align:start position:0% +kind of analysis of n factorial and to + + + align:start position:0% +kind of analysis of n factorial and to +know how fast it's + + align:start position:0% +know how fast it's + + + align:start position:0% +know how fast it's +growing now this these bounds you get + + align:start position:0% +growing now this these bounds you get + + + align:start position:0% +growing now this these bounds you get +here are very tight for + + align:start position:0% +here are very tight for + + + align:start position:0% +here are very tight for +example 100 + + align:start position:0% +example 100 + + + align:start position:0% +example 100 +factorial is at + + align:start position:0% +factorial is at + + + align:start position:0% +factorial is at +least 100 over e to 100 * < TK 200 + + align:start position:0% +least 100 over e to 100 * < TK 200 + + + align:start position:0% +least 100 over e to 100 * < TK 200 +piun time e to 1 over + + align:start position:0% +piun time e to 1 over + + + align:start position:0% +piun time e to 1 over +1201 this thing is is just really tiny + + align:start position:0% +1201 this thing is is just really tiny + + + align:start position:0% +1201 this thing is is just really tiny +this thing here is + + align:start position:0% +this thing here is + + + align:start position:0% +this thing here is +1.0 + + align:start position:0% +1.0 + + + align:start position:0% +1.0 +8329 and something and 100 factorial is + + align:start position:0% +8329 and something and 100 factorial is + + + align:start position:0% +8329 and something and 100 factorial is +lower + + align:start position:0% +lower + + + align:start position:0% +lower +bounded by the same + + align:start position:0% +bounded by the same + + + align:start position:0% +bounded by the same +things only here it's e to the 1 over + + align:start position:0% + + + + align:start position:0% + +1200 and that is very close to one + + align:start position:0% +1200 and that is very close to one + + + align:start position:0% +1200 and that is very close to one +1.008 33 6 8 so the difference in these + + align:start position:0% +1.008 33 6 8 so the difference in these + + + align:start position:0% +1.008 33 6 8 so the difference in these +bounds is a tiny fraction of + + align:start position:0% +bounds is a tiny fraction of + + + align:start position:0% +bounds is a tiny fraction of +1% so the bound you get from Sterling's + + align:start position:0% +1% so the bound you get from Sterling's + + + align:start position:0% +1% so the bound you get from Sterling's +formula is very very close to the right + + align:start position:0% + + + + align:start position:0% + +answer any + + align:start position:0% +answer any + + + align:start position:0% +answer any +questions on Sterling's formula we won't + + align:start position:0% +questions on Sterling's formula we won't + + + align:start position:0% +questions on Sterling's formula we won't +derive it you can derive that in a + + align:start position:0% +derive it you can derive that in a + + + align:start position:0% +derive it you can derive that in a +graduate math class they do that + + align:start position:0% + + + + align:start position:0% + +sometimes well typically you'll see it + + align:start position:0% +sometimes well typically you'll see it + + + align:start position:0% +sometimes well typically you'll see it +without that e to the error term and you + + align:start position:0% +without that e to the error term and you + + + align:start position:0% +without that e to the error term and you +just see n factorial written as Tilda n + + align:start position:0% +just see n factorial written as Tilda n + + + align:start position:0% +just see n factorial written as Tilda n +/ e to the N < TK 2 piun + + align:start position:0% +/ e to the N < TK 2 piun + + + align:start position:0% +/ e to the N < TK 2 piun +N all right because that e to the + + align:start position:0% +N all right because that e to the + + + align:start position:0% +N all right because that e to the +Epsilon n goes to one in the limit so it + + align:start position:0% +Epsilon n goes to one in the limit so it + + + align:start position:0% +Epsilon n goes to one in the limit so it +sort of disappears when you go to the + + align:start position:0% +sort of disappears when you go to the + + + align:start position:0% +sort of disappears when you go to the +TAA + + align:start position:0% +TAA + + + align:start position:0% +TAA +notation and this in fact is a lower + + align:start position:0% +notation and this in fact is a lower + + + align:start position:0% +notation and this in fact is a lower +bound on N factorial and very close to + + align:start position:0% +bound on N factorial and very close to + + + align:start position:0% +bound on N factorial and very close to +the right + + align:start position:0% +the right + + + align:start position:0% +the right +answer now this is sort of this is sort + + align:start position:0% +answer now this is sort of this is sort + + + align:start position:0% +answer now this is sort of this is sort +of an amazing formula I mean who would + + align:start position:0% +of an amazing formula I mean who would + + + align:start position:0% +of an amazing formula I mean who would +think that when you look at n + + align:start position:0% +think that when you look at n + + + align:start position:0% +think that when you look at n +factorial that the expression would have + + align:start position:0% +factorial that the expression would have + + + align:start position:0% +factorial that the expression would have +e and Pi in the expression for it maybe + + align:start position:0% +e and Pi in the expression for it maybe + + + align:start position:0% +e and Pi in the expression for it maybe +e maybe but what's pi doing in N + + align:start position:0% +e maybe but what's pi doing in N + + + align:start position:0% +e maybe but what's pi doing in N +factorial it's just sort of a bizarre + + align:start position:0% +factorial it's just sort of a bizarre + + + align:start position:0% +factorial it's just sort of a bizarre +thing okay that's it for products we're + + align:start position:0% +thing okay that's it for products we're + + + align:start position:0% +thing okay that's it for products we're +just going to do the one example because + + align:start position:0% +just going to do the one example because + + + align:start position:0% +just going to do the one example because +really any product just becomes a sum + + align:start position:0% +really any product just becomes a sum + + + align:start position:0% +really any product just becomes a sum +through the log and that makes it really + + align:start position:0% +through the log and that makes it really + + + align:start position:0% +through the log and that makes it really +easy any questions on sums and + + align:start position:0% +easy any questions on sums and + + + align:start position:0% +easy any questions on sums and +products I'm I'm going to totally change + + align:start position:0% +products I'm I'm going to totally change + + + align:start position:0% +products I'm I'm going to totally change +gears now and talk about things more + + align:start position:0% +gears now and talk about things more + + + align:start position:0% +gears now and talk about things more +things like + + align:start position:0% + + + + align:start position:0% + +Tilda + + align:start position:0% + + + + align:start position:0% + +okay so we're going to talk today and + + align:start position:0% +okay so we're going to talk today and + + + align:start position:0% +okay so we're going to talk today and +tomorrow and + + align:start position:0% +tomorrow and + + + align:start position:0% +tomorrow and +recitation about asymptotic + + align:start position:0% +recitation about asymptotic + + + align:start position:0% +recitation about asymptotic +notation it is used all over the place + + align:start position:0% +notation it is used all over the place + + + align:start position:0% +notation it is used all over the place +in computer + + align:start position:0% +in computer + + + align:start position:0% +in computer +science we've already seen one example + + align:start position:0% +science we've already seen one example + + + align:start position:0% +science we've already seen one example +which is the tied notation + + align:start position:0% +which is the tied notation + + + align:start position:0% +which is the tied notation +and it turns out there's five more + + align:start position:0% +and it turns out there's five more + + + align:start position:0% +and it turns out there's five more +things like that which we're going to + + align:start position:0% +things like that which we're going to + + + align:start position:0% +things like that which we're going to +learn what they are and how they + + align:start position:0% + + + + align:start position:0% + +work they all they're used to explain or + + align:start position:0% +work they all they're used to explain or + + + align:start position:0% +work they all they're used to explain or +describe how a function grows in the + + align:start position:0% +describe how a function grows in the + + + align:start position:0% +describe how a function grows in the +limit so for example we had the Tia + + align:start position:0% +limit so for example we had the Tia + + + align:start position:0% +limit so for example we had the Tia +notation and we wrote FX is a g of + + align:start position:0% + + + + align:start position:0% + +x if the + + align:start position:0% +x if the + + + align:start position:0% +x if the +limit as X goes to + + align:start position:0% +limit as X goes to + + + align:start position:0% +limit as X goes to +Infinity of f over + + align:start position:0% +Infinity of f over + + + align:start position:0% +Infinity of f over +G is + + align:start position:0% + + + + align:start position:0% + +one now the next one and most commonly + + align:start position:0% +one now the next one and most commonly + + + align:start position:0% +one now the next one and most commonly +used one in computer science is called + + align:start position:0% +used one in computer science is called + + + align:start position:0% +used one in computer science is called +the O notation or the Big + + align:start position:0% +the O notation or the Big + + + align:start position:0% +the O notation or the Big +O and it's written like this f ofx + + align:start position:0% +O and it's written like this f ofx + + + align:start position:0% +O and it's written like this f ofx +equals o of G + + align:start position:0% +equals o of G + + + align:start position:0% +equals o of G +ofx and it + + align:start position:0% +ofx and it + + + align:start position:0% +ofx and it +means that the + + align:start position:0% +means that the + + + align:start position:0% +means that the +limit as X goes to + + align:start position:0% +limit as X goes to + + + align:start position:0% +limit as X goes to +Infinity of the absolute value of f ofx + + align:start position:0% +Infinity of the absolute value of f ofx + + + align:start position:0% +Infinity of the absolute value of f ofx +over G + + align:start position:0% +over G + + + align:start position:0% +over G +ofx is converges is less than infinity + + align:start position:0% +ofx is converges is less than infinity + + + align:start position:0% +ofx is converges is less than infinity +so it's + + align:start position:0% + + + + align:start position:0% + +finite it can't + + align:start position:0% +finite it can't + + + align:start position:0% +finite it can't +diverge the interpretation is that this + + align:start position:0% +diverge the interpretation is that this + + + align:start position:0% +diverge the interpretation is that this +function is up to constant factors upper + + align:start position:0% +function is up to constant factors upper + + + align:start position:0% +function is up to constant factors upper +bounded by this + + align:start position:0% +bounded by this + + + align:start position:0% +bounded by this +one that this grows the same rate or + + align:start position:0% +one that this grows the same rate or + + + align:start position:0% +one that this grows the same rate or +slower than this one grows as X gets + + align:start position:0% +slower than this one grows as X gets + + + align:start position:0% +slower than this one grows as X gets +large because if if F was growing a lot + + align:start position:0% +large because if if F was growing a lot + + + align:start position:0% +large because if if F was growing a lot +faster than G in the limit then the + + align:start position:0% +faster than G in the limit then the + + + align:start position:0% +faster than G in the limit then the +limit would be the ratio infinity and + + align:start position:0% +limit would be the ratio infinity and + + + align:start position:0% +limit would be the ratio infinity and +we're saying that doesn't happen right + + align:start position:0% +we're saying that doesn't happen right + + + align:start position:0% +we're saying that doesn't happen right +I'm going to do a lot of examples for + + align:start position:0% +I'm going to do a lot of examples for + + + align:start position:0% +I'm going to do a lot of examples for +this + + align:start position:0% + + + + align:start position:0% + +um that's fact let's go over here + + align:start position:0% +um that's fact let's go over here + + + align:start position:0% +um that's fact let's go over here +there's several other ways you'll see it + + align:start position:0% + + + + align:start position:0% + +written for example you'll see people + + align:start position:0% +written for example you'll see people + + + align:start position:0% +written for example you'll see people +write f ofx is less than or equal to o + + align:start position:0% +write f ofx is less than or equal to o + + + align:start position:0% +write f ofx is less than or equal to o +of G of + + align:start position:0% +of G of + + + align:start position:0% +of G of +X because the natural interpretation is + + align:start position:0% +X because the natural interpretation is + + + align:start position:0% +X because the natural interpretation is +f is not growing faster than G sort of + + align:start position:0% +f is not growing faster than G sort of + + + align:start position:0% +f is not growing faster than G sort of +upper bounded by G you'll see people + + align:start position:0% +upper bounded by G you'll see people + + + align:start position:0% +upper bounded by G you'll see people +write f ofx is O of G + + align:start position:0% + + + + align:start position:0% + +ofx and the formal math way that people + + align:start position:0% +ofx and the formal math way that people + + + align:start position:0% +ofx and the formal math way that people +don't use but it's the formally correct + + align:start position:0% +don't use but it's the formally correct + + + align:start position:0% +don't use but it's the formally correct +one is f ofx is an element of O of G + + align:start position:0% +one is f ofx is an element of O of G + + + align:start position:0% +one is f ofx is an element of O of G +ofx and the interpretation there is that + + align:start position:0% +ofx and the interpretation there is that + + + align:start position:0% +ofx and the interpretation there is that +o of G ofx is a set of functions that + + align:start position:0% +o of G ofx is a set of functions that + + + align:start position:0% +o of G ofx is a set of functions that +don't grow any faster than G and F is + + align:start position:0% +don't grow any faster than G and F is + + + align:start position:0% +don't grow any faster than G and F is +one of them you can use any of these and + + align:start position:0% +one of them you can use any of these and + + + align:start position:0% +one of them you can use any of these and +that's fine people will know what you + + align:start position:0% +that's fine people will know what you + + + align:start position:0% +that's fine people will know what you +mean and it'll be fine for the + + align:start position:0% +mean and it'll be fine for the + + + align:start position:0% +mean and it'll be fine for the +class all right let's see some + + align:start position:0% +class all right let's see some + + + align:start position:0% +class all right let's see some +examples and see how to prove a big O + + align:start position:0% + + + + align:start position:0% + +relation let F + + align:start position:0% +relation let F + + + align:start position:0% +relation let F +ofx be the function X and G of X be the + + align:start position:0% +ofx be the function X and G of X be the + + + align:start position:0% +ofx be the function X and G of X be the +function + + align:start position:0% +function + + + align:start position:0% +function +X2 then + + align:start position:0% +X2 then + + + align:start position:0% +X2 then +in this case f ofx is O of G + + align:start position:0% + + + + align:start position:0% + +ofx because X doesn't gr any faster than + + align:start position:0% +ofx because X doesn't gr any faster than + + + align:start position:0% +ofx because X doesn't gr any faster than +x squ as X gets large to prove + + align:start position:0% +x squ as X gets large to prove + + + align:start position:0% +x squ as X gets large to prove +it we take the limit as X goes to + + align:start position:0% +it we take the limit as X goes to + + + align:start position:0% +it we take the limit as X goes to +Infinity of X over + + align:start position:0% +Infinity of X over + + + align:start position:0% +Infinity of X over +X2 that is equal to what what is the + + align:start position:0% +X2 that is equal to what what is the + + + align:start position:0% +X2 that is equal to what what is the +limit of xx2 as X goes to + + align:start position:0% +limit of xx2 as X goes to + + + align:start position:0% +limit of xx2 as X goes to +Infinity zero + + align:start position:0% +Infinity zero + + + align:start position:0% +Infinity zero +and that is less than + + align:start position:0% +and that is less than + + + align:start position:0% +and that is less than +infinity so we proved it so if you get + + align:start position:0% +infinity so we proved it so if you get + + + align:start position:0% +infinity so we proved it so if you get +asked to + + align:start position:0% +asked to + + + align:start position:0% +asked to +prove f is O of G what you do is you + + align:start position:0% +prove f is O of G what you do is you + + + align:start position:0% +prove f is O of G what you do is you +take the limit of f over G as X goes to + + align:start position:0% +take the limit of f over G as X goes to + + + align:start position:0% +take the limit of f over G as X goes to +infinity and show that it doesn't + + align:start position:0% +infinity and show that it doesn't + + + align:start position:0% +infinity and show that it doesn't +diverge all right let's do do another + + align:start position:0% +diverge all right let's do do another + + + align:start position:0% +diverge all right let's do do another +example this case we'll show that f is + + align:start position:0% +example this case we'll show that f is + + + align:start position:0% +example this case we'll show that f is +not o of G + + align:start position:0% + + + + align:start position:0% + +X2 is not o of + + align:start position:0% +X2 is not o of + + + align:start position:0% +X2 is not o of +X of course X squ grows faster than x + + align:start position:0% +X of course X squ grows faster than x + + + align:start position:0% +X of course X squ grows faster than x +but let's see why + + align:start position:0% + + + + align:start position:0% + +not well we take the + + align:start position:0% +not well we take the + + + align:start position:0% +not well we take the +limit as X goes to Infinity of + + align:start position:0% +limit as X goes to Infinity of + + + align:start position:0% +limit as X goes to Infinity of +X2 + + align:start position:0% +X2 + + + align:start position:0% +X2 +overx and what is that + + align:start position:0% +overx and what is that + + + align:start position:0% +overx and what is that +limit + + align:start position:0% +limit + + + align:start position:0% +limit +infinity and so it can't be true that + + align:start position:0% +infinity and so it can't be true that + + + align:start position:0% +infinity and so it can't be true that +it's X2 is O of X because it has to be + + align:start position:0% +it's X2 is O of X because it has to be + + + align:start position:0% +it's X2 is O of X because it has to be +less than + + align:start position:0% +less than + + + align:start position:0% +less than +infinity + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +Infinity sorry Infinity there we go + + align:start position:0% +Infinity sorry Infinity there we go + + + align:start position:0% +Infinity sorry Infinity there we go +that's important in the definition yep + + align:start position:0% + + + + align:start position:0% + +good all right what about + + align:start position:0% +good all right what about + + + align:start position:0% +good all right what about +this is X2 = o of a million times + + align:start position:0% + + + + align:start position:0% + +x yes + + align:start position:0% +x yes + + + align:start position:0% +x yes +no what do you + + align:start position:0% + + + + align:start position:0% + +think this looks pretty darn big that's + + align:start position:0% +think this looks pretty darn big that's + + + align:start position:0% +think this looks pretty darn big that's +a constant that's a + + align:start position:0% +a constant that's a + + + align:start position:0% +a constant that's a +constant so in the limit as X goes to + + align:start position:0% +constant so in the limit as X goes to + + + align:start position:0% +constant so in the limit as X goes to +Infinity this over that is + + align:start position:0% +Infinity this over that is + + + align:start position:0% +Infinity this over that is +infinite all right so + + align:start position:0% +infinite all right so + + + align:start position:0% +infinite all right so +no because the + + align:start position:0% +no because the + + + align:start position:0% +no because the +limit X goes to Infinity of x^2 over 10 + + align:start position:0% +limit X goes to Infinity of x^2 over 10 + + + align:start position:0% +limit X goes to Infinity of x^2 over 10 +6X at equals + + align:start position:0% +6X at equals + + + align:start position:0% +6X at equals +infinity all right so the thing with + + align:start position:0% +infinity all right so the thing with + + + align:start position:0% +infinity all right so the thing with +these Big O notation is you just ignore + + align:start position:0% +these Big O notation is you just ignore + + + align:start position:0% +these Big O notation is you just ignore +constant factors they don't do anything + + align:start position:0% +constant factors they don't do anything + + + align:start position:0% +constant factors they don't do anything +just forget about + + align:start position:0% +just forget about + + + align:start position:0% +just forget about +them all + + align:start position:0% +them all + + + align:start position:0% +them all +right what about this + + align:start position:0% +right what about this + + + align:start position:0% +right what about this +is 10 6 x equal o of + + align:start position:0% + + + + align:start position:0% + +x^2 + + align:start position:0% +x^2 + + + align:start position:0% +x^2 +yes because you just ignore the constant + + align:start position:0% +yes because you just ignore the constant + + + align:start position:0% +yes because you just ignore the constant +that's what the Big O is for and why + + align:start position:0% +that's what the Big O is for and why + + + align:start position:0% +that's what the Big O is for and why +it's used all the time in computer + + align:start position:0% +it's used all the time in computer + + + align:start position:0% +it's used all the time in computer +science so yes that's true proof is very + + align:start position:0% +science so yes that's true proof is very + + + align:start position:0% +science so yes that's true proof is very +simple the limit as X goes to Infinity + + align:start position:0% +simple the limit as X goes to Infinity + + + align:start position:0% +simple the limit as X goes to Infinity +of 100 X2 whoops I you can even put a + + align:start position:0% +of 100 X2 whoops I you can even put a + + + align:start position:0% +of 100 X2 whoops I you can even put a +square there 10 6 X2 + + align:start position:0% +square there 10 6 X2 + + + align:start position:0% +square there 10 6 X2 +over + + align:start position:0% +over + + + align:start position:0% +over +x^2 is 10 + + align:start position:0% +x^2 is 10 + + + align:start position:0% +x^2 is 10 +6 that's less than + + align:start position:0% + + + + align:start position:0% + +infinity in fact I could take any + + align:start position:0% +infinity in fact I could take any + + + align:start position:0% +infinity in fact I could take any +quadratic + + align:start position:0% +quadratic + + + align:start position:0% +quadratic +polinomial x^2 + 100x + 10 7th is O of + + align:start position:0% + + + + align:start position:0% + +x^2 right because smaller order terms + + align:start position:0% +x^2 right because smaller order terms + + + align:start position:0% +x^2 right because smaller order terms +don't matter the limit of this here over + + align:start position:0% +don't matter the limit of this here over + + + align:start position:0% +don't matter the limit of this here over +that in that case is one so it's less + + align:start position:0% +that in that case is one so it's less + + + align:start position:0% +that in that case is one so it's less +than infinity as X gets + + align:start position:0% + + + + align:start position:0% + +big all right let's do a few + + align:start position:0% + + + + align:start position:0% + +more this really is not so hard it's a + + align:start position:0% +more this really is not so hard it's a + + + align:start position:0% +more this really is not so hard it's a +little dull uh but it's you got to you + + align:start position:0% +little dull uh but it's you got to you + + + align:start position:0% +little dull uh but it's you got to you +got to know it for + + align:start position:0% + + + + align:start position:0% + +later in fact you take classes like 6046 + + align:start position:0% +later in fact you take classes like 6046 + + + align:start position:0% +later in fact you take classes like 6046 +and you'll you'll never see any + + align:start position:0% +and you'll you'll never see any + + + align:start position:0% +and you'll you'll never see any +constants because everything is + + align:start position:0% +constants because everything is + + + align:start position:0% +constants because everything is +things like Big O and in the other + + align:start position:0% +things like Big O and in the other + + + align:start position:0% +things like Big O and in the other +notation we'll talk + + align:start position:0% +notation we'll talk + + + align:start position:0% +notation we'll talk +about what about this x to the + + align:start position:0% +about what about this x to the + + + align:start position:0% +about what about this x to the +10th equal o of e to the + + align:start position:0% + + + + align:start position:0% + +x is x 10 o of e to the + + align:start position:0% + + + + align:start position:0% + +X yeah it is because so this is a + + align:start position:0% + + + + align:start position:0% + +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +proof limit as X goes to INF infinity x + + align:start position:0% +proof limit as X goes to INF infinity x + + + align:start position:0% +proof limit as X goes to INF infinity x +10 e x that equals z which is certainly + + align:start position:0% +10 e x that equals z which is certainly + + + align:start position:0% +10 e x that equals z which is certainly +less than + + align:start position:0% +less than + + + align:start position:0% +less than +infinity all right now the reason this + + align:start position:0% +infinity all right now the reason this + + + align:start position:0% +infinity all right now the reason this +stuff is useful when you're doing the + + align:start position:0% +stuff is useful when you're doing the + + + align:start position:0% +stuff is useful when you're doing the +analysis of algorithms is because when + + align:start position:0% +analysis of algorithms is because when + + + align:start position:0% +analysis of algorithms is because when +you're talking about things like matrix + + align:start position:0% +you're talking about things like matrix + + + align:start position:0% +you're talking about things like matrix +multiplication algorithms or things like + + align:start position:0% +multiplication algorithms or things like + + + align:start position:0% +multiplication algorithms or things like +that the actual running time depends on + + align:start position:0% +that the actual running time depends on + + + align:start position:0% +that the actual running time depends on +the machine you're dealing with the + + align:start position:0% +the machine you're dealing with the + + + align:start position:0% +the machine you're dealing with the +machine characteristics you know details + + align:start position:0% +machine characteristics you know details + + + align:start position:0% +machine characteristics you know details +in how you count steps of the algorithm + + align:start position:0% +in how you count steps of the algorithm + + + align:start position:0% +in how you count steps of the algorithm +for example in doing matrix + + align:start position:0% +for example in doing matrix + + + align:start position:0% +for example in doing matrix +multiplication do you count multiply + + align:start position:0% +multiplication do you count multiply + + + align:start position:0% +multiplication do you count multiply +different than you count plus addition + + align:start position:0% +different than you count plus addition + + + align:start position:0% +different than you count plus addition +and it just if you start getting caught + + align:start position:0% +and it just if you start getting caught + + + align:start position:0% +and it just if you start getting caught +up in all those details you lose the + + align:start position:0% +up in all those details you lose the + + + align:start position:0% +up in all those details you lose the +important fact of the algorithm for + + align:start position:0% +important fact of the algorithm for + + + align:start position:0% +important fact of the algorithm for +example matrix multiplication the + + align:start position:0% +example matrix multiplication the + + + align:start position:0% +example matrix multiplication the +elementary algorithm takes order o of n + + align:start position:0% +elementary algorithm takes order o of n + + + align:start position:0% +elementary algorithm takes order o of n +Cub + + align:start position:0% +Cub + + + align:start position:0% +Cub +steps and and that's the important fact + + align:start position:0% +steps and and that's the important fact + + + align:start position:0% +steps and and that's the important fact +and it tells you that if you double the + + align:start position:0% +and it tells you that if you double the + + + align:start position:0% +and it tells you that if you double the +size of the Matrix the running time will + + align:start position:0% +size of the Matrix the running time will + + + align:start position:0% +size of the Matrix the running time will +increase by at most a factor of eight in + + align:start position:0% +increase by at most a factor of eight in + + + align:start position:0% +increase by at most a factor of eight in +the limit + + align:start position:0% +the limit + + + align:start position:0% +the limit +as n gets large and so you might write + + align:start position:0% +as n gets large and so you might write + + + align:start position:0% +as n gets large and so you might write +things like the time to + + align:start position:0% + + + + align:start position:0% + +multiply n byn + + align:start position:0% + + + + align:start position:0% + +matrices you might call that t of N and + + align:start position:0% +matrices you might call that t of N and + + + align:start position:0% +matrices you might call that t of N and +then state that is O of n + + align:start position:0% +then state that is O of n + + + align:start position:0% +then state that is O of n +cubed all right and you don't have to + + align:start position:0% +cubed all right and you don't have to + + + align:start position:0% +cubed all right and you don't have to +worry about what computer it's running + + align:start position:0% +worry about what computer it's running + + + align:start position:0% +worry about what computer it's running +on you know exactly how you're counting + + align:start position:0% +on you know exactly how you're counting + + + align:start position:0% +on you know exactly how you're counting +the details of what a step is or what + + align:start position:0% +the details of what a step is or what + + + align:start position:0% +the details of what a step is or what +time is the important thing is that it's + + align:start position:0% +time is the important thing is that it's + + + align:start position:0% +time is the important thing is that it's +growing at most as a cubic of the size + + align:start position:0% +growing at most as a cubic of the size + + + align:start position:0% +growing at most as a cubic of the size +of the + + align:start position:0% +of the + + + align:start position:0% +of the +matrices and so in 6046 and in + + align:start position:0% +matrices and so in 6046 and in + + + align:start position:0% +matrices and so in 6046 and in +66 you will spend lots of time proving + + align:start position:0% +66 you will spend lots of time proving + + + align:start position:0% +66 you will spend lots of time proving +that things are running time or the size + + align:start position:0% +that things are running time or the size + + + align:start position:0% +that things are running time or the size +is O of some function of the input + + align:start position:0% +is O of some function of the input + + + align:start position:0% +is O of some function of the input +size all + + align:start position:0% +size all + + + align:start position:0% +size all +right any + + align:start position:0% +right any + + + align:start position:0% +right any +questions yeah + + align:start position:0% + + + + align:start position:0% + +yeah you know gets all dicey if you do + + align:start position:0% +yeah you know gets all dicey if you do + + + align:start position:0% +yeah you know gets all dicey if you do +oscillatory things and depends how you + + align:start position:0% +oscillatory things and depends how you + + + align:start position:0% +oscillatory things and depends how you +define it so we're going to stay away + + align:start position:0% +define it so we're going to stay away + + + align:start position:0% +define it so we're going to stay away +from that um and just stick with this + + align:start position:0% +from that um and just stick with this + + + align:start position:0% +from that um and just stick with this +definition so if this guy oscillates + + align:start position:0% +definition so if this guy oscillates + + + align:start position:0% +definition so if this guy oscillates +like f is a sign s of x s of X is O of X + + align:start position:0% +like f is a sign s of x s of X is O of X + + + align:start position:0% +like f is a sign s of x s of X is O of X +all right doesn't have to converge but + + align:start position:0% +all right doesn't have to converge but + + + align:start position:0% +all right doesn't have to converge but +as long as the ratio is less than + + align:start position:0% + + + + align:start position:0% + +Infinity yeah everything you do maybe + + align:start position:0% +Infinity yeah everything you do maybe + + + align:start position:0% +Infinity yeah everything you do maybe +you'll see sign functions sometimes but + + align:start position:0% +you'll see sign functions sometimes but + + + align:start position:0% +you'll see sign functions sometimes but +everything you do in algorithms is going + + align:start position:0% +everything you do in algorithms is going + + + align:start position:0% +everything you do in algorithms is going +to be growing monotonically yeah nothing + + align:start position:0% +to be growing monotonically yeah nothing + + + align:start position:0% +to be growing monotonically yeah nothing +no wacky stuff in math usually any other + + align:start position:0% +no wacky stuff in math usually any other + + + align:start position:0% +no wacky stuff in math usually any other +questions + + align:start position:0% + + + + align:start position:0% + +yeah yeah it's upper bounded so it's not + + align:start position:0% +yeah yeah it's upper bounded so it's not + + + align:start position:0% +yeah yeah it's upper bounded so it's not +the same we'll get to the same in a + + align:start position:0% +the same we'll get to the same in a + + + align:start position:0% +the same we'll get to the same in a +minute but it's upper bounded f is upper + + align:start position:0% +minute but it's upper bounded f is upper + + + align:start position:0% +minute but it's upper bounded f is upper +bounded by G up to a fixed constant as + + align:start position:0% +bounded by G up to a fixed constant as + + + align:start position:0% +bounded by G up to a fixed constant as +you go to infinity and all constants get + + align:start position:0% +you go to infinity and all constants get + + + align:start position:0% +you go to infinity and all constants get +washed away by + + align:start position:0% +washed away by + + + align:start position:0% +washed away by +o + + align:start position:0% + + + + align:start position:0% + +yeah uh ah why is this true well uh + + align:start position:0% +yeah uh ah why is this true well uh + + + align:start position:0% +yeah uh ah why is this true well uh +technically we'd have to go back to + + align:start position:0% +technically we'd have to go back to + + + align:start position:0% +technically we'd have to go back to +calculus and use lal's rule or something + + align:start position:0% +calculus and use lal's rule or something + + + align:start position:0% +calculus and use lal's rule or something +like that because this function + + align:start position:0% +like that because this function + + + align:start position:0% +like that because this function +exponential grows a lot faster than x to + + align:start position:0% +exponential grows a lot faster than x to + + + align:start position:0% +exponential grows a lot faster than x to +the 10th so lal's rule is you take the + + align:start position:0% +the 10th so lal's rule is you take the + + + align:start position:0% +the 10th so lal's rule is you take the +derivative of this over the derivative + + align:start position:0% +derivative of this over the derivative + + + align:start position:0% +derivative of this over the derivative +of that then you'd have x to the 9th + + align:start position:0% +of that then you'd have x to the 9th + + + align:start position:0% +of that then you'd have x to the 9th +over e to X You' do it n more times and + + align:start position:0% +over e to X You' do it n more times and + + + align:start position:0% +over e to X You' do it n more times and +you'd get 10 factorial over e to X and + + align:start position:0% +you'd get 10 factorial over e to X and + + + align:start position:0% +you'd get 10 factorial over e to X and +that limit is zero so that's how you'd + + align:start position:0% +that limit is zero so that's how you'd + + + align:start position:0% +that limit is zero so that's how you'd +actually do it using lal's + + align:start position:0% +actually do it using lal's + + + align:start position:0% +actually do it using lal's +rule yeah any polinomial grows slower + + align:start position:0% +rule yeah any polinomial grows slower + + + align:start position:0% +rule yeah any polinomial grows slower +than any + + align:start position:0% + + + + align:start position:0% + +exponential all right let's uh let's now + + align:start position:0% +exponential all right let's uh let's now + + + align:start position:0% +exponential all right let's uh let's now +do some examples that can get you + + align:start position:0% +do some examples that can get you + + + align:start position:0% +do some examples that can get you +screwed + + align:start position:0% + + + + align:start position:0% + +up what about this one + + align:start position:0% +up what about this one + + + align:start position:0% +up what about this one +is 4 the x o of 2 to the + + align:start position:0% + + + + align:start position:0% + +x is that + + align:start position:0% +x is that + + + align:start position:0% +x is that +true no it's not true I mean the mistake + + align:start position:0% +true no it's not true I mean the mistake + + + align:start position:0% +true no it's not true I mean the mistake +you might make is say oh four and two + + align:start position:0% +you might make is say oh four and two + + + align:start position:0% +you might make is say oh four and two +four is only double two Big O wipes out + + align:start position:0% +four is only double two Big O wipes out + + + align:start position:0% +four is only double two Big O wipes out +constant factors so the answer is yes + + align:start position:0% +constant factors so the answer is yes + + + align:start position:0% +constant factors so the answer is yes +that would be bad better to look at the + + align:start position:0% +that would be bad better to look at the + + + align:start position:0% +that would be bad better to look at the +limit so we'll State the correct theorem + + align:start position:0% +limit so we'll State the correct theorem + + + align:start position:0% +limit so we'll State the correct theorem +4 X is not o of 2 x and the proof is + + align:start position:0% +4 X is not o of 2 x and the proof is + + + align:start position:0% +4 X is not o of 2 x and the proof is +obtained by looking at the + + align:start position:0% +obtained by looking at the + + + align:start position:0% +obtained by looking at the +limit as X goes to Infinity of 4 x over + + align:start position:0% +limit as X goes to Infinity of 4 x over + + + align:start position:0% +limit as X goes to Infinity of 4 x over +2 x that is just the limit 4 x over 2 x + + align:start position:0% +2 x that is just the limit 4 x over 2 x + + + align:start position:0% +2 x that is just the limit 4 x over 2 x +is 2 X that's + + align:start position:0% +is 2 X that's + + + align:start position:0% +is 2 X that's +Infinity so the limit is not + + align:start position:0% +Infinity so the limit is not + + + align:start position:0% +Infinity so the limit is not +bounded right so it is not Big O + + align:start position:0% +bounded right so it is not Big O + + + align:start position:0% +bounded right so it is not Big O +there right here's one + + align:start position:0% + + + + align:start position:0% + +is 10 o of + + align:start position:0% + + + + align:start position:0% + +one I've purposely written it this + + align:start position:0% +one I've purposely written it this + + + align:start position:0% +one I've purposely written it this +way yes it is and in fact the + + align:start position:0% +way yes it is and in fact the + + + align:start position:0% +way yes it is and in fact the +interpretation here is that you've got + + align:start position:0% +interpretation here is that you've got + + + align:start position:0% +interpretation here is that you've got +some function f ofx that's just always + + align:start position:0% +some function f ofx that's just always + + + align:start position:0% +some function f ofx that's just always +equal to 10 and some function G ofx + + align:start position:0% +equal to 10 and some function G ofx + + + align:start position:0% +equal to 10 and some function G ofx +that's always equal to one and then it + + align:start position:0% +that's always equal to one and then it + + + align:start position:0% +that's always equal to one and then it +is true in this case that f ofx is O of + + align:start position:0% +is true in this case that f ofx is O of + + + align:start position:0% +is true in this case that f ofx is O of +G of x + + align:start position:0% +G of x + + + align:start position:0% +G of x +X all right but any constant function is + + align:start position:0% +X all right but any constant function is + + + align:start position:0% +X all right but any constant function is +O of any other constant + + align:start position:0% +O of any other constant + + + align:start position:0% +O of any other constant +function we're going to revisit this in + + align:start position:0% +function we're going to revisit this in + + + align:start position:0% +function we're going to revisit this in +a nastier scenario in a little + + align:start position:0% +a nastier scenario in a little + + + align:start position:0% +a nastier scenario in a little +bit okay + + align:start position:0% + + + + align:start position:0% + +um sometimes you'll see notation like + + align:start position:0% +um sometimes you'll see notation like + + + align:start position:0% +um sometimes you'll see notation like +this h of n in fact we saw this earlier + + align:start position:0% +this h of n in fact we saw this earlier + + + align:start position:0% +this h of n in fact we saw this earlier +is the log of n Plus + + align:start position:0% +is the log of n Plus + + + align:start position:0% +is the log of n Plus +Delta plus o of 1/ n when we wrote out + + align:start position:0% +Delta plus o of 1/ n when we wrote out + + + align:start position:0% +Delta plus o of 1/ n when we wrote out +the formula for the nth harmonic number + + align:start position:0% +the formula for the nth harmonic number + + + align:start position:0% +the formula for the nth harmonic number +it was log of n plus Oiler constant plus + + align:start position:0% +it was log of n plus Oiler constant plus + + + align:start position:0% +it was log of n plus Oiler constant plus +something like 1/ n constant time 1/ n + + align:start position:0% +something like 1/ n constant time 1/ n + + + align:start position:0% +something like 1/ n constant time 1/ n +and then some even smaller terms and so + + align:start position:0% +and then some even smaller terms and so + + + align:start position:0% +and then some even smaller terms and so +people will write it like this and it + + align:start position:0% +people will write it like this and it + + + align:start position:0% +people will write it like this and it +tells you that the error terms grow no + + align:start position:0% +tells you that the error terms grow no + + + align:start position:0% +tells you that the error terms grow no +faster than a constant * 1 n technically + + align:start position:0% +faster than a constant * 1 n technically + + + align:start position:0% +faster than a constant * 1 n technically +this is the wrong way to write it but + + align:start position:0% +this is the wrong way to write it but + + + align:start position:0% +this is the wrong way to write it but +everybody does it so you can + + align:start position:0% +everybody does it so you can + + + align:start position:0% +everybody does it so you can +too what it means is this h of n minus + + align:start position:0% +too what it means is this h of n minus + + + align:start position:0% +too what it means is this h of n minus +Ln of n minus Delta is O of + + align:start position:0% +Ln of n minus Delta is O of + + + align:start position:0% +Ln of n minus Delta is O of +1/n all right that's the correct way to + + align:start position:0% +1/n all right that's the correct way to + + + align:start position:0% +1/n all right that's the correct way to +write it because you're taking the ratio + + align:start position:0% +write it because you're taking the ratio + + + align:start position:0% +write it because you're taking the ratio +of this over that uh this is how people + + align:start position:0% +of this over that uh this is how people + + + align:start position:0% +of this over that uh this is how people +will do it all right so just know make + + align:start position:0% +will do it all right so just know make + + + align:start position:0% +will do it all right so just know make +sure you understand that um what it + + align:start position:0% +sure you understand that um what it + + + align:start position:0% +sure you understand that um what it +means when we put it over there same + + align:start position:0% +means when we put it over there same + + + align:start position:0% +means when we put it over there same +thing with tiled notation people will + + align:start position:0% +thing with tiled notation people will + + + align:start position:0% +thing with tiled notation people will +write this a h of n is Tilda Ln of n + + align:start position:0% +write this a h of n is Tilda Ln of n + + + align:start position:0% +write this a h of n is Tilda Ln of n +plus Oiler constant the right way to + + align:start position:0% +plus Oiler constant the right way to + + + align:start position:0% +plus Oiler constant the right way to +write it is hn minus Oilers constant is + + align:start position:0% +write it is hn minus Oilers constant is + + + align:start position:0% +write it is hn minus Oilers constant is +TAA L of + + align:start position:0% +TAA L of + + + align:start position:0% +TAA L of +n now can anybody tell me + + align:start position:0% +n now can anybody tell me + + + align:start position:0% +n now can anybody tell me +why this is really not a good thing to + + align:start position:0% +why this is really not a good thing to + + + align:start position:0% +why this is really not a good thing to +do you think of how things get really + + align:start position:0% +do you think of how things get really + + + align:start position:0% +do you think of how things get really +screwed up if you allow to start doing + + align:start position:0% +screwed up if you allow to start doing + + + align:start position:0% +screwed up if you allow to start doing +this can you think of anything + + align:start position:0% +this can you think of anything + + + align:start position:0% +this can you think of anything +that what if what if I did this is this + + align:start position:0% + + + + align:start position:0% + +true + + align:start position:0% + + + + align:start position:0% + +10 the nth harmonic is harmonic number + + align:start position:0% +10 the nth harmonic is harmonic number + + + align:start position:0% +10 the nth harmonic is harmonic number +is tilled of log of n+ + + align:start position:0% +is tilled of log of n+ + + + align:start position:0% +is tilled of log of n+ +10 is that + + align:start position:0% +10 is that + + + align:start position:0% +10 is that +true think about that people are shaking + + align:start position:0% +true think about that people are shaking + + + align:start position:0% +true think about that people are shaking +their heads I mean how can it be true + + align:start position:0% +their heads I mean how can it be true + + + align:start position:0% +their heads I mean how can it be true +because that we know this is we know + + align:start position:0% +because that we know this is we know + + + align:start position:0% +because that we know this is we know +that's what it + + align:start position:0% +that's what it + + + align:start position:0% +that's what it +is in fact this is true I could even + + align:start position:0% +is in fact this is true I could even + + + align:start position:0% +is in fact this is true I could even +make it you know a million 10 the six + + align:start position:0% +make it you know a million 10 the six + + + align:start position:0% +make it you know a million 10 the six +here it's + + align:start position:0% +here it's + + + align:start position:0% +here it's +true because the ratio of this over that + + align:start position:0% +true because the ratio of this over that + + + align:start position:0% +true because the ratio of this over that +and the limit is + + align:start position:0% +and the limit is + + + align:start position:0% +and the limit is +what one and that's all I need for + + align:start position:0% +what one and that's all I need for + + + align:start position:0% +what one and that's all I need for +Tilda all right so when I wrote this + + align:start position:0% +Tilda all right so when I wrote this + + + align:start position:0% +Tilda all right so when I wrote this +everybody knew what I + + align:start position:0% +everybody knew what I + + + align:start position:0% +everybody knew what I +meant but I could write this and be just + + align:start position:0% +meant but I could write this and be just + + + align:start position:0% +meant but I could write this and be just +as true + + align:start position:0% +as true + + + align:start position:0% +as true +mathematically and so you got to be sort + + align:start position:0% +mathematically and so you got to be sort + + + align:start position:0% +mathematically and so you got to be sort +of careful you know about this really + + align:start position:0% +of careful you know about this really + + + align:start position:0% +of careful you know about this really +the right way to do it is this because + + align:start position:0% +the right way to do it is this because + + + align:start position:0% +the right way to do it is this because +now we're taking off that term and it's + + align:start position:0% +now we're taking off that term and it's + + + align:start position:0% +now we're taking off that term and it's +then it's actually I did this wrong I + + align:start position:0% +then it's actually I did this wrong I + + + align:start position:0% +then it's actually I did this wrong I +should have put the L in oops I should + + align:start position:0% +should have put the L in oops I should + + + align:start position:0% +should have put the L in oops I should +have done this way let me rewrite that + + align:start position:0% +have done this way let me rewrite that + + + align:start position:0% +have done this way let me rewrite that +the right way to do it is H of n yeah is + + align:start position:0% +the right way to do it is H of n yeah is + + + align:start position:0% +the right way to do it is H of n yeah is +this you put the small term out over + + align:start position:0% +this you put the small term out over + + + align:start position:0% +this you put the small term out over +here that's the right way because now + + align:start position:0% +here that's the right way because now + + + align:start position:0% +here that's the right way because now +it's not true that it's 10 the 6 out + + align:start position:0% +it's not true that it's 10 the 6 out + + + align:start position:0% +it's not true that it's 10 the 6 out +here all right for the ratio of that + + align:start position:0% +here all right for the ratio of that + + + align:start position:0% +here all right for the ratio of that +over this + + align:start position:0% +over this + + + align:start position:0% +over this +guy all right so you can do it but be + + align:start position:0% +guy all right so you can do it but be + + + align:start position:0% +guy all right so you can do it but be +careful because you might write WR wrong + + align:start position:0% +careful because you might write WR wrong + + + align:start position:0% +careful because you might write WR wrong +things that technically would fit the + + align:start position:0% +things that technically would fit the + + + align:start position:0% +things that technically would fit the +definition same thing with Big O same + + align:start position:0% +definition same thing with Big O same + + + align:start position:0% +definition same thing with Big O same +same problem there any + + align:start position:0% +same problem there any + + + align:start position:0% +same problem there any +questions about + + align:start position:0% + + + + align:start position:0% + +that all + + align:start position:0% +that all + + + align:start position:0% +that all +right all right now one thing that + + align:start position:0% +right all right now one thing that + + + align:start position:0% +right all right now one thing that +people do all the time that you cannot + + align:start position:0% +people do all the time that you cannot + + + align:start position:0% +people do all the time that you cannot +do is to use Big O as a lower + + align:start position:0% + + + + align:start position:0% + +bound all right so that's one abuse that + + align:start position:0% +bound all right so that's one abuse that + + + align:start position:0% +bound all right so that's one abuse that +we won't you'll get marked wrong for + + align:start position:0% +we won't you'll get marked wrong for + + + align:start position:0% +we won't you'll get marked wrong for +doing + + align:start position:0% +doing + + + align:start position:0% +doing +that even though famous researchers will + + align:start position:0% +that even though famous researchers will + + + align:start position:0% +that even though famous researchers will +do it you'll probably even have a + + align:start position:0% +do it you'll probably even have a + + + align:start position:0% +do it you'll probably even have a +professor do it + + align:start position:0% +professor do it + + + align:start position:0% +professor do it +sometime + + align:start position:0% +sometime + + + align:start position:0% +sometime +uh so you may not do this F ofx is + + align:start position:0% +uh so you may not do this F ofx is + + + align:start position:0% +uh so you may not do this F ofx is +bigger than or equal to O of G of X that + + align:start position:0% +bigger than or equal to O of G of X that + + + align:start position:0% +bigger than or equal to O of G of X that +is + + align:start position:0% + + + + align:start position:0% + +meaningless because the whole point of + + align:start position:0% +meaningless because the whole point of + + + align:start position:0% +meaningless because the whole point of +Big O is that it's an upper bound so you + + align:start position:0% +Big O is that it's an upper bound so you + + + align:start position:0% +Big O is that it's an upper bound so you +can't use it as a lower bound and the + + align:start position:0% +can't use it as a lower bound and the + + + align:start position:0% +can't use it as a lower bound and the +reason you can't do it is because there + + align:start position:0% +reason you can't do it is because there + + + align:start position:0% +reason you can't do it is because there +is another symbol to do what you want to + + align:start position:0% +is another symbol to do what you want to + + + align:start position:0% +is another symbol to do what you want to +do and that's called the Omega + + align:start position:0% + + + + align:start position:0% + +symbol and it's written like + + align:start position:0% +symbol and it's written like + + + align:start position:0% +symbol and it's written like +this it's a capital + + align:start position:0% +this it's a capital + + + align:start position:0% +this it's a capital +Omega and it's if the limit as X goes to + + align:start position:0% +Omega and it's if the limit as X goes to + + + align:start position:0% +Omega and it's if the limit as X goes to +Infinity of f ofx + + align:start position:0% +Infinity of f ofx + + + align:start position:0% +Infinity of f ofx +over G ofx is greater than + + align:start position:0% +over G ofx is greater than + + + align:start position:0% +over G ofx is greater than +zero okay so now we're getting the lower + + align:start position:0% +zero okay so now we're getting the lower + + + align:start position:0% +zero okay so now we're getting the lower +bound version in fact it's just the + + align:start position:0% +bound version in fact it's just the + + + align:start position:0% +bound version in fact it's just the +opposite of Big + + align:start position:0% +opposite of Big + + + align:start position:0% +opposite of Big +O fact state of theorem not hard to + + align:start position:0% +O fact state of theorem not hard to + + + align:start position:0% +O fact state of theorem not hard to +prove we won't do it f ofx equals o of G + + align:start position:0% +prove we won't do it f ofx equals o of G + + + align:start position:0% +prove we won't do it f ofx equals o of G +ofx if and only if G of x equals big + + align:start position:0% +ofx if and only if G of x equals big + + + align:start position:0% +ofx if and only if G of x equals big +Omega of f ofx + + align:start position:0% + + + + align:start position:0% + +in other words F grows no faster than + + align:start position:0% +in other words F grows no faster than + + + align:start position:0% +in other words F grows no faster than +G if and only if G grows at least as + + align:start position:0% +G if and only if G grows at least as + + + align:start position:0% +G if and only if G grows at least as +fast as + + align:start position:0% +fast as + + + align:start position:0% +fast as +F one's an upper bound one's a lower + + align:start position:0% +F one's an upper bound one's a lower + + + align:start position:0% +F one's an upper bound one's a lower +bound and you just got to use the symbol + + align:start position:0% +bound and you just got to use the symbol + + + align:start position:0% +bound and you just got to use the symbol +the right way now you can do this you + + align:start position:0% +the right way now you can do this you + + + align:start position:0% +the right way now you can do this you +can write F ofx bigger than or equal to + + align:start position:0% +can write F ofx bigger than or equal to + + + align:start position:0% +can write F ofx bigger than or equal to +G of Omega G ofx that's + + align:start position:0% +G of Omega G ofx that's + + + align:start position:0% +G of Omega G ofx that's +okay all right that's all right to do + + align:start position:0% +okay all right that's all right to do + + + align:start position:0% +okay all right that's all right to do +all right let's do some examples + + align:start position:0% + + + + align:start position:0% + +so X2 is Omega of X because it grows + + align:start position:0% +so X2 is Omega of X because it grows + + + align:start position:0% +so X2 is Omega of X because it grows +faster than + + align:start position:0% +faster than + + + align:start position:0% +faster than +x 2 to the + + align:start position:0% +x 2 to the + + + align:start position:0% +x 2 to the +x is Omega of + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +x^2 all right + + align:start position:0% +x^2 all right + + + align:start position:0% +x^2 all right +X over + + align:start position:0% +X over + + + align:start position:0% +X over +100 is Omega of 100 x + + + align:start position:0% + + + + align:start position:0% + +25 because constants don't matter X over + + align:start position:0% +25 because constants don't matter X over + + + align:start position:0% +25 because constants don't matter X over +100 grows at least as fast as 100x does + + align:start position:0% +100 grows at least as fast as 100x does + + + align:start position:0% +100 grows at least as fast as 100x does +in terms because we're measuring the + + align:start position:0% +in terms because we're measuring the + + + align:start position:0% +in terms because we're measuring the +growth so constants go + + align:start position:0% +growth so constants go + + + align:start position:0% +growth so constants go +away if you want to say the running time + + align:start position:0% +away if you want to say the running time + + + align:start position:0% +away if you want to say the running time +of that algorithm is at least + + align:start position:0% +of that algorithm is at least + + + align:start position:0% +of that algorithm is at least +quadratic you would write T of n is + + align:start position:0% +quadratic you would write T of n is + + + align:start position:0% +quadratic you would write T of n is +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +n^2 all right and that says that the + + align:start position:0% +n^2 all right and that says that the + + + align:start position:0% +n^2 all right and that says that the +running time is at least + + align:start position:0% +running time is at least + + + align:start position:0% +running time is at least +n^2 any questions on big + + align:start position:0% +n^2 any questions on big + + + align:start position:0% +n^2 any questions on big +Omega not too hard once you have big O + + align:start position:0% +Omega not too hard once you have big O + + + align:start position:0% +Omega not too hard once you have big O +it's just the + + align:start position:0% +it's just the + + + align:start position:0% +it's just the +opposite all right the next symbol is + + align:start position:0% +opposite all right the next symbol is + + + align:start position:0% +opposite all right the next symbol is +the version of equality where you're + + align:start position:0% +the version of equality where you're + + + align:start position:0% +the version of equality where you're +bigger at least as big as and at most as + + align:start position:0% +bigger at least as big as and at most as + + + align:start position:0% +bigger at least as big as and at most as +big as there's a special symbol for + + align:start position:0% +big as there's a special symbol for + + + align:start position:0% +big as there's a special symbol for +that so in that case we use + + align:start position:0% + + + + align:start position:0% + +Theta and we say that f ofx equals Theta + + align:start position:0% +Theta and we say that f ofx equals Theta + + + align:start position:0% +Theta and we say that f ofx equals Theta +of G + + align:start position:0% +of G + + + align:start position:0% +of G +ofx if the + + align:start position:0% +ofx if the + + + align:start position:0% +ofx if the +limit is both bigger than + + align:start position:0% +limit is both bigger than + + + align:start position:0% +limit is both bigger than +zero and less than + + align:start position:0% +zero and less than + + + align:start position:0% +zero and less than +infinity all right so it's just a + + align:start position:0% +infinity all right so it's just a + + + align:start position:0% +infinity all right so it's just a +shorthand way of saying Big O and big + + align:start position:0% +shorthand way of saying Big O and big + + + align:start position:0% +shorthand way of saying Big O and big +Omega that's what Theta means it just + + align:start position:0% +Omega that's what Theta means it just + + + align:start position:0% +Omega that's what Theta means it just +both hold + + align:start position:0% +both hold + + + align:start position:0% +both hold +true all right that's a theorem which is + + align:start position:0% +true all right that's a theorem which is + + + align:start position:0% +true all right that's a theorem which is +not hard to prove but we won't do it f + + align:start position:0% +not hard to prove but we won't do it f + + + align:start position:0% +not hard to prove but we won't do it f +ofx equals Theta of G + + align:start position:0% +ofx equals Theta of G + + + align:start position:0% +ofx equals Theta of G +ofx if and only + + align:start position:0% +ofx if and only + + + align:start position:0% +ofx if and only +if F ofx equal o of G + + align:start position:0% +if F ofx equal o of G + + + align:start position:0% +if F ofx equal o of G +ofx + + align:start position:0% +ofx + + + align:start position:0% +ofx +and F + + align:start position:0% +and F + + + align:start position:0% +and F +ofx equal Omega G + + align:start position:0% + + + + align:start position:0% + +ofx all right so let's do some examples + + align:start position:0% +ofx all right so let's do some examples + + + align:start position:0% +ofx all right so let's do some examples +of + + align:start position:0% + + + + align:start position:0% + +Thea so for example 10 x Cub - 20x + 1 + + align:start position:0% +Thea so for example 10 x Cub - 20x + 1 + + + align:start position:0% +Thea so for example 10 x Cub - 20x + 1 +is more easily written as Theta of X + + align:start position:0% +is more easily written as Theta of X + + + align:start position:0% +is more easily written as Theta of X +Cub because the constants don't matter + + align:start position:0% +Cub because the constants don't matter + + + align:start position:0% +Cub because the constants don't matter +the low or term terms don't matter what + + align:start position:0% +the low or term terms don't matter what + + + align:start position:0% +the low or term terms don't matter what +about this is X over log of + + align:start position:0% +about this is X over log of + + + align:start position:0% +about this is X over log of +x is that Theta of + + align:start position:0% + + + + align:start position:0% + +x x over log of x is that Theta of + + align:start position:0% +x x over log of x is that Theta of + + + align:start position:0% +x x over log of x is that Theta of +X people are nodding their + + align:start position:0% + + + + align:start position:0% + +heads let's see let's + + align:start position:0% +heads let's see let's + + + align:start position:0% +heads let's see let's +check um the limit as X goes to Infinity + + align:start position:0% +check um the limit as X goes to Infinity + + + align:start position:0% +check um the limit as X goes to Infinity +of X over log of x / + + align:start position:0% +of X over log of x / + + + align:start position:0% +of X over log of x / +X well the x is cancel that's the limit + + align:start position:0% +X well the x is cancel that's the limit + + + align:start position:0% +X well the x is cancel that's the limit +as X goes to Infinity of 1 over log of + + align:start position:0% +as X goes to Infinity of 1 over log of + + + align:start position:0% +as X goes to Infinity of 1 over log of +x what's + + align:start position:0% +x what's + + + align:start position:0% +x what's +that + + align:start position:0% +that + + + align:start position:0% +that +zero uh oh it is not Theta I got to be + + align:start position:0% +zero uh oh it is not Theta I got to be + + + align:start position:0% +zero uh oh it is not Theta I got to be +bigger than + + align:start position:0% +bigger than + + + align:start position:0% +bigger than +zero in + + align:start position:0% +zero in + + + align:start position:0% +zero in +fact this grows more slowly than that + + align:start position:0% +fact this grows more slowly than that + + + align:start position:0% +fact this grows more slowly than that +strictly more + + align:start position:0% +strictly more + + + align:start position:0% +strictly more +slowly all right a little more slowly + + align:start position:0% +slowly all right a little more slowly + + + align:start position:0% +slowly all right a little more slowly +but strictly more + + align:start position:0% +but strictly more + + + align:start position:0% +but strictly more +slowly all right if I use for an an + + align:start position:0% +slowly all right if I use for an an + + + align:start position:0% +slowly all right if I use for an an +algorithm if you want to say the + + align:start position:0% +algorithm if you want to say the + + + align:start position:0% +algorithm if you want to say the +algorithm runs in quadratic time namely + + align:start position:0% +algorithm runs in quadratic time namely + + + align:start position:0% +algorithm runs in quadratic time namely +at least quadratic time and at most + + align:start position:0% +at least quadratic time and at most + + + align:start position:0% +at least quadratic time and at most +quadratic time then you'd say t of n is + + align:start position:0% +quadratic time then you'd say t of n is + + + align:start position:0% +quadratic time then you'd say t of n is +Theta of + + align:start position:0% +Theta of + + + align:start position:0% +Theta of +n^2 so let me write + + align:start position:0% + + + + align:start position:0% + +that so T of Nal Theta + + align:start position:0% +that so T of Nal Theta + + + align:start position:0% +that so T of Nal Theta +N2 + + align:start position:0% +N2 + + + align:start position:0% +N2 +means T + + align:start position:0% +means T + + + align:start position:0% +means T +grows + + align:start position:0% + + + + align:start position:0% + +quadratically in + + align:start position:0% +quadratically in + + + align:start position:0% +quadratically in +N both upper and lower + + align:start position:0% +N both upper and lower + + + align:start position:0% +N both upper and lower +bound okay + + align:start position:0% + + + + align:start position:0% + +so and for these three guys to + + align:start position:0% +so and for these three guys to + + + align:start position:0% +so and for these three guys to +summarize + + align:start position:0% +summarize + + + align:start position:0% +summarize +that's so you can keep track of them + + align:start position:0% +that's so you can keep track of them + + + align:start position:0% +that's so you can keep track of them +pretty + + align:start position:0% + + + + align:start position:0% + +simply + + align:start position:0% +simply + + + align:start position:0% +simply +o + + align:start position:0% +o + + + align:start position:0% +o +means less than or equal Omega means + + align:start position:0% +means less than or equal Omega means + + + align:start position:0% +means less than or equal Omega means +greater than or equal Theta means equal + + align:start position:0% +greater than or equal Theta means equal + + + align:start position:0% +greater than or equal Theta means equal +up to constant factors + + align:start position:0% + + + + align:start position:0% + +now there's two more symbols + + align:start position:0% +now there's two more symbols + + + align:start position:0% +now there's two more symbols +here and they correspond very naturally + + align:start position:0% +here and they correspond very naturally + + + align:start position:0% +here and they correspond very naturally +to this setup what two symbols are + + align:start position:0% +to this setup what two symbols are + + + align:start position:0% +to this setup what two symbols are +missing from here that would you + + align:start position:0% +missing from here that would you + + + align:start position:0% +missing from here that would you +naturally add to + + align:start position:0% +naturally add to + + + align:start position:0% +naturally add to +here yeah less than and greater than so + + align:start position:0% +here yeah less than and greater than so + + + align:start position:0% +here yeah less than and greater than so +less than is little + + align:start position:0% +less than is little + + + align:start position:0% +less than is little +o greater than is little + + align:start position:0% +o greater than is little + + + align:start position:0% +o greater than is little +Omega and less than means it's less than + + align:start position:0% +Omega and less than means it's less than + + + align:start position:0% +Omega and less than means it's less than +or equal but not equal and this means + + align:start position:0% +or equal but not equal and this means + + + align:start position:0% +or equal but not equal and this means +greater than or equal not + + align:start position:0% +greater than or equal not + + + align:start position:0% +greater than or equal not +equal and let me put them up over here + + align:start position:0% +equal and let me put them up over here + + + align:start position:0% +equal and let me put them up over here +and give you the formal + + align:start position:0% + + + + align:start position:0% + +definitions + + align:start position:0% + + + + align:start position:0% + +racer okay so little o + + align:start position:0% + + + + align:start position:0% + +is we have f ofx equals little of G of + + align:start position:0% +is we have f ofx equals little of G of + + + align:start position:0% +is we have f ofx equals little of G of +x if the + + align:start position:0% + + + + align:start position:0% + +limit of f ofx over g + + align:start position:0% + + + + align:start position:0% + +ofx equals zero so f is growing strictly + + align:start position:0% +ofx equals zero so f is growing strictly + + + align:start position:0% +ofx equals zero so f is growing strictly +smaller than G so that when I take the + + align:start position:0% +smaller than G so that when I take the + + + align:start position:0% +smaller than G so that when I take the +ratio the limit goes to zero and the + + align:start position:0% +ratio the limit goes to zero and the + + + align:start position:0% +ratio the limit goes to zero and the +reverse is little + + align:start position:0% + + + + align:start position:0% + +Omega and we say that f ofx is little + + align:start position:0% +Omega and we say that f ofx is little + + + align:start position:0% +Omega and we say that f ofx is little +Omega whoops of G of + + align:start position:0% +Omega whoops of G of + + + align:start position:0% +Omega whoops of G of +x if this is + + align:start position:0% +x if this is + + + align:start position:0% +x if this is +infinity because now f is growing + + align:start position:0% +infinity because now f is growing + + + align:start position:0% +infinity because now f is growing +strictly faster than G so I take the + + align:start position:0% +strictly faster than G so I take the + + + align:start position:0% +strictly faster than G so I take the +limit of the ratio and it goes to + + align:start position:0% +limit of the ratio and it goes to + + + align:start position:0% +limit of the ratio and it goes to +Infinity all right so we can do some + + align:start position:0% +Infinity all right so we can do some + + + align:start position:0% +Infinity all right so we can do some +simple examples + + align:start position:0% +simple examples + + + align:start position:0% +simple examples +then we're almost done with all this + + align:start position:0% + + + + align:start position:0% + +notation what about this one X over Ln + + align:start position:0% +notation what about this one X over Ln + + + align:start position:0% +notation what about this one X over Ln +of X we just looked at + + align:start position:0% +of X we just looked at + + + align:start position:0% +of X we just looked at +it and x what symbol do I put + + align:start position:0% + + + + align:start position:0% + +there what symbols missing + + align:start position:0% +there what symbols missing + + + align:start position:0% +there what symbols missing +here little little o this grows strictly + + align:start position:0% +here little little o this grows strictly + + + align:start position:0% +here little little o this grows strictly +smaller than that if I took the ratio + + align:start position:0% +smaller than that if I took the ratio + + + align:start position:0% +smaller than that if I took the ratio +and I took the limit we got zero so + + align:start position:0% +and I took the limit we got zero so + + + align:start position:0% +and I took the limit we got zero so +that's little + + align:start position:0% +that's little + + + align:start position:0% +that's little +o + + align:start position:0% +o + + + align:start position:0% +o +okay is this true X over 100 is that + + align:start position:0% +okay is this true X over 100 is that + + + align:start position:0% +okay is this true X over 100 is that +little o of + + align:start position:0% + + + + align:start position:0% + +x + + align:start position:0% +x + + + align:start position:0% +x +no the limit of the ratio is 1 over 100 + + align:start position:0% +no the limit of the ratio is 1 over 100 + + + align:start position:0% +no the limit of the ratio is 1 over 100 +that's bigger than zero constants don't + + align:start position:0% +that's bigger than zero constants don't + + + align:start position:0% +that's bigger than zero constants don't +matter all right so what symbol would go + + align:start position:0% +matter all right so what symbol would go + + + align:start position:0% +matter all right so what symbol would go +here Theta goes here good also Big O and + + align:start position:0% +here Theta goes here good also Big O and + + + align:start position:0% +here Theta goes here good also Big O and +big Omega but Theta captures + + align:start position:0% +big Omega but Theta captures + + + align:start position:0% +big Omega but Theta captures +everything all right what symbol goes + + align:start position:0% +everything all right what symbol goes + + + align:start position:0% +everything all right what symbol goes +here X2 equals something + + align:start position:0% +here X2 equals something + + + align:start position:0% +here X2 equals something +x what symbol goes + + align:start position:0% +x what symbol goes + + + align:start position:0% +x what symbol goes +there little Omega you could would also + + align:start position:0% +there little Omega you could would also + + + align:start position:0% +there little Omega you could would also +be true to put big Omega but little + + align:start position:0% +be true to put big Omega but little + + + align:start position:0% +be true to put big Omega but little +Omega tells you more because the limit + + align:start position:0% +Omega tells you more because the limit + + + align:start position:0% +Omega tells you more because the limit +of x2x goes to + + align:start position:0% +of x2x goes to + + + align:start position:0% +of x2x goes to +Infinity okay any questions about these + + align:start position:0% +Infinity okay any questions about these + + + align:start position:0% +Infinity okay any questions about these +things so you know a natural thing on + + align:start position:0% +things so you know a natural thing on + + + align:start position:0% +things so you know a natural thing on +the midterm is we do some of that for + + align:start position:0% +the midterm is we do some of that for + + + align:start position:0% +the midterm is we do some of that for +example all right you'll certainly see + + align:start position:0% +example all right you'll certainly see + + + align:start position:0% +example all right you'll certainly see +some of that on + + align:start position:0% +some of that on + + + align:start position:0% +some of that on +homework you might see some of that on + + align:start position:0% +homework you might see some of that on + + + align:start position:0% +homework you might see some of that on +the test you'll certainly see all this + + align:start position:0% +the test you'll certainly see all this + + + align:start position:0% +the test you'll certainly see all this +stuff little Omega not very often in + + align:start position:0% +stuff little Omega not very often in + + + align:start position:0% +stuff little Omega not very often in +6046 and later algorithms courses but + + align:start position:0% +6046 and later algorithms courses but + + + align:start position:0% +6046 and later algorithms courses but +all the rest you'll see + + align:start position:0% +all the rest you'll see + + + align:start position:0% +all the rest you'll see +there any + + align:start position:0% +there any + + + align:start position:0% +there any +questions all right now I'm going to + + align:start position:0% +questions all right now I'm going to + + + align:start position:0% +questions all right now I'm going to +show you something that is sort of + + align:start position:0% +show you something that is sort of + + + align:start position:0% +show you something that is sort of +scary yeah + + align:start position:0% + + + + align:start position:0% + +uh which + + align:start position:0% + + + + align:start position:0% + +equals little Omega it corresponds to a + + align:start position:0% +equals little Omega it corresponds to a + + + align:start position:0% +equals little Omega it corresponds to a +greater than which means a greater than + + align:start position:0% +greater than which means a greater than + + + align:start position:0% +greater than which means a greater than +or equal to but not an equal + + align:start position:0% +or equal to but not an equal + + + align:start position:0% +or equal to but not an equal +to and the way we can see that is + + align:start position:0% +to and the way we can see that is + + + align:start position:0% +to and the way we can see that is +looking at the definitions + + align:start position:0% + + + + align:start position:0% + +here and the greater than or equal to is + + align:start position:0% +here and the greater than or equal to is + + + align:start position:0% +here and the greater than or equal to is +the big Omega + + align:start position:0% +the big Omega + + + align:start position:0% +the big Omega +and that just + + align:start position:0% +and that just + + + align:start position:0% +and that just +says you're bigger than + + align:start position:0% +says you're bigger than + + + align:start position:0% +says you're bigger than +zero uh let's see right so I'm bigger + + align:start position:0% +zero uh let's see right so I'm bigger + + + align:start position:0% +zero uh let's see right so I'm bigger +than or equal to is Omega but I'm not + + align:start position:0% +than or equal to is Omega but I'm not + + + align:start position:0% +than or equal to is Omega but I'm not +equal to which is + + align:start position:0% +equal to which is + + + align:start position:0% +equal to which is +Theta so if I know that I'm this but not + + align:start position:0% +Theta so if I know that I'm this but not + + + align:start position:0% +Theta so if I know that I'm this but not +that the only conclusion is that I'm + + align:start position:0% +that the only conclusion is that I'm + + + align:start position:0% +that the only conclusion is that I'm +Infinity in the + + align:start position:0% +Infinity in the + + + align:start position:0% +Infinity in the +ratio all right so that's another way of + + align:start position:0% +ratio all right so that's another way of + + + align:start position:0% +ratio all right so that's another way of +saying it that's why + + align:start position:0% +saying it that's why + + + align:start position:0% +saying it that's why +any other + + align:start position:0% + + + + align:start position:0% + +questions all right now I'm going to + + align:start position:0% +questions all right now I'm going to + + + align:start position:0% +questions all right now I'm going to +show you something that is commonly done + + align:start position:0% +show you something that is commonly done + + + align:start position:0% +show you something that is commonly done +and that many students will attempt to + + align:start position:0% +and that many students will attempt to + + + align:start position:0% +and that many students will attempt to +do after seeing this notation because a + + align:start position:0% +do after seeing this notation because a + + + align:start position:0% +do after seeing this notation because a +notation is pretty simple take your + + align:start position:0% +notation is pretty simple take your + + + align:start position:0% +notation is pretty simple take your +limits everything you know goes fine + + align:start position:0% +limits everything you know goes fine + + + align:start position:0% +limits everything you know goes fine +then you start you know cruising along + + align:start position:0% +then you start you know cruising along + + + align:start position:0% +then you start you know cruising along +with it so now I'm going to show you how + + align:start position:0% +with it so now I'm going to show you how + + + align:start position:0% +with it so now I'm going to show you how +to prove something that's false using + + align:start position:0% +to prove something that's false using + + + align:start position:0% +to prove something that's false using +this notation in a way that people often + + align:start position:0% +this notation in a way that people often + + + align:start position:0% +this notation in a way that people often +do and the hope is by showing you you + + align:start position:0% +do and the hope is by showing you you + + + align:start position:0% +do and the hope is by showing you you +won't do it + + align:start position:0% +won't do it + + + align:start position:0% +won't do it +it will confuse you which is why + + align:start position:0% +it will confuse you which is why + + + align:start position:0% +it will confuse you which is why +sometimes we worry about showing you + + align:start position:0% + + + + align:start position:0% + +but let F of i f of + + align:start position:0% +but let F of i f of + + + align:start position:0% +but let F of i f of +n equal the sum I = 1 to n of + + align:start position:0% +n equal the sum I = 1 to n of + + + align:start position:0% +n equal the sum I = 1 to n of +I now we all know what that is + + align:start position:0% +I now we all know what that is + + + align:start position:0% +I now we all know what that is +right all right so I'm going to prove to + + align:start position:0% +right all right so I'm going to prove to + + + align:start position:0% +right all right so I'm going to prove to +you + + align:start position:0% + + + + align:start position:0% + +that F of n is O of + + align:start position:0% + + + + align:start position:0% + +n now what really what what should be + + align:start position:0% +n now what really what what should be + + + align:start position:0% +n now what really what what should be +here instead of + + align:start position:0% +here instead of + + + align:start position:0% +here instead of +n n s so it can't n squ can't be o of n + + align:start position:0% +n n s so it can't n squ can't be o of n + + + align:start position:0% +n n s so it can't n squ can't be o of n +so this can't be true all right well + + align:start position:0% +so this can't be true all right well + + + align:start position:0% +so this can't be true all right well +let's see how we do + + align:start position:0% +let's see how we do + + + align:start position:0% +let's see how we do +it all right so the false + + align:start position:0% + + + + align:start position:0% + +proof is by induction + + align:start position:0% + + + + align:start position:0% + +on + + align:start position:0% +on + + + align:start position:0% +on +N my induction + + align:start position:0% +N my induction + + + align:start position:0% +N my induction +hypothesis is p of n is going to be that + + align:start position:0% +hypothesis is p of n is going to be that + + + align:start position:0% +hypothesis is p of n is going to be that +F of + + align:start position:0% +F of + + + align:start position:0% +F of +n is O of + + align:start position:0% +n is O of + + + align:start position:0% +n is O of +n right that's what we when we want to + + align:start position:0% +n right that's what we when we want to + + + align:start position:0% +n right that's what we when we want to +prove something by induction typically + + align:start position:0% +prove something by induction typically + + + align:start position:0% +prove something by induction typically +that's what you do becomes the induction + + align:start position:0% +that's what you do becomes the induction + + + align:start position:0% +that's what you do becomes the induction +hypothesis let's look at the base + + align:start position:0% + + + + align:start position:0% + +case well well F of + + align:start position:0% +case well well F of + + + align:start position:0% +case well well F of +one is + + align:start position:0% +one is + + + align:start position:0% +one is +one and one is O of one + + align:start position:0% +one and one is O of one + + + align:start position:0% +one and one is O of one +surely right even 10 was O of + + align:start position:0% +surely right even 10 was O of + + + align:start position:0% +surely right even 10 was O of +one + + align:start position:0% + + + + align:start position:0% + +okay all right now we do the inductive + + align:start position:0% +okay all right now we do the inductive + + + align:start position:0% +okay all right now we do the inductive +step + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% +we + + + align:start position:0% +we +assume PN is + + align:start position:0% +assume PN is + + + align:start position:0% +assume PN is +true to + + align:start position:0% +true to + + + align:start position:0% +true to +prove PN + one is + + align:start position:0% + + + + align:start position:0% + +true well + + align:start position:0% +true well + + + align:start position:0% +true well +PN means that F of n is O of + + align:start position:0% +PN means that F of n is O of + + + align:start position:0% +PN means that F of n is O of +n now I look at F of n + + + align:start position:0% +n now I look at F of n + + + + align:start position:0% +n now I look at F of n + +one that equals the sum of the first n+ + + align:start position:0% +one that equals the sum of the first n+ + + + align:start position:0% +one that equals the sum of the first n+ +one number so that'll be f n plus n + + align:start position:0% +one number so that'll be f n plus n + + + align:start position:0% +one number so that'll be f n plus n ++1 the induction hypothesis says this is + + align:start position:0% ++1 the induction hypothesis says this is + + + align:start position:0% ++1 the induction hypothesis says this is +O of + + align:start position:0% +O of + + + align:start position:0% +O of +n clearly this is O of + + align:start position:0% + + + + align:start position:0% + +n well I got o of n plus o of n that's + + align:start position:0% +n well I got o of n plus o of n that's + + + align:start position:0% +n well I got o of n plus o of n that's +at most twice o of + + align:start position:0% + + + + align:start position:0% + +N and constants don't matter so that's o + + align:start position:0% +N and constants don't matter so that's o + + + align:start position:0% +N and constants don't matter so that's o +of n + + align:start position:0% + + + + align:start position:0% + +all right this + + align:start position:0% +all right this + + + align:start position:0% +all right this +should begin to cause Panic you know I + + align:start position:0% +should begin to cause Panic you know I + + + align:start position:0% +should begin to cause Panic you know I +don't is induction wrong what's going on + + align:start position:0% +don't is induction wrong what's going on + + + align:start position:0% +don't is induction wrong what's going on +with a big + + align:start position:0% +with a big + + + align:start position:0% +with a big +O you will see this done all the time + + align:start position:0% +O you will see this done all the time + + + align:start position:0% +O you will see this done all the time +people will will do this kind of an + + align:start position:0% +people will will do this kind of an + + + align:start position:0% +people will will do this kind of an +argument looks pretty good + + align:start position:0% +argument looks pretty good + + + align:start position:0% +argument looks pretty good +right can anybody see + + align:start position:0% +right can anybody see + + + align:start position:0% +right can anybody see +where I got off track this is a really + + align:start position:0% +where I got off track this is a really + + + align:start position:0% +where I got off track this is a really +hard one to figure out where things went + + align:start position:0% +hard one to figure out where things went + + + align:start position:0% +hard one to figure out where things went +wrong yeah + + align:start position:0% + + + + align:start position:0% + +great that's a great observation ASM + + align:start position:0% +great that's a great observation ASM + + + align:start position:0% +great that's a great observation ASM +totic + + align:start position:0% +totic + + + align:start position:0% +totic +notation only works for functions now + + align:start position:0% +notation only works for functions now + + + align:start position:0% +notation only works for functions now +here when we say one is O of one well + + align:start position:0% +here when we say one is O of one well + + + align:start position:0% +here when we say one is O of one well +you could think of it as F ofx being one + + align:start position:0% +you could think of it as F ofx being one + + + align:start position:0% +you could think of it as F ofx being one +the function and so forth so that's okay + + align:start position:0% +the function and so forth so that's okay + + + align:start position:0% +the function and so forth so that's okay +that's a great point now let's figure + + align:start position:0% +that's a great point now let's figure + + + align:start position:0% +that's a great point now let's figure +out using that how we got in trouble + + align:start position:0% +out using that how we got in trouble + + + align:start position:0% +out using that how we got in trouble +we're not quite done yet that's a great + + align:start position:0% +we're not quite done yet that's a great + + + align:start position:0% +we're not quite done yet that's a great +observation but how does where's the + + align:start position:0% +observation but how does where's the + + + align:start position:0% +observation but how does where's the +step that's + + align:start position:0% + + + + align:start position:0% + +wrong uh no 2 * o of n is O of n if I + + align:start position:0% +wrong uh no 2 * o of n is O of n if I + + + align:start position:0% +wrong uh no 2 * o of n is O of n if I +have a function that's f is O of G twice + + align:start position:0% +have a function that's f is O of G twice + + + align:start position:0% +have a function that's f is O of G twice +f is O of G + + align:start position:0% + + + + align:start position:0% + +yeah is it so what what's the problem + + align:start position:0% + + + + align:start position:0% + +now well F of n plus one this statement + + align:start position:0% +now well F of n plus one this statement + + + align:start position:0% +now well F of n plus one this statement +is true because F of n + 1 is the sum of + + align:start position:0% +is true because F of n + 1 is the sum of + + + align:start position:0% +is true because F of n + 1 is the sum of +I = 1 to n + 1 of I that's 1 + 2 + n + n + + align:start position:0% +I = 1 to n + 1 of I that's 1 + 2 + n + n + + + align:start position:0% +I = 1 to n + 1 of I that's 1 + 2 + n + n ++ 1 and this is f of + + align:start position:0% ++ 1 and this is f of + + + align:start position:0% ++ 1 and this is f of +n so that's + + align:start position:0% + + + + align:start position:0% + +okay yeah + + align:start position:0% + + + + align:start position:0% + +yeah you know uh you're getting + + align:start position:0% +yeah you know uh you're getting + + + align:start position:0% +yeah you know uh you're getting +closer yeah I've only got a yeah sort of + + align:start position:0% +closer yeah I've only got a yeah sort of + + + align:start position:0% +closer yeah I've only got a yeah sort of +that's a little flaky because I've just + + align:start position:0% +that's a little flaky because I've just + + + align:start position:0% +that's a little flaky because I've just +got a single value saying it's O of one + + align:start position:0% +got a single value saying it's O of one + + + align:start position:0% +got a single value saying it's O of one +but we sort of argued before that 10 was + + align:start position:0% +but we sort of argued before that 10 was + + + align:start position:0% +but we sort of argued before that 10 was +O of one now really there's a function + + align:start position:0% +O of one now really there's a function + + + align:start position:0% +O of one now really there's a function +behind here that matters so you're on + + align:start position:0% +behind here that matters so you're on + + + align:start position:0% +behind here that matters so you're on +the right Trail but there's an even + + align:start position:0% +the right Trail but there's an even + + + align:start position:0% +the right Trail but there's an even +bigger Whopper hiding + + align:start position:0% +bigger Whopper hiding + + + align:start position:0% +bigger Whopper hiding +yeah oh yeah this is really really + + align:start position:0% +yeah oh yeah this is really really + + + align:start position:0% +yeah oh yeah this is really really +bad all right so now explain to me why + + align:start position:0% +bad all right so now explain to me why + + + align:start position:0% +bad all right so now explain to me why +this is really bad what I did + + align:start position:0% + + + + align:start position:0% + +here yeah and why isn't this looks like + + align:start position:0% +here yeah and why isn't this looks like + + + align:start position:0% +here yeah and why isn't this looks like +a function why isn't it a + + align:start position:0% + + + + align:start position:0% + +function it's not but it looks like one + + align:start position:0% +function it's not but it looks like one + + + align:start position:0% +function it's not but it looks like one +F of n sure looks like one why is it not + + align:start position:0% +F of n sure looks like one why is it not + + + align:start position:0% +F of n sure looks like one why is it not +a function when it's sitting in this + + align:start position:0% +a function when it's sitting in this + + + align:start position:0% +a function when it's sitting in this +thing because P of + + align:start position:0% +thing because P of + + + align:start position:0% +thing because P of +n right because I've fixed the value of + + align:start position:0% +n right because I've fixed the value of + + + align:start position:0% +n right because I've fixed the value of +n + + align:start position:0% +n + + + align:start position:0% +n +here and so this is now just to scaler + + align:start position:0% +here and so this is now just to scaler + + + align:start position:0% +here and so this is now just to scaler +in fact you know I could State the + + align:start position:0% +in fact you know I could State the + + + align:start position:0% +in fact you know I could State the +following F of a + + align:start position:0% + + + + align:start position:0% + +million right is O of one because this + + align:start position:0% +million right is O of one because this + + + align:start position:0% +million right is O of one because this +is really some function H ofx that + + align:start position:0% +is really some function H ofx that + + + align:start position:0% +is really some function H ofx that +always is this value it's a difference + + align:start position:0% +always is this value it's a difference + + + align:start position:0% +always is this value it's a difference +between a scalar and a function and this + + align:start position:0% +between a scalar and a function and this + + + align:start position:0% +between a scalar and a function and this +is just so nasty looking because we see + + align:start position:0% +is just so nasty looking because we see + + + align:start position:0% +is just so nasty looking because we see +F ofn that's a function but you can + + align:start position:0% +F ofn that's a function but you can + + + align:start position:0% +F ofn that's a function but you can +never use Big O in a predicate + + align:start position:0% +never use Big O in a predicate + + + align:start position:0% +never use Big O in a predicate +right because we've lost the function + + align:start position:0% +right because we've lost the function + + + align:start position:0% +right because we've lost the function +here this is just the F evalu at n + + align:start position:0% +here this is just the F evalu at n + + + align:start position:0% +here this is just the F evalu at n +period the only that single instance is + + align:start position:0% +period the only that single instance is + + + align:start position:0% +period the only that single instance is +all that's happened here it's not a + + align:start position:0% +all that's happened here it's not a + + + align:start position:0% +all that's happened here it's not a +function + + align:start position:0% +function + + + align:start position:0% +function +anymore all right if you know if we had + + align:start position:0% +anymore all right if you know if we had + + + align:start position:0% +anymore all right if you know if we had +FN of X or something that might be okay + + align:start position:0% +FN of X or something that might be okay + + + align:start position:0% +FN of X or something that might be okay +but there's no function left all right + + align:start position:0% +but there's no function left all right + + + align:start position:0% +but there's no function left all right +so never ever use asymptotic notation + + align:start position:0% +so never ever use asymptotic notation + + + align:start position:0% +so never ever use asymptotic notation +with inductive proofs because you will + + align:start position:0% +with inductive proofs because you will + + + align:start position:0% +with inductive proofs because you will +just invariably stick Big O into your + + align:start position:0% +just invariably stick Big O into your + + + align:start position:0% +just invariably stick Big O into your +predicate and you can prove all sorts of + + align:start position:0% +predicate and you can prove all sorts of + + + align:start position:0% +predicate and you can prove all sorts of +false things once you do + + align:start position:0% +false things once you do + + + align:start position:0% +false things once you do +that + + align:start position:0% +that + + + align:start position:0% +that +okay all right never use ASM totic + + align:start position:0% +okay all right never use ASM totic + + + align:start position:0% +okay all right never use ASM totic +notation in induction or predicates + + align:start position:0% +notation in induction or predicates + + + align:start position:0% +notation in induction or predicates +thanks \ No newline at end of file diff --git a/XQKV-hpsurs.txt b/XQKV-hpsurs.txt new file mode 100644 index 0000000000000000000000000000000000000000..d710d804df79dafae4efcd9f655b457df98603c3 --- /dev/null +++ b/XQKV-hpsurs.txt @@ -0,0 +1,3547 @@ +align:start position:0% + +expectation + + align:start position:0% +expectation + + + align:start position:0% +expectation +values + + align:start position:0% + + + + align:start position:0% + +expectation values of + + align:start position:0% +expectation values of + + + align:start position:0% +expectation values of +operators + + align:start position:0% + + + + align:start position:0% + +operators so this is in a sense one of + + align:start position:0% +operators so this is in a sense one of + + + align:start position:0% +operators so this is in a sense one of +our first steps that we're going to take + + align:start position:0% +our first steps that we're going to take + + + align:start position:0% +our first steps that we're going to take +towards the interpretation of quantum + + align:start position:0% +towards the interpretation of quantum + + + align:start position:0% +towards the interpretation of quantum +mechanics we've had already that the way + + align:start position:0% +mechanics we've had already that the way + + + align:start position:0% +mechanics we've had already that the way +function tells you about probabilities + + align:start position:0% +function tells you about probabilities + + + align:start position:0% +function tells you about probabilities +but that's not quite enough to have the + + align:start position:0% +but that's not quite enough to have the + + + align:start position:0% +but that's not quite enough to have the +full interpretation of what we're doing + + align:start position:0% +full interpretation of what we're doing + + + align:start position:0% +full interpretation of what we're doing +so let's uh think of operators and + + align:start position:0% +so let's uh think of operators and + + + align:start position:0% +so let's uh think of operators and +expectation values that we can motivate + + align:start position:0% +expectation values that we can motivate + + + align:start position:0% +expectation values that we can motivate +so for example if you have a random + + align:start position:0% + + + + align:start position:0% + +variable + + align:start position:0% +variable + + + align:start position:0% +variable +variable + + align:start position:0% +variable + + + align:start position:0% +variable +q that can take values + + align:start position:0% + + + + align:start position:0% + +so this could be a coin that can take + + align:start position:0% +so this could be a coin that can take + + + align:start position:0% +so this could be a coin that can take +values head and tail could be a pair of + + align:start position:0% +values head and tail could be a pair of + + + align:start position:0% +values head and tail could be a pair of +D that takes many values of can take + + align:start position:0% +D that takes many values of can take + + + align:start position:0% +D that takes many values of can take +values in the + + align:start position:0% + + + + align:start position:0% + +set q1 up to + + align:start position:0% +set q1 up to + + + align:start position:0% +set q1 up to +qn with + + align:start position:0% + + + + align:start position:0% + +probabilities + + align:start position:0% + + + + align:start position:0% + +abilities p + + align:start position:0% +abilities p + + + align:start position:0% +abilities p +P1 up to + + align:start position:0% + + + + align:start position:0% + +PN then in statistics or in + + align:start position:0% +PN then in statistics or in + + + align:start position:0% +PN then in statistics or in +8044 uh you would say that this variable + + align:start position:0% +8044 uh you would say that this variable + + + align:start position:0% +8044 uh you would say that this variable +this random variable has an expectation + + align:start position:0% +this random variable has an expectation + + + align:start position:0% +this random variable has an expectation +value and the expectation + + align:start position:0% +value and the expectation + + + align:start position:0% +value and the expectation +value denoted by this um + + align:start position:0% +value denoted by this um + + + align:start position:0% +value denoted by this um +angular symbols over here left and right + + align:start position:0% +angular symbols over here left and right + + + align:start position:0% +angular symbols over here left and right +um it's given by the sum over I IAL 1 to + + align:start position:0% +um it's given by the sum over I IAL 1 to + + + align:start position:0% +um it's given by the sum over I IAL 1 to +n of the possible values the random + + align:start position:0% +n of the possible values the random + + + align:start position:0% +n of the possible values the random +variable can take times the + + align:start position:0% +variable can take times the + + + align:start position:0% +variable can take times the +probabilities it's a + + align:start position:0% +probabilities it's a + + + align:start position:0% +probabilities it's a +definition that makes sense and it's + + align:start position:0% +definition that makes sense and it's + + + align:start position:0% +definition that makes sense and it's +thought to be this expectation value is + + align:start position:0% +thought to be this expectation value is + + + align:start position:0% +thought to be this expectation value is +the expected value or average value that + + align:start position:0% +the expected value or average value that + + + align:start position:0% +the expected value or average value that +you would obtain if you did the + + align:start position:0% +you would obtain if you did the + + + align:start position:0% +you would obtain if you did the +experiment of tossing the random + + align:start position:0% +experiment of tossing the random + + + align:start position:0% +experiment of tossing the random +variable many times for each value of + + align:start position:0% +variable many times for each value of + + + align:start position:0% +variable many times for each value of +the random variable you multiply by the + + align:start position:0% +the random variable you multiply by the + + + align:start position:0% +the random variable you multiply by the +probability and that's the number you + + align:start position:0% +probability and that's the number you + + + align:start position:0% +probability and that's the number you +expect to + + align:start position:0% +expect to + + + align:start position:0% +expect to +get so in a Quantum system we follow + + align:start position:0% +get so in a Quantum system we follow + + + align:start position:0% +get so in a Quantum system we follow +this analogy very closely so what do we + + align:start position:0% +this analogy very closely so what do we + + + align:start position:0% +this analogy very closely so what do we +have in a Quantum system in a Quantum + + align:start position:0% +have in a Quantum system in a Quantum + + + align:start position:0% +have in a Quantum system in a Quantum +system + + align:start position:0% + + + + align:start position:0% + +system you have that s + + align:start position:0% +system you have that s + + + align:start position:0% +system you have that s +star of + + align:start position:0% +star of + + + align:start position:0% +star of +x and t now SI of x and t + + align:start position:0% +x and t now SI of x and t + + + align:start position:0% +x and t now SI of x and t +DX is the + + align:start position:0% +DX is the + + + align:start position:0% +DX is the +probability + + align:start position:0% + + + + align:start position:0% + +probability that the + + align:start position:0% + + + + align:start position:0% + +particle + + align:start position:0% +particle + + + align:start position:0% +particle +particle is + + align:start position:0% +particle is + + + align:start position:0% +particle is +in X comma x + + + align:start position:0% +in X comma x + + + + align:start position:0% +in X comma x + +DX okay so that's the probability that + + align:start position:0% +DX okay so that's the probability that + + + align:start position:0% +DX okay so that's the probability that +the particle is going to be found + + align:start position:0% +the particle is going to be found + + + align:start position:0% +the particle is going to be found +between X and X Plus DX the position of + + align:start position:0% +between X and X Plus DX the position of + + + align:start position:0% +between X and X Plus DX the position of +this particle is like a random variable + + align:start position:0% +this particle is like a random variable + + + align:start position:0% +this particle is like a random variable +you never know where you're going to + + align:start position:0% +you never know where you're going to + + + align:start position:0% +you never know where you're going to +find it but it has different + + align:start position:0% +find it but it has different + + + align:start position:0% +find it but it has different +probabilities to find it so we could now + + align:start position:0% +probabilities to find it so we could now + + + align:start position:0% +probabilities to find it so we could now +Define in complete analogy to here the + + align:start position:0% +Define in complete analogy to here the + + + align:start position:0% +Define in complete analogy to here the +expectation value of the position + + align:start position:0% +expectation value of the position + + + align:start position:0% +expectation value of the position +operator or the expectation value of the + + align:start position:0% +operator or the expectation value of the + + + align:start position:0% +operator or the expectation value of the +position + + align:start position:0% +position + + + align:start position:0% +position +expectation + + align:start position:0% +expectation + + + align:start position:0% +expectation +value of x hat or the position and say + + align:start position:0% +value of x hat or the position and say + + + align:start position:0% +value of x hat or the position and say +well I'm going to do exactly what I'm + + align:start position:0% +well I'm going to do exactly what I'm + + + align:start position:0% +well I'm going to do exactly what I'm +have here I will + + align:start position:0% +have here I will + + + align:start position:0% +have here I will +sum the products of the position times + + align:start position:0% +sum the products of the position times + + + align:start position:0% +sum the products of the position times +the probability for the position so I + + align:start position:0% +the probability for the position so I + + + align:start position:0% +the probability for the position so I +have to do it as an + + align:start position:0% + + + + align:start position:0% + +integral and in this integral I have to + + align:start position:0% +integral and in this integral I have to + + + align:start position:0% +integral and in this integral I have to +multiply the + + align:start position:0% +multiply the + + + align:start position:0% +multiply the +position times the + + align:start position:0% + + + + align:start position:0% + +probability for the + + align:start position:0% + + + + align:start position:0% + +position so the probability that it is + + align:start position:0% +position so the probability that it is + + + align:start position:0% +position so the probability that it is +takes a value + + align:start position:0% +takes a value + + + align:start position:0% +takes a value +X basically or that is in the + + align:start position:0% +X basically or that is in the + + + align:start position:0% +X basically or that is in the +interval DX X about X is this quantity + + align:start position:0% +interval DX X about X is this quantity + + + align:start position:0% +interval DX X about X is this quantity +and that's the position that you get + + align:start position:0% +and that's the position that you get + + + align:start position:0% +and that's the position that you get +when you estimate this probability so + + align:start position:0% +when you estimate this probability so + + + align:start position:0% +when you estimate this probability so +you must sum the values of the random + + align:start position:0% +you must sum the values of the random + + + align:start position:0% +you must sum the values of the random +variable times its + + align:start position:0% +variable times its + + + align:start position:0% +variable times its +probability and that is taken in quantum + + align:start position:0% +probability and that is taken in quantum + + + align:start position:0% +probability and that is taken in quantum +mechanics to be a + + align:start position:0% + + + + align:start position:0% + +definition we can def find the + + align:start position:0% +definition we can def find the + + + align:start position:0% +definition we can def find the +expectation value of x by this + + align:start position:0% +expectation value of x by this + + + align:start position:0% +expectation value of x by this +quantity and what does it mean + + align:start position:0% +quantity and what does it mean + + + align:start position:0% +quantity and what does it mean +experimentally it means that in quantum + + align:start position:0% +experimentally it means that in quantum + + + align:start position:0% +experimentally it means that in quantum +mechanics if you have a system + + align:start position:0% +mechanics if you have a system + + + align:start position:0% +mechanics if you have a system +represented by a wave function you + + align:start position:0% +represented by a wave function you + + + align:start position:0% +represented by a wave function you +should build many copies of the system + + align:start position:0% +should build many copies of the system + + + align:start position:0% +should build many copies of the system +100 copies of the system in all of these + + align:start position:0% +100 copies of the system in all of these + + + align:start position:0% +100 copies of the system in all of these +copies you measure the position and you + + align:start position:0% +copies you measure the position and you + + + align:start position:0% +copies you measure the position and you +make a table of the values that you + + align:start position:0% +make a table of the values that you + + + align:start position:0% +make a table of the values that you +measure the position and you measure + + align:start position:0% +measure the position and you measure + + + align:start position:0% +measure the position and you measure +them at the same time in the 100 copies + + align:start position:0% +them at the same time in the 100 copies + + + align:start position:0% +them at the same time in the 100 copies +there's an experimental list on each one + + align:start position:0% +there's an experimental list on each one + + + align:start position:0% +there's an experimental list on each one +and it measures the position of X you + + align:start position:0% +and it measures the position of X you + + + align:start position:0% +and it measures the position of X you +construct the table take the average and + + align:start position:0% +construct the table take the average and + + + align:start position:0% +construct the table take the average and +that's what this quantity should be + + align:start position:0% +that's what this quantity should be + + + align:start position:0% +that's what this quantity should be +telling + + align:start position:0% +telling + + + align:start position:0% +telling +you so this quantity as you can see may + + align:start position:0% +you so this quantity as you can see may + + + align:start position:0% +you so this quantity as you can see may +depend on + + align:start position:0% +depend on + + + align:start position:0% +depend on +time may depend on time + + align:start position:0% + + + + align:start position:0% + +but it does give + + align:start position:0% +but it does give + + + align:start position:0% +but it does give +you the interpretation of uh expected + + align:start position:0% +you the interpretation of uh expected + + + align:start position:0% +you the interpretation of uh expected +value coinciding with a system now the + + align:start position:0% +value coinciding with a system now the + + + align:start position:0% +value coinciding with a system now the +quantum mechanical system for which the + + align:start position:0% +quantum mechanical system for which the + + + align:start position:0% +quantum mechanical system for which the +position is not anymore a quantity that + + align:start position:0% +position is not anymore a quantity that + + + align:start position:0% +position is not anymore a quantity that +is well defined and it's always the same + + align:start position:0% +is well defined and it's always the same + + + align:start position:0% +is well defined and it's always the same +it's a random variable and each + + align:start position:0% +it's a random variable and each + + + align:start position:0% +it's a random variable and each +measurement can give you a different + + align:start position:0% +measurement can give you a different + + + align:start position:0% +measurement can give you a different +value of the position Quantum + + align:start position:0% +value of the position Quantum + + + align:start position:0% +value of the position Quantum +mechanically this is the expect + + align:start position:0% +mechanically this is the expect + + + align:start position:0% +mechanically this is the expect +value and the interpretation is again if + + align:start position:0% +value and the interpretation is again if + + + align:start position:0% +value and the interpretation is again if +you measure many times that is the value + + align:start position:0% +you measure many times that is the value + + + align:start position:0% +you measure many times that is the value +the average value you will + + align:start position:0% +the average value you will + + + align:start position:0% +the average value you will +observe but now we can do the same thing + + align:start position:0% +observe but now we can do the same thing + + + align:start position:0% +observe but now we can do the same thing +to understand + + align:start position:0% +to understand + + + align:start position:0% +to understand +the expectation values we can do it with + + align:start position:0% +the expectation values we can do it with + + + align:start position:0% +the expectation values we can do it with +a momentum and this is a little more + + align:start position:0% + + + + align:start position:0% + +nontrivial so we have also Al just like + + align:start position:0% +nontrivial so we have also Al just like + + + align:start position:0% +nontrivial so we have also Al just like +we said here that s star DX is the + + align:start position:0% +we said here that s star DX is the + + + align:start position:0% +we said here that s star DX is the +probability that the particle is in + + align:start position:0% +probability that the particle is in + + + align:start position:0% +probability that the particle is in +there you also have that + + align:start position:0% + + + + align:start position:0% + +fi of P + + align:start position:0% +fi of P + + + align:start position:0% +fi of P +Squared DP is the + + align:start position:0% +Squared DP is the + + + align:start position:0% +Squared DP is the +probability + + align:start position:0% +probability + + + align:start position:0% +probability +probability to find the + + align:start position:0% + + + + align:start position:0% + +particle + + align:start position:0% +particle + + + align:start position:0% +particle +particle with with + + align:start position:0% + + + + align:start position:0% + +momentum in the + + align:start position:0% + + + + align:start position:0% + +range P p+ + + align:start position:0% + + + + align:start position:0% + +DP so + + align:start position:0% +DP so + + + align:start position:0% +DP so +um how do we Define the expected value + + align:start position:0% +um how do we Define the expected value + + + align:start position:0% +um how do we Define the expected value +of the + + align:start position:0% +of the + + + align:start position:0% +of the +momentum the expected value of the + + align:start position:0% +momentum the expected value of the + + + align:start position:0% +momentum the expected value of the +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +would be given by again the + + align:start position:0% +would be given by again the + + + align:start position:0% +would be given by again the +sum of the random variable which is the + + align:start position:0% +sum of the random variable which is the + + + align:start position:0% +sum of the random variable which is the +momentum times the + + align:start position:0% +momentum times the + + + align:start position:0% +momentum times the +probability that you get that + + align:start position:0% + + + + align:start position:0% + +value so this is it is very + + align:start position:0% +value so this is it is very + + + align:start position:0% +value so this is it is very +analogous to this + + align:start position:0% + + + + align:start position:0% + +expression but it's now with momentum + + align:start position:0% + + + + align:start position:0% + +well this is a pretty nice thing but uh + + align:start position:0% +well this is a pretty nice thing but uh + + + align:start position:0% +well this is a pretty nice thing but uh +we can learn more about it by pushing + + align:start position:0% +we can learn more about it by pushing + + + align:start position:0% +we can learn more about it by pushing +the analogy more and you could say look + + align:start position:0% +the analogy more and you could say look + + + align:start position:0% +the analogy more and you could say look +uh this is perfect + + align:start position:0% +uh this is perfect + + + align:start position:0% +uh this is perfect +but it's all done in momentum space What + + align:start position:0% +but it's all done in momentum space What + + + align:start position:0% +but it's all done in momentum space What +would happen if you would try to do this + + align:start position:0% +would happen if you would try to do this + + + align:start position:0% +would happen if you would try to do this +in position + + align:start position:0% +in position + + + align:start position:0% +in position +space that is you know how F of p is + + align:start position:0% +space that is you know how F of p is + + + align:start position:0% +space that is you know how F of p is +related to P of X so write everything in + + align:start position:0% +related to P of X so write everything in + + + align:start position:0% +related to P of X so write everything in +terms of X I would like to see this + + align:start position:0% +terms of X I would like to see this + + + align:start position:0% +terms of X I would like to see this +formula in terms of X it would be a very + + align:start position:0% +formula in terms of X it would be a very + + + align:start position:0% +formula in terms of X it would be a very +good thing to have so let's try to do + + align:start position:0% +good thing to have so let's try to do + + + align:start position:0% +good thing to have so let's try to do +that + + align:start position:0% +that + + + align:start position:0% +that +so we have to do a little bit of work + + align:start position:0% +so we have to do a little bit of work + + + align:start position:0% +so we have to do a little bit of work +here with integral so but it's not so + + align:start position:0% +here with integral so but it's not so + + + align:start position:0% +here with integral so but it's not so +bad + + align:start position:0% +bad + + + align:start position:0% +bad +P five + + align:start position:0% +P five + + + align:start position:0% +P five +star of P + + align:start position:0% +star of P + + + align:start position:0% +star of P +5 of + + align:start position:0% +5 of + + + align:start position:0% +5 of +P + + align:start position:0% +P + + + align:start position:0% +P +DP and for this one you have to write it + + align:start position:0% +DP and for this one you have to write it + + + align:start position:0% +DP and for this one you have to write it +as an integral over some position so let + + align:start position:0% +as an integral over some position so let + + + align:start position:0% +as an integral over some position so let +me call it over position X Prime this + + align:start position:0% +me call it over position X Prime this + + + align:start position:0% +me call it over position X Prime this +you will write as an integral over some + + align:start position:0% +you will write as an integral over some + + + align:start position:0% +you will write as an integral over some +position + + align:start position:0% + + + + align:start position:0% + +X and then we're going to try to rewrite + + align:start position:0% +X and then we're going to try to rewrite + + + align:start position:0% +X and then we're going to try to rewrite +the whole thing in terms of + + align:start position:0% +the whole thing in terms of + + + align:start position:0% +the whole thing in terms of +um coordinates coordinate space so what + + align:start position:0% +um coordinates coordinate space so what + + + align:start position:0% +um coordinates coordinate space so what +do we have here we have integral P + + align:start position:0% + + + + align:start position:0% + +DP and the first five star would be the + + align:start position:0% +DP and the first five star would be the + + + align:start position:0% +DP and the first five star would be the +integral over DX Prime we said there's + + align:start position:0% +integral over DX Prime we said there's + + + align:start position:0% +integral over DX Prime we said there's +the square root of 2 pi H bar that we + + align:start position:0% +the square root of 2 pi H bar that we + + + align:start position:0% +the square root of 2 pi H bar that we +can't + + align:start position:0% +can't + + + align:start position:0% +can't +forget five P um it would have an e to + + align:start position:0% +forget five P um it would have an e to + + + align:start position:0% +forget five P um it would have an e to +the i p b x Prime over H + + align:start position:0% +the i p b x Prime over H + + + align:start position:0% +the i p b x Prime over H +bar and uh aze star of X + + align:start position:0% +bar and uh aze star of X + + + align:start position:0% +bar and uh aze star of X +Prime so I did conjugate um this five + + align:start position:0% +Prime so I did conjugate um this five + + + align:start position:0% +Prime so I did conjugate um this five +star of P that I may have it here yes + + align:start position:0% +star of P that I may have it here yes + + + align:start position:0% +star of P that I may have it here yes +it's + + align:start position:0% +it's + + + align:start position:0% +it's +here I conjugated it and uh did the + + align:start position:0% +here I conjugated it and uh did the + + + align:start position:0% +here I conjugated it and uh did the +integral over X + + align:start position:0% +integral over X + + + align:start position:0% +integral over X +Prime and now we have another one + + align:start position:0% +Prime and now we have another one + + + align:start position:0% +Prime and now we have another one +integral DX over 2 pi H + + align:start position:0% +integral DX over 2 pi H + + + align:start position:0% +integral DX over 2 pi H +bar e to the- I PX over H bar and you + + align:start position:0% +bar e to the- I PX over H bar and you + + + align:start position:0% +bar e to the- I PX over H bar and you +have S of + + align:start position:0% + + + + align:start position:0% + +X okay now there's a lot of integrals + + align:start position:0% +X okay now there's a lot of integrals + + + align:start position:0% +X okay now there's a lot of integrals +there and + + align:start position:0% +there and + + + align:start position:0% +there and +uh let's try to get them simplified + + align:start position:0% + + + + align:start position:0% + +okay so um we're going to try to do + + align:start position:0% +okay so um we're going to try to do + + + align:start position:0% +okay so um we're going to try to do +first the P + + align:start position:0% +first the P + + + align:start position:0% +first the P +integral so let's try to clean up + + align:start position:0% +integral so let's try to clean up + + + align:start position:0% +integral so let's try to clean up +everything in such a way that we have + + align:start position:0% +everything in such a way that we have + + + align:start position:0% +everything in such a way that we have +only P done first + + align:start position:0% +only P done first + + + align:start position:0% +only P done first +so we'll have a one over 2 pi H bar from + + align:start position:0% +so we'll have a one over 2 pi H bar from + + + align:start position:0% +so we'll have a one over 2 pi H bar from +the two square roots and I'll have the + + align:start position:0% +the two square roots and I'll have the + + + align:start position:0% +the two square roots and I'll have the +two integrals DX Prime SI of X + + align:start position:0% +two integrals DX Prime SI of X + + + align:start position:0% +two integrals DX Prime SI of X +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +Star d x s of + + align:start position:0% +Star d x s of + + + align:start position:0% +Star d x s of +X okay + + align:start position:0% +X okay + + + align:start position:0% +X okay +so look uh again as we said these + + align:start position:0% +so look uh again as we said these + + + align:start position:0% +so look uh again as we said these +integrals we just wrote them out they + + align:start position:0% +integrals we just wrote them out they + + + align:start position:0% +integrals we just wrote them out they +cannot be done so our only hope is to + + align:start position:0% +cannot be done so our only hope is to + + + align:start position:0% +cannot be done so our only hope is to +simplify first the PDP + + align:start position:0% +simplify first the PDP + + + align:start position:0% +simplify first the PDP +integral so um here we would have + + align:start position:0% +integral so um here we would have + + + align:start position:0% +integral so um here we would have +integral of + + align:start position:0% +integral of + + + align:start position:0% +integral of +DP * P * e to the i p x Prime over + + align:start position:0% +DP * P * e to the i p x Prime over + + + align:start position:0% +DP * P * e to the i p x Prime over +H and E to the- i + + align:start position:0% +H and E to the- i + + + align:start position:0% +H and E to the- i +p x over h + + align:start position:0% + + + + align:start position:0% + +more + + align:start position:0% +more + + + align:start position:0% +more +okay now we need a little bit of + + align:start position:0% +okay now we need a little bit of + + + align:start position:0% +okay now we need a little bit of +probably you were doing this um would + + align:start position:0% +probably you were doing this um would + + + align:start position:0% +probably you were doing this um would +not be obvious what to do unless you + + align:start position:0% +not be obvious what to do unless you + + + align:start position:0% +not be obvious what to do unless you +have some intuition of what the momentum + + align:start position:0% +have some intuition of what the momentum + + + align:start position:0% +have some intuition of what the momentum +operator used to be um the momentum + + align:start position:0% +operator used to be um the momentum + + + align:start position:0% +operator used to be um the momentum +operator used to be + + align:start position:0% +operator used to be + + + align:start position:0% +operator used to be +um DDX basically now this integral would + + align:start position:0% +um DDX basically now this integral would + + + align:start position:0% +um DDX basically now this integral would +be a Delta function if the P was not + + align:start position:0% +be a Delta function if the P was not + + + align:start position:0% +be a Delta function if the P was not +here but here is the P so what I should + + align:start position:0% +here but here is the P so what I should + + + align:start position:0% +here but here is the P so what I should +try to do is get rid of that P in order + + align:start position:0% +try to do is get rid of that P in order + + + align:start position:0% +try to do is get rid of that P in order +to understand what we have + + align:start position:0% +to understand what we have + + + align:start position:0% +to understand what we have +so here we'll do integral + + align:start position:0% +so here we'll do integral + + + align:start position:0% +so here we'll do integral +DP and look I'll put here minus H bar r/ + + align:start position:0% +DP and look I'll put here minus H bar r/ + + + align:start position:0% +DP and look I'll put here minus H bar r/ +I + + align:start position:0% + + + + align:start position:0% + +DDX and leave everything here to the + + align:start position:0% +DDX and leave everything here to the + + + align:start position:0% +DDX and leave everything here to the +right e to the i p x Prime over h e to + + align:start position:0% +right e to the i p x Prime over h e to + + + align:start position:0% +right e to the i p x Prime over h e to +the minus i p x over + + align:start position:0% + + + + align:start position:0% + +H I claim this is the same because this + + align:start position:0% +H I claim this is the same because this + + + align:start position:0% +H I claim this is the same because this +operator H over I DDX well it doesn't + + align:start position:0% +operator H over I DDX well it doesn't + + + align:start position:0% +operator H over I DDX well it doesn't +act on X Prime but it acts here and when + + align:start position:0% +act on X Prime but it acts here and when + + + align:start position:0% +act on X Prime but it acts here and when +it does it will produce just the factor + + align:start position:0% +it does it will produce just the factor + + + align:start position:0% +it does it will produce just the factor +of P that you have because the minus I + + align:start position:0% +of P that you have because the minus I + + + align:start position:0% +of P that you have because the minus I +and the minus I will cancel the H bar + + align:start position:0% +and the minus I will cancel the H bar + + + align:start position:0% +and the minus I will cancel the H bar +will cancel and the DDX will just bring + + align:start position:0% +will cancel and the DDX will just bring + + + align:start position:0% +will cancel and the DDX will just bring +down a p so this is the way to have this + + align:start position:0% +down a p so this is the way to have this + + + align:start position:0% +down a p so this is the way to have this +work out quite + + align:start position:0% +work out quite + + + align:start position:0% +work out quite +nicely + + align:start position:0% +nicely + + + align:start position:0% +nicely +now all right now this + + align:start position:0% +now all right now this + + + align:start position:0% +now all right now this +thing is inside the integral but it + + align:start position:0% +thing is inside the integral but it + + + align:start position:0% +thing is inside the integral but it +could as well be outside the integral it + + align:start position:0% +could as well be outside the integral it + + + align:start position:0% +could as well be outside the integral it +has nothing to do with DP so I'll + + align:start position:0% +has nothing to do with DP so I'll + + + align:start position:0% +has nothing to do with DP so I'll +rewrite this + + align:start position:0% +rewrite this + + + align:start position:0% +rewrite this +again I'll write it as DX Prime SI of X + + align:start position:0% +again I'll write it as DX Prime SI of X + + + align:start position:0% +again I'll write it as DX Prime SI of X +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +Star integral DX s of + + align:start position:0% +Star integral DX s of + + + align:start position:0% +Star integral DX s of +X and I'll put this here minus h/ I DDX + + align:start position:0% + + + + align:start position:0% + +in front of the integral the 1 2 pi H + + align:start position:0% +in front of the integral the 1 2 pi H + + + align:start position:0% +in front of the integral the 1 2 pi H +bar here integral + + align:start position:0% +bar here integral + + + align:start position:0% +bar here integral +DP e to the i p x Prime - x over H + + align:start position:0% +DP e to the i p x Prime - x over H + + + align:start position:0% +DP e to the i p x Prime - x over H +bar okay so I simply did a couple of + + align:start position:0% +bar okay so I simply did a couple of + + + align:start position:0% +bar okay so I simply did a couple of +things I moved it one over 2 pi H to the + + align:start position:0% +things I moved it one over 2 pi H to the + + + align:start position:0% +things I moved it one over 2 pi H to the +right and then I set this this + + align:start position:0% +right and then I set this this + + + align:start position:0% +right and then I set this this +derivative could be outside the integral + + align:start position:0% +derivative could be outside the integral + + + align:start position:0% +derivative could be outside the integral +because it's an integral over P doesn't + + align:start position:0% +because it's an integral over P doesn't + + + align:start position:0% +because it's an integral over P doesn't +interfere with X derivative so I took it + + align:start position:0% + + + + align:start position:0% + +out okay now the final two steps we're + + align:start position:0% +out okay now the final two steps we're + + + align:start position:0% +out okay now the final two steps we're +almost + + align:start position:0% + + + + align:start position:0% + +there the first step is to say with this + + align:start position:0% +there the first step is to say with this + + + align:start position:0% +there the first step is to say with this +is a DDX and yes this is a function of X + + align:start position:0% +is a DDX and yes this is a function of X + + + align:start position:0% +is a DDX and yes this is a function of X +and X Prime but I don't want to take + + align:start position:0% +and X Prime but I don't want to take + + + align:start position:0% +and X Prime but I don't want to take +that der ative because I'm going to + + align:start position:0% +that der ative because I'm going to + + + align:start position:0% +that der ative because I'm going to +complicate things in fact this is + + align:start position:0% +complicate things in fact this is + + + align:start position:0% +complicate things in fact this is +already looking like a Delta function + + align:start position:0% +already looking like a Delta function + + + align:start position:0% +already looking like a Delta function +there's a DP DP and the H bars that + + align:start position:0% +there's a DP DP and the H bars that + + + align:start position:0% +there's a DP DP and the H bars that +actually would cancel so this is a + + align:start position:0% +actually would cancel so this is a + + + align:start position:0% +actually would cancel so this is a +perfectly nice Delta function you can + + align:start position:0% +perfectly nice Delta function you can + + + align:start position:0% +perfectly nice Delta function you can +change variables do p equal U * H bar + + align:start position:0% +change variables do p equal U * H bar + + + align:start position:0% +change variables do p equal U * H bar +and see that actually the H bar doesn't + + align:start position:0% +and see that actually the H bar doesn't + + + align:start position:0% +and see that actually the H bar doesn't +matter and this is just Delta of x Prime + + align:start position:0% +matter and this is just Delta of x Prime + + + align:start position:0% +matter and this is just Delta of x Prime +- + + align:start position:0% + + + + align:start position:0% + +x and in here you will do you could act + + align:start position:0% +x and in here you will do you could act + + + align:start position:0% +x and in here you will do you could act +on the Delta function but you could say + + align:start position:0% +on the Delta function but you could say + + + align:start position:0% +on the Delta function but you could say +no let me do integration by parts and + + align:start position:0% +no let me do integration by parts and + + + align:start position:0% +no let me do integration by parts and +act on this + + align:start position:0% +act on this + + + align:start position:0% +act on this +one integration by + + align:start position:0% + + + + align:start position:0% + +parts when you do integration by parts + + align:start position:0% +parts when you do integration by parts + + + align:start position:0% +parts when you do integration by parts +you have to worry about the term at the + + align:start position:0% +you have to worry about the term at the + + + align:start position:0% +you have to worry about the term at the +boundary but if you're way functions + + align:start position:0% +boundary but if you're way functions + + + align:start position:0% +boundary but if you're way functions +vanish sufficiently fast at Infinity + + align:start position:0% +vanish sufficiently fast at Infinity + + + align:start position:0% +vanish sufficiently fast at Infinity +there's no problem so let's assume we're + + align:start position:0% +there's no problem so let's assume we're + + + align:start position:0% +there's no problem so let's assume we're +in that case we will integrate by parts + + align:start position:0% +in that case we will integrate by parts + + + align:start position:0% +in that case we will integrate by parts +and then do the Delta function so what + + align:start position:0% +and then do the Delta function so what + + + align:start position:0% +and then do the Delta function so what +do we have + + align:start position:0% + + + + align:start position:0% + +here I have integral DX + + align:start position:0% +here I have integral DX + + + align:start position:0% +here I have integral DX +Prime s star of X + + align:start position:0% +Prime s star of X + + + align:start position:0% +Prime s star of X +Prime integral DX and now I have because + + align:start position:0% +Prime integral DX and now I have because + + + align:start position:0% +Prime integral DX and now I have because +of the sign of integration by Parts h/ I + + align:start position:0% +of the sign of integration by Parts h/ I + + + align:start position:0% +of the sign of integration by Parts h/ I +DDX of + + align:start position:0% +DDX of + + + align:start position:0% +DDX of +p and then we have the Delta function of + + align:start position:0% +p and then we have the Delta function of + + + align:start position:0% +p and then we have the Delta function of +x - x + + align:start position:0% + + + + align:start position:0% + +Prime it's probably better still to + + align:start position:0% +Prime it's probably better still to + + + align:start position:0% +Prime it's probably better still to +write the integral like this DX H bar + + align:start position:0% +write the integral like this DX H bar + + + align:start position:0% +write the integral like this DX H bar +over i d DX of + + align:start position:0% +over i d DX of + + + align:start position:0% +over i d DX of +s time integral DX Prime P + + align:start position:0% +s time integral DX Prime P + + + align:start position:0% +s time integral DX Prime P +star of X Prime Delta of x - x + + align:start position:0% + + + + align:start position:0% + +Prime and we're almost + + align:start position:0% +Prime and we're almost + + + align:start position:0% +Prime and we're almost +done so that's + + align:start position:0% +done so that's + + + align:start position:0% +done so that's +good + + align:start position:0% +good + + + align:start position:0% +good +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um we're almost done we can do the + + align:start position:0% +um we're almost done we can do the + + + align:start position:0% +um we're almost done we can do the +integral over X Prime and it will + + align:start position:0% +integral over X Prime and it will + + + align:start position:0% +integral over X Prime and it will +evaluate that wave + + align:start position:0% +evaluate that wave + + + align:start position:0% +evaluate that wave +function at + + align:start position:0% + + + + align:start position:0% + +X so at the end of the day what have we + + align:start position:0% +X so at the end of the day what have we + + + align:start position:0% +X so at the end of the day what have we +found we found that P expectation value + + align:start position:0% +found we found that P expectation value + + + align:start position:0% +found we found that P expectation value +of P equal integral of P 5 of + + align:start position:0% +of P equal integral of P 5 of + + + align:start position:0% +of P equal integral of P 5 of +p^ squ + + align:start position:0% +p^ squ + + + align:start position:0% +p^ squ +DP is equal + + align:start position:0% +DP is equal + + + align:start position:0% +DP is equal +to we do this integral so we have + + align:start position:0% +to we do this integral so we have + + + align:start position:0% +to we do this integral so we have +integral + + align:start position:0% +integral + + + align:start position:0% +integral +DX I'll write it two times H over i d DX + + align:start position:0% +DX I'll write it two times H over i d DX + + + align:start position:0% +DX I'll write it two times H over i d DX +of x and t and Si + + align:start position:0% +of x and t and Si + + + align:start position:0% +of x and t and Si +star of x and + + align:start position:0% +star of x and + + + align:start position:0% +star of x and +t um I not sure I carried the times I + + align:start position:0% +t um I not sure I carried the times I + + + align:start position:0% +t um I not sure I carried the times I +didn't put the time anywhere so maybe I + + align:start position:0% +didn't put the time anywhere so maybe I + + + align:start position:0% +didn't put the time anywhere so maybe I +shouldn't put it + + align:start position:0% +shouldn't put it + + + align:start position:0% +shouldn't put it +here + + align:start position:0% +here + + + align:start position:0% +here +yet this is what we did it and might as + + align:start position:0% +yet this is what we did it and might as + + + align:start position:0% +yet this is what we did it and might as +well write it in the standard order + + align:start position:0% +well write it in the standard order + + + align:start position:0% +well write it in the standard order +where the complex conjugate function + + align:start position:0% +where the complex conjugate function + + + align:start position:0% +where the complex conjugate function +appears + + align:start position:0% + + + + align:start position:0% + +first okay this is what we + + align:start position:0% +first okay this is what we + + + align:start position:0% +first okay this is what we +found + + align:start position:0% +found + + + align:start position:0% +found +so this is actually very neat um let me + + align:start position:0% +so this is actually very neat um let me + + + align:start position:0% +so this is actually very neat um let me +put the time back everywhere you could + + align:start position:0% +put the time back everywhere you could + + + align:start position:0% +put the time back everywhere you could +put time because this is a Time + + align:start position:0% +put time because this is a Time + + + align:start position:0% +put time because this is a Time +dependent thing so P expectation value + + align:start position:0% +dependent thing so P expectation value + + + align:start position:0% +dependent thing so P expectation value +is + + align:start position:0% +is + + + align:start position:0% +is +p f of p and + + align:start position:0% +p f of p and + + + align:start position:0% +p f of p and +t squar d p is equal to integral + + align:start position:0% +t squar d p is equal to integral + + + align:start position:0% +t squar d p is equal to integral +DX s + + align:start position:0% +DX s + + + align:start position:0% +DX s +star of X and now we have if you wish P + + align:start position:0% +star of X and now we have if you wish P + + + align:start position:0% +star of X and now we have if you wish P +hat s of X where P hat + + align:start position:0% +hat s of X where P hat + + + align:start position:0% +hat s of X where P hat +is what we used to call the momentum + + align:start position:0% + + + + align:start position:0% + +operator so look what has happened uh we + + align:start position:0% +operator so look what has happened uh we + + + align:start position:0% +operator so look what has happened uh we +started with this + + align:start position:0% +started with this + + + align:start position:0% +started with this +expression for the expectation value of + + align:start position:0% +expression for the expectation value of + + + align:start position:0% +expression for the expectation value of +the momentum justified by the + + align:start position:0% +the momentum justified by the + + + align:start position:0% +the momentum justified by the +probabilistic interpretation of + + align:start position:0% +probabilistic interpretation of + + + align:start position:0% +probabilistic interpretation of +fi and we were led to this expression + + align:start position:0% +fi and we were led to this expression + + + align:start position:0% +fi and we were led to this expression +which is very similar to this one you + + align:start position:0% +which is very similar to this one you + + + align:start position:0% +which is very similar to this one you +see you have the star the and the X + + align:start position:0% +see you have the star the and the X + + + align:start position:0% +see you have the star the and the X +there but here the momentum appeared at + + align:start position:0% +there but here the momentum appeared at + + + align:start position:0% +there but here the momentum appeared at +this + + align:start position:0% +this + + + align:start position:0% +this +position acting on the wave function P + + align:start position:0% +position acting on the wave function P + + + align:start position:0% +position acting on the wave function P +not on P + + align:start position:0% +not on P + + + align:start position:0% +not on P +star and that's the way in quantum + + align:start position:0% +star and that's the way in quantum + + + align:start position:0% +star and that's the way in quantum +mechanics people Define expectation + + align:start position:0% +mechanics people Define expectation + + + align:start position:0% +mechanics people Define expectation +values of operators in general + + align:start position:0% +values of operators in general + + + align:start position:0% +values of operators in general +so in + + align:start position:0% + + + + align:start position:0% + +general + + align:start position:0% +general + + + align:start position:0% +general +around for an + + align:start position:0% + + + + align:start position:0% + +operator + + align:start position:0% +operator + + + align:start position:0% +operator +Q will Define the expectation value of + + align:start position:0% +Q will Define the expectation value of + + + align:start position:0% +Q will Define the expectation value of +Q to be + + align:start position:0% +Q to be + + + align:start position:0% +Q to be +integral + + align:start position:0% +integral + + + align:start position:0% +integral +DX P star + + align:start position:0% + + + + align:start position:0% + +of x and + + align:start position:0% +of x and + + + align:start position:0% +of x and +t q acting on S of x and + + align:start position:0% + + + + align:start position:0% + +t so you will + + align:start position:0% + + + + align:start position:0% + +always do this of putting the operator + + align:start position:0% +always do this of putting the operator + + + align:start position:0% +always do this of putting the operator +to act on the second part of the wave + + align:start position:0% +to act on the second part of the wave + + + align:start position:0% +to act on the second part of the wave +function on the second appearance of the + + align:start position:0% +function on the second appearance of the + + + align:start position:0% +function on the second appearance of the +wave function not on the P star + + align:start position:0% +wave function not on the P star + + + align:start position:0% +wave function not on the P star +but on the + + align:start position:0% + + + + align:start position:0% + +side um we can do other ex examples of + + align:start position:0% +side um we can do other ex examples of + + + align:start position:0% +side um we can do other ex examples of +this and uh our final + + align:start position:0% +this and uh our final + + + align:start position:0% +this and uh our final +theorem that um this is of course time + + align:start position:0% +theorem that um this is of course time + + + align:start position:0% +theorem that um this is of course time +dependent time + + align:start position:0% +dependent time + + + align:start position:0% +dependent time +dependent so let me do one example and + + align:start position:0% +dependent so let me do one example and + + + align:start position:0% +dependent so let me do one example and +uh our final um time dependence analysis + + align:start position:0% +uh our final um time dependence analysis + + + align:start position:0% +uh our final um time dependence analysis +of this quantity + + align:start position:0% + + + + align:start position:0% + +so 10 + + align:start position:0% + + + + align:start position:0% + +minutes so for example if you would + + align:start position:0% +minutes so for example if you would + + + align:start position:0% +minutes so for example if you would +think of the kinetic operator example + + align:start position:0% +think of the kinetic operator example + + + align:start position:0% +think of the kinetic operator example +kinetic operator + + align:start position:0% +kinetic operator + + + align:start position:0% +kinetic operator +T is p^ 2/ 2 + + align:start position:0% +T is p^ 2/ 2 + + + align:start position:0% +T is p^ 2/ 2 +m is a kinetic + + align:start position:0% + + + + align:start position:0% + +operator how would you compute its + + align:start position:0% +operator how would you compute its + + + align:start position:0% +operator how would you compute its +expectation + + align:start position:0% + + + + align:start position:0% + +value expectation value of the kinetic + + align:start position:0% +value expectation value of the kinetic + + + align:start position:0% +value expectation value of the kinetic +operator is + + align:start position:0% +operator is + + + align:start position:0% +operator is +what well I could do the position + + align:start position:0% +what well I could do the position + + + align:start position:0% +what well I could do the position +space + + align:start position:0% +space + + + align:start position:0% +space +calculation in which I'm think of the + + align:start position:0% +calculation in which I'm think of the + + + align:start position:0% +calculation in which I'm think of the +kinetic operator as an operator that + + align:start position:0% +kinetic operator as an operator that + + + align:start position:0% +kinetic operator as an operator that +acts in position space where the + + align:start position:0% +acts in position space where the + + + align:start position:0% +acts in position space where the +momentum is H bar over I DDX so then I + + align:start position:0% +momentum is H bar over I DDX so then I + + + align:start position:0% +momentum is H bar over I DDX so then I +would have integral + + align:start position:0% +would have integral + + + align:start position:0% +would have integral +DX SI star of x and t and then I would + + align:start position:0% +DX SI star of x and t and then I would + + + align:start position:0% +DX SI star of x and t and then I would +have Min - h^2 / 2 m DC D + + align:start position:0% +have Min - h^2 / 2 m DC D + + + align:start position:0% +have Min - h^2 / 2 m DC D +x² of s of X and + + align:start position:0% + + + + align:start position:0% + +D so here I did exactly what I was + + align:start position:0% +D so here I did exactly what I was + + + align:start position:0% +D so here I did exactly what I was +supposed to do given this + + align:start position:0% +supposed to do given this + + + align:start position:0% +supposed to do given this +formula but you could do another thing + + align:start position:0% +formula but you could do another thing + + + align:start position:0% +formula but you could do another thing +if you wished uh you could say look I + + align:start position:0% +if you wished uh you could say look I + + + align:start position:0% +if you wished uh you could say look I +can work in momentum + + align:start position:0% +can work in momentum + + + align:start position:0% +can work in momentum +space this is a momentum uh + + align:start position:0% +space this is a momentum uh + + + align:start position:0% +space this is a momentum uh +operator P just like I defined the + + align:start position:0% +operator P just like I defined the + + + align:start position:0% +operator P just like I defined the +expectation value of p i could have the + + align:start position:0% +expectation value of p i could have the + + + align:start position:0% +expectation value of p i could have the +expectation value of p^ s so the other + + align:start position:0% +expectation value of p^ s so the other + + + align:start position:0% +expectation value of p^ s so the other +possibility is that you have + + align:start position:0% +possibility is that you have + + + align:start position:0% +possibility is that you have +t is equal to the + + align:start position:0% +t is equal to the + + + align:start position:0% +t is equal to the +integral + + align:start position:0% +integral + + + align:start position:0% +integral +DP of p^ 2 / 2 m * 5 + + align:start position:0% +DP of p^ 2 / 2 m * 5 + + + align:start position:0% +DP of p^ 2 / 2 m * 5 +of P + + align:start position:0% + + + + align:start position:0% + +squar this is the operator and this is + + align:start position:0% +squar this is the operator and this is + + + align:start position:0% +squar this is the operator and this is +the probability or you could write it + + align:start position:0% +the probability or you could write it + + + align:start position:0% +the probability or you could write it +more elegantly perhaps + + align:start position:0% +more elegantly perhaps + + + align:start position:0% +more elegantly perhaps +DP 5 star of + + align:start position:0% +DP 5 star of + + + align:start position:0% +DP 5 star of +p p^ 2 / 2 m f of + + align:start position:0% + + + + align:start position:0% + +P this are just integrals of numbers all + + align:start position:0% +P this are just integrals of numbers all + + + align:start position:0% +P this are just integrals of numbers all +these are numbers + + align:start position:0% +these are numbers + + + align:start position:0% +these are numbers +already so in momentum space it's easier + + align:start position:0% +already so in momentum space it's easier + + + align:start position:0% +already so in momentum space it's easier +to find the expectation value of the + + align:start position:0% +to find the expectation value of the + + + align:start position:0% +to find the expectation value of the +kinetic + + align:start position:0% +kinetic + + + align:start position:0% +kinetic +operator in coordinate space you have to + + align:start position:0% +operator in coordinate space you have to + + + align:start position:0% +operator in coordinate space you have to +do this um you might even say look + + align:start position:0% +do this um you might even say look + + + align:start position:0% +do this um you might even say look +um this thing looks + + align:start position:0% + + + + align:start position:0% + +positive because it's p squ and the + + align:start position:0% +positive because it's p squ and the + + + align:start position:0% +positive because it's p squ and the +numbers square and this inter here it + + align:start position:0% +numbers square and this inter here it + + + align:start position:0% +numbers square and this inter here it +looks negative but uh that's an + + align:start position:0% +looks negative but uh that's an + + + align:start position:0% +looks negative but uh that's an +illusion this second derivative can be + + align:start position:0% +illusion this second derivative can be + + + align:start position:0% +illusion this second derivative can be +partially integrated one of the two + + align:start position:0% +partially integrated one of the two + + + align:start position:0% +partially integrated one of the two +derivatives can be integrated to act on + + align:start position:0% +derivatives can be integrated to act on + + + align:start position:0% +derivatives can be integrated to act on +this + + align:start position:0% +this + + + align:start position:0% +this +one so if you do an partial integration + + align:start position:0% +one so if you do an partial integration + + + align:start position:0% +one so if you do an partial integration +by parts you would have integral + + align:start position:0% +by parts you would have integral + + + align:start position:0% +by parts you would have integral +DX h^2 / 2 m and then you would have d + + align:start position:0% +DX h^2 / 2 m and then you would have d + + + align:start position:0% +DX h^2 / 2 m and then you would have d +s + + align:start position:0% +s + + + align:start position:0% +s +DX + + align:start position:0% +DX + + + align:start position:0% +DX +squared by integration by + + align:start position:0% +squared by integration by + + + align:start position:0% +squared by integration by +parts and that's clearly positive as + + align:start position:0% +parts and that's clearly positive as + + + align:start position:0% +parts and that's clearly positive as +well so it's similar to this \ No newline at end of file diff --git a/XW9xERSeenI.txt b/XW9xERSeenI.txt new file mode 100644 index 0000000000000000000000000000000000000000..ffc1646cda98ceb85c1265c1cf14354d25fae311 --- /dev/null +++ b/XW9xERSeenI.txt @@ -0,0 +1,12730 @@ +align:start position:0% + +all right welcome back to 61200 today we + + align:start position:0% +all right welcome back to 61200 today we + + + align:start position:0% +all right welcome back to 61200 today we +are talking about number Theory uh and + + align:start position:0% +are talking about number Theory uh and + + + align:start position:0% +are talking about number Theory uh and +number is I guess an old word here for + + align:start position:0% +number is I guess an old word here for + + + align:start position:0% +number is I guess an old word here for +integers in modern terminology um you + + align:start position:0% +integers in modern terminology um you + + + align:start position:0% +integers in modern terminology um you +know this Set uh Blackboard bold Z which + + align:start position:0% +know this Set uh Blackboard bold Z which + + + align:start position:0% +know this Set uh Blackboard bold Z which +is all positive and negative integers + + align:start position:0% +is all positive and negative integers + + + align:start position:0% +is all positive and negative integers +although mostly we think about natural + + align:start position:0% +although mostly we think about natural + + + align:start position:0% +although mostly we think about natural +numbers the non- negative integers uh + + align:start position:0% +numbers the non- negative integers uh + + + align:start position:0% +numbers the non- negative integers uh +number theory is a a big topic we're + + align:start position:0% +number theory is a a big topic we're + + + align:start position:0% +number theory is a a big topic we're +going to spend three lectures on it + + align:start position:0% +going to spend three lectures on it + + + align:start position:0% +going to spend three lectures on it +today and to next week um and it's a + + align:start position:0% +today and to next week um and it's a + + + align:start position:0% +today and to next week um and it's a +really important branch of sub Branch I + + align:start position:0% +really important branch of sub Branch I + + + align:start position:0% +really important branch of sub Branch I +guess or related branch of discrete + + align:start position:0% +guess or related branch of discrete + + + align:start position:0% +guess or related branch of discrete +mathematics uh in particular because + + align:start position:0% +mathematics uh in particular because + + + align:start position:0% +mathematics uh in particular because +it's found a lot of applications in + + align:start position:0% +it's found a lot of applications in + + + align:start position:0% +it's found a lot of applications in +modern days in cryptography and error + + align:start position:0% +modern days in cryptography and error + + + align:start position:0% +modern days in cryptography and error +correction every when you use your cell + + align:start position:0% +correction every when you use your cell + + + align:start position:0% +correction every when you use your cell +phone probably several different things + + align:start position:0% +phone probably several different things + + + align:start position:0% +phone probably several different things +uh in your in that software is using + + align:start position:0% +uh in your in that software is using + + + align:start position:0% +uh in your in that software is using +number Theory at some level to do crypto + + align:start position:0% +number Theory at some level to do crypto + + + align:start position:0% +number Theory at some level to do crypto +to access your bank to do uh error + + align:start position:0% +to access your bank to do uh error + + + align:start position:0% +to access your bank to do uh error +correction to talk over radio waves all + + align:start position:0% +correction to talk over radio waves all + + + align:start position:0% +correction to talk over radio waves all +sorts of fun things uh number three is + + align:start position:0% +sorts of fun things uh number three is + + + align:start position:0% +sorts of fun things uh number three is +also extremely old it's probably the + + align:start position:0% +also extremely old it's probably the + + + align:start position:0% +also extremely old it's probably the +oldest branch of mathematics though you + + align:start position:0% +oldest branch of mathematics though you + + + align:start position:0% +oldest branch of mathematics though you +know past 4,000 years it's a little hard + + align:start position:0% +know past 4,000 years it's a little hard + + + align:start position:0% +know past 4,000 years it's a little hard +to tell exactly what people were doing + + align:start position:0% +to tell exactly what people were doing + + + align:start position:0% +to tell exactly what people were doing +uh but in particular the Babylonians uh + + align:start position:0% +uh but in particular the Babylonians uh + + + align:start position:0% +uh but in particular the Babylonians uh +3,800 years ago were uh doing number + + align:start position:0% +3,800 years ago were uh doing number + + + align:start position:0% +3,800 years ago were uh doing number +Theory uh Pythagoras uh 25 200 years ago + + align:start position:0% +Theory uh Pythagoras uh 25 200 years ago + + + align:start position:0% +Theory uh Pythagoras uh 25 200 years ago +was doing number Theory um in the it had + + align:start position:0% +was doing number Theory um in the it had + + + align:start position:0% +was doing number Theory um in the it had +a a lot of exciting activity in the + + align:start position:0% +a a lot of exciting activity in the + + + align:start position:0% +a a lot of exciting activity in the +middle of last century uh Hardy is one + + align:start position:0% +middle of last century uh Hardy is one + + + align:start position:0% +middle of last century uh Hardy is one +of the famous uh number theories number + + align:start position:0% +of the famous uh number theories number + + + align:start position:0% +of the famous uh number theories number +theorists of sort of near our time um he + + align:start position:0% +theorists of sort of near our time um he + + + align:start position:0% +theorists of sort of near our time um he +wrote uh number theory is great because + + align:start position:0% +wrote uh number theory is great because + + + align:start position:0% +wrote uh number theory is great because +it's one science whose very remoteness + + align:start position:0% +it's one science whose very remoteness + + + align:start position:0% +it's one science whose very remoteness +very remoteness from human activities + + align:start position:0% +very remoteness from human activities + + + align:start position:0% +very remoteness from human activities +should keep it gentle and clean he was a + + align:start position:0% +should keep it gentle and clean he was a + + + align:start position:0% +should keep it gentle and clean he was a +pacifist and he wanted to do math that + + align:start position:0% +pacifist and he wanted to do math that + + + align:start position:0% +pacifist and he wanted to do math that +was completely useless from the + + align:start position:0% +was completely useless from the + + + align:start position:0% +was completely useless from the +perspective of warfare sadly uh that's + + align:start position:0% +perspective of warfare sadly uh that's + + + align:start position:0% +perspective of warfare sadly uh that's +not the case for number Theory anymore + + align:start position:0% +not the case for number Theory anymore + + + align:start position:0% +not the case for number Theory anymore +but it used to be um + + align:start position:0% +but it used to be um + + + align:start position:0% +but it used to be um +so uh but the things we'll be doing here + + align:start position:0% +so uh but the things we'll be doing here + + + align:start position:0% +so uh but the things we'll be doing here +are pretty fundamental uh today we're + + align:start position:0% +are pretty fundamental uh today we're + + + align:start position:0% +are pretty fundamental uh today we're +going to talk about divisibility and + + align:start position:0% +going to talk about divisibility and + + + align:start position:0% +going to talk about divisibility and +something called gcd which you may have + + align:start position:0% +something called gcd which you may have + + + align:start position:0% +something called gcd which you may have +heard of before it's a pretty basic + + align:start position:0% +heard of before it's a pretty basic + + + align:start position:0% +heard of before it's a pretty basic +notion both of these are but we're going + + align:start position:0% +notion both of these are but we're going + + + align:start position:0% +notion both of these are but we're going +to Define everything carefully and prove + + align:start position:0% +to Define everything carefully and prove + + + align:start position:0% +to Define everything carefully and prove +uh all sorts of cool properties about + + align:start position:0% +uh all sorts of cool properties about + + + align:start position:0% +uh all sorts of cool properties about +divisibility and use it to solve at + + align:start position:0% +divisibility and use it to solve at + + + align:start position:0% +divisibility and use it to solve at +least one fun + + align:start position:0% +least one fun + + + align:start position:0% +least one fun +problem so uh the notation for + + align:start position:0% +problem so uh the notation for + + + align:start position:0% +problem so uh the notation for +divisibility is a divides + + align:start position:0% +divisibility is a divides + + + align:start position:0% +divisibility is a divides +B uh we use a vertical bar we use a + + align:start position:0% +B uh we use a vertical bar we use a + + + align:start position:0% +B uh we use a vertical bar we use a +vertical Bar for a few other things like + + align:start position:0% +vertical Bar for a few other things like + + + align:start position:0% +vertical Bar for a few other things like +absolute value and set notation so try + + align:start position:0% +absolute value and set notation so try + + + align:start position:0% +absolute value and set notation so try +not to be too confused uh this will only + + align:start position:0% +not to be too confused uh this will only + + + align:start position:0% +not to be too confused uh this will only +be for uh a couple weeks um divisibility + + align:start position:0% +be for uh a couple weeks um divisibility + + + align:start position:0% +be for uh a couple weeks um divisibility +means uh a evenly divides b or B is + + align:start position:0% +means uh a evenly divides b or B is + + + align:start position:0% +means uh a evenly divides b or B is +evenly divisible by a okay so for + + align:start position:0% +evenly divisible by a okay so for + + + align:start position:0% +evenly divisible by a okay so for +example + + align:start position:0% +example + + + align:start position:0% +example +uh let's say uh two divides 4 as an + + align:start position:0% +uh let's say uh two divides 4 as an + + + align:start position:0% +uh let's say uh two divides 4 as an +example + + align:start position:0% + + + + align:start position:0% + +uh but in general what we would like is + + align:start position:0% +uh but in general what we would like is + + + align:start position:0% +uh but in general what we would like is +a a def a formal definition of + + align:start position:0% +a a def a formal definition of + + + align:start position:0% +a a def a formal definition of +this um so we'll say a divides B if + + align:start position:0% +this um so we'll say a divides B if + + + align:start position:0% +this um so we'll say a divides B if +there exists some integer + + align:start position:0% + + + + align:start position:0% + +multiple + + align:start position:0% +multiple + + + align:start position:0% +multiple +K such that uh B is that multiple of a + + align:start position:0% +K such that uh B is that multiple of a + + + align:start position:0% +K such that uh B is that multiple of a +so b equal K * a very important that + + align:start position:0% +so b equal K * a very important that + + + align:start position:0% +so b equal K * a very important that +this is an integer otherwise over reals + + align:start position:0% +this is an integer otherwise over reals + + + align:start position:0% +this is an integer otherwise over reals +this is always the case pretty + + align:start position:0% +this is always the case pretty + + + align:start position:0% +this is always the case pretty +much um and we Define divisibility in + + align:start position:0% +much um and we Define divisibility in + + + align:start position:0% +much um and we Define divisibility in +terms of multiplication instead of + + align:start position:0% +terms of multiplication instead of + + + align:start position:0% +terms of multiplication instead of +division I mean you could divide both + + align:start position:0% +division I mean you could divide both + + + align:start position:0% +division I mean you could divide both +sides by uh a here and so for example + + align:start position:0% +sides by uh a here and so for example + + + align:start position:0% +sides by uh a here and so for example +this is saying B divided by a is an + + align:start position:0% +this is saying B divided by a is an + + + align:start position:0% +this is saying B divided by a is an +integer but that's not such a great + + align:start position:0% +integer but that's not such a great + + + align:start position:0% +integer but that's not such a great +definition because it doesn't work well + + align:start position:0% +definition because it doesn't work well + + + align:start position:0% +definition because it doesn't work well +when you try to divide by zero this + + align:start position:0% +when you try to divide by zero this + + + align:start position:0% +when you try to divide by zero this +definition works even when B is when a + + align:start position:0% +definition works even when B is when a + + + align:start position:0% +definition works even when B is when a +is zero and uh otherwi if you do + + align:start position:0% +is zero and uh otherwi if you do + + + align:start position:0% +is zero and uh otherwi if you do +division it doesn't so that's why we + + align:start position:0% +division it doesn't so that's why we + + + align:start position:0% +division it doesn't so that's why we +Define divisibility this way so more + + align:start position:0% +Define divisibility this way so more + + + align:start position:0% +Define divisibility this way so more +interesting examples are 2 ID n uh means + + align:start position:0% +interesting examples are 2 ID n uh means + + + align:start position:0% +interesting examples are 2 ID n uh means +what we have been saying n is + + align:start position:0% +what we have been saying n is + + + align:start position:0% +what we have been saying n is +even whenever we say n is even what we + + align:start position:0% +even whenever we say n is even what we + + + align:start position:0% +even whenever we say n is even what we +really mean is two divides n there's + + align:start position:0% +really mean is two divides n there's + + + align:start position:0% +really mean is two divides n there's +some integer multiple of two that equals + + align:start position:0% +some integer multiple of two that equals + + + align:start position:0% +some integer multiple of two that equals +n okay uh some other weirder + + align:start position:0% +n okay uh some other weirder + + + align:start position:0% +n okay uh some other weirder +cases every natural + + align:start position:0% +cases every natural + + + align:start position:0% +cases every natural +number uh n divides n + + align:start position:0% +number uh n divides n + + + align:start position:0% +number uh n divides n +it's maybe not so intuitive what + + align:start position:0% +it's maybe not so intuitive what + + + align:start position:0% +it's maybe not so intuitive what +divisibility means for negative numbers + + align:start position:0% +divisibility means for negative numbers + + + align:start position:0% +divisibility means for negative numbers +but here are some examples we allow this + + align:start position:0% +but here are some examples we allow this + + + align:start position:0% +but here are some examples we allow this +integer multiple K to be negative so in + + align:start position:0% +integer multiple K to be negative so in + + + align:start position:0% +integer multiple K to be negative so in +particular K can be minus1 and minus1 * + + align:start position:0% +particular K can be minus1 and minus1 * + + + align:start position:0% +particular K can be minus1 and minus1 * +negative n is n okay also n divides n + + align:start position:0% +negative n is n okay also n divides n + + + align:start position:0% +negative n is n okay also n divides n +but that's a little less exciting uh + + align:start position:0% +but that's a little less exciting uh + + + align:start position:0% +but that's a little less exciting uh +another fun fact is that every number + + align:start position:0% +another fun fact is that every number + + + align:start position:0% +another fun fact is that every number +divides + + align:start position:0% +divides + + + align:start position:0% +divides +zero this is also maybe not the most + + align:start position:0% +zero this is also maybe not the most + + + align:start position:0% +zero this is also maybe not the most +intuitive but it comes from the + + align:start position:0% +intuitive but it comes from the + + + align:start position:0% +intuitive but it comes from the +definition K in particular can be zero + + align:start position:0% +definition K in particular can be zero + + + align:start position:0% +definition K in particular can be zero +and if you take 0 * n you get zero so + + align:start position:0% +and if you take 0 * n you get zero so + + + align:start position:0% +and if you take 0 * n you get zero so +everything divides zero uh number also + + align:start position:0% +everything divides zero uh number also + + + align:start position:0% +everything divides zero uh number also +divides its negative things like that um + + align:start position:0% +divides its negative things like that um + + + align:start position:0% +divides its negative things like that um +a consequence of these two things + + align:start position:0% +a consequence of these two things + + + align:start position:0% +a consequence of these two things +together is that zero is even if you + + align:start position:0% +together is that zero is even if you + + + align:start position:0% +together is that zero is even if you +were ever worried about whether zero was + + align:start position:0% +were ever worried about whether zero was + + + align:start position:0% +were ever worried about whether zero was +an exception to evenness in the + + align:start position:0% +an exception to evenness in the + + + align:start position:0% +an exception to evenness in the +alternation of of these numbers yes uh + + align:start position:0% +alternation of of these numbers yes uh + + + align:start position:0% +alternation of of these numbers yes uh +this is even this is even this is even + + align:start position:0% +this is even this is even this is even + + + align:start position:0% +this is even this is even this is even +because uh in particular 2 divides 0 + + align:start position:0% +because uh in particular 2 divides 0 + + + align:start position:0% +because uh in particular 2 divides 0 +everything divides Z but in particular + + align:start position:0% +everything divides Z but in particular + + + align:start position:0% +everything divides Z but in particular +two divid Z that's the meaning of + + align:start position:0% +two divid Z that's the meaning of + + + align:start position:0% +two divid Z that's the meaning of +even okay great uh + + align:start position:0% +even okay great uh + + + align:start position:0% +even okay great uh +let's State some theorems about + + align:start position:0% +let's State some theorems about + + + align:start position:0% +let's State some theorems about +divisibility I'm going to call these + + align:start position:0% +divisibility I'm going to call these + + + align:start position:0% +divisibility I'm going to call these +divisibility facts we're going to use + + align:start position:0% +divisibility facts we're going to use + + + align:start position:0% +divisibility facts we're going to use +them several times + + align:start position:0% +them several times + + + align:start position:0% +them several times +today uh let's say we have + + align:start position:0% +today uh let's say we have + + + align:start position:0% +today uh let's say we have +two numbers divisible by the same thing + + align:start position:0% + + + + align:start position:0% + +uh we call this uh D is a + + align:start position:0% +uh we call this uh D is a + + + align:start position:0% +uh we call this uh D is a +common + + align:start position:0% + + + + align:start position:0% + +divisor of A and B so D divides A and D + + align:start position:0% +divisor of A and B so D divides A and D + + + align:start position:0% +divisor of A and B so D divides A and D +divides B we call it a common + + align:start position:0% +divides B we call it a common + + + align:start position:0% +divides B we call it a common +divisor uh + + align:start position:0% +divisor uh + + + align:start position:0% +divisor uh +then I claim uh for example D divides a + + align:start position:0% +then I claim uh for example D divides a + + + align:start position:0% +then I claim uh for example D divides a +plus b their + + align:start position:0% +plus b their + + + align:start position:0% +plus b their +sum why this is very easy to prove if + + align:start position:0% +sum why this is very easy to prove if + + + align:start position:0% +sum why this is very easy to prove if +you just work through the definition so + + align:start position:0% +you just work through the definition so + + + align:start position:0% +you just work through the definition so +let's say um a = j * D and Bal K * D for + + align:start position:0% +let's say um a = j * D and Bal K * D for + + + align:start position:0% +let's say um a = j * D and Bal K * D for +some integers J and K they might be the + + align:start position:0% +some integers J and K they might be the + + + align:start position:0% +some integers J and K they might be the +same they might be different uh then a + + align:start position:0% +same they might be different uh then a + + + align:start position:0% +same they might be different uh then a +plus b well it's it's just the sum of + + align:start position:0% +plus b well it's it's just the sum of + + + align:start position:0% +plus b well it's it's just the sum of +these two things right it's j + K * + + align:start position:0% +these two things right it's j + K * + + + align:start position:0% +these two things right it's j + K * +D not very hard uh more generally uh D + + align:start position:0% +D not very hard uh more generally uh D + + + align:start position:0% +D not very hard uh more generally uh D +divides + + align:start position:0% +divides + + + align:start position:0% +divides +uh sa a + TB for any integers s and + + align:start position:0% + + + + align:start position:0% + +t uh this is just a a simple extension + + align:start position:0% +t uh this is just a a simple extension + + + align:start position:0% +t uh this is just a a simple extension +of this property um I guess you can + + align:start position:0% +of this property um I guess you can + + + align:start position:0% +of this property um I guess you can +write uh this thing equals uh SJ + TK * + + align:start position:0% +write uh this thing equals uh SJ + TK * + + + align:start position:0% +write uh this thing equals uh SJ + TK * +D um and it turns out this + + align:start position:0% +D um and it turns out this + + + align:start position:0% +D um and it turns out this +structure is interesting it's what we + + align:start position:0% +structure is interesting it's what we + + + align:start position:0% +structure is interesting it's what we +call an integer linear + + align:start position:0% +call an integer linear + + + align:start position:0% +call an integer linear +combination this is a concept we will + + align:start position:0% +combination this is a concept we will + + + align:start position:0% +combination this is a concept we will +also be using throughout + + align:start position:0% + + + + align:start position:0% + +today so much so that uh I'm going to + + align:start position:0% +today so much so that uh I'm going to + + + align:start position:0% +today so much so that uh I'm going to +give an acronym I don't usually like + + align:start position:0% +give an acronym I don't usually like + + + align:start position:0% +give an acronym I don't usually like +acronyms but this is so long that it's + + align:start position:0% +acronyms but this is so long that it's + + + align:start position:0% +acronyms but this is so long that it's +going to save me a ton of work to write + + align:start position:0% +going to save me a ton of work to write + + + align:start position:0% +going to save me a ton of work to write +ilc for integer linear combination uh if + + align:start position:0% +ilc for integer linear combination uh if + + + align:start position:0% +ilc for integer linear combination uh if +you know linear algebra this is just + + align:start position:0% +you know linear algebra this is just + + + align:start position:0% +you know linear algebra this is just +linear combination but where the + + align:start position:0% +linear combination but where the + + + align:start position:0% +linear combination but where the +coefficients need to be integers so it's + + align:start position:0% +coefficients need to be integers so it's + + + align:start position:0% +coefficients need to be integers so it's +exactly this notion so an integer linear + + align:start position:0% +exactly this notion so an integer linear + + + align:start position:0% +exactly this notion so an integer linear +combination of A and B uh is some number + + align:start position:0% +combination of A and B uh is some number + + + align:start position:0% +combination of A and B uh is some number +s * a plus T * B uh for + + align:start position:0% +s * a plus T * B uh for + + + align:start position:0% +s * a plus T * B uh for +any uh s and t that are integers okay so + + align:start position:0% +any uh s and t that are integers okay so + + + align:start position:0% +any uh s and t that are integers okay so +if I give you two numbers A and B we'll + + align:start position:0% +if I give you two numbers A and B we'll + + + align:start position:0% +if I give you two numbers A and B we'll +only be doing integer linear + + align:start position:0% +only be doing integer linear + + + align:start position:0% +only be doing integer linear +combinations today of two + + align:start position:0% +combinations today of two + + + align:start position:0% +combinations today of two +numbers uh then this is what they always + + align:start position:0% +numbers uh then this is what they always + + + align:start position:0% +numbers uh then this is what they always +look like and given two numbers there's + + align:start position:0% +look like and given two numbers there's + + + align:start position:0% +look like and given two numbers there's +some numbers you can construct VI + + align:start position:0% +some numbers you can construct VI + + + align:start position:0% +some numbers you can construct VI +integer linear combinations and some you + + align:start position:0% +integer linear combinations and some you + + + align:start position:0% +integer linear combinations and some you +can't uh actually fun fact divis + + align:start position:0% +can't uh actually fun fact divis + + + align:start position:0% +can't uh actually fun fact divis +is like integer linear combinations of + + align:start position:0% +is like integer linear combinations of + + + align:start position:0% +is like integer linear combinations of +one number this is saying B is an + + align:start position:0% +one number this is saying B is an + + + align:start position:0% +one number this is saying B is an +integer linear combination of just a uh + + align:start position:0% +integer linear combination of just a uh + + + align:start position:0% +integer linear combination of just a uh +but we that's so special we call it + + align:start position:0% +but we that's so special we call it + + + align:start position:0% +but we that's so special we call it +divisibility U two numbers is where + + align:start position:0% +divisibility U two numbers is where + + + align:start position:0% +divisibility U two numbers is where +integer linear combinations really get + + align:start position:0% +integer linear combinations really get + + + align:start position:0% +integer linear combinations really get +interesting all right so to motivate + + align:start position:0% +interesting all right so to motivate + + + align:start position:0% +interesting all right so to motivate +these Concepts more turns out these are + + align:start position:0% +these Concepts more turns out these are + + + align:start position:0% +these Concepts more turns out these are +key Concepts to solving a famous puzzle + + align:start position:0% +key Concepts to solving a famous puzzle + + + align:start position:0% +key Concepts to solving a famous puzzle +uh it's at least 80 90 years old called + + align:start position:0% +uh it's at least 80 90 years old called + + + align:start position:0% +uh it's at least 80 90 years old called +the water uh water pouring puzzle but it + + align:start position:0% +the water uh water pouring puzzle but it + + + align:start position:0% +the water uh water pouring puzzle but it +became particularly famous uh through + + align:start position:0% +became particularly famous uh through + + + align:start position:0% +became particularly famous uh through +Die Hard three Die Hard with a Vengeance + + align:start position:0% +Die Hard three Die Hard with a Vengeance + + + align:start position:0% +Die Hard three Die Hard with a Vengeance +so we're going to watch a little clip uh + + align:start position:0% +so we're going to watch a little clip uh + + + align:start position:0% +so we're going to watch a little clip uh +and if you uh if this clip is not + + align:start position:0% +and if you uh if this clip is not + + + align:start position:0% +and if you uh if this clip is not +included in this video you can go uh + + align:start position:0% +included in this video you can go uh + + + align:start position:0% +included in this video you can go uh +stream or uh purchase Die Hard with a + + align:start position:0% +stream or uh purchase Die Hard with a + + + align:start position:0% +stream or uh purchase Die Hard with a +Vengeance and start at the one hour mark + + align:start position:0% +Vengeance and start at the one hour mark + + + align:start position:0% +Vengeance and start at the one hour mark +and you will see an exchange like the + + align:start position:0% +and you will see an exchange like the + + + align:start position:0% +and you will see an exchange like the +following so we have uh of course John + + align:start position:0% +following so we have uh of course John + + + align:start position:0% +following so we have uh of course John +mlan here uh who's uh trying to save + + align:start position:0% +mlan here uh who's uh trying to save + + + align:start position:0% +mlan here uh who's uh trying to save +Manhattan uh along with his friend Zeus + + align:start position:0% +Manhattan uh along with his friend Zeus + + + align:start position:0% +Manhattan uh along with his friend Zeus +who's like an electrician who just + + align:start position:0% +who's like an electrician who just + + + align:start position:0% +who's like an electrician who just +happens to get uh brought into this + + align:start position:0% +happens to get uh brought into this + + + align:start position:0% +happens to get uh brought into this +whole chaos basically the bad guys are + + align:start position:0% +whole chaos basically the bad guys are + + + align:start position:0% +whole chaos basically the bad guys are +trying to distract the good guys by + + align:start position:0% +trying to distract the good guys by + + + align:start position:0% +trying to distract the good guys by +solving forcing them to solve puzzles so + + align:start position:0% +solving forcing them to solve puzzles so + + + align:start position:0% +solving forcing them to solve puzzles so +here we go all right so we're going to + + align:start position:0% +here we go all right so we're going to + + + align:start position:0% +here we go all right so we're going to +focus on the problem at hand uh which uh + + align:start position:0% +focus on the problem at hand uh which uh + + + align:start position:0% +focus on the problem at hand uh which uh +we can formalize as + + align:start position:0% + + + + align:start position:0% + +follows uh so we have two + + align:start position:0% +follows uh so we have two + + + align:start position:0% +follows uh so we have two +jugs uh we'll say of + + align:start position:0% + + + + align:start position:0% + +capacity A and B and we'll assume + + align:start position:0% +capacity A and B and we'll assume + + + align:start position:0% +capacity A and B and we'll assume +they're integers and in the + + align:start position:0% +they're integers and in the + + + align:start position:0% +they're integers and in the +example uh that saves Manhattan we have + + align:start position:0% +example uh that saves Manhattan we have + + + align:start position:0% +example uh that saves Manhattan we have +a equals 5 and b equals 3 and we'd like + + align:start position:0% +a equals 5 and b equals 3 and we'd like + + + align:start position:0% +a equals 5 and b equals 3 and we'd like +to represent some number uh in this case + + align:start position:0% +to represent some number uh in this case + + + align:start position:0% +to represent some number uh in this case +four by a sequence of pouring + + align:start position:0% +four by a sequence of pouring + + + align:start position:0% +four by a sequence of pouring +operations uh so um how could we + + align:start position:0% +operations uh so um how could we + + + align:start position:0% +operations uh so um how could we +represent this water porn in problem + + align:start position:0% +represent this water porn in problem + + + align:start position:0% +represent this water porn in problem +using techniques that we have from + + align:start position:0% +using techniques that we have from + + + align:start position:0% +using techniques that we have from +previous + + align:start position:0% +previous + + + align:start position:0% +previous +lectures any + + align:start position:0% + + + + align:start position:0% + +ideas I heard + + align:start position:0% +ideas I heard + + + align:start position:0% +ideas I heard +something yeah State machines good so + + align:start position:0% +something yeah State machines good so + + + align:start position:0% +something yeah State machines good so +we'll use a state machine um and so + + align:start position:0% +we'll use a state machine um and so + + + align:start position:0% +we'll use a state machine um and so +we'll have a + + align:start position:0% +we'll have a + + + align:start position:0% +we'll have a +state x and y means that there's + + align:start position:0% +state x and y means that there's + + + align:start position:0% +state x and y means that there's +currently X gallons in the first jug and + + align:start position:0% +currently X gallons in the first jug and + + + align:start position:0% +currently X gallons in the first jug and +Y gallons in the second jck + + align:start position:0% +Y gallons in the second jck + + + align:start position:0% +Y gallons in the second jck +uh or let's say the uh + + align:start position:0% + + + + align:start position:0% + +amounts in uh + + align:start position:0% +amounts in uh + + + align:start position:0% +amounts in uh +each + + align:start position:0% + + + + align:start position:0% + +joke okay so uh we + + align:start position:0% +joke okay so uh we + + + align:start position:0% +joke okay so uh we +start at the state z z let's say the + + align:start position:0% +start at the state z z let's say the + + + align:start position:0% +start at the state z z let's say the +drug started empty uh we're given an + + align:start position:0% +drug started empty uh we're given an + + + align:start position:0% +drug started empty uh we're given an +infinite water supply because they're at + + align:start position:0% +infinite water supply because they're at + + + align:start position:0% +infinite water supply because they're at +a fountain + + align:start position:0% +a fountain + + + align:start position:0% +a fountain +conveniently um + + align:start position:0% + + + + align:start position:0% + +and let's see we want to finish at a + + align:start position:0% +and let's see we want to finish at a + + + align:start position:0% +and let's see we want to finish at a +state that has four in one of the two + + align:start position:0% +state that has four in one of the two + + + align:start position:0% +state that has four in one of the two +values and as John mlan said uh it has + + align:start position:0% +values and as John mlan said uh it has + + + align:start position:0% +values and as John mlan said uh it has +to be in the bigger one in this case + + align:start position:0% +to be in the bigger one in this case + + + align:start position:0% +to be in the bigger one in this case +because four is bigger than + + align:start position:0% +because four is bigger than + + + align:start position:0% +because four is bigger than +three so we'd like + + align:start position:0% +three so we'd like + + + align:start position:0% +three so we'd like +to uh goal is to get to uh four comma + + align:start position:0% +to uh goal is to get to uh four comma + + + align:start position:0% +to uh goal is to get to uh four comma +something and the tricky part is to + + align:start position:0% +something and the tricky part is to + + + align:start position:0% +something and the tricky part is to +write down the transitions here so let's + + align:start position:0% +write down the transitions here so let's + + + align:start position:0% +write down the transitions here so let's +write down some of the + + align:start position:0% + + + + align:start position:0% + +transitions + + align:start position:0% + + + + align:start position:0% + +transitions so given X and + + align:start position:0% +transitions so given X and + + + align:start position:0% +transitions so given X and +Y uh what are the some of the things I + + align:start position:0% +Y uh what are the some of the things I + + + align:start position:0% +Y uh what are the some of the things I +could + + align:start position:0% +could + + + align:start position:0% +could +do any + + align:start position:0% +do any + + + align:start position:0% +do any +suggestions I have some partially filled + + align:start position:0% +suggestions I have some partially filled + + + align:start position:0% +suggestions I have some partially filled +jars these are two jars of uh five and + + align:start position:0% +jars these are two jars of uh five and + + + align:start position:0% +jars these are two jars of uh five and +three pumpkins capacity respectively uh + + align:start position:0% +three pumpkins capacity respectively uh + + + align:start position:0% +three pumpkins capacity respectively uh +maybe I'm at some position here what + + align:start position:0% +maybe I'm at some position here what + + + align:start position:0% +maybe I'm at some position here what +could I do to these trugs yeah the back + + align:start position:0% +could I do to these trugs yeah the back + + + align:start position:0% +could I do to these trugs yeah the back +fill one to the top I I go to the + + align:start position:0% +fill one to the top I I go to the + + + align:start position:0% +fill one to the top I I go to the +Fountain I pour it up until it's + + align:start position:0% +Fountain I pour it up until it's + + + align:start position:0% +Fountain I pour it up until it's +completely fill or or this one I could + + align:start position:0% +completely fill or or this one I could + + + align:start position:0% +completely fill or or this one I could +go to the fill Point other suggestions + + align:start position:0% +go to the fill Point other suggestions + + + align:start position:0% +go to the fill Point other suggestions +yeah empty I could empty one of the jars + + align:start position:0% +yeah empty I could empty one of the jars + + + align:start position:0% +yeah empty I could empty one of the jars +hopefully I won't need that so in the + + align:start position:0% +hopefully I won't need that so in the + + + align:start position:0% +hopefully I won't need that so in the +transitions this is this corresponds to + + align:start position:0% +transitions this is this corresponds to + + + align:start position:0% +transitions this is this corresponds to +going to uh I guess a comma y if I fill + + align:start position:0% +going to uh I guess a comma y if I fill + + + align:start position:0% +going to uh I guess a comma y if I fill +the first one um or I could go to x + + align:start position:0% +the first one um or I could go to x + + + align:start position:0% +the first one um or I could go to x +comma B if I fill the second one um I + + align:start position:0% +comma B if I fill the second one um I + + + align:start position:0% +comma B if I fill the second one um I +could empty by going to uh 0 comma y if + + align:start position:0% +could empty by going to uh 0 comma y if + + + align:start position:0% +could empty by going to uh 0 comma y if +I empty the first one or I could go to x + + align:start position:0% +I empty the first one or I could go to x + + + align:start position:0% +I empty the first one or I could go to x +comma 0 so these are all sorry this is + + align:start position:0% +comma 0 so these are all sorry this is + + + align:start position:0% +comma 0 so these are all sorry this is +all transitions from + + align:start position:0% +all transitions from + + + align:start position:0% +all transitions from +XY uh anything else + + align:start position:0% + + + + align:start position:0% + +yeah I can pour the contents of one jug + + align:start position:0% +yeah I can pour the contents of one jug + + + align:start position:0% +yeah I can pour the contents of one jug +into the other cool yeah so here for + + align:start position:0% +into the other cool yeah so here for + + + align:start position:0% +into the other cool yeah so here for +example I filled up a three I poured in + + align:start position:0% +example I filled up a three I poured in + + + align:start position:0% +example I filled up a three I poured in +three uh I could fill this one up again + + align:start position:0% +three uh I could fill this one up again + + + align:start position:0% +three uh I could fill this one up again +and pour it in again and at some point + + align:start position:0% +and pour it in again and at some point + + + align:start position:0% +and pour it in again and at some point +uh I'll run out of capacity in this jug + + align:start position:0% +uh I'll run out of capacity in this jug + + + align:start position:0% +uh I'll run out of capacity in this jug +and that's an event that I can detect + + align:start position:0% +and that's an event that I can detect + + + align:start position:0% +and that's an event that I can detect +when I reach level Che okay so to write + + align:start position:0% +when I reach level Che okay so to write + + + align:start position:0% +when I reach level Che okay so to write +that down more carefully given + + align:start position:0% +that down more carefully given + + + align:start position:0% +that down more carefully given +XY we can transition to one of two cases + + align:start position:0% +XY we can transition to one of two cases + + + align:start position:0% +XY we can transition to one of two cases +either we get to completely empty the + + align:start position:0% +either we get to completely empty the + + + align:start position:0% +either we get to completely empty the +left jug into the right jug so this + + align:start position:0% +left jug into the right jug so this + + + align:start position:0% +left jug into the right jug so this +would be uh x + y but that's only + + align:start position:0% +would be uh x + y but that's only + + + align:start position:0% +would be uh x + y but that's only +possible + + align:start position:0% +possible + + + align:start position:0% +possible +if it fits in the second jug If X Plus Y + + align:start position:0% +if it fits in the second jug If X Plus Y + + + align:start position:0% +if it fits in the second jug If X Plus Y +is less than or equal to B otherwise to + + align:start position:0% +is less than or equal to B otherwise to + + + align:start position:0% +is less than or equal to B otherwise to +do arithmetic this too hard uh we move + + align:start position:0% +do arithmetic this too hard uh we move + + + align:start position:0% +do arithmetic this too hard uh we move +over B minus y or something um so we + + align:start position:0% +over B minus y or something um so we + + + align:start position:0% +over B minus y or something um so we +have x minus B minus y comma B + + align:start position:0% +have x minus B minus y comma B + + + align:start position:0% +have x minus B minus y comma B +otherwise okay if we end up filling up + + align:start position:0% +otherwise okay if we end up filling up + + + align:start position:0% +otherwise okay if we end up filling up +the second one then this is how much uh + + align:start position:0% +the second one then this is how much uh + + + align:start position:0% +the second one then this is how much uh +of the original X that I started with + + align:start position:0% +of the original X that I started with + + + align:start position:0% +of the original X that I started with +remains + + align:start position:0% +remains + + + align:start position:0% +remains +okay uh and you can do the there's one + + align:start position:0% +okay uh and you can do the there's one + + + align:start position:0% +okay uh and you can do the there's one +more rule which is if I pour from right + + align:start position:0% +more rule which is if I pour from right + + + align:start position:0% +more rule which is if I pour from right +to left those are the available uh State + + align:start position:0% +to left those are the available uh State + + + align:start position:0% +to left those are the available uh State +transitions in this puzzle uh and now + + align:start position:0% +transitions in this puzzle uh and now + + + align:start position:0% +transitions in this puzzle uh and now +maybe I've talked about it long enough + + align:start position:0% +maybe I've talked about it long enough + + + align:start position:0% +maybe I've talked about it long enough +you have some intuition on how to solve + + align:start position:0% +you have some intuition on how to solve + + + align:start position:0% +you have some intuition on how to solve +this start + + align:start position:0% +this start + + + align:start position:0% +this start +empty any suggestions on how to + + align:start position:0% +empty any suggestions on how to + + + align:start position:0% +empty any suggestions on how to +construct the number + + align:start position:0% + + + + align:start position:0% + +four yeah + + align:start position:0% + + + + align:start position:0% + +let fill up the five gallon + + align:start position:0% +let fill up the five gallon + + + align:start position:0% +let fill up the five gallon +jug + + align:start position:0% + + + + align:start position:0% + +okay okay we're going to transfer the + + align:start position:0% +okay okay we're going to transfer the + + + align:start position:0% +okay okay we're going to transfer the +three gallon jug until the three gallon + + align:start position:0% +three gallon jug until the three gallon + + + align:start position:0% +three gallon jug until the three gallon +jug is exactly empty which if you're + + align:start position:0% +jug is exactly empty which if you're + + + align:start position:0% +jug is exactly empty which if you're +using water it would be + + align:start position:0% +using water it would be + + + align:start position:0% +using water it would be +level okay empty the three gallon + + align:start position:0% + + + + align:start position:0% + +jug okay move the two over this now + + align:start position:0% +jug okay move the two over this now + + + align:start position:0% +jug okay move the two over this now +feels like towers of anoi + + align:start position:0% +feels like towers of anoi + + + align:start position:0% +feels like towers of anoi +okay fill the five + + align:start position:0% +okay fill the five + + + align:start position:0% +okay fill the five +and then transfer like + + align:start position:0% +and then transfer like + + + align:start position:0% +and then transfer like +this from five to did I get the right + + align:start position:0% +this from five to did I get the right + + + align:start position:0% +this from five to did I get the right +number there we go water's water's + + align:start position:0% +number there we go water's water's + + + align:start position:0% +number there we go water's water's +particularly unsettled today all right + + align:start position:0% +particularly unsettled today all right + + + align:start position:0% +particularly unsettled today all right +so we've got uh five on the right if I + + align:start position:0% +so we've got uh five on the right if I + + + align:start position:0% +so we've got uh five on the right if I +can count and we fill over here until + + align:start position:0% +can count and we fill over here until + + + align:start position:0% +can count and we fill over here until +this one is filled and now we've got the + + align:start position:0% +this one is filled and now we've got the + + + align:start position:0% +this one is filled and now we've got the +number four + + align:start position:0% +number four + + + align:start position:0% +number four +yay uh that's how we solve that's how we + + align:start position:0% +yay uh that's how we solve that's how we + + + align:start position:0% +yay uh that's how we solve that's how we +save Manhattan with uh with this water + + align:start position:0% +save Manhattan with uh with this water + + + align:start position:0% +save Manhattan with uh with this water +pouring problem but uh while the bad + + align:start position:0% +pouring problem but uh while the bad + + + align:start position:0% +pouring problem but uh while the bad +guys are off uh stealing + + align:start position:0% +guys are off uh stealing + + + align:start position:0% +guys are off uh stealing +money from the bank um but sometimes + + align:start position:0% +money from the bank um but sometimes + + + align:start position:0% +money from the bank um but sometimes +this puzzle isn't solvable so let's take + + align:start position:0% +this puzzle isn't solvable so let's take + + + align:start position:0% +this puzzle isn't solvable so let's take +another + + align:start position:0% +another + + + align:start position:0% +another +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +example uh let's say we want uh AAL 6 + + align:start position:0% +example uh let's say we want uh AAL 6 + + + align:start position:0% +example uh let's say we want uh AAL 6 +bals 4 and we want the number + + align:start position:0% +bals 4 and we want the number + + + align:start position:0% +bals 4 and we want the number +three is this possible I already gave + + align:start position:0% +three is this possible I already gave + + + align:start position:0% +three is this possible I already gave +away that this is impossible why is it + + align:start position:0% +away that this is impossible why is it + + + align:start position:0% +away that this is impossible why is it +impossible any + + align:start position:0% +impossible any + + + align:start position:0% +impossible any +feelings hint it has something to do + + align:start position:0% +feelings hint it has something to do + + + align:start position:0% +feelings hint it has something to do +with this + + align:start position:0% +with this + + + align:start position:0% +with this +stuff + + align:start position:0% + + + + align:start position:0% + +yeah okay you said there are no integer + + align:start position:0% +yeah okay you said there are no integer + + + align:start position:0% +yeah okay you said there are no integer +linear combinations where of six and + + align:start position:0% +linear combinations where of six and + + + align:start position:0% +linear combinations where of six and +four that make three that is true but uh + + align:start position:0% +four that make three that is true but uh + + + align:start position:0% +four that make three that is true but uh +this problem isn't directly about + + align:start position:0% +this problem isn't directly about + + + align:start position:0% +this problem isn't directly about +integer linear combinations is it I + + align:start position:0% +integer linear combinations is it I + + + align:start position:0% +integer linear combinations is it I +don't + + align:start position:0% + + + + align:start position:0% + +know + + align:start position:0% + + + + align:start position:0% + +yeah there's no way to get an odd number + + align:start position:0% +yeah there's no way to get an odd number + + + align:start position:0% +yeah there's no way to get an odd number +from these two + + align:start position:0% +from these two + + + align:start position:0% +from these two +gallons that's the simp both of you are + + align:start position:0% +gallons that's the simp both of you are + + + align:start position:0% +gallons that's the simp both of you are +correct uh the simpler reason in this + + align:start position:0% +correct uh the simpler reason in this + + + align:start position:0% +correct uh the simpler reason in this +case + + align:start position:0% +case + + + align:start position:0% +case +uh is it's impossible to get an odd + + align:start position:0% + + + + align:start position:0% + +amount um I guess the proof of both of + + align:start position:0% +amount um I guess the proof of both of + + + align:start position:0% +amount um I guess the proof of both of +these things is you look at all the + + align:start position:0% +these things is you look at all the + + + align:start position:0% +these things is you look at all the +possible Transitions and uh You observe + + align:start position:0% +possible Transitions and uh You observe + + + align:start position:0% +possible Transitions and uh You observe +that if you start with A and B being + + align:start position:0% +that if you start with A and B being + + + align:start position:0% +that if you start with A and B being +even you can never construct an odd + + align:start position:0% +even you can never construct an odd + + + align:start position:0% +even you can never construct an odd +number by adding and subtracting all + + align:start position:0% +number by adding and subtracting all + + + align:start position:0% +number by adding and subtracting all +we're doing here taking numbers that + + align:start position:0% +we're doing here taking numbers that + + + align:start position:0% +we're doing here taking numbers that +we've constructed adding them and or + + align:start position:0% +we've constructed adding them and or + + + align:start position:0% +we've constructed adding them and or +subtracting them with a and b or each + + align:start position:0% +subtracting them with a and b or each + + + align:start position:0% +subtracting them with a and b or each +other and so if you start with even + + align:start position:0% +other and so if you start with even + + + align:start position:0% +other and so if you start with even +numbers you add and subtract them you + + align:start position:0% +numbers you add and subtract them you + + + align:start position:0% +numbers you add and subtract them you +always stay within the even numbers but + + align:start position:0% +always stay within the even numbers but + + + align:start position:0% +always stay within the even numbers but +also as you're saying if you start with + + align:start position:0% +also as you're saying if you start with + + + align:start position:0% +also as you're saying if you start with +an integer linear combination of A and B + + align:start position:0% +an integer linear combination of A and B + + + align:start position:0% +an integer linear combination of A and B +all you can get are integer linear + + align:start position:0% +all you can get are integer linear + + + align:start position:0% +all you can get are integer linear +combinations of A and B so here is uh a + + align:start position:0% +combinations of A and B so here is uh a + + + align:start position:0% +combinations of A and B so here is uh a +key Lemma about this puzzle and why that + + align:start position:0% +key Lemma about this puzzle and why that + + + align:start position:0% +key Lemma about this puzzle and why that +is impossible more + + align:start position:0% +is impossible more + + + align:start position:0% +is impossible more +generally is uh all reachable + + align:start position:0% + + + + align:start position:0% + +amounts in this puzzle are integer + + align:start position:0% +amounts in this puzzle are integer + + + align:start position:0% +amounts in this puzzle are integer +linear + + align:start position:0% +linear + + + align:start position:0% +linear +combinations of A and + + align:start position:0% +combinations of A and + + + align:start position:0% +combinations of A and +B let's prove + + align:start position:0% + + + + align:start position:0% + +this any suggestions on how to prove a + + align:start position:0% +this any suggestions on how to prove a + + + align:start position:0% +this any suggestions on how to prove a +property like + + align:start position:0% + + + + align:start position:0% + +this you remember all the way back to + + align:start position:0% +this you remember all the way back to + + + align:start position:0% +this you remember all the way back to +State machines hopefully you've been + + align:start position:0% +State machines hopefully you've been + + + align:start position:0% +State machines hopefully you've been +studying for the test State machines are + + align:start position:0% +studying for the test State machines are + + + align:start position:0% +studying for the test State machines are +on the test this lecture is not it will + + align:start position:0% +on the test this lecture is not it will + + + align:start position:0% +on the test this lecture is not it will +be on quiz + + align:start position:0% + + + + align:start position:0% + +two invariance yeah in particular + + align:start position:0% +two invariance yeah in particular + + + align:start position:0% +two invariance yeah in particular +uh this this is a statement about + + align:start position:0% +uh this this is a statement about + + + align:start position:0% +uh this this is a statement about +invariance this is saying uh for all + + align:start position:0% +invariance this is saying uh for all + + + align:start position:0% +invariance this is saying uh for all +reachable uh X comma + + align:start position:0% + + + + align:start position:0% + +y um X and Y are integer linear + + align:start position:0% +y um X and Y are integer linear + + + align:start position:0% +y um X and Y are integer linear +combinations of A and B so this is an + + align:start position:0% +combinations of A and B so this is an + + + align:start position:0% +combinations of A and B so this is an +invariant property this is a state + + align:start position:0% +invariant property this is a state + + + align:start position:0% +invariant property this is a state +predicate we want to prove that it's + + align:start position:0% +predicate we want to prove that it's + + + align:start position:0% +predicate we want to prove that it's +invariant that is true for all reachable + + align:start position:0% +invariant that is true for all reachable + + + align:start position:0% +invariant that is true for all reachable +states starting from 0 0 um and we + + align:start position:0% +states starting from 0 0 um and we + + + align:start position:0% +states starting from 0 0 um and we +usually do that using the invariant + + align:start position:0% + + + + align:start position:0% + +principle which has requires two steps + + align:start position:0% +principle which has requires two steps + + + align:start position:0% +principle which has requires two steps +one is base case we need to check that + + align:start position:0% +one is base case we need to check that + + + align:start position:0% +one is base case we need to check that +this predicate holds + + align:start position:0% +this predicate holds + + + align:start position:0% +this predicate holds +initially uh and the initial state for + + align:start position:0% +initially uh and the initial state for + + + align:start position:0% +initially uh and the initial state for +us is 0 comma 0 and we observe that zero + + align:start position:0% +us is 0 comma 0 and we observe that zero + + + align:start position:0% +us is 0 comma 0 and we observe that zero +is indeed a linear combination of A and + + align:start position:0% +is indeed a linear combination of A and + + + align:start position:0% +is indeed a linear combination of A and +B namely 0 * a uh plus 0 * B great base + + align:start position:0% +B namely 0 * a uh plus 0 * B great base + + + align:start position:0% +B namely 0 * a uh plus 0 * B great base +case is true and so now we just need the + + align:start position:0% +case is true and so now we just need the + + + align:start position:0% +case is true and so now we just need the +inductive step or the I guess the + + align:start position:0% +inductive step or the I guess the + + + align:start position:0% +inductive step or the I guess the +preserved the fact that this predicate + + align:start position:0% +preserved the fact that this predicate + + + align:start position:0% +preserved the fact that this predicate +is + + align:start position:0% + + + + align:start position:0% + +preserved uh so suppose that we're at + + align:start position:0% +preserved uh so suppose that we're at + + + align:start position:0% +preserved uh so suppose that we're at +some State X and Y where the predicate + + align:start position:0% +some State X and Y where the predicate + + + align:start position:0% +some State X and Y where the predicate +is true uh so xal sa a + TB and y = s + + align:start position:0% +is true uh so xal sa a + TB and y = s + + + align:start position:0% +is true uh so xal sa a + TB and y = s +prime a + T Prime B + + align:start position:0% +prime a + T Prime B + + + align:start position:0% +prime a + T Prime B +um and then we just look at all of the + + align:start position:0% +um and then we just look at all of the + + + align:start position:0% +um and then we just look at all of the +available + + align:start position:0% +available + + + align:start position:0% +available +Transitions and we show that every + + align:start position:0% +Transitions and we show that every + + + align:start position:0% +Transitions and we show that every +number that you can make uh is indeed an + + align:start position:0% +number that you can make uh is indeed an + + + align:start position:0% +number that you can make uh is indeed an +integer linear combination of uh A and B + + align:start position:0% +integer linear combination of uh A and B + + + align:start position:0% +integer linear combination of uh A and B +so let's do one example we can construct + + align:start position:0% +so let's do one example we can construct + + + align:start position:0% +so let's do one example we can construct +X + Y X + Y uh we can rewrite as um s + + + align:start position:0% +X + Y X + Y uh we can rewrite as um s + + + + align:start position:0% +X + Y X + Y uh we can rewrite as um s + +S Prime * a and t + T Prime * B so + + align:start position:0% +S Prime * a and t + T Prime * B so + + + align:start position:0% +S Prime * a and t + T Prime * B so +that's uh if this transition happens to + + align:start position:0% +that's uh if this transition happens to + + + align:start position:0% +that's uh if this transition happens to +be possible it may not be possible + + align:start position:0% +be possible it may not be possible + + + align:start position:0% +be possible it may not be possible +because there's this if condition but if + + align:start position:0% +because there's this if condition but if + + + align:start position:0% +because there's this if condition but if +we show that every thing every number we + + align:start position:0% +we show that every thing every number we + + + align:start position:0% +we show that every thing every number we +could possibly build has this property + + align:start position:0% +could possibly build has this property + + + align:start position:0% +could possibly build has this property +then of course all the ones that we can + + align:start position:0% +then of course all the ones that we can + + + align:start position:0% +then of course all the ones that we can +actually reach also have this property + + align:start position:0% +actually reach also have this property + + + align:start position:0% +actually reach also have this property +uh so X+ Y is indeed an integer linear + + align:start position:0% +uh so X+ Y is indeed an integer linear + + + align:start position:0% +uh so X+ Y is indeed an integer linear +combination of a uh A and + + align:start position:0% +combination of a uh A and + + + align:start position:0% +combination of a uh A and +B um Etc and of proof okay I don't want + + align:start position:0% +B um Etc and of proof okay I don't want + + + align:start position:0% +B um Etc and of proof okay I don't want +to prove it for for every single + + align:start position:0% +to prove it for for every single + + + align:start position:0% +to prove it for for every single +transition here uh just because there's + + align:start position:0% +transition here uh just because there's + + + align:start position:0% +transition here uh just because there's +a bunch of them but for example a is + + align:start position:0% +a bunch of them but for example a is + + + align:start position:0% +a bunch of them but for example a is +indeed an integer linear combination of + + align:start position:0% +indeed an integer linear combination of + + + align:start position:0% +indeed an integer linear combination of +A and B it's 1 * a plus 0 * B this one + + align:start position:0% +A and B it's 1 * a plus 0 * B this one + + + align:start position:0% +A and B it's 1 * a plus 0 * B this one +looks mess here it's actually just X+ y + + align:start position:0% +looks mess here it's actually just X+ y + + + align:start position:0% +looks mess here it's actually just X+ y +minus B so it's almost the same you just + + align:start position:0% +minus B so it's almost the same you just + + + align:start position:0% +minus B so it's almost the same you just +add a minus one here but the general + + align:start position:0% +add a minus one here but the general + + + align:start position:0% +add a minus one here but the general +property we're using here is that all of + + align:start position:0% +property we're using here is that all of + + + align:start position:0% +property we're using here is that all of +the constructible numbers here are + + align:start position:0% +the constructible numbers here are + + + align:start position:0% +the constructible numbers here are +integer linear combinations of X Y A and + + align:start position:0% +integer linear combinations of X Y A and + + + align:start position:0% +integer linear combinations of X Y A and +B Okay I lied we're using integer linear + + align:start position:0% +B Okay I lied we're using integer linear + + + align:start position:0% +B Okay I lied we're using integer linear +combinations of four things but all of + + align:start position:0% +combinations of four things but all of + + + align:start position:0% +combinations of four things but all of +the X and y's are also integer linear + + align:start position:0% +the X and y's are also integer linear + + + align:start position:0% +the X and y's are also integer linear +combinations of a and B so what we're + + align:start position:0% +combinations of a and B so what we're + + + align:start position:0% +combinations of a and B so what we're +really taking is integer linear + + align:start position:0% +really taking is integer linear + + + align:start position:0% +really taking is integer linear +combinations of integer linear + + align:start position:0% +combinations of integer linear + + + align:start position:0% +combinations of integer linear +combinations of A and B and it turns out + + align:start position:0% +combinations of A and B and it turns out + + + align:start position:0% +combinations of A and B and it turns out +that if you take two integer linear + + align:start position:0% +that if you take two integer linear + + + align:start position:0% +that if you take two integer linear +combinations of A and B like X and Y and + + align:start position:0% +combinations of A and B like X and Y and + + + align:start position:0% +combinations of A and B like X and Y and +you add them together or in general take + + align:start position:0% +you add them together or in general take + + + align:start position:0% +you add them together or in general take +an integer linear combination of them + + align:start position:0% +an integer linear combination of them + + + align:start position:0% +an integer linear combination of them +you still get an integer linear + + align:start position:0% +you still get an integer linear + + + align:start position:0% +you still get an integer linear +combination of A and B as you can see + + align:start position:0% +combination of A and B as you can see + + + align:start position:0% +combination of A and B as you can see +from this proof it's actually pretty + + align:start position:0% +from this proof it's actually pretty + + + align:start position:0% +from this proof it's actually pretty +much the same proof we were doing over + + align:start position:0% +much the same proof we were doing over + + + align:start position:0% +much the same proof we were doing over +here uh this was integer linear + + align:start position:0% +here uh this was integer linear + + + align:start position:0% +here uh this was integer linear +combinations of one number D and + + align:start position:0% +combinations of one number D and + + + align:start position:0% +combinations of one number D and +divisibility was preserved even when you + + align:start position:0% +divisibility was preserved even when you + + + align:start position:0% +divisibility was preserved even when you +took inte linear combinations so same + + align:start position:0% +took inte linear combinations so same + + + align:start position:0% +took inte linear combinations so same +idea and for any puzzle where you have + + align:start position:0% +idea and for any puzzle where you have + + + align:start position:0% +idea and for any puzzle where you have +that property you can only construct + + align:start position:0% +that property you can only construct + + + align:start position:0% +that property you can only construct +numbers that are integer linear + + align:start position:0% +numbers that are integer linear + + + align:start position:0% +numbers that are integer linear +combinations of A and B now for this + + align:start position:0% +combinations of A and B now for this + + + align:start position:0% +combinations of A and B now for this +puzzle you can actually construct all of + + align:start position:0% +puzzle you can actually construct all of + + + align:start position:0% +puzzle you can actually construct all of +them that fit in the + + align:start position:0% +them that fit in the + + + align:start position:0% +them that fit in the +jars uh + + align:start position:0% +jars uh + + + align:start position:0% +jars uh +so I'll just mention this as a claim and + + align:start position:0% +so I'll just mention this as a claim and + + + align:start position:0% +so I'll just mention this as a claim and +if we have time at the end we'll come + + align:start position:0% +if we have time at the end we'll come + + + align:start position:0% +if we have time at the end we'll come +back to + + align:start position:0% +back to + + + align:start position:0% +back to +it uh we + + align:start position:0% +it uh we + + + align:start position:0% +it uh we +can we can + + align:start position:0% +can we can + + + align:start position:0% +can we can +obtain uh a value + + align:start position:0% +obtain uh a value + + + align:start position:0% +obtain uh a value +X um if and only + + align:start position:0% +X um if and only + + + align:start position:0% +X um if and only +if + + align:start position:0% + + + + align:start position:0% + +uh let's say x is an integer linear + + align:start position:0% +uh let's say x is an integer linear + + + align:start position:0% +uh let's say x is an integer linear +combination of A and + + align:start position:0% +combination of A and + + + align:start position:0% +combination of A and +B + + align:start position:0% +B + + + align:start position:0% +B +and + + align:start position:0% +and + + + align:start position:0% +and +uh Z is less than equal to X is less + + align:start position:0% +uh Z is less than equal to X is less + + + align:start position:0% +uh Z is less than equal to X is less +than equal to Max + + align:start position:0% + + + + align:start position:0% + +of okay so we might try to um prove that + + align:start position:0% +of okay so we might try to um prove that + + + align:start position:0% +of okay so we might try to um prove that +later + + align:start position:0% +later + + + align:start position:0% +later +uh so now the central question is how do + + align:start position:0% +uh so now the central question is how do + + + align:start position:0% +uh so now the central question is how do +we know whether one number is an integer + + align:start position:0% +we know whether one number is an integer + + + align:start position:0% +we know whether one number is an integer +linear combination of two other numbers + + align:start position:0% +linear combination of two other numbers + + + align:start position:0% +linear combination of two other numbers +and when it is can we actually construct + + align:start position:0% +and when it is can we actually construct + + + align:start position:0% +and when it is can we actually construct +the values s and t so that sa a plus TB + + align:start position:0% +the values s and t so that sa a plus TB + + + align:start position:0% +the values s and t so that sa a plus TB +equals x because that's what we needed + + align:start position:0% +equals x because that's what we needed + + + align:start position:0% +equals x because that's what we needed +to solve this puzzle was some way to uh + + align:start position:0% +to solve this puzzle was some way to uh + + + align:start position:0% +to solve this puzzle was some way to uh +we were only given the capacities of the + + align:start position:0% +we were only given the capacities of the + + + align:start position:0% +we were only given the capacities of the +jars and the target value and now we + + align:start position:0% +jars and the target value and now we + + + align:start position:0% +jars and the target value and now we +want to represent oh let's check that + + align:start position:0% +want to represent oh let's check that + + + align:start position:0% +want to represent oh let's check that +this is actually possible for this + + align:start position:0% +this is actually possible for this + + + align:start position:0% +this is actually possible for this +example + + align:start position:0% +example + + + align:start position:0% +example +example + + align:start position:0% + + + + align:start position:0% + +uh so if we um sorry not this example + + align:start position:0% +uh so if we um sorry not this example + + + align:start position:0% +uh so if we um sorry not this example +the one that's actually solvable so for + + align:start position:0% +the one that's actually solvable so for + + + align:start position:0% +the one that's actually solvable so for +this solvable puzzle uh 4 equals 2 * 5 + + align:start position:0% +this solvable puzzle uh 4 equals 2 * 5 + + + align:start position:0% +this solvable puzzle uh 4 equals 2 * 5 +that's 10 minus 2 * 3 that's + + align:start position:0% +that's 10 minus 2 * 3 that's + + + align:start position:0% +that's 10 minus 2 * 3 that's +six right 10 - 6 is four so that's + + align:start position:0% +six right 10 - 6 is four so that's + + + align:start position:0% +six right 10 - 6 is four so that's +intuitively why this puzzle is solvable + + align:start position:0% +intuitively why this puzzle is solvable + + + align:start position:0% +intuitively why this puzzle is solvable +although that's not a proof I mean we + + align:start position:0% +although that's not a proof I mean we + + + align:start position:0% +although that's not a proof I mean we +just saw that it wasn't limited by this + + align:start position:0% +just saw that it wasn't limited by this + + + align:start position:0% +just saw that it wasn't limited by this +same issue uh so for example if we + + align:start position:0% +same issue uh so for example if we + + + align:start position:0% +same issue uh so for example if we +started with six and + + align:start position:0% +started with six and + + + align:start position:0% +started with six and +four We Know by this Lemma because two + + align:start position:0% +four We Know by this Lemma because two + + + align:start position:0% +four We Know by this Lemma because two +divides four and two divides six two + + align:start position:0% +divides four and two divides six two + + + align:start position:0% +divides four and two divides six two +will divide any integer linear + + align:start position:0% +will divide any integer linear + + + align:start position:0% +will divide any integer linear +combination and therefore any + + align:start position:0% +combination and therefore any + + + align:start position:0% +combination and therefore any +reachable uh value in this puzzle and + + align:start position:0% +reachable uh value in this puzzle and + + + align:start position:0% +reachable uh value in this puzzle and +two does not divide three three is odd + + align:start position:0% +two does not divide three three is odd + + + align:start position:0% +two does not divide three three is odd +not even and so we will never be able to + + align:start position:0% +not even and so we will never be able to + + + align:start position:0% +not even and so we will never be able to +reach three because all the reachable + + align:start position:0% +reach three because all the reachable + + + align:start position:0% +reach three because all the reachable +states are even that's a corollary now + + align:start position:0% +states are even that's a corollary now + + + align:start position:0% +states are even that's a corollary now +of this + + align:start position:0% +of this + + + align:start position:0% +of this +Lemma okay um + + align:start position:0% +Lemma okay um + + + align:start position:0% +Lemma okay um +okay but how when in the good case in + + align:start position:0% +okay but how when in the good case in + + + align:start position:0% +okay but how when in the good case in +the bad case it's easy to see I guess uh + + align:start position:0% +the bad case it's easy to see I guess uh + + + align:start position:0% +the bad case it's easy to see I guess uh +how how do we know whether we're in a + + align:start position:0% +how how do we know whether we're in a + + + align:start position:0% +how how do we know whether we're in a +good case or a bad case how do we know + + align:start position:0% +good case or a bad case how do we know + + + align:start position:0% +good case or a bad case how do we know +whether X is a integer linear + + align:start position:0% +whether X is a integer linear + + + align:start position:0% +whether X is a integer linear +combination of A and B given X and A and + + align:start position:0% +combination of A and B given X and A and + + + align:start position:0% +combination of A and B given X and A and +B that is kind of the purpose of the + + align:start position:0% +B that is kind of the purpose of the + + + align:start position:0% +B that is kind of the purpose of the +well some motivation for the rest of + + align:start position:0% +well some motivation for the rest of + + + align:start position:0% +well some motivation for the rest of +this lecture we can use it for all sorts + + align:start position:0% +this lecture we can use it for all sorts + + + align:start position:0% +this lecture we can use it for all sorts +of + + align:start position:0% +of + + + align:start position:0% +of +things all right and I claim that this + + align:start position:0% +things all right and I claim that this + + + align:start position:0% +things all right and I claim that this +is going to be true um if and only + + align:start position:0% +is going to be true um if and only + + + align:start position:0% +is going to be true um if and only +if uh + + align:start position:0% +if uh + + + align:start position:0% +if uh +this property is + + align:start position:0% + + + + align:start position:0% + +true so now I'm going to restate this in + + align:start position:0% +true so now I'm going to restate this in + + + align:start position:0% +true so now I'm going to restate this in +terms of divisibility this is this + + align:start position:0% +terms of divisibility this is this + + + align:start position:0% +terms of divisibility this is this +equivalence is not obvious we'll prove + + align:start position:0% +equivalence is not obvious we'll prove + + + align:start position:0% +equivalence is not obvious we'll prove +it by the end of today um so I claim + + align:start position:0% +it by the end of today um so I claim + + + align:start position:0% +it by the end of today um so I claim +what what we really want to shows that + + align:start position:0% +what what we really want to shows that + + + align:start position:0% +what what we really want to shows that +every common divisor of A and B remember + + align:start position:0% +every common divisor of A and B remember + + + align:start position:0% +every common divisor of A and B remember +this is our definition of d is a common + + align:start position:0% +this is our definition of d is a common + + + align:start position:0% +this is our definition of d is a common +divisor + + align:start position:0% +divisor + + + align:start position:0% +divisor +uh common divisor of A and B divides a + + align:start position:0% +uh common divisor of A and B divides a + + + align:start position:0% +uh common divisor of A and B divides a +and it divides B um then it should also + + align:start position:0% +and it divides B um then it should also + + + align:start position:0% +and it divides B um then it should also +divide X so in the example uh we saw + + align:start position:0% +divide X so in the example uh we saw + + + align:start position:0% +divide X so in the example uh we saw +that two was a common divisor of four + + align:start position:0% +that two was a common divisor of four + + + align:start position:0% +that two was a common divisor of four +and six and so two better divide + + align:start position:0% +and six and so two better divide + + + align:start position:0% +and six and so two better divide +anything that we make uh what are the + + align:start position:0% +anything that we make uh what are the + + + align:start position:0% +anything that we make uh what are the +common divisors of five and + + align:start position:0% + + + + align:start position:0% + +three three doesn't work five doesn't + + align:start position:0% +three three doesn't work five doesn't + + + align:start position:0% +three three doesn't work five doesn't +work two doesn't work four doesn't work + + align:start position:0% +work two doesn't work four doesn't work + + + align:start position:0% +work two doesn't work four doesn't work +I guess one is a common divisor one + + align:start position:0% +I guess one is a common divisor one + + + align:start position:0% +I guess one is a common divisor one +divides + + align:start position:0% +divides + + + align:start position:0% +divides +everything uh + + align:start position:0% +everything uh + + + align:start position:0% +everything uh +so yeah that's also this is true in our + + align:start position:0% +so yeah that's also this is true in our + + + align:start position:0% +so yeah that's also this is true in our +in our good case + + align:start position:0% +in our good case + + + align:start position:0% +in our good case +uh and this we can rewrite in yet + + align:start position:0% +uh and this we can rewrite in yet + + + align:start position:0% +uh and this we can rewrite in yet +another way which motivates our next + + align:start position:0% +another way which motivates our next + + + align:start position:0% +another way which motivates our next +topic uh the gcd of A and B divides X + + align:start position:0% +topic uh the gcd of A and B divides X + + + align:start position:0% +topic uh the gcd of A and B divides X +okay so I claim in particular this is + + align:start position:0% +okay so I claim in particular this is + + + align:start position:0% +okay so I claim in particular this is +going to be a way to tell whether X is + + align:start position:0% +going to be a way to tell whether X is + + + align:start position:0% +going to be a way to tell whether X is +an integer linear combination of A and B + + align:start position:0% +an integer linear combination of A and B + + + align:start position:0% +an integer linear combination of A and B +you compute something called the gcd of + + align:start position:0% +you compute something called the gcd of + + + align:start position:0% +you compute something called the gcd of +A and B and you see whether it divides X + + align:start position:0% +A and B and you see whether it divides X + + + align:start position:0% +A and B and you see whether it divides X +so let's talk about gcd + + align:start position:0% + + + + align:start position:0% + +gcd is another acronym it stands for uh + + align:start position:0% +gcd is another acronym it stands for uh + + + align:start position:0% +gcd is another acronym it stands for uh +greatest common + + align:start position:0% + + + + align:start position:0% + +divisor I assume it comes + + align:start position:0% + + + + align:start position:0% + +from uh Britain in particular where they + + align:start position:0% +from uh Britain in particular where they + + + align:start position:0% +from uh Britain in particular where they +use great to to indicate large uh so we + + align:start position:0% +use great to to indicate large uh so we + + + align:start position:0% +use great to to indicate large uh so we +might call call this the largest common + + align:start position:0% +might call call this the largest common + + + align:start position:0% +might call call this the largest common +divisor uh or the biggest common divisor + + align:start position:0% +divisor uh or the biggest common divisor + + + align:start position:0% +divisor uh or the biggest common divisor +all synonyms for the same thing + + align:start position:0% + + + + align:start position:0% + +um so this is the I'm going to give two + + align:start position:0% +um so this is the I'm going to give two + + + align:start position:0% +um so this is the I'm going to give two +equivalent definitions of + + align:start position:0% +equivalent definitions of + + + align:start position:0% +equivalent definitions of +gcd to me the more intuitive one is this + + align:start position:0% + + + + align:start position:0% + +but it's a little bit uglier because it + + align:start position:0% +but it's a little bit uglier because it + + + align:start position:0% +but it's a little bit uglier because it +has a special case so what I'd like to + + align:start position:0% +has a special case so what I'd like to + + + align:start position:0% +has a special case so what I'd like to +say is the gcd of A and B is the largest + + align:start position:0% +say is the gcd of A and B is the largest + + + align:start position:0% +say is the gcd of A and B is the largest +integer D such that D divides A and D + + align:start position:0% +integer D such that D divides A and D + + + align:start position:0% +integer D such that D divides A and D +divides B again this is common common + + align:start position:0% +divides B again this is common common + + + align:start position:0% +divides B again this is common common +divisor D is a common divisor of A and B + + align:start position:0% +divisor D is a common divisor of A and B + + + align:start position:0% +divisor D is a common divisor of A and B +I want it to be the largest common + + align:start position:0% +I want it to be the largest common + + + align:start position:0% +I want it to be the largest common +diviser that would be gcd uh but there's + + align:start position:0% +diviser that would be gcd uh but there's + + + align:start position:0% +diviser that would be gcd uh but there's +one annoying special case which really + + align:start position:0% +one annoying special case which really + + + align:start position:0% +one annoying special case which really +won't matter for the rest of lecture but + + align:start position:0% +won't matter for the rest of lecture but + + + align:start position:0% +won't matter for the rest of lecture but +to be technically correct we should say + + align:start position:0% +to be technically correct we should say + + + align:start position:0% +to be technically correct we should say +what happens when you compute the gcd of + + align:start position:0% +what happens when you compute the gcd of + + + align:start position:0% +what happens when you compute the gcd of +Z and zero because remember every + + align:start position:0% +Z and zero because remember every + + + align:start position:0% +Z and zero because remember every +integer D divides zero everything + + align:start position:0% +integer D divides zero everything + + + align:start position:0% +integer D divides zero everything +divides zero so what's the largest + + align:start position:0% +divides zero so what's the largest + + + align:start position:0% +divides zero so what's the largest +diviser of zero and zero I mean Infinity + + align:start position:0% +diviser of zero and zero I mean Infinity + + + align:start position:0% +diviser of zero and zero I mean Infinity +I don't know it's like there is no such + + align:start position:0% +I don't know it's like there is no such + + + align:start position:0% +I don't know it's like there is no such +integer that's the largest so there is + + align:start position:0% +integer that's the largest so there is + + + align:start position:0% +integer that's the largest so there is +no largest integer uh so in this case it + + align:start position:0% +no largest integer uh so in this case it + + + align:start position:0% +no largest integer uh so in this case it +turns out the right thing is to Define + + align:start position:0% +turns out the right thing is to Define + + + align:start position:0% +turns out the right thing is to Define +gcd of 0 comma 0 to be zero that will be + + align:start position:0% +gcd of 0 comma 0 to be zero that will be + + + align:start position:0% +gcd of 0 comma 0 to be zero that will be +a little counterintuitive maybe uh until + + align:start position:0% +a little counterintuitive maybe uh until + + + align:start position:0% +a little counterintuitive maybe uh until +you see the next + + align:start position:0% + + + + align:start position:0% + +definition Okay so + + align:start position:0% +definition Okay so + + + align:start position:0% +definition Okay so +here's another + + align:start position:0% +here's another + + + align:start position:0% +here's another +definition gcd is uh the only non- + + align:start position:0% +definition gcd is uh the only non- + + + align:start position:0% +definition gcd is uh the only non- +negative common + + align:start position:0% + + + + align:start position:0% + +divisor of A and + + align:start position:0% +divisor of A and + + + align:start position:0% +divisor of A and +B uh divisible by all common divisors of + + align:start position:0% +B uh divisible by all common divisors of + + + align:start position:0% +B uh divisible by all common divisors of +A and B + + align:start position:0% + + + + align:start position:0% + +okay so uh another way to think about + + align:start position:0% +okay so uh another way to think about + + + align:start position:0% +okay so uh another way to think about +the large the greatest common divisor is + + align:start position:0% +the large the greatest common divisor is + + + align:start position:0% +the large the greatest common divisor is +it's greatest in terms of the + + align:start position:0% +it's greatest in terms of the + + + align:start position:0% +it's greatest in terms of the +divisibility relation um the one that is + + align:start position:0% +divisibility relation um the one that is + + + align:start position:0% +divisibility relation um the one that is +uh the most divisible by by other common + + align:start position:0% +uh the most divisible by by other common + + + align:start position:0% +uh the most divisible by by other common +divisors so it turns out there's going + + align:start position:0% +divisors so it turns out there's going + + + align:start position:0% +divisors so it turns out there's going +to be one common divisor that's both + + align:start position:0% +to be one common divisor that's both + + + align:start position:0% +to be one common divisor that's both +non- negative and is divisible by all + + align:start position:0% +non- negative and is divisible by all + + + align:start position:0% +non- negative and is divisible by all +common divisor of A and B uh so in these + + align:start position:0% +common divisor of A and B uh so in these + + + align:start position:0% +common divisor of A and B uh so in these +examples uh for four and six gcd + + align:start position:0% +examples uh for four and six gcd + + + align:start position:0% +examples uh for four and six gcd +of of 6 and four is going to be + + align:start position:0% + + + + align:start position:0% + +two uh because the only let's see the + + align:start position:0% +two uh because the only let's see the + + + align:start position:0% +two uh because the only let's see the +the common divisors if we think what are + + align:start position:0% +the common divisors if we think what are + + + align:start position:0% +the common divisors if we think what are +all the common + + align:start position:0% +all the common + + + align:start position:0% +all the common +divisors between four and + + align:start position:0% +divisors between four and + + + align:start position:0% +divisors between four and +six uh maybe obvious there there's two + + align:start position:0% +six uh maybe obvious there there's two + + + align:start position:0% +six uh maybe obvious there there's two +there's minus two uh there's one and + + align:start position:0% +there's minus two uh there's one and + + + align:start position:0% +there's minus two uh there's one and +minus one zero divides nothing except + + align:start position:0% +minus one zero divides nothing except + + + align:start position:0% +minus one zero divides nothing except +itself and all you can check all the + + align:start position:0% +itself and all you can check all the + + + align:start position:0% +itself and all you can check all the +numbers between like6 and six uh those + + align:start position:0% +numbers between like6 and six uh those + + + align:start position:0% +numbers between like6 and six uh those +are the possible divisors um and uh + + align:start position:0% +are the possible divisors um and uh + + + align:start position:0% +are the possible divisors um and uh +these are the only ones that divide both + + align:start position:0% +these are the only ones that divide both + + + align:start position:0% +these are the only ones that divide both +A and B and the + + align:start position:0% +A and B and the + + + align:start position:0% +A and B and the +largest uh non- negative one here is two + + align:start position:0% +largest uh non- negative one here is two + + + align:start position:0% +largest uh non- negative one here is two +and also it has the property that all of + + align:start position:0% +and also it has the property that all of + + + align:start position:0% +and also it has the property that all of +these other common divisors divide + + align:start position:0% +these other common divisors divide + + + align:start position:0% +these other common divisors divide +two okay so uh whichever way you want to + + align:start position:0% +two okay so uh whichever way you want to + + + align:start position:0% +two okay so uh whichever way you want to +think about it you can use either + + align:start position:0% +think about it you can use either + + + align:start position:0% +think about it you can use either +definition I'm not going to prove that + + align:start position:0% +definition I'm not going to prove that + + + align:start position:0% +definition I'm not going to prove that +these definitions are equivalent we're + + align:start position:0% +these definitions are equivalent we're + + + align:start position:0% +these definitions are equivalent we're +just going to take it as an axiom but + + align:start position:0% +just going to take it as an axiom but + + + align:start position:0% +just going to take it as an axiom but +you can prove it uh this maybe an + + align:start position:0% +you can prove it uh this maybe an + + + align:start position:0% +you can prove it uh this maybe an +exercise + + align:start position:0% +exercise + + + align:start position:0% +exercise +uh so we but when we're proving things + + align:start position:0% +uh so we but when we're proving things + + + align:start position:0% +uh so we but when we're proving things +about gcd we can use either of these + + align:start position:0% +about gcd we can use either of these + + + align:start position:0% +about gcd we can use either of these +definitions whichever is more + + align:start position:0% +definitions whichever is more + + + align:start position:0% +definitions whichever is more +convenient so let's um do one more + + align:start position:0% +convenient so let's um do one more + + + align:start position:0% +convenient so let's um do one more +interesting + + align:start position:0% + + + + align:start position:0% + +example which + + align:start position:0% +example which + + + align:start position:0% +example which +is + + align:start position:0% +is + + + align:start position:0% +is +gcd of I think I want to do zero first Z + + align:start position:0% +gcd of I think I want to do zero first Z + + + align:start position:0% +gcd of I think I want to do zero first Z +comma a so suppose I want to compute gcd + + align:start position:0% +comma a so suppose I want to compute gcd + + + align:start position:0% +comma a so suppose I want to compute gcd +of two numbers maybe I should put a b + + align:start position:0% + + + + align:start position:0% + +there uh and one of them is + + align:start position:0% +there uh and one of them is + + + align:start position:0% +there uh and one of them is +zero any + + align:start position:0% +zero any + + + align:start position:0% +zero any +guesses what the gcd of zero and B + + align:start position:0% +guesses what the gcd of zero and B + + + align:start position:0% +guesses what the gcd of zero and B +should be remember everything divides + + align:start position:0% + + + + align:start position:0% + +zero B is a good guess almost right what + + align:start position:0% +zero B is a good guess almost right what + + + align:start position:0% +zero B is a good guess almost right what +if B was -7 + + align:start position:0% + + + + align:start position:0% + +should be absolute value of B so uh if + + align:start position:0% +should be absolute value of B so uh if + + + align:start position:0% +should be absolute value of B so uh if +we want to handle positive and negative + + align:start position:0% +we want to handle positive and negative + + + align:start position:0% +we want to handle positive and negative +things this turns out to be the right + + align:start position:0% +things this turns out to be the right + + + align:start position:0% +things this turns out to be the right +answer uh here is a mini + + align:start position:0% +answer uh here is a mini + + + align:start position:0% +answer uh here is a mini +proof uh there are two things we want to + + align:start position:0% +proof uh there are two things we want to + + + align:start position:0% +proof uh there are two things we want to +check one is that absolute value of B is + + align:start position:0% +check one is that absolute value of B is + + + align:start position:0% +check one is that absolute value of B is +a common divisor of zero and B uh so + + align:start position:0% +a common divisor of zero and B uh so + + + align:start position:0% +a common divisor of zero and B uh so +well the absolute value of B this gets + + align:start position:0% +well the absolute value of B this gets + + + align:start position:0% +well the absolute value of B this gets +notationally pretty gross divides zero + + align:start position:0% +notationally pretty gross divides zero + + + align:start position:0% +notationally pretty gross divides zero +that's true because everything divides + + align:start position:0% +that's true because everything divides + + + align:start position:0% +that's true because everything divides +zero uh and absolute value of B divides + + align:start position:0% +zero uh and absolute value of B divides + + + align:start position:0% +zero uh and absolute value of B divides +B namely when we let K be uh1 or one + + align:start position:0% +B namely when we let K be uh1 or one + + + align:start position:0% +B namely when we let K be uh1 or one +depending on whether B was positive or + + align:start position:0% +depending on whether B was positive or + + + align:start position:0% +depending on whether B was positive or +negative or + + align:start position:0% +negative or + + + align:start position:0% +negative or +zero um cool so uh good it is a common + + align:start position:0% + + + + align:start position:0% + +divisor and now I want to claim that + + align:start position:0% +divisor and now I want to claim that + + + align:start position:0% +divisor and now I want to claim that +it's the greatest common divisor + + align:start position:0% +it's the greatest common divisor + + + align:start position:0% +it's the greatest common divisor +according to the second definition so + + align:start position:0% +according to the second definition so + + + align:start position:0% +according to the second definition so +let's suppose that we had some number D + + align:start position:0% +let's suppose that we had some number D + + + align:start position:0% +let's suppose that we had some number D +which divides zero and which divides + + align:start position:0% +which divides zero and which divides + + + align:start position:0% +which divides zero and which divides +uh + + align:start position:0% +uh + + + align:start position:0% +uh +B so d divid z and d divides B then uh I + + align:start position:0% +B so d divid z and d divides B then uh I + + + align:start position:0% +B so d divid z and d divides B then uh I +claim in particular D also + + align:start position:0% +claim in particular D also + + + align:start position:0% +claim in particular D also +divides uh the absolute value of + + align:start position:0% +divides uh the absolute value of + + + align:start position:0% +divides uh the absolute value of +B Because if you divide a number you + + align:start position:0% +B Because if you divide a number you + + + align:start position:0% +B Because if you divide a number you +also divide its negation just by + + align:start position:0% +also divide its negation just by + + + align:start position:0% +also divide its negation just by +negating the value K that you're + + align:start position:0% +negating the value K that you're + + + align:start position:0% +negating the value K that you're +multiplying by right if I take K * D and + + align:start position:0% +multiplying by right if I take K * D and + + + align:start position:0% +multiplying by right if I take K * D and +I get b i then I take negative K * D and + + align:start position:0% +I get b i then I take negative K * D and + + + align:start position:0% +I get b i then I take negative K * D and +I get absolute value of B if B happened + + align:start position:0% +I get absolute value of B if B happened + + + align:start position:0% +I get absolute value of B if B happened +to be negative okay so that means if + + align:start position:0% +to be negative okay so that means if + + + align:start position:0% +to be negative okay so that means if +you're a common diviser of zero and B + + align:start position:0% +you're a common diviser of zero and B + + + align:start position:0% +you're a common diviser of zero and B +then you're also a common diviser of + + align:start position:0% +then you're also a common diviser of + + + align:start position:0% +then you're also a common diviser of +this thing and that was our defin second + + align:start position:0% +this thing and that was our defin second + + + align:start position:0% +this thing and that was our defin second +definition of gcd uh so great uh this + + align:start position:0% +definition of gcd uh so great uh this + + + align:start position:0% +definition of gcd uh so great uh this +means we're + + align:start position:0% + + + + align:start position:0% + +greatest okay uh now the the question + + align:start position:0% +greatest okay uh now the the question + + + align:start position:0% +greatest okay uh now the the question +arises how do we compute gcd of A and B + + align:start position:0% +arises how do we compute gcd of A and B + + + align:start position:0% +arises how do we compute gcd of A and B +because I claimed uh + + align:start position:0% +because I claimed uh + + + align:start position:0% +because I claimed uh +over here that what we need to check is + + align:start position:0% +over here that what we need to check is + + + align:start position:0% +over here that what we need to check is +whether gcd of ab divides X so given a + + align:start position:0% +whether gcd of ab divides X so given a + + + align:start position:0% +whether gcd of ab divides X so given a +and b we need to be able to compute this + + align:start position:0% +and b we need to be able to compute this + + + align:start position:0% +and b we need to be able to compute this +thing + + align:start position:0% +thing + + + align:start position:0% +thing +how do we find the greatest common + + align:start position:0% +how do we find the greatest common + + + align:start position:0% +how do we find the greatest common +divisor turns out there's a great + + align:start position:0% +divisor turns out there's a great + + + align:start position:0% +divisor turns out there's a great +algorithm to do it and the base case of + + align:start position:0% +algorithm to do it and the base case of + + + align:start position:0% +algorithm to do it and the base case of +that algorithm is this if we can get one + + align:start position:0% +that algorithm is this if we can get one + + + align:start position:0% +that algorithm is this if we can get one +of the numbers down to zero then that we + + align:start position:0% +of the numbers down to zero then that we + + + align:start position:0% +of the numbers down to zero then that we +found the + + align:start position:0% +found the + + + align:start position:0% +found the +gcd okay so our goal now is given some + + align:start position:0% +gcd okay so our goal now is given some + + + align:start position:0% +gcd okay so our goal now is given some +big numbers to make them smaller + + align:start position:0% +big numbers to make them smaller + + + align:start position:0% +big numbers to make them smaller +somehow and the big idea here to make a + + align:start position:0% +somehow and the big idea here to make a + + + align:start position:0% +somehow and the big idea here to make a +gcd algorithm is + + align:start position:0% +gcd algorithm is + + + align:start position:0% +gcd algorithm is +subtraction how do we make numbers + + align:start position:0% +subtraction how do we make numbers + + + align:start position:0% +subtraction how do we make numbers +smaller with arithmetic subtraction or + + align:start position:0% +smaller with arithmetic subtraction or + + + align:start position:0% +smaller with arithmetic subtraction or +division seem like good ideas we're + + align:start position:0% +division seem like good ideas we're + + + align:start position:0% +division seem like good ideas we're +going to use both starting with + + align:start position:0% +going to use both starting with + + + align:start position:0% +going to use both starting with +subtraction + + align:start position:0% +subtraction + + + align:start position:0% +subtraction +so I + + align:start position:0% +so I + + + align:start position:0% +so I +claim gcd of ab equals gcd of a minus B + + align:start position:0% +claim gcd of ab equals gcd of a minus B + + + align:start position:0% +claim gcd of ab equals gcd of a minus B +comma B comma + + align:start position:0% +comma B comma + + + align:start position:0% +comma B comma +B uh for all integers + + align:start position:0% + + + + align:start position:0% + +a so if a and b are big numbers this is + + align:start position:0% +a so if a and b are big numbers this is + + + align:start position:0% +a so if a and b are big numbers this is +pretty cool this is saying we can + + align:start position:0% +pretty cool this is saying we can + + + align:start position:0% +pretty cool this is saying we can +subtract one of the numbers from the + + align:start position:0% +subtract one of the numbers from the + + + align:start position:0% +subtract one of the numbers from the +other and we get the same gcd somehow + + align:start position:0% +other and we get the same gcd somehow + + + align:start position:0% +other and we get the same gcd somehow +okay we'll prove this in a + + align:start position:0% +okay we'll prove this in a + + + align:start position:0% +okay we'll prove this in a +second now actually going leave a little + + align:start position:0% +second now actually going leave a little + + + align:start position:0% +second now actually going leave a little +bit of space let's do + + align:start position:0% + + + + align:start position:0% + +proof okay so um then we're going to + + align:start position:0% +proof okay so um then we're going to + + + align:start position:0% +proof okay so um then we're going to +turn this into an algorithm but let's + + align:start position:0% +turn this into an algorithm but let's + + + align:start position:0% +turn this into an algorithm but let's +first see why this is the case so + + align:start position:0% + + + + align:start position:0% + +um we this is a statement about GC CD + + align:start position:0% +um we this is a statement about GC CD + + + align:start position:0% +um we this is a statement about GC CD +gcd is this complicated definition uh + + align:start position:0% +gcd is this complicated definition uh + + + align:start position:0% +gcd is this complicated definition uh +it's a little easier to think about all + + align:start position:0% +it's a little easier to think about all + + + align:start position:0% +it's a little easier to think about all +common divisors you think about the + + align:start position:0% +common divisors you think about the + + + align:start position:0% +common divisors you think about the +common divisors of A and B those are all + + align:start position:0% +common divisors of A and B those are all + + + align:start position:0% +common divisors of A and B those are all +the numbers D where D divides A and D + + align:start position:0% +the numbers D where D divides A and D + + + align:start position:0% +the numbers D where D divides A and D +divides B and you think of the common + + align:start position:0% +divides B and you think of the common + + + align:start position:0% +divides B and you think of the common +divisors of a minus B and B I claim + + align:start position:0% +divisors of a minus B and B I claim + + + align:start position:0% +divisors of a minus B and B I claim +these sets are the same so the set of + + align:start position:0% +these sets are the same so the set of + + + align:start position:0% +these sets are the same so the set of +common + + align:start position:0% + + + + align:start position:0% + +divisors of a and + + align:start position:0% +divisors of a and + + + align:start position:0% +divisors of a and +b equals the set of common + + align:start position:0% + + + + align:start position:0% + +divisors of a minus B and + + align:start position:0% +divisors of a minus B and + + + align:start position:0% +divisors of a minus B and +B okay this is a kind of proof we + + align:start position:0% +B okay this is a kind of proof we + + + align:start position:0% +B okay this is a kind of proof we +actually haven't seen in this class yet + + align:start position:0% +actually haven't seen in this class yet + + + align:start position:0% +actually haven't seen in this class yet +uh this is the brace not a minus sign uh + + align:start position:0% +uh this is the brace not a minus sign uh + + + align:start position:0% +uh this is the brace not a minus sign uh +when you want to prove two sets are + + align:start position:0% +when you want to prove two sets are + + + align:start position:0% +when you want to prove two sets are +equal a very common template for such a + + align:start position:0% +equal a very common template for such a + + + align:start position:0% +equal a very common template for such a +proof is to show that every element of + + align:start position:0% +proof is to show that every element of + + + align:start position:0% +proof is to show that every element of +this set is also an element of this set + + align:start position:0% +this set is also an element of this set + + + align:start position:0% +this set is also an element of this set +that if you recall back to our set + + align:start position:0% +that if you recall back to our set + + + align:start position:0% +that if you recall back to our set +definitions in lecture one is that this + + align:start position:0% +definitions in lecture one is that this + + + align:start position:0% +definitions in lecture one is that this +set is contained in this set and also to + + align:start position:0% +set is contained in this set and also to + + + align:start position:0% +set is contained in this set and also to +prove that every element of the second + + align:start position:0% +prove that every element of the second + + + align:start position:0% +prove that every element of the second +set is an element of the first set + + align:start position:0% +set is an element of the first set + + + align:start position:0% +set is an element of the first set +that's saying the second set is a subset + + align:start position:0% +that's saying the second set is a subset + + + align:start position:0% +that's saying the second set is a subset +of the first set so uh we're going to do + + align:start position:0% +of the first set so uh we're going to do + + + align:start position:0% +of the first set so uh we're going to do +a proof in two parts one part one is to + + align:start position:0% +a proof in two parts one part one is to + + + align:start position:0% +a proof in two parts one part one is to +show containment that the first set is + + align:start position:0% +show containment that the first set is + + + align:start position:0% +show containment that the first set is +contained in the second set uh part two + + align:start position:0% +contained in the second set uh part two + + + align:start position:0% +contained in the second set uh part two +over + + align:start position:0% +over + + + align:start position:0% +over +here is to show containment in the other + + align:start position:0% +here is to show containment in the other + + + align:start position:0% +here is to show containment in the other +direction this set is a suet of this set + + align:start position:0% +direction this set is a suet of this set + + + align:start position:0% +direction this set is a suet of this set +okay if I can prove that these sets are + + align:start position:0% +okay if I can prove that these sets are + + + align:start position:0% +okay if I can prove that these sets are +equal then in particular the maximum + + align:start position:0% +equal then in particular the maximum + + + align:start position:0% +equal then in particular the maximum +element of these sets if it exists is + + align:start position:0% +element of these sets if it exists is + + + align:start position:0% +element of these sets if it exists is +also going to be equal right if you have + + align:start position:0% +also going to be equal right if you have + + + align:start position:0% +also going to be equal right if you have +two identical sets you take the max + + align:start position:0% +two identical sets you take the max + + + align:start position:0% +two identical sets you take the max +you're going to get the same thing now + + align:start position:0% +you're going to get the same thing now + + + align:start position:0% +you're going to get the same thing now +there's this one I'm using the first + + align:start position:0% +there's this one I'm using the first + + + align:start position:0% +there's this one I'm using the first +definition here of course there's this + + align:start position:0% +definition here of course there's this + + + align:start position:0% +definition here of course there's this +one case when the two numbers are zero + + align:start position:0% +one case when the two numbers are zero + + + align:start position:0% +one case when the two numbers are zero +then there is no maximum because all + + align:start position:0% +then there is no maximum because all + + + align:start position:0% +then there is no maximum because all +integers actually will be common + + align:start position:0% +integers actually will be common + + + align:start position:0% +integers actually will be common +divisors of zero and zero but in that + + align:start position:0% +divisors of zero and zero but in that + + + align:start position:0% +divisors of zero and zero but in that +case again if the sets are equal that + + align:start position:0% +case again if the sets are equal that + + + align:start position:0% +case again if the sets are equal that +means that A and B or these numbers must + + align:start position:0% +means that A and B or these numbers must + + + align:start position:0% +means that A and B or these numbers must +be zero and then of course these numbers + + align:start position:0% +be zero and then of course these numbers + + + align:start position:0% +be zero and then of course these numbers +are also all zero and this this + + align:start position:0% +are also all zero and this this + + + align:start position:0% +are also all zero and this this +statement is trivially true when + + align:start position:0% +statement is trivially true when + + + align:start position:0% +statement is trivially true when +everything's zero okay it's just saying + + align:start position:0% +everything's zero okay it's just saying + + + align:start position:0% +everything's zero okay it's just saying +gcd of 0 comma 0 equals gcd of 0 comma 0 + + align:start position:0% +gcd of 0 comma 0 equals gcd of 0 comma 0 + + + align:start position:0% +gcd of 0 comma 0 equals gcd of 0 comma 0 +that one I'm fine with but as long as + + align:start position:0% +that one I'm fine with but as long as + + + align:start position:0% +that one I'm fine with but as long as +we're not in the z z case these sets + + align:start position:0% +we're not in the z z case these sets + + + align:start position:0% +we're not in the z z case these sets +will be finite and if they're equal then + + align:start position:0% +will be finite and if they're equal then + + + align:start position:0% +will be finite and if they're equal then +their maximums will be the same so this + + align:start position:0% +their maximums will be the same so this + + + align:start position:0% +their maximums will be the same so this +is all I need to show let's do it in two + + align:start position:0% +is all I need to show let's do it in two + + + align:start position:0% +is all I need to show let's do it in two +parts so first we suppose that we have a + + align:start position:0% +parts so first we suppose that we have a + + + align:start position:0% +parts so first we suppose that we have a +common diviser of A and B so that means + + align:start position:0% +common diviser of A and B so that means + + + align:start position:0% +common diviser of A and B so that means +D divides A and D divides B for some + + align:start position:0% +D divides A and D divides B for some + + + align:start position:0% +D divides A and D divides B for some +number number + + align:start position:0% +number number + + + align:start position:0% +number number +B um well I claim that also D divides a + + align:start position:0% +B um well I claim that also D divides a + + + align:start position:0% +B um well I claim that also D divides a +minus B because a minus B is an integer + + align:start position:0% +minus B because a minus B is an integer + + + align:start position:0% +minus B because a minus B is an integer +linear combination of A and B and we had + + align:start position:0% +linear combination of A and B and we had + + + align:start position:0% +linear combination of A and B and we had +over here in our divisibility fact if D + + align:start position:0% +over here in our divisibility fact if D + + + align:start position:0% +over here in our divisibility fact if D +divides A and D divides B then D divides + + align:start position:0% +divides A and D divides B then D divides + + + align:start position:0% +divides A and D divides B then D divides +every integer linear combination of A + + align:start position:0% +every integer linear combination of A + + + align:start position:0% +every integer linear combination of A +and B so we're plugging in s equal 1 + + align:start position:0% +and B so we're plugging in s equal 1 + + + align:start position:0% +and B so we're plugging in s equal 1 +tals minus one here and we get the D + + align:start position:0% +tals minus one here and we get the D + + + align:start position:0% +tals minus one here and we get the D +divides a minus + + align:start position:0% +divides a minus + + + align:start position:0% +divides a minus +B great so uh we have d divides A and D + + align:start position:0% +B great so uh we have d divides A and D + + + align:start position:0% +B great so uh we have d divides A and D +divid A minus B so in other words uh we + + align:start position:0% +divid A minus B so in other words uh we + + + align:start position:0% +divid A minus B so in other words uh we +have D divid A and D divides a minus B + + align:start position:0% +have D divid A and D divides a minus B + + + align:start position:0% +have D divid A and D divides a minus B +and that sorry wrong one I want to D + + align:start position:0% +and that sorry wrong one I want to D + + + align:start position:0% +and that sorry wrong one I want to D +divides + + align:start position:0% + + + + align:start position:0% + +B and this is the meaning of a common + + align:start position:0% +B and this is the meaning of a common + + + align:start position:0% +B and this is the meaning of a common +divisor of a minus B and B so we we + + align:start position:0% +divisor of a minus B and B so we we + + + align:start position:0% +divisor of a minus B and B so we we +assumed that D was a common divisor of + + align:start position:0% +assumed that D was a common divisor of + + + align:start position:0% +assumed that D was a common divisor of +this we proved that D was a common + + align:start position:0% +this we proved that D was a common + + + align:start position:0% +this we proved that D was a common +divisor of these two numbers therefore + + align:start position:0% +divisor of these two numbers therefore + + + align:start position:0% +divisor of these two numbers therefore +we have containment every element in + + align:start position:0% +we have containment every element in + + + align:start position:0% +we have containment every element in +this set is contained in this set now + + align:start position:0% +this set is contained in this set now + + + align:start position:0% +this set is contained in this set now +let's prove the reverse and that will + + align:start position:0% +let's prove the reverse and that will + + + align:start position:0% +let's prove the reverse and that will +imply that these sets are equal so now + + align:start position:0% +imply that these sets are equal so now + + + align:start position:0% +imply that these sets are equal so now +suppose that D divides a minus B and D + + align:start position:0% +suppose that D divides a minus B and D + + + align:start position:0% +suppose that D divides a minus B and D +divides + + align:start position:0% +divides + + + align:start position:0% +divides +B then I want to show that D divides + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +why any + + align:start position:0% +why any + + + align:start position:0% +why any +suggestions can I use integer linear + + align:start position:0% +suggestions can I use integer linear + + + align:start position:0% +suggestions can I use integer linear +combinations yeah + + align:start position:0% + + + + align:start position:0% + +T equals z I agree if if I put T equals + + align:start position:0% +T equals z I agree if if I put T equals + + + align:start position:0% +T equals z I agree if if I put T equals +0 and S equals 1 then integer this is an + + align:start position:0% +0 and S equals 1 then integer this is an + + + align:start position:0% +0 and S equals 1 then integer this is an +integer linear combination of A and B + + align:start position:0% +integer linear combination of A and B + + + align:start position:0% +integer linear combination of A and B +but in this case I don't know that D + + align:start position:0% +but in this case I don't know that D + + + align:start position:0% +but in this case I don't know that D +divides a that's actually what I want to + + align:start position:0% +divides a that's actually what I want to + + + align:start position:0% +divides a that's actually what I want to +prove so I can't use integer linear + + align:start position:0% +prove so I can't use integer linear + + + align:start position:0% +prove so I can't use integer linear +combinations of A and B but you do Aus I + + align:start position:0% +combinations of A and B but you do Aus I + + + align:start position:0% +combinations of A and B but you do Aus I +can take an integer linear combination + + align:start position:0% +can take an integer linear combination + + + align:start position:0% +can take an integer linear combination +of a minus B and B if I do 1 * this uh + + align:start position:0% +of a minus B and B if I do 1 * this uh + + + align:start position:0% +of a minus B and B if I do 1 * this uh +Plus 1 * this a - b * 1 + 1 * B is + + align:start position:0% +Plus 1 * this a - b * 1 + 1 * B is + + + align:start position:0% +Plus 1 * this a - b * 1 + 1 * B is +a uh so in other words because this + + align:start position:0% +a uh so in other words because this + + + align:start position:0% +a uh so in other words because this +equals the sum a minus B plus + + align:start position:0% +equals the sum a minus B plus + + + align:start position:0% +equals the sum a minus B plus +b and because I know that D is a common + + align:start position:0% +b and because I know that D is a common + + + align:start position:0% +b and because I know that D is a common +divisor of a minus B and B I know that D + + align:start position:0% +divisor of a minus B and B I know that D + + + align:start position:0% +divisor of a minus B and B I know that D +also divides any interger linear + + align:start position:0% +also divides any interger linear + + + align:start position:0% +also divides any interger linear +combination of those two numbers and in + + align:start position:0% +combination of those two numbers and in + + + align:start position:0% +combination of those two numbers and in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +a cool so so both of these are using the + + align:start position:0% +a cool so so both of these are using the + + + align:start position:0% +a cool so so both of these are using the +uh divisibility facts that if you have a + + align:start position:0% +uh divisibility facts that if you have a + + + align:start position:0% +uh divisibility facts that if you have a +common divisor you also divide all + + align:start position:0% +common divisor you also divide all + + + align:start position:0% +common divisor you also divide all +integer linear combinations of those two + + align:start position:0% +integer linear combinations of those two + + + align:start position:0% +integer linear combinations of those two +numbers uh so in particular this means + + align:start position:0% +numbers uh so in particular this means + + + align:start position:0% +numbers uh so in particular this means +we have D divides A and D divides B I'm + + align:start position:0% +we have D divides A and D divides B I'm + + + align:start position:0% +we have D divides A and D divides B I'm +just taking this thing that we proved + + align:start position:0% +just taking this thing that we proved + + + align:start position:0% +just taking this thing that we proved +and this thing that we + + align:start position:0% +and this thing that we + + + align:start position:0% +and this thing that we +assumed and this says we have a common + + align:start position:0% +assumed and this says we have a common + + + align:start position:0% +assumed and this says we have a common +if we had saying if we had a common + + align:start position:0% +if we had saying if we had a common + + + align:start position:0% +if we had saying if we had a common +divisor of a minus B and B we also have + + align:start position:0% +divisor of a minus B and B we also have + + + align:start position:0% +divisor of a minus B and B we also have +a common divisor of A and B so that says + + align:start position:0% +a common divisor of A and B so that says + + + align:start position:0% +a common divisor of A and B so that says +every element in this second set is an + + align:start position:0% +every element in this second set is an + + + align:start position:0% +every element in this second set is an +element of the first set and because we + + align:start position:0% +element of the first set and because we + + + align:start position:0% +element of the first set and because we +have containment in both directions in + + align:start position:0% +have containment in both directions in + + + align:start position:0% +have containment in both directions in +fact these two sets must be exactly the + + align:start position:0% +fact these two sets must be exactly the + + + align:start position:0% +fact these two sets must be exactly the +same set so if you ever have to prove + + align:start position:0% +same set so if you ever have to prove + + + align:start position:0% +same set so if you ever have to prove +the two sets are equal I recommend a + + align:start position:0% +the two sets are equal I recommend a + + + align:start position:0% +the two sets are equal I recommend a +common template is to do it in two + + align:start position:0% +common template is to do it in two + + + align:start position:0% +common template is to do it in two +halves like + + align:start position:0% +halves like + + + align:start position:0% +halves like +this + + align:start position:0% +this + + + align:start position:0% +this +okay great uh so I claim we can get an + + align:start position:0% +okay great uh so I claim we can get an + + + align:start position:0% +okay great uh so I claim we can get an +algorithm out of + + align:start position:0% +algorithm out of + + + align:start position:0% +algorithm out of +this out of this subtraction idea and + + align:start position:0% +this out of this subtraction idea and + + + align:start position:0% +this out of this subtraction idea and +gcd of 0 comma B + + align:start position:0% +gcd of 0 comma B + + + align:start position:0% +gcd of 0 comma B +so let's just do an example of that I + + align:start position:0% +so let's just do an example of that I + + + align:start position:0% +so let's just do an example of that I +won't write a careful algorithm because + + align:start position:0% +won't write a careful algorithm because + + + align:start position:0% +won't write a careful algorithm because +we're going to do + + align:start position:0% +we're going to do + + + align:start position:0% +we're going to do +better let's say we want to do uh gcd of + + align:start position:0% +better let's say we want to do uh gcd of + + + align:start position:0% +better let's say we want to do uh gcd of +9 comma + + align:start position:0% +9 comma + + + align:start position:0% +9 comma +6 okay uh oh and maybe I want to write + + align:start position:0% +6 okay uh oh and maybe I want to write + + + align:start position:0% +6 okay uh oh and maybe I want to write +another fact + + align:start position:0% +another fact + + + align:start position:0% +another fact +here um does it + + align:start position:0% +here um does it + + + align:start position:0% +here um does it +matter yeah I do uh so gcd of a comma B + + align:start position:0% +matter yeah I do uh so gcd of a comma B + + + align:start position:0% +matter yeah I do uh so gcd of a comma B +is also equal to uh gcd of B comma a by + + align:start position:0% +is also equal to uh gcd of B comma a by + + + align:start position:0% +is also equal to uh gcd of B comma a by +symmetry of this definition A and B + + align:start position:0% +symmetry of this definition A and B + + + align:start position:0% +symmetry of this definition A and B +could be swapped and you get exactly the + + align:start position:0% +could be swapped and you get exactly the + + + align:start position:0% +could be swapped and you get exactly the +same things we're talking about and if I + + align:start position:0% +same things we're talking about and if I + + + align:start position:0% +same things we're talking about and if I +apply this subtraction Lemma uh with the + + align:start position:0% +apply this subtraction Lemma uh with the + + + align:start position:0% +apply this subtraction Lemma uh with the +elements swapped what I get is uh gcd of + + align:start position:0% +elements swapped what I get is uh gcd of + + + align:start position:0% +elements swapped what I get is uh gcd of +the first argument which is B minus the + + align:start position:0% +the first argument which is B minus the + + + align:start position:0% +the first argument which is B minus the +second argument which is a comma the + + align:start position:0% +second argument which is a comma the + + + align:start position:0% +second argument which is a comma the +second argument which is a + + align:start position:0% +second argument which is a + + + align:start position:0% +second argument which is a +so um all these things are equal just + + align:start position:0% +so um all these things are equal just + + + align:start position:0% +so um all these things are equal just +from the same subtraction LMA and using + + align:start position:0% +from the same subtraction LMA and using + + + align:start position:0% +from the same subtraction LMA and using +the Symmetry uh but what this is saying + + align:start position:0% +the Symmetry uh but what this is saying + + + align:start position:0% +the Symmetry uh but what this is saying +is either I can subtract the second + + align:start position:0% +is either I can subtract the second + + + align:start position:0% +is either I can subtract the second +argument from the first and get a minus + + align:start position:0% +argument from the first and get a minus + + + align:start position:0% +argument from the first and get a minus +b or uh I I can also rewrite this as gcd + + align:start position:0% +b or uh I I can also rewrite this as gcd + + + align:start position:0% +b or uh I I can also rewrite this as gcd +of a comma B minus a alternatively I + + align:start position:0% +of a comma B minus a alternatively I + + + align:start position:0% +of a comma B minus a alternatively I +could leave the first argument alone and + + align:start position:0% +could leave the first argument alone and + + + align:start position:0% +could leave the first argument alone and +subtract it from the second argument so + + align:start position:0% +subtract it from the second argument so + + + align:start position:0% +subtract it from the second argument so +I'm free to subtract whichever way I + + align:start position:0% +I'm free to subtract whichever way I + + + align:start position:0% +I'm free to subtract whichever way I +want and I find it much easier to think + + align:start position:0% +want and I find it much easier to think + + + align:start position:0% +want and I find it much easier to think +about non- negative numbers so I'm + + align:start position:0% +about non- negative numbers so I'm + + + align:start position:0% +about non- negative numbers so I'm +always going to subtract the smaller + + align:start position:0% +always going to subtract the smaller + + + align:start position:0% +always going to subtract the smaller +number from the bigger number I can do + + align:start position:0% +number from the bigger number I can do + + + align:start position:0% +number from the bigger number I can do +it either way so let's do it + + align:start position:0% +it either way so let's do it + + + align:start position:0% +it either way so let's do it +for uh 9 comma + + align:start position:0% +for uh 9 comma + + + align:start position:0% +for uh 9 comma +6 so I'm going to subtract six from 9 + + align:start position:0% +6 so I'm going to subtract six from 9 + + + align:start position:0% +6 so I'm going to subtract six from 9 +and I get this is equal to so this would + + align:start position:0% +and I get this is equal to so this would + + + align:start position:0% +and I get this is equal to so this would +be uh a minus B this one minus this one + + align:start position:0% +be uh a minus B this one minus this one + + + align:start position:0% +be uh a minus B this one minus this one +uh is three 9 - 6 is three second + + align:start position:0% +uh is three 9 - 6 is three second + + + align:start position:0% +uh is three 9 - 6 is three second +argument stays the same okay I still + + align:start position:0% +argument stays the same okay I still + + + align:start position:0% +argument stays the same okay I still +don't know the answer so I'm going to + + align:start position:0% +don't know the answer so I'm going to + + + align:start position:0% +don't know the answer so I'm going to +keep subtracting in this case I'll take + + align:start position:0% +keep subtracting in this case I'll take + + + align:start position:0% +keep subtracting in this case I'll take +the smaller number subtract it from the + + align:start position:0% +the smaller number subtract it from the + + + align:start position:0% +the smaller number subtract it from the +larger number so this is uh B minus a I + + align:start position:0% +larger number so this is uh B minus a I + + + align:start position:0% +larger number so this is uh B minus a I +guess replacing B with B minus a I get + + align:start position:0% +guess replacing B with B minus a I get + + + align:start position:0% +guess replacing B with B minus a I get +gcd + + align:start position:0% +gcd + + + align:start position:0% +gcd +of sorry uh I wanted yeah 3 comma + + align:start position:0% +of sorry uh I wanted yeah 3 comma + + + align:start position:0% +of sorry uh I wanted yeah 3 comma +3 subtract three from six I get three + + align:start position:0% +3 subtract three from six I get three + + + align:start position:0% +3 subtract three from six I get three +okay this that looks pretty easy I'm + + align:start position:0% +okay this that looks pretty easy I'm + + + align:start position:0% +okay this that looks pretty easy I'm +guessing gcd of three and three is three + + align:start position:0% +guessing gcd of three and three is three + + + align:start position:0% +guessing gcd of three and three is three +uh but if we go all the way uh we can + + align:start position:0% +uh but if we go all the way uh we can + + + align:start position:0% +uh but if we go all the way uh we can +subtract one of them from the other I + + align:start position:0% +subtract one of them from the other I + + + align:start position:0% +subtract one of them from the other I +guess I want to do B minus a again and + + align:start position:0% +guess I want to do B minus a again and + + + align:start position:0% +guess I want to do B minus a again and +we get 3 comma 0 and this we actually + + align:start position:0% +we get 3 comma 0 and this we actually + + + align:start position:0% +we get 3 comma 0 and this we actually +analyzed over here uh we said gcd oh I + + align:start position:0% +analyzed over here uh we said gcd oh I + + + align:start position:0% +analyzed over here uh we said gcd oh I +got it backwards but of zero comma + + align:start position:0% +got it backwards but of zero comma + + + align:start position:0% +got it backwards but of zero comma +something is the absolute value of + + align:start position:0% +something is the absolute value of + + + align:start position:0% +something is the absolute value of +something so absolute value of three is + + align:start position:0% +something so absolute value of three is + + + align:start position:0% +something so absolute value of three is +three and so gcd of three comma 0 is + + align:start position:0% +three and so gcd of three comma 0 is + + + align:start position:0% +three and so gcd of three comma 0 is +three okay great uh another + + align:start position:0% +three okay great uh another + + + align:start position:0% +three okay great uh another +example gcd of 1 comma + + align:start position:0% +example gcd of 1 comma + + + align:start position:0% +example gcd of 1 comma +100 okay well I take the smaller one + + align:start position:0% +100 okay well I take the smaller one + + + align:start position:0% +100 okay well I take the smaller one +subtract it from the larger one I get + + align:start position:0% +subtract it from the larger one I get + + + align:start position:0% +subtract it from the larger one I get +gcd of 1 comma + + align:start position:0% +gcd of 1 comma + + + align:start position:0% +gcd of 1 comma +99 H okay now I subtract one from the + + align:start position:0% +99 H okay now I subtract one from the + + + align:start position:0% +99 H okay now I subtract one from the +larger number I get gcd of 1 comma + + align:start position:0% +larger number I get gcd of 1 comma + + + align:start position:0% +larger number I get gcd of 1 comma +98 and so on I won't bore you with the + + align:start position:0% +98 and so on I won't bore you with the + + + align:start position:0% +98 and so on I won't bore you with the +details in the end the answer is one but + + align:start position:0% +details in the end the answer is one but + + + align:start position:0% +details in the end the answer is one but +uh this is a very slow way to arrive at + + align:start position:0% +uh this is a very slow way to arrive at + + + align:start position:0% +uh this is a very slow way to arrive at +the answer of one um I have to do a 100 + + align:start position:0% +the answer of one um I have to do a 100 + + + align:start position:0% +the answer of one um I have to do a 100 +steps to figure out the gcd of 1 comma + + align:start position:0% +steps to figure out the gcd of 1 comma + + + align:start position:0% +steps to figure out the gcd of 1 comma +100 so the number of steps you get in + + align:start position:0% +100 so the number of steps you get in + + + align:start position:0% +100 so the number of steps you get in +this algorithm which I haven't precis + + align:start position:0% +this algorithm which I haven't precis + + + align:start position:0% +this algorithm which I haven't precis +defined is going to be uh roughly at + + align:start position:0% +defined is going to be uh roughly at + + + align:start position:0% +defined is going to be uh roughly at +least in the worst case um the sum of a + + align:start position:0% +least in the worst case um the sum of a + + + align:start position:0% +least in the worst case um the sum of a +and b or the maximum of A and B it + + align:start position:0% +and b or the maximum of A and B it + + + align:start position:0% +and b or the maximum of A and B it +doesn't matter up to constant factors uh + + align:start position:0% +doesn't matter up to constant factors uh + + + align:start position:0% +doesn't matter up to constant factors uh +and this is what we would call a slow + + align:start position:0% +and this is what we would call a slow + + + align:start position:0% +and this is what we would call a slow +algorithm for in number + + align:start position:0% +algorithm for in number + + + align:start position:0% +algorithm for in number +Theory because generally we want to + + align:start position:0% +Theory because generally we want to + + + align:start position:0% +Theory because generally we want to +think about numbers that are huge you + + align:start position:0% +think about numbers that are huge you + + + align:start position:0% +think about numbers that are huge you +know uh 100 bits long if you have a 100 + + align:start position:0% +know uh 100 bits long if you have a 100 + + + align:start position:0% +know uh 100 bits long if you have a 100 +bit long number that is as large as two + + align:start position:0% +bit long number that is as large as two + + + align:start position:0% +bit long number that is as large as two +to the 100 + + align:start position:0% +to the 100 + + + align:start position:0% +to the 100 +and that's a very large number uh + + align:start position:0% +and that's a very large number uh + + + align:start position:0% +and that's a very large number uh +it's big roughly the number of particles + + align:start position:0% +it's big roughly the number of particles + + + align:start position:0% +it's big roughly the number of particles +in the known universe I think that's + + align:start position:0% +in the known universe I think that's + + + align:start position:0% +in the known universe I think that's +about to the 128 or something so we + + align:start position:0% +about to the 128 or something so we + + + align:start position:0% +about to the 128 or something so we +don't want to spend that much time uh to + + align:start position:0% +don't want to spend that much time uh to + + + align:start position:0% +don't want to spend that much time uh to +compute this in fact we can do a lot + + align:start position:0% +compute this in fact we can do a lot + + + align:start position:0% +compute this in fact we can do a lot +better using + + align:start position:0% +better using + + + align:start position:0% +better using +a better technique which is division so + + align:start position:0% +a better technique which is division so + + + align:start position:0% +a better technique which is division so +we've seen here uh the idea that we can + + align:start position:0% +we've seen here uh the idea that we can + + + align:start position:0% +we've seen here uh the idea that we can +subtract one number from the other but + + align:start position:0% +subtract one number from the other but + + + align:start position:0% +subtract one number from the other but +if we subtract and then subtract and + + align:start position:0% +if we subtract and then subtract and + + + align:start position:0% +if we subtract and then subtract and +then we subtract and we subtract that + + align:start position:0% +then we subtract and we subtract that + + + align:start position:0% +then we subtract and we subtract that +sounds a lot like division right this is + + align:start position:0% +sounds a lot like division right this is + + + align:start position:0% +sounds a lot like division right this is +like the bad way to do division is to + + align:start position:0% +like the bad way to do division is to + + + align:start position:0% +like the bad way to do division is to +repeatedly subtract one number from the + + align:start position:0% +repeatedly subtract one number from the + + + align:start position:0% +repeatedly subtract one number from the +other and that's exactly what happens in + + align:start position:0% +other and that's exactly what happens in + + + align:start position:0% +other and that's exactly what happens in +the 100 comma one case we have to + + align:start position:0% +the 100 comma one case we have to + + + align:start position:0% +the 100 comma one case we have to +subtract one from 100 subtract it from + + align:start position:0% +subtract one from 100 subtract it from + + + align:start position:0% +subtract one from 100 subtract it from +99 keep subtracting one until the left + + align:start position:0% +99 keep subtracting one until the left + + + align:start position:0% +99 keep subtracting one until the left +hand side uh becomes larger than the + + align:start position:0% +hand side uh becomes larger than the + + + align:start position:0% +hand side uh becomes larger than the +right hand side and then we can stop in + + align:start position:0% +right hand side and then we can stop in + + + align:start position:0% +right hand side and then we can stop in +fact they become equal because one + + align:start position:0% +fact they become equal because one + + + align:start position:0% +fact they become equal because one +divides 100 uh but in general we want to + + align:start position:0% +divides 100 uh but in general we want to + + + align:start position:0% +divides 100 uh but in general we want to +keep subtracting on until we go beyond + + align:start position:0% +keep subtracting on until we go beyond + + + align:start position:0% +keep subtracting on until we go beyond +or we would go beyond what we can afford + + align:start position:0% +or we would go beyond what we can afford + + + align:start position:0% +or we would go beyond what we can afford +and that's exactly division so let me + + align:start position:0% +and that's exactly division so let me + + + align:start position:0% +and that's exactly division so let me +give + + align:start position:0% +give + + + align:start position:0% +give +you a very precise version of + + align:start position:0% + + + + align:start position:0% + +division with something called the + + align:start position:0% +division with something called the + + + align:start position:0% +division with something called the +division theorem this is one of the core + + align:start position:0% +division theorem this is one of the core + + + align:start position:0% +division theorem this is one of the core +theorems + + align:start position:0% +theorems + + + align:start position:0% +theorems +in number Theory we won't prove it here + + align:start position:0% +in number Theory we won't prove it here + + + align:start position:0% +in number Theory we won't prove it here +it's kind of TS um for every integer n + + align:start position:0% +it's kind of TS um for every integer n + + + align:start position:0% +it's kind of TS um for every integer n +and for every positive integer D so I'm + + align:start position:0% +and for every positive integer D so I'm + + + align:start position:0% +and for every positive integer D so I'm +going to write z+ to mean uh D is + + align:start position:0% +going to write z+ to mean uh D is + + + align:start position:0% +going to write z+ to mean uh D is +greater than + + align:start position:0% +greater than + + + align:start position:0% +greater than +zero + + align:start position:0% + + + + align:start position:0% + +uh there is a + + align:start position:0% + + + + align:start position:0% + +unique + + align:start position:0% +unique + + + align:start position:0% +unique +um and usually we would write this as + + align:start position:0% +um and usually we would write this as + + + align:start position:0% +um and usually we would write this as +exists exclamation mark there is a + + align:start position:0% +exists exclamation mark there is a + + + align:start position:0% +exists exclamation mark there is a +unique so you know this means there is + + align:start position:0% +unique so you know this means there is + + + align:start position:0% +unique so you know this means there is +exclamation mark it's really exists but + + align:start position:0% +exclamation mark it's really exists but + + + align:start position:0% +exclamation mark it's really exists but +there's only one of them uh there exists + + align:start position:0% +there's only one of them uh there exists + + + align:start position:0% +there's only one of them uh there exists +a unique uh pair of + + align:start position:0% +a unique uh pair of + + + align:start position:0% +a unique uh pair of +integers uh q and + + align:start position:0% +integers uh q and + + + align:start position:0% +integers uh q and +R uh I don't want the parentheses + + align:start position:0% +R uh I don't want the parentheses + + + align:start position:0% +R uh I don't want the parentheses +actually uh I want to say those are both + + align:start position:0% +actually uh I want to say those are both + + + align:start position:0% +actually uh I want to say those are both +integers um such + + align:start position:0% + + + + align:start position:0% + +that and n = q * D + + + align:start position:0% +that and n = q * D + + + + align:start position:0% +that and n = q * D + +R and R is between zero and strictly + + align:start position:0% +R and R is between zero and strictly + + + align:start position:0% +R and R is between zero and strictly +less than + + align:start position:0% +less than + + + align:start position:0% +less than +D okay you actually have seen this in + + align:start position:0% +D okay you actually have seen this in + + + align:start position:0% +D okay you actually have seen this in +other terms probably before uh this Q is + + align:start position:0% +other terms probably before uh this Q is + + + align:start position:0% +other terms probably before uh this Q is +what we would call the + + align:start position:0% +what we would call the + + + align:start position:0% +what we would call the +quotient and this R is what we call the + + align:start position:0% +quotient and this R is what we call the + + + align:start position:0% +quotient and this R is what we call the +remainder I'm sure you've heard those + + align:start position:0% +remainder I'm sure you've heard those + + + align:start position:0% +remainder I'm sure you've heard those +terms before this is like a very precise + + align:start position:0% +terms before this is like a very precise + + + align:start position:0% +terms before this is like a very precise +way to say what division gives us in all + + align:start position:0% +way to say what division gives us in all + + + align:start position:0% +way to say what division gives us in all +cases + + align:start position:0% +cases + + + align:start position:0% +cases +given uh a numerator and a + + align:start position:0% +given uh a numerator and a + + + align:start position:0% +given uh a numerator and a +denominator that's why they're called n + + align:start position:0% +denominator that's why they're called n + + + align:start position:0% +denominator that's why they're called n +and D here um and as long as D is uh not + + align:start position:0% +and D here um and as long as D is uh not + + + align:start position:0% +and D here um and as long as D is uh not +zero we're going to furthermore assume + + align:start position:0% +zero we're going to furthermore assume + + + align:start position:0% +zero we're going to furthermore assume +that it's positive so it's easier to + + align:start position:0% +that it's positive so it's easier to + + + align:start position:0% +that it's positive so it's easier to +think about um then there's a unique + + align:start position:0% +think about um then there's a unique + + + align:start position:0% +think about um then there's a unique +quotient and remainder you get from + + align:start position:0% +quotient and remainder you get from + + + align:start position:0% +quotient and remainder you get from +dividing A over + + align:start position:0% +dividing A over + + + align:start position:0% +dividing A over +B right Q is how many whole copies of D + + align:start position:0% +B right Q is how many whole copies of D + + + align:start position:0% +B right Q is how many whole copies of D +you can fit inside n and R is whatever + + align:start position:0% +you can fit inside n and R is whatever + + + align:start position:0% +you can fit inside n and R is whatever +is left over so that's roughly a proof + + align:start position:0% +is left over so that's roughly a proof + + + align:start position:0% +is left over so that's roughly a proof +that this is true um and it if you think + + align:start position:0% +that this is true um and it if you think + + + align:start position:0% +that this is true um and it if you think +about what the remainder should be it + + align:start position:0% +about what the remainder should be it + + + align:start position:0% +about what the remainder should be it +could be zero in the zero case that's + + align:start position:0% +could be zero in the zero case that's + + + align:start position:0% +could be zero in the zero case that's +when we have divisibility right if D + + align:start position:0% +when we have divisibility right if D + + + align:start position:0% +when we have divisibility right if D +divides n if n equals Q * D that's + + align:start position:0% +divides n if n equals Q * D that's + + + align:start position:0% +divides n if n equals Q * D that's +exactly divisibility if there's no R + + align:start position:0% +exactly divisibility if there's no R + + + align:start position:0% +exactly divisibility if there's no R +that's when R equals z that's what we + + align:start position:0% +that's when R equals z that's what we + + + align:start position:0% +that's when R equals z that's what we +get uh but in general we know R should + + align:start position:0% +get uh but in general we know R should + + + align:start position:0% +get uh but in general we know R should +also be less than D because if if there + + align:start position:0% +also be less than D because if if there + + + align:start position:0% +also be less than D because if if there +was D left over we would just increase Q + + align:start position:0% +was D left over we would just increase Q + + + align:start position:0% +was D left over we would just increase Q +one that would be a whole copy of D so + + align:start position:0% +one that would be a whole copy of D so + + + align:start position:0% +one that would be a whole copy of D so +the remainder is always going to be + + align:start position:0% +the remainder is always going to be + + + align:start position:0% +the remainder is always going to be +between zero and strictly less than + + align:start position:0% +between zero and strictly less than + + + align:start position:0% +between zero and strictly less than +D okay uh I guess the the interesting + + align:start position:0% +D okay uh I guess the the interesting + + + align:start position:0% +D okay uh I guess the the interesting +part here is that there's only one sorry + + align:start position:0% +part here is that there's only one sorry + + + align:start position:0% +part here is that there's only one sorry +I should have put an i in unique uh + + align:start position:0% +I should have put an i in unique uh + + + align:start position:0% +I should have put an i in unique uh +there's only one way to do this um that + + align:start position:0% +there's only one way to do this um that + + + align:start position:0% +there's only one way to do this um that +with these conditions there's only one + + align:start position:0% +with these conditions there's only one + + + align:start position:0% +with these conditions there's only one +uh quotient and + + align:start position:0% +uh quotient and + + + align:start position:0% +uh quotient and +remainder okay uh I also want to give + + align:start position:0% +remainder okay uh I also want to give + + + align:start position:0% +remainder okay uh I also want to give +you some definitions some notation + + align:start position:0% + + + + align:start position:0% + +which is uh for the quotient we write + + align:start position:0% +which is uh for the quotient we write + + + align:start position:0% +which is uh for the quotient we write +the numerator div D div for division uh + + align:start position:0% +the numerator div D div for division uh + + + align:start position:0% +the numerator div D div for division uh +and for the remainder we write n remd + + align:start position:0% +and for the remainder we write n remd + + + align:start position:0% +and for the remainder we write n remd +REM for + + align:start position:0% +REM for + + + align:start position:0% +REM for +remainder uh this is also sometimes + + align:start position:0% +remainder uh this is also sometimes + + + align:start position:0% +remainder uh this is also sometimes +called n mod D so if you ever see that + + align:start position:0% +called n mod D so if you ever see that + + + align:start position:0% +called n mod D so if you ever see that +we probably won't use it in this form + + align:start position:0% +we probably won't use it in this form + + + align:start position:0% +we probably won't use it in this form +we're going to use mod to mean a + + align:start position:0% +we're going to use mod to mean a + + + align:start position:0% +we're going to use mod to mean a +slightly related slightly different + + align:start position:0% +slightly related slightly different + + + align:start position:0% +slightly related slightly different +notion um also the textbook uh they + + align:start position:0% +notion um also the textbook uh they + + + align:start position:0% +notion um also the textbook uh they +write REM as a as a two argument + + align:start position:0% +write REM as a as a two argument + + + align:start position:0% +write REM as a as a two argument +function but same + + align:start position:0% +function but same + + + align:start position:0% +function but same +idea okay so uh we're going to use + + align:start position:0% +idea okay so uh we're going to use + + + align:start position:0% +idea okay so uh we're going to use +division theorem a lot from now on and + + align:start position:0% +division theorem a lot from now on and + + + align:start position:0% +division theorem a lot from now on and +as a way to uh reduce our numbers again + + align:start position:0% +as a way to uh reduce our numbers again + + + align:start position:0% +as a way to uh reduce our numbers again +in a more powerful way than subtraction + + align:start position:0% +in a more powerful way than subtraction + + + align:start position:0% +in a more powerful way than subtraction +so we would like to do subtraction + + align:start position:0% +so we would like to do subtraction + + + align:start position:0% +so we would like to do subtraction +repeatedly and what will we be left with + + align:start position:0% +repeatedly and what will we be left with + + + align:start position:0% +repeatedly and what will we be left with +we'll be left with the remainder if you + + align:start position:0% +we'll be left with the remainder if you + + + align:start position:0% +we'll be left with the remainder if you +keep subtracting until you can't + + align:start position:0% +keep subtracting until you can't + + + align:start position:0% +keep subtracting until you can't +subtract anymore that's remainder + + align:start position:0% +subtract anymore that's remainder + + + align:start position:0% +subtract anymore that's remainder +okay so let's do + + align:start position:0% +okay so let's do + + + align:start position:0% +okay so let's do +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +that probably still need this + + align:start position:0% +that probably still need this + + + align:start position:0% +that probably still need this +divisibility facts I'll leave it + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% + + + + align:start position:0% + +okay so this is gcd + + align:start position:0% + + + + align:start position:0% + +division + + align:start position:0% +division + + + align:start position:0% +division +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +um if let's suppose a is less than or + + align:start position:0% +um if let's suppose a is less than or + + + align:start position:0% +um if let's suppose a is less than or +equal to B is less than or equal to + + align:start position:0% +equal to B is less than or equal to + + + align:start position:0% +equal to B is less than or equal to +one that what I want no way around that + + align:start position:0% +one that what I want no way around that + + + align:start position:0% +one that what I want no way around that +seems weird be weird to be at most one I + + align:start position:0% +seems weird be weird to be at most one I + + + align:start position:0% +seems weird be weird to be at most one I +want things to be non- negative so I'm + + align:start position:0% +want things to be non- negative so I'm + + + align:start position:0% +want things to be non- negative so I'm +going to assume a is the bigger one of A + + align:start position:0% +going to assume a is the bigger one of A + + + align:start position:0% +going to assume a is the bigger one of A +and B and I want to compute gcd of a + + align:start position:0% +and B and I want to compute gcd of a + + + align:start position:0% +and B and I want to compute gcd of a +comma + + align:start position:0% + + + + align:start position:0% + +B and I'm going to assume we haven't + + align:start position:0% +B and I'm going to assume we haven't + + + align:start position:0% +B and I'm going to assume we haven't +gotten down to zero in particular + + align:start position:0% +gotten down to zero in particular + + + align:start position:0% +gotten down to zero in particular +because I can't divide by zero uh but + + align:start position:0% +because I can't divide by zero uh but + + + align:start position:0% +because I can't divide by zero uh but +also because when we get to zero we're + + align:start position:0% +also because when we get to zero we're + + + align:start position:0% +also because when we get to zero we're +done if one of the numbers is zero we're + + align:start position:0% +done if one of the numbers is zero we're + + + align:start position:0% +done if one of the numbers is zero we're +happy so let's assume they're both at + + align:start position:0% +happy so let's assume they're both at + + + align:start position:0% +happy so let's assume they're both at +least one and let's assume by symmetry + + align:start position:0% +least one and let's assume by symmetry + + + align:start position:0% +least one and let's assume by symmetry +that a the one on the left is bigger or + + align:start position:0% +that a the one on the left is bigger or + + + align:start position:0% +that a the one on the left is bigger or +equal uh then I claim gcd of a is gcd of + + align:start position:0% +equal uh then I claim gcd of a is gcd of + + + align:start position:0% +equal uh then I claim gcd of a is gcd of +a remainder B comma + + align:start position:0% + + + + align:start position:0% + +B okay uh so before we had a minus B and + + align:start position:0% +B okay uh so before we had a minus B and + + + align:start position:0% +B okay uh so before we had a minus B and +now we have a remainder B seems like a + + align:start position:0% +now we have a remainder B seems like a + + + align:start position:0% +now we have a remainder B seems like a +small difference and indeed the proof is + + align:start position:0% +small difference and indeed the proof is + + + align:start position:0% +small difference and indeed the proof is +basically the same + + align:start position:0% +basically the same + + + align:start position:0% +basically the same +um I'm going to do a proof sketch which + + align:start position:0% +um I'm going to do a proof sketch which + + + align:start position:0% +um I'm going to do a proof sketch which +is to say well gcd of a comma B is equal + + align:start position:0% +is to say well gcd of a comma B is equal + + + align:start position:0% +is to say well gcd of a comma B is equal +to gcd of a minus B comma B uh and if we + + align:start position:0% +to gcd of a minus B comma B uh and if we + + + align:start position:0% +to gcd of a minus B comma B uh and if we +apply by the subtraction theorem uh + + align:start position:0% +apply by the subtraction theorem uh + + + align:start position:0% +apply by the subtraction theorem uh +which we just did over over there um and + + align:start position:0% +which we just did over over there um and + + + align:start position:0% +which we just did over over there um and +if we apply the subtraction theorem + + align:start position:0% +if we apply the subtraction theorem + + + align:start position:0% +if we apply the subtraction theorem +again we can subtract the right argument + + align:start position:0% +again we can subtract the right argument + + + align:start position:0% +again we can subtract the right argument +from the left one again A minus 2 B + + align:start position:0% +from the left one again A minus 2 B + + + align:start position:0% +from the left one again A minus 2 B +comma B and so on eventually we get to + + align:start position:0% +comma B and so on eventually we get to + + + align:start position:0% +comma B and so on eventually we get to +to gcd of a minus um a div B * + + align:start position:0% + + + + align:start position:0% + +B right a div B is how many whole copies + + align:start position:0% +B right a div B is how many whole copies + + + align:start position:0% +B right a div B is how many whole copies +of B I can fit into a and so if I take + + align:start position:0% +of B I can fit into a and so if I take + + + align:start position:0% +of B I can fit into a and so if I take +that number multiply it by B that's how + + align:start position:0% +that number multiply it by B that's how + + + align:start position:0% +that number multiply it by B that's how +much uh I can subtract away before a + + align:start position:0% +much uh I can subtract away before a + + + align:start position:0% +much uh I can subtract away before a +would go negative if I subtracted one + + align:start position:0% +would go negative if I subtracted one + + + align:start position:0% +would go negative if I subtracted one +more time and what I'll be left with is + + align:start position:0% +more time and what I'll be left with is + + + align:start position:0% +more time and what I'll be left with is +exactly the remainder a minus uh a remb + + align:start position:0% + + + + align:start position:0% + +times uh oh no times comma B If I + + align:start position:0% +times uh oh no times comma B If I + + + align:start position:0% +times uh oh no times comma B If I +subtract off that many copies of B I + + align:start position:0% +subtract off that many copies of B I + + + align:start position:0% +subtract off that many copies of B I +will be left with uh a remainder B sorry + + align:start position:0% +will be left with uh a remainder B sorry + + + align:start position:0% +will be left with uh a remainder B sorry +no a + + align:start position:0% + + + + align:start position:0% + +minus okay that's + + align:start position:0% +minus okay that's + + + align:start position:0% +minus okay that's +uh that's what we're writing here in + + align:start position:0% +uh that's what we're writing here in + + + align:start position:0% +uh that's what we're writing here in +fact so we wrote uh let me rewrite this + + align:start position:0% +fact so we wrote uh let me rewrite this + + + align:start position:0% +fact so we wrote uh let me rewrite this +um we have n or maybe I'll write it as + + align:start position:0% +um we have n or maybe I'll write it as + + + align:start position:0% +um we have n or maybe I'll write it as +uh Want A or + + align:start position:0% +uh Want A or + + + align:start position:0% +uh Want A or +B I'll stick with that what this over + + align:start position:0% +B I'll stick with that what this over + + + align:start position:0% +B I'll stick with that what this over +here is saying is uh n div D * D plus n + + align:start position:0% +here is saying is uh n div D * D plus n + + + align:start position:0% +here is saying is uh n div D * D plus n +RM D equals to n okay I'm just rewriting + + align:start position:0% +RM D equals to n okay I'm just rewriting + + + align:start position:0% +RM D equals to n okay I'm just rewriting +this formula using the notations for Q + + align:start position:0% +this formula using the notations for Q + + + align:start position:0% +this formula using the notations for Q +and R and if I rearrange this I get that + + align:start position:0% +and R and if I rearrange this I get that + + + align:start position:0% +and R and if I rearrange this I get that +n minus n divd + + align:start position:0% +n minus n divd + + + align:start position:0% +n minus n divd +* D equals + + align:start position:0% +* D equals + + + align:start position:0% +* D equals +ND okay and that's exactly what I'm + + align:start position:0% +ND okay and that's exactly what I'm + + + align:start position:0% +ND okay and that's exactly what I'm +using here the remainder is what you get + + align:start position:0% +using here the remainder is what you get + + + align:start position:0% +using here the remainder is what you get +what's left over if you take uh the + + align:start position:0% +what's left over if you take uh the + + + align:start position:0% +what's left over if you take uh the +numerator and subtract off uh the div + + align:start position:0% +numerator and subtract off uh the div + + + align:start position:0% +numerator and subtract off uh the div +many copies of the denominator so I use + + align:start position:0% +many copies of the denominator so I use + + + align:start position:0% +many copies of the denominator so I use +dot dot dot here you can't really use + + align:start position:0% +dot dot dot here you can't really use + + + align:start position:0% +dot dot dot here you can't really use +dot dot dot in a proof technically this + + align:start position:0% +dot dot dot in a proof technically this + + + align:start position:0% +dot dot dot in a proof technically this +is a proof by induction but I think + + align:start position:0% +is a proof by induction but I think + + + align:start position:0% +is a proof by induction but I think +hopefully you're familiar enough with + + align:start position:0% +hopefully you're familiar enough with + + + align:start position:0% +hopefully you're familiar enough with +induction that you could turn this into + + align:start position:0% +induction that you could turn this into + + + align:start position:0% +induction that you could turn this into +a formal proof it's not hard + + align:start position:0% + + + + align:start position:0% + +okay so we can + + align:start position:0% +okay so we can + + + align:start position:0% +okay so we can +divide and uh this will make this gcd + + align:start position:0% +divide and uh this will make this gcd + + + align:start position:0% +divide and uh this will make this gcd +algorithm much faster because now if I + + align:start position:0% +algorithm much faster because now if I + + + align:start position:0% +algorithm much faster because now if I +want to uh say to compute gcd of 1 comma + + align:start position:0% +want to uh say to compute gcd of 1 comma + + + align:start position:0% +want to uh say to compute gcd of 1 comma +100 this is the same thing as gcd of 100 + + align:start position:0% +100 this is the same thing as gcd of 100 + + + align:start position:0% +100 this is the same thing as gcd of 100 +comma + + align:start position:0% +comma + + + align:start position:0% +comma +1 and what that says is I can divide 100 + + align:start position:0% +1 and what that says is I can divide 100 + + + align:start position:0% +1 and what that says is I can divide 100 +by + + align:start position:0% +by + + + align:start position:0% +by +one and see what the remainder is well + + align:start position:0% +one and see what the remainder is well + + + align:start position:0% +one and see what the remainder is well +one divides 100 so the remainder is zero + + align:start position:0% +one divides 100 so the remainder is zero + + + align:start position:0% +one divides 100 so the remainder is zero +so I instantly get that this is gcd of 0 + + align:start position:0% +so I instantly get that this is gcd of 0 + + + align:start position:0% +so I instantly get that this is gcd of 0 +comma 1 + + align:start position:0% +comma 1 + + + align:start position:0% +comma 1 +boom uh I'm done this gcd of Zer comma + + align:start position:0% +boom uh I'm done this gcd of Zer comma + + + align:start position:0% +boom uh I'm done this gcd of Zer comma +anything is the + + align:start position:0% +anything is the + + + align:start position:0% +anything is the +anything so in like one step now one + + align:start position:0% +anything so in like one step now one + + + align:start position:0% +anything so in like one step now one +division instead of having to do a bunch + + align:start position:0% +division instead of having to do a bunch + + + align:start position:0% +division instead of having to do a bunch +of subtractions I compute the + + align:start position:0% +of subtractions I compute the + + + align:start position:0% +of subtractions I compute the +gcd great let's write this down as an + + align:start position:0% +gcd great let's write this down as an + + + align:start position:0% +gcd great let's write this down as an +algorithm + + align:start position:0% + + + + align:start position:0% + +this is called ukis algorithm or the + + align:start position:0% +this is called ukis algorithm or the + + + align:start position:0% +this is called ukis algorithm or the +ukian + + align:start position:0% + + + + align:start position:0% + +algorithm it's called UK's algorithm + + align:start position:0% +algorithm it's called UK's algorithm + + + align:start position:0% +algorithm it's called UK's algorithm +because uclid was not the first to + + align:start position:0% +because uclid was not the first to + + + align:start position:0% +because uclid was not the first to +discover it of course uh but he was + + align:start position:0% +discover it of course uh but he was + + + align:start position:0% +discover it of course uh but he was +still pretty early uh around 300C C uh + + align:start position:0% +still pretty early uh around 300C C uh + + + align:start position:0% +still pretty early uh around 300C C uh +but I'll mention an earlier version in + + align:start position:0% +but I'll mention an earlier version in + + + align:start position:0% +but I'll mention an earlier version in +in a moment uh so what this does is it + + align:start position:0% + + + + align:start position:0% + +computes gcd of + + align:start position:0% + + + + align:start position:0% + +ab uh + + align:start position:0% +ab uh + + + align:start position:0% +ab uh +for a greater than or equal to B greater + + align:start position:0% +for a greater than or equal to B greater + + + align:start position:0% +for a greater than or equal to B greater +than or equal to zero okay I'm going to + + align:start position:0% +than or equal to zero okay I'm going to + + + align:start position:0% +than or equal to zero okay I'm going to +assume everything's not negative if it's + + align:start position:0% +assume everything's not negative if it's + + + align:start position:0% +assume everything's not negative if it's +negative just negate it I'm going to + + align:start position:0% +negative just negate it I'm going to + + + align:start position:0% +negative just negate it I'm going to +assume the left argument is is bigger + + align:start position:0% +assume the left argument is is bigger + + + align:start position:0% +assume the left argument is is bigger +than the right one or equal uh if it's + + align:start position:0% +than the right one or equal uh if it's + + + align:start position:0% +than the right one or equal uh if it's +the other way around swap A and B okay + + align:start position:0% +the other way around swap A and B okay + + + align:start position:0% +the other way around swap A and B okay +so this is enough for computing gcd of + + align:start position:0% +so this is enough for computing gcd of + + + align:start position:0% +so this is enough for computing gcd of +any two + + align:start position:0% +any two + + + align:start position:0% +any two +integers um and I'm going to write this + + align:start position:0% +integers um and I'm going to write this + + + align:start position:0% +integers um and I'm going to write this +of course as a state + + align:start position:0% +of course as a state + + + align:start position:0% +of course as a state +machine so in general I'm going to have + + align:start position:0% +machine so in general I'm going to have + + + align:start position:0% +machine so in general I'm going to have +a pair of integers A and B where a is + + align:start position:0% +a pair of integers A and B where a is + + + align:start position:0% +a pair of integers A and B where a is +greater than equal to B uh greater equal + + align:start position:0% +greater than equal to B uh greater equal + + + align:start position:0% +greater than equal to B uh greater equal +to + + align:start position:0% +to + + + align:start position:0% +to +zero uh so I guess I should say the + + align:start position:0% +zero uh so I guess I should say the + + + align:start position:0% +zero uh so I guess I should say the +states are X comma y uh + + align:start position:0% +states are X comma y uh + + + align:start position:0% +states are X comma y uh +where X is greater equal to Y is greater + + align:start position:0% +where X is greater equal to Y is greater + + + align:start position:0% +where X is greater equal to Y is greater +than equal to zero and then the + + align:start position:0% + + + + align:start position:0% + +transitions go from X comma y to X REM + + align:start position:0% +transitions go from X comma y to X REM + + + align:start position:0% +transitions go from X comma y to X REM +y Oh wrong + + align:start position:0% + + + + align:start position:0% + +order y comma X Ram + + align:start position:0% +order y comma X Ram + + + align:start position:0% +order y comma X Ram +y okay almost the same as this theorem + + align:start position:0% +y okay almost the same as this theorem + + + align:start position:0% +y okay almost the same as this theorem +except I'm going to rewrite this as gcd + + align:start position:0% +except I'm going to rewrite this as gcd + + + align:start position:0% +except I'm going to rewrite this as gcd +of B comma a rem B just flip the + + align:start position:0% +of B comma a rem B just flip the + + + align:start position:0% +of B comma a rem B just flip the +arguments because I would like the left + + align:start position:0% +arguments because I would like the left + + + align:start position:0% +arguments because I would like the left +argument to always be greater than or + + align:start position:0% +argument to always be greater than or + + + align:start position:0% +argument to always be greater than or +equal to I would like the left argument + + align:start position:0% +equal to I would like the left argument + + + align:start position:0% +equal to I would like the left argument +to be always greater than or equal to + + align:start position:0% +to be always greater than or equal to + + + align:start position:0% +to be always greater than or equal to +the right argument um and if I do them + + align:start position:0% +the right argument um and if I do them + + + align:start position:0% +the right argument um and if I do them +in this order if x was greater than + + align:start position:0% +in this order if x was greater than + + + align:start position:0% +in this order if x was greater than +equal to Y I do this division this + + align:start position:0% +equal to Y I do this division this + + + align:start position:0% +equal to Y I do this division this +division will of course be less than y + + align:start position:0% +division will of course be less than y + + + align:start position:0% +division will of course be less than y +and so the left one will be bigger than + + align:start position:0% +and so the left one will be bigger than + + + align:start position:0% +and so the left one will be bigger than +the right one actually + + align:start position:0% +the right one actually + + + align:start position:0% +the right one actually +strictly in that case + + align:start position:0% +strictly in that case + + + align:start position:0% +strictly in that case +okay uh so that's basically just + + align:start position:0% +okay uh so that's basically just + + + align:start position:0% +okay uh so that's basically just +following this rule + + align:start position:0% +following this rule + + + align:start position:0% +following this rule +repeatedly and those are my + + align:start position:0% +repeatedly and those are my + + + align:start position:0% +repeatedly and those are my +transitions uh now this only + + align:start position:0% +transitions uh now this only + + + align:start position:0% +transitions uh now this only +works uh when Y is bigger than + + align:start position:0% +works uh when Y is bigger than + + + align:start position:0% +works uh when Y is bigger than +zero if Y is + + align:start position:0% +zero if Y is + + + align:start position:0% +zero if Y is +zero uh at um X comma 0 we + + align:start position:0% +zero uh at um X comma 0 we + + + align:start position:0% +zero uh at um X comma 0 we +return + + align:start position:0% +return + + + align:start position:0% +return +X as the + + align:start position:0% +X as the + + + align:start position:0% +X as the +gcd that's the final state or there + + align:start position:0% +gcd that's the final state or there + + + align:start position:0% +gcd that's the final state or there +these these are various final States any + + align:start position:0% +these these are various final States any + + + align:start position:0% +these these are various final States any +X comma 0 is going to be a final State + + align:start position:0% +X comma 0 is going to be a final State + + + align:start position:0% +X comma 0 is going to be a final State +there's no transition out of there + + align:start position:0% +there's no transition out of there + + + align:start position:0% +there's no transition out of there +because we're not allowed to divide by + + align:start position:0% +because we're not allowed to divide by + + + align:start position:0% +because we're not allowed to divide by +zero because I wrote this for all y + + align:start position:0% +zero because I wrote this for all y + + + align:start position:0% +zero because I wrote this for all y +greater than zero rule but at that in + + align:start position:0% +greater than zero rule but at that in + + + align:start position:0% +greater than zero rule but at that in +that situation we know the gcd of 0 + + align:start position:0% +that situation we know the gcd of 0 + + + align:start position:0% +that situation we know the gcd of 0 +comma b or B comma 0 is the absolute + + align:start position:0% +comma b or B comma 0 is the absolute + + + align:start position:0% +comma b or B comma 0 is the absolute +value of B because everything here is + + align:start position:0% +value of B because everything here is + + + align:start position:0% +value of B because everything here is +non- negative uh the answer is X at that + + align:start position:0% +non- negative uh the answer is X at that + + + align:start position:0% +non- negative uh the answer is X at that +point so why does this + + align:start position:0% +point so why does this + + + align:start position:0% +point so why does this +work well because we just proved an + + align:start position:0% +work well because we just proved an + + + align:start position:0% +work well because we just proved an +invariant that uh as this machine + + align:start position:0% +invariant that uh as this machine + + + align:start position:0% +invariant that uh as this machine +runs um I want to say p of + + align:start position:0% +runs um I want to say p of + + + align:start position:0% +runs um I want to say p of +XY is the state predicate which is uh + + align:start position:0% +XY is the state predicate which is uh + + + align:start position:0% +XY is the state predicate which is uh +the + + align:start position:0% +the + + + align:start position:0% +the +gcd of X comma y equals the gcd of a + + align:start position:0% +gcd of X comma y equals the gcd of a + + + align:start position:0% +gcd of X comma y equals the gcd of a +comma + + align:start position:0% +comma + + + align:start position:0% +comma +B right whatever we designed the change + + align:start position:0% +B right whatever we designed the change + + + align:start position:0% +B right whatever we designed the change +in arguments here we started with a + + align:start position:0% +in arguments here we started with a + + + align:start position:0% +in arguments here we started with a +comma B so this is true initially in our + + align:start position:0% +comma B so this is true initially in our + + + align:start position:0% +comma B so this is true initially in our +initial State a comma B of course gcd of + + align:start position:0% +initial State a comma B of course gcd of + + + align:start position:0% +initial State a comma B of course gcd of +a comma b equals gcd of a comma B and + + align:start position:0% +a comma b equals gcd of a comma B and + + + align:start position:0% +a comma b equals gcd of a comma B and +then every time we do a transition and + + align:start position:0% +then every time we do a transition and + + + align:start position:0% +then every time we do a transition and +we do this Division and take the + + align:start position:0% +we do this Division and take the + + + align:start position:0% +we do this Division and take the +remainder we still have we know that the + + align:start position:0% +remainder we still have we know that the + + + align:start position:0% +remainder we still have we know that the +gcds are equal by this + + align:start position:0% +gcds are equal by this + + + align:start position:0% +gcds are equal by this +theorem right that's exactly what this + + align:start position:0% +theorem right that's exactly what this + + + align:start position:0% +theorem right that's exactly what this +tells us and so this is saying this + + align:start position:0% +tells us and so this is saying this + + + align:start position:0% +tells us and so this is saying this +theorem tells us that this state + + align:start position:0% +theorem tells us that this state + + + align:start position:0% +theorem tells us that this state +predicate is preserved and because it + + align:start position:0% +predicate is preserved and because it + + + align:start position:0% +predicate is preserved and because it +holds initially that means it's + + align:start position:0% +holds initially that means it's + + + align:start position:0% +holds initially that means it's +invariant okay uh true initially + + align:start position:0% + + + + align:start position:0% + +uh and it's + + align:start position:0% + + + + align:start position:0% + +preserved by this theorem and so by the + + align:start position:0% +preserved by this theorem and so by the + + + align:start position:0% +preserved by this theorem and so by the +invariant principle we know that this + + align:start position:0% +invariant principle we know that this + + + align:start position:0% +invariant principle we know that this +will remain true for any reachable state + + align:start position:0% +will remain true for any reachable state + + + align:start position:0% +will remain true for any reachable state +XY we'll have gcd of XY equal gcd of ab + + align:start position:0% +XY we'll have gcd of XY equal gcd of ab + + + align:start position:0% +XY we'll have gcd of XY equal gcd of ab +and + + align:start position:0% +and + + + align:start position:0% +and +furthermore uh when we get to a final + + align:start position:0% +furthermore uh when we get to a final + + + align:start position:0% +furthermore uh when we get to a final +state so this is a final + + align:start position:0% + + + + align:start position:0% + +State uh we know that this answer is + + align:start position:0% +State uh we know that this answer is + + + align:start position:0% +State uh we know that this answer is +correct because gcd of X comma 0 equals + + align:start position:0% +correct because gcd of X comma 0 equals + + + align:start position:0% +correct because gcd of X comma 0 equals +X for non- Negative X so this was this + + align:start position:0% +X for non- Negative X so this was this + + + align:start position:0% +X for non- Negative X so this was this +is partial + + align:start position:0% +is partial + + + align:start position:0% +is partial +correctness if we get to a final + + align:start position:0% + + + + align:start position:0% + +State uh + + align:start position:0% +State uh + + + align:start position:0% +State uh +gcd of X comma 0 equals + + align:start position:0% +gcd of X comma 0 equals + + + align:start position:0% +gcd of X comma 0 equals +X for X greater than equal to Z by this + + align:start position:0% +X for X greater than equal to Z by this + + + align:start position:0% +X for X greater than equal to Z by this +theorem that we + + align:start position:0% +theorem that we + + + align:start position:0% +theorem that we +proved Okay so if this machine + + align:start position:0% +proved Okay so if this machine + + + align:start position:0% +proved Okay so if this machine +terminates we're + + align:start position:0% +terminates we're + + + align:start position:0% +terminates we're +done and I claim this machine does + + align:start position:0% +done and I claim this machine does + + + align:start position:0% +done and I claim this machine does +terminate so let's prove + + align:start position:0% +terminate so let's prove + + + align:start position:0% +terminate so let's prove +termination in a couple of + + align:start position:0% + + + + align:start position:0% + +ways so how do we prove termination of + + align:start position:0% +ways so how do we prove termination of + + + align:start position:0% +ways so how do we prove termination of +State machines we + + align:start position:0% +State machines we + + + align:start position:0% +State machines we +Define uh some value some function of + + align:start position:0% +Define uh some value some function of + + + align:start position:0% +Define uh some value some function of +States that's an integer a non- negative + + align:start position:0% +States that's an integer a non- negative + + + align:start position:0% +States that's an integer a non- negative +integer and we show that it strictly + + align:start position:0% +integer and we show that it strictly + + + align:start position:0% +integer and we show that it strictly +decreases that's our main tool for + + align:start position:0% +decreases that's our main tool for + + + align:start position:0% +decreases that's our main tool for +proving termination of algorithms uh so + + align:start position:0% +proving termination of algorithms uh so + + + align:start position:0% +proving termination of algorithms uh so +for example we could uh take the + + align:start position:0% +for example we could uh take the + + + align:start position:0% +for example we could uh take the +function X+ + + align:start position:0% +function X+ + + + align:start position:0% +function X+ +y this strictly + + align:start position:0% + + + + align:start position:0% + +decreases why uh just think about a + + align:start position:0% +decreases why uh just think about a + + + align:start position:0% +decreases why uh just think about a +transition we start with X comma y y + + align:start position:0% +transition we start with X comma y y + + + align:start position:0% +transition we start with X comma y y +doesn't change and then the other term + + align:start position:0% +doesn't change and then the other term + + + align:start position:0% +doesn't change and then the other term +in the sum used to be X and then it + + align:start position:0% +in the sum used to be X and then it + + + align:start position:0% +in the sum used to be X and then it +becomes X remainder y so we're dividing + + align:start position:0% +becomes X remainder y so we're dividing + + + align:start position:0% +becomes X remainder y so we're dividing +X by y so X gets smaller in that process + + align:start position:0% +X by y so X gets smaller in that process + + + align:start position:0% +X by y so X gets smaller in that process +and so the sum of these two values is + + align:start position:0% +and so the sum of these two values is + + + align:start position:0% +and so the sum of these two values is +going to be smaller than the sum of X + + align:start position:0% +going to be smaller than the sum of X + + + align:start position:0% +going to be smaller than the sum of X +and Y so that's cool we now know that + + align:start position:0% +and Y so that's cool we now know that + + + align:start position:0% +and Y so that's cool we now know that +this algorithm terminates um but stating + + align:start position:0% +this algorithm terminates um but stating + + + align:start position:0% +this algorithm terminates um but stating +it using this + + align:start position:0% +it using this + + + align:start position:0% +it using this +uh function is not so great because it + + align:start position:0% +uh function is not so great because it + + + align:start position:0% +uh function is not so great because it +tells us that the number of + + align:start position:0% +tells us that the number of + + + align:start position:0% +tells us that the number of +steps uh is uh at most a plus b + + align:start position:0% +steps uh is uh at most a plus b + + + align:start position:0% +steps uh is uh at most a plus b +but that's not great that's that's what + + align:start position:0% +but that's not great that's that's what + + + align:start position:0% +but that's not great that's that's what +we had before uh from our slow algorithm + + align:start position:0% +we had before uh from our slow algorithm + + + align:start position:0% +we had before uh from our slow algorithm +we got a running time of a plus b like + + align:start position:0% +we got a running time of a plus b like + + + align:start position:0% +we got a running time of a plus b like +so that's still true it's an upper bound + + align:start position:0% +so that's still true it's an upper bound + + + align:start position:0% +so that's still true it's an upper bound +on the running time but I claim that in + + align:start position:0% +on the running time but I claim that in + + + align:start position:0% +on the running time but I claim that in +fact our running time is much + + align:start position:0% +fact our running time is much + + + align:start position:0% +fact our running time is much +smaller by a more clever proof let me + + align:start position:0% +smaller by a more clever proof let me + + + align:start position:0% +smaller by a more clever proof let me +erase subtraction + + align:start position:0% + + + + align:start position:0% + +okay so I + + align:start position:0% +okay so I + + + align:start position:0% +okay so I +claim uh in + + align:start position:0% + + + + align:start position:0% + +fact if we look at the bit count of X + + align:start position:0% +fact if we look at the bit count of X + + + align:start position:0% +fact if we look at the bit count of X +and the bit count of Y in summation this + + align:start position:0% +and the bit count of Y in summation this + + + align:start position:0% +and the bit count of Y in summation this +also strictly decreases + + align:start position:0% + + + + align:start position:0% + +what is a bit count this is if you write + + align:start position:0% +what is a bit count this is if you write + + + align:start position:0% +what is a bit count this is if you write +X in binary how many bits are there + + align:start position:0% +X in binary how many bits are there + + + align:start position:0% +X in binary how many bits are there +what's the length of the binary + + align:start position:0% +what's the length of the binary + + + align:start position:0% +what's the length of the binary +representation of X um this is + + align:start position:0% +representation of X um this is + + + align:start position:0% +representation of X um this is +essentially 1 + log base 2 of X + + align:start position:0% +essentially 1 + log base 2 of X + + + align:start position:0% +essentially 1 + log base 2 of X +ceiling a little gross but uh ASM + + align:start position:0% +ceiling a little gross but uh ASM + + + align:start position:0% +ceiling a little gross but uh ASM +totically this is log base 2 of + + align:start position:0% +totically this is log base 2 of + + + align:start position:0% +totically this is log base 2 of +x or when you use ASM totic notation you + + align:start position:0% +x or when you use ASM totic notation you + + + align:start position:0% +x or when you use ASM totic notation you +don't even need the base because it only + + align:start position:0% +don't even need the base because it only + + + align:start position:0% +don't even need the base because it only +makes uh constant Factor difference so + + align:start position:0% +makes uh constant Factor difference so + + + align:start position:0% +makes uh constant Factor difference so +this is roughly log of x it's Theta log + + align:start position:0% +this is roughly log of x it's Theta log + + + align:start position:0% +this is roughly log of x it's Theta log +of x this is Theta log of Y so uh the + + align:start position:0% +of x this is Theta log of Y so uh the + + + align:start position:0% +of x this is Theta log of Y so uh the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +steps is order log X Plus log + + align:start position:0% +steps is order log X Plus log + + + align:start position:0% +steps is order log X Plus log +Y and that's really good that's + + align:start position:0% +Y and that's really good that's + + + align:start position:0% +Y and that's really good that's +exponentially faster sorry I should have + + align:start position:0% +exponentially faster sorry I should have + + + align:start position:0% +exponentially faster sorry I should have +written uh log a plus log B because + + align:start position:0% +written uh log a plus log B because + + + align:start position:0% +written uh log a plus log B because +that's where we start is a a comma B so + + align:start position:0% +that's where we start is a a comma B so + + + align:start position:0% +that's where we start is a a comma B so +if I give you two numbers A and B I can + + align:start position:0% +if I give you two numbers A and B I can + + + align:start position:0% +if I give you two numbers A and B I can +compute the gcd in roughly + + align:start position:0% +compute the gcd in roughly + + + align:start position:0% +compute the gcd in roughly +logarithmically many divisions whereas + + align:start position:0% +logarithmically many divisions whereas + + + align:start position:0% +logarithmically many divisions whereas +before we did a plus b now we have log a + + align:start position:0% +before we did a plus b now we have log a + + + align:start position:0% +before we did a plus b now we have log a +plus log B so that's what we call an + + align:start position:0% +plus log B so that's what we call an + + + align:start position:0% +plus log B so that's what we call an +exponential Improvement and this is a + + align:start position:0% +exponential Improvement and this is a + + + align:start position:0% +exponential Improvement and this is a +what we would call a fast algorithm + + align:start position:0% +what we would call a fast algorithm + + + align:start position:0% +what we would call a fast algorithm +because now if I have a 100 bit integer + + align:start position:0% +because now if I have a 100 bit integer + + + align:start position:0% +because now if I have a 100 bit integer +it only takes me like or or two 100 bit + + align:start position:0% +it only takes me like or or two 100 bit + + + align:start position:0% +it only takes me like or or two 100 bit +integers it only takes me around 100 + + align:start position:0% +integers it only takes me around 100 + + + align:start position:0% +integers it only takes me around 100 +steps whereas before is taking me two to + + align:start position:0% +steps whereas before is taking me two to + + + align:start position:0% +steps whereas before is taking me two to +the 100 steps big difference + + align:start position:0% +the 100 steps big difference + + + align:start position:0% +the 100 steps big difference +okay uh why is this true why is bit + + align:start position:0% +okay uh why is this true why is bit + + + align:start position:0% +okay uh why is this true why is bit +count of X Plus bit count of Y strictly + + align:start position:0% +count of X Plus bit count of Y strictly + + + align:start position:0% +count of X Plus bit count of Y strictly +decreasing um + + align:start position:0% +decreasing um + + + align:start position:0% +decreasing um +because I + + align:start position:0% +because I + + + align:start position:0% +because I +claim so I should say + + align:start position:0% +claim so I should say + + + align:start position:0% +claim so I should say +because XR Y is less than x over2 this + + align:start position:0% +because XR Y is less than x over2 this + + + align:start position:0% +because XR Y is less than x over2 this +is another fact about division um I + + align:start position:0% +is another fact about division um I + + + align:start position:0% +is another fact about division um I +think + + align:start position:0% +think + + + align:start position:0% +think +the intuition here is uh Y is smaller + + align:start position:0% +the intuition here is uh Y is smaller + + + align:start position:0% +the intuition here is uh Y is smaller +than x when we're doing this Division + + align:start position:0% +than x when we're doing this Division + + + align:start position:0% +than x when we're doing this Division +and so we can remove at least one whole + + align:start position:0% +and so we can remove at least one whole + + + align:start position:0% +and so we can remove at least one whole +copy of Y from X and maybe we remove + + align:start position:0% +copy of Y from X and maybe we remove + + + align:start position:0% +copy of Y from X and maybe we remove +more but um yeah you can think about + + align:start position:0% +more but um yeah you can think about + + + align:start position:0% +more but um yeah you can think about +when y if Y is more than half X then + + align:start position:0% +when y if Y is more than half X then + + + align:start position:0% +when y if Y is more than half X then +just in the first step we've removed + + align:start position:0% +just in the first step we've removed + + + align:start position:0% +just in the first step we've removed +half of X and so we've gotten down to + + align:start position:0% +half of X and so we've gotten down to + + + align:start position:0% +half of X and so we've gotten down to +less than x over two um if x is smaller + + align:start position:0% +less than x over two um if x is smaller + + + align:start position:0% +less than x over two um if x is smaller +if Y is really small like one then we're + + align:start position:0% +if Y is really small like one then we're + + + align:start position:0% +if Y is really small like one then we're +going to be able to eat all of x uh in + + align:start position:0% +going to be able to eat all of x uh in + + + align:start position:0% +going to be able to eat all of x uh in +both cases you'll end up uh eating at + + align:start position:0% +both cases you'll end up uh eating at + + + align:start position:0% +both cases you'll end up uh eating at +least half of X and so in general the + + align:start position:0% +least half of X and so in general the + + + align:start position:0% +least half of X and so in general the +remainder will be less than half of X + + align:start position:0% +remainder will be less than half of X + + + align:start position:0% +remainder will be less than half of X +over2 and so if we start with X and we + + align:start position:0% +over2 and so if we start with X and we + + + align:start position:0% +over2 and so if we start with X and we +in the next step we get to X over2 or + + align:start position:0% +in the next step we get to X over2 or + + + align:start position:0% +in the next step we get to X over2 or +smaller that means we removed one bit + + align:start position:0% +smaller that means we removed one bit + + + align:start position:0% +smaller that means we removed one bit +from the binary representation or if you + + align:start position:0% +from the binary representation or if you + + + align:start position:0% +from the binary representation or if you +think about it in log base 2 we've if we + + align:start position:0% +think about it in log base 2 we've if we + + + align:start position:0% +think about it in log base 2 we've if we +have the number log base two goes down + + align:start position:0% +have the number log base two goes down + + + align:start position:0% +have the number log base two goes down +by one so even with the ceiling it goes + + align:start position:0% +by one so even with the ceiling it goes + + + align:start position:0% +by one so even with the ceiling it goes +down by + + align:start position:0% +down by + + + align:start position:0% +down by +one okay so that's why this uclid + + align:start position:0% +one okay so that's why this uclid + + + align:start position:0% +one okay so that's why this uclid +algorithm is fast and good that's why we + + align:start position:0% +algorithm is fast and good that's why we + + + align:start position:0% +algorithm is fast and good that's why we +love it um I have for you a little of + + align:start position:0% +love it um I have for you a little of + + + align:start position:0% +love it um I have for you a little of +the algorithm and then we'll talk about + + align:start position:0% +the algorithm and then we'll talk about + + + align:start position:0% +the algorithm and then we'll talk about +extensions so here uh on the screen + + align:start position:0% +extensions so here uh on the screen + + + align:start position:0% +extensions so here uh on the screen +we're Computing gcd of 189 and + + align:start position:0% +we're Computing gcd of 189 and + + + align:start position:0% +we're Computing gcd of 189 and +66 if we think of that as a rectangle + + align:start position:0% +66 if we think of that as a rectangle + + + align:start position:0% +66 if we think of that as a rectangle +189 by + + align:start position:0% +189 by + + + align:start position:0% +189 by +606 uh then doing a division is like + + align:start position:0% +606 uh then doing a division is like + + + align:start position:0% +606 uh then doing a division is like +Square + + align:start position:0% +Square + + + align:start position:0% +Square +packing um so + + align:start position:0% +packing um so + + + align:start position:0% +packing um so +here if we have an A by B rectangle and + + align:start position:0% +here if we have an A by B rectangle and + + + align:start position:0% +here if we have an A by B rectangle and +a and b is the smaller one uh then a b + + align:start position:0% +a and b is the smaller one uh then a b + + + align:start position:0% +a and b is the smaller one uh then a b +by B squ like subtracting off B and so + + align:start position:0% +by B squ like subtracting off B and so + + + align:start position:0% +by B squ like subtracting off B and so +uh if you think of the whole rectangle + + align:start position:0% +uh if you think of the whole rectangle + + + align:start position:0% +uh if you think of the whole rectangle +it's how many squares can I subtract off + + align:start position:0% +it's how many squares can I subtract off + + + align:start position:0% +it's how many squares can I subtract off +and what we'll be left with is the + + align:start position:0% +and what we'll be left with is the + + + align:start position:0% +and what we'll be left with is the +remainder because one dimension stays + + align:start position:0% +remainder because one dimension stays + + + align:start position:0% +remainder because one dimension stays +the same the other dimension gets + + align:start position:0% +the same the other dimension gets + + + align:start position:0% +the same the other dimension gets +reduced to the remainder so hopefully + + align:start position:0% +reduced to the remainder so hopefully + + + align:start position:0% +reduced to the remainder so hopefully +that's clear why the geometric view of + + align:start position:0% +that's clear why the geometric view of + + + align:start position:0% +that's clear why the geometric view of +squares is the same as what we've been + + align:start position:0% +squares is the same as what we've been + + + align:start position:0% +squares is the same as what we've been +doing with UK's algorithm makes for a + + align:start position:0% +doing with UK's algorithm makes for a + + + align:start position:0% +doing with UK's algorithm makes for a +much nicer picture and then you take + + align:start position:0% +much nicer picture and then you take + + + align:start position:0% +much nicer picture and then you take +that rectangle and you flip it so that + + align:start position:0% +that rectangle and you flip it so that + + + align:start position:0% +that rectangle and you flip it so that +the horizontal Dimensions bigger you + + align:start position:0% +the horizontal Dimensions bigger you + + + align:start position:0% +the horizontal Dimensions bigger you +take off as many squares as you can and + + align:start position:0% +take off as many squares as you can and + + + align:start position:0% +take off as many squares as you can and +you flip and you take off as many + + align:start position:0% +you flip and you take off as many + + + align:start position:0% +you flip and you take off as many +squares as you can here's just just one + + align:start position:0% +squares as you can here's just just one + + + align:start position:0% +squares as you can here's just just one +that's just a subtraction you flip uh + + align:start position:0% +that's just a subtraction you flip uh + + + align:start position:0% +that's just a subtraction you flip uh +you take off as many squares as you can + + align:start position:0% +you take off as many squares as you can + + + align:start position:0% +you take off as many squares as you can +you left with a remainder of three by + + align:start position:0% +you left with a remainder of three by + + + align:start position:0% +you left with a remainder of three by +six uh and now here we get even Division + + align:start position:0% +six uh and now here we get even Division + + + align:start position:0% +six uh and now here we get even Division +and so one of the dimensions becomes + + align:start position:0% +and so one of the dimensions becomes + + + align:start position:0% +and so one of the dimensions becomes +zero and then the gcd of three and zero + + align:start position:0% +zero and then the gcd of three and zero + + + align:start position:0% +zero and then the gcd of three and zero +is uh + + align:start position:0% +is uh + + + align:start position:0% +is uh +three + + align:start position:0% +three + + + align:start position:0% +three +cool so if that helps great if not don't + + align:start position:0% +cool so if that helps great if not don't + + + align:start position:0% +cool so if that helps great if not don't +worry uh hopefully you can now compute + + align:start position:0% +worry uh hopefully you can now compute + + + align:start position:0% +worry uh hopefully you can now compute +gcd uh we will do another example in a + + align:start position:0% +gcd uh we will do another example in a + + + align:start position:0% +gcd uh we will do another example in a +second I would like to first uh + + align:start position:0% +second I would like to first uh + + + align:start position:0% +second I would like to first uh +strengthen this algorithm and make it uh + + align:start position:0% +strengthen this algorithm and make it uh + + + align:start position:0% +strengthen this algorithm and make it uh +do more + + align:start position:0% +do more + + + align:start position:0% +do more +because remember we wanted to compute + + align:start position:0% +because remember we wanted to compute + + + align:start position:0% +because remember we wanted to compute +gcd uh why we wanted to see whether gcd + + align:start position:0% +gcd uh why we wanted to see whether gcd + + + align:start position:0% +gcd uh why we wanted to see whether gcd +of ab divided X because if the gcd of ab + + align:start position:0% +of ab divided X because if the gcd of ab + + + align:start position:0% +of ab divided X because if the gcd of ab +divides X then all common divisors of A + + align:start position:0% +divides X then all common divisors of A + + + align:start position:0% +divides X then all common divisors of A +and B will divide x uh and what the + + align:start position:0% +and B will divide x uh and what the + + + align:start position:0% +and B will divide x uh and what the +reason we cared about that is I claimed + + align:start position:0% +reason we cared about that is I claimed + + + align:start position:0% +reason we cared about that is I claimed +it was the same thing as X being an + + align:start position:0% +it was the same thing as X being an + + + align:start position:0% +it was the same thing as X being an +integer linear combination of A and B + + align:start position:0% +integer linear combination of A and B + + + align:start position:0% +integer linear combination of A and B +but where did the integer linear + + align:start position:0% +but where did the integer linear + + + align:start position:0% +but where did the integer linear +combinations go all we've done so far is + + align:start position:0% +combinations go all we've done so far is + + + align:start position:0% +combinations go all we've done so far is +compute gcd of ab well it turns out + + align:start position:0% +compute gcd of ab well it turns out + + + align:start position:0% +compute gcd of ab well it turns out +there's a connection + + align:start position:0% +there's a connection + + + align:start position:0% +there's a connection +and the connection is called bezus + + align:start position:0% +and the connection is called bezus + + + align:start position:0% +and the connection is called bezus +theorem or + + align:start position:0% +theorem or + + + align:start position:0% +theorem or +LMA it's called bazus Lemma because B is + + align:start position:0% +LMA it's called bazus Lemma because B is + + + align:start position:0% +LMA it's called bazus Lemma because B is +like the last person to discover it + + align:start position:0% +like the last person to discover it + + + align:start position:0% +like the last person to discover it +after uh in + + align:start position:0% +after uh in + + + align:start position:0% +after uh in +1779 after another French mathematician + + align:start position:0% +1779 after another French mathematician + + + align:start position:0% +1779 after another French mathematician +mesak uh in 1624 and after uh two Indian + + align:start position:0% +mesak uh in 1624 and after uh two Indian + + + align:start position:0% +mesak uh in 1624 and after uh two Indian +mathematicians around 500 uh AC so uh + + align:start position:0% +mathematicians around 500 uh AC so uh + + + align:start position:0% +mathematicians around 500 uh AC so uh +but we call it Biz LMA + + align:start position:0% + + + + align:start position:0% + +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +connection uh gcd of ab is an integer + + align:start position:0% +connection uh gcd of ab is an integer + + + align:start position:0% +connection uh gcd of ab is an integer +linear combination of A and B and we can + + align:start position:0% +linear combination of A and B and we can + + + align:start position:0% +linear combination of A and B and we can +prove this using UK's + + align:start position:0% +prove this using UK's + + + align:start position:0% +prove this using UK's +algorithm is pretty + + align:start position:0% +algorithm is pretty + + + align:start position:0% +algorithm is pretty +cool we're going + + align:start position:0% +cool we're going + + + align:start position:0% +cool we're going +to uh buy ukids algorithm + + align:start position:0% + + + + align:start position:0% + +okay uh let me do this + + align:start position:0% +okay uh let me do this + + + align:start position:0% +okay uh let me do this +quickly let's assume a is greater equal + + align:start position:0% +quickly let's assume a is greater equal + + + align:start position:0% +quickly let's assume a is greater equal +to B again if not we can just swap A and + + align:start position:0% +to B again if not we can just swap A and + + + align:start position:0% +to B again if not we can just swap A and +B and I guess we'll assume greater equal + + align:start position:0% +B and I guess we'll assume greater equal + + + align:start position:0% +B and I guess we'll assume greater equal +to zero so we can apply ul's + + align:start position:0% +to zero so we can apply ul's + + + align:start position:0% +to zero so we can apply ul's +algorithm uh UK's algorithm tells us or + + align:start position:0% +algorithm uh UK's algorithm tells us or + + + align:start position:0% +algorithm uh UK's algorithm tells us or +the theorem we proved before UK's + + align:start position:0% +the theorem we proved before UK's + + + align:start position:0% +the theorem we proved before UK's +algorithm tells us gcd of ab equals gcd + + align:start position:0% +algorithm tells us gcd of ab equals gcd + + + align:start position:0% +algorithm tells us gcd of ab equals gcd +of B comma a rem B + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and we can use induction + + align:start position:0% + + + + align:start position:0% + +Now by strong + + align:start position:0% + + + + align:start position:0% + +induction on a plus b so this is very + + align:start position:0% +induction on a plus b so this is very + + + align:start position:0% +induction on a plus b so this is very +similar to what we were saying here uh X + + align:start position:0% +similar to what we were saying here uh X + + + align:start position:0% +similar to what we were saying here uh X +Plus y strictly decreases it's all we + + align:start position:0% +Plus y strictly decreases it's all we + + + align:start position:0% +Plus y strictly decreases it's all we +need for induction to work here so we're + + align:start position:0% +need for induction to work here so we're + + + align:start position:0% +need for induction to work here so we're +assuming by induction + + align:start position:0% +assuming by induction + + + align:start position:0% +assuming by induction +that if a plus b is smaller than the + + align:start position:0% +that if a plus b is smaller than the + + + align:start position:0% +that if a plus b is smaller than the +current value then gcd of AA B is an + + align:start position:0% +current value then gcd of AA B is an + + + align:start position:0% +current value then gcd of AA B is an +integ linear combination of A and B and + + align:start position:0% +integ linear combination of A and B and + + + align:start position:0% +integ linear combination of A and B and +so here we have gcd of A and B and we've + + align:start position:0% +so here we have gcd of A and B and we've + + + align:start position:0% +so here we have gcd of A and B and we've +reduced it to gcd of some smaller values + + align:start position:0% +reduced it to gcd of some smaller values + + + align:start position:0% +reduced it to gcd of some smaller values +or whose sum is smaller and so we can + + align:start position:0% +or whose sum is smaller and so we can + + + align:start position:0% +or whose sum is smaller and so we can +apply strong induction to the this + + align:start position:0% +apply strong induction to the this + + + align:start position:0% +apply strong induction to the this +pair uh and so we'll get that this gcd + + align:start position:0% +pair uh and so we'll get that this gcd + + + align:start position:0% +pair uh and so we'll get that this gcd +is an integer linear combination of its + + align:start position:0% +is an integer linear combination of its + + + align:start position:0% +is an integer linear combination of its +arguments so + + align:start position:0% +arguments so + + + align:start position:0% +arguments so +let's continue here + + align:start position:0% + + + + align:start position:0% + +so by strong induction we get that uh + + align:start position:0% +so by strong induction we get that uh + + + align:start position:0% +so by strong induction we get that uh +gcd of B comma a ram + + align:start position:0% +gcd of B comma a ram + + + align:start position:0% +gcd of B comma a ram +B uh is an integer linear + + align:start position:0% +B uh is an integer linear + + + align:start position:0% +B uh is an integer linear +combination of b and a rem + + align:start position:0% +combination of b and a rem + + + align:start position:0% +combination of b and a rem +B okay and this value of course is equal + + align:start position:0% +B okay and this value of course is equal + + + align:start position:0% +B okay and this value of course is equal +to gcd of + + align:start position:0% +to gcd of + + + align:start position:0% +to gcd of +ab by this equality and so uh we get + + align:start position:0% +ab by this equality and so uh we get + + + align:start position:0% +ab by this equality and so uh we get +that the gcd we care about is integer + + align:start position:0% +that the gcd we care about is integer + + + align:start position:0% +that the gcd we care about is integer +linear combination not of A and B but of + + align:start position:0% +linear combination not of A and B but of + + + align:start position:0% +linear combination not of A and B but of +this reduced version b and a rem B okay + + align:start position:0% +this reduced version b and a rem B okay + + + align:start position:0% +this reduced version b and a rem B okay +that's kind of annoying but it turns out + + align:start position:0% +that's kind of annoying but it turns out + + + align:start position:0% +that's kind of annoying but it turns out +uh a r + + align:start position:0% +uh a r + + + align:start position:0% +uh a r +b is an integer linear combination of A + + align:start position:0% +b is an integer linear combination of A + + + align:start position:0% +b is an integer linear combination of A +and + + align:start position:0% +and + + + align:start position:0% +and +B Why by the division + + align:start position:0% +B Why by the division + + + align:start position:0% +B Why by the division +theorem actually wrote it out over here + + align:start position:0% +theorem actually wrote it out over here + + + align:start position:0% +theorem actually wrote it out over here +we wrote that NR D is n minus something + + align:start position:0% +we wrote that NR D is n minus something + + + align:start position:0% +we wrote that NR D is n minus something +time D that is this thing is an integer + + align:start position:0% +time D that is this thing is an integer + + + align:start position:0% +time D that is this thing is an integer +linear combination of N and + + align:start position:0% +linear combination of N and + + + align:start position:0% +linear combination of N and +d and so if I'm if I'm doing a rem B I + + align:start position:0% +d and so if I'm if I'm doing a rem B I + + + align:start position:0% +d and so if I'm if I'm doing a rem B I +get that it's a + + align:start position:0% +get that it's a + + + align:start position:0% +get that it's a +minus uh something the div times uh B so + + align:start position:0% +minus uh something the div times uh B so + + + align:start position:0% +minus uh something the div times uh B so +that's an integer linear combination of + + align:start position:0% +that's an integer linear combination of + + + align:start position:0% +that's an integer linear combination of +A and + + align:start position:0% +A and + + + align:start position:0% +A and +B okay so what we're left with is we + + align:start position:0% +B okay so what we're left with is we + + + align:start position:0% +B okay so what we're left with is we +have that this gcd that we care about is + + align:start position:0% +have that this gcd that we care about is + + + align:start position:0% +have that this gcd that we care about is +an integer linear combination of B and + + align:start position:0% +an integer linear combination of B and + + + align:start position:0% +an integer linear combination of B and +something else that is an integer linear + + align:start position:0% +something else that is an integer linear + + + align:start position:0% +something else that is an integer linear +combination of A and B so in other words + + align:start position:0% +combination of A and B so in other words + + + align:start position:0% +combination of A and B so in other words +we have an integer linear combination of + + align:start position:0% +we have an integer linear combination of + + + align:start position:0% +we have an integer linear combination of +two integer linear combinations of A and + + align:start position:0% +two integer linear combinations of A and + + + align:start position:0% +two integer linear combinations of A and +B Because B is definitely an integer + + align:start position:0% +B Because B is definitely an integer + + + align:start position:0% +B Because B is definitely an integer +linear combination of A and B it's 0 * a + + align:start position:0% +linear combination of A and B it's 0 * a + + + align:start position:0% +linear combination of A and B it's 0 * a +plus 1 time b a rem B is an integer + + align:start position:0% +plus 1 time b a rem B is an integer + + + align:start position:0% +plus 1 time b a rem B is an integer +linear combination as written over there + + align:start position:0% +linear combination as written over there + + + align:start position:0% +linear combination as written over there +and so now we're just taking an integer + + align:start position:0% +and so now we're just taking an integer + + + align:start position:0% +and so now we're just taking an integer +linear combination of those two things + + align:start position:0% +linear combination of those two things + + + align:start position:0% +linear combination of those two things +and that's also an integer linear + + align:start position:0% +and that's also an integer linear + + + align:start position:0% +and that's also an integer linear +combination + + align:start position:0% +combination + + + align:start position:0% +combination +of A and B as we showed + + align:start position:0% +of A and B as we showed + + + align:start position:0% +of A and B as we showed +before okay so that's maybe a little + + align:start position:0% +before okay so that's maybe a little + + + align:start position:0% +before okay so that's maybe a little +abstract but it does prove the theorem + + align:start position:0% +abstract but it does prove the theorem + + + align:start position:0% +abstract but it does prove the theorem +now I'm going to turn that into an + + align:start position:0% +now I'm going to turn that into an + + + align:start position:0% +now I'm going to turn that into an +algorithm cool + + align:start position:0% +algorithm cool + + + align:start position:0% +algorithm cool +algorithm uh maybe over + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +here which is called the pulverizer + + align:start position:0% + + + + align:start position:0% + +I mentioned ucl's algorithm was + + align:start position:0% +I mentioned ucl's algorithm was + + + align:start position:0% +I mentioned ucl's algorithm was +discovered before uid in fact a stronger + + align:start position:0% +discovered before uid in fact a stronger + + + align:start position:0% +discovered before uid in fact a stronger +version of ID's algorithm called the + + align:start position:0% +version of ID's algorithm called the + + + align:start position:0% +version of ID's algorithm called the +pulverizer was Des uh described by Arab + + align:start position:0% +pulverizer was Des uh described by Arab + + + align:start position:0% +pulverizer was Des uh described by Arab +Bata an Indian mathematician around 500 + + align:start position:0% +Bata an Indian mathematician around 500 + + + align:start position:0% +Bata an Indian mathematician around 500 +AC so uh long time ago and he called it + + align:start position:0% +AC so uh long time ago and he called it + + + align:start position:0% +AC so uh long time ago and he called it +kutaka which is sanskrit for + + align:start position:0% +kutaka which is sanskrit for + + + align:start position:0% +kutaka which is sanskrit for +pulverization so we're going to call + + align:start position:0% +pulverization so we're going to call + + + align:start position:0% +pulverization so we're going to call +this the pulverizer most people call + + align:start position:0% +this the pulverizer most people call + + + align:start position:0% +this the pulverizer most people call +this the extended ukian algorithm + + align:start position:0% + + + + align:start position:0% + +uh and it's basically run ID's algorithm + + align:start position:0% +uh and it's basically run ID's algorithm + + + align:start position:0% +uh and it's basically run ID's algorithm +but also keep in mind what's going on in + + align:start position:0% +but also keep in mind what's going on in + + + align:start position:0% +but also keep in mind what's going on in +beus LMA and always keep track of X and + + align:start position:0% +beus LMA and always keep track of X and + + + align:start position:0% +beus LMA and always keep track of X and +Y as an integer linear combination of A + + align:start position:0% +Y as an integer linear combination of A + + + align:start position:0% +Y as an integer linear combination of A +and B okay so that's the + + align:start position:0% +and B okay so that's the + + + align:start position:0% +and B okay so that's the +intuition uh as a state machine it's + + align:start position:0% +intuition uh as a state machine it's + + + align:start position:0% +intuition uh as a state machine it's +quite simple kind of simple + + align:start position:0% +quite simple kind of simple + + + align:start position:0% +quite simple kind of simple +A10 B 01 is where we start because a + + align:start position:0% +A10 B 01 is where we start because a + + + align:start position:0% +A10 B 01 is where we start because a +equal 1 * a + 0 * B and B = 0 * a + 1 * + + align:start position:0% +equal 1 * a + 0 * B and B = 0 * a + 1 * + + + align:start position:0% +equal 1 * a + 0 * B and B = 0 * a + 1 * +B so that's how we represent a and b as + + align:start position:0% +B so that's how we represent a and b as + + + align:start position:0% +B so that's how we represent a and b as +integer linear combinations of A and B + + align:start position:0% +integer linear combinations of A and B + + + align:start position:0% +integer linear combinations of A and B +pretty trivial and then our transitions + + align:start position:0% +pretty trivial and then our transitions + + + align:start position:0% +pretty trivial and then our transitions +if we have X + + align:start position:0% +if we have X + + + align:start position:0% +if we have X +St so this means u x = s * a + T * + + align:start position:0% +St so this means u x = s * a + T * + + + align:start position:0% +St so this means u x = s * a + T * +B and we have uh y u v so in other words + + align:start position:0% +B and we have uh y u v so in other words + + + align:start position:0% +B and we have uh y u v so in other words +we've represented y as U * s plus v * + + align:start position:0% +we've represented y as U * s plus v * + + + align:start position:0% +we've represented y as U * s plus v * +sorry uh V time U * a plus v * + + align:start position:0% +sorry uh V time U * a plus v * + + + align:start position:0% +sorry uh V time U * a plus v * +B then we transition + + align:start position:0% +B then we transition + + + align:start position:0% +B then we transition +to + + align:start position:0% + + + + align:start position:0% + +uh that's a mistake this should be y UV + + align:start position:0% +uh that's a mistake this should be y UV + + + align:start position:0% +uh that's a mistake this should be y UV +uh we we as usual we just copy y to the + + align:start position:0% +uh we we as usual we just copy y to the + + + align:start position:0% +uh we we as usual we just copy y to the +left argument we don't change it and + + align:start position:0% +left argument we don't change it and + + + align:start position:0% +left argument we don't change it and +then X changes to um x r + + align:start position:0% +then X changes to um x r + + + align:start position:0% +then X changes to um x r +y and then it turns out you can + + align:start position:0% +y and then it turns out you can + + + align:start position:0% +y and then it turns out you can +write uh you can figure out how XR Y is + + align:start position:0% +write uh you can figure out how XR Y is + + + align:start position:0% +write uh you can figure out how XR Y is +relative to the as a linear combination + + align:start position:0% +relative to the as a linear combination + + + align:start position:0% +relative to the as a linear combination +of A and B like + + align:start position:0% + + + + align:start position:0% + +this it's kind of a little + + align:start position:0% + + + + align:start position:0% + +gross okay so we started with + + align:start position:0% +gross okay so we started with + + + align:start position:0% +gross okay so we started with +representing X as uh s * a plus T * B + + align:start position:0% +representing X as uh s * a plus T * B + + + align:start position:0% +representing X as uh s * a plus T * B +and we take s and we subtract off a + + align:start position:0% +and we take s and we subtract off a + + + align:start position:0% +and we take s and we subtract off a +corrective term which is XD y time + + align:start position:0% +corrective term which is XD y time + + + align:start position:0% +corrective term which is XD y time +either U or V where U or V is what + + align:start position:0% +either U or V where U or V is what + + + align:start position:0% +either U or V where U or V is what +represented y okay if you work it out + + align:start position:0% +represented y okay if you work it out + + + align:start position:0% +represented y okay if you work it out +that's exactly what we were doing here + + align:start position:0% +that's exactly what we were doing here + + + align:start position:0% +that's exactly what we were doing here +we started with one number and we uh + + align:start position:0% +we started with one number and we uh + + + align:start position:0% +we started with one number and we uh +subtracted off the div times what we had + + align:start position:0% +subtracted off the div times what we had + + + align:start position:0% +subtracted off the div times what we had +before so if you stare at it at this + + align:start position:0% +before so if you stare at it at this + + + align:start position:0% +before so if you stare at it at this +equation long enough uh this is exactly + + align:start position:0% +equation long enough uh this is exactly + + + align:start position:0% +equation long enough uh this is exactly +what we're doing but in uh integer + + align:start position:0% +what we're doing but in uh integer + + + align:start position:0% +what we're doing but in uh integer +linear combination space of A and B + + align:start position:0% +linear combination space of A and B + + + align:start position:0% +linear combination space of A and B +um so I'm not going to justify this + + align:start position:0% +um so I'm not going to justify this + + + align:start position:0% +um so I'm not going to justify this +anymore and I won't even show an example + + align:start position:0% +anymore and I won't even show an example + + + align:start position:0% +anymore and I won't even show an example +but it gives you this is a particular + + align:start position:0% +but it gives you this is a particular + + + align:start position:0% +but it gives you this is a particular +way to compute it um and I I'll say at + + align:start position:0% +way to compute it um and I I'll say at + + + align:start position:0% +way to compute it um and I I'll say at +the beginning of an example if you have + + align:start position:0% +the beginning of an example if you have + + + align:start position:0% +the beginning of an example if you have + + align:start position:0% + + + + align:start position:0% + +0301 and you run this a few times you + + align:start position:0% +0301 and you run this a few times you + + + align:start position:0% +0301 and you run this a few times you +get + + align:start position:0% +get + + + align:start position:0% +get +to + + align:start position:0% +to + + + align:start position:0% +to +um 2 1us + + align:start position:0% +um 2 1us + + + align:start position:0% +um 2 1us +1 1 -1 2 and this part tells us that 1 + + align:start position:0% +1 1 -1 2 and this part tells us that 1 + + + align:start position:0% +1 1 -1 2 and this part tells us that 1 +equals -1 * 5 + 2 * 3 I hope that is + + align:start position:0% +equals -1 * 5 + 2 * 3 I hope that is + + + align:start position:0% +equals -1 * 5 + 2 * 3 I hope that is +correct uh - 5 + 6 is 1 yep okay so this + + align:start position:0% +correct uh - 5 + 6 is 1 yep okay so this + + + align:start position:0% +correct uh - 5 + 6 is 1 yep okay so this +is how you represent one as an integer + + align:start position:0% +is how you represent one as an integer + + + align:start position:0% +is how you represent one as an integer +linear combination of five and three one + + align:start position:0% +linear combination of five and three one + + + align:start position:0% +linear combination of five and three one +is interesting because it's the gcd of + + align:start position:0% +is interesting because it's the gcd of + + + align:start position:0% +is interesting because it's the gcd of +five and three I'm this is connecting to + + align:start position:0% +five and three I'm this is connecting to + + + align:start position:0% +five and three I'm this is connecting to +the water pouring right with water + + align:start position:0% +the water pouring right with water + + + align:start position:0% +the water pouring right with water +pouring we had a container of size five + + align:start position:0% +pouring we had a container of size five + + + align:start position:0% +pouring we had a container of size five +container of size three their gcd is one + + align:start position:0% +container of size three their gcd is one + + + align:start position:0% +container of size three their gcd is one +they have basically no common divisors + + align:start position:0% +they have basically no common divisors + + + align:start position:0% +they have basically no common divisors +except one and minus one uh and we can + + align:start position:0% +except one and minus one uh and we can + + + align:start position:0% +except one and minus one uh and we can +represent the gcd as an integer linear + + align:start position:0% +represent the gcd as an integer linear + + + align:start position:0% +represent the gcd as an integer linear +combination of five and three namely + + align:start position:0% +combination of five and three namely + + + align:start position:0% +combination of five and three namely +this one therefore we can represent four + + align:start position:0% +this one therefore we can represent four + + + align:start position:0% +this one therefore we can represent four +as an integer linear combination of 5 + + align:start position:0% +as an integer linear combination of 5 + + + align:start position:0% +as an integer linear combination of 5 +and three we just multiply both sides by + + align:start position:0% +and three we just multiply both sides by + + + align:start position:0% +and three we just multiply both sides by +four and we get minus 4 * 5 plus 8 * 3 + + align:start position:0% +four and we get minus 4 * 5 plus 8 * 3 + + + align:start position:0% +four and we get minus 4 * 5 plus 8 * 3 +is one way to do it and uh that gives + + align:start position:0% +is one way to do it and uh that gives + + + align:start position:0% +is one way to do it and uh that gives +you at least a way to solve this problem + + align:start position:0% +you at least a way to solve this problem + + + align:start position:0% +you at least a way to solve this problem +problem it turns out you can take uh + + align:start position:0% +problem it turns out you can take uh + + + align:start position:0% +problem it turns out you can take uh +eight copies of three and subtract out + + align:start position:0% +eight copies of three and subtract out + + + align:start position:0% +eight copies of three and subtract out +four copies of five how do I do that um + + align:start position:0% +four copies of five how do I do that um + + + align:start position:0% +four copies of five how do I do that um +well I just fill this up eight times in + + align:start position:0% +well I just fill this up eight times in + + + align:start position:0% +well I just fill this up eight times in +total and each time I pour in uh all + + align:start position:0% +total and each time I pour in uh all + + + align:start position:0% +total and each time I pour in uh all +that I can into the thing of size five + + align:start position:0% +that I can into the thing of size five + + + align:start position:0% +that I can into the thing of size five +and each time it overflows I empty out + + align:start position:0% +and each time it overflows I empty out + + + align:start position:0% +and each time it overflows I empty out +the five and so that's exactly how I can + + align:start position:0% +the five and so that's exactly how I can + + + align:start position:0% +the five and so that's exactly how I can +build any integer linear combination of + + align:start position:0% +build any integer linear combination of + + + align:start position:0% +build any integer linear combination of +five and three by start as long as one + + align:start position:0% +five and three by start as long as one + + + align:start position:0% +five and three by start as long as one +side is positive and the other is + + align:start position:0% +side is positive and the other is + + + align:start position:0% +side is positive and the other is +negative which turns out to be necessary + + align:start position:0% +negative which turns out to be necessary + + + align:start position:0% +negative which turns out to be necessary +um then you can just take that many + + align:start position:0% +um then you can just take that many + + + align:start position:0% +um then you can just take that many +copies of filling up one bucket pouring + + align:start position:0% +copies of filling up one bucket pouring + + + align:start position:0% +copies of filling up one bucket pouring +it into the other removing whenever it + + align:start position:0% +it into the other removing whenever it + + + align:start position:0% +it into the other removing whenever it +overflows and you will get uh exactly + + align:start position:0% +overflows and you will get uh exactly + + + align:start position:0% +overflows and you will get uh exactly +the number you wanted for these numbers + + align:start position:0% +the number you wanted for these numbers + + + align:start position:0% +the number you wanted for these numbers +one two pores of three uh into five will + + align:start position:0% +one two pores of three uh into five will + + + align:start position:0% +one two pores of three uh into five will +give you one uh if you multiply this by + + align:start position:0% +give you one uh if you multiply this by + + + align:start position:0% +give you one uh if you multiply this by +four I get the number four and I save + + align:start position:0% +four I get the number four and I save + + + align:start position:0% +four I get the number four and I save +Manhattan + + align:start position:0% +Manhattan + + + align:start position:0% +Manhattan +great good luck on your quiz on Thursday \ No newline at end of file diff --git a/Xj4nKgJW5yE.txt b/Xj4nKgJW5yE.txt new file mode 100644 index 0000000000000000000000000000000000000000..107aaafe1039994859443f3a52379eeb7f46eef7 --- /dev/null +++ b/Xj4nKgJW5yE.txt @@ -0,0 +1,8795 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +now for a different entirely different + + align:start position:0% +now for a different entirely different + + + align:start position:0% +now for a different entirely different +type of issue that has more to do with + + align:start position:0% +type of issue that has more to do with + + + align:start position:0% +type of issue that has more to do with +recognition some psychophysics on + + align:start position:0% +recognition some psychophysics on + + + align:start position:0% +recognition some psychophysics on +computer vision but you will see at the + + align:start position:0% +computer vision but you will see at the + + + align:start position:0% +computer vision but you will see at the +end the motivation was really to be able + + align:start position:0% +end the motivation was really to be able + + + align:start position:0% +end the motivation was really to be able +to be able to recognize and understand + + align:start position:0% +to be able to recognize and understand + + + align:start position:0% +to be able to recognize and understand +really complicated things that are + + align:start position:0% +really complicated things that are + + + align:start position:0% +really complicated things that are +happening in natural images now when we + + align:start position:0% +happening in natural images now when we + + + align:start position:0% +happening in natural images now when we +look at it objects in the world people + + align:start position:0% +look at it objects in the world people + + + align:start position:0% +look at it objects in the world people +have worked a lot and object recognition + + align:start position:0% +have worked a lot and object recognition + + + align:start position:0% +have worked a lot and object recognition +and we can recognize we can recognize + + align:start position:0% +and we can recognize we can recognize + + + align:start position:0% +and we can recognize we can recognize +well complete objects but we can also + + align:start position:0% +well complete objects but we can also + + + align:start position:0% +well complete objects but we can also +recognize very limited configuration of + + align:start position:0% +recognize very limited configuration of + + + align:start position:0% +recognize very limited configuration of +objects so we are very good at using + + align:start position:0% +objects so we are very good at using + + + align:start position:0% +objects so we are very good at using +limited information if this is what's + + align:start position:0% +limited information if this is what's + + + align:start position:0% +limited information if this is what's +available in order to recognize what's + + align:start position:0% +available in order to recognize what's + + + align:start position:0% +available in order to recognize what's +in this is some arbitrary collection I + + align:start position:0% +in this is some arbitrary collection I + + + align:start position:0% +in this is some arbitrary collection I +guess you can recognize all of them some + + align:start position:0% +guess you can recognize all of them some + + + align:start position:0% +guess you can recognize all of them some +of them if you think about a person or + + align:start position:0% +of them if you think about a person or + + + align:start position:0% +of them if you think about a person or +even a face this is a very small part of + + align:start position:0% +even a face this is a very small part of + + + align:start position:0% +even a face this is a very small part of +a face everybody I guess knows what it + + align:start position:0% +a face everybody I guess knows what it + + + align:start position:0% +a face everybody I guess knows what it +is right it's not even a recognizable + + align:start position:0% +is right it's not even a recognizable + + + align:start position:0% +is right it's not even a recognizable +well delineated part like an eye you see + + align:start position:0% +well delineated part like an eye you see + + + align:start position:0% +well delineated part like an eye you see +a part of a person you know we know what + + align:start position:0% +a part of a person you know we know what + + + align:start position:0% +a part of a person you know we know what +it is right we don't I mean everybody + + align:start position:0% +it is right we don't I mean everybody + + + align:start position:0% +it is right we don't I mean everybody +recognizes and so on now I think that + + align:start position:0% +recognizes and so on now I think that + + + align:start position:0% +recognizes and so on now I think that +the ability to be able to get all the + + align:start position:0% +the ability to be able to get all the + + + align:start position:0% +the ability to be able to get all the +information out even from a limited + + align:start position:0% +information out even from a limited + + + align:start position:0% +information out even from a limited +region plays an important role in + + align:start position:0% +region plays an important role in + + + align:start position:0% +region plays an important role in +understanding images and let me motivate + + align:start position:0% +understanding images and let me motivate + + + align:start position:0% +understanding images and let me motivate +it by by one example I'll go back to it + + align:start position:0% +it by by one example I'll go back to it + + + align:start position:0% +it by by one example I'll go back to it +at the end when we look at these images + + align:start position:0% +at the end when we look at these images + + + align:start position:0% +at the end when we look at these images +we know what's happening we know what + + align:start position:0% +we know what's happening we know what + + + align:start position:0% +we know what's happening we know what +the action here is all the people are + + align:start position:0% +the action here is all the people are + + + align:start position:0% +the action here is all the people are +performing the same action all drinking + + align:start position:0% +performing the same action all drinking + + + align:start position:0% +performing the same action all drinking +even drinking from a bottle right but + + align:start position:0% +even drinking from a bottle right but + + + align:start position:0% +even drinking from a bottle right but +the images as images are very different + + align:start position:0% +the images as images are very different + + + align:start position:0% +the images as images are very different +if you look at each image if you stored + + align:start position:0% +if you look at each image if you stored + + + align:start position:0% +if you look at each image if you stored +one image and you try to recognize + + align:start position:0% +one image and you try to recognize + + + align:start position:0% +one image and you try to recognize +another image based on + + align:start position:0% +another image based on + + + align:start position:0% +another image based on +first one it would be difficult the + + align:start position:0% +first one it would be difficult the + + + align:start position:0% +first one it would be difficult the +variability here can be huge + + align:start position:0% +variability here can be huge + + + align:start position:0% +variability here can be huge +but if you focus on where the action + + align:start position:0% +but if you focus on where the action + + + align:start position:0% +but if you focus on where the action +really takes place the most informative + + align:start position:0% +really takes place the most informative + + + align:start position:0% +really takes place the most informative +part where most of the answer is already + + align:start position:0% +part where most of the answer is already + + + align:start position:0% +part where most of the answer is already +given to you what's happening here which + + align:start position:0% +given to you what's happening here which + + + align:start position:0% +given to you what's happening here which +is where the bottle is docked into the + + align:start position:0% +is where the bottle is docked into the + + + align:start position:0% +is where the bottle is docked into the +mouth you can see that now this diverse + + align:start position:0% +mouth you can see that now this diverse + + + align:start position:0% +mouth you can see that now this diverse +images becomes virtually almost a copy + + align:start position:0% +images becomes virtually almost a copy + + + align:start position:0% +images becomes virtually almost a copy +of one another right now almost the same + + align:start position:0% +of one another right now almost the same + + + align:start position:0% +of one another right now almost the same +so if you manage to understand this and + + align:start position:0% +so if you manage to understand this and + + + align:start position:0% +so if you manage to understand this and +extract the most informative part and + + align:start position:0% +extract the most informative part and + + + align:start position:0% +extract the most informative part and +although it's limited and so on the + + align:start position:0% +although it's limited and so on the + + + align:start position:0% +although it's limited and so on the +variability will be much much reduced + + align:start position:0% +variability will be much much reduced + + + align:start position:0% +variability will be much much reduced +variability here is much much reduced + + align:start position:0% +variability here is much much reduced + + + align:start position:0% +variability here is much much reduced +compared to variability that you have in + + align:start position:0% +compared to variability that you have in + + + align:start position:0% +compared to variability that you have in +the entire image so most of the other + + align:start position:0% +the entire image so most of the other + + + align:start position:0% +the entire image so most of the other +stuff is much less relevant but this is + + align:start position:0% +stuff is much less relevant but this is + + + align:start position:0% +stuff is much less relevant but this is +where the information is concentrated + + align:start position:0% +where the information is concentrated + + + align:start position:0% +where the information is concentrated +and in the limited restricted + + align:start position:0% +and in the limited restricted + + + align:start position:0% +and in the limited restricted +configuration recognition will be much + + align:start position:0% +configuration recognition will be much + + + align:start position:0% +configuration recognition will be much +easier and will generalize much better + + align:start position:0% +easier and will generalize much better + + + align:start position:0% +easier and will generalize much better +from one situation to another because of + + align:start position:0% +from one situation to another because of + + + align:start position:0% +from one situation to another because of +this principle of highly reduced + + align:start position:0% +this principle of highly reduced + + + align:start position:0% +this principle of highly reduced +variability in the in the limited image + + align:start position:0% +variability in the in the limited image + + + align:start position:0% +variability in the in the limited image +so we became interested as I say it's as + + align:start position:0% +so we became interested as I say it's as + + + align:start position:0% +so we became interested as I say it's as +you see it's useful but it's also to + + align:start position:0% +you see it's useful but it's also to + + + align:start position:0% +you see it's useful but it's also to +deal with small images and still + + align:start position:0% +deal with small images and still + + + align:start position:0% +deal with small images and still +recognize them limited images you will + + align:start position:0% +recognize them limited images you will + + + align:start position:0% +recognize them limited images you will +see it's much more there are some very + + align:start position:0% +see it's much more there are some very + + + align:start position:0% +see it's much more there are some very +challenging issues and I want to discuss + + align:start position:0% +challenging issues and I want to discuss + + + align:start position:0% +challenging issues and I want to discuss +it a little bit and then also discuss + + align:start position:0% +it a little bit and then also discuss + + + align:start position:0% +it a little bit and then also discuss +what it's good for + + align:start position:0% +what it's good for + + + align:start position:0% +what it's good for +a little bit more I will show you some + + align:start position:0% +a little bit more I will show you some + + + align:start position:0% +a little bit more I will show you some +human studies what we wanted to see is + + align:start position:0% +human studies what we wanted to see is + + + align:start position:0% +human studies what we wanted to see is +what are the sort of the minimal images + + align:start position:0% +what are the sort of the minimal images + + + align:start position:0% +what are the sort of the minimal images +that people can still recognize we + + align:start position:0% +that people can still recognize we + + + align:start position:0% +that people can still recognize we +examine some computation and models and + + align:start position:0% +examine some computation and models and + + + align:start position:0% +examine some computation and models and +I will give you sort of was not keep the + + align:start position:0% +I will give you sort of was not keep the + + + align:start position:0% +I will give you sort of was not keep the +secret it turns out that well performing + + align:start position:0% +secret it turns out that well performing + + + align:start position:0% +secret it turns out that well performing +current schemes including deep networks + + align:start position:0% +current schemes including deep networks + + + align:start position:0% +current schemes including deep networks +cannot deal well with such minimal + + align:start position:0% +cannot deal well with such minimal + + + align:start position:0% +cannot deal well with such minimal +images and from this I want to discuss + + align:start position:0% +images and from this I want to discuss + + + align:start position:0% +images and from this I want to discuss +some implications in terms of + + align:start position:0% +some implications in terms of + + + align:start position:0% +some implications in terms of +representations you know system brain + + align:start position:0% +representations you know system brain + + + align:start position:0% +representations you know system brain +processing and things like this and + + align:start position:0% +processing and things like this and + + + align:start position:0% +processing and things like this and +quite a number of people have been + + align:start position:0% +quite a number of people have been + + + align:start position:0% +quite a number of people have been +involved in this here are the names some + + align:start position:0% +involved in this here are the names some + + + align:start position:0% +involved in this here are the names some +of them are at the Weitzman Institute in + + align:start position:0% +of them are at the Weitzman Institute in + + + align:start position:0% +of them are at the Weitzman Institute in +Israel and a few lies here I see + + align:start position:0% +Israel and a few lies here I see + + + align:start position:0% +Israel and a few lies here I see +is here in the in the summer school and + + align:start position:0% +is here in the in the summer school and + + + align:start position:0% +is here in the in the summer school and +a student here Nahanni at MIT doing some + + align:start position:0% +a student here Nahanni at MIT doing some + + + align:start position:0% +a student here Nahanni at MIT doing some +brain imaging on this which I will + + align:start position:0% +brain imaging on this which I will + + + align:start position:0% +brain imaging on this which I will +mention very very briefly so I start + + align:start position:0% +mention very very briefly so I start + + + align:start position:0% +mention very very briefly so I start +with the human study we're looking for + + align:start position:0% +with the human study we're looking for + + + align:start position:0% +with the human study we're looking for +minimal sort of atomic things in + + align:start position:0% +minimal sort of atomic things in + + + align:start position:0% +minimal sort of atomic things in +recognition and the experiment goes like + + align:start position:0% +recognition and the experiment goes like + + + align:start position:0% +recognition and the experiment goes like +this you so subject an image and ask + + align:start position:0% +this you so subject an image and ask + + + align:start position:0% +this you so subject an image and ask +them to recognize it + + align:start position:0% +them to recognize it + + + align:start position:0% +them to recognize it +just put use a label so this is a dog if + + align:start position:0% +just put use a label so this is a dog if + + + align:start position:0% +just put use a label so this is a dog if +they say dog they recognized it and if + + align:start position:0% +they say dog they recognized it and if + + + align:start position:0% +they say dog they recognized it and if +they recognize it correctly we generate + + align:start position:0% +they recognize it correctly we generate + + + align:start position:0% +they recognize it correctly we generate +five descendants from this initial image + + align:start position:0% +five descendants from this initial image + + + align:start position:0% +five descendants from this initial image +if this image was say fifty by fifty + + align:start position:0% +if this image was say fifty by fifty + + + align:start position:0% +if this image was say fifty by fifty +pixels and tell you about pixels in a + + align:start position:0% +pixels and tell you about pixels in a + + + align:start position:0% +pixels and tell you about pixels in a +minute but say it's 50 by 50 pixels we + + align:start position:0% +minute but say it's 50 by 50 pixels we + + + align:start position:0% +minute but say it's 50 by 50 pixels we +make it somewhat smaller we reduce it + + align:start position:0% +make it somewhat smaller we reduce it + + + align:start position:0% +make it somewhat smaller we reduce it +because it's still not minimal and we + + align:start position:0% +because it's still not minimal and we + + + align:start position:0% +because it's still not minimal and we +reduce it in five ways we either copied + + align:start position:0% +reduce it in five ways we either copied + + + align:start position:0% +reduce it in five ways we either copied +in at one of the four corners to create + + align:start position:0% +in at one of the four corners to create + + + align:start position:0% +in at one of the four corners to create +say 48 by 48 image by taking two pixels + + align:start position:0% +say 48 by 48 image by taking two pixels + + + align:start position:0% +say 48 by 48 image by taking two pixels +from this corner here or this corner + + align:start position:0% +from this corner here or this corner + + + align:start position:0% +from this corner here or this corner +here and so on so for descendants and we + + align:start position:0% +here and so on so for descendants and we + + + align:start position:0% +here and so on so for descendants and we +generate we also take the full image + + align:start position:0% +generate we also take the full image + + + align:start position:0% +generate we also take the full image +keep it as is we do not crop it we just + + align:start position:0% +keep it as is we do not crop it we just + + + align:start position:0% +keep it as is we do not crop it we just +reduce the resolution so you release we + + align:start position:0% +reduce the resolution so you release we + + + align:start position:0% +reduce the resolution so you release we +resample it so some details start to + + align:start position:0% +resample it so some details start to + + + align:start position:0% +resample it so some details start to +become lost instead of 50 by 50 pixels + + align:start position:0% +become lost instead of 50 by 50 pixels + + + align:start position:0% +become lost instead of 50 by 50 pixels +it's also full image but 40 48 by 48 and + + align:start position:0% +it's also full image but 40 48 by 48 and + + + align:start position:0% +it's also full image but 40 48 by 48 and +then we give each one of these images + + align:start position:0% +then we give each one of these images + + + align:start position:0% +then we give each one of these images +now we have 5 we give each now 1 this is + + align:start position:0% +now we have 5 we give each now 1 this is + + + align:start position:0% +now we have 5 we give each now 1 this is +beginning to explained as a 3 each one + + align:start position:0% +beginning to explained as a 3 each one + + + align:start position:0% +beginning to explained as a 3 each one +of the 5 is given again to a subject if + + align:start position:0% +of the 5 is given again to a subject if + + + align:start position:0% +of the 5 is given again to a subject if +they recognize it again 5 descendants of + + align:start position:0% +they recognize it again 5 descendants of + + + align:start position:0% +they recognize it again 5 descendants of +being generated and we explore the + + align:start position:0% +being generated and we explore the + + + align:start position:0% +being generated and we explore the +entire tree until we find all the sub + + align:start position:0% +entire tree until we find all the sub + + + align:start position:0% +entire tree until we find all the sub +images which are minimal and can be + + align:start position:0% +images which are minimal and can be + + + align:start position:0% +images which are minimal and can be +recognizable in this original + + align:start position:0% +recognizable in this original + + + align:start position:0% +recognizable in this original +configuration now this is challenging + + align:start position:0% +configuration now this is challenging + + + align:start position:0% +configuration now this is challenging +psycho physically in terms of number of + + align:start position:0% +psycho physically in terms of number of + + + align:start position:0% +psycho physically in terms of number of +subjects because you can use a subject + + align:start position:0% +subjects because you can use a subject + + + align:start position:0% +subjects because you can use a subject +only once because if you show a subject + + align:start position:0% +only once because if you show a subject + + + align:start position:0% +only once because if you show a subject +this and you recognize it if you show + + align:start position:0% +this and you recognize it if you show + + + align:start position:0% +this and you recognize it if you show +him the same subject a reduced image he + + align:start position:0% +him the same subject a reduced image he + + + align:start position:0% +him the same subject a reduced image he +will recognize the image based on his + + align:start position:0% +will recognize the image based on his + + + align:start position:0% +will recognize the image based on his +previous exposure so you don't you do + + align:start position:0% +previous exposure so you don't you do + + + align:start position:0% +previous exposure so you don't you do +not want to use him again so you don't + + align:start position:0% +not want to use him again so you don't + + + align:start position:0% +not want to use him again so you don't +use him again and you show the other + + align:start position:0% +use him again and you show the other + + + align:start position:0% +use him again and you show the other +images to to new subject and this + + align:start position:0% +images to to new subject and this + + + align:start position:0% +images to to new subject and this +requires a large number of subjects or + + align:start position:0% +requires a large number of subjects or + + + align:start position:0% +requires a large number of subjects or +15 thousand subs + + align:start position:0% +15 thousand subs + + + align:start position:0% +15 thousand subs +participated in this experiment online + + align:start position:0% +participated in this experiment online + + + align:start position:0% +participated in this experiment online +by Mechanical Turk together with some + + align:start position:0% +by Mechanical Turk together with some + + + align:start position:0% +by Mechanical Turk together with some +laboratory controls to see that they are + + align:start position:0% +laboratory controls to see that they are + + + align:start position:0% +laboratory controls to see that they are +doing the right thing and how it + + align:start position:0% +doing the right thing and how it + + + align:start position:0% +doing the right thing and how it +compares with the same experiment done + + align:start position:0% +compares with the same experiment done + + + align:start position:0% +compares with the same experiment done +under laboratory conditions and so on so + + align:start position:0% +under laboratory conditions and so on so + + + align:start position:0% +under laboratory conditions and so on so +the way we define the minimal image for + + align:start position:0% +the way we define the minimal image for + + + align:start position:0% +the way we define the minimal image for +recognition is industry here is an image + + align:start position:0% +recognition is industry here is an image + + + align:start position:0% +recognition is industry here is an image +the image suppose if this image is + + align:start position:0% +the image suppose if this image is + + + align:start position:0% +the image suppose if this image is +recognizable and then we create the five + + align:start position:0% +recognizable and then we create the five + + + align:start position:0% +recognizable and then we create the five +descendants and none of the descendants + + align:start position:0% +descendants and none of the descendants + + + align:start position:0% +descendants and none of the descendants +is recognizable so this is recognizable + + align:start position:0% +is recognizable so this is recognizable + + + align:start position:0% +is recognizable so this is recognizable +nothing here is recognizable so it's + + align:start position:0% +nothing here is recognizable so it's + + + align:start position:0% +nothing here is recognizable so it's +minimal because you can no longer reduce + + align:start position:0% +minimal because you can no longer reduce + + + align:start position:0% +minimal because you can no longer reduce +it either by resolution going here or by + + align:start position:0% +it either by resolution going here or by + + + align:start position:0% +it either by resolution going here or by +reducing the size any manipulation like + + align:start position:0% +reducing the size any manipulation like + + + align:start position:0% +reducing the size any manipulation like +this we make it an unrecognizable + + align:start position:0% +this we make it an unrecognizable + + + align:start position:0% +this we make it an unrecognizable +technically when I'm am i measuring if + + align:start position:0% +technically when I'm am i measuring if + + + align:start position:0% +technically when I'm am i measuring if +I'm using numbers that the image is 50 + + align:start position:0% +I'm using numbers that the image is 50 + + + align:start position:0% +I'm using numbers that the image is 50 +50 pixels or 35 pixels and so on what I + + align:start position:0% +50 pixels or 35 pixels and so on what I + + + align:start position:0% +50 pixels or 35 pixels and so on what I +it's actually well defined or I mean not + + align:start position:0% +it's actually well defined or I mean not + + + align:start position:0% +it's actually well defined or I mean not +the pixels on the screen you can take + + align:start position:0% +the pixels on the screen you can take + + + align:start position:0% +the pixels on the screen you can take +the image and make it bigger or smaller + + align:start position:0% +the image and make it bigger or smaller + + + align:start position:0% +the image and make it bigger or smaller +on this on the screen but the number of + + align:start position:0% +on this on the screen but the number of + + + align:start position:0% +on this on the screen but the number of +sampling points in the image is + + align:start position:0% +sampling points in the image is + + + align:start position:0% +sampling points in the image is +well-defined which give me an image + + align:start position:0% +well-defined which give me an image + + + align:start position:0% +well-defined which give me an image +particular image I can tell you how many + + align:start position:0% +particular image I can tell you how many + + + align:start position:0% +particular image I can tell you how many +sample points you need in order to + + align:start position:0% +sample points you need in order to + + + align:start position:0% +sample points you need in order to +capture this image technically for those + + align:start position:0% +capture this image technically for those + + + align:start position:0% +capture this image technically for those +of you who know it's twice the if you do + + align:start position:0% +of you who know it's twice the if you do + + + align:start position:0% +of you who know it's twice the if you do +a Fourier transform and take the twice + + align:start position:0% +a Fourier transform and take the twice + + + align:start position:0% +a Fourier transform and take the twice +the cutoff frequency the highest + + align:start position:0% +the cutoff frequency the highest + + + align:start position:0% +the cutoff frequency the highest +frequency in the free aspect this is by + + align:start position:0% +frequency in the free aspect this is by + + + align:start position:0% +frequency in the free aspect this is by +the sampling theorem of Shannon this is + + align:start position:0% +the sampling theorem of Shannon this is + + + align:start position:0% +the sampling theorem of Shannon this is +the number of points you need in order + + align:start position:0% +the number of points you need in order + + + align:start position:0% +the number of points you need in order +to so when I say that the image was 35 + + align:start position:0% +to so when I say that the image was 35 + + + align:start position:0% +to so when I say that the image was 35 +pixels I don't really care you can make + + align:start position:0% +pixels I don't really care you can make + + + align:start position:0% +pixels I don't really care you can make +it somewhat smaller larger on the screen + + align:start position:0% +it somewhat smaller larger on the screen + + + align:start position:0% +it somewhat smaller larger on the screen +by interpolation it doesn't change the + + align:start position:0% +by interpolation it doesn't change the + + + align:start position:0% +by interpolation it doesn't change the +information content it's well defined + + align:start position:0% +information content it's well defined + + + align:start position:0% +information content it's well defined +the notion mathematically how many + + align:start position:0% +the notion mathematically how many + + + align:start position:0% +the notion mathematically how many +points in this discrete point for + + align:start position:0% +points in this discrete point for + + + align:start position:0% +points in this discrete point for +sampling points in this in these images + + align:start position:0% +sampling points in this in these images + + + align:start position:0% +sampling points in this in these images +so a very interesting thing that we we + + align:start position:0% +so a very interesting thing that we we + + + align:start position:0% +so a very interesting thing that we we +found when we found this minimal images + + align:start position:0% +found when we found this minimal images + + + align:start position:0% +found when we found this minimal images +is that there is a sharp transition when + + align:start position:0% +is that there is a sharp transition when + + + align:start position:0% +is that there is a sharp transition when +you get to live to the level of the + + align:start position:0% +you get to live to the level of the + + + align:start position:0% +you get to live to the level of the +minimal images so you go down and you + + align:start position:0% +minimal images so you go down and you + + + align:start position:0% +minimal images so you go down and you +recognize it and then there is a sharp + + align:start position:0% +recognize it and then there is a sharp + + + align:start position:0% +recognize it and then there is a sharp +transition that + + align:start position:0% +transition that + + + align:start position:0% +transition that +it suddenly becomes unrecognizable + + align:start position:0% +it suddenly becomes unrecognizable + + + align:start position:0% +it suddenly becomes unrecognizable +basically to the large majority of + + align:start position:0% +basically to the large majority of + + + align:start position:0% +basically to the large majority of +people so it can change a little bit and + + align:start position:0% +people so it can change a little bit and + + + align:start position:0% +people so it can change a little bit and +I'll show you some examples for you to + + align:start position:0% +I'll show you some examples for you to + + + align:start position:0% +I'll show you some examples for you to +try to see how this minimal images look + + align:start position:0% +try to see how this minimal images look + + + align:start position:0% +try to see how this minimal images look +like a recognizable level at the + + align:start position:0% +like a recognizable level at the + + + align:start position:0% +like a recognizable level at the +unrecognized but this is the recognizer + + align:start position:0% +unrecognized but this is the recognizer + + + align:start position:0% +unrecognized but this is the recognizer +believe that this is the unrecognizable + + align:start position:0% +believe that this is the unrecognizable + + + align:start position:0% +believe that this is the unrecognizable +level so to show it to you as examples + + align:start position:0% +level so to show it to you as examples + + + align:start position:0% +level so to show it to you as examples +here that I will show you first the + + align:start position:0% +here that I will show you first the + + + align:start position:0% +here that I will show you first the +unrecognizable one the one which people + + align:start position:0% +unrecognizable one the one which people + + + align:start position:0% +unrecognizable one the one which people +find on average more difficult to + + align:start position:0% +find on average more difficult to + + + align:start position:0% +find on average more difficult to +recognize if you recognize it raise your + + align:start position:0% +recognize if you recognize it raise your + + + align:start position:0% +recognize if you recognize it raise your +hand don't say what you see because this + + align:start position:0% +hand don't say what you see because this + + + align:start position:0% +hand don't say what you see because this +will influence other people just raise + + align:start position:0% +will influence other people just raise + + + align:start position:0% +will influence other people just raise +your hand if you recognize the image and + + align:start position:0% +your hand if you recognize the image and + + + align:start position:0% +your hand if you recognize the image and +then I'll show you the Molech ignitable + + align:start position:0% +then I'll show you the Molech ignitable + + + align:start position:0% +then I'll show you the Molech ignitable +one and let's see if more hands show up + + align:start position:0% +one and let's see if more hands show up + + + align:start position:0% +one and let's see if more hands show up +with the distinction between the + + align:start position:0% +with the distinction between the + + + align:start position:0% +with the distinction between the +recognizable in unrecognizable holes + + align:start position:0% +recognizable in unrecognizable holes + + + align:start position:0% +recognizable in unrecognizable holes +here I'll just show you a couple of + + align:start position:0% +here I'll just show you a couple of + + + align:start position:0% +here I'll just show you a couple of +example from the okay so okay so this is + + align:start position:0% +example from the okay so okay so this is + + + align:start position:0% +example from the okay so okay so this is +the one which is supposed to be + + align:start position:0% +the one which is supposed to be + + + align:start position:0% +the one which is supposed to be +difficult to recognize if you see what + + align:start position:0% +difficult to recognize if you see what + + + align:start position:0% +difficult to recognize if you see what +it is if you know what's the object + + align:start position:0% +it is if you know what's the object + + + align:start position:0% +it is if you know what's the object +raise your hand okay don't say what it + + align:start position:0% +raise your hand okay don't say what it + + + align:start position:0% +raise your hand okay don't say what it +is we have to let's see here okay + + align:start position:0% +is we have to let's see here okay + + + align:start position:0% +is we have to let's see here okay +certainly more hand what do you see what + + align:start position:0% +certainly more hand what do you see what + + + align:start position:0% +certainly more hand what do you see what +do you think okay + + align:start position:0% +do you think okay + + + align:start position:0% +do you think okay +now you can say because a horse right so + + align:start position:0% +now you can say because a horse right so + + + align:start position:0% +now you can say because a horse right so +let me show them side by side so you see + + align:start position:0% +let me show them side by side so you see + + + align:start position:0% +let me show them side by side so you see +that it's very difficult to recognize + + align:start position:0% +that it's very difficult to recognize + + + align:start position:0% +that it's very difficult to recognize +what not record this is you can see the + + align:start position:0% +what not record this is you can see the + + + align:start position:0% +what not record this is you can see the +statistic this is recognized by 93 + + align:start position:0% +statistic this is recognized by 93 + + + align:start position:0% +statistic this is recognized by 93 +percent of the subjects 30 subjects so + + align:start position:0% +percent of the subjects 30 subjects so + + + align:start position:0% +percent of the subjects 30 subjects so +each one of these images 93 recognize + + align:start position:0% +each one of these images 93 recognize + + + align:start position:0% +each one of these images 93 recognize +this 3% recognized this and you look at + + align:start position:0% +this 3% recognized this and you look at + + + align:start position:0% +this 3% recognized this and you look at +the image and you see that a very very + + align:start position:0% +the image and you see that a very very + + + align:start position:0% +the image and you see that a very very +similar images and it drops on ninety + + align:start position:0% +similar images and it drops on ninety + + + align:start position:0% +similar images and it drops on ninety +two three so you can see the two images + + align:start position:0% +two three so you can see the two images + + + align:start position:0% +two three so you can see the two images +and you can see the similarity and you + + align:start position:0% +and you can see the similarity and you + + + align:start position:0% +and you can see the similarity and you +can see the large the loud drop this is + + align:start position:0% +can see the large the loud drop this is + + + align:start position:0% +can see the large the loud drop this is +part of the entire tree which is being + + align:start position:0% +part of the entire tree which is being + + + align:start position:0% +part of the entire tree which is being +explored this is the father this is the + + align:start position:0% +explored this is the father this is the + + + align:start position:0% +explored this is the father this is the +recognized one the minimal image and you + + align:start position:0% +recognized one the minimal image and you + + + align:start position:0% +recognized one the minimal image and you +can see that even reduce the resolution + + align:start position:0% +can see that even reduce the resolution + + + align:start position:0% +can see that even reduce the resolution +which is really not a big manipulation + + align:start position:0% +which is really not a big manipulation + + + align:start position:0% +which is really not a big manipulation +but it is a drop in performance and you + + align:start position:0% +but it is a drop in performance and you + + + align:start position:0% +but it is a drop in performance and you +can see all the so we used 50% as our + + align:start position:0% +can see all the so we used 50% as our + + + align:start position:0% +can see all the so we used 50% as our +criterion so the parent should be + + align:start position:0% +criterion so the parent should be + + + align:start position:0% +criterion so the parent should be +recognized at higher this should be + + align:start position:0% +recognized at higher this should be + + + align:start position:0% +recognized at higher this should be +recognized + + align:start position:0% +recognized + + + align:start position:0% +recognized +loyal but typically the the jump is very + + align:start position:0% +loyal but typically the the jump is very + + + align:start position:0% +loyal but typically the the jump is very +it's very sharp let's write two more or + + align:start position:0% +it's very sharp let's write two more or + + + align:start position:0% +it's very sharp let's write two more or +something and then just for fun if you + + align:start position:0% +something and then just for fun if you + + + align:start position:0% +something and then just for fun if you +can recognize it raise your hand + + align:start position:0% + + + + align:start position:0% + +nobody or just for the record okay look + + align:start position:0% +nobody or just for the record okay look + + + align:start position:0% +nobody or just for the record okay look +around you can see many what do you see + + align:start position:0% +around you can see many what do you see + + + align:start position:0% +around you can see many what do you see +both right so you can see the two images + + align:start position:0% +both right so you can see the two images + + + align:start position:0% +both right so you can see the two images +or 80% and this 0% here and you can see + + align:start position:0% +or 80% and this 0% here and you can see + + + align:start position:0% +or 80% and this 0% here and you can see +that what's really missing here is the + + align:start position:0% +that what's really missing here is the + + + align:start position:0% +that what's really missing here is the +tip here and clearly this tip is there + + align:start position:0% +tip here and clearly this tip is there + + + align:start position:0% +tip here and clearly this tip is there +are many contours in this image but this + + align:start position:0% +are many contours in this image but this + + + align:start position:0% +are many contours in this image but this +particular corner sharp makes an + + align:start position:0% +particular corner sharp makes an + + + align:start position:0% +particular corner sharp makes an +enormous different and it goes from 80% + + align:start position:0% +enormous different and it goes from 80% + + + align:start position:0% +enormous different and it goes from 80% +to to 0% okay just one more in this is + + align:start position:0% +to to 0% okay just one more in this is + + + align:start position:0% +to to 0% okay just one more in this is +somewhat easier okay this is some fun + + align:start position:0% +somewhat easier okay this is some fun + + + align:start position:0% +somewhat easier okay this is some fun +okay it is one two and three okay this + + align:start position:0% +okay it is one two and three okay this + + + align:start position:0% +okay it is one two and three okay this +one everybody I think or maybe we are + + align:start position:0% +one everybody I think or maybe we are + + + align:start position:0% +one everybody I think or maybe we are +missing one + + align:start position:0% +missing one + + + align:start position:0% +missing one +so again you can see that the difference + + align:start position:0% +so again you can see that the difference + + + align:start position:0% +so again you can see that the difference +if you look at the two there is a + + align:start position:0% +if you look at the two there is a + + + align:start position:0% +if you look at the two there is a +difference and it's this thing here but + + align:start position:0% +difference and it's this thing here but + + + align:start position:0% +difference and it's this thing here but +it's not a very big part of the image + + align:start position:0% +it's not a very big part of the image + + + align:start position:0% +it's not a very big part of the image +it's crucial you know it's you have to + + align:start position:0% +it's crucial you know it's you have to + + + align:start position:0% +it's crucial you know it's you have to +be trained on this you have it's part of + + align:start position:0% +be trained on this you have it's part of + + + align:start position:0% +be trained on this you have it's part of +your representation it's important you + + align:start position:0% +your representation it's important you + + + align:start position:0% +your representation it's important you +go from almost 90 percent or 15 percent + + align:start position:0% +go from almost 90 percent or 15 percent + + + align:start position:0% +go from almost 90 percent or 15 percent +roughly in its so it's an important so + + align:start position:0% +roughly in its so it's an important so + + + align:start position:0% +roughly in its so it's an important so +you can see that the drop is typically + + align:start position:0% +you can see that the drop is typically + + + align:start position:0% +you can see that the drop is typically +very very sharp and it's also into you + + align:start position:0% +very very sharp and it's also into you + + + align:start position:0% +very very sharp and it's also into you +know the sharp transition is also + + align:start position:0% +know the sharp transition is also + + + align:start position:0% +know the sharp transition is also +interesting in the sense that if it + + align:start position:0% +interesting in the sense that if it + + + align:start position:0% +interesting in the sense that if it +drops from like from 90% to Tempe to 3% + + align:start position:0% +drops from like from 90% to Tempe to 3% + + + align:start position:0% +drops from like from 90% to Tempe to 3% +or even here it also says that we all + + align:start position:0% +or even here it also says that we all + + + align:start position:0% +or even here it also says that we all +carry around in our head a very similar + + align:start position:0% +carry around in our head a very similar + + + align:start position:0% +carry around in our head a very similar +representation because if each one of us + + align:start position:0% +representation because if each one of us + + + align:start position:0% +representation because if each one of us +based on the history an expiry + + align:start position:0% +based on the history an expiry + + + align:start position:0% +based on the history an expiry +experience would be less of more + + align:start position:0% +experience would be less of more + + + align:start position:0% +experience would be less of more +sensitive to various feature then we + + align:start position:0% +sensitive to various feature then we + + + align:start position:0% +sensitive to various feature then we +will not find this sharp transition + + align:start position:0% +will not find this sharp transition + + + align:start position:0% +will not find this sharp transition +different people will lose it at + + align:start position:0% +different people will lose it at + + + align:start position:0% +different people will lose it at +different different points in the in the + + align:start position:0% +different different points in the in the + + + align:start position:0% +different different points in the in the +manipulation but at 90 percent 90 + + align:start position:0% +manipulation but at 90 percent 90 + + + align:start position:0% +manipulation but at 90 percent 90 +percent of the people roughly everybody + + align:start position:0% +percent of the people roughly everybody + + + align:start position:0% +percent of the people roughly everybody +recognize it you remove a feature and it + + align:start position:0% +recognize it you remove a feature and it + + + align:start position:0% +recognize it you remove a feature and it +goes to 3 percent so everybody is using + + align:start position:0% +goes to 3 percent so everybody is using + + + align:start position:0% +goes to 3 percent so everybody is using +the same + + align:start position:0% +the same + + + align:start position:0% +the same +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +a very similar representation which I + + align:start position:0% +a very similar representation which I + + + align:start position:0% +a very similar representation which I +find somewhat surprising at least for + + align:start position:0% +find somewhat surprising at least for + + + align:start position:0% +find somewhat surprising at least for +some of these images you know that we + + align:start position:0% +some of these images you know that we + + + align:start position:0% +some of these images you know that we +don't all have the same kind of + + align:start position:0% +don't all have the same kind of + + + align:start position:0% +don't all have the same kind of +experience with horses or with + + align:start position:0% +experience with horses or with + + + align:start position:0% +experience with horses or with +battleships or things like that and + + align:start position:0% +battleships or things like that and + + + align:start position:0% +battleships or things like that and +still the representation is very + + align:start position:0% +still the representation is very + + + align:start position:0% +still the representation is very +strikingly similar across individuals + + align:start position:0% +strikingly similar across individuals + + + align:start position:0% +strikingly similar across individuals +the experiment was done on 10 different + + align:start position:0% +the experiment was done on 10 different + + + align:start position:0% +the experiment was done on 10 different +objects these are the initial objects or + + align:start position:0% +objects these are the initial objects or + + + align:start position:0% +objects these are the initial objects or +I showed you the object all right + + align:start position:0% +I showed you the object all right + + + align:start position:0% +I showed you the object all right +beginning of the hierarchy and then you + + align:start position:0% +beginning of the hierarchy and then you + + + align:start position:0% +beginning of the hierarchy and then you +start the manipulation to discover all + + align:start position:0% +start the manipulation to discover all + + + align:start position:0% +start the manipulation to discover all +the minimal images inside them and here + + align:start position:0% +the minimal images inside them and here + + + align:start position:0% +the minimal images inside them and here +so we ended up with a very nice catalog + + align:start position:0% +so we ended up with a very nice catalog + + + align:start position:0% +so we ended up with a very nice catalog +we have a database of all the minimal + + align:start position:0% +we have a database of all the minimal + + + align:start position:0% +we have a database of all the minimal +images in all of these ten images in all + + align:start position:0% +images in all of these ten images in all + + + align:start position:0% +images in all of these ten images in all +of the children the unrecognizable ones + + align:start position:0% +of the children the unrecognizable ones + + + align:start position:0% +of the children the unrecognizable ones +so in terms of modeling and in terms of + + align:start position:0% +so in terms of modeling and in terms of + + + align:start position:0% +so in terms of modeling and in terms of +exploring visual features and what is + + align:start position:0% +exploring visual features and what is + + + align:start position:0% +exploring visual features and what is +necessary in order to recognize and so + + align:start position:0% +necessary in order to recognize and so + + + align:start position:0% +necessary in order to recognize and so +on there is a very rich data set here of + + align:start position:0% +on there is a very rich data set here of + + + align:start position:0% +on there is a very rich data set here of +all the minimal images in all of these + + align:start position:0% +all the minimal images in all of these + + + align:start position:0% +all the minimal images in all of these +ten images here are some more pairs of + + align:start position:0% +ten images here are some more pairs of + + + align:start position:0% +ten images here are some more pairs of +recognizable and unrecognizable rocky + + align:start position:0% +recognizable and unrecognizable rocky + + + align:start position:0% +recognizable and unrecognizable rocky +bodies so this in principle but just to + + align:start position:0% +bodies so this in principle but just to + + + align:start position:0% +bodies so this in principle but just to +show some in some cases it's pretty + + align:start position:0% +show some in some cases it's pretty + + + align:start position:0% +show some in some cases it's pretty +clear what may be going on for example + + align:start position:0% +clear what may be going on for example + + + align:start position:0% +clear what may be going on for example +this is horse legs the front legs of the + + align:start position:0% +this is horse legs the front legs of the + + + align:start position:0% +this is horse legs the front legs of the +horse this seems to be important you can + + align:start position:0% +horse this seems to be important you can + + + align:start position:0% +horse this seems to be important you can +see that very often it's a tremendously + + align:start position:0% +see that very often it's a tremendously + + + align:start position:0% +see that very often it's a tremendously +small in this fly image very small + + align:start position:0% +small in this fly image very small + + + align:start position:0% +small in this fly image very small +differences very hard to pinpoint and + + align:start position:0% +differences very hard to pinpoint and + + + align:start position:0% +differences very hard to pinpoint and +it's drastic or in this in the + + align:start position:0% +it's drastic or in this in the + + + align:start position:0% +it's drastic or in this in the +eyeglasses something here is missing a + + align:start position:0% +eyeglasses something here is missing a + + + align:start position:0% +eyeglasses something here is missing a +little bit but very small things in very + + align:start position:0% +little bit but very small things in very + + + align:start position:0% +little bit but very small things in very +reliable way cause this dramatic change + + align:start position:0% +reliable way cause this dramatic change + + + align:start position:0% +reliable way cause this dramatic change +as was mentioned here somebody mentioned + + align:start position:0% +as was mentioned here somebody mentioned + + + align:start position:0% +as was mentioned here somebody mentioned +would say the inflection in point you + + align:start position:0% +would say the inflection in point you + + + align:start position:0% +would say the inflection in point you +can manipulate psycho physically a bit + + align:start position:0% +can manipulate psycho physically a bit + + + align:start position:0% +can manipulate psycho physically a bit +more for example here this was a this is + + align:start position:0% +more for example here this was a this is + + + align:start position:0% +more for example here this was a this is +another version of a minimal image it + + align:start position:0% +another version of a minimal image it + + + align:start position:0% +another version of a minimal image it +was co-opted two locations you can crop + + align:start position:0% +was co-opted two locations you can crop + + + align:start position:0% +was co-opted two locations you can crop +only the left side you can crop only the + + align:start position:0% +only the left side you can crop only the + + + align:start position:0% +only the left side you can crop only the +the bottom side and you can try to see + + align:start position:0% +the bottom side and you can try to see + + + align:start position:0% +the bottom side and you can try to see +what makes it different so you can + + align:start position:0% +what makes it different so you can + + + align:start position:0% +what makes it different so you can +really zoom in on the on the critical on + + align:start position:0% +really zoom in on the on the critical on + + + align:start position:0% +really zoom in on the on the critical on +the critical features in terms of number + + align:start position:0% +the critical features in terms of number + + + align:start position:0% +the critical features in terms of number +of pixels the impression is that it's + + align:start position:0% +of pixels the impression is that it's + + + align:start position:0% +of pixels the impression is that it's +surprisingly + + align:start position:0% +surprisingly + + + align:start position:0% +surprisingly +small so I guess you can recognize this + + align:start position:0% +small so I guess you can recognize this + + + align:start position:0% +small so I guess you can recognize this +is an ego this is an airplane and the + + align:start position:0% +is an ego this is an airplane and the + + + align:start position:0% +is an ego this is an airplane and the +number of pixels you know you're right + + align:start position:0% +number of pixels you know you're right + + + align:start position:0% +number of pixels you know you're right +in your you know those of you know + + align:start position:0% +in your you know those of you know + + + align:start position:0% +in your you know those of you know +vision your retinas has 120 million + + align:start position:0% +vision your retinas has 120 million + + + align:start position:0% +vision your retinas has 120 million +pixels the fovea which is the area of + + align:start position:0% +pixels the fovea which is the area of + + + align:start position:0% +pixels the fovea which is the area of +very high acuity is two degrees it's + + align:start position:0% +very high acuity is two degrees it's + + + align:start position:0% +very high acuity is two degrees it's +about 250 by 250 250 by 200 pixels this + + align:start position:0% +about 250 by 250 250 by 200 pixels this + + + align:start position:0% +about 250 by 250 250 by 200 pixels this +is the area the central area of high + + align:start position:0% +is the area the central area of high + + + align:start position:0% +is the area the central area of high +acuity but you can recognize things with + + align:start position:0% +acuity but you can recognize things with + + + align:start position:0% +acuity but you can recognize things with +I don't know 15 20 pixels it's one-tenth + + align:start position:0% +I don't know 15 20 pixels it's one-tenth + + + align:start position:0% +I don't know 15 20 pixels it's one-tenth +of your your fovea it's tiny time in + + align:start position:0% +of your your fovea it's tiny time in + + + align:start position:0% +of your your fovea it's tiny time in +terms of you can make it larger but in + + align:start position:0% +terms of you can make it larger but in + + + align:start position:0% +terms of you can make it larger but in +terms of how much visual information + + align:start position:0% +terms of how much visual information + + + align:start position:0% +terms of how much visual information +it's I find it surprising that you need + + align:start position:0% +it's I find it surprising that you need + + + align:start position:0% +it's I find it surprising that you need +very very little it's also interesting + + align:start position:0% +very very little it's also interesting + + + align:start position:0% +very very little it's also interesting +that it's it's very useful in the center + + align:start position:0% +that it's it's very useful in the center + + + align:start position:0% +that it's it's very useful in the center +it's it's very redundant if you if you + + align:start position:0% +it's it's very redundant if you if you + + + align:start position:0% +it's it's very redundant if you if you +have the capacity if you have a visual + + align:start position:0% +have the capacity if you have a visual + + + align:start position:0% +have the capacity if you have a visual +system that can recognize individually + + align:start position:0% +system that can recognize individually + + + align:start position:0% +system that can recognize individually +each one of these minimal images and in + + align:start position:0% +each one of these minimal images and in + + + align:start position:0% +each one of these minimal images and in +fact they can be recognized on their own + + align:start position:0% +fact they can be recognized on their own + + + align:start position:0% +fact they can be recognized on their own +then a full image like this contains a + + align:start position:0% +then a full image like this contains a + + + align:start position:0% +then a full image like this contains a +high number of partially overlapping + + align:start position:0% +high number of partially overlapping + + + align:start position:0% +high number of partially overlapping +minimal images some of them are large + + align:start position:0% +minimal images some of them are large + + + align:start position:0% +minimal images some of them are large +you can see each one of this frame + + align:start position:0% +you can see each one of this frame + + + align:start position:0% +you can see each one of this frame +colored frame is a minimal image shown + + align:start position:0% +colored frame is a minimal image shown + + + align:start position:0% +colored frame is a minimal image shown +not necessarily at the right resolution + + align:start position:0% +not necessarily at the right resolution + + + align:start position:0% +not necessarily at the right resolution +you can reduce the resolution of things + + align:start position:0% +you can reduce the resolution of things + + + align:start position:0% +you can reduce the resolution of things +but you can see that some images of + + align:start position:0% +but you can see that some images of + + + align:start position:0% +but you can see that some images of +essentially low resolution + + align:start position:0% +essentially low resolution + + + align:start position:0% +essentially low resolution +representations of the entire object + + align:start position:0% +representations of the entire object + + + align:start position:0% +representations of the entire object +like almost the entire eagle but some of + + align:start position:0% +like almost the entire eagle but some of + + + align:start position:0% +like almost the entire eagle but some of +them just contained something relatively + + align:start position:0% +them just contained something relatively + + + align:start position:0% +them just contained something relatively +small around the round around the head + + align:start position:0% +small around the round around the head + + + align:start position:0% +small around the round around the head +and the eye for the eye region you can + + align:start position:0% +and the eye for the eye region you can + + + align:start position:0% +and the eye for the eye region you can +see that some you can get a low + + align:start position:0% +see that some you can get a low + + + align:start position:0% +see that some you can get a low +resolution again saying of almost + + align:start position:0% +resolution again saying of almost + + + align:start position:0% +resolution again saying of almost +everything but you can just the corner + + align:start position:0% +everything but you can just the corner + + + align:start position:0% +everything but you can just the corner +of the eye and things like that are + + align:start position:0% +of the eye and things like that are + + + align:start position:0% +of the eye and things like that are +enough we find in general it seemed that + + align:start position:0% +enough we find in general it seemed that + + + align:start position:0% +enough we find in general it seemed that +things that are related to humans you + + align:start position:0% +things that are related to humans you + + + align:start position:0% +things that are related to humans you +have a large number of these minimal + + align:start position:0% +have a large number of these minimal + + + align:start position:0% +have a large number of these minimal +minimal images so they provide a + + align:start position:0% +minimal images so they provide a + + + align:start position:0% +minimal images so they provide a +sensitive tool to compare + + align:start position:0% +sensitive tool to compare + + + align:start position:0% +sensitive tool to compare +representations to see what's missing in + + align:start position:0% +representations to see what's missing in + + + align:start position:0% +representations to see what's missing in +the sub image which made the image + + align:start position:0% +the sub image which made the image + + + align:start position:0% +the sub image which made the image +become unrecognizable so + + align:start position:0% +become unrecognizable so + + + align:start position:0% +become unrecognizable so +we call them sometimes this economy + + align:start position:0% +we call them sometimes this economy + + + align:start position:0% +we call them sometimes this economy +minimal recognizable configuration we we + + align:start position:0% +minimal recognizable configuration we we + + + align:start position:0% +minimal recognizable configuration we we +call them configuration but not images + + align:start position:0% +call them configuration but not images + + + align:start position:0% +call them configuration but not images +not parts or not objects because now not + + align:start position:0% +not parts or not objects because now not + + + align:start position:0% +not parts or not objects because now not +objects and not parts because as we saw + + align:start position:0% +objects and not parts because as we saw + + + align:start position:0% +objects and not parts because as we saw +in the examples they do not have to be + + align:start position:0% +in the examples they do not have to be + + + align:start position:0% +in the examples they do not have to be +well delineated parts are more like + + align:start position:0% +well delineated parts are more like + + + align:start position:0% +well delineated parts are more like +local configuration but anyway minimal + + align:start position:0% +local configuration but anyway minimal + + + align:start position:0% +local configuration but anyway minimal +minimal images and the next thing that + + align:start position:0% +minimal images and the next thing that + + + align:start position:0% +minimal images and the next thing that +we did is we were wondering if this kind + + align:start position:0% +we did is we were wondering if this kind + + + align:start position:0% +we did is we were wondering if this kind +of behavior that the ability to + + align:start position:0% +of behavior that the ability to + + + align:start position:0% +of behavior that the ability to +recognize this the ability to recognize + + align:start position:0% +recognize this the ability to recognize + + + align:start position:0% +recognize this the ability to recognize +these images from such minimal + + align:start position:0% +these images from such minimal + + + align:start position:0% +these images from such minimal +information requires it places an + + align:start position:0% +information requires it places an + + + align:start position:0% +information requires it places an +interesting challenge in into + + align:start position:0% +interesting challenge in into + + + align:start position:0% +interesting challenge in into +interesting test of a recognition system + + align:start position:0% +interesting test of a recognition system + + + align:start position:0% +interesting test of a recognition system +because you really have to extract and + + align:start position:0% +because you really have to extract and + + + align:start position:0% +because you really have to extract and +use all the available information by + + align:start position:0% +use all the available information by + + + align:start position:0% +use all the available information by +definition this is minimal if you do not + + align:start position:0% +definition this is minimal if you do not + + + align:start position:0% +definition this is minimal if you do not +use all the information that's in this + + align:start position:0% +use all the information that's in this + + + align:start position:0% +use all the information that's in this +minimal image then you don't have the + + align:start position:0% +minimal image then you don't have the + + + align:start position:0% +minimal image then you don't have the +minimal information you have less than + + align:start position:0% +minimal information you have less than + + + align:start position:0% +minimal information you have less than +that and you will fail so a system that + + align:start position:0% +that and you will fail so a system that + + + align:start position:0% +that and you will fail so a system that +is not good enough will fail on this + + align:start position:0% +is not good enough will fail on this + + + align:start position:0% +is not good enough will fail on this +minimal images or the ability to + + align:start position:0% +minimal images or the ability to + + + align:start position:0% +minimal images or the ability to +recognize that means that you really can + + align:start position:0% +recognize that means that you really can + + + align:start position:0% +recognize that means that you really can +suck out all the all the relevant + + align:start position:0% +suck out all the all the relevant + + + align:start position:0% +suck out all the all the relevant +information out so we were wondering + + align:start position:0% +information out so we were wondering + + + align:start position:0% +information out so we were wondering +what will happen if we show it to + + align:start position:0% +what will happen if we show it to + + + align:start position:0% +what will happen if we show it to +various computation and algorithms that + + align:start position:0% +various computation and algorithms that + + + align:start position:0% +various computation and algorithms that +performs well perform well on full + + align:start position:0% +performs well perform well on full + + + align:start position:0% +performs well perform well on full +images what will happen when you + + align:start position:0% +images what will happen when you + + + align:start position:0% +images what will happen when you +challenge them with things which are by + + align:start position:0% +challenge them with things which are by + + + align:start position:0% +challenge them with things which are by +nature designed to be non redundant so + + align:start position:0% +nature designed to be non redundant so + + + align:start position:0% +nature designed to be non redundant so +here is I will do it it's not a computer + + align:start position:0% +here is I will do it it's not a computer + + + align:start position:0% +here is I will do it it's not a computer +vision school I will not go too much + + align:start position:0% +vision school I will not go too much + + + align:start position:0% +vision school I will not go too much +through the details of the computational + + align:start position:0% +through the details of the computational + + + align:start position:0% +through the details of the computational +scheme just to show you what what was + + align:start position:0% +scheme just to show you what what was + + + align:start position:0% +scheme just to show you what what was +happening and in the bottom line is that + + align:start position:0% +happening and in the bottom line is that + + + align:start position:0% +happening and in the bottom line is that +they are not doing a good job two things + + align:start position:0% +they are not doing a good job two things + + + align:start position:0% +they are not doing a good job two things +happen first of all when you train a + + align:start position:0% +happen first of all when you train a + + + align:start position:0% +happen first of all when you train a +computational system you do not see the + + align:start position:0% +computational system you do not see the + + + align:start position:0% +computational system you do not see the +same drop that you see here that it + + align:start position:0% +same drop that you see here that it + + + align:start position:0% +same drop that you see here that it +recognizes one it doesn't recognize the + + align:start position:0% +recognizes one it doesn't recognize the + + + align:start position:0% +recognizes one it doesn't recognize the +other you don't have a drop in + + align:start position:0% +other you don't have a drop in + + + align:start position:0% +other you don't have a drop in +recognition that the this sort of phase + + align:start position:0% +recognition that the this sort of phase + + + align:start position:0% +recognition that the this sort of phase +transition that characterizes the human + + align:start position:0% +transition that characterizes the human + + + align:start position:0% +transition that characterizes the human +visual system is not reproduced in any + + align:start position:0% +visual system is not reproduced in any + + + align:start position:0% +visual system is not reproduced in any +of the current recognition systems + + align:start position:0% +of the current recognition systems + + + align:start position:0% +of the current recognition systems +include + + align:start position:0% +include + + + align:start position:0% +include +did network in any any other ones and + + align:start position:0% +did network in any any other ones and + + + align:start position:0% +did network in any any other ones and +secondly they are not very good at + + align:start position:0% +secondly they are not very good at + + + align:start position:0% +secondly they are not very good at +recognizing them regardless of the gap + + align:start position:0% +recognizing them regardless of the gap + + + align:start position:0% +recognizing them regardless of the gap +that there is a sharp transition or not + + align:start position:0% +that there is a sharp transition or not + + + align:start position:0% +that there is a sharp transition or not +they do not get good recognition results + + align:start position:0% +they do not get good recognition results + + + align:start position:0% +they do not get good recognition results +on on this minimal images do not suck + + align:start position:0% +on on this minimal images do not suck + + + align:start position:0% +on on this minimal images do not suck +all the necessary information so in the + + align:start position:0% +all the necessary information so in the + + + align:start position:0% +all the necessary information so in the +fully images it's like we had a an image + + align:start position:0% +fully images it's like we had a an image + + + align:start position:0% +fully images it's like we had a an image +of a side view of a plane so we are + + align:start position:0% +of a side view of a plane so we are + + + align:start position:0% +of a side view of a plane so we are +training on airplane you can think about + + align:start position:0% +training on airplane you can think about + + + align:start position:0% +training on airplane you can think about +deep Network we actually try the whole + + align:start position:0% +deep Network we actually try the whole + + + align:start position:0% +deep Network we actually try the whole +range of good classifiers and in all of + + align:start position:0% +range of good classifiers and in all of + + + align:start position:0% +range of good classifiers and in all of +these good classifiers those of you are + + align:start position:0% +these good classifiers those of you are + + + align:start position:0% +these good classifiers those of you are +not in vision and probably got enough at + + align:start position:0% +not in vision and probably got enough at + + + align:start position:0% +not in vision and probably got enough at +the beginning of this summer school that + + align:start position:0% +the beginning of this summer school that + + + align:start position:0% +the beginning of this summer school that +they have a feeling for a classifier in + + align:start position:0% +they have a feeling for a classifier in + + + align:start position:0% +they have a feeling for a classifier in +computer vision it's a system that + + align:start position:0% +computer vision it's a system that + + + align:start position:0% +computer vision it's a system that +algorithm the system that scheme that + + align:start position:0% +algorithm the system that scheme that + + + align:start position:0% +algorithm the system that scheme that +you give it training images you don't + + align:start position:0% +you give it training images you don't + + + align:start position:0% +you give it training images you don't +have to specify you don't tell it what + + align:start position:0% +have to specify you don't tell it what + + + align:start position:0% +have to specify you don't tell it what +to look for you just give it lots of + + align:start position:0% +to look for you just give it lots of + + + align:start position:0% +to look for you just give it lots of +images and tell them all these are of + + align:start position:0% +images and tell them all these are of + + + align:start position:0% +images and tell them all these are of +the same class and then it calibrates + + align:start position:0% +the same class and then it calibrates + + + align:start position:0% +the same class and then it calibrates +itself and adjust parameters and so on + + align:start position:0% +itself and adjust parameters and so on + + + align:start position:0% +itself and adjust parameters and so on +and then you give it new images and the + + align:start position:0% +and then you give it new images and the + + + align:start position:0% +and then you give it new images and the +system is supposed to tell you if we + + align:start position:0% +system is supposed to tell you if we + + + align:start position:0% +system is supposed to tell you if we +belong it's a new member of the same + + align:start position:0% +belong it's a new member of the same + + + align:start position:0% +belong it's a new member of the same +class or not so in this case we train + + align:start position:0% +class or not so in this case we train + + + align:start position:0% +class or not so in this case we train +the system giving them full side views + + align:start position:0% +the system giving them full side views + + + align:start position:0% +the system giving them full side views +of airplane but then we gave them just + + align:start position:0% +of airplane but then we gave them just + + + align:start position:0% +of airplane but then we gave them just +the tails compared to random patches + + align:start position:0% +the tails compared to random patches + + + align:start position:0% +the tails compared to random patches +taking from long images the question is + + align:start position:0% +taking from long images the question is + + + align:start position:0% +taking from long images the question is +do they reliably can tell you that this + + align:start position:0% +do they reliably can tell you that this + + + align:start position:0% +do they reliably can tell you that this +is a tail of an airplane part of the + + align:start position:0% +is a tail of an airplane part of the + + + align:start position:0% +is a tail of an airplane part of the +previous plus a class or they would be + + align:start position:0% +previous plus a class or they would be + + + align:start position:0% +previous plus a class or they would be +confused and we will give even higher + + align:start position:0% +confused and we will give even higher + + + align:start position:0% +confused and we will give even higher +score to things which do not come from + + align:start position:0% +score to things which do not come from + + + align:start position:0% +score to things which do not come from +airplane at all so we started this when + + align:start position:0% +airplane at all so we started this when + + + align:start position:0% +airplane at all so we started this when +deep networks were still not the leaders + + align:start position:0% +deep networks were still not the leaders + + + align:start position:0% +deep networks were still not the leaders +and we had some other things like DPM + + align:start position:0% +and we had some other things like DPM + + + align:start position:0% +and we had some other things like DPM +and including H marks which is a very + + align:start position:0% +and including H marks which is a very + + + align:start position:0% +and including H marks which is a very +good model of the human visual system + + align:start position:0% +good model of the human visual system + + + align:start position:0% +good model of the human visual system +and performs very well and so we + + align:start position:0% +and performs very well and so we + + + align:start position:0% +and performs very well and so we +included it as well and deep networks as + + align:start position:0% +included it as well and deep networks as + + + align:start position:0% +included it as well and deep networks as +well this is the H marks + + align:start position:0% +well this is the H marks + + + align:start position:0% +well this is the H marks +this is convolutional neural networks + + align:start position:0% +this is convolutional neural networks + + + align:start position:0% +this is convolutional neural networks +you probably got the idea just worth + + align:start position:0% +you probably got the idea just worth + + + align:start position:0% +you probably got the idea just worth +pointing I find it interesting in the + + align:start position:0% +pointing I find it interesting in the + + + align:start position:0% +pointing I find it interesting in the +computer vision coming + + align:start position:0% +computer vision coming + + + align:start position:0% +computer vision coming +that it's a you have all implicates + + align:start position:0% +that it's a you have all implicates + + + align:start position:0% +that it's a you have all implicates +something which is very structured and + + align:start position:0% +something which is very structured and + + + align:start position:0% +something which is very structured and +very competitive and very nice in this + + align:start position:0% +very competitive and very nice in this + + + align:start position:0% +very competitive and very nice in this +regard that for that there is the Pascal + + align:start position:0% +regard that for that there is the Pascal + + + align:start position:0% +regard that for that there is the Pascal +challenge and the imagenet challenge and + + align:start position:0% +challenge and the imagenet challenge and + + + align:start position:0% +challenge and the imagenet challenge and +it's well run and people who think that + + align:start position:0% +it's well run and people who think that + + + align:start position:0% +it's well run and people who think that +they have a better algorithm than others + + align:start position:0% +they have a better algorithm than others + + + align:start position:0% +they have a better algorithm than others +can submit an entry can submit an + + align:start position:0% +can submit an entry can submit an + + + align:start position:0% +can submit an entry can submit an +algorithm everybody gets training images + + align:start position:0% +algorithm everybody gets training images + + + align:start position:0% +algorithm everybody gets training images +that are distributed publicly but there + + align:start position:0% +that are distributed publicly but there + + + align:start position:0% +that are distributed publicly but there +are secret images used for testing and + + align:start position:0% +are secret images used for testing and + + + align:start position:0% +are secret images used for testing and +you can train your algorithm on the + + align:start position:0% +you can train your algorithm on the + + + align:start position:0% +you can train your algorithm on the +available data everybody uses the same + + align:start position:0% +available data everybody uses the same + + + align:start position:0% +available data everybody uses the same +data and then you submit your algorithm + + align:start position:0% +data and then you submit your algorithm + + + align:start position:0% +data and then you submit your algorithm +and the algorithm is run by the Central + + align:start position:0% +and the algorithm is run by the Central + + + align:start position:0% +and the algorithm is run by the Central +Committee on the test images and the + + align:start position:0% +Committee on the test images and the + + + align:start position:0% +Committee on the test images and the +results are published and everybody + + align:start position:0% +results are published and everybody + + + align:start position:0% +results are published and everybody +knows who is number one with number two + + align:start position:0% +knows who is number one with number two + + + align:start position:0% +knows who is number one with number two +you have the gold medal and a silver + + align:start position:0% +you have the gold medal and a silver + + + align:start position:0% +you have the gold medal and a silver +model and medal + + align:start position:0% +model and medal + + + align:start position:0% +model and medal +it's it's very competitive and it's it + + align:start position:0% +it's it's very competitive and it's it + + + align:start position:0% +it's it's very competitive and it's it +in some sense it's doing very good + + align:start position:0% +in some sense it's doing very good + + + align:start position:0% +in some sense it's doing very good +things it's sort of driving the + + align:start position:0% +things it's sort of driving the + + + align:start position:0% +things it's sort of driving the +performance up it also has a negative + + align:start position:0% +performance up it also has a negative + + + align:start position:0% +performance up it also has a negative +effect on the I think on the way things + + align:start position:0% +effect on the I think on the way things + + + align:start position:0% +effect on the I think on the way things +are being done one negative it's very + + align:start position:0% +are being done one negative it's very + + + align:start position:0% +are being done one negative it's very +difficult to come up with an entirely + + align:start position:0% +difficult to come up with an entirely + + + align:start position:0% +difficult to come up with an entirely +new scheme which explores a completely + + align:start position:0% +new scheme which explores a completely + + + align:start position:0% +new scheme which explores a completely +new idea because initially before you + + align:start position:0% +new idea because initially before you + + + align:start position:0% +new idea because initially before you +find you need it will not be at the + + align:start position:0% +find you need it will not be at the + + + align:start position:0% +find you need it will not be at the +level of the high-performing winners + + align:start position:0% +level of the high-performing winners + + + align:start position:0% +level of the high-performing winners +until it establishes itself as a winner + + align:start position:0% +until it establishes itself as a winner + + + align:start position:0% +until it establishes itself as a winner +it will not get credit so it sort of + + align:start position:0% +it will not get credit so it sort of + + + align:start position:0% +it will not get credit so it sort of +becomes a little bit conservative in + + align:start position:0% +becomes a little bit conservative in + + + align:start position:0% +becomes a little bit conservative in +this in this regard which is the + + align:start position:0% +this in this regard which is the + + + align:start position:0% +this in this regard which is the +unfortunate part so as I told you and I + + align:start position:0% +unfortunate part so as I told you and I + + + align:start position:0% +unfortunate part so as I told you and I +will not go in great detail the two + + align:start position:0% +will not go in great detail the two + + + align:start position:0% +will not go in great detail the two +basic outcomes is that the gap between + + align:start position:0% +basic outcomes is that the gap between + + + align:start position:0% +basic outcomes is that the gap between +recognizable and unrecognizable these + + align:start position:0% +recognizable and unrecognizable these + + + align:start position:0% +recognizable and unrecognizable these +two bars or the gap for human vision + + align:start position:0% +two bars or the gap for human vision + + + align:start position:0% +two bars or the gap for human vision +that a whole group of horse images the + + align:start position:0% +that a whole group of horse images the + + + align:start position:0% +that a whole group of horse images the +parents are highly recognizable the + + align:start position:0% +parents are highly recognizable the + + + align:start position:0% +parents are highly recognizable the +children offspring are not recognizable + + align:start position:0% +children offspring are not recognizable + + + align:start position:0% +children offspring are not recognizable +very large dog this drop is not + + align:start position:0% +very large dog this drop is not + + + align:start position:0% +very large dog this drop is not +recapitulate recaptured in + + align:start position:0% +recapitulate recaptured in + + + align:start position:0% +recapitulate recaptured in +in this model in any any of the model if + + align:start position:0% +in this model in any any of the model if + + + align:start position:0% +in this model in any any of the model if +you have a deep network or you have one + + align:start position:0% +you have a deep network or you have one + + + align:start position:0% +you have a deep network or you have one +of these classifiers what is recognized + + align:start position:0% +of these classifiers what is recognized + + + align:start position:0% +of these classifiers what is recognized +and not recognized depend on the + + align:start position:0% +and not recognized depend on the + + + align:start position:0% +and not recognized depend on the +threshold you can decide that it gives + + align:start position:0% +threshold you can decide that it gives + + + align:start position:0% +threshold you can decide that it gives +you a number and it says that I have + + align:start position:0% +you a number and it says that I have + + + align:start position:0% +you a number and it says that I have +this and it's confident that this is + + align:start position:0% +this and it's confident that this is + + + align:start position:0% +this and it's confident that this is +belongs to the class so what we did here + + align:start position:0% +belongs to the class so what we did here + + + align:start position:0% +belongs to the class so what we did here +is that we try to match we had a class + + align:start position:0% +is that we try to match we had a class + + + align:start position:0% +is that we try to match we had a class +of images and people recognize them at + + align:start position:0% +of images and people recognize them at + + + align:start position:0% +of images and people recognize them at +80 percent recognition so we put the + + align:start position:0% +80 percent recognition so we put the + + + align:start position:0% +80 percent recognition so we put the +threshold in the artificial the computer + + align:start position:0% +threshold in the artificial the computer + + + align:start position:0% +threshold in the artificial the computer +vision system at such a level that it + + align:start position:0% +vision system at such a level that it + + + align:start position:0% +vision system at such a level that it +recognized correctly 80 percent of the + + align:start position:0% +recognized correctly 80 percent of the + + + align:start position:0% +recognized correctly 80 percent of the +of the of the minimal images so you + + align:start position:0% +of the of the minimal images so you + + + align:start position:0% +of the of the minimal images so you +match them and then we looked at how + + align:start position:0% +match them and then we looked at how + + + align:start position:0% +match them and then we looked at how +many of the sub images it passed the + + align:start position:0% +many of the sub images it passed the + + + align:start position:0% +many of the sub images it passed the +threshold and you get this is for bitmap + + align:start position:0% +threshold and you get this is for bitmap + + + align:start position:0% +threshold and you get this is for bitmap +that instead of a gap you actually got + + align:start position:0% +that instead of a gap you actually got + + + align:start position:0% +that instead of a gap you actually got +an up until gap it actually recognized a + + align:start position:0% +an up until gap it actually recognized a + + + align:start position:0% +an up until gap it actually recognized a +few more but this should not confuse you + + align:start position:0% +few more but this should not confuse you + + + align:start position:0% +few more but this should not confuse you +it does not mean that the deep network + + align:start position:0% +it does not mean that the deep network + + + align:start position:0% +it does not mean that the deep network +did better than humans it actually did + + align:start position:0% +did better than humans it actually did + + + align:start position:0% +did better than humans it actually did +much worse than humans although the bars + + align:start position:0% +much worse than humans although the bars + + + align:start position:0% +much worse than humans although the bars +here are higher and there is the + + align:start position:0% +here are higher and there is the + + + align:start position:0% +here are higher and there is the +following you can always even in very + + align:start position:0% +following you can always even in very + + + align:start position:0% +following you can always even in very +bad classifier you can get 80% + + align:start position:0% +bad classifier you can get 80% + + + align:start position:0% +bad classifier you can get 80% +recognition by just lowering the + + align:start position:0% +recognition by just lowering the + + + align:start position:0% +recognition by just lowering the +threshold and then 80 percent of the + + align:start position:0% +threshold and then 80 percent of the + + + align:start position:0% +threshold and then 80 percent of the +class examples will exceed the threshold + + align:start position:0% +class examples will exceed the threshold + + + align:start position:0% +class examples will exceed the threshold +the question is how many just garbage + + align:start position:0% +the question is how many just garbage + + + align:start position:0% +the question is how many just garbage +image non class images will also pass + + align:start position:0% +image non class images will also pass + + + align:start position:0% +image non class images will also pass +the threshold at the same time if you + + align:start position:0% +the threshold at the same time if you + + + align:start position:0% +the threshold at the same time if you +get 80 percent of the class but also + + align:start position:0% +get 80 percent of the class but also + + + align:start position:0% +get 80 percent of the class but also +lots and lots and lots of completely + + align:start position:0% +lots and lots and lots of completely + + + align:start position:0% +lots and lots and lots of completely +false positive negative images non class + + align:start position:0% +false positive negative images non class + + + align:start position:0% +false positive negative images non class +images are also saying I mean airplane + + align:start position:0% +images are also saying I mean airplane + + + align:start position:0% +images are also saying I mean airplane +then that's bad performance so just the + + align:start position:0% +then that's bad performance so just the + + + align:start position:0% +then that's bad performance so just the +these high bars do not say anything the + + align:start position:0% +these high bars do not say anything the + + + align:start position:0% +these high bars do not say anything the +the actual recognition levels will very + + align:start position:0% +the actual recognition levels will very + + + align:start position:0% +the actual recognition levels will very +low we can see here for deep networks + + align:start position:0% +low we can see here for deep networks + + + align:start position:0% +low we can see here for deep networks +that this high bar is the performance on + + align:start position:0% +that this high bar is the performance on + + + align:start position:0% +that this high bar is the performance on +new airplanes so for airplanes they did + + align:start position:0% +new airplanes so for airplanes they did + + + align:start position:0% +new airplanes so for airplanes they did +very well but the percent correct that + + align:start position:0% +very well but the percent correct that + + + align:start position:0% +very well but the percent correct that +he did on minimal images or 3% 4% very + + align:start position:0% +he did on minimal images or 3% 4% very + + + align:start position:0% +he did on minimal images or 3% 4% very +very + + align:start position:0% +very + + + align:start position:0% +very +very low so it did very bad recognition + + align:start position:0% +very low so it did very bad recognition + + + align:start position:0% +very low so it did very bad recognition +on the minimal on the minimal images so + + align:start position:0% +on the minimal on the minimal images so + + + align:start position:0% +on the minimal on the minimal images so +recognition of minimal image does not + + align:start position:0% +recognition of minimal image does not + + + align:start position:0% +recognition of minimal image does not +emerge by training any of the existing + + align:start position:0% +emerge by training any of the existing + + + align:start position:0% +emerge by training any of the existing +model that I know in in the world + + align:start position:0% +model that I know in in the world + + + align:start position:0% +model that I know in in the world +including not your deep network models + + align:start position:0% +including not your deep network models + + + align:start position:0% +including not your deep network models +now the tag the second test was as was + + align:start position:0% +now the tag the second test was as was + + + align:start position:0% +now the tag the second test was as was +asked here is that we we did another + + align:start position:0% +asked here is that we we did another + + + align:start position:0% +asked here is that we we did another +large test all of these things actually + + align:start position:0% +large test all of these things actually + + + align:start position:0% +large test all of these things actually +were a lot of effort and time consuming + + align:start position:0% +were a lot of effort and time consuming + + + align:start position:0% +were a lot of effort and time consuming +because now we have this this was in the + + align:start position:0% +because now we have this this was in the + + + align:start position:0% +because now we have this this was in the +original test was a minimal image I + + align:start position:0% +original test was a minimal image I + + + align:start position:0% +original test was a minimal image I +don't know this was a minimal image then + + align:start position:0% +don't know this was a minimal image then + + + align:start position:0% +don't know this was a minimal image then +we we collected a range of tales of + + align:start position:0% +we we collected a range of tales of + + + align:start position:0% +we we collected a range of tales of +planes like this for many other + + align:start position:0% +planes like this for many other + + + align:start position:0% +planes like this for many other +airplanes and we did run another Terk + + align:start position:0% + + + + align:start position:0% + +experiment which was pretty large + + align:start position:0% +experiment which was pretty large + + + align:start position:0% +experiment which was pretty large +because we wanted to verify that each + + align:start position:0% +because we wanted to verify that each + + + align:start position:0% +because we wanted to verify that each +one of these patches that we added to + + align:start position:0% +one of these patches that we added to + + + align:start position:0% +one of these patches that we added to +our test and we were going to use for + + align:start position:0% +our test and we were going to use for + + + align:start position:0% +our test and we were going to use for +testing recognition was indeed a minimal + + align:start position:0% +testing recognition was indeed a minimal + + + align:start position:0% +testing recognition was indeed a minimal +image from recognition so each one of + + align:start position:0% +image from recognition so each one of + + + align:start position:0% +image from recognition so each one of +these patches and there were 60 of those + + align:start position:0% +these patches and there were 60 of those + + + align:start position:0% +these patches and there were 60 of those +we ran on psychophysical II and we saw + + align:start position:0% +we ran on psychophysical II and we saw + + + align:start position:0% +we ran on psychophysical II and we saw +that it's recognizable and if you make + + align:start position:0% +that it's recognizable and if you make + + + align:start position:0% +that it's recognizable and if you make +it small if you try to reduce it it's + + align:start position:0% +it small if you try to reduce it it's + + + align:start position:0% +it small if you try to reduce it it's +unrecognizable so each one of these is + + align:start position:0% +unrecognizable so each one of these is + + + align:start position:0% +unrecognizable so each one of these is +individually also a minimal image so + + align:start position:0% +individually also a minimal image so + + + align:start position:0% +individually also a minimal image so +here we did training and testing on so + + align:start position:0% +here we did training and testing on so + + + align:start position:0% +here we did training and testing on so +this is some examples of this so here + + align:start position:0% +this is some examples of this so here + + + align:start position:0% +this is some examples of this so here +various images of fly and each one of + + align:start position:0% +various images of fly and each one of + + + align:start position:0% +various images of fly and each one of +them was tested on 30 subject on the + + align:start position:0% +them was tested on 30 subject on the + + + align:start position:0% +them was tested on 30 subject on the +Mechanical Turk and the results that in + + align:start position:0% +Mechanical Turk and the results that in + + + align:start position:0% +Mechanical Turk and the results that in +terms of correct recognition there is a + + align:start position:0% +terms of correct recognition there is a + + + align:start position:0% +terms of correct recognition there is a +substantial improvement from 3 percent + + align:start position:0% +substantial improvement from 3 percent + + + align:start position:0% +substantial improvement from 3 percent +to 60 percent but 60 percent is not very + + align:start position:0% +to 60 percent but 60 percent is not very + + + align:start position:0% +to 60 percent but 60 percent is not very +large people recognize them 60 I should + + align:start position:0% +large people recognize them 60 I should + + + align:start position:0% +large people recognize them 60 I should +say you should look at the false alarm + + align:start position:0% +say you should look at the false alarm + + + align:start position:0% +say you should look at the false alarm +the number of arrows we'll show you + + align:start position:0% +the number of arrows we'll show you + + + align:start position:0% +the number of arrows we'll show you +later the number of arrows that even + + align:start position:0% +later the number of arrows that even + + + align:start position:0% +later the number of arrows that even +after training on minimal images the + + align:start position:0% +after training on minimal images the + + + align:start position:0% +after training on minimal images the +number of the performance of the deep + + align:start position:0% +number of the performance of the deep + + + align:start position:0% +number of the performance of the deep +network and all the other models on the + + align:start position:0% +network and all the other models on the + + + align:start position:0% +network and all the other models on the +minimum image + + align:start position:0% +minimum image + + + align:start position:0% +minimum image +is far worse than human recognition + + align:start position:0% +is far worse than human recognition + + + align:start position:0% +is far worse than human recognition +level human performance on the same + + align:start position:0% +level human performance on the same + + + align:start position:0% +level human performance on the same +images so it's not just the the gap is + + align:start position:0% +images so it's not just the the gap is + + + align:start position:0% +images so it's not just the the gap is +not reproduce even training with minimal + + align:start position:0% +not reproduce even training with minimal + + + align:start position:0% +not reproduce even training with minimal +images the performance is not is not + + align:start position:0% +images the performance is not is not + + + align:start position:0% +images the performance is not is not +reproduced the arrows or the accuracy is + + align:start position:0% +reproduced the arrows or the accuracy is + + + align:start position:0% +reproduced the arrows or the accuracy is +far worse in the in all the models + + align:start position:0% +far worse in the in all the models + + + align:start position:0% +far worse in the in all the models +including deep network compared to to + + align:start position:0% +including deep network compared to to + + + align:start position:0% +including deep network compared to to +human vision so these systems do not do + + align:start position:0% +human vision so these systems do not do + + + align:start position:0% +human vision so these systems do not do +it it remains to be you can always ask + + align:start position:0% +it it remains to be you can always ask + + + align:start position:0% +it it remains to be you can always ask +what happened if I train it with a + + align:start position:0% +what happened if I train it with a + + + align:start position:0% +what happened if I train it with a +hundred thousand images and I add an add + + align:start position:0% +hundred thousand images and I add an add + + + align:start position:0% +hundred thousand images and I add an add +more and more example this we couldn't + + align:start position:0% +more and more example this we couldn't + + + align:start position:0% +more and more example this we couldn't +this becomes more and larger but my with + + align:start position:0% +this becomes more and larger but my with + + + align:start position:0% +this becomes more and larger but my with +the experiment we've done which are + + align:start position:0% +the experiment we've done which are + + + align:start position:0% +the experiment we've done which are +quite extensive it does not a poet does + + align:start position:0% +quite extensive it does not a poet does + + + align:start position:0% +quite extensive it does not a poet does +not begin to approach human accuracy + + align:start position:0% +not begin to approach human accuracy + + + align:start position:0% +not begin to approach human accuracy +humans are much are much better and I'll + + align:start position:0% +humans are much are much better and I'll + + + align:start position:0% +humans are much are much better and I'll +show you I think it's not just the + + align:start position:0% +show you I think it's not just the + + + align:start position:0% +show you I think it's not just the +competition who does who does better I + + align:start position:0% +competition who does who does better I + + + align:start position:0% +competition who does who does better I +think there is something deeper there + + align:start position:0% +think there is something deeper there + + + align:start position:0% +think there is something deeper there +and that's what I want to go next let me + + align:start position:0% +and that's what I want to go next let me + + + align:start position:0% +and that's what I want to go next let me +skip some these are the arrow comparison + + align:start position:0% +skip some these are the arrow comparison + + + align:start position:0% +skip some these are the arrow comparison +and you can see it just to show in a lot + + align:start position:0% +and you can see it just to show in a lot + + + align:start position:0% +and you can see it just to show in a lot +of different examples zero zero arrows + + align:start position:0% +of different examples zero zero arrows + + + align:start position:0% +of different examples zero zero arrows +for humans 17% in the deep networks and + + align:start position:0% +for humans 17% in the deep networks and + + + align:start position:0% +for humans 17% in the deep networks and +so on so that's big big differences ok + + align:start position:0% +so on so that's big big differences ok + + + align:start position:0% +so on so that's big big differences ok +the related thing which I think gets to + + align:start position:0% +the related thing which I think gets to + + + align:start position:0% +the related thing which I think gets to +the heart of what's going on that humans + + align:start position:0% +the heart of what's going on that humans + + + align:start position:0% +the heart of what's going on that humans +can do with these minimal images and + + align:start position:0% +can do with these minimal images and + + + align:start position:0% +can do with these minimal images and +model at the moment cannot is that we do + + align:start position:0% +model at the moment cannot is that we do + + + align:start position:0% +model at the moment cannot is that we do +not only do not only recognize this + + align:start position:0% +not only do not only recognize this + + + align:start position:0% +not only do not only recognize this +image and say this is a man this is an + + align:start position:0% +image and say this is a man this is an + + + align:start position:0% +image and say this is a man this is an +eagle this is the horse once we + + align:start position:0% +eagle this is the horse once we + + + align:start position:0% +eagle this is the horse once we +recognize it although the image itself + + align:start position:0% +recognize it although the image itself + + + align:start position:0% +recognize it although the image itself +is sort of atomic in the sense that you + + align:start position:0% +is sort of atomic in the sense that you + + + align:start position:0% +is sort of atomic in the sense that you +would use it and the cognition goes away + + align:start position:0% +would use it and the cognition goes away + + + align:start position:0% +would use it and the cognition goes away +but once you recognize it we can + + align:start position:0% +but once you recognize it we can + + + align:start position:0% +but once you recognize it we can +recognize sort of subatomic particles we + + align:start position:0% +recognize sort of subatomic particles we + + + align:start position:0% +recognize sort of subatomic particles we +can recognize things inside it so if + + align:start position:0% +can recognize things inside it so if + + + align:start position:0% +can recognize things inside it so if +this is a person we asked again in a + + align:start position:0% +this is a person we asked again in a + + + align:start position:0% +this is a person we asked again in a +psycho physical test to tell us what you + + align:start position:0% +psycho physical test to tell us what you + + + align:start position:0% +psycho physical test to tell us what you +see + + align:start position:0% +see + + + align:start position:0% +see +inside the image in various using + + align:start position:0% +inside the image in various using + + + align:start position:0% +inside the image in various using +various methodologies which I'll not go + + align:start position:0% +various methodologies which I'll not go + + + align:start position:0% +various methodologies which I'll not go +into but people recognize this this is a + + align:start position:0% +into but people recognize this this is a + + + align:start position:0% +into but people recognize this this is a +person in Italian suit for those of you + + align:start position:0% +person in Italian suit for those of you + + + align:start position:0% +person in Italian suit for those of you +could not recognize it but once people + + align:start position:0% +could not recognize it but once people + + + align:start position:0% +could not recognize it but once people +recognize it they say this is the neck + + align:start position:0% +recognize it they say this is the neck + + + align:start position:0% +recognize it they say this is the neck +of the person this is the tie this is + + align:start position:0% +of the person this is the tie this is + + + align:start position:0% +of the person this is the tie this is +the this is the knot of the tie this is + + align:start position:0% +the this is the knot of the tie this is + + + align:start position:0% +the this is the knot of the tie this is +part of the jacket and so on and so + + align:start position:0% +part of the jacket and so on and so + + + align:start position:0% +part of the jacket and so on and so +forth I mean they recognize a whole lot + + align:start position:0% +forth I mean they recognize a whole lot + + + align:start position:0% +forth I mean they recognize a whole lot +of details semantic internal details + + align:start position:0% +of details semantic internal details + + + align:start position:0% +of details semantic internal details +inside if they see this is the horse so + + align:start position:0% +inside if they see this is the horse so + + + align:start position:0% +inside if they see this is the horse so +in the contrast is low but they see the + + align:start position:0% +in the contrast is low but they see the + + + align:start position:0% +in the contrast is low but they see the +ear and the other in the eye and the + + align:start position:0% +ear and the other in the eye and the + + + align:start position:0% +ear and the other in the eye and the +mouse but if you reduce the image they + + align:start position:0% +mouse but if you reduce the image they + + + align:start position:0% +mouse but if you reduce the image they +lose the recognition completely once you + + align:start position:0% +lose the recognition completely once you + + + align:start position:0% +lose the recognition completely once you +recognize it they recognize a whole lot + + align:start position:0% +recognize it they recognize a whole lot + + + align:start position:0% +recognize it they recognize a whole lot +of structure inside and I think that the + + align:start position:0% +of structure inside and I think that the + + + align:start position:0% +of structure inside and I think that the +structure by itself is the more + + align:start position:0% +structure by itself is the more + + + align:start position:0% +structure by itself is the more +interesting part because when we we + + align:start position:0% +interesting part because when we we + + + align:start position:0% +interesting part because when we we +don't want to say a horse we don't want + + align:start position:0% +don't want to say a horse we don't want + + + align:start position:0% +don't want to say a horse we don't want +to see a car we want to know where the + + align:start position:0% +to see a car we want to know where the + + + align:start position:0% +to see a car we want to know where the +car door where the knob is we want to + + align:start position:0% +car door where the knob is we want to + + + align:start position:0% +car door where the knob is we want to +recognize all the internal details but + + align:start position:0% +recognize all the internal details but + + + align:start position:0% +recognize all the internal details but +the ability to recognize all of these + + align:start position:0% +the ability to recognize all of these + + + align:start position:0% +the ability to recognize all of these +internal details is automatically it's + + align:start position:0% +internal details is automatically it's + + + align:start position:0% +internal details is automatically it's +also helping you with improving the + + align:start position:0% +also helping you with improving the + + + align:start position:0% +also helping you with improving the +recognition and rejecting sort of false + + align:start position:0% +recognition and rejecting sort of false + + + align:start position:0% +recognition and rejecting sort of false +detections because these are images the + + align:start position:0% +detections because these are images the + + + align:start position:0% +detections because these are images the +deep network thought that are good + + align:start position:0% +deep network thought that are good + + + align:start position:0% +deep network thought that are good +images of a man in a suit but once you + + align:start position:0% +images of a man in a suit but once you + + + align:start position:0% +images of a man in a suit but once you +dive inside and you say where exactly is + + align:start position:0% +dive inside and you say where exactly is + + + align:start position:0% +dive inside and you say where exactly is +the neck and where exactly is the tie + + align:start position:0% +the neck and where exactly is the tie + + + align:start position:0% +the neck and where exactly is the tie +and is it the right structure that I + + align:start position:0% +and is it the right structure that I + + + align:start position:0% +and is it the right structure that I +expect the answer is that it's not quite + + align:start position:0% +expect the answer is that it's not quite + + + align:start position:0% +expect the answer is that it's not quite +appropriate and you can use that so that + + align:start position:0% +appropriate and you can use that so that + + + align:start position:0% +appropriate and you can use that so that +this internal interpretation is first of + + align:start position:0% +this internal interpretation is first of + + + align:start position:0% +this internal interpretation is first of +all the more important goal of vision + + align:start position:0% +all the more important goal of vision + + + align:start position:0% +all the more important goal of vision +but in addition once you do it you can + + align:start position:0% +but in addition once you do it you can + + + align:start position:0% +but in addition once you do it you can +reject things that appeared based on the + + align:start position:0% +reject things that appeared based on the + + + align:start position:0% +reject things that appeared based on the +causal structure to be correct and in + + align:start position:0% +causal structure to be correct and in + + + align:start position:0% +causal structure to be correct and in +this in this way you can get the correct + + align:start position:0% +this in this way you can get the correct + + + align:start position:0% +this in this way you can get the correct +recognition and in this for this reason + + align:start position:0% +recognition and in this for this reason + + + align:start position:0% +recognition and in this for this reason +my prediction is that it would be very + + align:start position:0% +my prediction is that it would be very + + + align:start position:0% +my prediction is that it would be very +difficult to get it with current deep + + align:start position:0% +difficult to get it with current deep + + + align:start position:0% +difficult to get it with current deep +network because what you need is not + + align:start position:0% +network because what you need is not + + + align:start position:0% +network because what you need is not +only to get the label out but to be able + + align:start position:0% +only to get the label out but to be able + + + align:start position:0% +only to get the label out but to be able +to dive down and get the correct + + align:start position:0% +to dive down and get the correct + + + align:start position:0% +to dive down and get the correct +interpretation and inspect it and it has + + align:start position:0% +interpretation and inspect it and it has + + + align:start position:0% +interpretation and inspect it and it has +some property is what the pie + + align:start position:0% +some property is what the pie + + + align:start position:0% +some property is what the pie +the knot in the tie is slightly wider + + align:start position:0% +the knot in the tie is slightly wider + + + align:start position:0% +the knot in the tie is slightly wider +than the part under it and so on so you + + align:start position:0% +than the part under it and so on so you + + + align:start position:0% +than the part under it and so on so you +have to check for the you know these + + align:start position:0% +have to check for the you know these + + + align:start position:0% +have to check for the you know these +things and you check for them and if you + + align:start position:0% +things and you check for them and if you + + + align:start position:0% +things and you check for them and if you +don't do it then the recognition will + + align:start position:0% +don't do it then the recognition will + + + align:start position:0% +don't do it then the recognition will +remain remain limited now when you look + + align:start position:0% +remain remain limited now when you look + + + align:start position:0% +remain remain limited now when you look +at it and you say okay and we try to + + align:start position:0% +at it and you say okay and we try to + + + align:start position:0% +at it and you say okay and we try to +develop algorithm which will actually + + align:start position:0% +develop algorithm which will actually + + + align:start position:0% +develop algorithm which will actually +dive in and we'll do the interval + + align:start position:0% +dive in and we'll do the interval + + + align:start position:0% +dive in and we'll do the interval +internal interpretation and we'll do + + align:start position:0% +internal interpretation and we'll do + + + align:start position:0% +internal interpretation and we'll do +them correctly and we'll reject false + + align:start position:0% +them correctly and we'll reject false + + + align:start position:0% +them correctly and we'll reject false +and false alarms and so on it turns out + + align:start position:0% +and false alarms and so on it turns out + + + align:start position:0% +and false alarms and so on it turns out +that this is an interesting business you + + align:start position:0% +that this is an interesting business you + + + align:start position:0% +that this is an interesting business you +have to be very accurate and some of the + + align:start position:0% +have to be very accurate and some of the + + + align:start position:0% +have to be very accurate and some of the +properties and relations that you need + + align:start position:0% +properties and relations that you need + + + align:start position:0% +properties and relations that you need +to extract are very specific to certain + + align:start position:0% +to extract are very specific to certain + + + align:start position:0% +to extract are very specific to certain +categories and are very precise for + + align:start position:0% +categories and are very precise for + + + align:start position:0% +categories and are very precise for +example this was selected by deep + + align:start position:0% +example this was selected by deep + + + align:start position:0% +example this was selected by deep +Network is a very good example of a + + align:start position:0% +Network is a very good example of a + + + align:start position:0% +Network is a very good example of a +horse head and it's basically the right + + align:start position:0% +horse head and it's basically the right + + + align:start position:0% +horse head and it's basically the right +it does have the right shape but for + + align:start position:0% +it does have the right shape but for + + + align:start position:0% +it does have the right shape but for +example people reject it we ask as + + align:start position:0% +example people reject it we ask as + + + align:start position:0% +example people reject it we ask as +people did not accept it as a horse head + + align:start position:0% +people did not accept it as a horse head + + + align:start position:0% +people did not accept it as a horse head +and they said for example the dis lines + + align:start position:0% +and they said for example the dis lines + + + align:start position:0% +and they said for example the dis lines +are too straight it looks like a + + align:start position:0% +are too straight it looks like a + + + align:start position:0% +are too straight it looks like a +man-made palate rather than a part of a + + align:start position:0% +man-made palate rather than a part of a + + + align:start position:0% +man-made palate rather than a part of a +wheel of a real animal that that was a + + align:start position:0% +wheel of a real animal that that was a + + + align:start position:0% +wheel of a real animal that that was a +repeating answer for example but the + + align:start position:0% +repeating answer for example but the + + + align:start position:0% +repeating answer for example but the +creation how straight is it and so on + + align:start position:0% +creation how straight is it and so on + + + align:start position:0% +creation how straight is it and so on +this is a bit tricky and also it didn't + + align:start position:0% +this is a bit tricky and also it didn't + + + align:start position:0% +this is a bit tricky and also it didn't +have quite the ear that you do expect + + align:start position:0% +have quite the ear that you do expect + + + align:start position:0% +have quite the ear that you do expect +here so we think that the kind of + + align:start position:0% +here so we think that the kind of + + + align:start position:0% +here so we think that the kind of +feature that you need in order to do + + align:start position:0% +feature that you need in order to do + + + align:start position:0% +feature that you need in order to do +this internal interpretation of interest + + align:start position:0% +this internal interpretation of interest + + + align:start position:0% +this internal interpretation of interest +depends on relatively complicated + + align:start position:0% +depends on relatively complicated + + + align:start position:0% +depends on relatively complicated +properties and relations that you don't + + align:start position:0% +properties and relations that you don't + + + align:start position:0% +properties and relations that you don't +want to spend time and effort doing in a + + align:start position:0% +want to spend time and effort doing in a + + + align:start position:0% +want to spend time and effort doing in a +bottom-up way all over the all over the + + align:start position:0% +bottom-up way all over the all over the + + + align:start position:0% +bottom-up way all over the all over the +the entire visual field if certain two + + align:start position:0% +the entire visual field if certain two + + + align:start position:0% +the entire visual field if certain two +contours move smoothly or in a corner or + + align:start position:0% +contours move smoothly or in a corner or + + + align:start position:0% +contours move smoothly or in a corner or +if something is really straight only + + align:start position:0% +if something is really straight only + + + align:start position:0% +if something is really straight only +semi straight I mean to do all of these + + align:start position:0% +semi straight I mean to do all of these + + + align:start position:0% +semi straight I mean to do all of these +computations my subject my hunch is to + + align:start position:0% +computations my subject my hunch is to + + + align:start position:0% +computations my subject my hunch is to +do all of these complicated things you + + align:start position:0% +do all of these complicated things you + + + align:start position:0% +do all of these complicated things you +need them only in a small you need some + + align:start position:0% +need them only in a small you need some + + + align:start position:0% +need them only in a small you need some +specific ones for some specific classes + + align:start position:0% +specific ones for some specific classes + + + align:start position:0% +specific ones for some specific classes +at some specific locations so the right + + align:start position:0% +at some specific locations so the right + + + align:start position:0% +at some specific locations so the right +way to do to do this kind of computation + + align:start position:0% +way to do to do this kind of computation + + + align:start position:0% +way to do to do this kind of computation +the right architecture seems to me a + + align:start position:0% +the right architecture seems to me a + + + align:start position:0% +the right architecture seems to me a +combination of bottom-up and top-down + + align:start position:0% +combination of bottom-up and top-down + + + align:start position:0% +combination of bottom-up and top-down +processing and we know that in the + + align:start position:0% +processing and we know that in the + + + align:start position:0% +processing and we know that in the +visual system this is a diagram of the + + align:start position:0% +visual system this is a diagram of the + + + align:start position:0% +visual system this is a diagram of the +system which is supposed supposed to + + align:start position:0% +system which is supposed supposed to + + + align:start position:0% +system which is supposed supposed to +show that we have lots of connections + + align:start position:0% +show that we have lots of connections + + + align:start position:0% +show that we have lots of connections +going up but also a lot of connections + + align:start position:0% +going up but also a lot of connections + + + align:start position:0% +going up but also a lot of connections +going down and it's suggestion that I + + align:start position:0% +going down and it's suggestion that I + + + align:start position:0% +going down and it's suggestion that I +would like to put up and I think it's + + align:start position:0% +would like to put up and I think it's + + + align:start position:0% +would like to put up and I think it's +what's happening here is that we have + + align:start position:0% +what's happening here is that we have + + + align:start position:0% +what's happening here is that we have +something like deep network that does an + + align:start position:0% +something like deep network that does an + + + align:start position:0% +something like deep network that does an +initial generic classification it's + + align:start position:0% +initial generic classification it's + + + align:start position:0% +initial generic classification it's +bottom-up it has some kind of was + + align:start position:0% +bottom-up it has some kind of was + + + align:start position:0% +bottom-up it has some kind of was +trained on many categories it is not + + align:start position:0% +trained on many categories it is not + + + align:start position:0% +trained on many categories it is not +sensitive to all of this small and + + align:start position:0% +sensitive to all of this small and + + + align:start position:0% +sensitive to all of this small and +informative things that you need for + + align:start position:0% +informative things that you need for + + + align:start position:0% +informative things that you need for +internal classification and it proposes + + align:start position:0% +internal classification and it proposes + + + align:start position:0% +internal classification and it proposes +a lot of it gives you initialize initial + + align:start position:0% +a lot of it gives you initialize initial + + + align:start position:0% +a lot of it gives you initialize initial +recognition which is OK + + align:start position:0% +recognition which is OK + + + align:start position:0% +recognition which is OK +it's especially ok when you have a + + align:start position:0% +it's especially ok when you have a + + + align:start position:0% +it's especially ok when you have a +complete object and not something + + align:start position:0% +complete object and not something + + + align:start position:0% +complete object and not something +challenging like it's like a minimal + + align:start position:0% +challenging like it's like a minimal + + + align:start position:0% +challenging like it's like a minimal +image because you may be wrong on a + + align:start position:0% +image because you may be wrong on a + + + align:start position:0% +image because you may be wrong on a +couple of the minimal images but you + + align:start position:0% +couple of the minimal images but you + + + align:start position:0% +couple of the minimal images but you +have 20 of them in each object so 2 are + + align:start position:0% +have 20 of them in each object so 2 are + + + align:start position:0% +have 20 of them in each object so 2 are +wrong it's not too bad so under many + + align:start position:0% +wrong it's not too bad so under many + + + align:start position:0% +wrong it's not too bad so under many +circumstances you'll be okay in terms of + + align:start position:0% +circumstances you'll be okay in terms of + + + align:start position:0% +circumstances you'll be okay in terms of +general general recognition but what + + align:start position:0% +general general recognition but what + + + align:start position:0% +general general recognition but what +this does is it doesn't complete the + + align:start position:0% +this does is it doesn't complete the + + + align:start position:0% +this does is it doesn't complete the +process but it sort of triggers the + + align:start position:0% +process but it sort of triggers the + + + align:start position:0% +process but it sort of triggers the +application of something which is much + + align:start position:0% +application of something which is much + + + align:start position:0% +application of something which is much +more class specific that it says oh it + + align:start position:0% +more class specific that it says oh it + + + align:start position:0% +more class specific that it says oh it +looks like a horse let's check if it has + + align:start position:0% +looks like a horse let's check if it has + + + align:start position:0% +looks like a horse let's check if it has +so let's now complete the interpretation + + align:start position:0% +so let's now complete the interpretation + + + align:start position:0% +so let's now complete the interpretation +it's not just a validation but you + + align:start position:0% +it's not just a validation but you + + + align:start position:0% +it's not just a validation but you +really want to know where is the eye + + align:start position:0% +really want to know where is the eye + + + align:start position:0% +really want to know where is the eye +where is the ear where is the mouse and + + align:start position:0% +where is the ear where is the mouse and + + + align:start position:0% +where is the ear where is the mouse and +so on you want to know maybe if the + + align:start position:0% +so on you want to know maybe if the + + + align:start position:0% +so on you want to know maybe if the +mouse is open or closed you want to feed + + align:start position:0% +mouse is open or closed you want to feed + + + align:start position:0% +mouse is open or closed you want to feed +the horse you want to pet the horse I + + align:start position:0% +the horse you want to pet the horse I + + + align:start position:0% +the horse you want to pet the horse I +mean when you interact with object all + + align:start position:0% +mean when you interact with object all + + + align:start position:0% +mean when you interact with object all +of these things are important so you + + align:start position:0% +of these things are important so you + + + align:start position:0% +of these things are important so you +continue your understanding of the + + align:start position:0% +continue your understanding of the + + + align:start position:0% +continue your understanding of the +visual scene but this is not this + + align:start position:0% +visual scene but this is not this + + + align:start position:0% +visual scene but this is not this +generic bottom-up recognition but you + + align:start position:0% +generic bottom-up recognition but you + + + align:start position:0% +generic bottom-up recognition but you +are looking for specific structures that + + align:start position:0% +are looking for specific structures that + + + align:start position:0% +are looking for specific structures that +you you learned about when you interact + + align:start position:0% +you you learned about when you interact + + + align:start position:0% +you you learned about when you interact +with these objects before and then you + + align:start position:0% +with these objects before and then you + + + align:start position:0% +with these objects before and then you +test specific things I mean where is the + + align:start position:0% +test specific things I mean where is the + + + align:start position:0% +test specific things I mean where is the +eye this should be a round thing roughly + + align:start position:0% +eye this should be a round thing roughly + + + align:start position:0% +eye this should be a round thing roughly +here and so on and so forth so these are + + align:start position:0% +here and so on and so forth so these are + + + align:start position:0% +here and so on and so forth so these are +more extended routines that you're + + align:start position:0% +more extended routines that you're + + + align:start position:0% +more extended routines that you're +applying to the to the detected to the + + align:start position:0% +applying to the to the detected to the + + + align:start position:0% +applying to the to the detected to the +detected region sort of directed from + + align:start position:0% +detected region sort of directed from + + + align:start position:0% +detected region sort of directed from +above and you know what kind of feature + + align:start position:0% +above and you know what kind of feature + + + align:start position:0% +above and you know what kind of feature +to + + align:start position:0% +to + + + align:start position:0% +to +to look for at different locations with + + align:start position:0% +to look for at different locations with + + + align:start position:0% +to look for at different locations with +India within the minimal image and this + + align:start position:0% +India within the minimal image and this + + + align:start position:0% +India within the minimal image and this +kind of ongoing continuing + + align:start position:0% +kind of ongoing continuing + + + align:start position:0% +kind of ongoing continuing +interpretation is not just inside + + align:start position:0% +interpretation is not just inside + + + align:start position:0% +interpretation is not just inside +internally to the what you succeeded to + + align:start position:0% +internally to the what you succeeded to + + + align:start position:0% +internally to the what you succeeded to +recognize but start to spread over the + + align:start position:0% +recognize but start to spread over the + + + align:start position:0% +recognize but start to spread over the +entire image for example if you look at + + align:start position:0% +entire image for example if you look at + + + align:start position:0% +entire image for example if you look at +this image what do you see here in this + + align:start position:0% +this image what do you see here in this + + + align:start position:0% +this image what do you see here in this +image here anyone want to suggest what + + align:start position:0% +image here anyone want to suggest what + + + align:start position:0% +image here anyone want to suggest what +we see here sorry + + align:start position:0% +we see here sorry + + + align:start position:0% +we see here sorry +women's face what is it one doing + + align:start position:0% +women's face what is it one doing + + + align:start position:0% +women's face what is it one doing +drinking right so it's a woman drinking + + align:start position:0% +drinking right so it's a woman drinking + + + align:start position:0% +drinking right so it's a woman drinking +for those of you managed to recognize + + align:start position:0% +for those of you managed to recognize + + + align:start position:0% +for those of you managed to recognize +this is the woman she's drinking for + + align:start position:0% +this is the woman she's drinking for + + + align:start position:0% +this is the woman she's drinking for +from a cup but we tested e the woman is + + align:start position:0% +from a cup but we tested e the woman is + + + align:start position:0% +from a cup but we tested e the woman is +actually a minimal image it's if you + + align:start position:0% +actually a minimal image it's if you + + + align:start position:0% +actually a minimal image it's if you +remove the cup you show this image + + align:start position:0% +remove the cup you show this image + + + align:start position:0% +remove the cup you show this image +people recognize it at relatively high + + align:start position:0% +people recognize it at relatively high + + + align:start position:0% +people recognize it at relatively high +nobody you recognize this is a glass + + align:start position:0% +nobody you recognize this is a glass + + + align:start position:0% +nobody you recognize this is a glass +when you when you just show the glass on + + align:start position:0% +when you when you just show the glass on + + + align:start position:0% +when you when you just show the glass on +its own we think that you started actual + + align:start position:0% +its own we think that you started actual + + + align:start position:0% +its own we think that you started actual +recognition process in your head starts + + align:start position:0% +recognition process in your head starts + + + align:start position:0% +recognition process in your head starts +with recognizing the what is + + align:start position:0% +with recognizing the what is + + + align:start position:0% +with recognizing the what is +recognizable on its own sort of the + + align:start position:0% +recognizable on its own sort of the + + + align:start position:0% +recognizable on its own sort of the +minimal configuration but you know what + + align:start position:0% +minimal configuration but you know what + + + align:start position:0% +minimal configuration but you know what +it is you don't need help you don't need + + align:start position:0% +it is you don't need help you don't need + + + align:start position:0% +it is you don't need help you don't need +contact you don't need anything this is + + align:start position:0% +contact you don't need anything this is + + + align:start position:0% +contact you don't need anything this is +a woman this is the mouse and you can + + align:start position:0% +a woman this is the mouse and you can + + + align:start position:0% +a woman this is the mouse and you can +continue from there in the same way that + + align:start position:0% +continue from there in the same way that + + + align:start position:0% +continue from there in the same way that +you can recognize internally that this + + align:start position:0% +you can recognize internally that this + + + align:start position:0% +you can recognize internally that this +is the this is the nose and the nostril + + align:start position:0% +is the this is the nose and the nostril + + + align:start position:0% +is the this is the nose and the nostril +and this is the upper lip and lower lip + + align:start position:0% +and this is the upper lip and lower lip + + + align:start position:0% +and this is the upper lip and lower lip +you can in the same way that you can + + align:start position:0% +you can in the same way that you can + + + align:start position:0% +you can in the same way that you can +guide your interpretation process + + align:start position:0% +guide your interpretation process + + + align:start position:0% +guide your interpretation process +internally you can also say that the + + align:start position:0% +internally you can also say that the + + + align:start position:0% +internally you can also say that the +thing which is docked at her mouth is is + + align:start position:0% +thing which is docked at her mouth is is + + + align:start position:0% +thing which is docked at her mouth is is +a glass some results from this is has + + align:start position:0% +a glass some results from this is has + + + align:start position:0% +a glass some results from this is has +been implemented by guide when yourself + + align:start position:0% +been implemented by guide when yourself + + + align:start position:0% +been implemented by guide when yourself +who is also now a part of CBM and this + + align:start position:0% +who is also now a part of CBM and this + + + align:start position:0% +who is also now a part of CBM and this +internal interpretation begins to work + + align:start position:0% +internal interpretation begins to work + + + align:start position:0% +internal interpretation begins to work +interestingly where we started to do it + + align:start position:0% +interestingly where we started to do it + + + align:start position:0% +interestingly where we started to do it +MIT some Meg studies because if this is + + align:start position:0% +MIT some Meg studies because if this is + + + align:start position:0% +MIT some Meg studies because if this is +correct if the interpretation process in + + align:start position:0% +correct if the interpretation process in + + + align:start position:0% +correct if the interpretation process in +the correct recognition of minimal + + align:start position:0% +the correct recognition of minimal + + + align:start position:0% +the correct recognition of minimal +images and the following full + + align:start position:0% +images and the following full + + + align:start position:0% +images and the following full +interpretation process is driven by its + + align:start position:0% +interpretation process is driven by its + + + align:start position:0% +interpretation process is driven by its +requires for completion it requires the + + align:start position:0% +requires for completion it requires the + + + align:start position:0% +requires for completion it requires the +triggering of top-down processing that + + align:start position:0% +triggering of top-down processing that + + + align:start position:0% +triggering of top-down processing that +we could see it in using the right kind + + align:start position:0% +we could see it in using the right kind + + + align:start position:0% +we could see it in using the right kind +of imaging in this case the + + align:start position:0% +of imaging in this case the + + + align:start position:0% +of imaging in this case the +we started to do minimal images in meg + + align:start position:0% +we started to do minimal images in meg + + + align:start position:0% +we started to do minimal images in meg +Meg images with Meg is I think you was + + align:start position:0% +Meg images with Meg is I think you was + + + align:start position:0% +Meg images with Meg is I think you was +make already mentioned here and if the + + align:start position:0% +make already mentioned here and if the + + + align:start position:0% +make already mentioned here and if the +talk so Meg as you know it doesn't have + + align:start position:0% +talk so Meg as you know it doesn't have + + + align:start position:0% +talk so Meg as you know it doesn't have +very good spatial resolution it's not + + align:start position:0% +very good spatial resolution it's not + + + align:start position:0% +very good spatial resolution it's not +like fMRI but it has very good temporal + + align:start position:0% +like fMRI but it has very good temporal + + + align:start position:0% +like fMRI but it has very good temporal +resolution and what Lila was I was led + + align:start position:0% +resolution and what Lila was I was led + + + align:start position:0% +resolution and what Lila was I was led +by by Leila Isaac and what we've done + + align:start position:0% +by by Leila Isaac and what we've done + + + align:start position:0% +by by Leila Isaac and what we've done +here is trying to let subject in the Meg + + align:start position:0% +here is trying to let subject in the Meg + + + align:start position:0% +here is trying to let subject in the Meg +recognize minimal images and we took the + + align:start position:0% +recognize minimal images and we took the + + + align:start position:0% +recognize minimal images and we took the +electrodes from the meg and trained a + + align:start position:0% +electrodes from the meg and trained a + + + align:start position:0% +electrodes from the meg and trained a +decoder the decoder is trained to say + + align:start position:0% +decoder the decoder is trained to say + + + align:start position:0% +decoder the decoder is trained to say +whether or not the image contains say an + + align:start position:0% +whether or not the image contains say an + + + align:start position:0% +whether or not the image contains say an +eagle in this case and we had various + + align:start position:0% +eagle in this case and we had various + + + align:start position:0% +eagle in this case and we had various +images and the question is we can follow + + align:start position:0% +images and the question is we can follow + + + align:start position:0% +images and the question is we can follow +the performance of the computational + + align:start position:0% +the performance of the computational + + + align:start position:0% +the performance of the computational +decoder they tries to say now the image + + align:start position:0% +decoder they tries to say now the image + + + align:start position:0% +decoder they tries to say now the image +now the electrode the pattern of + + align:start position:0% +now the electrode the pattern of + + + align:start position:0% +now the electrode the pattern of +electrodes allow me to deduce that there + + align:start position:0% +electrodes allow me to deduce that there + + + align:start position:0% +electrodes allow me to deduce that there +is an eagle in there in the image and we + + align:start position:0% +is an eagle in there in the image and we + + + align:start position:0% +is an eagle in there in the image and we +see that the decoder is successful you + + align:start position:0% +see that the decoder is successful you + + + align:start position:0% +see that the decoder is successful you +can see about 400 milliseconds this is + + align:start position:0% +can see about 400 milliseconds this is + + + align:start position:0% +can see about 400 milliseconds this is +late for vision the initial bottom-up + + align:start position:0% +late for vision the initial bottom-up + + + align:start position:0% +late for vision the initial bottom-up +initial recognition is more like a + + align:start position:0% +initial recognition is more like a + + + align:start position:0% +initial recognition is more like a +hundred and fifty or something like this + + align:start position:0% +hundred and fifty or something like this + + + align:start position:0% +hundred and fifty or something like this +and we also get the same results when we + + align:start position:0% +and we also get the same results when we + + + align:start position:0% +and we also get the same results when we +do psychophysics that in normal images + + align:start position:0% +do psychophysics that in normal images + + + align:start position:0% +do psychophysics that in normal images +you can recognize them you can get good + + align:start position:0% +you can recognize them you can get good + + + align:start position:0% +you can recognize them you can get good +recognition after exposure of 100 + + align:start position:0% +recognition after exposure of 100 + + + align:start position:0% +recognition after exposure of 100 +milliseconds followed by a mask in to + + align:start position:0% +milliseconds followed by a mask in to + + + align:start position:0% +milliseconds followed by a mask in to +recognize correctly at the human level + + align:start position:0% +recognize correctly at the human level + + + align:start position:0% +recognize correctly at the human level +to get to the human level that we get + + align:start position:0% +to get to the human level that we get + + + align:start position:0% +to get to the human level that we get +with minimal images you have to give + + align:start position:0% +with minimal images you have to give + + + align:start position:0% +with minimal images you have to give +enough time which we suspect that enough + + align:start position:0% +enough time which we suspect that enough + + + align:start position:0% +enough time which we suspect that enough +time is to allow the application of the + + align:start position:0% +time is to allow the application of the + + + align:start position:0% +time is to allow the application of the +top-down interpretation routine and it's + + align:start position:0% +top-down interpretation routine and it's + + + align:start position:0% +top-down interpretation routine and it's +even if you don't give enough time then + + align:start position:0% +even if you don't give enough time then + + + align:start position:0% +even if you don't give enough time then +people that generate and become deep + + align:start position:0% +people that generate and become deep + + + align:start position:0% +people that generate and become deep +networks and you get this the same kind + + align:start position:0% +networks and you get this the same kind + + + align:start position:0% +networks and you get this the same kind +of performance roughly but this is all + + align:start position:0% +of performance roughly but this is all + + + align:start position:0% +of performance roughly but this is all +still unpublished and + + align:start position:0% +still unpublished and + + + align:start position:0% +still unpublished and +still running and we need more subjects + + align:start position:0% +still running and we need more subjects + + + align:start position:0% +still running and we need more subjects +and all of this is looking in the right + + align:start position:0% +and all of this is looking in the right + + + align:start position:0% +and all of this is looking in the right +direction and looking in providing + + align:start position:0% +direction and looking in providing + + + align:start position:0% +direction and looking in providing +support for top-down processing for this + + align:start position:0% +support for top-down processing for this + + + align:start position:0% +support for top-down processing for this +and this by the way for it's interesting + + align:start position:0% +and this by the way for it's interesting + + + align:start position:0% +and this by the way for it's interesting +methodologically because it's very + + align:start position:0% +methodologically because it's very + + + align:start position:0% +methodologically because it's very +difficult with real images it's so rich + + align:start position:0% +difficult with real images it's so rich + + + align:start position:0% +difficult with real images it's so rich +and you get so much information already + + align:start position:0% +and you get so much information already + + + align:start position:0% +and you get so much information already +in the way of going up and because of + + align:start position:0% +in the way of going up and because of + + + align:start position:0% +in the way of going up and because of +this redundancy that even if you make + + align:start position:0% +this redundancy that even if you make + + + align:start position:0% +this redundancy that even if you make +20% arrow it doesn't really matter + + align:start position:0% +20% arrow it doesn't really matter + + + align:start position:0% +20% arrow it doesn't really matter +because you have redundancy many + + align:start position:0% +because you have redundancy many + + + align:start position:0% +because you have redundancy many +multiple sufficient minimal images + + align:start position:0% +multiple sufficient minimal images + + + align:start position:0% +multiple sufficient minimal images +within any object and so on so it's very + + align:start position:0% +within any object and so on so it's very + + + align:start position:0% +within any object and so on so it's very +difficult to tease out the effect of + + align:start position:0% +difficult to tease out the effect of + + + align:start position:0% +difficult to tease out the effect of +where exactly the top-down information + + align:start position:0% +where exactly the top-down information + + + align:start position:0% +where exactly the top-down information +starts what you need it where you where + + align:start position:0% +starts what you need it where you where + + + align:start position:0% +starts what you need it where you where +exactly you fail if you do if you don't + + align:start position:0% +exactly you fail if you do if you don't + + + align:start position:0% +exactly you fail if you do if you don't +have it so we think we you need it for + + align:start position:0% +have it so we think we you need it for + + + align:start position:0% +have it so we think we you need it for +this internal interpretation and for the + + align:start position:0% +this internal interpretation and for the + + + align:start position:0% +this internal interpretation and for the +correct recognition of minimum images + + align:start position:0% +correct recognition of minimum images + + + align:start position:0% +correct recognition of minimum images +and here you can start seeing good + + align:start position:0% +and here you can start seeing good + + + align:start position:0% +and here you can start seeing good +signals in the in the mag it provides + + align:start position:0% +signals in the in the mag it provides + + + align:start position:0% +signals in the in the mag it provides +you sort of a tool that is pretty unique + + align:start position:0% +you sort of a tool that is pretty unique + + + align:start position:0% +you sort of a tool that is pretty unique +and allows you to do to do these things + + align:start position:0% +and allows you to do to do these things + + + align:start position:0% +and allows you to do to do these things +so let me add with very informal thing + + align:start position:0% +so let me add with very informal thing + + + align:start position:0% +so let me add with very informal thing +but where I think this is going I think + + align:start position:0% +but where I think this is going I think + + + align:start position:0% +but where I think this is going I think +that when you look at difficult images + + align:start position:0% +that when you look at difficult images + + + align:start position:0% +that when you look at difficult images +like action recognition which we + + align:start position:0% +like action recognition which we + + + align:start position:0% +like action recognition which we +discussed below many things that we do + + align:start position:0% +discussed below many things that we do + + + align:start position:0% +discussed below many things that we do +depend not on sort of course level label + + align:start position:0% +depend not on sort of course level label + + + align:start position:0% +depend not on sort of course level label +of there is a person there is airplane + + align:start position:0% +of there is a person there is airplane + + + align:start position:0% +of there is a person there is airplane +or is a dog but really things depend on + + align:start position:0% +or is a dog but really things depend on + + + align:start position:0% +or is a dog but really things depend on +they flying details of the internal + + align:start position:0% +they flying details of the internal + + + align:start position:0% +they flying details of the internal +interpretation and so if you can turn + + align:start position:0% +interpretation and so if you can turn + + + align:start position:0% +interpretation and so if you can turn +off the what I think is the top-down + + align:start position:0% +off the what I think is the top-down + + + align:start position:0% +off the what I think is the top-down +part of class specific top-down + + align:start position:0% +part of class specific top-down + + + align:start position:0% +part of class specific top-down +processes I think that many of this fine + + align:start position:0% +processes I think that many of this fine + + + align:start position:0% +processes I think that many of this fine +distinction that we make all the time + + align:start position:0% +distinction that we make all the time + + + align:start position:0% +distinction that we make all the time +and it's what vision is all about vision + + align:start position:0% +and it's what vision is all about vision + + + align:start position:0% +and it's what vision is all about vision +is not about giving course categories + + align:start position:0% +is not about giving course categories + + + align:start position:0% +is not about giving course categories +will go away and so these things will + + align:start position:0% +will go away and so these things will + + + align:start position:0% +will go away and so these things will +become more and more an important part + + align:start position:0% +become more and more an important part + + + align:start position:0% +become more and more an important part +of vision let me look at this + + align:start position:0% +of vision let me look at this + + + align:start position:0% +of vision let me look at this +variability in action recognition but + + align:start position:0% +variability in action recognition but + + + align:start position:0% +variability in action recognition but +let me show you some specific examples + + align:start position:0% + + + + align:start position:0% + +this is something that confuses current + + align:start position:0% +this is something that confuses current + + + align:start position:0% +this is something that confuses current +classifiers that in both of them it + + align:start position:0% +classifiers that in both of them it + + + align:start position:0% +classifiers that in both of them it +seemed that the person is drinking this + + align:start position:0% +seemed that the person is drinking this + + + align:start position:0% +seemed that the person is drinking this +was + + align:start position:0% +was + + + align:start position:0% +was +because there is you know person there + + align:start position:0% +because there is you know person there + + + align:start position:0% +because there is you know person there +is a bottle and the bottle is close to + + align:start position:0% +is a bottle and the bottle is close to + + + align:start position:0% +is a bottle and the bottle is close to +the to the mouse or the person is + + align:start position:0% +the to the mouse or the person is + + + align:start position:0% +the to the mouse or the person is +drinking at this rough level of + + align:start position:0% +drinking at this rough level of + + + align:start position:0% +drinking at this rough level of +description but obviously you know this + + align:start position:0% +description but obviously you know this + + + align:start position:0% +description but obviously you know this +person is drinking this person is + + align:start position:0% +person is drinking this person is + + + align:start position:0% +person is drinking this person is +pouring right something very is this + + align:start position:0% +pouring right something very is this + + + align:start position:0% +pouring right something very is this +person drinking at the moment yes or no + + align:start position:0% +person drinking at the moment yes or no + + + align:start position:0% +person drinking at the moment yes or no +no why not she is holding a cup and it's + + align:start position:0% +no why not she is holding a cup and it's + + + align:start position:0% +no why not she is holding a cup and it's +not you know maybe on the way to them we + + align:start position:0% +not you know maybe on the way to them we + + + align:start position:0% +not you know maybe on the way to them we +know that she's not drinking right but + + align:start position:0% +know that she's not drinking right but + + + align:start position:0% +know that she's not drinking right but +why exactly not and again this is + + align:start position:0% +why exactly not and again this is + + + align:start position:0% +why exactly not and again this is +something that is picked up with + + align:start position:0% +something that is picked up with + + + align:start position:0% +something that is picked up with +drinking by many recognition system but + + align:start position:0% +drinking by many recognition system but + + + align:start position:0% +drinking by many recognition system but +it's something is wrong here + + align:start position:0% +it's something is wrong here + + + align:start position:0% +it's something is wrong here +all of these things these are different + + align:start position:0% +all of these things these are different + + + align:start position:0% +all of these things these are different +objects and different actions that the + + align:start position:0% +objects and different actions that the + + + align:start position:0% +objects and different actions that the +people are performing this is drinking + + align:start position:0% +people are performing this is drinking + + + align:start position:0% +people are performing this is drinking +from a straw this is smoking and this is + + align:start position:0% +from a straw this is smoking and this is + + + align:start position:0% +from a straw this is smoking and this is +brushing their teeth but this depends on + + align:start position:0% +brushing their teeth but this depends on + + + align:start position:0% +brushing their teeth but this depends on +you know you have to go to the right + + align:start position:0% +you know you have to go to the right + + + align:start position:0% +you know you have to go to the right +location and decide exactly what's + + align:start position:0% +location and decide exactly what's + + + align:start position:0% +location and decide exactly what's +happening there it's the kind of thing + + align:start position:0% +happening there it's the kind of thing + + + align:start position:0% +happening there it's the kind of thing +that we do all the time some more + + align:start position:0% +that we do all the time some more + + + align:start position:0% +that we do all the time some more +challenges this is just sort of informal + + align:start position:0% +challenges this is just sort of informal + + + align:start position:0% +challenges this is just sort of informal +challenges to show you how we can deal + + align:start position:0% +challenges to show you how we can deal + + + align:start position:0% +challenges to show you how we can deal +with fine interpretation of details of + + align:start position:0% +with fine interpretation of details of + + + align:start position:0% +with fine interpretation of details of +interest in the image what is this arrow + + align:start position:0% +interest in the image what is this arrow + + + align:start position:0% +interest in the image what is this arrow +point pointing at sorry yeah but above + + align:start position:0% +point pointing at sorry yeah but above + + + align:start position:0% +point pointing at sorry yeah but above +the bottle there is something else there + + align:start position:0% +the bottle there is something else there + + + align:start position:0% +the bottle there is something else there +sorry fingers right let's see just what + + align:start position:0% +sorry fingers right let's see just what + + + align:start position:0% +sorry fingers right let's see just what +is this arrow pointing it zipper let's + + align:start position:0% +is this arrow pointing it zipper let's + + + align:start position:0% +is this arrow pointing it zipper let's +see this is your two challenging things + + align:start position:0% +see this is your two challenging things + + + align:start position:0% +see this is your two challenging things +you are - what what is this one pointing + + align:start position:0% +you are - what what is this one pointing + + + align:start position:0% +you are - what what is this one pointing +it alright not next to the cup right + + align:start position:0% +it alright not next to the cup right + + + align:start position:0% +it alright not next to the cup right +it's also this is really challenging + + align:start position:0% +it's also this is really challenging + + + align:start position:0% +it's also this is really challenging +let's see what is this one pointing at + + align:start position:0% +let's see what is this one pointing at + + + align:start position:0% +let's see what is this one pointing at +tray not really so the trace think about + + align:start position:0% +tray not really so the trace think about + + + align:start position:0% +tray not really so the trace think about +it this but you match it with this thing + + align:start position:0% +it this but you match it with this thing + + + align:start position:0% +it this but you match it with this thing +here in order to make sure to know that + + align:start position:0% +here in order to make sure to know that + + + align:start position:0% +here in order to make sure to know that +it's it's a tray it's not something that + + align:start position:0% +it's it's a tray it's not something that + + + align:start position:0% +it's it's a tray it's not something that +will be easily picked up but I mean I'm + + align:start position:0% +will be easily picked up but I mean I'm + + + align:start position:0% +will be easily picked up but I mean I'm +looking for difficult things which are a + + align:start position:0% +looking for difficult things which are a + + + align:start position:0% +looking for difficult things which are a +little bit challenging and you say oh I + + align:start position:0% +little bit challenging and you say oh I + + + align:start position:0% +little bit challenging and you say oh I +can get it but it's in this level of + + align:start position:0% +can get it but it's in this level of + + + align:start position:0% +can get it but it's in this level of +detail interpreting the fine details in + + align:start position:0% +detail interpreting the fine details in + + + align:start position:0% +detail interpreting the fine details in +images in a top-down fashion happens all + + align:start position:0% +images in a top-down fashion happens all + + + align:start position:0% +images in a top-down fashion happens all +the time + + align:start position:0% +the time + + + align:start position:0% +the time +this person smoking of course not and we + + align:start position:0% +this person smoking of course not and we + + + align:start position:0% +this person smoking of course not and we +are not fooled by it and we immediately + + align:start position:0% +are not fooled by it and we immediately + + + align:start position:0% +are not fooled by it and we immediately +zoom on the right things and it's really + + align:start position:0% +zoom on the right things and it's really + + + align:start position:0% +zoom on the right things and it's really +all the information is here at the end + + align:start position:0% +all the information is here at the end + + + align:start position:0% +all the information is here at the end +so in so on zone and so forth I mean we + + align:start position:0% +so in so on zone and so forth I mean we + + + align:start position:0% +so in so on zone and so forth I mean we +were looking at dealing visually with + + align:start position:0% +were looking at dealing visually with + + + align:start position:0% +were looking at dealing visually with +social interactions understanding the + + align:start position:0% +social interactions understanding the + + + align:start position:0% +social interactions understanding the +social interactions between agents in + + align:start position:0% +social interactions between agents in + + + align:start position:0% +social interactions between agents in +there and again it's very difficult to + + align:start position:0% +there and again it's very difficult to + + + align:start position:0% +there and again it's very difficult to +do correctly and it depends on subtle + + align:start position:0% +do correctly and it depends on subtle + + + align:start position:0% +do correctly and it depends on subtle +subtle things I mean you can get + + align:start position:0% +subtle things I mean you can get + + + align:start position:0% +subtle things I mean you can get +something rough okay but for example is + + align:start position:0% +something rough okay but for example is + + + align:start position:0% +something rough okay but for example is +this sort of an intimate hug or is this + + align:start position:0% +this sort of an intimate hug or is this + + + align:start position:0% +this sort of an intimate hug or is this +just cordial hug of people who are not + + align:start position:0% +just cordial hug of people who are not + + + align:start position:0% +just cordial hug of people who are not +we know exactly what's going on right + + align:start position:0% +we know exactly what's going on right + + + align:start position:0% +we know exactly what's going on right +and it turns out that the features are + + align:start position:0% +and it turns out that the features are + + + align:start position:0% +and it turns out that the features are +not that easy to get this was picked up + + align:start position:0% +not that easy to get this was picked up + + + align:start position:0% +not that easy to get this was picked up +incorrectly by something that we + + align:start position:0% +incorrectly by something that we + + + align:start position:0% +incorrectly by something that we +designed for people hugging and it's not + + align:start position:0% +designed for people hugging and it's not + + + align:start position:0% +designed for people hugging and it's not +very far from people hugging but it + + align:start position:0% +very far from people hugging but it + + + align:start position:0% +very far from people hugging but it +doesn't fool doesn't fool us right I'm + + align:start position:0% +doesn't fool doesn't fool us right I'm + + + align:start position:0% +doesn't fool doesn't fool us right I'm +not not really hugging on social + + align:start position:0% +not not really hugging on social + + + align:start position:0% +not not really hugging on social +interaction we know interactions even + + align:start position:0% +interaction we know interactions even + + + align:start position:0% +interaction we know interactions even +between non-human agents I mean this + + align:start position:0% +between non-human agents I mean this + + + align:start position:0% +between non-human agents I mean this +interaction is this is threatening + + align:start position:0% +interaction is this is threatening + + + align:start position:0% +interaction is this is threatening +interaction or friendly interaction what + + align:start position:0% +interaction or friendly interaction what + + + align:start position:0% +interaction or friendly interaction what +do you think right I think anyway I + + align:start position:0% +do you think right I think anyway I + + + align:start position:0% +do you think right I think anyway I +think that all of this thing that we can + + align:start position:0% +think that all of this thing that we can + + + align:start position:0% +think that all of this thing that we can +do and I think that vision is about this + + align:start position:0% +do and I think that vision is about this + + + align:start position:0% +do and I think that vision is about this +it's not about looking at this room and + + align:start position:0% +it's not about looking at this room and + + + align:start position:0% +it's not about looking at this room and +saying that this is a computer and this + + align:start position:0% +saying that this is a computer and this + + + align:start position:0% +saying that this is a computer and this +is a chair it's about understanding the + + align:start position:0% +is a chair it's about understanding the + + + align:start position:0% +is a chair it's about understanding the +situation and making fine judgments and + + align:start position:0% +situation and making fine judgments and + + + align:start position:0% +situation and making fine judgments and +interacting with objects and in fact we + + align:start position:0% +interacting with objects and in fact we + + + align:start position:0% +interacting with objects and in fact we +are looking at the past part of doing + + align:start position:0% +are looking at the past part of doing + + + align:start position:0% +are looking at the past part of doing +CBMM we are looking at the problem of + + align:start position:0% +CBMM we are looking at the problem of + + + align:start position:0% +CBMM we are looking at the problem of +asking questions about images so we want + + align:start position:0% +asking questions about images so we want + + + align:start position:0% +asking questions about images so we want +a system that you can give it an image + + align:start position:0% +a system that you can give it an image + + + align:start position:0% +a system that you can give it an image +in a question and then we want the + + align:start position:0% +in a question and then we want the + + + align:start position:0% +in a question and then we want the +system to be able to process the image + + align:start position:0% +system to be able to process the image + + + align:start position:0% +system to be able to process the image +in such a way that will give you a good + + align:start position:0% +in such a way that will give you a good + + + align:start position:0% +in such a way that will give you a good +answer to the question and this is + + align:start position:0% +answer to the question and this is + + + align:start position:0% +answer to the question and this is +interesting because it means that it's + + align:start position:0% +interesting because it means that it's + + + align:start position:0% +interesting because it means that it's +not just a generic pipeline of running + + align:start position:0% +not just a generic pipeline of running + + + align:start position:0% +not just a generic pipeline of running +the imagery pipeline sort of fixed + + align:start position:0% +the imagery pipeline sort of fixed + + + align:start position:0% +the imagery pipeline sort of fixed +sequence of operations but depending on + + align:start position:0% +sequence of operations but depending on + + + align:start position:0% +sequence of operations but depending on +what you're interested in the whole + + align:start position:0% +what you're interested in the whole + + + align:start position:0% +what you're interested in the whole +visual process should be directed in a + + align:start position:0% +visual process should be directed in a + + + align:start position:0% +visual process should be directed in a +particular way to produce just the + + align:start position:0% +particular way to produce just the + + + align:start position:0% +particular way to produce just the +relevant answer and we looked at it set + + align:start position:0% +relevant answer and we looked at it set + + + align:start position:0% +relevant answer and we looked at it set +of with the student we looked at a set + + align:start position:0% +of with the student we looked at a set + + + align:start position:0% +of with the student we looked at a set +of some 600 question that we gave people + + align:start position:0% +of some 600 question that we gave people + + + align:start position:0% +of some 600 question that we gave people +on the mechanical torque images and they + + align:start position:0% +on the mechanical torque images and they + + + align:start position:0% +on the mechanical torque images and they +say imagine some questions about the + + align:start position:0% +say imagine some questions about the + + + align:start position:0% +say imagine some questions about the +images asked some question about these + + align:start position:0% +images asked some question about these + + + align:start position:0% +images asked some question about these +images and they came up with some images + + align:start position:0% +images and they came up with some images + + + align:start position:0% +images and they came up with some images +we looked at them in an informal + + align:start position:0% +we looked at them in an informal + + + align:start position:0% +we looked at them in an informal +observation initial observation is that + + align:start position:0% +observation initial observation is that + + + align:start position:0% +observation initial observation is that +most of this question that people + + align:start position:0% +most of this question that people + + + align:start position:0% +most of this question that people +invented to ask about images you needed + + align:start position:0% +invented to ask about images you needed + + + align:start position:0% +invented to ask about images you needed +some things which depended on precise + + align:start position:0% +some things which depended on precise + + + align:start position:0% +some things which depended on precise +internal interpretation of the details + + align:start position:0% +internal interpretation of the details + + + align:start position:0% +internal interpretation of the details +so it's saying it's things that come up + + align:start position:0% +so it's saying it's things that come up + + + align:start position:0% +so it's saying it's things that come up +all the time you have to dive into the + + align:start position:0% +all the time you have to dive into the + + + align:start position:0% +all the time you have to dive into the +image and analyze the subtle cues that + + align:start position:0% +image and analyze the subtle cues that + + + align:start position:0% +image and analyze the subtle cues that +will tell you that these are not hugging + + align:start position:0% +will tell you that these are not hugging + + + align:start position:0% +will tell you that these are not hugging +and this is not threatening and this is + + align:start position:0% +and this is not threatening and this is + + + align:start position:0% +and this is not threatening and this is +not an intimate hug and so on and so + + align:start position:0% +not an intimate hug and so on and so + + + align:start position:0% +not an intimate hug and so on and so +forth and this is what we are the whole + + align:start position:0% +forth and this is what we are the whole + + + align:start position:0% +forth and this is what we are the whole +story of the minimal images and internal + + align:start position:0% +story of the minimal images and internal + + + align:start position:0% +story of the minimal images and internal +interpretation is the the real goal + + align:start position:0% +interpretation is the the real goal + + + align:start position:0% +interpretation is the the real goal +eventually is to be able to identify the + + align:start position:0% +eventually is to be able to identify the + + + align:start position:0% +eventually is to be able to identify the +important visual features and structures + + align:start position:0% +important visual features and structures + + + align:start position:0% +important visual features and structures +which are important for this and + + align:start position:0% +which are important for this and + + + align:start position:0% +which are important for this and +thinking about the automatic learning of + + align:start position:0% +thinking about the automatic learning of + + + align:start position:0% +thinking about the automatic learning of +the how to extract the internal + + align:start position:0% +the how to extract the internal + + + align:start position:0% +the how to extract the internal +structure that will be support the + + align:start position:0% +structure that will be support the + + + align:start position:0% +structure that will be support the +interpretation of all these interesting + + align:start position:0% +interpretation of all these interesting + + + align:start position:0% +interpretation of all these interesting +and meaningful aspects of images that at + + align:start position:0% +and meaningful aspects of images that at + + + align:start position:0% +and meaningful aspects of images that at +the moment we do not have okay I think + + align:start position:0% +the moment we do not have okay I think + + + align:start position:0% +the moment we do not have okay I think +I've said I've said all of all of these + + align:start position:0% +I've said I've said all of all of these + + + align:start position:0% +I've said I've said all of all of these +conclusions already in the final comment + + align:start position:0% +conclusions already in the final comment + + + align:start position:0% +conclusions already in the final comment +so let me stop here + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/Y9Awwqqc288.txt b/Y9Awwqqc288.txt new file mode 100644 index 0000000000000000000000000000000000000000..bee04f940323ee2d1f8b376eed2bbf0fe8b4c064 --- /dev/null +++ b/Y9Awwqqc288.txt @@ -0,0 +1,7008 @@ +align:start position:0% + +good okay so last time right at the end + + align:start position:0% +good okay so last time right at the end + + + align:start position:0% +good okay so last time right at the end +of the lecture I had um introduced a + + align:start position:0% +of the lecture I had um introduced a + + + align:start position:0% +of the lecture I had um introduced a +more General linear model the + + align:start position:0% +more General linear model the + + + align:start position:0% +more General linear model the +multivariant um linear model okay and I + + align:start position:0% +multivariant um linear model okay and I + + + align:start position:0% +multivariant um linear model okay and I +had just um gone through the first + + align:start position:0% +had just um gone through the first + + + align:start position:0% +had just um gone through the first +couple of these slides SL saying let's + + align:start position:0% +couple of these slides SL saying let's + + + align:start position:0% +couple of these slides SL saying let's +uh let's sort of analyze this model + + align:start position:0% +uh let's sort of analyze this model + + + align:start position:0% +uh let's sort of analyze this model +using a different notation in particular + + align:start position:0% +using a different notation in particular + + + align:start position:0% +using a different notation in particular +Matrix notation uh because the sort of + + align:start position:0% +Matrix notation uh because the sort of + + + align:start position:0% +Matrix notation uh because the sort of +summation notation was just too clunky + + align:start position:0% +summation notation was just too clunky + + + align:start position:0% +summation notation was just too clunky +it wasn't up for the job um and so let + + align:start position:0% +it wasn't up for the job um and so let + + + align:start position:0% +it wasn't up for the job um and so let +me just go through + + align:start position:0% +me just go through + + + align:start position:0% +me just go through +quickly let's see this was I think the + + align:start position:0% +quickly let's see this was I think the + + + align:start position:0% +quickly let's see this was I think the +next to last slide I had up um so if we + + align:start position:0% +next to last slide I had up um so if we + + + align:start position:0% +next to last slide I had up um so if we +let uh y be the column Vector of all of + + align:start position:0% +let uh y be the column Vector of all of + + + align:start position:0% +let uh y be the column Vector of all of +the object observations on the dependent + + align:start position:0% +the object observations on the dependent + + + align:start position:0% +the object observations on the dependent +variable then let uh Epsilon be the + + align:start position:0% +variable then let uh Epsilon be the + + + align:start position:0% +variable then let uh Epsilon be the +column Vector of all of the errors and + + align:start position:0% +column Vector of all of the errors and + + + align:start position:0% +column Vector of all of the errors and +then let X be the Matrix where across + + align:start position:0% +then let X be the Matrix where across + + + align:start position:0% +then let X be the Matrix where across +the rows of the Matrix we have uh all of + + align:start position:0% +the rows of the Matrix we have uh all of + + + align:start position:0% +the rows of the Matrix we have uh all of +the the uh first a column of ones and + + align:start position:0% +the the uh first a column of ones and + + + align:start position:0% +the the uh first a column of ones and +then a column of each of the um the + + align:start position:0% +then a column of each of the um the + + + align:start position:0% +then a column of each of the um the +explanatory variables and then sort of + + align:start position:0% +explanatory variables and then sort of + + + align:start position:0% +explanatory variables and then sort of +down uh you know sort of uh Down The + + align:start position:0% +down uh you know sort of uh Down The + + + align:start position:0% +down uh you know sort of uh Down The +Matrix we have uh observations on each + + align:start position:0% +Matrix we have uh observations on each + + + align:start position:0% +Matrix we have uh observations on each +of the well we have each of the + + align:start position:0% +of the well we have each of the + + + align:start position:0% +of the well we have each of the +observations each observation + + align:start position:0% +observations each observation + + + align:start position:0% +observations each observation +corresponds to a row so if we Define uh + + align:start position:0% +corresponds to a row so if we Define uh + + + align:start position:0% +corresponds to a row so if we Define uh +these this Matrix and vectors this way + + align:start position:0% +these this Matrix and vectors this way + + + align:start position:0% +these this Matrix and vectors this way +uh then we can write our + + align:start position:0% +uh then we can write our + + + align:start position:0% +uh then we can write our +multivariate linear model in the + + align:start position:0% +multivariate linear model in the + + + align:start position:0% +multivariate linear model in the +following very parsimonious fashion y + + align:start position:0% +following very parsimonious fashion y + + + align:start position:0% +following very parsimonious fashion y +equal x beta plus Epsilon + + align:start position:0% +equal x beta plus Epsilon + + + align:start position:0% +equal x beta plus Epsilon +okay okay so now um we have + + align:start position:0% +okay okay so now um we have + + + align:start position:0% +okay okay so now um we have +uh the we're we're B I'm basically going + + align:start position:0% +uh the we're we're B I'm basically going + + + align:start position:0% +uh the we're we're B I'm basically going +to go through the same assumptions but + + align:start position:0% +to go through the same assumptions but + + + align:start position:0% +to go through the same assumptions but +in a slightly more General way from uh + + align:start position:0% +in a slightly more General way from uh + + + align:start position:0% +in a slightly more General way from uh +when I discussed assumptions in the B + + align:start position:0% +when I discussed assumptions in the B + + + align:start position:0% +when I discussed assumptions in the B +variant model the assumptions have to be + + align:start position:0% +variant model the assumptions have to be + + + align:start position:0% +variant model the assumptions have to be +discussed in a more General way now + + align:start position:0% +discussed in a more General way now + + + align:start position:0% +discussed in a more General way now +because actually they're a little bit + + align:start position:0% +because actually they're a little bit + + + align:start position:0% +because actually they're a little bit +more complicated with the + + align:start position:0% +more complicated with the + + + align:start position:0% +more complicated with the +multivariate um the multivariate model + + align:start position:0% +multivariate um the multivariate model + + + align:start position:0% +multivariate um the multivariate model +okay so uh I'm going to condense all of + + align:start position:0% +okay so uh I'm going to condense all of + + + align:start position:0% +okay so uh I'm going to condense all of +the assumptions into two basic + + align:start position:0% +the assumptions into two basic + + + align:start position:0% +the assumptions into two basic +categories one is the identification + + align:start position:0% +categories one is the identification + + + align:start position:0% +categories one is the identification +assumptions and two is the assumptions + + align:start position:0% +assumptions and two is the assumptions + + + align:start position:0% +assumptions and two is the assumptions +in the error Behavior okay so in the + + align:start position:0% +in the error Behavior okay so in the + + + align:start position:0% +in the error Behavior okay so in the +multivariate linear model in order to + + align:start position:0% +multivariate linear model in order to + + + align:start position:0% +multivariate linear model in order to +have identification in order to be able + + align:start position:0% +have identification in order to be able + + + align:start position:0% +have identification in order to be able +to estimate our model we have to have n + + align:start position:0% +to estimate our model we have to have n + + + align:start position:0% +to estimate our model we have to have n +greater than k+ one that just means we + + align:start position:0% +greater than k+ one that just means we + + + align:start position:0% +greater than k+ one that just means we +have to have more observations than we + + align:start position:0% +have to have more observations than we + + + align:start position:0% +have to have more observations than we +have uh explanatory + + align:start position:0% +have uh explanatory + + + align:start position:0% +have uh explanatory +variables plus one + + align:start position:0% +variables plus one + + + align:start position:0% +variables plus one +okay and uh X has to have full column + + align:start position:0% +okay and uh X has to have full column + + + align:start position:0% +okay and uh X has to have full column +rank + + align:start position:0% +rank + + + align:start position:0% +rank +of k + + + align:start position:0% +of k + + + + align:start position:0% +of k + +1 and what does that mean in other words + + align:start position:0% +1 and what does that mean in other words + + + align:start position:0% +1 and what does that mean in other words +means that the regressors have to be + + align:start position:0% +means that the regressors have to be + + + align:start position:0% +means that the regressors have to be +linearly independent or another way of + + align:start position:0% +linearly independent or another way of + + + align:start position:0% +linearly independent or another way of +saying this is that the Matrix X prime + + align:start position:0% +saying this is that the Matrix X prime + + + align:start position:0% +saying this is that the Matrix X prime +or X transpose X is invertible okay I'm + + align:start position:0% +or X transpose X is invertible okay I'm + + + align:start position:0% +or X transpose X is invertible okay I'm +going to go through this in some more + + align:start position:0% +going to go through this in some more + + + align:start position:0% +going to go through this in some more +detail in just a + + align:start position:0% +detail in just a + + + align:start position:0% +detail in just a +second and then the second main + + align:start position:0% +second and then the second main + + + align:start position:0% +second and then the second main +assumption or main category of + + align:start position:0% +assumption or main category of + + + align:start position:0% +assumption or main category of +assumptions on the error behavior and + + align:start position:0% +assumptions on the error behavior and + + + align:start position:0% +assumptions on the error behavior and +these actually are exactly like the + + align:start position:0% +these actually are exactly like the + + + align:start position:0% +these actually are exactly like the +assumptions we saw before just using + + align:start position:0% +assumptions we saw before just using + + + align:start position:0% +assumptions we saw before just using +Matrix notation to to express them so + + align:start position:0% +Matrix notation to to express them so + + + align:start position:0% +Matrix notation to to express them so +here we have the expectation of Epsilon + + align:start position:0% +here we have the expectation of Epsilon + + + align:start position:0% +here we have the expectation of Epsilon +here Epsilon is a vector and that's the + + align:start position:0% +here Epsilon is a vector and that's the + + + align:start position:0% +here Epsilon is a vector and that's the +vector of zeros okay the expectation of + + align:start position:0% +vector of zeros okay the expectation of + + + align:start position:0% +vector of zeros okay the expectation of +Epsilon Epsilon transpose is equal to + + align:start position:0% +Epsilon Epsilon transpose is equal to + + + align:start position:0% +Epsilon Epsilon transpose is equal to +Sigma squar times the N byn identity + + align:start position:0% +Sigma squar times the N byn identity + + + align:start position:0% +Sigma squar times the N byn identity +Matrix okay and this is in fact this + + align:start position:0% +Matrix okay and this is in fact this + + + align:start position:0% +Matrix okay and this is in fact this +Matrix here is in fact just the Matrix + + align:start position:0% +Matrix here is in fact just the Matrix + + + align:start position:0% +Matrix here is in fact just the Matrix +uh that we denote co uh Co covariance of + + align:start position:0% +uh that we denote co uh Co covariance of + + + align:start position:0% +uh that we denote co uh Co covariance of +Epsilon which is I'll show you a picture + + align:start position:0% +Epsilon which is I'll show you a picture + + + align:start position:0% +Epsilon which is I'll show you a picture +of it in a second it's just a matrix + + align:start position:0% +of it in a second it's just a matrix + + + align:start position:0% +of it in a second it's just a matrix +that has the variances of Epsilon along + + align:start position:0% +that has the variances of Epsilon along + + + align:start position:0% +that has the variances of Epsilon along +the diagonal and the co-variances on the + + align:start position:0% +the diagonal and the co-variances on the + + + align:start position:0% +the diagonal and the co-variances on the +off diagonal okay and so what we're + + align:start position:0% +off diagonal okay and so what we're + + + align:start position:0% +off diagonal okay and so what we're +saying here is that the the diagonal is + + align:start position:0% +saying here is that the the diagonal is + + + align:start position:0% +saying here is that the the diagonal is +equal to Sigma + + align:start position:0% +equal to Sigma + + + align:start position:0% +equal to Sigma +squar okay and the off diagonals are + + align:start position:0% +squar okay and the off diagonals are + + + align:start position:0% +squar okay and the off diagonals are +zeros + + align:start position:0% + + + + align:start position:0% + +and a stronger version of this is that + + align:start position:0% +and a stronger version of this is that + + + align:start position:0% +and a stronger version of this is that +Epsilon uh the Epsilon Vector has this + + align:start position:0% +Epsilon uh the Epsilon Vector has this + + + align:start position:0% +Epsilon uh the Epsilon Vector has this +normal this multivariant normal + + align:start position:0% +normal this multivariant normal + + + align:start position:0% +normal this multivariant normal +distribution with this variance + + align:start position:0% +distribution with this variance + + + align:start position:0% +distribution with this variance +covariance + + align:start position:0% +covariance + + + align:start position:0% +covariance +Matrix okay I I'll go into more detail + + align:start position:0% +Matrix okay I I'll go into more detail + + + align:start position:0% +Matrix okay I I'll go into more detail +of in both of these in just a second + + align:start position:0% +of in both of these in just a second + + + align:start position:0% +of in both of these in just a second +okay so let's do the oh n by n identity + + align:start position:0% +okay so let's do the oh n by n identity + + + align:start position:0% +okay so let's do the oh n by n identity +Matrix okay so let's take a closer look + + align:start position:0% +Matrix okay so let's take a closer look + + + align:start position:0% +Matrix okay so let's take a closer look +at these assumptions so assumption one + + align:start position:0% +at these assumptions so assumption one + + + align:start position:0% +at these assumptions so assumption one +the identification assumption um what + + align:start position:0% +the identification assumption um what + + + align:start position:0% +the identification assumption um what +exactly does this mean well we need to + + align:start position:0% +exactly does this mean well we need to + + + align:start position:0% +exactly does this mean well we need to +have more observations than regressors + + align:start position:0% +have more observations than regressors + + + align:start position:0% +have more observations than regressors +that shouldn't come as a surprise + + align:start position:0% +that shouldn't come as a surprise + + + align:start position:0% +that shouldn't come as a surprise +especially if we think about the B + + align:start position:0% +especially if we think about the B + + + align:start position:0% +especially if we think about the B +variant model um you know we have one + + align:start position:0% +variant model um you know we have one + + + align:start position:0% +variant model um you know we have one +regressor you have to have at least two + + align:start position:0% +regressor you have to have at least two + + + align:start position:0% +regressor you have to have at least two +observations or else you can't draw a + + align:start position:0% +observations or else you can't draw a + + + align:start position:0% +observations or else you can't draw a +line okay so this just sort of + + align:start position:0% +line okay so this just sort of + + + align:start position:0% +line okay so this just sort of +generalizes that to to higher Dimensions + + align:start position:0% +generalizes that to to higher Dimensions + + + align:start position:0% +generalizes that to to higher Dimensions +uh we can't have any regressors that do + + align:start position:0% +uh we can't have any regressors that do + + + align:start position:0% +uh we can't have any regressors that do +not have positive sample variation so we + + align:start position:0% +not have positive sample variation so we + + + align:start position:0% +not have positive sample variation so we +saw this assumption in the B variant + + align:start position:0% +saw this assumption in the B variant + + + align:start position:0% +saw this assumption in the B variant +case remember I had a picture that + + align:start position:0% +case remember I had a picture that + + + align:start position:0% +case remember I had a picture that +looked + + align:start position:0% + + + + align:start position:0% + +like I had a picture that looked like + + align:start position:0% +like I had a picture that looked like + + + align:start position:0% +like I had a picture that looked like +this and I said if all of our + + align:start position:0% +this and I said if all of our + + + align:start position:0% +this and I said if all of our +observations are on the same value of x + + align:start position:0% +observations are on the same value of x + + + align:start position:0% +observations are on the same value of x +we can't uh we can't + + align:start position:0% +we can't uh we can't + + + align:start position:0% +we can't uh we can't +identify um + + align:start position:0% +identify um + + + align:start position:0% +identify um +the how the conditional mean of Y + + align:start position:0% +the how the conditional mean of Y + + + align:start position:0% +the how the conditional mean of Y +changes with X okay well again in the + + align:start position:0% +changes with X okay well again in the + + + align:start position:0% +changes with X okay well again in the +multivariant regression uh or the + + align:start position:0% +multivariant regression uh or the + + + align:start position:0% +multivariant regression uh or the +multivariant case we can't identify uh + + align:start position:0% +multivariant case we can't identify uh + + + align:start position:0% +multivariant case we can't identify uh +the a particular parameter if we have a + + align:start position:0% +the a particular parameter if we have a + + + align:start position:0% +the a particular parameter if we have a +regressor that doesn't have positive + + align:start position:0% +regressor that doesn't have positive + + + align:start position:0% +regressor that doesn't have positive +sample variation so all of our + + align:start position:0% +sample variation so all of our + + + align:start position:0% +sample variation so all of our +regressors have to have positive sample + + align:start position:0% +regressors have to have positive sample + + + align:start position:0% +regressors have to have positive sample +variation and then the third one and + + align:start position:0% +variation and then the third one and + + + align:start position:0% +variation and then the third one and +this is the one that actually trips + + align:start position:0% +this is the one that actually trips + + + align:start position:0% +this is the one that actually trips +people up sometimes is that we can't + + align:start position:0% +people up sometimes is that we can't + + + align:start position:0% +people up sometimes is that we can't +have any regressors that are linear + + align:start position:0% +have any regressors that are linear + + + align:start position:0% +have any regressors that are linear +functions of one or more other + + align:start position:0% +functions of one or more other + + + align:start position:0% +functions of one or more other +regressors okay and in Matrix notation + + align:start position:0% +regressors okay and in Matrix notation + + + align:start position:0% +regressors okay and in Matrix notation +that's just uh that's another way to say + + align:start position:0% +that's just uh that's another way to say + + + align:start position:0% +that's just uh that's another way to say +that is the regressors are linearly + + align:start position:0% +that is the regressors are linearly + + + align:start position:0% +that is the regressors are linearly +independent okay and that is turns out + + align:start position:0% +independent okay and that is turns out + + + align:start position:0% +independent okay and that is turns out +to be equivalent to X Prime X being + + align:start position:0% +to be equivalent to X Prime X being + + + align:start position:0% +to be equivalent to X Prime X being +invertible yep you give an example of + + align:start position:0% +invertible yep you give an example of + + + align:start position:0% +invertible yep you give an example of +that I will give two examples in + + align:start position:0% +that I will give two examples in + + + align:start position:0% +that I will give two examples in +fact okay so here is one example let's + + align:start position:0% +fact okay so here is one example let's + + + align:start position:0% +fact okay so here is one example let's +suppose let's imagine a case where we + + align:start position:0% +suppose let's imagine a case where we + + + align:start position:0% +suppose let's imagine a case where we +want to estimate the effect of schooling + + align:start position:0% +want to estimate the effect of schooling + + + align:start position:0% +want to estimate the effect of schooling +work experience and age on salary okay + + align:start position:0% +work experience and age on salary okay + + + align:start position:0% +work experience and age on salary okay +and we have individual level data so we + + align:start position:0% +and we have individual level data so we + + + align:start position:0% +and we have individual level data so we +have a we have sort of a data set we + + align:start position:0% +have a we have sort of a data set we + + + align:start position:0% +have a we have sort of a data set we +have a bunch of different salaries and + + align:start position:0% +have a bunch of different salaries and + + + align:start position:0% +have a bunch of different salaries and +then we also have each person's years of + + align:start position:0% +then we also have each person's years of + + + align:start position:0% +then we also have each person's years of +schooling each person's years of work + + align:start position:0% +schooling each person's years of work + + + align:start position:0% +schooling each person's years of work +experience each person's age and maybe + + align:start position:0% +experience each person's age and maybe + + + align:start position:0% +experience each person's age and maybe +some other stuff too doesn't matter well + + align:start position:0% +some other stuff too doesn't matter well + + + align:start position:0% +some other stuff too doesn't matter well +it could be in our particular sample + + align:start position:0% +it could be in our particular sample + + + align:start position:0% +it could be in our particular sample +quite possible that everyone in our + + align:start position:0% +quite possible that everyone in our + + + align:start position:0% +quite possible that everyone in our +sample started school at age six went to + + align:start position:0% +sample started school at age six went to + + + align:start position:0% +sample started school at age six went to +school until here or she finished school + + align:start position:0% +school until here or she finished school + + + align:start position:0% +school until here or she finished school +and then started + + align:start position:0% +and then started + + + align:start position:0% +and then started +working wouldn't be crazy if that + + align:start position:0% +working wouldn't be crazy if that + + + align:start position:0% +working wouldn't be crazy if that +happened well if in fact that was the + + align:start position:0% +happened well if in fact that was the + + + align:start position:0% +happened well if in fact that was the +case then the years of schooling plus + + align:start position:0% +case then the years of schooling plus + + + align:start position:0% +case then the years of schooling plus +the years of work experience plus six is + + align:start position:0% +the years of work experience plus six is + + + align:start position:0% +the years of work experience plus six is +equal to the + + align:start position:0% + + + + align:start position:0% + +age okay so if that's the case we can't + + align:start position:0% +age okay so if that's the case we can't + + + align:start position:0% +age okay so if that's the case we can't +estimate this regression equation + + align:start position:0% +estimate this regression equation + + + align:start position:0% +estimate this regression equation +and that makes it sort of makes logical + + align:start position:0% +and that makes it sort of makes logical + + + align:start position:0% +and that makes it sort of makes logical +sense too in the sense that I if there's + + align:start position:0% +sense too in the sense that I if there's + + + align:start position:0% +sense too in the sense that I if there's +no there's nothing that helps + + align:start position:0% +no there's nothing that helps + + + align:start position:0% +no there's nothing that helps +us separately identify what the effect + + align:start position:0% +us separately identify what the effect + + + align:start position:0% +us separately identify what the effect +of schooling and work experience and age + + align:start position:0% +of schooling and work experience and age + + + align:start position:0% +of schooling and work experience and age +are there's nothing that that no + + align:start position:0% +are there's nothing that that no + + + align:start position:0% +are there's nothing that that no +variation that allows us to separately + + align:start position:0% +variation that allows us to separately + + + align:start position:0% +variation that allows us to separately +figure out the effects of all three of + + align:start position:0% +figure out the effects of all three of + + + align:start position:0% +figure out the effects of all three of +those if in fact they're collinear in + + align:start position:0% +those if in fact they're collinear in + + + align:start position:0% +those if in fact they're collinear in +our + + align:start position:0% +our + + + align:start position:0% +our +sample Okay so we just we can't estimate + + align:start position:0% +sample Okay so we just we can't estimate + + + align:start position:0% +sample Okay so we just we can't estimate +such a model is that clear so you would + + align:start position:0% +such a model is that clear so you would + + + align:start position:0% +such a model is that clear so you would +drop a regressor exactly you have to + + align:start position:0% +drop a regressor exactly you have to + + + align:start position:0% +drop a regressor exactly you have to +drop one of the + + align:start position:0% + + + + align:start position:0% + +regressors yeah does this make + + align:start position:0% +regressors yeah does this make + + + align:start position:0% +regressors yeah does this make +sense yes drop AG + + align:start position:0% +sense yes drop AG + + + align:start position:0% +sense yes drop AG +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +still if you drop age it still wouldn't + + align:start position:0% +still if you drop age it still wouldn't + + + align:start position:0% +still if you drop age it still wouldn't +work + + align:start position:0% +work + + + align:start position:0% +work +yes it it would uh the it wouldn't work + + align:start position:0% +yes it it would uh the it wouldn't work + + + align:start position:0% +yes it it would uh the it wouldn't work +if everyone went to school until age + + align:start position:0% +if everyone went to school until age + + + align:start position:0% +if everyone went to school until age +18 so so it so we still need we would + + align:start position:0% +18 so so it so we still need we would + + + align:start position:0% +18 so so it so we still need we would +still need to have uh we couldn't have a + + align:start position:0% +still need to have uh we couldn't have a + + + align:start position:0% +still need to have uh we couldn't have a +a perfect linear relationship between um + + align:start position:0% +a perfect linear relationship between um + + + align:start position:0% +a perfect linear relationship between um +you know sort of number of years of + + align:start position:0% +you know sort of number of years of + + + align:start position:0% +you know sort of number of years of +schooling well actually that wouldn't be + + align:start position:0% +schooling well actually that wouldn't be + + + align:start position:0% +schooling well actually that wouldn't be +a perfect line that would just be no + + align:start position:0% +a perfect line that would just be no + + + align:start position:0% +a perfect line that would just be no +sample variation in years of + + align:start position:0% +sample variation in years of + + + align:start position:0% +sample variation in years of +schooling but if we did have if some + + align:start position:0% +schooling but if we did have if some + + + align:start position:0% +schooling but if we did have if some +people went to school until age 18 and + + align:start position:0% +people went to school until age 18 and + + + align:start position:0% +people went to school until age 18 and +some people went till age 20 and some + + align:start position:0% +some people went till age 20 and some + + + align:start position:0% +some people went till age 20 and some +went till age 25 then then if we dropped + + align:start position:0% +went till age 25 then then if we dropped + + + align:start position:0% +went till age 25 then then if we dropped +age from this regression and then we + + align:start position:0% +age from this regression and then we + + + align:start position:0% +age from this regression and then we +could estimate + + align:start position:0% +could estimate + + + align:start position:0% +could estimate +it we say that this is uh that why this + + align:start position:0% +it we say that this is uh that why this + + + align:start position:0% +it we say that this is uh that why this +doesn't hold is that if we took X1 X2 + + align:start position:0% +doesn't hold is that if we took X1 X2 + + + align:start position:0% +doesn't hold is that if we took X1 X2 +and X3 we could get values of beta 1 + + align:start position:0% +and X3 we could get values of beta 1 + + + align:start position:0% +and X3 we could get values of beta 1 +beta 2 and all of these which would + + align:start position:0% +beta 2 and all of these which would + + + align:start position:0% +beta 2 and all of these which would +essentially make y 0 so 1 1 and minus + + align:start position:0% +essentially make y 0 so 1 1 and minus + + + align:start position:0% +essentially make y 0 so 1 1 and minus +one for example so then this equation + + align:start position:0% +one for example so then this equation + + + align:start position:0% +one for example so then this equation +would hold two and then y would be zero + + align:start position:0% +would hold two and then y would be zero + + + align:start position:0% +would hold two and then y would be zero +in that case I don't so that's not the + + align:start position:0% +in that case I don't so that's not the + + + align:start position:0% +in that case I don't so that's not the +intuition I have um it that may be + + align:start position:0% +intuition I have um it that may be + + + align:start position:0% +intuition I have um it that may be +correct in some way but uh that's + + align:start position:0% +correct in some way but uh that's + + + align:start position:0% +correct in some way but uh that's +certainly not the intuition I have I + + align:start position:0% +certainly not the intuition I have I + + + align:start position:0% +certainly not the intuition I have I +mean I guess I would just say that my + + align:start position:0% +mean I guess I would just say that my + + + align:start position:0% +mean I guess I would just say that my +intuition is just that uh you know you + + align:start position:0% +intuition is just that uh you know you + + + align:start position:0% +intuition is just that uh you know you +can't we don't have any variation to + + align:start position:0% +can't we don't have any variation to + + + align:start position:0% +can't we don't have any variation to +separately identify the the effects of + + align:start position:0% +separately identify the the effects of + + + align:start position:0% +separately identify the the effects of +these three things if they're perfectly + + align:start position:0% +these three things if they're perfectly + + + align:start position:0% +these three things if they're perfectly +uh linearly associated with one another + + align:start position:0% +uh linearly associated with one another + + + align:start position:0% +uh linearly associated with one another +yes so what if the two regressor are + + align:start position:0% +yes so what if the two regressor are + + + align:start position:0% +yes so what if the two regressor are +somewh related U but they are not + + align:start position:0% +somewh related U but they are not + + + align:start position:0% +somewh related U but they are not +perfectly Rel relationship so that's an + + align:start position:0% +perfectly Rel relationship so that's an + + + align:start position:0% +perfectly Rel relationship so that's an +excellent question so the question was + + align:start position:0% +excellent question so the question was + + + align:start position:0% +excellent question so the question was +what if they are uh closely related so + + align:start position:0% +what if they are uh closely related so + + + align:start position:0% +what if they are uh closely related so +maybe this doesn't quite hold in our + + align:start position:0% +maybe this doesn't quite hold in our + + + align:start position:0% +maybe this doesn't quite hold in our +sample but it comes close to holding + + align:start position:0% +sample but it comes close to holding + + + align:start position:0% +sample but it comes close to holding +like we had a few people who went to + + align:start position:0% +like we had a few people who went to + + + align:start position:0% +like we had a few people who went to +school at age five instead of age six + + align:start position:0% +school at age five instead of age six + + + align:start position:0% +school at age five instead of age six +and we had like a couple people who took + + align:start position:0% +and we had like a couple people who took + + + align:start position:0% +and we had like a couple people who took +a year off and didn't work so so this + + align:start position:0% +a year off and didn't work so so this + + + align:start position:0% +a year off and didn't work so so this +linear relationship is close to holding + + align:start position:0% +linear relationship is close to holding + + + align:start position:0% +linear relationship is close to holding +but not quite that's something that + + align:start position:0% +but not quite that's something that + + + align:start position:0% +but not quite that's something that +Esther might be able to talk about next + + align:start position:0% +Esther might be able to talk about next + + + align:start position:0% +Esther might be able to talk about next +time I'm not sure so basically in that + + align:start position:0% +time I'm not sure so basically in that + + + align:start position:0% +time I'm not sure so basically in that +case you + + align:start position:0% +case you + + + align:start position:0% +case you +can maybe maybe not but but anyhow I + + align:start position:0% +can maybe maybe not but but anyhow I + + + align:start position:0% +can maybe maybe not but but anyhow I +I'll I'll tell you the answer in that + + align:start position:0% +I'll I'll tell you the answer in that + + + align:start position:0% +I'll I'll tell you the answer in that +case you can estimate this equation but + + align:start position:0% +case you can estimate this equation but + + + align:start position:0% +case you can estimate this equation but +you you end up having you end up sort of + + align:start position:0% +you you end up having you end up sort of + + + align:start position:0% +you you end up having you end up sort of +having trouble separately identifying + + align:start position:0% +having trouble separately identifying + + + align:start position:0% +having trouble separately identifying +the coefficients on these variables on + + align:start position:0% +the coefficients on these variables on + + + align:start position:0% +the coefficients on these variables on +these three variables and in fact + + align:start position:0% +these three variables and in fact + + + align:start position:0% +these three variables and in fact +they're going to be coefficients that + + align:start position:0% +they're going to be coefficients that + + + align:start position:0% +they're going to be coefficients that +have very that your estimator is going + + align:start position:0% +have very that your estimator is going + + + align:start position:0% +have very that your estimator is going +to be a very high variance estimator and + + align:start position:0% +to be a very high variance estimator and + + + align:start position:0% +to be a very high variance estimator and +so in that case what you might want to + + align:start position:0% +so in that case what you might want to + + + align:start position:0% +so in that case what you might want to +do is still drop one of them that's + + align:start position:0% +do is still drop one of them that's + + + align:start position:0% +do is still drop one of them that's +going to give you much lower variance + + align:start position:0% +going to give you much lower variance + + + align:start position:0% +going to give you much lower variance +estimators for the remaining two it's + + align:start position:0% +estimators for the remaining two it's + + + align:start position:0% +estimators for the remaining two it's +going to introduce a little bit of bias + + align:start position:0% +going to introduce a little bit of bias + + + align:start position:0% +going to introduce a little bit of bias +if that regressor belongs in there it's + + align:start position:0% +if that regressor belongs in there it's + + + align:start position:0% +if that regressor belongs in there it's +going to introduce a little bit of bias + + align:start position:0% +going to introduce a little bit of bias + + + align:start position:0% +going to introduce a little bit of bias +but you might be willing to accept that + + align:start position:0% +but you might be willing to accept that + + + align:start position:0% +but you might be willing to accept that +bias to have much lower variance + + align:start position:0% +bias to have much lower variance + + + align:start position:0% +bias to have much lower variance +estimators so + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +question um what if you have a lar data + + align:start position:0% +question um what if you have a lar data + + + align:start position:0% +question um what if you have a lar data +set with a lot of variables and and we + + align:start position:0% +set with a lot of variables and and we + + + align:start position:0% +set with a lot of variables and and we +don't know that there are regression in + + align:start position:0% +don't know that there are regression in + + + align:start position:0% +don't know that there are regression in +there that do have + + align:start position:0% +there that do have + + + align:start position:0% +there that do have +what are the things + + align:start position:0% +what are the things + + + align:start position:0% +what are the things +that like this could be causing problems + + align:start position:0% +that like this could be causing problems + + + align:start position:0% +that like this could be causing problems +in my analysis or yeah so so first of + + align:start position:0% +in my analysis or yeah so so first of + + + align:start position:0% +in my analysis or yeah so so first of +all if you if I tried to run this + + align:start position:0% +all if you if I tried to run this + + + align:start position:0% +all if you if I tried to run this +regression and this linear relationship + + align:start position:0% +regression and this linear relationship + + + align:start position:0% +regression and this linear relationship +existed in my data set R would throw up + + align:start position:0% +existed in my data set R would throw up + + + align:start position:0% +existed in my data set R would throw up +its hands and say you can't do that okay + + align:start position:0% +its hands and say you can't do that okay + + + align:start position:0% +its hands and say you can't do that okay +so I I can't even do it so you you would + + align:start position:0% +so I I can't even do it so you you would + + + align:start position:0% +so I I can't even do it so you you would +you would find that out if this + + align:start position:0% +you would find that out if this + + + align:start position:0% +you would find that out if this +relationship didn't quite exist it was + + align:start position:0% +relationship didn't quite exist it was + + + align:start position:0% +relationship didn't quite exist it was +close to existing in the data set but + + align:start position:0% +close to existing in the data set but + + + align:start position:0% +close to existing in the data set but +not quite R would go ahead and give you + + align:start position:0% +not quite R would go ahead and give you + + + align:start position:0% +not quite R would go ahead and give you +the results of this but the one thing + + align:start position:0% +the results of this but the one thing + + + align:start position:0% +the results of this but the one thing +that you could do is you could sort of + + align:start position:0% +that you could do is you could sort of + + + align:start position:0% +that you could do is you could sort of +uh compute the correlation coefficients + + align:start position:0% +uh compute the correlation coefficients + + + align:start position:0% +uh compute the correlation coefficients +for all of your regressors before you + + align:start position:0% +for all of your regressors before you + + + align:start position:0% +for all of your regressors before you +run the regression and see if any are + + align:start position:0% +run the regression and see if any are + + + align:start position:0% +run the regression and see if any are +really highly correlated that doesn't + + align:start position:0% +really highly correlated that doesn't + + + align:start position:0% +really highly correlated that doesn't +wouldn't necessarily pick up a linear + + align:start position:0% +wouldn't necessarily pick up a linear + + + align:start position:0% +wouldn't necessarily pick up a linear +relationship like this but the other + + align:start position:0% +relationship like this but the other + + + align:start position:0% +relationship like this but the other +thing you could do is after you run the + + align:start position:0% +thing you could do is after you run the + + + align:start position:0% +thing you could do is after you run the +regression if you have really large + + align:start position:0% +regression if you have really large + + + align:start position:0% +regression if you have really large +standard errors that could be a signal + + align:start position:0% +standard errors that could be a signal + + + align:start position:0% +standard errors that could be a signal +to you that uh you could have this this + + align:start position:0% +to you that uh you could have this this + + + align:start position:0% +to you that uh you could have this this +uh situation that's close to perfect + + align:start position:0% +uh situation that's close to perfect + + + align:start position:0% +uh situation that's close to perfect +colinearity yes so if we had two regress + + align:start position:0% +colinearity yes so if we had two regress + + + align:start position:0% +colinearity yes so if we had two regress +X1 and X2 could we use the ratio X1 by + + align:start position:0% +X1 and X2 could we use the ratio X1 by + + + align:start position:0% +X1 and X2 could we use the ratio X1 by +X2 as a thir regress as a or would that + + align:start position:0% +X2 as a thir regress as a or would that + + + align:start position:0% +X2 as a thir regress as a or would that +also so uh so that you could sort of you + + align:start position:0% +also so uh so that you could sort of you + + + align:start position:0% +also so uh so that you could sort of you +know that wouldn't induce this sort of + + align:start position:0% +know that wouldn't induce this sort of + + + align:start position:0% +know that wouldn't induce this sort of +perfect linear um you know perfect + + align:start position:0% +perfect linear um you know perfect + + + align:start position:0% +perfect linear um you know perfect +linear cinear ity problem you could you + + align:start position:0% +linear cinear ity problem you could you + + + align:start position:0% +linear cinear ity problem you could you +might not want to do it for other + + align:start position:0% +might not want to do it for other + + + align:start position:0% +might not want to do it for other +reasons but + + align:start position:0% + + + + align:start position:0% + +yeah question on if you had many + + align:start position:0% +yeah question on if you had many + + + align:start position:0% +yeah question on if you had many +regressor and you didn't + + align:start position:0% +regressor and you didn't + + + align:start position:0% +regressor and you didn't +know which one to pick sort of go away + + align:start position:0% +know which one to pick sort of go away + + + align:start position:0% +know which one to pick sort of go away +from traditional eometric it becomes + + align:start position:0% +from traditional eometric it becomes + + + align:start position:0% +from traditional eometric it becomes +then this is from what we're going to + + align:start position:0% +then this is from what we're going to + + + align:start position:0% +then this is from what we're going to +talk about when we talk about machine + + align:start position:0% +talk about when we talk about machine + + + align:start position:0% +talk about when we talk about machine +learning if you really don't want to + + align:start position:0% +learning if you really don't want to + + + align:start position:0% +learning if you really don't want to +traditional eometric assumes you have a + + align:start position:0% +traditional eometric assumes you have a + + + align:start position:0% +traditional eometric assumes you have a +model that you are trying to test so you + + align:start position:0% +model that you are trying to test so you + + + align:start position:0% +model that you are trying to test so you +don't go on a g fishing Expedition if + + align:start position:0% +don't go on a g fishing Expedition if + + + align:start position:0% +don't go on a g fishing Expedition if +you want to go on a giant fishing + + align:start position:0% +you want to go on a giant fishing + + + align:start position:0% +you want to go on a giant fishing +Expedition there are there are there are + + align:start position:0% +Expedition there are there are there are + + + align:start position:0% +Expedition there are there are there are +techniques for that that's F that's what + + align:start position:0% +techniques for that that's F that's what + + + align:start position:0% +techniques for that that's F that's what +we are going to + + align:start position:0% + + + + align:start position:0% + +introduce good okay so that's one + + align:start position:0% +introduce good okay so that's one + + + align:start position:0% +introduce good okay so that's one +example a second example of this perfect + + align:start position:0% +example a second example of this perfect + + + align:start position:0% +example a second example of this perfect +multicolinearity + + align:start position:0% +multicolinearity + + + align:start position:0% +multicolinearity +uh is um and one that sort of + + align:start position:0% +uh is um and one that sort of + + + align:start position:0% +uh is um and one that sort of +researchers run a fowl of all the time + + align:start position:0% +researchers run a fowl of all the time + + + align:start position:0% +researchers run a fowl of all the time +um it is uh when + + align:start position:0% +um it is uh when + + + align:start position:0% +um it is uh when +they use dummy variables to indicate say + + align:start position:0% +they use dummy variables to indicate say + + + align:start position:0% +they use dummy variables to indicate say +observations falling into um exhaustive + + align:start position:0% +observations falling into um exhaustive + + + align:start position:0% +observations falling into um exhaustive +and mutually exclusive uh set of classes + + align:start position:0% +and mutually exclusive uh set of classes + + + align:start position:0% +and mutually exclusive uh set of classes +so here's an example let's suppose I + + align:start position:0% +so here's an example let's suppose I + + + align:start position:0% +so here's an example let's suppose I +have a data set let's say I go um you + + align:start position:0% +have a data set let's say I go um you + + + align:start position:0% +have a data set let's say I go um you +know sort of talk to all my friends in + + align:start position:0% +know sort of talk to all my friends in + + + align:start position:0% +know sort of talk to all my friends in +the dorm to collect my data set for 1431 + + align:start position:0% +the dorm to collect my data set for 1431 + + + align:start position:0% +the dorm to collect my data set for 1431 +and I ask them what pets they have at + + align:start position:0% +and I ask them what pets they have at + + + align:start position:0% +and I ask them what pets they have at +home and um let's say all of them have + + align:start position:0% +home and um let's say all of them have + + + align:start position:0% +home and um let's say all of them have +pets we could have a category for no pet + + align:start position:0% +pets we could have a category for no pet + + + align:start position:0% +pets we could have a category for no pet +as well but anyhow let's say all of them + + align:start position:0% +as well but anyhow let's say all of them + + + align:start position:0% +as well but anyhow let's say all of them +have pets but they either either have a + + align:start position:0% +have pets but they either either have a + + + align:start position:0% +have pets but they either either have a +cat a dog or a fish and so then I create + + align:start position:0% +cat a dog or a fish and so then I create + + + align:start position:0% +cat a dog or a fish and so then I create +three different dummy variables one is + + align:start position:0% +three different dummy variables one is + + + align:start position:0% +three different dummy variables one is +equal to one if they have a cat and zero + + align:start position:0% +equal to one if they have a cat and zero + + + align:start position:0% +equal to one if they have a cat and zero +otherwise one is equal to one if they + + align:start position:0% +otherwise one is equal to one if they + + + align:start position:0% +otherwise one is equal to one if they +have a dog and zero otherwise and one is + + align:start position:0% +have a dog and zero otherwise and one is + + + align:start position:0% +have a dog and zero otherwise and one is +equal to one if they have a fish and + + align:start position:0% +equal to one if they have a fish and + + + align:start position:0% +equal to one if they have a fish and +zero otherwise and everyone has exactly + + align:start position:0% +zero otherwise and everyone has exactly + + + align:start position:0% +zero otherwise and everyone has exactly +one of those pets okay I cannot include + + align:start position:0% +one of those pets okay I cannot include + + + align:start position:0% +one of those pets okay I cannot include +all three of those dummy variables in + + align:start position:0% +all three of those dummy variables in + + + align:start position:0% +all three of those dummy variables in +the uh regression because if we add up + + align:start position:0% +the uh regression because if we add up + + + align:start position:0% +the uh regression because if we add up +those three dummy variables we get a + + align:start position:0% +those three dummy variables we get a + + + align:start position:0% +those three dummy variables we get a +column of ones and that's perfectly + + align:start position:0% +column of ones and that's perfectly + + + align:start position:0% +column of ones and that's perfectly +collinear with our uh column of ones + + align:start position:0% +collinear with our uh column of ones + + + align:start position:0% +collinear with our uh column of ones +that allows us to estimate the um The + + align:start position:0% +that allows us to estimate the um The + + + align:start position:0% +that allows us to estimate the um The +Intercept okay now it there there are + + align:start position:0% +Intercept okay now it there there are + + + align:start position:0% +Intercept okay now it there there are +sort of other ways you you can in fact + + align:start position:0% +sort of other ways you you can in fact + + + align:start position:0% +sort of other ways you you can in fact +um it you can in fact decide to include + + align:start position:0% +um it you can in fact decide to include + + + align:start position:0% +um it you can in fact decide to include +all three dummy variables and not + + align:start position:0% +all three dummy variables and not + + + align:start position:0% +all three dummy variables and not +include an intercept not estimate an + + align:start position:0% +include an intercept not estimate an + + + align:start position:0% +include an intercept not estimate an +Intercept in this regression it's + + align:start position:0% +Intercept in this regression it's + + + align:start position:0% +Intercept in this regression it's +entirely equivalent it would be a little + + align:start position:0% +entirely equivalent it would be a little + + + align:start position:0% +entirely equivalent it would be a little +troubling if it wasn't equivalent but it + + align:start position:0% +troubling if it wasn't equivalent but it + + + align:start position:0% +troubling if it wasn't equivalent but it +isn't in fact entirely equivalent it's + + align:start position:0% +isn't in fact entirely equivalent it's + + + align:start position:0% +isn't in fact entirely equivalent it's +just you have to interpret the + + align:start position:0% +just you have to interpret the + + + align:start position:0% +just you have to interpret the +coefficient estimates a different way + + align:start position:0% +coefficient estimates a different way + + + align:start position:0% +coefficient estimates a different way +but you can't have both an Intercept in + + align:start position:0% +but you can't have both an Intercept in + + + align:start position:0% +but you can't have both an Intercept in +your regression and a set of dummy + + align:start position:0% +your regression and a set of dummy + + + align:start position:0% +your regression and a set of dummy +variables that are a full set of + + align:start position:0% +variables that are a full set of + + + align:start position:0% +variables that are a full set of +exhaustive and mutually exclusive + + align:start position:0% +exhaustive and mutually exclusive + + + align:start position:0% +exhaustive and mutually exclusive +classes Okay and like I said R will not + + align:start position:0% +classes Okay and like I said R will not + + + align:start position:0% +classes Okay and like I said R will not +let you do this + + align:start position:0% + + + + align:start position:0% + +anyhow okay so now the second um + + align:start position:0% +anyhow okay so now the second um + + + align:start position:0% +anyhow okay so now the second um +assumption or second yes does it change + + align:start position:0% +assumption or second yes does it change + + + align:start position:0% +assumption or second yes does it change +anything depending on which one + + align:start position:0% +anything depending on which one + + + align:start position:0% +anything depending on which one +it only changes the interpretation so + + align:start position:0% +it only changes the interpretation so + + + align:start position:0% +it only changes the interpretation so +basically uh I yeah I think I'll I'll + + align:start position:0% +basically uh I yeah I think I'll I'll + + + align:start position:0% +basically uh I yeah I think I'll I'll +leave I'll leave that question for + + align:start position:0% +leave I'll leave that question for + + + align:start position:0% +leave I'll leave that question for +Esther uh because she will be giving + + align:start position:0% +Esther uh because she will be giving + + + align:start position:0% +Esther uh because she will be giving +examples of uh you know how to use dummy + + align:start position:0% +examples of uh you know how to use dummy + + + align:start position:0% +examples of uh you know how to use dummy +variables in regressions and how to + + align:start position:0% +variables in regressions and how to + + + align:start position:0% +variables in regressions and how to +interpret the coefficients so we'll + + align:start position:0% +interpret the coefficients so we'll + + + align:start position:0% +interpret the coefficients so we'll +leave that to + + align:start position:0% +leave that to + + + align:start position:0% +leave that to +later okay um so then the second + + align:start position:0% +later okay um so then the second + + + align:start position:0% +later okay um so then the second +assumption was about the error of + + align:start position:0% +assumption was about the error of + + + align:start position:0% +assumption was about the error of +behavior and as I said before the these + + align:start position:0% +behavior and as I said before the these + + + align:start position:0% +behavior and as I said before the these +assumptions aren't different for the + + align:start position:0% +assumptions aren't different for the + + + align:start position:0% +assumptions aren't different for the +mult variant model it's just that uh + + align:start position:0% +mult variant model it's just that uh + + + align:start position:0% +mult variant model it's just that uh +I've expressed them using Matrix + + align:start position:0% +I've expressed them using Matrix + + + align:start position:0% +I've expressed them using Matrix +notation so let me just sort of go + + align:start position:0% +notation so let me just sort of go + + + align:start position:0% +notation so let me just sort of go +through um these exactly the same + + align:start position:0% +through um these exactly the same + + + align:start position:0% +through um these exactly the same +assumptions we saw in the B variant + + align:start position:0% +assumptions we saw in the B variant + + + align:start position:0% +assumptions we saw in the B variant +model here I'm using Matrix notation so + + align:start position:0% +model here I'm using Matrix notation so + + + align:start position:0% +model here I'm using Matrix notation so +I'll just go through and show you what + + align:start position:0% +I'll just go through and show you what + + + align:start position:0% +I'll just go through and show you what +what they mean so what I uh so first of + + align:start position:0% +what they mean so what I uh so first of + + + align:start position:0% +what they mean so what I uh so first of +all + + align:start position:0% +all + + + align:start position:0% +all +expectation of um Epsilon is equal to + + align:start position:0% +expectation of um Epsilon is equal to + + + align:start position:0% +expectation of um Epsilon is equal to +zero Epsilon is a vector um and so it's + + align:start position:0% +zero Epsilon is a vector um and so it's + + + align:start position:0% +zero Epsilon is a vector um and so it's +just equal to you know a vector of zeros + + align:start position:0% +just equal to you know a vector of zeros + + + align:start position:0% +just equal to you know a vector of zeros +and then for some reason we often write + + align:start position:0% +and then for some reason we often write + + + align:start position:0% +and then for some reason we often write +that the um instead of writing the + + align:start position:0% +that the um instead of writing the + + + align:start position:0% +that the um instead of writing the +Assumption as the covariance Matrix of + + align:start position:0% +Assumption as the covariance Matrix of + + + align:start position:0% +Assumption as the covariance Matrix of +Epsilon equals Sigma s time the identity + + align:start position:0% +Epsilon equals Sigma s time the identity + + + align:start position:0% +Epsilon equals Sigma s time the identity +the N byn identity Matrix we write it as + + align:start position:0% +the N byn identity Matrix we write it as + + + align:start position:0% +the N byn identity Matrix we write it as +the expectation of Epsilon Epsilon + + align:start position:0% +the expectation of Epsilon Epsilon + + + align:start position:0% +the expectation of Epsilon Epsilon +transpose is equal to that well it turns + + align:start position:0% +transpose is equal to that well it turns + + + align:start position:0% +transpose is equal to that well it turns +out because the expectation of Epsilon + + align:start position:0% +out because the expectation of Epsilon + + + align:start position:0% +out because the expectation of Epsilon +is is identically equal to zero this + + align:start position:0% +is is identically equal to zero this + + + align:start position:0% +is is identically equal to zero this +Matrix is equal to this Matrix you can + + align:start position:0% +Matrix is equal to this Matrix you can + + + align:start position:0% +Matrix is equal to this Matrix you can +just do you know you can sort of do the + + align:start position:0% +just do you know you can sort of do the + + + align:start position:0% +just do you know you can sort of do the +calculations it's just two lines to + + align:start position:0% +calculations it's just two lines to + + + align:start position:0% +calculations it's just two lines to +convince yourself but I could have + + align:start position:0% +convince yourself but I could have + + + align:start position:0% +convince yourself but I could have +expressed this assumption by just saying + + align:start position:0% +expressed this assumption by just saying + + + align:start position:0% +expressed this assumption by just saying +that this Matrix is equal to this okay + + align:start position:0% +that this Matrix is equal to this okay + + + align:start position:0% +that this Matrix is equal to this okay +but for whatever reason we often see it + + align:start position:0% +but for whatever reason we often see it + + + align:start position:0% +but for whatever reason we often see it +written as this Matrix is equal to this + + align:start position:0% +written as this Matrix is equal to this + + + align:start position:0% +written as this Matrix is equal to this +same thing + + align:start position:0% +same thing + + + align:start position:0% +same thing +okay does everyone understand + + align:start position:0% +okay does everyone understand + + + align:start position:0% +okay does everyone understand +why this Matrix equaling this is exactly + + align:start position:0% +why this Matrix equaling this is exactly + + + align:start position:0% +why this Matrix equaling this is exactly +the same assumptions we saw + + align:start position:0% +the same assumptions we saw + + + align:start position:0% +the same assumptions we saw +before so this Matrix is just simply the + + align:start position:0% +before so this Matrix is just simply the + + + align:start position:0% +before so this Matrix is just simply the +the a matrix containing the variances of + + align:start position:0% +the a matrix containing the variances of + + + align:start position:0% +the a matrix containing the variances of +the epsilons on the diagonal so remember + + align:start position:0% +the epsilons on the diagonal so remember + + + align:start position:0% +the epsilons on the diagonal so remember +before we said each Epsilon had variance + + align:start position:0% +before we said each Epsilon had variance + + + align:start position:0% +before we said each Epsilon had variance +Sigma squ that was our + + align:start position:0% +Sigma squ that was our + + + align:start position:0% +Sigma squ that was our +homoscedasticity assumption so each + + align:start position:0% +homoscedasticity assumption so each + + + align:start position:0% +homoscedasticity assumption so each +variance is Sigma squar and then all the + + align:start position:0% +variance is Sigma squar and then all the + + + align:start position:0% +variance is Sigma squar and then all the +co-variances were zero that was our no + + align:start position:0% +co-variances were zero that was our no + + + align:start position:0% +co-variances were zero that was our no +serial correlation assumption all all of + + align:start position:0% +serial correlation assumption all all of + + + align:start position:0% +serial correlation assumption all all of +the off diagonals here are zero + + align:start position:0% +the off diagonals here are zero + + + align:start position:0% +the off diagonals here are zero +okay so it's the same thing just in + + align:start position:0% +okay so it's the same thing just in + + + align:start position:0% +okay so it's the same thing just in +Matrix + + align:start position:0% + + + + align:start position:0% + +form + + align:start position:0% +form + + + align:start position:0% +form +okay and yeah I guess I think I said + + align:start position:0% +okay and yeah I guess I think I said + + + align:start position:0% +okay and yeah I guess I think I said +this verbally but this this thing is + + align:start position:0% +this verbally but this this thing is + + + align:start position:0% +this verbally but this this thing is +denoted coari of Epsilon and it's called + + align:start position:0% +denoted coari of Epsilon and it's called + + + align:start position:0% +denoted coari of Epsilon and it's called +the variance coari Matrix of + + align:start position:0% + + + + align:start position:0% + +Epsilon okay fine we've got this linear + + align:start position:0% +Epsilon okay fine we've got this linear + + + align:start position:0% +Epsilon okay fine we've got this linear +model we've got the these assumptions + + align:start position:0% +model we've got the these assumptions + + + align:start position:0% +model we've got the these assumptions +just like four we're going to now ask + + align:start position:0% +just like four we're going to now ask + + + align:start position:0% +just like four we're going to now ask +the question how do we get beta hat and + + align:start position:0% +the question how do we get beta hat and + + + align:start position:0% +the question how do we get beta hat and +what distribution does beta hat have and + + align:start position:0% +what distribution does beta hat have and + + + align:start position:0% +what distribution does beta hat have and +the answers are not going to be + + align:start position:0% +the answers are not going to be + + + align:start position:0% +the answers are not going to be +surprising but they're going to be more + + align:start position:0% +surprising but they're going to be more + + + align:start position:0% +surprising but they're going to be more +beautiful than they were last time okay + + align:start position:0% +beautiful than they were last time okay + + + align:start position:0% +beautiful than they were last time okay +so what is beta hat well it's the vector + + align:start position:0% +so what is beta hat well it's the vector + + + align:start position:0% +so what is beta hat well it's the vector +that minimizes the sum of squared errors + + align:start position:0% +that minimizes the sum of squared errors + + + align:start position:0% +that minimizes the sum of squared errors +so we've got a vector of + + align:start position:0% +so we've got a vector of + + + align:start position:0% +so we've got a vector of +residuals transpose uh or you know + + align:start position:0% +residuals transpose uh or you know + + + align:start position:0% +residuals transpose uh or you know +transpose times a vector of residuals + + align:start position:0% +transpose times a vector of residuals + + + align:start position:0% +transpose times a vector of residuals +and uh that's that's sort of uh you know + + align:start position:0% +and uh that's that's sort of uh you know + + + align:start position:0% +and uh that's that's sort of uh you know +expanded out what it looks like + + align:start position:0% +expanded out what it looks like + + + align:start position:0% +expanded out what it looks like +okay so we want to choose the beta hat + + align:start position:0% +okay so we want to choose the beta hat + + + align:start position:0% +okay so we want to choose the beta hat +that minimizes that thing so what we do + + align:start position:0% +that minimizes that thing so what we do + + + align:start position:0% +that minimizes that thing so what we do +is we take the derivative with respect + + align:start position:0% +is we take the derivative with respect + + + align:start position:0% +is we take the derivative with respect +to Beta set it equal to zero and + + align:start position:0% +to Beta set it equal to zero and + + + align:start position:0% +to Beta set it equal to zero and +obtain this okay if you're not used to + + align:start position:0% +obtain this okay if you're not used to + + + align:start position:0% +obtain this okay if you're not used to +doing calculus with vectors and matrices + + align:start position:0% +doing calculus with vectors and matrices + + + align:start position:0% +doing calculus with vectors and matrices +you can sort of in the notes that I + + align:start position:0% +you can sort of in the notes that I + + + align:start position:0% +you can sort of in the notes that I +posted online I sort of write this out + + align:start position:0% +posted online I sort of write this out + + + align:start position:0% +posted online I sort of write this out +in more detail and you can take a look + + align:start position:0% +in more detail and you can take a look + + + align:start position:0% +in more detail and you can take a look +at that if you want but basically uh we + + align:start position:0% +at that if you want but basically uh we + + + align:start position:0% +at that if you want but basically uh we +get this um this sort of equation um set + + align:start position:0% +get this um this sort of equation um set + + + align:start position:0% +get this um this sort of equation um set +equal to zero and this is going to tell + + align:start position:0% +equal to zero and this is going to tell + + + align:start position:0% +equal to zero and this is going to tell +us what the beta hat that minimizes the + + align:start position:0% +us what the beta hat that minimizes the + + + align:start position:0% +us what the beta hat that minimizes the +sum of squared residuals is we then we + + align:start position:0% +sum of squared residuals is we then we + + + align:start position:0% +sum of squared residuals is we then we +solve for beta hat the -2 we can just + + align:start position:0% +solve for beta hat the -2 we can just + + + align:start position:0% +solve for beta hat the -2 we can just +divide you know both sides by -2 and so + + align:start position:0% +divide you know both sides by -2 and so + + + align:start position:0% +divide you know both sides by -2 and so +that goes away then we write uh this + + align:start position:0% +that goes away then we write uh this + + + align:start position:0% +that goes away then we write uh this +equation is X Prime y or X transpose + + align:start position:0% +equation is X Prime y or X transpose + + + align:start position:0% +equation is X Prime y or X transpose +yals Xpose x * beta hat + + align:start position:0% +yals Xpose x * beta hat + + + align:start position:0% +yals Xpose x * beta hat +okay and then if this is + + align:start position:0% +okay and then if this is + + + align:start position:0% +okay and then if this is +invertible and remember that was one of + + align:start position:0% +invertible and remember that was one of + + + align:start position:0% +invertible and remember that was one of +our assumptions that was our + + align:start position:0% +our assumptions that was our + + + align:start position:0% +our assumptions that was our +identification assumption that that + + align:start position:0% +identification assumption that that + + + align:start position:0% +identification assumption that that +thing was invertible if that's + + align:start position:0% +thing was invertible if that's + + + align:start position:0% +thing was invertible if that's +invertible then we get that beta hat is + + align:start position:0% +invertible then we get that beta hat is + + + align:start position:0% +invertible then we get that beta hat is +just equal to X Prime X inverse X Prime + + align:start position:0% + + + + align:start position:0% + +y beautiful + + align:start position:0% + + + + align:start position:0% + +okay so I mean that was I mean that was + + align:start position:0% +okay so I mean that was I mean that was + + + align:start position:0% +okay so I mean that was I mean that was +literally the derivation of the the + + align:start position:0% +literally the derivation of the the + + + align:start position:0% +literally the derivation of the the +least squares estimators in Matrix + + align:start position:0% +least squares estimators in Matrix + + + align:start position:0% +least squares estimators in Matrix +notation if you look at my notes that + + align:start position:0% +notation if you look at my notes that + + + align:start position:0% +notation if you look at my notes that +I've posted online I mean it's just + + align:start position:0% +I've posted online I mean it's just + + + align:start position:0% +I've posted online I mean it's just +pages of algebra using that summation + + align:start position:0% +pages of algebra using that summation + + + align:start position:0% +pages of algebra using that summation +notation so this is why we love doing it + + align:start position:0% +notation so this is why we love doing it + + + align:start position:0% +notation so this is why we love doing it +in Matrix + + align:start position:0% +in Matrix + + + align:start position:0% +in Matrix +notation what do we want to know about + + align:start position:0% +notation what do we want to know about + + + align:start position:0% +notation what do we want to know about +beta hat what do we always want to know + + align:start position:0% +beta hat what do we always want to know + + + align:start position:0% +beta hat what do we always want to know +about an estimator so we can do + + align:start position:0% +about an estimator so we can do + + + align:start position:0% +about an estimator so we can do +inference it's distribution oh it's + + align:start position:0% +inference it's distribution oh it's + + + align:start position:0% +inference it's distribution oh it's +right up there + + align:start position:0% +right up there + + + align:start position:0% +right up there +okay okay fine so the expectation of + + align:start position:0% +okay okay fine so the expectation of + + + align:start position:0% +okay okay fine so the expectation of +beta hat is equal to Beta again this is + + align:start position:0% +beta hat is equal to Beta again this is + + + align:start position:0% +beta hat is equal to Beta again this is +in in Matrix notation it's very simple I + + align:start position:0% +in in Matrix notation it's very simple I + + + align:start position:0% +in in Matrix notation it's very simple I +haven't included the four lines or + + align:start position:0% +haven't included the four lines or + + + align:start position:0% +haven't included the four lines or +something like that but if you treat the + + align:start position:0% +something like that but if you treat the + + + align:start position:0% +something like that but if you treat the +X's as + + align:start position:0% +X's as + + + align:start position:0% +X's as +fixed um then that makes the sort of + + align:start position:0% +fixed um then that makes the sort of + + + align:start position:0% +fixed um then that makes the sort of +proof very simple okay they come outside + + align:start position:0% +proof very simple okay they come outside + + + align:start position:0% +proof very simple okay they come outside +the expectation operator and you + + align:start position:0% +the expectation operator and you + + + align:start position:0% +the expectation operator and you +basically just falls + + align:start position:0% +basically just falls + + + align:start position:0% +basically just falls +out so it is unbiased + + align:start position:0% +out so it is unbiased + + + align:start position:0% +out so it is unbiased +uh and the co-variance of beta hat + + align:start position:0% +uh and the co-variance of beta hat + + + align:start position:0% +uh and the co-variance of beta hat +remember this is the variance + + align:start position:0% +remember this is the variance + + + align:start position:0% +remember this is the variance +co-variance Matrix so it's the Matrix + + align:start position:0% +co-variance Matrix so it's the Matrix + + + align:start position:0% +co-variance Matrix so it's the Matrix +that has along the diagonal the + + align:start position:0% +that has along the diagonal the + + + align:start position:0% +that has along the diagonal the +variances of each of the beta hats and + + align:start position:0% +variances of each of the beta hats and + + + align:start position:0% +variances of each of the beta hats and +off the on the off diagonals the + + align:start position:0% +off the on the off diagonals the + + + align:start position:0% +off the on the off diagonals the +co-variances between them that is just + + align:start position:0% +co-variances between them that is just + + + align:start position:0% +co-variances between them that is just +equal to Sigma s time x Prime X + + align:start position:0% +equal to Sigma s time x Prime X + + + align:start position:0% +equal to Sigma s time x Prime X +inverse okay so again very elegant very + + align:start position:0% +inverse okay so again very elegant very + + + align:start position:0% +inverse okay so again very elegant very +beautiful and not too hard to show if + + align:start position:0% +beautiful and not too hard to show if + + + align:start position:0% +beautiful and not too hard to show if +you treat the X's as fixed + + align:start position:0% +you treat the X's as fixed + + + align:start position:0% +you treat the X's as fixed +and you can look on the website if + + align:start position:0% +and you can look on the website if + + + align:start position:0% +and you can look on the website if +you're + + align:start position:0% + + + + align:start position:0% + +interested and finally we often don't + + align:start position:0% +interested and finally we often don't + + + align:start position:0% +interested and finally we often don't +know what Sigma squar is for inference + + align:start position:0% +know what Sigma squar is for inference + + + align:start position:0% +know what Sigma squar is for inference +we need to know what Sigma squar is so + + align:start position:0% +we need to know what Sigma squar is so + + + align:start position:0% +we need to know what Sigma squar is so +or we need an estimate for Sigma squar + + align:start position:0% +or we need an estimate for Sigma squar + + + align:start position:0% +or we need an estimate for Sigma squar +so this is our uh this is our unbiased + + align:start position:0% +so this is our uh this is our unbiased + + + align:start position:0% +so this is our uh this is our unbiased +estimate uh for Sigma squared and as + + align:start position:0% +estimate uh for Sigma squared and as + + + align:start position:0% +estimate uh for Sigma squared and as +Esther uh uh + + align:start position:0% +Esther uh uh + + + align:start position:0% +Esther uh uh +anticipated uh here we have to subtract + + align:start position:0% +anticipated uh here we have to subtract + + + align:start position:0% +anticipated uh here we have to subtract +off a k instead of a two because instead + + align:start position:0% +off a k instead of a two because instead + + + align:start position:0% +off a k instead of a two because instead +of it being a uh byar model it's a + + align:start position:0% +of it being a uh byar model it's a + + + align:start position:0% +of it being a uh byar model it's a +Univar model or sorry multivar + + align:start position:0% + + + + align:start position:0% + +model okay and then finally if we're + + align:start position:0% +model okay and then finally if we're + + + align:start position:0% +model okay and then finally if we're +willing to impose the more strict + + align:start position:0% +willing to impose the more strict + + + align:start position:0% +willing to impose the more strict +assumption on the error distribution the + + align:start position:0% +assumption on the error distribution the + + + align:start position:0% +assumption on the error distribution the +errors are normally distributed uh then + + align:start position:0% +errors are normally distributed uh then + + + align:start position:0% +errors are normally distributed uh then +the beta hats are also normally + + align:start position:0% +the beta hats are also normally + + + align:start position:0% +the beta hats are also normally +distributed so sometimes we want to + + align:start position:0% +distributed so sometimes we want to + + + align:start position:0% +distributed so sometimes we want to +impose that sometimes we want to be less + + align:start position:0% +impose that sometimes we want to be less + + + align:start position:0% +impose that sometimes we want to be less +uh Pro + + align:start position:0% +uh Pro + + + align:start position:0% +uh Pro +descriptive okay so now finally we get + + align:start position:0% +descriptive okay so now finally we get + + + align:start position:0% +descriptive okay so now finally we get +to + + align:start position:0% +to + + + align:start position:0% +to +inference so typically in the linear + + align:start position:0% +inference so typically in the linear + + + align:start position:0% +inference so typically in the linear +model we're going to want to test + + align:start position:0% +model we're going to want to test + + + align:start position:0% +model we're going to want to test +hypotheses involving the betas that's + + align:start position:0% +hypotheses involving the betas that's + + + align:start position:0% +hypotheses involving the betas that's +where the real action is I mean I Can + + align:start position:0% +where the real action is I mean I Can + + + align:start position:0% +where the real action is I mean I Can +Dream up hypotheses involving Sigma + + align:start position:0% +Dream up hypotheses involving Sigma + + + align:start position:0% +Dream up hypotheses involving Sigma +squar and things like that and that's + + align:start position:0% +squar and things like that and that's + + + align:start position:0% +squar and things like that and that's +fine and occasionally you might want to + + align:start position:0% +fine and occasionally you might want to + + + align:start position:0% +fine and occasionally you might want to +to test a hypothesis involving Sigma squ + + align:start position:0% +to test a hypothesis involving Sigma squ + + + align:start position:0% +to test a hypothesis involving Sigma squ +but really we care about the betas + + align:start position:0% +but really we care about the betas + + + align:start position:0% +but really we care about the betas +because the betas are the parameters in + + align:start position:0% +because the betas are the parameters in + + + align:start position:0% +because the betas are the parameters in +our conditional mean function of our + + align:start position:0% +our conditional mean function of our + + + align:start position:0% +our conditional mean function of our +outcome variable and the questions that + + align:start position:0% +outcome variable and the questions that + + + align:start position:0% +outcome variable and the questions that +we usually want to answer using a linear + + align:start position:0% +we usually want to answer using a linear + + + align:start position:0% +we usually want to answer using a linear +regression are about the nature of this + + align:start position:0% +regression are about the nature of this + + + align:start position:0% +regression are about the nature of this +conditional mean function okay so + + align:start position:0% +conditional mean function okay so + + + align:start position:0% +conditional mean function okay so +sometimes we might only be interested in + + align:start position:0% +sometimes we might only be interested in + + + align:start position:0% +sometimes we might only be interested in +one of the betas other times we might + + align:start position:0% +one of the betas other times we might + + + align:start position:0% +one of the betas other times we might +want to simultaneously test hypothesis + + align:start position:0% +want to simultaneously test hypothesis + + + align:start position:0% +want to simultaneously test hypothesis +about a whole bunch of them um and as we + + align:start position:0% +about a whole bunch of them um and as we + + + align:start position:0% +about a whole bunch of them um and as we +saw in the output that I showed you last + + align:start position:0% +saw in the output that I showed you last + + + align:start position:0% +saw in the output that I showed you last +lecture uh statistical packages + + align:start position:0% +lecture uh statistical packages + + + align:start position:0% +lecture uh statistical packages +typically perform some standard tests on + + align:start position:0% +typically perform some standard tests on + + + align:start position:0% +typically perform some standard tests on +the betas for free and just report them + + align:start position:0% +the betas for free and just report them + + + align:start position:0% +the betas for free and just report them +with uh with the output okay and you + + align:start position:0% +with uh with the output okay and you + + + align:start position:0% +with uh with the output okay and you +know that's fine and we can use those + + align:start position:0% +know that's fine and we can use those + + + align:start position:0% +know that's fine and we can use those +and they're often quite handy um but + + align:start position:0% +and they're often quite handy um but + + + align:start position:0% +and they're often quite handy um but +there may be other ones that we need to + + align:start position:0% +there may be other ones that we need to + + + align:start position:0% +there may be other ones that we need to +do ourselves so they don't perform every + + align:start position:0% +do ourselves so they don't perform every + + + align:start position:0% +do ourselves so they don't perform every +conceivable test we might be interested + + align:start position:0% +conceivable test we might be interested + + + align:start position:0% +conceivable test we might be interested +in okay so let's start with a pretty + + align:start position:0% +in okay so let's start with a pretty + + + align:start position:0% +in okay so let's start with a pretty +General framework for testing hypotheses + + align:start position:0% +General framework for testing hypotheses + + + align:start position:0% +General framework for testing hypotheses +about beta and it's not only quite + + align:start position:0% +about beta and it's not only quite + + + align:start position:0% +about beta and it's not only quite +General and flexible it's also super + + align:start position:0% +General and flexible it's also super + + + align:start position:0% +General and flexible it's also super +intuitive it's like one of my favorite + + align:start position:0% +intuitive it's like one of my favorite + + + align:start position:0% +intuitive it's like one of my favorite +tests I really like it okay so let's + + align:start position:0% +tests I really like it okay so let's + + + align:start position:0% +tests I really like it okay so let's +consider hypothesis the following + + align:start position:0% +consider hypothesis the following + + + align:start position:0% +consider hypothesis the following +form a matrix R Time beta is equal to a + + align:start position:0% +form a matrix R Time beta is equal to a + + + align:start position:0% +form a matrix R Time beta is equal to a +vector C that's the null hypothesis the + + align:start position:0% +vector C that's the null hypothesis the + + + align:start position:0% +vector C that's the null hypothesis the +alternative is that it's not equal to + + align:start position:0% +alternative is that it's not equal to + + + align:start position:0% +alternative is that it's not equal to +the vector C so what is this Matrix R + + align:start position:0% +the vector C so what is this Matrix R + + + align:start position:0% +the vector C so what is this Matrix R +it's a matrix of + + align:start position:0% +it's a matrix of + + + align:start position:0% +it's a matrix of +restrictions okay and its uh dimensions + + align:start position:0% +restrictions okay and its uh dimensions + + + align:start position:0% +restrictions okay and its uh dimensions +are R by k + 1 so it has the number of + + align:start position:0% +are R by k + 1 so it has the number of + + + align:start position:0% +are R by k + 1 so it has the number of +so it's the the number of columns is + + align:start position:0% +so it's the the number of columns is + + + align:start position:0% +so it's the the number of columns is +equal to the number of parameters the + + align:start position:0% +equal to the number of parameters the + + + align:start position:0% +equal to the number of parameters the +number of betas that we're estimating in + + align:start position:0% +number of betas that we're estimating in + + + align:start position:0% +number of betas that we're estimating in +the linear model and then the number of + + align:start position:0% +the linear model and then the number of + + + align:start position:0% +the linear model and then the number of +rows is the number of restrictions that + + align:start position:0% +rows is the number of restrictions that + + + align:start position:0% +rows is the number of restrictions that +we want to impose in our null hypothesis + + align:start position:0% +we want to impose in our null hypothesis + + + align:start position:0% +we want to impose in our null hypothesis +the number of restrictions we want to + + align:start position:0% +the number of restrictions we want to + + + align:start position:0% +the number of restrictions we want to +test so if R so we could have a matrix + + align:start position:0% +test so if R so we could have a matrix + + + align:start position:0% +test so if R so we could have a matrix +um that's just where R is equal to one + + align:start position:0% +um that's just where R is equal to one + + + align:start position:0% +um that's just where R is equal to one +and then we're just testing one + + align:start position:0% +and then we're just testing one + + + align:start position:0% +and then we're just testing one +restriction so that would correspond to + + align:start position:0% +restriction so that would correspond to + + + align:start position:0% +restriction so that would correspond to +something like beta 1 is equal to zero + + align:start position:0% +something like beta 1 is equal to zero + + + align:start position:0% +something like beta 1 is equal to zero +okay so let + + align:start position:0% +okay so let + + + align:start position:0% +okay so let +me oh so let me just say this I'll get + + align:start position:0% +me oh so let me just say this I'll get + + + align:start position:0% +me oh so let me just say this I'll get +to some examples in a minute okay so + + align:start position:0% +to some examples in a minute okay so + + + align:start position:0% +to some examples in a minute okay so +almost any hypothesis involving beta you + + align:start position:0% +almost any hypothesis involving beta you + + + align:start position:0% +almost any hypothesis involving beta you +can dream up in the context of the + + align:start position:0% +can dream up in the context of the + + + align:start position:0% +can dream up in the context of the +linear model can be captured in this + + align:start position:0% +linear model can be captured in this + + + align:start position:0% +linear model can be captured in this +framework not quite any but most of them + + align:start position:0% +framework not quite any but most of them + + + align:start position:0% +framework not quite any but most of them +you can test whether individual + + align:start position:0% +you can test whether individual + + + align:start position:0% +you can test whether individual +parameters are equal to zero you can + + align:start position:0% +parameters are equal to zero you can + + + align:start position:0% +parameters are equal to zero you can +test whether individual parameters are + + align:start position:0% +test whether individual parameters are + + + align:start position:0% +test whether individual parameters are +equal to something other than zero you + + align:start position:0% +equal to something other than zero you + + + align:start position:0% +equal to something other than zero you +can test multiple hypotheses + + align:start position:0% +can test multiple hypotheses + + + align:start position:0% +can test multiple hypotheses +simultaneously you can test hypothesis + + align:start position:0% +simultaneously you can test hypothesis + + + align:start position:0% +simultaneously you can test hypothesis +about linear combinations of parameters + + align:start position:0% +about linear combinations of parameters + + + align:start position:0% +about linear combinations of parameters +the world is your oyster okay so let me + + align:start position:0% +the world is your oyster okay so let me + + + align:start position:0% +the world is your oyster okay so let me +show you a few examples of these and + + align:start position:0% +show you a few examples of these and + + + align:start position:0% +show you a few examples of these and +exactly what the r Matrix looks like and + + align:start position:0% +exactly what the r Matrix looks like and + + + align:start position:0% +exactly what the r Matrix looks like and +what the C Vector looks like in these + + align:start position:0% +what the C Vector looks like in these + + + align:start position:0% +what the C Vector looks like in these +examples okay so let's say for instance + + align:start position:0% +examples okay so let's say for instance + + + align:start position:0% +examples okay so let's say for instance +that we set up the Matrix R to be just a + + align:start position:0% +that we set up the Matrix R to be just a + + + align:start position:0% +that we set up the Matrix R to be just a +row Vector with a zero in the first spot + + align:start position:0% +row Vector with a zero in the first spot + + + align:start position:0% +row Vector with a zero in the first spot +and then a one and then the rest zeros + + align:start position:0% +and then a one and then the rest zeros + + + align:start position:0% +and then a one and then the rest zeros +so what that Matrix is doing is it's + + align:start position:0% +so what that Matrix is doing is it's + + + align:start position:0% +so what that Matrix is doing is it's +picking out beta 1 okay remember it this + + align:start position:0% +picking out beta 1 okay remember it this + + + align:start position:0% +picking out beta 1 okay remember it this +this spot corresponds to Beta not okay + + align:start position:0% +this spot corresponds to Beta not okay + + + align:start position:0% +this spot corresponds to Beta not okay +so it's picking so being in the second + + align:start position:0% +so it's picking so being in the second + + + align:start position:0% +so it's picking so being in the second +spot it's picking out beta 1 and C is + + align:start position:0% +spot it's picking out beta 1 and C is + + + align:start position:0% +spot it's picking out beta 1 and C is +just what uh beta 1 is equal to under + + align:start position:0% +just what uh beta 1 is equal to under + + + align:start position:0% +just what uh beta 1 is equal to under +the null okay so that R and this C + + align:start position:0% +the null okay so that R and this C + + + align:start position:0% +the null okay so that R and this C +corresponds to the hypothesis that beta + + align:start position:0% +corresponds to the hypothesis that beta + + + align:start position:0% +corresponds to the hypothesis that beta +1 is equal to + + align:start position:0% +1 is equal to + + + align:start position:0% +1 is equal to +zero okay + + align:start position:0% + + + + align:start position:0% + +let's suppose instead that we want to + + align:start position:0% +let's suppose instead that we want to + + + align:start position:0% +let's suppose instead that we want to +test a whole bunch of hypotheses + + align:start position:0% +test a whole bunch of hypotheses + + + align:start position:0% +test a whole bunch of hypotheses +simultaneously that beta 1 is equal to + + align:start position:0% +simultaneously that beta 1 is equal to + + + align:start position:0% +simultaneously that beta 1 is equal to +zero and beta 2 is equal to zero and + + align:start position:0% +zero and beta 2 is equal to zero and + + + align:start position:0% +zero and beta 2 is equal to zero and +beta 3 is equal to zero Etc well then + + align:start position:0% +beta 3 is equal to zero Etc well then + + + align:start position:0% +beta 3 is equal to zero Etc well then +this is what our R Matrix would look + + align:start position:0% +this is what our R Matrix would look + + + align:start position:0% +this is what our R Matrix would look +like okay so it would basically be an + + align:start position:0% +like okay so it would basically be an + + + align:start position:0% +like okay so it would basically be an +identity Matrix with a column of zeros + + align:start position:0% +identity Matrix with a column of zeros + + + align:start position:0% +identity Matrix with a column of zeros +tacked on the front the reason why the + + align:start position:0% +tacked on the front the reason why the + + + align:start position:0% +tacked on the front the reason why the +column of zeros is tacked on the front + + align:start position:0% +column of zeros is tacked on the front + + + align:start position:0% +column of zeros is tacked on the front +is because that corresponds to the + + align:start position:0% +is because that corresponds to the + + + align:start position:0% +is because that corresponds to the +intercept and we we're not interested at + + align:start position:0% +intercept and we we're not interested at + + + align:start position:0% +intercept and we we're not interested at +least here in testing a hypothesis about + + align:start position:0% +least here in testing a hypothesis about + + + align:start position:0% +least here in testing a hypothesis about +The Intercept + + align:start position:0% +The Intercept + + + align:start position:0% +The Intercept +okay and then the C Vector uh is just a + + align:start position:0% +okay and then the C Vector uh is just a + + + align:start position:0% +okay and then the C Vector uh is just a +vector of + + align:start position:0% +vector of + + + align:start position:0% +vector of +zeros + + align:start position:0% + + + + align:start position:0% + +okay so I do want to emphasize even + + align:start position:0% +okay so I do want to emphasize even + + + align:start position:0% +okay so I do want to emphasize even +though I've sort of written this as like + + align:start position:0% +though I've sort of written this as like + + + align:start position:0% +though I've sort of written this as like +one equation this is actually we're + + align:start position:0% +one equation this is actually we're + + + align:start position:0% +one equation this is actually we're +testing K hypotheses simultaneously here + + align:start position:0% +testing K hypotheses simultaneously here + + + align:start position:0% +testing K hypotheses simultaneously here +so we have K uh equal signs + + align:start position:0% + + + + align:start position:0% + +okay so here's a more complicated + + align:start position:0% +okay so here's a more complicated + + + align:start position:0% +okay so here's a more complicated +example if our R Matrix has in the first + + align:start position:0% +example if our R Matrix has in the first + + + align:start position:0% +example if our R Matrix has in the first +row a one and a negative one and then + + align:start position:0% +row a one and a negative one and then + + + align:start position:0% +row a one and a negative one and then +the rest zeros sorry zero and then one + + align:start position:0% +the rest zeros sorry zero and then one + + + align:start position:0% +the rest zeros sorry zero and then one +negative one the rest zeros um and then + + align:start position:0% +negative one the rest zeros um and then + + + align:start position:0% +negative one the rest zeros um and then +the second row there's a one in the + + align:start position:0% +the second row there's a one in the + + + align:start position:0% +the second row there's a one in the +fourth + + align:start position:0% +fourth + + + align:start position:0% +fourth +spot + + align:start position:0% +spot + + + align:start position:0% +spot +Etc then and then the C Vector looks + + align:start position:0% +Etc then and then the C Vector looks + + + align:start position:0% +Etc then and then the C Vector looks +like this + + align:start position:0% +like this + + + align:start position:0% +like this +what does this correspond to in terms of + + align:start position:0% +what does this correspond to in terms of + + + align:start position:0% +what does this correspond to in terms of +a a hypothesis we might want to test or + + align:start position:0% +a a hypothesis we might want to test or + + + align:start position:0% +a a hypothesis we might want to test or +a series of + + align:start position:0% +a series of + + + align:start position:0% +a series of +hypotheses well here the first row gives + + align:start position:0% +hypotheses well here the first row gives + + + align:start position:0% +hypotheses well here the first row gives +us the hypothesis that beta 1 minus beta + + align:start position:0% +us the hypothesis that beta 1 minus beta + + + align:start position:0% +us the hypothesis that beta 1 minus beta +2 is equal to zero so I could just write + + align:start position:0% +2 is equal to zero so I could just write + + + align:start position:0% +2 is equal to zero so I could just write +that as beta 1 is equal to Beta 2 right + + align:start position:0% +that as beta 1 is equal to Beta 2 right + + + align:start position:0% +that as beta 1 is equal to Beta 2 right +the second row corresponds to Beta 3 + + align:start position:0% +the second row corresponds to Beta 3 + + + align:start position:0% +the second row corresponds to Beta 3 +this is beta 3 here being equal to five + + align:start position:0% +this is beta 3 here being equal to five + + + align:start position:0% +this is beta 3 here being equal to five +okay and and the third row corresponds + + align:start position:0% +okay and and the third row corresponds + + + align:start position:0% +okay and and the third row corresponds +to Beta K being equal to + + align:start position:0% +to Beta K being equal to + + + align:start position:0% +to Beta K being equal to +-2 + + align:start position:0% +-2 + + + align:start position:0% +-2 +yes beta + + align:start position:0% +yes beta + + + align:start position:0% +yes beta +1sa okay so if I just wrote If I just uh + + align:start position:0% +1sa okay so if I just wrote If I just uh + + + align:start position:0% +1sa okay so if I just wrote If I just uh +wrote out what the you know just + + align:start position:0% +wrote out what the you know just + + + align:start position:0% +wrote out what the you know just +multiplied The Matrix um the r matrix by + + align:start position:0% +multiplied The Matrix um the r matrix by + + + align:start position:0% +multiplied The Matrix um the r matrix by +Beta And you know sort of wrote These + + align:start position:0% +Beta And you know sort of wrote These + + + align:start position:0% +Beta And you know sort of wrote These +out as equations I would get beta 1 + + align:start position:0% +out as equations I would get beta 1 + + + align:start position:0% +out as equations I would get beta 1 +minus so this is beta 0 here so here's + + align:start position:0% +minus so this is beta 0 here so here's + + + align:start position:0% +minus so this is beta 0 here so here's +beta 1 minus beta 2 is equal to + + align:start position:0% +beta 1 minus beta 2 is equal to + + + align:start position:0% +beta 1 minus beta 2 is equal to +Z okay and then I just rewrote that is + + align:start position:0% +Z okay and then I just rewrote that is + + + align:start position:0% +Z okay and then I just rewrote that is +beta 1 is equal to Beta 2 that's all yep + + align:start position:0% +beta 1 is equal to Beta 2 that's all yep + + + align:start position:0% +beta 1 is equal to Beta 2 that's all yep +how often are we interested + + align:start position:0% +how often are we interested + + + align:start position:0% +how often are we interested +seea specific value rather than range + + align:start position:0% +seea specific value rather than range + + + align:start position:0% +seea specific value rather than range +and is there a way to that + + align:start position:0% +and is there a way to that + + + align:start position:0% +and is there a way to that +so yes and no so basically what if we're + + align:start position:0% +so yes and no so basically what if we're + + + align:start position:0% +so yes and no so basically what if we're +not interested in um if we're interested + + align:start position:0% +not interested in um if we're interested + + + align:start position:0% +not interested in um if we're interested +in whether beta is in a Range then what + + align:start position:0% +in whether beta is in a Range then what + + + align:start position:0% +in whether beta is in a Range then what +we might want to do is instead of doing + + align:start position:0% +we might want to do is instead of doing + + + align:start position:0% +we might want to do is instead of doing +a hypothesis test where the null was a + + align:start position:0% +a hypothesis test where the null was a + + + align:start position:0% +a hypothesis test where the null was a +single value and the alternative was + + align:start position:0% +single value and the alternative was + + + align:start position:0% +single value and the alternative was +everything else we might want to do say + + align:start position:0% +everything else we might want to do say + + + align:start position:0% +everything else we might want to do say +a one-sided test where the null is that + + align:start position:0% +a one-sided test where the null is that + + + align:start position:0% +a one-sided test where the null is that +beta is less than some value and the + + align:start position:0% +beta is less than some value and the + + + align:start position:0% +beta is less than some value and the +alternative is that it's greater than + + align:start position:0% +alternative is that it's greater than + + + align:start position:0% +alternative is that it's greater than +some value we can do those we can't do + + align:start position:0% +some value we can do those we can't do + + + align:start position:0% +some value we can do those we can't do +them in this framework so I'll talk + + align:start position:0% +them in this framework so I'll talk + + + align:start position:0% +them in this framework so I'll talk +about that in a second the other the + + align:start position:0% +about that in a second the other the + + + align:start position:0% +about that in a second the other the +other thing that you might be suggesting + + align:start position:0% +other thing that you might be suggesting + + + align:start position:0% +other thing that you might be suggesting +is instead of doing hypothesis testing + + align:start position:0% +is instead of doing hypothesis testing + + + align:start position:0% +is instead of doing hypothesis testing +we might want to just report confidence + + align:start position:0% +we might want to just report confidence + + + align:start position:0% +we might want to just report confidence +intervals as well so remember that that + + align:start position:0% +intervals as well so remember that that + + + align:start position:0% +intervals as well so remember that that +really hypothesis testing and + + align:start position:0% +really hypothesis testing and + + + align:start position:0% +really hypothesis testing and +constructing confidence intervals are + + align:start position:0% +constructing confidence intervals are + + + align:start position:0% +constructing confidence intervals are +kind of the same thing just reporting + + align:start position:0% +kind of the same thing just reporting + + + align:start position:0% +kind of the same thing just reporting +the same information in different forms + + align:start position:0% +the same information in different forms + + + align:start position:0% +the same information in different forms +and so um you know it can just be a + + align:start position:0% +and so um you know it can just be a + + + align:start position:0% +and so um you know it can just be a +matter of style or preference uh instead + + align:start position:0% +matter of style or preference uh instead + + + align:start position:0% +matter of style or preference uh instead +of uh reporting hypothesis tests you + + align:start position:0% +of uh reporting hypothesis tests you + + + align:start position:0% +of uh reporting hypothesis tests you +report confidence intervals and that's + + align:start position:0% +report confidence intervals and that's + + + align:start position:0% +report confidence intervals and that's +perfectly fine yeah confidence inter + + align:start position:0% +perfectly fine yeah confidence inter + + + align:start position:0% +perfectly fine yeah confidence inter +will be hard to say + + align:start position:0% + + + + align:start position:0% + +-4 is yeah in I mean it's kind of hard + + align:start position:0% +-4 is yeah in I mean it's kind of hard + + + align:start position:0% +-4 is yeah in I mean it's kind of hard +to see they don't really add up so yeah + + align:start position:0% +to see they don't really add up so yeah + + + align:start position:0% +to see they don't really add up so yeah +and I guess I guess the other the other + + align:start position:0% +and I guess I guess the other the other + + + align:start position:0% +and I guess I guess the other the other +sort of more fundamental answer to your + + align:start position:0% +sort of more fundamental answer to your + + + align:start position:0% +sort of more fundamental answer to your +question is that sometimes we actually + + align:start position:0% +question is that sometimes we actually + + + align:start position:0% +question is that sometimes we actually +do like there might be a theory that + + align:start position:0% +do like there might be a theory that + + + align:start position:0% +do like there might be a theory that +says beta should be equal to this number + + align:start position:0% +says beta should be equal to this number + + + align:start position:0% +says beta should be equal to this number +and we're in order to test that theory + + align:start position:0% +and we're in order to test that theory + + + align:start position:0% +and we're in order to test that theory +we want to perform a hypothesis test + + align:start position:0% +we want to perform a hypothesis test + + + align:start position:0% +we want to perform a hypothesis test +that beta is equal to that number so + + align:start position:0% +that beta is equal to that number so + + + align:start position:0% +that beta is equal to that number so +that does come up um and not every but + + align:start position:0% +that does come up um and not every but + + + align:start position:0% +that does come up um and not every but +yeah it is it is relevant other + + align:start position:0% +yeah it is it is relevant other + + + align:start position:0% +yeah it is it is relevant other +questions no you could also use it + + align:start position:0% +questions no you could also use it + + + align:start position:0% +questions no you could also use it +to if somebody came out with a paper say + + align:start position:0% +to if somebody came out with a paper say + + + align:start position:0% +to if somebody came out with a paper say +describing the treatment of valarian X + + align:start position:0% +describing the treatment of valarian X + + + align:start position:0% +describing the treatment of valarian X +and you wanted to see if that was true + + align:start position:0% +and you wanted to see if that was true + + + align:start position:0% +and you wanted to see if that was true +or not and you just take that beta test + + align:start position:0% +or not and you just take that beta test + + + align:start position:0% +or not and you just take that beta test +for do hypothesis Tes right yeah + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay okay oh here's here's part of the + + align:start position:0% +okay okay oh here's here's part of the + + + align:start position:0% +okay okay oh here's here's part of the +answer to your question one thing you + + align:start position:0% +answer to your question one thing you + + + align:start position:0% +answer to your question one thing you +can't do in this framework as test + + align:start position:0% +can't do in this framework as test + + + align:start position:0% +can't do in this framework as test +one-sided hypothesis we'll get back to + + align:start position:0% +one-sided hypothesis we'll get back to + + + align:start position:0% +one-sided hypothesis we'll get back to +those okay so so now we have um we have + + align:start position:0% +those okay so so now we have um we have + + + align:start position:0% +those okay so so now we have um we have +this + + align:start position:0% +this + + + align:start position:0% +this +framework I mean it's not really + + align:start position:0% +framework I mean it's not really + + + align:start position:0% +framework I mean it's not really +framework just sort of a notation in + + align:start position:0% +framework just sort of a notation in + + + align:start position:0% +framework just sort of a notation in +some sense to set up you know the to + + align:start position:0% +some sense to set up you know the to + + + align:start position:0% +some sense to set up you know the to +deal with sort of um hypotheses of of + + align:start position:0% +deal with sort of um hypotheses of of + + + align:start position:0% +deal with sort of um hypotheses of of +all of the forms we just talked about + + align:start position:0% +all of the forms we just talked about + + + align:start position:0% +all of the forms we just talked about +and within the regression framework we + + align:start position:0% +and within the regression framework we + + + align:start position:0% +and within the regression framework we +have a super intuitive and cool way to + + align:start position:0% +have a super intuitive and cool way to + + + align:start position:0% +have a super intuitive and cool way to +test these hypotheses so first of all + + align:start position:0% +test these hypotheses so first of all + + + align:start position:0% +test these hypotheses so first of all +let's think of the null is describing a + + align:start position:0% +let's think of the null is describing a + + + align:start position:0% +let's think of the null is describing a +set of restrictions on the model okay so + + align:start position:0% +set of restrictions on the model okay so + + + align:start position:0% +set of restrictions on the model okay so +let me just go back for a second so in + + align:start position:0% +let me just go back for a second so in + + + align:start position:0% +let me just go back for a second so in +this case this null has three different + + align:start position:0% +this case this null has three different + + + align:start position:0% +this case this null has three different +restrictions that beta 1 is equal to + + align:start position:0% +restrictions that beta 1 is equal to + + + align:start position:0% +restrictions that beta 1 is equal to +Beta 2 that beta 3 is equal to 5 and + + align:start position:0% +Beta 2 that beta 3 is equal to 5 and + + + align:start position:0% +Beta 2 that beta 3 is equal to 5 and +that beta K is equal to minus two okay + + align:start position:0% +that beta K is equal to minus two okay + + + align:start position:0% +that beta K is equal to minus two okay +so we think of the null as imposing + + align:start position:0% +so we think of the null as imposing + + + align:start position:0% +so we think of the null as imposing +restrictions on the + + align:start position:0% +restrictions on the + + + align:start position:0% +restrictions on the +model then here's how we perform the + + align:start position:0% +model then here's how we perform the + + + align:start position:0% +model then here's how we perform the +test we estimate the unrestricted model + + align:start position:0% +test we estimate the unrestricted model + + + align:start position:0% +test we estimate the unrestricted model +we impose the restrictions of the null + + align:start position:0% +we impose the restrictions of the null + + + align:start position:0% +we impose the restrictions of the null +and estimate that model and then we + + align:start position:0% +and estimate that model and then we + + + align:start position:0% +and estimate that model and then we +compare the goodness of fit of those two + + align:start position:0% +compare the goodness of fit of those two + + + align:start position:0% +compare the goodness of fit of those two +models okay so that's why I love this + + align:start position:0% +models okay so that's why I love this + + + align:start position:0% +models okay so that's why I love this +test it's just it seems really intuitive + + align:start position:0% +test it's just it seems really intuitive + + + align:start position:0% +test it's just it seems really intuitive +to me that if you have a set of + + align:start position:0% +to me that if you have a set of + + + align:start position:0% +to me that if you have a set of +restrictions and they really + + align:start position:0% +restrictions and they really + + + align:start position:0% +restrictions and they really +bind and like the the they really sort + + align:start position:0% +bind and like the the they really sort + + + align:start position:0% +bind and like the the they really sort +of affect how good your fit is then that + + align:start position:0% +of affect how good your fit is then that + + + align:start position:0% +of affect how good your fit is then that +tells you well maybe those restrictions + + align:start position:0% +tells you well maybe those restrictions + + + align:start position:0% +tells you well maybe those restrictions +are not + + align:start position:0% +are not + + + align:start position:0% +are not +true if the restrictions on the other + + align:start position:0% +true if the restrictions on the other + + + align:start position:0% +true if the restrictions on the other +hand don't really bind that much if your + + align:start position:0% +hand don't really bind that much if your + + + align:start position:0% +hand don't really bind that much if your +your um model fil fits almost as well + + align:start position:0% +your um model fil fits almost as well + + + align:start position:0% +your um model fil fits almost as well +with the unrestricted model the + + align:start position:0% +with the unrestricted model the + + + align:start position:0% +with the unrestricted model the +restricted model as it does with the + + align:start position:0% +restricted model as it does with the + + + align:start position:0% +restricted model as it does with the +unrestricted model then that tells you + + align:start position:0% +unrestricted model then that tells you + + + align:start position:0% +unrestricted model then that tells you +maybe these restrictions are true or + + align:start position:0% +maybe these restrictions are true or + + + align:start position:0% +maybe these restrictions are true or +close to true and we don't want to + + align:start position:0% +close to true and we don't want to + + + align:start position:0% +close to true and we don't want to +reject them okay so that's the whole + + align:start position:0% +reject them okay so that's the whole + + + align:start position:0% +reject them okay so that's the whole +intuition and the idea behind this + + align:start position:0% + + + + align:start position:0% + +test okay + + align:start position:0% +test okay + + + align:start position:0% +test okay +so um estimating so a couple details + + align:start position:0% +so um estimating so a couple details + + + align:start position:0% +so um estimating so a couple details +before we get to sort of the + + align:start position:0% +before we get to sort of the + + + align:start position:0% +before we get to sort of the +distribution the test statistic + + align:start position:0% +distribution the test statistic + + + align:start position:0% +distribution the test statistic +estimating the unrestricted model is + + align:start position:0% +estimating the unrestricted model is + + + align:start position:0% +estimating the unrestricted model is +simple just run the regression but how + + align:start position:0% +simple just run the regression but how + + + align:start position:0% +simple just run the regression but how +do we estimate the restricted model well + + align:start position:0% +do we estimate the restricted model well + + + align:start position:0% +do we estimate the restricted model well +let's it depends on how what form the + + align:start position:0% +let's it depends on how what form the + + + align:start position:0% +let's it depends on how what form the +restrictions take so let's say we have + + align:start position:0% +restrictions take so let's say we have + + + align:start position:0% +restrictions take so let's say we have +we're testing hypothesis where uh just a + + align:start position:0% +we're testing hypothesis where uh just a + + + align:start position:0% +we're testing hypothesis where uh just a +bunch of the betas are equal to zero how + + align:start position:0% +bunch of the betas are equal to zero how + + + align:start position:0% +bunch of the betas are equal to zero how +do we run the restricted + + align:start position:0% + + + + align:start position:0% + +model yes we just think the on the one + + align:start position:0% +model yes we just think the on the one + + + align:start position:0% +model yes we just think the on the one +Z yes exactly so we just leave out so so + + align:start position:0% +Z yes exactly so we just leave out so so + + + align:start position:0% +Z yes exactly so we just leave out so so +practically speaking what we do is we + + align:start position:0% +practically speaking what we do is we + + + align:start position:0% +practically speaking what we do is we +just run the regression leaving out all + + align:start position:0% +just run the regression leaving out all + + + align:start position:0% +just run the regression leaving out all +of those X's so that's the way we + + align:start position:0% +of those X's so that's the way we + + + align:start position:0% +of those X's so that's the way we +constrain the the coefficients to be + + align:start position:0% +constrain the the coefficients to be + + + align:start position:0% +constrain the the coefficients to be +equal to zero okay so we have the + + align:start position:0% +equal to zero okay so we have the + + + align:start position:0% +equal to zero okay so we have the +unrestricted the unrestricted regression + + align:start position:0% +unrestricted the unrestricted regression + + + align:start position:0% +unrestricted the unrestricted regression +is just sort of all of the X's are in + + align:start position:0% +is just sort of all of the X's are in + + + align:start position:0% +is just sort of all of the X's are in +there if we want to restrict that + + align:start position:0% +there if we want to restrict that + + + align:start position:0% +there if we want to restrict that +certain betas are equal to zero we just + + align:start position:0% +certain betas are equal to zero we just + + + align:start position:0% +certain betas are equal to zero we just +run another regression where we leave + + align:start position:0% +run another regression where we leave + + + align:start position:0% +run another regression where we leave +out the X's associated with the betas + + align:start position:0% +out the X's associated with the betas + + + align:start position:0% +out the X's associated with the betas +that that we want to have equal to zero + + align:start position:0% +that that we want to have equal to zero + + + align:start position:0% +that that we want to have equal to zero +okay so that's our our restricted + + align:start position:0% +okay so that's our our restricted + + + align:start position:0% +okay so that's our our restricted +model okay then let's say the + + align:start position:0% +model okay then let's say the + + + align:start position:0% +model okay then let's say the +Restriction is that the two betas are + + align:start position:0% +Restriction is that the two betas are + + + align:start position:0% +Restriction is that the two betas are +equal we have you know beta 1 equals + + align:start position:0% +equal we have you know beta 1 equals + + + align:start position:0% +equal we have you know beta 1 equals +beta 2 or something like that that's our + + align:start position:0% +beta 2 or something like that that's our + + + align:start position:0% +beta 2 or something like that that's our +null restriction um then how do we + + align:start position:0% +null restriction um then how do we + + + align:start position:0% +null restriction um then how do we +impose that restriction on a linear + + align:start position:0% +impose that restriction on a linear + + + align:start position:0% +impose that restriction on a linear +model well let me actually might help if + + align:start position:0% +model well let me actually might help if + + + align:start position:0% +model well let me actually might help if +I write the linear model so we have y + + align:start position:0% +I write the linear model so we have y + + + align:start position:0% +I write the linear model so we have y +subi + + align:start position:0% +subi + + + align:start position:0% +subi +equal beta KN plus beta + + align:start position:0% +equal beta KN plus beta + + + align:start position:0% +equal beta KN plus beta + + align:start position:0% + + + align:start position:0% +X1 ah I hope I'm using the same + + align:start position:0% + + + + align:start position:0% + +notation do I have my subscripts in the + + align:start position:0% +notation do I have my subscripts in the + + + align:start position:0% +notation do I have my subscripts in the +same order I hope + + align:start position:0% + + + + align:start position:0% + +so okay so let's suppose this is our um + + align:start position:0% +so okay so let's suppose this is our um + + + align:start position:0% +so okay so let's suppose this is our um +this is our our uh unrestricted model we + + align:start position:0% +this is our our uh unrestricted model we + + + align:start position:0% +this is our our uh unrestricted model we +want to restrict beta one to be equal to + + align:start position:0% +want to restrict beta one to be equal to + + + align:start position:0% +want to restrict beta one to be equal to +Beta 2 well what do we do we just create + + align:start position:0% +Beta 2 well what do we do we just create + + + align:start position:0% +Beta 2 well what do we do we just create +a new variable that's the sum of these + + align:start position:0% +a new variable that's the sum of these + + + align:start position:0% +a new variable that's the sum of these +two so this is + + align:start position:0% +two so this is + + + align:start position:0% +two so this is +called X1 i+ x 2 I it's just a new + + align:start position:0% +called X1 i+ x 2 I it's just a new + + + align:start position:0% +called X1 i+ x 2 I it's just a new +variable and then we only + + align:start position:0% +variable and then we only + + + align:start position:0% +variable and then we only +estimate + + align:start position:0% +estimate + + + align:start position:0% +estimate +one coefficient on that so our + + align:start position:0% +one coefficient on that so our + + + align:start position:0% +one coefficient on that so our +restricted model is just that we create + + align:start position:0% +restricted model is just that we create + + + align:start position:0% +restricted model is just that we create +we don't don't include this variable as + + align:start position:0% +we don't don't include this variable as + + + align:start position:0% +we don't don't include this variable as +a regressor or this variable as a + + align:start position:0% +a regressor or this variable as a + + + align:start position:0% +a regressor or this variable as a +regressor we include their sum as a + + align:start position:0% +regressor we include their sum as a + + + align:start position:0% +regressor we include their sum as a +regressor okay and that's how we're + + align:start position:0% +regressor okay and that's how we're + + + align:start position:0% +regressor okay and that's how we're +imposing the null restriction because + + align:start position:0% +imposing the null restriction because + + + align:start position:0% +imposing the null restriction because +when we include their sum we're making + + align:start position:0% +when we include their sum we're making + + + align:start position:0% +when we include their sum we're making +their two coefficients equal we're + + align:start position:0% +their two coefficients equal we're + + + align:start position:0% +their two coefficients equal we're +forcing their two coefficients to be + + align:start position:0% +forcing their two coefficients to be + + + align:start position:0% +forcing their two coefficients to be +equal okay yep so are we testing the + + align:start position:0% +equal okay yep so are we testing the + + + align:start position:0% +equal okay yep so are we testing the +first beta one and the second beta one + + align:start position:0% +first beta one and the second beta one + + + align:start position:0% +first beta one and the second beta one +are the same exactly yes this is this is + + align:start position:0% +are the same exactly yes this is this is + + + align:start position:0% +are the same exactly yes this is this is +testing the hypothesis + + align:start position:0% +testing the hypothesis + + + align:start position:0% +testing the hypothesis +that beta 1 is equal to Beta 2 okay yep + + align:start position:0% +that beta 1 is equal to Beta 2 okay yep + + + align:start position:0% +that beta 1 is equal to Beta 2 okay yep +is that beta + + align:start position:0% +is that beta + + + align:start position:0% +is that beta +2 yeah it's definitely different yeah so + + align:start position:0% +2 yeah it's definitely different yeah so + + + align:start position:0% +2 yeah it's definitely different yeah so +here these these betas could be ver + + align:start position:0% +here these these betas could be ver + + + align:start position:0% +here these these betas could be ver +could be anything they could be a + + align:start position:0% +could be anything they could be a + + + align:start position:0% +could be anything they could be a +million we're just the hypo we're just + + align:start position:0% +million we're just the hypo we're just + + + align:start position:0% +million we're just the hypo we're just +testing the hypothesis that they're + + align:start position:0% +testing the hypothesis that they're + + + align:start position:0% +testing the hypothesis that they're +equal + + align:start position:0% +equal + + + align:start position:0% +equal +okay so yes uh but if if it's + + align:start position:0% +okay so yes uh but if if it's + + + align:start position:0% +okay so yes uh but if if it's +a but if they're equal wouldn't it be + + align:start position:0% +a but if they're equal wouldn't it be + + + align:start position:0% +a but if they're equal wouldn't it be +like a linear combination of together + + align:start position:0% +like a linear combination of together + + + align:start position:0% +like a linear combination of together +and become Zer you know how like we have + + align:start position:0% +and become Zer you know how like we have + + + align:start position:0% +and become Zer you know how like we have +to they cannot be like a line + + align:start position:0% +to they cannot be like a line + + + align:start position:0% +to they cannot be like a line +some I'm not uh not sure if I understand + + align:start position:0% +some I'm not uh not sure if I understand + + + align:start position:0% +some I'm not uh not sure if I understand +your question so basically what what I'm + + align:start position:0% +your question so basically what what I'm + + + align:start position:0% +your question so basically what what I'm +trying to do here is impose just this + + align:start position:0% +trying to do here is impose just this + + + align:start position:0% +trying to do here is impose just this +hypothesis but not impose anything else + + align:start position:0% +hypothesis but not impose anything else + + + align:start position:0% +hypothesis but not impose anything else +about what the betas might be uh equal + + align:start position:0% +about what the betas might be uh equal + + + align:start position:0% +about what the betas might be uh equal +to the + + align:start position:0% +to the + + + align:start position:0% +to the +identification restriction is not on the + + align:start position:0% +identification restriction is not on the + + + align:start position:0% +identification restriction is not on the +betas it's on the ex + + align:start position:0% +betas it's on the ex + + + align:start position:0% +betas it's on the ex +can + + align:start position:0% +can + + + align:start position:0% +can +whatever ahh you were confused about the + + align:start position:0% +whatever ahh you were confused about the + + + align:start position:0% +whatever ahh you were confused about the +identification assumption y yep y that's + + align:start position:0% +identification assumption y yep y that's + + + align:start position:0% +identification assumption y yep y that's +right okay um what if the if you we can + + align:start position:0% +right okay um what if the if you we can + + + align:start position:0% +right okay um what if the if you we can +re ask your question saying if you could + + align:start position:0% +re ask your question saying if you could + + + align:start position:0% +re ask your question saying if you could +OST the sum and just X and that in fact + + align:start position:0% +OST the sum and just X and that in fact + + + align:start position:0% +OST the sum and just X and that in fact +they were + + align:start position:0% +they were + + + align:start position:0% +they were +equal you can guess what the beta be + + align:start position:0% + + + + align:start position:0% + +X okay what if the Restriction is that + + align:start position:0% +X okay what if the Restriction is that + + + align:start position:0% +X okay what if the Restriction is that +sum beta is equal to to a constant + + align:start position:0% +sum beta is equal to to a constant + + + align:start position:0% +sum beta is equal to to a constant +C how would we impose that restriction + + align:start position:0% +C how would we impose that restriction + + + align:start position:0% +C how would we impose that restriction +and then reestimate the restricted model + + align:start position:0% +and then reestimate the restricted model + + + align:start position:0% +and then reestimate the restricted model +well if we have let's suppose this is + + align:start position:0% +well if we have let's suppose this is + + + align:start position:0% +well if we have let's suppose this is +just a constant so we impose that this + + align:start position:0% +just a constant so we impose that this + + + align:start position:0% +just a constant so we impose that this +one's equal to a constant so then here + + align:start position:0% +one's equal to a constant so then here + + + align:start position:0% +one's equal to a constant so then here +that we have something we we there's no + + align:start position:0% +that we have something we we there's no + + + align:start position:0% +that we have something we we there's no +parameter in this term that we need to + + align:start position:0% +parameter in this term that we need to + + + align:start position:0% +parameter in this term that we need to +estimate under the null so we just + + align:start position:0% +estimate under the null so we just + + + align:start position:0% +estimate under the null so we just +subtract the constant times X1 from the + + align:start position:0% +subtract the constant times X1 from the + + + align:start position:0% +subtract the constant times X1 from the +dependent variable and rerun that + + align:start position:0% +dependent variable and rerun that + + + align:start position:0% +dependent variable and rerun that +regression that's our restricted + + align:start position:0% +regression that's our restricted + + + align:start position:0% +regression that's our restricted +regression okay does that make sense + + align:start position:0% +regression okay does that make sense + + + align:start position:0% +regression okay does that make sense +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so going back we estimate the + + align:start position:0% +so so going back we estimate the + + + align:start position:0% +so so going back we estimate the +unrestricted model we estim we impose + + align:start position:0% +unrestricted model we estim we impose + + + align:start position:0% +unrestricted model we estim we impose +restrictions and estimate that model and + + align:start position:0% +restrictions and estimate that model and + + + align:start position:0% +restrictions and estimate that model and +then we compare the goodness of fit and + + align:start position:0% +then we compare the goodness of fit and + + + align:start position:0% +then we compare the goodness of fit and +if the goodness of fit is not very + + align:start position:0% +if the goodness of fit is not very + + + align:start position:0% +if the goodness of fit is not very +different we don't reject the null if + + align:start position:0% +different we don't reject the null if + + + align:start position:0% +different we don't reject the null if +it's very different we reject the null + + align:start position:0% +it's very different we reject the null + + + align:start position:0% +it's very different we reject the null +in particular this test statistic which + + align:start position:0% +in particular this test statistic which + + + align:start position:0% +in particular this test statistic which +which is basically on the the numerator + + align:start position:0% +which is basically on the the numerator + + + align:start position:0% +which is basically on the the numerator +has the difference in the sum of square + + align:start position:0% +has the difference in the sum of square + + + align:start position:0% +has the difference in the sum of square +the restricted and unrestricted sum of + + align:start position:0% +the restricted and unrestricted sum of + + + align:start position:0% +the restricted and unrestricted sum of +squares and then in the denominator has + + align:start position:0% +squares and then in the denominator has + + + align:start position:0% +squares and then in the denominator has +the unrestricted sum of squares this is + + align:start position:0% +the unrestricted sum of squares this is + + + align:start position:0% +the unrestricted sum of squares this is +how we form the test statistic and it + + align:start position:0% +how we form the test statistic and it + + + align:start position:0% +how we form the test statistic and it +turns out that that has an F + + align:start position:0% +turns out that that has an F + + + align:start position:0% +turns out that that has an F +distribution under the null and we + + align:start position:0% +distribution under the null and we + + + align:start position:0% +distribution under the null and we +reject uh the null for large values of + + align:start position:0% +reject uh the null for large values of + + + align:start position:0% +reject uh the null for large values of +this test statistic okay \ No newline at end of file diff --git a/YKfoSx16mXk.txt b/YKfoSx16mXk.txt new file mode 100644 index 0000000000000000000000000000000000000000..f7ddf1e8ab4e028f8651d2b94b75386015c823ad --- /dev/null +++ b/YKfoSx16mXk.txt @@ -0,0 +1,6499 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +today I'm going to go over a lot of + + align:start position:0% +today I'm going to go over a lot of + + + align:start position:0% +today I'm going to go over a lot of +material that you already know and to + + align:start position:0% +material that you already know and to + + + align:start position:0% +material that you already know and to +work an example with non-degenerate + + align:start position:0% +work an example with non-degenerate + + + align:start position:0% +work an example with non-degenerate +perturbation theory at the this will + + align:start position:0% +perturbation theory at the this will + + + align:start position:0% +perturbation theory at the this will +give me an excuse to use interspersed + + align:start position:0% +give me an excuse to use interspersed + + + align:start position:0% +give me an excuse to use interspersed +matrix and operator notation and one of + + align:start position:0% +matrix and operator notation and one of + + + align:start position:0% +matrix and operator notation and one of +the things that you will be doing is + + align:start position:0% +the things that you will be doing is + + + align:start position:0% +the things that you will be doing is +dealing with infinite matrices and we + + align:start position:0% +dealing with infinite matrices and we + + + align:start position:0% +dealing with infinite matrices and we +don't diagonalize infinite matrices but + + align:start position:0% +don't diagonalize infinite matrices but + + + align:start position:0% +don't diagonalize infinite matrices but +the picture of an infinite matrix is + + align:start position:0% +the picture of an infinite matrix is + + + align:start position:0% +the picture of an infinite matrix is +useful in guiding intuition and and so + + align:start position:0% +useful in guiding intuition and and so + + + align:start position:0% +useful in guiding intuition and and so +we have to know about what those + + align:start position:0% +we have to know about what those + + + align:start position:0% +we have to know about what those +pictures mean and how to construct them + + align:start position:0% +pictures mean and how to construct them + + + align:start position:0% +pictures mean and how to construct them +from things that are seemed to be + + align:start position:0% +from things that are seemed to be + + + align:start position:0% +from things that are seemed to be +obvious okay the problem I want to spend + + align:start position:0% +obvious okay the problem I want to spend + + + align:start position:0% +obvious okay the problem I want to spend +most of my time on is an example of a + + align:start position:0% +most of my time on is an example of a + + + align:start position:0% +most of my time on is an example of a +real molecular potential which is + + align:start position:0% +real molecular potential which is + + + align:start position:0% +real molecular potential which is +quadratic but with a cubic and a quartic + + align:start position:0% +quadratic but with a cubic and a quartic + + + align:start position:0% +quadratic but with a cubic and a quartic +perturbation term and these are this is + + align:start position:0% +perturbation term and these are this is + + + align:start position:0% +perturbation term and these are this is +a simpler problem than what I talked + + align:start position:0% +a simpler problem than what I talked + + + align:start position:0% +a simpler problem than what I talked +about last time the last time I really + + align:start position:0% +about last time the last time I really + + + align:start position:0% +about last time the last time I really +wanted to set the stage for what you can + + align:start position:0% +wanted to set the stage for what you can + + + align:start position:0% +wanted to set the stage for what you can +do with with non degenerate perturbation + + align:start position:0% +do with with non degenerate perturbation + + + align:start position:0% +do with with non degenerate perturbation +theory and this is going to be more of a + + align:start position:0% +theory and this is going to be more of a + + + align:start position:0% +theory and this is going to be more of a +specific dealing with a specific problem + + align:start position:0% +specific dealing with a specific problem + + + align:start position:0% +specific dealing with a specific problem +and now the algebra does not get simpler + + align:start position:0% +and now the algebra does not get simpler + + + align:start position:0% +and now the algebra does not get simpler +and so it's easy to get lost in the + + align:start position:0% +and so it's easy to get lost in the + + + align:start position:0% +and so it's easy to get lost in the +algebra and so I will give you some + + align:start position:0% +algebra and so I will give you some + + + align:start position:0% +algebra and so I will give you some +rules about what to expect when you have + + align:start position:0% +rules about what to expect when you have + + + align:start position:0% +rules about what to expect when you have +a potential like this and how does that + + align:start position:0% +a potential like this and how does that + + + align:start position:0% +a potential like this and how does that +come out of time to have non degenerate + + align:start position:0% +come out of time to have non degenerate + + + align:start position:0% +come out of time to have non degenerate +perturbation theory now everything that + + align:start position:0% +perturbation theory now everything that + + + align:start position:0% +perturbation theory now everything that +we know about molecules comes from + + align:start position:0% +we know about molecules comes from + + + align:start position:0% +we know about molecules comes from +spectroscopy that means transitions + + align:start position:0% +spectroscopy that means transitions + + + align:start position:0% +spectroscopy that means transitions +between energy levels and so well what + + align:start position:0% +between energy levels and so well what + + + align:start position:0% +between energy levels and so well what +how does how do they happen + + align:start position:0% +how does how do they happen + + + align:start position:0% +how does how do they happen +we can lead into that by talking about + + align:start position:0% +we can lead into that by talking about + + + align:start position:0% +we can lead into that by talking about +the stark effect which is the + + align:start position:0% +the stark effect which is the + + + align:start position:0% +the stark effect which is the +interaction of an electric field with a + + align:start position:0% +interaction of an electric field with a + + + align:start position:0% +interaction of an electric field with a +dipole in the molecule and and so most + + align:start position:0% +dipole in the molecule and and so most + + + align:start position:0% +dipole in the molecule and and so most +transitions are caused by a time + + align:start position:0% +transitions are caused by a time + + + align:start position:0% +transitions are caused by a time +dependent electric field which somehow + + align:start position:0% +dependent electric field which somehow + + + align:start position:0% +dependent electric field which somehow +interacts with the the molecule through + + align:start position:0% +interacts with the the molecule through + + + align:start position:0% +interacts with the the molecule through +its dipole moment and so you'll begin to + + align:start position:0% +its dipole moment and so you'll begin to + + + align:start position:0% +its dipole moment and so you'll begin to +see that today okay last time + + align:start position:0% +see that today okay last time + + + align:start position:0% +see that today okay last time +I derived the formulas for a + + align:start position:0% +I derived the formulas for a + + + align:start position:0% +I derived the formulas for a +non-degenerate perturbation theory now + + align:start position:0% +non-degenerate perturbation theory now + + + align:start position:0% +non-degenerate perturbation theory now +I'm a little bit crazy and I really + + align:start position:0% +I'm a little bit crazy and I really + + + align:start position:0% +I'm a little bit crazy and I really +believe in perturbation theory most of + + align:start position:0% +believe in perturbation theory most of + + + align:start position:0% +believe in perturbation theory most of +the textbooks say well let's just stop + + align:start position:0% +the textbooks say well let's just stop + + + align:start position:0% +the textbooks say well let's just stop +here at the first order correction to + + align:start position:0% +here at the first order correction to + + + align:start position:0% +here at the first order correction to +the energy levels and you get nothing + + align:start position:0% +the energy levels and you get nothing + + + align:start position:0% +the energy levels and you get nothing +from that except the same on effect + + align:start position:0% +from that except the same on effect + + + align:start position:0% +from that except the same on effect +which is kind of important for NMR but + + align:start position:0% +which is kind of important for NMR but + + + align:start position:0% +which is kind of important for NMR but +in terms of what molecules do you you + + align:start position:0% +in terms of what molecules do you you + + + align:start position:0% +in terms of what molecules do you you +need this too okay and this is equal to + + align:start position:0% +need this too okay and this is equal to + + + align:start position:0% +need this too okay and this is equal to +the zero order energy the first I'm + + align:start position:0% +the zero order energy the first I'm + + + align:start position:0% +the zero order energy the first I'm +sorry the zero order energy which comes + + align:start position:0% +sorry the zero order energy which comes + + + align:start position:0% +sorry the zero order energy which comes +from an exactly cell problem and then + + align:start position:0% + + + + align:start position:0% + +the diagonal matrix element of the the + + align:start position:0% +the diagonal matrix element of the the + + + align:start position:0% +the diagonal matrix element of the the +everything that's bad in the world the + + align:start position:0% +everything that's bad in the world the + + + align:start position:0% +everything that's bad in the world the +first order Hamiltonian and then we have + + align:start position:0% +first order Hamiltonian and then we have + + + align:start position:0% +first order Hamiltonian and then we have +this complicated looking thing m92 the + + align:start position:0% +this complicated looking thing m92 the + + + align:start position:0% +this complicated looking thing m92 the +end of H + + align:start position:0% + + + + align:start position:0% + +zero now the only thing that you might + + align:start position:0% +zero now the only thing that you might + + + align:start position:0% +zero now the only thing that you might +forget about in this kind of a formula + + align:start position:0% +forget about in this kind of a formula + + + align:start position:0% +forget about in this kind of a formula +is is it n before M or the other way + + align:start position:0% +is is it n before M or the other way + + + align:start position:0% +is is it n before M or the other way +around and what we know is okay here's + + align:start position:0% +around and what we know is okay here's + + + align:start position:0% +around and what we know is okay here's +the nth level and here is the M flow and + + align:start position:0% +the nth level and here is the M flow and + + + align:start position:0% +the nth level and here is the M flow and +the interaction causes this level to be + + align:start position:0% +the interaction causes this level to be + + + align:start position:0% +the interaction causes this level to be +pushed down so if the M is above the nth + + align:start position:0% +pushed down so if the M is above the nth + + + align:start position:0% +pushed down so if the M is above the nth +level this denominator will be negative + + align:start position:0% +level this denominator will be negative + + + align:start position:0% +level this denominator will be negative +and that causes the pushing down and so + + align:start position:0% +and that causes the pushing down and so + + + align:start position:0% +and that causes the pushing down and so +if you remember the idea of perturbation + + align:start position:0% +if you remember the idea of perturbation + + + align:start position:0% +if you remember the idea of perturbation +theory that things interact and they one + + align:start position:0% +theory that things interact and they one + + + align:start position:0% +theory that things interact and they one +level gets pushed down the other level + + align:start position:0% +level gets pushed down the other level + + + align:start position:0% +level gets pushed down the other level +gets pushed up equal and opposite you + + align:start position:0% +gets pushed up equal and opposite you + + + align:start position:0% +gets pushed up equal and opposite you +can you can correct your flaws of memory + + align:start position:0% +can you can correct your flaws of memory + + + align:start position:0% +can you can correct your flaws of memory +on the witch which comes first and we + + align:start position:0% +on the witch which comes first and we + + + align:start position:0% +on the witch which comes first and we +can write the wave function as an eigen + + align:start position:0% +can write the wave function as an eigen + + + align:start position:0% +can write the wave function as an eigen +function of the exactly self problem + + align:start position:0% +function of the exactly self problem + + + align:start position:0% +function of the exactly self problem +plus a term M not equal to n of x sigh + + align:start position:0% +plus a term M not equal to n of x sigh + + + align:start position:0% +plus a term M not equal to n of x sigh +and now the reason this sum does not + + align:start position:0% +and now the reason this sum does not + + + align:start position:0% +and now the reason this sum does not +include the nth level is well if you did + + align:start position:0% +include the nth level is well if you did + + + align:start position:0% +include the nth level is well if you did +this denominator would blow up and you + + align:start position:0% +this denominator would blow up and you + + + align:start position:0% +this denominator would blow up and you +don't need the nth level because you've + + align:start position:0% +don't need the nth level because you've + + + align:start position:0% +don't need the nth level because you've +already got it here so these are the + + align:start position:0% +already got it here so these are the + + + align:start position:0% +already got it here so these are the +formulas and we had it we had said okay + + align:start position:0% +formulas and we had it we had said okay + + + align:start position:0% +formulas and we had it we had said okay +we're going to write the Hamiltonian as + + align:start position:0% +we're going to write the Hamiltonian as + + + align:start position:0% +we're going to write the Hamiltonian as +H 0 plus h 1 and this is an exactly + + align:start position:0% +H 0 plus h 1 and this is an exactly + + + align:start position:0% +H 0 plus h 1 and this is an exactly +solve problem + + align:start position:0% +solve problem + + + align:start position:0% +solve problem +this is everything else now some people + + align:start position:0% +this is everything else now some people + + + align:start position:0% +this is everything else now some people +will sort this out into small everything + + align:start position:0% +will sort this out into small everything + + + align:start position:0% +will sort this out into small everything +else and big everything else but it's + + align:start position:0% +else and big everything else but it's + + + align:start position:0% +else and big everything else but it's +foolish because all that does is + + align:start position:0% +foolish because all that does is + + + align:start position:0% +foolish because all that does is +multiply the algebra in a horrible way + + align:start position:0% +multiply the algebra in a horrible way + + + align:start position:0% +multiply the algebra in a horrible way +and + + align:start position:0% +and + + + align:start position:0% +and +you know care anyway you just know that + + align:start position:0% +you know care anyway you just know that + + + align:start position:0% +you know care anyway you just know that +the stuff that's not in this exactly + + align:start position:0% +the stuff that's not in this exactly + + + align:start position:0% +the stuff that's not in this exactly +cell problem it's treated here and + + align:start position:0% +cell problem it's treated here and + + + align:start position:0% +cell problem it's treated here and +you're going to know in principle how to + + align:start position:0% +you're going to know in principle how to + + + align:start position:0% +you're going to know in principle how to +deal with it and there'll be some small + + align:start position:0% +deal with it and there'll be some small + + + align:start position:0% +deal with it and there'll be some small +problems that you know how to deal with + + align:start position:0% +problems that you know how to deal with + + + align:start position:0% +problems that you know how to deal with +okay and there's a rule that H and M 1 + + align:start position:0% +okay and there's a rule that H and M 1 + + + align:start position:0% +okay and there's a rule that H and M 1 +over E and 0 minus e m 0 absolute value + + align:start position:0% +over E and 0 minus e m 0 absolute value + + + align:start position:0% +over E and 0 minus e m 0 absolute value +it's much less than 1 that's what we + + align:start position:0% +it's much less than 1 that's what we + + + align:start position:0% +it's much less than 1 that's what we +mean yes ok you can say well we've got + + align:start position:0% +mean yes ok you can say well we've got + + + align:start position:0% +mean yes ok you can say well we've got +things that that are important that they + + align:start position:0% +things that that are important that they + + + align:start position:0% +things that that are important that they +obviously affect the energy levels and + + align:start position:0% +obviously affect the energy levels and + + + align:start position:0% +obviously affect the energy levels and +there's things that are smaller like + + align:start position:0% +there's things that are smaller like + + + align:start position:0% +there's things that are smaller like +hyperfine structure and when you use the + + align:start position:0% +hyperfine structure and when you use the + + + align:start position:0% +hyperfine structure and when you use the +word hyper you generally mean it's small + + align:start position:0% +word hyper you generally mean it's small + + + align:start position:0% +word hyper you generally mean it's small +and and so what ends up happening is + + align:start position:0% +and and so what ends up happening is + + + align:start position:0% +and and so what ends up happening is +that you do the big picture and then you + + align:start position:0% +that you do the big picture and then you + + + align:start position:0% +that you do the big picture and then you +see some more details but it's only a + + align:start position:0% +see some more details but it's only a + + + align:start position:0% +see some more details but it's only a +very small number of people who actually + + align:start position:0% +very small number of people who actually + + + align:start position:0% +very small number of people who actually +segregate the badness into real bad and + + align:start position:0% +segregate the badness into real bad and + + + align:start position:0% +segregate the badness into real bad and +not so bad ok so this works only when + + align:start position:0% +not so bad ok so this works only when + + + align:start position:0% +not so bad ok so this works only when +this off diagonal matrix element is + + align:start position:0% +this off diagonal matrix element is + + + align:start position:0% +this off diagonal matrix element is +smaller than the energy difference and + + align:start position:0% +smaller than the energy difference and + + + align:start position:0% +smaller than the energy difference and +that's going to be true and now here's + + align:start position:0% +that's going to be true and now here's + + + align:start position:0% +that's going to be true and now here's +an infinite matrix and we're interested + + align:start position:0% +an infinite matrix and we're interested + + + align:start position:0% +an infinite matrix and we're interested +in a certain space of quite a state + + align:start position:0% +in a certain space of quite a state + + + align:start position:0% +in a certain space of quite a state +space which are our experiments are + + align:start position:0% +space which are our experiments are + + + align:start position:0% +space which are our experiments are +designed to measure and it depends on + + align:start position:0% +designed to measure and it depends on + + + align:start position:0% +designed to measure and it depends on +what you what experiment you do this + + align:start position:0% +what you what experiment you do this + + + align:start position:0% +what you what experiment you do this +might be here it might be somewhere in + + align:start position:0% +might be here it might be somewhere in + + + align:start position:0% +might be here it might be somewhere in +the middle and the rest is we're not + + align:start position:0% +the middle and the rest is we're not + + + align:start position:0% +the middle and the rest is we're not +interested because it's far away because + + align:start position:0% +interested because it's far away because + + + align:start position:0% +interested because it's far away because +the energy denominator is so large that + + align:start position:0% +the energy denominator is so large that + + + align:start position:0% +the energy denominator is so large that +the effect on the energy levels can be + + align:start position:0% +the effect on the energy levels can be + + + align:start position:0% +the effect on the energy levels can be +ignored + + align:start position:0% +ignored + + + align:start position:0% +ignored +or you can say well we're not really + + align:start position:0% +or you can say well we're not really + + + align:start position:0% +or you can say well we're not really +ignoring it we're folding the effect of + + align:start position:0% +ignoring it we're folding the effect of + + + align:start position:0% +ignoring it we're folding the effect of +all these levels through the matrix + + align:start position:0% +all these levels through the matrix + + + align:start position:0% +all these levels through the matrix +elements in here into here by + + align:start position:0% +elements in here into here by + + + align:start position:0% +elements in here into here by +second-order perturbation theory we + + align:start position:0% +second-order perturbation theory we + + + align:start position:0% +second-order perturbation theory we +could in principle do that we certainly + + align:start position:0% +could in principle do that we certainly + + + align:start position:0% +could in principle do that we certainly +are allowed to think that we're getting + + align:start position:0% +are allowed to think that we're getting + + + align:start position:0% +are allowed to think that we're getting +rid of this state space by in principle + + align:start position:0% +rid of this state space by in principle + + + align:start position:0% +rid of this state space by in principle +folding it into this block now in this + + align:start position:0% +folding it into this block now in this + + + align:start position:0% +folding it into this block now in this +block of levels that we are we care + + align:start position:0% +block of levels that we are we care + + + align:start position:0% +block of levels that we are we care +about now I always like to draw these + + align:start position:0% +about now I always like to draw these + + + align:start position:0% +about now I always like to draw these +infinite matrices or these matrices by + + align:start position:0% +infinite matrices or these matrices by + + + align:start position:0% +infinite matrices or these matrices by +just saying okay here's the diagonal and + + align:start position:0% +just saying okay here's the diagonal and + + + align:start position:0% +just saying okay here's the diagonal and +there might be a couple of levels within + + align:start position:0% +there might be a couple of levels within + + + align:start position:0% +there might be a couple of levels within +this state space we're interested in + + align:start position:0% +this state space we're interested in + + + align:start position:0% +this state space we're interested in +which because of accident or because of + + align:start position:0% +which because of accident or because of + + + align:start position:0% +which because of accident or because of +something evil their energy denominator + + align:start position:0% +something evil their energy denominator + + + align:start position:0% +something evil their energy denominator +is small compared to the energy the zero + + align:start position:0% +is small compared to the energy the zero + + + align:start position:0% +is small compared to the energy the zero +order energy differences but that's + + align:start position:0% +order energy differences but that's + + + align:start position:0% +order energy differences but that's +usually true for only a couple of a few + + align:start position:0% +usually true for only a couple of a few + + + align:start position:0% +usually true for only a couple of a few +accidentally degenerate states and we + + align:start position:0% +accidentally degenerate states and we + + + align:start position:0% +accidentally degenerate states and we +deal with them by using the machinery we + + align:start position:0% +deal with them by using the machinery we + + + align:start position:0% +deal with them by using the machinery we +obtained from the two-level problem and + + align:start position:0% +obtained from the two-level problem and + + + align:start position:0% +obtained from the two-level problem and +so there we're actually diagonalizing a + + align:start position:0% +so there we're actually diagonalizing a + + + align:start position:0% +so there we're actually diagonalizing a +small dimension matrix we're not + + align:start position:0% +small dimension matrix we're not + + + align:start position:0% +small dimension matrix we're not +diagonally thinking our computer is + + align:start position:0% +diagonally thinking our computer is + + + align:start position:0% +diagonally thinking our computer is +diagonalize again you really don't care + + align:start position:0% +diagonalize again you really don't care + + + align:start position:0% +diagonalize again you really don't care +how it's done because you have a machine + + align:start position:0% +how it's done because you have a machine + + + align:start position:0% +how it's done because you have a machine +that will will will solve this like + + align:start position:0% +that will will will solve this like + + + align:start position:0% +that will will will solve this like +difficulty and so it's okay for this + + align:start position:0% +difficulty and so it's okay for this + + + align:start position:0% +difficulty and so it's okay for this +rule to be violated but so what happens + + align:start position:0% +rule to be violated but so what happens + + + align:start position:0% +rule to be violated but so what happens +suppose we have two levels and just want + + align:start position:0% +suppose we have two levels and just want + + + align:start position:0% +suppose we have two levels and just want +to make sure I use the same notation as + + align:start position:0% +to make sure I use the same notation as + + + align:start position:0% +to make sure I use the same notation as +in the notes so here we have the two + + align:start position:0% +in the notes so here we have the two + + + align:start position:0% +in the notes so here we have the two +zero order levels and they interact and + + align:start position:0% +zero order levels and they interact and + + + align:start position:0% +zero order levels and they interact and +repel each other equal and opposite + + align:start position:0% +repel each other equal and opposite + + + align:start position:0% +repel each other equal and opposite +amounts and these states which are D 2 + + align:start position:0% +amounts and these states which are D 2 + + + align:start position:0% +amounts and these states which are D 2 +and E 1 are not pure state 2 + + align:start position:0% +and E 1 are not pure state 2 + + + align:start position:0% +and E 1 are not pure state 2 +they have a mixture of state one in them + + align:start position:0% +they have a mixture of state one in them + + + align:start position:0% +they have a mixture of state one in them +now in spectroscopy we always observe + + align:start position:0% +now in spectroscopy we always observe + + + align:start position:0% +now in spectroscopy we always observe +these levels by transitions and so + + align:start position:0% +these levels by transitions and so + + + align:start position:0% +these levels by transitions and so +suppose we have state zero down here and + + align:start position:0% + + + + align:start position:0% + +let us say that this transition between + + align:start position:0% +let us say that this transition between + + + align:start position:0% +let us say that this transition between +the the zero level and the zero order + + align:start position:0% +the the zero level and the zero order + + + align:start position:0% +the the zero level and the zero order +level one is allowed and I'll symbolize + + align:start position:0% +level one is allowed and I'll symbolize + + + align:start position:0% +level one is allowed and I'll symbolize +that by 1 0 mu 1 0 is not equal to 0 and + + align:start position:0% +that by 1 0 mu 1 0 is not equal to 0 and + + + align:start position:0% +that by 1 0 mu 1 0 is not equal to 0 and +the transition between this 0 this level + + align:start position:0% +the transition between this 0 this level + + + align:start position:0% +the transition between this 0 this level +and this is our order level is forbidden + + align:start position:0% +and this is our order level is forbidden + + + align:start position:0% +and this is our order level is forbidden +mu to 0 is equal to 0 so we call this a + + align:start position:0% +mu to 0 is equal to 0 so we call this a + + + align:start position:0% +mu to 0 is equal to 0 so we call this a +dark state and a bright state and now + + align:start position:0% +dark state and a bright state and now + + + align:start position:0% +dark state and a bright state and now +these two states interact and we have + + align:start position:0% +these two states interact and we have + + + align:start position:0% +these two states interact and we have +mixed States + + align:start position:0% +mixed States + + + align:start position:0% +mixed States +so the real eigenstates you wouldn't + + align:start position:0% +so the real eigenstates you wouldn't + + + align:start position:0% +so the real eigenstates you wouldn't +have expected to see this level in the + + align:start position:0% +have expected to see this level in the + + + align:start position:0% +have expected to see this level in the +spectrum but you do because it's + + align:start position:0% +spectrum but you do because it's + + + align:start position:0% +spectrum but you do because it's +borrowed some bright character through + + align:start position:0% +borrowed some bright character through + + + align:start position:0% +borrowed some bright character through +the perturbation interaction and so + + align:start position:0% +the perturbation interaction and so + + + align:start position:0% +the perturbation interaction and so +there's two surprises one is everything + + align:start position:0% +there's two surprises one is everything + + + align:start position:0% +there's two surprises one is everything +is sort of describable by a simple set + + align:start position:0% +is sort of describable by a simple set + + + align:start position:0% +is sort of describable by a simple set +of equations and then there's a couple + + align:start position:0% +of equations and then there's a couple + + + align:start position:0% +of equations and then there's a couple +of deviations and there's some extra + + align:start position:0% +of deviations and there's some extra + + + align:start position:0% +of deviations and there's some extra +levels that appear that's very that's + + align:start position:0% +levels that appear that's very that's + + + align:start position:0% +levels that appear that's very that's +information very rich because if it's + + align:start position:0% +information very rich because if it's + + + align:start position:0% +information very rich because if it's +dark you can't see it it's not a ghost + + align:start position:0% +dark you can't see it it's not a ghost + + + align:start position:0% +dark you can't see it it's not a ghost +it's there but you can't see it well the + + align:start position:0% +it's there but you can't see it well the + + + align:start position:0% +it's there but you can't see it well the +perturbation somehow pulls that + + align:start position:0% +perturbation somehow pulls that + + + align:start position:0% +perturbation somehow pulls that +sometimes pulls the curtain back and + + align:start position:0% +sometimes pulls the curtain back and + + + align:start position:0% +sometimes pulls the curtain back and +enables you to see stuff you need to + + align:start position:0% +enables you to see stuff you need to + + + align:start position:0% +enables you to see stuff you need to +know about now you can imagine exciting + + align:start position:0% +know about now you can imagine exciting + + + align:start position:0% +know about now you can imagine exciting +this two-level system with a short pulse + + align:start position:0% +this two-level system with a short pulse + + + align:start position:0% +this two-level system with a short pulse +of light where the uncertainty + + align:start position:0% +of light where the uncertainty + + + align:start position:0% +of light where the uncertainty +broadening of the short pulse of light + + align:start position:0% +broadening of the short pulse of light + + + align:start position:0% +broadening of the short pulse of light +covers these two eigenstates what + + align:start position:0% +covers these two eigenstates what + + + align:start position:0% +covers these two eigenstates what +happens then is you get quantum beats + + align:start position:0% +happens then is you get quantum beats + + + align:start position:0% +happens then is you get quantum beats +and that's going to be on the exam + + align:start position:0% + + + + align:start position:0% + +okay so this is a local perturbation + + align:start position:0% +okay so this is a local perturbation + + + align:start position:0% +okay so this is a local perturbation +it's just something in here that that + + align:start position:0% +it's just something in here that that + + + align:start position:0% +it's just something in here that that +spoils the general rule but it's very + + align:start position:0% +spoils the general rule but it's very + + + align:start position:0% +spoils the general rule but it's very +information-rich and it also is to + + align:start position:0% +information-rich and it also is to + + + align:start position:0% +information-rich and it also is to +pedagogically fun okay so now I'm going + + align:start position:0% +pedagogically fun okay so now I'm going + + + align:start position:0% +pedagogically fun okay so now I'm going +to talk about stuff that I've talked + + align:start position:0% +to talk about stuff that I've talked + + + align:start position:0% +to talk about stuff that I've talked +about before but I'm going to go a + + align:start position:0% +about before but I'm going to go a + + + align:start position:0% +about before but I'm going to go a +little deeper and slower and and so + + align:start position:0% +little deeper and slower and and so + + + align:start position:0% +little deeper and slower and and so +let's let's do this problem we have a + + align:start position:0% +let's let's do this problem we have a + + + align:start position:0% +let's let's do this problem we have a +potential and for molecules we tend to + + align:start position:0% +potential and for molecules we tend to + + + align:start position:0% +potential and for molecules we tend to +use Q rather than R or X as the + + align:start position:0% +use Q rather than R or X as the + + + align:start position:0% +use Q rather than R or X as the +displacement from equilibrium the + + align:start position:0% +displacement from equilibrium the + + + align:start position:0% +displacement from equilibrium the +harmonic oscillator coordinate and it's + + align:start position:0% +harmonic oscillator coordinate and it's + + + align:start position:0% +harmonic oscillator coordinate and it's +the same thing we have okay so this is + + align:start position:0% +the same thing we have okay so this is + + + align:start position:0% +the same thing we have okay so this is +an exactly solved problem and this is + + align:start position:0% +an exactly solved problem and this is + + + align:start position:0% +an exactly solved problem and this is +something extra and so this is a cubic + + align:start position:0% +something extra and so this is a cubic + + + align:start position:0% +something extra and so this is a cubic +anharmonicity and this is a quartic + + align:start position:0% +anharmonicity and this is a quartic + + + align:start position:0% +anharmonicity and this is a quartic +anharmonicity in the previous lecture I + + align:start position:0% +anharmonicity in the previous lecture I + + + align:start position:0% +anharmonicity in the previous lecture I +talked about a mnemonic couplings + + align:start position:0% +talked about a mnemonic couplings + + + align:start position:0% +talked about a mnemonic couplings +between different modes of the same + + align:start position:0% +between different modes of the same + + + align:start position:0% +between different modes of the same +polyatomic molecule here this is really + + align:start position:0% +polyatomic molecule here this is really + + + align:start position:0% +polyatomic molecule here this is really +a simpler problem and I probably should + + align:start position:0% +a simpler problem and I probably should + + + align:start position:0% +a simpler problem and I probably should +have talked about it first but I didn't + + align:start position:0% +have talked about it first but I didn't + + + align:start position:0% +have talked about it first but I didn't +because I'm going to go deeper here then + + align:start position:0% +because I'm going to go deeper here then + + + align:start position:0% +because I'm going to go deeper here then +just the big picture which I described + + align:start position:0% +just the big picture which I described + + + align:start position:0% +just the big picture which I described +last time so we're going to have two + + align:start position:0% +last time so we're going to have two + + + align:start position:0% +last time so we're going to have two +terms that we are going to treat by + + align:start position:0% +terms that we are going to treat by + + + align:start position:0% +terms that we are going to treat by +perturbation theory and there are + + align:start position:0% +perturbation theory and there are + + + align:start position:0% +perturbation theory and there are +several important things here molecular + + align:start position:0% +several important things here molecular + + + align:start position:0% +several important things here molecular +potential looks like this not like that + + align:start position:0% +potential looks like this not like that + + + align:start position:0% +potential looks like this not like that +right this is bond breaking and it + + align:start position:0% +right this is bond breaking and it + + + align:start position:0% +right this is bond breaking and it +breaks at large displacement there's no + + align:start position:0% +breaks at large displacement there's no + + + align:start position:0% +breaks at large displacement there's no +such thing as upon breaking as you + + align:start position:0% +such thing as upon breaking as you + + + align:start position:0% +such thing as upon breaking as you +squeeze the molecules together so this + + align:start position:0% +squeeze the molecules together so this + + + align:start position:0% +squeeze the molecules together so this +is a crazy idea and how do you get an + + align:start position:0% +is a crazy idea and how do you get an + + + align:start position:0% +is a crazy idea and how do you get an +asymmetric potential well it's cubic and + + align:start position:0% +asymmetric potential well it's cubic and + + + align:start position:0% +asymmetric potential well it's cubic and +which sign of B is going to lead to this + + align:start position:0% +which sign of B is going to lead to this + + + align:start position:0% +which sign of B is going to lead to this +yes + + align:start position:0% +yes + + + align:start position:0% +yes +right okay now if we're really naive + + align:start position:0% +right okay now if we're really naive + + + align:start position:0% +right okay now if we're really naive +we're saying yeah negative is good but + + align:start position:0% +we're saying yeah negative is good but + + + align:start position:0% +we're saying yeah negative is good but +boom we ignore that we don't worry that + + align:start position:0% +boom we ignore that we don't worry that + + + align:start position:0% +boom we ignore that we don't worry that +if we took this seriously at large + + align:start position:0% +if we took this seriously at large + + + align:start position:0% +if we took this seriously at large +enough displacement the potential go to + + align:start position:0% +enough displacement the potential go to + + + align:start position:0% +enough displacement the potential go to +minus infinity we don't worry about + + align:start position:0% +minus infinity we don't worry about + + + align:start position:0% +minus infinity we don't worry about +tunneling through this barrier we just + + align:start position:0% +tunneling through this barrier we just + + + align:start position:0% +tunneling through this barrier we just +use this to give us something that has + + align:start position:0% +use this to give us something that has + + + align:start position:0% +use this to give us something that has +the right shape and that we can apply + + align:start position:0% +the right shape and that we can apply + + + align:start position:0% +the right shape and that we can apply +perturbation theory to and we're not + + align:start position:0% +perturbation theory to and we're not + + + align:start position:0% +perturbation theory to and we're not +going to worry about using perturbation + + align:start position:0% +going to worry about using perturbation + + + align:start position:0% +going to worry about using perturbation +theory to capture this tunneling at + + align:start position:0% +theory to capture this tunneling at + + + align:start position:0% +theory to capture this tunneling at +least not now and not in this course + + align:start position:0% +least not now and not in this course + + + align:start position:0% +least not now and not in this course +okay so so one thing is we have this + + align:start position:0% +okay so so one thing is we have this + + + align:start position:0% +okay so so one thing is we have this +term and there's there's something you + + align:start position:0% +term and there's there's something you + + + align:start position:0% +term and there's there's something you +know immediately about odd powers they + + align:start position:0% +know immediately about odd powers they + + + align:start position:0% +know immediately about odd powers they +never have Delta V equals zero matrix + + align:start position:0% +never have Delta V equals zero matrix + + + align:start position:0% +never have Delta V equals zero matrix +elements + + align:start position:0% +elements + + + align:start position:0% +elements +they never have diagonal elements and so + + align:start position:0% +they never have diagonal elements and so + + + align:start position:0% +they never have diagonal elements and so +they do not contribute to the energy in + + align:start position:0% +they do not contribute to the energy in + + + align:start position:0% +they do not contribute to the energy in +first order the only way you know the + + align:start position:0% +first order the only way you know the + + + align:start position:0% +first order the only way you know the +sign of this perturbation is from a + + align:start position:0% +sign of this perturbation is from a + + + align:start position:0% +sign of this perturbation is from a +nonzero first order contribution because + + align:start position:0% +nonzero first order contribution because + + + align:start position:0% +nonzero first order contribution because +when you do second order perturbation + + align:start position:0% +when you do second order perturbation + + + align:start position:0% +when you do second order perturbation +Theory the matrix element gets squared + + align:start position:0% +Theory the matrix element gets squared + + + align:start position:0% +Theory the matrix element gets squared +and the sign information is lost so + + align:start position:0% +and the sign information is lost so + + + align:start position:0% +and the sign information is lost so +there's nothing so far that tells you + + align:start position:0% +there's nothing so far that tells you + + + align:start position:0% +there's nothing so far that tells you +what the sign of B is and the energy + + align:start position:0% +what the sign of B is and the energy + + + align:start position:0% +what the sign of B is and the energy +level pattern that you would obtain from + + align:start position:0% +level pattern that you would obtain from + + + align:start position:0% +level pattern that you would obtain from +either sign of B would be the same it's + + align:start position:0% +either sign of B would be the same it's + + + align:start position:0% +either sign of B would be the same it's +just one one of the signs is completely + + align:start position:0% +just one one of the signs is completely + + + align:start position:0% +just one one of the signs is completely +ridiculous + + align:start position:0% +ridiculous + + + align:start position:0% +ridiculous +now Q to the fourth has selection rules + + align:start position:0% +now Q to the fourth has selection rules + + + align:start position:0% +now Q to the fourth has selection rules +Delta V of 4 to 0 minus 2 and minus 4 so + + align:start position:0% +Delta V of 4 to 0 minus 2 and minus 4 so + + + align:start position:0% +Delta V of 4 to 0 minus 2 and minus 4 so +that Delta P of 0 term + + align:start position:0% +that Delta P of 0 term + + + align:start position:0% +that Delta P of 0 term +Center in first-order perturbation + + align:start position:0% +Center in first-order perturbation + + + align:start position:0% +Center in first-order perturbation +theory and so you can determine the sign + + align:start position:0% +theory and so you can determine the sign + + + align:start position:0% +theory and so you can determine the sign +of any even perturbation which is useful + + align:start position:0% +of any even perturbation which is useful + + + align:start position:0% +of any even perturbation which is useful +now what does this do well one thing + + align:start position:0% +now what does this do well one thing + + + align:start position:0% +now what does this do well one thing +that Q does is if this if if Q is if C + + align:start position:0% +that Q does is if this if if Q is if C + + + align:start position:0% +that Q does is if this if if Q is if C +is positive instead of having a harmonic + + align:start position:0% +is positive instead of having a harmonic + + + align:start position:0% +is positive instead of having a harmonic +oscillator it makes it steeper and if Q + + align:start position:0% +oscillator it makes it steeper and if Q + + + align:start position:0% +oscillator it makes it steeper and if Q +is negative it makes it flatter this is + + align:start position:0% +is negative it makes it flatter this is + + + align:start position:0% +is negative it makes it flatter this is +typical of bending vibrations and so + + align:start position:0% +typical of bending vibrations and so + + + align:start position:0% +typical of bending vibrations and so +bending vibrations tend to have flat + + align:start position:0% +bending vibrations tend to have flat + + + align:start position:0% +bending vibrations tend to have flat +bottom potentials but there's also + + align:start position:0% +bottom potentials but there's also + + + align:start position:0% +bottom potentials but there's also +something else suppose we have two + + align:start position:0% +something else suppose we have two + + + align:start position:0% +something else suppose we have two +electronic states now I'm cheating + + align:start position:0% +electronic states now I'm cheating + + + align:start position:0% +electronic states now I'm cheating +because I'm assuming you you'll accept + + align:start position:0% +because I'm assuming you you'll accept + + + align:start position:0% +because I'm assuming you you'll accept +the idea that there is something we + + align:start position:0% +the idea that there is something we + + + align:start position:0% +the idea that there is something we +haven't talked about yet but there are + + align:start position:0% +haven't talked about yet but there are + + + align:start position:0% +haven't talked about yet but there are +different potential curves and it's + + align:start position:0% +different potential curves and it's + + + align:start position:0% +different potential curves and it's +mostly true for polyatomic molecules + + align:start position:0% +mostly true for polyatomic molecules + + + align:start position:0% +mostly true for polyatomic molecules +these two states can't talk to each + + align:start position:0% +these two states can't talk to each + + + align:start position:0% +these two states can't talk to each +other at equilibrium because a symmetry + + align:start position:0% +other at equilibrium because a symmetry + + + align:start position:0% +other at equilibrium because a symmetry +exists that prevents that and as you + + align:start position:0% +exists that prevents that and as you + + + align:start position:0% +exists that prevents that and as you +move away from equilibrium there's a + + align:start position:0% +move away from equilibrium there's a + + + align:start position:0% +move away from equilibrium there's a +perturbation that gets larger and larger + + align:start position:0% +perturbation that gets larger and larger + + + align:start position:0% +perturbation that gets larger and larger +and as a result what happens is that + + align:start position:0% +and as a result what happens is that + + + align:start position:0% +and as a result what happens is that +this potential does something like that + + align:start position:0% + + + + align:start position:0% + +so you get a either a flattening or an + + align:start position:0% +so you get a either a flattening or an + + + align:start position:0% +so you get a either a flattening or an +actual extra pair of minima and this one + + align:start position:0% +actual extra pair of minima and this one + + + align:start position:0% +actual extra pair of minima and this one +gets sharper that's called the vibronic + + align:start position:0% +gets sharper that's called the vibronic + + + align:start position:0% +gets sharper that's called the vibronic +interaction and that's fairly important + + align:start position:0% +interaction and that's fairly important + + + align:start position:0% +interaction and that's fairly important +in polyatomic molecules but so we can + + align:start position:0% +in polyatomic molecules but so we can + + + align:start position:0% +in polyatomic molecules but so we can +begin to understand these things just by + + align:start position:0% +begin to understand these things just by + + + align:start position:0% +begin to understand these things just by +dealing with these terms in the + + align:start position:0% +dealing with these terms in the + + + align:start position:0% +dealing with these terms in the +potential okay + + align:start position:0% +potential okay + + + align:start position:0% +potential okay +so now we're off to the races and my + + align:start position:0% +so now we're off to the races and my + + + align:start position:0% +so now we're off to the races and my +goal here is to make you comfortable + + align:start position:0% +goal here is to make you comfortable + + + align:start position:0% +goal here is to make you comfortable +with either the operator or the matrix + + align:start position:0% +with either the operator or the matrix + + + align:start position:0% +with either the operator or the matrix +notation and so I'm going to go back and + + align:start position:0% +notation and so I'm going to go back and + + + align:start position:0% +notation and so I'm going to go back and +forth between them you know what might + + align:start position:0% +forth between them you know what might + + + align:start position:0% +forth between them you know what might +seem to be a random manner but okay now + + align:start position:0% +seem to be a random manner but okay now + + + align:start position:0% +seem to be a random manner but okay now +you know that a dagger now we can call + + align:start position:0% +you know that a dagger now we can call + + + align:start position:0% +you know that a dagger now we can call +it a dagger with a hat or we can call it + + align:start position:0% +it a dagger with a hat or we can call it + + + align:start position:0% +it a dagger with a hat or we can call it +a dagger double underline the old hat + + align:start position:0% +a dagger double underline the old hat + + + align:start position:0% +a dagger double underline the old hat +matrix operator and you know that this + + align:start position:0% +matrix operator and you know that this + + + align:start position:0% +matrix operator and you know that this +operates on V to give V plus one Sparrow + + align:start position:0% +operates on V to give V plus one Sparrow + + + align:start position:0% +operates on V to give V plus one Sparrow +side B plus one or in bracket notation + + align:start position:0% +side B plus one or in bracket notation + + + align:start position:0% +side B plus one or in bracket notation +we could write this as V plus 1 a dagger + + align:start position:0% +we could write this as V plus 1 a dagger + + + align:start position:0% +we could write this as V plus 1 a dagger +V now this is a shorthand it's a + + align:start position:0% +V now this is a shorthand it's a + + + align:start position:0% +V now this is a shorthand it's a +wonderful shorthand it's easier to draw + + align:start position:0% +wonderful shorthand it's easier to draw + + + align:start position:0% +wonderful shorthand it's easier to draw +this than wavefunctions but we have to + + align:start position:0% +this than wavefunctions but we have to + + + align:start position:0% +this than wavefunctions but we have to +know okay what does this look like in + + align:start position:0% +know okay what does this look like in + + + align:start position:0% +know okay what does this look like in +the matrix for a dagger so here is a + + align:start position:0% +the matrix for a dagger so here is a + + + align:start position:0% +the matrix for a dagger so here is a +dagger and it's a matrix and what goes + + align:start position:0% +dagger and it's a matrix and what goes + + + align:start position:0% +dagger and it's a matrix and what goes +in here + + align:start position:0% +in here + + + align:start position:0% +in here +well the first thing you do this is + + align:start position:0% +well the first thing you do this is + + + align:start position:0% +well the first thing you do this is +infinite so you need some sort of a way + + align:start position:0% +infinite so you need some sort of a way + + + align:start position:0% +infinite so you need some sort of a way +of drawing something that's infinite so + + align:start position:0% +of drawing something that's infinite so + + + align:start position:0% +of drawing something that's infinite so +that you understand what it is and so + + align:start position:0% +that you understand what it is and so + + + align:start position:0% +that you understand what it is and so +the first thing you do is you know that + + align:start position:0% +the first thing you do is you know that + + + align:start position:0% +the first thing you do is you know that +there is no all of the diagonal elements + + align:start position:0% +there is no all of the diagonal elements + + + align:start position:0% +there is no all of the diagonal elements +are 0 now most of the elements in this + + align:start position:0% +are 0 now most of the elements in this + + + align:start position:0% +are 0 now most of the elements in this +matrix are 0 and you don't want to draw + + align:start position:0% +matrix are 0 and you don't want to draw + + + align:start position:0% +matrix are 0 and you don't want to draw +them and because you'll just be spending + + align:start position:0% +them and because you'll just be spending + + + align:start position:0% +them and because you'll just be spending +all your time make it writing zeroes so + + align:start position:0% +all your time make it writing zeroes so + + + align:start position:0% +all your time make it writing zeroes so +we want a shorthand and so now this is a + + align:start position:0% +we want a shorthand and so now this is a + + + align:start position:0% +we want a shorthand and so now this is a +matrix element this is the row and this + + align:start position:0% +matrix element this is the row and this + + + align:start position:0% +matrix element this is the row and this +is the column and so where do I put this + + align:start position:0% +is the column and so where do I put this + + + align:start position:0% +is the column and so where do I put this +square root of V plus 1 + + align:start position:0% + + + + align:start position:0% + +so here we have the Rosso I I get + + align:start position:0% +so here we have the Rosso I I get + + + align:start position:0% +so here we have the Rosso I I get +confused about this so before I accept + + align:start position:0% +confused about this so before I accept + + + align:start position:0% +confused about this so before I accept +your answer which I want to reject I + + align:start position:0% +your answer which I want to reject I + + + align:start position:0% +your answer which I want to reject I +have to think carefully about it so let + + align:start position:0% +have to think carefully about it so let + + + align:start position:0% +have to think carefully about it so let +us say this is 0 and this is 1 so we + + align:start position:0% +us say this is 0 and this is 1 so we + + + align:start position:0% +us say this is 0 and this is 1 so we +have the 1 you're right + + align:start position:0% + + + + align:start position:0% + +okay and so we have the square root of 1 + + align:start position:0% +okay and so we have the square root of 1 + + + align:start position:0% +okay and so we have the square root of 1 +the square root of 2 square root of N + + align:start position:0% +the square root of 2 square root of N + + + align:start position:0% +the square root of 2 square root of N +and everything else is 0 so we can write + + align:start position:0% +and everything else is 0 so we can write + + + align:start position:0% +and everything else is 0 so we can write +big zeros so that's what this matrix + + align:start position:0% +big zeros so that's what this matrix + + + align:start position:0% +big zeros so that's what this matrix +looks like now if we're using computers + + align:start position:0% +looks like now if we're using computers + + + align:start position:0% +looks like now if we're using computers +instead of multiplying these matrices to + + align:start position:0% +instead of multiplying these matrices to + + + align:start position:0% +instead of multiplying these matrices to +have say Q to the 13th or via a dagger + + align:start position:0% +have say Q to the 13th or via a dagger + + + align:start position:0% +have say Q to the 13th or via a dagger +to the 13th you can just multiply these + + align:start position:0% +to the 13th you can just multiply these + + + align:start position:0% +to the 13th you can just multiply these +matrices it's an easy request for the + + align:start position:0% +matrices it's an easy request for the + + + align:start position:0% +matrices it's an easy request for the +computer it's a not such an easy request + + align:start position:0% +computer it's a not such an easy request + + + align:start position:0% +computer it's a not such an easy request +for you but you end up getting matrices + + align:start position:0% +for you but you end up getting matrices + + + align:start position:0% +for you but you end up getting matrices +when you have integer powers of these + + align:start position:0% +when you have integer powers of these + + + align:start position:0% +when you have integer powers of these +you get a matrix with a diagonal and + + align:start position:0% +you get a matrix with a diagonal and + + + align:start position:0% +you get a matrix with a diagonal and +then another diagonal separated by a + + align:start position:0% +then another diagonal separated by a + + + align:start position:0% +then another diagonal separated by a +diagonal of zeroes and so you know what + + align:start position:0% +diagonal of zeroes and so you know what + + + align:start position:0% +diagonal of zeroes and so you know what +these things are going to look like so + + align:start position:0% +these things are going to look like so + + + align:start position:0% +these things are going to look like so +you might ask okay what is it hey you + + align:start position:0% +you might ask okay what is it hey you + + + align:start position:0% +you might ask okay what is it hey you +look like and there are several ways to + + align:start position:0% +look like and there are several ways to + + + align:start position:0% +look like and there are several ways to +say what a is going to look like because + + align:start position:0% +say what a is going to look like because + + + align:start position:0% +say what a is going to look like because +it's the conjugate transpose of a dagger + + align:start position:0% + + + + align:start position:0% + +well these are all real numbers and so + + align:start position:0% +well these are all real numbers and so + + + align:start position:0% +well these are all real numbers and so +all you do is flip this on a stye agonal + + align:start position:0% +all you do is flip this on a stye agonal + + + align:start position:0% +all you do is flip this on a stye agonal +now you get a + + align:start position:0% + + + + align:start position:0% + +and then there's another actor in this + + align:start position:0% +and then there's another actor in this + + + align:start position:0% +and then there's another actor in this +game that's n the number operator and + + align:start position:0% +game that's n the number operator and + + + align:start position:0% +game that's n the number operator and +the number operator is going to be a hey + + align:start position:0% +the number operator is going to be a hey + + + align:start position:0% +the number operator is going to be a hey +dagger or is it gonna be a dagger a so + + align:start position:0% + + + + align:start position:0% + +which is it this yes okay one way to + + align:start position:0% +which is it this yes okay one way to + + + align:start position:0% +which is it this yes okay one way to +remember this is when you operate with + + align:start position:0% +remember this is when you operate with + + + align:start position:0% +remember this is when you operate with +either a or a dagger it connects to + + align:start position:0% +either a or a dagger it connects to + + + align:start position:0% +either a or a dagger it connects to +vibrational levels and the thing you put + + align:start position:0% +vibrational levels and the thing you put + + + align:start position:0% +vibrational levels and the thing you put +in the square root is the larger of the + + align:start position:0% +in the square root is the larger of the + + + align:start position:0% +in the square root is the larger of the +two quantum numbers okay so what would + + align:start position:0% +two quantum numbers okay so what would + + + align:start position:0% +two quantum numbers okay so what would +the number operator matrix look like so + + align:start position:0% +the number operator matrix look like so + + + align:start position:0% +the number operator matrix look like so +what do I put here yes + + align:start position:0% + + + + align:start position:0% + +but what's the lowest vibrational + + align:start position:0% +but what's the lowest vibrational + + + align:start position:0% +but what's the lowest vibrational +quantum number right okay and so you + + align:start position:0% +quantum number right okay and so you + + + align:start position:0% +quantum number right okay and so you +know once you've practiced a little bit + + align:start position:0% +know once you've practiced a little bit + + + align:start position:0% +know once you've practiced a little bit +you can write these things and it's it's + + align:start position:0% +you can write these things and it's it's + + + align:start position:0% +you can write these things and it's it's +not just an arbitrary thing because you + + align:start position:0% +not just an arbitrary thing because you + + + align:start position:0% +not just an arbitrary thing because you +want to be able to visualize what you're + + align:start position:0% +want to be able to visualize what you're + + + align:start position:0% +want to be able to visualize what you're +doing because you're dealing with + + align:start position:0% +doing because you're dealing with + + + align:start position:0% +doing because you're dealing with +multiple infinities of objects and you + + align:start position:0% +multiple infinities of objects and you + + + align:start position:0% +multiple infinities of objects and you +want to focus only on the ones you care + + align:start position:0% +want to focus only on the ones you care + + + align:start position:0% +want to focus only on the ones you care +about and you know with a little bit of + + align:start position:0% +about and you know with a little bit of + + + align:start position:0% +about and you know with a little bit of +guidance from these pictures you can do + + align:start position:0% +guidance from these pictures you can do + + + align:start position:0% +guidance from these pictures you can do +what you need to do okay so well we know + + align:start position:0% +what you need to do okay so well we know + + + align:start position:0% +what you need to do okay so well we know +what the operator cube is in terms of a + + align:start position:0% +what the operator cube is in terms of a + + + align:start position:0% +what the operator cube is in terms of a +dimensionless a version of QED and + + align:start position:0% +dimensionless a version of QED and + + + align:start position:0% +dimensionless a version of QED and +that's h-bar over now I'm going to be + + align:start position:0% +that's h-bar over now I'm going to be + + + align:start position:0% +that's h-bar over now I'm going to be +using this okay this is the + + align:start position:0% +using this okay this is the + + + align:start position:0% +using this okay this is the +dimensionless queue that's what the + + align:start position:0% +dimensionless queue that's what the + + + align:start position:0% +dimensionless queue that's what the +twiddle means and these are constants + + align:start position:0% +twiddle means and these are constants + + + align:start position:0% +twiddle means and these are constants +and now I'm using Omega twiddle because + + align:start position:0% +and now I'm using Omega twiddle because + + + align:start position:0% +and now I'm using Omega twiddle because +spectroscopy is always called Omega + + align:start position:0% +spectroscopy is always called Omega + + + align:start position:0% +spectroscopy is always called Omega +use Omega in wave number units + + align:start position:0% +use Omega in wave number units + + + align:start position:0% +use Omega in wave number units +reciprocal centimeter units which is a + + align:start position:0% +reciprocal centimeter units which is a + + + align:start position:0% +reciprocal centimeter units which is a +terrible thing because first of all wave + + align:start position:0% +terrible thing because first of all wave + + + align:start position:0% +terrible thing because first of all wave +number doesn't have a units of quantity + + align:start position:0% +number doesn't have a units of quantity + + + align:start position:0% +number doesn't have a units of quantity +and centimeters are things that we're + + align:start position:0% +and centimeters are things that we're + + + align:start position:0% +and centimeters are things that we're +not supposed to use because we use MKS + + align:start position:0% +not supposed to use because we use MKS + + + align:start position:0% +not supposed to use because we use MKS +but spectroscopy are stubborn and when + + align:start position:0% +but spectroscopy are stubborn and when + + + align:start position:0% +but spectroscopy are stubborn and when +we observe transitions we always talk + + align:start position:0% +we observe transitions we always talk + + + align:start position:0% +we observe transitions we always talk +about wave numbers not energy and so the + + align:start position:0% +about wave numbers not energy and so the + + + align:start position:0% +about wave numbers not energy and so the +difference between wave numbers and + + align:start position:0% +difference between wave numbers and + + + align:start position:0% +difference between wave numbers and +energies is the factor of h c not H bar + + align:start position:0% +energies is the factor of h c not H bar + + + align:start position:0% +energies is the factor of h c not H bar +C so anyway this is the conversion + + align:start position:0% +C so anyway this is the conversion + + + align:start position:0% +C so anyway this is the conversion +factor when Omega is in wave number + + align:start position:0% +factor when Omega is in wave number + + + align:start position:0% +factor when Omega is in wave number +units and so and we can go + + align:start position:0% +units and so and we can go + + + align:start position:0% +units and so and we can go +further and relate Q twiddle do let's + + align:start position:0% +further and relate Q twiddle do let's + + + align:start position:0% +further and relate Q twiddle do let's +just do that we can relate this to h-bar + + align:start position:0% +just do that we can relate this to h-bar + + + align:start position:0% +just do that we can relate this to h-bar +over 4 I see you Omega square what times + + align:start position:0% +over 4 I see you Omega square what times + + + align:start position:0% +over 4 I see you Omega square what times +a plus a dagger okay so this is + + align:start position:0% +a plus a dagger okay so this is + + + align:start position:0% +a plus a dagger okay so this is +something we did before + + align:start position:0% +something we did before + + + align:start position:0% +something we did before +Omega twiddle is K over nu Square 1 over + + align:start position:0% +Omega twiddle is K over nu Square 1 over + + + align:start position:0% +Omega twiddle is K over nu Square 1 over +2 pi C HC so this is this is what you're + + align:start position:0% +2 pi C HC so this is this is what you're + + + align:start position:0% +2 pi C HC so this is this is what you're +used to and this is the extra stuff that + + align:start position:0% +used to and this is the extra stuff that + + + align:start position:0% +used to and this is the extra stuff that +we have to carry along in order to work + + align:start position:0% +we have to carry along in order to work + + + align:start position:0% +we have to carry along in order to work +in wave number units + + align:start position:0% +in wave number units + + + align:start position:0% +in wave number units +okay so we have operators that can be + + align:start position:0% +okay so we have operators that can be + + + align:start position:0% +okay so we have operators that can be +expressed like a a a dagger a or a + + align:start position:0% +expressed like a a a dagger a or a + + + align:start position:0% +expressed like a a a dagger a or a +dagger a a a or anywhere you put the + + align:start position:0% +dagger a a a or anywhere you put the + + + align:start position:0% +dagger a a a or anywhere you put the +dagger anywhere you look at this and you + + align:start position:0% +dagger anywhere you look at this and you + + + align:start position:0% +dagger anywhere you look at this and you +say immediately I know two things I know + + align:start position:0% +say immediately I know two things I know + + + align:start position:0% +say immediately I know two things I know +the selection rule the selection rule is + + align:start position:0% +the selection rule the selection rule is + + + align:start position:0% +the selection rule the selection rule is +count up the A's and count up the a + + align:start position:0% +count up the A's and count up the a + + + align:start position:0% +count up the A's and count up the a +daggers and so this is Delta V of minus + + align:start position:0% +daggers and so this is Delta V of minus + + + align:start position:0% +daggers and so this is Delta V of minus +2 so is this all of the positions of the + + align:start position:0% +2 so is this all of the positions of the + + + align:start position:0% +2 so is this all of the positions of the +a dagger are Delta V of minus 2 but the + + align:start position:0% +a dagger are Delta V of minus 2 but the + + + align:start position:0% +a dagger are Delta V of minus 2 but the +numbers the matrix elements are + + align:start position:0% +numbers the matrix elements are + + + align:start position:0% +numbers the matrix elements are +different you know this from the last + + align:start position:0% +different you know this from the last + + + align:start position:0% +different you know this from the last +exam so + + align:start position:0% + + + + align:start position:0% + +can have v- to be and whatever comes in + + align:start position:0% +can have v- to be and whatever comes in + + + align:start position:0% +can have v- to be and whatever comes in +here well in one of those forms so those + + align:start position:0% +here well in one of those forms so those + + + align:start position:0% +here well in one of those forms so those +are the only nonzero elements and you + + align:start position:0% +are the only nonzero elements and you + + + align:start position:0% +are the only nonzero elements and you +know how to mechanically figure out what + + align:start position:0% +know how to mechanically figure out what + + + align:start position:0% +know how to mechanically figure out what +is the value of the matrix element and + + align:start position:0% +is the value of the matrix element and + + + align:start position:0% +is the value of the matrix element and +now in order to simplify the algebra + + align:start position:0% +now in order to simplify the algebra + + + align:start position:0% +now in order to simplify the algebra +which is not essential to the physics + + align:start position:0% +which is not essential to the physics + + + align:start position:0% +which is not essential to the physics +you want to take all of the terms that + + align:start position:0% +you want to take all of the terms that + + + align:start position:0% +you want to take all of the terms that +result safe from Q to the fourth and and + + align:start position:0% +result safe from Q to the fourth and and + + + align:start position:0% +result safe from Q to the fourth and and +arrange them according to selection rule + + align:start position:0% +arrange them according to selection rule + + + align:start position:0% +arrange them according to selection rule +and then take all of the terms that have + + align:start position:0% +and then take all of the terms that have + + + align:start position:0% +and then take all of the terms that have +the same selection rule and combining + + align:start position:0% +the same selection rule and combining + + + align:start position:0% +the same selection rule and combining +them to a single number so you know and + + align:start position:0% +them to a single number so you know and + + + align:start position:0% +them to a single number so you know and +you use the commutation rule to be able + + align:start position:0% +you use the commutation rule to be able + + + align:start position:0% +you use the commutation rule to be able +to reverse the order of terms well I + + align:start position:0% +to reverse the order of terms well I + + + align:start position:0% +to reverse the order of terms well I +don't want to do that I do so suppose we + + align:start position:0% +don't want to do that I do so suppose we + + + align:start position:0% +don't want to do that I do so suppose we +have an a a dagger and we can write that + + align:start position:0% +have an a a dagger and we can write that + + + align:start position:0% +have an a a dagger and we can write that +as a a dagger plus a dagger okay and so + + align:start position:0% +as a a dagger plus a dagger okay and so + + + align:start position:0% +as a a dagger plus a dagger okay and so +if we want to convert something like + + align:start position:0% +if we want to convert something like + + + align:start position:0% +if we want to convert something like +this just something like that we know + + align:start position:0% +this just something like that we know + + + align:start position:0% +this just something like that we know +that this has a value of +1 so we can do + + align:start position:0% +that this has a value of +1 so we can do + + + align:start position:0% +that this has a value of +1 so we can do +that and that's tedious and you have to + + align:start position:0% +that and that's tedious and you have to + + + align:start position:0% +that and that's tedious and you have to +do it but one of the things that is kind + + align:start position:0% +do it but one of the things that is kind + + + align:start position:0% +do it but one of the things that is kind +of nice is when you have a problem + + align:start position:0% +of nice is when you have a problem + + + align:start position:0% +of nice is when you have a problem +that's cubic or quartic or quintic you + + align:start position:0% +that's cubic or quartic or quintic you + + + align:start position:0% +that's cubic or quartic or quintic you +do mess around with this operator l true + + align:start position:0% +do mess around with this operator l true + + + align:start position:0% +do mess around with this operator l true +once in your life and you put it on a + + align:start position:0% +once in your life and you put it on a + + + align:start position:0% +once in your life and you put it on a +sheet of paper and you refer to it it + + align:start position:0% +sheet of paper and you refer to it it + + + align:start position:0% +sheet of paper and you refer to it it +doesn't matter what the molecule is what + + align:start position:0% +doesn't matter what the molecule is what + + + align:start position:0% +doesn't matter what the molecule is what +the constant in front of Q to the third + + align:start position:0% +the constant in front of Q to the third + + + align:start position:0% +the constant in front of Q to the third +or fourth or 13th is if you've done the + + align:start position:0% +or fourth or 13th is if you've done the + + + align:start position:0% +or fourth or 13th is if you've done the +operator algebra you're fine now you + + align:start position:0% +operator algebra you're fine now you + + + align:start position:0% +operator algebra you're fine now you +might say well I don't want to do that + + align:start position:0% +might say well I don't want to do that + + + align:start position:0% +might say well I don't want to do that +I'm going to have the computer do that + + align:start position:0% +I'm going to have the computer do that + + + align:start position:0% +I'm going to have the computer do that +well fine you can have the computer do + + align:start position:0% +well fine you can have the computer do + + + align:start position:0% +well fine you can have the computer do +that and then a computer will tell you + + align:start position:0% +that and then a computer will tell you + + + align:start position:0% +that and then a computer will tell you +what the matrix looks like and + + align:start position:0% +what the matrix looks like and + + + align:start position:0% +what the matrix looks like and +you can do what you need to do okay so + + align:start position:0% +you can do what you need to do okay so + + + align:start position:0% +you can do what you need to do okay so +spectroscopy called the vibrational + + align:start position:0% +spectroscopy called the vibrational + + + align:start position:0% +spectroscopy called the vibrational +energy formula G of B I don't know why + + align:start position:0% +energy formula G of B I don't know why + + + align:start position:0% +energy formula G of B I don't know why +the letter G is always used but it is + + align:start position:0% +the letter G is always used but it is + + + align:start position:0% +the letter G is always used but it is +and so this is the same thing as + + align:start position:0% +and so this is the same thing as + + + align:start position:0% +and so this is the same thing as +vibrational energy and the vibrational + + align:start position:0% +vibrational energy and the vibrational + + + align:start position:0% +vibrational energy and the vibrational +energy I'm gonna put the tilt on it you + + align:start position:0% +energy I'm gonna put the tilt on it you + + + align:start position:0% +energy I'm gonna put the tilt on it you +will never find a tilde in any + + align:start position:0% +will never find a tilde in any + + + align:start position:0% +will never find a tilde in any +spectroscopy no paper we assume that you + + align:start position:0% +spectroscopy no paper we assume that you + + + align:start position:0% +spectroscopy no paper we assume that you +understand that the only units for + + align:start position:0% +understand that the only units for + + + align:start position:0% +understand that the only units for +spectroscopic quantities are reciprocal + + align:start position:0% +spectroscopic quantities are reciprocal + + + align:start position:0% +spectroscopic quantities are reciprocal +centimeters but for this purpose is I + + align:start position:0% +centimeters but for this purpose is I + + + align:start position:0% +centimeters but for this purpose is I +have I've finally caved and I said okay + + align:start position:0% +have I've finally caved and I said okay + + + align:start position:0% +have I've finally caved and I said okay +I'm gonna put the Tilda's on so the + + align:start position:0% +I'm gonna put the Tilda's on so the + + + align:start position:0% +I'm gonna put the Tilda's on so the +energy levels now you might ask why this + + align:start position:0% +energy levels now you might ask why this + + + align:start position:0% +energy levels now you might ask why this +this is the first n-terminus T constant + + align:start position:0% +this is the first n-terminus T constant + + + align:start position:0% +this is the first n-terminus T constant +it's not a product of two numbers it's + + align:start position:0% +it's not a product of two numbers it's + + + align:start position:0% +it's not a product of two numbers it's +just what people wrote originally + + align:start position:0% +just what people wrote originally + + + align:start position:0% +just what people wrote originally +because they sort of thought of it as a + + align:start position:0% +because they sort of thought of it as a + + + align:start position:0% +because they sort of thought of it as a +product of two numbers but it's really + + align:start position:0% +product of two numbers but it's really + + + align:start position:0% +product of two numbers but it's really +only one and and that's times V plus 1/2 + + align:start position:0% +only one and and that's times V plus 1/2 + + + align:start position:0% +only one and and that's times V plus 1/2 +squared and then the next term is omega + + align:start position:0% +squared and then the next term is omega + + + align:start position:0% +squared and then the next term is omega +e ye b plus 1/2 cubed so this is a dumb + + align:start position:0% +e ye b plus 1/2 cubed so this is a dumb + + + align:start position:0% +e ye b plus 1/2 cubed so this is a dumb +power series in the vibrational quantum + + align:start position:0% +power series in the vibrational quantum + + + align:start position:0% +power series in the vibrational quantum +number and so in the spectrum one is + + align:start position:0% +number and so in the spectrum one is + + + align:start position:0% +number and so in the spectrum one is +able to fit the spectrum to these sorts + + align:start position:0% +able to fit the spectrum to these sorts + + + align:start position:0% +able to fit the spectrum to these sorts +of things so that's what you get + + align:start position:0% +of things so that's what you get + + + align:start position:0% +of things so that's what you get +experimentally but what you want to know + + align:start position:0% +experimentally but what you want to know + + + align:start position:0% +experimentally but what you want to know +is we want to know the force the force + + align:start position:0% +is we want to know the force the force + + + align:start position:0% +is we want to know the force the force +constant the reduced mass the cube again + + align:start position:0% +constant the reduced mass the cube again + + + align:start position:0% +constant the reduced mass the cube again +our ministry constant the court again + + align:start position:0% +our ministry constant the court again + + + align:start position:0% +our ministry constant the court again +i'm gonna see constant and whatever so + + align:start position:0% +i'm gonna see constant and whatever so + + + align:start position:0% +i'm gonna see constant and whatever so +these are structural parameters and + + align:start position:0% +these are structural parameters and + + + align:start position:0% +these are structural parameters and +these are molecular parameters or not + + align:start position:0% +these are molecular parameters or not + + + align:start position:0% +these are molecular parameters or not +people like to call them spectroscopic + + align:start position:0% +people like to call them spectroscopic + + + align:start position:0% +people like to call them spectroscopic +parameters but that implies something + + align:start position:0% +parameters but that implies something + + + align:start position:0% +parameters but that implies something +more fundamental these are just what you + + align:start position:0% +more fundamental these are just what you + + + align:start position:0% +more fundamental these are just what you +measure in the spectrum and so we want + + align:start position:0% +measure in the spectrum and so we want + + + align:start position:0% +measure in the spectrum and so we want +to know the relationship between the + + align:start position:0% +to know the relationship between the + + + align:start position:0% +to know the relationship between the +things we measure and the things we want + + align:start position:0% +things we measure and the things we want + + + align:start position:0% +things we measure and the things we want +to know and so that's what perturbation + + align:start position:0% +to know and so that's what perturbation + + + align:start position:0% +to know and so that's what perturbation +theory is for okay + + align:start position:0% +theory is for okay + + + align:start position:0% +theory is for okay +now to risk boring you I'm just going to + + align:start position:0% +now to risk boring you I'm just going to + + + align:start position:0% +now to risk boring you I'm just going to +go over material that we've done before + + align:start position:0% +go over material that we've done before + + + align:start position:0% +go over material that we've done before +so if we have Q to the N we have this + + align:start position:0% +so if we have Q to the N we have this + + + align:start position:0% +so if we have Q to the N we have this +constant out in front h-bar over 4 pi C + + align:start position:0% +constant out in front h-bar over 4 pi C + + + align:start position:0% +constant out in front h-bar over 4 pi C +mu Omega to the N over 2 a plus a dagger + + align:start position:0% +mu Omega to the N over 2 a plus a dagger + + + align:start position:0% +mu Omega to the N over 2 a plus a dagger +to the N and so we're going to be + + align:start position:0% +to the N and so we're going to be + + + align:start position:0% +to the N and so we're going to be +constantly dealing with earth like a + + align:start position:0% +constantly dealing with earth like a + + + align:start position:0% +constantly dealing with earth like a +plus a dagger squared and a plus a + + align:start position:0% +plus a dagger squared and a plus a + + + align:start position:0% +plus a dagger squared and a plus a +dagger cubed and so on these are the + + align:start position:0% +dagger cubed and so on these are the + + + align:start position:0% +dagger cubed and so on these are the +things I said you're going to work out + + align:start position:0% +things I said you're going to work out + + + align:start position:0% +things I said you're going to work out +once in your life and either remember or + + align:start position:0% +once in your life and either remember or + + + align:start position:0% +once in your life and either remember or +just be so come so practiced with it + + align:start position:0% +just be so come so practiced with it + + + align:start position:0% +just be so come so practiced with it +you'll do it faster okay and so these + + align:start position:0% +you'll do it faster okay and so these + + + align:start position:0% +you'll do it faster okay and so these +contain the values of the matrix + + align:start position:0% +contain the values of the matrix + + + align:start position:0% +contain the values of the matrix +elements and the selection rules okay + + align:start position:0% +elements and the selection rules okay + + + align:start position:0% +elements and the selection rules okay +so I'm going to do an example the cube + + align:start position:0% +so I'm going to do an example the cube + + + align:start position:0% +so I'm going to do an example the cube +and that's of course this thing in + + align:start position:0% +and that's of course this thing in + + + align:start position:0% +and that's of course this thing in +constant to the three-halves and then a + + align:start position:0% +constant to the three-halves and then a + + + align:start position:0% +constant to the three-halves and then a +cubed plus a dagger cubed plus a whole + + align:start position:0% +cubed plus a dagger cubed plus a whole + + + align:start position:0% +cubed plus a dagger cubed plus a whole +bunch of terms which have two A's in one + + align:start position:0% +bunch of terms which have two A's in one + + + align:start position:0% +bunch of terms which have two A's in one +a dagger so let's just put a squared + a + + align:start position:0% +a dagger so let's just put a squared + a + + + align:start position:0% +a dagger so let's just put a squared + a +dagger this isn't a commutation rule + + align:start position:0% +dagger this isn't a commutation rule + + + align:start position:0% +dagger this isn't a commutation rule +this is just three terms that you have + + align:start position:0% +this is just three terms that you have + + + align:start position:0% +this is just three terms that you have +to deal with and three terms that have a + + align:start position:0% +to deal with and three terms that have a + + + align:start position:0% +to deal with and three terms that have a +dagger squared and a and then + + align:start position:0% +dagger squared and a and then + + + align:start position:0% +dagger squared and a and then +so that's what you'd do your work on + + align:start position:0% +so that's what you'd do your work on + + + align:start position:0% +so that's what you'd do your work on +because you don't want to be messing + + align:start position:0% +because you don't want to be messing + + + align:start position:0% +because you don't want to be messing +around once you start doing this + + align:start position:0% +around once you start doing this + + + align:start position:0% +around once you start doing this +perturbation sums because it's ugly + + align:start position:0% +perturbation sums because it's ugly + + + align:start position:0% +perturbation sums because it's ugly +enough so you want to simplify this as + + align:start position:0% +enough so you want to simplify this as + + + align:start position:0% +enough so you want to simplify this as +much as possible and you do and so the + + align:start position:0% +much as possible and you do and so the + + + align:start position:0% +much as possible and you do and so the +purpose is this is Delta V of minus + + align:start position:0% +purpose is this is Delta V of minus + + + align:start position:0% +purpose is this is Delta V of minus +three this is Delta V of plus three this + + align:start position:0% +three this is Delta V of plus three this + + + align:start position:0% +three this is Delta V of plus three this +is Delta V of minus 1 this is Delta V of + + align:start position:0% +is Delta V of minus 1 this is Delta V of + + + align:start position:0% +is Delta V of minus 1 this is Delta V of +plus 1 you arrange the terms according + + align:start position:0% +plus 1 you arrange the terms according + + + align:start position:0% +plus 1 you arrange the terms according +to selection rules and so what you end + + align:start position:0% +to selection rules and so what you end + + + align:start position:0% +to selection rules and so what you end +up getting is Q cubed is equal to this + + align:start position:0% +up getting is Q cubed is equal to this + + + align:start position:0% +up getting is Q cubed is equal to this +thing to the three-halves times a cubed + + align:start position:0% +thing to the three-halves times a cubed + + + align:start position:0% +thing to the three-halves times a cubed +plus three a n plus three a dagger n + + align:start position:0% +plus three a n plus three a dagger n + + + align:start position:0% +plus three a n plus three a dagger n +plus one plus okay the algebra is + + align:start position:0% +plus one plus okay the algebra is + + + align:start position:0% +plus one plus okay the algebra is +tedious pretty simple and what you + + align:start position:0% +tedious pretty simple and what you + + + align:start position:0% +tedious pretty simple and what you +usually want to do is have the thing + + align:start position:0% +usually want to do is have the thing + + + align:start position:0% +usually want to do is have the thing +that changes the vibrational quantum + + align:start position:0% +that changes the vibrational quantum + + + align:start position:0% +that changes the vibrational quantum +number after the thing that preserves it + + align:start position:0% +number after the thing that preserves it + + + align:start position:0% +number after the thing that preserves it +because then it's easy just to write + + align:start position:0% +because then it's easy just to write + + + align:start position:0% +because then it's easy just to write +down these matrix elements just by + + align:start position:0% +down these matrix elements just by + + + align:start position:0% +down these matrix elements just by +inspection okay you could do it the + + align:start position:0% +inspection okay you could do it the + + + align:start position:0% +inspection okay you could do it the +other way around it's more complicated + + align:start position:0% +other way around it's more complicated + + + align:start position:0% +other way around it's more complicated +if you put the N first and then the a + + align:start position:0% +if you put the N first and then the a + + + align:start position:0% +if you put the N first and then the a +but it's not you know it's up to you so + + align:start position:0% +but it's not you know it's up to you so + + + align:start position:0% +but it's not you know it's up to you so +these then are what you work on and now + + align:start position:0% +these then are what you work on and now + + + align:start position:0% +these then are what you work on and now +we start doing non-degenerate + + align:start position:0% +we start doing non-degenerate + + + align:start position:0% +we start doing non-degenerate +perturbation Theory the first thing you + + align:start position:0% +perturbation Theory the first thing you + + + align:start position:0% +perturbation Theory the first thing you +do is you want to know well what is the + + align:start position:0% +do is you want to know well what is the + + + align:start position:0% +do is you want to know well what is the +first order correction to the energy and + + align:start position:0% +first order correction to the energy and + + + align:start position:0% +first order correction to the energy and +if this is Q Q to the third power + + align:start position:0% +if this is Q Q to the third power + + + align:start position:0% +if this is Q Q to the third power +then this that's zero so you like zeros + + align:start position:0% +then this that's zero so you like zeros + + + align:start position:0% +then this that's zero so you like zeros +but in this case you're kind of + + align:start position:0% +but in this case you're kind of + + + align:start position:0% +but in this case you're kind of +disappointed because you don't know what + + align:start position:0% +disappointed because you don't know what + + + align:start position:0% +disappointed because you don't know what +the sign of the coefficient of Q to the + + align:start position:0% +the sign of the coefficient of Q to the + + + align:start position:0% +the sign of the coefficient of Q to the +third power is + + align:start position:0% +third power is + + + align:start position:0% +third power is +from any experiment or at least any + + align:start position:0% +from any experiment or at least any + + + align:start position:0% +from any experiment or at least any +experiment at the level we've described + + align:start position:0% +experiment at the level we've described + + + align:start position:0% +experiment at the level we've described +when we introduced rotation as well as + + align:start position:0% +when we introduced rotation as well as + + + align:start position:0% +when we introduced rotation as well as +vibration there will be something that + + align:start position:0% +vibration there will be something that + + + align:start position:0% +vibration there will be something that +reports the sign of the coefficient of Q + + align:start position:0% +reports the sign of the coefficient of Q + + + align:start position:0% +reports the sign of the coefficient of Q +third so now we're we're stuck and we + + align:start position:0% +third so now we're we're stuck and we + + + align:start position:0% +third so now we're we're stuck and we +have to start doing all of this + + align:start position:0% +have to start doing all of this + + + align:start position:0% +have to start doing all of this +second-order stuff and okay well we have + + align:start position:0% +second-order stuff and okay well we have + + + align:start position:0% +second-order stuff and okay well we have +this V Q to the third power and so we + + align:start position:0% +this V Q to the third power and so we + + + align:start position:0% +this V Q to the third power and so we +get squares of the matrix elements so we + + align:start position:0% +get squares of the matrix elements so we + + + align:start position:0% +get squares of the matrix elements so we +get a B squared we get this thing to the + + align:start position:0% +get a B squared we get this thing to the + + + align:start position:0% +get a B squared we get this thing to the +third power because we're squaring the + + align:start position:0% +third power because we're squaring the + + + align:start position:0% +third power because we're squaring the +matrix M so this bunch of constants and + + align:start position:0% +matrix M so this bunch of constants and + + + align:start position:0% +matrix M so this bunch of constants and +then you get a matrix element V prime + + align:start position:0% +then you get a matrix element V prime + + + align:start position:0% +then you get a matrix element V prime +some operator B and then we get an + + align:start position:0% +some operator B and then we get an + + + align:start position:0% +some operator B and then we get an +energy denominator now we you know + + align:start position:0% +energy denominator now we you know + + + align:start position:0% +energy denominator now we you know +there's a lot of symbols but we want to + + align:start position:0% +there's a lot of symbols but we want to + + + align:start position:0% +there's a lot of symbols but we want to +simplify things as much as possible H C + + align:start position:0% +simplify things as much as possible H C + + + align:start position:0% +simplify things as much as possible H C +Omega times the minus V prime so this is + + align:start position:0% +Omega times the minus V prime so this is + + + align:start position:0% +Omega times the minus V prime so this is +matrix element squared over an energy + + align:start position:0% +matrix element squared over an energy + + + align:start position:0% +matrix element squared over an energy +denominator and what you really want to + + align:start position:0% +denominator and what you really want to + + + align:start position:0% +denominator and what you really want to +know is what is the quantum number + + align:start position:0% +know is what is the quantum number + + + align:start position:0% +know is what is the quantum number +dependence of everything okay so the + + align:start position:0% +dependence of everything okay so the + + + align:start position:0% +dependence of everything okay so the +operator here is either Q dagger cubed Q + + align:start position:0% +operator here is either Q dagger cubed Q + + + align:start position:0% +operator here is either Q dagger cubed Q +dagger I'm sorry a dagger a cubed a + + align:start position:0% +dagger I'm sorry a dagger a cubed a + + + align:start position:0% +dagger I'm sorry a dagger a cubed a +times n a dagger n plus 1 or a dagger + + align:start position:0% +times n a dagger n plus 1 or a dagger + + + align:start position:0% +times n a dagger n plus 1 or a dagger +cubed and so we we know how to write all + + align:start position:0% +cubed and so we we know how to write all + + + align:start position:0% +cubed and so we we know how to write all +of these matrix elements trivially no + + align:start position:0% +of these matrix elements trivially no + + + align:start position:0% +of these matrix elements trivially no +work once we've simplified here it's + + align:start position:0% +work once we've simplified here it's + + + align:start position:0% +work once we've simplified here it's +really trivial to write the + + align:start position:0% + + + + align:start position:0% + +the squared matrix of it okay so we do + + align:start position:0% +the squared matrix of it okay so we do + + + align:start position:0% +the squared matrix of it okay so we do +it + + align:start position:0% + + + + align:start position:0% + +and so we arrange things according to + + align:start position:0% +and so we arrange things according to + + + align:start position:0% +and so we arrange things according to +Delta V and we have Delta V a plus 3 + + align:start position:0% +Delta V and we have Delta V a plus 3 + + + align:start position:0% +Delta V and we have Delta V a plus 3 +plus 1 minus 1 and minus 3 and so what + + align:start position:0% +plus 1 minus 1 and minus 3 and so what + + + align:start position:0% +plus 1 minus 1 and minus 3 and so what +we get from the square of the matrix + + align:start position:0% +we get from the square of the matrix + + + align:start position:0% +we get from the square of the matrix +element a dagger cubed we get V Plus 1 B + + align:start position:0% +element a dagger cubed we get V Plus 1 B + + + align:start position:0% +element a dagger cubed we get V Plus 1 B +plus 2 V Plus 3 and we also have an + + align:start position:0% +plus 2 V Plus 3 and we also have an + + + align:start position:0% +plus 2 V Plus 3 and we also have an +energy denominator and we're going to + + align:start position:0% +energy denominator and we're going to + + + align:start position:0% +energy denominator and we're going to +get for this one 1 over minus 3 because + + align:start position:0% +get for this one 1 over minus 3 because + + + align:start position:0% +get for this one 1 over minus 3 because +the initial quantum number is is V and + + align:start position:0% +the initial quantum number is is V and + + + align:start position:0% +the initial quantum number is is V and +the second quantum number V prime is V + + align:start position:0% +the second quantum number V prime is V + + + align:start position:0% +the second quantum number V prime is V +Plus 3 and so we get a minus 3 in the + + align:start position:0% +Plus 3 and so we get a minus 3 in the + + + align:start position:0% +Plus 3 and so we get a minus 3 in the +energy denominator and then the plus 1 + + align:start position:0% +energy denominator and then the plus 1 + + + align:start position:0% +energy denominator and then the plus 1 +that comes out to be I've got it in a + + align:start position:0% +that comes out to be I've got it in a + + + align:start position:0% +that comes out to be I've got it in a +different order in my notes that comes + + align:start position:0% +different order in my notes that comes + + + align:start position:0% +different order in my notes that comes +out to be 9 v + 1 v + 2 v + 1 squared + + align:start position:0% +out to be 9 v + 1 v + 2 v + 1 squared + + + align:start position:0% +out to be 9 v + 1 v + 2 v + 1 squared +and the energy denominator for this is 1 + + align:start position:0% +and the energy denominator for this is 1 + + + align:start position:0% +and the energy denominator for this is 1 +over minus 1 ok then we have the I'm + + align:start position:0% +over minus 1 ok then we have the I'm + + + align:start position:0% +over minus 1 ok then we have the I'm +going to skip this one we have the + + align:start position:0% +going to skip this one we have the + + + align:start position:0% +going to skip this one we have the +matrix element here and that's going to + + align:start position:0% +matrix element here and that's going to + + + align:start position:0% +matrix element here and that's going to +be V V minus 1 n minus 2 + + align:start position:0% +be V V minus 1 n minus 2 + + + align:start position:0% +be V V minus 1 n minus 2 +remember we're squaring these things so + + align:start position:0% +remember we're squaring these things so + + + align:start position:0% +remember we're squaring these things so +that's why we don't have those square + + align:start position:0% +that's why we don't have those square + + + align:start position:0% +that's why we don't have those square +roots anymore and we have an energy + + align:start position:0% +roots anymore and we have an energy + + + align:start position:0% +roots anymore and we have an energy +denominator 1 over 3 okay now advice you + + align:start position:0% +denominator 1 over 3 okay now advice you + + + align:start position:0% +denominator 1 over 3 okay now advice you +don't like this and you want to minimize + + align:start position:0% +don't like this and you want to minimize + + + align:start position:0% +don't like this and you want to minimize +your effort + + align:start position:0% +your effort + + + align:start position:0% +your effort +and so it turns out that if you take the + + align:start position:0% +and so it turns out that if you take the + + + align:start position:0% +and so it turns out that if you take the +terms with the equal and opposite energy + + align:start position:0% +terms with the equal and opposite energy + + + align:start position:0% +terms with the equal and opposite energy +denominators and combine them + + align:start position:0% +denominators and combine them + + + align:start position:0% +denominators and combine them +simplifications occur one of the things + + align:start position:0% +simplifications occur one of the things + + + align:start position:0% +simplifications occur one of the things +you can see is you're going to have a V + + align:start position:0% +you can see is you're going to have a V + + + align:start position:0% +you can see is you're going to have a V +cubed here and you're going to have a V + + align:start position:0% +cubed here and you're going to have a V + + + align:start position:0% +cubed here and you're going to have a V +cubed here they're going to cancel right + + align:start position:0% +cubed here they're going to cancel right + + + align:start position:0% +cubed here they're going to cancel right +because we have them 1 over minus 3 and + + align:start position:0% +because we have them 1 over minus 3 and + + + align:start position:0% +because we have them 1 over minus 3 and +then 1 over plus 3 so you get an + + align:start position:0% +then 1 over plus 3 so you get an + + + align:start position:0% +then 1 over plus 3 so you get an +algebraic simplification when you take + + align:start position:0% +algebraic simplification when you take + + + align:start position:0% +algebraic simplification when you take +these terms pairwise and combine them + + align:start position:0% +these terms pairwise and combine them + + + align:start position:0% +these terms pairwise and combine them +now you're never in your life gonna do + + align:start position:0% +now you're never in your life gonna do + + + align:start position:0% +now you're never in your life gonna do +this but you know if you didn't do it + + align:start position:0% +this but you know if you didn't do it + + + align:start position:0% +this but you know if you didn't do it +you know this is how you end up with + + align:start position:0% +you know this is how you end up with + + + align:start position:0% +you know this is how you end up with +algebra which or formulas which are + + align:start position:0% +algebra which or formulas which are + + + align:start position:0% +algebra which or formulas which are +simple they're horrible getting there + + align:start position:0% +simple they're horrible getting there + + + align:start position:0% +simple they're horrible getting there +unless you know how to get there so now + + align:start position:0% +unless you know how to get there so now + + + align:start position:0% +unless you know how to get there so now +there's a rule so if the perturbation is + + align:start position:0% +there's a rule so if the perturbation is + + + align:start position:0% +there's a rule so if the perturbation is +2 to the N then the highest order term + + align:start position:0% + + + + align:start position:0% + +involves V plus 1/2 to the N minus 1 the + + align:start position:0% +involves V plus 1/2 to the N minus 1 the + + + align:start position:0% +involves V plus 1/2 to the N minus 1 the +reason for that is in the matrix of them + + align:start position:0% +reason for that is in the matrix of them + + + align:start position:0% +reason for that is in the matrix of them +it the highest order term is V is V plus + + align:start position:0% +it the highest order term is V is V plus + + + align:start position:0% +it the highest order term is V is V plus +1/2 to V + 3 over 2 and then you square + + align:start position:0% +1/2 to V + 3 over 2 and then you square + + + align:start position:0% +1/2 to V + 3 over 2 and then you square +it you get to the third power and then + + align:start position:0% +it you get to the third power and then + + + align:start position:0% +it you get to the third power and then +the highest order term cancels so we + + align:start position:0% +the highest order term cancels so we + + + align:start position:0% +the highest order term cancels so we +know that if we have if we're dealing + + align:start position:0% +know that if we have if we're dealing + + + align:start position:0% +know that if we have if we're dealing +with Q to the third power + + align:start position:0% +with Q to the third power + + + align:start position:0% +with Q to the third power +we're going to get a term V plus 1/2 + + align:start position:0% +we're going to get a term V plus 1/2 + + + align:start position:0% +we're going to get a term V plus 1/2 +squared if we're dealing with Q to the + + align:start position:0% +squared if we're dealing with Q to the + + + align:start position:0% +squared if we're dealing with Q to the +fourth power well then we get something + + align:start position:0% +fourth power well then we get something + + + align:start position:0% +fourth power well then we get something +from 2nd order from the first order + + align:start position:0% +from 2nd order from the first order + + + align:start position:0% +from 2nd order from the first order +correction to the energy a Delta V of 1 + + align:start position:0% +correction to the energy a Delta V of 1 + + + align:start position:0% +correction to the energy a Delta V of 1 +matrix element where we done is square + + align:start position:0% +matrix element where we done is square + + + align:start position:0% +matrix element where we done is square +it + + align:start position:0% +it + + + align:start position:0% +it +and we get 3 plus 1/2 squared also okay + + align:start position:0% +and we get 3 plus 1/2 squared also okay + + + align:start position:0% +and we get 3 plus 1/2 squared also okay +and the the off-diagonal matrix element + + align:start position:0% +and the the off-diagonal matrix element + + + align:start position:0% +and the the off-diagonal matrix element +we're going to get a from the the + + align:start position:0% +we're going to get a from the the + + + align:start position:0% +we're going to get a from the the +highest order from the off diagonal is V + + align:start position:0% +highest order from the off diagonal is V + + + align:start position:0% +highest order from the off diagonal is V +plus 1/2 cubed so one of the things that + + align:start position:0% +plus 1/2 cubed so one of the things that + + + align:start position:0% +plus 1/2 cubed so one of the things that +is great about the algebra is with a + + align:start position:0% +is great about the algebra is with a + + + align:start position:0% +is great about the algebra is with a +little bit of practice you know how to + + align:start position:0% +little bit of practice you know how to + + + align:start position:0% +little bit of practice you know how to +organize things and if you do the + + align:start position:0% +organize things and if you do the + + + align:start position:0% +organize things and if you do the +algebra you connect you you collect the + + align:start position:0% +algebra you connect you you collect the + + + align:start position:0% +algebra you connect you you collect the +highest order terms then there's that + + align:start position:0% +highest order terms then there's that + + + align:start position:0% +highest order terms then there's that +kind of cascading result and you get the + + align:start position:0% +kind of cascading result and you get the + + + align:start position:0% +kind of cascading result and you get the +lower lowest order terms in simplified + + align:start position:0% +lower lowest order terms in simplified + + + align:start position:0% +lower lowest order terms in simplified +form so this is this is irrelevant but + + align:start position:0% +form so this is this is irrelevant but + + + align:start position:0% +form so this is this is irrelevant but +this is how you do it if you're a + + align:start position:0% +this is how you do it if you're a + + + align:start position:0% +this is how you do it if you're a +professional + + align:start position:0% +professional + + + align:start position:0% +professional +so with these results we can determine + + align:start position:0% +so with these results we can determine + + + align:start position:0% +so with these results we can determine +the relationship between these molecular + + align:start position:0% +the relationship between these molecular + + + align:start position:0% +the relationship between these molecular +constants where did I put them + + align:start position:0% +constants where did I put them + + + align:start position:0% +constants where did I put them +well probably on this board know + + align:start position:0% +well probably on this board know + + + align:start position:0% +well probably on this board know +so we oh yeah it's right here so we have + + align:start position:0% +so we oh yeah it's right here so we have + + + align:start position:0% +so we oh yeah it's right here so we have +Omega e make the XE Omega Y E and we + + align:start position:0% +Omega e make the XE Omega Y E and we + + + align:start position:0% +Omega e make the XE Omega Y E and we +have then the relationships between + + align:start position:0% +have then the relationships between + + + align:start position:0% +have then the relationships between +these things which you measure and these + + align:start position:0% +these things which you measure and these + + + align:start position:0% +these things which you measure and these +things that you want to know so the + + align:start position:0% +things that you want to know so the + + + align:start position:0% +things that you want to know so the +stuff you want to know is encoded in the + + align:start position:0% +stuff you want to know is encoded in the + + + align:start position:0% +stuff you want to know is encoded in the +spectrum in a not particularly + + align:start position:0% +spectrum in a not particularly + + + align:start position:0% +spectrum in a not particularly +complicated way it's just not a very + + align:start position:0% +complicated way it's just not a very + + + align:start position:0% +complicated way it's just not a very +interesting way but you have to do it in + + align:start position:0% +interesting way but you have to do it in + + + align:start position:0% +interesting way but you have to do it in +order to get it okay so I've got just a + + align:start position:0% +order to get it okay so I've got just a + + + align:start position:0% +order to get it okay so I've got just a +few minutes left but I want to get to + + align:start position:0% +few minutes left but I want to get to + + + align:start position:0% +few minutes left but I want to get to +the really interesting stuff so + + align:start position:0% + + + + align:start position:0% + +if you have some expression for the + + align:start position:0% +if you have some expression for the + + + align:start position:0% +if you have some expression for the +potential it's easy to go and get the + + align:start position:0% +potential it's easy to go and get the + + + align:start position:0% +potential it's easy to go and get the +expression for the energy levels and the + + align:start position:0% +expression for the energy levels and the + + + align:start position:0% +expression for the energy levels and the +wave functions and you can use the + + align:start position:0% +wave functions and you can use the + + + align:start position:0% +wave functions and you can use the +vector picture or the wave function + + align:start position:0% +vector picture or the wave function + + + align:start position:0% +vector picture or the wave function +picture it doesn't matter and so this is + + align:start position:0% +picture it doesn't matter and so this is + + + align:start position:0% +picture it doesn't matter and so this is +enough to do the spectroscopy it tells + + align:start position:0% +enough to do the spectroscopy it tells + + + align:start position:0% +enough to do the spectroscopy it tells +you not only where are the energies but + + align:start position:0% +you not only where are the energies but + + + align:start position:0% +you not only where are the energies but +because some transition are supposed to + + align:start position:0% +because some transition are supposed to + + + align:start position:0% +because some transition are supposed to +be weak because of the dipole selection + + align:start position:0% +be weak because of the dipole selection + + + align:start position:0% +be weak because of the dipole selection +rule or whatever it's as well there's + + align:start position:0% +rule or whatever it's as well there's + + + align:start position:0% +rule or whatever it's as well there's +some transitions that have borrowed + + align:start position:0% +some transitions that have borrowed + + + align:start position:0% +some transitions that have borrowed +intensity it also tells you suppose we + + align:start position:0% +intensity it also tells you suppose we + + + align:start position:0% +intensity it also tells you suppose we +make a coherent superposition state at T + + align:start position:0% +make a coherent superposition state at T + + + align:start position:0% +make a coherent superposition state at T +equals zero using a short pulse and + + align:start position:0% +equals zero using a short pulse and + + + align:start position:0% +equals zero using a short pulse and +suppose in the company in the linear + + align:start position:0% +suppose in the company in the linear + + + align:start position:0% +suppose in the company in the linear +combination of zero order states there's + + align:start position:0% +combination of zero order states there's + + + align:start position:0% +combination of zero order states there's +only one that is bright and so then it + + align:start position:0% +only one that is bright and so then it + + + align:start position:0% +only one that is bright and so then it +tells us if we know how to go from + + align:start position:0% +tells us if we know how to go from + + + align:start position:0% +tells us if we know how to go from +eigenstate from basis States to + + align:start position:0% +eigenstate from basis States to + + + align:start position:0% +eigenstate from basis States to +eigenstates we can go backwards and we + + align:start position:0% +eigenstates we can go backwards and we + + + align:start position:0% +eigenstates we can go backwards and we +can write with the expression for T + + align:start position:0% +can write with the expression for T + + + align:start position:0% +can write with the expression for T +equals the T equals zero superposition + + align:start position:0% +equals the T equals zero superposition + + + align:start position:0% +equals the T equals zero superposition +in terms of some sum over side V zero CV + + align:start position:0% + + + + align:start position:0% + +and if we have this as long as we are + + align:start position:0% +and if we have this as long as we are + + + align:start position:0% +and if we have this as long as we are +writing a superposition in terms of + + align:start position:0% +writing a superposition in terms of + + + align:start position:0% +writing a superposition in terms of +eigenstates we know immediately how to + + align:start position:0% +eigenstates we know immediately how to + + + align:start position:0% +eigenstates we know immediately how to +get this and then we've got all the + + align:start position:0% +get this and then we've got all the + + + align:start position:0% +get this and then we've got all the +dynamics so the perturbation Theory + + align:start position:0% +dynamics so the perturbation Theory + + + align:start position:0% +dynamics so the perturbation Theory +enables you to say if I want to work in + + align:start position:0% +enables you to say if I want to work in + + + align:start position:0% +enables you to say if I want to work in +the time domain I know what what to do + + align:start position:0% +the time domain I know what what to do + + + align:start position:0% +the time domain I know what what to do +and I know that certain you're going to + + align:start position:0% +and I know that certain you're going to + + + align:start position:0% +and I know that certain you're going to +get in the time domain you're going to + + align:start position:0% +get in the time domain you're going to + + + align:start position:0% +get in the time domain you're going to +get a signal that oscillates + + align:start position:0% +get a signal that oscillates + + + align:start position:0% +get a signal that oscillates +and it oscillates at frequencies + + align:start position:0% +and it oscillates at frequencies + + + align:start position:0% +and it oscillates at frequencies +corresponding to energy level + + align:start position:0% +corresponding to energy level + + + align:start position:0% +corresponding to energy level +differences divided by h-bar and so what + + align:start position:0% +differences divided by h-bar and so what + + + align:start position:0% +differences divided by h-bar and so what +frequencies will appear in the Fourier + + align:start position:0% +frequencies will appear in the Fourier + + + align:start position:0% +frequencies will appear in the Fourier +transform of the the spectrum and what + + align:start position:0% +transform of the the spectrum and what + + + align:start position:0% +transform of the the spectrum and what +are the amplitudes of those Fourier + + align:start position:0% +are the amplitudes of those Fourier + + + align:start position:0% +are the amplitudes of those Fourier +components you can calculate all those + + align:start position:0% +components you can calculate all those + + + align:start position:0% +components you can calculate all those +stuff it all comes from perturbation + + align:start position:0% +stuff it all comes from perturbation + + + align:start position:0% +stuff it all comes from perturbation +Theory these mixing coefficients you get + + align:start position:0% +Theory these mixing coefficients you get + + + align:start position:0% +Theory these mixing coefficients you get +by perturbation theory and remember if + + align:start position:0% +by perturbation theory and remember if + + + align:start position:0% +by perturbation theory and remember if +you have a transformation that + + align:start position:0% +you have a transformation that + + + align:start position:0% +you have a transformation that +diagonalizes the Hamiltonian that the + + align:start position:0% +diagonalizes the Hamiltonian that the + + + align:start position:0% +diagonalizes the Hamiltonian that the +eigenstates correspond to the columns of + + align:start position:0% +eigenstates correspond to the columns of + + + align:start position:0% +eigenstates correspond to the columns of +t dagger and the expression of the zero + + align:start position:0% +t dagger and the expression of the zero + + + align:start position:0% +t dagger and the expression of the zero +order states in terms of the eigenstates + + align:start position:0% +order states in terms of the eigenstates + + + align:start position:0% +order states in terms of the eigenstates +corresponds to either the columns of T + + align:start position:0% +corresponds to either the columns of T + + + align:start position:0% +corresponds to either the columns of T +or the rows of T dagger so once you do + + align:start position:0% +or the rows of T dagger so once you do + + + align:start position:0% +or the rows of T dagger so once you do +the perturbation Theory you can go to + + align:start position:0% +the perturbation Theory you can go to + + + align:start position:0% +the perturbation Theory you can go to +the time the frequency domain spectrum + + align:start position:0% +the time the frequency domain spectrum + + + align:start position:0% +the time the frequency domain spectrum +with intensities and frequencies or the + + align:start position:0% +with intensities and frequencies or the + + + align:start position:0% +with intensities and frequencies or the +time domain spectrum with amplitudes and + + align:start position:0% +time domain spectrum with amplitudes and + + + align:start position:0% +time domain spectrum with amplitudes and +frequencies it's all there + + align:start position:0% +frequencies it's all there + + + align:start position:0% +frequencies it's all there +this is a complete tool it's it's the + + align:start position:0% +this is a complete tool it's it's the + + + align:start position:0% +this is a complete tool it's it's the +kind of tool that you can use for an + + align:start position:0% +kind of tool that you can use for an + + + align:start position:0% +kind of tool that you can use for an +enormous number of problems and so you'd + + align:start position:0% +enormous number of problems and so you'd + + + align:start position:0% +enormous number of problems and so you'd +better get comfortable with perturbation + + align:start position:0% +better get comfortable with perturbation + + + align:start position:0% +better get comfortable with perturbation +theory because the people who don't + + align:start position:0% +theory because the people who don't + + + align:start position:0% +theory because the people who don't +aren't comfortable can't do anything + + align:start position:0% +aren't comfortable can't do anything + + + align:start position:0% +aren't comfortable can't do anything +except talk about it but if you want to + + align:start position:0% +except talk about it but if you want to + + + align:start position:0% +except talk about it but if you want to +actually solve problems especially + + align:start position:0% +actually solve problems especially + + + align:start position:0% +actually solve problems especially +problems on an exam you want to know how + + align:start position:0% +problems on an exam you want to know how + + + align:start position:0% +problems on an exam you want to know how +to use perturbation theory and you also + + align:start position:0% +to use perturbation theory and you also + + + align:start position:0% +to use perturbation theory and you also +want to know how to read and constructed + + align:start position:0% +want to know how to read and constructed + + + align:start position:0% +want to know how to read and constructed +the relevant notation in the vector + + align:start position:0% +the relevant notation in the vector + + + align:start position:0% +the relevant notation in the vector +picture because the vector picture and + + align:start position:0% +picture because the vector picture and + + + align:start position:0% +picture because the vector picture and +the matrix picture is the one where you + + align:start position:0% +the matrix picture is the one where you + + + align:start position:0% +the matrix picture is the one where you +see the entire structure of the problem + + align:start position:0% +see the entire structure of the problem + + + align:start position:0% +see the entire structure of the problem +and you can decide on how you're going + + align:start position:0% +and you can decide on how you're going + + + align:start position:0% +and you can decide on how you're going +to organize your time or what is you + + align:start position:0% +to organize your time or what is you + + + align:start position:0% +to organize your time or what is you +know what are the important things I'm + + align:start position:0% +know what are the important things I'm + + + align:start position:0% +know what are the important things I'm +going to get from this analysis and so + + align:start position:0% +going to get from this analysis and so + + + align:start position:0% +going to get from this analysis and so +it's much better than the Schrodinger + + align:start position:0% +it's much better than the Schrodinger + + + align:start position:0% +it's much better than the Schrodinger +picture because you would just have to + + align:start position:0% +picture because you would just have to + + + align:start position:0% +picture because you would just have to +you know with the Schrodinger picture + + align:start position:0% +you know with the Schrodinger picture + + + align:start position:0% +you know with the Schrodinger picture +you're just solving a differential + + align:start position:0% +you're just solving a differential + + + align:start position:0% +you're just solving a differential +equation and one problem at a time where + + align:start position:0% +equation and one problem at a time where + + + align:start position:0% +equation and one problem at a time where +it's you're with the matrix picture + + align:start position:0% +it's you're with the matrix picture + + + align:start position:0% +it's you're with the matrix picture +you're solving all problems at once this + + align:start position:0% +you're solving all problems at once this + + + align:start position:0% +you're solving all problems at once this +is really a wonderful thing and and so + + align:start position:0% +is really a wonderful thing and and so + + + align:start position:0% +is really a wonderful thing and and so +that's why I'm taking a very different + + align:start position:0% +that's why I'm taking a very different + + + align:start position:0% +that's why I'm taking a very different +path from what is in the textbooks + + align:start position:0% +path from what is in the textbooks + + + align:start position:0% +path from what is in the textbooks +your wonderful textbook Macquarie does + + align:start position:0% +your wonderful textbook Macquarie does + + + align:start position:0% +your wonderful textbook Macquarie does +not do second-order perturbation Theory + + align:start position:0% +not do second-order perturbation Theory + + + align:start position:0% +not do second-order perturbation Theory +so nothing you want can be calculated + + align:start position:0% +so nothing you want can be calculated + + + align:start position:0% +so nothing you want can be calculated +unless you're dealing with NMR and and + + align:start position:0% +unless you're dealing with NMR and and + + + align:start position:0% +unless you're dealing with NMR and and +you're dealing with magnetic dipole + + align:start position:0% +you're dealing with magnetic dipole + + + align:start position:0% +you're dealing with magnetic dipole +transitions and then you you can get a + + align:start position:0% +transitions and then you you can get a + + + align:start position:0% +transitions and then you you can get a +lot of good stuff from first-order + + align:start position:0% +lot of good stuff from first-order + + + align:start position:0% +lot of good stuff from first-order +perturbation theory and you can avoid + + align:start position:0% +perturbation theory and you can avoid + + + align:start position:0% +perturbation theory and you can avoid +second-order until you grow up okay I'm + + align:start position:0% +second-order until you grow up okay I'm + + + align:start position:0% +second-order until you grow up okay I'm +done I'll be talking about rigid rotor + + align:start position:0% +done I'll be talking about rigid rotor + + + align:start position:0% +done I'll be talking about rigid rotor +next time and I was talking about it + + align:start position:0% +next time and I was talking about it + + + align:start position:0% +next time and I was talking about it +also in an unconventional way \ No newline at end of file diff --git a/YZ9y4zcfCPs.txt b/YZ9y4zcfCPs.txt new file mode 100644 index 0000000000000000000000000000000000000000..418a04d620931c06a3288a5d9cd0c0e53b62aa01 --- /dev/null +++ b/YZ9y4zcfCPs.txt @@ -0,0 +1,9947 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu today we're going to talk + + align:start position:0% +ocw.mit.edu today we're going to talk + + + align:start position:0% +ocw.mit.edu today we're going to talk +all about moments of inera + + align:start position:0% +all about moments of inera + + + align:start position:0% +all about moments of inera +and the last time we did Muddy cards + + align:start position:0% +and the last time we did Muddy cards + + + align:start position:0% +and the last time we did Muddy cards +there were a lot of questions the most + + align:start position:0% +there were a lot of questions the most + + + align:start position:0% +there were a lot of questions the most +common question you know was where do + + align:start position:0% +common question you know was where do + + + align:start position:0% +common question you know was where do +all those terms come from and I'm going + + align:start position:0% +all those terms come from and I'm going + + + align:start position:0% +all those terms come from and I'm going +to do a brief kind of intro around that + + align:start position:0% +to do a brief kind of intro around that + + + align:start position:0% +to do a brief kind of intro around that +so as to get the rest of this to + + align:start position:0% +so as to get the rest of this to + + + align:start position:0% +so as to get the rest of this to +facilitate the rest of of the + + align:start position:0% +facilitate the rest of of the + + + align:start position:0% +facilitate the rest of of the +discussions + + align:start position:0% + + + + align:start position:0% + +uh kind of some basic assumptions here + + align:start position:0% +uh kind of some basic assumptions here + + + align:start position:0% +uh kind of some basic assumptions here +today we're going + + align:start position:0% + + + + align:start position:0% + +to consider + + align:start position:0% + + + + align:start position:0% + +bodies that rotate + + align:start position:0% + + + + align:start position:0% + +about their Center of + + align:start position:0% + + + + align:start position:0% + +mass or fixed + + align:start position:0% + + + + align:start position:0% + +points that's the kind of problems we're + + align:start position:0% +points that's the kind of problems we're + + + align:start position:0% +points that's the kind of problems we're +doing + + align:start position:0% +doing + + + align:start position:0% +doing +and + + align:start position:0% +and + + + align:start position:0% +and +secondly all through this lecture today + + align:start position:0% +secondly all through this lecture today + + + align:start position:0% +secondly all through this lecture today +there's four or five significant + + align:start position:0% +there's four or five significant + + + align:start position:0% +there's four or five significant +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +or conditions that are really important + + align:start position:0% +or conditions that are really important + + + align:start position:0% +or conditions that are really important +to the whole discussion I'm going to + + align:start position:0% +to the whole discussion I'm going to + + + align:start position:0% +to the whole discussion I'm going to +really try to highlight them I'm + + align:start position:0% +really try to highlight them I'm + + + align:start position:0% +really try to highlight them I'm +starting with two here the other one is + + align:start position:0% +starting with two here the other one is + + + align:start position:0% +starting with two here the other one is +we're going to use + + align:start position:0% + + + + align:start position:0% + +reference + + align:start position:0% + + + + align:start position:0% + +frames attached to the + + align:start position:0% + + + + align:start position:0% + +bodies it's why we did all that work in + + align:start position:0% +bodies it's why we did all that work in + + + align:start position:0% +bodies it's why we did all that work in +kinematics figuring out how to do + + align:start position:0% +kinematics figuring out how to do + + + align:start position:0% +kinematics figuring out how to do +velocities of things that are in have + + align:start position:0% +velocities of things that are in have + + + align:start position:0% +velocities of things that are in have +translating and rotating reference + + align:start position:0% +translating and rotating reference + + + align:start position:0% +translating and rotating reference +frames it's so that we can do these + + align:start position:0% +frames it's so that we can do these + + + align:start position:0% +frames it's so that we can do these +problems + + align:start position:0% +problems + + + align:start position:0% +problems +okay now F so this + + align:start position:0% +okay now F so this + + + align:start position:0% +okay now F so this +said here's + + align:start position:0% + + + + align:start position:0% + +a inertial + + align:start position:0% + + + + align:start position:0% + +frame here's some rigid + + align:start position:0% +frame here's some rigid + + + align:start position:0% +frame here's some rigid +body here's a point on it that's my + + align:start position:0% +body here's a point on it that's my + + + align:start position:0% +body here's a point on it that's my +origin and here is a set of coordinates + + align:start position:0% +origin and here is a set of coordinates + + + align:start position:0% +origin and here is a set of coordinates +attached to the rigid + + align:start position:0% + + + + align:start position:0% + +body the axyz system the body rotates + + align:start position:0% +body the axyz system the body rotates + + + align:start position:0% +body the axyz system the body rotates +and translates it goes with + + align:start position:0% +and translates it goes with + + + align:start position:0% +and translates it goes with +it + + align:start position:0% +it + + + align:start position:0% +it +and if we have consider a little piece + + align:start position:0% +and if we have consider a little piece + + + align:start position:0% +and if we have consider a little piece +of this body a little Mass part I'll + + align:start position:0% +of this body a little Mass part I'll + + + align:start position:0% +of this body a little Mass part I'll +call it little Mass element + + align:start position:0% +call it little Mass element + + + align:start position:0% +call it little Mass element +mi from here to here is some distance r + + align:start position:0% +mi from here to here is some distance r + + + align:start position:0% +mi from here to here is some distance r +i with respect to + + align:start position:0% +i with respect to + + + align:start position:0% +i with respect to +a then the angular + + align:start position:0% +a then the angular + + + align:start position:0% +a then the angular +momentum of that little Mass particle + + align:start position:0% +momentum of that little Mass particle + + + align:start position:0% +momentum of that little Mass particle +is by just by definition of angular + + align:start position:0% +is by just by definition of angular + + + align:start position:0% +is by just by definition of angular +momentum R cross p i and the p i p is + + align:start position:0% +momentum R cross p i and the p i p is + + + align:start position:0% +momentum R cross p i and the p i p is +always the linear momentum defined in an + + align:start position:0% +always the linear momentum defined in an + + + align:start position:0% +always the linear momentum defined in an +inertial frame okay that's the + + align:start position:0% +inertial frame okay that's the + + + align:start position:0% +inertial frame okay that's the +definition of angular + + align:start position:0% + + + + align:start position:0% + +momentum so youve you've seen this this + + align:start position:0% +momentum so youve you've seen this this + + + align:start position:0% +momentum so youve you've seen this this +little demo before but now so this is + + align:start position:0% +little demo before but now so this is + + + align:start position:0% +little demo before but now so this is +now my rigid body that I'm talking + + align:start position:0% +now my rigid body that I'm talking + + + align:start position:0% +now my rigid body that I'm talking +about it I'm going to in this case the + + align:start position:0% +about it I'm going to in this case the + + + align:start position:0% +about it I'm going to in this case the +axis of rotation is this + + align:start position:0% +axis of rotation is this + + + align:start position:0% +axis of rotation is this +one and I'm just going to Define my + + align:start position:0% +one and I'm just going to Define my + + + align:start position:0% +one and I'm just going to Define my +rigid body as essentially rotating about + + align:start position:0% +rigid body as essentially rotating about + + + align:start position:0% +rigid body as essentially rotating about +this fixed point this is a now and my + + align:start position:0% +this fixed point this is a now and my + + + align:start position:0% +this fixed point this is a now and my +coordinate system is um x y z so the + + align:start position:0% +coordinate system is um x y z so the + + + align:start position:0% +coordinate system is um x y z so the +rotation is Omega Z and this rigid body + + align:start position:0% +rotation is Omega Z and this rigid body + + + align:start position:0% +rotation is Omega Z and this rigid body +this is massless considers consists of + + align:start position:0% +this is massless considers consists of + + + align:start position:0% +this is massless considers consists of +the single point Mass Okay so we've done + + align:start position:0% +the single point Mass Okay so we've done + + + align:start position:0% +the single point Mass Okay so we've done +this before but we tended to do this + + align:start position:0% +this before but we tended to do this + + + align:start position:0% +this before but we tended to do this +kind of problem using polar coordinates + + align:start position:0% +kind of problem using polar coordinates + + + align:start position:0% +kind of problem using polar coordinates +and now I really want to just strictly + + align:start position:0% +and now I really want to just strictly + + + align:start position:0% +and now I really want to just strictly +think in terms of XYZ the answers come + + align:start position:0% +think in terms of XYZ the answers come + + + align:start position:0% +think in terms of XYZ the answers come +out exactly the same polar coordinates + + align:start position:0% +out exactly the same polar coordinates + + + align:start position:0% +out exactly the same polar coordinates +also moved you could do this in R hat + + align:start position:0% +also moved you could do this in R hat + + + align:start position:0% +also moved you could do this in R hat +Theta hat Z we're going to do it an + + align:start position:0% +Theta hat Z we're going to do it an + + + align:start position:0% +Theta hat Z we're going to do it an +XYZ XYZ attach to the body + + align:start position:0% + + + + align:start position:0% + +and why is going into the board we + + align:start position:0% +and why is going into the board we + + + align:start position:0% +and why is going into the board we +have we'll have no values in the y + + align:start position:0% +have we'll have no values in the y + + + align:start position:0% +have we'll have no values in the y +direction for this problem here's our + + align:start position:0% +direction for this problem here's our + + + align:start position:0% +direction for this problem here's our +little Mass we'll call it + + align:start position:0% +little Mass we'll call it + + + align:start position:0% +little Mass we'll call it +M1 it's at a position out here + + align:start position:0% +M1 it's at a position out here + + + align:start position:0% +M1 it's at a position out here +X1 Z1 or its coordinates and Y is + + align:start position:0% +X1 Z1 or its coordinates and Y is + + + align:start position:0% +X1 Z1 or its coordinates and Y is +zero and we want to compute its angular + + align:start position:0% +zero and we want to compute its angular + + + align:start position:0% +zero and we want to compute its angular +momentum H1 with respect to + + align:start position:0% +momentum H1 with respect to + + + align:start position:0% +momentum H1 with respect to +a + + align:start position:0% + + + + align:start position:0% + +okay that's our R1 a cross P1 in O and + + align:start position:0% +okay that's our R1 a cross P1 in O and + + + align:start position:0% +okay that's our R1 a cross P1 in O and +for this problem that's X X1 in the I + + align:start position:0% +for this problem that's X X1 in the I + + + align:start position:0% +for this problem that's X X1 in the I +hat plus Z1 in the K hat that's the + + align:start position:0% +hat plus Z1 in the K hat that's the + + + align:start position:0% +hat plus Z1 in the K hat that's the +r cross p and p is mass time you know + + align:start position:0% +r cross p and p is mass time you know + + + align:start position:0% +r cross p and p is mass time you know +it's mass time velocity M1 and the + + align:start position:0% +it's mass time velocity M1 and the + + + align:start position:0% +it's mass time velocity M1 and the +velocity is just Omega cross R we've + + align:start position:0% +velocity is just Omega cross R we've + + + align:start position:0% +velocity is just Omega cross R we've +done this before so there's going to be + + align:start position:0% +done this before so there's going to be + + + align:start position:0% +done this before so there's going to be +a we need a length on this thing + + align:start position:0% + + + + align:start position:0% + +we've done this enough times before I'm + + align:start position:0% +we've done this enough times before I'm + + + align:start position:0% +we've done this enough times before I'm +assuming you can make this leap with me + + align:start position:0% +assuming you can make this leap with me + + + align:start position:0% +assuming you can make this leap with me +the + + align:start position:0% + + + + align:start position:0% + +the momentum is into the board it's in + + align:start position:0% +the momentum is into the board it's in + + + align:start position:0% +the momentum is into the board it's in +the y + + align:start position:0% +the y + + + align:start position:0% +the y +direction the linear momentum is R cross + + align:start position:0% +direction the linear momentum is R cross + + + align:start position:0% +direction the linear momentum is R cross +with that + + align:start position:0% +with that + + + align:start position:0% +with that +and that will give + + align:start position:0% +and that will give + + + align:start position:0% +and that will give +us let me write it little yeah Omega Z + + align:start position:0% +us let me write it little yeah Omega Z + + + align:start position:0% +us let me write it little yeah Omega Z +so that's the linear momentum it's in + + align:start position:0% +so that's the linear momentum it's in + + + align:start position:0% +so that's the linear momentum it's in +the J Direction its velocity is x 1 + + align:start position:0% +the J Direction its velocity is x 1 + + + align:start position:0% +the J Direction its velocity is x 1 +Omega Z it's the radius times the + + align:start position:0% +Omega Z it's the radius times the + + + align:start position:0% +Omega Z it's the radius times the +rotation rate is the velocity the + + align:start position:0% +rotation rate is the velocity the + + + align:start position:0% +rotation rate is the velocity the +direction is that direction so this is + + align:start position:0% +direction is that direction so this is + + + align:start position:0% +direction is that direction so this is +your momentum you multiply out this + + align:start position:0% +your momentum you multiply out this + + + align:start position:0% +your momentum you multiply out this +cross product you get two + + align:start position:0% +cross product you get two + + + align:start position:0% +cross product you get two +terms M1 + + align:start position:0% + + + + align:start position:0% + +X12 Omega z k + + align:start position:0% +X12 Omega z k + + + align:start position:0% +X12 Omega z k +minus M1 X1 Z1 Omega z + + align:start position:0% + + + + align:start position:0% + +i and these two terms then we would + + align:start position:0% +i and these two terms then we would + + + align:start position:0% +i and these two terms then we would +identify this is the angular momentum in + + align:start position:0% +identify this is the angular momentum in + + + align:start position:0% +identify this is the angular momentum in +the K Direction the angular momentum in + + align:start position:0% +the K Direction the angular momentum in + + + align:start position:0% +the K Direction the angular momentum in +the I Direction there doesn't happen to + + align:start position:0% +the I Direction there doesn't happen to + + + align:start position:0% +the I Direction there doesn't happen to +be any in the Z Direction in general + + align:start position:0% +be any in the Z Direction in general + + + align:start position:0% +be any in the Z Direction in general +there could be but this is H for this + + align:start position:0% +there could be but this is H for this + + + align:start position:0% +there could be but this is H for this +particle uh particle + + align:start position:0% +particle uh particle + + + align:start position:0% +particle uh particle +one um let me write it I'm just going to + + align:start position:0% +one um let me write it I'm just going to + + + align:start position:0% +one um let me write it I'm just going to +want to particularly emphasize this one + + align:start position:0% +want to particularly emphasize this one + + + align:start position:0% +want to particularly emphasize this one +is the this is excuse me Z and this is + + align:start position:0% +is the this is excuse me Z and this is + + + align:start position:0% +is the this is excuse me Z and this is +the piece we'd call + + align:start position:0% +the piece we'd call + + + align:start position:0% +the piece we'd call +h + + align:start position:0% +h + + + align:start position:0% +h +x so there's a component of the angular + + align:start position:0% +x so there's a component of the angular + + + align:start position:0% +x so there's a component of the angular +momentum that's in the Z direction + + align:start position:0% +momentum that's in the Z direction + + + align:start position:0% +momentum that's in the Z direction +there's a component in the X + + align:start position:0% + + + + align:start position:0% + +direction we know that if we compute + + align:start position:0% +direction we know that if we compute + + + align:start position:0% +direction we know that if we compute +just to carry the + + align:start position:0% +just to carry the + + + align:start position:0% +just to carry the +uh the previous word a tie it back to + + align:start position:0% +uh the previous word a tie it back to + + + align:start position:0% +uh the previous word a tie it back to +the previous work a little further d by + + align:start position:0% +the previous work a little further d by + + + align:start position:0% +the previous work a little further d by +DT of H1 a gives us the torqu the + + align:start position:0% +DT of H1 a gives us the torqu the + + + align:start position:0% +DT of H1 a gives us the torqu the +external torqu in the system a vector of + + align:start position:0% +external torqu in the system a vector of + + + align:start position:0% +external torqu in the system a vector of +torqus when we compute that out I don't + + align:start position:0% +torqus when we compute that out I don't + + + align:start position:0% +torqus when we compute that out I don't +I'm not going to calculate it we don't I + + align:start position:0% +I'm not going to calculate it we don't I + + + align:start position:0% +I'm not going to calculate it we don't I +don't need it for the purposes of the + + align:start position:0% +don't need it for the purposes of the + + + align:start position:0% +don't need it for the purposes of the +rest of the discussion this one gives + + align:start position:0% +rest of the discussion this one gives + + + align:start position:0% +rest of the discussion this one gives +you Omega Z dot term this one gets two + + align:start position:0% +you Omega Z dot term this one gets two + + + align:start position:0% +you Omega Z dot term this one gets two +terms because you have to take the + + align:start position:0% +terms because you have to take the + + + align:start position:0% +terms because you have to take the +derivative of I so you get three terms + + align:start position:0% +derivative of I so you get three terms + + + align:start position:0% +derivative of I so you get three terms +which are torque in the X torque in the + + align:start position:0% +which are torque in the X torque in the + + + align:start position:0% +which are torque in the X torque in the +Y torque in the Z directions two of them + + align:start position:0% +Y torque in the Z directions two of them + + + align:start position:0% +Y torque in the Z directions two of them +are static because it's trying to bend + + align:start position:0% +are static because it's trying to bend + + + align:start position:0% +are static because it's trying to bend +this thing back and out and one of them + + align:start position:0% +this thing back and out and one of them + + + align:start position:0% +this thing back and out and one of them +the Z Direction one is the one that + + align:start position:0% +the Z Direction one is the one that + + + align:start position:0% +the Z Direction one is the one that +makes it spin faster + + align:start position:0% +makes it spin faster + + + align:start position:0% +makes it spin faster +okay so You' we've seen that that's a + + align:start position:0% +okay so You' we've seen that that's a + + + align:start position:0% +okay so You' we've seen that that's a +review + + align:start position:0% +review + + + align:start position:0% +review +and to make the leap from that to rigid + + align:start position:0% +and to make the leap from that to rigid + + + align:start position:0% +and to make the leap from that to rigid +bodies + + align:start position:0% + + + + align:start position:0% + +Capital H now a collection of particles + + align:start position:0% +Capital H now a collection of particles + + + align:start position:0% +Capital H now a collection of particles +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +its the axis the origin attached to the + + align:start position:0% +its the axis the origin attached to the + + + align:start position:0% +its the axis the origin attached to the +rigid + + align:start position:0% +rigid + + + align:start position:0% +rigid +body is going to be the summation over + + align:start position:0% +body is going to be the summation over + + + align:start position:0% +body is going to be the summation over +all the little M particles + + align:start position:0% + + + + align:start position:0% + +their position Vector crossed with the + + align:start position:0% +their position Vector crossed with the + + + align:start position:0% +their position Vector crossed with the +linear momentum of all those little Mass + + align:start position:0% +linear momentum of all those little Mass + + + align:start position:0% +linear momentum of all those little Mass +particles sum all that up because it's a + + align:start position:0% +particles sum all that up because it's a + + + align:start position:0% +particles sum all that up because it's a +rigid body this is always something of + + align:start position:0% +rigid body this is always something of + + + align:start position:0% +rigid body this is always something of +the form that looks like Omega cross r m + + align:start position:0% +the form that looks like Omega cross r m + + + align:start position:0% +the form that looks like Omega cross r m +Omega cross R and I can then write this + + align:start position:0% +Omega cross R and I can then write this + + + align:start position:0% +Omega cross R and I can then write this +as the + + align:start position:0% +as the + + + align:start position:0% +as the +summation + + align:start position:0% +summation + + + align:start position:0% +summation +of I of the + + align:start position:0% + + + + align:start position:0% + +MI r + + align:start position:0% +MI r + + + align:start position:0% +MI r +i a + + align:start position:0% +i a + + + align:start position:0% +i a +cross Omega with respect to O cross r i + + align:start position:0% +cross Omega with respect to O cross r i + + + align:start position:0% +cross Omega with respect to O cross r i +a that gives you the velocity times the + + align:start position:0% +a that gives you the velocity times the + + + align:start position:0% +a that gives you the velocity times the +moment M gives you the linear momentum + + align:start position:0% +moment M gives you the linear momentum + + + align:start position:0% +moment M gives you the linear momentum +times the cross with this one again + + align:start position:0% +times the cross with this one again + + + align:start position:0% +times the cross with this one again +makes it into an angular momentum so + + align:start position:0% +makes it into an angular momentum so + + + align:start position:0% +makes it into an angular momentum so +every M the angular momentum of every + + align:start position:0% +every M the angular momentum of every + + + align:start position:0% +every M the angular momentum of every +particle the term the bits of this come + + align:start position:0% +particle the term the bits of this come + + + align:start position:0% +particle the term the bits of this come +out looking like an like an R SAR + + align:start position:0% +out looking like an like an R SAR + + + align:start position:0% +out looking like an like an R SAR +Omega or at least has has + + align:start position:0% +Omega or at least has has + + + align:start position:0% +Omega or at least has has +um dimensions of R 2 Omega these can be + + align:start position:0% +um dimensions of R 2 Omega these can be + + + align:start position:0% +um dimensions of R 2 Omega these can be +like X1 SAR but these can also be ends + + align:start position:0% +like X1 SAR but these can also be ends + + + align:start position:0% +like X1 SAR but these can also be ends +up being terms like X1 Z1 those cross + + align:start position:0% +up being terms like X1 Z1 those cross + + + align:start position:0% +up being terms like X1 Z1 those cross +product terms but in general these + + align:start position:0% +product terms but in general these + + + align:start position:0% +product terms but in general these +things all add + + align:start position:0% +things all add + + + align:start position:0% +things all add +up and this is this is a vector + + align:start position:0% +up and this is this is a vector + + + align:start position:0% +up and this is this is a vector +this is a vector so this is a vector CR + + align:start position:0% +this is a vector so this is a vector CR + + + align:start position:0% +this is a vector so this is a vector CR +these are all vectors the results of + + align:start position:0% +these are all vectors the results of + + + align:start position:0% +these are all vectors the results of +vector + + align:start position:0% + + + + align:start position:0% + +right and therefore we would break this + + align:start position:0% +right and therefore we would break this + + + align:start position:0% +right and therefore we would break this +down this whole thing once you write all + + align:start position:0% +down this whole thing once you write all + + + align:start position:0% +down this whole thing once you write all +that out and sum it all up you're going + + align:start position:0% +that out and sum it all up you're going + + + align:start position:0% +that out and sum it all up you're going +to get a piece of it that we would say + + align:start position:0% +to get a piece of it that we would say + + + align:start position:0% +to get a piece of it that we would say +is in that is in the IH hat Direction + + align:start position:0% +is in that is in the IH hat Direction + + + align:start position:0% +is in that is in the IH hat Direction +and we call that + + align:start position:0% +and we call that + + + align:start position:0% +and we call that +HX another piece that's in the J hat + + align:start position:0% +HX another piece that's in the J hat + + + align:start position:0% +HX another piece that's in the J hat +Direction which we call H1 Y and HZ in + + align:start position:0% +Direction which we call H1 Y and HZ in + + + align:start position:0% +Direction which we call H1 Y and HZ in +the K + + align:start position:0% +the K + + + align:start position:0% +the K +hat that's just how that'll all shake + + align:start position:0% +hat that's just how that'll all shake + + + align:start position:0% +hat that's just how that'll all shake +out you're going to get three in general + + align:start position:0% +out you're going to get three in general + + + align:start position:0% +out you're going to get three in general +you get three + + align:start position:0% + + + + align:start position:0% + +parts + + align:start position:0% + + + + align:start position:0% + +yeah why do we have ma Mass multiplied + + align:start position:0% +yeah why do we have ma Mass multiplied + + + align:start position:0% +yeah why do we have ma Mass multiplied +by a position Vector times momentum + + align:start position:0% +by a position Vector times momentum + + + align:start position:0% +by a position Vector times momentum +because that is the definition of + + align:start position:0% +because that is the definition of + + + align:start position:0% +because that is the definition of +angular + + align:start position:0% + + + + align:start position:0% + +momentum it's R cross P + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +right ah I see what I've done yeah + + align:start position:0% +right ah I see what I've done yeah + + + align:start position:0% +right ah I see what I've done yeah +you're right this m doesn't belong I got + + align:start position:0% +you're right this m doesn't belong I got + + + align:start position:0% +you're right this m doesn't belong I got +ahead of myself it doesn't belong here + + align:start position:0% +ahead of myself it doesn't belong here + + + align:start position:0% +ahead of myself it doesn't belong here +when it pops out of this to here thanks + + align:start position:0% +when it pops out of this to here thanks + + + align:start position:0% +when it pops out of this to here thanks +for catching that + + align:start position:0% +for catching that + + + align:start position:0% +for catching that +absolutely + + align:start position:0% + + + + align:start position:0% + +right so we're in the pract each of + + align:start position:0% +right so we're in the pract each of + + + align:start position:0% +right so we're in the pract each of +these each of these is every term here + + align:start position:0% +these each of these is every term here + + + align:start position:0% +these each of these is every term here +is made up of things that look like + + align:start position:0% +is made up of things that look like + + + align:start position:0% +is made up of things that look like +X1 Z1 M1 Omega X + + align:start position:0% +X1 Z1 M1 Omega X + + + align:start position:0% +X1 Z1 M1 Omega X +or Omega y or Omega Z because this is a + + align:start position:0% +or Omega y or Omega Z because this is a + + + align:start position:0% +or Omega y or Omega Z because this is a +vector and it can have three components + + align:start position:0% +vector and it can have three components + + + align:start position:0% +vector and it can have three components +a piece in the eye a piece in the J + + align:start position:0% +a piece in the eye a piece in the J + + + align:start position:0% +a piece in the eye a piece in the J +piece in the K Direction so when + + align:start position:0% +piece in the K Direction so when + + + align:start position:0% +piece in the K Direction so when +you there's a lot of possible terms and + + align:start position:0% +you there's a lot of possible terms and + + + align:start position:0% +you there's a lot of possible terms and +we're in the practice of writing this + + align:start position:0% + + + + align:start position:0% + +out this + + align:start position:0% + + + + align:start position:0% + +H Vector can be written WR then as a + + align:start position:0% +H Vector can be written WR then as a + + + align:start position:0% +H Vector can be written WR then as a +um I'm going to run out of room + + align:start position:0% + + + + align:start position:0% + +here so the HX term the piece that comes + + align:start position:0% +here so the HX term the piece that comes + + + align:start position:0% +here so the HX term the piece that comes +out with all little bits in the I + + align:start position:0% +out with all little bits in the I + + + align:start position:0% +out with all little bits in the I +Direction when you just break it apart + + align:start position:0% +Direction when you just break it apart + + + align:start position:0% +Direction when you just break it apart +we would write it + + align:start position:0% +we would write it + + + align:start position:0% +we would write it +I + + align:start position:0% +I + + + align:start position:0% +I +XX Omega x + + + align:start position:0% +XX Omega x + + + + align:start position:0% +XX Omega x + +ixy Omega y plus + + align:start position:0% +ixy Omega y plus + + + align:start position:0% +ixy Omega y plus +I X Z Omega + + align:start position:0% +I X Z Omega + + + align:start position:0% +I X Z Omega +Z these are all all the I terms that + + align:start position:0% +Z these are all all the I terms that + + + align:start position:0% +Z these are all all the I terms that +float out of + + align:start position:0% +float out of + + + align:start position:0% +float out of +this we just write them we just collect + + align:start position:0% +this we just write them we just collect + + + align:start position:0% +this we just write them we just collect +them together all the ones that are + + align:start position:0% +them together all the ones that are + + + align:start position:0% +them together all the ones that are +multiplied by om GA X ends up being some + + align:start position:0% +multiplied by om GA X ends up being some + + + align:start position:0% +multiplied by om GA X ends up being some +terms that look like sums of + + align:start position:0% + + + + align:start position:0% + +Mi xmi Z2 terms and there's some y s + + align:start position:0% +Mi xmi Z2 terms and there's some y s + + + align:start position:0% +Mi xmi Z2 terms and there's some y s +terms but we collect them all together + + align:start position:0% +terms but we collect them all together + + + align:start position:0% +terms but we collect them all together +and we call this constant in front of it + + align:start position:0% +and we call this constant in front of it + + + align:start position:0% +and we call this constant in front of it +ixx it's just what floats out of this + + align:start position:0% +ixx it's just what floats out of this + + + align:start position:0% +ixx it's just what floats out of this +stuff we break it into three pieces the + + align:start position:0% +stuff we break it into three pieces the + + + align:start position:0% +stuff we break it into three pieces the +part of the angular momentum due to the + + align:start position:0% +part of the angular momentum due to the + + + align:start position:0% +part of the angular momentum due to the +rotation in the X the part due to the + + align:start position:0% +rotation in the X the part due to the + + + align:start position:0% +rotation in the X the part due to the +rotation in the Y the part due to the + + align:start position:0% +rotation in the Y the part due to the + + + align:start position:0% +rotation in the Y the part due to the +rotation in the Z and you do the same + + align:start position:0% +rotation in the Z and you do the same + + + align:start position:0% +rotation in the Z and you do the same +thing for + + align:start position:0% +thing for + + + align:start position:0% +thing for +Hy you get an + + align:start position:0% +Hy you get an + + + align:start position:0% +Hy you get an +i y x Omega X plus an i y y Omega y plus + + align:start position:0% +i y x Omega X plus an i y y Omega y plus + + + align:start position:0% +i y x Omega X plus an i y y Omega y plus +an i y z Omega Z and you finally get an + + align:start position:0% +an i y z Omega Z and you finally get an + + + align:start position:0% +an i y z Omega Z and you finally get an +HZ + + align:start position:0% +HZ + + + align:start position:0% +HZ +term i z x Omega x i z z y Omega + + align:start position:0% +term i z x Omega x i z z y Omega + + + align:start position:0% +term i z x Omega x i z z y Omega +y i + + align:start position:0% +y i + + + align:start position:0% +y i +ZZ Omega Z okay that's everything that + + align:start position:0% +ZZ Omega Z okay that's everything that + + + align:start position:0% +ZZ Omega Z okay that's everything that +falls out of just doing this + + align:start position:0% + + + + align:start position:0% + +calculation and we are in the habit of + + align:start position:0% +calculation and we are in the habit of + + + align:start position:0% +calculation and we are in the habit of +writing that in a matrix notation + + align:start position:0% + + + + align:start position:0% + +as the product of this thing called the + + align:start position:0% +as the product of this thing called the + + + align:start position:0% +as the product of this thing called the +inertia + + align:start position:0% + + + + align:start position:0% + +Matrix and so forth with this bottom + + align:start position:0% +Matrix and so forth with this bottom + + + align:start position:0% +Matrix and so forth with this bottom +term here saying be i z z multiplied by + + align:start position:0% +term here saying be i z z multiplied by + + + align:start position:0% +term here saying be i z z multiplied by +Omega X Omega y Omega + + align:start position:0% +Omega X Omega y Omega + + + align:start position:0% +Omega X Omega y Omega +Z you multiply that times the top row + + align:start position:0% +Z you multiply that times the top row + + + align:start position:0% +Z you multiply that times the top row +you get + + align:start position:0% +you get + + + align:start position:0% +you get +HX middle row you get Hy bottom row you + + align:start position:0% +HX middle row you get Hy bottom row you + + + align:start position:0% +HX middle row you get Hy bottom row you +get the + + align:start position:0% +get the + + + align:start position:0% +get the +HC so where this stuff comes from it's + + align:start position:0% +HC so where this stuff comes from it's + + + align:start position:0% +HC so where this stuff comes from it's +just from conducting carrying out this + + align:start position:0% +just from conducting carrying out this + + + align:start position:0% +just from conducting carrying out this +summation over all the mass + + align:start position:0% +summation over all the mass + + + align:start position:0% +summation over all the mass +bits so it basically starts with the + + align:start position:0% +bits so it basically starts with the + + + align:start position:0% +bits so it basically starts with the +definition of angular momentum and this + + align:start position:0% +definition of angular momentum and this + + + align:start position:0% +definition of angular momentum and this +is just a convenient way to write + + align:start position:0% + + + + align:start position:0% + +it so for + + align:start position:0% +it so for + + + align:start position:0% +it so for +example the I + + align:start position:0% +example the I + + + align:start position:0% +example the I +XZ term + + align:start position:0% + + + + align:start position:0% + +the one in the upper right there that's + + align:start position:0% +the one in the upper right there that's + + + align:start position:0% +the one in the upper right there that's +part of HX the ixz + + align:start position:0% + + + + align:start position:0% + +term is minus the + + align:start position:0% +term is minus the + + + align:start position:0% +term is minus the +summation of all the little Mass + + align:start position:0% +summation of all the little Mass + + + align:start position:0% +summation of all the little Mass +bits times their location XI + + align:start position:0% +bits times their location XI + + + align:start position:0% +bits times their location XI +zi and this see XZ always matches + + align:start position:0% +zi and this see XZ always matches + + + align:start position:0% +zi and this see XZ always matches +XZ and when you want to do this over a + + align:start position:0% +XZ and when you want to do this over a + + + align:start position:0% +XZ and when you want to do this over a +continuous object you integrate that + + align:start position:0% +continuous object you integrate that + + + align:start position:0% +continuous object you integrate that +and for + + align:start position:0% + + + + align:start position:0% + +izz this is the summation + + align:start position:0% +izz this is the summation + + + align:start position:0% +izz this is the summation +of over + + align:start position:0% +of over + + + align:start position:0% +of over +I all the bits of m + + align:start position:0% +I all the bits of m + + + align:start position:0% +I all the bits of m +i x i 2 + y i + + align:start position:0% +i x i 2 + y i + + + align:start position:0% +i x i 2 + y i +2 okay so in general this by as + + align:start position:0% +2 okay so in general this by as + + + align:start position:0% +2 okay so in general this by as +summations that's where these terms come + + align:start position:0% +summations that's where these terms come + + + align:start position:0% +summations that's where these terms come +from they've just come they' started + + align:start position:0% +from they've just come they' started + + + align:start position:0% +from they've just come they' started +with this + + align:start position:0% + + + + align:start position:0% + +calculation okay and in general from + + align:start position:0% +calculation okay and in general from + + + align:start position:0% +calculation okay and in general from +that + + align:start position:0% + + + + align:start position:0% + +calculation so for our one particle + + align:start position:0% +calculation so for our one particle + + + align:start position:0% +calculation so for our one particle +system for this thing so this is x and z + + align:start position:0% +system for this thing so this is x and z + + + align:start position:0% +system for this thing so this is x and z +it's one single + + align:start position:0% +it's one single + + + align:start position:0% +it's one single +particle so for our one particle system + + align:start position:0% + + + + align:start position:0% + +and there's no y one in here because + + align:start position:0% +and there's no y one in here because + + + align:start position:0% +and there's no y one in here because +it's zero in this problem right there's + + align:start position:0% +it's zero in this problem right there's + + + align:start position:0% +it's zero in this problem right there's +no it's coordinate of that little Mass + + align:start position:0% +no it's coordinate of that little Mass + + + align:start position:0% +no it's coordinate of that little Mass +particle is X1 0 y1 so in general this + + align:start position:0% +particle is X1 0 y1 so in general this + + + align:start position:0% +particle is X1 0 y1 so in general this +is x i^ 2 + y i^ s but that's zero so + + align:start position:0% +is x i^ 2 + y i^ s but that's zero so + + + align:start position:0% +is x i^ 2 + y i^ s but that's zero so +it's just mx1 + + align:start position:0% + + + + align:start position:0% + +2 so that's where all these things come + + align:start position:0% +2 so that's where all these things come + + + align:start position:0% +2 so that's where all these things come +from + + align:start position:0% +from + + + align:start position:0% +from +now let's kind of look at + + align:start position:0% +now let's kind of look at + + + align:start position:0% +now let's kind of look at +uh the units of these things are always + + align:start position:0% +uh the units of these things are always + + + align:start position:0% +uh the units of these things are always +masstimes length + + align:start position:0% +masstimes length + + + align:start position:0% +masstimes length +squ the diagonal + + align:start position:0% +squ the diagonal + + + align:start position:0% +squ the diagonal +terms the x ixx i y y i ZZ terms will + + align:start position:0% +terms the x ixx i y y i ZZ terms will + + + align:start position:0% +terms the x ixx i y y i ZZ terms will +all be of the form of something + + align:start position:0% +all be of the form of something + + + align:start position:0% +all be of the form of something +squared and what it is is it's always + + align:start position:0% +squared and what it is is it's always + + + align:start position:0% +squared and what it is is it's always +just the distance of the mass + + align:start position:0% +just the distance of the mass + + + align:start position:0% +just the distance of the mass +particles from the axis of rotation call + + align:start position:0% +particles from the axis of rotation call + + + align:start position:0% +particles from the axis of rotation call +that R it's just a summation of this + + align:start position:0% +that R it's just a summation of this + + + align:start position:0% +that R it's just a summation of this +perpendicular distance from the axis of + + align:start position:0% +perpendicular distance from the axis of + + + align:start position:0% +perpendicular distance from the axis of +rotation for izz the axis of rotation is + + align:start position:0% +rotation for izz the axis of rotation is + + + align:start position:0% +rotation for izz the axis of rotation is +z and this piece here is always the + + align:start position:0% +z and this piece here is always the + + + align:start position:0% +z and this piece here is always the +distance squared that the mass particle + + align:start position:0% +distance squared that the mass particle + + + align:start position:0% +distance squared that the mass particle +is from the axis of + + align:start position:0% +is from the axis of + + + align:start position:0% +is from the axis of +rotation okay now that that's kind of + + align:start position:0% +rotation okay now that that's kind of + + + align:start position:0% +rotation okay now that that's kind of +that's the setup for + + align:start position:0% +that's the setup for + + + align:start position:0% +that's the setup for +today and we want to get on the real + + align:start position:0% +today and we want to get on the real + + + align:start position:0% +today and we want to get on the real +meat of the discussion are talking about + + align:start position:0% +meat of the discussion are talking about + + + align:start position:0% +meat of the discussion are talking about +things like the + + align:start position:0% +things like the + + + align:start position:0% +things like the +uh what principal axes are and so forth + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so now we're going to move on to the + + align:start position:0% +so now we're going to move on to the + + + align:start position:0% +so now we're going to move on to the +part of this conversation about + + align:start position:0% +part of this conversation about + + + align:start position:0% +part of this conversation about +principal axes + + align:start position:0% + + + + align:start position:0% + +so really important + + align:start position:0% + + + + align:start position:0% + +point for every rigid + + align:start position:0% +point for every rigid + + + align:start position:0% +point for every rigid +body for even weird ones for every rigid + + align:start position:0% +body for even weird ones for every rigid + + + align:start position:0% +body for even weird ones for every rigid +body there is a coordinate system that + + align:start position:0% +body there is a coordinate system that + + + align:start position:0% +body there is a coordinate system that +you can attach to this body an XYZ set + + align:start position:0% +you can attach to this body an XYZ set + + + align:start position:0% +you can attach to this body an XYZ set +of orthogonal coordinates that you can + + align:start position:0% +of orthogonal coordinates that you can + + + align:start position:0% +of orthogonal coordinates that you can +fix in this body such that you can make + + align:start position:0% +fix in this body such that you can make + + + align:start position:0% +fix in this body such that you can make +the + + align:start position:0% +the + + + align:start position:0% +the +this inertia + + align:start position:0% +this inertia + + + align:start position:0% +this inertia +Matrix have be + + align:start position:0% +Matrix have be + + + align:start position:0% +Matrix have be +diagonal any weird body at all there is + + align:start position:0% +diagonal any weird body at all there is + + + align:start position:0% +diagonal any weird body at all there is +a set of coordinates that if you use + + align:start position:0% +a set of coordinates that if you use + + + align:start position:0% +a set of coordinates that if you use +that set this this Matrix turns out to + + align:start position:0% +that set this this Matrix turns out to + + + align:start position:0% +that set this this Matrix turns out to +be diagonal and in terms of what that + + align:start position:0% +be diagonal and in terms of what that + + + align:start position:0% +be diagonal and in terms of what that +means in Dynamics + + align:start position:0% +means in Dynamics + + + align:start position:0% +means in Dynamics +terms is if you then rotate the + + align:start position:0% +terms is if you then rotate the + + + align:start position:0% +terms is if you then rotate the +object about one of those axes it will + + align:start position:0% +object about one of those axes it will + + + align:start position:0% +object about one of those axes it will +be dynamically + + align:start position:0% + + + + align:start position:0% + +balanced and so when you rotate a shaft + + align:start position:0% +balanced and so when you rotate a shaft + + + align:start position:0% +balanced and so when you rotate a shaft +this is a this is an an object for which + + align:start position:0% +this is a this is an an object for which + + + align:start position:0% +this is a this is an an object for which +I + + align:start position:0% +I + + + align:start position:0% +I +know it's a circular uniform disc one of + + align:start position:0% +know it's a circular uniform disc one of + + + align:start position:0% +know it's a circular uniform disc one of +the axes through the center is a + + align:start position:0% +the axes through the center is a + + + align:start position:0% +the axes through the center is a +principal axis and if I rotate the + + align:start position:0% +principal axis and if I rotate the + + + align:start position:0% +principal axis and if I rotate the +object about that this one the hole is + + align:start position:0% +object about that this one the hole is + + + align:start position:0% +object about that this one the hole is +kind of out around so wobbles a bit but + + align:start position:0% +kind of out around so wobbles a bit but + + + align:start position:0% +kind of out around so wobbles a bit but +if I rotate it about that it will have + + align:start position:0% +if I rotate it about that it will have + + + align:start position:0% +if I rotate it about that it will have +no it will make no torqus about this + + align:start position:0% +no it will make no torqus about this + + + align:start position:0% +no it will make no torqus about this +axis that are because it's + + align:start position:0% +axis that are because it's + + + align:start position:0% +axis that are because it's +unbalanced okay that's that's + + align:start position:0% +unbalanced okay that's that's + + + align:start position:0% +unbalanced okay that's that's +essentially the dynamic meaning of + + align:start position:0% +essentially the dynamic meaning of + + + align:start position:0% +essentially the dynamic meaning of +principal axis the axis about which you + + align:start position:0% +principal axis the axis about which you + + + align:start position:0% +principal axis the axis about which you +can rotate the thing and and it'll just + + align:start position:0% +can rotate the thing and and it'll just + + + align:start position:0% +can rotate the thing and and it'll just +be smooth no no out of away from the + + align:start position:0% +be smooth no no out of away from the + + + align:start position:0% +be smooth no no out of away from the +axis torqus okay so that's so those are + + align:start position:0% +axis torqus okay so that's so those are + + + align:start position:0% +axis torqus okay so that's so those are +pretty important we want to know what + + align:start position:0% +pretty important we want to know what + + + align:start position:0% +pretty important we want to know what +those are for rigid bodies and how to + + align:start position:0% +those are for rigid bodies and how to + + + align:start position:0% +those are for rigid bodies and how to +find them so there's a mathematical way + + align:start position:0% +find them so there's a mathematical way + + + align:start position:0% +find them so there's a mathematical way +to find them and you can just read about + + align:start position:0% +to find them and you can just read about + + + align:start position:0% +to find them and you can just read about +it in the textbook + + align:start position:0% +it in the textbook + + + align:start position:0% +it in the textbook +the uh you know it's + + align:start position:0% +the uh you know it's + + + align:start position:0% +the uh you know it's +a sort of a um trying to think the + + align:start position:0% +a sort of a um trying to think the + + + align:start position:0% +a sort of a um trying to think the +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +term I've forgotten it so the uh but + + align:start position:0% +term I've forgotten it so the uh but + + + align:start position:0% +term I've forgotten it so the uh but +what I want to teach you today is for + + align:start position:0% +what I want to teach you today is for + + + align:start position:0% +what I want to teach you today is for +many many objects if you just look at + + align:start position:0% +many many objects if you just look at + + + align:start position:0% +many many objects if you just look at +their symmetries you can figure out by + + align:start position:0% +their symmetries you can figure out by + + + align:start position:0% +their symmetries you can figure out by +Common Sense where the principal axes + + align:start position:0% +Common Sense where the principal axes + + + align:start position:0% +Common Sense where the principal axes +are so that's what we're going to do + + align:start position:0% +are so that's what we're going to do + + + align:start position:0% +are so that's what we're going to do +next + + align:start position:0% + + + + align:start position:0% + +we started off saying that we're talking + + align:start position:0% +we started off saying that we're talking + + + align:start position:0% +we started off saying that we're talking +about bodies that are either rotating + + align:start position:0% +about bodies that are either rotating + + + align:start position:0% +about bodies that are either rotating +about their centers of mass or about + + align:start position:0% +about their centers of mass or about + + + align:start position:0% +about their centers of mass or about +some other fixed Point okay so we're now + + align:start position:0% +some other fixed Point okay so we're now + + + align:start position:0% +some other fixed Point okay so we're now +we're going to talk about we're going to + + align:start position:0% +we're going to talk about we're going to + + + align:start position:0% +we're going to talk about we're going to +Define our principal + + align:start position:0% +Define our principal + + + align:start position:0% +Define our principal +axis assuming we are rotating about the + + align:start position:0% +axis assuming we are rotating about the + + + align:start position:0% +axis assuming we are rotating about the +center of + + align:start position:0% +center of + + + align:start position:0% +center of +mass there's an easy easy method known + + align:start position:0% +mass there's an easy easy method known + + + align:start position:0% +mass there's an easy easy method known +as the parallel axis theorem to get any + + align:start position:0% +as the parallel axis theorem to get any + + + align:start position:0% +as the parallel axis theorem to get any +other point so why do we want to why do + + align:start position:0% +other point so why do we want to why do + + + align:start position:0% +other point so why do we want to why do +we care about doing it about the center + + align:start position:0% +we care about doing it about the center + + + align:start position:0% +we care about doing it about the center +of + + align:start position:0% + + + + align:start position:0% + +mass why is that useful to know about + + align:start position:0% +mass why is that useful to know about + + + align:start position:0% +mass why is that useful to know about +the properties around the center for + + align:start position:0% +the properties around the center for + + + align:start position:0% +the properties around the center for +Dynamics purposes what kind of Dynamics + + align:start position:0% +Dynamics purposes what kind of Dynamics + + + align:start position:0% +Dynamics purposes what kind of Dynamics +problems do you care about the center of + + align:start position:0% +problems do you care about the center of + + + align:start position:0% +problems do you care about the center of +mass rotation about the center of + + align:start position:0% + + + + align:start position:0% + +mass okay so when I throw this thing in + + align:start position:0% +mass okay so when I throw this thing in + + + align:start position:0% +mass okay so when I throw this thing in +the air it's rotating it's translating + + align:start position:0% +the air it's rotating it's translating + + + align:start position:0% +the air it's rotating it's translating +and when it rotates what's it rotating + + align:start position:0% +and when it rotates what's it rotating + + + align:start position:0% +and when it rotates what's it rotating +about Center Mass so there's just lots + + align:start position:0% +about Center Mass so there's just lots + + + align:start position:0% +about Center Mass so there's just lots +and lots of problems in which in fact + + align:start position:0% +and lots of problems in which in fact + + + align:start position:0% +and lots of problems in which in fact +the rotation is going to occur around + + align:start position:0% +the rotation is going to occur around + + + align:start position:0% +the rotation is going to occur around +the center Mass anytime the thing is off + + align:start position:0% +the center Mass anytime the thing is off + + + align:start position:0% +the center Mass anytime the thing is off +there and there's no uh nothing + + align:start position:0% +there and there's no uh nothing + + + align:start position:0% +there and there's no uh nothing +constraining its rotational motion the + + align:start position:0% +constraining its rotational motion the + + + align:start position:0% +constraining its rotational motion the +rotation will will be about the center + + align:start position:0% +rotation will will be about the center + + + align:start position:0% +rotation will will be about the center +of mass so that's a good that's a good + + align:start position:0% +of mass so that's a good that's a good + + + align:start position:0% +of mass so that's a good that's a good +enough reason the pract and a very + + align:start position:0% +enough reason the pract and a very + + + align:start position:0% +enough reason the pract and a very +practical then reason for computing + + align:start position:0% +practical then reason for computing + + + align:start position:0% +practical then reason for computing +these things or knowing how to find + + align:start position:0% +these things or knowing how to find + + + align:start position:0% +these things or knowing how to find +these things about the Center of mass + + align:start position:0% +these things about the Center of mass + + + align:start position:0% +these things about the Center of mass +all right so we're now we're going to do + + align:start position:0% +all right so we're now we're going to do + + + align:start position:0% +all right so we're now we're going to do +so we're doing principal + + align:start position:0% +so we're doing principal + + + align:start position:0% +so we're doing principal +axes + + align:start position:0% +axes + + + align:start position:0% +axes +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +and I'm going to teach you some symmetry + + align:start position:0% + + + + align:start position:0% + +rules maybe first a little Common + + align:start position:0% +rules maybe first a little Common + + + align:start position:0% +rules maybe first a little Common +Sense this thing is is this a principal + + align:start position:0% +Sense this thing is is this a principal + + + align:start position:0% +Sense this thing is is this a principal +axis no way right and we know for a fact + + align:start position:0% +axis no way right and we know for a fact + + + align:start position:0% +axis no way right and we know for a fact +that it doesn't have has off diagonal + + align:start position:0% +that it doesn't have has off diagonal + + + align:start position:0% +that it doesn't have has off diagonal +terms because I've defined my + + align:start position:0% +terms because I've defined my + + + align:start position:0% +terms because I've defined my +coordinates as being x y z like this and + + align:start position:0% +coordinates as being x y z like this and + + + align:start position:0% +coordinates as being x y z like this and +this is off at some strange angle so as + + align:start position:0% +this is off at some strange angle so as + + + align:start position:0% +this is off at some strange angle so as +a practical matter how could I make this + + align:start position:0% +a practical matter how could I make this + + + align:start position:0% +a practical matter how could I make this +the how could I make this object alter + + align:start position:0% +the how could I make this object alter + + + align:start position:0% +the how could I make this object alter +this object so that this is a principal + + align:start position:0% +this object so that this is a principal + + + align:start position:0% +this object so that this is a principal +axis it's essentially how would you + + align:start position:0% +axis it's essentially how would you + + + align:start position:0% +axis it's essentially how would you +balance + + align:start position:0% + + + + align:start position:0% + +this thatass off take the mass off that + + align:start position:0% +this thatass off take the mass off that + + + align:start position:0% +this thatass off take the mass off that +fix it okay + + align:start position:0% +fix it okay + + + align:start position:0% +fix it okay +or all + + align:start position:0% +or all + + + align:start position:0% +or all +right where put it down + + align:start position:0% + + + + align:start position:0% + +here now you want it like this all + + align:start position:0% + + + + align:start position:0% + +right this is steel going into + + align:start position:0% +right this is steel going into + + + align:start position:0% +right this is steel going into +aluminum I have to be careful that I + + align:start position:0% +aluminum I have to be careful that I + + + align:start position:0% +aluminum I have to be careful that I +don't strip the + + align:start position:0% + + + + align:start position:0% + +threads there we + + align:start position:0% + + + + align:start position:0% + +go all right and now test test one this + + align:start position:0% +go all right and now test test one this + + + align:start position:0% +go all right and now test test one this +is act rotation is a dynamically + + align:start position:0% +is act rotation is a dynamically + + + align:start position:0% +is act rotation is a dynamically +imbalance smooth as silk okay this now + + align:start position:0% +imbalance smooth as silk okay this now + + + align:start position:0% +imbalance smooth as silk okay this now +is a principal axis this thing has its + + align:start position:0% +is a principal axis this thing has its + + + align:start position:0% +is a principal axis this thing has its +mass distribution is + + align:start position:0% +mass distribution is + + + align:start position:0% +mass distribution is +symmetric and the plane of symmetry + + align:start position:0% +symmetric and the plane of symmetry + + + align:start position:0% +symmetric and the plane of symmetry +there's a plane where is there a plane + + align:start position:0% +there's a plane where is there a plane + + + align:start position:0% +there's a plane where is there a plane +of symmetry for this problem for this + + align:start position:0% +of symmetry for this problem for this + + + align:start position:0% +of symmetry for this problem for this +object so that's what we're going to + + align:start position:0% +object so that's what we're going to + + + align:start position:0% +object so that's what we're going to +talk about now planes of symmetry and + + align:start position:0% +talk about now planes of symmetry and + + + align:start position:0% +talk about now planes of symmetry and +axes of + + align:start position:0% +axes of + + + align:start position:0% +axes of +symmetry W you you see one like that + + align:start position:0% +symmetry W you you see one like that + + + align:start position:0% +symmetry W you you see one like that +you're right that's a PL of symmetry is + + align:start position:0% +you're right that's a PL of symmetry is + + + align:start position:0% +you're right that's a PL of symmetry is +there another one for this + + align:start position:0% + + + + align:start position:0% + +one like this so that's two planes of + + align:start position:0% +one like this so that's two planes of + + + align:start position:0% +one like this so that's two planes of +symmetry okay so let's let's let's come + + align:start position:0% +symmetry okay so let's let's let's come + + + align:start position:0% +symmetry okay so let's let's let's come +up with some rules for some symmetry + + align:start position:0% +up with some rules for some symmetry + + + align:start position:0% +up with some rules for some symmetry +rules + + align:start position:0% +rules + + + align:start position:0% +rules +um so this first one is there exists + + align:start position:0% + + + + align:start position:0% + +by this I mean diagonal it's a diagonal + + align:start position:0% +by this I mean diagonal it's a diagonal + + + align:start position:0% +by this I mean diagonal it's a diagonal +matrix you can find a set of orthogonal + + align:start position:0% +matrix you can find a set of orthogonal + + + align:start position:0% +matrix you can find a set of orthogonal +axes such that this Matrix is diagonal + + align:start position:0% +axes such that this Matrix is diagonal + + + align:start position:0% +axes such that this Matrix is diagonal +that's what we mean when we go to find + + align:start position:0% +that's what we mean when we go to find + + + align:start position:0% +that's what we mean when we go to find +principal axes + + align:start position:0% +principal axes + + + align:start position:0% +principal axes +okay um going to pick a board here + + align:start position:0% + + + + align:start position:0% + +rules and we're going to have three of + + align:start position:0% +rules and we're going to have three of + + + align:start position:0% +rules and we're going to have three of +them so just leave room on your paper + + align:start position:0% +them so just leave room on your paper + + + align:start position:0% +them so just leave room on your paper +we're going to build these up and I'm + + align:start position:0% +we're going to build these up and I'm + + + align:start position:0% +we're going to build these up and I'm +going to talk about it and then add + + align:start position:0% +going to talk about it and then add + + + align:start position:0% +going to talk about it and then add +another one and so forth + + align:start position:0% + + + + align:start position:0% + +okay so rule + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +yeah what the uh inertia matrix mean + + align:start position:0% +yeah what the uh inertia matrix mean + + + align:start position:0% +yeah what the uh inertia matrix mean +what is the inertia Matrix I mean the + + align:start position:0% +what is the inertia Matrix I mean the + + + align:start position:0% +what is the inertia Matrix I mean the +second one + + align:start position:0% +second one + + + align:start position:0% +second one +this thing with the diagonals this is + + align:start position:0% +this thing with the diagonals this is + + + align:start position:0% +this thing with the diagonals this is +going to have all the off diagonal terms + + align:start position:0% +going to have all the off diagonal terms + + + align:start position:0% +going to have all the off diagonal terms +are + + align:start position:0% + + + + align:start position:0% + +zeros that's what I mean it's a diagonal + + align:start position:0% +zeros that's what I mean it's a diagonal + + + align:start position:0% +zeros that's what I mean it's a diagonal +matrix there the mass moments of inertia + + align:start position:0% +matrix there the mass moments of inertia + + + align:start position:0% +matrix there the mass moments of inertia +and products of inertia you only have + + align:start position:0% +and products of inertia you only have + + + align:start position:0% +and products of inertia you only have +iixx i y y izz if you properly pick this + + align:start position:0% +iixx i y y izz if you properly pick this + + + align:start position:0% +iixx i y y izz if you properly pick this +set of orthogonal coordinates attached + + align:start position:0% +set of orthogonal coordinates attached + + + align:start position:0% +set of orthogonal coordinates attached +to the body if you pick them right what + + align:start position:0% +to the body if you pick them right what + + + align:start position:0% +to the body if you pick them right what +it means is you then you spin that + + align:start position:0% +it means is you then you spin that + + + align:start position:0% +it means is you then you spin that +object about one of those axes it's it + + align:start position:0% +object about one of those axes it's it + + + align:start position:0% +object about one of those axes it's it +it's it's + + align:start position:0% +it's it's + + + align:start position:0% +it's it's +inbalance okay so rule + + align:start position:0% +inbalance okay so rule + + + align:start position:0% +inbalance okay so rule +one so + + align:start position:0% + + + + align:start position:0% + +if there is an + + align:start position:0% +if there is an + + + align:start position:0% +if there is an +axis of symmetry + + align:start position:0% + + + + align:start position:0% + +okay remember the caveat here we're + + align:start position:0% +okay remember the caveat here we're + + + align:start position:0% +okay remember the caveat here we're +talking about uniform density objects or + + align:start position:0% +talking about uniform density objects or + + + align:start position:0% +talking about uniform density objects or +at least objects in which the density is + + align:start position:0% +at least objects in which the density is + + + align:start position:0% +at least objects in which the density is +symmetrically + + align:start position:0% +symmetrically + + + align:start position:0% +symmetrically +distributed all right so the geometric + + align:start position:0% +distributed all right so the geometric + + + align:start position:0% +distributed all right so the geometric +Symmetry and mass symmetry mean the same + + align:start position:0% +Symmetry and mass symmetry mean the same + + + align:start position:0% +Symmetry and mass symmetry mean the same +thing okay what's what does that mean so + + align:start position:0% +thing okay what's what does that mean so + + + align:start position:0% +thing okay what's what does that mean so +axis of + + align:start position:0% +axis of + + + align:start position:0% +axis of +symmetry + + align:start position:0% + + + + align:start position:0% + +um does this have an axis of + + align:start position:0% + + + + align:start position:0% + +symmetry + + align:start position:0% +symmetry + + + align:start position:0% +symmetry +where it has multiple ones down the + + align:start position:0% +where it has multiple ones down the + + + align:start position:0% +where it has multiple ones down the +middle that's a plane of symmetry the + + align:start position:0% +middle that's a plane of symmetry the + + + align:start position:0% +middle that's a plane of symmetry the +other ones you think so axis of symmetry + + align:start position:0% +other ones you think so axis of symmetry + + + align:start position:0% +other ones you think so axis of symmetry +line right which + + align:start position:0% +line right which + + + align:start position:0% +line right which +way + + align:start position:0% +way + + + align:start position:0% +way +no okay a AIS of symmetry means that you + + align:start position:0% +no okay a AIS of symmetry means that you + + + align:start position:0% +no okay a AIS of symmetry means that you +can you know there a mirror image from + + align:start position:0% +can you know there a mirror image from + + + align:start position:0% +can you know there a mirror image from +that point that point Mirror Image over + + align:start position:0% +that point that point Mirror Image over + + + align:start position:0% +that point that point Mirror Image over +here is always identical but you can + + align:start position:0% +here is always identical but you can + + + align:start position:0% +here is always identical but you can +pick it any from any angle doesn't + + align:start position:0% +pick it any from any angle doesn't + + + align:start position:0% +pick it any from any angle doesn't +matter where you start it's reflected + + align:start position:0% +matter where you start it's reflected + + + align:start position:0% +matter where you start it's reflected +through the axis so things that are + + align:start position:0% +through the axis so things that are + + + align:start position:0% +through the axis so things that are +circularly shape tend to have axes of + + align:start position:0% +circularly shape tend to have axes of + + + align:start position:0% +circularly shape tend to have axes of +symmetry so this has an axis of symmetry + + align:start position:0% +symmetry so this has an axis of symmetry + + + align:start position:0% +symmetry so this has an axis of symmetry +any everything is reflected exactly just + + align:start position:0% +any everything is reflected exactly just + + + align:start position:0% +any everything is reflected exactly just +across the axis you don't have to pick + + align:start position:0% +across the axis you don't have to pick + + + align:start position:0% +across the axis you don't have to pick +any particular line so for an axis of + + align:start position:0% +any particular line so for an axis of + + + align:start position:0% +any particular line so for an axis of +symmetry what it's saying if it's an + + align:start position:0% +symmetry what it's saying if it's an + + + align:start position:0% +symmetry what it's saying if it's an +axis of symmetry then it is a principal + + align:start position:0% +axis of symmetry then it is a principal + + + align:start position:0% +axis of symmetry then it is a principal +axis and rotation about that axis the + + align:start position:0% +axis and rotation about that axis the + + + align:start position:0% +axis and rotation about that axis the +thing will be nice perfectly inbalance + + align:start position:0% +thing will be nice perfectly inbalance + + + align:start position:0% +thing will be nice perfectly inbalance +if you go through all the hairy details + + align:start position:0% +if you go through all the hairy details + + + align:start position:0% +if you go through all the hairy details +of calculating uh the hard way the iixx + + align:start position:0% +of calculating uh the hard way the iixx + + + align:start position:0% +of calculating uh the hard way the iixx +i y y Etc terms all of the off diagonal + + align:start position:0% +i y y Etc terms all of the off diagonal + + + align:start position:0% +i y y Etc terms all of the off diagonal +terms will come out zero and the reason + + align:start position:0% +terms will come out zero and the reason + + + align:start position:0% +terms will come out zero and the reason +is that for every Mass particle over + + align:start position:0% +is that for every Mass particle over + + + align:start position:0% +is that for every Mass particle over +here let's say there's a little bit + + align:start position:0% +here let's say there's a little bit + + + align:start position:0% +here let's say there's a little bit +right here in the corner there is one + + align:start position:0% +right here in the corner there is one + + + align:start position:0% +right here in the corner there is one +exactly like it on the other side so if + + align:start position:0% +exactly like it on the other side so if + + + align:start position:0% +exactly like it on the other side so if +this one were're trying to make Bend + + align:start position:0% +this one were're trying to make Bend + + + align:start position:0% +this one were're trying to make Bend +this thing up as it spins around this + + align:start position:0% +this thing up as it spins around this + + + align:start position:0% +this thing up as it spins around this +one over here is telling it to come + + align:start position:0% +one over here is telling it to come + + + align:start position:0% +one over here is telling it to come +back yeah how come this is not an a like + + align:start position:0% +back yeah how come this is not an a like + + + align:start position:0% +back yeah how come this is not an a like +if you hold it yeah straight to the so + + align:start position:0% +if you hold it yeah straight to the so + + + align:start position:0% +if you hold it yeah straight to the so +to do this so I think it's kind of just + + align:start position:0% +to do this so I think it's kind of just + + + align:start position:0% +to do this so I think it's kind of just +definition we're getting into an axis of + + align:start position:0% +definition we're getting into an axis of + + + align:start position:0% +definition we're getting into an axis of +symmetry because the object in kind of + + align:start position:0% +symmetry because the object in kind of + + + align:start position:0% +symmetry because the object in kind of +simple terms the the what the object + + align:start position:0% +simple terms the the what the object + + + align:start position:0% +simple terms the the what the object +looks like this way it's it's a narrow + + align:start position:0% +looks like this way it's it's a narrow + + + align:start position:0% +looks like this way it's it's a narrow +object it is in fact uh a mirror image + + align:start position:0% +object it is in fact uh a mirror image + + + align:start position:0% +object it is in fact uh a mirror image +reflection but it looks different when + + align:start position:0% +reflection but it looks different when + + + align:start position:0% +reflection but it looks different when +you go to this angle and it looks + + align:start position:0% +you go to this angle and it looks + + + align:start position:0% +you go to this angle and it looks +different when you go to this angle so + + align:start position:0% +different when you go to this angle so + + + align:start position:0% +different when you go to this angle so +it's not an axis of symmetry that's a + + align:start position:0% +it's not an axis of symmetry that's a + + + align:start position:0% +it's not an axis of symmetry that's a +plane of symmetry and we're going to + + align:start position:0% +plane of symmetry and we're going to + + + align:start position:0% +plane of symmetry and we're going to +talk about that next so axes of symmetry + + align:start position:0% +talk about that next so axes of symmetry + + + align:start position:0% +talk about that next so axes of symmetry +the thing essentially looks the same at + + align:start position:0% +the thing essentially looks the same at + + + align:start position:0% +the thing essentially looks the same at +all orientations about that axis okay so + + align:start position:0% +all orientations about that axis okay so + + + align:start position:0% +all orientations about that axis okay so +but it is certainly it's dynamically + + align:start position:0% +but it is certainly it's dynamically + + + align:start position:0% +but it is certainly it's dynamically +balanced it it doesn't have every Mass + + align:start position:0% +balanced it it doesn't have every Mass + + + align:start position:0% +balanced it it doesn't have every Mass +bit here it balances one over there it + + align:start position:0% +bit here it balances one over there it + + + align:start position:0% +bit here it balances one over there it +doesn't wobble all right so that's a + + align:start position:0% +doesn't wobble all right so that's a + + + align:start position:0% +doesn't wobble all right so that's a +that's for sure true now keep in fact + + align:start position:0% +that's for sure true now keep in fact + + + align:start position:0% +that's for sure true now keep in fact +keep in + + align:start position:0% +keep in + + + align:start position:0% +keep in +mind that there exists an orthogonal a + + align:start position:0% +mind that there exists an orthogonal a + + + align:start position:0% +mind that there exists an orthogonal a +set of orthogonal + + align:start position:0% +set of orthogonal + + + align:start position:0% +set of orthogonal +axes so that means once you find one you + + align:start position:0% +axes so that means once you find one you + + + align:start position:0% +axes so that means once you find one you +know that the other two are + + align:start position:0% +know that the other two are + + + align:start position:0% +know that the other two are +perpendicular to it and perpendicular to + + align:start position:0% +perpendicular to it and perpendicular to + + + align:start position:0% +perpendicular to it and perpendicular to +each other so for this system what I've + + align:start position:0% +each other so for this system what I've + + + align:start position:0% +each other so for this system what I've +got X and Y here there has to be an X + + align:start position:0% +got X and Y here there has to be an X + + + align:start position:0% +got X and Y here there has to be an X +and Y perpendicular that that are the + + align:start position:0% +and Y perpendicular that that are the + + + align:start position:0% +and Y perpendicular that that are the +other + + align:start position:0% +other + + + align:start position:0% +other +two and for because it's actually + + align:start position:0% +two and for because it's actually + + + align:start position:0% +two and for because it's actually +symmetric then where you put them you + + align:start position:0% +symmetric then where you put them you + + + align:start position:0% +symmetric then where you put them you +could just say it's these two these two + + align:start position:0% +could just say it's these two these two + + + align:start position:0% +could just say it's these two these two +these two doesn't matter you just have + + align:start position:0% +these two doesn't matter you just have + + + align:start position:0% +these two doesn't matter you just have +to decide where you're going to put them + + align:start position:0% +to decide where you're going to put them + + + align:start position:0% +to decide where you're going to put them +on the object they're all the + + align:start position:0% +on the object they're all the + + + align:start position:0% +on the object they're all the +same okay so for + + align:start position:0% +same okay so for + + + align:start position:0% +same okay so for +uh this axis of symmetry there's just + + align:start position:0% +uh this axis of symmetry there's just + + + align:start position:0% +uh this axis of symmetry there's just +two more they're going to be in the body + + align:start position:0% +two more they're going to be in the body + + + align:start position:0% +two more they're going to be in the body +perpendicular to the first now we're + + align:start position:0% +perpendicular to the first now we're + + + align:start position:0% +perpendicular to the first now we're +going to do it about G + + align:start position:0% +going to do it about G + + + align:start position:0% +going to do it about G +so the book uses G to talk about as a + + align:start position:0% +so the book uses G to talk about as a + + + align:start position:0% +so the book uses G to talk about as a +cent Center Mass I'll use G so the + + align:start position:0% +cent Center Mass I'll use G so the + + + align:start position:0% +cent Center Mass I'll use G so the +center mass of this thing is is right in + + align:start position:0% +center mass of this thing is is right in + + + align:start position:0% +center mass of this thing is is right in +the middle of this and in the middle + + align:start position:0% +the middle of this and in the middle + + + align:start position:0% +the middle of this and in the middle +here so it's + + align:start position:0% +here so it's + + + align:start position:0% +here so it's +inside this body right in the dead + + align:start position:0% +inside this body right in the dead + + + align:start position:0% +inside this body right in the dead +center of it right okay so the pr + + align:start position:0% +center of it right okay so the pr + + + align:start position:0% +center of it right okay so the pr +principal axes are an orthogonal set one + + align:start position:0% +principal axes are an orthogonal set one + + + align:start position:0% +principal axes are an orthogonal set one +of which goes through it the other two + + align:start position:0% +of which goes through it the other two + + + align:start position:0% +of which goes through it the other two +are embedded in it at right angles so if + + align:start position:0% +are embedded in it at right angles so if + + + align:start position:0% +are embedded in it at right angles so if +you have this is the simplest rule if + + align:start position:0% +you have this is the simplest rule if + + + align:start position:0% +you have this is the simplest rule if +you have an axis of symmetry you know + + align:start position:0% +you have an axis of symmetry you know + + + align:start position:0% +you have an axis of symmetry you know +right away just about everything you + + align:start position:0% +right away just about everything you + + + align:start position:0% +right away just about everything you +need to know about the principal axes of + + align:start position:0% +need to know about the principal axes of + + + align:start position:0% +need to know about the principal axes of +the body um + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +shoot only symmetry in objects that are + + align:start position:0% +shoot only symmetry in objects that are + + + align:start position:0% +shoot only symmetry in objects that are +either round or spherical is that pretty + + align:start position:0% +either round or spherical is that pretty + + + align:start position:0% +either round or spherical is that pretty +much okay so it's very limited special + + align:start position:0% +much okay so it's very limited special + + + align:start position:0% +much okay so it's very limited special +case yeah but they sure appear an awful + + align:start position:0% +case yeah but they sure appear an awful + + + align:start position:0% +case yeah but they sure appear an awful +lot in machines because they have this + + align:start position:0% +lot in machines because they have this + + + align:start position:0% +lot in machines because they have this +beautiful property of just being + + align:start position:0% +beautiful property of just being + + + align:start position:0% +beautiful property of just being +balanced in all + + align:start position:0% +balanced in all + + + align:start position:0% +balanced in all +directions okay so everything rotating + + align:start position:0% +directions okay so everything rotating + + + align:start position:0% +directions okay so everything rotating +in the world tends to have almost + + align:start position:0% +in the world tends to have almost + + + align:start position:0% +in the world tends to have almost +perfect axial + + align:start position:0% +perfect axial + + + align:start position:0% +perfect axial +symmetry okay + + align:start position:0% +symmetry okay + + + align:start position:0% +symmetry okay +um just thinking about order here Let's + + align:start position:0% +um just thinking about order here Let's + + + align:start position:0% +um just thinking about order here Let's +do let's do this and then I'm going to + + align:start position:0% +do let's do this and then I'm going to + + + align:start position:0% +do let's do this and then I'm going to +go do a couple of examples the second + + align:start position:0% +go do a couple of examples the second + + + align:start position:0% +go do a couple of examples the second +rule if you have one + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +plane of + + align:start position:0% + + + + align:start position:0% + +symmetry okay what a plane of symmetry + + align:start position:0% +symmetry okay what a plane of symmetry + + + align:start position:0% +symmetry okay what a plane of symmetry +so this kind of the simp the opposite + + align:start position:0% +so this kind of the simp the opposite + + + align:start position:0% +so this kind of the simp the opposite +direction this you have the least + + align:start position:0% +direction this you have the least + + + align:start position:0% +direction this you have the least +information here's an object does it + + align:start position:0% +information here's an object does it + + + align:start position:0% +information here's an object does it +have a plane of + + align:start position:0% +have a plane of + + + align:start position:0% +have a plane of +symmetry where Straight middle show + + align:start position:0% +symmetry where Straight middle show + + + align:start position:0% +symmetry where Straight middle show +me that cut all right so I've got the + + align:start position:0% +me that cut all right so I've got the + + + align:start position:0% +me that cut all right so I've got the +little dotted marks on this thing so if + + align:start position:0% +little dotted marks on this thing so if + + + align:start position:0% +little dotted marks on this thing so if +I cut if I slice through that I create + + align:start position:0% +I cut if I slice through that I create + + + align:start position:0% +I cut if I slice through that I create +two pieces that are identical so that's + + align:start position:0% +two pieces that are identical so that's + + + align:start position:0% +two pieces that are identical so that's +a plane of symmetry there's image match + + align:start position:0% +a plane of symmetry there's image match + + + align:start position:0% +a plane of symmetry there's image match +across that plane at every Point + + align:start position:0% +across that plane at every Point + + + align:start position:0% +across that plane at every Point +okay so if I have a plane of symmetry + + align:start position:0% +okay so if I have a plane of symmetry + + + align:start position:0% +okay so if I have a plane of symmetry +what do you think you can say about a + + align:start position:0% +what do you think you can say about a + + + align:start position:0% +what do you think you can say about a +principal axis one of the principal axes + + align:start position:0% +principal axis one of the principal axes + + + align:start position:0% +principal axis one of the principal axes +it will be on that it'll be on that + + align:start position:0% +it will be on that it'll be on that + + + align:start position:0% +it will be on that it'll be on that +plane that turns out to be true but + + align:start position:0% +plane that turns out to be true but + + + align:start position:0% +plane that turns out to be true but +that's the second point I want to make + + align:start position:0% +that's the second point I want to make + + + align:start position:0% +that's the second point I want to make +it might be perpendicular she says it + + align:start position:0% +it might be perpendicular she says it + + + align:start position:0% +it might be perpendicular she says it +might be there might be one + + align:start position:0% +might be there might be one + + + align:start position:0% +might be there might be one +perpendicular to it and that's the one I + + align:start position:0% +perpendicular to it and that's the one I + + + align:start position:0% +perpendicular to it and that's the one I +was searching for you're right too okay + + align:start position:0% +was searching for you're right too okay + + + align:start position:0% +was searching for you're right too okay +there's going to be an axis a principal + + align:start position:0% +there's going to be an axis a principal + + + align:start position:0% +there's going to be an axis a principal +axis that's perpendicular to that plane + + align:start position:0% +axis that's perpendicular to that plane + + + align:start position:0% +axis that's perpendicular to that plane +of symmetry and since we want to Define + + align:start position:0% +of symmetry and since we want to Define + + + align:start position:0% +of symmetry and since we want to Define +our moments of inertia for this to start + + align:start position:0% +our moments of inertia for this to start + + + align:start position:0% +our moments of inertia for this to start +with with respect to G where will it + + align:start position:0% +with with respect to G where will it + + + align:start position:0% +with with respect to G where will it +pass through g g okay kind of by + + align:start position:0% +pass through g g okay kind of by + + + align:start position:0% +pass through g g okay kind of by +definition so we're going to have it + + align:start position:0% +definition so we're going to have it + + + align:start position:0% +definition so we're going to have it +pass through G if there's a plane of + + align:start position:0% +pass through G if there's a plane of + + + align:start position:0% +pass through G if there's a plane of +symmetry + + align:start position:0% +symmetry + + + align:start position:0% +symmetry +uh then + + align:start position:0% + + + + align:start position:0% + +there is + + align:start position:0% + + + + align:start position:0% + +a principal + + align:start position:0% + + + + align:start position:0% + +axis perpendicular to + + align:start position:0% + + + + align:start position:0% + +it and we'll Define it for the purposes + + align:start position:0% +it and we'll Define it for the purposes + + + align:start position:0% +it and we'll Define it for the purposes +of our discussion + + align:start position:0% +of our discussion + + + align:start position:0% +of our discussion +we'll we'll just let it pass through G + + align:start position:0% + + + + align:start position:0% + +so doesn't have to but that's how we're + + align:start position:0% +so doesn't have to but that's how we're + + + align:start position:0% +so doesn't have to but that's how we're +going about this discussion let it pass + + align:start position:0% +going about this discussion let it pass + + + align:start position:0% +going about this discussion let it pass +through the center of mass this point we + + align:start position:0% +through the center of mass this point we + + + align:start position:0% +through the center of mass this point we +call + + align:start position:0% +call + + + align:start position:0% +call +G all right all right so that means that + + align:start position:0% +G all right all right so that means that + + + align:start position:0% +G all right all right so that means that +there's a point there's a center there's + + align:start position:0% +there's a point there's a center there's + + + align:start position:0% +there's a point there's a center there's +a center of mass in this + + align:start position:0% +a center of mass in this + + + align:start position:0% +a center of mass in this +thing and I'm just guessing roughly + + align:start position:0% +thing and I'm just guessing roughly + + + align:start position:0% +thing and I'm just guessing roughly +where it is but in fact you know if I + + align:start position:0% +where it is but in fact you know if I + + + align:start position:0% +where it is but in fact you know if I +hung this thing up here like this + + align:start position:0% +hung this thing up here like this + + + align:start position:0% +hung this thing up here like this +and let gravity find its find its uh + + align:start position:0% +and let gravity find its find its uh + + + align:start position:0% +and let gravity find its find its uh +natural hanging angle and I drew a plum + + align:start position:0% +natural hanging angle and I drew a plum + + + align:start position:0% +natural hanging angle and I drew a plum +line down here and just drew a line + + align:start position:0% +line down here and just drew a line + + + align:start position:0% +line down here and just drew a line +that's the that that the string would + + align:start position:0% +that's the that that the string would + + + align:start position:0% +that's the that that the string would +take with a plum Bob then I went to some + + align:start position:0% +take with a plum Bob then I went to some + + + align:start position:0% +take with a plum Bob then I went to some +other point and did it again and hung a + + align:start position:0% +other point and did it again and hung a + + + align:start position:0% +other point and did it again and hung a +plum Bob on it and Drew the line where + + align:start position:0% +plum Bob on it and Drew the line where + + + align:start position:0% +plum Bob on it and Drew the line where +the intersect is Center of mass okay + + align:start position:0% +the intersect is Center of mass okay + + + align:start position:0% +the intersect is Center of mass okay +then you know since it's got symmetry + + align:start position:0% +then you know since it's got symmetry + + + align:start position:0% +then you know since it's got symmetry +this way that it's in the middle so I + + align:start position:0% +this way that it's in the middle so I + + + align:start position:0% +this way that it's in the middle so I +guessed that that's about where it is + + align:start position:0% +guessed that that's about where it is + + + align:start position:0% +guessed that that's about where it is +and there then is a a principal axis of + + align:start position:0% +and there then is a a principal axis of + + + align:start position:0% +and there then is a a principal axis of +this object that passes that's + + align:start position:0% +this object that passes that's + + + align:start position:0% +this object that passes that's +perpendicular to it P passing through + + align:start position:0% +perpendicular to it P passing through + + + align:start position:0% +perpendicular to it P passing through +the plane perpendicular to the plane and + + align:start position:0% +the plane perpendicular to the plane and + + + align:start position:0% +the plane perpendicular to the plane and +that means now there's two more that + + align:start position:0% +that means now there's two more that + + + align:start position:0% +that means now there's two more that +this gets a little more difficult and I + + align:start position:0% +this gets a little more difficult and I + + + align:start position:0% +this gets a little more difficult and I +I don't I have no + + align:start position:0% +I don't I have no + + + align:start position:0% +I don't I have no +clue there are two more because the + + align:start position:0% +clue there are two more because the + + + align:start position:0% +clue there are two more because the +principal axes are always coming in + + align:start position:0% +principal axes are always coming in + + + align:start position:0% +principal axes are always coming in +orthogonal set so now that I know one I + + align:start position:0% +orthogonal set so now that I know one I + + + align:start position:0% +orthogonal set so now that I know one I +know that there's two more + + align:start position:0% +know that there's two more + + + align:start position:0% +know that there's two more +somewhere around mounted you know + + align:start position:0% +somewhere around mounted you know + + + align:start position:0% +somewhere around mounted you know +oriented with this way someplace in this + + align:start position:0% +oriented with this way someplace in this + + + align:start position:0% +oriented with this way someplace in this +plane you know maybe one like that maybe + + align:start position:0% +plane you know maybe one like that maybe + + + align:start position:0% +plane you know maybe one like that maybe +one like like this such that if you spun + + align:start position:0% +one like like this such that if you spun + + + align:start position:0% +one like like this such that if you spun +it about one of those axes it would be + + align:start position:0% +it about one of those axes it would be + + + align:start position:0% +it about one of those axes it would be +inbalance and you can see that gets a + + align:start position:0% +inbalance and you can see that gets a + + + align:start position:0% +inbalance and you can see that gets a +little messy I can't guess where it + + align:start position:0% +little messy I can't guess where it + + + align:start position:0% +little messy I can't guess where it +is and so there are ways to find it one + + align:start position:0% +is and so there are ways to find it one + + + align:start position:0% +is and so there are ways to find it one +of them would be doing an experiment + + align:start position:0% +of them would be doing an experiment + + + align:start position:0% +of them would be doing an experiment +seeing which axis it spins nicely around + + align:start position:0% +seeing which axis it spins nicely around + + + align:start position:0% +seeing which axis it spins nicely around +so that's the second + + align:start position:0% + + + + align:start position:0% + +rule but even just with that one plane + + align:start position:0% +rule but even just with that one plane + + + align:start position:0% +rule but even just with that one plane +of symmetry that's you you get some + + align:start position:0% +of symmetry that's you you get some + + + align:start position:0% +of symmetry that's you you get some +pretty good Insight okay now what if + + align:start position:0% +pretty good Insight okay now what if + + + align:start position:0% +pretty good Insight okay now what if +there are two planes of symmetry + + align:start position:0% +there are two planes of symmetry + + + align:start position:0% +there are two planes of symmetry +yeah um you said that your principal + + align:start position:0% +yeah um you said that your principal + + + align:start position:0% +yeah um you said that your principal +access does not have to pass through the + + align:start position:0% +access does not have to pass through the + + + align:start position:0% +access does not have to pass through the +center of mass no we're she asked about + + align:start position:0% +center of mass no we're she asked about + + + align:start position:0% +center of mass no we're she asked about +about I'm saying it doesn't have to pass + + align:start position:0% +about I'm saying it doesn't have to pass + + + align:start position:0% +about I'm saying it doesn't have to pass +through the center of mass the question + + align:start position:0% +through the center of mass the question + + + align:start position:0% +through the center of mass the question +is um how could it not because it' be + + align:start position:0% +is um how could it not because it' be + + + align:start position:0% +is um how could it not because it' be +unstable so she's saying it'd be + + align:start position:0% +unstable so she's saying it'd be + + + align:start position:0% +unstable so she's saying it'd be +unstable if it's not passing through + + align:start position:0% +unstable if it's not passing through + + + align:start position:0% +unstable if it's not passing through +there like if I put an axle through this + + align:start position:0% +there like if I put an axle through this + + + align:start position:0% +there like if I put an axle through this +wheel and I spun it about some point out + + align:start position:0% +wheel and I spun it about some point out + + + align:start position:0% +wheel and I spun it about some point out +here we you know cuz I had that Shaker + + align:start position:0% +here we you know cuz I had that Shaker + + + align:start position:0% +here we you know cuz I had that Shaker +in here that thing is going to shake + + align:start position:0% +in here that thing is going to shake + + + align:start position:0% +in here that thing is going to shake +like crazy right but it does it produce + + align:start position:0% +like crazy right but it does it produce + + + align:start position:0% +like crazy right but it does it produce +unbalance torqus about my rotation + + align:start position:0% +unbalance torqus about my rotation + + + align:start position:0% +unbalance torqus about my rotation +Point it'll produce a centrifugal force + + align:start position:0% +Point it'll produce a centrifugal force + + + align:start position:0% +Point it'll produce a centrifugal force +that you'll feel like crazy but does it + + align:start position:0% +that you'll feel like crazy but does it + + + align:start position:0% +that you'll feel like crazy but does it +produce a torque trying to that you'd + + align:start position:0% +produce a torque trying to that you'd + + + align:start position:0% +produce a torque trying to that you'd +have to resist with some static + + align:start position:0% +have to resist with some static + + + align:start position:0% +have to resist with some static +torque what do you + + align:start position:0% +torque what do you + + + align:start position:0% +torque what do you +think it won't so there's a new one to + + align:start position:0% +think it won't so there's a new one to + + + align:start position:0% +think it won't so there's a new one to +this unbalanced thing and I was going to + + align:start position:0% +this unbalanced thing and I was going to + + + align:start position:0% +this unbalanced thing and I was going to +get to it probably next lecture but and + + align:start position:0% +get to it probably next lecture but and + + + align:start position:0% +get to it probably next lecture but and +that is that when we say an object is + + align:start position:0% +that is that when we say an object is + + + align:start position:0% +that is that when we say an object is +dynamically balanced we mean that it + + align:start position:0% +dynamically balanced we mean that it + + + align:start position:0% +dynamically balanced we mean that it +doesn't have any unbalanced + + align:start position:0% +doesn't have any unbalanced + + + align:start position:0% +doesn't have any unbalanced +torqus if we if it is statically + + align:start position:0% +torqus if we if it is statically + + + align:start position:0% +torqus if we if it is statically +balanced it + + align:start position:0% +balanced it + + + align:start position:0% +balanced it +doesn't it's rotating about its Center + + align:start position:0% +doesn't it's rotating about its Center + + + align:start position:0% +doesn't it's rotating about its Center +of mass but you can be statically + + align:start position:0% +of mass but you can be statically + + + align:start position:0% +of mass but you can be statically +unbalanced and let it go around this + + align:start position:0% +unbalanced and let it go around this + + + align:start position:0% +unbalanced and let it go around this +axis + + align:start position:0% +axis + + + align:start position:0% +axis +but it'll produce no torqus it's still + + align:start position:0% +but it'll produce no torqus it's still + + + align:start position:0% +but it'll produce no torqus it's still +dynamically balanced and the angular + + align:start position:0% +dynamically balanced and the angular + + + align:start position:0% +dynamically balanced and the angular +momentum of an object which is + + align:start position:0% + + + + align:start position:0% + +rotating this we know has a principal + + align:start position:0% +rotating this we know has a principal + + + align:start position:0% +rotating this we know has a principal +axis here I just moved it off to the + + align:start position:0% +axis here I just moved it off to the + + + align:start position:0% +axis here I just moved it off to the +side it's rotating about + + align:start position:0% +side it's rotating about + + + align:start position:0% +side it's rotating about +this um it is dynamically balanced and + + align:start position:0% +this um it is dynamically balanced and + + + align:start position:0% +this um it is dynamically balanced and +if you computed the off D about this + + align:start position:0% +if you computed the off D about this + + + align:start position:0% +if you computed the off D about this +point now the IX y ixz off + + align:start position:0% +point now the IX y ixz off + + + align:start position:0% +point now the IX y ixz off +diagonal entries in that moment of + + align:start position:0% +diagonal entries in that moment of + + + align:start position:0% +diagonal entries in that moment of +inertia Matrix they're all + + align:start position:0% +inertia Matrix they're all + + + align:start position:0% +inertia Matrix they're all +zero you'd get no Tor no unbalanced + + align:start position:0% +zero you'd get no Tor no unbalanced + + + align:start position:0% +zero you'd get no Tor no unbalanced +torqu but you do have an unbalanced + + align:start position:0% +torqu but you do have an unbalanced + + + align:start position:0% +torqu but you do have an unbalanced +centrifugal force as this thing goes + + align:start position:0% +centrifugal force as this thing goes + + + align:start position:0% +centrifugal force as this thing goes +around we'll talk a little bit more is + + align:start position:0% +around we'll talk a little bit more is + + + align:start position:0% +around we'll talk a little bit more is +that sort of analogous to the homework + + align:start position:0% +that sort of analogous to the homework + + + align:start position:0% +that sort of analogous to the homework +problem we had if you keep this back + + align:start position:0% +problem we had if you keep this back + + + align:start position:0% +problem we had if you keep this back +with the um motorcycle wheel and you + + align:start position:0% +with the um motorcycle wheel and you + + + align:start position:0% +with the um motorcycle wheel and you +just had a MTH on one + + align:start position:0% +just had a MTH on one + + + align:start position:0% +just had a MTH on one +side right so she's asking about the + + align:start position:0% +side right so she's asking about the + + + align:start position:0% +side right so she's asking about the +motorcycle wheel problem where we had + + align:start position:0% +motorcycle wheel problem where we had + + + align:start position:0% +motorcycle wheel problem where we had +that little Mass stuck out there I think + + align:start position:0% +that little Mass stuck out there I think + + + align:start position:0% +that little Mass stuck out there I think +in the next lecture I'm going to bring + + align:start position:0% +in the next lecture I'm going to bring + + + align:start position:0% +in the next lecture I'm going to bring +I'm going to come back to that problem + + align:start position:0% +I'm going to come back to that problem + + + align:start position:0% +I'm going to come back to that problem +just so that we can tie a bow around + + align:start position:0% +just so that we can tie a bow around + + + align:start position:0% +just so that we can tie a bow around +this whole thing and understand how uh + + align:start position:0% +this whole thing and understand how uh + + + align:start position:0% +this whole thing and understand how uh +how you why it's unbalanced how you can + + align:start position:0% +how you why it's unbalanced how you can + + + align:start position:0% +how you why it's unbalanced how you can +balance it and the difference between + + align:start position:0% +balance it and the difference between + + + align:start position:0% +balance it and the difference between +static unbalance and dynamic unbalance + + align:start position:0% +static unbalance and dynamic unbalance + + + align:start position:0% +static unbalance and dynamic unbalance +but today we're talking about symmetry + + align:start position:0% +but today we're talking about symmetry + + + align:start position:0% +but today we're talking about symmetry +rules + + align:start position:0% +rules + + + align:start position:0% +rules +okay finally so I was saying let's talk + + align:start position:0% +okay finally so I was saying let's talk + + + align:start position:0% +okay finally so I was saying let's talk +about something that has two planes of + + align:start position:0% +about something that has two planes of + + + align:start position:0% +about something that has two planes of +symmetry this actually has three ples of + + align:start position:0% +symmetry this actually has three ples of + + + align:start position:0% +symmetry this actually has three ples of +symmetry but we'll settle for two + + align:start position:0% + + + + align:start position:0% + +plane of where where's a where's pick + + align:start position:0% +plane of where where's a where's pick + + + align:start position:0% +plane of where where's a where's pick +pick a plane of symmetry for this object + + align:start position:0% +pick a plane of symmetry for this object + + + align:start position:0% +pick a plane of symmetry for this object +if I okay she picks the one slice it + + align:start position:0% +if I okay she picks the one slice it + + + align:start position:0% +if I okay she picks the one slice it +this way all right that's a plan of + + align:start position:0% +this way all right that's a plan of + + + align:start position:0% +this way all right that's a plan of +symmetry do I have do I have a + + align:start position:0% + + + + align:start position:0% + +second like that okay and a third right + + align:start position:0% +second like that okay and a third right + + + align:start position:0% +second like that okay and a third right +there's even one like that so this has + + align:start position:0% +there's even one like that so this has + + + align:start position:0% +there's even one like that so this has +three planes of symmetry but if you have + + align:start position:0% +three planes of symmetry but if you have + + + align:start position:0% +three planes of symmetry but if you have +two planes of + + align:start position:0% +two planes of + + + align:start position:0% +two planes of +symmetry that + + align:start position:0% + + + + align:start position:0% + +intersect that are orthogonal to one + + align:start position:0% +intersect that are orthogonal to one + + + align:start position:0% +intersect that are orthogonal to one +another + + align:start position:0% + + + + align:start position:0% + +what do you think you can say about that + + align:start position:0% +what do you think you can say about that + + + align:start position:0% +what do you think you can say about that +line of + + align:start position:0% + + + + align:start position:0% + +intersection you and it it sure is and + + align:start position:0% +intersection you and it it sure is and + + + align:start position:0% +intersection you and it it sure is and +it's probably right through + + align:start position:0% +it's probably right through + + + align:start position:0% +it's probably right through +G okay so if you have two uh planes of + + align:start position:0% +G okay so if you have two uh planes of + + + align:start position:0% +G okay so if you have two uh planes of +symmetry + + align:start position:0% + + + + align:start position:0% + +and I'll make them orthogonal you can + + align:start position:0% +and I'll make them orthogonal you can + + + align:start position:0% +and I'll make them orthogonal you can +make all sorts of symmetry rules and I'm + + align:start position:0% +make all sorts of symmetry rules and I'm + + + align:start position:0% +make all sorts of symmetry rules and I'm +just picking these three to make to to + + align:start position:0% +just picking these three to make to to + + + align:start position:0% +just picking these three to make to to +help you out this just to help you see + + align:start position:0% +help you out this just to help you see + + + align:start position:0% +help you out this just to help you see +uh principal axes if you have two + + align:start position:0% +uh principal axes if you have two + + + align:start position:0% +uh principal axes if you have two +orthogonal + + align:start position:0% + + + + align:start position:0% + +planes of + + align:start position:0% + + + + align:start position:0% + +symmetry + + align:start position:0% +symmetry + + + align:start position:0% +symmetry +their intersection + + align:start position:0% + + + + align:start position:0% + +and once you know + + align:start position:0% +and once you know + + + align:start position:0% +and once you know +that then you go back to rule two and it + + align:start position:0% +that then you go back to rule two and it + + + align:start position:0% +that then you go back to rule two and it +tells you everything else you need to + + align:start position:0% +tells you everything else you need to + + + align:start position:0% +tells you everything else you need to +know because you have one plan of + + align:start position:0% +know because you have one plan of + + + align:start position:0% +know because you have one plan of +symmetry you know that there is an a + + align:start position:0% +symmetry you know that there is an a + + + align:start position:0% +symmetry you know that there is an a +principal + + align:start position:0% +principal + + + align:start position:0% +principal +axis perpendicular to it well if you + + align:start position:0% +axis perpendicular to it well if you + + + align:start position:0% +axis perpendicular to it well if you +have two planes of symmetry rules still + + align:start position:0% +have two planes of symmetry rules still + + + align:start position:0% +have two planes of symmetry rules still +hold there's one perpendicular to each + + align:start position:0% +hold there's one perpendicular to each + + + align:start position:0% +hold there's one perpendicular to each +one the intersection let's say of this + + align:start position:0% +one the intersection let's say of this + + + align:start position:0% +one the intersection let's say of this +plane of symmetry and this plane of + + align:start position:0% +plane of symmetry and this plane of + + + align:start position:0% +plane of symmetry and this plane of +symmetry is a line which goes right + + align:start position:0% +symmetry is a line which goes right + + + align:start position:0% +symmetry is a line which goes right +through dead through the center of this + + align:start position:0% +through dead through the center of this + + + align:start position:0% +through dead through the center of this +thing that way so there's a principal + + align:start position:0% +thing that way so there's a principal + + + align:start position:0% +thing that way so there's a principal +axis this way but since there is a plane + + align:start position:0% +axis this way but since there is a plane + + + align:start position:0% +axis this way but since there is a plane +of symmetry here there must also be a + + align:start position:0% +of symmetry here there must also be a + + + align:start position:0% +of symmetry here there must also be a +principal axis perpendicular to it so + + align:start position:0% +principal axis perpendicular to it so + + + align:start position:0% +principal axis perpendicular to it so +sure enough The three principal axes for + + align:start position:0% +sure enough The three principal axes for + + + align:start position:0% +sure enough The three principal axes for +this thing are through the + + align:start position:0% +this thing are through the + + + align:start position:0% +this thing are through the +center per perpendicular this way + + align:start position:0% +center per perpendicular this way + + + align:start position:0% +center per perpendicular this way +perpendicular that way you instantly + + align:start position:0% +perpendicular that way you instantly + + + align:start position:0% +perpendicular that way you instantly +know two planes of symmetry you + + align:start position:0% +know two planes of symmetry you + + + align:start position:0% +know two planes of symmetry you +instantly know where the three + + align:start position:0% +instantly know where the three + + + align:start position:0% +instantly know where the three +orthogonal principal axes are that pass + + align:start position:0% +orthogonal principal axes are that pass + + + align:start position:0% +orthogonal principal axes are that pass +through the center of mass okay + + align:start position:0% +through the center of mass okay + + + align:start position:0% +through the center of mass okay +yeah constant Mass not + + align:start position:0% +yeah constant Mass not + + + align:start position:0% +yeah constant Mass not +constant symmetrically I symmetrically + + align:start position:0% +constant symmetrically I symmetrically + + + align:start position:0% +constant symmetrically I symmetrically +distributed + + align:start position:0% +distributed + + + align:start position:0% +distributed +density all right so I want what I'm + + align:start position:0% +density all right so I want what I'm + + + align:start position:0% +density all right so I want what I'm +trying to I'm choosing my words + + align:start position:0% +trying to I'm choosing my words + + + align:start position:0% +trying to I'm choosing my words +carefully so that I succeed in the + + align:start position:0% +carefully so that I succeed in the + + + align:start position:0% +carefully so that I succeed in the +following that the planes defining Mass + + align:start position:0% +following that the planes defining Mass + + + align:start position:0% +following that the planes defining Mass +symmetry will be the same as the planes + + align:start position:0% +symmetry will be the same as the planes + + + align:start position:0% +symmetry will be the same as the planes +defining geometric similarity but you + + align:start position:0% +defining geometric similarity but you + + + align:start position:0% +defining geometric similarity but you +actually don't have to have constant + + align:start position:0% +actually don't have to have constant + + + align:start position:0% +actually don't have to have constant +density it just has to be distributed so + + align:start position:0% +density it just has to be distributed so + + + align:start position:0% +density it just has to be distributed so +that what I just said is true so that + + align:start position:0% +that what I just said is true so that + + + align:start position:0% +that what I just said is true so that +the geometric symmetries are the same as + + align:start position:0% +the geometric symmetries are the same as + + + align:start position:0% +the geometric symmetries are the same as +the mass distribution + + align:start position:0% +the mass distribution + + + align:start position:0% +the mass distribution +symmetries all right so those are my + + align:start position:0% +symmetries all right so those are my + + + align:start position:0% +symmetries all right so those are my +three rules of symmetry you could make + + align:start position:0% +three rules of symmetry you could make + + + align:start position:0% +three rules of symmetry you could make +up others those are three that I've made + + align:start position:0% +up others those are three that I've made + + + align:start position:0% +up others those are three that I've made +up to help you see objects um okay + + align:start position:0% + + + + align:start position:0% + +that object it's a circular + + align:start position:0% +that object it's a circular + + + align:start position:0% +that object it's a circular +disc put on top of + + align:start position:0% + + + + align:start position:0% + +a of another object such their CG their + + align:start position:0% +a of another object such their CG their + + + align:start position:0% +a of another object such their CG their +centers of mass + + align:start position:0% +centers of mass + + + align:start position:0% +centers of mass +lineup where are the principal axes of + + align:start position:0% +lineup where are the principal axes of + + + align:start position:0% +lineup where are the principal axes of +this + + align:start position:0% +this + + + align:start position:0% +this +object using those + + align:start position:0% + + + + align:start position:0% + +rules you think you know one tell me + + align:start position:0% + + + + align:start position:0% + +M all right dead through the middle of + + align:start position:0% +M all right dead through the middle of + + + align:start position:0% +M all right dead through the middle of +both of them all right probably it's + + align:start position:0% +both of them all right probably it's + + + align:start position:0% +both of them all right probably it's +good guess how about another + + align:start position:0% + + + + align:start position:0% + +one mean where are there planes where + + align:start position:0% +one mean where are there planes where + + + align:start position:0% +one mean where are there planes where +does this thing at planes of + + align:start position:0% +does this thing at planes of + + + align:start position:0% +does this thing at planes of +symmetry so there's a plan of symmetry + + align:start position:0% +symmetry so there's a plan of symmetry + + + align:start position:0% +symmetry so there's a plan of symmetry +cut half access if you cut + + align:start position:0% +cut half access if you cut + + + align:start position:0% +cut half access if you cut +half okay and + + align:start position:0% + + + + align:start position:0% + +and one like that we just we've got all + + align:start position:0% +and one like that we just we've got all + + + align:start position:0% +and one like that we just we've got all +three but and if we're going to want it + + align:start position:0% +three but and if we're going to want it + + + align:start position:0% +three but and if we're going to want it +to go through the center of mass and + + align:start position:0% +to go through the center of mass and + + + align:start position:0% +to go through the center of mass and +we're going to have to find where the + + align:start position:0% +we're going to have to find where the + + + align:start position:0% +we're going to have to find where the +center of mass is this way but it's you + + align:start position:0% +center of mass is this way but it's you + + + align:start position:0% +center of mass is this way but it's you +know about there let's say okay so just + + align:start position:0% +know about there let's say okay so just + + + align:start position:0% +know about there let's say okay so just +using these symmetry ideas you can write + + align:start position:0% +using these symmetry ideas you can write + + + align:start position:0% +using these symmetry ideas you can write +away figure out where these principal + + align:start position:0% +away figure out where these principal + + + align:start position:0% +away figure out where these principal +axes be and that means that from a + + align:start position:0% +axes be and that means that from a + + + align:start position:0% +axes be and that means that from a +dynamic point of view if you spin it + + align:start position:0% +dynamic point of view if you spin it + + + align:start position:0% +dynamic point of view if you spin it +about one of those ax axes it's nice and + + align:start position:0% +about one of those ax axes it's nice and + + + align:start position:0% +about one of those ax axes it's nice and +dynamically balanced if you spin it off + + align:start position:0% +dynamically balanced if you spin it off + + + align:start position:0% +dynamically balanced if you spin it off +in some other weird direction is it + + align:start position:0% +in some other weird direction is it + + + align:start position:0% +in some other weird direction is it +necessar thly dynamically balanced about + + align:start position:0% +necessar thly dynamically balanced about + + + align:start position:0% +necessar thly dynamically balanced about +that axis of + + align:start position:0% + + + + align:start position:0% + +spin so let me restate that + + align:start position:0% +spin so let me restate that + + + align:start position:0% +spin so let me restate that +question + + align:start position:0% + + + + align:start position:0% + +um we know that this thing has an axis + + align:start position:0% +um we know that this thing has an axis + + + align:start position:0% +um we know that this thing has an axis +of symmetry a principal axis through the + + align:start position:0% +of symmetry a principal axis through the + + + align:start position:0% +of symmetry a principal axis through the +center there another one this way and + + align:start position:0% +center there another one this way and + + + align:start position:0% +center there another one this way and +another one this way and if I spin it + + align:start position:0% +another one this way and if I spin it + + + align:start position:0% +another one this way and if I spin it +about any one of those it's dynamically + + align:start position:0% +about any one of those it's dynamically + + + align:start position:0% +about any one of those it's dynamically +balanced but if I pick some other + + align:start position:0% +balanced but if I pick some other + + + align:start position:0% +balanced but if I pick some other +strange direction for the spin and I + + align:start position:0% +strange direction for the spin and I + + + align:start position:0% +strange direction for the spin and I +spin it about that axis will I feel + + align:start position:0% +spin it about that axis will I feel + + + align:start position:0% +spin it about that axis will I feel +unbalanced torqus on this axle on the + + align:start position:0% +unbalanced torqus on this axle on the + + + align:start position:0% +unbalanced torqus on this axle on the +bearings having to hold this thing in + + align:start position:0% +bearings having to hold this thing in + + + align:start position:0% +bearings having to hold this thing in +place yeah you better believe it this + + align:start position:0% +place yeah you better believe it this + + + align:start position:0% +place yeah you better believe it this +thing wobbles like crazy so the + + align:start position:0% +thing wobbles like crazy so the + + + align:start position:0% +thing wobbles like crazy so the +fact the principal axes are a property + + align:start position:0% +fact the principal axes are a property + + + align:start position:0% +fact the principal axes are a property +of the + + align:start position:0% +of the + + + align:start position:0% +of the +object they're not a property of the + + align:start position:0% +object they're not a property of the + + + align:start position:0% +object they're not a property of the +angular momentum the angular momentum + + align:start position:0% +angular momentum the angular momentum + + + align:start position:0% +angular momentum the angular momentum +comes then from + + align:start position:0% +comes then from + + + align:start position:0% +comes then from +multiplying the mass moment of inertia + + align:start position:0% +multiplying the mass moment of inertia + + + align:start position:0% +multiplying the mass moment of inertia +that you've determined + + align:start position:0% +that you've determined + + + align:start position:0% +that you've determined +times the actual rotation vector and + + align:start position:0% +times the actual rotation vector and + + + align:start position:0% +times the actual rotation vector and +you'll find out that you get uh angular + + align:start position:0% +you'll find out that you get uh angular + + + align:start position:0% +you'll find out that you get uh angular +components of angular momentum that are + + align:start position:0% +components of angular momentum that are + + + align:start position:0% +components of angular momentum that are +not in the direction of spin as soon as + + align:start position:0% +not in the direction of spin as soon as + + + align:start position:0% +not in the direction of spin as soon as +that happens you have unbalanced + + align:start position:0% +that happens you have unbalanced + + + align:start position:0% +that happens you have unbalanced +terms okay + + align:start position:0% +terms okay + + + align:start position:0% +terms okay +um I got to get on to something else + + align:start position:0% +um I got to get on to something else + + + align:start position:0% +um I got to get on to something else +before to help you do homework let's um + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so for my + + align:start position:0% + + + + align:start position:0% + +dis with Z coming out of the + + align:start position:0% +dis with Z coming out of the + + + align:start position:0% +dis with Z coming out of the +board the izz so let's say here's x y z + + align:start position:0% +board the izz so let's say here's x y z + + + align:start position:0% +board the izz so let's say here's x y z +coming out of the board izz the mass + + align:start position:0% +coming out of the board izz the mass + + + align:start position:0% +coming out of the board izz the mass +dist Mass moment of inertia of about + + align:start position:0% +dist Mass moment of inertia of about + + + align:start position:0% +dist Mass moment of inertia of about +this + + align:start position:0% +this + + + align:start position:0% +this +z-axis + + align:start position:0% +z-axis + + + align:start position:0% +z-axis +is from the basic definition the + + align:start position:0% +is from the basic definition the + + + align:start position:0% +is from the basic definition the +summation of the + + align:start position:0% +summation of the + + + align:start position:0% +summation of the +m x i 2 plus uh y i 2 it's just that for + + align:start position:0% +m x i 2 plus uh y i 2 it's just that for + + + align:start position:0% +m x i 2 plus uh y i 2 it's just that for +every little Mass particle it's the dist + + align:start position:0% +every little Mass particle it's the dist + + + align:start position:0% +every little Mass particle it's the dist +it's the radius squared away from the + + align:start position:0% +it's the radius squared away from the + + + align:start position:0% +it's the radius squared away from the +center of rotation that's what x^2 + y^ + + align:start position:0% +center of rotation that's what x^2 + y^ + + + align:start position:0% +center of rotation that's what x^2 + y^ +is and we can turn this into an integral + + align:start position:0% +is and we can turn this into an integral + + + align:start position:0% +is and we can turn this into an integral +it's the integral of r² that distance + + align:start position:0% +it's the integral of r² that distance + + + align:start position:0% +it's the integral of r² that distance +times the little Mass bit that's + + align:start position:0% +times the little Mass bit that's + + + align:start position:0% +times the little Mass bit that's +there and + + align:start position:0% +there and + + + align:start position:0% +there and +if that's the same if you wanted to do + + align:start position:0% +if that's the same if you wanted to do + + + align:start position:0% +if that's the same if you wanted to do +the integral as x^2 + + + align:start position:0% +the integral as x^2 + + + + align:start position:0% +the integral as x^2 + +y^2 d m + + align:start position:0% +y^2 d m + + + align:start position:0% +y^2 d m +okay but to do this integral for a nice + + align:start position:0% +okay but to do this integral for a nice + + + align:start position:0% +okay but to do this integral for a nice +circularly symmetric + + align:start position:0% +circularly symmetric + + + align:start position:0% +circularly symmetric +dis all you can pick a little Mass bit + + align:start position:0% +dis all you can pick a little Mass bit + + + align:start position:0% +dis all you can pick a little Mass bit +that has + + align:start position:0% +that has + + + align:start position:0% +that has +thickness Dr + + align:start position:0% +thickness Dr + + + align:start position:0% +thickness Dr +and + + align:start position:0% + + + + align:start position:0% + +width r d Theta this angle here is D + + align:start position:0% +width r d Theta this angle here is D + + + align:start position:0% +width r d Theta this angle here is D +Theta and that's a little bit of area + + align:start position:0% +Theta and that's a little bit of area + + + align:start position:0% +Theta and that's a little bit of area +that's a little + + align:start position:0% +that's a little + + + align:start position:0% +that's a little +da which has area R Dr D Theta it's just + + align:start position:0% +da which has area R Dr D Theta it's just + + + align:start position:0% +da which has area R Dr D Theta it's just +length times width it's little when it's + + align:start position:0% +length times width it's little when it's + + + align:start position:0% +length times width it's little when it's +small enough it's a little rectangle and + + align:start position:0% +small enough it's a little rectangle and + + + align:start position:0% +small enough it's a little rectangle and +it has that + + align:start position:0% +it has that + + + align:start position:0% +it has that +area and it has a + + align:start position:0% +area and it has a + + + align:start position:0% +area and it has a +volume DV the volume of that thing is + + align:start position:0% +volume DV the volume of that thing is + + + align:start position:0% +volume DV the volume of that thing is +just the area times the thickness of it + + align:start position:0% +just the area times the thickness of it + + + align:start position:0% +just the area times the thickness of it +so here's our disc here but it has some + + align:start position:0% +so here's our disc here but it has some + + + align:start position:0% +so here's our disc here but it has some +thickness and I'll call that + + align:start position:0% +thickness and I'll call that + + + align:start position:0% +thickness and I'll call that +H so the volume is just HR Dr r d + + align:start position:0% +H so the volume is just HR Dr r d + + + align:start position:0% +H so the volume is just HR Dr r d +Theta okay and the mass + + align:start position:0% +Theta okay and the mass + + + align:start position:0% +Theta okay and the mass +DM is a density time DV + + align:start position:0% + + + + align:start position:0% + +so I want to integrate this all I have + + align:start position:0% +so I want to integrate this all I have + + + align:start position:0% +so I want to integrate this all I have +to + + align:start position:0% +to + + + align:start position:0% +to +integrate the integral then of R2 + + align:start position:0% +integrate the integral then of R2 + + + align:start position:0% +integrate the integral then of R2 +DM is the integral from 0 to 2 + + align:start position:0% +DM is the integral from 0 to 2 + + + align:start position:0% +DM is the integral from 0 to 2 +pi 0 to + + align:start position:0% +pi 0 to + + + align:start position:0% +pi 0 to +R of row + + align:start position:0% +R of row + + + align:start position:0% +R of row +DV + + align:start position:0% +DV + + + align:start position:0% +DV +row + + align:start position:0% +row + + + align:start position:0% +row +H oh and I need an r squ r R 2 DV is row + + align:start position:0% +H oh and I need an r squ r R 2 DV is row + + + align:start position:0% +H oh and I need an r squ r R 2 DV is row +h r d r d Theta so this is 1802 + + align:start position:0% +h r d r d Theta so this is 1802 + + + align:start position:0% +h r d r d Theta so this is 1802 +integrals right so this is then is this + + align:start position:0% +integrals right so this is then is this + + + align:start position:0% +integrals right so this is then is this +a any of this a function of theta Noe so + + align:start position:0% +a any of this a function of theta Noe so + + + align:start position:0% +a any of this a function of theta Noe so +it's a trivial integral just gives you + + align:start position:0% +it's a trivial integral just gives you + + + align:start position:0% +it's a trivial integral just gives you +integrate that over Theta you just get + + align:start position:0% +integrate that over Theta you just get + + + align:start position:0% +integrate that over Theta you just get +Theta evaluated 0 to 2 pi so this is 2 + + align:start position:0% +Theta evaluated 0 to 2 pi so this is 2 + + + align:start position:0% +Theta evaluated 0 to 2 pi so this is 2 +pi + + align:start position:0% +pi + + + align:start position:0% +pi +row H can all come to the outside + + align:start position:0% +row H can all come to the outside + + + align:start position:0% +row H can all come to the outside +integral 0 to R of R cubed d + + align:start position:0% +integral 0 to R of R cubed d + + + align:start position:0% +integral 0 to R of R cubed d +r and that ends up give the r Cub goes + + align:start position:0% +r and that ends up give the r Cub goes + + + align:start position:0% +r and that ends up give the r Cub goes +to R 4 over + + align:start position:0% +to R 4 over + + + align:start position:0% +to R 4 over +4 and the final result of this one is 2 + + align:start position:0% +4 and the final result of this one is 2 + + + align:start position:0% +4 and the final result of this one is 2 +pi r 4th over + + align:start position:0% +pi r 4th over + + + align:start position:0% +pi r 4th over +4 row H and when you account for H * < + + align:start position:0% +4 row H and when you account for H * < + + + align:start position:0% +4 row H and when you account for H * < +r^ 2 is the volume * row is the mass + + align:start position:0% +r^ 2 is the volume * row is the mass + + + align:start position:0% +r^ 2 is the volume * row is the mass +this all works out to be m r 2/ 2 okay + + align:start position:0% +this all works out to be m r 2/ 2 okay + + + align:start position:0% +this all works out to be m r 2/ 2 okay +so + + align:start position:0% +so + + + align:start position:0% +so +izz so I needed to do this once for you + + align:start position:0% +izz so I needed to do this once for you + + + align:start position:0% +izz so I needed to do this once for you +for simple things to integrate izz in + + align:start position:0% +for simple things to integrate izz in + + + align:start position:0% +for simple things to integrate izz in +this case you just integrate it out + + align:start position:0% +this case you just integrate it out + + + align:start position:0% +this case you just integrate it out +count for all the little Mass bits that + + align:start position:0% +count for all the little Mass bits that + + + align:start position:0% +count for all the little Mass bits that +is the mass moment of inertia with + + align:start position:0% +is the mass moment of inertia with + + + align:start position:0% +is the mass moment of inertia with +respect to the axis passing through the + + align:start position:0% +respect to the axis passing through the + + + align:start position:0% +respect to the axis passing through the +center like + + align:start position:0% +center like + + + align:start position:0% +center like +this pardon + + align:start position:0% +this pardon + + + align:start position:0% +this pardon +it's this this is what I'm talking + + align:start position:0% + + + + align:start position:0% + +about + + align:start position:0% +about + + + align:start position:0% +about +okay + + align:start position:0% + + + + align:start position:0% + +so we need this is moving on to the last + + align:start position:0% + + + + align:start position:0% + +bit so we need to know how to be able to + + align:start position:0% +bit so we need to know how to be able to + + + align:start position:0% +bit so we need to know how to be able to +rotate things about parts places other + + align:start position:0% +rotate things about parts places other + + + align:start position:0% +rotate things about parts places other +than their centers of mass so this is a + + align:start position:0% +than their centers of mass so this is a + + + align:start position:0% +than their centers of mass so this is a +stick I can rotate it about the center + + align:start position:0% +stick I can rotate it about the center + + + align:start position:0% +stick I can rotate it about the center +of mass but it's more interesting if I + + align:start position:0% +of mass but it's more interesting if I + + + align:start position:0% +of mass but it's more interesting if I +rotate it about some other point makes + + align:start position:0% +rotate it about some other point makes + + + align:start position:0% +rotate it about some other point makes +it pendulum when I do it around here so + + align:start position:0% +it pendulum when I do it around here so + + + align:start position:0% +it pendulum when I do it around here so +I need to be able to calculate mass + + align:start position:0% +I need to be able to calculate mass + + + align:start position:0% +I need to be able to calculate mass +moments of inertia about a point that's + + align:start position:0% +moments of inertia about a point that's + + + align:start position:0% +moments of inertia about a point that's +not through the center of mass now I + + align:start position:0% +not through the center of mass now I + + + align:start position:0% +not through the center of mass now I +know you've seen this before in uh in + + align:start position:0% +know you've seen this before in uh in + + + align:start position:0% +know you've seen this before in uh in +801 so this is going to be a quick + + align:start position:0% + + + + align:start position:0% + +reminder but I'll show you where it + + align:start position:0% +reminder but I'll show you where it + + + align:start position:0% +reminder but I'll show you where it +comes from so here's my + + align:start position:0% + + + + align:start position:0% + +stick and I'm going to has a center of + + align:start position:0% +stick and I'm going to has a center of + + + align:start position:0% +stick and I'm going to has a center of +mass and that's where G is located + + align:start position:0% +mass and that's where G is located + + + align:start position:0% +mass and that's where G is located +here has a length total length + + align:start position:0% + + + + align:start position:0% + +L I'm going to give it a thickness + + align:start position:0% + + + + align:start position:0% + +b a + + align:start position:0% +b a + + + align:start position:0% +b a +width a okay so just it's a + + align:start position:0% +width a okay so just it's a + + + align:start position:0% +width a okay so just it's a +stick a wide B thick L + + align:start position:0% +stick a wide B thick L + + + align:start position:0% +stick a wide B thick L +long uniform has a center of gravity + + align:start position:0% +long uniform has a center of gravity + + + align:start position:0% +long uniform has a center of gravity +right in the + + align:start position:0% +right in the + + + align:start position:0% +right in the +middle and I'm going + + align:start position:0% +middle and I'm going + + + align:start position:0% +middle and I'm going +to attach to this + + align:start position:0% +to attach to this + + + align:start position:0% +to attach to this +stick + + align:start position:0% +stick + + + align:start position:0% +stick +a and this this point is kind of hard to + + align:start position:0% +a and this this point is kind of hard to + + + align:start position:0% +a and this this point is kind of hard to +draw this point is at in the center of + + align:start position:0% +draw this point is at in the center of + + + align:start position:0% +draw this point is at in the center of +the stick okay I'm going to put my + + align:start position:0% +the stick okay I'm going to put my + + + align:start position:0% +the stick okay I'm going to put my +coordinate system attached at the center + + align:start position:0% +coordinate system attached at the center + + + align:start position:0% +coordinate system attached at the center +of gravity Center of mass and I'm going + + align:start position:0% +of gravity Center of mass and I'm going + + + align:start position:0% +of gravity Center of mass and I'm going +to make it the + + align:start position:0% +to make it the + + + align:start position:0% +to make it the +uh that's X Prime downward Z Prime and Y + + align:start position:0% +uh that's X Prime downward Z Prime and Y + + + align:start position:0% +uh that's X Prime downward Z Prime and Y +Prime is then going off that way so this + + align:start position:0% +Prime is then going off that way so this + + + align:start position:0% +Prime is then going off that way so this +is a body set of coordinates at the + + align:start position:0% +is a body set of coordinates at the + + + align:start position:0% +is a body set of coordinates at the +center of mass x Prime y Prime Z Prime + + align:start position:0% +center of mass x Prime y Prime Z Prime + + + align:start position:0% +center of mass x Prime y Prime Z Prime +and X happens to be down and I want to + + align:start position:0% +and X happens to be down and I want to + + + align:start position:0% +and X happens to be down and I want to +move I want to calculate my mass moment + + align:start position:0% +move I want to calculate my mass moment + + + align:start position:0% +move I want to calculate my mass moment +of inertia with respect to a point up + + align:start position:0% +of inertia with respect to a point up + + + align:start position:0% +of inertia with respect to a point up +here that is + + align:start position:0% +here that is + + + align:start position:0% +here that is +D this distance I've moved up the xaxis + + align:start position:0% +D this distance I've moved up the xaxis + + + align:start position:0% +D this distance I've moved up the xaxis +in amount + + align:start position:0% +in amount + + + align:start position:0% +in amount +D so I'm going to set a new coordinate + + align:start position:0% +D so I'm going to set a new coordinate + + + align:start position:0% +D so I'm going to set a new coordinate +system up here so if this was Z primed + + align:start position:0% +system up here so if this was Z primed + + + align:start position:0% +system up here so if this was Z primed +my new Z is here it's getting a little + + align:start position:0% +my new Z is here it's getting a little + + + align:start position:0% +my new Z is here it's getting a little +messy and maybe I'll + + align:start position:0% +messy and maybe I'll + + + align:start position:0% +messy and maybe I'll +uh just a face View + + align:start position:0% + + + + align:start position:0% + +if my previously y Prime and X Prime + + align:start position:0% +if my previously y Prime and X Prime + + + align:start position:0% +if my previously y Prime and X Prime +were like that Z coming out of the board + + align:start position:0% +were like that Z coming out of the board + + + align:start position:0% +were like that Z coming out of the board +now I have a new system that is Y and X + + align:start position:0% +now I have a new system that is Y and X + + + align:start position:0% +now I have a new system that is Y and X +like this Z still coming out of the + + align:start position:0% +like this Z still coming out of the + + + align:start position:0% +like this Z still coming out of the +board all + + align:start position:0% + + + + align:start position:0% + +right now the + + align:start position:0% +right now the + + + align:start position:0% +right now the +coordinate so how do I calculate mass + + align:start position:0% +coordinate so how do I calculate mass + + + align:start position:0% +coordinate so how do I calculate mass +moment of + + align:start position:0% +moment of + + + align:start position:0% +moment of +inertia well I want to I want to + + align:start position:0% +inertia well I want to I want to + + + align:start position:0% +inertia well I want to I want to +know I I + + align:start position:0% +know I I + + + align:start position:0% +know I I +want + + align:start position:0% + + + + align:start position:0% + +izz I probably know I Z Prime Z Prime i + + align:start position:0% +izz I probably know I Z Prime Z Prime i + + + align:start position:0% +izz I probably know I Z Prime Z Prime i +z Prime Z Prime is the mass moment of + + align:start position:0% +z Prime Z Prime is the mass moment of + + + align:start position:0% +z Prime Z Prime is the mass moment of +inertia about this point I know it's a + + align:start position:0% +inertia about this point I know it's a + + + align:start position:0% +inertia about this point I know it's a +principal axis from all the things we + + align:start position:0% +principal axis from all the things we + + + align:start position:0% +principal axis from all the things we +just that square block is the same as + + align:start position:0% +just that square block is the same as + + + align:start position:0% +just that square block is the same as +this that's a principal axis in the Z + + align:start position:0% +this that's a principal axis in the Z + + + align:start position:0% +this that's a principal axis in the Z +Prime Direction I know the izz Prime + + align:start position:0% +Prime Direction I know the izz Prime + + + align:start position:0% +Prime Direction I know the izz Prime +with respect to G I want to know it with + + align:start position:0% +with respect to G I want to know it with + + + align:start position:0% +with respect to G I want to know it with +respect to to this + + align:start position:0% +respect to to this + + + align:start position:0% +respect to to this +point so well izz which is my new + + align:start position:0% +point so well izz which is my new + + + align:start position:0% +point so well izz which is my new +location up here and we'll call it a so + + align:start position:0% +location up here and we'll call it a so + + + align:start position:0% +location up here and we'll call it a so +izz here with respect to + + align:start position:0% +izz here with respect to + + + align:start position:0% +izz here with respect to +a is the integral of R 2 DM got to do + + align:start position:0% +a is the integral of R 2 DM got to do + + + align:start position:0% +a is the integral of R 2 DM got to do +the same integral + + align:start position:0% +the same integral + + + align:start position:0% +the same integral +now and but that's + + align:start position:0% +now and but that's + + + align:start position:0% +now and but that's +the integral of x^2 + y^2 + + align:start position:0% + + + + align:start position:0% + +DM but now I can look at this and I can + + align:start position:0% +DM but now I can look at this and I can + + + align:start position:0% +DM but now I can look at this and I can +say oh well these are D this is + + align:start position:0% +say oh well these are D this is + + + align:start position:0% +say oh well these are D this is +separated by D I only moved it in the X + + align:start position:0% +separated by D I only moved it in the X + + + align:start position:0% +separated by D I only moved it in the X +the Y's haven't moved and the Z's didn't + + align:start position:0% +the Y's haven't moved and the Z's didn't + + + align:start position:0% +the Y's haven't moved and the Z's didn't +change I just move my point only in the + + align:start position:0% +change I just move my point only in the + + + align:start position:0% +change I just move my point only in the +X Direction so I can now say that H in + + align:start position:0% +X Direction so I can now say that H in + + + align:start position:0% +X Direction so I can now say that H in +terms of my new + + align:start position:0% +terms of my new + + + align:start position:0% +terms of my new +coordinate it's the same as X Prime + D + + align:start position:0% +coordinate it's the same as X Prime + D + + + align:start position:0% +coordinate it's the same as X Prime + D +the distance from here to a point down + + align:start position:0% +the distance from here to a point down + + + align:start position:0% +the distance from here to a point down +here some Mass + + align:start position:0% +here some Mass + + + align:start position:0% +here some Mass +Point some arbitrary Mass Point XI is + + align:start position:0% +Point some arbitrary Mass Point XI is + + + align:start position:0% +Point some arbitrary Mass Point XI is +going to be x i prime plus + + align:start position:0% +going to be x i prime plus + + + align:start position:0% +going to be x i prime plus +d okay so to do this integral in the new + + align:start position:0% +d okay so to do this integral in the new + + + align:start position:0% +d okay so to do this integral in the new +coordinates this is going to be the + + align:start position:0% +coordinates this is going to be the + + + align:start position:0% +coordinates this is going to be the +integral of x Prime + + + align:start position:0% +integral of x Prime + + + + align:start position:0% +integral of x Prime + +D squared + + + align:start position:0% +D squared + + + + align:start position:0% +D squared + +y now y + + align:start position:0% + + + + align:start position:0% + +Prime equal Y and Z Prime equals z those + + align:start position:0% +Prime equal Y and Z Prime equals z those + + + align:start position:0% +Prime equal Y and Z Prime equals z those +haven't changed I didn't move my + + align:start position:0% +haven't changed I didn't move my + + + align:start position:0% +haven't changed I didn't move my +coordinate system in the y direction or + + align:start position:0% +coordinate system in the y direction or + + + align:start position:0% +coordinate system in the y direction or +the Z Direction so the the coordinate in + + align:start position:0% +the Z Direction so the the coordinate in + + + align:start position:0% +the Z Direction so the the coordinate in +the new system in y is the same as + + align:start position:0% +the new system in y is the same as + + + align:start position:0% +the new system in y is the same as +before so this is just y Prime + + align:start position:0% +before so this is just y Prime + + + align:start position:0% +before so this is just y Prime +squar and this whole thing times + + align:start position:0% +squar and this whole thing times + + + align:start position:0% +squar and this whole thing times +integrated times every little Mass bit + + align:start position:0% +integrated times every little Mass bit + + + align:start position:0% +integrated times every little Mass bit +I'm going to if I expand if I Square + + align:start position:0% +I'm going to if I expand if I Square + + + align:start position:0% +I'm going to if I expand if I Square +this I get X Prime squ 2 x Prime d d ^ 2 + + align:start position:0% +this I get X Prime squ 2 x Prime d d ^ 2 + + + align:start position:0% +this I get X Prime squ 2 x Prime d d ^ 2 ++ y^2 so this + + align:start position:0% ++ y^2 so this + + + align:start position:0% ++ y^2 so this +integral izz with respect to a and you + + align:start position:0% +integral izz with respect to a and you + + + align:start position:0% +integral izz with respect to a and you +rearrange it looks + + align:start position:0% +rearrange it looks + + + align:start position:0% +rearrange it looks +like X Prime 2ar + y Prime squared DM + + align:start position:0% +like X Prime 2ar + y Prime squared DM + + + align:start position:0% +like X Prime 2ar + y Prime squared DM +and the sum uh integral of the sums the + + align:start position:0% +and the sum uh integral of the sums the + + + align:start position:0% +and the sum uh integral of the sums the +sum of the integrals so I break it into + + align:start position:0% +sum of the integrals so I break it into + + + align:start position:0% +sum of the integrals so I break it into +bits here there's a d^2 which is a + + align:start position:0% +bits here there's a d^2 which is a + + + align:start position:0% +bits here there's a d^2 which is a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +DM and then the last term is + + align:start position:0% +DM and then the last term is + + + align:start position:0% +DM and then the last term is +plus + + align:start position:0% +plus + + + align:start position:0% +plus +2D and it's X Prime + + align:start position:0% + + + + align:start position:0% + +DM that's with this just multiply this + + align:start position:0% +DM that's with this just multiply this + + + align:start position:0% +DM that's with this just multiply this +out rewrite it break it + + align:start position:0% +out rewrite it break it + + + align:start position:0% +out rewrite it break it +apart integral of well let's do this one + + align:start position:0% +apart integral of well let's do this one + + + align:start position:0% +apart integral of well let's do this one +integral of x Prime s + y Prim s DM you + + align:start position:0% +integral of x Prime s + y Prim s DM you + + + align:start position:0% +integral of x Prime s + y Prim s DM you +know that's something that we already + + align:start position:0% +know that's something that we already + + + align:start position:0% +know that's something that we already +have a name + + align:start position:0% +have a name + + + align:start position:0% +have a name +for this is i g + + align:start position:0% + + + + align:start position:0% + +in ZZ it's the original Mass moment of + + align:start position:0% +in ZZ it's the original Mass moment of + + + align:start position:0% +in ZZ it's the original Mass moment of +inertia with respect to the original + + align:start position:0% +inertia with respect to the original + + + align:start position:0% +inertia with respect to the original +coordinate system at g in the Z + + align:start position:0% +coordinate system at g in the Z + + + align:start position:0% +coordinate system at g in the Z +Direction so it's I + + align:start position:0% +Direction so it's I + + + align:start position:0% +Direction so it's I +zzg okay that's we already know that + + align:start position:0% +zzg okay that's we already know that + + + align:start position:0% +zzg okay that's we already know that +that's given for the object plus this is + + align:start position:0% +that's given for the object plus this is + + + align:start position:0% +that's given for the object plus this is +the integral of DM over the whole extent + + align:start position:0% +the integral of DM over the whole extent + + + align:start position:0% +the integral of DM over the whole extent +of the + + align:start position:0% +of the + + + align:start position:0% +of the +object just the mass of the + + align:start position:0% + + + + align:start position:0% + +object and this integral + + align:start position:0% + + + + align:start position:0% + +this is the integral in terms of the x + + align:start position:0% +this is the integral in terms of the x + + + align:start position:0% +this is the integral in terms of the x +coordinate and every Mass bit from here + + align:start position:0% +coordinate and every Mass bit from here + + + align:start position:0% +coordinate and every Mass bit from here +if I go out here and find one there's an + + align:start position:0% +if I go out here and find one there's an + + + align:start position:0% +if I go out here and find one there's an +equal and opposite one up here this is + + align:start position:0% +equal and opposite one up here this is + + + align:start position:0% +equal and opposite one up here this is +the definition of the center of mass + + align:start position:0% +the definition of the center of mass + + + align:start position:0% +the definition of the center of mass +this integral if I'm at the center of + + align:start position:0% +this integral if I'm at the center of + + + align:start position:0% +this integral if I'm at the center of +mass integrating out from it this is + + align:start position:0% +mass integrating out from it this is + + + align:start position:0% +mass integrating out from it this is +zero because of the definition of the + + align:start position:0% +zero because of the definition of the + + + align:start position:0% +zero because of the definition of the +center of + + align:start position:0% +center of + + + align:start position:0% +center of +mass and I've just proven the parallel + + align:start position:0% +mass and I've just proven the parallel + + + align:start position:0% +mass and I've just proven the parallel +axis theorem + + align:start position:0% +axis theorem + + + align:start position:0% +axis theorem +izz about this new point is I about G+ + + align:start position:0% +izz about this new point is I about G+ + + + align:start position:0% +izz about this new point is I about G+ +md^ 2 where d^2 is the distance I've + + align:start position:0% +md^ 2 where d^2 is the distance I've + + + align:start position:0% +md^ 2 where d^2 is the distance I've +moved the Z axis to a new place parallel + + align:start position:0% +moved the Z axis to a new place parallel + + + align:start position:0% +moved the Z axis to a new place parallel +to + + align:start position:0% + + + + align:start position:0% + +it okay + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +izz with for for with respect to + + align:start position:0% +izz with for for with respect to + + + align:start position:0% +izz with for for with respect to +G the original Mass moment of inertia + + align:start position:0% +G the original Mass moment of inertia + + + align:start position:0% +G the original Mass moment of inertia +for RO the for + + align:start position:0% +for RO the for + + + align:start position:0% +for RO the for +izz is um m + + align:start position:0% +izz is um m + + + align:start position:0% +izz is um m +l^2 + a 2 over + + align:start position:0% + + + + align:start position:0% + +12 and + + align:start position:0% + + + + align:start position:0% + +iixx + + align:start position:0% +iixx + + + align:start position:0% +iixx +M L 2 + b^ + + align:start position:0% +M L 2 + b^ + + + align:start position:0% +M L 2 + b^ +2 over + + align:start position:0% +2 over + + + align:start position:0% +2 over +12 and + + align:start position:0% + + + + align:start position:0% + +I ZZ + + align:start position:0% +I ZZ + + + align:start position:0% +I ZZ +oh we already we already know that + + align:start position:0% + + + + align:start position:0% + +one oh wait a minute I don't haven't + + align:start position:0% +one oh wait a minute I don't haven't + + + align:start position:0% +one oh wait a minute I don't haven't +told you what that is it's izz iixx i y + + align:start position:0% +told you what that is it's izz iixx i y + + + align:start position:0% +told you what that is it's izz iixx i y +y I'm just a little messy here iy y for + + align:start position:0% +y I'm just a little messy here iy y for + + + align:start position:0% +y I'm just a little messy here iy y for +this problem + + align:start position:0% + + + + align:start position:0% + +is I have made a mistake ixx is a 2 + b^ + + align:start position:0% +is I have made a mistake ixx is a 2 + b^ + + + align:start position:0% +is I have made a mistake ixx is a 2 + b^ +2 i y y is m l 2 + + align:start position:0% + + + + align:start position:0% + +plus b^2 so those are the three all with + + align:start position:0% +plus b^2 so those are the three all with + + + align:start position:0% +plus b^2 so those are the three all with +respect to G for this stick okay and I'm + + align:start position:0% +respect to G for this stick okay and I'm + + + align:start position:0% +respect to G for this stick okay and I'm +going + + align:start position:0% + + + + align:start position:0% + +to yeah + + align:start position:0% + + + + align:start position:0% + +okay that kind of sets us up where I can + + align:start position:0% +okay that kind of sets us up where I can + + + align:start position:0% +okay that kind of sets us up where I can +pick up next time so let's finish by + + align:start position:0% +pick up next time so let's finish by + + + align:start position:0% +pick up next time so let's finish by +asking ourselves + + align:start position:0% +asking ourselves + + + align:start position:0% +asking ourselves +the + + align:start position:0% + + + + align:start position:0% + +question what do we think about if I've + + align:start position:0% +question what do we think about if I've + + + align:start position:0% +question what do we think about if I've +moved to this new po new + + align:start position:0% +moved to this new po new + + + align:start position:0% +moved to this new po new +position and I'm not rotating about the + + align:start position:0% +position and I'm not rotating about the + + + align:start position:0% +position and I'm not rotating about the +center is this new axis this one around + + align:start position:0% +center is this new axis this one around + + + align:start position:0% +center is this new axis this one around +around the center + + align:start position:0% +around the center + + + align:start position:0% +around the center +before that one we know is a principal + + align:start position:0% +before that one we know is a principal + + + align:start position:0% +before that one we know is a principal +axis is the new if I rotate about this + + align:start position:0% +axis is the new if I rotate about this + + + align:start position:0% +axis is the new if I rotate about this +new place which I've defined the mass + + align:start position:0% +new place which I've defined the mass + + + align:start position:0% +new place which I've defined the mass +moment inti about that place is this a + + align:start position:0% +moment inti about that place is this a + + + align:start position:0% +moment inti about that place is this a +principal + + align:start position:0% +principal + + + align:start position:0% +principal +axis how many think + + align:start position:0% +axis how many think + + + align:start position:0% +axis how many think +yes how many think + + align:start position:0% +yes how many think + + + align:start position:0% +yes how many think +no okay so a little and lots of people + + align:start position:0% +no okay so a little and lots of people + + + align:start position:0% +no okay so a little and lots of people +not + + align:start position:0% +not + + + align:start position:0% +not +sure so the dynamic my dynamic + + align:start position:0% +sure so the dynamic my dynamic + + + align:start position:0% +sure so the dynamic my dynamic +definition of principal axis is if you + + align:start position:0% +definition of principal axis is if you + + + align:start position:0% +definition of principal axis is if you +can rotate the object about that axis + + align:start position:0% +can rotate the object about that axis + + + align:start position:0% +can rotate the object about that axis +and produce no unbalanced Torx it's a + + align:start position:0% +and produce no unbalanced Torx it's a + + + align:start position:0% +and produce no unbalanced Torx it's a +principal axis and I can do that this + + align:start position:0% +principal axis and I can do that this + + + align:start position:0% +principal axis and I can do that this +thing will just spin all day long now + + align:start position:0% +thing will just spin all day long now + + + align:start position:0% +thing will just spin all day long now +there is a force there's you can think + + align:start position:0% +there is a force there's you can think + + + align:start position:0% +there is a force there's you can think +of the fictitious Force there's a center + + align:start position:0% +of the fictitious Force there's a center + + + align:start position:0% +of the fictitious Force there's a center +of mass out here as it spins around + + align:start position:0% +of mass out here as it spins around + + + align:start position:0% +of mass out here as it spins around +there's a centripetal acceleration + + align:start position:0% +there's a centripetal acceleration + + + align:start position:0% +there's a centripetal acceleration +making it go in the circle that means + + align:start position:0% +making it go in the circle that means + + + align:start position:0% +making it go in the circle that means +that fictitious force is like there is a + + align:start position:0% +that fictitious force is like there is a + + + align:start position:0% +that fictitious force is like there is a +centrifugal force pull pulling out on it + + align:start position:0% +centrifugal force pull pulling out on it + + + align:start position:0% +centrifugal force pull pulling out on it +do I feel that do I have to resist that + + align:start position:0% +do I feel that do I have to resist that + + + align:start position:0% +do I feel that do I have to resist that +Force as it goes round and round yes so + + align:start position:0% +Force as it goes round and round yes so + + + align:start position:0% +Force as it goes round and round yes so +there that is an imbalance of a kind we + + align:start position:0% +there that is an imbalance of a kind we + + + align:start position:0% +there that is an imbalance of a kind we +know as a static imbalance but it + + align:start position:0% +know as a static imbalance but it + + + align:start position:0% +know as a static imbalance but it +doesn't produce torqux about this my G + + align:start position:0% +doesn't produce torqux about this my G + + + align:start position:0% +doesn't produce torqux about this my G +my center of my Axis right lined up on + + align:start position:0% +my center of my Axis right lined up on + + + align:start position:0% +my center of my Axis right lined up on +this + + align:start position:0% +this + + + align:start position:0% +this +Center okay doesn't gravity p on + + align:start position:0% + + + + align:start position:0% + +the sure gravity does but that's now a + + align:start position:0% +the sure gravity does but that's now a + + + align:start position:0% +the sure gravity does but that's now a +different problem that's what makes this + + align:start position:0% +different problem that's what makes this + + + align:start position:0% +different problem that's what makes this +thing act like an + + align:start position:0% +thing act like an + + + align:start position:0% +thing act like an +oscillator okay the torqux of the kind + + align:start position:0% +oscillator okay the torqux of the kind + + + align:start position:0% +oscillator okay the torqux of the kind +I'm talking about is if I compute the + + align:start position:0% +I'm talking about is if I compute the + + + align:start position:0% +I'm talking about is if I compute the +angular + + align:start position:0% +angular + + + align:start position:0% +angular +momentum of this thing and take compute + + align:start position:0% +momentum of this thing and take compute + + + align:start position:0% +momentum of this thing and take compute +dhdt the time rate of change of the + + align:start position:0% +dhdt the time rate of change of the + + + align:start position:0% +dhdt the time rate of change of the +angular momentum is a torque on the + + align:start position:0% +angular momentum is a torque on the + + + align:start position:0% +angular momentum is a torque on the +system right I will get the term that + + align:start position:0% +system right I will get the term that + + + align:start position:0% +system right I will get the term that +makes it spin faster and I will get if + + align:start position:0% +makes it spin faster and I will get if + + + align:start position:0% +makes it spin faster and I will get if +they exist terms that make it want to + + align:start position:0% +they exist terms that make it want to + + + align:start position:0% +they exist terms that make it want to +bend this way or bend you know Bend back + + align:start position:0% +bend this way or bend you know Bend back + + + align:start position:0% +bend this way or bend you know Bend back +it only happens if if I if I if I hold + + align:start position:0% +it only happens if if I if I if I hold + + + align:start position:0% +it only happens if if I if I if I hold +this thing over + + align:start position:0% +this thing over + + + align:start position:0% +this thing over +here and spin it get it spinning and I + + align:start position:0% +here and spin it get it spinning and I + + + align:start position:0% +here and spin it get it spinning and I +compute the angular momentum with this + + align:start position:0% +compute the angular momentum with this + + + align:start position:0% +compute the angular momentum with this +back to this point will I get torqux + + align:start position:0% +back to this point will I get torqux + + + align:start position:0% +back to this point will I get torqux +yeah but that's not how I that's that's + + align:start position:0% +yeah but that's not how I that's that's + + + align:start position:0% +yeah but that's not how I that's that's +that's a different problem we computed I + + align:start position:0% +that's a different problem we computed I + + + align:start position:0% +that's a different problem we computed I +the IG is as if I were Computing the + + align:start position:0% +the IG is as if I were Computing the + + + align:start position:0% +the IG is as if I were Computing the +angular momentum I remember I started + + align:start position:0% +angular momentum I remember I started + + + align:start position:0% +angular momentum I remember I started +defining Mass moment of inertia Matrix + + align:start position:0% +defining Mass moment of inertia Matrix + + + align:start position:0% +defining Mass moment of inertia Matrix +based on an angular momentum computation + + align:start position:0% +based on an angular momentum computation + + + align:start position:0% +based on an angular momentum computation +at G so it's right there in the center + + align:start position:0% +at G so it's right there in the center + + + align:start position:0% +at G so it's right there in the center +of this object there's no moment arm + + align:start position:0% +of this object there's no moment arm + + + align:start position:0% +of this object there's no moment arm +that is causing torqux that's trying to + + align:start position:0% +that is causing torqux that's trying to + + + align:start position:0% +that is causing torqux that's trying to +twist this thing about that point okay + + align:start position:0% +twist this thing about that point okay + + + align:start position:0% +twist this thing about that point okay +so when the answer to question is this + + align:start position:0% +so when the answer to question is this + + + align:start position:0% +so when the answer to question is this +is a this is a principal axis yeah um so + + align:start position:0% +is a this is a principal axis yeah um so + + + align:start position:0% +is a this is a principal axis yeah um so +if you + + align:start position:0% +if you + + + align:start position:0% +if you +take getor that are not in + + align:start position:0% +take getor that are not in + + + align:start position:0% +take getor that are not in +that then either if you get torqus that + + align:start position:0% +that then either if you get torqus that + + + align:start position:0% +that then either if you get torqus that +aren't in that direction you either you + + align:start position:0% +aren't in that direction you either you + + + align:start position:0% +aren't in that direction you either you +made a mistake doing the math or you + + align:start position:0% +made a mistake doing the math or you + + + align:start position:0% +made a mistake doing the math or you +started you were in error in identifying + + align:start position:0% +started you were in error in identifying + + + align:start position:0% +started you were in error in identifying +the mass moment of inertia Matrix to + + align:start position:0% +the mass moment of inertia Matrix to + + + align:start position:0% +the mass moment of inertia Matrix to +begin with because if you get torqus + + align:start position:0% +begin with because if you get torqus + + + align:start position:0% +begin with because if you get torqus +that must be nonzero off diagonal terms + + align:start position:0% +that must be nonzero off diagonal terms + + + align:start position:0% +that must be nonzero off diagonal terms +in the mass moment of inertia Matrix + + align:start position:0% +in the mass moment of inertia Matrix + + + align:start position:0% +in the mass moment of inertia Matrix +they are what account for the + + align:start position:0% +they are what account for the + + + align:start position:0% +they are what account for the +torqus okay so any by this parallel axis + + align:start position:0% +torqus okay so any by this parallel axis + + + align:start position:0% +torqus okay so any by this parallel axis +theem any other axis you go to if you + + align:start position:0% +theem any other axis you go to if you + + + align:start position:0% +theem any other axis you go to if you +started at a principal axis any other + + align:start position:0% +started at a principal axis any other + + + align:start position:0% +started at a principal axis any other +axis you create is also a principal axis + + align:start position:0% +axis you create is also a principal axis + + + align:start position:0% +axis you create is also a principal axis +that's the movement of just one axis if + + align:start position:0% +that's the movement of just one axis if + + + align:start position:0% +that's the movement of just one axis if +you do two if you move this way and this + + align:start position:0% +you do two if you move this way and this + + + align:start position:0% +you do two if you move this way and this +way is all bets are off you get a + + align:start position:0% +way is all bets are off you get a + + + align:start position:0% +way is all bets are off you get a +different answer and if you're + + align:start position:0% +different answer and if you're + + + align:start position:0% +different answer and if you're +interested in that more complicated + + align:start position:0% +interested in that more complicated + + + align:start position:0% +interested in that more complicated +problem read that Williams thing because + + align:start position:0% +problem read that Williams thing because + + + align:start position:0% +problem read that Williams thing because +he does the complete parallel axis + + align:start position:0% +he does the complete parallel axis + + + align:start position:0% +he does the complete parallel axis +parallel planes and comes with a super + + align:start position:0% +parallel planes and comes with a super + + + align:start position:0% +parallel planes and comes with a super +compact little way of calculating them + + align:start position:0% +compact little way of calculating them + + + align:start position:0% +compact little way of calculating them +okay see you on Thursday + + align:start position:0% + + + + align:start position:0% + +for \ No newline at end of file diff --git a/YgyshX9T3S4.txt b/YgyshX9T3S4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b5e98ab84218c6c05f4f4ae73a16a5bdce73e209 --- /dev/null +++ b/YgyshX9T3S4.txt @@ -0,0 +1,12643 @@ +align:start position:0% + +laughs + + align:start position:0% + + + + align:start position:0% + +okay so so last time + + align:start position:0% +okay so so last time + + + align:start position:0% +okay so so last time +we talked about the rock equation + + align:start position:0% +we talked about the rock equation + + + align:start position:0% +we talked about the rock equation +so the Iraq equation has the following + + align:start position:0% +so the Iraq equation has the following + + + align:start position:0% +so the Iraq equation has the following +form + + align:start position:0% + + + + align:start position:0% + +gamma mu + + align:start position:0% +gamma mu + + + align:start position:0% +gamma mu +partial mu + + align:start position:0% +partial mu + + + align:start position:0% +partial mu +minus m + + align:start position:0% +minus m + + + align:start position:0% +minus m +PSI equal to zero + + align:start position:0% +PSI equal to zero + + + align:start position:0% +PSI equal to zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so here we have two spaces + + align:start position:0% +so so here we have two spaces + + + align:start position:0% +so so here we have two spaces +so Y is your + + align:start position:0% +so Y is your + + + align:start position:0% +so Y is your +standard physical space time + + align:start position:0% +standard physical space time + + + align:start position:0% +standard physical space time +so with X mu + + align:start position:0% +so with X mu + + + align:start position:0% +so with X mu +and then we have a lot of internal space + + align:start position:0% +and then we have a lot of internal space + + + align:start position:0% +and then we have a lot of internal space +which is labeled by the index of The + + align:start position:0% +which is labeled by the index of The + + + align:start position:0% +which is labeled by the index of The +Upside and the gamma which has + + align:start position:0% +Upside and the gamma which has + + + align:start position:0% +Upside and the gamma which has +suppressed here so psi should be + + align:start position:0% +suppressed here so psi should be + + + align:start position:0% +suppressed here so psi should be +considered as a four vector + + align:start position:0% + + + + align:start position:0% + +the alpha equal to one two three four + + align:start position:0% +the alpha equal to one two three four + + + align:start position:0% +the alpha equal to one two three four +and the gamma mu + + align:start position:0% +and the gamma mu + + + align:start position:0% +and the gamma mu +should be considered as a matrix + + align:start position:0% + + + + align:start position:0% + +okay four by four Matrix + + align:start position:0% +okay four by four Matrix + + + align:start position:0% +okay four by four Matrix +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so so this space labeled by by Alpha + + align:start position:0% +and so so this space labeled by by Alpha + + + align:start position:0% +and so so this space labeled by by Alpha +so this is called the spinner space + + align:start position:0% + + + + align:start position:0% + +is equal spinner space so uh so you have + + align:start position:0% +is equal spinner space so uh so you have + + + align:start position:0% +is equal spinner space so uh so you have +to be careful that now we have two uh + + align:start position:0% +to be careful that now we have two uh + + + align:start position:0% +to be careful that now we have two uh +spaces in the time together okay one is + + align:start position:0% +spaces in the time together okay one is + + + align:start position:0% +spaces in the time together okay one is +your ordinary space time and so this is + + align:start position:0% +your ordinary space time and so this is + + + align:start position:0% +your ordinary space time and so this is +the function of the space time + + align:start position:0% +the function of the space time + + + align:start position:0% +the function of the space time +by this Carriage on index yeah uh + + align:start position:0% +by this Carriage on index yeah uh + + + align:start position:0% +by this Carriage on index yeah uh +carries on indices and so this is the a + + align:start position:0% +carries on indices and so this is the a + + + align:start position:0% +carries on indices and so this is the a +matrix equation + + align:start position:0% +matrix equation + + + align:start position:0% +matrix equation +so all together they are there are four + + align:start position:0% +so all together they are there are four + + + align:start position:0% +so all together they are there are four +four equations here for each component + + align:start position:0% +four equations here for each component + + + align:start position:0% +four equations here for each component +of PSI okay + + align:start position:0% + + + + align:start position:0% + +okay and uh yeah so let me call + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let me call this equation one + + align:start position:0% +so let me call this equation one + + + align:start position:0% +so let me call this equation one +whichever this nature + + align:start position:0% +whichever this nature + + + align:start position:0% +whichever this nature +will be a lot ordinary images they + + align:start position:0% +will be a lot ordinary images they + + + align:start position:0% +will be a lot ordinary images they +satisfy this condition + + align:start position:0% + + + + align:start position:0% + +with new equal to Q is a blue + + align:start position:0% + + + + align:start position:0% + +so that means + + align:start position:0% +so that means + + + align:start position:0% +so that means +different gamma matrices when their + + align:start position:0% +different gamma matrices when their + + + align:start position:0% +different gamma matrices when their +index are not the same + + align:start position:0% +index are not the same + + + align:start position:0% +index are not the same +the anti-commute with each other + + align:start position:0% +the anti-commute with each other + + + align:start position:0% +the anti-commute with each other +okay so if you come uh you pass them + + align:start position:0% +okay so if you come uh you pass them + + + align:start position:0% +okay so if you come uh you pass them +through you get the minus sign okay so + + align:start position:0% +through you get the minus sign okay so + + + align:start position:0% +through you get the minus sign okay so +the anti-compute with each other because + + align:start position:0% +the anti-compute with each other because + + + align:start position:0% +the anti-compute with each other because +when we will not continue the right hand + + align:start position:0% +when we will not continue the right hand + + + align:start position:0% +when we will not continue the right hand +side is zero and uh when you pass + + align:start position:0% +side is zero and uh when you pass + + + align:start position:0% +side is zero and uh when you pass +through each other you get the minus + + align:start position:0% +through each other you get the minus + + + align:start position:0% +through each other you get the minus +under the square of them so gamma zero + + align:start position:0% +under the square of them so gamma zero + + + align:start position:0% +under the square of them so gamma zero +Square you get the minus one because + + align:start position:0% +Square you get the minus one because + + + align:start position:0% +Square you get the minus one because +this is zero zero it's minus one and the + + align:start position:0% +this is zero zero it's minus one and the + + + align:start position:0% +this is zero zero it's minus one and the +gamma I squared in this case one okay so + + align:start position:0% +gamma I squared in this case one okay so + + + align:start position:0% +gamma I squared in this case one okay so +so this is very simple + + align:start position:0% +so this is very simple + + + align:start position:0% +so this is very simple +yes + + align:start position:0% + + + + align:start position:0% + +yeah it's the identity Matrix yeah yeah + + align:start position:0% +yeah it's the identity Matrix yeah yeah + + + align:start position:0% +yeah it's the identity Matrix yeah yeah +when I say gamma zero squares minus one + + align:start position:0% +when I say gamma zero squares minus one + + + align:start position:0% +when I say gamma zero squares minus one +is also minus times identity Matrix + + align:start position:0% +is also minus times identity Matrix + + + align:start position:0% +is also minus times identity Matrix +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +and also not all gamma mu are Commission + + align:start position:0% +and also not all gamma mu are Commission + + + align:start position:0% +and also not all gamma mu are Commission +so so the relation is that the the gamma + + align:start position:0% +so so the relation is that the the gamma + + + align:start position:0% +so so the relation is that the the gamma +mu dagger is equal to gamma mu comma + + align:start position:0% +mu dagger is equal to gamma mu comma + + + align:start position:0% +mu dagger is equal to gamma mu comma +zero common mu comma zero okay + + align:start position:0% +zero common mu comma zero okay + + + align:start position:0% +zero common mu comma zero okay +so so again from here you can + + align:start position:0% +so so again from here you can + + + align:start position:0% +so so again from here you can +yeah so this is just a compact way to uh + + align:start position:0% +yeah so this is just a compact way to uh + + + align:start position:0% +yeah so this is just a compact way to uh +to to write the uh its properties when + + align:start position:0% +to to write the uh its properties when + + + align:start position:0% +to to write the uh its properties when +you have when when mu is equal to zero + + align:start position:0% +you have when when mu is equal to zero + + + align:start position:0% +you have when when mu is equal to zero +and then you have comma 0 times gamma + + align:start position:0% +and then you have comma 0 times gamma + + + align:start position:0% +and then you have comma 0 times gamma +zero square is -1 and then you get the + + align:start position:0% +zero square is -1 and then you get the + + + align:start position:0% +zero square is -1 and then you get the +minus comma zero tells you that gamma + + align:start position:0% +minus comma zero tells you that gamma + + + align:start position:0% +minus comma zero tells you that gamma +zero is anti-commission + + align:start position:0% +zero is anti-commission + + + align:start position:0% +zero is anti-commission +and if you take the index to be I here + + align:start position:0% +and if you take the index to be I here + + + align:start position:0% +and if you take the index to be I here +and then you have index I here and then + + align:start position:0% +and then you have index I here and then + + + align:start position:0% +and then you have index I here and then +when zero and I they're not the same so + + align:start position:0% +when zero and I they're not the same so + + + align:start position:0% +when zero and I they're not the same so +the anti-commute you can pass through + + align:start position:0% +the anti-commute you can pass through + + + align:start position:0% +the anti-commute you can pass through +this gamma zero through this gamma I you + + align:start position:0% +this gamma zero through this gamma I you + + + align:start position:0% +this gamma zero through this gamma I you +get the minus sign and then gamma zero + + align:start position:0% +get the minus sign and then gamma zero + + + align:start position:0% +get the minus sign and then gamma zero +Square give you another minus sign so + + align:start position:0% +Square give you another minus sign so + + + align:start position:0% +Square give you another minus sign so +you get one so that means that the gamma + + align:start position:0% +you get one so that means that the gamma + + + align:start position:0% +you get one so that means that the gamma +I dagger equal to gamma I okay so gamma + + align:start position:0% +I dagger equal to gamma I okay so gamma + + + align:start position:0% +I dagger equal to gamma I okay so gamma +I is commission okay yes + + align:start position:0% + + + + align:start position:0% + +uh so in my convention there's no I + + align:start position:0% +uh so in my convention there's no I + + + align:start position:0% +uh so in my convention there's no I +so with this + + align:start position:0% +so with this + + + align:start position:0% +so with this +so so it's a mu mu here is mostly plus + + align:start position:0% +so so it's a mu mu here is mostly plus + + + align:start position:0% +so so it's a mu mu here is mostly plus +metric + + align:start position:0% +metric + + + align:start position:0% +metric +so some people when they use say mostly + + align:start position:0% +so some people when they use say mostly + + + align:start position:0% +so some people when they use say mostly +negative metric then there may be a i + + align:start position:0% +negative metric then there may be a i + + + align:start position:0% +negative metric then there may be a i +in in there yeah yeah yeah so it's + + align:start position:0% +in in there yeah yeah yeah so it's + + + align:start position:0% +in in there yeah yeah yeah so it's +depend on your convention in defining + + align:start position:0% +depend on your convention in defining + + + align:start position:0% +depend on your convention in defining +the gamma matrices + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% + + + + align:start position:0% + +good other questions + + align:start position:0% +good other questions + + + align:start position:0% +good other questions +yeah as I mentioned last time different + + align:start position:0% +yeah as I mentioned last time different + + + align:start position:0% +yeah as I mentioned last time different +conventions are loined so but you just + + align:start position:0% +conventions are loined so but you just + + + align:start position:0% +conventions are loined so but you just +stick one convention should be fine + + align:start position:0% +stick one convention should be fine + + + align:start position:0% +stick one convention should be fine +stick to my convention would be fine yes + + align:start position:0% + + + + align:start position:0% + +oh yeah this is just a compact way to + + align:start position:0% +oh yeah this is just a compact way to + + + align:start position:0% +oh yeah this is just a compact way to +write down that gamma zero is + + align:start position:0% +write down that gamma zero is + + + align:start position:0% +write down that gamma zero is +anti-hubmission and Gamma I is formation + + align:start position:0% +anti-hubmission and Gamma I is formation + + + align:start position:0% +anti-hubmission and Gamma I is formation +okay yeah yeah just uh at least just + + align:start position:0% +okay yeah yeah just uh at least just + + + align:start position:0% +okay yeah yeah just uh at least just +compact yeah just this is useful so that + + align:start position:0% +compact yeah just this is useful so that + + + align:start position:0% +compact yeah just this is useful so that +you can treat all gamma mule in the same + + align:start position:0% +you can treat all gamma mule in the same + + + align:start position:0% +you can treat all gamma mule in the same +way + + align:start position:0% +way + + + align:start position:0% +way +so that you don't have to always + + align:start position:0% +so that you don't have to always + + + align:start position:0% +so that you don't have to always +separate them yeah + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +other questions + + align:start position:0% + + + + align:start position:0% + +okay so last time we also said + + align:start position:0% +okay so last time we also said + + + align:start position:0% +okay so last time we also said +you have many many choices for gamma mu + + align:start position:0% +you have many many choices for gamma mu + + + align:start position:0% +you have many many choices for gamma mu +but they are all equivalent physically + + align:start position:0% +but they are all equivalent physically + + + align:start position:0% +but they are all equivalent physically +equivalent and so different choices they + + align:start position:0% +equivalent and so different choices they + + + align:start position:0% +equivalent and so different choices they +are convenient for different purposes + + align:start position:0% +are convenient for different purposes + + + align:start position:0% +are convenient for different purposes +okay so often we just pick one of them + + align:start position:0% +okay so often we just pick one of them + + + align:start position:0% +okay so often we just pick one of them +and depend on a depending on the problem + + align:start position:0% +and depend on a depending on the problem + + + align:start position:0% +and depend on a depending on the problem +we are yeah so that comes with + + align:start position:0% +we are yeah so that comes with + + + align:start position:0% +we are yeah so that comes with +experience so for certain problems + + align:start position:0% +experience so for certain problems + + + align:start position:0% +experience so for certain problems +certain choices of gamma become more + + align:start position:0% +certain choices of gamma become more + + + align:start position:0% +certain choices of gamma become more +useful yeah become more easier to + + align:start position:0% +useful yeah become more easier to + + + align:start position:0% +useful yeah become more easier to +manipulate + + align:start position:0% + + + + align:start position:0% + +okay good so now let's talk about the + + align:start position:0% +okay good so now let's talk about the + + + align:start position:0% +okay good so now let's talk about the +Lorenz covariance + + align:start position:0% +Lorenz covariance + + + align:start position:0% +Lorenz covariance +of the Iraq equation + + align:start position:0% + + + + align:start position:0% + +which we started a little bit last time + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +Lorraine's quarries means that the + + align:start position:0% +Lorraine's quarries means that the + + + align:start position:0% +Lorraine's quarries means that the +equation looks the same + + align:start position:0% +equation looks the same + + + align:start position:0% +equation looks the same +in all orange frames okay so so when you + + align:start position:0% +in all orange frames okay so so when you + + + align:start position:0% +in all orange frames okay so so when you +make a chlorine transformation + + align:start position:0% +make a chlorine transformation + + + align:start position:0% +make a chlorine transformation +so imagine you make a + + align:start position:0% +so imagine you make a + + + align:start position:0% +so imagine you make a +go to another frame you start with your + + align:start position:0% +go to another frame you start with your + + + align:start position:0% +go to another frame you start with your +frame defined by this x mu so now + + align:start position:0% +frame defined by this x mu so now + + + align:start position:0% +frame defined by this x mu so now +imagine you go to another frame + + align:start position:0% +imagine you go to another frame + + + align:start position:0% +imagine you go to another frame +which you make a low range + + align:start position:0% +which you make a low range + + + align:start position:0% +which you make a low range +transformation + + align:start position:0% + + + + align:start position:0% + +Okay so + + align:start position:0% +Okay so + + + align:start position:0% +Okay so +the low range covariance means you you + + align:start position:0% +the low range covariance means you you + + + align:start position:0% +the low range covariance means you you +see your equation when written in this + + align:start position:0% +see your equation when written in this + + + align:start position:0% +see your equation when written in this +frame in terms of X Prime mu have the + + align:start position:0% +frame in terms of X Prime mu have the + + + align:start position:0% +frame in terms of X Prime mu have the +same form okay have the same form so + + align:start position:0% +same form okay have the same form so + + + align:start position:0% +same form okay have the same form so +last time we talked about the scalar + + align:start position:0% +last time we talked about the scalar + + + align:start position:0% +last time we talked about the scalar +equations at the end + + align:start position:0% +equations at the end + + + align:start position:0% +equations at the end +and a lot of the equation we have seen + + align:start position:0% +and a lot of the equation we have seen + + + align:start position:0% +and a lot of the equation we have seen +before + + align:start position:0% +before + + + align:start position:0% +before +is the is the Maxwell equation okay so + + align:start position:0% +is the is the Maxwell equation okay so + + + align:start position:0% +is the is the Maxwell equation okay so +so let me also very quickly mention uh + + align:start position:0% +so let me also very quickly mention uh + + + align:start position:0% +so let me also very quickly mention uh +for the Maxwell equation so so when you + + align:start position:0% +for the Maxwell equation so so when you + + + align:start position:0% +for the Maxwell equation so so when you +have a Maxwell equation + + align:start position:0% + + + + align:start position:0% + +which is the story for the + + align:start position:0% +which is the story for the + + + align:start position:0% +which is the story for the +Vector potential + + align:start position:0% +Vector potential + + + align:start position:0% +Vector potential +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now in contrast we remember for the + + align:start position:0% +so now in contrast we remember for the + + + align:start position:0% +so now in contrast we remember for the +scalar case + + align:start position:0% + + + + align:start position:0% + +so so last time yeah let me just write + + align:start position:0% +so so last time yeah let me just write + + + align:start position:0% +so so last time yeah let me just write +it down here last time we said for the + + align:start position:0% +it down here last time we said for the + + + align:start position:0% +it down here last time we said for the +scalar case + + align:start position:0% +scalar case + + + align:start position:0% +scalar case +when you go to different frame + + align:start position:0% +when you go to different frame + + + align:start position:0% +when you go to different frame +the five Prime should be equal to + + align:start position:0% +the five Prime should be equal to + + + align:start position:0% +the five Prime should be equal to +evaluate to do coordinate should be + + align:start position:0% +evaluate to do coordinate should be + + + align:start position:0% +evaluate to do coordinate should be +equal to 5x okay so this is the + + align:start position:0% +equal to 5x okay so this is the + + + align:start position:0% +equal to 5x okay so this is the +transformation for scalar field + + align:start position:0% +transformation for scalar field + + + align:start position:0% +transformation for scalar field +but now if you want you to Max the + + align:start position:0% +but now if you want you to Max the + + + align:start position:0% +but now if you want you to Max the +equation + + align:start position:0% +equation + + + align:start position:0% +equation +so we have to think about + + align:start position:0% +so we have to think about + + + align:start position:0% +so we have to think about +how this a mu transform under a lower + + align:start position:0% +how this a mu transform under a lower + + + align:start position:0% +how this a mu transform under a lower +end transformation and now a mu is a + + align:start position:0% +end transformation and now a mu is a + + + align:start position:0% +end transformation and now a mu is a +vector + + align:start position:0% +vector + + + align:start position:0% +vector +is a four Vector in the in space time + + align:start position:0% +is a four Vector in the in space time + + + align:start position:0% +is a four Vector in the in space time +okay and so + + align:start position:0% +okay and so + + + align:start position:0% +okay and so +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% +um + + + align:start position:0% +um +so that means that the uh uh a mu should + + align:start position:0% +so that means that the uh uh a mu should + + + align:start position:0% +so that means that the uh uh a mu should +uh transform also as the a vector okay + + align:start position:0% +uh transform also as the a vector okay + + + align:start position:0% +uh transform also as the a vector okay +so so this means that when you go to new + + align:start position:0% +so so this means that when you go to new + + + align:start position:0% +so so this means that when you go to new +frame + + align:start position:0% + + + + align:start position:0% + +a mu transform + + align:start position:0% +a mu transform + + + align:start position:0% +a mu transform +as Lambda mu Nu + + align:start position:0% +as Lambda mu Nu + + + align:start position:0% +as Lambda mu Nu +a new + + align:start position:0% +a new + + + align:start position:0% +a new +X okay + + align:start position:0% +X okay + + + align:start position:0% +X okay +so + + align:start position:0% +so + + + align:start position:0% +so +here not only so when a mu + + align:start position:0% +here not only so when a mu + + + align:start position:0% +here not only so when a mu +you evaluate the new position + + align:start position:0% +you evaluate the new position + + + align:start position:0% +you evaluate the new position +is can be written as a linear + + align:start position:0% +is can be written as a linear + + + align:start position:0% +is can be written as a linear +supervisition of the value at your + + align:start position:0% +supervisition of the value at your + + + align:start position:0% +supervisition of the value at your +original position + + align:start position:0% +original position + + + align:start position:0% +original position +and this linear position this linear + + align:start position:0% +and this linear position this linear + + + align:start position:0% +and this linear position this linear +superposition by itself is a low range + + align:start position:0% +superposition by itself is a low range + + + align:start position:0% +superposition by itself is a low range +transformation because a mu is a vector + + align:start position:0% +transformation because a mu is a vector + + + align:start position:0% +transformation because a mu is a vector +okay uh because mu is a vector + + align:start position:0% + + + + align:start position:0% + +that means just under Lauren + + align:start position:0% +that means just under Lauren + + + align:start position:0% +that means just under Lauren +transformation and the different + + align:start position:0% +transformation and the different + + + align:start position:0% +transformation and the different +components of a mu should also uh change + + align:start position:0% +components of a mu should also uh change + + + align:start position:0% +components of a mu should also uh change +under the transformation + + align:start position:0% +under the transformation + + + align:start position:0% +under the transformation +so so given this + + align:start position:0% +so so given this + + + align:start position:0% +so so given this +so I will not uh showed it now just I + + align:start position:0% +so I will not uh showed it now just I + + + align:start position:0% +so I will not uh showed it now just I +will + + align:start position:0% +will + + + align:start position:0% +will +take a couple minutes but you should + + align:start position:0% +take a couple minutes but you should + + + align:start position:0% +take a couple minutes but you should +convince yourself try to check yourself + + align:start position:0% +convince yourself try to check yourself + + + align:start position:0% +convince yourself try to check yourself +that the Maxwell equation which can be + + align:start position:0% +that the Maxwell equation which can be + + + align:start position:0% +that the Maxwell equation which can be +written so example as + + align:start position:0% +written so example as + + + align:start position:0% +written so example as +F mu mu Nu U equal to zero + + align:start position:0% +F mu mu Nu U equal to zero + + + align:start position:0% +F mu mu Nu U equal to zero +this implies + + align:start position:0% +this implies + + + align:start position:0% +this implies +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that the partial mu Prime in the new + + align:start position:0% +that the partial mu Prime in the new + + + align:start position:0% +that the partial mu Prime in the new +frame + + align:start position:0% +frame + + + align:start position:0% +frame +and then the F mu Prime + + align:start position:0% + + + + align:start position:0% + +fmu Prime is a a obtained from this new + + align:start position:0% +fmu Prime is a a obtained from this new + + + align:start position:0% +fmu Prime is a a obtained from this new +a new Prime + + align:start position:0% +a new Prime + + + align:start position:0% +a new Prime +and these two equations are the same + + align:start position:0% +and these two equations are the same + + + align:start position:0% +and these two equations are the same +okay uh equivalent just in one frame and + + align:start position:0% +okay uh equivalent just in one frame and + + + align:start position:0% +okay uh equivalent just in one frame and +then when you go to different frame and + + align:start position:0% +then when you go to different frame and + + + align:start position:0% +then when you go to different frame and +then you get this equation so equation + + align:start position:0% +then you get this equation so equation + + + align:start position:0% +then you get this equation so equation +will be exactly the same form okay but + + align:start position:0% +will be exactly the same form okay but + + + align:start position:0% +will be exactly the same form okay but +now it's in the new frame okay + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so now let's go to the Rock equation + + align:start position:0% +so now let's go to the Rock equation + + + align:start position:0% +so now let's go to the Rock equation +so now I've got a a go to the Rock + + align:start position:0% +so now I've got a a go to the Rock + + + align:start position:0% +so now I've got a a go to the Rock +equation + + align:start position:0% + + + + align:start position:0% + +again this side + + align:start position:0% +again this side + + + align:start position:0% +again this side +we need to ask how the size should + + align:start position:0% +we need to ask how the size should + + + align:start position:0% +we need to ask how the size should +transform + + align:start position:0% + + + + align:start position:0% + +underly range transformation okay + + align:start position:0% +underly range transformation okay + + + align:start position:0% +underly range transformation okay +but now this side is a completely new + + align:start position:0% +but now this side is a completely new + + + align:start position:0% +but now this side is a completely new +object + + align:start position:0% +object + + + align:start position:0% +object +so this is another it's not like in the + + align:start position:0% +so this is another it's not like in the + + + align:start position:0% +so this is another it's not like in the +in the Maxwell case below this is a + + align:start position:0% +in the Maxwell case below this is a + + + align:start position:0% +in the Maxwell case below this is a +space-time Vector so you can easily + + align:start position:0% +space-time Vector so you can easily + + + align:start position:0% +space-time Vector so you can easily +guess how you should transform okay + + align:start position:0% +guess how you should transform okay + + + align:start position:0% +guess how you should transform okay +so now this upside this spinner space is + + align:start position:0% +so now this upside this spinner space is + + + align:start position:0% +so now this upside this spinner space is +completely new okay so so now we have to + + align:start position:0% +completely new okay so so now we have to + + + align:start position:0% +completely new okay so so now we have to +figure out + + align:start position:0% +figure out + + + align:start position:0% +figure out +half side transform okay helps I + + align:start position:0% +half side transform okay helps I + + + align:start position:0% +half side transform okay helps I +transform + + align:start position:0% +transform + + + align:start position:0% +transform +so so let's suppose okay + + align:start position:0% + + + + align:start position:0% + +suppose + + align:start position:0% + + + + align:start position:0% + +under + + align:start position:0% + + + + align:start position:0% + +low range transformation namda + + align:start position:0% + + + + align:start position:0% + +negative PSI Transformer as follows + + align:start position:0% +negative PSI Transformer as follows + + + align:start position:0% +negative PSI Transformer as follows +PSI Prime + + align:start position:0% +PSI Prime + + + align:start position:0% +PSI Prime +alpha x Prime because now again you + + align:start position:0% +alpha x Prime because now again you + + + align:start position:0% +alpha x Prime because now again you +evaluate in the loop position new frame + + align:start position:0% +evaluate in the loop position new frame + + + align:start position:0% +evaluate in the loop position new frame +since this carrier index in principle + + align:start position:0% +since this carrier index in principle + + + align:start position:0% +since this carrier index in principle +this can be a superposition + + align:start position:0% + + + + align:start position:0% + +in the uh you can mix them in the + + align:start position:0% +in the uh you can mix them in the + + + align:start position:0% +in the uh you can mix them in the +internal space + + align:start position:0% + + + + align:start position:0% + +okay in principle we can have form like + + align:start position:0% +okay in principle we can have form like + + + align:start position:0% +okay in principle we can have form like +this + + align:start position:0% +this + + + align:start position:0% +this +say for some + + align:start position:0% +say for some + + + align:start position:0% +say for some +Matrix + + align:start position:0% + + + + align:start position:0% + +s + + align:start position:0% +s + + + align:start position:0% +s +okay which depends on Lambda okay + + align:start position:0% + + + + align:start position:0% + +so in principle + + align:start position:0% +so in principle + + + align:start position:0% +so in principle +you can have a transmission like this + + align:start position:0% +you can have a transmission like this + + + align:start position:0% +you can have a transmission like this +say say when you evaluate a new position + + align:start position:0% +say say when you evaluate a new position + + + align:start position:0% +say say when you evaluate a new position +it's given by the value at the old + + align:start position:0% +it's given by the value at the old + + + align:start position:0% +it's given by the value at the old +position but now you can make some + + align:start position:0% +position but now you can make some + + + align:start position:0% +position but now you can make some +rotations in the internal space + + align:start position:0% +rotations in the internal space + + + align:start position:0% +rotations in the internal space +just as here for the for the Maxwell + + align:start position:0% +just as here for the for the Maxwell + + + align:start position:0% +just as here for the for the Maxwell +field okay just as here for the max + + align:start position:0% +field okay just as here for the max + + + align:start position:0% +field okay just as here for the max +effect + + align:start position:0% +effect + + + align:start position:0% +effect +so accept + + align:start position:0% +so accept + + + align:start position:0% +so accept +and so suppose + + align:start position:0% + + + + align:start position:0% + +suppose this as for this and then our + + align:start position:0% +suppose this as for this and then our + + + align:start position:0% +suppose this as for this and then our +range covariance would be the statement + + align:start position:0% +range covariance would be the statement + + + align:start position:0% +range covariance would be the statement +say for some yeah for some + + align:start position:0% +say for some yeah for some + + + align:start position:0% +say for some yeah for some +Matrix + + align:start position:0% + + + + align:start position:0% + +and then the Lorenz cover incident is a + + align:start position:0% +and then the Lorenz cover incident is a + + + align:start position:0% +and then the Lorenz cover incident is a +statement + + align:start position:0% + + + + align:start position:0% + +is the statement starting from one + + align:start position:0% +is the statement starting from one + + + align:start position:0% +is the statement starting from one +from equation one + + align:start position:0% +from equation one + + + align:start position:0% +from equation one +you should be able to find go into the + + align:start position:0% +you should be able to find go into the + + + align:start position:0% +you should be able to find go into the +new frame + + align:start position:0% +new frame + + + align:start position:0% +new frame +you have a equation like this gamma mu + + align:start position:0% +you have a equation like this gamma mu + + + align:start position:0% +you have a equation like this gamma mu +partial mu Prime + + align:start position:0% +partial mu Prime + + + align:start position:0% +partial mu Prime +minus m + + align:start position:0% +minus m + + + align:start position:0% +minus m +PSI Prime + + align:start position:0% +PSI Prime + + + align:start position:0% +PSI Prime +X Prime equal to zero + + align:start position:0% +X Prime equal to zero + + + align:start position:0% +X Prime equal to zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you should get a identical equation + + align:start position:0% +so you should get a identical equation + + + align:start position:0% +so you should get a identical equation +not an electrical equation two you + + align:start position:0% +not an electrical equation two you + + + align:start position:0% +not an electrical equation two you +should get the identical equation but + + align:start position:0% +should get the identical equation but + + + align:start position:0% +should get the identical equation but +now everything is in terms of prime + + align:start position:0% +now everything is in terms of prime + + + align:start position:0% +now everything is in terms of prime +okay everything in terms of prime + + align:start position:0% +okay everything in terms of prime + + + align:start position:0% +okay everything in terms of prime +so so why say emphasize the gamma mu + + align:start position:0% +so so why say emphasize the gamma mu + + + align:start position:0% +so so why say emphasize the gamma mu +does not change despite a carry index mu + + align:start position:0% +does not change despite a carry index mu + + + align:start position:0% +does not change despite a carry index mu +will gamma mu just some + + align:start position:0% +will gamma mu just some + + + align:start position:0% +will gamma mu just some +constant matrices okay to see it's a + + align:start position:0% +constant matrices okay to see it's a + + + align:start position:0% +constant matrices okay to see it's a +it's a it's just four matrices uh it + + align:start position:0% +it's a it's just four matrices uh it + + + align:start position:0% +it's a it's just four matrices uh it +does not transform under any space time + + align:start position:0% +does not transform under any space time + + + align:start position:0% +does not transform under any space time +chance it it's not dynamical variable it + + align:start position:0% +chance it it's not dynamical variable it + + + align:start position:0% +chance it it's not dynamical variable it +does not transform on the space-time + + align:start position:0% +does not transform on the space-time + + + align:start position:0% +does not transform on the space-time +transmission so so gamma mu does not + + align:start position:0% +transmission so so gamma mu does not + + + align:start position:0% +transmission so so gamma mu does not +change okay + + align:start position:0% +change okay + + + align:start position:0% +change okay +good so now the question + + align:start position:0% +good so now the question + + + align:start position:0% +good so now the question +of the Lorenz covariance where the drug + + align:start position:0% +of the Lorenz covariance where the drug + + + align:start position:0% +of the Lorenz covariance where the drug +equation is Lorenz coherent volume + + align:start position:0% +equation is Lorenz coherent volume + + + align:start position:0% +equation is Lorenz coherent volume +okay whether we can find the such s okay + + align:start position:0% +okay whether we can find the such s okay + + + align:start position:0% +okay whether we can find the such s okay +which the weather + + align:start position:0% +which the weather + + + align:start position:0% +which the weather +yeah the questions can we find + + align:start position:0% + + + + align:start position:0% + +such an s + + align:start position:0% +such an s + + + align:start position:0% +such an s +okay so if you can find such a s + + align:start position:0% +okay so if you can find such a s + + + align:start position:0% +okay so if you can find such a s +which this is true + + align:start position:0% + + + + align:start position:0% + +then we say the direct equation is + + align:start position:0% +then we say the direct equation is + + + align:start position:0% +then we say the direct equation is +Lorenz covarent + + align:start position:0% +Lorenz covarent + + + align:start position:0% +Lorenz covarent +and uh and this is how the Rock field + + align:start position:0% +and uh and this is how the Rock field + + + align:start position:0% +and uh and this is how the Rock field +should transform okay so this side is + + align:start position:0% +should transform okay so this side is + + + align:start position:0% +should transform okay so this side is +normally called the direct field okay + + align:start position:0% +normally called the direct field okay + + + align:start position:0% +normally called the direct field okay +and this is how the rock field should + + align:start position:0% +and this is how the rock field should + + + align:start position:0% +and this is how the rock field should +transform so so PSI is often called The + + align:start position:0% +transform so so PSI is often called The + + + align:start position:0% +transform so so PSI is often called The +Rock field it's also often called + + align:start position:0% +Rock field it's also often called + + + align:start position:0% +Rock field it's also often called +spinner field okay and uh it's often + + align:start position:0% +spinner field okay and uh it's often + + + align:start position:0% +spinner field okay and uh it's often +it's also often called The Rock spin the + + align:start position:0% +it's also often called The Rock spin the + + + align:start position:0% +it's also often called The Rock spin the +field and uh anyway and then that should + + align:start position:0% +field and uh anyway and then that should + + + align:start position:0% +field and uh anyway and then that should +be the way high is transformed okay + + align:start position:0% +be the way high is transformed okay + + + align:start position:0% +be the way high is transformed okay +yes + + align:start position:0% + + + + align:start position:0% + +yeah no no in this case + + align:start position:0% +yeah no no in this case + + + align:start position:0% +yeah no no in this case +so we will when you talk about transform + + align:start position:0% +so we will when you talk about transform + + + align:start position:0% +so we will when you talk about transform +over the scalar field itself of course + + align:start position:0% +over the scalar field itself of course + + + align:start position:0% +over the scalar field itself of course +it's just Phi go to Five Prime + + align:start position:0% +it's just Phi go to Five Prime + + + align:start position:0% +it's just Phi go to Five Prime +and uh because that function changes + + align:start position:0% +and uh because that function changes + + + align:start position:0% +and uh because that function changes +okay that function changes but here we + + align:start position:0% +okay that function changes but here we + + + align:start position:0% +okay that function changes but here we +are asking uh about the form of the + + align:start position:0% +are asking uh about the form of the + + + align:start position:0% +are asking uh about the form of the +equation in the new frame + + align:start position:0% +equation in the new frame + + + align:start position:0% +equation in the new frame +and so so when you go to the new frame + + align:start position:0% +and so so when you go to the new frame + + + align:start position:0% +and so so when you go to the new frame +your function form change but your + + align:start position:0% +your function form change but your + + + align:start position:0% +your function form change but your +coordinate also change so that's why you + + align:start position:0% +coordinate also change so that's why you + + + align:start position:0% +coordinate also change so that's why you +need to when we say the covariance you + + align:start position:0% +need to when we say the covariance you + + + align:start position:0% +need to when we say the covariance you +need to evaluate your new function in + + align:start position:0% +need to evaluate your new function in + + + align:start position:0% +need to evaluate your new function in +the new position yeah yeah yeah that + + align:start position:0% +the new position yeah yeah yeah that + + + align:start position:0% +the new position yeah yeah yeah that +means they look the same in different + + align:start position:0% +means they look the same in different + + + align:start position:0% +means they look the same in different +frame yeah + + align:start position:0% +frame yeah + + + align:start position:0% +frame yeah +yes + + align:start position:0% + + + + align:start position:0% + +yeah exactly good good exactly that's + + align:start position:0% +yeah exactly good good exactly that's + + + align:start position:0% +yeah exactly good good exactly that's +the that's exactly the right + + align:start position:0% +the that's exactly the right + + + align:start position:0% +the that's exactly the right +mathematical language uh to talk about + + align:start position:0% +mathematical language uh to talk about + + + align:start position:0% +mathematical language uh to talk about +this which we will mention later uh at + + align:start position:0% +this which we will mention later uh at + + + align:start position:0% +this which we will mention later uh at +the moment I didn't want to use + + align:start position:0% +the moment I didn't want to use + + + align:start position:0% +the moment I didn't want to use +mathematical language yeah yeah for + + align:start position:0% +mathematical language yeah yeah for + + + align:start position:0% +mathematical language yeah yeah for +those people who are familiar with group + + align:start position:0% +those people who are familiar with group + + + align:start position:0% +those people who are familiar with group +Theory indeed so this s would be the + + align:start position:0% +Theory indeed so this s would be the + + + align:start position:0% +Theory indeed so this s would be the +representation of the lorentz group in + + align:start position:0% +representation of the lorentz group in + + + align:start position:0% +representation of the lorentz group in +the uh in the spinner space + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +okay so now let's try to find this s + + align:start position:0% +okay so now let's try to find this s + + + align:start position:0% +okay so now let's try to find this s +okay + + align:start position:0% + + + + align:start position:0% + +so before do that let's first + + align:start position:0% +so before do that let's first + + + align:start position:0% +so before do that let's first +write what is a partial Prime X mu so + + align:start position:0% +write what is a partial Prime X mu so + + + align:start position:0% +write what is a partial Prime X mu so +recall + + align:start position:0% +recall + + + align:start position:0% +recall +partial Prime mu + + align:start position:0% +partial Prime mu + + + align:start position:0% +partial Prime mu +it should be partial partial X Prime mu + + align:start position:0% +it should be partial partial X Prime mu + + + align:start position:0% +it should be partial partial X Prime mu +this transform the new coordinates and + + align:start position:0% +this transform the new coordinates and + + + align:start position:0% +this transform the new coordinates and +from that transformation you can easily + + align:start position:0% +from that transformation you can easily + + + align:start position:0% +from that transformation you can easily +figure it out just chain rule so this is + + align:start position:0% +figure it out just chain rule so this is + + + align:start position:0% +figure it out just chain rule so this is +the same + + align:start position:0% +the same + + + align:start position:0% +the same +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +partial + + align:start position:0% +partial + + + align:start position:0% +partial +partial X mu + + align:start position:0% + + + + align:start position:0% + +and Lambda minus one + + align:start position:0% +and Lambda minus one + + + align:start position:0% +and Lambda minus one +new mu okay + + align:start position:0% +new mu okay + + + align:start position:0% +new mu okay +okay so this is very easy to figure it + + align:start position:0% +okay so this is very easy to figure it + + + align:start position:0% +okay so this is very easy to figure it +out because the uh because they have to + + align:start position:0% +out because the uh because they have to + + + align:start position:0% +out because the uh because they have to +be uh the X will multiply the X the + + align:start position:0% +be uh the X will multiply the X the + + + align:start position:0% +be uh the X will multiply the X the +pressure X will have to be a singlet so + + align:start position:0% +pressure X will have to be a singlet so + + + align:start position:0% +pressure X will have to be a singlet so +so this transform has an inverse Matrix + + align:start position:0% +so this transform has an inverse Matrix + + + align:start position:0% +so this transform has an inverse Matrix +so this implies + + align:start position:0% +so this implies + + + align:start position:0% +so this implies +that the gamma mu + + align:start position:0% +that the gamma mu + + + align:start position:0% +that the gamma mu +partial mu Prime should be equal to + + align:start position:0% +partial mu Prime should be equal to + + + align:start position:0% +partial mu Prime should be equal to +Lambda minus 1 + + align:start position:0% +Lambda minus 1 + + + align:start position:0% +Lambda minus 1 +new mu + + align:start position:0% +new mu + + + align:start position:0% +new mu +comma + + align:start position:0% +comma + + + align:start position:0% +comma +mu pi to Nu okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so with this preparation then we can try + + align:start position:0% +so with this preparation then we can try + + + align:start position:0% +so with this preparation then we can try +to uh try to see whether we can find s + + align:start position:0% +to uh try to see whether we can find s + + + align:start position:0% +to uh try to see whether we can find s +from this equation okay + + align:start position:0% +from this equation okay + + + align:start position:0% +from this equation okay +no yeah I find this equation from what + + align:start position:0% +no yeah I find this equation from what + + + align:start position:0% +no yeah I find this equation from what +so what we can do is that let's multiply + + align:start position:0% +so what we can do is that let's multiply + + + align:start position:0% +so what we can do is that let's multiply +the equation one from the left by S okay + + align:start position:0% +the equation one from the left by S okay + + + align:start position:0% +the equation one from the left by S okay +so let's imagine we + + align:start position:0% +so let's imagine we + + + align:start position:0% +so let's imagine we +multiply s such a matrix again I always + + align:start position:0% +multiply s such a matrix again I always + + + align:start position:0% +multiply s such a matrix again I always +just suppress the spin the indices and + + align:start position:0% +just suppress the spin the indices and + + + align:start position:0% +just suppress the spin the indices and +just write in The Matrix form + + align:start position:0% +just write in The Matrix form + + + align:start position:0% +just write in The Matrix form +so let's just write gamma mu + + align:start position:0% +so let's just write gamma mu + + + align:start position:0% +so let's just write gamma mu +to take that equation 1 + + align:start position:0% +to take that equation 1 + + + align:start position:0% +to take that equation 1 +we multiply by S + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +so we have two terms here so this is a + + align:start position:0% +so we have two terms here so this is a + + + align:start position:0% +so we have two terms here so this is a +matrix in the same space as s okay s act + + align:start position:0% +matrix in the same space as s okay s act + + + align:start position:0% +matrix in the same space as s okay s act +in the same space as gamma mu so so we + + align:start position:0% +in the same space as gamma mu so so we + + + align:start position:0% +in the same space as gamma mu so so we +cannot easily commute here okay uh they + + align:start position:0% +cannot easily commute here okay uh they + + + align:start position:0% +cannot easily commute here okay uh they +normally they don't compute + + align:start position:0% +normally they don't compute + + + align:start position:0% +normally they don't compute +but this but m is a constant so we can + + align:start position:0% +but this but m is a constant so we can + + + align:start position:0% +but this but m is a constant so we can +pass s through here okay we can pass + + align:start position:0% +pass s through here okay we can pass + + + align:start position:0% +pass s through here okay we can pass +through S here so we can rewrite this + + align:start position:0% +through S here so we can rewrite this + + + align:start position:0% +through S here so we can rewrite this +equation as follows + + align:start position:0% +equation as follows + + + align:start position:0% +equation as follows +we can write it as s gamma mu + + align:start position:0% +we can write it as s gamma mu + + + align:start position:0% +we can write it as s gamma mu +s minus 1 + + align:start position:0% +s minus 1 + + + align:start position:0% +s minus 1 +mu minus m + + align:start position:0% + + + + align:start position:0% + +s PSI zero okay + + align:start position:0% +s PSI zero okay + + + align:start position:0% +s PSI zero okay +so so for M + + align:start position:0% +so so for M + + + align:start position:0% +so so for M +I just passed s through through but for + + align:start position:0% +I just passed s through through but for + + + align:start position:0% +I just passed s through through but for +this term I just inserted s minus 1 and + + align:start position:0% +this term I just inserted s minus 1 and + + + align:start position:0% +this term I just inserted s minus 1 and +S and so yeah it's the same okay + + align:start position:0% + + + + align:start position:0% + +so now we can use this equation + + align:start position:0% + + + + align:start position:0% + +in here okay because s times PSI just + + align:start position:0% +in here okay because s times PSI just + + + align:start position:0% +in here okay because s times PSI just +equal to psi Prime + + align:start position:0% +equal to psi Prime + + + align:start position:0% +equal to psi Prime +X Prime okay so now we get + + align:start position:0% +X Prime okay so now we get + + + align:start position:0% +X Prime okay so now we get +s comma mu + + align:start position:0% +s comma mu + + + align:start position:0% +s comma mu +s minus one partial mu minus m + + align:start position:0% +s minus one partial mu minus m + + + align:start position:0% +s minus one partial mu minus m +PSI Prime X Prime + + align:start position:0% +PSI Prime X Prime + + + align:start position:0% +PSI Prime X Prime +equal to zero okay we just use that + + align:start position:0% +equal to zero okay we just use that + + + align:start position:0% +equal to zero okay we just use that +equation + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yeah yeah so that's the key I'm + + align:start position:0% +yeah yeah so that's the key I'm + + + align:start position:0% +yeah yeah so that's the key I'm +emphasized earlier so so X mu and PSI + + align:start position:0% +emphasized earlier so so X mu and PSI + + + align:start position:0% +emphasized earlier so so X mu and PSI +Alpha there in different space + + align:start position:0% +Alpha there in different space + + + align:start position:0% +Alpha there in different space +so so oh this s and the gamma they're + + align:start position:0% +so so oh this s and the gamma they're + + + align:start position:0% +so so oh this s and the gamma they're +all constant they don't depend on + + align:start position:0% +all constant they don't depend on + + + align:start position:0% +all constant they don't depend on +spatial location + + align:start position:0% +spatial location + + + align:start position:0% +spatial location +and so so partial mu does not act on S + + align:start position:0% +and so so partial mu does not act on S + + + align:start position:0% +and so so partial mu does not act on S +yeah for pi mu point B S is just a + + align:start position:0% +yeah for pi mu point B S is just a + + + align:start position:0% +yeah for pi mu point B S is just a +constant it's a space-time constant it + + align:start position:0% +constant it's a space-time constant it + + + align:start position:0% +constant it's a space-time constant it +only rotates it it only rotates say at + + align:start position:0% +only rotates it it only rotates say at + + + align:start position:0% +only rotates it it only rotates say at +the single point + + align:start position:0% +the single point + + + align:start position:0% +the single point +a different component of PSI at the + + align:start position:0% +a different component of PSI at the + + + align:start position:0% +a different component of PSI at the +single point + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +okay so now we have this equation + + align:start position:0% +okay so now we have this equation + + + align:start position:0% +okay so now we have this equation +so now we can compare + + align:start position:0% +so now we can compare + + + align:start position:0% +so now we can compare +this + + align:start position:0% +this + + + align:start position:0% +this +object with this object + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yeah in particular this object is equal + + align:start position:0% +yeah in particular this object is equal + + + align:start position:0% +yeah in particular this object is equal +to that + + align:start position:0% +to that + + + align:start position:0% +to that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so we conclude that one goes to two + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +s comma mu + + align:start position:0% +s comma mu + + + align:start position:0% +s comma mu +s minus 1 equal to + + align:start position:0% +s minus 1 equal to + + + align:start position:0% +s minus 1 equal to +this object + + align:start position:0% +this object + + + align:start position:0% +this object +Lambda minus one + + align:start position:0% + + + + align:start position:0% + +new mu + + align:start position:0% +new mu + + + align:start position:0% +new mu +I think + + align:start position:0% +I think + + + align:start position:0% +I think +yeah I think I'm messing up a little bit + + align:start position:0% +yeah I think I'm messing up a little bit + + + align:start position:0% +yeah I think I'm messing up a little bit +notation here uh gamma mu + + align:start position:0% +notation here uh gamma mu + + + align:start position:0% +notation here uh gamma mu +I think my index is a little bit wrong + + align:start position:0% +I think my index is a little bit wrong + + + align:start position:0% +I think my index is a little bit wrong +let me just make sure + + align:start position:0% +let me just make sure + + + align:start position:0% +let me just make sure +oh yeah yeah here is a partial new sorry + + align:start position:0% +oh yeah yeah here is a partial new sorry + + + align:start position:0% +oh yeah yeah here is a partial new sorry +here is partial news I need to exchange + + align:start position:0% +here is partial news I need to exchange + + + align:start position:0% +here is partial news I need to exchange +the MU and the new index here so + + align:start position:0% + + + + align:start position:0% + +new + + align:start position:0% +new + + + align:start position:0% +new +then + + align:start position:0% +then + + + align:start position:0% +then +comma + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so so this has to be equal to that + + align:start position:0% +so so so this has to be equal to that + + + align:start position:0% +so so so this has to be equal to that +okay so this has to be equal to that and + + align:start position:0% +okay so this has to be equal to that and + + + align:start position:0% +okay so this has to be equal to that and +you need to uh to compare partial new + + align:start position:0% +you need to uh to compare partial new + + + align:start position:0% +you need to uh to compare partial new +with partial mu we have to exchange the + + align:start position:0% +with partial mu we have to exchange the + + + align:start position:0% +with partial mu we have to exchange the +new and new here anyway so so this is + + align:start position:0% +new and new here anyway so so this is + + + align:start position:0% +new and new here anyway so so this is +the equation we have to satisfy + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so we have to find a matrix as + + align:start position:0% +so we have to find a matrix as + + + align:start position:0% +so we have to find a matrix as +which act on gamma mu + + align:start position:0% + + + + align:start position:0% + +gamma mu is some function of H matrices + + align:start position:0% +gamma mu is some function of H matrices + + + align:start position:0% +gamma mu is some function of H matrices +and give you + + align:start position:0% +and give you + + + align:start position:0% +and give you +like this so as if the gamma mu actually + + align:start position:0% +like this so as if the gamma mu actually + + + align:start position:0% +like this so as if the gamma mu actually +when you ask about S as as if gamma mu + + align:start position:0% +when you ask about S as as if gamma mu + + + align:start position:0% +when you ask about S as as if gamma mu +transformed as some low range + + align:start position:0% +transformed as some low range + + + align:start position:0% +transformed as some low range +transformation okay yeah inverse romance + + align:start position:0% +transformation okay yeah inverse romance + + + align:start position:0% +transformation okay yeah inverse romance +transformation + + align:start position:0% + + + + align:start position:0% + +so so we need to now let's try to find + + align:start position:0% +so so we need to now let's try to find + + + align:start position:0% +so so we need to now let's try to find +this as + + align:start position:0% +this as + + + align:start position:0% +this as +so so to do this we again we use a trick + + align:start position:0% +so so to do this we again we use a trick + + + align:start position:0% +so so to do this we again we use a trick +which uh we have been using before + + align:start position:0% +which uh we have been using before + + + align:start position:0% +which uh we have been using before +so so how would you approach this + + align:start position:0% +so so how would you approach this + + + align:start position:0% +so so how would you approach this +problem + + align:start position:0% + + + + align:start position:0% + +good good yes yes just do a infinite + + align:start position:0% +good good yes yes just do a infinite + + + align:start position:0% +good good yes yes just do a infinite +test mode Transformations okay so once + + align:start position:0% +test mode Transformations okay so once + + + align:start position:0% +test mode Transformations okay so once +you learn how to do infinite test mode + + align:start position:0% +you learn how to do infinite test mode + + + align:start position:0% +you learn how to do infinite test mode +Transformations then you always know how + + align:start position:0% +Transformations then you always know how + + + align:start position:0% +Transformations then you always know how +to do finite once and if any decimal + + align:start position:0% +to do finite once and if any decimal + + + align:start position:0% +to do finite once and if any decimal +ones it's much much easier to do okay + + align:start position:0% +ones it's much much easier to do okay + + + align:start position:0% +ones it's much much easier to do okay +so now again we consider + + align:start position:0% +so now again we consider + + + align:start position:0% +so now again we consider +[Applause] + + align:start position:0% + + + + align:start position:0% + +them the new new + + align:start position:0% + + + + align:start position:0% + +close to Identity + + align:start position:0% + + + + align:start position:0% + +okay so that means + + align:start position:0% +okay so that means + + + align:start position:0% +okay so that means +we write Lambda mu + + align:start position:0% + + + + align:start position:0% + +and stealtham mu Nu + + align:start position:0% + + + + align:start position:0% + +which is the identity + + align:start position:0% +which is the identity + + + align:start position:0% +which is the identity +then plus + + align:start position:0% +then plus + + + align:start position:0% +then plus +Omega mu Nu + + align:start position:0% +Omega mu Nu + + + align:start position:0% +Omega mu Nu +and take the Omega to be small okay and + + align:start position:0% +and take the Omega to be small okay and + + + align:start position:0% +and take the Omega to be small okay and +also remember previously we discussed + + align:start position:0% +also remember previously we discussed + + + align:start position:0% +also remember previously we discussed +that Omega mu mu when you know the index + + align:start position:0% +that Omega mu mu when you know the index + + + align:start position:0% +that Omega mu mu when you know the index +is actually anti-symmetric + + align:start position:0% +is actually anti-symmetric + + + align:start position:0% +is actually anti-symmetric +okay + + align:start position:0% + + + + align:start position:0% + +so so and this is infinitesimal so we + + align:start position:0% +so so and this is infinitesimal so we + + + align:start position:0% +so so and this is infinitesimal so we +take this to be infinitesimal and work + + align:start position:0% +take this to be infinitesimal and work + + + align:start position:0% +take this to be infinitesimal and work +everything to first order in Omega okay + + align:start position:0% +everything to first order in Omega okay + + + align:start position:0% +everything to first order in Omega okay +uh work everything uh the first order + + align:start position:0% +uh work everything uh the first order + + + align:start position:0% +uh work everything uh the first order +so similarly the Lambda minus + + align:start position:0% +so similarly the Lambda minus + + + align:start position:0% +so similarly the Lambda minus +we knew + + align:start position:0% + + + + align:start position:0% + +just equal to data menu + + align:start position:0% +just equal to data menu + + + align:start position:0% +just equal to data menu +just give you my minus Omega + + align:start position:0% +just give you my minus Omega + + + align:start position:0% +just give you my minus Omega +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so yeah just to to Leading order in + + align:start position:0% +so so yeah just to to Leading order in + + + align:start position:0% +so so yeah just to to Leading order in +Omega expansion the inverse metric is + + align:start position:0% +Omega expansion the inverse metric is + + + align:start position:0% +Omega expansion the inverse metric is +just given by that + + align:start position:0% + + + + align:start position:0% + +so now we can try to so + + align:start position:0% +so now we can try to so + + + align:start position:0% +so now we can try to so +so since the s + + align:start position:0% + + + + align:start position:0% + +so on the right hand side + + align:start position:0% +so on the right hand side + + + align:start position:0% +so on the right hand side +when when Lambda is close to the + + align:start position:0% +when when Lambda is close to the + + + align:start position:0% +when when Lambda is close to the +identity + + align:start position:0% +identity + + + align:start position:0% +identity +okay so uh uh uh so the right hand side + + align:start position:0% +okay so uh uh uh so the right hand side + + + align:start position:0% +okay so uh uh uh so the right hand side +is just the gamma mu okay just the + + align:start position:0% +is just the gamma mu okay just the + + + align:start position:0% +is just the gamma mu okay just the +identity does not do anything just + + align:start position:0% +identity does not do anything just + + + align:start position:0% +identity does not do anything just +common mu and then plus something + + align:start position:0% +common mu and then plus something + + + align:start position:0% +common mu and then plus something +proportion to Omega okay then that means + + align:start position:0% +proportion to Omega okay then that means + + + align:start position:0% +proportion to Omega okay then that means +that s + + align:start position:0% +that s + + + align:start position:0% +that s +must also have a a number is close to + + align:start position:0% +must also have a a number is close to + + + align:start position:0% +must also have a a number is close to +Identity means s must also have the + + align:start position:0% +Identity means s must also have the + + + align:start position:0% +Identity means s must also have the +structure to be identity and + + align:start position:0% +structure to be identity and + + + align:start position:0% +structure to be identity and +proportional to something linear in + + align:start position:0% +proportional to something linear in + + + align:start position:0% +proportional to something linear in +Omega okay so so the so the S must also + + align:start position:0% +Omega okay so so the so the S must also + + + align:start position:0% +Omega okay so so the so the S must also +have this structure + + align:start position:0% + + + + align:start position:0% + +yeah let me just don't write the index + + align:start position:0% +yeah let me just don't write the index + + + align:start position:0% +yeah let me just don't write the index +just a direction right as identity + + align:start position:0% + + + + align:start position:0% + +and then it should be something + + align:start position:0% +and then it should be something + + + align:start position:0% +and then it should be something +proportional to Omega okay + + align:start position:0% +proportional to Omega okay + + + align:start position:0% +proportional to Omega okay +so so from convention we write this way + + align:start position:0% +so so from convention we write this way + + + align:start position:0% +so so from convention we write this way +so it should be leading Omega mu and + + align:start position:0% +so it should be leading Omega mu and + + + align:start position:0% +so it should be leading Omega mu and +sigma + + align:start position:0% +sigma + + + align:start position:0% +sigma +so Sigma Mia are a bunch of matrices + + align:start position:0% +so Sigma Mia are a bunch of matrices + + + align:start position:0% +so Sigma Mia are a bunch of matrices +okay so remember s is a four by four + + align:start position:0% +okay so remember s is a four by four + + + align:start position:0% +okay so remember s is a four by four +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +and so so Omega menu just some number + + align:start position:0% +and so so Omega menu just some number + + + align:start position:0% +and so so Omega menu just some number +okay just some number so so this will be + + align:start position:0% +okay just some number so so this will be + + + align:start position:0% +okay just some number so so this will be +a bunch of uh four by four matrices so + + align:start position:0% +a bunch of uh four by four matrices so + + + align:start position:0% +a bunch of uh four by four matrices so +from each Omega I can in principle uh + + align:start position:0% +from each Omega I can in principle uh + + + align:start position:0% +from each Omega I can in principle uh +independently uh uh uh multiplies on + + align:start position:0% +independently uh uh uh multiplies on + + + align:start position:0% +independently uh uh uh multiplies on +Matrix okay so this is the most General + + align:start position:0% +Matrix okay so this is the most General + + + align:start position:0% +Matrix okay so this is the most General +way to Pro to expand this linear order + + align:start position:0% +way to Pro to expand this linear order + + + align:start position:0% +way to Pro to expand this linear order +in Omega okay so so this Sigma + + align:start position:0% +in Omega okay so so this Sigma + + + align:start position:0% +in Omega okay so so this Sigma +essentially just the first derivative of + + align:start position:0% +essentially just the first derivative of + + + align:start position:0% +essentially just the first derivative of +s respect to each Omega okay + + align:start position:0% +s respect to each Omega okay + + + align:start position:0% +s respect to each Omega okay +and this I over 2 is just convention + + align:start position:0% +and this I over 2 is just convention + + + align:start position:0% +and this I over 2 is just convention +and similarly + + align:start position:0% + + + + align:start position:0% + +the inverse is just corresponding you + + align:start position:0% +the inverse is just corresponding you + + + align:start position:0% +the inverse is just corresponding you +change the sign here to Leading mode in + + align:start position:0% +change the sign here to Leading mode in + + + align:start position:0% +change the sign here to Leading mode in +Omega + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so okay so I emphasize each signal mu + + align:start position:0% +so okay so I emphasize each signal mu + + + align:start position:0% +so okay so I emphasize each signal mu +is a matrix okay it should be understood + + align:start position:0% +is a matrix okay it should be understood + + + align:start position:0% +is a matrix okay it should be understood +as + + align:start position:0% + + + + align:start position:0% + +some Matrix + + align:start position:0% +some Matrix + + + align:start position:0% +some Matrix +okay + + align:start position:0% +okay + + + align:start position:0% +okay +in the in the spinner space + + align:start position:0% + + + + align:start position:0% + +okay so now you just need to plug in + + align:start position:0% +okay so now you just need to plug in + + + align:start position:0% +okay so now you just need to plug in +this equation + + align:start position:0% +this equation + + + align:start position:0% +this equation +plug in this s + + align:start position:0% +plug in this s + + + align:start position:0% +plug in this s +and S minus y into this equation yeah + + align:start position:0% +and S minus y into this equation yeah + + + align:start position:0% +and S minus y into this equation yeah +just expand the both sides to all the + + align:start position:0% +just expand the both sides to all the + + + align:start position:0% +just expand the both sides to all the +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +okay and you equate the coefficient + + align:start position:0% +okay and you equate the coefficient + + + align:start position:0% +okay and you equate the coefficient +you create the coefficient from that way + + align:start position:0% +you create the coefficient from that way + + + align:start position:0% +you create the coefficient from that way +you determine the sigma okay + + align:start position:0% +you determine the sigma okay + + + align:start position:0% +you determine the sigma okay +so so let me call this equation star + + align:start position:0% +so so let me call this equation star + + + align:start position:0% +so so let me call this equation star +let me just call this question three + + align:start position:0% +let me just call this question three + + + align:start position:0% +let me just call this question three +so + + align:start position:0% +so + + + align:start position:0% +so +um then Q order + + align:start position:0% + + + + align:start position:0% + +Omega mu mu to linear order + + align:start position:0% + + + + align:start position:0% + +then then equation three + + align:start position:0% +then then equation three + + + align:start position:0% +then then equation three +if when you expand on both sides to + + align:start position:0% +if when you expand on both sides to + + + align:start position:0% +if when you expand on both sides to +Omega to all the Omega and equate both + + align:start position:0% +Omega to all the Omega and equate both + + + align:start position:0% +Omega to all the Omega and equate both +sides then you find the following + + align:start position:0% +sides then you find the following + + + align:start position:0% +sides then you find the following +equation this is just a couple of lines + + align:start position:0% +equation this is just a couple of lines + + + align:start position:0% +equation this is just a couple of lines +algebra so I urge you to do it yourself + + align:start position:0% +algebra so I urge you to do it yourself + + + align:start position:0% +algebra so I urge you to do it yourself +so given by I + + align:start position:0% +so given by I + + + align:start position:0% +so given by I +commutator + + align:start position:0% + + + + align:start position:0% + +Lambda row + + align:start position:0% + + + + align:start position:0% + +common view + + align:start position:0% +common view + + + align:start position:0% +common view +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +ETA named the MU + + align:start position:0% +ETA named the MU + + + align:start position:0% +ETA named the MU +gamma rho + + align:start position:0% +gamma rho + + + align:start position:0% +gamma rho +Madness + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so you get this equation so the left + + align:start position:0% +so you get this equation so the left + + + align:start position:0% +so you get this equation so the left +hand side is very easy to understand + + align:start position:0% +hand side is very easy to understand + + + align:start position:0% +hand side is very easy to understand +so essentially you just + + align:start position:0% +so essentially you just + + + align:start position:0% +so essentially you just +whenever you have a commutator + + align:start position:0% +whenever you have a commutator + + + align:start position:0% +whenever you have a commutator +for people have done this a a baker + + align:start position:0% +for people have done this a a baker + + + align:start position:0% +for people have done this a a baker +house Stuff Etc the first of all the + + align:start position:0% +house Stuff Etc the first of all the + + + align:start position:0% +house Stuff Etc the first of all the +u.sk the commutator okay I always get + + align:start position:0% +u.sk the commutator okay I always get + + + align:start position:0% +u.sk the commutator okay I always get +the commented so that's where this + + align:start position:0% +the commented so that's where this + + + align:start position:0% +the commented so that's where this +commentator come from + + align:start position:0% +commentator come from + + + align:start position:0% +commentator come from +so the right hand side when you expand + + align:start position:0% +so the right hand side when you expand + + + align:start position:0% +so the right hand side when you expand +this it essentially just get + + align:start position:0% + + + + align:start position:0% + +Omega mu mu because we have to lower the + + align:start position:0% +Omega mu mu because we have to lower the + + + align:start position:0% +Omega mu mu because we have to lower the +indices okay so so you have some ETA + + align:start position:0% +indices okay so so you have some ETA + + + align:start position:0% +indices okay so so you have some ETA +here + + align:start position:0% +here + + + align:start position:0% +here +okay you have ETA here and yeah yeah so + + align:start position:0% +okay you have ETA here and yeah yeah so + + + align:start position:0% +okay you have ETA here and yeah yeah so +that's how you get the right hand side + + align:start position:0% +that's how you get the right hand side + + + align:start position:0% +that's how you get the right hand side +okay and the reason you get two terms + + align:start position:0% +okay and the reason you get two terms + + + align:start position:0% +okay and the reason you get two terms +because it should be anti-symmetric uh + + align:start position:0% +because it should be anti-symmetric uh + + + align:start position:0% +because it should be anti-symmetric uh +in the uh uh yeah + + align:start position:0% + + + + align:start position:0% + +good so now just for your stand to solve + + align:start position:0% +good so now just for your stand to solve + + + align:start position:0% +good so now just for your stand to solve +this equation + + align:start position:0% +this equation + + + align:start position:0% +this equation +so if you can find Sigma + + align:start position:0% +so if you can find Sigma + + + align:start position:0% +so if you can find Sigma +satisfy this equation + + align:start position:0% +satisfy this equation + + + align:start position:0% +satisfy this equation +and and then then we are done + + align:start position:0% +and and then then we are done + + + align:start position:0% +and and then then we are done +okay and then we are done + + align:start position:0% +okay and then we are done + + + align:start position:0% +okay and then we are done +so so yeah of course this is a um + + align:start position:0% +so so yeah of course this is a um + + + align:start position:0% +so so yeah of course this is a um +and now you + + align:start position:0% +and now you + + + align:start position:0% +and now you +you do it by trial and arrow okay now + + align:start position:0% +you do it by trial and arrow okay now + + + align:start position:0% +you do it by trial and arrow okay now +you do by child narrow and uh um + + align:start position:0% +you do by child narrow and uh um + + + align:start position:0% +you do by child narrow and uh um +the bottom line is that there's a + + align:start position:0% +the bottom line is that there's a + + + align:start position:0% +the bottom line is that there's a +solution okay so let me just write down + + align:start position:0% +solution okay so let me just write down + + + align:start position:0% +solution okay so let me just write down +the solution and uh + + align:start position:0% + + + + align:start position:0% + +the nice thing about the other people + + align:start position:0% +the nice thing about the other people + + + align:start position:0% +the nice thing about the other people +found the solution is that you can just + + align:start position:0% +found the solution is that you can just + + + align:start position:0% +found the solution is that you can just +check it okay so so so you can check + + align:start position:0% +check it okay so so so you can check + + + align:start position:0% +check it okay so so so you can check +this quantity + + align:start position:0% + + + + align:start position:0% + +this solves the equation + + align:start position:0% +this solves the equation + + + align:start position:0% +this solves the equation +okay + + align:start position:0% + + + + align:start position:0% + +okay so so so just you can + + align:start position:0% +okay so so so just you can + + + align:start position:0% +okay so so so just you can +plug this + + align:start position:0% +plug this + + + align:start position:0% +plug this +so this is a commutative gamma Lambda + + align:start position:0% +so this is a commutative gamma Lambda + + + align:start position:0% +so this is a commutative gamma Lambda +and Gamma rho you plug into that then + + align:start position:0% +and Gamma rho you plug into that then + + + align:start position:0% +and Gamma rho you plug into that then +you just evaluate + + align:start position:0% +you just evaluate + + + align:start position:0% +you just evaluate +this gamma matrices okay + + align:start position:0% +this gamma matrices okay + + + align:start position:0% +this gamma matrices okay +and you uh use the um + + align:start position:0% +and you uh use the um + + + align:start position:0% +and you uh use the um +use this kind of equation over and over + + align:start position:0% +use this kind of equation over and over + + + align:start position:0% +use this kind of equation over and over +and you will find uh this is satisfied + + align:start position:0% +and you will find uh this is satisfied + + + align:start position:0% +and you will find uh this is satisfied +again I will leave it as exercise for + + align:start position:0% +again I will leave it as exercise for + + + align:start position:0% +again I will leave it as exercise for +yourself okay + + align:start position:0% + + + + align:start position:0% + +okay I exercise for yourself + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +that's how you get this + + align:start position:0% +that's how you get this + + + align:start position:0% +that's how you get this +yeah yeah then the last thing is now + + align:start position:0% +yeah yeah then the last thing is now + + + align:start position:0% +yeah yeah then the last thing is now +actually is uh damage transformed + + align:start position:0% +actually is uh damage transformed + + + align:start position:0% +actually is uh damage transformed +and it's not partial details + + align:start position:0% +and it's not partial details + + + align:start position:0% +and it's not partial details +it seems like you're linking a + + align:start position:0% +it seems like you're linking a + + + align:start position:0% +it seems like you're linking a +transformation and partial view of the + + align:start position:0% +transformation and partial view of the + + + align:start position:0% +transformation and partial view of the +transformation + + align:start position:0% + + + + align:start position:0% + +so so here we we want to match one and + + align:start position:0% +so so here we we want to match one and + + + align:start position:0% +so so here we we want to match one and +two okay + + align:start position:0% +two okay + + + align:start position:0% +two okay +so so the step is we do or how each + + align:start position:0% +so so the step is we do or how each + + + align:start position:0% +so so the step is we do or how each +equation for from equation one + + align:start position:0% +equation for from equation one + + + align:start position:0% +equation for from equation one +we reach here + + align:start position:0% + + + + align:start position:0% + +for me equation two + + align:start position:0% +for me equation two + + + align:start position:0% +for me equation two +we just plug this into there + + align:start position:0% +we just plug this into there + + + align:start position:0% +we just plug this into there +okay and so so each equation have done + + align:start position:0% +okay and so so each equation have done + + + align:start position:0% +okay and so so each equation have done +one step and then I equate them + + align:start position:0% + + + + align:start position:0% + +uh blend dangers and then in equation + + align:start position:0% +uh blend dangers and then in equation + + + align:start position:0% +uh blend dangers and then in equation +two you are transforming your gamma no + + align:start position:0% +two you are transforming your gamma no + + + align:start position:0% +two you are transforming your gamma no +no no no right no no no + + align:start position:0% +no no no right no no no + + + align:start position:0% +no no no right no no no +you want to show this you want to match + + align:start position:0% +you want to show this you want to match + + + align:start position:0% +you want to show this you want to match +this equation + + align:start position:0% +this equation + + + align:start position:0% +this equation +with this equation okay this equation is + + align:start position:0% +with this equation okay this equation is + + + align:start position:0% +with this equation okay this equation is +derived from one + + align:start position:0% +derived from one + + + align:start position:0% +derived from one +so we want to derive we want to find the + + align:start position:0% +so we want to derive we want to find the + + + align:start position:0% +so we want to derive we want to find the +two from one + + align:start position:0% +two from one + + + align:start position:0% +two from one +okay this equation one so I just + + align:start position:0% +okay this equation one so I just + + + align:start position:0% +okay this equation one so I just +slightly rewrite the equation two but by + + align:start position:0% +slightly rewrite the equation two but by + + + align:start position:0% +slightly rewrite the equation two but by +inserting this transformation here + + align:start position:0% +inserting this transformation here + + + align:start position:0% +inserting this transformation here +okay then I matched it + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% + + + + align:start position:0% + +okay good so now + + align:start position:0% + + + + align:start position:0% + +so now we can just uh + + align:start position:0% +so now we can just uh + + + align:start position:0% +so now we can just uh +um + + align:start position:0% +um + + + align:start position:0% +um +now we can just immediately so given + + align:start position:0% +now we can just immediately so given + + + align:start position:0% +now we can just immediately so given +this equation + + align:start position:0% + + + + align:start position:0% + +and now we can immediately written the + + align:start position:0% +and now we can immediately written the + + + align:start position:0% +and now we can immediately written the +final transformation okay + + align:start position:0% +final transformation okay + + + align:start position:0% +final transformation okay +so we saw finite transformation + + align:start position:0% + + + + align:start position:0% + +so so for each + + align:start position:0% + + + + align:start position:0% + +new + + align:start position:0% +new + + + align:start position:0% +new +each finite + + align:start position:0% + + + + align:start position:0% + +okay you can obtain the corresponding + + align:start position:0% +okay you can obtain the corresponding + + + align:start position:0% +okay you can obtain the corresponding +Omega mule + + align:start position:0% +Omega mule + + + align:start position:0% +Omega mule +okay and then this is also finite + + align:start position:0% + + + + align:start position:0% + +and now we can just obtain + + align:start position:0% +and now we can just obtain + + + align:start position:0% +and now we can just obtain +the S by exponentiate this okay and then + + align:start position:0% +the S by exponentiate this okay and then + + + align:start position:0% +the S by exponentiate this okay and then +then the corresponding s would be S + + align:start position:0% +then the corresponding s would be S + + + align:start position:0% +then the corresponding s would be S +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +spatial + + align:start position:0% +spatial + + + align:start position:0% +spatial +minus I over Q + + align:start position:0% +minus I over Q + + + align:start position:0% +minus I over Q +or Omega + + align:start position:0% + + + + align:start position:0% + +okay and the signal maybe we just came + + align:start position:0% +okay and the signal maybe we just came + + + align:start position:0% +okay and the signal maybe we just came +back this one okay + + align:start position:0% +back this one okay + + + align:start position:0% +back this one okay +so and you can check yourself this + + align:start position:0% +so and you can check yourself this + + + align:start position:0% +so and you can check yourself this +satisfies + + align:start position:0% +satisfies + + + align:start position:0% +satisfies +you can check + + align:start position:0% + + + + align:start position:0% + +this satisfies + + align:start position:0% +this satisfies + + + align:start position:0% +this satisfies +equations + + align:start position:0% + + + + align:start position:0% + +that finite equation + + align:start position:0% + + + + align:start position:0% + +good any questions on this + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% + + + + align:start position:0% + +so so now let me uh + + align:start position:0% + + + + align:start position:0% + +okay so now let's make some remarks + + align:start position:0% + + + + align:start position:0% + +so so then this asks + + align:start position:0% + + + + align:start position:0% + +it just generates + + align:start position:0% + + + + align:start position:0% + +a range transformation + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +because the only act on this uh off and + + align:start position:0% +because the only act on this uh off and + + + align:start position:0% +because the only act on this uh off and +beta okay + + align:start position:0% + + + + align:start position:0% + +so Sigma and J + + align:start position:0% +so Sigma and J + + + align:start position:0% +so Sigma and J +or Sigma Sigma mu according to our + + align:start position:0% +or Sigma Sigma mu according to our + + + align:start position:0% +or Sigma Sigma mu according to our +standards + + align:start position:0% +standards + + + align:start position:0% +standards +uh terminology this is called the + + align:start position:0% +uh terminology this is called the + + + align:start position:0% +uh terminology this is called the +generator + + align:start position:0% + + + + align:start position:0% + +of the transformation Okay so + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +when when + + align:start position:0% +when when + + + align:start position:0% +when when +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +you knew when the new new you go to + + align:start position:0% +you knew when the new new you go to + + + align:start position:0% +you knew when the new new you go to +spatial directions + + align:start position:0% +spatial directions + + + align:start position:0% +spatial directions +and then that's corresponding to a + + align:start position:0% +and then that's corresponding to a + + + align:start position:0% +and then that's corresponding to a +space-time space spatial rotation okay + + align:start position:0% +space-time space spatial rotation okay + + + align:start position:0% +space-time space spatial rotation okay +and the zero I corresponding to a boost + + align:start position:0% +and the zero I corresponding to a boost + + + align:start position:0% +and the zero I corresponding to a boost +okay so remember so so that means + + align:start position:0% +okay so remember so so that means + + + align:start position:0% +okay so remember so so that means +for for Sigma AJ + + align:start position:0% + + + + align:start position:0% + +to I equal to 4 + + align:start position:0% + + + + align:start position:0% + +comma a comma J + + align:start position:0% +comma a comma J + + + align:start position:0% +comma a comma J +this generates + + align:start position:0% + + + + align:start position:0% + +generators + + align:start position:0% + + + + align:start position:0% + +of rotations + + align:start position:0% + + + + align:start position:0% + +so also remember previously + + align:start position:0% +so also remember previously + + + align:start position:0% +so also remember previously +so if you remember how we do the long + + align:start position:0% +so if you remember how we do the long + + + align:start position:0% +so if you remember how we do the long +brain transformation + + align:start position:0% +brain transformation + + + align:start position:0% +brain transformation +the Omega i j + + align:start position:0% +the Omega i j + + + align:start position:0% +the Omega i j +would corresponding to the rotational + + align:start position:0% +would corresponding to the rotational + + + align:start position:0% +would corresponding to the rotational +angle + + align:start position:0% +angle + + + align:start position:0% +angle +in the IJ plane + + align:start position:0% +in the IJ plane + + + align:start position:0% +in the IJ plane +okay so you just rotate in the AJ plane + + align:start position:0% +okay so you just rotate in the AJ plane + + + align:start position:0% +okay so you just rotate in the AJ plane +by angle or or or yeah or + + align:start position:0% +by angle or or or yeah or + + + align:start position:0% +by angle or or or yeah or +Omega i j so then this then this just + + align:start position:0% +Omega i j so then this then this just + + + align:start position:0% +Omega i j so then this then this just +corresponding now because one into the + + align:start position:0% +corresponding now because one into the + + + align:start position:0% +corresponding now because one into the +generator of the rotations okay + + align:start position:0% +generator of the rotations okay + + + align:start position:0% +generator of the rotations okay +in IJ plane + + align:start position:0% + + + + align:start position:0% + +so you can because the gamma I and Gamma + + align:start position:0% +so you can because the gamma I and Gamma + + + align:start position:0% +so you can because the gamma I and Gamma +J are Commission + + align:start position:0% + + + + align:start position:0% + +we call that the gamma I + + align:start position:0% +we call that the gamma I + + + align:start position:0% +we call that the gamma I +distribution and then the + + align:start position:0% +distribution and then the + + + align:start position:0% +distribution and then the +Sigma i j + + align:start position:0% +Sigma i j + + + align:start position:0% +Sigma i j +is also Commission + + align:start position:0% +is also Commission + + + align:start position:0% +is also Commission +okay because when you take the take the + + align:start position:0% +okay because when you take the take the + + + align:start position:0% +okay because when you take the take the +diagram of this I give you a minus sign + + align:start position:0% +diagram of this I give you a minus sign + + + align:start position:0% +diagram of this I give you a minus sign +but the commutator give you a minus sign + + align:start position:0% +but the commutator give you a minus sign + + + align:start position:0% +but the commutator give you a minus sign +okay + + align:start position:0% +okay + + + align:start position:0% +okay +the coming to the Q minus so this is + + align:start position:0% +the coming to the Q minus so this is + + + align:start position:0% +the coming to the Q minus so this is +Commission so that means that the s + + align:start position:0% +Commission so that means that the s + + + align:start position:0% +Commission so that means that the s +which corresponding to a rotation + + align:start position:0% + + + + align:start position:0% + +is unitary okay so this is unitary + + align:start position:0% +is unitary okay so this is unitary + + + align:start position:0% +is unitary okay so this is unitary +so this is a unitary Matrix okay + + align:start position:0% + + + + align:start position:0% + +so now let's consider the sigma 0i + + align:start position:0% + + + + align:start position:0% + +which corresponding to the generator for + + align:start position:0% +which corresponding to the generator for + + + align:start position:0% +which corresponding to the generator for +Boost + + align:start position:0% + + + + align:start position:0% + +so this will have the form comma zero + + align:start position:0% +so this will have the form comma zero + + + align:start position:0% +so this will have the form comma zero +comma I + + align:start position:0% +comma I + + + align:start position:0% +comma I +so this is the generators for Boost + + align:start position:0% + + + + align:start position:0% + +in ice Direction + + align:start position:0% + + + + align:start position:0% + +okay in the in the in the spindle space + + align:start position:0% +okay in the in the in the spindle space + + + align:start position:0% +okay in the in the in the spindle space +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and now because the remember gamma zero + + align:start position:0% +and now because the remember gamma zero + + + align:start position:0% +and now because the remember gamma zero +when you take the dagger you get the + + align:start position:0% +when you take the dagger you get the + + + align:start position:0% +when you take the dagger you get the +minus sign + + align:start position:0% +minus sign + + + align:start position:0% +minus sign +so so the sigma zero I now if you take + + align:start position:0% +so so the sigma zero I now if you take + + + align:start position:0% +so so the sigma zero I now if you take +the dagger + + align:start position:0% +the dagger + + + align:start position:0% +the dagger +you actually also get the minus sign + + align:start position:0% +you actually also get the minus sign + + + align:start position:0% +you actually also get the minus sign +because the um yeah so now it's an + + align:start position:0% +because the um yeah so now it's an + + + align:start position:0% +because the um yeah so now it's an +anti-commission + + align:start position:0% +anti-commission + + + align:start position:0% +anti-commission +okay + + align:start position:0% + + + + align:start position:0% + +so that means + + align:start position:0% + + + + align:start position:0% + +so that means the post matrices okay so + + align:start position:0% +so that means the post matrices okay so + + + align:start position:0% +so that means the post matrices okay so +so this is a boost transformation + + align:start position:0% + + + + align:start position:0% + +so this is another unit region this is + + align:start position:0% +so this is another unit region this is + + + align:start position:0% +so this is another unit region this is +not unitary + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay so this is another unitary + + align:start position:0% +okay so this is another unitary + + + align:start position:0% +okay so this is another unitary +so so in general so normally as we said + + align:start position:0% +so so in general so normally as we said + + + align:start position:0% +so so in general so normally as we said +before normally when you do a symmetry + + align:start position:0% +before normally when you do a symmetry + + + align:start position:0% +before normally when you do a symmetry +transformation uh the transformation is + + align:start position:0% +transformation uh the transformation is + + + align:start position:0% +transformation uh the transformation is +unitary transformation but in this case + + align:start position:0% +unitary transformation but in this case + + + align:start position:0% +unitary transformation but in this case +actually uh yeah this is a classical + + align:start position:0% +actually uh yeah this is a classical + + + align:start position:0% +actually uh yeah this is a classical +transformation okay + + align:start position:0% +transformation okay + + + align:start position:0% +transformation okay +here uh it's actually another unitary + + align:start position:0% +here uh it's actually another unitary + + + align:start position:0% +here uh it's actually another unitary +Matrix okay + + align:start position:0% + + + + align:start position:0% + +okay so this implies + + align:start position:0% + + + + align:start position:0% + +so this implies + + align:start position:0% + + + + align:start position:0% + +that a stagger in general + + align:start position:0% +that a stagger in general + + + align:start position:0% +that a stagger in general +for General Lauren transformation + + align:start position:0% + + + + align:start position:0% + +say which including both say a rotation + + align:start position:0% +say which including both say a rotation + + + align:start position:0% +say which including both say a rotation +boost + + align:start position:0% + + + + align:start position:0% + +so S and S cycle is not equal to one + + align:start position:0% +so S and S cycle is not equal to one + + + align:start position:0% +so S and S cycle is not equal to one +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yes it's not u21 + + align:start position:0% +yes it's not u21 + + + align:start position:0% +yes it's not u21 +so this has very important consequences + + align:start position:0% +so this has very important consequences + + + align:start position:0% +so this has very important consequences +for for example for writing down an + + align:start position:0% +for for example for writing down an + + + align:start position:0% +for for example for writing down an +action for the rock equation + + align:start position:0% +action for the rock equation + + + align:start position:0% +action for the rock equation +so so far we only uh uh are writing + + align:start position:0% +so so far we only uh uh are writing + + + align:start position:0% +so so far we only uh uh are writing +wrote down the rock equation + + align:start position:0% +wrote down the rock equation + + + align:start position:0% +wrote down the rock equation +but we did remember previously we know + + align:start position:0% +but we did remember previously we know + + + align:start position:0% +but we did remember previously we know +we normally start with the action first + + align:start position:0% +we normally start with the action first + + + align:start position:0% +we normally start with the action first +and then from the action we derive + + align:start position:0% +and then from the action we derive + + + align:start position:0% +and then from the action we derive +equation motion but in this case + + align:start position:0% + + + + align:start position:0% + +um yeah since this spinder is a + + align:start position:0% +um yeah since this spinder is a + + + align:start position:0% +um yeah since this spinder is a +completely new concept we started with + + align:start position:0% +completely new concept we started with + + + align:start position:0% +completely new concept we started with +actually the equation okay but now if we + + align:start position:0% +actually the equation okay but now if we + + + align:start position:0% +actually the equation okay but now if we +want to write down our action + + align:start position:0% +want to write down our action + + + align:start position:0% +want to write down our action +which is by definition should be low + + align:start position:0% +which is by definition should be low + + + align:start position:0% +which is by definition should be low +renting warrant then we should + + align:start position:0% +renting warrant then we should + + + align:start position:0% +renting warrant then we should +construct quantities which are involved + + align:start position:0% +construct quantities which are involved + + + align:start position:0% +construct quantities which are involved +with non-lawrence Transformations okay + + align:start position:0% +with non-lawrence Transformations okay + + + align:start position:0% +with non-lawrence Transformations okay +and so and so this uh uh this poverty + + align:start position:0% +and so and so this uh uh this poverty + + + align:start position:0% +and so and so this uh uh this poverty +then become a key okay yes + + align:start position:0% + + + + align:start position:0% + +no no here we are not talking about + + align:start position:0% +no no here we are not talking about + + + align:start position:0% +no no here we are not talking about +quantum mechanics here we're just + + align:start position:0% +quantum mechanics here we're just + + + align:start position:0% +quantum mechanics here we're just +talking about the equations classical + + align:start position:0% +talking about the equations classical + + + align:start position:0% +talking about the equations classical +equations we are just talking about + + align:start position:0% +equations we are just talking about + + + align:start position:0% +equations we are just talking about +their Matrix they're just Matrix + + align:start position:0% +their Matrix they're just Matrix + + + align:start position:0% +their Matrix they're just Matrix +we are talking about the uh whether they + + align:start position:0% +we are talking about the uh whether they + + + align:start position:0% +we are talking about the uh whether they +are unitary Matrix or their uh uh uh are + + align:start position:0% +are unitary Matrix or their uh uh uh are + + + align:start position:0% +are unitary Matrix or their uh uh uh are +not unitary Matrix they're just ordinary + + align:start position:0% +not unitary Matrix they're just ordinary + + + align:start position:0% +not unitary Matrix they're just ordinary +matrices four by four matrices + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% + + + + align:start position:0% + +so that means + + align:start position:0% + + + + align:start position:0% + +said dagger + + align:start position:0% + + + + align:start position:0% + +PSI + + align:start position:0% +PSI + + + align:start position:0% +PSI +Okay so + + align:start position:0% +Okay so + + + align:start position:0% +Okay so +is a row vector and this is the column + + align:start position:0% +is a row vector and this is the column + + + align:start position:0% +is a row vector and this is the column +vector and all together this is a number + + align:start position:0% +vector and all together this is a number + + + align:start position:0% +vector and all together this is a number +so this means this is not a scalar + + align:start position:0% + + + + align:start position:0% + +so so this transform under low range + + align:start position:0% +so so this transform under low range + + + align:start position:0% +so so this transform under low range +transformation as + + align:start position:0% +transformation as + + + align:start position:0% +transformation as +stagger + + align:start position:0% +stagger + + + align:start position:0% +stagger +s PSI + + align:start position:0% +s PSI + + + align:start position:0% +s PSI +so that means this is not since this is + + align:start position:0% +so that means this is not since this is + + + align:start position:0% +so that means this is not since this is +not equal to one then this is not + + align:start position:0% +not equal to one then this is not + + + align:start position:0% +not equal to one then this is not +scalar + + align:start position:0% + + + + align:start position:0% + +and the low range transformation okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so uh so now we have to search a + + align:start position:0% +so so uh so now we have to search a + + + align:start position:0% +so so uh so now we have to search a +little bit harder + + align:start position:0% +little bit harder + + + align:start position:0% +little bit harder +to to uh + + align:start position:0% +to to uh + + + align:start position:0% +to to uh +um + + align:start position:0% +um + + + align:start position:0% +um +uh to find the scalar okay so yeah in + + align:start position:0% +uh to find the scalar okay so yeah in + + + align:start position:0% +uh to find the scalar okay so yeah in +order to write the action we need to + + align:start position:0% +order to write the action we need to + + + align:start position:0% +order to write the action we need to +find something which is environment + + align:start position:0% +find something which is environment + + + align:start position:0% +find something which is environment +transformation + + align:start position:0% + + + + align:start position:0% + +so the the easy thing to think about is + + align:start position:0% +so the the easy thing to think about is + + + align:start position:0% +so the the easy thing to think about is +this quantity okay because this + + align:start position:0% +this quantity okay because this + + + align:start position:0% +this quantity okay because this +automatically give you a number okay + + align:start position:0% +automatically give you a number okay + + + align:start position:0% +automatically give you a number okay +but this thing won't work okay so we + + align:start position:0% +but this thing won't work okay so we + + + align:start position:0% +but this thing won't work okay so we +have to search a little bit harder okay + + align:start position:0% +have to search a little bit harder okay + + + align:start position:0% +have to search a little bit harder okay +so to do that let's um we can get some + + align:start position:0% +so to do that let's um we can get some + + + align:start position:0% +so to do that let's um we can get some +hint + + align:start position:0% +hint + + + align:start position:0% +hint +from the following identity + + align:start position:0% +from the following identity + + + align:start position:0% +from the following identity +okay so let's look at what this s tag is + + align:start position:0% +okay so let's look at what this s tag is + + + align:start position:0% +okay so let's look at what this s tag is +really is okay + + align:start position:0% +really is okay + + + align:start position:0% +really is okay +so let's look at the property of s tag + + align:start position:0% +so let's look at the property of s tag + + + align:start position:0% +so let's look at the property of s tag +so so + + align:start position:0% +so so + + + align:start position:0% +so so +um + + align:start position:0% + + + + align:start position:0% + +so recall that the uh I think I erased + + align:start position:0% +so recall that the uh I think I erased + + + align:start position:0% +so recall that the uh I think I erased +it + + align:start position:0% +it + + + align:start position:0% +it +yeah so so let me just write it again so + + align:start position:0% +yeah so so let me just write it again so + + + align:start position:0% +yeah so so let me just write it again so +gamma mu dagger + + align:start position:0% +gamma mu dagger + + + align:start position:0% +gamma mu dagger +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +gamma zero + + align:start position:0% +gamma zero + + + align:start position:0% +gamma zero +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +comma zero okay so now let's try to find + + align:start position:0% +comma zero okay so now let's try to find + + + align:start position:0% +comma zero okay so now let's try to find +what's mu mu dagger + + align:start position:0% +what's mu mu dagger + + + align:start position:0% +what's mu mu dagger +so let's write music in the uniform so + + align:start position:0% +so let's write music in the uniform so + + + align:start position:0% +so let's write music in the uniform so +so even though we wrote it separately + + align:start position:0% +so even though we wrote it separately + + + align:start position:0% +so even though we wrote it separately +so you can easily check yourself because + + align:start position:0% +so you can easily check yourself because + + + align:start position:0% +so you can easily check yourself because +of this property + + align:start position:0% +of this property + + + align:start position:0% +of this property +so this is just given by minus gamma + + align:start position:0% +so this is just given by minus gamma + + + align:start position:0% +so this is just given by minus gamma +zero + + align:start position:0% +zero + + + align:start position:0% +zero +Sigma mu + + align:start position:0% +Sigma mu + + + align:start position:0% +Sigma mu +comma zero okay + + align:start position:0% + + + + align:start position:0% + +because this is just a commutator so you + + align:start position:0% +because this is just a commutator so you + + + align:start position:0% +because this is just a commutator so you +can easily work it out that you just get + + align:start position:0% +can easily work it out that you just get + + + align:start position:0% +can easily work it out that you just get +this okay + + align:start position:0% + + + + align:start position:0% + +so now we can find the what uh what a + + align:start position:0% +so now we can find the what uh what a + + + align:start position:0% +so now we can find the what uh what a +stagger + + align:start position:0% + + + + align:start position:0% + +so a stagger + + align:start position:0% +so a stagger + + + align:start position:0% +so a stagger +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +the exponential one half I + + align:start position:0% +the exponential one half I + + + align:start position:0% +the exponential one half I +Omega mu mu + + align:start position:0% +Omega mu mu + + + align:start position:0% +Omega mu mu +then Sigma mu diagram + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and then this is equal to + + align:start position:0% + + + + align:start position:0% + +I over 2 Omega mu + + align:start position:0% +I over 2 Omega mu + + + align:start position:0% +I over 2 Omega mu +minus + + align:start position:0% +minus + + + align:start position:0% +minus +comma zero + + align:start position:0% +comma zero + + + align:start position:0% +comma zero +Sigma mu comma zero + + align:start position:0% +Sigma mu comma zero + + + align:start position:0% +Sigma mu comma zero +okay + + align:start position:0% + + + + align:start position:0% + +so now if you remember gamma zero square + + align:start position:0% +so now if you remember gamma zero square + + + align:start position:0% +so now if you remember gamma zero square +is equal to minus one + + align:start position:0% +is equal to minus one + + + align:start position:0% +is equal to minus one +so whenever you have a such a situation + + align:start position:0% +so whenever you have a such a situation + + + align:start position:0% +so whenever you have a such a situation +and the uh and because gamma zero square + + align:start position:0% +and the uh and because gamma zero square + + + align:start position:0% +and the uh and because gamma zero square +is equal to -1 + + align:start position:0% +is equal to -1 + + + align:start position:0% +is equal to -1 +then you can actually take the gamma + + align:start position:0% +then you can actually take the gamma + + + align:start position:0% +then you can actually take the gamma +zero outside of the exponential + + align:start position:0% +zero outside of the exponential + + + align:start position:0% +zero outside of the exponential +so this is actually equal to + + align:start position:0% +so this is actually equal to + + + align:start position:0% +so this is actually equal to +minus gamma zero + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +comma zero foreign + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so if you just think you do a Taylor + + align:start position:0% +so so if you just think you do a Taylor + + + align:start position:0% +so so if you just think you do a Taylor +expansion of this expansion + + align:start position:0% +expansion of this expansion + + + align:start position:0% +expansion of this expansion +and then then when you take the uh + + align:start position:0% +and then then when you take the uh + + + align:start position:0% +and then then when you take the uh +the power of this + + align:start position:0% +the power of this + + + align:start position:0% +the power of this +then for each term the gamma zero at the + + align:start position:0% +then for each term the gamma zero at the + + + align:start position:0% +then for each term the gamma zero at the +end will + + align:start position:0% +end will + + + align:start position:0% +end will +pair with the gamma zero at the big + + align:start position:0% +pair with the gamma zero at the big + + + align:start position:0% +pair with the gamma zero at the big +beginning of the other term and then + + align:start position:0% +beginning of the other term and then + + + align:start position:0% +beginning of the other term and then +they give you minus one + + align:start position:0% +they give you minus one + + + align:start position:0% +they give you minus one +okay and then you have only the first + + align:start position:0% +okay and then you have only the first + + + align:start position:0% +okay and then you have only the first +gamma zero and the mass comma zero left + + align:start position:0% +gamma zero and the mass comma zero left + + + align:start position:0% +gamma zero and the mass comma zero left +and because that's given minus one they + + align:start position:0% +and because that's given minus one they + + + align:start position:0% +and because that's given minus one they +change this minus sign to a plus sign + + align:start position:0% +change this minus sign to a plus sign + + + align:start position:0% +change this minus sign to a plus sign +okay so you just do a Taylor expansion + + align:start position:0% +okay so you just do a Taylor expansion + + + align:start position:0% +okay so you just do a Taylor expansion +you will find here okay + + align:start position:0% +you will find here okay + + + align:start position:0% +you will find here okay +still explaining fine here + + align:start position:0% +still explaining fine here + + + align:start position:0% +still explaining fine here +and now we find the license relation + + align:start position:0% +and now we find the license relation + + + align:start position:0% +and now we find the license relation +so we find that this is just malice + + align:start position:0% +so we find that this is just malice + + + align:start position:0% +so we find that this is just malice +gamma zero and this is just equal to S + + align:start position:0% +gamma zero and this is just equal to S + + + align:start position:0% +gamma zero and this is just equal to S +minus one + + align:start position:0% +minus one + + + align:start position:0% +minus one +as a gamma zero + + align:start position:0% +as a gamma zero + + + align:start position:0% +as a gamma zero +ok + + align:start position:0% +ok + + + align:start position:0% +ok +so we find that the S tag is actually + + align:start position:0% +so we find that the S tag is actually + + + align:start position:0% +so we find that the S tag is actually +minus gamma zero s minus one uh + + align:start position:0% +minus gamma zero s minus one uh + + + align:start position:0% +minus gamma zero s minus one uh +then this tells us + + align:start position:0% +then this tells us + + + align:start position:0% +then this tells us +okay for from this property + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +tells us that this quantity + + align:start position:0% + + + + align:start position:0% + +comma zero of PSI + + align:start position:0% + + + + align:start position:0% + +should transform as a scalar okay so now + + align:start position:0% +should transform as a scalar okay so now + + + align:start position:0% +should transform as a scalar okay so now +let's take a look so this + + align:start position:0% +let's take a look so this + + + align:start position:0% +let's take a look so this +so this when you uh do a transformation + + align:start position:0% +so this when you uh do a transformation + + + align:start position:0% +so this when you uh do a transformation +so this gives you the side dagger + + align:start position:0% +so this gives you the side dagger + + + align:start position:0% +so this gives you the side dagger +a stagger + + align:start position:0% +a stagger + + + align:start position:0% +a stagger +and you have gamma zero + + align:start position:0% +and you have gamma zero + + + align:start position:0% +and you have gamma zero +then you have S PSI on the lower end + + align:start position:0% +then you have S PSI on the lower end + + + align:start position:0% +then you have S PSI on the lower end +transformation okay + + align:start position:0% +transformation okay + + + align:start position:0% +transformation okay +and now you're plugging this into a + + align:start position:0% +and now you're plugging this into a + + + align:start position:0% +and now you're plugging this into a +plugging a stack or equal to this into + + align:start position:0% +plugging a stack or equal to this into + + + align:start position:0% +plugging a stack or equal to this into +here + + align:start position:0% +here + + + align:start position:0% +here +yeah you just get + + align:start position:0% + + + + align:start position:0% + +minus dagger + + align:start position:0% + + + + align:start position:0% + +so this is comma zero and stack s minus + + align:start position:0% +so this is comma zero and stack s minus + + + align:start position:0% +so this is comma zero and stack s minus +one comma zero + + align:start position:0% +one comma zero + + + align:start position:0% +one comma zero +then gamma zero as PSI okay so this + + align:start position:0% +then gamma zero as PSI okay so this + + + align:start position:0% +then gamma zero as PSI okay so this +give you minus one cancel which is the + + align:start position:0% +give you minus one cancel which is the + + + align:start position:0% +give you minus one cancel which is the +one here and then S1 cancel with as s + + align:start position:0% +one here and then S1 cancel with as s + + + align:start position:0% +one here and then S1 cancel with as s +minus one cancels with s and then you + + align:start position:0% +minus one cancels with s and then you + + + align:start position:0% +minus one cancels with s and then you +have + + align:start position:0% + + + + align:start position:0% + +okay so this actually it's low renting + + align:start position:0% +okay so this actually it's low renting + + + align:start position:0% +okay so this actually it's low renting +warrant + + align:start position:0% +warrant + + + align:start position:0% +warrant +okay so this is laurentium art + + align:start position:0% + + + + align:start position:0% + +so now we find a nice low range + + align:start position:0% +so now we find a nice low range + + + align:start position:0% +so now we find a nice low range +environment quantity okay + + align:start position:0% +environment quantity okay + + + align:start position:0% +environment quantity okay +so since we use this all the time + + align:start position:0% +so since we use this all the time + + + align:start position:0% +so since we use this all the time +since we use this all the time so it's + + align:start position:0% +since we use this all the time so it's + + + align:start position:0% +since we use this all the time so it's +convenient to introduce a new notation + + align:start position:0% + + + + align:start position:0% + +so so now you introduce + + align:start position:0% +so so now you introduce + + + align:start position:0% +so so now you introduce +a minute + + align:start position:0% + + + + align:start position:0% + +we call PSI bar + + align:start position:0% +we call PSI bar + + + align:start position:0% +we call PSI bar +you're going to say that + + align:start position:0% +you're going to say that + + + align:start position:0% +you're going to say that +go to side dagger + + align:start position:0% +go to side dagger + + + align:start position:0% +go to side dagger +so here it's all just crossed this is + + align:start position:0% +so here it's all just crossed this is + + + align:start position:0% +so here it's all just crossed this is +stagger and it's all just matrix + + align:start position:0% +stagger and it's all just matrix + + + align:start position:0% +stagger and it's all just matrix +multiplication okay + + align:start position:0% +multiplication okay + + + align:start position:0% +multiplication okay +right now we are considering a classical + + align:start position:0% +right now we are considering a classical + + + align:start position:0% +right now we are considering a classical +Theory + + align:start position:0% +Theory + + + align:start position:0% +Theory +and so so it's convenient to introduce + + align:start position:0% +and so so it's convenient to introduce + + + align:start position:0% +and so so it's convenient to introduce +objects like this okay + + align:start position:0% +objects like this okay + + + align:start position:0% +objects like this okay +and then then we know that then PSI bar + + align:start position:0% +and then then we know that then PSI bar + + + align:start position:0% +and then then we know that then PSI bar +PSI is a scalar + + align:start position:0% +PSI is a scalar + + + align:start position:0% +PSI is a scalar +okay so so that thing just becomes a bar + + align:start position:0% +okay so so that thing just becomes a bar + + + align:start position:0% +okay so so that thing just becomes a bar +inside okay + + align:start position:0% + + + + align:start position:0% + +so so it's convenient to work out + + align:start position:0% +so so it's convenient to work out + + + align:start position:0% +so so it's convenient to work out +the the help type bar transformed by + + align:start position:0% +the the help type bar transformed by + + + align:start position:0% +the the help type bar transformed by +itself + + align:start position:0% +itself + + + align:start position:0% +itself +okay so so you just use this relation so + + align:start position:0% +okay so so you just use this relation so + + + align:start position:0% +okay so so you just use this relation so +you can check yourself okay so so + + align:start position:0% +you can check yourself okay so so + + + align:start position:0% +you can check yourself okay so so +exercise for you to check yourself + + align:start position:0% +exercise for you to check yourself + + + align:start position:0% +exercise for you to check yourself +under low range transformation we say + + align:start position:0% +under low range transformation we say + + + align:start position:0% +under low range transformation we say +bar + + align:start position:0% +bar + + + align:start position:0% +bar +X + + align:start position:0% +X + + + align:start position:0% +X +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +PSI bar Prime X Prime + + align:start position:0% +PSI bar Prime X Prime + + + align:start position:0% +PSI bar Prime X Prime +okay so if you go to the new episode bar + + align:start position:0% +okay so if you go to the new episode bar + + + align:start position:0% +okay so if you go to the new episode bar +Prime X Prime is equal to psi + + align:start position:0% +Prime X Prime is equal to psi + + + align:start position:0% +Prime X Prime is equal to psi +Phi X + + align:start position:0% +Phi X + + + align:start position:0% +Phi X +s minus one okay + + align:start position:0% +s minus one okay + + + align:start position:0% +s minus one okay +so you can easily check yourself this + + align:start position:0% +so you can easily check yourself this + + + align:start position:0% +so you can easily check yourself this +relation okay + + align:start position:0% + + + + align:start position:0% + +similarly using the using this + + align:start position:0% +similarly using the using this + + + align:start position:0% +similarly using the using this +transformation of gamma a partial mu you + + align:start position:0% +transformation of gamma a partial mu you + + + align:start position:0% +transformation of gamma a partial mu you +can also trans check + + align:start position:0% +can also trans check + + + align:start position:0% +can also trans check +that the gamma mu + + align:start position:0% +that the gamma mu + + + align:start position:0% +that the gamma mu +passion knew + + align:start position:0% + + + + align:start position:0% + +so Prime PSI Prime X + + align:start position:0% +so Prime PSI Prime X + + + align:start position:0% +so Prime PSI Prime X +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +equal to s + + align:start position:0% +equal to s + + + align:start position:0% +equal to s +gamma mu partial mu PSI + + align:start position:0% +gamma mu partial mu PSI + + + align:start position:0% +gamma mu partial mu PSI +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you can also check yourself or check + + align:start position:0% +so you can also check yourself or check + + + align:start position:0% +so you can also check yourself or check +this equation + + align:start position:0% + + + + align:start position:0% + +okay so yeah this is the just by using + + align:start position:0% +okay so yeah this is the just by using + + + align:start position:0% +okay so yeah this is the just by using +this properties of a stagger uh yeah + + align:start position:0% +this properties of a stagger uh yeah + + + align:start position:0% +this properties of a stagger uh yeah +just yeah this you don't use the you + + align:start position:0% +just yeah this you don't use the you + + + align:start position:0% +just yeah this you don't use the you +only use above the Stagger just use the + + align:start position:0% +only use above the Stagger just use the + + + align:start position:0% +only use above the Stagger just use the +how partial mu Prime transform and how + + align:start position:0% +how partial mu Prime transform and how + + + align:start position:0% +how partial mu Prime transform and how +PSI transform and then you can show this + + align:start position:0% +PSI transform and then you can show this + + + align:start position:0% +PSI transform and then you can show this +is true okay + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so so this also this gamma mu partial mu + + align:start position:0% +so so this also this gamma mu partial mu + + + align:start position:0% +so so this also this gamma mu partial mu +will appear a lot because this appears + + align:start position:0% +will appear a lot because this appears + + + align:start position:0% +will appear a lot because this appears +in the uh the rock equation so it's + + align:start position:0% +in the uh the rock equation so it's + + + align:start position:0% +in the uh the rock equation so it's +convenient to introduce a new rotation + + align:start position:0% +convenient to introduce a new rotation + + + align:start position:0% +convenient to introduce a new rotation +say + + align:start position:0% +say + + + align:start position:0% +say +comma mu partial mu + + align:start position:0% +comma mu partial mu + + + align:start position:0% +comma mu partial mu +we Define TB partial slash okay + + align:start position:0% +we Define TB partial slash okay + + + align:start position:0% +we Define TB partial slash okay +so so essentially + + align:start position:0% +so so essentially + + + align:start position:0% +so so essentially +anything + + align:start position:0% +anything + + + align:start position:0% +anything +slash corresponding to that thing + + align:start position:0% +slash corresponding to that thing + + + align:start position:0% +slash corresponding to that thing +contracts with gamma mu okay + + align:start position:0% + + + + align:start position:0% + +so and then this equation then can be + + align:start position:0% +so and then this equation then can be + + + align:start position:0% +so and then this equation then can be +written as + + align:start position:0% +written as + + + align:start position:0% +written as +the the partial + + align:start position:0% +the the partial + + + align:start position:0% +the the partial +Prime slash PSI Prime X Prime + + align:start position:0% +Prime slash PSI Prime X Prime + + + align:start position:0% +Prime slash PSI Prime X Prime +equal to s + + align:start position:0% +equal to s + + + align:start position:0% +equal to s +partial slash X + + align:start position:0% +partial slash X + + + align:start position:0% +partial slash X +okay + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +so so let me just mention one more since + + align:start position:0% +so so let me just mention one more since + + + align:start position:0% +so so let me just mention one more since +you can you can work out yourself okay + + align:start position:0% +you can you can work out yourself okay + + + align:start position:0% +you can you can work out yourself okay +so you can check + + align:start position:0% +so you can check + + + align:start position:0% +so you can check +so so so these are all things you can + + align:start position:0% +so so so these are all things you can + + + align:start position:0% +so so so these are all things you can +check yourself + + align:start position:0% +check yourself + + + align:start position:0% +check yourself +okay once you equip those + + align:start position:0% +okay once you equip those + + + align:start position:0% +okay once you equip those +transformations + + align:start position:0% +transformations + + + align:start position:0% +transformations +you can also check + + align:start position:0% +you can also check + + + align:start position:0% +you can also check +that come up + + align:start position:0% +that come up + + + align:start position:0% +that come up +sidebar + + align:start position:0% +sidebar + + + align:start position:0% +sidebar +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +PSI transforms as a vector + + align:start position:0% + + + + align:start position:0% + +okay that means + + align:start position:0% + + + + align:start position:0% + +that means + + align:start position:0% +that means + + + align:start position:0% +that means +PSI power Prime X Prime + + align:start position:0% +PSI power Prime X Prime + + + align:start position:0% +PSI power Prime X Prime +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +PSI Prime X Prime + + align:start position:0% +PSI Prime X Prime + + + align:start position:0% +PSI Prime X Prime +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +Lambda mu Nu + + align:start position:0% + + + + align:start position:0% + +PSI bar X plus I bar X + + align:start position:0% +PSI bar X plus I bar X + + + align:start position:0% +PSI bar X plus I bar X +comma Nu + + align:start position:0% +comma Nu + + + align:start position:0% +comma Nu +PSI X + + align:start position:0% +PSI X + + + align:start position:0% +PSI X +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you view this whole thing as a + + align:start position:0% +so if you view this whole thing as a + + + align:start position:0% +so if you view this whole thing as a +vector + + align:start position:0% +vector + + + align:start position:0% +vector +and then you see the prime the quantity + + align:start position:0% +and then you see the prime the quantity + + + align:start position:0% +and then you see the prime the quantity +is equal to just a + + align:start position:0% +is equal to just a + + + align:start position:0% +is equal to just a +the low rents transformation Lambda on + + align:start position:0% +the low rents transformation Lambda on + + + align:start position:0% +the low rents transformation Lambda on +itself okay + + align:start position:0% + + + + align:start position:0% + +so again this is something just based on + + align:start position:0% +so again this is something just based on + + + align:start position:0% +so again this is something just based on +the transformations of s and the + + align:start position:0% +the transformations of s and the + + + align:start position:0% +the transformations of s and the +relations between different comma + + align:start position:0% +relations between different comma + + + align:start position:0% +relations between different comma +matrices you can + + align:start position:0% +matrices you can + + + align:start position:0% +matrices you can +just show that + + align:start position:0% + + + + align:start position:0% + +good any questions on this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now with these preparations we can + + align:start position:0% +so now with these preparations we can + + + align:start position:0% +so now with these preparations we can +now write down the uh the action + + align:start position:0% +now write down the uh the action + + + align:start position:0% +now write down the uh the action +which give rise to the diracy equation + + align:start position:0% +which give rise to the diracy equation + + + align:start position:0% +which give rise to the diracy equation +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so the uh + + align:start position:0% +so so the uh + + + align:start position:0% +so so the uh +now we can write down the diracy + + align:start position:0% + + + + align:start position:0% + +and the action which gives you the + + align:start position:0% +and the action which gives you the + + + align:start position:0% +and the action which gives you the +question so I will just write down the + + align:start position:0% +question so I will just write down the + + + align:start position:0% +question so I will just write down the +answer it's very intuitive + + align:start position:0% +answer it's very intuitive + + + align:start position:0% +answer it's very intuitive +so you have just essentially s + + align:start position:0% +so you have just essentially s + + + align:start position:0% +so you have just essentially s +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +minus I + + align:start position:0% + + + + align:start position:0% + +d4x + + align:start position:0% +d4x + + + align:start position:0% +d4x +PSI bar + + align:start position:0% +PSI bar + + + align:start position:0% +PSI bar +gamma mu partial mu + + align:start position:0% +gamma mu partial mu + + + align:start position:0% +gamma mu partial mu +minus M PSI + + align:start position:0% +minus M PSI + + + align:start position:0% +minus M PSI +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is the answer + + align:start position:0% + + + + align:start position:0% + +so yeah so so the the worry seems to + + align:start position:0% +so yeah so so the the worry seems to + + + align:start position:0% +so yeah so so the the worry seems to +uncompact here + + align:start position:0% + + + + align:start position:0% + +so so first just based on those + + align:start position:0% +so so first just based on those + + + align:start position:0% +so so first just based on those +relations + + align:start position:0% +relations + + + align:start position:0% +relations +based on this is a scalar + + align:start position:0% +based on this is a scalar + + + align:start position:0% +based on this is a scalar +this is a scalar + + align:start position:0% +this is a scalar + + + align:start position:0% +this is a scalar +and the transformation of this + + align:start position:0% +and the transformation of this + + + align:start position:0% +and the transformation of this +okay you can immediately see that this + + align:start position:0% +okay you can immediately see that this + + + align:start position:0% +okay you can immediately see that this +is a Lorenz scalar okay because you only + + align:start position:0% +is a Lorenz scalar okay because you only + + + align:start position:0% +is a Lorenz scalar okay because you only +move two variable one quantities PSI bar + + align:start position:0% +move two variable one quantities PSI bar + + + align:start position:0% +move two variable one quantities PSI bar +PSI with this m term and then PSI bar + + align:start position:0% +PSI with this m term and then PSI bar + + + align:start position:0% +PSI with this m term and then PSI bar +gamma mu function mule size and and that + + align:start position:0% +gamma mu function mule size and and that + + + align:start position:0% +gamma mu function mule size and and that +we already show here that the transform + + align:start position:0% +we already show here that the transform + + + align:start position:0% +we already show here that the transform +SS yeah uh so yeah you can easily check + + align:start position:0% +SS yeah uh so yeah you can easily check + + + align:start position:0% +SS yeah uh so yeah you can easily check +just based on those equations that this + + align:start position:0% +just based on those equations that this + + + align:start position:0% +just based on those equations that this +is a scale okay and this is the orange + + align:start position:0% +is a scale okay and this is the orange + + + align:start position:0% +is a scale okay and this is the orange +environment + + align:start position:0% +environment + + + align:start position:0% +environment +uh so the second thing is that + + align:start position:0% +uh so the second thing is that + + + align:start position:0% +uh so the second thing is that +this I here + + align:start position:0% + + + + align:start position:0% + +is for to make the action is real + + align:start position:0% + + + + align:start position:0% + +because you can show if you take the + + align:start position:0% +because you can show if you take the + + + align:start position:0% +because you can show if you take the +complex conjugate of these you actually + + align:start position:0% +complex conjugate of these you actually + + + align:start position:0% +complex conjugate of these you actually +get the minus num a minus sign and so + + align:start position:0% +get the minus num a minus sign and so + + + align:start position:0% +get the minus num a minus sign and so +you need the I to make it real okay + + align:start position:0% +you need the I to make it real okay + + + align:start position:0% +you need the I to make it real okay +and this minus sign + + align:start position:0% +and this minus sign + + + align:start position:0% +and this minus sign +which cannot be explained now which we + + align:start position:0% +which cannot be explained now which we + + + align:start position:0% +which cannot be explained now which we +will talk about it later uh when we + + align:start position:0% +will talk about it later uh when we + + + align:start position:0% +will talk about it later uh when we +quantize the theory and we see actually + + align:start position:0% +quantize the theory and we see actually + + + align:start position:0% +quantize the theory and we see actually +we need to put the minus sign here uh + + align:start position:0% +we need to put the minus sign here uh + + + align:start position:0% +we need to put the minus sign here uh +yeah + + align:start position:0% + + + + align:start position:0% + +we are we are not really singling all + + align:start position:0% +we are we are not really singling all + + + align:start position:0% +we are we are not really singling all +the time direction we just + + align:start position:0% +the time direction we just + + + align:start position:0% +the time direction we just +just due to the property that gamma zero + + align:start position:0% +just due to the property that gamma zero + + + align:start position:0% +just due to the property that gamma zero +is not a hermitian + + align:start position:0% +is not a hermitian + + + align:start position:0% +is not a hermitian +yeah just so because if you look at all + + align:start position:0% +yeah just so because if you look at all + + + align:start position:0% +yeah just so because if you look at all +these all these complex complications + + align:start position:0% +these all these complex complications + + + align:start position:0% +these all these complex complications +just related to that this stagger is not + + align:start position:0% +just related to that this stagger is not + + + align:start position:0% +just related to that this stagger is not +yes it's not unitary and the reason is + + align:start position:0% +yes it's not unitary and the reason is + + + align:start position:0% +yes it's not unitary and the reason is +not utilities because gamma zero is not + + align:start position:0% +not utilities because gamma zero is not + + + align:start position:0% +not utilities because gamma zero is not +a commission yeah so you have to + + align:start position:0% +a commission yeah so you have to + + + align:start position:0% +a commission yeah so you have to +put in the gamma zero in various places + + align:start position:0% +put in the gamma zero in various places + + + align:start position:0% +put in the gamma zero in various places +to compensate for that + + align:start position:0% +to compensate for that + + + align:start position:0% +to compensate for that +yeah + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +other questions yes so I guess the + + align:start position:0% +other questions yes so I guess the + + + align:start position:0% +other questions yes so I guess the +action + + align:start position:0% +action + + + align:start position:0% +action +if uh lorenzenber Lawrence Taylor you + + align:start position:0% +if uh lorenzenber Lawrence Taylor you + + + align:start position:0% +if uh lorenzenber Lawrence Taylor you +could have constructed like some product + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +yeah so the sidebar gamma so that would + + align:start position:0% +yeah so the sidebar gamma so that would + + + align:start position:0% +yeah so the sidebar gamma so that would +be allowed + + align:start position:0% +be allowed + + + align:start position:0% +be allowed +I guess this gives the right answer but + + align:start position:0% +I guess this gives the right answer but + + + align:start position:0% +I guess this gives the right answer but +that could have appeared in the action + + align:start position:0% +that could have appeared in the action + + + align:start position:0% +that could have appeared in the action +which yeah disappeared in action yeah + + align:start position:0% +which yeah disappeared in action yeah + + + align:start position:0% +which yeah disappeared in action yeah +yeah so this is the so because this is a + + align:start position:0% +yeah so this is the so because this is a + + + align:start position:0% +yeah so this is the so because this is a +vector + + align:start position:0% +vector + + + align:start position:0% +vector +so when this contracts with partial mule + + align:start position:0% +so when this contracts with partial mule + + + align:start position:0% +so when this contracts with partial mule +that give you the a scalar right + + align:start position:0% +that give you the a scalar right + + + align:start position:0% +that give you the a scalar right +yeah okay so that'll give you a scale + + align:start position:0% +yeah okay so that'll give you a scale + + + align:start position:0% +yeah okay so that'll give you a scale +uh so so yeah you can understand that + + align:start position:0% +uh so so yeah you can understand that + + + align:start position:0% +uh so so yeah you can understand that +this is uh in both ways this Transformer + + align:start position:0% +this is uh in both ways this Transformer + + + align:start position:0% +this is uh in both ways this Transformer +the Firebase Transformer Vector is also + + align:start position:0% +the Firebase Transformer Vector is also + + + align:start position:0% +the Firebase Transformer Vector is also +related to here yeah yeah just I mean + + align:start position:0% +related to here yeah yeah just I mean + + + align:start position:0% +related to here yeah yeah just I mean +just yeah + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% +other questions + + + align:start position:0% +other questions +so yes + + align:start position:0% + + + + align:start position:0% + +like that we + + align:start position:0% +like that we + + + align:start position:0% +like that we +give like another children + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah yeah but then uh but but then you + + align:start position:0% +yeah yeah but then uh but but then you + + + align:start position:0% +yeah yeah but then uh but but then you +will have fourth size so four size will + + align:start position:0% +will have fourth size so four size will + + + align:start position:0% +will have fourth size so four size will +give you rise to an interacting CV yeah + + align:start position:0% +give you rise to an interacting CV yeah + + + align:start position:0% +give you rise to an interacting CV yeah +that's right here I'm writing down a a + + align:start position:0% +that's right here I'm writing down a a + + + align:start position:0% +that's right here I'm writing down a a +free Theory right now yeah + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so you can also see that this + + align:start position:0% +so so you can also see that this + + + align:start position:0% +so so you can also see that this +equation or or give rise to the drug + + align:start position:0% +equation or or give rise to the drug + + + align:start position:0% +equation or or give rise to the drug +equation just imagine PSI bar is + + align:start position:0% +equation just imagine PSI bar is + + + align:start position:0% +equation just imagine PSI bar is +independent of PSI because this + + align:start position:0% +independent of PSI because this + + + align:start position:0% +independent of PSI because this +corresponding to side dagger so if you + + align:start position:0% +corresponding to side dagger so if you + + + align:start position:0% +corresponding to side dagger so if you +do the variation of this one you just + + align:start position:0% +do the variation of this one you just + + + align:start position:0% +do the variation of this one you just +multiplicate the drug equation okay then + + align:start position:0% +multiplicate the drug equation okay then + + + align:start position:0% +multiplicate the drug equation okay then +you can also use to be checked by + + align:start position:0% +you can also use to be checked by + + + align:start position:0% +you can also use to be checked by +integration by part and if you want to + + align:start position:0% +integration by part and if you want to + + + align:start position:0% +integration by part and if you want to +reply you get the the compressed + + align:start position:0% +reply you get the the compressed + + + align:start position:0% +reply you get the the compressed +conjugate version of the drug equation + + align:start position:0% +conjugate version of the drug equation + + + align:start position:0% +conjugate version of the drug equation +and acting on the opposite bar okay + + align:start position:0% +and acting on the opposite bar okay + + + align:start position:0% +and acting on the opposite bar okay +so so now let me just say a few words on + + align:start position:0% +so so now let me just say a few words on + + + align:start position:0% +so so now let me just say a few words on +why you need the I here so you can check + + align:start position:0% +why you need the I here so you can check + + + align:start position:0% +why you need the I here so you can check +so so here I'm missing some relations + + align:start position:0% +so so here I'm missing some relations + + + align:start position:0% +so so here I'm missing some relations +again each of them you need to + + align:start position:0% +again each of them you need to + + + align:start position:0% +again each of them you need to +really write down the paper yourself + + align:start position:0% +really write down the paper yourself + + + align:start position:0% +really write down the paper yourself +stare at it maybe do a little bit + + align:start position:0% +stare at it maybe do a little bit + + + align:start position:0% +stare at it maybe do a little bit +derivation to get intuition about + + align:start position:0% +derivation to get intuition about + + + align:start position:0% +derivation to get intuition about +yourself okay right now I'm just writing + + align:start position:0% +yourself okay right now I'm just writing + + + align:start position:0% +yourself okay right now I'm just writing +down those duration down okay so you can + + align:start position:0% +down those duration down okay so you can + + + align:start position:0% +down those duration down okay so you can +also check yourself + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +side dagger + + align:start position:0% +side dagger + + + align:start position:0% +side dagger +okay + + align:start position:0% +okay + + + align:start position:0% +okay +again just go through all this scene + + align:start position:0% +again just go through all this scene + + + align:start position:0% +again just go through all this scene +you find it's equal to minus Side by + + align:start position:0% +you find it's equal to minus Side by + + + align:start position:0% +you find it's equal to minus Side by +upside + + align:start position:0% +upside + + + align:start position:0% +upside +okay so uh so this is just two lines + + align:start position:0% +okay so uh so this is just two lines + + + align:start position:0% +okay so uh so this is just two lines +here + + align:start position:0% +here + + + align:start position:0% +here +I will not write write them extricity to + + align:start position:0% +I will not write write them extricity to + + + align:start position:0% +I will not write write them extricity to +pull you + + align:start position:0% +pull you + + + align:start position:0% +pull you +and similarly you can check + + align:start position:0% +and similarly you can check + + + align:start position:0% +and similarly you can check +related to this the other term + + align:start position:0% +related to this the other term + + + align:start position:0% +related to this the other term +the gamma + + align:start position:0% +the gamma + + + align:start position:0% +the gamma +sidebar + + align:start position:0% +sidebar + + + align:start position:0% +sidebar +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +partial mu PSI + + align:start position:0% +partial mu PSI + + + align:start position:0% +partial mu PSI +if you take the dagger + + align:start position:0% +if you take the dagger + + + align:start position:0% +if you take the dagger +so here so this one is slightly more + + align:start position:0% +so here so this one is slightly more + + + align:start position:0% +so here so this one is slightly more +complicated okay uh but you can still + + align:start position:0% +complicated okay uh but you can still + + + align:start position:0% +complicated okay uh but you can still +just you can just walk it through you + + align:start position:0% +just you can just walk it through you + + + align:start position:0% +just you can just walk it through you +find it's just equal to negative of + + align:start position:0% +find it's just equal to negative of + + + align:start position:0% +find it's just equal to negative of +itself + + align:start position:0% + + + + align:start position:0% + +then plus total derivatives + + align:start position:0% +then plus total derivatives + + + align:start position:0% +then plus total derivatives +so this one is not you'd actually matter + + align:start position:0% +so this one is not you'd actually matter + + + align:start position:0% +so this one is not you'd actually matter +sign but you have to throw away some + + align:start position:0% +sign but you have to throw away some + + + align:start position:0% +sign but you have to throw away some +total derivatives so total derivatives + + align:start position:0% +total derivatives so total derivatives + + + align:start position:0% +total derivatives so total derivatives +which give you + + align:start position:0% +which give you + + + align:start position:0% +which give you +when you plug in the + + align:start position:0% +when you plug in the + + + align:start position:0% +when you plug in the +into the action they give rise user + + align:start position:0% +into the action they give rise user + + + align:start position:0% +into the action they give rise user +boundary terms and but they will always + + align:start position:0% +boundary terms and but they will always + + + align:start position:0% +boundary terms and but they will always +assume the field vanish at Infinity okay + + align:start position:0% +assume the field vanish at Infinity okay + + + align:start position:0% +assume the field vanish at Infinity okay +so so uh so so that explains why you + + align:start position:0% +so so uh so so that explains why you + + + align:start position:0% +so so uh so so that explains why you +leave this I because when you take the + + align:start position:0% +leave this I because when you take the + + + align:start position:0% +leave this I because when you take the +the complex conjugate of the the + + align:start position:0% +the complex conjugate of the the + + + align:start position:0% +the complex conjugate of the the +quantity here you always get the math + + align:start position:0% + + + + align:start position:0% + +good any questions + + align:start position:0% + + + + align:start position:0% + +good good okay so now it's getting a + + align:start position:0% +good good okay so now it's getting a + + + align:start position:0% +good good okay so now it's getting a +little bit awkward + + align:start position:0% +little bit awkward + + + align:start position:0% +little bit awkward +because our printer today broke + + align:start position:0% +because our printer today broke + + + align:start position:0% +because our printer today broke +so so I didn't spring enough of my notes + + align:start position:0% +so so I didn't spring enough of my notes + + + align:start position:0% +so so I didn't spring enough of my notes +so now I have to hide my computer to to + + align:start position:0% +so now I have to hide my computer to to + + + align:start position:0% +so now I have to hide my computer to to +remember my notes + + align:start position:0% +remember my notes + + + align:start position:0% +remember my notes +so + + align:start position:0% + + + + align:start position:0% + +one second + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +ah + + align:start position:0% + + + + align:start position:0% + +you have to find the location + + align:start position:0% +you have to find the location + + + align:start position:0% +you have to find the location +uh + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +so any questions on this + + align:start position:0% +so any questions on this + + + align:start position:0% +so any questions on this +Okay no Okay so now let's move to the + + align:start position:0% +Okay no Okay so now let's move to the + + + align:start position:0% +Okay no Okay so now let's move to the +last topic so now so this concludes our + + align:start position:0% +last topic so now so this concludes our + + + align:start position:0% +last topic so now so this concludes our +discussion of the Iraq equation + + align:start position:0% +discussion of the Iraq equation + + + align:start position:0% +discussion of the Iraq equation +so we have derived The Rock equation + + align:start position:0% +so we have derived The Rock equation + + + align:start position:0% +so we have derived The Rock equation +uh uh by uh and also we have discussed + + align:start position:0% +uh uh by uh and also we have discussed + + + align:start position:0% +uh uh by uh and also we have discussed +how what is quantities in the Rock + + align:start position:0% +how what is quantities in the Rock + + + align:start position:0% +how what is quantities in the Rock +equation should transform + + align:start position:0% +equation should transform + + + align:start position:0% +equation should transform +and and also the following the drug + + align:start position:0% +and and also the following the drug + + + align:start position:0% +and and also the following the drug +action okay + + align:start position:0% +action okay + + + align:start position:0% +action okay +so so that the next step + + align:start position:0% +so so that the next step + + + align:start position:0% +so so that the next step +the logic like step is to contact + + align:start position:0% +the logic like step is to contact + + + align:start position:0% +the logic like step is to contact +to go to the quantum field Series so + + align:start position:0% +to go to the quantum field Series so + + + align:start position:0% +to go to the quantum field Series so +right now so far everything is classical + + align:start position:0% +right now so far everything is classical + + + align:start position:0% +right now so far everything is classical +so so so so now the next step is that we + + align:start position:0% +so so so so now the next step is that we + + + align:start position:0% +so so so so now the next step is that we +want to quantize this Theory and when we + + align:start position:0% +want to quantize this Theory and when we + + + align:start position:0% +want to quantize this Theory and when we +contact this Theory we will see + + align:start position:0% +contact this Theory we will see + + + align:start position:0% +contact this Theory we will see +remarkable body formulas okay so we will + + align:start position:0% +remarkable body formulas okay so we will + + + align:start position:0% +remarkable body formulas okay so we will +see formula we will see probably + + align:start position:0% +see formula we will see probably + + + align:start position:0% +see formula we will see probably +principle + + align:start position:0% +principle + + + align:start position:0% +principle +and uh but but before but but as we said + + align:start position:0% +and uh but but before but but as we said + + + align:start position:0% +and uh but but before but but as we said +before + + align:start position:0% +before + + + align:start position:0% +before +that when we quantize the theory + + align:start position:0% +that when we quantize the theory + + + align:start position:0% +that when we quantize the theory +we first leads to uh the simplest way is + + align:start position:0% +we first leads to uh the simplest way is + + + align:start position:0% +we first leads to uh the simplest way is +to First find this all its classical + + align:start position:0% +to First find this all its classical + + + align:start position:0% +to First find this all its classical +Solutions + + align:start position:0% +Solutions + + + align:start position:0% +Solutions +and then then the classical Solutions + + align:start position:0% +and then then the classical Solutions + + + align:start position:0% +and then then the classical Solutions +then become solutions to the operator + + align:start position:0% +then become solutions to the operator + + + align:start position:0% +then become solutions to the operator +equations and then we can automatically + + align:start position:0% +equations and then we can automatically + + + align:start position:0% +equations and then we can automatically +quantize it okay so so then before we + + align:start position:0% +quantize it okay so so then before we + + + align:start position:0% +quantize it okay so so then before we +actually do the quantization uh it's + + align:start position:0% +actually do the quantization uh it's + + + align:start position:0% +actually do the quantization uh it's +better we try to find the the all the + + align:start position:0% +better we try to find the the all the + + + align:start position:0% +better we try to find the the all the +classical Solutions of the rock equation + + align:start position:0% +classical Solutions of the rock equation + + + align:start position:0% +classical Solutions of the rock equation +and so it's not like a kind golden + + align:start position:0% +and so it's not like a kind golden + + + align:start position:0% +and so it's not like a kind golden +equation we can just immediately write + + align:start position:0% +equation we can just immediately write + + + align:start position:0% +equation we can just immediately write +down the solutions and the direct + + align:start position:0% +down the solutions and the direct + + + align:start position:0% +down the solutions and the direct +equation is a little bit more intricate + + align:start position:0% +equation is a little bit more intricate + + + align:start position:0% +equation is a little bit more intricate +so we need to spend a little bit effort + + align:start position:0% +so we need to spend a little bit effort + + + align:start position:0% +so we need to spend a little bit effort +to uh to write down the solution to find + + align:start position:0% +to uh to write down the solution to find + + + align:start position:0% +to uh to write down the solution to find +all the solutions of the Dera equation + + align:start position:0% +all the solutions of the Dera equation + + + align:start position:0% +all the solutions of the Dera equation +okay so that's what you need to do + + align:start position:0% +okay so that's what you need to do + + + align:start position:0% +okay so that's what you need to do +unfortunately + + align:start position:0% +unfortunately + + + align:start position:0% +unfortunately +we're not going to finish today + + align:start position:0% +we're not going to finish today + + + align:start position:0% +we're not going to finish today +and then we will have a long spring + + align:start position:0% +and then we will have a long spring + + + align:start position:0% +and then we will have a long spring +break + + align:start position:0% +break + + + align:start position:0% +break +so + + align:start position:0% +so + + + align:start position:0% +so +so I hope you still remember what we + + align:start position:0% +so I hope you still remember what we + + + align:start position:0% +so I hope you still remember what we +talked about today when you come back + + align:start position:0% +talked about today when you come back + + + align:start position:0% +talked about today when you come back +um + + align:start position:0% +um + + + align:start position:0% +um +yeah + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +okay so now we have + + align:start position:0% +okay so now we have + + + align:start position:0% +okay so now we have +classical Solutions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so by construction the derived equation + + align:start position:0% + + + + align:start position:0% + +has Solutions + + align:start position:0% + + + + align:start position:0% + +we know must be propane to this ikx + + align:start position:0% +we know must be propane to this ikx + + + align:start position:0% +we know must be propane to this ikx +with + + align:start position:0% +with + + + align:start position:0% +with +K Square equal to minus M squared okay + + align:start position:0% +K Square equal to minus M squared okay + + + align:start position:0% +K Square equal to minus M squared okay +so this is by construction because we + + align:start position:0% +so this is by construction because we + + + align:start position:0% +so this is by construction because we +Square it + + align:start position:0% +Square it + + + align:start position:0% +Square it +we get the uh we get the uh crying + + align:start position:0% +we get the uh we get the uh crying + + + align:start position:0% +we get the uh we get the uh crying +golden equation so this K mu + + align:start position:0% +golden equation so this K mu + + + align:start position:0% +golden equation so this K mu +would be Omega k + + align:start position:0% + + + + align:start position:0% + +and okay okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +but but this is not enough + + align:start position:0% +but but this is not enough + + + align:start position:0% +but but this is not enough +because of the rock equation uh because + + align:start position:0% +because of the rock equation uh because + + + align:start position:0% +because of the rock equation uh because +PSI have four components okay so so this + + align:start position:0% +PSI have four components okay so so this + + + align:start position:0% +PSI have four components okay so so this +just determines one factor of it and we + + align:start position:0% +just determines one factor of it and we + + + align:start position:0% +just determines one factor of it and we +also have to determine its uh the + + align:start position:0% +also have to determine its uh the + + + align:start position:0% +also have to determine its uh the +behavior of all its four components okay + + align:start position:0% +behavior of all its four components okay + + + align:start position:0% +behavior of all its four components okay +so and so now that's we're going to do + + align:start position:0% +so and so now that's we're going to do + + + align:start position:0% +so and so now that's we're going to do +now + + align:start position:0% + + + + align:start position:0% + +so we will separate the solutions into + + align:start position:0% +so we will separate the solutions into + + + align:start position:0% +so we will separate the solutions into +two type + + align:start position:0% +two type + + + align:start position:0% +two type +so one type is we could I Plus + + align:start position:0% +so one type is we could I Plus + + + align:start position:0% +so one type is we could I Plus +X which equals one into U + + align:start position:0% +X which equals one into U + + + align:start position:0% +X which equals one into U +k x + + align:start position:0% +k x + + + align:start position:0% +k x +say expression ikx + + align:start position:0% +say expression ikx + + + align:start position:0% +say expression ikx +and another we call the PSI minus X + + align:start position:0% +and another we call the PSI minus X + + + align:start position:0% +and another we call the PSI minus X +which corresponding to v k x + + align:start position:0% +which corresponding to v k x + + + align:start position:0% +which corresponding to v k x +V K yeah sorry no X + + align:start position:0% +V K yeah sorry no X + + + align:start position:0% +V K yeah sorry no X +is + + align:start position:0% +is + + + align:start position:0% +is +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +so yeah so so UK VK they just they're + + align:start position:0% +so yeah so so UK VK they just they're + + + align:start position:0% +so yeah so so UK VK they just they're +all four components Spinners okay which + + align:start position:0% +all four components Spinners okay which + + + align:start position:0% +all four components Spinners okay which +have the same uh signal side because + + align:start position:0% +have the same uh signal side because + + + align:start position:0% +have the same uh signal side because +this is just some number + + align:start position:0% +this is just some number + + + align:start position:0% +this is just some number +so this because this is + + align:start position:0% +so this because this is + + + align:start position:0% +so this because this is +because K have the positive frequency + + align:start position:0% +because K have the positive frequency + + + align:start position:0% +because K have the positive frequency +okay so this is some kind of called the + + align:start position:0% +okay so this is some kind of called the + + + align:start position:0% +okay so this is some kind of called the +positive energy solution + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +but it's the same thing as in the scalar + + align:start position:0% +but it's the same thing as in the scalar + + + align:start position:0% +but it's the same thing as in the scalar +case they don't really + + align:start position:0% +case they don't really + + + align:start position:0% +case they don't really +there's not really uh when we contact + + align:start position:0% +there's not really uh when we contact + + + align:start position:0% +there's not really uh when we contact +the series doesn't really know elective + + align:start position:0% +the series doesn't really know elective + + + align:start position:0% +the series doesn't really know elective +energy excitations okay uh uh it's just + + align:start position:0% +energy excitations okay uh uh it's just + + + align:start position:0% +energy excitations okay uh uh it's just +a name okay so uh so we call the + + align:start position:0% +a name okay so uh so we call the + + + align:start position:0% +a name okay so uh so we call the +positive energy and negative energy + + align:start position:0% +positive energy and negative energy + + + align:start position:0% +positive energy and negative energy +system + + align:start position:0% +system + + + align:start position:0% +system +so data physical excitations always have + + align:start position:0% +so data physical excitations always have + + + align:start position:0% +so data physical excitations always have +positive message okay + + align:start position:0% +positive message okay + + + align:start position:0% +positive message okay +so under this UK + + align:start position:0% +so under this UK + + + align:start position:0% +so under this UK +and v k + + align:start position:0% +and v k + + + align:start position:0% +and v k +they're all four components + + align:start position:0% + + + + align:start position:0% + +complex vectors + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +uh yeah yeah right right yeah yeah uh + + align:start position:0% +uh yeah yeah right right yeah yeah uh + + + align:start position:0% +uh yeah yeah right right yeah yeah uh +yeah so this is just the basis of + + align:start position:0% +yeah so this is just the basis of + + + align:start position:0% +yeah so this is just the basis of +solutions indeed yeah we should label + + align:start position:0% +solutions indeed yeah we should label + + + align:start position:0% +solutions indeed yeah we should label +them back okay + + align:start position:0% + + + + align:start position:0% + +good so so this the uh so essentially + + align:start position:0% +good so so this the uh so essentially + + + align:start position:0% +good so so this the uh so essentially +you just + + align:start position:0% +you just + + + align:start position:0% +you just +in the scalar case you just expand in + + align:start position:0% +in the scalar case you just expand in + + + align:start position:0% +in the scalar case you just expand in +terms of the plane wave and then just + + align:start position:0% +terms of the plane wave and then just + + + align:start position:0% +terms of the plane wave and then just +get some constants + + align:start position:0% +get some constants + + + align:start position:0% +get some constants +so here is exactly to indicates uh we + + align:start position:0% +so here is exactly to indicates uh we + + + align:start position:0% +so here is exactly to indicates uh we +have a vector now we need to solve these + + align:start position:0% +have a vector now we need to solve these + + + align:start position:0% +have a vector now we need to solve these +vectors okay so our goal is to solve + + align:start position:0% +vectors okay so our goal is to solve + + + align:start position:0% +vectors okay so our goal is to solve +these vectors + + align:start position:0% + + + + align:start position:0% + +and then you just plug them into the + + align:start position:0% +and then you just plug them into the + + + align:start position:0% +and then you just plug them into the +direct equation okay just plug these two + + align:start position:0% +direct equation okay just plug these two + + + align:start position:0% +direct equation okay just plug these two +into the drug equation and then you get + + align:start position:0% +into the drug equation and then you get + + + align:start position:0% +into the drug equation and then you get +the equations for um + + align:start position:0% +the equations for um + + + align:start position:0% +the equations for um +for the UK and the and the v k okay + + align:start position:0% +for the UK and the and the v k okay + + + align:start position:0% +for the UK and the and the v k okay +I know I will also suppress the K in the + + align:start position:0% +I know I will also suppress the K in the + + + align:start position:0% +I know I will also suppress the K in the +in the U and the V so so just for + + align:start position:0% +in the U and the V so so just for + + + align:start position:0% +in the U and the V so so just for +rotational simplicities okay so when you + + align:start position:0% +rotational simplicities okay so when you + + + align:start position:0% +rotational simplicities okay so when you +have the gamma mu + + align:start position:0% +have the gamma mu + + + align:start position:0% +have the gamma mu +100 mu minus m + + align:start position:0% +100 mu minus m + + + align:start position:0% +100 mu minus m +PSI equal to zero you just plug the PSI + + align:start position:0% +PSI equal to zero you just plug the PSI + + + align:start position:0% +PSI equal to zero you just plug the PSI +plus Prime minus in and then you find + + align:start position:0% +plus Prime minus in and then you find + + + align:start position:0% +plus Prime minus in and then you find +the following + + align:start position:0% +the following + + + align:start position:0% +the following +equations for U + + align:start position:0% +equations for U + + + align:start position:0% +equations for U +if you get i k slash minus m u equal to + + align:start position:0% +if you get i k slash minus m u equal to + + + align:start position:0% +if you get i k slash minus m u equal to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +ik slash + + align:start position:0% +ik slash + + + align:start position:0% +ik slash +and minus + + align:start position:0% +and minus + + + align:start position:0% +and minus +yeah I think let me just double check + + align:start position:0% +yeah I think let me just double check + + + align:start position:0% +yeah I think let me just double check +the sign yeah indeed so you get okay + + align:start position:0% +the sign yeah indeed so you get okay + + + align:start position:0% +the sign yeah indeed so you get okay +slash plus and + + align:start position:0% +slash plus and + + + align:start position:0% +slash plus and +V equal to zero okay so you get these + + align:start position:0% +V equal to zero okay so you get these + + + align:start position:0% +V equal to zero okay so you get these +two increase + + align:start position:0% +two increase + + + align:start position:0% +two increase +so our goal is just to solve those + + align:start position:0% +so our goal is just to solve those + + + align:start position:0% +so our goal is just to solve those +equations okay and the case rise just as + + align:start position:0% +equations okay and the case rise just as + + + align:start position:0% +equations okay and the case rise just as +defined before + + align:start position:0% +defined before + + + align:start position:0% +defined before +um + + align:start position:0% +um + + + align:start position:0% +um +uh it just defined as in the partial + + align:start position:0% +uh it just defined as in the partial + + + align:start position:0% +uh it just defined as in the partial +slice okay slash + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so you can also work out their complex + + align:start position:0% +so you can also work out their complex + + + align:start position:0% +so you can also work out their complex +conjugates so let me just write down the + + align:start position:0% +conjugates so let me just write down the + + + align:start position:0% +conjugates so let me just write down the +uh uh the equations because sometimes + + align:start position:0% +uh uh the equations because sometimes + + + align:start position:0% +uh uh the equations because sometimes +they will be used later okay so the U + + align:start position:0% +they will be used later okay so the U + + + align:start position:0% +they will be used later okay so the U +Bar + + align:start position:0% + + + + align:start position:0% + +minus m equal to zero the complex + + align:start position:0% +minus m equal to zero the complex + + + align:start position:0% +minus m equal to zero the complex +conjugate and V bar + + align:start position:0% +conjugate and V bar + + + align:start position:0% +conjugate and V bar +okay slash plus m + + align:start position:0% + + + + align:start position:0% + +so now let's try to work out the uh UK + + align:start position:0% +so now let's try to work out the uh UK + + + align:start position:0% +so now let's try to work out the uh UK +and the VK + + align:start position:0% + + + + align:start position:0% + +by solving those equations + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +so we do this by + + align:start position:0% +so we do this by + + + align:start position:0% +so we do this by +you can in principle do it by Brute + + align:start position:0% +you can in principle do it by Brute + + + align:start position:0% +you can in principle do it by Brute +Force + + align:start position:0% +Force + + + align:start position:0% +Force +so after all they just + + align:start position:0% +so after all they just + + + align:start position:0% +so after all they just +these are just four by four equations + + align:start position:0% +these are just four by four equations + + + align:start position:0% +these are just four by four equations +okay 4x4 Matrix equations uh just linear + + align:start position:0% +okay 4x4 Matrix equations uh just linear + + + align:start position:0% +okay 4x4 Matrix equations uh just linear +algebra okay you can in principle become + + align:start position:0% +algebra okay you can in principle become + + + align:start position:0% +algebra okay you can in principle become +more solve it + + align:start position:0% +more solve it + + + align:start position:0% +more solve it +but the physics is often are lazy okay + + align:start position:0% +but the physics is often are lazy okay + + + align:start position:0% +but the physics is often are lazy okay +so we often still even for the problem + + align:start position:0% +so we often still even for the problem + + + align:start position:0% +so we often still even for the problem +you can you can solve we still look for + + align:start position:0% +you can you can solve we still look for + + + align:start position:0% +you can you can solve we still look for +shortcuts + + align:start position:0% +shortcuts + + + align:start position:0% +shortcuts +and so in this case there are two + + align:start position:0% +and so in this case there are two + + + align:start position:0% +and so in this case there are two +possible shortcuts there are two + + align:start position:0% +possible shortcuts there are two + + + align:start position:0% +possible shortcuts there are two +possible ways we can do okay and uh so + + align:start position:0% +possible ways we can do okay and uh so + + + align:start position:0% +possible ways we can do okay and uh so +so let me describe both ways + + align:start position:0% +so let me describe both ways + + + align:start position:0% +so let me describe both ways +uh actually I think we only have time to + + align:start position:0% +uh actually I think we only have time to + + + align:start position:0% +uh actually I think we only have time to +describe one way + + align:start position:0% +describe one way + + + align:start position:0% +describe one way +uh so + + align:start position:0% +uh so + + + align:start position:0% +uh so +so to find the + + align:start position:0% + + + + align:start position:0% + +explicit form + + align:start position:0% + + + + align:start position:0% + +of u and v + + align:start position:0% + + + + align:start position:0% + +so so one simple thing to do is let's + + align:start position:0% +so so one simple thing to do is let's + + + align:start position:0% +so so one simple thing to do is let's +just consider in the simple case + + align:start position:0% +just consider in the simple case + + + align:start position:0% +just consider in the simple case +say consider the particle is at rest + + align:start position:0% + + + + align:start position:0% + +when the particle is at rest then the + + align:start position:0% +when the particle is at rest then the + + + align:start position:0% +when the particle is at rest then the +Omega is just equal to m + + align:start position:0% +Omega is just equal to m + + + align:start position:0% +Omega is just equal to m +and then k equal to zero + + align:start position:0% +and then k equal to zero + + + align:start position:0% +and then k equal to zero +okay and then that equation just become + + align:start position:0% +okay and then that equation just become + + + align:start position:0% +okay and then that equation just become +I + + align:start position:0% +I + + + align:start position:0% +I +M comma zero + + align:start position:0% +M comma zero + + + align:start position:0% +M comma zero +minus m + + align:start position:0% +minus m + + + align:start position:0% +minus m +U equal to zero and I + + align:start position:0% +U equal to zero and I + + + align:start position:0% +U equal to zero and I +M comma zero plus m + + align:start position:0% +M comma zero plus m + + + align:start position:0% +M comma zero plus m +V equal to zero okay + + align:start position:0% + + + + align:start position:0% + +I think + + align:start position:0% +I think + + + align:start position:0% +I think +do I + + align:start position:0% +do I + + + align:start position:0% +do I +um + + align:start position:0% + + + + align:start position:0% + +so yeah I think let me + + align:start position:0% +so yeah I think let me + + + align:start position:0% +so yeah I think let me +oh yeah yeah sorry I should have a minus + + align:start position:0% +oh yeah yeah sorry I should have a minus + + + align:start position:0% +oh yeah yeah sorry I should have a minus +sign here + + align:start position:0% +sign here + + + align:start position:0% +sign here +because of the uh because of the um is + + align:start position:0% +because of the uh because of the um is + + + align:start position:0% +because of the uh because of the um is +the K upper index + + align:start position:0% +the K upper index + + + align:start position:0% +the K upper index +so it's the K up index equal to Omega + + align:start position:0% +so it's the K up index equal to Omega + + + align:start position:0% +so it's the K up index equal to Omega +then called K low index equal to minus + + align:start position:0% +then called K low index equal to minus + + + align:start position:0% +then called K low index equal to minus +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and here when we contract with gamma + + align:start position:0% +and here when we contract with gamma + + + align:start position:0% +and here when we contract with gamma +zero we use the low index so so we have + + align:start position:0% +zero we use the low index so so we have + + + align:start position:0% +zero we use the low index so so we have +a minus sign here + + align:start position:0% + + + + align:start position:0% + +okay so so essentially this just becomes + + align:start position:0% +okay so so essentially this just becomes + + + align:start position:0% +okay so so essentially this just becomes +so M can be canceled on both sides so + + align:start position:0% +so M can be canceled on both sides so + + + align:start position:0% +so M can be canceled on both sides so +essentially just become the + + align:start position:0% +essentially just become the + + + align:start position:0% +essentially just become the +um I comma zero U + + align:start position:0% +um I comma zero U + + + align:start position:0% +um I comma zero U +equal to manage U + + align:start position:0% +equal to manage U + + + align:start position:0% +equal to manage U +and I comma 0 V + + align:start position:0% +and I comma 0 V + + + align:start position:0% +and I comma 0 V +equal to + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so this tells you + + align:start position:0% + + + + align:start position:0% + +so this just tells you essentially gamma + + align:start position:0% +so this just tells you essentially gamma + + + align:start position:0% +so this just tells you essentially gamma +u u + + align:start position:0% + + + + align:start position:0% + +is going back to V and V they are just + + align:start position:0% +is going back to V and V they are just + + + align:start position:0% +is going back to V and V they are just +essentially diagonal Vector so comma + + align:start position:0% +essentially diagonal Vector so comma + + + align:start position:0% +essentially diagonal Vector so comma +zero + + align:start position:0% +zero + + + align:start position:0% +zero +okay they just argument also comma zero + + align:start position:0% +okay they just argument also comma zero + + + align:start position:0% +okay they just argument also comma zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so so let's just now to write the + + align:start position:0% +and so so let's just now to write the + + + align:start position:0% +and so so let's just now to write the +mix 3 c 3 so so now let's use the + + align:start position:0% +mix 3 c 3 so so now let's use the + + + align:start position:0% +mix 3 c 3 so so now let's use the +explicit representation of gamma + + align:start position:0% +explicit representation of gamma + + + align:start position:0% +explicit representation of gamma +matrices + + align:start position:0% +matrices + + + align:start position:0% +matrices +yeah let me just copy this + + align:start position:0% +yeah let me just copy this + + + align:start position:0% +yeah let me just copy this +so so now let's use this representation + + align:start position:0% +so so now let's use this representation + + + align:start position:0% +so so now let's use this representation +with the gamma zero + + align:start position:0% +with the gamma zero + + + align:start position:0% +with the gamma zero +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +I zero zero I minus I and then gamma I + + align:start position:0% +I zero zero I minus I and then gamma I + + + align:start position:0% +I zero zero I minus I and then gamma I +is equal to zero I think on my I + + align:start position:0% +is equal to zero I think on my I + + + align:start position:0% +is equal to zero I think on my I +minus I Sigma I zero okay + + align:start position:0% + + + + align:start position:0% + +and then now if you plug in this comma + + align:start position:0% +and then now if you plug in this comma + + + align:start position:0% +and then now if you plug in this comma +zero into those equations + + align:start position:0% + + + + align:start position:0% + +and then you find the equation for U and + + align:start position:0% +and then you find the equation for U and + + + align:start position:0% +and then you find the equation for U and +B become very simple + + align:start position:0% +B become very simple + + + align:start position:0% +B become very simple +for the U just become zero zero zero one + + align:start position:0% +for the U just become zero zero zero one + + + align:start position:0% +for the U just become zero zero zero one +U equal to zero so again this is two by + + align:start position:0% +U equal to zero so again this is two by + + + align:start position:0% +U equal to zero so again this is two by +two blocks okay because this here is two + + align:start position:0% +two blocks okay because this here is two + + + align:start position:0% +two blocks okay because this here is two +by two blocks + + align:start position:0% +by two blocks + + + align:start position:0% +by two blocks +and uh and for V + + align:start position:0% + + + + align:start position:0% + +just the one zero zero + + align:start position:0% +just the one zero zero + + + align:start position:0% +just the one zero zero +V equal to zero + + align:start position:0% +V equal to zero + + + align:start position:0% +V equal to zero +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that means + + align:start position:0% +so that means + + + align:start position:0% +so that means +you you can just take it to be the upper + + align:start position:0% +you you can just take it to be the upper + + + align:start position:0% +you you can just take it to be the upper +so that means the solution of this + + align:start position:0% +so that means the solution of this + + + align:start position:0% +so that means the solution of this +equation + + align:start position:0% + + + + align:start position:0% + +so that means that the solution of this + + align:start position:0% +so that means that the solution of this + + + align:start position:0% +so that means that the solution of this +equation for U + + align:start position:0% +equation for U + + + align:start position:0% +equation for U +so now let me write the upper index 0 + + align:start position:0% +so now let me write the upper index 0 + + + align:start position:0% +so now let me write the upper index 0 +means that this is for the for the zero + + align:start position:0% +means that this is for the for the zero + + + align:start position:0% +means that this is for the for the zero +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +so here we can just choose cubic PSI + + align:start position:0% +so here we can just choose cubic PSI + + + align:start position:0% +so here we can just choose cubic PSI +zero so PSI is some arbitrary two Vector + + align:start position:0% +zero so PSI is some arbitrary two Vector + + + align:start position:0% +zero so PSI is some arbitrary two Vector +okay + + align:start position:0% +okay + + + align:start position:0% +okay +for V we can just choose the lower + + align:start position:0% + + + + align:start position:0% + +zero ETA + + align:start position:0% +zero ETA + + + align:start position:0% +zero ETA +okay so PSI + + align:start position:0% +okay so PSI + + + align:start position:0% +okay so PSI +ETA arbitrary + + align:start position:0% + + + + align:start position:0% + +two vectors two complex two complex + + align:start position:0% +two vectors two complex two complex + + + align:start position:0% +two vectors two complex two complex +vectors + + align:start position:0% +vectors + + + align:start position:0% +vectors +a two vector + + align:start position:0% + + + + align:start position:0% + +two component of vectors + + align:start position:0% +two component of vectors + + + align:start position:0% +two component of vectors +two components + + align:start position:0% +two components + + + align:start position:0% +two components +complex vectors + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so once you have u0 and V 0 and we can + + align:start position:0% +so once you have u0 and V 0 and we can + + + align:start position:0% +so once you have u0 and V 0 and we can +choose the basis + + align:start position:0% +choose the basis + + + align:start position:0% +choose the basis +for example U zero + + align:start position:0% +for example U zero + + + align:start position:0% +for example U zero +one equal to zero one one zero zero zero + + align:start position:0% +one equal to zero one one zero zero zero + + + align:start position:0% +one equal to zero one one zero zero zero +and you + + align:start position:0% +and you + + + align:start position:0% +and you +zero two equal to zero one zero zero and + + align:start position:0% +zero two equal to zero one zero zero and + + + align:start position:0% +zero two equal to zero one zero zero and +similarly for V zero + + align:start position:0% +similarly for V zero + + + align:start position:0% +similarly for V zero +one and V 0 2 okay so you can choose to + + align:start position:0% +one and V 0 2 okay so you can choose to + + + align:start position:0% +one and V 0 2 okay so you can choose to +be here one + + align:start position:0% + + + + align:start position:0% + +okay so you can just choose as a basis + + align:start position:0% +okay so you can just choose as a basis + + + align:start position:0% +okay so you can just choose as a basis +you can just choose the the + + align:start position:0% + + + + align:start position:0% + +and now once you have + + align:start position:0% + + + + align:start position:0% + +so once you have + + align:start position:0% + + + + align:start position:0% + +so once you have the vector at k equal + + align:start position:0% +so once you have the vector at k equal + + + align:start position:0% +so once you have the vector at k equal +to zero for General K what do you do + + align:start position:0% +to zero for General K what do you do + + + align:start position:0% +to zero for General K what do you do +yes yes to a Lawrence post so we know + + align:start position:0% +yes yes to a Lawrence post so we know + + + align:start position:0% +yes yes to a Lawrence post so we know +the Matrix S + + align:start position:0% +the Matrix S + + + align:start position:0% +the Matrix S +and then you just for the general k + + align:start position:0% +and then you just for the general k + + + align:start position:0% +and then you just for the general k +you just s + + align:start position:0% +you just s + + + align:start position:0% +you just s +U zero + + align:start position:0% +U zero + + + align:start position:0% +U zero +and the v k + + align:start position:0% +and the v k + + + align:start position:0% +and the v k +s v0 + + align:start position:0% +s v0 + + + align:start position:0% +s v0 +okay and then you can find the behavior + + align:start position:0% +okay and then you can find the behavior + + + align:start position:0% +okay and then you can find the behavior +as general k + + align:start position:0% +as general k + + + align:start position:0% +as general k +but this is work but this is easily said + + align:start position:0% +but this is work but this is easily said + + + align:start position:0% +but this is work but this is easily said +than two okay + + align:start position:0% +than two okay + + + align:start position:0% +than two okay +two this actually is not quite easy + + align:start position:0% +two this actually is not quite easy + + + align:start position:0% +two this actually is not quite easy +okay even though this sounds like a + + align:start position:0% +okay even though this sounds like a + + + align:start position:0% +okay even though this sounds like a +great idea okay let's find the zero + + align:start position:0% +great idea okay let's find the zero + + + align:start position:0% +great idea okay let's find the zero +momentum and then let's just do a boost + + align:start position:0% +momentum and then let's just do a boost + + + align:start position:0% +momentum and then let's just do a boost +but but this time it's still a little + + align:start position:0% +but but this time it's still a little + + + align:start position:0% +but but this time it's still a little +bit tedious + + align:start position:0% +bit tedious + + + align:start position:0% +bit tedious +but it's still uh + + align:start position:0% +but it's still uh + + + align:start position:0% +but it's still uh +it's doable and a little bit simpler + + align:start position:0% +it's doable and a little bit simpler + + + align:start position:0% +it's doable and a little bit simpler +than then solve the original equation by + + align:start position:0% +than then solve the original equation by + + + align:start position:0% +than then solve the original equation by +Brute Force okay and but it is again + + align:start position:0% +Brute Force okay and but it is again + + + align:start position:0% +Brute Force okay and but it is again +still another simpler methods + + align:start position:0% +still another simpler methods + + + align:start position:0% +still another simpler methods +which you can actually discuss the + + align:start position:0% +which you can actually discuss the + + + align:start position:0% +which you can actually discuss the +answer you don't have to do any + + align:start position:0% +answer you don't have to do any + + + align:start position:0% +answer you don't have to do any +calculation you can just guess the + + align:start position:0% +calculation you can just guess the + + + align:start position:0% +calculation you can just guess the +answer + + align:start position:0% +answer + + + align:start position:0% +answer +cast the solution for the full equation + + align:start position:0% +cast the solution for the full equation + + + align:start position:0% +cast the solution for the full equation +okay and I don't I think we don't have + + align:start position:0% +okay and I don't I think we don't have + + + align:start position:0% +okay and I don't I think we don't have +time to talk about it today and so we + + align:start position:0% +time to talk about it today and so we + + + align:start position:0% +time to talk about it today and so we +will talk about it next time + + align:start position:0% +will talk about it next time + + + align:start position:0% +will talk about it next time +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +so so hopefully you still remember what + + align:start position:0% +so so hopefully you still remember what + + + align:start position:0% +so so hopefully you still remember what +we talked about today when we come back + + align:start position:0% +we talked about today when we come back + + + align:start position:0% +we talked about today when we come back +and uh hope you have a good spring break \ No newline at end of file diff --git a/ZPmBMd6OZeQ.txt b/ZPmBMd6OZeQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..350d455c7eb0705e6559cc7a91c6ce3b33f4ecb2 --- /dev/null +++ b/ZPmBMd6OZeQ.txt @@ -0,0 +1,7403 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay ready to go okay so uh + + align:start position:0% +ocw.mit.edu okay ready to go okay so uh + + + align:start position:0% +ocw.mit.edu okay ready to go okay so uh +first of all to say thank you to several + + align:start position:0% +first of all to say thank you to several + + + align:start position:0% +first of all to say thank you to several +people in the class who sent uh codes to + + align:start position:0% +people in the class who sent uh codes to + + + align:start position:0% +people in the class who sent uh codes to +find these um + + align:start position:0% +find these um + + + align:start position:0% +find these um +wavefronts when a shock a step function + + align:start position:0% +wavefronts when a shock a step function + + + align:start position:0% +wavefronts when a shock a step function +is moving along with velocity C uh I had + + align:start position:0% +is moving along with velocity C uh I had + + + align:start position:0% +is moving along with velocity C uh I had +roughly drawn uh what these three + + align:start position:0% +roughly drawn uh what these three + + + align:start position:0% +roughly drawn uh what these three +methods produce but it was much better + + align:start position:0% +methods produce but it was much better + + + align:start position:0% +methods produce but it was much better +to see it in Mr Sakura's movie that's on + + align:start position:0% +to see it in Mr Sakura's movie that's on + + + align:start position:0% +to see it in Mr Sakura's movie that's on +the 18086 site uh and sure enough behind + + align:start position:0% +the 18086 site uh and sure enough behind + + + align:start position:0% +the 18086 site uh and sure enough behind +the moving front is a is a + + align:start position:0% +the moving front is a is a + + + align:start position:0% +the moving front is a is a +overshoot that reminds us of the Gibbs + + align:start position:0% +overshoot that reminds us of the Gibbs + + + align:start position:0% +overshoot that reminds us of the Gibbs +phenomenon from LAX + + align:start position:0% +phenomenon from LAX + + + align:start position:0% +phenomenon from LAX +wend and I think it's sort of + + align:start position:0% +wend and I think it's sort of + + + align:start position:0% +wend and I think it's sort of +unavoidable if we have a negative if + + align:start position:0% +unavoidable if we have a negative if + + + align:start position:0% +unavoidable if we have a negative if +because one of the three coefficients at + + align:start position:0% +because one of the three coefficients at + + + align:start position:0% +because one of the three coefficients at +the previous time is negative for Lex + + align:start position:0% +the previous time is negative for Lex + + + align:start position:0% +the previous time is negative for Lex +wend that's how it gets its second order + + align:start position:0% +wend that's how it gets its second order + + + align:start position:0% +wend that's how it gets its second order +accuracy and we see that better accuracy + + align:start position:0% +accuracy and we see that better accuracy + + + align:start position:0% +accuracy and we see that better accuracy +in a much steeper much steeper profile + + align:start position:0% +in a much steeper much steeper profile + + + align:start position:0% +in a much steeper much steeper profile +and then LAX friedricks if you noticed + + align:start position:0% +and then LAX friedricks if you noticed + + + align:start position:0% +and then LAX friedricks if you noticed +has a sort of uh Jagged uh profile and I + + align:start position:0% +has a sort of uh Jagged uh profile and I + + + align:start position:0% +has a sort of uh Jagged uh profile and I +guess well maybe you realized why that + + align:start position:0% +guess well maybe you realized why that + + + align:start position:0% +guess well maybe you realized why that +would be somehow LAX + + align:start position:0% +would be somehow LAX + + + align:start position:0% +would be somehow LAX +friedrick uh is kind of operates on a + + align:start position:0% +friedrick uh is kind of operates on a + + + align:start position:0% +friedrick uh is kind of operates on a +staggered grid we'll see actually well + + align:start position:0% +staggered grid we'll see actually well + + + align:start position:0% +staggered grid we'll see actually well +I've I've drawn a staggered grid here so + + align:start position:0% +I've I've drawn a staggered grid here so + + + align:start position:0% +I've I've drawn a staggered grid here so +I can say what I mean LAX friedr + + align:start position:0% +I can say what I mean LAX friedr + + + align:start position:0% +I can say what I mean LAX friedr +computes this value from the two earlier + + align:start position:0% +computes this value from the two earlier + + + align:start position:0% +computes this value from the two earlier +values there and then at the next level + + align:start position:0% +values there and then at the next level + + + align:start position:0% +values there and then at the next level +again and so forth so that actually LAX + + align:start position:0% +again and so forth so that actually LAX + + + align:start position:0% +again and so forth so that actually LAX +LAX friedricks only + + align:start position:0% +LAX friedricks only + + + align:start position:0% +LAX friedricks only +uses is using two staggered grids + + align:start position:0% +uses is using two staggered grids + + + align:start position:0% +uses is using two staggered grids +separately and I think and normally we + + align:start position:0% +separately and I think and normally we + + + align:start position:0% +separately and I think and normally we +we with LA frieds we called that n plus + + align:start position:0% +we with LA frieds we called that n plus + + + align:start position:0% +we with LA frieds we called that n plus +one and n plus2 and n plus 3 but the + + align:start position:0% +one and n plus2 and n plus 3 but the + + + align:start position:0% +one and n plus2 and n plus 3 but the +picture is still right so I think that's + + align:start position:0% +picture is still right so I think that's + + + align:start position:0% +picture is still right so I think that's +probably responsible for what you see + + align:start position:0% +probably responsible for what you see + + + align:start position:0% +probably responsible for what you see +that that there's there there's two + + align:start position:0% +that that there's there there's two + + + align:start position:0% +that that there's there there's two +waves uh two fronts uh right one delt + + align:start position:0% +waves uh two fronts uh right one delt + + + align:start position:0% +waves uh two fronts uh right one delt +Delta X away from each other and finally + + align:start position:0% +Delta X away from each other and finally + + + align:start position:0% +Delta X away from each other and finally +upwind is also smeared out uh I I guess + + align:start position:0% +upwind is also smeared out uh I I guess + + + align:start position:0% +upwind is also smeared out uh I I guess +I I was so pleased to see these um + + align:start position:0% +I I was so pleased to see these um + + + align:start position:0% +I I was so pleased to see these um +actually showing on the website and that + + align:start position:0% +actually showing on the website and that + + + align:start position:0% +actually showing on the website and that +it makes me think of more questions and + + align:start position:0% +it makes me think of more questions and + + + align:start position:0% +it makes me think of more questions and +maybe you too um first of + + align:start position:0% +maybe you too um first of + + + align:start position:0% +maybe you too um first of +all um as time goes forward + + align:start position:0% +all um as time goes forward + + + align:start position:0% +all um as time goes forward +we see this bump beginning to appear so + + align:start position:0% +we see this bump beginning to appear so + + + align:start position:0% +we see this bump beginning to appear so +am I right in thinking that it reaches a + + align:start position:0% +am I right in thinking that it reaches a + + + align:start position:0% +am I right in thinking that it reaches a +certain height and and stays there so + + align:start position:0% +certain height and and stays there so + + + align:start position:0% +certain height and and stays there so +that I guess I'm thinking about sort of + + align:start position:0% +that I guess I'm thinking about sort of + + + align:start position:0% +that I guess I'm thinking about sort of +further questions because every time you + + align:start position:0% +further questions because every time you + + + align:start position:0% +further questions because every time you +do a numerical experiment good good + + align:start position:0% +do a numerical experiment good good + + + align:start position:0% +do a numerical experiment good good +additional questions show up and so I'm + + align:start position:0% +additional questions show up and so I'm + + + align:start position:0% +additional questions show up and so I'm +wondering as this wavefront forms is + + align:start position:0% +wondering as this wavefront forms is + + + align:start position:0% +wondering as this wavefront forms is +characteristic profile for these three + + align:start position:0% +characteristic profile for these three + + + align:start position:0% +characteristic profile for these three +methods um first of all do they does + + align:start position:0% +methods um first of all do they does + + + align:start position:0% +methods um first of all do they does +that profile settle down to a steady + + align:start position:0% +that profile settle down to a steady + + + align:start position:0% +that profile settle down to a steady +profile ultimately it'd be great to be + + align:start position:0% +profile ultimately it'd be great to be + + + align:start position:0% +profile ultimately it'd be great to be +able to predict what it would + + align:start position:0% +able to predict what it would + + + align:start position:0% +able to predict what it would +be uh and in particular does that bump + + align:start position:0% +be uh and in particular does that bump + + + align:start position:0% +be uh and in particular does that bump +reach a certain height because you can + + align:start position:0% +reach a certain height because you can + + + align:start position:0% +reach a certain height because you can +see it just barely forming and then you + + align:start position:0% +see it just barely forming and then you + + + align:start position:0% +see it just barely forming and then you +see it growing to a certain point and + + align:start position:0% +see it growing to a certain point and + + + align:start position:0% +see it growing to a certain point and +then when the movie + + align:start position:0% +then when the movie + + + align:start position:0% +then when the movie +ends fortunately it plots this picture + + align:start position:0% +ends fortunately it plots this picture + + + align:start position:0% +ends fortunately it plots this picture +and you really see the profile and you + + align:start position:0% +and you really see the profile and you + + + align:start position:0% +and you really see the profile and you +can actually see if you look closely + + align:start position:0% +can actually see if you look closely + + + align:start position:0% +can actually see if you look closely +that it goes above one again and + + align:start position:0% +that it goes above one again and + + + align:start position:0% +that it goes above one again and +probably more um + + align:start position:0% +probably more um + + + align:start position:0% +probably more um +so uh so that would be does it approach + + align:start position:0% +so uh so that would be does it approach + + + align:start position:0% +so uh so that would be does it approach +a steady + + align:start position:0% +a steady + + + align:start position:0% +a steady +profile does that height settle + + align:start position:0% +profile does that height settle + + + align:start position:0% +profile does that height settle +down well it' be fantastic to be able to + + align:start position:0% +down well it' be fantastic to be able to + + + align:start position:0% +down well it' be fantastic to be able to +predict that height and and for example + + align:start position:0% +predict that height and and for example + + + align:start position:0% +predict that height and and for example +you always want to know how do things + + align:start position:0% +you always want to know how do things + + + align:start position:0% +you always want to know how do things +depend on the parameter and the one + + align:start position:0% +depend on the parameter and the one + + + align:start position:0% +depend on the parameter and the one +parameter we have in this problem is r c + + align:start position:0% +parameter we have in this problem is r c + + + align:start position:0% +parameter we have in this problem is r c +delta T over Delta X if I change r I'm + + align:start position:0% +delta T over Delta X if I change r I'm + + + align:start position:0% +delta T over Delta X if I change r I'm +changing all the + + align:start position:0% +changing all the + + + align:start position:0% +changing all the +coefficients if I changed R to be + + align:start position:0% +coefficients if I changed R to be + + + align:start position:0% +coefficients if I changed R to be +exactly one then the profile would be + + align:start position:0% +exactly one then the profile would be + + + align:start position:0% +exactly one then the profile would be +perfect that right that's the golden + + align:start position:0% +perfect that right that's the golden + + + align:start position:0% +perfect that right that's the golden +ratio r equal 1 uh I would be + + align:start position:0% +ratio r equal 1 uh I would be + + + align:start position:0% +ratio r equal 1 uh I would be +Computing that value exactly from this + + align:start position:0% +Computing that value exactly from this + + + align:start position:0% +Computing that value exactly from this +value at exactly the right slope on the + + align:start position:0% +value at exactly the right slope on the + + + align:start position:0% +value at exactly the right slope on the +characteristic and uh + + align:start position:0% +characteristic and uh + + + align:start position:0% +characteristic and uh +Perfection but now as R goes away from + + align:start position:0% +Perfection but now as R goes away from + + + align:start position:0% +Perfection but now as R goes away from +one I presume it goes down below one of + + align:start position:0% +one I presume it goes down below one of + + + align:start position:0% +one I presume it goes down below one of +course if it goes above one catastrophe + + align:start position:0% +course if it goes above one catastrophe + + + align:start position:0% +course if it goes above one catastrophe +if it goes below one I presume the + + align:start position:0% +if it goes below one I presume the + + + align:start position:0% +if it goes below one I presume the +bump begins to appear goes higher I I + + align:start position:0% +bump begins to appear goes higher I I + + + align:start position:0% +bump begins to appear goes higher I I +don't know could could you see how the + + align:start position:0% +don't know could could you see how the + + + align:start position:0% +don't know could could you see how the +dependence on R appears and and then I + + align:start position:0% +dependence on R appears and and then I + + + align:start position:0% +dependence on R appears and and then I +can even suggest one more thing which is + + align:start position:0% +can even suggest one more thing which is + + + align:start position:0% +can even suggest one more thing which is +where what let's put a fourth guy onto + + align:start position:0% +where what let's put a fourth guy onto + + + align:start position:0% +where what let's put a fourth guy onto +this + + align:start position:0% +this + + + align:start position:0% +this +um onto this um + + align:start position:0% +um onto this um + + + align:start position:0% +um onto this um +picture which would be Leap Frog Leap + + align:start position:0% +picture which would be Leap Frog Leap + + + align:start position:0% +picture which would be Leap Frog Leap +Frog for first order equation so let me + + align:start position:0% +Frog for first order equation so let me + + + align:start position:0% +Frog for first order equation so let me +just put down below what that would be + + align:start position:0% +just put down below what that would be + + + align:start position:0% +just put down below what that would be +so it would be on that kind of a + + align:start position:0% +so it would be on that kind of a + + + align:start position:0% +so it would be on that kind of a +staggered grid uh a new value at time n + + align:start position:0% +staggered grid uh a new value at time n + + + align:start position:0% +staggered grid uh a new value at time n ++ one would come from these at time n + + align:start position:0% ++ one would come from these at time n + + + align:start position:0% ++ one would come from these at time n +really and this one at time n minus one + + align:start position:0% +really and this one at time n minus one + + + align:start position:0% +really and this one at time n minus one +so Lea frog would you you think of it + + align:start position:0% +so Lea frog would you you think of it + + + align:start position:0% +so Lea frog would you you think of it +right away I use a center + + align:start position:0% +right away I use a center + + + align:start position:0% +right away I use a center +difference in time u j n + 1 - UJ n -1 / + + align:start position:0% +difference in time u j n + 1 - UJ n -1 / + + + align:start position:0% +difference in time u j n + 1 - UJ n -1 / +2 Delta + + align:start position:0% +2 Delta + + + align:start position:0% +2 Delta +T's = C * a center difference in space u + + align:start position:0% +T's = C * a center difference in space u + + + align:start position:0% +T's = C * a center difference in space u +j + 1 nus u j -1 n over 2 Delta + + align:start position:0% +j + 1 nus u j -1 n over 2 Delta + + + align:start position:0% +j + 1 nus u j -1 n over 2 Delta +X so you see right away the twos + + align:start position:0% +X so you see right away the twos + + + align:start position:0% +X so you see right away the twos +cancel that Delta x * C delta T * C over + + align:start position:0% +cancel that Delta x * C delta T * C over + + + align:start position:0% +cancel that Delta x * C delta T * C over +Delta X is our old ratio R so this is + + align:start position:0% +Delta X is our old ratio R so this is + + + align:start position:0% +Delta X is our old ratio R so this is +this is easily easily written in terms + + align:start position:0% +this is easily easily written in terms + + + align:start position:0% +this is easily easily written in terms +of R again it does have this two + + align:start position:0% +of R again it does have this two + + + align:start position:0% +of R again it does have this two +EP uh + + align:start position:0% +EP uh + + + align:start position:0% +EP uh +issue uh and of course it has we have to + + align:start position:0% +issue uh and of course it has we have to + + + align:start position:0% +issue uh and of course it has we have to +think about stability I'm writing down a + + align:start position:0% +think about stability I'm writing down a + + + align:start position:0% +think about stability I'm writing down a +a a fourth candidate for the equation + + align:start position:0% +a a fourth candidate for the equation + + + align:start position:0% +a a fourth candidate for the equation +utal CX of + + align:start position:0% +utal CX of + + + align:start position:0% +utal CX of +course before I come back to the second + + align:start position:0% +course before I come back to the second + + + align:start position:0% +course before I come back to the second +order equations or systems let's I just + + align:start position:0% +order equations or systems let's I just + + + align:start position:0% +order equations or systems let's I just +wanted to put in these comments partly + + align:start position:0% +wanted to put in these comments partly + + + align:start position:0% +wanted to put in these comments partly +because I'm thinking about uh projects + + align:start position:0% +because I'm thinking about uh projects + + + align:start position:0% +because I'm thinking about uh projects +that are that and I hope you are that + + align:start position:0% +that are that and I hope you are that + + + align:start position:0% +that are that and I hope you are that +uh so some people will have uh like + + align:start position:0% +uh so some people will have uh like + + + align:start position:0% +uh so some people will have uh like +feces or or uh problems from other + + align:start position:0% +feces or or uh problems from other + + + align:start position:0% +feces or or uh problems from other +courses which involve solving pdes and + + align:start position:0% +courses which involve solving pdes and + + + align:start position:0% +courses which involve solving pdes and +that'd be perfect natural to to + + align:start position:0% +that'd be perfect natural to to + + + align:start position:0% +that'd be perfect natural to to +uh to uh base a project on uh but if you + + align:start position:0% +uh to uh base a project on uh but if you + + + align:start position:0% +uh to uh base a project on uh but if you +don't have some specific application + + align:start position:0% +don't have some specific application + + + align:start position:0% +don't have some specific application +then uh here are a whole lot of + + align:start position:0% +then uh here are a whole lot of + + + align:start position:0% +then uh here are a whole lot of +interesting questions uh to just go + + align:start position:0% +interesting questions uh to just go + + + align:start position:0% +interesting questions uh to just go +further with that so the the dependence + + align:start position:0% +further with that so the the dependence + + + align:start position:0% +further with that so the the dependence +on R would be + + align:start position:0% + + + + align:start position:0% + +a depend the + + align:start position:0% +a depend the + + + align:start position:0% +a depend the +profile the the + + align:start position:0% +profile the the + + + align:start position:0% +profile the the +profile + + align:start position:0% +profile + + + align:start position:0% +profile +dependence on + + align:start position:0% +dependence on + + + align:start position:0% +dependence on +r c delta T over Delta X would be a + + align:start position:0% +r c delta T over Delta X would be a + + + align:start position:0% +r c delta T over Delta X would be a +question and + + align:start position:0% +question and + + + align:start position:0% +question and +uh let me just emphasize what what's the + + align:start position:0% +uh let me just emphasize what what's the + + + align:start position:0% +uh let me just emphasize what what's the +goal when I say that this upwind one is + + align:start position:0% +goal when I say that this upwind one is + + + align:start position:0% +goal when I say that this upwind one is +smeared out I mean that it doesn't + + align:start position:0% +smeared out I mean that it doesn't + + + align:start position:0% +smeared out I mean that it doesn't +satisfy what you really hope for you you + + align:start position:0% +satisfy what you really hope for you you + + + align:start position:0% +satisfy what you really hope for you you +want to capture that shock that + + align:start position:0% +want to capture that shock that + + + align:start position:0% +want to capture that shock that +discontinuity well not perfectly you + + align:start position:0% +discontinuity well not perfectly you + + + align:start position:0% +discontinuity well not perfectly you +can't expect that but you want to + + align:start position:0% +can't expect that but you want to + + + align:start position:0% +can't expect that but you want to +capture it maybe in let's say 2 Delta x + + align:start position:0% +capture it maybe in let's say 2 Delta x + + + align:start position:0% +capture it maybe in let's say 2 Delta x +a good method captures the shock within + + align:start position:0% +a good method captures the shock within + + + align:start position:0% +a good method captures the shock within +2 Delta X and does it + + align:start position:0% +2 Delta X and does it + + + align:start position:0% +2 Delta X and does it +without much uh undesirable oscillation + + align:start position:0% +without much uh undesirable oscillation + + + align:start position:0% +without much uh undesirable oscillation +unphysical oscillation like that so + + align:start position:0% +unphysical oscillation like that so + + + align:start position:0% +unphysical oscillation like that so +these are methods where we we're trading + + align:start position:0% +these are methods where we we're trading + + + align:start position:0% +these are methods where we we're trading +off a good shock capture + + align:start position:0% +off a good shock capture + + + align:start position:0% +off a good shock capture +versus a smeared one which is not + + align:start position:0% +versus a smeared one which is not + + + align:start position:0% +versus a smeared one which is not +satisfactory really uh in in a lot of + + align:start position:0% +satisfactory really uh in in a lot of + + + align:start position:0% +satisfactory really uh in in a lot of +applications so capturing the shock + + align:start position:0% +applications so capturing the shock + + + align:start position:0% +applications so capturing the shock +within uh two Delta X roughly is uh + + align:start position:0% +within uh two Delta X roughly is uh + + + align:start position:0% +within uh two Delta X roughly is uh +highly desirable and and + + align:start position:0% +highly desirable and and + + + align:start position:0% +highly desirable and and +uh you might have to go to add a + + align:start position:0% +uh you might have to go to add a + + + align:start position:0% +uh you might have to go to add a +artificial viscosity that we'll discuss + + align:start position:0% +artificial viscosity that we'll discuss + + + align:start position:0% +artificial viscosity that we'll discuss +uh to get there okay so that's past + + align:start position:0% +uh to get there okay so that's past + + + align:start position:0% +uh to get there okay so that's past +things but still very much present if I + + align:start position:0% +things but still very much present if I + + + align:start position:0% +things but still very much present if I +can say and and here I've introduced a + + align:start position:0% +can say and and here I've introduced a + + + align:start position:0% +can say and and here I've introduced a +new a new Leap Frog a oneway oneway + + align:start position:0% +new a new Leap Frog a oneway oneway + + + align:start position:0% +new a new Leap Frog a oneway oneway +equation Leap Frog I I'll call + + align:start position:0% +equation Leap Frog I I'll call + + + align:start position:0% +equation Leap Frog I I'll call +this + + align:start position:0% + + + + align:start position:0% + +where the last lecture was about two-way + + align:start position:0% +where the last lecture was about two-way + + + align:start position:0% +where the last lecture was about two-way +Leap Frog Leap Frog for uttal c^2 uxx a + + align:start position:0% +Leap Frog Leap Frog for uttal c^2 uxx a + + + align:start position:0% +Leap Frog Leap Frog for uttal c^2 uxx a +two-way wave equation I I might just + + align:start position:0% +two-way wave equation I I might just + + + align:start position:0% +two-way wave equation I I might just +mentioned about this oneway Leap Frog + + align:start position:0% +mentioned about this oneway Leap Frog + + + align:start position:0% +mentioned about this oneway Leap Frog +once + + align:start position:0% +once + + + align:start position:0% +once +you put in e to the I KX as we always do + + align:start position:0% +you put in e to the I KX as we always do + + + align:start position:0% +you put in e to the I KX as we always do +or e to the + + align:start position:0% +or e to the + + + align:start position:0% +or e to the +i k j Delta X in the discret case so you + + align:start position:0% +i k j Delta X in the discret case so you + + + align:start position:0% +i k j Delta X in the discret case so you +would put in e to the i j j Delta + + align:start position:0% +would put in e to the i j j Delta + + + align:start position:0% +would put in e to the i j j Delta +X time + + align:start position:0% + + + + align:start position:0% + +K and then find the G the growth factor + + align:start position:0% +K and then find the G the growth factor + + + align:start position:0% +K and then find the G the growth factor +in that'll depend on K and will tell us + + align:start position:0% +in that'll depend on K and will tell us + + + align:start position:0% +in that'll depend on K and will tell us +the time dependence it'll be a g to the + + align:start position:0% +the time dependence it'll be a g to the + + + align:start position:0% +the time dependence it'll be a g to the +N + + align:start position:0% +N + + + align:start position:0% +N +uh I think you'll + + align:start position:0% +uh I think you'll + + + align:start position:0% +uh I think you'll +find that for this guy the absolute + + align:start position:0% +find that for this guy the absolute + + + align:start position:0% +find that for this guy the absolute +value of G is exactly one while it's + + align:start position:0% +value of G is exactly one while it's + + + align:start position:0% +value of G is exactly one while it's +stable of course if the crun condition + + align:start position:0% +stable of course if the crun condition + + + align:start position:0% +stable of course if the crun condition +is violated then there's no way it could + + align:start position:0% +is violated then there's no way it could + + + align:start position:0% +is violated then there's no way it could +be stable and G's will grow be bigger + + align:start position:0% +be stable and G's will grow be bigger + + + align:start position:0% +be stable and G's will grow be bigger +than one + + align:start position:0% +than one + + + align:start position:0% +than one +but I think in the stable + + align:start position:0% +but I think in the stable + + + align:start position:0% +but I think in the stable +range you will have this G will have + + align:start position:0% +range you will have this G will have + + + align:start position:0% +range you will have this G will have +absolute value exactly + + align:start position:0% +absolute value exactly + + + align:start position:0% +absolute value exactly +one H and uh so it'll be on the unit + + align:start position:0% +one H and uh so it'll be on the unit + + + align:start position:0% +one H and uh so it'll be on the unit +circle and you don't have much leeway + + align:start position:0% +circle and you don't have much leeway + + + align:start position:0% +circle and you don't have much leeway +right we we found upwind was like well + + align:start position:0% +right we we found upwind was like well + + + align:start position:0% +right we we found upwind was like well +inside LAX friedricks was well inside + + align:start position:0% +inside LAX friedricks was well inside + + + align:start position:0% +inside LAX friedricks was well inside +LAX wend because it had higher accuracy + + align:start position:0% +LAX wend because it had higher accuracy + + + align:start position:0% +LAX wend because it had higher accuracy +near near for low + + align:start position:0% +near near for low + + + align:start position:0% +near near for low +frequencies was closer and I think this + + align:start position:0% +frequencies was closer and I think this + + + align:start position:0% +frequencies was closer and I think this +guy is right + + align:start position:0% +guy is right + + + align:start position:0% +guy is right +on so this is this is the first order + + align:start position:0% +on so this is this is the first order + + + align:start position:0% +on so this is this is the first order +methods this is LAX wend and this would + + align:start position:0% +methods this is LAX wend and this would + + + align:start position:0% +methods this is LAX wend and this would +be this second order method and so it's + + align:start position:0% +be this second order method and so it's + + + align:start position:0% +be this second order method and so it's +it's you're really playing with fire + + align:start position:0% +it's you're really playing with fire + + + align:start position:0% +it's you're really playing with fire +there and uh maybe this is not a + + align:start position:0% +there and uh maybe this is not a + + + align:start position:0% +there and uh maybe this is not a +favorite just because it's too close to + + align:start position:0% +favorite just because it's too close to + + + align:start position:0% +favorite just because it's too close to +the edge in fact right on the edge okay + + align:start position:0% +the edge in fact right on the edge okay + + + align:start position:0% +the edge in fact right on the edge okay +so those are some comments really + + align:start position:0% +so those are some comments really + + + align:start position:0% +so those are some comments really +generated by your uh your numerical + + align:start position:0% +generated by your uh your numerical + + + align:start position:0% +generated by your uh your numerical +experiments and and I think that's the + + align:start position:0% +experiments and and I think that's the + + + align:start position:0% +experiments and and I think that's the +way this course should uh homeworks and + + align:start position:0% +way this course should uh homeworks and + + + align:start position:0% +way this course should uh homeworks and +and projects should develop out of + + align:start position:0% +and projects should develop out of + + + align:start position:0% +and projects should develop out of +numerical experiments okay + + align:start position:0% +numerical experiments okay + + + align:start position:0% +numerical experiments okay +now I'll coming back for to complete my + + align:start position:0% +now I'll coming back for to complete my + + + align:start position:0% +now I'll coming back for to complete my +lecture on the second order wave + + align:start position:0% + + + + align:start position:0% + +equation so we + + align:start position:0% +equation so we + + + align:start position:0% +equation so we +studied Leap Frog for + + align:start position:0% +studied Leap Frog for + + + align:start position:0% +studied Leap Frog for +that I won't repeat that but then with + + align:start position:0% +that I won't repeat that but then with + + + align:start position:0% +that I won't repeat that but then with +second order wave equation we have + + align:start position:0% +second order wave equation we have + + + align:start position:0% +second order wave equation we have +another option which is to + + align:start position:0% +another option which is to + + + align:start position:0% +another option which is to +reduce a sec a second order equation in + + align:start position:0% +reduce a sec a second order equation in + + + align:start position:0% +reduce a sec a second order equation in +with with a two time derivatives to a + + align:start position:0% +with with a two time derivatives to a + + + align:start position:0% +with with a two time derivatives to a +system of two equations with that are + + align:start position:0% +system of two equations with that are + + + align:start position:0% +system of two equations with that are +first order in time and + + align:start position:0% +first order in time and + + + align:start position:0% +first order in time and +space and I've chosen to use the letters + + align:start position:0% +space and I've chosen to use the letters + + + align:start position:0% +space and I've chosen to use the letters +H and e as a kind of + + align:start position:0% +H and e as a kind of + + + align:start position:0% +H and e as a kind of +a hint that that we're + + align:start position:0% +a hint that that we're + + + align:start position:0% +a hint that that we're +touching a really big application which + + align:start position:0% +touching a really big application which + + + align:start position:0% +touching a really big application which +is + + align:start position:0% +is + + + align:start position:0% +is +electromagnetism so e for the electric + + align:start position:0% +electromagnetism so e for the electric + + + align:start position:0% +electromagnetism so e for the electric +field H for the magnetic field but here + + align:start position:0% +field H for the magnetic field but here + + + align:start position:0% +field H for the magnetic field but here +in + + align:start position:0% +in + + + align:start position:0% +in +1D + + align:start position:0% +1D + + + align:start position:0% +1D +uh so it allows me just to mention + + align:start position:0% +uh so it allows me just to mention + + + align:start position:0% +uh so it allows me just to mention +that in 3D when e has three components H + + align:start position:0% +that in 3D when e has three components H + + + align:start position:0% +that in 3D when e has three components H +has three components this is really the + + align:start position:0% +has three components this is really the + + + align:start position:0% +has three components this is really the +curl and this is really minus the + + align:start position:0% +curl and this is really minus the + + + align:start position:0% +curl and this is really minus the +curl + + align:start position:0% +curl + + + align:start position:0% +curl +and the notes will show the + + align:start position:0% +and the notes will show the + + + align:start position:0% +and the notes will show the +beautiful + + align:start position:0% +beautiful + + + align:start position:0% +beautiful +uh Ye Ye uh + + align:start position:0% +uh Ye Ye uh + + + align:start position:0% +uh Ye Ye uh +mesh uh staggered mesh that that that + + align:start position:0% +mesh uh staggered mesh that that that + + + align:start position:0% +mesh uh staggered mesh that that that +copies for finite difference methods the + + align:start position:0% +copies for finite difference methods the + + + align:start position:0% +copies for finite difference methods the +uh uh the properties of the + + align:start position:0% + + + + align:start position:0% + +curl our our our interpretation of and + + align:start position:0% +curl our our our interpretation of and + + + align:start position:0% +curl our our our interpretation of and +the the properties of that Maxwell + + align:start position:0% +the the properties of that Maxwell + + + align:start position:0% +the the properties of that Maxwell +discovered the physics of you know + + align:start position:0% +discovered the physics of you know + + + align:start position:0% +discovered the physics of you know +current magnetic fields going around uh + + align:start position:0% +current magnetic fields going around uh + + + align:start position:0% +current magnetic fields going around uh +uh a wire that along which an electric + + align:start position:0% +uh a wire that along which an electric + + + align:start position:0% +uh a wire that along which an electric +field is going + + align:start position:0% +field is going + + + align:start position:0% +field is going +okay but I let me stay here with one + + align:start position:0% +okay but I let me stay here with one + + + align:start position:0% +okay but I let me stay here with one +dimension so first of all can we recover + + align:start position:0% +dimension so first of all can we recover + + + align:start position:0% +dimension so first of all can we recover +the wave equation from that let's just + + align:start position:0% +the wave equation from that let's just + + + align:start position:0% +the wave equation from that let's just +see that we haven't left behind the wave + + align:start position:0% + + + + align:start position:0% + +equation okay so uh I just take the + + align:start position:0% +equation okay so uh I just take the + + + align:start position:0% +equation okay so uh I just take the +second derivative so the second + + align:start position:0% +second derivative so the second + + + align:start position:0% +second derivative so the second +derivative I I just want to recover the + + align:start position:0% +derivative I I just want to recover the + + + align:start position:0% +derivative I I just want to recover the +wave equation show that I haven't lost + + align:start position:0% +wave equation show that I haven't lost + + + align:start position:0% +wave equation show that I haven't lost +it here so this will be if I I'm taking + + align:start position:0% +it here so this will be if I I'm taking + + + align:start position:0% +it here so this will be if I I'm taking +the time derivative of the first first + + align:start position:0% +the time derivative of the first first + + + align:start position:0% +the time derivative of the first first +equation so I + + align:start position:0% +equation so I + + + align:start position:0% +equation so I +get DC H dtdx + + align:start position:0% +get DC H dtdx + + + align:start position:0% +get DC H dtdx +right but by the + + align:start position:0% +right but by the + + + align:start position:0% +right but by the +useful extremely useful fact that this + + align:start position:0% +useful extremely useful fact that this + + + align:start position:0% +useful extremely useful fact that this +is the same as taking the T derivative + + align:start position:0% +is the same as taking the T derivative + + + align:start position:0% +is the same as taking the T derivative +first and the X derivative + + align:start position:0% +first and the X derivative + + + align:start position:0% +first and the X derivative +second now I have the X derivative of + + align:start position:0% +second now I have the X derivative of + + + align:start position:0% +second now I have the X derivative of +this equation so this is + + align:start position:0% +this equation so this is + + + align:start position:0% +this equation so this is +C now I have the X + + align:start position:0% +C now I have the X + + + align:start position:0% +C now I have the X +derivative or c times it so now I'm up + + align:start position:0% +derivative or c times it so now I'm up + + + align:start position:0% +derivative or c times it so now I'm up +to c^2 the X derivative of the X + + align:start position:0% +to c^2 the X derivative of the X + + + align:start position:0% +to c^2 the X derivative of the X +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +right okay so we eliminated + + align:start position:0% +right okay so we eliminated + + + align:start position:0% +right okay so we eliminated +H got back to one equation second order + + align:start position:0% +H got back to one equation second order + + + align:start position:0% +H got back to one equation second order +and it's the wave + + align:start position:0% +and it's the wave + + + align:start position:0% +and it's the wave +equation okay I I I want to show the + + align:start position:0% +equation okay I I I want to show the + + + align:start position:0% +equation okay I I I want to show the +same thing now for finite differences + + align:start position:0% +same thing now for finite differences + + + align:start position:0% +same thing now for finite differences +it's just it's it's such a simple and + + align:start position:0% +it's just it's it's such a simple and + + + align:start position:0% +it's just it's it's such a simple and +useful + + align:start position:0% +useful + + + align:start position:0% +useful +device and our point will be that it + + align:start position:0% +device and our point will be that it + + + align:start position:0% +device and our point will be that it +works for just as well for differences + + align:start position:0% +works for just as well for differences + + + align:start position:0% +works for just as well for differences +and that allows us to do this staggered + + align:start position:0% +and that allows us to do this staggered + + + align:start position:0% +and that allows us to do this staggered +grid idea so so the staggered grid idea + + align:start position:0% +grid idea so so the staggered grid idea + + + align:start position:0% +grid idea so so the staggered grid idea +is I'll do + + align:start position:0% +is I'll do + + + align:start position:0% +is I'll do +e on this Grid at these grid points H at + + align:start position:0% +e on this Grid at these grid points H at + + + align:start position:0% +e on this Grid at these grid points H at +the half points e again at the integer + + align:start position:0% +the half points e again at the integer + + + align:start position:0% +the half points e again at the integer +point points H again at the half points + + align:start position:0% +point points H again at the half points + + + align:start position:0% +point points H again at the half points +and now so my my + + align:start position:0% +and now so my my + + + align:start position:0% +and now so my my +U difference method Leap Frog on the + + align:start position:0% +U difference method Leap Frog on the + + + align:start position:0% +U difference method Leap Frog on the +staggered mesh will copy so so the first + + align:start position:0% +staggered mesh will copy so so the first + + + align:start position:0% +staggered mesh will copy so so the first +equation will give e at the new + + align:start position:0% +equation will give e at the new + + + align:start position:0% +equation will give e at the new +time from the difference in h at this + + align:start position:0% +time from the difference in h at this + + + align:start position:0% +time from the difference in h at this +time + + align:start position:0% +time + + + align:start position:0% +time +and so you see you see it D DT is going + + align:start position:0% +and so you see you see it D DT is going + + + align:start position:0% +and so you see you see it D DT is going +to be replaced + + align:start position:0% +to be replaced + + + align:start position:0% +to be replaced +by that that time difference dhdx is + + align:start position:0% +by that that time difference dhdx is + + + align:start position:0% +by that that time difference dhdx is +going to be replaced by this space + + align:start position:0% +going to be replaced by this space + + + align:start position:0% +going to be replaced by this space +difference and that will determine e at + + align:start position:0% +difference and that will determine e at + + + align:start position:0% +difference and that will determine e at +the new time so I need I need time zero + + align:start position:0% +the new time so I need I need time zero + + + align:start position:0% +the new time so I need I need time zero +and time 1/2 to get started maybe I put + + align:start position:0% +and time 1/2 to get started maybe I put + + + align:start position:0% +and time 1/2 to get started maybe I put +those down here somewhere I have to use + + align:start position:0% +those down here somewhere I have to use + + + align:start position:0% +those down here somewhere I have to use +the initial condition the initial + + align:start position:0% +the initial condition the initial + + + align:start position:0% +the initial condition the initial +velocity to get + + align:start position:0% +velocity to get + + + align:start position:0% +velocity to get +started on E and H and then I go onwards + + align:start position:0% +started on E and H and then I go onwards + + + align:start position:0% +started on E and H and then I go onwards +I've got to this point and this point + + align:start position:0% +I've got to this point and this point + + + align:start position:0% +I've got to this point and this point +then this guy comes from this one this + + align:start position:0% +then this guy comes from this one this + + + align:start position:0% +then this guy comes from this one this +one and this + + align:start position:0% + + + + align:start position:0% + +one and of course that similarly comes + + align:start position:0% +one and of course that similarly comes + + + align:start position:0% +one and of course that similarly comes +from the same equation shifted over and + + align:start position:0% +from the same equation shifted over and + + + align:start position:0% +from the same equation shifted over and +then now I know these now I'm ready for + + align:start position:0% +then now I know these now I'm ready for + + + align:start position:0% +then now I know these now I'm ready for +this one + + align:start position:0% +this one + + + align:start position:0% +this one +coming from now I'm what am I + + align:start position:0% +coming from now I'm what am I + + + align:start position:0% +coming from now I'm what am I +approximating now I'm on the the + + align:start position:0% +approximating now I'm on the the + + + align:start position:0% +approximating now I'm on the the +staggered part of the grid the the half + + align:start position:0% +staggered part of the grid the the half + + + align:start position:0% +staggered part of the grid the the half +steps I'm approximating this on the half + + align:start position:0% +steps I'm approximating this on the half + + + align:start position:0% +steps I'm approximating this on the half +steps where H is defined so that minus + + align:start position:0% +steps where H is defined so that minus + + + align:start position:0% +steps where H is defined so that minus +that is the time + + align:start position:0% +that is the time + + + align:start position:0% +that is the time +difference this minus this which I know + + align:start position:0% +difference this minus this which I know + + + align:start position:0% +difference this minus this which I know +these now is the space difference in + + align:start position:0% +these now is the space difference in + + + align:start position:0% +these now is the space difference in +this equation and that's what allows me + + align:start position:0% +this equation and that's what allows me + + + align:start position:0% +this equation and that's what allows me +to compute the new one you you see it's + + align:start position:0% +to compute the new one you you see it's + + + align:start position:0% +to compute the new one you you see it's +a simple + + align:start position:0% +a simple + + + align:start position:0% +a simple +idea it's very it's it's close but + + align:start position:0% +idea it's very it's it's close but + + + align:start position:0% +idea it's very it's it's close but +different from + + align:start position:0% +different from + + + align:start position:0% +different from +my uh from my uh scaler Leap Frog oneway + + align:start position:0% +my uh from my uh scaler Leap Frog oneway + + + align:start position:0% +my uh from my uh scaler Leap Frog oneway +Leap Frog here here it was the same U at + + align:start position:0% +Leap Frog here here it was the same U at + + + align:start position:0% +Leap Frog here here it was the same U at +all the points here it is e at the + + align:start position:0% +all the points here it is e at the + + + align:start position:0% +all the points here it is e at the +integer time time levels and H at the + + align:start position:0% +integer time time levels and H at the + + + align:start position:0% +integer time time levels and H at the +half integer time levels and and uh oh + + align:start position:0% +half integer time levels and and uh oh + + + align:start position:0% +half integer time levels and and uh oh +well it's natural to + + align:start position:0% +well it's natural to + + + align:start position:0% +well it's natural to +say I'm calling this Leap Frog could + + align:start position:0% +say I'm calling this Leap Frog could + + + align:start position:0% +say I'm calling this Leap Frog could +I could I do + + align:start position:0% +I could I do + + + align:start position:0% +I could I do +this for the difference + + align:start position:0% +this for the difference + + + align:start position:0% +this for the difference +equation I just want to see that if I + + align:start position:0% +equation I just want to see that if I + + + align:start position:0% +equation I just want to see that if I +eliminate H so you saw what happened + + align:start position:0% +eliminate H so you saw what happened + + + align:start position:0% +eliminate H so you saw what happened +there by using the identity that the + + align:start position:0% +there by using the identity that the + + + align:start position:0% +there by using the identity that the +second derivative in T and X is always + + align:start position:0% +second derivative in T and X is always + + + align:start position:0% +second derivative in T and X is always +the same as the second derivative in x + + align:start position:0% +the same as the second derivative in x + + + align:start position:0% +the same as the second derivative in x +and t I eliminated H and got an equation + + align:start position:0% +and t I eliminated H and got an equation + + + align:start position:0% +and t I eliminated H and got an equation +that involved e + + align:start position:0% + + + + align:start position:0% + +only well what's going to be + + align:start position:0% +only well what's going to be + + + align:start position:0% +only well what's going to be +the + + align:start position:0% + + + + align:start position:0% + +corresponding identity trivial but just + + align:start position:0% +corresponding identity trivial but just + + + align:start position:0% +corresponding identity trivial but just +trivial things are not bad things to + + align:start position:0% +trivial things are not bad things to + + + align:start position:0% +trivial things are not bad things to +notice uh for the difference + + align:start position:0% +notice uh for the difference + + + align:start position:0% +notice uh for the difference +method well here this is what I wanted + + align:start position:0% +method well here this is what I wanted + + + align:start position:0% +method well here this is what I wanted +to be sure of for for the h part this H + + align:start position:0% +to be sure of for for the h part this H + + + align:start position:0% +to be sure of for for the h part this H +and so the H were were now do you mind + + align:start position:0% +and so the H were were now do you mind + + + align:start position:0% +and so the H were were now do you mind +if I draw yet another symbol I I want to + + align:start position:0% +if I draw yet another symbol I I want to + + + align:start position:0% +if I draw yet another symbol I I want to +use this + + align:start position:0% +use this + + + align:start position:0% +use this +idea to eliminate H so let me put two h + + align:start position:0% +idea to eliminate H so let me put two h + + + align:start position:0% +idea to eliminate H so let me put two h +two h's there uh is that right yeah I I + + align:start position:0% +two h's there uh is that right yeah I I + + + align:start position:0% +two h's there uh is that right yeah I I +I think what I'd like to + + align:start position:0% +I think what I'd like to + + + align:start position:0% +I think what I'd like to +know well let me just say what what I + + align:start position:0% +know well let me just say what what I + + + align:start position:0% +know well let me just say what what I +believe I believe that + + align:start position:0% +believe I believe that + + + align:start position:0% +believe I believe that +the that the time difference of the + + align:start position:0% +the that the time difference of the + + + align:start position:0% +the that the time difference of the +space difference of H at mesh points is + + align:start position:0% +space difference of H at mesh points is + + + align:start position:0% +space difference of H at mesh points is +equal to the space difference of the + + align:start position:0% +equal to the space difference of the + + + align:start position:0% +equal to the space difference of the +time + + align:start position:0% +time + + + align:start position:0% +time +difference of H at the same mesh points + + align:start position:0% +difference of H at the same mesh points + + + align:start position:0% +difference of H at the same mesh points +I meant to put these as subscripts + + align:start position:0% +I meant to put these as subscripts + + + align:start position:0% +I meant to put these as subscripts +that's not + + align:start position:0% +that's not + + + align:start position:0% +that's not +Delta it's not Delta X it's + + align:start position:0% +Delta it's not Delta X it's + + + align:start position:0% +Delta it's not Delta X it's +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +subx difference in the time Direction + + align:start position:0% +subx difference in the time Direction + + + align:start position:0% +subx difference in the time Direction +difference in the space Direction let's + + align:start position:0% +difference in the space Direction let's + + + align:start position:0% +difference in the space Direction let's +just see what this means I have let me + + align:start position:0% +just see what this means I have let me + + + align:start position:0% +just see what this means I have let me +let me redraw these four points these + + align:start position:0% +let me redraw these four points these + + + align:start position:0% +let me redraw these four points these +are h h h at all those + + align:start position:0% +are h h h at all those + + + align:start position:0% +are h h h at all those +points so this + + align:start position:0% +points so this + + + align:start position:0% +points so this +says figure out the space differences so + + align:start position:0% +says figure out the space differences so + + + align:start position:0% +says figure out the space differences so +this this minus this and this minus + + align:start position:0% +this this minus this and this minus + + + align:start position:0% +this this minus this and this minus +this and then take the time difference + + align:start position:0% +this and then take the time difference + + + align:start position:0% +this and then take the time difference +of + + align:start position:0% +of + + + align:start position:0% +of +those can I see what I'll get if I do + + align:start position:0% +those can I see what I'll get if I do + + + align:start position:0% +those can I see what I'll get if I do +that so this means I take the space + + align:start position:0% +that so this means I take the space + + + align:start position:0% +that so this means I take the space +differences so I have 1 minus one and + + align:start position:0% +differences so I have 1 minus one and + + + align:start position:0% +differences so I have 1 minus one and +that would be 1 - one but now I'm going + + align:start position:0% +that would be 1 - one but now I'm going + + + align:start position:0% +that would be 1 - one but now I'm going +to take the time difference of those so + + align:start position:0% +to take the time difference of those so + + + align:start position:0% +to take the time difference of those so +that'll be this one minus this one and + + align:start position:0% +that'll be this one minus this one and + + + align:start position:0% +that'll be this one minus this one and +this one plus this + + align:start position:0% +this one plus this + + + align:start position:0% +this one plus this +one do you see + + align:start position:0% +one do you see + + + align:start position:0% +one do you see +that what we have here + + align:start position:0% + + + + align:start position:0% + +is H at this point minus H at this point + + align:start position:0% +is H at this point minus H at this point + + + align:start position:0% +is H at this point minus H at this point +minus H at this point plus h at this + + align:start position:0% +minus H at this point plus h at this + + + align:start position:0% +minus H at this point plus h at this +point plus + + align:start position:0% +point plus + + + align:start position:0% +point plus +one and I claim that we have the same + + align:start position:0% +one and I claim that we have the same + + + align:start position:0% +one and I claim that we have the same +thing here that if I take the time + + align:start position:0% +thing here that if I take the time + + + align:start position:0% +thing here that if I take the time +differences first can I do that let me + + align:start position:0% +differences first can I do that let me + + + align:start position:0% +differences first can I do that let me +instead of taking the space differences + + align:start position:0% +instead of taking the space differences + + + align:start position:0% +instead of taking the space differences +first I'll take this one this this time + + align:start position:0% +first I'll take this one this this time + + + align:start position:0% +first I'll take this one this this time +difference this minus + + align:start position:0% +difference this minus + + + align:start position:0% +difference this minus +this and I'll subtract I'm taking now + + align:start position:0% +this and I'll subtract I'm taking now + + + align:start position:0% +this and I'll subtract I'm taking now +the space difference I'll subtract + + align:start position:0% +the space difference I'll subtract + + + align:start position:0% +the space difference I'll subtract +are you with + + align:start position:0% +are you with + + + align:start position:0% +are you with +me you see it's just the same + + align:start position:0% +me you see it's just the same + + + align:start position:0% +me you see it's just the same +four values two ones and two minus + + align:start position:0% +four values two ones and two minus + + + align:start position:0% +four values two ones and two minus +ones whether we go first in fact th this + + align:start position:0% +ones whether we go first in fact th this + + + align:start position:0% +ones whether we go first in fact th this +actually is a I think maybe throws a + + align:start position:0% +actually is a I think maybe throws a + + + align:start position:0% +actually is a I think maybe throws a +little light on the on the calculus uh + + align:start position:0% +little light on the on the calculus uh + + + align:start position:0% +little light on the on the calculus uh +identity that that that we + + align:start position:0% +identity that that that we + + + align:start position:0% +identity that that that we +can we can uh exchange the order of the + + align:start position:0% +can we can uh exchange the order of the + + + align:start position:0% +can we can uh exchange the order of the +derivatives + + align:start position:0% +derivatives + + + align:start position:0% +derivatives +because we know we can exchange the + + align:start position:0% +because we know we can exchange the + + + align:start position:0% +because we know we can exchange the +order of the differences because we've + + align:start position:0% +order of the differences because we've + + + align:start position:0% +order of the differences because we've +just got numbers like 1 minus one minus + + align:start position:0% +just got numbers like 1 minus one minus + + + align:start position:0% +just got numbers like 1 minus one minus +one and plus + + align:start position:0% +one and plus + + + align:start position:0% +one and plus +one + + align:start position:0% +one + + + align:start position:0% +one +okay so and if we let the + + align:start position:0% +okay so and if we let the + + + align:start position:0% +okay so and if we let the +spacing the mesh go to zero this I and + + align:start position:0% +spacing the mesh go to zero this I and + + + align:start position:0% +spacing the mesh go to zero this I and +divided by the Delta X and the delta T + + align:start position:0% +divided by the Delta X and the delta T + + + align:start position:0% +divided by the Delta X and the delta T +uh I I suppose we would prove the the uh + + align:start position:0% +uh I I suppose we would prove the the uh + + + align:start position:0% +uh I I suppose we would prove the the uh +continuous case so in a way this throws + + align:start position:0% +continuous case so in a way this throws + + + align:start position:0% +continuous case so in a way this throws +light on something that's probably + + align:start position:0% +light on something that's probably + + + align:start position:0% +light on something that's probably +something that we take for granted but + + align:start position:0% +something that we take for granted but + + + align:start position:0% +something that we take for granted but +we wouldn't want to be uh pressed on too + + align:start position:0% +we wouldn't want to be uh pressed on too + + + align:start position:0% +we wouldn't want to be uh pressed on too +closely okay + + align:start position:0% +closely okay + + + align:start position:0% +closely okay +so so having that + + align:start position:0% + + + + align:start position:0% + +identity allows me to do exactly what I + + align:start position:0% +identity allows me to do exactly what I + + + align:start position:0% +identity allows me to do exactly what I +did with the continuous case there and + + align:start position:0% +did with the continuous case there and + + + align:start position:0% +did with the continuous case there and +show that + + align:start position:0% +show that + + + align:start position:0% +show that +this when I eliminate the half + + align:start position:0% +this when I eliminate the half + + + align:start position:0% +this when I eliminate the half +levels I've + + align:start position:0% +levels I've + + + align:start position:0% +levels I've +got ordinary Lea + + align:start position:0% +got ordinary Lea + + + align:start position:0% +got ordinary Lea +frog so when I eliminate half levels I + + align:start position:0% +frog so when I eliminate half levels I + + + align:start position:0% +frog so when I eliminate half levels I +will be when I eliminate this half level + + align:start position:0% +will be when I eliminate this half level + + + align:start position:0% +will be when I eliminate this half level +let's say then I'll be connecting well + + align:start position:0% +let's say then I'll be connecting well + + + align:start position:0% +let's say then I'll be connecting well +yep when I eliminate half levels I'm + + align:start position:0% +yep when I eliminate half levels I'm + + + align:start position:0% +yep when I eliminate half levels I'm +going to be connecting these at three + + align:start position:0% +going to be connecting these at three + + + align:start position:0% +going to be connecting these at three +levels one two three and the and the + + align:start position:0% +levels one two three and the and the + + + align:start position:0% +levels one two three and the and the +second different it'll be it'll be Lea + + align:start position:0% +second different it'll be it'll be Lea + + + align:start position:0% +second different it'll be it'll be Lea +frog it'll be so since it's been + + align:start position:0% +frog it'll be so since it's been + + + align:start position:0% +frog it'll be so since it's been +uh a few days since uh we wrote down + + align:start position:0% +uh a few days since uh we wrote down + + + align:start position:0% +uh a few days since uh we wrote down +two-way Leap + + align:start position:0% +two-way Leap + + + align:start position:0% +two-way Leap +Frog or second order equation Leap Frog + + align:start position:0% +Frog or second order equation Leap Frog + + + align:start position:0% +Frog or second order equation Leap Frog +let me just write it again and that's + + align:start position:0% +let me just write it again and that's + + + align:start position:0% +let me just write it again and that's +what we would get the time difference + + align:start position:0% +what we would get the time difference + + + align:start position:0% +what we would get the time difference +squared of + + align:start position:0% + + + + align:start position:0% + +e is equal will be equal to c^ 2 time + + align:start position:0% +e is equal will be equal to c^ 2 time + + + align:start position:0% +e is equal will be equal to c^ 2 time +the space difference squar of e and of + + align:start position:0% +the space difference squar of e and of + + + align:start position:0% +the space difference squar of e and of +course here we have a Delta X squar and + + align:start position:0% +course here we have a Delta X squar and + + + align:start position:0% +course here we have a Delta X squar and +here a Delta + + align:start position:0% +here a Delta + + + align:start position:0% +here a Delta +t^2 so allog together an r s that's the + + align:start position:0% +t^2 so allog together an r s that's the + + + align:start position:0% +t^2 so allog together an r s that's the +that's the formula we know that's the + + align:start position:0% +that's the formula we know that's the + + + align:start position:0% +that's the formula we know that's the +formula we + + align:start position:0% +formula we + + + align:start position:0% +formula we +know + + align:start position:0% +know + + + align:start position:0% +know +okay so if I simplify this to make it + + align:start position:0% +okay so if I simplify this to make it + + + align:start position:0% +okay so if I simplify this to make it +look + + align:start position:0% +look + + + align:start position:0% +look +good uh put the Delta t^ squ up there + + align:start position:0% +good uh put the Delta t^ squ up there + + + align:start position:0% +good uh put the Delta t^ squ up there +you see that it's just R + + align:start position:0% + + + + align:start position:0% + +SAR and maybe it's worth realizing that + + align:start position:0% +SAR and maybe it's worth realizing that + + + align:start position:0% +SAR and maybe it's worth realizing that +again the magic r equal one the magic so + + align:start position:0% +again the magic r equal one the magic so + + + align:start position:0% +again the magic r equal one the magic so +I'll the magic + + align:start position:0% +I'll the magic + + + align:start position:0% +I'll the magic +ratio r equal 1 gives the + + align:start position:0% + + + + align:start position:0% + +exact you agreeing exactly with you yeah + + align:start position:0% +exact you agreeing exactly with you yeah + + + align:start position:0% +exact you agreeing exactly with you yeah +yeah this equation if R is one would be + + align:start position:0% +yeah this equation if R is one would be + + + align:start position:0% +yeah this equation if R is one would be +satisfied exactly by + + align:start position:0% +satisfied exactly by + + + align:start position:0% +satisfied exactly by +The Continuous solution and so it's the + + align:start position:0% +The Continuous solution and so it's the + + + align:start position:0% +The Continuous solution and so it's the +same as this + + align:start position:0% +same as this + + + align:start position:0% +same as this +one + + align:start position:0% +one + + + align:start position:0% +one +okay so that's uh that's Leap Frog so so + + align:start position:0% +okay so that's uh that's Leap Frog so so + + + align:start position:0% +okay so that's uh that's Leap Frog so so +can I summarize Leap Frog Leap Frog was + + align:start position:0% +can I summarize Leap Frog Leap Frog was + + + align:start position:0% +can I summarize Leap Frog Leap Frog was +first of all that led us to these it it + + align:start position:0% +first of all that led us to these it it + + + align:start position:0% +first of all that led us to these it it +worked for second order + + align:start position:0% +worked for second order + + + align:start position:0% +worked for second order +equations it led us to the same + + align:start position:0% +equations it led us to the same + + + align:start position:0% +equations it led us to the same +stability + + align:start position:0% +stability + + + align:start position:0% +stability +condition that R had to be less or equal + + align:start position:0% +condition that R had to be less or equal + + + align:start position:0% +condition that R had to be less or equal +one but it + + align:start position:0% +one but it + + + align:start position:0% +one but it +took uh + + align:start position:0% +took uh + + + align:start position:0% +took uh +took uh um a quadratic + + align:start position:0% + + + + align:start position:0% + +equation for G remember we had g^ 2 + + align:start position:0% +equation for G remember we had g^ 2 + + + align:start position:0% +equation for G remember we had g^ 2 +minus 2 G * some quantity a that + + align:start position:0% +minus 2 G * some quantity a that + + + align:start position:0% +minus 2 G * some quantity a that +involved RS and cosiness plus 1 equals z + + align:start position:0% +involved RS and cosiness plus 1 equals z + + + align:start position:0% +involved RS and cosiness plus 1 equals z +and the reason it was a quadratic was + + align:start position:0% +and the reason it was a quadratic was + + + align:start position:0% +and the reason it was a quadratic was +there were two time steps + + align:start position:0% + + + + align:start position:0% + +involved but we handled that we got we + + align:start position:0% +involved but we handled that we got we + + + align:start position:0% +involved but we handled that we got we +got stability if R was less than or + + align:start position:0% +got stability if R was less than or + + + align:start position:0% +got stability if R was less than or +equal one that led us to a in magnitude + + align:start position:0% +equal one that led us to a in magnitude + + + align:start position:0% +equal one that led us to a in magnitude +less or equal one and that led us to G + + align:start position:0% +less or equal one and that led us to G + + + align:start position:0% +less or equal one and that led us to G +we + + align:start position:0% +we + + + align:start position:0% +we +I'll just remember those steps a less or + + align:start position:0% +I'll just remember those steps a less or + + + align:start position:0% +I'll just remember those steps a less or +equal 1 and that led us to G less or + + align:start position:0% +equal 1 and that led us to G less or + + + align:start position:0% +equal 1 and that led us to G less or +equal 1 + + align:start position:0% +equal 1 + + + align:start position:0% +equal 1 +okay yeah the the notes + + align:start position:0% +okay yeah the the notes + + + align:start position:0% +okay yeah the the notes +um including + + align:start position:0% +um including + + + align:start position:0% +um including +uh more about Maxwell's equation and + + align:start position:0% +uh more about Maxwell's equation and + + + align:start position:0% +uh more about Maxwell's equation and +ye's beautiful method with a with a + + align:start position:0% +ye's beautiful method with a with a + + + align:start position:0% +ye's beautiful method with a with a +figure that shows his mesh uh will go up + + align:start position:0% +figure that shows his mesh uh will go up + + + align:start position:0% +figure that shows his mesh uh will go up +uh I mean every section is getting uh + + align:start position:0% +uh I mean every section is getting uh + + + align:start position:0% +uh I mean every section is getting uh +upgraded and this one will this is the + + align:start position:0% +upgraded and this one will this is the + + + align:start position:0% +upgraded and this one will this is the +next one to be upgraded probably by + + align:start position:0% +next one to be upgraded probably by + + + align:start position:0% +next one to be upgraded probably by +tomorrow uh you'll have a a good section + + align:start position:0% +tomorrow uh you'll have a a good section + + + align:start position:0% +tomorrow uh you'll have a a good section +on um second order + + align:start position:0% +on um second order + + + align:start position:0% +on um second order +equations anything so that for me + + align:start position:0% + + + + align:start position:0% + +that that's what I wanted to say about + + align:start position:0% +that that's what I wanted to say about + + + align:start position:0% +that that's what I wanted to say about +the wave + + align:start position:0% +the wave + + + align:start position:0% +the wave +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +equation alone + + align:start position:0% +equation alone + + + align:start position:0% +equation alone +with no + + align:start position:0% +with no + + + align:start position:0% +with no +diffusion and now I'm ready to move to + + align:start position:0% +diffusion and now I'm ready to move to + + + align:start position:0% +diffusion and now I'm ready to move to +the heat + + align:start position:0% +the heat + + + align:start position:0% +the heat +equation so what do we have coming up so + + align:start position:0% +equation so what do we have coming up so + + + align:start position:0% +equation so what do we have coming up so +maybe maybe important to say what's + + align:start position:0% +maybe maybe important to say what's + + + align:start position:0% +maybe maybe important to say what's +coming up + + align:start position:0% +coming up + + + align:start position:0% +coming up +the so so we've done oneway + + align:start position:0% + + + + align:start position:0% + +wave now we've done two-way + + align:start position:0% +wave now we've done two-way + + + align:start position:0% +wave now we've done two-way +waves + + align:start position:0% + + + + align:start position:0% + +next comes the heat equation heat + + align:start position:0% + + + + align:start position:0% + +diffusion and then will come a mixture + + align:start position:0% +diffusion and then will come a mixture + + + align:start position:0% +diffusion and then will come a mixture +of the two convection + + align:start position:0% + + + + align:start position:0% + +diffusion and by the way + + align:start position:0% +diffusion and by the way + + + align:start position:0% +diffusion and by the way +uh so I'll + + align:start position:0% +uh so I'll + + + align:start position:0% +uh so I'll +go straight toward to these uh in a + + align:start position:0% +go straight toward to these uh in a + + + align:start position:0% +go straight toward to these uh in a +couple of weeks uh we have our guest + + align:start position:0% +couple of weeks uh we have our guest + + + align:start position:0% +couple of weeks uh we have our guest +lecture who will do the applications to + + align:start position:0% +lecture who will do the applications to + + + align:start position:0% +lecture who will do the applications to +financial + + align:start position:0% +financial + + + align:start position:0% +financial +mathematics mathematical Finance in + + align:start position:0% +mathematics mathematical Finance in + + + align:start position:0% +mathematics mathematical Finance in +specifically the black skulls + + align:start position:0% + + + + align:start position:0% + +equation so you probably know that uh a + + align:start position:0% +equation so you probably know that uh a + + + align:start position:0% +equation so you probably know that uh a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +effort and a lot of money are going + + align:start position:0% +effort and a lot of money are going + + + align:start position:0% +effort and a lot of money are going +into uh the valuation of options and + + align:start position:0% +into uh the valuation of options and + + + align:start position:0% +into uh the valuation of options and +other Financial + + align:start position:0% +other Financial + + + align:start position:0% +other Financial +derivatives and that this equation found + + align:start position:0% +derivatives and that this equation found + + + align:start position:0% +derivatives and that this equation found +this black skull's + + align:start position:0% +this black skull's + + + align:start position:0% +this black skull's +equation beautifully produced the heat + + align:start position:0% +equation beautifully produced the heat + + + align:start position:0% +equation beautifully produced the heat +equation and + + align:start position:0% +equation and + + + align:start position:0% +equation and +additional uh correction terms produce a + + align:start position:0% +additional uh correction terms produce a + + + align:start position:0% +additional uh correction terms produce a +will produce a convection diffusion + + align:start position:0% +will produce a convection diffusion + + + align:start position:0% +will produce a convection diffusion +equation so so this is a + + align:start position:0% +equation so so this is a + + + align:start position:0% +equation so so this is a +application that we wouldn't have made + + align:start position:0% +application that we wouldn't have made + + + align:start position:0% +application that we wouldn't have made +uh some years ago but now it's worth + + align:start position:0% +uh some years ago but now it's worth + + + align:start position:0% +uh some years ago but now it's worth +having uh focusing on that I think it's + + align:start position:0% +having uh focusing on that I think it's + + + align:start position:0% +having uh focusing on that I think it's +it's interesting itself and then so + + align:start position:0% +it's interesting itself and then so + + + align:start position:0% +it's interesting itself and then so +these this is what's coming and then uh + + align:start position:0% +these this is what's coming and then uh + + + align:start position:0% +these this is what's coming and then uh +you could say one-way wave equations but + + align:start position:0% +you could say one-way wave equations but + + + align:start position:0% +you could say one-way wave equations but +nonlinear so + + align:start position:0% + + + + align:start position:0% + +nonlinear wave equations and those are + + align:start position:0% +nonlinear wave equations and those are + + + align:start position:0% +nonlinear wave equations and those are +called conservation + + align:start position:0% +called conservation + + + align:start position:0% +called conservation +laws + + align:start position:0% + + + + align:start position:0% + +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +that's that's after these linear cases + + align:start position:0% +that's that's after these linear cases + + + align:start position:0% +that's that's after these linear cases +all right so I'm ready to tackle the + + align:start position:0% +all right so I'm ready to tackle the + + + align:start position:0% +all right so I'm ready to tackle the +heat + + align:start position:0% + + + + align:start position:0% + +equation starting then on to the next + + align:start position:0% +equation starting then on to the next + + + align:start position:0% +equation starting then on to the next +section of the notes okay so let me + + align:start position:0% +section of the notes okay so let me + + + align:start position:0% +section of the notes okay so let me +tackle it + + align:start position:0% +tackle it + + + align:start position:0% +tackle it +here so the heat equation + + align:start position:0% + + + + align:start position:0% + +let me take it take the constant to be 1 + + align:start position:0% +let me take it take the constant to be 1 + + + align:start position:0% +let me take it take the constant to be 1 +utal + + align:start position:0% +utal + + + align:start position:0% +utal +uxx okay because we already see the big + + align:start position:0% +uxx okay because we already see the big + + + align:start position:0% +uxx okay because we already see the big +difference now there's a second X + + align:start position:0% +difference now there's a second X + + + align:start position:0% +difference now there's a second X +derivative but only a first derivative + + align:start position:0% +derivative but only a first derivative + + + align:start position:0% +derivative but only a first derivative +in time the the the dimensions of T and + + align:start position:0% +in time the the the dimensions of T and + + + align:start position:0% +in time the the the dimensions of T and +X are not no longer the same we won't + + align:start position:0% +X are not no longer the same we won't + + + align:start position:0% +X are not no longer the same we won't +have delta T and Delta X comp + + align:start position:0% +have delta T and Delta X comp + + + align:start position:0% +have delta T and Delta X comp +comparable now it will be delta T + + align:start position:0% +comparable now it will be delta T + + + align:start position:0% +comparable now it will be delta T +comparable with Delta X SAR and that's a + + align:start position:0% +comparable with Delta X SAR and that's a + + + align:start position:0% +comparable with Delta X SAR and that's a +very significant difference because + + align:start position:0% +very significant difference because + + + align:start position:0% +very significant difference because +that's if Delta X is small Delta x^ s is + + align:start position:0% +that's if Delta X is small Delta x^ s is + + + align:start position:0% +that's if Delta X is small Delta x^ s is +extremely small so when delta T has to + + align:start position:0% +extremely small so when delta T has to + + + align:start position:0% +extremely small so when delta T has to +be is is constrained by Delta x^ squ + + align:start position:0% +be is is constrained by Delta x^ squ + + + align:start position:0% +be is is constrained by Delta x^ squ +we're we're looking at small time steps + + align:start position:0% +we're we're looking at small time steps + + + align:start position:0% +we're we're looking at small time steps +we're looking at stiff + + align:start position:0% +we're looking at stiff + + + align:start position:0% +we're looking at stiff +systems absolutely + + align:start position:0% +systems absolutely + + + align:start position:0% +systems absolutely +this is going to be a stiff problem + + align:start position:0% +this is going to be a stiff problem + + + align:start position:0% +this is going to be a stiff problem +because uh the low + + align:start position:0% +because uh the low + + + align:start position:0% +because uh the low +frequencies and the high frequencies + + align:start position:0% +frequencies and the high frequencies + + + align:start position:0% +frequencies and the high frequencies +differ enormously in the Decay rate in + + align:start position:0% +differ enormously in the Decay rate in + + + align:start position:0% +differ enormously in the Decay rate in +fact why don't we see it right away + + align:start position:0% +fact why don't we see it right away + + + align:start position:0% +fact why don't we see it right away +starting as always with exponentials so + + align:start position:0% +starting as always with exponentials so + + + align:start position:0% +starting as always with exponentials so +if I if I plug in U of x and t is some G + + align:start position:0% +if I if I plug in U of x and t is some G + + + align:start position:0% +if I if I plug in U of x and t is some G +of t e to the I + + align:start position:0% + + + + align:start position:0% + +KX separating variable as + + align:start position:0% + + + + align:start position:0% + +always look for a pure exponential + + align:start position:0% +always look for a pure exponential + + + align:start position:0% +always look for a pure exponential +solution plug that in we get + + align:start position:0% + + + + align:start position:0% + +dgdt time e to the I + + align:start position:0% +dgdt time e to the I + + + align:start position:0% +dgdt time e to the I +KX on the left and now I have to take + + align:start position:0% +KX on the left and now I have to take + + + align:start position:0% +KX on the left and now I have to take +two x derivatives so that brings ik K + + align:start position:0% +two x derivatives so that brings ik K + + + align:start position:0% +two x derivatives so that brings ik K +down + + align:start position:0% +down + + + align:start position:0% +down +twice so that's - k^ 2 i^ 2 giving the + + align:start position:0% +twice so that's - k^ 2 i^ 2 giving the + + + align:start position:0% +twice so that's - k^ 2 i^ 2 giving the +minus1 * G G * e to the I + + align:start position:0% + + + + align:start position:0% + +KX and now of course I can cancel that + + align:start position:0% +KX and now of course I can cancel that + + + align:start position:0% +KX and now of course I can cancel that +which is never + + align:start position:0% +which is never + + + align:start position:0% +which is never +zero and I've separated out the time + + align:start position:0% +zero and I've separated out the time + + + align:start position:0% +zero and I've separated out the time +part the G part dgdt is minus k 2 G so G + + align:start position:0% +part the G part dgdt is minus k 2 G so G + + + align:start position:0% +part the G part dgdt is minus k 2 G so G +is e the minus k^ 2 T notice that it's k + + align:start position:0% +is e the minus k^ 2 T notice that it's k + + + align:start position:0% +is e the minus k^ 2 T notice that it's k +a squ that's the and notice that it's + + align:start position:0% +a squ that's the and notice that it's + + + align:start position:0% +a squ that's the and notice that it's +real and negative see that's a very big + + align:start position:0% +real and negative see that's a very big + + + align:start position:0% +real and negative see that's a very big +difference compare with + + align:start position:0% + + + + align:start position:0% + +compare e to the ik e to the ik + + align:start position:0% +compare e to the ik e to the ik + + + align:start position:0% +compare e to the ik e to the ik +CT which it was for the one-way wave + + align:start position:0% +CT which it was for the one-way wave + + + align:start position:0% +CT which it was for the one-way wave +equation the difference is enormous here + + align:start position:0% +equation the difference is enormous here + + + align:start position:0% +equation the difference is enormous here +the the uh + + align:start position:0% +the the uh + + + align:start position:0% +the the uh +that's magnitude one energy + + align:start position:0% +that's magnitude one energy + + + align:start position:0% +that's magnitude one energy +conserved this is magnitude smaller than + + align:start position:0% +conserved this is magnitude smaller than + + + align:start position:0% +conserved this is magnitude smaller than +one energy + + align:start position:0% + + + + align:start position:0% + +dissipated this + + align:start position:0% +dissipated this + + + align:start position:0% +dissipated this +uh we + + align:start position:0% +uh we + + + align:start position:0% +uh we +had a ratio delta T over Delta X now + + align:start position:0% +had a ratio delta T over Delta X now + + + align:start position:0% +had a ratio delta T over Delta X now +we're going to see delta T over Delta X + + align:start position:0% +we're going to see delta T over Delta X + + + align:start position:0% +we're going to see delta T over Delta X +squ because + + align:start position:0% +squ because + + + align:start position:0% +squ because +somehow x and t are are are now have uh + + align:start position:0% +somehow x and t are are are now have uh + + + align:start position:0% +somehow x and t are are are now have uh +it's x s that matches T now okay so + + align:start position:0% +it's x s that matches T now okay so + + + align:start position:0% +it's x s that matches T now okay so +that's so now when I put that into here + + align:start position:0% +that's so now when I put that into here + + + align:start position:0% +that's so now when I put that into here +let me just do it g of T is eus k 2 T so + + align:start position:0% +let me just do it g of T is eus k 2 T so + + + align:start position:0% +let me just do it g of T is eus k 2 T so +there is the pure + + align:start position:0% +there is the pure + + + align:start position:0% +there is the pure +exponential simple as always because we + + align:start position:0% +exponential simple as always because we + + + align:start position:0% +exponential simple as always because we +have constant coefficients but highly + + align:start position:0% +have constant coefficients but highly + + + align:start position:0% +have constant coefficients but highly +informative I I guess another thing that + + align:start position:0% +informative I I guess another thing that + + + align:start position:0% +informative I I guess another thing that +I read off of that is what what + + align:start position:0% +I read off of that is what what + + + align:start position:0% +I read off of that is what what +frequencies are decaying fast high + + align:start position:0% +frequencies are decaying fast high + + + align:start position:0% +frequencies are decaying fast high +frequencies if k is + + align:start position:0% +frequencies if k is + + + align:start position:0% +frequencies if k is +large k^2 is very large and E Theus k^2 + + align:start position:0% +large k^2 is very large and E Theus k^2 + + + align:start position:0% +large k^2 is very large and E Theus k^2 +T is decaying very quickly so oscill + + align:start position:0% +T is decaying very quickly so oscill + + + align:start position:0% +T is decaying very quickly so oscill +high frequency noise in the system + + align:start position:0% +high frequency noise in the system + + + align:start position:0% +high frequency noise in the system +roughness discontinuities are going to + + align:start position:0% +roughness discontinuities are going to + + + align:start position:0% +roughness discontinuities are going to +get smoothed + + align:start position:0% +get smoothed + + + align:start position:0% +get smoothed +out strongly by moving forward in time + + align:start position:0% +out strongly by moving forward in time + + + align:start position:0% +out strongly by moving forward in time +and physically what's happening is we + + align:start position:0% +and physically what's happening is we + + + align:start position:0% +and physically what's happening is we +have like our + + align:start position:0% +have like our + + + align:start position:0% +have like our +wavefront which stayed a + + align:start position:0% +wavefront which stayed a + + + align:start position:0% +wavefront which stayed a +perfect step function in the wave + + align:start position:0% +perfect step function in the wave + + + align:start position:0% +perfect step function in the wave +equation will + + align:start position:0% +equation will + + + align:start position:0% +equation will +instantly + + align:start position:0% +instantly + + + align:start position:0% +instantly +smear so diffusion smears + + align:start position:0% + + + + align:start position:0% + +discontinuities heat heat travels if we + + align:start position:0% +discontinuities heat heat travels if we + + + align:start position:0% +discontinuities heat heat travels if we +were back over + + align:start position:0% +were back over + + + align:start position:0% +were back over +here if the temperature starts out as + + align:start position:0% +here if the temperature starts out as + + + align:start position:0% +here if the temperature starts out as +one on this side and zero on this side + + align:start position:0% +one on this side and zero on this side + + + align:start position:0% +one on this side and zero on this side +then in an instant some + + align:start position:0% +then in an instant some + + + align:start position:0% +then in an instant some +heat flows from right to left in fact it + + align:start position:0% +heat flows from right to left in fact it + + + align:start position:0% +heat flows from right to left in fact it +flows at with infinite speed the in a in + + align:start position:0% +flows at with infinite speed the in a in + + + align:start position:0% +flows at with infinite speed the in a in +a short delta T there's a little heat + + align:start position:0% +a short delta T there's a little heat + + + align:start position:0% +a short delta T there's a little heat +all the way out there very little of + + align:start position:0% +all the way out there very little of + + + align:start position:0% +all the way out there very little of +course because it's uh well I guess we + + align:start position:0% +course because it's uh well I guess we + + + align:start position:0% +course because it's uh well I guess we +want to see how what that behavior + + align:start position:0% +want to see how what that behavior + + + align:start position:0% +want to see how what that behavior +is so and now want to write down staying + + align:start position:0% +is so and now want to write down staying + + + align:start position:0% +is so and now want to write down staying +with the differential + + align:start position:0% +with the differential + + + align:start position:0% +with the differential +equation what do we want to + + align:start position:0% +equation what do we want to + + + align:start position:0% +equation what do we want to +do we did the exponential + + align:start position:0% +do we did the exponential + + + align:start position:0% +do we did the exponential +case and learned a good bit from that + + align:start position:0% +case and learned a good bit from that + + + align:start position:0% +case and learned a good bit from that +the quick the fast decay of high + + align:start position:0% +the quick the fast decay of high + + + align:start position:0% +the quick the fast decay of high +frequencies but now comes the The Next + + align:start position:0% +frequencies but now comes the The Next + + + align:start position:0% +frequencies but now comes the The Next +Step would be to put different + + align:start position:0% +Step would be to put different + + + align:start position:0% +Step would be to put different +frequencies different KS + + align:start position:0% +frequencies different KS + + + align:start position:0% +frequencies different KS +together by linearity we can add these + + align:start position:0% +together by linearity we can add these + + + align:start position:0% +together by linearity we can add these +Solutions we can multiply by + + align:start position:0% +Solutions we can multiply by + + + align:start position:0% +Solutions we can multiply by +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +any we can multiply that by any numbers + + align:start position:0% +any we can multiply that by any numbers + + + align:start position:0% +any we can multiply that by any numbers +we want depending on K we still have + + align:start position:0% +we want depending on K we still have + + + align:start position:0% +we want depending on K we still have +Solutions and we can integrate over K so + + align:start position:0% +Solutions and we can integrate over K so + + + align:start position:0% +Solutions and we can integrate over K so +we will actually that that will be the + + align:start position:0% +we will actually that that will be the + + + align:start position:0% +we will actually that that will be the +that will be the next step let me write + + align:start position:0% +that will be the next step let me write + + + align:start position:0% +that will be the next step let me write +down what that does I I'll I'm going to + + align:start position:0% +down what that does I I'll I'm going to + + + align:start position:0% +down what that does I I'll I'm going to +jump take a little jump + + align:start position:0% +jump take a little jump + + + align:start position:0% +jump take a little jump +here to put on the board what I just + + align:start position:0% +here to put on the board what I just + + + align:start position:0% +here to put on the board what I just +said in words I can multiply this e + + align:start position:0% +said in words I can multiply this e + + + align:start position:0% +said in words I can multiply this e +minus k^ 2 t e to the I + + align:start position:0% +minus k^ 2 t e to the I + + + align:start position:0% +minus k^ 2 t e to the I +KX that's what's happening to frequence + + align:start position:0% +KX that's what's happening to frequence + + + align:start position:0% +KX that's what's happening to frequence +to the pure frequency K If I multiply + + align:start position:0% +to the pure frequency K If I multiply + + + align:start position:0% +to the pure frequency K If I multiply +that + + align:start position:0% +that + + + align:start position:0% +that +by the + + align:start position:0% +by the + + + align:start position:0% +by the +amount of that + + align:start position:0% + + + + align:start position:0% + +frequency which is in the initial + + align:start position:0% +frequency which is in the initial + + + align:start position:0% +frequency which is in the initial +condition so here's the initial + + align:start position:0% +condition so here's the initial + + + align:start position:0% +condition so here's the initial +condition you + + align:start position:0% +condition you + + + align:start position:0% +condition you +Z and I've taken its 4A transform this + + align:start position:0% +Z and I've taken its 4A transform this + + + align:start position:0% +Z and I've taken its 4A transform this +tells me how much of frequency K is in + + align:start position:0% +tells me how much of frequency K is in + + + align:start position:0% +tells me how much of frequency K is in +the problem is in the initial + + align:start position:0% +the problem is in the initial + + + align:start position:0% +the problem is in the initial +problem this tells me how much of + + align:start position:0% +problem this tells me how much of + + + align:start position:0% +problem this tells me how much of +frequency K is in the initial + + align:start position:0% +frequency K is in the initial + + + align:start position:0% +frequency K is in the initial +problem that amount multiplies this with + + align:start position:0% +problem that amount multiplies this with + + + align:start position:0% +problem that amount multiplies this with +this rapid Decay as time goes forward + + align:start position:0% +this rapid Decay as time goes forward + + + align:start position:0% +this rapid Decay as time goes forward +but at any later time I'm just adding up + + align:start position:0% +but at any later time I'm just adding up + + + align:start position:0% +but at any later time I'm just adding up +and since K we're on the whole line K is + + align:start position:0% +and since K we're on the whole line K is + + + align:start position:0% +and since K we're on the whole line K is +a + + align:start position:0% +a + + + align:start position:0% +a +continuous so there's we add up from K = + + align:start position:0% +continuous so there's we add up from K = + + + align:start position:0% +continuous so there's we add up from K = +minus infinity to infinity and I think + + align:start position:0% +minus infinity to infinity and I think + + + align:start position:0% +minus infinity to infinity and I think +we have to remember the 2 pi that + + align:start position:0% +we have to remember the 2 pi that + + + align:start position:0% +we have to remember the 2 pi that +depends on our particular definition of + + align:start position:0% +depends on our particular definition of + + + align:start position:0% +depends on our particular definition of +the transform but I I'm going to stay + + align:start position:0% +the transform but I I'm going to stay + + + align:start position:0% +the transform but I I'm going to stay +with this one that's the answer that's U + + align:start position:0% +with this one that's the answer that's U + + + align:start position:0% +with this one that's the answer that's U +of x and + + align:start position:0% + + + + align:start position:0% + +t + + align:start position:0% + + + + align:start position:0% + +so I've said that in words but actually + + align:start position:0% +so I've said that in words but actually + + + align:start position:0% +so I've said that in words but actually +we could just check + + align:start position:0% +we could just check + + + align:start position:0% +we could just check +it we would like to know that this left + + align:start position:0% +it we would like to know that this left + + + align:start position:0% +it we would like to know that this left +hand side solves the heat equation and + + align:start position:0% +hand side solves the heat equation and + + + align:start position:0% +hand side solves the heat equation and +we would like to know that it has the + + align:start position:0% +we would like to know that it has the + + + align:start position:0% +we would like to know that it has the +correct start the correct U of X and + + align:start position:0% +correct start the correct U of X and + + + align:start position:0% +correct start the correct U of X and +zero well let's check that at T equals z + + align:start position:0% +zero well let's check that at T equals z + + + align:start position:0% +zero well let's check that at T equals z +at the start this is + + align:start position:0% +at the start this is + + + align:start position:0% +at the start this is +one so at the + + align:start position:0% +one so at the + + + align:start position:0% +one so at the +start this formula without that thing + + align:start position:0% +start this formula without that thing + + + align:start position:0% +start this formula without that thing +there is just the inverse fora transform + + align:start position:0% +there is just the inverse fora transform + + + align:start position:0% +there is just the inverse fora transform +that takes the 4 a transform multiplies + + align:start position:0% +that takes the 4 a transform multiplies + + + align:start position:0% +that takes the 4 a transform multiplies +by this integrates to recover u + + align:start position:0% +by this integrates to recover u + + + align:start position:0% +by this integrates to recover u +u so it does start out + + align:start position:0% + + + + align:start position:0% + +correctly should I say that again it + + align:start position:0% +correctly should I say that again it + + + align:start position:0% +correctly should I say that again it +starts correctly because at T equals 0 + + align:start position:0% +starts correctly because at T equals 0 + + + align:start position:0% +starts correctly because at T equals 0 +this is just the inverse 4 a transform + + align:start position:0% +this is just the inverse 4 a transform + + + align:start position:0% +this is just the inverse 4 a transform +of u0 so it produces + + align:start position:0% + + + + align:start position:0% + +U it inverts this transform that we + + align:start position:0% +U it inverts this transform that we + + + align:start position:0% +U it inverts this transform that we +took secondly does it solve the heat + + align:start position:0% +took secondly does it solve the heat + + + align:start position:0% +took secondly does it solve the heat +equation sure because for each + + align:start position:0% +equation sure because for each + + + align:start position:0% +equation sure because for each +K we've just found that that solves the + + align:start position:0% +K we've just found that that solves the + + + align:start position:0% +K we've just found that that solves the +heat equation and now we're just putting + + align:start position:0% +heat equation and now we're just putting + + + align:start position:0% +heat equation and now we're just putting +different KS + + align:start position:0% +different KS + + + align:start position:0% +different KS +together so that's the answer it's so + + align:start position:0% +together so that's the answer it's so + + + align:start position:0% +together so that's the answer it's so +you might say Okay + + align:start position:0% +you might say Okay + + + align:start position:0% +you might say Okay +Perfection + + align:start position:0% +Perfection + + + align:start position:0% +Perfection +we don't + + align:start position:0% +we don't + + + align:start position:0% +we don't +uh do do we need uh finite + + align:start position:0% +uh do do we need uh finite + + + align:start position:0% +uh do do we need uh finite +differences well I guess we do this is + + align:start position:0% +differences well I guess we do this is + + + align:start position:0% +differences well I guess we do this is +typical + + align:start position:0% + + + + align:start position:0% + +of formulas that give the answer exactly + + align:start position:0% +of formulas that give the answer exactly + + + align:start position:0% +of formulas that give the answer exactly +but in terms that are not numerically + + align:start position:0% +but in terms that are not numerically + + + align:start position:0% +but in terms that are not numerically +convenient because look what we have to + + align:start position:0% +convenient because look what we have to + + + align:start position:0% +convenient because look what we have to +use this Formula First of all this this + + align:start position:0% +use this Formula First of all this this + + + align:start position:0% +use this Formula First of all this this +requires an integral an infinite + + align:start position:0% +requires an integral an infinite + + + align:start position:0% +requires an integral an infinite +integral + + align:start position:0% + + + + align:start position:0% + +to find integral to find for + + align:start position:0% +to find integral to find for + + + align:start position:0% +to find integral to find for +un you not U hat we would have + + align:start position:0% +un you not U hat we would have + + + align:start position:0% +un you not U hat we would have +to to use this formula we'd have to find + + align:start position:0% +to to use this formula we'd have to find + + + align:start position:0% +to to use this formula we'd have to find +this transform and then we have to do + + align:start position:0% +this transform and then we have to do + + + align:start position:0% +this transform and then we have to do +this + + align:start position:0% +this + + + align:start position:0% +this +integral for the inverse + + align:start position:0% +integral for the inverse + + + align:start position:0% +integral for the inverse +transform this + + align:start position:0% + + + + align:start position:0% + +integral + + align:start position:0% +integral + + + align:start position:0% +integral +for the answer U + + align:start position:0% +for the answer U + + + align:start position:0% +for the answer U +two infinite + + align:start position:0% + + + + align:start position:0% + +integrals and not to mention the fact + + align:start position:0% +integrals and not to mention the fact + + + align:start position:0% +integrals and not to mention the fact +that on a finite + + align:start position:0% +that on a finite + + + align:start position:0% +that on a finite +interval when X doesn't go all the way + + align:start position:0% +interval when X doesn't go all the way + + + align:start position:0% +interval when X doesn't go all the way +from minus infinity to Infinity we've + + align:start position:0% +from minus infinity to Infinity we've + + + align:start position:0% +from minus infinity to Infinity we've +the formula we have to think all over + + align:start position:0% +the formula we have to think all over + + + align:start position:0% +the formula we have to think all over +again so we have a nice formula for the + + align:start position:0% +again so we have a nice formula for the + + + align:start position:0% +again so we have a nice formula for the +answer + + align:start position:0% +answer + + + align:start position:0% +answer +but it looks nice but it's not + + align:start position:0% +but it looks nice but it's not + + + align:start position:0% +but it looks nice but it's not +numerically + + align:start position:0% +numerically + + + align:start position:0% +numerically +terrific uh we can get a lot of + + align:start position:0% +terrific uh we can get a lot of + + + align:start position:0% +terrific uh we can get a lot of +information out of this and there's one + + align:start position:0% +information out of this and there's one + + + align:start position:0% +information out of this and there's one +other special solution that that's also + + align:start position:0% +other special solution that that's also + + + align:start position:0% +other special solution that that's also +extremely + + align:start position:0% +extremely + + + align:start position:0% +extremely +informative what + + align:start position:0% +informative what + + + align:start position:0% +informative what +if so I'm going to do a special case but + + align:start position:0% +if so I'm going to do a special case but + + + align:start position:0% +if so I'm going to do a special case but +it's the big case what if it's what if + + align:start position:0% +it's the big case what if it's what if + + + align:start position:0% +it's the big case what if it's what if +the initial condition is a Delta + + align:start position:0% +the initial condition is a Delta + + + align:start position:0% +the initial condition is a Delta +function + + align:start position:0% +function + + + align:start position:0% +function +what if the initial condition is a Delta + + align:start position:0% + + + + align:start position:0% + +function an Impulse a Time + + align:start position:0% +function an Impulse a Time + + + align:start position:0% +function an Impulse a Time +Zero x equals z an an instant source of + + align:start position:0% + + + + align:start position:0% + +heat at at a point a point source a + + align:start position:0% +heat at at a point a point source a + + + align:start position:0% +heat at at a point a point source a +point source with finite strength you + + align:start position:0% +point source with finite strength you + + + align:start position:0% +point source with finite strength you +could say an + + align:start position:0% +could say an + + + align:start position:0% +could say an +Impulse at Time + + align:start position:0% + + + + align:start position:0% + +Zero + + align:start position:0% +Zero + + + align:start position:0% +Zero +for uh the wave equation what happened + + align:start position:0% +for uh the wave equation what happened + + + align:start position:0% +for uh the wave equation what happened +that was like turning on a flash of + + align:start position:0% +that was like turning on a flash of + + + align:start position:0% +that was like turning on a flash of +light and it went along the + + align:start position:0% +light and it went along the + + + align:start position:0% +light and it went along the +characteristics for the heat + + align:start position:0% +characteristics for the heat + + + align:start position:0% +characteristics for the heat +equation uh it'll be quite + + align:start position:0% +equation uh it'll be quite + + + align:start position:0% +equation uh it'll be quite +different there aren't characteristics + + align:start position:0% +different there aren't characteristics + + + align:start position:0% +different there aren't characteristics +here we but this is an extremely + + align:start position:0% +here we but this is an extremely + + + align:start position:0% +here we but this is an extremely +important solution and and I think you + + align:start position:0% +important solution and and I think you + + + align:start position:0% +important solution and and I think you +could call it the the fundamental + + align:start position:0% +could call it the the fundamental + + + align:start position:0% +could call it the the fundamental +solution to the heat equation + + align:start position:0% + + + + align:start position:0% + +you may know what it is you may have + + align:start position:0% +you may know what it is you may have + + + align:start position:0% +you may know what it is you may have +seen this + + align:start position:0% +seen this + + + align:start position:0% +seen this +formula it's fantastic that + + align:start position:0% +formula it's fantastic that + + + align:start position:0% +formula it's fantastic that +we get a formula for this one well you + + align:start position:0% +we get a formula for this one well you + + + align:start position:0% +we get a formula for this one well you +could say we've got a + + align:start position:0% +could say we've got a + + + align:start position:0% +could say we've got a +formula what's the 4A transform what's + + align:start position:0% +formula what's the 4A transform what's + + + align:start position:0% +formula what's the 4A transform what's +un not hat of K for the Delta + + align:start position:0% + + + + align:start position:0% + +function one right the 4A transform + + align:start position:0% +function one right the 4A transform + + + align:start position:0% +function one right the 4A transform +of the Delta function is a constant one + + align:start position:0% +of the Delta function is a constant one + + + align:start position:0% +of the Delta function is a constant one +all frequencies are there in equal + + align:start position:0% +all frequencies are there in equal + + + align:start position:0% +all frequencies are there in equal +amounts this is a constant so I can + + align:start position:0% +amounts this is a constant so I can + + + align:start position:0% +amounts this is a constant so I can +remove it it's one and I'm left with a + + align:start position:0% +remove it it's one and I'm left with a + + + align:start position:0% +remove it it's one and I'm left with a +specific integral to + + align:start position:0% +specific integral to + + + align:start position:0% +specific integral to +do and the question is can I do + + align:start position:0% +do and the question is can I do + + + align:start position:0% +do and the question is can I do +it and the answer turns out to be yes + + align:start position:0% +it and the answer turns out to be yes + + + align:start position:0% +it and the answer turns out to be yes +you can do that integral with when this + + align:start position:0% +you can do that integral with when this + + + align:start position:0% +you can do that integral with when this +is a constant and that will give you the + + align:start position:0% +is a constant and that will give you the + + + align:start position:0% +is a constant and that will give you the +answer + + align:start position:0% +answer + + + align:start position:0% +answer +with that starting value and let me just + + align:start position:0% +with that starting value and let me just + + + align:start position:0% +with that starting value and let me just +say what that answer is U of x and t + + align:start position:0% +say what that answer is U of x and t + + + align:start position:0% +say what that answer is U of x and t +this is the fundamental solution U + + align:start position:0% +this is the fundamental solution U + + + align:start position:0% +this is the fundamental solution U +fundamental maybe I should + + align:start position:0% +fundamental maybe I should + + + align:start position:0% +fundamental maybe I should +say because it's such an important case + + align:start position:0% +say because it's such an important case + + + align:start position:0% +say because it's such an important case +is turns out to be well it's not obvious + + align:start position:0% +is turns out to be well it's not obvious + + + align:start position:0% +is turns out to be well it's not obvious +what that integral + + align:start position:0% +what that integral + + + align:start position:0% +what that integral +is and by the way + + align:start position:0% +is and by the way + + + align:start position:0% +is and by the way +normally + + align:start position:0% +normally + + + align:start position:0% +normally +uh + + align:start position:0% +uh + + + align:start position:0% +uh +but let's see yeah + + align:start position:0% +but let's see yeah + + + align:start position:0% +but let's see yeah +uh yeah Norm normally + + align:start position:0% +uh yeah Norm normally + + + align:start position:0% +uh yeah Norm normally +it's we take a kind of to to get the + + align:start position:0% +it's we take a kind of to to get the + + + align:start position:0% +it's we take a kind of to to get the +answer that I'm going to write down we + + align:start position:0% +answer that I'm going to write down we + + + align:start position:0% +answer that I'm going to write down we +take a kind of uh end run on the + + align:start position:0% +take a kind of uh end run on the + + + align:start position:0% +take a kind of uh end run on the +integral and I'm going to take a serious + + align:start position:0% +integral and I'm going to take a serious + + + align:start position:0% +integral and I'm going to take a serious +end run and write down the answer + + align:start position:0% +end run and write down the answer + + + align:start position:0% +end run and write down the answer +exactly uh + + align:start position:0% +exactly uh + + + align:start position:0% +exactly uh +there's here here's the key part of the + + align:start position:0% +there's here here's the key part of the + + + align:start position:0% +there's here here's the key part of the +answer + + align:start position:0% + + + + align:start position:0% + +answer the solution which starts from a + + align:start position:0% +answer the solution which starts from a + + + align:start position:0% +answer the solution which starts from a +Delta function spreads of + + align:start position:0% +Delta function spreads of + + + align:start position:0% +Delta function spreads of +course and the shape as it spreads is a + + align:start position:0% +course and the shape as it spreads is a + + + align:start position:0% +course and the shape as it spreads is a +bell it's the famous bell-shaped + + align:start position:0% +bell it's the famous bell-shaped + + + align:start position:0% +bell it's the famous bell-shaped +gaussian + + align:start position:0% +gaussian + + + align:start position:0% +gaussian +distribution of e to the + + align:start position:0% + + + + align:start position:0% + +minus so is it eus x^2 I + + align:start position:0% +minus so is it eus x^2 I + + + align:start position:0% +minus so is it eus x^2 I +guess and then always here comes the + + align:start position:0% +guess and then always here comes the + + + align:start position:0% +guess and then always here comes the +that scaler tells us the width of the + + align:start position:0% +that scaler tells us the width of the + + + align:start position:0% +that scaler tells us the width of the +Bell what how far has it spread at time + + align:start position:0% +Bell what how far has it spread at time + + + align:start position:0% +Bell what how far has it spread at time +T and what goes there is + + align:start position:0% + + + + align:start position:0% + +4T that that's the key observation and + + align:start position:0% +4T that that's the key observation and + + + align:start position:0% +4T that that's the key observation and +notice how X2 and T are are coming in + + align:start position:0% +notice how X2 and T are are coming in + + + align:start position:0% +notice how X2 and T are are coming in +it's that ratio x^2 to T that's + + align:start position:0% +it's that ratio x^2 to T that's + + + align:start position:0% +it's that ratio x^2 to T that's +crucial that that's that's the the the + + align:start position:0% +crucial that that's that's the the the + + + align:start position:0% +crucial that that's that's the the the +parameter here and uh and we and of + + align:start position:0% +parameter here and uh and we and of + + + align:start position:0% +parameter here and uh and we and of +course we need to multiply by a + + align:start position:0% + + + + align:start position:0% + +constant and the why how do I know I + + align:start position:0% +constant and the why how do I know I + + + align:start position:0% +constant and the why how do I know I +need a constant because I because the + + align:start position:0% + + + + align:start position:0% + +total the total heat is + + align:start position:0% + + + + align:start position:0% + +conserved so the in other words the + + align:start position:0% +conserved so the in other words the + + + align:start position:0% +conserved so the in other words the +integral of the Delta function the + + align:start position:0% +integral of the Delta function the + + + align:start position:0% +integral of the Delta function the +original source of + + align:start position:0% +original source of + + + align:start position:0% +original source of +heat was one the integral from minus + + align:start position:0% +heat was one the integral from minus + + + align:start position:0% +heat was one the integral from minus +infinity to Infinity of the Delta + + align:start position:0% +infinity to Infinity of the Delta + + + align:start position:0% +infinity to Infinity of the Delta +function which is all totally + + align:start position:0% +function which is all totally + + + align:start position:0% +function which is all totally +concentrated at one point is one so I + + align:start position:0% +concentrated at one point is one so I + + + align:start position:0% +concentrated at one point is one so I +need to put on whatever constant it + + align:start position:0% +need to put on whatever constant it + + + align:start position:0% +need to put on whatever constant it +takes so that the integral of this thing + + align:start position:0% +takes so that the integral of this thing + + + align:start position:0% +takes so that the integral of this thing +shall stay one for later times so and it + + align:start position:0% +shall stay one for later times so and it + + + align:start position:0% +shall stay one for later times so and it +this is a this is one integral from + + align:start position:0% +this is a this is one integral from + + + align:start position:0% +this is a this is one integral from +minus infinity to Infinity that we can + + align:start position:0% +minus infinity to Infinity that we can + + + align:start position:0% +minus infinity to Infinity that we can +do and it turns out to need 1 over the < + + align:start position:0% +do and it turns out to need 1 over the < + + + align:start position:0% +do and it turns out to need 1 over the < +TK of 4 Pi + + align:start position:0% +TK of 4 Pi + + + align:start position:0% +TK of 4 Pi +t + + align:start position:0% +t + + + align:start position:0% +t +that's + + align:start position:0% +that's + + + align:start position:0% +that's +a that solves the heat + + align:start position:0% + + + + align:start position:0% + +equation well it's not a lot of fun to + + align:start position:0% +equation well it's not a lot of fun to + + + align:start position:0% +equation well it's not a lot of fun to +plug that into the heat + + align:start position:0% + + + + align:start position:0% + +equation but it's possible Right the X + + align:start position:0% +equation but it's possible Right the X + + + align:start position:0% +equation but it's possible Right the X +derivative the time derivative is going + + align:start position:0% +derivative the time derivative is going + + + align:start position:0% +derivative the time derivative is going +to be messy it'll have two terms the X + + align:start position:0% +to be messy it'll have two terms the X + + + align:start position:0% +to be messy it'll have two terms the X +derivative will have two terms and + + align:start position:0% +derivative will have two terms and + + + align:start position:0% +derivative will have two terms and +they'll agree yeah + + align:start position:0% +they'll agree yeah + + + align:start position:0% +they'll agree yeah +yeah and the notes will give one way to + + align:start position:0% +yeah and the notes will give one way to + + + align:start position:0% +yeah and the notes will give one way to +do the integral and get that answer + + align:start position:0% +do the integral and get that answer + + + align:start position:0% +do the integral and get that answer +right right you see that that integral + + align:start position:0% +right right you see that that integral + + + align:start position:0% +right right you see that that integral +it's integrals with e minus + + align:start position:0% +it's integrals with e minus + + + align:start position:0% +it's integrals with e minus +k^2 in them are + + align:start position:0% + + + + align:start position:0% + +uh are usually are are impossible on a + + align:start position:0% +uh are usually are are impossible on a + + + align:start position:0% +uh are usually are are impossible on a +finite + + align:start position:0% +finite + + + align:start position:0% +finite +interval but here we're going all the + + align:start position:0% +interval but here we're going all the + + + align:start position:0% +interval but here we're going all the +way from minus infinity to Infinity + + align:start position:0% +way from minus infinity to Infinity + + + align:start position:0% +way from minus infinity to Infinity +which you might think makes the problem + + align:start position:0% +which you might think makes the problem + + + align:start position:0% +which you might think makes the problem +harder but actually it makes it a great + + align:start position:0% +harder but actually it makes it a great + + + align:start position:0% +harder but actually it makes it a great +deal easier and and we get we can get an + + align:start position:0% +deal easier and and we get we can get an + + + align:start position:0% +deal easier and and we get we can get an +explicit answer a beautiful + + align:start position:0% +explicit answer a beautiful + + + align:start position:0% +explicit answer a beautiful +answer so we learn that the solution to + + align:start position:0% +answer so we learn that the solution to + + + align:start position:0% +answer so we learn that the solution to +the heat + + align:start position:0% +the heat + + + align:start position:0% +the heat +equation is coming from a point source + + align:start position:0% +equation is coming from a point source + + + align:start position:0% +equation is coming from a point source +is a bell-shaped gaussian curve that + + align:start position:0% +is a bell-shaped gaussian curve that + + + align:start position:0% +is a bell-shaped gaussian curve that +gets wider and wider as T increases + + align:start position:0% +gets wider and wider as T increases + + + align:start position:0% +gets wider and wider as T increases +and but I guess you would want to look + + align:start position:0% +and but I guess you would want to look + + + align:start position:0% +and but I guess you would want to look +to see well what happens if t comes down + + align:start position:0% +to see well what happens if t comes down + + + align:start position:0% +to see well what happens if t comes down +to + + align:start position:0% +to + + + align:start position:0% +to +zero does that really + + align:start position:0% +zero does that really + + + align:start position:0% +zero does that really +approximate should I'm meant to say does + + align:start position:0% +approximate should I'm meant to say does + + + align:start position:0% +approximate should I'm meant to say does +it really converge + + align:start position:0% +it really converge + + + align:start position:0% +it really converge +to this should as T goes to zero this + + align:start position:0% +to this should as T goes to zero this + + + align:start position:0% +to this should as T goes to zero this +should go to the Delta + + align:start position:0% + + + + align:start position:0% + +function and in some way it does in some + + align:start position:0% +function and in some way it does in some + + + align:start position:0% +function and in some way it does in some +way it does it's a it's wonderful + + align:start position:0% + + + + align:start position:0% + +the Delta + + align:start position:0% +the Delta + + + align:start position:0% +the Delta +function of course is zero away from the + + align:start position:0% +function of course is zero away from the + + + align:start position:0% +function of course is zero away from the +origin so why does this approach zero + + align:start position:0% +origin so why does this approach zero + + + align:start position:0% +origin so why does this approach zero +away from the origin suppose X is one + + align:start position:0% +away from the origin suppose X is one + + + align:start position:0% +away from the origin suppose X is one +suppose X is one + + align:start position:0% +suppose X is one + + + align:start position:0% +suppose X is one +then do you see this thing going to zero + + align:start position:0% +then do you see this thing going to zero + + + align:start position:0% +then do you see this thing going to zero +as T goes to zero look look what's + + align:start position:0% +as T goes to zero look look what's + + + align:start position:0% +as T goes to zero look look what's +happening as T goes to zero this part is + + align:start position:0% +happening as T goes to zero this part is + + + align:start position:0% +happening as T goes to zero this part is +blowing up but kind of weakly that's not + + align:start position:0% +blowing up but kind of weakly that's not + + + align:start position:0% +blowing up but kind of weakly that's not +a disastrous + + align:start position:0% +a disastrous + + + align:start position:0% +a disastrous +blowup compared to this e to the minus + + align:start position:0% +blowup compared to this e to the minus + + + align:start position:0% +blowup compared to this e to the minus +let's say 1 over 4T as T goes to zero + + align:start position:0% +let's say 1 over 4T as T goes to zero + + + align:start position:0% +let's say 1 over 4T as T goes to zero +that's e to the to a very negative + + align:start position:0% +that's e to the to a very negative + + + align:start position:0% +that's e to the to a very negative +exponent that's going to zero very fast + + align:start position:0% +exponent that's going to zero very fast + + + align:start position:0% +exponent that's going to zero very fast +much faster than this is going to zero + + align:start position:0% +much faster than this is going to zero + + + align:start position:0% +much faster than this is going to zero +so if you like to think of lal's rule or + + align:start position:0% +so if you like to think of lal's rule or + + + align:start position:0% +so if you like to think of lal's rule or +Ratio or something this this quantity is + + align:start position:0% +Ratio or something this this quantity is + + + align:start position:0% +Ratio or something this this quantity is +going to zero way faster than this one + + align:start position:0% +going to zero way faster than this one + + + align:start position:0% +going to zero way faster than this one +is and the result is zero except at the + + align:start position:0% +is and the result is zero except at the + + + align:start position:0% +is and the result is zero except at the +one point x equals 0 where this is + + align:start position:0% +one point x equals 0 where this is + + + align:start position:0% +one point x equals 0 where this is +one and + + align:start position:0% +one and + + + align:start position:0% +one and +the the fact that the total amount of + + align:start position:0% +the the fact that the total amount of + + + align:start position:0% +the the fact that the total amount of +heat stays at one tells us that the + + align:start position:0% +heat stays at one tells us that the + + + align:start position:0% +heat stays at one tells us that the +Delta function is the limit there okay + + align:start position:0% +Delta function is the limit there okay + + + align:start position:0% +Delta function is the limit there okay +so that's uh + + align:start position:0% +so that's uh + + + align:start position:0% +so that's uh +today was the heat + + align:start position:0% +today was the heat + + + align:start position:0% +today was the heat +equation ous + + align:start position:0% +equation ous + + + align:start position:0% +equation ous +case with these explicit answers and uh + + align:start position:0% +case with these explicit answers and uh + + + align:start position:0% +case with these explicit answers and uh +and then next next time is tomorrow I + + align:start position:0% +and then next next time is tomorrow I + + + align:start position:0% +and then next next time is tomorrow I +guess is the heat equation finite + + align:start position:0% +guess is the heat equation finite + + + align:start position:0% +guess is the heat equation finite +differences and again we'll have several + + align:start position:0% +differences and again we'll have several + + + align:start position:0% +differences and again we'll have several +difference + + align:start position:0% +difference + + + align:start position:0% +difference +methods and to compare them would be + + align:start position:0% +methods and to compare them would be + + + align:start position:0% +methods and to compare them would be +terrific so maybe that please think + + align:start position:0% +terrific so maybe that please think + + + align:start position:0% +terrific so maybe that please think +about that comparison with the heat + + align:start position:0% +about that comparison with the heat + + + align:start position:0% +about that comparison with the heat +equation and or for what I was saying at + + align:start position:0% +equation and or for what I was saying at + + + align:start position:0% +equation and or for what I was saying at +the beginning of class the a deeper look + + align:start position:0% +the beginning of class the a deeper look + + + align:start position:0% +the beginning of class the a deeper look +at the comparison for the wave + + align:start position:0% +at the comparison for the wave + + + align:start position:0% +at the comparison for the wave +equation okay so see you tomorrow for + + align:start position:0% +equation okay so see you tomorrow for + + + align:start position:0% +equation okay so see you tomorrow for +difference equations for the for this + + align:start position:0% +difference equations for the for this + + + align:start position:0% +difference equations for the for this +problem + + align:start position:0% + + + + align:start position:0% + +thanks \ No newline at end of file diff --git a/ZaSMm2xvatw.txt b/ZaSMm2xvatw.txt new file mode 100644 index 0000000000000000000000000000000000000000..2477b90f70359531980930ea61dea5598e5f3bb2 --- /dev/null +++ b/ZaSMm2xvatw.txt @@ -0,0 +1,14867 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right you guys ready for + + align:start position:0% +ocw.mit.edu all right you guys ready for + + + align:start position:0% +ocw.mit.edu all right you guys ready for +some more hardness + + align:start position:0% +some more hardness + + + align:start position:0% +some more hardness +proofs Let's Do It um so today we start + + align:start position:0% +proofs Let's Do It um so today we start + + + align:start position:0% +proofs Let's Do It um so today we start +uh the universe of three + + align:start position:0% +uh the universe of three + + + align:start position:0% +uh the universe of three +partition and in general we're going to + + align:start position:0% +partition and in general we're going to + + + align:start position:0% +partition and in general we're going to +see uh + + align:start position:0% +see uh + + + align:start position:0% +see uh +today two plus + + align:start position:0% +today two plus + + + align:start position:0% +today two plus +problems uh which are useful for dealing + + align:start position:0% +problems uh which are useful for dealing + + + align:start position:0% +problems uh which are useful for dealing +with + + align:start position:0% + + + + align:start position:0% + +numbers uh + + align:start position:0% +numbers uh + + + align:start position:0% +numbers uh +for reducing + + align:start position:0% +for reducing + + + align:start position:0% +for reducing +to number problems numbers + + align:start position:0% +to number problems numbers + + + align:start position:0% +to number problems numbers +here um are going to be + + align:start position:0% +here um are going to be + + + align:start position:0% +here um are going to be +integers for the most + + align:start position:0% +integers for the most + + + align:start position:0% +integers for the most +part usually in complexity it's a lot + + align:start position:0% +part usually in complexity it's a lot + + + align:start position:0% +part usually in complexity it's a lot +easier to think of all your numbers + + align:start position:0% +easier to think of all your numbers + + + align:start position:0% +easier to think of all your numbers +being integers if they're not integers + + align:start position:0% +being integers if they're not integers + + + align:start position:0% +being integers if they're not integers +use fixed point or rationals and then + + align:start position:0% +use fixed point or rationals and then + + + align:start position:0% +use fixed point or rationals and then +they're basically integers um so we're + + align:start position:0% +they're basically integers um so we're + + + align:start position:0% +they're basically integers um so we're +going to talk my favorite is three + + align:start position:0% +going to talk my favorite is three + + + align:start position:0% +going to talk my favorite is three +partition and that will be pretty much + + align:start position:0% +partition and that will be pretty much + + + align:start position:0% +partition and that will be pretty much +all the proofs we'll do in the number + + align:start position:0% +all the proofs we'll do in the number + + + align:start position:0% +all the proofs we'll do in the number +context will be uh a reduction from + + align:start position:0% +context will be uh a reduction from + + + align:start position:0% +context will be uh a reduction from +three partition this is all about NP + + align:start position:0% +three partition this is all about NP + + + align:start position:0% +three partition this is all about NP +hardness I should say + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +but before we get to three partition I'm + + align:start position:0% +but before we get to three partition I'm + + + align:start position:0% +but before we get to three partition I'm +going to talk about another problem + + align:start position:0% +going to talk about another problem + + + align:start position:0% +going to talk about another problem +which is called two + + align:start position:0% + + + + align:start position:0% + +partition so two + + align:start position:0% + + + + align:start position:0% + +partition first I'll just have to Define + + align:start position:0% +partition first I'll just have to Define + + + align:start position:0% +partition first I'll just have to Define +all these problems which will take a + + align:start position:0% +all these problems which will take a + + + align:start position:0% +all these problems which will take a +little while then we'll get to all the + + align:start position:0% +little while then we'll get to all the + + + align:start position:0% +little while then we'll get to all the +fun reductions so in two partition + + align:start position:0% +fun reductions so in two partition + + + align:start position:0% +fun reductions so in two partition +you're given n + + align:start position:0% + + + + align:start position:0% + +integers uh we'll call this set of them + + align:start position:0% +integers uh we'll call this set of them + + + align:start position:0% +integers uh we'll call this set of them +capital A and we'll call the integers + + align:start position:0% +capital A and we'll call the integers + + + align:start position:0% +capital A and we'll call the integers +themselves little a sub I I from 1 to n + + align:start position:0% +themselves little a sub I I from 1 to n + + + align:start position:0% +themselves little a sub I I from 1 to n +let's + + align:start position:0% +let's + + + align:start position:0% +let's +say and what we'd like to do is + + align:start position:0% +say and what we'd like to do is + + + align:start position:0% +say and what we'd like to do is +partition them into two + + align:start position:0% + + + + align:start position:0% + +groups uh let's say A1 and + + align:start position:0% + + + + align:start position:0% + +A2 equals a uh of equal + + align:start position:0% +A2 equals a uh of equal + + + align:start position:0% +A2 equals a uh of equal +sum + + align:start position:0% + + + + align:start position:0% + +we want the sum of the integers in A1 to + + align:start position:0% +we want the sum of the integers in A1 to + + + align:start position:0% +we want the sum of the integers in A1 to +equal the sum of the integers in A2 uh + + align:start position:0% +equal the sum of the integers in A2 uh + + + align:start position:0% +equal the sum of the integers in A2 uh +and therefore they will equal 12 the + + align:start position:0% +and therefore they will equal 12 the + + + align:start position:0% +and therefore they will equal 12 the +total sum okay so we just want to decide + + align:start position:0% +total sum okay so we just want to decide + + + align:start position:0% +total sum okay so we just want to decide +binary choice for each number should It + + align:start position:0% +binary choice for each number should It + + + align:start position:0% +binary choice for each number should It +Go in A1 or A2 so this problem is NP + + align:start position:0% +Go in A1 or A2 so this problem is NP + + + align:start position:0% +Go in A1 or A2 so this problem is NP +hard and it's one of the original uh + + align:start position:0% +hard and it's one of the original uh + + + align:start position:0% +hard and it's one of the original uh +carp problems there's this famous paper + + align:start position:0% +carp problems there's this famous paper + + + align:start position:0% +carp problems there's this famous paper +by karp in 1972 that had before that + + align:start position:0% +by karp in 1972 that had before that + + + align:start position:0% +by karp in 1972 that had before that +there was a paper by cook that proved + + align:start position:0% +there was a paper by cook that proved + + + align:start position:0% +there was a paper by cook that proved +sat is MP complete and then karp wrote a + + align:start position:0% +sat is MP complete and then karp wrote a + + + align:start position:0% +sat is MP complete and then karp wrote a +paper with a zillion uh not literally + + align:start position:0% +paper with a zillion uh not literally + + + align:start position:0% +paper with a zillion uh not literally +but dozens of MP hardness proofs from + + align:start position:0% +but dozens of MP hardness proofs from + + + align:start position:0% +but dozens of MP hardness proofs from +sat to things like two partition I will + + align:start position:0% +sat to things like two partition I will + + + align:start position:0% +sat to things like two partition I will +not cover the proof here if you're + + align:start position:0% +not cover the proof here if you're + + + align:start position:0% +not cover the proof here if you're +interested in it read Gary and Johnson + + align:start position:0% +interested in it read Gary and Johnson + + + align:start position:0% +interested in it read Gary and Johnson +there's a nice coverage of it of this + + align:start position:0% +there's a nice coverage of it of this + + + align:start position:0% +there's a nice coverage of it of this +problem and all the problems we'll be + + align:start position:0% +problem and all the problems we'll be + + + align:start position:0% +problem and all the problems we'll be +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +today okay uh as a sideline I'll mention + + align:start position:0% +today okay uh as a sideline I'll mention + + + align:start position:0% +today okay uh as a sideline I'll mention +there's a + + align:start position:0% + + + + align:start position:0% + +generalization + + align:start position:0% +generalization + + + align:start position:0% +generalization +of this problem so it's also NP hard any + + align:start position:0% +of this problem so it's also NP hard any + + + align:start position:0% +of this problem so it's also NP hard any +generalization it's going to be even + + align:start position:0% +generalization it's going to be even + + + align:start position:0% +generalization it's going to be even +harder uh but it's useful to know about + + align:start position:0% +harder uh but it's useful to know about + + + align:start position:0% +harder uh but it's useful to know about +it's called subset sum occasionally it's + + align:start position:0% +it's called subset sum occasionally it's + + + align:start position:0% +it's called subset sum occasionally it's +easier to think about subset sum instead + + align:start position:0% +easier to think about subset sum instead + + + align:start position:0% +easier to think about subset sum instead +of partition although it's a + + align:start position:0% +of partition although it's a + + + align:start position:0% +of partition although it's a +generalization so if you can reduce from + + align:start position:0% +generalization so if you can reduce from + + + align:start position:0% +generalization so if you can reduce from +subset sum you can also reduce from + + align:start position:0% +subset sum you can also reduce from + + + align:start position:0% +subset sum you can also reduce from +partition um and here uh the setup is + + align:start position:0% +partition um and here uh the setup is + + + align:start position:0% +partition um and here uh the setup is +similar you're + + align:start position:0% +similar you're + + + align:start position:0% +similar you're +given uh and integers again just like + + align:start position:0% +given uh and integers again just like + + + align:start position:0% +given uh and integers again just like +before + + align:start position:0% +before + + + align:start position:0% +before +and you're given a Target sum this is + + align:start position:0% +and you're given a Target sum this is + + + align:start position:0% +and you're given a Target sum this is +one other integer we'll call the target + + align:start position:0% +one other integer we'll call the target + + + align:start position:0% +one other integer we'll call the target +sum T I'll also call this + + align:start position:0% +sum T I'll also call this + + + align:start position:0% +sum T I'll also call this +t uh and what we'd like to do is find a + + align:start position:0% +t uh and what we'd like to do is find a + + + align:start position:0% +t uh and what we'd like to do is find a +subset s of a uh whose sum is + + align:start position:0% + + + + align:start position:0% + +T okay this is a strict generalization + + align:start position:0% +T okay this is a strict generalization + + + align:start position:0% +T okay this is a strict generalization +here you're not given a number T but + + align:start position:0% +here you're not given a number T but + + + align:start position:0% +here you're not given a number T but +you're essentially choosing a subset + + align:start position:0% +you're essentially choosing a subset + + + align:start position:0% +you're essentially choosing a subset +A1 uh whose sum equals the sum of a over + + align:start position:0% +A1 uh whose sum equals the sum of a over + + + align:start position:0% +A1 uh whose sum equals the sum of a over +two so this is really just a particular + + align:start position:0% +two so this is really just a particular + + + align:start position:0% +two so this is really just a particular +choice of T this is the general case + + align:start position:0% +choice of T this is the general case + + + align:start position:0% +choice of T this is the general case +where you're given T so this is harder + + align:start position:0% +where you're given T so this is harder + + + align:start position:0% +where you're given T so this is harder +than that uh but it's worth knowing + + align:start position:0% +than that uh but it's worth knowing + + + align:start position:0% +than that uh but it's worth knowing +about in particular there's a problem + + align:start position:0% +about in particular there's a problem + + + align:start position:0% +about in particular there's a problem +set problem uh the problem set will be + + align:start position:0% +set problem uh the problem set will be + + + align:start position:0% +set problem uh the problem set will be +out in a couple of hours and it's a + + align:start position:0% +out in a couple of hours and it's a + + + align:start position:0% +out in a couple of hours and it's a +little easier to think about subset sum + + align:start position:0% +little easier to think about subset sum + + + align:start position:0% +little easier to think about subset sum +we think you don't have to + + align:start position:0% +we think you don't have to + + + align:start position:0% +we think you don't have to +but uh all right so let's go to + + align:start position:0% + + + + align:start position:0% + +three partition my favorite NP complete + + align:start position:0% +three partition my favorite NP complete + + + align:start position:0% +three partition my favorite NP complete +problem um + + align:start position:0% + + + + align:start position:0% + +so start is the + + align:start position:0% +so start is the + + + align:start position:0% +so start is the +same given integers A1 up to a + + align:start position:0% + + + + align:start position:0% + +n uh we're not given a Target sum what + + align:start position:0% +n uh we're not given a Target sum what + + + align:start position:0% +n uh we're not given a Target sum what +we'd like to do is partition + + align:start position:0% +we'd like to do is partition + + + align:start position:0% +we'd like to do is partition +them partition that set a + + align:start position:0% +them partition that set a + + + align:start position:0% +them partition that set a +into how many pieces three three nope n + + align:start position:0% +into how many pieces three three nope n + + + align:start position:0% +into how many pieces three three nope n +over + + align:start position:0% + + + + align:start position:0% + +three uh it's kind of like + + align:start position:0% +three uh it's kind of like + + + align:start position:0% +three uh it's kind of like +three not quite uh let's say sets uh + + align:start position:0% + + + + align:start position:0% + +A1 a n over 3 equals a I'm using a union + + align:start position:0% +A1 a n over 3 equals a I'm using a union + + + align:start position:0% +A1 a n over 3 equals a I'm using a union +with a DOT to indicate it's disjoint + + align:start position:0% +with a DOT to indicate it's disjoint + + + align:start position:0% +with a DOT to indicate it's disjoint +Union so these it's that's what a + + align:start position:0% +Union so these it's that's what a + + + align:start position:0% +Union so these it's that's what a +partition means that's redundant this is + + align:start position:0% +partition means that's redundant this is + + + align:start position:0% +partition means that's redundant this is +oldfashioned notation you probably + + align:start position:0% +oldfashioned notation you probably + + + align:start position:0% +oldfashioned notation you probably +haven't seen it but when I was growing + + align:start position:0% +haven't seen it but when I was growing + + + align:start position:0% +haven't seen it but when I was growing +up that was the notation of the day uh + + align:start position:0% +up that was the notation of the day uh + + + align:start position:0% +up that was the notation of the day uh +then we + + align:start position:0% +then we + + + align:start position:0% +then we +have + + align:start position:0% +have + + + align:start position:0% +have +right to n over three sets cool yeah + + align:start position:0% +right to n over three sets cool yeah + + + align:start position:0% +right to n over three sets cool yeah +assume n is divisible by three otherwise + + align:start position:0% +assume n is divisible by three otherwise + + + align:start position:0% +assume n is divisible by three otherwise +the answer is + + align:start position:0% +the answer is + + + align:start position:0% +the answer is +no okay and then which is the easy case + + align:start position:0% +no okay and then which is the easy case + + + align:start position:0% +no okay and then which is the easy case +uh of equal + + align:start position:0% + + + + align:start position:0% + +sum so we want the sum of each AI to be + + align:start position:0% +sum so we want the sum of each AI to be + + + align:start position:0% +sum so we want the sum of each AI to be +equal to T which is to the same thing + + align:start position:0% +equal to T which is to the same thing + + + align:start position:0% +equal to T which is to the same thing +which is going to be the sum of the A's + + align:start position:0% +which is going to be the sum of the A's + + + align:start position:0% +which is going to be the sum of the A's +divided by n + + align:start position:0% + + + + align:start position:0% + +over3 okay if this problem were about + + align:start position:0% +over3 okay if this problem were about + + + align:start position:0% +over3 okay if this problem were about +partitioning to three sets it would not + + align:start position:0% +partitioning to three sets it would not + + + align:start position:0% +partitioning to three sets it would not +be very interesting uh it would be + + align:start position:0% +be very interesting uh it would be + + + align:start position:0% +be very interesting uh it would be +basically identical to two partition + + align:start position:0% +basically identical to two partition + + + align:start position:0% +basically identical to two partition +with n over3 sets things are quite a bit + + align:start position:0% +with n over3 sets things are quite a bit + + + align:start position:0% +with n over3 sets things are quite a bit +different and we will get to that + + align:start position:0% +different and we will get to that + + + align:start position:0% +different and we will get to that +difference in a moment uh but first let + + align:start position:0% +difference in a moment uh but first let + + + align:start position:0% +difference in a moment uh but first let +me tell you about some fun facts about + + align:start position:0% +me tell you about some fun facts about + + + align:start position:0% +me tell you about some fun facts about +three part partion uh so we're + + align:start position:0% +three part partion uh so we're + + + align:start position:0% +three part partion uh so we're +partitioning into n over3 sets so you + + align:start position:0% +partitioning into n over3 sets so you + + + align:start position:0% +partitioning into n over3 sets so you +would expect on average most of the sets + + align:start position:0% +would expect on average most of the sets + + + align:start position:0% +would expect on average most of the sets +will have size three uh in fact you can + + align:start position:0% +will have size three uh in fact you can + + + align:start position:0% +will have size three uh in fact you can +make all of the sets have size exactly + + align:start position:0% +make all of the sets have size exactly + + + align:start position:0% +make all of the sets have size exactly +three because if you look at the + + align:start position:0% +three because if you look at the + + + align:start position:0% +three because if you look at the +reduction for this problem uh you + + align:start position:0% +reduction for this problem uh you + + + align:start position:0% +reduction for this problem uh you +can + + align:start position:0% +can + + + align:start position:0% +can +assume that each + + align:start position:0% +assume that each + + + align:start position:0% +assume that each +AI is uh between uh T over4 strictly + + align:start position:0% +AI is uh between uh T over4 strictly + + + align:start position:0% +AI is uh between uh T over4 strictly +between T over4 and T over2 + + align:start position:0% +between T over4 and T over2 + + + align:start position:0% +between T over4 and T over2 +okay if you have if you're going to have + + align:start position:0% +okay if you have if you're going to have + + + align:start position:0% +okay if you have if you're going to have +a set of numbers that sum to exactly + + align:start position:0% +a set of numbers that sum to exactly + + + align:start position:0% +a set of numbers that sum to exactly +T um and each of them is strictly bigger + + align:start position:0% +T um and each of them is strictly bigger + + + align:start position:0% +T um and each of them is strictly bigger +than T over4 then that means you can't + + align:start position:0% +than T over4 then that means you can't + + + align:start position:0% +than T over4 then that means you can't +have four of them because you would sum + + align:start position:0% +have four of them because you would sum + + + align:start position:0% +have four of them because you would sum +to too much and they're strictly less + + align:start position:0% +to too much and they're strictly less + + + align:start position:0% +to too much and they're strictly less +than T over2 then you can't just have + + align:start position:0% +than T over2 then you can't just have + + + align:start position:0% +than T over2 then you can't just have +two of them and hope to get to T so you + + align:start position:0% +two of them and hope to get to T so you + + + align:start position:0% +two of them and hope to get to T so you +have to have exactly three in every + + align:start position:0% + + + + align:start position:0% + +set you don't have to assume that and in + + align:start position:0% +set you don't have to assume that and in + + + align:start position:0% +set you don't have to assume that and in +some situations it's useful to just say + + align:start position:0% +some situations it's useful to just say + + + align:start position:0% +some situations it's useful to just say +well the AIS are some sets that sum to + + align:start position:0% +well the AIS are some sets that sum to + + + align:start position:0% +well the AIS are some sets that sum to +the right thing sometimes it's useful to + + align:start position:0% +the right thing sometimes it's useful to + + + align:start position:0% +the right thing sometimes it's useful to +assume that they are triples uh it's up + + align:start position:0% +assume that they are triples uh it's up + + + align:start position:0% +assume that they are triples uh it's up +to you what you consider that part of + + align:start position:0% +to you what you consider that part of + + + align:start position:0% +to you what you consider that part of +the problem statement to ask for the AI + + align:start position:0% +the problem statement to ask for the AI + + + align:start position:0% +the problem statement to ask for the AI +to have size three or not and it's + + align:start position:0% +to have size three or not and it's + + + align:start position:0% +to have size three or not and it's +useful to have both um in fact you can + + align:start position:0% +useful to have both um in fact you can + + + align:start position:0% +useful to have both um in fact you can +uh once you have this you can make all + + align:start position:0% +uh once you have this you can make all + + + align:start position:0% +uh once you have this you can make all +the AIS very very close to t + + align:start position:0% +the AIS very very close to t + + + align:start position:0% +the AIS very very close to t +over3 uh using a trick which we'll see a + + align:start position:0% +over3 uh using a trick which we'll see a + + + align:start position:0% +over3 uh using a trick which we'll see a +bunch of times today uh so let's say you + + align:start position:0% +bunch of times today uh so let's say you + + + align:start position:0% +bunch of times today uh so let's say you +could add I'll call it + + align:start position:0% +could add I'll call it + + + align:start position:0% +could add I'll call it +Infinity uh to each + + align:start position:0% + + + + align:start position:0% + +AI uh in that case of course any + + align:start position:0% +AI uh in that case of course any + + + align:start position:0% +AI uh in that case of course any +solution that you had before is still a + + align:start position:0% +solution that you had before is still a + + + align:start position:0% +solution that you had before is still a +solution uh just think of T is infinity + + align:start position:0% +solution uh just think of T is infinity + + + align:start position:0% +solution uh just think of T is infinity +is a really large number something like + + align:start position:0% +is a really large number something like + + + align:start position:0% +is a really large number something like +uh n^ the 100 times + + align:start position:0% +uh n^ the 100 times + + + align:start position:0% +uh n^ the 100 times +maximum uh item in a something like that + + align:start position:0% +maximum uh item in a something like that + + + align:start position:0% +maximum uh item in a something like that +that's a really maybe to the 100 power + + align:start position:0% +that's a really maybe to the 100 power + + + align:start position:0% +that's a really maybe to the 100 power +if you want but really big number uh + + align:start position:0% +if you want but really big number uh + + + align:start position:0% +if you want but really big number uh +this will Preserve of all solutions + + align:start position:0% +this will Preserve of all solutions + + + align:start position:0% +this will Preserve of all solutions +because all solutions every set has size + + align:start position:0% +because all solutions every set has size + + + align:start position:0% +because all solutions every set has size +exactly three so if you add three times + + align:start position:0% +exactly three so if you add three times + + + align:start position:0% +exactly three so if you add three times +infinity they'll still have the same + + align:start position:0% +infinity they'll still have the same + + + align:start position:0% +infinity they'll still have the same +sums and when you do that then most all + + align:start position:0% +sums and when you do that then most all + + + align:start position:0% +sums and when you do that then most all +the AIS are basically equal to each + + align:start position:0% +the AIS are basically equal to each + + + align:start position:0% +the AIS are basically equal to each +other which means they're roughly equal + + align:start position:0% +other which means they're roughly equal + + + align:start position:0% +other which means they're roughly equal +to T over3 um the the big the leading + + align:start position:0% +to T over3 um the the big the leading + + + align:start position:0% +to T over3 um the the big the leading +term is the same for everybody and then + + align:start position:0% +term is the same for everybody and then + + + align:start position:0% +term is the same for everybody and then +there's this little noise which was the + + align:start position:0% +there's this little noise which was the + + + align:start position:0% +there's this little noise which was the +original integer uh that you're adding + + align:start position:0% +original integer uh that you're adding + + + align:start position:0% +original integer uh that you're adding +on to uh that + + align:start position:0% +on to uh that + + + align:start position:0% +on to uh that +Infinity anyway so then all the ads are + + align:start position:0% +Infinity anyway so then all the ads are + + + align:start position:0% +Infinity anyway so then all the ads are +roughly T over3 + + align:start position:0% +roughly T over3 + + + align:start position:0% +roughly T over3 +cool + + align:start position:0% +cool + + + align:start position:0% +cool +let me tell you about a couple related + + align:start position:0% +let me tell you about a couple related + + + align:start position:0% +let me tell you about a couple related +problems to three partition and then + + align:start position:0% +problems to three partition and then + + + align:start position:0% +problems to three partition and then +I'll tell you why why we're talking even + + align:start position:0% +I'll tell you why why we're talking even + + + align:start position:0% +I'll tell you why why we're talking even +bothering to talk about two problems um + + align:start position:0% +bothering to talk about two problems um + + + align:start position:0% +bothering to talk about two problems um +instead of just + + align:start position:0% + + + + align:start position:0% + +one so uh next problem has a funny name + + align:start position:0% +one so uh next problem has a funny name + + + align:start position:0% +one so uh next problem has a funny name +especially when you don't know what + + align:start position:0% +especially when you don't know what + + + align:start position:0% +especially when you don't know what +three-dimensional matching is but we + + align:start position:0% +three-dimensional matching is but we + + + align:start position:0% +three-dimensional matching is but we +will get to that second don't worry + + align:start position:0% +will get to that second don't worry + + + align:start position:0% +will get to that second don't worry +about the name for the moment uh this is + + align:start position:0% +about the name for the moment uh this is + + + align:start position:0% +about the name for the moment uh this is +a closely related problem it's really uh + + align:start position:0% +a closely related problem it's really uh + + + align:start position:0% +a closely related problem it's really uh +a specialization of three + + align:start position:0% +a specialization of three + + + align:start position:0% +a specialization of three +partition uh but Okay so we've + + align:start position:0% + + + + align:start position:0% + +got in this case we're going to be given + + align:start position:0% +got in this case we're going to be given + + + align:start position:0% +got in this case we're going to be given +three sets of + + align:start position:0% + + + + align:start position:0% + +integers and what we'd like to do is I + + align:start position:0% +integers and what we'd like to do is I + + + align:start position:0% +integers and what we'd like to do is I +mean it's basically the same problem + + align:start position:0% +mean it's basically the same problem + + + align:start position:0% +mean it's basically the same problem +just think of taking the union of those + + align:start position:0% +just think of taking the union of those + + + align:start position:0% +just think of taking the union of those +sets but uh each of these sets that + + align:start position:0% +sets but uh each of these sets that + + + align:start position:0% +sets but uh each of these sets that +we're choosing the AIS should consist of + + align:start position:0% +we're choosing the AIS should consist of + + + align:start position:0% +we're choosing the AIS should consist of +one element from a one element from B + + align:start position:0% +one element from a one element from B + + + align:start position:0% +one element from a one element from B +one element from C so how did I + + align:start position:0% +one element from C so how did I + + + align:start position:0% +one element from C so how did I +formalize that say + + align:start position:0% + + + + align:start position:0% + +partition uh the + + align:start position:0% +partition uh the + + + align:start position:0% +partition uh the +union guess this a disjoint Union uh + + align:start position:0% + + + + align:start position:0% + +into and + + align:start position:0% + + + + align:start position:0% + +triples + + align:start position:0% +triples + + + align:start position:0% +triples +si + + align:start position:0% +si + + + align:start position:0% +si +uh and cross product + + align:start position:0% +uh and cross product + + + align:start position:0% +uh and cross product +ABC so you're choosing one from each of + + align:start position:0% +ABC so you're choosing one from each of + + + align:start position:0% +ABC so you're choosing one from each of +these guys in each SI and they should be + + align:start position:0% +these guys in each SI and they should be + + + align:start position:0% +these guys in each SI and they should be +of equal + + align:start position:0% + + + + align:start position:0% + +sum and so the sum will be sum of a plus + + align:start position:0% +sum and so the sum will be sum of a plus + + + align:start position:0% +sum and so the sum will be sum of a plus +the sum of B plus sum of C / + + align:start position:0% +the sum of B plus sum of C / + + + align:start position:0% +the sum of B plus sum of C / +by n + + align:start position:0% +by n + + + align:start position:0% +by n +I think because there's three of + + align:start position:0% + + + + align:start position:0% + +them cool okay so almost the same + + align:start position:0% +them cool okay so almost the same + + + align:start position:0% +them cool okay so almost the same +problem I just changed what n was by a + + align:start position:0% +problem I just changed what n was by a + + + align:start position:0% +problem I just changed what n was by a +factor of three that's why there's n + + align:start position:0% +factor of three that's why there's n + + + align:start position:0% +factor of three that's why there's n +over three here and an N here um but + + align:start position:0% +over three here and an N here um but + + + align:start position:0% +over three here and an N here um but +here we're specializing in a sense to + + align:start position:0% +here we're specializing in a sense to + + + align:start position:0% +here we're specializing in a sense to +say that uh we we can we're giving + + align:start position:0% +say that uh we we can we're giving + + + align:start position:0% +say that uh we we can we're giving +different types of numbers the red + + align:start position:0% +different types of numbers the red + + + align:start position:0% +different types of numbers the red +integers the green integers and the blue + + align:start position:0% +integers the green integers and the blue + + + align:start position:0% +integers the green integers and the blue +integers you have to choose one of each + + align:start position:0% +integers you have to choose one of each + + + align:start position:0% +integers you have to choose one of each +color okay uh for fun + + align:start position:0% +color okay uh for fun + + + align:start position:0% +color okay uh for fun +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +let me show you why this problem is uh + + align:start position:0% +let me show you why this problem is uh + + + align:start position:0% +let me show you why this problem is uh +in some sense + + align:start position:0% + + + + align:start position:0% + +simpler this also gives you a useful + + align:start position:0% +simpler this also gives you a useful + + + align:start position:0% +simpler this also gives you a useful +kind of technique for playing with these + + align:start position:0% +kind of technique for playing with these + + + align:start position:0% +kind of technique for playing with these +number problems uh so I want to reduce + + align:start position:0% +number problems uh so I want to reduce + + + align:start position:0% +number problems uh so I want to reduce +from this numerical threedimensional + + align:start position:0% +from this numerical threedimensional + + + align:start position:0% +from this numerical threedimensional +matching problem which you might also + + align:start position:0% +matching problem which you might also + + + align:start position:0% +matching problem which you might also +call the ABC version of three part I and + + align:start position:0% +call the ABC version of three part I and + + + align:start position:0% +call the ABC version of three part I and +we reduce it to three partition so I'm + + align:start position:0% +we reduce it to three partition so I'm + + + align:start position:0% +we reduce it to three partition so I'm +given an instance these numbers and I + + align:start position:0% +given an instance these numbers and I + + + align:start position:0% +given an instance these numbers and I +want to somehow + + align:start position:0% +want to somehow + + + align:start position:0% +want to somehow +Force so the basic idea is to take these + + align:start position:0% +Force so the basic idea is to take these + + + align:start position:0% +Force so the basic idea is to take these +numbers and just throw them into one big + + align:start position:0% +numbers and just throw them into one big + + + align:start position:0% +numbers and just throw them into one big +set a prime uh but I want to force uh + + align:start position:0% +set a prime uh but I want to force uh + + + align:start position:0% +set a prime uh but I want to force uh +this ABC property that I choose one from + + align:start position:0% +this ABC property that I choose one from + + + align:start position:0% +this ABC property that I choose one from +each uh maybe any suggestions how yeah + + align:start position:0% +each uh maybe any suggestions how yeah + + + align:start position:0% +each uh maybe any suggestions how yeah +well I just have a question we Define + + align:start position:0% +well I just have a question we Define + + + align:start position:0% +well I just have a question we Define +these all as sets you can't have + + align:start position:0% +these all as sets you can't have + + + align:start position:0% +these all as sets you can't have +duplicates uh I didn't say the word set + + align:start position:0% +duplicates uh I didn't say the word set + + + align:start position:0% +duplicates uh I didn't say the word set +I actually meant + + align:start position:0% +I actually meant + + + align:start position:0% +I actually meant +multiset yeah so + + align:start position:0% +multiset yeah so + + + align:start position:0% +multiset yeah so +this is a multiset good + + align:start position:0% +this is a multiset good + + + align:start position:0% +this is a multiset good +question all of them are multisets so it + + align:start position:0% +question all of them are multisets so it + + + align:start position:0% +question all of them are multisets so it +makes the notion of destroy a little bit + + align:start position:0% +makes the notion of destroy a little bit + + + align:start position:0% +makes the notion of destroy a little bit +weird but you know what I + + align:start position:0% +weird but you know what I + + + align:start position:0% +weird but you know what I +mean what yeah uh could you add a really + + align:start position:0% +mean what yeah uh could you add a really + + + align:start position:0% +mean what yeah uh could you add a really +big number to all the these and twice + + align:start position:0% +big number to all the these and twice + + + align:start position:0% +big number to all the these and twice +that really big number to all the C's + + align:start position:0% +that really big number to all the C's + + + align:start position:0% +that really big number to all the C's +Okay add a I hadn't thought about this + + align:start position:0% +Okay add a I hadn't thought about this + + + align:start position:0% +Okay add a I hadn't thought about this +so add a really big number to all the + + align:start position:0% +so add a really big number to all the + + + align:start position:0% +so add a really big number to all the +B's and then twice that big number to + + align:start position:0% +B's and then twice that big number to + + + align:start position:0% +B's and then twice that big number to +all the + + align:start position:0% + + + + align:start position:0% + +C's and then the target sum would be + + align:start position:0% +C's and then the target sum would be + + + align:start position:0% +C's and then the target sum would be +three times the big number + + align:start position:0% +three times the big number + + + align:start position:0% +three times the big number +plus sorry said make it like three + + align:start position:0% +plus sorry said make it like three + + + align:start position:0% +plus sorry said make it like three +instead so you can't do like three + + align:start position:0% +instead so you can't do like three + + + align:start position:0% +instead so you can't do like three +things from yeah right so you don't want + + align:start position:0% +things from yeah right so you don't want + + + align:start position:0% +things from yeah right so you don't want +you don't want to take two two B's and + + align:start position:0% +you don't want to take two two B's and + + + align:start position:0% +you don't want to take two two B's and +then that looks like a c uh so maybe you + + align:start position:0% +then that looks like a c uh so maybe you + + + align:start position:0% +then that looks like a c uh so maybe you +want + + align:start position:0% +want + + + align:start position:0% +want +uh three times a big number here and six + + align:start position:0% +uh three times a big number here and six + + + align:start position:0% +uh three times a big number here and six +times a big or nine times a big number + + align:start position:0% +times a big or nine times a big number + + + align:start position:0% +times a big or nine times a big number +here something like that I think + + align:start position:0% +here something like that I think + + + align:start position:0% +here something like that I think +actually one times a big number and + + align:start position:0% +actually one times a big number and + + + align:start position:0% +actually one times a big number and +three times a big number would do it + + align:start position:0% +three times a big number would do it + + + align:start position:0% +three times a big number would do it +yeah cool so uh the way I did it in the + + align:start position:0% +yeah cool so uh the way I did it in the + + + align:start position:0% +yeah cool so uh the way I did it in the +notes was adding a small number but + + align:start position:0% +notes was adding a small number but + + + align:start position:0% +notes was adding a small number but +either way works let's let's do it with + + align:start position:0% +either way works let's let's do it with + + + align:start position:0% +either way works let's let's do it with +the big number cuz that's fun uh so + + align:start position:0% +the big number cuz that's fun uh so + + + align:start position:0% +the big number cuz that's fun uh so +we're going to take + + align:start position:0% +we're going to take + + + align:start position:0% +we're going to take +um okay so we will construct I'll call + + align:start position:0% +um okay so we will construct I'll call + + + align:start position:0% +um okay so we will construct I'll call +it a + + align:start position:0% +it a + + + align:start position:0% +it a +prime to consist + + align:start position:0% +prime to consist + + + align:start position:0% +prime to consist +of uh a for all little a in big a and + + align:start position:0% +of uh a for all little a in big a and + + + align:start position:0% +of uh a for all little a in big a and +then we'll say a Plus usually big number + + align:start position:0% +then we'll say a Plus usually big number + + + align:start position:0% +then we'll say a Plus usually big number +I write with a capital B but that's not + + align:start position:0% +I write with a capital B but that's not + + + align:start position:0% +I write with a capital B but that's not +very good because we already have a + + align:start position:0% +very good because we already have a + + + align:start position:0% +very good because we already have a +couple B so call it X + + align:start position:0% +couple B so call it X + + + align:start position:0% +couple B so call it X +uh or I should call it Infinity for + + align:start position:0% +uh or I should call it Infinity for + + + align:start position:0% +uh or I should call it Infinity for +consistency right so for each B and B I + + align:start position:0% +consistency right so for each B and B I + + + align:start position:0% +consistency right so for each B and B I +will add infinity to it and then + + align:start position:0% +will add infinity to it and then + + + align:start position:0% +will add infinity to it and then +C um is going to be let say three times + + align:start position:0% +C um is going to be let say three times + + + align:start position:0% +C um is going to be let say three times +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +in let's do four times infinity it makes + + align:start position:0% +in let's do four times infinity it makes + + + align:start position:0% +in let's do four times infinity it makes +me feel a little safer somehow because + + align:start position:0% +me feel a little safer somehow because + + + align:start position:0% +me feel a little safer somehow because +but we're constructing a set of size + + align:start position:0% +but we're constructing a set of size + + + align:start position:0% +but we're constructing a set of size +three so if you take three of these I + + align:start position:0% +three so if you take three of these I + + + align:start position:0% +three so if you take three of these I +wor that looks like a c that's not + + align:start position:0% +wor that looks like a c that's not + + + align:start position:0% +wor that looks like a c that's not +enough but we'll be + + align:start position:0% +enough but we'll be + + + align:start position:0% +enough but we'll be +safe why not we can choose pretty big + + align:start position:0% +safe why not we can choose pretty big + + + align:start position:0% +safe why not we can choose pretty big +numbers here uh so + + align:start position:0% +numbers here uh so + + + align:start position:0% +numbers here uh so +happy + + align:start position:0% +happy + + + align:start position:0% +happy +no you might be able to do multiple A's + + align:start position:0% +no you might be able to do multiple A's + + + align:start position:0% +no you might be able to do multiple A's +in a single set um if they're + + align:start position:0% +in a single set um if they're + + + align:start position:0% +in a single set um if they're +sufficiently small because they're + + align:start position:0% +sufficiently small because they're + + + align:start position:0% +sufficiently small because they're +not yeah okay okay A's are a problem you + + align:start position:0% +not yeah okay okay A's are a problem you + + + align:start position:0% +not yeah okay okay A's are a problem you +could maybe do more than three total so + + align:start position:0% +could maybe do more than three total so + + + align:start position:0% +could maybe do more than three total so +let's do one + + align:start position:0% +let's do one + + + align:start position:0% +let's do one +Infinity then let me get a proper + + align:start position:0% +Infinity then let me get a proper + + + align:start position:0% +Infinity then let me get a proper +eraser good thing we have Sarah here to + + align:start position:0% +eraser good thing we have Sarah here to + + + align:start position:0% +eraser good thing we have Sarah here to +correct our + + align:start position:0% +correct our + + + align:start position:0% +correct our +proofs um 3 + + align:start position:0% +proofs um 3 + + + align:start position:0% +proofs um 3 +Infinity + + align:start position:0% + + + + align:start position:0% + +9 six would be bad because then two of + + align:start position:0% +9 six would be bad because then two of + + + align:start position:0% +9 six would be bad because then two of +these would be one of + + align:start position:0% + + + + align:start position:0% + +those right so uh this means the new + + align:start position:0% +those right so uh this means the new + + + align:start position:0% +those right so uh this means the new +Target sum should be uh the old Target + + align:start position:0% +Target sum should be uh the old Target + + + align:start position:0% +Target sum should be uh the old Target +sum which was the sum of these divided + + align:start position:0% +sum which was the sum of these divided + + + align:start position:0% +sum which was the sum of these divided +by n Plus + + align:start position:0% +by n Plus + + + align:start position:0% +by n Plus +plus 13 + + align:start position:0% + + + + align:start position:0% + +infinity infinity a function of NS uh + + align:start position:0% +infinity infinity a function of NS uh + + + align:start position:0% +infinity infinity a function of NS uh +infinity I should Define let's make it + + align:start position:0% +infinity I should Define let's make it + + + align:start position:0% +infinity I should Define let's make it +uh I think just like 10 times Max of a + + align:start position:0% +uh I think just like 10 times Max of a + + + align:start position:0% +uh I think just like 10 times Max of a +how to do + + align:start position:0% +how to do + + + align:start position:0% +how to do +it you you could be it as a function of + + align:start position:0% +it you you could be it as a function of + + + align:start position:0% +it you you could be it as a function of +N I don't think that's necessary here + + align:start position:0% +N I don't think that's necessary here + + + align:start position:0% +N I don't think that's necessary here +because all of our sets are of size + + align:start position:0% +because all of our sets are of size + + + align:start position:0% +because all of our sets are of size +three but if you're doing something like + + align:start position:0% +three but if you're doing something like + + + align:start position:0% +three but if you're doing something like +this for two partition you'd want to + + align:start position:0% +this for two partition you'd want to + + + align:start position:0% +this for two partition you'd want to +multiply by n or n squ this is a common + + align:start position:0% +multiply by n or n squ this is a common + + + align:start position:0% +multiply by n or n squ this is a common +trick uh to do this kind of scaling or + + align:start position:0% +trick uh to do this kind of scaling or + + + align:start position:0% +trick uh to do this kind of scaling or +offsets or things like that uh instead + + align:start position:0% +offsets or things like that uh instead + + + align:start position:0% +offsets or things like that uh instead +of infinity here you could write Epsilon + + align:start position:0% +of infinity here you could write Epsilon + + + align:start position:0% +of infinity here you could write Epsilon +where Epsilon is much smaller than one I + + align:start position:0% +where Epsilon is much smaller than one I + + + align:start position:0% +where Epsilon is much smaller than one I +think that would also work and that's + + align:start position:0% +think that would also work and that's + + + align:start position:0% +think that would also work and that's +what's done make it the max of the um a + + align:start position:0% +what's done make it the max of the um a + + + align:start position:0% +what's done make it the max of the um a +as opposed to a prime whoops uh this + + align:start position:0% +as opposed to a prime whoops uh this + + + align:start position:0% +as opposed to a prime whoops uh this +should probably be Max of + + align:start position:0% + + + + align:start position:0% + +ABC uh yeah you can't make it Max of a + + align:start position:0% +ABC uh yeah you can't make it Max of a + + + align:start position:0% +ABC uh yeah you can't make it Max of a +prime that would be cyclic then Infinity + + align:start position:0% +prime that would be cyclic then Infinity + + + align:start position:0% +prime that would be cyclic then Infinity +would actually be infinite + + align:start position:0% +would actually be infinite + + + align:start position:0% +would actually be infinite +yeah good so I think that works there + + align:start position:0% +yeah good so I think that works there + + + align:start position:0% +yeah good so I think that works there +are things to check here obviously we + + align:start position:0% +are things to check here obviously we + + + align:start position:0% +are things to check here obviously we +need to check that uh whenever we have a + + align:start position:0% +need to check that uh whenever we have a + + + align:start position:0% +need to check that uh whenever we have a +solution to the original instance we + + align:start position:0% +solution to the original instance we + + + align:start position:0% +solution to the original instance we +have a solution to this instance that's + + align:start position:0% +have a solution to this instance that's + + + align:start position:0% +have a solution to this instance that's +pretty clear you just take the same + + align:start position:0% +pretty clear you just take the same + + + align:start position:0% +pretty clear you just take the same +choices of the AI bis and CIS uh and the + + align:start position:0% +choices of the AI bis and CIS uh and the + + + align:start position:0% +choices of the AI bis and CIS uh and the +Infinities will always add up to 13 uh + + align:start position:0% +Infinities will always add up to 13 uh + + + align:start position:0% +Infinities will always add up to 13 uh +the tricky part is to show that if you + + align:start position:0% +the tricky part is to show that if you + + + align:start position:0% +the tricky part is to show that if you +have a solution to this three partition + + align:start position:0% +have a solution to this three partition + + + align:start position:0% +have a solution to this three partition +instance you can convert that back into + + align:start position:0% +instance you can convert that back into + + + align:start position:0% +instance you can convert that back into +a solution to the numerical + + align:start position:0% +a solution to the numerical + + + align:start position:0% +a solution to the numerical +threedimensional matching instance and + + align:start position:0% +threedimensional matching instance and + + + align:start position:0% +threedimensional matching instance and +that's where you essentially want show + + align:start position:0% +that's where you essentially want show + + + align:start position:0% +that's where you essentially want show +that the Infinities can be treated + + align:start position:0% +that the Infinities can be treated + + + align:start position:0% +that the Infinities can be treated +algebraically because they're so huge + + align:start position:0% +algebraically because they're so huge + + + align:start position:0% +algebraically because they're so huge +you can never construct an Infinity in + + align:start position:0% +you can never construct an Infinity in + + + align:start position:0% +you can never construct an Infinity in +another + + align:start position:0% +another + + + align:start position:0% +another +way uh so but I'll leave that as an + + align:start position:0% +way uh so but I'll leave that as an + + + align:start position:0% +way uh so but I'll leave that as an +exercise to actually prove because we're + + align:start position:0% +exercise to actually prove because we're + + + align:start position:0% +exercise to actually prove because we're +not really going to use this problem too + + align:start position:0% +not really going to use this problem too + + + align:start position:0% +not really going to use this problem too +much you're welcome to maybe on problem + + align:start position:0% +much you're welcome to maybe on problem + + + align:start position:0% +much you're welcome to maybe on problem +sets maybe in open problems it would be + + align:start position:0% +sets maybe in open problems it would be + + + align:start position:0% +sets maybe in open problems it would be +good but uh most of the time I would say + + align:start position:0% +good but uh most of the time I would say + + + align:start position:0% +good but uh most of the time I would say +we use three partition I want you to + + align:start position:0% +we use three partition I want you to + + + align:start position:0% +we use three partition I want you to +know about this in particular because + + align:start position:0% +know about this in particular because + + + align:start position:0% +know about this in particular because +it's related to another problem which is + + align:start position:0% +it's related to another problem which is + + + align:start position:0% +it's related to another problem which is +called threedimensional + + align:start position:0% + + + + align:start position:0% + +matching + + align:start position:0% + + + + align:start position:0% + +yes is the assumption that the uh AI is + + align:start position:0% +yes is the assumption that the uh AI is + + + align:start position:0% +yes is the assumption that the uh AI is +all cardinality 3 built into the problem + + align:start position:0% +all cardinality 3 built into the problem + + + align:start position:0% +all cardinality 3 built into the problem +specification here you get a choice you + + align:start position:0% +specification here you get a choice you + + + align:start position:0% +specification here you get a choice you +can either make this part of the problem + + align:start position:0% +can either make this part of the problem + + + align:start position:0% +can either make this part of the problem +specification or not it won't matter + + align:start position:0% +specification or not it won't matter + + + align:start position:0% +specification or not it won't matter +okay well I think in this case if you + + align:start position:0% +okay well I think in this case if you + + + align:start position:0% +okay well I think in this case if you +don't build it into the problem spe can + + align:start position:0% +don't build it into the problem spe can + + + align:start position:0% +don't build it into the problem spe can +you take 12 A's or something uh and then + + align:start position:0% +you take 12 A's or something uh and then + + + align:start position:0% +you take 12 A's or something uh and then +you get 12 Infinities and then they add + + align:start position:0% +you get 12 Infinities and then they add + + + align:start position:0% +you get 12 Infinities and then they add +up to another Infinity yes we definitely + + align:start position:0% +up to another Infinity yes we definitely + + + align:start position:0% +up to another Infinity yes we definitely +want to take this as part of the + + align:start position:0% +want to take this as part of the + + + align:start position:0% +want to take this as part of the +specification for this reduction yeah + + align:start position:0% +specification for this reduction yeah + + + align:start position:0% +specification for this reduction yeah +good point + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so here's a problem uh you've probably + + align:start position:0% +so here's a problem uh you've probably + + + align:start position:0% +so here's a problem uh you've probably +heard of the matching problem matching + + align:start position:0% +heard of the matching problem matching + + + align:start position:0% +heard of the matching problem matching +problem let's say the perfect matching + + align:start position:0% +problem let's say the perfect matching + + + align:start position:0% +problem let's say the perfect matching +problem is you're given a graph and you + + align:start position:0% +problem is you're given a graph and you + + + align:start position:0% +problem is you're given a graph and you +want to find a set of edges which are + + align:start position:0% +want to find a set of edges which are + + + align:start position:0% +want to find a set of edges which are +disjoint meaning no two edges share a + + align:start position:0% +disjoint meaning no two edges share a + + + align:start position:0% +disjoint meaning no two edges share a +Vertex uh that covers all the vertices + + align:start position:0% +Vertex uh that covers all the vertices + + + align:start position:0% +Vertex uh that covers all the vertices +so if you have n vertices you'd like to + + align:start position:0% +so if you have n vertices you'd like to + + + align:start position:0% +so if you have n vertices you'd like to +find n over two edges that are disjoint + + align:start position:0% +find n over two edges that are disjoint + + + align:start position:0% +find n over two edges that are disjoint +from each other that's perfect matching + + align:start position:0% +from each other that's perfect matching + + + align:start position:0% +from each other that's perfect matching +you might call it two-dimensional + + align:start position:0% +you might call it two-dimensional + + + align:start position:0% +you might call it two-dimensional +matching because an edge has two ends + + align:start position:0% +matching because an edge has two ends + + + align:start position:0% +matching because an edge has two ends +three dimensional matching takes place + + align:start position:0% +three dimensional matching takes place + + + align:start position:0% +three dimensional matching takes place +in a hyper graph and in this case it's + + align:start position:0% +in a hyper graph and in this case it's + + + align:start position:0% +in a hyper graph and in this case it's +going to be a hyp + + align:start position:0% +going to be a hyp + + + align:start position:0% +going to be a hyp +um a tri partite + + align:start position:0% + + + + align:start position:0% + +hypergraph you may not have seen hyper + + align:start position:0% +hypergraph you may not have seen hyper + + + align:start position:0% +hypergraph you may not have seen hyper +graphs before they're just like graphs + + align:start position:0% +graphs before they're just like graphs + + + align:start position:0% +graphs before they're just like graphs +but edges can have more than two end + + align:start position:0% +but edges can have more than two end + + + align:start position:0% +but edges can have more than two end +points in this case they will have + + align:start position:0% +points in this case they will have + + + align:start position:0% +points in this case they will have +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +three um so let's say the + + align:start position:0% +three um so let's say the + + + align:start position:0% +three um so let's say the +vertices are a distraint union B + + align:start position:0% +vertices are a distraint union B + + + align:start position:0% +vertices are a distraint union B +distraint Union + + align:start position:0% +distraint Union + + + align:start position:0% +distraint Union +C and let's say they all have size + + align:start position:0% + + + + align:start position:0% + +n and the hyper + + align:start position:0% + + + + align:start position:0% + +edges + + align:start position:0% + + + + align:start position:0% + +e okay so this is uh maybe it's worth + + align:start position:0% +e okay so this is uh maybe it's worth + + + align:start position:0% +e okay so this is uh maybe it's worth +drawing a picture + + align:start position:0% + + + + align:start position:0% + +so you have uh the set a set B I guess + + align:start position:0% +so you have uh the set a set B I guess + + + align:start position:0% +so you have uh the set a set B I guess +they're all the same + + align:start position:0% +they're all the same + + + align:start position:0% +they're all the same +size set + + align:start position:0% +size set + + + align:start position:0% +size set +C and an edge might look like this or + + align:start position:0% +C and an edge might look like this or + + + align:start position:0% +C and an edge might look like this or +like this or so on okay those are you + + align:start position:0% +like this or so on okay those are you + + + align:start position:0% +like this or so on okay those are you +take one from each and then your goal is + + align:start position:0% +take one from each and then your goal is + + + align:start position:0% +take one from each and then your goal is +to find uh n + + align:start position:0% +to find uh n + + + align:start position:0% +to find uh n +over3 sorry n disjoint + + align:start position:0% + + + + align:start position:0% + +edges if you find that many and they're + + align:start position:0% +edges if you find that many and they're + + + align:start position:0% +edges if you find that many and they're +disjoint that means they will cover all + + align:start position:0% +disjoint that means they will cover all + + + align:start position:0% +disjoint that means they will cover all +of the vertices every vertex will be hit + + align:start position:0% +of the vertices every vertex will be hit + + + align:start position:0% +of the vertices every vertex will be hit +by exactly one Edge hyper + + align:start position:0% + + + + align:start position:0% + +Edge okay so this is the + + align:start position:0% +Edge okay so this is the + + + align:start position:0% +Edge okay so this is the +three-dimensional version of bipartite + + align:start position:0% +three-dimensional version of bipartite + + + align:start position:0% +three-dimensional version of bipartite +matching I guess there's also a + + align:start position:0% +matching I guess there's also a + + + align:start position:0% +matching I guess there's also a +non-bipartite version for extra + + align:start position:0% +non-bipartite version for extra + + + align:start position:0% +non-bipartite version for extra +completeness there's something called + + align:start position:0% +completeness there's something called + + + align:start position:0% +completeness there's something called +exact cover by three sets + + align:start position:0% + + + + align:start position:0% + +three meaning the cardinality this is + + align:start position:0% +three meaning the cardinality this is + + + align:start position:0% +three meaning the cardinality this is +called x3c you do see uh 3dm and x33 + + align:start position:0% +called x3c you do see uh 3dm and x33 + + + align:start position:0% +called x3c you do see uh 3dm and x33 +frequently in the literature and + + align:start position:0% +frequently in the literature and + + + align:start position:0% +frequently in the literature and +especially in Gary and Johnson so + + align:start position:0% +especially in Gary and Johnson so + + + align:start position:0% +especially in Gary and Johnson so +they're good problems to know about uh + + align:start position:0% +they're good problems to know about uh + + + align:start position:0% +they're good problems to know about uh +here it's sort of the generalized + + align:start position:0% +here it's sort of the generalized + + + align:start position:0% +here it's sort of the generalized +version where you're given uh non + + align:start position:0% +version where you're given uh non + + + align:start position:0% +version where you're given uh non +tripartite just a uh three + + align:start position:0% +tripartite just a uh three + + + align:start position:0% +tripartite just a uh three +uniform hypergraph three uniform just + + align:start position:0% +uniform hypergraph three uniform just + + + align:start position:0% +uniform hypergraph three uniform just +means every Edge has cardinality + + align:start position:0% + + + + align:start position:0% + +three and your goal is to + + align:start position:0% +three and your goal is to + + + align:start position:0% +three and your goal is to +find uh let's say it has n + + align:start position:0% + + + + align:start position:0% + +vertices uh + + align:start position:0% +vertices uh + + + align:start position:0% +vertices uh +find uh n over3 disjoint hyperedges + + align:start position:0% + + + + align:start position:0% + +okay okay many times the almost same + + align:start position:0% +okay okay many times the almost same + + + align:start position:0% +okay okay many times the almost same +problem uh how do these relate well uh + + align:start position:0% +problem uh how do these relate well uh + + + align:start position:0% +problem uh how do these relate well uh +certainly if you take a numerical + + align:start position:0% +certainly if you take a numerical + + + align:start position:0% +certainly if you take a numerical +threedimensional matching problem that + + align:start position:0% +threedimensional matching problem that + + + align:start position:0% +threedimensional matching problem that +is a three-dimensional matching problem + + align:start position:0% +is a three-dimensional matching problem + + + align:start position:0% +is a three-dimensional matching problem +you can convert it into a graph like + + align:start position:0% +you can convert it into a graph like + + + align:start position:0% +you can convert it into a graph like +this uh you're just forgetting the fact + + align:start position:0% +this uh you're just forgetting the fact + + + align:start position:0% +this uh you're just forgetting the fact +that there's numbers but then when you + + align:start position:0% +that there's numbers but then when you + + + align:start position:0% +that there's numbers but then when you +draw the edge you draw one of these + + align:start position:0% +draw the edge you draw one of these + + + align:start position:0% +draw the edge you draw one of these +hyper edges exactly when uh AI plus bi + + align:start position:0% +hyper edges exactly when uh AI plus bi + + + align:start position:0% +hyper edges exactly when uh AI plus bi +plus c i equals the target sum okay so + + align:start position:0% +plus c i equals the target sum okay so + + + align:start position:0% +plus c i equals the target sum okay so +numerical threedimensional matching is a + + align:start position:0% +numerical threedimensional matching is a + + + align:start position:0% +numerical threedimensional matching is a +special case of threedimensional + + align:start position:0% +special case of threedimensional + + + align:start position:0% +special case of threedimensional +matching occasionally it's useful to + + align:start position:0% +matching occasionally it's useful to + + + align:start position:0% +matching occasionally it's useful to +start from threedimensional matching not + + align:start position:0% +start from threedimensional matching not + + + align:start position:0% +start from threedimensional matching not +for number problems though if you have a + + align:start position:0% +for number problems though if you have a + + + align:start position:0% +for number problems though if you have a +number problem you like the numerical + + align:start position:0% +number problem you like the numerical + + + align:start position:0% +number problem you like the numerical +version uh personally I prefer three + + align:start position:0% +version uh personally I prefer three + + + align:start position:0% +version uh personally I prefer three +partition but these two are pretty close + + align:start position:0% +partition but these two are pretty close + + + align:start position:0% +partition but these two are pretty close +uh we saw one connection between them + + align:start position:0% +uh we saw one connection between them + + + align:start position:0% +uh we saw one connection between them +hiac cover by three sets is in some + + align:start position:0% +hiac cover by three sets is in some + + + align:start position:0% +hiac cover by three sets is in some +sense even more General than + + align:start position:0% +sense even more General than + + + align:start position:0% +sense even more General than +three-dimensional + + align:start position:0% +three-dimensional + + + align:start position:0% +three-dimensional +matching + + align:start position:0% +matching + + + align:start position:0% +matching +uh yeah it is more + + align:start position:0% +uh yeah it is more + + + align:start position:0% +uh yeah it is more +General because tripartite hypergraph + + align:start position:0% +General because tripartite hypergraph + + + align:start position:0% +General because tripartite hypergraph +like this is uniform so this is a strict + + align:start position:0% +like this is uniform so this is a strict + + + align:start position:0% +like this is uniform so this is a strict +generalization of that but they all + + align:start position:0% +generalization of that but they all + + + align:start position:0% +generalization of that but they all +appear somewhat so that it would be good + + align:start position:0% +appear somewhat so that it would be good + + + align:start position:0% +appear somewhat so that it would be good +for you to know about them again three + + align:start position:0% +for you to know about them again three + + + align:start position:0% +for you to know about them again three +partition is where is where the action + + align:start position:0% +partition is where is where the action + + + align:start position:0% +partition is where is where the action +is all right let me go back to this + + align:start position:0% +is all right let me go back to this + + + align:start position:0% +is all right let me go back to this +issue of two + + align:start position:0% +issue of two + + + align:start position:0% +issue of two +partition versus three partition these + + align:start position:0% +partition versus three partition these + + + align:start position:0% +partition versus three partition these +are the two main problems I want to talk + + align:start position:0% +are the two main problems I want to talk + + + align:start position:0% +are the two main problems I want to talk +about um + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +they relate to an important distinction + + align:start position:0% +they relate to an important distinction + + + align:start position:0% +they relate to an important distinction +in NP hardness which is weak versus + + align:start position:0% +in NP hardness which is weak versus + + + align:start position:0% +in NP hardness which is weak versus +strong NP hardness so there are two + + align:start position:0% +strong NP hardness so there are two + + + align:start position:0% +strong NP hardness so there are two +types of NP + + align:start position:0% +types of NP + + + align:start position:0% +types of NP +hardness for number + + align:start position:0% +hardness for number + + + align:start position:0% +hardness for number +problems if your input is a graph these + + align:start position:0% +problems if your input is a graph these + + + align:start position:0% +problems if your input is a graph these +two Notions are the same so you don't + + align:start position:0% +two Notions are the same so you don't + + + align:start position:0% +two Notions are the same so you don't +need to worry about + + align:start position:0% +need to worry about + + + align:start position:0% +need to worry about +it but when your problem has integers as + + align:start position:0% +it but when your problem has integers as + + + align:start position:0% +it but when your problem has integers as +input uh then they're two + + align:start position:0% + + + + align:start position:0% + +types uh weekly MP hard is in some sense + + align:start position:0% +types uh weekly MP hard is in some sense + + + align:start position:0% +types uh weekly MP hard is in some sense +the type you already know if you think + + align:start position:0% +the type you already know if you think + + + align:start position:0% +the type you already know if you think +about it in the right way in the + + align:start position:0% +about it in the right way in the + + + align:start position:0% +about it in the right way in the +intended way we haven't been super + + align:start position:0% +intended way we haven't been super + + + align:start position:0% +intended way we haven't been super +formal about how numbers get encoded but + + align:start position:0% +formal about how numbers get encoded but + + + align:start position:0% +formal about how numbers get encoded but +uh usually we think of NP hardness as + + align:start position:0% +uh usually we think of NP hardness as + + + align:start position:0% +uh usually we think of NP hardness as +uh uh in terms of the + + align:start position:0% +uh uh in terms of the + + + align:start position:0% +uh uh in terms of the +how how hard your problem is um in terms + + align:start position:0% +how how hard your problem is um in terms + + + align:start position:0% +how how hard your problem is um in terms +of the encoding size which we usually + + align:start position:0% +of the encoding size which we usually + + + align:start position:0% +of the encoding size which we usually +call n the encoding of your + + align:start position:0% +call n the encoding of your + + + align:start position:0% +call n the encoding of your +input okay so in the usual + + align:start position:0% +input okay so in the usual + + + align:start position:0% +input okay so in the usual +form uh what this means is that you + + align:start position:0% +form uh what this means is that you + + + align:start position:0% +form uh what this means is that you +allow + + align:start position:0% +allow + + + align:start position:0% +allow +numbers uh to have exponential + + align:start position:0% + + + + align:start position:0% + +value because even when their value is + + align:start position:0% +value because even when their value is + + + align:start position:0% +value because even when their value is +exponential IAL the encoding of that + + align:start position:0% +exponential IAL the encoding of that + + + align:start position:0% +exponential IAL the encoding of that +value is + + align:start position:0% + + + + align:start position:0% + +polom encoding length of such a number + + align:start position:0% +polom encoding length of such a number + + + align:start position:0% +polom encoding length of such a number +is uh you know if you write in binary + + align:start position:0% +is uh you know if you write in binary + + + align:start position:0% +is uh you know if you write in binary +that's log base 2 of the number if the + + align:start position:0% +that's log base 2 of the number if the + + + align:start position:0% +that's log base 2 of the number if the +number is 2 to the N to the C which is + + align:start position:0% +number is 2 to the N to the C which is + + + align:start position:0% +number is 2 to the N to the C which is +our definition of exponential that's + + align:start position:0% +our definition of exponential that's + + + align:start position:0% +our definition of exponential that's +going to be n the C uh and that's + + align:start position:0% + + + + align:start position:0% + +polinomial okay uh for here I'm going to + + align:start position:0% +polinomial okay uh for here I'm going to + + + align:start position:0% +polinomial okay uh for here I'm going to +let N be the number of numbers to avoid + + align:start position:0% +let N be the number of numbers to avoid + + + align:start position:0% +let N be the number of numbers to avoid +this to avoid uh circular uh definitions + + align:start position:0% +this to avoid uh circular uh definitions + + + align:start position:0% +this to avoid uh circular uh definitions +or something so I'm saying there are n + + align:start position:0% +or something so I'm saying there are n + + + align:start position:0% +or something so I'm saying there are n +different numbers if each of them is at + + align:start position:0% +different numbers if each of them is at + + + align:start position:0% +different numbers if each of them is at +most two to the N to the C in value and + + align:start position:0% +most two to the N to the C in value and + + + align:start position:0% +most two to the N to the C in value and +they're integers then I can encode them + + align:start position:0% +they're integers then I can encode them + + + align:start position:0% +they're integers then I can encode them +in this many bits and that's a + + align:start position:0% +in this many bits and that's a + + + align:start position:0% +in this many bits and that's a +polinomial number of bits so I consider + + align:start position:0% +polinomial number of bits so I consider + + + align:start position:0% +polinomial number of bits so I consider +that a reasonable in + + align:start position:0% +that a reasonable in + + + align:start position:0% +that a reasonable in +coding okay uh and sometimes that's just + + align:start position:0% +coding okay uh and sometimes that's just + + + align:start position:0% +coding okay uh and sometimes that's just +fine but there's a stronger notion which + + align:start position:0% +fine but there's a stronger notion which + + + align:start position:0% +fine but there's a stronger notion which +is really useful especially for a lot of + + align:start position:0% +is really useful especially for a lot of + + + align:start position:0% +is really useful especially for a lot of +problems we will see today and next + + align:start position:0% +problems we will see today and next + + + align:start position:0% +problems we will see today and next +class + + align:start position:0% +class + + + align:start position:0% +class +which is called strongly NP hard and + + align:start position:0% +which is called strongly NP hard and + + + align:start position:0% +which is called strongly NP hard and +this + + align:start position:0% + + + + align:start position:0% + +is NP + + align:start position:0% +is NP + + + align:start position:0% +is NP +hard even + + align:start position:0% +hard even + + + align:start position:0% +hard even +when + + align:start position:0% +when + + + align:start position:0% +when +uh uh your problem is + + align:start position:0% + + + + align:start position:0% + +restricted to + + align:start position:0% + + + + align:start position:0% + +numbers of polinomial + + align:start position:0% + + + + align:start position:0% + +value so polinomial here is with respect + + align:start position:0% +value so polinomial here is with respect + + + align:start position:0% +value so polinomial here is with respect +to n n is the number of integers number + + align:start position:0% +to n n is the number of integers number + + + align:start position:0% +to n n is the number of integers number +of + + align:start position:0% +of + + + align:start position:0% +of +numbers okay so uh strongly NP hard is + + align:start position:0% +numbers okay so uh strongly NP hard is + + + align:start position:0% +numbers okay so uh strongly NP hard is +stronger than weakly NP hard if you have + + align:start position:0% +stronger than weakly NP hard if you have + + + align:start position:0% +stronger than weakly NP hard if you have +if you're NP hard even when your numbers + + align:start position:0% +if you're NP hard even when your numbers + + + align:start position:0% +if you're NP hard even when your numbers +are only polinomial size then of course + + align:start position:0% +are only polinomial size then of course + + + align:start position:0% +are only polinomial size then of course +you're NP hard when you allow the + + align:start position:0% +you're NP hard when you allow the + + + align:start position:0% +you're NP hard when you allow the +numbers to be as large as exponential + + align:start position:0% +numbers to be as large as exponential + + + align:start position:0% +numbers to be as large as exponential +this is a weaker constraint on the + + align:start position:0% +this is a weaker constraint on the + + + align:start position:0% +this is a weaker constraint on the +problem so uh to cut to the chase two + + align:start position:0% +problem so uh to cut to the chase two + + + align:start position:0% +problem so uh to cut to the chase two +partition up here uh and subset sum are + + align:start position:0% +partition up here uh and subset sum are + + + align:start position:0% +partition up here uh and subset sum are +are weekly n beh + + align:start position:0% + + + + align:start position:0% + +hard and if you believe that the that P + + align:start position:0% +hard and if you believe that the that P + + + align:start position:0% +hard and if you believe that the that P +does not equal NP uh then it's not + + align:start position:0% +does not equal NP uh then it's not + + + align:start position:0% +does not equal NP uh then it's not +strongly MP hard that's the best you can + + align:start position:0% +strongly MP hard that's the best you can + + + align:start position:0% +strongly MP hard that's the best you can +hope for whereas three partition and + + align:start position:0% +hope for whereas three partition and + + + align:start position:0% +hope for whereas three partition and +every other problem we talked about is + + align:start position:0% +every other problem we talked about is + + + align:start position:0% +every other problem we talked about is +strongly NP + + align:start position:0% + + + + align:start position:0% + +hard I have a question what do you mean + + align:start position:0% +hard I have a question what do you mean + + + align:start position:0% +hard I have a question what do you mean +exactly by numbers having exponential + + align:start position:0% +exactly by numbers having exponential + + + align:start position:0% +exactly by numbers having exponential +value uh so again + + align:start position:0% +value uh so again + + + align:start position:0% +value uh so again +exponential like 2 the N the c n is the + + align:start position:0% +exponential like 2 the N the c n is the + + + align:start position:0% +exponential like 2 the N the c n is the +number of numbers in your input okay + + align:start position:0% +number of numbers in your input okay + + + align:start position:0% +number of numbers in your input okay +yeah so that's uh that's what I allow I + + align:start position:0% +yeah so that's uh that's what I allow I + + + align:start position:0% +yeah so that's uh that's what I allow I +mean this is what would be allowed if + + align:start position:0% +mean this is what would be allowed if + + + align:start position:0% +mean this is what would be allowed if +you didn't say anything if you interpret + + align:start position:0% +you didn't say anything if you interpret + + + align:start position:0% +you didn't say anything if you interpret +complexity theory in a way that I + + align:start position:0% +complexity theory in a way that I + + + align:start position:0% +complexity theory in a way that I +haven't necessarily told you but uh + + align:start position:0% +haven't necessarily told you but uh + + + align:start position:0% +haven't necessarily told you but uh +generally you want to assume that all + + align:start position:0% +generally you want to assume that all + + + align:start position:0% +generally you want to assume that all +your inputs are reasonably encoded in an + + align:start position:0% +your inputs are reasonably encoded in an + + + align:start position:0% +your inputs are reasonably encoded in an +efficient way that most possible input + + align:start position:0% +efficient way that most possible input + + + align:start position:0% +efficient way that most possible input +strings are valid inputs + + align:start position:0% +strings are valid inputs + + + align:start position:0% +strings are valid inputs +and so if you're encoding your then in + + align:start position:0% +and so if you're encoding your then in + + + align:start position:0% +and so if you're encoding your then in +particular you should encode your + + align:start position:0% +particular you should encode your + + + align:start position:0% +particular you should encode your +numbers in binary or Turner or coronary + + align:start position:0% +numbers in binary or Turner or coronary + + + align:start position:0% +numbers in binary or Turner or coronary +or + + align:start position:0% +or + + + align:start position:0% +or +hexadecimal anything bigger than one is + + align:start position:0% +hexadecimal anything bigger than one is + + + align:start position:0% +hexadecimal anything bigger than one is +good okay you should know if you're + + align:start position:0% +good okay you should know if you're + + + align:start position:0% +good okay you should know if you're +writing down a number don't use uny but + + align:start position:0% +writing down a number don't use uny but + + + align:start position:0% +writing down a number don't use uny but +today we're going to use un a lot so + + align:start position:0% +today we're going to use un a lot so + + + align:start position:0% +today we're going to use un a lot so +this is the same thing as saying uh en + + align:start position:0% +this is the same thing as saying uh en + + + align:start position:0% +this is the same thing as saying uh en +code in un strong NP + + align:start position:0% +code in un strong NP + + + align:start position:0% +code in un strong NP +hardness is like saying well my problem + + align:start position:0% +hardness is like saying well my problem + + + align:start position:0% +hardness is like saying well my problem +is so hard that even if I encode my + + align:start position:0% +is so hard that even if I encode my + + + align:start position:0% +is so hard that even if I encode my +numbers in un it's still hard in the + + align:start position:0% +numbers in un it's still hard in the + + + align:start position:0% +numbers in un it's still hard in the +resulting input size the input size + + align:start position:0% +resulting input size the input size + + + align:start position:0% +resulting input size the input size +would be if you write down every number + + align:start position:0% +would be if you write down every number + + + align:start position:0% +would be if you write down every number +uny add so add up all the numbers that's + + align:start position:0% +uny add so add up all the numbers that's + + + align:start position:0% +uny add so add up all the numbers that's +your input size three partition is that + + align:start position:0% +your input size three partition is that + + + align:start position:0% +your input size three partition is that +hard two partition is + + align:start position:0% +hard two partition is + + + align:start position:0% +hard two partition is +not okay so if you can prove strong + + align:start position:0% +not okay so if you can prove strong + + + align:start position:0% +not okay so if you can prove strong +empty hardness you should it's better if + + align:start position:0% +empty hardness you should it's better if + + + align:start position:0% +empty hardness you should it's better if +you can only prove weak mty hardness + + align:start position:0% +you can only prove weak mty hardness + + + align:start position:0% +you can only prove weak mty hardness +it's okay it's still + + align:start position:0% +it's okay it's still + + + align:start position:0% +it's okay it's still +hard uh now you should know there's + + align:start position:0% +hard uh now you should know there's + + + align:start position:0% +hard uh now you should know there's +corresponding Notions on the algorithm + + align:start position:0% +corresponding Notions on the algorithm + + + align:start position:0% +corresponding Notions on the algorithm +side so let's talk about that a little + + align:start position:0% +side so let's talk about that a little + + + align:start position:0% +side so let's talk about that a little +bit um so corresponding algorithmic + + align:start position:0% +bit um so corresponding algorithmic + + + align:start position:0% +bit um so corresponding algorithmic +Notions are there's actually three of + + align:start position:0% +Notions are there's actually three of + + + align:start position:0% +Notions are there's actually three of +them the main ones are pseudo polinomial + + align:start position:0% +them the main ones are pseudo polinomial + + + align:start position:0% +them the main ones are pseudo polinomial +and weekly polinomial sorry the weeklys + + align:start position:0% +and weekly polinomial sorry the weeklys + + + align:start position:0% +and weekly polinomial sorry the weeklys +are unrelated to each other but that's + + align:start position:0% +are unrelated to each other but that's + + + align:start position:0% +are unrelated to each other but that's +that's + + align:start position:0% + + + + align:start position:0% + +life there's also a oce called strongly + + align:start position:0% +life there's also a oce called strongly + + + align:start position:0% +life there's also a oce called strongly +polinomial unrelated to strongly NP hard + + align:start position:0% +polinomial unrelated to strongly NP hard + + + align:start position:0% +polinomial unrelated to strongly NP hard +here you + + align:start position:0% + + + + align:start position:0% + +go okay + + align:start position:0% +go okay + + + align:start position:0% +go okay +um so weekly polinomial is the usual + + align:start position:0% +um so weekly polinomial is the usual + + + align:start position:0% +um so weekly polinomial is the usual +notion of polinomial I should mention + + align:start position:0% +notion of polinomial I should mention + + + align:start position:0% +notion of polinomial I should mention +when I say I have a polinomial Time + + align:start position:0% +when I say I have a polinomial Time + + + align:start position:0% +when I say I have a polinomial Time +algorithm what you mean is weekly uh + + align:start position:0% +algorithm what you mean is weekly uh + + + align:start position:0% +algorithm what you mean is weekly uh +meaning that uh let's say I'll write it + + align:start position:0% +meaning that uh let's say I'll write it + + + align:start position:0% +meaning that uh let's say I'll write it +as polom in and the number of integers + + align:start position:0% +as polom in and the number of integers + + + align:start position:0% +as polom in and the number of integers +and uh let's say log of the largest + + align:start position:0% + + + + align:start position:0% + +integer largest number in the + + align:start position:0% +integer largest number in the + + + align:start position:0% +integer largest number in the +input okay that's a reasonable encoding + + align:start position:0% +input okay that's a reasonable encoding + + + align:start position:0% +input okay that's a reasonable encoding +size you write them in binary uh you add + + align:start position:0% +size you write them in binary uh you add + + + align:start position:0% +size you write them in binary uh you add +them all up so you multiply that by n or + + align:start position:0% +them all up so you multiply that by n or + + + align:start position:0% +them all up so you multiply that by n or +whatever the polinomial in that value is + + align:start position:0% +whatever the polinomial in that value is + + + align:start position:0% +whatever the polinomial in that value is +weekly polinomial uh pseudo polinomial + + align:start position:0% +weekly polinomial uh pseudo polinomial + + + align:start position:0% +weekly polinomial uh pseudo polinomial +you omit the + + align:start position:0% +you omit the + + + align:start position:0% +you omit the +log okay so I want Pol n and the largest + + align:start position:0% + + + + align:start position:0% + +number and strongly polinomial you emit + + align:start position:0% +number and strongly polinomial you emit + + + align:start position:0% +number and strongly polinomial you emit +that term Al together so you're just + + align:start position:0% +that term Al together so you're just + + + align:start position:0% +that term Al together so you're just +polinomial in the number of + + align:start position:0% +polinomial in the number of + + + align:start position:0% +polinomial in the number of +numbers okay so there's a different + + align:start position:0% +numbers okay so there's a different + + + align:start position:0% +numbers okay so there's a different +world of algorithms which we're not + + align:start position:0% +world of algorithms which we're not + + + align:start position:0% +world of algorithms which we're not +going to talk about here which is weakly + + align:start position:0% +going to talk about here which is weakly + + + align:start position:0% +going to talk about here which is weakly +polinomial algorithms versus strongly + + align:start position:0% +polinomial algorithms versus strongly + + + align:start position:0% +polinomial algorithms versus strongly +polinomial algorithms I'm not aware of + + align:start position:0% +polinomial algorithms I'm not aware of + + + align:start position:0% +polinomial algorithms I'm not aware of +any lower bounds about that but there's + + align:start position:0% +any lower bounds about that but there's + + + align:start position:0% +any lower bounds about that but there's +famous open questions like can you solve + + align:start position:0% +famous open questions like can you solve + + + align:start position:0% +famous open questions like can you solve +linear programming in strongl polinomial + + align:start position:0% +linear programming in strongl polinomial + + + align:start position:0% +linear programming in strongl polinomial +time we don't know there's no hardness + + align:start position:0% +time we don't know there's no hardness + + + align:start position:0% +time we don't know there's no hardness +notion there so we're not going to talk + + align:start position:0% +notion there so we're not going to talk + + + align:start position:0% +notion there so we're not going to talk +about it any more than that um what we + + align:start position:0% +about it any more than that um what we + + + align:start position:0% +about it any more than that um what we +care about more is this distinction + + align:start position:0% +care about more is this distinction + + + align:start position:0% +care about more is this distinction +between pseudo polinomial this is + + align:start position:0% +between pseudo polinomial this is + + + align:start position:0% +between pseudo polinomial this is +polinomial when the numbers are written + + align:start position:0% +polinomial when the numbers are written + + + align:start position:0% +polinomial when the numbers are written +in unary and this is polinomial when the + + align:start position:0% +in unary and this is polinomial when the + + + align:start position:0% +in unary and this is polinomial when the +numbers are written in binary so these + + align:start position:0% +numbers are written in binary so these + + + align:start position:0% +numbers are written in binary so these +two Notions correspond to these two + + align:start position:0% +two Notions correspond to these two + + + align:start position:0% +two Notions correspond to these two +Notions uh so in particular if you + + align:start position:0% +Notions uh so in particular if you + + + align:start position:0% +Notions uh so in particular if you +believe P does not equal NP then weekly + + align:start position:0% +believe P does not equal NP then weekly + + + align:start position:0% +believe P does not equal NP then weekly +NP hard means there is no weekly + + align:start position:0% +NP hard means there is no weekly + + + align:start position:0% +NP hard means there is no weekly +polinomial algorithm + + align:start position:0% +polinomial algorithm + + + align:start position:0% +polinomial algorithm +but there might be a pseudo polinomial + + align:start position:0% +but there might be a pseudo polinomial + + + align:start position:0% +but there might be a pseudo polinomial +algorithm strongly NP hard means there's + + align:start position:0% +algorithm strongly NP hard means there's + + + align:start position:0% +algorithm strongly NP hard means there's +no pseudo poomi algorithm and therefore + + align:start position:0% +no pseudo poomi algorithm and therefore + + + align:start position:0% +no pseudo poomi algorithm and therefore +there's no weakly polinomial algorithm + + align:start position:0% +there's no weakly polinomial algorithm + + + align:start position:0% +there's no weakly polinomial algorithm +Adam so the difference between weekly + + align:start position:0% +Adam so the difference between weekly + + + align:start position:0% +Adam so the difference between weekly +polinomial and strongly polinomial is + + align:start position:0% +polinomial and strongly polinomial is + + + align:start position:0% +polinomial and strongly polinomial is +that we don't even necessarily give + + align:start position:0% +that we don't even necessarily give + + + align:start position:0% +that we don't even necessarily give +ourselves time to read all the numbers + + align:start position:0% +ourselves time to read all the numbers + + + align:start position:0% +ourselves time to read all the numbers +uh okay I put it in binary uh I didn't + + align:start position:0% +uh okay I put it in binary uh I didn't + + + align:start position:0% +uh okay I put it in binary uh I didn't +want to get too much into models of + + align:start position:0% +want to get too much into models of + + + align:start position:0% +want to get too much into models of +computation but the model of computation + + align:start position:0% +computation but the model of computation + + + align:start position:0% +computation but the model of computation +here is that you're allowed to read an + + align:start position:0% +here is that you're allowed to read an + + + align:start position:0% +here is that you're allowed to read an +entire number in one time stamp so if + + align:start position:0% +entire number in one time stamp so if + + + align:start position:0% +entire number in one time stamp so if +you've taken 6851 Advanced data + + align:start position:0% +you've taken 6851 Advanced data + + + align:start position:0% +you've taken 6851 Advanced data +structure this is like uh word Ram so + + align:start position:0% +structure this is like uh word Ram so + + + align:start position:0% +structure this is like uh word Ram so +that's the only reason this would be + + align:start position:0% +that's the only reason this would be + + + align:start position:0% +that's the only reason this would be +reasonable otherwise you couldn't read + + align:start position:0% +reasonable otherwise you couldn't read + + + align:start position:0% +reasonable otherwise you couldn't read +the input that would be pretty hard so + + align:start position:0% +the input that would be pretty hard so + + + align:start position:0% +the input that would be pretty hard so +the the model is you can do you can take + + align:start position:0% +the the model is you can do you can take + + + align:start position:0% +the the model is you can do you can take +a constant number of your numbers do + + align:start position:0% +a constant number of your numbers do + + + align:start position:0% +a constant number of your numbers do +something with them output another + + align:start position:0% +something with them output another + + + align:start position:0% +something with them output another +number of the same type roughly in + + align:start position:0% +number of the same type roughly in + + + align:start position:0% +number of the same type roughly in +constant time and you want to do a + + align:start position:0% +constant time and you want to do a + + + align:start position:0% +constant time and you want to do a +polinomial number of such steps usually + + align:start position:0% +polinomial number of such steps usually + + + align:start position:0% +polinomial number of such steps usually +arithmetic + + align:start position:0% +arithmetic + + + align:start position:0% +arithmetic +operations uh here you don't have to be + + align:start position:0% +operations uh here you don't have to be + + + align:start position:0% +operations uh here you don't have to be +so careful about the model uh because + + align:start position:0% +so careful about the model uh because + + + align:start position:0% +so careful about the model uh because +any reasonable coding you can read it + + align:start position:0% +any reasonable coding you can read it + + + align:start position:0% +any reasonable coding you can read it +and do whatever you want with it if you + + align:start position:0% +and do whatever you want with it if you + + + align:start position:0% +and do whatever you want with it if you +don't care about the exponent the + + align:start position:0% +don't care about the exponent the + + + align:start position:0% +don't care about the exponent the +polinomial all models are equivalent if + + align:start position:0% +polinomial all models are equivalent if + + + align:start position:0% +polinomial all models are equivalent if +you believe the strong Church teing + + align:start position:0% +you believe the strong Church teing + + + align:start position:0% +you believe the strong Church teing +thesis + + align:start position:0% +thesis + + + align:start position:0% +thesis +anyway uh this one you have to be a + + align:start position:0% +anyway uh this one you have to be a + + + align:start position:0% +anyway uh this one you have to be a +little more careful what the model + + align:start position:0% +little more careful what the model + + + align:start position:0% +little more careful what the model +is good so let me draw my favorite + + align:start position:0% +is good so let me draw my favorite + + + align:start position:0% +is good so let me draw my favorite +diagram uh with the difficulty + + align:start position:0% + + + + align:start position:0% + +axis so but now instead of P I'm going + + align:start position:0% +axis so but now instead of P I'm going + + + align:start position:0% +axis so but now instead of P I'm going +to distinguish between weakly polinomial + + align:start position:0% +to distinguish between weakly polinomial + + + align:start position:0% +to distinguish between weakly polinomial +pseudo polinomial and strongly + + align:start position:0% +pseudo polinomial and strongly + + + align:start position:0% +pseudo polinomial and strongly +polinomial so uh these things are pseudo + + align:start position:0% + + + + align:start position:0% + +poly uh these things are weekly + + align:start position:0% + + + + align:start position:0% + +poly and these + + align:start position:0% +poly and these + + + align:start position:0% +poly and these +things are strongly poly this is on the + + align:start position:0% +things are strongly poly this is on the + + + align:start position:0% +things are strongly poly this is on the +algorithm side upper + + align:start position:0% +algorithm side upper + + + align:start position:0% +algorithm side upper +bounds being left of a particular + + align:start position:0% +bounds being left of a particular + + + align:start position:0% +bounds being left of a particular +position and then on the hardness side + + align:start position:0% +position and then on the hardness side + + + align:start position:0% +position and then on the hardness side +we + + align:start position:0% +we + + + align:start position:0% +we +have uh + + align:start position:0% + + + + align:start position:0% + +let me use red it's more + + align:start position:0% +let me use red it's more + + + align:start position:0% +let me use red it's more +dramatic uh this thing is weekly NP + + align:start position:0% + + + + align:start position:0% + +hard this is if P does not equal + + align:start position:0% + + + + align:start position:0% + +NP then you're strictly to the right of + + align:start position:0% +NP then you're strictly to the right of + + + align:start position:0% +NP then you're strictly to the right of +pseudo so there's no pseudo problem + + align:start position:0% +pseudo so there's no pseudo problem + + + align:start position:0% +pseudo so there's no pseudo problem +there's also weakly EMP hard okay and + + align:start position:0% +there's also weakly EMP hard okay and + + + align:start position:0% +there's also weakly EMP hard okay and +then strong strongly empty hard excl + + align:start position:0% +then strong strongly empty hard excl + + + align:start position:0% +then strong strongly empty hard excl +includes even a weekly polinomial + + align:start position:0% + + + + align:start position:0% + +algorithm okay so strictly to the right + + align:start position:0% +algorithm okay so strictly to the right + + + align:start position:0% +algorithm okay so strictly to the right +of that position so obviously strongly + + align:start position:0% +of that position so obviously strongly + + + align:start position:0% +of that position so obviously strongly +EMP hard is a better result because it's + + align:start position:0% +EMP hard is a better result because it's + + + align:start position:0% +EMP hard is a better result because it's +smaller than this + + align:start position:0% +smaller than this + + + align:start position:0% +smaller than this +class um but for example uh two + + align:start position:0% +class um but for example uh two + + + align:start position:0% +class um but for example uh two +partition which is only weekly NP hard + + align:start position:0% +partition which is only weekly NP hard + + + align:start position:0% +partition which is only weekly NP hard +has a pseudo polinomial algorithm you've + + align:start position:0% +has a pseudo polinomial algorithm you've + + + align:start position:0% +has a pseudo polinomial algorithm you've +probably even seen one in your + + align:start position:0% +probably even seen one in your + + + align:start position:0% +probably even seen one in your +algorithms class if you've ever done + + align:start position:0% +algorithms class if you've ever done + + + align:start position:0% +algorithms class if you've ever done +anything like + + align:start position:0% +anything like + + + align:start position:0% +anything like +napsack uh as a dynamic program that is + + align:start position:0% +napsack uh as a dynamic program that is + + + align:start position:0% +napsack uh as a dynamic program that is +a dynamic program probably originally + + align:start position:0% +a dynamic program probably originally + + + align:start position:0% +a dynamic program probably originally +done for two + + align:start position:0% + + + + align:start position:0% + +partition okay so that problem is + + align:start position:0% +partition okay so that problem is + + + align:start position:0% +partition okay so that problem is +somewhere in + + align:start position:0% +somewhere in + + + align:start position:0% +somewhere in +here weekly NP hard oops I think the + + align:start position:0% +here weekly NP hard oops I think the + + + align:start position:0% +here weekly NP hard oops I think the +diagram is backward problem if a problem + + align:start position:0% +diagram is backward problem if a problem + + + align:start position:0% +diagram is backward problem if a problem +is strongly polinomial then it's also + + align:start position:0% +is strongly polinomial then it's also + + + align:start position:0% +is strongly polinomial then it's also +weakly poal so the middle one's + + align:start position:0% +weakly poal so the middle one's + + + align:start position:0% +weakly poal so the middle one's +right thank you that seemed funny right + + align:start position:0% +right thank you that seemed funny right + + + align:start position:0% +right thank you that seemed funny right +strongly polinomial is the tightest + + align:start position:0% +strongly polinomial is the tightest + + + align:start position:0% +strongly polinomial is the tightest +class that's the best result and pseudo + + align:start position:0% +class that's the best result and pseudo + + + align:start position:0% +class that's the best result and pseudo +poly is the worst + + align:start position:0% +poly is the worst + + + align:start position:0% +poly is the worst +result did I get my arrows in the right + + align:start position:0% +result did I get my arrows in the right + + + align:start position:0% +result did I get my arrows in the right +place shift over shift over + + align:start position:0% +place shift over shift over + + + align:start position:0% +place shift over shift over +one right strongly NP + + align:start position:0% +one right strongly NP + + + align:start position:0% +one right strongly NP +hard + + align:start position:0% + + + + align:start position:0% + +whoops + + align:start position:0% +whoops + + + align:start position:0% +whoops +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so weakly NP heart is here strongly NP + + align:start position:0% +so weakly NP heart is here strongly NP + + + align:start position:0% +so weakly NP heart is here strongly NP +heart is + + align:start position:0% +heart is + + + align:start position:0% +heart is +there + + align:start position:0% +there + + + align:start position:0% +there +okay cool so uh let's check so two + + align:start position:0% +okay cool so uh let's check so two + + + align:start position:0% +okay cool so uh let's check so two +partition should be pseudo so left of + + align:start position:0% +partition should be pseudo so left of + + + align:start position:0% +partition should be pseudo so left of +this line uh but weekly and be hard so + + align:start position:0% +this line uh but weekly and be hard so + + + align:start position:0% +this line uh but weekly and be hard so +right of that line that looks good so + + align:start position:0% +right of that line that looks good so + + + align:start position:0% +right of that line that looks good so +this is two + + align:start position:0% +this is two + + + align:start position:0% +this is two +partition three partition is out + + align:start position:0% + + + + align:start position:0% + +here I mean I draw this as a region but + + align:start position:0% +here I mean I draw this as a region but + + + align:start position:0% +here I mean I draw this as a region but +it's more like a point in my old diagram + + align:start position:0% +it's more like a point in my old diagram + + + align:start position:0% +it's more like a point in my old diagram +uh because three partition is actually + + align:start position:0% +uh because three partition is actually + + + align:start position:0% +uh because three partition is actually +in NP so it's strongly NP complete uh so + + align:start position:0% +in NP so it's strongly NP complete uh so + + + align:start position:0% +in NP so it's strongly NP complete uh so +it's like right at the edge there anyway + + align:start position:0% +it's like right at the edge there anyway + + + align:start position:0% +it's like right at the edge there anyway +there's no pseudo poomi algorithm for + + align:start position:0% +there's no pseudo poomi algorithm for + + + align:start position:0% +there's no pseudo poomi algorithm for +three partition unlike two partition the + + align:start position:0% +three partition unlike two partition the + + + align:start position:0% +three partition unlike two partition the +point of all + + align:start position:0% +point of all + + + align:start position:0% +point of all +that let's do some reduction shall we NP + + align:start position:0% +that let's do some reduction shall we NP + + + align:start position:0% +that let's do some reduction shall we NP +hardcore + + align:start position:0% +hardcore + + + align:start position:0% +hardcore +time uh + + align:start position:0% +time uh + + + align:start position:0% +time uh +so maybe over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +okay the first reduction is going to be + + align:start position:0% +okay the first reduction is going to be + + + align:start position:0% +okay the first reduction is going to be +pretty can I ask a question go on so why + + align:start position:0% +pretty can I ask a question go on so why + + + align:start position:0% +pretty can I ask a question go on so why +is there no corresponding notion for + + align:start position:0% +is there no corresponding notion for + + + align:start position:0% +is there no corresponding notion for +problems that are not numeric like why + + align:start position:0% +problems that are not numeric like why + + + align:start position:0% +problems that are not numeric like why +isn't why can't for a graph problem we + + align:start position:0% +isn't why can't for a graph problem we + + + align:start position:0% +isn't why can't for a graph problem we +say well we're going to examine this + + align:start position:0% +say well we're going to examine this + + + align:start position:0% +say well we're going to examine this +graph problem assuming we're using an + + align:start position:0% +graph problem assuming we're using an + + + align:start position:0% +graph problem assuming we're using an +inefficient encoding of our graph to see + + align:start position:0% +inefficient encoding of our graph to see + + + align:start position:0% +inefficient encoding of our graph to see +how hard it is uh I guess you could try + + align:start position:0% +how hard it is uh I guess you could try + + + align:start position:0% +how hard it is uh I guess you could try +to Define this in terms for graphs but I + + align:start position:0% +to Define this in terms for graphs but I + + + align:start position:0% +to Define this in terms for graphs but I +don't think there's such an obvious + + align:start position:0% +don't think there's such an obvious + + + align:start position:0% +don't think there's such an obvious +inefficient notion of + + align:start position:0% +inefficient notion of + + + align:start position:0% +inefficient notion of +graphs uh I mean the obvious inefficient + + align:start position:0% +graphs uh I mean the obvious inefficient + + + align:start position:0% +graphs uh I mean the obvious inefficient +notion is like use a matrix instead of + + align:start position:0% +notion is like use a matrix instead of + + + align:start position:0% +notion is like use a matrix instead of +an uency list but that's polom + + align:start position:0% +an uency list but that's polom + + + align:start position:0% +an uency list but that's polom +equivalent so if I mean there certainly + + align:start position:0% +equivalent so if I mean there certainly + + + align:start position:0% +equivalent so if I mean there certainly +are other Notions you could imagine but + + align:start position:0% +are other Notions you could imagine but + + + align:start position:0% +are other Notions you could imagine but +uh but there aren't any in the + + align:start position:0% +uh but there aren't any in the + + + align:start position:0% +uh but there aren't any in the +literature all right so uh just to warn + + align:start position:0% +literature all right so uh just to warn + + + align:start position:0% +literature all right so uh just to warn +you the first reduction we do is going + + align:start position:0% +you the first reduction we do is going + + + align:start position:0% +you the first reduction we do is going +to be a little bit trivial so don't get + + align:start position:0% +to be a little bit trivial so don't get + + + align:start position:0% +to be a little bit trivial so don't get +too excited yet uh but this is where + + align:start position:0% +too excited yet uh but this is where + + + align:start position:0% +too excited yet uh but this is where +three partition comes from + + align:start position:0% +three partition comes from + + + align:start position:0% +three partition comes from +then we'll do lots of cool cool + + align:start position:0% +then we'll do lots of cool cool + + + align:start position:0% +then we'll do lots of cool cool +ones so multiprocessor + + align:start position:0% +ones so multiprocessor + + + align:start position:0% +ones so multiprocessor +scheduling let's say I have n + + align:start position:0% +scheduling let's say I have n + + + align:start position:0% +scheduling let's say I have n +jobs uh and they have uh completion + + align:start position:0% +jobs uh and they have uh completion + + + align:start position:0% +jobs uh and they have uh completion +times and that's it you can start them + + align:start position:0% +times and that's it you can start them + + + align:start position:0% +times and that's it you can start them +whenever you + + align:start position:0% + + + + align:start position:0% + +want um and then on the other hand I + + align:start position:0% +want um and then on the other hand I + + + align:start position:0% +want um and then on the other hand I +have P processors to run those jobs each + + align:start position:0% +have P processors to run those jobs each + + + align:start position:0% +have P processors to run those jobs each +processor is sequential and I identical + + align:start position:0% +processor is sequential and I identical + + + align:start position:0% +processor is sequential and I identical +so the model is you assign jobs to + + align:start position:0% +so the model is you assign jobs to + + + align:start position:0% +so the model is you assign jobs to +processors job can only be on One + + align:start position:0% +processors job can only be on One + + + align:start position:0% +processors job can only be on One +processor and it runs to completion then + + align:start position:0% +processor and it runs to completion then + + + align:start position:0% +processor and it runs to completion then +it can run another job and so on my + + align:start position:0% +it can run another job and so on my + + + align:start position:0% +it can run another job and so on my +goal uh I'll State the decision version + + align:start position:0% +goal uh I'll State the decision version + + + align:start position:0% +goal uh I'll State the decision version +is to uh finish all + + align:start position:0% +is to uh finish all + + + align:start position:0% +is to uh finish all +jobs in + + align:start position:0% +jobs in + + + align:start position:0% +jobs in +time less than or equal to + + align:start position:0% + + + + align:start position:0% + +T okay so I claim this problem is NP + + align:start position:0% +T okay so I claim this problem is NP + + + align:start position:0% +T okay so I claim this problem is NP +some variety let's start with a + + align:start position:0% + + + + align:start position:0% + +reduction from + + align:start position:0% + + + + align:start position:0% + +partition uh sorry um partition is a + + align:start position:0% +partition uh sorry um partition is a + + + align:start position:0% +partition uh sorry um partition is a +synonym for two partition usually we + + align:start position:0% +synonym for two partition usually we + + + align:start position:0% +synonym for two partition usually we +omit the + + align:start position:0% + + + + align:start position:0% + +two so reduction from + + align:start position:0% +two so reduction from + + + align:start position:0% +two so reduction from +partition this problem over here so I'm + + align:start position:0% +partition this problem over here so I'm + + + align:start position:0% +partition this problem over here so I'm +now I'm given some integers I want to + + align:start position:0% +now I'm given some integers I want to + + + align:start position:0% +now I'm given some integers I want to +split them in half + + align:start position:0% +split them in half + + + align:start position:0% +split them in half +basically uh any suggestions on what I + + align:start position:0% +basically uh any suggestions on what I + + + align:start position:0% +basically uh any suggestions on what I +could do to turn that into a + + align:start position:0% +could do to turn that into a + + + align:start position:0% +could do to turn that into a +multiprocessor scheduling + + align:start position:0% +multiprocessor scheduling + + + align:start position:0% +multiprocessor scheduling +problem two processor two processors + + align:start position:0% +problem two processor two processors + + + align:start position:0% +problem two processor two processors +yeah P equals 2 that is the reduction I + + align:start position:0% +yeah P equals 2 that is the reduction I + + + align:start position:0% +yeah P equals 2 that is the reduction I +guess technically I also have to specify + + align:start position:0% +guess technically I also have to specify + + + align:start position:0% +guess technically I also have to specify +what T is uh but it's over there so you + + align:start position:0% +what T is uh but it's over there so you + + + align:start position:0% +what T is uh but it's over there so you +set T to be the sum of the A's over two + + align:start position:0% +set T to be the sum of the A's over two + + + align:start position:0% +set T to be the sum of the A's over two +and you don't change a you just leave it + + align:start position:0% +and you don't change a you just leave it + + + align:start position:0% +and you don't change a you just leave it +alone so you just feed in the same AIS + + align:start position:0% +alone so you just feed in the same AIS + + + align:start position:0% +alone so you just feed in the same AIS +into this problem and that is two + + align:start position:0% +into this problem and that is two + + + align:start position:0% +into this problem and that is two +partition okay let's do a reduction from + + align:start position:0% +partition okay let's do a reduction from + + + align:start position:0% +partition okay let's do a reduction from +so now we know the problem is at least + + align:start position:0% +so now we know the problem is at least + + + align:start position:0% +so now we know the problem is at least +weakly NP hard but in fact it is + + align:start position:0% +weakly NP hard but in fact it is + + + align:start position:0% +weakly NP hard but in fact it is +strongly NP hard because we can reduce + + align:start position:0% +strongly NP hard because we can reduce + + + align:start position:0% +strongly NP hard because we can reduce +from three partition what do you + + align:start position:0% +from three partition what do you + + + align:start position:0% +from three partition what do you +do p n p equal n + + align:start position:0% +do p n p equal n + + + align:start position:0% +do p n p equal n +over3 that's it uh you set T accordingly + + align:start position:0% +over3 that's it uh you set T accordingly + + + align:start position:0% +over3 that's it uh you set T accordingly +some of the A's over + + align:start position:0% +some of the A's over + + + align:start position:0% +some of the A's over +P + + align:start position:0% +P + + + align:start position:0% +P +done okay uh so um this problem comes + + align:start position:0% +done okay uh so um this problem comes + + + align:start position:0% +done okay uh so um this problem comes +from the paper that introduces three + + align:start position:0% +from the paper that introduces three + + + align:start position:0% +from the paper that introduces three +part partition which is by Gary and + + align:start position:0% +part partition which is by Gary and + + + align:start position:0% +part partition which is by Gary and +Johnson same people who wrote the book + + align:start position:0% +Johnson same people who wrote the book + + + align:start position:0% +Johnson same people who wrote the book +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so this is I mean this basically is + + align:start position:0% +so this is I mean this basically is + + + align:start position:0% +so this is I mean this basically is +three partition that's why they cared + + align:start position:0% +three partition that's why they cared + + + align:start position:0% +three partition that's why they cared +about it but here's a practical + + align:start position:0% +about it but here's a practical + + + align:start position:0% +about it but here's a practical +motivation for + + align:start position:0% +motivation for + + + align:start position:0% +motivation for +it uh cool let's do something more + + align:start position:0% +it uh cool let's do something more + + + align:start position:0% +it uh cool let's do something more +interesting and I got to want a + + align:start position:0% + + + + align:start position:0% + +projector um any questions + + align:start position:0% +projector um any questions + + + align:start position:0% +projector um any questions +about uh I think youve had enough + + align:start position:0% +about uh I think youve had enough + + + align:start position:0% +about uh I think youve had enough +questions about pseudo poly weakly poly + + align:start position:0% +questions about pseudo poly weakly poly + + + align:start position:0% +questions about pseudo poly weakly poly +strongly poly as I erase them don't + + align:start position:0% +strongly poly as I erase them don't + + + align:start position:0% +strongly poly as I erase them don't +forget + + align:start position:0% +forget + + + align:start position:0% +forget +them uh but I think for the rest of + + align:start position:0% +them uh but I think for the rest of + + + align:start position:0% +them uh but I think for the rest of +today we're just going to be doing + + align:start position:0% +today we're just going to be doing + + + align:start position:0% +today we're just going to be doing +strong polinomial reductions uh from + + align:start position:0% +strong polinomial reductions uh from + + + align:start position:0% +strong polinomial reductions uh from +three partition I think next class we + + align:start position:0% +three partition I think next class we + + + align:start position:0% +three partition I think next class we +might do some weak ones but + + align:start position:0% +might do some weak ones but + + + align:start position:0% +might do some weak ones but +uh today we're going to really use the + + align:start position:0% +uh today we're going to really use the + + + align:start position:0% +uh today we're going to really use the +fact that it uh use the strongness and + + align:start position:0% +fact that it uh use the strongness and + + + align:start position:0% +fact that it uh use the strongness and +you'll see why because we really want to + + align:start position:0% +you'll see why because we really want to + + + align:start position:0% +you'll see why because we really want to +encode some numbers in + + align:start position:0% +encode some numbers in + + + align:start position:0% +encode some numbers in +un okay well let's start with what uh + + align:start position:0% +un okay well let's start with what uh + + + align:start position:0% +un okay well let's start with what uh +with a + + align:start position:0% +with a + + + align:start position:0% +with a +problem rectangle packing this is going + + align:start position:0% +problem rectangle packing this is going + + + align:start position:0% +problem rectangle packing this is going +to lead us to a whole bunch of other + + align:start position:0% +to lead us to a whole bunch of other + + + align:start position:0% +to lead us to a whole bunch of other +types of packing problems so this is + + align:start position:0% +types of packing problems so this is + + + align:start position:0% +types of packing problems so this is +what you might call Packing rectangles + + align:start position:0% +what you might call Packing rectangles + + + align:start position:0% +what you might call Packing rectangles +into a rectangle so I'm given uh n + + align:start position:0% + + + + align:start position:0% + +rectangles and I'm given a Target + + align:start position:0% + + + + align:start position:0% + +rectangle so when I say I'm given a + + align:start position:0% +rectangle so when I say I'm given a + + + align:start position:0% +rectangle so when I say I'm given a +rectangle what I really mean is I'm + + align:start position:0% +rectangle what I really mean is I'm + + + align:start position:0% +rectangle what I really mean is I'm +given the dimensions the width and the + + align:start position:0% +given the dimensions the width and the + + + align:start position:0% +given the dimensions the width and the +height as integers we're usually going + + align:start position:0% +height as integers we're usually going + + + align:start position:0% +height as integers we're usually going +to assume all our numbers of integers as + + align:start position:0% +to assume all our numbers of integers as + + + align:start position:0% +to assume all our numbers of integers as +I said + + align:start position:0% +I said + + + align:start position:0% +I said +uh do they + + align:start position:0% + + + + align:start position:0% + +fit so what I'd like in a solution is to + + align:start position:0% +fit so what I'd like in a solution is to + + + align:start position:0% +fit so what I'd like in a solution is to +rotate and translate the the given + + align:start position:0% +rotate and translate the the given + + + align:start position:0% +rotate and translate the the given +rectangles so that they're disjoint from + + align:start position:0% +rectangles so that they're disjoint from + + + align:start position:0% +rectangles so that they're disjoint from +each other they can't overlap and they + + align:start position:0% +each other they can't overlap and they + + + align:start position:0% +each other they can't overlap and they +all fit inside the target rectangle + + align:start position:0% +all fit inside the target rectangle + + + align:start position:0% +all fit inside the target rectangle +right so this might be the target + + align:start position:0% +right so this might be the target + + + align:start position:0% +right so this might be the target +rectangle and then I don't know maybe + + align:start position:0% +rectangle and then I don't know maybe + + + align:start position:0% +rectangle and then I don't know maybe +this is is my set of rectangles + + align:start position:0% +this is is my set of rectangles + + + align:start position:0% +this is is my set of rectangles +appropriately + + align:start position:0% + + + + align:start position:0% + +packed uh so here maybe the answer is + + align:start position:0% +packed uh so here maybe the answer is + + + align:start position:0% +packed uh so here maybe the answer is +yes if they don't fit inside the target + + align:start position:0% +yes if they don't fit inside the target + + + align:start position:0% +yes if they don't fit inside the target +rectangle the answer is no this problem + + align:start position:0% +rectangle the answer is no this problem + + + align:start position:0% +rectangle the answer is no this problem +is strongly NP hard uh but I'm pretty + + align:start position:0% +is strongly NP hard uh but I'm pretty + + + align:start position:0% +is strongly NP hard uh but I'm pretty +sure we don't know whether it's in + + align:start position:0% + + + + align:start position:0% + +NP so there are there are lots of open + + align:start position:0% +NP so there are there are lots of open + + + align:start position:0% +NP so there are there are lots of open +problems I don't mean to indicate + + align:start position:0% +problems I don't mean to indicate + + + align:start position:0% +problems I don't mean to indicate +everything's known uh this is a I should + + align:start position:0% +everything's known uh this is a I should + + + align:start position:0% +everything's known uh this is a I should +double check that this definitely not + + align:start position:0% +double check that this definitely not + + + align:start position:0% +double check that this definitely not +known but pretty sure it's open because + + align:start position:0% +known but pretty sure it's open because + + + align:start position:0% +known but pretty sure it's open because +of this rotation issue there's kind of a + + align:start position:0% +of this rotation issue there's kind of a + + + align:start position:0% +of this rotation issue there's kind of a +lot of things to worry about so it's not + + align:start position:0% +lot of things to worry about so it's not + + + align:start position:0% +lot of things to worry about so it's not +clear how efficiently you can encode a + + align:start position:0% +clear how efficiently you can encode a + + + align:start position:0% +clear how efficiently you can encode a +solution maybe you need a ton of bits of + + align:start position:0% +solution maybe you need a ton of bits of + + + align:start position:0% +solution maybe you need a ton of bits of +precision to say how things are rotated + + align:start position:0% +precision to say how things are rotated + + + align:start position:0% +precision to say how things are rotated +here they're all rotated at the same + + align:start position:0% +here they're all rotated at the same + + + align:start position:0% +here they're all rotated at the same +angle they may not be who knows uh so we + + align:start position:0% +angle they may not be who knows uh so we + + + align:start position:0% +angle they may not be who knows uh so we +will consider a a a special + + align:start position:0% +will consider a a a special + + + align:start position:0% +will consider a a a special +case which is + + align:start position:0% +case which is + + + align:start position:0% +case which is +um exact + + align:start position:0% +um exact + + + align:start position:0% +um exact +packing this also makes for a stronger + + align:start position:0% +packing this also makes for a stronger + + + align:start position:0% +packing this also makes for a stronger +hardness result so exact packing means + + align:start position:0% +hardness result so exact packing means + + + align:start position:0% +hardness result so exact packing means +uh there are no + + align:start position:0% + + + + align:start position:0% + +gaps none of this + + align:start position:0% +gaps none of this + + + align:start position:0% +gaps none of this +stuff that's forbidden so if you have no + + align:start position:0% +stuff that's forbidden so if you have no + + + align:start position:0% +stuff that's forbidden so if you have no +gaps and you look at a corner of the + + align:start position:0% +gaps and you look at a corner of the + + + align:start position:0% +gaps and you look at a corner of the +rectangle that must mean there's a + + align:start position:0% +rectangle that must mean there's a + + + align:start position:0% +rectangle that must mean there's a +rectangle right there filling the corner + + align:start position:0% +rectangle right there filling the corner + + + align:start position:0% +rectangle right there filling the corner +which means there's no rotation well you + + align:start position:0% +which means there's no rotation well you + + + align:start position:0% +which means there's no rotation well you +could rotate by multiples of + + align:start position:0% +could rotate by multiples of + + + align:start position:0% +could rotate by multiples of +90 uh but so there's four rotations but + + align:start position:0% +90 uh but so there's four rotations but + + + align:start position:0% +90 uh but so there's four rotations but +I guess two for + + align:start position:0% +I guess two for + + + align:start position:0% +I guess two for +rectangles + + align:start position:0% + + + + align:start position:0% + +um into + + align:start position:0% +um into + + + align:start position:0% +um into +time + + align:start position:0% + + + + align:start position:0% + +90° so uh then the problem is in NP um + + align:start position:0% +90° so uh then the problem is in NP um + + + align:start position:0% +90° so uh then the problem is in NP um +because also you can show at that point + + align:start position:0% +because also you can show at that point + + + align:start position:0% +because also you can show at that point +because you have integer rectangles + + align:start position:0% +because you have integer rectangles + + + align:start position:0% +because you have integer rectangles +packing into an integer rectangle by + + align:start position:0% +packing into an integer rectangle by + + + align:start position:0% +packing into an integer rectangle by +induction uh the translations are + + align:start position:0% +induction uh the translations are + + + align:start position:0% +induction uh the translations are +integers therefore there are succinct + + align:start position:0% +integers therefore there are succinct + + + align:start position:0% +integers therefore there are succinct +codings of + + align:start position:0% + + + + align:start position:0% + +them okay we don't have to do this but + + align:start position:0% +them okay we don't have to do this but + + + align:start position:0% +them okay we don't have to do this but +this is just to point out this is one + + align:start position:0% +this is just to point out this is one + + + align:start position:0% +this is just to point out this is one +way to make the problem in NP now there + + align:start position:0% +way to make the problem in NP now there + + + align:start position:0% +way to make the problem in NP now there +assing Solutions um so we're going to + + align:start position:0% +assing Solutions um so we're going to + + + align:start position:0% +assing Solutions um so we're going to +prove both of these problems are + + align:start position:0% +prove both of these problems are + + + align:start position:0% +prove both of these problems are +strongly n be + + align:start position:0% +strongly n be + + + align:start position:0% +strongly n be +hard + + align:start position:0% +hard + + + align:start position:0% +hard +uh I think I'll I'll skip the we can't + + align:start position:0% +uh I think I'll I'll skip the we can't + + + align:start position:0% +uh I think I'll I'll skip the we can't +be hardness proof because it's not + + align:start position:0% +be hardness proof because it's not + + + align:start position:0% +be hardness proof because it's not +really any harder no pun intended um so + + align:start position:0% +really any harder no pun intended um so + + + align:start position:0% +really any harder no pun intended um so +let's + + align:start position:0% +let's + + + align:start position:0% +let's +go + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% + + + + align:start position:0% + +so uh basic idea again we're reducing + + align:start position:0% +so uh basic idea again we're reducing + + + align:start position:0% +so uh basic idea again we're reducing +from three + + align:start position:0% + + + + align:start position:0% + +partition so that means we're given an + + align:start position:0% +partition so that means we're given an + + + align:start position:0% +partition so that means we're given an +instance of three partition we're given + + align:start position:0% +instance of three partition we're given + + + align:start position:0% +instance of three partition we're given +an integers we want to represent those + + align:start position:0% +an integers we want to represent those + + + align:start position:0% +an integers we want to represent those +integers as rectangles so kind of the + + align:start position:0% +integers as rectangles so kind of the + + + align:start position:0% +integers as rectangles so kind of the +obvious way to do that is we take each + + align:start position:0% +obvious way to do that is we take each + + + align:start position:0% +obvious way to do that is we take each +Ai and we convert it into a rectangle + + align:start position:0% +Ai and we convert it into a rectangle + + + align:start position:0% +Ai and we convert it into a rectangle +let's say it's a AI by one that seems + + align:start position:0% +let's say it's a AI by one that seems + + + align:start position:0% +let's say it's a AI by one that seems +pretty obvious this is what you might + + align:start position:0% +pretty obvious this is what you might + + + align:start position:0% +pretty obvious this is what you might +call the AI Gadget this we're going to + + align:start position:0% +call the AI Gadget this we're going to + + + align:start position:0% +call the AI Gadget this we're going to +map this feature of our given instance + + align:start position:0% +map this feature of our given instance + + + align:start position:0% +map this feature of our given instance +to this feature of our constructed + + align:start position:0% +to this feature of our constructed + + + align:start position:0% +to this feature of our constructed +instance uh all that would be left at + + align:start position:0% +instance uh all that would be left at + + + align:start position:0% +instance uh all that would be left at +this point is what is the target + + align:start position:0% +this point is what is the target + + + align:start position:0% +this point is what is the target +rectangle um which I didn't give a + + align:start position:0% +rectangle um which I didn't give a + + + align:start position:0% +rectangle um which I didn't give a +name + + align:start position:0% +name + + + align:start position:0% +name +so let me call the target rectangle + + align:start position:0% +so let me call the target rectangle + + + align:start position:0% +so let me call the target rectangle +B that's what I use in my notes + + align:start position:0% + + + + align:start position:0% + +yeah uh so let's say B is going to + + align:start position:0% +yeah uh so let's say B is going to + + + align:start position:0% +yeah uh so let's say B is going to +be it's + + align:start position:0% + + + + align:start position:0% + +rectangle uh what is the height of the + + align:start position:0% +rectangle uh what is the height of the + + + align:start position:0% +rectangle uh what is the height of the +rectangle n over + + align:start position:0% +rectangle n over + + + align:start position:0% +rectangle n over +three yes right and then the width the + + align:start position:0% +three yes right and then the width the + + + align:start position:0% +three yes right and then the width the +sum divid + + align:start position:0% +sum divid + + + align:start position:0% +sum divid +by the Target sum yeah + + align:start position:0% + + + + align:start position:0% + +T cool so um the intent is uh if I that + + align:start position:0% +T cool so um the intent is uh if I that + + + align:start position:0% +T cool so um the intent is uh if I that +the rectangles will look something like + + align:start position:0% +the rectangles will look something like + + + align:start position:0% +the rectangles will look something like +this and always however uh if I fit + + align:start position:0% +this and always however uh if I fit + + + align:start position:0% +this and always however uh if I fit +three in here or maybe I could do more + + align:start position:0% +three in here or maybe I could do more + + + align:start position:0% +three in here or maybe I could do more +than three but uh we know that won't + + align:start position:0% +than three but uh we know that won't + + + align:start position:0% +than three but uh we know that won't +happen with the actual three partition + + align:start position:0% +happen with the actual three partition + + + align:start position:0% +happen with the actual three partition +instances we get uh because we can + + align:start position:0% +instances we get uh because we can + + + align:start position:0% +instances we get uh because we can +assume there's three of them but anyway + + align:start position:0% +assume there's three of them but anyway + + + align:start position:0% +assume there's three of them but anyway +uh we're not constraining there's only + + align:start position:0% +uh we're not constraining there's only + + + align:start position:0% +uh we're not constraining there's only +three you put in however many rectangles + + align:start position:0% +three you put in however many rectangles + + + align:start position:0% +three you put in however many rectangles +that add up to exactly the target sum + + align:start position:0% +that add up to exactly the target sum + + + align:start position:0% +that add up to exactly the target sum +boom you've got the target sum uh and + + align:start position:0% +boom you've got the target sum uh and + + + align:start position:0% +boom you've got the target sum uh and +there's just enough space for all of + + align:start position:0% +there's just enough space for all of + + + align:start position:0% +there's just enough space for all of +them if you pack them this way question + + align:start position:0% +them if you pack them this way question + + + align:start position:0% +them if you pack them this way question +uh shouldn't we specify that the AI + + align:start position:0% +uh shouldn't we specify that the AI + + + align:start position:0% +uh shouldn't we specify that the AI +rectangle is AI * n 3 + 1 to make sure + + align:start position:0% +rectangle is AI * n 3 + 1 to make sure + + + align:start position:0% +rectangle is AI * n 3 + 1 to make sure +that we can't accidentally rotate them + + align:start position:0% +that we can't accidentally rotate them + + + align:start position:0% +that we can't accidentally rotate them +yeah so uh part of my confusion in + + align:start position:0% +yeah so uh part of my confusion in + + + align:start position:0% +yeah so uh part of my confusion in +drawing this and a worry is you can take + + align:start position:0% +drawing this and a worry is you can take + + + align:start position:0% +drawing this and a worry is you can take +one of these rectangles and rotate it + + align:start position:0% +one of these rectangles and rotate it + + + align:start position:0% +one of these rectangles and rotate it +and then this reduction is wrong + + align:start position:0% +and then this reduction is wrong + + + align:start position:0% +and then this reduction is wrong +so this reduction is wrong uh so I will + + align:start position:0% +so this reduction is wrong uh so I will + + + align:start position:0% +so this reduction is wrong uh so I will +cheat and make this + + align:start position:0% +cheat and make this + + + align:start position:0% +cheat and make this +Epsilon and then multipli this by + + align:start position:0% +Epsilon and then multipli this by + + + align:start position:0% +Epsilon and then multipli this by +Epsilon this is one way to fix it of + + align:start position:0% +Epsilon this is one way to fix it of + + + align:start position:0% +Epsilon this is one way to fix it of +course now I have to scale everything up + + align:start position:0% +course now I have to scale everything up + + + align:start position:0% +course now I have to scale everything up +by one over Epsilon I have to tell you + + align:start position:0% +by one over Epsilon I have to tell you + + + align:start position:0% +by one over Epsilon I have to tell you +what Epsilon is uh you suggesting some + + align:start position:0% +what Epsilon is uh you suggesting some + + + align:start position:0% +what Epsilon is uh you suggesting some +multiple of N is a good good suggestion + + align:start position:0% +multiple of N is a good good suggestion + + + align:start position:0% +multiple of N is a good good suggestion +I think as long as we make this like + + align:start position:0% +I think as long as we make this like + + + align:start position:0% +I think as long as we make this like +much smaller than one then it's not + + align:start position:0% +much smaller than one then it's not + + + align:start position:0% +much smaller than one then it's not +possible to rotate because these guys + + align:start position:0% +possible to rotate because these guys + + + align:start position:0% +possible to rotate because these guys +are length at least one because they're + + align:start position:0% +are length at least one because they're + + + align:start position:0% +are length at least one because they're +integers so if I tried to rotate it has + + align:start position:0% +integers so if I tried to rotate it has + + + align:start position:0% +integers so if I tried to rotate it has +to be multiple 90° so I think as long as + + align:start position:0% +to be multiple 90° so I think as long as + + + align:start position:0% +to be multiple 90° so I think as long as +this is strictly less than one uh we are + + align:start position:0% +this is strictly less than one uh we are + + + align:start position:0% +this is strictly less than one uh we are +okay I didn't change the intended + + align:start position:0% +okay I didn't change the intended + + + align:start position:0% +okay I didn't change the intended +solution I just made everything + + align:start position:0% +solution I just made everything + + + align:start position:0% +solution I just made everything +narrower and so I just need to set + + align:start position:0% +narrower and so I just need to set + + + align:start position:0% +narrower and so I just need to set +Epsilon less than + + align:start position:0% +Epsilon less than + + + align:start position:0% +Epsilon less than +3n would be that + + align:start position:0% +3n would be that + + + align:start position:0% +3n would be that +inequality uh but I want integers so I + + align:start position:0% +inequality uh but I want integers so I + + + align:start position:0% +inequality uh but I want integers so I +should scale everything up by n over3 so + + align:start position:0% +should scale everything up by n over3 so + + + align:start position:0% +should scale everything up by n over3 so +just multiply all the numbers by n over + + align:start position:0% +just multiply all the numbers by n over + + + align:start position:0% +just multiply all the numbers by n over +three and you're + + align:start position:0% +three and you're + + + align:start position:0% +three and you're +done uh in fact you can be a little + + align:start position:0% +done uh in fact you can be a little + + + align:start position:0% +done uh in fact you can be a little +simpler and I drew this diagram long ago + + align:start position:0% +simpler and I drew this diagram long ago + + + align:start position:0% +simpler and I drew this diagram long ago +so I might as well show it to you uh you + + align:start position:0% +so I might as well show it to you uh you + + + align:start position:0% +so I might as well show it to you uh you +can just add N3 to all your integers + + align:start position:0% +can just add N3 to all your integers + + + align:start position:0% +can just add N3 to all your integers +that will also work um under the + + align:start position:0% +that will also work um under the + + + align:start position:0% +that will also work um under the +assumption that you only have you can + + align:start position:0% +assumption that you only have you can + + + align:start position:0% +assumption that you only have you can +only take three numbers and add them up + + align:start position:0% +only take three numbers and add them up + + + align:start position:0% +only take three numbers and add them up +then you'll always be adding three times + + align:start position:0% +then you'll always be adding three times + + + align:start position:0% +then you'll always be adding three times +n over3 + + align:start position:0% +n over3 + + + align:start position:0% +n over3 +horizontally um and so so the AIS here + + align:start position:0% +horizontally um and so so the AIS here + + + align:start position:0% +horizontally um and so so the AIS here +are this the yellow part of these + + align:start position:0% +are this the yellow part of these + + + align:start position:0% +are this the yellow part of these +rectangles and then we're just adding + + align:start position:0% +rectangles and then we're just adding + + + align:start position:0% +rectangles and then we're just adding +this fixed n over three to all of them + + align:start position:0% +this fixed n over three to all of them + + + align:start position:0% +this fixed n over three to all of them +so is a four four four four five five + + align:start position:0% +so is a four four four four five five + + + align:start position:0% +so is a four four four four five five +five six 7 + + align:start position:0% +five six 7 + + + align:start position:0% +five six 7 +um and that happens to be a positive + + align:start position:0% +um and that happens to be a positive + + + align:start position:0% +um and that happens to be a positive +instance of three partition there is a + + align:start position:0% +instance of three partition there is a + + + align:start position:0% +instance of three partition there is a +solution this is one way to do it so + + align:start position:0% +solution this is one way to do it so + + + align:start position:0% +solution this is one way to do it so +we're just adding n over all here + + align:start position:0% +we're just adding n over all here + + + align:start position:0% +we're just adding n over all here +because we have 3 * n over3 and that + + align:start position:0% +because we have 3 * n over3 and that + + + align:start position:0% +because we have 3 * n over3 and that +guarant and uh you know the length of + + align:start position:0% +guarant and uh you know the length of + + + align:start position:0% +guarant and uh you know the length of +these is always + + align:start position:0% +these is always + + + align:start position:0% +these is always +uh + + align:start position:0% +uh + + + align:start position:0% +uh +smaller uh yeah rotation should not be + + align:start position:0% +smaller uh yeah rotation should not be + + + align:start position:0% +smaller uh yeah rotation should not be +possible right because each of these + + align:start position:0% +possible right because each of these + + + align:start position:0% +possible right because each of these +guys is going to be length strictly + + align:start position:0% +guys is going to be length strictly + + + align:start position:0% +guys is going to be length strictly +larger than n over3 because we add an + + align:start position:0% +larger than n over3 because we add an + + + align:start position:0% +larger than n over3 because we add an +integer to n a positive integer and the + + align:start position:0% +integer to n a positive integer and the + + + align:start position:0% +integer to n a positive integer and the +height here is N3 so that just barely + + align:start position:0% +height here is N3 so that just barely + + + align:start position:0% +height here is N3 so that just barely +works same thing more or less just this + + align:start position:0% +works same thing more or less just this + + + align:start position:0% +works same thing more or less just this +is scaling by a multiplicative Factor + + align:start position:0% +is scaling by a multiplicative Factor + + + align:start position:0% +is scaling by a multiplicative Factor +here we're doing an additive thing + + align:start position:0% +here we're doing an additive thing + + + align:start position:0% +here we're doing an additive thing +because we have this luxury of knowing + + align:start position:0% +because we have this luxury of knowing + + + align:start position:0% +because we have this luxury of knowing +there are three items in every + + align:start position:0% +there are three items in every + + + align:start position:0% +there are three items in every +triple cool rectangle packing question + + align:start position:0% +triple cool rectangle packing question + + + align:start position:0% +triple cool rectangle packing question +uh there's a question about three + + align:start position:0% +uh there's a question about three + + + align:start position:0% +uh there's a question about three +partition is it assumed that they're + + align:start position:0% +partition is it assumed that they're + + + align:start position:0% +partition is it assumed that they're +positive integers yes sorry all the + + align:start position:0% +positive integers yes sorry all the + + + align:start position:0% +positive integers yes sorry all the +integers are + + align:start position:0% + + + + align:start position:0% + +positive yeah I you don't have to but we + + align:start position:0% +positive yeah I you don't have to but we + + + align:start position:0% +positive yeah I you don't have to but we +can so we will + + align:start position:0% +can so we will + + + align:start position:0% +can so we will +makes our life a lot + + align:start position:0% +makes our life a lot + + + align:start position:0% +makes our life a lot +easier other + + align:start position:0% + + + + align:start position:0% + +questions okay + + align:start position:0% +questions okay + + + align:start position:0% +questions okay +uh time for some + + align:start position:0% +uh time for some + + + align:start position:0% +uh time for some +puzzles uh so I think I'll show you some + + align:start position:0% +puzzles uh so I think I'll show you some + + + align:start position:0% +puzzles uh so I think I'll show you some +real life puzzles first um there's this + + align:start position:0% +real life puzzles first um there's this + + + align:start position:0% +real life puzzles first um there's this +notion of an edge matching puzzle which + + align:start position:0% +notion of an edge matching puzzle which + + + align:start position:0% +notion of an edge matching puzzle which +goes back to the + + align:start position:0% +goes back to the + + + align:start position:0% +goes back to the +1890s I believe this one is from late + + align:start position:0% +1890s I believe this one is from late + + + align:start position:0% +1890s I believe this one is from late +1890s early 1900s so it's one of the + + align:start position:0% +1890s early 1900s so it's one of the + + + align:start position:0% +1890s early 1900s so it's one of the +older ones you prob at least when I was + + align:start position:0% +older ones you prob at least when I was + + + align:start position:0% +older ones you prob at least when I was +growing up we had these puzzles all over + + align:start position:0% +growing up we had these puzzles all over + + + align:start position:0% +growing up we had these puzzles all over +the place uh so what's going on here is + + align:start position:0% +the place uh so what's going on here is + + + align:start position:0% +the place uh so what's going on here is +you have physical triangles and these + + align:start position:0% +you have physical triangles and these + + + align:start position:0% +you have physical triangles and these +half frogs are drawn on the edges of the + + align:start position:0% +half frogs are drawn on the edges of the + + + align:start position:0% +half frogs are drawn on the edges of the +triangles and your goal is to pack all + + align:start position:0% +triangles and your goal is to pack all + + + align:start position:0% +triangles and your goal is to pack all +these triangles into the big triangle + + align:start position:0% +these triangles into the big triangle + + + align:start position:0% +these triangles into the big triangle +that's easy it's a regular triang uh uh + + align:start position:0% +that's easy it's a regular triang uh uh + + + align:start position:0% +that's easy it's a regular triang uh uh +triangulation but you need the half + + align:start position:0% +triangulation but you need the half + + + align:start position:0% +triangulation but you need the half +frogs to match up the B the the I don't + + align:start position:0% +frogs to match up the B the the I don't + + + align:start position:0% +frogs to match up the B the the I don't +know the the behind end of the white + + align:start position:0% +know the the behind end of the white + + + align:start position:0% +know the the behind end of the white +sorry yellow speckled frog matches the + + align:start position:0% +sorry yellow speckled frog matches the + + + align:start position:0% +sorry yellow speckled frog matches the +front end of the yellow black speckled + + align:start position:0% +front end of the yellow black speckled + + + align:start position:0% +front end of the yellow black speckled +frog as drawn here this is a valid + + align:start position:0% +frog as drawn here this is a valid + + + align:start position:0% +frog as drawn here this is a valid +solution but if I like rotated this tile + + align:start position:0% +solution but if I like rotated this tile + + + align:start position:0% +solution but if I like rotated this tile +120 degrees that's not a valid solution + + align:start position:0% +120 degrees that's not a valid solution + + + align:start position:0% +120 degrees that's not a valid solution +um even though it's all Hinds matching + + align:start position:0% +um even though it's all Hinds matching + + + align:start position:0% +um even though it's all Hinds matching +to fronts and so on okay rules clear uh + + align:start position:0% +to fronts and so on okay rules clear uh + + + align:start position:0% +to fronts and so on okay rules clear uh +so these are Edge matching puzzles this + + align:start position:0% +so these are Edge matching puzzles this + + + align:start position:0% +so these are Edge matching puzzles this +is formulated in a different way this is + + align:start position:0% +is formulated in a different way this is + + + align:start position:0% +is formulated in a different way this is +not a valid solution the goal is to get + + align:start position:0% +not a valid solution the goal is to get + + + align:start position:0% +not a valid solution the goal is to get +these colors to all match up so in + + align:start position:0% +these colors to all match up so in + + + align:start position:0% +these colors to all match up so in +general you can think of there being a + + align:start position:0% +general you can think of there being a + + + align:start position:0% +general you can think of there being a +color on an edge um and here it happens + + align:start position:0% +color on an edge um and here it happens + + + align:start position:0% +color on an edge um and here it happens +to be composed of these two colors and + + align:start position:0% +to be composed of these two colors and + + + align:start position:0% +to be composed of these two colors and +it have to match both of the colors on + + align:start position:0% +it have to match both of the colors on + + + align:start position:0% +it have to match both of the colors on +the other side so this essentially like + + align:start position:0% +the other side so this essentially like + + + align:start position:0% +the other side so this essentially like +having a color on each edge here we also + + align:start position:0% +having a color on each edge here we also + + + align:start position:0% +having a color on each edge here we also +have a color on each Edge but we also + + align:start position:0% +have a color on each Edge but we also + + + align:start position:0% +have a color on each Edge but we also +have a sign uh which is the front or the + + align:start position:0% +have a sign uh which is the front or the + + + align:start position:0% +have a sign uh which is the front or the +hind part of the Frog there you know the + + align:start position:0% +hind part of the Frog there you know the + + + align:start position:0% +hind part of the Frog there you know the +yellow frog the Red Frog the green frog + + align:start position:0% +yellow frog the Red Frog the green frog + + + align:start position:0% +yellow frog the Red Frog the green frog +the orange frog um so in general we're + + align:start position:0% +the orange frog um so in general we're + + + align:start position:0% +the orange frog um so in general we're +going to formulate this + + align:start position:0% +going to formulate this + + + align:start position:0% +going to formulate this +uh be over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +okay there are many types of these + + align:start position:0% +okay there are many types of these + + + align:start position:0% +okay there are many types of these +puzzles um I'll try to + + align:start position:0% +puzzles um I'll try to + + + align:start position:0% +puzzles um I'll try to +capture that's not exactly either one of + + align:start position:0% +capture that's not exactly either one of + + + align:start position:0% +capture that's not exactly either one of +those + + align:start position:0% + + + + align:start position:0% + +um if you've ever studied something + + align:start position:0% +um if you've ever studied something + + + align:start position:0% +um if you've ever studied something +called Wang tiles uh this is exactly + + align:start position:0% +called Wang tiles uh this is exactly + + + align:start position:0% +called Wang tiles uh this is exactly +that + + align:start position:0% + + + + align:start position:0% + +model just throw in the word there but + + align:start position:0% +model just throw in the word there but + + + align:start position:0% +model just throw in the word there but +uh what we have are n uh unit + + align:start position:0% +uh what we have are n uh unit + + + align:start position:0% +uh what we have are n uh unit +squares those are called the + + align:start position:0% + + + + align:start position:0% + +tiles each + + align:start position:0% +tiles each + + + align:start position:0% +tiles each +one has four colors uh a b c + + align:start position:0% +one has four colors uh a b c + + + align:start position:0% +one has four colors uh a b c +d + + align:start position:0% +d + + + align:start position:0% +d +so + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +one color per + + align:start position:0% + + + + align:start position:0% + +inedge + + align:start position:0% +inedge + + + align:start position:0% +inedge +and okay you're also given a Target + + align:start position:0% +and okay you're also given a Target + + + align:start position:0% +and okay you're also given a Target +rectangle it's going to be integer + + align:start position:0% +rectangle it's going to be integer + + + align:start position:0% +rectangle it's going to be integer +because these are unit + + align:start position:0% + + + + align:start position:0% + +squares and you want + + align:start position:0% +squares and you want + + + align:start position:0% +squares and you want +to pack probably exactly pack there's + + align:start position:0% +to pack probably exactly pack there's + + + align:start position:0% +to pack probably exactly pack there's +not going to be any gaps uh the squares + + align:start position:0% +not going to be any gaps uh the squares + + + align:start position:0% +not going to be any gaps uh the squares +into the + + align:start position:0% +into the + + + align:start position:0% +into the +rectangle + + align:start position:0% +rectangle + + + align:start position:0% +rectangle +um with colors + + align:start position:0% + + + + align:start position:0% + +matching so whenever I have two + + align:start position:0% +matching so whenever I have two + + + align:start position:0% +matching so whenever I have two +squares that share an edge the color + + align:start position:0% +squares that share an edge the color + + + align:start position:0% +squares that share an edge the color +that's written here better be the same + + align:start position:0% +that's written here better be the same + + + align:start position:0% +that's written here better be the same +color that's written there that's the + + align:start position:0% +color that's written there that's the + + + align:start position:0% +color that's written there that's the +rules if you're on the boundary no + + align:start position:0% +rules if you're on the boundary no + + + align:start position:0% +rules if you're on the boundary no +restriction but if you're an interior + + align:start position:0% +restriction but if you're an interior + + + align:start position:0% +restriction but if you're an interior +Edge you restrict in that way okay uh + + align:start position:0% +Edge you restrict in that way okay uh + + + align:start position:0% +Edge you restrict in that way okay uh +this actually closely matches what is + + align:start position:0% +this actually closely matches what is + + + align:start position:0% +this actually closely matches what is +currently maybe the most famous Edge + + align:start position:0% +currently maybe the most famous Edge + + + align:start position:0% +currently maybe the most famous Edge +matching puzzle called eternity 2 uh + + align:start position:0% +matching puzzle called eternity 2 uh + + + align:start position:0% +matching puzzle called eternity 2 uh +this one is still unsolved well the + + align:start position:0% +this one is still unsolved well the + + + align:start position:0% +this one is still unsolved well the +creator has a solution and if you ever + + align:start position:0% +creator has a solution and if you ever + + + align:start position:0% +creator has a solution and if you ever +find it or one of the many other + + align:start position:0% +find it or one of the many other + + + align:start position:0% +find it or one of the many other +Solutions who knows you will win $2 + + align:start position:0% +Solutions who knows you will win $2 + + + align:start position:0% +Solutions who knows you will win $2 +million us so time to get + + align:start position:0% + + + + align:start position:0% + +rich well yeah I guess that's the way to + + align:start position:0% +rich well yeah I guess that's the way to + + + align:start position:0% +rich well yeah I guess that's the way to +make the most money is first solve P + + align:start position:0% +make the most money is first solve P + + + align:start position:0% +make the most money is first solve P +equals NP then solve eternity 2 I guess + + align:start position:0% +equals NP then solve eternity 2 I guess + + + align:start position:0% +equals NP then solve eternity 2 I guess +uh but you could easily solve this + + align:start position:0% +uh but you could easily solve this + + + align:start position:0% +uh but you could easily solve this +puzzle without uh P NP there actually a + + align:start position:0% +puzzle without uh P NP there actually a + + + align:start position:0% +puzzle without uh P NP there actually a +lot of almost Solutions out there uh I + + align:start position:0% +lot of almost Solutions out there uh I + + + align:start position:0% +lot of almost Solutions out there uh I +believe this is uh one of the leaders uh + + align:start position:0% +believe this is uh one of the leaders uh + + + align:start position:0% +believe this is uh one of the leaders uh +this guy leis verad um got so this is a + + align:start position:0% +this guy leis verad um got so this is a + + + align:start position:0% +this guy leis verad um got so this is a +complete solution with all the pieces uh + + align:start position:0% +complete solution with all the pieces uh + + + align:start position:0% +complete solution with all the pieces uh +but not all the edges match so it's hard + + align:start position:0% +but not all the edges match so it's hard + + + align:start position:0% +but not all the edges match so it's hard +to find them but here's one for example + + align:start position:0% +to find them but here's one for example + + + align:start position:0% +to find them but here's one for example +that mismatches so I didn't explain but + + align:start position:0% +that mismatches so I didn't explain but + + + align:start position:0% +that mismatches so I didn't explain but +there everything is a Square Tile here + + align:start position:0% +there everything is a Square Tile here + + + align:start position:0% +there everything is a Square Tile here +and there's a different shape and color + + align:start position:0% +and there's a different shape and color + + + align:start position:0% +and there's a different shape and color +but it's basically a color from + + align:start position:0% +but it's basically a color from + + + align:start position:0% +but it's basically a color from +mathematical perspective got a all up + + align:start position:0% +mathematical perspective got a all up + + + align:start position:0% +mathematical perspective got a all up +here he got 467 matches out of the 480 + + align:start position:0% +here he got 467 matches out of the 480 + + + align:start position:0% +here he got 467 matches out of the 480 +edges and that won him already + + align:start position:0% +edges and that won him already + + + align:start position:0% +edges and that won him already +$10,000 and I believe it's found uh with + + align:start position:0% +$10,000 and I believe it's found uh with + + + align:start position:0% +$10,000 and I believe it's found uh with +computer a search uh got software that's + + align:start position:0% +computer a search uh got software that's + + + align:start position:0% +computer a search uh got software that's +not the person I I I don't know for sure + + align:start position:0% +not the person I I I don't know for sure + + + align:start position:0% +not the person I I I don't know for sure +uh I would guess that it's Louis's + + align:start position:0% +uh I would guess that it's Louis's + + + align:start position:0% +uh I would guess that it's Louis's +daughter um here's a different almost + + align:start position:0% +daughter um here's a different almost + + + align:start position:0% +daughter um here's a different almost +solution where there's some missing + + align:start position:0% +solution where there's some missing + + + align:start position:0% +solution where there's some missing +tiles but everything matches and then at + + align:start position:0% +tiles but everything matches and then at + + + align:start position:0% +tiles but everything matches and then at +the bottom of his web page you should + + align:start position:0% +the bottom of his web page you should + + + align:start position:0% +the bottom of his web page you should +check it out it's fun he says and here's + + align:start position:0% +check it out it's fun he says and here's + + + align:start position:0% +check it out it's fun he says and here's +a solution to Trinity 2 and I looked at + + align:start position:0% +a solution to Trinity 2 and I looked at + + + align:start position:0% +a solution to Trinity 2 and I looked at +this for a long time it's like I don't + + align:start position:0% +this for a long time it's like I don't + + + align:start position:0% +this for a long time it's like I don't +see any Edge matches uh but you guys are + + align:start position:0% +see any Edge matches uh but you guys are + + + align:start position:0% +see any Edge matches uh but you guys are +smart so you probably know uh there's + + align:start position:0% +smart so you probably know uh there's + + + align:start position:0% +smart so you probably know uh there's +one other cheat you could possibly do in + + align:start position:0% +one other cheat you could possibly do in + + + align:start position:0% +one other cheat you could possibly do in +this + + align:start position:0% +this + + + align:start position:0% +this +puzzle maybe add a different add + + align:start position:0% +puzzle maybe add a different add + + + align:start position:0% +puzzle maybe add a different add +different tiles maybe although these are + + align:start position:0% +different tiles maybe although these are + + + align:start position:0% +different tiles maybe although these are +nicely printed tiles so I would guess he + + align:start position:0% +nicely printed tiles so I would guess he + + + align:start position:0% +nicely printed tiles so I would guess he +bought two + + align:start position:0% +bought two + + + align:start position:0% +bought two +sets uh and he's mixed some parts I + + align:start position:0% +sets uh and he's mixed some parts I + + + align:start position:0% +sets uh and he's mixed some parts I +wrote a program to check yes indeed some + + align:start position:0% +wrote a program to check yes indeed some + + + align:start position:0% +wrote a program to check yes indeed some +tiles are repeated here I forget exactly + + align:start position:0% +tiles are repeated here I forget exactly + + + align:start position:0% +tiles are repeated here I forget exactly +how many 10 or 20 or something it's + + align:start position:0% +how many 10 or 20 or something it's + + + align:start position:0% +how many 10 or 20 or something it's +still pretty cool it looks like it's + + align:start position:0% +still pretty cool it looks like it's + + + align:start position:0% +still pretty cool it looks like it's +done but there's no complete actual + + align:start position:0% +done but there's no complete actual + + + align:start position:0% +done but there's no complete actual +solution using each piece exactly once + + align:start position:0% +solution using each piece exactly once + + + align:start position:0% +solution using each piece exactly once +uh it's probably clear here but you only + + align:start position:0% +uh it's probably clear here but you only + + + align:start position:0% +uh it's probably clear here but you only +get one version of each + + align:start position:0% + + + + align:start position:0% + +Square okay uh so there's your + + align:start position:0% +Square okay uh so there's your + + + align:start position:0% +Square okay uh so there's your +motivation for solving Edge matching so + + align:start position:0% +motivation for solving Edge matching so + + + align:start position:0% +motivation for solving Edge matching so +you might wonder oh can I solve it in + + align:start position:0% +you might wonder oh can I solve it in + + + align:start position:0% +you might wonder oh can I solve it in +polinomial time and the answer is no + + align:start position:0% +polinomial time and the answer is no + + + align:start position:0% +polinomial time and the answer is no +unless P equals NP um and here we're + + align:start position:0% +unless P equals NP um and here we're + + + align:start position:0% +unless P equals NP um and here we're +going to use essentially rectangle p + + align:start position:0% +going to use essentially rectangle p + + + align:start position:0% +going to use essentially rectangle p +packing and this + + align:start position:0% +packing and this + + + align:start position:0% +packing and this +reduction so how could I how could I + + align:start position:0% +reduction so how could I how could I + + + align:start position:0% +reduction so how could I how could I +again we're going to reduce from three + + align:start position:0% +again we're going to reduce from three + + + align:start position:0% +again we're going to reduce from three +partition how could I convert a number + + align:start position:0% +partition how could I convert a number + + + align:start position:0% +partition how could I convert a number +AI into something like a rectangle using + + align:start position:0% +AI into something like a rectangle using + + + align:start position:0% +AI into something like a rectangle using +Edge + + align:start position:0% + + + + align:start position:0% + +matching uh I should probably copy over + + align:start position:0% +matching uh I should probably copy over + + + align:start position:0% +matching uh I should probably copy over +the one that we had in the end which was + + align:start position:0% +the one that we had in the end which was + + + align:start position:0% +the one that we had in the end which was +AI goes + + align:start position:0% +AI goes + + + align:start position:0% +AI goes +to uh n /3 + AI by 1 cuz we want + + align:start position:0% + + + + align:start position:0% + +integers yeah so um you make it so that + + align:start position:0% +integers yeah so um you make it so that + + + align:start position:0% +integers yeah so um you make it so that +there's sort of one color that's for + + align:start position:0% +there's sort of one color that's for + + + align:start position:0% +there's sort of one color that's for +joining most things and that that's + + align:start position:0% +joining most things and that that's + + + align:start position:0% +joining most things and that that's +going to go kind of on the outside of + + align:start position:0% +going to go kind of on the outside of + + + align:start position:0% +going to go kind of on the outside of +each rectangle we going to put together + + align:start position:0% +each rectangle we going to put together + + + align:start position:0% +each rectangle we going to put together +each rectangle if you need like if if + + align:start position:0% +each rectangle if you need like if if + + + align:start position:0% +each rectangle if you need like if if +the rectangle is like a I by 1 then + + align:start position:0% +the rectangle is like a I by 1 then + + + align:start position:0% +the rectangle is like a I by 1 then +you're going to need AI squares such + + align:start position:0% +you're going to need AI squares such + + + align:start position:0% +you're going to need AI squares such +that there's like one color for that + + align:start position:0% +that there's like one color for that + + + align:start position:0% +that there's like one color for that +rectangle that is only + + align:start position:0% +rectangle that is only + + + align:start position:0% +rectangle that is only +used to join together squ of that + + align:start position:0% +used to join together squ of that + + + align:start position:0% +used to join together squ of that +rectangle good so we're going to convert + + align:start position:0% +rectangle good so we're going to convert + + + align:start position:0% +rectangle good so we're going to convert +this something by one rectangle into + + align:start position:0% +this something by one rectangle into + + + align:start position:0% +this something by one rectangle into +that into something different squares + + align:start position:0% +that into something different squares + + + align:start position:0% +that into something different squares +that's and we're just going to subdivide + + align:start position:0% +that's and we're just going to subdivide + + + align:start position:0% +that's and we're just going to subdivide +like that and we're going to surround + + align:start position:0% +like that and we're going to surround + + + align:start position:0% +like that and we're going to surround +all these uh edges with the same + + align:start position:0% + + + + align:start position:0% + +color uh that will work and the interior + + align:start position:0% +color uh that will work and the interior + + + align:start position:0% +color uh that will work and the interior +edes the interior edges all right so + + align:start position:0% +edes the interior edges all right so + + + align:start position:0% +edes the interior edges all right so +we're going to take Ai and we're going + + align:start position:0% +we're going to take Ai and we're going + + + align:start position:0% +we're going to take Ai and we're going +to convert it + + align:start position:0% +to convert it + + + align:start position:0% +to convert it +into + + align:start position:0% + + + + align:start position:0% + +uh okay don't make me draw all of them + + align:start position:0% +uh okay don't make me draw all of them + + + align:start position:0% +uh okay don't make me draw all of them +um the width here let's say it'll be n + + align:start position:0% +um the width here let's say it'll be n + + + align:start position:0% +um the width here let's say it'll be n +over3 plus + + align:start position:0% +over3 plus + + + align:start position:0% +over3 plus +AI uh and we're going to use a special + + align:start position:0% +AI uh and we're going to use a special + + + align:start position:0% +AI uh and we're going to use a special +color I'll call it black on the outside + + align:start position:0% +color I'll call it black on the outside + + + align:start position:0% +color I'll call it black on the outside +and this color I'm going to call these + + align:start position:0% +and this color I'm going to call these + + + align:start position:0% +and this color I'm going to call these +red so it's slightly visible I'm gonna + + align:start position:0% +red so it's slightly visible I'm gonna + + + align:start position:0% +red so it's slightly visible I'm gonna +call I this is going to be a different + + align:start position:0% +call I this is going to be a different + + + align:start position:0% +call I this is going to be a different +color for + + align:start position:0% +color for + + + align:start position:0% +color for +um each + + align:start position:0% + + + + align:start position:0% + +AI That's um this will require a little + + align:start position:0% +AI That's um this will require a little + + + align:start position:0% +AI That's um this will require a little +bit more work you could also use a + + align:start position:0% +bit more work you could also use a + + + align:start position:0% +bit more work you could also use a +different you could use i1 I2 I3 that + + align:start position:0% +different you could use i1 I2 I3 that + + + align:start position:0% +different you could use i1 I2 I3 that +would really Force this to go together + + align:start position:0% +would really Force this to go together + + + align:start position:0% +would really Force this to go together +in this way um if I'm a little if I'm + + align:start position:0% +in this way um if I'm a little if I'm + + + align:start position:0% +in this way um if I'm a little if I'm +trying to be conservative on colors I + + align:start position:0% +trying to be conservative on colors I + + + align:start position:0% +trying to be conservative on colors I +only use n of them um then I will put + + align:start position:0% +only use n of them um then I will put + + + align:start position:0% +only use n of them um then I will put +those all I and then is long as none of + + align:start position:0% +those all I and then is long as none of + + + align:start position:0% +those all I and then is long as none of +these match to the boundary I'm + + align:start position:0% +these match to the boundary I'm + + + align:start position:0% +these match to the boundary I'm +okay uh I guess even if I use the i1 I2 + + align:start position:0% +okay uh I guess even if I use the i1 I2 + + + align:start position:0% +okay uh I guess even if I use the i1 I2 +I3 it's possible some of those match the + + align:start position:0% +I3 it's possible some of those match the + + + align:start position:0% +I3 it's possible some of those match the +boundary and then weird stuff could + + align:start position:0% +boundary and then weird stuff could + + + align:start position:0% +boundary and then weird stuff could +happen but as long as all these eye + + align:start position:0% +happen but as long as all these eye + + + align:start position:0% +happen but as long as all these eye +colors match up with each other you have + + align:start position:0% +colors match up with each other you have + + + align:start position:0% +colors match up with each other you have +to build this rectangle once and then we + + align:start position:0% +to build this rectangle once and then we + + + align:start position:0% +to build this rectangle once and then we +don't care about how the rectangles are + + align:start position:0% +don't care about how the rectangles are + + + align:start position:0% +don't care about how the rectangles are +assembled with respect to each other uh + + align:start position:0% +assembled with respect to each other uh + + + align:start position:0% +assembled with respect to each other uh +so we're basically simulating this + + align:start position:0% +so we're basically simulating this + + + align:start position:0% +so we're basically simulating this +reduction rectangle + + align:start position:0% +reduction rectangle + + + align:start position:0% +reduction rectangle +packing okay the one I have drawn here + + align:start position:0% +packing okay the one I have drawn here + + + align:start position:0% +packing okay the one I have drawn here +is slightly different um I don't + + align:start position:0% +is slightly different um I don't + + + align:start position:0% +is slightly different um I don't +remember why we did it this way this is + + align:start position:0% +remember why we did it this way this is + + + align:start position:0% +remember why we did it this way this is +Joint work with Marty domain the + + align:start position:0% +Joint work with Marty domain the + + + align:start position:0% +Joint work with Marty domain the +cameraman and and uh here uh we made the + + align:start position:0% +cameraman and and uh here uh we made the + + + align:start position:0% +cameraman and and uh here uh we made the +just I guess to be as simple as possible + + align:start position:0% +just I guess to be as simple as possible + + + align:start position:0% +just I guess to be as simple as possible +we made the width of each of the + + align:start position:0% +we made the width of each of the + + + align:start position:0% +we made the width of each of the +rectangles just + + align:start position:0% +rectangles just + + + align:start position:0% +rectangles just +AI that has the problem that you could + + align:start position:0% +AI that has the problem that you could + + + align:start position:0% +AI that has the problem that you could +rotate but to prevent rotation we use a + + align:start position:0% +rotate but to prevent rotation we use a + + + align:start position:0% +rotate but to prevent rotation we use a +different color horizontal and vertical + + align:start position:0% +different color horizontal and vertical + + + align:start position:0% +different color horizontal and vertical +so the top edges and the bottom edges + + align:start position:0% +so the top edges and the bottom edges + + + align:start position:0% +so the top edges and the bottom edges +all have the color percent sign uh I + + align:start position:0% +all have the color percent sign uh I + + + align:start position:0% +all have the color percent sign uh I +think this is a limitation of the + + align:start position:0% +think this is a limitation of the + + + align:start position:0% +think this is a limitation of the +drawing program I was using at the time + + align:start position:0% +drawing program I was using at the time + + + align:start position:0% +drawing program I was using at the time +xfig and dollar signs on the left and + + align:start position:0% +xfig and dollar signs on the left and + + + align:start position:0% +xfig and dollar signs on the left and +right side and then we're going to build + + align:start position:0% +right side and then we're going to build + + + align:start position:0% +right side and then we're going to build +frame this is what you might call + + align:start position:0% +frame this is what you might call + + + align:start position:0% +frame this is what you might call +infrastructure for the proof this is one + + align:start position:0% +infrastructure for the proof this is one + + + align:start position:0% +infrastructure for the proof this is one +Gadget happens you just execute it once + + align:start position:0% +Gadget happens you just execute it once + + + align:start position:0% +Gadget happens you just execute it once +this we execute for each of the AIS + + align:start position:0% +this we execute for each of the AIS + + + align:start position:0% +this we execute for each of the AIS +we're just going to have one copy of + + align:start position:0% +we're just going to have one copy of + + + align:start position:0% +we're just going to have one copy of +this big frame the goal of the frame is + + align:start position:0% +this big frame the goal of the frame is + + + align:start position:0% +this big frame the goal of the frame is +to hide the + + align:start position:0% +to hide the + + + align:start position:0% +to hide the +boundary uh so that none of these tiles + + align:start position:0% +boundary uh so that none of these tiles + + + align:start position:0% +boundary uh so that none of these tiles +could match with the boundary because + + align:start position:0% +could match with the boundary because + + + align:start position:0% +could match with the boundary because +when they match the boundary then you're + + align:start position:0% +when they match the boundary then you're + + + align:start position:0% +when they match the boundary then you're +breaking a rectangle in half and bad + + align:start position:0% +breaking a rectangle in half and bad + + + align:start position:0% +breaking a rectangle in half and bad +things could happen so instead uh what + + align:start position:0% +things could happen so instead uh what + + + align:start position:0% +things could happen so instead uh what +we're going to do all these capital + + align:start position:0% +we're going to do all these capital + + + align:start position:0% +we're going to do all these capital +letters on the outside and I ran out of + + align:start position:0% +letters on the outside and I ran out of + + + align:start position:0% +letters on the outside and I ran out of +letters I used a couple symbols those + + align:start position:0% +letters I used a couple symbols those + + + align:start position:0% +letters I used a couple symbols those +appear exactly once in the reduction so + + align:start position:0% +appear exactly once in the reduction so + + + align:start position:0% +appear exactly once in the reduction so +they can't match with anyone which means + + align:start position:0% +they can't match with anyone which means + + + align:start position:0% +they can't match with anyone which means +they have to be on the boundary + + align:start position:0% +they have to be on the boundary + + + align:start position:0% +they have to be on the boundary +okay so those guys have to be on the + + align:start position:0% +okay so those guys have to be on the + + + align:start position:0% +okay so those guys have to be on the +boundary um and then all these other + + align:start position:0% +boundary um and then all these other + + + align:start position:0% +boundary um and then all these other +colors are appear exactly twice so you + + align:start position:0% +colors are appear exactly twice so you + + + align:start position:0% +colors are appear exactly twice so you +have to join these tiles together in + + align:start position:0% +have to join these tiles together in + + + align:start position:0% +have to join these tiles together in +exactly this way uh and now the + + align:start position:0% +exactly this way uh and now the + + + align:start position:0% +exactly this way uh and now the +boundary's gone and we have set up + + align:start position:0% +boundary's gone and we have set up + + + align:start position:0% +boundary's gone and we have set up +dollar signs on the left side and the + + align:start position:0% +dollar signs on the left side and the + + + align:start position:0% +dollar signs on the left side and the +right side and percent signs on the top + + align:start position:0% +right side and percent signs on the top + + + align:start position:0% +right side and percent signs on the top +and the bottom sides uh in reality these + + align:start position:0% +and the bottom sides uh in reality these + + + align:start position:0% +and the bottom sides uh in reality these +would be uh whatever + + align:start position:0% +would be uh whatever + + + align:start position:0% +would be uh whatever +t uh wide and N over3 tall uh this is + + align:start position:0% +t uh wide and N over3 tall uh this is + + + align:start position:0% +t uh wide and N over3 tall uh this is +some different notation + + align:start position:0% +some different notation + + + align:start position:0% +some different notation +and uh that's it now you're simulating + + align:start position:0% +and uh that's it now you're simulating + + + align:start position:0% +and uh that's it now you're simulating +rectangle packing question why do you + + align:start position:0% +rectangle packing question why do you + + + align:start position:0% +rectangle packing question why do you +need two rows at the bottom ah so this + + align:start position:0% +need two rows at the bottom ah so this + + + align:start position:0% +need two rows at the bottom ah so this +two rows is to indicate uh for whatever + + align:start position:0% +two rows is to indicate uh for whatever + + + align:start position:0% +two rows is to indicate uh for whatever +reason because Edge matching puzzles + + align:start position:0% +reason because Edge matching puzzles + + + align:start position:0% +reason because Edge matching puzzles +usually the target shape is not a + + align:start position:0% +usually the target shape is not a + + + align:start position:0% +usually the target shape is not a +rectangle but a square and we wanted the + + align:start position:0% +rectangle but a square and we wanted the + + + align:start position:0% +rectangle but a square and we wanted the +stronger result that packing unit + + align:start position:0% +stronger result that packing unit + + + align:start position:0% +stronger result that packing unit +squares into a square with Edge matching + + align:start position:0% +squares into a square with Edge matching + + + align:start position:0% +squares into a square with Edge matching +results is NP hard uh so we just the + + align:start position:0% +results is NP hard uh so we just the + + + align:start position:0% +results is NP hard uh so we just the +point here is you just add however many + + align:start position:0% +point here is you just add however many + + + align:start position:0% +point here is you just add however many +rows or columns you need to make s y + + align:start position:0% +rows or columns you need to make s y + + + align:start position:0% +rows or columns you need to make s y +good question Jason so your different + + align:start position:0% +good question Jason so your different + + + align:start position:0% +good question Jason so your different +symbols I believe are also to let you + + align:start position:0% +symbols I believe are also to let you + + + align:start position:0% +symbols I believe are also to let you +build this in the rectangle later on + + align:start position:0% +build this in the rectangle later on + + + align:start position:0% +build this in the rectangle later on +otherwise we issues with rotating + + align:start position:0% +otherwise we issues with rotating + + + align:start position:0% +otherwise we issues with rotating +things we'll get there at this yeah so I + + align:start position:0% +things we'll get there at this yeah so I + + + align:start position:0% +things we'll get there at this yeah so I +have different symbols here and here in + + align:start position:0% +have different symbols here and here in + + + align:start position:0% +have different symbols here and here in +order to prevent rotation that's right + + align:start position:0% +order to prevent rotation that's right + + + align:start position:0% +order to prevent rotation that's right +instead of making them longer I could + + align:start position:0% +instead of making them longer I could + + + align:start position:0% +instead of making them longer I could +have instead made these longer like we + + align:start position:0% +have instead made these longer like we + + + align:start position:0% +have instead made these longer like we +had with the rectangle thing but uh I + + align:start position:0% +had with the rectangle thing but uh I + + + align:start position:0% +had with the rectangle thing but uh I +guess at the time I wasn't thinking of + + align:start position:0% +guess at the time I wasn't thinking of + + + align:start position:0% +guess at the time I wasn't thinking of +teaching in class about this so I didn't + + align:start position:0% +teaching in class about this so I didn't + + + align:start position:0% +teaching in class about this so I didn't +reuse my previous reduction for this one + + align:start position:0% +reuse my previous reduction for this one + + + align:start position:0% +reuse my previous reduction for this one +but oh well um + + align:start position:0% +but oh well um + + + align:start position:0% +but oh well um +yeah but uh yeah the the reason they + + align:start position:0% +yeah but uh yeah the the reason they + + + align:start position:0% +yeah but uh yeah the the reason they +dollar signs in that like + + align:start position:0% +dollar signs in that like + + + align:start position:0% +dollar signs in that like +red or some actual color is because uh + + align:start position:0% +red or some actual color is because uh + + + align:start position:0% +red or some actual color is because uh +yeah probably black and white printing + + align:start position:0% +yeah probably black and white printing + + + align:start position:0% +yeah probably black and white printing +was more common + + align:start position:0% +was more common + + + align:start position:0% +was more common +then + + align:start position:0% +then + + + align:start position:0% +then +okay cool that was one puzzle and now + + align:start position:0% +okay cool that was one puzzle and now + + + align:start position:0% +okay cool that was one puzzle and now +key Point what if we did this reduction + + align:start position:0% +key Point what if we did this reduction + + + align:start position:0% +key Point what if we did this reduction +from + + align:start position:0% +from + + + align:start position:0% +from +partition so with Partition instead of + + align:start position:0% +partition so with Partition instead of + + + align:start position:0% +partition so with Partition instead of +having n over3 groups here we just have + + align:start position:0% +having n over3 groups here we just have + + + align:start position:0% +having n over3 groups here we just have +two groups and same thing why not do + + align:start position:0% +two groups and same thing why not do + + + align:start position:0% +two groups and same thing why not do +that and it would be a + + align:start position:0% +that and it would be a + + + align:start position:0% +that and it would be a +week that would be a weekend be hard + + align:start position:0% +week that would be a weekend be hard + + + align:start position:0% +week that would be a weekend be hard +reduction now uh this problem here Edge + + align:start position:0% +reduction now uh this problem here Edge + + + align:start position:0% +reduction now uh this problem here Edge +matching puzzle n unit squares with four + + align:start position:0% +matching puzzle n unit squares with four + + + align:start position:0% +matching puzzle n unit squares with four +colors are there any numbers in this + + align:start position:0% +colors are there any numbers in this + + + align:start position:0% +colors are there any numbers in this +problem other than + + align:start position:0% +problem other than + + + align:start position:0% +problem other than +four and + + align:start position:0% +four and + + + align:start position:0% +four and +N are there any numbers that are inputs + + align:start position:0% +N are there any numbers that are inputs + + + align:start position:0% +N are there any numbers that are inputs +I guess the colors have to be + + align:start position:0% +I guess the colors have to be + + + align:start position:0% +I guess the colors have to be +represented as numbers the colors do + + align:start position:0% +represented as numbers the colors do + + + align:start position:0% +represented as numbers the colors do +have to be represented as numbers but um + + align:start position:0% +have to be represented as numbers but um + + + align:start position:0% +have to be represented as numbers but um +so this is sort of a Seline usually we + + align:start position:0% +so this is sort of a Seline usually we + + + align:start position:0% +so this is sort of a Seline usually we +when we're talking about colors all we + + align:start position:0% +when we're talking about colors all we + + + align:start position:0% +when we're talking about colors all we +care about is whether the colors are + + align:start position:0% +care about is whether the colors are + + + align:start position:0% +care about is whether the colors are +equal or not so + + align:start position:0% +equal or not so + + + align:start position:0% +equal or not so +you don't normally think of those as + + align:start position:0% +you don't normally think of those as + + + align:start position:0% +you don't normally think of those as +numbers you can think of them as + + align:start position:0% +numbers you can think of them as + + + align:start position:0% +numbers you can think of them as +vertices in a graph or something I mean + + align:start position:0% +vertices in a graph or something I mean + + + align:start position:0% +vertices in a graph or something I mean +they're more like combinatorial objects + + align:start position:0% +they're more like combinatorial objects + + + align:start position:0% +they're more like combinatorial objects +you're not you never adding two colors + + align:start position:0% +you're not you never adding two colors + + + align:start position:0% +you're not you never adding two colors +together yes um the other point is that + + align:start position:0% +together yes um the other point is that + + + align:start position:0% +together yes um the other point is that +the number of different colors you can + + align:start position:0% +the number of different colors you can + + + align:start position:0% +the number of different colors you can +get is at most four times n because + + align:start position:0% +get is at most four times n because + + + align:start position:0% +get is at most four times n because +number of colors is at most four * n + + align:start position:0% +number of colors is at most four * n + + + align:start position:0% +number of colors is at most four * n +yeah you could write down a color as two + + align:start position:0% +yeah you could write down a color as two + + + align:start position:0% +yeah you could write down a color as two +to the two to the N but why supposed to + + align:start position:0% +to the two to the N but why supposed to + + + align:start position:0% +to the two to the N but why supposed to +be an efficient encoding so there really + + align:start position:0% +be an efficient encoding so there really + + + align:start position:0% +be an efficient encoding so there really +no numbers here so it doesn't even make + + align:start position:0% +no numbers here so it doesn't even make + + + align:start position:0% +no numbers here so it doesn't even make +sense to say this problem is strongly NP + + align:start position:0% +sense to say this problem is strongly NP + + + align:start position:0% +sense to say this problem is strongly NP +hard but even worse if I started with + + align:start position:0% +hard but even worse if I started with + + + align:start position:0% +hard but even worse if I started with +two partition and I did this reduction + + align:start position:0% +two partition and I did this reduction + + + align:start position:0% +two partition and I did this reduction +exactly as drawn but not as tall I could + + align:start position:0% +exactly as drawn but not as tall I could + + + align:start position:0% +exactly as drawn but not as tall I could +still make it a square but uh everything + + align:start position:0% +still make it a square but uh everything + + + align:start position:0% +still make it a square but uh everything +would break because for two partition to + + align:start position:0% +would break because for two partition to + + + align:start position:0% +would break because for two partition to +be hard those numbers the AIS have to be + + align:start position:0% +be hard those numbers the AIS have to be + + + align:start position:0% +be hard those numbers the AIS have to be +exponential in value if I have an + + align:start position:0% +exponential in value if I have an + + + align:start position:0% +exponential in value if I have an +exponential value AI when I convert it + + align:start position:0% +exponential value AI when I convert it + + + align:start position:0% +exponential value AI when I convert it +into a rectangle or actually I convert + + align:start position:0% +into a rectangle or actually I convert + + + align:start position:0% +into a rectangle or actually I convert +it into a bunch of tiles I will have + + align:start position:0% +it into a bunch of tiles I will have + + + align:start position:0% +it into a bunch of tiles I will have +exponentially many tiles this + + align:start position:0% +exponentially many tiles this + + + align:start position:0% +exponentially many tiles this +construction will be of exponential size + + align:start position:0% +construction will be of exponential size + + + align:start position:0% +construction will be of exponential size +so I will get exponentially many + + align:start position:0% +so I will get exponentially many + + + align:start position:0% +so I will get exponentially many +different colors on the boundary so + + align:start position:0% +different colors on the boundary so + + + align:start position:0% +different colors on the boundary so +that's very bad even if you're clever + + align:start position:0% +that's very bad even if you're clever + + + align:start position:0% +that's very bad even if you're clever +and you say oh well all these tiles are + + align:start position:0% +and you say oh well all these tiles are + + + align:start position:0% +and you say oh well all these tiles are +all the same so maybe I'll encode them + + align:start position:0% +all the same so maybe I'll encode them + + + align:start position:0% +all the same so maybe I'll encode them +efficiently and say there's + + align:start position:0% +efficiently and say there's + + + align:start position:0% +efficiently and say there's +exponentially many of this one tile the + + align:start position:0% +exponentially many of this one tile the + + + align:start position:0% +exponentially many of this one tile the +ones in the boundary are all different + + align:start position:0% +ones in the boundary are all different + + + align:start position:0% +ones in the boundary are all different +so it's not a valid reduction you should + + align:start position:0% +so it's not a valid reduction you should + + + align:start position:0% +so it's not a valid reduction you should +always take a problem supposed to run in + + align:start position:0% +always take a problem supposed to run in + + + align:start position:0% +always take a problem supposed to run in +polinomial time and produce a result of + + align:start position:0% +polinomial time and produce a result of + + + align:start position:0% +polinomial time and produce a result of +polinomial size so if I start with + + align:start position:0% +polinomial size so if I start with + + + align:start position:0% +polinomial size so if I start with +something where the input is polinomial + + align:start position:0% +something where the input is polinomial + + + align:start position:0% +something where the input is polinomial +size but it has exponentially large AI I + + align:start position:0% +size but it has exponentially large AI I + + + align:start position:0% +size but it has exponentially large AI I +do this I get an exponential size + + align:start position:0% +do this I get an exponential size + + + align:start position:0% +do this I get an exponential size +uh puzzle which is tough to boring to + + align:start position:0% +uh puzzle which is tough to boring to + + + align:start position:0% +uh puzzle which is tough to boring to +solve I don't know uh it's not a valid + + align:start position:0% +solve I don't know uh it's not a valid + + + align:start position:0% +solve I don't know uh it's not a valid +NP hardness reduction this is why we + + align:start position:0% +NP hardness reduction this is why we + + + align:start position:0% +NP hardness reduction this is why we +want to start from three partition + + align:start position:0% +want to start from three partition + + + align:start position:0% +want to start from three partition +because then I know even if what I'm + + align:start position:0% +because then I know even if what I'm + + + align:start position:0% +because then I know even if what I'm +doing here is representing the AI in uny + + align:start position:0% +doing here is representing the AI in uny + + + align:start position:0% +doing here is representing the AI in uny +I take AI I say okay I'm going to have + + align:start position:0% +I take AI I say okay I'm going to have + + + align:start position:0% +I take AI I say okay I'm going to have +that many square tiles that is exactly + + align:start position:0% +that many square tiles that is exactly + + + align:start position:0% +that many square tiles that is exactly +unary representation and we know a three + + align:start position:0% +unary representation and we know a three + + + align:start position:0% +unary representation and we know a three +partition that will have polinomial size + + align:start position:0% +partition that will have polinomial size + + + align:start position:0% +partition that will have polinomial size +and so we're good this is why we care + + align:start position:0% +and so we're good this is why we care + + + align:start position:0% +and so we're good this is why we care +about strong andp hardness so much + + align:start position:0% +about strong andp hardness so much + + + align:start position:0% +about strong andp hardness so much +because a lot of puzzles you can only + + align:start position:0% +because a lot of puzzles you can only + + + align:start position:0% +because a lot of puzzles you can only +represent numbers uny then you you're + + align:start position:0% +represent numbers uny then you you're + + + align:start position:0% +represent numbers uny then you you're +forced to work with + + align:start position:0% +forced to work with + + + align:start position:0% +forced to work with +repartition Okay uh next + + align:start position:0% +repartition Okay uh next + + + align:start position:0% +repartition Okay uh next +puzzle is uh signed Edge matching + + align:start position:0% +puzzle is uh signed Edge matching + + + align:start position:0% +puzzle is uh signed Edge matching +puzzles like the lizards suppose same + + align:start position:0% +puzzles like the lizards suppose same + + + align:start position:0% +puzzles like the lizards suppose same +setup but now the colors aren't supposed + + align:start position:0% +setup but now the colors aren't supposed + + + align:start position:0% +setup but now the colors aren't supposed +to be equal they're supposed to be + + align:start position:0% +to be equal they're supposed to be + + + align:start position:0% +to be equal they're supposed to be +opposites uh so I'm just going to modify + + align:start position:0% +opposites uh so I'm just going to modify + + + align:start position:0% +opposites uh so I'm just going to modify +this diagram and I will use capital + + align:start position:0% +this diagram and I will use capital + + + align:start position:0% +this diagram and I will use capital +letters to denote tals of lizards and + + align:start position:0% +letters to denote tals of lizards and + + + align:start position:0% +letters to denote tals of lizards and +lowercase letters to represent heads of + + align:start position:0% +lowercase letters to represent heads of + + + align:start position:0% +lowercase letters to represent heads of +lizards and little B only matches + + align:start position:0% +lizards and little B only matches + + + align:start position:0% +lizards and little B only matches +capital B does not match little B you + + align:start position:0% +capital B does not match little B you + + + align:start position:0% +capital B does not match little B you +can't put two heads together two tails + + align:start position:0% +can't put two heads together two tails + + + align:start position:0% +can't put two heads together two tails +together uh well you can + + align:start position:0% +together uh well you can + + + align:start position:0% +together uh well you can +reduce uh these things which I'll call + + align:start position:0% +reduce uh these things which I'll call + + + align:start position:0% +reduce uh these things which I'll call +unsigned Edge matching puzzles to uh + + align:start position:0% +unsigned Edge matching puzzles to uh + + + align:start position:0% +unsigned Edge matching puzzles to uh +these things which I'll call signed Edge + + align:start position:0% +these things which I'll call signed Edge + + + align:start position:0% +these things which I'll call signed Edge +matching + + align:start position:0% +matching + + + align:start position:0% +matching +puzzles with this easy Gadget if you + + align:start position:0% +puzzles with this easy Gadget if you + + + align:start position:0% +puzzles with this easy Gadget if you +have a tile with let's just say colors + + align:start position:0% +have a tile with let's just say colors + + + align:start position:0% +have a tile with let's just say colors +AB B CD some of them might be equal I'm + + align:start position:0% +AB B CD some of them might be equal I'm + + + align:start position:0% +AB B CD some of them might be equal I'm +going to replace that one tile with + + align:start position:0% +going to replace that one tile with + + + align:start position:0% +going to replace that one tile with +these four tiles + + align:start position:0% +these four tiles + + + align:start position:0% +these four tiles +and scale everything up by a factor of + + align:start position:0% +and scale everything up by a factor of + + + align:start position:0% +and scale everything up by a factor of +two scale the target shape by a factor + + align:start position:0% +two scale the target shape by a factor + + + align:start position:0% +two scale the target shape by a factor +of two uh these colors appear + + align:start position:0% +of two uh these colors appear + + + align:start position:0% +of two uh these colors appear +exactly once with each sign and so + + align:start position:0% +exactly once with each sign and so + + + align:start position:0% +exactly once with each sign and so +you're forced again because there's a + + align:start position:0% +you're forced again because there's a + + + align:start position:0% +you're forced again because there's a +frame and all the boundary is eaten up + + align:start position:0% +frame and all the boundary is eaten up + + + align:start position:0% +frame and all the boundary is eaten up +you're forced uh to match these guys to + + align:start position:0% +you're forced uh to match these guys to + + + align:start position:0% +you're forced uh to match these guys to +each other therefore you're forced to + + align:start position:0% +each other therefore you're forced to + + + align:start position:0% +each other therefore you're forced to +make this 2x two + + align:start position:0% +make this 2x two + + + align:start position:0% +make this 2x two +tile and so uh that 2x two tile is + + align:start position:0% +tile and so uh that 2x two tile is + + + align:start position:0% +tile and so uh that 2x two tile is +supposed to represent this one by one + + align:start position:0% +supposed to represent this one by one + + + align:start position:0% +supposed to represent this one by one +tile and the claim is um signs no longer + + align:start position:0% +tile and the claim is um signs no longer + + + align:start position:0% +tile and the claim is um signs no longer +matter because we put little a big a + + align:start position:0% +matter because we put little a big a + + + align:start position:0% +matter because we put little a big a +little B Big B little c big c and so on + + align:start position:0% +little B Big B little c big c and so on + + + align:start position:0% +little B Big B little c big c and so on +so if I took another tile like over + + align:start position:0% +so if I took another tile like over + + + align:start position:0% +so if I took another tile like over +here um and it has something like + + align:start position:0% +here um and it has something like + + + align:start position:0% +here um and it has something like +capital D lowercase D that's going to + + align:start position:0% +capital D lowercase D that's going to + + + align:start position:0% +capital D lowercase D that's going to +match with this lowercase b lowercase b + + align:start position:0% +match with this lowercase b lowercase b + + + align:start position:0% +match with this lowercase b lowercase b +if and only if B equals D so if the + + align:start position:0% +if and only if B equals D so if the + + + align:start position:0% +if and only if B equals D so if the +original colors are equal the resulting + + align:start position:0% +original colors are equal the resulting + + + align:start position:0% +original colors are equal the resulting +colors will be equal and opposite so + + align:start position:0% +colors will be equal and opposite so + + + align:start position:0% +colors will be equal and opposite so +they'll be the same letter of the + + align:start position:0% +they'll be the same letter of the + + + align:start position:0% +they'll be the same letter of the +alphabet but with opposite signs and so + + align:start position:0% +alphabet but with opposite signs and so + + + align:start position:0% +alphabet but with opposite signs and so +everything will match up CU this capital + + align:start position:0% +everything will match up CU this capital + + + align:start position:0% +everything will match up CU this capital +letter will match here this lowercase + + align:start position:0% +letter will match here this lowercase + + + align:start position:0% +letter will match here this lowercase +letter will match there is that clear so + + align:start position:0% +letter will match there is that clear so + + + align:start position:0% +letter will match there is that clear so +it's really the becomes the same puzzle + + align:start position:0% +it's really the becomes the same puzzle + + + align:start position:0% +it's really the becomes the same puzzle +and you know this one's going to be + + align:start position:0% +and you know this one's going to be + + + align:start position:0% +and you know this one's going to be +solvable if only if this one is so we + + align:start position:0% +solvable if only if this one is so we + + + align:start position:0% +solvable if only if this one is so we +get strong NP well just NP hardness of + + align:start position:0% +get strong NP well just NP hardness of + + + align:start position:0% +get strong NP well just NP hardness of +signed Edge matching puzzles cool uh + + align:start position:0% +signed Edge matching puzzles cool uh + + + align:start position:0% +signed Edge matching puzzles cool uh +next puzzle these are all in the same + + align:start position:0% +next puzzle these are all in the same + + + align:start position:0% +next puzzle these are all in the same +paper it was a fun paper uh even older + + align:start position:0% +paper it was a fun paper uh even older + + + align:start position:0% +paper it was a fun paper uh even older +jigsaw puzzles this is not the oldest + + align:start position:0% +jigsaw puzzles this is not the oldest + + + align:start position:0% +jigsaw puzzles this is not the oldest +jigsaw puzzle it's one of the newest + + align:start position:0% +jigsaw puzzle it's one of the newest + + + align:start position:0% +jigsaw puzzle it's one of the newest +it's our course poster turned into a + + align:start position:0% +it's our course poster turned into a + + + align:start position:0% +it's our course poster turned into a +jigsa puzzle if you want to make your + + align:start position:0% +jigsa puzzle if you want to make your + + + align:start position:0% +jigsa puzzle if you want to make your +own jiga puzzles go there they go back + + align:start position:0% +own jiga puzzles go there they go back + + + align:start position:0% +own jiga puzzles go there they go back +to the 1760s when they were made with + + align:start position:0% +to the 1760s when they were made with + + + align:start position:0% +to the 1760s when they were made with +jigsaws hence the name uh but basically + + align:start position:0% +jigsaws hence the name uh but basically + + + align:start position:0% +jigsaws hence the name uh but basically +we have square pieces and each side of + + align:start position:0% +we have square pieces and each side of + + + align:start position:0% +we have square pieces and each side of +this I'll assume that's a special kind + + align:start position:0% +this I'll assume that's a special kind + + + align:start position:0% +this I'll assume that's a special kind +of jigsaw puzzle most common uh each + + align:start position:0% +of jigsaw puzzle most common uh each + + + align:start position:0% +of jigsaw puzzle most common uh each +Edge can either be straight that means + + align:start position:0% +Edge can either be straight that means + + + align:start position:0% +Edge can either be straight that means +it's on the boundary uh it can be uh a + + align:start position:0% +it's on the boundary uh it can be uh a + + + align:start position:0% +it's on the boundary uh it can be uh a +pocket or a tab and each pocket and tab + + align:start position:0% +pocket or a tab and each pocket and tab + + + align:start position:0% +pocket or a tab and each pocket and tab +is slightly differently shaped although + + align:start position:0% +is slightly differently shaped although + + + align:start position:0% +is slightly differently shaped although +maybe not in this picture usually they + + align:start position:0% +maybe not in this picture usually they + + + align:start position:0% +maybe not in this picture usually they +are um I'm going to allow that some of + + align:start position:0% +are um I'm going to allow that some of + + + align:start position:0% +are um I'm going to allow that some of +the pockets and the tabs have the same + + align:start position:0% +the pockets and the tabs have the same + + + align:start position:0% +the pockets and the tabs have the same +shape that's what you might call + + align:start position:0% +shape that's what you might call + + + align:start position:0% +shape that's what you might call +ambiguous mates most jigsaw puzzles sold + + align:start position:0% +ambiguous mates most jigsaw puzzles sold + + + align:start position:0% +ambiguous mates most jigsaw puzzles sold +in the world do not have ambiguous mates + + align:start position:0% +in the world do not have ambiguous mates + + + align:start position:0% +in the world do not have ambiguous mates +but let's say they do and to make it NP + + align:start position:0% +but let's say they do and to make it NP + + + align:start position:0% +but let's say they do and to make it NP +hardcore uh there's no image on the + + align:start position:0% +hardcore uh there's no image on the + + + align:start position:0% +hardcore uh there's no image on the +Pieces Just a white puzzle now those are + + align:start position:0% +Pieces Just a white puzzle now those are + + + align:start position:0% +Pieces Just a white puzzle now those are +sold you can buy white all wh or all + + align:start position:0% +sold you can buy white all wh or all + + + align:start position:0% +sold you can buy white all wh or all +single color uh puzzles and uh but + + align:start position:0% +single color uh puzzles and uh but + + + align:start position:0% +single color uh puzzles and uh but +usually they don't have ambiguous mates + + align:start position:0% +usually they don't have ambiguous mates + + + align:start position:0% +usually they don't have ambiguous mates +that's like the ultimate combo uh if you + + align:start position:0% +that's like the ultimate combo uh if you + + + align:start position:0% +that's like the ultimate combo uh if you +don't assume either of those things then + + align:start position:0% +don't assume either of those things then + + + align:start position:0% +don't assume either of those things then +the problem problem is easy so we don't + + align:start position:0% +the problem problem is easy so we don't + + + align:start position:0% +the problem problem is easy so we don't +care about that there are papers about + + align:start position:0% +care about that there are papers about + + + align:start position:0% +care about that there are papers about +how to solve jigsaw puzzles in the + + align:start position:0% +how to solve jigsaw puzzles in the + + + align:start position:0% +how to solve jigsaw puzzles in the +Practical case but um in our situation + + align:start position:0% +Practical case but um in our situation + + + align:start position:0% +Practical case but um in our situation +we can just I mean that's basically is + + align:start position:0% +we can just I mean that's basically is + + + align:start position:0% +we can just I mean that's basically is +Edge matching puzzles with signs this is + + align:start position:0% +Edge matching puzzles with signs this is + + + align:start position:0% +Edge matching puzzles with signs this is +actually probably why I care about + + align:start position:0% +actually probably why I care about + + + align:start position:0% +actually probably why I care about +signed puzzles the most uh I have + + align:start position:0% +signed puzzles the most uh I have + + + align:start position:0% +signed puzzles the most uh I have +lowercase letters those are going to + + align:start position:0% +lowercase letters those are going to + + + align:start position:0% +lowercase letters those are going to +correspond to Pockets I have uppercase + + align:start position:0% +correspond to Pockets I have uppercase + + + align:start position:0% +correspond to Pockets I have uppercase +letters those are going to correspond to + + align:start position:0% +letters those are going to correspond to + + + align:start position:0% +letters those are going to correspond to +tabs and of course a tab must meet a + + align:start position:0% +tabs and of course a tab must meet a + + + align:start position:0% +tabs and of course a tab must meet a +pocket same as a lowercase letter must + + align:start position:0% +pocket same as a lowercase letter must + + + align:start position:0% +pocket same as a lowercase letter must +meet an uppercase letter and so that is + + align:start position:0% +meet an uppercase letter and so that is + + + align:start position:0% +meet an uppercase letter and so that is +the same thing uh I would like my target + + align:start position:0% +the same thing uh I would like my target + + + align:start position:0% +the same thing uh I would like my target +shape to be a square cuz that's clean uh + + align:start position:0% +shape to be a square cuz that's clean uh + + + align:start position:0% +shape to be a square cuz that's clean uh +so whenever I have a unique color which + + align:start position:0% +so whenever I have a unique color which + + + align:start position:0% +so whenever I have a unique color which +is one that I know has to be on the + + align:start position:0% +is one that I know has to be on the + + + align:start position:0% +is one that I know has to be on the +boundary I'm going to make it a flat + + align:start position:0% +boundary I'm going to make it a flat + + + align:start position:0% +boundary I'm going to make it a flat +thing and then I know in this series of + + align:start position:0% +thing and then I know in this series of + + + align:start position:0% +thing and then I know in this series of +reductions I should draw the series of + + align:start position:0% +reductions I should draw the series of + + + align:start position:0% +reductions I should draw the series of +reductions because it's kind of fun + + align:start position:0% + + + + align:start position:0% + +um so + + align:start position:0% +um so + + + align:start position:0% +um so +far kind of started with rectangle + + align:start position:0% +far kind of started with rectangle + + + align:start position:0% +far kind of started with rectangle +packing I guess technically we started + + align:start position:0% +packing I guess technically we started + + + align:start position:0% +packing I guess technically we started +with three partition + + align:start position:0% +with three partition + + + align:start position:0% +with three partition +uh I'll draw it like + + align:start position:0% + + + + align:start position:0% + +this we reduce that + + align:start position:0% +this we reduce that + + + align:start position:0% +this we reduce that +to uh Edge + + align:start position:0% + + + + align:start position:0% + +matching + + align:start position:0% +matching + + + align:start position:0% +matching +puzzles then we reduce that + + align:start position:0% +puzzles then we reduce that + + + align:start position:0% +puzzles then we reduce that +to uh signed Edge matching + + align:start position:0% + + + + align:start position:0% + +puzzles then we reduce that to jigsaw + + align:start position:0% +puzzles then we reduce that to jigsaw + + + align:start position:0% +puzzles then we reduce that to jigsaw +puzzles + + align:start position:0% +puzzles + + + align:start position:0% +puzzles +and if you follow this series of + + align:start position:0% +and if you follow this series of + + + align:start position:0% +and if you follow this series of +reductions and see what you get we know + + align:start position:0% +reductions and see what you get we know + + + align:start position:0% +reductions and see what you get we know +that the boundary shape will be a square + + align:start position:0% +that the boundary shape will be a square + + + align:start position:0% +that the boundary shape will be a square +because that frame Gadget uh is a square + + align:start position:0% +because that frame Gadget uh is a square + + + align:start position:0% +because that frame Gadget uh is a square +and if we make all the unique things + + align:start position:0% +and if we make all the unique things + + + align:start position:0% +and if we make all the unique things +flat then the shape will actually be + + align:start position:0% +flat then the shape will actually be + + + align:start position:0% +flat then the shape will actually be +square there the reason I'm drawing it + + align:start position:0% +square there the reason I'm drawing it + + + align:start position:0% +square there the reason I'm drawing it +this way because we have another + + align:start position:0% +this way because we have another + + + align:start position:0% +this way because we have another +one um so next puzzle so you might ask + + align:start position:0% +one um so next puzzle so you might ask + + + align:start position:0% +one um so next puzzle so you might ask +well eternity 2 was an edge matching + + align:start position:0% +well eternity 2 was an edge matching + + + align:start position:0% +well eternity 2 was an edge matching +puzzle what was eternity one uh well + + align:start position:0% +puzzle what was eternity one uh well + + + align:start position:0% +puzzle what was eternity one uh well +it's something called a polyform packing + + align:start position:0% +it's something called a polyform packing + + + align:start position:0% +it's something called a polyform packing +puzzle uh these are um if you take an + + align:start position:0% +puzzle uh these are um if you take an + + + align:start position:0% +puzzle uh these are um if you take an +equilateral triangle and cut it in half + + align:start position:0% +equilateral triangle and cut it in half + + + align:start position:0% +equilateral triangle and cut it in half +like that um that's a shape and if you + + align:start position:0% +like that um that's a shape and if you + + + align:start position:0% +like that um that's a shape and if you +take uh K copies of that shape join them + + align:start position:0% +take uh K copies of that shape join them + + + align:start position:0% +take uh K copies of that shape join them +edge to edge along matching Edge lengths + + align:start position:0% +edge to edge along matching Edge lengths + + + align:start position:0% +edge to edge along matching Edge lengths +uh you get you can get all these shapes + + align:start position:0% +uh you get you can get all these shapes + + + align:start position:0% +uh you get you can get all these shapes +it's like Tetris but instead of with + + align:start position:0% +it's like Tetris but instead of with + + + align:start position:0% +it's like Tetris but instead of with +squares you start with that shape and + + align:start position:0% +squares you start with that shape and + + + align:start position:0% +squares you start with that shape and +you join a bunch more of them together I + + align:start position:0% +you join a bunch more of them together I + + + align:start position:0% +you join a bunch more of them together I +don't know exactly how many they may not + + align:start position:0% +don't know exactly how many they may not + + + align:start position:0% +don't know exactly how many they may not +even be all the same area and your goal + + align:start position:0% +even be all the same area and your goal + + + align:start position:0% +even be all the same area and your goal +is to fit inside this big uh decagon or + + align:start position:0% +is to fit inside this big uh decagon or + + + align:start position:0% +is to fit inside this big uh decagon or +something + + align:start position:0% +something + + + align:start position:0% +something +uh this was solved million pounds were + + align:start position:0% +uh this was solved million pounds were + + + align:start position:0% +uh this was solved million pounds were +acquired uh by two people uh I think + + align:start position:0% +acquired uh by two people uh I think + + + align:start position:0% +acquired uh by two people uh I think +they were uh mathematicians Alex and + + align:start position:0% +they were uh mathematicians Alex and + + + align:start position:0% +they were uh mathematicians Alex and +Oliver in 2000 so actually quite soon + + align:start position:0% +Oliver in 2000 so actually quite soon + + + align:start position:0% +Oliver in 2000 so actually quite soon +after the puzzle was posed I think + + align:start position:0% +after the puzzle was posed I think + + + align:start position:0% +after the puzzle was posed I think +within a year less than a year uh so + + align:start position:0% +within a year less than a year uh so + + + align:start position:0% +within a year less than a year uh so +there was you know articles about uh how + + align:start position:0% +there was you know articles about uh how + + + align:start position:0% +there was you know articles about uh how +the insurance company was not happy but + + align:start position:0% +the insurance company was not happy but + + + align:start position:0% +the insurance company was not happy but +that's why you get insured against a + + align:start position:0% +that's why you get insured against a + + + align:start position:0% +that's why you get insured against a +puzzle being solved I guess but in + + align:start position:0% +puzzle being solved I guess but in + + + align:start position:0% +puzzle being solved I guess but in +eternity 2 a consequence is much harder + + align:start position:0% +eternity 2 a consequence is much harder + + + align:start position:0% +eternity 2 a consequence is much harder +and uh so no one has solved it yet but + + align:start position:0% +and uh so no one has solved it yet but + + + align:start position:0% +and uh so no one has solved it yet but +it will happen someday I'm sure uh so + + align:start position:0% +it will happen someday I'm sure uh so + + + align:start position:0% +it will happen someday I'm sure uh so +this gives you a clear sense of what the + + align:start position:0% +this gives you a clear sense of what the + + + align:start position:0% +this gives you a clear sense of what the +shapes look like uh so I want to prove + + align:start position:0% +shapes look like uh so I want to prove + + + align:start position:0% +shapes look like uh so I want to prove +these puzzles are NP hard + + align:start position:0% +these puzzles are NP hard + + + align:start position:0% +these puzzles are NP hard +also by reduction from jigsaw + + align:start position:0% +also by reduction from jigsaw + + + align:start position:0% +also by reduction from jigsaw +puzzles uh so let's just bring up the + + align:start position:0% +puzzles uh so let's just bring up the + + + align:start position:0% +puzzles uh so let's just bring up the +picture so we just we just did this + + align:start position:0% +picture so we just we just did this + + + align:start position:0% +picture so we just we just did this +reduction it actually works in both ways + + align:start position:0% +reduction it actually works in both ways + + + align:start position:0% +reduction it actually works in both ways +they're really the same puzzle this does + + align:start position:0% +they're really the same puzzle this does + + + align:start position:0% +they're really the same puzzle this does +not work so easily in both ways uh but + + align:start position:0% +not work so easily in both ways uh but + + + align:start position:0% +not work so easily in both ways uh but +I'm gonna take a jigsaw piece I'm going + + align:start position:0% +I'm gonna take a jigsaw piece I'm going + + + align:start position:0% +I'm gonna take a jigsaw piece I'm going +to turn it into roughly a square made up + + align:start position:0% +to turn it into roughly a square made up + + + align:start position:0% +to turn it into roughly a square made up +of little squares I'm not going to work + + align:start position:0% +of little squares I'm not going to work + + + align:start position:0% +of little squares I'm not going to work +on the the half triangles although I + + align:start position:0% +on the the half triangles although I + + + align:start position:0% +on the the half triangles although I +think it wouldn't be any harder it's a + + align:start position:0% +think it wouldn't be any harder it's a + + + align:start position:0% +think it wouldn't be any harder it's a +lot easier to think about Square puzzles + + align:start position:0% +lot easier to think about Square puzzles + + + align:start position:0% +lot easier to think about Square puzzles +more like Tetris these are polyomino so + + align:start position:0% +more like Tetris these are polyomino so + + + align:start position:0% +more like Tetris these are polyomino so +polyomino packing is this type of puzzle + + align:start position:0% +polyomino packing is this type of puzzle + + + align:start position:0% +polyomino packing is this type of puzzle +they also exist but that no one has won + + align:start position:0% +they also exist but that no one has won + + + align:start position:0% +they also exist but that no one has won +two million a million pounds from them + + align:start position:0% +two million a million pounds from them + + + align:start position:0% +two million a million pounds from them +so that's why I showed eternity um so + + align:start position:0% +so that's why I showed eternity um so + + + align:start position:0% +so that's why I showed eternity um so +almost a square but then in the middle + + align:start position:0% +almost a square but then in the middle + + + align:start position:0% +almost a square but then in the middle +of the edge we're going to write in + + align:start position:0% +of the edge we're going to write in + + + align:start position:0% +of the edge we're going to write in +binary uh what the shape was here I mean + + align:start position:0% +binary uh what the shape was here I mean + + + align:start position:0% +binary uh what the shape was here I mean +so there was you know a color over here + + align:start position:0% +so there was you know a color over here + + + align:start position:0% +so there was you know a color over here +and we can and a shape here uh all we + + align:start position:0% +and we can and a shape here uh all we + + + align:start position:0% +and we can and a shape here uh all we +care about is whether there're the same + + align:start position:0% +care about is whether there're the same + + + align:start position:0% +care about is whether there're the same +or different so there's only you know 4N + + align:start position:0% +or different so there's only you know 4N + + + align:start position:0% +or different so there's only you know 4N +different uh colors out there and so + + align:start position:0% +different uh colors out there and so + + + align:start position:0% +different uh colors out there and so +we're going to take log of 4N bits and + + align:start position:0% +we're going to take log of 4N bits and + + + align:start position:0% +we're going to take log of 4N bits and +write them in this way and if it was + + align:start position:0% +write them in this way and if it was + + + align:start position:0% +write them in this way and if it was +indented uh whenever we have a one we're + + align:start position:0% +indented uh whenever we have a one we're + + + align:start position:0% +indented uh whenever we have a one we're +going to indent here and if it's a a tab + + align:start position:0% +going to indent here and if it's a a tab + + + align:start position:0% +going to indent here and if it's a a tab +instead of a pocket wherever we have a + + align:start position:0% +instead of a pocket wherever we have a + + + align:start position:0% +instead of a pocket wherever we have a +one we're going to + + align:start position:0% +one we're going to + + + align:start position:0% +one we're going to +outdent okay so um these are all + + align:start position:0% +outdent okay so um these are all + + + align:start position:0% +outdent okay so um these are all +different codes and so none of them uh + + align:start position:0% +different codes and so none of them uh + + + align:start position:0% +different codes and so none of them uh +fit together for example uh + + align:start position:0% +fit together for example uh + + + align:start position:0% +fit together for example uh +and let's see anything match + + align:start position:0% + + + + align:start position:0% + +up this one matches with this one yeah + + align:start position:0% +up this one matches with this one yeah + + + align:start position:0% +up this one matches with this one yeah +because if I rotate it around stick it + + align:start position:0% +because if I rotate it around stick it + + + align:start position:0% +because if I rotate it around stick it +on it will match up so you have to make + + align:start position:0% +on it will match up so you have to make + + + align:start position:0% +on it will match up so you have to make +sure you get the orientations of the + + align:start position:0% +sure you get the orientations of the + + + align:start position:0% +sure you get the orientations of the +codes all right uh but you can do this + + align:start position:0% +codes all right uh but you can do this + + + align:start position:0% +codes all right uh but you can do this +and two things will fit together and + + align:start position:0% +and two things will fit together and + + + align:start position:0% +and two things will fit together and +make a nice clean seam if and only if + + align:start position:0% +make a nice clean seam if and only if + + + align:start position:0% +make a nice clean seam if and only if +the original colors matched and so this + + align:start position:0% +the original colors matched and so this + + + align:start position:0% +the original colors matched and so this +represents that puzzle where we've + + align:start position:0% +represents that puzzle where we've + + + align:start position:0% +represents that puzzle where we've +increased the we've blown everything up + + align:start position:0% +increased the we've blown everything up + + + align:start position:0% +increased the we've blown everything up +by like a logarithmic factor in each + + align:start position:0% +by like a logarithmic factor in each + + + align:start position:0% +by like a logarithmic factor in each +Dimension uh but the number of pieces is + + align:start position:0% +Dimension uh but the number of pieces is + + + align:start position:0% +Dimension uh but the number of pieces is +staying the same in a + + align:start position:0% +staying the same in a + + + align:start position:0% +staying the same in a +sense uh and then so that was this + + align:start position:0% +sense uh and then so that was this + + + align:start position:0% +sense uh and then so that was this +reduction to polyomino + + align:start position:0% + + + + align:start position:0% + +packing for fun we close the loop and + + align:start position:0% +packing for fun we close the loop and + + + align:start position:0% +packing for fun we close the loop and +reduce from polyomino packing to Edge + + align:start position:0% +reduce from polyomino packing to Edge + + + align:start position:0% +reduce from polyomino packing to Edge +matching uh in this way so we're going + + align:start position:0% +matching uh in this way so we're going + + + align:start position:0% +matching uh in this way so we're going +to take our polyomino carve it up into + + align:start position:0% +to take our polyomino carve it up into + + + align:start position:0% +to take our polyomino carve it up into +little squares turn them into Edge + + align:start position:0% +little squares turn them into Edge + + + align:start position:0% +little squares turn them into Edge +matching puzzle and here I actually want + + align:start position:0% +matching puzzle and here I actually want + + + align:start position:0% +matching puzzle and here I actually want +to allow rotation so I'm going to change + + align:start position:0% +to allow rotation so I'm going to change + + + align:start position:0% +to allow rotation so I'm going to change +these colors to all percent signs and + + align:start position:0% +these colors to all percent signs and + + + align:start position:0% +these colors to all percent signs and +now + + align:start position:0% +now + + + align:start position:0% +now +uh just the same puzzle yeah so we have + + align:start position:0% +uh just the same puzzle yeah so we have + + + align:start position:0% +uh just the same puzzle yeah so we have +to use the frame again and so if you + + align:start position:0% +to use the frame again and so if you + + + align:start position:0% +to use the frame again and so if you +want you can just keep following these + + align:start position:0% +want you can just keep following these + + + align:start position:0% +want you can just keep following these +reductions over and over and over uh I + + align:start position:0% +reductions over and over and over uh I + + + align:start position:0% +reductions over and over and over uh I +think every time you do it you increase + + align:start position:0% +think every time you do it you increase + + + align:start position:0% +think every time you do it you increase +the scale factor by like a log Factor uh + + align:start position:0% +the scale factor by like a log Factor uh + + + align:start position:0% +the scale factor by like a log Factor uh +but it's kind of fun I mean it really + + align:start position:0% +but it's kind of fun I mean it really + + + align:start position:0% +but it's kind of fun I mean it really +shows these puzzles are very close to + + align:start position:0% +shows these puzzles are very close to + + + align:start position:0% +shows these puzzles are very close to +identical uh in that we didn't have to + + align:start position:0% +identical uh in that we didn't have to + + + align:start position:0% +identical uh in that we didn't have to +blow up the puzzle size by very much to + + align:start position:0% +blow up the puzzle size by very much to + + + align:start position:0% +blow up the puzzle size by very much to +go from one puzzle to the next so + + align:start position:0% +go from one puzzle to the next so + + + align:start position:0% +go from one puzzle to the next so +usually we're just thinking about + + align:start position:0% +usually we're just thinking about + + + align:start position:0% +usually we're just thinking about +polinomial blowup here we have a very + + align:start position:0% +polinomial blowup here we have a very + + + align:start position:0% +polinomial blowup here we have a very +small notion of blowup which is some + + align:start position:0% +small notion of blowup which is some + + + align:start position:0% +small notion of blowup which is some +tight sense in which these puzzles are + + align:start position:0% +tight sense in which these puzzles are + + + align:start position:0% +tight sense in which these puzzles are +almost the + + align:start position:0% +almost the + + + align:start position:0% +almost the +same okay end of + + align:start position:0% +same okay end of + + + align:start position:0% +same okay end of +paper uh Fun open + + align:start position:0% +paper uh Fun open + + + align:start position:0% +paper uh Fun open +problem is uh this reduction Used Log n + + align:start position:0% +problem is uh this reduction Used Log n + + + align:start position:0% +problem is uh this reduction Used Log n +by log and Order log n by log n Pieces + + align:start position:0% +by log and Order log n by log n Pieces + + + align:start position:0% +by log and Order log n by log n Pieces +what if your pieces only have area log + + align:start position:0% +what if your pieces only have area log + + + align:start position:0% +what if your pieces only have area log +n so maybe they're root log n by root + + align:start position:0% +n so maybe they're root log n by root + + + align:start position:0% +n so maybe they're root log n by root +log n or something like that I'm sure it + + align:start position:0% +log n or something like that I'm sure it + + + align:start position:0% +log n or something like that I'm sure it +should still be NP hard but you never + + align:start position:0% +should still be NP hard but you never + + + align:start position:0% +should still be NP hard but you never +know uh if for example their constant + + align:start position:0% + + + + align:start position:0% + +size actually well let's say if they're + + align:start position:0% +size actually well let's say if they're + + + align:start position:0% +size actually well let's say if they're +size two it's easy leave it at that even + + align:start position:0% +size two it's easy leave it at that even + + + align:start position:0% +size two it's easy leave it at that even +if the shape is very messy uh but if + + align:start position:0% +if the shape is very messy uh but if + + + align:start position:0% +if the shape is very messy uh but if +they're also 2 by two blocks it's easy + + align:start position:0% +they're also 2 by two blocks it's easy + + + align:start position:0% +they're also 2 by two blocks it's easy +so they're clearly small shapes are too + + align:start position:0% +so they're clearly small shapes are too + + + align:start position:0% +so they're clearly small shapes are too +easy but probably logarithmic area is + + align:start position:0% +easy but probably logarithmic area is + + + align:start position:0% +easy but probably logarithmic area is +where it starts to get interesting I + + align:start position:0% +where it starts to get interesting I + + + align:start position:0% +where it starts to get interesting I +don't know what about log log area + + align:start position:0% +don't know what about log log area + + + align:start position:0% +don't know what about log log area +that's probably neither inp hard or + + align:start position:0% +that's probably neither inp hard or + + + align:start position:0% +that's probably neither inp hard or +polinomial but oh well um + + align:start position:0% + + + + align:start position:0% + +cool so um I want to talk about one more + + align:start position:0% +cool so um I want to talk about one more + + + align:start position:0% +cool so um I want to talk about one more +problem one more hardness + + align:start position:0% + + + + align:start position:0% + +proof in this similar vein it's about + + align:start position:0% +proof in this similar vein it's about + + + align:start position:0% +proof in this similar vein it's about +packing I already raed just packing + + align:start position:0% +packing I already raed just packing + + + align:start position:0% +packing I already raed just packing +rectangles into rectangles or rectangles + + align:start position:0% +rectangles into rectangles or rectangles + + + align:start position:0% +rectangles into rectangles or rectangles +into a square what about squares into a + + align:start position:0% +into a square what about squares into a + + + align:start position:0% +into a square what about squares into a +square if you can tell that's a square + + align:start position:0% +square if you can tell that's a square + + + align:start position:0% +square if you can tell that's a square +not a rectangle okay this is a nice + + align:start position:0% +not a rectangle okay this is a nice + + + align:start position:0% +not a rectangle okay this is a nice +paper uh we've used it for other + + align:start position:0% +paper uh we've used it for other + + + align:start position:0% +paper uh we've used it for other +hardness proofs uh which we probably + + align:start position:0% +hardness proofs uh which we probably + + + align:start position:0% +hardness proofs uh which we probably +talk about next class so I'm given a + + align:start position:0% +talk about next class so I'm given a + + + align:start position:0% +talk about next class so I'm given a +bunch of squares and I'm given a Target + + align:start position:0% +bunch of squares and I'm given a Target + + + align:start position:0% +bunch of squares and I'm given a Target +Square do these squares fit in there and + + align:start position:0% +Square do these squares fit in there and + + + align:start position:0% +Square do these squares fit in there and +again we we'll probably use exact um + + align:start position:0% +again we we'll probably use exact um + + + align:start position:0% +again we we'll probably use exact um +initially we won't be exact packing uh + + align:start position:0% +initially we won't be exact packing uh + + + align:start position:0% +initially we won't be exact packing uh +but let's say that the squares can't can + + align:start position:0% +but let's say that the squares can't can + + + align:start position:0% +but let's say that the squares can't can +only rotate by multiple of 90 in other + + align:start position:0% +only rotate by multiple of 90 in other + + + align:start position:0% +only rotate by multiple of 90 in other +words they can't + + align:start position:0% +words they can't + + + align:start position:0% +words they can't +rotate uh we will fix that by making + + align:start position:0% +rotate uh we will fix that by making + + + align:start position:0% +rotate uh we will fix that by making +exact packing but uh why don't I jump to + + align:start position:0% +exact packing but uh why don't I jump to + + + align:start position:0% +exact packing but uh why don't I jump to +the + + align:start position:0% +the + + + align:start position:0% +the +reduction uh the heart of the reduction + + align:start position:0% +reduction uh the heart of the reduction + + + align:start position:0% +reduction uh the heart of the reduction +is this idea um we're just going to add + + align:start position:0% +is this idea um we're just going to add + + + align:start position:0% +is this idea um we're just going to add +a big number here I am going to use + + align:start position:0% +a big number here I am going to use + + + align:start position:0% +a big number here I am going to use +capital B for the big number this is + + align:start position:0% +capital B for the big number this is + + + align:start position:0% +capital B for the big number this is +what's in the paper this is a paper from + + align:start position:0% +what's in the paper this is a paper from + + + align:start position:0% +what's in the paper this is a paper from +1990 uh motivation here is you have a + + align:start position:0% +1990 uh motivation here is you have a + + + align:start position:0% +1990 uh motivation here is you have a +big grid supercomputer which were + + align:start position:0% +big grid supercomputer which were + + + align:start position:0% +big grid supercomputer which were +popular in the ' 80s and 90s um and you + + align:start position:0% +popular in the ' 80s and 90s um and you + + + align:start position:0% +popular in the ' 80s and 90s um and you +have a job which is a square grid of + + align:start position:0% +have a job which is a square grid of + + + align:start position:0% +have a job which is a square grid of +processors let's say and you want to + + align:start position:0% +processors let's say and you want to + + + align:start position:0% +processors let's say and you want to +execute them all in parallel but they're + + align:start position:0% +execute them all in parallel but they're + + + align:start position:0% +execute them all in parallel but they're +not allowed to overlap because that + + align:start position:0% +not allowed to overlap because that + + + align:start position:0% +not allowed to overlap because that +would slow your superc Computing down + + align:start position:0% +would slow your superc Computing down + + + align:start position:0% +would slow your superc Computing down +but you are allowed gaps let's + + align:start position:0% +but you are allowed gaps let's + + + align:start position:0% +but you are allowed gaps let's +say so uh I'm just going to take each of + + align:start position:0% +say so uh I'm just going to take each of + + + align:start position:0% +say so uh I'm just going to take each of +my AI numbers add this huge number to it + + align:start position:0% +my AI numbers add this huge number to it + + + align:start position:0% +my AI numbers add this huge number to it +so they're all roughly the same size + + align:start position:0% +so they're all roughly the same size + + + align:start position:0% +so they're all roughly the same size +this is the trick we did at the + + align:start position:0% +this is the trick we did at the + + + align:start position:0% +this is the trick we did at the +beginning of class with three partition + + align:start position:0% +beginning of class with three partition + + + align:start position:0% +beginning of class with three partition +right all these numbers all these sides + + align:start position:0% +right all these numbers all these sides + + + align:start position:0% +right all these numbers all these sides +are almost the same drawn them quite + + align:start position:0% +are almost the same drawn them quite + + + align:start position:0% +are almost the same drawn them quite +different but imagine they're just like + + align:start position:0% +different but imagine they're just like + + + align:start position:0% +different but imagine they're just like +tiny + + align:start position:0% +tiny + + + align:start position:0% +tiny +fluctuations and then uh I make the + + align:start position:0% +fluctuations and then uh I make the + + + align:start position:0% +fluctuations and then uh I make the +height of this rectangle for whatever + + align:start position:0% +height of this rectangle for whatever + + + align:start position:0% +height of this rectangle for whatever +reason I transpose my image uh that's + + align:start position:0% +reason I transpose my image uh that's + + + align:start position:0% +reason I transpose my image uh that's +probably why I was confused earlier um I + + align:start position:0% +probably why I was confused earlier um I + + + align:start position:0% +probably why I was confused earlier um I +just uh make the height three times the + + align:start position:0% +just uh make the height three times the + + + align:start position:0% +just uh make the height three times the +big number because I want three pieces + + align:start position:0% +big number because I want three pieces + + + align:start position:0% +big number because I want three pieces +to come together plus T my target sum of + + align:start position:0% +to come together plus T my target sum of + + + align:start position:0% +to come together plus T my target sum of +the AIS so this is a huge thing plus a + + align:start position:0% +the AIS so this is a huge thing plus a + + + align:start position:0% +the AIS so this is a huge thing plus a +super tiny thing uh but what it's saying + + align:start position:0% +super tiny thing uh but what it's saying + + + align:start position:0% +super tiny thing uh but what it's saying +is what you have slop they're all almost + + align:start position:0% +is what you have slop they're all almost + + + align:start position:0% +is what you have slop they're all almost +the same size there's that little bit of + + align:start position:0% +the same size there's that little bit of + + + align:start position:0% +the same size there's that little bit of +extra and that little bit extra has to + + align:start position:0% +extra and that little bit extra has to + + + align:start position:0% +extra and that little bit extra has to +add up to exactly T so this is one + + align:start position:0% +add up to exactly T so this is one + + + align:start position:0% +add up to exactly T so this is one +triple with the desired Target sum and + + align:start position:0% +triple with the desired Target sum and + + + align:start position:0% +triple with the desired Target sum and +then I want to get n over3 of them now + + align:start position:0% +then I want to get n over3 of them now + + + align:start position:0% +then I want to get n over3 of them now +here's where things get a little dicey + + align:start position:0% +here's where things get a little dicey + + + align:start position:0% +here's where things get a little dicey +you say okay let's just say I I take the + + align:start position:0% +you say okay let's just say I I take the + + + align:start position:0% +you say okay let's just say I I take the +largest one or actually I'll go all the + + align:start position:0% +largest one or actually I'll go all the + + + align:start position:0% +largest one or actually I'll go all the +way up to B plus T I know that every + + align:start position:0% +way up to B plus T I know that every + + + align:start position:0% +way up to B plus T I know that every +number I have is smaller than t uh + + align:start position:0% +number I have is smaller than t uh + + + align:start position:0% +number I have is smaller than t uh +because there sum of three of them is T + + align:start position:0% +because there sum of three of them is T + + + align:start position:0% +because there sum of three of them is T +so um I'm always going to have a gap + + align:start position:0% +so um I'm always going to have a gap + + + align:start position:0% +so um I'm always going to have a gap +here and let's say I just pack the next + + align:start position:0% +here and let's say I just pack the next + + + align:start position:0% +here and let's say I just pack the next +three there and then the next three + + align:start position:0% +three there and then the next three + + + align:start position:0% +three there and then the next three +there and so I'll leave enough room that + + align:start position:0% +there and so I'll leave enough room that + + + align:start position:0% +there and so I'll leave enough room that +even with this slop I can fit everything + + align:start position:0% +even with this slop I can fit everything + + + align:start position:0% +even with this slop I can fit everything +in so each one is B plus T and the + + align:start position:0% +in so each one is B plus T and the + + + align:start position:0% +in so each one is B plus T and the +number of them is n over3 so that will + + align:start position:0% +number of them is n over3 so that will + + + align:start position:0% +number of them is n over3 so that will +be the width of my rectangle looks like + + align:start position:0% +be the width of my rectangle looks like + + + align:start position:0% +be the width of my rectangle looks like +a lot of slop but that's because I drew + + align:start position:0% +a lot of slop but that's because I drew + + + align:start position:0% +a lot of slop but that's because I drew +this with the squares very different in + + align:start position:0% +this with the squares very different in + + + align:start position:0% +this with the squares very different in +size if we compute the amount of + + align:start position:0% +size if we compute the amount of + + + align:start position:0% +size if we compute the amount of +slop uh let's see the maximum like if + + align:start position:0% +slop uh let's see the maximum like if + + + align:start position:0% +slop uh let's see the maximum like if +you look at this distance um it's at + + align:start position:0% +you look at this distance um it's at + + + align:start position:0% +you look at this distance um it's at +most T certainly even if if AI were zero + + align:start position:0% +most T certainly even if if AI were zero + + + align:start position:0% +most T certainly even if if AI were zero +which is not allowed then this distance + + align:start position:0% +which is not allowed then this distance + + + align:start position:0% +which is not allowed then this distance +would be T so it's going to be even + + align:start position:0% +would be T so it's going to be even + + + align:start position:0% +would be T so it's going to be even +smaller than that but uh the gaps here + + align:start position:0% +smaller than that but uh the gaps here + + + align:start position:0% +smaller than that but uh the gaps here +are always at most T so we can take + + align:start position:0% +are always at most T so we can take + + + align:start position:0% +are always at most T so we can take +uh so this is a total + + align:start position:0% + + + + align:start position:0% + +slop is + + align:start position:0% +slop is + + + align:start position:0% +slop is +T + + align:start position:0% +T + + + align:start position:0% +T +times uh the height so that was like the + + align:start position:0% +times uh the height so that was like the + + + align:start position:0% +times uh the height so that was like the +width of a of one sliver of slop and + + align:start position:0% +width of a of one sliver of slop and + + + align:start position:0% +width of a of one sliver of slop and +then the height is 3B plus + + align:start position:0% + + + + align:start position:0% + +t + + align:start position:0% +t + + + align:start position:0% +t +and then times n over3 because there's n + + align:start position:0% +and then times n over3 because there's n + + + align:start position:0% +and then times n over3 because there's n +over3 of those things and hopefully this + + align:start position:0% +over3 of those things and hopefully this + + + align:start position:0% +over3 of those things and hopefully this +works uh I want to say this is less than + + align:start position:0% +works uh I want to say this is less than + + + align:start position:0% +works uh I want to say this is less than +b^2 + + align:start position:0% + + + + align:start position:0% + +if B is bigger than cool T * n thre's + + align:start position:0% +if B is bigger than cool T * n thre's + + + align:start position:0% +if B is bigger than cool T * n thre's +cancel so if B is I think this term + + align:start position:0% +cancel so if B is I think this term + + + align:start position:0% +cancel so if B is I think this term +won't matter because B is going to be + + align:start position:0% +won't matter because B is going to be + + + align:start position:0% +won't matter because B is going to be +bigger than T um so well yeah I maybe + + align:start position:0% +bigger than T um so well yeah I maybe + + + align:start position:0% +bigger than T um so well yeah I maybe +put a two there for extra safety then + + align:start position:0% +put a two there for extra safety then + + + align:start position:0% +put a two there for extra safety then +you're totally dwarfed uh so we're just + + align:start position:0% +you're totally dwarfed uh so we're just + + + align:start position:0% +you're totally dwarfed uh so we're just +dividing both sides by B we're getting 3 + + align:start position:0% +dividing both sides by B we're getting 3 + + + align:start position:0% +dividing both sides by B we're getting 3 +* T * n over 3 that's T * n okay um cool + + align:start position:0% +* T * n over 3 that's T * n okay um cool + + + align:start position:0% +* T * n over 3 that's T * n okay um cool +so the point is the total area of slop + + align:start position:0% +so the point is the total area of slop + + + align:start position:0% +so the point is the total area of slop +that I have here is less than a single + + align:start position:0% +that I have here is less than a single + + + align:start position:0% +that I have here is less than a single +Square single square is even bigger than + + align:start position:0% +Square single square is even bigger than + + + align:start position:0% +Square single square is even bigger than +this uh so you're not going to be able + + align:start position:0% +this uh so you're not going to be able + + + align:start position:0% +this uh so you're not going to be able +to pack any more squares and uh that's a + + align:start position:0% +to pack any more squares and uh that's a + + + align:start position:0% +to pack any more squares and uh that's a +vague argument but enough hand waving + + align:start position:0% +vague argument but enough hand waving + + + align:start position:0% +vague argument but enough hand waving +later and you prove that in fact any + + align:start position:0% +later and you prove that in fact any + + + align:start position:0% +later and you prove that in fact any +packing of these squares will give you + + align:start position:0% +packing of these squares will give you + + + align:start position:0% +packing of these squares will give you +three partition that requires more work + + align:start position:0% +three partition that requires more work + + + align:start position:0% +three partition that requires more work +um but uh this is some intuition why it + + align:start position:0% +um but uh this is some intuition why it + + + align:start position:0% +um but uh this is some intuition why it +is + + align:start position:0% +is + + + align:start position:0% +is +true um okay so this was actually + + align:start position:0% +true um okay so this was actually + + + align:start position:0% +true um okay so this was actually +packing squares into a rectangle but + + align:start position:0% +packing squares into a rectangle but + + + align:start position:0% +packing squares into a rectangle but +that wasn't the problem I started with I + + align:start position:0% +that wasn't the problem I started with I + + + align:start position:0% +that wasn't the problem I started with I +wanted to pack squares into a square uh + + align:start position:0% +wanted to pack squares into a square uh + + + align:start position:0% +wanted to pack squares into a square uh +so for that you need an infrastructure + + align:start position:0% +so for that you need an infrastructure + + + align:start position:0% +so for that you need an infrastructure +Gadget like the frame that we made + + align:start position:0% +Gadget like the frame that we made + + + align:start position:0% +Gadget like the frame that we made +before uh and this is kind of a cute + + align:start position:0% +before uh and this is kind of a cute + + + align:start position:0% +before uh and this is kind of a cute +number theory is Trick um I'm going to + + align:start position:0% +number theory is Trick um I'm going to + + + align:start position:0% +number theory is Trick um I'm going to +take some integer X we'll choose it + + align:start position:0% +take some integer X we'll choose it + + + align:start position:0% +take some integer X we'll choose it +later it's just going to be big enough + + align:start position:0% +later it's just going to be big enough + + + align:start position:0% +later it's just going to be big enough +something like n and we have one giant + + align:start position:0% +something like n and we have one giant + + + align:start position:0% +something like n and we have one giant +Square which is x * x + 1 minus one uh + + align:start position:0% +Square which is x * x + 1 minus one uh + + + align:start position:0% +Square which is x * x + 1 minus one uh +by they're all squares so by the same + + align:start position:0% +by they're all squares so by the same + + + align:start position:0% +by they're all squares so by the same +amount and then we're going to take + + align:start position:0% +amount and then we're going to take + + + align:start position:0% +amount and then we're going to take +these medium siiz squares of size X plus + + align:start position:0% +these medium siiz squares of size X plus + + + align:start position:0% +these medium siiz squares of size X plus +one and these small squares so much + + align:start position:0% +one and these small squares so much + + + align:start position:0% +one and these small squares so much +smaller of size X and because uh this is + + align:start position:0% +smaller of size X and because uh this is + + + align:start position:0% +smaller of size X and because uh this is +just one smaller uh than what it's + + align:start position:0% +just one smaller uh than what it's + + + align:start position:0% +just one smaller uh than what it's +supposed to be I mean if it was x * X+ 1 + + align:start position:0% +supposed to be I mean if it was x * X+ 1 + + + align:start position:0% +supposed to be I mean if it was x * X+ 1 +it would come to here uh and so when you + + align:start position:0% +it would come to here uh and so when you + + + align:start position:0% +it would come to here uh and so when you +pack these guys up you go just one too + + align:start position:0% +pack these guys up you go just one too + + + align:start position:0% +pack these guys up you go just one too +far there but there's exactly enough + + align:start position:0% +far there but there's exactly enough + + + align:start position:0% +far there but there's exactly enough +room for one more if I put X plus one + + align:start position:0% +room for one more if I put X plus one + + + align:start position:0% +room for one more if I put X plus one +extra this is X that's the one and so on + + align:start position:0% +extra this is X that's the one and so on + + + align:start position:0% +extra this is X that's the one and so on +so uh this leaves as a Gap a + + align:start position:0% +so uh this leaves as a Gap a + + + align:start position:0% +so uh this leaves as a Gap a +rectangle now this is not the only + + align:start position:0% +rectangle now this is not the only + + + align:start position:0% +rectangle now this is not the only +solution these guys could slide down but + + align:start position:0% +solution these guys could slide down but + + + align:start position:0% +solution these guys could slide down but +you can show that will only make your + + align:start position:0% +you can show that will only make your + + + align:start position:0% +you can show that will only make your +life harder and the paper does that um + + align:start position:0% +life harder and the paper does that um + + + align:start position:0% +life harder and the paper does that um +that's sort of the easy part of the + + align:start position:0% +that's sort of the easy part of the + + + align:start position:0% +that's sort of the easy part of the +proof and so now you're left with a + + align:start position:0% +proof and so now you're left with a + + + align:start position:0% +proof and so now you're left with a +rectangle which is one by this thing uh + + align:start position:0% +rectangle which is one by this thing uh + + + align:start position:0% +rectangle which is one by this thing uh +you multiply everything + + align:start position:0% + + + + align:start position:0% + +by 3B plus T because that was what we + + align:start position:0% +by 3B plus T because that was what we + + + align:start position:0% +by 3B plus T because that was what we +wanted one of our Dimensions to be the + + align:start position:0% +wanted one of our Dimensions to be the + + + align:start position:0% +wanted one of our Dimensions to be the +smaller one uh so that scale up the + + align:start position:0% +smaller one uh so that scale up the + + + align:start position:0% +smaller one uh so that scale up the +rectangle and then the horizontal the + + align:start position:0% +rectangle and then the horizontal the + + + align:start position:0% +rectangle and then the horizontal the +widths may not match exactly uh but if + + align:start position:0% +widths may not match exactly uh but if + + + align:start position:0% +widths may not match exactly uh but if +if there's too much space here and we + + align:start position:0% +if there's too much space here and we + + + align:start position:0% +if there's too much space here and we +just set X to be large enough then + + align:start position:0% +just set X to be large enough then + + + align:start position:0% +just set X to be large enough then +there'll be extra space and just throw + + align:start position:0% +there'll be extra space and just throw + + + align:start position:0% +there'll be extra space and just throw +in a bunch of B byb blocks there to fill + + align:start position:0% +in a bunch of B byb blocks there to fill + + + align:start position:0% +in a bunch of B byb blocks there to fill +up the extra space you can figure out + + align:start position:0% +up the extra space you can figure out + + + align:start position:0% +up the extra space you can figure out +how much extra space there is and fill + + align:start position:0% +how much extra space there is and fill + + + align:start position:0% +how much extra space there is and fill +it in uh so there you go packing squares + + align:start position:0% +it in uh so there you go packing squares + + + align:start position:0% +it in uh so there you go packing squares +into a square and this is strong NP + + align:start position:0% +into a square and this is strong NP + + + align:start position:0% +into a square and this is strong NP +hardness so this even when the squares + + align:start position:0% +hardness so this even when the squares + + + align:start position:0% +hardness so this even when the squares +are only of polinomial area this problem + + align:start position:0% +are only of polinomial area this problem + + + align:start position:0% +are only of polinomial area this problem +is hard which is actually the case you + + align:start position:0% +is hard which is actually the case you + + + align:start position:0% +is hard which is actually the case you +care about when each of these one by one + + align:start position:0% +care about when each of these one by one + + + align:start position:0% +care about when each of these one by one +squares is a processor now this was not + + align:start position:0% +squares is a processor now this was not + + + align:start position:0% +squares is a processor now this was not +exact packing and so you might worry oh + + align:start position:0% +exact packing and so you might worry oh + + + align:start position:0% +exact packing and so you might worry oh +what if I rotate the squares and then + + align:start position:0% +what if I rotate the squares and then + + + align:start position:0% +what if I rotate the squares and then +crazy things can happen probably not but + + align:start position:0% +crazy things can happen probably not but + + + align:start position:0% +crazy things can happen probably not but +um you could also just compute how much + + align:start position:0% +um you could also just compute how much + + + align:start position:0% +um you could also just compute how much +extra slop there is because you know the + + align:start position:0% +extra slop there is because you know the + + + align:start position:0% +extra slop there is because you know the +area of the uh input squares and you + + align:start position:0% +area of the uh input squares and you + + + align:start position:0% +area of the uh input squares and you +know the area of the target square and + + align:start position:0% +know the area of the target square and + + + align:start position:0% +know the area of the target square and +just add a whole bunch of one by one uh + + align:start position:0% +just add a whole bunch of one by one uh + + + align:start position:0% +just add a whole bunch of one by one uh +little chips and that will fill in + + align:start position:0% +little chips and that will fill in + + + align:start position:0% +little chips and that will fill in +exactly the space then you have exact + + align:start position:0% +exactly the space then you have exact + + + align:start position:0% +exactly the space then you have exact +packing then you don't even have to + + align:start position:0% +packing then you don't even have to + + + align:start position:0% +packing then you don't even have to +worry about rotation so that makes proof + + align:start position:0% +worry about rotation so that makes proof + + + align:start position:0% +worry about rotation so that makes proof +even cleaner I think that wasn't in the + + align:start position:0% +even cleaner I think that wasn't in the + + + align:start position:0% +even cleaner I think that wasn't in the +original paper but it's a nice little + + align:start position:0% +original paper but it's a nice little + + + align:start position:0% +original paper but it's a nice little +addition and that is our packing through + + align:start position:0% +addition and that is our packing through + + + align:start position:0% +addition and that is our packing through +three partition next class we'll do more + + align:start position:0% +three partition next class we'll do more + + + align:start position:0% +three partition next class we'll do more +more three partition for different types + + align:start position:0% +more three partition for different types + + + align:start position:0% +more three partition for different types +of problems so in case you lose uh lots + + align:start position:0% +of problems so in case you lose uh lots + + + align:start position:0% +of problems so in case you lose uh lots +of pieces in your jig jiga puzzle we + + align:start position:0% +of pieces in your jig jiga puzzle we + + + align:start position:0% +of pieces in your jig jiga puzzle we +have the one piece jigsaw + + align:start position:0% +have the one piece jigsaw + + + align:start position:0% +have the one piece jigsaw +puzzle uh this is all the pieces are in + + align:start position:0% +puzzle uh this is all the pieces are in + + + align:start position:0% +puzzle uh this is all the pieces are in +one giant connected mess and still it is + + align:start position:0% +one giant connected mess and still it is + + + align:start position:0% +one giant connected mess and still it is +not so trivial to + + align:start position:0% +not so trivial to + + + align:start position:0% +not so trivial to +solve + + align:start position:0% + + + + align:start position:0% + +wow all right this is the one piece jiga + + align:start position:0% +wow all right this is the one piece jiga + + + align:start position:0% +wow all right this is the one piece jiga +puzzle in solve + + align:start position:0% +puzzle in solve + + + align:start position:0% +puzzle in solve +State it's a Simpsons Edition + + align:start position:0% +State it's a Simpsons Edition + + + align:start position:0% +State it's a Simpsons Edition +so you get it + + align:start position:0% +so you get it + + + align:start position:0% +so you get it +then you put + + align:start position:0% + + + + align:start position:0% + +thater + + align:start position:0% + + + + align:start position:0% + +tada \ No newline at end of file diff --git a/_0PrwAbgoMA.txt b/_0PrwAbgoMA.txt new file mode 100644 index 0000000000000000000000000000000000000000..07dc6358b56863ba80b979cf229a21cd10024b68 --- /dev/null +++ b/_0PrwAbgoMA.txt @@ -0,0 +1,547 @@ +align:start position:0% + +now let's consider the case where an + + align:start position:0% +now let's consider the case where an + + + align:start position:0% +now let's consider the case where an +object is undergoing circular motion but + + align:start position:0% +object is undergoing circular motion but + + + align:start position:0% +object is undergoing circular motion but +in this motion let's again introduce our + + align:start position:0% +in this motion let's again introduce our + + + align:start position:0% +in this motion let's again introduce our +polar coordinate system our hat and beta + + align:start position:0% +polar coordinate system our hat and beta + + + align:start position:0% +polar coordinate system our hat and beta +hat we now want to consider the case + + align:start position:0% +hat we now want to consider the case + + + align:start position:0% +hat we now want to consider the case +where d theta/dt is not constant and + + align:start position:0% +where d theta/dt is not constant and + + + align:start position:0% +where d theta/dt is not constant and +what does that mean + + align:start position:0% +what does that mean + + + align:start position:0% +what does that mean +that means that if d theta/dt is + + align:start position:0% +that means that if d theta/dt is + + + align:start position:0% +that means that if d theta/dt is +positive for instance the object is + + align:start position:0% +positive for instance the object is + + + align:start position:0% +positive for instance the object is +speeding up in this direction or if d + + align:start position:0% +speeding up in this direction or if d + + + align:start position:0% +speeding up in this direction or if d +theta/dt is negative the object is + + align:start position:0% +theta/dt is negative the object is + + + align:start position:0% +theta/dt is negative the object is +slowing down in this direction that's + + align:start position:0% +slowing down in this direction that's + + + align:start position:0% +slowing down in this direction that's +one type of case so in this instant we + + align:start position:0% +one type of case so in this instant we + + + align:start position:0% +one type of case so in this instant we +always know that there's a radial + + align:start position:0% +always know that there's a radial + + + align:start position:0% +always know that there's a radial +component at any instant given by minus + + align:start position:0% +component at any instant given by minus + + + align:start position:0% +component at any instant given by minus +R D theta DT squared but because it's + + align:start position:0% +R D theta DT squared but because it's + + + align:start position:0% +R D theta DT squared but because it's +speeding up and slowing down there is + + align:start position:0% +speeding up and slowing down there is + + + align:start position:0% +speeding up and slowing down there is +now a non zero tangential component to + + align:start position:0% +now a non zero tangential component to + + + align:start position:0% +now a non zero tangential component to +the acceleration and let's see where + + align:start position:0% +the acceleration and let's see where + + + align:start position:0% +the acceleration and let's see where +that comes from so again if we write our + + align:start position:0% +that comes from so again if we write our + + + align:start position:0% +that comes from so again if we write our +velocity vector as our D theta DT theta + + align:start position:0% +velocity vector as our D theta DT theta + + + align:start position:0% +velocity vector as our D theta DT theta +hat this is the product of two terms and + + align:start position:0% +hat this is the product of two terms and + + + align:start position:0% +hat this is the product of two terms and +because it's a product of two terms we + + align:start position:0% +because it's a product of two terms we + + + align:start position:0% +because it's a product of two terms we +need the product rule from calculus and + + align:start position:0% +need the product rule from calculus and + + + align:start position:0% +need the product rule from calculus and +when we take a derivative so the + + align:start position:0% +when we take a derivative so the + + + align:start position:0% +when we take a derivative so the +derivative will be the derivative of the + + align:start position:0% +derivative will be the derivative of the + + + align:start position:0% +derivative will be the derivative of the +first term times the second term plus + + align:start position:0% +first term times the second term plus + + + align:start position:0% +first term times the second term plus +the first term times the derivative of + + align:start position:0% +the first term times the derivative of + + + align:start position:0% +the first term times the derivative of +the second term + + align:start position:0% +the second term + + + align:start position:0% +the second term +now we've already analyzed this piece + + align:start position:0% +now we've already analyzed this piece + + + align:start position:0% +now we've already analyzed this piece +and this was precisely - our D theta DT + + align:start position:0% +and this was precisely - our D theta DT + + + align:start position:0% +and this was precisely - our D theta DT +quantity squared R hat that was the + + align:start position:0% +quantity squared R hat that was the + + + align:start position:0% +quantity squared R hat that was the +always the non zero ten radial + + align:start position:0% +always the non zero ten radial + + + align:start position:0% +always the non zero ten radial +acceleration but now let's analyze this + + align:start position:0% +acceleration but now let's analyze this + + + align:start position:0% +acceleration but now let's analyze this +piece separately R for our circular + + align:start position:0% +piece separately R for our circular + + + align:start position:0% +piece separately R for our circular +motion is a constant so it's only D + + align:start position:0% +motion is a constant so it's only D + + + align:start position:0% +motion is a constant so it's only D +theta DT that is no longer constant so + + align:start position:0% +theta DT that is no longer constant so + + + align:start position:0% +theta DT that is no longer constant so +we simply take a second derivative and + + align:start position:0% +we simply take a second derivative and + + + align:start position:0% +we simply take a second derivative and +so we get R times d squared theta DT + + align:start position:0% +so we get R times d squared theta DT + + + align:start position:0% +so we get R times d squared theta DT +squared theta hat + + align:start position:0% +squared theta hat + + + align:start position:0% +squared theta hat +and that is our acceleration notice that + + align:start position:0% +and that is our acceleration notice that + + + align:start position:0% +and that is our acceleration notice that +it has two components we'll write the + + align:start position:0% +it has two components we'll write the + + + align:start position:0% +it has two components we'll write the +first component a theta that's its + + align:start position:0% +first component a theta that's its + + + align:start position:0% +first component a theta that's its +tangential component theta hat plus the + + align:start position:0% +tangential component theta hat plus the + + + align:start position:0% +tangential component theta hat plus the +radial component a R that's again the + + align:start position:0% +radial component a R that's again the + + + align:start position:0% +radial component a R that's again the +component and because this is a vector R + + align:start position:0% +component and because this is a vector R + + + align:start position:0% +component and because this is a vector R +hat where the a theta is now the second + + align:start position:0% +hat where the a theta is now the second + + + align:start position:0% +hat where the a theta is now the second +derivative of D theta squared DT squared + + align:start position:0% +derivative of D theta squared DT squared + + + align:start position:0% +derivative of D theta squared DT squared +and just to remind you that a R is minus + + align:start position:0% +and just to remind you that a R is minus + + + align:start position:0% +and just to remind you that a R is minus +AR D theta DT squared so when d squared + + align:start position:0% +AR D theta DT squared so when d squared + + + align:start position:0% +AR D theta DT squared so when d squared +theta DT squared is positive it means D + + align:start position:0% +theta DT squared is positive it means D + + + align:start position:0% +theta DT squared is positive it means D +theta DT is increasing and so if this + + align:start position:0% +theta DT is increasing and so if this + + + align:start position:0% +theta DT is increasing and so if this +object is going in this clockwise + + align:start position:0% +object is going in this clockwise + + + align:start position:0% +object is going in this clockwise +direction we call that speeding up in a + + align:start position:0% +direction we call that speeding up in a + + + align:start position:0% +direction we call that speeding up in a +similar fashion it's easy to understand + + align:start position:0% +similar fashion it's easy to understand + + + align:start position:0% +similar fashion it's easy to understand +that when d squared theta DT squared is + + align:start position:0% +that when d squared theta DT squared is + + + align:start position:0% +that when d squared theta DT squared is +negative then D theta DT is decreasing + + align:start position:0% +negative then D theta DT is decreasing + + + align:start position:0% +negative then D theta DT is decreasing +and so it can be slowing down or if it + + align:start position:0% +and so it can be slowing down or if it + + + align:start position:0% +and so it can be slowing down or if it +slows down and stops you can start to + + align:start position:0% +slows down and stops you can start to + + + align:start position:0% +slows down and stops you can start to +move in the other direction so again the + + align:start position:0% +move in the other direction so again the + + + align:start position:0% +move in the other direction so again the +acceleration has two components a + + align:start position:0% +acceleration has two components a + + + align:start position:0% +acceleration has two components a +tangential component and that depends on + + align:start position:0% +tangential component and that depends on + + + align:start position:0% +tangential component and that depends on +the type of circular motion we're + + align:start position:0% +the type of circular motion we're + + + align:start position:0% +the type of circular motion we're +talking about whether d theta DT is + + align:start position:0% +talking about whether d theta DT is + + + align:start position:0% +talking about whether d theta DT is +constant or not it always has a nonzero + + align:start position:0% +constant or not it always has a nonzero + + + align:start position:0% +constant or not it always has a nonzero +inward radial component given by Muk the + + align:start position:0% +inward radial component given by Muk the + + + align:start position:0% +inward radial component given by Muk the +component minus R D theta T squared + + align:start position:0% +component minus R D theta T squared + + + align:start position:0% +component minus R D theta T squared +regardless of whether it's speeding up + + align:start position:0% +regardless of whether it's speeding up + + + align:start position:0% +regardless of whether it's speeding up +or slowing down \ No newline at end of file diff --git a/_GgdGtQME1I.txt b/_GgdGtQME1I.txt new file mode 100644 index 0000000000000000000000000000000000000000..d2a0f78dde5a46ca009e9dd2b8853b8a2cb7a90d --- /dev/null +++ b/_GgdGtQME1I.txt @@ -0,0 +1,16003 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so today I'm going to + + align:start position:0% +ocw.mit.edu okay so today I'm going to + + + align:start position:0% +ocw.mit.edu okay so today I'm going to +sort of take a more empirical approach + + align:start position:0% +sort of take a more empirical approach + + + align:start position:0% +sort of take a more empirical approach +and I feel like I've done a lot of + + align:start position:0% +and I feel like I've done a lot of + + + align:start position:0% +and I feel like I've done a lot of +theory in this class so today I'm going + + align:start position:0% +theory in this class so today I'm going + + + align:start position:0% +theory in this class so today I'm going +to I'm going to play through the hands + + align:start position:0% +to I'm going to play through the hands + + + align:start position:0% +to I'm going to play through the hands +of an online tney so that I played and + + align:start position:0% +of an online tney so that I played and + + + align:start position:0% +of an online tney so that I played and +sort of show you the most interesting + + align:start position:0% +sort of show you the most interesting + + + align:start position:0% +sort of show you the most interesting +hands and show you exactly what I did I + + align:start position:0% +hands and show you exactly what I did I + + + align:start position:0% +hands and show you exactly what I did I +don't think I'm going to finish the + + align:start position:0% +don't think I'm going to finish the + + + align:start position:0% +don't think I'm going to finish the +whole T day but um I'm going to go + + align:start position:0% +whole T day but um I'm going to go + + + align:start position:0% +whole T day but um I'm going to go +through the first part and I'm only + + align:start position:0% +through the first part and I'm only + + + align:start position:0% +through the first part and I'm only +going to talk about a few theoretical + + align:start position:0% +going to talk about a few theoretical + + + align:start position:0% +going to talk about a few theoretical +Concepts but mostly just go through the + + align:start position:0% +Concepts but mostly just go through the + + + align:start position:0% +Concepts but mostly just go through the +T + + align:start position:0% +T + + + align:start position:0% +T +okay so it's it's a $55 buyin tournament + + align:start position:0% +okay so it's it's a $55 buyin tournament + + + align:start position:0% +okay so it's it's a $55 buyin tournament +on party poker and it's a fairly small + + align:start position:0% +on party poker and it's a fairly small + + + align:start position:0% +on party poker and it's a fairly small +field so this is a tournament I I played + + align:start position:0% +field so this is a tournament I I played + + + align:start position:0% +field so this is a tournament I I played +recently um + + align:start position:0% +recently um + + + align:start position:0% +recently um +um and okay so so let's just get into + + align:start position:0% +um and okay so so let's just get into + + + align:start position:0% +um and okay so so let's just get into +the hands I'm only going to show you the + + align:start position:0% +the hands I'm only going to show you the + + + align:start position:0% +the hands I'm only going to show you the +the hands where I did something at the + + align:start position:0% +the hands where I did something at the + + + align:start position:0% +the hands where I did something at the +start and we will start with a bit of + + align:start position:0% +start and we will start with a bit of + + + align:start position:0% +start and we will start with a bit of +theory okay so this is this is the + + align:start position:0% +theory okay so this is this is the + + + align:start position:0% +theory okay so this is this is the +situation it's folded to this player and + + align:start position:0% +situation it's folded to this player and + + + align:start position:0% +situation it's folded to this player and +so we have king queen here and it's a + + align:start position:0% +so we have king queen here and it's a + + + align:start position:0% +so we have king queen here and it's a +hand where we're in position and he + + align:start position:0% +hand where we're in position and he + + + align:start position:0% +hand where we're in position and he +raised from late enough position where I + + align:start position:0% +raised from late enough position where I + + + align:start position:0% +raised from late enough position where I +think our hand is too good to fold so if + + align:start position:0% +think our hand is too good to fold so if + + + align:start position:0% +think our hand is too good to fold so if +dream if dream crushed if if the guy who + + align:start position:0% +dream if dream crushed if if the guy who + + + align:start position:0% +dream if dream crushed if if the guy who +raised was from under the gun let's say + + align:start position:0% +raised was from under the gun let's say + + + align:start position:0% +raised was from under the gun let's say +then um then I might have I I probably + + align:start position:0% +then um then I might have I I probably + + + align:start position:0% +then um then I might have I I probably +would have folded because against an + + align:start position:0% +would have folded because against an + + + align:start position:0% +would have folded because against an +under the gun range king queen offly + + align:start position:0% +under the gun range king queen offly + + + align:start position:0% +under the gun range king queen offly +kind of gets crushed but against a range + + align:start position:0% +kind of gets crushed but against a range + + + align:start position:0% +kind of gets crushed but against a range +from High Jack minus one or low Jack I + + align:start position:0% +from High Jack minus one or low Jack I + + + align:start position:0% +from High Jack minus one or low Jack I +think king queen is good enough to play + + align:start position:0% +think king queen is good enough to play + + + align:start position:0% +think king queen is good enough to play +but the question is sort of what do we + + align:start position:0% +but the question is sort of what do we + + + align:start position:0% +but the question is sort of what do we +do do we raise do we call I don't think + + align:start position:0% +do do we raise do we call I don't think + + + align:start position:0% +do do we raise do we call I don't think +folding is the end of the world you know + + align:start position:0% +folding is the end of the world you know + + + align:start position:0% +folding is the end of the world you know +I think it's slightly profitable to play + + align:start position:0% +I think it's slightly profitable to play + + + align:start position:0% +I think it's slightly profitable to play +but it's not like you're giving up a ton + + align:start position:0% +but it's not like you're giving up a ton + + + align:start position:0% +but it's not like you're giving up a ton +of equity by folding this so what do we + + align:start position:0% +of equity by folding this so what do we + + + align:start position:0% +of equity by folding this so what do we +do okay so I'm going to start out with a + + align:start position:0% +do okay so I'm going to start out with a + + + align:start position:0% +do okay so I'm going to start out with a +bit of + + align:start position:0% +bit of + + + align:start position:0% +bit of +theory so I haven't really talked about + + align:start position:0% +theory so I haven't really talked about + + + align:start position:0% +theory so I haven't really talked about +this so this is so I want to talk a bit + + align:start position:0% +this so this is so I want to talk a bit + + + align:start position:0% +this so this is so I want to talk a bit +a bit about pre flop reising Theory so + + align:start position:0% +a bit about pre flop reising Theory so + + + align:start position:0% +a bit about pre flop reising Theory so +in this situation I don't want to just + + align:start position:0% +in this situation I don't want to just + + + align:start position:0% +in this situation I don't want to just +talk about what to do with this hand + + align:start position:0% +talk about what to do with this hand + + + align:start position:0% +talk about what to do with this hand +right this is how throughout this class + + align:start position:0% +right this is how throughout this class + + + align:start position:0% +right this is how throughout this class +I've been saying we shouldn't think + + align:start position:0% +I've been saying we shouldn't think + + + align:start position:0% +I've been saying we shouldn't think +about poker we should always think about + + align:start position:0% +about poker we should always think about + + + align:start position:0% +about poker we should always think about +the general situation what's the range + + align:start position:0% +the general situation what's the range + + + align:start position:0% +the general situation what's the range +of hands we could have what's the range + + align:start position:0% +of hands we could have what's the range + + + align:start position:0% +of hands we could have what's the range +of hands they could have and how do how + + align:start position:0% +of hands they could have and how do how + + + align:start position:0% +of hands they could have and how do how +should both players play their overall + + align:start position:0% +should both players play their overall + + + align:start position:0% +should both players play their overall +strategy with their entire range of + + align:start position:0% +strategy with their entire range of + + + align:start position:0% +strategy with their entire range of +hands so okay so there's a few + + align:start position:0% +hands so okay so there's a few + + + align:start position:0% +hands so okay so there's a few +interesting things to think about here + + align:start position:0% +interesting things to think about here + + + align:start position:0% +interesting things to think about here +um so there's sort of a dilemma so if we + + align:start position:0% +um so there's sort of a dilemma so if we + + + align:start position:0% +um so there's sort of a dilemma so if we +think about our overall strategy um okay + + align:start position:0% +think about our overall strategy um okay + + + align:start position:0% +think about our overall strategy um okay +so first first thing you notice is how + + align:start position:0% +so first first thing you notice is how + + + align:start position:0% +so first first thing you notice is how +many bets deep is it effective how many + + align:start position:0% +many bets deep is it effective how many + + + align:start position:0% +many bets deep is it effective how many +how what's the stack size effectively + + align:start position:0% +how what's the stack size effectively + + + align:start position:0% +how what's the stack size effectively +it's about it's about 28 right I think + + align:start position:0% +it's about it's about 28 right I think + + + align:start position:0% +it's about it's about 28 right I think +uh so yeah we have about the same amount + + align:start position:0% +uh so yeah we have about the same amount + + + align:start position:0% +uh so yeah we have about the same amount +of chips we have like 28 and a half big + + align:start position:0% +of chips we have like 28 and a half big + + + align:start position:0% +of chips we have like 28 and a half big +mines that's clear to everyone so it's + + align:start position:0% +mines that's clear to everyone so it's + + + align:start position:0% +mines that's clear to everyone so it's +important that it's fairly deep here so + + align:start position:0% +important that it's fairly deep here so + + + align:start position:0% +important that it's fairly deep here so +the the stack size the effective stack + + align:start position:0% +the the stack size the effective stack + + + align:start position:0% +the the stack size the effective stack +size is 282 big blinds + + align:start position:0% +size is 282 big blinds + + + align:start position:0% +size is 282 big blinds +and so what's the issue it's sometimes + + align:start position:0% +and so what's the issue it's sometimes + + + align:start position:0% +and so what's the issue it's sometimes +in this spot we have a hand that's good + + align:start position:0% +in this spot we have a hand that's good + + + align:start position:0% +in this spot we have a hand that's good +enough imp plied odds to play in + + align:start position:0% +enough imp plied odds to play in + + + align:start position:0% +enough imp plied odds to play in +position but it's not really like a good + + align:start position:0% +position but it's not really like a good + + + align:start position:0% +position but it's not really like a good +hand that we're trying to raise and make + + align:start position:0% +hand that we're trying to raise and make + + + align:start position:0% +hand that we're trying to raise and make +the pot bigger with like an example of + + align:start position:0% +the pot bigger with like an example of + + + align:start position:0% +the pot bigger with like an example of +this is like King Jack suited or like + + align:start position:0% +this is like King Jack suited or like + + + align:start position:0% +this is like King Jack suited or like +king queen off I think is a good example + + align:start position:0% +king queen off I think is a good example + + + align:start position:0% +king queen off I think is a good example +too it's a hand that's good enough to + + align:start position:0% +too it's a hand that's good enough to + + + align:start position:0% +too it's a hand that's good enough to +play but not a hand that's good enough + + align:start position:0% +play but not a hand that's good enough + + + align:start position:0% +play but not a hand that's good enough +that we necessarily want to raise and + + align:start position:0% +that we necessarily want to raise and + + + align:start position:0% +that we necessarily want to raise and +make the pot + + align:start position:0% +make the pot + + + align:start position:0% +make the pot +bigger on the other hand sometimes we + + align:start position:0% +bigger on the other hand sometimes we + + + align:start position:0% +bigger on the other hand sometimes we +have a hand that you want to raise and + + align:start position:0% +have a hand that you want to raise and + + + align:start position:0% +have a hand that you want to raise and +hope you get along with like Aces right + + align:start position:0% +hope you get along with like Aces right + + + align:start position:0% +hope you get along with like Aces right +so we do have the we have these sort of + + align:start position:0% +so we do have the we have these sort of + + + align:start position:0% +so we do have the we have these sort of +two types of hands that we want to play + + align:start position:0% +two types of hands that we want to play + + + align:start position:0% +two types of hands that we want to play +in the situation but if we play + + align:start position:0% +in the situation but if we play + + + align:start position:0% +in the situation but if we play +according to our hand it can become too + + align:start position:0% +according to our hand it can become too + + + align:start position:0% +according to our hand it can become too +predictable right so so this is like a + + align:start position:0% +predictable right so so this is like a + + + align:start position:0% +predictable right so so this is like a +somewhat intuitive strategy so you know + + align:start position:0% +somewhat intuitive strategy so you know + + + align:start position:0% +somewhat intuitive strategy so you know +let's suppose this was our strategy + + align:start position:0% +let's suppose this was our strategy + + + align:start position:0% +let's suppose this was our strategy +let's suppose our strategy was with the + + align:start position:0% +let's suppose our strategy was with the + + + align:start position:0% +let's suppose our strategy was with the +best hands that we're hoping to get it + + align:start position:0% +best hands that we're hoping to get it + + + align:start position:0% +best hands that we're hoping to get it +all in with let's say in this spot uh + + align:start position:0% +all in with let's say in this spot uh + + + align:start position:0% +all in with let's say in this spot uh +pocket 10 plus and Ace King I think + + align:start position:0% +pocket 10 plus and Ace King I think + + + align:start position:0% +pocket 10 plus and Ace King I think +that's reasonable as um as the set of + + align:start position:0% +that's reasonable as um as the set of + + + align:start position:0% +that's reasonable as um as the set of +hands were willing to and happy to go + + align:start position:0% +hands were willing to and happy to go + + + align:start position:0% +hands were willing to and happy to go +all in with so pocket TS plus a + + align:start position:0% +all in with so pocket TS plus a + + + align:start position:0% +all in with so pocket TS plus a +and then we call with uh pocket fives + + align:start position:0% +and then we call with uh pocket fives + + + align:start position:0% +and then we call with uh pocket fives +plus Ace jack off Ace 10 suited king + + align:start position:0% +plus Ace jack off Ace 10 suited king + + + align:start position:0% +plus Ace jack off Ace 10 suited king +queen off um it's so this I'd say this + + align:start position:0% +queen off um it's so this I'd say this + + + align:start position:0% +queen off um it's so this I'd say this +is a reasonable strategy to play but um + + align:start position:0% +is a reasonable strategy to play but um + + + align:start position:0% +is a reasonable strategy to play but um +what are some problems with this sort of + + align:start position:0% +what are some problems with this sort of + + + align:start position:0% +what are some problems with this sort of +intutive exploitative + + align:start position:0% + + + + align:start position:0% + +strategy yeah people are just going to + + align:start position:0% +strategy yeah people are just going to + + + align:start position:0% +strategy yeah people are just going to +hold to your Aces and pick up money from + + align:start position:0% +hold to your Aces and pick up money from + + + align:start position:0% +hold to your Aces and pick up money from +you when you don't + + align:start position:0% +you when you don't + + + align:start position:0% +you when you don't +havep okay great yeah um good good so + + align:start position:0% +havep okay great yeah um good good so + + + align:start position:0% +havep okay great yeah um good good so +yeah so that's a yeah that's good point + + align:start position:0% +yeah so that's a yeah that's good point + + + align:start position:0% +yeah so that's a yeah that's good point +so basically right so people if we if we + + align:start position:0% +so basically right so people if we if we + + + align:start position:0% +so basically right so people if we if we +only raise with pocket 10 plus people + + align:start position:0% +only raise with pocket 10 plus people + + + align:start position:0% +only raise with pocket 10 plus people +can just fold pretty easily right + + align:start position:0% +can just fold pretty easily right + + + align:start position:0% +can just fold pretty easily right +because they know that we have a great + + align:start position:0% +because they know that we have a great + + + align:start position:0% +because they know that we have a great +hand whatever we raised good um okay + + align:start position:0% +hand whatever we raised good um okay + + + align:start position:0% +hand whatever we raised good um okay +what's another issue this one's a bit + + align:start position:0% +what's another issue this one's a bit + + + align:start position:0% +what's another issue this one's a bit +more subtle what's what's sort of + + align:start position:0% +more subtle what's what's sort of + + + align:start position:0% +more subtle what's what's sort of +another issue right so one issue is when + + align:start position:0% +another issue right so one issue is when + + + align:start position:0% +another issue right so one issue is when +we raise it's obviously we have a great + + align:start position:0% +we raise it's obviously we have a great + + + align:start position:0% +we raise it's obviously we have a great +hand and so on a similar line another + + align:start position:0% +hand and so on a similar line another + + + align:start position:0% +hand and so on a similar line another +issue + + align:start position:0% +issue + + + align:start position:0% +issue +yeah oh sorry yeah if we call them they + + align:start position:0% +yeah oh sorry yeah if we call them they + + + align:start position:0% +yeah oh sorry yeah if we call them they +know we're weak right exactly okay good + + align:start position:0% +know we're weak right exactly okay good + + + align:start position:0% +know we're weak right exactly okay good +yeah so so the uh an almost bigger issue + + align:start position:0% +yeah so so the uh an almost bigger issue + + + align:start position:0% +yeah so so the uh an almost bigger issue +here is if we play like this when we + + align:start position:0% +here is if we play like this when we + + + align:start position:0% +here is if we play like this when we +call people know we can't have Aces so + + align:start position:0% +call people know we can't have Aces so + + + align:start position:0% +call people know we can't have Aces so +you know one of the guys behind like + + align:start position:0% +you know one of the guys behind like + + + align:start position:0% +you know one of the guys behind like +this guy all might just be able to raise + + align:start position:0% +this guy all might just be able to raise + + + align:start position:0% +this guy all might just be able to raise +and they they're going to know we're + + align:start position:0% +and they they're going to know we're + + + align:start position:0% +and they they're going to know we're +going to be fairly weak and we're going + + align:start position:0% +going to be fairly weak and we're going + + + align:start position:0% +going to be fairly weak and we're going +to have to fold most of the time right + + align:start position:0% +to have to fold most of the time right + + + align:start position:0% +to have to fold most of the time right +so basically this is not a really + + align:start position:0% +so basically this is not a really + + + align:start position:0% +so basically this is not a really +balanced strategy so what can we do well + + align:start position:0% +balanced strategy so what can we do well + + + align:start position:0% +balanced strategy so what can we do well +we could Raise Some assort of hands from + + align:start position:0% +we could Raise Some assort of hands from + + + align:start position:0% +we could Raise Some assort of hands from +the call category to balance it out we + + align:start position:0% +the call category to balance it out we + + + align:start position:0% +the call category to balance it out we +could call some hands from the raise + + align:start position:0% +could call some hands from the raise + + + align:start position:0% +could call some hands from the raise +category to small percent of the time + + align:start position:0% +category to small percent of the time + + + align:start position:0% +category to small percent of the time +like play a randomized strategy where + + align:start position:0% +like play a randomized strategy where + + + align:start position:0% +like play a randomized strategy where +you raise Aces 80% of the time and call + + align:start position:0% +you raise Aces 80% of the time and call + + + align:start position:0% +you raise Aces 80% of the time and call +Aces 20% of the time to balance it out + + align:start position:0% +Aces 20% of the time to balance it out + + + align:start position:0% +Aces 20% of the time to balance it out +um there's some other more extreme + + align:start position:0% +um there's some other more extreme + + + align:start position:0% +um there's some other more extreme +things you can do that I don't think are + + align:start position:0% +things you can do that I don't think are + + + align:start position:0% +things you can do that I don't think are +good in this situation but are + + align:start position:0% +good in this situation but are + + + align:start position:0% +good in this situation but are +reasonable when the stack size is + + align:start position:0% +reasonable when the stack size is + + + align:start position:0% +reasonable when the stack size is +different so I think if it's shallower + + align:start position:0% +different so I think if it's shallower + + + align:start position:0% +different so I think if it's shallower +let's say only 20 big blinds deep then + + align:start position:0% +let's say only 20 big blinds deep then + + + align:start position:0% +let's say only 20 big blinds deep then +just raising All Hands just raising the + + align:start position:0% +just raising All Hands just raising the + + + align:start position:0% +just raising All Hands just raising the +top x% of hands is a decent strategy + + align:start position:0% +top x% of hands is a decent strategy + + + align:start position:0% +top x% of hands is a decent strategy +because it 20 big blinds is sort of + + align:start position:0% +because it 20 big blinds is sort of + + + align:start position:0% +because it 20 big blinds is sort of +shallow enough where if you raise you + + align:start position:0% +shallow enough where if you raise you + + + align:start position:0% +shallow enough where if you raise you +you're kind of committing your whole + + align:start position:0% +you're kind of committing your whole + + + align:start position:0% +you're kind of committing your whole +stack anyway and if it's deeper then + + align:start position:0% +stack anyway and if it's deeper then + + + align:start position:0% +stack anyway and if it's deeper then +like if it's 100 big blinds deep some + + align:start position:0% +like if it's 100 big blinds deep some + + + align:start position:0% +like if it's 100 big blinds deep some +players will like to call 100% of the + + align:start position:0% +players will like to call 100% of the + + + align:start position:0% +players will like to call 100% of the +hands they'll just never raise um I + + align:start position:0% +hands they'll just never raise um I + + + align:start position:0% +hands they'll just never raise um I +don't think it's like the optimal + + align:start position:0% +don't think it's like the optimal + + + align:start position:0% +don't think it's like the optimal +strategy but it's not an unreasonable + + align:start position:0% +strategy but it's not an unreasonable + + + align:start position:0% +strategy but it's not an unreasonable +strategy when if you're 100 big blinds + + align:start position:0% +strategy when if you're 100 big blinds + + + align:start position:0% +strategy when if you're 100 big blinds +deep and you have position it's not + + align:start position:0% +deep and you have position it's not + + + align:start position:0% +deep and you have position it's not +terrible and then your range is + + align:start position:0% +terrible and then your range is + + + align:start position:0% +terrible and then your range is +completely disguised because you're + + align:start position:0% +completely disguised because you're + + + align:start position:0% +completely disguised because you're +playing all your hands the same pre flop + + align:start position:0% +playing all your hands the same pre flop + + + align:start position:0% +playing all your hands the same pre flop +so these are some reasonable solution + + align:start position:0% +so these are some reasonable solution + + + align:start position:0% +so these are some reasonable solution +ideas um so here's a sort of a better + + align:start position:0% +ideas um so here's a sort of a better + + + align:start position:0% +ideas um so here's a sort of a better +solution so so here's so this will sound + + align:start position:0% +solution so so here's so this will sound + + + align:start position:0% +solution so so here's so this will sound +really cool um compared to the previous + + align:start position:0% +really cool um compared to the previous + + + align:start position:0% +really cool um compared to the previous +slide which is instead of raising some + + align:start position:0% +slide which is instead of raising some + + + align:start position:0% +slide which is instead of raising some +of the call hands as as a bluff + + align:start position:0% +of the call hands as as a bluff + + + align:start position:0% +of the call hands as as a bluff +essentially to balance out the times we + + align:start position:0% +essentially to balance out the times we + + + align:start position:0% +essentially to balance out the times we +raise with a good hand what if we + + align:start position:0% +raise with a good hand what if we + + + align:start position:0% +raise with a good hand what if we +actually we Bluff rais the best hands + + align:start position:0% +actually we Bluff rais the best hands + + + align:start position:0% +actually we Bluff rais the best hands +that aren't good enough to call so let + + align:start position:0% +that aren't good enough to call so let + + + align:start position:0% +that aren't good enough to call so let +me just so we can look at this again + + align:start position:0% +me just so we can look at this again + + + align:start position:0% +me just so we can look at this again +right so our strategy was we're raising + + align:start position:0% +right so our strategy was we're raising + + + align:start position:0% +right so our strategy was we're raising +for Value AKA we're raising hoping to + + align:start position:0% +for Value AKA we're raising hoping to + + + align:start position:0% +for Value AKA we're raising hoping to +get called with t plus and Ace King + + align:start position:0% +get called with t plus and Ace King + + + align:start position:0% +get called with t plus and Ace King +we're we're calling with sort of the + + align:start position:0% +we're we're calling with sort of the + + + align:start position:0% +we're we're calling with sort of the +pretty good hands like pocket fives plus + + align:start position:0% +pretty good hands like pocket fives plus + + + align:start position:0% +pretty good hands like pocket fives plus +Ace Jack Ace 10 suited king queen off + + align:start position:0% +Ace Jack Ace 10 suited king queen off + + + align:start position:0% +Ace Jack Ace 10 suited king queen off +and then we're going to we're going to + + align:start position:0% +and then we're going to we're going to + + + align:start position:0% +and then we're going to we're going to +Bluff raise hands that aren't positive + + align:start position:0% +Bluff raise hands that aren't positive + + + align:start position:0% +Bluff raise hands that aren't positive +expectancy to call so like pocket fours + + align:start position:0% +expectancy to call so like pocket fours + + + align:start position:0% +expectancy to call so like pocket fours +Ace 10 off ace9 suited hands that are + + align:start position:0% +Ace 10 off ace9 suited hands that are + + + align:start position:0% +Ace 10 off ace9 suited hands that are +even weaker than the call hands but in + + align:start position:0% +even weaker than the call hands but in + + + align:start position:0% +even weaker than the call hands but in +some sense if we if we Bluff raise with + + align:start position:0% +some sense if we if we Bluff raise with + + + align:start position:0% +some sense if we if we Bluff raise with +these hands the benefit is we're sort of + + align:start position:0% +these hands the benefit is we're sort of + + + align:start position:0% +these hands the benefit is we're sort of +not wasting them right like let's say + + align:start position:0% +not wasting them right like let's say + + + align:start position:0% +not wasting them right like let's say +with these better hands like let's say + + align:start position:0% +with these better hands like let's say + + + align:start position:0% +with these better hands like let's say +with Ace jack off I and my opponent goes + + align:start position:0% +with Ace jack off I and my opponent goes + + + align:start position:0% +with Ace jack off I and my opponent goes +all in well I'm probably going to have + + align:start position:0% +all in well I'm probably going to have + + + align:start position:0% +all in well I'm probably going to have +to fold in this situation for 28 and a + + align:start position:0% +to fold in this situation for 28 and a + + + align:start position:0% +to fold in this situation for 28 and a +half big blinds so I've sort of like + + align:start position:0% +half big blinds so I've sort of like + + + align:start position:0% +half big blinds so I've sort of like +wasted my Ace Jack whereas you know if I + + align:start position:0% +wasted my Ace Jack whereas you know if I + + + align:start position:0% +wasted my Ace Jack whereas you know if I +did it with Ace 10 instead then I get to + + align:start position:0% +did it with Ace 10 instead then I get to + + + align:start position:0% +did it with Ace 10 instead then I get to +call with my Ace Jack which I know is + + align:start position:0% +call with my Ace Jack which I know is + + + align:start position:0% +call with my Ace Jack which I know is +plus EAS to call and not waste such a + + align:start position:0% +plus EAS to call and not waste such a + + + align:start position:0% +plus EAS to call and not waste such a +good hand Bluff raising so this is a + + align:start position:0% +good hand Bluff raising so this is a + + + align:start position:0% +good hand Bluff raising so this is a +very important Concept in poker it's + + align:start position:0% +very important Concept in poker it's + + + align:start position:0% +very important Concept in poker it's +called polarizing um and in general you + + align:start position:0% +called polarizing um and in general you + + + align:start position:0% +called polarizing um and in general you +know it's a sound strategy right by this + + align:start position:0% +know it's a sound strategy right by this + + + align:start position:0% +know it's a sound strategy right by this +like wasting argument I'm saying + + align:start position:0% +like wasting argument I'm saying + + + align:start position:0% +like wasting argument I'm saying +I'm talking about polarizing sounds like + + align:start position:0% +I'm talking about polarizing sounds like + + + align:start position:0% +I'm talking about polarizing sounds like +a pretty reasonable strategy right + + align:start position:0% +a pretty reasonable strategy right + + + align:start position:0% +a pretty reasonable strategy right +because it it ensures that you're not + + align:start position:0% +because it it ensures that you're not + + + align:start position:0% +because it it ensures that you're not +wasting your medium strength hands to to + + align:start position:0% +wasting your medium strength hands to to + + + align:start position:0% +wasting your medium strength hands to to +Bluff raids so so what's what's an issue + + align:start position:0% +Bluff raids so so what's what's an issue + + + align:start position:0% +Bluff raids so so what's what's an issue +with it so it can be exploited if your + + align:start position:0% +with it so it can be exploited if your + + + align:start position:0% +with it so it can be exploited if your +opponent um calls your three bit so uh + + align:start position:0% +opponent um calls your three bit so uh + + + align:start position:0% +opponent um calls your three bit so uh +so does anyone actually see does anyone + + align:start position:0% +so does anyone actually see does anyone + + + align:start position:0% +so does anyone actually see does anyone +actually see so let's say in this case + + align:start position:0% +actually see so let's say in this case + + + align:start position:0% +actually see so let's say in this case +suppose this was my strategy uh so I'm + + align:start position:0% +suppose this was my strategy uh so I'm + + + align:start position:0% +suppose this was my strategy uh so I'm +raising pocket 10 plus + + align:start position:0% +raising pocket 10 plus + + + align:start position:0% +raising pocket 10 plus +and uh and Ace King and I'm Bluff + + align:start position:0% +and uh and Ace King and I'm Bluff + + + align:start position:0% +and uh and Ace King and I'm Bluff +raising the hands I listed here against + + align:start position:0% +raising the hands I listed here against + + + align:start position:0% +raising the hands I listed here against +okay I'll give I'll give a $20 gift + + align:start position:0% +okay I'll give I'll give a $20 gift + + + align:start position:0% +okay I'll give I'll give a $20 gift +certificate to so like what's a specific + + align:start position:0% +certificate to so like what's a specific + + + align:start position:0% +certificate to so like what's a specific +board less say where someone can explain + + align:start position:0% +board less say where someone can explain + + + align:start position:0% +board less say where someone can explain +my strategy if this was my specific + + align:start position:0% +my strategy if this was my specific + + + align:start position:0% +my strategy if this was my specific +strategy um this is just for + + align:start position:0% +strategy um this is just for + + + align:start position:0% +strategy um this is just for +illustration but like so so look at my + + align:start position:0% +illustration but like so so look at my + + + align:start position:0% +illustration but like so so look at my +exact range and Can someone say sort of + + align:start position:0% +exact range and Can someone say sort of + + + align:start position:0% +exact range and Can someone say sort of +what's what's a very bad flop for my + + align:start position:0% +what's what's a very bad flop for my + + + align:start position:0% +what's what's a very bad flop for my +range + + align:start position:0% + + + + align:start position:0% + +H yeah uh it flops High cards because + + align:start position:0% +H yeah uh it flops High cards because + + + align:start position:0% +H yeah uh it flops High cards because +they'll be thinking your range is + + align:start position:0% +they'll be thinking your range is + + + align:start position:0% +they'll be thinking your range is +generally High cards but those are bit + + align:start position:0% +generally High cards but those are bit + + + align:start position:0% +generally High cards but those are bit +lower uh right so so if there's High + + align:start position:0% +lower uh right so so if there's High + + + align:start position:0% +lower uh right so so if there's High +cards but we do have lots of Aces and + + align:start position:0% +cards but we do have lots of Aces and + + + align:start position:0% +cards but we do have lots of Aces and +Kings right like if the Flop comes like + + align:start position:0% +Kings right like if the Flop comes like + + + align:start position:0% +Kings right like if the Flop comes like +um like if there's an ace then it's it's + + align:start position:0% +um like if there's an ace then it's it's + + + align:start position:0% +um like if there's an ace then it's it's +pretty good for our range right um even + + align:start position:0% +pretty good for our range right um even + + + align:start position:0% +pretty good for our range right um even +though they might be able to fold easily + + align:start position:0% +though they might be able to fold easily + + + align:start position:0% +though they might be able to fold easily +but we're still going to win the pot but + + align:start position:0% +but we're still going to win the pot but + + + align:start position:0% +but we're still going to win the pot but +um but what is like a specific what's a + + align:start position:0% +um but what is like a specific what's a + + + align:start position:0% +um but what is like a specific what's a +specific is yeah like 567 somewhere in + + align:start position:0% +specific is yeah like 567 somewhere in + + + align:start position:0% +specific is yeah like 567 somewhere in +between okay good so 567 is kind of bad + + align:start position:0% +between okay good so 567 is kind of bad + + + align:start position:0% +between okay good so 567 is kind of bad +for us right because our range basically + + align:start position:0% +for us right because our range basically + + + align:start position:0% +for us right because our range basically +contains no fives no sixes no sevens um + + align:start position:0% +contains no fives no sixes no sevens um + + + align:start position:0% +contains no fives no sixes no sevens um +but even 5 six s we still have like a + + align:start position:0% +but even 5 six s we still have like a + + + align:start position:0% +but even 5 six s we still have like a +bigger pair quite often so what's like + + align:start position:0% +bigger pair quite often so what's like + + + align:start position:0% +bigger pair quite often so what's like +an even worst case I yeah High plus draw + + align:start position:0% +an even worst case I yeah High plus draw + + + align:start position:0% +an even worst case I yeah High plus draw +or a high straight draw straight draw uh + + align:start position:0% +or a high straight draw straight draw uh + + + align:start position:0% +or a high straight draw straight draw uh +yeah but we can have those right we have + + align:start position:0% +yeah but we can have those right we have + + + align:start position:0% +yeah but we can have those right we have +A9 suited in our range we have King 10 + + align:start position:0% +A9 suited in our range we have King 10 + + + align:start position:0% +A9 suited in our range we have King 10 +suited in our range something like a low + + align:start position:0% +suited in our range something like a low + + + align:start position:0% +suited in our range something like a low +pair like 448 + + align:start position:0% +pair like 448 + + + align:start position:0% +pair like 448 +um yeah we don't have fours or eights + + align:start position:0% +um yeah we don't have fours or eights + + + align:start position:0% +um yeah we don't have fours or eights +but you know on those boards like pocket + + align:start position:0% +but you know on those boards like pocket + + + align:start position:0% +but you know on those boards like pocket +Jacks even like Ace King high is a + + align:start position:0% +Jacks even like Ace King high is a + + + align:start position:0% +Jacks even like Ace King high is a +pretty good hand and pocket Jacks + + align:start position:0% +pretty good hand and pocket Jacks + + + align:start position:0% +pretty good hand and pocket Jacks +there's there's something very specific + + align:start position:0% +there's there's something very specific + + + align:start position:0% +there's there's something very specific +we're missing I mean this is just for + + align:start position:0% +we're missing I mean this is just for + + + align:start position:0% +we're missing I mean this is just for +this example but um yeah maybe if they + + align:start position:0% +this example but um yeah maybe if they + + + align:start position:0% +this example but um yeah maybe if they +have right okay good good yeah so that's + + align:start position:0% +have right okay good good yeah so that's + + + align:start position:0% +have right okay good good yeah so that's +sort of what I was looking for yeah you + + align:start position:0% +sort of what I was looking for yeah you + + + align:start position:0% +sort of what I was looking for yeah you +can come you can come get this now if + + align:start position:0% +can come you can come get this now if + + + align:start position:0% +can come you can come get this now if +you want um essentially like so suppose + + align:start position:0% +you want um essentially like so suppose + + + align:start position:0% +you want um essentially like so suppose +this was our exact strategy if the board + + align:start position:0% +this was our exact strategy if the board + + + align:start position:0% +this was our exact strategy if the board +comes Queen High then essentially they + + align:start position:0% +comes Queen High then essentially they + + + align:start position:0% +comes Queen High then essentially they +know that we are is pretty bad because + + align:start position:0% +know that we are is pretty bad because + + + align:start position:0% +know that we are is pretty bad because +we don't ever have a queen and we we I + + align:start position:0% +we don't ever have a queen and we we I + + + align:start position:0% +we don't ever have a queen and we we I +mean we could have Kings or Aces but all + + align:start position:0% +mean we could have Kings or Aces but all + + + align:start position:0% +mean we could have Kings or Aces but all +of our other pairs are going to be + + align:start position:0% +of our other pairs are going to be + + + align:start position:0% +of our other pairs are going to be +smaller than Queen so I mean this is + + align:start position:0% +smaller than Queen so I mean this is + + + align:start position:0% +smaller than Queen so I mean this is +just a specific example but I'm saying + + align:start position:0% +just a specific example but I'm saying + + + align:start position:0% +just a specific example but I'm saying +polarizing is in general a good concept + + align:start position:0% +polarizing is in general a good concept + + + align:start position:0% +polarizing is in general a good concept +by this argument that you're not wasting + + align:start position:0% +by this argument that you're not wasting + + + align:start position:0% +by this argument that you're not wasting +your good hands but it can be exploited + + align:start position:0% +your good hands but it can be exploited + + + align:start position:0% +your good hands but it can be exploited +if your opponent knows the specific way + + align:start position:0% +if your opponent knows the specific way + + + align:start position:0% +if your opponent knows the specific way +in which you're polarizing and they just + + align:start position:0% +in which you're polarizing and they just + + + align:start position:0% +in which you're polarizing and they just +call your rays and see the Flop and + + align:start position:0% +call your rays and see the Flop and + + + align:start position:0% +call your rays and see the Flop and +they'll be able to play very well on the + + align:start position:0% +they'll be able to play very well on the + + + align:start position:0% +they'll be able to play very well on the +flops still even if if you have some + + align:start position:0% +flops still even if if you have some + + + align:start position:0% +flops still even if if you have some +good hands and some Bluffs um it can + + align:start position:0% +good hands and some Bluffs um it can + + + align:start position:0% +good hands and some Bluffs um it can +also be bad against unpredictable + + align:start position:0% +also be bad against unpredictable + + + align:start position:0% +also be bad against unpredictable +opponents because um by the by the like + + align:start position:0% +opponents because um by the by the like + + + align:start position:0% +opponents because um by the by the like +Ace Jack Ace 10 argument again let's say + + align:start position:0% +Ace Jack Ace 10 argument again let's say + + + align:start position:0% +Ace Jack Ace 10 argument again let's say +you three bet with Ace 10 instead of Ace + + align:start position:0% +you three bet with Ace 10 instead of Ace + + + align:start position:0% +you three bet with Ace 10 instead of Ace +Jack as an attempt to polarize but let's + + align:start position:0% +Jack as an attempt to polarize but let's + + + align:start position:0% +Jack as an attempt to polarize but let's +say your opponent is kind of bad and + + align:start position:0% +say your opponent is kind of bad and + + + align:start position:0% +say your opponent is kind of bad and +they might make a loose call in the + + align:start position:0% +they might make a loose call in the + + + align:start position:0% +they might make a loose call in the +situation with Ace 10 then you you you + + align:start position:0% +situation with Ace 10 then you you you + + + align:start position:0% +situation with Ace 10 then you you you +would have really hoped to have Ace Jack + + align:start position:0% +would have really hoped to have Ace Jack + + + align:start position:0% +would have really hoped to have Ace Jack +instead of Ace 10 if they're going to + + align:start position:0% +instead of Ace 10 if they're going to + + + align:start position:0% +instead of Ace 10 if they're going to +call your raay with Ace 10 I mean if you + + align:start position:0% +call your raay with Ace 10 I mean if you + + + align:start position:0% +call your raay with Ace 10 I mean if you +so if you're polarizing you're sort of + + align:start position:0% +so if you're polarizing you're sort of + + + align:start position:0% +so if you're polarizing you're sort of +assuming your opponent is going to play + + align:start position:0% +assuming your opponent is going to play + + + align:start position:0% +assuming your opponent is going to play +reasonably right so the point is the + + align:start position:0% +reasonably right so the point is the + + + align:start position:0% +reasonably right so the point is the +reason why I don't want to sort of waste + + align:start position:0% +reason why I don't want to sort of waste + + + align:start position:0% +reason why I don't want to sort of waste +Ace Jack by raising is because my + + align:start position:0% +Ace Jack by raising is because my + + + align:start position:0% +Ace Jack by raising is because my +opponent's probably going to fold Ace 10 + + align:start position:0% +opponent's probably going to fold Ace 10 + + + align:start position:0% +opponent's probably going to fold Ace 10 +but what if they might call ace10 then I + + align:start position:0% +but what if they might call ace10 then I + + + align:start position:0% +but what if they might call ace10 then I +really would have wished I I Rea a jack + + align:start position:0% +really would have wished I I Rea a jack + + + align:start position:0% +really would have wished I I Rea a jack +so okay the short answer is I'm not + + align:start position:0% +so okay the short answer is I'm not + + + align:start position:0% +so okay the short answer is I'm not +going to give a conclusive formula on + + align:start position:0% +going to give a conclusive formula on + + + align:start position:0% +going to give a conclusive formula on +how to play this situation because the + + align:start position:0% +how to play this situation because the + + + align:start position:0% +how to play this situation because the +short answer is it's complicated and I + + align:start position:0% +short answer is it's complicated and I + + + align:start position:0% +short answer is it's complicated and I +don't think anyone essentially knows + + align:start position:0% +don't think anyone essentially knows + + + align:start position:0% +don't think anyone essentially knows +what the optimal strategy is yet but um + + align:start position:0% +what the optimal strategy is yet but um + + + align:start position:0% +what the optimal strategy is yet but um +um in practice I think just raising a + + align:start position:0% +um in practice I think just raising a + + + align:start position:0% +um in practice I think just raising a +mix of hands from the call category + + align:start position:0% +mix of hands from the call category + + + align:start position:0% +mix of hands from the call category +mostly the offsuit hands which have + + align:start position:0% +mostly the offsuit hands which have + + + align:start position:0% +mostly the offsuit hands which have +worse imp ply dods is is pretty good as + + align:start position:0% +worse imp ply dods is is pretty good as + + + align:start position:0% +worse imp ply dods is is pretty good as +part of your like Bluff raising range + + align:start position:0% +part of your like Bluff raising range + + + align:start position:0% +part of your like Bluff raising range +and calling the best hands from the + + align:start position:0% +and calling the best hands from the + + + align:start position:0% +and calling the best hands from the +raise category like Aces like trapping a + + align:start position:0% +raise category like Aces like trapping a + + + align:start position:0% +raise category like Aces like trapping a +small percent of the time just calling + + align:start position:0% +small percent of the time just calling + + + align:start position:0% +small percent of the time just calling +Aces maybe a fifth of the time so that + + align:start position:0% +Aces maybe a fifth of the time so that + + + align:start position:0% +Aces maybe a fifth of the time so that +sometimes you have it when you call so + + align:start position:0% +sometimes you have it when you call so + + + align:start position:0% +sometimes you have it when you call so +that people can't just re ra when you + + align:start position:0% +that people can't just re ra when you + + + align:start position:0% +that people can't just re ra when you +call and also raise some of the best + + align:start position:0% +call and also raise some of the best + + + align:start position:0% +call and also raise some of the best +hands that aren't plus C to call so so + + align:start position:0% +hands that aren't plus C to call so so + + + align:start position:0% +hands that aren't plus C to call so so +polarize a bit essentially the short + + align:start position:0% +polarize a bit essentially the short + + + align:start position:0% +polarize a bit essentially the short +answer is it's complicated you need to + + align:start position:0% +answer is it's complicated you need to + + + align:start position:0% +answer is it's complicated you need to +do you need to do a bit of everything + + align:start position:0% +do you need to do a bit of everything + + + align:start position:0% +do you need to do a bit of everything +with all sorts of hands but um I just + + align:start position:0% +with all sorts of hands but um I just + + + align:start position:0% +with all sorts of hands but um I just +wanted to sort of talk about how + + align:start position:0% +wanted to sort of talk about how + + + align:start position:0% +wanted to sort of talk about how +complicated this situation can be all + + align:start position:0% +complicated this situation can be all + + + align:start position:0% +complicated this situation can be all +right uh so okay so let's get back to + + align:start position:0% +right uh so okay so let's get back to + + + align:start position:0% +right uh so okay so let's get back to +the hand so what I decided to do here + + align:start position:0% +the hand so what I decided to do here + + + align:start position:0% +the hand so what I decided to do here +was following the the thing I said about + + align:start position:0% +was following the the thing I said about + + + align:start position:0% +was following the the thing I said about +re raising with offit hands I decided to + + align:start position:0% +re raising with offit hands I decided to + + + align:start position:0% +re raising with offit hands I decided to +so I decided to raise here to 555 and so + + align:start position:0% +so I decided to raise here to 555 and so + + + align:start position:0% +so I decided to raise here to 555 and so +I think this is about the right sizing + + align:start position:0% +I think this is about the right sizing + + + align:start position:0% +I think this is about the right sizing +cuz we're making it about 2.5 times his + + align:start position:0% +cuz we're making it about 2.5 times his + + + align:start position:0% +cuz we're making it about 2.5 times his +raise and essentially we're bluffing + + align:start position:0% +raise and essentially we're bluffing + + + align:start position:0% +raise and essentially we're bluffing +here and our hand is good enough where + + align:start position:0% +here and our hand is good enough where + + + align:start position:0% +here and our hand is good enough where +it's not the end of the world if they + + align:start position:0% +it's not the end of the world if they + + + align:start position:0% +it's not the end of the world if they +call cuz we have a lot of chances to hit + + align:start position:0% +call cuz we have a lot of chances to hit + + + align:start position:0% +call cuz we have a lot of chances to hit +Top pair and if we do we're probably + + align:start position:0% +Top pair and if we do we're probably + + + align:start position:0% +Top pair and if we do we're probably +good because they're probably going on + + align:start position:0% +good because they're probably going on + + + align:start position:0% +good because they're probably going on +with Ace King or Ace Queen pre flop but + + align:start position:0% +with Ace King or Ace Queen pre flop but + + + align:start position:0% +with Ace King or Ace Queen pre flop but +essentially we're bluffing I'm + + align:start position:0% +essentially we're bluffing I'm + + + align:start position:0% +essentially we're bluffing I'm +definitely hoping he folds and and he + + align:start position:0% +definitely hoping he folds and and he + + + align:start position:0% +definitely hoping he folds and and he +does so okay we take down the pot + + align:start position:0% +does so okay we take down the pot + + + align:start position:0% +does so okay we take down the pot +uh okay so so the very next hand I + + align:start position:0% +uh okay so so the very next hand I + + + align:start position:0% +uh okay so so the very next hand I +actually just noticed this during uh + + align:start position:0% +actually just noticed this during uh + + + align:start position:0% +actually just noticed this during uh +when I was replaying through the hands + + align:start position:0% +when I was replaying through the hands + + + align:start position:0% +when I was replaying through the hands +so I didn't notice this I didn't notice + + align:start position:0% +so I didn't notice this I didn't notice + + + align:start position:0% +so I didn't notice this I didn't notice +this during the tournament actually but + + align:start position:0% +this during the tournament actually but + + + align:start position:0% +this during the tournament actually but +so what do you notice it's actually + + align:start position:0% +so what do you notice it's actually + + + align:start position:0% +so what do you notice it's actually +we're actually in the in the exact same + + align:start position:0% +we're actually in the in the exact same + + + align:start position:0% +we're actually in the in the exact same +situation together right but we have + + align:start position:0% +situation together right but we have + + + align:start position:0% +situation together right but we have +different cards so it's good that you + + align:start position:0% +different cards so it's good that you + + + align:start position:0% +different cards so it's good that you +know we thought about our overall + + align:start position:0% +know we thought about our overall + + + align:start position:0% +know we thought about our overall +strategy when we played that hand + + align:start position:0% +strategy when we played that hand + + + align:start position:0% +strategy when we played that hand +because you will end up in the same + + align:start position:0% +because you will end up in the same + + + align:start position:0% +because you will end up in the same +situation again with different cards so + + align:start position:0% +situation again with different cards so + + + align:start position:0% +situation again with different cards so +okay so along the same lines so you know + + align:start position:0% +okay so along the same lines so you know + + + align:start position:0% +okay so along the same lines so you know +but at the time you know I was probably + + align:start position:0% +but at the time you know I was probably + + + align:start position:0% +but at the time you know I was probably +playing like 15 tables or more so I + + align:start position:0% +playing like 15 tables or more so I + + + align:start position:0% +playing like 15 tables or more so I +wasn't really paying attention I + + align:start position:0% +wasn't really paying attention I + + + align:start position:0% +wasn't really paying attention I +probably didn't I probably didn't + + align:start position:0% +probably didn't I probably didn't + + + align:start position:0% +probably didn't I probably didn't +remember that I R raised my opponent the + + align:start position:0% +remember that I R raised my opponent the + + + align:start position:0% +remember that I R raised my opponent the +hand before but playing through this it + + align:start position:0% +hand before but playing through this it + + + align:start position:0% +hand before but playing through this it +actually yielded a really good result + + align:start position:0% +actually yielded a really good result + + + align:start position:0% +actually yielded a really good result +cuz what happened was they didn't + + align:start position:0% +cuz what happened was they didn't + + + align:start position:0% +cuz what happened was they didn't +believe my three bet the second time + + align:start position:0% +believe my three bet the second time + + + align:start position:0% +believe my three bet the second time +around and they went all in with you + + align:start position:0% +around and they went all in with you + + + align:start position:0% +around and they went all in with you +know pocket sevens is not a terrible + + align:start position:0% +know pocket sevens is not a terrible + + + align:start position:0% +know pocket sevens is not a terrible +hand but it's definitely I think a + + align:start position:0% +hand but it's definitely I think a + + + align:start position:0% +hand but it's definitely I think a +weaker hand than they would usually go + + align:start position:0% +weaker hand than they would usually go + + + align:start position:0% +weaker hand than they would usually go +on there with but I guess they didn't + + align:start position:0% +on there with but I guess they didn't + + + align:start position:0% +on there with but I guess they didn't +believe my Rays after the previous hand + + align:start position:0% +believe my Rays after the previous hand + + + align:start position:0% +believe my Rays after the previous hand +so this also sort of illustrates the + + align:start position:0% +so this also sort of illustrates the + + + align:start position:0% +so this also sort of illustrates the +importance of like you said of sometimes + + align:start position:0% +importance of like you said of sometimes + + + align:start position:0% +importance of like you said of sometimes +having a bad hand when you re ra so that + + align:start position:0% +having a bad hand when you re ra so that + + + align:start position:0% +having a bad hand when you re ra so that +people will give you action when you do + + align:start position:0% +people will give you action when you do + + + align:start position:0% +people will give you action when you do +have a good hand like P + + align:start position:0% + + + + align:start position:0% + +Jacks okay so okay so let's go on and so + + align:start position:0% +Jacks okay so okay so let's go on and so + + + align:start position:0% +Jacks okay so okay so let's go on and so +I'm only playing through the hands that + + align:start position:0% +I'm only playing through the hands that + + + align:start position:0% +I'm only playing through the hands that +I that I essentially played at the start + + align:start position:0% +I that I essentially played at the start + + + align:start position:0% +I that I essentially played at the start +of the tournament so so we doubled up + + align:start position:0% +of the tournament so so we doubled up + + + align:start position:0% +of the tournament so so we doubled up +the starting stack was 3,000 we've got + + align:start position:0% +the starting stack was 3,000 we've got + + + align:start position:0% +the starting stack was 3,000 we've got +6,000 now we get a queen we + + align:start position:0% +6,000 now we get a queen we + + + align:start position:0% +6,000 now we get a queen we +raise and we get Co here and here this + + align:start position:0% +raise and we get Co here and here this + + + align:start position:0% +raise and we get Co here and here this +guy makes it so this is a different + + align:start position:0% +guy makes it so this is a different + + + align:start position:0% +guy makes it so this is a different +player cuz we eliminated the guy who + + align:start position:0% +player cuz we eliminated the guy who + + + align:start position:0% +player cuz we eliminated the guy who +used to sit here and they make it + + align:start position:0% +used to sit here and they make it + + + align:start position:0% +used to sit here and they make it +755 and I decide to fold here I think + + align:start position:0% +755 and I decide to fold here I think + + + align:start position:0% +755 and I decide to fold here I think +Ace queen off suit is just a bit too + + align:start position:0% +Ace queen off suit is just a bit too + + + align:start position:0% +Ace queen off suit is just a bit too +weak I think going all in is it wouldn't + + align:start position:0% +weak I think going all in is it wouldn't + + + align:start position:0% +weak I think going all in is it wouldn't +be terrible but I think where when we + + align:start position:0% +be terrible but I think where when we + + + align:start position:0% +be terrible but I think where when we +raised from fairly early position under + + align:start position:0% +raised from fairly early position under + + + align:start position:0% +raised from fairly early position under +the gun plus one and this hijack called + + align:start position:0% +the gun plus one and this hijack called + + + align:start position:0% +the gun plus one and this hijack called +they're not going to be doing this as a + + align:start position:0% +they're not going to be doing this as a + + + align:start position:0% +they're not going to be doing this as a +bluff very often and they're re raised + + align:start position:0% +bluff very often and they're re raised + + + align:start position:0% +bluff very often and they're re raised +to 755 I think usually commits them it's + + align:start position:0% +to 755 I think usually commits them it's + + + align:start position:0% +to 755 I think usually commits them it's +not not guaranteed that they're going to + + align:start position:0% +not not guaranteed that they're going to + + + align:start position:0% +not not guaranteed that they're going to +they're going to go all in if we're + + align:start position:0% +they're going to go all in if we're + + + align:start position:0% +they're going to go all in if we're +they're going to call us if we go all in + + align:start position:0% +they're going to call us if we go all in + + + align:start position:0% +they're going to call us if we go all in +but I think most likely they will and + + align:start position:0% +but I think most likely they will and + + + align:start position:0% +but I think most likely they will and +they're going to be ahead of our range + + align:start position:0% +they're going to be ahead of our range + + + align:start position:0% +they're going to be ahead of our range +so I decided to fold it's a fairly tight + + align:start position:0% +so I decided to fold it's a fairly tight + + + align:start position:0% +so I decided to fold it's a fairly tight +fold so does a + + align:start position:0% +fold so does a + + + align:start position:0% +fold so does a +sky okay so yeah I'm just going to + + align:start position:0% +sky okay so yeah I'm just going to + + + align:start position:0% +sky okay so yeah I'm just going to +continue playing through my hands from + + align:start position:0% +continue playing through my hands from + + + align:start position:0% +continue playing through my hands from +the tournament if if you have any + + align:start position:0% +the tournament if if you have any + + + align:start position:0% +the tournament if if you have any +questions just stop me and + + align:start position:0% +questions just stop me and + + + align:start position:0% +questions just stop me and +ask okay so this is sort of a weird hand + + align:start position:0% +ask okay so this is sort of a weird hand + + + align:start position:0% +ask okay so this is sort of a weird hand +and I actually think I played this hand + + align:start position:0% +and I actually think I played this hand + + + align:start position:0% +and I actually think I played this hand +quite terribly so okay so this guy calls + + align:start position:0% +quite terribly so okay so this guy calls + + + align:start position:0% +quite terribly so okay so this guy calls +which I said we should never do but I + + align:start position:0% +which I said we should never do but I + + + align:start position:0% +which I said we should never do but I +guess he doesn't take my class um okay + + align:start position:0% +guess he doesn't take my class um okay + + + align:start position:0% +guess he doesn't take my class um okay +so we get Queen 10 here we check we see + + align:start position:0% +so we get Queen 10 here we check we see + + + align:start position:0% +so we get Queen 10 here we check we see +a flop uh so we flop a two over cards a + + align:start position:0% +a flop uh so we flop a two over cards a + + + align:start position:0% +a flop uh so we flop a two over cards a +back door flush draw and a gutter + + align:start position:0% +back door flush draw and a gutter + + + align:start position:0% +back door flush draw and a gutter +straight draw so I decided to lead into + + align:start position:0% +straight draw so I decided to lead into + + + align:start position:0% +straight draw so I decided to lead into +it and so lead lead my draws out hope he + + align:start position:0% +it and so lead lead my draws out hope he + + + align:start position:0% +it and so lead lead my draws out hope he +folds he calls and the turn is a three + + align:start position:0% +folds he calls and the turn is a three + + + align:start position:0% +folds he calls and the turn is a three +and then here so this is where I sort of + + align:start position:0% +and then here so this is where I sort of + + + align:start position:0% +and then here so this is where I sort of +he decided to suckered at me so I talked + + align:start position:0% +he decided to suckered at me so I talked + + + align:start position:0% +he decided to suckered at me so I talked +about how you know he should only be + + align:start position:0% +about how you know he should only be + + + align:start position:0% +about how you know he should only be +doing this if he doesn't respect me cuz + + align:start position:0% +doing this if he doesn't respect me cuz + + + align:start position:0% +doing this if he doesn't respect me cuz +I mean in this case it's you know it's + + align:start position:0% +I mean in this case it's you know it's + + + align:start position:0% +I mean in this case it's you know it's +not a completely insignificant fraction + + align:start position:0% +not a completely insignificant fraction + + + align:start position:0% +not a completely insignificant fraction +of the pot it's like 1 16 so he is + + align:start position:0% +of the pot it's like 1 16 so he is + + + align:start position:0% +of the pot it's like 1 16 so he is +actually getting some substantial + + align:start position:0% +actually getting some substantial + + + align:start position:0% +actually getting some substantial +payment into the pot but it's still + + align:start position:0% +payment into the pot but it's still + + + align:start position:0% +payment into the pot but it's still +fairly small and the main thing it does + + align:start position:0% +fairly small and the main thing it does + + + align:start position:0% +fairly small and the main thing it does +is it gives me an opportunity to check + + align:start position:0% +is it gives me an opportunity to check + + + align:start position:0% +is it gives me an opportunity to check +raay but I'm not going to I don't think + + align:start position:0% +raay but I'm not going to I don't think + + + align:start position:0% +raay but I'm not going to I don't think +I don't think they're going to fold + + align:start position:0% +I don't think they're going to fold + + + align:start position:0% +I don't think they're going to fold +often enough there's a lot of draws + + align:start position:0% +often enough there's a lot of draws + + + align:start position:0% +often enough there's a lot of draws +they're going to call me with and I'm + + align:start position:0% +they're going to call me with and I'm + + + align:start position:0% +they're going to call me with and I'm +going to have to Bluff again on the + + align:start position:0% +going to have to Bluff again on the + + + align:start position:0% +going to have to Bluff again on the +river so I decided to just call which is + + align:start position:0% +river so I decided to just call which is + + + align:start position:0% +river so I decided to just call which is +reasonable so this is where I think I + + align:start position:0% +reasonable so this is where I think I + + + align:start position:0% +reasonable so this is where I think I +played the hand poly so the river + + align:start position:0% +played the hand poly so the river + + + align:start position:0% +played the hand poly so the river +completes a lot of draws but doesn't + + align:start position:0% +completes a lot of draws but doesn't + + + align:start position:0% +completes a lot of draws but doesn't +complete my hand and I just check it + + align:start position:0% +complete my hand and I just check it + + + align:start position:0% +complete my hand and I just check it +down I just check it which the at the + + align:start position:0% +down I just check it which the at the + + + align:start position:0% +down I just check it which the at the +time I didn't lead out because I thought + + align:start position:0% +time I didn't lead out because I thought + + + align:start position:0% +time I didn't lead out because I thought +you know the fact that I only called the + + align:start position:0% +you know the fact that I only called the + + + align:start position:0% +you know the fact that I only called the +turn and suddenly decided to bet big on + + align:start position:0% +turn and suddenly decided to bet big on + + + align:start position:0% +turn and suddenly decided to bet big on +the river would probably get called but + + align:start position:0% +the river would probably get called but + + + align:start position:0% +the river would probably get called but +I think it's just not a balanced way to + + align:start position:0% +I think it's just not a balanced way to + + + align:start position:0% +I think it's just not a balanced way to +play the hand because plenty of times I + + align:start position:0% +play the hand because plenty of times I + + + align:start position:0% +play the hand because plenty of times I +will have clubs or you know or I'll have + + align:start position:0% +will have clubs or you know or I'll have + + + align:start position:0% +will have clubs or you know or I'll have +Jack 10 or something I'll have a Jack + + align:start position:0% +Jack 10 or something I'll have a Jack + + + align:start position:0% +Jack 10 or something I'll have a Jack +and I will want to bet for value and + + align:start position:0% +and I will want to bet for value and + + + align:start position:0% +and I will want to bet for value and +here when I have a hand that essentially + + align:start position:0% +here when I have a hand that essentially + + + align:start position:0% +here when I have a hand that essentially +has no chance of winning the winning the + + align:start position:0% +has no chance of winning the winning the + + + align:start position:0% +has no chance of winning the winning the +handed Showdown like essentially I'm + + align:start position:0% +handed Showdown like essentially I'm + + + align:start position:0% +handed Showdown like essentially I'm +giving up the pot for sure if I check + + align:start position:0% +giving up the pot for sure if I check + + + align:start position:0% +giving up the pot for sure if I check +cuz my queen high will never be good I + + align:start position:0% +cuz my queen high will never be good I + + + align:start position:0% +cuz my queen high will never be good I +should definitely be bluffing so I I + + align:start position:0% +should definitely be bluffing so I I + + + align:start position:0% +should definitely be bluffing so I I +didn't which I regret cuz I let him take + + align:start position:0% +didn't which I regret cuz I let him take + + + align:start position:0% +didn't which I regret cuz I let him take +down the pot with a pair of Threes um + + align:start position:0% +down the pot with a pair of Threes um + + + align:start position:0% +down the pot with a pair of Threes um +but yeah I guess he kind of played that + + align:start position:0% +but yeah I guess he kind of played that + + + align:start position:0% +but yeah I guess he kind of played that +hand well uh he called 83 suited and I + + align:start position:0% +hand well uh he called 83 suited and I + + + align:start position:0% +hand well uh he called 83 suited and I +guess he made money from me cuz I didn't + + align:start position:0% +guess he made money from me cuz I didn't + + + align:start position:0% +guess he made money from me cuz I didn't +play very well from the big + + align:start position:0% +play very well from the big + + + align:start position:0% +play very well from the big +blind uh okay so the next + + align:start position:0% +blind uh okay so the next + + + align:start position:0% +blind uh okay so the next +hand we get King jack off suit here we + + align:start position:0% +hand we get King jack off suit here we + + + align:start position:0% +hand we get King jack off suit here we +open probably one of the weakest hands + + align:start position:0% +open probably one of the weakest hands + + + align:start position:0% +open probably one of the weakest hands +I'm opening from this position I think + + align:start position:0% +I'm opening from this position I think + + + align:start position:0% +I'm opening from this position I think +probably in my recommendations this is + + align:start position:0% +probably in my recommendations this is + + + align:start position:0% +probably in my recommendations this is +not in the list you should open from uh + + align:start position:0% +not in the list you should open from uh + + + align:start position:0% +not in the list you should open from uh +hijack minus one but I decid to open + + align:start position:0% +hijack minus one but I decid to open + + + align:start position:0% +hijack minus one but I decid to open +because I'm bored I guess and we get + + align:start position:0% +because I'm bored I guess and we get + + + align:start position:0% +because I'm bored I guess and we get +three + + align:start position:0% +three + + + align:start position:0% +three +colors okay so the Flop is 4 64 with two + + align:start position:0% +colors okay so the Flop is 4 64 with two + + + align:start position:0% +colors okay so the Flop is 4 64 with two +hearts so I decide to continuation bet + + align:start position:0% +hearts so I decide to continuation bet + + + align:start position:0% +hearts so I decide to continuation bet +here I think it's a fairly marginal spot + + align:start position:0% +here I think it's a fairly marginal spot + + + align:start position:0% +here I think it's a fairly marginal spot +I think just giving up is okay I + + align:start position:0% +I think just giving up is okay I + + + align:start position:0% +I think just giving up is okay I +definitely wouldn't have stabbed at the + + align:start position:0% +definitely wouldn't have stabbed at the + + + align:start position:0% +definitely wouldn't have stabbed at the +pot if I didn't have the if I didn't + + align:start position:0% +pot if I didn't have the if I didn't + + + align:start position:0% +pot if I didn't have the if I didn't +have the King of Hearts but um the fact + + align:start position:0% +have the King of Hearts but um the fact + + + align:start position:0% +have the King of Hearts but um the fact +that I have a back door pretty good + + align:start position:0% +that I have a back door pretty good + + + align:start position:0% +that I have a back door pretty good +flush draw I decided to bet and just + + align:start position:0% +flush draw I decided to bet and just + + + align:start position:0% +flush draw I decided to bet and just +hope that everyone + + align:start position:0% +hope that everyone + + + align:start position:0% +hope that everyone +folds and we do get that which is which + + align:start position:0% +folds and we do get that which is which + + + align:start position:0% +folds and we do get that which is which +is pretty + + align:start position:0% +is pretty + + + align:start position:0% +is pretty +nice okay so so you know our stack is + + align:start position:0% +nice okay so so you know our stack is + + + align:start position:0% +nice okay so so you know our stack is +hovering around the same size we've won + + align:start position:0% +hovering around the same size we've won + + + align:start position:0% +hovering around the same size we've won +some hands lost some hands it's still + + align:start position:0% +some hands lost some hands it's still + + + align:start position:0% +some hands lost some hands it's still +early in the tournament the blinds have + + align:start position:0% +early in the tournament the blinds have + + + align:start position:0% +early in the tournament the blinds have +gone up a bit but it's still far away + + align:start position:0% +gone up a bit but it's still far away + + + align:start position:0% +gone up a bit but it's still far away +from the + + align:start position:0% +from the + + + align:start position:0% +from the +payouts okay so we get Queen Jack on the + + align:start position:0% +payouts okay so we get Queen Jack on the + + + align:start position:0% +payouts okay so we get Queen Jack on the +button and and this guy just goes all in + + align:start position:0% +button and and this guy just goes all in + + + align:start position:0% +button and and this guy just goes all in +for a lot of vets um I mean it's I guess + + align:start position:0% +for a lot of vets um I mean it's I guess + + + align:start position:0% +for a lot of vets um I mean it's I guess +it's not that many it's like + + align:start position:0% +it's not that many it's like + + + align:start position:0% +it's not that many it's like +35 no sorry it's yeah it's about it's + + align:start position:0% +35 no sorry it's yeah it's about it's + + + align:start position:0% +35 no sorry it's yeah it's about it's +about 30 35 right uh so um so I mean I + + align:start position:0% +about 30 35 right uh so um so I mean I + + + align:start position:0% +about 30 35 right uh so um so I mean I +folded here obviously but I thought a + + align:start position:0% +folded here obviously but I thought a + + + align:start position:0% +folded here obviously but I thought a +bit about like his range and you know + + align:start position:0% +bit about like his range and you know + + + align:start position:0% +bit about like his range and you know +it's possible his range is like entirely + + align:start position:0% +it's possible his range is like entirely + + + align:start position:0% +it's possible his range is like entirely +so I talked about this in a previous + + align:start position:0% +so I talked about this in a previous + + + align:start position:0% +so I talked about this in a previous +class when do you want to be going all + + align:start position:0% +class when do you want to be going all + + + align:start position:0% +class when do you want to be going all +in for a huge size it's essentially with + + align:start position:0% +in for a huge size it's essentially with + + + align:start position:0% +in for a huge size it's essentially with +hands that are pretty good to get all in + + align:start position:0% +hands that are pretty good to get all in + + + align:start position:0% +hands that are pretty good to get all in +with pre flop but have terrible post + + align:start position:0% +with pre flop but have terrible post + + + align:start position:0% +with pre flop but have terrible post +flop implied odds in this situation and + + align:start position:0% +flop implied odds in this situation and + + + align:start position:0% +flop implied odds in this situation and +what were the hands that I listed there + + align:start position:0% +what were the hands that I listed there + + + align:start position:0% +what were the hands that I listed there +it's essentially small pairs right like + + align:start position:0% +it's essentially small pairs right like + + + align:start position:0% +it's essentially small pairs right like +pocket twos you really don't want to see + + align:start position:0% +pocket twos you really don't want to see + + + align:start position:0% +pocket twos you really don't want to see +a flop it's it's quite a good hand pre- + + align:start position:0% +a flop it's it's quite a good hand pre- + + + align:start position:0% +a flop it's it's quite a good hand pre- +flop but you really don't want to see a + + align:start position:0% +flop but you really don't want to see a + + + align:start position:0% +flop but you really don't want to see a +flop cuz it's pretty much always three + + align:start position:0% +flop cuz it's pretty much always three + + + align:start position:0% +flop cuz it's pretty much always three +higher cards are going to come and + + align:start position:0% +higher cards are going to come and + + + align:start position:0% +higher cards are going to come and +you're just going to be playing this + + align:start position:0% +you're just going to be playing this + + + align:start position:0% +you're just going to be playing this +guessing game trying to guess whether + + align:start position:0% +guessing game trying to guess whether + + + align:start position:0% +guessing game trying to guess whether +your opponent has a pair and the other + + align:start position:0% +your opponent has a pair and the other + + + align:start position:0% +your opponent has a pair and the other +type of hand is like Ace 2 offit where + + align:start position:0% +type of hand is like Ace 2 offit where + + + align:start position:0% +type of hand is like Ace 2 offit where +once again you you know you have an ace + + align:start position:0% +once again you you know you have an ace + + + align:start position:0% +once again you you know you have an ace +pre- flop which is decent but you're + + align:start position:0% +pre- flop which is decent but you're + + + align:start position:0% +pre- flop which is decent but you're +just going to be playing a guessing game + + align:start position:0% +just going to be playing a guessing game + + + align:start position:0% +just going to be playing a guessing game +on most flops so you know it probably if + + align:start position:0% +on most flops so you know it probably if + + + align:start position:0% +on most flops so you know it probably if +I had a very strong beat on him and I if + + align:start position:0% +I had a very strong beat on him and I if + + + align:start position:0% +I had a very strong beat on him and I if +I had like Jack 10 suited here calling + + align:start position:0% +I had like Jack 10 suited here calling + + + align:start position:0% +I had like Jack 10 suited here calling +is maybe not that bad because you're + + align:start position:0% +is maybe not that bad because you're + + + align:start position:0% +is maybe not that bad because you're +were like a coin flip against ace2 offit + + align:start position:0% +were like a coin flip against ace2 offit + + + align:start position:0% +were like a coin flip against ace2 offit +and you're like a 54% favorite against + + align:start position:0% +and you're like a 54% favorite against + + + align:start position:0% +and you're like a 54% favorite against +pocket 3s so I mean I F it here because + + align:start position:0% +pocket 3s so I mean I F it here because + + + align:start position:0% +pocket 3s so I mean I F it here because +my hand isn't suited and just because + + align:start position:0% +my hand isn't suited and just because + + + align:start position:0% +my hand isn't suited and just because +there's a small chance they're going to + + align:start position:0% +there's a small chance they're going to + + + align:start position:0% +there's a small chance they're going to +have Ace Queen and my read was nowhere + + align:start position:0% +have Ace Queen and my read was nowhere + + + align:start position:0% +have Ace Queen and my read was nowhere +near strong enough to to conclude that + + align:start position:0% +near strong enough to to conclude that + + + align:start position:0% +near strong enough to to conclude that +for sure their range was only small + + align:start position:0% +for sure their range was only small + + + align:start position:0% +for sure their range was only small +pairs in + + align:start position:0% +pairs in + + + align:start position:0% +pairs in +asex + + align:start position:0% +asex + + + align:start position:0% +asex +okay so we lose a bit of chips we're + + align:start position:0% +okay so we lose a bit of chips we're + + + align:start position:0% +okay so we lose a bit of chips we're +blinding down a bit here we got 102 + + align:start position:0% +blinding down a bit here we got 102 + + + align:start position:0% +blinding down a bit here we got 102 +suited and so I call from the big blind + + align:start position:0% +suited and so I call from the big blind + + + align:start position:0% +suited and so I call from the big blind +with four and a half to one odds I think + + align:start position:0% +with four and a half to one odds I think + + + align:start position:0% +with four and a half to one odds I think +this is probably one of the weakest + + align:start position:0% +this is probably one of the weakest + + + align:start position:0% +this is probably one of the weakest +hands I call I might not call like 8 two + + align:start position:0% +hands I call I might not call like 8 two + + + align:start position:0% +hands I call I might not call like 8 two +suited although it's close I mean you + + align:start position:0% +suited although it's close I mean you + + + align:start position:0% +suited although it's close I mean you +can make a case for calling 8 two suited + + align:start position:0% +can make a case for calling 8 two suited + + + align:start position:0% +can make a case for calling 8 two suited +so once again my odds my odds are really + + align:start position:0% +so once again my odds my odds are really + + + align:start position:0% +so once again my odds my odds are really +good but the reverse implied odds do do + + align:start position:0% +good but the reverse implied odds do do + + + align:start position:0% +good but the reverse implied odds do do +sort of work against me quite a bit + + align:start position:0% +sort of work against me quite a bit + + + align:start position:0% +sort of work against me quite a bit +since I'm going to be out of position + + align:start position:0% +since I'm going to be out of position + + + align:start position:0% +since I'm going to be out of position +and I have small cards which will + + align:start position:0% +and I have small cards which will + + + align:start position:0% +and I have small cards which will +usually make a smaller pair than them + + align:start position:0% +usually make a smaller pair than them + + + align:start position:0% +usually make a smaller pair than them +but I decid to call and we FL a flush + + align:start position:0% +but I decid to call and we FL a flush + + + align:start position:0% +but I decid to call and we FL a flush +draw which is pretty good but I'm still + + align:start position:0% +draw which is pretty good but I'm still + + + align:start position:0% +draw which is pretty good but I'm still +going to check because this is a board + + align:start position:0% +going to check because this is a board + + + align:start position:0% +going to check because this is a board +where I'm just going to check to the + + align:start position:0% +where I'm just going to check to the + + + align:start position:0% +where I'm just going to check to the +pre- Flop raiser and let them + + align:start position:0% +pre- Flop raiser and let them + + + align:start position:0% +pre- Flop raiser and let them +continuation BET right so I talked about + + align:start position:0% +continuation BET right so I talked about + + + align:start position:0% +continuation BET right so I talked about +leading in an earlier class and I don't + + align:start position:0% +leading in an earlier class and I don't + + + align:start position:0% +leading in an earlier class and I don't +think this is a board where we should + + align:start position:0% +think this is a board where we should + + + align:start position:0% +think this is a board where we should +leading we should be leading and I think + + align:start position:0% +leading we should be leading and I think + + + align:start position:0% +leading we should be leading and I think +never leading is okay as well so I deci + + align:start position:0% +never leading is okay as well so I deci + + + align:start position:0% +never leading is okay as well so I deci +had to check and they check back so we + + align:start position:0% +had to check and they check back so we + + + align:start position:0% +had to check and they check back so we +turn the flush which is great and we bet + + align:start position:0% +turn the flush which is great and we bet + + + align:start position:0% +turn the flush which is great and we bet +600 into + + align:start position:0% +600 into + + + align:start position:0% +600 into +1080 so unfortunately we don't get any + + align:start position:0% +1080 so unfortunately we don't get any + + + align:start position:0% +1080 so unfortunately we don't get any +action so we take it + + align:start position:0% + + + + align:start position:0% + +down okay uh so the next I think this is + + align:start position:0% +down okay uh so the next I think this is + + + align:start position:0% +down okay uh so the next I think this is +one Orbit + + align:start position:0% +one Orbit + + + align:start position:0% +one Orbit +later so under the gun raises small + + align:start position:0% +later so under the gun raises small + + + align:start position:0% +later so under the gun raises small +blind who is very very short who only + + align:start position:0% +blind who is very very short who only + + + align:start position:0% +blind who is very very short who only +has uh s and a half big blinds called + + align:start position:0% +has uh s and a half big blinds called + + + align:start position:0% +has uh s and a half big blinds called +calls and we decide to call with our + + align:start position:0% +calls and we decide to call with our + + + align:start position:0% +calls and we decide to call with our +seven with our six and a half to one + + align:start position:0% +seven with our six and a half to one + + + align:start position:0% +seven with our six and a half to one +odds + + align:start position:0% +odds + + + align:start position:0% +odds +here or 6 to1 + + align:start position:0% +here or 6 to1 + + + align:start position:0% +here or 6 to1 +odds so we flop uh Queen Jack five so we + + align:start position:0% +odds so we flop uh Queen Jack five so we + + + align:start position:0% +odds so we flop uh Queen Jack five so we +have second pair with a backd door + + align:start position:0% +have second pair with a backd door + + + align:start position:0% +have second pair with a backd door +straight draw and a back door flush draw + + align:start position:0% +straight draw and a back door flush draw + + + align:start position:0% +straight draw and a back door flush draw +and the swamp line goes all in for 1054 + + align:start position:0% +and the swamp line goes all in for 1054 + + + align:start position:0% +and the swamp line goes all in for 1054 +into + + align:start position:0% +into + + + align:start position:0% +into +1380 so this is sort of I think a pretty + + align:start position:0% +1380 so this is sort of I think a pretty + + + align:start position:0% +1380 so this is sort of I think a pretty +close spot I think if I knew for sure + + align:start position:0% +close spot I think if I knew for sure + + + align:start position:0% +close spot I think if I knew for sure +that ardom 1977 didn't have a hand here + + align:start position:0% +that ardom 1977 didn't have a hand here + + + align:start position:0% +that ardom 1977 didn't have a hand here +I think calling is definitely fine we're + + align:start position:0% +I think calling is definitely fine we're + + + align:start position:0% +I think calling is definitely fine we're +given about 2.3 to one odds and I think + + align:start position:0% +given about 2.3 to one odds and I think + + + align:start position:0% +given about 2.3 to one odds and I think +second pair with these back door draws + + align:start position:0% +second pair with these back door draws + + + align:start position:0% +second pair with these back door draws +is more than good enough against his + + align:start position:0% +is more than good enough against his + + + align:start position:0% +is more than good enough against his +range but um because I think his range + + align:start position:0% +range but um because I think his range + + + align:start position:0% +range but um because I think his range +will mostly be draws and top Pairs and + + align:start position:0% +will mostly be draws and top Pairs and + + + align:start position:0% +will mostly be draws and top Pairs and +second pairs probably not bottom pair + + align:start position:0% +second pairs probably not bottom pair + + + align:start position:0% +second pairs probably not bottom pair +that often because they did call Pre + + align:start position:0% +that often because they did call Pre + + + align:start position:0% +that often because they did call Pre +flop from the small blind which I don't + + align:start position:0% +flop from the small blind which I don't + + + align:start position:0% +flop from the small blind which I don't +expect most players would do with a hand + + align:start position:0% +expect most players would do with a hand + + + align:start position:0% +expect most players would do with a hand +like 75 suited so you know we're not + + align:start position:0% +like 75 suited so you know we're not + + + align:start position:0% +like 75 suited so you know we're not +even that happy to call him to be honest + + align:start position:0% +even that happy to call him to be honest + + + align:start position:0% +even that happy to call him to be honest +but I probably would call um but the + + align:start position:0% +but I probably would call um but the + + + align:start position:0% +but I probably would call um but the +fact that this guy here is behind and + + align:start position:0% +fact that this guy here is behind and + + + align:start position:0% +fact that this guy here is behind and +they could raise or they could call and + + align:start position:0% +they could raise or they could call and + + + align:start position:0% +they could raise or they could call and +we have to make more decisions on future + + align:start position:0% +we have to make more decisions on future + + + align:start position:0% +we have to make more decisions on future +streets I think really hurts us and I + + align:start position:0% +streets I think really hurts us and I + + + align:start position:0% +streets I think really hurts us and I +think we should have + + align:start position:0% +think we should have + + + align:start position:0% +think we should have +folded uh at the time I I decided to + + align:start position:0% +folded uh at the time I I decided to + + + align:start position:0% +folded uh at the time I I decided to +call so I I don't know why but I don't + + align:start position:0% +call so I I don't know why but I don't + + + align:start position:0% +call so I I don't know why but I don't +think this is a good play I think it's + + align:start position:0% +think this is a good play I think it's + + + align:start position:0% +think this is a good play I think it's +it's just too risky essentially you know + + align:start position:0% +it's just too risky essentially you know + + + align:start position:0% +it's just too risky essentially you know +it'll work most of the time and we and + + align:start position:0% +it'll work most of the time and we and + + + align:start position:0% +it'll work most of the time and we and +because most of the time Aram will fold + + align:start position:0% +because most of the time Aram will fold + + + align:start position:0% +because most of the time Aram will fold +because they're going to see two players + + align:start position:0% +because they're going to see two players + + + align:start position:0% +because they're going to see two players +putting money in but the times where + + align:start position:0% +putting money in but the times where + + + align:start position:0% +putting money in but the times where +they have something I'm going to have to + + align:start position:0% +they have something I'm going to have to + + + align:start position:0% +they have something I'm going to have to +fold and it's going to suck so so we do + + align:start position:0% +fold and it's going to suck so so we do + + + align:start position:0% +fold and it's going to suck so so we do +call um they actually had the same hand + + align:start position:0% +call um they actually had the same hand + + + align:start position:0% +call um they actually had the same hand +at us so it it worked out well I guess + + align:start position:0% +at us so it it worked out well I guess + + + align:start position:0% +at us so it it worked out well I guess +we sort of took a bad beat cuz we could + + align:start position:0% +we sort of took a bad beat cuz we could + + + align:start position:0% +we sort of took a bad beat cuz we could +have made a flush and they couldn't have + + align:start position:0% +have made a flush and they couldn't have + + + align:start position:0% +have made a flush and they couldn't have +so we were technically ahead but we get + + align:start position:0% +so we were technically ahead but we get + + + align:start position:0% +so we were technically ahead but we get +half to yeah + + align:start position:0% + + + + align:start position:0% + +um so yeah so I I'm not going through my + + align:start position:0% +um so yeah so I I'm not going through my + + + align:start position:0% +um so yeah so I I'm not going through my +tournament history from uh from maybe + + align:start position:0% +tournament history from uh from maybe + + + align:start position:0% +tournament history from uh from maybe +one month ago and saying I played every + + align:start position:0% +one month ago and saying I played every + + + align:start position:0% +one month ago and saying I played every +hand perfectly when I look through here + + align:start position:0% +hand perfectly when I look through here + + + align:start position:0% +hand perfectly when I look through here +I definitely there's a lot of there's a + + align:start position:0% +I definitely there's a lot of there's a + + + align:start position:0% +I definitely there's a lot of there's a +lot of mistakes there's a lot of hands I + + align:start position:0% +lot of mistakes there's a lot of hands I + + + align:start position:0% +lot of mistakes there's a lot of hands I +wish I could replay + + align:start position:0% +wish I could replay + + + align:start position:0% +wish I could replay +um so okay so this hand I guess is + + align:start position:0% +um so okay so this hand I guess is + + + align:start position:0% +um so okay so this hand I guess is +fairly simple so we have Ace King and I + + align:start position:0% +fairly simple so we have Ace King and I + + + align:start position:0% +fairly simple so we have Ace King and I +think it's definitely good enough to get + + align:start position:0% +think it's definitely good enough to get + + + align:start position:0% +think it's definitely good enough to get +it all in here with so as far as what my + + align:start position:0% +it all in here with so as far as what my + + + align:start position:0% +it all in here with so as far as what my +range is I + + align:start position:0% +range is I + + + align:start position:0% +range is I +think I think um sorry oh did you have + + align:start position:0% +think I think um sorry oh did you have + + + align:start position:0% +think I think um sorry oh did you have +suggestion on oh no no I I just saw this + + align:start position:0% +suggestion on oh no no I I just saw this + + + align:start position:0% +suggestion on oh no no I I just saw this +guy's uh handle and was + + align:start position:0% +guy's uh handle and was + + + align:start position:0% +guy's uh handle and was +I thought it was + + align:start position:0% + + + + align:start position:0% + +funny um okay sorry you thought it was + + align:start position:0% +funny um okay sorry you thought it was + + + align:start position:0% +funny um okay sorry you thought it was +Who funny + + align:start position:0% +Who funny + + + align:start position:0% +Who funny +oh sorry s funny + + align:start position:0% +oh sorry s funny + + + align:start position:0% +oh sorry s funny +okay no yeah don't ask me what my handle + + align:start position:0% +okay no yeah don't ask me what my handle + + + align:start position:0% +okay no yeah don't ask me what my handle +means my handle is what does it + + align:start position:0% +means my handle is what does it + + + align:start position:0% +means my handle is what does it +mean I I can't even read it um okay + + align:start position:0% +mean I I can't even read it um okay + + + align:start position:0% +mean I I can't even read it um okay +so I think it stood for something I + + align:start position:0% +so I think it stood for something I + + + align:start position:0% +so I think it stood for something I +probably made it when I was like 17 and + + align:start position:0% +probably made it when I was like 17 and + + + align:start position:0% +probably made it when I was like 17 and +I think get stood for something and I I + + align:start position:0% +I think get stood for something and I I + + + align:start position:0% +I think get stood for something and I I +might I probably don't remember what it + + align:start position:0% +might I probably don't remember what it + + + align:start position:0% +might I probably don't remember what it +says Okay um so okay so we go all in + + align:start position:0% +says Okay um so okay so we go all in + + + align:start position:0% +says Okay um so okay so we go all in +here um so this is sort of a no-brainer + + align:start position:0% +here um so this is sort of a no-brainer + + + align:start position:0% +here um so this is sort of a no-brainer +hand but let's stop and think a bit + + align:start position:0% +hand but let's stop and think a bit + + + align:start position:0% +hand but let's stop and think a bit +about what our range should be so I + + align:start position:0% +about what our range should be so I + + + align:start position:0% +about what our range should be so I +think with Ace King Ace King in Pocket + + align:start position:0% +think with Ace King Ace King in Pocket + + + align:start position:0% +think with Ace King Ace King in Pocket +TS I think it's fairly easy to get it + + align:start position:0% +TS I think it's fairly easy to get it + + + align:start position:0% +TS I think it's fairly easy to get it +all in I think with Ace Queen suited I + + align:start position:0% +all in I think with Ace Queen suited I + + + align:start position:0% +all in I think with Ace Queen suited I +would get it in um I think if I had Ace + + align:start position:0% +would get it in um I think if I had Ace + + + align:start position:0% +would get it in um I think if I had Ace +queen off suit I would probably fold + + align:start position:0% +queen off suit I would probably fold + + + align:start position:0% +queen off suit I would probably fold +although um with Ace Queen suited + + align:start position:0% +although um with Ace Queen suited + + + align:start position:0% +although um with Ace Queen suited +actually if this jet ski fun guy had as + + align:start position:0% +actually if this jet ski fun guy had as + + + align:start position:0% +actually if this jet ski fun guy had as +many chips as us then maybe I would have + + align:start position:0% +many chips as us then maybe I would have + + + align:start position:0% +many chips as us then maybe I would have +folded but the fact that we're actually + + align:start position:0% +folded but the fact that we're actually + + + align:start position:0% +folded but the fact that we're actually +not risking our entire 6 6250 against + + align:start position:0% +not risking our entire 6 6250 against + + + align:start position:0% +not risking our entire 6 6250 against +the two players who are in the pot is + + align:start position:0% +the two players who are in the pot is + + + align:start position:0% +the two players who are in the pot is +very relevant cuz I mean ardam covers us + + align:start position:0% +very relevant cuz I mean ardam covers us + + + align:start position:0% +very relevant cuz I mean ardam covers us +and they could in theory pick up pocket + + align:start position:0% +and they could in theory pick up pocket + + + align:start position:0% +and they could in theory pick up pocket +aces but it's much less likely for them + + align:start position:0% +aces but it's much less likely for them + + + align:start position:0% +aces but it's much less likely for them +to pick up pocket aces than this jet ski + + align:start position:0% +to pick up pocket aces than this jet ski + + + align:start position:0% +to pick up pocket aces than this jet ski +fun guy who's already in the pot so the + + align:start position:0% +fun guy who's already in the pot so the + + + align:start position:0% +fun guy who's already in the pot so the +fact that they only have less than 20 + + align:start position:0% +fact that they only have less than 20 + + + align:start position:0% +fact that they only have less than 20 +big blindes as well helps our case a lot + + align:start position:0% +big blindes as well helps our case a lot + + + align:start position:0% +big blindes as well helps our case a lot +so I would probably get it in with Ace + + align:start position:0% +so I would probably get it in with Ace + + + align:start position:0% +so I would probably get it in with Ace +Queen suited plus and then pocket pocket + + align:start position:0% +Queen suited plus and then pocket pocket + + + align:start position:0% +Queen suited plus and then pocket pocket +nines plus probably is what I'd get it + + align:start position:0% +nines plus probably is what I'd get it + + + align:start position:0% +nines plus probably is what I'd get it +in with here um so we go all in and we + + align:start position:0% +in with here um so we go all in and we + + + align:start position:0% +in with here um so we go all in and we +beat ace Jack which + + align:start position:0% +beat ace Jack which + + + align:start position:0% +beat ace Jack which +is which is good yeah so I think Ace + + align:start position:0% +is which is good yeah so I think Ace + + + align:start position:0% +is which is good yeah so I think Ace +Jack is slightly on the loose side I + + align:start position:0% +Jack is slightly on the loose side I + + + align:start position:0% +Jack is slightly on the loose side I +mean I think it's a fine play definitely + + align:start position:0% +mean I think it's a fine play definitely + + + align:start position:0% +mean I think it's a fine play definitely +to get it all in with Ace Jack but maybe + + align:start position:0% +to get it all in with Ace Jack but maybe + + + align:start position:0% +to get it all in with Ace Jack but maybe +they could have may like they because + + align:start position:0% +they could have may like they because + + + align:start position:0% +they could have may like they because +they do have more than 20 big blinds + + align:start position:0% +they do have more than 20 big blinds + + + align:start position:0% +they do have more than 20 big blinds +here so I think maybe they could have + + align:start position:0% +here so I think maybe they could have + + + align:start position:0% +here so I think maybe they could have +considered calling or raising small and + + align:start position:0% +considered calling or raising small and + + + align:start position:0% +considered calling or raising small and +folding if someone like us entered the + + align:start position:0% +folding if someone like us entered the + + + align:start position:0% +folding if someone like us entered the +pot but nonetheless I think they played + + align:start position:0% +pot but nonetheless I think they played + + + align:start position:0% +pot but nonetheless I think they played +their hand + + align:start position:0% + + + + align:start position:0% + +fine okay so the next thing we have + + align:start position:0% +fine okay so the next thing we have + + + align:start position:0% +fine okay so the next thing we have +pocket nines so many this guy raises we + + align:start position:0% +pocket nines so many this guy raises we + + + align:start position:0% +pocket nines so many this guy raises we +call so we're getting deeper now because + + align:start position:0% +call so we're getting deeper now because + + + align:start position:0% +call so we're getting deeper now because +we won the last hand so now we' got + + align:start position:0% +we won the last hand so now we' got + + + align:start position:0% +we won the last hand so now we' got +we've got 40 big blinds and we call this + + align:start position:0% +we've got 40 big blinds and we call this + + + align:start position:0% +we've got 40 big blinds and we call this +guy also calls and Liam kid goes all in + + align:start position:0% +guy also calls and Liam kid goes all in + + + align:start position:0% +guy also calls and Liam kid goes all in +for 30 big blinds and so they get out of + + align:start position:0% +for 30 big blinds and so they get out of + + + align:start position:0% +for 30 big blinds and so they get out of +the way I think this is actually a very + + align:start position:0% +the way I think this is actually a very + + + align:start position:0% +the way I think this is actually a very +close spot so um I do think one big uh + + align:start position:0% +close spot so um I do think one big uh + + + align:start position:0% +close spot so um I do think one big uh +incentive to get it all in is I think + + align:start position:0% +incentive to get it all in is I think + + + align:start position:0% +incentive to get it all in is I think +it's not that likely that Liam kid has + + align:start position:0% +it's not that likely that Liam kid has + + + align:start position:0% +it's not that likely that Liam kid has +like pocket kings or pocket aces because + + align:start position:0% +like pocket kings or pocket aces because + + + align:start position:0% +like pocket kings or pocket aces because +I think there's a good chance they would + + align:start position:0% +I think there's a good chance they would + + + align:start position:0% +I think there's a good chance they would +have just raised smaller maybe to try to + + align:start position:0% +have just raised smaller maybe to try to + + + align:start position:0% +have just raised smaller maybe to try to +sctor people in so I actually think I'm + + align:start position:0% +sctor people in so I actually think I'm + + + align:start position:0% +sctor people in so I actually think I'm +not losing to too muchu and same with + + align:start position:0% +not losing to too muchu and same with + + + align:start position:0% +not losing to too muchu and same with +ardam I think it's also very hard for + + align:start position:0% +ardam I think it's also very hard for + + + align:start position:0% +ardam I think it's also very hard for +ardam to have a good hand so even though + + align:start position:0% +ardam to have a good hand so even though + + + align:start position:0% +ardam to have a good hand so even though +in the first example we talked about how + + align:start position:0% +in the first example we talked about how + + + align:start position:0% +in the first example we talked about how +um sometimes you know calling with + + align:start position:0% +um sometimes you know calling with + + + align:start position:0% +um sometimes you know calling with +pocket Aces here is a good play but you + + align:start position:0% +pocket Aces here is a good play but you + + + align:start position:0% +pocket Aces here is a good play but you +know I said if one guy raised and you're + + align:start position:0% +know I said if one guy raised and you're + + + align:start position:0% +know I said if one guy raised and you're +the second guy you should maybe call + + align:start position:0% +the second guy you should maybe call + + + align:start position:0% +the second guy you should maybe call +with pocket aces like 20% of the time + + align:start position:0% +with pocket aces like 20% of the time + + + align:start position:0% +with pocket aces like 20% of the time +when it's two guys who have like when + + align:start position:0% +when it's two guys who have like when + + + align:start position:0% +when it's two guys who have like when +it's one guy who has raised me who has + + align:start position:0% +it's one guy who has raised me who has + + + align:start position:0% +it's one guy who has raised me who has +called and now you're deciding what to + + align:start position:0% +called and now you're deciding what to + + + align:start position:0% +called and now you're deciding what to +do with pocket aces you know instead of + + align:start position:0% +do with pocket aces you know instead of + + + align:start position:0% +do with pocket aces you know instead of +20% you should be calling it's literally + + align:start position:0% +20% you should be calling it's literally + + + align:start position:0% +20% you should be calling it's literally +like you know maybe like 2% or 1% you + + align:start position:0% +like you know maybe like 2% or 1% you + + + align:start position:0% +like you know maybe like 2% or 1% you +should be calling with pocket aces so + + align:start position:0% +should be calling with pocket aces so + + + align:start position:0% +should be calling with pocket aces so +you know if you combine multiply 1% by + + align:start position:0% +you know if you combine multiply 1% by + + + align:start position:0% +you know if you combine multiply 1% by +the probability of getting dealt pocket + + align:start position:0% +the probability of getting dealt pocket + + + align:start position:0% +the probability of getting dealt pocket +aces which is around like 1 and 200 + + align:start position:0% +aces which is around like 1 and 200 + + + align:start position:0% +aces which is around like 1 and 200 +it's literally like one out of 20,000 + + align:start position:0% +it's literally like one out of 20,000 + + + align:start position:0% +it's literally like one out of 20,000 +that PS pocket aces here so um so I'm + + align:start position:0% +that PS pocket aces here so um so I'm + + + align:start position:0% +that PS pocket aces here so um so I'm +not too afraid of him so I I really + + align:start position:0% +not too afraid of him so I I really + + + align:start position:0% +not too afraid of him so I I really +think getting it in is fine but at the + + align:start position:0% +think getting it in is fine but at the + + + align:start position:0% +think getting it in is fine but at the +same time you know I don't think I'm + + align:start position:0% +same time you know I don't think I'm + + + align:start position:0% +same time you know I don't think I'm +ever a favorite here I think their range + + align:start position:0% +ever a favorite here I think their range + + + align:start position:0% +ever a favorite here I think their range +is essentially like Ace King Ace Queen + + align:start position:0% +is essentially like Ace King Ace Queen + + + align:start position:0% +is essentially like Ace King Ace Queen +maybe Ace Jack suited and then + + align:start position:0% +maybe Ace Jack suited and then + + + align:start position:0% +maybe Ace Jack suited and then +essentially pocket 10s pocket NES pocket + + align:start position:0% +essentially pocket 10s pocket NES pocket + + + align:start position:0% +essentially pocket 10s pocket NES pocket +Jacks pocket Queens maybe occasionally + + align:start position:0% +Jacks pocket Queens maybe occasionally + + + align:start position:0% +Jacks pocket Queens maybe occasionally +pocket eights so I could have done an + + align:start position:0% +pocket eights so I could have done an + + + align:start position:0% +pocket eights so I could have done an +exact Equity calculation on poker stove + + align:start position:0% +exact Equity calculation on poker stove + + + align:start position:0% +exact Equity calculation on poker stove +and if I did it probably would have been + + align:start position:0% +and if I did it probably would have been + + + align:start position:0% +and if I did it probably would have been +very very close but I decided to fold + + align:start position:0% +very very close but I decided to fold + + + align:start position:0% +very very close but I decided to fold +and they take down the + + align:start position:0% + + + + align:start position:0% + +P okay so the next hand we get Ace Jack + + align:start position:0% +P okay so the next hand we get Ace Jack + + + align:start position:0% +P okay so the next hand we get Ace Jack +we raise red the gun this uh this guy go + + align:start position:0% +we raise red the gun this uh this guy go + + + align:start position:0% +we raise red the gun this uh this guy go +this guy goes on in for six big blinds + + align:start position:0% +this guy goes on in for six big blinds + + + align:start position:0% +this guy goes on in for six big blinds +we're basically committed here even if + + align:start position:0% +we're basically committed here even if + + + align:start position:0% +we're basically committed here even if +we think he's crushing us so I call and + + align:start position:0% +we think he's crushing us so I call and + + + align:start position:0% +we think he's crushing us so I call and +we lose the Ace King not really too much + + align:start position:0% +we lose the Ace King not really too much + + + align:start position:0% +we lose the Ace King not really too much +we can do here um although this does + + align:start position:0% +we can do here um although this does + + + align:start position:0% +we can do here um although this does +illustrate one concept which is when + + align:start position:0% +illustrate one concept which is when + + + align:start position:0% +illustrate one concept which is when +there are Stacks behind like zarban who + + align:start position:0% +there are Stacks behind like zarban who + + + align:start position:0% +there are Stacks behind like zarban who +are short enough that they can commit + + align:start position:0% +are short enough that they can commit + + + align:start position:0% +are short enough that they can commit +You by going all in you should be + + align:start position:0% +You by going all in you should be + + + align:start position:0% +You by going all in you should be +slightly less incentivized to open + + align:start position:0% +slightly less incentivized to open + + + align:start position:0% +slightly less incentivized to open +speculative hands here like say I had + + align:start position:0% +speculative hands here like say I had + + + align:start position:0% +speculative hands here like say I had +109 suited I think while normally I + + align:start position:0% +109 suited I think while normally I + + + align:start position:0% +109 suited I think while normally I +would consider opening 109 suited here + + align:start position:0% +would consider opening 109 suited here + + + align:start position:0% +would consider opening 109 suited here +as a steal it's a huge disincentive to + + align:start position:0% +as a steal it's a huge disincentive to + + + align:start position:0% +as a steal it's a huge disincentive to +steal here with 10 n suited when someone + + align:start position:0% +steal here with 10 n suited when someone + + + align:start position:0% +steal here with 10 n suited when someone +like zarazan can just pick up you know + + align:start position:0% +like zarazan can just pick up you know + + + align:start position:0% +like zarazan can just pick up you know +even a hand as weak as like Ace Jack + + align:start position:0% +even a hand as weak as like Ace Jack + + + align:start position:0% +even a hand as weak as like Ace Jack +suited and or Ace jack off suit and go + + align:start position:0% +suited and or Ace jack off suit and go + + + align:start position:0% +suited and or Ace jack off suit and go +all in and beat our 109 suited so + + align:start position:0% +all in and beat our 109 suited so + + + align:start position:0% +all in and beat our 109 suited so +um but I mean Ace Jack is more than good + + align:start position:0% +um but I mean Ace Jack is more than good + + + align:start position:0% +um but I mean Ace Jack is more than good +enough to still raise here and we + + align:start position:0% +enough to still raise here and we + + + align:start position:0% +enough to still raise here and we +unfortunately run into Ace + + align:start position:0% + + + + align:start position:0% + +King okay so the next end we get e Jack + + align:start position:0% +King okay so the next end we get e Jack + + + align:start position:0% +King okay so the next end we get e Jack +again and uh the same guy who just + + align:start position:0% +again and uh the same guy who just + + + align:start position:0% +again and uh the same guy who just +doubled up through US goes all in and + + align:start position:0% +doubled up through US goes all in and + + + align:start position:0% +doubled up through US goes all in and +here I call him because here the even + + align:start position:0% +here I call him because here the even + + + align:start position:0% +here I call him because here the even +though there's more chips the positions + + align:start position:0% +though there's more chips the positions + + + align:start position:0% +though there's more chips the positions +are a lot later and specifically uh they + + align:start position:0% +are a lot later and specifically uh they + + + align:start position:0% +are a lot later and specifically uh they +went all in for 14 big blinds when no + + align:start position:0% +went all in for 14 big blinds when no + + + align:start position:0% +went all in for 14 big blinds when no +one else was in the pot so their range + + align:start position:0% +one else was in the pot so their range + + + align:start position:0% +one else was in the pot so their range +is you know their range isn't super + + align:start position:0% +is you know their range isn't super + + + align:start position:0% +is you know their range isn't super +duper wide but it's definitely wide + + align:start position:0% +duper wide but it's definitely wide + + + align:start position:0% +duper wide but it's definitely wide +enough that Ace Jack I'm happy to call + + align:start position:0% +enough that Ace Jack I'm happy to call + + + align:start position:0% +enough that Ace Jack I'm happy to call +here as far as what my range is I think + + align:start position:0% +here as far as what my range is I think + + + align:start position:0% +here as far as what my range is I think +um I think I wouldn't call with Ace 10 + + align:start position:0% +um I think I wouldn't call with Ace 10 + + + align:start position:0% +um I think I wouldn't call with Ace 10 +off suit but I would call with Ace 10 + + align:start position:0% +off suit but I would call with Ace 10 + + + align:start position:0% +off suit but I would call with Ace 10 +suited so probably Ace 10 suited and I + + align:start position:0% +suited so probably Ace 10 suited and I + + + align:start position:0% +suited so probably Ace 10 suited and I +think I'd call with king queen suited + + align:start position:0% +think I'd call with king queen suited + + + align:start position:0% +think I'd call with king queen suited +but not king queen off suit and the + + align:start position:0% +but not king queen off suit and the + + + align:start position:0% +but not king queen off suit and the +smallest pair I get it in with is + + align:start position:0% +smallest pair I get it in with is + + + align:start position:0% +smallest pair I get it in with is +probably pocket sixes I think um + + align:start position:0% +probably pocket sixes I think um + + + align:start position:0% +probably pocket sixes I think um +maybe pocket F + + align:start position:0% +maybe pocket F + + + align:start position:0% +maybe pocket F +okay yeah probably pocket FES is too + + align:start position:0% +okay yeah probably pocket FES is too + + + align:start position:0% +okay yeah probably pocket FES is too +loose yeah probably pocket + + align:start position:0% +loose yeah probably pocket + + + align:start position:0% +loose yeah probably pocket +sixes so we call so unfortunately we + + align:start position:0% +sixes so we call so unfortunately we + + + align:start position:0% +sixes so we call so unfortunately we +lose to King 10 suited so he doubles up + + align:start position:0% +lose to King 10 suited so he doubles up + + + align:start position:0% +lose to King 10 suited so he doubles up +through us again and we're kind of short + + align:start position:0% + + + + align:start position:0% + +now a question yeah on that last hand + + align:start position:0% +now a question yeah on that last hand + + + align:start position:0% +now a question yeah on that last hand +why go all in yourself why not just call + + align:start position:0% +why go all in yourself why not just call + + + align:start position:0% +why go all in yourself why not just call +is all in oh okay good question yeah so + + align:start position:0% +is all in oh okay good question yeah so + + + align:start position:0% +is all in oh okay good question yeah so +yeah this is a good question so in this + + align:start position:0% +yeah this is a good question so in this + + + align:start position:0% +yeah this is a good question so in this +case the two plays I'd say are are + + align:start position:0% +case the two plays I'd say are are + + + align:start position:0% +case the two plays I'd say are are +fairly close to equiv um because okay so + + align:start position:0% +fairly close to equiv um because okay so + + + align:start position:0% +fairly close to equiv um because okay so +what's the difference right they they're + + align:start position:0% +what's the difference right they they're + + + align:start position:0% +what's the difference right they they're +going to be the same most of almost + + align:start position:0% +going to be the same most of almost + + + align:start position:0% +going to be the same most of almost +always because check raise is just going + + align:start position:0% +always because check raise is just going + + + align:start position:0% +always because check raise is just going +to fold yeah um but uh right but okay so + + align:start position:0% +to fold yeah um but uh right but okay so + + + align:start position:0% +to fold yeah um but uh right but okay so +what's the difference the difference is + + align:start position:0% +what's the difference the difference is + + + align:start position:0% +what's the difference the difference is +if we don't go all in then check Rays if + + align:start position:0% +if we don't go all in then check Rays if + + + align:start position:0% +if we don't go all in then check Rays if +let's say he picks up Aces right then he + + align:start position:0% +let's say he picks up Aces right then he + + + align:start position:0% +let's say he picks up Aces right then he +can just go all in and we're basically + + align:start position:0% +can just go all in and we're basically + + + align:start position:0% +can just go all in and we're basically +forced to call him cuz we can't if we if + + align:start position:0% +forced to call him cuz we can't if we if + + + align:start position:0% +forced to call him cuz we can't if we if +we put in four + + align:start position:0% +we put in four + + + align:start position:0% +we put in four +4,118 and they go all in we can't really + + align:start position:0% +4,118 and they go all in we can't really + + + align:start position:0% +4,118 and they go all in we can't really +fold for only 3,000 more we can't really + + align:start position:0% +fold for only 3,000 more we can't really + + + align:start position:0% +fold for only 3,000 more we can't really +fold pre flop with 41 odds would that + + align:start position:0% +fold pre flop with 41 odds would that + + + align:start position:0% +fold pre flop with 41 odds would that +change if you were the big stack if like + + align:start position:0% +change if you were the big stack if like + + + align:start position:0% +change if you were the big stack if like +you had check ra a stack and he had your + + align:start position:0% +you had check ra a stack and he had your + + + align:start position:0% +you had check ra a stack and he had your +stack oh yeah for sure yeah yeah that's + + align:start position:0% +stack oh yeah for sure yeah yeah that's + + + align:start position:0% +stack oh yeah for sure yeah yeah that's +a very good point yeah yeah for sure so + + align:start position:0% +a very good point yeah yeah for sure so + + + align:start position:0% +a very good point yeah yeah for sure so +if we had the same stack as check ra + + align:start position:0% +if we had the same stack as check ra + + + align:start position:0% +if we had the same stack as check ra +here I would just call and then if check + + align:start position:0% +here I would just call and then if check + + + align:start position:0% +here I would just call and then if check +raise goes all in I would probably fold + + align:start position:0% +raise goes all in I would probably fold + + + align:start position:0% +raise goes all in I would probably fold +okay but I I mean I'm also going to call + + align:start position:0% +okay but I I mean I'm also going to call + + + align:start position:0% +okay but I I mean I'm also going to call +here with pocket aces so they can't just + + align:start position:0% +here with pocket aces so they can't just + + + align:start position:0% +here with pocket aces so they can't just +look down at pocket twos and go all in + + align:start position:0% +look down at pocket twos and go all in + + + align:start position:0% +look down at pocket twos and go all in +and Bully me around okay yeah so so my + + align:start position:0% +and Bully me around okay yeah so so my + + + align:start position:0% +and Bully me around okay yeah so so my +strategy if we had their stack would be + + align:start position:0% +strategy if we had their stack would be + + + align:start position:0% +strategy if we had their stack would be +to um would be to call my entire range + + align:start position:0% +to um would be to call my entire range + + + align:start position:0% +to um would be to call my entire range +that I plan on playing but in this case + + align:start position:0% +that I plan on playing but in this case + + + align:start position:0% +that I plan on playing but in this case +the only thing calling does is it gives + + align:start position:0% +the only thing calling does is it gives + + + align:start position:0% +the only thing calling does is it gives +him more options like let's say they had + + align:start position:0% +him more options like let's say they had + + + align:start position:0% +him more options like let's say they had +a very marginal situation like let's say + + align:start position:0% +a very marginal situation like let's say + + + align:start position:0% +a very marginal situation like let's say +they had king queen suited I think if I + + align:start position:0% +they had king queen suited I think if I + + + align:start position:0% +they had king queen suited I think if I +if I only called they could maybe argue + + align:start position:0% +if I only called they could maybe argue + + + align:start position:0% +if I only called they could maybe argue +for callings with king queen suited and + + align:start position:0% +for callings with king queen suited and + + + align:start position:0% +for callings with king queen suited and +seeing a flop whereas if I go all in I + + align:start position:0% +seeing a flop whereas if I go all in I + + + align:start position:0% +seeing a flop whereas if I go all in I +think they're forced to fold king queen + + align:start position:0% +think they're forced to fold king queen + + + align:start position:0% +think they're forced to fold king queen +basically a better chance of making him + + align:start position:0% +basically a better chance of making him + + + align:start position:0% +basically a better chance of making him +exactly yeah I'm just giving him fewer + + align:start position:0% +exactly yeah I'm just giving him fewer + + + align:start position:0% +exactly yeah I'm just giving him fewer +options but it's very very marginal like + + align:start position:0% +options but it's very very marginal like + + + align:start position:0% +options but it's very very marginal like +it affects it affects it basically + + align:start position:0% +it affects it affects it basically + + + align:start position:0% +it affects it affects it basically +specifically for maybe king queen suited + + align:start position:0% +specifically for maybe king queen suited + + + align:start position:0% +specifically for maybe king queen suited +like it affects basically for one hand + + align:start position:0% +like it affects basically for one hand + + + align:start position:0% +like it affects basically for one hand +or I don't know maybe like two or three + + align:start position:0% +or I don't know maybe like two or three + + + align:start position:0% +or I don't know maybe like two or three +hands but yeah it's very rare but um but + + align:start position:0% +hands but yeah it's very rare but um but + + + align:start position:0% +hands but yeah it's very rare but um but +you might as well minimize the options + + align:start position:0% +you might as well minimize the options + + + align:start position:0% +you might as well minimize the options +you give your opponent + + align:start position:0% +you give your opponent + + + align:start position:0% +you give your opponent +so yeah like I'd say the the minimum + + align:start position:0% +so yeah like I'd say the the minimum + + + align:start position:0% +so yeah like I'd say the the minimum +stack size I would need before I call + + align:start position:0% +stack size I would need before I call + + + align:start position:0% +stack size I would need before I call +instead of go all in with is maybe um I + + align:start position:0% +instead of go all in with is maybe um I + + + align:start position:0% +instead of go all in with is maybe um I +think maybe like 13,000 yeah I think at + + align:start position:0% +think maybe like 13,000 yeah I think at + + + align:start position:0% +think maybe like 13,000 yeah I think at +13,000 it's sort of more than I I'd want + + align:start position:0% +13,000 it's sort of more than I I'd want + + + align:start position:0% +13,000 it's sort of more than I I'd want +to risk against this + + align:start position:0% + + + + align:start position:0% + +yeah okay so now we're kind of short so + + align:start position:0% +yeah okay so now we're kind of short so + + + align:start position:0% +yeah okay so now we're kind of short so +we blind down for a bit we don't get + + align:start position:0% +we blind down for a bit we don't get + + + align:start position:0% +we blind down for a bit we don't get +cards and when you don't get cards in a + + align:start position:0% +cards and when you don't get cards in a + + + align:start position:0% +cards and when you don't get cards in a +tournament there's not really much you + + align:start position:0% +tournament there's not really much you + + + align:start position:0% +tournament there's not really much you +can do other than blind down not like go + + align:start position:0% +can do other than blind down not like go + + + align:start position:0% +can do other than blind down not like go +all in with crap and just lose so we + + align:start position:0% +all in with crap and just lose so we + + + align:start position:0% +all in with crap and just lose so we +blind down for a bit but we're fortunate + + align:start position:0% +blind down for a bit but we're fortunate + + + align:start position:0% +blind down for a bit but we're fortunate +to pick up Kings so this is sort of a + + align:start position:0% +to pick up Kings so this is sort of a + + + align:start position:0% +to pick up Kings so this is sort of a +no-brainer we go all in there's no point + + align:start position:0% +no-brainer we go all in there's no point + + + align:start position:0% +no-brainer we go all in there's no point +trapping because they're guaranteed to + + align:start position:0% +trapping because they're guaranteed to + + + align:start position:0% +trapping because they're guaranteed to +call us and we get called by E5 and we + + align:start position:0% +call us and we get called by E5 and we + + + align:start position:0% +call us and we get called by E5 and we +win which is good + + align:start position:0% +win which is good + + + align:start position:0% +win which is good +um okay + + align:start position:0% +um okay + + + align:start position:0% +um okay +so the next hand we get 87 offit and + + align:start position:0% +so the next hand we get 87 offit and + + + align:start position:0% +so the next hand we get 87 offit and +against the button raids I think calling + + align:start position:0% +against the button raids I think calling + + + align:start position:0% +against the button raids I think calling +is fine I think their range is just + + align:start position:0% +is fine I think their range is just + + + align:start position:0% +is fine I think their range is just +going to be wide enough where even + + align:start position:0% +going to be wide enough where even + + + align:start position:0% +going to be wide enough where even +though the reverse implied odds once + + align:start position:0% +though the reverse implied odds once + + + align:start position:0% +though the reverse implied odds once +again really don't work in our favor we + + align:start position:0% +again really don't work in our favor we + + + align:start position:0% +again really don't work in our favor we +just have to sort of realize the equity + + align:start position:0% +just have to sort of realize the equity + + + align:start position:0% +just have to sort of realize the equity +from four and a half to one odds so I'm + + align:start position:0% +from four and a half to one odds so I'm + + + align:start position:0% +from four and a half to one odds so I'm +going to + + align:start position:0% +going to + + + align:start position:0% +going to +call and so we flop nothing I'm planning + + align:start position:0% +call and so we flop nothing I'm planning + + + align:start position:0% +call and so we flop nothing I'm planning +to just check fold so I check they check + + align:start position:0% +to just check fold so I check they check + + + align:start position:0% +to just check fold so I check they check +back turn as a four once again we have + + align:start position:0% +back turn as a four once again we have + + + align:start position:0% +back turn as a four once again we have +nothing I could Bluff here but I figure + + align:start position:0% +nothing I could Bluff here but I figure + + + align:start position:0% +nothing I could Bluff here but I figure +you know I'm not really looking to make + + align:start position:0% +you know I'm not really looking to make + + + align:start position:0% +you know I'm not really looking to make +a big Bluff with this hand cuz I have no + + align:start position:0% +a big Bluff with this hand cuz I have no + + + align:start position:0% +a big Bluff with this hand cuz I have no +draw no pair there's no point um but I + + align:start position:0% +draw no pair there's no point um but I + + + align:start position:0% +draw no pair there's no point um but I +will probably look to make a bluff on + + align:start position:0% +will probably look to make a bluff on + + + align:start position:0% +will probably look to make a bluff on +the river if they also check just + + align:start position:0% +the river if they also check just + + + align:start position:0% +the river if they also check just +because whenever you have like no chance + + align:start position:0% +because whenever you have like no chance + + + align:start position:0% +because whenever you have like no chance +of winning the pot then and it's the + + align:start position:0% +of winning the pot then and it's the + + + align:start position:0% +of winning the pot then and it's the +river then making a bluff is not + + align:start position:0% +river then making a bluff is not + + + align:start position:0% +river then making a bluff is not +unreasonable but in this case bluffing + + align:start position:0% +unreasonable but in this case bluffing + + + align:start position:0% +unreasonable but in this case bluffing +is kind of bad because with any club + + align:start position:0% +is kind of bad because with any club + + + align:start position:0% +is kind of bad because with any club +they might just call me because any club + + align:start position:0% +they might just call me because any club + + + align:start position:0% +they might just call me because any club +is going to have some Equity + + align:start position:0% +is going to have some Equity + + + align:start position:0% +is going to have some Equity +so so I check they check back the r is a + + align:start position:0% +so so I check they check back the r is a + + + align:start position:0% +so so I check they check back the r is a +fourth club which is I think a pretty + + align:start position:0% +fourth club which is I think a pretty + + + align:start position:0% +fourth club which is I think a pretty +good card for me um because you know I + + align:start position:0% +good card for me um because you know I + + + align:start position:0% +good card for me um because you know I +can easily represent a small club and if + + align:start position:0% +can easily represent a small club and if + + + align:start position:0% +can easily represent a small club and if +I did have a small Club I am definitely + + align:start position:0% +I did have a small Club I am definitely + + + align:start position:0% +I did have a small Club I am definitely +value betting so you know it's a pretty + + align:start position:0% +value betting so you know it's a pretty + + + align:start position:0% +value betting so you know it's a pretty +good card for me to Bluff and they're + + align:start position:0% +good card for me to Bluff and they're + + + align:start position:0% +good card for me to Bluff and they're +probably going to have to fold King High + + align:start position:0% +probably going to have to fold King High + + + align:start position:0% +probably going to have to fold King High +so so I bet and I don't think I have to + + align:start position:0% +so so I bet and I don't think I have to + + + align:start position:0% +so so I bet and I don't think I have to +bet fairly big you know I I'm just + + align:start position:0% +bet fairly big you know I I'm just + + + align:start position:0% +bet fairly big you know I I'm just +looking for a size where they have to + + align:start position:0% +looking for a size where they have to + + + align:start position:0% +looking for a size where they have to +fold sometimes and they'll have to pay + + align:start position:0% +fold sometimes and they'll have to pay + + + align:start position:0% +fold sometimes and they'll have to pay +me off sometimes when I have to have a + + align:start position:0% +me off sometimes when I have to have a + + + align:start position:0% +me off sometimes when I have to have a +when I have a small club and so they + + align:start position:0% +when I have a small club and so they + + + align:start position:0% +when I have a small club and so they +raise me here which is which is pretty + + align:start position:0% +raise me here which is which is pretty + + + align:start position:0% +raise me here which is which is pretty +weird I don't really I still don't + + align:start position:0% +weird I don't really I still don't + + + align:start position:0% +weird I don't really I still don't +really have a good idea what I think he + + align:start position:0% +really have a good idea what I think he + + + align:start position:0% +really have a good idea what I think he +has um I mean I'm certain they have me + + align:start position:0% +has um I mean I'm certain they have me + + + align:start position:0% +has um I mean I'm certain they have me +beat you know so I I just folded like + + align:start position:0% +beat you know so I I just folded like + + + align:start position:0% +beat you know so I I just folded like +you know we could think a bit about + + align:start position:0% +you know we could think a bit about + + + align:start position:0% +you know we could think a bit about +doing something crazy like go all in but + + align:start position:0% +doing something crazy like go all in but + + + align:start position:0% +doing something crazy like go all in but +it would just be weird I I think it's + + align:start position:0% +it would just be weird I I think it's + + + align:start position:0% +it would just be weird I I think it's +unnecessary you know we've got nothing + + align:start position:0% +unnecessary you know we've got nothing + + + align:start position:0% +unnecessary you know we've got nothing +so I just folded yeah I don't really + + align:start position:0% +so I just folded yeah I don't really + + + align:start position:0% +so I just folded yeah I don't really +know maybe they just had like a slow + + align:start position:0% +know maybe they just had like a slow + + + align:start position:0% +know maybe they just had like a slow +played flush it's possible they have + + align:start position:0% +played flush it's possible they have + + + align:start position:0% +played flush it's possible they have +like a king High flush here and they + + align:start position:0% +like a king High flush here and they + + + align:start position:0% +like a king High flush here and they +slow played the Flop they decided to + + align:start position:0% +slow played the Flop they decided to + + + align:start position:0% +slow played the Flop they decided to +slow play the turn again because the + + align:start position:0% +slow play the turn again because the + + + align:start position:0% +slow play the turn again because the +turn sort of didn't hit anybody um yeah + + align:start position:0% +turn sort of didn't hit anybody um yeah + + + align:start position:0% +turn sort of didn't hit anybody um yeah +I'm not sure so i f here I mean it's + + align:start position:0% +I'm not sure so i f here I mean it's + + + align:start position:0% +I'm not sure so i f here I mean it's +possible they just had a high club but I + + align:start position:0% +possible they just had a high club but I + + + align:start position:0% +possible they just had a high club but I +feel like with a high club they should + + align:start position:0% +feel like with a high club they should + + + align:start position:0% +feel like with a high club they should +have bet at some point to sort of just + + align:start position:0% +have bet at some point to sort of just + + + align:start position:0% +have bet at some point to sort of just +because the a good flush straw is just + + align:start position:0% +because the a good flush straw is just + + + align:start position:0% +because the a good flush straw is just +has enough equity but nonetheless I + + align:start position:0% +has enough equity but nonetheless I + + + align:start position:0% +has enough equity but nonetheless I +guess we'll never know that's one + + align:start position:0% +guess we'll never know that's one + + + align:start position:0% +guess we'll never know that's one +benefit of calling you get to find out + + align:start position:0% +benefit of calling you get to find out + + + align:start position:0% +benefit of calling you get to find out +what your opponent had um okay so the + + align:start position:0% +what your opponent had um okay so the + + + align:start position:0% +what your opponent had um okay so the +next time we have Queen Jack we've got + + align:start position:0% +next time we have Queen Jack we've got + + + align:start position:0% +next time we have Queen Jack we've got +12 bets I just go all in 12 is around + + align:start position:0% +12 bets I just go all in 12 is around + + + align:start position:0% +12 bets I just go all in 12 is around +the cut off of right like I said 12 is + + align:start position:0% +the cut off of right like I said 12 is + + + align:start position:0% +the cut off of right like I said 12 is +sort of the cut off where if you have 12 + + align:start position:0% +sort of the cut off where if you have 12 + + + align:start position:0% +sort of the cut off where if you have 12 +bets or less instead of raising just go + + align:start position:0% +bets or less instead of raising just go + + + align:start position:0% +bets or less instead of raising just go +all in + + align:start position:0% +all in + + + align:start position:0% +all in +and that's what we do so we get called + + align:start position:0% +and that's what we do so we get called + + + align:start position:0% +and that's what we do so we get called +but so this is actually a pretty sick + + align:start position:0% +but so this is actually a pretty sick + + + align:start position:0% +but so this is actually a pretty sick +board yeah so they cled a full house but + + align:start position:0% +board yeah so they cled a full house but + + + align:start position:0% +board yeah so they cled a full house but +we rered a higher Full + + align:start position:0% +we rered a higher Full + + + align:start position:0% +we rered a higher Full +House it was yeah it's sort of a waste + + align:start position:0% +House it was yeah it's sort of a waste + + + align:start position:0% +House it was yeah it's sort of a waste +because you know normally if this + + align:start position:0% +because you know normally if this + + + align:start position:0% +because you know normally if this +happens you could win like a 100 big + + align:start position:0% +happens you could win like a 100 big + + + align:start position:0% +happens you could win like a 100 big +blinds from them probably but instead we + + align:start position:0% +blinds from them probably but instead we + + + align:start position:0% +blinds from them probably but instead we +only want how many uh eight big blinds + + align:start position:0% +only want how many uh eight big blinds + + + align:start position:0% +only want how many uh eight big blinds +so it's sort of a waste but whatever + + align:start position:0% + + + + align:start position:0% + +um okay so the next hand I got pocket + + align:start position:0% +um okay so the next hand I got pocket + + + align:start position:0% +um okay so the next hand I got pocket +fives and we raised to we raised to a + + align:start position:0% +fives and we raised to we raised to a + + + align:start position:0% +fives and we raised to we raised to a +thousand and Liam kid goes on again and + + align:start position:0% +thousand and Liam kid goes on again and + + + align:start position:0% +thousand and Liam kid goes on again and +you know it's irritating but I think + + align:start position:0% +you know it's irritating but I think + + + align:start position:0% +you know it's irritating but I think +once again I have to fold it's I think + + align:start position:0% +once again I have to fold it's I think + + + align:start position:0% +once again I have to fold it's I think +I'm just I don't have enough equity to + + align:start position:0% +I'm just I don't have enough equity to + + + align:start position:0% +I'm just I don't have enough equity to +call like given his range um once again + + align:start position:0% +call like given his range um once again + + + align:start position:0% +call like given his range um once again +it's a situation where it's a fairly big + + align:start position:0% +it's a situation where it's a fairly big + + + align:start position:0% +it's a situation where it's a fairly big +all- in so you know I could maybe not + + align:start position:0% +all- in so you know I could maybe not + + + align:start position:0% +all- in so you know I could maybe not +put them on Aces although given that + + align:start position:0% +put them on Aces although given that + + + align:start position:0% +put them on Aces although given that +they've done this once they're more + + align:start position:0% +they've done this once they're more + + + align:start position:0% +they've done this once they're more +likely to just do this with their entire + + align:start position:0% +likely to just do this with their entire + + + align:start position:0% +likely to just do this with their entire +range and play a strategy where they're + + align:start position:0% +range and play a strategy where they're + + + align:start position:0% +range and play a strategy where they're +just going on pre- flop a lot so maybe + + align:start position:0% +just going on pre- flop a lot so maybe + + + align:start position:0% +just going on pre- flop a lot so maybe +they could have aces in their range but + + align:start position:0% +they could have aces in their range but + + + align:start position:0% +they could have aces in their range but +nonetheless regardless I think it's not + + align:start position:0% +nonetheless regardless I think it's not + + + align:start position:0% +nonetheless regardless I think it's not +even that close I just R um yeah we + + align:start position:0% +even that close I just R um yeah we + + + align:start position:0% +even that close I just R um yeah we +don't really want to call in frustration + + align:start position:0% +don't really want to call in frustration + + + align:start position:0% +don't really want to call in frustration +cuz you saw what happened to the guy + + align:start position:0% +cuz you saw what happened to the guy + + + align:start position:0% +cuz you saw what happened to the guy +with pocket sevens when they B into our + + align:start position:0% +with pocket sevens when they B into our + + + align:start position:0% +with pocket sevens when they B into our +pocket Jacks in the earlier + + align:start position:0% +pocket Jacks in the earlier + + + align:start position:0% +pocket Jacks in the earlier +hand uh okay so I'll take a short break + + align:start position:0% +hand uh okay so I'll take a short break + + + align:start position:0% +hand uh okay so I'll take a short break +there and then I'll finish up the rest + + align:start position:0% +there and then I'll finish up the rest + + + align:start position:0% +there and then I'll finish up the rest +of the hands in like two minutes + + align:start position:0% + + + + align:start position:0% + +yeah uh okay so I'm going to get started + + align:start position:0% +yeah uh okay so I'm going to get started + + + align:start position:0% +yeah uh okay so I'm going to get started +uh + + align:start position:0% +uh + + + align:start position:0% +uh +okay so so okay so the next hand we get + + align:start position:0% +okay so so okay so the next hand we get + + + align:start position:0% +okay so so okay so the next hand we get +we get King ad off suit and once again + + align:start position:0% +we get King ad off suit and once again + + + align:start position:0% +we get King ad off suit and once again +it's one of these situations where you + + align:start position:0% +it's one of these situations where you + + + align:start position:0% +it's one of these situations where you +know we're not thrilled to be calling + + align:start position:0% +know we're not thrilled to be calling + + + align:start position:0% +know we're not thrilled to be calling +especially now that our odds are even a + + align:start position:0% +especially now that our odds are even a + + + align:start position:0% +especially now that our odds are even a +bit worse cuz they actually made it + + align:start position:0% +bit worse cuz they actually made it + + + align:start position:0% +bit worse cuz they actually made it +2.25x actually a bit more like 2. 35x + + align:start position:0% +2.25x actually a bit more like 2. 35x + + + align:start position:0% +2.25x actually a bit more like 2. 35x +instead of uh 2x so against degenerated + + align:start position:0% +instead of uh 2x so against degenerated + + + align:start position:0% +instead of uh 2x so against degenerated +but I King a off suit two big cards I + + align:start position:0% +but I King a off suit two big cards I + + + align:start position:0% +but I King a off suit two big cards I +think with when we're sort of not that + + align:start position:0% +think with when we're sort of not that + + + align:start position:0% +think with when we're sort of not that +deep the rius and pli ODS don't work + + align:start position:0% +deep the rius and pli ODS don't work + + + align:start position:0% +deep the rius and pli ODS don't work +against us that much so so we + + align:start position:0% +against us that much so so we + + + align:start position:0% +against us that much so so we +call and we got a + + align:start position:0% +call and we got a + + + align:start position:0% +call and we got a +good so we check cuz once again I'm I'm + + align:start position:0% +good so we check cuz once again I'm I'm + + + align:start position:0% +good so we check cuz once again I'm I'm +checking my entire range that's how I + + align:start position:0% +checking my entire range that's how I + + + align:start position:0% +checking my entire range that's how I +choose to play my strategy and they bet + + align:start position:0% +choose to play my strategy and they bet + + + align:start position:0% +choose to play my strategy and they bet +and so this is sort of I think uh I + + align:start position:0% +and so this is sort of I think uh I + + + align:start position:0% +and so this is sort of I think uh I +think this is a somewhat close situation + + align:start position:0% +think this is a somewhat close situation + + + align:start position:0% +think this is a somewhat close situation +because I think um there are some draws + + align:start position:0% +because I think um there are some draws + + + align:start position:0% +because I think um there are some draws +right there is a flush draw and there + + align:start position:0% +right there is a flush draw and there + + + align:start position:0% +right there is a flush draw and there +are a bunch of straight draws if you if + + align:start position:0% +are a bunch of straight draws if you if + + + align:start position:0% +are a bunch of straight draws if you if +someone has Jack 10 or queen Jack or + + align:start position:0% +someone has Jack 10 or queen Jack or + + + align:start position:0% +someone has Jack 10 or queen Jack or +queen 10 so do think there is a decent + + align:start position:0% +queen 10 so do think there is a decent + + + align:start position:0% +queen 10 so do think there is a decent +amount of incentive to just check raise + + align:start position:0% +amount of incentive to just check raise + + + align:start position:0% +amount of incentive to just check raise +all in right so in the second lecture I + + align:start position:0% +all in right so in the second lecture I + + + align:start position:0% +all in right so in the second lecture I +showed you a bunch of examples where on + + align:start position:0% +showed you a bunch of examples where on + + + align:start position:0% +showed you a bunch of examples where on +boards like this you can check risol + + align:start position:0% +boards like this you can check risol + + + align:start position:0% +boards like this you can check risol +with your good hands and check risol + + align:start position:0% +with your good hands and check risol + + + align:start position:0% +with your good hands and check risol +with your draws and it's a pretty + + align:start position:0% +with your draws and it's a pretty + + + align:start position:0% +with your draws and it's a pretty +balanced strategy um because when you + + align:start position:0% +balanced strategy um because when you + + + align:start position:0% +balanced strategy um because when you +have a good hand you have a good hand + + align:start position:0% +have a good hand you have a good hand + + + align:start position:0% +have a good hand you have a good hand +and when you have a draw you have lots + + align:start position:0% +and when you have a draw you have lots + + + align:start position:0% +and when you have a draw you have lots +of outs when you get called um but in + + align:start position:0% +of outs when you get called um but in + + + align:start position:0% +of outs when you get called um but in +this and another advantage of going all + + align:start position:0% +this and another advantage of going all + + + align:start position:0% +this and another advantage of going all +in is let's say I had like let's say I + + align:start position:0% +in is let's say I had like let's say I + + + align:start position:0% +in is let's say I had like let's say I +had like 109 I would probably want to be + + align:start position:0% +had like 109 I would probably want to be + + + align:start position:0% +had like 109 I would probably want to be +raising because with 109 even though we + + align:start position:0% +raising because with 109 even though we + + + align:start position:0% +raising because with 109 even though we +have a pretty good hand we kind of sort + + align:start position:0% +have a pretty good hand we kind of sort + + + align:start position:0% +have a pretty good hand we kind of sort +of want to protect our hand right we + + align:start position:0% +of want to protect our hand right we + + + align:start position:0% +of want to protect our hand right we +don't really want a jack a queen or an + + align:start position:0% +don't really want a jack a queen or an + + + align:start position:0% +don't really want a jack a queen or an +ace to come that much so it's close but + + align:start position:0% +ace to come that much so it's close but + + + align:start position:0% +ace to come that much so it's close but +um but in the end I decided to call and + + align:start position:0% +um but in the end I decided to call and + + + align:start position:0% +um but in the end I decided to call and +I think I and I think I decided I'm just + + align:start position:0% +I think I and I think I decided I'm just + + + align:start position:0% +I think I and I think I decided I'm just +going to play pretty close pretty much + + align:start position:0% +going to play pretty close pretty much + + + align:start position:0% +going to play pretty close pretty much +my entire strategy I'm just going to + + align:start position:0% +my entire strategy I'm just going to + + + align:start position:0% +my entire strategy I'm just going to +call here um as tempting as it is like + + align:start position:0% +call here um as tempting as it is like + + + align:start position:0% +call here um as tempting as it is like +let's say I had I had uh Ace two of + + align:start position:0% +let's say I had I had uh Ace two of + + + align:start position:0% +let's say I had I had uh Ace two of +diamonds or let's say like Queen six of + + align:start position:0% +diamonds or let's say like Queen six of + + + align:start position:0% +diamonds or let's say like Queen six of +diamonds to check raise on I think it's + + align:start position:0% +diamonds to check raise on I think it's + + + align:start position:0% +diamonds to check raise on I think it's +a board where you know there it's + + align:start position:0% +a board where you know there it's + + + align:start position:0% +a board where you know there it's +already + + align:start position:0% +already + + + align:start position:0% +already +and if I have a flush draw I still have + + align:start position:0% +and if I have a flush draw I still have + + + align:start position:0% +and if I have a flush draw I still have +lots of opportunities to Bluff on the + + align:start position:0% +lots of opportunities to Bluff on the + + + align:start position:0% +lots of opportunities to Bluff on the +river and if I have a good hand there's + + align:start position:0% +river and if I have a good hand there's + + + align:start position:0% +river and if I have a good hand there's +not that many outs and especially when I + + align:start position:0% +not that many outs and especially when I + + + align:start position:0% +not that many outs and especially when I +have a king so I'm just going to call + + align:start position:0% +have a king so I'm just going to call + + + align:start position:0% +have a king so I'm just going to call +and hope that the board comes out well + + align:start position:0% +and hope that the board comes out well + + + align:start position:0% +and hope that the board comes out well +which I guess it + + align:start position:0% +which I guess it + + + align:start position:0% +which I guess it +does so so I check again because this is + + align:start position:0% +does so so I check again because this is + + + align:start position:0% +does so so I check again because this is +how I'm playing Jack 10 this is how I'm + + align:start position:0% +how I'm playing Jack 10 this is how I'm + + + align:start position:0% +how I'm playing Jack 10 this is how I'm +playing all my hands essentially so they + + align:start position:0% +playing all my hands essentially so they + + + align:start position:0% +playing all my hands essentially so they +check back the river is kind of bad for + + align:start position:0% +check back the river is kind of bad for + + + align:start position:0% +check back the river is kind of bad for +us but I think it's hard for them to + + align:start position:0% +us but I think it's hard for them to + + + align:start position:0% +us but I think it's hard for them to +have a king at this point so I just bet + + align:start position:0% +have a king at this point so I just bet + + + align:start position:0% +have a king at this point so I just bet +out uh about a bit more than half a pot + + align:start position:0% +out uh about a bit more than half a pot + + + align:start position:0% +out uh about a bit more than half a pot +maybe 60% of pot yeah 60% and and they + + align:start position:0% +maybe 60% of pot yeah 60% and and they + + + align:start position:0% +maybe 60% of pot yeah 60% and and they +oh so they actually call me with A7 + + align:start position:0% +oh so they actually call me with A7 + + + align:start position:0% +oh so they actually call me with A7 +which I think is pretty reasonable like + + align:start position:0% +which I think is pretty reasonable like + + + align:start position:0% +which I think is pretty reasonable like +I think A7 is a fine call against my + + align:start position:0% +I think A7 is a fine call against my + + + align:start position:0% +I think A7 is a fine call against my +strategy um because I could have easily + + align:start position:0% +strategy um because I could have easily + + + align:start position:0% +strategy um because I could have easily +had Jack 10 or queen 10 or queen Jack + + align:start position:0% +had Jack 10 or queen 10 or queen Jack + + + align:start position:0% +had Jack 10 or queen 10 or queen Jack +here um although I probably also play a + + align:start position:0% +here um although I probably also play a + + + align:start position:0% +here um although I probably also play a +nine the same way so they are also + + align:start position:0% +nine the same way so they are also + + + align:start position:0% +nine the same way so they are also +paying off my + + align:start position:0% +paying off my + + + align:start position:0% +paying off my +nines and so one good thing actually so + + align:start position:0% +nines and so one good thing actually so + + + align:start position:0% +nines and so one good thing actually so +this is one uh interesting thing to + + align:start position:0% +this is one uh interesting thing to + + + align:start position:0% +this is one uh interesting thing to +think about that's sort of advanced but + + align:start position:0% +think about that's sort of advanced but + + + align:start position:0% +think about that's sort of advanced but +I think it's cool is the fact that they + + align:start position:0% +I think it's cool is the fact that they + + + align:start position:0% +I think it's cool is the fact that they +have A7 I think makes their call a lot + + align:start position:0% +have A7 I think makes their call a lot + + + align:start position:0% +have A7 I think makes their call a lot +better than if they had say ace 10 or + + align:start position:0% +better than if they had say ace 10 or + + + align:start position:0% +better than if they had say ace 10 or +Ace Jack and the reason for so even + + align:start position:0% +Ace Jack and the reason for so even + + + align:start position:0% +Ace Jack and the reason for so even +though ace7 is in some sense a worse + + align:start position:0% +though ace7 is in some sense a worse + + + align:start position:0% +though ace7 is in some sense a worse +hand than Ace 10 and Ace Jack they're + + align:start position:0% +hand than Ace 10 and Ace Jack they're + + + align:start position:0% +hand than Ace 10 and Ace Jack they're +they're the same on this board and I + + align:start position:0% +they're the same on this board and I + + + align:start position:0% +they're the same on this board and I +think it's a the the problem with Ace 10 + + align:start position:0% +think it's a the the problem with Ace 10 + + + align:start position:0% +think it's a the the problem with Ace 10 +and Ace Jack is if they have a 10 or a + + align:start position:0% +and Ace Jack is if they have a 10 or a + + + align:start position:0% +and Ace Jack is if they have a 10 or a +Jack it's less likely I have a 10 or a + + align:start position:0% +Jack it's less likely I have a 10 or a + + + align:start position:0% +Jack it's less likely I have a 10 or a +Jack so you know cuz when they're + + align:start position:0% +Jack so you know cuz when they're + + + align:start position:0% +Jack so you know cuz when they're +calling with A7 essentially what they're + + align:start position:0% +calling with A7 essentially what they're + + + align:start position:0% +calling with A7 essentially what they're +hoping for is Hing for me to have Jack + + align:start position:0% +hoping for is Hing for me to have Jack + + + align:start position:0% +hoping for is Hing for me to have Jack +10 or queen 10 or queen Jack so if they + + align:start position:0% +10 or queen 10 or queen Jack so if they + + + align:start position:0% +10 or queen 10 or queen Jack so if they +have a ten or or Jack it just decreases + + align:start position:0% +have a ten or or Jack it just decreases + + + align:start position:0% +have a ten or or Jack it just decreases +that chance so it's almost like A7 is a + + align:start position:0% +that chance so it's almost like A7 is a + + + align:start position:0% +that chance so it's almost like A7 is a +better hand to call with an ace Jack so + + align:start position:0% +better hand to call with an ace Jack so + + + align:start position:0% +better hand to call with an ace Jack so +but nonetheless you know with any Ace I + + align:start position:0% +but nonetheless you know with any Ace I + + + align:start position:0% +but nonetheless you know with any Ace I +think calling here is reasonable cuz I + + align:start position:0% +think calling here is reasonable cuz I + + + align:start position:0% +think calling here is reasonable cuz I +do have plenty of Bluffs any Miss + + align:start position:0% +do have plenty of Bluffs any Miss + + + align:start position:0% +do have plenty of Bluffs any Miss +straight draw any Miss plus draw I will + + align:start position:0% +straight draw any Miss plus draw I will + + + align:start position:0% +straight draw any Miss plus draw I will +Bluff in the same way on this + + align:start position:0% + + + + align:start position:0% + +rer okay uh so the next hand so we yeah + + align:start position:0% +rer okay uh so the next hand so we yeah + + + align:start position:0% +rer okay uh so the next hand so we yeah +we won a bunch of pots which is nice so + + align:start position:0% +we won a bunch of pots which is nice so + + + align:start position:0% +we won a bunch of pots which is nice so +we we built our stack up so we got + + align:start position:0% +we we built our stack up so we got + + + align:start position:0% +we we built our stack up so we got +pocket Forest here and this guy raises + + align:start position:0% +pocket Forest here and this guy raises + + + align:start position:0% +pocket Forest here and this guy raises +it to 12200 pocket 4S is definitely a + + align:start position:0% +it to 12200 pocket 4S is definitely a + + + align:start position:0% +it to 12200 pocket 4S is definitely a +hand where I want to be Bluff re raising + + align:start position:0% +hand where I want to be Bluff re raising + + + align:start position:0% +hand where I want to be Bluff re raising +with so I'm not you know I'm not hoping + + align:start position:0% +with so I'm not you know I'm not hoping + + + align:start position:0% +with so I'm not you know I'm not hoping +to get called when I race here but it's + + align:start position:0% +to get called when I race here but it's + + + align:start position:0% +to get called when I race here but it's +a hand that does quite well against the + + align:start position:0% +a hand that does quite well against the + + + align:start position:0% +a hand that does quite well against the +range of hands I get called by because a + + align:start position:0% +range of hands I get called by because a + + + align:start position:0% +range of hands I get called by because a +lot of times it'll just be Ace King Ace + + align:start position:0% +lot of times it'll just be Ace King Ace + + + align:start position:0% +lot of times it'll just be Ace King Ace +Queen and and and they will fold quite a + + align:start position:0% +Queen and and and they will fold quite a + + + align:start position:0% +Queen and and and they will fold quite a +large percent of the time so I + + align:start position:0% +large percent of the time so I + + + align:start position:0% +large percent of the time so I +definitely want to raise the only + + align:start position:0% +definitely want to raise the only + + + align:start position:0% +definitely want to raise the only +question is how do I raise right I could + + align:start position:0% +question is how do I raise right I could + + + align:start position:0% +question is how do I raise right I could +just go all in which has the benefit + + align:start position:0% +just go all in which has the benefit + + + align:start position:0% +just go all in which has the benefit +that they can't call and try to hit a + + align:start position:0% +that they can't call and try to hit a + + + align:start position:0% +that they can't call and try to hit a +pair cuz that would actually be bad like + + align:start position:0% +pair cuz that would actually be bad like + + + align:start position:0% +pair cuz that would actually be bad like +let's say I made it let's say I only re + + align:start position:0% +let's say I made it let's say I only re + + + align:start position:0% +let's say I made it let's say I only re +raised to 3,000 here it's actually kind + + align:start position:0% +raised to 3,000 here it's actually kind + + + align:start position:0% +raised to 3,000 here it's actually kind +of bad if this guy calls with this queen + + align:start position:0% +of bad if this guy calls with this queen + + + align:start position:0% +of bad if this guy calls with this queen +Jack trying to hit a pair because that's + + align:start position:0% +Jack trying to hit a pair because that's + + + align:start position:0% +Jack trying to hit a pair because that's +actually the best strategy that their + + align:start position:0% +actually the best strategy that their + + + align:start position:0% +actually the best strategy that their +basically their obvious strategy is good + + align:start position:0% +basically their obvious strategy is good + + + align:start position:0% +basically their obvious strategy is good +against my hand so I want to either go + + align:start position:0% +against my hand so I want to either go + + + align:start position:0% +against my hand so I want to either go +all in which sort of denies them that + + align:start position:0% +all in which sort of denies them that + + + align:start position:0% +all in which sort of denies them that +opportunity or um or I could but the + + align:start position:0% +opportunity or um or I could but the + + + align:start position:0% +opportunity or um or I could but the +problem with going all in is let's + + align:start position:0% +problem with going all in is let's + + + align:start position:0% +problem with going all in is let's +suppose check raise picks up a hand + + align:start position:0% +suppose check raise picks up a hand + + + align:start position:0% +suppose check raise picks up a hand +right then I'm going to be losing with + + align:start position:0% +right then I'm going to be losing with + + + align:start position:0% +right then I'm going to be losing with +my pocket Force so you know there is + + align:start position:0% +my pocket Force so you know there is + + + align:start position:0% +my pocket Force so you know there is +this delicate balance here and this is + + align:start position:0% +this delicate balance here and this is + + + align:start position:0% +this delicate balance here and this is +why um in this is why I think + + align:start position:0% +why um in this is why I think + + + align:start position:0% +why um in this is why I think +tournaments are interesting because you + + align:start position:0% +tournaments are interesting because you + + + align:start position:0% +tournaments are interesting because you +know there's plays that are good against + + align:start position:0% +know there's plays that are good against + + + align:start position:0% +know there's plays that are good against +big stacks and plays that are good + + align:start position:0% +big stacks and plays that are good + + + align:start position:0% +big stacks and plays that are good +against small Stacks but in reality in a + + align:start position:0% +against small Stacks but in reality in a + + + align:start position:0% +against small Stacks but in reality in a +tournament there's going to be big + + align:start position:0% +tournament there's going to be big + + + align:start position:0% +tournament there's going to be big +stacks and small Stacks at the table and + + align:start position:0% +stacks and small Stacks at the table and + + + align:start position:0% +stacks and small Stacks at the table and +often you do have to compromise between + + align:start position:0% +often you do have to compromise between + + + align:start position:0% +often you do have to compromise between +the lesser of two evils and that's sort + + align:start position:0% +the lesser of two evils and that's sort + + + align:start position:0% +the lesser of two evils and that's sort +of what I do here so I decid to raise + + align:start position:0% +of what I do here so I decid to raise + + + align:start position:0% +of what I do here so I decid to raise +this 3600 which is bigger than I'd + + align:start position:0% +this 3600 which is bigger than I'd + + + align:start position:0% +this 3600 which is bigger than I'd +usually make it usually I'd make it + + align:start position:0% +usually make it usually I'd make it + + + align:start position:0% +usually make it usually I'd make it +maybe like 3,000 but when this guy is + + align:start position:0% +maybe like 3,000 but when this guy is + + + align:start position:0% +maybe like 3,000 but when this guy is +this short + + align:start position:0% +this short + + + align:start position:0% +this short +uh rawful L boom I um I don't really + + align:start position:0% +uh rawful L boom I um I don't really + + + align:start position:0% +uh rawful L boom I um I don't really +want to let them just call but uh on the + + align:start position:0% +want to let them just call but uh on the + + + align:start position:0% +want to let them just call but uh on the +other hand I want to be able to fold if + + align:start position:0% +other hand I want to be able to fold if + + + align:start position:0% +other hand I want to be able to fold if +one of these two guys cheze ra or vamson + + align:start position:0% +one of these two guys cheze ra or vamson + + + align:start position:0% +one of these two guys cheze ra or vamson +picks up a hand so I sort of compromise + + align:start position:0% +picks up a hand so I sort of compromise + + + align:start position:0% +picks up a hand so I sort of compromise +between making it 3600 they both fold + + align:start position:0% +between making it 3600 they both fold + + + align:start position:0% +between making it 3600 they both fold +and this guy also folds which is I guess + + align:start position:0% +and this guy also folds which is I guess + + + align:start position:0% +and this guy also folds which is I guess +an ideal + + align:start position:0% + + + + align:start position:0% + +result okay the next hand we have a + + align:start position:0% +result okay the next hand we have a + + + align:start position:0% +result okay the next hand we have a +queen offit and we make it 1,600 + + align:start position:0% +queen offit and we make it 1,600 + + + align:start position:0% +queen offit and we make it 1,600 +so I I I know I've said make it 2.25x + + align:start position:0% +so I I I know I've said make it 2.25x + + + align:start position:0% +so I I I know I've said make it 2.25x +and I I stand by that I think that's a + + align:start position:0% +and I I stand by that I think that's a + + + align:start position:0% +and I I stand by that I think that's a +good strategy I think at the time I'm + + align:start position:0% +good strategy I think at the time I'm + + + align:start position:0% +good strategy I think at the time I'm +just so once again I'm probably still + + align:start position:0% +just so once again I'm probably still + + + align:start position:0% +just so once again I'm probably still +playing a lot of tables and I'm kind of + + align:start position:0% +playing a lot of tables and I'm kind of + + + align:start position:0% +playing a lot of tables and I'm kind of +lazy so I'm too lazy to type in like + + align:start position:0% +lazy so I'm too lazy to type in like + + + align:start position:0% +lazy so I'm too lazy to type in like +1,00 manually whereas the software + + align:start position:0% +1,00 manually whereas the software + + + align:start position:0% +1,00 manually whereas the software +defaults to just 2x so I tend to just 2x + + align:start position:0% +defaults to just 2x so I tend to just 2x + + + align:start position:0% +defaults to just 2x so I tend to just 2x +but I think it's probably not the + + align:start position:0% +but I think it's probably not the + + + align:start position:0% +but I think it's probably not the +theoretical optimal strategy I would + + align:start position:0% +theoretical optimal strategy I would + + + align:start position:0% +theoretical optimal strategy I would +guess that the optimal thing to do is + + align:start position:0% +guess that the optimal thing to do is + + + align:start position:0% +guess that the optimal thing to do is +closer to + + align:start position:0% +closer to + + + align:start position:0% +closer to +2.25x uh so vamson calls us in position + + align:start position:0% +2.25x uh so vamson calls us in position + + + align:start position:0% +2.25x uh so vamson calls us in position +position and you know so so immediately + + align:start position:0% +position and you know so so immediately + + + align:start position:0% +position and you know so so immediately +I could think of it like what is their + + align:start position:0% +I could think of it like what is their + + + align:start position:0% +I could think of it like what is their +range cuz it's a spot where I expect + + align:start position:0% +range cuz it's a spot where I expect + + + align:start position:0% +range cuz it's a spot where I expect +them to go all in with most of their + + align:start position:0% +them to go all in with most of their + + + align:start position:0% +them to go all in with most of their +good hands so the question is you know + + align:start position:0% +good hands so the question is you know + + + align:start position:0% +good hands so the question is you know +are they trapping me or do they + + align:start position:0% +are they trapping me or do they + + + align:start position:0% +are they trapping me or do they +literally just always have a hand like + + align:start position:0% +literally just always have a hand like + + + align:start position:0% +literally just always have a hand like +Jack 10 suited king queen or something + + align:start position:0% +Jack 10 suited king queen or something + + + align:start position:0% +Jack 10 suited king queen or something +like that so so immediately it's it's + + align:start position:0% +like that so so immediately it's it's + + + align:start position:0% +like that so so immediately it's it's +sort of an interesting spot because I + + align:start position:0% +sort of an interesting spot because I + + + align:start position:0% +sort of an interesting spot because I +expect them to mostly be raising when + + align:start position:0% +expect them to mostly be raising when + + + align:start position:0% +expect them to mostly be raising when +they want to play their + + align:start position:0% +they want to play their + + + align:start position:0% +they want to play their +hand okay so we flop uh 4 + + align:start position:0% +hand okay so we flop uh 4 + + + align:start position:0% +hand okay so we flop uh 4 +109 and it's definitely a pretty bad + + align:start position:0% +109 and it's definitely a pretty bad + + + align:start position:0% +109 and it's definitely a pretty bad +board for us overall like I think you + + align:start position:0% +board for us overall like I think you + + + align:start position:0% +board for us overall like I think you +know if like regardless of their + + align:start position:0% +know if like regardless of their + + + align:start position:0% +know if like regardless of their +strategy like if their strategy is to + + align:start position:0% +strategy like if their strategy is to + + + align:start position:0% +strategy like if their strategy is to +trap us sometimes then this this board + + align:start position:0% +trap us sometimes then this this board + + + align:start position:0% +trap us sometimes then this this board +is just terrible and even if their + + align:start position:0% +is just terrible and even if their + + + align:start position:0% +is just terrible and even if their +strategy isn't to trap us they've always + + align:start position:0% +strategy isn't to trap us they've always + + + align:start position:0% +strategy isn't to trap us they've always +got a straight draw on this board + + align:start position:0% +got a straight draw on this board + + + align:start position:0% +got a straight draw on this board +because they're going to have king queen + + align:start position:0% +because they're going to have king queen + + + align:start position:0% +because they're going to have king queen +or queen Jack or something so I think + + align:start position:0% +or queen Jack or something so I think + + + align:start position:0% +or queen Jack or something so I think +objectively it's a pretty bad board + + align:start position:0% +objectively it's a pretty bad board + + + align:start position:0% +objectively it's a pretty bad board +maybe they could have Ace Jack or Ace + + align:start position:0% +maybe they could have Ace Jack or Ace + + + align:start position:0% +maybe they could have Ace Jack or Ace +Queen thems although Ace Queen I think + + align:start position:0% +Queen thems although Ace Queen I think + + + align:start position:0% +Queen thems although Ace Queen I think +they're definitely raising pre flop so + + align:start position:0% +they're definitely raising pre flop so + + + align:start position:0% +they're definitely raising pre flop so +probably just ace Jack um so I do think + + align:start position:0% +probably just ace Jack um so I do think + + + align:start position:0% +probably just ace Jack um so I do think +we're not in great shape here but I + + align:start position:0% +we're not in great shape here but I + + + align:start position:0% +we're not in great shape here but I +decid to bet anyway essentially just + + align:start position:0% +decid to bet anyway essentially just + + + align:start position:0% +decid to bet anyway essentially just +banking on my as of clubs I I definitely + + align:start position:0% +banking on my as of clubs I I definitely + + + align:start position:0% +banking on my as of clubs I I definitely +wouldn't be betting this without the Ace + + align:start position:0% +wouldn't be betting this without the Ace + + + align:start position:0% +wouldn't be betting this without the Ace +of clubs but my strategy is to bet and + + align:start position:0% +of clubs but my strategy is to bet and + + + align:start position:0% +of clubs but my strategy is to bet and +if I get called I'm going to go all in + + align:start position:0% +if I get called I'm going to go all in + + + align:start position:0% +if I get called I'm going to go all in +on any club turn any Jack queen or east + + align:start position:0% +on any club turn any Jack queen or east + + + align:start position:0% +on any club turn any Jack queen or east +turn so essentially any club turn I have + + align:start position:0% +turn so essentially any club turn I have + + + align:start position:0% +turn so essentially any club turn I have +the nut flush draw any um Jack turn I + + align:start position:0% +the nut flush draw any um Jack turn I + + + align:start position:0% +the nut flush draw any um Jack turn I +have a good I have a good straight draw + + align:start position:0% +have a good I have a good straight draw + + + align:start position:0% +have a good I have a good straight draw +with two overcards and any queen or Ace + + align:start position:0% +with two overcards and any queen or Ace + + + align:start position:0% +with two overcards and any queen or Ace +turn uh gives pairs my hand so I just + + align:start position:0% +turn uh gives pairs my hand so I just + + + align:start position:0% +turn uh gives pairs my hand so I just +think there's enough turns where I can + + align:start position:0% +think there's enough turns where I can + + + align:start position:0% +think there's enough turns where I can +basically continue bluffing continue + + align:start position:0% +basically continue bluffing continue + + + align:start position:0% +basically continue bluffing continue +barreling on that one barrel has to be + + align:start position:0% +barreling on that one barrel has to be + + + align:start position:0% +barreling on that one barrel has to be +okay but I'm only making this play + + align:start position:0% +okay but I'm only making this play + + + align:start position:0% +okay but I'm only making this play +because I have the Ace of clubs like I + + align:start position:0% +because I have the Ace of clubs like I + + + align:start position:0% +because I have the Ace of clubs like I +think even with the Queen of Clubs I + + align:start position:0% +think even with the Queen of Clubs I + + + align:start position:0% +think even with the Queen of Clubs I +probably would have just given up this + + align:start position:0% +probably would have just given up this + + + align:start position:0% +probably would have just given up this +hand um but we do get a fold so I guess + + align:start position:0% +hand um but we do get a fold so I guess + + + align:start position:0% +hand um but we do get a fold so I guess +they probably had Ace Jack that's + + align:start position:0% +they probably had Ace Jack that's + + + align:start position:0% +they probably had Ace Jack that's +probably their most likely hand maybe + + align:start position:0% +probably their most likely hand maybe + + + align:start position:0% +probably their most likely hand maybe +something like pocket sevens they + + align:start position:0% +something like pocket sevens they + + + align:start position:0% +something like pocket sevens they +folded yeah so that sort of shows you + + align:start position:0% +folded yeah so that sort of shows you + + + align:start position:0% +folded yeah so that sort of shows you +the importance sometimes of back door + + align:start position:0% +the importance sometimes of back door + + + align:start position:0% +the importance sometimes of back door +draws because like let's say they had + + align:start position:0% +draws because like let's say they had + + + align:start position:0% +draws because like let's say they had +pocket sevens here like let's say they + + align:start position:0% +pocket sevens here like let's say they + + + align:start position:0% +pocket sevens here like let's say they +called with pocket sevens which I don't + + align:start position:0% +called with pocket sevens which I don't + + + align:start position:0% +called with pocket sevens which I don't +think is + + align:start position:0% +think is + + + align:start position:0% +think is +unreasonable if I didn't have the E of + + align:start position:0% +unreasonable if I didn't have the E of + + + align:start position:0% +unreasonable if I didn't have the E of +clubs I'm going to just have to end up + + align:start position:0% +clubs I'm going to just have to end up + + + align:start position:0% +clubs I'm going to just have to end up +giving up on a bunch of turns and they + + align:start position:0% +giving up on a bunch of turns and they + + + align:start position:0% +giving up on a bunch of turns and they +would take down the PO with their pocket + + align:start position:0% +would take down the PO with their pocket + + + align:start position:0% +would take down the PO with their pocket +sevens but because I have the Ace of + + align:start position:0% +sevens but because I have the Ace of + + + align:start position:0% +sevens but because I have the Ace of +clubs it's just very very unlikely they + + align:start position:0% +clubs it's just very very unlikely they + + + align:start position:0% +clubs it's just very very unlikely they +end up winning the hand with a pair of + + align:start position:0% +end up winning the hand with a pair of + + + align:start position:0% +end up winning the hand with a pair of +sevens cuz I'm going to shove a lot of + + align:start position:0% +sevens cuz I'm going to shove a lot of + + + align:start position:0% +sevens cuz I'm going to shove a lot of +turns and they're just going to have to + + align:start position:0% + + + + align:start position:0% + +fold okay so the next hand we get Queen + + align:start position:0% +fold okay so the next hand we get Queen + + + align:start position:0% +fold okay so the next hand we get Queen +Jack again and we raise here and so the + + align:start position:0% +Jack again and we raise here and so the + + + align:start position:0% +Jack again and we raise here and so the +same gu bamson they call and we get a + + align:start position:0% +same gu bamson they call and we get a + + + align:start position:0% +same gu bamson they call and we get a +good flop um so so I bet okay so I'm + + align:start position:0% +good flop um so so I bet okay so I'm + + + align:start position:0% +good flop um so so I bet okay so I'm +going to talk about this I so I bet, + + align:start position:0% +going to talk about this I so I bet, + + + align:start position:0% +going to talk about this I so I bet, +1600 here which is quite small it's like + + align:start position:0% +1600 here which is quite small it's like + + + align:start position:0% +1600 here which is quite small it's like +40% it's like less than 40% of pot I + + align:start position:0% +40% it's like less than 40% of pot I + + + align:start position:0% +40% it's like less than 40% of pot I +might have done it out of laziness but + + align:start position:0% +might have done it out of laziness but + + + align:start position:0% +might have done it out of laziness but +or I might have just done it because of + + align:start position:0% +or I might have just done it because of + + + align:start position:0% +or I might have just done it because of +my cards because I have two pair and I'm + + align:start position:0% +my cards because I have two pair and I'm + + + align:start position:0% +my cards because I have two pair and I'm +trying to separate him in and get him to + + align:start position:0% +trying to separate him in and get him to + + + align:start position:0% +trying to separate him in and get him to +put in all his money slowly but looking + + align:start position:0% +put in all his money slowly but looking + + + align:start position:0% +put in all his money slowly but looking +back I definitely don't think this is + + align:start position:0% +back I definitely don't think this is + + + align:start position:0% +back I definitely don't think this is +how I want to be playing my entire + + align:start position:0% +how I want to be playing my entire + + + align:start position:0% +how I want to be playing my entire +strategy on this spot like I think I + + align:start position:0% +strategy on this spot like I think I + + + align:start position:0% +strategy on this spot like I think I +want to be betting at least half the pot + + align:start position:0% +want to be betting at least half the pot + + + align:start position:0% +want to be betting at least half the pot +when there's a flush draw a straight + + align:start position:0% +when there's a flush draw a straight + + + align:start position:0% +when there's a flush draw a straight +draw like a bunch of straight draws I + + align:start position:0% +draw like a bunch of straight draws I + + + align:start position:0% +draw like a bunch of straight draws I +definitely think this bet is way too + + align:start position:0% +definitely think this bet is way too + + + align:start position:0% +definitely think this bet is way too +small it's just on average even even if + + align:start position:0% +small it's just on average even even if + + + align:start position:0% +small it's just on average even even if +I have a pretty good hand let's say like + + align:start position:0% +I have a pretty good hand let's say like + + + align:start position:0% +I have a pretty good hand let's say like +Queen n there's just a lot of bad cards + + align:start position:0% +Queen n there's just a lot of bad cards + + + align:start position:0% +Queen n there's just a lot of bad cards +for me that I don't want to be betting + + align:start position:0% +for me that I don't want to be betting + + + align:start position:0% +for me that I don't want to be betting +the small on this board so I don't know + + align:start position:0% +the small on this board so I don't know + + + align:start position:0% +the small on this board so I don't know +if at the time I just like misclicked + + align:start position:0% +if at the time I just like misclicked + + + align:start position:0% +if at the time I just like misclicked +and messed up or I was lazy and I just + + align:start position:0% +and messed up or I was lazy and I just + + + align:start position:0% +and messed up or I was lazy and I just +wanted to make it 2X or I spefic + + align:start position:0% +wanted to make it 2X or I spefic + + + align:start position:0% +wanted to make it 2X or I spefic +spefically had to read that I could + + align:start position:0% +spefically had to read that I could + + + align:start position:0% +spefically had to read that I could +exploit this player by betting small but + + align:start position:0% +exploit this player by betting small but + + + align:start position:0% +exploit this player by betting small but +this is not a balance this is not how I + + align:start position:0% +this is not a balance this is not how I + + + align:start position:0% +this is not a balance this is not how I +would like to balance my strategy and if + + align:start position:0% +would like to balance my strategy and if + + + align:start position:0% +would like to balance my strategy and if +you ever see me doing this most likely I + + align:start position:0% +you ever see me doing this most likely I + + + align:start position:0% +you ever see me doing this most likely I +have a really good hand as I do in this + + align:start position:0% +have a really good hand as I do in this + + + align:start position:0% +have a really good hand as I do in this +case um so unfortunately it doesn't work + + align:start position:0% +case um so unfortunately it doesn't work + + + align:start position:0% +case um so unfortunately it doesn't work +but so I'm going to talk about this a + + align:start position:0% +but so I'm going to talk about this a + + + align:start position:0% +but so I'm going to talk about this a +bit more so I'm going to jump back to + + align:start position:0% +bit more so I'm going to jump back to + + + align:start position:0% +bit more so I'm going to jump back to +Theory just for a bit um so I want to + + align:start position:0% +Theory just for a bit um so I want to + + + align:start position:0% +Theory just for a bit um so I want to +talk I don't think I've talked about + + align:start position:0% +talk I don't think I've talked about + + + align:start position:0% +talk I don't think I've talked about +this before but I want to say that bet + + align:start position:0% +this before but I want to say that bet + + + align:start position:0% +this before but I want to say that bet +sizing depends on board texture so let + + align:start position:0% +sizing depends on board texture so let + + + align:start position:0% +sizing depends on board texture so let +me explain what I mean here so + + align:start position:0% +me explain what I mean here so + + + align:start position:0% +me explain what I mean here so +essentially there's two types of boards + + align:start position:0% +essentially there's two types of boards + + + align:start position:0% +essentially there's two types of boards +there's dry boards and dry boards so I + + align:start position:0% +there's dry boards and dry boards so I + + + align:start position:0% +there's dry boards and dry boards so I +hate this terminology cuz these are two + + align:start position:0% +hate this terminology cuz these are two + + + align:start position:0% +hate this terminology cuz these are two +words that mean opposite things and they + + align:start position:0% +words that mean opposite things and they + + + align:start position:0% +words that mean opposite things and they +sound very similar especially if you + + align:start position:0% +sound very similar especially if you + + + align:start position:0% +sound very similar especially if you +don't runci it but it's dry and dry um + + align:start position:0% +don't runci it but it's dry and dry um + + + align:start position:0% +don't runci it but it's dry and dry um +maybe I can't pronounce them well but + + align:start position:0% +maybe I can't pronounce them well but + + + align:start position:0% +maybe I can't pronounce them well but +okay so dry boards is basically boards + + align:start position:0% +okay so dry boards is basically boards + + + align:start position:0% +okay so dry boards is basically boards +where the winner is mostly decided by + + align:start position:0% +where the winner is mostly decided by + + + align:start position:0% +where the winner is mostly decided by +before the river and you're either way + + align:start position:0% +before the river and you're either way + + + align:start position:0% +before the river and you're either way +ahead or way behind drawing boards is + + align:start position:0% +ahead or way behind drawing boards is + + + align:start position:0% +ahead or way behind drawing boards is +basically boards with lot of flush draws + + align:start position:0% +basically boards with lot of flush draws + + + align:start position:0% +basically boards with lot of flush draws +straight draws where every subsequent + + align:start position:0% +straight draws where every subsequent + + + align:start position:0% +straight draws where every subsequent +cards card can change the board a lot + + align:start position:0% +cards card can change the board a lot + + + align:start position:0% +cards card can change the board a lot +and it's hard to fold because all hands + + align:start position:0% +and it's hard to fold because all hands + + + align:start position:0% +and it's hard to fold because all hands +have Equity so in reality most boards + + align:start position:0% +have Equity so in reality most boards + + + align:start position:0% +have Equity so in reality most boards +you know they're somewhere in between + + align:start position:0% +you know they're somewhere in between + + + align:start position:0% +you know they're somewhere in between +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +spectrum but okay so what are some + + align:start position:0% +spectrum but okay so what are some + + + align:start position:0% +spectrum but okay so what are some +characteristics of dry boards well a + + align:start position:0% +characteristics of dry boards well a + + + align:start position:0% +characteristics of dry boards well a +board tends to be dry if it's paired + + align:start position:0% +board tends to be dry if it's paired + + + align:start position:0% +board tends to be dry if it's paired +like 448 that tends to be pretty dry cuz + + align:start position:0% +like 448 that tends to be pretty dry cuz + + + align:start position:0% +like 448 that tends to be pretty dry cuz +not much is going in most people have + + align:start position:0% +not much is going in most people have + + + align:start position:0% +not much is going in most people have +missed that board um a board is dry if + + align:start position:0% +missed that board um a board is dry if + + + align:start position:0% +missed that board um a board is dry if +the highest card is big like if the + + align:start position:0% +the highest card is big like if the + + + align:start position:0% +the highest card is big like if the +highest card is an ace then against + + align:start position:0% +highest card is an ace then against + + + align:start position:0% +highest card is an ace then against +someone with an ace if you don't have a + + align:start position:0% +someone with an ace if you don't have a + + + align:start position:0% +someone with an ace if you don't have a +FL flush or straight draw you're already + + align:start position:0% +FL flush or straight draw you're already + + + align:start position:0% +FL flush or straight draw you're already +kind of drawing close to dead um whereas + + align:start position:0% +kind of drawing close to dead um whereas + + + align:start position:0% +kind of drawing close to dead um whereas +you know if the highest card is a 10 + + align:start position:0% +you know if the highest card is a 10 + + + align:start position:0% +you know if the highest card is a 10 +then if you have a queen you always have + + align:start position:0% +then if you have a queen you always have + + + align:start position:0% +then if you have a queen you always have +an opportunity to turn a queen and beat + + align:start position:0% +an opportunity to turn a queen and beat + + + align:start position:0% +an opportunity to turn a queen and beat +them um it's dry if there's no middle + + align:start position:0% +them um it's dry if there's no middle + + + align:start position:0% +them um it's dry if there's no middle +cards for straight draws if there's no + + align:start position:0% +cards for straight draws if there's no + + + align:start position:0% +cards for straight draws if there's no +flush draws um or I'd say if there's + + align:start position:0% +flush draws um or I'd say if there's + + + align:start position:0% +flush draws um or I'd say if there's +already four to a flush or already four + + align:start position:0% +already four to a flush or already four + + + align:start position:0% +already four to a flush or already four +to a straight then it's also sort of dry + + align:start position:0% +to a straight then it's also sort of dry + + + align:start position:0% +to a straight then it's also sort of dry +because like if there's already four + + align:start position:0% +because like if there's already four + + + align:start position:0% +because like if there's already four +diamonds then it's also sort of decided + + align:start position:0% +diamonds then it's also sort of decided + + + align:start position:0% +diamonds then it's also sort of decided +who wins already like if you have a big + + align:start position:0% +who wins already like if you have a big + + + align:start position:0% +who wins already like if you have a big +diamond you're just pretty much + + align:start position:0% +diamond you're just pretty much + + + align:start position:0% +diamond you're just pretty much +guaranteed to win barring some fall + + align:start position:0% +guaranteed to win barring some fall + + + align:start position:0% +guaranteed to win barring some fall +house um same with four to a straight if + + align:start position:0% +house um same with four to a straight if + + + align:start position:0% +house um same with four to a straight if +it's like 9 10 Jack Queen if you have a + + align:start position:0% +it's like 9 10 Jack Queen if you have a + + + align:start position:0% +it's like 9 10 Jack Queen if you have a +king you're just pretty much guaranteed + + align:start position:0% +king you're just pretty much guaranteed + + + align:start position:0% +king you're just pretty much guaranteed +to win and so on the other hand what are + + align:start position:0% +to win and so on the other hand what are + + + align:start position:0% +to win and so on the other hand what are +dry boards it's sort of the opposite + + align:start position:0% +dry boards it's sort of the opposite + + + align:start position:0% +dry boards it's sort of the opposite +right small cards why small cards + + align:start position:0% +right small cards why small cards + + + align:start position:0% +right small cards why small cards +because everyone's going to have + + align:start position:0% +because everyone's going to have + + + align:start position:0% +because everyone's going to have +overcards which is 6 outs flush draws or + + align:start position:0% +overcards which is 6 outs flush draws or + + + align:start position:0% +overcards which is 6 outs flush draws or +three du a flush is also very dry + + align:start position:0% +three du a flush is also very dry + + + align:start position:0% +three du a flush is also very dry +because if there's three du a flush then + + align:start position:0% +because if there's three du a flush then + + + align:start position:0% +because if there's three du a flush then +someone with just an any card of that + + align:start position:0% +someone with just an any card of that + + + align:start position:0% +someone with just an any card of that +suit has a flush draw uh boards with + + align:start position:0% +suit has a flush draw uh boards with + + + align:start position:0% +suit has a flush draw uh boards with +straight draws so how should your Play + + align:start position:0% +straight draws so how should your Play + + + align:start position:0% +straight draws so how should your Play +Change on these two types of boards um + + align:start position:0% +Change on these two types of boards um + + + align:start position:0% +Change on these two types of boards um +well on dry boards you can bet pretty + + align:start position:0% +well on dry boards you can bet pretty + + + align:start position:0% +well on dry boards you can bet pretty +small fractions of the pot on the floppy + + align:start position:0% +small fractions of the pot on the floppy + + + align:start position:0% +small fractions of the pot on the floppy +turn and your opponent might not have + + align:start position:0% +turn and your opponent might not have + + + align:start position:0% +turn and your opponent might not have +the odds to call so like you know if the + + align:start position:0% +the odds to call so like you know if the + + + align:start position:0% +the odds to call so like you know if the +Flop is Ace ace2 or maybe Ace A7 with no + + align:start position:0% +Flop is Ace ace2 or maybe Ace A7 with no + + + align:start position:0% +Flop is Ace ace2 or maybe Ace A7 with no +flush draws you can bet like a fifth of + + align:start position:0% +flush draws you can bet like a fifth of + + + align:start position:0% +flush draws you can bet like a fifth of +the pot and your opponent is still going + + align:start position:0% +the pot and your opponent is still going + + + align:start position:0% +the pot and your opponent is still going +to have to fold a lot of their hands + + align:start position:0% +to have to fold a lot of their hands + + + align:start position:0% +to have to fold a lot of their hands +because if you've got an ace they're + + align:start position:0% +because if you've got an ace they're + + + align:start position:0% +because if you've got an ace they're +just way behind um what's another + + align:start position:0% +just way behind um what's another + + + align:start position:0% +just way behind um what's another +characteristic is any draw might be good + + align:start position:0% +characteristic is any draw might be good + + + align:start position:0% +characteristic is any draw might be good +enough to make a bluff so like if the + + align:start position:0% +enough to make a bluff so like if the + + + align:start position:0% +enough to make a bluff so like if the +board is a A7 with no flush draw and + + align:start position:0% +board is a A7 with no flush draw and + + + align:start position:0% +board is a A7 with no flush draw and +you've got like 89 with a back door + + align:start position:0% +you've got like 89 with a back door + + + align:start position:0% +you've got like 89 with a back door +flush draw that's a pretty good hand to + + align:start position:0% +flush draw that's a pretty good hand to + + + align:start position:0% +flush draw that's a pretty good hand to +make a bluff because you've got um + + align:start position:0% +make a bluff because you've got um + + + align:start position:0% +make a bluff because you've got um +you've got three to a straight and three + + align:start position:0% +you've got three to a straight and three + + + align:start position:0% +you've got three to a straight and three +do a flush which is sort of the most you + + align:start position:0% +do a flush which is sort of the most you + + + align:start position:0% +do a flush which is sort of the most you +could possibly ask for on that flop with + + align:start position:0% +could possibly ask for on that flop with + + + align:start position:0% +could possibly ask for on that flop with +respect to draws and another aspect of + + align:start position:0% +respect to draws and another aspect of + + + align:start position:0% +respect to draws and another aspect of +playing Drive boards is sort of slow + + align:start position:0% +playing Drive boards is sort of slow + + + align:start position:0% +playing Drive boards is sort of slow +playing tricky plays are good because + + align:start position:0% +playing tricky plays are good because + + + align:start position:0% +playing tricky plays are good because +the thing that matters isn't preventing + + align:start position:0% +the thing that matters isn't preventing + + + align:start position:0% +the thing that matters isn't preventing +your opponent from seeing the turn in + + align:start position:0% +your opponent from seeing the turn in + + + align:start position:0% +your opponent from seeing the turn in +river and not letting them see outs the + + align:start position:0% +river and not letting them see outs the + + + align:start position:0% +river and not letting them see outs the +thing that matters is sort of convincing + + align:start position:0% +thing that matters is sort of convincing + + + align:start position:0% +thing that matters is sort of convincing +your opponent + + align:start position:0% +your opponent + + + align:start position:0% +your opponent +that you have a good hand when you don't + + align:start position:0% +that you have a good hand when you don't + + + align:start position:0% +that you have a good hand when you don't +or like convincing them that you don't + + align:start position:0% +or like convincing them that you don't + + + align:start position:0% +or like convincing them that you don't +have a good hand when you do so it's all + + align:start position:0% +have a good hand when you do so it's all + + + align:start position:0% +have a good hand when you do so it's all +about tricking your opponent disguising + + align:start position:0% +about tricking your opponent disguising + + + align:start position:0% +about tricking your opponent disguising +these tricky I mean I shouldn't say that + + align:start position:0% +these tricky I mean I shouldn't say that + + + align:start position:0% +these tricky I mean I shouldn't say that +it's not all but like simple play can + + align:start position:0% +it's not all but like simple play can + + + align:start position:0% +it's not all but like simple play can +still be good on dry boards but in + + align:start position:0% +still be good on dry boards but in + + + align:start position:0% +still be good on dry boards but in +general slow playing is reasonable and + + align:start position:0% +general slow playing is reasonable and + + + align:start position:0% +general slow playing is reasonable and +and tricking trying to trick your + + align:start position:0% +and tricking trying to trick your + + + align:start position:0% +and tricking trying to trick your +opponent is is more important whereas on + + align:start position:0% +opponent is is more important whereas on + + + align:start position:0% +opponent is is more important whereas on +draw boards you know you just got to bet + + align:start position:0% +draw boards you know you just got to bet + + + align:start position:0% +draw boards you know you just got to bet +large fractions of the pot before the + + align:start position:0% +large fractions of the pot before the + + + align:start position:0% +large fractions of the pot before the +river because every hand has so many + + align:start position:0% +river because every hand has so many + + + align:start position:0% +river because every hand has so many +outs you really don't want to be giving + + align:start position:0% +outs you really don't want to be giving + + + align:start position:0% +outs you really don't want to be giving +them good odds to call and on the floing + + align:start position:0% +them good odds to call and on the floing + + + align:start position:0% +them good odds to call and on the floing +turn if you don't have anything then + + align:start position:0% +turn if you don't have anything then + + + align:start position:0% +turn if you don't have anything then +just don't put any money in because + + align:start position:0% +just don't put any money in because + + + align:start position:0% +just don't put any money in because +bluffing is pretty moot because so many + + align:start position:0% +bluffing is pretty moot because so many + + + align:start position:0% +bluffing is pretty moot because so many +hands aren't folding because they have + + align:start position:0% +hands aren't folding because they have + + + align:start position:0% +hands aren't folding because they have +oats um and yeah don't really slow play + + align:start position:0% +oats um and yeah don't really slow play + + + align:start position:0% +oats um and yeah don't really slow play +if you have a good hand similarly just + + align:start position:0% +if you have a good hand similarly just + + + align:start position:0% +if you have a good hand similarly just +put all the money in right away because + + align:start position:0% +put all the money in right away because + + + align:start position:0% +put all the money in right away because +they're going to call very often because + + align:start position:0% +they're going to call very often because + + + align:start position:0% +they're going to call very often because +they're always going to have some outs + + align:start position:0% +they're always going to have some outs + + + align:start position:0% +they're always going to have some outs +so that's roughly how uh how the Play + + align:start position:0% +so that's roughly how uh how the Play + + + align:start position:0% +so that's roughly how uh how the Play +Changes okay so uh okay so I'll come + + align:start position:0% +Changes okay so uh okay so I'll come + + + align:start position:0% +Changes okay so uh okay so I'll come +back to this we'll see these hands in a + + align:start position:0% +back to this we'll see these hands in a + + + align:start position:0% +back to this we'll see these hands in a +bit so coming back to this queen Jack + + align:start position:0% +bit so coming back to this queen Jack + + + align:start position:0% +bit so coming back to this queen Jack +Hand the reason why I think my beted is + + align:start position:0% +Hand the reason why I think my beted is + + + align:start position:0% +Hand the reason why I think my beted is +too small is because I would consider + + align:start position:0% +too small is because I would consider + + + align:start position:0% +too small is because I would consider +this queen Jack 3 with a flush draw to + + align:start position:0% +this queen Jack 3 with a flush draw to + + + align:start position:0% +this queen Jack 3 with a flush draw to +be a fairly dry board fairly close to + + align:start position:0% +be a fairly dry board fairly close to + + + align:start position:0% +be a fairly dry board fairly close to +the dry end of the spectrum and for that + + align:start position:0% +the dry end of the spectrum and for that + + + align:start position:0% +the dry end of the spectrum and for that +and I said you know you have to bet big + + align:start position:0% +and I said you know you have to bet big + + + align:start position:0% +and I said you know you have to bet big +fractions of the pot and here I am + + align:start position:0% +fractions of the pot and here I am + + + align:start position:0% +fractions of the pot and here I am +betting close to a third of the pot on + + align:start position:0% +betting close to a third of the pot on + + + align:start position:0% +betting close to a third of the pot on +the Flop so I think it's just not a good + + align:start position:0% +the Flop so I think it's just not a good + + + align:start position:0% +the Flop so I think it's just not a good +strategy but um I take the PT + + align:start position:0% + + + + align:start position:0% + +down okay so the next + + align:start position:0% +down okay so the next + + + align:start position:0% +down okay so the next +hand we have Ace Queen offit and so this + + align:start position:0% +hand we have Ace Queen offit and so this + + + align:start position:0% +hand we have Ace Queen offit and so this +guy calls and so my rule was roughly you + + align:start position:0% +guy calls and so my rule was roughly you + + + align:start position:0% +guy calls and so my rule was roughly you +know raise it to 3x + 1 so three so you + + align:start position:0% +know raise it to 3x + 1 so three so you + + + align:start position:0% +know raise it to 3x + 1 so three so you +count how many limpers there are before + + align:start position:0% +count how many limpers there are before + + + align:start position:0% +count how many limpers there are before +you and you add three to that and you + + align:start position:0% +you and you add three to that and you + + + align:start position:0% +you and you add three to that and you +multiply that by the big blind is + + align:start position:0% +multiply that by the big blind is + + + align:start position:0% +multiply that by the big blind is +roughly what you raise it to so in this + + align:start position:0% +roughly what you raise it to so in this + + + align:start position:0% +roughly what you raise it to so in this +case 4,000 I make it + + align:start position:0% +case 4,000 I make it + + + align:start position:0% +case 4,000 I make it +4250 um if they decide to do some weird + + align:start position:0% +4250 um if they decide to do some weird + + + align:start position:0% +4250 um if they decide to do some weird +limp Rays by the way like if they go all + + align:start position:0% +limp Rays by the way like if they go all + + + align:start position:0% +limp Rays by the way like if they go all +in here I'm definitely calling I'm just + + align:start position:0% +in here I'm definitely calling I'm just + + + align:start position:0% +in here I'm definitely calling I'm just +not going to believe them and Ace Queen + + align:start position:0% +not going to believe them and Ace Queen + + + align:start position:0% +not going to believe them and Ace Queen +offsuit is definitely good enough so + + align:start position:0% +offsuit is definitely good enough so + + + align:start position:0% +offsuit is definitely good enough so +they decid to just call which is a bit + + align:start position:0% +they decid to just call which is a bit + + + align:start position:0% +they decid to just call which is a bit +bit weird considering their odds aren't + + align:start position:0% +bit weird considering their odds aren't + + + align:start position:0% +bit weird considering their odds aren't +that good and they're out of position + + align:start position:0% +that good and they're out of position + + + align:start position:0% +that good and they're out of position +but um we flop three hearts and we have + + align:start position:0% +but um we flop three hearts and we have + + + align:start position:0% +but um we flop three hearts and we have +the queen of hearts and in this + + align:start position:0% +the queen of hearts and in this + + + align:start position:0% +the queen of hearts and in this +situation I'm just betting uh I'm just + + align:start position:0% +situation I'm just betting uh I'm just + + + align:start position:0% +situation I'm just betting uh I'm just +betting pretty big into the pot so I + + align:start position:0% +betting pretty big into the pot so I + + + align:start position:0% +betting pretty big into the pot so I +consider this to be a fairly draw flop + + align:start position:0% +consider this to be a fairly draw flop + + + align:start position:0% +consider this to be a fairly draw flop +so I bet big um and so even though I'm + + align:start position:0% +so I bet big um and so even though I'm + + + align:start position:0% +so I bet big um and so even though I'm +in position so position is sort of an + + align:start position:0% +in position so position is sort of an + + + align:start position:0% +in position so position is sort of an +incentive to maybe bet smaller because + + align:start position:0% +incentive to maybe bet smaller because + + + align:start position:0% +incentive to maybe bet smaller because +you have position on later streets and + + align:start position:0% +you have position on later streets and + + + align:start position:0% +you have position on later streets and +you can control the betting better on + + align:start position:0% +you can control the betting better on + + + align:start position:0% +you can control the betting better on +later streets but so this is a fairly + + align:start position:0% +later streets but so this is a fairly + + + align:start position:0% +later streets but so this is a fairly +big bet considering I'm position but I'm + + align:start position:0% +big bet considering I'm position but I'm + + + align:start position:0% +big bet considering I'm position but I'm +just happy to get it in here um so + + align:start position:0% +just happy to get it in here um so + + + align:start position:0% +just happy to get it in here um so +contrast this with an earlier hand I + + align:start position:0% +contrast this with an earlier hand I + + + align:start position:0% +contrast this with an earlier hand I +think I also had Ace Queen um except uh + + align:start position:0% +think I also had Ace Queen um except uh + + + align:start position:0% +think I also had Ace Queen um except uh +it was only I only had three to a flush + + align:start position:0% +it was only I only had three to a flush + + + align:start position:0% +it was only I only had three to a flush +and I said it was very important that I + + align:start position:0% +and I said it was very important that I + + + align:start position:0% +and I said it was very important that I +had the ace of the suit but here it's + + align:start position:0% +had the ace of the suit but here it's + + + align:start position:0% +had the ace of the suit but here it's +just very hard for me to be in terrible + + align:start position:0% +just very hard for me to be in terrible + + + align:start position:0% +just very hard for me to be in terrible +shape you know like in theory they could + + align:start position:0% +shape you know like in theory they could + + + align:start position:0% +shape you know like in theory they could +have I suppose Ace 9 with the Ace of + + align:start position:0% +have I suppose Ace 9 with the Ace of + + + align:start position:0% +have I suppose Ace 9 with the Ace of +Hearts like that hand would be crushing + + align:start position:0% +Hearts like that hand would be crushing + + + align:start position:0% +Hearts like that hand would be crushing +me cuz I would be drawing to literally + + align:start position:0% +me cuz I would be drawing to literally + + + align:start position:0% +me cuz I would be drawing to literally +three outs to care my queen but it's + + align:start position:0% +three outs to care my queen but it's + + + align:start position:0% +three outs to care my queen but it's +just there's not that many combinations + + align:start position:0% +just there's not that many combinations + + + align:start position:0% +just there's not that many combinations +cuz it it would involve an offit hand + + align:start position:0% +cuz it it would involve an offit hand + + + align:start position:0% +cuz it it would involve an offit hand +which they're way less likely to have + + align:start position:0% +which they're way less likely to have + + + align:start position:0% +which they're way less likely to have +when they call me out of position or it + + align:start position:0% +when they call me out of position or it + + + align:start position:0% +when they call me out of position or it +would involve a hand like pocket kings + + align:start position:0% +would involve a hand like pocket kings + + + align:start position:0% +would involve a hand like pocket kings +with the king of hers which is also + + align:start position:0% +with the king of hers which is also + + + align:start position:0% +with the king of hers which is also +pretty unlikely because they probably + + align:start position:0% +pretty unlikely because they probably + + + align:start position:0% +pretty unlikely because they probably +would have done some raising pre flop so + + align:start position:0% +would have done some raising pre flop so + + + align:start position:0% +would have done some raising pre flop so +I just think no matter what they have + + align:start position:0% +I just think no matter what they have + + + align:start position:0% +I just think no matter what they have +I'm going to be in great shape here and + + align:start position:0% +I'm going to be in great shape here and + + + align:start position:0% +I'm going to be in great shape here and +I just have more than enough outs to + + align:start position:0% +I just have more than enough outs to + + + align:start position:0% +I just have more than enough outs to +just game W and so they + + align:start position:0% + + + + align:start position:0% + +fold okay uh the next thing we have + + align:start position:0% +fold okay uh the next thing we have + + + align:start position:0% +fold okay uh the next thing we have +Queen 10 off so I open from under the + + align:start position:0% +Queen 10 off so I open from under the + + + align:start position:0% +Queen 10 off so I open from under the +gun um I think it's fine you know it + + align:start position:0% +gun um I think it's fine you know it + + + align:start position:0% +gun um I think it's fine you know it +looks a bit loose and it is but I think + + align:start position:0% +looks a bit loose and it is but I think + + + align:start position:0% +looks a bit loose and it is but I think +in terms of raising some smaller cards + + align:start position:0% +in terms of raising some smaller cards + + + align:start position:0% +in terms of raising some smaller cards +to balance it so that I will sometimes + + align:start position:0% +to balance it so that I will sometimes + + + align:start position:0% +to balance it so that I will sometimes +have smaller cards in my hand you know + + align:start position:0% +have smaller cards in my hand you know + + + align:start position:0% +have smaller cards in my hand you know +you can't really ask for more than a + + align:start position:0% +you can't really ask for more than a + + + align:start position:0% +you can't really ask for more than a +studed connector so Queen 10 suited I ra + + align:start position:0% +studed connector so Queen 10 suited I ra + + + align:start position:0% +studed connector so Queen 10 suited I ra +from under the gun and the big blind + + align:start position:0% +from under the gun and the big blind + + + align:start position:0% +from under the gun and the big blind +calls when they're they only start the + + align:start position:0% +calls when they're they only start the + + + align:start position:0% +calls when they're they only start the +hand being 18 bets + + align:start position:0% +hand being 18 bets + + + align:start position:0% +hand being 18 bets +deep so we Flop 2 to10 and I think so + + align:start position:0% +deep so we Flop 2 to10 and I think so + + + align:start position:0% +deep so we Flop 2 to10 and I think so +this is a good example of I think of + + align:start position:0% +this is a good example of I think of + + + align:start position:0% +this is a good example of I think of +very dry board where there's really not + + align:start position:0% +very dry board where there's really not + + + align:start position:0% +very dry board where there's really not +much going on um and it is possible they + + align:start position:0% +much going on um and it is possible they + + + align:start position:0% +much going on um and it is possible they +have a deuce but just in general there's + + align:start position:0% +have a deuce but just in general there's + + + align:start position:0% +have a deuce but just in general there's +no straight draws no flush draws I guess + + align:start position:0% +no straight draws no flush draws I guess + + + align:start position:0% +no straight draws no flush draws I guess +there are some overcards but still it's + + align:start position:0% +there are some overcards but still it's + + + align:start position:0% +there are some overcards but still it's +pretty close to as as dry as you can get + + align:start position:0% +pretty close to as as dry as you can get + + + align:start position:0% +pretty close to as as dry as you can get +get and they checked me and I bet 2,000 + + align:start position:0% +get and they checked me and I bet 2,000 + + + align:start position:0% +get and they checked me and I bet 2,000 +which I think is actually too big here + + align:start position:0% +which I think is actually too big here + + + align:start position:0% +which I think is actually too big here +like to be honest I don't think I needed + + align:start position:0% +like to be honest I don't think I needed + + + align:start position:0% +like to be honest I don't think I needed +to risk this much I mean I have a good + + align:start position:0% +to risk this much I mean I have a good + + + align:start position:0% +to risk this much I mean I have a good +hand but you know if I had if I didn't + + align:start position:0% +hand but you know if I had if I didn't + + + align:start position:0% +hand but you know if I had if I didn't +have a pair I only want to be betting + + align:start position:0% +have a pair I only want to be betting + + + align:start position:0% +have a pair I only want to be betting +like 1, 1500 I think that's a fine size + + align:start position:0% +like 1, 1500 I think that's a fine size + + + align:start position:0% +like 1, 1500 I think that's a fine size +I think betting 1500 is more than enough + + align:start position:0% +I think betting 1500 is more than enough + + + align:start position:0% +I think betting 1500 is more than enough +on this board just because there's + + align:start position:0% +on this board just because there's + + + align:start position:0% +on this board just because there's +really nothing going on and um but I + + align:start position:0% +really nothing going on and um but I + + + align:start position:0% +really nothing going on and um but I +guess I was lazy I bet 2,000 and uh and + + align:start position:0% +guess I was lazy I bet 2,000 and uh and + + + align:start position:0% +guess I was lazy I bet 2,000 and uh and +they call so so yeah so this is the so + + align:start position:0% +they call so so yeah so this is the so + + + align:start position:0% +they call so so yeah so this is the so +as you can see there's a huge difference + + align:start position:0% +as you can see there's a huge difference + + + align:start position:0% +as you can see there's a huge difference +between my flop bet sizing depending on + + align:start position:0% +between my flop bet sizing depending on + + + align:start position:0% +between my flop bet sizing depending on +the texture of the board and that's sort + + align:start position:0% +the texture of the board and that's sort + + + align:start position:0% +the texture of the board and that's sort +of what I want to do drive that's the + + align:start position:0% +of what I want to do drive that's the + + + align:start position:0% +of what I want to do drive that's the +point I wanted to drive across through + + align:start position:0% +point I wanted to drive across through + + + align:start position:0% +point I wanted to drive across through +some of these examples so they call me + + align:start position:0% +some of these examples so they call me + + + align:start position:0% +some of these examples so they call me +so we turn a six and and they they check + + align:start position:0% +so we turn a six and and they they check + + + align:start position:0% +so we turn a six and and they they check +I'm just going to keep it simple and bet + + align:start position:0% +I'm just going to keep it simple and bet + + + align:start position:0% +I'm just going to keep it simple and bet +I'm not going to try anything tricky and + + align:start position:0% +I'm not going to try anything tricky and + + + align:start position:0% +I'm not going to try anything tricky and +obviously I'm not folding with top here + + align:start position:0% +obviously I'm not folding with top here + + + align:start position:0% +obviously I'm not folding with top here +and a flush + + align:start position:0% +and a flush + + + align:start position:0% +and a flush +drop so they go all in I call so we + + align:start position:0% +drop so they go all in I call so we + + + align:start position:0% +drop so they go all in I call so we +remember a flush and it turned out to + + align:start position:0% +remember a flush and it turned out to + + + align:start position:0% +remember a flush and it turned out to +actually be necessary cuz they had a + + align:start position:0% +actually be necessary cuz they had a + + + align:start position:0% +actually be necessary cuz they had a +deuce um so it is possible here I think + + align:start position:0% +deuce um so it is possible here I think + + + align:start position:0% +deuce um so it is possible here I think +for them you have a deuce you know I + + align:start position:0% +for them you have a deuce you know I + + + align:start position:0% +for them you have a deuce you know I +think their play preflop is is a bit + + align:start position:0% +think their play preflop is is a bit + + + align:start position:0% +think their play preflop is is a bit +loose with 29 suited but not completely + + align:start position:0% +loose with 29 suited but not completely + + + align:start position:0% +loose with 29 suited but not completely +terrible cuzz with four .5 to1 odds + + align:start position:0% +terrible cuzz with four .5 to1 odds + + + align:start position:0% +terrible cuzz with four .5 to1 odds +nothing is really that terrible but I + + align:start position:0% +nothing is really that terrible but I + + + align:start position:0% +nothing is really that terrible but I +guess yeah we get lucky but I do think + + align:start position:0% +guess yeah we get lucky but I do think + + + align:start position:0% +guess yeah we get lucky but I do think +their call is a bit marginal cuz we are + + align:start position:0% +their call is a bit marginal cuz we are + + + align:start position:0% +their call is a bit marginal cuz we are +under the gun so you know our range is + + align:start position:0% +under the gun so you know our range is + + + align:start position:0% +under the gun so you know our range is +fairly + + align:start position:0% + + + + align:start position:0% + +strong so that's a nice pop to win so + + align:start position:0% +strong so that's a nice pop to win so + + + align:start position:0% +strong so that's a nice pop to win so +we're we're a fairly big stack now um I + + align:start position:0% +we're we're a fairly big stack now um I + + + align:start position:0% +we're we're a fairly big stack now um I +guess we're chip leader at the table and + + align:start position:0% +guess we're chip leader at the table and + + + align:start position:0% +guess we're chip leader at the table and +check raise Min raises from there and we + + align:start position:0% +check raise Min raises from there and we + + + align:start position:0% +check raise Min raises from there and we +have pocket Deuces I think definitely + + align:start position:0% +have pocket Deuces I think definitely + + + align:start position:0% +have pocket Deuces I think definitely +our hands too weak to go all in with as + + align:start position:0% +our hands too weak to go all in with as + + + align:start position:0% +our hands too weak to go all in with as +a bluff against an under the gun opening + + align:start position:0% +a bluff against an under the gun opening + + + align:start position:0% +a bluff against an under the gun opening +range so the only options really are + + align:start position:0% +range so the only options really are + + + align:start position:0% +range so the only options really are +call or fold uh basically our hand does + + align:start position:0% +call or fold uh basically our hand does + + + align:start position:0% +call or fold uh basically our hand does +have terrible reverse and ply dos post + + align:start position:0% +have terrible reverse and ply dos post + + + align:start position:0% +have terrible reverse and ply dos post +swap though so I think you know I think + + align:start position:0% +swap though so I think you know I think + + + align:start position:0% +swap though so I think you know I think +if you wanted to defold here it wouldn't + + align:start position:0% +if you wanted to defold here it wouldn't + + + align:start position:0% +if you wanted to defold here it wouldn't +be terrible but I guess I think calling + + align:start position:0% +be terrible but I guess I think calling + + + align:start position:0% +be terrible but I guess I think calling +is fine too with 4.5 to1 and also you + + align:start position:0% +is fine too with 4.5 to1 and also you + + + align:start position:0% +is fine too with 4.5 to1 and also you +know in some sense you do have odds to + + align:start position:0% +know in some sense you do have odds to + + + align:start position:0% +know in some sense you do have odds to +set mine here I think because uh because + + align:start position:0% +set mine here I think because uh because + + + align:start position:0% +set mine here I think because uh because +so the chances of hitting a third dece + + align:start position:0% +so the chances of hitting a third dece + + + align:start position:0% +so the chances of hitting a third dece +on the Flop is about one and eight so my + + align:start position:0% +on the Flop is about one and eight so my + + + align:start position:0% +on the Flop is about one and eight so my +odds are only 4.5 to one but there are + + align:start position:0% +odds are only 4.5 to one but there are + + + align:start position:0% +odds are only 4.5 to one but there are +implied odds in the case I do hit a set + + align:start position:0% +implied odds in the case I do hit a set + + + align:start position:0% +implied odds in the case I do hit a set +so like literally if my strategy is call + + align:start position:0% +so like literally if my strategy is call + + + align:start position:0% +so like literally if my strategy is call +and fold unless the pop has a two on it + + align:start position:0% +and fold unless the pop has a two on it + + + align:start position:0% +and fold unless the pop has a two on it +I don't think I'm losing a ton of money + + align:start position:0% +I don't think I'm losing a ton of money + + + align:start position:0% +I don't think I'm losing a ton of money +there and you know if there ever is a + + align:start position:0% +there and you know if there ever is a + + + align:start position:0% +there and you know if there ever is a +case where I where they check down and I + + align:start position:0% +case where I where they check down and I + + + align:start position:0% +case where I where they check down and I +get to take down the pot with just a + + align:start position:0% +get to take down the pot with just a + + + align:start position:0% +get to take down the pot with just a +pair of twos then I'm just printing + + align:start position:0% +pair of twos then I'm just printing + + + align:start position:0% +pair of twos then I'm just printing +money by calling so so I said call The + + align:start position:0% +money by calling so so I said call The + + + align:start position:0% +money by calling so so I said call The +Flop is the Flop doesn't have a two so + + align:start position:0% +Flop is the Flop doesn't have a two so + + + align:start position:0% +Flop is the Flop doesn't have a two so +it's bad but you know out of the flops I + + align:start position:0% +it's bad but you know out of the flops I + + + align:start position:0% +it's bad but you know out of the flops I +don't have a two it's probably not that + + align:start position:0% +don't have a two it's probably not that + + + align:start position:0% +don't have a two it's probably not that +bad considering the the three and seven + + align:start position:0% +bad considering the the three and seven + + + align:start position:0% +bad considering the the three and seven +is not that likely to PIR him when he's + + align:start position:0% +is not that likely to PIR him when he's + + + align:start position:0% +is not that likely to PIR him when he's +under the gun but nonetheless I fold you + + align:start position:0% +under the gun but nonetheless I fold you + + + align:start position:0% +under the gun but nonetheless I fold you +know like if I could do the cheat I + + align:start position:0% +know like if I could do the cheat I + + + align:start position:0% +know like if I could do the cheat I +talked about where I could disconnect + + align:start position:0% +talked about where I could disconnect + + + align:start position:0% +talked about where I could disconnect +and call and see the river I definitely + + align:start position:0% +and call and see the river I definitely + + + align:start position:0% +and call and see the river I definitely +would but you know if I call I have to + + align:start position:0% +would but you know if I call I have to + + + align:start position:0% +would but you know if I call I have to +decide again on the turn rther to call + + align:start position:0% +decide again on the turn rther to call + + + align:start position:0% +decide again on the turn rther to call +and decide again on the River weather to + + align:start position:0% +and decide again on the River weather to + + + align:start position:0% +and decide again on the River weather to +call and it's just not going to be a + + align:start position:0% +call and it's just not going to be a + + + align:start position:0% +call and it's just not going to be a +good situation even though for this + + align:start position:0% +good situation even though for this + + + align:start position:0% +good situation even though for this +immediate bet I think I definitely have + + align:start position:0% +immediate bet I think I definitely have + + + align:start position:0% +immediate bet I think I definitely have +odds to call uh with a back door flush + + align:start position:0% +odds to call uh with a back door flush + + + align:start position:0% +odds to call uh with a back door flush +draw and often they're just going to + + align:start position:0% +draw and often they're just going to + + + align:start position:0% +draw and often they're just going to +have Ace King but it's just impossible + + align:start position:0% +have Ace King but it's just impossible + + + align:start position:0% +have Ace King but it's just impossible +play the hand in this sort of just + + align:start position:0% +play the hand in this sort of just + + + align:start position:0% +play the hand in this sort of just +demonstrates you know why it's very + + align:start position:0% +demonstrates you know why it's very + + + align:start position:0% +demonstrates you know why it's very +risky when you decide to play hand like + + align:start position:0% +risky when you decide to play hand like + + + align:start position:0% +risky when you decide to play hand like +pocket Deuces out of position CU it's + + align:start position:0% +pocket Deuces out of position CU it's + + + align:start position:0% +pocket Deuces out of position CU it's +it's very easy to get roped in right + + align:start position:0% +it's very easy to get roped in right + + + align:start position:0% +it's very easy to get roped in right +like let's say I call here and then I + + align:start position:0% +like let's say I call here and then I + + + align:start position:0% +like let's say I call here and then I +call the Flop thinking they might have a + + align:start position:0% +call the Flop thinking they might have a + + + align:start position:0% +call the Flop thinking they might have a +king they bet small so I have good odds + + align:start position:0% +king they bet small so I have good odds + + + align:start position:0% +king they bet small so I have good odds +and I have a back door flash drop so + + align:start position:0% +and I have a back door flash drop so + + + align:start position:0% +and I have a back door flash drop so +let's say I call and then the turn is + + align:start position:0% +let's say I call and then the turn is + + + align:start position:0% +let's say I call and then the turn is +like the five of clubs or something and + + align:start position:0% +like the five of clubs or something and + + + align:start position:0% +like the five of clubs or something and +then they bet like 40% of pot well like + + align:start position:0% +then they bet like 40% of pot well like + + + align:start position:0% +then they bet like 40% of pot well like +am I going to talk talk myself into a + + align:start position:0% +am I going to talk talk myself into a + + + align:start position:0% +am I going to talk talk myself into a +call again maybe because now I hit a + + align:start position:0% +call again maybe because now I hit a + + + align:start position:0% +call again maybe because now I hit a +third Club but if I do then if the river + + align:start position:0% +third Club but if I do then if the river + + + align:start position:0% +third Club but if I do then if the river +something random I have to so it's just + + align:start position:0% +something random I have to so it's just + + + align:start position:0% +something random I have to so it's just +all these decisions that I'm not going + + align:start position:0% +all these decisions that I'm not going + + + align:start position:0% +all these decisions that I'm not going +to be able to make well whereas for my + + align:start position:0% +to be able to make well whereas for my + + + align:start position:0% +to be able to make well whereas for my +opponent it's going to be fairly easy + + align:start position:0% +opponent it's going to be fairly easy + + + align:start position:0% +opponent it's going to be fairly easy +they're going to just Bluff their bad + + align:start position:0% +they're going to just Bluff their bad + + + align:start position:0% +they're going to just Bluff their bad +hands value bet their good hands and + + align:start position:0% +hands value bet their good hands and + + + align:start position:0% +hands value bet their good hands and +check down the hands in the middle which + + align:start position:0% +check down the hands in the middle which + + + align:start position:0% +check down the hands in the middle which +beat + + align:start position:0% + + + + align:start position:0% + +me okay so the next hand we get Ace King + + align:start position:0% +me okay so the next hand we get Ace King + + + align:start position:0% +me okay so the next hand we get Ace King +off suit and we raise and the big blind + + align:start position:0% +off suit and we raise and the big blind + + + align:start position:0% +off suit and we raise and the big blind +calls flop is 927 so note that the big + + align:start position:0% +calls flop is 927 so note that the big + + + align:start position:0% +calls flop is 927 so note that the big +blind just got moved to the table and + + align:start position:0% +blind just got moved to the table and + + + align:start position:0% +blind just got moved to the table and +they actually cover us so so they're + + align:start position:0% +they actually cover us so so they're + + + align:start position:0% +they actually cover us so so they're +they're probably one of the biggest + + align:start position:0% +they're probably one of the biggest + + + align:start position:0% +they're probably one of the biggest +Stacks in the tournament um so they + + align:start position:0% +Stacks in the tournament um so they + + + align:start position:0% +Stacks in the tournament um so they +checked to us I decided to check back + + align:start position:0% +checked to us I decided to check back + + + align:start position:0% +checked to us I decided to check back +here which I don't think is terrible but + + align:start position:0% +here which I don't think is terrible but + + + align:start position:0% +here which I don't think is terrible but +I think it's a bit of a scared play that + + align:start position:0% +I think it's a bit of a scared play that + + + align:start position:0% +I think it's a bit of a scared play that +I I think I would have rather saw myself + + align:start position:0% +I I think I would have rather saw myself + + + align:start position:0% +I I think I would have rather saw myself +bet um you know if it was shallower like + + align:start position:0% +bet um you know if it was shallower like + + + align:start position:0% +bet um you know if it was shallower like +let's say we only had 20,000 chips then + + align:start position:0% +let's say we only had 20,000 chips then + + + align:start position:0% +let's say we only had 20,000 chips then +I think just checking is good because if + + align:start position:0% +I think just checking is good because if + + + align:start position:0% +I think just checking is good because if +I bet they're probably going to be check + + align:start position:0% +I bet they're probably going to be check + + + align:start position:0% +I bet they're probably going to be check +raising with a lot of their flush draws + + align:start position:0% +raising with a lot of their flush draws + + + align:start position:0% +raising with a lot of their flush draws +straight draws and then like pairs of + + align:start position:0% +straight draws and then like pairs of + + + align:start position:0% +straight draws and then like pairs of +nines or pairs of sevens and I'm going + + align:start position:0% +nines or pairs of sevens and I'm going + + + align:start position:0% +nines or pairs of sevens and I'm going +to have to fold with a pretty good hand + + align:start position:0% +to have to fold with a pretty good hand + + + align:start position:0% +to have to fold with a pretty good hand +where I have two good overcards and a + + align:start position:0% +where I have two good overcards and a + + + align:start position:0% +where I have two good overcards and a +back door flash drop but when it's this + + align:start position:0% +back door flash drop but when it's this + + + align:start position:0% +back door flash drop but when it's this +deep you know they they really can't + + align:start position:0% +deep you know they they really can't + + + align:start position:0% +deep you know they they really can't +just check raise a nine CU they're going + + align:start position:0% +just check raise a nine CU they're going + + + align:start position:0% +just check raise a nine CU they're going +to have to be worried about pocket aces + + align:start position:0% +to have to be worried about pocket aces + + + align:start position:0% +to have to be worried about pocket aces +on our part so so I think it's we're not + + align:start position:0% +on our part so so I think it's we're not + + + align:start position:0% +on our part so so I think it's we're not +going to get check raised that often and + + align:start position:0% +going to get check raised that often and + + + align:start position:0% +going to get check raised that often and +by betting we just make the pot bigger + + align:start position:0% +by betting we just make the pot bigger + + + align:start position:0% +by betting we just make the pot bigger +when we do hit a king or an Ace and also + + align:start position:0% +when we do hit a king or an Ace and also + + + align:start position:0% +when we do hit a king or an Ace and also +make it more likely that we can Bluff + + align:start position:0% +make it more likely that we can Bluff + + + align:start position:0% +make it more likely that we can Bluff +them off a 9 or a seven by the river so + + align:start position:0% +them off a 9 or a seven by the river so + + + align:start position:0% +them off a 9 or a seven by the river so +I would have liked to see myself bet but + + align:start position:0% +I would have liked to see myself bet but + + + align:start position:0% +I would have liked to see myself bet but +I don't think checking is terrible by + + align:start position:0% +I don't think checking is terrible by + + + align:start position:0% +I don't think checking is terrible by +the argument that I will most of the + + align:start position:0% +the argument that I will most of the + + + align:start position:0% +the argument that I will most of the +time you know by betting I am folding + + align:start position:0% +time you know by betting I am folding + + + align:start position:0% +time you know by betting I am folding +out basically all the hands that I beat + + align:start position:0% +out basically all the hands that I beat + + + align:start position:0% +out basically all the hands that I beat +and keeping in all the hands that beat + + align:start position:0% +and keeping in all the hands that beat + + + align:start position:0% +and keeping in all the hands that beat +me so it's close but I would have lik to + + align:start position:0% +me so it's close but I would have lik to + + + align:start position:0% +me so it's close but I would have lik to +see myself that but as played you know + + align:start position:0% +see myself that but as played you know + + + align:start position:0% +see myself that but as played you know +if I'm going to check the Flop I'm not + + align:start position:0% +if I'm going to check the Flop I'm not + + + align:start position:0% +if I'm going to check the Flop I'm not +going to bet this turn cuz the whole + + align:start position:0% +going to bet this turn cuz the whole + + + align:start position:0% +going to bet this turn cuz the whole +point of betting the Flop is so that I + + align:start position:0% +point of betting the Flop is so that I + + + align:start position:0% +point of betting the Flop is so that I +could potentially bet the turn and bet + + align:start position:0% +could potentially bet the turn and bet + + + align:start position:0% +could potentially bet the turn and bet +the river and get him to fold a pair of + + align:start position:0% +the river and get him to fold a pair of + + + align:start position:0% +the river and get him to fold a pair of +nines or a pair of sevens but by now I'm + + align:start position:0% +nines or a pair of sevens but by now I'm + + + align:start position:0% +nines or a pair of sevens but by now I'm +not going to really have any hope of + + align:start position:0% +not going to really have any hope of + + + align:start position:0% +not going to really have any hope of +getting him to fold a nine and I'm just + + align:start position:0% +getting him to fold a nine and I'm just + + + align:start position:0% +getting him to fold a nine and I'm just +going to try to win the pot with my East + + align:start position:0% +going to try to win the pot with my East + + + align:start position:0% +going to try to win the pot with my East +King High and so I just check it down um + + align:start position:0% +King High and so I just check it down um + + + align:start position:0% +King High and so I just check it down um +the river check I think is very very + + align:start position:0% +the river check I think is very very + + + align:start position:0% +the river check I think is very very +obvious because I'm literally only + + align:start position:0% +obvious because I'm literally only + + + align:start position:0% +obvious because I'm literally only +getting called by better hands if I bet + + align:start position:0% +getting called by better hands if I bet + + + align:start position:0% +getting called by better hands if I bet +the river so they so they have Queen 10 + + align:start position:0% +the river so they so they have Queen 10 + + + align:start position:0% +the river so they so they have Queen 10 +I think they probably should have + + align:start position:0% +I think they probably should have + + + align:start position:0% +I think they probably should have +bluffed the river I think Queen 10 is + + align:start position:0% +bluffed the river I think Queen 10 is + + + align:start position:0% +bluffed the river I think Queen 10 is +weak enough where they're just very + + align:start position:0% +weak enough where they're just very + + + align:start position:0% +weak enough where they're just very +rarely winning the pot with Queen 10 + + align:start position:0% +rarely winning the pot with Queen 10 + + + align:start position:0% +rarely winning the pot with Queen 10 +high that they basically need to Bluff + + align:start position:0% +high that they basically need to Bluff + + + align:start position:0% +high that they basically need to Bluff +and then put me to a decision but nice + + align:start position:0% +and then put me to a decision but nice + + + align:start position:0% +and then put me to a decision but nice +to win + + align:start position:0% +to win + + + align:start position:0% +to win +that + + align:start position:0% +that + + + align:start position:0% +that +okay the next hand we have Jack 10 so + + align:start position:0% +okay the next hand we have Jack 10 so + + + align:start position:0% +okay the next hand we have Jack 10 so +not too exciting so this same guy who's + + align:start position:0% +not too exciting so this same guy who's + + + align:start position:0% +not too exciting so this same guy who's +now the button raises from the button + + align:start position:0% +now the button raises from the button + + + align:start position:0% +now the button raises from the button +and we call and we flop nothing so the + + align:start position:0% +and we call and we flop nothing so the + + + align:start position:0% +and we call and we flop nothing so the +best thing to do is Bluff off all your + + align:start position:0% +best thing to do is Bluff off all your + + + align:start position:0% +best thing to do is Bluff off all your +chips but no I + + align:start position:0% + + + + align:start position:0% + +juston okay so the next hand is also + + align:start position:0% +juston okay so the next hand is also + + + align:start position:0% +juston okay so the next hand is also +against this Garla edu so we're actually + + align:start position:0% +against this Garla edu so we're actually + + + align:start position:0% +against this Garla edu so we're actually +playing so the two big Stacks at the + + align:start position:0% +playing so the two big Stacks at the + + + align:start position:0% +playing so the two big Stacks at the +table are actually playing a lot of + + align:start position:0% +table are actually playing a lot of + + + align:start position:0% +table are actually playing a lot of +hands against each other um I just call + + align:start position:0% +hands against each other um I just call + + + align:start position:0% +hands against each other um I just call +here with Jacks I think I don't think it + + align:start position:0% +here with Jacks I think I don't think it + + + align:start position:0% +here with Jacks I think I don't think it +would be terrible to just raise and get + + align:start position:0% +would be terrible to just raise and get + + + align:start position:0% +would be terrible to just raise and get +it all in but I think it's it's it is + + align:start position:0% +it all in but I think it's it's it is + + + align:start position:0% +it all in but I think it's it's it is +sort of unnecessarily risky like I think + + align:start position:0% +sort of unnecessarily risky like I think + + + align:start position:0% +sort of unnecessarily risky like I think +um I think it wouldn't be it wouldn't be + + align:start position:0% +um I think it wouldn't be it wouldn't be + + + align:start position:0% +um I think it wouldn't be it wouldn't be +a terrible play to just raise and get it + + align:start position:0% +a terrible play to just raise and get it + + + align:start position:0% +a terrible play to just raise and get it +all in but it's definitely thin like + + align:start position:0% +all in but it's definitely thin like + + + align:start position:0% +all in but it's definitely thin like +you're not printing value by raising and + + align:start position:0% +you're not printing value by raising and + + + align:start position:0% +you're not printing value by raising and +getting it all in because if they rra + + align:start position:0% +getting it all in because if they rra + + + align:start position:0% +getting it all in because if they rra +all in their range is going to be pretty + + align:start position:0% +all in their range is going to be pretty + + + align:start position:0% +all in their range is going to be pretty +strong and pocket Jacks is not really + + align:start position:0% +strong and pocket Jacks is not really + + + align:start position:0% +strong and pocket Jacks is not really +crushing them so um I think you need to + + align:start position:0% +crushing them so um I think you need to + + + align:start position:0% +crushing them so um I think you need to +have queens or better to really be + + align:start position:0% +have queens or better to really be + + + align:start position:0% +have queens or better to really be +hoping to get it on against uh this guy + + align:start position:0% +hoping to get it on against uh this guy + + + align:start position:0% +hoping to get it on against uh this guy +here so with Jack I just call and also + + align:start position:0% +here so with Jack I just call and also + + + align:start position:0% +here so with Jack I just call and also +you know this protects my calling range + + align:start position:0% +you know this protects my calling range + + + align:start position:0% +you know this protects my calling range +of bit like let's say let's say like + + align:start position:0% +of bit like let's say let's say like + + + align:start position:0% +of bit like let's say let's say like +check Rays thinks I'm weak and decides + + align:start position:0% +check Rays thinks I'm weak and decides + + + align:start position:0% +check Rays thinks I'm weak and decides +to make a play here and they R ra to + + align:start position:0% +to make a play here and they R ra to + + + align:start position:0% +to make a play here and they R ra to +like 10,000 then if Gara Ed folds I can + + align:start position:0% +like 10,000 then if Gara Ed folds I can + + + align:start position:0% +like 10,000 then if Gara Ed folds I can +come back around and go all in and sort + + align:start position:0% +come back around and go all in and sort + + + align:start position:0% +come back around and go all in and sort +of surprise them so it does protect my + + align:start position:0% +of surprise them so it does protect my + + + align:start position:0% +of surprise them so it does protect my +calling range a bit as well I call we + + align:start position:0% +calling range a bit as well I call we + + + align:start position:0% +calling range a bit as well I call we +get a 965 flop um they check and I bet + + align:start position:0% +get a 965 flop um they check and I bet + + + align:start position:0% +get a 965 flop um they check and I bet +and I think betting is a fairly natural + + align:start position:0% +and I think betting is a fairly natural + + + align:start position:0% +and I think betting is a fairly natural +play you know I don't want to give Ace + + align:start position:0% +play you know I don't want to give Ace + + + align:start position:0% +play you know I don't want to give Ace +King outs and I just want to win the + + align:start position:0% +King outs and I just want to win the + + + align:start position:0% +King outs and I just want to win the +pawn right now but I was thinking to + + align:start position:0% +pawn right now but I was thinking to + + + align:start position:0% +pawn right now but I was thinking to +myself after that you know if they check + + align:start position:0% +myself after that you know if they check + + + align:start position:0% +myself after that you know if they check +raised here that's really a gross spot I + + align:start position:0% +raised here that's really a gross spot I + + + align:start position:0% +raised here that's really a gross spot I +I actually I I would hate my life if + + align:start position:0% +I actually I I would hate my life if + + + align:start position:0% +I actually I I would hate my life if +they check raised here because I I + + align:start position:0% +they check raised here because I I + + + align:start position:0% +they check raised here because I I +literally don't know what I should do + + align:start position:0% +literally don't know what I should do + + + align:start position:0% +literally don't know what I should do +it's at in one on one hand I would you + + align:start position:0% +it's at in one on one hand I would you + + + align:start position:0% +it's at in one on one hand I would you +know I would be inclined to fold because + + align:start position:0% +know I would be inclined to fold because + + + align:start position:0% +know I would be inclined to fold because +it's kind of weird for them to want to + + align:start position:0% +it's kind of weird for them to want to + + + align:start position:0% +it's kind of weird for them to want to +check raise me here I think without um + + align:start position:0% +check raise me here I think without um + + + align:start position:0% +check raise me here I think without um +having it without having like a big pair + + align:start position:0% +having it without having like a big pair + + + align:start position:0% +having it without having like a big pair +or flush draw with lots of outs but at + + align:start position:0% +or flush draw with lots of outs but at + + + align:start position:0% +or flush draw with lots of outs but at +the same time it's just you know why + + align:start position:0% +the same time it's just you know why + + + align:start position:0% +the same time it's just you know why +would they check pocket aces to me here + + align:start position:0% +would they check pocket aces to me here + + + align:start position:0% +would they check pocket aces to me here +maybe they try to trap me so um it would + + align:start position:0% +maybe they try to trap me so um it would + + + align:start position:0% +maybe they try to trap me so um it would +have been a really gross spot I think if + + align:start position:0% +have been a really gross spot I think if + + + align:start position:0% +have been a really gross spot I think if +I got check raised and by that argument + + align:start position:0% +I got check raised and by that argument + + + align:start position:0% +I got check raised and by that argument +I think against a very tricky player who + + align:start position:0% +I think against a very tricky player who + + + align:start position:0% +I think against a very tricky player who +could be check raising her as a trap and + + align:start position:0% +could be check raising her as a trap and + + + align:start position:0% +could be check raising her as a trap and +as a bluff with a Balan strategy maybe + + align:start position:0% +as a bluff with a Balan strategy maybe + + + align:start position:0% +as a bluff with a Balan strategy maybe +checking is better just to protect + + align:start position:0% +checking is better just to protect + + + align:start position:0% +checking is better just to protect +myself from that but I think against him + + align:start position:0% +myself from that but I think against him + + + align:start position:0% +myself from that but I think against him +I was reasonably confident nothing crazy + + align:start position:0% +I was reasonably confident nothing crazy + + + align:start position:0% +I was reasonably confident nothing crazy +was going to happen um and yeah so they + + align:start position:0% +was going to happen um and yeah so they + + + align:start position:0% +was going to happen um and yeah so they +just folded + + align:start position:0% + + + + align:start position:0% + +okay so it's against this guy again I + + align:start position:0% +okay so it's against this guy again I + + + align:start position:0% +okay so it's against this guy again I +guess we're playing a lot of pots + + align:start position:0% +guess we're playing a lot of pots + + + align:start position:0% +guess we're playing a lot of pots +against the same player um I think it's + + align:start position:0% +against the same player um I think it's + + + align:start position:0% +against the same player um I think it's +getting fairly late into the tournament + + align:start position:0% +getting fairly late into the tournament + + + align:start position:0% +getting fairly late into the tournament +at this point it's not a huge tournament + + align:start position:0% +at this point it's not a huge tournament + + + align:start position:0% +at this point it's not a huge tournament +maybe like 80 90 players and it's + + align:start position:0% +maybe like 80 90 players and it's + + + align:start position:0% +maybe like 80 90 players and it's +probably down to like 2025 at this point + + align:start position:0% +probably down to like 2025 at this point + + + align:start position:0% +probably down to like 2025 at this point +so they raise we call with Queen eight + + align:start position:0% +so they raise we call with Queen eight + + + align:start position:0% +so they raise we call with Queen eight +off we're a bit deep here so our reverse + + align:start position:0% +off we're a bit deep here so our reverse + + + align:start position:0% +off we're a bit deep here so our reverse +implied odds are actually sort of bad + + align:start position:0% +implied odds are actually sort of bad + + + align:start position:0% +implied odds are actually sort of bad +but um but we decided to call and we + + align:start position:0% +but um but we decided to call and we + + + align:start position:0% +but um but we decided to call and we +flopped 235 so I'm just going to here + + align:start position:0% +flopped 235 so I'm just going to here + + + align:start position:0% +flopped 235 so I'm just going to here +but they decide to check and then we + + align:start position:0% +but they decide to check and then we + + + align:start position:0% +but they decide to check and then we +turn a flush draw but I'm still just + + align:start position:0% +turn a flush draw but I'm still just + + + align:start position:0% +turn a flush draw but I'm still just +going to check and basically bet bet + + align:start position:0% +going to check and basically bet bet + + + align:start position:0% +going to check and basically bet bet +pretty much every river um maybe not an + + align:start position:0% +pretty much every river um maybe not an + + + align:start position:0% +pretty much every river um maybe not an +eight River but so we River a six and I + + align:start position:0% +eight River but so we River a six and I + + + align:start position:0% +eight River but so we River a six and I +essentially bet is a bluff because our + + align:start position:0% +essentially bet is a bluff because our + + + align:start position:0% +essentially bet is a bluff because our +hand has no hope of winning if if it + + align:start position:0% +hand has no hope of winning if if it + + + align:start position:0% +hand has no hope of winning if if it +gets to Showdown and and it works this + + align:start position:0% +gets to Showdown and and it works this + + + align:start position:0% +gets to Showdown and and it works this +time so so yeah we played a lot of pots + + align:start position:0% +time so so yeah we played a lot of pots + + + align:start position:0% +time so so yeah we played a lot of pots +against them and it seems like they are + + align:start position:0% +against them and it seems like they are + + + align:start position:0% +against them and it seems like they are +fairly willing to just um check and fold + + align:start position:0% +fairly willing to just um check and fold + + + align:start position:0% +fairly willing to just um check and fold +their hands so not too aggressive so I I + + align:start position:0% +their hands so not too aggressive so I I + + + align:start position:0% +their hands so not too aggressive so I I +guess one thing to keep in mind is maybe + + align:start position:0% +guess one thing to keep in mind is maybe + + + align:start position:0% +guess one thing to keep in mind is maybe +we should get out of the way if we do + + align:start position:0% +we should get out of the way if we do + + + align:start position:0% +we should get out of the way if we do +see them + + align:start position:0% + + + + align:start position:0% + +raising um okay so this situation is + + align:start position:0% +raising um okay so this situation is + + + align:start position:0% +raising um okay so this situation is +similar to the situation the very + + align:start position:0% +similar to the situation the very + + + align:start position:0% +similar to the situation the very +firstand we discussed where we had king + + align:start position:0% +firstand we discussed where we had king + + + align:start position:0% +firstand we discussed where we had king +queen and we had roughly 30 big lines + + align:start position:0% +queen and we had roughly 30 big lines + + + align:start position:0% +queen and we had roughly 30 big lines +and I talked sort of about the benefits + + align:start position:0% +and I talked sort of about the benefits + + + align:start position:0% +and I talked sort of about the benefits +of raising versus calling it's pretty + + align:start position:0% +of raising versus calling it's pretty + + + align:start position:0% +of raising versus calling it's pretty +much the exact same situation and I + + align:start position:0% +much the exact same situation and I + + + align:start position:0% +much the exact same situation and I +decid to sort of raise essentially as a + + align:start position:0% +decid to sort of raise essentially as a + + + align:start position:0% +decid to sort of raise essentially as a +bluff but also king queen plays pretty + + align:start position:0% +bluff but also king queen plays pretty + + + align:start position:0% +bluff but also king queen plays pretty +well when they do call um I'm always + + align:start position:0% +well when they do call um I'm always + + + align:start position:0% +well when they do call um I'm always +good when I hit Top pair so we make it + + align:start position:0% +good when I hit Top pair so we make it + + + align:start position:0% +good when I hit Top pair so we make it +8,000 but unfortunately this time this + + align:start position:0% +8,000 but unfortunately this time this + + + align:start position:0% +8,000 but unfortunately this time this +Gerard dox goes all in so we basically + + align:start position:0% +Gerard dox goes all in so we basically + + + align:start position:0% +Gerard dox goes all in so we basically +just have to fold and um yeah + + align:start position:0% +just have to fold and um yeah + + + align:start position:0% +just have to fold and um yeah +unfortunately 8,000 is small enough + + align:start position:0% +unfortunately 8,000 is small enough + + + align:start position:0% +unfortunately 8,000 is small enough +where we can just happily get away here + + align:start position:0% +where we can just happily get away here + + + align:start position:0% +where we can just happily get away here +and it actually turns out this guy also + + align:start position:0% +and it actually turns out this guy also + + + align:start position:0% +and it actually turns out this guy also +goes on which makes the decision even + + align:start position:0% +goes on which makes the decision even + + + align:start position:0% +goes on which makes the decision even +easier so yeah it looks like we R do + + align:start position:0% +easier so yeah it looks like we R do + + + align:start position:0% +easier so yeah it looks like we R do +pocket aces and pocket kings that time + + align:start position:0% +pocket aces and pocket kings that time + + + align:start position:0% +pocket aces and pocket kings that time +so doesn't always work when you R raise + + align:start position:0% +so doesn't always work when you R raise + + + align:start position:0% +so doesn't always work when you R raise +with king queen um + + align:start position:0% + + + + align:start position:0% + +all right so still at the same table we + + align:start position:0% +all right so still at the same table we + + + align:start position:0% +all right so still at the same table we +get Ace jack off suit under the gun We R + + align:start position:0% +get Ace jack off suit under the gun We R + + + align:start position:0% +get Ace jack off suit under the gun We R +and this uh jard do guy + + align:start position:0% +and this uh jard do guy + + + align:start position:0% +and this uh jard do guy +calls we flop King n Deuce with two + + align:start position:0% +calls we flop King n Deuce with two + + + align:start position:0% +calls we flop King n Deuce with two +hearts and I think this is sort of + + align:start position:0% +hearts and I think this is sort of + + + align:start position:0% +hearts and I think this is sort of +pretty much the worst swop I one of the + + align:start position:0% +pretty much the worst swop I one of the + + + align:start position:0% +pretty much the worst swop I one of the +worst swops I could get um you know if + + align:start position:0% +worst swops I could get um you know if + + + align:start position:0% +worst swops I could get um you know if +there if there was like two higher cards + + align:start position:0% +there if there was like two higher cards + + + align:start position:0% +there if there was like two higher cards +like a king and a queen I would have a + + align:start position:0% +like a king and a queen I would have a + + + align:start position:0% +like a king and a queen I would have a +gutshot straight draw and if it was all + + align:start position:0% +gutshot straight draw and if it was all + + + align:start position:0% +gutshot straight draw and if it was all +low cards I'd have two over cards but + + align:start position:0% +low cards I'd have two over cards but + + + align:start position:0% +low cards I'd have two over cards but +here there's a flush draw that I have no + + align:start position:0% +here there's a flush draw that I have no + + + align:start position:0% +here there's a flush draw that I have no +part of and also they're somewhat likely + + align:start position:0% +part of and also they're somewhat likely + + + align:start position:0% +part of and also they're somewhat likely +to have a king and if they do I only + + align:start position:0% +to have a king and if they do I only + + + align:start position:0% +to have a king and if they do I only +have three outs in my Aces so I'm just + + align:start position:0% +have three outs in my Aces so I'm just + + + align:start position:0% +have three outs in my Aces so I'm just +going to give this up you know so I + + align:start position:0% +going to give this up you know so I + + + align:start position:0% +going to give this up you know so I +talked about the power of continuation + + align:start position:0% +talked about the power of continuation + + + align:start position:0% +talked about the power of continuation +betting before where continuation + + align:start position:0% +betting before where continuation + + + align:start position:0% +betting before where continuation +betting is good because my range is + + align:start position:0% +betting is good because my range is + + + align:start position:0% +betting is good because my range is +stronger than theirs I can have Aces I + + align:start position:0% +stronger than theirs I can have Aces I + + + align:start position:0% +stronger than theirs I can have Aces I +can Bluff Etc and yeah in general + + align:start position:0% +can Bluff Etc and yeah in general + + + align:start position:0% +can Bluff Etc and yeah in general +continuation betting being aggressive + + align:start position:0% +continuation betting being aggressive + + + align:start position:0% +continuation betting being aggressive +especially when you're you're the pre-f + + align:start position:0% +especially when you're you're the pre-f + + + align:start position:0% +especially when you're you're the pre-f +Flop aggressor is very good but I think + + align:start position:0% +Flop aggressor is very good but I think + + + align:start position:0% +Flop aggressor is very good but I think +this is just one of the worst flops and + + align:start position:0% +this is just one of the worst flops and + + + align:start position:0% +this is just one of the worst flops and +I'm just going to give up um + + align:start position:0% +I'm just going to give up um + + + align:start position:0% +I'm just going to give up um +so I check they bet and I fold um I mean + + align:start position:0% +so I check they bet and I fold um I mean + + + align:start position:0% +so I check they bet and I fold um I mean +I think sometimes I will check a + + align:start position:0% +I think sometimes I will check a + + + align:start position:0% +I think sometimes I will check a +reasonably good hand here to protect the + + align:start position:0% +reasonably good hand here to protect the + + + align:start position:0% +reasonably good hand here to protect the +time so you know so so that they can't + + align:start position:0% +time so you know so so that they can't + + + align:start position:0% +time so you know so so that they can't +just bet here with any two cards and no + + align:start position:0% +just bet here with any two cards and no + + + align:start position:0% +just bet here with any two cards and no +for sure aold but most of the time when + + align:start position:0% +for sure aold but most of the time when + + + align:start position:0% +for sure aold but most of the time when +I'm checking here I'm going to be fairly + + align:start position:0% +I'm checking here I'm going to be fairly + + + align:start position:0% +I'm checking here I'm going to be fairly +weak which is maybe exploitable but I + + align:start position:0% +weak which is maybe exploitable but I + + + align:start position:0% +weak which is maybe exploitable but I +give up the + + align:start position:0% +give up the + + + align:start position:0% +give up the +hand so 85 suited I decided to call on + + align:start position:0% +hand so 85 suited I decided to call on + + + align:start position:0% +hand so 85 suited I decided to call on +the small blind um I know this goes + + align:start position:0% +the small blind um I know this goes + + + align:start position:0% +the small blind um I know this goes +against my recommendation from the first + + align:start position:0% +against my recommendation from the first + + + align:start position:0% +against my recommendation from the first +class I think calling from the small + + align:start position:0% +class I think calling from the small + + + align:start position:0% +class I think calling from the small +blind is actually both theoretically and + + align:start position:0% +blind is actually both theoretically and + + + align:start position:0% +blind is actually both theoretically and +practically a pretty good strategy for a + + align:start position:0% +practically a pretty good strategy for a + + + align:start position:0% +practically a pretty good strategy for a +lot of cases but it's a bit complicated + + align:start position:0% +lot of cases but it's a bit complicated + + + align:start position:0% +lot of cases but it's a bit complicated +because you have to sometimes like you + + align:start position:0% +because you have to sometimes like you + + + align:start position:0% +because you have to sometimes like you +have to sometimes limp Rays as a bluff + + align:start position:0% +have to sometimes limp Rays as a bluff + + + align:start position:0% +have to sometimes limp Rays as a bluff +you have to sometimes limp rays and trap + + align:start position:0% +you have to sometimes limp rays and trap + + + align:start position:0% +you have to sometimes limp rays and trap +with Aces so it's a bit complicated so I + + align:start position:0% +with Aces so it's a bit complicated so I + + + align:start position:0% +with Aces so it's a bit complicated so I +I just said for Simplicity you have to + + align:start position:0% +I just said for Simplicity you have to + + + align:start position:0% +I just said for Simplicity you have to +you should just raise or fold which is + + align:start position:0% +you should just raise or fold which is + + + align:start position:0% +you should just raise or fold which is +still reasonable I think but I decid to + + align:start position:0% +still reasonable I think but I decid to + + + align:start position:0% +still reasonable I think but I decid to +call here and it's + + align:start position:0% +call here and it's + + + align:start position:0% +call here and it's +checked we get a pretty good flop for + + align:start position:0% +checked we get a pretty good flop for + + + align:start position:0% +checked we get a pretty good flop for +our hand but probably a better flop for + + align:start position:0% +our hand but probably a better flop for + + + align:start position:0% +our hand but probably a better flop for +his range because when we call + + align:start position:0% +his range because when we call + + + align:start position:0% +his range because when we call +we're less likely to have really small + + align:start position:0% +we're less likely to have really small + + + align:start position:0% +we're less likely to have really small +cards than he does but I mean we have a + + align:start position:0% +cards than he does but I mean we have a + + + align:start position:0% +cards than he does but I mean we have a +good flop for our hand so I I'm still + + align:start position:0% +good flop for our hand so I I'm still + + + align:start position:0% +good flop for our hand so I I'm still +going to bet my good hands so I bet um I + + align:start position:0% +going to bet my good hands so I bet um I + + + align:start position:0% +going to bet my good hands so I bet um I +bet half pot which is maybe not big + + align:start position:0% +bet half pot which is maybe not big + + + align:start position:0% +bet half pot which is maybe not big +enough to be honest considering how dry + + align:start position:0% +enough to be honest considering how dry + + + align:start position:0% +enough to be honest considering how dry +the board is and we get a call we turn a + + align:start position:0% +the board is and we get a call we turn a + + + align:start position:0% +the board is and we get a call we turn a +nine which is a great + + align:start position:0% +nine which is a great + + + align:start position:0% +nine which is a great +card because um it's it gives not only + + align:start position:0% +card because um it's it gives not only + + + align:start position:0% +card because um it's it gives not only +does it complete our hand there's a lot + + align:start position:0% +does it complete our hand there's a lot + + + align:start position:0% +does it complete our hand there's a lot +of draws out there and I bet quite big + + align:start position:0% +of draws out there and I bet quite big + + + align:start position:0% +of draws out there and I bet quite big +here so this is where I was talking + + align:start position:0% +here so this is where I was talking + + + align:start position:0% +here so this is where I was talking +about if the board is dry you need to + + align:start position:0% +about if the board is dry you need to + + + align:start position:0% +about if the board is dry you need to +bet big and not give your opponent odds + + align:start position:0% +bet big and not give your opponent odds + + + align:start position:0% +bet big and not give your opponent odds +so I bet 688 into + + align:start position:0% +so I bet 688 into + + + align:start position:0% +so I bet 688 into +10800 um the reason for the eights is + + align:start position:0% +10800 um the reason for the eights is + + + align:start position:0% +10800 um the reason for the eights is +because it's easier to type like 6888 + + align:start position:0% +because it's easier to type like 6888 + + + align:start position:0% +because it's easier to type like 6888 +than 6800 so you'll see that quite a lot + + align:start position:0% +than 6800 so you'll see that quite a lot + + + align:start position:0% +than 6800 so you'll see that quite a lot +in + + align:start position:0% +in + + + align:start position:0% +in +um and we get + + align:start position:0% +um and we get + + + align:start position:0% +um and we get +called yeah and another sometimes you + + align:start position:0% +called yeah and another sometimes you + + + align:start position:0% +called yeah and another sometimes you +can get more creative you can do like 1 + + align:start position:0% +can get more creative you can do like 1 + + + align:start position:0% +can get more creative you can do like 1 +2 3 4 5 6 7 that's like a popular bet + + align:start position:0% +2 3 4 5 6 7 that's like a popular bet + + + align:start position:0% +2 3 4 5 6 7 that's like a popular bet +because you can just slide your finger + + align:start position:0% +because you can just slide your finger + + + align:start position:0% +because you can just slide your finger +across the keyboard um yeah there's a + + align:start position:0% +across the keyboard um yeah there's a + + + align:start position:0% +across the keyboard um yeah there's a +lot of weird idiots in Innes but okay so + + align:start position:0% +lot of weird idiots in Innes but okay so + + + align:start position:0% +lot of weird idiots in Innes but okay so +I bet + + align:start position:0% +I bet + + + align:start position:0% +I bet +15555 here and um he folds and yeah so I + + align:start position:0% +15555 here and um he folds and yeah so I + + + align:start position:0% +15555 here and um he folds and yeah so I +mean I'm playing I'm playing like this + + align:start position:0% +mean I'm playing I'm playing like this + + + align:start position:0% +mean I'm playing I'm playing like this +with my missed Spade draws my missed + + align:start position:0% +with my missed Spade draws my missed + + + align:start position:0% +with my missed Spade draws my missed +heart draws and unfortunately we don't + + align:start position:0% +heart draws and unfortunately we don't + + + align:start position:0% +heart draws and unfortunately we don't +get paid + + align:start position:0% + + + + align:start position:0% + +off okay so Jack eight suited here the + + align:start position:0% +off okay so Jack eight suited here the + + + align:start position:0% +off okay so Jack eight suited here the +small blind raises definitely I'm going + + align:start position:0% +small blind raises definitely I'm going + + + align:start position:0% +small blind raises definitely I'm going +to + + align:start position:0% +to + + + align:start position:0% +to +cough and we flop top pair they bet and + + align:start position:0% +cough and we flop top pair they bet and + + + align:start position:0% +cough and we flop top pair they bet and +so I think this is so this is spot where + + align:start position:0% +so I think this is so this is spot where + + + align:start position:0% +so I think this is so this is spot where +you know I think my hand is there's + + align:start position:0% +you know I think my hand is there's + + + align:start position:0% +you know I think my hand is there's +benefits of raising and benefits of + + align:start position:0% +benefits of raising and benefits of + + + align:start position:0% +benefits of raising and benefits of +calling and overall I decided the + + align:start position:0% +calling and overall I decided the + + + align:start position:0% +calling and overall I decided the +benefits of raising were higher so I + + align:start position:0% +benefits of raising were higher so I + + + align:start position:0% +benefits of raising were higher so I +decided to raise and just get it all in + + align:start position:0% +decided to raise and just get it all in + + + align:start position:0% +decided to raise and just get it all in +although I think calling is not + + align:start position:0% +although I think calling is not + + + align:start position:0% +although I think calling is not +unreasonable because your hand sort of + + align:start position:0% +unreasonable because your hand sort of + + + align:start position:0% +unreasonable because your hand sort of +isn't good enough where you're just like + + align:start position:0% +isn't good enough where you're just like + + + align:start position:0% +isn't good enough where you're just like +really really happy to get it all in I + + align:start position:0% +really really happy to get it all in I + + + align:start position:0% +really really happy to get it all in I +mean it's good enough where I'm going to + + align:start position:0% +mean it's good enough where I'm going to + + + align:start position:0% +mean it's good enough where I'm going to +get it all in but I'm not like thrilled + + align:start position:0% +get it all in but I'm not like thrilled + + + align:start position:0% +get it all in but I'm not like thrilled +if they go all in and I have to call so + + align:start position:0% +if they go all in and I have to call so + + + align:start position:0% +if they go all in and I have to call so +that's one disadvantage of getting it + + align:start position:0% +that's one disadvantage of getting it + + + align:start position:0% +that's one disadvantage of getting it +all in but I just think compared to the + + align:start position:0% +all in but I just think compared to the + + + align:start position:0% +all in but I just think compared to the +advantage of you know not giving them a + + align:start position:0% +advantage of you know not giving them a + + + align:start position:0% +advantage of you know not giving them a +chance to to suuck out on me and beat me + + align:start position:0% +chance to to suuck out on me and beat me + + + align:start position:0% +chance to to suuck out on me and beat me +in the hand is a pretty big Advantage + + align:start position:0% +in the hand is a pretty big Advantage + + + align:start position:0% +in the hand is a pretty big Advantage +you know not letting a queen king or Ace + + align:start position:0% +you know not letting a queen king or Ace + + + align:start position:0% +you know not letting a queen king or Ace +roll off um another advantage of calling + + align:start position:0% +roll off um another advantage of calling + + + align:start position:0% +roll off um another advantage of calling +is being would to pick off Bluffs but I + + align:start position:0% +is being would to pick off Bluffs but I + + + align:start position:0% +is being would to pick off Bluffs but I +just think in this flop I want to play a + + align:start position:0% +just think in this flop I want to play a + + + align:start position:0% +just think in this flop I want to play a +strategy where I'm going to raise to a + + align:start position:0% +strategy where I'm going to raise to a + + + align:start position:0% +strategy where I'm going to raise to a +small size and put him to the decision + + align:start position:0% +small size and put him to the decision + + + align:start position:0% +small size and put him to the decision +both with my top pairs like Jack and + + align:start position:0% +both with my top pairs like Jack and + + + align:start position:0% +both with my top pairs like Jack and +also my hands like 79 or whatever so I + + align:start position:0% +also my hands like 79 or whatever so I + + + align:start position:0% +also my hands like 79 or whatever so I +decided to raise but I think calling + + align:start position:0% +decided to raise but I think calling + + + align:start position:0% +decided to raise but I think calling +would have been fun and if + + align:start position:0% + + + + align:start position:0% + +the next hand we have Ace King all right + + align:start position:0% +the next hand we have Ace King all right + + + align:start position:0% +the next hand we have Ace King all right +so we got like seven more hands yeah so + + align:start position:0% +so we got like seven more hands yeah so + + + align:start position:0% +so we got like seven more hands yeah so +I'll I'll go a bit quickly near the end + + align:start position:0% +I'll I'll go a bit quickly near the end + + + align:start position:0% +I'll I'll go a bit quickly near the end +but I think we'll get through all the + + align:start position:0% +but I think we'll get through all the + + + align:start position:0% +but I think we'll get through all the +hands uh this hand is fairly easy they + + align:start position:0% +hands uh this hand is fairly easy they + + + align:start position:0% +hands uh this hand is fairly easy they +they make it 5,000 and we have Ace King + + align:start position:0% +they make it 5,000 and we have Ace King + + + align:start position:0% +they make it 5,000 and we have Ace King +and we just go all in there's no point + + align:start position:0% +and we just go all in there's no point + + + align:start position:0% +and we just go all in there's no point +slow playing essentially um especially + + align:start position:0% +slow playing essentially um especially + + + align:start position:0% +slow playing essentially um especially +when you know if they have Jack 10 they + + align:start position:0% +when you know if they have Jack 10 they + + + align:start position:0% +when you know if they have Jack 10 they +have lots of outs so we go on and they + + align:start position:0% +have lots of outs so we go on and they + + + align:start position:0% +have lots of outs so we go on and they +fold so it is a bit curious here because + + align:start position:0% +fold so it is a bit curious here because + + + align:start position:0% +fold so it is a bit curious here because +they actually only had 12 big blinds + + align:start position:0% +they actually only had 12 big blinds + + + align:start position:0% +they actually only had 12 big blinds +here so they could have just went all in + + align:start position:0% +here so they could have just went all in + + + align:start position:0% +here so they could have just went all in +self but they decided to raise small so + + align:start position:0% +self but they decided to raise small so + + + align:start position:0% +self but they decided to raise small so +that they could fold if someone behind + + align:start position:0% +that they could fold if someone behind + + + align:start position:0% +that they could fold if someone behind +picks up a monster and I guess they were + + align:start position:0% +picks up a monster and I guess they were + + + align:start position:0% +picks up a monster and I guess they were +paid off this time + + align:start position:0% + + + + align:start position:0% + +um but yeah like for this hand like one + + align:start position:0% +um but yeah like for this hand like one + + + align:start position:0% +um but yeah like for this hand like one +disadvantage of their play right like + + align:start position:0% +disadvantage of their play right like + + + align:start position:0% +disadvantage of their play right like +suppose we had King 2 suited we would + + align:start position:0% +suppose we had King 2 suited we would + + + align:start position:0% +suppose we had King 2 suited we would +have folded if they went all in but now + + align:start position:0% +have folded if they went all in but now + + + align:start position:0% +have folded if they went all in but now +we can call and see a flop so but but + + align:start position:0% +we can call and see a flop so but but + + + align:start position:0% +we can call and see a flop so but but +for because we had Ace King then I guess + + align:start position:0% +for because we had Ace King then I guess + + + align:start position:0% +for because we had Ace King then I guess +they profited from not committing their + + align:start position:0% +they profited from not committing their + + + align:start position:0% +they profited from not committing their +whole + + align:start position:0% +whole + + + align:start position:0% +whole +stack okay we have King Jack offit we + + align:start position:0% +stack okay we have King Jack offit we + + + align:start position:0% +stack okay we have King Jack offit we +make it 6,000 and this guy goes all in I + + align:start position:0% +make it 6,000 and this guy goes all in I + + + align:start position:0% +make it 6,000 and this guy goes all in I +I fold here I think it's not that close + + align:start position:0% +I fold here I think it's not that close + + + align:start position:0% +I fold here I think it's not that close +I think with King Jack suited it's close + + align:start position:0% +I think with King Jack suited it's close + + + align:start position:0% +I think with King Jack suited it's close +but I'd still fold with King Jack suited + + align:start position:0% +but I'd still fold with King Jack suited + + + align:start position:0% +but I'd still fold with King Jack suited +I'd probably call with Ace jack off suit + + align:start position:0% +I'd probably call with Ace jack off suit + + + align:start position:0% +I'd probably call with Ace jack off suit +plus I would probably call with Ace 10 + + align:start position:0% +plus I would probably call with Ace 10 + + + align:start position:0% +plus I would probably call with Ace 10 +suited and I'd call with king queen + + align:start position:0% +suited and I'd call with king queen + + + align:start position:0% +suited and I'd call with king queen +suited and probably king queen off suit + + align:start position:0% +suited and probably king queen off suit + + + align:start position:0% +suited and probably king queen off suit +as well um in this case so in the last + + align:start position:0% +as well um in this case so in the last + + + align:start position:0% +as well um in this case so in the last +class I said being suited is very + + align:start position:0% +class I said being suited is very + + + align:start position:0% +class I said being suited is very +important when you're behind but when + + align:start position:0% +important when you're behind but when + + + align:start position:0% +important when you're behind but when +you're potentially ahead just having a + + align:start position:0% +you're potentially ahead just having a + + + align:start position:0% +you're potentially ahead just having a +slightly better hand is very important + + align:start position:0% +slightly better hand is very important + + + align:start position:0% +slightly better hand is very important +so I think in this situation I would + + align:start position:0% +so I think in this situation I would + + + align:start position:0% +so I think in this situation I would +fold King Jack suited but call with king + + align:start position:0% +fold King Jack suited but call with king + + + align:start position:0% +fold King Jack suited but call with king +queen off suit because a decent part of + + align:start position:0% +queen off suit because a decent part of + + + align:start position:0% +queen off suit because a decent part of +his range is hands like King Jack and + + align:start position:0% +his range is hands like King Jack and + + + align:start position:0% +his range is hands like King Jack and +king queen + + align:start position:0% + + + + align:start position:0% + +so okay here I have king queen and + + align:start position:0% +so okay here I have king queen and + + + align:start position:0% +so okay here I have king queen and +degenerated so I for some reason I love + + align:start position:0% +degenerated so I for some reason I love + + + align:start position:0% +degenerated so I for some reason I love +making this play with king queen um it's + + align:start position:0% +making this play with king queen um it's + + + align:start position:0% +making this play with king queen um it's +actually not that unfounded is just a + + align:start position:0% +actually not that unfounded is just a + + + align:start position:0% +actually not that unfounded is just a +good hand to Bluff with that at the same + + align:start position:0% +good hand to Bluff with that at the same + + + align:start position:0% +good hand to Bluff with that at the same +time sort of protects your range in the + + align:start position:0% +time sort of protects your range in the + + + align:start position:0% +time sort of protects your range in the +case that he calls and also your hand + + align:start position:0% +case that he calls and also your hand + + + align:start position:0% +case that he calls and also your hand +doesn't play that well if you just call + + align:start position:0% +doesn't play that well if you just call + + + align:start position:0% +doesn't play that well if you just call +because you're not suited so it's it it + + align:start position:0% +because you're not suited so it's it it + + + align:start position:0% +because you're not suited so it's it it +really is King I mean in this tournament + + align:start position:0% +really is King I mean in this tournament + + + align:start position:0% +really is King I mean in this tournament +we've happened to got we've happened to + + align:start position:0% +we've happened to got we've happened to + + + align:start position:0% +we've happened to got we've happened to +been dealt king queen a lot and gotone + + align:start position:0% +been dealt king queen a lot and gotone + + + align:start position:0% +been dealt king queen a lot and gotone +into situations where we can uh re ra + + align:start position:0% +into situations where we can uh re ra + + + align:start position:0% +into situations where we can uh re ra +Bluff people but it really is my + + align:start position:0% +Bluff people but it really is my + + + align:start position:0% +Bluff people but it really is my +favorite hand to do this with so it + + align:start position:0% +favorite hand to do this with so it + + + align:start position:0% +favorite hand to do this with so it +might be even be too predictable because + + align:start position:0% +might be even be too predictable because + + + align:start position:0% +might be even be too predictable because +I just always have king and queen + + align:start position:0% +I just always have king and queen + + + align:start position:0% +I just always have king and queen +whenever I do this um but we do take it + + align:start position:0% +whenever I do this um but we do take it + + + align:start position:0% +whenever I do this um but we do take it +down + + align:start position:0% + + + + align:start position:0% + +here okay Ace jack off suit this guy so + + align:start position:0% +here okay Ace jack off suit this guy so + + + align:start position:0% +here okay Ace jack off suit this guy so +this degenerated guy who we just re at + + align:start position:0% +this degenerated guy who we just re at + + + align:start position:0% +this degenerated guy who we just re at +this point it's probably late enough in + + align:start position:0% +this point it's probably late enough in + + + align:start position:0% +this point it's probably late enough in +the tournament I am paying attention and + + align:start position:0% +the tournament I am paying attention and + + + align:start position:0% +the tournament I am paying attention and +I am aware that I just R raised this guy + + align:start position:0% +I am aware that I just R raised this guy + + + align:start position:0% +I am aware that I just R raised this guy +three hands earlier so they they make a + + align:start position:0% +three hands earlier so they they make a + + + align:start position:0% +three hands earlier so they they make a +big raise here to 9,000 and I call with + + align:start position:0% +big raise here to 9,000 and I call with + + + align:start position:0% +big raise here to 9,000 and I call with +a jack which I regret quite a bit I + + align:start position:0% +a jack which I regret quite a bit I + + + align:start position:0% +a jack which I regret quite a bit I +think it's just I think it's just too + + align:start position:0% +think it's just I think it's just too + + + align:start position:0% +think it's just I think it's just too +weak a hand to play and if I'm going to + + align:start position:0% +weak a hand to play and if I'm going to + + + align:start position:0% +weak a hand to play and if I'm going to +play it I think I should just go all in + + align:start position:0% +play it I think I should just go all in + + + align:start position:0% +play it I think I should just go all in +and try to win the hand pre flop this is + + align:start position:0% +and try to win the hand pre flop this is + + + align:start position:0% +and try to win the hand pre flop this is +even though I'm in position I think it's + + align:start position:0% +even though I'm in position I think it's + + + align:start position:0% +even though I'm in position I think it's +just going to be hard to play um you + + align:start position:0% +just going to be hard to play um you + + + align:start position:0% +just going to be hard to play um you +know even when I hit an ace or a Jack + + align:start position:0% +know even when I hit an ace or a Jack + + + align:start position:0% +know even when I hit an ace or a Jack +I'm still G to quite often be behind and + + align:start position:0% +I'm still G to quite often be behind and + + + align:start position:0% +I'm still G to quite often be behind and +if I don't hit an aceer a jack I'm + + align:start position:0% +if I don't hit an aceer a jack I'm + + + align:start position:0% +if I don't hit an aceer a jack I'm +pretty much always just going to have to + + align:start position:0% +pretty much always just going to have to + + + align:start position:0% +pretty much always just going to have to +fold and that's basically what happens + + align:start position:0% +fold and that's basically what happens + + + align:start position:0% +fold and that's basically what happens +so I don't know why I just gave away + + align:start position:0% +so I don't know why I just gave away + + + align:start position:0% +so I don't know why I just gave away +9,000 chips there + + align:start position:0% +9,000 chips there + + + align:start position:0% +9,000 chips there +but okay so Queen Jack + + align:start position:0% +but okay so Queen Jack + + + align:start position:0% +but okay so Queen Jack +suited I just go all in from the small + + align:start position:0% +suited I just go all in from the small + + + align:start position:0% +suited I just go all in from the small +blind because it's so even though we + + align:start position:0% +blind because it's so even though we + + + align:start position:0% +blind because it's so even though we +have 15 big blinds which is more than 12 + + align:start position:0% +have 15 big blinds which is more than 12 + + + align:start position:0% +have 15 big blinds which is more than 12 +I said last class that from the small + + align:start position:0% +I said last class that from the small + + + align:start position:0% +I said last class that from the small +blind you're really really really + + align:start position:0% +blind you're really really really + + + align:start position:0% +blind you're really really really +incentivized to go all in because if you + + align:start position:0% +incentivized to go all in because if you + + + align:start position:0% +incentivized to go all in because if you +don't then the other guy has position + + align:start position:0% +don't then the other guy has position + + + align:start position:0% +don't then the other guy has position +whereas like from the button if you just + + align:start position:0% +whereas like from the button if you just + + + align:start position:0% +whereas like from the button if you just +raise the big blind calls you have + + align:start position:0% +raise the big blind calls you have + + + align:start position:0% +raise the big blind calls you have +position so I go all in Queen Jack + + align:start position:0% +position so I go all in Queen Jack + + + align:start position:0% +position so I go all in Queen Jack +suited is more than good enough and we + + align:start position:0% +suited is more than good enough and we + + + align:start position:0% +suited is more than good enough and we +get a + + align:start position:0% + + + + align:start position:0% + +fold and the next hand okay so this is + + align:start position:0% +fold and the next hand okay so this is + + + align:start position:0% +fold and the next hand okay so this is +actually great illustration the very + + align:start position:0% +actually great illustration the very + + + align:start position:0% +actually great illustration the very +next hand we get Queen jack off and we + + align:start position:0% +next hand we get Queen jack off and we + + + align:start position:0% +next hand we get Queen jack off and we +just raise from this button and it's + + align:start position:0% +just raise from this button and it's + + + align:start position:0% +just raise from this button and it's +exactly the reason I said because we + + align:start position:0% +exactly the reason I said because we + + + align:start position:0% +exactly the reason I said because we +have position so we don't mind if the + + align:start position:0% +have position so we don't mind if the + + + align:start position:0% +have position so we don't mind if the +pot gets played post fly + + align:start position:0% +pot gets played post fly + + + align:start position:0% +pot gets played post fly +so the small blind goes all in and note + + align:start position:0% +so the small blind goes all in and note + + + align:start position:0% +so the small blind goes all in and note +note that they're actually fairly short + + align:start position:0% +note that they're actually fairly short + + + align:start position:0% +note that they're actually fairly short +here they only have 14 big blinds to + + align:start position:0% +here they only have 14 big blinds to + + + align:start position:0% +here they only have 14 big blinds to +start the hand so I I would have easily + + align:start position:0% +start the hand so I I would have easily + + + align:start position:0% +start the hand so I I would have easily +called with Queen Jack suited even with + + align:start position:0% +called with Queen Jack suited even with + + + align:start position:0% +called with Queen Jack suited even with +Queen jack off I'm not certain that + + align:start position:0% +Queen jack off I'm not certain that + + + align:start position:0% +Queen jack off I'm not certain that +folding is a better play than calling + + align:start position:0% +folding is a better play than calling + + + align:start position:0% +folding is a better play than calling +it's just your odds are basically good + + align:start position:0% +it's just your odds are basically good + + + align:start position:0% +it's just your odds are basically good +enough here and their range will be + + align:start position:0% +enough here and their range will be + + + align:start position:0% +enough here and their range will be +fairly loose when I raise from the + + align:start position:0% +fairly loose when I raise from the + + + align:start position:0% +fairly loose when I raise from the +button because they're going to think I + + align:start position:0% +button because they're going to think I + + + align:start position:0% +button because they're going to think I +don't have much when I raise from the + + align:start position:0% +don't have much when I raise from the + + + align:start position:0% +don't have much when I raise from the +button so it's quite possible calling + + align:start position:0% +button so it's quite possible calling + + + align:start position:0% +button so it's quite possible calling +here would have in the right play it's + + align:start position:0% +here would have in the right play it's + + + align:start position:0% +here would have in the right play it's +very close I think I would have + + align:start position:0% +very close I think I would have + + + align:start position:0% +very close I think I would have +definitely called with ECE 9 offit I + + align:start position:0% +definitely called with ECE 9 offit I + + + align:start position:0% +definitely called with ECE 9 offit I +would have definitely called with King + + align:start position:0% +would have definitely called with King + + + align:start position:0% +would have definitely called with King +10 offit um yeah it's pretty close I + + align:start position:0% +10 offit um yeah it's pretty close I + + + align:start position:0% +10 offit um yeah it's pretty close I +decided to fold maybe I also knew that + + align:start position:0% +decided to fold maybe I also knew that + + + align:start position:0% +decided to fold maybe I also knew that +they were kind of tight um normally when + + align:start position:0% +they were kind of tight um normally when + + + align:start position:0% +they were kind of tight um normally when +I play but I'm not showing here is I + + align:start position:0% +I play but I'm not showing here is I + + + align:start position:0% +I play but I'm not showing here is I +have like statistics on every player of + + align:start position:0% +have like statistics on every player of + + + align:start position:0% +have like statistics on every player of +like overall the hands what percent of + + align:start position:0% +like overall the hands what percent of + + + align:start position:0% +like overall the hands what percent of +the time they raise what percent they + + align:start position:0% +the time they raise what percent they + + + align:start position:0% +the time they raise what percent they +folded so I have a rough idea while I'm + + align:start position:0% +folded so I have a rough idea while I'm + + + align:start position:0% +folded so I have a rough idea while I'm +playing um of how tight everyone is and + + align:start position:0% +playing um of how tight everyone is and + + + align:start position:0% +playing um of how tight everyone is and +maybe I just knew he was tight actually + + align:start position:0% +maybe I just knew he was tight actually + + + align:start position:0% +maybe I just knew he was tight actually +let me see if I can turn it back on here + + align:start position:0% +let me see if I can turn it back on here + + + align:start position:0% +let me see if I can turn it back on here +yeah let me see that might be + + align:start position:0% +yeah let me see that might be + + + align:start position:0% +yeah let me see that might be +why uh so so at this okay so these + + align:start position:0% +why uh so so at this okay so these + + + align:start position:0% +why uh so so at this okay so these +numbers actually he's fairly loose yeah + + align:start position:0% +numbers actually he's fairly loose yeah + + + align:start position:0% +numbers actually he's fairly loose yeah +I actually I'm not sure why it folded so + + align:start position:0% +I actually I'm not sure why it folded so + + + align:start position:0% +I actually I'm not sure why it folded so +this 10.7 is his re ra percentage and + + align:start position:0% +this 10.7 is his re ra percentage and + + + align:start position:0% +this 10.7 is his re ra percentage and +what this says is 10.7% of the time he + + align:start position:0% +what this says is 10.7% of the time he + + + align:start position:0% +what this says is 10.7% of the time he +could have reraised he reraised it's + + align:start position:0% +could have reraised he reraised it's + + + align:start position:0% +could have reraised he reraised it's +only over a sample of 187 hands but it's + + align:start position:0% +only over a sample of 187 hands but it's + + + align:start position:0% +only over a sample of 187 hands but it's +it's all yeah I think it's definitely + + align:start position:0% +it's all yeah I think it's definitely + + + align:start position:0% +it's all yeah I think it's definitely +looser than average um although it's a + + align:start position:0% +looser than average um although it's a + + + align:start position:0% +looser than average um although it's a +bit biased because we're playing at a + + align:start position:0% +bit biased because we're playing at a + + + align:start position:0% +bit biased because we're playing at a +5-h handed table um nonetheless it's + + align:start position:0% +5-h handed table um nonetheless it's + + + align:start position:0% +5-h handed table um nonetheless it's +close I think calling probably would + + align:start position:0% +close I think calling probably would + + + align:start position:0% +close I think calling probably would +have been okay but I folded let me turn + + align:start position:0% +have been okay but I folded let me turn + + + align:start position:0% +have been okay but I folded let me turn +this off it's quite annoying + + align:start position:0% +this off it's quite annoying + + + align:start position:0% +this off it's quite annoying +um okay so so this is near the final + + align:start position:0% +um okay so so this is near the final + + + align:start position:0% +um okay so so this is near the final +table now this is I think the second + + align:start position:0% +table now this is I think the second + + + align:start position:0% +table now this is I think the second +Final Table there's maybe like 11 or 12 + + align:start position:0% +Final Table there's maybe like 11 or 12 + + + align:start position:0% +Final Table there's maybe like 11 or 12 +left and I'm just going to show you the + + align:start position:0% +left and I'm just going to show you the + + + align:start position:0% +left and I'm just going to show you the +final hands before the final table so + + align:start position:0% +final hands before the final table so + + + align:start position:0% +final hands before the final table so +this hand is a no-brainer we go all in + + align:start position:0% +this hand is a no-brainer we go all in + + + align:start position:0% +this hand is a no-brainer we go all in +and fortunately we hold against pocket + + align:start position:0% +and fortunately we hold against pocket + + + align:start position:0% +and fortunately we hold against pocket +twos so um okay so the the very last + + align:start position:0% +twos so um okay so the the very last + + + align:start position:0% +twos so um okay so the the very last +hand uh + + align:start position:0% +hand uh + + + align:start position:0% +hand uh +also fairly no-brainer this guy goes all + + align:start position:0% +also fairly no-brainer this guy goes all + + + align:start position:0% +also fairly no-brainer this guy goes all +in so yeah poker is easy if you just get + + align:start position:0% +in so yeah poker is easy if you just get + + + align:start position:0% +in so yeah poker is easy if you just get +dealt pocket Jacks pocket pces all the + + align:start position:0% +dealt pocket Jacks pocket pces all the + + + align:start position:0% +dealt pocket Jacks pocket pces all the +time um so we win this one okay so this + + align:start position:0% +time um so we win this one okay so this + + + align:start position:0% +time um so we win this one okay so this +is the last hand before the final table + + align:start position:0% +is the last hand before the final table + + + align:start position:0% +is the last hand before the final table +so in a future class not the Friday + + align:start position:0% +so in a future class not the Friday + + + align:start position:0% +so in a future class not the Friday +class because Jennifer shahade is + + align:start position:0% +class because Jennifer shahade is + + + align:start position:0% +class because Jennifer shahade is +speaking but uh in a future class I'll + + align:start position:0% +speaking but uh in a future class I'll + + + align:start position:0% +speaking but uh in a future class I'll +go through the final table and I'll + + align:start position:0% +go through the final table and I'll + + + align:start position:0% +go through the final table and I'll +maybe also go through all the hands not + + align:start position:0% +maybe also go through all the hands not + + + align:start position:0% +maybe also go through all the hands not +just the hands where I got in a big pot + + align:start position:0% +just the hands where I got in a big pot + + + align:start position:0% +just the hands where I got in a big pot +so um let me just quickly go back to the + + align:start position:0% +so um let me just quickly go back to the + + + align:start position:0% +so um let me just quickly go back to the +slides + + align:start position:0% +slides + + + align:start position:0% +slides +right so so I really only talked about + + align:start position:0% +right so so I really only talked about + + + align:start position:0% +right so so I really only talked about +two concepts in this class it was this + + align:start position:0% +two concepts in this class it was this + + + align:start position:0% +two concepts in this class it was this +draw draw you versus dry boards so try + + align:start position:0% +draw draw you versus dry boards so try + + + align:start position:0% +draw draw you versus dry boards so try +to remember that while you guys are + + align:start position:0% +to remember that while you guys are + + + align:start position:0% +to remember that while you guys are +playing the changing your bet sizing + + align:start position:0% +playing the changing your bet sizing + + + align:start position:0% +playing the changing your bet sizing +depending on the board texture and also + + align:start position:0% +depending on the board texture and also + + + align:start position:0% +depending on the board texture and also +this pre flop re raising strategy even + + align:start position:0% +this pre flop re raising strategy even + + + align:start position:0% +this pre flop re raising strategy even +though I didn't give you a conclusion + + align:start position:0% +though I didn't give you a conclusion + + + align:start position:0% +though I didn't give you a conclusion +here on what to re ra with um I sort of + + align:start position:0% +here on what to re ra with um I sort of + + + align:start position:0% +here on what to re ra with um I sort of +gave you some rough guidelines and the + + align:start position:0% +gave you some rough guidelines and the + + + align:start position:0% +gave you some rough guidelines and the +advantages and disadvantages of each + + align:start position:0% +advantages and disadvantages of each + + + align:start position:0% +advantages and disadvantages of each +play and yeah Okay cool so that's it uh + + align:start position:0% +play and yeah Okay cool so that's it uh + + + align:start position:0% +play and yeah Okay cool so that's it uh +on Friday's class it should be should be + + align:start position:0% +on Friday's class it should be should be + + + align:start position:0% +on Friday's class it should be should be +really exciting Jennifer Shah she'll + + align:start position:0% +really exciting Jennifer Shah she'll + + + align:start position:0% +really exciting Jennifer Shah she'll +probably talk a bit about Chess as well + + align:start position:0% +probably talk a bit about Chess as well + + + align:start position:0% +probably talk a bit about Chess as well +but I'll convince her not to talk too + + align:start position:0% +but I'll convince her not to talk too + + + align:start position:0% +but I'll convince her not to talk too +much about Chess when it's a poker class + + align:start position:0% +much about Chess when it's a poker class + + + align:start position:0% +much about Chess when it's a poker class +but um thanks + + align:start position:0% + + + + align:start position:0% + +guys \ No newline at end of file diff --git a/_OZXEb8FxZQ.txt b/_OZXEb8FxZQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..196b4afc404b377487dc044bf9c229e720447f31 --- /dev/null +++ b/_OZXEb8FxZQ.txt @@ -0,0 +1,3219 @@ +align:start position:0% + +all right good morning and welcome to + + align:start position:0% +all right good morning and welcome to + + + align:start position:0% +all right good morning and welcome to +806 let's begin uh our subject in + + align:start position:0% +806 let's begin uh our subject in + + + align:start position:0% +806 let's begin uh our subject in +806 has to do with applications of + + align:start position:0% +806 has to do with applications of + + + align:start position:0% +806 has to do with applications of +quantum mechanics and using quantum + + align:start position:0% +quantum mechanics and using quantum + + + align:start position:0% +quantum mechanics and using quantum +mechanics to understand complex systems + + align:start position:0% +mechanics to understand complex systems + + + align:start position:0% +mechanics to understand complex systems +in in fact systems more complex than the + + align:start position:0% +in in fact systems more complex than the + + + align:start position:0% +in in fact systems more complex than the +ones you've understood before for + + align:start position:0% +ones you've understood before for + + + align:start position:0% +ones you've understood before for +example in the previous courses you've + + align:start position:0% +example in the previous courses you've + + + align:start position:0% +example in the previous courses you've +understood very well the simple harmonic + + align:start position:0% +understood very well the simple harmonic + + + align:start position:0% +understood very well the simple harmonic +oscillator you've solv for the + + align:start position:0% +oscillator you've solv for the + + + align:start position:0% +oscillator you've solv for the +hamiltonian you found all the aen states + + align:start position:0% +hamiltonian you found all the aen states + + + align:start position:0% +hamiltonian you found all the aen states +you found all the energies you know + + align:start position:0% +you found all the energies you know + + + align:start position:0% +you found all the energies you know +about the Spectrum you can do time + + align:start position:0% +about the Spectrum you can do time + + + align:start position:0% +about the Spectrum you can do time +evolution in the harmonic oscillator + + align:start position:0% +evolution in the harmonic oscillator + + + align:start position:0% +evolution in the harmonic oscillator +you've discussed even peculiar States + + align:start position:0% +you've discussed even peculiar States + + + align:start position:0% +you've discussed even peculiar States +like coherent States squeeze States you + + align:start position:0% +like coherent States squeeze States you + + + align:start position:0% +like coherent States squeeze States you +know a lot about this very simple + + align:start position:0% +know a lot about this very simple + + + align:start position:0% +know a lot about this very simple +hamiltonian you've also studied the + + align:start position:0% +hamiltonian you've also studied the + + + align:start position:0% +hamiltonian you've also studied the +hydrogen atom hamiltonian and you found + + align:start position:0% +hydrogen atom hamiltonian and you found + + + align:start position:0% +hydrogen atom hamiltonian and you found +the spectrum of the hydrogen atom with + + align:start position:0% +the spectrum of the hydrogen atom with + + + align:start position:0% +the spectrum of the hydrogen atom with +all the degeneracies that it has and + + align:start position:0% +all the degeneracies that it has and + + + align:start position:0% +all the degeneracies that it has and +understood some of those wave functions + + align:start position:0% +understood some of those wave functions + + + align:start position:0% +understood some of those wave functions +and the properties and those are exact + + align:start position:0% +and the properties and those are exact + + + align:start position:0% +and the properties and those are exact +systems but it turns out that in + + align:start position:0% +systems but it turns out that in + + + align:start position:0% +systems but it turns out that in +practice while those exact systems form + + align:start position:0% +practice while those exact systems form + + + align:start position:0% +practice while those exact systems form +the foundation of what you + + align:start position:0% +the foundation of what you + + + align:start position:0% +the foundation of what you +learn many systems and most of the + + align:start position:0% +learn many systems and most of the + + + align:start position:0% +learn many systems and most of the +systems you face in real life and in + + align:start position:0% +systems you face in real life and in + + + align:start position:0% +systems you face in real life and in +research are systems that are more + + align:start position:0% +research are systems that are more + + + align:start position:0% +research are systems that are more +complicated but at least a large + + align:start position:0% +complicated but at least a large + + + align:start position:0% +complicated but at least a large +fraction of them have a Saving Grace + + align:start position:0% +fraction of them have a Saving Grace + + + align:start position:0% +fraction of them have a Saving Grace +they can be thought as that simple + + align:start position:0% +they can be thought as that simple + + + align:start position:0% +they can be thought as that simple +hamiltonian that you understand very + + align:start position:0% +hamiltonian that you understand very + + + align:start position:0% +hamiltonian that you understand very +well plus an extra term or an extra + + align:start position:0% +well plus an extra term or an extra + + + align:start position:0% +well plus an extra term or an extra +effect some sort of a your total + + align:start position:0% +effect some sort of a your total + + + align:start position:0% +effect some sort of a your total +hamiltonian being + + align:start position:0% + + + + align:start position:0% + +essentially the simple hamiltonian but + + align:start position:0% +essentially the simple hamiltonian but + + + align:start position:0% +essentially the simple hamiltonian but +differs from it by some + + align:start position:0% +differs from it by some + + + align:start position:0% +differs from it by some +amount that makes it a little different + + align:start position:0% +amount that makes it a little different + + + align:start position:0% +amount that makes it a little different +so your simple hamiltonian therefore can + + align:start position:0% +so your simple hamiltonian therefore can + + + align:start position:0% +so your simple hamiltonian therefore can +be the harmonic oscillator and in that + + align:start position:0% +be the harmonic oscillator and in that + + + align:start position:0% +be the harmonic oscillator and in that +case for example in general you may have + + align:start position:0% +case for example in general you may have + + + align:start position:0% +case for example in general you may have +a potential for a particle and you know + + align:start position:0% +a potential for a particle and you know + + + align:start position:0% +a potential for a particle and you know +near the minimum of the potential the + + align:start position:0% +near the minimum of the potential the + + + align:start position:0% +near the minimum of the potential the +potential is roughly quadratic in + + align:start position:0% +potential is roughly quadratic in + + + align:start position:0% +potential is roughly quadratic in +general but then as a tailor expansion + + align:start position:0% +general but then as a tailor expansion + + + align:start position:0% +general but then as a tailor expansion +around the minimum you'll find a + + align:start position:0% +around the minimum you'll find a + + + align:start position:0% +around the minimum you'll find a +quadratic term no linear term because + + align:start position:0% +quadratic term no linear term because + + + align:start position:0% +quadratic term no linear term because +it's a minimum a quadratic term and then + + align:start position:0% +it's a minimum a quadratic term and then + + + align:start position:0% +it's a minimum a quadratic term and then +you will find maybe a cubic or a quartic + + align:start position:0% +you will find maybe a cubic or a quartic + + + align:start position:0% +you will find maybe a cubic or a quartic +term and the oscillations are a little + + align:start position:0% + + + + align:start position:0% + +this is studied by people that look at + + align:start position:0% +this is studied by people that look at + + + align:start position:0% +this is studied by people that look at +diatomic molecules the vibrations have + + align:start position:0% +diatomic molecules the vibrations have + + + align:start position:0% +diatomic molecules the vibrations have +this effect it's experimentally + + align:start position:0% +this effect it's experimentally + + + align:start position:0% +this effect it's experimentally +detectable you can have the hydrogen + + align:start position:0% +detectable you can have the hydrogen + + + align:start position:0% +detectable you can have the hydrogen +atom and if you want to study the + + align:start position:0% +atom and if you want to study the + + + align:start position:0% +atom and if you want to study the +hydrogen atom how does an + + align:start position:0% +hydrogen atom how does an + + + align:start position:0% +hydrogen atom how does an +experimentalist look at the hydrogen + + align:start position:0% +experimentalist look at the hydrogen + + + align:start position:0% +experimentalist look at the hydrogen +atom puts a hydrogen atom and inserts a + + align:start position:0% +atom puts a hydrogen atom and inserts a + + + align:start position:0% +atom puts a hydrogen atom and inserts a +magnetic field and sees what happens to + + align:start position:0% +magnetic field and sees what happens to + + + align:start position:0% +magnetic field and sees what happens to +the energy + + align:start position:0% +the energy + + + align:start position:0% +the energy +levels and then inserts an electric + + align:start position:0% +levels and then inserts an electric + + + align:start position:0% +levels and then inserts an electric +field this is what happens to the energy + + align:start position:0% +field this is what happens to the energy + + + align:start position:0% +field this is what happens to the energy +levels and those can be thought as + + align:start position:0% +levels and those can be thought as + + + align:start position:0% +levels and those can be thought as +slight variations of the original + + align:start position:0% +slight variations of the original + + + align:start position:0% +slight variations of the original +hamiltonian Vander Val's forces are you + + align:start position:0% +hamiltonian Vander Val's forces are you + + + align:start position:0% +hamiltonian Vander Val's forces are you +have two neutral atoms and they induce + + align:start position:0% +have two neutral atoms and they induce + + + align:start position:0% +have two neutral atoms and they induce +on each other diple moments and generate + + align:start position:0% +on each other diple moments and generate + + + align:start position:0% +on each other diple moments and generate +a force a very tiny effect on + + align:start position:0% +a force a very tiny effect on + + + align:start position:0% +a force a very tiny effect on +otherwise simple hydrogen atoms + + align:start position:0% +otherwise simple hydrogen atoms + + + align:start position:0% +otherwise simple hydrogen atoms +structure but a very important Force the + + align:start position:0% +structure but a very important Force the + + + align:start position:0% +structure but a very important Force the +vand deral force so what we're going to + + align:start position:0% +vand deral force so what we're going to + + + align:start position:0% +vand deral force so what we're going to +be doing is trying to understand these + + align:start position:0% +be doing is trying to understand these + + + align:start position:0% +be doing is trying to understand these +situations in which we + + align:start position:0% +situations in which we + + + align:start position:0% +situations in which we +have a + + align:start position:0% + + + + align:start position:0% + +hamiltonian that is + + align:start position:0% +hamiltonian that is + + + align:start position:0% +hamiltonian that is +equal to a wellknown hamiltonian this + + align:start position:0% +equal to a wellknown hamiltonian this + + + align:start position:0% +equal to a wellknown hamiltonian this +h0 zero meaning no perturbation no + + align:start position:0% +h0 zero meaning no perturbation no + + + align:start position:0% +h0 zero meaning no perturbation no +variation this is our wellknown + + align:start position:0% + + + + align:start position:0% + +known + + align:start position:0% + + + + align:start position:0% + +system but then there's going to + + align:start position:0% +system but then there's going to + + + align:start position:0% +system but then there's going to +be an extra piece to that hamiltonian + + align:start position:0% +be an extra piece to that hamiltonian + + + align:start position:0% +be an extra piece to that hamiltonian +and we're going to call it Delta H Delta + + align:start position:0% +and we're going to call it Delta H Delta + + + align:start position:0% +and we're going to call it Delta H Delta +H is yet another + + align:start position:0% +H is yet another + + + align:start position:0% +H is yet another +hamiltonian it may be complicated may be + + align:start position:0% +hamiltonian it may be complicated may be + + + align:start position:0% +hamiltonian it may be complicated may be +simple uh + + align:start position:0% +simple uh + + + align:start position:0% +simple uh +but it's different from + + align:start position:0% +but it's different from + + + align:start position:0% +but it's different from +h0 now this will be the hamiltonian of + + align:start position:0% +h0 now this will be the hamiltonian of + + + align:start position:0% +h0 now this will be the hamiltonian of +the system that you're really trying to + + align:start position:0% +the system that you're really trying to + + + align:start position:0% +the system that you're really trying to +describe and therefore U you should + + align:start position:0% +describe and therefore U you should + + + align:start position:0% +describe and therefore U you should +demand of course that h0 Delta H and H + + align:start position:0% +demand of course that h0 Delta H and H + + + align:start position:0% +demand of course that h0 Delta H and H +are all her + + align:start position:0% +are all her + + + align:start position:0% +are all her +Mission all hamiltonians are supposed to + + align:start position:0% +Mission all hamiltonians are supposed to + + + align:start position:0% +Mission all hamiltonians are supposed to +be her + + align:start position:0% +be her + + + align:start position:0% +be her +Mission and this is uh the situation + + align:start position:0% +Mission and this is uh the situation + + + align:start position:0% +Mission and this is uh the situation +with want to understand in general this + + align:start position:0% +with want to understand in general this + + + align:start position:0% +with want to understand in general this +is + + align:start position:0% +is + + + align:start position:0% +is +the + + align:start position:0% +the + + + align:start position:0% +the +concrete mathematical description of the + + align:start position:0% +concrete mathematical description of the + + + align:start position:0% +concrete mathematical description of the +problem but we do a little more here we + + align:start position:0% +problem but we do a little more here we + + + align:start position:0% +problem but we do a little more here we +need a tool to help us deal with this + + align:start position:0% +need a tool to help us deal with this + + + align:start position:0% +need a tool to help us deal with this +and there's a wonderful nice tool + + align:start position:0% +and there's a wonderful nice tool + + + align:start position:0% +and there's a wonderful nice tool +provided by a parameter a parameter here + + align:start position:0% +provided by a parameter a parameter here + + + align:start position:0% +provided by a parameter a parameter here +makes all the + + align:start position:0% +makes all the + + + align:start position:0% +makes all the +difference what is this parameter it's a + + align:start position:0% +difference what is this parameter it's a + + + align:start position:0% +difference what is this parameter it's a +parameter we like to put here and we'll + + align:start position:0% +parameter we like to put here and we'll + + + align:start position:0% +parameter we like to put here and we'll +call it line + + align:start position:0% +call it line + + + align:start position:0% +call it line +Lambda you might have said no I don't + + align:start position:0% +Lambda you might have said no I don't + + + align:start position:0% +Lambda you might have said no I don't +have such thing U this is what I want to + + align:start position:0% +have such thing U this is what I want to + + + align:start position:0% +have such thing U this is what I want to +do but still it's better to put a Lambda + + align:start position:0% +do but still it's better to put a Lambda + + + align:start position:0% +do but still it's better to put a Lambda +there where Lambda is + + align:start position:0% +there where Lambda is + + + align:start position:0% +there where Lambda is +unitree no units and belongs to the + + align:start position:0% +unitree no units and belongs to the + + + align:start position:0% +unitree no units and belongs to the +interval 0 to + + align:start position:0% + + + + align:start position:0% + +one in that way you will have defined a + + align:start position:0% +one in that way you will have defined a + + + align:start position:0% +one in that way you will have defined a +family of hamiltonians that depend on + + align:start position:0% +family of hamiltonians that depend on + + + align:start position:0% +family of hamiltonians that depend on +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +and Lambda is this quantity that you can + + align:start position:0% +and Lambda is this quantity that you can + + + align:start position:0% +and Lambda is this quantity that you can +vary from zero to one so you decide + + align:start position:0% +vary from zero to one so you decide + + + align:start position:0% +vary from zero to one so you decide +you're going to solve a more General + + align:start position:0% +you're going to solve a more General + + + align:start position:0% +you're going to solve a more General +problem perhaps you knew what is the + + align:start position:0% +problem perhaps you knew what is the + + + align:start position:0% +problem perhaps you knew what is the +extra term in the hamiltonian and you + + align:start position:0% +extra term in the hamiltonian and you + + + align:start position:0% +extra term in the hamiltonian and you +say why do I bother with Lambda the + + align:start position:0% +say why do I bother with Lambda the + + + align:start position:0% +say why do I bother with Lambda the +reason you bother with Lambda is that + + align:start position:0% +reason you bother with Lambda is that + + + align:start position:0% +reason you bother with Lambda is that +it's going to help us solve the + + align:start position:0% +it's going to help us solve the + + + align:start position:0% +it's going to help us solve the +equations clearly and second physically + + align:start position:0% +equations clearly and second physically + + + align:start position:0% +equations clearly and second physically +it's kind of interesting because you + + align:start position:0% +it's kind of interesting because you + + + align:start position:0% +it's kind of interesting because you +could think of Lambda as a extra + + align:start position:0% +could think of Lambda as a extra + + + align:start position:0% +could think of Lambda as a extra +parameter of the physics in which you + + align:start position:0% +parameter of the physics in which you + + + align:start position:0% +parameter of the physics in which you +maybe set it equal to zero and you + + align:start position:0% +maybe set it equal to zero and you + + + align:start position:0% +maybe set it equal to zero and you +recover the original + + align:start position:0% +recover the original + + + align:start position:0% +recover the original +hamiltonian or you vary it + + align:start position:0% +hamiltonian or you vary it + + + align:start position:0% +hamiltonian or you vary it +and when it reaches one it is the + + align:start position:0% +and when it reaches one it is the + + + align:start position:0% +and when it reaches one it is the +Hamilton and you're trying to + + align:start position:0% + + + + align:start position:0% + +solve on the other hand this parameter + + align:start position:0% +solve on the other hand this parameter + + + align:start position:0% +solve on the other hand this parameter +allows you to do something very nice too + + align:start position:0% +allows you to do something very nice too + + + align:start position:0% +allows you to do something very nice too +one of the things we're going to try to + + align:start position:0% +one of the things we're going to try to + + + align:start position:0% +one of the things we're going to try to +clarify by the end of this lecture is + + align:start position:0% +clarify by the end of this lecture is + + + align:start position:0% +clarify by the end of this lecture is +shouldn't this thing be rather small + + align:start position:0% +shouldn't this thing be rather small + + + align:start position:0% +shouldn't this thing be rather small +compared to this one if we want to say + + align:start position:0% +compared to this one if we want to say + + + align:start position:0% +compared to this one if we want to say +it with deform the system slightly we + + align:start position:0% +it with deform the system slightly we + + + align:start position:0% +it with deform the system slightly we +want the correction to be small compared + + align:start position:0% +want the correction to be small compared + + + align:start position:0% +want the correction to be small compared +to the original + + align:start position:0% +to the original + + + align:start position:0% +to the original +hamiltonian so what does it mean for a + + align:start position:0% +hamiltonian so what does it mean for a + + + align:start position:0% +hamiltonian so what does it mean for a +hamiltonian to be small compared to + + align:start position:0% +hamiltonian to be small compared to + + + align:start position:0% +hamiltonian to be small compared to +another hamiltonian these are operator + + align:start position:0% +another hamiltonian these are operator + + + align:start position:0% +another hamiltonian these are operator +so what does it mean + + align:start position:0% +so what does it mean + + + align:start position:0% +so what does it mean +small you could say well + + align:start position:0% +small you could say well + + + align:start position:0% +small you could say well +I don't know precisely what it means + + align:start position:0% +I don't know precisely what it means + + + align:start position:0% +I don't know precisely what it means +small maybe it means that the Matrix + + align:start position:0% +small maybe it means that the Matrix + + + align:start position:0% +small maybe it means that the Matrix +elements of this Delta + + align:start position:0% +elements of this Delta + + + align:start position:0% +elements of this Delta +H are small compared to the Matrix + + align:start position:0% +H are small compared to the Matrix + + + align:start position:0% +H are small compared to the Matrix +elements of that and that is true + + align:start position:0% +elements of that and that is true + + + align:start position:0% +elements of that and that is true +surprisingly will not be + + align:start position:0% +surprisingly will not be + + + align:start position:0% +surprisingly will not be +enough on the other + + align:start position:0% +enough on the other + + + align:start position:0% +enough on the other +hand whatever is small we could all + + align:start position:0% +hand whatever is small we could all + + + align:start position:0% +hand whatever is small we could all +agree that if th if this is not small we + + align:start position:0% +agree that if th if this is not small we + + + align:start position:0% +agree that if th if this is not small we +could put Lambda equal + + align:start position:0% +could put Lambda equal + + + align:start position:0% +could put Lambda equal +0.01 maybe that's small but if that's + + align:start position:0% +0.01 maybe that's small but if that's + + + align:start position:0% +0.01 maybe that's small but if that's +not + + align:start position:0% +not + + + align:start position:0% +not +small Lambda equal 10 the- 9 if that's + + align:start position:0% +small Lambda equal 10 the- 9 if that's + + + align:start position:0% +small Lambda equal 10 the- 9 if that's +not small 10 Theus 30 at some point this + + align:start position:0% +not small 10 Theus 30 at some point this + + + align:start position:0% +not small 10 Theus 30 at some point this +will be small enough and uh therefore we + + align:start position:0% +will be small enough and uh therefore we + + + align:start position:0% +will be small enough and uh therefore we +could try to make sense this allows you + + align:start position:0% +could try to make sense this allows you + + + align:start position:0% +could try to make sense this allows you +to really think of this as a + + align:start position:0% +to really think of this as a + + + align:start position:0% +to really think of this as a +perturbation for whatever Delta H is for + + align:start position:0% +perturbation for whatever Delta H is for + + + align:start position:0% +perturbation for whatever Delta H is for +sufficiently small Lambda this is + + align:start position:0% + + + + align:start position:0% + +small so uh this is what we're going to + + align:start position:0% +small so uh this is what we're going to + + + align:start position:0% +small so uh this is what we're going to +try to solve and let's try to imagine + + align:start position:0% +try to solve and let's try to imagine + + + align:start position:0% +try to solve and let's try to imagine +first um what can + + align:start position:0% + + + + align:start position:0% + +happen so I'm going to try to + + align:start position:0% +happen so I'm going to try to + + + align:start position:0% +happen so I'm going to try to +imagine what's going + + align:start position:0% +imagine what's going + + + align:start position:0% +imagine what's going +on a plot that's the best way to imagine + + align:start position:0% +on a plot that's the best way to imagine + + + align:start position:0% +on a plot that's the best way to imagine +thing so I'll do a + + align:start position:0% +thing so I'll do a + + + align:start position:0% +thing so I'll do a +plot here I put Lambda + + align:start position:0% +plot here I put Lambda + + + align:start position:0% +plot here I put Lambda +and here in the vertical axis I will + + align:start position:0% +and here in the vertical axis I will + + + align:start position:0% +and here in the vertical axis I will +indicate the spectrum of + + align:start position:0% +indicate the spectrum of + + + align:start position:0% +indicate the spectrum of +h0 the spectrum + + align:start position:0% + + + + align:start position:0% + +of of h0 so this is going to be an + + align:start position:0% + + + + align:start position:0% + +energy so it may happen that the in our + + align:start position:0% +energy so it may happen that the in our + + + align:start position:0% +energy so it may happen that the in our +systems there's a ground state + + align:start position:0% + + + + align:start position:0% + +and this ground state is going to be a + + align:start position:0% +and this ground state is going to be a + + + align:start position:0% +and this ground state is going to be a +single state I will not put a name into + + align:start position:0% +single state I will not put a name into + + + align:start position:0% +single state I will not put a name into +it I will just say there is one state + + align:start position:0% + + + + align:start position:0% + +here that means the ground state is non + + align:start position:0% +here that means the ground state is non + + + align:start position:0% +here that means the ground state is non +degenerate the generate states are + + align:start position:0% +degenerate the generate states are + + + align:start position:0% +degenerate the generate states are +states of the same energy and I say + + align:start position:0% +states of the same energy and I say + + + align:start position:0% +states of the same energy and I say +there's just one state so not + + align:start position:0% +there's just one state so not + + + align:start position:0% +there's just one state so not +degeneracy suppose you go here + + align:start position:0% +degeneracy suppose you go here + + + align:start position:0% +degeneracy suppose you go here +and now you find two states so I put two + + align:start position:0% +and now you find two states so I put two + + + align:start position:0% +and now you find two states so I put two +dots here to indicate that there are two + + align:start position:0% +dots here to indicate that there are two + + + align:start position:0% +dots here to indicate that there are two +states + + align:start position:0% +states + + + align:start position:0% +states +there finally let's go higher up and + + align:start position:0% +there finally let's go higher up and + + + align:start position:0% +there finally let's go higher up and +assume that this hamiltonian maybe has + + align:start position:0% +assume that this hamiltonian maybe has + + + align:start position:0% +assume that this hamiltonian maybe has +one state + + align:start position:0% +one state + + + align:start position:0% +one state +here but here it has four + + align:start position:0% + + + + align:start position:0% + +states and these are the energies those + + align:start position:0% +states and these are the energies those + + + align:start position:0% +states and these are the energies those +are some numbers and this Spectrum must + + align:start position:0% +are some numbers and this Spectrum must + + + align:start position:0% +are some numbers and this Spectrum must +continue to exist so this is the + + align:start position:0% +continue to exist so this is the + + + align:start position:0% +continue to exist so this is the +spectrum of your + + align:start position:0% +spectrum of your + + + align:start position:0% +spectrum of your +h0 the hamiltonian you + + align:start position:0% +h0 the hamiltonian you + + + align:start position:0% +h0 the hamiltonian you +know certainly uh the hydrogen atom + + align:start position:0% +know certainly uh the hydrogen atom + + + align:start position:0% +know certainly uh the hydrogen atom +hamiltonian has the generate state so + + align:start position:0% +hamiltonian has the generate state so + + + align:start position:0% +hamiltonian has the generate state so +that's roughly what's happening + + align:start position:0% +that's roughly what's happening + + + align:start position:0% +that's roughly what's happening +there um the simple harmonic oscillator + + align:start position:0% +there um the simple harmonic oscillator + + + align:start position:0% +there um the simple harmonic oscillator +in one dimension doesn't have the + + align:start position:0% +in one dimension doesn't have the + + + align:start position:0% +in one dimension doesn't have the +generate States but the + + align:start position:0% +generate States but the + + + align:start position:0% +generate States but the +isotropic harmonic oscillator in two or + + align:start position:0% +isotropic harmonic oscillator in two or + + + align:start position:0% +isotropic harmonic oscillator in two or +three three dimensions does have lots of + + align:start position:0% +three three dimensions does have lots of + + + align:start position:0% +three three dimensions does have lots of +degeneracies you've seen those + + align:start position:0% +degeneracies you've seen those + + + align:start position:0% +degeneracies you've seen those +probably so that's typical so what are + + align:start position:0% +probably so that's typical so what are + + + align:start position:0% +probably so that's typical so what are +we aiming to understand we're aiming to + + align:start position:0% +we aiming to understand we're aiming to + + + align:start position:0% +we aiming to understand we're aiming to +understand what happens to the energy of + + align:start position:0% +understand what happens to the energy of + + + align:start position:0% +understand what happens to the energy of +those + + align:start position:0% +those + + + align:start position:0% +those +States or what happens to the energy ion + + align:start position:0% +States or what happens to the energy ion + + + align:start position:0% +States or what happens to the energy ion +States as the perturbation is turned on + + align:start position:0% +States as the perturbation is turned on + + + align:start position:0% +States as the perturbation is turned on +so imagining Lambda going from 0er to + + align:start position:0% +so imagining Lambda going from 0er to + + + align:start position:0% +so imagining Lambda going from 0er to +one the process of turning on the + + align:start position:0% +one the process of turning on the + + + align:start position:0% +one the process of turning on the +perturbation + + align:start position:0% +perturbation + + + align:start position:0% +perturbation +and the igen states are going to change + + align:start position:0% +and the igen states are going to change + + + align:start position:0% +and the igen states are going to change +because whatever was an igen state of H + + align:start position:0% +because whatever was an igen state of H + + + align:start position:0% +because whatever was an igen state of H +zero is not going to be an Nan state of + + align:start position:0% +zero is not going to be an Nan state of + + + align:start position:0% +zero is not going to be an Nan state of +the new hamiltonian and the energies are + + align:start position:0% +the new hamiltonian and the energies are + + + align:start position:0% +the new hamiltonian and the energies are +going to change so everything is going + + align:start position:0% +going to change so everything is going + + + align:start position:0% +going to change so everything is going +to change but presumably it will happen + + align:start position:0% +to change but presumably it will happen + + + align:start position:0% +to change but presumably it will happen +continuously as you change Lambda + + align:start position:0% +continuously as you change Lambda + + + align:start position:0% +continuously as you change Lambda +continuously from zero to + + align:start position:0% +continuously from zero to + + + align:start position:0% +continuously from zero to +one so this first state for example exle + + align:start position:0% +one so this first state for example exle + + + align:start position:0% +one so this first state for example exle +may do + + align:start position:0% +may do + + + align:start position:0% +may do +this I don't know what it will do but it + + align:start position:0% +this I don't know what it will do but it + + + align:start position:0% +this I don't know what it will do but it +will vary as a function of Lambda the + + align:start position:0% +will vary as a function of Lambda the + + + align:start position:0% +will vary as a function of Lambda the +energy we'll do something maybe we can + + align:start position:0% +energy we'll do something maybe we can + + + align:start position:0% +energy we'll do something maybe we can +cut it here and say that Lambda is equal + + align:start position:0% +cut it here and say that Lambda is equal + + + align:start position:0% +cut it here and say that Lambda is equal +to one + + align:start position:0% + + + + align:start position:0% + +here now we have two + + align:start position:0% + + + + align:start position:0% + +states so I can analyze this state with + + align:start position:0% +states so I can analyze this state with + + + align:start position:0% +states so I can analyze this state with +what's called n degenerate perturbation + + align:start position:0% +what's called n degenerate perturbation + + + align:start position:0% +what's called n degenerate perturbation +in theory which means you have a non + + align:start position:0% +in theory which means you have a non + + + align:start position:0% +in theory which means you have a non +degenerate State and there are + + align:start position:0% +degenerate State and there are + + + align:start position:0% +degenerate State and there are +techniques that we're going to do today + + align:start position:0% +techniques that we're going to do today + + + align:start position:0% +techniques that we're going to do today +to understand how this state varies but + + align:start position:0% +to understand how this state varies but + + + align:start position:0% +to understand how this state varies but +how about this one here you have two + + align:start position:0% +how about this one here you have two + + + align:start position:0% +how about this one here you have two +states what happens to them well two + + align:start position:0% +states what happens to them well two + + + align:start position:0% +states what happens to them well two +states should remain two states and + + align:start position:0% +states should remain two states and + + + align:start position:0% +states should remain two states and +their energies what will they do maybe + + align:start position:0% +their energies what will they do maybe + + + align:start position:0% +their energies what will they do maybe +they'll track each other but maybe the + + align:start position:0% +they'll track each other but maybe the + + + align:start position:0% +they'll track each other but maybe the +perturbation splits the degeneracy + + align:start position:0% +perturbation splits the degeneracy + + + align:start position:0% +perturbation splits the degeneracy +that's a very important phenomenon let's + + align:start position:0% +that's a very important phenomenon let's + + + align:start position:0% +that's a very important phenomenon let's +assume it does that so it may look like + + align:start position:0% + + + + align:start position:0% + +this like that for example the + + align:start position:0% +this like that for example the + + + align:start position:0% +this like that for example the +perturbation makes one state have more + + align:start position:0% +perturbation makes one state have more + + + align:start position:0% +perturbation makes one state have more +energy than the + + align:start position:0% + + + + align:start position:0% + +other here is another + + align:start position:0% + + + + align:start position:0% + +state now a phenomenon that might + + align:start position:0% +state now a phenomenon that might + + + align:start position:0% +state now a phenomenon that might +happen many things can happen this is a + + align:start position:0% +happen many things can happen this is a + + + align:start position:0% +happen many things can happen this is a +very rich subject because of all the + + align:start position:0% +very rich subject because of all the + + + align:start position:0% +very rich subject because of all the +things that can happen it may happen + + align:start position:0% +things that can happen it may happen + + + align:start position:0% +things that can happen it may happen +that this thing for + + align:start position:0% +that this thing for + + + align:start position:0% +that this thing for +example goes like + + align:start position:0% + + + + align:start position:0% + +this and like that but there are four + + align:start position:0% +this and like that but there are four + + + align:start position:0% +this and like that but there are four +states it may be that one state goes + + align:start position:0% +states it may be that one state goes + + + align:start position:0% +states it may be that one state goes +here and three states go here but then + + align:start position:0% +here and three states go here but then + + + align:start position:0% +here and three states go here but then +after a little while they'll + + align:start position:0% + + + + align:start position:0% + +depart how many did I want no I got too + + align:start position:0% +depart how many did I want no I got too + + + align:start position:0% +depart how many did I want no I got too +many well five + + align:start position:0% + + + + align:start position:0% + +all right so it may happen something + + align:start position:0% +all right so it may happen something + + + align:start position:0% +all right so it may happen something +like that that they split and then to + + align:start position:0% +like that that they split and then to + + + align:start position:0% +like that that they split and then to +higher order they keep splitting + + align:start position:0% +higher order they keep splitting + + + align:start position:0% +higher order they keep splitting +um in fact they're splitting here + + align:start position:0% +um in fact they're splitting here + + + align:start position:0% +um in fact they're splitting here +already but you don't see it it's just + + align:start position:0% +already but you don't see it it's just + + + align:start position:0% +already but you don't see it it's just +coming is too close just the same way as + + align:start position:0% +coming is too close just the same way as + + + align:start position:0% +coming is too close just the same way as +X SAR and x to the 4th and x to the 8 + + align:start position:0% +X SAR and x to the 4th and x to the 8 + + + align:start position:0% +X SAR and x to the 4th and x to the 8 +sort of at the origin they all look the + + align:start position:0% +sort of at the origin they all look the + + + align:start position:0% +sort of at the origin they all look the +same and then they eventually + + align:start position:0% +same and then they eventually + + + align:start position:0% +same and then they eventually +split so this is what we're going to to + + align:start position:0% +split so this is what we're going to to + + + align:start position:0% +split so this is what we're going to to +try to understand for + + align:start position:0% +try to understand for + + + align:start position:0% +try to understand for +this we need non degenerate perturbation + + align:start position:0% +this we need non degenerate perturbation + + + align:start position:0% +this we need non degenerate perturbation +theory for this degenerate perturbation + + align:start position:0% +theory for this degenerate perturbation + + + align:start position:0% +theory for this degenerate perturbation +theory for this we need sophisticated + + align:start position:0% +theory for this we need sophisticated + + + align:start position:0% +theory for this we need sophisticated +degenerate perturbation Theory very + + align:start position:0% +degenerate perturbation Theory very + + + align:start position:0% +degenerate perturbation Theory very +intricate phenomenon but still it + + align:start position:0% +intricate phenomenon but still it + + + align:start position:0% +intricate phenomenon but still it +happens and happens in many + + align:start position:0% +happens and happens in many + + + align:start position:0% +happens and happens in many +applications so we're going to start + + align:start position:0% +applications so we're going to start + + + align:start position:0% +applications so we're going to start +with a simpler one which is non + + align:start position:0% +with a simpler one which is non + + + align:start position:0% +with a simpler one which is non +degenerate perturbation Theory non + + align:start position:0% +degenerate perturbation Theory non + + + align:start position:0% +degenerate perturbation Theory non +degenerate perturbation Theory + + align:start position:0% +degenerate perturbation Theory + + + align:start position:0% +degenerate perturbation Theory +non the generate perturbation Theory and + + align:start position:0% +non the generate perturbation Theory and + + + align:start position:0% +non the generate perturbation Theory and +then we say well what does it mean that + + align:start position:0% +then we say well what does it mean that + + + align:start position:0% +then we say well what does it mean that +we understand + + align:start position:0% +we understand + + + align:start position:0% +we understand +h0 it means that we have + + align:start position:0% +h0 it means that we have + + + align:start position:0% +h0 it means that we have +found all the igen states with K one + + align:start position:0% +found all the igen states with K one + + + align:start position:0% +found all the igen states with K one +maybe up to Infinity I don't know K is + + align:start position:0% +maybe up to Infinity I don't know K is + + + align:start position:0% +maybe up to Infinity I don't know K is +not momentum these are the energy I + + align:start position:0% +not momentum these are the energy I + + + align:start position:0% +not momentum these are the energy I +states of h0 that we're supposed to know + + align:start position:0% +states of h0 that we're supposed to know + + + align:start position:0% +states of h0 that we're supposed to know +and there all + + align:start position:0% +and there all + + + align:start position:0% +and there all +orthonormal that can always be done when + + align:start position:0% +orthonormal that can always be done when + + + align:start position:0% +orthonormal that can always be done when +you have a Herm Mission hamiltonian you + + align:start position:0% +you have a Herm Mission hamiltonian you + + + align:start position:0% +you have a Herm Mission hamiltonian you +can find an orthonormal basis of states + + align:start position:0% +can find an orthonormal basis of states + + + align:start position:0% +can find an orthonormal basis of states +and being + + align:start position:0% + + + + align:start position:0% + +orthonormal + + align:start position:0% +orthonormal + + + align:start position:0% +orthonormal +this orthogonality holds the states are + + align:start position:0% +this orthogonality holds the states are + + + align:start position:0% +this orthogonality holds the states are +igen states of + + align:start position:0% +igen states of + + + align:start position:0% +igen states of +the h0 so for + + align:start position:0% +the h0 so for + + + align:start position:0% +the h0 so for +this will will call this e + + align:start position:0% + + + + align:start position:0% + +k0 the energy of this state k for the + + align:start position:0% +k0 the energy of this state k for the + + + align:start position:0% +k0 the energy of this state k for the +label of the state zero because we're + + align:start position:0% +label of the state zero because we're + + + align:start position:0% +label of the state zero because we're +not doing anything in perturbation yet + + align:start position:0% +not doing anything in perturbation yet + + + align:start position:0% +not doing anything in perturbation yet +we're dealing with the + + align:start position:0% +we're dealing with the + + + align:start position:0% +we're dealing with the +unperturbed zero or + + align:start position:0% + + + + align:start position:0% + +system that defines the energies and + + align:start position:0% +system that defines the energies and + + + align:start position:0% +system that defines the energies and +this uh energies satisfy I say e 0 0 is + + align:start position:0% +this uh energies satisfy I say e 0 0 is + + + align:start position:0% +this uh energies satisfy I say e 0 0 is +less than or equal than E1 + + align:start position:0% +less than or equal than E1 + + + align:start position:0% +less than or equal than E1 +0 less than or equal to + + align:start position:0% +0 less than or equal to + + + align:start position:0% +0 less than or equal to +E20 so all the energies are + + align:start position:0% +E20 so all the energies are + + + align:start position:0% +E20 so all the energies are +ordered um I need the equals because of + + align:start position:0% +ordered um I need the equals because of + + + align:start position:0% +ordered um I need the equals because of +the + + align:start position:0% +the + + + align:start position:0% +the +degeneracy might be degenerate so you + + align:start position:0% +degeneracy might be degenerate so you + + + align:start position:0% +degeneracy might be degenerate so you +have this uh + + align:start position:0% +have this uh + + + align:start position:0% +have this uh +situation so + + align:start position:0% + + + + align:start position:0% + +um let's + + align:start position:0% +um let's + + + align:start position:0% +um let's +consider this + + align:start position:0% + + + + align:start position:0% + +state that is non degenerate and let's + + align:start position:0% +state that is non degenerate and let's + + + align:start position:0% +state that is non degenerate and let's +assume this is the state + + align:start position:0% + + + + align:start position:0% + +n0 is the nth + + align:start position:0% +n0 is the nth + + + align:start position:0% +n0 is the nth +state if + + align:start position:0% + + + + align:start position:0% + +n0 is non + + align:start position:0% +n0 is non + + + align:start position:0% +n0 is non +degenerate it means that e + + align:start position:0% + + + + align:start position:0% + +n0 is really smaller than the next + + align:start position:0% + + + + align:start position:0% + +one and it's really bigger the energy + + align:start position:0% +one and it's really bigger the energy + + + align:start position:0% +one and it's really bigger the energy +than the previous + + align:start position:0% + + + + align:start position:0% + +one no equal signs there it really means + + align:start position:0% +one no equal signs there it really means + + + align:start position:0% +one no equal signs there it really means +those things are + + align:start position:0% +those things are + + + align:start position:0% +those things are +separate and that's the meaning of + + align:start position:0% +separate and that's the meaning of + + + align:start position:0% +separate and that's the meaning of +non + + align:start position:0% + + + + align:start position:0% + +degeneracy and now what are we trying to + + align:start position:0% + + + + align:start position:0% + +solve starting from this + + align:start position:0% +solve starting from this + + + align:start position:0% +solve starting from this +n0o we're trying to find how the energy + + align:start position:0% +n0o we're trying to find how the energy + + + align:start position:0% +n0o we're trying to find how the energy +changes and how the state changes both + + align:start position:0% +changes and how the state changes both + + + align:start position:0% +changes and how the state changes both +things are important so + + align:start position:0% +things are important so + + + align:start position:0% +things are important so +um we're going to try to solve therefore + + align:start position:0% +um we're going to try to solve therefore + + + align:start position:0% +um we're going to try to solve therefore +for for H of + + align:start position:0% +for for H of + + + align:start position:0% +for for H of +Lambda n Lambda the state n0 is going to + + align:start position:0% +Lambda n Lambda the state n0 is going to + + + align:start position:0% +Lambda n Lambda the state n0 is going to +change when Lambda turns on and it's + + align:start position:0% +change when Lambda turns on and it's + + + align:start position:0% +change when Lambda turns on and it's +going to become n of Lambda and this is + + align:start position:0% +going to become n of Lambda and this is + + + align:start position:0% +going to become n of Lambda and this is +going to have an energy e n + + align:start position:0% + + + + align:start position:0% + +Lambda instead of e + + align:start position:0% +Lambda instead of e + + + align:start position:0% +Lambda instead of e +n0 this has an energy e + + align:start position:0% +n0 this has an energy e + + + align:start position:0% +n0 this has an energy e +n zero with respect to the original + + align:start position:0% +n zero with respect to the original + + + align:start position:0% +n zero with respect to the original +hamiltonian now it's going to have an + + align:start position:0% +hamiltonian now it's going to have an + + + align:start position:0% +hamiltonian now it's going to have an +energy e n of + + align:start position:0% +energy e n of + + + align:start position:0% +energy e n of +Lambda n of Lambda so that's the + + align:start position:0% +Lambda n of Lambda so that's the + + + align:start position:0% +Lambda n of Lambda so that's the +equation we want to + + align:start position:0% +equation we want to + + + align:start position:0% +equation we want to +solve this + + align:start position:0% +solve this + + + align:start position:0% +solve this +is what the state n z becomes as you + + align:start position:0% +is what the state n z becomes as you + + + align:start position:0% +is what the state n z becomes as you +turn on Lambda and this is what the + + align:start position:0% +turn on Lambda and this is what the + + + align:start position:0% +turn on Lambda and this is what the +energy n0 becomes as you turn on Lambda + + align:start position:0% +energy n0 becomes as you turn on Lambda + + + align:start position:0% +energy n0 becomes as you turn on Lambda +so we note that n when Lambda equal to + + align:start position:0% +so we note that n when Lambda equal to + + + align:start position:0% +so we note that n when Lambda equal to +Z is what we call the state + + align:start position:0% +Z is what we call the state + + + align:start position:0% +Z is what we call the state +n0 and the energy e n at Lambda equal 0 + + align:start position:0% +n0 and the energy e n at Lambda equal 0 + + + align:start position:0% +n0 and the energy e n at Lambda equal 0 +is what we called e + + align:start position:0% + + + + align:start position:0% + +n0 so with this initial conditions at + + align:start position:0% +n0 so with this initial conditions at + + + align:start position:0% +n0 so with this initial conditions at +Lambda equals z we're trying to solve + + align:start position:0% +Lambda equals z we're trying to solve + + + align:start position:0% +Lambda equals z we're trying to solve +this system to see what the state + + align:start position:0% +this system to see what the state + + + align:start position:0% +this system to see what the state +becomes and now here comes a a key + + align:start position:0% +becomes and now here comes a a key + + + align:start position:0% +becomes and now here comes a a key +assumption that the way we're going to + + align:start position:0% +assumption that the way we're going to + + + align:start position:0% +assumption that the way we're going to +solve this allows us to write a + + align:start position:0% +solve this allows us to write a + + + align:start position:0% +solve this allows us to write a +perturbative serious expansion for this + + align:start position:0% +perturbative serious expansion for this + + + align:start position:0% +perturbative serious expansion for this +objects so in particular we'll write n + + align:start position:0% +objects so in particular we'll write n + + + align:start position:0% +objects so in particular we'll write n +of + + align:start position:0% +of + + + align:start position:0% +of +Lambda is equal to + + align:start position:0% +Lambda is equal to + + + align:start position:0% +Lambda is equal to +n0 that's what n of Lambda should be + + align:start position:0% +n0 that's what n of Lambda should be + + + align:start position:0% +n0 that's what n of Lambda should be +when Lambda is equal to zero so then + + align:start position:0% +when Lambda is equal to zero so then + + + align:start position:0% +when Lambda is equal to zero so then +there will be a first order correction + + align:start position:0% +there will be a first order correction + + + align:start position:0% +there will be a first order correction +Lambda time the state + + align:start position:0% +Lambda time the state + + + align:start position:0% +Lambda time the state +N1 plus Lambda squar * the state + + align:start position:0% +N1 plus Lambda squar * the state + + + align:start position:0% +N1 plus Lambda squar * the state +N2 and it will go on and + + align:start position:0% +N2 and it will go on and + + + align:start position:0% +N2 and it will go on and +on moreover e n + + align:start position:0% +on moreover e n + + + align:start position:0% +on moreover e n +Lambda when Lambda is equal to zero + + align:start position:0% +Lambda when Lambda is equal to zero + + + align:start position:0% +Lambda when Lambda is equal to zero +you're back to the energy e + + align:start position:0% + + + + align:start position:0% + +n0 but then there will be a Lambda corre + + align:start position:0% +n0 but then there will be a Lambda corre + + + align:start position:0% +n0 but then there will be a Lambda corre +ction time e + + align:start position:0% + + + + align:start position:0% + +N1 that's a name for the first order + + align:start position:0% +N1 that's a name for the first order + + + align:start position:0% +N1 that's a name for the first order +correction plus a Lambda squared + + align:start position:0% +correction plus a Lambda squared + + + align:start position:0% +correction plus a Lambda squared +correction e n + + align:start position:0% + + + + align:start position:0% + +2 so this is our + + align:start position:0% +2 so this is our + + + align:start position:0% +2 so this is our +hypothesis that there is a solution in a + + align:start position:0% +hypothesis that there is a solution in a + + + align:start position:0% +hypothesis that there is a solution in a +perative series expansion + + align:start position:0% +perative series expansion + + + align:start position:0% +perative series expansion +of this kind and what are our unknowns + + align:start position:0% +of this kind and what are our unknowns + + + align:start position:0% +of this kind and what are our unknowns +our unknowns are this object this one we + + align:start position:0% +our unknowns are this object this one we + + + align:start position:0% +our unknowns are this object this one we +know is the original state this object + + align:start position:0% +know is the original state this object + + + align:start position:0% +know is the original state this object +is unknown this is + + align:start position:0% +is unknown this is + + + align:start position:0% +is unknown this is +unknown this is + + align:start position:0% +unknown this is + + + align:start position:0% +unknown this is +unknown all these things are unknown and + + align:start position:0% +unknown all these things are unknown and + + + align:start position:0% +unknown all these things are unknown and +they go on like that most important all + + align:start position:0% +they go on like that most important all + + + align:start position:0% +they go on like that most important all +these objects don't depend on + + align:start position:0% +these objects don't depend on + + + align:start position:0% +these objects don't depend on +Lambda this the Lambda dependence is + + align:start position:0% +Lambda this the Lambda dependence is + + + align:start position:0% +Lambda this the Lambda dependence is +here Lambda Lambda squar Lambda on and + + align:start position:0% +here Lambda Lambda squar Lambda on and + + + align:start position:0% +here Lambda Lambda squar Lambda on and +these are things that don't depend on + + align:start position:0% +these are things that don't depend on + + + align:start position:0% +these are things that don't depend on +Lambda these are objects that have to be + + align:start position:0% +Lambda these are objects that have to be + + + align:start position:0% +Lambda these are objects that have to be +calculated they're all Lambda + + align:start position:0% +calculated they're all Lambda + + + align:start position:0% +calculated they're all Lambda +independent + + align:start position:0% +independent + + + align:start position:0% +independent +so we are supposed to solve this + + align:start position:0% +so we are supposed to solve this + + + align:start position:0% +so we are supposed to solve this +equation under this conditions and + + align:start position:0% +equation under this conditions and + + + align:start position:0% +equation under this conditions and +that's what we're going to do next \ No newline at end of file diff --git a/_crDeSDpB20.txt b/_crDeSDpB20.txt new file mode 100644 index 0000000000000000000000000000000000000000..07aa85f06db0a952cf70901292ecfaa0fc2e99f5 --- /dev/null +++ b/_crDeSDpB20.txt @@ -0,0 +1,9147 @@ +align:start position:0% + +um okay so today uh despite my + + align:start position:0% +um okay so today uh despite my + + + align:start position:0% +um okay so today uh despite my +admonition doesn't look like a very good + + align:start position:0% +admonition doesn't look like a very good + + + align:start position:0% +admonition doesn't look like a very good +attendance so I'm going to give you all + + align:start position:0% +attendance so I'm going to give you all + + + align:start position:0% +attendance so I'm going to give you all +the answers to the midterm just to + + align:start position:0% +the answers to the midterm just to + + + align:start position:0% +the answers to the midterm just to +reward you for I'm I'm joking but uh I'm + + align:start position:0% +reward you for I'm I'm joking but uh I'm + + + align:start position:0% +reward you for I'm I'm joking but uh I'm +glad you decided to come because it's a + + align:start position:0% +glad you decided to come because it's a + + + align:start position:0% +glad you decided to come because it's a +fun lecture and it's very relevant to + + align:start position:0% +fun lecture and it's very relevant to + + + align:start position:0% +fun lecture and it's very relevant to +what is going to be what we're going to + + align:start position:0% +what is going to be what we're going to + + + align:start position:0% +what is going to be what we're going to +be learning really for the next few + + align:start position:0% +be learning really for the next few + + + align:start position:0% +be learning really for the next few +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +which is thinking about models of + + align:start position:0% +which is thinking about models of + + + align:start position:0% +which is thinking about models of +oligopoly once again an awesome + + align:start position:0% +oligopoly once again an awesome + + + align:start position:0% +oligopoly once again an awesome +word which is really just a description + + align:start position:0% +word which is really just a description + + + align:start position:0% +word which is really just a description +of what most markets in America are so + + align:start position:0% +of what most markets in America are so + + + align:start position:0% +of what most markets in America are so +we've covered two extremes we've covered + + align:start position:0% +we've covered two extremes we've covered + + + align:start position:0% +we've covered two extremes we've covered +one extreme for markets which is perfect + + align:start position:0% +one extreme for markets which is perfect + + + align:start position:0% +one extreme for markets which is perfect +competition doesn't really exist we've + + align:start position:0% +competition doesn't really exist we've + + + align:start position:0% +competition doesn't really exist we've +covered another extreme which is + + align:start position:0% +covered another extreme which is + + + align:start position:0% +covered another extreme which is +Monopoly which is which does exist but + + align:start position:0% +Monopoly which is which does exist but + + + align:start position:0% +Monopoly which is which does exist but +it's still fairly rare the more common + + align:start position:0% +it's still fairly rare the more common + + + align:start position:0% +it's still fairly rare the more common +form of markets is what we call + + align:start position:0% +form of markets is what we call + + + align:start position:0% +form of markets is what we call +oligopoly which is when there's a small + + align:start position:0% +oligopoly which is when there's a small + + + align:start position:0% +oligopoly which is when there's a small +number of firms competing to provide the + + align:start position:0% +number of firms competing to provide the + + + align:start position:0% +number of firms competing to provide the +good so it's more than one firm so it's + + align:start position:0% +good so it's more than one firm so it's + + + align:start position:0% +good so it's more than one firm so it's +more than Monopoly but it's less than + + align:start position:0% +more than Monopoly but it's less than + + + align:start position:0% +more than Monopoly but it's less than +free entry it's less than a large number + + align:start position:0% +free entry it's less than a large number + + + align:start position:0% +free entry it's less than a large number +of firms driving profits to zero so + + align:start position:0% +of firms driving profits to zero so + + + align:start position:0% +of firms driving profits to zero so +let's see about the prototypical example + + align:start position:0% +let's see about the prototypical example + + + align:start position:0% +let's see about the prototypical example +of oligopolistic Industry the Auto + + align:start position:0% +of oligopolistic Industry the Auto + + + align:start position:0% +of oligopolistic Industry the Auto +industry most cars in America are sold + + align:start position:0% +industry most cars in America are sold + + + align:start position:0% +industry most cars in America are sold +by fewer than 20 + + align:start position:0% +by fewer than 20 + + + align:start position:0% +by fewer than 20 +companies but they're sold by well more + + align:start position:0% +companies but they're sold by well more + + + align:start position:0% +companies but they're sold by well more +than than one so if you drive on the + + align:start position:0% +than than one so if you drive on the + + + align:start position:0% +than than one so if you drive on the +road you see cars from you know + + align:start position:0% +road you see cars from you know + + + align:start position:0% +road you see cars from you know +primarily 10 but maybe even up to 20 + + align:start position:0% +primarily 10 but maybe even up to 20 + + + align:start position:0% +primarily 10 but maybe even up to 20 +different car + + align:start position:0% +different car + + + align:start position:0% +different car +companies so is that enough to drive us + + align:start position:0% +companies so is that enough to drive us + + + align:start position:0% +companies so is that enough to drive us +the perfectly competitive outcome that + + align:start position:0% +the perfectly competitive outcome that + + + align:start position:0% +the perfectly competitive outcome that +is those 10 to 20 car companies enough + + align:start position:0% +is those 10 to 20 car companies enough + + + align:start position:0% +is those 10 to 20 car companies enough +to drive us to zero + + align:start position:0% +to drive us to zero + + + align:start position:0% +to drive us to zero +profits probably not but is that enough + + align:start position:0% +profits probably not but is that enough + + + align:start position:0% +profits probably not but is that enough +that each company can simply set its + + align:start position:0% +that each company can simply set its + + + align:start position:0% +that each company can simply set its +price and pick its point on the demand + + align:start position:0% +price and pick its point on the demand + + + align:start position:0% +price and pick its point on the demand +curve probably not either so we're + + align:start position:0% +curve probably not either so we're + + + align:start position:0% +curve probably not either so we're +somewhere in between we're in an + + align:start position:0% +somewhere in between we're in an + + + align:start position:0% +somewhere in between we're in an +oligopolistic market now an + + align:start position:0% +oligopolistic market now an + + + align:start position:0% +oligopolistic market now an +oligopolistic Market firms can behave + + align:start position:0% +oligopolistic Market firms can behave + + + align:start position:0% +oligopolistic Market firms can behave +two ways they can behave cooperatively + + align:start position:0% +two ways they can behave cooperatively + + + align:start position:0% +two ways they can behave cooperatively +or non-cooperatively + + align:start position:0% +or non-cooperatively + + + align:start position:0% +or non-cooperatively +okay when there's one firm there's no + + align:start position:0% +okay when there's one firm there's no + + + align:start position:0% +okay when there's one firm there's no +issue just yourself when there's + + align:start position:0% +issue just yourself when there's + + + align:start position:0% +issue just yourself when there's +thousands of firms you can't figure out + + align:start position:0% +thousands of firms you can't figure out + + + align:start position:0% +thousands of firms you can't figure out +how to how to how to uh get together but + + align:start position:0% +how to how to how to uh get together but + + + align:start position:0% +how to how to how to uh get together but +when you have a small number of firms + + align:start position:0% +when you have a small number of firms + + + align:start position:0% +when you have a small number of firms +you can imagine behaving cooperatively + + align:start position:0% +you can imagine behaving cooperatively + + + align:start position:0% +you can imagine behaving cooperatively +non-cooperatively cooperatively would be + + align:start position:0% +non-cooperatively cooperatively would be + + + align:start position:0% +non-cooperatively cooperatively would be +to form a cartel so if you want to + + align:start position:0% +to form a cartel so if you want to + + + align:start position:0% +to form a cartel so if you want to +cooperate you form what's called a + + align:start position:0% +cooperate you form what's called a + + + align:start position:0% +cooperate you form what's called a +cartel which is a Cooperative + + align:start position:0% +cartel which is a Cooperative + + + align:start position:0% +cartel which is a Cooperative +organization of otherwise competing + + align:start position:0% +organization of otherwise competing + + + align:start position:0% +organization of otherwise competing +firms the classic example of this is + + align:start position:0% +firms the classic example of this is + + + align:start position:0% +firms the classic example of this is +OPEC the organization of petroleum + + align:start position:0% +OPEC the organization of petroleum + + + align:start position:0% +OPEC the organization of petroleum +exporting + + align:start position:0% +exporting + + + align:start position:0% +exporting +countries this organization formed in + + align:start position:0% +countries this organization formed in + + + align:start position:0% +countries this organization formed in +1970s of the Middle Eastern countries + + align:start position:0% +1970s of the Middle Eastern countries + + + align:start position:0% +1970s of the Middle Eastern countries +that responsible for about two-thirds of + + align:start position:0% +that responsible for about two-thirds of + + + align:start position:0% +that responsible for about two-thirds of +the world world's oil they got together + + align:start position:0% +the world world's oil they got together + + + align:start position:0% +the world world's oil they got together +and said let's produce + + align:start position:0% +and said let's produce + + + align:start position:0% +and said let's produce +cooperatively and we'll decide how much + + align:start position:0% +cooperatively and we'll decide how much + + + align:start position:0% +cooperatively and we'll decide how much +to produce and what price to set as if + + align:start position:0% +to produce and what price to set as if + + + align:start position:0% +to produce and what price to set as if +we were were sort of a collective + + align:start position:0% +we were were sort of a collective + + + align:start position:0% +we were were sort of a collective +Monopoly so in other words the idea of + + align:start position:0% +Monopoly so in other words the idea of + + + align:start position:0% +Monopoly so in other words the idea of +calization is you effectively turn + + align:start position:0% +calization is you effectively turn + + + align:start position:0% +calization is you effectively turn +yourself into a shared Monopoly with all + + align:start position:0% +yourself into a shared Monopoly with all + + + align:start position:0% +yourself into a shared Monopoly with all +the benefits we've talked about in terms + + align:start position:0% +the benefits we've talked about in terms + + + align:start position:0% +the benefits we've talked about in terms +of profits and + + align:start position:0% +of profits and + + + align:start position:0% +of profits and +things okay so basically the idea is + + align:start position:0% +things okay so basically the idea is + + + align:start position:0% +things okay so basically the idea is +look what do monopolies do they don't + + align:start position:0% +look what do monopolies do they don't + + + align:start position:0% +look what do monopolies do they don't +they get rid of competition they sort of + + align:start position:0% +they get rid of competition they sort of + + + align:start position:0% +they get rid of competition they sort of +maximize profits given the elasticity + + align:start position:0% +maximize profits given the elasticity + + + align:start position:0% +maximize profits given the elasticity +demand they face when you for a cartel + + align:start position:0% +demand they face when you for a cartel + + + align:start position:0% +demand they face when you for a cartel +you essentially say look let's do that + + align:start position:0% +you essentially say look let's do that + + + align:start position:0% +you essentially say look let's do that +let's get rid of competition let's just + + align:start position:0% +let's get rid of competition let's just + + + align:start position:0% +let's get rid of competition let's just +create a as big a piie as possible we'll + + align:start position:0% +create a as big a piie as possible we'll + + + align:start position:0% +create a as big a piie as possible we'll +figure out some way to split + + align:start position:0% +figure out some way to split + + + align:start position:0% +figure out some way to split +it okay now of course the Other Extreme + + align:start position:0% +it okay now of course the Other Extreme + + + align:start position:0% +it okay now of course the Other Extreme +is a + + align:start position:0% +is a + + + align:start position:0% +is a +non-cooperative oligopolistic market + + align:start position:0% +non-cooperative oligopolistic market + + + align:start position:0% +non-cooperative oligopolistic market +where firms don't get together and + + align:start position:0% +where firms don't get together and + + + align:start position:0% +where firms don't get together and +compete where firms where firms I'm + + align:start position:0% +compete where firms where firms I'm + + + align:start position:0% +compete where firms where firms I'm +sorry don't get together and agree um uh + + align:start position:0% +sorry don't get together and agree um uh + + + align:start position:0% +sorry don't get together and agree um uh +on what to do and in fact that's more + + align:start position:0% +on what to do and in fact that's more + + + align:start position:0% +on what to do and in fact that's more +realistic and we'll talk about reasons + + align:start position:0% +realistic and we'll talk about reasons + + + align:start position:0% +realistic and we'll talk about reasons +why next lecture next lecture we'll talk + + align:start position:0% +why next lecture next lecture we'll talk + + + align:start position:0% +why next lecture next lecture we'll talk +about how cartels work and why they + + align:start position:0% +about how cartels work and why they + + + align:start position:0% +about how cartels work and why they +don't typically + + align:start position:0% +don't typically + + + align:start position:0% +don't typically +last so today we'll focus on the more + + align:start position:0% +last so today we'll focus on the more + + + align:start position:0% +last so today we'll focus on the more +realistic case of a nonco + + align:start position:0% +realistic case of a nonco + + + align:start position:0% +realistic case of a nonco +Cooperative + + align:start position:0% + + + + align:start position:0% + +oligopoly which is when there's a small + + align:start position:0% +oligopoly which is when there's a small + + + align:start position:0% +oligopoly which is when there's a small +number of firms in an industry and they + + align:start position:0% +number of firms in an industry and they + + + align:start position:0% +number of firms in an industry and they +can't get together and and cooperate + + align:start position:0% +can't get together and and cooperate + + + align:start position:0% +can't get together and and cooperate +which makes sense I these are firms + + align:start position:0% +which makes sense I these are firms + + + align:start position:0% +which makes sense I these are firms +which grew up hating each other sort of + + align:start position:0% +which grew up hating each other sort of + + + align:start position:0% +which grew up hating each other sort of +makes sense it be hard to cooperate + + align:start position:0% +makes sense it be hard to cooperate + + + align:start position:0% +makes sense it be hard to cooperate +we'll talk about next time why that + + align:start position:0% +we'll talk about next time why that + + + align:start position:0% +we'll talk about next time why that +is so what do we + + align:start position:0% +is so what do we + + + align:start position:0% +is so what do we +do in that case well in that case things + + align:start position:0% +do in that case well in that case things + + + align:start position:0% +do in that case well in that case things +get + + align:start position:0% +get + + + align:start position:0% +get +hard the reason we start with perfect + + align:start position:0% +hard the reason we start with perfect + + + align:start position:0% +hard the reason we start with perfect +competition Monopoly is because they're + + align:start position:0% +competition Monopoly is because they're + + + align:start position:0% +competition Monopoly is because they're +relatively easy to think about oligopoly + + align:start position:0% +relatively easy to think about oligopoly + + + align:start position:0% +relatively easy to think about oligopoly +it gets super complicated and we have to + + align:start position:0% +it gets super complicated and we have to + + + align:start position:0% +it gets super complicated and we have to +turn to a new tool the tool of gain + + align:start position:0% + + + + align:start position:0% + +Theory + + align:start position:0% +Theory + + + align:start position:0% +Theory +okay um basically the idea of game + + align:start position:0% +okay um basically the idea of game + + + align:start position:0% +okay um basically the idea of game +theory is to think of these firms + + align:start position:0% +theory is to think of these firms + + + align:start position:0% +theory is to think of these firms +interacting as if they're playing a + + align:start position:0% +interacting as if they're playing a + + + align:start position:0% +interacting as if they're playing a +game think of there's there's n firms in + + align:start position:0% +game think of there's there's n firms in + + + align:start position:0% +game think of there's there's n firms in +a market where n is + + align:start position:0% +a market where n is + + + align:start position:0% +a market where n is +small they're they're sort of playing a + + align:start position:0% +small they're they're sort of playing a + + + align:start position:0% +small they're they're sort of playing a +game against each + + align:start position:0% +game against each + + + align:start position:0% +game against each +other and so there's two key pieces of + + align:start position:0% +other and so there's two key pieces of + + + align:start position:0% +other and so there's two key pieces of +Game Theory to keep track of think about + + align:start position:0% +Game Theory to keep track of think about + + + align:start position:0% +Game Theory to keep track of think about +playing a game what are sort of two + + align:start position:0% +playing a game what are sort of two + + + align:start position:0% +playing a game what are sort of two +things you want to figure out the first + + align:start position:0% +things you want to figure out the first + + + align:start position:0% +things you want to figure out the first +thing is your + + align:start position:0% +thing is your + + + align:start position:0% +thing is your +strategy what is the right strategy to + + align:start position:0% +strategy what is the right strategy to + + + align:start position:0% +strategy what is the right strategy to +win this + + align:start position:0% +win this + + + align:start position:0% +win this +game the second point you want to figure + + align:start position:0% +game the second point you want to figure + + + align:start position:0% +game the second point you want to figure +out is + + align:start position:0% +out is + + + align:start position:0% +out is +equilibrium when is the game over when + + align:start position:0% +equilibrium when is the game over when + + + align:start position:0% +equilibrium when is the game over when +does the game settle into an answer that + + align:start position:0% +does the game settle into an answer that + + + align:start position:0% +does the game settle into an answer that +all parties agree on with Monopoly + + align:start position:0% +all parties agree on with Monopoly + + + align:start position:0% +all parties agree on with Monopoly +there's a set of rules once everybody + + align:start position:0% +there's a set of rules once everybody + + + align:start position:0% +there's a set of rules once everybody +else is bankrupt you win that's the + + align:start position:0% +else is bankrupt you win that's the + + + align:start position:0% +else is bankrupt you win that's the +equilibrium okay so basically any game + + align:start position:0% +equilibrium okay so basically any game + + + align:start position:0% +equilibrium okay so basically any game +has a strategy and an equilibrium + + align:start position:0% +has a strategy and an equilibrium + + + align:start position:0% +has a strategy and an equilibrium +rule it turns + + align:start position:0% +rule it turns + + + align:start position:0% +rule it turns +out defining equilibrium in a rule with + + align:start position:0% +out defining equilibrium in a rule with + + + align:start position:0% +out defining equilibrium in a rule with +in a game with explicit rules is easy + + align:start position:0% +in a game with explicit rules is easy + + + align:start position:0% +in a game with explicit rules is easy +defining in a game where firms are just + + align:start position:0% +defining in a game where firms are just + + + align:start position:0% +defining in a game where firms are just +competing in this blood in a potentially + + align:start position:0% +competing in this blood in a potentially + + + align:start position:0% +competing in this blood in a potentially +bloodthirsty manner is not so easy and + + align:start position:0% +bloodthirsty manner is not so easy and + + + align:start position:0% +bloodthirsty manner is not so easy and +it turns out there is an enormous field + + align:start position:0% +it turns out there is an enormous field + + + align:start position:0% +it turns out there is an enormous field +in economics all about how do you think + + align:start position:0% +in economics all about how do you think + + + align:start position:0% +in economics all about how do you think +about equilibrium in game theoretic + + align:start position:0% +about equilibrium in game theoretic + + + align:start position:0% +about equilibrium in game theoretic +markets how do you think about when + + align:start position:0% +markets how do you think about when + + + align:start position:0% +markets how do you think about when +things finally settle down and end up + + align:start position:0% +things finally settle down and end up + + + align:start position:0% +things finally settle down and end up +and the most famous of these ideas of + + align:start position:0% +and the most famous of these ideas of + + + align:start position:0% +and the most famous of these ideas of +how to find equilibrium is what we call + + align:start position:0% +how to find equilibrium is what we call + + + align:start position:0% +how to find equilibrium is what we call +the Nash equilibrium any you guys ever + + align:start position:0% +the Nash equilibrium any you guys ever + + + align:start position:0% +the Nash equilibrium any you guys ever +see or read a beautiful + + align:start position:0% +see or read a beautiful + + + align:start position:0% +see or read a beautiful +mind that movie a little bit raise your + + align:start position:0% +mind that movie a little bit raise your + + + align:start position:0% +mind that movie a little bit raise your +hands yeah okay so a bunch of you saw it + + align:start position:0% +hands yeah okay so a bunch of you saw it + + + align:start position:0% +hands yeah okay so a bunch of you saw it +so it's about John Nash fascinating + + align:start position:0% +so it's about John Nash fascinating + + + align:start position:0% +so it's about John Nash fascinating +character um he was a mathematician + + align:start position:0% +character um he was a mathematician + + + align:start position:0% +character um he was a mathematician +brilliant + + align:start position:0% +brilliant + + + align:start position:0% +brilliant +mathematician uh who whose fundamental + + align:start position:0% +mathematician uh who whose fundamental + + + align:start position:0% +mathematician uh who whose fundamental +insight and if you see the movie this is + + align:start position:0% +insight and if you see the movie this is + + + align:start position:0% +insight and if you see the movie this is +so Illustrated well in a bar with the + + align:start position:0% +so Illustrated well in a bar with the + + + align:start position:0% +so Illustrated well in a bar with the +group of men are trying to pick up a + + align:start position:0% +group of men are trying to pick up a + + + align:start position:0% +group of men are trying to pick up a +group of women and again with this + + align:start position:0% +group of women and again with this + + + align:start position:0% +group of women and again with this +fundamental Insight that competition can + + align:start position:0% +fundamental Insight that competition can + + + align:start position:0% +fundamental Insight that competition can +be bad now if you think about economics + + align:start position:0% +be bad now if you think about economics + + + align:start position:0% +be bad now if you think about economics +we've learned everything we learn about + + align:start position:0% +we've learned everything we learn about + + + align:start position:0% +we've learned everything we learn about +competition is good competition is good + + align:start position:0% +competition is good competition is good + + + align:start position:0% +competition is good competition is good +it delivers better outcomes for + + align:start position:0% +it delivers better outcomes for + + + align:start position:0% +it delivers better outcomes for +consumers it reduces deadweight loss but + + align:start position:0% +consumers it reduces deadweight loss but + + + align:start position:0% +consumers it reduces deadweight loss but +he he actually came up with a theory + + align:start position:0% +he he actually came up with a theory + + + align:start position:0% +he he actually came up with a theory +that where actually in certain + + align:start position:0% +that where actually in certain + + + align:start position:0% +that where actually in certain +situations competition can be bad and + + align:start position:0% +situations competition can be bad and + + + align:start position:0% +situations competition can be bad and +cooperation can be better and that was + + align:start position:0% +cooperation can be better and that was + + + align:start position:0% +cooperation can be better and that was +sort of his fundamental insight + + align:start position:0% +sort of his fundamental insight + + + align:start position:0% +sort of his fundamental insight +okay and then he went insane + + align:start position:0% +okay and then he went insane + + + align:start position:0% +okay and then he went insane +unfortunately as can sometimes happen + + align:start position:0% +unfortunately as can sometimes happen + + + align:start position:0% +unfortunately as can sometimes happen +and the movie is sort of all about that + + align:start position:0% +and the movie is sort of all about that + + + align:start position:0% +and the movie is sort of all about that +it's very interesting it's a very + + align:start position:0% +it's very interesting it's a very + + + align:start position:0% +it's very interesting it's a very +interesting movie well acted interesting + + align:start position:0% +interesting movie well acted interesting + + + align:start position:0% +interesting movie well acted interesting +story about this poor guy who uh had + + align:start position:0% +story about this poor guy who uh had + + + align:start position:0% +story about this poor guy who uh had +these B insights and then and then + + align:start position:0% +these B insights and then and then + + + align:start position:0% +these B insights and then and then +developed mental illness severe + + align:start position:0% +developed mental illness severe + + + align:start position:0% +developed mental illness severe +schizophrenia um so what John Nash + + align:start position:0% +schizophrenia um so what John Nash + + + align:start position:0% +schizophrenia um so what John Nash +defined is the Nash equilibrium and the + + align:start position:0% +defined is the Nash equilibrium and the + + + align:start position:0% +defined is the Nash equilibrium and the +Nash equilibrium is defined as follows + + align:start position:0% +Nash equilibrium is defined as follows + + + align:start position:0% +Nash equilibrium is defined as follows +precisely a Nash equilibrium is the + + align:start position:0% +precisely a Nash equilibrium is the + + + align:start position:0% +precisely a Nash equilibrium is the +equilibrium where no player wants to + + align:start position:0% +equilibrium where no player wants to + + + align:start position:0% +equilibrium where no player wants to +change their + + align:start position:0% +change their + + + align:start position:0% +change their +strategy given all the other players + + align:start position:0% +strategy given all the other players + + + align:start position:0% +strategy given all the other players +strategies so you're an equilibrium + + align:start position:0% +strategies so you're an equilibrium + + + align:start position:0% +strategies so you're an equilibrium +where no player wants to change their + + align:start position:0% +where no player wants to change their + + + align:start position:0% +where no player wants to change their +strategy given all the other player + + align:start position:0% +strategy given all the other player + + + align:start position:0% +strategy given all the other player +strategies that is a Nash equilibrium + + align:start position:0% +strategies that is a Nash equilibrium + + + align:start position:0% +strategies that is a Nash equilibrium +that is formally if you hold all other + + align:start position:0% +that is formally if you hold all other + + + align:start position:0% +that is formally if you hold all other +players Behavior + + align:start position:0% +players Behavior + + + align:start position:0% +players Behavior +constant I can't do any better when I've + + align:start position:0% +constant I can't do any better when I've + + + align:start position:0% +constant I can't do any better when I've +reached that point I'm in equilibrium we + + align:start position:0% +reached that point I'm in equilibrium we + + + align:start position:0% +reached that point I'm in equilibrium we +reach to a point where I can't do any + + align:start position:0% +reach to a point where I can't do any + + + align:start position:0% +reach to a point where I can't do any +better holding everybody's strategies + + align:start position:0% +better holding everybody's strategies + + + align:start position:0% +better holding everybody's strategies +constant than I'm an equilibrium and the + + align:start position:0% +constant than I'm an equilibrium and the + + + align:start position:0% +constant than I'm an equilibrium and the +best example of this is example some of + + align:start position:0% +best example of this is example some of + + + align:start position:0% +best example of this is example some of +you may have heard about and you've + + align:start position:0% +you may have heard about and you've + + + align:start position:0% +you may have heard about and you've +certainly seen in movies the example the + + align:start position:0% +certainly seen in movies the example the + + + align:start position:0% +certainly seen in movies the example the +prisoners dilemma okay the prisoners + + align:start position:0% +prisoners dilemma okay the prisoners + + + align:start position:0% +prisoners dilemma okay the prisoners +dilemma is a famous movie device but + + align:start position:0% +dilemma is a famous movie device but + + + align:start position:0% +dilemma is a famous movie device but +almost a f example which is two guys are + + align:start position:0% +almost a f example which is two guys are + + + align:start position:0% +almost a f example which is two guys are +arrested for a crime it's not airtight + + align:start position:0% +arrested for a crime it's not airtight + + + align:start position:0% +arrested for a crime it's not airtight +that they did it they think the two guys + + align:start position:0% +that they did it they think the two guys + + + align:start position:0% +that they did it they think the two guys +did it but they really to really make it + + align:start position:0% +did it but they really to really make it + + + align:start position:0% +did it but they really to really make it +airtight + + align:start position:0% +airtight + + + align:start position:0% +airtight +they'd need them to admit it so let's + + align:start position:0% +they'd need them to admit it so let's + + + align:start position:0% +they'd need them to admit it so let's +say in this example and we'll give you + + align:start position:0% +say in this example and we'll give you + + + align:start position:0% +say in this example and we'll give you +examples like this and you'll need to + + align:start position:0% +examples like this and you'll need to + + + align:start position:0% +examples like this and you'll need to +think out interpret them so the example + + align:start position:0% +think out interpret them so the example + + + align:start position:0% +think out interpret them so the example +is two guys get arrested right now today + + align:start position:0% +is two guys get arrested right now today + + + align:start position:0% +is two guys get arrested right now today +there is enough evidence to send each of + + align:start position:0% +there is enough evidence to send each of + + + align:start position:0% +there is enough evidence to send each of +them to jail for one + + align:start position:0% +them to jail for one + + + align:start position:0% +them to jail for one +year okay enough just one year but if + + align:start position:0% +year okay enough just one year but if + + + align:start position:0% +year okay enough just one year but if +one guy squeals and says no the other + + align:start position:0% +one guy squeals and says no the other + + + align:start position:0% +one guy squeals and says no the other +guy did it if he turned States evidence + + align:start position:0% +guy did it if he turned States evidence + + + align:start position:0% +guy did it if he turned States evidence +whove learned a lot about this in the + + align:start position:0% +whove learned a lot about this in the + + + align:start position:0% +whove learned a lot about this in the +FBF trial and the upcoming Trump's trial + + align:start position:0% +FBF trial and the upcoming Trump's trial + + + align:start position:0% +FBF trial and the upcoming Trump's trial +okay the idea is if one person turn + + align:start position:0% +okay the idea is if one person turn + + + align:start position:0% +okay the idea is if one person turn +States evidence or squeals then they get + + align:start position:0% +States evidence or squeals then they get + + + align:start position:0% +States evidence or squeals then they get +zero they walk away and the other guy + + align:start position:0% +zero they walk away and the other guy + + + align:start position:0% +zero they walk away and the other guy +gets five + + align:start position:0% +gets five + + + align:start position:0% +gets five +years okay now if they both squeal they + + align:start position:0% +years okay now if they both squeal they + + + align:start position:0% +years okay now if they both squeal they +both get five years okay so basic the + + align:start position:0% +both get five years okay so basic the + + + align:start position:0% +both get five years okay so basic the +situation is if nothing happens they + + align:start position:0% +situation is if nothing happens they + + + align:start position:0% +situation is if nothing happens they +each get one year if either tells on the + + align:start position:0% +each get one year if either tells on the + + + align:start position:0% +each get one year if either tells on the +other person then the person they told + + align:start position:0% +other person then the person they told + + + align:start position:0% +other person then the person they told +on gets five years so what the way we + + align:start position:0% +on gets five years so what the way we + + + align:start position:0% +on gets five years so what the way we +analyze game theoretic situations like + + align:start position:0% +analyze game theoretic situations like + + + align:start position:0% +analyze game theoretic situations like +this is we write down we call a payoff + + align:start position:0% +this is we write down we call a payoff + + + align:start position:0% +this is we write down we call a payoff +Matrix so write down a payoff Matrix so + + align:start position:0% +Matrix so write down a payoff Matrix so + + + align:start position:0% +Matrix so write down a payoff Matrix so +the payoff Matrix look as follow you got + + align:start position:0% +the payoff Matrix look as follow you got + + + align:start position:0% +the payoff Matrix look as follow you got +prisoner + + align:start position:0% +prisoner + + + align:start position:0% +prisoner +a on the Y AIS here and prisoner + + align:start position:0% + + + + align:start position:0% + +B on the x- axis okay and you've got + + align:start position:0% +B on the x- axis okay and you've got + + + align:start position:0% +B on the x- axis okay and you've got +four + + align:start position:0% +four + + + align:start position:0% +four +situations okay in one case let's say + + align:start position:0% +situations okay in one case let's say + + + align:start position:0% +situations okay in one case let's say +prisoner + + align:start position:0% +prisoner + + + align:start position:0% +prisoner +a is + + align:start position:0% +a is + + + align:start position:0% +a is +silent he doesn't talk + + align:start position:0% +silent he doesn't talk + + + align:start position:0% +silent he doesn't talk +and prisoner B also stays silent they + + align:start position:0% +and prisoner B also stays silent they + + + align:start position:0% +and prisoner B also stays silent they +don't talk then in that case a gets one + + align:start position:0% +don't talk then in that case a gets one + + + align:start position:0% +don't talk then in that case a gets one +year and B gets one + + align:start position:0% + + + + align:start position:0% + +year now let's say that prisoner a stays + + align:start position:0% +year now let's say that prisoner a stays + + + align:start position:0% +year now let's say that prisoner a stays +silent but prisoner B talks prisoner B + + align:start position:0% +silent but prisoner B talks prisoner B + + + align:start position:0% +silent but prisoner B talks prisoner B +squeals then prisoner a now gets five + + align:start position:0% +squeals then prisoner a now gets five + + + align:start position:0% +squeals then prisoner a now gets five +years and prisoner b gets + + align:start position:0% + + + + align:start position:0% + +zero over here we have what if prisoner + + align:start position:0% +zero over here we have what if prisoner + + + align:start position:0% +zero over here we have what if prisoner +a talks well if prisoner a talks and + + align:start position:0% +a talks well if prisoner a talks and + + + align:start position:0% +a talks well if prisoner a talks and +prisoner B remains silent then prisoner + + align:start position:0% +prisoner B remains silent then prisoner + + + align:start position:0% +prisoner B remains silent then prisoner +a gets zero and prisoner b gets + + align:start position:0% +a gets zero and prisoner b gets + + + align:start position:0% +a gets zero and prisoner b gets +five but if they both talk they both get + + align:start position:0% + + + + align:start position:0% + +five okay questions about how I set up + + align:start position:0% +five okay questions about how I set up + + + align:start position:0% +five okay questions about how I set up +that Matrix given the words given the + + align:start position:0% +that Matrix given the words given the + + + align:start position:0% +that Matrix given the words given the +description of the problem you're going + + align:start position:0% +description of the problem you're going + + + align:start position:0% +description of the problem you're going +need to be able to take these descript + + align:start position:0% +need to be able to take these descript + + + align:start position:0% +need to be able to take these descript +set of matrices like this so any + + align:start position:0% +set of matrices like this so any + + + align:start position:0% +set of matrices like this so any +questions about how I did that + + align:start position:0% +questions about how I did that + + + align:start position:0% +questions about how I did that +okay now what we want to ask is what + + align:start position:0% +okay now what we want to ask is what + + + align:start position:0% +okay now what we want to ask is what +should each player do and the the sort + + align:start position:0% +should each player do and the the sort + + + align:start position:0% +should each player do and the the sort +of cheat in National equilibrium games + + align:start position:0% +of cheat in National equilibrium games + + + align:start position:0% +of cheat in National equilibrium games +the first step is to say look the + + align:start position:0% +the first step is to say look the + + + align:start position:0% +the first step is to say look the +easiest case would be if there is a + + align:start position:0% +easiest case would be if there is a + + + align:start position:0% +easiest case would be if there is a +dominant + + align:start position:0% + + + + align:start position:0% + +strategy if there's a dominant strategy + + align:start position:0% +strategy if there's a dominant strategy + + + align:start position:0% +strategy if there's a dominant strategy +is there one strategy which no matter + + align:start position:0% +is there one strategy which no matter + + + align:start position:0% +is there one strategy which no matter +what the other guy does you want to do + + align:start position:0% +what the other guy does you want to do + + + align:start position:0% +what the other guy does you want to do +then that's the Nash equilibrium right + + align:start position:0% +then that's the Nash equilibrium right + + + align:start position:0% +then that's the Nash equilibrium right +that's that's the outcome that you're + + align:start position:0% +that's that's the outcome that you're + + + align:start position:0% +that's that's the outcome that you're +going to do if there a strategy that's + + align:start position:0% +going to do if there a strategy that's + + + align:start position:0% +going to do if there a strategy that's +dominant that's the strategy you're + + align:start position:0% +dominant that's the strategy you're + + + align:start position:0% +dominant that's the strategy you're +going to + + align:start position:0% + + + + align:start position:0% + +play okay the best thing to do no matter + + align:start position:0% +play okay the best thing to do no matter + + + align:start position:0% +play okay the best thing to do no matter +what the other person + + align:start position:0% +what the other person + + + align:start position:0% +what the other person +does okay now if they could agree to + + align:start position:0% +does okay now if they could agree to + + + align:start position:0% +does okay now if they could agree to +cooperate if the two of them got + + align:start position:0% +cooperate if the two of them got + + + align:start position:0% +cooperate if the two of them got +together in a room beforehand and they + + align:start position:0% +together in a room beforehand and they + + + align:start position:0% +together in a room beforehand and they +trusted each other they could Rec + + align:start position:0% +trusted each other they could Rec + + + align:start position:0% +trusted each other they could Rec +cooperate then clearly what is the + + align:start position:0% +cooperate then clearly what is the + + + align:start position:0% +cooperate then clearly what is the +dominant coop operative + + align:start position:0% +dominant coop operative + + + align:start position:0% +dominant coop operative +strategy yeah they both stay silent they + + align:start position:0% +strategy yeah they both stay silent they + + + align:start position:0% +strategy yeah they both stay silent they +both get a + + align:start position:0% +both get a + + + align:start position:0% +both get a +year but let's say they can't do that + + align:start position:0% +year but let's say they can't do that + + + align:start position:0% +year but let's say they can't do that +they can't get in room together they + + align:start position:0% +they can't get in room together they + + + align:start position:0% +they can't get in room together they +never put in room together in the movies + + align:start position:0% +never put in room together in the movies + + + align:start position:0% +never put in room together in the movies +right they keep them separate and + + align:start position:0% +right they keep them separate and + + + align:start position:0% +right they keep them separate and +they're scummy criminals they don't + + align:start position:0% +they're scummy criminals they don't + + + align:start position:0% +they're scummy criminals they don't +trust each other okay so basically what + + align:start position:0% +trust each other okay so basically what + + + align:start position:0% +trust each other okay so basically what +happens now if you're prisoner a and + + align:start position:0% +happens now if you're prisoner a and + + + align:start position:0% +happens now if you're prisoner a and +you're not sure what prisoner B is going + + align:start position:0% +you're not sure what prisoner B is going + + + align:start position:0% +you're not sure what prisoner B is going +to + + align:start position:0% +to + + + align:start position:0% +to +do what should you do if you think + + align:start position:0% +do what should you do if you think + + + align:start position:0% +do what should you do if you think +prisoner B is going to stay + + align:start position:0% +prisoner B is going to stay + + + align:start position:0% +prisoner B is going to stay +silent yeah + + align:start position:0% +silent yeah + + + align:start position:0% +silent yeah +talk because your + + align:start position:0% +talk because your + + + align:start position:0% +talk because your +payoff is better what should you do if + + align:start position:0% +payoff is better what should you do if + + + align:start position:0% +payoff is better what should you do if +you think prisoner B is going to + + align:start position:0% +you think prisoner B is going to + + + align:start position:0% +you think prisoner B is going to +talk yeah talk because your payoff if + + align:start position:0% +talk yeah talk because your payoff if + + + align:start position:0% +talk yeah talk because your payoff if +you think prisoner B is going to talk + + align:start position:0% +you think prisoner B is going to talk + + + align:start position:0% +you think prisoner B is going to talk +then you should + + align:start position:0% +then you should + + + align:start position:0% +then you should +talk okay so I'm sorry I wrote I wrote + + align:start position:0% +talk okay so I'm sorry I wrote I wrote + + + align:start position:0% +talk okay so I'm sorry I wrote I wrote +this uh did I do this right yep I did + + align:start position:0% +this uh did I do this right yep I did + + + align:start position:0% +this uh did I do this right yep I did +this wrong that's what I did wrong it's + + align:start position:0% +this wrong that's what I did wrong it's + + + align:start position:0% +this wrong that's what I did wrong it's +no better if they both talk I say they + + align:start position:0% +no better if they both talk I say they + + + align:start position:0% +no better if they both talk I say they +both get three that makes more sense I + + align:start position:0% +both get three that makes more sense I + + + align:start position:0% +both get three that makes more sense I +set the example up wrong if they both + + align:start position:0% +set the example up wrong if they both + + + align:start position:0% +set the example up wrong if they both +talk they both get three that makes your + + align:start position:0% +talk they both get three that makes your + + + align:start position:0% +talk they both get three that makes your +answer is still right but this makes it + + align:start position:0% +answer is still right but this makes it + + + align:start position:0% +answer is still right but this makes it +non-binding that that involves + + align:start position:0% +non-binding that that involves + + + align:start position:0% +non-binding that that involves +inequality this is this is non-binding + + align:start position:0% +inequality this is this is non-binding + + + align:start position:0% +inequality this is this is non-binding +so clearly prisoner + + align:start position:0% +so clearly prisoner + + + align:start position:0% +so clearly prisoner +a is better off talking no matter what + + align:start position:0% +a is better off talking no matter what + + + align:start position:0% +a is better off talking no matter what +prisoner B is going to do what about + + align:start position:0% +prisoner B is going to do what about + + + align:start position:0% +prisoner B is going to do what about +prisoner B what's their dominant + + align:start position:0% +prisoner B what's their dominant + + + align:start position:0% +prisoner B what's their dominant +strategy yeah same thing it's a + + align:start position:0% +strategy yeah same thing it's a + + + align:start position:0% +strategy yeah same thing it's a +symmetric problem these problems won't + + align:start position:0% +symmetric problem these problems won't + + + align:start position:0% +symmetric problem these problems won't +always be symmetric but it's a hell of a + + align:start position:0% +always be symmetric but it's a hell of a + + + align:start position:0% +always be symmetric but it's a hell of a +lot easier when they are so you only + + align:start position:0% +lot easier when they are so you only + + + align:start position:0% +lot easier when they are so you only +have to solve for one person you assume + + align:start position:0% +have to solve for one person you assume + + + align:start position:0% +have to solve for one person you assume +the other other person does the same + + align:start position:0% +the other other person does the same + + + align:start position:0% +the other other person does the same +thing so prisoner B's dominant strategy + + align:start position:0% +thing so prisoner B's dominant strategy + + + align:start position:0% +thing so prisoner B's dominant strategy +is to talk so we have a situation where + + align:start position:0% +is to talk so we have a situation where + + + align:start position:0% +is to talk so we have a situation where +both dominant strategies align therefore + + align:start position:0% +both dominant strategies align therefore + + + align:start position:0% +both dominant strategies align therefore +we have an + + align:start position:0% +we have an + + + align:start position:0% +we have an +equilibrium and that equilibrium is what + + align:start position:0% +equilibrium and that equilibrium is what + + + align:start position:0% +equilibrium and that equilibrium is what +it's they both + + align:start position:0% +it's they both + + + align:start position:0% +it's they both +talk and they both get three + + align:start position:0% +talk and they both get three + + + align:start position:0% +talk and they both get three +years here's what's fascinating they are + + align:start position:0% +years here's what's fascinating they are + + + align:start position:0% +years here's what's fascinating they are +worse off than if they both stayed + + align:start position:0% +worse off than if they both stayed + + + align:start position:0% +worse off than if they both stayed +silent competition has yielded a worse + + align:start position:0% +silent competition has yielded a worse + + + align:start position:0% +silent competition has yielded a worse +outcome we haven't seen that before in + + align:start position:0% +outcome we haven't seen that before in + + + align:start position:0% +outcome we haven't seen that before in +this class + + align:start position:0% +this class + + + align:start position:0% +this class +competition in the sense of trying to do + + align:start position:0% +competition in the sense of trying to do + + + align:start position:0% +competition in the sense of trying to do +what's best for you at the expense of + + align:start position:0% +what's best for you at the expense of + + + align:start position:0% +what's best for you at the expense of +the other guy has yielded the worse + + align:start position:0% +the other guy has yielded the worse + + + align:start position:0% +the other guy has yielded the worse +outcome than + + align:start position:0% +outcome than + + + align:start position:0% +outcome than +cooperation that's what's incredibly + + align:start position:0% +cooperation that's what's incredibly + + + align:start position:0% +cooperation that's what's incredibly +Innovative about that's what Nash Nash + + align:start position:0% +Innovative about that's what Nash Nash + + + align:start position:0% +Innovative about that's what Nash Nash +even though being a mathematician won + + align:start position:0% +even though being a mathematician won + + + align:start position:0% +even though being a mathematician won +the Nobel prize in economics in Game + + align:start position:0% +the Nobel prize in economics in Game + + + align:start position:0% +the Nobel prize in economics in Game +Theory went from something which was + + align:start position:0% +Theory went from something which was + + + align:start position:0% +Theory went from something which was +kind of relatively new when I was a grad + + align:start position:0% +kind of relatively new when I was a grad + + + align:start position:0% +kind of relatively new when I was a grad +student in the late 80s to now being a + + align:start position:0% +student in the late 80s to now being a + + + align:start position:0% +student in the late 80s to now being a +quarter of the + + align:start position:0% +quarter of the + + + align:start position:0% +quarter of the +introductory uh training that graduate + + align:start position:0% +introductory uh training that graduate + + + align:start position:0% +introductory uh training that graduate +students PhD students in economics get + + align:start position:0% +students PhD students in economics get + + + align:start position:0% +students PhD students in economics get +game theory has become a dominant so to + + align:start position:0% +game theory has become a dominant so to + + + align:start position:0% +game theory has become a dominant so to +speak uh element of all economics + + align:start position:0% +speak uh element of all economics + + + align:start position:0% +speak uh element of all economics +training because it provides such a + + align:start position:0% +training because it provides such a + + + align:start position:0% +training because it provides such a +valuable tool for thinking about this so + + align:start position:0% +valuable tool for thinking about this so + + + align:start position:0% +valuable tool for thinking about this so +basically you end up with What's called + + align:start position:0% +basically you end up with What's called + + + align:start position:0% +basically you end up with What's called +the prisoners + + align:start position:0% +the prisoners + + + align:start position:0% +the prisoners +dilemma which is prisoners are each + + align:start position:0% +dilemma which is prisoners are each + + + align:start position:0% +dilemma which is prisoners are each +better off by ratting on the other and + + align:start position:0% +better off by ratting on the other and + + + align:start position:0% +better off by ratting on the other and +it ends up they both end up worse off + + align:start position:0% +it ends up they both end up worse off + + + align:start position:0% +it ends up they both end up worse off +and this also shows us how to solve a + + align:start position:0% +and this also shows us how to solve a + + + align:start position:0% +and this also shows us how to solve a +nash game a game with a Nash equilibrium + + align:start position:0% +nash game a game with a Nash equilibrium + + + align:start position:0% +nash game a game with a Nash equilibrium +which is you look for each player's + + align:start position:0% +which is you look for each player's + + + align:start position:0% +which is you look for each player's +dominant strategy + + align:start position:0% +dominant strategy + + + align:start position:0% +dominant strategy +and you find the point where they + + align:start position:0% +and you find the point where they + + + align:start position:0% +and you find the point where they +align the point where the two dominant + + align:start position:0% +align the point where the two dominant + + + align:start position:0% +align the point where the two dominant +strategies align is by definition an as + + align:start position:0% +strategies align is by definition an as + + + align:start position:0% +strategies align is by definition an as +equilibrium why because they're both + + align:start position:0% +equilibrium why because they're both + + + align:start position:0% +equilibrium why because they're both +doing the best they can giveing the + + align:start position:0% +doing the best they can giveing the + + + align:start position:0% +doing the best they can giveing the +other person now if the two dominant + + align:start position:0% +other person now if the two dominant + + + align:start position:0% +other person now if the two dominant +strategies don't align there may not be + + align:start position:0% +strategies don't align there may not be + + + align:start position:0% +strategies don't align there may not be +an + + align:start position:0% +an + + + align:start position:0% +an +equilibrium you have situations where + + align:start position:0% +equilibrium you have situations where + + + align:start position:0% +equilibrium you have situations where +A's dominant strategy different than B's + + align:start position:0% +A's dominant strategy different than B's + + + align:start position:0% +A's dominant strategy different than B's +Domin strategy they don't align then you + + align:start position:0% +Domin strategy they don't align then you + + + align:start position:0% +Domin strategy they don't align then you +might not get an equilibrium but in this + + align:start position:0% +might not get an equilibrium but in this + + + align:start position:0% +might not get an equilibrium but in this +case they align and most cases will give + + align:start position:0% +case they align and most cases will give + + + align:start position:0% +case they align and most cases will give +you they align so you get a Nash + + align:start position:0% +you they align so you get a Nash + + + align:start position:0% +you they align so you get a Nash +equilibrium where they both + + align:start position:0% +equilibrium where they both + + + align:start position:0% +equilibrium where they both +align okay + + align:start position:0% +align okay + + + align:start position:0% +align okay +now this is all cute and stuff but like + + align:start position:0% +now this is all cute and stuff but like + + + align:start position:0% +now this is all cute and stuff but like +this is a class about economics not + + align:start position:0% +this is a class about economics not + + + align:start position:0% +this is a class about economics not +about + + align:start position:0% +about + + + align:start position:0% +about +crime but it turns out the same logic + + align:start position:0% +crime but it turns out the same logic + + + align:start position:0% +crime but it turns out the same logic +applies to playing economic games so + + align:start position:0% +applies to playing economic games so + + + align:start position:0% +applies to playing economic games so +imagine let's take the market for soda + + align:start position:0% +imagine let's take the market for soda + + + align:start position:0% +imagine let's take the market for soda +and imagine there's two big players + + align:start position:0% +and imagine there's two big players + + + align:start position:0% +and imagine there's two big players +Pepsi and + + align:start position:0% +Pepsi and + + + align:start position:0% +Pepsi and +Coke and let's imagine there's a $16 + + align:start position:0% +Coke and let's imagine there's a $16 + + + align:start position:0% +Coke and let's imagine there's a $16 +billion soda + + align:start position:0% +billion soda + + + align:start position:0% +billion soda +Market let's further imagine that absent + + align:start position:0% +Market let's further imagine that absent + + + align:start position:0% +Market let's further imagine that absent +any advertising they would split it that + + align:start position:0% +any advertising they would split it that + + + align:start position:0% +any advertising they would split it that +with no advertising C and Pepsi would + + align:start position:0% +with no advertising C and Pepsi would + + + align:start position:0% +with no advertising C and Pepsi would +each get 8 billion + + align:start position:0% +each get 8 billion + + + align:start position:0% +each get 8 billion +out of the + + align:start position:0% +out of the + + + align:start position:0% +out of the +market + + align:start position:0% +market + + + align:start position:0% +market +but they can + + align:start position:0% +but they can + + + align:start position:0% +but they can +advertise adverti advertising costs five + + align:start position:0% +advertise adverti advertising costs five + + + align:start position:0% +advertise adverti advertising costs five +billion so if they advertise they only + + align:start position:0% +billion so if they advertise they only + + + align:start position:0% +billion so if they advertise they only +take home three billion + + align:start position:0% +take home three billion + + + align:start position:0% +take home three billion +net however if they advertise they drive + + align:start position:0% +net however if they advertise they drive + + + align:start position:0% +net however if they advertise they drive +the other guy out of the + + align:start position:0% +the other guy out of the + + + align:start position:0% +the other guy out of the +market so the choices don't advertise + + align:start position:0% +market so the choices don't advertise + + + align:start position:0% +market so the choices don't advertise +and split the market advertise in which + + align:start position:0% +and split the market advertise in which + + + align:start position:0% +and split the market advertise in which +case um if you um + + align:start position:0% +case um if you um + + + align:start position:0% +case um if you um +in which case if you advertise and you + + align:start position:0% +in which case if you advertise and you + + + align:start position:0% +in which case if you advertise and you +win the other guy's + + align:start position:0% +win the other guy's + + + align:start position:0% +win the other guy's +gone okay and you get you get the whole + + align:start position:0% +gone okay and you get you get the whole + + + align:start position:0% +gone okay and you get you get the whole +Market but if you don't advertise and + + align:start position:0% +Market but if you don't advertise and + + + align:start position:0% +Market but if you don't advertise and +you don't win and the other guy + + align:start position:0% +you don't win and the other guy + + + align:start position:0% +you don't win and the other guy +advertises you're gone so what that + + align:start position:0% +advertises you're gone so what that + + + align:start position:0% +advertises you're gone so what that +payoff Matrix look like well let's write + + align:start position:0% +payoff Matrix look like well let's write + + + align:start position:0% +payoff Matrix look like well let's write +that + + align:start position:0% +that + + + align:start position:0% +that +down you've + + align:start position:0% +down you've + + + align:start position:0% +down you've +got + + align:start position:0% +got + + + align:start position:0% +got +Coke and + + align:start position:0% + + + + align:start position:0% + +Pepsi Coke and Pepsi Coke can not + + align:start position:0% +Pepsi Coke and Pepsi Coke can not + + + align:start position:0% +Pepsi Coke and Pepsi Coke can not +advertise or + + align:start position:0% +advertise or + + + align:start position:0% +advertise or +advertise okay Pepsi cannot advertise or + + align:start position:0% +advertise okay Pepsi cannot advertise or + + + align:start position:0% +advertise okay Pepsi cannot advertise or +advertise if Coke and Pepsi both don't + + align:start position:0% +advertise if Coke and Pepsi both don't + + + align:start position:0% +advertise if Coke and Pepsi both don't +advertise they each get + + align:start position:0% + + + + align:start position:0% + +eight if Coke doesn't advertise and + + align:start position:0% +eight if Coke doesn't advertise and + + + align:start position:0% +eight if Coke doesn't advertise and +Pepsi does coke ends up with zero and + + align:start position:0% +Pepsi does coke ends up with zero and + + + align:start position:0% +Pepsi does coke ends up with zero and +Pepsi ends up with 11 which is the 16 is + + align:start position:0% +Pepsi ends up with 11 which is the 16 is + + + align:start position:0% +Pepsi ends up with 11 which is the 16 is +wrong in the notes by the way Andrew we + + align:start position:0% +wrong in the notes by the way Andrew we + + + align:start position:0% +wrong in the notes by the way Andrew we +should fix this um which is the 16 uh + + align:start position:0% +should fix this um which is the 16 uh + + + align:start position:0% +should fix this um which is the 16 uh +that they um the 16 that they got from + + align:start position:0% +that they um the 16 that they got from + + + align:start position:0% +that they um the 16 that they got from +having the market minus the five they + + align:start position:0% +having the market minus the five they + + + align:start position:0% +having the market minus the five they +spent in + + align:start position:0% +spent in + + + align:start position:0% +spent in +advertising on the other if Koke + + align:start position:0% +advertising on the other if Koke + + + align:start position:0% +advertising on the other if Koke +advertised and Pepsi doesn't then Koch + + align:start position:0% +advertised and Pepsi doesn't then Koch + + + align:start position:0% +advertised and Pepsi doesn't then Koch +gets 11 and Pepsi gets + + align:start position:0% +gets 11 and Pepsi gets + + + align:start position:0% +gets 11 and Pepsi gets +zero and if they both advertise Coke + + align:start position:0% +zero and if they both advertise Coke + + + align:start position:0% +zero and if they both advertise Coke +gets three and Pepsi gets + + align:start position:0% +gets three and Pepsi gets + + + align:start position:0% +gets three and Pepsi gets +three so once again the dominant + + align:start position:0% +three so once again the dominant + + + align:start position:0% +three so once again the dominant +cooperative strategy is they both don't + + align:start position:0% +cooperative strategy is they both don't + + + align:start position:0% +cooperative strategy is they both don't +advertise but the dominant + + align:start position:0% +advertise but the dominant + + + align:start position:0% +advertise but the dominant +non-cooperative strategy in each case is + + align:start position:0% +non-cooperative strategy in each case is + + + align:start position:0% +non-cooperative strategy in each case is +to advertise Koke is always better off + + align:start position:0% +to advertise Koke is always better off + + + align:start position:0% +to advertise Koke is always better off +if it + + align:start position:0% +if it + + + align:start position:0% +if it +advertises than if it doesn't Pepsi's + + align:start position:0% +advertises than if it doesn't Pepsi's + + + align:start position:0% +advertises than if it doesn't Pepsi's +always better off it advertises than it + + align:start position:0% +always better off it advertises than it + + + align:start position:0% +always better off it advertises than it +doesn't so they'll both advertise and + + align:start position:0% +doesn't so they'll both advertise and + + + align:start position:0% +doesn't so they'll both advertise and +you'll end up with both parties being + + align:start position:0% +you'll end up with both parties being + + + align:start position:0% +you'll end up with both parties being +worse off they just agreed not to + + align:start position:0% +worse off they just agreed not to + + + align:start position:0% +worse off they just agreed not to +advertise this is not an irrelevant + + align:start position:0% +advertise this is not an irrelevant + + + align:start position:0% +advertise this is not an irrelevant +example until about I don't know it's + + align:start position:0% +example until about I don't know it's + + + align:start position:0% +example until about I don't know it's +got to be about 10 years ago hard liquor + + align:start position:0% +got to be about 10 years ago hard liquor + + + align:start position:0% +got to be about 10 years ago hard liquor +you know whiskey vodka things like that + + align:start position:0% +you know whiskey vodka things like that + + + align:start position:0% +you know whiskey vodka things like that +never adverti on + + align:start position:0% +never adverti on + + + align:start position:0% +never adverti on +television now as a kid I thought that + + align:start position:0% +television now as a kid I thought that + + + align:start position:0% +television now as a kid I thought that +was a law but it turns out it wasn't it + + align:start position:0% +was a law but it turns out it wasn't it + + + align:start position:0% +was a law but it turns out it wasn't it +wasn't a law it was a Cooperative + + align:start position:0% +wasn't a law it was a Cooperative + + + align:start position:0% +wasn't a law it was a Cooperative +agreement among the manufacturer of hard + + align:start position:0% +agreement among the manufacturer of hard + + + align:start position:0% +agreement among the manufacturer of hard +liquor not to advertise on television + + align:start position:0% +liquor not to advertise on television + + + align:start position:0% +liquor not to advertise on television +they literally had reached the + + align:start position:0% +they literally had reached the + + + align:start position:0% +they literally had reached the +Cooperative equilibrium and then it + + align:start position:0% +Cooperative equilibrium and then it + + + align:start position:0% +Cooperative equilibrium and then it +broke down and now you see the ads on TV + + align:start position:0% +broke down and now you see the ads on TV + + + align:start position:0% +broke down and now you see the ads on TV +I don't know what be interesting I don't + + align:start position:0% +I don't know what be interesting I don't + + + align:start position:0% +I don't know what be interesting I don't +know what caused the broke down actually + + align:start position:0% +know what caused the broke down actually + + + align:start position:0% +know what caused the broke down actually +Andrew let's make a note I should do a + + align:start position:0% +Andrew let's make a note I should do a + + + align:start position:0% +Andrew let's make a note I should do a +case study on should add that that'd be + + align:start position:0% +case study on should add that that'd be + + + align:start position:0% +case study on should add that that'd be +good to add be be interesting to think + + align:start position:0% +good to add be be interesting to think + + + align:start position:0% +good to add be be interesting to think +about what caused that but they used to + + align:start position:0% +about what caused that but they used to + + + align:start position:0% +about what caused that but they used to +cooperate and they don't okay so B + + align:start position:0% +cooperate and they don't okay so B + + + align:start position:0% +cooperate and they don't okay so B +basically this an example of how the + + align:start position:0% +basically this an example of how the + + + align:start position:0% +basically this an example of how the +prisoner's dilemma can lead to a worse + + align:start position:0% +prisoner's dilemma can lead to a worse + + + align:start position:0% +prisoner's dilemma can lead to a worse +outcome questions about + + align:start position:0% + + + + align:start position:0% + +that okay this doesn't just + + align:start position:0% +that okay this doesn't just + + + align:start position:0% +that okay this doesn't just +apply to Coke and Pepsi or prisoners + + align:start position:0% +apply to Coke and Pepsi or prisoners + + + align:start position:0% +apply to Coke and Pepsi or prisoners +think about Andrew here let's say Andrew + + align:start position:0% +think about Andrew here let's say Andrew + + + align:start position:0% +think about Andrew here let's say Andrew +is in a new relationship still try to + + align:start position:0% +is in a new relationship still try to + + + align:start position:0% +is in a new relationship still try to +feel out the his partner okay and they + + align:start position:0% +feel out the his partner okay and they + + + align:start position:0% +feel out the his partner okay and they +have a + + align:start position:0% +have a + + + align:start position:0% +have a +fight and Andrew is thinking two things + + align:start position:0% +fight and Andrew is thinking two things + + + align:start position:0% +fight and Andrew is thinking two things +can happen I can go apolog oliz and I + + align:start position:0% +can happen I can go apolog oliz and I + + + align:start position:0% +can happen I can go apolog oliz and I +can go eat crow and say it's my fault + + align:start position:0% +can go eat crow and say it's my fault + + + align:start position:0% +can go eat crow and say it's my fault +let's say they're both at fault Andrew + + align:start position:0% +let's say they're both at fault Andrew + + + align:start position:0% +let's say they're both at fault Andrew +can say I can go eat crow and say it's + + align:start position:0% +can say I can go eat crow and say it's + + + align:start position:0% +can say I can go eat crow and say it's +my fault but then if my partners say + + align:start position:0% +my fault but then if my partners say + + + align:start position:0% +my fault but then if my partners say +it's their fault I'm GNA feel like + + align:start position:0% +it's their fault I'm GNA feel like + + + align:start position:0% +it's their fault I'm GNA feel like + the partner's thinking the same + + align:start position:0% + the partner's thinking the same + + + align:start position:0% + the partner's thinking the same +thing they' both be better off if they + + align:start position:0% +thing they' both be better off if they + + + align:start position:0% +thing they' both be better off if they +just apologize because they're both at + + align:start position:0% +just apologize because they're both at + + + align:start position:0% +just apologize because they're both at +fault but they both don't apologize + + align:start position:0% +fault but they both don't apologize + + + align:start position:0% +fault but they both don't apologize +because they don't want to look like the + + align:start position:0% +because they don't want to look like the + + + align:start position:0% +because they don't want to look like the +loser and they break + + align:start position:0% +loser and they break + + + align:start position:0% +loser and they break +up okay prison is a lemon action in + + align:start position:0% +up okay prison is a lemon action in + + + align:start position:0% +up okay prison is a lemon action in +personal + + align:start position:0% +personal + + + align:start position:0% +personal +relationships okay basically it's hard + + align:start position:0% +relationships okay basically it's hard + + + align:start position:0% +relationships okay basically it's hard +to form Cooperative relationships + + align:start position:0% +to form Cooperative relationships + + + align:start position:0% +to form Cooperative relationships +and non-cooperative equilibria can lead + + align:start position:0% +and non-cooperative equilibria can lead + + + align:start position:0% +and non-cooperative equilibria can lead +to bad + + align:start position:0% +to bad + + + align:start position:0% +to bad +outcomes okay now this is the very very + + align:start position:0% +outcomes okay now this is the very very + + + align:start position:0% +outcomes okay now this is the very very +tip of the incredibly exciting field of + + align:start position:0% +tip of the incredibly exciting field of + + + align:start position:0% +tip of the incredibly exciting field of +Game Theory Game Theory is a wonderful + + align:start position:0% +Game Theory Game Theory is a wonderful + + + align:start position:0% +Game Theory Game Theory is a wonderful +exciting field we have a great course + + align:start position:0% +exciting field we have a great course + + + align:start position:0% +exciting field we have a great course +called + + align:start position:0% +called + + + align:start position:0% +called +1412 which is Game Theory which takes + + align:start position:0% +1412 which is Game Theory which takes + + + align:start position:0% +1412 which is Game Theory which takes +this little bit as its first lecture and + + align:start position:0% +this little bit as its first lecture and + + + align:start position:0% +this little bit as its first lecture and +from there develops a whole semester of + + align:start position:0% +from there develops a whole semester of + + + align:start position:0% +from there develops a whole semester of +Game Theory you might say well how you + + align:start position:0% +Game Theory you might say well how you + + + align:start position:0% +Game Theory you might say well how you +do a whole semester well let me give you + + align:start position:0% +do a whole semester well let me give you + + + align:start position:0% +do a whole semester well let me give you +one + + align:start position:0% +one + + + align:start position:0% +one +example let me give you one example of + + align:start position:0% +example let me give you one example of + + + align:start position:0% +example let me give you one example of +how you can solve + + align:start position:0% +how you can solve + + + align:start position:0% +how you can solve +the prisoners dilemma without explicit + + align:start position:0% +the prisoners dilemma without explicit + + + align:start position:0% +the prisoners dilemma without explicit +cooperation how do you solve pris + + align:start position:0% +cooperation how do you solve pris + + + align:start position:0% +cooperation how do you solve pris +without explicit cooperation you can do + + align:start position:0% +without explicit cooperation you can do + + + align:start position:0% +without explicit cooperation you can do +it through playing a repeated + + align:start position:0% + + + + align:start position:0% + +game a repeated game so imagine the + + align:start position:0% +game a repeated game so imagine the + + + align:start position:0% +game a repeated game so imagine the +following imagine Coke and Pepsi play + + align:start position:0% +following imagine Coke and Pepsi play + + + align:start position:0% +following imagine Coke and Pepsi play +this game every year these is annual + + align:start position:0% +this game every year these is annual + + + align:start position:0% +this game every year these is annual +numbers play this game every year + + align:start position:0% +numbers play this game every year + + + align:start position:0% +numbers play this game every year +forever they play this game every year + + align:start position:0% +forever they play this game every year + + + align:start position:0% +forever they play this game every year +forever okay now imagine Coke says the + + align:start position:0% +forever okay now imagine Coke says the + + + align:start position:0% +forever okay now imagine Coke says the +following to Pepsi it's not it's not a + + align:start position:0% +following to Pepsi it's not it's not a + + + align:start position:0% +following to Pepsi it's not it's not a +cooperation it's it's a threat coch says + + align:start position:0% +cooperation it's it's a threat coch says + + + align:start position:0% +cooperation it's it's a threat coch says +to Pepsi I will not advertise as long as + + align:start position:0% +to Pepsi I will not advertise as long as + + + align:start position:0% +to Pepsi I will not advertise as long as +you don't + + align:start position:0% +you don't + + + align:start position:0% +you don't +advertise but the minute you advertise I + + align:start position:0% +advertise but the minute you advertise I + + + align:start position:0% +advertise but the minute you advertise I +will advertise + + align:start position:0% +will advertise + + + align:start position:0% +will advertise +forever so coke says to Pepsi I they + + align:start position:0% +forever so coke says to Pepsi I they + + + align:start position:0% +forever so coke says to Pepsi I they +start with no advertising Koke says I + + align:start position:0% +start with no advertising Koke says I + + + align:start position:0% +start with no advertising Koke says I +won't advertise you don't advertise but + + align:start position:0% +won't advertise you don't advertise but + + + align:start position:0% +won't advertise you don't advertise but +the minute you advertise I'll advertise + + align:start position:0% +the minute you advertise I'll advertise + + + align:start position:0% +the minute you advertise I'll advertise +forever now think about Pepsi's decision + + align:start position:0% +forever now think about Pepsi's decision + + + align:start position:0% +forever now think about Pepsi's decision +if Pepsi advertises in Period + + align:start position:0% +if Pepsi advertises in Period + + + align:start position:0% +if Pepsi advertises in Period +one in Period one they get the whole + + align:start position:0% +one in Period one they get the whole + + + align:start position:0% +one in Period one they get the whole +Market because kooch is committed to not + + align:start position:0% +Market because kooch is committed to not + + + align:start position:0% +Market because kooch is committed to not +advertise they get + + align:start position:0% +advertise they get + + + align:start position:0% +advertise they get +11 they get + + align:start position:0% +11 they get + + + align:start position:0% +11 they get +11 and then kooch says screw your + + align:start position:0% +11 and then kooch says screw your + + + align:start position:0% +11 and then kooch says screw your +advertising forever they get three plus + + align:start position:0% +advertising forever they get three plus + + + align:start position:0% +advertising forever they get three plus +three plus three plus dot do dot do + + align:start position:0% +three plus three plus dot do dot do + + + align:start position:0% +three plus three plus dot do dot do +dot what if Pepsi doesn't + + align:start position:0% + + + + align:start position:0% + +advertise then they get eight + + align:start position:0% + + + + align:start position:0% + +forever you don't to be a math genius to + + align:start position:0% +forever you don't to be a math genius to + + + align:start position:0% +forever you don't to be a math genius to +see this is a bigger + + align:start position:0% +see this is a bigger + + + align:start position:0% +see this is a bigger +number so it changes Pepsi's dominant + + align:start position:0% +number so it changes Pepsi's dominant + + + align:start position:0% +number so it changes Pepsi's dominant +strategy + + align:start position:0% +strategy + + + align:start position:0% +strategy +Koch simply issuing that threat changes + + align:start position:0% +Koch simply issuing that threat changes + + + align:start position:0% +Koch simply issuing that threat changes +the Domin strategy no cooperation here + + align:start position:0% +the Domin strategy no cooperation here + + + align:start position:0% +the Domin strategy no cooperation here +simply a threat and yet it enforces the + + align:start position:0% +simply a threat and yet it enforces the + + + align:start position:0% +simply a threat and yet it enforces the +Cooperative + + align:start position:0% +Cooperative + + + align:start position:0% +Cooperative +equilibrium but that doesn't work unless + + align:start position:0% +equilibrium but that doesn't work unless + + + align:start position:0% +equilibrium but that doesn't work unless +the game is + + align:start position:0% +the game is + + + align:start position:0% +the game is +infinite imagine that we know 100 years + + align:start position:0% +infinite imagine that we know 100 years + + + align:start position:0% +infinite imagine that we know 100 years +from now the US will ban soda and Coke + + align:start position:0% +from now the US will ban soda and Coke + + + align:start position:0% +from now the US will ban soda and Coke +and Pepsi know that they know at some + + align:start position:0% +and Pepsi know that they know at some + + + align:start position:0% +and Pepsi know that they know at some +point this game will end so do Market's + + align:start position:0% +point this game will end so do Market's + + + align:start position:0% +point this game will end so do Market's +going to go + + align:start position:0% +going to go + + + align:start position:0% +going to go +away what is Pepsi's optimal strategy in + + align:start position:0% +away what is Pepsi's optimal strategy in + + + align:start position:0% +away what is Pepsi's optimal strategy in +the 99th + + align:start position:0% + + + + align:start position:0% + +year yeah because last year it's the + + align:start position:0% +year yeah because last year it's the + + + align:start position:0% +year yeah because last year it's the +last year Coke can't punish him it's + + align:start position:0% +last year Coke can't punish him it's + + + align:start position:0% +last year Coke can't punish him it's +over but kooch knows that so what's + + align:start position:0% +over but kooch knows that so what's + + + align:start position:0% +over but kooch knows that so what's +Coke's optimal strategy in the 998th + + align:start position:0% +Coke's optimal strategy in the 998th + + + align:start position:0% +Coke's optimal strategy in the 998th +year advertise because I know Pepsi's + + align:start position:0% +year advertise because I know Pepsi's + + + align:start position:0% +year advertise because I know Pepsi's +can advertise in the 99th year they + + align:start position:0% +can advertise in the 99th year they + + + align:start position:0% +can advertise in the 99th year they +might as well get ahead of the game and + + align:start position:0% +might as well get ahead of the game and + + + align:start position:0% +might as well get ahead of the game and +advertise 998th year you can work + + align:start position:0% +advertise 998th year you can work + + + align:start position:0% +advertise 998th year you can work +backwards to see the game + + align:start position:0% +backwards to see the game + + + align:start position:0% +backwards to see the game +collapses from year one no will + + align:start position:0% +collapses from year one no will + + + align:start position:0% +collapses from year one no will +play because they know working backwards + + align:start position:0% +play because they know working backwards + + + align:start position:0% +play because they know working backwards +that as soon as someone commits not to + + align:start position:0% +that as soon as someone commits not to + + + align:start position:0% +that as soon as someone commits not to +advertise they're going to advertise and + + align:start position:0% +advertise they're going to advertise and + + + align:start position:0% +advertise they're going to advertise and +then just going to advertise + + align:start position:0% +then just going to advertise + + + align:start position:0% +then just going to advertise +forever so here's a solution that works + + align:start position:0% +forever so here's a solution that works + + + align:start position:0% +forever so here's a solution that works +but only under particular conditions + + align:start position:0% +but only under particular conditions + + + align:start position:0% +but only under particular conditions +which is an infinite repeated + + align:start position:0% +which is an infinite repeated + + + align:start position:0% +which is an infinite repeated +game that's pretty + + align:start position:0% +game that's pretty + + + align:start position:0% +game that's pretty +cool okay and that is once again the + + align:start position:0% +cool okay and that is once again the + + + align:start position:0% +cool okay and that is once again the +kind of things you could think about + + align:start position:0% +kind of things you could think about + + + align:start position:0% +kind of things you could think about +with the tools of Game Theory what 1412 + + align:start position:0% +with the tools of Game Theory what 1412 + + + align:start position:0% +with the tools of Game Theory what 1412 +does is show you how to mathematically + + align:start position:0% +does is show you how to mathematically + + + align:start position:0% +does is show you how to mathematically +to prove these things how think about + + align:start position:0% +to prove these things how think about + + + align:start position:0% +to prove these things how think about +all the cool games it depends on who has + + align:start position:0% +all the cool games it depends on who has + + + align:start position:0% +all the cool games it depends on who has +what information who has what bargaining + + align:start position:0% +what information who has what bargaining + + + align:start position:0% +what information who has what bargaining +strength there's all sorts of cool stuff + + align:start position:0% +strength there's all sorts of cool stuff + + + align:start position:0% +strength there's all sorts of cool stuff +that comes into play here + + align:start position:0% + + + + align:start position:0% + +yeah don't know it's not but you don't + + align:start position:0% +yeah don't know it's not but you don't + + + align:start position:0% +yeah don't know it's not but you don't +know that + + align:start position:0% + + + + align:start position:0% + +stop you know I I think I think that's + + align:start position:0% +stop you know I I think I think that's + + + align:start position:0% +stop you know I I think I think that's +my I should have saved my whiskey + + align:start position:0% +my I should have saved my whiskey + + + align:start position:0% +my I should have saved my whiskey +example for this which is + + align:start position:0% +example for this which is + + + align:start position:0% +example for this which is +somehow the whiskey companies had + + align:start position:0% +somehow the whiskey companies had + + + align:start position:0% +somehow the whiskey companies had +decided they were playing this repeated + + align:start position:0% +decided they were playing this repeated + + + align:start position:0% +decided they were playing this repeated +equilibrium this this repeated game and + + align:start position:0% +equilibrium this this repeated game and + + + align:start position:0% +equilibrium this this repeated game and +somehow it broke down now I don't know + + align:start position:0% +somehow it broke down now I don't know + + + align:start position:0% +somehow it broke down now I don't know +what broke did they suddenly think G + + align:start position:0% +what broke did they suddenly think G + + + align:start position:0% +what broke did they suddenly think G +people losing their taste for hard + + align:start position:0% +people losing their taste for hard + + + align:start position:0% +people losing their taste for hard +liquor we better get you know get get it + + align:start position:0% +liquor we better get you know get get it + + + align:start position:0% +liquor we better get you know get get it +while it's good I don't know it's a good + + align:start position:0% +while it's good I don't know it's a good + + + align:start position:0% +while it's good I don't know it's a good +question but in reality sometimes it + + align:start position:0% +question but in reality sometimes it + + + align:start position:0% +question but in reality sometimes it +works sometimes it doesn't and that's + + align:start position:0% +works sometimes it doesn't and that's + + + align:start position:0% +works sometimes it doesn't and that's +what is exciting about game theory is to + + align:start position:0% +what is exciting about game theory is to + + + align:start position:0% +what is exciting about game theory is to +think about deriving the conditions + + align:start position:0% +think about deriving the conditions + + + align:start position:0% +think about deriving the conditions +under which it's likely to work and not + + align:start position:0% +under which it's likely to work and not + + + align:start position:0% +under which it's likely to work and not +likely to work good question other + + align:start position:0% +likely to work good question other + + + align:start position:0% +likely to work good question other +questions so that's game theory in a in + + align:start position:0% +questions so that's game theory in a in + + + align:start position:0% +questions so that's game theory in a in +a big uh sort of in a in in in in a + + align:start position:0% +a big uh sort of in a in in in in a + + + align:start position:0% +a big uh sort of in a in in in in a +nutshell okay what we're going to do now + + align:start position:0% +nutshell okay what we're going to do now + + + align:start position:0% +nutshell okay what we're going to do now +is move from this vague concept of Game + + align:start position:0% +is move from this vague concept of Game + + + align:start position:0% +is move from this vague concept of Game +Theory to a particular model a + + align:start position:0% +Theory to a particular model a + + + align:start position:0% +Theory to a particular model a +particular game theoretic model and + + align:start position:0% +particular game theoretic model and + + + align:start position:0% +particular game theoretic model and +that's the model we'll focus on in this + + align:start position:0% +that's the model we'll focus on in this + + + align:start position:0% +that's the model we'll focus on in this +class as the model of non-cooperative + + align:start position:0% +class as the model of non-cooperative + + + align:start position:0% +class as the model of non-cooperative +oligopoly but I'm going to tell you it's + + align:start position:0% +oligopoly but I'm going to tell you it's + + + align:start position:0% +oligopoly but I'm going to tell you it's +one model of an enormous class of models + + align:start position:0% +one model of an enormous class of models + + + align:start position:0% +one model of an enormous class of models +it's just a models particularly + + align:start position:0% +it's just a models particularly + + + align:start position:0% +it's just a models particularly +convenient to work with and it gives the + + align:start position:0% +convenient to work with and it gives the + + + align:start position:0% +convenient to work with and it gives the +intuition without the math being too + + align:start position:0% +intuition without the math being too + + + align:start position:0% +intuition without the math being too +hard okay so we're going to move to one + + align:start position:0% +hard okay so we're going to move to one + + + align:start position:0% +hard okay so we're going to move to one +particular model but recognize the model + + align:start position:0% +particular model but recognize the model + + + align:start position:0% +particular model but recognize the model +we're using is one of a class of models + + align:start position:0% +we're using is one of a class of models + + + align:start position:0% +we're using is one of a class of models +one could use to model non Cooperative + + align:start position:0% +one could use to model non Cooperative + + + align:start position:0% +one could use to model non Cooperative +oligopolistic equilibria that may be the + + align:start position:0% +oligopolistic equilibria that may be the + + + align:start position:0% +oligopolistic equilibria that may be the +most complicated three words I'll use + + align:start position:0% +most complicated three words I'll use + + + align:start position:0% +most complicated three words I'll use +together in this class non-cooperative + + align:start position:0% +together in this class non-cooperative + + + align:start position:0% +together in this class non-cooperative +oligopolistic equilibria okay so we're + + align:start position:0% +oligopolistic equilibria okay so we're + + + align:start position:0% +oligopolistic equilibria okay so we're +going to talk + + align:start position:0% +going to talk + + + align:start position:0% +going to talk +about the Corno + + align:start position:0% + + + + align:start position:0% + +model of non-cooperative equilibria this + + align:start position:0% +model of non-cooperative equilibria this + + + align:start position:0% +model of non-cooperative equilibria this +is basically a version of the Nash + + align:start position:0% +is basically a version of the Nash + + + align:start position:0% +is basically a version of the Nash +model okay so what we're going to do is + + align:start position:0% +model okay so what we're going to do is + + + align:start position:0% +model okay so what we're going to do is +we're going to take the general Nash + + align:start position:0% +we're going to take the general Nash + + + align:start position:0% +we're going to take the general Nash +model and we're going to enrich it + + align:start position:0% +model and we're going to enrich it + + + align:start position:0% +model and we're going to enrich it +saying beyond having two choices you + + align:start position:0% +saying beyond having two choices you + + + align:start position:0% +saying beyond having two choices you +have a whole schedule of choices your + + align:start position:0% +have a whole schedule of choices your + + + align:start position:0% +have a whole schedule of choices your +choice isn't just a versus B but there's + + align:start position:0% +choice isn't just a versus B but there's + + + align:start position:0% +choice isn't just a versus B but there's +a large set of choices you can make + + align:start position:0% +a large set of choices you can make + + + align:start position:0% +a large set of choices you can make +which is true in economic context + + align:start position:0% +which is true in economic context + + + align:start position:0% +which is true in economic context +usually not a versus B there's how much + + align:start position:0% +usually not a versus B there's how much + + + align:start position:0% +usually not a versus B there's how much +you're going to advertise Etc there's + + align:start position:0% +you're going to advertise Etc there's + + + align:start position:0% +you're going to advertise Etc there's +whole set of choices you can make and + + align:start position:0% +whole set of choices you can make and + + + align:start position:0% +whole set of choices you can make and +but we're still going to consider two + + align:start position:0% +but we're still going to consider two + + + align:start position:0% +but we're still going to consider two +firms playing because it gets really + + align:start position:0% +firms playing because it gets really + + + align:start position:0% +firms playing because it gets really +messy Beyond two firms although once + + align:start position:0% +messy Beyond two firms although once + + + align:start position:0% +messy Beyond two firms although once +they get 142 I'll teach you how to + + align:start position:0% +they get 142 I'll teach you how to + + + align:start position:0% +they get 142 I'll teach you how to +handle that so let's imagine the world + + align:start position:0% +handle that so let's imagine the world + + + align:start position:0% +handle that so let's imagine the world +of + + align:start position:0% +of + + + align:start position:0% +of +flights from New York to + + align:start position:0% +flights from New York to + + + align:start position:0% +flights from New York to +Chicago okay and let's imagine due to + + align:start position:0% +Chicago okay and let's imagine due to + + + align:start position:0% +Chicago okay and let's imagine due to +the hub and spoke problem we discussed + + align:start position:0% +the hub and spoke problem we discussed + + + align:start position:0% +the hub and spoke problem we discussed +last time there's only two firms that + + align:start position:0% +last time there's only two firms that + + + align:start position:0% +last time there's only two firms that +fly New York to Chicago United and + + align:start position:0% +fly New York to Chicago United and + + + align:start position:0% +fly New York to Chicago United and +American obviously there's more than + + align:start position:0% +American obviously there's more than + + + align:start position:0% +American obviously there's more than +that but just to make this example easy + + align:start position:0% +that but just to make this example easy + + + align:start position:0% +that but just to make this example easy +imagine only two firms that fly to these + + align:start position:0% +imagine only two firms that fly to these + + + align:start position:0% +imagine only two firms that fly to these +two firms do dominate the market to + + align:start position:0% +two firms do dominate the market to + + + align:start position:0% +two firms do dominate the market to +Chicago 90% of flight to Chicago one or + + align:start position:0% +Chicago 90% of flight to Chicago one or + + + align:start position:0% +Chicago 90% of flight to Chicago one or +the other of those so let's say that + + align:start position:0% +the other of those so let's say that + + + align:start position:0% +the other of those so let's say that +that these two firms the only firms in + + align:start position:0% +that these two firms the only firms in + + + align:start position:0% +that these two firms the only firms in +the + + align:start position:0% +the + + + align:start position:0% +the +market and now we want to ask how does + + align:start position:0% +market and now we want to ask how does + + + align:start position:0% +market and now we want to ask how does +each firm KN the other firms out there + + align:start position:0% +each firm KN the other firms out there + + + align:start position:0% +each firm KN the other firms out there +how does each firm decide on what price + + align:start position:0% +how does each firm decide on what price + + + align:start position:0% +how does each firm decide on what price +to set and how many flights to run to do + + align:start position:0% +to set and how many flights to run to do + + + align:start position:0% +to set and how many flights to run to do +that we are going to set up the Coro + + align:start position:0% +that we are going to set up the Coro + + + align:start position:0% +that we are going to set up the Coro +model and the Coro model is going to say + + align:start position:0% +model and the Coro model is going to say + + + align:start position:0% +model and the Coro model is going to say +we're going to look for the Nash + + align:start position:0% +we're going to look for the Nash + + + align:start position:0% +we're going to look for the Nash +equilibrium but in terms of set of + + align:start position:0% +equilibrium but in terms of set of + + + align:start position:0% +equilibrium but in terms of set of +phrasing in a vague term like dominant + + align:start position:0% +phrasing in a vague term like dominant + + + align:start position:0% +phrasing in a vague term like dominant +strategy will phrase the Nash + + align:start position:0% +strategy will phrase the Nash + + + align:start position:0% +strategy will phrase the Nash +equilibrium as follows this is a long + + align:start position:0% +equilibrium as follows this is a long + + + align:start position:0% +equilibrium as follows this is a long +sentence so bear with me the keno + + align:start position:0% +sentence so bear with me the keno + + + align:start position:0% +sentence so bear with me the keno +equilibrium is the set of + + align:start position:0% +equilibrium is the set of + + + align:start position:0% +equilibrium is the set of +quantities for each firm so such that + + align:start position:0% +quantities for each firm so such that + + + align:start position:0% +quantities for each firm so such that +holding other firms quantities + + align:start position:0% + + + + align:start position:0% + +constant no firm can obtain a higher a + + align:start position:0% +constant no firm can obtain a higher a + + + align:start position:0% +constant no firm can obtain a higher a +higher profit by deviating say it again + + align:start position:0% +higher profit by deviating say it again + + + align:start position:0% +higher profit by deviating say it again +the set of quantities for each firm such + + align:start position:0% +the set of quantities for each firm such + + + align:start position:0% +the set of quantities for each firm such +that holding every other firm's quantity + + align:start position:0% +that holding every other firm's quantity + + + align:start position:0% +that holding every other firm's quantity +constant no firm can raise their profits + + align:start position:0% +constant no firm can raise their profits + + + align:start position:0% +constant no firm can raise their profits +by + + align:start position:0% +by + + + align:start position:0% +by +deviating so it's a schedule a set of + + align:start position:0% +deviating so it's a schedule a set of + + + align:start position:0% +deviating so it's a schedule a set of +quantities a schedule of quantities that + + align:start position:0% +quantities a schedule of quantities that + + + align:start position:0% +quantities a schedule of quantities that +sort of maps out your dominant strategy + + align:start position:0% +sort of maps out your dominant strategy + + + align:start position:0% +sort of maps out your dominant strategy +it's not like there's one dominant + + align:start position:0% +it's not like there's one dominant + + + align:start position:0% +it's not like there's one dominant +strategy there a dominant schedule of + + align:start position:0% +strategy there a dominant schedule of + + + align:start position:0% +strategy there a dominant schedule of +strategies to see that let's go to + + align:start position:0% +strategies to see that let's go to + + + align:start position:0% +strategies to see that let's go to +figure 131 this is an example of the + + align:start position:0% +figure 131 this is an example of the + + + align:start position:0% +figure 131 this is an example of the +kind of figure you're going to become + + align:start position:0% +kind of figure you're going to become + + + align:start position:0% +kind of figure you're going to become +familiar with over the next few + + align:start position:0% +familiar with over the next few + + + align:start position:0% +familiar with over the next few +lectures figure 131 shows the market for + + align:start position:0% +lectures figure 131 shows the market for + + + align:start position:0% +lectures figure 131 shows the market for +American Airlines as if it was a + + align:start position:0% +American Airlines as if it was a + + + align:start position:0% +American Airlines as if it was a +monopoly imagine American downside a + + align:start position:0% +monopoly imagine American downside a + + + align:start position:0% +monopoly imagine American downside a +monopoly and imagine we're going to + + align:start position:0% +monopoly and imagine we're going to + + + align:start position:0% +monopoly and imagine we're going to +write down arbitrarily that the demand + + align:start position:0% +write down arbitrarily that the demand + + + align:start position:0% +write down arbitrarily that the demand +curve for flights to Chicago + + align:start position:0% +curve for flights to Chicago + + + align:start position:0% +curve for flights to Chicago +is 339 minus Q where Q is the total + + align:start position:0% +is 339 minus Q where Q is the total + + + align:start position:0% +is 339 minus Q where Q is the total +number of flights that's the demand + + align:start position:0% +number of flights that's the demand + + + align:start position:0% +number of flights that's the demand +curve for flights to Chicago just arbitr + + align:start position:0% +curve for flights to Chicago just arbitr + + + align:start position:0% +curve for flights to Chicago just arbitr +written + + align:start position:0% +written + + + align:start position:0% +written +down and let's say further that + + align:start position:0% +down and let's say further that + + + align:start position:0% +down and let's say further that +arbitrarily that marginal cost equals + + align:start position:0% +arbitrarily that marginal cost equals + + + align:start position:0% +arbitrarily that marginal cost equals +$147 so it's 339 minus Q's demand + + align:start position:0% +$147 so it's 339 minus Q's demand + + + align:start position:0% +$147 so it's 339 minus Q's demand +marginal cost + + align:start position:0% +marginal cost + + + align:start position:0% +marginal cost +147 so what would a monopolis do well + + align:start position:0% +147 so what would a monopolis do well + + + align:start position:0% +147 so what would a monopolis do well +good practice for yall for tomorrow + + align:start position:0% +good practice for yall for tomorrow + + + align:start position:0% +good practice for yall for tomorrow +night what would a monopolis do + + align:start position:0% +night what would a monopolis do + + + align:start position:0% +night what would a monopolis do +monopolis would set marginal revenue to + + align:start position:0% +monopolis would set marginal revenue to + + + align:start position:0% +monopolis would set marginal revenue to +marginal cost well what's revenue + + align:start position:0% +marginal cost well what's revenue + + + align:start position:0% +marginal cost well what's revenue +revenue is + + align:start position:0% +revenue is + + + align:start position:0% +revenue is +339 Q - Q ^2 what's marginal revenue 339 + + align:start position:0% +339 Q - Q ^2 what's marginal revenue 339 + + + align:start position:0% +339 Q - Q ^2 what's marginal revenue 339 +minus 2 Q so monopolis sets marginal + + align:start position:0% +minus 2 Q so monopolis sets marginal + + + align:start position:0% +minus 2 Q so monopolis sets marginal +revenue 339 - 2q equal to marginal cost + + align:start position:0% +revenue 339 - 2q equal to marginal cost + + + align:start position:0% +revenue 339 - 2q equal to marginal cost +which is + + align:start position:0% +which is + + + align:start position:0% +which is +147 and you get that the alha Monopoly + + align:start position:0% +147 and you get that the alha Monopoly + + + align:start position:0% +147 and you get that the alha Monopoly +quantity + + align:start position:0% +quantity + + + align:start position:0% +quantity +qm is 90 is + + align:start position:0% +qm is 90 is + + + align:start position:0% +qm is 90 is +um qm is 96 + + align:start position:0% +um qm is 96 + + + align:start position:0% +um qm is 96 +flights and the optimal price is + + align:start position:0% + + + + align:start position:0% + +$243 we get the optimal quantity by + + align:start position:0% +$243 we get the optimal quantity by + + + align:start position:0% +$243 we get the optimal quantity by +solving this equation get the opal chice + + align:start position:0% +solving this equation get the opal chice + + + align:start position:0% +solving this equation get the opal chice +by plugging that back in the demand + + align:start position:0% +by plugging that back in the demand + + + align:start position:0% +by plugging that back in the demand +equation so if this is a monopoly this + + align:start position:0% +equation so if this is a monopoly this + + + align:start position:0% +equation so if this is a monopoly this +is what they're going to do note of + + align:start position:0% +is what they're going to do note of + + + align:start position:0% +is what they're going to do note of +course that price is well above marginal + + align:start position:0% +course that price is well above marginal + + + align:start position:0% +course that price is well above marginal +cost because it's a monopoly there's a + + align:start position:0% +cost because it's a monopoly there's a + + + align:start position:0% +cost because it's a monopoly there's a +markup okay so that's what they would + + align:start position:0% +markup okay so that's what they would + + + align:start position:0% +markup okay so that's what they would +and we could see that in figure 131 by + + align:start position:0% +and we could see that in figure 131 by + + + align:start position:0% +and we could see that in figure 131 by +drawing the monopolis problem you see + + align:start position:0% +drawing the monopolis problem you see + + + align:start position:0% +drawing the monopolis problem you see +the marginal cost is at + + align:start position:0% +the marginal cost is at + + + align:start position:0% +the marginal cost is at +147 you see the the main curve is the + + align:start position:0% +147 you see the the main curve is the + + + align:start position:0% +147 you see the the main curve is the +Blue + + align:start position:0% +Blue + + + align:start position:0% +Blue +Line the marginal revenue curve is the + + align:start position:0% +Line the marginal revenue curve is the + + + align:start position:0% +Line the marginal revenue curve is the +red downward sloping line the maroon + + align:start position:0% +red downward sloping line the maroon + + + align:start position:0% +red downward sloping line the maroon +line the darker red line we find the + + align:start position:0% +line the darker red line we find the + + + align:start position:0% +line the darker red line we find the +point where marginal revenue intersects + + align:start position:0% +point where marginal revenue intersects + + + align:start position:0% +point where marginal revenue intersects +marginal cost which is at 96 flights + + align:start position:0% +marginal cost which is at 96 flights + + + align:start position:0% +marginal cost which is at 96 flights +96,000 + + align:start position:0% +96,000 + + + align:start position:0% +96,000 +whatever and then to find the price we + + align:start position:0% +whatever and then to find the price we + + + align:start position:0% +whatever and then to find the price we +read it off the demand curve which is + + align:start position:0% +read it off the demand curve which is + + + align:start position:0% +read it off the demand curve which is +the 96 flights the price is 243 and + + align:start position:0% +the 96 flights the price is 243 and + + + align:start position:0% +the 96 flights the price is 243 and +that's the Monopoly + + align:start position:0% +that's the Monopoly + + + align:start position:0% +that's the Monopoly +outcome okay questions about + + align:start position:0% +outcome okay questions about + + + align:start position:0% +outcome okay questions about +that now imagine and this is a weird + + align:start position:0% +that now imagine and this is a weird + + + align:start position:0% +that now imagine and this is a weird +weird case but just imagine for a minute + + align:start position:0% +weird case but just imagine for a minute + + + align:start position:0% +weird case but just imagine for a minute +somehow through the indust through + + align:start position:0% +somehow through the indust through + + + align:start position:0% +somehow through the indust through +industrial Espionage America knew that + + align:start position:0% +industrial Espionage America knew that + + + align:start position:0% +industrial Espionage America knew that +United imagine how United is in the + + align:start position:0% +United imagine how United is in the + + + align:start position:0% +United imagine how United is in the +market it's no longer Monopoly and + + align:start position:0% +market it's no longer Monopoly and + + + align:start position:0% +market it's no longer Monopoly and +imagine americ knows United's going to + + align:start position:0% +imagine americ knows United's going to + + + align:start position:0% +imagine americ knows United's going to +fly 64 + + align:start position:0% +fly 64 + + + align:start position:0% +fly 64 +flights 64,000 is Thousands but doesn't + + align:start position:0% +flights 64,000 is Thousands but doesn't + + + align:start position:0% +flights 64,000 is Thousands but doesn't +matter Dr the unit I don't know somehow + + align:start position:0% +matter Dr the unit I don't know somehow + + + align:start position:0% +matter Dr the unit I don't know somehow +it knows they're going to do + + align:start position:0% +it knows they're going to do + + + align:start position:0% +it knows they're going to do +64 well what should American do given + + align:start position:0% +64 well what should American do given + + + align:start position:0% +64 well what should American do given +the knowledge that United's can do 64 + + align:start position:0% +the knowledge that United's can do 64 + + + align:start position:0% +the knowledge that United's can do 64 +flights well what it should do is it + + align:start position:0% +flights well what it should do is it + + + align:start position:0% +flights well what it should do is it +should compute its residual + + align:start position:0% +should compute its residual + + + align:start position:0% +should compute its residual +demand what's its residual demand it's + + align:start position:0% +demand what's its residual demand it's + + + align:start position:0% +demand what's its residual demand it's +the demand that's left over after United + + align:start position:0% +the demand that's left over after United + + + align:start position:0% +the demand that's left over after United +does the 64 flights so what's its + + align:start position:0% +does the 64 flights so what's its + + + align:start position:0% +does the 64 flights so what's its +residual demand well it's its residual + + align:start position:0% +residual demand well it's its residual + + + align:start position:0% +residual demand well it's its residual +demand is 339 + + align:start position:0% +demand is 339 + + + align:start position:0% +demand is 339 +minus what it's going to fly now it's + + align:start position:0% +minus what it's going to fly now it's + + + align:start position:0% +minus what it's going to fly now it's +little Q because there's two firms in + + align:start position:0% +little Q because there's two firms in + + + align:start position:0% +little Q because there's two firms in +the + + align:start position:0% +the + + + align:start position:0% +the +market minus the 64 flights that + + align:start position:0% +market minus the 64 flights that + + + align:start position:0% +market minus the 64 flights that +America's going to + + align:start position:0% +America's going to + + + align:start position:0% +America's going to +provide so its residual demand is + + align:start position:0% +provide so its residual demand is + + + align:start position:0% +provide so its residual demand is +275 minus Q + + align:start position:0% + + + + align:start position:0% + +Suba Q sub I'm sorry Q sub two yeah q75 + + align:start position:0% +Suba Q sub I'm sorry Q sub two yeah q75 + + + align:start position:0% +Suba Q sub I'm sorry Q sub two yeah q75 +minus Q Suba that's its residual demand + + align:start position:0% +minus Q Suba that's its residual demand + + + align:start position:0% +minus Q Suba that's its residual demand +well arm with that residual demand we + + align:start position:0% +well arm with that residual demand we + + + align:start position:0% +well arm with that residual demand we +can go back and redo the Monopoly + + align:start position:0% +can go back and redo the Monopoly + + + align:start position:0% +can go back and redo the Monopoly +example so look at figure + + align:start position:0% +example so look at figure + + + align:start position:0% +example so look at figure +132 americ is originally the outer Blue + + align:start position:0% +132 americ is originally the outer Blue + + + align:start position:0% +132 americ is originally the outer Blue +Line D the fact that United is flying 64 + + align:start position:0% +Line D the fact that United is flying 64 + + + align:start position:0% +Line D the fact that United is flying 64 +flights shifts it to the inner demand + + align:start position:0% +flights shifts it to the inner demand + + + align:start position:0% +flights shifts it to the inner demand +curve the residual demand curve D + + align:start position:0% +curve the residual demand curve D + + + align:start position:0% +curve the residual demand curve D +Prime but from there the magic is the + + align:start position:0% +Prime but from there the magic is the + + + align:start position:0% +Prime but from there the magic is the +same we compute marginal revenue which + + align:start position:0% +same we compute marginal revenue which + + + align:start position:0% +same we compute marginal revenue which +is Mr Prime we find where marginal + + align:start position:0% +is Mr Prime we find where marginal + + + align:start position:0% +is Mr Prime we find where marginal +revenue equals marginal + + align:start position:0% +revenue equals marginal + + + align:start position:0% +revenue equals marginal +cost okay so what what's marginal + + align:start position:0% +cost okay so what what's marginal + + + align:start position:0% +cost okay so what what's marginal +revenue marginal revenue here is going + + align:start position:0% +revenue marginal revenue here is going + + + align:start position:0% +revenue marginal revenue here is going +to be 275 minus 2 QA that's the marginal + + align:start position:0% +to be 275 minus 2 QA that's the marginal + + + align:start position:0% +to be 275 minus 2 QA that's the marginal +revenue I just multiplied that by q and + + align:start position:0% +revenue I just multiplied that by q and + + + align:start position:0% +revenue I just multiplied that by q and +then took the + + align:start position:0% +then took the + + + align:start position:0% +then took the +derivative marginal cost is + + align:start position:0% +derivative marginal cost is + + + align:start position:0% +derivative marginal cost is +147 so the new optimal Q subet is + + align:start position:0% +147 so the new optimal Q subet is + + + align:start position:0% +147 so the new optimal Q subet is +instead of 96 they're going to fly 64 + + align:start position:0% +instead of 96 they're going to fly 64 + + + align:start position:0% +instead of 96 they're going to fly 64 +flights so the new optimal Q sub a + + align:start position:0% +flights so the new optimal Q sub a + + + align:start position:0% +flights so the new optimal Q sub a +remember now Q sub is the old big Q + + align:start position:0% +remember now Q sub is the old big Q + + + align:start position:0% +remember now Q sub is the old big Q +because there's now two firms not one + + align:start position:0% +because there's now two firms not one + + + align:start position:0% +because there's now two firms not one +firm the new optimal Q sub is 64 flights + + align:start position:0% +firm the new optimal Q sub is 64 flights + + + align:start position:0% +firm the new optimal Q sub is 64 flights +and the optimal price is + + align:start position:0% +and the optimal price is + + + align:start position:0% +and the optimal price is +211 the price has come + + align:start position:0% +211 the price has come + + + align:start position:0% +211 the price has come +down + + align:start position:0% +down + + + align:start position:0% +down +why because now part of the Market's + + align:start position:0% +why because now part of the Market's + + + align:start position:0% +why because now part of the Market's +been taken so if they want to sell at + + align:start position:0% +been taken so if they want to sell at + + + align:start position:0% +been taken so if they want to sell at +this Market they've got to have a lower + + align:start position:0% +this Market they've got to have a lower + + + align:start position:0% +this Market they've got to have a lower +price so you get the new equilibrium + + align:start position:0% +price so you get the new equilibrium + + + align:start position:0% +price so you get the new equilibrium +which is where the maroon line the MRP + + align:start position:0% +which is where the maroon line the MRP + + + align:start position:0% +which is where the maroon line the MRP +Prime hits the red line the + + align:start position:0% +Prime hits the red line the + + + align:start position:0% +Prime hits the red line the +MC that's a 64 flights and a price you + + align:start position:0% +MC that's a 64 flights and a price you + + + align:start position:0% +MC that's a 64 flights and a price you +read off the man curve of + + align:start position:0% +read off the man curve of + + + align:start position:0% +read off the man curve of +21 questions about + + align:start position:0% +21 questions about + + + align:start position:0% +21 questions about +that + + align:start position:0% + + + + align:start position:0% + +yeah no it the question is doesn't + + align:start position:0% +yeah no it the question is doesn't + + + align:start position:0% +yeah no it the question is doesn't +matter what price they're setting + + align:start position:0% +matter what price they're setting + + + align:start position:0% +matter what price they're setting +actually it doesn't because all you + + align:start position:0% +actually it doesn't because all you + + + align:start position:0% +actually it doesn't because all you +because your curve here is just depend + + align:start position:0% +because your curve here is just depend + + + align:start position:0% +because your curve here is just depend +on how many flights they're going to + + align:start position:0% +on how many flights they're going to + + + align:start position:0% +on how many flights they're going to +sell now in reality it would but in + + align:start position:0% +sell now in reality it would but in + + + align:start position:0% +sell now in reality it would but in +practice it doesn't because we're + + align:start position:0% +practice it doesn't because we're + + + align:start position:0% +practice it doesn't because we're +assuming that this we're basically as + + align:start position:0% +assuming that this we're basically as + + + align:start position:0% +assuming that this we're basically as +long long as we know the other firm's + + align:start position:0% +long long as we know the other firm's + + + align:start position:0% +long long as we know the other firm's +conditions in particular if we know + + align:start position:0% +conditions in particular if we know + + + align:start position:0% +conditions in particular if we know +their marginal costs and things we're + + align:start position:0% +their marginal costs and things we're + + + align:start position:0% +their marginal costs and things we're +good here we are going to assume that + + align:start position:0% +good here we are going to assume that + + + align:start position:0% +good here we are going to assume that +the marginal cost of American equals the + + align:start position:0% +the marginal cost of American equals the + + + align:start position:0% +the marginal cost of American equals the +marginal cost of United and that makes + + align:start position:0% +marginal cost of United and that makes + + + align:start position:0% +marginal cost of United and that makes +the problem easier in + + align:start position:0% +the problem easier in + + + align:start position:0% +the problem easier in +reality you would you know in in reality + + align:start position:0% +reality you would you know in in reality + + + align:start position:0% +reality you would you know in in reality +it'd be more complicated but as long as + + align:start position:0% +it'd be more complicated but as long as + + + align:start position:0% +it'd be more complicated but as long as +we assume the marginal cost the same I + + align:start position:0% +we assume the marginal cost the same I + + + align:start position:0% +we assume the marginal cost the same I +don't need to know what they're going to + + align:start position:0% +don't need to know what they're going to + + + align:start position:0% +don't need to know what they're going to +set the price at I know what they're + + align:start position:0% +set the price at I know what they're + + + align:start position:0% +set the price at I know what they're +going to set the price at because + + align:start position:0% +going to set the price at because + + + align:start position:0% +going to set the price at because +they're like me it makes the problem + + align:start position:0% +they're like me it makes the problem + + + align:start position:0% +they're like me it makes the problem +symmetric the marginal costs are + + align:start position:0% +symmetric the marginal costs are + + + align:start position:0% +symmetric the marginal costs are +different it's not symmetric it's more + + align:start position:0% +different it's not symmetric it's more + + + align:start position:0% +different it's not symmetric it's more +complicated okay good question + + align:start position:0% +complicated okay good question + + + align:start position:0% +complicated okay good question +okay so basically in + + align:start position:0% + + + + align:start position:0% + +general in general of course American + + align:start position:0% +general in general of course American + + + align:start position:0% +general in general of course American +doesn't know how many flights United is + + align:start position:0% +doesn't know how many flights United is + + + align:start position:0% +doesn't know how many flights United is +going to fly so what American does is it + + align:start position:0% +going to fly so what American does is it + + + align:start position:0% +going to fly so what American does is it +asks for every quantity that United + + align:start position:0% +asks for every quantity that United + + + align:start position:0% +asks for every quantity that United +might fly how many do I want to fly it + + align:start position:0% +might fly how many do I want to fly it + + + align:start position:0% +might fly how many do I want to fly it +creates what we call its best response + + align:start position:0% +creates what we call its best response + + + align:start position:0% +creates what we call its best response +curve and that you can see as the Blue + + align:start position:0% +curve and that you can see as the Blue + + + align:start position:0% +curve and that you can see as the Blue +Line in figure + + align:start position:0% +Line in figure + + + align:start position:0% +Line in figure +133 figure 133 is the best response + + align:start position:0% +133 figure 133 is the best response + + + align:start position:0% +133 figure 133 is the best response +curve we know two points on this curve + + align:start position:0% +curve we know two points on this curve + + + align:start position:0% +curve we know two points on this curve +we know if you so what is this what let + + align:start position:0% +we know if you so what is this what let + + + align:start position:0% +we know if you so what is this what let +me back up what is this graph this graph + + align:start position:0% +me back up what is this graph this graph + + + align:start position:0% +me back up what is this graph this graph +has American this isn't price this isn't + + align:start position:0% +has American this isn't price this isn't + + + align:start position:0% +has American this isn't price this isn't +demand graph anymore this has the + + align:start position:0% +demand graph anymore this has the + + + align:start position:0% +demand graph anymore this has the +American quantity on the x axis and the + + align:start position:0% +American quantity on the x axis and the + + + align:start position:0% +American quantity on the x axis and the +United quantity on the y- axis so we're + + align:start position:0% +United quantity on the y- axis so we're + + + align:start position:0% +United quantity on the y- axis so we're +no longer doing a demand curve this is + + align:start position:0% +no longer doing a demand curve this is + + + align:start position:0% +no longer doing a demand curve this is +now a best response + + align:start position:0% +now a best response + + + align:start position:0% +now a best response +curve we know already I've already told + + align:start position:0% +curve we know already I've already told + + + align:start position:0% +curve we know already I've already told +you two points on this Blue Line I've + + align:start position:0% +you two points on this Blue Line I've + + + align:start position:0% +you two points on this Blue Line I've +told you that if United flies zero + + align:start position:0% +told you that if United flies zero + + + align:start position:0% +told you that if United flies zero +America flies 96 that's the x intercept + + align:start position:0% +America flies 96 that's the x intercept + + + align:start position:0% +America flies 96 that's the x intercept +of the Blue + + align:start position:0% +of the Blue + + + align:start position:0% +of the Blue +Line I've also told you that if United + + align:start position:0% +Line I've also told you that if United + + + align:start position:0% +Line I've also told you that if United +flies 64 American flyes 64 that's the + + align:start position:0% +flies 64 American flyes 64 that's the + + + align:start position:0% +flies 64 American flyes 64 that's the +6464 Point all this line is technically + + align:start position:0% +6464 Point all this line is technically + + + align:start position:0% +6464 Point all this line is technically +he going through this exercise over and + + align:start position:0% +he going through this exercise over and + + + align:start position:0% +he going through this exercise over and +over again for every possible qu + + align:start position:0% +over again for every possible qu + + + align:start position:0% +over again for every possible qu +quantity United could + + align:start position:0% +quantity United could + + + align:start position:0% +quantity United could +fly so this this exercise saying for + + align:start position:0% +fly so this this exercise saying for + + + align:start position:0% +fly so this this exercise saying for +every possible Quant United could fly + + align:start position:0% +every possible Quant United could fly + + + align:start position:0% +every possible Quant United could fly +what is my best response in other words + + align:start position:0% +what is my best response in other words + + + align:start position:0% +what is my best response in other words +if + + align:start position:0% +if + + + align:start position:0% +if +United is going to fly + + align:start position:0% +United is going to fly + + + align:start position:0% +United is going to fly +192 passengers in a quarter I should fly + + align:start position:0% + + + + align:start position:0% + +none now this problem is + + align:start position:0% +none now this problem is + + + align:start position:0% +none now this problem is +symmetric so United's best response + + align:start position:0% +symmetric so United's best response + + + align:start position:0% +symmetric so United's best response +curve is just the flip of American's + + align:start position:0% +curve is just the flip of American's + + + align:start position:0% +curve is just the flip of American's +best response curve they have the same + + align:start position:0% +best response curve they have the same + + + align:start position:0% +best response curve they have the same +cost structure marginal cost is the same + + align:start position:0% +cost structure marginal cost is the same + + + align:start position:0% +cost structure marginal cost is the same +and they face the same market conditions + + align:start position:0% +and they face the same market conditions + + + align:start position:0% +and they face the same market conditions +they're in the same demand market so + + align:start position:0% +they're in the same demand market so + + + align:start position:0% +they're in the same demand market so +it's a symmetric problem + + align:start position:0% +it's a symmetric problem + + + align:start position:0% +it's a symmetric problem +so United's best response curve is the + + align:start position:0% +so United's best response curve is the + + + align:start position:0% +so United's best response curve is the +flip if American flies + + align:start position:0% +flip if American flies + + + align:start position:0% +flip if American flies +nothing United should fly 96 which is + + align:start position:0% +nothing United should fly 96 which is + + + align:start position:0% +nothing United should fly 96 which is +the Y intercept of the red + + align:start position:0% +the Y intercept of the red + + + align:start position:0% +the Y intercept of the red +line if American flies 64 United should + + align:start position:0% +line if American flies 64 United should + + + align:start position:0% +line if American flies 64 United should +fly 64 and if America flies 192 United + + align:start position:0% +fly 64 and if America flies 192 United + + + align:start position:0% +fly 64 and if America flies 192 United +stat should fly + + align:start position:0% + + + + align:start position:0% + +nothing these are the graphical + + align:start position:0% +nothing these are the graphical + + + align:start position:0% +nothing these are the graphical +illustration of each firm's dominant + + align:start position:0% +illustration of each firm's dominant + + + align:start position:0% +illustration of each firm's dominant +strategy + + align:start position:0% +strategy + + + align:start position:0% +strategy +their cor no strategy remember is asking + + align:start position:0% +their cor no strategy remember is asking + + + align:start position:0% +their cor no strategy remember is asking +what's the best thing I want to do given + + align:start position:0% +what's the best thing I want to do given + + + align:start position:0% +what's the best thing I want to do given +what the other person's doing well I + + align:start position:0% +what the other person's doing well I + + + align:start position:0% +what the other person's doing well I +told you what the person's doing so the + + align:start position:0% +told you what the person's doing so the + + + align:start position:0% +told you what the person's doing so the +dominant strategy for American is to + + align:start position:0% +dominant strategy for American is to + + + align:start position:0% +dominant strategy for American is to +plug in every possible thing United + + align:start position:0% +plug in every possible thing United + + + align:start position:0% +plug in every possible thing United +could + + align:start position:0% +could + + + align:start position:0% +could +do and then ask what's the best thing + + align:start position:0% +do and then ask what's the best thing + + + align:start position:0% +do and then ask what's the best thing +for me to + + align:start position:0% +for me to + + + align:start position:0% +for me to +do United does the same thing they plug + + align:start position:0% +do United does the same thing they plug + + + align:start position:0% +do United does the same thing they plug +in every possible thing American could + + align:start position:0% +in every possible thing American could + + + align:start position:0% +in every possible thing American could +do and ask what's the best thing for me + + align:start position:0% +do and ask what's the best thing for me + + + align:start position:0% +do and ask what's the best thing for me +to do if those two curves intersect + + align:start position:0% +to do if those two curves intersect + + + align:start position:0% +to do if those two curves intersect +we have + + align:start position:0% +we have + + + align:start position:0% +we have +equilibrium the Koo equilibrium here is + + align:start position:0% +equilibrium the Koo equilibrium here is + + + align:start position:0% +equilibrium the Koo equilibrium here is +at the point + + align:start position:0% +at the point + + + align:start position:0% +at the point +6464 why because that is the one + + align:start position:0% +6464 why because that is the one + + + align:start position:0% +6464 why because that is the one +point where given what United's doing + + align:start position:0% +point where given what United's doing + + + align:start position:0% +point where given what United's doing +American doesn't want to change its + + align:start position:0% +American doesn't want to change its + + + align:start position:0% +American doesn't want to change its +strategy and given what Americans doing + + align:start position:0% +strategy and given what Americans doing + + + align:start position:0% +strategy and given what Americans doing +United doesn't want to change his + + align:start position:0% +United doesn't want to change his + + + align:start position:0% +United doesn't want to change his +strategy + + align:start position:0% +strategy + + + align:start position:0% +strategy +yeah what's that what + + align:start position:0% +yeah what's that what + + + align:start position:0% +yeah what's that what +there's uh once again that's why you + + align:start position:0% +there's uh once again that's why you + + + align:start position:0% +there's uh once again that's why you +take 1412 there's all sorts of fun + + align:start position:0% +take 1412 there's all sorts of fun + + + align:start position:0% +take 1412 there's all sorts of fun +things what if there's two intersections + + align:start position:0% +things what if there's two intersections + + + align:start position:0% +things what if there's two intersections +what if there's no inter intersection + + align:start position:0% +what if there's no inter intersection + + + align:start position:0% +what if there's no inter intersection +all sorts of fun examples take 1412 + + align:start position:0% +all sorts of fun examples take 1412 + + + align:start position:0% +all sorts of fun examples take 1412 +we'll go through all of them we only + + align:start position:0% +we'll go through all of them we only + + + align:start position:0% +we'll go through all of them we only +have a couple lectures for Game Theory + + align:start position:0% +have a couple lectures for Game Theory + + + align:start position:0% +have a couple lectures for Game Theory +here so I can't go through all those but + + align:start position:0% +here so I can't go through all those but + + + align:start position:0% +here so I can't go through all those but +it gets complicated let me just say that + + align:start position:0% +it gets complicated let me just say that + + + align:start position:0% +it gets complicated let me just say that +you basically it's called a multiple + + align:start position:0% +you basically it's called a multiple + + + align:start position:0% +you basically it's called a multiple +equilibria and it basically then where + + align:start position:0% +equilibria and it basically then where + + + align:start position:0% +equilibria and it basically then where +you start determines where you finish in + + align:start position:0% +you start determines where you finish in + + + align:start position:0% +you start determines where you finish in +this model doesn't matter where you + + align:start position:0% +this model doesn't matter where you + + + align:start position:0% +this model doesn't matter where you +start there's one equilibria that's + + align:start position:0% +start there's one equilibria that's + + + align:start position:0% +start there's one equilibria that's +robust okay but um uh in a multiple + + align:start position:0% +robust okay but um uh in a multiple + + + align:start position:0% +robust okay but um uh in a multiple +equilibria uh where you start could + + align:start position:0% +equilibria uh where you start could + + + align:start position:0% +equilibria uh where you start could +could determine where you finish so in + + align:start position:0% +could determine where you finish so in + + + align:start position:0% +could determine where you finish so in +my example with Andrew okay in a single + + align:start position:0% +my example with Andrew okay in a single + + + align:start position:0% +my example with Andrew okay in a single +equilibrium model it doesn't matter sort + + align:start position:0% +equilibrium model it doesn't matter sort + + + align:start position:0% +equilibrium model it doesn't matter sort +of who started the fight okay but the + + align:start position:0% +of who started the fight okay but the + + + align:start position:0% +of who started the fight okay but the +multile model you might have very + + align:start position:0% +multile model you might have very + + + align:start position:0% +multile model you might have very +different outcomes based on who started + + align:start position:0% +different outcomes based on who started + + + align:start position:0% +different outcomes based on who started +the + + align:start position:0% +the + + + align:start position:0% +the +fight okay so basically that + + align:start position:0% +fight okay so basically that + + + align:start position:0% +fight okay so basically that +is the + + align:start position:0% +is the + + + align:start position:0% +is the +intersection okay and you can't be + + align:start position:0% +intersection okay and you can't be + + + align:start position:0% +intersection okay and you can't be +here's the key + + align:start position:0% +here's the key + + + align:start position:0% +here's the key +Point American can't be can't say look + + align:start position:0% +Point American can't be can't say look + + + align:start position:0% +Point American can't be can't say look +gee but my profit I I I I liked it much + + align:start position:0% +gee but my profit I I I I liked it much + + + align:start position:0% +gee but my profit I I I I liked it much +better when I was doing this like I had + + align:start position:0% +better when I was doing this like I had + + + align:start position:0% +better when I was doing this like I had +96 lights at a higher price + + align:start position:0% +96 lights at a higher price + + + align:start position:0% +96 lights at a higher price +okay so I like that much better why + + align:start position:0% +okay so I like that much better why + + + align:start position:0% +okay so I like that much better why +can't I just do that well they can't + + align:start position:0% +can't I just do that well they can't + + + align:start position:0% +can't I just do that well they can't +because American because America won't + + align:start position:0% +because American because America won't + + + align:start position:0% +because American because America won't +let them or americ can't because United + + align:start position:0% +let them or americ can't because United + + + align:start position:0% +let them or americ can't because United +won't let them they have to account for + + align:start position:0% +won't let them they have to account for + + + align:start position:0% +won't let them they have to account for +the other firm's response and that's + + align:start position:0% +the other firm's response and that's + + + align:start position:0% +the other firm's response and that's +what's cool about oligopoly that's why + + align:start position:0% +what's cool about oligopoly that's why + + + align:start position:0% +what's cool about oligopoly that's why +the game theory because you have to + + align:start position:0% +the game theory because you have to + + + align:start position:0% +the game theory because you have to +account for the other firm's response + + align:start position:0% +account for the other firm's response + + + align:start position:0% +account for the other firm's response +okay that's the graphics let's go + + align:start position:0% +okay that's the graphics let's go + + + align:start position:0% +okay that's the graphics let's go +through the math okay let's do the Coro + + align:start position:0% +through the math okay let's do the Coro + + + align:start position:0% +through the math okay let's do the Coro +math to show you how this works + + align:start position:0% +math to show you how this works + + + align:start position:0% +math to show you how this works +mathematically + + align:start position:0% +mathematically + + + align:start position:0% +mathematically +yeah + + align:start position:0% + + + + align:start position:0% + +begin well that that's a great great + + align:start position:0% +begin well that that's a great great + + + align:start position:0% +begin well that that's a great great +question you're asking about sort of + + align:start position:0% +question you're asking about sort of + + + align:start position:0% +question you're asking about sort of +market dynamics we're calling this sort + + align:start position:0% +market dynamics we're calling this sort + + + align:start position:0% +market dynamics we're calling this sort +of a steady state equilibrium think of + + align:start position:0% +of a steady state equilibrium think of + + + align:start position:0% +of a steady state equilibrium think of +this as short run versus long run in the + + align:start position:0% +this as short run versus long run in the + + + align:start position:0% +this as short run versus long run in the +short run probably not right in the + + align:start position:0% +short run probably not right in the + + + align:start position:0% +short run probably not right in the +short run you'll buy a certain am planes + + align:start position:0% +short run you'll buy a certain am planes + + + align:start position:0% +short run you'll buy a certain am planes +they'll buy certain planes you'll you'll + + align:start position:0% +they'll buy certain planes you'll you'll + + + align:start position:0% +they'll buy certain planes you'll you'll +fck around for a while and then you'll + + align:start position:0% +fck around for a while and then you'll + + + align:start position:0% +fck around for a while and then you'll +say ah this is the point at which in the + + align:start position:0% +say ah this is the point at which in the + + + align:start position:0% +say ah this is the point at which in the +long run things are stable so let's kind + + align:start position:0% +long run things are stable so let's kind + + + align:start position:0% +long run things are stable so let's kind +of think of this more sort of a long run + + align:start position:0% +of think of this more sort of a long run + + + align:start position:0% +of think of this more sort of a long run +versus a short run + + align:start position:0% +versus a short run + + + align:start position:0% +versus a short run +okay other questions good question other + + align:start position:0% +okay other questions good question other + + + align:start position:0% +okay other questions good question other +questions okay so basically let's look + + align:start position:0% +questions okay so basically let's look + + + align:start position:0% +questions okay so basically let's look +at the math of the chono + + align:start position:0% +at the math of the chono + + + align:start position:0% +at the math of the chono +equilibrium okay + + align:start position:0% +equilibrium okay + + + align:start position:0% +equilibrium okay +so the first thing we do we don't do + + align:start position:0% +so the first thing we do we don't do + + + align:start position:0% +so the first thing we do we don't do +this whatever the hell that + + align:start position:0% +this whatever the hell that + + + align:start position:0% +this whatever the hell that +is the first thing we do is we solve for + + align:start position:0% +is the first thing we do is we solve for + + + align:start position:0% +is the first thing we do is we solve for +each firm's residual demand curve and + + align:start position:0% +each firm's residual demand curve and + + + align:start position:0% +each firm's residual demand curve and +it's a symmetric problem I could solve + + align:start position:0% +it's a symmetric problem I could solve + + + align:start position:0% +it's a symmetric problem I could solve +this for one + + align:start position:0% +this for one + + + align:start position:0% +this for one +firm and I know what I'll get for the + + align:start position:0% +firm and I know what I'll get for the + + + align:start position:0% +firm and I know what I'll get for the +other firm I have to solve for one firm + + align:start position:0% +other firm I have to solve for one firm + + + align:start position:0% +other firm I have to solve for one firm +so what is American's residual demand + + align:start position:0% +so what is American's residual demand + + + align:start position:0% +so what is American's residual demand +curve well it's + + align:start position:0% +curve well it's + + + align:start position:0% +curve well it's +339 minus QA minus qu I plugged in 64 + + align:start position:0% +339 minus QA minus qu I plugged in 64 + + + align:start position:0% +339 minus QA minus qu I plugged in 64 +before because I had some industrial + + align:start position:0% +before because I had some industrial + + + align:start position:0% +before because I had some industrial +Espionage it was told me 64 but in + + align:start position:0% +Espionage it was told me 64 but in + + + align:start position:0% +Espionage it was told me 64 but in +general I don't know what United's going + + align:start position:0% +general I don't know what United's going + + + align:start position:0% +general I don't know what United's going +to do so I just put in this amount + + align:start position:0% +to do so I just put in this amount + + + align:start position:0% +to do so I just put in this amount +qu + + align:start position:0% +qu + + + align:start position:0% +qu +okay now what is revenue then revenue is + + align:start position:0% +okay now what is revenue then revenue is + + + align:start position:0% +okay now what is revenue then revenue is +339 QA this is American's calculation of + + align:start position:0% +339 QA this is American's calculation of + + + align:start position:0% +339 QA this is American's calculation of +its + + align:start position:0% +its + + + align:start position:0% +its +Revenue minus QA 2 minus qu + + align:start position:0% + + + + align:start position:0% + +QA what is marginal re Revenue well I + + align:start position:0% +QA what is marginal re Revenue well I + + + align:start position:0% +QA what is marginal re Revenue well I +differentiate with respect to QA this is + + align:start position:0% +differentiate with respect to QA this is + + + align:start position:0% +differentiate with respect to QA this is +American's decision so what it's his + + align:start position:0% +American's decision so what it's his + + + align:start position:0% +American's decision so what it's his +marginal revenue it's + + align:start position:0% +marginal revenue it's + + + align:start position:0% +marginal revenue it's +339 minus 2 QA minus + + align:start position:0% +339 minus 2 QA minus + + + align:start position:0% +339 minus 2 QA minus +qu so now I've got a a new term in my + + align:start position:0% +qu so now I've got a a new term in my + + + align:start position:0% +qu so now I've got a a new term in my +marginal revenue equation I didn't have + + align:start position:0% +marginal revenue equation I didn't have + + + align:start position:0% +marginal revenue equation I didn't have +before in other examples the other + + align:start position:0% +before in other examples the other + + + align:start position:0% +before in other examples the other +firm's quantity enters into my marginal + + align:start position:0% + + + + align:start position:0% + +revenue so we set this equal to marginal + + align:start position:0% +revenue so we set this equal to marginal + + + align:start position:0% +revenue so we set this equal to marginal +cost which is 147 + + align:start position:0% +cost which is 147 + + + align:start position:0% +cost which is 147 +once again symmetrically I said marginal + + align:start position:0% +once again symmetrically I said marginal + + + align:start position:0% +once again symmetrically I said marginal +cost 147 for + + align:start position:0% +cost 147 for + + + align:start position:0% +cost 147 for +everybody set that equal the marginal + + align:start position:0% +everybody set that equal the marginal + + + align:start position:0% +everybody set that equal the marginal +cost + + align:start position:0% +cost + + + align:start position:0% +cost +okay by the way let me go back one + + align:start position:0% +okay by the way let me go back one + + + align:start position:0% +okay by the way let me go back one +second go back to the figure go back to + + align:start position:0% +second go back to the figure go back to + + + align:start position:0% +second go back to the figure go back to +figure 131 and 132 one thing that's + + align:start position:0% +figure 131 and 132 one thing that's + + + align:start position:0% +figure 131 and 132 one thing that's +implicit I didn't say is an example + + align:start position:0% +implicit I didn't say is an example + + + align:start position:0% +implicit I didn't say is an example +average cost also equals marginal cost + + align:start position:0% +average cost also equals marginal cost + + + align:start position:0% +average cost also equals marginal cost +for the relevant range right because + + align:start position:0% +for the relevant range right because + + + align:start position:0% +for the relevant range right because +marginal cost is flat so the relevant + + align:start position:0% +marginal cost is flat so the relevant + + + align:start position:0% +marginal cost is flat so the relevant +range we're examining here average cost + + align:start position:0% +range we're examining here average cost + + + align:start position:0% +range we're examining here average cost +equals marginal cost it' be marginal + + align:start position:0% +equals marginal cost it' be marginal + + + align:start position:0% +equals marginal cost it' be marginal +cost could be the same and average cost + + align:start position:0% +cost could be the same and average cost + + + align:start position:0% +cost could be the same and average cost +could be structure be different and then + + align:start position:0% +could be structure be different and then + + + align:start position:0% +could be structure be different and then +it get complicated again so really what + + align:start position:0% +it get complicated again so really what + + + align:start position:0% +it get complicated again so really what +assuming is basically cost structure is + + align:start position:0% +assuming is basically cost structure is + + + align:start position:0% +assuming is basically cost structure is +the same across the companies at least a + + align:start position:0% +the same across the companies at least a + + + align:start position:0% +the same across the companies at least a +relevant range okay so you set that + + align:start position:0% +relevant range okay so you set that + + + align:start position:0% +relevant range okay so you set that +equal to marginal cost you solve and you + + align:start position:0% +equal to marginal cost you solve and you + + + align:start position:0% +equal to marginal cost you solve and you +get you solve that and you get the + + align:start position:0% +get you solve that and you get the + + + align:start position:0% +get you solve that and you get the +QA equal 96 minus 12 + + align:start position:0% + + + + align:start position:0% + +qu okay so now we don't get a + + align:start position:0% +qu okay so now we don't get a + + + align:start position:0% +qu okay so now we don't get a +deterministic answer we get that what I + + align:start position:0% +deterministic answer we get that what I + + + align:start position:0% +deterministic answer we get that what I +should fly is 96 -2 qu guess what that's + + align:start position:0% +should fly is 96 -2 qu guess what that's + + + align:start position:0% +should fly is 96 -2 qu guess what that's +the Blue Line in figure + + align:start position:0% +the Blue Line in figure + + + align:start position:0% +the Blue Line in figure +133 check it out it's 96 minus 1 12 + + align:start position:0% +133 check it out it's 96 minus 1 12 + + + align:start position:0% +133 check it out it's 96 minus 1 12 +qu well it turns out the problem + + align:start position:0% +qu well it turns out the problem + + + align:start position:0% +qu well it turns out the problem +symmetric so United has the same best + + align:start position:0% +symmetric so United has the same best + + + align:start position:0% +symmetric so United has the same best +response + + align:start position:0% +response + + + align:start position:0% +response +function I could do the same math for + + align:start position:0% +function I could do the same math for + + + align:start position:0% +function I could do the same math for +United and i' get the qu equal 96 - 12 + + align:start position:0% +United and i' get the qu equal 96 - 12 + + + align:start position:0% +United and i' get the qu equal 96 - 12 +QA + + align:start position:0% + + + + align:start position:0% + +qu = 96 - 12 QA because it's symmetric + + align:start position:0% +qu = 96 - 12 QA because it's symmetric + + + align:start position:0% +qu = 96 - 12 QA because it's symmetric +so guess what I have two equations and + + align:start position:0% +so guess what I have two equations and + + + align:start position:0% +so guess what I have two equations and +two unknowns I have two best response + + align:start position:0% +two unknowns I have two best response + + + align:start position:0% +two unknowns I have two best response +functions intersecting or maybe not two + + align:start position:0% +functions intersecting or maybe not two + + + align:start position:0% +functions intersecting or maybe not two +equations two unknowns so I can solve + + align:start position:0% +equations two unknowns so I can solve + + + align:start position:0% +equations two unknowns so I can solve +this these two equations in two + + align:start position:0% +this these two equations in two + + + align:start position:0% +this these two equations in two +unknowns and I can get that QA equals 64 + + align:start position:0% +unknowns and I can get that QA equals 64 + + + align:start position:0% +unknowns and I can get that QA equals 64 +and by + + align:start position:0% +and by + + + align:start position:0% +and by +symmetry qu equal 64 + + align:start position:0% + + + + align:start position:0% + +so that is how I just mathematically + + align:start position:0% +so that is how I just mathematically + + + align:start position:0% +so that is how I just mathematically +solved for that intersection now once + + align:start position:0% +solved for that intersection now once + + + align:start position:0% +solved for that intersection now once +again you might solve this if find no + + align:start position:0% +again you might solve this if find no + + + align:start position:0% +again you might solve this if find no +intersection two equations two unknowns + + align:start position:0% +intersection two equations two unknowns + + + align:start position:0% +intersection two equations two unknowns +you might get no rational answer and + + align:start position:0% +you might get no rational answer and + + + align:start position:0% +you might get no rational answer and +that would mean the market would just + + align:start position:0% +that would mean the market would just + + + align:start position:0% +that would mean the market would just +collapse okay or you get multiple + + align:start position:0% +collapse okay or you get multiple + + + align:start position:0% +collapse okay or you get multiple +answers and that's more + + align:start position:0% +answers and that's more + + + align:start position:0% +answers and that's more +complicated but generally you get one + + align:start position:0% +complicated but generally you get one + + + align:start position:0% +complicated but generally you get one +answer in this class at + + align:start position:0% +answer in this class at + + + align:start position:0% +answer in this class at +least okay and that with equilibrium + + align:start position:0% +least okay and that with equilibrium + + + align:start position:0% +least okay and that with equilibrium +yeah + + align:start position:0% + + + + align:start position:0% + +great question does anyone know great + + align:start position:0% +great question does anyone know great + + + align:start position:0% +great question does anyone know great +question because what's big Q here big Q + + align:start position:0% +question because what's big Q here big Q + + + align:start position:0% +question because what's big Q here big Q +now in the market is 128 and what's the + + align:start position:0% +now in the market is 128 and what's the + + + align:start position:0% +now in the market is 128 and what's the +price well we know the demand curve the + + align:start position:0% +price well we know the demand curve the + + + align:start position:0% +price well we know the demand curve the +demand curve hasn't changed demand curve + + align:start position:0% +demand curve hasn't changed demand curve + + + align:start position:0% +demand curve hasn't changed demand curve +is 339 minus Q it's one market demand + + align:start position:0% +is 339 minus Q it's one market demand + + + align:start position:0% +is 339 minus Q it's one market demand +curve so the new price is uh 339 minus + + align:start position:0% +curve so the new price is uh 339 minus + + + align:start position:0% +curve so the new price is uh 339 minus +128 so 211 + + align:start position:0% + + + + align:start position:0% + +okay but Q is 128 whereas when just + + align:start position:0% +okay but Q is 128 whereas when just + + + align:start position:0% +okay but Q is 128 whereas when just +America is 96 great question + + align:start position:0% + + + + align:start position:0% + +why + + align:start position:0% +why + + + align:start position:0% +why +yeah like firm that controls everything + + align:start position:0% +yeah like firm that controls everything + + + align:start position:0% +yeah like firm that controls everything +PR PR well they're they're in between + + align:start position:0% +PR PR well they're they're in between + + + align:start position:0% +PR PR well they're they're in between +price takers and price makers but + + align:start position:0% +price takers and price makers but + + + align:start position:0% +price takers and price makers but +effectively the way we model it they're + + align:start position:0% +effectively the way we model it they're + + + align:start position:0% +effectively the way we model it they're +price takers but the intuition is when + + align:start position:0% +price takers but the intuition is when + + + align:start position:0% +price takers but the intuition is when +I'm + + align:start position:0% +I'm + + + align:start position:0% +I'm +monopolist I am maximizing the profits + + align:start position:0% +monopolist I am maximizing the profits + + + align:start position:0% +monopolist I am maximizing the profits +for me + + align:start position:0% +for me + + + align:start position:0% +for me +finding out what Max has my profits + + align:start position:0% +finding out what Max has my profits + + + align:start position:0% +finding out what Max has my profits +which is a high price and a low quantity + + align:start position:0% +which is a high price and a low quantity + + + align:start position:0% +which is a high price and a low quantity +once I'm sharing the market think about + + align:start position:0% +once I'm sharing the market think about + + + align:start position:0% +once I'm sharing the market think about +the Monopoly poison effect this is a + + align:start position:0% +the Monopoly poison effect this is a + + + align:start position:0% +the Monopoly poison effect this is a +great hint for what we'll cover next + + align:start position:0% +great hint for what we'll cover next + + + align:start position:0% +great hint for what we'll cover next +time think about what happens the + + align:start position:0% +time think about what happens the + + + align:start position:0% +time think about what happens the +Monopoly poisoning effect if I sell more + + align:start position:0% +Monopoly poisoning effect if I sell more + + + align:start position:0% +Monopoly poisoning effect if I sell more +in the market who bears that poisoning + + align:start position:0% +in the market who bears that poisoning + + + align:start position:0% +in the market who bears that poisoning +effect both of us because once Q goes up + + align:start position:0% +effect both of us because once Q goes up + + + align:start position:0% +effect both of us because once Q goes up +once big Q goes up the price Falls we + + align:start position:0% +once big Q goes up the price Falls we + + + align:start position:0% +once big Q goes up the price Falls we +both suffer from lower fall so it some + + align:start position:0% +both suffer from lower fall so it some + + + align:start position:0% +both suffer from lower fall so it some +says I'm offloading half of the + + align:start position:0% +says I'm offloading half of the + + + align:start position:0% +says I'm offloading half of the +poisoning effect when I'm monopolist + + align:start position:0% +poisoning effect when I'm monopolist + + + align:start position:0% +poisoning effect when I'm monopolist +every additional un price I want to + + align:start position:0% +every additional un price I want to + + + align:start position:0% +every additional un price I want to +sell low is my profit when I'm in this + + align:start position:0% +sell low is my profit when I'm in this + + + align:start position:0% +sell low is my profit when I'm in this +larger group there's sort of a sharing + + align:start position:0% +larger group there's sort of a sharing + + + align:start position:0% +larger group there's sort of a sharing +of the poisoning effect so each firm so + + align:start position:0% +of the poisoning effect so each firm so + + + align:start position:0% +of the poisoning effect so each firm so +you end up selling more what we'll show + + align:start position:0% +you end up selling more what we'll show + + + align:start position:0% +you end up selling more what we'll show +next time is why ex exactly this + + align:start position:0% +next time is why ex exactly this + + + align:start position:0% +next time is why ex exactly this +intuition will be clearer next time + + align:start position:0% +intuition will be clearer next time + + + align:start position:0% +intuition will be clearer next time +leads to cartels not to be + + align:start position:0% +leads to cartels not to be + + + align:start position:0% +leads to cartels not to be +functional and it's why we'll show next + + align:start position:0% +functional and it's why we'll show next + + + align:start position:0% +functional and it's why we'll show next +time the limit of oligopoly is perfect + + align:start position:0% +time the limit of oligopoly is perfect + + + align:start position:0% +time the limit of oligopoly is perfect +competition okay but the bottom line is + + align:start position:0% +competition okay but the bottom line is + + + align:start position:0% +competition okay but the bottom line is +when you get when you have a Coro + + align:start position:0% +when you get when you have a Coro + + + align:start position:0% +when you get when you have a Coro +equilibrium you end up with an answer + + align:start position:0% +equilibrium you end up with an answer + + + align:start position:0% +equilibrium you end up with an answer +that is not perfect competition remember + + align:start position:0% +that is not perfect competition remember + + + align:start position:0% +that is not perfect competition remember +what would perfect competition say the + + align:start position:0% +what would perfect competition say the + + + align:start position:0% +what would perfect competition say the +quantity would be can anyone tell me + + align:start position:0% +quantity would be can anyone tell me + + + align:start position:0% +quantity would be can anyone tell me +what would the quantity be under perfect + + align:start position:0% + + + + align:start position:0% + +competition what would big Q be in this + + align:start position:0% +competition what would big Q be in this + + + align:start position:0% +competition what would big Q be in this +market with perfect + + align:start position:0% + + + + align:start position:0% + +competition it involves one one equation + + align:start position:0% +competition it involves one one equation + + + align:start position:0% +competition it involves one one equation +solving one equation + + align:start position:0% +solving one equation + + + align:start position:0% +solving one equation +yeah it'd be n and how'd you get that + + align:start position:0% + + + + align:start position:0% + +uh no perfect competition perfect that's + + align:start position:0% +uh no perfect competition perfect that's + + + align:start position:0% +uh no perfect competition perfect that's +exactly this question here if there's + + align:start position:0% +exactly this question here if there's + + + align:start position:0% +exactly this question here if there's +perfect competition what would yeah in + + align:start position:0% +perfect competition what would yeah in + + + align:start position:0% +perfect competition what would yeah in +the + + align:start position:0% +the + + + align:start position:0% +the +back what 64 how'd you get + + align:start position:0% + + + + align:start position:0% + +that well well okay that's one way to do + + align:start position:0% +that well well okay that's one way to do + + + align:start position:0% +that well well okay that's one way to do +it what's another way to do it well if + + align:start position:0% +it what's another way to do it well if + + + align:start position:0% +it what's another way to do it well if +it's perfect competition what do we know + + align:start position:0% +it's perfect competition what do we know + + + align:start position:0% +it's perfect competition what do we know +come on guys got ready for tomorrow + + align:start position:0% +come on guys got ready for tomorrow + + + align:start position:0% +come on guys got ready for tomorrow +night what's the profit maximizing + + align:start position:0% +night what's the profit maximizing + + + align:start position:0% +night what's the profit maximizing +condition perfect competition price + + align:start position:0% +condition perfect competition price + + + align:start position:0% +condition perfect competition price +equals what marginal cost so we just say + + align:start position:0% +equals what marginal cost so we just say + + + align:start position:0% +equals what marginal cost so we just say +well look you want to competition price + + align:start position:0% +well look you want to competition price + + + align:start position:0% +well look you want to competition price +equals marginal cost so what's the price + + align:start position:0% +equals marginal cost so what's the price + + + align:start position:0% +equals marginal cost so what's the price +what's marginal cost 147 so you know + + align:start position:0% +what's marginal cost 147 so you know + + + align:start position:0% +what's marginal cost 147 so you know +price equals 147 and then you simply + + align:start position:0% +price equals 147 and then you simply + + + align:start position:0% +price equals 147 and then you simply +know that demand that the quantity is + + align:start position:0% +know that demand that the quantity is + + + align:start position:0% +know that demand that the quantity is +339 minus + + align:start position:0% +339 minus + + + align:start position:0% +339 minus +147 the quanti is going to be 3 339 + + align:start position:0% +147 the quanti is going to be 3 339 + + + align:start position:0% +147 the quanti is going to be 3 339 +minus 147 which is going to be uh 192 + + align:start position:0% +minus 147 which is going to be uh 192 + + + align:start position:0% +minus 147 which is going to be uh 192 +right is that right uh + + align:start position:0% +right is that right uh + + + align:start position:0% +right is that right uh +no uh no I got this wrong 33 9 - 147 + + align:start position:0% +no uh no I got this wrong 33 9 - 147 + + + align:start position:0% +no uh no I got this wrong 33 9 - 147 +that's a hard math + + align:start position:0% +that's a hard math + + + align:start position:0% +that's a hard math +340 340 so + + align:start position:0% +340 340 so + + + align:start position:0% +340 340 so +200 200 yeah 192 right yeah 192 I don't + + align:start position:0% +200 200 yeah 192 right yeah 192 I don't + + + align:start position:0% +200 200 yeah 192 right yeah 192 I don't +have I'm really insecure about my math + + align:start position:0% +have I'm really insecure about my math + + + align:start position:0% +have I'm really insecure about my math +skills okay so 192 + + align:start position:0% +skills okay so 192 + + + align:start position:0% +skills okay so 192 +192 is much bigger than Monopoly which + + align:start position:0% +192 is much bigger than Monopoly which + + + align:start position:0% +192 is much bigger than Monopoly which +was 96 it's also bigger than what we got + + align:start position:0% +was 96 it's also bigger than what we got + + + align:start position:0% +was 96 it's also bigger than what we got +in the oligopoly + + align:start position:0% +in the oligopoly + + + align:start position:0% +in the oligopoly +case so what we see is oligopoly leads + + align:start position:0% +case so what we see is oligopoly leads + + + align:start position:0% +case so what we see is oligopoly leads +us to be in between Monopoly and perfect + + align:start position:0% +us to be in between Monopoly and perfect + + + align:start position:0% +us to be in between Monopoly and perfect +competition and we'll come back next + + align:start position:0% +competition and we'll come back next + + + align:start position:0% +competition and we'll come back next +time review that and tell you why that + + align:start position:0% +time review that and tell you why that + + + align:start position:0% +time review that and tell you why that +is show you why that is all right okay + + align:start position:0% +is show you why that is all right okay + + + align:start position:0% +is show you why that is all right okay +let's stop there good luck tomorrow + + align:start position:0% +let's stop there good luck tomorrow + + + align:start position:0% +let's stop there good luck tomorrow +night I'll see yall bright and early on + + align:start position:0% +night I'll see yall bright and early on + + + align:start position:0% +night I'll see yall bright and early on +Wednesday and we'll continue this + + align:start position:0% +Wednesday and we'll continue this + + + align:start position:0% +Wednesday and we'll continue this +discussion \ No newline at end of file diff --git a/aAk1hYy7VuY.txt b/aAk1hYy7VuY.txt new file mode 100644 index 0000000000000000000000000000000000000000..bef534a10c52f6740fc372d1d9a6a837f87fcff0 --- /dev/null +++ b/aAk1hYy7VuY.txt @@ -0,0 +1,8307 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so we were talking about + + align:start position:0% +ocw.mit.edu so we were talking about + + + align:start position:0% +ocw.mit.edu so we were talking about +factors affecting the rates of + + align:start position:0% +factors affecting the rates of + + + align:start position:0% +factors affecting the rates of +reaction and uh so we have gone through + + align:start position:0% +reaction and uh so we have gone through + + + align:start position:0% +reaction and uh so we have gone through +a number of these + + align:start position:0% + + + + align:start position:0% + +so we talked last class about the effect + + align:start position:0% +so we talked last class about the effect + + + align:start position:0% +so we talked last class about the effect +of temperature we talked about mechanism + + align:start position:0% +of temperature we talked about mechanism + + + align:start position:0% +of temperature we talked about mechanism +last Wednesday we talked about nature of + + align:start position:0% +last Wednesday we talked about nature of + + + align:start position:0% +last Wednesday we talked about nature of +material and + + align:start position:0% +material and + + + align:start position:0% +material and +concentrations uh in the lectures + + align:start position:0% +concentrations uh in the lectures + + + align:start position:0% +concentrations uh in the lectures +preceding that and now we're up to the + + align:start position:0% +preceding that and now we're up to the + + + align:start position:0% +preceding that and now we're up to the +last thing that we had on our original + + align:start position:0% +last thing that we had on our original + + + align:start position:0% +last thing that we had on our original +list which are catalysts So today we're + + align:start position:0% +list which are catalysts So today we're + + + align:start position:0% +list which are catalysts So today we're +going to talk about + + align:start position:0% + + + + align:start position:0% + +catalysis so this is on the lecture + + align:start position:0% +catalysis so this is on the lecture + + + align:start position:0% +catalysis so this is on the lecture +summaries that will arrive for you um + + align:start position:0% +summaries that will arrive for you um + + + align:start position:0% +summaries that will arrive for you um +so a catalyst is a substance that takes + + align:start position:0% +so a catalyst is a substance that takes + + + align:start position:0% +so a catalyst is a substance that takes +part in the reaction but isn't consumed + + align:start position:0% +part in the reaction but isn't consumed + + + align:start position:0% +part in the reaction but isn't consumed +in the reaction so it's it's a bystander + + align:start position:0% +in the reaction so it's it's a bystander + + + align:start position:0% +in the reaction so it's it's a bystander +of the reaction it'll speed it up but it + + align:start position:0% +of the reaction it'll speed it up but it + + + align:start position:0% +of the reaction it'll speed it up but it +doesn't undergo any permanent change + + align:start position:0% +doesn't undergo any permanent change + + + align:start position:0% +doesn't undergo any permanent change +itself so that's the definition of a + + align:start position:0% +itself so that's the definition of a + + + align:start position:0% +itself so that's the definition of a +catalyst so catalysts because they're + + align:start position:0% +catalyst so catalysts because they're + + + align:start position:0% +catalyst so catalysts because they're +not uh changing in their form are not + + align:start position:0% +not uh changing in their form are not + + + align:start position:0% +not uh changing in their form are not +part of an overall balanced equation so + + align:start position:0% +part of an overall balanced equation so + + + align:start position:0% +part of an overall balanced equation so +sometimes you'll see a balanced equation + + align:start position:0% +sometimes you'll see a balanced equation + + + align:start position:0% +sometimes you'll see a balanced equation +and a thing over the arrow which will + + align:start position:0% +and a thing over the arrow which will + + + align:start position:0% +and a thing over the arrow which will +indicate the conditions in which the + + align:start position:0% +indicate the conditions in which the + + + align:start position:0% +indicate the conditions in which the +reaction was done and often uh + + align:start position:0% +reaction was done and often uh + + + align:start position:0% +reaction was done and often uh +information about a catalyst that was + + align:start position:0% +information about a catalyst that was + + + align:start position:0% +information about a catalyst that was +used in the reaction uh will will take + + align:start position:0% +used in the reaction uh will will take + + + align:start position:0% +used in the reaction uh will will take +will be present there so what are + + align:start position:0% +will be present there so what are + + + align:start position:0% +will be present there so what are +catalysts actually + + align:start position:0% +catalysts actually + + + align:start position:0% +catalysts actually +doing so here is the uh potential uh + + align:start position:0% +doing so here is the uh potential uh + + + align:start position:0% +doing so here is the uh potential uh +energy diagram that we looked at last + + align:start position:0% +energy diagram that we looked at last + + + align:start position:0% +energy diagram that we looked at last +time and in this diagram you have uh + + align:start position:0% +time and in this diagram you have uh + + + align:start position:0% +time and in this diagram you have uh +some energy for reactants uh energy for + + align:start position:0% +some energy for reactants uh energy for + + + align:start position:0% +some energy for reactants uh energy for +products down here there's an overall + + align:start position:0% +products down here there's an overall + + + align:start position:0% +products down here there's an overall +change Delta e uh between the reactants + + align:start position:0% +change Delta e uh between the reactants + + + align:start position:0% +change Delta e uh between the reactants +and the products and again Delta e is + + align:start position:0% +and the products and again Delta e is + + + align:start position:0% +and the products and again Delta e is +very similar to Delta H um it's only one + + align:start position:0% +very similar to Delta H um it's only one + + + align:start position:0% +very similar to Delta H um it's only one +or two% off for gases and almost the + + align:start position:0% +or two% off for gases and almost the + + + align:start position:0% +or two% off for gases and almost the +same for liquids and solids um so that's + + align:start position:0% +same for liquids and solids um so that's + + + align:start position:0% +same for liquids and solids um so that's +uh information about the thermodynamics + + align:start position:0% +uh information about the thermodynamics + + + align:start position:0% +uh information about the thermodynamics +this is a calorimetry a thermodynamic + + align:start position:0% +this is a calorimetry a thermodynamic + + + align:start position:0% +this is a calorimetry a thermodynamic +measurement and then we saw that there's + + align:start position:0% +measurement and then we saw that there's + + + align:start position:0% +measurement and then we saw that there's +an activation energy and this is EA for + + align:start position:0% +an activation energy and this is EA for + + + align:start position:0% +an activation energy and this is EA for +the forward reaction uh that the + + align:start position:0% +the forward reaction uh that the + + + align:start position:0% +the forward reaction uh that the +molecules need to overcome critical + + align:start position:0% +molecules need to overcome critical + + + align:start position:0% +molecules need to overcome critical +energy that they need to overcome before + + align:start position:0% +energy that they need to overcome before + + + align:start position:0% +energy that they need to overcome before +they can go on and form products and + + align:start position:0% +they can go on and form products and + + + align:start position:0% +they can go on and form products and +that's uh that energy barrier is there + + align:start position:0% +that's uh that energy barrier is there + + + align:start position:0% +that's uh that energy barrier is there +because when molecules come together and + + align:start position:0% +because when molecules come together and + + + align:start position:0% +because when molecules come together and +attempt to react usually there's some + + align:start position:0% +attempt to react usually there's some + + + align:start position:0% +attempt to react usually there's some +amount of bond Distortion that has to + + align:start position:0% +amount of bond Distortion that has to + + + align:start position:0% +amount of bond Distortion that has to +occur things are + + align:start position:0% +occur things are + + + align:start position:0% +occur things are +rearranging and you form usually some + + align:start position:0% +rearranging and you form usually some + + + align:start position:0% +rearranging and you form usually some +kind of intermediate activated complex + + align:start position:0% +kind of intermediate activated complex + + + align:start position:0% +kind of intermediate activated complex +or transition state and when you get up + + align:start position:0% +or transition state and when you get up + + + align:start position:0% +or transition state and when you get up +there if the molecules have enough + + align:start position:0% +there if the molecules have enough + + + align:start position:0% +there if the molecules have enough +energy to react then they can go down to + + align:start position:0% +energy to react then they can go down to + + + align:start position:0% +energy to react then they can go down to +products if they don't have enough + + align:start position:0% +products if they don't have enough + + + align:start position:0% +products if they don't have enough +energy to react if there's not enough + + align:start position:0% +energy to react if there's not enough + + + align:start position:0% +energy to react if there's not enough +energy uh to distort those bonds and + + align:start position:0% +energy uh to distort those bonds and + + + align:start position:0% +energy uh to distort those bonds and +form this activated complex then they'll + + align:start position:0% +form this activated complex then they'll + + + align:start position:0% +form this activated complex then they'll +fall back apart to reactants so for an + + align:start position:0% +fall back apart to reactants so for an + + + align:start position:0% +fall back apart to reactants so for an +elementary reaction there's always some + + align:start position:0% +elementary reaction there's always some + + + align:start position:0% +elementary reaction there's always some +barrier to overcome and uh I I think + + align:start position:0% +barrier to overcome and uh I I think + + + align:start position:0% +barrier to overcome and uh I I think +about activation energy barriers in my + + align:start position:0% +about activation energy barriers in my + + + align:start position:0% +about activation energy barriers in my +own work all the time it seems like you + + align:start position:0% +own work all the time it seems like you + + + align:start position:0% +own work all the time it seems like you +know whenever I have to sit down and do + + align:start position:0% +know whenever I have to sit down and do + + + align:start position:0% +know whenever I have to sit down and do +something uh write a paper start writing + + align:start position:0% +something uh write a paper start writing + + + align:start position:0% +something uh write a paper start writing +a paper write a grant write the final + + align:start position:0% +a paper write a grant write the final + + + align:start position:0% +a paper write a grant write the final +exam there always seems to be some + + align:start position:0% +exam there always seems to be some + + + align:start position:0% +exam there always seems to be some +activation energy barrier to getting + + align:start position:0% +activation energy barrier to getting + + + align:start position:0% +activation energy barrier to getting +started and once you get started then + + align:start position:0% +started and once you get started then + + + align:start position:0% +started and once you get started then +then you uh if you get to this point uh + + align:start position:0% +then you uh if you get to this point uh + + + align:start position:0% +then you uh if you get to this point uh +then it's all downhill and things go + + align:start position:0% +then it's all downhill and things go + + + align:start position:0% +then it's all downhill and things go +much more smoothly but in the beginning + + align:start position:0% +much more smoothly but in the beginning + + + align:start position:0% +much more smoothly but in the beginning +it always seems like every reaction or + + align:start position:0% +it always seems like every reaction or + + + align:start position:0% +it always seems like every reaction or +every task has some kind of activation + + align:start position:0% +every task has some kind of activation + + + align:start position:0% +every task has some kind of activation +energy barrier so up at this top part + + align:start position:0% +energy barrier so up at this top part + + + align:start position:0% +energy barrier so up at this top part +there with this dash line then there's a + + align:start position:0% +there with this dash line then there's a + + + align:start position:0% +there with this dash line then there's a +transition state or an activated complex + + align:start position:0% +transition state or an activated complex + + + align:start position:0% +transition state or an activated complex +and here's the barrier without the + + align:start position:0% +and here's the barrier without the + + + align:start position:0% +and here's the barrier without the +Catalyst here's the energy barrier + + align:start position:0% +Catalyst here's the energy barrier + + + align:start position:0% +Catalyst here's the energy barrier +without the Catalyst and the line for + + align:start position:0% +without the Catalyst and the line for + + + align:start position:0% +without the Catalyst and the line for +the transition state and again if we go + + align:start position:0% +the transition state and again if we go + + + align:start position:0% +the transition state and again if we go +in the reverse direction of this there's + + align:start position:0% +in the reverse direction of this there's + + + align:start position:0% +in the reverse direction of this there's +an activation energy for the reverse + + align:start position:0% +an activation energy for the reverse + + + align:start position:0% +an activation energy for the reverse +reaction here and these will all sum up + + align:start position:0% +reaction here and these will all sum up + + + align:start position:0% +reaction here and these will all sum up +so Delta e is going to be equal to the + + align:start position:0% +so Delta e is going to be equal to the + + + align:start position:0% +so Delta e is going to be equal to the +activation energy for the forward + + align:start position:0% +activation energy for the forward + + + align:start position:0% +activation energy for the forward +reaction minus the activation energy for + + align:start position:0% +reaction minus the activation energy for + + + align:start position:0% +reaction minus the activation energy for +the reverse reaction so what does adding + + align:start position:0% +the reverse reaction so what does adding + + + align:start position:0% +the reverse reaction so what does adding +a catalyst do well adding a catalyst + + align:start position:0% +a catalyst do well adding a catalyst + + + align:start position:0% +a catalyst do well adding a catalyst +lowers that activation energy barrier so + + align:start position:0% +lowers that activation energy barrier so + + + align:start position:0% +lowers that activation energy barrier so +that's shown here in the blue line and + + align:start position:0% +that's shown here in the blue line and + + + align:start position:0% +that's shown here in the blue line and +this is also uh in the + + align:start position:0% +this is also uh in the + + + align:start position:0% +this is also uh in the +handout so this is the energy barrier um + + align:start position:0% +handout so this is the energy barrier um + + + align:start position:0% +handout so this is the energy barrier um +with a catalyst so it's lower and then + + align:start position:0% +with a catalyst so it's lower and then + + + align:start position:0% +with a catalyst so it's lower and then +the transition state with the Catalyst + + align:start position:0% +the transition state with the Catalyst + + + align:start position:0% +the transition state with the Catalyst +will also be slow be lower and so one + + align:start position:0% +will also be slow be lower and so one + + + align:start position:0% +will also be slow be lower and so one +way that you can think about this is + + align:start position:0% +way that you can think about this is + + + align:start position:0% +way that you can think about this is +that a catalyst lowers um or stabilizes + + align:start position:0% +that a catalyst lowers um or stabilizes + + + align:start position:0% +that a catalyst lowers um or stabilizes +the transition state + + align:start position:0% +the transition state + + + align:start position:0% +the transition state +all right so let's add a few more things + + align:start position:0% +all right so let's add a few more things + + + align:start position:0% +all right so let's add a few more things +to this diagram + + align:start position:0% +to this diagram + + + align:start position:0% +to this diagram +then so there'll be a new activation + + align:start position:0% +then so there'll be a new activation + + + align:start position:0% +then so there'll be a new activation +energy for the forward reaction shown in + + align:start position:0% +energy for the forward reaction shown in + + + align:start position:0% +energy for the forward reaction shown in +blue it's not as high a barrier now it's + + align:start position:0% +blue it's not as high a barrier now it's + + + align:start position:0% +blue it's not as high a barrier now it's +lowered down and there will be a new + + align:start position:0% +lowered down and there will be a new + + + align:start position:0% +lowered down and there will be a new +activation energy for the reverse + + align:start position:0% +activation energy for the reverse + + + align:start position:0% +activation energy for the reverse +reaction uh shown in blue so these are + + align:start position:0% +reaction uh shown in blue so these are + + + align:start position:0% +reaction uh shown in blue so these are +the values then with a catalyst so a + + align:start position:0% +the values then with a catalyst so a + + + align:start position:0% +the values then with a catalyst so a +catalyst is going to lower both the + + align:start position:0% +catalyst is going to lower both the + + + align:start position:0% +catalyst is going to lower both the +activation energy for the forward + + align:start position:0% +activation energy for the forward + + + align:start position:0% +activation energy for the forward +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +and the activation energy for the + + align:start position:0% +and the activation energy for the + + + align:start position:0% +and the activation energy for the +reverse + + align:start position:0% +reverse + + + align:start position:0% +reverse +reaction and uh that's what said here so + + align:start position:0% +reaction and uh that's what said here so + + + align:start position:0% +reaction and uh that's what said here so +it lowers both both barriers forward and + + align:start position:0% + + + + align:start position:0% + +reverse and another way to express this + + align:start position:0% +reverse and another way to express this + + + align:start position:0% +reverse and another way to express this +is that the Catal Catalyst stabilize + + align:start position:0% +is that the Catal Catalyst stabilize + + + align:start position:0% +is that the Catal Catalyst stabilize +this transition state or activated + + align:start position:0% +this transition state or activated + + + align:start position:0% +this transition state or activated +complex so they're going to lower the + + align:start position:0% +complex so they're going to lower the + + + align:start position:0% +complex so they're going to lower the +energy or stabilize that state and this + + align:start position:0% +energy or stabilize that state and this + + + align:start position:0% +energy or stabilize that state and this +way of thinking about this will come + + align:start position:0% +way of thinking about this will come + + + align:start position:0% +way of thinking about this will come +back to at the end of the lecture it's + + align:start position:0% +back to at the end of the lecture it's + + + align:start position:0% +back to at the end of the lecture it's +something that's used U by + + align:start position:0% +something that's used U by + + + align:start position:0% +something that's used U by +pharmaceutical companies in terms of + + align:start position:0% +pharmaceutical companies in terms of + + + align:start position:0% +pharmaceutical companies in terms of +Designing uh uh Inhibitors of enzymes to + + align:start position:0% +Designing uh uh Inhibitors of enzymes to + + + align:start position:0% +Designing uh uh Inhibitors of enzymes to +think about uh + + align:start position:0% +think about uh + + + align:start position:0% +think about uh +this so catalysts have no effect on the + + align:start position:0% +this so catalysts have no effect on the + + + align:start position:0% +this so catalysts have no effect on the +thermodynamics of the reaction so + + align:start position:0% +thermodynamics of the reaction so + + + align:start position:0% +thermodynamics of the reaction so +they're affecting the rate of the + + align:start position:0% +they're affecting the rate of the + + + align:start position:0% +they're affecting the rate of the +reaction but not the thermodynamics of + + align:start position:0% +reaction but not the thermodynamics of + + + align:start position:0% +reaction but not the thermodynamics of +the reaction you see that Delta e is not + + align:start position:0% +the reaction you see that Delta e is not + + + align:start position:0% +the reaction you see that Delta e is not +changing in this at all it's the same uh + + align:start position:0% +changing in this at all it's the same uh + + + align:start position:0% +changing in this at all it's the same uh +same energy difference between reactants + + align:start position:0% +same energy difference between reactants + + + align:start position:0% +same energy difference between reactants +and products so that term is is not + + align:start position:0% +and products so that term is is not + + + align:start position:0% +and products so that term is is not +changing and so uh also Delta Delta G uh + + align:start position:0% +changing and so uh also Delta Delta G uh + + + align:start position:0% +changing and so uh also Delta Delta G uh +would not change Delta G is a state + + align:start position:0% +would not change Delta G is a state + + + align:start position:0% +would not change Delta G is a state +function it's independent of the path so + + align:start position:0% +function it's independent of the path so + + + align:start position:0% +function it's independent of the path so +it is not going to change it doesn't + + align:start position:0% +it is not going to change it doesn't + + + align:start position:0% +it is not going to change it doesn't +care if it had to go over a higher + + align:start position:0% +care if it had to go over a higher + + + align:start position:0% +care if it had to go over a higher +barrier or a lower barrier it's + + align:start position:0% +barrier or a lower barrier it's + + + align:start position:0% +barrier or a lower barrier it's +independent of the path of the reaction + + align:start position:0% +independent of the path of the reaction + + + align:start position:0% +independent of the path of the reaction +it just uh cares about uh where it ends + + align:start position:0% +it just uh cares about uh where it ends + + + align:start position:0% +it just uh cares about uh where it ends +up so Delta G is not going to change + + align:start position:0% +up so Delta G is not going to change + + + align:start position:0% +up so Delta G is not going to change +with a catalyst uh therefore equilibrium + + align:start position:0% +with a catalyst uh therefore equilibrium + + + align:start position:0% +with a catalyst uh therefore equilibrium +constants not going to change with a + + align:start position:0% +constants not going to change with a + + + align:start position:0% +constants not going to change with a +catalyst so what you're changing is the + + align:start position:0% +catalyst so what you're changing is the + + + align:start position:0% +catalyst so what you're changing is the +activation energy barriers again in the + + align:start position:0% +activation energy barriers again in the + + + align:start position:0% +activation energy barriers again in the +Ford and the uh reverse reaction and + + align:start position:0% +Ford and the uh reverse reaction and + + + align:start position:0% +Ford and the uh reverse reaction and +you're speeding up then the + + align:start position:0% +you're speeding up then the + + + align:start position:0% +you're speeding up then the +reaction so um the uh the Chinese symbol + + align:start position:0% +reaction so um the uh the Chinese symbol + + + align:start position:0% +reaction so um the uh the Chinese symbol +for a catalyst is a marriage counselor + + align:start position:0% +for a catalyst is a marriage counselor + + + align:start position:0% +for a catalyst is a marriage counselor +so you can think about the catalyst as + + align:start position:0% +so you can think about the catalyst as + + + align:start position:0% +so you can think about the catalyst as +really facilitating those molecules + + align:start position:0% +really facilitating those molecules + + + align:start position:0% +really facilitating those molecules +coming together and having enough uh + + align:start position:0% +coming together and having enough uh + + + align:start position:0% +coming together and having enough uh +energy to react so say if they were at a + + align:start position:0% +energy to react so say if they were at a + + + align:start position:0% +energy to react so say if they were at a +lower temperature it would be harder to + + align:start position:0% +lower temperature it would be harder to + + + align:start position:0% +lower temperature it would be harder to +get over that activation energy barrier + + align:start position:0% +get over that activation energy barrier + + + align:start position:0% +get over that activation energy barrier +so a catalyst or or a molecule uh + + align:start position:0% +so a catalyst or or a molecule uh + + + align:start position:0% +so a catalyst or or a molecule uh +counselor will uh help lower that + + align:start position:0% +counselor will uh help lower that + + + align:start position:0% +counselor will uh help lower that +barrier and make it more more likely uh + + align:start position:0% +barrier and make it more more likely uh + + + align:start position:0% +barrier and make it more more likely uh +for these molecules to have that energy + + align:start position:0% +for these molecules to have that energy + + + align:start position:0% +for these molecules to have that energy +to react and go on to product and uh + + align:start position:0% +to react and go on to product and uh + + + align:start position:0% +to react and go on to product and uh +that'll uh speed up the reaction + + align:start position:0% +that'll uh speed up the reaction + + + align:start position:0% +that'll uh speed up the reaction +so we talked last time about if you're + + align:start position:0% +so we talked last time about if you're + + + align:start position:0% +so we talked last time about if you're +at high temperature or low temperature + + align:start position:0% +at high temperature or low temperature + + + align:start position:0% +at high temperature or low temperature +if you're at higher temperature more + + align:start position:0% +if you're at higher temperature more + + + align:start position:0% +if you're at higher temperature more +molecules can overcome the barrier lower + + align:start position:0% +molecules can overcome the barrier lower + + + align:start position:0% +molecules can overcome the barrier lower +molec lower uh temperature makes it + + align:start position:0% +molec lower uh temperature makes it + + + align:start position:0% +molec lower uh temperature makes it +harder to do that so a catalyst + + align:start position:0% +harder to do that so a catalyst + + + align:start position:0% +harder to do that so a catalyst +facilitates things by making the barrier + + align:start position:0% +facilitates things by making the barrier + + + align:start position:0% +facilitates things by making the barrier +lower so that's uh what a catalyst can + + align:start position:0% +lower so that's uh what a catalyst can + + + align:start position:0% +lower so that's uh what a catalyst can +do and in terms of your own thinking + + align:start position:0% +do and in terms of your own thinking + + + align:start position:0% +do and in terms of your own thinking +about things uh if you have big + + align:start position:0% +about things uh if you have big + + + align:start position:0% +about things uh if you have big +activation energy barriers for say + + align:start position:0% +activation energy barriers for say + + + align:start position:0% +activation energy barriers for say +studying for things or writing a final + + align:start position:0% +studying for things or writing a final + + + align:start position:0% +studying for things or writing a final +paper you can think of catalysts as + + align:start position:0% +paper you can think of catalysts as + + + align:start position:0% +paper you can think of catalysts as +being uh the due date being the next day + + align:start position:0% +being uh the due date being the next day + + + align:start position:0% +being uh the due date being the next day +uh so you've run out of time that can be + + align:start position:0% +uh so you've run out of time that can be + + + align:start position:0% +uh so you've run out of time that can be +a big Catalyst and lowering that barrier + + align:start position:0% +a big Catalyst and lowering that barrier + + + align:start position:0% +a big Catalyst and lowering that barrier +and helping you get started uh caffeine + + align:start position:0% +and helping you get started uh caffeine + + + align:start position:0% +and helping you get started uh caffeine +uh works for a lot of people in terms of + + align:start position:0% +uh works for a lot of people in terms of + + + align:start position:0% +uh works for a lot of people in terms of +uh getting over those activation energy + + align:start position:0% +uh getting over those activation energy + + + align:start position:0% +uh getting over those activation energy +barriers so you can think about in your + + align:start position:0% +barriers so you can think about in your + + + align:start position:0% +barriers so you can think about in your +own life what are good catalysts that uh + + align:start position:0% +own life what are good catalysts that uh + + + align:start position:0% +own life what are good catalysts that uh +that help you uh get over those + + align:start position:0% +that help you uh get over those + + + align:start position:0% +that help you uh get over those +barriers okay so an inhibitor then would + + align:start position:0% +barriers okay so an inhibitor then would + + + align:start position:0% +barriers okay so an inhibitor then would +be the opposite of a catalyst and uh it + + align:start position:0% +be the opposite of a catalyst and uh it + + + align:start position:0% +be the opposite of a catalyst and uh it +will it will slow the rate of a reaction + + align:start position:0% +will it will slow the rate of a reaction + + + align:start position:0% +will it will slow the rate of a reaction +and it can increase the activation + + align:start position:0% +and it can increase the activation + + + align:start position:0% +and it can increase the activation +energy barrier so an inhibitor is going + + align:start position:0% +energy barrier so an inhibitor is going + + + align:start position:0% +energy barrier so an inhibitor is going +to be the opposite and again uh we'll + + align:start position:0% +to be the opposite and again uh we'll + + + align:start position:0% +to be the opposite and again uh we'll +talk more about Inhibitors at the end of + + align:start position:0% +talk more about Inhibitors at the end of + + + align:start position:0% +talk more about Inhibitors at the end of +today's + + align:start position:0% + + + + align:start position:0% + +class so there are a couple types of + + align:start position:0% +class so there are a couple types of + + + align:start position:0% +class so there are a couple types of +catalysts so you can talk about a + + align:start position:0% +catalysts so you can talk about a + + + align:start position:0% +catalysts so you can talk about a +homogeneous catalyst and that is when + + align:start position:0% +homogeneous catalyst and that is when + + + align:start position:0% +homogeneous catalyst and that is when +the reactant and the catalyst are in the + + align:start position:0% +the reactant and the catalyst are in the + + + align:start position:0% +the reactant and the catalyst are in the +same phase so an example would be uh in + + align:start position:0% +same phase so an example would be uh in + + + align:start position:0% +same phase so an example would be uh in +the depletion of the ozone layer uh by + + align:start position:0% +the depletion of the ozone layer uh by + + + align:start position:0% +the depletion of the ozone layer uh by +uh + + align:start position:0% +uh + + + align:start position:0% +uh +chlorofluorocarbons those are all in the + + align:start position:0% +chlorofluorocarbons those are all in the + + + align:start position:0% +chlorofluorocarbons those are all in the +gas phase so uh this acts as a catalyst + + align:start position:0% +gas phase so uh this acts as a catalyst + + + align:start position:0% +gas phase so uh this acts as a catalyst +it catalyzes the depletion of ozone + + align:start position:0% +it catalyzes the depletion of ozone + + + align:start position:0% +it catalyzes the depletion of ozone +which is why people uh have been very + + align:start position:0% +which is why people uh have been very + + + align:start position:0% +which is why people uh have been very +concerned about uh uh spray cans and + + align:start position:0% +concerned about uh uh spray cans and + + + align:start position:0% +concerned about uh uh spray cans and +other things that release uh these uh + + align:start position:0% +other things that release uh these uh + + + align:start position:0% +other things that release uh these uh +these molecules into the environment you + + align:start position:0% +these molecules into the environment you + + + align:start position:0% +these molecules into the environment you +can also have heterogeneous catalyst so + + align:start position:0% +can also have heterogeneous catalyst so + + + align:start position:0% +can also have heterogeneous catalyst so +something that's in a different phase as + + align:start position:0% +something that's in a different phase as + + + align:start position:0% +something that's in a different phase as +the reacting + + align:start position:0% +the reacting + + + align:start position:0% +the reacting +molecules and we're all familiar with + + align:start position:0% +molecules and we're all familiar with + + + align:start position:0% +molecules and we're all familiar with +examples of this like a catalytic + + align:start position:0% +examples of this like a catalytic + + + align:start position:0% +examples of this like a catalytic +converter so uh in this case you might + + align:start position:0% +converter so uh in this case you might + + + align:start position:0% +converter so uh in this case you might +have your Catalyst would be solid Metals + + align:start position:0% +have your Catalyst would be solid Metals + + + align:start position:0% +have your Catalyst would be solid Metals +uh platinum plaum rodium and they will + + align:start position:0% +uh platinum plaum rodium and they will + + + align:start position:0% +uh platinum plaum rodium and they will +help uh catalyze oxidation of + + align:start position:0% +help uh catalyze oxidation of + + + align:start position:0% +help uh catalyze oxidation of +hydrocarbon Co gases um reduction of + + align:start position:0% +hydrocarbon Co gases um reduction of + + + align:start position:0% +hydrocarbon Co gases um reduction of +nitrogen oxides so to reduce pollution + + align:start position:0% +nitrogen oxides so to reduce pollution + + + align:start position:0% +nitrogen oxides so to reduce pollution +so the reactant molecules are gas passes + + align:start position:0% +so the reactant molecules are gas passes + + + align:start position:0% +so the reactant molecules are gas passes +but the catalyst is a metal so it's + + align:start position:0% +but the catalyst is a metal so it's + + + align:start position:0% +but the catalyst is a metal so it's +heterogeneous it's in a different phase + + align:start position:0% +heterogeneous it's in a different phase + + + align:start position:0% +heterogeneous it's in a different phase +uh so these two + + align:start position:0% +uh so these two + + + align:start position:0% +uh so these two +examples so I'll just show you a little + + align:start position:0% +examples so I'll just show you a little + + + align:start position:0% +examples so I'll just show you a little +movie of heterogeneous uh + + align:start position:0% +movie of heterogeneous uh + + + align:start position:0% +movie of heterogeneous uh +catalysis do you + + align:start position:0% +catalysis do you + + + align:start position:0% +catalysis do you +want yes could some of the Tas help the + + align:start position:0% +want yes could some of the Tas help the + + + align:start position:0% +want yes could some of the Tas help the +lecture notes are + + align:start position:0% +lecture notes are + + + align:start position:0% +lecture notes are +here so uh this movie is not in the + + align:start position:0% +here so uh this movie is not in the + + + align:start position:0% +here so uh this movie is not in the +lecture notes but um anyway so we have + + align:start position:0% +lecture notes but um anyway so we have + + + align:start position:0% +lecture notes but um anyway so we have +here a metal surface in blue + + align:start position:0% +here a metal surface in blue + + + align:start position:0% +here a metal surface in blue +and the metal is acting as a catalyst + + align:start position:0% +and the metal is acting as a catalyst + + + align:start position:0% +and the metal is acting as a catalyst +and uh in Gray we have these two dots + + align:start position:0% +and uh in Gray we have these two dots + + + align:start position:0% +and uh in Gray we have these two dots +those are hydrogens so what the metal + + align:start position:0% +those are hydrogens so what the metal + + + align:start position:0% +those are hydrogens so what the metal +did was helped to facilitate the + + align:start position:0% +did was helped to facilitate the + + + align:start position:0% +did was helped to facilitate the +dissociation of + + align:start position:0% +dissociation of + + + align:start position:0% +dissociation of +H2 so H2 which is not so reactive has + + align:start position:0% +H2 so H2 which is not so reactive has + + + align:start position:0% +H2 so H2 which is not so reactive has +been dissociated and you have uh broken + + align:start position:0% +been dissociated and you have uh broken + + + align:start position:0% +been dissociated and you have uh broken +into the two separate hydrogens and now + + align:start position:0% +into the two separate hydrogens and now + + + align:start position:0% +into the two separate hydrogens and now +if we bring in um a + + align:start position:0% +if we bring in um a + + + align:start position:0% +if we bring in um a +uh molecule of + + align:start position:0% +uh molecule of + + + align:start position:0% +uh molecule of +um of ethane then it will react with + + align:start position:0% +um of ethane then it will react with + + + align:start position:0% +um of ethane then it will react with +um react with this so you have a + + align:start position:0% +um react with this so you have a + + + align:start position:0% +um react with this so you have a +molecule come in in a different phase + + align:start position:0% +molecule come in in a different phase + + + align:start position:0% +molecule come in in a different phase +and see how the hydrogens just kind of + + align:start position:0% +and see how the hydrogens just kind of + + + align:start position:0% +and see how the hydrogens just kind of +Bop right on uh to the molecule so the + + align:start position:0% +Bop right on uh to the molecule so the + + + align:start position:0% +Bop right on uh to the molecule so the +metal surface was acting as a catalyst + + align:start position:0% +metal surface was acting as a catalyst + + + align:start position:0% +metal surface was acting as a catalyst +making the H2 gas I'll just do that one + + align:start position:0% +making the H2 gas I'll just do that one + + + align:start position:0% +making the H2 gas I'll just do that one +more time the H2 gas more reactive by + + align:start position:0% +more time the H2 gas more reactive by + + + align:start position:0% +more time the H2 gas more reactive by +having a dissociate first now they're + + align:start position:0% +having a dissociate first now they're + + + align:start position:0% +having a dissociate first now they're +sitting on the metal surface and the + + align:start position:0% +sitting on the metal surface and the + + + align:start position:0% +sitting on the metal surface and the +reaction uh is quite a bit faster + + align:start position:0% +reaction uh is quite a bit faster + + + align:start position:0% +reaction uh is quite a bit faster +so that would be an example of the + + align:start position:0% +so that would be an example of the + + + align:start position:0% +so that would be an example of the +heterogeneous uh + + align:start position:0% + + + + align:start position:0% + +catalysis all right so now I'm going to + + align:start position:0% +catalysis all right so now I'm going to + + + align:start position:0% +catalysis all right so now I'm going to +talk about my favorite kind of + + align:start position:0% +talk about my favorite kind of + + + align:start position:0% +talk about my favorite kind of +catalyst so catalysts of life or + + align:start position:0% +catalyst so catalysts of life or + + + align:start position:0% +catalyst so catalysts of life or +enzymes so enzymes are catalysts and if + + align:start position:0% +enzymes so enzymes are catalysts and if + + + align:start position:0% +enzymes so enzymes are catalysts and if +you're a biochemist enzymes are your + + align:start position:0% +you're a biochemist enzymes are your + + + align:start position:0% +you're a biochemist enzymes are your +favorite kind of + + align:start position:0% +favorite kind of + + + align:start position:0% +favorite kind of +catalyst so an enzyme uh is usually a + + align:start position:0% +catalyst so an enzyme uh is usually a + + + align:start position:0% +catalyst so an enzyme uh is usually a +protein there are some examples of uh + + align:start position:0% +protein there are some examples of uh + + + align:start position:0% +protein there are some examples of uh +RNA catalyzing reactions but most + + align:start position:0% +RNA catalyzing reactions but most + + + align:start position:0% +RNA catalyzing reactions but most +enzymes are made up of + + align:start position:0% +enzymes are made up of + + + align:start position:0% +enzymes are made up of +protein and uh they're usually fairly + + align:start position:0% +protein and uh they're usually fairly + + + align:start position:0% +protein and uh they're usually fairly +large so TP the sort of smallest + + align:start position:0% +large so TP the sort of smallest + + + align:start position:0% +large so TP the sort of smallest +molecular weight you might see would be + + align:start position:0% +molecular weight you might see would be + + + align:start position:0% +molecular weight you might see would be +about uh 20,000 uh grams per mole and + + align:start position:0% +about uh 20,000 uh grams per mole and + + + align:start position:0% +about uh 20,000 uh grams per mole and +again uh some people on exam 3 I'll just + + align:start position:0% +again uh some people on exam 3 I'll just + + + align:start position:0% +again uh some people on exam 3 I'll just +point this out when I asked for units of + + align:start position:0% +point this out when I asked for units of + + + align:start position:0% +point this out when I asked for units of +molecular weight um units of molecular + + align:start position:0% +molecular weight um units of molecular + + + align:start position:0% +molecular weight um units of molecular +weight grams per mole so uh some people + + align:start position:0% +weight grams per mole so uh some people + + + align:start position:0% +weight grams per mole so uh some people +uh didn't have the right units for that + + align:start position:0% +uh didn't have the right units for that + + + align:start position:0% +uh didn't have the right units for that +uh and that's you know the same uh + + align:start position:0% +uh and that's you know the same uh + + + align:start position:0% +uh and that's you know the same uh +molecular weight if you're talking about + + align:start position:0% +molecular weight if you're talking about + + + align:start position:0% +molecular weight if you're talking about +a weak acid or you're talking about an + + align:start position:0% +a weak acid or you're talking about an + + + align:start position:0% +a weak acid or you're talking about an +enzyme uh same units but different size + + align:start position:0% +enzyme uh same units but different size + + + align:start position:0% +enzyme uh same units but different size +so these enzymes are are capable of + + align:start position:0% +so these enzymes are are capable of + + + align:start position:0% +so these enzymes are are capable of +catalyzing a wide variety of different + + align:start position:0% +catalyzing a wide variety of different + + + align:start position:0% +catalyzing a wide variety of different +reactions in your + + align:start position:0% +reactions in your + + + align:start position:0% +reactions in your +body + + align:start position:0% +body + + + align:start position:0% +body +so uh proteins or enzymes are made up of + + align:start position:0% +so uh proteins or enzymes are made up of + + + align:start position:0% +so uh proteins or enzymes are made up of +amino acids and and amino acids have + + align:start position:0% +amino acids and and amino acids have + + + align:start position:0% +amino acids and and amino acids have +carbon nitrogen oxygen sulfur uh in + + align:start position:0% +carbon nitrogen oxygen sulfur uh in + + + align:start position:0% +carbon nitrogen oxygen sulfur uh in +them and uh I'll just um I'll I'll share + + align:start position:0% +them and uh I'll just um I'll I'll share + + + align:start position:0% +them and uh I'll just um I'll I'll share +with you a little recent story we have a + + align:start position:0% +with you a little recent story we have a + + + align:start position:0% +with you a little recent story we have a +collaborator who's in France and they + + align:start position:0% +collaborator who's in France and they + + + align:start position:0% +collaborator who's in France and they +tried to send us uh some protein uh to + + align:start position:0% +tried to send us uh some protein uh to + + + align:start position:0% +tried to send us uh some protein uh to +do uh crystallization + + align:start position:0% +do uh crystallization + + + align:start position:0% +do uh crystallization +experiments and so uh we got I got a + + align:start position:0% +experiments and so uh we got I got a + + + align:start position:0% +experiments and so uh we got I got a +call from um customs in uh the so there + + align:start position:0% +call from um customs in uh the so there + + + align:start position:0% +call from um customs in uh the so there +was a doer with this protein sitting in + + align:start position:0% +was a doer with this protein sitting in + + + align:start position:0% +was a doer with this protein sitting in +uh in newe Jersey and Customs was + + align:start position:0% +uh in newe Jersey and Customs was + + + align:start position:0% +uh in newe Jersey and Customs was +calling me and they said they couldn't + + align:start position:0% +calling me and they said they couldn't + + + align:start position:0% +calling me and they said they couldn't +release this material from from Customs + + align:start position:0% +release this material from from Customs + + + align:start position:0% +release this material from from Customs +uh without more information and they + + align:start position:0% +uh without more information and they + + + align:start position:0% +uh without more information and they +said it says that here the doer contains + + align:start position:0% +said it says that here the doer contains + + + align:start position:0% +said it says that here the doer contains +protein and we need to know what that + + align:start position:0% +protein and we need to know what that + + + align:start position:0% +protein and we need to know what that +protein is made of and we also needed to + + align:start position:0% +protein is made of and we also needed to + + + align:start position:0% +protein is made of and we also needed to +know who had manufactured the protein + + align:start position:0% +know who had manufactured the protein + + + align:start position:0% +know who had manufactured the protein +and uh so um now you can all answer the + + align:start position:0% +and uh so um now you can all answer the + + + align:start position:0% +and uh so um now you can all answer the +question if Customs call proteins are + + align:start position:0% +question if Customs call proteins are + + + align:start position:0% +question if Customs call proteins are +made up of amino acids I'm not really + + align:start position:0% +made up of amino acids I'm not really + + + align:start position:0% +made up of amino acids I'm not really +sure what they were getting at here + + align:start position:0% +sure what they were getting at here + + + align:start position:0% +sure what they were getting at here +um and uh in terms of who had + + align:start position:0% +um and uh in terms of who had + + + align:start position:0% +um and uh in terms of who had +manufactured it it was ecoli bacteria um + + align:start position:0% +manufactured it it was ecoli bacteria um + + + align:start position:0% +manufactured it it was ecoli bacteria um +we were actually afraid of saying that + + align:start position:0% +we were actually afraid of saying that + + + align:start position:0% +we were actually afraid of saying that +because there are strains of ecoli that + + align:start position:0% +because there are strains of ecoli that + + + align:start position:0% +because there are strains of ecoli that +seem to every once in a while uh make + + align:start position:0% +seem to every once in a while uh make + + + align:start position:0% +seem to every once in a while uh make +people very sick at McDonald's and White + + align:start position:0% +people very sick at McDonald's and White + + + align:start position:0% +people very sick at McDonald's and White +Castle and places like that so ecoli has + + align:start position:0% +Castle and places like that so ecoli has + + + align:start position:0% +Castle and places like that so ecoli has +now become a sort of a dangerous uh + + align:start position:0% +now become a sort of a dangerous uh + + + align:start position:0% +now become a sort of a dangerous uh +bacteria so uh we said that it was + + align:start position:0% +bacteria so uh we said that it was + + + align:start position:0% +bacteria so uh we said that it was +protein was made up of amino acids like + + align:start position:0% +protein was made up of amino acids like + + + align:start position:0% +protein was made up of amino acids like +you buy at the health food store and + + align:start position:0% +you buy at the health food store and + + + align:start position:0% +you buy at the health food store and +that the uh manuf ufacturer was quote + + align:start position:0% +that the uh manuf ufacturer was quote + + + align:start position:0% +that the uh manuf ufacturer was quote +natural sources so uh the protein was + + align:start position:0% +natural sources so uh the protein was + + + align:start position:0% +natural sources so uh the protein was +released to us but apparently uh the + + align:start position:0% +released to us but apparently uh the + + + align:start position:0% +released to us but apparently uh the +person at Customs had not had Much + + align:start position:0% +person at Customs had not had Much + + + align:start position:0% +person at Customs had not had Much +Chemistry or biochemistry in their + + align:start position:0% +Chemistry or biochemistry in their + + + align:start position:0% +Chemistry or biochemistry in their +background all right so proteins are + + align:start position:0% +background all right so proteins are + + + align:start position:0% +background all right so proteins are +made up of these amino acids and here's + + align:start position:0% +made up of these amino acids and here's + + + align:start position:0% +made up of these amino acids and here's +an amino acid and Professor Sarah talked + + align:start position:0% +an amino acid and Professor Sarah talked + + + align:start position:0% +an amino acid and Professor Sarah talked +about this before in terms of Bad Hair + + align:start position:0% +about this before in terms of Bad Hair + + + align:start position:0% +about this before in terms of Bad Hair +Days um so an amino acid uh here we have + + align:start position:0% +Days um so an amino acid uh here we have + + + align:start position:0% +Days um so an amino acid uh here we have +an amino group a carboxilic group and a + + align:start position:0% +an amino group a carboxilic group and a + + + align:start position:0% +an amino group a carboxilic group and a +car which is called the alpha carbon + + align:start position:0% +car which is called the alpha carbon + + + align:start position:0% +car which is called the alpha carbon +it's sitting in the middle and there's a + + align:start position:0% +it's sitting in the middle and there's a + + + align:start position:0% +it's sitting in the middle and there's a +group R and that can be 20 different + + align:start position:0% +group R and that can be 20 different + + + align:start position:0% +group R and that can be 20 different +kinds of side chains that make up the 20 + + align:start position:0% +kinds of side chains that make up the 20 + + + align:start position:0% +kinds of side chains that make up the 20 +amino acids that are commonly found in + + align:start position:0% +amino acids that are commonly found in + + + align:start position:0% +amino acids that are commonly found in +proteins and so one amino acid gets + + align:start position:0% +proteins and so one amino acid gets + + + align:start position:0% +proteins and so one amino acid gets +linked to another amino acid uh by + + align:start position:0% +linked to another amino acid uh by + + + align:start position:0% +linked to another amino acid uh by +through What's called the peptide bond + + align:start position:0% +through What's called the peptide bond + + + align:start position:0% +through What's called the peptide bond +shown here and so here we have our first + + align:start position:0% +shown here and so here we have our first + + + align:start position:0% +shown here and so here we have our first +amino acid and our second and again you + + align:start position:0% +amino acid and our second and again you + + + align:start position:0% +amino acid and our second and again you +can have hundreds and hundreds of these + + align:start position:0% +can have hundreds and hundreds of these + + + align:start position:0% +can have hundreds and hundreds of these +amino acids connected to each other and + + align:start position:0% +amino acids connected to each other and + + + align:start position:0% +amino acids connected to each other and +then they fold up into into some kind of + + align:start position:0% +then they fold up into into some kind of + + + align:start position:0% +then they fold up into into some kind of +compact structure for the + + align:start position:0% + + + + align:start position:0% + +enzyme so in this particular case there + + align:start position:0% +enzyme so in this particular case there + + + align:start position:0% +enzyme so in this particular case there +are four different chains of peptides + + align:start position:0% +are four different chains of peptides + + + align:start position:0% +are four different chains of peptides +and each chain has 198 amino acids so + + align:start position:0% +and each chain has 198 amino acids so + + + align:start position:0% +and each chain has 198 amino acids so +each chain in this picture is shown in a + + align:start position:0% +each chain in this picture is shown in a + + + align:start position:0% +each chain in this picture is shown in a +different color uh yellow and green and + + align:start position:0% +different color uh yellow and green and + + + align:start position:0% +different color uh yellow and green and +red and blue and uh in these diagrams + + align:start position:0% +red and blue and uh in these diagrams + + + align:start position:0% +red and blue and uh in these diagrams +they can't they don't show all the atoms + + align:start position:0% +they can't they don't show all the atoms + + + align:start position:0% +they can't they don't show all the atoms +because that would just kind of be a big + + align:start position:0% +because that would just kind of be a big + + + align:start position:0% +because that would just kind of be a big +mess if you showed all the atoms but + + align:start position:0% +mess if you showed all the atoms but + + + align:start position:0% +mess if you showed all the atoms but +instead a ribbon is drawn through the + + align:start position:0% +instead a ribbon is drawn through the + + + align:start position:0% +instead a ribbon is drawn through the +positions of the Alpac carbons of every + + align:start position:0% +positions of the Alpac carbons of every + + + align:start position:0% +positions of the Alpac carbons of every +amino acid and so these uh kind of + + align:start position:0% +amino acid and so these uh kind of + + + align:start position:0% +amino acid and so these uh kind of +squirly things squiggly things here are + + align:start position:0% +squirly things squiggly things here are + + + align:start position:0% +squirly things squiggly things here are +alpha helices which is one type of a + + align:start position:0% +alpha helices which is one type of a + + + align:start position:0% +alpha helices which is one type of a +secondary structure and you'll learn + + align:start position:0% +secondary structure and you'll learn + + + align:start position:0% +secondary structure and you'll learn +about that in 507 or 705 and uh arrows + + align:start position:0% +about that in 507 or 705 and uh arrows + + + align:start position:0% +about that in 507 or 705 and uh arrows +are often indicated what's called beta + + align:start position:0% +are often indicated what's called beta + + + align:start position:0% +are often indicated what's called beta +sheets extended regions of the uh amino + + align:start position:0% +sheets extended regions of the uh amino + + + align:start position:0% +sheets extended regions of the uh amino +acids and so this kind of gives you a + + align:start position:0% +acids and so this kind of gives you a + + + align:start position:0% +acids and so this kind of gives you a +general sense of what we call the fold + + align:start position:0% +general sense of what we call the fold + + + align:start position:0% +general sense of what we call the fold +of the protein uh in these diagrams and + + align:start position:0% +of the protein uh in these diagrams and + + + align:start position:0% +of the protein uh in these diagrams and +so this gives you a sense of how big + + align:start position:0% +so this gives you a sense of how big + + + align:start position:0% +so this gives you a sense of how big +this molecule actually is and we report + + align:start position:0% +this molecule actually is and we report + + + align:start position:0% +this molecule actually is and we report +things in angstroms uh typically because + + align:start position:0% +things in angstroms uh typically because + + + align:start position:0% +things in angstroms uh typically because +that's a good a good unit of measure um + + align:start position:0% +that's a good a good unit of measure um + + + align:start position:0% +that's a good a good unit of measure um +that helps tell you about how far apart + + align:start position:0% +that helps tell you about how far apart + + + align:start position:0% +that helps tell you about how far apart +the atoms are in structures so what is + + align:start position:0% +the atoms are in structures so what is + + + align:start position:0% +the atoms are in structures so what is +this particular enzyme well this + + align:start position:0% +this particular enzyme well this + + + align:start position:0% +this particular enzyme well this +particular enzyme uh does uh is involved + + align:start position:0% +particular enzyme uh does uh is involved + + + align:start position:0% +particular enzyme uh does uh is involved +in catalyzing the last step in the + + align:start position:0% +in catalyzing the last step in the + + + align:start position:0% +in catalyzing the last step in the +biosynthesis of an antibiotic + + align:start position:0% +biosynthesis of an antibiotic + + + align:start position:0% +biosynthesis of an antibiotic +phosphomycin and so this is the uh + + align:start position:0% +phosphomycin and so this is the uh + + + align:start position:0% +phosphomycin and so this is the uh +reactant or uh substrate and this is the + + align:start position:0% +reactant or uh substrate and this is the + + + align:start position:0% +reactant or uh substrate and this is the +product + + align:start position:0% +product + + + align:start position:0% +product +phosphomycin so what phosphomycin does + + align:start position:0% +phosphomycin so what phosphomycin does + + + align:start position:0% +phosphomycin so what phosphomycin does +is it inhibits cell wall biosynthesis of + + align:start position:0% +is it inhibits cell wall biosynthesis of + + + align:start position:0% +is it inhibits cell wall biosynthesis of +bacteria and it forms a calent adduct + + align:start position:0% +bacteria and it forms a calent adduct + + + align:start position:0% +bacteria and it forms a calent adduct +with amino acid in the active site of uh + + align:start position:0% +with amino acid in the active site of uh + + + align:start position:0% +with amino acid in the active site of uh +one of the important enzymes in cell + + align:start position:0% +one of the important enzymes in cell + + + align:start position:0% +one of the important enzymes in cell +wall biosynthesis and so a lot of + + align:start position:0% +wall biosynthesis and so a lot of + + + align:start position:0% +wall biosynthesis and so a lot of +antibiotics Target cell wall + + align:start position:0% +antibiotics Target cell wall + + + align:start position:0% +antibiotics Target cell wall +biosynthesis so recently I mean it was + + align:start position:0% +biosynthesis so recently I mean it was + + + align:start position:0% +biosynthesis so recently I mean it was +first approved to treat um mostly like + + align:start position:0% +first approved to treat um mostly like + + + align:start position:0% +first approved to treat um mostly like +bladder infections and sort of more + + align:start position:0% +bladder infections and sort of more + + + align:start position:0% +bladder infections and sort of more +minor type of infections but recently + + align:start position:0% +minor type of infections but recently + + + align:start position:0% +minor type of infections but recently +they found that it works against um + + align:start position:0% +they found that it works against um + + + align:start position:0% +they found that it works against um +strains of of staff orus infection which + + align:start position:0% +strains of of staff orus infection which + + + align:start position:0% +strains of of staff orus infection which +is pretty serious um there's several + + align:start position:0% +is pretty serious um there's several + + + align:start position:0% +is pretty serious um there's several +strains of of staff infections now that + + align:start position:0% +strains of of staff infections now that + + + align:start position:0% +strains of of staff infections now that +are resistant to some of the powerful + + align:start position:0% +are resistant to some of the powerful + + + align:start position:0% +are resistant to some of the powerful +kinds of antibiotics that have been used + + align:start position:0% +kinds of antibiotics that have been used + + + align:start position:0% +kinds of antibiotics that have been used +before and so they're looking for new + + align:start position:0% +before and so they're looking for new + + + align:start position:0% +before and so they're looking for new +antibiotics that might that might be + + align:start position:0% +antibiotics that might that might be + + + align:start position:0% +antibiotics that might that might be +successful in treating those infections + + align:start position:0% +successful in treating those infections + + + align:start position:0% +successful in treating those infections +so antibiotic resistance of certain + + align:start position:0% +so antibiotic resistance of certain + + + align:start position:0% +so antibiotic resistance of certain +kinds of uh of uh bacteria has become + + align:start position:0% +kinds of uh of uh bacteria has become + + + align:start position:0% +kinds of uh of uh bacteria has become +really enormous problem and it's just + + align:start position:0% +really enormous problem and it's just + + + align:start position:0% +really enormous problem and it's just +getting worse I always like to ask a + + align:start position:0% +getting worse I always like to ask a + + + align:start position:0% +getting worse I always like to ask a +crowd like this um how many have taken + + align:start position:0% +crowd like this um how many have taken + + + align:start position:0% +crowd like this um how many have taken +antibiotics just zero times in their + + align:start position:0% +antibiotics just zero times in their + + + align:start position:0% +antibiotics just zero times in their +life first never taking + + align:start position:0% +life first never taking + + + align:start position:0% +life first never taking +antibiotics okay I don't see anybody how + + align:start position:0% +antibiotics okay I don't see anybody how + + + align:start position:0% +antibiotics okay I don't see anybody how +about + + align:start position:0% +about + + + align:start position:0% +about +once like three people + + align:start position:0% +once like three people + + + align:start position:0% +once like three people +twice a few more three times + + align:start position:0% +twice a few more three times + + + align:start position:0% +twice a few more three times +you probably don't remember uh say you + + align:start position:0% +you probably don't remember uh say you + + + align:start position:0% +you probably don't remember uh say you +know around maybe five or more or + + align:start position:0% +know around maybe five or more or + + + align:start position:0% +know around maybe five or more or +something like + + align:start position:0% +something like + + + align:start position:0% +something like +that okay so uh you can see from looking + + align:start position:0% +that okay so uh you can see from looking + + + align:start position:0% +that okay so uh you can see from looking +around why this is a problem so uh + + align:start position:0% +around why this is a problem so uh + + + align:start position:0% +around why this is a problem so uh +bacteria they're they're they're clever + + align:start position:0% +bacteria they're they're they're clever + + + align:start position:0% +bacteria they're they're they're clever +uh they figure out try to get around + + align:start position:0% +uh they figure out try to get around + + + align:start position:0% +uh they figure out try to get around +ways if they can they want to survive so + + align:start position:0% +ways if they can they want to survive so + + + align:start position:0% +ways if they can they want to survive so +there's some nice natural selection + + align:start position:0% +there's some nice natural selection + + + align:start position:0% +there's some nice natural selection +going on and they're actually resistant + + align:start position:0% +going on and they're actually resistant + + + align:start position:0% +going on and they're actually resistant +strains to phosph mey as well as well + + align:start position:0% +strains to phosph mey as well as well + + + align:start position:0% +strains to phosph mey as well as well +and what happens in that case is I said + + align:start position:0% +and what happens in that case is I said + + + align:start position:0% +and what happens in that case is I said +that it works by becoming attached to + + align:start position:0% +that it works by becoming attached to + + + align:start position:0% +that it works by becoming attached to +amino acid and then the enzyme is dead + + align:start position:0% +amino acid and then the enzyme is dead + + + align:start position:0% +amino acid and then the enzyme is dead +but if that amino acid is mutated it's a + + align:start position:0% +but if that amino acid is mutated it's a + + + align:start position:0% +but if that amino acid is mutated it's a +cysteine if it mutates to an aspartic + + align:start position:0% +cysteine if it mutates to an aspartic + + + align:start position:0% +cysteine if it mutates to an aspartic +acid then it can no longer be inhibited + + align:start position:0% +acid then it can no longer be inhibited + + + align:start position:0% +acid then it can no longer be inhibited +by this and it still works it's not as + + align:start position:0% +by this and it still works it's not as + + + align:start position:0% +by this and it still works it's not as +good an enzyme but it still works so if + + align:start position:0% +good an enzyme but it still works so if + + + align:start position:0% +good an enzyme but it still works so if +there's pressure applied natural + + align:start position:0% +there's pressure applied natural + + + align:start position:0% +there's pressure applied natural +selection die or mutate uh a lot of + + align:start position:0% +selection die or mutate uh a lot of + + + align:start position:0% +selection die or mutate uh a lot of +things will be very happy to mutate if + + align:start position:0% +things will be very happy to mutate if + + + align:start position:0% +things will be very happy to mutate if +they can and some of the antibiotics if + + align:start position:0% +they can and some of the antibiotics if + + + align:start position:0% +they can and some of the antibiotics if +it mutates it only just one amino acid + + align:start position:0% +it mutates it only just one amino acid + + + align:start position:0% +it mutates it only just one amino acid +changes all of a sudden uh there's a + + align:start position:0% +changes all of a sudden uh there's a + + + align:start position:0% +changes all of a sudden uh there's a +resistance going on so the more times + + align:start position:0% +resistance going on so the more times + + + align:start position:0% +resistance going on so the more times +that uh bacteria are exposed to + + align:start position:0% +that uh bacteria are exposed to + + + align:start position:0% +that uh bacteria are exposed to +antibiotics the more likely it is + + align:start position:0% +antibiotics the more likely it is + + + align:start position:0% +antibiotics the more likely it is +they'll mutate in such a way that uh + + align:start position:0% +they'll mutate in such a way that uh + + + align:start position:0% +they'll mutate in such a way that uh +they'll be resistant in the future so + + align:start position:0% +they'll be resistant in the future so + + + align:start position:0% +they'll be resistant in the future so +this is a really huge problem so if + + align:start position:0% +this is a really huge problem so if + + + align:start position:0% +this is a really huge problem so if +you're thinking about you know you're + + align:start position:0% +you're thinking about you know you're + + + align:start position:0% +you're thinking about you know you're +interested in science what should I do + + align:start position:0% +interested in science what should I do + + + align:start position:0% +interested in science what should I do +with my life this is uh one one thing + + align:start position:0% +with my life this is uh one one thing + + + align:start position:0% +with my life this is uh one one thing +that uh you might want to think about a + + align:start position:0% +that uh you might want to think about a + + + align:start position:0% +that uh you might want to think about a +lot of what we take antibiotics for used + + align:start position:0% +lot of what we take antibiotics for used + + + align:start position:0% +lot of what we take antibiotics for used +to be conditions that um were deadly so + + align:start position:0% +to be conditions that um were deadly so + + + align:start position:0% +to be conditions that um were deadly so +if we don't have antibiotics then um + + align:start position:0% +if we don't have antibiotics then um + + + align:start position:0% +if we don't have antibiotics then um +life expectancy is quite a bit different + + align:start position:0% +life expectancy is quite a bit different + + + align:start position:0% +life expectancy is quite a bit different +anyway so this is one of the projects in + + align:start position:0% +anyway so this is one of the projects in + + + align:start position:0% +anyway so this is one of the projects in +my lab we're looking at a number of uh + + align:start position:0% +my lab we're looking at a number of uh + + + align:start position:0% +my lab we're looking at a number of uh +different enzymes that are involved in + + align:start position:0% +different enzymes that are involved in + + + align:start position:0% +different enzymes that are involved in +antibiotic + + align:start position:0% +antibiotic + + + align:start position:0% +antibiotic +biosynthesis all right so enzyme + + align:start position:0% + + + + align:start position:0% + +catalysis so uh we're gonna I'm going to + + align:start position:0% +catalysis so uh we're gonna I'm going to + + + align:start position:0% +catalysis so uh we're gonna I'm going to +introduce you to a few terms and then + + align:start position:0% +introduce you to a few terms and then + + + align:start position:0% +introduce you to a few terms and then +what we're going to do is we're going to + + align:start position:0% +what we're going to do is we're going to + + + align:start position:0% +what we're going to do is we're going to +use the things that you learned mostly + + align:start position:0% +use the things that you learned mostly + + + align:start position:0% +use the things that you learned mostly +last Wednesday on mechanism of reactions + + align:start position:0% +last Wednesday on mechanism of reactions + + + align:start position:0% +last Wednesday on mechanism of reactions +and we're going to derive uh the michaus + + align:start position:0% +and we're going to derive uh the michaus + + + align:start position:0% +and we're going to derive uh the michaus +Menan equations for enzyme kinetics so + + align:start position:0% +Menan equations for enzyme kinetics so + + + align:start position:0% +Menan equations for enzyme kinetics so +you didn't you might not have realized + + align:start position:0% +you didn't you might not have realized + + + align:start position:0% +you didn't you might not have realized +that on Wednesday you were learning all + + align:start position:0% +that on Wednesday you were learning all + + + align:start position:0% +that on Wednesday you were learning all +the sort of tools you need in + + align:start position:0% +the sort of tools you need in + + + align:start position:0% +the sort of tools you need in +Biochemistry you were actually learning + + align:start position:0% +Biochemistry you were actually learning + + + align:start position:0% +Biochemistry you were actually learning +biochemistry but you were and I think + + align:start position:0% +biochemistry but you were and I think + + + align:start position:0% +biochemistry but you were and I think +you'll see that uh see that now so first + + align:start position:0% +you'll see that uh see that now so first + + + align:start position:0% +you'll see that uh see that now so first +a couple of new terms I already + + align:start position:0% +a couple of new terms I already + + + align:start position:0% +a couple of new terms I already +introduced this a little bit but + + align:start position:0% +introduced this a little bit but + + + align:start position:0% +introduced this a little bit but +reactant molecules we're always talking + + align:start position:0% +reactant molecules we're always talking + + + align:start position:0% +reactant molecules we're always talking +about reactants when you're talking + + align:start position:0% +about reactants when you're talking + + + align:start position:0% +about reactants when you're talking +about enzymes you're talking about + + align:start position:0% +about enzymes you're talking about + + + align:start position:0% +about enzymes you're talking about +substrates so we no longer call them + + align:start position:0% +substrates so we no longer call them + + + align:start position:0% +substrates so we no longer call them +reactants We Now call them + + align:start position:0% +reactants We Now call them + + + align:start position:0% +reactants We Now call them +substrates and substrates bind to what's + + align:start position:0% +substrates and substrates bind to what's + + + align:start position:0% +substrates and substrates bind to what's +known as the active site of the enzyme + + align:start position:0% +known as the active site of the enzyme + + + align:start position:0% +known as the active site of the enzyme +uh that's the site where catalysis + + align:start position:0% +uh that's the site where catalysis + + + align:start position:0% +uh that's the site where catalysis +occurs so it's active and that's pretty + + align:start position:0% +occurs so it's active and that's pretty + + + align:start position:0% +occurs so it's active and that's pretty +easy to + + align:start position:0% +easy to + + + align:start position:0% +easy to +remember so here is a very very simple + + align:start position:0% +remember so here is a very very simple + + + align:start position:0% +remember so here is a very very simple +enzyme reaction and a lot of enzyme + + align:start position:0% +enzyme reaction and a lot of enzyme + + + align:start position:0% +enzyme reaction and a lot of enzyme +reactions actually are fairly simple so + + align:start position:0% +reactions actually are fairly simple so + + + align:start position:0% +reactions actually are fairly simple so +here uh you'd have an enzyme binding to + + align:start position:0% +here uh you'd have an enzyme binding to + + + align:start position:0% +here uh you'd have an enzyme binding to +your substrate enzyme called e substrate + + align:start position:0% +your substrate enzyme called e substrate + + + align:start position:0% +your substrate enzyme called e substrate +called s when the substrate binds to the + + align:start position:0% +called s when the substrate binds to the + + + align:start position:0% +called s when the substrate binds to the +enzyme it forms an enzyme substrate + + align:start position:0% +enzyme it forms an enzyme substrate + + + align:start position:0% +enzyme it forms an enzyme substrate +complex which is known as an es + + align:start position:0% +complex which is known as an es + + + align:start position:0% +complex which is known as an es +complex that enzyme substrate complex or + + align:start position:0% +complex that enzyme substrate complex or + + + align:start position:0% +complex that enzyme substrate complex or +ES complex will go on and form enzyme e + + align:start position:0% +ES complex will go on and form enzyme e + + + align:start position:0% +ES complex will go on and form enzyme e +and product + + align:start position:0% + + + + align:start position:0% + +P so just to show that in cartoon form + + align:start position:0% +P so just to show that in cartoon form + + + align:start position:0% +P so just to show that in cartoon form +and it pains me to do this to draw the + + align:start position:0% +and it pains me to do this to draw the + + + align:start position:0% +and it pains me to do this to draw the +enzyme like this because as you saw in + + align:start position:0% +enzyme like this because as you saw in + + + align:start position:0% +enzyme like this because as you saw in +the last slide enzymes are really quite + + align:start position:0% +the last slide enzymes are really quite + + + align:start position:0% +the last slide enzymes are really quite +beautiful and uh this is a very sad uh + + align:start position:0% +beautiful and uh this is a very sad uh + + + align:start position:0% +beautiful and uh this is a very sad uh +description of what an enzyme looks like + + align:start position:0% +description of what an enzyme looks like + + + align:start position:0% +description of what an enzyme looks like +and also here are the substrates about + + align:start position:0% +and also here are the substrates about + + + align:start position:0% +and also here are the substrates about +the size of the enzyme which is also all + + align:start position:0% +the size of the enzyme which is also all + + + align:start position:0% +the size of the enzyme which is also all +uh off but uh here is the substrate + + align:start position:0% +uh off but uh here is the substrate + + + align:start position:0% +uh off but uh here is the substrate +binding to the enzy this would be the + + align:start position:0% +binding to the enzy this would be the + + + align:start position:0% +binding to the enzy this would be the +active site and uh would be designed + + align:start position:0% +active site and uh would be designed + + + align:start position:0% +active site and uh would be designed +just to uh fit the substrate in there + + align:start position:0% +just to uh fit the substrate in there + + + align:start position:0% +just to uh fit the substrate in there +quite + + align:start position:0% +quite + + + align:start position:0% +quite +nicely when substrate binds to the + + align:start position:0% +nicely when substrate binds to the + + + align:start position:0% +nicely when substrate binds to the +enzyme you form what's known as the es + + align:start position:0% +enzyme you form what's known as the es + + + align:start position:0% +enzyme you form what's known as the es +complex and usually this binding is + + align:start position:0% +complex and usually this binding is + + + align:start position:0% +complex and usually this binding is +reversible so uh not all substrate that + + align:start position:0% +reversible so uh not all substrate that + + + align:start position:0% +reversible so uh not all substrate that +binds to the enzyme will go on to form + + align:start position:0% +binds to the enzyme will go on to form + + + align:start position:0% +binds to the enzyme will go on to form +product some will go back and form free + + align:start position:0% +product some will go back and form free + + + align:start position:0% +product some will go back and form free +substrate and + + align:start position:0% +substrate and + + + align:start position:0% +substrate and +enzyme and in this uh drawing then when + + align:start position:0% +enzyme and in this uh drawing then when + + + align:start position:0% +enzyme and in this uh drawing then when +the enzyme reacts on the substrate it'll + + align:start position:0% +the enzyme reacts on the substrate it'll + + + align:start position:0% +the enzyme reacts on the substrate it'll +form product and free enzyme again and + + align:start position:0% +form product and free enzyme again and + + + align:start position:0% +form product and free enzyme again and +this is drawn with a single line uh as + + align:start position:0% +this is drawn with a single line uh as + + + align:start position:0% +this is drawn with a single line uh as +not being a a reversible uh step in the + + align:start position:0% +not being a a reversible uh step in the + + + align:start position:0% +not being a a reversible uh step in the +reaction so here you see substrate and + + align:start position:0% +reaction so here you see substrate and + + + align:start position:0% +reaction so here you see substrate and +what the enzyme this enzyme did is sort + + align:start position:0% +what the enzyme this enzyme did is sort + + + align:start position:0% +what the enzyme this enzyme did is sort +of make the substrate look a little more + + align:start position:0% +of make the substrate look a little more + + + align:start position:0% +of make the substrate look a little more +like a Mickey Mouse so there's our + + align:start position:0% +like a Mickey Mouse so there's our + + + align:start position:0% +like a Mickey Mouse so there's our +product coming + + align:start position:0% + + + + align:start position:0% + +off so now we can + + align:start position:0% +off so now we can + + + align:start position:0% +off so now we can +drive uh we can drive equations to + + align:start position:0% +drive uh we can drive equations to + + + align:start position:0% +drive uh we can drive equations to +represent that reaction that I just + + align:start position:0% +represent that reaction that I just + + + align:start position:0% +represent that reaction that I just +showed you and we can use all the same + + align:start position:0% +showed you and we can use all the same + + + align:start position:0% +showed you and we can use all the same +ideas that we had when we were driving + + align:start position:0% +ideas that we had when we were driving + + + align:start position:0% +ideas that we had when we were driving +mechanisms in class last Wednesday and + + align:start position:0% +mechanisms in class last Wednesday and + + + align:start position:0% +mechanisms in class last Wednesday and +on problem set + + align:start position:0% +on problem set + + + align:start position:0% +on problem set +10 so again the reaction is enzyme plus + + align:start position:0% +10 so again the reaction is enzyme plus + + + align:start position:0% +10 so again the reaction is enzyme plus +substrate e plus s going in a reversible + + align:start position:0% +substrate e plus s going in a reversible + + + align:start position:0% +substrate e plus s going in a reversible +step to uh the enzyme strstr complex es + + align:start position:0% +step to uh the enzyme strstr complex es + + + align:start position:0% +step to uh the enzyme strstr complex es +and then going with a single uh + + align:start position:0% +and then going with a single uh + + + align:start position:0% +and then going with a single uh +non-reversible step to enzyme and + + align:start position:0% +non-reversible step to enzyme and + + + align:start position:0% +non-reversible step to enzyme and +product so we can put this in Two Steps + + align:start position:0% +product so we can put this in Two Steps + + + align:start position:0% +product so we can put this in Two Steps +step one uh is the reversible step of + + align:start position:0% +step one uh is the reversible step of + + + align:start position:0% +step one uh is the reversible step of +enzyme and substrate going to the enzyme + + align:start position:0% +enzyme and substrate going to the enzyme + + + align:start position:0% +enzyme and substrate going to the enzyme +substrate complex with Ray constants K1 + + align:start position:0% +substrate complex with Ray constants K1 + + + align:start position:0% +substrate complex with Ray constants K1 +for forward step and K minus one for the + + align:start position:0% +for forward step and K minus one for the + + + align:start position:0% +for forward step and K minus one for the +reverse step in step two we have the + + align:start position:0% +reverse step in step two we have the + + + align:start position:0% +reverse step in step two we have the +enzyme substrate complex going to enzyme + + align:start position:0% +enzyme substrate complex going to enzyme + + + align:start position:0% +enzyme substrate complex going to enzyme +and product with rate constant K2 so + + align:start position:0% +and product with rate constant K2 so + + + align:start position:0% +and product with rate constant K2 so +these then are Elementary reactions and + + align:start position:0% +these then are Elementary reactions and + + + align:start position:0% +these then are Elementary reactions and +so we can write the rate law for each + + align:start position:0% +so we can write the rate law for each + + + align:start position:0% +so we can write the rate law for each +step uh just based as how the reaction + + align:start position:0% +step uh just based as how the reaction + + + align:start position:0% +step uh just based as how the reaction +is written so what would be the uh rate + + align:start position:0% +is written so what would be the uh rate + + + align:start position:0% +is written so what would be the uh rate +for the forward + + align:start position:0% + + + + align:start position:0% + +reaction K1 + + align:start position:0% +reaction K1 + + + align:start position:0% +reaction K1 +* e * + + align:start position:0% +* e * + + + align:start position:0% +* e * +s all right so there's the rate for the + + align:start position:0% +s all right so there's the rate for the + + + align:start position:0% +s all right so there's the rate for the +forward reaction again just based on + + align:start position:0% +forward reaction again just based on + + + align:start position:0% +forward reaction again just based on +rate constant times the two things that + + align:start position:0% +rate constant times the two things that + + + align:start position:0% +rate constant times the two things that +are reacting what about for the reverse + + align:start position:0% +are reacting what about for the reverse + + + align:start position:0% +are reacting what about for the reverse +reaction + + align:start position:0% + + + + align:start position:0% + +so we + + align:start position:0% +so we + + + align:start position:0% +so we +have what's the rate + + align:start position:0% +have what's the rate + + + align:start position:0% +have what's the rate +constant K minus1 time es right so that + + align:start position:0% +constant K minus1 time es right so that + + + align:start position:0% +constant K minus1 time es right so that +would be for the reverse reaction and + + align:start position:0% +would be for the reverse reaction and + + + align:start position:0% +would be for the reverse reaction and +what about the rate for step + + align:start position:0% +what about the rate for step + + + align:start position:0% +what about the rate for step +two K2 + + align:start position:0% +two K2 + + + align:start position:0% +two K2 +times times es right okay so now we can + + align:start position:0% +times times es right okay so now we can + + + align:start position:0% +times times es right okay so now we can +look at the rate of formation of product + + align:start position:0% +look at the rate of formation of product + + + align:start position:0% +look at the rate of formation of product +the overall reaction so the rate of + + align:start position:0% +the overall reaction so the rate of + + + align:start position:0% +the overall reaction so the rate of +product formation + + align:start position:0% +product formation + + + align:start position:0% +product formation +can be expressed as the uh change DP DT + + align:start position:0% +can be expressed as the uh change DP DT + + + align:start position:0% +can be expressed as the uh change DP DT +with time uh for product and also we can + + align:start position:0% +with time uh for product and also we can + + + align:start position:0% +with time uh for product and also we can +just write it from the from the second + + align:start position:0% +just write it from the from the second + + + align:start position:0% +just write it from the from the second +step in terms of K2 times es s so that's + + align:start position:0% +step in terms of K2 times es s so that's + + + align:start position:0% +step in terms of K2 times es s so that's +the rate of formation of + + align:start position:0% +the rate of formation of + + + align:start position:0% +the rate of formation of +product are we + + align:start position:0% +product are we + + + align:start position:0% +product are we +done no because + + align:start position:0% +done no because + + + align:start position:0% +done no because +why there's an + + align:start position:0% +why there's an + + + align:start position:0% +why there's an +intermediate so we have to solve for the + + align:start position:0% +intermediate so we have to solve for the + + + align:start position:0% +intermediate so we have to solve for the +intermediate again this should seem + + align:start position:0% +intermediate again this should seem + + + align:start position:0% +intermediate again this should seem +familiar it's all the same stuff we were + + align:start position:0% +familiar it's all the same stuff we were + + + align:start position:0% +familiar it's all the same stuff we were +talking about last + + align:start position:0% +talking about last + + + align:start position:0% +talking about last +week so we need to solve for the + + align:start position:0% +week so we need to solve for the + + + align:start position:0% +week so we need to solve for the +intermediate we're not given anything + + align:start position:0% +intermediate we're not given anything + + + align:start position:0% +intermediate we're not given anything +about fast and slow steps so we're going + + align:start position:0% +about fast and slow steps so we're going + + + align:start position:0% +about fast and slow steps so we're going +to use the steady state + + align:start position:0% +to use the steady state + + + align:start position:0% +to use the steady state +approximation uh which is going to tell + + align:start position:0% +approximation uh which is going to tell + + + align:start position:0% +approximation uh which is going to tell +you that the net formation of + + align:start position:0% +you that the net formation of + + + align:start position:0% +you that the net formation of +intermediates is pretty much constant + + align:start position:0% +intermediates is pretty much constant + + + align:start position:0% +intermediates is pretty much constant +it's in the steady state another way to + + align:start position:0% +it's in the steady state another way to + + + align:start position:0% +it's in the steady state another way to +express that is that the uh all the + + align:start position:0% +express that is that the uh all the + + + align:start position:0% +express that is that the uh all the +steps that form uh the intermediate are + + align:start position:0% +steps that form uh the intermediate are + + + align:start position:0% +steps that form uh the intermediate are +equal in rate to all the steps that get + + align:start position:0% +equal in rate to all the steps that get + + + align:start position:0% +equal in rate to all the steps that get +rid of that intermediate either consume + + align:start position:0% +rid of that intermediate either consume + + + align:start position:0% +rid of that intermediate either consume +it or decompose it so first we need to + + align:start position:0% +it or decompose it so first we need to + + + align:start position:0% +it or decompose it so first we need to +uh look at what all the steps are that + + align:start position:0% +uh look at what all the steps are that + + + align:start position:0% +uh look at what all the steps are that +have to do with the + + align:start position:0% +have to do with the + + + align:start position:0% +have to do with the +intermediate so here is the uh rate of + + align:start position:0% +intermediate so here is the uh rate of + + + align:start position:0% +intermediate so here is the uh rate of +uh the formation of that intermediate + + align:start position:0% +uh the formation of that intermediate + + + align:start position:0% +uh the formation of that intermediate +and so that's going to be equal to the + + align:start position:0% +and so that's going to be equal to the + + + align:start position:0% +and so that's going to be equal to the +steps involved in forming the + + align:start position:0% +steps involved in forming the + + + align:start position:0% +steps involved in forming the +intermediate and it's only formed in + + align:start position:0% +intermediate and it's only formed in + + + align:start position:0% +intermediate and it's only formed in +that first step for direction of the + + align:start position:0% +that first step for direction of the + + + align:start position:0% +that first step for direction of the +first step + + align:start position:0% +first step + + + align:start position:0% +first step +so it's rate K1 time the concentration + + align:start position:0% +so it's rate K1 time the concentration + + + align:start position:0% +so it's rate K1 time the concentration +of etimes the concentration of s so + + align:start position:0% +of etimes the concentration of s so + + + align:start position:0% +of etimes the concentration of s so +that's the rate of + + align:start position:0% +that's the rate of + + + align:start position:0% +that's the rate of +formation and then we're going to + + align:start position:0% +formation and then we're going to + + + align:start position:0% +formation and then we're going to +subtract from that steps that are + + align:start position:0% +subtract from that steps that are + + + align:start position:0% +subtract from that steps that are +involved in the decomposition or in the + + align:start position:0% +involved in the decomposition or in the + + + align:start position:0% +involved in the decomposition or in the +consumption of the intermediate the + + align:start position:0% +consumption of the intermediate the + + + align:start position:0% +consumption of the intermediate the +intermediate decomposes in the reverse + + align:start position:0% +intermediate decomposes in the reverse + + + align:start position:0% +intermediate decomposes in the reverse +direction of step one so that's this + + align:start position:0% +direction of step one so that's this + + + align:start position:0% +direction of step one so that's this +rate K minus1 * e s + + align:start position:0% +rate K minus1 * e s + + + align:start position:0% +rate K minus1 * e s +and it's also consumed in this second + + align:start position:0% +and it's also consumed in this second + + + align:start position:0% +and it's also consumed in this second +step so it's consumed um by the rate K2 + + align:start position:0% +step so it's consumed um by the rate K2 + + + align:start position:0% +step so it's consumed um by the rate K2 +times es again this is exactly the same + + align:start position:0% +times es again this is exactly the same + + + align:start position:0% +times es again this is exactly the same +as what we looked at last week and now + + align:start position:0% +as what we looked at last week and now + + + align:start position:0% +as what we looked at last week and now +we can consider the steady state + + align:start position:0% +we can consider the steady state + + + align:start position:0% +we can consider the steady state +approximation and we can set that whole + + align:start position:0% +approximation and we can set that whole + + + align:start position:0% +approximation and we can set that whole +term equal to zero so steady state again + + align:start position:0% +term equal to zero so steady state again + + + align:start position:0% +term equal to zero so steady state again +the net rate of formation of the + + align:start position:0% +the net rate of formation of the + + + align:start position:0% +the net rate of formation of the +intermediate is equal to the net rate at + + align:start position:0% +intermediate is equal to the net rate at + + + align:start position:0% +intermediate is equal to the net rate at +which it goes away so so so it's it's uh + + align:start position:0% +which it goes away so so so it's it's uh + + + align:start position:0% +which it goes away so so so it's it's uh +the whole equation can be set equal to + + align:start position:0% +the whole equation can be set equal to + + + align:start position:0% +the whole equation can be set equal to +zero so we can do that here set this + + align:start position:0% +zero so we can do that here set this + + + align:start position:0% +zero so we can do that here set this +term equal to + + align:start position:0% + + + + align:start position:0% + +zero now there's a slight change so it's + + align:start position:0% +zero now there's a slight change so it's + + + align:start position:0% +zero now there's a slight change so it's +not 100% what we did before uh there is + + align:start position:0% +not 100% what we did before uh there is + + + align:start position:0% +not 100% what we did before uh there is +a slight change and that comes out of a + + align:start position:0% +a slight change and that comes out of a + + + align:start position:0% +a slight change and that comes out of a +practical + + align:start position:0% +practical + + + align:start position:0% +practical +consideration so when you're doing these + + align:start position:0% +consideration so when you're doing these + + + align:start position:0% +consideration so when you're doing these +experiments in the term that we had you + + align:start position:0% +experiments in the term that we had you + + + align:start position:0% +experiments in the term that we had you +usually don't know how much enzyme is + + align:start position:0% +usually don't know how much enzyme is + + + align:start position:0% +usually don't know how much enzyme is +free and it's hard to figure that out at + + align:start position:0% +free and it's hard to figure that out at + + + align:start position:0% +free and it's hard to figure that out at +any one time how much enzyme is not + + align:start position:0% +any one time how much enzyme is not + + + align:start position:0% +any one time how much enzyme is not +reacting with the substrate it's much + + align:start position:0% +reacting with the substrate it's much + + + align:start position:0% +reacting with the substrate it's much +easier to know how much enzyme you added + + align:start position:0% +easier to know how much enzyme you added + + + align:start position:0% +easier to know how much enzyme you added +to the reaction to begin with that's a + + align:start position:0% +to the reaction to begin with that's a + + + align:start position:0% +to the reaction to begin with that's a +number that you should know you should + + align:start position:0% +number that you should know you should + + + align:start position:0% +number that you should know you should +have carefully figured out how much + + align:start position:0% +have carefully figured out how much + + + align:start position:0% +have carefully figured out how much +enzyme that you were going to use in + + align:start position:0% +enzyme that you were going to use in + + + align:start position:0% +enzyme that you were going to use in +your + + align:start position:0% +your + + + align:start position:0% +your +experiment so instead of solving for the + + align:start position:0% +experiment so instead of solving for the + + + align:start position:0% +experiment so instead of solving for the +intermediate in terms of the free enzyme + + align:start position:0% +intermediate in terms of the free enzyme + + + align:start position:0% +intermediate in terms of the free enzyme +it's easier to solve for it in terms of + + align:start position:0% +it's easier to solve for it in terms of + + + align:start position:0% +it's easier to solve for it in terms of +um the total enzyme which we're going to + + align:start position:0% +um the total enzyme which we're going to + + + align:start position:0% +um the total enzyme which we're going to +call E not how much enzyme you put into + + align:start position:0% +call E not how much enzyme you put into + + + align:start position:0% +call E not how much enzyme you put into +the equation so the total enzyme that's + + align:start position:0% +the equation so the total enzyme that's + + + align:start position:0% +the equation so the total enzyme that's +going that's that's reacting with + + align:start position:0% +going that's that's reacting with + + + align:start position:0% +going that's that's reacting with +substrate uh that you put into the + + align:start position:0% +substrate uh that you put into the + + + align:start position:0% +substrate uh that you put into the +experiment would equal the amount that's + + align:start position:0% +experiment would equal the amount that's + + + align:start position:0% +experiment would equal the amount that's +free the amount that's not reacting at + + align:start position:0% +free the amount that's not reacting at + + + align:start position:0% +free the amount that's not reacting at +any given time or that just finished + + align:start position:0% +any given time or that just finished + + + align:start position:0% +any given time or that just finished +reacting and the amount of the enzyme + + align:start position:0% +reacting and the amount of the enzyme + + + align:start position:0% +reacting and the amount of the enzyme +that's bound it's only going to be free + + align:start position:0% +that's bound it's only going to be free + + + align:start position:0% +that's bound it's only going to be free +or bound so the total enzyme equals + + align:start position:0% +or bound so the total enzyme equals + + + align:start position:0% +or bound so the total enzyme equals +these two + + align:start position:0% +these two + + + align:start position:0% +these two +and so you can go back to your other + + align:start position:0% +and so you can go back to your other + + + align:start position:0% +and so you can go back to your other +equation right now and wherever you had + + align:start position:0% +equation right now and wherever you had + + + align:start position:0% +equation right now and wherever you had +free enzyme you can substitute in terms + + align:start position:0% +free enzyme you can substitute in terms + + + align:start position:0% +free enzyme you can substitute in terms +for total enzyme minus bound because + + align:start position:0% +for total enzyme minus bound because + + + align:start position:0% +for total enzyme minus bound because +that's going to be equal to free and + + align:start position:0% +that's going to be equal to free and + + + align:start position:0% +that's going to be equal to free and +again this is just a practical + + align:start position:0% +again this is just a practical + + + align:start position:0% +again this is just a practical +consideration that it's easier if you're + + align:start position:0% +consideration that it's easier if you're + + + align:start position:0% +consideration that it's easier if you're +doing these experiments and again + + align:start position:0% +doing these experiments and again + + + align:start position:0% +doing these experiments and again +biochemistry is and experimental science + + align:start position:0% +biochemistry is and experimental science + + + align:start position:0% +biochemistry is and experimental science +to know how much enzyme you started with + + align:start position:0% +to know how much enzyme you started with + + + align:start position:0% +to know how much enzyme you started with +than to know how much is non-reacting at + + align:start position:0% +than to know how much is non-reacting at + + + align:start position:0% +than to know how much is non-reacting at +any given time so this is just a + + align:start position:0% +any given time so this is just a + + + align:start position:0% +any given time so this is just a +practical thing and for all the other + + align:start position:0% +practical thing and for all the other + + + align:start position:0% +practical thing and for all the other +things we worked on you're always + + align:start position:0% +things we worked on you're always + + + align:start position:0% +things we worked on you're always +wanting to solve for the intermediate + + align:start position:0% +wanting to solve for the intermediate + + + align:start position:0% +wanting to solve for the intermediate +and things in terms of things you could + + align:start position:0% +and things in terms of things you could + + + align:start position:0% +and things in terms of things you could +measure like rate constants and + + align:start position:0% +measure like rate constants and + + + align:start position:0% +measure like rate constants and +concentration of reactants or products + + align:start position:0% +concentration of reactants or products + + + align:start position:0% +concentration of reactants or products +it's a similar kind of idea you want to + + align:start position:0% +it's a similar kind of idea you want to + + + align:start position:0% +it's a similar kind of idea you want to +be able to solve for things in terms of + + align:start position:0% +be able to solve for things in terms of + + + align:start position:0% +be able to solve for things in terms of +stuff that you can actually + + align:start position:0% +stuff that you can actually + + + align:start position:0% +stuff that you can actually +measure so now we can go back again we + + align:start position:0% +measure so now we can go back again we + + + align:start position:0% +measure so now we can go back again we +had this is the equation that we were + + align:start position:0% +had this is the equation that we were + + + align:start position:0% +had this is the equation that we were +solving for our intermediate if you use + + align:start position:0% +solving for our intermediate if you use + + + align:start position:0% +solving for our intermediate if you use +a steady state approximation you set the + + align:start position:0% +a steady state approximation you set the + + + align:start position:0% +a steady state approximation you set the +whole term equal to zero and now we can + + align:start position:0% +whole term equal to zero and now we can + + + align:start position:0% +whole term equal to zero and now we can +take this term and substitute so we're + + align:start position:0% +take this term and substitute so we're + + + align:start position:0% +take this term and substitute so we're +going to replace this e and that's the + + align:start position:0% +going to replace this e and that's the + + + align:start position:0% +going to replace this e and that's the +only free enzyme that we had in in in + + align:start position:0% +only free enzyme that we had in in in + + + align:start position:0% +only free enzyme that we had in in in +this whole expression so we're going to + + align:start position:0% +this whole expression so we're going to + + + align:start position:0% +this whole expression so we're going to +replace this now with total enzyme minus + + align:start position:0% +replace this now with total enzyme minus + + + align:start position:0% +replace this now with total enzyme minus +the bound enzyme so we're going to put + + align:start position:0% +the bound enzyme so we're going to put + + + align:start position:0% +the bound enzyme so we're going to put +that term in here and that gives us the + + align:start position:0% +that term in here and that gives us the + + + align:start position:0% +that term in here and that gives us the +following so now we have k1s times in + + align:start position:0% +following so now we have k1s times in + + + align:start position:0% +following so now we have k1s times in +parentheses this term which equals free + + align:start position:0% +parentheses this term which equals free + + + align:start position:0% +parentheses this term which equals free +enzyme total minus bound and now now we + + align:start position:0% +enzyme total minus bound and now now we + + + align:start position:0% +enzyme total minus bound and now now we +can multiply that out so K1 s times a + + align:start position:0% +can multiply that out so K1 s times a + + + align:start position:0% +can multiply that out so K1 s times a +total enzyme here and then there's a + + align:start position:0% +total enzyme here and then there's a + + + align:start position:0% +total enzyme here and then there's a +minus here so uh we have K1 es uh times + + align:start position:0% +minus here so uh we have K1 es uh times + + + align:start position:0% +minus here so uh we have K1 es uh times +substrate over here and these parts are + + align:start position:0% +substrate over here and these parts are + + + align:start position:0% +substrate over here and these parts are +are + + align:start position:0% + + + + align:start position:0% + +unchanged so now we can uh solve for + + align:start position:0% +unchanged so now we can uh solve for + + + align:start position:0% +unchanged so now we can uh solve for +ES so here is our expression from the + + align:start position:0% +ES so here is our expression from the + + + align:start position:0% +ES so here is our expression from the +last sheet and now we can rearrange to + + align:start position:0% +last sheet and now we can rearrange to + + + align:start position:0% +last sheet and now we can rearrange to +solve for ES + + align:start position:0% + + + + align:start position:0% + +so we're going to put all the es terms + + align:start position:0% +so we're going to put all the es terms + + + align:start position:0% +so we're going to put all the es terms +onto one side so here's an es term here + + align:start position:0% +onto one side so here's an es term here + + + align:start position:0% +onto one side so here's an es term here +was an es term here was an es term so we + + align:start position:0% +was an es term here was an es term so we + + + align:start position:0% +was an es term here was an es term so we +moved those down to the other side of + + align:start position:0% +moved those down to the other side of + + + align:start position:0% +moved those down to the other side of +the equation gets rid of the negative + + align:start position:0% +the equation gets rid of the negative + + + align:start position:0% +the equation gets rid of the negative +bring that over bring that over and the + + align:start position:0% +bring that over bring that over and the + + + align:start position:0% +bring that over bring that over and the +only thing on the other side of the + + align:start position:0% +only thing on the other side of the + + + align:start position:0% +only thing on the other side of the +equation is this term here K1 * total + + align:start position:0% +equation is this term here K1 * total + + + align:start position:0% +equation is this term here K1 * total +enzyme time substrate now we can go + + align:start position:0% +enzyme time substrate now we can go + + + align:start position:0% +enzyme time substrate now we can go +ahead and as we did before pull out all + + align:start position:0% +ahead and as we did before pull out all + + + align:start position:0% +ahead and as we did before pull out all +of these es terms and come up with an + + align:start position:0% +of these es terms and come up with an + + + align:start position:0% +of these es terms and come up with an +expression that solves for it so we're + + align:start position:0% +expression that solves for it so we're + + + align:start position:0% +expression that solves for it so we're +going to solve for + + align:start position:0% +going to solve for + + + align:start position:0% +going to solve for +ES so we've pulled out es here we have + + align:start position:0% +ES so we've pulled out es here we have + + + align:start position:0% +ES so we've pulled out es here we have +k1s we have K2 K minus one and we have + + align:start position:0% +k1s we have K2 K minus one and we have + + + align:start position:0% +k1s we have K2 K minus one and we have +K2 and we have this expression over here + + align:start position:0% +K2 and we have this expression over here + + + align:start position:0% +K2 and we have this expression over here +and now we can take this expression and + + align:start position:0% +and now we can take this expression and + + + align:start position:0% +and now we can take this expression and +divide by that + + align:start position:0% +divide by that + + + align:start position:0% +divide by that +term and so this gives us an expression + + align:start position:0% +term and so this gives us an expression + + + align:start position:0% +term and so this gives us an expression +then for the concentration of our + + align:start position:0% +then for the concentration of our + + + align:start position:0% +then for the concentration of our +intermediate and now we're going to do + + align:start position:0% +intermediate and now we're going to do + + + align:start position:0% +intermediate and now we're going to do +one other thing that's a bit different + + align:start position:0% +one other thing that's a bit different + + + align:start position:0% +one other thing that's a bit different +this term has a lot of ks in it and so + + align:start position:0% +this term has a lot of ks in it and so + + + align:start position:0% +this term has a lot of ks in it and so +we're going to uh substitute these KS + + align:start position:0% +we're going to uh substitute these KS + + + align:start position:0% +we're going to uh substitute these KS +for another term that is more convenient + + align:start position:0% +for another term that is more convenient + + + align:start position:0% +for another term that is more convenient +to measure than any of these are by + + align:start position:0% +to measure than any of these are by + + + align:start position:0% +to measure than any of these are by +themselves so again this is a practical + + align:start position:0% +themselves so again this is a practical + + + align:start position:0% +themselves so again this is a practical +consideration you want to be able to use + + align:start position:0% +consideration you want to be able to use + + + align:start position:0% +consideration you want to be able to use +these equations to get information about + + align:start position:0% +these equations to get information about + + + align:start position:0% +these equations to get information about +enzyme + + align:start position:0% +enzyme + + + align:start position:0% +enzyme +kinetics and so the term that we're + + align:start position:0% +kinetics and so the term that we're + + + align:start position:0% +kinetics and so the term that we're +going to introduce is called Big K + + align:start position:0% +going to introduce is called Big K + + + align:start position:0% +going to introduce is called Big K +to the Little M the Michaelis Menton + + align:start position:0% +to the Little M the Michaelis Menton + + + align:start position:0% +to the Little M the Michaelis Menton +constant and so the Michaelis Menton + + align:start position:0% +constant and so the Michaelis Menton + + + align:start position:0% +constant and so the Michaelis Menton +constant and we'll talk about what this + + align:start position:0% +constant and we'll talk about what this + + + align:start position:0% +constant and we'll talk about what this +really means what this constant means in + + align:start position:0% +really means what this constant means in + + + align:start position:0% +really means what this constant means in +Practical terms in in a couple minutes + + align:start position:0% +Practical terms in in a couple minutes + + + align:start position:0% +Practical terms in in a couple minutes +um km equals kus1 + K2 ided + + align:start position:0% +um km equals kus1 + K2 ided + + + align:start position:0% +um km equals kus1 + K2 ided +K1 so now we somehow want to get this + + align:start position:0% +K1 so now we somehow want to get this + + + align:start position:0% +K1 so now we somehow want to get this +term into this expression + + align:start position:0% + + + + align:start position:0% + +so here's the expression again we want + + align:start position:0% +so here's the expression again we want + + + align:start position:0% +so here's the expression again we want +this term in here so if you notice at + + align:start position:0% +this term in here so if you notice at + + + align:start position:0% +this term in here so if you notice at +the bottom here there's a k minus one + + align:start position:0% +the bottom here there's a k minus one + + + align:start position:0% +the bottom here there's a k minus one +and a K2 just like there is here so if + + align:start position:0% +and a K2 just like there is here so if + + + align:start position:0% +and a K2 just like there is here so if +we divided these two by K1 we would have + + align:start position:0% +we divided these two by K1 we would have + + + align:start position:0% +we divided these two by K1 we would have +km over here but if we do that we have + + align:start position:0% +km over here but if we do that we have + + + align:start position:0% +km over here but if we do that we have +to divide everything by + + align:start position:0% +to divide everything by + + + align:start position:0% +to divide everything by +K1 so let's divide everything by K1 and + + align:start position:0% +K1 so let's divide everything by K1 and + + + align:start position:0% +K1 so let's divide everything by K1 and +turn this part of the expression into a + + align:start position:0% +turn this part of the expression into a + + + align:start position:0% +turn this part of the expression into a +km so if we do that we divide the top + + align:start position:0% +km so if we do that we divide the top + + + align:start position:0% +km so if we do that we divide the top +term by K1 we divide this term here k1s + + align:start position:0% +term by K1 we divide this term here k1s + + + align:start position:0% +term by K1 we divide this term here k1s +by K1 and we divide these two by + + align:start position:0% +by K1 and we divide these two by + + + align:start position:0% +by K1 and we divide these two by +K1 and we do that because now this is + + align:start position:0% +K1 and we do that because now this is + + + align:start position:0% +K1 and we do that because now this is +going to be equal to km all right so we + + align:start position:0% +going to be equal to km all right so we + + + align:start position:0% +going to be equal to km all right so we +can simplify this expression uh we have + + align:start position:0% +can simplify this expression uh we have + + + align:start position:0% +can simplify this expression uh we have +uh various things that we can cross out + + align:start position:0% +uh various things that we can cross out + + + align:start position:0% +uh various things that we can cross out +so if we do that see you can cross these + + align:start position:0% +so if we do that see you can cross these + + + align:start position:0% +so if we do that see you can cross these +two out up here can also cross these two + + align:start position:0% +two out up here can also cross these two + + + align:start position:0% +two out up here can also cross these two +out down here and what is that leave us + + align:start position:0% +out down here and what is that leave us + + + align:start position:0% +out down here and what is that leave us +with that leaves us with this so the top + + align:start position:0% +with that leaves us with this so the top + + + align:start position:0% +with that leaves us with this so the top +term we have total enzyme concentration + + align:start position:0% +term we have total enzyme concentration + + + align:start position:0% +term we have total enzyme concentration +times substrate + + align:start position:0% +times substrate + + + align:start position:0% +times substrate +concentration over substrate + + align:start position:0% +concentration over substrate + + + align:start position:0% +concentration over substrate +concentration plus this term here which + + align:start position:0% +concentration plus this term here which + + + align:start position:0% +concentration plus this term here which +is KNM so we've taken something that was + + align:start position:0% +is KNM so we've taken something that was + + + align:start position:0% +is KNM so we've taken something that was +a little bit more clunky and uh turned + + align:start position:0% +a little bit more clunky and uh turned + + + align:start position:0% +a little bit more clunky and uh turned +it into an expression that has a few + + align:start position:0% +it into an expression that has a few + + + align:start position:0% +it into an expression that has a few +fewer terms including uh this new term + + align:start position:0% +fewer terms including uh this new term + + + align:start position:0% +fewer terms including uh this new term +that's used for enzyme kinetics this KNM + + align:start position:0% + + + + align:start position:0% + +term now we can finally go back and take + + align:start position:0% +term now we can finally go back and take + + + align:start position:0% +term now we can finally go back and take +our term for uh the concentration of the + + align:start position:0% +our term for uh the concentration of the + + + align:start position:0% +our term for uh the concentration of the +intermediate and plug it into our rate + + align:start position:0% +intermediate and plug it into our rate + + + align:start position:0% +intermediate and plug it into our rate +law for formation of product so again + + align:start position:0% +law for formation of product so again + + + align:start position:0% +law for formation of product so again +this was our uh expression for the rate + + align:start position:0% +this was our uh expression for the rate + + + align:start position:0% +this was our uh expression for the rate +of product formation K2 times the + + align:start position:0% +of product formation K2 times the + + + align:start position:0% +of product formation K2 times the +concentration of es and and we can take + + align:start position:0% +concentration of es and and we can take + + + align:start position:0% +concentration of es and and we can take +this and plug that in + + align:start position:0% + + + + align:start position:0% + +here and that gives us this term K2 * + + align:start position:0% +here and that gives us this term K2 * + + + align:start position:0% +here and that gives us this term K2 * +total enzyme time substrate over + + align:start position:0% +total enzyme time substrate over + + + align:start position:0% +total enzyme time substrate over +substrate plus KNM and this is the + + align:start position:0% +substrate plus KNM and this is the + + + align:start position:0% +substrate plus KNM and this is the +Michaela me an equation so we used a lot + + align:start position:0% +Michaela me an equation so we used a lot + + + align:start position:0% +Michaela me an equation so we used a lot +of the use a steady state approximation + + align:start position:0% +of the use a steady state approximation + + + align:start position:0% +of the use a steady state approximation +we solved for an intermediate we did two + + align:start position:0% +we solved for an intermediate we did two + + + align:start position:0% +we solved for an intermediate we did two +things differently we didn't solve for + + align:start position:0% +things differently we didn't solve for + + + align:start position:0% +things differently we didn't solve for +free enzyme we solve for total enzyme + + align:start position:0% +free enzyme we solve for total enzyme + + + align:start position:0% +free enzyme we solve for total enzyme +and we also introduced this term km and + + align:start position:0% +and we also introduced this term km and + + + align:start position:0% +and we also introduced this term km and +and uh took out some of the individual + + align:start position:0% +and uh took out some of the individual + + + align:start position:0% +and uh took out some of the individual +rate constants and expressed them in + + align:start position:0% +rate constants and expressed them in + + + align:start position:0% +rate constants and expressed them in +terms of this uh of this constant so + + align:start position:0% +terms of this uh of this constant so + + + align:start position:0% +terms of this uh of this constant so +here is our rate equation for formation + + align:start position:0% +here is our rate equation for formation + + + align:start position:0% +here is our rate equation for formation +of product now let's think about what + + align:start position:0% +of product now let's think about what + + + align:start position:0% +of product now let's think about what +this equation can do what what it means + + align:start position:0% +this equation can do what what it means + + + align:start position:0% +this equation can do what what it means +what happens when enzyme is making + + align:start position:0% +what happens when enzyme is making + + + align:start position:0% +what happens when enzyme is making +product is acting as the Catalyst and + + align:start position:0% +product is acting as the Catalyst and + + + align:start position:0% +product is acting as the Catalyst and +turning our substrate into + + align:start position:0% +turning our substrate into + + + align:start position:0% +turning our substrate into +product so here would be a graph of uh + + align:start position:0% +product so here would be a graph of uh + + + align:start position:0% +product so here would be a graph of uh +what it might look look like you have + + align:start position:0% +what it might look look like you have + + + align:start position:0% +what it might look look like you have +here the rate of formation of product + + align:start position:0% +here the rate of formation of product + + + align:start position:0% +here the rate of formation of product +expressed as dpdt so that's just rate of + + align:start position:0% +expressed as dpdt so that's just rate of + + + align:start position:0% +expressed as dpdt so that's just rate of +product formation versus substrate + + align:start position:0% +product formation versus substrate + + + align:start position:0% +product formation versus substrate +concentration and you see that the curve + + align:start position:0% +concentration and you see that the curve + + + align:start position:0% +concentration and you see that the curve +goes up and then levels off so so what's + + align:start position:0% +goes up and then levels off so so what's + + + align:start position:0% +goes up and then levels off so so what's +happening in this + + align:start position:0% +happening in this + + + align:start position:0% +happening in this +case well at low substrate concentration + + align:start position:0% +case well at low substrate concentration + + + align:start position:0% +case well at low substrate concentration +and down here so this this is low + + align:start position:0% +and down here so this this is low + + + align:start position:0% +and down here so this this is low +substrate concentration at low substrate + + align:start position:0% +substrate concentration at low substrate + + + align:start position:0% +substrate concentration at low substrate +concentration when you add more + + align:start position:0% +concentration when you add more + + + align:start position:0% +concentration when you add more +substrate + + align:start position:0% +substrate + + + align:start position:0% +substrate +uh the rate goes up quite quickly and + + align:start position:0% +uh the rate goes up quite quickly and + + + align:start position:0% +uh the rate goes up quite quickly and +then starts to level off and at low + + align:start position:0% +then starts to level off and at low + + + align:start position:0% +then starts to level off and at low +substrate concentration incre adding + + align:start position:0% +substrate concentration incre adding + + + align:start position:0% +substrate concentration incre adding +more substrate increases the rate a lot + + align:start position:0% +more substrate increases the rate a lot + + + align:start position:0% +more substrate increases the rate a lot +because there's a bunch of enzyme that's + + align:start position:0% +because there's a bunch of enzyme that's + + + align:start position:0% +because there's a bunch of enzyme that's +free that's just hanging out and it's + + align:start position:0% +free that's just hanging out and it's + + + align:start position:0% +free that's just hanging out and it's +not making product because it doesn't + + align:start position:0% +not making product because it doesn't + + + align:start position:0% +not making product because it doesn't +have any substrate but you give it + + align:start position:0% +have any substrate but you give it + + + align:start position:0% +have any substrate but you give it +substrate and it'll quickly make product + + align:start position:0% +substrate and it'll quickly make product + + + align:start position:0% +substrate and it'll quickly make product +so that's what's happening you have lots + + align:start position:0% +so that's what's happening you have lots + + + align:start position:0% +so that's what's happening you have lots +of free enzyme around it's ready for + + align:start position:0% +of free enzyme around it's ready for + + + align:start position:0% +of free enzyme around it's ready for +substrate when you add substrate it + + align:start position:0% +substrate when you add substrate it + + + align:start position:0% +substrate when you add substrate it +reacts lots of pro is formed so why + + align:start position:0% +reacts lots of pro is formed so why + + + align:start position:0% +reacts lots of pro is formed so why +would it level off well it will level + + align:start position:0% +would it level off well it will level + + + align:start position:0% +would it level off well it will level +off at higher substrate + + align:start position:0% +off at higher substrate + + + align:start position:0% +off at higher substrate +concentrations because the en at higher + + align:start position:0% +concentrations because the en at higher + + + align:start position:0% +concentrations because the en at higher +substrate concentrations there really + + align:start position:0% +substrate concentrations there really + + + align:start position:0% +substrate concentrations there really +isn't any free enzyme around anymore so + + align:start position:0% +isn't any free enzyme around anymore so + + + align:start position:0% +isn't any free enzyme around anymore so +adding more substrate when the enzyme + + align:start position:0% +adding more substrate when the enzyme + + + align:start position:0% +adding more substrate when the enzyme +already has substrate bound is not going + + align:start position:0% +already has substrate bound is not going + + + align:start position:0% +already has substrate bound is not going +to increase the rate at which the + + align:start position:0% +to increase the rate at which the + + + align:start position:0% +to increase the rate at which the +products being formed when we say that + + align:start position:0% +products being formed when we say that + + + align:start position:0% +products being formed when we say that +the enzyme is saturated the enzyme + + align:start position:0% +the enzyme is saturated the enzyme + + + align:start position:0% +the enzyme is saturated the enzyme +already has as much substrate as it can + + align:start position:0% +already has as much substrate as it can + + + align:start position:0% +already has as much substrate as it can +use and you just have to wait until it + + align:start position:0% +use and you just have to wait until it + + + align:start position:0% +use and you just have to wait until it +finishes the uh reaction to product + + align:start position:0% +finishes the uh reaction to product + + + align:start position:0% +finishes the uh reaction to product +before a new substrate uh can be bound + + align:start position:0% +before a new substrate uh can be bound + + + align:start position:0% +before a new substrate uh can be bound +so the rate is going to level off at + + align:start position:0% +so the rate is going to level off at + + + align:start position:0% +so the rate is going to level off at +some point because there's no free + + align:start position:0% +some point because there's no free + + + align:start position:0% +some point because there's no free +enzyme around you've saturated with + + align:start position:0% +enzyme around you've saturated with + + + align:start position:0% +enzyme around you've saturated with +substrate adding more doesn't help your + + align:start position:0% +substrate adding more doesn't help your + + + align:start position:0% +substrate adding more doesn't help your +raid so we can think about this in terms + + align:start position:0% +raid so we can think about this in terms + + + align:start position:0% +raid so we can think about this in terms +of the Michaelis Menton + + align:start position:0% +of the Michaelis Menton + + + align:start position:0% +of the Michaelis Menton +equation so we can think about when + + align:start position:0% +equation so we can think about when + + + align:start position:0% +equation so we can think about when +substrate concentrations are really high + + align:start position:0% +substrate concentrations are really high + + + align:start position:0% +substrate concentrations are really high +when you have lots of substrates and we + + align:start position:0% +when you have lots of substrates and we + + + align:start position:0% +when you have lots of substrates and we +can think about that in terms of this + + align:start position:0% +can think about that in terms of this + + + align:start position:0% +can think about that in terms of this +value for km so again we're looking here + + align:start position:0% +value for km so again we're looking here + + + align:start position:0% +value for km so again we're looking here +at the bottom of this equation and we're + + align:start position:0% +at the bottom of this equation and we're + + + align:start position:0% +at the bottom of this equation and we're +thinking about how big is this term + + align:start position:0% +thinking about how big is this term + + + align:start position:0% +thinking about how big is this term +compared to that term so under + + align:start position:0% +compared to that term so under + + + align:start position:0% +compared to that term so under +conditions of the experiment where + + align:start position:0% +conditions of the experiment where + + + align:start position:0% +conditions of the experiment where +substrate concentration is a much bigger + + align:start position:0% +substrate concentration is a much bigger + + + align:start position:0% +substrate concentration is a much bigger +number than + + align:start position:0% +number than + + + align:start position:0% +number than +km we can get rid of the km term so we + + align:start position:0% +km we can get rid of the km term so we + + + align:start position:0% +km we can get rid of the km term so we +can cross this out again if you a really + + align:start position:0% +can cross this out again if you a really + + + align:start position:0% +can cross this out again if you a really +big number in the denominator added to a + + align:start position:0% +big number in the denominator added to a + + + align:start position:0% +big number in the denominator added to a +much smaller number the much smaller + + align:start position:0% +much smaller number the much smaller + + + align:start position:0% +much smaller number the much smaller +number isn't really contributing much + + align:start position:0% +number isn't really contributing much + + + align:start position:0% +number isn't really contributing much +and you can just get rid of it now we + + align:start position:0% +and you can just get rid of it now we + + + align:start position:0% +and you can just get rid of it now we +can simplify this equation then if we + + align:start position:0% +can simplify this equation then if we + + + align:start position:0% +can simplify this equation then if we +did that what else could we cancel + + align:start position:0% + + + + align:start position:0% + +out we can cancel out s can get rid of + + align:start position:0% +out we can cancel out s can get rid of + + + align:start position:0% +out we can cancel out s can get rid of +our + + align:start position:0% +our + + + align:start position:0% +our +substrate and that leaves us with this + + align:start position:0% +substrate and that leaves us with this + + + align:start position:0% +substrate and that leaves us with this +expression that the rate of formation of + + align:start position:0% +expression that the rate of formation of + + + align:start position:0% +expression that the rate of formation of +product under these conditions when + + align:start position:0% +product under these conditions when + + + align:start position:0% +product under these conditions when +substrate is is a much bigger number + + align:start position:0% +substrate is is a much bigger number + + + align:start position:0% +substrate is is a much bigger number +than this km term then we get this + + align:start position:0% +than this km term then we get this + + + align:start position:0% +than this km term then we get this +expression that the rate is just equal + + align:start position:0% +expression that the rate is just equal + + + align:start position:0% +expression that the rate is just equal +to K2 times the total enzyme that we had + + align:start position:0% +to K2 times the total enzyme that we had + + + align:start position:0% +to K2 times the total enzyme that we had +in our reaction and this has a + + align:start position:0% +in our reaction and this has a + + + align:start position:0% +in our reaction and this has a +name and it's called + + align:start position:0% +name and it's called + + + align:start position:0% +name and it's called +Vmax so Vmax equals K2 * total enzyme + + align:start position:0% +Vmax so Vmax equals K2 * total enzyme + + + align:start position:0% +Vmax so Vmax equals K2 * total enzyme +and Vmax is the maximum rate of the of + + align:start position:0% +and Vmax is the maximum rate of the of + + + align:start position:0% +and Vmax is the maximum rate of the of +the reaction and so when you have lots + + align:start position:0% +the reaction and so when you have lots + + + align:start position:0% +the reaction and so when you have lots +and lots of substrates you're under + + align:start position:0% +and lots of substrates you're under + + + align:start position:0% +and lots of substrates you're under +under these conditions where you can + + align:start position:0% +under these conditions where you can + + + align:start position:0% +under these conditions where you can +determine the maximum rate of the enzyme + + align:start position:0% +determine the maximum rate of the enzyme + + + align:start position:0% +determine the maximum rate of the enzyme +the Vmax of the enzyme and it's only + + align:start position:0% +the Vmax of the enzyme and it's only + + + align:start position:0% +the Vmax of the enzyme and it's only +equal to this K2 times how much ever + + align:start position:0% +equal to this K2 times how much ever + + + align:start position:0% +equal to this K2 times how much ever +enzyme you had in that particular + + align:start position:0% +enzyme you had in that particular + + + align:start position:0% +enzyme you had in that particular +experiment again the maximum rate of the + + align:start position:0% +experiment again the maximum rate of the + + + align:start position:0% +experiment again the maximum rate of the +enzyme under these + + align:start position:0% +enzyme under these + + + align:start position:0% +enzyme under these +conditions so again that would be up + + align:start position:0% +conditions so again that would be up + + + align:start position:0% +conditions so again that would be up +here the rate levels off when you have + + align:start position:0% +here the rate levels off when you have + + + align:start position:0% +here the rate levels off when you have +high substrate concentration then you're + + align:start position:0% +high substrate concentration then you're + + + align:start position:0% +high substrate concentration then you're +at the maximum rate the enzyme can't go + + align:start position:0% +at the maximum rate the enzyme can't go + + + align:start position:0% +at the maximum rate the enzyme can't go +any faster at that point uh it just + + align:start position:0% +any faster at that point uh it just + + + align:start position:0% +any faster at that point uh it just +depends on how the rate depends on how + + align:start position:0% +depends on how the rate depends on how + + + align:start position:0% +depends on how the rate depends on how +much enzyme you have and the K2 + + align:start position:0% + + + + align:start position:0% + +term so now let's consider uh this + + align:start position:0% +term so now let's consider uh this + + + align:start position:0% +term so now let's consider uh this +scenario where these two terms at the + + align:start position:0% +scenario where these two terms at the + + + align:start position:0% +scenario where these two terms at the +bottom of the expression are equal to + + align:start position:0% +bottom of the expression are equal to + + + align:start position:0% +bottom of the expression are equal to +each other when substrate equals km the + + align:start position:0% +each other when substrate equals km the + + + align:start position:0% +each other when substrate equals km the +concentration of substrate equals km so + + align:start position:0% +concentration of substrate equals km so + + + align:start position:0% +concentration of substrate equals km so +if those are equal we can get rid of the + + align:start position:0% +if those are equal we can get rid of the + + + align:start position:0% +if those are equal we can get rid of the +knen term and put in another substrate + + align:start position:0% +knen term and put in another substrate + + + align:start position:0% +knen term and put in another substrate +term because they're equal + + align:start position:0% +term because they're equal + + + align:start position:0% +term because they're equal +so we'll just put in uh another + + align:start position:0% +so we'll just put in uh another + + + align:start position:0% +so we'll just put in uh another +substrate term and uh then we can + + align:start position:0% +substrate term and uh then we can + + + align:start position:0% +substrate term and uh then we can +simplify + + align:start position:0% +simplify + + + align:start position:0% +simplify +again so two two substrates are down + + align:start position:0% +again so two two substrates are down + + + align:start position:0% +again so two two substrates are down +here one is up here we can cancel one of + + align:start position:0% +here one is up here we can cancel one of + + + align:start position:0% +here one is up here we can cancel one of +them and get the following so we cancel + + align:start position:0% +them and get the following so we cancel + + + align:start position:0% +them and get the following so we cancel +one we have 12 K2 times the total enzyme + + align:start position:0% +one we have 12 K2 times the total enzyme + + + align:start position:0% +one we have 12 K2 times the total enzyme +concentration and this would be + + align:start position:0% +concentration and this would be + + + align:start position:0% +concentration and this would be +then the half maximal rate + + align:start position:0% +then the half maximal rate + + + align:start position:0% +then the half maximal rate +so the maximal rate was K2 times the + + align:start position:0% +so the maximal rate was K2 times the + + + align:start position:0% +so the maximal rate was K2 times the +enzyme concent total enzyme + + align:start position:0% +enzyme concent total enzyme + + + align:start position:0% +enzyme concent total enzyme +concentration half maximal is half that + + align:start position:0% + + + + align:start position:0% + +rate and now we can finally Define + + align:start position:0% +rate and now we can finally Define + + + align:start position:0% +rate and now we can finally Define +km we can Define km as the concentration + + align:start position:0% +km we can Define km as the concentration + + + align:start position:0% +km we can Define km as the concentration +of substrate for which the rate is half + + align:start position:0% +of substrate for which the rate is half + + + align:start position:0% +of substrate for which the rate is half +maximum so uh the concentration of + + align:start position:0% +maximum so uh the concentration of + + + align:start position:0% +maximum so uh the concentration of +substrate when you have this this half + + align:start position:0% +substrate when you have this this half + + + align:start position:0% +substrate when you have this this half +maximal rate that's what km is and so + + align:start position:0% +maximal rate that's what km is and so + + + align:start position:0% +maximal rate that's what km is and so +this is a term that's easy to measure + + align:start position:0% +this is a term that's easy to measure + + + align:start position:0% +this is a term that's easy to measure +then and that's why we did some + + align:start position:0% +then and that's why we did some + + + align:start position:0% +then and that's why we did some +manipulations to get it into our + + align:start position:0% +manipulations to get it into our + + + align:start position:0% +manipulations to get it into our +equation because it's a term where you + + align:start position:0% +equation because it's a term where you + + + align:start position:0% +equation because it's a term where you +can find the answer the km value so if + + align:start position:0% +can find the answer the km value so if + + + align:start position:0% +can find the answer the km value so if +you know the maximal rate you can find + + align:start position:0% +you know the maximal rate you can find + + + align:start position:0% +you know the maximal rate you can find +the half maximal rate and figure out + + align:start position:0% +the half maximal rate and figure out + + + align:start position:0% +the half maximal rate and figure out +what substrate concentration gives you + + align:start position:0% +what substrate concentration gives you + + + align:start position:0% +what substrate concentration gives you +that half maximal rate and that's just + + align:start position:0% +that half maximal rate and that's just + + + align:start position:0% +that half maximal rate and that's just +going to be your km so in some problems + + align:start position:0% +going to be your km so in some problems + + + align:start position:0% +going to be your km so in some problems +that you're going to have in the extra + + align:start position:0% +that you're going to have in the extra + + + align:start position:0% +that you're going to have in the extra +problems that are posted it may tell you + + align:start position:0% +problems that are posted it may tell you + + + align:start position:0% +problems that are posted it may tell you +the maximal rate and uh then tell you + + align:start position:0% +the maximal rate and uh then tell you + + + align:start position:0% +the maximal rate and uh then tell you +the substrate concentration that gives + + align:start position:0% +the substrate concentration that gives + + + align:start position:0% +the substrate concentration that gives +you the half maximal rate and you have + + align:start position:0% +you the half maximal rate and you have + + + align:start position:0% +you the half maximal rate and you have +to find the km well that's not a hard + + align:start position:0% +to find the km well that's not a hard + + + align:start position:0% +to find the km well that's not a hard +problem if you're told the substrate + + align:start position:0% +problem if you're told the substrate + + + align:start position:0% +problem if you're told the substrate +concentration that gives you the half + + align:start position:0% +concentration that gives you the half + + + align:start position:0% +concentration that gives you the half +maximal rate that is the km so it's just + + align:start position:0% +maximal rate that is the km so it's just + + + align:start position:0% +maximal rate that is the km so it's just +a matter of knowing the definition so + + align:start position:0% +a matter of knowing the definition so + + + align:start position:0% +a matter of knowing the definition so +the levels of problems that you have in + + align:start position:0% +the levels of problems that you have in + + + align:start position:0% +the levels of problems that you have in +your chapter on enzyme kinetics are + + align:start position:0% +your chapter on enzyme kinetics are + + + align:start position:0% +your chapter on enzyme kinetics are +really pretty simple if you know if you + + align:start position:0% +really pretty simple if you know if you + + + align:start position:0% +really pretty simple if you know if you +know some of the definitions you're all + + align:start position:0% +know some of the definitions you're all + + + align:start position:0% +know some of the definitions you're all +set so finally let's just look at + + align:start position:0% +set so finally let's just look at + + + align:start position:0% +set so finally let's just look at +Inhibitors in the last uh few + + align:start position:0% +Inhibitors in the last uh few + + + align:start position:0% +Inhibitors in the last uh few +minutes so um this is a very simplistic + + align:start position:0% +minutes so um this is a very simplistic + + + align:start position:0% +minutes so um this is a very simplistic +view of uh of an inhibitor situation so + + align:start position:0% +view of uh of an inhibitor situation so + + + align:start position:0% +view of uh of an inhibitor situation so +if your inhibitor is I it may bind to + + align:start position:0% +if your inhibitor is I it may bind to + + + align:start position:0% +if your inhibitor is I it may bind to +your free enzyme to give you an EI + + align:start position:0% +your free enzyme to give you an EI + + + align:start position:0% +your free enzyme to give you an EI +complex an inhibitor bound complex and + + align:start position:0% +complex an inhibitor bound complex and + + + align:start position:0% +complex an inhibitor bound complex and +if the inhibitor is bound in the active + + align:start position:0% +if the inhibitor is bound in the active + + + align:start position:0% +if the inhibitor is bound in the active +site and it's bound pretty well + + align:start position:0% +site and it's bound pretty well + + + align:start position:0% +site and it's bound pretty well +substrate's going to come along but it + + align:start position:0% +substrate's going to come along but it + + + align:start position:0% +substrate's going to come along but it +can't bind so you can't make any product + + align:start position:0% +can't bind so you can't make any product + + + align:start position:0% +can't bind so you can't make any product +so uh the inhibitor has stopped the + + align:start position:0% +so uh the inhibitor has stopped the + + + align:start position:0% +so uh the inhibitor has stopped the +activity so that's just a very + + align:start position:0% +activity so that's just a very + + + align:start position:0% +activity so that's just a very +simplistic scheme of what can be going + + align:start position:0% + + + + align:start position:0% + +on so many Pharmaceuticals work are are + + align:start position:0% +on so many Pharmaceuticals work are are + + + align:start position:0% +on so many Pharmaceuticals work are are +enzyme Inhibitors that's that's what + + align:start position:0% +enzyme Inhibitors that's that's what + + + align:start position:0% +enzyme Inhibitors that's that's what +they do uh so they stop uh enzymes + + align:start position:0% +they do uh so they stop uh enzymes + + + align:start position:0% +they do uh so they stop uh enzymes +biological catalysts and the way in + + align:start position:0% +biological catalysts and the way in + + + align:start position:0% +biological catalysts and the way in +which they work often is that they're + + align:start position:0% +which they work often is that they're + + + align:start position:0% +which they work often is that they're +designed the inhibitor is designed to + + align:start position:0% +designed the inhibitor is designed to + + + align:start position:0% +designed the inhibitor is designed to +mimic the transition state of of the uh + + align:start position:0% +mimic the transition state of of the uh + + + align:start position:0% +mimic the transition state of of the uh +reaction so if you have things coming + + align:start position:0% +reaction so if you have things coming + + + align:start position:0% +reaction so if you have things coming +together and they form a activated + + align:start position:0% +together and they form a activated + + + align:start position:0% +together and they form a activated +complex or transition state before they + + align:start position:0% +complex or transition state before they + + + align:start position:0% +complex or transition state before they +go on to say form products often the + + align:start position:0% +go on to say form products often the + + + align:start position:0% +go on to say form products often the +inhibitor is designed to look like that + + align:start position:0% +inhibitor is designed to look like that + + + align:start position:0% +inhibitor is designed to look like that +transition state that's formed + + align:start position:0% + + + + align:start position:0% + +so the reason why it would do this is + + align:start position:0% +so the reason why it would do this is + + + align:start position:0% +so the reason why it would do this is +because molecules that resemble the + + align:start position:0% +because molecules that resemble the + + + align:start position:0% +because molecules that resemble the +transition state should bind more + + align:start position:0% +transition state should bind more + + + align:start position:0% +transition state should bind more +tightly uh to the enzyme than either the + + align:start position:0% +tightly uh to the enzyme than either the + + + align:start position:0% +tightly uh to the enzyme than either the +reactants or the products and so + + align:start position:0% +reactants or the products and so + + + align:start position:0% +reactants or the products and so +therefore they can serve as effective + + align:start position:0% +therefore they can serve as effective + + + align:start position:0% +therefore they can serve as effective +Inhibitors so if you just recall what we + + align:start position:0% +Inhibitors so if you just recall what we + + + align:start position:0% +Inhibitors so if you just recall what we +showed at the beginning of the talk uh + + align:start position:0% +showed at the beginning of the talk uh + + + align:start position:0% +showed at the beginning of the talk uh +catalysts work by lowering this barrier + + align:start position:0% +catalysts work by lowering this barrier + + + align:start position:0% +catalysts work by lowering this barrier +or by stabilizing the transition state + + align:start position:0% +or by stabilizing the transition state + + + align:start position:0% +or by stabilizing the transition state +bringing the transition state to a lower + + align:start position:0% +bringing the transition state to a lower + + + align:start position:0% +bringing the transition state to a lower +energy and so often uh Inhibitors that + + align:start position:0% +energy and so often uh Inhibitors that + + + align:start position:0% +energy and so often uh Inhibitors that +look like a transition state will bind + + align:start position:0% +look like a transition state will bind + + + align:start position:0% +look like a transition state will bind +to the enzyme quite tightly and you want + + align:start position:0% +to the enzyme quite tightly and you want + + + align:start position:0% +to the enzyme quite tightly and you want +the inhibitor to bind tightly because + + align:start position:0% +the inhibitor to bind tightly because + + + align:start position:0% +the inhibitor to bind tightly because +you don't want substrate to be able to + + align:start position:0% +you don't want substrate to be able to + + + align:start position:0% +you don't want substrate to be able to +come along and displace the inhibitor if + + align:start position:0% +come along and displace the inhibitor if + + + align:start position:0% +come along and displace the inhibitor if +you're trying to stop the enzyme from + + align:start position:0% +you're trying to stop the enzyme from + + + align:start position:0% +you're trying to stop the enzyme from +working you want a tightly bound + + align:start position:0% +working you want a tightly bound + + + align:start position:0% +working you want a tightly bound +inhibitor so they often look to the + + align:start position:0% +inhibitor so they often look to the + + + align:start position:0% +inhibitor so they often look to the +transition state and let me just give + + align:start position:0% +transition state and let me just give + + + align:start position:0% +transition state and let me just give +you one example that's been uh pretty + + align:start position:0% +you one example that's been uh pretty + + + align:start position:0% +you one example that's been uh pretty +successful + + align:start position:0% +successful + + + align:start position:0% +successful +uh and that is with protas Inhibitors uh + + align:start position:0% +uh and that is with protas Inhibitors uh + + + align:start position:0% +uh and that is with protas Inhibitors uh +so protas Inhibitors are used in the + + align:start position:0% +so protas Inhibitors are used in the + + + align:start position:0% +so protas Inhibitors are used in the +treatment of + + align:start position:0% +treatment of + + + align:start position:0% +treatment of +HIV and um the uh proteases are enzymes + + align:start position:0% +HIV and um the uh proteases are enzymes + + + align:start position:0% +HIV and um the uh proteases are enzymes +which cleave peptide bonds and so we + + align:start position:0% +which cleave peptide bonds and so we + + + align:start position:0% +which cleave peptide bonds and so we +talked about the formation of a peptide + + align:start position:0% +talked about the formation of a peptide + + + align:start position:0% +talked about the formation of a peptide +bond so this is a reaction that + + align:start position:0% +bond so this is a reaction that + + + align:start position:0% +bond so this is a reaction that +catalyzes the reverse process breaking + + align:start position:0% +catalyzes the reverse process breaking + + + align:start position:0% +catalyzes the reverse process breaking +down the peptide bond and so here might + + align:start position:0% +down the peptide bond and so here might + + + align:start position:0% +down the peptide bond and so here might +be a Rea simplified reaction mechanism + + align:start position:0% +be a Rea simplified reaction mechanism + + + align:start position:0% +be a Rea simplified reaction mechanism +uh you have something coming in a + + align:start position:0% +uh you have something coming in a + + + align:start position:0% +uh you have something coming in a +attacking here's your peptide bond + + align:start position:0% +attacking here's your peptide bond + + + align:start position:0% +attacking here's your peptide bond +you're forming a tetrahedral + + align:start position:0% +you're forming a tetrahedral + + + align:start position:0% +you're forming a tetrahedral +intermediate here and what would be the + + align:start position:0% +intermediate here and what would be the + + + align:start position:0% +intermediate here and what would be the +angles of a tetrahedral + + align:start position:0% + + + + align:start position:0% + +intermediate + + align:start position:0% +intermediate + + + align:start position:0% +intermediate +109.5 and then this would break down and + + align:start position:0% +109.5 and then this would break down and + + + align:start position:0% +109.5 and then this would break down and +you would form these two products so the + + align:start position:0% +you would form these two products so the + + + align:start position:0% +you would form these two products so the +peptide bond then gets cleaved and so uh + + align:start position:0% +peptide bond then gets cleaved and so uh + + + align:start position:0% +peptide bond then gets cleaved and so uh +designers of Inhibitors or + + align:start position:0% +designers of Inhibitors or + + + align:start position:0% +designers of Inhibitors or +pharmaceutical drugs have tried to mimic + + align:start position:0% +pharmaceutical drugs have tried to mimic + + + align:start position:0% +pharmaceutical drugs have tried to mimic +this tetrahedral inter immediate to try + + align:start position:0% +this tetrahedral inter immediate to try + + + align:start position:0% +this tetrahedral inter immediate to try +to get tight binding so you have the + + align:start position:0% +to get tight binding so you have the + + + align:start position:0% +to get tight binding so you have the +idea that uh molecules with this uh + + align:start position:0% +idea that uh molecules with this uh + + + align:start position:0% +idea that uh molecules with this uh +stabal tetrahedral site that can't be + + align:start position:0% +stabal tetrahedral site that can't be + + + align:start position:0% +stabal tetrahedral site that can't be +cleaved uh could bind to the enzyme uh + + align:start position:0% +cleaved uh could bind to the enzyme uh + + + align:start position:0% +cleaved uh could bind to the enzyme uh +more tightly than than uh substrate and + + align:start position:0% +more tightly than than uh substrate and + + + align:start position:0% +more tightly than than uh substrate and +this is just one example of a drug that + + align:start position:0% +this is just one example of a drug that + + + align:start position:0% +this is just one example of a drug that +inhibits HIV protease that has that + + align:start position:0% +inhibits HIV protease that has that + + + align:start position:0% +inhibits HIV protease that has that +stable + + align:start position:0% +stable + + + align:start position:0% +stable +tetrahedral uh site where that cannot be + + align:start position:0% +tetrahedral uh site where that cannot be + + + align:start position:0% +tetrahedral uh site where that cannot be +cleaved I'm almost done so here's a + + align:start position:0% +cleaved I'm almost done so here's a + + + align:start position:0% +cleaved I'm almost done so here's a +picture of it bound uh to the enzyme so + + align:start position:0% +picture of it bound uh to the enzyme so + + + align:start position:0% +picture of it bound uh to the enzyme so +here's the inhibitor bound to the active + + align:start position:0% +here's the inhibitor bound to the active + + + align:start position:0% +here's the inhibitor bound to the active +site so it fits quite well in there um + + align:start position:0% +site so it fits quite well in there um + + + align:start position:0% +site so it fits quite well in there um +and let me just mention finally that one + + align:start position:0% +and let me just mention finally that one + + + align:start position:0% +and let me just mention finally that one +problem with designing Inhibitors toward + + align:start position:0% +problem with designing Inhibitors toward + + + align:start position:0% +problem with designing Inhibitors toward +enzymes there's many in this case many + + align:start position:0% +enzymes there's many in this case many + + + align:start position:0% +enzymes there's many in this case many +proteases so you might not want to stop + + align:start position:0% +proteases so you might not want to stop + + + align:start position:0% +proteases so you might not want to stop +all proteases from working you only want + + align:start position:0% +all proteases from working you only want + + + align:start position:0% +all proteases from working you only want +to stop the HIV protease from working so + + align:start position:0% +to stop the HIV protease from working so + + + align:start position:0% +to stop the HIV protease from working so +there's a lot of issues of specificity + + align:start position:0% +there's a lot of issues of specificity + + + align:start position:0% +there's a lot of issues of specificity +so that's one of the complication of + + align:start position:0% +so that's one of the complication of + + + align:start position:0% +so that's one of the complication of +drug design design and that again is + + align:start position:0% +drug design design and that again is + + + align:start position:0% +drug design design and that again is +another important uh area for you to + + align:start position:0% +another important uh area for you to + + + align:start position:0% +another important uh area for you to +think about doing uh there's still a + + align:start position:0% +think about doing uh there's still a + + + align:start position:0% +think about doing uh there's still a +huge problem with HIV uh not so as much + + align:start position:0% +huge problem with HIV uh not so as much + + + align:start position:0% +huge problem with HIV uh not so as much +in the US but in other countries so it's + + align:start position:0% +in the US but in other countries so it's + + + align:start position:0% +in the US but in other countries so it's +something else you can think about doing + + align:start position:0% +something else you can think about doing + + + align:start position:0% +something else you can think about doing +all right see you Wednesday \ No newline at end of file diff --git a/aBEZyrqUV28.txt b/aBEZyrqUV28.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ed29ba4d3614884b591cedda7ee54d586d2e38b --- /dev/null +++ b/aBEZyrqUV28.txt @@ -0,0 +1,2763 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +electrostatic precipitation demonstrates + + align:start position:0% +electrostatic precipitation demonstrates + + + align:start position:0% +electrostatic precipitation demonstrates +how air ions generated by a Corona + + align:start position:0% +how air ions generated by a Corona + + + align:start position:0% +how air ions generated by a Corona +discharge can be used to charge + + align:start position:0% +discharge can be used to charge + + + align:start position:0% +discharge can be used to charge +macroscopic + + align:start position:0% +macroscopic + + + align:start position:0% +macroscopic +particles and how those particles can + + align:start position:0% +particles and how those particles can + + + align:start position:0% +particles and how those particles can +then be removed from the air by the + + align:start position:0% +then be removed from the air by the + + + align:start position:0% +then be removed from the air by the +applied electric + + align:start position:0% + + + + align:start position:0% + +field in an electric field e a particle + + align:start position:0% +field in an electric field e a particle + + + align:start position:0% +field in an electric field e a particle +having the charge Q is subject to the + + align:start position:0% +having the charge Q is subject to the + + + align:start position:0% +having the charge Q is subject to the +Loren Force + + align:start position:0% + + + + align:start position:0% + +for particles such as dust and smoke in + + align:start position:0% +for particles such as dust and smoke in + + + align:start position:0% +for particles such as dust and smoke in +air their velocity is so low that even + + align:start position:0% +air their velocity is so low that even + + + align:start position:0% +air their velocity is so low that even +if there were much of an applied + + align:start position:0% +if there were much of an applied + + + align:start position:0% +if there were much of an applied +magnetic field its contribution would be + + align:start position:0% + + + + align:start position:0% + +negligible in air the inertia of fine + + align:start position:0% +negligible in air the inertia of fine + + + align:start position:0% +negligible in air the inertia of fine +particles is often + + align:start position:0% +particles is often + + + align:start position:0% +particles is often +negligible the electrical force is + + align:start position:0% +negligible the electrical force is + + + align:start position:0% +negligible the electrical force is +balanced by a drag + + align:start position:0% +balanced by a drag + + + align:start position:0% +balanced by a drag +Force this drag force is proportional to + + align:start position:0% +Force this drag force is proportional to + + + align:start position:0% +Force this drag force is proportional to +the particles velocity V relative to the + + align:start position:0% +the particles velocity V relative to the + + + align:start position:0% +the particles velocity V relative to the +air for example if such particles were + + align:start position:0% +air for example if such particles were + + + align:start position:0% +air for example if such particles were +spherical with a radius + + align:start position:0% +spherical with a radius + + + align:start position:0% +spherical with a radius +R this force would be the Stokes drag + + align:start position:0% +R this force would be the Stokes drag + + + align:start position:0% +R this force would be the Stokes drag +where Ada is the viscosity of + + align:start position:0% +where Ada is the viscosity of + + + align:start position:0% +where Ada is the viscosity of +air the particle velocity is then + + align:start position:0% +air the particle velocity is then + + + align:start position:0% +air the particle velocity is then +proportional to the applied electric + + align:start position:0% + + + + align:start position:0% + +field the particle velocity is + + align:start position:0% +field the particle velocity is + + + align:start position:0% +field the particle velocity is +proportional to the applied electric + + align:start position:0% +proportional to the applied electric + + + align:start position:0% +proportional to the applied electric +field the coefficient relating the + + align:start position:0% +field the coefficient relating the + + + align:start position:0% +field the coefficient relating the +particle velocity to the electric field + + align:start position:0% +particle velocity to the electric field + + + align:start position:0% +particle velocity to the electric field +intensity mu is defined as the + + align:start position:0% +intensity mu is defined as the + + + align:start position:0% +intensity mu is defined as the +mobility it is generally proportional to + + align:start position:0% +mobility it is generally proportional to + + + align:start position:0% +mobility it is generally proportional to +the particle charge + + align:start position:0% + + + + align:start position:0% + +Q if these particles are the only ones + + align:start position:0% +Q if these particles are the only ones + + + align:start position:0% +Q if these particles are the only ones +that are charged and moving the current + + align:start position:0% +that are charged and moving the current + + + align:start position:0% +that are charged and moving the current +density is the product of their + + align:start position:0% +density is the product of their + + + align:start position:0% +density is the product of their +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +and the charge density + + align:start position:0% +and the charge density + + + align:start position:0% +and the charge density +Row the product of mu and row is an + + align:start position:0% +Row the product of mu and row is an + + + align:start position:0% +Row the product of mu and row is an +effective + + align:start position:0% +effective + + + align:start position:0% +effective +conductivity unlike the conductivity + + align:start position:0% +conductivity unlike the conductivity + + + align:start position:0% +conductivity unlike the conductivity +associated with an omic model this + + align:start position:0% +associated with an omic model this + + + align:start position:0% +associated with an omic model this +conductivity is a function of a variable + + align:start position:0% +conductivity is a function of a variable + + + align:start position:0% +conductivity is a function of a variable +that is itself as much a function of + + align:start position:0% +that is itself as much a function of + + + align:start position:0% +that is itself as much a function of +space as the + + align:start position:0% +space as the + + + align:start position:0% +space as the +potential although the mobility formula + + align:start position:0% +potential although the mobility formula + + + align:start position:0% +potential although the mobility formula +is strictly only applicable to + + align:start position:0% +is strictly only applicable to + + + align:start position:0% +is strictly only applicable to +macroscopic spherical particles more + + align:start position:0% +macroscopic spherical particles more + + + align:start position:0% +macroscopic spherical particles more +than about5 micrometer in diameter and + + align:start position:0% +than about5 micrometer in diameter and + + + align:start position:0% +than about5 micrometer in diameter and +yet small enough that their inertia is + + align:start position:0% +yet small enough that their inertia is + + + align:start position:0% +yet small enough that their inertia is +negligible the expressions for the + + align:start position:0% +negligible the expressions for the + + + align:start position:0% +negligible the expressions for the +velocity and current density are useful + + align:start position:0% +velocity and current density are useful + + + align:start position:0% +velocity and current density are useful +for describing both the macroscopic + + align:start position:0% +for describing both the macroscopic + + + align:start position:0% +for describing both the macroscopic +particles and the ions that now account + + align:start position:0% +particles and the ions that now account + + + align:start position:0% +particles and the ions that now account +for what we + + align:start position:0% + + + + align:start position:0% + +observe the apparatus consists of these + + align:start position:0% +observe the apparatus consists of these + + + align:start position:0% +observe the apparatus consists of these +coaxial + + align:start position:0% + + + + align:start position:0% + +conductors the outer one is essentially + + align:start position:0% + + + + align:start position:0% + +grounded + + align:start position:0% +grounded + + + align:start position:0% +grounded +the inner one this fine + + align:start position:0% +the inner one this fine + + + align:start position:0% +the inner one this fine +wire is connected to the high voltage + + align:start position:0% + + + + align:start position:0% + +generator although it's made of glass so + + align:start position:0% +generator although it's made of glass so + + + align:start position:0% +generator although it's made of glass so +that we can see through it this cylinder + + align:start position:0% +that we can see through it this cylinder + + + align:start position:0% +that we can see through it this cylinder +is coated on the inside by tin oxide so + + align:start position:0% +is coated on the inside by tin oxide so + + + align:start position:0% +is coated on the inside by tin oxide so +that it is + + align:start position:0% +that it is + + + align:start position:0% +that it is +conducting for the present purposes it + + align:start position:0% +conducting for the present purposes it + + + align:start position:0% +conducting for the present purposes it +can be regarded as a perfect + + align:start position:0% +can be regarded as a perfect + + + align:start position:0% +can be regarded as a perfect +conductor it's grounded + + align:start position:0% +conductor it's grounded + + + align:start position:0% +conductor it's grounded +through this micro am + + align:start position:0% + + + + align:start position:0% + +meter this fine wire is stretched along + + align:start position:0% +meter this fine wire is stretched along + + + align:start position:0% +meter this fine wire is stretched along +the axis of the + + align:start position:0% +the axis of the + + + align:start position:0% +the axis of the +cylinder it's connected to a positive + + align:start position:0% +cylinder it's connected to a positive + + + align:start position:0% +cylinder it's connected to a positive +source of high + + align:start position:0% + + + + align:start position:0% + +voltage because we only require modest + + align:start position:0% +voltage because we only require modest + + + align:start position:0% +voltage because we only require modest +currents we can protect ourselves by + + align:start position:0% +currents we can protect ourselves by + + + align:start position:0% +currents we can protect ourselves by +having a series + + align:start position:0% +having a series + + + align:start position:0% +having a series +resistance to limit the short circuit + + align:start position:0% +resistance to limit the short circuit + + + align:start position:0% +resistance to limit the short circuit +current + + align:start position:0% + + + + align:start position:0% + +the voltage is indicated by this + + align:start position:0% + + + + align:start position:0% + +meter because the wire is so fine + + align:start position:0% +meter because the wire is so fine + + + align:start position:0% +meter because the wire is so fine +raising its voltage results in + + align:start position:0% +raising its voltage results in + + + align:start position:0% +raising its voltage results in +ionization of the air in a hissing + + align:start position:0% +ionization of the air in a hissing + + + align:start position:0% +ionization of the air in a hissing +electrical + + align:start position:0% +electrical + + + align:start position:0% +electrical +breakdown this discharge is confined to + + align:start position:0% +breakdown this discharge is confined to + + + align:start position:0% +breakdown this discharge is confined to +the immediate vicinity of the + + align:start position:0% +the immediate vicinity of the + + + align:start position:0% +the immediate vicinity of the +wire with the help of this microphone we + + align:start position:0% +wire with the help of this microphone we + + + align:start position:0% +wire with the help of this microphone we +can hear this Corona + + align:start position:0% +can hear this Corona + + + align:start position:0% +can hear this Corona +discharge as it starts as the voltage is + + align:start position:0% +discharge as it starts as the voltage is + + + align:start position:0% +discharge as it starts as the voltage is +raised + + align:start position:0% + + + + align:start position:0% + +it starts at just a little more than 10 + + align:start position:0% + + + + align:start position:0% + +kilts + + align:start position:0% + + + + align:start position:0% + +pairs of ions generated by the corona + + align:start position:0% +pairs of ions generated by the corona + + + align:start position:0% +pairs of ions generated by the corona +discharge are separated by the electric + + align:start position:0% +discharge are separated by the electric + + + align:start position:0% +discharge are separated by the electric +field some of the positive ones follow + + align:start position:0% +field some of the positive ones follow + + + align:start position:0% +field some of the positive ones follow +the field lines to the outer + + align:start position:0% +the field lines to the outer + + + align:start position:0% +the field lines to the outer +cylinder + + align:start position:0% +cylinder + + + align:start position:0% +cylinder +thus as we raise the voltage and he the + + align:start position:0% +thus as we raise the voltage and he the + + + align:start position:0% +thus as we raise the voltage and he the +discharge start there should be an onset + + align:start position:0% +discharge start there should be an onset + + + align:start position:0% +discharge start there should be an onset +of current passing from the inner wire + + align:start position:0% +of current passing from the inner wire + + + align:start position:0% +of current passing from the inner wire +to the outer + + align:start position:0% +to the outer + + + align:start position:0% +to the outer +cylinder we can measure that current + + align:start position:0% +cylinder we can measure that current + + + align:start position:0% +cylinder we can measure that current +with this micro am + + align:start position:0% + + + + align:start position:0% + +meter here's the microamp meter 10 + + align:start position:0% +meter here's the microamp meter 10 + + + align:start position:0% +meter here's the microamp meter 10 +microamps full + + align:start position:0% +microamps full + + + align:start position:0% +microamps full +scale here's the + + align:start position:0% +scale here's the + + + align:start position:0% +scale here's the +voltmeter let's watch the current as we + + align:start position:0% +voltmeter let's watch the current as we + + + align:start position:0% +voltmeter let's watch the current as we +again raise the voltage + + align:start position:0% +again raise the voltage + + + align:start position:0% +again raise the voltage +and listen to the + + align:start position:0% + + + + align:start position:0% + +discharge we have two other evidences of + + align:start position:0% +discharge we have two other evidences of + + + align:start position:0% +discharge we have two other evidences of +the corona discharge one is the smell of + + align:start position:0% +the corona discharge one is the smell of + + + align:start position:0% +the corona discharge one is the smell of +ozone generated by the + + align:start position:0% +ozone generated by the + + + align:start position:0% +ozone generated by the +discharge the odor is deceivingly like + + align:start position:0% +discharge the odor is deceivingly like + + + align:start position:0% +discharge the odor is deceivingly like +that associated with fresh + + align:start position:0% +that associated with fresh + + + align:start position:0% +that associated with fresh +air you can't appreciate that but if we + + align:start position:0% +air you can't appreciate that but if we + + + align:start position:0% +air you can't appreciate that but if we +turn the lights out and make the camera + + align:start position:0% +turn the lights out and make the camera + + + align:start position:0% +turn the lights out and make the camera +as sensitive as possible we might be + + align:start position:0% +as sensitive as possible we might be + + + align:start position:0% +as sensitive as possible we might be +able to see + + align:start position:0% + + + + align:start position:0% + +it perhaps you can see the slight bluish + + align:start position:0% +it perhaps you can see the slight bluish + + + align:start position:0% +it perhaps you can see the slight bluish +discharge that is uniform typical of a + + align:start position:0% +discharge that is uniform typical of a + + + align:start position:0% +discharge that is uniform typical of a +positive + + align:start position:0% + + + + align:start position:0% + +discharge + + align:start position:0% + + + + align:start position:0% + +the current and voltage provide enough + + align:start position:0% +the current and voltage provide enough + + + align:start position:0% +the current and voltage provide enough +information to estimate the effective + + align:start position:0% + + + + align:start position:0% + +conductivity at 12 kilovolts the current + + align:start position:0% +conductivity at 12 kilovolts the current + + + align:start position:0% +conductivity at 12 kilovolts the current +is 10 + + align:start position:0% + + + + align:start position:0% + +microamp this total current is the + + align:start position:0% +microamp this total current is the + + + align:start position:0% +microamp this total current is the +current density at the outer wall + + align:start position:0% +current density at the outer wall + + + align:start position:0% +current density at the outer wall +multiplied by its area + + align:start position:0% +multiplied by its area + + + align:start position:0% +multiplied by its area +a the current density is in turn the + + align:start position:0% +a the current density is in turn the + + + align:start position:0% +a the current density is in turn the +product of the mobility the charge + + align:start position:0% +product of the mobility the charge + + + align:start position:0% +product of the mobility the charge +density and the field intensity at the + + align:start position:0% +density and the field intensity at the + + + align:start position:0% +density and the field intensity at the +outer + + align:start position:0% +outer + + + align:start position:0% +outer +wall so the effective conductivity is + + align:start position:0% +wall so the effective conductivity is + + + align:start position:0% +wall so the effective conductivity is +the total current divided by the product + + align:start position:0% +the total current divided by the product + + + align:start position:0% +the total current divided by the product +of the field in density and the + + align:start position:0% +of the field in density and the + + + align:start position:0% +of the field in density and the +area the electric field in this coaxial + + align:start position:0% +area the electric field in this coaxial + + + align:start position:0% +area the electric field in this coaxial +geometry is not uniform so if we take e + + align:start position:0% +geometry is not uniform so if we take e + + + align:start position:0% +geometry is not uniform so if we take e +to B the voltage divided by the spacing + + align:start position:0% +to B the voltage divided by the spacing + + + align:start position:0% +to B the voltage divided by the spacing +between the wire and the outer cylinder + + align:start position:0% +between the wire and the outer cylinder + + + align:start position:0% +between the wire and the outer cylinder +it would seem to be a very crude + + align:start position:0% +it would seem to be a very crude + + + align:start position:0% +it would seem to be a very crude +approximation however the space charge + + align:start position:0% +approximation however the space charge + + + align:start position:0% +approximation however the space charge +due to the ions tends to make the field + + align:start position:0% +due to the ions tends to make the field + + + align:start position:0% +due to the ions tends to make the field +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +uniform so we take e as being + + align:start position:0% +uniform so we take e as being + + + align:start position:0% +uniform so we take e as being +approximately 12 Kilts divided by 6 cm + + align:start position:0% +approximately 12 Kilts divided by 6 cm + + + align:start position:0% +approximately 12 Kilts divided by 6 cm +about 2 * 10 5th volts per + + align:start position:0% +about 2 * 10 5th volts per + + + align:start position:0% +about 2 * 10 5th volts per +meter the cylinder area is 2 pi * the + + align:start position:0% +meter the cylinder area is 2 pi * the + + + align:start position:0% +meter the cylinder area is 2 pi * the +radius times a height of4 + + align:start position:0% +radius times a height of4 + + + align:start position:0% +radius times a height of4 +M the effective conductivity is + + align:start position:0% +M the effective conductivity is + + + align:start position:0% +M the effective conductivity is +therefore about 3.3 * 10us 10 semans per + + align:start position:0% + + + + align:start position:0% + +meter the electric field is 2 * 10 5 + + align:start position:0% +meter the electric field is 2 * 10 5 + + + align:start position:0% +meter the electric field is 2 * 10 5 +Vols per + + align:start position:0% +Vols per + + + align:start position:0% +Vols per +meter the mobility of air ions is about + + align:start position:0% +meter the mobility of air ions is about + + + align:start position:0% +meter the mobility of air ions is about +1 * 10 - 4 m/s per volt per + + align:start position:0% +1 * 10 - 4 m/s per volt per + + + align:start position:0% +1 * 10 - 4 m/s per volt per +meter the velocity of an ion with a + + align:start position:0% +meter the velocity of an ion with a + + + align:start position:0% +meter the velocity of an ion with a +voltage at 12 KT is therefore about 20 + + align:start position:0% + + + + align:start position:0% + +m/s the time required for an ion to + + align:start position:0% +m/s the time required for an ion to + + + align:start position:0% +m/s the time required for an ion to +cross from the wire to the cylinder to + + align:start position:0% +cross from the wire to the cylinder to + + + align:start position:0% +cross from the wire to the cylinder to +travel the radius R of 6 + + align:start position:0% +travel the radius R of 6 + + + align:start position:0% +travel the radius R of 6 +cm is about 3 + + align:start position:0% + + + + align:start position:0% + +milliseconds common smoke alarms depend + + align:start position:0% +milliseconds common smoke alarms depend + + + align:start position:0% +milliseconds common smoke alarms depend +on the tendency of fine particles to + + align:start position:0% +on the tendency of fine particles to + + + align:start position:0% +on the tendency of fine particles to +collect these ions + + align:start position:0% +collect these ions + + + align:start position:0% +collect these ions +here we have a source of + + align:start position:0% +here we have a source of + + + align:start position:0% +here we have a source of +smoke watch what happens to the current + + align:start position:0% +smoke watch what happens to the current + + + align:start position:0% +smoke watch what happens to the current +as the smoke is + + align:start position:0% + + + + align:start position:0% + +introduced as the smoke enters the + + align:start position:0% +introduced as the smoke enters the + + + align:start position:0% +introduced as the smoke enters the +region of ionic conduction the curent is + + align:start position:0% +region of ionic conduction the curent is + + + align:start position:0% +region of ionic conduction the curent is +reduced let's see if we can explain + + align:start position:0% +reduced let's see if we can explain + + + align:start position:0% +reduced let's see if we can explain +this here greatly enlarged is a + + align:start position:0% +this here greatly enlarged is a + + + align:start position:0% +this here greatly enlarged is a +macroscopic particle such as comprises + + align:start position:0% +macroscopic particle such as comprises + + + align:start position:0% +macroscopic particle such as comprises +smoke under these circumstances it does + + align:start position:0% +smoke under these circumstances it does + + + align:start position:0% +smoke under these circumstances it does +not have to conduct much to behave as an + + align:start position:0% +not have to conduct much to behave as an + + + align:start position:0% +not have to conduct much to behave as an +essentially perfect + + align:start position:0% +essentially perfect + + + align:start position:0% +essentially perfect +conductor thus in the vicinity of the + + align:start position:0% +conductor thus in the vicinity of the + + + align:start position:0% +conductor thus in the vicinity of the +particle field lines tend to terminate + + align:start position:0% +particle field lines tend to terminate + + + align:start position:0% +particle field lines tend to terminate +on its South Pole and emanate from its + + align:start position:0% +on its South Pole and emanate from its + + + align:start position:0% +on its South Pole and emanate from its +North + + align:start position:0% +North + + + align:start position:0% +North +Pole + + align:start position:0% + + + + align:start position:0% + +ions migrating along these lines + + align:start position:0% +ions migrating along these lines + + + align:start position:0% +ions migrating along these lines +terminating on the South Pole impact the + + align:start position:0% +terminating on the South Pole impact the + + + align:start position:0% +terminating on the South Pole impact the +surface of the + + align:start position:0% +surface of the + + + align:start position:0% +surface of the +particle as the ions accumulate so does + + align:start position:0% +particle as the ions accumulate so does + + + align:start position:0% +particle as the ions accumulate so does +the net charge Q of the macroscopic + + align:start position:0% +the net charge Q of the macroscopic + + + align:start position:0% +the net charge Q of the macroscopic +particle as the particle charges more + + align:start position:0% +particle as the particle charges more + + + align:start position:0% +particle as the particle charges more +and more of its surface sustains outward + + align:start position:0% +and more of its surface sustains outward + + + align:start position:0% +and more of its surface sustains outward +directed field + + align:start position:0% +directed field + + + align:start position:0% +directed field +lines as it charges the southern window + + align:start position:0% +lines as it charges the southern window + + + align:start position:0% +lines as it charges the southern window +over which ions can impact the particle + + align:start position:0% +over which ions can impact the particle + + + align:start position:0% +over which ions can impact the particle +closes so there's a maximum charge that + + align:start position:0% +closes so there's a maximum charge that + + + align:start position:0% +closes so there's a maximum charge that +can accumulate on the + + align:start position:0% +can accumulate on the + + + align:start position:0% +can accumulate on the +particle this maximum charge is reached + + align:start position:0% +particle this maximum charge is reached + + + align:start position:0% +particle this maximum charge is reached +when the radial electric field is + + align:start position:0% +when the radial electric field is + + + align:start position:0% +when the radial electric field is +everywhere outward on the + + align:start position:0% + + + + align:start position:0% + +surface here's the time + + align:start position:0% +surface here's the time + + + align:start position:0% +surface here's the time +dependence of the charge on a particle + + align:start position:0% +dependence of the charge on a particle + + + align:start position:0% +dependence of the charge on a particle +having no initial + + align:start position:0% +having no initial + + + align:start position:0% +having no initial +charge the charge saturates at a + + align:start position:0% +charge the charge saturates at a + + + align:start position:0% +charge the charge saturates at a +critical charge Q + + align:start position:0% + + + + align:start position:0% + +subc This critical charge is is + + align:start position:0% +subc This critical charge is is + + + align:start position:0% +subc This critical charge is is +independent of the mobility or ion + + align:start position:0% +independent of the mobility or ion + + + align:start position:0% +independent of the mobility or ion +density and is proportional to esay the + + align:start position:0% +density and is proportional to esay the + + + align:start position:0% +density and is proportional to esay the +field intensity in the neighborhood of + + align:start position:0% +field intensity in the neighborhood of + + + align:start position:0% +field intensity in the neighborhood of +the + + align:start position:0% +the + + + align:start position:0% +the +particle and proportional to the + + align:start position:0% +particle and proportional to the + + + align:start position:0% +particle and proportional to the +particle surface + + align:start position:0% + + + + align:start position:0% + +area + + align:start position:0% +area + + + align:start position:0% +area +to is the rate with which the particle + + align:start position:0% +to is the rate with which the particle + + + align:start position:0% +to is the rate with which the particle +charges it depends on the effective + + align:start position:0% +charges it depends on the effective + + + align:start position:0% +charges it depends on the effective +conductivity mu row in a similar way as + + align:start position:0% +conductivity mu row in a similar way as + + + align:start position:0% +conductivity mu row in a similar way as +for the charge relaxation time of an + + align:start position:0% +for the charge relaxation time of an + + + align:start position:0% +for the charge relaxation time of an +omic + + align:start position:0% +omic + + + align:start position:0% +omic +conductor + + align:start position:0% +conductor + + + align:start position:0% +conductor +at 12 Kilts we found an effective + + align:start position:0% +at 12 Kilts we found an effective + + + align:start position:0% +at 12 Kilts we found an effective +conductivity to be 3.3 * 10us 10 C per + + align:start position:0% +conductivity to be 3.3 * 10us 10 C per + + + align:start position:0% +conductivity to be 3.3 * 10us 10 C per +meter so our ions can give an + + align:start position:0% +meter so our ions can give an + + + align:start position:0% +meter so our ions can give an +appreciable charge to a smoke particle + + align:start position:0% +appreciable charge to a smoke particle + + + align:start position:0% +appreciable charge to a smoke particle +within about 1/10th of a + + align:start position:0% + + + + align:start position:0% + +second once charged the smoke particles + + align:start position:0% +second once charged the smoke particles + + + align:start position:0% +second once charged the smoke particles +are themselves pulled toward the outer + + align:start position:0% +are themselves pulled toward the outer + + + align:start position:0% +are themselves pulled toward the outer +electrode by the electric + + align:start position:0% +electrode by the electric + + + align:start position:0% +electrode by the electric +field let's see this + + align:start position:0% +field let's see this + + + align:start position:0% +field let's see this +happen with the voltage off and the + + align:start position:0% +happen with the voltage off and the + + + align:start position:0% +happen with the voltage off and the +upper end of the cylinder closed + + align:start position:0% + + + + align:start position:0% + +off we'll fill it with + + align:start position:0% + + + + align:start position:0% + +smoke watch the smoke as the voltage is + + align:start position:0% + + + + align:start position:0% + +applied the particles are presumably + + align:start position:0% +applied the particles are presumably + + + align:start position:0% +applied the particles are presumably +charged in less than a tenth of a second + + align:start position:0% +charged in less than a tenth of a second + + + align:start position:0% +charged in less than a tenth of a second +so the charging time cannot account for + + align:start position:0% +so the charging time cannot account for + + + align:start position:0% +so the charging time cannot account for +the few seconds it takes to precipitate + + align:start position:0% +the few seconds it takes to precipitate + + + align:start position:0% +the few seconds it takes to precipitate +the Smoke On The + + align:start position:0% + + + + align:start position:0% + +Wall apparently these smoke particles do + + align:start position:0% +Wall apparently these smoke particles do + + + align:start position:0% +Wall apparently these smoke particles do +not move through the air with nearly the + + align:start position:0% +not move through the air with nearly the + + + align:start position:0% +not move through the air with nearly the +velocity of the ions which we estimated + + align:start position:0% +velocity of the ions which we estimated + + + align:start position:0% +velocity of the ions which we estimated +to be on the order of 20 m/s or + + align:start position:0% +to be on the order of 20 m/s or + + + align:start position:0% +to be on the order of 20 m/s or +more we can see that this is so by + + align:start position:0% +more we can see that this is so by + + + align:start position:0% +more we can see that this is so by +calculating the velocity of a smoke + + align:start position:0% + + + + align:start position:0% + +particle first we approximate the + + align:start position:0% +particle first we approximate the + + + align:start position:0% +particle first we approximate the +largest charge that can accumulate on a + + align:start position:0% +largest charge that can accumulate on a + + + align:start position:0% +largest charge that can accumulate on a +smoke particle we guess that the + + align:start position:0% +smoke particle we guess that the + + + align:start position:0% +smoke particle we guess that the +particle has a radius of half a + + align:start position:0% +particle has a radius of half a + + + align:start position:0% +particle has a radius of half a +micrometer and use the same average + + align:start position:0% +micrometer and use the same average + + + align:start position:0% +micrometer and use the same average +field as + + align:start position:0% +field as + + + align:start position:0% +field as +before then the charge per particle is + + align:start position:0% +before then the charge per particle is + + + align:start position:0% +before then the charge per particle is +about 1.7 * 10-7 + + align:start position:0% +about 1.7 * 10-7 + + + align:start position:0% +about 1.7 * 10-7 +K that's about 100 electronic + + align:start position:0% +K that's about 100 electronic + + + align:start position:0% +K that's about 100 electronic +charges it follows that the mobility of + + align:start position:0% +charges it follows that the mobility of + + + align:start position:0% +charges it follows that the mobility of +the smoke is this charge divided by 6 pi + + align:start position:0% +the smoke is this charge divided by 6 pi + + + align:start position:0% +the smoke is this charge divided by 6 pi +times the viscosity of + + align:start position:0% +times the viscosity of + + + align:start position:0% +times the viscosity of +air and the particle + + align:start position:0% +air and the particle + + + align:start position:0% +air and the particle +radius the mobility of the smoke is + + align:start position:0% +radius the mobility of the smoke is + + + align:start position:0% +radius the mobility of the smoke is +about 10- 7 m/s per volt per + + align:start position:0% +about 10- 7 m/s per volt per + + + align:start position:0% +about 10- 7 m/s per volt per +meter about 1,000 times less than for + + align:start position:0% +meter about 1,000 times less than for + + + align:start position:0% +meter about 1,000 times less than for +the ions + + align:start position:0% +the ions + + + align:start position:0% +the ions +so in our field 2 * 10 5th Vols per + + align:start position:0% +so in our field 2 * 10 5th Vols per + + + align:start position:0% +so in our field 2 * 10 5th Vols per +meter the smoke particle moves with a + + align:start position:0% +meter the smoke particle moves with a + + + align:start position:0% +meter the smoke particle moves with a +velocity of 2 cm/ second about a + + align:start position:0% +velocity of 2 cm/ second about a + + + align:start position:0% +velocity of 2 cm/ second about a +thousand times slower than the + + align:start position:0% + + + + align:start position:0% + +ions what we see at relatively large + + align:start position:0% +ions what we see at relatively large + + + align:start position:0% +ions what we see at relatively large +particle densities is particle motions + + align:start position:0% +particle densities is particle motions + + + align:start position:0% +particle densities is particle motions +that are Complicated by the motion of + + align:start position:0% +that are Complicated by the motion of + + + align:start position:0% +that are Complicated by the motion of +the air + + align:start position:0% +the air + + + align:start position:0% +the air +itself induced by both the ions and the + + align:start position:0% +itself induced by both the ions and the + + + align:start position:0% +itself induced by both the ions and the +particles this is typical of practical + + align:start position:0% +particles this is typical of practical + + + align:start position:0% +particles this is typical of practical +precipitators which are used for air + + align:start position:0% +precipitators which are used for air + + + align:start position:0% +precipitators which are used for air +pollution control + + align:start position:0% + + + + align:start position:0% + +purposes + + align:start position:0% + + + + align:start position:0% + +the macroscopic particle motions can be + + align:start position:0% +the macroscopic particle motions can be + + + align:start position:0% +the macroscopic particle motions can be +made more evident by using styrofoam + + align:start position:0% +made more evident by using styrofoam + + + align:start position:0% +made more evident by using styrofoam +particles rather than the + + align:start position:0% + + + + align:start position:0% + +smoke Watch What Happens as they + + align:start position:0% +smoke Watch What Happens as they + + + align:start position:0% +smoke Watch What Happens as they +encounter the combination of radially + + align:start position:0% +encounter the combination of radially + + + align:start position:0% +encounter the combination of radially +migrating ions and Radial electric + + align:start position:0% +migrating ions and Radial electric + + + align:start position:0% +migrating ions and Radial electric +field + + align:start position:0% + + + + align:start position:0% + +as long as the field is on the particles + + align:start position:0% +as long as the field is on the particles + + + align:start position:0% +as long as the field is on the particles +are electrically pinned to the + + align:start position:0% +are electrically pinned to the + + + align:start position:0% +are electrically pinned to the +wall but when the field is + + align:start position:0% +wall but when the field is + + + align:start position:0% +wall but when the field is +removed so is the pinning + + align:start position:0% +removed so is the pinning + + + align:start position:0% +removed so is the pinning +Force as purchased these particles are + + align:start position:0% +Force as purchased these particles are + + + align:start position:0% +Force as purchased these particles are +good insulators + + align:start position:0% + + + + align:start position:0% + +they're naturally sufficiently + + align:start position:0% +they're naturally sufficiently + + + align:start position:0% +they're naturally sufficiently +insulating that they can contact a + + align:start position:0% +insulating that they can contact a + + + align:start position:0% +insulating that they can contact a +conducting surface like the cylinder + + align:start position:0% +conducting surface like the cylinder + + + align:start position:0% +conducting surface like the cylinder +wall and still retain most of their + + align:start position:0% +wall and still retain most of their + + + align:start position:0% +wall and still retain most of their +charge if the charge were retained on + + align:start position:0% +charge if the charge were retained on + + + align:start position:0% +charge if the charge were retained on +the particles we would expect that they + + align:start position:0% +the particles we would expect that they + + + align:start position:0% +the particles we would expect that they +would stick to the wall after the field + + align:start position:0% +would stick to the wall after the field + + + align:start position:0% +would stick to the wall after the field +is + + align:start position:0% +is + + + align:start position:0% +is +removed to understand what we've seen we + + align:start position:0% +removed to understand what we've seen we + + + align:start position:0% +removed to understand what we've seen we +need to explain that these particles + + align:start position:0% +need to explain that these particles + + + align:start position:0% +need to explain that these particles +have been sprayed with antistatic agent + + align:start position:0% +have been sprayed with antistatic agent + + + align:start position:0% +have been sprayed with antistatic agent +much is used to prevent electrification + + align:start position:0% +much is used to prevent electrification + + + align:start position:0% +much is used to prevent electrification +of + + align:start position:0% +of + + + align:start position:0% +of +laundry so they charge leaks away after + + align:start position:0% +laundry so they charge leaks away after + + + align:start position:0% +laundry so they charge leaks away after +the field is + + align:start position:0% + + + + align:start position:0% + +removed our experiment illustrates the + + align:start position:0% +removed our experiment illustrates the + + + align:start position:0% +removed our experiment illustrates the +nature of two types of charged particles + + align:start position:0% +nature of two types of charged particles + + + align:start position:0% +nature of two types of charged particles +that are described by unipolar + + align:start position:0% +that are described by unipolar + + + align:start position:0% +that are described by unipolar +conduction of molecular Dimensions were + + align:start position:0% +conduction of molecular Dimensions were + + + align:start position:0% +conduction of molecular Dimensions were +the ions generated by a Corona + + align:start position:0% + + + + align:start position:0% + +discharge + + align:start position:0% + + + + align:start position:0% + +with mobilities of 10us 4 m/s per volt + + align:start position:0% +with mobilities of 10us 4 m/s per volt + + + align:start position:0% +with mobilities of 10us 4 m/s per volt +per meter they crossed through the air + + align:start position:0% +per meter they crossed through the air + + + align:start position:0% +per meter they crossed through the air +between the wire and the wall with a + + align:start position:0% +between the wire and the wall with a + + + align:start position:0% +between the wire and the wall with a +velocity of 20 + + align:start position:0% + + + + align:start position:0% + +m/s macroscopic particles of smoke + + align:start position:0% +m/s macroscopic particles of smoke + + + align:start position:0% +m/s macroscopic particles of smoke +passing through the ion flux were + + align:start position:0% +passing through the ion flux were + + + align:start position:0% +passing through the ion flux were +quickly charged to much higher levels + + align:start position:0% +quickly charged to much higher levels + + + align:start position:0% +quickly charged to much higher levels +than the + + align:start position:0% + + + + align:start position:0% + +ions because of their larger size they + + align:start position:0% +ions because of their larger size they + + + align:start position:0% +ions because of their larger size they +still had mobilities a thousand times + + align:start position:0% +still had mobilities a thousand times + + + align:start position:0% +still had mobilities a thousand times +less than the ions their velocities + + align:start position:0% +less than the ions their velocities + + + align:start position:0% +less than the ions their velocities +relative to the air were 1,000 times + + align:start position:0% +relative to the air were 1,000 times + + + align:start position:0% +relative to the air were 1,000 times +less than the + + align:start position:0% + + + + align:start position:0% + +ions ion impact charging of particles + + align:start position:0% +ions ion impact charging of particles + + + align:start position:0% +ions ion impact charging of particles +and the resulting electrical force + + align:start position:0% +and the resulting electrical force + + + align:start position:0% +and the resulting electrical force +explained what we saw using the + + align:start position:0% +explained what we saw using the + + + align:start position:0% +explained what we saw using the +styrofoam beads + + align:start position:0% + + + + align:start position:0% + +these particles have not been sprayed + + align:start position:0% +these particles have not been sprayed + + + align:start position:0% +these particles have not been sprayed +with antistatic + + align:start position:0% +with antistatic + + + align:start position:0% +with antistatic +agent they too are precipitated to the + + align:start position:0% +agent they too are precipitated to the + + + align:start position:0% +agent they too are precipitated to the +walls although in a somewhat different + + align:start position:0% + + + + align:start position:0% + +pattern however now when the power is + + align:start position:0% +pattern however now when the power is + + + align:start position:0% +pattern however now when the power is +turned + + align:start position:0% +turned + + + align:start position:0% +turned +off they tend to stick to the wall + + align:start position:0% +off they tend to stick to the wall + + + align:start position:0% +off they tend to stick to the wall +they're so highly insulating that they + + align:start position:0% +they're so highly insulating that they + + + align:start position:0% +they're so highly insulating that they +retain their + + align:start position:0% +retain their + + + align:start position:0% +retain their +charge we can either think of their + + align:start position:0% +charge we can either think of their + + + align:start position:0% +charge we can either think of their +being mutually repelled to the walls or + + align:start position:0% +being mutually repelled to the walls or + + + align:start position:0% +being mutually repelled to the walls or +of they're being attracted to the image + + align:start position:0% +of they're being attracted to the image + + + align:start position:0% +of they're being attracted to the image +charges on the + + align:start position:0% + + + + align:start position:0% + +walls the mutual repulsion of light + + align:start position:0% +walls the mutual repulsion of light + + + align:start position:0% +walls the mutual repulsion of light +charged particles is more evident when + + align:start position:0% +charged particles is more evident when + + + align:start position:0% +charged particles is more evident when +the cylinder is turned on its + + align:start position:0% + + + + align:start position:0% + +side once charged by ion impact and + + align:start position:0% +side once charged by ion impact and + + + align:start position:0% +side once charged by ion impact and +precipitated on the wall these particles + + align:start position:0% +precipitated on the wall these particles + + + align:start position:0% +precipitated on the wall these particles +retain their + + align:start position:0% + + + + align:start position:0% + +charge \ No newline at end of file diff --git a/aQAhRAn6ewc.txt b/aQAhRAn6ewc.txt new file mode 100644 index 0000000000000000000000000000000000000000..6ad4974e926fa454b51d963388dd30e868531c32 --- /dev/null +++ b/aQAhRAn6ewc.txt @@ -0,0 +1,819 @@ +align:start position:0% + +welcome back to + + align:start position:0% +welcome back to + + + align:start position:0% +welcome back to +820 special relativity + + align:start position:0% +820 special relativity + + + align:start position:0% +820 special relativity +so in this section we want to look again + + align:start position:0% +so in this section we want to look again + + + align:start position:0% +so in this section we want to look again +at collisions + + align:start position:0% +at collisions + + + align:start position:0% +at collisions +and study momentum conservation + + align:start position:0% +and study momentum conservation + + + align:start position:0% +and study momentum conservation +and so we have this scenario here in + + align:start position:0% +and so we have this scenario here in + + + align:start position:0% +and so we have this scenario here in +which we have you know two balls + + align:start position:0% +which we have you know two balls + + + align:start position:0% +which we have you know two balls +colliding with velocities u a and u b + + align:start position:0% +colliding with velocities u a and u b + + + align:start position:0% +colliding with velocities u a and u b +masses m a and m + + align:start position:0% +masses m a and m + + + align:start position:0% +masses m a and m +and after the collisions there the + + align:start position:0% +and after the collisions there the + + + align:start position:0% +and after the collisions there the +masses change to m c and m d and the + + align:start position:0% +masses change to m c and m d and the + + + align:start position:0% +masses change to m c and m d and the +velocities are u c and u d + + align:start position:0% +velocities are u c and u d + + + align:start position:0% +velocities are u c and u d +the + + align:start position:0% +the + + + align:start position:0% +the +random conservation tells you that the + + align:start position:0% +random conservation tells you that the + + + align:start position:0% +random conservation tells you that the +product of the mars and velocities + + align:start position:0% +product of the mars and velocities + + + align:start position:0% +product of the mars and velocities +and the sum of the two particles before + + align:start position:0% +and the sum of the two particles before + + + align:start position:0% +and the sum of the two particles before +and after the collisions is the same + + align:start position:0% +and after the collisions is the same + + + align:start position:0% +and after the collisions is the same +but now what happens if we boost the + + align:start position:0% +but now what happens if we boost the + + + align:start position:0% +but now what happens if we boost the +system if we + + align:start position:0% +system if we + + + align:start position:0% +system if we +look at the very same system with a + + align:start position:0% +look at the very same system with a + + + align:start position:0% +look at the very same system with a +boosted reference frame + + align:start position:0% +boosted reference frame + + + align:start position:0% +boosted reference frame +um you know and we can just + + align:start position:0% +um you know and we can just + + + align:start position:0% +um you know and we can just +you know simplify the case here by just + + align:start position:0% +you know simplify the case here by just + + + align:start position:0% +you know simplify the case here by just +considering the x direction + + align:start position:0% +considering the x direction + + + align:start position:0% +considering the x direction +so the question is if momentum is + + align:start position:0% +so the question is if momentum is + + + align:start position:0% +so the question is if momentum is +conserved in a frame s + + align:start position:0% +conserved in a frame s + + + align:start position:0% +conserved in a frame s +like the one we are looking here in this + + align:start position:0% +like the one we are looking here in this + + + align:start position:0% +like the one we are looking here in this +picture + + align:start position:0% +picture + + + align:start position:0% +picture +is the momentum also conserved in a + + align:start position:0% +is the momentum also conserved in a + + + align:start position:0% +is the momentum also conserved in a +moving reference frame + + align:start position:0% +moving reference frame + + + align:start position:0% +moving reference frame +with the relative velocity uh uh v + + align:start position:0% +with the relative velocity uh uh v + + + align:start position:0% +with the relative velocity uh uh v +and so you can show this quite easily + + align:start position:0% +and so you can show this quite easily + + + align:start position:0% +and so you can show this quite easily +that this is actually not the case right + + align:start position:0% +that this is actually not the case right + + + align:start position:0% +that this is actually not the case right +so you write down the velocities + + align:start position:0% +so you write down the velocities + + + align:start position:0% +so you write down the velocities +um + + align:start position:0% + + + + align:start position:0% + +the momentum equation the same equation + + align:start position:0% +the momentum equation the same equation + + + align:start position:0% +the momentum equation the same equation +as before with boosted velocities and + + align:start position:0% +as before with boosted velocities and + + + align:start position:0% +as before with boosted velocities and +you find that this is not the case you + + align:start position:0% +you find that this is not the case you + + + align:start position:0% +you find that this is not the case you +can easily show this by for example you + + align:start position:0% +can easily show this by for example you + + + align:start position:0% +can easily show this by for example you +know setting the right part of this + + align:start position:0% +know setting the right part of this + + + align:start position:0% +know setting the right part of this +equation to zero + + align:start position:0% +equation to zero + + + align:start position:0% +equation to zero +and see + + align:start position:0% +and see + + + align:start position:0% +and see +whether or not this this equation will + + align:start position:0% +whether or not this this equation will + + + align:start position:0% +whether or not this this equation will +hold true in general and it doesn't + + align:start position:0% +hold true in general and it doesn't + + + align:start position:0% +hold true in general and it doesn't +but + + align:start position:0% +but + + + align:start position:0% +but +in the last section we introduced the + + align:start position:0% +in the last section we introduced the + + + align:start position:0% +in the last section we introduced the +new concept of proper velocity + + align:start position:0% +new concept of proper velocity + + + align:start position:0% +new concept of proper velocity +so how about + + align:start position:0% +so how about + + + align:start position:0% +so how about +redefining momentum through proper + + align:start position:0% +redefining momentum through proper + + + align:start position:0% +redefining momentum through proper +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +and just saying + + align:start position:0% +and just saying + + + align:start position:0% +and just saying +m a times proper velocity a plus m b + + align:start position:0% +m a times proper velocity a plus m b + + + align:start position:0% +m a times proper velocity a plus m b +times proper velocity b + + align:start position:0% +times proper velocity b + + + align:start position:0% +times proper velocity b +is equal to m c + + align:start position:0% +is equal to m c + + + align:start position:0% +is equal to m c +times over velocity c and so on + + align:start position:0% +times over velocity c and so on + + + align:start position:0% +times over velocity c and so on +and see whether or not we can learn + + align:start position:0% +and see whether or not we can learn + + + align:start position:0% +and see whether or not we can learn +something from this equation + + align:start position:0% +something from this equation + + + align:start position:0% +something from this equation +so why don't we write down this very + + align:start position:0% +so why don't we write down this very + + + align:start position:0% +so why don't we write down this very +same equation and with proper velocity + + align:start position:0% +same equation and with proper velocity + + + align:start position:0% +same equation and with proper velocity +and see whether or not it's invariant in + + align:start position:0% +and see whether or not it's invariant in + + + align:start position:0% +and see whether or not it's invariant in +the lawrence transformation + + align:start position:0% +the lawrence transformation + + + align:start position:0% +the lawrence transformation +okay again a good moment to stop the + + align:start position:0% +okay again a good moment to stop the + + + align:start position:0% +okay again a good moment to stop the +video and just work out the mass by + + align:start position:0% +video and just work out the mass by + + + align:start position:0% +video and just work out the mass by +yourself on your own + + align:start position:0% +yourself on your own + + + align:start position:0% +yourself on your own +so i did this here + + align:start position:0% +so i did this here + + + align:start position:0% +so i did this here +and i'm just doing this for the x + + align:start position:0% +and i'm just doing this for the x + + + align:start position:0% +and i'm just doing this for the x +component so we have our proper velocity + + align:start position:0% +component so we have our proper velocity + + + align:start position:0% +component so we have our proper velocity +vector which is gamma times z + + align:start position:0% +vector which is gamma times z + + + align:start position:0% +vector which is gamma times z +gamma times ux gamma times u y and gamma + + align:start position:0% +gamma times ux gamma times u y and gamma + + + align:start position:0% +gamma times ux gamma times u y and gamma +times uz + + align:start position:0% +times uz + + + align:start position:0% +times uz +so the x component is the first + + align:start position:0% +so the x component is the first + + + align:start position:0% +so the x component is the first +component + + align:start position:0% +component + + + align:start position:0% +component +and + + align:start position:0% +and + + + align:start position:0% +and +in the boosted reference frame + + align:start position:0% +in the boosted reference frame + + + align:start position:0% +in the boosted reference frame +the + + align:start position:0% +the + + + align:start position:0% +the +proper velocity of the x component in + + align:start position:0% +proper velocity of the x component in + + + align:start position:0% +proper velocity of the x component in +our boosters frame is gamma times + + align:start position:0% +our boosters frame is gamma times + + + align:start position:0% +our boosters frame is gamma times +the proper velocity of the particle a + + align:start position:0% +the proper velocity of the particle a + + + align:start position:0% +the proper velocity of the particle a +first component minus beta proper + + align:start position:0% +first component minus beta proper + + + align:start position:0% +first component minus beta proper +velocity of a zeroth component + + align:start position:0% +velocity of a zeroth component + + + align:start position:0% +velocity of a zeroth component +and so then you can write your equation + + align:start position:0% + + + + align:start position:0% + +and this should be our momentum energy + + align:start position:0% +and this should be our momentum energy + + + align:start position:0% +and this should be our momentum energy +momentum conservation equation + + align:start position:0% +momentum conservation equation + + + align:start position:0% +momentum conservation equation +okay and the loans transformation we + + align:start position:0% +okay and the loans transformation we + + + align:start position:0% +okay and the loans transformation we +find this one here + + align:start position:0% +find this one here + + + align:start position:0% +find this one here +and so all we need to do now in order to + + align:start position:0% +and so all we need to do now in order to + + + align:start position:0% +and so all we need to do now in order to +show that this is always true or true in + + align:start position:0% +show that this is always true or true in + + + align:start position:0% +show that this is always true or true in +general is to + + align:start position:0% +general is to + + + align:start position:0% +general is to +re-assign relabel + + align:start position:0% +re-assign relabel + + + align:start position:0% +re-assign relabel +the reorder the individual terms and i + + align:start position:0% +the reorder the individual terms and i + + + align:start position:0% +the reorder the individual terms and i +did this here um to make this visible + + align:start position:0% +did this here um to make this visible + + + align:start position:0% +did this here um to make this visible +you see + + align:start position:0% +you see + + + align:start position:0% +you see +everything behind in this bracket behind + + align:start position:0% +everything behind in this bracket behind + + + align:start position:0% +everything behind in this bracket behind +the better is equal to the equation we + + align:start position:0% +the better is equal to the equation we + + + align:start position:0% +the better is equal to the equation we +had before there's a minus sign in + + align:start position:0% +had before there's a minus sign in + + + align:start position:0% +had before there's a minus sign in +between which means it's zero and + + align:start position:0% +between which means it's zero and + + + align:start position:0% +between which means it's zero and +everything we see on the top for the + + align:start position:0% +everything we see on the top for the + + + align:start position:0% +everything we see on the top for the +first component + + align:start position:0% +first component + + + align:start position:0% +first component +is also b0 that's for the boosted + + align:start position:0% +is also b0 that's for the boosted + + + align:start position:0% +is also b0 that's for the boosted +reference right so we see here and i + + align:start position:0% +reference right so we see here and i + + + align:start position:0% +reference right so we see here and i +just showed this for the x component you + + align:start position:0% +just showed this for the x component you + + + align:start position:0% +just showed this for the x component you +can show the for all component that + + align:start position:0% +can show the for all component that + + + align:start position:0% +can show the for all component that +momentum is conserved \ No newline at end of file diff --git a/an5E940fqZQ.txt b/an5E940fqZQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..c93cc3b19ae8d086c1f72abdb23de83ad04abe80 --- /dev/null +++ b/an5E940fqZQ.txt @@ -0,0 +1,6683 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% +of MIT courses visit mitop courseware at + + + align:start position:0% +of MIT courses visit mitop courseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi today we're going to conclude our + + align:start position:0% +hi today we're going to conclude our + + + align:start position:0% +hi today we're going to conclude our +study of linear differential equations + + align:start position:0% +study of linear differential equations + + + align:start position:0% +study of linear differential equations +and we're going to use the occasion to + + align:start position:0% +and we're going to use the occasion to + + + align:start position:0% +and we're going to use the occasion to +introduce the concept of AAS transform I + + align:start position:0% +introduce the concept of AAS transform I + + + align:start position:0% +introduce the concept of AAS transform I +should point out that the llas transform + + align:start position:0% +should point out that the llas transform + + + align:start position:0% +should point out that the llas transform +has much greater application than just + + align:start position:0% +has much greater application than just + + + align:start position:0% +has much greater application than just +to linear differential equations it's + + align:start position:0% +to linear differential equations it's + + + align:start position:0% +to linear differential equations it's +related to the Fier transform it has + + align:start position:0% +related to the Fier transform it has + + + align:start position:0% +related to the Fier transform it has +applications in the subject known as the + + align:start position:0% +applications in the subject known as the + + + align:start position:0% +applications in the subject known as the +convolution integral many applications + + align:start position:0% +convolution integral many applications + + + align:start position:0% +convolution integral many applications +which we'll talk about during the during + + align:start position:0% +which we'll talk about during the during + + + align:start position:0% +which we'll talk about during the during +the learning exercises in this unit but + + align:start position:0% +the learning exercises in this unit but + + + align:start position:0% +the learning exercises in this unit but +within the framework of linear + + align:start position:0% +within the framework of linear + + + align:start position:0% +within the framework of linear +differential equations I thought this + + align:start position:0% +differential equations I thought this + + + align:start position:0% +differential equations I thought this +would be a good time to introduce this + + align:start position:0% +would be a good time to introduce this + + + align:start position:0% +would be a good time to introduce this +rather important concept consequently + + align:start position:0% +rather important concept consequently + + + align:start position:0% +rather important concept consequently +our topic for today is called quite + + align:start position:0% +our topic for today is called quite + + + align:start position:0% +our topic for today is called quite +simply the llast transform and it hinges + + align:start position:0% +simply the llast transform and it hinges + + + align:start position:0% +simply the llast transform and it hinges +on the fact that e to the T goes to + + align:start position:0% +on the fact that e to the T goes to + + + align:start position:0% +on the fact that e to the T goes to +Infinity for as T approaches Infinity + + align:start position:0% +Infinity for as T approaches Infinity + + + align:start position:0% +Infinity for as T approaches Infinity +you see much more rapidly than most + + align:start position:0% +you see much more rapidly than most + + + align:start position:0% +you see much more rapidly than most +functions of T and by the way I say t + + align:start position:0% +functions of T and by the way I say t + + + align:start position:0% +functions of T and by the way I say t +here instead of X because theast + + align:start position:0% +here instead of X because theast + + + align:start position:0% +here instead of X because theast +transform was introduced primarily for + + align:start position:0% +transform was introduced primarily for + + + align:start position:0% +transform was introduced primarily for +differential equations in which the + + align:start position:0% +differential equations in which the + + + align:start position:0% +differential equations in which the +independent variable was time so + + align:start position:0% +independent variable was time so + + + align:start position:0% +independent variable was time so +traditionally one usually talks about F + + align:start position:0% +traditionally one usually talks about F + + + align:start position:0% +traditionally one usually talks about F +of T when one is talking about the + + align:start position:0% +of T when one is talking about the + + + align:start position:0% +of T when one is talking about the +transform uh Concepts but the entire + + align:start position:0% +transform uh Concepts but the entire + + + align:start position:0% +transform uh Concepts but the entire +idea is this remember as we saw in part + + align:start position:0% +idea is this remember as we saw in part + + + align:start position:0% +idea is this remember as we saw in part +one of our course that e to the T goes + + align:start position:0% +one of our course that e to the T goes + + + align:start position:0% +one of our course that e to the T goes +to Infinity much faster than t to the N + + align:start position:0% +to Infinity much faster than t to the N + + + align:start position:0% +to Infinity much faster than t to the N +for any integer n + + align:start position:0% +for any integer n + + + align:start position:0% +for any integer n +consequently what this means is since + + align:start position:0% +consequently what this means is since + + + align:start position:0% +consequently what this means is since +most functions can be represented in the + + align:start position:0% +most functions can be represented in the + + + align:start position:0% +most functions can be represented in the +power series one would expect that if + + align:start position:0% +power series one would expect that if + + + align:start position:0% +power series one would expect that if +one were to take a function like f of T + + align:start position:0% +one were to take a function like f of T + + + align:start position:0% +one were to take a function like f of T +and multiply it by e to the minus St + + align:start position:0% +and multiply it by e to the minus St + + + align:start position:0% +and multiply it by e to the minus St +where s was a constant greater than zero + + align:start position:0% +where s was a constant greater than zero + + + align:start position:0% +where s was a constant greater than zero +one would expect that e to Theus St F of + + align:start position:0% +one would expect that e to Theus St F of + + + align:start position:0% +one would expect that e to Theus St F of +T would approach zero rapidly as T + + align:start position:0% +T would approach zero rapidly as T + + + align:start position:0% +T would approach zero rapidly as T +approaches Infinity okay now this may + + align:start position:0% +approaches Infinity okay now this may + + + align:start position:0% +approaches Infinity okay now this may +not happen we'll talk about that in more + + align:start position:0% +not happen we'll talk about that in more + + + align:start position:0% +not happen we'll talk about that in more +detail later but at any rate let's + + align:start position:0% +detail later but at any rate let's + + + align:start position:0% +detail later but at any rate let's +assume that we're dealing with a + + align:start position:0% +assume that we're dealing with a + + + align:start position:0% +assume that we're dealing with a +particular function f of T where not + + align:start position:0% +particular function f of T where not + + + align:start position:0% +particular function f of T where not +only does e to Theus s of Ft F of T go + + align:start position:0% +only does e to Theus s of Ft F of T go + + + align:start position:0% +only does e to Theus s of Ft F of T go +to zero rapidly for some value of s as T + + align:start position:0% +to zero rapidly for some value of s as T + + + align:start position:0% +to zero rapidly for some value of s as T +approaches Infinity but so rapidly that + + align:start position:0% +approaches Infinity but so rapidly that + + + align:start position:0% +approaches Infinity but so rapidly that +the integral of e to Theus St F of T DT + + align:start position:0% +the integral of e to Theus St F of T DT + + + align:start position:0% +the integral of e to Theus St F of T DT +from 0er to Infinity converges let's + + align:start position:0% +from 0er to Infinity converges let's + + + align:start position:0% +from 0er to Infinity converges let's +just keep that in mind for the time + + align:start position:0% +just keep that in mind for the time + + + align:start position:0% +just keep that in mind for the time +being and with this in mind one defines + + align:start position:0% +being and with this in mind one defines + + + align:start position:0% +being and with this in mind one defines +the llast transform of a function f of T + + align:start position:0% +the llast transform of a function f of T + + + align:start position:0% +the llast transform of a function f of T +namely given F of t the llast transform + + align:start position:0% +namely given F of t the llast transform + + + align:start position:0% +namely given F of t the llast transform +of f of T written L of f of T is defined + + align:start position:0% +of f of T written L of f of T is defined + + + align:start position:0% +of f of T written L of f of T is defined +to be the integral from 0 to Infinity e + + align:start position:0% +to be the integral from 0 to Infinity e + + + align:start position:0% +to be the integral from 0 to Infinity e +the minus St F of T DT provided that + + align:start position:0% +the minus St F of T DT provided that + + + align:start position:0% +the minus St F of T DT provided that +this integral converges notice by the + + align:start position:0% +this integral converges notice by the + + + align:start position:0% +this integral converges notice by the +way that since T is the variable of + + align:start position:0% +way that since T is the variable of + + + align:start position:0% +way that since T is the variable of +integration when we evaluate this + + align:start position:0% +integration when we evaluate this + + + align:start position:0% +integration when we evaluate this +integral at tal 0 and tal + + align:start position:0% +integral at tal 0 and tal + + + align:start position:0% +integral at tal 0 and tal +Infinity the resulting function becomes + + align:start position:0% +Infinity the resulting function becomes + + + align:start position:0% +Infinity the resulting function becomes +a function of s alone in other words we + + align:start position:0% +a function of s alone in other words we + + + align:start position:0% +a function of s alone in other words we +evaluate this as T goes from 0 to + + align:start position:0% +evaluate this as T goes from 0 to + + + align:start position:0% +evaluate this as T goes from 0 to +Infinity the resulting integral is a + + align:start position:0% +Infinity the resulting integral is a + + + align:start position:0% +Infinity the resulting integral is a +function of s alone consequently one + + align:start position:0% +function of s alone consequently one + + + align:start position:0% +function of s alone consequently one +often to identify the function with its + + align:start position:0% +often to identify the function with its + + + align:start position:0% +often to identify the function with its +llast transform indicates that if the + + align:start position:0% +llast transform indicates that if the + + + align:start position:0% +llast transform indicates that if the +function was F of T the llast transform + + align:start position:0% +function was F of T the llast transform + + + align:start position:0% +function was F of T the llast transform +IS F Bar of s and notice by the way what + + align:start position:0% +IS F Bar of s and notice by the way what + + + align:start position:0% +IS F Bar of s and notice by the way what +this thing means pictorially this is an + + align:start position:0% +this thing means pictorially this is an + + + align:start position:0% +this thing means pictorially this is an +area under a curve and what you're + + align:start position:0% +area under a curve and what you're + + + align:start position:0% +area under a curve and what you're +really saying if the llast transform of + + align:start position:0% +really saying if the llast transform of + + + align:start position:0% +really saying if the llast transform of +a function exists is that this area + + align:start position:0% +a function exists is that this area + + + align:start position:0% +a function exists is that this area +under the curve as T goes from zero to + + align:start position:0% +under the curve as T goes from zero to + + + align:start position:0% +under the curve as T goes from zero to +Infinity is indeed finite by the way + + align:start position:0% +Infinity is indeed finite by the way + + + align:start position:0% +Infinity is indeed finite by the way +this should also lead you to believe + + align:start position:0% +this should also lead you to believe + + + align:start position:0% +this should also lead you to believe +that if this is finite for one value of + + align:start position:0% +that if this is finite for one value of + + + align:start position:0% +that if this is finite for one value of +s if s becomes is replaced by something + + align:start position:0% +s if s becomes is replaced by something + + + align:start position:0% +s if s becomes is replaced by something +larger this goes to zero even faster and + + align:start position:0% +larger this goes to zero even faster and + + + align:start position:0% +larger this goes to zero even faster and +consequently the uh area under the Curve + + align:start position:0% +consequently the uh area under the Curve + + + align:start position:0% +consequently the uh area under the Curve +will exist for all values of s Beyond a + + align:start position:0% +will exist for all values of s Beyond a + + + align:start position:0% +will exist for all values of s Beyond a +certain value once the area exists for + + align:start position:0% +certain value once the area exists for + + + align:start position:0% +certain value once the area exists for +that one value maybe the easiest way to + + align:start position:0% +that one value maybe the easiest way to + + + align:start position:0% +that one value maybe the easiest way to +say that is in terms of a picture here + + align:start position:0% +say that is in terms of a picture here + + + align:start position:0% +say that is in terms of a picture here +I've drawn two representative functions + + align:start position:0% +I've drawn two representative functions + + + align:start position:0% +I've drawn two representative functions +yal F of t one case being uh a pulsation + + align:start position:0% +yal F of t one case being uh a pulsation + + + align:start position:0% +yal F of t one case being uh a pulsation +type of thing where you have a an + + align:start position:0% +type of thing where you have a an + + + align:start position:0% +type of thing where you have a an +irregular pulse repeated here the other + + align:start position:0% +irregular pulse repeated here the other + + + align:start position:0% +irregular pulse repeated here the other +being a polinomial yal t ^2 what we're + + align:start position:0% +being a polinomial yal t ^2 what we're + + + align:start position:0% +being a polinomial yal t ^2 what we're +saying is that if I multiply F of T by e + + align:start position:0% +saying is that if I multiply F of T by e + + + align:start position:0% +saying is that if I multiply F of T by e +to the minus St remember e to the minus + + align:start position:0% +to the minus St remember e to the minus + + + align:start position:0% +to the minus St remember e to the minus +St for positive values of s is a curve + + align:start position:0% +St for positive values of s is a curve + + + align:start position:0% +St for positive values of s is a curve +that goes to zero very rapidly and what + + align:start position:0% +that goes to zero very rapidly and what + + + align:start position:0% +that goes to zero very rapidly and what +this tends to do is to pull this thing + + align:start position:0% +this tends to do is to pull this thing + + + align:start position:0% +this tends to do is to pull this thing +down so that you go to zero very rapidly + + align:start position:0% +down so that you go to zero very rapidly + + + align:start position:0% +down so that you go to zero very rapidly +and the fact that the integral exists + + align:start position:0% +and the fact that the integral exists + + + align:start position:0% +and the fact that the integral exists +says not only does this go to zero very + + align:start position:0% +says not only does this go to zero very + + + align:start position:0% +says not only does this go to zero very +rapidly but it goes to zero so fast that + + align:start position:0% +rapidly but it goes to zero so fast that + + + align:start position:0% +rapidly but it goes to zero so fast that +the area under the curve stays finite + + align:start position:0% +the area under the curve stays finite + + + align:start position:0% +the area under the curve stays finite +remember that was our version of + + align:start position:0% +remember that was our version of + + + align:start position:0% +remember that was our version of +infinity time Z it's not enough that + + align:start position:0% +infinity time Z it's not enough that + + + align:start position:0% +infinity time Z it's not enough that +this goes to zero that this approaches + + align:start position:0% +this goes to zero that this approaches + + + align:start position:0% +this goes to zero that this approaches +the T axis it has to approach fast + + align:start position:0% +the T axis it has to approach fast + + + align:start position:0% +the T axis it has to approach fast +enough so that the area under the curve + + align:start position:0% +enough so that the area under the curve + + + align:start position:0% +enough so that the area under the curve +is finite and all we're saying is that + + align:start position:0% +is finite and all we're saying is that + + + align:start position:0% +is finite and all we're saying is that +if you can find one value of s that + + align:start position:0% +if you can find one value of s that + + + align:start position:0% +if you can find one value of s that +makes the area under the Curve finite + + align:start position:0% +makes the area under the Curve finite + + + align:start position:0% +makes the area under the Curve finite +any larger value of s will certainly + + align:start position:0% +any larger value of s will certainly + + + align:start position:0% +any larger value of s will certainly +make the area under the curve finite + + align:start position:0% +make the area under the curve finite + + + align:start position:0% +make the area under the curve finite +because this will be pulled down even + + align:start position:0% +because this will be pulled down even + + + align:start position:0% +because this will be pulled down even +faster and perhaps you can begin to see + + align:start position:0% +faster and perhaps you can begin to see + + + align:start position:0% +faster and perhaps you can begin to see +intuitively that as I let s get larger + + align:start position:0% +intuitively that as I let s get larger + + + align:start position:0% +intuitively that as I let s get larger +and larger not only does the area under + + align:start position:0% +and larger not only does the area under + + + align:start position:0% +and larger not only does the area under +the curve stay finite but one would + + align:start position:0% +the curve stay finite but one would + + + align:start position:0% +the curve stay finite but one would +expect that it would also approach zero + + align:start position:0% +expect that it would also approach zero + + + align:start position:0% +expect that it would also approach zero +because for large values of s e to the + + align:start position:0% +because for large values of s e to the + + + align:start position:0% +because for large values of s e to the +minus St goes to zero so rapidly that + + align:start position:0% +minus St goes to zero so rapidly that + + + align:start position:0% +minus St goes to zero so rapidly that +even large values up here would be + + align:start position:0% +even large values up here would be + + + align:start position:0% +even large values up here would be +pulled down very rapidly at any rate let + + align:start position:0% +pulled down very rapidly at any rate let + + + align:start position:0% +pulled down very rapidly at any rate let +me illustrate this by means of an + + align:start position:0% +me illustrate this by means of an + + + align:start position:0% +me illustrate this by means of an +example suppose I pick for f of T + + align:start position:0% +example suppose I pick for f of T + + + align:start position:0% +example suppose I pick for f of T +something as simple as e to the a t + + align:start position:0% +something as simple as e to the a t + + + align:start position:0% +something as simple as e to the a t +where a is a given constant what I mean + + align:start position:0% +where a is a given constant what I mean + + + align:start position:0% +where a is a given constant what I mean +by simple here is recalling that that + + align:start position:0% +by simple here is recalling that that + + + align:start position:0% +by simple here is recalling that that +the llas transform involves multiplying + + align:start position:0% +the llas transform involves multiplying + + + align:start position:0% +the llas transform involves multiplying +F of T by e to the minus St this will + + align:start position:0% +F of T by e to the minus St this will + + + align:start position:0% +F of T by e to the minus St this will +give me a simple algebraic manipulation + + align:start position:0% +give me a simple algebraic manipulation + + + align:start position:0% +give me a simple algebraic manipulation +to perform by definition how do I form + + align:start position:0% +to perform by definition how do I form + + + align:start position:0% +to perform by definition how do I form +the llast transform of e to the a t what + + align:start position:0% +the llast transform of e to the a t what + + + align:start position:0% +the llast transform of e to the a t what +I do is I multiply e to the a t by e to + + align:start position:0% +I do is I multiply e to the a t by e to + + + align:start position:0% +I do is I multiply e to the a t by e to +the minus St and integrate that from 0 + + align:start position:0% +the minus St and integrate that from 0 + + + align:start position:0% +the minus St and integrate that from 0 +to infinity and if that integral exists + + align:start position:0% +to infinity and if that integral exists + + + align:start position:0% +to infinity and if that integral exists +meaning if the integral converges if + + align:start position:0% +meaning if the integral converges if + + + align:start position:0% +meaning if the integral converges if +this limit is finite I call that the + + align:start position:0% +this limit is finite I call that the + + + align:start position:0% +this limit is finite I call that the +llast transform at any rate just + + align:start position:0% +llast transform at any rate just + + + align:start position:0% +llast transform at any rate just +substituting in here then F of T becomes + + align:start position:0% +substituting in here then F of T becomes + + + align:start position:0% +substituting in here then F of T becomes +e to the a t this says integral from 0 + + align:start position:0% +e to the a t this says integral from 0 + + + align:start position:0% +e to the a t this says integral from 0 +to Infinity e to the a - s * T power DT + + align:start position:0% +to Infinity e to the a - s * T power DT + + + align:start position:0% +to Infinity e to the a - s * T power DT +since A and S are constants the integral + + align:start position:0% +since A and S are constants the integral + + + align:start position:0% +since A and S are constants the integral +e to the A- s t comes out to be 1 / A- s + + align:start position:0% +e to the A- s t comes out to be 1 / A- s + + + align:start position:0% +e to the A- s t comes out to be 1 / A- s +e to the a minus St evaluated as T goes + + align:start position:0% +e to the a minus St evaluated as T goes + + + align:start position:0% +e to the a minus St evaluated as T goes +from 0 to Infinity now the key point to + + align:start position:0% +from 0 to Infinity now the key point to + + + align:start position:0% +from 0 to Infinity now the key point to +notice here is that as soon as s is + + align:start position:0% +notice here is that as soon as s is + + + align:start position:0% +notice here is that as soon as s is +greater than a this gives me a negative + + align:start position:0% +greater than a this gives me a negative + + + align:start position:0% +greater than a this gives me a negative +exponent as soon as s is greater than a + + align:start position:0% +exponent as soon as s is greater than a + + + align:start position:0% +exponent as soon as s is greater than a +consequently as T goes to Infinity this + + align:start position:0% +consequently as T goes to Infinity this + + + align:start position:0% +consequently as T goes to Infinity this +essentially behaves like 1 over e to the + + align:start position:0% +essentially behaves like 1 over e to the + + + align:start position:0% +essentially behaves like 1 over e to the +infinity which is zero in other words + + align:start position:0% +infinity which is zero in other words + + + align:start position:0% +infinity which is zero in other words +once s is greater than a the upper limit + + align:start position:0% +once s is greater than a the upper limit + + + align:start position:0% +once s is greater than a the upper limit +drops out my lower limit would just be e + + align:start position:0% +drops out my lower limit would just be e + + + align:start position:0% +drops out my lower limit would just be e +to the 0 you see and I'm subtracting + + align:start position:0% +to the 0 you see and I'm subtracting + + + align:start position:0% +to the 0 you see and I'm subtracting +that at any rate to make a long story + + align:start position:0% +that at any rate to make a long story + + + align:start position:0% +that at any rate to make a long story +short and to summarize what we're saying + + align:start position:0% +short and to summarize what we're saying + + + align:start position:0% +short and to summarize what we're saying +simply observe that if s is greater than + + align:start position:0% +simply observe that if s is greater than + + + align:start position:0% +simply observe that if s is greater than +zero the limit as T approaches Infinity + + align:start position:0% +zero the limit as T approaches Infinity + + + align:start position:0% +zero the limit as T approaches Infinity +e to the a minus St T is zero and that + + align:start position:0% +e to the a minus St T is zero and that + + + align:start position:0% +e to the a minus St T is zero and that +therefore the llast transform of e to + + align:start position:0% +therefore the llast transform of e to + + + align:start position:0% +therefore the llast transform of e to +the a t is simply 1 / s minus a provided + + align:start position:0% +the a t is simply 1 / s minus a provided + + + align:start position:0% +the a t is simply 1 / s minus a provided +s is greater than a in other words again + + align:start position:0% +s is greater than a in other words again + + + align:start position:0% +s is greater than a in other words again +just looking back here see I subtract + + align:start position:0% +just looking back here see I subtract + + + align:start position:0% +just looking back here see I subtract +the lower limit when T is zero this is + + align:start position:0% +the lower limit when T is zero this is + + + align:start position:0% +the lower limit when T is zero this is +one but I'm subtracting it makes it + + align:start position:0% +one but I'm subtracting it makes it + + + align:start position:0% +one but I'm subtracting it makes it +minus one and - 1 / a - s is the same as + + align:start position:0% +minus one and - 1 / a - s is the same as + + + align:start position:0% +minus one and - 1 / a - s is the same as +1 / s - A to State this then in other + + align:start position:0% +1 / s - A to State this then in other + + + align:start position:0% +1 / s - A to State this then in other +words if F of T is e to the a t f bar of + + align:start position:0% +words if F of T is e to the a t f bar of + + + align:start position:0% +words if F of T is e to the a t f bar of +s is 1 / s minus a where the domain of f + + align:start position:0% +s is 1 / s minus a where the domain of f + + + align:start position:0% +s is 1 / s minus a where the domain of f +is a set of all s such that s is greater + + align:start position:0% +is a set of all s such that s is greater + + + align:start position:0% +is a set of all s such that s is greater +than a and what does this mean + + align:start position:0% +than a and what does this mean + + + align:start position:0% +than a and what does this mean +geometrically this is the area under the + + align:start position:0% +geometrically this is the area under the + + + align:start position:0% +geometrically this is the area under the +curve e to the minus st e to the a t as + + align:start position:0% +curve e to the minus st e to the a t as + + + align:start position:0% +curve e to the minus st e to the a t as +T goes from 0 to Infinity that that area + + align:start position:0% +T goes from 0 to Infinity that that area + + + align:start position:0% +T goes from 0 to Infinity that that area +will be finite as soon as s is greater + + align:start position:0% +will be finite as soon as s is greater + + + align:start position:0% +will be finite as soon as s is greater +than a by way of illustration if I + + align:start position:0% +than a by way of illustration if I + + + align:start position:0% +than a by way of illustration if I +replace a by two what we're saying is + + align:start position:0% +replace a by two what we're saying is + + + align:start position:0% +replace a by two what we're saying is +that the llast transform of e 2T is 1 / + + align:start position:0% +that the llast transform of e 2T is 1 / + + + align:start position:0% +that the llast transform of e 2T is 1 / +s minus 2 notice that nice polinomial + + align:start position:0% +s minus 2 notice that nice polinomial + + + align:start position:0% +s minus 2 notice that nice polinomial +quotient idea the rather simple + + align:start position:0% +quotient idea the rather simple + + + align:start position:0% +quotient idea the rather simple +expression 1 / s - 2 if s is greater + + align:start position:0% +expression 1 / s - 2 if s is greater + + + align:start position:0% +expression 1 / s - 2 if s is greater +than two if we replace a by minus 3 and + + align:start position:0% +than two if we replace a by minus 3 and + + + align:start position:0% +than two if we replace a by minus 3 and +use this recipe we have that the llas + + align:start position:0% +use this recipe we have that the llas + + + align:start position:0% +use this recipe we have that the llas +transform of eus 3T is 1 / s - -3 1 / s + + align:start position:0% +transform of eus 3T is 1 / s - -3 1 / s + + + align:start position:0% +transform of eus 3T is 1 / s - -3 1 / s ++ 3 where s must be greater than -3 + + align:start position:0% ++ 3 where s must be greater than -3 + + + align:start position:0% ++ 3 where s must be greater than -3 +notice also here that by the comparison + + align:start position:0% +notice also here that by the comparison + + + align:start position:0% +notice also here that by the comparison +test so to speak remember the same + + align:start position:0% +test so to speak remember the same + + + align:start position:0% +test so to speak remember the same +comparison test that we use for infinite + + align:start position:0% +comparison test that we use for infinite + + + align:start position:0% +comparison test that we use for infinite +series if the magnitude of f of T is + + align:start position:0% +series if the magnitude of f of T is + + + align:start position:0% +series if the magnitude of f of T is +less than some constant C * e to the a t + + align:start position:0% +less than some constant C * e to the a t + + + align:start position:0% +less than some constant C * e to the a t +power for all values of T then the + + align:start position:0% +power for all values of T then the + + + align:start position:0% +power for all values of T then the +integral from 0 to Infinity e to Theus + + align:start position:0% +integral from 0 to Infinity e to Theus + + + align:start position:0% +integral from 0 to Infinity e to Theus +St F of T DT must also converge in other + + align:start position:0% +St F of T DT must also converge in other + + + align:start position:0% +St F of T DT must also converge in other +words we are already know that this + + align:start position:0% +words we are already know that this + + + align:start position:0% +words we are already know that this +integral converges shall we say if the + + align:start position:0% +integral converges shall we say if the + + + align:start position:0% +integral converges shall we say if the +integran were e to the a t right + + align:start position:0% +integran were e to the a t right + + + align:start position:0% +integran were e to the a t right +therefore we're saying it'll converge if + + align:start position:0% +therefore we're saying it'll converge if + + + align:start position:0% +therefore we're saying it'll converge if +you multiply that by a constant because + + align:start position:0% +you multiply that by a constant because + + + align:start position:0% +you multiply that by a constant because +convergence isn't affected by + + align:start position:0% +convergence isn't affected by + + + align:start position:0% +convergence isn't affected by +multiplying by a constant consequently + + align:start position:0% +multiplying by a constant consequently + + + align:start position:0% +multiplying by a constant consequently +if in magnitude the integrant that we're + + align:start position:0% +if in magnitude the integrant that we're + + + align:start position:0% +if in magnitude the integrant that we're +investigating is smaller than this in + + align:start position:0% +investigating is smaller than this in + + + align:start position:0% +investigating is smaller than this in +magnitude it must also have a the plus + + align:start position:0% +magnitude it must also have a the plus + + + align:start position:0% +magnitude it must also have a the plus +transform that this thing here must + + align:start position:0% +transform that this thing here must + + + align:start position:0% +transform that this thing here must +converge now because this is so obvious + + align:start position:0% +converge now because this is so obvious + + + align:start position:0% +converge now because this is so obvious +and so important one defines a function + + align:start position:0% +and so important one defines a function + + + align:start position:0% +and so important one defines a function +with this property to have a very + + align:start position:0% +with this property to have a very + + + align:start position:0% +with this property to have a very +special name namely the function f of T + + align:start position:0% +special name namely the function f of T + + + align:start position:0% +special name namely the function f of T +is set to have exponential order if and + + align:start position:0% +is set to have exponential order if and + + + align:start position:0% +is set to have exponential order if and +only if there exists constant c and a + + align:start position:0% +only if there exists constant c and a + + + align:start position:0% +only if there exists constant c and a +such that the magnitude of f of T is + + align:start position:0% +such that the magnitude of f of T is + + + align:start position:0% +such that the magnitude of f of T is +less than c e to the a t for T all T + + align:start position:0% +less than c e to the a t for T all T + + + align:start position:0% +less than c e to the a t for T all T +greater than zero what we are saying in + + align:start position:0% +greater than zero what we are saying in + + + align:start position:0% +greater than zero what we are saying in +summary is that by this definition of + + align:start position:0% +summary is that by this definition of + + + align:start position:0% +summary is that by this definition of +exponential order and the comparison + + align:start position:0% +exponential order and the comparison + + + align:start position:0% +exponential order and the comparison +test all functions of exponential order + + align:start position:0% +test all functions of exponential order + + + align:start position:0% +test all functions of exponential order +have llast transforms because that + + align:start position:0% +have llast transforms because that + + + align:start position:0% +have llast transforms because that +integral from 0 to Infinity e to the + + align:start position:0% +integral from 0 to Infinity e to the + + + align:start position:0% +integral from 0 to Infinity e to the +minus St F of T DT will converge by + + align:start position:0% +minus St F of T DT will converge by + + + align:start position:0% +minus St F of T DT will converge by +comparison with the integral 0 to + + align:start position:0% +comparison with the integral 0 to + + + align:start position:0% +comparison with the integral 0 to +Infinity e to the minus st e the a tdt + + align:start position:0% +Infinity e to the minus st e the a tdt + + + align:start position:0% +Infinity e to the minus st e the a tdt +for S greater than in other words this + + align:start position:0% +for S greater than in other words this + + + align:start position:0% +for S greater than in other words this +will all converge where the value of s + + align:start position:0% +will all converge where the value of s + + + align:start position:0% +will all converge where the value of s +has to be greater than a now the idea is + + align:start position:0% +has to be greater than a now the idea is + + + align:start position:0% +has to be greater than a now the idea is +what's so important about functions of + + align:start position:0% +what's so important about functions of + + + align:start position:0% +what's so important about functions of +exponential order why do I stress these + + align:start position:0% +exponential order why do I stress these + + + align:start position:0% +exponential order why do I stress these +and the answer is that in terms of + + align:start position:0% +and the answer is that in terms of + + + align:start position:0% +and the answer is that in terms of +linear differential equations with + + align:start position:0% +linear differential equations with + + + align:start position:0% +linear differential equations with +constant + + align:start position:0% +constant + + + align:start position:0% +constant +coefficients the functions that we tend + + align:start position:0% +coefficients the functions that we tend + + + align:start position:0% +coefficients the functions that we tend +to deal with all have exponential order + + align:start position:0% +to deal with all have exponential order + + + align:start position:0% +to deal with all have exponential order +in other words they will all have llast + + align:start position:0% +in other words they will all have llast + + + align:start position:0% +in other words they will all have llast +transforms for example e to the a t + + align:start position:0% +transforms for example e to the a t + + + align:start position:0% +transforms for example e to the a t +trivially is a function uh that has + + align:start position:0% +trivially is a function uh that has + + + align:start position:0% +trivially is a function uh that has +exponential order that was our model for + + align:start position:0% +exponential order that was our model for + + + align:start position:0% +exponential order that was our model for +the definition in fact e to the a t is 1 + + align:start position:0% +the definition in fact e to the a t is 1 + + + align:start position:0% +the definition in fact e to the a t is 1 +e to the a t simply take a to be a and C + + align:start position:0% +e to the a t simply take a to be a and C + + + align:start position:0% +e to the a t simply take a to be a and C +to be one and we have the Criterion for + + align:start position:0% +to be one and we have the Criterion for + + + align:start position:0% +to be one and we have the Criterion for +exponential order being obeyed the sign + + align:start position:0% +exponential order being obeyed the sign + + + align:start position:0% +exponential order being obeyed the sign +of a t where a is any constant has + + align:start position:0% +of a t where a is any constant has + + + align:start position:0% +of a t where a is any constant has +exponential order why because the + + align:start position:0% +exponential order why because the + + + align:start position:0% +exponential order why because the +magnitude of sin a t is certainly no + + align:start position:0% +magnitude of sin a t is certainly no + + + align:start position:0% +magnitude of sin a t is certainly no +greater than one and one is certainly no + + align:start position:0% +greater than one and one is certainly no + + + align:start position:0% +greater than one and one is certainly no +greater than e to the T for any positive + + align:start position:0% +greater than e to the T for any positive + + + align:start position:0% +greater than e to the T for any positive +value of T see e to the 0 is already one + + align:start position:0% +value of T see e to the 0 is already one + + + align:start position:0% +value of T see e to the 0 is already one +therefore sin a t is less than 1 e to + + align:start position:0% +therefore sin a t is less than 1 e to + + + align:start position:0% +therefore sin a t is less than 1 e to +the 1 T if T is greater than zero so sin + + align:start position:0% +the 1 T if T is greater than zero so sin + + + align:start position:0% +the 1 T if T is greater than zero so sin +a t has exponential order finally we + + align:start position:0% +a t has exponential order finally we + + + align:start position:0% +a t has exponential order finally we +dealt with polinomial t to the N where n + + align:start position:0% +dealt with polinomial t to the N where n + + + align:start position:0% +dealt with polinomial t to the N where n +was a positive integer and in part one + + align:start position:0% +was a positive integer and in part one + + + align:start position:0% +was a positive integer and in part one +of our course either using lopital rule + + align:start position:0% +of our course either using lopital rule + + + align:start position:0% +of our course either using lopital rule +or power series or what have you we + + align:start position:0% +or power series or what have you we + + + align:start position:0% +or power series or what have you we +showed that for any fixed positive + + align:start position:0% +showed that for any fixed positive + + + align:start position:0% +showed that for any fixed positive +integer n t the n * eus T went to zero + + align:start position:0% +integer n t the n * eus T went to zero + + + align:start position:0% +integer n t the n * eus T went to zero +in the limit as T went to Infinity + + align:start position:0% +in the limit as T went to Infinity + + + align:start position:0% +in the limit as T went to Infinity +consequently for large values of T the + + align:start position:0% +consequently for large values of T the + + + align:start position:0% +consequently for large values of T the +magnitude of t to the N is less than e + + align:start position:0% +magnitude of t to the N is less than e + + + align:start position:0% +magnitude of t to the N is less than e +to the T I'll leave the details out here + + align:start position:0% +to the T I'll leave the details out here + + + align:start position:0% +to the T I'll leave the details out here +I'm just trying to illustrate what's + + align:start position:0% +I'm just trying to illustrate what's + + + align:start position:0% +I'm just trying to illustrate what's +going on the important point is that the + + align:start position:0% +going on the important point is that the + + + align:start position:0% +going on the important point is that the +usual functions in counted in linear + + align:start position:0% +usual functions in counted in linear + + + align:start position:0% +usual functions in counted in linear +differential equations with coefficients + + align:start position:0% +differential equations with coefficients + + + align:start position:0% +differential equations with coefficients +have the + + align:start position:0% +have the + + + align:start position:0% +have the +transforms and I would like to make a + + align:start position:0% +transforms and I would like to make a + + + align:start position:0% +transforms and I would like to make a +couple of notes about this thing one + + align:start position:0% +couple of notes about this thing one + + + align:start position:0% +couple of notes about this thing one +I've already said but I'd like to + + align:start position:0% +I've already said but I'd like to + + + align:start position:0% +I've already said but I'd like to +reinforce + + align:start position:0% +reinforce + + + align:start position:0% +reinforce +it the what we've already seen is is + + align:start position:0% +it the what we've already seen is is + + + align:start position:0% +it the what we've already seen is is +that if F has exponential order F Bar of + + align:start position:0% +that if F has exponential order F Bar of + + + align:start position:0% +that if F has exponential order F Bar of +s the llast transform of s must be less + + align:start position:0% +s the llast transform of s must be less + + + align:start position:0% +s the llast transform of s must be less +than or equal to the llast transform of + + align:start position:0% +than or equal to the llast transform of + + + align:start position:0% +than or equal to the llast transform of +e to the well a constant times e to the + + align:start position:0% +e to the well a constant times e to the + + + align:start position:0% +e to the well a constant times e to the +a t but that the llast transform of e to + + align:start position:0% +a t but that the llast transform of e to + + + align:start position:0% +a t but that the llast transform of e to +the a t is 1 / s minus a so the class + + align:start position:0% +the a t is 1 / s minus a so the class + + + align:start position:0% +the a t is 1 / s minus a so the class +transform of f of f of f of T if F has + + align:start position:0% +transform of f of f of f of T if F has + + + align:start position:0% +transform of f of f of f of T if F has +exponential order can be no bigger than + + align:start position:0% +exponential order can be no bigger than + + + align:start position:0% +exponential order can be no bigger than +c/ S minus a since C is a constant and a + + align:start position:0% +c/ S minus a since C is a constant and a + + + align:start position:0% +c/ S minus a since C is a constant and a +is a constant as s goes to Infinity fbar + + align:start position:0% +is a constant as s goes to Infinity fbar + + + align:start position:0% +is a constant as s goes to Infinity fbar +of s goes to zero in other words for + + align:start position:0% +of s goes to zero in other words for + + + align:start position:0% +of s goes to zero in other words for +sufficiently large values of s the llast + + align:start position:0% +sufficiently large values of s the llast + + + align:start position:0% +sufficiently large values of s the llast +transform which names an area under a + + align:start position:0% +transform which names an area under a + + + align:start position:0% +transform which names an area under a +curve goes to zero meaning as we would + + align:start position:0% +curve goes to zero meaning as we would + + + align:start position:0% +curve goes to zero meaning as we would +expect the area under the curve does go + + align:start position:0% +expect the area under the curve does go + + + align:start position:0% +expect the area under the curve does go +to zero as s increases without bound + + align:start position:0% +to zero as s increases without bound + + + align:start position:0% +to zero as s increases without bound +what that means in particular you see is + + align:start position:0% +what that means in particular you see is + + + align:start position:0% +what that means in particular you see is +that not any function can be a llast + + align:start position:0% +that not any function can be a llast + + + align:start position:0% +that not any function can be a llast +transform of something you see in + + align:start position:0% +transform of something you see in + + + align:start position:0% +transform of something you see in +particular this says that for F Bar to + + align:start position:0% +particular this says that for F Bar to + + + align:start position:0% +particular this says that for F Bar to +be the llast transform of something F + + align:start position:0% +be the llast transform of something F + + + align:start position:0% +be the llast transform of something F +Bar of s must go to zero as s goes to + + align:start position:0% +Bar of s must go to zero as s goes to + + + align:start position:0% +Bar of s must go to zero as s goes to +Infinity for example if I were to write + + align:start position:0% +Infinity for example if I were to write + + + align:start position:0% +Infinity for example if I were to write +down F Bar of s to be S over s minus one + + align:start position:0% +down F Bar of s to be S over s minus one + + + align:start position:0% +down F Bar of s to be S over s minus one +or s+ one even F Bar of s is s over s + + + align:start position:0% +or s+ one even F Bar of s is s over s + + + + align:start position:0% +or s+ one even F Bar of s is s over s + +one notice that the limit of F Bar of s + + align:start position:0% +one notice that the limit of F Bar of s + + + align:start position:0% +one notice that the limit of F Bar of s +as s goes to Infinity is one con + + align:start position:0% +as s goes to Infinity is one con + + + align:start position:0% +as s goes to Infinity is one con +consequently this F Bar cannot be the + + align:start position:0% +consequently this F Bar cannot be the + + + align:start position:0% +consequently this F Bar cannot be the +llas transform of any function at least + + align:start position:0% +llas transform of any function at least + + + align:start position:0% +llas transform of any function at least +of exponential order because we've + + align:start position:0% +of exponential order because we've + + + align:start position:0% +of exponential order because we've +already seen that the llast transform of + + align:start position:0% +already seen that the llast transform of + + + align:start position:0% +already seen that the llast transform of +a function uh at least of exponential + + align:start position:0% +a function uh at least of exponential + + + align:start position:0% +a function uh at least of exponential +order must go to zero as s goes to + + align:start position:0% +order must go to zero as s goes to + + + align:start position:0% +order must go to zero as s goes to +Infinity okay so not every function can + + align:start position:0% +Infinity okay so not every function can + + + align:start position:0% +Infinity okay so not every function can +be a lli transform of something and + + align:start position:0% +be a lli transform of something and + + + align:start position:0% +be a lli transform of something and +secondly not every function has + + align:start position:0% +secondly not every function has + + + align:start position:0% +secondly not every function has +exponential order it may be true as we + + align:start position:0% +exponential order it may be true as we + + + align:start position:0% +exponential order it may be true as we +just showed that every function that + + align:start position:0% +just showed that every function that + + + align:start position:0% +just showed that every function that +we're dealing with when we're dealing + + align:start position:0% +we're dealing with when we're dealing + + + align:start position:0% +we're dealing with when we're dealing +with linear differ equations with + + align:start position:0% +with linear differ equations with + + + align:start position:0% +with linear differ equations with +constant coefficients or most functions + + align:start position:0% +constant coefficients or most functions + + + align:start position:0% +constant coefficients or most functions +that we're dealing with with linear + + align:start position:0% +that we're dealing with with linear + + + align:start position:0% +that we're dealing with with linear +differential equations with constant + + align:start position:0% +differential equations with constant + + + align:start position:0% +differential equations with constant +coefficients has our functions of + + align:start position:0% +coefficients has our functions of + + + align:start position:0% +coefficients has our functions of +exponential order not all functions have + + align:start position:0% +exponential order not all functions have + + + align:start position:0% +exponential order not all functions have +exponential order for example e to the + + align:start position:0% +exponential order for example e to the + + + align:start position:0% +exponential order for example e to the +t^2 does not have exponential order not + + align:start position:0% +t^2 does not have exponential order not + + + align:start position:0% +t^2 does not have exponential order not +order order + + align:start position:0% +order order + + + align:start position:0% +order order +order since notice that e to the t^2 + + align:start position:0% +order since notice that e to the t^2 + + + align:start position:0% +order since notice that e to the t^2 +divided by c e to the a t would be 1 / c + + align:start position:0% +divided by c e to the a t would be 1 / c + + + align:start position:0% +divided by c e to the a t would be 1 / c +e to the T ^2 minus a t which is T * T + + align:start position:0% +e to the T ^2 minus a t which is T * T + + + align:start position:0% +e to the T ^2 minus a t which is T * T +minus a and notice now that if T is + + align:start position:0% +minus a and notice now that if T is + + + align:start position:0% +minus a and notice now that if T is +greater than a this exponent will be + + align:start position:0% +greater than a this exponent will be + + + align:start position:0% +greater than a this exponent will be +positive and as T goes to Infinity you + + align:start position:0% +positive and as T goes to Infinity you + + + align:start position:0% +positive and as T goes to Infinity you +see once T is greater than a this thing + + align:start position:0% +see once T is greater than a this thing + + + align:start position:0% +see once T is greater than a this thing +increases without bound and consequently + + align:start position:0% +increases without bound and consequently + + + align:start position:0% +increases without bound and consequently +since C is a constant you essentially + + align:start position:0% +since C is a constant you essentially + + + align:start position:0% +since C is a constant you essentially +have Infinity divided by a non-zero + + align:start position:0% +have Infinity divided by a non-zero + + + align:start position:0% +have Infinity divided by a non-zero +constant so you have what that e to the + + align:start position:0% +constant so you have what that e to the + + + align:start position:0% +constant so you have what that e to the +t^2 over C to the a t goes to Infinity + + align:start position:0% +t^2 over C to the a t goes to Infinity + + + align:start position:0% +t^2 over C to the a t goes to Infinity +as T approaches Infinity in particular + + align:start position:0% +as T approaches Infinity in particular + + + align:start position:0% +as T approaches Infinity in particular +this says that e to the t^ 2 dwarfs c e + + align:start position:0% +this says that e to the t^ 2 dwarfs c e + + + align:start position:0% +this says that e to the t^ 2 dwarfs c e +to the a t for large values of T other + + align:start position:0% +to the a t for large values of T other + + + align:start position:0% +to the a t for large values of T other +in particular you cannot have that uh e + + align:start position:0% +in particular you cannot have that uh e + + + align:start position:0% +in particular you cannot have that uh e +to the T ^ 2 is less than some constant + + align:start position:0% +to the T ^ 2 is less than some constant + + + align:start position:0% +to the T ^ 2 is less than some constant +time e to the a t now the question that + + align:start position:0% +time e to the a t now the question that + + + align:start position:0% +time e to the a t now the question that +comes up is what's so important now + + align:start position:0% +comes up is what's so important now + + + align:start position:0% +comes up is what's so important now +about the llast transform in terms of + + align:start position:0% +about the llast transform in terms of + + + align:start position:0% +about the llast transform in terms of +linear differential equations + + align:start position:0% +linear differential equations + + + align:start position:0% +linear differential equations +and the the answer is that the llast + + align:start position:0% +and the the answer is that the llast + + + align:start position:0% +and the the answer is that the llast +transform amazing enough has properties + + align:start position:0% +transform amazing enough has properties + + + align:start position:0% +transform amazing enough has properties +of linearity what do you mean by + + align:start position:0% +of linearity what do you mean by + + + align:start position:0% +of linearity what do you mean by +properties of linearity you mean what + + align:start position:0% +properties of linearity you mean what + + + align:start position:0% +properties of linearity you mean what +that for a function to be + + align:start position:0% +that for a function to be + + + align:start position:0% +that for a function to be +linear L of a sum must be the sum of the + + align:start position:0% +linear L of a sum must be the sum of the + + + align:start position:0% +linear L of a sum must be the sum of the +L's and L of a constant time something + + align:start position:0% +L's and L of a constant time something + + + align:start position:0% +L's and L of a constant time something +must be the constant times L of + + align:start position:0% +must be the constant times L of + + + align:start position:0% +must be the constant times L of +something well look at when you're + + align:start position:0% +something well look at when you're + + + align:start position:0% +something well look at when you're +dealing with + + align:start position:0% +dealing with + + + align:start position:0% +dealing with +integrals the given two definite + + align:start position:0% +integrals the given two definite + + + align:start position:0% +integrals the given two definite +integrals which exist the sum of the + + align:start position:0% +integrals which exist the sum of the + + + align:start position:0% +integrals which exist the sum of the +integrals is the integral of the sum the + + align:start position:0% +integrals is the integral of the sum the + + + align:start position:0% +integrals is the integral of the sum the +integral of a constant times an + + align:start position:0% +integral of a constant times an + + + align:start position:0% +integral of a constant times an +integrand is a constant times the + + align:start position:0% +integrand is a constant times the + + + align:start position:0% +integrand is a constant times the +integral of the integrand itself in + + align:start position:0% +integral of the integrand itself in + + + align:start position:0% +integral of the integrand itself in +other words sparing you the details + + align:start position:0% +other words sparing you the details + + + align:start position:0% +other words sparing you the details +because they follow right from the + + align:start position:0% +because they follow right from the + + + align:start position:0% +because they follow right from the +definition and that is assuming that f + + align:start position:0% +definition and that is assuming that f + + + align:start position:0% +definition and that is assuming that f +and g have llas transforms in other + + align:start position:0% +and g have llas transforms in other + + + align:start position:0% +and g have llas transforms in other +words that that improper integral from + + align:start position:0% +words that that improper integral from + + + align:start position:0% +words that that improper integral from +zero to Infinity e to the minus St F of + + align:start position:0% +zero to Infinity e to the minus St F of + + + align:start position:0% +zero to Infinity e to the minus St F of +T DT converges then what's true is that + + align:start position:0% +T DT converges then what's true is that + + + align:start position:0% +T DT converges then what's true is that +L of f+ G is L of f plus L of G and L of + + align:start position:0% +L of f+ G is L of f plus L of G and L of + + + align:start position:0% +L of f+ G is L of f plus L of G and L of +C * f is C * L of f see the linearity + + align:start position:0% +C * f is C * L of f see the linearity + + + align:start position:0% +C * f is C * L of f see the linearity +properties now how does that help us and + + align:start position:0% +properties now how does that help us and + + + align:start position:0% +properties now how does that help us and +why does that give us a hint that there + + align:start position:0% +why does that give us a hint that there + + + align:start position:0% +why does that give us a hint that there +will be some usage of the llast + + align:start position:0% +will be some usage of the llast + + + align:start position:0% +will be some usage of the llast +transform in solving linear differential + + align:start position:0% +transform in solving linear differential + + + align:start position:0% +transform in solving linear differential +equations with constant coefficients + + align:start position:0% +equations with constant coefficients + + + align:start position:0% +equations with constant coefficients +well perhaps the best way to see this is + + align:start position:0% +well perhaps the best way to see this is + + + align:start position:0% +well perhaps the best way to see this is +by means of an illustration let's assume + + align:start position:0% +by means of an illustration let's assume + + + align:start position:0% +by means of an illustration let's assume +that we're given that Y is a twice + + align:start position:0% +that we're given that Y is a twice + + + align:start position:0% +that we're given that Y is a twice +differentiable function of T and that y + + align:start position:0% +differentiable function of T and that y + + + align:start position:0% +differentiable function of T and that y +prime plus 2 a y prime plus b y where A + + align:start position:0% +prime plus 2 a y prime plus b y where A + + + align:start position:0% +prime plus 2 a y prime plus b y where A +and B are constants is some function f + + align:start position:0% +and B are constants is some function f + + + align:start position:0% +and B are constants is some function f +of t + + align:start position:0% +of t + + + align:start position:0% +of t +the idea is this I simply take the llast + + align:start position:0% +the idea is this I simply take the llast + + + align:start position:0% +the idea is this I simply take the llast +transform of both + + align:start position:0% +transform of both + + + align:start position:0% +transform of both +sides + + align:start position:0% +sides + + + align:start position:0% +sides +see by linearity since the laast + + align:start position:0% +see by linearity since the laast + + + align:start position:0% +see by linearity since the laast +transform is a linear function a linear + + align:start position:0% +transform is a linear function a linear + + + align:start position:0% +transform is a linear function a linear +operator L of Y Prime + 2 a y prime plus + + align:start position:0% +operator L of Y Prime + 2 a y prime plus + + + align:start position:0% +operator L of Y Prime + 2 a y prime plus +b y is simply L of Y prime plus 2 a l of + + align:start position:0% +b y is simply L of Y prime plus 2 a l of + + + align:start position:0% +b y is simply L of Y prime plus 2 a l of +Y prime plus b l of Y and the llast + + align:start position:0% +Y prime plus b l of Y and the llast + + + align:start position:0% +Y prime plus b l of Y and the llast +transform of f of T assuming that F of T + + align:start position:0% +transform of f of T assuming that F of T + + + align:start position:0% +transform of f of T assuming that F of T +has a llast transform and in particular + + align:start position:0% +has a llast transform and in particular + + + align:start position:0% +has a llast transform and in particular +if f F of T happens to be a function of + + align:start position:0% +if f F of T happens to be a function of + + + align:start position:0% +if f F of T happens to be a function of +exponential order we've already seen it + + align:start position:0% +exponential order we've already seen it + + + align:start position:0% +exponential order we've already seen it +it will have a llast transform all we're + + align:start position:0% +it will have a llast transform all we're + + + align:start position:0% +it will have a llast transform all we're +saying is let's call the llast transform + + align:start position:0% +saying is let's call the llast transform + + + align:start position:0% +saying is let's call the llast transform +of f of t as usual fbar of s and now + + align:start position:0% +of f of t as usual fbar of s and now + + + align:start position:0% +of f of t as usual fbar of s and now +what we have is an equation involving + + align:start position:0% +what we have is an equation involving + + + align:start position:0% +what we have is an equation involving +theast transform of Y the llast + + align:start position:0% +theast transform of Y the llast + + + align:start position:0% +theast transform of Y the llast +transform of Y Prime the llast transform + + align:start position:0% +transform of Y Prime the llast transform + + + align:start position:0% +transform of Y Prime the llast transform +of Y dble Prime in terms of F Bar of s + + align:start position:0% +of Y dble Prime in terms of F Bar of s + + + align:start position:0% +of Y dble Prime in terms of F Bar of s +if somehow we could manipulate this to + + align:start position:0% +if somehow we could manipulate this to + + + align:start position:0% +if somehow we could manipulate this to +solve for L of Y in other words if we + + align:start position:0% +solve for L of Y in other words if we + + + align:start position:0% +solve for L of Y in other words if we +could find what theast transform of Y + + align:start position:0% +could find what theast transform of Y + + + align:start position:0% +could find what theast transform of Y +was in terms of s maybe we could then + + align:start position:0% +was in terms of s maybe we could then + + + align:start position:0% +was in terms of s maybe we could then +invert so to speak and find out what the + + align:start position:0% +invert so to speak and find out what the + + + align:start position:0% +invert so to speak and find out what the +function itself must have been in other + + align:start position:0% +function itself must have been in other + + + align:start position:0% +function itself must have been in other +words the the idea of inverse functions + + align:start position:0% +words the the idea of inverse functions + + + align:start position:0% +words the the idea of inverse functions +comes up the same way here as it comes + + align:start position:0% +comes up the same way here as it comes + + + align:start position:0% +comes up the same way here as it comes +up every place namely starting with a + + align:start position:0% +up every place namely starting with a + + + align:start position:0% +up every place namely starting with a +function that Maps X into y one often + + align:start position:0% +function that Maps X into y one often + + + align:start position:0% +function that Maps X into y one often +says if I know what Y is can I determine + + align:start position:0% +says if I know what Y is can I determine + + + align:start position:0% +says if I know what Y is can I determine +what x must have been and that's why one + + align:start position:0% +what x must have been and that's why one + + + align:start position:0% +what x must have been and that's why one +to Oneness is so important in other + + align:start position:0% +to Oneness is so important in other + + + align:start position:0% +to Oneness is so important in other +words if it turns out that the llast + + align:start position:0% +words if it turns out that the llast + + + align:start position:0% +words if it turns out that the llast +transform is one: one + + align:start position:0% +transform is one: one + + + align:start position:0% +transform is one: one +once I know theast transform I + + align:start position:0% +once I know theast transform I + + + align:start position:0% +once I know theast transform I +essentially know the function because if + + align:start position:0% +essentially know the function because if + + + align:start position:0% +essentially know the function because if +two different functions can't have the + + align:start position:0% +two different functions can't have the + + + align:start position:0% +two different functions can't have the +same replast transform and by the way as + + align:start position:0% +same replast transform and by the way as + + + align:start position:0% +same replast transform and by the way as +a finale for today's lecture we will + + align:start position:0% +a finale for today's lecture we will + + + align:start position:0% +a finale for today's lecture we will +show that this is essentially the case + + align:start position:0% +show that this is essentially the case + + + align:start position:0% +show that this is essentially the case +that the llast transform is one to one + + align:start position:0% +that the llast transform is one to one + + + align:start position:0% +that the llast transform is one to one +and what I mean by essentially will be + + align:start position:0% +and what I mean by essentially will be + + + align:start position:0% +and what I mean by essentially will be +pointed out in the learning exercises + + align:start position:0% +pointed out in the learning exercises + + + align:start position:0% +pointed out in the learning exercises +but don't worry about that now the idea + + align:start position:0% +but don't worry about that now the idea + + + align:start position:0% +but don't worry about that now the idea +is simply this Suppose there was some + + align:start position:0% +is simply this Suppose there was some + + + align:start position:0% +is simply this Suppose there was some +way of expressing L of Y Prime and L of + + align:start position:0% +way of expressing L of Y Prime and L of + + + align:start position:0% +way of expressing L of Y Prime and L of +Y double Prime in terms of L of Y I + + align:start position:0% +Y double Prime in terms of L of Y I + + + align:start position:0% +Y double Prime in terms of L of Y I +could then solve the resulting equation + + align:start position:0% +could then solve the resulting equation + + + align:start position:0% +could then solve the resulting equation +for L of Y in terms of s having a table + + align:start position:0% +for L of Y in terms of s having a table + + + align:start position:0% +for L of Y in terms of s having a table +of llast transforms I could then locate + + align:start position:0% +of llast transforms I could then locate + + + align:start position:0% +of llast transforms I could then locate +what that function of s is the llast + + align:start position:0% +what that function of s is the llast + + + align:start position:0% +what that function of s is the llast +transform of and then invert this to + + align:start position:0% +transform of and then invert this to + + + align:start position:0% +transform of and then invert this to +find what my y must have been the + + align:start position:0% +find what my y must have been the + + + align:start position:0% +find what my y must have been the +problem is how do I know that I can + + align:start position:0% +problem is how do I know that I can + + + align:start position:0% +problem is how do I know that I can +express L of Y Prime L of Y Prime L of + + align:start position:0% +express L of Y Prime L of Y Prime L of + + + align:start position:0% +express L of Y Prime L of Y Prime L of +yle prime I'm only going up to the + + align:start position:0% +yle prime I'm only going up to the + + + align:start position:0% +yle prime I'm only going up to the +second derivative in terms of our usual + + align:start position:0% +second derivative in terms of our usual + + + align:start position:0% +second derivative in terms of our usual +Convention of illustrating everything by + + align:start position:0% +Convention of illustrating everything by + + + align:start position:0% +Convention of illustrating everything by +second order equations even though the + + align:start position:0% +second order equations even though the + + + align:start position:0% +second order equations even though the +results hold for higher orders the + + align:start position:0% +results hold for higher orders the + + + align:start position:0% +results hold for higher orders the +question though is how do we know that + + align:start position:0% +question though is how do we know that + + + align:start position:0% +question though is how do we know that +we can express these llast transforms in + + align:start position:0% +we can express these llast transforms in + + + align:start position:0% +we can express these llast transforms in +terms of the llast transform of Y itself + + align:start position:0% +terms of the llast transform of Y itself + + + align:start position:0% +terms of the llast transform of Y itself +and this brings up the second reason why + + align:start position:0% +and this brings up the second reason why + + + align:start position:0% +and this brings up the second reason why +that factor e to the minus St as a + + align:start position:0% +that factor e to the minus St as a + + + align:start position:0% +that factor e to the minus St as a +multiplying factor is so important you + + align:start position:0% +multiplying factor is so important you + + + align:start position:0% +multiplying factor is so important you +see aside from the fact that for most + + align:start position:0% +see aside from the fact that for most + + + align:start position:0% +see aside from the fact that for most +functions that e to the minus St makes + + align:start position:0% +functions that e to the minus St makes + + + align:start position:0% +functions that e to the minus St makes +sure that the resulting integral will + + align:start position:0% +sure that the resulting integral will + + + align:start position:0% +sure that the resulting integral will +converge the other ke property is that + + align:start position:0% +converge the other ke property is that + + + align:start position:0% +converge the other ke property is that +when you integrate or differentiate e to + + align:start position:0% +when you integrate or differentiate e to + + + align:start position:0% +when you integrate or differentiate e to +Theus St because s is a parameter + + align:start position:0% +Theus St because s is a parameter + + + align:start position:0% +Theus St because s is a parameter +meaning it's being treated as a constant + + align:start position:0% +meaning it's being treated as a constant + + + align:start position:0% +meaning it's being treated as a constant +for a given for at a given time what + + align:start position:0% +for a given for at a given time what + + + align:start position:0% +for a given for at a given time what +this thing means is that the integral or + + align:start position:0% +this thing means is that the integral or + + + align:start position:0% +this thing means is that the integral or +the derivative of e to Theus St is + + align:start position:0% +the derivative of e to Theus St is + + + align:start position:0% +the derivative of e to Theus St is +simply a constant times eus St well let + + align:start position:0% +simply a constant times eus St well let + + + align:start position:0% +simply a constant times eus St well let +me show you how this is used let's + + align:start position:0% +me show you how this is used let's + + + align:start position:0% +me show you how this is used let's +suppose for example that I wanted to + + align:start position:0% +suppose for example that I wanted to + + + align:start position:0% +suppose for example that I wanted to +find the laast transform of frime of T + + align:start position:0% +find the laast transform of frime of T + + + align:start position:0% +find the laast transform of frime of T +and I didn't know any tricks and by the + + align:start position:0% +and I didn't know any tricks and by the + + + align:start position:0% +and I didn't know any tricks and by the +way I hope that this is one of The + + align:start position:0% +way I hope that this is one of The + + + align:start position:0% +way I hope that this is one of The +Fringe benefit benefits that this course + + align:start position:0% +Fringe benefit benefits that this course + + + align:start position:0% +Fringe benefit benefits that this course +is teaching you that we do not have to + + align:start position:0% +is teaching you that we do not have to + + + align:start position:0% +is teaching you that we do not have to +be tricky in mathematics all we have to + + align:start position:0% +be tricky in mathematics all we have to + + + align:start position:0% +be tricky in mathematics all we have to +know is the basic definitions and how to + + align:start position:0% +know is the basic definitions and how to + + + align:start position:0% +know is the basic definitions and how to +manipulate them I do admit that it is a + + align:start position:0% +manipulate them I do admit that it is a + + + align:start position:0% +manipulate them I do admit that it is a +stroke of Genius sometimes in inventing + + align:start position:0% +stroke of Genius sometimes in inventing + + + align:start position:0% +stroke of Genius sometimes in inventing +the basic definition that we're going to + + align:start position:0% +the basic definition that we're going to + + + align:start position:0% +the basic definition that we're going to +use for example it's my own belief that + + align:start position:0% +use for example it's my own belief that + + + align:start position:0% +use for example it's my own belief that +it's a lot easier to use the llast + + align:start position:0% +it's a lot easier to use the llast + + + align:start position:0% +it's a lot easier to use the llast +transform than it was to have invented + + align:start position:0% +transform than it was to have invented + + + align:start position:0% +transform than it was to have invented +the concept in the first place but once + + align:start position:0% +the concept in the first place but once + + + align:start position:0% +the concept in the first place but once +I've defined what the llast transform is + + align:start position:0% +I've defined what the llast transform is + + + align:start position:0% +I've defined what the llast transform is +what happens here is very simple namely + + align:start position:0% +what happens here is very simple namely + + + align:start position:0% +what happens here is very simple namely +by definition what is the llast + + align:start position:0% +by definition what is the llast + + + align:start position:0% +by definition what is the llast +transform of frime of T I simply + + align:start position:0% +transform of frime of T I simply + + + align:start position:0% +transform of frime of T I simply +multiply frime of T by E Theus St and + + align:start position:0% +multiply frime of T by E Theus St and + + + align:start position:0% +multiply frime of T by E Theus St and +integrate that from Z to infinity and if + + align:start position:0% +integrate that from Z to infinity and if + + + align:start position:0% +integrate that from Z to infinity and if +that integral converges then the llast + + align:start position:0% +that integral converges then the llast + + + align:start position:0% +that integral converges then the llast +transform exists Let Me Assume for the + + align:start position:0% +transform exists Let Me Assume for the + + + align:start position:0% +transform exists Let Me Assume for the +sake of argument now that the llast + + align:start position:0% +sake of argument now that the llast + + + align:start position:0% +sake of argument now that the llast +transform of f of T exists and by the + + align:start position:0% +transform of f of T exists and by the + + + align:start position:0% +transform of f of T exists and by the +way again remember I'm not really + + align:start position:0% +way again remember I'm not really + + + align:start position:0% +way again remember I'm not really +assuming anything when I'm dealing with + + align:start position:0% +assuming anything when I'm dealing with + + + align:start position:0% +assuming anything when I'm dealing with +linear differential equations with + + align:start position:0% +linear differential equations with + + + align:start position:0% +linear differential equations with +constant coefficients because the + + align:start position:0% +constant coefficients because the + + + align:start position:0% +constant coefficients because the +functions that come up as possible + + align:start position:0% +functions that come up as possible + + + align:start position:0% +functions that come up as possible +solutions there are of exponential order + + align:start position:0% +solutions there are of exponential order + + + align:start position:0% +solutions there are of exponential order +and we have already seen that for + + align:start position:0% +and we have already seen that for + + + align:start position:0% +and we have already seen that for +functions of exponential order the llast + + align:start position:0% +functions of exponential order the llast + + + align:start position:0% +functions of exponential order the llast +transform does indeed exist but at any + + align:start position:0% +transform does indeed exist but at any + + + align:start position:0% +transform does indeed exist but at any +rate the idea is this by definition this + + align:start position:0% +rate the idea is this by definition this + + + align:start position:0% +rate the idea is this by definition this +is the llast transform of frime of T I + + align:start position:0% +is the llast transform of frime of T I + + + align:start position:0% +is the llast transform of frime of T I +would like to be able to integrate this + + align:start position:0% +would like to be able to integrate this + + + align:start position:0% +would like to be able to integrate this +well the idea is that the integral of + + align:start position:0% +well the idea is that the integral of + + + align:start position:0% +well the idea is that the integral of +fime of T is certainly F of T and if I + + align:start position:0% +fime of T is certainly F of T and if I + + + align:start position:0% +fime of T is certainly F of T and if I +up to a constant but that's not + + align:start position:0% +up to a constant but that's not + + + align:start position:0% +up to a constant but that's not +important what I'm thinking of is an + + align:start position:0% +important what I'm thinking of is an + + + align:start position:0% +important what I'm thinking of is an +integrating by Parts notice that if I + + align:start position:0% +integrating by Parts notice that if I + + + align:start position:0% +integrating by Parts notice that if I +let U equal eus St and DV be frime of T + + align:start position:0% +let U equal eus St and DV be frime of T + + + align:start position:0% +let U equal eus St and DV be frime of T +DT then du is minus s e to the minus St + + align:start position:0% +DT then du is minus s e to the minus St + + + align:start position:0% +DT then du is minus s e to the minus St +V would just be F of T remembering the + + align:start position:0% +V would just be F of T remembering the + + + align:start position:0% +V would just be F of T remembering the +recipe for integration by pots remember + + align:start position:0% +recipe for integration by pots remember + + + align:start position:0% +recipe for integration by pots remember +just by way of quick review integral UV + + align:start position:0% +just by way of quick review integral UV + + + align:start position:0% +just by way of quick review integral UV +is equal to UV minus the integral vdu + + align:start position:0% +is equal to UV minus the integral vdu + + + align:start position:0% +is equal to UV minus the integral vdu +what we're saying here is that to + + align:start position:0% +what we're saying here is that to + + + align:start position:0% +what we're saying here is that to +evaluate this integral we simply take + + align:start position:0% +evaluate this integral we simply take + + + align:start position:0% +evaluate this integral we simply take +What U * v e to Us St F of T evaluate + + align:start position:0% +What U * v e to Us St F of T evaluate + + + align:start position:0% +What U * v e to Us St F of T evaluate +that as T goes from 0 to Infinity minus + + align:start position:0% +that as T goes from 0 to Infinity minus + + + align:start position:0% +that as T goes from 0 to Infinity minus +the integral VD du is already negative s + + align:start position:0% +the integral VD du is already negative s + + + align:start position:0% +the integral VD du is already negative s +is a constant so minus integral VD is + + align:start position:0% +is a constant so minus integral VD is + + + align:start position:0% +is a constant so minus integral VD is +just plus s integral 0 to Infinity e to + + align:start position:0% +just plus s integral 0 to Infinity e to + + + align:start position:0% +just plus s integral 0 to Infinity e to +the minus St F of T DT and lo and behold + + align:start position:0% +the minus St F of T DT and lo and behold + + + align:start position:0% +the minus St F of T DT and lo and behold +you see that's that beautiful property + + align:start position:0% +you see that's that beautiful property + + + align:start position:0% +you see that's that beautiful property +of e to the minus + + align:start position:0% +of e to the minus + + + align:start position:0% +of e to the minus +St it's still in here the integral is + + align:start position:0% +St it's still in here the integral is + + + align:start position:0% +St it's still in here the integral is +precisely what we mean by what L of f of + + align:start position:0% +precisely what we mean by what L of f of + + + align:start position:0% +precisely what we mean by what L of f of +T in other words theast transform of f + + align:start position:0% +T in other words theast transform of f + + + align:start position:0% +T in other words theast transform of f +Prime of T is this thing plus stimes the + + align:start position:0% +Prime of T is this thing plus stimes the + + + align:start position:0% +Prime of T is this thing plus stimes the +llast transform of f of T but let me not + + align:start position:0% +llast transform of f of T but let me not + + + align:start position:0% +llast transform of f of T but let me not +be so informal let me not refer to this + + align:start position:0% +be so informal let me not refer to this + + + align:start position:0% +be so informal let me not refer to this +as this thing let's see what this thing + + align:start position:0% +as this thing let's see what this thing + + + align:start position:0% +as this thing let's see what this thing +really is notice that because the llast + + align:start position:0% +really is notice that because the llast + + + align:start position:0% +really is notice that because the llast +transform of f of T is assumed to exist + + align:start position:0% +transform of f of T is assumed to exist + + + align:start position:0% +transform of f of T is assumed to exist +the fact that the integral of this from + + align:start position:0% +the fact that the integral of this from + + + align:start position:0% +the fact that the integral of this from +0 to Infinity is finite means in + + align:start position:0% +0 to Infinity is finite means in + + + align:start position:0% +0 to Infinity is finite means in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +that at Infinity the integr must be zero + + align:start position:0% +that at Infinity the integr must be zero + + + align:start position:0% +that at Infinity the integr must be zero +you see that otherwi how could the area + + align:start position:0% +you see that otherwi how could the area + + + align:start position:0% +you see that otherwi how could the area +under the curve be finite if the curve + + align:start position:0% +under the curve be finite if the curve + + + align:start position:0% +under the curve be finite if the curve +didn't at least ASM totically approach + + align:start position:0% +didn't at least ASM totically approach + + + align:start position:0% +didn't at least ASM totically approach +the T axis so in other words the + + align:start position:0% +the T axis so in other words the + + + align:start position:0% +the T axis so in other words the +assumption that F has a llast transform + + align:start position:0% +assumption that F has a llast transform + + + align:start position:0% +assumption that F has a llast transform +means that the upper limit gives me zero + + align:start position:0% +means that the upper limit gives me zero + + + align:start position:0% +means that the upper limit gives me zero +the lower limit gives me what when I + + align:start position:0% +the lower limit gives me what when I + + + align:start position:0% +the lower limit gives me what when I +plug in t equals z this is e Theus s0 + + align:start position:0% +plug in t equals z this is e Theus s0 + + + align:start position:0% +plug in t equals z this is e Theus s0 +which is one this is f of 0 so the lower + + align:start position:0% +which is one this is f of 0 so the lower + + + align:start position:0% +which is one this is f of 0 so the lower +limit is f of0 and since I'm subtracting + + align:start position:0% +limit is f of0 and since I'm subtracting + + + align:start position:0% +limit is f of0 and since I'm subtracting +the lower limit I have what that the + + align:start position:0% +the lower limit I have what that the + + + align:start position:0% +the lower limit I have what that the +that the thing that I called this thing + + align:start position:0% +that the thing that I called this thing + + + align:start position:0% +that the thing that I called this thing +is more precisely minus F of0 in other + + align:start position:0% +is more precisely minus F of0 in other + + + align:start position:0% +is more precisely minus F of0 in other +words to find the llast transform of + + align:start position:0% +words to find the llast transform of + + + align:start position:0% +words to find the llast transform of +frime of T it's simply minus F of 0 plus + + align:start position:0% +frime of T it's simply minus F of 0 plus + + + align:start position:0% +frime of T it's simply minus F of 0 plus +stimes the llast transform of f of T + + align:start position:0% +stimes the llast transform of f of T + + + align:start position:0% +stimes the llast transform of f of T +well look at if I happen to know what f + + align:start position:0% +well look at if I happen to know what f + + + align:start position:0% +well look at if I happen to know what f +of0 is in other words if I pick a + + align:start position:0% +of0 is in other words if I pick a + + + align:start position:0% +of0 is in other words if I pick a +particular member of the family F of t + + align:start position:0% +particular member of the family F of t + + + align:start position:0% +particular member of the family F of t +uh given the curve yal F of t I + + align:start position:0% +uh given the curve yal F of t I + + + align:start position:0% +uh given the curve yal F of t I +certainly know what f of0 is this says + + align:start position:0% +certainly know what f of0 is this says + + + align:start position:0% +certainly know what f of0 is this says +what the llast transform of frime of T + + align:start position:0% +what the llast transform of frime of T + + + align:start position:0% +what the llast transform of frime of T +is some constant plus s times the llast + + align:start position:0% +is some constant plus s times the llast + + + align:start position:0% +is some constant plus s times the llast +transform of f of T itself in other + + align:start position:0% +transform of f of T itself in other + + + align:start position:0% +transform of f of T itself in other +words somehow or other I have now + + align:start position:0% +words somehow or other I have now + + + align:start position:0% +words somehow or other I have now +managed to express the llast transform + + align:start position:0% +managed to express the llast transform + + + align:start position:0% +managed to express the llast transform +of frime of T in terms of a polinomial + + align:start position:0% +of frime of T in terms of a polinomial + + + align:start position:0% +of frime of T in terms of a polinomial +involving s and the last and the llast + + align:start position:0% +involving s and the last and the llast + + + align:start position:0% +involving s and the last and the llast +transform of f of T Itself by the way + + align:start position:0% +transform of f of T Itself by the way + + + align:start position:0% +transform of f of T Itself by the way +notice that generically here there is + + align:start position:0% +notice that generically here there is + + + align:start position:0% +notice that generically here there is +nothing sacred about F of zero uh or F + + align:start position:0% +nothing sacred about F of zero uh or F + + + align:start position:0% +nothing sacred about F of zero uh or F +think of f as being any function and F + + align:start position:0% +think of f as being any function and F + + + align:start position:0% +think of f as being any function and F +Prime as being its derivative in + + align:start position:0% +Prime as being its derivative in + + + align:start position:0% +Prime as being its derivative in +particular I could allow F Prime to play + + align:start position:0% +particular I could allow F Prime to play + + + align:start position:0% +particular I could allow F Prime to play +the role of f see this says what the + + align:start position:0% +the role of f see this says what the + + + align:start position:0% +the role of f see this says what the +llast transform of the of the derivative + + align:start position:0% +llast transform of the of the derivative + + + align:start position:0% +llast transform of the of the derivative +is minus the function evaluated at zero + + align:start position:0% +is minus the function evaluated at zero + + + align:start position:0% +is minus the function evaluated at zero +plus s times the llast transform of that + + align:start position:0% +plus s times the llast transform of that + + + align:start position:0% +plus s times the llast transform of that +function all right so if I now take my + + align:start position:0% +function all right so if I now take my + + + align:start position:0% +function all right so if I now take my +function to be fpre its derivative is f + + align:start position:0% +function to be fpre its derivative is f + + + align:start position:0% +function to be fpre its derivative is f +Prime the function is itself fpre so all + + align:start position:0% +Prime the function is itself fpre so all + + + align:start position:0% +Prime the function is itself fpre so all +I really do is what go into this recipe + + align:start position:0% +I really do is what go into this recipe + + + align:start position:0% +I really do is what go into this recipe +here every place I see a prime replace + + align:start position:0% +here every place I see a prime replace + + + align:start position:0% +here every place I see a prime replace +it by a double Prime every place I see + + align:start position:0% +it by a double Prime every place I see + + + align:start position:0% +it by a double Prime every place I see +no Prime put a prime in and I have that + + align:start position:0% +no Prime put a prime in and I have that + + + align:start position:0% +no Prime put a prime in and I have that +the llast transform of FP Prime of T is + + align:start position:0% +the llast transform of FP Prime of T is + + + align:start position:0% +the llast transform of FP Prime of T is +minus frime of 0 plus s time the llast + + align:start position:0% +minus frime of 0 plus s time the llast + + + align:start position:0% +minus frime of 0 plus s time the llast +transform of frime of T by the way to + + align:start position:0% +transform of frime of T by the way to + + + align:start position:0% +transform of frime of T by the way to +make sure you see this notice what would + + align:start position:0% +make sure you see this notice what would + + + align:start position:0% +make sure you see this notice what would +the llast transform of fle prime be the + + align:start position:0% +the llast transform of fle prime be the + + + align:start position:0% +the llast transform of fle prime be the +llast transform of fle prime of T would + + align:start position:0% +llast transform of fle prime of T would + + + align:start position:0% +llast transform of fle prime of T would +be minus f Prime of 0 plus s * the lass + + align:start position:0% +be minus f Prime of 0 plus s * the lass + + + align:start position:0% +be minus f Prime of 0 plus s * the lass +transform of f Prime of T so assuming + + align:start position:0% +transform of f Prime of T so assuming + + + align:start position:0% +transform of f Prime of T so assuming +that the that F Prime also has a llast + + align:start position:0% +that the that F Prime also has a llast + + + align:start position:0% +that the that F Prime also has a llast +transform we see what the llast + + align:start position:0% +transform we see what the llast + + + align:start position:0% +transform we see what the llast +transform of FP Prime of T looks like in + + align:start position:0% +transform of FP Prime of T looks like in + + + align:start position:0% +transform of FP Prime of T looks like in +terms of frime of T the llast transform + + align:start position:0% +terms of frime of T the llast transform + + + align:start position:0% +terms of frime of T the llast transform +of frime of T we know what the llast + + align:start position:0% +of frime of T we know what the llast + + + align:start position:0% +of frime of T we know what the llast +transform of frime of T looks like in + + align:start position:0% +transform of frime of T looks like in + + + align:start position:0% +transform of frime of T looks like in +terms of the llast transform of T in + + align:start position:0% +terms of the llast transform of T in + + + align:start position:0% +terms of the llast transform of T in +other words from here I simply replace L + + align:start position:0% +other words from here I simply replace L + + + align:start position:0% +other words from here I simply replace L +of fime of T by its value in this + + align:start position:0% +of fime of T by its value in this + + + align:start position:0% +of fime of T by its value in this +equation and I want up with that the + + align:start position:0% +equation and I want up with that the + + + align:start position:0% +equation and I want up with that the +llast transform of f Prime of T is + + align:start position:0% +llast transform of f Prime of T is + + + align:start position:0% +llast transform of f Prime of T is +nothing more than minus frime of 0 - s * + + align:start position:0% +nothing more than minus frime of 0 - s * + + + align:start position:0% +nothing more than minus frime of 0 - s * +F of 0 plus S2 L of f of T and now you + + align:start position:0% +F of 0 plus S2 L of f of T and now you + + + align:start position:0% +F of 0 plus S2 L of f of T and now you +see I've solved the problem that I was + + align:start position:0% +see I've solved the problem that I was + + + align:start position:0% +see I've solved the problem that I was +discussing over here namely once I know + + align:start position:0% +discussing over here namely once I know + + + align:start position:0% +discussing over here namely once I know +what y of zero is I'm using by the way + + align:start position:0% +what y of zero is I'm using by the way + + + align:start position:0% +what y of zero is I'm using by the way +don't confuse the F here with the F here + + align:start position:0% +don't confuse the F here with the F here + + + align:start position:0% +don't confuse the F here with the F here +that's an unfortunate Choice which I've + + align:start position:0% +that's an unfortunate Choice which I've + + + align:start position:0% +that's an unfortunate Choice which I've +just notice the F that I'm referring to + + align:start position:0% +just notice the F that I'm referring to + + + align:start position:0% +just notice the F that I'm referring to +here names the function whose llas + + align:start position:0% +here names the function whose llas + + + align:start position:0% +here names the function whose llas +transform I'm trying to find notice that + + align:start position:0% +transform I'm trying to find notice that + + + align:start position:0% +transform I'm trying to find notice that +the fime and FP Prime are served by y + + align:start position:0% +the fime and FP Prime are served by y + + + align:start position:0% +the fime and FP Prime are served by y +Prime and Y Prime here what we're saying + + align:start position:0% +Prime and Y Prime here what we're saying + + + align:start position:0% +Prime and Y Prime here what we're saying +in terms of this notation is that I can + + align:start position:0% +in terms of this notation is that I can + + + align:start position:0% +in terms of this notation is that I can +express L of YP Prime and L of Y Prime + + align:start position:0% +express L of YP Prime and L of Y Prime + + + align:start position:0% +express L of YP Prime and L of Y Prime +in terms of the llast transform of L of + + align:start position:0% +in terms of the llast transform of L of + + + align:start position:0% +in terms of the llast transform of L of +Y plus powers of s provided I know only + + align:start position:0% +Y plus powers of s provided I know only + + + align:start position:0% +Y plus powers of s provided I know only +what Y of0 is and what y Prime of0 is + + align:start position:0% +what Y of0 is and what y Prime of0 is + + + align:start position:0% +what Y of0 is and what y Prime of0 is +and by the way again notice that in a + + align:start position:0% +and by the way again notice that in a + + + align:start position:0% +and by the way again notice that in a +physical problem it is very natural to + + align:start position:0% +physical problem it is very natural to + + + align:start position:0% +physical problem it is very natural to +look at Y and Y Prime when T equals z + + align:start position:0% +look at Y and Y Prime when T equals z + + + align:start position:0% +look at Y and Y Prime when T equals z +because in many instances T equals 0 + + align:start position:0% +because in many instances T equals 0 + + + align:start position:0% +because in many instances T equals 0 +represents the time at which we've + + align:start position:0% +represents the time at which we've + + + align:start position:0% +represents the time at which we've +started the measurement at our + + align:start position:0% +started the measurement at our + + + align:start position:0% +started the measurement at our +experiment and this becomes a very + + align:start position:0% +experiment and this becomes a very + + + align:start position:0% +experiment and this becomes a very +natural interpretation for what you mean + + align:start position:0% +natural interpretation for what you mean + + + align:start position:0% +natural interpretation for what you mean +by the initial conditions namely what's + + align:start position:0% +by the initial conditions namely what's + + + align:start position:0% +by the initial conditions namely what's +going on when T equals z any rate we are + + align:start position:0% +going on when T equals z any rate we are + + + align:start position:0% +going on when T equals z any rate we are +now in a position to apply our results + + align:start position:0% +now in a position to apply our results + + + align:start position:0% +now in a position to apply our results +to an actual linear differential + + align:start position:0% +to an actual linear differential + + + align:start position:0% +to an actual linear differential +equation with constant coefficients + + align:start position:0% +equation with constant coefficients + + + align:start position:0% +equation with constant coefficients +given initial conditions as to what's + + align:start position:0% +given initial conditions as to what's + + + align:start position:0% +given initial conditions as to what's +happening at zero in terms of the Y + + align:start position:0% +happening at zero in terms of the Y + + + align:start position:0% +happening at zero in terms of the Y +coordinate and the Y Prime coordinate + + align:start position:0% +coordinate and the Y Prime coordinate + + + align:start position:0% +coordinate and the Y Prime coordinate +Etc in other words as an application to + + align:start position:0% +Etc in other words as an application to + + + align:start position:0% +Etc in other words as an application to +linear differential equations with + + align:start position:0% +linear differential equations with + + + align:start position:0% +linear differential equations with +constant coefficients suppose we want to + + align:start position:0% +constant coefficients suppose we want to + + + align:start position:0% +constant coefficients suppose we want to +solve meaning what find what function y + + align:start position:0% +solve meaning what find what function y + + + align:start position:0% +solve meaning what find what function y +is of T if y Prime - 4 y Prime + 3 yal e + + align:start position:0% +is of T if y Prime - 4 y Prime + 3 yal e + + + align:start position:0% +is of T if y Prime - 4 y Prime + 3 yal e +2 T given that my initial conditions + + align:start position:0% +2 T given that my initial conditions + + + align:start position:0% +2 T given that my initial conditions +namely when T is zero Y is going to be + + align:start position:0% +namely when T is zero Y is going to be + + + align:start position:0% +namely when T is zero Y is going to be +zero and Y Prime is going to be one I + + align:start position:0% +zero and Y Prime is going to be one I + + + align:start position:0% +zero and Y Prime is going to be one I +these could be any conditions I want + + align:start position:0% +these could be any conditions I want + + + align:start position:0% +these could be any conditions I want +over here I just chose these to give me + + align:start position:0% +over here I just chose these to give me + + + align:start position:0% +over here I just chose these to give me +a a simple algebraic uh example and I'll + + align:start position:0% +a a simple algebraic uh example and I'll + + + align:start position:0% +a a simple algebraic uh example and I'll +pick more complicated things in the + + align:start position:0% +pick more complicated things in the + + + align:start position:0% +pick more complicated things in the +exercises but the idea is this we have + + align:start position:0% +exercises but the idea is this we have + + + align:start position:0% +exercises but the idea is this we have +already seen by linearity that if I take + + align:start position:0% +already seen by linearity that if I take + + + align:start position:0% +already seen by linearity that if I take +theast transform of both sides here I + + align:start position:0% +theast transform of both sides here I + + + align:start position:0% +theast transform of both sides here I +have that L of Y Prime minus 4 L of Y + + align:start position:0% +have that L of Y Prime minus 4 L of Y + + + align:start position:0% +have that L of Y Prime minus 4 L of Y +prime plus 3 l of Y is the llast + + align:start position:0% +prime plus 3 l of Y is the llast + + + align:start position:0% +prime plus 3 l of Y is the llast +transform of e to 2T now we just saw on + + align:start position:0% +transform of e to 2T now we just saw on + + + align:start position:0% +transform of e to 2T now we just saw on +right over here that the llast transform + + align:start position:0% +right over here that the llast transform + + + align:start position:0% +right over here that the llast transform +of Y Prime is minus y Prime evaluated 0 + + align:start position:0% +of Y Prime is minus y Prime evaluated 0 + + + align:start position:0% +of Y Prime is minus y Prime evaluated 0 +- s y of 0 + s^2 L of Y the llast + + align:start position:0% +- s y of 0 + s^2 L of Y the llast + + + align:start position:0% +- s y of 0 + s^2 L of Y the llast +transform of Y Prime was minus you see y + + align:start position:0% +transform of Y Prime was minus you see y + + + align:start position:0% +transform of Y Prime was minus you see y +of0 plus s l y you see so minus 4 * that + + align:start position:0% +of0 plus s l y you see so minus 4 * that + + + align:start position:0% +of0 plus s l y you see so minus 4 * that +is just 4 * y of 0 - 4 S L of y + 3 l of + + align:start position:0% +is just 4 * y of 0 - 4 S L of y + 3 l of + + + align:start position:0% +is just 4 * y of 0 - 4 S L of y + 3 l of +Y and we saw earlier that the llast + + align:start position:0% +Y and we saw earlier that the llast + + + align:start position:0% +Y and we saw earlier that the llast +transform of e to the a t is 1 / s- a + + align:start position:0% +transform of e to the a t is 1 / s- a + + + align:start position:0% +transform of e to the a t is 1 / s- a +where s is is any number greater than + + align:start position:0% +where s is is any number greater than + + + align:start position:0% +where s is is any number greater than +two in particular this is that formula + + align:start position:0% +two in particular this is that formula + + + align:start position:0% +two in particular this is that formula +with a equal s is any number greater + + align:start position:0% +with a equal s is any number greater + + + align:start position:0% +with a equal s is any number greater +than a in particular this is that + + align:start position:0% +than a in particular this is that + + + align:start position:0% +than a in particular this is that +formula with a equal to 2 so the + + align:start position:0% +formula with a equal to 2 so the + + + align:start position:0% +formula with a equal to 2 so the +transform of e 2 T is 1 / s- 2 provided + + align:start position:0% +transform of e 2 T is 1 / s- 2 provided + + + align:start position:0% +transform of e 2 T is 1 / s- 2 provided +s is greater than two by the way notice + + align:start position:0% +s is greater than two by the way notice + + + align:start position:0% +s is greater than two by the way notice +up to this point I have not used the + + align:start position:0% +up to this point I have not used the + + + align:start position:0% +up to this point I have not used the +initial conditions I have not used the + + align:start position:0% +initial conditions I have not used the + + + align:start position:0% +initial conditions I have not used the +fact that y of 0 is 0 and that y Prime + + align:start position:0% +fact that y of 0 is 0 and that y Prime + + + align:start position:0% +fact that y of 0 is 0 and that y Prime +of 0 is 1 notice that even without this + + align:start position:0% +of 0 is 1 notice that even without this + + + align:start position:0% +of 0 is 1 notice that even without this +the L of Y is here by itself it's going + + align:start position:0% +the L of Y is here by itself it's going + + + align:start position:0% +the L of Y is here by itself it's going +to be multiplied by s^2 - 4 S + 3 these + + align:start position:0% +to be multiplied by s^2 - 4 S + 3 these + + + align:start position:0% +to be multiplied by s^2 - 4 S + 3 these +terms can go over onto the other side of + + align:start position:0% +terms can go over onto the other side of + + + align:start position:0% +terms can go over onto the other side of +the equation I will get a function of s + + align:start position:0% +the equation I will get a function of s + + + align:start position:0% +the equation I will get a function of s +alone I then divide through by s^2 - 4 S + + align:start position:0% +alone I then divide through by s^2 - 4 S + + + align:start position:0% +alone I then divide through by s^2 - 4 S ++ 3 that will give me L of Y as a + + align:start position:0% ++ 3 that will give me L of Y as a + + + align:start position:0% ++ 3 that will give me L of Y as a +function of s and if I can then find one + + align:start position:0% +function of s and if I can then find one + + + align:start position:0% +function of s and if I can then find one +function which has that function of s as + + align:start position:0% +function which has that function of s as + + + align:start position:0% +function which has that function of s as +its theast transform I can conclude that + + align:start position:0% +its theast transform I can conclude that + + + align:start position:0% +its theast transform I can conclude that +that function is the one I'm looking for + + align:start position:0% +that function is the one I'm looking for + + + align:start position:0% +that function is the one I'm looking for +provided only that L is a one:1 operator + + align:start position:0% +provided only that L is a one:1 operator + + + align:start position:0% +provided only that L is a one:1 operator +that the llas transform is a one to one + + align:start position:0% +that the llas transform is a one to one + + + align:start position:0% +that the llas transform is a one to one +function at any rate all I did in our + + align:start position:0% +function at any rate all I did in our + + + align:start position:0% +function at any rate all I did in our +problem was to simplify this by + + align:start position:0% +problem was to simplify this by + + + align:start position:0% +problem was to simplify this by +specifying that y of 0 was 0 and that y + + align:start position:0% +specifying that y of 0 was 0 and that y + + + align:start position:0% +specifying that y of 0 was 0 and that y +Prime of 0 was one these two terms drop + + align:start position:0% +Prime of 0 was one these two terms drop + + + align:start position:0% +Prime of 0 was one these two terms drop +out this is minus one it comes over onto + + align:start position:0% +out this is minus one it comes over onto + + + align:start position:0% +out this is minus one it comes over onto +the other side as + one and so I wind up + + align:start position:0% +the other side as + one and so I wind up + + + align:start position:0% +the other side as + one and so I wind up +with this particular equation okay and + + align:start position:0% +with this particular equation okay and + + + align:start position:0% +with this particular equation okay and +by the way notice that this simply says + + align:start position:0% +by the way notice that this simply says + + + align:start position:0% +by the way notice that this simply says +what s - 2 + 1/ S - 2 in other words + + align:start position:0% +what s - 2 + 1/ S - 2 in other words + + + align:start position:0% +what s - 2 + 1/ S - 2 in other words +this is s -1 / s - 2 this factors into s + + align:start position:0% +this is s -1 / s - 2 this factors into s + + + align:start position:0% +this is s -1 / s - 2 this factors into s +-1 * s - 3 so in other words what I'm + + align:start position:0% +-1 * s - 3 so in other words what I'm + + + align:start position:0% +-1 * s - 3 so in other words what I'm +now faced with is that s -1 * s - 3 * L + + align:start position:0% +now faced with is that s -1 * s - 3 * L + + + align:start position:0% +now faced with is that s -1 * s - 3 * L +of Y is equal to S -1 / s - 2 I have to + + align:start position:0% +of Y is equal to S -1 / s - 2 I have to + + + align:start position:0% +of Y is equal to S -1 / s - 2 I have to +be + + align:start position:0% +be + + + align:start position:0% +be +careful you see I want to divide see I + + align:start position:0% +careful you see I want to divide see I + + + align:start position:0% +careful you see I want to divide see I +want to be able to cancel out the S + + align:start position:0% +want to be able to cancel out the S + + + align:start position:0% +want to be able to cancel out the S +minus 1's here I want to be able to + + align:start position:0% +minus 1's here I want to be able to + + + align:start position:0% +minus 1's here I want to be able to +divide through by s - 3 I have to be + + align:start position:0% +divide through by s - 3 I have to be + + + align:start position:0% +divide through by s - 3 I have to be +careful of zero denominators and the + + align:start position:0% +careful of zero denominators and the + + + align:start position:0% +careful of zero denominators and the +safest way to take care of everything is + + align:start position:0% +safest way to take care of everything is + + + align:start position:0% +safest way to take care of everything is +that all I really care about is whether + + align:start position:0% +that all I really care about is whether + + + align:start position:0% +that all I really care about is whether +the llast transform exists for + + align:start position:0% +the llast transform exists for + + + align:start position:0% +the llast transform exists for +sufficiently large values of s to get + + align:start position:0% +sufficiently large values of s to get + + + align:start position:0% +sufficiently large values of s to get +rid of my headache I'll simply assume + + align:start position:0% +rid of my headache I'll simply assume + + + align:start position:0% +rid of my headache I'll simply assume +that I'm not even looking at the laas + + align:start position:0% +that I'm not even looking at the laas + + + align:start position:0% +that I'm not even looking at the laas +transform until shall we say f s is + + align:start position:0% +transform until shall we say f s is + + + align:start position:0% +transform until shall we say f s is +greater than three you see once s is + + align:start position:0% +greater than three you see once s is + + + align:start position:0% +greater than three you see once s is +greater than three this Factor can't be + + align:start position:0% +greater than three this Factor can't be + + + align:start position:0% +greater than three this Factor can't be +zero this Factor can't be zero + + align:start position:0% +zero this Factor can't be zero + + + align:start position:0% +zero this Factor can't be zero +consequently I can solve for L of Y and + + align:start position:0% +consequently I can solve for L of Y and + + + align:start position:0% +consequently I can solve for L of Y and +conclude that L of Y is 1 / s - 3 * s - + + align:start position:0% +conclude that L of Y is 1 / s - 3 * s - + + + align:start position:0% +conclude that L of Y is 1 / s - 3 * s - +2 provided that s is greater than 3 now + + align:start position:0% +2 provided that s is greater than 3 now + + + align:start position:0% +2 provided that s is greater than 3 now +I resort to that same method + + align:start position:0% +I resort to that same method + + + align:start position:0% +I resort to that same method +of partial fractions that we used when + + align:start position:0% +of partial fractions that we used when + + + align:start position:0% +of partial fractions that we used when +we integrated back in part one using + + align:start position:0% +we integrated back in part one using + + + align:start position:0% +we integrated back in part one using +partial fractions I simply try to find + + align:start position:0% +partial fractions I simply try to find + + + align:start position:0% +partial fractions I simply try to find +constants A and B such that I can write + + align:start position:0% +constants A and B such that I can write + + + align:start position:0% +constants A and B such that I can write +this as a/ s- 3 + b/ s-2 in other words + + align:start position:0% +this as a/ s- 3 + b/ s-2 in other words + + + align:start position:0% +this as a/ s- 3 + b/ s-2 in other words +break this down into simpler Parts + + align:start position:0% +break this down into simpler Parts + + + align:start position:0% +break this down into simpler Parts +sparing you the details it follows very + + align:start position:0% +sparing you the details it follows very + + + align:start position:0% +sparing you the details it follows very +simply in this case that this expression + + align:start position:0% +simply in this case that this expression + + + align:start position:0% +simply in this case that this expression +is simply 1 / s - 3 - 1 / s -2 in other + + align:start position:0% +is simply 1 / s - 3 - 1 / s -2 in other + + + align:start position:0% +is simply 1 / s - 3 - 1 / s -2 in other +words that if I put this over common + + align:start position:0% +words that if I put this over common + + + align:start position:0% +words that if I put this over common +denominator I get 1 / s - 3 * s - 2 now + + align:start position:0% +denominator I get 1 / s - 3 * s - 2 now + + + align:start position:0% +denominator I get 1 / s - 3 * s - 2 now +here's where the kicker comes in + + align:start position:0% +here's where the kicker comes in + + + align:start position:0% +here's where the kicker comes in +remember we have already seen that 1 / s + + align:start position:0% +remember we have already seen that 1 / s + + + align:start position:0% +remember we have already seen that 1 / s +minus a is the laast transform of e to + + align:start position:0% +minus a is the laast transform of e to + + + align:start position:0% +minus a is the laast transform of e to +the a t provided s is greater than a in + + align:start position:0% +the a t provided s is greater than a in + + + align:start position:0% +the a t provided s is greater than a in +particular the llast transform of e to + + align:start position:0% +particular the llast transform of e to + + + align:start position:0% +particular the llast transform of e to +3T would 1 / s- 3 provided s was greater + + align:start position:0% +3T would 1 / s- 3 provided s was greater + + + align:start position:0% +3T would 1 / s- 3 provided s was greater +than 3 similarly the llast transform of + + align:start position:0% +than 3 similarly the llast transform of + + + align:start position:0% +than 3 similarly the llast transform of +e 2T would be 1 / s- 2 provided s was + + align:start position:0% +e 2T would be 1 / s- 2 provided s was + + + align:start position:0% +e 2T would be 1 / s- 2 provided s was +greater than two by the way notice that + + align:start position:0% +greater than two by the way notice that + + + align:start position:0% +greater than two by the way notice that +both of these conditions are obeyed as + + align:start position:0% +both of these conditions are obeyed as + + + align:start position:0% +both of these conditions are obeyed as +soon as s is greater than three + + align:start position:0% +soon as s is greater than three + + + align:start position:0% +soon as s is greater than three +obviously if s is greater than three it + + align:start position:0% +obviously if s is greater than three it + + + align:start position:0% +obviously if s is greater than three it +must be greater than two so I'm sure + + align:start position:0% +must be greater than two so I'm sure + + + align:start position:0% +must be greater than two so I'm sure +that both of these results are true once + + align:start position:0% +that both of these results are true once + + + align:start position:0% +that both of these results are true once +s is greater than three you see the same + + align:start position:0% +s is greater than three you see the same + + + align:start position:0% +s is greater than three you see the same +three I have up here now by arity I know + + align:start position:0% +three I have up here now by arity I know + + + align:start position:0% +three I have up here now by arity I know +that the llast transform of a difference + + align:start position:0% +that the llast transform of a difference + + + align:start position:0% +that the llast transform of a difference +is the difference of the llast + + align:start position:0% +is the difference of the llast + + + align:start position:0% +is the difference of the llast +transforms you see by equals added to + + align:start position:0% +transforms you see by equals added to + + + align:start position:0% +transforms you see by equals added to +equals this tells me that L of e 3T + + align:start position:0% +equals this tells me that L of e 3T + + + align:start position:0% +equals this tells me that L of e 3T +minus L of e 2T is 1 / s - 3 - 1 / s- 2 + + align:start position:0% +minus L of e 2T is 1 / s - 3 - 1 / s- 2 + + + align:start position:0% +minus L of e 2T is 1 / s - 3 - 1 / s- 2 +but by linearity e l of e to 3T minus L + + align:start position:0% +but by linearity e l of e to 3T minus L + + + align:start position:0% +but by linearity e l of e to 3T minus L +of e to 2T is L of the quantity e to 3T + + align:start position:0% +of e to 2T is L of the quantity e to 3T + + + align:start position:0% +of e to 2T is L of the quantity e to 3T +minus E 2T in particular then do I know + + align:start position:0% +minus E 2T in particular then do I know + + + align:start position:0% +minus E 2T in particular then do I know +one function whose llast transform is 1 + + align:start position:0% +one function whose llast transform is 1 + + + align:start position:0% +one function whose llast transform is 1 +/ s - 3 - 1 / s -2 and the answer is yes + + align:start position:0% +/ s - 3 - 1 / s -2 and the answer is yes + + + align:start position:0% +/ s - 3 - 1 / s -2 and the answer is yes +we've just constructed it namely the + + align:start position:0% +we've just constructed it namely the + + + align:start position:0% +we've just constructed it namely the +function y = e 3 T minus E 2 T in other + + align:start position:0% +function y = e 3 T minus E 2 T in other + + + align:start position:0% +function y = e 3 T minus E 2 T in other +words what we do know is that in any + + align:start position:0% +words what we do know is that in any + + + align:start position:0% +words what we do know is that in any +event whether Y is the given function or + + align:start position:0% +event whether Y is the given function or + + + align:start position:0% +event whether Y is the given function or +not whatever L of Y is it's l of e 3 T + + align:start position:0% +not whatever L of Y is it's l of e 3 T + + + align:start position:0% +not whatever L of Y is it's l of e 3 T +minus E 2T and therefore we could + + align:start position:0% +minus E 2T and therefore we could + + + align:start position:0% +minus E 2T and therefore we could +conclude that Y Must equal e 3 T minus E + + align:start position:0% +conclude that Y Must equal e 3 T minus E + + + align:start position:0% +conclude that Y Must equal e 3 T minus E +2 T provided that L is 1 to one provided + + align:start position:0% +2 T provided that L is 1 to one provided + + + align:start position:0% +2 T provided that L is 1 to one provided +that there is only one function that can + + align:start position:0% +that there is only one function that can + + + align:start position:0% +that there is only one function that can +have a given Li transform you see you + + align:start position:0% +have a given Li transform you see you + + + align:start position:0% +have a given Li transform you see you +cannot automatically conclude that + + align:start position:0% +cannot automatically conclude that + + + align:start position:0% +cannot automatically conclude that +because these two things are equal the + + align:start position:0% +because these two things are equal the + + + align:start position:0% +because these two things are equal the +that L of with the whole expression is + + align:start position:0% +that L of with the whole expression is + + + align:start position:0% +that L of with the whole expression is +equal that the inputs must be equal for + + align:start position:0% +equal that the inputs must be equal for + + + align:start position:0% +equal that the inputs must be equal for +example you cannot conclude that xal < / + + align:start position:0% +example you cannot conclude that xal < / + + + align:start position:0% +example you cannot conclude that xal < / +6 simply because you know that Sin xal + + align:start position:0% +6 simply because you know that Sin xal + + + align:start position:0% +6 simply because you know that Sin xal +Sin pi/ 6 you see the sign function is + + align:start position:0% +Sin pi/ 6 you see the sign function is + + + align:start position:0% +Sin pi/ 6 you see the sign function is +not 1: one well at any rate I think you + + align:start position:0% +not 1: one well at any rate I think you + + + align:start position:0% +not 1: one well at any rate I think you +can sense intuitively + + align:start position:0% +can sense intuitively + + + align:start position:0% +can sense intuitively +that because we already know that for + + align:start position:0% +that because we already know that for + + + align:start position:0% +that because we already know that for +linear differential equations with + + align:start position:0% +linear differential equations with + + + align:start position:0% +linear differential equations with +constant coefficients there are no + + align:start position:0% +constant coefficients there are no + + + align:start position:0% +constant coefficients there are no +singular Solutions and once you found + + align:start position:0% +singular Solutions and once you found + + + align:start position:0% +singular Solutions and once you found +one solution subject to given initial + + align:start position:0% +one solution subject to given initial + + + align:start position:0% +one solution subject to given initial +conditions you found them all I think + + align:start position:0% +conditions you found them all I think + + + align:start position:0% +conditions you found them all I think +you can guess that at least for + + align:start position:0% +you can guess that at least for + + + align:start position:0% +you can guess that at least for +functions of exponential order this + + align:start position:0% +functions of exponential order this + + + align:start position:0% +functions of exponential order this +should be a True Result and the fact + + align:start position:0% +should be a True Result and the fact + + + align:start position:0% +should be a True Result and the fact +that it is true is known in the + + align:start position:0% +that it is true is known in the + + + align:start position:0% +that it is true is known in the +literature under the name of lures + + align:start position:0% +literature under the name of lures + + + align:start position:0% +literature under the name of lures +theorem luch not lur CH but ler CH it's + + align:start position:0% +theorem luch not lur CH but ler CH it's + + + align:start position:0% +theorem luch not lur CH but ler CH it's +known under the name of luches theorem + + align:start position:0% +known under the name of luches theorem + + + align:start position:0% +known under the name of luches theorem +and by but and I have taken the liberty + + align:start position:0% +and by but and I have taken the liberty + + + align:start position:0% +and by but and I have taken the liberty +of stating it in a less controversial + + align:start position:0% +of stating it in a less controversial + + + align:start position:0% +of stating it in a less controversial +form saving the generalization for the + + align:start position:0% +form saving the generalization for the + + + align:start position:0% +form saving the generalization for the +learning exercises but essentially all + + align:start position:0% +learning exercises but essentially all + + + align:start position:0% +learning exercises but essentially all +luches theorem says is this if f and g + + align:start position:0% +luches theorem says is this if f and g + + + align:start position:0% +luches theorem says is this if f and g +are continuous and of exponential order + + align:start position:0% +are continuous and of exponential order + + + align:start position:0% +are continuous and of exponential order +Okay then if the llast transform of f + + align:start position:0% +Okay then if the llast transform of f + + + align:start position:0% +Okay then if the llast transform of f +equals the llast transform of G for all + + align:start position:0% +equals the llast transform of G for all + + + align:start position:0% +equals the llast transform of G for all +sufficiently large values of s in other + + align:start position:0% +sufficiently large values of s in other + + + align:start position:0% +sufficiently large values of s in other +words if Beyond a certain S F Bar of s + + align:start position:0% +words if Beyond a certain S F Bar of s + + + align:start position:0% +words if Beyond a certain S F Bar of s +equals g bar of s in other words f and g + + align:start position:0% +equals g bar of s in other words f and g + + + align:start position:0% +equals g bar of s in other words f and g +have the same llas transform then f and + + align:start position:0% +have the same llas transform then f and + + + align:start position:0% +have the same llas transform then f and +g must be identical and there is a + + align:start position:0% +g must be identical and there is a + + + align:start position:0% +g must be identical and there is a +slight modification of this that comes + + align:start position:0% +slight modification of this that comes + + + align:start position:0% +slight modification of this that comes +up if you leave out the word continuous + + align:start position:0% +up if you leave out the word continuous + + + align:start position:0% +up if you leave out the word continuous +here L's theorem is stated only in terms + + align:start position:0% +here L's theorem is stated only in terms + + + align:start position:0% +here L's theorem is stated only in terms +of f and g being peace wise continuous + + align:start position:0% +of f and g being peace wise continuous + + + align:start position:0% +of f and g being peace wise continuous +in other words there could be jump + + align:start position:0% +in other words there could be jump + + + align:start position:0% +in other words there could be jump +discontinuities in the curves and things + + align:start position:0% +discontinuities in the curves and things + + + align:start position:0% +discontinuities in the curves and things +like this at which case this would hold + + align:start position:0% +like this at which case this would hold + + + align:start position:0% +like this at which case this would hold +except possibly at the points at which + + align:start position:0% +except possibly at the points at which + + + align:start position:0% +except possibly at the points at which +you had jump uh discontinuities I prefer + + align:start position:0% +you had jump uh discontinuities I prefer + + + align:start position:0% +you had jump uh discontinuities I prefer +not to get into this at this particular + + align:start position:0% +not to get into this at this particular + + + align:start position:0% +not to get into this at this particular +time but rather to wrap up our lecture + + align:start position:0% +time but rather to wrap up our lecture + + + align:start position:0% +time but rather to wrap up our lecture +at this particular point and to Simply + + align:start position:0% +at this particular point and to Simply + + + align:start position:0% +at this particular point and to Simply +say that we have done what now we have + + align:start position:0% +say that we have done what now we have + + + align:start position:0% +say that we have done what now we have +studied linear differential equations we + + align:start position:0% +studied linear differential equations we + + + align:start position:0% +studied linear differential equations we +have used this last lecture to introduce + + align:start position:0% +have used this last lecture to introduce + + + align:start position:0% +have used this last lecture to introduce +the concept of the lass + + align:start position:0% +the concept of the lass + + + align:start position:0% +the concept of the lass +transform which has secondary value in + + align:start position:0% +transform which has secondary value in + + + align:start position:0% +transform which has secondary value in +terms of solving differential equations + + align:start position:0% +terms of solving differential equations + + + align:start position:0% +terms of solving differential equations +but which has other applications that go + + align:start position:0% +but which has other applications that go + + + align:start position:0% +but which has other applications that go +far beyond the scope of this particular + + align:start position:0% +far beyond the scope of this particular + + + align:start position:0% +far beyond the scope of this particular +course and what I'm hoping is that this + + align:start position:0% +course and what I'm hoping is that this + + + align:start position:0% +course and what I'm hoping is that this +rather introductory lecture coupled with + + align:start position:0% +rather introductory lecture coupled with + + + align:start position:0% +rather introductory lecture coupled with +well-chosen + + align:start position:0% +well-chosen + + + align:start position:0% +well-chosen +exercises will give you enough insight + + align:start position:0% +exercises will give you enough insight + + + align:start position:0% +exercises will give you enough insight +to theast transform so that you will be + + align:start position:0% +to theast transform so that you will be + + + align:start position:0% +to theast transform so that you will be +able to handle it not only in terms of + + align:start position:0% +able to handle it not only in terms of + + + align:start position:0% +able to handle it not only in terms of +solving linear differential equations + + align:start position:0% +solving linear differential equations + + + align:start position:0% +solving linear differential equations +with constant coefficients but in other + + align:start position:0% +with constant coefficients but in other + + + align:start position:0% +with constant coefficients but in other +contexts where they might occur in the + + align:start position:0% +contexts where they might occur in the + + + align:start position:0% +contexts where they might occur in the +particular line of work and research + + align:start position:0% +particular line of work and research + + + align:start position:0% +particular line of work and research +that you're doing at any rate this + + align:start position:0% +that you're doing at any rate this + + + align:start position:0% +that you're doing at any rate this +completes our work on block seven and in + + align:start position:0% +completes our work on block seven and in + + + align:start position:0% +completes our work on block seven and in +our next lecture what we shall do is + + align:start position:0% +our next lecture what we shall do is + + + align:start position:0% +our next lecture what we shall do is +start the final block of our course and + + align:start position:0% +start the final block of our course and + + + align:start position:0% +start the final block of our course and +revisit the concept of vector spaces + + align:start position:0% +revisit the concept of vector spaces + + + align:start position:0% +revisit the concept of vector spaces +from hopefully a more productive point + + align:start position:0% +from hopefully a more productive point + + + align:start position:0% +from hopefully a more productive point +of view than what we've had before but + + align:start position:0% +of view than what we've had before but + + + align:start position:0% +of view than what we've had before but +more about that next time until next + + align:start position:0% +more about that next time until next + + + align:start position:0% +more about that next time until next +time + + align:start position:0% +time + + + align:start position:0% +time +goodbye funding for the publication of + + align:start position:0% +goodbye funding for the publication of + + + align:start position:0% +goodbye funding for the publication of +this video was provided by the Gabriella + + align:start position:0% +this video was provided by the Gabriella + + + align:start position:0% +this video was provided by the Gabriella +and Paul rosenbom + + align:start position:0% +and Paul rosenbom + + + align:start position:0% +and Paul rosenbom +foundation help ocw continue to provide + + align:start position:0% +foundation help ocw continue to provide + + + align:start position:0% +foundation help ocw continue to provide +free and open access to MIT courses by + + align:start position:0% +free and open access to MIT courses by + + + align:start position:0% +free and open access to MIT courses by +making a donation at ocw.mit.edu/donate \ No newline at end of file diff --git a/b1eKhyC9TTo.txt b/b1eKhyC9TTo.txt new file mode 100644 index 0000000000000000000000000000000000000000..8708d90379d35da86cfaff4cb4fdd7f65bd9c20a --- /dev/null +++ b/b1eKhyC9TTo.txt @@ -0,0 +1,9736 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so I'm back + + align:start position:0% +so I'm back + + + align:start position:0% +so I'm back +welcome back also to al-suri so today + + align:start position:0% +welcome back also to al-suri so today + + + align:start position:0% +welcome back also to al-suri so today +what we are going to do is to is + + align:start position:0% +what we are going to do is to is + + + align:start position:0% +what we are going to do is to is +something really interesting so it's to + + align:start position:0% +something really interesting so it's to + + + align:start position:0% +something really interesting so it's to +understand how we use symmetry to help + + align:start position:0% +understand how we use symmetry to help + + + align:start position:0% +understand how we use symmetry to help +us with prediction of physical + + align:start position:0% +us with prediction of physical + + + align:start position:0% +us with prediction of physical +situations so so first I will go through + + align:start position:0% +situations so so first I will go through + + + align:start position:0% +situations so so first I will go through +two concrete examples of symmetry and + + align:start position:0% +two concrete examples of symmetry and + + + align:start position:0% +two concrete examples of symmetry and +see what we can learn from there and + + align:start position:0% +see what we can learn from there and + + + align:start position:0% +see what we can learn from there and +also today we are going to go to + + align:start position:0% +also today we are going to go to + + + align:start position:0% +also today we are going to go to +infinite number of coupled oscillators + + align:start position:0% +infinite number of coupled oscillators + + + align:start position:0% +infinite number of coupled oscillators +okay okay I think we are done with + + align:start position:0% +okay okay I think we are done with + + + align:start position:0% +okay okay I think we are done with +finite numbers okay all right so what we + + align:start position:0% +finite numbers okay all right so what we + + + align:start position:0% +finite numbers okay all right so what we +have learned last time when Pollock was + + align:start position:0% +have learned last time when Pollock was + + + align:start position:0% +have learned last time when Pollock was +giving the lecture I hope we have + + align:start position:0% +giving the lecture I hope we have + + + align:start position:0% +giving the lecture I hope we have +learned a driving force can excite a + + align:start position:0% +learned a driving force can excite a + + + align:start position:0% +learned a driving force can excite a +specific normal mode right so if you + + align:start position:0% +specific normal mode right so if you + + + align:start position:0% +specific normal mode right so if you +type the system at the frequency + + align:start position:0% +type the system at the frequency + + + align:start position:0% +type the system at the frequency +persistent like then the system will + + align:start position:0% +persistent like then the system will + + + align:start position:0% +persistent like then the system will +respond and the other day at driving + + align:start position:0% +respond and the other day at driving + + + align:start position:0% +respond and the other day at driving +frequency with large amplitude okay and + + align:start position:0% +frequency with large amplitude okay and + + + align:start position:0% +frequency with large amplitude okay and +also we have learned that the full + + align:start position:0% +also we have learned that the full + + + align:start position:0% +also we have learned that the full +solution of a coupled oscillator is + + align:start position:0% +solution of a coupled oscillator is + + + align:start position:0% +solution of a coupled oscillator is +actually pretty similar to the situation + + align:start position:0% +actually pretty similar to the situation + + + align:start position:0% +actually pretty similar to the situation +we got from single oscillator so you + + align:start position:0% +we got from single oscillator so you + + + align:start position:0% +we got from single oscillator so you +have particular solution and homogeneous + + align:start position:0% +have particular solution and homogeneous + + + align:start position:0% +have particular solution and homogeneous +solution and the full solution will be a + + align:start position:0% +solution and the full solution will be a + + + align:start position:0% +solution and the full solution will be a +superposition of the two country + + align:start position:0% +superposition of the two country + + + align:start position:0% +superposition of the two country +component and all the unknown + + align:start position:0% +component and all the unknown + + + align:start position:0% +component and all the unknown +coefficients are in the homogenous part + + align:start position:0% +coefficients are in the homogenous part + + + align:start position:0% +coefficients are in the homogenous part +of the solution + + align:start position:0% +of the solution + + + align:start position:0% +of the solution +okay and today I hope I can help you and + + align:start position:0% +okay and today I hope I can help you and + + + align:start position:0% +okay and today I hope I can help you and +convince you that symmetry actually can + + align:start position:0% +convince you that symmetry actually can + + + align:start position:0% +convince you that symmetry actually can +help us to solve the normal modes + + align:start position:0% +help us to solve the normal modes + + + align:start position:0% +help us to solve the normal modes +without knowing the detail or a nice one + + align:start position:0% +without knowing the detail or a nice one + + + align:start position:0% +without knowing the detail or a nice one +make a matrix actually so that is + + align:start position:0% +make a matrix actually so that is + + + align:start position:0% +make a matrix actually so that is +actually something really cool and I + + align:start position:0% +actually something really cool and I + + + align:start position:0% +actually something really cool and I +would like to talk about that in this + + align:start position:0% +would like to talk about that in this + + + align:start position:0% +would like to talk about that in this +lecture today so this is actually what + + align:start position:0% +lecture today so this is actually what + + + align:start position:0% +lecture today so this is actually what +we have been doing so far right so we + + align:start position:0% +we have been doing so far right so we + + + align:start position:0% +we have been doing so far right so we +write everything in terms of matrix so + + align:start position:0% +write everything in terms of matrix so + + + align:start position:0% +write everything in terms of matrix so +we start from the equation of motion and + + align:start position:0% +we start from the equation of motion and + + + align:start position:0% +we start from the equation of motion and +X double dot equal to minus KX and then + + align:start position:0% +X double dot equal to minus KX and then + + + align:start position:0% +X double dot equal to minus KX and then +we write everything in a complex + + align:start position:0% +we write everything in a complex + + + align:start position:0% +we write everything in a complex +notation exponential I Omega T plus Phi + + align:start position:0% +notation exponential I Omega T plus Phi + + + align:start position:0% +notation exponential I Omega T plus Phi +times a a they should be back to right + + align:start position:0% +times a a they should be back to right + + + align:start position:0% +times a a they should be back to right +so it's actually a 1 a 2 a series it + + align:start position:0% +so it's actually a 1 a 2 a series it + + + align:start position:0% +so it's actually a 1 a 2 a series it +says with the amplitude of the + + align:start position:0% +says with the amplitude of the + + + align:start position:0% +says with the amplitude of the +oscillation of the first second and + + align:start position:0% +oscillation of the first second and + + + align:start position:0% +oscillation of the first second and +third etcetera I said to a component of + + align:start position:0% +third etcetera I said to a component of + + + align:start position:0% +third etcetera I said to a component of +the system right then we actually found + + align:start position:0% +the system right then we actually found + + + align:start position:0% +the system right then we actually found +that in the end of the day we are + + align:start position:0% +that in the end of the day we are + + + align:start position:0% +that in the end of the day we are +actually solving this problem like + + align:start position:0% +actually solving this problem like + + + align:start position:0% +actually solving this problem like +eigenvalue problem right so basically we + + align:start position:0% +eigenvalue problem right so basically we + + + align:start position:0% +eigenvalue problem right so basically we +have M minus 1 K matrix describe how + + align:start position:0% +have M minus 1 K matrix describe how + + + align:start position:0% +have M minus 1 K matrix describe how +each component in the system interact + + align:start position:0% +each component in the system interact + + + align:start position:0% +each component in the system interact +with each other okay then what is this + + align:start position:0% +with each other okay then what is this + + + align:start position:0% +with each other okay then what is this +with the angular frequency of the normal + + align:start position:0% +with the angular frequency of the normal + + + align:start position:0% +with the angular frequency of the normal +modes essentially coming from this + + align:start position:0% +modes essentially coming from this + + + align:start position:0% +modes essentially coming from this +eigenvalue problem M minus 1 K a equal + + align:start position:0% +eigenvalue problem M minus 1 K a equal + + + align:start position:0% +eigenvalue problem M minus 1 K a equal +to Omega square a then you just go ahead + + align:start position:0% +to Omega square a then you just go ahead + + + align:start position:0% +to Omega square a then you just go ahead +and solve the eigenvalue problem then + + align:start position:0% +and solve the eigenvalue problem then + + + align:start position:0% +and solve the eigenvalue problem then +you will be able to figure out what are + + align:start position:0% +you will be able to figure out what are + + + align:start position:0% +you will be able to figure out what are +the normal mode frequencies and + + align:start position:0% +the normal mode frequencies and + + + align:start position:0% +the normal mode frequencies and +therefore what are the relative the + + align:start position:0% +therefore what are the relative the + + + align:start position:0% +therefore what are the relative the +ratio of the amplitude in the normal + + align:start position:0% +ratio of the amplitude in the normal + + + align:start position:0% +ratio of the amplitude in the normal +mode which is actually a vector okay the + + align:start position:0% +mode which is actually a vector okay the + + + align:start position:0% +mode which is actually a vector okay the +eye contact okay so that's issue what we + + align:start position:0% +eye contact okay so that's issue what we + + + align:start position:0% +eye contact okay so that's issue what we +have been doing okay and today what I am + + align:start position:0% +have been doing okay and today what I am + + + align:start position:0% +have been doing okay and today what I am +going to do is to introduce you a very + + align:start position:0% +going to do is to introduce you a very + + + align:start position:0% +going to do is to introduce you a very +important concept in physics not only in + + align:start position:0% +important concept in physics not only in + + + align:start position:0% +important concept in physics not only in +physics but also in mathematics and also + + align:start position:0% +physics but also in mathematics and also + + + align:start position:0% +physics but also in mathematics and also +art right so you see symmetry in the art + + align:start position:0% +art right so you see symmetry in the art + + + align:start position:0% +art right so you see symmetry in the art +you can see here there are several + + align:start position:0% +you can see here there are several + + + align:start position:0% +you can see here there are several +graphs here and you can see that there + + align:start position:0% +graphs here and you can see that there + + + align:start position:0% +graphs here and you can see that there +the parent symmetry you have rotational + + align:start position:0% +the parent symmetry you have rotational + + + align:start position:0% +the parent symmetry you have rotational +symmetry + + align:start position:0% + + + + align:start position:0% + +they are your fracturing symmetry and + + align:start position:0% +they are your fracturing symmetry and + + + align:start position:0% +they are your fracturing symmetry and +you can see that when we build the + + align:start position:0% +you can see that when we build the + + + align:start position:0% +you can see that when we build the +particle detector visible lower-right + + align:start position:0% +particle detector visible lower-right + + + align:start position:0% +particle detector visible lower-right +bra is a cns detector camera so noise in + + align:start position:0% +bra is a cns detector camera so noise in + + + align:start position:0% +bra is a cns detector camera so noise in +the Large Hadron Collider we also try to + + align:start position:0% +the Large Hadron Collider we also try to + + + align:start position:0% +the Large Hadron Collider we also try to +build this detector symmetric right + + align:start position:0% +build this detector symmetric right + + + align:start position:0% +build this detector symmetric right +because otherwise if I get a very + + align:start position:0% +because otherwise if I get a very + + + align:start position:0% +because otherwise if I get a very +complicated shape of the data then the + + align:start position:0% +complicated shape of the data then the + + + align:start position:0% +complicated shape of the data then the +analysis of the data will be really + + align:start position:0% +analysis of the data will be really + + + align:start position:0% +analysis of the data will be really +complicated + + align:start position:0% +complicated + + + align:start position:0% +complicated +so therefore everybody like symmetry and + + align:start position:0% +so therefore everybody like symmetry and + + + align:start position:0% +so therefore everybody like symmetry and +everybody don't like really chaos right + + align:start position:0% +everybody don't like really chaos right + + + align:start position:0% +everybody don't like really chaos right +okay so that's really nice + + align:start position:0% +okay so that's really nice + + + align:start position:0% +okay so that's really nice +the question is how do we speak the + + align:start position:0% +the question is how do we speak the + + + align:start position:0% +the question is how do we speak the +language not let the natural speak how + + align:start position:0% +language not let the natural speak how + + + align:start position:0% +language not let the natural speak how +do we actually describe symmetry that's + + align:start position:0% +do we actually describe symmetry that's + + + align:start position:0% +do we actually describe symmetry that's +actually the question I'm asking and I'm + + align:start position:0% +actually the question I'm asking and I'm + + + align:start position:0% +actually the question I'm asking and I'm +going to show you that okay we can issue + + align:start position:0% +going to show you that okay we can issue + + + align:start position:0% +going to show you that okay we can issue +use mathematics to describe a symmetry + + align:start position:0% +use mathematics to describe a symmetry + + + align:start position:0% +use mathematics to describe a symmetry +so before we go to infinite number of + + align:start position:0% +so before we go to infinite number of + + + align:start position:0% +so before we go to infinite number of +oscillator that me give you a concrete + + align:start position:0% +oscillator that me give you a concrete + + + align:start position:0% +oscillator that me give you a concrete +example of symmetry and then see if we + + align:start position:0% +example of symmetry and then see if we + + + align:start position:0% +example of symmetry and then see if we +can understand how to use the math to + + align:start position:0% +can understand how to use the math to + + + align:start position:0% +can understand how to use the math to +describe symmetry okay so there's a two + + align:start position:0% +describe symmetry okay so there's a two + + + align:start position:0% +describe symmetry okay so there's a two +component system two pendulums which we + + align:start position:0% +component system two pendulums which we + + + align:start position:0% +component system two pendulums which we +work together in the last few lectures + + align:start position:0% +work together in the last few lectures + + + align:start position:0% +work together in the last few lectures +that they are coupled to each other + + align:start position:0% +that they are coupled to each other + + + align:start position:0% +that they are coupled to each other +and there is a parent symmetry of this + + align:start position:0% +and there is a parent symmetry of this + + + align:start position:0% +and there is a parent symmetry of this +system can somebody tell me what is the + + align:start position:0% +system can somebody tell me what is the + + + align:start position:0% +system can somebody tell me what is the +same symmetry you can see from this + + align:start position:0% +same symmetry you can see from this + + + align:start position:0% +same symmetry you can see from this +system somebody anybody + + align:start position:0% + + + + align:start position:0% + +so if you refract this system as I show + + align:start position:0% +so if you refract this system as I show + + + align:start position:0% +so if you refract this system as I show +you in the leg in that slide you can see + + align:start position:0% +you in the leg in that slide you can see + + + align:start position:0% +you in the leg in that slide you can see +that if you reflect this picture it + + align:start position:0% +that if you reflect this picture it + + + align:start position:0% +that if you reflect this picture it +looks identical right so that is + + align:start position:0% +looks identical right so that is + + + align:start position:0% +looks identical right so that is +actually really good news + + align:start position:0% +actually really good news + + + align:start position:0% +actually really good news +that means if I do this in refraction x1 + + align:start position:0% +that means if I do this in refraction x1 + + + align:start position:0% +that means if I do this in refraction x1 +go to minus x2 you have a minus sign + + align:start position:0% +go to minus x2 you have a minus sign + + + align:start position:0% +go to minus x2 you have a minus sign +because you can see that you have the + + align:start position:0% +because you can see that you have the + + + align:start position:0% +because you can see that you have the +refraction the amplitude change sign + + align:start position:0% +refraction the amplitude change sign + + + align:start position:0% +refraction the amplitude change sign +right x2 co 2 minus x1 the system looks + + align:start position:0% +right x2 co 2 minus x1 the system looks + + + align:start position:0% +right x2 co 2 minus x1 the system looks +identical and the physics should not + + align:start position:0% +identical and the physics should not + + + align:start position:0% +identical and the physics should not +change okay so that's actually what we + + align:start position:0% +change okay so that's actually what we + + + align:start position:0% +change okay so that's actually what we +can learn from but there so that means + + align:start position:0% +can learn from but there so that means + + + align:start position:0% +can learn from but there so that means +if I have I to this refraction then I + + align:start position:0% +if I have I to this refraction then I + + + align:start position:0% +if I have I to this refraction then I +can have actually defined X tilde P this + + align:start position:0% +can have actually defined X tilde P this + + + align:start position:0% +can have actually defined X tilde P this +is equal to minus x2 minus x1 okay to be + + align:start position:0% +is equal to minus x2 minus x1 okay to be + + + align:start position:0% +is equal to minus x2 minus x1 okay to be +with eggs okay and this is also going to + + align:start position:0% +with eggs okay and this is also going to + + + align:start position:0% +with eggs okay and this is also going to +be the solution of the equation of + + align:start position:0% +be the solution of the equation of + + + align:start position:0% +be the solution of the equation of +motion if the original X is already a + + align:start position:0% +motion if the original X is already a + + + align:start position:0% +motion if the original X is already a +solution okay so that's the power of the + + align:start position:0% +solution okay so that's the power of the + + + align:start position:0% +solution okay so that's the power of the +refraction symmetry okay if X is a + + align:start position:0% +refraction symmetry okay if X is a + + + align:start position:0% +refraction symmetry okay if X is a +solution then I do this refraction and I + + align:start position:0% +solution then I do this refraction and I + + + align:start position:0% +solution then I do this refraction and I +can figure out that X tilde is also a + + align:start position:0% +can figure out that X tilde is also a + + + align:start position:0% +can figure out that X tilde is also a +solution okay so how do I actually how + + align:start position:0% +solution okay so how do I actually how + + + align:start position:0% +solution okay so how do I actually how +do I actually describe the symmetry in + + align:start position:0% +do I actually describe the symmetry in + + + align:start position:0% +do I actually describe the symmetry in +the form of mathematics what we actually + + align:start position:0% +the form of mathematics what we actually + + + align:start position:0% +the form of mathematics what we actually +do is to define s-matrix symmetry matrix + + align:start position:0% +do is to define s-matrix symmetry matrix + + + align:start position:0% +do is to define s-matrix symmetry matrix +and in this case when we talk about + + align:start position:0% +and in this case when we talk about + + + align:start position:0% +and in this case when we talk about +reflection symmetry is actually defined + + align:start position:0% +reflection symmetry is actually defined + + + align:start position:0% +reflection symmetry is actually defined +as 0 minus 1 minus 1 0 this is actually + + align:start position:0% +as 0 minus 1 minus 1 0 this is actually + + + align:start position:0% +as 0 minus 1 minus 1 0 this is actually +a 2 by 2 matrix and if I do this + + align:start position:0% +a 2 by 2 matrix and if I do this + + + align:start position:0% +a 2 by 2 matrix and if I do this +operation s operation this X matrix then + + align:start position:0% +operation s operation this X matrix then + + + align:start position:0% +operation s operation this X matrix then +that especially going to give you the X + + align:start position:0% +that especially going to give you the X + + + align:start position:0% +that especially going to give you the X +tilde okay so that's the issue the the + + align:start position:0% +tilde okay so that's the issue the the + + + align:start position:0% +tilde okay so that's the issue the the +row of the symmetry matrix ok any + + align:start position:0% +row of the symmetry matrix ok any + + + align:start position:0% +row of the symmetry matrix ok any +questions ok so now we have defined a + + align:start position:0% +questions ok so now we have defined a + + + align:start position:0% +questions ok so now we have defined a +symmetry matrix and though then you can + + align:start position:0% +symmetry matrix and though then you can + + + align:start position:0% +symmetry matrix and though then you can +ask why do we as you care and why do we + + align:start position:0% +ask why do we as you care and why do we + + + align:start position:0% +ask why do we as you care and why do we +actually introduce symmetry matrix right + + align:start position:0% +actually introduce symmetry matrix right + + + align:start position:0% +actually introduce symmetry matrix right +because I can always write down the X + + align:start position:0% +because I can always write down the X + + + align:start position:0% +because I can always write down the X +tilde in that way that is because I + + align:start position:0% +tilde in that way that is because I + + + align:start position:0% +tilde in that way that is because I +think by the end of this lecture you + + align:start position:0% +think by the end of this lecture you + + + align:start position:0% +think by the end of this lecture you +you'll find that if s matrix describe + + align:start position:0% +you'll find that if s matrix describe + + + align:start position:0% +you'll find that if s matrix describe +the symmetry of the system ok + + align:start position:0% +the symmetry of the system ok + + + align:start position:0% +the symmetry of the system ok +that will mean as matrix will come mute + + align:start position:0% +that will mean as matrix will come mute + + + align:start position:0% +that will mean as matrix will come mute +with ms1 key metrics which you don't + + align:start position:0% +with ms1 key metrics which you don't + + + align:start position:0% +with ms1 key metrics which you don't +know commute yet but I will introduce + + align:start position:0% +know commute yet but I will introduce + + + align:start position:0% +know commute yet but I will introduce +you that means n minus 1 K metric and s + + align:start position:0% +you that means n minus 1 K metric and s + + + align:start position:0% +you that means n minus 1 K metric and s +can actually swap Freedy okay if that + + align:start position:0% +can actually swap Freedy okay if that + + + align:start position:0% +can actually swap Freedy okay if that +happens then s matrix will share the + + align:start position:0% +happens then s matrix will share the + + + align:start position:0% +happens then s matrix will share the +same sets of eigenvectors + + align:start position:0% +same sets of eigenvectors + + + align:start position:0% +same sets of eigenvectors +as the N minus 1 K metrics what does + + align:start position:0% +as the N minus 1 K metrics what does + + + align:start position:0% +as the N minus 1 K metrics what does +that mean that means okay before we're + + align:start position:0% +that mean that means okay before we're + + + align:start position:0% +that mean that means okay before we're +doing this solution right we are solving + + align:start position:0% +doing this solution right we are solving + + + align:start position:0% +doing this solution right we are solving +n minus 1 K matrix eigen value problem + + align:start position:0% +n minus 1 K matrix eigen value problem + + + align:start position:0% +n minus 1 K matrix eigen value problem +right and then we get an eigen vector + + align:start position:0% +right and then we get an eigen vector + + + align:start position:0% +right and then we get an eigen vector +which is the amplitude ratio of normal + + align:start position:0% +which is the amplitude ratio of normal + + + align:start position:0% +which is the amplitude ratio of normal +modes and that means you have an + + align:start position:0% +modes and that means you have an + + + align:start position:0% +modes and that means you have an +alternative way to get the normal mode + + align:start position:0% +alternative way to get the normal mode + + + align:start position:0% +alternative way to get the normal mode +you can solve the eigen value problem of + + align:start position:0% +you can solve the eigen value problem of + + + align:start position:0% +you can solve the eigen value problem of +asthmatics + + align:start position:0% +asthmatics + + + align:start position:0% +asthmatics +then you can get the same set of + + align:start position:0% +then you can get the same set of + + + align:start position:0% +then you can get the same set of +amplitude ratios as M minus 1 made ok + + align:start position:0% +amplitude ratios as M minus 1 made ok + + + align:start position:0% +amplitude ratios as M minus 1 made ok +matrix eigenvalue problem okay and that + + align:start position:0% +matrix eigenvalue problem okay and that + + + align:start position:0% +matrix eigenvalue problem okay and that +usually the eigenvalue problem of s + + align:start position:0% +usually the eigenvalue problem of s + + + align:start position:0% +usually the eigenvalue problem of s +matrix it's far much easier than n minus + + align:start position:0% +matrix it's far much easier than n minus + + + align:start position:0% +matrix it's far much easier than n minus +1 K matrix ok so that's actually why we + + align:start position:0% +1 K matrix ok so that's actually why we + + + align:start position:0% +1 K matrix ok so that's actually why we +are doing this ok so now I would like to + + align:start position:0% +are doing this ok so now I would like to + + + align:start position:0% +are doing this ok so now I would like to +convince you that s matrix and M minus 1 + + align:start position:0% +convince you that s matrix and M minus 1 + + + align:start position:0% +convince you that s matrix and M minus 1 +K matrix will share I come back + + align:start position:0% + + + + align:start position:0% + +okay so let's go ahead and prove this or + + align:start position:0% +okay so let's go ahead and prove this or + + + align:start position:0% +okay so let's go ahead and prove this or +demonstrate this idea okay so the + + align:start position:0% +demonstrate this idea okay so the + + + align:start position:0% +demonstrate this idea okay so the +original equation motion looks like this + + align:start position:0% +original equation motion looks like this + + + align:start position:0% +original equation motion looks like this +X double dot okay equal to n minus 1 K X + + align:start position:0% +X double dot okay equal to n minus 1 K X + + + align:start position:0% +X double dot okay equal to n minus 1 K X +right so that is actually the original + + align:start position:0% +right so that is actually the original + + + align:start position:0% +right so that is actually the original +equation of motion okay and if this + + align:start position:0% +equation of motion okay and if this + + + align:start position:0% +equation of motion okay and if this +system satisfy the refraction symmetry + + align:start position:0% +system satisfy the refraction symmetry + + + align:start position:0% +system satisfy the refraction symmetry +that means X tilde is also a solution + + align:start position:0% +that means X tilde is also a solution + + + align:start position:0% +that means X tilde is also a solution +right therefore what does that mean that + + align:start position:0% +right therefore what does that mean that + + + align:start position:0% +right therefore what does that mean that +means X tilde power dot will be also + + align:start position:0% +means X tilde power dot will be also + + + align:start position:0% +means X tilde power dot will be also +equal to M s 1 K X because it's also a + + align:start position:0% +equal to M s 1 K X because it's also a + + + align:start position:0% +equal to M s 1 K X because it's also a +solution to the equation of motion right + + align:start position:0% +solution to the equation of motion right + + + align:start position:0% +solution to the equation of motion right +that's a pretty nature okay now I can + + align:start position:0% +that's a pretty nature okay now I can + + + align:start position:0% +that's a pretty nature okay now I can +actually use this expression X tilde is + + align:start position:0% +actually use this expression X tilde is + + + align:start position:0% +actually use this expression X tilde is +equal to s times X right those things + + align:start position:0% +equal to s times X right those things + + + align:start position:0% +equal to s times X right those things +are metrics okay just to be careful okay + + align:start position:0% +are metrics okay just to be careful okay + + + align:start position:0% +are metrics okay just to be careful okay +that means I can write this like this s + + align:start position:0% +that means I can write this like this s + + + align:start position:0% +that means I can write this like this s +X double dot equal to n minus 1 K s ok + + align:start position:0% +X double dot equal to n minus 1 K s ok + + + align:start position:0% +X double dot equal to n minus 1 K s ok +there's no matrix I can also replace I'm + + align:start position:0% +there's no matrix I can also replace I'm + + + align:start position:0% +there's no matrix I can also replace I'm +just replacing X tilde by SX ok + + align:start position:0% +just replacing X tilde by SX ok + + + align:start position:0% +just replacing X tilde by SX ok +and also I call this su one I call this + + align:start position:0% +and also I call this su one I call this + + + align:start position:0% +and also I call this su one I call this +as u - ok I can multiply X from the left + + align:start position:0% +as u - ok I can multiply X from the left + + + align:start position:0% +as u - ok I can multiply X from the left +hand side of one okay and see what will + + align:start position:0% +hand side of one okay and see what will + + + align:start position:0% +hand side of one okay and see what will +happen so if I do that then what I am + + align:start position:0% +happen so if I do that then what I am + + + align:start position:0% +happen so if I do that then what I am +going to get is s X double dot ok that + + align:start position:0% +going to get is s X double dot ok that + + + align:start position:0% +going to get is s X double dot ok that +would be equal to s n minus 1 K X + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay if you compare this equation and + + align:start position:0% +okay if you compare this equation and + + + align:start position:0% +okay if you compare this equation and +the equation number three this two + + align:start position:0% +the equation number three this two + + + align:start position:0% +the equation number three this two +equation you will see that lap inside is + + align:start position:0% +equation you will see that lap inside is + + + align:start position:0% +equation you will see that lap inside is +the same right right hand side huh + + align:start position:0% +the same right right hand side huh + + + align:start position:0% +the same right right hand side huh +something interesting is happening + + align:start position:0% +something interesting is happening + + + align:start position:0% +something interesting is happening +Emmons 1k s must be equal to s and minus + + align:start position:0% +Emmons 1k s must be equal to s and minus + + + align:start position:0% +Emmons 1k s must be equal to s and minus +one tape right what does that mean this + + align:start position:0% +one tape right what does that mean this + + + align:start position:0% +one tape right what does that mean this +means that they understand a minus 1 K s + + align:start position:0% +means that they understand a minus 1 K s + + + align:start position:0% +means that they understand a minus 1 K s +is equal to s M minus 1 K so if I say + + align:start position:0% +is equal to s M minus 1 K so if I say + + + align:start position:0% +is equal to s M minus 1 K so if I say +this system satisfies a symmetry it is + + align:start position:0% +this system satisfies a symmetry it is + + + align:start position:0% +this system satisfies a symmetry it is +quite 5s metrics that means X tilde + + align:start position:0% +quite 5s metrics that means X tilde + + + align:start position:0% +quite 5s metrics that means X tilde +which essentially the transformed + + align:start position:0% +which essentially the transformed + + + align:start position:0% +which essentially the transformed +amplitude will be also a solution to the + + align:start position:0% +amplitude will be also a solution to the + + + align:start position:0% +amplitude will be also a solution to the +equation of motion and therefore an + + align:start position:0% +equation of motion and therefore an + + + align:start position:0% +equation of motion and therefore an +inevitable consequence is that M minus 1 + + align:start position:0% +inevitable consequence is that M minus 1 + + + align:start position:0% +inevitable consequence is that M minus 1 +K s will be equal to s ms 1k usually + + align:start position:0% +K s will be equal to s ms 1k usually + + + align:start position:0% +K s will be equal to s ms 1k usually +when you start the physics we write this + + align:start position:0% +when you start the physics we write this + + + align:start position:0% +when you start the physics we write this +in terms of communicator okay so we call + + align:start position:0% +in terms of communicator okay so we call + + + align:start position:0% +in terms of communicator okay so we call +this as these two things as you commute + + align:start position:0% +this as these two things as you commute + + + align:start position:0% +this as these two things as you commute +okay so communicator is actually defined + + align:start position:0% +okay so communicator is actually defined + + + align:start position:0% +okay so communicator is actually defined +as a bracket of a and B this is a should + + align:start position:0% +as a bracket of a and B this is a should + + + align:start position:0% +as a bracket of a and B this is a should +equal defined us ap minus VA okay if if + + align:start position:0% +equal defined us ap minus VA okay if if + + + align:start position:0% +equal defined us ap minus VA okay if if +a and the P commute okay it's just new + + align:start position:0% +a and the P commute okay it's just new + + + align:start position:0% +a and the P commute okay it's just new +word probably for most of you if they + + align:start position:0% +word probably for most of you if they + + + align:start position:0% +word probably for most of you if they +can mute that means a see in the bracket + + align:start position:0% +can mute that means a see in the bracket + + + align:start position:0% +can mute that means a see in the bracket +is equal to 0 okay so this expression I + + align:start position:0% +is equal to 0 okay so this expression I + + + align:start position:0% +is equal to 0 okay so this expression I +can actually write it down like this + + align:start position:0% +can actually write it down like this + + + align:start position:0% +can actually write it down like this +commutator of s M minus 1 K that is + + align:start position:0% +commutator of s M minus 1 K that is + + + align:start position:0% +commutator of s M minus 1 K that is +equal to 0 and you will see this really + + align:start position:0% +equal to 0 and you will see this really + + + align:start position:0% +equal to 0 and you will see this really +a lot when you study quantum physics + + align:start position:0% +a lot when you study quantum physics + + + align:start position:0% +a lot when you study quantum physics +okay so I hope this I should give you + + align:start position:0% +okay so I hope this I should give you + + + align:start position:0% +okay so I hope this I should give you +some flavor about commutator okay so now + + align:start position:0% +some flavor about commutator okay so now + + + align:start position:0% +some flavor about commutator okay so now +that's actually pretty nice + + align:start position:0% +that's actually pretty nice + + + align:start position:0% +that's actually pretty nice +this means that like commute okay if I + + align:start position:0% +this means that like commute okay if I + + + align:start position:0% +this means that like commute okay if I +take X of T this is equal to a 1 cosine + + align:start position:0% +take X of T this is equal to a 1 cosine + + + align:start position:0% +take X of T this is equal to a 1 cosine +Omega 1 okay so this means that a is + + align:start position:0% +Omega 1 okay so this means that a is + + + align:start position:0% +Omega 1 okay so this means that a is +actually in sorry X is actually a + + align:start position:0% +actually in sorry X is actually a + + + align:start position:0% +actually in sorry X is actually a +solution which is a normal mode a + + align:start position:0% +solution which is a normal mode a + + + align:start position:0% +solution which is a normal mode a +solution right and a is actually + + align:start position:0% +solution right and a is actually + + + align:start position:0% +solution right and a is actually +amplitude the vector the the amplitude + + align:start position:0% +amplitude the vector the the amplitude + + + align:start position:0% +amplitude the vector the the amplitude +factor over the first normal mode and + + align:start position:0% +factor over the first normal mode and + + + align:start position:0% +factor over the first normal mode and +Omega 1 is actually the first normal + + align:start position:0% +Omega 1 is actually the first normal + + + align:start position:0% +Omega 1 is actually the first normal +frequency okay if this is the case okay + + align:start position:0% +frequency okay if this is the case okay + + + align:start position:0% +frequency okay if this is the case okay +then I will have X tilde of T will be + + align:start position:0% +then I will have X tilde of T will be + + + align:start position:0% +then I will have X tilde of T will be +also proportional to a 1 cosine Omega 1t + + align:start position:0% +also proportional to a 1 cosine Omega 1t + + + align:start position:0% +also proportional to a 1 cosine Omega 1t +right because if I actually exchange x1 + + align:start position:0% +right because if I actually exchange x1 + + + align:start position:0% +right because if I actually exchange x1 +x2 their answer that same frequency is + + align:start position:0% +x2 their answer that same frequency is + + + align:start position:0% +x2 their answer that same frequency is +not going to change right therefore + + align:start position:0% +not going to change right therefore + + + align:start position:0% +not going to change right therefore +since this system is in the same normal + + align:start position:0% +since this system is in the same normal + + + align:start position:0% +since this system is in the same normal +mode with angular frequency Omega 1 + + align:start position:0% +mode with angular frequency Omega 1 + + + align:start position:0% +mode with angular frequency Omega 1 +therefore the amplitude ratio of the + + align:start position:0% +therefore the amplitude ratio of the + + + align:start position:0% +therefore the amplitude ratio of the +first and second oscillator will stay + + align:start position:0% +first and second oscillator will stay + + + align:start position:0% +first and second oscillator will stay +constant right because you are in one of + + align:start position:0% +constant right because you are in one of + + + align:start position:0% +constant right because you are in one of +the normal mode right therefore I can + + align:start position:0% +the normal mode right therefore I can + + + align:start position:0% +the normal mode right therefore I can +conclude that X tilde it's going to be + + align:start position:0% +conclude that X tilde it's going to be + + + align:start position:0% +conclude that X tilde it's going to be +proportional to this expression because + + align:start position:0% +proportional to this expression because + + + align:start position:0% +proportional to this expression because +they are innocent normal mode + + align:start position:0% +they are innocent normal mode + + + align:start position:0% +they are innocent normal mode +oscillating at the same frequency okay + + align:start position:0% +oscillating at the same frequency okay + + + align:start position:0% +oscillating at the same frequency okay +is that too fast everybody is following + + align:start position:0% +is that too fast everybody is following + + + align:start position:0% +is that too fast everybody is following +ok so that's nice + + align:start position:0% +ok so that's nice + + + align:start position:0% +ok so that's nice +so this means that SX + + align:start position:0% +so this means that SX + + + align:start position:0% +so this means that SX +teehee okay will be equal to s a1 cosine + + align:start position:0% +teehee okay will be equal to s a1 cosine + + + align:start position:0% +teehee okay will be equal to s a1 cosine +Omega 1 P okay so this is actually + + align:start position:0% +Omega 1 P okay so this is actually + + + align:start position:0% +Omega 1 P okay so this is actually +coming from here right I am repressing + + align:start position:0% +coming from here right I am repressing + + + align:start position:0% +coming from here right I am repressing +so I am decreasing X tilde is X based on + + align:start position:0% +so I am decreasing X tilde is X based on + + + align:start position:0% +so I am decreasing X tilde is X based on +this definition okay + + align:start position:0% +this definition okay + + + align:start position:0% +this definition okay +then again I'd replace I write X + + align:start position:0% +then again I'd replace I write X + + + align:start position:0% +then again I'd replace I write X +explicitly which is 1/8 cosine Omega 1t + + align:start position:0% +explicitly which is 1/8 cosine Omega 1t + + + align:start position:0% +explicitly which is 1/8 cosine Omega 1t +okay then you get this expression and + + align:start position:0% +okay then you get this expression and + + + align:start position:0% +okay then you get this expression and +from this above the expression above you + + align:start position:0% +from this above the expression above you + + + align:start position:0% +from this above the expression above you +see that we will conclude that this is + + align:start position:0% +see that we will conclude that this is + + + align:start position:0% +see that we will conclude that this is +proportional to a1 cosine Omega 1t + + align:start position:0% +proportional to a1 cosine Omega 1t + + + align:start position:0% +proportional to a1 cosine Omega 1t +that's very nice that means s a cosine + + align:start position:0% +that's very nice that means s a cosine + + + align:start position:0% +that's very nice that means s a cosine +Omega 1 T is proportional to a1 cosine + + align:start position:0% +Omega 1 T is proportional to a1 cosine + + + align:start position:0% +Omega 1 T is proportional to a1 cosine +Omega P and you can actually I cancel + + align:start position:0% +Omega P and you can actually I cancel + + + align:start position:0% +Omega P and you can actually I cancel +this now you see that as a 1 is + + align:start position:0% +this now you see that as a 1 is + + + align:start position:0% +this now you see that as a 1 is +proportional to a 1 or I can write it as + + align:start position:0% +proportional to a 1 or I can write it as + + + align:start position:0% +proportional to a 1 or I can write it as +as a 1 is equal to theta what does that + + align:start position:0% +as a 1 is equal to theta what does that + + + align:start position:0% +as a 1 is equal to theta what does that +mean + + align:start position:0% +mean + + + align:start position:0% +mean +this means that a 1 okay originally what + + align:start position:0% +this means that a 1 okay originally what + + + align:start position:0% +this means that a 1 okay originally what +with a one coming from a 1 is the + + align:start position:0% +with a one coming from a 1 is the + + + align:start position:0% +with a one coming from a 1 is the +amplitude of all the components in the + + align:start position:0% +amplitude of all the components in the + + + align:start position:0% +amplitude of all the components in the +first normal mode right that's coming + + align:start position:0% +first normal mode right that's coming + + + align:start position:0% +first normal mode right that's coming +from the eigenvalue problem which we + + align:start position:0% +from the eigenvalue problem which we + + + align:start position:0% +from the eigenvalue problem which we +actually does in this slide I can value + + align:start position:0% +actually does in this slide I can value + + + align:start position:0% +actually does in this slide I can value +problem MS 1 ka equal to Omega square a + + align:start position:0% +problem MS 1 ka equal to Omega square a + + + align:start position:0% +problem MS 1 ka equal to Omega square a +will give you the solution of normal + + align:start position:0% +will give you the solution of normal + + + align:start position:0% +will give you the solution of normal +mode and there are vectors which is an + + align:start position:0% +mode and there are vectors which is an + + + align:start position:0% +mode and there are vectors which is an +amplitude ratios of all the components + + align:start position:0% +amplitude ratios of all the components + + + align:start position:0% +amplitude ratios of all the components +in the system right so that means a1 is + + align:start position:0% +in the system right so that means a1 is + + + align:start position:0% +in the system right so that means a1 is +not only n minus 1 K matrix eigen + + align:start position:0% +not only n minus 1 K matrix eigen + + + align:start position:0% +not only n minus 1 K matrix eigen +vectors it's also eigen vector of s + + align:start position:0% +vectors it's also eigen vector of s + + + align:start position:0% +vectors it's also eigen vector of s +matrix ok + + align:start position:0% +matrix ok + + + align:start position:0% +matrix ok +so that is actually a very good news and + + align:start position:0% +so that is actually a very good news and + + + align:start position:0% +so that is actually a very good news and +I can also do the same thing for a tool + + align:start position:0% +I can also do the same thing for a tool + + + align:start position:0% +I can also do the same thing for a tool +to prove that it also worked for a to + + align:start position:0% +to prove that it also worked for a to + + + align:start position:0% +to prove that it also worked for a to +activation is identical so I am NOT + + align:start position:0% +activation is identical so I am NOT + + + align:start position:0% +activation is identical so I am NOT +going to do that again so that means + + align:start position:0% +going to do that again so that means + + + align:start position:0% +going to do that again so that means +actually starting from starting from + + align:start position:0% +actually starting from starting from + + + align:start position:0% +actually starting from starting from +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +if X and X tilde oppose solution to the + + align:start position:0% +if X and X tilde oppose solution to the + + + align:start position:0% +if X and X tilde oppose solution to the +equation motion okay I will conclude + + align:start position:0% +equation motion okay I will conclude + + + align:start position:0% +equation motion okay I will conclude +that as matrix and the N minus 1 K + + align:start position:0% +that as matrix and the N minus 1 K + + + align:start position:0% +that as matrix and the N minus 1 K +matrix they commute + + align:start position:0% +matrix they commute + + + align:start position:0% +matrix they commute +okay to how to tell if assistance + + align:start position:0% +okay to how to tell if assistance + + + align:start position:0% +okay to how to tell if assistance +satisfy a specific symmetry defined by + + align:start position:0% +satisfy a specific symmetry defined by + + + align:start position:0% +satisfy a specific symmetry defined by +my symmetry metrics in spite this way + + align:start position:0% +my symmetry metrics in spite this way + + + align:start position:0% +my symmetry metrics in spite this way +you can check if M is 1 K and the S + + align:start position:0% +you can check if M is 1 K and the S + + + align:start position:0% +you can check if M is 1 K and the S +commute if they commute that means this + + align:start position:0% +commute if they commute that means this + + + align:start position:0% +commute if they commute that means this +system actually satisfy this symmetry + + align:start position:0% +system actually satisfy this symmetry + + + align:start position:0% +system actually satisfy this symmetry +and also the consequence is that from + + align:start position:0% +and also the consequence is that from + + + align:start position:0% +and also the consequence is that from +there you can clue that if you have so + + align:start position:0% +there you can clue that if you have so + + + align:start position:0% +there you can clue that if you have so +will have a set of eigen vectors from M + + align:start position:0% +will have a set of eigen vectors from M + + + align:start position:0% +will have a set of eigen vectors from M +s 1 K matrix eigen value problem and + + align:start position:0% +s 1 K matrix eigen value problem and + + + align:start position:0% +s 1 K matrix eigen value problem and +that is going to be also the eigenvector + + align:start position:0% +that is going to be also the eigenvector + + + align:start position:0% +that is going to be also the eigenvector +of s okay any questions okay so M minus + + align:start position:0% +of s okay any questions okay so M minus + + + align:start position:0% +of s okay any questions okay so M minus +1 K eigen vectors ah also s I come back + + align:start position:0% + + + + align:start position:0% + +okay that's actually what we have + + align:start position:0% +okay that's actually what we have + + + align:start position:0% +okay that's actually what we have +learned from this small exercise now you + + align:start position:0% +learned from this small exercise now you + + + align:start position:0% +learned from this small exercise now you +can say wait wait this is actually now + + align:start position:0% +can say wait wait this is actually now + + + align:start position:0% +can say wait wait this is actually now +we would need right + + align:start position:0% +we would need right + + + align:start position:0% +we would need right +I would like we would like to argue that + + align:start position:0% +I would like we would like to argue that + + + align:start position:0% +I would like we would like to argue that +s matrix I can stop s matrix eigenvalue + + align:start position:0% +s matrix I can stop s matrix eigenvalue + + + align:start position:0% +s matrix I can stop s matrix eigenvalue +problem then I can learn about a + + align:start position:0% +problem then I can learn about a + + + align:start position:0% +problem then I can learn about a +solution of n minus 1 K matrix by this + + align:start position:0% +solution of n minus 1 K matrix by this + + + align:start position:0% +solution of n minus 1 K matrix by this +logic essentially in the opposite + + align:start position:0% +logic essentially in the opposite + + + align:start position:0% +logic essentially in the opposite +direction right you said okay you solve + + align:start position:0% +direction right you said okay you solve + + + align:start position:0% +direction right you said okay you solve +things already then actually is also s + + align:start position:0% +things already then actually is also s + + + align:start position:0% +things already then actually is also s +matrix eigenvalue problem so now what + + align:start position:0% +matrix eigenvalue problem so now what + + + align:start position:0% +matrix eigenvalue problem so now what +I'm going to do is to reverse the logic + + align:start position:0% +I'm going to do is to reverse the logic + + + align:start position:0% +I'm going to do is to reverse the logic +and see if it works okay again to see + + align:start position:0% +and see if it works okay again to see + + + align:start position:0% +and see if it works okay again to see +what will happen + + align:start position:0% +what will happen + + + align:start position:0% +what will happen +okay so now I would like to prove that + + align:start position:0% +okay so now I would like to prove that + + + align:start position:0% +okay so now I would like to prove that +if I saw s matrix eigenvalue problem + + align:start position:0% +if I saw s matrix eigenvalue problem + + + align:start position:0% +if I saw s matrix eigenvalue problem +i have also solved the eigenvectors for + + align:start position:0% +i have also solved the eigenvectors for + + + align:start position:0% +i have also solved the eigenvectors for +msy Hemet run the logic in the opposite + + align:start position:0% +msy Hemet run the logic in the opposite + + + align:start position:0% +msy Hemet run the logic in the opposite +direction okay so if i really v'n two + + align:start position:0% +direction okay so if i really v'n two + + + align:start position:0% +direction okay so if i really v'n two +things one s a is equal to beta a number + + align:start position:0% +things one s a is equal to beta a number + + + align:start position:0% +things one s a is equal to beta a number +two s matrix and the M minus 1 K matrix + + align:start position:0% +two s matrix and the M minus 1 K matrix + + + align:start position:0% +two s matrix and the M minus 1 K matrix +commute okay if those are like even + + align:start position:0% +commute okay if those are like even + + + align:start position:0% +commute okay if those are like even +conditions okay then I can as we + + align:start position:0% +conditions okay then I can as we + + + align:start position:0% +conditions okay then I can as we +conclude that s M minus 1 K hey okay I + + align:start position:0% +conclude that s M minus 1 K hey okay I + + + align:start position:0% +conclude that s M minus 1 K hey okay I +can as you construct this expression I + + align:start position:0% +can as you construct this expression I + + + align:start position:0% +can as you construct this expression I +write down s n minus 1 K a ok because + + align:start position:0% +write down s n minus 1 K a ok because + + + align:start position:0% +write down s n minus 1 K a ok because +they commute right they can expect in a + + align:start position:0% +they commute right they can expect in a + + + align:start position:0% +they commute right they can expect in a +to swap em s 1 K and as safely without + + align:start position:0% +to swap em s 1 K and as safely without + + + align:start position:0% +to swap em s 1 K and as safely without +actually introducing any more turns and + + align:start position:0% +actually introducing any more turns and + + + align:start position:0% +actually introducing any more turns and +this will be equal to n minus 1 K s a ok + + align:start position:0% +this will be equal to n minus 1 K s a ok + + + align:start position:0% +this will be equal to n minus 1 K s a ok +and s a from the first expression as n + + align:start position:0% +and s a from the first expression as n + + + align:start position:0% +and s a from the first expression as n +is equal to Beta Beta is a number okay + + align:start position:0% +is equal to Beta Beta is a number okay + + + align:start position:0% +is equal to Beta Beta is a number okay +therefore this expression will become + + align:start position:0% +therefore this expression will become + + + align:start position:0% +therefore this expression will become +beta n minus 1 K a so beta can penetrate + + align:start position:0% +beta n minus 1 K a so beta can penetrate + + + align:start position:0% +beta n minus 1 K a so beta can penetrate +su matrix because beta is just a number + + align:start position:0% +su matrix because beta is just a number + + + align:start position:0% +su matrix because beta is just a number +is the eigenvalue it's an eigenvalue or + + align:start position:0% +is the eigenvalue it's an eigenvalue or + + + align:start position:0% +is the eigenvalue it's an eigenvalue or +s matrix okay so what does this mean + + align:start position:0% + + + + align:start position:0% + +okay so so so what does it mean + + align:start position:0% +okay so so so what does it mean + + + align:start position:0% +okay so so so what does it mean +so this means that if you look at this + + align:start position:0% +so this means that if you look at this + + + align:start position:0% +so this means that if you look at this +this part and that part you look at the + + align:start position:0% +this part and that part you look at the + + + align:start position:0% +this part and that part you look at the +beginning and at the end of the + + align:start position:0% +beginning and at the end of the + + + align:start position:0% +beginning and at the end of the +expression you immediately conclude that + + align:start position:0% +expression you immediately conclude that + + + align:start position:0% +expression you immediately conclude that +n minus 1 K a ok this expression is also + + align:start position:0% +n minus 1 K a ok this expression is also + + + align:start position:0% +n minus 1 K a ok this expression is also +an eigenvector of s matrix right so you + + align:start position:0% +an eigenvector of s matrix right so you + + + align:start position:0% +an eigenvector of s matrix right so you +have s matrix acting n minus 1 T a and + + align:start position:0% +have s matrix acting n minus 1 T a and + + + align:start position:0% +have s matrix acting n minus 1 T a and +that will give you something + + align:start position:0% +that will give you something + + + align:start position:0% +that will give you something +proportional to n minus 1 K a you see + + align:start position:0% +proportional to n minus 1 K a you see + + + align:start position:0% +proportional to n minus 1 K a you see +it's a metric right it's actually not + + align:start position:0% +it's a metric right it's actually not + + + align:start position:0% +it's a metric right it's actually not +magic but it says she's just you know + + align:start position:0% +magic but it says she's just you know + + + align:start position:0% +magic but it says she's just you know +already a logical extension right okay + + align:start position:0% +already a logical extension right okay + + + align:start position:0% +already a logical extension right okay +well cool so that means this is also an + + align:start position:0% +well cool so that means this is also an + + + align:start position:0% +well cool so that means this is also an +eigenvector OS right and also another + + align:start position:0% +eigenvector OS right and also another + + + align:start position:0% +eigenvector OS right and also another +thing which is interesting is that they + + align:start position:0% +thing which is interesting is that they + + + align:start position:0% +thing which is interesting is that they +share the same I come back I can value + + align:start position:0% +share the same I come back I can value + + + align:start position:0% +share the same I come back I can value +beta right listen I can value right okay + + align:start position:0% +beta right listen I can value right okay + + + align:start position:0% +beta right listen I can value right okay +so if I can values of s so you can get + + align:start position:0% +so if I can values of s so you can get + + + align:start position:0% +so if I can values of s so you can get +several I can value right in this case + + align:start position:0% +several I can value right in this case + + + align:start position:0% +several I can value right in this case +two by two matrix you will get how many + + align:start position:0% +two by two matrix you will get how many + + + align:start position:0% +two by two matrix you will get how many +to write to eigen values if those two + + align:start position:0% +to write to eigen values if those two + + + align:start position:0% +to write to eigen values if those two +eigen values are different then I can + + align:start position:0% +eigen values are different then I can + + + align:start position:0% +eigen values are different then I can +conclude that n minus 1 K a okay must be + + align:start position:0% +conclude that n minus 1 K a okay must be + + + align:start position:0% +conclude that n minus 1 K a okay must be +proportional to a right because though + + align:start position:0% +proportional to a right because though + + + align:start position:0% +proportional to a right because though +because this is actually the same eigen + + align:start position:0% +because this is actually the same eigen + + + align:start position:0% +because this is actually the same eigen +value problem and listen I can well do + + align:start position:0% +value problem and listen I can well do + + + align:start position:0% +value problem and listen I can well do +beta since all the eigen values from the + + align:start position:0% +beta since all the eigen values from the + + + align:start position:0% +beta since all the eigen values from the +solution of eigen value problem of as a + + align:start position:0% +solution of eigen value problem of as a + + + align:start position:0% +solution of eigen value problem of as a +equal to beta a those eigen values are + + align:start position:0% +equal to beta a those eigen values are + + + align:start position:0% +equal to beta a those eigen values are +all different therefore I can argue that + + align:start position:0% +all different therefore I can argue that + + + align:start position:0% +all different therefore I can argue that +n minus 1 ka is proportional to a ok + + align:start position:0% +n minus 1 ka is proportional to a ok + + + align:start position:0% +n minus 1 ka is proportional to a ok +therefore M minus 1 K a is equal to + + align:start position:0% +therefore M minus 1 K a is equal to + + + align:start position:0% +therefore M minus 1 K a is equal to +Omega square Omega square is actually + + align:start position:0% +Omega square Omega square is actually + + + align:start position:0% +Omega square Omega square is actually +some constant ok this is really amazing + + align:start position:0% +some constant ok this is really amazing + + + align:start position:0% +some constant ok this is really amazing +because that means even the two + + align:start position:0% +because that means even the two + + + align:start position:0% +because that means even the two +condition the first one I can figure out + + align:start position:0% +condition the first one I can figure out + + + align:start position:0% +condition the first one I can figure out +that I can value and eigen vectors of s + + align:start position:0% +that I can value and eigen vectors of s + + + align:start position:0% +that I can value and eigen vectors of s +matrix second if s matrix and then n + + align:start position:0% +matrix second if s matrix and then n + + + align:start position:0% +matrix second if s matrix and then n +minus 1 K matrix interaction matrix they + + align:start position:0% +minus 1 K matrix interaction matrix they + + + align:start position:0% +minus 1 K matrix interaction matrix they +commute then I can actually already + + align:start position:0% +commute then I can actually already + + + align:start position:0% +commute then I can actually already +figure out what are the eigen vectors of + + align:start position:0% +figure out what are the eigen vectors of + + + align:start position:0% +figure out what are the eigen vectors of +n minus 1 K matrix ok and another thing + + align:start position:0% +n minus 1 K matrix ok and another thing + + + align:start position:0% +n minus 1 K matrix ok and another thing +which we learn from here is that wow + + align:start position:0% +which we learn from here is that wow + + + align:start position:0% +which we learn from here is that wow +that's good because the eigenvectors are + + align:start position:0% +that's good because the eigenvectors are + + + align:start position:0% +that's good because the eigenvectors are +already saw therefore i just have to + + align:start position:0% +already saw therefore i just have to + + + align:start position:0% +already saw therefore i just have to +calculate this i just it's just a normal + + align:start position:0% +calculate this i just it's just a normal + + + align:start position:0% +calculate this i just it's just a normal +operation it's not the eigenvalue + + align:start position:0% +operation it's not the eigenvalue + + + align:start position:0% +operation it's not the eigenvalue +problem anymore i just multiply MS 1 k + + align:start position:0% +problem anymore i just multiply MS 1 k + + + align:start position:0% +problem anymore i just multiply MS 1 k +times a then i can actually get the + + align:start position:0% +times a then i can actually get the + + + align:start position:0% +times a then i can actually get the +value Omega square you see that's + + align:start position:0% +value Omega square you see that's + + + align:start position:0% +value Omega square you see that's +actually much easier than solving like + + align:start position:0% +actually much easier than solving like + + + align:start position:0% +actually much easier than solving like +um where the problem of M minus 1 K + + align:start position:0% +um where the problem of M minus 1 K + + + align:start position:0% +um where the problem of M minus 1 K +matrix ok that says very good news + + align:start position:0% +matrix ok that says very good news + + + align:start position:0% +matrix ok that says very good news +finally I think the most important + + align:start position:0% +finally I think the most important + + + align:start position:0% +finally I think the most important +consequence is that sorry for this the + + align:start position:0% +consequence is that sorry for this the + + + align:start position:0% +consequence is that sorry for this the +most important consequence is that once + + align:start position:0% +most important consequence is that once + + + align:start position:0% +most important consequence is that once +we solve this system which satisfy the + + align:start position:0% +we solve this system which satisfy the + + + align:start position:0% +we solve this system which satisfy the +symmetry described by this s matrix we + + align:start position:0% +symmetry described by this s matrix we + + + align:start position:0% +symmetry described by this s matrix we +have solved all the possible systems + + align:start position:0% +have solved all the possible systems + + + align:start position:0% +have solved all the possible systems +which satisfy the same symmetry for + + align:start position:0% +which satisfy the same symmetry for + + + align:start position:0% +which satisfy the same symmetry for +example in this case I solve a type of + + align:start position:0% +example in this case I solve a type of + + + align:start position:0% +example in this case I solve a type of +pendulum problem ok they look symmetric + + align:start position:0% +pendulum problem ok they look symmetric + + + align:start position:0% +pendulum problem ok they look symmetric +right and I can of course I can draw + + align:start position:0% +right and I can of course I can draw + + + align:start position:0% +right and I can of course I can draw +another one which is like this + + align:start position:0% +another one which is like this + + + align:start position:0% +another one which is like this +it's my circular and there are two wars + + align:start position:0% +it's my circular and there are two wars + + + align:start position:0% +it's my circular and there are two wars +which essentially there are three + + align:start position:0% +which essentially there are three + + + align:start position:0% +which essentially there are three +Springs connected to the wall this + + align:start position:0% +Springs connected to the wall this + + + align:start position:0% +Springs connected to the wall this +problem is already also solved right + + align:start position:0% +problem is already also solved right + + + align:start position:0% +problem is already also solved right +because it also satisfies the same + + align:start position:0% +because it also satisfies the same + + + align:start position:0% +because it also satisfies the same +symmetry and of course I can add more + + align:start position:0% +symmetry and of course I can add more + + + align:start position:0% +symmetry and of course I can add more +like like this called crazy more this is + + align:start position:0% +like like this called crazy more this is + + + align:start position:0% +like like this called crazy more this is +also solved right because this is also + + align:start position:0% +also solved right because this is also + + + align:start position:0% +also solved right because this is also +symmetric right I can add more okay + + align:start position:0% +symmetric right I can add more okay + + + align:start position:0% +symmetric right I can add more okay +right that is right it's also symmetric + + align:start position:0% +right that is right it's also symmetric + + + align:start position:0% +right that is right it's also symmetric +right and this let's see the eigenvector + + align:start position:0% +right and this let's see the eigenvector + + + align:start position:0% +right and this let's see the eigenvector +of this n minus 1 k matrix eigenvalue + + align:start position:0% +of this n minus 1 k matrix eigenvalue + + + align:start position:0% +of this n minus 1 k matrix eigenvalue +problem will be identical to what we + + align:start position:0% +problem will be identical to what we + + + align:start position:0% +problem will be identical to what we +have already saw here okay so that + + align:start position:0% +have already saw here okay so that + + + align:start position:0% +have already saw here okay so that +essentially is really amazing if you + + align:start position:0% +essentially is really amazing if you + + + align:start position:0% +essentially is really amazing if you +speak the right language and the cut + + align:start position:0% +speak the right language and the cut + + + align:start position:0% +speak the right language and the cut +into the pattern in the right angle you + + align:start position:0% +into the pattern in the right angle you + + + align:start position:0% +into the pattern in the right angle you +actually found out AG you can solve a + + align:start position:0% +actually found out AG you can solve a + + + align:start position:0% +actually found out AG you can solve a +multiple problem at one time okay any + + align:start position:0% +multiple problem at one time okay any + + + align:start position:0% +multiple problem at one time okay any +questions okay + + align:start position:0% +questions okay + + + align:start position:0% +questions okay +so so that is actually very nice and + + align:start position:0% +so so that is actually very nice and + + + align:start position:0% +so so that is actually very nice and +this is actually a very important + + align:start position:0% +this is actually a very important + + + align:start position:0% +this is actually a very important +preparation to the the next step + + align:start position:0% +preparation to the the next step + + + align:start position:0% +preparation to the the next step +actually so now we have understood + + align:start position:0% +actually so now we have understood + + + align:start position:0% +actually so now we have understood +coupled oscillator and we have learned a + + align:start position:0% +coupled oscillator and we have learned a + + + align:start position:0% +coupled oscillator and we have learned a +little bit about symmetry right + + align:start position:0% +little bit about symmetry right + + + align:start position:0% +little bit about symmetry right +therefore I would like to go to Infini + + align:start position:0% +therefore I would like to go to Infini + + + align:start position:0% +therefore I would like to go to Infini +number of coupled oscillators okay + + align:start position:0% +number of coupled oscillators okay + + + align:start position:0% +number of coupled oscillators okay +so that is actually the next step which + + align:start position:0% +so that is actually the next step which + + + align:start position:0% +so that is actually the next step which +we are going to move on in the three so + + align:start position:0% +we are going to move on in the three so + + + align:start position:0% +we are going to move on in the three so +this is actually why example infinite + + align:start position:0% +this is actually why example infinite + + + align:start position:0% +this is actually why example infinite +system okay + + align:start position:0% +system okay + + + align:start position:0% +system okay +and I cannot write the whole universe + + align:start position:0% +and I cannot write the whole universe + + + align:start position:0% +and I cannot write the whole universe +right because it is infinite so I + + align:start position:0% +right because it is infinite so I + + + align:start position:0% +right because it is infinite so I +couldn't include everything in the in + + align:start position:0% +couldn't include everything in the in + + + align:start position:0% +couldn't include everything in the in +the slide but this is your example + + align:start position:0% +the slide but this is your example + + + align:start position:0% +the slide but this is your example +system okay looks hopeful is right in + + align:start position:0% +system okay looks hopeful is right in + + + align:start position:0% +system okay looks hopeful is right in +general we don't know how to solve + + align:start position:0% +general we don't know how to solve + + + align:start position:0% +general we don't know how to solve +infinite system because if you have + + align:start position:0% +infinite system because if you have + + + align:start position:0% +infinite system because if you have +symphony number of things they are + + align:start position:0% +symphony number of things they are + + + align:start position:0% +symphony number of things they are +connected to each other in random ways + + align:start position:0% +connected to each other in random ways + + + align:start position:0% +connected to each other in random ways +then the see the problem become really + + align:start position:0% +then the see the problem become really + + + align:start position:0% +then the see the problem become really +pree Katie okay in general I don't know + + align:start position:0% +pree Katie okay in general I don't know + + + align:start position:0% +pree Katie okay in general I don't know +how to solve this problem + + align:start position:0% +how to solve this problem + + + align:start position:0% +how to solve this problem +okay and if you are at a Bui major the + + align:start position:0% +okay and if you are at a Bui major the + + + align:start position:0% +okay and if you are at a Bui major the +first thing maybe you would like to do + + align:start position:0% +first thing maybe you would like to do + + + align:start position:0% +first thing maybe you would like to do +is now I have this picture and I can put + + align:start position:0% +is now I have this picture and I can put + + + align:start position:0% +is now I have this picture and I can put +everything in my computer and see how + + align:start position:0% +everything in my computer and see how + + + align:start position:0% +everything in my computer and see how +things evolve as a function of time + + align:start position:0% +things evolve as a function of time + + + align:start position:0% +things evolve as a function of time +right of course we can rely on the + + align:start position:0% +right of course we can rely on the + + + align:start position:0% +right of course we can rely on the +computers and see what we can learn from + + align:start position:0% +computers and see what we can learn from + + + align:start position:0% +computers and see what we can learn from +it and if you met you are a major of + + align:start position:0% +it and if you met you are a major of + + + align:start position:0% +it and if you met you are a major of +mathematics you say no this is not the + + align:start position:0% +mathematics you say no this is not the + + + align:start position:0% +mathematics you say no this is not the +problem I am going to work on okay I + + align:start position:0% +problem I am going to work on okay I + + + align:start position:0% +problem I am going to work on okay I +don't care but as a physicist what we + + align:start position:0% +don't care but as a physicist what we + + + align:start position:0% +don't care but as a physicist what we +are going to do is that how we look at + + align:start position:0% +are going to do is that how we look at + + + align:start position:0% +are going to do is that how we look at +these infinities then okay interesting + + align:start position:0% +these infinities then okay interesting + + + align:start position:0% +these infinities then okay interesting +right + + align:start position:0% +right + + + align:start position:0% +right +there's a lot of things a lot of small + + align:start position:0% +there's a lot of things a lot of small + + + align:start position:0% +there's a lot of things a lot of small +balls connected to big balls right super + + align:start position:0% +balls connected to big balls right super + + + align:start position:0% +balls connected to big balls right super +big one and protein since in log scale + + align:start position:0% +big one and protein since in log scale + + + align:start position:0% +big one and protein since in log scale +so those poles are really really large + + align:start position:0% +so those poles are really really large + + + align:start position:0% +so those poles are really really large +compared to the all the other ports + + align:start position:0% +compared to the all the other ports + + + align:start position:0% +compared to the all the other ports +connected to this system therefore as a + + align:start position:0% +connected to this system therefore as a + + + align:start position:0% +connected to this system therefore as a +physicist I'm going to ignore all the + + align:start position:0% +physicist I'm going to ignore all the + + + align:start position:0% +physicist I'm going to ignore all the +other boys oh if I do that then it began + + align:start position:0% +other boys oh if I do that then it began + + + align:start position:0% +other boys oh if I do that then it began +this is some kind of symmetry you can + + align:start position:0% +this is some kind of symmetry you can + + + align:start position:0% +this is some kind of symmetry you can +let you see from here right what I did I + + align:start position:0% +let you see from here right what I did I + + + align:start position:0% +let you see from here right what I did I +see the symmetry you see there are three + + align:start position:0% +see the symmetry you see there are three + + + align:start position:0% +see the symmetry you see there are three +poles + + align:start position:0% +poles + + + align:start position:0% +poles +they're connected to each other they are + + align:start position:0% +they're connected to each other they are + + + align:start position:0% +they're connected to each other they are +equally spaced we have a translation + + align:start position:0% +equally spaced we have a translation + + + align:start position:0% +equally spaced we have a translation +symmetry you see so you can see that + + align:start position:0% +symmetry you see so you can see that + + + align:start position:0% +symmetry you see so you can see that +actually that's actually how we actually + + align:start position:0% +actually that's actually how we actually + + + align:start position:0% +actually that's actually how we actually +think about a problem of course + + align:start position:0% +think about a problem of course + + + align:start position:0% +think about a problem of course +different few have different kind of + + align:start position:0% +different few have different kind of + + + align:start position:0% +different few have different kind of +thinking and a different kind of problem + + align:start position:0% +thinking and a different kind of problem + + + align:start position:0% +thinking and a different kind of problem +they would like to focus on but as a + + align:start position:0% +they would like to focus on but as a + + + align:start position:0% +they would like to focus on but as a +position I would like to know how this + + align:start position:0% +position I would like to know how this + + + align:start position:0% +position I would like to know how this +system will work and that is actually + + align:start position:0% +system will work and that is actually + + + align:start position:0% +system will work and that is actually +what I'm going to do okay so that's very + + align:start position:0% +what I'm going to do okay so that's very + + + align:start position:0% +what I'm going to do okay so that's very +nice we are going to discuss infinite + + align:start position:0% +nice we are going to discuss infinite + + + align:start position:0% +nice we are going to discuss infinite +system so what is actually the infinite + + align:start position:0% +system so what is actually the infinite + + + align:start position:0% +system so what is actually the infinite +system I am going to talk about + + align:start position:0% +system I am going to talk about + + + align:start position:0% +system I am going to talk about +essentially there's infinite system with + + align:start position:0% +essentially there's infinite system with + + + align:start position:0% +essentially there's infinite system with +space translation symmetry + + align:start position:0% +space translation symmetry + + + align:start position:0% +space translation symmetry +so to save some time I have already + + align:start position:0% +so to save some time I have already + + + align:start position:0% +so to save some time I have already +written right I have already written + + align:start position:0% +written right I have already written + + + align:start position:0% +written right I have already written +founded the matrix involving this system + + align:start position:0% +founded the matrix involving this system + + + align:start position:0% +founded the matrix involving this system +here + + align:start position:0% +here + + + align:start position:0% +here +what I'm interested is mass-spring + + align:start position:0% +what I'm interested is mass-spring + + + align:start position:0% +what I'm interested is mass-spring +system okay infinite number of mass and + + align:start position:0% +system okay infinite number of mass and + + + align:start position:0% +system okay infinite number of mass and +spring and they actually satisfy space + + align:start position:0% +spring and they actually satisfy space + + + align:start position:0% +spring and they actually satisfy space +translation symmetry okay they are + + align:start position:0% +translation symmetry okay they are + + + align:start position:0% +translation symmetry okay they are +connected to each other by Springs with + + align:start position:0% +connected to each other by Springs with + + + align:start position:0% +connected to each other by Springs with +natural ends a and spring constant K + + align:start position:0% +natural ends a and spring constant K + + + align:start position:0% +natural ends a and spring constant K +okay and there are infinite number of + + align:start position:0% +okay and there are infinite number of + + + align:start position:0% +okay and there are infinite number of +them actually line up from the left-hand + + align:start position:0% +them actually line up from the left-hand + + + align:start position:0% +them actually line up from the left-hand +side of the edge of the universe to the + + align:start position:0% +side of the edge of the universe to the + + + align:start position:0% +side of the edge of the universe to the +right-hand side edge of the universe + + align:start position:0% +right-hand side edge of the universe + + + align:start position:0% +right-hand side edge of the universe +okay I prepared this system ok took me a + + align:start position:0% +okay I prepared this system ok took me a + + + align:start position:0% +okay I prepared this system ok took me a +long time okay all right it's very + + align:start position:0% +long time okay all right it's very + + + align:start position:0% +long time okay all right it's very +difficult to describe this kind of + + align:start position:0% +difficult to describe this kind of + + + align:start position:0% +difficult to describe this kind of +system right so the first thing we have + + align:start position:0% +system right so the first thing we have + + + align:start position:0% +system right so the first thing we have +done from ao3 is that in order to + + align:start position:0% +done from ao3 is that in order to + + + align:start position:0% +done from ao3 is that in order to +describe this system I need to define a + + align:start position:0% +describe this system I need to define a + + + align:start position:0% +describe this system I need to define a +coordinate system right and also help + + align:start position:0% +coordinate system right and also help + + + align:start position:0% +coordinate system right and also help +everything properly labeled so I + + align:start position:0% +everything properly labeled so I + + + align:start position:0% +everything properly labeled so I +introduce a label say minus 1 j j plus 1 + + align:start position:0% +introduce a label say minus 1 j j plus 1 + + + align:start position:0% +introduce a label say minus 1 j j plus 1 +j plus 2 just to name each little math I + + align:start position:0% +j plus 2 just to name each little math I + + + align:start position:0% +j plus 2 just to name each little math I +am talking about okay no other purpose + + align:start position:0% +am talking about okay no other purpose + + + align:start position:0% +am talking about okay no other purpose +then once I have the label I can + + align:start position:0% +then once I have the label I can + + + align:start position:0% +then once I have the label I can +actually write everything Express the + + align:start position:0% +actually write everything Express the + + + align:start position:0% +actually write everything Express the +displacement or total mass as XT minus 1 + + align:start position:0% +displacement or total mass as XT minus 1 + + + align:start position:0% +displacement or total mass as XT minus 1 +X a X a + 1 XA plus 2 that's just a + + align:start position:0% +X a X a + 1 XA plus 2 that's just a + + + align:start position:0% +X a X a + 1 XA plus 2 that's just a +displacement from the equilibrium + + align:start position:0% +displacement from the equilibrium + + + align:start position:0% +displacement from the equilibrium +position of the mass okay and this + + align:start position:0% +position of the mass okay and this + + + align:start position:0% +position of the mass okay and this +system will have an equation of motion + + align:start position:0% +system will have an equation of motion + + + align:start position:0% +system will have an equation of motion +looks like this so if now I focus the + + align:start position:0% +looks like this so if now I focus the + + + align:start position:0% +looks like this so if now I focus the +detailed mass check ok then I can I + + align:start position:0% +detailed mass check ok then I can I + + + align:start position:0% +detailed mass check ok then I can I +should write down the equation of motion + + align:start position:0% +should write down the equation of motion + + + align:start position:0% +should write down the equation of motion +there are two Springs there are there + + align:start position:0% +there are two Springs there are there + + + align:start position:0% +there are two Springs there are there +are two Springs connected to this mass + + align:start position:0% +are two Springs connected to this mass + + + align:start position:0% +are two Springs connected to this mass +right + + align:start position:0% +right + + + align:start position:0% +right +therefore you are + + align:start position:0% +therefore you are + + + align:start position:0% +therefore you are +to have tools spring force right since + + align:start position:0% +to have tools spring force right since + + + align:start position:0% +to have tools spring force right since +this is usually idealized the Springs + + align:start position:0% +this is usually idealized the Springs + + + align:start position:0% +this is usually idealized the Springs +with spring constant capital K therefore + + align:start position:0% +with spring constant capital K therefore + + + align:start position:0% +with spring constant capital K therefore +I can write down immediately the + + align:start position:0% +I can write down immediately the + + + align:start position:0% +I can write down immediately the +equation of motion is actually equal to + + align:start position:0% +equation of motion is actually equal to + + + align:start position:0% +equation of motion is actually equal to +MX double dot J is equal to minus k XA + + align:start position:0% +MX double dot J is equal to minus k XA + + + align:start position:0% +MX double dot J is equal to minus k XA +minus XA minus 1 minus this disaster + + align:start position:0% +minus XA minus 1 minus this disaster + + + align:start position:0% +minus XA minus 1 minus this disaster +that the right hand side spring force + + align:start position:0% +that the right hand side spring force + + + align:start position:0% +that the right hand side spring force +minus k xj minus XA plus 1 we have done + + align:start position:0% +minus k xj minus XA plus 1 we have done + + + align:start position:0% +minus k xj minus XA plus 1 we have done +this exercise before I with a simpler + + align:start position:0% +this exercise before I with a simpler + + + align:start position:0% +this exercise before I with a simpler +problem ok as you Joe I can collect all + + align:start position:0% +problem ok as you Joe I can collect all + + + align:start position:0% +problem ok as you Joe I can collect all +the terms associated with XA minus 1 XA + + align:start position:0% +the terms associated with XA minus 1 XA + + + align:start position:0% +the terms associated with XA minus 1 XA +and the XA plus 1 together then I get + + align:start position:0% +and the XA plus 1 together then I get + + + align:start position:0% +and the XA plus 1 together then I get +this expression which is really looks + + align:start position:0% +this expression which is really looks + + + align:start position:0% +this expression which is really looks +nice + + align:start position:0% +nice + + + align:start position:0% +nice +okay and I assume that this system is + + align:start position:0% +okay and I assume that this system is + + + align:start position:0% +okay and I assume that this system is +actually undergoing some kind of + + align:start position:0% +actually undergoing some kind of + + + align:start position:0% +actually undergoing some kind of +oscillation okay therefore I assume that + + align:start position:0% +oscillation okay therefore I assume that + + + align:start position:0% +oscillation okay therefore I assume that +this is a solution X J will be equal to + + align:start position:0% +this is a solution X J will be equal to + + + align:start position:0% +this is a solution X J will be equal to +AJ is the amplitude of J's mass okay + + align:start position:0% +AJ is the amplitude of J's mass okay + + + align:start position:0% +AJ is the amplitude of J's mass okay +cosine Omega T plus Phi Omega is a + + align:start position:0% +cosine Omega T plus Phi Omega is a + + + align:start position:0% +cosine Omega T plus Phi Omega is a +should the oscillation frequency and + + align:start position:0% +should the oscillation frequency and + + + align:start position:0% +should the oscillation frequency and +finally the face and I don't know what + + align:start position:0% +finally the face and I don't know what + + + align:start position:0% +finally the face and I don't know what +is actually Omega and AJ yet okay we + + align:start position:0% +is actually Omega and AJ yet okay we + + + align:start position:0% +is actually Omega and AJ yet okay we +would like to figure that out and let's + + align:start position:0% +would like to figure that out and let's + + + align:start position:0% +would like to figure that out and let's +do job okay you can issued it right down + + align:start position:0% +do job okay you can issued it right down + + + align:start position:0% +do job okay you can issued it right down +the n matrix okay and matrix is actually + + align:start position:0% +the n matrix okay and matrix is actually + + + align:start position:0% +the n matrix okay and matrix is actually +really simple + + align:start position:0% +really simple + + + align:start position:0% +really simple +in the diagonal turns ago no turns out o + + align:start position:0% +in the diagonal turns ago no turns out o + + + align:start position:0% +in the diagonal turns ago no turns out o +N and the off diagonal terms are all 0 + + align:start position:0% +N and the off diagonal terms are all 0 + + + align:start position:0% +N and the off diagonal terms are all 0 +right and you don't really need to copy + + align:start position:0% +right and you don't really need to copy + + + align:start position:0% +right and you don't really need to copy +them because we are organizing the + + align:start position:0% +them because we are organizing the + + + align:start position:0% +them because we are organizing the +lecture note n minus 1 K matrix hi I + + align:start position:0% +lecture note n minus 1 K matrix hi I + + + align:start position:0% +lecture note n minus 1 K matrix hi I +have already arranged my turns here + + align:start position:0% +have already arranged my turns here + + + align:start position:0% +have already arranged my turns here +therefore it looks like this you have a + + align:start position:0% +therefore it looks like this you have a + + + align:start position:0% +therefore it looks like this you have a +strange structure you have three turns + + align:start position:0% +strange structure you have three turns + + + align:start position:0% +strange structure you have three turns +kind of in the diagonal turns and this + + align:start position:0% +kind of in the diagonal turns and this + + + align:start position:0% +kind of in the diagonal turns and this +issue is shifting as a function of + + align:start position:0% +issue is shifting as a function of + + + align:start position:0% +issue is shifting as a function of +number of rows and the OD other part of + + align:start position:0% +number of rows and the OD other part of + + + align:start position:0% +number of rows and the OD other part of +the metrics actually zero okay it's an + + align:start position:0% +the metrics actually zero okay it's an + + + align:start position:0% +the metrics actually zero okay it's an +infinite as Infini dimension matrix + + align:start position:0% +infinite as Infini dimension matrix + + + align:start position:0% +infinite as Infini dimension matrix +finally I would like to also write my a + + align:start position:0% +finally I would like to also write my a + + + align:start position:0% +finally I would like to also write my a +matrix is the vector of M produced right + + align:start position:0% +matrix is the vector of M produced right + + + align:start position:0% +matrix is the vector of M produced right +so you have many many numbers AJ AJ plus + + align:start position:0% +so you have many many numbers AJ AJ plus + + + align:start position:0% +so you have many many numbers AJ AJ plus +one eight eight plus two okay etcetera + + align:start position:0% +one eight eight plus two okay etcetera + + + align:start position:0% +one eight eight plus two okay etcetera +etcetera okay now very easy right + + align:start position:0% +etcetera okay now very easy right + + + align:start position:0% +etcetera okay now very easy right +the question is actually can be solved + + align:start position:0% +the question is actually can be solved + + + align:start position:0% +the question is actually can be solved +right + + align:start position:0% +right + + + align:start position:0% +right +you just have to solve the n minus 1 K + + align:start position:0% +you just have to solve the n minus 1 K + + + align:start position:0% +you just have to solve the n minus 1 K +matrix right that's easy right it is an + + align:start position:0% +matrix right that's easy right it is an + + + align:start position:0% +matrix right that's easy right it is an +infinite number times infinite number of + + align:start position:0% +infinite number times infinite number of + + + align:start position:0% +infinite number times infinite number of +metrics right super easy no actually not + + align:start position:0% +metrics right super easy no actually not + + + align:start position:0% +metrics right super easy no actually not +right so we are in trouble I don't know + + align:start position:0% +right so we are in trouble I don't know + + + align:start position:0% +right so we are in trouble I don't know +how to solve this problem okay what can + + align:start position:0% +how to solve this problem okay what can + + + align:start position:0% +how to solve this problem okay what can +we do anybody have any suggestion to me + + align:start position:0% + + + + align:start position:0% + +yeah math department is coming in to + + align:start position:0% +yeah math department is coming in to + + + align:start position:0% +yeah math department is coming in to +help yes but they're actually people + + align:start position:0% +help yes but they're actually people + + + align:start position:0% +help yes but they're actually people +asking that we learn some concept which + + align:start position:0% +asking that we learn some concept which + + + align:start position:0% +asking that we learn some concept which +we just learned like there's a what what + + align:start position:0% +we just learned like there's a what what + + + align:start position:0% +we just learned like there's a what what +kind of property of this sister symmetry + + align:start position:0% +kind of property of this sister symmetry + + + align:start position:0% +kind of property of this sister symmetry +all right + + align:start position:0% +all right + + + align:start position:0% +all right +we have symmetry okay so this n minus 1 + + align:start position:0% +we have symmetry okay so this n minus 1 + + + align:start position:0% +we have symmetry okay so this n minus 1 +K matrix looks horrible right but if I'd + + align:start position:0% +K matrix looks horrible right but if I'd + + + align:start position:0% +K matrix looks horrible right but if I'd +write down the symmetric matrix actually + + align:start position:0% +write down the symmetric matrix actually + + + align:start position:0% +write down the symmetric matrix actually +it looks slightly better okay so what is + + align:start position:0% +it looks slightly better okay so what is + + + align:start position:0% +it looks slightly better okay so what is +actually the symmetry matrix okay so one + + align:start position:0% +actually the symmetry matrix okay so one + + + align:start position:0% +actually the symmetry matrix okay so one +observation we can make from this system + + align:start position:0% +observation we can make from this system + + + align:start position:0% +observation we can make from this system +is that if I shipped this system a to + + align:start position:0% +is that if I shipped this system a to + + + align:start position:0% +is that if I shipped this system a to +the left okay I shipped this these two + + align:start position:0% +the left okay I shipped this these two + + + align:start position:0% +the left okay I shipped this these two +masts to laughing I should all the math + + align:start position:0% +masts to laughing I should all the math + + + align:start position:0% +masts to laughing I should all the math +I have to hire many many students to + + align:start position:0% +I have to hire many many students to + + + align:start position:0% +I have to hire many many students to +smooth all the mess from lapin side of + + align:start position:0% +smooth all the mess from lapin side of + + + align:start position:0% +smooth all the mess from lapin side of +the universe to right hand side of the + + align:start position:0% +the universe to right hand side of the + + + align:start position:0% +the universe to right hand side of the +universe okay and after they have done + + align:start position:0% +universe okay and after they have done + + + align:start position:0% +universe okay and after they have done +that the system looks the same right + + align:start position:0% +that the system looks the same right + + + align:start position:0% +that the system looks the same right +that's very good okay after all the hard + + align:start position:0% +that's very good okay after all the hard + + + align:start position:0% +that's very good okay after all the hard +work right + + align:start position:0% +work right + + + align:start position:0% +work right +so what is issue going to be the + + align:start position:0% +so what is issue going to be the + + + align:start position:0% +so what is issue going to be the +symmetry matrix okay now I would like to + + align:start position:0% +symmetry matrix okay now I would like to + + + align:start position:0% +symmetry matrix okay now I would like to +achieve something which is a prong equal + + align:start position:0% +achieve something which is a prong equal + + + align:start position:0% +achieve something which is a prong equal +to s and that this s actually shipped + + align:start position:0% +to s and that this s actually shipped + + + align:start position:0% +to s and that this s actually shipped +the mass by a distance of a right so + + align:start position:0% +the mass by a distance of a right so + + + align:start position:0% +the mass by a distance of a right so +what would be the function of phony over + + align:start position:0% +what would be the function of phony over + + + align:start position:0% +what would be the function of phony over +this s matrix we were looks like this + + align:start position:0% +this s matrix we were looks like this + + + align:start position:0% +this s matrix we were looks like this +it's going to be 0 1 0 0 0 0 0 1 0 0 0 + + align:start position:0% + + + + align:start position:0% + +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +ok so the next two diagonal turn is all + + align:start position:0% +ok so the next two diagonal turn is all + + + align:start position:0% +ok so the next two diagonal turn is all +one all the rest of the component is 0 + + align:start position:0% +one all the rest of the component is 0 + + + align:start position:0% +one all the rest of the component is 0 +ok and this looks a lot more friendly + + align:start position:0% +ok and this looks a lot more friendly + + + align:start position:0% +ok and this looks a lot more friendly +compared to a mess 1 K matrix right see + + align:start position:0% +compared to a mess 1 K matrix right see + + + align:start position:0% +compared to a mess 1 K matrix right see +oh this is is this horrible thing to do + + align:start position:0% +oh this is is this horrible thing to do + + + align:start position:0% +oh this is is this horrible thing to do +because this is an infinite number of + + align:start position:0% +because this is an infinite number of + + + align:start position:0% +because this is an infinite number of +times in terminal number dimension + + align:start position:0% +times in terminal number dimension + + + align:start position:0% +times in terminal number dimension +matrix ok so we would like to find the + + align:start position:0% +matrix ok so we would like to find the + + + align:start position:0% +matrix ok so we would like to find the +eigen vectors of s matrix ok so this + + align:start position:0% +eigen vectors of s matrix ok so this + + + align:start position:0% +eigen vectors of s matrix ok so this +means that if I manage you to solve the + + align:start position:0% +means that if I manage you to solve the + + + align:start position:0% +means that if I manage you to solve the +eigenvalue problem assuming that ok I + + align:start position:0% +eigenvalue problem assuming that ok I + + + align:start position:0% +eigenvalue problem assuming that ok I +haven't solve it but I assuming that I + + align:start position:0% +haven't solve it but I assuming that I + + + align:start position:0% +haven't solve it but I assuming that I +can solve it + + align:start position:0% +can solve it + + + align:start position:0% +can solve it +ok then what I'm going to do is going to + + align:start position:0% +ok then what I'm going to do is going to + + + align:start position:0% +ok then what I'm going to do is going to +get this essay will be equal to theta + + align:start position:0% +get this essay will be equal to theta + + + align:start position:0% +get this essay will be equal to theta +where a is actually eigen vector of s + + align:start position:0% +where a is actually eigen vector of s + + + align:start position:0% +where a is actually eigen vector of s +matrix ok and and then si we just learn + + align:start position:0% +matrix ok and and then si we just learn + + + align:start position:0% +matrix ok and and then si we just learn +from here right it's actually equal to a + + align:start position:0% +from here right it's actually equal to a + + + align:start position:0% +from here right it's actually equal to a +prime so beta is the eigen value and a + + align:start position:0% +prime so beta is the eigen value and a + + + align:start position:0% +prime so beta is the eigen value and a +is actually the eigenvector + + align:start position:0% + + + + align:start position:0% + +so that means originally I have a which + + align:start position:0% +so that means originally I have a which + + + align:start position:0% +so that means originally I have a which +is something sensing a say it a plus one + + align:start position:0% +is something sensing a say it a plus one + + + align:start position:0% +is something sensing a say it a plus one +it's a plus two proper bra okay and the + + align:start position:0% +it's a plus two proper bra okay and the + + + align:start position:0% +it's a plus two proper bra okay and the +apron after I actually multiply a by s + + align:start position:0% +apron after I actually multiply a by s + + + align:start position:0% +apron after I actually multiply a by s +matrix I get a prompt which looks like + + align:start position:0% +matrix I get a prompt which looks like + + + align:start position:0% +matrix I get a prompt which looks like +this + + align:start position:0% +this + + + align:start position:0% +this +hey J plus 1 J plus 2 J plus 3 okay so + + align:start position:0% +hey J plus 1 J plus 2 J plus 3 okay so + + + align:start position:0% +hey J plus 1 J plus 2 J plus 3 okay so +what I'm going to do is what actually + + align:start position:0% +what I'm going to do is what actually + + + align:start position:0% +what I'm going to do is what actually +this S matrix does is to shift the a + + align:start position:0% +this S matrix does is to shift the a + + + align:start position:0% +this S matrix does is to shift the a +component by one one row right okay so + + align:start position:0% +component by one one row right okay so + + + align:start position:0% +component by one one row right okay so +then we basically get this expression + + align:start position:0% +then we basically get this expression + + + align:start position:0% +then we basically get this expression +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and of course a1 is equal to beta which + + align:start position:0% +and of course a1 is equal to beta which + + + align:start position:0% +and of course a1 is equal to beta which +is a constant I say right so if you + + align:start position:0% +is a constant I say right so if you + + + align:start position:0% +is a constant I say right so if you +compare for example here okay you can + + align:start position:0% +compare for example here okay you can + + + align:start position:0% +compare for example here okay you can +get that AJ prime will be equal to beta + + align:start position:0% +get that AJ prime will be equal to beta + + + align:start position:0% +get that AJ prime will be equal to beta +AJ which is actually equal to AJ plus + + align:start position:0% +AJ which is actually equal to AJ plus + + + align:start position:0% +AJ which is actually equal to AJ plus +one by AJ prime is actually equal to AJ + + align:start position:0% +one by AJ prime is actually equal to AJ + + + align:start position:0% +one by AJ prime is actually equal to AJ +plus one maybe it's just what shifting + + align:start position:0% +plus one maybe it's just what shifting + + + align:start position:0% +plus one maybe it's just what shifting +one you need you know label right okay + + align:start position:0% +one you need you know label right okay + + + align:start position:0% +one you need you know label right okay +so so this is the expression I am + + align:start position:0% +so so this is the expression I am + + + align:start position:0% +so so this is the expression I am +looking for okay we don't know yet what + + align:start position:0% +looking for okay we don't know yet what + + + align:start position:0% +looking for okay we don't know yet what +is H beta + + align:start position:0% +is H beta + + + align:start position:0% +is H beta +okay beta I sound number assuming that I + + align:start position:0% +okay beta I sound number assuming that I + + + align:start position:0% +okay beta I sound number assuming that I +can solve the eigenvalue problem okay + + align:start position:0% +can solve the eigenvalue problem okay + + + align:start position:0% +can solve the eigenvalue problem okay +but I do now if I have 8 0 if a 0 is + + align:start position:0% +but I do now if I have 8 0 if a 0 is + + + align:start position:0% +but I do now if I have 8 0 if a 0 is +equal to 0 + + align:start position:0% +equal to 0 + + + align:start position:0% +equal to 0 +okay from this this expression okay that + + align:start position:0% +okay from this this expression okay that + + + align:start position:0% +okay from this this expression okay that +means a 1 will be a 0 is equal to 1 if a + + align:start position:0% +means a 1 will be a 0 is equal to 1 if a + + + align:start position:0% +means a 1 will be a 0 is equal to 1 if a +0 is 0 then everything is 0 right and + + align:start position:0% +0 is 0 then everything is 0 right and + + + align:start position:0% +0 is 0 then everything is 0 right and +it's not right + + align:start position:0% +it's not right + + + align:start position:0% +it's not right +ok n 0 is equal to 1 then something will + + align:start position:0% +ok n 0 is equal to 1 then something will + + + align:start position:0% +ok n 0 is equal to 1 then something will +happen a 1 will be equal to beta right + + align:start position:0% +happen a 1 will be equal to beta right + + + align:start position:0% +happen a 1 will be equal to beta right +from this expression right because beta + + align:start position:0% +from this expression right because beta + + + align:start position:0% +from this expression right because beta +IJ is equal to 8 a plus 1 + + align:start position:0% +IJ is equal to 8 a plus 1 + + + align:start position:0% +IJ is equal to 8 a plus 1 +a two will be equal to beta square etc + + align:start position:0% +a two will be equal to beta square etc + + + align:start position:0% +a two will be equal to beta square etc +etc and I can say that + + align:start position:0% +etc and I can say that + + + align:start position:0% +etc and I can say that +AJ if I assume a 0 if 0 is equal to 1 + + align:start position:0% +AJ if I assume a 0 if 0 is equal to 1 + + + align:start position:0% +AJ if I assume a 0 if 0 is equal to 1 +then AJ will be equal to beta 2 details + + align:start position:0% +then AJ will be equal to beta 2 details + + + align:start position:0% +then AJ will be equal to beta 2 details +ok I going too fast here everybody is + + align:start position:0% +ok I going too fast here everybody is + + + align:start position:0% +ok I going too fast here everybody is +following your question no good and + + align:start position:0% +following your question no good and + + + align:start position:0% +following your question no good and +study we found that we have already + + align:start position:0% +study we found that we have already + + + align:start position:0% +study we found that we have already +solved that I can build your problem + + align:start position:0% +solved that I can build your problem + + + align:start position:0% +solved that I can build your problem +right because I have already the + + align:start position:0% +right because I have already the + + + align:start position:0% +right because I have already the +expression for the AJ which is actually + + align:start position:0% +expression for the AJ which is actually + + + align:start position:0% +expression for the AJ which is actually +in the form of beta to the tail right so + + align:start position:0% +in the form of beta to the tail right so + + + align:start position:0% +in the form of beta to the tail right so +beta is son I should some kind of number + + align:start position:0% +beta is son I should some kind of number + + + align:start position:0% +beta is son I should some kind of number +okay and the infinite number of beta + + align:start position:0% +okay and the infinite number of beta + + + align:start position:0% +okay and the infinite number of beta +actually can satisfy this eigenvalue + + align:start position:0% +actually can satisfy this eigenvalue + + + align:start position:0% +actually can satisfy this eigenvalue +problem no matter what kind of weight I + + align:start position:0% +problem no matter what kind of weight I + + + align:start position:0% +problem no matter what kind of weight I +choose it can be wine can be to 3.14 can + + align:start position:0% +choose it can be wine can be to 3.14 can + + + align:start position:0% +choose it can be wine can be to 3.14 can +be PI okay + + align:start position:0% +be PI okay + + + align:start position:0% +be PI okay +and what I'm going to get is the + + align:start position:0% +and what I'm going to get is the + + + align:start position:0% +and what I'm going to get is the +corresponding AJ corresponding a vector + + align:start position:0% +corresponding AJ corresponding a vector + + + align:start position:0% +corresponding AJ corresponding a vector +which will satisfy this expression okay + + align:start position:0% +which will satisfy this expression okay + + + align:start position:0% +which will satisfy this expression okay +so that means some magic happen we have + + align:start position:0% +so that means some magic happen we have + + + align:start position:0% +so that means some magic happen we have +already solved the eigenvalue poppin + + align:start position:0% +already solved the eigenvalue poppin + + + align:start position:0% +already solved the eigenvalue poppin +without really deriving you know a lot + + align:start position:0% +without really deriving you know a lot + + + align:start position:0% +without really deriving you know a lot +of deviation right a second e another + + align:start position:0% +of deviation right a second e another + + + align:start position:0% +of deviation right a second e another +thing which we learn is that they are + + align:start position:0% +thing which we learn is that they are + + + align:start position:0% +thing which we learn is that they are +infinite number of eigen value which + + align:start position:0% +infinite number of eigen value which + + + align:start position:0% +infinite number of eigen value which +satisfy the this item value problem the + + align:start position:0% +satisfy the this item value problem the + + + align:start position:0% +satisfy the this item value problem the +question is does that make sense or not + + align:start position:0% +question is does that make sense or not + + + align:start position:0% +question is does that make sense or not +infinite number of eigen values can + + align:start position:0% +infinite number of eigen values can + + + align:start position:0% +infinite number of eigen values can +actually satisfy this infinitely long + + align:start position:0% +actually satisfy this infinitely long + + + align:start position:0% +actually satisfy this infinitely long +system it's kind of making sense right + + align:start position:0% +system it's kind of making sense right + + + align:start position:0% +system it's kind of making sense right +because we have work on one oscillator + + align:start position:0% +because we have work on one oscillator + + + align:start position:0% +because we have work on one oscillator +you have one no more more - oscillator + + align:start position:0% +you have one no more more - oscillator + + + align:start position:0% +you have one no more more - oscillator +you have to know more more + + align:start position:0% +you have to know more more + + + align:start position:0% +you have to know more more +three oscillator you have seen no more + + align:start position:0% +three oscillator you have seen no more + + + align:start position:0% +three oscillator you have seen no more +more infinite number of oscillators + + align:start position:0% +more infinite number of oscillators + + + align:start position:0% +more infinite number of oscillators +you should have infinite number no more + + align:start position:0% +you should have infinite number no more + + + align:start position:0% +you should have infinite number no more +mode right + + align:start position:0% +mode right + + + align:start position:0% +mode right +okay so that is actually a very very + + align:start position:0% +okay so that is actually a very very + + + align:start position:0% +okay so that is actually a very very +good news because we have already saw + + align:start position:0% +good news because we have already saw + + + align:start position:0% +good news because we have already saw +the problem and we also know the + + align:start position:0% +the problem and we also know the + + + align:start position:0% +the problem and we also know the +functional form of eigenvectors okay so + + align:start position:0% +functional form of eigenvectors okay so + + + align:start position:0% +functional form of eigenvectors okay so +let's take a look at those example + + align:start position:0% +let's take a look at those example + + + align:start position:0% +let's take a look at those example +system which are actually close to + + align:start position:0% +system which are actually close to + + + align:start position:0% +system which are actually close to +infinitely long so here you have + + align:start position:0% +infinitely long so here you have + + + align:start position:0% +infinitely long so here you have +pelipper machine which usually app can + + align:start position:0% +pelipper machine which usually app can + + + align:start position:0% +pelipper machine which usually app can +have have actually multiple coupled + + align:start position:0% +have have actually multiple coupled + + + align:start position:0% +have have actually multiple coupled +oscillators each of each one of them can + + align:start position:0% +oscillators each of each one of them can + + + align:start position:0% +oscillators each of each one of them can +also they up and down and you can see + + align:start position:0% +also they up and down and you can see + + + align:start position:0% +also they up and down and you can see +that huh if I actually try to move them + + align:start position:0% +that huh if I actually try to move them + + + align:start position:0% +that huh if I actually try to move them +up and down they're complicated kind of + + align:start position:0% +up and down they're complicated kind of + + + align:start position:0% +up and down they're complicated kind of +motion can occur from this system + + align:start position:0% +motion can occur from this system + + + align:start position:0% +motion can occur from this system +actually if I do this and you see the + + align:start position:0% +actually if I do this and you see the + + + align:start position:0% +actually if I do this and you see the +idea something similar to wave is + + align:start position:0% +idea something similar to wave is + + + align:start position:0% +idea something similar to wave is +happening and if I do this continuously + + align:start position:0% +happening and if I do this continuously + + + align:start position:0% +happening and if I do this continuously +oh some kind of kind of like a standing + + align:start position:0% +oh some kind of kind of like a standing + + + align:start position:0% +oh some kind of kind of like a standing +wave is produced right and this system + + align:start position:0% +wave is produced right and this system + + + align:start position:0% +wave is produced right and this system +is actually really really hard to + + align:start position:0% +is actually really really hard to + + + align:start position:0% +is actually really really hard to +describe right if if I if I look at how + + align:start position:0% +describe right if if I if I look at how + + + align:start position:0% +describe right if if I if I look at how +how many since this system can actually + + align:start position:0% +how many since this system can actually + + + align:start position:0% +how many since this system can actually +do okay + + align:start position:0% +do okay + + + align:start position:0% +do okay +another example is actually okay so you + + align:start position:0% +another example is actually okay so you + + + align:start position:0% +another example is actually okay so you +can say come on this is actually not + + align:start position:0% +can say come on this is actually not + + + align:start position:0% +can say come on this is actually not +infinitely long sister right you have to + + align:start position:0% +infinitely long sister right you have to + + + align:start position:0% +infinitely long sister right you have to +find a number right so how about I use + + align:start position:0% +find a number right so how about I use + + + align:start position:0% +find a number right so how about I use +this system as a demonstration this is + + align:start position:0% +this system as a demonstration this is + + + align:start position:0% +this system as a demonstration this is +actually a much nicer or much better + + align:start position:0% +actually a much nicer or much better + + + align:start position:0% +actually a much nicer or much better +approximation okay to to an infinitely + + align:start position:0% +approximation okay to to an infinitely + + + align:start position:0% +approximation okay to to an infinitely +long system you can see that okay each + + align:start position:0% +long system you can see that okay each + + + align:start position:0% +long system you can see that okay each +mass each okay I can say for example + + align:start position:0% +mass each okay I can say for example + + + align:start position:0% +mass each okay I can say for example +each small component of the spring it's + + align:start position:0% +each small component of the spring it's + + + align:start position:0% +each small component of the spring it's +actually can be considered as a small + + align:start position:0% +actually can be considered as a small + + + align:start position:0% +actually can be considered as a small +and in my in my right and the issue act + + align:start position:0% +and in my in my right and the issue act + + + align:start position:0% +and in my in my right and the issue act +now I can actually instead of + + align:start position:0% +now I can actually instead of + + + align:start position:0% +now I can actually instead of +oscillating then pactum force I + + align:start position:0% +oscillating then pactum force I + + + align:start position:0% +oscillating then pactum force I +oscillate an upside down okay you can + + align:start position:0% +oscillate an upside down okay you can + + + align:start position:0% +oscillate an upside down okay you can +see that hand they are interesting kind + + align:start position:0% +see that hand they are interesting kind + + + align:start position:0% +see that hand they are interesting kind +of motion I can have okay + + align:start position:0% +of motion I can have okay + + + align:start position:0% +of motion I can have okay +this which is like a standing wave I can + + align:start position:0% +this which is like a standing wave I can + + + align:start position:0% +this which is like a standing wave I can +I can do this I can stop this system and + + align:start position:0% +I can do this I can stop this system and + + + align:start position:0% +I can do this I can stop this system and +like produce whoo I can produce a wave + + align:start position:0% +like produce whoo I can produce a wave + + + align:start position:0% +like produce whoo I can produce a wave +and it goes back and forth and I can do + + align:start position:0% +and it goes back and forth and I can do + + + align:start position:0% +and it goes back and forth and I can do +this like crazy then you see that + + align:start position:0% +this like crazy then you see that + + + align:start position:0% +this like crazy then you see that +exciting a much higher frequency normal + + align:start position:0% +exciting a much higher frequency normal + + + align:start position:0% +exciting a much higher frequency normal +mode right and that's really complicated + + align:start position:0% +mode right and that's really complicated + + + align:start position:0% +mode right and that's really complicated +and I the question is how can we + + align:start position:0% +and I the question is how can we + + + align:start position:0% +and I the question is how can we +actually understand this kind of system + + align:start position:0% +actually understand this kind of system + + + align:start position:0% +actually understand this kind of system +it seems that this system is so much so + + align:start position:0% +it seems that this system is so much so + + + align:start position:0% +it seems that this system is so much so +complicated and have infinite amount of + + align:start position:0% +complicated and have infinite amount of + + + align:start position:0% +complicated and have infinite amount of +possibilities right so how are we going + + align:start position:0% +possibilities right so how are we going + + + align:start position:0% +possibilities right so how are we going +to understand this very good news is + + align:start position:0% +to understand this very good news is + + + align:start position:0% +to understand this very good news is +that we have solved the normal mode of + + align:start position:0% +that we have solved the normal mode of + + + align:start position:0% +that we have solved the normal mode of +this kind of system right so the normal + + align:start position:0% +this kind of system right so the normal + + + align:start position:0% +this kind of system right so the normal +mode looks like this AJ equal to beta J + + align:start position:0% +mode looks like this AJ equal to beta J + + + align:start position:0% +mode looks like this AJ equal to beta J +ok and the following lecture the rest of + + align:start position:0% +ok and the following lecture the rest of + + + align:start position:0% +ok and the following lecture the rest of +the lecture is to understand what does + + align:start position:0% +the lecture is to understand what does + + + align:start position:0% +the lecture is to understand what does +that mean and also make petitions ok so + + align:start position:0% +that mean and also make petitions ok so + + + align:start position:0% +that mean and also make petitions ok so +so now we have actually the eigen + + align:start position:0% +so now we have actually the eigen + + + align:start position:0% +so now we have actually the eigen +vectors ok that's really nice so from + + align:start position:0% +vectors ok that's really nice so from + + + align:start position:0% +vectors ok that's really nice so from +our previous discussion if this system + + align:start position:0% +our previous discussion if this system + + + align:start position:0% +our previous discussion if this system +actually satisfy the symmetry have the + + align:start position:0% +actually satisfy the symmetry have the + + + align:start position:0% +actually satisfy the symmetry have the +symmetry it is quite by the S matrix + + align:start position:0% +symmetry it is quite by the S matrix + + + align:start position:0% +symmetry it is quite by the S matrix +which I have here that means n minus 1 K + + align:start position:0% +which I have here that means n minus 1 K + + + align:start position:0% +which I have here that means n minus 1 K +matrix where share the same sets of + + align:start position:0% +matrix where share the same sets of + + + align:start position:0% +matrix where share the same sets of +eigenvectors as matrix right so what + + align:start position:0% +eigenvectors as matrix right so what + + + align:start position:0% +eigenvectors as matrix right so what +this actually the rest part of the work + + align:start position:0% +this actually the rest part of the work + + + align:start position:0% +this actually the rest part of the work +is to evaluate this n minus 1 K + + align:start position:0% +is to evaluate this n minus 1 K + + + align:start position:0% +is to evaluate this n minus 1 K +multiplied by a and that will give you + + align:start position:0% +multiplied by a and that will give you + + + align:start position:0% +multiplied by a and that will give you +Omega square H ok so I just need to + + align:start position:0% +Omega square H ok so I just need to + + + align:start position:0% +Omega square H ok so I just need to +multiply M minus 1 K matrix by a what is + + align:start position:0% +multiply M minus 1 K matrix by a what is + + + align:start position:0% +multiply M minus 1 K matrix by a what is +a is here right now what decision M + + align:start position:0% +a is here right now what decision M + + + align:start position:0% +a is here right now what decision M +minus 1 K matrix and when M minus 1 K + + align:start position:0% +minus 1 K matrix and when M minus 1 K + + + align:start position:0% +minus 1 K matrix and when M minus 1 K +matrix is here have a kind of + + align:start position:0% +matrix is here have a kind of + + + align:start position:0% +matrix is here have a kind of +complicated structure + + align:start position:0% +complicated structure + + + align:start position:0% +complicated structure +okay on the other hand if I only focus + + align:start position:0% +okay on the other hand if I only focus + + + align:start position:0% +okay on the other hand if I only focus +on the taste object okay the object + + align:start position:0% +on the taste object okay the object + + + align:start position:0% +on the taste object okay the object +which is named they have the label say + + align:start position:0% +which is named they have the label say + + + align:start position:0% +which is named they have the label say +okay then + + align:start position:0% +okay then + + + align:start position:0% +okay then +actually I can write down okay the right + + align:start position:0% +actually I can write down okay the right + + + align:start position:0% +actually I can write down okay the right +hand side is a she's just Omega square a + + align:start position:0% +hand side is a she's just Omega square a + + + align:start position:0% +hand side is a she's just Omega square a +say alright because this is actually + + align:start position:0% +say alright because this is actually + + + align:start position:0% +say alright because this is actually +just if I only focus on that there's a + + align:start position:0% +just if I only focus on that there's a + + + align:start position:0% +just if I only focus on that there's a +component okay + + align:start position:0% +component okay + + + align:start position:0% +component okay +lamp inside essentially just ms 1k a x a + + align:start position:0% +lamp inside essentially just ms 1k a x a + + + align:start position:0% +lamp inside essentially just ms 1k a x a +right okay so basically only there are + + align:start position:0% +right okay so basically only there are + + + align:start position:0% +right okay so basically only there are +only three turns coming to pray right if + + align:start position:0% +only three turns coming to pray right if + + + align:start position:0% +only three turns coming to pray right if +this is a 2-1 so 18 minus one will + + align:start position:0% +this is a 2-1 so 18 minus one will + + + align:start position:0% +this is a 2-1 so 18 minus one will +multiply 5 minus K over N AJ work + + align:start position:0% +multiply 5 minus K over N AJ work + + + align:start position:0% +multiply 5 minus K over N AJ work +multiplied by 2 K over N and AJ past one + + align:start position:0% +multiplied by 2 K over N and AJ past one + + + align:start position:0% +multiplied by 2 K over N and AJ past one +will multiply by minus K over N right + + align:start position:0% +will multiply by minus K over N right + + + align:start position:0% +will multiply by minus K over N right +the rest of the turns are all 0 + + align:start position:0% +the rest of the turns are all 0 + + + align:start position:0% +the rest of the turns are all 0 +okay it's actually not as complicated as + + align:start position:0% +okay it's actually not as complicated as + + + align:start position:0% +okay it's actually not as complicated as +we sought ok so if I write it down + + align:start position:0% +we sought ok so if I write it down + + + align:start position:0% +we sought ok so if I write it down +explicitly the left hand side part then + + align:start position:0% +explicitly the left hand side part then + + + align:start position:0% +explicitly the left hand side part then +what I'm going to get is minus K over N + + align:start position:0% +what I'm going to get is minus K over N + + + align:start position:0% +what I'm going to get is minus K over N +capital K over N AJ minus one price to + + align:start position:0% +capital K over N AJ minus one price to + + + align:start position:0% +capital K over N AJ minus one price to +capital K over N AJ minus capital K over + + align:start position:0% +capital K over N AJ minus capital K over + + + align:start position:0% +capital K over N AJ minus capital K over +N it's a plus 1 okay so this is actually + + align:start position:0% +N it's a plus 1 okay so this is actually + + + align:start position:0% +N it's a plus 1 okay so this is actually +the day's time okay now I can define + + align:start position:0% +the day's time okay now I can define + + + align:start position:0% +the day's time okay now I can define +Omega 0 square equal it's defined as + + align:start position:0% +Omega 0 square equal it's defined as + + + align:start position:0% +Omega 0 square equal it's defined as +capital K over N if I do that then + + align:start position:0% +capital K over N if I do that then + + + align:start position:0% +capital K over N if I do that then +basically I can I can see that Omega + + align:start position:0% +basically I can I can see that Omega + + + align:start position:0% +basically I can I can see that Omega +square AJ would be equal to Omega 0 + + align:start position:0% +square AJ would be equal to Omega 0 + + + align:start position:0% +square AJ would be equal to Omega 0 +square okay I'm taking all the way over + + align:start position:0% +square okay I'm taking all the way over + + + align:start position:0% +square okay I'm taking all the way over +and out of the game and the lighted tag + + align:start position:0% +and out of the game and the lighted tag + + + align:start position:0% +and out of the game and the lighted tag +is Omega 0 square okay + + align:start position:0% +is Omega 0 square okay + + + align:start position:0% +is Omega 0 square okay +- 8a minus 1 plus 2 AJ - AJ possible + + align:start position:0% +- 8a minus 1 plus 2 AJ - AJ possible + + + align:start position:0% +- 8a minus 1 plus 2 AJ - AJ possible +okay and also we know from the previous + + align:start position:0% +okay and also we know from the previous + + + align:start position:0% +okay and also we know from the previous +discussion s matrix and the N minus 1 K + + align:start position:0% +discussion s matrix and the N minus 1 K + + + align:start position:0% +discussion s matrix and the N minus 1 K +matrix should share the same sets of + + align:start position:0% +matrix should share the same sets of + + + align:start position:0% +matrix should share the same sets of +eigenvectors therefore I can actually + + align:start position:0% +eigenvectors therefore I can actually + + + align:start position:0% +eigenvectors therefore I can actually +try to proc in one of the eigenvector + + align:start position:0% +try to proc in one of the eigenvector + + + align:start position:0% +try to proc in one of the eigenvector +from s matrix right AJ equal to beta J + + align:start position:0% +from s matrix right AJ equal to beta J + + + align:start position:0% +from s matrix right AJ equal to beta J +okay I can Proctor then basically I get + + align:start position:0% +okay I can Proctor then basically I get + + + align:start position:0% +okay I can Proctor then basically I get +Omega 0 square minus P minus beta J + + align:start position:0% +Omega 0 square minus P minus beta J + + + align:start position:0% +Omega 0 square minus P minus beta J +minus 1 plus 2 beta 2 DJ minus beta J + + align:start position:0% +minus 1 plus 2 beta 2 DJ minus beta J + + + align:start position:0% +minus 1 plus 2 beta 2 DJ minus beta J +plus 1 and the left hand side will be + + align:start position:0% +plus 1 and the left hand side will be + + + align:start position:0% +plus 1 and the left hand side will be +knitting like Omega square beta to the + + align:start position:0% +knitting like Omega square beta to the + + + align:start position:0% +knitting like Omega square beta to the +chain okay questions okay + + align:start position:0% +chain okay questions okay + + + align:start position:0% +chain okay questions okay +so now I can cancel I can actually + + align:start position:0% +so now I can cancel I can actually + + + align:start position:0% +so now I can cancel I can actually +divide everything by beta to each a + + align:start position:0% +divide everything by beta to each a + + + align:start position:0% +divide everything by beta to each a +right I can get rid of a tattoo it's a + + align:start position:0% +right I can get rid of a tattoo it's a + + + align:start position:0% +right I can get rid of a tattoo it's a +then basically I get omega squared equal + + align:start position:0% +then basically I get omega squared equal + + + align:start position:0% +then basically I get omega squared equal +to Omega 0 square minus 1 over beta plus + + align:start position:0% +to Omega 0 square minus 1 over beta plus + + + align:start position:0% +to Omega 0 square minus 1 over beta plus + + align:start position:0% + + + align:start position:0% +- okay and as we discussed before beta + + align:start position:0% +- okay and as we discussed before beta + + + align:start position:0% +- okay and as we discussed before beta +can have any value okay and also you can + + align:start position:0% +can have any value okay and also you can + + + align:start position:0% +can have any value okay and also you can +see from here that huh once I know the + + align:start position:0% +see from here that huh once I know the + + + align:start position:0% +see from here that huh once I know the +icon value of s matrix and eigen vector + + align:start position:0% +icon value of s matrix and eigen vector + + + align:start position:0% +icon value of s matrix and eigen vector +or matrix I also know what this entry + + align:start position:0% +or matrix I also know what this entry + + + align:start position:0% +or matrix I also know what this entry +the corresponding angular frequency of + + align:start position:0% +the corresponding angular frequency of + + + align:start position:0% +the corresponding angular frequency of +the normal model right by using n minus + + align:start position:0% +the normal model right by using n minus + + + align:start position:0% +the normal model right by using n minus +1 K times a you can figure out what is + + align:start position:0% +1 K times a you can figure out what is + + + align:start position:0% +1 K times a you can figure out what is +actually the corresponding Omega the + + align:start position:0% +actually the corresponding Omega the + + + align:start position:0% +actually the corresponding Omega the +normal mode frequency okay so that is + + align:start position:0% +normal mode frequency okay so that is + + + align:start position:0% +normal mode frequency okay so that is +actually pretty nice but on the other + + align:start position:0% +actually pretty nice but on the other + + + align:start position:0% +actually pretty nice but on the other +hand if you step back and the sync about + + align:start position:0% +hand if you step back and the sync about + + + align:start position:0% +hand if you step back and the sync about +what we have been doing okay so very + + align:start position:0% +what we have been doing okay so very + + + align:start position:0% +what we have been doing okay so very +good you have a beta which is a random + + align:start position:0% +good you have a beta which is a random + + + align:start position:0% +good you have a beta which is a random +value you can evaluate this is C then + + align:start position:0% +value you can evaluate this is C then + + + align:start position:0% +value you can evaluate this is C then +you can get the corresponding Omega with + + align:start position:0% +you can get the corresponding Omega with + + + align:start position:0% +you can get the corresponding Omega with +that but this something doesn't feel + + align:start position:0% +that but this something doesn't feel + + + align:start position:0% +that but this something doesn't feel +right right for example if you have beta + + align:start position:0% +right right for example if you have beta + + + align:start position:0% +right right for example if you have beta +equal to 2 what is going to happen if + + align:start position:0% +equal to 2 what is going to happen if + + + align:start position:0% +equal to 2 what is going to happen if +you have beta equal to 2 what does that + + align:start position:0% +you have beta equal to 2 what does that + + + align:start position:0% +you have beta equal to 2 what does that +mean that means a day will be equal to 2 + + align:start position:0% +mean that means a day will be equal to 2 + + + align:start position:0% +mean that means a day will be equal to 2 +to DJ okay that's very dangerous + + align:start position:0% +to DJ okay that's very dangerous + + + align:start position:0% +to DJ okay that's very dangerous +hey that means okay so I am I deployed + + align:start position:0% +hey that means okay so I am I deployed + + + align:start position:0% +hey that means okay so I am I deployed +the whole system okay from the lapin + + align:start position:0% +the whole system okay from the lapin + + + align:start position:0% +the whole system okay from the lapin +side of the new universe to the + + align:start position:0% +side of the new universe to the + + + align:start position:0% +side of the new universe to the +right-hand side of the universe okay so + + align:start position:0% +right-hand side of the universe okay so + + + align:start position:0% +right-hand side of the universe okay so +now means if I go to the the + + align:start position:0% +now means if I go to the the + + + align:start position:0% +now means if I go to the the +your right-hand side of the universe + + align:start position:0% +your right-hand side of the universe + + + align:start position:0% +your right-hand side of the universe +okay the amplitude explode right it's + + align:start position:0% +okay the amplitude explode right it's + + + align:start position:0% +okay the amplitude explode right it's +actually two to the infini number right + + align:start position:0% +actually two to the infini number right + + + align:start position:0% +actually two to the infini number right +okay it's now physics doesn't sound like + + align:start position:0% +okay it's now physics doesn't sound like + + + align:start position:0% +okay it's now physics doesn't sound like +a physical system to me right if + + align:start position:0% +a physical system to me right if + + + align:start position:0% +a physical system to me right if +actually beta is greater than one then + + align:start position:0% +actually beta is greater than one then + + + align:start position:0% +actually beta is greater than one then +the right-hand side edge of the universe + + align:start position:0% +the right-hand side edge of the universe + + + align:start position:0% +the right-hand side edge of the universe +the Emperor to there will explode okay + + align:start position:0% +the Emperor to there will explode okay + + + align:start position:0% +the Emperor to there will explode okay +doesn't sound right right so I don't + + align:start position:0% +doesn't sound right right so I don't + + + align:start position:0% +doesn't sound right right so I don't +like that okay maybe you like it but I I + + align:start position:0% +like that okay maybe you like it but I I + + + align:start position:0% +like that okay maybe you like it but I I +don't like it for the moment on the + + align:start position:0% +don't like it for the moment on the + + + align:start position:0% +don't like it for the moment on the +other hand if the beta okay again it's + + align:start position:0% +other hand if the beta okay again it's + + + align:start position:0% +other hand if the beta okay again it's +not one but some other than one what is + + align:start position:0% +not one but some other than one what is + + + align:start position:0% +not one but some other than one what is +going to happen if the beta is smoother + + align:start position:0% +going to happen if the beta is smoother + + + align:start position:0% +going to happen if the beta is smoother +than one what is going to happen is that + + align:start position:0% +than one what is going to happen is that + + + align:start position:0% +than one what is going to happen is that +huh okay + + align:start position:0% +huh okay + + + align:start position:0% +huh okay +the right-hand side universe is fine is + + align:start position:0% +the right-hand side universe is fine is + + + align:start position:0% +the right-hand side universe is fine is +finite because the amplitudes become + + align:start position:0% +finite because the amplitudes become + + + align:start position:0% +finite because the amplitudes become +smaller and smaller but the Lavin's are + + align:start position:0% +smaller and smaller but the Lavin's are + + + align:start position:0% +smaller and smaller but the Lavin's are +part of the universe the amplitude still + + align:start position:0% +part of the universe the amplitude still + + + align:start position:0% +part of the universe the amplitude still +explode right so what does that mean + + align:start position:0% +explode right so what does that mean + + + align:start position:0% +explode right so what does that mean +this means that if beta if the absolute + + align:start position:0% +this means that if beta if the absolute + + + align:start position:0% +this means that if beta if the absolute +value of beta is not equal to one the + + align:start position:0% +value of beta is not equal to one the + + + align:start position:0% +value of beta is not equal to one the +amplitude at some point goes to infinity + + align:start position:0% +amplitude at some point goes to infinity + + + align:start position:0% +amplitude at some point goes to infinity +okay so that's actually not very nice + + align:start position:0% +okay so that's actually not very nice + + + align:start position:0% +okay so that's actually not very nice +that's because AJ is actually + + align:start position:0% +that's because AJ is actually + + + align:start position:0% +that's because AJ is actually +proportional to beta to you take okay so + + align:start position:0% +proportional to beta to you take okay so + + + align:start position:0% +proportional to beta to you take okay so +in the discussion we have here we + + align:start position:0% +in the discussion we have here we + + + align:start position:0% +in the discussion we have here we +consider beta equal to one case + + align:start position:0% +consider beta equal to one case + + + align:start position:0% +consider beta equal to one case +okay otherwise this actually things will + + align:start position:0% +okay otherwise this actually things will + + + align:start position:0% +okay otherwise this actually things will +explode + + align:start position:0% +explode + + + align:start position:0% +explode +okay so if the absolute value of beta is + + align:start position:0% +okay so if the absolute value of beta is + + + align:start position:0% +okay so if the absolute value of beta is +equal to one in general beta can be + + align:start position:0% +equal to one in general beta can be + + + align:start position:0% +equal to one in general beta can be +exponential I smoke a a right then + + align:start position:0% +exponential I smoke a a right then + + + align:start position:0% +exponential I smoke a a right then +usually you can edges get absolute value + + align:start position:0% +usually you can edges get absolute value + + + align:start position:0% +usually you can edges get absolute value +of one okay if beta is equal to one that + + align:start position:0% +of one okay if beta is equal to one that + + + align:start position:0% +of one okay if beta is equal to one that +means the amplitude of all the + + align:start position:0% +means the amplitude of all the + + + align:start position:0% +means the amplitude of all the +oscillators are the same okay + + align:start position:0% +oscillators are the same okay + + + align:start position:0% +oscillators are the same okay +all right so now if if we accept this we + + align:start position:0% +all right so now if if we accept this we + + + align:start position:0% +all right so now if if we accept this we +only limit ourselves to the discussion + + align:start position:0% +only limit ourselves to the discussion + + + align:start position:0% +only limit ourselves to the discussion +of beta absolute beta value of beta + + align:start position:0% +of beta absolute beta value of beta + + + align:start position:0% +of beta absolute beta value of beta +equal to 1 then beta can be written as + + align:start position:0% +equal to 1 then beta can be written as + + + align:start position:0% +equal to 1 then beta can be written as +exponential I K a that if I practice + + align:start position:0% +exponential I K a that if I practice + + + align:start position:0% +exponential I K a that if I practice +back into this basically what you are + + align:start position:0% +back into this basically what you are + + + align:start position:0% +back into this basically what you are +going to get is Omega square is equal to + + align:start position:0% +going to get is Omega square is equal to + + + align:start position:0% +going to get is Omega square is equal to +Omega 0 square 2 minus exponential I K a + + align:start position:0% + + + + align:start position:0% + +plus exponential minus I K right because + + align:start position:0% +plus exponential minus I K right because + + + align:start position:0% +plus exponential minus I K right because +you have minus 1 over beta the beta + + align:start position:0% +you have minus 1 over beta the beta + + + align:start position:0% +you have minus 1 over beta the beta +therefore you have exponential I K a and + + align:start position:0% +therefore you have exponential I K a and + + + align:start position:0% +therefore you have exponential I K a and +the exponential minus I theta ok it's a + + align:start position:0% +the exponential minus I theta ok it's a + + + align:start position:0% +the exponential minus I theta ok it's a +lot of math in this the this lecture but + + align:start position:0% +lot of math in this the this lecture but + + + align:start position:0% +lot of math in this the this lecture but +I we are getting all over to it ok all + + align:start position:0% +I we are getting all over to it ok all + + + align:start position:0% +I we are getting all over to it ok all +right so that essentially we actually + + align:start position:0% +right so that essentially we actually + + + align:start position:0% +right so that essentially we actually +can identify this and this issue can be + + align:start position:0% +can identify this and this issue can be + + + align:start position:0% +can identify this and this issue can be +written as 2 Omega 0 Square 1 minus + + align:start position:0% +written as 2 Omega 0 Square 1 minus + + + align:start position:0% +written as 2 Omega 0 Square 1 minus +cosine K ok we have arrived a + + align:start position:0% +cosine K ok we have arrived a + + + align:start position:0% +cosine K ok we have arrived a +surprisingly simple expression + + align:start position:0% + + + + align:start position:0% + +so let's take a look at this expression + + align:start position:0% +so let's take a look at this expression + + + align:start position:0% +so let's take a look at this expression +carefully so that means for each given K + + align:start position:0% +carefully so that means for each given K + + + align:start position:0% +carefully so that means for each given K +small K okay then we have a + + align:start position:0% +small K okay then we have a + + + align:start position:0% +small K okay then we have a +corresponding angular frequency Omega + + align:start position:0% +corresponding angular frequency Omega + + + align:start position:0% +corresponding angular frequency Omega +square okay so still there are infinite + + align:start position:0% +square okay so still there are infinite + + + align:start position:0% +square okay so still there are infinite +number of we are infinite number of + + align:start position:0% +number of we are infinite number of + + + align:start position:0% +number of we are infinite number of +possible normal modes okay from this so + + align:start position:0% +possible normal modes okay from this so + + + align:start position:0% +possible normal modes okay from this so +if I take a look at the amplitude okay + + align:start position:0% +if I take a look at the amplitude okay + + + align:start position:0% +if I take a look at the amplitude okay +so if I I select a K value okay + + align:start position:0% +so if I I select a K value okay + + + align:start position:0% +so if I I select a K value okay +small K value if I if K is given I can + + align:start position:0% +small K value if I if K is given I can + + + align:start position:0% +small K value if I if K is given I can +actually calculate that K is found in a + + align:start position:0% +actually calculate that K is found in a + + + align:start position:0% +actually calculate that K is found in a +day so that a day I can actually define + + align:start position:0% +day so that a day I can actually define + + + align:start position:0% +day so that a day I can actually define +as a superposition of exponential I take + + align:start position:0% +as a superposition of exponential I take + + + align:start position:0% +as a superposition of exponential I take +K a and minus exponential I J okay + + align:start position:0% +K a and minus exponential I J okay + + + align:start position:0% +K a and minus exponential I J okay +and now will give you a sinusoidal shape + + align:start position:0% + + + + align:start position:0% + +so if I give you the K okay basically + + align:start position:0% +so if I give you the K okay basically + + + align:start position:0% +so if I give you the K okay basically +you will see that if I give you it okay + + align:start position:0% +you will see that if I give you it okay + + + align:start position:0% +you will see that if I give you it okay +then you you get a corresponding beta + + align:start position:0% +then you you get a corresponding beta + + + align:start position:0% +then you you get a corresponding beta +right and the you get you are going to + + align:start position:0% +right and the you get you are going to + + + align:start position:0% +right and the you get you are going to +get Omega the corresponding Omega square + + align:start position:0% +get Omega the corresponding Omega square + + + align:start position:0% +get Omega the corresponding Omega square +but one interesting C of this expression + + align:start position:0% +but one interesting C of this expression + + + align:start position:0% +but one interesting C of this expression +is that if you keep beta or keep you + + align:start position:0% +is that if you keep beta or keep you + + + align:start position:0% +is that if you keep beta or keep you +keep one over beta you are going to get + + align:start position:0% +keep one over beta you are going to get + + + align:start position:0% +keep one over beta you are going to get +the same Omega therefore I can now use + + align:start position:0% +the same Omega therefore I can now use + + + align:start position:0% +the same Omega therefore I can now use +superposition principle basically I can + + align:start position:0% +superposition principle basically I can + + + align:start position:0% +superposition principle basically I can +actually add this to solution together + + align:start position:0% +actually add this to solution together + + + align:start position:0% +actually add this to solution together +since they are going to be oscillating + + align:start position:0% +since they are going to be oscillating + + + align:start position:0% +since they are going to be oscillating +at the same frequency then what I am + + align:start position:0% +at the same frequency then what I am + + + align:start position:0% +at the same frequency then what I am +going to get is that huh interesting + + align:start position:0% +going to get is that huh interesting + + + align:start position:0% +going to get is that huh interesting +thing happen the AJ the amplitude as a + + align:start position:0% +thing happen the AJ the amplitude as a + + + align:start position:0% +thing happen the AJ the amplitude as a +function of J is like a sinusoidal + + align:start position:0% +function of J is like a sinusoidal + + + align:start position:0% +function of J is like a sinusoidal +function okay so that is essentially + + align:start position:0% +function okay so that is essentially + + + align:start position:0% +function okay so that is essentially +what is a really predicted to infinite + + align:start position:0% +what is a really predicted to infinite + + + align:start position:0% +what is a really predicted to infinite +long system for example if I do this you + + align:start position:0% +long system for example if I do this you + + + align:start position:0% +long system for example if I do this you +can see that hi indeed I can see + + align:start position:0% +can see that hi indeed I can see + + + align:start position:0% +can see that hi indeed I can see +sinusoidal shape okay and and you can + + align:start position:0% +sinusoidal shape okay and and you can + + + align:start position:0% +sinusoidal shape okay and and you can +see that this sinusoidal shape is + + align:start position:0% +see that this sinusoidal shape is + + + align:start position:0% +see that this sinusoidal shape is +actually oscillating up and down like a + + align:start position:0% +actually oscillating up and down like a + + + align:start position:0% +actually oscillating up and down like a +know like a standing wave and that is + + align:start position:0% +know like a standing wave and that is + + + align:start position:0% +know like a standing wave and that is +actually exactly this expression so that + + align:start position:0% +actually exactly this expression so that + + + align:start position:0% +actually exactly this expression so that +tells you something really interesting + + align:start position:0% +tells you something really interesting + + + align:start position:0% +tells you something really interesting +that means this sign so little shape is + + align:start position:0% +that means this sign so little shape is + + + align:start position:0% +that means this sign so little shape is +associated with what associated with + + align:start position:0% +associated with what associated with + + + align:start position:0% +associated with what associated with +translation symmetry right all I have + + align:start position:0% +translation symmetry right all I have + + + align:start position:0% +translation symmetry right all I have +been doing is to require this + + align:start position:0% +been doing is to require this + + + align:start position:0% +been doing is to require this +translation symmetry then you already + + align:start position:0% +translation symmetry then you already + + + align:start position:0% +translation symmetry then you already +get the amplitude AJ and if you choose + + align:start position:0% +get the amplitude AJ and if you choose + + + align:start position:0% +get the amplitude AJ and if you choose +the physical beta value then you already + + align:start position:0% +the physical beta value then you already + + + align:start position:0% +the physical beta value then you already +immediately arrive a solution which is + + align:start position:0% +immediately arrive a solution which is + + + align:start position:0% +immediately arrive a solution which is +actually like sinusoidal shape that + + align:start position:0% +actually like sinusoidal shape that + + + align:start position:0% +actually like sinusoidal shape that +sounds really amazing to you + + align:start position:0% + + + + align:start position:0% + +okay so I think it's time to good to + + align:start position:0% +okay so I think it's time to good to + + + align:start position:0% +okay so I think it's time to good to +take a five-minute break because I can + + align:start position:0% +take a five-minute break because I can + + + align:start position:0% +take a five-minute break because I can +see that you are overwhelmed by the mess + + align:start position:0% +see that you are overwhelmed by the mess + + + align:start position:0% +see that you are overwhelmed by the mess +already + + align:start position:0% +already + + + align:start position:0% +already +and of course let's come back in five + + align:start position:0% +and of course let's come back in five + + + align:start position:0% +and of course let's come back in five +minutes then we can discuss some more + + align:start position:0% +minutes then we can discuss some more + + + align:start position:0% +minutes then we can discuss some more +about what we have learned from this + + align:start position:0% +about what we have learned from this + + + align:start position:0% +about what we have learned from this +mathematics and if you have any + + align:start position:0% +mathematics and if you have any + + + align:start position:0% +mathematics and if you have any +questions + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +everybody of course you are welcome to + + align:start position:0% +everybody of course you are welcome to + + + align:start position:0% +everybody of course you are welcome to +come back here and the prayer with the + + align:start position:0% +come back here and the prayer with the + + + align:start position:0% +come back here and the prayer with the +demonstration okay so so very good so + + align:start position:0% +demonstration okay so so very good so + + + align:start position:0% +demonstration okay so so very good so +during the break there are several + + align:start position:0% +during the break there are several + + + align:start position:0% +during the break there are several +questions asked which i think is no + + align:start position:0% +questions asked which i think is no + + + align:start position:0% +questions asked which i think is no +those are very good questions and that's + + align:start position:0% +those are very good questions and that's + + + align:start position:0% +those are very good questions and that's +actually the purpose of this break so + + align:start position:0% +actually the purpose of this break so + + + align:start position:0% +actually the purpose of this break so +it's a long day already right a lot of + + align:start position:0% +it's a long day already right a lot of + + + align:start position:0% +it's a long day already right a lot of +mathematics and I hope everybody + + align:start position:0% +mathematics and I hope everybody + + + align:start position:0% +mathematics and I hope everybody +survived + + align:start position:0% +survived + + + align:start position:0% +survived +okay no dead body yet okay you can see + + align:start position:0% +okay no dead body yet okay you can see + + + align:start position:0% +okay no dead body yet okay you can see +that here I'm doing something really + + align:start position:0% +that here I'm doing something really + + + align:start position:0% +that here I'm doing something really +crazy here so okay consider okay I think + + align:start position:0% +crazy here so okay consider okay I think + + + align:start position:0% +crazy here so okay consider okay I think +most of you cut this point beta naught + + align:start position:0% +most of you cut this point beta naught + + + align:start position:0% +most of you cut this point beta naught +equal to Y is now nice something is pro + + align:start position:0% +equal to Y is now nice something is pro + + + align:start position:0% +equal to Y is now nice something is pro +at the edge of the universe so I don't + + align:start position:0% +at the edge of the universe so I don't + + + align:start position:0% +at the edge of the universe so I don't +like that therefore I consider only the + + align:start position:0% +like that therefore I consider only the + + + align:start position:0% +like that therefore I consider only the +case which you have absolute value beta + + align:start position:0% +case which you have absolute value beta + + + align:start position:0% +case which you have absolute value beta +equal to 1 and then we say okay you can + + align:start position:0% +equal to 1 and then we say okay you can + + + align:start position:0% +equal to 1 and then we say okay you can +be plus 1 and minus 1 but that's + + align:start position:0% +be plus 1 and minus 1 but that's + + + align:start position:0% +be plus 1 and minus 1 but that's +actually not the whole story right you + + align:start position:0% +actually not the whole story right you + + + align:start position:0% +actually not the whole story right you +can have in general beta equal to + + align:start position:0% +can have in general beta equal to + + + align:start position:0% +can have in general beta equal to +exponential I some number all right + + align:start position:0% +exponential I some number all right + + + align:start position:0% +exponential I some number all right +sounds real number okay and and I write + + align:start position:0% +sounds real number okay and and I write + + + align:start position:0% +sounds real number okay and and I write +here a very fancy expression beta equal + + align:start position:0% +here a very fancy expression beta equal + + + align:start position:0% +here a very fancy expression beta equal +to exponential I K a why i ka it's a + + align:start position:0% +to exponential I K a why i ka it's a + + + align:start position:0% +to exponential I K a why i ka it's a +very good question right what is a I + + align:start position:0% +very good question right what is a I + + + align:start position:0% +very good question right what is a I +think most of us you already forgot what + + align:start position:0% +think most of us you already forgot what + + + align:start position:0% +think most of us you already forgot what +is a a is actually the natural length of + + align:start position:0% +is a a is actually the natural length of + + + align:start position:0% +is a a is actually the natural length of +the spring okay so I was going to pass + + align:start position:0% +the spring okay so I was going to pass + + + align:start position:0% +the spring okay so I was going to pass +because I would like to get to a break + + align:start position:0% +because I would like to get to a break + + + align:start position:0% +because I would like to get to a break +to hear your questions so what is a is + + align:start position:0% +to hear your questions so what is a is + + + align:start position:0% +to hear your questions so what is a is +the natural length okay and the K what + + align:start position:0% +the natural length okay and the K what + + + align:start position:0% +the natural length okay and the K what +is K later you will figure that out + + align:start position:0% +is K later you will figure that out + + + align:start position:0% +is K later you will figure that out +you'll find that HK is wave number okay + + align:start position:0% +you'll find that HK is wave number okay + + + align:start position:0% +you'll find that HK is wave number okay +so that is actually much more meaningful + + align:start position:0% +so that is actually much more meaningful + + + align:start position:0% +so that is actually much more meaningful +now right after the explanation so you + + align:start position:0% +now right after the explanation so you + + + align:start position:0% +now right after the explanation so you +can see that beta is equal to + + align:start position:0% +can see that beta is equal to + + + align:start position:0% +can see that beta is equal to +exponential ice on number and I call it + + align:start position:0% +exponential ice on number and I call it + + + align:start position:0% +exponential ice on number and I call it +ka a pencil name of this number and it + + align:start position:0% +ka a pencil name of this number and it + + + align:start position:0% +ka a pencil name of this number and it +has some physical meaning okay another + + align:start position:0% +has some physical meaning okay another + + + align:start position:0% +has some physical meaning okay another +thing which is interesting is that + + align:start position:0% +thing which is interesting is that + + + align:start position:0% +thing which is interesting is that +if I plug in beta equal to a poor beta + + align:start position:0% +if I plug in beta equal to a poor beta + + + align:start position:0% +if I plug in beta equal to a poor beta +equal to 1 over a ok into the same + + align:start position:0% +equal to 1 over a ok into the same + + + align:start position:0% +equal to 1 over a ok into the same +expression ok if I practice either beta + + align:start position:0% +expression ok if I practice either beta + + + align:start position:0% +expression ok if I practice either beta +a or equal over beta equal to 1 moreover + + align:start position:0% +a or equal over beta equal to 1 moreover + + + align:start position:0% +a or equal over beta equal to 1 moreover +a to this expression I'm going to get + + align:start position:0% +a to this expression I'm going to get + + + align:start position:0% +a to this expression I'm going to get +exactly the same Omega so that means ok + + align:start position:0% +exactly the same Omega so that means ok + + + align:start position:0% +exactly the same Omega so that means ok +both of them will be both value will be + + align:start position:0% +both of them will be both value will be + + + align:start position:0% +both of them will be both value will be +oscillating at the same frequency okay + + align:start position:0% +oscillating at the same frequency okay + + + align:start position:0% +oscillating at the same frequency okay +so if you choose beta equal to a choose + + align:start position:0% +so if you choose beta equal to a choose + + + align:start position:0% +so if you choose beta equal to a choose +a beta equal to mine 1 minus ay they are + + align:start position:0% +a beta equal to mine 1 minus ay they are + + + align:start position:0% +a beta equal to mine 1 minus ay they are +oscillating at the same frequency what + + align:start position:0% +oscillating at the same frequency what + + + align:start position:0% +oscillating at the same frequency what +does that mean that means linear + + align:start position:0% +does that mean that means linear + + + align:start position:0% +does that mean that means linear +combination of eigenvector coming from + + align:start position:0% +combination of eigenvector coming from + + + align:start position:0% +combination of eigenvector coming from +beta equal to a and eigenvector coming + + align:start position:0% +beta equal to a and eigenvector coming + + + align:start position:0% +beta equal to a and eigenvector coming +from beta equal to 1 over a linear + + align:start position:0% +from beta equal to 1 over a linear + + + align:start position:0% +from beta equal to 1 over a linear +combination of those eigenvectors are + + align:start position:0% +combination of those eigenvectors are + + + align:start position:0% +combination of those eigenvectors are +also eigen vectors the of the n minus 1 + + align:start position:0% +also eigen vectors the of the n minus 1 + + + align:start position:0% +also eigen vectors the of the n minus 1 +K matrix okay and that's actually where + + align:start position:0% +K matrix okay and that's actually where + + + align:start position:0% +K matrix okay and that's actually where +okay those are different eigen vectors + + align:start position:0% +okay those are different eigen vectors + + + align:start position:0% +okay those are different eigen vectors +for s but the linear combination of + + align:start position:0% +for s but the linear combination of + + + align:start position:0% +for s but the linear combination of +these vectors the same are all the eigen + + align:start position:0% +these vectors the same are all the eigen + + + align:start position:0% +these vectors the same are all the eigen +vector of n minus 1 K matrix and the + + align:start position:0% +vector of n minus 1 K matrix and the + + + align:start position:0% +vector of n minus 1 K matrix and the +with the same eigen value Omega square + + align:start position:0% +with the same eigen value Omega square + + + align:start position:0% +with the same eigen value Omega square +okay so that's another thing which is + + align:start position:0% +okay so that's another thing which is + + + align:start position:0% +okay so that's another thing which is +important and finally I said that there + + align:start position:0% +important and finally I said that there + + + align:start position:0% +important and finally I said that there +are infinite number of choice oh tape + + align:start position:0% +are infinite number of choice oh tape + + + align:start position:0% +are infinite number of choice oh tape +that's bad right because you can choose + + align:start position:0% +that's bad right because you can choose + + + align:start position:0% +that's bad right because you can choose +our little number then you get a + + align:start position:0% +our little number then you get a + + + align:start position:0% +our little number then you get a +corresponding beta then you get a + + align:start position:0% +corresponding beta then you get a + + + align:start position:0% +corresponding beta then you get a +corresponding Omega so you have infinite + + align:start position:0% +corresponding Omega so you have infinite + + + align:start position:0% +corresponding Omega so you have infinite +number of normal modes secondly if I + + align:start position:0% +number of normal modes secondly if I + + + align:start position:0% +number of normal modes secondly if I +give you okay okay if I give you a K or + + align:start position:0% +give you okay okay if I give you a K or + + + align:start position:0% +give you okay okay if I give you a K or +I can give you another value which is + + align:start position:0% +I can give you another value which is + + + align:start position:0% +I can give you another value which is +minus K okay then I will that means you + + align:start position:0% +minus K okay then I will that means you + + + align:start position:0% +minus K okay then I will that means you +will get beta and 1 over beta right + + align:start position:0% +will get beta and 1 over beta right + + + align:start position:0% +will get beta and 1 over beta right +minus K will give you 1 over beta right + + align:start position:0% +minus K will give you 1 over beta right + + + align:start position:0% +minus K will give you 1 over beta right +and the answer I mentioned before big + + align:start position:0% +and the answer I mentioned before big + + + align:start position:0% +and the answer I mentioned before big +high equal to a and beta equal to + + align:start position:0% +high equal to a and beta equal to + + + align:start position:0% +high equal to a and beta equal to +I will give you the same Omega therefore + + align:start position:0% +I will give you the same Omega therefore + + + align:start position:0% +I will give you the same Omega therefore +a linear combination of the vectors are + + align:start position:0% +a linear combination of the vectors are + + + align:start position:0% +a linear combination of the vectors are +also eigen vector of ms1 kinetics + + align:start position:0% +also eigen vector of ms1 kinetics + + + align:start position:0% +also eigen vector of ms1 kinetics +nothing to what I am doing here right so + + align:start position:0% +nothing to what I am doing here right so + + + align:start position:0% +nothing to what I am doing here right so +in order to show you a real amplitude + + align:start position:0% +in order to show you a real amplitude + + + align:start position:0% +in order to show you a real amplitude +and doing a linear combination of + + align:start position:0% +and doing a linear combination of + + + align:start position:0% +and doing a linear combination of +explanation I take a a and the + + align:start position:0% +explanation I take a a and the + + + align:start position:0% +explanation I take a a and the +explanation - I take it's just a choice + + align:start position:0% +explanation - I take it's just a choice + + + align:start position:0% +explanation - I take it's just a choice +okay of course you can say okay I choose + + align:start position:0% +okay of course you can say okay I choose + + + align:start position:0% +okay of course you can say okay I choose +price and / - then you get the cosine + + align:start position:0% +price and / - then you get the cosine + + + align:start position:0% +price and / - then you get the cosine +right but if I choose this expression + + align:start position:0% +right but if I choose this expression + + + align:start position:0% +right but if I choose this expression +then what I'm going to get is that huh + + align:start position:0% +then what I'm going to get is that huh + + + align:start position:0% +then what I'm going to get is that huh +since both of them post vectors are + + align:start position:0% +since both of them post vectors are + + + align:start position:0% +since both of them post vectors are +corresponding to the same eigenvalue + + align:start position:0% +corresponding to the same eigenvalue + + + align:start position:0% +corresponding to the same eigenvalue +Omega square therefore linear + + align:start position:0% +Omega square therefore linear + + + align:start position:0% +Omega square therefore linear +combination of them also oscillate at + + align:start position:0% +combination of them also oscillate at + + + align:start position:0% +combination of them also oscillate at +the angular frequency of Omega therefore + + align:start position:0% +the angular frequency of Omega therefore + + + align:start position:0% +the angular frequency of Omega therefore +if I calculate this and make it real + + align:start position:0% +if I calculate this and make it real + + + align:start position:0% +if I calculate this and make it real +then I found out the amplitude as a + + align:start position:0% +then I found out the amplitude as a + + + align:start position:0% +then I found out the amplitude as a +function would say essentially a + + align:start position:0% +function would say essentially a + + + align:start position:0% +function would say essentially a +sinusoidal function which is sine say K + + align:start position:0% +sinusoidal function which is sine say K + + + align:start position:0% +sinusoidal function which is sine say K +okay so what does that mean this means + + align:start position:0% +okay so what does that mean this means + + + align:start position:0% +okay so what does that mean this means +that if I plot the eight if I prod AJ as + + align:start position:0% +that if I plot the eight if I prod AJ as + + + align:start position:0% +that if I plot the eight if I prod AJ as +a function of J this is actually what I + + align:start position:0% +a function of J this is actually what I + + + align:start position:0% +a function of J this is actually what I +am going to get this is a sign so dito + + align:start position:0% +am going to get this is a sign so dito + + + align:start position:0% +am going to get this is a sign so dito +shape okay and we know that XJ is + + align:start position:0% +shape okay and we know that XJ is + + + align:start position:0% +shape okay and we know that XJ is +actually equal to eight a cosine Omega T + + align:start position:0% +actually equal to eight a cosine Omega T + + + align:start position:0% +actually equal to eight a cosine Omega T +plus Phi right Omega I can actually + + align:start position:0% +plus Phi right Omega I can actually + + + align:start position:0% +plus Phi right Omega I can actually +evaluate that right from here right just + + align:start position:0% +evaluate that right from here right just + + + align:start position:0% +evaluate that right from here right just +a reminder + + align:start position:0% +a reminder + + + align:start position:0% +a reminder +and what we are going to get is when + + align:start position:0% +and what we are going to get is when + + + align:start position:0% +and what we are going to get is when +this system is in normal mode okay + + align:start position:0% +this system is in normal mode okay + + + align:start position:0% +this system is in normal mode okay +actually this is this system is still a + + align:start position:0% +actually this is this system is still a + + + align:start position:0% +actually this is this system is still a +discrete system so I actually would like + + align:start position:0% +discrete system so I actually would like + + + align:start position:0% +discrete system so I actually would like +to point out that as a function of H as + + align:start position:0% +to point out that as a function of H as + + + align:start position:0% +to point out that as a function of H as +a function say only discrete location + + align:start position:0% +a function say only discrete location + + + align:start position:0% +a function say only discrete location +have have mass right so you + + align:start position:0% +have have mass right so you + + + align:start position:0% +have have mass right so you +see that those are individual mess they + + align:start position:0% +see that those are individual mess they + + + align:start position:0% +see that those are individual mess they +are oscillating up and down okay and + + align:start position:0% +are oscillating up and down okay and + + + align:start position:0% +are oscillating up and down okay and +there you can see that okay since they + + align:start position:0% +there you can see that okay since they + + + align:start position:0% +there you can see that okay since they +are oscillating up and down there for + + align:start position:0% +are oscillating up and down there for + + + align:start position:0% +are oscillating up and down there for +the oscillation essentially going up and + + align:start position:0% +the oscillation essentially going up and + + + align:start position:0% +the oscillation essentially going up and +down therefore what is the what is + + align:start position:0% +down therefore what is the what is + + + align:start position:0% +down therefore what is the what is +situated normal more of this liquid in + + align:start position:0% +situated normal more of this liquid in + + + align:start position:0% +situated normal more of this liquid in +the long system the normal more are + + align:start position:0% +the long system the normal more are + + + align:start position:0% +the long system the normal more are +issued the standing waves but I actually + + align:start position:0% +issued the standing waves but I actually + + + align:start position:0% +issued the standing waves but I actually +only appear in the discrete value of T + + align:start position:0% +only appear in the discrete value of T + + + align:start position:0% +only appear in the discrete value of T +and it has a functional form of + + align:start position:0% +and it has a functional form of + + + align:start position:0% +and it has a functional form of +something like a sinusoidal shape or + + align:start position:0% +something like a sinusoidal shape or + + + align:start position:0% +something like a sinusoidal shape or +cosine okay so that's actually what we + + align:start position:0% +cosine okay so that's actually what we + + + align:start position:0% +cosine okay so that's actually what we +we learned unless you can you can see + + align:start position:0% +we learned unless you can you can see + + + align:start position:0% +we learned unless you can you can see +that from here so if I isolate is it + + align:start position:0% +that from here so if I isolate is it + + + align:start position:0% +that from here so if I isolate is it +it's unselected and pre - okay not quite + + align:start position:0% +it's unselected and pre - okay not quite + + + align:start position:0% +it's unselected and pre - okay not quite +get it yeah so you see that okay it's + + align:start position:0% +get it yeah so you see that okay it's + + + align:start position:0% +get it yeah so you see that okay it's +roughly like a standing wave with a + + align:start position:0% +roughly like a standing wave with a + + + align:start position:0% +roughly like a standing wave with a +fixed frequency okay I would like to + + align:start position:0% +fixed frequency okay I would like to + + + align:start position:0% +fixed frequency okay I would like to +discuss with you as really interesting + + align:start position:0% +discuss with you as really interesting + + + align:start position:0% +discuss with you as really interesting +selection so if I now take a look at so + + align:start position:0% +selection so if I now take a look at so + + + align:start position:0% +selection so if I now take a look at so +we have went through a lot of mess right + + align:start position:0% +we have went through a lot of mess right + + + align:start position:0% +we have went through a lot of mess right +so now it's the time to enjoy what we + + align:start position:0% +so now it's the time to enjoy what we + + + align:start position:0% +so now it's the time to enjoy what we +have learned right so if I now take an + + align:start position:0% +have learned right so if I now take an + + + align:start position:0% +have learned right so if I now take an +extreme value consign ka okay equal to + + align:start position:0% +extreme value consign ka okay equal to + + + align:start position:0% +extreme value consign ka okay equal to +minus one okay then I am reaching the + + align:start position:0% +minus one okay then I am reaching the + + + align:start position:0% +minus one okay then I am reaching the +Maxima oscillation frequency right so if + + align:start position:0% +Maxima oscillation frequency right so if + + + align:start position:0% +Maxima oscillation frequency right so if +I choose cosine K small K a equal to + + align:start position:0% +I choose cosine K small K a equal to + + + align:start position:0% +I choose cosine K small K a equal to +minus one okay what is going to happen + + align:start position:0% +minus one okay what is going to happen + + + align:start position:0% +minus one okay what is going to happen +is like this this is as a function + + align:start position:0% +is like this this is as a function + + + align:start position:0% +is like this this is as a function +though say byproduct AJ as a function + + align:start position:0% +though say byproduct AJ as a function + + + align:start position:0% +though say byproduct AJ as a function +say what you are going to get is 19 like + + align:start position:0% +say what you are going to get is 19 like + + + align:start position:0% +say what you are going to get is 19 like +this those are actually the amplitude of + + align:start position:0% +this those are actually the amplitude of + + + align:start position:0% +this those are actually the amplitude of +individual mass so you can see that if + + align:start position:0% +individual mass so you can see that if + + + align:start position:0% +individual mass so you can see that if +cosine ka is equal to minus 1 Omega + + align:start position:0% +cosine ka is equal to minus 1 Omega + + + align:start position:0% +cosine ka is equal to minus 1 Omega +square + + align:start position:0% +square + + + align:start position:0% +square +based on that expression 1 minus minus 1 + + align:start position:0% +based on that expression 1 minus minus 1 + + + align:start position:0% +based on that expression 1 minus minus 1 +you get 2 therefore you get Omega square + + align:start position:0% +you get 2 therefore you get Omega square + + + align:start position:0% +you get 2 therefore you get Omega square +equal to 4 Omega 0 square ok and if you + + align:start position:0% +equal to 4 Omega 0 square ok and if you + + + align:start position:0% +equal to 4 Omega 0 square ok and if you +prat the AJ as a functional J that is + + align:start position:0% +prat the AJ as a functional J that is + + + align:start position:0% +prat the AJ as a functional J that is +actually what going you are going to get + + align:start position:0% +actually what going you are going to get + + + align:start position:0% +actually what going you are going to get +you actually have Maxima stretch to the + + align:start position:0% +you actually have Maxima stretch to the + + + align:start position:0% +you actually have Maxima stretch to the +system right you can see that it's + + align:start position:0% +system right you can see that it's + + + align:start position:0% +system right you can see that it's +actually positive negative positive + + align:start position:0% +actually positive negative positive + + + align:start position:0% +actually positive negative positive +negative positive negative that will + + align:start position:0% +negative positive negative that will + + + align:start position:0% +negative positive negative that will +reach the maximum speed of the + + align:start position:0% +reach the maximum speed of the + + + align:start position:0% +reach the maximum speed of the +oscillation and of course we cannot demo + + align:start position:0% +oscillation and of course we cannot demo + + + align:start position:0% +oscillation and of course we cannot demo +we cannot demo maximum Pony number + + align:start position:0% +we cannot demo maximum Pony number + + + align:start position:0% +we cannot demo maximum Pony number +oscillator but of course I can't demo a + + align:start position:0% +oscillator but of course I can't demo a + + + align:start position:0% +oscillator but of course I can't demo a +system with ten oscillators so you can + + align:start position:0% +system with ten oscillators so you can + + + align:start position:0% +system with ten oscillators so you can +see that now I maximize the amplitude of + + align:start position:0% +see that now I maximize the amplitude of + + + align:start position:0% +see that now I maximize the amplitude of +the highest frequency normal more and + + align:start position:0% +the highest frequency normal more and + + + align:start position:0% +the highest frequency normal more and +then I let go and you see that this is + + align:start position:0% +then I let go and you see that this is + + + align:start position:0% +then I let go and you see that this is +actually exactly what is going to happen + + align:start position:0% +actually exactly what is going to happen + + + align:start position:0% +actually exactly what is going to happen +when I have cosine ka equal to minus 1 + + align:start position:0% +when I have cosine ka equal to minus 1 + + + align:start position:0% +when I have cosine ka equal to minus 1 +then the the the wetlands is very small + + align:start position:0% +then the the the wetlands is very small + + + align:start position:0% +then the the the wetlands is very small +and you actually reach the maximum speed + + align:start position:0% +and you actually reach the maximum speed + + + align:start position:0% +and you actually reach the maximum speed +makes my speed is actually to be + + align:start position:0% +makes my speed is actually to be + + + align:start position:0% +makes my speed is actually to be +compared with for example a lower + + align:start position:0% +compared with for example a lower + + + align:start position:0% +compared with for example a lower +frequency mode like this one right this + + align:start position:0% +frequency mode like this one right this + + + align:start position:0% +frequency mode like this one right this +is actually oscillating at much lower + + align:start position:0% +is actually oscillating at much lower + + + align:start position:0% +is actually oscillating at much lower +frequency and there you can ask okay + + align:start position:0% +frequency and there you can ask okay + + + align:start position:0% +frequency and there you can ask okay +does that make sense if I have this + + align:start position:0% +does that make sense if I have this + + + align:start position:0% +does that make sense if I have this +really really zigzag shape why this + + align:start position:0% +really really zigzag shape why this + + + align:start position:0% +really really zigzag shape why this +system should be oscillating at the + + align:start position:0% +system should be oscillating at the + + + align:start position:0% +system should be oscillating at the +highest possible frequency why is that + + align:start position:0% +highest possible frequency why is that + + + align:start position:0% +highest possible frequency why is that +you also make sense right if you have + + align:start position:0% +you also make sense right if you have + + + align:start position:0% +you also make sense right if you have +that set up then you are stretching this + + align:start position:0% +that set up then you are stretching this + + + align:start position:0% +that set up then you are stretching this +system to the maximum possible amount + + align:start position:0% +system to the maximum possible amount + + + align:start position:0% +system to the maximum possible amount +right so so actually now the louder the + + align:start position:0% +right so so actually now the louder the + + + align:start position:0% +right so so actually now the louder the +spring looks like this stretching is + + align:start position:0% +spring looks like this stretching is + + + align:start position:0% +spring looks like this stretching is +really hard + + align:start position:0% +really hard + + + align:start position:0% +really hard +and therefore the restoring force is + + align:start position:0% +and therefore the restoring force is + + + align:start position:0% +and therefore the restoring force is +going to be large therefore you get high + + align:start position:0% +going to be large therefore you get high + + + align:start position:0% +going to be large therefore you get high +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +okay okay so I hope you actually enjoy + + align:start position:0% +okay okay so I hope you actually enjoy + + + align:start position:0% +okay okay so I hope you actually enjoy +the lecture today is a lot of + + align:start position:0% +the lecture today is a lot of + + + align:start position:0% +the lecture today is a lot of +mathematics but what we have learned is + + align:start position:0% +mathematics but what we have learned is + + + align:start position:0% +mathematics but what we have learned is +really a lot we learned how to issue the + + align:start position:0% +really a lot we learned how to issue the + + + align:start position:0% +really a lot we learned how to issue the +described system how to actually solve a + + align:start position:0% +described system how to actually solve a + + + align:start position:0% +described system how to actually solve a +system without HD touching the MS 1k + + align:start position:0% +system without HD touching the MS 1k + + + align:start position:0% +system without HD touching the MS 1k +metrics we can actually already get the + + align:start position:0% +metrics we can actually already get the + + + align:start position:0% +metrics we can actually already get the +eigenvectors and using n minus 1 k + + align:start position:0% +eigenvectors and using n minus 1 k + + + align:start position:0% +eigenvectors and using n minus 1 k +matrix we can actually evaluate Omega as + + align:start position:0% +matrix we can actually evaluate Omega as + + + align:start position:0% +matrix we can actually evaluate Omega as +a function of the input parameter from s + + align:start position:0% +a function of the input parameter from s + + + align:start position:0% +a function of the input parameter from s +I can value and the next lectures we are + + align:start position:0% +I can value and the next lectures we are + + + align:start position:0% +I can value and the next lectures we are +going to discuss more examples and make + + align:start position:0% +going to discuss more examples and make + + + align:start position:0% +going to discuss more examples and make +the whole system continues thank you + + align:start position:0% +the whole system continues thank you + + + align:start position:0% +the whole system continues thank you +very much if you have any more questions + + align:start position:0% +very much if you have any more questions + + + align:start position:0% +very much if you have any more questions +I'll be very happy to answer your + + align:start position:0% +I'll be very happy to answer your + + + align:start position:0% +I'll be very happy to answer your +questions + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/b9X0osuciZI.txt b/b9X0osuciZI.txt new file mode 100644 index 0000000000000000000000000000000000000000..379061035739bbf594e7cb96c75c52bf9eb3bf59 --- /dev/null +++ b/b9X0osuciZI.txt @@ -0,0 +1,9997 @@ +align:start position:0% + +so we're we're very privileged to have + + align:start position:0% +so we're we're very privileged to have + + + align:start position:0% +so we're we're very privileged to have +people who flown from as far away in the + + align:start position:0% +people who flown from as far away in the + + + align:start position:0% +people who flown from as far away in the +world as you can get from here to here + + align:start position:0% +world as you can get from here to here + + + align:start position:0% +world as you can get from here to here +to be with us + + align:start position:0% +to be with us + + + align:start position:0% +to be with us +today and uh I'm going to load the the + + align:start position:0% +today and uh I'm going to load the the + + + align:start position:0% +today and uh I'm going to load the the +latest version of the + + align:start position:0% +latest version of the + + + align:start position:0% +latest version of the +presentation + + align:start position:0% +presentation + + + align:start position:0% +presentation +um Dr Dr Zang will be our first Speaker + + align:start position:0% +um Dr Dr Zang will be our first Speaker + + + align:start position:0% +um Dr Dr Zang will be our first Speaker +he is professor and director of the + + align:start position:0% +he is professor and director of the + + + align:start position:0% +he is professor and director of the +Department of high technology + + align:start position:0% +Department of high technology + + + align:start position:0% +Department of high technology +development and industrialization at the + + align:start position:0% +development and industrialization at the + + + align:start position:0% +development and industrialization at the +ministry of Science and Technology in uh + + align:start position:0% +ministry of Science and Technology in uh + + + align:start position:0% +ministry of Science and Technology in uh +in in China + + align:start position:0% +in in China + + + align:start position:0% +in in China +uh and is one of the lead Regulators for + + align:start position:0% +uh and is one of the lead Regulators for + + + align:start position:0% +uh and is one of the lead Regulators for +RFID who we've heard here throughout two + + align:start position:0% +RFID who we've heard here throughout two + + + align:start position:0% +RFID who we've heard here throughout two +days from in many cases from companies + + align:start position:0% +days from in many cases from companies + + + align:start position:0% +days from in many cases from companies +looking at how do we how do we integrate + + align:start position:0% +looking at how do we how do we integrate + + + align:start position:0% +looking at how do we how do we integrate +RFID what do we want to do with RFID and + + align:start position:0% +RFID what do we want to do with RFID and + + + align:start position:0% +RFID what do we want to do with RFID and +our companies and so he's he's got an + + align:start position:0% +our companies and so he's he's got an + + + align:start position:0% +our companies and so he's he's got an +even larger Beast to to wrestle with so + + align:start position:0% +even larger Beast to to wrestle with so + + + align:start position:0% +even larger Beast to to wrestle with so +we're very privileged to have him with + + align:start position:0% +we're very privileged to have him with + + + align:start position:0% +we're very privileged to have him with +us + + align:start position:0% + + + + align:start position:0% + +does anybody know the password on this + + align:start position:0% + + + + align:start position:0% + +machine + + align:start position:0% + + + + align:start position:0% + +password thank you + + align:start position:0% + + + + align:start position:0% + +presentation in MIT + + align:start position:0% + + + + align:start position:0% + +yes this is New Vision + + align:start position:0% + + + + align:start position:0% + +thank + + align:start position:0% + + + + align:start position:0% + +you yeah I would like to take take this + + align:start position:0% +you yeah I would like to take take this + + + align:start position:0% +you yeah I would like to take take this +opportunity to say several words for for + + align:start position:0% +opportunity to say several words for for + + + align:start position:0% +opportunity to say several words for for +IID in China so I think a lot of people + + align:start position:0% +IID in China so I think a lot of people + + + align:start position:0% +IID in China so I think a lot of people +um pay more attention to um our our + + align:start position:0% +um pay more attention to um our our + + + align:start position:0% +um pay more attention to um our our +country how to use + + align:start position:0% +country how to use + + + align:start position:0% +country how to use +RFID so I think this is uh several + + align:start position:0% +RFID so I think this is uh several + + + align:start position:0% +RFID so I think this is uh several +reasion the one is the uh the China is + + align:start position:0% +reasion the one is the uh the China is + + + align:start position:0% +reasion the one is the uh the China is +the largest population in the world + + align:start position:0% +the largest population in the world + + + align:start position:0% +the largest population in the world +so + + align:start position:0% +so + + + align:start position:0% +so +also y + + align:start position:0% +also y + + + align:start position:0% +also y +maybe this is an old + + align:start position:0% +maybe this is an old + + + align:start position:0% +maybe this is an old +Vision this old Vision not not + + align:start position:0% +Vision this old Vision not not + + + align:start position:0% +Vision this old Vision not not +new oh this is the old version okay we + + align:start position:0% +new oh this is the old version okay we + + + align:start position:0% +new oh this is the old version okay we +have a new + + align:start position:0% +have a new + + + align:start position:0% +have a new +version so I + + align:start position:0% +version so I + + + align:start position:0% +version so I +think okay + + align:start position:0% + + + + align:start position:0% + +just open it just open + + align:start position:0% +just open it just open + + + align:start position:0% +just open it just open +it just open + + align:start position:0% +it just open + + + align:start position:0% +it just open +it yeah just use + + align:start position:0% + + + + align:start position:0% + +this yeah I at first I want to to + + align:start position:0% +this yeah I at first I want to to + + + align:start position:0% +this yeah I at first I want to to +introduce some the uh so sever words for + + align:start position:0% +introduce some the uh so sever words for + + + align:start position:0% +introduce some the uh so sever words for +our + + align:start position:0% +our + + + align:start position:0% +our +ministry our ministry is science and + + align:start position:0% +ministry our ministry is science and + + + align:start position:0% +ministry our ministry is science and +technology Ministry and they focus on + + align:start position:0% +technology Ministry and they focus on + + + align:start position:0% +technology Ministry and they focus on +the research and uh set forth and the + + align:start position:0% +the research and uh set forth and the + + + align:start position:0% +the research and uh set forth and the +micro strategic for Science and + + align:start position:0% +micro strategic for Science and + + + align:start position:0% +micro strategic for Science and +Technology development as well as the uh + + align:start position:0% +Technology development as well as the uh + + + align:start position:0% +Technology development as well as the uh +Gathering uh policies and uh uh + + align:start position:0% +Gathering uh policies and uh uh + + + align:start position:0% +Gathering uh policies and uh uh +regulations for Science and Technology + + align:start position:0% +regulations for Science and Technology + + + align:start position:0% +regulations for Science and Technology +and also to the uh conduct research on + + align:start position:0% +and also to the uh conduct research on + + + align:start position:0% +and also to the uh conduct research on +key issue Rel related to the uh um + + align:start position:0% +key issue Rel related to the uh um + + + align:start position:0% +key issue Rel related to the uh um +promotion of Economic and Society + + align:start position:0% +promotion of Economic and Society + + + align:start position:0% +promotion of Economic and Society +development of by science and + + align:start position:0% +development of by science and + + + align:start position:0% +development of by science and +technology also to research and + + align:start position:0% +technology also to research and + + + align:start position:0% +technology also to research and +uh determined to major development and + + align:start position:0% +uh determined to major development and + + + align:start position:0% +uh determined to major development and +uh PR priority areas for Science and + + align:start position:0% +uh PR priority areas for Science and + + + align:start position:0% +uh PR priority areas for Science and +Technology development and also to + + align:start position:0% +Technology development and also to + + + align:start position:0% +Technology development and also to +promote the uh build + + align:start position:0% +promote the uh build + + + align:start position:0% +promote the uh build +of the uh National Sense Technology + + align:start position:0% +of the uh National Sense Technology + + + align:start position:0% +of the uh National Sense Technology +Innovation System and uh improve the + + align:start position:0% +Innovation System and uh improve the + + + align:start position:0% +Innovation System and uh improve the +national sense and Technology Innovation + + align:start position:0% + + + + align:start position:0% + +capacity so I think uh lot of people um + + align:start position:0% +capacity so I think uh lot of people um + + + align:start position:0% +capacity so I think uh lot of people um +look at the uh China how to develop RFID + + align:start position:0% +look at the uh China how to develop RFID + + + align:start position:0% +look at the uh China how to develop RFID +the application because this is the + + align:start position:0% +the application because this is the + + + align:start position:0% +the application because this is the +several region the first reason is the + + align:start position:0% +several region the first reason is the + + + align:start position:0% +several region the first reason is the +the largest population and the + + align:start position:0% +the largest population and the + + + align:start position:0% +the largest population and the +larg + + align:start position:0% +larg + + + align:start position:0% +larg +um consumer Market in the in the world + + align:start position:0% +um consumer Market in the in the world + + + align:start position:0% +um consumer Market in the in the world +so the second reason is the + + align:start position:0% +so the second reason is the + + + align:start position:0% +so the second reason is the +manufacturing center of the world and uh + + align:start position:0% +manufacturing center of the world and uh + + + align:start position:0% +manufacturing center of the world and uh +also related for the uh + + align:start position:0% +also related for the uh + + + align:start position:0% +also related for the uh +big the company in the world + + align:start position:0% +big the company in the world + + + align:start position:0% +big the company in the world +so um how to use the RFID also not only + + align:start position:0% +so um how to use the RFID also not only + + + align:start position:0% +so um how to use the RFID also not only +um related with the Chinese company also + + align:start position:0% +um related with the Chinese company also + + + align:start position:0% +um related with the Chinese company also +for the uh uh foreign big company and + + align:start position:0% +for the uh uh foreign big company and + + + align:start position:0% +for the uh uh foreign big company and +also it applications is just at the + + align:start position:0% +also it applications is just at the + + + align:start position:0% +also it applications is just at the +beginning with much more um potential to + + align:start position:0% +beginning with much more um potential to + + + align:start position:0% +beginning with much more um potential to +be + + align:start position:0% + + + + align:start position:0% + +explored and this picture is the rid + + align:start position:0% +explored and this picture is the rid + + + align:start position:0% +explored and this picture is the rid +Market in + + align:start position:0% +Market in + + + align:start position:0% +Market in +2004 and uh rid technology and + + align:start position:0% +2004 and uh rid technology and + + + align:start position:0% +2004 and uh rid technology and +applications have got the promot + + align:start position:0% +applications have got the promot + + + align:start position:0% +applications have got the promot +development in the last two years in + + align:start position:0% +development in the last two years in + + + align:start position:0% +development in the last two years in +China and uh recently all all of the uh + + align:start position:0% +China and uh recently all all of the uh + + + align:start position:0% +China and uh recently all all of the uh +everybody have a new ID use the r + + align:start position:0% + + + + align:start position:0% + +ID so this total the market is about uh + + align:start position:0% +ID so this total the market is about uh + + + align:start position:0% +ID so this total the market is about uh +uh$ 150 million + + align:start position:0% + + + + align:start position:0% + +us and the potential application in + + align:start position:0% +us and the potential application in + + + align:start position:0% +us and the potential application in +China Market uh I think maybe in the + + align:start position:0% +China Market uh I think maybe in the + + + align:start position:0% +China Market uh I think maybe in the +this several area the one is the uh + + align:start position:0% +this several area the one is the uh + + + align:start position:0% +this several area the one is the uh +security and the safety + + align:start position:0% +security and the safety + + + align:start position:0% +security and the safety +and also it's very important area is + + align:start position:0% +and also it's very important area is + + + align:start position:0% +and also it's very important area is +uh uh Artic uh counterfeit for example + + align:start position:0% +uh uh Artic uh counterfeit for example + + + align:start position:0% +uh uh Artic uh counterfeit for example +some the uh health and Health Care + + align:start position:0% +some the uh health and Health Care + + + align:start position:0% +some the uh health and Health Care +tobacco and the + + align:start position:0% +tobacco and the + + + align:start position:0% +tobacco and the +liak and also we application the RFID + + align:start position:0% +liak and also we application the RFID + + + align:start position:0% +liak and also we application the RFID +maybe in their + + align:start position:0% +maybe in their + + + align:start position:0% +maybe in their +Logistics and also for the manufact uh + + align:start position:0% +Logistics and also for the manufact uh + + + align:start position:0% +Logistics and also for the manufact uh +manufacturing Process Management + + align:start position:0% +manufacturing Process Management + + + align:start position:0% +manufacturing Process Management +and also for the E tiet + + align:start position:0% +and also for the E tiet + + + align:start position:0% +and also for the E tiet +system and such as the uh Subway ticket + + align:start position:0% +system and such as the uh Subway ticket + + + align:start position:0% +system and such as the uh Subway ticket +we already use it in Shanghai and also + + align:start position:0% +we already use it in Shanghai and also + + + align:start position:0% +we already use it in Shanghai and also +we want use it in olypic games in the + + align:start position:0% +we want use it in olypic games in the + + + align:start position:0% +we want use it in olypic games in the +2008 and uh shangai W the uh + + align:start position:0% +2008 and uh shangai W the uh + + + align:start position:0% +2008 and uh shangai W the uh +Exposition and in + + align:start position:0% +Exposition and in + + + align:start position:0% +Exposition and in +2010 and also we developed this uh rid + + align:start position:0% +2010 and also we developed this uh rid + + + align:start position:0% +2010 and also we developed this uh rid +using the vehicle man uh management + + align:start position:0% +using the vehicle man uh management + + + align:start position:0% +using the vehicle man uh management +system when the uh vehicle pass the gate + + align:start position:0% +system when the uh vehicle pass the gate + + + align:start position:0% +system when the uh vehicle pass the gate +they can show you the picture and the + + align:start position:0% +they can show you the picture and the + + + align:start position:0% +they can show you the picture and the +color and you can find it and also um we + + align:start position:0% +color and you can find it and also um we + + + align:start position:0% +color and you can find it and also um we +use it in the supply chair + + align:start position:0% + + + + align:start position:0% + +management and this is the + + align:start position:0% +management and this is the + + + align:start position:0% +management and this is the +uh um har use the uh + + align:start position:0% +uh um har use the uh + + + align:start position:0% +uh um har use the uh +RFID so this is uh um container tricking + + align:start position:0% +RFID so this is uh um container tricking + + + align:start position:0% +RFID so this is uh um container tricking +this is located in + + align:start position:0% +this is located in + + + align:start position:0% +this is located in +Shanghai and uh recently we we used the + + align:start position:0% +Shanghai and uh recently we we used the + + + align:start position:0% +Shanghai and uh recently we we used the +RFID the tag in Shanghai International + + align:start position:0% +RFID the tag in Shanghai International + + + align:start position:0% +RFID the tag in Shanghai International +Port Harbor and uh they connect with the + + align:start position:0% +Port Harbor and uh they connect with the + + + align:start position:0% +Port Harbor and uh they connect with the +uh another very important Harbor in y s + + align:start position:0% +uh another very important Harbor in y s + + + align:start position:0% +uh another very important Harbor in y s +Province after now they already shipped + + align:start position:0% +Province after now they already shipped + + + align:start position:0% +Province after now they already shipped +more than 7,000 containers just still to + + align:start position:0% +more than 7,000 containers just still to + + + align:start position:0% +more than 7,000 containers just still to +the demo + + align:start position:0% + + + + align:start position:0% + +also we are we already use it in the uh + + align:start position:0% +also we are we already use it in the uh + + + align:start position:0% +also we are we already use it in the uh +fairworks + + align:start position:0% +fairworks + + + align:start position:0% +fairworks +management because it's dangerous always + + align:start position:0% +management because it's dangerous always + + + align:start position:0% +management because it's dangerous always +take place from the + + align:start position:0% +take place from the + + + align:start position:0% +take place from the +accident and also we used the rid in the + + align:start position:0% +accident and also we used the rid in the + + + align:start position:0% +accident and also we used the rid in the +dangerous case + + align:start position:0% +dangerous case + + + align:start position:0% +dangerous case +managements so we put the uh tag in the + + align:start position:0% +managements so we put the uh tag in the + + + align:start position:0% +managements so we put the uh tag in the +the + + align:start position:0% +the + + + align:start position:0% +the +tanks and also we we used our + + align:start position:0% +tanks and also we we used our + + + align:start position:0% +tanks and also we we used our +to management animal and the + + align:start position:0% +to management animal and the + + + align:start position:0% +to management animal and the +foods and also in sh we have put the tag + + align:start position:0% +foods and also in sh we have put the tag + + + align:start position:0% +foods and also in sh we have put the tag +in in the air of the dog so we can find + + align:start position:0% +in in the air of the dog so we can find + + + align:start position:0% +in in the air of the dog so we can find +it and they put some um illegal or only + + align:start position:0% + + + + align:start position:0% + +ille and also we use it in the co Manor + + align:start position:0% +ille and also we use it in the co Manor + + + align:start position:0% +ille and also we use it in the co Manor +location and the + + align:start position:0% +location and the + + + align:start position:0% +location and the +tricking so also in China and frequency + + align:start position:0% +tricking so also in China and frequency + + + align:start position:0% +tricking so also in China and frequency +to take a place some the accident in a + + align:start position:0% +to take a place some the accident in a + + + align:start position:0% +to take a place some the accident in a +manner so how to catch time to save the + + align:start position:0% +manner so how to catch time to save the + + + align:start position:0% +manner so how to catch time to save the +life this is very + + align:start position:0% +life this is very + + + align:start position:0% +life this is very +important so I think in the I just uh + + align:start position:0% +important so I think in the I just uh + + + align:start position:0% +important so I think in the I just uh +look at the TV North Kina also take + + align:start position:0% +look at the TV North Kina also take + + + align:start position:0% +look at the TV North Kina also take +place some the accident so I think this + + align:start position:0% +place some the accident so I think this + + + align:start position:0% +place some the accident so I think this +is uh very popular in the near future + + align:start position:0% +is uh very popular in the near future + + + align:start position:0% +is uh very popular in the near future +how to c application this uh technology + + align:start position:0% +how to c application this uh technology + + + align:start position:0% +how to c application this uh technology +to save the SE life + + align:start position:0% +to save the SE life + + + align:start position:0% +to save the SE life +and we already give them the pilot + + align:start position:0% +and we already give them the pilot + + + align:start position:0% +and we already give them the pilot +project for the post office this a China + + align:start position:0% +project for the post office this a China + + + align:start position:0% +project for the post office this a China +p and post office use the uh the tag put + + align:start position:0% +p and post office use the uh the tag put + + + align:start position:0% +p and post office use the uh the tag put +it into the uh mirr bags in uh for the + + align:start position:0% +it into the uh mirr bags in uh for the + + + align:start position:0% +it into the uh mirr bags in uh for the +EMS + + align:start position:0% +EMS + + + align:start position:0% +EMS +the this is a Shanghai use the uh the PO + + align:start position:0% +the this is a Shanghai use the uh the PO + + + align:start position:0% +the this is a Shanghai use the uh the PO +post office use the + + align:start position:0% + + + + align:start position:0% + +RFID and this is a Manufacturing Process + + align:start position:0% +RFID and this is a Manufacturing Process + + + align:start position:0% +RFID and this is a Manufacturing Process +Management and for + + align:start position:0% +Management and for + + + align:start position:0% +Management and for +the + + align:start position:0% + + + + align:start position:0% + +the products land to manage the + + align:start position:0% +the products land to manage the + + + align:start position:0% +the products land to manage the +uh each and products + + align:start position:0% +uh each and products + + + align:start position:0% +uh each and products +Point can control the the product + + align:start position:0% + + + + align:start position:0% + +quality this is a China the FID industry + + align:start position:0% +quality this is a China the FID industry + + + align:start position:0% +quality this is a China the FID industry +policy well of the most important area + + align:start position:0% +policy well of the most important area + + + align:start position:0% +policy well of the most important area +in China the national development + + align:start position:0% +in China the national development + + + align:start position:0% +in China the national development +planning and on the high tech area for + + align:start position:0% +planning and on the high tech area for + + + align:start position:0% +planning and on the high tech area for +the coming F + + align:start position:0% +the coming F + + + align:start position:0% +the coming F +years so this is a a big program program + + align:start position:0% +years so this is a a big program program + + + align:start position:0% +years so this is a a big program program +and also make China RFID technology + + align:start position:0% +and also make China RFID technology + + + align:start position:0% +and also make China RFID technology +strategy and policy funding RFID + + align:start position:0% +strategy and policy funding RFID + + + align:start position:0% +strategy and policy funding RFID +application to promote promote the RFID + + align:start position:0% +application to promote promote the RFID + + + align:start position:0% +application to promote promote the RFID +technology and Industry development + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +uh our ministry and also con uh + + align:start position:0% +uh our ministry and also con uh + + + align:start position:0% +uh our ministry and also con uh +constitute constitute the China IID + + align:start position:0% +constitute constitute the China IID + + + align:start position:0% +constitute constitute the China IID +technology with paper work together with + + align:start position:0% +technology with paper work together with + + + align:start position:0% +technology with paper work together with +the other 14 Ministry or departments + + align:start position:0% +the other 14 Ministry or departments + + + align:start position:0% +the other 14 Ministry or departments +because you know this kind of + + align:start position:0% +because you know this kind of + + + align:start position:0% +because you know this kind of +application related with the different + + align:start position:0% +application related with the different + + + align:start position:0% +application related with the different +Ministry or different department so we + + align:start position:0% +Ministry or different department so we + + + align:start position:0% +Ministry or different department so we +must work with them together to make the + + align:start position:0% +must work with them together to make the + + + align:start position:0% +must work with them together to make the +policy and make some + + align:start position:0% +policy and make some + + + align:start position:0% +policy and make some +standard also research and establish the + + align:start position:0% +standard also research and establish the + + + align:start position:0% +standard also research and establish the +architecture for the China RFID uh + + align:start position:0% +architecture for the China RFID uh + + + align:start position:0% +architecture for the China RFID uh +standard which connect with the + + align:start position:0% +standard which connect with the + + + align:start position:0% +standard which connect with the +international standard and the + + align:start position:0% +international standard and the + + + align:start position:0% +international standard and the +accommodate the China um + + align:start position:0% + + + + align:start position:0% + +surrounding and the state a spe uh + + align:start position:0% +surrounding and the state a spe uh + + + align:start position:0% +surrounding and the state a spe uh +specific rid program in National hch R&D + + align:start position:0% +specific rid program in National hch R&D + + + align:start position:0% +specific rid program in National hch R&D +program this 836 program established in + + align:start position:0% +program this 836 program established in + + + align:start position:0% +program this 836 program established in +March + + align:start position:0% +March + + + align:start position:0% +March +1986 this reviewed by the very famous + + align:start position:0% +1986 this reviewed by the very famous + + + align:start position:0% +1986 this reviewed by the very famous +leader Dana + + align:start position:0% +leader Dana + + + align:start position:0% +leader Dana +ping so to speed up the progress of RFID + + align:start position:0% +ping so to speed up the progress of RFID + + + align:start position:0% +ping so to speed up the progress of RFID +research application and + + align:start position:0% +research application and + + + align:start position:0% +research application and +industrialization and set up a RFID + + align:start position:0% +industrialization and set up a RFID + + + align:start position:0% +industrialization and set up a RFID +committee to make the national RFID + + align:start position:0% +committee to make the national RFID + + + align:start position:0% +committee to make the national RFID +research plan and the F RFID research + + align:start position:0% +research plan and the F RFID research + + + align:start position:0% +research plan and the F RFID research +and the found the rid application and + + align:start position:0% +and the found the rid application and + + + align:start position:0% +and the found the rid application and +help local government to set up IID + + align:start position:0% +help local government to set up IID + + + align:start position:0% +help local government to set up IID +research technology and Industry + + align:start position:0% +research technology and Industry + + + align:start position:0% +research technology and Industry +industrial + + align:start position:0% + + + + align:start position:0% + +Zone also um we are pay more attention + + align:start position:0% +Zone also um we are pay more attention + + + align:start position:0% +Zone also um we are pay more attention +research on + + align:start position:0% +research on + + + align:start position:0% +research on +standard I think the standard and + + align:start position:0% +standard I think the standard and + + + align:start position:0% +standard I think the standard and +can research for the + + align:start position:0% +can research for the + + + align:start position:0% +can research for the +several uh Direction the one is the + + align:start position:0% +several uh Direction the one is the + + + align:start position:0% +several uh Direction the one is the +products code coding standard and also + + align:start position:0% +products code coding standard and also + + + align:start position:0% +products code coding standard and also +for the + + align:start position:0% +for the + + + align:start position:0% +for the +RFID uh + + align:start position:0% +RFID uh + + + align:start position:0% +RFID uh +communication and pro protocol and also + + align:start position:0% +communication and pro protocol and also + + + align:start position:0% +communication and pro protocol and also +rid product standard and Equipment + + align:start position:0% +rid product standard and Equipment + + + align:start position:0% +rid product standard and Equipment +standard and also for the application + + align:start position:0% +standard and also for the application + + + align:start position:0% +standard and also for the application +standard for example if we want to use + + align:start position:0% +standard for example if we want to use + + + align:start position:0% +standard for example if we want to use +in the post office we must uh make sure + + align:start position:0% +in the post office we must uh make sure + + + align:start position:0% +in the post office we must uh make sure +and what kind of uh the in + + align:start position:0% +and what kind of uh the in + + + align:start position:0% +and what kind of uh the in +the and which the position you can put + + align:start position:0% +the and which the position you can put + + + align:start position:0% +the and which the position you can put +it put it put on and uh what the + + align:start position:0% +it put it put on and uh what the + + + align:start position:0% +it put it put on and uh what the +frequency you want to use it and also + + align:start position:0% +frequency you want to use it and also + + + align:start position:0% +frequency you want to use it and also +for the different industry area we must + + align:start position:0% +for the different industry area we must + + + align:start position:0% +for the different industry area we must +make decision what kind of frequency you + + align:start position:0% +make decision what kind of frequency you + + + align:start position:0% +make decision what kind of frequency you +can use it so for example for The Med + + align:start position:0% +can use it so for example for The Med + + + align:start position:0% +can use it so for example for The Med +pills so where you can put it in the in + + align:start position:0% +pills so where you can put it in the in + + + align:start position:0% +pills so where you can put it in the in +the the bottle + + align:start position:0% +the the bottle + + + align:start position:0% +the the bottle +so we must make a lot of applications + + align:start position:0% +so we must make a lot of applications + + + align:start position:0% +so we must make a lot of applications +Stander this is very important I think + + align:start position:0% +Stander this is very important I think + + + align:start position:0% +Stander this is very important I think +and also we establish some the testing + + align:start position:0% +and also we establish some the testing + + + align:start position:0% +and also we establish some the testing +and certification Center we are set up + + align:start position:0% +and certification Center we are set up + + + align:start position:0% +and certification Center we are set up +the national testing center on FID + + align:start position:0% +the national testing center on FID + + + align:start position:0% +the national testing center on FID +technology so one of them they will test + + align:start position:0% +technology so one of them they will test + + + align:start position:0% +technology so one of them they will test +the products performance and also we uh + + align:start position:0% +the products performance and also we uh + + + align:start position:0% +the products performance and also we uh +evaluate the RFID products and uh + + align:start position:0% +evaluate the RFID products and uh + + + align:start position:0% +evaluate the RFID products and uh +simulate application environments and + + align:start position:0% +simulate application environments and + + + align:start position:0% +simulate application environments and +uh as is the + + align:start position:0% +uh as is the + + + align:start position:0% +uh as is the +applications for example I say say that + + align:start position:0% +applications for example I say say that + + + align:start position:0% +applications for example I say say that +we useing the uh Co Manor the tricking + + align:start position:0% +we useing the uh Co Manor the tricking + + + align:start position:0% +we useing the uh Co Manor the tricking +system we may maybe we want to use the + + align:start position:0% +system we may maybe we want to use the + + + align:start position:0% +system we may maybe we want to use the +uh active + + align:start position:0% +uh active + + + align:start position:0% +uh active +Tech in the in the normal surrounding + + align:start position:0% +Tech in the in the normal surrounding + + + align:start position:0% +Tech in the in the normal surrounding +maybe they can transfer the information + + align:start position:0% +maybe they can transfer the information + + + align:start position:0% +maybe they can transfer the information +more than 100 meter but when take place + + align:start position:0% +more than 100 meter but when take place + + + align:start position:0% +more than 100 meter but when take place +the AC accident the code will fall down + + align:start position:0% +the AC accident the code will fall down + + + align:start position:0% +the AC accident the code will fall down +so in this kind of situation how long + + align:start position:0% +so in this kind of situation how long + + + align:start position:0% +so in this kind of situation how long +they can transfer the information so + + align:start position:0% +they can transfer the information so + + + align:start position:0% +they can transfer the information so +this is must the simulate in the + + align:start position:0% + + + + align:start position:0% + +labor also um there we are pay more + + align:start position:0% +labor also um there we are pay more + + + align:start position:0% +labor also um there we are pay more +attention to the + + align:start position:0% +attention to the + + + align:start position:0% +attention to the +TX we are set up the some research proog + + align:start position:0% +TX we are set up the some research proog + + + align:start position:0% +TX we are set up the some research proog +and project for example we are research + + align:start position:0% +and project for example we are research + + + align:start position:0% +and project for example we are research +the UHF chips and the + + align:start position:0% +the UHF chips and the + + + align:start position:0% +the UHF chips and the +UHF antenna design and also Tech + + align:start position:0% +UHF antenna design and also Tech + + + align:start position:0% +UHF antenna design and also Tech +integrate with the other sensor + + align:start position:0% +integrate with the other sensor + + + align:start position:0% +integrate with the other sensor +technology and also and pay more + + align:start position:0% +technology and also and pay more + + + align:start position:0% +technology and also and pay more +attention to + + align:start position:0% +attention to + + + align:start position:0% +attention to +packaging and uh in the reader we are + + align:start position:0% +packaging and uh in the reader we are + + + align:start position:0% +packaging and uh in the reader we are +also research some UHF reader and the + + align:start position:0% +also research some UHF reader and the + + + align:start position:0% +also research some UHF reader and the +UHF reader antenna design and also + + align:start position:0% +UHF reader antenna design and also + + + align:start position:0% +UHF reader antenna design and also +active IID + + align:start position:0% + + + + align:start position:0% + +technology and for the research network + + align:start position:0% +technology and for the research network + + + align:start position:0% +technology and for the research network +uh architecture and + + align:start position:0% +uh architecture and + + + align:start position:0% +uh architecture and +uh product name service system for + + align:start position:0% +uh product name service system for + + + align:start position:0% +uh product name service system for +Supply Chain + + align:start position:0% +Supply Chain + + + align:start position:0% +Supply Chain +management and also we support the uh + + align:start position:0% +management and also we support the uh + + + align:start position:0% +management and also we support the uh +planning to set up local products name + + align:start position:0% +planning to set up local products name + + + align:start position:0% +planning to set up local products name +service system on the China domestic + + align:start position:0% +service system on the China domestic + + + align:start position:0% +service system on the China domestic +supply chain + + align:start position:0% +supply chain + + + align:start position:0% +supply chain +environment which could + + align:start position:0% +environment which could + + + align:start position:0% +environment which could +map the um the + + align:start position:0% +map the um the + + + align:start position:0% +map the um the +secon the data with the other name + + align:start position:0% +secon the data with the other name + + + align:start position:0% +secon the data with the other name +system for example the O system + + align:start position:0% +system for example the O system + + + align:start position:0% +system for example the O system +so carry out the international uh + + align:start position:0% +so carry out the international uh + + + align:start position:0% +so carry out the international uh +collaboration with the all kind of the + + align:start position:0% +collaboration with the all kind of the + + + align:start position:0% +collaboration with the all kind of the +organizations such as the standard + + align:start position:0% +organizations such as the standard + + + align:start position:0% +organizations such as the standard +committee and the research and Academy + + align:start position:0% +committee and the research and Academy + + + align:start position:0% +committee and the research and Academy +also for the some big company or some + + align:start position:0% +also for the some big company or some + + + align:start position:0% +also for the some big company or some +foreign uh government so I think this we + + align:start position:0% +foreign uh government so I think this we + + + align:start position:0% +foreign uh government so I think this we +open the door to want to cooperation + + align:start position:0% +open the door to want to cooperation + + + align:start position:0% +open the door to want to cooperation +with the different partner um based + + align:start position:0% +with the different partner um based + + + align:start position:0% +with the different partner um based +their women cooperation so I think this + + align:start position:0% +their women cooperation so I think this + + + align:start position:0% +their women cooperation so I think this +is a big issue not only useful for China + + align:start position:0% +is a big issue not only useful for China + + + align:start position:0% +is a big issue not only useful for China +to develop their technology and also I + + align:start position:0% +to develop their technology and also I + + + align:start position:0% +to develop their technology and also I +think must cooperation uh with the every + + align:start position:0% +think must cooperation uh with the every + + + align:start position:0% +think must cooperation uh with the every +every organization or every country they + + align:start position:0% +every organization or every country they + + + align:start position:0% +every organization or every country they +can do more best to reduce the cost and + + align:start position:0% +can do more best to reduce the cost and + + + align:start position:0% +can do more best to reduce the cost and +also develop the Next Generation the + + align:start position:0% +also develop the Next Generation the + + + align:start position:0% +also develop the Next Generation the +technology make the the chips more cheap + + align:start position:0% +technology make the the chips more cheap + + + align:start position:0% +technology make the the chips more cheap +and also for the tax the uh also redu + + align:start position:0% +and also for the tax the uh also redu + + + align:start position:0% +and also for the tax the uh also redu +the cost so I think this is a big issue + + align:start position:0% +the cost so I think this is a big issue + + + align:start position:0% +the cost so I think this is a big issue +so we must cooperation each + + align:start position:0% +so we must cooperation each + + + align:start position:0% +so we must cooperation each +other + + align:start position:0% +other + + + align:start position:0% +other +[Applause] + + align:start position:0% + + + + align:start position:0% + +thanks thank you very much Dr Zang and + + align:start position:0% +thanks thank you very much Dr Zang and + + + align:start position:0% +thanks thank you very much Dr Zang and +now for a different perspective from + + align:start position:0% +now for a different perspective from + + + align:start position:0% +now for a different perspective from +Europe uh we're very privileged to have + + align:start position:0% +Europe uh we're very privileged to have + + + align:start position:0% +Europe uh we're very privileged to have +uh Peter F who is the DG Information + + align:start position:0% +uh Peter F who is the DG Information + + + align:start position:0% +uh Peter F who is the DG Information +Society and media Network and + + align:start position:0% +Society and media Network and + + + align:start position:0% +Society and media Network and +Communications Technologies ICT for + + align:start position:0% +Communications Technologies ICT for + + + align:start position:0% +Communications Technologies ICT for +Enterprise networking director for + + align:start position:0% +Enterprise networking director for + + + align:start position:0% +Enterprise networking director for +Europe and and is actually one of the + + align:start position:0% +Europe and and is actually one of the + + + align:start position:0% +Europe and and is actually one of the +principal funders of uh some programs + + align:start position:0% +principal funders of uh some programs + + + align:start position:0% +principal funders of uh some programs +that you've already heard about + + align:start position:0% +that you've already heard about + + + align:start position:0% +that you've already heard about +including the uh promise program that + + align:start position:0% +including the uh promise program that + + + align:start position:0% +including the uh promise program that +that was introduced yesterday thank you + + align:start position:0% +that was introduced yesterday thank you + + + align:start position:0% +that was introduced yesterday thank you +I put it + + align:start position:0% +I put it + + + align:start position:0% +I put it +here fine + + align:start position:0% +here fine + + + align:start position:0% +here fine +okay so let's find this + + align:start position:0% + + + + align:start position:0% + +just take my papers thank + + align:start position:0% + + + + align:start position:0% + +much well perfect thank you very much + + align:start position:0% +much well perfect thank you very much + + + align:start position:0% +much well perfect thank you very much +good afternoon ladies and gentlemen + + align:start position:0% +good afternoon ladies and gentlemen + + + align:start position:0% +good afternoon ladies and gentlemen +thanks a lot to Steve and and John to + + align:start position:0% +thanks a lot to Steve and and John to + + + align:start position:0% +thanks a lot to Steve and and John to +have to opportunity to talk today on + + align:start position:0% +have to opportunity to talk today on + + + align:start position:0% +have to opportunity to talk today on +behalf of the European commission it was + + align:start position:0% +behalf of the European commission it was + + + align:start position:0% +behalf of the European commission it was +quite a long journey anyhow to come over + + align:start position:0% +quite a long journey anyhow to come over + + + align:start position:0% +quite a long journey anyhow to come over +and it was for me the last the last time + + align:start position:0% +and it was for me the last the last time + + + align:start position:0% +and it was for me the last the last time +I've been States was is 26 years ago + + align:start position:0% +I've been States was is 26 years ago + + + align:start position:0% +I've been States was is 26 years ago +so and then I have been to California so + + align:start position:0% +so and then I have been to California so + + + align:start position:0% +so and then I have been to California so +it's first time to be the New England + + align:start position:0% +it's first time to be the New England + + + align:start position:0% +it's first time to be the New England +states well I would like to present you + + align:start position:0% +states well I would like to present you + + + align:start position:0% +states well I would like to present you +briefly the P European perspective from + + align:start position:0% +briefly the P European perspective from + + + align:start position:0% +briefly the P European perspective from +RFID I'm working in um public + + align:start position:0% +RFID I'm working in um public + + + align:start position:0% +RFID I'm working in um public +administration at the European + + align:start position:0% +administration at the European + + + align:start position:0% +administration at the European +commission I'm sure that you're familiar + + align:start position:0% +commission I'm sure that you're familiar + + + align:start position:0% +commission I'm sure that you're familiar +how the commission works we are + + align:start position:0% +how the commission works we are + + + align:start position:0% +how the commission works we are +supernational + + align:start position:0% +supernational + + + align:start position:0% +supernational +body and we have no Ministeries but we + + align:start position:0% +body and we have no Ministeries but we + + + align:start position:0% +body and we have no Ministeries but we +have a lot of director generals and each + + align:start position:0% +have a lot of director generals and each + + + align:start position:0% +have a lot of director generals and each +director General has a commissioner and + + align:start position:0% +director General has a commissioner and + + + align:start position:0% +director General has a commissioner and +um and + + align:start position:0% +um and + + + align:start position:0% +um and +yesterday told about the 30 models on + + align:start position:0% +yesterday told about the 30 models on + + + align:start position:0% +yesterday told about the 30 models on +pedigree this reminded me quite well of + + align:start position:0% +pedigree this reminded me quite well of + + + align:start position:0% +pedigree this reminded me quite well of +our work because we have always 25 + + align:start position:0% +our work because we have always 25 + + + align:start position:0% +our work because we have always 25 +member states and depending on the + + align:start position:0% +member states and depending on the + + + align:start position:0% +member states and depending on the +subject we have a very let me say um + + align:start position:0% +subject we have a very let me say um + + + align:start position:0% +subject we have a very let me say um +good direct power or we are more working + + align:start position:0% +good direct power or we are more working + + + align:start position:0% +good direct power or we are more working +on a basis of of being a facilitator so + + align:start position:0% +on a basis of of being a facilitator so + + + align:start position:0% +on a basis of of being a facilitator so +and for our ID I think it's uh between + + align:start position:0% +and for our ID I think it's uh between + + + align:start position:0% +and for our ID I think it's uh between +both um I'm working on Research + + align:start position:0% +both um I'm working on Research + + + align:start position:0% +both um I'm working on Research +Administration which means that + + align:start position:0% +Administration which means that + + + align:start position:0% +Administration which means that +basically Europe the European commission + + align:start position:0% +basically Europe the European commission + + + align:start position:0% +basically Europe the European commission +is not um executing aearch on its own + + align:start position:0% +is not um executing aearch on its own + + + align:start position:0% +is not um executing aearch on its own +apart from some specialized Institutes + + align:start position:0% +apart from some specialized Institutes + + + align:start position:0% +apart from some specialized Institutes +um we are always commissioning in the + + align:start position:0% +um we are always commissioning in the + + + align:start position:0% +um we are always commissioning in the +work or in the frame of some framework + + align:start position:0% +work or in the frame of some framework + + + align:start position:0% +work or in the frame of some framework +programs uh + + align:start position:0% +programs uh + + + align:start position:0% +programs uh +research and um what we try always is of + + align:start position:0% +research and um what we try always is of + + + align:start position:0% +research and um what we try always is of +course in terms of speeding up Europeans + + align:start position:0% +course in terms of speeding up Europeans + + + align:start position:0% +course in terms of speeding up Europeans +uh Europe's competence and + + align:start position:0% +uh Europe's competence and + + + align:start position:0% +uh Europe's competence and +competitiveness to facilitate the right + + align:start position:0% +competitiveness to facilitate the right + + + align:start position:0% +competitiveness to facilitate the right +research issues in the same time to + + align:start position:0% +research issues in the same time to + + + align:start position:0% +research issues in the same time to +ensure that um the the results of the + + align:start position:0% +ensure that um the the results of the + + + align:start position:0% +ensure that um the the results of the +research are going to be taken up + + align:start position:0% +research are going to be taken up + + + align:start position:0% +research are going to be taken up +afterwards and there are quite often + + align:start position:0% +afterwards and there are quite often + + + align:start position:0% +afterwards and there are quite often +Europe has some + + align:start position:0% +Europe has some + + + align:start position:0% +Europe has some +weaknesses so basically what we try to + + align:start position:0% +weaknesses so basically what we try to + + + align:start position:0% +weaknesses so basically what we try to +do as I do did yesterday and to today is + + align:start position:0% +do as I do did yesterday and to today is + + + align:start position:0% +do as I do did yesterday and to today is +to learn and to see what should we uh + + align:start position:0% +to learn and to see what should we uh + + + align:start position:0% +to learn and to see what should we uh +where should we proceed in terms of the + + align:start position:0% +where should we proceed in terms of the + + + align:start position:0% +where should we proceed in terms of the +future R RFID um + + align:start position:0% +future R RFID um + + + align:start position:0% +future R RFID um +research um so I'm Ching around about uh + + align:start position:0% +research um so I'm Ching around about uh + + + align:start position:0% +research um so I'm Ching around about uh +inter service working group we + + align:start position:0% +inter service working group we + + + align:start position:0% +inter service working group we +established last year on RFID on + + align:start position:0% +established last year on RFID on + + + align:start position:0% +established last year on RFID on +International collaboration European + + align:start position:0% +International collaboration European + + + align:start position:0% +International collaboration European +research and RFID topics of RFID + + align:start position:0% +research and RFID topics of RFID + + + align:start position:0% +research and RFID topics of RFID +discussion in Europe today and next + + align:start position:0% +discussion in Europe today and next + + + align:start position:0% +discussion in Europe today and next +steps what what happens quite quite + + align:start position:0% +steps what what happens quite quite + + + align:start position:0% +steps what what happens quite quite +often it's in public administration that + + align:start position:0% +often it's in public administration that + + + align:start position:0% +often it's in public administration that +depending on the application cases a + + align:start position:0% +depending on the application cases a + + + align:start position:0% +depending on the application cases a +topic pops up in different um different + + align:start position:0% +topic pops up in different um different + + + align:start position:0% +topic pops up in different um different +uh administrations and for example there + + align:start position:0% +uh administrations and for example there + + + align:start position:0% +uh administrations and for example there +is the topic on standardization RFID in + + align:start position:0% +is the topic on standardization RFID in + + + align:start position:0% +is the topic on standardization RFID in +frequency it's about um Customs issu + + align:start position:0% +frequency it's about um Customs issu + + + align:start position:0% +frequency it's about um Customs issu +it's about Enterprise cor Corporation + + align:start position:0% +it's about Enterprise cor Corporation + + + align:start position:0% +it's about Enterprise cor Corporation +Supply Chain management and then we + + align:start position:0% +Supply Chain management and then we + + + align:start position:0% +Supply Chain management and then we +discovered actually last year that we + + align:start position:0% +discovered actually last year that we + + + align:start position:0% +discovered actually last year that we +should um realign our forces and should + + align:start position:0% +should um realign our forces and should + + + align:start position:0% +should um realign our forces and should +go for a coherent approach so actually + + align:start position:0% +go for a coherent approach so actually + + + align:start position:0% +go for a coherent approach so actually +12 director General + + align:start position:0% +12 director General + + + align:start position:0% +12 director General +um then since then try to work together + + align:start position:0% +um then since then try to work together + + + align:start position:0% +um then since then try to work together +and actually my head of unit is um the + + align:start position:0% +and actually my head of unit is um the + + + align:start position:0% +and actually my head of unit is um the +coordinator and my colleague from from + + align:start position:0% +coordinator and my colleague from from + + + align:start position:0% +coordinator and my colleague from from +and myself we are managing this um inter + + align:start position:0% +and myself we are managing this um inter + + + align:start position:0% +and myself we are managing this um inter +service working group which is quite + + align:start position:0% +service working group which is quite + + + align:start position:0% +service working group which is quite +promising and seems to be a good um + + align:start position:0% +promising and seems to be a good um + + + align:start position:0% +promising and seems to be a good um +opportunity a good um action for Europe + + align:start position:0% +opportunity a good um action for Europe + + + align:start position:0% +opportunity a good um action for Europe +actually what we want to do is of course + + align:start position:0% +actually what we want to do is of course + + + align:start position:0% +actually what we want to do is of course +go for a horizontal coordination of + + align:start position:0% +go for a horizontal coordination of + + + align:start position:0% +go for a horizontal coordination of +activities in RFID in + + align:start position:0% +activities in RFID in + + + align:start position:0% +activities in RFID in +Europe try to cooperate with national + + align:start position:0% +Europe try to cooperate with national + + + align:start position:0% +Europe try to cooperate with national +authorities and solarization bodies as + + align:start position:0% +authorities and solarization bodies as + + + align:start position:0% +authorities and solarization bodies as +it has to do a lot with aligning I would + + align:start position:0% +it has to do a lot with aligning I would + + + align:start position:0% +it has to do a lot with aligning I would +say efforts and standards and provision + + align:start position:0% +say efforts and standards and provision + + + align:start position:0% +say efforts and standards and provision +of ground for international cooporation + + align:start position:0% +of ground for international cooporation + + + align:start position:0% +of ground for international cooporation +of course we see that um Europe as all + + align:start position:0% +of course we see that um Europe as all + + + align:start position:0% +of course we see that um Europe as all +the big economic zones tries to be one + + align:start position:0% +the big economic zones tries to be one + + + align:start position:0% +the big economic zones tries to be one +of the leading ones but still as RFID is + + align:start position:0% +of the leading ones but still as RFID is + + + align:start position:0% +of the leading ones but still as RFID is +a global issue we have to always go for + + align:start position:0% +a global issue we have to always go for + + + align:start position:0% +a global issue we have to always go for +a global cooporation and I give you some + + align:start position:0% +a global cooporation and I give you some + + + align:start position:0% +a global cooporation and I give you some +examples we had quite some contact with + + align:start position:0% +examples we had quite some contact with + + + align:start position:0% +examples we had quite some contact with +Dan capio from the Department of + + align:start position:0% +Dan capio from the Department of + + + align:start position:0% +Dan capio from the Department of +Commerce + + align:start position:0% +Commerce + + + align:start position:0% +Commerce +there was recently the US Information + + align:start position:0% +there was recently the US Information + + + align:start position:0% +there was recently the US Information +Society dialogue and one major issue was + + align:start position:0% +Society dialogue and one major issue was + + + align:start position:0% +Society dialogue and one major issue was +RFID there are informal discussions + + align:start position:0% +RFID there are informal discussions + + + align:start position:0% +RFID there are informal discussions +since uh last year and there was + + align:start position:0% +since uh last year and there was + + + align:start position:0% +since uh last year and there was +attendance for us on a um Department of + + align:start position:0% +attendance for us on a um Department of + + + align:start position:0% +attendance for us on a um Department of +Commerce + + align:start position:0% +Commerce + + + align:start position:0% +Commerce +workshop last week our commissioner + + align:start position:0% +workshop last week our commissioner + + + align:start position:0% +workshop last week our commissioner +reading uh visited China so there was a + + align:start position:0% +reading uh visited China so there was a + + + align:start position:0% +reading uh visited China so there was a +contact with the European Ministry of + + align:start position:0% +contact with the European Ministry of + + + align:start position:0% +contact with the European Ministry of +sorry with the China Ministry of Science + + align:start position:0% +sorry with the China Ministry of Science + + + align:start position:0% +sorry with the China Ministry of Science +and + + align:start position:0% +and + + + align:start position:0% +and +Technology we cooperate uh with the oecd + + align:start position:0% +Technology we cooperate uh with the oecd + + + align:start position:0% +Technology we cooperate uh with the oecd +and we have as well a transatlantic uh + + align:start position:0% +and we have as well a transatlantic uh + + + align:start position:0% +and we have as well a transatlantic uh +consumer Di + + align:start position:0% + + + + align:start position:0% + +um what we normally do in Europe is + + align:start position:0% +um what we normally do in Europe is + + + align:start position:0% +um what we normally do in Europe is +apart from National research programs + + align:start position:0% +apart from National research programs + + + align:start position:0% +apart from National research programs +that we have so-called M multianal + + align:start position:0% +that we have so-called M multianal + + + align:start position:0% +that we have so-called M multianal +framework programs which are like some + + align:start position:0% +framework programs which are like some + + + align:start position:0% +framework programs which are like some +sort of some big machineries that based + + align:start position:0% +sort of some big machineries that based + + + align:start position:0% +sort of some big machineries that based +on extensive stakeholder discussion + + align:start position:0% +on extensive stakeholder discussion + + + align:start position:0% +on extensive stakeholder discussion +consultation we're going to develop + + align:start position:0% +consultation we're going to develop + + + align:start position:0% +consultation we're going to develop +specific uh research subjects which then + + align:start position:0% +specific uh research subjects which then + + + align:start position:0% +specific uh research subjects which then +are updated each um two + + align:start position:0% +are updated each um two + + + align:start position:0% +are updated each um two +years and as you can see that we do + + align:start position:0% +years and as you can see that we do + + + align:start position:0% +years and as you can see that we do +quite a lot on Al research since 10 + + align:start position:0% +quite a lot on Al research since 10 + + + align:start position:0% +quite a lot on Al research since 10 +years difference between project and + + align:start position:0% +years difference between project and + + + align:start position:0% +years difference between project and +funding is that this is always a + + align:start position:0% +funding is that this is always a + + + align:start position:0% +funding is that this is always a +collaborative funding so we normally ask + + align:start position:0% +collaborative funding so we normally ask + + + align:start position:0% +collaborative funding so we normally ask +the participants which means um research + + align:start position:0% +the participants which means um research + + + align:start position:0% +the participants which means um research +institutes and um companies to + + align:start position:0% +institutes and um companies to + + + align:start position:0% +institutes and um companies to +contribute uh up to 50% of um of the + + align:start position:0% +contribute uh up to 50% of um of the + + + align:start position:0% +contribute uh up to 50% of um of the +project budget to to carry out the work + + align:start position:0% +project budget to to carry out the work + + + align:start position:0% +project budget to to carry out the work +um this figure gives you only idea on + + align:start position:0% +um this figure gives you only idea on + + + align:start position:0% +um this figure gives you only idea on +European level and a part of this I + + align:start position:0% +European level and a part of this I + + + align:start position:0% +European level and a part of this I +think you can easily double this is we + + align:start position:0% +think you can easily double this is we + + + align:start position:0% +think you can easily double this is we +have all of of course in different + + align:start position:0% +have all of of course in different + + + align:start position:0% +have all of of course in different +member states national um research and + + align:start position:0% +member states national um research and + + + align:start position:0% +member states national um research and +what we try since some years is to go + + align:start position:0% +what we try since some years is to go + + + align:start position:0% +what we try since some years is to go +for so-called European research area + + align:start position:0% +for so-called European research area + + + align:start position:0% +for so-called European research area +which means that we try to coordinate + + align:start position:0% +which means that we try to coordinate + + + align:start position:0% +which means that we try to coordinate +better European and um Nationwide + + align:start position:0% +better European and um Nationwide + + + align:start position:0% +better European and um Nationwide +research and I think it starts to + + align:start position:0% +research and I think it starts to + + + align:start position:0% +research and I think it starts to +work just to give a glance on the topics + + align:start position:0% +work just to give a glance on the topics + + + align:start position:0% +work just to give a glance on the topics +we cover it's a very colorful pile and + + align:start position:0% +we cover it's a very colorful pile and + + + align:start position:0% +we cover it's a very colorful pile and +it shows actually that it goes really + + align:start position:0% +it shows actually that it goes really + + + align:start position:0% +it shows actually that it goes really +from Supply Chain management e + + align:start position:0% +from Supply Chain management e + + + align:start position:0% +from Supply Chain management e +government Justice Liberty and freedom + + align:start position:0% +government Justice Liberty and freedom + + + align:start position:0% +government Justice Liberty and freedom +I'm just picking up some smart devices + + align:start position:0% +I'm just picking up some smart devices + + + align:start position:0% +I'm just picking up some smart devices +goes into nanot technology so there + + align:start position:0% +goes into nanot technology so there + + + align:start position:0% +goes into nanot technology so there +really a big uh bundle and a bunch of a + + align:start position:0% +really a big uh bundle and a bunch of a + + + align:start position:0% +really a big uh bundle and a bunch of a +um diverse subjects all dealing around + + align:start position:0% +um diverse subjects all dealing around + + + align:start position:0% +um diverse subjects all dealing around +on + + align:start position:0% + + + + align:start position:0% + +RFID what we see today on as typical + + align:start position:0% +RFID what we see today on as typical + + + align:start position:0% +RFID what we see today on as typical +topics in + + align:start position:0% +topics in + + + align:start position:0% +topics in +Europe is in terms of the application + + align:start position:0% +Europe is in terms of the application + + + align:start position:0% +Europe is in terms of the application +areas is the supply chain Logistics uh + + align:start position:0% +areas is the supply chain Logistics uh + + + align:start position:0% +areas is the supply chain Logistics uh +on the Forefront we see product life + + align:start position:0% +on the Forefront we see product life + + + align:start position:0% +on the Forefront we see product life +cycle after sales service intelligent + + align:start position:0% +cycle after sales service intelligent + + + align:start position:0% +cycle after sales service intelligent +maintainance M for you see uh health is + + align:start position:0% +maintainance M for you see uh health is + + + align:start position:0% +maintainance M for you see uh health is +a very important issue and to some + + align:start position:0% +a very important issue and to some + + + align:start position:0% +a very important issue and to some +extent as well inclusion which means how + + align:start position:0% +extent as well inclusion which means how + + + align:start position:0% +extent as well inclusion which means how +can we help um Elder and disabled people + + align:start position:0% +can we help um Elder and disabled people + + + align:start position:0% +can we help um Elder and disabled people +people's additional needs to participate + + align:start position:0% +people's additional needs to participate + + + align:start position:0% +people's additional needs to participate +in a modern society in particular as you + + align:start position:0% +in a modern society in particular as you + + + align:start position:0% +in a modern society in particular as you +notice that Europe always try or has + + align:start position:0% +notice that Europe always try or has + + + align:start position:0% +notice that Europe always try or has +give a gives a special emphasis on + + align:start position:0% +give a gives a special emphasis on + + + align:start position:0% +give a gives a special emphasis on +so-called social coherence and and + + align:start position:0% +so-called social coherence and and + + + align:start position:0% +so-called social coherence and and +inclusion in terms of research and + + align:start position:0% +inclusion in terms of research and + + + align:start position:0% +inclusion in terms of research and +development it's basically about te R + + align:start position:0% +development it's basically about te R + + + align:start position:0% +development it's basically about te R +Hardware it's about smart sensors it's + + align:start position:0% +Hardware it's about smart sensors it's + + + align:start position:0% +Hardware it's about smart sensors it's +about software application it's about + + align:start position:0% +about software application it's about + + + align:start position:0% +about software application it's about +nanomaterials interoperability and + + align:start position:0% +nanomaterials interoperability and + + + align:start position:0% +nanomaterials interoperability and +standards uh basically frequencies data + + align:start position:0% +standards uh basically frequencies data + + + align:start position:0% +standards uh basically frequencies data +structures and tag + + align:start position:0% +structures and tag + + + align:start position:0% +structures and tag +interrogation and particularly on this + + align:start position:0% +interrogation and particularly on this + + + align:start position:0% +interrogation and particularly on this +in terms of frequency of course we have + + align:start position:0% +in terms of frequency of course we have + + + align:start position:0% +in terms of frequency of course we have +to + + align:start position:0% +to + + + align:start position:0% +to +harmonize uh frequency spectrums for + + align:start position:0% +harmonize uh frequency spectrums for + + + align:start position:0% +harmonize uh frequency spectrums for +RFID usage in 25 member states and um + + align:start position:0% +RFID usage in 25 member states and um + + + align:start position:0% +RFID usage in 25 member states and um +there we are on good track we gave as + + align:start position:0% +there we are on good track we gave as + + + align:start position:0% +there we are on good track we gave as +well a particular emphasis on RFID + + align:start position:0% +well a particular emphasis on RFID + + + align:start position:0% +well a particular emphasis on RFID +governance which means rules and + + align:start position:0% +governance which means rules and + + + align:start position:0% +governance which means rules and +procedures competition robot Ness in + + align:start position:0% +procedures competition robot Ness in + + + align:start position:0% +procedures competition robot Ness in +terms of um object naming services and + + align:start position:0% +terms of um object naming services and + + + align:start position:0% +terms of um object naming services and +Discovery Services as we see this is um + + align:start position:0% +Discovery Services as we see this is um + + + align:start position:0% +Discovery Services as we see this is um +a very important issue and want of + + align:start position:0% +a very important issue and want of + + + align:start position:0% +a very important issue and want of +course to have um no let me say + + align:start position:0% +course to have um no let me say + + + align:start position:0% +course to have um no let me say +incumbent power so really would like to + + align:start position:0% +incumbent power so really would like to + + + align:start position:0% +incumbent power so really would like to +go there for some mixture between a open + + align:start position:0% +go there for some mixture between a open + + + align:start position:0% +go there for some mixture between a open +and competitive + + align:start position:0% +and competitive + + + align:start position:0% +and competitive +approach privacy and data protection is + + align:start position:0% +approach privacy and data protection is + + + align:start position:0% +approach privacy and data protection is +of course high on the political agenda + + align:start position:0% +of course high on the political agenda + + + align:start position:0% +of course high on the political agenda +and as well all security issues around + + align:start position:0% +and as well all security issues around + + + align:start position:0% +and as well all security issues around +RFID what we see as well is and our RPI + + align:start position:0% +RFID what we see as well is and our RPI + + + align:start position:0% +RFID what we see as well is and our RPI +free standards intellectual property + + align:start position:0% +free standards intellectual property + + + align:start position:0% +free standards intellectual property +rights International Trade Health + + align:start position:0% +rights International Trade Health + + + align:start position:0% +rights International Trade Health +environment identity left ethical + + align:start position:0% +environment identity left ethical + + + align:start position:0% +environment identity left ethical +aspects I think are going to become very + + align:start position:0% +aspects I think are going to become very + + + align:start position:0% +aspects I think are going to become very +important and what we see as well as + + align:start position:0% +important and what we see as well as + + + align:start position:0% +important and what we see as well as +labor practices so we try to have a look + + align:start position:0% +labor practices so we try to have a look + + + align:start position:0% +labor practices so we try to have a look +that um usage of RFID might have some + + align:start position:0% +that um usage of RFID might have some + + + align:start position:0% +that um usage of RFID might have some +impact on not only negative but might + + align:start position:0% +impact on not only negative but might + + + align:start position:0% +impact on not only negative but might +have impact of course on labor forces + + align:start position:0% +have impact of course on labor forces + + + align:start position:0% +have impact of course on labor forces +and perhaps you do have to to act as + + align:start position:0% +and perhaps you do have to to act as + + + align:start position:0% +and perhaps you do have to to act as +well besides some technical + + align:start position:0% +well besides some technical + + + align:start position:0% +well besides some technical +technological development um to provide + + align:start position:0% +technological development um to provide + + + align:start position:0% +technological development um to provide +some measures + + align:start position:0% + + + + align:start position:0% + +I give you here some typical examples uh + + align:start position:0% +I give you here some typical examples uh + + + align:start position:0% +I give you here some typical examples uh +what we try to do in European research + + align:start position:0% +what we try to do in European research + + + align:start position:0% +what we try to do in European research +and RFID and I'm proud that in two + + align:start position:0% +and RFID and I'm proud that in two + + + align:start position:0% +and RFID and I'm proud that in two +projects we have outdoor daps included + + align:start position:0% +projects we have outdoor daps included + + + align:start position:0% +projects we have outdoor daps included +for example Professor fish's + + align:start position:0% +for example Professor fish's + + + align:start position:0% +for example Professor fish's +participating as well I think it's even + + align:start position:0% +participating as well I think it's even + + + align:start position:0% +participating as well I think it's even +the the MIT and as part of the Bridge + + align:start position:0% +the the MIT and as part of the Bridge + + + align:start position:0% +the the MIT and as part of the Bridge +Project in which EPC Global and gs1 + + align:start position:0% +Project in which EPC Global and gs1 + + + align:start position:0% +Project in which EPC Global and gs1 +organizations are going to participate + + align:start position:0% +organizations are going to participate + + + align:start position:0% +organizations are going to participate +so what you see for example apart from + + align:start position:0% +so what you see for example apart from + + + align:start position:0% +so what you see for example apart from +Supply Chain management it's really + + align:start position:0% +Supply Chain management it's really + + + align:start position:0% +Supply Chain management it's really +about um + + align:start position:0% +about um + + + align:start position:0% +about um +using RFID to go for a let me say a + + align:start position:0% +using RFID to go for a let me say a + + + align:start position:0% +using RFID to go for a let me say a +better customer service apart from just + + align:start position:0% +better customer service apart from just + + + align:start position:0% +better customer service apart from just +providing the right product the right + + align:start position:0% +providing the right product the right + + + align:start position:0% +providing the right product the right +time and the right um shelf or display + + align:start position:0% +time and the right um shelf or display + + + align:start position:0% +time and the right um shelf or display +it's really to say how could we use um + + align:start position:0% +it's really to say how could we use um + + + align:start position:0% +it's really to say how could we use um +data to um save resources and improve + + align:start position:0% +data to um save resources and improve + + + align:start position:0% +data to um save resources and improve +customer + + align:start position:0% +customer + + + align:start position:0% +customer +service I think uh RFID solution for + + align:start position:0% +service I think uh RFID solution for + + + align:start position:0% +service I think uh RFID solution for +global environment bridge is 3 to say + + align:start position:0% +global environment bridge is 3 to say + + + align:start position:0% +global environment bridge is 3 to say +that in seven application sectors from + + align:start position:0% +that in seven application sectors from + + + align:start position:0% +that in seven application sectors from +some sort of European perspective in a + + align:start position:0% +some sort of European perspective in a + + + align:start position:0% +some sort of European perspective in a +globalwide um frame um the gs1 + + align:start position:0% +globalwide um frame um the gs1 + + + align:start position:0% +globalwide um frame um the gs1 +organizations would like to to drive um + + align:start position:0% +organizations would like to to drive um + + + align:start position:0% +organizations would like to to drive um +the roll out of um APC + + align:start position:0% +the roll out of um APC + + + align:start position:0% +the roll out of um APC +Global yesterday we talked as well about + + align:start position:0% +Global yesterday we talked as well about + + + align:start position:0% +Global yesterday we talked as well about +on um anti-c counter fighting Solutions + + align:start position:0% +on um anti-c counter fighting Solutions + + + align:start position:0% +on um anti-c counter fighting Solutions +it's very important and for example + + align:start position:0% +it's very important and for example + + + align:start position:0% +it's very important and for example +another ex um important issue is the uh + + align:start position:0% +another ex um important issue is the uh + + + align:start position:0% +another ex um important issue is the uh +quality of food to traceability of of + + align:start position:0% +quality of food to traceability of of + + + align:start position:0% +quality of food to traceability of of +Liv look there was um some Scandal on on + + align:start position:0% +Liv look there was um some Scandal on on + + + align:start position:0% +Liv look there was um some Scandal on on +on um on meat some years ago so there's + + align:start position:0% +on um on meat some years ago so there's + + + align:start position:0% +on um on meat some years ago so there's +some sort of uh sensibility and + + align:start position:0% +some sort of uh sensibility and + + + align:start position:0% +some sort of uh sensibility and +awareness in Europe to have good food + + align:start position:0% +awareness in Europe to have good food + + + align:start position:0% +awareness in Europe to have good food +and life + + align:start position:0% +and life + + + align:start position:0% +and life +quality + + align:start position:0% +quality + + + align:start position:0% +quality +perhaps what we see as well it's not + + align:start position:0% +perhaps what we see as well it's not + + + align:start position:0% +perhaps what we see as well it's not +only that we see + + align:start position:0% +only that we see + + + align:start position:0% +only that we see +RFID and itself we try to see it in in a + + align:start position:0% +RFID and itself we try to see it in in a + + + align:start position:0% +RFID and itself we try to see it in in a +broader context which is apart from + + align:start position:0% +broader context which is apart from + + + align:start position:0% +broader context which is apart from +saying it's the internet of things that + + align:start position:0% +saying it's the internet of things that + + + align:start position:0% +saying it's the internet of things that +we say uh tomorrow the world will + + align:start position:0% +we say uh tomorrow the world will + + + align:start position:0% +we say uh tomorrow the world will +networked and and consisting of a lot of + + align:start position:0% +networked and and consisting of a lot of + + + align:start position:0% +networked and and consisting of a lot of +intelligent products and uh objectives + + align:start position:0% +intelligent products and uh objectives + + + align:start position:0% +intelligent products and uh objectives +in this case of course you have to go + + align:start position:0% +in this case of course you have to go + + + align:start position:0% +in this case of course you have to go +for different um business models + + align:start position:0% +for different um business models + + + align:start position:0% +for different um business models +different development processes new um + + align:start position:0% +different development processes new um + + + align:start position:0% +different development processes new um +ways of Corporation of suppliers and + + align:start position:0% +ways of Corporation of suppliers and + + + align:start position:0% +ways of Corporation of suppliers and +after service sorry after sales service + + align:start position:0% +after service sorry after sales service + + + align:start position:0% +after service sorry after sales service +providers I think it's about um a very + + align:start position:0% +providers I think it's about um a very + + + align:start position:0% +providers I think it's about um a very +robust robust and safe it and network + + align:start position:0% +robust robust and safe it and network + + + align:start position:0% +robust robust and safe it and network +infrastructure as the network will the + + align:start position:0% +infrastructure as the network will the + + + align:start position:0% +infrastructure as the network will the +major backbone uh to facilitate the the + + align:start position:0% +major backbone uh to facilitate the the + + + align:start position:0% +major backbone uh to facilitate the the +existence of all this intelligent + + align:start position:0% +existence of all this intelligent + + + align:start position:0% +existence of all this intelligent +objectives and I think of of course it's + + align:start position:0% +objectives and I think of of course it's + + + align:start position:0% +objectives and I think of of course it's +how in a world of increasing complexity + + align:start position:0% +how in a world of increasing complexity + + + align:start position:0% +how in a world of increasing complexity +which where and how we should use + + align:start position:0% +which where and how we should use + + + align:start position:0% +which where and how we should use +intelligent machines to handle um to + + align:start position:0% +intelligent machines to handle um to + + + align:start position:0% +intelligent machines to handle um to +handle all datas and information which I + + align:start position:0% +handle all datas and information which I + + + align:start position:0% +handle all datas and information which I +think it would be more and more + + align:start position:0% +think it would be more and more + + + align:start position:0% +think it would be more and more +difficult for human beings to cope with + + align:start position:0% +difficult for human beings to cope with + + + align:start position:0% +difficult for human beings to cope with +the increasing amount of data and + + align:start position:0% +the increasing amount of data and + + + align:start position:0% +the increasing amount of data and +information + + align:start position:0% +information + + + align:start position:0% +information +what we see this year is um very + + align:start position:0% +what we see this year is um very + + + align:start position:0% +what we see this year is um very +important from European perspective as + + align:start position:0% +important from European perspective as + + + align:start position:0% +important from European perspective as +far as Rd is concerned you're going to + + align:start position:0% +far as Rd is concerned you're going to + + + align:start position:0% +far as Rd is concerned you're going to +shape the next uh framework program it's + + align:start position:0% +shape the next uh framework program it's + + + align:start position:0% +shape the next uh framework program it's +the fp7 which is going to start in + + align:start position:0% +the fp7 which is going to start in + + + align:start position:0% +the fp7 which is going to start in + + align:start position:0% + + + align:start position:0% +furthermore we try to provide + + align:start position:0% +furthermore we try to provide + + + align:start position:0% +furthermore we try to provide +orientation for stakeholders we talked a + + align:start position:0% +orientation for stakeholders we talked a + + + align:start position:0% +orientation for stakeholders we talked a +lot to Intel APC Global VAR sign + + align:start position:0% +lot to Intel APC Global VAR sign + + + align:start position:0% +lot to Intel APC Global VAR sign +consumer organizations and apart from + + align:start position:0% +consumer organizations and apart from + + + align:start position:0% +consumer organizations and apart from +the idea that there is or is not uh the + + align:start position:0% +the idea that there is or is not uh the + + + align:start position:0% +the idea that there is or is not uh the +need for some regulations regulation we + + align:start position:0% +need for some regulations regulation we + + + align:start position:0% +need for some regulations regulation we +see that um quite often it's a question + + align:start position:0% +see that um quite often it's a question + + + align:start position:0% +see that um quite often it's a question +of orientation saying what would be a + + align:start position:0% +of orientation saying what would be a + + + align:start position:0% +of orientation saying what would be a +good practice or on on on what should we + + align:start position:0% +good practice or on on on what should we + + + align:start position:0% +good practice or on on on what should we +conclude to go to go ahead and for this + + align:start position:0% +conclude to go to go ahead and for this + + + align:start position:0% +conclude to go to go ahead and for this +we try to carry out as part of a public + + align:start position:0% +we try to carry out as part of a public + + + align:start position:0% +we try to carry out as part of a public +consultation five important workshops + + align:start position:0% +consultation five important workshops + + + align:start position:0% +consultation five important workshops +where we try to invite relevant + + align:start position:0% +where we try to invite relevant + + + align:start position:0% +where we try to invite relevant +stakeholders to come up with ideas how + + align:start position:0% +stakeholders to come up with ideas how + + + align:start position:0% +stakeholders to come up with ideas how +we should go on what should be in terms + + align:start position:0% +we should go on what should be in terms + + + align:start position:0% +we should go on what should be in terms +of Regulation but and as well in terms + + align:start position:0% +of Regulation but and as well in terms + + + align:start position:0% +of Regulation but and as well in terms +of um let me say Solutions um + + align:start position:0% +of um let me say Solutions um + + + align:start position:0% +of um let me say Solutions um +definitions what should be a good way + + align:start position:0% +definitions what should be a good way + + + align:start position:0% +definitions what should be a good way +for Europe to go forward in the balance + + align:start position:0% +for Europe to go forward in the balance + + + align:start position:0% +for Europe to go forward in the balance +between uh being competitive and at the + + align:start position:0% +between uh being competitive and at the + + + align:start position:0% +between uh being competitive and at the +same time try to um to stick to European + + align:start position:0% +same time try to um to stick to European + + + align:start position:0% +same time try to um to stick to European +values as we try always to to carry them + + align:start position:0% +values as we try always to to carry them + + + align:start position:0% +values as we try always to to carry them +on um as I said as well um I think that + + align:start position:0% +on um as I said as well um I think that + + + align:start position:0% +on um as I said as well um I think that +we at the end of the year we could have + + align:start position:0% +we at the end of the year we could have + + + align:start position:0% +we at the end of the year we could have +some ideas about political action in + + align:start position:0% +some ideas about political action in + + + align:start position:0% +some ideas about political action in +order to to drive uh the usage of + + align:start position:0% +order to to drive uh the usage of + + + align:start position:0% +order to to drive uh the usage of +RFID um + + align:start position:0% +RFID um + + + align:start position:0% +RFID um +I would like to invite you if you anyhow + + align:start position:0% +I would like to invite you if you anyhow + + + align:start position:0% +I would like to invite you if you anyhow +in Europe or try to come over we're + + align:start position:0% +in Europe or try to come over we're + + + align:start position:0% +in Europe or try to come over we're +going to have two important workshops + + align:start position:0% +going to have two important workshops + + + align:start position:0% +going to have two important workshops +soon one is called from RF The Internet + + align:start position:0% +soon one is called from RF The Internet + + + align:start position:0% +soon one is called from RF The Internet +of Things it's more about sensor + + align:start position:0% +of Things it's more about sensor + + + align:start position:0% +of Things it's more about sensor +networks and ideas they discussed + + align:start position:0% +networks and ideas they discussed + + + align:start position:0% +networks and ideas they discussed +yesterday so I would invite you to come + + align:start position:0% +yesterday so I would invite you to come + + + align:start position:0% +yesterday so I would invite you to come +over to participant in this Workshop or + + align:start position:0% +over to participant in this Workshop or + + + align:start position:0% +over to participant in this Workshop or +one week earlier is uh the slightly + + align:start position:0% +one week earlier is uh the slightly + + + align:start position:0% +one week earlier is uh the slightly +enhanced perspective it's about ambient + + align:start position:0% +enhanced perspective it's about ambient + + + align:start position:0% +enhanced perspective it's about ambient +intelligent Technologies to enhance the + + align:start position:0% +intelligent Technologies to enhance the + + + align:start position:0% +intelligent Technologies to enhance the +product life cycle which goes more + + align:start position:0% +product life cycle which goes more + + + align:start position:0% +product life cycle which goes more +towards the idea um of networked and + + align:start position:0% +towards the idea um of networked and + + + align:start position:0% +towards the idea um of networked and +intelligent um objectives and further + + align:start position:0% +intelligent um objectives and further + + + align:start position:0% +intelligent um objectives and further +research needs and of course we try to + + align:start position:0% +research needs and of course we try to + + + align:start position:0% +research needs and of course we try to +take + + align:start position:0% +take + + + align:start position:0% +take +this to um get the ideas and to fill up + + align:start position:0% +this to um get the ideas and to fill up + + + align:start position:0% +this to um get the ideas and to fill up +the next uh work programs which then of + + align:start position:0% +the next uh work programs which then of + + + align:start position:0% +the next uh work programs which then of +course later on will lead to call for + + align:start position:0% +course later on will lead to call for + + + align:start position:0% +course later on will lead to call for +tenders and um then of course we would + + align:start position:0% +tenders and um then of course we would + + + align:start position:0% +tenders and um then of course we would +like to invite you to participate and + + align:start position:0% +like to invite you to participate and + + + align:start position:0% +like to invite you to participate and +last word to say it's basically European + + align:start position:0% +last word to say it's basically European + + + align:start position:0% +last word to say it's basically European +research but there are lot of mechanisms + + align:start position:0% +research but there are lot of mechanisms + + + align:start position:0% +research but there are lot of mechanisms +to going for international corporation + + align:start position:0% +to going for international corporation + + + align:start position:0% +to going for international corporation +which Asia China and us okay thank you + + align:start position:0% +which Asia China and us okay thank you + + + align:start position:0% +which Asia China and us okay thank you +very + + align:start position:0% + + + + align:start position:0% + +much thank you very much our our next + + align:start position:0% +much thank you very much our our next + + + align:start position:0% +much thank you very much our our next +speaker is a colleague from the Auto ID + + align:start position:0% +speaker is a colleague from the Auto ID + + + align:start position:0% +speaker is a colleague from the Auto ID +Labs at ICU in SE Korea his name is dong + + align:start position:0% +Labs at ICU in SE Korea his name is dong + + + align:start position:0% +Labs at ICU in SE Korea his name is dong +Kim and he is uh uh his talk is on the + + align:start position:0% +Kim and he is uh uh his talk is on the + + + align:start position:0% +Kim and he is uh uh his talk is on the +evolvable network of tiny sensors + + align:start position:0% +evolvable network of tiny sensors + + + align:start position:0% +evolvable network of tiny sensors +otherwise known as ants and the hanra + + align:start position:0% +otherwise known as ants and the hanra + + + align:start position:0% +otherwise known as ants and the hanra +mountain disaster Management program + + align:start position:0% +mountain disaster Management program + + + align:start position:0% +mountain disaster Management program +which We Gather is one of the flagship + + align:start position:0% +which We Gather is one of the flagship + + + align:start position:0% +which We Gather is one of the flagship +programs in Korea thank you + + align:start position:0% + + + + align:start position:0% + +thanks uh good + + align:start position:0% +thanks uh good + + + align:start position:0% +thanks uh good +afternoon uh yeah first of all I'd like + + align:start position:0% +afternoon uh yeah first of all I'd like + + + align:start position:0% +afternoon uh yeah first of all I'd like +to thank you also Boston you know the + + align:start position:0% +to thank you also Boston you know the + + + align:start position:0% +to thank you also Boston you know the +poon gave me a gift you know yesterday + + align:start position:0% +poon gave me a gift you know yesterday + + + align:start position:0% +poon gave me a gift you know yesterday +it's called you know I just called the + + align:start position:0% +it's called you know I just called the + + + align:start position:0% +it's called you know I just called the +call so without call you know the my my + + align:start position:0% +call so without call you know the my my + + + align:start position:0% +call so without call you know the my my +actually my original voice is much worse + + align:start position:0% +actually my original voice is much worse + + + align:start position:0% +actually my original voice is much worse +than this you know thank thank you + + align:start position:0% +than this you know thank thank you + + + align:start position:0% +than this you know thank thank you +both uh my you know the talk topic is a + + align:start position:0% +both uh my you know the talk topic is a + + + align:start position:0% +both uh my you know the talk topic is a +little different you know from original + + align:start position:0% +little different you know from original + + + align:start position:0% +little different you know from original +RF id you know I'm more interested in + + align:start position:0% +RF id you know I'm more interested in + + + align:start position:0% +RF id you know I'm more interested in +you know the sensor Network and um so uh + + align:start position:0% +you know the sensor Network and um so uh + + + align:start position:0% +you know the sensor Network and um so uh +actually the ANS is the project you know + + align:start position:0% +actually the ANS is the project you know + + + align:start position:0% +actually the ANS is the project you know +I have carried out lot of for years and + + align:start position:0% +I have carried out lot of for years and + + + align:start position:0% +I have carried out lot of for years and +the ends aimed for you know some uh + + align:start position:0% +the ends aimed for you know some uh + + + align:start position:0% +the ends aimed for you know some uh +public sense Network you know we would + + align:start position:0% +public sense Network you know we would + + + align:start position:0% +public sense Network you know we would +like in Korea we would like to deploy + + align:start position:0% +like in Korea we would like to deploy + + + align:start position:0% +like in Korea we would like to deploy +sense Network in you know in the nation + + align:start position:0% +sense Network in you know in the nation + + + align:start position:0% +sense Network in you know in the nation +like uh internet internet is you know + + align:start position:0% +like uh internet internet is you know + + + align:start position:0% +like uh internet internet is you know +the now worldwide right so uh that's a + + align:start position:0% +the now worldwide right so uh that's a + + + align:start position:0% +the now worldwide right so uh that's a +public sense net without public sense + + align:start position:0% +public sense net without public sense + + + align:start position:0% +public sense net without public sense +Network you know we we we cannot the + + align:start position:0% +Network you know we we we cannot the + + + align:start position:0% +Network you know we we we cannot the +companies and government you know the uh + + align:start position:0% +companies and government you know the uh + + + align:start position:0% +companies and government you know the uh +organization cannot you know the share + + align:start position:0% +organization cannot you know the share + + + align:start position:0% +organization cannot you know the share +the you know the sense information so we + + align:start position:0% +the you know the sense information so we + + + align:start position:0% +the you know the sense information so we +need some you know standardization of a + + align:start position:0% +need some you know standardization of a + + + align:start position:0% +need some you know standardization of a +sense Network that's a public sense + + align:start position:0% +sense Network that's a public sense + + + align:start position:0% +sense Network that's a public sense +Network also uh there are another + + align:start position:0% +Network also uh there are another + + + align:start position:0% +Network also uh there are another +research topic you know that's EPC sense + + align:start position:0% +research topic you know that's EPC sense + + + align:start position:0% +research topic you know that's EPC sense +Network you know the uh actually you + + align:start position:0% +Network you know the uh actually you + + + align:start position:0% +Network you know the uh actually you +already know that you know the EPC you + + align:start position:0% +already know that you know the EPC you + + + align:start position:0% +already know that you know the EPC you +know Auto lefts already planned you know + + align:start position:0% +know Auto lefts already planned you know + + + align:start position:0% +know Auto lefts already planned you know +to develop EPC class two three four and + + align:start position:0% +to develop EPC class two three four and + + + align:start position:0% +to develop EPC class two three four and +five you know actually class four Tech + + align:start position:0% +five you know actually class four Tech + + + align:start position:0% +five you know actually class four Tech +is Ador active uh Tech that's very + + align:start position:0% +is Ador active uh Tech that's very + + + align:start position:0% +is Ador active uh Tech that's very +similar to the you know the sense + + align:start position:0% +similar to the you know the sense + + + align:start position:0% +similar to the you know the sense +Network so uh actually this is not a new + + align:start position:0% +Network so uh actually this is not a new + + + align:start position:0% +Network so uh actually this is not a new +topic so this is a Reserva topic so I'd + + align:start position:0% +topic so this is a Reserva topic so I'd + + + align:start position:0% +topic so this is a Reserva topic so I'd +like to propose you know to uh research + + align:start position:0% +like to propose you know to uh research + + + align:start position:0% +like to propose you know to uh research +more on EP sensor + + align:start position:0% +more on EP sensor + + + align:start position:0% +more on EP sensor +network uh this is the contents you know + + align:start position:0% +network uh this is the contents you know + + + align:start position:0% +network uh this is the contents you know +I'd like to talk today the first one is + + align:start position:0% +I'd like to talk today the first one is + + + align:start position:0% +I'd like to talk today the first one is +the ubiquitous sens Network you know the + + align:start position:0% +the ubiquitous sens Network you know the + + + align:start position:0% +the ubiquitous sens Network you know the +uh that's some uh new terminologies uh + + align:start position:0% +uh that's some uh new terminologies uh + + + align:start position:0% +uh that's some uh new terminologies uh +uh actually this was named by the + + align:start position:0% +uh actually this was named by the + + + align:start position:0% +uh actually this was named by the +minister Minister Ministry of + + align:start position:0% +minister Minister Ministry of + + + align:start position:0% +minister Minister Ministry of +information and communication in Korea + + align:start position:0% +information and communication in Korea + + + align:start position:0% +information and communication in Korea +he is Dr Zen he's a pharmacy of Samsung + + align:start position:0% +he is Dr Zen he's a pharmacy of Samsung + + + align:start position:0% +he is Dr Zen he's a pharmacy of Samsung +Electronics i' would like to you know + + align:start position:0% +Electronics i' would like to you know + + + align:start position:0% +Electronics i' would like to you know +the uh Define u sense first and then + + align:start position:0% +the uh Define u sense first and then + + + align:start position:0% +the uh Define u sense first and then +ends and also if is sense net will be + + align:start position:0% +ends and also if is sense net will be + + + align:start position:0% +ends and also if is sense net will be +described Uh u sense Network actually + + align:start position:0% +described Uh u sense Network actually + + + align:start position:0% +described Uh u sense Network actually +you know includes passive AR text and + + align:start position:0% +you know includes passive AR text and + + + align:start position:0% +you know includes passive AR text and +active text and also some sensor text + + align:start position:0% +active text and also some sensor text + + + align:start position:0% +active text and also some sensor text +and the sensor Network so uh actually at + + align:start position:0% +and the sensor Network so uh actually at + + + align:start position:0% +and the sensor Network so uh actually at +you know the we con four different types + + align:start position:0% +you know the we con four different types + + + align:start position:0% +you know the we con four different types +of text the first one is uh EPC you know + + align:start position:0% +of text the first one is uh EPC you know + + + align:start position:0% +of text the first one is uh EPC you know +the passive AR Network as you know text + + align:start position:0% +the passive AR Network as you know text + + + align:start position:0% +the passive AR Network as you know text +readers and all bunches of you know this + + align:start position:0% +readers and all bunches of you know this + + + align:start position:0% +readers and all bunches of you know this +U EP Network middle Wheels uh are for + + align:start position:0% +U EP Network middle Wheels uh are for + + + align:start position:0% +U EP Network middle Wheels uh are for +the EP R Network architect and the + + align:start position:0% +the EP R Network architect and the + + + align:start position:0% +the EP R Network architect and the +second one is active tax we use a + + align:start position:0% +second one is active tax we use a + + + align:start position:0% +second one is active tax we use a +battery to lengthen the radio ranges uh + + align:start position:0% +battery to lengthen the radio ranges uh + + + align:start position:0% +battery to lengthen the radio ranges uh +this is some examples from the company + + align:start position:0% +this is some examples from the company + + + align:start position:0% +this is some examples from the company +Sai you know the using uh app we can uh + + align:start position:0% +Sai you know the using uh app we can uh + + + align:start position:0% +Sai you know the using uh app we can uh +achieve you know the more than 100 m of + + align:start position:0% +achieve you know the more than 100 m of + + + align:start position:0% +achieve you know the more than 100 m of +radio range that's active tax and third + + align:start position:0% +radio range that's active tax and third + + + align:start position:0% +radio range that's active tax and third +one is smart active Rael or a sens tech + + align:start position:0% +one is smart active Rael or a sens tech + + + align:start position:0% +one is smart active Rael or a sens tech +here you know we put uh some batteries + + align:start position:0% +here you know we put uh some batteries + + + align:start position:0% +here you know we put uh some batteries +and also sensors in very you know se you + + align:start position:0% +and also sensors in very you know se you + + + align:start position:0% +and also sensors in very you know se you +know tag so that's a smart active labels + + align:start position:0% +know tag so that's a smart active labels + + + align:start position:0% +know tag so that's a smart active labels +you know there are also semi uh uh smart + + align:start position:0% +you know there are also semi uh uh smart + + + align:start position:0% +you know there are also semi uh uh smart +active labels and smart active ra labels + + align:start position:0% +active labels and smart active ra labels + + + align:start position:0% +active labels and smart active ra labels +in this type and the final one is you + + align:start position:0% +in this type and the final one is you + + + align:start position:0% +in this type and the final one is you +know the sensor uh Network you know the + + align:start position:0% +know the sensor uh Network you know the + + + align:start position:0% +know the sensor uh Network you know the +sensor network is what what network of + + align:start position:0% +sensor network is what what network of + + + align:start position:0% +sensor network is what what network of +sensor no and each sensor no has a + + align:start position:0% +sensor no and each sensor no has a + + + align:start position:0% +sensor no and each sensor no has a +microc contr so it has uh computation uh + + align:start position:0% +microc contr so it has uh computation uh + + + align:start position:0% +microc contr so it has uh computation uh +capabil capabilities and also active wi + + align:start position:0% +capabil capabilities and also active wi + + + align:start position:0% +capabil capabilities and also active wi +risk communication capability and lots + + align:start position:0% +risk communication capability and lots + + + align:start position:0% +risk communication capability and lots +of you know different types of sensors + + align:start position:0% +of you know different types of sensors + + + align:start position:0% +of you know different types of sensors +if they are deployed then they you know + + align:start position:0% +if they are deployed then they you know + + + align:start position:0% +if they are deployed then they you know +the self configure they form adoc + + align:start position:0% +the self configure they form adoc + + + align:start position:0% +the self configure they form adoc +Network right so we can cover some larg + + align:start position:0% +Network right so we can cover some larg + + + align:start position:0% +Network right so we can cover some larg +area larg areas with the sensor + + align:start position:0% +area larg areas with the sensor + + + align:start position:0% +area larg areas with the sensor +Network so uh you know so so far you + + align:start position:0% +Network so uh you know so so far you + + + align:start position:0% +Network so uh you know so so far you +know the there were you know RFI + + align:start position:0% +know the there were you know RFI + + + align:start position:0% +know the there were you know RFI +research Community Development community + + align:start position:0% +research Community Development community + + + align:start position:0% +research Community Development community +and also there are many people are + + align:start position:0% +and also there are many people are + + + align:start position:0% +and also there are many people are +working in sensor Network areas very you + + align:start position:0% +working in sensor Network areas very you + + + align:start position:0% +working in sensor Network areas very you +know hard topics so I think wishing you + + align:start position:0% +know hard topics so I think wishing you + + + align:start position:0% +know hard topics so I think wishing you +know the arip people and sense netor + + align:start position:0% +know the arip people and sense netor + + + align:start position:0% +know the arip people and sense netor +people should meet together and then + + align:start position:0% +people should meet together and then + + + align:start position:0% +people should meet together and then +find you know the more you know the + + align:start position:0% +find you know the more you know the + + + align:start position:0% +find you know the more you know the +different or Advanced you know types of + + align:start position:0% +different or Advanced you know types of + + + align:start position:0% +different or Advanced you know types of +business model so you we could just + + align:start position:0% +business model so you we could just + + + align:start position:0% +business model so you we could just +stand n we Define you know + + align:start position:0% +stand n we Define you know + + + align:start position:0% +stand n we Define you know +the uh actually you can see uh uh in the + + align:start position:0% +the uh actually you can see uh uh in the + + + align:start position:0% +the uh actually you can see uh uh in the +uh right hand side uh we call it uh bcn + + align:start position:0% +uh right hand side uh we call it uh bcn + + + align:start position:0% +uh right hand side uh we call it uh bcn +Broadband converence Network that's just + + align:start position:0% +Broadband converence Network that's just + + + align:start position:0% +Broadband converence Network that's just +some you know highspeed uh internet uh + + align:start position:0% +some you know highspeed uh internet uh + + + align:start position:0% +some you know highspeed uh internet uh +it also include some you know the + + align:start position:0% +it also include some you know the + + + align:start position:0% +it also include some you know the +cellone networks and dmbs network that's + + align:start position:0% +cellone networks and dmbs network that's + + + align:start position:0% +cellone networks and dmbs network that's +some kind of leg network uh we would + + align:start position:0% +some kind of leg network uh we would + + + align:start position:0% +some kind of leg network uh we would +like should you know the include u pive + + align:start position:0% +like should you know the include u pive + + + align:start position:0% +like should you know the include u pive +p active tax and all sensor tax and + + align:start position:0% +p active tax and all sensor tax and + + + align:start position:0% +p active tax and all sensor tax and +sensor Network and then you would like + + align:start position:0% +sensor Network and then you would like + + + align:start position:0% +sensor Network and then you would like +uh make it as some public infrastructure + + align:start position:0% +uh make it as some public infrastructure + + + align:start position:0% +uh make it as some public infrastructure +that's a ous uh + + align:start position:0% +that's a ous uh + + + align:start position:0% +that's a ous uh +netor so uh as s told yesterday you know + + align:start position:0% +netor so uh as s told yesterday you know + + + align:start position:0% +netor so uh as s told yesterday you know +the uh Korean government has some Vision + + align:start position:0% +the uh Korean government has some Vision + + + align:start position:0% +the uh Korean government has some Vision +like + + align:start position:0% +like + + + align:start position:0% +like +it8 39 actually you know the The + + align:start position:0% +it8 39 actually you know the The + + + align:start position:0% +it8 39 actually you know the The +Minister's Cate number is a390 you know + + align:start position:0% +Minister's Cate number is a390 you know + + + align:start position:0% +Minister's Cate number is a390 you know +okay and the vice Minister K is a391 + + align:start position:0% +okay and the vice Minister K is a391 + + + align:start position:0% +okay and the vice Minister K is a391 +something like that you know so the + + align:start position:0% +something like that you know so the + + + align:start position:0% +something like that you know so the +government you know the emphasize you + + align:start position:0% +government you know the emphasize you + + + align:start position:0% +government you know the emphasize you +know the all you know this it39 + + align:start position:0% +know the all you know this it39 + + + align:start position:0% +know the all you know this it39 +strategy and uh we said you know three + + align:start position:0% +strategy and uh we said you know three + + + align:start position:0% +strategy and uh we said you know three +public infrastructure that's a one is a + + align:start position:0% +public infrastructure that's a one is a + + + align:start position:0% +public infrastructure that's a one is a +a Broadband convergence Network and + + align:start position:0% +a Broadband convergence Network and + + + align:start position:0% +a Broadband convergence Network and +second one is this u sense Network + + align:start position:0% +second one is this u sense Network + + + align:start position:0% +second one is this u sense Network +including both passive RFI active Tech + + align:start position:0% +including both passive RFI active Tech + + + align:start position:0% +including both passive RFI active Tech +sense Tech and sense Network and then + + align:start position:0% +sense Tech and sense Network and then + + + align:start position:0% +sense Tech and sense Network and then +the last one is IP version six so that's + + align:start position:0% +the last one is IP version six so that's + + + align:start position:0% +the last one is IP version six so that's +you know the some public infrastructure + + align:start position:0% +you know the some public infrastructure + + + align:start position:0% +you know the some public infrastructure +we would like to build in + + align:start position:0% +we would like to build in + + + align:start position:0% +we would like to build in +career uh I'd like to you know the + + align:start position:0% +career uh I'd like to you know the + + + align:start position:0% +career uh I'd like to you know the +person introduce uh uh my uh current + + align:start position:0% +person introduce uh uh my uh current + + + align:start position:0% +person introduce uh uh my uh current +project that's a that's for public + + align:start position:0% +project that's a that's for public + + + align:start position:0% +project that's a that's for public +sensor networks you know uh sensor + + align:start position:0% +sensor networks you know uh sensor + + + align:start position:0% +sensor networks you know uh sensor +network is as I said very you know the + + align:start position:0% +network is as I said very you know the + + + align:start position:0% +network is as I said very you know the +popular you know the uh uh areas and + + align:start position:0% +popular you know the uh uh areas and + + + align:start position:0% +popular you know the uh uh areas and +there are many people are working on it + + align:start position:0% +there are many people are working on it + + + align:start position:0% +there are many people are working on it +uh when I started this project for years + + align:start position:0% +uh when I started this project for years + + + align:start position:0% +uh when I started this project for years +ago you know I set some uh theme you + + align:start position:0% +ago you know I set some uh theme you + + + align:start position:0% +ago you know I set some uh theme you +know that's a evolvability you know uh I + + align:start position:0% +know that's a evolvability you know uh I + + + align:start position:0% +know that's a evolvability you know uh I +IV Vision that you know the uh in the + + align:start position:0% +IV Vision that you know the uh in the + + + align:start position:0% +IV Vision that you know the uh in the +future sense network uh we also you know + + align:start position:0% +future sense network uh we also you know + + + align:start position:0% +future sense network uh we also you know +the populate the globe you know like uh + + align:start position:0% +the populate the globe you know like uh + + + align:start position:0% +the populate the globe you know like uh +currently internet does today so so the + + align:start position:0% +currently internet does today so so the + + + align:start position:0% +currently internet does today so so the +sense Network there there will be many + + align:start position:0% +sense Network there there will be many + + + align:start position:0% +sense Network there there will be many +you know the sense notes like there will + + align:start position:0% +you know the sense notes like there will + + + align:start position:0% +you know the sense notes like there will +be many ADI text in the world so uh the + + align:start position:0% +be many ADI text in the world so uh the + + + align:start position:0% +be many ADI text in the world so uh the +lifetime of a sense netor will be also + + align:start position:0% +lifetime of a sense netor will be also + + + align:start position:0% +lifetime of a sense netor will be also +very long 5 years 10 years 20 years who + + align:start position:0% +very long 5 years 10 years 20 years who + + + align:start position:0% +very long 5 years 10 years 20 years who +knows right so uh uh after they are + + align:start position:0% +knows right so uh uh after they are + + + align:start position:0% +knows right so uh uh after they are +deployed then uh they will evolve you + + align:start position:0% +deployed then uh they will evolve you + + + align:start position:0% +deployed then uh they will evolve you +know sometimes for example the mission + + align:start position:0% +know sometimes for example the mission + + + align:start position:0% +know sometimes for example the mission +is changed so we have to uh update the + + align:start position:0% +is changed so we have to uh update the + + + align:start position:0% +is changed so we have to uh update the +mission or some Network even you know + + align:start position:0% +mission or some Network even you know + + + align:start position:0% +mission or some Network even you know +the network protocols and some you know + + align:start position:0% +the network protocols and some you know + + + align:start position:0% +the network protocols and some you know +the key components also can be changed + + align:start position:0% +the key components also can be changed + + + align:start position:0% +the key components also can be changed +so so uh so all the components of sensor + + align:start position:0% +so so uh so all the components of sensor + + + align:start position:0% +so so uh so all the components of sensor +network from Hardware operating system + + align:start position:0% +network from Hardware operating system + + + align:start position:0% +network from Hardware operating system +and network protocols even you know the + + align:start position:0% +and network protocols even you know the + + + align:start position:0% +and network protocols even you know the +some location sensing protocol should + + align:start position:0% +some location sensing protocol should + + + align:start position:0% +some location sensing protocol should +have a capability of some Evol ability + + align:start position:0% +have a capability of some Evol ability + + + align:start position:0% +have a capability of some Evol ability +so to do that uh we have developed uh + + align:start position:0% +so to do that uh we have developed uh + + + align:start position:0% +so to do that uh we have developed uh +and you know the hardware and software + + align:start position:0% +and you know the hardware and software + + + align:start position:0% +and you know the hardware and software +platform you know those are Hardwares + + align:start position:0% +platform you know those are Hardwares + + + align:start position:0% +platform you know those are Hardwares +and softwares maybe you know the + + align:start position:0% +and softwares maybe you know the + + + align:start position:0% +and softwares maybe you know the +similarly EPC class 4 Tech may have you + + align:start position:0% +similarly EPC class 4 Tech may have you + + + align:start position:0% +similarly EPC class 4 Tech may have you +know this kind of a software inside from + + align:start position:0% +know this kind of a software inside from + + + align:start position:0% +know this kind of a software inside from +the bottom actually we have four types + + align:start position:0% +the bottom actually we have four types + + + align:start position:0% +the bottom actually we have four types +of Hardwares the H1 is a very small sens + + align:start position:0% +of Hardwares the H1 is a very small sens + + + align:start position:0% +of Hardwares the H1 is a very small sens +no it can be attached to the switches or + + align:start position:0% +no it can be attached to the switches or + + + align:start position:0% +no it can be attached to the switches or +some uh light you know and H2 is a more + + align:start position:0% +some uh light you know and H2 is a more + + + align:start position:0% +some uh light you know and H2 is a more +advanced you know the Sens no it's it's + + align:start position:0% +advanced you know the Sens no it's it's + + + align:start position:0% +advanced you know the Sens no it's it's +very similar to you know the bual is on + + align:start position:0% +very similar to you know the bual is on + + + align:start position:0% +very similar to you know the bual is on +mic 3 Moto 3 and H3 is a uh actually + + align:start position:0% +mic 3 Moto 3 and H3 is a uh actually + + + align:start position:0% +mic 3 Moto 3 and H3 is a uh actually +more advanced you know the sensor node + + align:start position:0% +more advanced you know the sensor node + + + align:start position:0% +more advanced you know the sensor node +it has sensors like CCD cameras and + + align:start position:0% +it has sensors like CCD cameras and + + + align:start position:0% +it has sensors like CCD cameras and +something like that and also it can have + + align:start position:0% +something like that and also it can have + + + align:start position:0% +something like that and also it can have +some image processing capability inside + + align:start position:0% +some image processing capability inside + + + align:start position:0% +some image processing capability inside +and H4 is a uh some Bas station and + + align:start position:0% +and H4 is a uh some Bas station and + + + align:start position:0% +and H4 is a uh some Bas station and +gateway to the Legacy Network it can be + + align:start position:0% +gateway to the Legacy Network it can be + + + align:start position:0% +gateway to the Legacy Network it can be +uh compared to the AR leader in our EPC + + align:start position:0% +uh compared to the AR leader in our EPC + + + align:start position:0% +uh compared to the AR leader in our EPC +Network above the hard layers so we have + + align:start position:0% +Network above the hard layers so we have + + + align:start position:0% +Network above the hard layers so we have +operating systems and uh several + + align:start position:0% +operating systems and uh several + + + align:start position:0% +operating systems and uh several +different types of you know nwork stack + + align:start position:0% +different types of you know nwork stack + + + align:start position:0% +different types of you know nwork stack +including Max and net Rayas and also + + align:start position:0% +including Max and net Rayas and also + + + align:start position:0% +including Max and net Rayas and also +Securities and the time synchronization + + align:start position:0% +Securities and the time synchronization + + + align:start position:0% +Securities and the time synchronization +protols and also location sensing + + align:start position:0% +protols and also location sensing + + + align:start position:0% +protols and also location sensing +algorithms and power management and also + + align:start position:0% +algorithms and power management and also + + + align:start position:0% +algorithms and power management and also +some uh middle Wheels that's the + + align:start position:0% +some uh middle Wheels that's the + + + align:start position:0% +some uh middle Wheels that's the +platform we have using uh this platform + + align:start position:0% +platform we have using uh this platform + + + align:start position:0% +platform we have using uh this platform +uh uh we have uh prototyped some systems + + align:start position:0% +uh uh we have uh prototyped some systems + + + align:start position:0% +uh uh we have uh prototyped some systems +like some military reconnaissance system + + align:start position:0% +like some military reconnaissance system + + + align:start position:0% +like some military reconnaissance system +using aanda helicopters and also you use + + align:start position:0% +using aanda helicopters and also you use + + + align:start position:0% +using aanda helicopters and also you use +you know sens n in the greenhouse + + align:start position:0% +you know sens n in the greenhouse + + + align:start position:0% +you know sens n in the greenhouse +something like that this is a the uh + + align:start position:0% +something like that this is a the uh + + + align:start position:0% +something like that this is a the uh +current you know project what I'm + + align:start position:0% +current you know project what I'm + + + align:start position:0% +current you know project what I'm +carrying out in + + align:start position:0% +carrying out in + + + align:start position:0% +carrying out in +Korea uh uh if you you know the P Korea + + align:start position:0% +Korea uh uh if you you know the P Korea + + + align:start position:0% +Korea uh uh if you you know the P Korea +uh actually this is the South Korea and + + align:start position:0% +uh actually this is the South Korea and + + + align:start position:0% +uh actually this is the South Korea and +then uh in southernmost area we have + + align:start position:0% +then uh in southernmost area we have + + + align:start position:0% +then uh in southernmost area we have +some big you know the Fantastic Island + + align:start position:0% +some big you know the Fantastic Island + + + align:start position:0% +some big you know the Fantastic Island +uh it is called jzu Island uh we have a + + align:start position:0% +uh it is called jzu Island uh we have a + + + align:start position:0% +uh it is called jzu Island uh we have a +you know the the highest mountain in JZ + + align:start position:0% +you know the the highest mountain in JZ + + + align:start position:0% +you know the the highest mountain in JZ +Island in Korea is almost 2 kilometers + + align:start position:0% +Island in Korea is almost 2 kilometers + + + align:start position:0% +Island in Korea is almost 2 kilometers +high now we are deploying you know + + align:start position:0% +high now we are deploying you know + + + align:start position:0% +high now we are deploying you know +sensor networks in the trail of you know + + align:start position:0% +sensor networks in the trail of you know + + + align:start position:0% +sensor networks in the trail of you know +this mountain Hala Mountain uh actually + + align:start position:0% +this mountain Hala Mountain uh actually + + + align:start position:0% +this mountain Hala Mountain uh actually +it has four trads among four we choose + + align:start position:0% +it has four trads among four we choose + + + align:start position:0% +it has four trads among four we choose +two one is 4.7 kilm long the other one + + align:start position:0% +two one is 4.7 kilm long the other one + + + align:start position:0% +two one is 4.7 kilm long the other one +is 3.1 kilm long so we deploy sensors + + align:start position:0% +is 3.1 kilm long so we deploy sensors + + + align:start position:0% +is 3.1 kilm long so we deploy sensors +every 100 m in some areas every 250 M + + align:start position:0% +every 100 m in some areas every 250 M + + + align:start position:0% +every 100 m in some areas every 250 M +and then we collected uh the you know + + align:start position:0% +and then we collected uh the you know + + + align:start position:0% +and then we collected uh the you know +the weather information in in real time + + align:start position:0% +the weather information in in real time + + + align:start position:0% +the weather information in in real time +and then we uh actually that collected + + align:start position:0% +and then we uh actually that collected + + + align:start position:0% +and then we uh actually that collected +information will be forwarded to the my + + align:start position:0% +information will be forwarded to the my + + + align:start position:0% +information will be forwarded to the my +University actually it's a 500 + + align:start position:0% +University actually it's a 500 + + + align:start position:0% +University actually it's a 500 +kilometers away from you know the this + + align:start position:0% +kilometers away from you know the this + + + align:start position:0% +kilometers away from you know the this +mountain and then this collected + + align:start position:0% +mountain and then this collected + + + align:start position:0% +mountain and then this collected +information uh uh is going to be + + align:start position:0% +information uh uh is going to be + + + align:start position:0% +information uh uh is going to be +delivered to the uh some climbers you + + align:start position:0% +delivered to the uh some climbers you + + + align:start position:0% +delivered to the uh some climbers you +know climber who carries cellone okay so + + align:start position:0% +know climber who carries cellone okay so + + + align:start position:0% +know climber who carries cellone okay so +uh they can browse the weather + + align:start position:0% +uh they can browse the weather + + + align:start position:0% +uh they can browse the weather +information uh in the trail you know + + align:start position:0% +information uh in the trail you know + + + align:start position:0% +information uh in the trail you know +actually you know the because this is + + align:start position:0% +actually you know the because this is + + + align:start position:0% +actually you know the because this is +two Kil two k high mountain you know the + + align:start position:0% +two Kil two k high mountain you know the + + + align:start position:0% +two Kil two k high mountain you know the +weather varies a lot you know when we go + + align:start position:0% +weather varies a lot you know when we go + + + align:start position:0% +weather varies a lot you know when we go +to the mountain to test uh in the in the + + align:start position:0% +to the mountain to test uh in the in the + + + align:start position:0% +to the mountain to test uh in the in the +you know the circle uh we see the + + align:start position:0% +you know the circle uh we see the + + + align:start position:0% +you know the circle uh we see the +mountain then it looks like a Lany okay + + align:start position:0% +mountain then it looks like a Lany okay + + + align:start position:0% +mountain then it looks like a Lany okay +and then uh I ask a student to buy Lane + + align:start position:0% +and then uh I ask a student to buy Lane + + + align:start position:0% +and then uh I ask a student to buy Lane +cat and I climbed then you know at that + + align:start position:0% +cat and I climbed then you know at that + + + align:start position:0% +cat and I climbed then you know at that +time you know uh actually my pace and + + align:start position:0% +time you know uh actually my pace and + + + align:start position:0% +time you know uh actually my pace and +arm are all burned you know so you know + + align:start position:0% +arm are all burned you know so you know + + + align:start position:0% +arm are all burned you know so you know +the weather is you know + + align:start position:0% +the weather is you know + + + align:start position:0% +the weather is you know +verying and even you know I uh arrived + + align:start position:0% +verying and even you know I uh arrived + + + align:start position:0% +verying and even you know I uh arrived +at p and then I saw people wept you know + + align:start position:0% +at p and then I saw people wept you know + + + align:start position:0% +at p and then I saw people wept you know +they took another you know the trail so + + align:start position:0% +they took another you know the trail so + + + align:start position:0% +they took another you know the trail so +this is very important for the climat so + + align:start position:0% +this is very important for the climat so + + + align:start position:0% +this is very important for the climat so +this is a one of our you know sensor n + + align:start position:0% +this is a one of our you know sensor n + + + align:start position:0% +this is a one of our you know sensor n +products so uh this is some you know the + + align:start position:0% +products so uh this is some you know the + + + align:start position:0% +products so uh this is some you know the +pictures I have taken in the trial and + + align:start position:0% +pictures I have taken in the trial and + + + align:start position:0% +pictures I have taken in the trial and +uh this is currently installed in the uh + + align:start position:0% +uh this is currently installed in the uh + + + align:start position:0% +uh this is currently installed in the uh +Mountain actually still we are in the + + align:start position:0% +Mountain actually still we are in the + + + align:start position:0% +Mountain actually still we are in the +development and the + + align:start position:0% +development and the + + + align:start position:0% +development and the +test and uh so that's that's that's for + + align:start position:0% +test and uh so that's that's that's for + + + align:start position:0% +test and uh so that's that's that's for +the you know the public U sens Network + + align:start position:0% +the you know the public U sens Network + + + align:start position:0% +the you know the public U sens Network +actually uh I'm I'm the chair of uh + + align:start position:0% +actually uh I'm I'm the chair of uh + + + align:start position:0% +actually uh I'm I'm the chair of uh +Korean national standards committee for + + align:start position:0% +Korean national standards committee for + + + align:start position:0% +Korean national standards committee for +the public U sensor Network you know so + + align:start position:0% +the public U sensor Network you know so + + + align:start position:0% +the public U sensor Network you know so +we are trying to you know the + + align:start position:0% +we are trying to you know the + + + align:start position:0% +we are trying to you know the +standardize networ protocols uh and also + + align:start position:0% +standardize networ protocols uh and also + + + align:start position:0% +standardize networ protocols uh and also +Network management protocol and + + align:start position:0% +Network management protocol and + + + align:start position:0% +Network management protocol and +something like that and then uh actually + + align:start position:0% +something like that and then uh actually + + + align:start position:0% +something like that and then uh actually +uh we joined auts you know the last + + align:start position:0% +uh we joined auts you know the last + + + align:start position:0% +uh we joined auts you know the last +April and then we Lear you know the + + align:start position:0% +April and then we Lear you know the + + + align:start position:0% +April and then we Lear you know the +other part stops and then there are also + + align:start position:0% +other part stops and then there are also + + + align:start position:0% +other part stops and then there are also +very interesting topics here you know uh + + align:start position:0% +very interesting topics here you know uh + + + align:start position:0% +very interesting topics here you know uh +actually this is maybe drawn by Elga you + + align:start position:0% +actually this is maybe drawn by Elga you + + + align:start position:0% +actually this is maybe drawn by Elga you +know the uh so uh Auto IDs have you know + + align:start position:0% +know the uh so uh Auto IDs have you know + + + align:start position:0% +know the uh so uh Auto IDs have you know +the three different uh research you know + + align:start position:0% +the three different uh research you know + + + align:start position:0% +the three different uh research you know +the categories from bottom RF and Chip + + align:start position:0% +the categories from bottom RF and Chip + + + align:start position:0% +the categories from bottom RF and Chip +design including uh EP class 1 2 3 4 and + + align:start position:0% +design including uh EP class 1 2 3 4 and + + + align:start position:0% +design including uh EP class 1 2 3 4 and +five and networking and software and uh + + align:start position:0% +five and networking and software and uh + + + align:start position:0% +five and networking and software and uh +business and application also you know + + align:start position:0% +business and application also you know + + + align:start position:0% +business and application also you know +the privacy and security actually we + + align:start position:0% +the privacy and security actually we + + + align:start position:0% +the privacy and security actually we +have interested in + + align:start position:0% +have interested in + + + align:start position:0% +have interested in +uh EPC uh class four okay so maybe EPC + + align:start position:0% +uh EPC uh class four okay so maybe EPC + + + align:start position:0% +uh EPC uh class four okay so maybe EPC +class one in G to a interface three may + + align:start position:0% +class one in G to a interface three may + + + align:start position:0% +class one in G to a interface three may +use the you know the same interface + + align:start position:0% +use the you know the same interface + + + align:start position:0% +use the you know the same interface +interface three actually I don't know + + align:start position:0% +interface three actually I don't know + + + align:start position:0% +interface three actually I don't know +maybe four four the interace should be + + align:start position:0% +maybe four four the interace should be + + + align:start position:0% +maybe four four the interace should be +changed you know we need a Mac protocol + + align:start position:0% +changed you know we need a Mac protocol + + + align:start position:0% +changed you know we need a Mac protocol +and also we need you know addon net + + align:start position:0% +and also we need you know addon net + + + align:start position:0% +and also we need you know addon net +protocol so we have interested in and we + + align:start position:0% +protocol so we have interested in and we + + + align:start position:0% +protocol so we have interested in and we +also you know the analyzed the you know + + align:start position:0% +also you know the analyzed the you know + + + align:start position:0% +also you know the analyzed the you know +sens that EP netork middle you + + align:start position:0% +sens that EP netork middle you + + + align:start position:0% +sens that EP netork middle you +know uh to include okay sorry to include + + align:start position:0% +know uh to include okay sorry to include + + + align:start position:0% +know uh to include okay sorry to include +you know sensor text and the sensor + + align:start position:0% +you know sensor text and the sensor + + + align:start position:0% +you know sensor text and the sensor +Network you know the also the middleware + + align:start position:0% +Network you know the also the middleware + + + align:start position:0% +Network you know the also the middleware +maybe should be you know the change it + + align:start position:0% +maybe should be you know the change it + + + align:start position:0% +maybe should be you know the change it +mod modified and added and something + + align:start position:0% +mod modified and added and something + + + align:start position:0% +mod modified and added and something +like that for example uh uh a uh and the + + align:start position:0% +like that for example uh uh a uh and the + + + align:start position:0% +like that for example uh uh a uh and the +Le protocol it has some filtering + + align:start position:0% +Le protocol it has some filtering + + + align:start position:0% +Le protocol it has some filtering +capabilities right so it can filter out + + align:start position:0% +capabilities right so it can filter out + + + align:start position:0% +capabilities right so it can filter out +some specific uh EP + + align:start position:0% +some specific uh EP + + + align:start position:0% +some specific uh EP +uh same you know the for example if we + + align:start position:0% +uh same you know the for example if we + + + align:start position:0% +uh same you know the for example if we +include sensors then we can also + + align:start position:0% +include sensors then we can also + + + align:start position:0% +include sensors then we can also +filtering out some uh data which has you + + align:start position:0% +filtering out some uh data which has you + + + align:start position:0% +filtering out some uh data which has you +know sense value within some range + + align:start position:0% +know sense value within some range + + + align:start position:0% +know sense value within some range +something like that so filtering uh also + + align:start position:0% +something like that so filtering uh also + + + align:start position:0% +something like that so filtering uh also +epis repository to we have to + + align:start position:0% +epis repository to we have to + + + align:start position:0% +epis repository to we have to +accommodate you know sensor information + + align:start position:0% +accommodate you know sensor information + + + align:start position:0% +accommodate you know sensor information +and epis Discovery you also have to use + + align:start position:0% +and epis Discovery you also have to use + + + align:start position:0% +and epis Discovery you also have to use +you know the sensor value you know for + + align:start position:0% +you know the sensor value you know for + + + align:start position:0% +you know the sensor value you know for +the discovery something like that so uh + + align:start position:0% +the discovery something like that so uh + + + align:start position:0% +the discovery something like that so uh +I think this is also very uh great + + align:start position:0% +I think this is also very uh great + + + align:start position:0% +I think this is also very uh great +challenge you know so uh this is the + + align:start position:0% +challenge you know so uh this is the + + + align:start position:0% +challenge you know so uh this is the +proposal you know I'd like to propose in + + align:start position:0% +proposal you know I'd like to propose in + + + align:start position:0% +proposal you know I'd like to propose in +uh this iFish Global Community okay + + align:start position:0% +uh this iFish Global Community okay + + + align:start position:0% +uh this iFish Global Community okay +thank you very + + align:start position:0% +thank you very + + + align:start position:0% +thank you very +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +much so so by the way the the the title + + align:start position:0% +much so so by the way the the the title + + + align:start position:0% +much so so by the way the the the title +of this session is is beyond the supply + + align:start position:0% +of this session is is beyond the supply + + + align:start position:0% +of this session is is beyond the supply +chain right so we talked about some of + + align:start position:0% +chain right so we talked about some of + + + align:start position:0% +chain right so we talked about some of +the range of applications down into the + + align:start position:0% +the range of applications down into the + + + align:start position:0% +the range of applications down into the +coal mines in China and then and then in + + align:start position:0% +coal mines in China and then and then in + + + align:start position:0% +coal mines in China and then and then in +Europe uh and uh up in the mountains of + + align:start position:0% +Europe uh and uh up in the mountains of + + + align:start position:0% +Europe uh and uh up in the mountains of +hanaro uh and and now we're privileged + + align:start position:0% +hanaro uh and and now we're privileged + + + align:start position:0% +hanaro uh and and now we're privileged +to have + + align:start position:0% +to have + + + align:start position:0% +to have +um J Yong who is the emerging business + + align:start position:0% +um J Yong who is the emerging business + + + align:start position:0% +um J Yong who is the emerging business +incubation manager of the technology + + align:start position:0% +incubation manager of the technology + + + align:start position:0% +incubation manager of the technology +strategy office of SK Telecom uh in in + + align:start position:0% +strategy office of SK Telecom uh in in + + + align:start position:0% +strategy office of SK Telecom uh in in +Korea uh who will share with us how how + + align:start position:0% +Korea uh who will share with us how how + + + align:start position:0% +Korea uh who will share with us how how +they're extending RFID into the network + + align:start position:0% +they're extending RFID into the network + + + align:start position:0% +they're extending RFID into the network +thank you + + align:start position:0% + + + + align:start position:0% + +uh good afternoon uh gentlemen uh I am + + align:start position:0% +uh good afternoon uh gentlemen uh I am + + + align:start position:0% +uh good afternoon uh gentlemen uh I am +Jun from SK Telecom which has about 18 + + align:start position:0% +Jun from SK Telecom which has about 18 + + + align:start position:0% +Jun from SK Telecom which has about 18 +million mobile subscribers in Korea + + align:start position:0% +million mobile subscribers in Korea + + + align:start position:0% +million mobile subscribers in Korea +today I would like to introduced the + + align:start position:0% +today I would like to introduced the + + + align:start position:0% +today I would like to introduced the +mobile applications for RFID technology + + align:start position:0% +mobile applications for RFID technology + + + align:start position:0% +mobile applications for RFID technology +currently planned by SK + + align:start position:0% +currently planned by SK + + + align:start position:0% +currently planned by SK +Telecom first of all let me briefly + + align:start position:0% +Telecom first of all let me briefly + + + align:start position:0% +Telecom first of all let me briefly +introduce SK Telcom to + + align:start position:0% + + + + align:start position:0% + +you es Telecom uh since its foundation + + align:start position:0% +you es Telecom uh since its foundation + + + align:start position:0% +you es Telecom uh since its foundation +in + + align:start position:0% +in + + + align:start position:0% +in +1984 has been providing mobile + + align:start position:0% +1984 has been providing mobile + + + align:start position:0% +1984 has been providing mobile +Communication Service in Korea over 20 + + align:start position:0% +Communication Service in Korea over 20 + + + align:start position:0% +Communication Service in Korea over 20 +years we commercialize the CDMA network + + align:start position:0% +years we commercialize the CDMA network + + + align:start position:0% +years we commercialize the CDMA network +in + + align:start position:0% +in + + + align:start position:0% +in +1996 for the first time in the + + align:start position:0% +1996 for the first time in the + + + align:start position:0% +1996 for the first time in the +world uh skel wireless internet services + + align:start position:0% +world uh skel wireless internet services + + + align:start position:0% +world uh skel wireless internet services +are oped in two Brands Nate and + + align:start position:0% +are oped in two Brands Nate and + + + align:start position:0% +are oped in two Brands Nate and +June Nate is General wireless internet + + align:start position:0% +June Nate is General wireless internet + + + align:start position:0% +June Nate is General wireless internet +service whereas June is a multimedia + + align:start position:0% +service whereas June is a multimedia + + + align:start position:0% +service whereas June is a multimedia +service based on CDMA EV video Network + + align:start position:0% +service based on CDMA EV video Network + + + align:start position:0% +service based on CDMA EV video Network +Technology s telecom's wireless internet + + align:start position:0% +Technology s telecom's wireless internet + + + align:start position:0% +Technology s telecom's wireless internet +services loed on approximate + + align:start position:0% +services loed on approximate + + + align:start position:0% +services loed on approximate +record of 1.7 billion US + + align:start position:0% +record of 1.7 billion US + + + align:start position:0% +record of 1.7 billion US +dollar the wireless internet service + + align:start position:0% +dollar the wireless internet service + + + align:start position:0% +dollar the wireless internet service +took up + + align:start position:0% +took up + + + align:start position:0% +took up +20.6% of SK telecoms entire Revenue + + align:start position:0% +20.6% of SK telecoms entire Revenue + + + align:start position:0% +20.6% of SK telecoms entire Revenue +which increased by threefold in the last + + align:start position:0% +which increased by threefold in the last + + + align:start position:0% +which increased by threefold in the last + + align:start position:0% + + + align:start position:0% +years the current growth momentum is + + align:start position:0% +years the current growth momentum is + + + align:start position:0% +years the current growth momentum is +expected to continue but Korean mobile + + align:start position:0% +expected to continue but Korean mobile + + + align:start position:0% +expected to continue but Korean mobile +market is fast getting + + align:start position:0% +market is fast getting + + + align:start position:0% +market is fast getting +saturated we must develop new grow + + align:start position:0% +saturated we must develop new grow + + + align:start position:0% +saturated we must develop new grow +opportunity now and we think the mobile + + align:start position:0% +opportunity now and we think the mobile + + + align:start position:0% +opportunity now and we think the mobile +RFID application will be one of gross + + align:start position:0% + + + + align:start position:0% + +engine we think we have found one + + align:start position:0% +engine we think we have found one + + + align:start position:0% +engine we think we have found one +solution that is U quter service based + + align:start position:0% +solution that is U quter service based + + + align:start position:0% +solution that is U quter service based +on + + align:start position:0% +on + + + align:start position:0% +on +convergence our customers desire + + align:start position:0% +convergence our customers desire + + + align:start position:0% +convergence our customers desire +personalized customized services and + + align:start position:0% +personalized customized services and + + + align:start position:0% +personalized customized services and +more userfriendly devices + + align:start position:0% +more userfriendly devices + + + align:start position:0% +more userfriendly devices +such customer needs will spell an + + align:start position:0% +such customer needs will spell an + + + align:start position:0% +such customer needs will spell an +opportunity for operators to use as a + + align:start position:0% +opportunity for operators to use as a + + + align:start position:0% +opportunity for operators to use as a +new gross + + align:start position:0% +new gross + + + align:start position:0% +new gross +engine this trend will be further + + align:start position:0% +engine this trend will be further + + + align:start position:0% +engine this trend will be further +accelerated by the interactions between + + align:start position:0% +accelerated by the interactions between + + + align:start position:0% +accelerated by the interactions between +drivers of + + align:start position:0% +drivers of + + + align:start position:0% +drivers of +convergence while the convergence Trend + + align:start position:0% +convergence while the convergence Trend + + + align:start position:0% +convergence while the convergence Trend +will present both opportunities and + + align:start position:0% +will present both opportunities and + + + align:start position:0% +will present both opportunities and +treats to Telecom operators it will + + align:start position:0% +treats to Telecom operators it will + + + align:start position:0% +treats to Telecom operators it will +undoubtedly bring about much enhanced + + align:start position:0% +undoubtedly bring about much enhanced + + + align:start position:0% +undoubtedly bring about much enhanced +value values to our customer + + align:start position:0% + + + + align:start position:0% + +I will explain the bus strategy of es + + align:start position:0% +I will explain the bus strategy of es + + + align:start position:0% +I will explain the bus strategy of es +Telecom as you can see in the chart on + + align:start position:0% +Telecom as you can see in the chart on + + + align:start position:0% +Telecom as you can see in the chart on +the left es Telecom has recognized the + + align:start position:0% +the left es Telecom has recognized the + + + align:start position:0% +the left es Telecom has recognized the +convergence business as a new grow + + align:start position:0% +convergence business as a new grow + + + align:start position:0% +convergence business as a new grow +opportunity and is now stepping up its + + align:start position:0% +opportunity and is now stepping up its + + + align:start position:0% +opportunity and is now stepping up its +effort to find new business + + align:start position:0% +effort to find new business + + + align:start position:0% +effort to find new business +models so far we have presence in + + align:start position:0% +models so far we have presence in + + + align:start position:0% +models so far we have presence in +broadcasting Finance and commerce + + align:start position:0% +broadcasting Finance and commerce + + + align:start position:0% +broadcasting Finance and commerce +content distribution fixed line services + + align:start position:0% +content distribution fixed line services + + + align:start position:0% +content distribution fixed line services +and hands and Manufacturing + + align:start position:0% +and hands and Manufacturing + + + align:start position:0% +and hands and Manufacturing +businesses in the future we plan to + + align:start position:0% +businesses in the future we plan to + + + align:start position:0% +businesses in the future we plan to +expand our business into telematics and + + align:start position:0% +expand our business into telematics and + + + align:start position:0% +expand our business into telematics and +RFID terminals equipped with our DMB + + align:start position:0% +RFID terminals equipped with our DMB + + + align:start position:0% +RFID terminals equipped with our DMB +finance and buil-in cameras are sold on + + align:start position:0% +finance and buil-in cameras are sold on + + + align:start position:0% +finance and buil-in cameras are sold on +the market today and the terminal + + align:start position:0% +the market today and the terminal + + + align:start position:0% +the market today and the terminal +equiped RFI leer will be introduced by + + align:start position:0% +equiped RFI leer will be introduced by + + + align:start position:0% +equiped RFI leer will be introduced by +this year + + align:start position:0% + + + + align:start position:0% + +next I will explain the ucg scenario of + + align:start position:0% +next I will explain the ucg scenario of + + + align:start position:0% +next I will explain the ucg scenario of +physical mobile RI + + align:start position:0% +physical mobile RI + + + align:start position:0% +physical mobile RI +application first the user scans the ri + + align:start position:0% +application first the user scans the ri + + + align:start position:0% +application first the user scans the ri +tag with the mobile terminal this result + + align:start position:0% +tag with the mobile terminal this result + + + align:start position:0% +tag with the mobile terminal this result +in the RFI + + align:start position:0% +in the RFI + + + align:start position:0% +in the RFI +code being transform transferred from + + align:start position:0% +code being transform transferred from + + + align:start position:0% +code being transform transferred from +the tag to the mobile terminal the + + align:start position:0% +the tag to the mobile terminal the + + + align:start position:0% +the tag to the mobile terminal the +mobile terminal access the mobile + + align:start position:0% +mobile terminal access the mobile + + + align:start position:0% +mobile terminal access the mobile +network and ask the user to select the + + align:start position:0% +network and ask the user to select the + + + align:start position:0% +network and ask the user to select the +RFI service RFI service then directs + + align:start position:0% +RFI service RFI service then directs + + + align:start position:0% +RFI service RFI service then directs +request for information to the RFID + + align:start position:0% +request for information to the RFID + + + align:start position:0% +request for information to the RFID +service platform consisting of object + + align:start position:0% +service platform consisting of object + + + align:start position:0% +service platform consisting of object +directory server object tability server + + align:start position:0% +directory server object tability server + + + align:start position:0% +directory server object tability server +and object information + + align:start position:0% +and object information + + + align:start position:0% +and object information +server these servers contain the + + align:start position:0% +server these servers contain the + + + align:start position:0% +server these servers contain the +necessary information about tagged + + align:start position:0% +necessary information about tagged + + + align:start position:0% +necessary information about tagged +object from Simple Text information to + + align:start position:0% +object from Simple Text information to + + + align:start position:0% +object from Simple Text information to +audio video content + + align:start position:0% +audio video content + + + align:start position:0% +audio video content +this information is sent back to the + + align:start position:0% +this information is sent back to the + + + align:start position:0% +this information is sent back to the +mobile terminal the user consumes this + + align:start position:0% +mobile terminal the user consumes this + + + align:start position:0% +mobile terminal the user consumes this +information and then the mobile terminal + + align:start position:0% +information and then the mobile terminal + + + align:start position:0% +information and then the mobile terminal +will send building information to the + + align:start position:0% +will send building information to the + + + align:start position:0% +will send building information to the +mobile network + + align:start position:0% + + + + align:start position:0% + +operator future many kind senses will be + + align:start position:0% +operator future many kind senses will be + + + align:start position:0% +operator future many kind senses will be +applied to various plac to sensing the + + align:start position:0% +applied to various plac to sensing the + + + align:start position:0% +applied to various plac to sensing the +environment condition which information + + align:start position:0% +environment condition which information + + + align:start position:0% +environment condition which information +transmit and to data managing equipment + + align:start position:0% +transmit and to data managing equipment + + + align:start position:0% +transmit and to data managing equipment +through mobile l Network infra we call + + align:start position:0% +through mobile l Network infra we call + + + align:start position:0% +through mobile l Network infra we call +it us environment which has the + + align:start position:0% +it us environment which has the + + + align:start position:0% +it us environment which has the +tremendous mobile business chance now we + + align:start position:0% +tremendous mobile business chance now we + + + align:start position:0% +tremendous mobile business chance now we +are trying to make new kind service with + + align:start position:0% +are trying to make new kind service with + + + align:start position:0% +are trying to make new kind service with +a mobile phone with has RI leader chip + + align:start position:0% +a mobile phone with has RI leader chip + + + align:start position:0% +a mobile phone with has RI leader chip +inside this is the main concept of + + align:start position:0% +inside this is the main concept of + + + align:start position:0% +inside this is the main concept of +mobile I service or technology with + + align:start position:0% +mobile I service or technology with + + + align:start position:0% +mobile I service or technology with +convergence between mobile phone and + + align:start position:0% + + + + align:start position:0% + +RFID mobile II technology is a wireless + + align:start position:0% +RFID mobile II technology is a wireless + + + align:start position:0% +RFID mobile II technology is a wireless +technology that provides new valuable + + align:start position:0% +technology that provides new valuable + + + align:start position:0% +technology that provides new valuable +service to customers by integrating RFID + + align:start position:0% +service to customers by integrating RFID + + + align:start position:0% +service to customers by integrating RFID +infrastructure with mobile communication + + align:start position:0% +infrastructure with mobile communication + + + align:start position:0% +infrastructure with mobile communication +and wireless internet we hope mobile + + align:start position:0% +and wireless internet we hope mobile + + + align:start position:0% +and wireless internet we hope mobile +RFID technology and the service would + + align:start position:0% +RFID technology and the service would + + + align:start position:0% +RFID technology and the service would +bring these four conditions first one is + + align:start position:0% +bring these four conditions first one is + + + align:start position:0% +bring these four conditions first one is +creating new value for mobile phone + + align:start position:0% +creating new value for mobile phone + + + align:start position:0% +creating new value for mobile phone +users second one is building new markets + + align:start position:0% +users second one is building new markets + + + align:start position:0% +users second one is building new markets +third one is improving quality of uus + + align:start position:0% +third one is improving quality of uus + + + align:start position:0% +third one is improving quality of uus +life and the last one is developing and + + align:start position:0% +life and the last one is developing and + + + align:start position:0% +life and the last one is developing and +leading technology and standards with + + align:start position:0% +leading technology and standards with + + + align:start position:0% +leading technology and standards with +mobile ad services using 900 MHz + + align:start position:0% + + + + align:start position:0% + +RFID I would like to introduce some + + align:start position:0% +RFID I would like to introduce some + + + align:start position:0% +RFID I would like to introduce some +examples of mobile ad services in this + + align:start position:0% +examples of mobile ad services in this + + + align:start position:0% +examples of mobile ad services in this +slide you can see the information + + align:start position:0% +slide you can see the information + + + align:start position:0% +slide you can see the information +providing service IDI tag is attached on + + align:start position:0% +providing service IDI tag is attached on + + + align:start position:0% +providing service IDI tag is attached on +PS or cases of medicine cover page of + + align:start position:0% +PS or cases of medicine cover page of + + + align:start position:0% +PS or cases of medicine cover page of +books vide tapes Etc using mobile phone + + align:start position:0% +books vide tapes Etc using mobile phone + + + align:start position:0% +books vide tapes Etc using mobile phone +which has artifi leadership inside Le + + align:start position:0% +which has artifi leadership inside Le + + + align:start position:0% +which has artifi leadership inside Le +this ad teag in the network there is + + align:start position:0% +this ad teag in the network there is + + + align:start position:0% +this ad teag in the network there is +some kind of server which provide + + align:start position:0% +some kind of server which provide + + + align:start position:0% +some kind of server which provide +content address mobile phone sends IDE + + align:start position:0% +content address mobile phone sends IDE + + + align:start position:0% +content address mobile phone sends IDE +tag ID or users Tex user data to This + + align:start position:0% +tag ID or users Tex user data to This + + + align:start position:0% +tag ID or users Tex user data to This +Server then the server returns address + + align:start position:0% +Server then the server returns address + + + align:start position:0% +Server then the server returns address +of contents in response to RI teag ID to + + align:start position:0% +of contents in response to RI teag ID to + + + align:start position:0% +of contents in response to RI teag ID to +mobile phone with this address mobile + + align:start position:0% +mobile phone with this address mobile + + + align:start position:0% +mobile phone with this address mobile +phone can access contents server which + + align:start position:0% +phone can access contents server which + + + align:start position:0% +phone can access contents server which +has contents for medicine books Etc + + align:start position:0% +has contents for medicine books Etc + + + align:start position:0% +has contents for medicine books Etc +these contents could be just a simple W + + align:start position:0% +these contents could be just a simple W + + + align:start position:0% +these contents could be just a simple W +that is a wireless application protocol + + align:start position:0% +that is a wireless application protocol + + + align:start position:0% +that is a wireless application protocol +page or multimedia data such as the + + align:start position:0% +page or multimedia data such as the + + + align:start position:0% +page or multimedia data such as the +preview of + + align:start position:0% + + + + align:start position:0% + +movie a product authentication is very + + align:start position:0% +movie a product authentication is very + + + align:start position:0% +movie a product authentication is very +good example of RF application there is + + align:start position:0% +good example of RF application there is + + + align:start position:0% +good example of RF application there is +a strong demand for product + + align:start position:0% +a strong demand for product + + + align:start position:0% +a strong demand for product +authentication in used car market food + + align:start position:0% +authentication in used car market food + + + align:start position:0% +authentication in used car market food +at drug industry medical user such as + + align:start position:0% +at drug industry medical user such as + + + align:start position:0% +at drug industry medical user such as +tracking broad supplies and almost all + + align:start position:0% +tracking broad supplies and almost all + + + align:start position:0% +tracking broad supplies and almost all +secondhand product markets so at first + + align:start position:0% +secondhand product markets so at first + + + align:start position:0% +secondhand product markets so at first +we developed the jinen authentication + + align:start position:0% +we developed the jinen authentication + + + align:start position:0% +we developed the jinen authentication +Service to detect the counterfeit + + align:start position:0% +Service to detect the counterfeit + + + align:start position:0% +Service to detect the counterfeit +product in + + align:start position:0% +product in + + + align:start position:0% +product in +domestic excuse me and the international + + align:start position:0% +domestic excuse me and the international + + + align:start position:0% +domestic excuse me and the international +market usion s Global loing function now + + align:start position:0% +market usion s Global loing function now + + + align:start position:0% +market usion s Global loing function now +these Services started three shops and + + align:start position:0% +these Services started three shops and + + + align:start position:0% +these Services started three shops and +the one department store as a trial + + align:start position:0% +the one department store as a trial + + + align:start position:0% +the one department store as a trial +business we use the handheld terminal + + align:start position:0% +business we use the handheld terminal + + + align:start position:0% +business we use the handheld terminal +combining with the CDM module and other + + align:start position:0% +combining with the CDM module and other + + + align:start position:0% +combining with the CDM module and other +by leader these services will launch + + align:start position:0% +by leader these services will launch + + + align:start position:0% +by leader these services will launch +commercially after verifying the + + align:start position:0% +commercially after verifying the + + + align:start position:0% +commercially after verifying the +performance + + align:start position:0% + + + + align:start position:0% + +mobile Ari technology can be applied for + + align:start position:0% +mobile Ari technology can be applied for + + + align:start position:0% +mobile Ari technology can be applied for +route guidance such as public + + align:start position:0% +route guidance such as public + + + align:start position:0% +route guidance such as public +transportation route and Road guidance + + align:start position:0% +transportation route and Road guidance + + + align:start position:0% +transportation route and Road guidance +in Leisure and lifestyle area it can be + + align:start position:0% +in Leisure and lifestyle area it can be + + + align:start position:0% +in Leisure and lifestyle area it can be +used for root guidance natural + + align:start position:0% +used for root guidance natural + + + align:start position:0% +used for root guidance natural +experience promotional events and for + + align:start position:0% +experience promotional events and for + + + align:start position:0% +experience promotional events and for +shopping banking applications and so on + + align:start position:0% +shopping banking applications and so on + + + align:start position:0% +shopping banking applications and so on +as Tel will start trial experience for + + align:start position:0% +as Tel will start trial experience for + + + align:start position:0% +as Tel will start trial experience for +these businesses within this year and + + align:start position:0% +these businesses within this year and + + + align:start position:0% +these businesses within this year and +plan do more business case for + + align:start position:0% +plan do more business case for + + + align:start position:0% +plan do more business case for +commercial after + + align:start position:0% +commercial after + + + align:start position:0% +commercial after +trial actually we draw PR about 200 + + align:start position:0% +trial actually we draw PR about 200 + + + align:start position:0% +trial actually we draw PR about 200 +different service models that will be + + align:start position:0% +different service models that will be + + + align:start position:0% +different service models that will be +Commercial Business targeting for our + + align:start position:0% +Commercial Business targeting for our + + + align:start position:0% +Commercial Business targeting for our +mobile + + align:start position:0% + + + + align:start position:0% + +customers after the major area of RFI + + align:start position:0% +customers after the major area of RFI + + + align:start position:0% +customers after the major area of RFI +technology is in information downloading + + align:start position:0% +technology is in information downloading + + + align:start position:0% +technology is in information downloading +applications the flower sales show is + + align:start position:0% +applications the flower sales show is + + + align:start position:0% +applications the flower sales show is +very good showcase for such a + + align:start position:0% +very good showcase for such a + + + align:start position:0% +very good showcase for such a +purpose uh scanning IDI text on prints + + align:start position:0% +purpose uh scanning IDI text on prints + + + align:start position:0% +purpose uh scanning IDI text on prints +and flowers we can get information of + + align:start position:0% +and flowers we can get information of + + + align:start position:0% +and flowers we can get information of +flowers like name place and the history + + align:start position:0% +flowers like name place and the history + + + align:start position:0% +flowers like name place and the history +of origin brooming time medical + + align:start position:0% +of origin brooming time medical + + + align:start position:0% +of origin brooming time medical +treatment as well as download of related + + align:start position:0% +treatment as well as download of related + + + align:start position:0% +treatment as well as download of related +pictures and the songs to mobile handset + + align:start position:0% +pictures and the songs to mobile handset + + + align:start position:0% +pictures and the songs to mobile handset +and combine with promotion events each + + align:start position:0% +and combine with promotion events each + + + align:start position:0% +and combine with promotion events each +customer request delivery of items for + + align:start position:0% +customer request delivery of items for + + + align:start position:0% +customer request delivery of items for +sale with mobile phone with a as a gift + + align:start position:0% +sale with mobile phone with a as a gift + + + align:start position:0% +sale with mobile phone with a as a gift +we can send the favorite song and the + + align:start position:0% +we can send the favorite song and the + + + align:start position:0% +we can send the favorite song and the +message with it by reading AR tag on + + align:start position:0% + + + + align:start position:0% + +flowers shops and restaurants are also + + align:start position:0% +flowers shops and restaurants are also + + + align:start position:0% +flowers shops and restaurants are also +perfectly well suit suited for deploying + + align:start position:0% +perfectly well suit suited for deploying + + + align:start position:0% +perfectly well suit suited for deploying +adap technology to enhance value for + + align:start position:0% +adap technology to enhance value for + + + align:start position:0% +adap technology to enhance value for +customers tags attached to the entrance + + align:start position:0% +customers tags attached to the entrance + + + align:start position:0% +customers tags attached to the entrance +and or table scan ofi tag with a mobile + + align:start position:0% +and or table scan ofi tag with a mobile + + + align:start position:0% +and or table scan ofi tag with a mobile +phone and then mobile phone display the + + align:start position:0% +phone and then mobile phone display the + + + align:start position:0% +phone and then mobile phone display the +contents users can access the contents + + align:start position:0% +contents users can access the contents + + + align:start position:0% +contents users can access the contents +very easily then download information + + align:start position:0% +very easily then download information + + + align:start position:0% +very easily then download information +about restaurant record their + + align:start position:0% +about restaurant record their + + + align:start position:0% +about restaurant record their +favorite page at their own site a + + align:start position:0% +favorite page at their own site a + + + align:start position:0% +favorite page at their own site a +businessman of sh needs to promote their + + align:start position:0% +businessman of sh needs to promote their + + + align:start position:0% +businessman of sh needs to promote their +product and record their information on + + align:start position:0% +product and record their information on + + + align:start position:0% +product and record their information on +mobile upon also customer can needs to + + align:start position:0% +mobile upon also customer can needs to + + + align:start position:0% +mobile upon also customer can needs to +decide the menu for lunch or dinner for + + align:start position:0% +decide the menu for lunch or dinner for + + + align:start position:0% +decide the menu for lunch or dinner for +especially this service is good mobile + + align:start position:0% +especially this service is good mobile + + + align:start position:0% +especially this service is good mobile +business because our customer desire + + align:start position:0% +business because our customer desire + + + align:start position:0% +business because our customer desire +personalized and customized services and + + align:start position:0% +personalized and customized services and + + + align:start position:0% +personalized and customized services and +more userfriendly + + align:start position:0% + + + + align:start position:0% + +access II based Road information service + + align:start position:0% +access II based Road information service + + + align:start position:0% +access II based Road information service +can be made into whole platform for + + align:start position:0% +can be made into whole platform for + + + align:start position:0% +can be made into whole platform for +providing all types of root information + + align:start position:0% +providing all types of root information + + + align:start position:0% +providing all types of root information +service aied technology can use location + + align:start position:0% +service aied technology can use location + + + align:start position:0% +service aied technology can use location +determination where cannot fulfilled by + + align:start position:0% +determination where cannot fulfilled by + + + align:start position:0% +determination where cannot fulfilled by +GPS technology such as inside of + + align:start position:0% +GPS technology such as inside of + + + align:start position:0% +GPS technology such as inside of +buildings and could ultimately be + + align:start position:0% +buildings and could ultimately be + + + align:start position:0% +buildings and could ultimately be +cheaper once Tech prices + + align:start position:0% +cheaper once Tech prices + + + align:start position:0% +cheaper once Tech prices +decline customers can get the root + + align:start position:0% +decline customers can get the root + + + align:start position:0% +decline customers can get the root +Guidance the is a store location + + align:start position:0% +Guidance the is a store location + + + align:start position:0% +Guidance the is a store location +location maps and the building + + align:start position:0% +location maps and the building + + + align:start position:0% +location maps and the building +information very easily and simply we + + align:start position:0% +information very easily and simply we + + + align:start position:0% +information very easily and simply we +expect these Services can increase the + + align:start position:0% +expect these Services can increase the + + + align:start position:0% +expect these Services can increase the +mobile data access + + align:start position:0% + + + + align:start position:0% + +traffic PO is sometimes very Troublesome + + align:start position:0% +traffic PO is sometimes very Troublesome + + + align:start position:0% +traffic PO is sometimes very Troublesome +work if the poll company can send the + + align:start position:0% +work if the poll company can send the + + + align:start position:0% +work if the poll company can send the +reward like free mobile phone bell sound + + align:start position:0% +reward like free mobile phone bell sound + + + align:start position:0% +reward like free mobile phone bell sound +download purchasing coupons so then + + align:start position:0% +download purchasing coupons so then + + + align:start position:0% +download purchasing coupons so then +customers can do it willingly users + + align:start position:0% +customers can do it willingly users + + + align:start position:0% +customers can do it willingly users +touch the aride tag attached on the bus + + align:start position:0% +touch the aride tag attached on the bus + + + align:start position:0% +touch the aride tag attached on the bus +stops Subway advertisement board and the + + align:start position:0% +stops Subway advertisement board and the + + + align:start position:0% +stops Subway advertisement board and the +download poll information on their + + align:start position:0% +download poll information on their + + + align:start position:0% +download poll information on their +mobile + + align:start position:0% + + + + align:start position:0% + +terminals our taxi is not always a safe + + align:start position:0% +terminals our taxi is not always a safe + + + align:start position:0% +terminals our taxi is not always a safe +place for woman and night saf Home + + align:start position:0% +place for woman and night saf Home + + + align:start position:0% +place for woman and night saf Home +Service uses adate technology to track + + align:start position:0% +Service uses adate technology to track + + + align:start position:0% +Service uses adate technology to track +taxes in case of theft and any other + + align:start position:0% +taxes in case of theft and any other + + + align:start position:0% +taxes in case of theft and any other +unpr experience a passenger may + + align:start position:0% +unpr experience a passenger may + + + align:start position:0% +unpr experience a passenger may +experience a passenger can lead the tag + + align:start position:0% +experience a passenger can lead the tag + + + align:start position:0% +experience a passenger can lead the tag +in installed in the taxi on the ceiling + + align:start position:0% +in installed in the taxi on the ceiling + + + align:start position:0% +in installed in the taxi on the ceiling +under the seat or under the driver + + align:start position:0% +under the seat or under the driver + + + align:start position:0% +under the seat or under the driver +registration card then taxi company send + + align:start position:0% +registration card then taxi company send + + + align:start position:0% +registration card then taxi company send +the information about the taxi to the + + align:start position:0% +the information about the taxi to the + + + align:start position:0% +the information about the taxi to the +passenger passenger can send those + + align:start position:0% +passenger passenger can send those + + + align:start position:0% +passenger passenger can send those +information to their parents or friends + + align:start position:0% +information to their parents or friends + + + align:start position:0% +information to their parents or friends +using the mobile sh message service + + align:start position:0% +using the mobile sh message service + + + align:start position:0% +using the mobile sh message service +pressing just the send button on mobile + + align:start position:0% +pressing just the send button on mobile + + + align:start position:0% +pressing just the send button on mobile +phone finally I think customers are + + align:start position:0% +phone finally I think customers are + + + align:start position:0% +phone finally I think customers are +always the most critical element in our + + align:start position:0% +always the most critical element in our + + + align:start position:0% +always the most critical element in our +business I believe that RFID can delive + + align:start position:0% +business I believe that RFID can delive + + + align:start position:0% +business I believe that RFID can delive +the success factors and get insight to + + align:start position:0% +the success factors and get insight to + + + align:start position:0% +the success factors and get insight to +the Future Direction operators must take + + align:start position:0% +the Future Direction operators must take + + + align:start position:0% +the Future Direction operators must take +if we study these issues from the + + align:start position:0% +if we study these issues from the + + + align:start position:0% +if we study these issues from the +customers perspective which enhance + + align:start position:0% +customers perspective which enhance + + + align:start position:0% +customers perspective which enhance +customer values and improve user + + align:start position:0% +customer values and improve user + + + align:start position:0% +customer values and improve user +friendliness we will SE continuous + + align:start position:0% +friendliness we will SE continuous + + + align:start position:0% +friendliness we will SE continuous +Technology Innovation to get the most + + align:start position:0% +Technology Innovation to get the most + + + align:start position:0% +Technology Innovation to get the most +optimal service + + align:start position:0% +optimal service + + + align:start position:0% +optimal service +environment thank you very much for your + + align:start position:0% +environment thank you very much for your + + + align:start position:0% +environment thank you very much for your +attention + + align:start position:0% + + + + align:start position:0% + +thank you very much are there any + + align:start position:0% +thank you very much are there any + + + align:start position:0% +thank you very much are there any +questions if there are if you could come + + align:start position:0% +questions if there are if you could come + + + align:start position:0% +questions if there are if you could come +down to the mic please and once again + + align:start position:0% +down to the mic please and once again + + + align:start position:0% +down to the mic please and once again +thanks very much to our our uh speakers + + align:start position:0% +thanks very much to our our uh speakers + + + align:start position:0% +thanks very much to our our uh speakers +who have come from halfway around the + + align:start position:0% + + + + align:start position:0% + +world if there if there + + align:start position:0% + + + + align:start position:0% + +oh hi I'm Matthew dorin from MIT and I + + align:start position:0% +oh hi I'm Matthew dorin from MIT and I + + + align:start position:0% +oh hi I'm Matthew dorin from MIT and I +have two questions for Mr Yun + + align:start position:0% +have two questions for Mr Yun + + + align:start position:0% +have two questions for Mr Yun +um first there are several different + + align:start position:0% +um first there are several different + + + align:start position:0% +um first there are several different +protocols that have been discussed for + + align:start position:0% +protocols that have been discussed for + + + align:start position:0% +protocols that have been discussed for +mobile RFID applications NFC is probably + + align:start position:0% +mobile RFID applications NFC is probably + + + align:start position:0% +mobile RFID applications NFC is probably +the most wellknown but there's also + + align:start position:0% +the most wellknown but there's also + + + align:start position:0% +the most wellknown but there's also +something called rch R and I think there + + align:start position:0% +something called rch R and I think there + + + align:start position:0% +something called rch R and I think there +are a few others so my first question is + + align:start position:0% +are a few others so my first question is + + + align:start position:0% +are a few others so my first question is +which of those do you see being the + + align:start position:0% +which of those do you see being the + + + align:start position:0% +which of those do you see being the +choice of SK Telecom or is it too soon + + align:start position:0% +choice of SK Telecom or is it too soon + + + align:start position:0% +choice of SK Telecom or is it too soon +to + + align:start position:0% +to + + + align:start position:0% +to +tell uh yes as Telecom consider the + + align:start position:0% +tell uh yes as Telecom consider the + + + align:start position:0% +tell uh yes as Telecom consider the +several technology like NFC RFID or CHP + + align:start position:0% +several technology like NFC RFID or CHP + + + align:start position:0% +several technology like NFC RFID or CHP +and many things when we compare the NFC + + align:start position:0% +and many things when we compare the NFC + + + align:start position:0% +and many things when we compare the NFC +and RFID 9 900 MH + + align:start position:0% +and RFID 9 900 MH + + + align:start position:0% +and RFID 9 900 MH +jfid uh NFC has the many uh dedicated + + align:start position:0% +jfid uh NFC has the many uh dedicated + + + align:start position:0% +jfid uh NFC has the many uh dedicated +functions like the security and the or + + align:start position:0% +functions like the security and the or + + + align:start position:0% +functions like the security and the or +many uh safe safe functions so that uh + + align:start position:0% +many uh safe safe functions so that uh + + + align:start position:0% +many uh safe safe functions so that uh +CH that tag is the more expensive than + + align:start position:0% +CH that tag is the more expensive than + + + align:start position:0% +CH that tag is the more expensive than +the 900 MHz tag + + align:start position:0% +the 900 MHz tag + + + align:start position:0% +the 900 MHz tag +tags also NFC needs the very short + + align:start position:0% +tags also NFC needs the very short + + + align:start position:0% +tags also NFC needs the very short +distance leading distance but R the tag + + align:start position:0% +distance leading distance but R the tag + + + align:start position:0% +distance leading distance but R the tag +is the uh longer distance so we selected + + align:start position:0% +is the uh longer distance so we selected + + + align:start position:0% +is the uh longer distance so we selected +the 900 + + align:start position:0% +the 900 + + + align:start position:0% +the 900 +MHz uh RFID for useful things and also + + align:start position:0% +MHz uh RFID for useful things and also + + + align:start position:0% +MHz uh RFID for useful things and also +we will study the NFC service as the pay + + align:start position:0% +we will study the NFC service as the pay + + + align:start position:0% +we will study the NFC service as the pay +or uh tickets okay so you would use the + + align:start position:0% +or uh tickets okay so you would use the + + + align:start position:0% +or uh tickets okay so you would use the +NFC service for payment for tickets we + + align:start position:0% +NFC service for payment for tickets we + + + align:start position:0% +NFC service for payment for tickets we +prepared now + + align:start position:0% +prepared now + + + align:start position:0% +prepared now +okay so this would sort of replace the + + align:start position:0% +okay so this would sort of replace the + + + align:start position:0% +okay so this would sort of replace the +Monita program that you have had or + + align:start position:0% +Monita program that you have had or + + + align:start position:0% +Monita program that you have had or +would it just be an extension of the + + align:start position:0% +would it just be an extension of the + + + align:start position:0% +would it just be an extension of the +Monita program yes okay okay thank + + align:start position:0% +Monita program yes okay okay thank + + + align:start position:0% +Monita program yes okay okay thank +you so thank you very much to the panel + + align:start position:0% +you so thank you very much to the panel + + + align:start position:0% +you so thank you very much to the panel +[Applause] \ No newline at end of file diff --git a/bFi8yxWZhR4.txt b/bFi8yxWZhR4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3ea2803e3818319f82f6a514360de3800e64a6f9 --- /dev/null +++ b/bFi8yxWZhR4.txt @@ -0,0 +1,363 @@ +align:start position:0% + +Team 15 is up Team 15 keeps going up and + + align:start position:0% +Team 15 is up Team 15 keeps going up and + + + align:start position:0% +Team 15 is up Team 15 keeps going up and +up + + align:start position:0% + + + + align:start position:0% + +and there we go + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +great effort by uh Team 15 with a + + align:start position:0% +great effort by uh Team 15 with a + + + align:start position:0% +great effort by uh Team 15 with a +beautiful + + align:start position:0% +beautiful + + + align:start position:0% +beautiful +Landing by English + + align:start position:0% +Landing by English + + + align:start position:0% +Landing by English +Bob + + align:start position:0% +Bob + + + align:start position:0% +Bob +beautiful I thought my life was + + align:start position:0% +beautiful I thought my life was + + + align:start position:0% +beautiful I thought my life was +uh was + + align:start position:0% + + + + align:start position:0% + +in e + + align:start position:0% + + + + align:start position:0% + +all right we have uh te 15 um they seem + + align:start position:0% +all right we have uh te 15 um they seem + + + align:start position:0% +all right we have uh te 15 um they seem +to have + + align:start position:0% +to have + + + align:start position:0% +to have +a placing the eggs inverted on the belly + + align:start position:0% +a placing the eggs inverted on the belly + + + align:start position:0% +a placing the eggs inverted on the belly +of the + + align:start position:0% +of the + + + align:start position:0% +of the +aircraft being very careful here + + align:start position:0% +aircraft being very careful here + + + align:start position:0% +aircraft being very careful here +we didn't see a whole lot of running on + + align:start position:0% +we didn't see a whole lot of running on + + + align:start position:0% +we didn't see a whole lot of running on +the charmac like we saw in + + align:start position:0% +the charmac like we saw in + + + align:start position:0% +the charmac like we saw in +um previous we have almost the whole + + align:start position:0% +um previous we have almost the whole + + + align:start position:0% +um previous we have almost the whole +crew working with the aircraft right + + align:start position:0% + + + + align:start position:0% + +now detailed + + align:start position:0% +now detailed + + + align:start position:0% +now detailed +operation's being rather serious about + + align:start position:0% +operation's being rather serious about + + + align:start position:0% +operation's being rather serious about +uh their work + + align:start position:0% +uh their work + + + align:start position:0% +uh their work +here find the detailed + + align:start position:0% +here find the detailed + + + align:start position:0% +here find the detailed +work careful and meticulous + + align:start position:0% + + + + align:start position:0% + +too they have two minutes without any + + align:start position:0% +too they have two minutes without any + + + align:start position:0% +too they have two minutes without any +sort of penalty + + align:start position:0% +sort of penalty + + + align:start position:0% +sort of penalty +which is an innovation that Colonel + + align:start position:0% +which is an innovation that Colonel + + + align:start position:0% +which is an innovation that Colonel +young brought to the competition sort of + + align:start position:0% +young brought to the competition sort of + + + align:start position:0% +young brought to the competition sort of +Ensure students didn't rush and um + + align:start position:0% +Ensure students didn't rush and um + + + align:start position:0% +Ensure students didn't rush and um +potentially damage their airplanes so + + align:start position:0% +potentially damage their airplanes so + + + align:start position:0% +potentially damage their airplanes so +going to give them 2 minutes no penalty + + align:start position:0% +going to give them 2 minutes no penalty + + + align:start position:0% +going to give them 2 minutes no penalty +to get it all right + + align:start position:0% + + + + align:start position:0% + +and that first place + + align:start position:0% +and that first place + + + align:start position:0% +and that first place +team + + align:start position:0% +team + + + align:start position:0% +team +good all right we have the resident + + align:start position:0% +good all right we have the resident + + + align:start position:0% +good all right we have the resident +Argentinian + + align:start position:0% + + + + align:start position:0% + +and now English + + align:start position:0% + + + + align:start position:0% + +Bob but I think everybody else is just + + align:start position:0% +Bob but I think everybody else is just + + + align:start position:0% +Bob but I think everybody else is just +boring playing All + + align:start position:0% + + + + align:start position:0% + +American flying a little + + align:start position:0% +American flying a little + + + align:start position:0% +American flying a little +high this team has a teail + + align:start position:0% + + + + align:start position:0% + +configuration and uh + + align:start position:0% +configuration and uh + + + align:start position:0% +configuration and uh +English Bob is doing + + align:start position:0% +English Bob is doing + + + align:start position:0% +English Bob is doing +his best 35 seconds all right 35 seconds + + align:start position:0% +his best 35 seconds all right 35 seconds + + + align:start position:0% +his best 35 seconds all right 35 seconds +[Applause] \ No newline at end of file diff --git a/bHdzkFrgRcA.txt b/bHdzkFrgRcA.txt new file mode 100644 index 0000000000000000000000000000000000000000..07a609f7e805790d53d75c9e671690fe29b8e723 --- /dev/null +++ b/bHdzkFrgRcA.txt @@ -0,0 +1,7736 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so okay so remember last + + align:start position:0% +ocw.mit.edu so okay so remember last + + + align:start position:0% +ocw.mit.edu so okay so remember last +time + + align:start position:0% + + + + align:start position:0% + +we learned about the cross product of + + align:start position:0% +we learned about the cross product of + + + align:start position:0% +we learned about the cross product of +vectors in + + align:start position:0% + + + + align:start position:0% + +space + + align:start position:0% +space + + + align:start position:0% +space +so remember the definition of cross + + align:start position:0% +so remember the definition of cross + + + align:start position:0% +so remember the definition of cross +product is in terms of this + + align:start position:0% +product is in terms of this + + + align:start position:0% +product is in terms of this +determinant I hat J hat K hat and then + + align:start position:0% +determinant I hat J hat K hat and then + + + align:start position:0% +determinant I hat J hat K hat and then +the components of a A1 A2 A3 and then + + align:start position:0% +the components of a A1 A2 A3 and then + + + align:start position:0% +the components of a A1 A2 A3 and then +the components of + + align:start position:0% +the components of + + + align:start position:0% +the components of +B and + + align:start position:0% +B and + + + align:start position:0% +B and +this is not an actual determinant + + align:start position:0% +this is not an actual determinant + + + align:start position:0% +this is not an actual determinant +because these are not numbers but it's a + + align:start position:0% +because these are not numbers but it's a + + + align:start position:0% +because these are not numbers but it's a +symbolic notation to remember what the + + align:start position:0% +symbolic notation to remember what the + + + align:start position:0% +symbolic notation to remember what the +actual formula is and the actual formula + + align:start position:0% +actual formula is and the actual formula + + + align:start position:0% +actual formula is and the actual formula +is obtained by + + align:start position:0% +is obtained by + + + align:start position:0% +is obtained by +expanding the determinant so we have + + align:start position:0% +expanding the determinant so we have + + + align:start position:0% +expanding the determinant so we have +actually this smaller determinant A2 A3 + + align:start position:0% +actually this smaller determinant A2 A3 + + + align:start position:0% +actually this smaller determinant A2 A3 +B2 B3 * I + + align:start position:0% +B2 B3 * I + + + align:start position:0% +B2 B3 * I +hat minus determinant of A1 A3 B1 B3 * J + + align:start position:0% +hat minus determinant of A1 A3 B1 B3 * J + + + align:start position:0% +hat minus determinant of A1 A3 B1 B3 * J +hat + + align:start position:0% +hat + + + align:start position:0% +hat +plus determinant of A1 A2 B1 B2 * + + align:start position:0% + + + + align:start position:0% + +K and we also saw a more geometric + + align:start position:0% +K and we also saw a more geometric + + + align:start position:0% +K and we also saw a more geometric +definition of a cross + + align:start position:0% + + + + align:start position:0% + +product so we've learned + + align:start position:0% +product so we've learned + + + align:start position:0% +product so we've learned +that + + align:start position:0% +that + + + align:start position:0% +that +the length of the cross product is equal + + align:start position:0% +the length of the cross product is equal + + + align:start position:0% +the length of the cross product is equal +to the area of the parallelogram + + align:start position:0% + + + + align:start position:0% + +with sides A and + + align:start position:0% + + + + align:start position:0% + +B we've also learned that the + + align:start position:0% +B we've also learned that the + + + align:start position:0% +B we've also learned that the +direction of the cross + + align:start position:0% + + + + align:start position:0% + +product is given by taking the direction + + align:start position:0% +product is given by taking the direction + + + align:start position:0% +product is given by taking the direction +that's perpendicular + + align:start position:0% +that's perpendicular + + + align:start position:0% +that's perpendicular +to A and + + align:start position:0% +to A and + + + align:start position:0% +to A and +B so in + + align:start position:0% +B so in + + + align:start position:0% +B so in +fact if I draw a and b in a + + align:start position:0% +fact if I draw a and b in a + + + align:start position:0% +fact if I draw a and b in a +plane they determine a plane together + + align:start position:0% +plane they determine a plane together + + + align:start position:0% +plane they determine a plane together +then the cross product should go in a + + align:start position:0% +then the cross product should go in a + + + align:start position:0% +then the cross product should go in a +Direction that's perpendicular to that + + align:start position:0% + + + + align:start position:0% + +plane now there's two different possible + + align:start position:0% +plane now there's two different possible + + + align:start position:0% +plane now there's two different possible +directions that are perpendicular to a + + align:start position:0% +directions that are perpendicular to a + + + align:start position:0% +directions that are perpendicular to a +plane and to decide which one it is we + + align:start position:0% +plane and to decide which one it is we + + + align:start position:0% +plane and to decide which one it is we +use the right hand rule + + align:start position:0% + + + + align:start position:0% + +which says if you extend your right hand + + align:start position:0% +which says if you extend your right hand + + + align:start position:0% +which says if you extend your right hand +in the direction of vector a then curve + + align:start position:0% +in the direction of vector a then curve + + + align:start position:0% +in the direction of vector a then curve +your fingers in the direction of B then + + align:start position:0% +your fingers in the direction of B then + + + align:start position:0% +your fingers in the direction of B then +your thumb will go in the direction of + + align:start position:0% +your thumb will go in the direction of + + + align:start position:0% +your thumb will go in the direction of +the cross + + align:start position:0% +the cross + + + align:start position:0% +the cross +product + + align:start position:0% +product + + + align:start position:0% +product +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so one thing I didn't quite get to say + + align:start position:0% +so one thing I didn't quite get to say + + + align:start position:0% +so one thing I didn't quite get to say +last time is that there are some funny + + align:start position:0% +last time is that there are some funny + + + align:start position:0% +last time is that there are some funny +manipulation rules um what are we + + align:start position:0% +manipulation rules um what are we + + + align:start position:0% +manipulation rules um what are we +allowed to do or not do with cross + + align:start position:0% +allowed to do or not do with cross + + + align:start position:0% +allowed to do or not do with cross +products so let me tell you right away + + align:start position:0% +products so let me tell you right away + + + align:start position:0% +products so let me tell you right away +the most surprising one maybe if you've + + align:start position:0% +the most surprising one maybe if you've + + + align:start position:0% +the most surprising one maybe if you've +never seen it before it's that A cross B + + align:start position:0% +never seen it before it's that A cross B + + + align:start position:0% +never seen it before it's that A cross B +and B cross a are not the same + + align:start position:0% +and B cross a are not the same + + + align:start position:0% +and B cross a are not the same +thing okay why are they not the same + + align:start position:0% +thing okay why are they not the same + + + align:start position:0% +thing okay why are they not the same +thing well when way to see it is to + + align:start position:0% +thing well when way to see it is to + + + align:start position:0% +thing well when way to see it is to +think geometrically sure the + + align:start position:0% +think geometrically sure the + + + align:start position:0% +think geometrically sure the +parallelogram still has the same area + + align:start position:0% +parallelogram still has the same area + + + align:start position:0% +parallelogram still has the same area +and it's still in the same plane so + + align:start position:0% +and it's still in the same plane so + + + align:start position:0% +and it's still in the same plane so +still perpendicular to the same plane + + align:start position:0% +still perpendicular to the same plane + + + align:start position:0% +still perpendicular to the same plane +but what happens is if you try to apply + + align:start position:0% +but what happens is if you try to apply + + + align:start position:0% +but what happens is if you try to apply +the right hand rle but exchanging the + + align:start position:0% +the right hand rle but exchanging the + + + align:start position:0% +the right hand rle but exchanging the +roles of A and B then you will either + + align:start position:0% +roles of A and B then you will either + + + align:start position:0% +roles of A and B then you will either +injure yourself or you will end up + + align:start position:0% +injure yourself or you will end up + + + align:start position:0% +injure yourself or you will end up +pointing in the opposite direction okay + + align:start position:0% +pointing in the opposite direction okay + + + align:start position:0% +pointing in the opposite direction okay +so in + + align:start position:0% +so in + + + align:start position:0% +so in +fact B cross A and A cross B are + + align:start position:0% +fact B cross A and A cross B are + + + align:start position:0% +fact B cross A and A cross B are +opposite of each other and you can check + + align:start position:0% +opposite of each other and you can check + + + align:start position:0% +opposite of each other and you can check +that in the formula because see for + + align:start position:0% +that in the formula because see for + + + align:start position:0% +that in the formula because see for +example the I component is A2 B3 minus + + align:start position:0% +example the I component is A2 B3 minus + + + align:start position:0% +example the I component is A2 B3 minus +A3 B2 if you swap the roles of A and B + + align:start position:0% +A3 B2 if you swap the roles of A and B + + + align:start position:0% +A3 B2 if you swap the roles of A and B +you will also have to change the + + align:start position:0% +you will also have to change the + + + align:start position:0% +you will also have to change the +signs okay so that's a slightly + + align:start position:0% +signs okay so that's a slightly + + + align:start position:0% +signs okay so that's a slightly +surprising think but you'll see one + + align:start position:0% +surprising think but you'll see one + + + align:start position:0% +surprising think but you'll see one +easily adjust to it it just means resist + + align:start position:0% +easily adjust to it it just means resist + + + align:start position:0% +easily adjust to it it just means resist +the temptation to write you know a + + align:start position:0% +the temptation to write you know a + + + align:start position:0% +the temptation to write you know a +equals ba whenever you do that put a + + align:start position:0% +equals ba whenever you do that put a + + + align:start position:0% +equals ba whenever you do that put a +minus + + align:start position:0% + + + + align:start position:0% + +sign now in + + align:start position:0% + + + + align:start position:0% + +particular well what happens if I do a + + align:start position:0% +particular well what happens if I do a + + + align:start position:0% +particular well what happens if I do a +cross + + align:start position:0% +cross + + + align:start position:0% +cross +a well I will get zero and you know + + align:start position:0% +a well I will get zero and you know + + + align:start position:0% +a well I will get zero and you know +there's many ways to see that when is to + + align:start position:0% +there's many ways to see that when is to + + + align:start position:0% +there's many ways to see that when is to +use the formula uh also you can say just + + align:start position:0% +use the formula uh also you can say just + + + align:start position:0% +use the formula uh also you can say just +that you know the parallelogram formed + + align:start position:0% +that you know the parallelogram formed + + + align:start position:0% +that you know the parallelogram formed +by a and a is completely flat and it has + + align:start position:0% +by a and a is completely flat and it has + + + align:start position:0% +by a and a is completely flat and it has +area zero so that's the zero + + align:start position:0% +area zero so that's the zero + + + align:start position:0% +area zero so that's the zero +Vector + + align:start position:0% + + + + align:start position:0% + +okay so hopefully you got practice with + + align:start position:0% +okay so hopefully you got practice with + + + align:start position:0% +okay so hopefully you got practice with +cross products and Computing them in + + align:start position:0% +cross products and Computing them in + + + align:start position:0% +cross products and Computing them in +recitation + + align:start position:0% +recitation + + + align:start position:0% +recitation +yesterday uh let me just point out one + + align:start position:0% +yesterday uh let me just point out one + + + align:start position:0% +yesterday uh let me just point out one +important application of cross product + + align:start position:0% +important application of cross product + + + align:start position:0% +important application of cross product +that maybe you haven't seen yet + + align:start position:0% + + + + align:start position:0% + +so let's say that I'm given three points + + align:start position:0% +so let's say that I'm given three points + + + align:start position:0% +so let's say that I'm given three points +in space and I want to find the equation + + align:start position:0% +in space and I want to find the equation + + + align:start position:0% +in space and I want to find the equation +of a plane that contains them so say I + + align:start position:0% +of a plane that contains them so say I + + + align:start position:0% +of a plane that contains them so say I +have P1 P2 P3 three points in + + align:start position:0% +have P1 P2 P3 three points in + + + align:start position:0% +have P1 P2 P3 three points in +space well they determine a plane I mean + + align:start position:0% +space well they determine a plane I mean + + + align:start position:0% +space well they determine a plane I mean +at least if they not aligned and we + + align:start position:0% +at least if they not aligned and we + + + align:start position:0% +at least if they not aligned and we +would like to find the equation of the + + align:start position:0% +would like to find the equation of the + + + align:start position:0% +would like to find the equation of the +plane that we determine so that means + + align:start position:0% +plane that we determine so that means + + + align:start position:0% +plane that we determine so that means +let's say that we have a point p in + + align:start position:0% +let's say that we have a point p in + + + align:start position:0% +let's say that we have a point p in +space with coordinates x y z + + align:start position:0% + + + + align:start position:0% + +well the equation of the + + align:start position:0% + + + + align:start position:0% + +plane let's say the plane containing P1 + + align:start position:0% +plane let's say the plane containing P1 + + + align:start position:0% +plane let's say the plane containing P1 +P2 and + + align:start position:0% +P2 and + + + align:start position:0% +P2 and +P3 that so that means find a + + align:start position:0% +P3 that so that means find a + + + align:start position:0% +P3 that so that means find a +condition we need to find a condition on + + align:start position:0% +condition we need to find a condition on + + + align:start position:0% +condition we need to find a condition on +the coordinates + + align:start position:0% +the coordinates + + + align:start position:0% +the coordinates +XYZ telling us + + align:start position:0% + + + + align:start position:0% + +whether p is in the plane or + + align:start position:0% + + + + align:start position:0% + +not okay so we have several ways of + + align:start position:0% +not okay so we have several ways of + + + align:start position:0% +not okay so we have several ways of +doing + + align:start position:0% +doing + + + align:start position:0% +doing +that for example one thing we could do + + align:start position:0% +that for example one thing we could do + + + align:start position:0% +that for example one thing we could do +let me just backtrack to determinants + + align:start position:0% +let me just backtrack to determinants + + + align:start position:0% +let me just backtrack to determinants +that we saw last time so one way to + + align:start position:0% +that we saw last time so one way to + + + align:start position:0% +that we saw last time so one way to +think about it is to + + align:start position:0% +think about it is to + + + align:start position:0% +think about it is to +consider these vectors P1 P2 P1 P3 and + + align:start position:0% +consider these vectors P1 P2 P1 P3 and + + + align:start position:0% +consider these vectors P1 P2 P1 P3 and +P1 + + align:start position:0% +P1 + + + align:start position:0% +P1 +P okay so the question of whether + + align:start position:0% +P okay so the question of whether + + + align:start position:0% +P okay so the question of whether +they're all in the same plane is the + + align:start position:0% +they're all in the same plane is the + + + align:start position:0% +they're all in the same plane is the +same as asking ourselves whether the + + align:start position:0% +same as asking ourselves whether the + + + align:start position:0% +same as asking ourselves whether the +parallelepiped that they form is + + align:start position:0% +parallelepiped that they form is + + + align:start position:0% +parallelepiped that they form is +actually completely + + align:start position:0% +actually completely + + + align:start position:0% +actually completely +flattened right if I try to form a + + align:start position:0% +flattened right if I try to form a + + + align:start position:0% +flattened right if I try to form a +parallelepiped with these three sides + + align:start position:0% +parallelepiped with these three sides + + + align:start position:0% +parallelepiped with these three sides +well if p is not in the plane then it + + align:start position:0% +well if p is not in the plane then it + + + align:start position:0% +well if p is not in the plane then it +will have some volume but if p is in the + + align:start position:0% +will have some volume but if p is in the + + + align:start position:0% +will have some volume but if p is in the +plane that means that it's actually + + align:start position:0% +plane that means that it's actually + + + align:start position:0% +plane that means that it's actually +completely + + align:start position:0% +completely + + + align:start position:0% +completely +squished so one possible answer + + align:start position:0% +squished so one possible answer + + + align:start position:0% +squished so one possible answer +one way to think of the equation of a + + align:start position:0% +one way to think of the equation of a + + + align:start position:0% +one way to think of the equation of a +plane should be that the determinant of + + align:start position:0% +plane should be that the determinant of + + + align:start position:0% +plane should be that the determinant of +these + + align:start position:0% +these + + + align:start position:0% +these +vectors should be + + align:start position:0% +vectors should be + + + align:start position:0% +vectors should be +zero determinant of P1 + + align:start position:0% +zero determinant of P1 + + + align:start position:0% +zero determinant of P1 +P2 P1 P3 and actually let me do it in a + + align:start position:0% +P2 P1 P3 and actually let me do it in a + + + align:start position:0% +P2 P1 P3 and actually let me do it in a +different order it doesn't really matter + + align:start position:0% + + + + align:start position:0% + +but so one possible way to + + align:start position:0% + + + + align:start position:0% + +express the condition that P is in the + + align:start position:0% +express the condition that P is in the + + + align:start position:0% +express the condition that P is in the +plane is to say that the determinant of + + align:start position:0% +plane is to say that the determinant of + + + align:start position:0% +plane is to say that the determinant of +these three vectors has to be zero and + + align:start position:0% +these three vectors has to be zero and + + + align:start position:0% +these three vectors has to be zero and +if I'm given coordinates for these + + align:start position:0% +if I'm given coordinates for these + + + align:start position:0% +if I'm given coordinates for these +points I mean I'm not giving you numbers + + align:start position:0% +points I mean I'm not giving you numbers + + + align:start position:0% +points I mean I'm not giving you numbers +but if I gave you numbers then you would + + align:start position:0% +but if I gave you numbers then you would + + + align:start position:0% +but if I gave you numbers then you would +be able to plug these numbers in so you + + align:start position:0% +be able to plug these numbers in so you + + + align:start position:0% +be able to plug these numbers in so you +could compute these two vectors + + align:start position:0% +could compute these two vectors + + + align:start position:0% +could compute these two vectors +explicitly you would have numbers here + + align:start position:0% +explicitly you would have numbers here + + + align:start position:0% +explicitly you would have numbers here +but here of course this would depend on + + align:start position:0% +but here of course this would depend on + + + align:start position:0% +but here of course this would depend on +X Y and Z so when you compute the + + align:start position:0% +X Y and Z so when you compute the + + + align:start position:0% +X Y and Z so when you compute the +determinant you get a formula that + + align:start position:0% +determinant you get a formula that + + + align:start position:0% +determinant you get a formula that +involves X Y and Z and you will find + + align:start position:0% +involves X Y and Z and you will find + + + align:start position:0% +involves X Y and Z and you will find +that this condition in XYZ that's the + + align:start position:0% +that this condition in XYZ that's the + + + align:start position:0% +that this condition in XYZ that's the +equation of a plane okay so we're going + + align:start position:0% +equation of a plane okay so we're going + + + align:start position:0% +equation of a plane okay so we're going +to see more about that pretty soon now + + align:start position:0% +to see more about that pretty soon now + + + align:start position:0% +to see more about that pretty soon now +let me tell you about a slightly faster + + align:start position:0% +let me tell you about a slightly faster + + + align:start position:0% +let me tell you about a slightly faster +way of doing + + align:start position:0% +way of doing + + + align:start position:0% +way of doing +it actually it's not much faster it's + + align:start position:0% +it actually it's not much faster it's + + + align:start position:0% +it actually it's not much faster it's +pretty much the same calculation but + + align:start position:0% +pretty much the same calculation but + + + align:start position:0% +pretty much the same calculation but +it's maybe more + + align:start position:0% +it's maybe more + + + align:start position:0% +it's maybe more +enlightening oh let me actually show you + + align:start position:0% +enlightening oh let me actually show you + + + align:start position:0% +enlightening oh let me actually show you +the nice color picture that I prepared + + align:start position:0% +the nice color picture that I prepared + + + align:start position:0% +the nice color picture that I prepared +for + + align:start position:0% + + + + align:start position:0% + +this okay + + align:start position:0% + + + + align:start position:0% + +so all right so one thing that's on this + + align:start position:0% +so all right so one thing that's on this + + + align:start position:0% +so all right so one thing that's on this +picture that I haven't thrown there is + + align:start position:0% +picture that I haven't thrown there is + + + align:start position:0% +picture that I haven't thrown there is +the normal Vector to the plane so why is + + align:start position:0% +the normal Vector to the plane so why is + + + align:start position:0% +the normal Vector to the plane so why is +that well let's say that we know how to + + align:start position:0% +that well let's say that we know how to + + + align:start position:0% +that well let's say that we know how to +find a vector that's perpendicular to + + align:start position:0% +find a vector that's perpendicular to + + + align:start position:0% +find a vector that's perpendicular to +our plane then what does it mean for the + + align:start position:0% +our plane then what does it mean for the + + + align:start position:0% +our plane then what does it mean for the +point P to be in the plane well it means + + align:start position:0% +point P to be in the plane well it means + + + align:start position:0% +point P to be in the plane well it means +that the direction say from P1 to P has + + align:start position:0% +that the direction say from P1 to P has + + + align:start position:0% +that the direction say from P1 to P has +to be perpendicular to this Vector + + align:start position:0% + + + + align:start position:0% + +n okay so here's another solution + + align:start position:0% + + + + align:start position:0% + +so p is in the + + align:start position:0% + + + + align:start position:0% + +plane only when well exactly + + align:start position:0% +plane only when well exactly + + + align:start position:0% +plane only when well exactly +when the vector P1 p is perpendicular to + + align:start position:0% +when the vector P1 p is perpendicular to + + + align:start position:0% +when the vector P1 p is perpendicular to +n where n is some + + align:start position:0% +n where n is some + + + align:start position:0% +n where n is some +Vector that's perpendicular to the plane + + align:start position:0% +Vector that's perpendicular to the plane + + + align:start position:0% +Vector that's perpendicular to the plane +so that's called a normal + + align:start position:0% +so that's called a normal + + + align:start position:0% +so that's called a normal +Vector not that the other are abnormal + + align:start position:0% +Vector not that the other are abnormal + + + align:start position:0% +Vector not that the other are abnormal +but uh + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so how do we rephrase this + + align:start position:0% +so how do we rephrase this + + + align:start position:0% +so how do we rephrase this +condition well we've learned how to + + align:start position:0% +condition well we've learned how to + + + align:start position:0% +condition well we've learned how to +detect whether two vectors are + + align:start position:0% +detect whether two vectors are + + + align:start position:0% +detect whether two vectors are +perpendicular to each other using dot + + align:start position:0% +perpendicular to each other using dot + + + align:start position:0% +perpendicular to each other using dot +product okay dot product that's the + + align:start position:0% +product okay dot product that's the + + + align:start position:0% +product okay dot product that's the +first + + align:start position:0% +first + + + align:start position:0% +first +lecture so these two vectors are + + align:start position:0% +lecture so these two vectors are + + + align:start position:0% +lecture so these two vectors are +perpendicular exactly when their dot + + align:start position:0% +perpendicular exactly when their dot + + + align:start position:0% +perpendicular exactly when their dot +product is + + align:start position:0% +product is + + + align:start position:0% +product is +zero okay and so now concretely well if + + align:start position:0% +zero okay and so now concretely well if + + + align:start position:0% +zero okay and so now concretely well if +we + + align:start position:0% +we + + + align:start position:0% +we +we have a point P1 given to us and say + + align:start position:0% +we have a point P1 given to us and say + + + align:start position:0% +we have a point P1 given to us and say +we have been able to compute the vector + + align:start position:0% +we have been able to compute the vector + + + align:start position:0% +we have been able to compute the vector +n then well when we actually compute + + align:start position:0% +n then well when we actually compute + + + align:start position:0% +n then well when we actually compute +what happens here we will have the + + align:start position:0% +what happens here we will have the + + + align:start position:0% +what happens here we will have the +coordinates XYZ of a point p and we'll + + align:start position:0% +coordinates XYZ of a point p and we'll + + + align:start position:0% +coordinates XYZ of a point p and we'll +get some condition on XYZ that will be + + align:start position:0% +get some condition on XYZ that will be + + + align:start position:0% +get some condition on XYZ that will be +the equation of a plane + + align:start position:0% +the equation of a plane + + + align:start position:0% +the equation of a plane +again now why are these things the + + align:start position:0% +again now why are these things the + + + align:start position:0% +again now why are these things the +same well before I can tell you that I + + align:start position:0% +same well before I can tell you that I + + + align:start position:0% +same well before I can tell you that I +should tell you how can we find a normal + + align:start position:0% +should tell you how can we find a normal + + + align:start position:0% +should tell you how can we find a normal +Vector but maybe you are already + + align:start position:0% +Vector but maybe you are already + + + align:start position:0% +Vector but maybe you are already +starting to see what the method should + + align:start position:0% +starting to see what the method should + + + align:start position:0% +starting to see what the method should +be because we know how to find vectors + + align:start position:0% +be because we know how to find vectors + + + align:start position:0% +be because we know how to find vectors +perpendicular to two given + + align:start position:0% +perpendicular to two given + + + align:start position:0% +perpendicular to two given +vectors right so we know two vectors in + + align:start position:0% +vectors right so we know two vectors in + + + align:start position:0% +vectors right so we know two vectors in +that plane for example P1 P2 and P1 P3 + + align:start position:0% +that plane for example P1 P2 and P1 P3 + + + align:start position:0% +that plane for example P1 P2 and P1 P3 +actually I could have used you know + + align:start position:0% +actually I could have used you know + + + align:start position:0% +actually I could have used you know +another permutation of the points but + + align:start position:0% +another permutation of the points but + + + align:start position:0% +another permutation of the points but +let's use these so if I want to find a + + align:start position:0% +let's use these so if I want to find a + + + align:start position:0% +let's use these so if I want to find a +vector that's perpendicular to both P1 + + align:start position:0% +vector that's perpendicular to both P1 + + + align:start position:0% +vector that's perpendicular to both P1 +P2 and P1 P3 at the same time all I have + + align:start position:0% +P2 and P1 P3 at the same time all I have + + + align:start position:0% +P2 and P1 P3 at the same time all I have +to do is take the cross + + align:start position:0% +to do is take the cross + + + align:start position:0% +to do is take the cross +product + + align:start position:0% +product + + + align:start position:0% +product +so how do we + + align:start position:0% +so how do we + + + align:start position:0% +so how do we +find this Vector that's perpendicular to + + align:start position:0% +find this Vector that's perpendicular to + + + align:start position:0% +find this Vector that's perpendicular to +the + + align:start position:0% +the + + + align:start position:0% +the +plane well the answer + + align:start position:0% +plane well the answer + + + align:start position:0% +plane well the answer +is we can just take the cross product P1 + + align:start position:0% +is we can just take the cross product P1 + + + align:start position:0% +is we can just take the cross product P1 +P2 cross P1 + + align:start position:0% + + + + align:start position:0% + +P3 I should say well you know say that + + align:start position:0% +P3 I should say well you know say that + + + align:start position:0% +P3 I should say well you know say that +actually you took the point in a + + align:start position:0% +actually you took the point in a + + + align:start position:0% +actually you took the point in a +different order you did P1 P3 cross P1 + + align:start position:0% +different order you did P1 P3 cross P1 + + + align:start position:0% +different order you did P1 P3 cross P1 +P2 you would get of course the opposite + + align:start position:0% +P2 you would get of course the opposite + + + align:start position:0% +P2 you would get of course the opposite +Vector but it's fine any plane has + + align:start position:0% +Vector but it's fine any plane has + + + align:start position:0% +Vector but it's fine any plane has +actually infinitely many normal vectors + + align:start position:0% +actually infinitely many normal vectors + + + align:start position:0% +actually infinitely many normal vectors +you can just you know multiply the + + align:start position:0% +you can just you know multiply the + + + align:start position:0% +you can just you know multiply the +normal vector by any constant you will + + align:start position:0% +normal vector by any constant you will + + + align:start position:0% +normal vector by any constant you will +still get a normal Vector that's + + align:start position:0% +still get a normal Vector that's + + + align:start position:0% +still get a normal Vector that's +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +fine + + align:start position:0% +fine + + + align:start position:0% +fine +so that's going to be one of the main + + align:start position:0% +so that's going to be one of the main + + + align:start position:0% +so that's going to be one of the main +uses of dot product see when we know two + + align:start position:0% +uses of dot product see when we know two + + + align:start position:0% +uses of dot product see when we know two +vectors in a plane it lets us find the + + align:start position:0% +vectors in a plane it lets us find the + + + align:start position:0% +vectors in a plane it lets us find the +normal Vector to the plane and that is + + align:start position:0% +normal Vector to the plane and that is + + + align:start position:0% +normal Vector to the plane and that is +what we need to find the + + align:start position:0% +what we need to find the + + + align:start position:0% +what we need to find the +equation now why is that the same as the + + align:start position:0% +equation now why is that the same as the + + + align:start position:0% +equation now why is that the same as the +answer over + + align:start position:0% + + + + align:start position:0% + +there well + + align:start position:0% +there well + + + align:start position:0% +there well +the condition that we have is that P1 P + + align:start position:0% +the condition that we have is that P1 P + + + align:start position:0% +the condition that we have is that P1 P +do + + align:start position:0% +do + + + align:start position:0% +do +n should be zero and we said n is + + align:start position:0% +n should be zero and we said n is + + + align:start position:0% +n should be zero and we said n is +actually P1 + + align:start position:0% +actually P1 + + + align:start position:0% +actually P1 +P2 cross P1 + + align:start position:0% +P2 cross P1 + + + align:start position:0% +P2 cross P1 +P3 so this is what we want to be zero + + align:start position:0% +P3 so this is what we want to be zero + + + align:start position:0% +P3 so this is what we want to be zero +now if you remember stuff from a long + + align:start position:0% +now if you remember stuff from a long + + + align:start position:0% +now if you remember stuff from a long +time ago I mean that was Friday um then + + align:start position:0% +time ago I mean that was Friday um then + + + align:start position:0% +time ago I mean that was Friday um then +we've introduced this thing and called + + align:start position:0% +we've introduced this thing and called + + + align:start position:0% +we've introduced this thing and called +it the triple + + align:start position:0% + + + + align:start position:0% + +product okay and what we've seen is that + + align:start position:0% +product okay and what we've seen is that + + + align:start position:0% +product okay and what we've seen is that +the triple product is the same thing as + + align:start position:0% +the triple product is the same thing as + + + align:start position:0% +the triple product is the same thing as +the determinant so in fact these two + + align:start position:0% +the determinant so in fact these two + + + align:start position:0% +the determinant so in fact these two +ways of thinking one saying that the Box + + align:start position:0% +ways of thinking one saying that the Box + + + align:start position:0% +ways of thinking one saying that the Box +formed by these three vectors should be + + align:start position:0% +formed by these three vectors should be + + + align:start position:0% +formed by these three vectors should be +flat and have volume zero and the other + + align:start position:0% +flat and have volume zero and the other + + + align:start position:0% +flat and have volume zero and the other +one saying that we can find a normal + + align:start position:0% +one saying that we can find a normal + + + align:start position:0% +one saying that we can find a normal +vector and then Express the condition + + align:start position:0% +vector and then Express the condition + + + align:start position:0% +vector and then Express the condition +that a vector is in the plane if it's + + align:start position:0% +that a vector is in the plane if it's + + + align:start position:0% +that a vector is in the plane if it's +perpendicular to the normal Vector + + align:start position:0% +perpendicular to the normal Vector + + + align:start position:0% +perpendicular to the normal Vector +they're actually giving us the same + + align:start position:0% +they're actually giving us the same + + + align:start position:0% +they're actually giving us the same +formula in the + + align:start position:0% + + + + align:start position:0% + +end + + align:start position:0% +end + + + align:start position:0% +end +okay any quick questions before we move + + align:start position:0% +okay any quick questions before we move + + + align:start position:0% +okay any quick questions before we move +on + + align:start position:0% + + + + align:start position:0% + +yes so these two quantities P1 P do uh + + align:start position:0% +yes so these two quantities P1 P do uh + + + align:start position:0% +yes so these two quantities P1 P do uh +cross product of the determinant of the + + align:start position:0% +cross product of the determinant of the + + + align:start position:0% +cross product of the determinant of the +three vectors they're always equal to + + align:start position:0% +three vectors they're always equal to + + + align:start position:0% +three vectors they're always equal to +each other okay they're always the same + + align:start position:0% +each other okay they're always the same + + + align:start position:0% +each other okay they're always the same +and now if the point is not in the plane + + align:start position:0% +and now if the point is not in the plane + + + align:start position:0% +and now if the point is not in the plane +then the numerical value will be non + + align:start position:0% +then the numerical value will be non + + + align:start position:0% +then the numerical value will be non +zero if p is in the plane it will be + + align:start position:0% + + + + align:start position:0% + +zero okay let's move on and talk a bit + + align:start position:0% +zero okay let's move on and talk a bit + + + align:start position:0% +zero okay let's move on and talk a bit +about matrices + + align:start position:0% + + + + align:start position:0% + +so probably some of you have seen about + + align:start position:0% +so probably some of you have seen about + + + align:start position:0% +so probably some of you have seen about +matrices a little bit in high school uh + + align:start position:0% +matrices a little bit in high school uh + + + align:start position:0% +matrices a little bit in high school uh +but certainly not all of you and so + + align:start position:0% +but certainly not all of you and so + + + align:start position:0% +but certainly not all of you and so +anyway let me just introduce you to a + + align:start position:0% +anyway let me just introduce you to a + + + align:start position:0% +anyway let me just introduce you to a +little bit about matrices just enough + + align:start position:0% +little bit about matrices just enough + + + align:start position:0% +little bit about matrices just enough +for what we'll need later in this class + + align:start position:0% +for what we'll need later in this class + + + align:start position:0% +for what we'll need later in this class +uh I should say if you want to know + + align:start position:0% +uh I should say if you want to know + + + align:start position:0% +uh I should say if you want to know +everything about the secret life of + + align:start position:0% +everything about the secret life of + + + align:start position:0% +everything about the secret life of +matrices when you should take 1806 + + align:start position:0% + + + + align:start position:0% + +someday so okay so what's going to be + + align:start position:0% +someday so okay so what's going to be + + + align:start position:0% +someday so okay so what's going to be +our motivation for matrices well in life + + align:start position:0% +our motivation for matrices well in life + + + align:start position:0% +our motivation for matrices well in life +a lot of things are related by linear + + align:start position:0% +a lot of things are related by linear + + + align:start position:0% +a lot of things are related by linear +formulas and even if they are not some + + align:start position:0% +formulas and even if they are not some + + + align:start position:0% +formulas and even if they are not some +maybe sometimes you can approximate them + + align:start position:0% +maybe sometimes you can approximate them + + + align:start position:0% +maybe sometimes you can approximate them +by linear formulas + + align:start position:0% + + + + align:start position:0% + +so often we have linear + + align:start position:0% + + + + align:start position:0% + +relations between variables + + align:start position:0% + + + + align:start position:0% + +and for + + align:start position:0% + + + + align:start position:0% + +example well if we if we do a change of + + align:start position:0% +example well if we if we do a change of + + + align:start position:0% +example well if we if we do a change of +coordinate + + align:start position:0% + + + + align:start position:0% + +systems so for example you know say + + align:start position:0% +systems so for example you know say + + + align:start position:0% +systems so for example you know say +that we're in + + align:start position:0% +that we're in + + + align:start position:0% +that we're in +space well and we have a point so its + + align:start position:0% +space well and we have a point so its + + + align:start position:0% +space well and we have a point so its +coordinates might be let me call them X1 + + align:start position:0% +coordinates might be let me call them X1 + + + align:start position:0% +coordinates might be let me call them X1 +X 2 X3 in my initial coordinate system + + align:start position:0% +X 2 X3 in my initial coordinate system + + + align:start position:0% +X 2 X3 in my initial coordinate system +but then maybe I need to actually switch + + align:start position:0% +but then maybe I need to actually switch + + + align:start position:0% +but then maybe I need to actually switch +to different coordinates to better solve + + align:start position:0% +to different coordinates to better solve + + + align:start position:0% +to different coordinates to better solve +my problem because it's more adapted to + + align:start position:0% +my problem because it's more adapted to + + + align:start position:0% +my problem because it's more adapted to +other things I will do in my problem and + + align:start position:0% +other things I will do in my problem and + + + align:start position:0% +other things I will do in my problem and +so I have other coordinate + + align:start position:0% +so I have other coordinate + + + align:start position:0% +so I have other coordinate +AES and then in these new + + align:start position:0% +AES and then in these new + + + align:start position:0% +AES and then in these new +coordinates well it will have actually + + align:start position:0% +coordinates well it will have actually + + + align:start position:0% +coordinates well it will have actually +different coordinates let me call them + + align:start position:0% +different coordinates let me call them + + + align:start position:0% +different coordinates let me call them +say U1 U2 + + align:start position:0% +say U1 U2 + + + align:start position:0% +say U1 U2 +u3 and then the relation between the old + + align:start position:0% +u3 and then the relation between the old + + + align:start position:0% +u3 and then the relation between the old +and the new coordinates is going to be + + align:start position:0% +and the new coordinates is going to be + + + align:start position:0% +and the new coordinates is going to be +by linear formulas + + align:start position:0% +by linear formulas + + + align:start position:0% +by linear formulas +I mean especially if I choose the same + + align:start position:0% +I mean especially if I choose the same + + + align:start position:0% +I mean especially if I choose the same +origin otherwise there might be constant + + align:start position:0% +origin otherwise there might be constant + + + align:start position:0% +origin otherwise there might be constant +terms + + align:start position:0% +terms + + + align:start position:0% +terms +which I will not insist + + align:start position:0% +which I will not insist + + + align:start position:0% +which I will not insist +on + + align:start position:0% +on + + + align:start position:0% +on +so let me just give an + + align:start position:0% + + + + align:start position:0% + +example for example maybe I don't + + align:start position:0% +example for example maybe I don't + + + align:start position:0% +example for example maybe I don't +know let's say for example U1 could be + + align:start position:0% +know let's say for example U1 could be + + + align:start position:0% +know let's say for example U1 could be +twice X1 + 3 * X2 Plus 3 * + + align:start position:0% +twice X1 + 3 * X2 Plus 3 * + + + align:start position:0% +twice X1 + 3 * X2 Plus 3 * +X3 U2 might be 2 * X1 + 4 * X2 + 5 * X3 + + align:start position:0% +X3 U2 might be 2 * X1 + 4 * X2 + 5 * X3 + + + align:start position:0% +X3 U2 might be 2 * X1 + 4 * X2 + 5 * X3 +u3 might be X1 + X2 + tce X3 do not ask + + align:start position:0% +u3 might be X1 + X2 + tce X3 do not ask + + + align:start position:0% +u3 might be X1 + X2 + tce X3 do not ask +me where these numbers come from I just + + align:start position:0% +me where these numbers come from I just + + + align:start position:0% +me where these numbers come from I just +made them up okay that's just an example + + align:start position:0% +made them up okay that's just an example + + + align:start position:0% +made them up okay that's just an example +of what might + + align:start position:0% +of what might + + + align:start position:0% +of what might +happen um so plug you know put here your + + align:start position:0% +happen um so plug you know put here your + + + align:start position:0% +happen um so plug you know put here your +favorite numbers if you + + align:start position:0% +favorite numbers if you + + + align:start position:0% +favorite numbers if you +want okay so + + align:start position:0% + + + + align:start position:0% + +now in order to express this kind of + + align:start position:0% +now in order to express this kind of + + + align:start position:0% +now in order to express this kind of +linear relation we can use matrices so a + + align:start position:0% +linear relation we can use matrices so a + + + align:start position:0% +linear relation we can use matrices so a +matrix is just a table with numbers in + + align:start position:0% +matrix is just a table with numbers in + + + align:start position:0% +matrix is just a table with numbers in +it + + align:start position:0% +it + + + align:start position:0% +it +and so we can reformulate + + align:start position:0% +and so we can reformulate + + + align:start position:0% +and so we can reformulate +this in terms of matrix + + align:start position:0% +this in terms of matrix + + + align:start position:0% +this in terms of matrix +multiplication or matrix + + align:start position:0% +multiplication or matrix + + + align:start position:0% +multiplication or matrix +product okay + + align:start position:0% +product okay + + + align:start position:0% +product okay +so instead of writing this I will write + + align:start position:0% +so instead of writing this I will write + + + align:start position:0% +so instead of writing this I will write +that The Matrix 2 3 3 2 4 + + align:start position:0% +that The Matrix 2 3 3 2 4 + + + align:start position:0% +that The Matrix 2 3 3 2 4 +5 1 1 + + align:start position:0% +5 1 1 + + + align:start position:0% +5 1 1 + + align:start position:0% + + + align:start position:0% +times the vector X1 X2 + + align:start position:0% +times the vector X1 X2 + + + align:start position:0% +times the vector X1 X2 +X3 is equal to U1 U2 + + align:start position:0% +X3 is equal to U1 U2 + + + align:start position:0% +X3 is equal to U1 U2 +u3 okay so hopefully you see that + + align:start position:0% +u3 okay so hopefully you see that + + + align:start position:0% +u3 okay so hopefully you see that +there's the same information content on + + align:start position:0% +there's the same information content on + + + align:start position:0% +there's the same information content on +both sides I just need to explain to you + + align:start position:0% +both sides I just need to explain to you + + + align:start position:0% +both sides I just need to explain to you +what this + + align:start position:0% +what this + + + align:start position:0% +what this +way of multiplying tables of numbers + + align:start position:0% + + + + align:start position:0% + +means well what it means is really that + + align:start position:0% +means well what it means is really that + + + align:start position:0% +means well what it means is really that +you know we take exactly these + + align:start position:0% +you know we take exactly these + + + align:start position:0% +you know we take exactly these +quantities + + align:start position:0% +quantities + + + align:start position:0% +quantities +but uh let me just say that more + + align:start position:0% +but uh let me just say that more + + + align:start position:0% +but uh let me just say that more +symbolically so maybe this Matrix we + + align:start position:0% +symbolically so maybe this Matrix we + + + align:start position:0% +symbolically so maybe this Matrix we +could call a you + + align:start position:0% +could call a you + + + align:start position:0% +could call a you +know and this we could call X and this + + align:start position:0% +know and this we could call X and this + + + align:start position:0% +know and this we could call X and this +we could call Capital U capital x then + + align:start position:0% +we could call Capital U capital x then + + + align:start position:0% +we could call Capital U capital x then +we'll say a * xal U which is is a lot + + align:start position:0% +we'll say a * xal U which is is a lot + + + align:start position:0% +we'll say a * xal U which is is a lot +shorter than that of course I need to + + align:start position:0% +shorter than that of course I need to + + + align:start position:0% +shorter than that of course I need to +tell you what a x and U are in terms of + + align:start position:0% +tell you what a x and U are in terms of + + + align:start position:0% +tell you what a x and U are in terms of +their entries for you to get the + + align:start position:0% +their entries for you to get the + + + align:start position:0% +their entries for you to get the +formula but it's convenient + + align:start position:0% +formula but it's convenient + + + align:start position:0% +formula but it's convenient +notation + + align:start position:0% +notation + + + align:start position:0% +notation +so what does it mean to do a matrix + + align:start position:0% +so what does it mean to do a matrix + + + align:start position:0% +so what does it mean to do a matrix +product + + align:start position:0% +product + + + align:start position:0% +product +so the + + align:start position:0% +so the + + + align:start position:0% +so the +entries in + + align:start position:0% + + + + align:start position:0% + +product so you should say so in the + + align:start position:0% +product so you should say so in the + + + align:start position:0% +product so you should say so in the +matrix product + + align:start position:0% +matrix product + + + align:start position:0% +matrix product +are obtained by doing the dot + + align:start position:0% +are obtained by doing the dot + + + align:start position:0% +are obtained by doing the dot +product so let's say we're doing the + + align:start position:0% +product so let's say we're doing the + + + align:start position:0% +product so let's say we're doing the +product + + align:start position:0% +product + + + align:start position:0% +product +ax so we do a DOT product + + align:start position:0% +ax so we do a DOT product + + + align:start position:0% +ax so we do a DOT product +between the rows dot products between + + align:start position:0% +between the rows dot products between + + + align:start position:0% +between the rows dot products between +the rows of + + align:start position:0% +the rows of + + + align:start position:0% +the rows of +a and The + + align:start position:0% + + + + align:start position:0% + +Columns of + + align:start position:0% + + + + align:start position:0% + +X so + + align:start position:0% +X so + + + align:start position:0% +X so +maybe I should say here a is a 3X3 + + align:start position:0% + + + + align:start position:0% + +Matrix that just means there's you know + + align:start position:0% +Matrix that just means there's you know + + + align:start position:0% +Matrix that just means there's you know +three rows and three columns and X is a + + align:start position:0% +three rows and three columns and X is a + + + align:start position:0% +three rows and three columns and X is a +column + + align:start position:0% + + + + align:start position:0% + +Vector which we can think of as a 3X one + + align:start position:0% +Vector which we can think of as a 3X one + + + align:start position:0% +Vector which we can think of as a 3X one +Matrix it has three rows and only one + + align:start position:0% +Matrix it has three rows and only one + + + align:start position:0% +Matrix it has three rows and only one +column okay so now what can we do well I + + align:start position:0% +column okay so now what can we do well I + + + align:start position:0% +column okay so now what can we do well I +said we're going to do the dot product + + align:start position:0% +said we're going to do the dot product + + + align:start position:0% +said we're going to do the dot product +between a row of a 2 3 3 and a column of + + align:start position:0% +between a row of a 2 3 3 and a column of + + + align:start position:0% +between a row of a 2 3 3 and a column of +X X1 X2 X3 well that dot product will be + + align:start position:0% +X X1 X2 X3 well that dot product will be + + + align:start position:0% +X X1 X2 X3 well that dot product will be +2 * X1 + 3 * X2 + 3 * X3 it's exactly + + align:start position:0% +2 * X1 + 3 * X2 + 3 * X3 it's exactly + + + align:start position:0% +2 * X1 + 3 * X2 + 3 * X3 it's exactly +what we want to set U Want equal to + + align:start position:0% +what we want to set U Want equal to + + + align:start position:0% +what we want to set U Want equal to +let's do the second one I take the + + align:start position:0% +let's do the second one I take the + + + align:start position:0% +let's do the second one I take the +second row of a 2 45 and I do the dot + + align:start position:0% +second row of a 2 45 and I do the dot + + + align:start position:0% +second row of a 2 45 and I do the dot +product with X1 X2 X3 I will get 2 * x1+ + + align:start position:0% +product with X1 X2 X3 I will get 2 * x1+ + + + align:start position:0% +product with X1 X2 X3 I will get 2 * x1+ +4 4 * X2 + 5 * X3 okay which is this + + align:start position:0% +4 4 * X2 + 5 * X3 okay which is this + + + align:start position:0% +4 4 * X2 + 5 * X3 okay which is this +thing and same with the third one 1 * X1 + + align:start position:0% +thing and same with the third one 1 * X1 + + + align:start position:0% +thing and same with the third one 1 * X1 ++ 1 * X2 + 2 * + + align:start position:0% + + + + align:start position:0% + +X3 okay so that's matrix + + align:start position:0% +X3 okay so that's matrix + + + align:start position:0% +X3 okay so that's matrix +multiplication + + align:start position:0% +multiplication + + + align:start position:0% +multiplication +so again I mean Let Me + + align:start position:0% +so again I mean Let Me + + + align:start position:0% +so again I mean Let Me +Maybe restate that more + + align:start position:0% + + + + align:start position:0% + +generally + + align:start position:0% +generally + + + align:start position:0% +generally +so if I want to find the + + align:start position:0% +so if I want to find the + + + align:start position:0% +so if I want to find the +entries of a product of two matrices A + + align:start position:0% +entries of a product of two matrices A + + + align:start position:0% +entries of a product of two matrices A +and B so I'm saying matrices but they + + align:start position:0% +and B so I'm saying matrices but they + + + align:start position:0% +and B so I'm saying matrices but they +could be of course vectors are now a + + align:start position:0% +could be of course vectors are now a + + + align:start position:0% +could be of course vectors are now a +special case of matrices just by taking + + align:start position:0% +special case of matrices just by taking + + + align:start position:0% +special case of matrices just by taking +a matrix of width + + align:start position:0% +a matrix of width + + + align:start position:0% +a matrix of width +one okay + + align:start position:0% +one okay + + + align:start position:0% +one okay +so if I have my Matrix + + align:start position:0% +so if I have my Matrix + + + align:start position:0% +so if I have my Matrix +a and I have my Matrix + + align:start position:0% + + + + align:start position:0% + +B and then I will get the product + + align:start position:0% +B and then I will get the product + + + align:start position:0% +B and then I will get the product +AB well let's say for example that a you + + align:start position:0% +AB well let's say for example that a you + + + align:start position:0% +AB well let's say for example that a you +know this works in any sizes so let's + + align:start position:0% +know this works in any sizes so let's + + + align:start position:0% +know this works in any sizes so let's +say that a is a four sorry a 3x4 matrix + + align:start position:0% +say that a is a four sorry a 3x4 matrix + + + align:start position:0% +say that a is a four sorry a 3x4 matrix +so it has three rows four columns and + + align:start position:0% +so it has three rows four columns and + + + align:start position:0% +so it has three rows four columns and +here I'm not going to give you the + + align:start position:0% +here I'm not going to give you the + + + align:start position:0% +here I'm not going to give you the +values because I'm not going to compute + + align:start position:0% +values because I'm not going to compute + + + align:start position:0% +values because I'm not going to compute +everything it would take you know the + + align:start position:0% +everything it would take you know the + + + align:start position:0% +everything it would take you know the +rest of the lecture so and let's say + + align:start position:0% +rest of the lecture so and let's say + + + align:start position:0% +rest of the lecture so and let's say +that b is maybe size 4X two so it has + + align:start position:0% +that b is maybe size 4X two so it has + + + align:start position:0% +that b is maybe size 4X two so it has +two columns and four rows and let's say + + align:start position:0% +two columns and four rows and let's say + + + align:start position:0% +two columns and four rows and let's say +for example that we have the second + + align:start position:0% +for example that we have the second + + + align:start position:0% +for example that we have the second +column is 03 + + align:start position:0% +column is 03 + + + align:start position:0% +column is 03 +02 so a * B I claim will have well the + + align:start position:0% +02 so a * B I claim will have well the + + + align:start position:0% +02 so a * B I claim will have well the +entries should be the dot products + + align:start position:0% +entries should be the dot products + + + align:start position:0% +entries should be the dot products +between these rows and these columns + + align:start position:0% +between these rows and these columns + + + align:start position:0% +between these rows and these columns +here we have two columns here we have + + align:start position:0% +here we have two columns here we have + + + align:start position:0% +here we have two columns here we have +three rows so we should get you know + + align:start position:0% +three rows so we should get you know + + + align:start position:0% +three rows so we should get you know +three times two different possibilities + + align:start position:0% +three times two different possibilities + + + align:start position:0% +three times two different possibilities +and so the answer will have size 3x + + align:start position:0% +and so the answer will have size 3x + + + align:start position:0% +and so the answer will have size 3x +two okay and well we cannot compute most + + align:start position:0% +two okay and well we cannot compute most + + + align:start position:0% +two okay and well we cannot compute most +of them because I didn't give you + + align:start position:0% +of them because I didn't give you + + + align:start position:0% +of them because I didn't give you +numbers but one of them we can compute + + align:start position:0% +numbers but one of them we can compute + + + align:start position:0% +numbers but one of them we can compute +we can compute the one that goes here + + align:start position:0% +we can compute the one that goes here + + + align:start position:0% +we can compute the one that goes here +namely this one in the second column so + + align:start position:0% +namely this one in the second column so + + + align:start position:0% +namely this one in the second column so +I select the second column of B and in + + align:start position:0% +I select the second column of B and in + + + align:start position:0% +I select the second column of B and in +the first row so I take the first row of + + align:start position:0% +the first row so I take the first row of + + + align:start position:0% +the first row so I take the first row of +a and I find well 1 * 0 0 2 * 3 6 + 0 + + + align:start position:0% +a and I find well 1 * 0 0 2 * 3 6 + 0 + + + + align:start position:0% +a and I find well 1 * 0 0 2 * 3 6 + 0 + +8 should make 14 so this entry here is + + align:start position:0% +8 should make 14 so this entry here is + + + align:start position:0% +8 should make 14 so this entry here is +14 okay + + align:start position:0% +14 okay + + + align:start position:0% +14 okay +so in fact let me tell you about another + + align:start position:0% +so in fact let me tell you about another + + + align:start position:0% +so in fact let me tell you about another +way to set it up so that you remember + + align:start position:0% +way to set it up so that you remember + + + align:start position:0% +way to set it up so that you remember +more easily how you know what goes + + align:start position:0% + + + + align:start position:0% + +where so one way that you can set it up + + align:start position:0% +where so one way that you can set it up + + + align:start position:0% +where so one way that you can set it up +is you can put a + + align:start position:0% +is you can put a + + + align:start position:0% +is you can put a +here you can put B up here and then you + + align:start position:0% +here you can put B up here and then you + + + align:start position:0% +here you can put B up here and then you +will get the answer + + align:start position:0% + + + + align:start position:0% + +here and if you want to find what goes + + align:start position:0% +here and if you want to find what goes + + + align:start position:0% +here and if you want to find what goes +in a given slot here then you just look + + align:start position:0% +in a given slot here then you just look + + + align:start position:0% +in a given slot here then you just look +to its left and you look above it and + + align:start position:0% +to its left and you look above it and + + + align:start position:0% +to its left and you look above it and +you do the dot product between these + + align:start position:0% +you do the dot product between these + + + align:start position:0% +you do the dot product between these +guys okay so that's I think an easy way + + align:start position:0% +guys okay so that's I think an easy way + + + align:start position:0% +guys okay so that's I think an easy way +to remember you know first of all it + + align:start position:0% +to remember you know first of all it + + + align:start position:0% +to remember you know first of all it +tells you what the size of the answer + + align:start position:0% +tells you what the size of the answer + + + align:start position:0% +tells you what the size of the answer +will be the size will be well what fits + + align:start position:0% +will be the size will be well what fits + + + align:start position:0% +will be the size will be well what fits +nicely in this box should have the same + + align:start position:0% +nicely in this box should have the same + + + align:start position:0% +nicely in this box should have the same +width as B and the same height as a and + + align:start position:0% +width as B and the same height as a and + + + align:start position:0% +width as B and the same height as a and +second it tells you which product to + + align:start position:0% +second it tells you which product to + + + align:start position:0% +second it tells you which product to +compute for each + + align:start position:0% +compute for each + + + align:start position:0% +compute for each +position okay so you just look at what's + + align:start position:0% +position okay so you just look at what's + + + align:start position:0% +position okay so you just look at what's +to the left and what's above the given + + align:start position:0% +to the left and what's above the given + + + align:start position:0% +to the left and what's above the given +position now now there's a catch can we + + align:start position:0% +position now now there's a catch can we + + + align:start position:0% +position now now there's a catch can we +multiply anything by anything well no + + align:start position:0% +multiply anything by anything well no + + + align:start position:0% +multiply anything by anything well no +okay I mean I wouldn't ask the question + + align:start position:0% +okay I mean I wouldn't ask the question + + + align:start position:0% +okay I mean I wouldn't ask the question +otherwise but but anyway uh see to be + + align:start position:0% +otherwise but but anyway uh see to be + + + align:start position:0% +otherwise but but anyway uh see to be +able to do this dot product we need to + + align:start position:0% +able to do this dot product we need to + + + align:start position:0% +able to do this dot product we need to +have the same number of entries here and + + align:start position:0% +have the same number of entries here and + + + align:start position:0% +have the same number of entries here and +here otherwise we can't say take this + + align:start position:0% +here otherwise we can't say take this + + + align:start position:0% +here otherwise we can't say take this +time that plus this time that and so on + + align:start position:0% +time that plus this time that and so on + + + align:start position:0% +time that plus this time that and so on +if we run out of space on one of them + + align:start position:0% +if we run out of space on one of them + + + align:start position:0% +if we run out of space on one of them +before the + + align:start position:0% +before the + + + align:start position:0% +before the +other + + align:start position:0% + + + + align:start position:0% + +so the condition and it's kind of + + align:start position:0% +so the condition and it's kind of + + + align:start position:0% +so the condition and it's kind of +important so let me write it in right + + align:start position:0% + + + + align:start position:0% + +is that the width of + + align:start position:0% +is that the width of + + + align:start position:0% +is that the width of +a + + align:start position:0% +a + + + align:start position:0% +a +must + + align:start position:0% +must + + + align:start position:0% +must +equal the height of + + align:start position:0% + + + + align:start position:0% + +B okay sorry it's a bit cluttered but + + align:start position:0% +B okay sorry it's a bit cluttered but + + + align:start position:0% +B okay sorry it's a bit cluttered but +hopefully you can still see what I'm + + align:start position:0% +hopefully you can still see what I'm + + + align:start position:0% +hopefully you can still see what I'm +fighting + + align:start position:0% + + + + align:start position:0% + +so okay okay but now we know how to + + align:start position:0% +so okay okay but now we know how to + + + align:start position:0% +so okay okay but now we know how to +multiply + + align:start position:0% + + + + align:start position:0% + +matrices so what does it mean to + + align:start position:0% +matrices so what does it mean to + + + align:start position:0% +matrices so what does it mean to +multiply matrices I mean of + + align:start position:0% +multiply matrices I mean of + + + align:start position:0% +multiply matrices I mean of +course we've seen uh you know on this + + align:start position:0% +course we've seen uh you know on this + + + align:start position:0% +course we've seen uh you know on this +example that we can use the Matrix to + + align:start position:0% +example that we can use the Matrix to + + + align:start position:0% +example that we can use the Matrix to +tell us how to transform from X's to + + align:start position:0% +tell us how to transform from X's to + + + align:start position:0% +tell us how to transform from X's to +use and that's an example of + + align:start position:0% +use and that's an example of + + + align:start position:0% +use and that's an example of +multiplication but now let's say that we + + align:start position:0% +multiplication but now let's say that we + + + align:start position:0% +multiplication but now let's say that we +have two matrices like that telling us + + align:start position:0% +have two matrices like that telling us + + + align:start position:0% +have two matrices like that telling us +how to transform from something to + + align:start position:0% +how to transform from something to + + + align:start position:0% +how to transform from something to +something else what does it mean to + + align:start position:0% +something else what does it mean to + + + align:start position:0% +something else what does it mean to +multiply + + align:start position:0% +multiply + + + align:start position:0% +multiply +them + + align:start position:0% + + + + align:start position:0% + +so I + + align:start position:0% +so I + + + align:start position:0% +so I +claim is that so I claim that the + + align:start position:0% +claim is that so I claim that the + + + align:start position:0% +claim is that so I claim that the +product AB + + align:start position:0% +product AB + + + align:start position:0% +product AB +represents doing first the + + align:start position:0% + + + + align:start position:0% + +transformation B + + align:start position:0% +transformation B + + + align:start position:0% +transformation B +then trans formation + + align:start position:0% + + + + align:start position:0% + +a so that's a slightly counterintuitive + + align:start position:0% +a so that's a slightly counterintuitive + + + align:start position:0% +a so that's a slightly counterintuitive +thing because we're used to writing + + align:start position:0% +thing because we're used to writing + + + align:start position:0% +thing because we're used to writing +things from left to right uh + + align:start position:0% +things from left to right uh + + + align:start position:0% +things from left to right uh +unfortunately with matrices the way + + align:start position:0% +unfortunately with matrices the way + + + align:start position:0% +unfortunately with matrices the way +they're done you multipy I mean you + + align:start position:0% +they're done you multipy I mean you + + + align:start position:0% +they're done you multipy I mean you +multiply things from right to left if + + align:start position:0% +multiply things from right to left if + + + align:start position:0% +multiply things from right to left if +you think about it you know when you + + align:start position:0% +you think about it you know when you + + + align:start position:0% +you think about it you know when you +write say you have two functions f and g + + align:start position:0% +write say you have two functions f and g + + + align:start position:0% +write say you have two functions f and g +you write F of G of X it really means + + align:start position:0% +you write F of G of X it really means + + + align:start position:0% +you write F of G of X it really means +you apply first G then F so it works the + + align:start position:0% +you apply first G then F so it works the + + + align:start position:0% +you apply first G then F so it works the +same way as that + + align:start position:0% +same way as that + + + align:start position:0% +same way as that +okay so why why is this well if I write + + align:start position:0% +okay so why why is this well if I write + + + align:start position:0% +okay so why why is this well if I write +AB * X where X is some Vector that I + + align:start position:0% +AB * X where X is some Vector that I + + + align:start position:0% +AB * X where X is some Vector that I +want to transform it's the same as a * + + align:start position:0% +want to transform it's the same as a * + + + align:start position:0% +want to transform it's the same as a * +BX okay so this property is called + + align:start position:0% +BX okay so this property is called + + + align:start position:0% +BX okay so this property is called +associativity and it's a good property + + align:start position:0% +associativity and it's a good property + + + align:start position:0% +associativity and it's a good property +of well behaved products uh not of cross + + align:start position:0% +of well behaved products uh not of cross + + + align:start position:0% +of well behaved products uh not of cross +product by the way but so matrix product + + align:start position:0% +product by the way but so matrix product + + + align:start position:0% +product by the way but so matrix product +is + + align:start position:0% +is + + + align:start position:0% +is +associative that means we can actually + + align:start position:0% +associative that means we can actually + + + align:start position:0% +associative that means we can actually +think of a product ax and multiply them + + align:start position:0% +think of a product ax and multiply them + + + align:start position:0% +think of a product ax and multiply them +in whichever order we want we can start + + align:start position:0% +in whichever order we want we can start + + + align:start position:0% +in whichever order we want we can start +with BX or we can start with + + align:start position:0% +with BX or we can start with + + + align:start position:0% +with BX or we can start with +a so + + align:start position:0% +a so + + + align:start position:0% +a so +now BX means we apply the transformation + + align:start position:0% +now BX means we apply the transformation + + + align:start position:0% +now BX means we apply the transformation +B to X and then multiplying by a means + + align:start position:0% +B to X and then multiplying by a means + + + align:start position:0% +B to X and then multiplying by a means +we apply the transformation + + align:start position:0% +we apply the transformation + + + align:start position:0% +we apply the transformation +a so we first apply B then we apply a + + align:start position:0% +a so we first apply B then we apply a + + + align:start position:0% +a so we first apply B then we apply a +that's the same as applying a all at + + align:start position:0% + + + + align:start position:0% + +once + + align:start position:0% +once + + + align:start position:0% +once +Okay so + + align:start position:0% + + + + align:start position:0% + +another note of warning is that ab and + + align:start position:0% +another note of warning is that ab and + + + align:start position:0% +another note of warning is that ab and +ba are not the same thing at all well I + + align:start position:0% +ba are not the same thing at all well I + + + align:start position:0% +ba are not the same thing at all well I +mean you probably see that already from + + align:start position:0% +mean you probably see that already from + + + align:start position:0% +mean you probably see that already from +this interpretation it's not the same + + align:start position:0% +this interpretation it's not the same + + + align:start position:0% +this interpretation it's not the same +thing to you know convert oranges to + + align:start position:0% +thing to you know convert oranges to + + + align:start position:0% +thing to you know convert oranges to +bananas then to carrots or vice versa + + align:start position:0% +bananas then to carrots or vice versa + + + align:start position:0% +bananas then to carrots or vice versa +um uh on the other + + align:start position:0% +um uh on the other + + + align:start position:0% +um uh on the other +hand well I mean actually even worse + + align:start position:0% +hand well I mean actually even worse + + + align:start position:0% +hand well I mean actually even worse +this thing might not can be well defined + + align:start position:0% +this thing might not can be well defined + + + align:start position:0% +this thing might not can be well defined +because you know if the + + align:start position:0% +because you know if the + + + align:start position:0% +because you know if the +height of sorry the width of a equals + + align:start position:0% +height of sorry the width of a equals + + + align:start position:0% +height of sorry the width of a equals +the height of B we can do this product + + align:start position:0% +the height of B we can do this product + + + align:start position:0% +the height of B we can do this product +but we we don't necessarily I mean it's + + align:start position:0% +but we we don't necessarily I mean it's + + + align:start position:0% +but we we don't necessarily I mean it's +not clear that the width of B will equal + + align:start position:0% +not clear that the width of B will equal + + + align:start position:0% +not clear that the width of B will equal +the height of of a which is what we + + align:start position:0% +the height of of a which is what we + + + align:start position:0% +the height of of a which is what we +would need for that + + align:start position:0% +would need for that + + + align:start position:0% +would need for that +one okay so you know the size condition + + align:start position:0% +one okay so you know the size condition + + + align:start position:0% +one okay so you know the size condition +to be able to do the product might not + + align:start position:0% +to be able to do the product might not + + + align:start position:0% +to be able to do the product might not +make sense actually maybe one of them + + align:start position:0% +make sense actually maybe one of them + + + align:start position:0% +make sense actually maybe one of them +doesn't even make sense even if they + + align:start position:0% +doesn't even make sense even if they + + + align:start position:0% +doesn't even make sense even if they +both make sense they're usually complet + + align:start position:0% +both make sense they're usually complet + + + align:start position:0% +both make sense they're usually complet +different + + align:start position:0% + + + + align:start position:0% + +things okay the next thing I need to + + align:start position:0% +things okay the next thing I need to + + + align:start position:0% +things okay the next thing I need to +tell you is something called the + + align:start position:0% +tell you is something called the + + + align:start position:0% +tell you is something called the +identity + + align:start position:0% + + + + align:start position:0% + +Matrix well the identity Matrix is the + + align:start position:0% +Matrix well the identity Matrix is the + + + align:start position:0% +Matrix well the identity Matrix is the +Matrix that does nothing okay so what + + align:start position:0% +Matrix that does nothing okay so what + + + align:start position:0% +Matrix that does nothing okay so what +does it mean to do nothing I don't mean + + align:start position:0% +does it mean to do nothing I don't mean + + + align:start position:0% +does it mean to do nothing I don't mean +the Matrix Zero The Matrix zero would + + align:start position:0% +the Matrix Zero The Matrix zero would + + + align:start position:0% +the Matrix Zero The Matrix zero would +take X and would always give you back + + align:start position:0% +take X and would always give you back + + + align:start position:0% +take X and would always give you back +zero that's not very interesting + + align:start position:0% +zero that's not very interesting + + + align:start position:0% +zero that's not very interesting +transformation um what I mean is the guy + + align:start position:0% +transformation um what I mean is the guy + + + align:start position:0% +transformation um what I mean is the guy +that takes X and gives you X again so it + + align:start position:0% +that takes X and gives you X again so it + + + align:start position:0% +that takes X and gives you X again so it +satisfies you know property I so it's + + align:start position:0% +satisfies you know property I so it's + + + align:start position:0% +satisfies you know property I so it's +called I and it has a property that IX + + align:start position:0% +called I and it has a property that IX + + + align:start position:0% +called I and it has a property that IX +equals X for all X so it's the + + align:start position:0% +equals X for all X so it's the + + + align:start position:0% +equals X for all X so it's the +transformation from something to itself + + align:start position:0% +transformation from something to itself + + + align:start position:0% +transformation from something to itself +it's the obvious transformation called + + align:start position:0% +it's the obvious transformation called + + + align:start position:0% +it's the obvious transformation called +the identity + + align:start position:0% +the identity + + + align:start position:0% +the identity +transformation so how do we write that + + align:start position:0% +transformation so how do we write that + + + align:start position:0% +transformation so how do we write that +as a + + align:start position:0% +as a + + + align:start position:0% +as a +matrix well so actually there's an + + align:start position:0% +matrix well so actually there's an + + + align:start position:0% +matrix well so actually there's an +identity for each size you know because + + align:start position:0% +identity for each size you know because + + + align:start position:0% +identity for each size you know because +of course depending on whether X has two + + align:start position:0% +of course depending on whether X has two + + + align:start position:0% +of course depending on whether X has two +entries or 10 entries uh The Matrix I + + align:start position:0% +entries or 10 entries uh The Matrix I + + + align:start position:0% +entries or 10 entries uh The Matrix I +needs to have a different + + align:start position:0% +needs to have a different + + + align:start position:0% +needs to have a different +size + + align:start position:0% +size + + + align:start position:0% +size +so for example the identity Matrix of + + align:start position:0% +so for example the identity Matrix of + + + align:start position:0% +so for example the identity Matrix of +size + + align:start position:0% +size + + + align:start position:0% +size +3x3 has entries one one one on the + + align:start position:0% +3x3 has entries one one one on the + + + align:start position:0% +3x3 has entries one one one on the +diagonal and Zer everywhere + + align:start position:0% +diagonal and Zer everywhere + + + align:start position:0% +diagonal and Zer everywhere +else okay let's check if we multiply + + align:start position:0% +else okay let's check if we multiply + + + align:start position:0% +else okay let's check if we multiply +this with a vector well okay maybe I + + align:start position:0% +this with a vector well okay maybe I + + + align:start position:0% +this with a vector well okay maybe I +should do that on a separate board + + align:start position:0% +should do that on a separate board + + + align:start position:0% +should do that on a separate board +but so start thinking about it what + + align:start position:0% +but so start thinking about it what + + + align:start position:0% +but so start thinking about it what +happens when I multiply this with a + + align:start position:0% +happens when I multiply this with a + + + align:start position:0% +happens when I multiply this with a +vector X + + align:start position:0% + + + + align:start position:0% + +okay so let's say I + + align:start position:0% +okay so let's say I + + + align:start position:0% +okay so let's say I +multiply The + + align:start position:0% +multiply The + + + align:start position:0% +multiply The +Matrix + + align:start position:0% + + + + align:start position:0% + +I with a vector X1 X2 + + align:start position:0% +I with a vector X1 X2 + + + align:start position:0% +I with a vector X1 X2 +X3 well what will be the first + + align:start position:0% +X3 well what will be the first + + + align:start position:0% +X3 well what will be the first +entry it will be the dot product between + + align:start position:0% +entry it will be the dot product between + + + align:start position:0% +entry it will be the dot product between +1 0 0 and X1 X2 X3 if you want this + + align:start position:0% +1 0 0 and X1 X2 X3 if you want this + + + align:start position:0% +1 0 0 and X1 X2 X3 if you want this +Vector is I hat okay so if you do the + + align:start position:0% +Vector is I hat okay so if you do the + + + align:start position:0% +Vector is I hat okay so if you do the +dot product with IH hat you will get the + + align:start position:0% +dot product with IH hat you will get the + + + align:start position:0% +dot product with IH hat you will get the +X component you will get the first + + align:start position:0% +X component you will get the first + + + align:start position:0% +X component you will get the first +component that will be X1 1 * X1 + 0 0 + + align:start position:0% +component that will be X1 1 * X1 + 0 0 + + + align:start position:0% +component that will be X1 1 * X1 + 0 0 +similarly here if I do the dot product I + + align:start position:0% +similarly here if I do the dot product I + + + align:start position:0% +similarly here if I do the dot product I +get 0 + X2 + z i get x2 and here I get + + align:start position:0% +get 0 + X2 + z i get x2 and here I get + + + align:start position:0% +get 0 + X2 + z i get x2 and here I get +X3 okay it + + align:start position:0% +X3 okay it + + + align:start position:0% +X3 okay it +works same thing if I put here a matrix + + align:start position:0% +works same thing if I put here a matrix + + + align:start position:0% +works same thing if I put here a matrix +I will get back the same + + align:start position:0% +I will get back the same + + + align:start position:0% +I will get back the same +Matrix now of + + align:start position:0% +Matrix now of + + + align:start position:0% +Matrix now of +course okay so in + + align:start position:0% + + + + align:start position:0% + +general the identity Matrix in size n + + align:start position:0% +general the identity Matrix in size n + + + align:start position:0% +general the identity Matrix in size n +byn + + align:start position:0% +byn + + + align:start position:0% +byn +so it's an N byn thing with ones on the + + align:start position:0% +so it's an N byn thing with ones on the + + + align:start position:0% +so it's an N byn thing with ones on the +diagonal and Zer everywhere + + align:start position:0% +diagonal and Zer everywhere + + + align:start position:0% +diagonal and Zer everywhere +else okay you just put one at every + + align:start position:0% +else okay you just put one at every + + + align:start position:0% +else okay you just put one at every +diagonal position and zero elsewhere and + + align:start position:0% +diagonal position and zero elsewhere and + + + align:start position:0% +diagonal position and zero elsewhere and +then you can see if you multiply that by + + align:start position:0% +then you can see if you multiply that by + + + align:start position:0% +then you can see if you multiply that by +a vector you will get the same Vector + + align:start position:0% + + + + align:start position:0% + +back + + align:start position:0% + + + + align:start position:0% + +okay oh + + align:start position:0% + + + + align:start position:0% + +okay uh let me give you another example + + align:start position:0% +okay uh let me give you another example + + + align:start position:0% +okay uh let me give you another example +of a + + align:start position:0% + + + + align:start position:0% + +matrix let's say that in the + + align:start position:0% + + + + align:start position:0% + +plane we look at the transformation that + + align:start position:0% +plane we look at the transformation that + + + align:start position:0% +plane we look at the transformation that +does + + align:start position:0% +does + + + align:start position:0% +does +Rotation by + + align:start position:0% +Rotation by + + + align:start position:0% +Rotation by +90° uh let's + + align:start position:0% +90° uh let's + + + align:start position:0% +90° uh let's +say counterclockwise + + align:start position:0% + + + + align:start position:0% + +so I claim that this is given by The + + align:start position:0% +so I claim that this is given by The + + + align:start position:0% +so I claim that this is given by The +Matrix 0 1 - 1 0 so let's try to see why + + align:start position:0% +Matrix 0 1 - 1 0 so let's try to see why + + + align:start position:0% +Matrix 0 1 - 1 0 so let's try to see why +that is the + + align:start position:0% + + + + align:start position:0% + +case well if I do R * I hat so if I + + align:start position:0% +case well if I do R * I hat so if I + + + align:start position:0% +case well if I do R * I hat so if I +apply that to the first vector + + align:start position:0% +apply that to the first vector + + + align:start position:0% +apply that to the first vector +IH hat so that means + + align:start position:0% +IH hat so that means + + + align:start position:0% +IH hat so that means +okay IH hat will be one + + align:start position:0% +okay IH hat will be one + + + align:start position:0% +okay IH hat will be one +Z this product well here you will get + + align:start position:0% +Z this product well here you will get + + + align:start position:0% +Z this product well here you will get +zero and then you will get + + align:start position:0% +zero and then you will get + + + align:start position:0% +zero and then you will get +one you get J + + align:start position:0% + + + + align:start position:0% + +hat okay so this thing + + align:start position:0% +hat okay so this thing + + + align:start position:0% +hat okay so this thing +sends IH hat to + + align:start position:0% +sends IH hat to + + + align:start position:0% +sends IH hat to +jut what about Jad + + align:start position:0% + + + + align:start position:0% + +well you + + align:start position:0% +well you + + + align:start position:0% +well you +get1 and then you get zero so that's + + align:start position:0% +get1 and then you get zero so that's + + + align:start position:0% +get1 and then you get zero so that's +minus I so J is sent towards here and in + + align:start position:0% +minus I so J is sent towards here and in + + + align:start position:0% +minus I so J is sent towards here and in +general if you apply it to a vector with + + align:start position:0% +general if you apply it to a vector with + + + align:start position:0% +general if you apply it to a vector with +coordinates XY with components XY then + + align:start position:0% +coordinates XY with components XY then + + + align:start position:0% +coordinates XY with components XY then +you will get back uh minus YX which is + + align:start position:0% +you will get back uh minus YX which is + + + align:start position:0% +you will get back uh minus YX which is +the formula we've seen for rotating a + + align:start position:0% +the formula we've seen for rotating a + + + align:start position:0% +the formula we've seen for rotating a +vector by 90° + + align:start position:0% + + + + align:start position:0% + +so it seems to do what we + + align:start position:0% +so it seems to do what we + + + align:start position:0% +so it seems to do what we +want uh by the way I should point out so + + align:start position:0% +want uh by the way I should point out so + + + align:start position:0% +want uh by the way I should point out so +the columns in this Matrix represent + + align:start position:0% +the columns in this Matrix represent + + + align:start position:0% +the columns in this Matrix represent +what happens to each basis Vector to the + + align:start position:0% +what happens to each basis Vector to the + + + align:start position:0% +what happens to each basis Vector to the +vectors I and J see what I mean this guy + + align:start position:0% +vectors I and J see what I mean this guy + + + align:start position:0% +vectors I and J see what I mean this guy +here is exactly what we get when we + + align:start position:0% +here is exactly what we get when we + + + align:start position:0% +here is exactly what we get when we +multiply R by I and when when we + + align:start position:0% +multiply R by I and when when we + + + align:start position:0% +multiply R by I and when when we +multiply R by J we get this guy + + align:start position:0% + + + + align:start position:0% + +here so what's interesting about this + + align:start position:0% +here so what's interesting about this + + + align:start position:0% +here so what's interesting about this +Matrix well we can do computations with + + align:start position:0% +Matrix well we can do computations with + + + align:start position:0% +Matrix well we can do computations with +matrices in ways that are easier than + + align:start position:0% +matrices in ways that are easier than + + + align:start position:0% +matrices in ways that are easier than +writing coordinate change formulas for + + align:start position:0% +writing coordinate change formulas for + + + align:start position:0% +writing coordinate change formulas for +example if you compute R squ so if you + + align:start position:0% +example if you compute R squ so if you + + + align:start position:0% +example if you compute R squ so if you +multiply r with + + align:start position:0% +multiply r with + + + align:start position:0% +multiply r with +itself well I let you do it as an + + align:start position:0% +itself well I let you do it as an + + + align:start position:0% +itself well I let you do it as an +exercise but you will find that you get + + align:start position:0% +exercise but you will find that you get + + + align:start position:0% +exercise but you will find that you get +minus1 - 1 0 0 so that's minus the + + align:start position:0% +minus1 - 1 0 0 so that's minus the + + + align:start position:0% +minus1 - 1 0 0 so that's minus the +identity + + align:start position:0% +identity + + + align:start position:0% +identity +Matrix why is that well if I rotate + + align:start position:0% +Matrix why is that well if I rotate + + + align:start position:0% +Matrix why is that well if I rotate +something by 90° and then I rotate by + + align:start position:0% +something by 90° and then I rotate by + + + align:start position:0% +something by 90° and then I rotate by +90° again then I will rotate by 180° + + align:start position:0% +90° again then I will rotate by 180° + + + align:start position:0% +90° again then I will rotate by 180° +that means I will actually just go to + + align:start position:0% +that means I will actually just go to + + + align:start position:0% +that means I will actually just go to +the opposite Point around the origin so + + align:start position:0% +the opposite Point around the origin so + + + align:start position:0% +the opposite Point around the origin so +I will take X Y to - xus + + align:start position:0% +I will take X Y to - xus + + + align:start position:0% +I will take X Y to - xus +y + + align:start position:0% +y + + + align:start position:0% +y +okay and if I applied r four * R to 4 + + align:start position:0% +okay and if I applied r four * R to 4 + + + align:start position:0% +okay and if I applied r four * R to 4 +would be identity + + align:start position:0% + + + + align:start position:0% + +okay um questions yes came for matx is + + align:start position:0% +okay um questions yes came for matx is + + + align:start position:0% +okay um questions yes came for matx is +that r + + align:start position:0% +that r + + + align:start position:0% +that r +or Ah that's a very good question so how + + align:start position:0% +or Ah that's a very good question so how + + + align:start position:0% +or Ah that's a very good question so how +did I come up with this R well secretly + + align:start position:0% +did I come up with this R well secretly + + + align:start position:0% +did I come up with this R well secretly +I worked pretty hard to find what are + + align:start position:0% +I worked pretty hard to find what are + + + align:start position:0% +I worked pretty hard to find what are +the entries that would tell me how to + + align:start position:0% +the entries that would tell me how to + + + align:start position:0% +the entries that would tell me how to +rotate something by 90 degrees + + align:start position:0% +rotate something by 90 degrees + + + align:start position:0% +rotate something by 90 degrees +counterclockwise so remember I mean I + + align:start position:0% +counterclockwise so remember I mean I + + + align:start position:0% +counterclockwise so remember I mean I +should have said um what we saw I think + + align:start position:0% +should have said um what we saw I think + + + align:start position:0% +should have said um what we saw I think +last time or the first lecture is that + + align:start position:0% +last time or the first lecture is that + + + align:start position:0% +last time or the first lecture is that +to rotate a vector by + + align:start position:0% +to rotate a vector by + + + align:start position:0% +to rotate a vector by +90° we should change XY + + align:start position:0% +90° we should change XY + + + align:start position:0% +90° we should change XY +to minus + + align:start position:0% + + + + align:start position:0% + +YX okay and so now I'm trying to express + + align:start position:0% +YX okay and so now I'm trying to express + + + align:start position:0% +YX okay and so now I'm trying to express +the this transformation as a matrix and + + align:start position:0% +the this transformation as a matrix and + + + align:start position:0% +the this transformation as a matrix and +if you work out you know how these guys + + align:start position:0% +if you work out you know how these guys + + + align:start position:0% +if you work out you know how these guys +so maybe you want to call these guys u + + align:start position:0% +so maybe you want to call these guys u + + + align:start position:0% +so maybe you want to call these guys u +and v and if you write U equals 0x - 1 y + + align:start position:0% +and v and if you write U equals 0x - 1 y + + + align:start position:0% +and v and if you write U equals 0x - 1 y +0x - 1 Y and then V = 1x + 0 y 1 x + 0 y + + align:start position:0% +0x - 1 Y and then V = 1x + 0 y 1 x + 0 y + + + align:start position:0% +0x - 1 Y and then V = 1x + 0 y 1 x + 0 y +okay so that's how I would find it uh + + align:start position:0% +okay so that's how I would find it uh + + + align:start position:0% +okay so that's how I would find it uh +here actually I just gave it to you you + + align:start position:0% +here actually I just gave it to you you + + + align:start position:0% +here actually I just gave it to you you +know ready made so you didn't really see + + align:start position:0% +know ready made so you didn't really see + + + align:start position:0% +know ready made so you didn't really see +how I how I found + + align:start position:0% + + + + align:start position:0% + +it uh you will see more about rotations + + align:start position:0% +it uh you will see more about rotations + + + align:start position:0% +it uh you will see more about rotations +on the problem on the problem set + + align:start position:0% +on the problem on the problem set + + + align:start position:0% +on the problem on the problem set +there so you're going to see more about + + align:start position:0% +there so you're going to see more about + + + align:start position:0% +there so you're going to see more about +these things + + align:start position:0% + + + + align:start position:0% + +okay uh so next I need to tell you how + + align:start position:0% +okay uh so next I need to tell you how + + + align:start position:0% +okay uh so next I need to tell you how +to invert matrices so what's the point + + align:start position:0% +to invert matrices so what's the point + + + align:start position:0% +to invert matrices so what's the point +of matrices it's that it gives us a nice + + align:start position:0% +of matrices it's that it gives us a nice + + + align:start position:0% +of matrices it's that it gives us a nice +way to think about these changes of + + align:start position:0% +way to think about these changes of + + + align:start position:0% +way to think about these changes of +variables and in particular if we know + + align:start position:0% +variables and in particular if we know + + + align:start position:0% +variables and in particular if we know +how to express u in terms of X maybe + + align:start position:0% +how to express u in terms of X maybe + + + align:start position:0% +how to express u in terms of X maybe +we'd like to know how to express X in + + align:start position:0% +we'd like to know how to express X in + + + align:start position:0% +we'd like to know how to express X in +terms of U well we can do that because + + align:start position:0% +terms of U well we can do that because + + + align:start position:0% +terms of U well we can do that because +we've learned how to solve linear + + align:start position:0% +we've learned how to solve linear + + + align:start position:0% +we've learned how to solve linear +systems like this okay so in principle + + align:start position:0% +systems like this okay so in principle + + + align:start position:0% +systems like this okay so in principle +we could start working substituting and + + align:start position:0% +we could start working substituting and + + + align:start position:0% +we could start working substituting and +so on to find formulas for the X1 X2 X3 + + align:start position:0% +so on to find formulas for the X1 X2 X3 + + + align:start position:0% +so on to find formulas for the X1 X2 X3 +as functions of U1 U2 + + align:start position:0% +as functions of U1 U2 + + + align:start position:0% +as functions of U1 U2 +u3 and the relation will be again a + + align:start position:0% +u3 and the relation will be again a + + + align:start position:0% +u3 and the relation will be again a +linear relation it will again be given + + align:start position:0% +linear relation it will again be given + + + align:start position:0% +linear relation it will again be given +by a matrix well what's that matrix it's + + align:start position:0% +by a matrix well what's that matrix it's + + + align:start position:0% +by a matrix well what's that matrix it's +the inverse transformation so it's the + + align:start position:0% +the inverse transformation so it's the + + + align:start position:0% +the inverse transformation so it's the +inverse of the Matrix + + align:start position:0% + + + + align:start position:0% + +a so we're going to learn how to find + + align:start position:0% +a so we're going to learn how to find + + + align:start position:0% +a so we're going to learn how to find +the inverse of a matrix directly + + align:start position:0% + + + + align:start position:0% + +okay so the + + align:start position:0% + + + + align:start position:0% + +inverse of a by definition it's a + + align:start position:0% +inverse of a by definition it's a + + + align:start position:0% +inverse of a by definition it's a +matrix M with a + + align:start position:0% +matrix M with a + + + align:start position:0% +matrix M with a +property that + + align:start position:0% +property that + + + align:start position:0% +property that +If I multiply a by m then I get identity + + align:start position:0% +If I multiply a by m then I get identity + + + align:start position:0% +If I multiply a by m then I get identity +and If I multiply M by a I also get + + align:start position:0% +and If I multiply M by a I also get + + + align:start position:0% +and If I multiply M by a I also get +identity the two properties are + + align:start position:0% +identity the two properties are + + + align:start position:0% +identity the two properties are +equivalent um so that means you know if + + align:start position:0% +equivalent um so that means you know if + + + align:start position:0% +equivalent um so that means you know if +I apply first the transformation a then + + align:start position:0% +I apply first the transformation a then + + + align:start position:0% +I apply first the transformation a then +the transformation M I actually I undo + + align:start position:0% +the transformation M I actually I undo + + + align:start position:0% +the transformation M I actually I undo +the transformation a and vice versa + + align:start position:0% +the transformation a and vice versa + + + align:start position:0% +the transformation a and vice versa +these two Transformations are the + + align:start position:0% +these two Transformations are the + + + align:start position:0% +these two Transformations are the +opposite of each other well I should say + + align:start position:0% +opposite of each other well I should say + + + align:start position:0% +opposite of each other well I should say +the inverse of each + + align:start position:0% +the inverse of each + + + align:start position:0% +the inverse of each +other okay so + + align:start position:0% +other okay so + + + align:start position:0% +other okay so +for this to make sense we + + align:start position:0% +for this to make sense we + + + align:start position:0% +for this to make sense we +need a must be a square + + align:start position:0% + + + + align:start position:0% + +Matrix okay so it must have size n by n + + align:start position:0% +Matrix okay so it must have size n by n + + + align:start position:0% +Matrix okay so it must have size n by n +can be any size but it must be the same + + align:start position:0% +can be any size but it must be the same + + + align:start position:0% +can be any size but it must be the same +number of rows as + + align:start position:0% +number of rows as + + + align:start position:0% +number of rows as +columns and um it's a general fact that + + align:start position:0% +columns and um it's a general fact that + + + align:start position:0% +columns and um it's a general fact that +I mean you will see more in detail in + + align:start position:0% +I mean you will see more in detail in + + + align:start position:0% +I mean you will see more in detail in +linear + + align:start position:0% +linear + + + align:start position:0% +linear +algebra if you take + + align:start position:0% +algebra if you take + + + align:start position:0% +algebra if you take +it um so let's just admit that + + align:start position:0% + + + + align:start position:0% + +so so the Matrix M we will denote by a + + align:start position:0% +so so the Matrix M we will denote by a + + + align:start position:0% +so so the Matrix M we will denote by a +inverse like this + + align:start position:0% +inverse like this + + + align:start position:0% +inverse like this +okay and then what is it good for well + + align:start position:0% +okay and then what is it good for well + + + align:start position:0% +okay and then what is it good for well +for example the + + align:start position:0% +for example the + + + align:start position:0% +for example the +solution to a linear + + align:start position:0% +solution to a linear + + + align:start position:0% +solution to a linear +system so what's a linear system in our + + align:start position:0% +system so what's a linear system in our + + + align:start position:0% +system so what's a linear system in our +new language it's a matrix times some + + align:start position:0% +new language it's a matrix times some + + + align:start position:0% +new language it's a matrix times some +unknown Vector x equals some known + + align:start position:0% +unknown Vector x equals some known + + + align:start position:0% +unknown Vector x equals some known +Vector B + + align:start position:0% +Vector B + + + align:start position:0% +Vector B +well how do we solve + + align:start position:0% +well how do we solve + + + align:start position:0% +well how do we solve +that we + + align:start position:0% +that we + + + align:start position:0% +that we +just compute xals a inverse B why does + + align:start position:0% +just compute xals a inverse B why does + + + align:start position:0% +just compute xals a inverse B why does +that + + align:start position:0% +that + + + align:start position:0% +that +work how do I get from here to here + + align:start position:0% +work how do I get from here to here + + + align:start position:0% +work how do I get from here to here +let's be + + align:start position:0% +let's be + + + align:start position:0% +let's be +careful + + align:start position:0% + + + + align:start position:0% + +oh okay well I'm going to reuse this + + align:start position:0% +oh okay well I'm going to reuse this + + + align:start position:0% +oh okay well I'm going to reuse this +Matrix but I'm going to erase it + + align:start position:0% +Matrix but I'm going to erase it + + + align:start position:0% +Matrix but I'm going to erase it +nonetheless I'll just rewrite it + + align:start position:0% + + + + align:start position:0% + +minute + + align:start position:0% + + + + align:start position:0% + +so I'm saying if ax equals + + align:start position:0% +so I'm saying if ax equals + + + align:start position:0% +so I'm saying if ax equals +B then + + align:start position:0% +B then + + + align:start position:0% +B then +let's multiply both sides by a inverse a + + align:start position:0% +let's multiply both sides by a inverse a + + + align:start position:0% +let's multiply both sides by a inverse a +inverse * a x is a inverse B and then + + align:start position:0% +inverse * a x is a inverse B and then + + + align:start position:0% +inverse * a x is a inverse B and then +well a inverse * a is identity so I get + + align:start position:0% +well a inverse * a is identity so I get + + + align:start position:0% +well a inverse * a is identity so I get +x equals a inverse B that's how I solved + + align:start position:0% +x equals a inverse B that's how I solved + + + align:start position:0% +x equals a inverse B that's how I solved +my system of + + align:start position:0% +my system of + + + align:start position:0% +my system of +equations so if you have a calculator + + align:start position:0% +equations so if you have a calculator + + + align:start position:0% +equations so if you have a calculator +that can invert matrices then you can + + align:start position:0% +that can invert matrices then you can + + + align:start position:0% +that can invert matrices then you can +solve linear systems very + + align:start position:0% +solve linear systems very + + + align:start position:0% +solve linear systems very +quickly now we should still learn how to + + align:start position:0% +quickly now we should still learn how to + + + align:start position:0% +quickly now we should still learn how to +compute these things yes + + align:start position:0% + + + + align:start position:0% + +how do I know that a inverse will be on + + align:start position:0% +how do I know that a inverse will be on + + + align:start position:0% +how do I know that a inverse will be on +the left of B and not after it well it's + + align:start position:0% +the left of B and not after it well it's + + + align:start position:0% +the left of B and not after it well it's +exactly in this derivation so if you're + + align:start position:0% +exactly in this derivation so if you're + + + align:start position:0% +exactly in this derivation so if you're +ever not sure then just reproduce this + + align:start position:0% +ever not sure then just reproduce this + + + align:start position:0% +ever not sure then just reproduce this +calculation see I mean to get from here + + align:start position:0% +calculation see I mean to get from here + + + align:start position:0% +calculation see I mean to get from here +to here what I did is I multiplied + + align:start position:0% +to here what I did is I multiplied + + + align:start position:0% +to here what I did is I multiplied +things on the left by a inverse and then + + align:start position:0% +things on the left by a inverse and then + + + align:start position:0% +things on the left by a inverse and then +this gu simplify if I had put a inverse + + align:start position:0% +this gu simplify if I had put a inverse + + + align:start position:0% +this gu simplify if I had put a inverse +on the right I would have a x a inverse + + align:start position:0% +on the right I would have a x a inverse + + + align:start position:0% +on the right I would have a x a inverse +which might not make sense and even if + + align:start position:0% +which might not make sense and even if + + + align:start position:0% +which might not make sense and even if +it makes sense it doesn't + + align:start position:0% +it makes sense it doesn't + + + align:start position:0% +it makes sense it doesn't +simplify so I me the basic rle is you + + align:start position:0% +simplify so I me the basic rle is you + + + align:start position:0% +simplify so I me the basic rle is you +know you have to multiply by inverse on + + align:start position:0% +know you have to multiply by inverse on + + + align:start position:0% +know you have to multiply by inverse on +the left so that it cancels with this a + + align:start position:0% +the left so that it cancels with this a + + + align:start position:0% +the left so that it cancels with this a +that's on the + + align:start position:0% + + + + align:start position:0% + +left that's correct so and you know in + + align:start position:0% +left that's correct so and you know in + + + align:start position:0% +left that's correct so and you know in +our usual way of dealing with matrices + + align:start position:0% +our usual way of dealing with matrices + + + align:start position:0% +our usual way of dealing with matrices +where the vectors are column vectors I + + align:start position:0% +where the vectors are column vectors I + + + align:start position:0% +where the vectors are column vectors I +mean it's just something to remember + + align:start position:0% +mean it's just something to remember + + + align:start position:0% +mean it's just something to remember +that if you have a square Matrix times a + + align:start position:0% +that if you have a square Matrix times a + + + align:start position:0% +that if you have a square Matrix times a +column Vector I mean the product that + + align:start position:0% +column Vector I mean the product that + + + align:start position:0% +column Vector I mean the product that +makes sense is with the Matrix on the + + align:start position:0% +makes sense is with the Matrix on the + + + align:start position:0% +makes sense is with the Matrix on the +left the vect on the right the other one + + align:start position:0% +left the vect on the right the other one + + + align:start position:0% +left the vect on the right the other one +just doesn't work it's not sized you + + align:start position:0% +just doesn't work it's not sized you + + + align:start position:0% +just doesn't work it's not sized you +cannot take x * a if a and + + align:start position:0% +cannot take x * a if a and + + + align:start position:0% +cannot take x * a if a and +X you know if a is a square Matrix and X + + align:start position:0% +X you know if a is a square Matrix and X + + + align:start position:0% +X you know if a is a square Matrix and X +is a column Vector this product makes + + align:start position:0% +is a column Vector this product makes + + + align:start position:0% +is a column Vector this product makes +sense the other one doesn't make sense + + align:start position:0% +sense the other one doesn't make sense + + + align:start position:0% +sense the other one doesn't make sense +it's not the right + + align:start position:0% + + + + align:start position:0% + +size + + align:start position:0% +size + + + align:start position:0% +size +okay so what we need to do is to learn + + align:start position:0% +okay so what we need to do is to learn + + + align:start position:0% +okay so what we need to do is to learn +how to invert a matrix and it's useful + + align:start position:0% +how to invert a matrix and it's useful + + + align:start position:0% +how to invert a matrix and it's useful +to know first for your general knowledge + + align:start position:0% +to know first for your general knowledge + + + align:start position:0% +to know first for your general knowledge +and second because uh actually + + align:start position:0% +and second because uh actually + + + align:start position:0% +and second because uh actually +it's uh it's actually useful later for + + align:start position:0% +it's uh it's actually useful later for + + + align:start position:0% +it's uh it's actually useful later for +things we'll see in this class so in + + align:start position:0% +things we'll see in this class so in + + + align:start position:0% +things we'll see in this class so in +particular on the exam you will need to + + align:start position:0% +particular on the exam you will need to + + + align:start position:0% +particular on the exam you will need to +know how to invert a matrix by + + align:start position:0% +know how to invert a matrix by + + + align:start position:0% +know how to invert a matrix by +hand so I should say this formula is + + align:start position:0% +hand so I should say this formula is + + + align:start position:0% +hand so I should say this formula is +actually good for small matrices you + + align:start position:0% +actually good for small matrices you + + + align:start position:0% +actually good for small matrices you +know 3x3 + + align:start position:0% +know 3x3 + + + align:start position:0% +know 3x3 +4x4 it's not good at all if you have a + + align:start position:0% +4x4 it's not good at all if you have a + + + align:start position:0% +4x4 it's not good at all if you have a +matrix of size a thousand by a thousand + + align:start position:0% +matrix of size a thousand by a thousand + + + align:start position:0% +matrix of size a thousand by a thousand +so in computer software actually for + + align:start position:0% +so in computer software actually for + + + align:start position:0% +so in computer software actually for +small matrices they do this for larger + + align:start position:0% +small matrices they do this for larger + + + align:start position:0% +small matrices they do this for larger +matrices they use other + + align:start position:0% + + + + align:start position:0% + +algorithms but let's just see how we do + + align:start position:0% +algorithms but let's just see how we do + + + align:start position:0% +algorithms but let's just see how we do +it so I'm going to do it okay so first + + align:start position:0% +it so I'm going to do it okay so first + + + align:start position:0% +it so I'm going to do it okay so first +of all I will give you the final + + align:start position:0% +of all I will give you the final + + + align:start position:0% +of all I will give you the final +answer and of course for that I will + + align:start position:0% +answer and of course for that I will + + + align:start position:0% +answer and of course for that I will +need to explain what the answer + + align:start position:0% +need to explain what the answer + + + align:start position:0% +need to explain what the answer +means so we'll have to compute something + + align:start position:0% +means so we'll have to compute something + + + align:start position:0% +means so we'll have to compute something +called The adjoint Matrix and I will + + align:start position:0% +called The adjoint Matrix and I will + + + align:start position:0% +called The adjoint Matrix and I will +tell you how to do that and then we'll + + align:start position:0% +tell you how to do that and then we'll + + + align:start position:0% +tell you how to do that and then we'll +divide by the determinant of a + + align:start position:0% + + + + align:start position:0% + +so how do we get to the adjoint Matrix + + align:start position:0% +so how do we get to the adjoint Matrix + + + align:start position:0% +so how do we get to the adjoint Matrix +so let's go through the + + align:start position:0% +so let's go through the + + + align:start position:0% +so let's go through the +steps on a 3X3 + + align:start position:0% + + + + align:start position:0% + +example the steps are the same no matter + + align:start position:0% +example the steps are the same no matter + + + align:start position:0% +example the steps are the same no matter +what the size is but let's do 3 by + + align:start position:0% +what the size is but let's do 3 by + + + align:start position:0% +what the size is but let's do 3 by +three so let's say that I'm giving you + + align:start position:0% +three so let's say that I'm giving you + + + align:start position:0% +three so let's say that I'm giving you +the Matrix a well let's say it's the + + align:start position:0% +the Matrix a well let's say it's the + + + align:start position:0% +the Matrix a well let's say it's the +same as earlier the one I erased so that + + align:start position:0% +same as earlier the one I erased so that + + + align:start position:0% +same as earlier the one I erased so that +was the one relating + + align:start position:0% +was the one relating + + + align:start position:0% +was the one relating +our xes and our + + align:start position:0% + + + + align:start position:0% + +use so the first thing I want to + + align:start position:0% +use so the first thing I want to + + + align:start position:0% +use so the first thing I want to +do is find What's called the + + align:start position:0% + + + + align:start position:0% + +minors so what's a + + align:start position:0% +minors so what's a + + + align:start position:0% +minors so what's a +minor well it's a slightly smaller + + align:start position:0% +minor well it's a slightly smaller + + + align:start position:0% +minor well it's a slightly smaller +determinant we've already seen them + + align:start position:0% +determinant we've already seen them + + + align:start position:0% +determinant we've already seen them +without calling them that way + + align:start position:0% +without calling them that way + + + align:start position:0% +without calling them that way +so for example so the Matrix of miners + + align:start position:0% +so for example so the Matrix of miners + + + align:start position:0% +so for example so the Matrix of miners +will have again the same size okay let's + + align:start position:0% +will have again the same size okay let's + + + align:start position:0% +will have again the same size okay let's +say we want this entry then we just + + align:start position:0% +say we want this entry then we just + + + align:start position:0% +say we want this entry then we just +delete this row and this column sorry + + align:start position:0% +delete this row and this column sorry + + + align:start position:0% +delete this row and this column sorry +this row and this column and we're left + + align:start position:0% +this row and this column and we're left + + + align:start position:0% +this row and this column and we're left +with a 2X two determinant okay so here + + align:start position:0% +with a 2X two determinant okay so here + + + align:start position:0% +with a 2X two determinant okay so here +we'll put the determinant 4 51 2 which + + align:start position:0% +we'll put the determinant 4 51 2 which + + + align:start position:0% +we'll put the determinant 4 51 2 which +is 4 * 2 8 - 5 + + align:start position:0% +is 4 * 2 8 - 5 + + + align:start position:0% +is 4 * 2 8 - 5 +3 let's do the next one so for this + + align:start position:0% +3 let's do the next one so for this + + + align:start position:0% +3 let's do the next one so for this +entry I delete this row and this column + + align:start position:0% +entry I delete this row and this column + + + align:start position:0% +entry I delete this row and this column +I'm left with 2 5 1 2 determinant will + + align:start position:0% +I'm left with 2 5 1 2 determinant will + + + align:start position:0% +I'm left with 2 5 1 2 determinant will +be 2 * 2 - 5 + + align:start position:0% +be 2 * 2 - 5 + + + align:start position:0% +be 2 * 2 - 5 +is1 + + align:start position:0% +is1 + + + align:start position:0% +is1 +then minus two then I get to the second + + align:start position:0% +then minus two then I get to the second + + + align:start position:0% +then minus two then I get to the second +row so I get to this entry well to find + + align:start position:0% +row so I get to this entry well to find + + + align:start position:0% +row so I get to this entry well to find +the minor here I will delete this row + + align:start position:0% +the minor here I will delete this row + + + align:start position:0% +the minor here I will delete this row +and this column and I'm left with 3 3 1 + + align:start position:0% +and this column and I'm left with 3 3 1 + + + align:start position:0% +and this column and I'm left with 3 3 1 +2 3 * 2us 3 is + + align:start position:0% +2 3 * 2us 3 is + + + align:start position:0% +2 3 * 2us 3 is +3 and let me just cheat and give you the + + align:start position:0% +3 and let me just cheat and give you the + + + align:start position:0% +3 and let me just cheat and give you the +others I mean I think I've shown you + + align:start position:0% +others I mean I think I've shown you + + + align:start position:0% +others I mean I think I've shown you +that I can do them + + align:start position:0% +that I can do them + + + align:start position:0% +that I can do them +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so okay so let's just explain the last + + align:start position:0% +so okay so let's just explain the last + + + align:start position:0% +so okay so let's just explain the last +one again the last one this two um so to + + align:start position:0% +one again the last one this two um so to + + + align:start position:0% +one again the last one this two um so to +find the minor here I delete this column + + align:start position:0% +find the minor here I delete this column + + + align:start position:0% +find the minor here I delete this column +and this row and I take this determinant + + align:start position:0% +and this row and I take this determinant + + + align:start position:0% +and this row and I take this determinant +2 * 4 minus 2 * + + align:start position:0% +2 * 4 minus 2 * + + + align:start position:0% +2 * 4 minus 2 * +3 okay so it's the same kind of + + align:start position:0% +3 okay so it's the same kind of + + + align:start position:0% +3 okay so it's the same kind of +manipulation that we've seen when we've + + align:start position:0% +manipulation that we've seen when we've + + + align:start position:0% +manipulation that we've seen when we've +taken determinants and cross + + align:start position:0% + + + + align:start position:0% + +products okay step + + align:start position:0% +products okay step + + + align:start position:0% +products okay step +two we go to another Matrix that's + + align:start position:0% +two we go to another Matrix that's + + + align:start position:0% +two we go to another Matrix that's +called co-actors so the co-actors are + + align:start position:0% +called co-actors so the co-actors are + + + align:start position:0% +called co-actors so the co-actors are +pretty much the same thing as the minus + + align:start position:0% +pretty much the same thing as the minus + + + align:start position:0% +pretty much the same thing as the minus +except the signs are slightly + + align:start position:0% +except the signs are slightly + + + align:start position:0% +except the signs are slightly +different okay so what we do is we flip + + align:start position:0% +different okay so what we do is we flip + + + align:start position:0% +different okay so what we do is we flip +signs according to a + + align:start position:0% + + + + align:start position:0% + +checkerboard diagram + + align:start position:0% +checkerboard diagram + + + align:start position:0% +checkerboard diagram +so you start with a plus in the upper + + align:start position:0% +so you start with a plus in the upper + + + align:start position:0% +so you start with a plus in the upper +left corner and you alternate pluses and + + align:start position:0% +left corner and you alternate pluses and + + + align:start position:0% +left corner and you alternate pluses and +minuses Okay so + + align:start position:0% +minuses Okay so + + + align:start position:0% +minuses Okay so +the rule is if there's a plus somewhere + + align:start position:0% +the rule is if there's a plus somewhere + + + align:start position:0% +the rule is if there's a plus somewhere +then there's a minus next to it and + + align:start position:0% +then there's a minus next to it and + + + align:start position:0% +then there's a minus next to it and +below + + align:start position:0% +below + + + align:start position:0% +below +it and then below a minus or to the + + align:start position:0% +it and then below a minus or to the + + + align:start position:0% +it and then below a minus or to the +right of a minus there's a plus okay so + + align:start position:0% +right of a minus there's a plus okay so + + + align:start position:0% +right of a minus there's a plus okay so +that's what it looks in size + + align:start position:0% +that's what it looks in size + + + align:start position:0% +that's what it looks in size +3x3 um so what do I mean by that so I + + align:start position:0% +3x3 um so what do I mean by that so I + + + align:start position:0% +3x3 um so what do I mean by that so I +don't mean you know make this positive + + align:start position:0% +don't mean you know make this positive + + + align:start position:0% +don't mean you know make this positive +make this negative and so on that's not + + align:start position:0% +make this negative and so on that's not + + + align:start position:0% +make this negative and so on that's not +what I mean what I mean is if there's a + + align:start position:0% +what I mean what I mean is if there's a + + + align:start position:0% +what I mean what I mean is if there's a +plus that means leave it alone okay we + + align:start position:0% +plus that means leave it alone okay we + + + align:start position:0% +plus that means leave it alone okay we +don't do anything to it if there's a + + align:start position:0% +don't do anything to it if there's a + + + align:start position:0% +don't do anything to it if there's a +minus that means we flip the + + align:start position:0% + + + + align:start position:0% + +sign okay so here we get well three + + align:start position:0% +sign okay so here we get well three + + + align:start position:0% +sign okay so here we get well three +then 1 minus + + align:start position:0% +then 1 minus + + + align:start position:0% +then 1 minus +2us 3 1 + + + align:start position:0% +2us 3 1 + + + + align:start position:0% +2us 3 1 + +1be I'll put pluses just to emphasize 3 + + align:start position:0% +1be I'll put pluses just to emphasize 3 + + + align:start position:0% +1be I'll put pluses just to emphasize 3 +- 4 and + + align:start position:0% +- 4 and + + + align:start position:0% +- 4 and +two okay let's St is pretty easy I mean + + align:start position:0% +two okay let's St is pretty easy I mean + + + align:start position:0% +two okay let's St is pretty easy I mean +the only hard step in terms of + + align:start position:0% +the only hard step in terms of + + + align:start position:0% +the only hard step in terms of +calculations is this one because you + + align:start position:0% +calculations is this one because you + + + align:start position:0% +calculations is this one because you +have to compute all of these 2x two + + align:start position:0% + + + + align:start position:0% + +determinants by the way I mean this + + align:start position:0% +determinants by the way I mean this + + + align:start position:0% +determinants by the way I mean this +minus sign here see it's actually very + + align:start position:0% +minus sign here see it's actually very + + + align:start position:0% +minus sign here see it's actually very +related to the way in which when we do a + + align:start position:0% +related to the way in which when we do a + + + align:start position:0% +related to the way in which when we do a +cross product we have a minus sign for + + align:start position:0% +cross product we have a minus sign for + + + align:start position:0% +cross product we have a minus sign for +the second + + align:start position:0% +the second + + + align:start position:0% +the second +entry okay we + + align:start position:0% +entry okay we + + + align:start position:0% +entry okay we +are almost done third step is to + + align:start position:0% +are almost done third step is to + + + align:start position:0% +are almost done third step is to +transpose + + align:start position:0% + + + + align:start position:0% + +so what does it mean to transpose it + + align:start position:0% +so what does it mean to transpose it + + + align:start position:0% +so what does it mean to transpose it +means you read the rows of your Matrix + + align:start position:0% +means you read the rows of your Matrix + + + align:start position:0% +means you read the rows of your Matrix +and you write that as columns or vice + + align:start position:0% +and you write that as columns or vice + + + align:start position:0% +and you write that as columns or vice +versa okay so let me just say we + + align:start position:0% +versa okay so let me just say we + + + align:start position:0% +versa okay so let me just say we +switch rows and + + align:start position:0% + + + + align:start position:0% + +columns so what do we get well let's + + align:start position:0% +columns so what do we get well let's + + + align:start position:0% +columns so what do we get well let's +just read it horizontally and write it + + align:start position:0% +just read it horizontally and write it + + + align:start position:0% +just read it horizontally and write it +vertically we read 3 1 - 2 3 1 - 2 then + + align:start position:0% +vertically we read 3 1 - 2 3 1 - 2 then + + + align:start position:0% +vertically we read 3 1 - 2 3 1 - 2 then +we read - 3 1 1 + + align:start position:0% +we read - 3 1 1 + + + align:start position:0% +we read - 3 1 1 +- 3 1 1 then 3 - 4 2 3 - 4 + + align:start position:0% +- 3 1 1 then 3 - 4 2 3 - 4 + + + align:start position:0% +- 3 1 1 then 3 - 4 2 3 - 4 +2 okay that's pretty + + align:start position:0% +2 okay that's pretty + + + align:start position:0% +2 okay that's pretty +easy and we're almost done the last step + + align:start position:0% +easy and we're almost done the last step + + + align:start position:0% +easy and we're almost done the last step +so what we get here is this is the + + align:start position:0% +so what we get here is this is the + + + align:start position:0% +so what we get here is this is the +adjoint + + align:start position:0% +adjoint + + + align:start position:0% +adjoint +Matrix so the fourth and last step is to + + align:start position:0% +Matrix so the fourth and last step is to + + + align:start position:0% +Matrix so the fourth and last step is to +divide by the determinant of a + + align:start position:0% + + + + align:start position:0% + +okay so here we have to compute the + + align:start position:0% +okay so here we have to compute the + + + align:start position:0% +okay so here we have to compute the +determinant 2 3 three so we should say + + align:start position:0% +determinant 2 3 three so we should say + + + align:start position:0% +determinant 2 3 three so we should say +determinant of a okay not the + + align:start position:0% +determinant of a okay not the + + + align:start position:0% +determinant of a okay not the +determinant of this + + align:start position:0% +determinant of this + + + align:start position:0% +determinant of this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +so 2 3 3 2 4 5 112 well I let you check + + align:start position:0% +so 2 3 3 2 4 5 112 well I let you check + + + align:start position:0% +so 2 3 3 2 4 5 112 well I let you check +my computation I found that it's equal + + align:start position:0% +my computation I found that it's equal + + + align:start position:0% +my computation I found that it's equal +to + + align:start position:0% +to + + + align:start position:0% +to +three okay so the final answer is that a + + align:start position:0% +three okay so the final answer is that a + + + align:start position:0% +three okay so the final answer is that a +inverse is 1/3 of The Matrix we got + + align:start position:0% +inverse is 1/3 of The Matrix we got + + + align:start position:0% +inverse is 1/3 of The Matrix we got +there 3 - 3 3 1 1 - 4 - 2 1 + + align:start position:0% + + + + align:start position:0% + +two okay and now so that tells us + + align:start position:0% +two okay and now so that tells us + + + align:start position:0% +two okay and now so that tells us +remember a told us how to find the use + + align:start position:0% +remember a told us how to find the use + + + align:start position:0% +remember a told us how to find the use +in terms of the X's this one tells us + + align:start position:0% +in terms of the X's this one tells us + + + align:start position:0% +in terms of the X's this one tells us +now how to find the x's in terms of the + + align:start position:0% +now how to find the x's in terms of the + + + align:start position:0% +now how to find the x's in terms of the +use if you multiply U1 U2 u3 by this you + + align:start position:0% +use if you multiply U1 U2 u3 by this you + + + align:start position:0% +use if you multiply U1 U2 u3 by this you +get back X1 X2 + + align:start position:0% +get back X1 X2 + + + align:start position:0% +get back X1 X2 +X3 it also tells you how to solve the + + align:start position:0% +X3 it also tells you how to solve the + + + align:start position:0% +X3 it also tells you how to solve the +linear system a * xal + + align:start position:0% + + + + align:start position:0% + +something okay that's the end for today \ No newline at end of file diff --git a/c15RtHXBVuQ.txt b/c15RtHXBVuQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..8f3fd121dc4159e13cb5d5a6f8f5752a0da0668d --- /dev/null +++ b/c15RtHXBVuQ.txt @@ -0,0 +1,1027 @@ +align:start position:0% + +let's consider examples of our principle + + align:start position:0% +let's consider examples of our principle + + + align:start position:0% +let's consider examples of our principle +that the external torque about a point + + align:start position:0% +that the external torque about a point + + + align:start position:0% +that the external torque about a point +as causes the angular momentum of a + + align:start position:0% +as causes the angular momentum of a + + + align:start position:0% +as causes the angular momentum of a +system to change about s we've examined + + align:start position:0% +system to change about s we've examined + + + align:start position:0% +system to change about s we've examined +central force problems in which we chose + + align:start position:0% +central force problems in which we chose + + + align:start position:0% +central force problems in which we chose +the point s to be the central point in + + align:start position:0% +the point s to be the central point in + + + align:start position:0% +the point s to be the central point in +which there was no torque now as + + align:start position:0% +which there was no torque now as + + + align:start position:0% +which there was no torque now as +examples let's look at a case where we + + align:start position:0% +examples let's look at a case where we + + + align:start position:0% +examples let's look at a case where we +have a pivoted object so I could take an + + align:start position:0% +have a pivoted object so I could take an + + + align:start position:0% +have a pivoted object so I could take an +example of a object let's see this will + + align:start position:0% +example of a object let's see this will + + + align:start position:0% +example of a object let's see this will +be an overhead view of a ring of radius + + align:start position:0% +be an overhead view of a ring of radius + + + align:start position:0% +be an overhead view of a ring of radius +R and I'm going to have a mass coming in + + align:start position:0% +R and I'm going to have a mass coming in + + + align:start position:0% +R and I'm going to have a mass coming in +I'll call this ring mass M 1 this object + + align:start position:0% +I'll call this ring mass M 1 this object + + + align:start position:0% +I'll call this ring mass M 1 this object +and to this object is coming in with an + + align:start position:0% +and to this object is coming in with an + + + align:start position:0% +and to this object is coming in with an +initial velocity and this is my pivot + + align:start position:0% +initial velocity and this is my pivot + + + align:start position:0% +initial velocity and this is my pivot +point now when the object m2 is hitting + + align:start position:0% +point now when the object m2 is hitting + + + align:start position:0% +point now when the object m2 is hitting +the ring we have a force f2 on one this + + align:start position:0% +the ring we have a force f2 on one this + + + align:start position:0% +the ring we have a force f2 on one this +is the collision here's our pivot point + + align:start position:0% +is the collision here's our pivot point + + + align:start position:0% +is the collision here's our pivot point +and when this hits the ring we'll have + + align:start position:0% +and when this hits the ring we'll have + + + align:start position:0% +and when this hits the ring we'll have +some type of pivot force I'm just going + + align:start position:0% +some type of pivot force I'm just going + + + align:start position:0% +some type of pivot force I'm just going +to denote the pivot force we're not + + align:start position:0% +to denote the pivot force we're not + + + align:start position:0% +to denote the pivot force we're not +quite sure what it will point out but + + align:start position:0% +quite sure what it will point out but + + + align:start position:0% +quite sure what it will point out but +I'll just say F pivot for the moment is + + align:start position:0% +I'll just say F pivot for the moment is + + + align:start position:0% +I'll just say F pivot for the moment is +holding this point in place at the same + + align:start position:0% +holding this point in place at the same + + + align:start position:0% +holding this point in place at the same +time the object will have a force f1 - + + align:start position:0% +time the object will have a force f1 - + + + align:start position:0% +time the object will have a force f1 - +acting on the object here's our pivot + + align:start position:0% +acting on the object here's our pivot + + + align:start position:0% +acting on the object here's our pivot +point P and now what point should we if + + align:start position:0% +point P and now what point should we if + + + align:start position:0% +point P and now what point should we if +we should we choose to see if there's no + + align:start position:0% +we should we choose to see if there's no + + + align:start position:0% +we should we choose to see if there's no +torque about suppose we choose + + align:start position:0% +torque about suppose we choose + + + align:start position:0% +torque about suppose we choose +the pivot point well Pete well clearly + + align:start position:0% +the pivot point well Pete well clearly + + + align:start position:0% +the pivot point well Pete well clearly +the pivot force has no torque about the + + align:start position:0% +the pivot force has no torque about the + + + align:start position:0% +the pivot force has no torque about the +pivot because the vector from the pivot + + align:start position:0% +pivot because the vector from the pivot + + + align:start position:0% +pivot because the vector from the pivot +point to where the pivot force is acting + + align:start position:0% +point to where the pivot force is acting + + + align:start position:0% +point to where the pivot force is acting +is zero + + align:start position:0% +is zero + + + align:start position:0% +is zero +remember pivot forces have no torque + + align:start position:0% +remember pivot forces have no torque + + + align:start position:0% +remember pivot forces have no torque +about the pivot point however this + + align:start position:0% +about the pivot point however this + + + align:start position:0% +about the pivot point however this +collision force will produce a torque + + align:start position:0% +collision force will produce a torque + + + align:start position:0% +collision force will produce a torque +about the pivot and that's the angular + + align:start position:0% +about the pivot and that's the angular + + + align:start position:0% +about the pivot and that's the angular +momentum of the Ring is not constant + + align:start position:0% +momentum of the Ring is not constant + + + align:start position:0% +momentum of the Ring is not constant +because the ring will start to rotate + + align:start position:0% +because the ring will start to rotate + + + align:start position:0% +because the ring will start to rotate +similarly this object is reversing to + + align:start position:0% +similarly this object is reversing to + + + align:start position:0% +similarly this object is reversing to +will reverse directions or will do + + align:start position:0% +will reverse directions or will do + + + align:start position:0% +will reverse directions or will do +something due to the collision and again + + align:start position:0% +something due to the collision and again + + + align:start position:0% +something due to the collision and again +this force will produce a torque that's + + align:start position:0% +this force will produce a torque that's + + + align:start position:0% +this force will produce a torque that's +equal and opposite to the torque on the + + align:start position:0% +equal and opposite to the torque on the + + + align:start position:0% +equal and opposite to the torque on the +ring this is the torque on the particle + + align:start position:0% +ring this is the torque on the particle + + + align:start position:0% +ring this is the torque on the particle +but if we make our system equal to the + + align:start position:0% +but if we make our system equal to the + + + align:start position:0% +but if we make our system equal to the +particle and the ring so we'll call this + + align:start position:0% +particle and the ring so we'll call this + + + align:start position:0% +particle and the ring so we'll call this +our system is now both the particle and + + align:start position:0% +our system is now both the particle and + + + align:start position:0% +our system is now both the particle and +the ring then these torques are internal + + align:start position:0% +the ring then these torques are internal + + + align:start position:0% +the ring then these torques are internal +and because they're equal and opposite + + align:start position:0% +and because they're equal and opposite + + + align:start position:0% +and because they're equal and opposite +forces the RS vector is exactly the same + + align:start position:0% +forces the RS vector is exactly the same + + + align:start position:0% +forces the RS vector is exactly the same +RS vector the internal torques cancel in + + align:start position:0% +RS vector the internal torques cancel in + + + align:start position:0% +RS vector the internal torques cancel in +pairs the pivot force produces no torque + + align:start position:0% +pairs the pivot force produces no torque + + + align:start position:0% +pairs the pivot force produces no torque +so the torque on the system about the + + align:start position:0% +so the torque on the system about the + + + align:start position:0% +so the torque on the system about the +pivot is zero and that tells us that the + + align:start position:0% +pivot is zero and that tells us that the + + + align:start position:0% +pivot is zero and that tells us that the +angular momentum of the system about + + align:start position:0% +angular momentum of the system about + + + align:start position:0% +angular momentum of the system about +that pivot point initially will be equal + + align:start position:0% +that pivot point initially will be equal + + + align:start position:0% +that pivot point initially will be equal +to the angular momentum about that pivot + + align:start position:0% +to the angular momentum about that pivot + + + align:start position:0% +to the angular momentum about that pivot +point finally if we take two initial and + + align:start position:0% +point finally if we take two initial and + + + align:start position:0% +point finally if we take two initial and +final States in particular suppose our + + align:start position:0% +final States in particular suppose our + + + align:start position:0% +final States in particular suppose our +initial state is here's the pivot our + + align:start position:0% +initial state is here's the pivot our + + + align:start position:0% +initial state is here's the pivot our +object is coming in that was M to be I + + align:start position:0% + + + + align:start position:0% + +the moment arm is our and our vector + + align:start position:0% +the moment arm is our and our vector + + + align:start position:0% +the moment arm is our and our vector +from here to the object RS initial has a + + align:start position:0% +from here to the object RS initial has a + + + align:start position:0% +from here to the object RS initial has a +moment component that way if we put + + align:start position:0% +moment component that way if we put + + + align:start position:0% +moment component that way if we put +these vectors tail the tail and figure + + align:start position:0% +these vectors tail the tail and figure + + + align:start position:0% +these vectors tail the tail and figure +out that the angular momentum is + + align:start position:0% +out that the angular momentum is + + + align:start position:0% +out that the angular momentum is +pointing in this direction L initial I + + align:start position:0% +pointing in this direction L initial I + + + align:start position:0% +pointing in this direction L initial I +and the moment arm is R then the initial + + align:start position:0% +and the moment arm is R then the initial + + + align:start position:0% +and the moment arm is R then the initial +angular momentum about this pivot point + + align:start position:0% +angular momentum about this pivot point + + + align:start position:0% +angular momentum about this pivot point +is just due to this moving object so + + align:start position:0% +is just due to this moving object so + + + align:start position:0% +is just due to this moving object so +that's M to the I and the moment arm is + + align:start position:0% +that's M to the I and the moment arm is + + + align:start position:0% +that's M to the I and the moment arm is +R and we'll denote its direction that + + align:start position:0% +R and we'll denote its direction that + + + align:start position:0% +R and we'll denote its direction that +way now the final angular Mountain let's + + align:start position:0% +way now the final angular Mountain let's + + + align:start position:0% +way now the final angular Mountain let's +imagine that it sticks so we have M 2 + + align:start position:0% +imagine that it sticks so we have M 2 + + + align:start position:0% +imagine that it sticks so we have M 2 +pivot and now our ring is going to be + + align:start position:0% +pivot and now our ring is going to be + + + align:start position:0% +pivot and now our ring is going to be +rotating with some Omega final because + + align:start position:0% +rotating with some Omega final because + + + align:start position:0% +rotating with some Omega final because +this object hits it and notice that this + + align:start position:0% +this object hits it and notice that this + + + align:start position:0% +this object hits it and notice that this +object is a distance root 2 R from the + + align:start position:0% +object is a distance root 2 R from the + + + align:start position:0% +object is a distance root 2 R from the +pivot point so the final angular + + align:start position:0% +pivot point so the final angular + + + align:start position:0% +pivot point so the final angular +momentum can be two different pieces you + + align:start position:0% +momentum can be two different pieces you + + + align:start position:0% +momentum can be two different pieces you +can think of this as a system where we + + align:start position:0% +can think of this as a system where we + + + align:start position:0% +can think of this as a system where we +have I of the system about P times Omega + + align:start position:0% +have I of the system about P times Omega + + + align:start position:0% +have I of the system about P times Omega +final because now it's just a rigid body + + align:start position:0% +final because now it's just a rigid body + + + align:start position:0% +final because now it's just a rigid body +and the angular momentum of the system + + align:start position:0% +and the angular momentum of the system + + + align:start position:0% +and the angular momentum of the system +is consisting of two pieces its the + + align:start position:0% +is consisting of two pieces its the + + + align:start position:0% +is consisting of two pieces its the +angular momentum of the ring about the + + align:start position:0% +angular momentum of the ring about the + + + align:start position:0% +angular momentum of the ring about the +pivot plus the angular momentum of the + + align:start position:0% +pivot plus the angular momentum of the + + + align:start position:0% +pivot plus the angular momentum of the +particle + + align:start position:0% + + + + align:start position:0% + +about the pivot times Omega final now + + align:start position:0% +about the pivot times Omega final now + + + align:start position:0% +about the pivot times Omega final now +this is a center of mass this is the + + align:start position:0% +this is a center of mass this is the + + + align:start position:0% +this is a center of mass this is the +pivot point P the angular momentum of + + align:start position:0% +pivot point P the angular momentum of + + + align:start position:0% +pivot point P the angular momentum of +the Ring is the angular momentum about + + align:start position:0% +the Ring is the angular momentum about + + + align:start position:0% +the Ring is the angular momentum about +the center we'll use the parallel axis + + align:start position:0% +the center we'll use the parallel axis + + + align:start position:0% +the center we'll use the parallel axis +theorem angular momentum about the + + align:start position:0% +theorem angular momentum about the + + + align:start position:0% +theorem angular momentum about the +center of mass plus the distance from + + align:start position:0% +center of mass plus the distance from + + + align:start position:0% +center of mass plus the distance from +the center of mass to the parallel axis + + align:start position:0% +the center of mass to the parallel axis + + + align:start position:0% +the center of mass to the parallel axis +which is a distance R so the first piece + + align:start position:0% +which is a distance R so the first piece + + + align:start position:0% +which is a distance R so the first piece +is ICM ring plus M R squared and the + + align:start position:0% +is ICM ring plus M R squared and the + + + align:start position:0% +is ICM ring plus M R squared and the +angular mentioned about the particle + + align:start position:0% +angular mentioned about the particle + + + align:start position:0% +angular mentioned about the particle +this is going in a circle of radius R 2 + + align:start position:0% +this is going in a circle of radius R 2 + + + align:start position:0% +this is going in a circle of radius R 2 +root 2 R so when we square that by the + + align:start position:0% +root 2 R so when we square that by the + + + align:start position:0% +root 2 R so when we square that by the +way this was mass of the ring was one + + align:start position:0% +way this was mass of the ring was one + + + align:start position:0% +way this was mass of the ring was one +mass of the particle was m2 times R + + align:start position:0% +mass of the particle was m2 times R + + + align:start position:0% +mass of the particle was m2 times R +squared which is this distance squared + + align:start position:0% +squared which is this distance squared + + + align:start position:0% +squared which is this distance squared +which is 2 R squared times will make a + + align:start position:0% +which is 2 R squared times will make a + + + align:start position:0% +which is 2 R squared times will make a +final the moment of inertia of the ring + + align:start position:0% +final the moment of inertia of the ring + + + align:start position:0% +final the moment of inertia of the ring +is M 1 R squared about the center of + + align:start position:0% +is M 1 R squared about the center of + + + align:start position:0% +is M 1 R squared about the center of +mass we have a factor 2 we have another + + align:start position:0% +mass we have a factor 2 we have another + + + align:start position:0% +mass we have a factor 2 we have another +factor of 2 and so we get M 1 plus M 2 + + align:start position:0% +factor of 2 and so we get M 1 plus M 2 + + + align:start position:0% +factor of 2 and so we get M 1 plus M 2 +times a factor 2 R squared Omega final + + align:start position:0% +times a factor 2 R squared Omega final + + + align:start position:0% +times a factor 2 R squared Omega final +which we can call Omega F pointing out + + align:start position:0% +which we can call Omega F pointing out + + + align:start position:0% +which we can call Omega F pointing out +of the board and so now we have a + + align:start position:0% +of the board and so now we have a + + + align:start position:0% +of the board and so now we have a +angular momentum condition which is that + + align:start position:0% +angular momentum condition which is that + + + align:start position:0% +angular momentum condition which is that +M 2 VI R equals to M 1 plus M 2 R + + align:start position:0% +M 2 VI R equals to M 1 plus M 2 R + + + align:start position:0% +M 2 VI R equals to M 1 plus M 2 R +squared will make a final and that is a + + align:start position:0% +squared will make a final and that is a + + + align:start position:0% +squared will make a final and that is a +statement that the initial angular + + align:start position:0% +statement that the initial angular + + + align:start position:0% +statement that the initial angular +momentum of our system the ring is at + + align:start position:0% +momentum of our system the ring is at + + + align:start position:0% +momentum of our system the ring is at +rest here is equal to the final angular + + align:start position:0% +rest here is equal to the final angular + + + align:start position:0% +rest here is equal to the final angular +momentum of the system where M 2 is + + align:start position:0% +momentum of the system where M 2 is + + + align:start position:0% +momentum of the system where M 2 is +stuck to the ring and they're all + + align:start position:0% +stuck to the ring and they're all + + + align:start position:0% +stuck to the ring and they're all +rotating about this pivot point with + + align:start position:0% +rotating about this pivot point with + + + align:start position:0% +rotating about this pivot point with +omega final that's the angular momentum + + align:start position:0% +omega final that's the angular momentum + + + align:start position:0% +omega final that's the angular momentum +of the system about P will make a final + + align:start position:0% +of the system about P will make a final + + + align:start position:0% +of the system about P will make a final +this is the initial angular momentum and + + align:start position:0% +this is the initial angular momentum and + + + align:start position:0% +this is the initial angular momentum and +so I can conclude that Omega final is M + + align:start position:0% +so I can conclude that Omega final is M + + + align:start position:0% +so I can conclude that Omega final is M +2 VI over 2 m 1 plus M 2 times R + + align:start position:0% +2 VI over 2 m 1 plus M 2 times R + + + align:start position:0% +2 VI over 2 m 1 plus M 2 times R +you \ No newline at end of file diff --git a/cbSkFpO2jgQ.txt b/cbSkFpO2jgQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..40c4aa026ba16bcd48028226a01172e95039e6d1 --- /dev/null +++ b/cbSkFpO2jgQ.txt @@ -0,0 +1,2611 @@ +align:start position:0% + +hi welcome back to + + align:start position:0% +hi welcome back to + + + align:start position:0% +hi welcome back to +tation in lecture you've been learning + + align:start position:0% +tation in lecture you've been learning + + + align:start position:0% +tation in lecture you've been learning +about trip + + align:start position:0% +about trip + + + align:start position:0% +about trip +I have a nice average value problem for + + align:start position:0% +I have a nice average value problem for + + + align:start position:0% +I have a nice average value problem for +you using triple integration here so + + align:start position:0% +you using triple integration here so + + + align:start position:0% +you using triple integration here so +what I'd like you to do is to consider + + align:start position:0% +what I'd like you to do is to consider + + + align:start position:0% +what I'd like you to do is to consider +the tetrahedron that has vertices at the + + align:start position:0% +the tetrahedron that has vertices at the + + + align:start position:0% +the tetrahedron that has vertices at the +origin and at the points 1 0 0 0 1 0 and + + align:start position:0% +origin and at the points 1 0 0 0 1 0 and + + + align:start position:0% +origin and at the points 1 0 0 0 1 0 and +0 0 1 so that's one point on each of the + + align:start position:0% +0 0 1 so that's one point on each of the + + + align:start position:0% +0 0 1 so that's one point on each of the +positive axes at distance 1 from the + + align:start position:0% +positive axes at distance 1 from the + + + align:start position:0% +positive axes at distance 1 from the +origin so it's taking the liberty of + + align:start position:0% +origin so it's taking the liberty of + + + align:start position:0% +origin so it's taking the liberty of +drawing it here for you so consider that + + align:start position:0% +drawing it here for you so consider that + + + align:start position:0% +drawing it here for you so consider that +tetrahedron the solid tetrahedron and + + align:start position:0% +tetrahedron the solid tetrahedron and + + + align:start position:0% +tetrahedron the solid tetrahedron and +what I'd like you to do is find the + + align:start position:0% +what I'd like you to do is find the + + + align:start position:0% +what I'd like you to do is find the +average distance of the points in that + + align:start position:0% +average distance of the points in that + + + align:start position:0% +average distance of the points in that +tetrahedron from the XY plane all right + + align:start position:0% +tetrahedron from the XY plane all right + + + align:start position:0% +tetrahedron from the XY plane all right +so I'd like you to compute that the + + align:start position:0% +so I'd like you to compute that the + + + align:start position:0% +so I'd like you to compute that the +average value of the distance as the + + align:start position:0% +average value of the distance as the + + + align:start position:0% +average value of the distance as the +point ranges over the whole tetrahedron + + align:start position:0% +point ranges over the whole tetrahedron + + + align:start position:0% +point ranges over the whole tetrahedron +of of its of its distance from the XY + + align:start position:0% +of of its of its distance from the XY + + + align:start position:0% +of of its of its distance from the XY +plane so why don't you pause the video + + align:start position:0% +plane so why don't you pause the video + + + align:start position:0% +plane so why don't you pause the video +spend some time working that out come + + align:start position:0% +spend some time working that out come + + + align:start position:0% +spend some time working that out come +back and we can work it out together + + align:start position:0% + + + + align:start position:0% + +hopefully you had some luck with this + + align:start position:0% +hopefully you had some luck with this + + + align:start position:0% +hopefully you had some luck with this +problem let's get started so you know + + align:start position:0% +problem let's get started so you know + + + align:start position:0% +problem let's get started so you know +for an average value problem that that + + align:start position:0% +for an average value problem that that + + + align:start position:0% +for an average value problem that that +if you have a function f so the average + + align:start position:0% +if you have a function f so the average + + + align:start position:0% +if you have a function f so the average +value of a function f over a region R is + + align:start position:0% +value of a function f over a region R is + + + align:start position:0% +value of a function f over a region R is +going to be it's 1 over the volume of + + align:start position:0% +going to be it's 1 over the volume of + + + align:start position:0% +going to be it's 1 over the volume of +the region times the triple integral + + align:start position:0% +the region times the triple integral + + + align:start position:0% +the region times the triple integral +over your whole region R of the function + + align:start position:0% +over your whole region R of the function + + + align:start position:0% +over your whole region R of the function +value f of X Y C with respect to volume + + align:start position:0% +value f of X Y C with respect to volume + + + align:start position:0% +value f of X Y C with respect to volume +so you know in any order you want so I + + align:start position:0% +so you know in any order you want so I + + + align:start position:0% +so you know in any order you want so I +guess I'll write DV here and then you + + align:start position:0% +guess I'll write DV here and then you + + + align:start position:0% +guess I'll write DV here and then you +know to evaluate this you set it up as + + align:start position:0% +know to evaluate this you set it up as + + + align:start position:0% +know to evaluate this you set it up as +an iterated integral so in our case the + + align:start position:0% +an iterated integral so in our case the + + + align:start position:0% +an iterated integral so in our case the +function we're trying to find the + + align:start position:0% +function we're trying to find the + + + align:start position:0% +function we're trying to find the +average value of is the distance between + + align:start position:0% +average value of is the distance between + + + align:start position:0% +average value of is the distance between +a point and the XY plane but that's + + align:start position:0% +a point and the XY plane but that's + + + align:start position:0% +a point and the XY plane but that's +that's an easy function right that's + + align:start position:0% +that's an easy function right that's + + + align:start position:0% +that's an easy function right that's +just Z for any for any point in space + + align:start position:0% +just Z for any for any point in space + + + align:start position:0% +just Z for any for any point in space +it's its distance from the XY plane is + + align:start position:0% +it's its distance from the XY plane is + + + align:start position:0% +it's its distance from the XY plane is +just its height it's its Z value so the + + align:start position:0% +just its height it's its Z value so the + + + align:start position:0% +just its height it's its Z value so the +function that we're seeking to find the + + align:start position:0% +function that we're seeking to find the + + + align:start position:0% +function that we're seeking to find the +average value of is Z and so most of the + + align:start position:0% +average value of is Z and so most of the + + + align:start position:0% +average value of is Z and so most of the +work of this problem then is gonna be in + + align:start position:0% +work of this problem then is gonna be in + + + align:start position:0% +work of this problem then is gonna be in +figuring out what the bounds are and + + align:start position:0% +figuring out what the bounds are and + + + align:start position:0% +figuring out what the bounds are and +then doing the actual integral after + + align:start position:0% +then doing the actual integral after + + + align:start position:0% +then doing the actual integral after +that so ok so let's so let's think about + + align:start position:0% +that so ok so let's so let's think about + + + align:start position:0% +that so ok so let's so let's think about +the bounce now you can integrate this + + align:start position:0% +the bounce now you can integrate this + + + align:start position:0% +the bounce now you can integrate this +tetrahedron is a nice reasonably simple + + align:start position:0% +tetrahedron is a nice reasonably simple + + + align:start position:0% +tetrahedron is a nice reasonably simple +geometric thing object so in fact it + + align:start position:0% +geometric thing object so in fact it + + + align:start position:0% +geometric thing object so in fact it +doesn't matter too much which which + + align:start position:0% +doesn't matter too much which which + + + align:start position:0% +doesn't matter too much which which +order you take your bounds in so I think + + align:start position:0% +order you take your bounds in so I think + + + align:start position:0% +order you take your bounds in so I think +I'm gonna do it in the order DZ dy DX + + align:start position:0% +I'm gonna do it in the order DZ dy DX + + + align:start position:0% +I'm gonna do it in the order DZ dy DX +you know I'll do Z first and then Y in + + align:start position:0% +you know I'll do Z first and then Y in + + + align:start position:0% +you know I'll do Z first and then Y in +the next but it doesn't matter if you + + align:start position:0% +the next but it doesn't matter if you + + + align:start position:0% +the next but it doesn't matter if you +did a different way it'll probably work + + align:start position:0% +did a different way it'll probably work + + + align:start position:0% +did a different way it'll probably work +out very similar overall and and you'll + + align:start position:0% +out very similar overall and and you'll + + + align:start position:0% +out very similar overall and and you'll +you'll still be able to compare the + + align:start position:0% +you'll still be able to compare the + + + align:start position:0% +you'll still be able to compare the +overall process so let's so let's think + + align:start position:0% +overall process so let's so let's think + + + align:start position:0% +overall process so let's so let's think +about Z yeah so in this tetrahedron as + + align:start position:0% +about Z yeah so in this tetrahedron as + + + align:start position:0% +about Z yeah so in this tetrahedron as +as the so we want Z we want to integrate + + align:start position:0% +as the so we want Z we want to integrate + + + align:start position:0% +as the so we want Z we want to integrate +with respect to Z first so we look at + + align:start position:0% +with respect to Z first so we look at + + + align:start position:0% +with respect to Z first so we look at +this tetrahedron when we say ok at a + + align:start position:0% +this tetrahedron when we say ok at a + + + align:start position:0% +this tetrahedron when we say ok at a +point x and y you know when we choose + + align:start position:0% +point x and y you know when we choose + + + align:start position:0% +point x and y you know when we choose +the x and y values what's the sort of + + align:start position:0% +the x and y values what's the sort of + + + align:start position:0% +the x and y values what's the sort of +lowest surface what's the smallest value + + align:start position:0% +lowest surface what's the smallest value + + + align:start position:0% +lowest surface what's the smallest value +Z can take and what's the upper surface + + align:start position:0% +Z can take and what's the upper surface + + + align:start position:0% +Z can take and what's the upper surface +what's the largest value Z can take so + + align:start position:0% +what's the largest value Z can take so + + + align:start position:0% +what's the largest value Z can take so +the lowest surface here is the xy-plane + + align:start position:0% +the lowest surface here is the xy-plane + + + align:start position:0% +the lowest surface here is the xy-plane +that's the bottom face of this + + align:start position:0% +that's the bottom face of this + + + align:start position:0% +that's the bottom face of this +tetrahedron and for any point for any + + align:start position:0% +tetrahedron and for any point for any + + + align:start position:0% +tetrahedron and for any point for any +choice x and y the lowest values you can + + align:start position:0% +choice x and y the lowest values you can + + + align:start position:0% +choice x and y the lowest values you can +take is when it's when it's in the + + align:start position:0% +take is when it's when it's in the + + + align:start position:0% +take is when it's when it's in the +xy-plane so when it's equal to zero so + + align:start position:0% +xy-plane so when it's equal to zero so + + + align:start position:0% +xy-plane so when it's equal to zero so +so the + + align:start position:0% +so the + + + align:start position:0% +so the +boundaries so this is gonna be equal so + + align:start position:0% +boundaries so this is gonna be equal so + + + align:start position:0% +boundaries so this is gonna be equal so +in our case so let's set this up it's + + align:start position:0% +in our case so let's set this up it's + + + align:start position:0% +in our case so let's set this up it's +gonna be an iterated integral the + + align:start position:0% +gonna be an iterated integral the + + + align:start position:0% +gonna be an iterated integral the +function we're integrating is Z and I + + align:start position:0% +function we're integrating is Z and I + + + align:start position:0% +function we're integrating is Z and I +said we'll do DZ dy DX and we just said + + align:start position:0% +said we'll do DZ dy DX and we just said + + + align:start position:0% +said we'll do DZ dy DX and we just said +that okay so the lowest value that Z + + align:start position:0% +that okay so the lowest value that Z + + + align:start position:0% +that okay so the lowest value that Z +takes the DZ is 0 so the up highest + + align:start position:0% +takes the DZ is 0 so the up highest + + + align:start position:0% +takes the DZ is 0 so the up highest +value that Z takes is when it hits this + + align:start position:0% +value that Z takes is when it hits this + + + align:start position:0% +value that Z takes is when it hits this +this top surface this plane that passes + + align:start position:0% +this top surface this plane that passes + + + align:start position:0% +this top surface this plane that passes +through the point 1 0 0 0 1 0 and 0 0 1 + + align:start position:0% +through the point 1 0 0 0 1 0 and 0 0 1 + + + align:start position:0% +through the point 1 0 0 0 1 0 and 0 0 1 +all right so we need to know the + + align:start position:0% +all right so we need to know the + + + align:start position:0% +all right so we need to know the +equation of that plane luckily that's a + + align:start position:0% +equation of that plane luckily that's a + + + align:start position:0% +equation of that plane luckily that's a +pretty easy plane to write down the + + align:start position:0% +pretty easy plane to write down the + + + align:start position:0% +pretty easy plane to write down the +equation for so this slanted surface so + + align:start position:0% +equation for so this slanted surface so + + + align:start position:0% +equation for so this slanted surface so +this slanted plane passing through the + + align:start position:0% +this slanted plane passing through the + + + align:start position:0% +this slanted plane passing through the +the 3 vertices other than the origin is + + align:start position:0% +the 3 vertices other than the origin is + + + align:start position:0% +the 3 vertices other than the origin is +the plane X plus y plus Z equals 1 all + + align:start position:0% +the plane X plus y plus Z equals 1 all + + + align:start position:0% +the plane X plus y plus Z equals 1 all +right so it's a it's a nice easy plane + + align:start position:0% +right so it's a it's a nice easy plane + + + align:start position:0% +right so it's a it's a nice easy plane +to work with and so what we want to know + + align:start position:0% +to work with and so what we want to know + + + align:start position:0% +to work with and so what we want to know +is what's the value of Z on that plane + + align:start position:0% +is what's the value of Z on that plane + + + align:start position:0% +is what's the value of Z on that plane +and so okay so we we isolate Z on one + + align:start position:0% +and so okay so we we isolate Z on one + + + align:start position:0% +and so okay so we we isolate Z on one +side and we bring everything else over + + align:start position:0% +side and we bring everything else over + + + align:start position:0% +side and we bring everything else over +so we we have that that that top value + + align:start position:0% +so we we have that that that top value + + + align:start position:0% +so we we have that that that top value +of Z the largest value of Z that Z can + + align:start position:0% +of Z the largest value of Z that Z can + + + align:start position:0% +of Z the largest value of Z that Z can +take when x and y are fixed is 1 minus X + + align:start position:0% +take when x and y are fixed is 1 minus X + + + align:start position:0% +take when x and y are fixed is 1 minus X +minus y so that's what goes up here 1 + + align:start position:0% +minus y so that's what goes up here 1 + + + align:start position:0% +minus y so that's what goes up here 1 +minus s minus y so that's the biggest + + align:start position:0% +minus s minus y so that's the biggest + + + align:start position:0% +minus s minus y so that's the biggest +values you can take ok good so now we + + align:start position:0% +values you can take ok good so now we + + + align:start position:0% +values you can take ok good so now we +need to figure out what the bounds on Y + + align:start position:0% +need to figure out what the bounds on Y + + + align:start position:0% +need to figure out what the bounds on Y +are in terms of X so what I like to do + + align:start position:0% +are in terms of X so what I like to do + + + align:start position:0% +are in terms of X so what I like to do +in this case is I like to draw a + + align:start position:0% +in this case is I like to draw a + + + align:start position:0% +in this case is I like to draw a +projection of your of your surface so + + align:start position:0% +projection of your of your surface so + + + align:start position:0% +projection of your of your surface so +then your in in a sort of + + align:start position:0% +then your in in a sort of + + + align:start position:0% +then your in in a sort of +two-dimensional world and then you can + + align:start position:0% +two-dimensional world and then you can + + + align:start position:0% +two-dimensional world and then you can +look at that image more easily so so + + align:start position:0% +look at that image more easily so so + + + align:start position:0% +look at that image more easily so so +what we're gonna do is we're gonna look + + align:start position:0% +what we're gonna do is we're gonna look + + + align:start position:0% +what we're gonna do is we're gonna look +at this tetrahedron and we're gonna + + align:start position:0% +at this tetrahedron and we're gonna + + + align:start position:0% +at this tetrahedron and we're gonna +imagine projecting it down into the XY + + align:start position:0% +imagine projecting it down into the XY + + + align:start position:0% +imagine projecting it down into the XY +plane so for every point in the + + align:start position:0% +plane so for every point in the + + + align:start position:0% +plane so for every point in the +tetrahedron we're gonna draw a dot below + + align:start position:0% +tetrahedron we're gonna draw a dot below + + + align:start position:0% +tetrahedron we're gonna draw a dot below +it in the XY plane we're gonna look at + + align:start position:0% +it in the XY plane we're gonna look at + + + align:start position:0% +it in the XY plane we're gonna look at +that set of dots so that what that's + + align:start position:0% +that set of dots so that what that's + + + align:start position:0% +that set of dots so that what that's +going to give us is this this in this + + align:start position:0% +going to give us is this this in this + + + align:start position:0% +going to give us is this this in this +case it's gonna give us this bottom face + + align:start position:0% +case it's gonna give us this bottom face + + + align:start position:0% +case it's gonna give us this bottom face +of the tetrahedron every point of the + + align:start position:0% +of the tetrahedron every point of the + + + align:start position:0% +of the tetrahedron every point of the +tetrahedron is above its bottom face + + align:start position:0% +tetrahedron is above its bottom face + + + align:start position:0% +tetrahedron is above its bottom face +that's not true for every tetrahedron + + align:start position:0% +that's not true for every tetrahedron + + + align:start position:0% +that's not true for every tetrahedron +but it's true for this one so the region + + align:start position:0% +but it's true for this one so the region + + + align:start position:0% +but it's true for this one so the region +that we're interested in is that bottom + + align:start position:0% +that we're interested in is that bottom + + + align:start position:0% +that we're interested in is that bottom +face so I'm gonna draw another picture + + align:start position:0% +face so I'm gonna draw another picture + + + align:start position:0% +face so I'm gonna draw another picture +of it over over on my left here so that + + align:start position:0% +of it over over on my left here so that + + + align:start position:0% +of it over over on my left here so that +region is the region that has vertices 0 + + align:start position:0% +region is the region that has vertices 0 + + + align:start position:0% +region is the region that has vertices 0 +0 & 1 0 0 + + align:start position:0% +0 & 1 0 0 + + + align:start position:0% +0 & 1 0 0 +and sorry 0 0 1 0 & 0 1 so it's this + + align:start position:0% +and sorry 0 0 1 0 & 0 1 so it's this + + + align:start position:0% +and sorry 0 0 1 0 & 0 1 so it's this +triangle and this bottom edge of the + + align:start position:0% +triangle and this bottom edge of the + + + align:start position:0% +triangle and this bottom edge of the +triangle is the line y equals 0 this + + align:start position:0% +triangle is the line y equals 0 this + + + align:start position:0% +triangle is the line y equals 0 this +left edge is the line x equals 0 and + + align:start position:0% +left edge is the line x equals 0 and + + + align:start position:0% +left edge is the line x equals 0 and +this slanted line is the line x plus y + + align:start position:0% +this slanted line is the line x plus y + + + align:start position:0% +this slanted line is the line x plus y +equals 1 ok so this is that this is that + + align:start position:0% +equals 1 ok so this is that this is that + + + align:start position:0% +equals 1 ok so this is that this is that +same bottom face that we just drew but + + align:start position:0% +same bottom face that we just drew but + + + align:start position:0% +same bottom face that we just drew but +now I've you know I've changed my axes + + align:start position:0% +now I've you know I've changed my axes + + + align:start position:0% +now I've you know I've changed my axes +to our usual 2-dimensional Direction xn + + align:start position:0% +to our usual 2-dimensional Direction xn + + + align:start position:0% +to our usual 2-dimensional Direction xn +with X to the right and Y up okay so we + + align:start position:0% +with X to the right and Y up okay so we + + + align:start position:0% +with X to the right and Y up okay so we +need to figure out now so we're doing dy + + align:start position:0% +need to figure out now so we're doing dy + + + align:start position:0% +need to figure out now so we're doing dy +next so we need to figure out for a + + align:start position:0% +next so we need to figure out for a + + + align:start position:0% +next so we need to figure out for a +fixed value of x what are the bounds on + + align:start position:0% +fixed value of x what are the bounds on + + + align:start position:0% +fixed value of x what are the bounds on +Y and so okay so we see from this + + align:start position:0% +Y and so okay so we see from this + + + align:start position:0% +Y and so okay so we see from this +picture that for any for any fixed value + + align:start position:0% +picture that for any for any fixed value + + + align:start position:0% +picture that for any for any fixed value +of x Y goes from 0 this the x-axis up to + + align:start position:0% +of x Y goes from 0 this the x-axis up to + + + align:start position:0% +of x Y goes from 0 this the x-axis up to +this line okay so on the x-axis Y takes + + align:start position:0% +this line okay so on the x-axis Y takes + + + align:start position:0% +this line okay so on the x-axis Y takes +the value 0 and on this line Y takes the + + align:start position:0% +the value 0 and on this line Y takes the + + + align:start position:0% +the value 0 and on this line Y takes the +value 1 minus X finally our our + + align:start position:0% +value 1 minus X finally our our + + + align:start position:0% +value 1 minus X finally our our +outermost variable of integration is X + + align:start position:0% +outermost variable of integration is X + + + align:start position:0% +outermost variable of integration is X +and so we need to know what are the + + align:start position:0% +and so we need to know what are the + + + align:start position:0% +and so we need to know what are the +absolute largest and smallest values + + align:start position:0% +absolute largest and smallest values + + + align:start position:0% +absolute largest and smallest values +that X take that X takes so we okay so + + align:start position:0% +that X take that X takes so we okay so + + + align:start position:0% +that X take that X takes so we okay so +we can do that looking either at this + + align:start position:0% +we can do that looking either at this + + + align:start position:0% +we can do that looking either at this +picture or looking at our original + + align:start position:0% +picture or looking at our original + + + align:start position:0% +picture or looking at our original +picture + + align:start position:0% +picture + + + align:start position:0% +picture +either way it's it's not hard to see + + align:start position:0% +either way it's it's not hard to see + + + align:start position:0% +either way it's it's not hard to see +that X just goes between 0 & 1 the + + align:start position:0% +that X just goes between 0 & 1 the + + + align:start position:0% +that X just goes between 0 & 1 the +smallest value that X takes in this + + align:start position:0% +smallest value that X takes in this + + + align:start position:0% +smallest value that X takes in this +tetrahedron is 0 the largest value it + + align:start position:0% +tetrahedron is 0 the largest value it + + + align:start position:0% +tetrahedron is 0 the largest value it +takes is 1 so that's our integral that + + align:start position:0% +takes is 1 so that's our integral that + + + align:start position:0% +takes is 1 so that's our integral that +we have to compute so that's not that + + align:start position:0% +we have to compute so that's not that + + + align:start position:0% +we have to compute so that's not that +bad at all so now you have to go through + + align:start position:0% +bad at all so now you have to go through + + + align:start position:0% +bad at all so now you have to go through +and you have to actually integrate this + + align:start position:0% +and you have to actually integrate this + + + align:start position:0% +and you have to actually integrate this +yeah and so I'm gonna you know look at + + align:start position:0% +yeah and so I'm gonna you know look at + + + align:start position:0% +yeah and so I'm gonna you know look at +my notes just to make sure I don't make + + align:start position:0% +my notes just to make sure I don't make + + + align:start position:0% +my notes just to make sure I don't make +any big arithmetic mistakes so let's see + + align:start position:0% +any big arithmetic mistakes so let's see + + + align:start position:0% +any big arithmetic mistakes so let's see +so we've got so we now we do these one + + align:start position:0% +so we've got so we now we do these one + + + align:start position:0% +so we've got so we now we do these one +at a time so this innermost integral is + + align:start position:0% +at a time so this innermost integral is + + + align:start position:0% +at a time so this innermost integral is +an integral of zdz ok well that's easy + + align:start position:0% +an integral of zdz ok well that's easy + + + align:start position:0% +an integral of zdz ok well that's easy +that's Z squared over 2 and then we're + + align:start position:0% +that's Z squared over 2 and then we're + + + align:start position:0% +that's Z squared over 2 and then we're +taking Z squared over 2 between 0 & 1 + + align:start position:0% +taking Z squared over 2 between 0 & 1 + + + align:start position:0% +taking Z squared over 2 between 0 & 1 +minus X minus y so this innermost + + align:start position:0% +minus X minus y so this innermost + + + align:start position:0% +minus X minus y so this innermost +integral is + + align:start position:0% + + + + align:start position:0% + +Z squared over 2 between 0 & 1 minus X + + align:start position:0% +Z squared over 2 between 0 & 1 minus X + + + align:start position:0% +Z squared over 2 between 0 & 1 minus X +minus y so that's equal to so the + + align:start position:0% +minus y so that's equal to so the + + + align:start position:0% +minus y so that's equal to so the +innermost integral gives us 1 minus X + + align:start position:0% +innermost integral gives us 1 minus X + + + align:start position:0% +innermost integral gives us 1 minus X +minus y squared over 2 so that's what we + + align:start position:0% +minus y squared over 2 so that's what we + + + align:start position:0% +minus y squared over 2 so that's what we +get for the innermost integral so our + + align:start position:0% +get for the innermost integral so our + + + align:start position:0% +get for the innermost integral so our +integral that we're looking at then is + + align:start position:0% +integral that we're looking at then is + + + align:start position:0% +integral that we're looking at then is +equal to well it's the integral as X + + align:start position:0% +equal to well it's the integral as X + + + align:start position:0% +equal to well it's the integral as X +goes from 0 to 1 of the integral as Y + + align:start position:0% +goes from 0 to 1 of the integral as Y + + + align:start position:0% +goes from 0 to 1 of the integral as Y +goes from 0 to 1 minus X of this + + align:start position:0% +goes from 0 to 1 minus X of this + + + align:start position:0% +goes from 0 to 1 minus X of this +integrand so this was the inner one let + + align:start position:0% +integrand so this was the inner one let + + + align:start position:0% +integrand so this was the inner one let +me write that inner that's what I've got + + align:start position:0% +me write that inner that's what I've got + + + align:start position:0% +me write that inner that's what I've got +here just integrating Z with respect to + + align:start position:0% +here just integrating Z with respect to + + + align:start position:0% +here just integrating Z with respect to +Z gives me Z squared over 2 and then I + + align:start position:0% +Z gives me Z squared over 2 and then I + + + align:start position:0% +Z gives me Z squared over 2 and then I +evaluated at the bounds of the integral + + align:start position:0% +evaluated at the bounds of the integral + + + align:start position:0% +evaluated at the bounds of the integral +ok so now I need to do the middle one so + + align:start position:0% +ok so now I need to do the middle one so + + + align:start position:0% +ok so now I need to do the middle one so +let's do that up here so I need to + + align:start position:0% +let's do that up here so I need to + + + align:start position:0% +let's do that up here so I need to +compute so this is the middle integral + + align:start position:0% +compute so this is the middle integral + + + align:start position:0% +compute so this is the middle integral +so I need to compute the integral so now + + align:start position:0% +so I need to compute the integral so now + + + align:start position:0% +so I need to compute the integral so now +I take the bounds so the middle one is y + + align:start position:0% +I take the bounds so the middle one is y + + + align:start position:0% +I take the bounds so the middle one is y +and the bounds are from 0 to 1 minus x 0 + + align:start position:0% +and the bounds are from 0 to 1 minus x 0 + + + align:start position:0% +and the bounds are from 0 to 1 minus x 0 +to 1 minus x of the inner integrand so + + align:start position:0% +to 1 minus x of the inner integrand so + + + align:start position:0% +to 1 minus x of the inner integrand so +this thing that I just the inner + + align:start position:0% +this thing that I just the inner + + + align:start position:0% +this thing that I just the inner +integral this thing that I just computed + + align:start position:0% +integral this thing that I just computed + + + align:start position:0% +integral this thing that I just computed +so that's of 1 minus X minus y squared + + align:start position:0% +so that's of 1 minus X minus y squared + + + align:start position:0% +so that's of 1 minus X minus y squared +over 2 dy okay + + align:start position:0% +over 2 dy okay + + + align:start position:0% +over 2 dy okay +so all right so this isn't that bad this + + align:start position:0% +so all right so this isn't that bad this + + + align:start position:0% +so all right so this isn't that bad this +is a quadratic polynomial in Y and so + + align:start position:0% +is a quadratic polynomial in Y and so + + + align:start position:0% +is a quadratic polynomial in Y and so +it's not terribly hard to see I'm sort + + align:start position:0% +it's not terribly hard to see I'm sort + + + align:start position:0% +it's not terribly hard to see I'm sort +of running out a little bit out of board + + align:start position:0% +of running out a little bit out of board + + + align:start position:0% +of running out a little bit out of board +space so I'm not gonna you know give you + + align:start position:0% +space so I'm not gonna you know give you + + + align:start position:0% +space so I'm not gonna you know give you +a full detailed explanation but it's not + + align:start position:0% +a full detailed explanation but it's not + + + align:start position:0% +a full detailed explanation but it's not +hard to see I think that that this + + align:start position:0% +hard to see I think that that this + + + align:start position:0% +hard to see I think that that this +integral is that the integral of 1 minus + + align:start position:0% +integral is that the integral of 1 minus + + + align:start position:0% +integral is that the integral of 1 minus +X minus y squared over 2 is 1 minus X + + align:start position:0% +X minus y squared over 2 is 1 minus X + + + align:start position:0% +X minus y squared over 2 is 1 minus X +minus y with respect to Y of course of + + align:start position:0% +minus y with respect to Y of course of + + + align:start position:0% +minus y with respect to Y of course of +is 1 minus X minus y cubed over 3 but + + align:start position:0% +is 1 minus X minus y cubed over 3 but + + + align:start position:0% +is 1 minus X minus y cubed over 3 but +it's negative because the sign here is + + align:start position:0% +it's negative because the sign here is + + + align:start position:0% +it's negative because the sign here is +negative and you could check by + + align:start position:0% +negative and you could check by + + + align:start position:0% +negative and you could check by +differentiating this and seeing that you + + align:start position:0% +differentiating this and seeing that you + + + align:start position:0% +differentiating this and seeing that you +get that and okay so we have to evaluate + + align:start position:0% +get that and okay so we have to evaluate + + + align:start position:0% +get that and okay so we have to evaluate +that as Y goes from 0 to 1 minus X so + + align:start position:0% +that as Y goes from 0 to 1 minus X so + + + align:start position:0% +that as Y goes from 0 to 1 minus X so +what do we get + + align:start position:0% +what do we get + + + align:start position:0% +what do we get +well when Y is equal to 1 minus X this + + align:start position:0% +well when Y is equal to 1 minus X this + + + align:start position:0% +well when Y is equal to 1 minus X this +is 0 + + align:start position:0% +is 0 + + + align:start position:0% +is 0 +so we get zero minus and when Y is equal + + align:start position:0% +so we get zero minus and when Y is equal + + + align:start position:0% +so we get zero minus and when Y is equal +to zero this is minus 1 minus X quantity + + align:start position:0% +to zero this is minus 1 minus X quantity + + + align:start position:0% +to zero this is minus 1 minus X quantity +cubed over 6 so this is so it's minus -1 + + align:start position:0% +cubed over 6 so this is so it's minus -1 + + + align:start position:0% +cubed over 6 so this is so it's minus -1 +minus X cubed over 6 so that's just 1 + + align:start position:0% +minus X cubed over 6 so that's just 1 + + + align:start position:0% +minus X cubed over 6 so that's just 1 +minus X cubed over 6 and so finally the + + align:start position:0% +minus X cubed over 6 and so finally the + + + align:start position:0% +minus X cubed over 6 and so finally the +outer integral outermost integral is we + + align:start position:0% +outer integral outermost integral is we + + + align:start position:0% +outer integral outermost integral is we +you know take the inner two integrals + + align:start position:0% +you know take the inner two integrals + + + align:start position:0% +you know take the inner two integrals +and we integrate them with respect to X + + align:start position:0% +and we integrate them with respect to X + + + align:start position:0% +and we integrate them with respect to X +as X goes from zero to one so it's the + + align:start position:0% +as X goes from zero to one so it's the + + + align:start position:0% +as X goes from zero to one so it's the +integral from 0 to 1 of 1 minus X cubed + + align:start position:0% +integral from 0 to 1 of 1 minus X cubed + + + align:start position:0% +integral from 0 to 1 of 1 minus X cubed +over 6 DX and that's gonna equal alright + + align:start position:0% +over 6 DX and that's gonna equal alright + + + align:start position:0% +over 6 DX and that's gonna equal alright +I've run out of space so that integral + + align:start position:0% +I've run out of space so that integral + + + align:start position:0% +I've run out of space so that integral +is 1 over 24 all right except I've done + + align:start position:0% +is 1 over 24 all right except I've done + + + align:start position:0% +is 1 over 24 all right except I've done +something wrong right at the beginning I + + align:start position:0% +something wrong right at the beginning I + + + align:start position:0% +something wrong right at the beginning I +hope you all caught me right I had this + + align:start position:0% +hope you all caught me right I had this + + + align:start position:0% +hope you all caught me right I had this +one over V factor here and it + + align:start position:0% +one over V factor here and it + + + align:start position:0% +one over V factor here and it +disappeared right I forgot about this 1 + + align:start position:0% +disappeared right I forgot about this 1 + + + align:start position:0% +disappeared right I forgot about this 1 +over V so over here I should have + + align:start position:0% +over V so over here I should have + + + align:start position:0% +over V so over here I should have +written a 1 over V right in front of + + align:start position:0% +written a 1 over V right in front of + + + align:start position:0% +written a 1 over V right in front of +that integral and so what that means is + + align:start position:0% +that integral and so what that means is + + + align:start position:0% +that integral and so what that means is +that 1 over 24 so okay so I've computed + + align:start position:0% +that 1 over 24 so okay so I've computed + + + align:start position:0% +that 1 over 24 so okay so I've computed +correctly computed 1 over 24 as the + + align:start position:0% +correctly computed 1 over 24 as the + + + align:start position:0% +correctly computed 1 over 24 as the +value of my triple integral but the + + align:start position:0% +value of my triple integral but the + + + align:start position:0% +value of my triple integral but the +average height here isn't 1 over 24 it's + + align:start position:0% +average height here isn't 1 over 24 it's + + + align:start position:0% +average height here isn't 1 over 24 it's +1 over 24 V alright so so the average + + align:start position:0% +1 over 24 V alright so so the average + + + align:start position:0% +1 over 24 V alright so so the average +height is 1 over 24 V so we need to go + + align:start position:0% +height is 1 over 24 V so we need to go + + + align:start position:0% +height is 1 over 24 V so we need to go +and we need to look at our tetrahedron + + align:start position:0% +and we need to look at our tetrahedron + + + align:start position:0% +and we need to look at our tetrahedron +and figure out what its volume is so if + + align:start position:0% +and figure out what its volume is so if + + + align:start position:0% +and figure out what its volume is so if +we come over here see our tetrahedron + + align:start position:0% +we come over here see our tetrahedron + + + align:start position:0% +we come over here see our tetrahedron +now this is a nice simple tetrahedron + + align:start position:0% +now this is a nice simple tetrahedron + + + align:start position:0% +now this is a nice simple tetrahedron +volume of a tetrahedron is 1/2 know 1/3 + + align:start position:0% +volume of a tetrahedron is 1/2 know 1/3 + + + align:start position:0% +volume of a tetrahedron is 1/2 know 1/3 +the area of the base times the height + + align:start position:0% +the area of the base times the height + + + align:start position:0% +the area of the base times the height +right so this is a nice easy tetrahedron + + align:start position:0% +right so this is a nice easy tetrahedron + + + align:start position:0% +right so this is a nice easy tetrahedron +its height is 1 its base is a right + + align:start position:0% +its height is 1 its base is a right + + + align:start position:0% +its height is 1 its base is a right +triangle whose legs are both 1 so the + + align:start position:0% +triangle whose legs are both 1 so the + + + align:start position:0% +triangle whose legs are both 1 so the +base area is 1/2 so the volume is 1/6 + + align:start position:0% +base area is 1/2 so the volume is 1/6 + + + align:start position:0% +base area is 1/2 so the volume is 1/6 +all right so if the volume is 1/6 we + + align:start position:0% +all right so if the volume is 1/6 we + + + align:start position:0% +all right so if the volume is 1/6 we +said the average value is 1 over 24 V so + + align:start position:0% +said the average value is 1 over 24 V so + + + align:start position:0% +said the average value is 1 over 24 V so +that works out to 1 over 4 so let me + + align:start position:0% +that works out to 1 over 4 so let me + + + align:start position:0% +that works out to 1 over 4 so let me +write that just in this space so the + + align:start position:0% +write that just in this space so the + + + align:start position:0% +write that just in this space so the +average + + align:start position:0% + + + + align:start position:0% + +hi then is one over four so that's gonna + + align:start position:0% +hi then is one over four so that's gonna + + + align:start position:0% +hi then is one over four so that's gonna +be our final answer okay so let's just + + align:start position:0% +be our final answer okay so let's just + + + align:start position:0% +be our final answer okay so let's just +recap briefly what we did we had an + + align:start position:0% +recap briefly what we did we had an + + + align:start position:0% +recap briefly what we did we had an +average value problem that we started + + align:start position:0% +average value problem that we started + + + align:start position:0% +average value problem that we started +with so we use this general formula for + + align:start position:0% +with so we use this general formula for + + + align:start position:0% +with so we use this general formula for +average value problems when you have a + + align:start position:0% +average value problems when you have a + + + align:start position:0% +average value problems when you have a +function f that you want to take its + + align:start position:0% +function f that you want to take its + + + align:start position:0% +function f that you want to take its +average value of over over a region R + + align:start position:0% +average value of over over a region R + + + align:start position:0% +average value of over over a region R +what do you do will you take one over + + align:start position:0% +what do you do will you take one over + + + align:start position:0% +what do you do will you take one over +the volume of the region times the + + align:start position:0% +the volume of the region times the + + + align:start position:0% +the volume of the region times the +triple integral of your function f with + + align:start position:0% +triple integral of your function f with + + + align:start position:0% +triple integral of your function f with +respect to volume over that region okay + + align:start position:0% +respect to volume over that region okay + + + align:start position:0% +respect to volume over that region okay +so this is this is the average value in + + align:start position:0% +so this is this is the average value in + + + align:start position:0% +so this is this is the average value in +general in our particular case the the + + align:start position:0% +general in our particular case the the + + + align:start position:0% +general in our particular case the the +function was the height it was Z and + + align:start position:0% +function was the height it was Z and + + + align:start position:0% +function was the height it was Z and +then you have to set about choosing the + + align:start position:0% +then you have to set about choosing the + + + align:start position:0% +then you have to set about choosing the +proper balance for your integrals so in + + align:start position:0% +proper balance for your integrals so in + + + align:start position:0% +proper balance for your integrals so in +this case you know you so you choose + + align:start position:0% +this case you know you so you choose + + + align:start position:0% +this case you know you so you choose +some order of integration based on the + + align:start position:0% +some order of integration based on the + + + align:start position:0% +some order of integration based on the +region in this particular case it's a + + align:start position:0% +region in this particular case it's a + + + align:start position:0% +region in this particular case it's a +nice simple region it doesn't matter too + + align:start position:0% +nice simple region it doesn't matter too + + + align:start position:0% +nice simple region it doesn't matter too +much what order you choose so you have + + align:start position:0% +much what order you choose so you have + + + align:start position:0% +much what order you choose so you have +you know so I chose GZ dy/dx and then + + align:start position:0% +you know so I chose GZ dy/dx and then + + + align:start position:0% +you know so I chose GZ dy/dx and then +what does that mean so for the innermost + + align:start position:0% +what does that mean so for the innermost + + + align:start position:0% +what does that mean so for the innermost +one you look at your original solid so + + align:start position:0% +one you look at your original solid so + + + align:start position:0% +one you look at your original solid so +I'm gonna go back and look at this + + align:start position:0% +I'm gonna go back and look at this + + + align:start position:0% +I'm gonna go back and look at this +picture again so for your innermost + + align:start position:0% +picture again so for your innermost + + + align:start position:0% +picture again so for your innermost +variable you say so if it's Z you say + + align:start position:0% +variable you say so if it's Z you say + + + align:start position:0% +variable you say so if it's Z you say +okay so when i fix X&Y what's the bottom + + align:start position:0% +okay so when i fix X&Y what's the bottom + + + align:start position:0% +okay so when i fix X&Y what's the bottom +surface and what's the top surface for z + + align:start position:0% +surface and what's the top surface for z + + + align:start position:0% +surface and what's the top surface for z +you know when i solve that for Z in + + align:start position:0% +you know when i solve that for Z in + + + align:start position:0% +you know when i solve that for Z in +terms of x and y so here that was that + + align:start position:0% +terms of x and y so here that was that + + + align:start position:0% +terms of x and y so here that was that +the plane Z equals zero and the plane Z + + align:start position:0% +the plane Z equals zero and the plane Z + + + align:start position:0% +the plane Z equals zero and the plane Z +equals one minus X minus y so that + + align:start position:0% +equals one minus X minus y so that + + + align:start position:0% +equals one minus X minus y so that +explains my bounds over here why they + + align:start position:0% +explains my bounds over here why they + + + align:start position:0% +explains my bounds over here why they +were 0 and 1 minus X minus y then when + + align:start position:0% +were 0 and 1 minus X minus y then when + + + align:start position:0% +were 0 and 1 minus X minus y then when +you go to your next variable in this + + align:start position:0% +you go to your next variable in this + + + align:start position:0% +you go to your next variable in this +case it was y what do you do well you + + align:start position:0% +case it was y what do you do well you + + + align:start position:0% +case it was y what do you do well you +you first you project to eliminate this + + align:start position:0% +you first you project to eliminate this + + + align:start position:0% +you first you project to eliminate this +first variable so you project your + + align:start position:0% +first variable so you project your + + + align:start position:0% +first variable so you project your +region down well down in this case + + align:start position:0% +region down well down in this case + + + align:start position:0% +region down well down in this case +because it's Z so you project in the Z + + align:start position:0% +because it's Z so you project in the Z + + + align:start position:0% +because it's Z so you project in the Z +direction and you draw the sort of + + align:start position:0% +direction and you draw the sort of + + + align:start position:0% +direction and you draw the sort of +shadow of your region so this was what I + + align:start position:0% +shadow of your region so this was what I + + + align:start position:0% +shadow of your region so this was what I +drew here this is the shadow of my + + align:start position:0% +drew here this is the shadow of my + + + align:start position:0% +drew here this is the shadow of my +region in the XY plane after I projected + + align:start position:0% +region in the XY plane after I projected + + + align:start position:0% +region in the XY plane after I projected +it and then you do the same thing so now + + align:start position:0% +it and then you do the same thing so now + + + align:start position:0% +it and then you do the same thing so now +this is back and just like what you did + + align:start position:0% +this is back and just like what you did + + + align:start position:0% +this is back and just like what you did +when you had to find bounds for double + + align:start position:0% +when you had to find bounds for double + + + align:start position:0% +when you had to find bounds for double +integrals when you wrote them as + + align:start position:0% +integrals when you wrote them as + + + align:start position:0% +integrals when you wrote them as +iterated integrals a few a few lectures + + align:start position:0% +iterated integrals a few a few lectures + + + align:start position:0% +iterated integrals a few a few lectures +ago + + align:start position:0% +ago + + + align:start position:0% +ago +so okay and so then you do the same + + align:start position:0% +so okay and so then you do the same + + + align:start position:0% +so okay and so then you do the same +thing so then + + align:start position:0% +thing so then + + + align:start position:0% +thing so then +in this case I was next integrating with + + align:start position:0% +in this case I was next integrating with + + + align:start position:0% +in this case I was next integrating with +respect to Y so I needed to find the + + align:start position:0% +respect to Y so I needed to find the + + + align:start position:0% +respect to Y so I needed to find the +bounds on Y with respect to X so I + + align:start position:0% +bounds on Y with respect to X so I + + + align:start position:0% +bounds on Y with respect to X so I +needed to look in this picture at the + + align:start position:0% +needed to look in this picture at the + + + align:start position:0% +needed to look in this picture at the +bottom edge and the top edge of this + + align:start position:0% +bottom edge and the top edge of this + + + align:start position:0% +bottom edge and the top edge of this +region and okay and then your outermost + + align:start position:0% +region and okay and then your outermost + + + align:start position:0% +region and okay and then your outermost +variable you look at its absolute bounce + + align:start position:0% +variable you look at its absolute bounce + + + align:start position:0% +variable you look at its absolute bounce +so the largest and smallest value it + + align:start position:0% +so the largest and smallest value it + + + align:start position:0% +so the largest and smallest value it +takes on the region so then okay then + + align:start position:0% +takes on the region so then okay then + + + align:start position:0% +takes on the region so then okay then +you have an iterated integral and you + + align:start position:0% +you have an iterated integral and you + + + align:start position:0% +you have an iterated integral and you +evaluate it by successive integrations + + align:start position:0% +evaluate it by successive integrations + + + align:start position:0% +evaluate it by successive integrations +okay so that was what we did we just did + + align:start position:0% +okay so that was what we did we just did + + + align:start position:0% +okay so that was what we did we just did +the the three integrals starting from + + align:start position:0% +the the three integrals starting from + + + align:start position:0% +the the three integrals starting from +the inside and working our way out \ No newline at end of file diff --git a/cyQZP23YbCY.txt b/cyQZP23YbCY.txt new file mode 100644 index 0000000000000000000000000000000000000000..a8264b7bfc097c84103db4eab5015b7663fc0e66 --- /dev/null +++ b/cyQZP23YbCY.txt @@ -0,0 +1,11371 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license + + align:start position:0% +a Creative Commons license + + + align:start position:0% +a Creative Commons license +your support will help MIT + + align:start position:0% +your support will help MIT + + + align:start position:0% +your support will help MIT +OpenCourseWare continue to offer high + + align:start position:0% +OpenCourseWare continue to offer high + + + align:start position:0% +OpenCourseWare continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +I'm going through sounds good this was + + align:start position:0% +I'm going through sounds good this was + + + align:start position:0% +I'm going through sounds good this was +going to be a couple of hours plus of + + align:start position:0% +going to be a couple of hours plus of + + + align:start position:0% +going to be a couple of hours plus of +basic machine learning ok and I want to + + align:start position:0% +basic machine learning ok and I want to + + + align:start position:0% +basic machine learning ok and I want to +emphasize a bit the word basic because + + align:start position:0% +emphasize a bit the word basic because + + + align:start position:0% +emphasize a bit the word basic because +really I tried to just stick to the + + align:start position:0% +really I tried to just stick to the + + + align:start position:0% +really I tried to just stick to the +essentials or things that I would think + + align:start position:0% +essentials or things that I would think + + + align:start position:0% +essentials or things that I would think +of essentials to just start suppose that + + align:start position:0% +of essentials to just start suppose that + + + align:start position:0% +of essentials to just start suppose that +you have zero knowledge of machine + + align:start position:0% +you have zero knowledge of machine + + + align:start position:0% +you have zero knowledge of machine +learning and you just want to start from + + align:start position:0% +learning and you just want to start from + + + align:start position:0% +learning and you just want to start from +zero okay so if you already had classes + + align:start position:0% +zero okay so if you already had classes + + + align:start position:0% +zero okay so if you already had classes +in machine learning you might just find + + align:start position:0% +in machine learning you might just find + + + align:start position:0% +in machine learning you might just find +this little bit boring or at least kind + + align:start position:0% +this little bit boring or at least kind + + + align:start position:0% +this little bit boring or at least kind +of rehearsing things that you already + + align:start position:0% +of rehearsing things that you already + + + align:start position:0% +of rehearsing things that you already +know the idea of looking at machine + + align:start position:0% +know the idea of looking at machine + + + align:start position:0% +know the idea of looking at machine +learning these days is come from at + + align:start position:0% +learning these days is come from at + + + align:start position:0% +learning these days is come from at +least two different perspective the + + align:start position:0% +least two different perspective the + + + align:start position:0% +least two different perspective the +first one is for you for those of you + + align:start position:0% +first one is for you for those of you + + + align:start position:0% +first one is for you for those of you +probably most of you there interest to + + align:start position:0% +probably most of you there interest to + + + align:start position:0% +probably most of you there interest to +develop intelligent systems in a very + + align:start position:0% +develop intelligent systems in a very + + + align:start position:0% +develop intelligent systems in a very +broad sense what happened in the last + + align:start position:0% +broad sense what happened in the last + + + align:start position:0% +broad sense what happened in the last +few years that there's been a kind of + + align:start position:0% +few years that there's been a kind of + + + align:start position:0% +few years that there's been a kind of +data driven revolution where system that + + align:start position:0% +data driven revolution where system that + + + align:start position:0% +data driven revolution where system that +are trained rather that programmed start + + align:start position:0% +are trained rather that programmed start + + + align:start position:0% +are trained rather that programmed start +to be the key engines to solve tasks and + + align:start position:0% +to be the key engines to solve tasks and + + + align:start position:0% +to be the key engines to solve tasks and +here there is just some pictures that + + align:start position:0% +here there is just some pictures that + + + align:start position:0% +here there is just some pictures that +are probably outdated like robotics you + + align:start position:0% +are probably outdated like robotics you + + + align:start position:0% +are probably outdated like robotics you +know we have Siri on our phone we hear + + align:start position:0% +know we have Siri on our phone we hear + + + align:start position:0% +know we have Siri on our phone we hear +about self-driving cars in all this + + align:start position:0% +about self-driving cars in all this + + + align:start position:0% +about self-driving cars in all this +systems one key engine is providing data + + align:start position:0% +systems one key engine is providing data + + + align:start position:0% +systems one key engine is providing data +to the system to essentially try to + + align:start position:0% +to the system to essentially try to + + + align:start position:0% +to the system to essentially try to +learn how to solve a task and so one + + align:start position:0% +learn how to solve a task and so one + + + align:start position:0% +learn how to solve a task and so one +idea of this class is try to see what + + align:start position:0% +idea of this class is try to see what + + + align:start position:0% +idea of this class is try to see what +does it mean to learn and this the + + align:start position:0% +does it mean to learn and this the + + + align:start position:0% +does it mean to learn and this the +moment that you know you start to use + + align:start position:0% +moment that you know you start to use + + + align:start position:0% +moment that you know you start to use +data to solve complex tasks then there + + align:start position:0% +data to solve complex tasks then there + + + align:start position:0% +data to solve complex tasks then there +is a natural connection with what today + + align:start position:0% +is a natural connection with what today + + + align:start position:0% +is a natural connection with what today +is called data science which is somewhat + + align:start position:0% +is called data science which is somewhat + + + align:start position:0% +is called data science which is somewhat +a Paris want you know renovated version + + align:start position:0% +a Paris want you know renovated version + + + align:start position:0% +a Paris want you know renovated version +of the word that you used to call what + + align:start position:0% +of the word that you used to call what + + + align:start position:0% +of the word that you used to call what +we used to call just statistics so + + align:start position:0% +we used to call just statistics so + + + align:start position:0% +we used to call just statistics so +basically we start to have tons of data + + align:start position:0% +basically we start to have tons of data + + + align:start position:0% +basically we start to have tons of data +of all kinds there are very easy to + + align:start position:0% +of all kinds there are very easy to + + + align:start position:0% +of all kinds there are very easy to +collect and we are starving for + + align:start position:0% +collect and we are starving for + + + align:start position:0% +collect and we are starving for +knowledge and try to extract information + + align:start position:0% +knowledge and try to extract information + + + align:start position:0% +knowledge and try to extract information +from these data and as it turns out many + + align:start position:0% +from these data and as it turns out many + + + align:start position:0% +from these data and as it turns out many +of the techniques that are used to + + align:start position:0% +of the techniques that are used to + + + align:start position:0% +of the techniques that are used to +develop intelligent system are the same + + align:start position:0% +develop intelligent system are the same + + + align:start position:0% +develop intelligent system are the same +very taken + + align:start position:0% +very taken + + + align:start position:0% +very taken +that you can use to try to extract + + align:start position:0% +that you can use to try to extract + + + align:start position:0% +that you can use to try to extract +relevant information patterns data from + + align:start position:0% +relevant information patterns data from + + + align:start position:0% +relevant information patterns data from +your data so what we want to do today is + + align:start position:0% +your data so what we want to do today is + + + align:start position:0% +your data so what we want to do today is +try to see a bit what's in the middle + + align:start position:0% +try to see a bit what's in the middle + + + align:start position:0% +try to see a bit what's in the middle +what is the set of techniques that + + align:start position:0% +what is the set of techniques that + + + align:start position:0% +what is the set of techniques that +allows you indeed to go from data to + + align:start position:0% +allows you indeed to go from data to + + + align:start position:0% +allows you indeed to go from data to +knowledge or to acquiring ability to + + align:start position:0% +knowledge or to acquiring ability to + + + align:start position:0% +knowledge or to acquiring ability to +solve tasks machine learning is used + + align:start position:0% +solve tasks machine learning is used + + + align:start position:0% +solve tasks machine learning is used +these days and there are tons of + + align:start position:0% +these days and there are tons of + + + align:start position:0% +these days and there are tons of +possible application there has been + + align:start position:0% +possible application there has been + + + align:start position:0% +possible application there has been +Theory developed in the last 20-30 years + + align:start position:0% +Theory developed in the last 20-30 years + + + align:start position:0% +Theory developed in the last 20-30 years +that brought the field to a certain + + align:start position:0% +that brought the field to a certain + + + align:start position:0% +that brought the field to a certain +level of maturity from a mathematical + + align:start position:0% +level of maturity from a mathematical + + + align:start position:0% +level of maturity from a mathematical +point of view they're having tons and + + align:start position:0% +point of view they're having tons and + + + align:start position:0% +point of view they're having tons and +tons and tons of algorithms developed ok + + align:start position:0% +tons and tons of algorithms developed ok + + + align:start position:0% +tons and tons of algorithms developed ok +so in three hours there's no way I could + + align:start position:0% +so in three hours there's no way I could + + + align:start position:0% +so in three hours there's no way I could +give you an even just little view of + + align:start position:0% +give you an even just little view of + + + align:start position:0% +give you an even just little view of +what machine learning is these days so + + align:start position:0% +what machine learning is these days so + + + align:start position:0% +what machine learning is these days so +what I did is pretty much this so now + + align:start position:0% +what I did is pretty much this so now + + + align:start position:0% +what I did is pretty much this so now +when you do it I don't know if you ever + + align:start position:0% +when you do it I don't know if you ever + + + align:start position:0% +when you do it I don't know if you ever +done this but you know used a mixtape + + align:start position:0% +done this but you know used a mixtape + + + align:start position:0% +done this but you know used a mixtape +and you try to pick the songs that you + + align:start position:0% +and you try to pick the songs that you + + + align:start position:0% +and you try to pick the songs that you +would bring with yourself on a desert + + align:start position:0% +would bring with yourself on a desert + + + align:start position:0% +would bring with yourself on a desert +island that's kind of the way I thought + + align:start position:0% +island that's kind of the way I thought + + + align:start position:0% +island that's kind of the way I thought +about what to put in this cookie in this + + align:start position:0% +about what to put in this cookie in this + + + align:start position:0% +about what to put in this cookie in this +one feels little life that you're going + + align:start position:0% +one feels little life that you're going + + + align:start position:0% +one feels little life that you're going +to show in a minute so basically I + + align:start position:0% +to show in a minute so basically I + + + align:start position:0% +to show in a minute so basically I +thought you know what what are those + + align:start position:0% +thought you know what what are those + + + align:start position:0% +thought you know what what are those +three four five learning algorithm that + + align:start position:0% +three four five learning algorithm that + + + align:start position:0% +three four five learning algorithm that +you should know okay if you know nothing + + align:start position:0% +you should know okay if you know nothing + + + align:start position:0% +you should know okay if you know nothing +about machine learning and this is more + + align:start position:0% +about machine learning and this is more + + + align:start position:0% +about machine learning and this is more +or less at least one part of course + + align:start position:0% +or less at least one part of course + + + align:start position:0% +or less at least one part of course +there are few songs that stayed out of + + align:start position:0% +there are few songs that stayed out of + + + align:start position:0% +there are few songs that stayed out of +the compilation but this is like one + + align:start position:0% +the compilation but this is like one + + + align:start position:0% +the compilation but this is like one +selection okay so we're gonna such we're + + align:start position:0% +selection okay so we're gonna such we're + + + align:start position:0% +selection okay so we're gonna such we're +gonna start as I said simple and the + + align:start position:0% +gonna start as I said simple and the + + + align:start position:0% +gonna start as I said simple and the +idea is that this morning you're gonna + + align:start position:0% +idea is that this morning you're gonna + + + align:start position:0% +idea is that this morning you're gonna +see a few algorithms and we're gonna I + + align:start position:0% +see a few algorithms and we're gonna I + + + align:start position:0% +see a few algorithms and we're gonna I +picked algorithm that are relatively + + align:start position:0% +picked algorithm that are relatively + + + align:start position:0% +picked algorithm that are relatively +simple from a computational point of + + align:start position:0% +simple from a computational point of + + + align:start position:0% +simple from a computational point of +view so the math level is gonna be + + align:start position:0% +view so the math level is gonna be + + + align:start position:0% +view so the math level is gonna be +pretty basic okay I think I'm gonna use + + align:start position:0% +pretty basic okay I think I'm gonna use + + + align:start position:0% +pretty basic okay I think I'm gonna use +some linear algebra at some point and + + align:start position:0% +some linear algebra at some point and + + + align:start position:0% +some linear algebra at some point and +maybe some calculus but that's about it + + align:start position:0% +maybe some calculus but that's about it + + + align:start position:0% +maybe some calculus but that's about it +so mostly the idea here is to emphasize + + align:start position:0% +so mostly the idea here is to emphasize + + + align:start position:0% +so mostly the idea here is to emphasize +conceptual ideas okay the concepts and + + align:start position:0% +conceptual ideas okay the concepts and + + + align:start position:0% +conceptual ideas okay the concepts and +then today afternoon there's gonna be + + align:start position:0% +then today afternoon there's gonna be + + + align:start position:0% +then today afternoon there's gonna be +basically labs where you sit and you + + align:start position:0% +basically labs where you sit and you + + + align:start position:0% +basically labs where you sit and you +just pick this kind of algorithm and use + + align:start position:0% +just pick this kind of algorithm and use + + + align:start position:0% +just pick this kind of algorithm and use +them so you immediately see what does it + + align:start position:0% +them so you immediately see what does it + + + align:start position:0% +them so you immediately see what does it +mean okay so at the end of the day you + + align:start position:0% +mean okay so at the end of the day you + + + align:start position:0% +mean okay so at the end of the day you +should have a reasonable knowledge about + + align:start position:0% +should have a reasonable knowledge about + + + align:start position:0% +should have a reasonable knowledge about +whatever you've seen this morning so + + align:start position:0% +whatever you've seen this morning so + + + align:start position:0% +whatever you've seen this morning so +this is how the class is structured it's + + align:start position:0% +this is how the class is structured it's + + + align:start position:0% +this is how the class is structured it's +dividing three parts plus the lab + + align:start position:0% +dividing three parts plus the lab + + + align:start position:0% +dividing three parts plus the lab +so in the first part what we want to do + + align:start position:0% +so in the first part what we want to do + + + align:start position:0% +so in the first part what we want to do +is start from the probably the simplest + + align:start position:0% +is start from the probably the simplest + + + align:start position:0% +is start from the probably the simplest +learning algorithm you can think of to + + align:start position:0% +learning algorithm you can think of to + + + align:start position:0% +learning algorithm you can think of to +try to emphasize and use that as an + + align:start position:0% +try to emphasize and use that as an + + + align:start position:0% +try to emphasize and use that as an +excuse to introduce the idea of + + align:start position:0% +excuse to introduce the idea of + + + align:start position:0% +excuse to introduce the idea of +bias-variance tradeoff which to me is + + align:start position:0% +bias-variance tradeoff which to me is + + + align:start position:0% +bias-variance tradeoff which to me is +probably either the or one of the most + + align:start position:0% +probably either the or one of the most + + + align:start position:0% +probably either the or one of the most +fundamental concept in statistics and + + align:start position:0% +fundamental concept in statistics and + + + align:start position:0% +fundamental concept in statistics and +machine learning which is this idea that + + align:start position:0% +machine learning which is this idea that + + + align:start position:0% +machine learning which is this idea that +you're gonna see in a few minutes in + + align:start position:0% +you're gonna see in a few minutes in + + + align:start position:0% +you're gonna see in a few minutes in +more detail but it's essentially that is + + align:start position:0% +more detail but it's essentially that is + + + align:start position:0% +more detail but it's essentially that is +that you never have enough data okay and + + align:start position:0% +that you never have enough data okay and + + + align:start position:0% +that you never have enough data okay and +the game here is not about describing + + align:start position:0% +the game here is not about describing + + + align:start position:0% +the game here is not about describing +the data that you have today as much as + + align:start position:0% +the data that you have today as much as + + + align:start position:0% +the data that you have today as much as +using the data you have today as the + + align:start position:0% +using the data you have today as the + + + align:start position:0% +using the data you have today as the +basis of a knowledge to distract it that + + align:start position:0% +basis of a knowledge to distract it that + + + align:start position:0% +basis of a knowledge to distract it that +you're gonna get tomorrow so there is + + align:start position:0% +you're gonna get tomorrow so there is + + + align:start position:0% +you're gonna get tomorrow so there is +this Niren trade-off between what you + + align:start position:0% +this Niren trade-off between what you + + + align:start position:0% +this Niren trade-off between what you +have a disposal and what would you like + + align:start position:0% +have a disposal and what would you like + + + align:start position:0% +have a disposal and what would you like +to predict and then you have to + + align:start position:0% +to predict and then you have to + + + align:start position:0% +to predict and then you have to +essentially turns out that you have to + + align:start position:0% +essentially turns out that you have to + + + align:start position:0% +essentially turns out that you have to +somewhat decide how much you want to + + align:start position:0% +somewhat decide how much you want to + + + align:start position:0% +somewhat decide how much you want to +trust the data and how much you want + + align:start position:0% +trust the data and how much you want + + + align:start position:0% +trust the data and how much you want +instead somewhat throw away or you know + + align:start position:0% +instead somewhat throw away or you know + + + align:start position:0% +instead somewhat throw away or you know +regularize as they say smooth out the + + align:start position:0% +regularize as they say smooth out the + + + align:start position:0% +regularize as they say smooth out the +information in your data because you + + align:start position:0% +information in your data because you + + + align:start position:0% +information in your data because you +think that it's actually an accident is + + align:start position:0% +think that it's actually an accident is + + + align:start position:0% +think that it's actually an accident is +just because you're so data with aspects + + align:start position:0% +just because you're so data with aspects + + + align:start position:0% +just because you're so data with aspects +today they are not really reflective of + + align:start position:0% +today they are not really reflective of + + + align:start position:0% +today they are not really reflective of +the phenomenon they produce them but + + align:start position:0% +the phenomenon they produce them but + + + align:start position:0% +the phenomenon they produce them but +it's just because I saw 10 points rather + + align:start position:0% +it's just because I saw 10 points rather + + + align:start position:0% +it's just because I saw 10 points rather +than 100 the basic idea here is this + + align:start position:0% +than 100 the basic idea here is this + + + align:start position:0% +than 100 the basic idea here is this +essentially the law of large numbers or + + align:start position:0% +essentially the law of large numbers or + + + align:start position:0% +essentially the law of large numbers or +you know toss a coin you might find out + + align:start position:0% +you know toss a coin you might find out + + + align:start position:0% +you know toss a coin you might find out +that if it was it just ten times it + + align:start position:0% +that if it was it just ten times it + + + align:start position:0% +that if it was it just ten times it +looks like it's not the fair coin but if + + align:start position:0% +looks like it's not the fair coin but if + + + align:start position:0% +looks like it's not the fair coin but if +you go for a hundred or Taj and you + + align:start position:0% +you go for a hundred or Taj and you + + + align:start position:0% +you go for a hundred or Taj and you +start to see that it converts to 5050 + + align:start position:0% +start to see that it converts to 5050 + + + align:start position:0% +start to see that it converts to 5050 +okay so that's kind of what's going on + + align:start position:0% +okay so that's kind of what's going on + + + align:start position:0% +okay so that's kind of what's going on +here so the idea that you want to use + + align:start position:0% +here so the idea that you want to use + + + align:start position:0% +here so the idea that you want to use +some kind of induction principle that + + align:start position:0% +some kind of induction principle that + + + align:start position:0% +some kind of induction principle that +tells you how much you can trust the + + align:start position:0% +tells you how much you can trust the + + + align:start position:0% +tells you how much you can trust the +data moving on from this basic class of + + align:start position:0% +data moving on from this basic class of + + + align:start position:0% +data moving on from this basic class of +algorithm we're going to consider so + + align:start position:0% +algorithm we're going to consider so + + + align:start position:0% +algorithm we're going to consider so +called regularization techniques this is + + align:start position:0% +called regularization techniques this is + + + align:start position:0% +called regularization techniques this is +a very I use regularization a very broad + + align:start position:0% +a very I use regularization a very broad + + + align:start position:0% +a very I use regularization a very broad +sense and here we're gonna concentrate + + align:start position:0% +sense and here we're gonna concentrate + + + align:start position:0% +sense and here we're gonna concentrate +on lean least squares essentially + + align:start position:0% +on lean least squares essentially + + + align:start position:0% +on lean least squares essentially +because a it's simple and it just + + align:start position:0% +because a it's simple and it just + + + align:start position:0% +because a it's simple and it just +reduces to linear algebra and so you + + align:start position:0% +reduces to linear algebra and so you + + + align:start position:0% +reduces to linear algebra and so you +have no you don't have to know anything + + align:start position:0% +have no you don't have to know anything + + + align:start position:0% +have no you don't have to know anything +about convex optimization or any other + + align:start position:0% +about convex optimization or any other + + + align:start position:0% +about convex optimization or any other +kind of fancy optimization techniques + + align:start position:0% +kind of fancy optimization techniques + + + align:start position:0% +kind of fancy optimization techniques +and B because it's relatively simple to + + align:start position:0% +and B because it's relatively simple to + + + align:start position:0% +and B because it's relatively simple to +move from linear models to nonparametric + + align:start position:0% +move from linear models to nonparametric + + + align:start position:0% +move from linear models to nonparametric +nonlinear models using kernels okay and + + align:start position:0% +nonlinear models using kernels okay and + + + align:start position:0% +nonlinear models using kernels okay and +kernels are a big field but we you know + + align:start position:0% +kernels are a big field but we you know + + + align:start position:0% +kernels are a big field but we you know +with a lot of math but you're just gonna + + align:start position:0% +with a lot of math but you're just gonna + + + align:start position:0% +with a lot of math but you're just gonna +more at the recipe to move from simple + + align:start position:0% +more at the recipe to move from simple + + + align:start position:0% +more at the recipe to move from simple +models to complicated models so finally + + align:start position:0% +models to complicated models so finally + + + align:start position:0% +models to complicated models so finally +the last part we're going to move a bit + + align:start position:0% +the last part we're going to move a bit + + + align:start position:0% +the last part we're going to move a bit +away from pure prediction so the + + align:start position:0% +away from pure prediction so the + + + align:start position:0% +away from pure prediction so the +basically these first two parts are + + align:start position:0% +basically these first two parts are + + + align:start position:0% +basically these first two parts are +about prediction or what is called + + align:start position:0% +about prediction or what is called + + + align:start position:0% +about prediction or what is called +supervised learning and here we're going + + align:start position:0% +supervised learning and here we're going + + + align:start position:0% +supervised learning and here we're going +to move a bit away from prediction and + + align:start position:0% +to move a bit away from prediction and + + + align:start position:0% +to move a bit away from prediction and +we're going to ask question more related + + align:start position:0% +we're going to ask question more related + + + align:start position:0% +we're going to ask question more related +to you have data and you want to know + + align:start position:0% +to you have data and you want to know + + + align:start position:0% +to you have data and you want to know +what are the important sectors in your + + align:start position:0% +what are the important sectors in your + + + align:start position:0% +what are the important sectors in your +data + + align:start position:0% +data + + + align:start position:0% +data +okay so you've the one key word here is + + align:start position:0% +okay so you've the one key word here is + + + align:start position:0% +okay so you've the one key word here is +the interpretability you want to have + + align:start position:0% +the interpretability you want to have + + + align:start position:0% +the interpretability you want to have +some form of interpret ability of the + + align:start position:0% +some form of interpret ability of the + + + align:start position:0% +some form of interpret ability of the +data at hand you would like to know not + + align:start position:0% +data at hand you would like to know not + + + align:start position:0% +data at hand you would like to know not +only how you can make good predictions + + align:start position:0% +only how you can make good predictions + + + align:start position:0% +only how you can make good predictions +but what are the important sectors so + + align:start position:0% +but what are the important sectors so + + + align:start position:0% +but what are the important sectors so +you not only want to do good prediction + + align:start position:0% +you not only want to do good prediction + + + align:start position:0% +you not only want to do good prediction +but you want to know how you make good + + align:start position:0% +but you want to know how you make good + + + align:start position:0% +but you want to know how you make good +prediction what are the important + + align:start position:0% +prediction what are the important + + + align:start position:0% +prediction what are the important +information to actually get good + + align:start position:0% +information to actually get good + + + align:start position:0% +information to actually get good +prediction and so in this last part + + align:start position:0% +prediction and so in this last part + + + align:start position:0% +prediction and so in this last part +we're gonna take a peek into this and as + + align:start position:0% +we're gonna take a peek into this and as + + + align:start position:0% +we're gonna take a peek into this and as +I said the afternoon is basically going + + align:start position:0% +I said the afternoon is basically going + + + align:start position:0% +I said the afternoon is basically going +to be practical session if it's all + + align:start position:0% +to be practical session if it's all + + + align:start position:0% +to be practical session if it's all +MATLAB I think there is some quick if + + align:start position:0% +MATLAB I think there is some quick if + + + align:start position:0% +MATLAB I think there is some quick if +you've never seen MATLAB before you can + + align:start position:0% +you've never seen MATLAB before you can + + + align:start position:0% +you've never seen MATLAB before you can +play around with a little bit just a + + align:start position:0% +play around with a little bit just a + + + align:start position:0% +play around with a little bit just a +little bit but it's very easy and then + + align:start position:0% +little bit but it's very easy and then + + + align:start position:0% +little bit but it's very easy and then +you've got a few different proposals I + + align:start position:0% +you've got a few different proposals I + + + align:start position:0% +you've got a few different proposals I +think of things you can do and you can + + align:start position:0% +think of things you can do and you can + + + align:start position:0% +think of things you can do and you can +pick depending on what you already know + + align:start position:0% +pick depending on what you already know + + + align:start position:0% +pick depending on what you already know +what you can try you can start from that + + align:start position:0% +what you can try you can start from that + + + align:start position:0% +what you can try you can start from that +and be more or less fancy okay so those + + align:start position:0% +and be more or less fancy okay so those + + + align:start position:0% +and be more or less fancy okay so those +without saying stop me it's the more we + + align:start position:0% +without saying stop me it's the more we + + + align:start position:0% +without saying stop me it's the more we +interact the better it is so the first + + align:start position:0% +interact the better it is so the first + + + align:start position:0% +interact the better it is so the first +part is I said the idea is to use + + align:start position:0% +part is I said the idea is to use + + + align:start position:0% +part is I said the idea is to use +so-called local methods as an excuse to + + align:start position:0% +so-called local methods as an excuse to + + + align:start position:0% +so-called local methods as an excuse to +understand by experience ok so we're + + align:start position:0% +understand by experience ok so we're + + + align:start position:0% +understand by experience ok so we're +going to introduce the simplest + + align:start position:0% +going to introduce the simplest + + + align:start position:0% +going to introduce the simplest +algorithm you can think of and we're + + align:start position:0% +algorithm you can think of and we're + + + align:start position:0% +algorithm you can think of and we're +gonna use it to understand a much deeper + + align:start position:0% +gonna use it to understand a much deeper + + + align:start position:0% +gonna use it to understand a much deeper +concept so first of all let's just put + + align:start position:0% +concept so first of all let's just put + + + align:start position:0% +concept so first of all let's just put +our set up ok put down our set up the + + align:start position:0% +our set up ok put down our set up the + + + align:start position:0% +our set up ok put down our set up the +idea is that we're so how many of you + + align:start position:0% +idea is that we're so how many of you + + + align:start position:0% +idea is that we're so how many of you +had a machine learning cost before + + align:start position:0% +had a machine learning cost before + + + align:start position:0% +had a machine learning cost before +alright so don't be too bored the idea + + align:start position:0% +alright so don't be too bored the idea + + + align:start position:0% +alright so don't be too bored the idea +is - we want to do supervised learning + + align:start position:0% +is - we want to do supervised learning + + + align:start position:0% +is - we want to do supervised learning +so in supervised learning there is an + + align:start position:0% +so in supervised learning there is an + + + align:start position:0% +so in supervised learning there is an +input and an output and these input and + + align:start position:0% +input and an output and these input and + + + align:start position:0% +input and an output and these input and +output are somewhat related and I'll be + + align:start position:0% +output are somewhat related and I'll be + + + align:start position:0% +output are somewhat related and I'll be +more precise efficient but the idea is + + align:start position:0% +more precise efficient but the idea is + + + align:start position:0% +more precise efficient but the idea is +that you want to learn this input-output + + align:start position:0% +that you want to learn this input-output + + + align:start position:0% +that you want to learn this input-output +relationship and all you have at + + align:start position:0% +relationship and all you have at + + + align:start position:0% +relationship and all you have at +disposal are sets of inputs and outputs + + align:start position:0% +disposal are sets of inputs and outputs + + + align:start position:0% +disposal are sets of inputs and outputs +ok so X here is an input and Y is the + + align:start position:0% +ok so X here is an input and Y is the + + + align:start position:0% +ok so X here is an input and Y is the +out + + align:start position:0% +out + + + align:start position:0% +out +F is a functional relation between the + + align:start position:0% +F is a functional relation between the + + + align:start position:0% +F is a functional relation between the +input and the output all you have this + + align:start position:0% +input and the output all you have this + + + align:start position:0% +input and the output all you have this +puzzle are these couples okay so I give + + align:start position:0% +puzzle are these couples okay so I give + + + align:start position:0% +puzzle are these couples okay so I give +you an input and I know what's the + + align:start position:0% +you an input and I know what's the + + + align:start position:0% +you an input and I know what's the +corresponding output I give another + + align:start position:0% +corresponding output I give another + + + align:start position:0% +corresponding output I give another +input and I know what's the + + align:start position:0% +input and I know what's the + + + align:start position:0% +input and I know what's the +corresponding output but they don't give + + align:start position:0% +corresponding output but they don't give + + + align:start position:0% +corresponding output but they don't give +you all of them + + align:start position:0% +you all of them + + + align:start position:0% +you all of them +you just have n okay is n is the number + + align:start position:0% +you just have n okay is n is the number + + + align:start position:0% +you just have n okay is n is the number +of points and you call this a training + + align:start position:0% +of points and you call this a training + + + align:start position:0% +of points and you call this a training +set because there will be the basis of + + align:start position:0% +set because there will be the basis of + + + align:start position:0% +set because there will be the basis of +knowledge in which you can try to train + + align:start position:0% +knowledge in which you can try to train + + + align:start position:0% +knowledge in which you can try to train +a machine to estimate this functional + + align:start position:0% +a machine to estimate this functional + + + align:start position:0% +a machine to estimate this functional +relationship okay and the key point here + + align:start position:0% +relationship okay and the key point here + + + align:start position:0% +relationship okay and the key point here +is that on the one hand you want to + + align:start position:0% +is that on the one hand you want to + + + align:start position:0% +is that on the one hand you want to +describe well this data so you want to + + align:start position:0% +describe well this data so you want to + + + align:start position:0% +describe well this data so you want to +get a function relationship that works + + align:start position:0% +get a function relationship that works + + + align:start position:0% +get a function relationship that works +well in you know if you get the next one + + align:start position:0% +well in you know if you get the next one + + + align:start position:0% +well in you know if you get the next one +to give you an F x1 which is close to y1 + + align:start position:0% +to give you an F x1 which is close to y1 + + + align:start position:0% +to give you an F x1 which is close to y1 +and so on and F x2 which is close to y2 + + align:start position:0% +and so on and F x2 which is close to y2 + + + align:start position:0% +and so on and F x2 which is close to y2 +but more importantly you want an F that + + align:start position:0% +but more importantly you want an F that + + + align:start position:0% +but more importantly you want an F that +given a new point that was not here will + + align:start position:0% +given a new point that was not here will + + + align:start position:0% +given a new point that was not here will +give you an output which is a good + + align:start position:0% +give you an output which is a good + + + align:start position:0% +give you an output which is a good +estimate of the true output to respond + + align:start position:0% +estimate of the true output to respond + + + align:start position:0% +estimate of the true output to respond +to that input okay this is the the most + + align:start position:0% +to that input okay this is the the most + + + align:start position:0% +to that input okay this is the the most +important thing of the set up okay the + + align:start position:0% +important thing of the set up okay the + + + align:start position:0% +important thing of the set up okay the +idea of so called generalization if you + + align:start position:0% +idea of so called generalization if you + + + align:start position:0% +idea of so called generalization if you +want prediction you want to really do + + align:start position:0% +want prediction you want to really do + + + align:start position:0% +want prediction you want to really do +inference you don't want to do + + align:start position:0% +inference you don't want to do + + + align:start position:0% +inference you don't want to do +descriptive statistics you really want + + align:start position:0% +descriptive statistics you really want + + + align:start position:0% +descriptive statistics you really want +to do inferential statistics so this is + + align:start position:0% +to do inferential statistics so this is + + + align:start position:0% +to do inferential statistics so this is +just a very very simple example but just + + align:start position:0% +just a very very simple example but just + + + align:start position:0% +just a very very simple example but just +to start to have something in mind + + align:start position:0% +to start to have something in mind + + + align:start position:0% +to start to have something in mind +suppose that you have well the it it's + + align:start position:0% +suppose that you have well the it it's + + + align:start position:0% +suppose that you have well the it it's +just a like a toy version of the face + + align:start position:0% +just a like a toy version of the face + + + align:start position:0% +just a like a toy version of the face +recognition system we have on our phones + + align:start position:0% +recognition system we have on our phones + + + align:start position:0% +recognition system we have on our phones +you know that when you take a picture + + align:start position:0% +you know that when you take a picture + + + align:start position:0% +you know that when you take a picture +you start they really want to talk to + + align:start position:0% +you start they really want to talk to + + + align:start position:0% +you start they really want to talk to +you you you have something like these + + align:start position:0% +you you you have something like these + + + align:start position:0% +you you you have something like these +you have a legal square appearing around + + align:start position:0% +you have a legal square appearing around + + + align:start position:0% +you have a legal square appearing around +a face sometimes it means that basically + + align:start position:0% +a face sometimes it means that basically + + + align:start position:0% +a face sometimes it means that basically +the system is actually going inside the + + align:start position:0% +the system is actually going inside the + + + align:start position:0% +the system is actually going inside the +image and recognizing faces okay so the + + align:start position:0% +image and recognizing faces okay so the + + + align:start position:0% +image and recognizing faces okay so the +idea is that it's a bit more complicated + + align:start position:0% +idea is that it's a bit more complicated + + + align:start position:0% +idea is that it's a bit more complicated +in this but a toy version of this + + align:start position:0% +in this but a toy version of this + + + align:start position:0% +in this but a toy version of this +algorithm is you have an image like this + + align:start position:0% +algorithm is you have an image like this + + + align:start position:0% +algorithm is you have an image like this +okay the image you can think of as an + + align:start position:0% +okay the image you can think of as an + + + align:start position:0% +okay the image you can think of as an +hour like matrix of numbers each number + + align:start position:0% +hour like matrix of numbers each number + + + align:start position:0% +hour like matrix of numbers each number +is going now this is just this is color + + align:start position:0% +is going now this is just this is color + + + align:start position:0% +is going now this is just this is color +but imagine it's black and white okay + + align:start position:0% +but imagine it's black and white okay + + + align:start position:0% +but imagine it's black and white okay +then it will just contain a number which + + align:start position:0% +then it will just contain a number which + + + align:start position:0% +then it will just contain a number which +is the pixel value with the color with + + align:start position:0% +is the pixel value with the color with + + + align:start position:0% +is the pixel value with the color with +the light intensity of that pixel and it + + align:start position:0% +the light intensity of that pixel and it + + + align:start position:0% +the light intensity of that pixel and it +does that these array + + align:start position:0% +does that these array + + + align:start position:0% +does that these array +and then if you want you can brutalize + + align:start position:0% +and then if you want you can brutalize + + + align:start position:0% +and then if you want you can brutalize +it with this and just unroll the matrix + + align:start position:0% +it with this and just unroll the matrix + + + align:start position:0% +it with this and just unroll the matrix +into a long vector okay let's take this + + align:start position:0% +into a long vector okay let's take this + + + align:start position:0% +into a long vector okay let's take this +one vector so P here would be what the + + align:start position:0% +one vector so P here would be what the + + + align:start position:0% +one vector so P here would be what the +number of just a number of pixels okay + + align:start position:0% +number of just a number of pixels okay + + + align:start position:0% +number of just a number of pixels okay +so I take this image and I unroll it I + + align:start position:0% +so I take this image and I unroll it I + + + align:start position:0% +so I take this image and I unroll it I +take another image and I unroll it and I + + align:start position:0% +take another image and I unroll it and I + + + align:start position:0% +take another image and I unroll it and I +take images and you see some images here + + align:start position:0% +take images and you see some images here + + + align:start position:0% +take images and you see some images here +do contain faces some other images do + + align:start position:0% +do contain faces some other images do + + + align:start position:0% +do contain faces some other images do +not contain faces okay and I here use + + align:start position:0% +not contain faces okay and I here use + + + align:start position:0% +not contain faces okay and I here use +color to code them and now what I have + + align:start position:0% +color to code them and now what I have + + + align:start position:0% +color to code them and now what I have +is that images are my input okay are the + + align:start position:0% +is that images are my input okay are the + + + align:start position:0% +is that images are my input okay are the +X's so here full disclosure I sometimes + + align:start position:0% +X's so here full disclosure I sometimes + + + align:start position:0% +X's so here full disclosure I sometimes +I don't I never use the little arrow + + align:start position:0% +I don't I never use the little arrow + + + align:start position:0% +I don't I never use the little arrow +above letters to denote vectors so + + align:start position:0% +above letters to denote vectors so + + + align:start position:0% +above letters to denote vectors so +hopefully will be clear from the context + + align:start position:0% +hopefully will be clear from the context + + + align:start position:0% +hopefully will be clear from the context +when it's really useful I use like upper + + align:start position:0% +when it's really useful I use like upper + + + align:start position:0% +when it's really useful I use like upper +or lower indices anyway so this is the + + align:start position:0% +or lower indices anyway so this is the + + + align:start position:0% +or lower indices anyway so this is the +data matrix rows are inputs and columns + + align:start position:0% +data matrix rows are inputs and columns + + + align:start position:0% +data matrix rows are inputs and columns +are so-called features or variables are + + align:start position:0% +are so-called features or variables are + + + align:start position:0% +are so-called features or variables are +the entries of each vector okay and I + + align:start position:0% +the entries of each vector okay and I + + + align:start position:0% +the entries of each vector okay and I +have n rows and P columns associated to + + align:start position:0% +have n rows and P columns associated to + + + align:start position:0% +have n rows and P columns associated to +this I have my output vector and what is + + align:start position:0% +this I have my output vector and what is + + + align:start position:0% +this I have my output vector and what is +the output vector well in this case it + + align:start position:0% +the output vector well in this case it + + + align:start position:0% +the output vector well in this case it +is just a simple binary vector and the + + align:start position:0% +is just a simple binary vector and the + + + align:start position:0% +is just a simple binary vector and the +idea here is if there is a face I put + + align:start position:0% +idea here is if there is a face I put + + + align:start position:0% +idea here is if there is a face I put +one if there is not a face I put minus + + align:start position:0% +one if there is not a face I put minus + + + align:start position:0% +one if there is not a face I put minus +one okay so this is the way I turn like + + align:start position:0% +one okay so this is the way I turn like + + + align:start position:0% +one okay so this is the way I turn like +an abstract question recognize faces in + + align:start position:0% +an abstract question recognize faces in + + + align:start position:0% +an abstract question recognize faces in +images into some data structure that in + + align:start position:0% +images into some data structure that in + + + align:start position:0% +images into some data structure that in +a minute we're going to elaborate to try + + align:start position:0% +a minute we're going to elaborate to try + + + align:start position:0% +a minute we're going to elaborate to try +to actually answer the question whether + + align:start position:0% +to actually answer the question whether + + + align:start position:0% +to actually answer the question whether +there is a face in an image or not okay + + align:start position:0% +there is a face in an image or not okay + + + align:start position:0% +there is a face in an image or not okay +so this first step it's kind of obvious + + align:start position:0% +so this first step it's kind of obvious + + + align:start position:0% +so this first step it's kind of obvious +in this case but it's actually a tricky + + align:start position:0% +in this case but it's actually a tricky + + + align:start position:0% +in this case but it's actually a tricky +step okay is the part where I'm not that + + align:start position:0% +step okay is the part where I'm not that + + + align:start position:0% +step okay is the part where I'm not that +I'm not gonna give you any hint about + + align:start position:0% +I'm not gonna give you any hint about + + + align:start position:0% +I'm not gonna give you any hint about +it's kind of an art you have data and + + align:start position:0% +it's kind of an art you have data and + + + align:start position:0% +it's kind of an art you have data and +you have at the very beginning you have + + align:start position:0% +you have at the very beginning you have + + + align:start position:0% +you have at the very beginning you have +to turn them into some kind of + + align:start position:0% +to turn them into some kind of + + + align:start position:0% +to turn them into some kind of +manageable data structure okay then you + + align:start position:0% +manageable data structure okay then you + + + align:start position:0% +manageable data structure okay then you +can elaborate in multiple ways but the + + align:start position:0% +can elaborate in multiple ways but the + + + align:start position:0% +can elaborate in multiple ways but the +very first step is you deciding for + + align:start position:0% +very first step is you deciding for + + + align:start position:0% +very first step is you deciding for +example here we decided to unroll all + + align:start position:0% +example here we decided to unroll all + + + align:start position:0% +example here we decided to unroll all +these number into vectors this sounds + + align:start position:0% +these number into vectors this sounds + + + align:start position:0% +these number into vectors this sounds +like a good idea or a bad idea + + align:start position:0% +like a good idea or a bad idea + + + align:start position:0% +like a good idea or a bad idea +one thing that you're doing is that the + + align:start position:0% +one thing that you're doing is that the + + + align:start position:0% +one thing that you're doing is that the +pixel here and the pixel here are + + align:start position:0% +pixel here and the pixel here are + + + align:start position:0% +pixel here and the pixel here are +probably related right and in this case + + align:start position:0% +probably related right and in this case + + + align:start position:0% +probably related right and in this case +there are some structure in the image + + align:start position:0% +there are some structure in the image + + + align:start position:0% +there are some structure in the image +and so when you take the expected one + + align:start position:0% +and so when you take the expected one + + + align:start position:0% +and so when you take the expected one +three six and you unroll it it comes + + align:start position:0% +three six and you unroll it it comes + + + align:start position:0% +three six and you unroll it it comes +here so they're not close okay now here + + align:start position:0% +here so they're not close okay now here + + + align:start position:0% +here so they're not close okay now here +it turns out that if you think about it + + align:start position:0% +it turns out that if you think about it + + + align:start position:0% +it turns out that if you think about it +you'll see in a minute for those of you + + align:start position:0% +you'll see in a minute for those of you + + + align:start position:0% +you'll see in a minute for those of you +remember if you just took Euclidean + + align:start position:0% +remember if you just took Euclidean + + + align:start position:0% +remember if you just took Euclidean +distance you take product of numbers and + + align:start position:0% +distance you take product of numbers and + + + align:start position:0% +distance you take product of numbers and +you sum them up that's invariant to the + + align:start position:0% +you sum them up that's invariant to the + + + align:start position:0% +you sum them up that's invariant to the +position of the individual pixels so + + align:start position:0% +position of the individual pixels so + + + align:start position:0% +position of the individual pixels so +that's okay okay but yet again there is + + align:start position:0% +that's okay okay but yet again there is + + + align:start position:0% +that's okay okay but yet again there is +this intuition that well maybe here I'm + + align:start position:0% +this intuition that well maybe here I'm + + + align:start position:0% +this intuition that well maybe here I'm +losing too much geometric information + + align:start position:0% +losing too much geometric information + + + align:start position:0% +losing too much geometric information +about the contact of the image and + + align:start position:0% +about the contact of the image and + + + align:start position:0% +about the contact of the image and +indeed well this kind of work in + + align:start position:0% +indeed well this kind of work in + + + align:start position:0% +indeed well this kind of work in +practice but if you want to get better + + align:start position:0% +practice but if you want to get better + + + align:start position:0% +practice but if you want to get better +results you have to do the fancy stuff + + align:start position:0% +results you have to do the fancy stuff + + + align:start position:0% +results you have to do the fancy stuff +that Andrei was talking about today + + align:start position:0% +that Andrei was talking about today + + + align:start position:0% +that Andrei was talking about today +looking locally and try to look a + + align:start position:0% +looking locally and try to look a + + + align:start position:0% +looking locally and try to look a +collection try to keep more geometric + + align:start position:0% +collection try to keep more geometric + + + align:start position:0% +collection try to keep more geometric +information okay so I'm not going to + + align:start position:0% +information okay so I'm not going to + + + align:start position:0% +information okay so I'm not going to +talk about that kind of stuff this up + + align:start position:0% +talk about that kind of stuff this up + + + align:start position:0% +talk about that kind of stuff this up +today it's a lot of engineering and some + + align:start position:0% +today it's a lot of engineering and some + + + align:start position:0% +today it's a lot of engineering and some +good way to learn it but we're gonna try + + align:start position:0% +good way to learn it but we're gonna try + + + align:start position:0% +good way to learn it but we're gonna try +to just stick to simple representations + + align:start position:0% +to just stick to simple representations + + + align:start position:0% +to just stick to simple representations +okay so how do you build representation + + align:start position:0% +okay so how do you build representation + + + align:start position:0% +okay so how do you build representation +is now gonna be part of the what I'm + + align:start position:0% +is now gonna be part of the what I'm + + + align:start position:0% +is now gonna be part of the what I'm +gonna talk about so imagine that either + + align:start position:0% +gonna talk about so imagine that either + + + align:start position:0% +gonna talk about so imagine that either +you stick to this super simple + + align:start position:0% +you stick to this super simple + + + align:start position:0% +you stick to this super simple +representation or some friends of yours + + align:start position:0% +representation or some friends of yours + + + align:start position:0% +representation or some friends of yours +come in and put a box here in the middle + + align:start position:0% +come in and put a box here in the middle + + + align:start position:0% +come in and put a box here in the middle +where you put this array of numbers and + + align:start position:0% +where you put this array of numbers and + + + align:start position:0% +where you put this array of numbers and +you extract another vector much fancier + + align:start position:0% +you extract another vector much fancier + + + align:start position:0% +you extract another vector much fancier +than this that contains some better + + align:start position:0% +than this that contains some better + + + align:start position:0% +than this that contains some better +representation of an image okay but then + + align:start position:0% +representation of an image okay but then + + + align:start position:0% +representation of an image okay but then +in the end of the day my job starts when + + align:start position:0% +in the end of the day my job starts when + + + align:start position:0% +in the end of the day my job starts when +you give me a vector representation that + + align:start position:0% +you give me a vector representation that + + + align:start position:0% +you give me a vector representation that +I can trust and I can basically say that + + align:start position:0% +I can trust and I can basically say that + + + align:start position:0% +I can trust and I can basically say that +if two vectors seems similar they should + + align:start position:0% +if two vectors seems similar they should + + + align:start position:0% +if two vectors seems similar they should +have the same label and that's the basic + + align:start position:0% +have the same label and that's the basic + + + align:start position:0% +have the same label and that's the basic +idea okay all right so the little game + + align:start position:0% +idea okay all right so the little game + + + align:start position:0% +idea okay all right so the little game +here is okay imagine that these are just + + align:start position:0% +here is okay imagine that these are just + + + align:start position:0% +here is okay imagine that these are just +the two pixel version of the images I + + align:start position:0% +the two pixel version of the images I + + + align:start position:0% +the two pixel version of the images I +show you before you have some boxes some + + align:start position:0% +show you before you have some boxes some + + + align:start position:0% +show you before you have some boxes some +some circles and then I give you this + + align:start position:0% +some circles and then I give you this + + + align:start position:0% +some circles and then I give you this +one triangle very original and very show + + align:start position:0% +one triangle very original and very show + + + align:start position:0% +one triangle very original and very show +you this yesterday and the question is + + align:start position:0% +you this yesterday and the question is + + + align:start position:0% +you this yesterday and the question is +what's the color of that okay and unless + + align:start position:0% +what's the color of that okay and unless + + + align:start position:0% +what's the color of that okay and unless +you are you haven't slept a minute + + align:start position:0% +you are you haven't slept a minute + + + align:start position:0% +you are you haven't slept a minute +you're gonna say it's orange but the + + align:start position:0% +you're gonna say it's orange but the + + + align:start position:0% +you're gonna say it's orange but the +question is how do you why you think + + align:start position:0% +question is how do you why you think + + + align:start position:0% +question is how do you why you think +it's orange + + align:start position:0% + + + + align:start position:0% + +sorry on it surrounded by oranges okay + + align:start position:0% +sorry on it surrounded by oranges okay + + + align:start position:0% +sorry on it surrounded by oranges okay +and she said it's close to oranges so it + + align:start position:0% +and she said it's close to oranges so it + + + align:start position:0% +and she said it's close to oranges so it +turns out that this is actually the + + align:start position:0% +turns out that this is actually the + + + align:start position:0% +turns out that this is actually the +simplest algorithm you can think of okay + + align:start position:0% +simplest algorithm you can think of okay + + + align:start position:0% +simplest algorithm you can think of okay +you check who you have close to you and + + align:start position:0% +you check who you have close to you and + + + align:start position:0% +you check who you have close to you and +if it's orange you say orange and if + + align:start position:0% +if it's orange you say orange and if + + + align:start position:0% +if it's orange you say orange and if +it's blue you say blue okay but we + + align:start position:0% +it's blue you say blue okay but we + + + align:start position:0% +it's blue you say blue okay but we +already made an assumption here which + + align:start position:0% +already made an assumption here which + + + align:start position:0% +already made an assumption here which +was green question which is that nearby + + align:start position:0% +was green question which is that nearby + + + align:start position:0% +was green question which is that nearby +things so we are basically saying that + + align:start position:0% +things so we are basically saying that + + + align:start position:0% +things so we are basically saying that +our victorial representation is such + + align:start position:0% +our victorial representation is such + + + align:start position:0% +our victorial representation is such +that if two things are close so I do + + align:start position:0% +that if two things are close so I do + + + align:start position:0% +that if two things are close so I do +have a distance and if two things are + + align:start position:0% +have a distance and if two things are + + + align:start position:0% +have a distance and if two things are +close then they might have the same + + align:start position:0% +close then they might have the same + + + align:start position:0% +close then they might have the same +semantic content okay which might be + + align:start position:0% +semantic content okay which might be + + + align:start position:0% +semantic content okay which might be +true or not for example if you take this + + align:start position:0% +true or not for example if you take this + + + align:start position:0% +true or not for example if you take this +inter you know this thing I show you + + align:start position:0% +inter you know this thing I show you + + + align:start position:0% +inter you know this thing I show you +here well we cannot just draw it right + + align:start position:0% +here well we cannot just draw it right + + + align:start position:0% +here well we cannot just draw it right +we cannot just take you know 200 times + + align:start position:0% +we cannot just take you know 200 times + + + align:start position:0% +we cannot just take you know 200 times +200 vectors and just look at them and + + align:start position:0% +200 vectors and just look at them and + + + align:start position:0% +200 vectors and just look at them and +say you know visual inspection you have + + align:start position:0% +say you know visual inspection you have + + + align:start position:0% +say you know visual inspection you have +to believe that this distance will be + + align:start position:0% +to believe that this distance will be + + + align:start position:0% +to believe that this distance will be +fine and so the discussion that we just + + align:start position:0% +fine and so the discussion that we just + + + align:start position:0% +fine and so the discussion that we just +tell about what is a good representation + + align:start position:0% +tell about what is a good representation + + + align:start position:0% +tell about what is a good representation +is gonna kick in okay + + align:start position:0% +is gonna kick in okay + + + align:start position:0% +is gonna kick in okay +but the assumption you make in this case + + align:start position:0% +but the assumption you make in this case + + + align:start position:0% +but the assumption you make in this case +visually it's very easy it's low + + align:start position:0% +visually it's very easy it's low + + + align:start position:0% +visually it's very easy it's low +dimension is that nearby things have + + align:start position:0% +dimension is that nearby things have + + + align:start position:0% +dimension is that nearby things have +similar labels one thing that I forgot + + align:start position:0% +similar labels one thing that I forgot + + + align:start position:0% +similar labels one thing that I forgot +to tell you in the previous slides but + + align:start position:0% +to tell you in the previous slides but + + + align:start position:0% +to tell you in the previous slides but +it's key is exactly this observation + + align:start position:0% +it's key is exactly this observation + + + align:start position:0% +it's key is exactly this observation +that we move away in machine learning we + + align:start position:0% +that we move away in machine learning we + + + align:start position:0% +that we move away in machine learning we +typically move away from situation like + + align:start position:0% +typically move away from situation like + + + align:start position:0% +typically move away from situation like +this one where you can do visual + + align:start position:0% +this one where you can do visual + + + align:start position:0% +this one where you can do visual +inspection and you have low + + align:start position:0% +inspection and you have low + + + align:start position:0% +inspection and you have low +dimensionality to kind of situation like + + align:start position:0% +dimensionality to kind of situation like + + + align:start position:0% +dimensionality to kind of situation like +the one I just show you in a minute + + align:start position:0% +the one I just show you in a minute + + + align:start position:0% +the one I just show you in a minute +before where you have images and if you + + align:start position:0% +before where you have images and if you + + + align:start position:0% +before where you have images and if you +have to think of each of these circles + + align:start position:0% +have to think of each of these circles + + + align:start position:0% +have to think of each of these circles +as an image you won't be able to draw it + + align:start position:0% +as an image you won't be able to draw it + + + align:start position:0% +as an image you won't be able to draw it +because it's gonna be a several hundreds + + align:start position:0% +because it's gonna be a several hundreds + + + align:start position:0% +because it's gonna be a several hundreds +typical or tens dimensional vector okay + + align:start position:0% +typical or tens dimensional vector okay + + + align:start position:0% +typical or tens dimensional vector okay +so the game is kind of different you + + align:start position:0% +so the game is kind of different you + + + align:start position:0% +so the game is kind of different you +know how many of the things that you + + align:start position:0% +know how many of the things that you + + + align:start position:0% +know how many of the things that you +know can we still do this kind of stuff + + align:start position:0% +know can we still do this kind of stuff + + + align:start position:0% +know can we still do this kind of stuff +can we just say that close things or + + align:start position:0% +can we just say that close things or + + + align:start position:0% +can we just say that close things or +should have the same semantic content + + align:start position:0% +should have the same semantic content + + + align:start position:0% +should have the same semantic content +that's another question we try to answer + + align:start position:0% +that's another question we try to answer + + + align:start position:0% +that's another question we try to answer +okay but so I just want to do a bit of + + align:start position:0% +okay but so I just want to do a bit of + + + align:start position:0% +okay but so I just want to do a bit of +an exception this is a big deal okay + + align:start position:0% +an exception this is a big deal okay + + + align:start position:0% +an exception this is a big deal okay +going from low dimension to very high + + align:start position:0% +going from low dimension to very high + + + align:start position:0% +going from low dimension to very high +dimensions alright but let's stick for a + + align:start position:0% +dimensions alright but let's stick for a + + + align:start position:0% +dimensions alright but let's stick for a +minute to the idea that nearby things + + align:start position:0% +minute to the idea that nearby things + + + align:start position:0% +minute to the idea that nearby things +should have the same label and just just + + align:start position:0% +should have the same label and just just + + + align:start position:0% +should have the same label and just just +write the one line that write down the + + align:start position:0% +write the one line that write down the + + + align:start position:0% +write the one line that write down the +algorithm it's the kind of cases where + + align:start position:0% +algorithm it's the kind of cases where + + + align:start position:0% +algorithm it's the kind of cases where +it's harder to write it down than to + + align:start position:0% +it's harder to write it down than to + + + align:start position:0% +it's harder to write it down than to +code it up we'll just explain what it is + + align:start position:0% +code it up we'll just explain what it is + + + align:start position:0% +code it up we'll just explain what it is +it's super simple what you + + align:start position:0% +it's super simple what you + + + align:start position:0% +it's super simple what you +is you have data points X I so X I is + + align:start position:0% +is you have data points X I so X I is + + + align:start position:0% +is you have data points X I so X I is +the training set the input data in the + + align:start position:0% +the training set the input data in the + + + align:start position:0% +the training set the input data in the +training set X bar is what I call X new + + align:start position:0% +training set X bar is what I call X new + + + align:start position:0% +training set X bar is what I call X new +before it's a new point what you do is + + align:start position:0% +before it's a new point what you do is + + + align:start position:0% +before it's a new point what you do is +that you search this just says look for + + align:start position:0% +that you search this just says look for + + + align:start position:0% +that you search this just says look for +the index of the closest point that's + + align:start position:0% +the index of the closest point that's + + + align:start position:0% +the index of the closest point that's +what you did before okay so here I prime + + align:start position:0% +what you did before okay so here I prime + + + align:start position:0% +what you did before okay so here I prime +is the index of the point X I closes to + + align:start position:0% +is the index of the point X I closes to + + + align:start position:0% +is the index of the point X I closes to +X bar once you find it go in your data + + align:start position:0% +X bar once you find it go in your data + + + align:start position:0% +X bar once you find it go in your data +set and find the label of that point and + + align:start position:0% +set and find the label of that point and + + + align:start position:0% +set and find the label of that point and +then assign that label to the new point + + align:start position:0% +then assign that label to the new point + + + align:start position:0% +then assign that label to the new point +that make sense everybody's happy + + align:start position:0% +that make sense everybody's happy + + + align:start position:0% +that make sense everybody's happy +not super complicated fair enough + + align:start position:0% +not super complicated fair enough + + + align:start position:0% +not super complicated fair enough +how does it work so let me see if I can + + align:start position:0% +how does it work so let me see if I can + + + align:start position:0% +how does it work so let me see if I can +do this + + align:start position:0% + + + + align:start position:0% + +this is extremely fancy code let's see + + align:start position:0% +this is extremely fancy code let's see + + + align:start position:0% +this is extremely fancy code let's see +all right so what I do let me do it it'd + + align:start position:0% +all right so what I do let me do it it'd + + + align:start position:0% +all right so what I do let me do it it'd +be smaller so this is just a simple two + + align:start position:0% +be smaller so this is just a simple two + + + align:start position:0% +be smaller so this is just a simple two +dimensional data sets I take 40 points + + align:start position:0% +dimensional data sets I take 40 points + + + align:start position:0% +dimensional data sets I take 40 points +this is just to the data set look like + + align:start position:0% +this is just to the data set look like + + + align:start position:0% +this is just to the data set look like +this the data set is the one on the left + + align:start position:0% +this the data set is the one on the left + + + align:start position:0% +this the data set is the one on the left +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and what I do I take 40 points and to + + align:start position:0% +and what I do I take 40 points and to + + + align:start position:0% +and what I do I take 40 points and to +make it a bit more complex + + align:start position:0% +make it a bit more complex + + + align:start position:0% +make it a bit more complex +I flip some of the labels okay so you + + align:start position:0% +I flip some of the labels okay so you + + + align:start position:0% +I flip some of the labels okay so you +basically see that the two data sets are + + align:start position:0% +basically see that the two data sets are + + + align:start position:0% +basically see that the two data sets are +this is called the two moons data set or + + align:start position:0% +this is called the two moons data set or + + + align:start position:0% +this is called the two moons data set or +something like this and what I did is + + align:start position:0% +something like this and what I did is + + + align:start position:0% +something like this and what I did is +that some of the labels in this see I + + align:start position:0% +that some of the labels in this see I + + + align:start position:0% +that some of the labels in this see I +change color I change label okay so that + + align:start position:0% +change color I change label okay so that + + + align:start position:0% +change color I change label okay so that +I make the problem a bit harder and here + + align:start position:0% +I make the problem a bit harder and here + + + align:start position:0% +I make the problem a bit harder and here +it's what you will fortunately you don't + + align:start position:0% +it's what you will fortunately you don't + + + align:start position:0% +it's what you will fortunately you don't +have in practice okay here we're + + align:start position:0% +have in practice okay here we're + + + align:start position:0% +have in practice okay here we're +cheating we're doing just the + + align:start position:0% +cheating we're doing just the + + + align:start position:0% +cheating we're doing just the +simulations we're looking at the future + + align:start position:0% +simulations we're looking at the future + + + align:start position:0% +simulations we're looking at the future +we assumed that because we can generate + + align:start position:0% +we assumed that because we can generate + + + align:start position:0% +we assumed that because we can generate +this data we can look at the future and + + align:start position:0% +this data we can look at the future and + + + align:start position:0% +this data we can look at the future and +check how we're going to do and future + + align:start position:0% +check how we're going to do and future + + + align:start position:0% +check how we're going to do and future +data so you can think of these as future + + align:start position:0% +data so you can think of these as future + + + align:start position:0% +data so you can think of these as future +data that typically you don't have so + + align:start position:0% +data that typically you don't have so + + + align:start position:0% +data that typically you don't have so +here you're a normal human being here + + align:start position:0% +here you're a normal human being here + + + align:start position:0% +here you're a normal human being here +you're playing God and looking at the + + align:start position:0% +you're playing God and looking at the + + + align:start position:0% +you're playing God and looking at the +future okay because we just want to do a + + align:start position:0% +future okay because we just want to do a + + + align:start position:0% +future okay because we just want to do a +little simulation so based on that we + + align:start position:0% +little simulation so based on that we + + + align:start position:0% +little simulation so based on that we +can just go here put one string and then + + align:start position:0% +can just go here put one string and then + + + align:start position:0% +can just go here put one string and then +test and plot so what you see here is + + align:start position:0% +test and plot so what you see here is + + + align:start position:0% +test and plot so what you see here is +the so-called decision boundary okay + + align:start position:0% +the so-called decision boundary okay + + + align:start position:0% +the so-called decision boundary okay +what I did is what we it's the cook is + + align:start position:0% +what I did is what we it's the cook is + + + align:start position:0% +what I did is what we it's the cook is +exactly that one line of code you saw + + align:start position:0% +exactly that one line of code you saw + + + align:start position:0% +exactly that one line of code you saw +before okay and what I did is this case + + align:start position:0% +before okay and what I did is this case + + + align:start position:0% +before okay and what I did is this case +I can draw it because it's low dimension + + align:start position:0% +I can draw it because it's low dimension + + + align:start position:0% +I can draw it because it's low dimension +and basically what they do is that I + + align:start position:0% +and basically what they do is that I + + + align:start position:0% +and basically what they do is that I +just put in the regions where I think I + + align:start position:0% +just put in the regions where I think I + + + align:start position:0% +just put in the regions where I think I +should put orange and the region where I + + align:start position:0% +should put orange and the region where I + + + align:start position:0% +should put orange and the region where I +think I should put blue okay and here + + align:start position:0% +think I should put blue okay and here + + + align:start position:0% +think I should put blue okay and here +you can kind of see what's going on this + + align:start position:0% +you can kind of see what's going on this + + + align:start position:0% +you can kind of see what's going on this +is actually very good on the data right + + align:start position:0% +is actually very good on the data right + + + align:start position:0% +is actually very good on the data right +how many mistakes do you make on the new + + align:start position:0% +how many mistakes do you make on the new + + + align:start position:0% +how many mistakes do you make on the new +data set oh sorry on the on the training + + align:start position:0% +data set oh sorry on the on the training + + + align:start position:0% +data set oh sorry on the on the training +set zero it's perfect okay is that a + + align:start position:0% +set zero it's perfect okay is that a + + + align:start position:0% +set zero it's perfect okay is that a +good idea well when you look at it here + + align:start position:0% +good idea well when you look at it here + + + align:start position:0% +good idea well when you look at it here +it doesn't look that good okay there is + + align:start position:0% +it doesn't look that good okay there is + + + align:start position:0% +it doesn't look that good okay there is +this whole region of point for example + + align:start position:0% +this whole region of point for example + + + align:start position:0% +this whole region of point for example +there are going to be + + align:start position:0% +there are going to be + + + align:start position:0% +there are going to be +predicted to be orange but they're + + align:start position:0% +predicted to be orange but they're + + + align:start position:0% +predicted to be orange but they're +actually blue of course if you want to + + align:start position:0% +actually blue of course if you want to + + + align:start position:0% +actually blue of course if you want to +have zero air on the training set + + align:start position:0% +have zero air on the training set + + + align:start position:0% +have zero air on the training set +there's nothing else you can do right + + align:start position:0% +there's nothing else you can do right + + + align:start position:0% +there's nothing else you can do right +because you see you have this orange + + align:start position:0% +because you see you have this orange + + + align:start position:0% +because you see you have this orange +point here you have these two orange + + align:start position:0% +point here you have these two orange + + + align:start position:0% +point here you have these two orange +points here and you want to go and + + align:start position:0% +points here and you want to go and + + + align:start position:0% +points here and you want to go and +follow them so there's nothing you can + + align:start position:0% +follow them so there's nothing you can + + + align:start position:0% +follow them so there's nothing you can +do so this is the first observation the + + align:start position:0% +do so this is the first observation the + + + align:start position:0% +do so this is the first observation the +second observation is the curve if you + + align:start position:0% +second observation is the curve if you + + + align:start position:0% +second observation is the curve if you +look close enough it's piecewise linear + + align:start position:0% +look close enough it's piecewise linear + + + align:start position:0% +look close enough it's piecewise linear +it's like a sequence of piece linear + + align:start position:0% +it's like a sequence of piece linear + + + align:start position:0% +it's like a sequence of piece linear +pieces stuck together if we just try to + + align:start position:0% +pieces stuck together if we just try to + + + align:start position:0% +pieces stuck together if we just try to +do a little game and generate some new + + align:start position:0% +do a little game and generate some new + + + align:start position:0% +do a little game and generate some new +data okay so imagine again I'm playing + + align:start position:0% +data okay so imagine again I'm playing + + + align:start position:0% +data okay so imagine again I'm playing +God now I judge enervate a new data set + + align:start position:0% +God now I judge enervate a new data set + + + align:start position:0% +God now I judge enervate a new data set +that should look like so take another + + align:start position:0% +that should look like so take another + + + align:start position:0% +that should look like so take another +peek at this okay so now I generate them + + align:start position:0% +peek at this okay so now I generate them + + + align:start position:0% +peek at this okay so now I generate them +I plot them I train + + align:start position:0% + + + + align:start position:0% + +and now let's test + + align:start position:0% + + + + align:start position:0% + +okay if you remember that decision + + align:start position:0% +okay if you remember that decision + + + align:start position:0% +okay if you remember that decision +curves you've seen before what do you + + align:start position:0% +curves you've seen before what do you + + + align:start position:0% +curves you've seen before what do you +notice here they're very different + + align:start position:0% +notice here they're very different + + + align:start position:0% +notice here they're very different +okay for example that one before if you + + align:start position:0% +okay for example that one before if you + + + align:start position:0% +okay for example that one before if you +remember we notice it was going all the + + align:start position:0% +remember we notice it was going all the + + + align:start position:0% +remember we notice it was going all the +way down here to follow those couple of + + align:start position:0% +way down here to follow those couple of + + + align:start position:0% +way down here to follow those couple of +points but here you don't have those + + align:start position:0% +points but here you don't have those + + + align:start position:0% +points but here you don't have those +couple of points okay so now is that a + + align:start position:0% +couple of points okay so now is that a + + + align:start position:0% +couple of points okay so now is that a +good thing or a bad thing well the point + + align:start position:0% +good thing or a bad thing well the point + + + align:start position:0% +good thing or a bad thing well the point +here is that because you have so few + + align:start position:0% +here is that because you have so few + + + align:start position:0% +here is that because you have so few +points the moment you start to just fit + + align:start position:0% +points the moment you start to just fit + + + align:start position:0% +points the moment you start to just fit +the date that this will happen okay you + + align:start position:0% +the date that this will happen okay you + + + align:start position:0% +the date that this will happen okay you +have something that changes all the time + + align:start position:0% +have something that changes all the time + + + align:start position:0% +have something that changes all the time +it's very unstable that's a key word + + align:start position:0% +it's very unstable that's a key word + + + align:start position:0% +it's very unstable that's a key word +okay you have something that you change + + align:start position:0% +okay you have something that you change + + + align:start position:0% +okay you have something that you change +the data just a little bit and changes + + align:start position:0% +the data just a little bit and changes + + + align:start position:0% +the data just a little bit and changes +completely that sounds like a bad idea + + align:start position:0% +completely that sounds like a bad idea + + + align:start position:0% +completely that sounds like a bad idea +okay if I want to make prediction if I + + align:start position:0% +okay if I want to make prediction if I + + + align:start position:0% +okay if I want to make prediction if I +keep on getting little data you know + + align:start position:0% +keep on getting little data you know + + + align:start position:0% +keep on getting little data you know +slightly different data and I change my + + align:start position:0% +slightly different data and I change my + + + align:start position:0% +slightly different data and I change my +mind completely that's probably not a + + align:start position:0% +mind completely that's probably not a + + + align:start position:0% +mind completely that's probably not a +good way to make prediction about + + align:start position:0% +good way to make prediction about + + + align:start position:0% +good way to make prediction about +anything okay and this is happening all + + align:start position:0% +anything okay and this is happening all + + + align:start position:0% +anything okay and this is happening all +the time here and it's exactly because + + align:start position:0% +the time here and it's exactly because + + + align:start position:0% +the time here and it's exactly because +our algorithm means in some sense is + + align:start position:0% +our algorithm means in some sense is + + + align:start position:0% +our algorithm means in some sense is +greedy you just try to get perfect + + align:start position:0% +greedy you just try to get perfect + + + align:start position:0% +greedy you just try to get perfect +performance on the training set without + + align:start position:0% +performance on the training set without + + + align:start position:0% +performance on the training set without +much of worrying much about the future + + align:start position:0% +much of worrying much about the future + + + align:start position:0% +much of worrying much about the future +let's do it just once more + + align:start position:0% + + + + align:start position:0% + +okay and we keeping keep on going okay + + align:start position:0% +okay and we keeping keep on going okay + + + align:start position:0% +okay and we keeping keep on going okay +is gonna change all the time all the + + align:start position:0% +is gonna change all the time all the + + + align:start position:0% +is gonna change all the time all the +time of course no I don't know how much + + align:start position:0% +time of course no I don't know how much + + + align:start position:0% +time of course no I don't know how much +I can push this because it's not super + + align:start position:0% +I can push this because it's not super + + + align:start position:0% +I can push this because it's not super +duper fast but let's try 30 + + align:start position:0% + + + + align:start position:0% + +so what I did now is just that I hope + + align:start position:0% +so what I did now is just that I hope + + + align:start position:0% +so what I did now is just that I hope +mented the number of points in my + + align:start position:0% +mented the number of points in my + + + align:start position:0% +mented the number of points in my +training set it was a twenty or thirty I + + align:start position:0% +training set it was a twenty or thirty I + + + align:start position:0% +training set it was a twenty or thirty I +remember now I make it a hundred + + align:start position:0% +remember now I make it a hundred + + + align:start position:0% +remember now I make it a hundred +so now you should see okay so this is + + align:start position:0% +so now you should see okay so this is + + + align:start position:0% +so now you should see okay so this is +one solution we want to play the same + + align:start position:0% +one solution we want to play the same + + + align:start position:0% +one solution we want to play the same +game just want to generate in other data + + align:start position:0% +game just want to generate in other data + + + align:start position:0% +game just want to generate in other data +sets of the same so maybe now we're + + align:start position:0% +sets of the same so maybe now we're + + + align:start position:0% +sets of the same so maybe now we're +gonna it might be that I took them all + + align:start position:0% +gonna it might be that I took them all + + + align:start position:0% +gonna it might be that I took them all +and I remember how many they are no I + + align:start position:0% +and I remember how many they are no I + + + align:start position:0% +and I remember how many they are no I +didn't take them all so what do you see + + align:start position:0% +didn't take them all so what do you see + + + align:start position:0% +didn't take them all so what do you see +now we are doing exactly the same thing + + align:start position:0% +now we are doing exactly the same thing + + + align:start position:0% +now we are doing exactly the same thing +okay and this is something that you can + + align:start position:0% +okay and this is something that you can + + + align:start position:0% +okay and this is something that you can +absolutely not do in practice because + + align:start position:0% +absolutely not do in practice because + + + align:start position:0% +absolutely not do in practice because +you cannot just generate data sets but + + align:start position:0% +you cannot just generate data sets but + + + align:start position:0% +you cannot just generate data sets but +here what you see is that I just + + align:start position:0% +here what you see is that I just + + + align:start position:0% +here what you see is that I just +augmented the number of training set + + align:start position:0% +augmented the number of training set + + + align:start position:0% +augmented the number of training set +points and what you see that now the + + align:start position:0% +points and what you see that now the + + + align:start position:0% +points and what you see that now the +solution does change but not as much + + align:start position:0% +solution does change but not as much + + + align:start position:0% +solution does change but not as much +okay and you can kind of start to see + + align:start position:0% +okay and you can kind of start to see + + + align:start position:0% +okay and you can kind of start to see +that there is something going on a bit + + align:start position:0% +that there is something going on a bit + + + align:start position:0% +that there is something going on a bit +like this here okay so this one actually + + align:start position:0% +like this here okay so this one actually + + + align:start position:0% +like this here okay so this one actually +looks pretty bad let's try to do one + + align:start position:0% +looks pretty bad let's try to do one + + + align:start position:0% +looks pretty bad let's try to do one +more + + align:start position:0% + + + + align:start position:0% + +okay so again it does change a lot but + + align:start position:0% +okay so again it does change a lot but + + + align:start position:0% +okay so again it does change a lot but +not as much as before and you roughly + + align:start position:0% +not as much as before and you roughly + + + align:start position:0% +not as much as before and you roughly +see that this guy says that here it + + align:start position:0% +see that this guy says that here it + + + align:start position:0% +see that this guy says that here it +should be orange and here should be blue + + align:start position:0% +should be orange and here should be blue + + + align:start position:0% +should be orange and here should be blue +okay so that's kind of what you expect + + align:start position:0% +okay so that's kind of what you expect + + + align:start position:0% +okay so that's kind of what you expect +the number of the more points you get + + align:start position:0% +the number of the more points you get + + + align:start position:0% +the number of the more points you get +the better your solution would get and + + align:start position:0% +the better your solution would get and + + + align:start position:0% +the better your solution would get and +if I put here all the possible points + + align:start position:0% +if I put here all the possible points + + + align:start position:0% +if I put here all the possible points +what you will start to see is that the + + align:start position:0% +what you will start to see is that the + + + align:start position:0% +what you will start to see is that the +closest point to any point here will be + + align:start position:0% +closest point to any point here will be + + + align:start position:0% +closest point to any point here will be +a blue point okay so will be perfect so + + align:start position:0% +a blue point okay so will be perfect so + + + align:start position:0% +a blue point okay so will be perfect so +if I ask you if this is a good alga + + align:start position:0% +if I ask you if this is a good alga + + + align:start position:0% +if I ask you if this is a good alga +rhythm or not + + align:start position:0% +rhythm or not + + + align:start position:0% +rhythm or not +what would you say it's kind of over + + align:start position:0% +what would you say it's kind of over + + + align:start position:0% +what would you say it's kind of over +fitting the data but it's not always + + align:start position:0% +fitting the data but it's not always + + + align:start position:0% +fitting the data but it's not always +overfitting the date if they did are + + align:start position:0% +overfitting the date if they did are + + + align:start position:0% +overfitting the date if they did are +good oh it's a good idea to feed them + + align:start position:0% +good oh it's a good idea to feed them + + + align:start position:0% +good oh it's a good idea to feed them +okay but so in some sense these + + align:start position:0% +okay but so in some sense these + + + align:start position:0% +okay but so in some sense these +algorithm doesn't have a way to prevent + + align:start position:0% +algorithm doesn't have a way to prevent + + + align:start position:0% +algorithm doesn't have a way to prevent +itself to fall in love with the data + + align:start position:0% +itself to fall in love with the data + + + align:start position:0% +itself to fall in love with the data +when they're very few and if you have + + align:start position:0% +when they're very few and if you have + + + align:start position:0% +when they're very few and if you have +very few data points you start to just + + align:start position:0% +very few data points you start to just + + + align:start position:0% +very few data points you start to just +wiggle around become extremely unstable + + align:start position:0% +wiggle around become extremely unstable + + + align:start position:0% +wiggle around become extremely unstable +change your mind all the time + + align:start position:0% +change your mind all the time + + + align:start position:0% +change your mind all the time +if the data are enough it stabilizes and + + align:start position:0% +if the data are enough it stabilizes and + + + align:start position:0% +if the data are enough it stabilizes and +in some sense is the setting we're + + align:start position:0% +in some sense is the setting we're + + + align:start position:0% +in some sense is the setting we're +fitting the data or as she sang + + align:start position:0% +fitting the data or as she sang + + + align:start position:0% +fitting the data or as she sang +overfitting the data is actually not a + + align:start position:0% +overfitting the data is actually not a + + + align:start position:0% +overfitting the data is actually not a +bad thing okay so this is what's going + + align:start position:0% +bad thing okay so this is what's going + + + align:start position:0% +bad thing okay so this is what's going +on here + + align:start position:0% + + + + align:start position:0% + +fitting a bit too much so if you look + + align:start position:0% +fitting a bit too much so if you look + + + align:start position:0% +fitting a bit too much so if you look +here so here if you look what you're + + align:start position:0% +here so here if you look what you're + + + align:start position:0% +here so here if you look what you're +doing here you're always fitting the + + align:start position:0% +doing here you're always fitting the + + + align:start position:0% +doing here you're always fitting the +data okay but here you didn't doing + + align:start position:0% +data okay but here you didn't doing + + + align:start position:0% +data okay but here you didn't doing +nothing else and so if you have a few + + align:start position:0% +nothing else and so if you have a few + + + align:start position:0% +nothing else and so if you have a few +data points fit in the data is fine if + + align:start position:0% +data points fit in the data is fine if + + + align:start position:0% +data points fit in the data is fine if +you have sorry if you have many data + + align:start position:0% +you have sorry if you have many data + + + align:start position:0% +you have sorry if you have many data +points fitting data is just fine if you + + align:start position:0% +points fitting data is just fine if you + + + align:start position:0% +points fitting data is just fine if you +have few data points by fitting them you + + align:start position:0% +have few data points by fitting them you + + + align:start position:0% +have few data points by fitting them you +in some sense over fit in the sense that + + align:start position:0% +in some sense over fit in the sense that + + + align:start position:0% +in some sense over fit in the sense that +when you look at new data points you + + align:start position:0% +when you look at new data points you + + + align:start position:0% +when you look at new data points you +have done a bit too much okay what you + + align:start position:0% +have done a bit too much okay what you + + + align:start position:0% +have done a bit too much okay what you +saw before that you get this thinking + + align:start position:0% +saw before that you get this thinking + + + align:start position:0% +saw before that you get this thinking +that it's very good because it perfectly + + align:start position:0% +that it's very good because it perfectly + + + align:start position:0% +that it's very good because it perfectly +fits that but it's overfitting with + + align:start position:0% +fits that but it's overfitting with + + + align:start position:0% +fits that but it's overfitting with +respect to the future whereas here the + + align:start position:0% +respect to the future whereas here the + + + align:start position:0% +respect to the future whereas here the +fitting on the left-hand side kind of + + align:start position:0% +fitting on the left-hand side kind of + + + align:start position:0% +fitting on the left-hand side kind of +reflect not too badly the fitting on the + + align:start position:0% +reflect not too badly the fitting on the + + + align:start position:0% +reflect not too badly the fitting on the +right-hand side okay so this this the + + align:start position:0% +right-hand side okay so this this the + + + align:start position:0% +right-hand side okay so this this the +idea of overfitting and stability that + + align:start position:0% +idea of overfitting and stability that + + + align:start position:0% +idea of overfitting and stability that +came out in this discussion are key okay + + align:start position:0% +came out in this discussion are key okay + + + align:start position:0% +came out in this discussion are key okay +if you want everything we're going to do + + align:start position:0% +if you want everything we're going to do + + + align:start position:0% +if you want everything we're going to do +in the next three hours is understand + + align:start position:0% +in the next three hours is understand + + + align:start position:0% +in the next three hours is understand +how you can prevent overfitting and + + align:start position:0% +how you can prevent overfitting and + + + align:start position:0% +how you can prevent overfitting and +build good way to stabilize your + + align:start position:0% +build good way to stabilize your + + + align:start position:0% +build good way to stabilize your +algorithms okay so let's go back here + + align:start position:0% +algorithms okay so let's go back here + + + align:start position:0% +algorithms okay so let's go back here +and it's gonna be quick because if I ask + + align:start position:0% +and it's gonna be quick because if I ask + + + align:start position:0% +and it's gonna be quick because if I ask +you what is this + + align:start position:0% +you what is this + + + align:start position:0% +you what is this +what would you say so the idea is that + + align:start position:0% +what would you say so the idea is that + + + align:start position:0% +what would you say so the idea is that +when you have a situation like this + + align:start position:0% +when you have a situation like this + + + align:start position:0% +when you have a situation like this +you're still pretty much able to say + + align:start position:0% +you're still pretty much able to say + + + align:start position:0% +you're still pretty much able to say +what's the right answer and what you're + + align:start position:0% +what's the right answer and what you're + + + align:start position:0% +what's the right answer and what you're +gonna do is that you're gonna move away + + align:start position:0% +gonna do is that you're gonna move away + + + align:start position:0% +gonna do is that you're gonna move away +from just saying what's the closest + + align:start position:0% +from just saying what's the closest + + + align:start position:0% +from just saying what's the closest +point and you just look at a few more + + align:start position:0% +point and you just look at a few more + + + align:start position:0% +point and you just look at a few more +points you just don't look at one okay + + align:start position:0% +points you just don't look at one okay + + + align:start position:0% +points you just don't look at one okay +you look at how many boo-boo is a very + + align:start position:0% +you look at how many boo-boo is a very + + + align:start position:0% +you look at how many boo-boo is a very +useful Italian word it means I don't + + align:start position:0% +useful Italian word it means I don't + + + align:start position:0% +useful Italian word it means I don't +know so this algorithm it's called the K + + align:start position:0% +know so this algorithm it's called the K + + + align:start position:0% +know so this algorithm it's called the K +nearest neighbor algorithm it's probably + + align:start position:0% +nearest neighbor algorithm it's probably + + + align:start position:0% +nearest neighbor algorithm it's probably +the second simplest algorithm you can + + align:start position:0% +the second simplest algorithm you can + + + align:start position:0% +the second simplest algorithm you can +think of it's kind of the same as before + + align:start position:0% +think of it's kind of the same as before + + + align:start position:0% +think of it's kind of the same as before +the notation here is a bit boring but + + align:start position:0% +the notation here is a bit boring but + + + align:start position:0% +the notation here is a bit boring but +it's basically saying take the points + + align:start position:0% +it's basically saying take the points + + + align:start position:0% +it's basically saying take the points +given a new points check the distance + + align:start position:0% +given a new points check the distance + + + align:start position:0% +given a new points check the distance +with everybody sort it and take the + + align:start position:0% +with everybody sort it and take the + + + align:start position:0% +with everybody sort it and take the +first K okay if it's a classification + + align:start position:0% +first K okay if it's a classification + + + align:start position:0% +first K okay if it's a classification +probably probably good idea to take a + + align:start position:0% +probably probably good idea to take a + + + align:start position:0% +probably probably good idea to take a +odd number for K so that you can then + + align:start position:0% +odd number for K so that you can then + + + align:start position:0% +odd number for K so that you can then +just have a voting and basically + + align:start position:0% +just have a voting and basically + + + align:start position:0% +just have a voting and basically +everybody votes H vote counts one and + + align:start position:0% +everybody votes H vote counts one and + + + align:start position:0% +everybody votes H vote counts one and +somebody says blue somebody says orange + + align:start position:0% +somebody says blue somebody says orange + + + align:start position:0% +somebody says blue somebody says orange +and any and you make a decision okay + + align:start position:0% + + + + align:start position:0% + +fair enough + + align:start position:0% +fair enough + + + align:start position:0% +fair enough +well how does this work you can kind of + + align:start position:0% +well how does this work you can kind of + + + align:start position:0% +well how does this work you can kind of +imagine so so we have to do so for + + align:start position:0% +imagine so so we have to do so for + + + align:start position:0% +imagine so so we have to do so for +example here we had this guy okay now + + align:start position:0% +example here we had this guy okay now + + + align:start position:0% +example here we had this guy okay now +let's just put K well let's make this a + + align:start position:0% +let's just put K well let's make this a + + + align:start position:0% +let's just put K well let's make this a +bit smaller so we do forty generate plot + + align:start position:0% +bit smaller so we do forty generate plot + + + align:start position:0% +bit smaller so we do forty generate plot +train boring yes okay + + align:start position:0% +train boring yes okay + + + align:start position:0% +train boring yes okay +well we got a bit lucky okay this is + + align:start position:0% +well we got a bit lucky okay this is + + + align:start position:0% +well we got a bit lucky okay this is +actually a good dataset because in some + + align:start position:0% +actually a good dataset because in some + + + align:start position:0% +actually a good dataset because in some +sense there are no what you might call + + align:start position:0% +sense there are no what you might call + + + align:start position:0% +sense there are no what you might call +outliers there are not orange point that + + align:start position:0% +outliers there are not orange point that + + + align:start position:0% +outliers there are not orange point that +really go and sit in the blue so I just + + align:start position:0% +really go and sit in the blue so I just + + + align:start position:0% +really go and sit in the blue so I just +want to show you a bit of a dramatic + + align:start position:0% +want to show you a bit of a dramatic + + + align:start position:0% +want to show you a bit of a dramatic +effect of this so let me just try to + + align:start position:0% +effect of this so let me just try to + + + align:start position:0% +effect of this so let me just try to +redo this one so that we get the more + + align:start position:0% +redo this one so that we get the more + + + align:start position:0% +redo this one so that we get the more +yes and you should do okay so this is + + align:start position:0% +yes and you should do okay so this is + + + align:start position:0% +yes and you should do okay so this is +nearest neighbor is the solution you get + + align:start position:0% +nearest neighbor is the solution you get + + + align:start position:0% +nearest neighbor is the solution you get +it's not too horrible but for example + + align:start position:0% +it's not too horrible but for example + + + align:start position:0% +it's not too horrible but for example +you see that the start follows this guy + + align:start position:0% +you see that the start follows this guy + + + align:start position:0% +you see that the start follows this guy +okay now what you can do is that just + + align:start position:0% +okay now what you can do is that just + + + align:start position:0% +okay now what you can do is that just +can just go in and say for well for is a + + align:start position:0% +can just go in and say for well for is a + + + align:start position:0% +can just go in and say for well for is a +bad idea five you retrain on the same + + align:start position:0% + + + + align:start position:0% + +and all of a sudden it does ignore this + + align:start position:0% +and all of a sudden it does ignore this + + + align:start position:0% +and all of a sudden it does ignore this +guy because the moment that you put more + + align:start position:0% +guy because the moment that you put more + + + align:start position:0% +guy because the moment that you put more +in well I just realized that he's + + align:start position:0% +in well I just realized that he's + + + align:start position:0% +in well I just realized that he's +surrounded by blue guys so it's probably + + align:start position:0% +surrounded by blue guys so it's probably + + + align:start position:0% +surrounded by blue guys so it's probably +just his vote discount one against four + + align:start position:0% +just his vote discount one against four + + + align:start position:0% +just his vote discount one against four +okay and you can keep on going and the + + align:start position:0% +okay and you can keep on going and the + + + align:start position:0% +okay and you can keep on going and the +idea here is that the more you make this + + align:start position:0% +idea here is that the more you make this + + + align:start position:0% +idea here is that the more you make this +big the more your solution is going to + + align:start position:0% +big the more your solution is going to + + + align:start position:0% +big the more your solution is going to +be what well you can say it's gonna be + + align:start position:0% +be what well you can say it's gonna be + + + align:start position:0% +be what well you can say it's gonna be +good but it's actually not true because + + align:start position:0% +good but it's actually not true because + + + align:start position:0% +good but it's actually not true because +if you start to put cake too big at some + + align:start position:0% +if you start to put cake too big at some + + + align:start position:0% +if you start to put cake too big at some +point all you're doing is counting how + + align:start position:0% +point all you're doing is counting how + + + align:start position:0% +point all you're doing is counting how +many points you have in class one + + align:start position:0% +many points you have in class one + + + align:start position:0% +many points you have in class one +counting how many points you have in + + align:start position:0% +counting how many points you have in + + + align:start position:0% +counting how many points you have in +class two and always say the same thing + + align:start position:0% +class two and always say the same thing + + + align:start position:0% +class two and always say the same thing +okay so how many we have put here twenty + + align:start position:0% +okay so how many we have put here twenty + + + align:start position:0% +okay so how many we have put here twenty +what you start to see is that you start + + align:start position:0% +what you start to see is that you start + + + align:start position:0% +what you start to see is that you start +to obtain a decision boundary which is + + align:start position:0% +to obtain a decision boundary which is + + + align:start position:0% +to obtain a decision boundary which is +simpler and simpler and simpler okay it + + align:start position:0% +simpler and simpler and simpler okay it + + + align:start position:0% +simpler and simpler and simpler okay it +looks kind of linear here what you will + + align:start position:0% +looks kind of linear here what you will + + + align:start position:0% +looks kind of linear here what you will +see is that suppose that now I + + align:start position:0% +see is that suppose that now I + + + align:start position:0% +see is that suppose that now I +regenerate the data and you remember how + + align:start position:0% +regenerate the data and you remember how + + + align:start position:0% +regenerate the data and you remember how +much it changed before when I was using + + align:start position:0% +much it changed before when I was using + + + align:start position:0% +much it changed before when I was using +nearest neighbor with just k equal to 1 + + align:start position:0% +nearest neighbor with just k equal to 1 + + + align:start position:0% +nearest neighbor with just k equal to 1 +okay so of course here you know it it's + + align:start position:0% +okay so of course here you know it it's + + + align:start position:0% +okay so of course here you know it it's +probabilistic okay so of course I'm + + align:start position:0% +probabilistic okay so of course I'm + + + align:start position:0% +probabilistic okay so of course I'm +gonna get it data that's like the one I + + align:start position:0% +gonna get it data that's like the one I + + + align:start position:0% +gonna get it data that's like the one I +just show you a minute ago and ahead it + + align:start position:0% +just show you a minute ago and ahead it + + + align:start position:0% +just show you a minute ago and ahead it +as fast as possible + + align:start position:0% +as fast as possible + + + align:start position:0% +as fast as possible +because if I pick ten one is gonna look + + align:start position:0% +because if I pick ten one is gonna look + + + align:start position:0% +because if I pick ten one is gonna look +like data and nine are gonna look like + + align:start position:0% +like data and nine are gonna look like + + + align:start position:0% +like data and nine are gonna look like +this okay then when I look like this you + + align:start position:0% +this okay then when I look like this you + + + align:start position:0% +this okay then when I look like this you +see they kind of start to have this kind + + align:start position:0% +see they kind of start to have this kind + + + align:start position:0% +see they kind of start to have this kind +of line like decision boundary + + align:start position:0% +of line like decision boundary + + + align:start position:0% +of line like decision boundary +some twist but it's very simple okay and + + align:start position:0% +some twist but it's very simple okay and + + + align:start position:0% +some twist but it's very simple okay and +at some point if I put K big enough that + + align:start position:0% +at some point if I put K big enough that + + + align:start position:0% +at some point if I put K big enough that +is the number of old points you won't + + align:start position:0% +is the number of old points you won't + + + align:start position:0% +is the number of old points you won't +change any more okay it will just be + + align:start position:0% +change any more okay it will just be + + + align:start position:0% +change any more okay it will just be +exactly dividing the deserts into equal + + align:start position:0% +exactly dividing the deserts into equal + + + align:start position:0% +exactly dividing the deserts into equal +part so they make sense so would it make + + align:start position:0% +part so they make sense so would it make + + + align:start position:0% +part so they make sense so would it make +sense to vote to make different votes + + align:start position:0% +sense to vote to make different votes + + + align:start position:0% +sense to vote to make different votes +essentially the idea is if the point is + + align:start position:0% +essentially the idea is if the point is + + + align:start position:0% +essentially the idea is if the point is +closest this vote should count more than + + align:start position:0% +closest this vote should count more than + + + align:start position:0% +closest this vote should count more than +if a point is more far away yes + + align:start position:0% +if a point is more far away yes + + + align:start position:0% +if a point is more far away yes +absolutely is this you know let's say + + align:start position:0% +absolutely is this you know let's say + + + align:start position:0% +absolutely is this you know let's say +here we're making the simplest thing in + + align:start position:0% +here we're making the simplest thing in + + + align:start position:0% +here we're making the simplest thing in +the world the second simple thing about + + align:start position:0% +the world the second simple thing about + + + align:start position:0% +the world the second simple thing about +this third interesting in the world is + + align:start position:0% +this third interesting in the world is + + + align:start position:0% +this third interesting in the world is +doing that okay and you can see that you + + align:start position:0% +doing that okay and you can see that you + + + align:start position:0% +doing that okay and you can see that you +can go pretty far with this they mean + + align:start position:0% +can go pretty far with this they mean + + + align:start position:0% +can go pretty far with this they mean +it's simple but these are actual + + align:start position:0% +it's simple but these are actual + + + align:start position:0% +it's simple but these are actual +algorithm that are used sometimes and + + align:start position:0% +algorithm that are used sometimes and + + + align:start position:0% +algorithm that are used sometimes and +what you do is that if you just look at + + align:start position:0% +what you do is that if you just look at + + + align:start position:0% +what you do is that if you just look at +this again these are 1 1 explained too + + align:start position:0% +this again these are 1 1 explained too + + + align:start position:0% +this again these are 1 1 explained too +much if you've seen it before it's + + align:start position:0% +much if you've seen it before it's + + + align:start position:0% +much if you've seen it before it's +simple otherwise it doesn't really + + align:start position:0% +simple otherwise it doesn't really + + + align:start position:0% +simple otherwise it doesn't really +matter but the basic idea here is that + + align:start position:0% +matter but the basic idea here is that + + + align:start position:0% +matter but the basic idea here is that +each vote is going to between between 0 + + align:start position:0% +each vote is going to between between 0 + + + align:start position:0% +each vote is going to between between 0 +so you see here I put the distance + + align:start position:0% +so you see here I put the distance + + + align:start position:0% +so you see here I put the distance +between every the new point and all the + + align:start position:0% +between every the new point and all the + + + align:start position:0% +between every the new point and all the +other points on top of an exponential so + + align:start position:0% +other points on top of an exponential so + + + align:start position:0% +other points on top of an exponential so +the number I get is not 1 but is between + + align:start position:0% +the number I get is not 1 but is between + + + align:start position:0% +the number I get is not 1 but is between +0 & 1 if the two points are close in the + + align:start position:0% +0 & 1 if the two points are close in the + + + align:start position:0% +0 & 1 if the two points are close in the +limit suppose that they are the same it + + align:start position:0% +limit suppose that they are the same it + + + align:start position:0% +limit suppose that they are the same it +becomes a 0 and it counts exactly 1 if + + align:start position:0% +becomes a 0 and it counts exactly 1 if + + + align:start position:0% +becomes a 0 and it counts exactly 1 if +they're very far away okay it will be + + align:start position:0% +they're very far away okay it will be + + + align:start position:0% +they're very far away okay it will be +Fei infinity and then it will be close + + align:start position:0% +Fei infinity and then it will be close + + + align:start position:0% +Fei infinity and then it will be close +to 0 so the closest you are the more you + + align:start position:0% +to 0 so the closest you are the more you + + + align:start position:0% +to 0 so the closest you are the more you +count if you want you can read like this + + align:start position:0% +count if you want you can read like this + + + align:start position:0% +count if you want you can read like this +you're sitting on a new point and you + + align:start position:0% +you're sitting on a new point and you + + + align:start position:0% +you're sitting on a new point and you +put like a zooming window a like yeah + + align:start position:0% +put like a zooming window a like yeah + + + align:start position:0% +put like a zooming window a like yeah +like a zooming window of a certain size + + align:start position:0% +like a zooming window of a certain size + + + align:start position:0% +like a zooming window of a certain size +and you basically check that everything + + align:start position:0% +and you basically check that everything + + + align:start position:0% +and you basically check that everything +which is inside this window will be + + align:start position:0% +which is inside this window will be + + + align:start position:0% +which is inside this window will be +close and the more you go far away so + + align:start position:0% +close and the more you go far away so + + + align:start position:0% +close and the more you go far away so +the window is like this okay and you + + align:start position:0% +the window is like this okay and you + + + align:start position:0% +the window is like this okay and you +deform the space so that basically what + + align:start position:0% +deform the space so that basically what + + + align:start position:0% +deform the space so that basically what +you say is things are far away they're + + align:start position:0% +you say is things are far away they're + + + align:start position:0% +you say is things are far away they're +gonna count less and if I move Sigma + + align:start position:0% +gonna count less and if I move Sigma + + + align:start position:0% +gonna count less and if I move Sigma +here I'm somewhat making my visual field + + align:start position:0% +here I'm somewhat making my visual field + + + align:start position:0% +here I'm somewhat making my visual field +if you want larger or smaller okay + + align:start position:0% +if you want larger or smaller okay + + + align:start position:0% +if you want larger or smaller okay +around this one new point there's just a + + align:start position:0% +around this one new point there's just a + + + align:start position:0% +around this one new point there's just a +physical interpretation of what this is + + align:start position:0% +physical interpretation of what this is + + + align:start position:0% +physical interpretation of what this is +doing there 15 other ways of looking at + + align:start position:0% +doing there 15 other ways of looking at + + + align:start position:0% +doing there 15 other ways of looking at +what discussion is doing voting you know + + align:start position:0% +what discussion is doing voting you know + + + align:start position:0% +what discussion is doing voting you know +changing the weight of the vote is + + align:start position:0% +changing the weight of the vote is + + + align:start position:0% +changing the weight of the vote is +another one okay white the Gaussian here + + align:start position:0% +another one okay white the Gaussian here + + + align:start position:0% +another one okay white the Gaussian here +well because just because you can use + + align:start position:0% +well because just because you can use + + + align:start position:0% +well because just because you can use +many many others you can use for example + + align:start position:0% +many many others you can use for example + + + align:start position:0% +many many others you can use for example +window and this is part of your prior + + align:start position:0% +window and this is part of your prior + + + align:start position:0% +window and this is part of your prior +knowledge how much you wanna wait if you + + align:start position:0% +knowledge how much you wanna wait if you + + + align:start position:0% +knowledge how much you wanna wait if you +are in this kind of low dimensional + + align:start position:0% +are in this kind of low dimensional + + + align:start position:0% +are in this kind of low dimensional +situation you might have good ways to + + align:start position:0% +situation you might have good ways to + + + align:start position:0% +situation you might have good ways to +just look inside the data and decide and + + align:start position:0% +just look inside the data and decide and + + + align:start position:0% +just look inside the data and decide and +almost like doing by visual inspection + + align:start position:0% +almost like doing by visual inspection + + + align:start position:0% +almost like doing by visual inspection +otherwise you have to trust some more + + align:start position:0% +otherwise you have to trust some more + + + align:start position:0% +otherwise you have to trust some more +broad principle and it's again back to + + align:start position:0% +broad principle and it's again back to + + + align:start position:0% +broad principle and it's again back to +the problem of learning the + + align:start position:0% +the problem of learning the + + + align:start position:0% +the problem of learning the +representation and deciding how you to + + align:start position:0% +representation and deciding how you to + + + align:start position:0% +representation and deciding how you to +measure distance which are two faces of + + align:start position:0% +measure distance which are two faces of + + + align:start position:0% +measure distance which are two faces of +the same story okay and the other thing + + align:start position:0% +the same story okay and the other thing + + + align:start position:0% +the same story okay and the other thing +you see is that if you start to do these + + align:start position:0% +you see is that if you start to do these + + + align:start position:0% +you see is that if you start to do these +games you might actually add more + + align:start position:0% +games you might actually add more + + + align:start position:0% +games you might actually add more +parameters okay because we start for + + align:start position:0% +parameters okay because we start for + + + align:start position:0% +parameters okay because we start for +nearest-neighbor which was completed + + align:start position:0% +nearest-neighbor which was completed + + + align:start position:0% +nearest-neighbor which was completed +parameter free but it was very unstable + + align:start position:0% +parameter free but it was very unstable + + + align:start position:0% +parameter free but it was very unstable +we are that k we allow ourself to go + + align:start position:0% +we are that k we allow ourself to go + + + align:start position:0% +we are that k we allow ourself to go +from simple to complex from stability to + + align:start position:0% +from simple to complex from stability to + + + align:start position:0% +from simple to complex from stability to +overfitting but we introduced a new + + align:start position:0% +overfitting but we introduced a new + + + align:start position:0% +overfitting but we introduced a new +parameter and so that's not an algorithm + + align:start position:0% +parameter and so that's not an algorithm + + + align:start position:0% +parameter and so that's not an algorithm +anymore it's a half algorithm throughout + + align:start position:0% +anymore it's a half algorithm throughout + + + align:start position:0% +anymore it's a half algorithm throughout +the reason is a parameter free algorithm + + align:start position:0% +the reason is a parameter free algorithm + + + align:start position:0% +the reason is a parameter free algorithm +where I tell you how you choose + + align:start position:0% +where I tell you how you choose + + + align:start position:0% +where I tell you how you choose +everything okay so if you just give you + + align:start position:0% +everything okay so if you just give you + + + align:start position:0% +everything okay so if you just give you +something say there's K yeah well how do + + align:start position:0% +something say there's K yeah well how do + + + align:start position:0% +something say there's K yeah well how do +you choose it okay it's not it's not + + align:start position:0% +you choose it okay it's not it's not + + + align:start position:0% +you choose it okay it's not it's not +something you can use and here I'm + + align:start position:0% +something you can use and here I'm + + + align:start position:0% +something you can use and here I'm +adding Sigma and again you have to + + align:start position:0% +adding Sigma and again you have to + + + align:start position:0% +adding Sigma and again you have to +decide how you use it okay so that's + + align:start position:0% +decide how you use it okay so that's + + + align:start position:0% +decide how you use it okay so that's +what we want to ask in a minute so + + align:start position:0% +what we want to ask in a minute so + + + align:start position:0% +what we want to ask in a minute so +before doing that just a side remark is + + align:start position:0% + + + + align:start position:0% + +we've been looking at vector data okay + + align:start position:0% +we've been looking at vector data okay + + + align:start position:0% +we've been looking at vector data okay +we were basically measuring distance to + + align:start position:0% +we were basically measuring distance to + + + align:start position:0% +we were basically measuring distance to +just the Euclidean norm okay just the + + align:start position:0% +just the Euclidean norm okay just the + + + align:start position:0% +just the Euclidean norm okay just the +usual one or this version like the + + align:start position:0% +usual one or this version like the + + + align:start position:0% +usual one or this version like the +Gaussian kernel that somewhat amplify + + align:start position:0% +Gaussian kernel that somewhat amplify + + + align:start position:0% +Gaussian kernel that somewhat amplify +distances what if you have strings for + + align:start position:0% +distances what if you have strings for + + + align:start position:0% +distances what if you have strings for +example or graphs okay your data turns + + align:start position:0% +example or graphs okay your data turns + + + align:start position:0% +example or graphs okay your data turns +out to be strings and you want to + + align:start position:0% +out to be strings and you want to + + + align:start position:0% +out to be strings and you want to +compare them those are no there isn't + + align:start position:0% +compare them those are no there isn't + + + align:start position:0% +compare them those are no there isn't +you can see even if they're binary + + align:start position:0% +you can see even if they're binary + + + align:start position:0% +you can see even if they're binary +strings there is no linear structure you + + align:start position:0% +strings there is no linear structure you + + + align:start position:0% +strings there is no linear structure you +cannot just sum them up that Euclidean + + align:start position:0% +cannot just sum them up that Euclidean + + + align:start position:0% +cannot just sum them up that Euclidean +distant really make a lot of sense but + + align:start position:0% +distant really make a lot of sense but + + + align:start position:0% +distant really make a lot of sense but +what you can do is that as long as you + + align:start position:0% +what you can do is that as long as you + + + align:start position:0% +what you can do is that as long as you +can define a distance and say this one + + align:start position:0% +can define a distance and say this one + + + align:start position:0% +can define a distance and say this one +would be the simplest one just the + + align:start position:0% +would be the simplest one just the + + + align:start position:0% +would be the simplest one just the +hamming distance just check entries and + + align:start position:0% +hamming distance just check entries and + + + align:start position:0% +hamming distance just check entries and +if they're the same you count one if + + align:start position:0% +if they're the same you count one if + + + align:start position:0% +if they're the same you count one if +they're different you count zero okay + + align:start position:0% +they're different you count zero okay + + + align:start position:0% +they're different you count zero okay +the moment you can define a distance or + + align:start position:0% +the moment you can define a distance or + + + align:start position:0% +the moment you can define a distance or +your data then you can use this kind of + + align:start position:0% +your data then you can use this kind of + + + align:start position:0% +your data then you can use this kind of +techniques and so this technique is + + align:start position:0% +techniques and so this technique is + + + align:start position:0% +techniques and so this technique is +pretty flexible in that cell in that + + align:start position:0% +pretty flexible in that cell in that + + + align:start position:0% +pretty flexible in that cell in that +sense that whenever you can + + align:start position:0% +sense that whenever you can + + + align:start position:0% +sense that whenever you can +if you don't need a vectorial + + align:start position:0% +if you don't need a vectorial + + + align:start position:0% +if you don't need a vectorial +representation you just need a way to + + align:start position:0% +representation you just need a way to + + + align:start position:0% +representation you just need a way to +measure say similarity or distances + + align:start position:0% +measure say similarity or distances + + + align:start position:0% +measure say similarity or distances +between things and then you can use this + + align:start position:0% +between things and then you can use this + + + align:start position:0% +between things and then you can use this +method okay so here I just mentioned it + + align:start position:0% +method okay so here I just mentioned it + + + align:start position:0% +method okay so here I just mentioned it +and that's really most of these classes + + align:start position:0% +and that's really most of these classes + + + align:start position:0% +and that's really most of these classes +going to be about vector data but this + + align:start position:0% +going to be about vector data but this + + + align:start position:0% +going to be about vector data but this +is one point where the moment you have K + + align:start position:0% +is one point where the moment you have K + + + align:start position:0% +is one point where the moment you have K +you can think of this case and ten is + + align:start position:0% +you can think of this case and ten is + + + align:start position:0% +you can think of this case and ten is +the similarity okay similarity is kind + + align:start position:0% +the similarity okay similarity is kind + + + align:start position:0% +the similarity okay similarity is kind +of a constitutes do all two distances so + + align:start position:0% +of a constitutes do all two distances so + + + align:start position:0% +of a constitutes do all two distances so +if it's similarities big is good + + align:start position:0% +if it's similarities big is good + + + align:start position:0% +if it's similarities big is good +distance small is good okay and so here + + align:start position:0% +distance small is good okay and so here + + + align:start position:0% +distance small is good okay and so here +if you have a way to build the K or a + + align:start position:0% +if you have a way to build the K or a + + + align:start position:0% +if you have a way to build the K or a +distance then you're good to go + + align:start position:0% +distance then you're good to go + + + align:start position:0% +distance then you're good to go +and there you we're not going to really + + align:start position:0% +and there you we're not going to really + + + align:start position:0% +and there you we're not going to really +talk about but there's a whole industry + + align:start position:0% +talk about but there's a whole industry + + + align:start position:0% +talk about but there's a whole industry +about how you build this kind of stuff + + align:start position:0% +about how you build this kind of stuff + + + align:start position:0% +about how you build this kind of stuff +so if they give you strings maybe I want + + align:start position:0% +so if they give you strings maybe I want + + + align:start position:0% +so if they give you strings maybe I want +to say that I should not only look at + + align:start position:0% +to say that I should not only look at + + + align:start position:0% +to say that I should not only look at +the entry of a string but also the + + align:start position:0% +the entry of a string but also the + + + align:start position:0% +the entry of a string but also the +nearby entry when I make the score for + + align:start position:0% +nearby entry when I make the score for + + + align:start position:0% +nearby entry when I make the score for +that specific so maybe you know I + + align:start position:0% +that specific so maybe you know I + + + align:start position:0% +that specific so maybe you know I +shifted a value of the string a little + + align:start position:0% +shifted a value of the string a little + + + align:start position:0% +shifted a value of the string a little +bit is not right here is in the next + + align:start position:0% +bit is not right here is in the next + + + align:start position:0% +bit is not right here is in the next +position over so that should count a bit + + align:start position:0% +position over so that should count a bit + + + align:start position:0% +position over so that should count a bit +so I want to do a soft version of this + + align:start position:0% +so I want to do a soft version of this + + + align:start position:0% +so I want to do a soft version of this +okay or maybe have graphs and I want to + + align:start position:0% +okay or maybe have graphs and I want to + + + align:start position:0% +okay or maybe have graphs and I want to +compare graphs and I want to say that if + + align:start position:0% +compare graphs and I want to say that if + + + align:start position:0% +compare graphs and I want to say that if +two graphs are close then I want them to + + align:start position:0% +two graphs are close then I want them to + + + align:start position:0% +two graphs are close then I want them to +have the same label okay how do you do + + align:start position:0% +have the same label okay how do you do + + + align:start position:0% +have the same label okay how do you do +that the next big question is we + + align:start position:0% +that the next big question is we + + + align:start position:0% +that the next big question is we +introduced three parameters they look + + align:start position:0% +introduced three parameters they look + + + align:start position:0% +introduced three parameters they look +really nice because they kind of allowed + + align:start position:0% +really nice because they kind of allowed + + + align:start position:0% +really nice because they kind of allowed +us to get more flexible solutions to the + + align:start position:0% +us to get more flexible solutions to the + + + align:start position:0% +us to get more flexible solutions to the +problem by choosing for example K or the + + align:start position:0% +problem by choosing for example K or the + + + align:start position:0% +problem by choosing for example K or the +Sigma in the Gaussian we can go from + + align:start position:0% +Sigma in the Gaussian we can go from + + + align:start position:0% +Sigma in the Gaussian we can go from +over fittings to stability but then of + + align:start position:0% +over fittings to stability but then of + + + align:start position:0% +over fittings to stability but then of +course we have to choose the parameter + + align:start position:0% +course we have to choose the parameter + + + align:start position:0% +course we have to choose the parameter +and we have to find good ways to choose + + align:start position:0% +and we have to find good ways to choose + + + align:start position:0% +and we have to find good ways to choose +them and so there are a bunch of + + align:start position:0% +them and so there are a bunch of + + + align:start position:0% +them and so there are a bunch of +questions so the first one is well is + + align:start position:0% +questions so the first one is well is + + + align:start position:0% +questions so the first one is well is +there an optimal value at all okay there + + align:start position:0% +there an optimal value at all okay there + + + align:start position:0% +there an optimal value at all okay there +does it exist + + align:start position:0% +does it exist + + + align:start position:0% +does it exist +but if you do exist I can go try to + + align:start position:0% +but if you do exist I can go try to + + + align:start position:0% +but if you do exist I can go try to +estimate it in some way if it doesn't + + align:start position:0% +estimate it in some way if it doesn't + + + align:start position:0% +estimate it in some way if it doesn't +well there's no even make sense edges + + align:start position:0% +well there's no even make sense edges + + + align:start position:0% +well there's no even make sense edges +there's throw a random number I should + + align:start position:0% +there's throw a random number I should + + + align:start position:0% +there's throw a random number I should +take k equal 4 why just because okay so + + align:start position:0% +take k equal 4 why just because okay so + + + align:start position:0% +take k equal 4 why just because okay so +what do you think it exists or not + + align:start position:0% +what do you think it exists or not + + + align:start position:0% +what do you think it exists or not +what is it depends on because that's the + + align:start position:0% +what is it depends on because that's the + + + align:start position:0% +what is it depends on because that's the +next question what is it depends on can + + align:start position:0% +next question what is it depends on can + + + align:start position:0% +next question what is it depends on can +we compute it ok so let's try to guess + + align:start position:0% +we compute it ok so let's try to guess + + + align:start position:0% +we compute it ok so let's try to guess +one minute before we go and check how we + + align:start position:0% +one minute before we go and check how we + + + align:start position:0% +one minute before we go and check how we +do this ok ok + + align:start position:0% + + + + align:start position:0% + +I have to choose it how do I choose it + + align:start position:0% +I have to choose it how do I choose it + + + align:start position:0% +I have to choose it how do I choose it +what does it depend on one thing is the + + align:start position:0% +what does it depend on one thing is the + + + align:start position:0% +what does it depend on one thing is the +size of the data set because what we saw + + align:start position:0% +size of the data set because what we saw + + + align:start position:0% +size of the data set because what we saw +is that as small K seems a good idea + + align:start position:0% +is that as small K seems a good idea + + + align:start position:0% +is that as small K seems a good idea +when you have a lot of data but it seems + + align:start position:0% +when you have a lot of data but it seems + + + align:start position:0% +when you have a lot of data but it seems +like a bad idea when you have a few okay + + align:start position:0% +like a bad idea when you have a few okay + + + align:start position:0% +like a bad idea when you have a few okay +so it should depends it should be + + align:start position:0% +so it should depends it should be + + + align:start position:0% +so it should depends it should be +something that scale with n the number + + align:start position:0% +something that scale with n the number + + + align:start position:0% +something that scale with n the number +of points and probably also the training + + align:start position:0% +of points and probably also the training + + + align:start position:0% +of points and probably also the training +set itself but we want something that + + align:start position:0% +set itself but we want something that + + + align:start position:0% +set itself but we want something that +works for all data set say in + + align:start position:0% +works for all data set say in + + + align:start position:0% +works for all data set say in +expectation so cardinality of the + + align:start position:0% +expectation so cardinality of the + + + align:start position:0% +expectation so cardinality of the +training set is going to be a main + + align:start position:0% +training set is going to be a main + + + align:start position:0% +training set is going to be a main +factor what else the what the smoothness + + align:start position:0% +factor what else the what the smoothness + + + align:start position:0% +factor what else the what the smoothness +of the boundary yeah so what he's saying + + align:start position:0% +of the boundary yeah so what he's saying + + + align:start position:0% +of the boundary yeah so what he's saying +is if my problem looks like this or if + + align:start position:0% +is if my problem looks like this or if + + + align:start position:0% +is if my problem looks like this or if +my problem looks like this it looks like + + align:start position:0% +my problem looks like this it looks like + + + align:start position:0% +my problem looks like this it looks like +K should be different in this case I can + + align:start position:0% +K should be different in this case I can + + + align:start position:0% +K should be different in this case I can +take any arbitrary high K and sorry yeah + + align:start position:0% +take any arbitrary high K and sorry yeah + + + align:start position:0% +take any arbitrary high K and sorry yeah +small K I guess or I it doesn't matter + + align:start position:0% +small K I guess or I it doesn't matter + + + align:start position:0% +small K I guess or I it doesn't matter +because whatever you do you pretty much + + align:start position:0% +because whatever you do you pretty much + + + align:start position:0% +because whatever you do you pretty much +get the good thing but if you start to + + align:start position:0% +get the good thing but if you start to + + + align:start position:0% +get the good thing but if you start to +something like this okay then you want K + + align:start position:0% +something like this okay then you want K + + + align:start position:0% +something like this okay then you want K +is small enough because otherwise you + + align:start position:0% +is small enough because otherwise you + + + align:start position:0% +is small enough because otherwise you +start to blur everything and this is + + align:start position:0% +start to blur everything and this is + + + align:start position:0% +start to blur everything and this is +exactly what he's saying if your problem + + align:start position:0% +exactly what he's saying if your problem + + + align:start position:0% +exactly what he's saying if your problem +is complicated or it's easy okay and at + + align:start position:0% +is complicated or it's easy okay and at + + + align:start position:0% +is complicated or it's easy okay and at +the same time this is related to the + + align:start position:0% +the same time this is related to the + + + align:start position:0% +the same time this is related to the +fact of how much noise you might have in + + align:start position:0% +fact of how much noise you might have in + + + align:start position:0% +fact of how much noise you might have in +the data okay how much you know how much + + align:start position:0% +the data okay how much you know how much + + + align:start position:0% +the data okay how much you know how much +flipping you might have in your data if + + align:start position:0% +flipping you might have in your data if + + + align:start position:0% +flipping you might have in your data if +the problem is hard then you expect to + + align:start position:0% +the problem is hard then you expect to + + + align:start position:0% +the problem is hard then you expect to +need a different K okay so it depends on + + align:start position:0% +need a different K okay so it depends on + + + align:start position:0% +need a different K okay so it depends on +the cardinality of the data and how + + align:start position:0% +the cardinality of the data and how + + + align:start position:0% +the cardinality of the data and how +complicated is the problem how + + align:start position:0% +complicated is the problem how + + + align:start position:0% +complicated is the problem how +complicated is the boundary or much + + align:start position:0% +complicated is the boundary or much + + + align:start position:0% +complicated is the boundary or much +noise I have okay so it turns out that + + align:start position:0% +noise I have okay so it turns out that + + + align:start position:0% +noise I have okay so it turns out that +one thing you can ask is can we prove it + + align:start position:0% +one thing you can ask is can we prove it + + + align:start position:0% +one thing you can ask is can we prove it +okay can we prove a theorem that says + + align:start position:0% +okay can we prove a theorem that says + + + align:start position:0% +okay can we prove a theorem that says +that there is an optimal K and it really + + align:start position:0% +that there is an optimal K and it really + + + align:start position:0% +that there is an optimal K and it really +does depends on this okay + + align:start position:0% +does depends on this okay + + + align:start position:0% +does depends on this okay +on these quantities and it turns out + + align:start position:0% +on these quantities and it turns out + + + align:start position:0% +on these quantities and it turns out +that you can okay of course as always to + + align:start position:0% +that you can okay of course as always to + + + align:start position:0% +that you can okay of course as always to +make a theory to make assumptions and + + align:start position:0% +make a theory to make assumptions and + + + align:start position:0% +make a theory to make assumptions and +you have to work within a model and the + + align:start position:0% +you have to work within a model and the + + + align:start position:0% +you have to work within a model and the +model you wanna work on is the following + + align:start position:0% +model you wanna work on is the following + + + align:start position:0% +model you wanna work on is the following +you're basically saying this is the K + + align:start position:0% +you're basically saying this is the K + + + align:start position:0% +you're basically saying this is the K +nearest neighbors solution so big K here + + align:start position:0% +nearest neighbors solution so big K here + + + align:start position:0% +nearest neighbors solution so big K here +is the number of neighbor and this is + + align:start position:0% +is the number of neighbor and this is + + + align:start position:0% +is the number of neighbor and this is +hat because it depends on the data and + + align:start position:0% +hat because it depends on the data and + + + align:start position:0% +hat because it depends on the data and +what I say here is that I'm just gonna + + align:start position:0% +what I say here is that I'm just gonna + + + align:start position:0% +what I say here is that I'm just gonna +look at square loss error just because + + align:start position:0% +look at square loss error just because + + + align:start position:0% +look at square loss error just because +it's easy and I'm gonna look at the + + align:start position:0% +it's easy and I'm gonna look at the + + + align:start position:0% +it's easy and I'm gonna look at the +regression problem not just this + + align:start position:0% +regression problem not just this + + + align:start position:0% +regression problem not just this +classification and what you do here is + + align:start position:0% +classification and what you do here is + + + align:start position:0% +classification and what you do here is +that you take expectation over all + + align:start position:0% +that you take expectation over all + + + align:start position:0% +that you take expectation over all +possible input output pairs so basically + + align:start position:0% +possible input output pairs so basically + + + align:start position:0% +possible input output pairs so basically +you say when I when I + + align:start position:0% +you say when I when I + + + align:start position:0% +you say when I when I +try to do math I want to see what's + + align:start position:0% +try to do math I want to see what's + + + align:start position:0% +try to do math I want to see what's +ideal and ideally I want the solution + + align:start position:0% +ideal and ideally I want the solution + + + align:start position:0% +ideal and ideally I want the solution +that as well on future points okay so + + align:start position:0% +that as well on future points okay so + + + align:start position:0% +that as well on future points okay so +how do I do that I take the average air + + align:start position:0% +how do I do that I take the average air + + + align:start position:0% +how do I do that I take the average air +over all possible points in the future x + + align:start position:0% +over all possible points in the future x + + + align:start position:0% +over all possible points in the future x +and y so this is the meaning of this + + align:start position:0% +and y so this is the meaning of this + + + align:start position:0% +and y so this is the meaning of this +first expectation that makes sense yes + + align:start position:0% +first expectation that makes sense yes + + + align:start position:0% +first expectation that makes sense yes +No + + align:start position:0% +No + + + align:start position:0% +No +so if I fix Y and X this is the error on + + align:start position:0% +so if I fix Y and X this is the error on + + + align:start position:0% +so if I fix Y and X this is the error on +a specific couple input and output I + + align:start position:0% +a specific couple input and output I + + + align:start position:0% +a specific couple input and output I +give you the input I do FK X and then I + + align:start position:0% +give you the input I do FK X and then I + + + align:start position:0% +give you the input I do FK X and then I +check if it's close or not to why but + + align:start position:0% +check if it's close or not to why but + + + align:start position:0% +check if it's close or not to why but +what I want to do if I want to be + + align:start position:0% +what I want to do if I want to be + + + align:start position:0% +what I want to do if I want to be +theoretically to say okay what I would + + align:start position:0% +theoretically to say okay what I would + + + align:start position:0% +theoretically to say okay what I would +really like to be small is this error + + align:start position:0% +really like to be small is this error + + + align:start position:0% +really like to be small is this error +over all possible points so I take the + + align:start position:0% +over all possible points so I take the + + + align:start position:0% +over all possible points so I take the +expectation not the one on the training + + align:start position:0% +expectation not the one on the training + + + align:start position:0% +expectation not the one on the training +set the one in the future and I take + + align:start position:0% +set the one in the future and I take + + + align:start position:0% +set the one in the future and I take +expectation so that if points are more + + align:start position:0% +expectation so that if points are more + + + align:start position:0% +expectation so that if points are more +likely to be sampled they will count + + align:start position:0% +likely to be sampled they will count + + + align:start position:0% +likely to be sampled they will count +more that points are less likely to be + + align:start position:0% +more that points are less likely to be + + + align:start position:0% +more that points are less likely to be +sampled okay that we haven't got to that + + align:start position:0% +sampled okay that we haven't got to that + + + align:start position:0% +sampled okay that we haven't got to that +one yet okay so e XY is what I just said + + align:start position:0% +one yet okay so e XY is what I just said + + + align:start position:0% +one yet okay so e XY is what I just said +what is yes with the expectation over + + align:start position:0% +what is yes with the expectation over + + + align:start position:0% +what is yes with the expectation over +the training set why do we need that + + align:start position:0% +the training set why do we need that + + + align:start position:0% +the training set why do we need that +well because if you don't put that + + align:start position:0% +well because if you don't put that + + + align:start position:0% +well because if you don't put that +expectation I basically tell you what's + + align:start position:0% +expectation I basically tell you what's + + + align:start position:0% +expectation I basically tell you what's +the good K for this one training set + + align:start position:0% +the good K for this one training set + + + align:start position:0% +the good K for this one training set +here then I give you another training + + align:start position:0% +here then I give you another training + + + align:start position:0% +here then I give you another training +set and I get another one which is in + + align:start position:0% +set and I get another one which is in + + + align:start position:0% +set and I get another one which is in +some sense it's good but it's also bad + + align:start position:0% +some sense it's good but it's also bad + + + align:start position:0% +some sense it's good but it's also bad +because you would like to have like a + + align:start position:0% +because you would like to have like a + + + align:start position:0% +because you would like to have like a +take-home message that we hold for all + + align:start position:0% +take-home message that we hold for all + + + align:start position:0% +take-home message that we hold for all +training set and this is the simplest + + align:start position:0% +training set and this is the simplest + + + align:start position:0% +training set and this is the simplest +you say for the average training set + + align:start position:0% +you say for the average training set + + + align:start position:0% +you say for the average training set +this is how I should choose K that's + + align:start position:0% +this is how I should choose K that's + + + align:start position:0% +this is how I should choose K that's +what we want to do okay so the first + + align:start position:0% +what we want to do okay so the first + + + align:start position:0% +what we want to do okay so the first +expectation is to measure error with + + align:start position:0% +expectation is to measure error with + + + align:start position:0% +expectation is to measure error with +respect to future the second expectation + + align:start position:0% +respect to future the second expectation + + + align:start position:0% +respect to future the second expectation +is to say how I wanna deal with the fact + + align:start position:0% +is to say how I wanna deal with the fact + + + align:start position:0% +is to say how I wanna deal with the fact +that I have just several potential + + align:start position:0% +that I have just several potential + + + align:start position:0% +that I have just several potential +training set appearing + + align:start position:0% +training set appearing + + + align:start position:0% +training set appearing +okay so the next couple of slide this + + align:start position:0% +okay so the next couple of slide this + + + align:start position:0% +okay so the next couple of slide this +red dot means that there are + + align:start position:0% +red dot means that there are + + + align:start position:0% +red dot means that there are +computations okay and so I want to do + + align:start position:0% +computations okay and so I want to do + + + align:start position:0% +computations okay and so I want to do +them quickly and the important thing of + + align:start position:0% +them quickly and the important thing of + + + align:start position:0% +them quickly and the important thing of +this bit is it's an exercise okay so + + align:start position:0% +this bit is it's an exercise okay so + + + align:start position:0% +this bit is it's an exercise okay so +this is an exercise of stats zero okay + + align:start position:0% +this is an exercise of stats zero okay + + + align:start position:0% +this is an exercise of stats zero okay +so I don't we don't want to spend time + + align:start position:0% +so I don't we don't want to spend time + + + align:start position:0% +so I don't we don't want to spend time +doing that the important thing is gonna + + align:start position:0% +doing that the important thing is gonna + + + align:start position:0% +doing that the important thing is gonna +be the concept of price so I'm gonna be + + align:start position:0% +be the concept of price so I'm gonna be + + + align:start position:0% +be the concept of price so I'm gonna be +go ab it quickly through it so you start + + align:start position:0% +go ab it quickly through it so you start + + + align:start position:0% +go ab it quickly through it so you start +from this and you would like to + + align:start position:0% +from this and you would like to + + + align:start position:0% +from this and you would like to +understand that if there exists so this + + align:start position:0% +understand that if there exists so this + + + align:start position:0% +understand that if there exists so this +is the quantity you would like to make + + align:start position:0% +is the quantity you would like to make + + + align:start position:0% +is the quantity you would like to make +small ideally okay you all never x-axis + + align:start position:0% +small ideally okay you all never x-axis + + + align:start position:0% +small ideally okay you all never x-axis +to this but ideally + + align:start position:0% +to this but ideally + + + align:start position:0% +to this but ideally +in the optimal scenario you want K to + + align:start position:0% +in the optimal scenario you want K to + + + align:start position:0% +in the optimal scenario you want K to +make this small okay now the problem is + + align:start position:0% +make this small okay now the problem is + + + align:start position:0% +make this small okay now the problem is +that you you want to stand too much + + align:start position:0% +that you you want to stand too much + + + align:start position:0% +that you you want to stand too much +matically study this minimization + + align:start position:0% +matically study this minimization + + + align:start position:0% +matically study this minimization +problem but it's not easy because how do + + align:start position:0% +problem but it's not easy because how do + + + align:start position:0% +problem but it's not easy because how do +you do this okay + + align:start position:0% +you do this okay + + + align:start position:0% +you do this okay +the dependence of this function on K is + + align:start position:0% +the dependence of this function on K is + + + align:start position:0% +the dependence of this function on K is +complicated is that equation we had + + align:start position:0% +complicated is that equation we had + + + align:start position:0% +complicated is that equation we had +before right so you cannot just take the + + align:start position:0% +before right so you cannot just take the + + + align:start position:0% +before right so you cannot just take the +Rif didn't set it equal to zero let's + + align:start position:0% +Rif didn't set it equal to zero let's + + + align:start position:0% +Rif didn't set it equal to zero let's +keep on going a bit to this so what we + + align:start position:0% +keep on going a bit to this so what we + + + align:start position:0% +keep on going a bit to this so what we +were at is this is the quantity we like + + align:start position:0% +were at is this is the quantity we like + + + align:start position:0% +were at is this is the quantity we like +to make small I would like to choose K + + align:start position:0% +to make small I would like to choose K + + + align:start position:0% +to make small I would like to choose K +so that they can make this small I want + + align:start position:0% +so that they can make this small I want + + + align:start position:0% +so that they can make this small I want +to study this from a mathematical point + + align:start position:0% +to study this from a mathematical point + + + align:start position:0% +to study this from a mathematical point +of view but I cannot just use what you + + align:start position:0% +of view but I cannot just use what you + + + align:start position:0% +of view but I cannot just use what you +do in calculus which is taking the + + align:start position:0% +do in calculus which is taking the + + + align:start position:0% +do in calculus which is taking the +derivative and set it equal to zero + + align:start position:0% +derivative and set it equal to zero + + + align:start position:0% +derivative and set it equal to zero +because the dependence of these two K + + align:start position:0% +because the dependence of these two K + + + align:start position:0% +because the dependence of these two K +which is my variable it's complicated + + align:start position:0% +which is my variable it's complicated + + + align:start position:0% +which is my variable it's complicated +okay so we go a bit of a round weight + + align:start position:0% +okay so we go a bit of a round weight + + + align:start position:0% +okay so we go a bit of a round weight +would turn out to be pretty Universal + + align:start position:0% +would turn out to be pretty Universal + + + align:start position:0% +would turn out to be pretty Universal +and this is what we're going to do first + + align:start position:0% +and this is what we're going to do first + + + align:start position:0% +and this is what we're going to do first +of all we assume a model for our data + + align:start position:0% +of all we assume a model for our data + + + align:start position:0% +of all we assume a model for our data +and this is just for the sake of + + align:start position:0% +and this is just for the sake of + + + align:start position:0% +and this is just for the sake of +simplicity okay I can use this much more + + align:start position:0% +simplicity okay I can use this much more + + + align:start position:0% +simplicity okay I can use this much more +general model but this is the model I'm + + align:start position:0% +general model but this is the model I'm + + + align:start position:0% +general model but this is the model I'm +gonna say that my Y are just some fixed + + align:start position:0% +gonna say that my Y are just some fixed + + + align:start position:0% +gonna say that my Y are just some fixed +function X star plus some noise okay and + + align:start position:0% +function X star plus some noise okay and + + + align:start position:0% +function X star plus some noise okay and +the noise is zero mean and variance + + align:start position:0% +the noise is zero mean and variance + + + align:start position:0% +the noise is zero mean and variance +Sigma square for all entries okay this + + align:start position:0% +Sigma square for all entries okay this + + + align:start position:0% +Sigma square for all entries okay this +is the simplest model okay is a Gaussian + + align:start position:0% +is the simplest model okay is a Gaussian + + + align:start position:0% +is the simplest model okay is a Gaussian +regression model then + + align:start position:0% + + + + align:start position:0% + +okay so one thing I'm doing but this is + + align:start position:0% +okay so one thing I'm doing but this is + + + align:start position:0% +okay so one thing I'm doing but this is +like a trick and you can really forget + + align:start position:0% +like a trick and you can really forget + + + align:start position:0% +like a trick and you can really forget +it but you just make life much easier is + + align:start position:0% +it but you just make life much easier is + + + align:start position:0% +it but you just make life much easier is +that I take this petition over X Y and I + + align:start position:0% +that I take this petition over X Y and I + + + align:start position:0% +that I take this petition over X Y and I +condition here okay the reason why you + + align:start position:0% +condition here okay the reason why you + + + align:start position:0% +condition here okay the reason why you +do this is just to make the math a bit + + align:start position:0% +do this is just to make the math a bit + + + align:start position:0% +do this is just to make the math a bit +easier because basically now if you put + + align:start position:0% +easier because basically now if you put + + + align:start position:0% +easier because basically now if you put +this expectation out and you look just + + align:start position:0% +this expectation out and you look just + + + align:start position:0% +this expectation out and you look just +at this quantity you're looking at + + align:start position:0% +at this quantity you're looking at + + + align:start position:0% +at this quantity you're looking at +everything for fixed X and this just + + align:start position:0% +everything for fixed X and this just + + + align:start position:0% +everything for fixed X and this just +become a real number okay not the + + align:start position:0% +become a real number okay not the + + + align:start position:0% +become a real number okay not the +function anymore + + align:start position:0% +function anymore + + + align:start position:0% +function anymore +so you can use normal calculus you have + + align:start position:0% +so you can use normal calculus you have + + + align:start position:0% +so you can use normal calculus you have +a functional a real valued function I + + align:start position:0% +a functional a real valued function I + + + align:start position:0% +a functional a real valued function I +can just use the usual stuff okay again + + align:start position:0% +can just use the usual stuff okay again + + + align:start position:0% +can just use the usual stuff okay again +I'm going to be quickly over this + + align:start position:0% +I'm going to be quickly over this + + + align:start position:0% +I'm going to be quickly over this +because it doesn't really mean that so + + align:start position:0% +because it doesn't really mean that so + + + align:start position:0% +because it doesn't really mean that so +this is ingredient one this is + + align:start position:0% +this is ingredient one this is + + + align:start position:0% +this is ingredient one this is +observation - was there bacon three is + + align:start position:0% +observation - was there bacon three is + + + align:start position:0% +observation - was there bacon three is +that you need to introduce a object + + align:start position:0% +that you need to introduce a object + + + align:start position:0% +that you need to introduce a object +between the solution you get in practice + + align:start position:0% +between the solution you get in practice + + + align:start position:0% +between the solution you get in practice +and this ideal function what is this is + + align:start position:0% +and this ideal function what is this is + + + align:start position:0% +and this ideal function what is this is +this kind of what is called is the + + align:start position:0% +this kind of what is called is the + + + align:start position:0% +this kind of what is called is the +expectation of my algorithm what you do + + align:start position:0% +expectation of my algorithm what you do + + + align:start position:0% +expectation of my algorithm what you do +is that in my algorithm what I do here + + align:start position:0% +is that in my algorithm what I do here + + + align:start position:0% +is that in my algorithm what I do here +is that I put Y I okay just the label of + + align:start position:0% +is that I put Y I okay just the label of + + + align:start position:0% +is that I put Y I okay just the label of +my training set and the label are noisy + + align:start position:0% +my training set and the label are noisy + + + align:start position:0% +my training set and the label are noisy +but this is an ideal object where you + + align:start position:0% +but this is an ideal object where you + + + align:start position:0% +but this is an ideal object where you +put the true function itself and you + + align:start position:0% +put the true function itself and you + + + align:start position:0% +put the true function itself and you +just average the value of the true + + align:start position:0% +just average the value of the true + + + align:start position:0% +just average the value of the true +function if you why do I use this + + align:start position:0% +function if you why do I use this + + + align:start position:0% +function if you why do I use this +because I want to get something which is + + align:start position:0% +because I want to get something which is + + + align:start position:0% +because I want to get something which is +in between this F star and this as hell + + align:start position:0% +in between this F star and this as hell + + + align:start position:0% +in between this F star and this as hell +so if you put K big enough so if you + + align:start position:0% +so if you put K big enough so if you + + + align:start position:0% +so if you put K big enough so if you +have enough point this is gonna be sorry + + align:start position:0% +have enough point this is gonna be sorry + + + align:start position:0% +have enough point this is gonna be sorry +if you take K small enough so this is + + align:start position:0% +if you take K small enough so this is + + + align:start position:0% +if you take K small enough so this is +closer to F star than my asset okay + + align:start position:0% +closer to F star than my asset okay + + + align:start position:0% +closer to F star than my asset okay +because you get the non noisy data and + + align:start position:0% +because you get the non noisy data and + + + align:start position:0% +because you get the non noisy data and +what they want to do what I want to do + + align:start position:0% +what they want to do what I want to do + + + align:start position:0% +what they want to do what I want to do +is that I want to plug it in the middle + + align:start position:0% +is that I want to plug it in the middle + + + align:start position:0% +is that I want to plug it in the middle +and split this error in two and this is + + align:start position:0% +and split this error in two and this is + + + align:start position:0% +and split this error in two and this is +what I do okay if you do this you can + + align:start position:0% +what I do okay if you do this you can + + + align:start position:0% +what I do okay if you do this you can +check that you have a square here you + + align:start position:0% +check that you have a square here you + + + align:start position:0% +check that you have a square here you +get two terms one simplifies because of + + align:start position:0% +get two terms one simplifies because of + + + align:start position:0% +get two terms one simplifies because of +this assumption on the noise and you get + + align:start position:0% +this assumption on the noise and you get + + + align:start position:0% +this assumption on the noise and you get +these two terms okay and the important + + align:start position:0% +these two terms okay and the important + + + align:start position:0% +these two terms okay and the important +thing is these two terms are one is the + + align:start position:0% +thing is these two terms are one is the + + + align:start position:0% +thing is these two terms are one is the +comparison between my algorithm and its + + align:start position:0% +comparison between my algorithm and its + + + align:start position:0% +comparison between my algorithm and its +expectation so that's is that what we + + align:start position:0% +expectation so that's is that what we + + + align:start position:0% +expectation so that's is that what we +called a variance okay and one is the + + align:start position:0% +called a variance okay and one is the + + + align:start position:0% +called a variance okay and one is the +comparison between the value of the true + + align:start position:0% +comparison between the value of the true + + + align:start position:0% +comparison between the value of the true +function here and the value of this + + align:start position:0% +function here and the value of this + + + align:start position:0% +function here and the value of this +other function sorry this should + + align:start position:0% +other function sorry this should + + + align:start position:0% +other function sorry this should +oh yeah this is the expectation which is + + align:start position:0% +oh yeah this is the expectation which is + + + align:start position:0% +oh yeah this is the expectation which is +my ideal version of my algorithm the one + + align:start position:0% +my ideal version of my algorithm the one + + + align:start position:0% +my ideal version of my algorithm the one +that has access to the noiseless labels + + align:start position:0% +that has access to the noiseless labels + + + align:start position:0% +that has access to the noiseless labels +okay it's what you call a bias it's + + align:start position:0% +okay it's what you call a bias it's + + + align:start position:0% +okay it's what you call a bias it's +basically because instead of using the + + align:start position:0% +basically because instead of using the + + + align:start position:0% +basically because instead of using the +exact value of the function you blur it + + align:start position:0% +exact value of the function you blur it + + + align:start position:0% +exact value of the function you blur it +a bit by averaging out okay you see here + + align:start position:0% +a bit by averaging out okay you see here + + + align:start position:0% +a bit by averaging out okay you see here +instead of using the value of the + + align:start position:0% +instead of using the value of the + + + align:start position:0% +instead of using the value of the +function u average out a few nearby + + align:start position:0% +function u average out a few nearby + + + align:start position:0% +function u average out a few nearby +value so you're you're making it a bit + + align:start position:0% +value so you're you're making it a bit + + + align:start position:0% +value so you're you're making it a bit +dirtier the question now is how would + + align:start position:0% +dirtier the question now is how would + + + align:start position:0% +dirtier the question now is how would +these two quantities depend on K how + + align:start position:0% +these two quantities depend on K how + + + align:start position:0% +these two quantities depend on K how +this quantity depends on K and how this + + align:start position:0% +this quantity depends on K and how this + + + align:start position:0% +this quantity depends on K and how this +quantity depends on K okay and then by + + align:start position:0% +quantity depends on K okay and then by + + + align:start position:0% +quantity depends on K okay and then by +putting this together we'll see that we + + align:start position:0% +putting this together we'll see that we + + + align:start position:0% +putting this together we'll see that we +have a certain behavior of this and a + + align:start position:0% +have a certain behavior of this and a + + + align:start position:0% +have a certain behavior of this and a +certain behavior of this and then we + + align:start position:0% +certain behavior of this and then we + + + align:start position:0% +certain behavior of this and then we +balancing this out will get what the + + align:start position:0% +balancing this out will get what the + + + align:start position:0% +balancing this out will get what the +optimal value looked like and this is + + align:start position:0% +optimal value looked like and this is + + + align:start position:0% +optimal value looked like and this is +going to be all useless from so this is + + align:start position:0% +going to be all useless from so this is + + + align:start position:0% +going to be all useless from so this is +going to be interesting from a + + align:start position:0% +going to be interesting from a + + + align:start position:0% +going to be interesting from a +conceptual perspective we're going to + + align:start position:0% +conceptual perspective we're going to + + + align:start position:0% +conceptual perspective we're going to +learn something but we'll still have to + + align:start position:0% +learn something but we'll still have to + + + align:start position:0% +learn something but we'll still have to +do something practical because nothing + + align:start position:0% +do something practical because nothing + + + align:start position:0% +do something practical because nothing +of these you can measure in practice + + align:start position:0% +of these you can measure in practice + + + align:start position:0% +of these you can measure in practice +okay so you the next question will be + + align:start position:0% +okay so you the next question will be + + + align:start position:0% +okay so you the next question will be +holding now that we know that it exists + + align:start position:0% +holding now that we know that it exists + + + align:start position:0% +holding now that we know that it exists +and it depends on this stuff how can we + + align:start position:0% +and it depends on this stuff how can we + + + align:start position:0% +and it depends on this stuff how can we +actually approximate it in practice and + + align:start position:0% +actually approximate it in practice and + + + align:start position:0% +actually approximate it in practice and +cross-validation is going to pop out at + + align:start position:0% +cross-validation is going to pop out at + + + align:start position:0% +cross-validation is going to pop out at +the window okay but is it about the + + align:start position:0% +the window okay but is it about the + + + align:start position:0% +the window okay but is it about the +theory that shows you that this would + + align:start position:0% +theory that shows you that this would + + + align:start position:0% +theory that shows you that this would +help proving a theory that shows that + + align:start position:0% +help proving a theory that shows that + + + align:start position:0% +help proving a theory that shows that +cross-validation is a good idea + + align:start position:0% +cross-validation is a good idea + + + align:start position:0% +cross-validation is a good idea +in a precise sense take-home messages by + + align:start position:0% +in a precise sense take-home messages by + + + align:start position:0% +in a precise sense take-home messages by +making this model and using this as an + + align:start position:0% +making this model and using this as an + + + align:start position:0% +making this model and using this as an +intermediate object you split the error + + align:start position:0% +intermediate object you split the error + + + align:start position:0% +intermediate object you split the error +in two and you start to be able to study + + align:start position:0% +in two and you start to be able to study + + + align:start position:0% +in two and you start to be able to study +and what you get is basically the + + align:start position:0% +and what you get is basically the + + + align:start position:0% +and what you get is basically the +following this term by basically using + + align:start position:0% +following this term by basically using + + + align:start position:0% +following this term by basically using +independence of what we assume that the + + align:start position:0% +independence of what we assume that the + + + align:start position:0% +independence of what we assume that the +data I didn't say that but that's + + align:start position:0% +data I didn't say that but that's + + + align:start position:0% +data I didn't say that but that's +important we assume that the data are + + align:start position:0% +important we assume that the data are + + + align:start position:0% +important we assume that the data are +independent with each other okay and by + + align:start position:0% +independent with each other okay and by + + + align:start position:0% +independent with each other okay and by +using that you get these results right + + align:start position:0% +using that you get these results right + + + align:start position:0% +using that you get these results right +away essentially using the fact that the + + align:start position:0% +away essentially using the fact that the + + + align:start position:0% +away essentially using the fact that the +variance of sum of independent variables + + align:start position:0% +variance of sum of independent variables + + + align:start position:0% +variance of sum of independent variables +the sum of the variances you get these + + align:start position:0% +the sum of the variances you get these + + + align:start position:0% +the sum of the variances you get these +results in one line okay and basically + + align:start position:0% +results in one line okay and basically + + + align:start position:0% +results in one line okay and basically +what this shows is that if K gets big so + + align:start position:0% +what this shows is that if K gets big so + + + align:start position:0% +what this shows is that if K gets big so +variance is another word for the + + align:start position:0% +variance is another word for the + + + align:start position:0% +variance is another word for the +stability okay so if if you have a big + + align:start position:0% +stability okay so if if you have a big + + + align:start position:0% +stability okay so if if you have a big +variance things will vary a lot it will + + align:start position:0% +variance things will vary a lot it will + + + align:start position:0% +variance things will vary a lot it will +be unstable so what you see here is + + align:start position:0% +be unstable so what you see here is + + + align:start position:0% +be unstable so what you see here is +exactly what we observe in the in the + + align:start position:0% +exactly what we observe in the in the + + + align:start position:0% +exactly what we observe in the in the +plots before if K was big things were + + align:start position:0% +plots before if K was big things were + + + align:start position:0% +plots before if K was big things were +not changing as much if K was more + + align:start position:0% +not changing as much if K was more + + + align:start position:0% +not changing as much if K was more +things were changing a lot okay and this + + align:start position:0% +things were changing a lot okay and this + + + align:start position:0% +things were changing a lot okay and this +is the one equation that shows you that + + align:start position:0% +is the one equation that shows you that + + + align:start position:0% +is the one equation that shows you that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and if you just look at that you would + + align:start position:0% +and if you just look at that you would + + + align:start position:0% +and if you just look at that you would +just tell you the biggest the better big + + align:start position:0% +just tell you the biggest the better big + + + align:start position:0% +just tell you the biggest the better big +respect to what to the noise okay + + align:start position:0% +respect to what to the noise okay + + + align:start position:0% +respect to what to the noise okay +there's a lot of noise I should make it + + align:start position:0% +there's a lot of noise I should make it + + + align:start position:0% +there's a lot of noise I should make it +bigger should a small noise I can make + + align:start position:0% +bigger should a small noise I can make + + + align:start position:0% +bigger should a small noise I can make +it smaller but the point is that we saw + + align:start position:0% +it smaller but the point is that we saw + + + align:start position:0% +it smaller but the point is that we saw +before is that the problem putting K + + align:start position:0% +before is that the problem putting K + + + align:start position:0% +before is that the problem putting K +large was that we were forgetting about + + align:start position:0% +large was that we were forgetting about + + + align:start position:0% +large was that we were forgetting about +the problem we're just getting with + + align:start position:0% +the problem we're just getting with + + + align:start position:0% +the problem we're just getting with +something were very stable but could be + + align:start position:0% +something were very stable but could be + + + align:start position:0% +something were very stable but could be +potentially very bad if my function was + + align:start position:0% +potentially very bad if my function was + + + align:start position:0% +potentially very bad if my function was +not that simple okay this is a bit + + align:start position:0% +not that simple okay this is a bit + + + align:start position:0% +not that simple okay this is a bit +harder to study mathematically okay this + + align:start position:0% +harder to study mathematically okay this + + + align:start position:0% +harder to study mathematically okay this +is the calculation that I show you + + align:start position:0% +is the calculation that I show you + + + align:start position:0% +is the calculation that I show you +because you can do it yourself in like + + align:start position:0% +because you can do it yourself in like + + + align:start position:0% +because you can do it yourself in like +20 minutes + + align:start position:0% +20 minutes + + + align:start position:0% +20 minutes +okay or less this one it takes a bit + + align:start position:0% +okay or less this one it takes a bit + + + align:start position:0% +okay or less this one it takes a bit +more but we can get the hunch on how it + + align:start position:0% +more but we can get the hunch on how it + + + align:start position:0% +more but we can get the hunch on how it +looks like and the basic idea is what we + + align:start position:0% +looks like and the basic idea is what we + + + align:start position:0% +looks like and the basic idea is what we +already said if K is small in some sense + + align:start position:0% +already said if K is small in some sense + + + align:start position:0% +already said if K is small in some sense +weird and the points are close enough + + align:start position:0% +weird and the points are close enough + + + align:start position:0% +weird and the points are close enough +instead of F star X we are taking an F + + align:start position:0% +instead of F star X we are taking an F + + + align:start position:0% +instead of F star X we are taking an F +star X K X I and the I is close enough + + align:start position:0% +star X K X I and the I is close enough + + + align:start position:0% +star X K X I and the I is close enough +okay now if we start to put K bigger we + + align:start position:0% +okay now if we start to put K bigger we + + + align:start position:0% +okay now if we start to put K bigger we +start to blur that prediction by looking + + align:start position:0% +start to blur that prediction by looking + + + align:start position:0% +start to blur that prediction by looking +at many nearby points and but here there + + align:start position:0% +at many nearby points and but here there + + + align:start position:0% +at many nearby points and but here there +is no noise okay so that sounds like a + + align:start position:0% +is no noise okay so that sounds like a + + + align:start position:0% +is no noise okay so that sounds like a +bad idea so they we expect that error in + + align:start position:0% +bad idea so they we expect that error in + + + align:start position:0% +bad idea so they we expect that error in +that case to be either increasing or at + + align:start position:0% +that case to be either increasing or at + + + align:start position:0% +that case to be either increasing or at +least flat with respect to K so when we + + align:start position:0% +least flat with respect to K so when we + + + align:start position:0% +least flat with respect to K so when we +take K larger we're blurring this + + align:start position:0% +take K larger we're blurring this + + + align:start position:0% +take K larger we're blurring this +prediction and potentially make it far + + align:start position:0% +prediction and potentially make it far + + + align:start position:0% +prediction and potentially make it far +away from the true one okay and you can + + align:start position:0% +away from the true one okay and you can + + + align:start position:0% +away from the true one okay and you can +make this statement precise you can do + + align:start position:0% +make this statement precise you can do + + + align:start position:0% +make this statement precise you can do +you can prove it okay and what you if + + align:start position:0% +you can prove it okay and what you if + + + align:start position:0% +you can prove it okay and what you if +you will prove is basically that you + + align:start position:0% +you will prove is basically that you + + + align:start position:0% +you will prove is basically that you +have you have linear dependence so the + + align:start position:0% +have you have linear dependence so the + + + align:start position:0% +have you have linear dependence so the +error here is linearly increasing or + + align:start position:0% +error here is linearly increasing or + + + align:start position:0% +error here is linearly increasing or +polynomial increase in fact I don't + + align:start position:0% +polynomial increase in fact I don't + + + align:start position:0% +polynomial increase in fact I don't +remember with respect to K okay so the + + align:start position:0% +remember with respect to K okay so the + + + align:start position:0% +remember with respect to K okay so the +reason why I'm showing you this is + + align:start position:0% +reason why I'm showing you this is + + + align:start position:0% +reason why I'm showing you this is +skipping all these details just gave you + + align:start position:0% +skipping all these details just gave you + + + align:start position:0% +skipping all these details just gave you +a feeling of the kind of competition + + align:start position:0% +a feeling of the kind of competition + + + align:start position:0% +a feeling of the kind of competition +that answer the question is there is if + + align:start position:0% +that answer the question is there is if + + + align:start position:0% +that answer the question is there is if +there is an optimal value and what does + + align:start position:0% +there is an optimal value and what does + + + align:start position:0% +there is an optimal value and what does +it depends on and then at these points + + align:start position:0% +it depends on and then at these points + + + align:start position:0% +it depends on and then at these points +once you get these you start to see this + + align:start position:0% +once you get these you start to see this + + + align:start position:0% +once you get these you start to see this +kind of plot and typically here I put + + align:start position:0% +kind of plot and typically here I put + + + align:start position:0% +kind of plot and typically here I put +them the wrong way but here you + + align:start position:0% +them the wrong way but here you + + + align:start position:0% +them the wrong way but here you +basically say I have this one function I + + align:start position:0% +basically say I have this one function I + + + align:start position:0% +basically say I have this one function I +wanted to study which is the sum of two + + align:start position:0% +wanted to study which is the sum of two + + + align:start position:0% +wanted to study which is the sum of two +functions + + align:start position:0% +functions + + + align:start position:0% +functions +I have this and have this okay + + align:start position:0% +I have this and have this okay + + + align:start position:0% +I have this and have this okay +and now to study the minimum I'm + + align:start position:0% +and now to study the minimum I'm + + + align:start position:0% +and now to study the minimum I'm +basically gonna sum them up and see + + align:start position:0% +basically gonna sum them up and see + + + align:start position:0% +basically gonna sum them up and see +what's the optimal value to optimize + + align:start position:0% +what's the optimal value to optimize + + + align:start position:0% +what's the optimal value to optimize +these two and the K that optimize this + + align:start position:0% +these two and the K that optimize this + + + align:start position:0% +these two and the K that optimize this +is exactly the optimal K and you see + + align:start position:0% +is exactly the optimal K and you see + + + align:start position:0% +is exactly the optimal K and you see +that the optimal K will behave as you + + align:start position:0% +that the optimal K will behave as you + + + align:start position:0% +that the optimal K will behave as you +expected okay be forced so here one + + align:start position:0% +expected okay be forced so here one + + + align:start position:0% +expected okay be forced so here one +ingredient is missing and it's just + + align:start position:0% +ingredient is missing and it's just + + + align:start position:0% +ingredient is missing and it's just +missing because I didn't put it in which + + align:start position:0% +missing because I didn't put it in which + + + align:start position:0% +missing because I didn't put it in which +is the number of points okay it's just + + align:start position:0% +is the number of points okay it's just + + + align:start position:0% +is the number of points okay it's just +because I didn't realize things okay it + + align:start position:0% +because I didn't realize things okay it + + + align:start position:0% +because I didn't realize things okay it +should be a 1 over n here is the after I + + align:start position:0% +should be a 1 over n here is the after I + + + align:start position:0% +should be a 1 over n here is the after I +didn't realize okay so but you announced + + align:start position:0% +didn't realize okay so but you announced + + + align:start position:0% +didn't realize okay so but you announced +it and it's good because it's true there + + align:start position:0% +it and it's good because it's true there + + + align:start position:0% +it and it's good because it's true there +should be one other end there but the + + align:start position:0% +should be one other end there but the + + + align:start position:0% +should be one other end there but the +rest is what we expected okay in some + + align:start position:0% +rest is what we expected okay in some + + + align:start position:0% +rest is what we expected okay in some +sense what we expect is that if my + + align:start position:0% +sense what we expect is that if my + + + align:start position:0% +sense what we expect is that if my +problem is complicated + + align:start position:0% +problem is complicated + + + align:start position:0% +problem is complicated +I need the smaller K if there is a lot + + align:start position:0% +I need the smaller K if there is a lot + + + align:start position:0% +I need the smaller K if there is a lot +of noise and in smaller I need a bigger + + align:start position:0% +of noise and in smaller I need a bigger + + + align:start position:0% +of noise and in smaller I need a bigger +K and depending on the number of points + + align:start position:0% +K and depending on the number of points + + + align:start position:0% +K and depending on the number of points +which would be in denominator here I can + + align:start position:0% +which would be in denominator here I can + + + align:start position:0% +which would be in denominator here I can +make them more or bigger or larger okay + + align:start position:0% +make them more or bigger or larger okay + + + align:start position:0% +make them more or bigger or larger okay +okay this plot is fundamental because it + + align:start position:0% +okay this plot is fundamental because it + + + align:start position:0% +okay this plot is fundamental because it +shows some property which is inheriting + + align:start position:0% +shows some property which is inheriting + + + align:start position:0% +shows some property which is inheriting +the problem and is like the theorem that + + align:start position:0% +the problem and is like the theorem that + + + align:start position:0% +the problem and is like the theorem that +some what is behind the intuition I've + + align:start position:0% +some what is behind the intuition I've + + + align:start position:0% +some what is behind the intuition I've +been saying you know repeating over and + + align:start position:0% +been saying you know repeating over and + + + align:start position:0% +been saying you know repeating over and +over which is this intuition that you + + align:start position:0% +over which is this intuition that you + + + align:start position:0% +over which is this intuition that you +cannot trust the data too much and there + + align:start position:0% +cannot trust the data too much and there + + + align:start position:0% +cannot trust the data too much and there +is the optimal amount of trust you can + + align:start position:0% +is the optimal amount of trust you can + + + align:start position:0% +is the optimal amount of trust you can +offer your data based on certain + + align:start position:0% +offer your data based on certain + + + align:start position:0% +offer your data based on certain +assumption okay and in our case the + + align:start position:0% +assumption okay and in our case the + + + align:start position:0% +assumption okay and in our case the +assumption where this kind of model so + + align:start position:0% +assumption where this kind of model so + + + align:start position:0% +assumption where this kind of model so +these grounds this little calculation I + + align:start position:0% +these grounds this little calculation I + + + align:start position:0% +these grounds this little calculation I +show you quickly grounds this intuition + + align:start position:0% +show you quickly grounds this intuition + + + align:start position:0% +show you quickly grounds this intuition +into a mathematical argument okay all + + align:start position:0% +into a mathematical argument okay all + + + align:start position:0% +into a mathematical argument okay all +right so we spent quite a bit of time on + + align:start position:0% +right so we spent quite a bit of time on + + + align:start position:0% +right so we spent quite a bit of time on +this in some sense this is a create from + + align:start position:0% +this in some sense this is a create from + + + align:start position:0% +this in some sense this is a create from +a conceptual point of view this is a + + align:start position:0% +a conceptual point of view this is a + + + align:start position:0% +a conceptual point of view this is a +critical idea okay because it's behind + + align:start position:0% +critical idea okay because it's behind + + + align:start position:0% +critical idea okay because it's behind +pretty much everything this idea of how + + align:start position:0% +pretty much everything this idea of how + + + align:start position:0% +pretty much everything this idea of how +much you can trust or not the data of + + align:start position:0% +much you can trust or not the data of + + + align:start position:0% +much you can trust or not the data of +course here as we said this is + + align:start position:0% +course here as we said this is + + + align:start position:0% +course here as we said this is +informative hopefully but you don't + + align:start position:0% +informative hopefully but you don't + + + align:start position:0% +informative hopefully but you don't +cannot really choose this K because you + + align:start position:0% +cannot really choose this K because you + + + align:start position:0% +cannot really choose this K because you +would need to know the noise but + + align:start position:0% +would need to know the noise but + + + align:start position:0% +would need to know the noise but +especially to know how to estimate this + + align:start position:0% +especially to know how to estimate this + + + align:start position:0% +especially to know how to estimate this +in order to minimize this quantity so in + + align:start position:0% +in order to minimize this quantity so in + + + align:start position:0% +in order to minimize this quantity so in +practice what you can show is you can + + align:start position:0% +practice what you can show is you can + + + align:start position:0% +practice what you can show is you can +use what is called cross-validation and + + align:start position:0% +use what is called cross-validation and + + + align:start position:0% +use what is called cross-validation and +in fact correlation is one one of a few + + align:start position:0% +in fact correlation is one one of a few + + + align:start position:0% +in fact correlation is one one of a few +other techniques you can use and the + + align:start position:0% +other techniques you can use and the + + + align:start position:0% +other techniques you can use and the +idea is that you don't have access but + + align:start position:0% +idea is that you don't have access but + + + align:start position:0% +idea is that you don't have access but +you can show that if you take a bunch of + + align:start position:0% +you can show that if you take a bunch of + + + align:start position:0% +you can show that if you take a bunch of +data points okay you split them in to + + align:start position:0% +data points okay you split them in to + + + align:start position:0% +data points okay you split them in to +use half for the training as usual is + + align:start position:0% +use half for the training as usual is + + + align:start position:0% +use half for the training as usual is +done and use the other half as a proxy + + align:start position:0% +done and use the other half as a proxy + + + align:start position:0% +done and use the other half as a proxy +for this future data then by minimizing + + align:start position:0% +for this future data then by minimizing + + + align:start position:0% +for this future data then by minimizing +the K taking the kid that minimize the + + align:start position:0% +the K taking the kid that minimize the + + + align:start position:0% +the K taking the kid that minimize the +error on this so-called holdout set then + + align:start position:0% +error on this so-called holdout set then + + + align:start position:0% +error on this so-called holdout set then +you can prove as good as if you could + + align:start position:0% +you can prove as good as if you could + + + align:start position:0% +you can prove as good as if you could +have access to this okay and it's + + align:start position:0% +have access to this okay and it's + + + align:start position:0% +have access to this okay and it's +actually very easy to prove you can show + + align:start position:0% +actually very easy to prove you can show + + + align:start position:0% +actually very easy to prove you can show +that if you just split in two okay and + + align:start position:0% +that if you just split in two okay and + + + align:start position:0% +that if you just split in two okay and +you minimize the urn the second half + + align:start position:0% +you minimize the urn the second half + + + align:start position:0% +you minimize the urn the second half +will you do what is called the holdout + + align:start position:0% +will you do what is called the holdout + + + align:start position:0% +will you do what is called the holdout +cross-validation is as good as if you + + align:start position:0% +cross-validation is as good as if you + + + align:start position:0% +cross-validation is as good as if you +had access to this okay so it's + + align:start position:0% +had access to this okay so it's + + + align:start position:0% +had access to this okay so it's +subdermal in a way now the problem with + + align:start position:0% +subdermal in a way now the problem with + + + align:start position:0% +subdermal in a way now the problem with +this is that we are only looking at say + + align:start position:0% +this is that we are only looking at say + + + align:start position:0% +this is that we are only looking at say +the error in expectation and what you + + align:start position:0% +the error in expectation and what you + + + align:start position:0% +the error in expectation and what you +can check is that if you look at higher + + align:start position:0% +can check is that if you look at higher + + + align:start position:0% +can check is that if you look at higher +order statistics say the variance of + + align:start position:0% +order statistics say the variance of + + + align:start position:0% +order statistics say the variance of +your estimators and so on and so forth + + align:start position:0% +your estimators and so on and so forth + + + align:start position:0% +your estimators and so on and so forth +what you might get is that by splitting + + align:start position:0% +what you might get is that by splitting + + + align:start position:0% +what you might get is that by splitting +in two if this big is fine in practice + + align:start position:0% +in two if this big is fine in practice + + + align:start position:0% +in two if this big is fine in practice +the data set is small you may get that + + align:start position:0% +the data set is small you may get that + + + align:start position:0% +the data set is small you may get that +the way you spray it might matter you + + align:start position:0% +the way you spray it might matter you + + + align:start position:0% +the way you spray it might matter you +might have bad luck and just fit in a + + align:start position:0% +might have bad luck and just fit in a + + + align:start position:0% +might have bad luck and just fit in a +certain way and so there is a whole + + align:start position:0% +certain way and so there is a whole + + + align:start position:0% +certain way and so there is a whole +zoology of ways of splitting and the + + align:start position:0% +zoology of ways of splitting and the + + + align:start position:0% +zoology of ways of splitting and the +basic one is a split say for this is for + + align:start position:0% +basic one is a split say for this is for + + + align:start position:0% +basic one is a split say for this is for +example the simplest okay split in a + + align:start position:0% +example the simplest okay split in a + + + align:start position:0% +example the simplest okay split in a +bunch of groups okay k fold or v-fold + + align:start position:0% +bunch of groups okay k fold or v-fold + + + align:start position:0% +bunch of groups okay k fold or v-fold +cross-validation take one group out of + + align:start position:0% +cross-validation take one group out of + + + align:start position:0% +cross-validation take one group out of +the time okay and do the same trim you + + align:start position:0% +the time okay and do the same trim you + + + align:start position:0% +the time okay and do the same trim you +know you train here and calculate the + + align:start position:0% +know you train here and calculate the + + + align:start position:0% +know you train here and calculate the +error here for different case then you + + align:start position:0% +error here for different case then you + + + align:start position:0% +error here for different case then you +do the same here do the same here do the + + align:start position:0% +do the same here do the same here do the + + + align:start position:0% +do the same here do the same here do the +same here some day errors up + + align:start position:0% +same here some day errors up + + + align:start position:0% +same here some day errors up +renormalizing and then just choose the K + + align:start position:0% +renormalizing and then just choose the K + + + align:start position:0% +renormalizing and then just choose the K +that minimize this new form of error + + align:start position:0% +that minimize this new form of error + + + align:start position:0% +that minimize this new form of error +and if the business there are small + + align:start position:0% +and if the business there are small + + + align:start position:0% +and if the business there are small +small small then typically this set will + + align:start position:0% +small small then typically this set will + + + align:start position:0% +small small then typically this set will +become very small and in the limit it + + align:start position:0% +become very small and in the limit it + + + align:start position:0% +become very small and in the limit it +becomes one they leave one out error + + align:start position:0% +becomes one they leave one out error + + + align:start position:0% +becomes one they leave one out error +okay what you do is that you literally + + align:start position:0% +okay what you do is that you literally + + + align:start position:0% +okay what you do is that you literally +leave one out train on the rest get + + align:start position:0% +leave one out train on the rest get + + + align:start position:0% +leave one out train on the rest get +there for all the values of K in this + + align:start position:0% +there for all the values of K in this + + + align:start position:0% +there for all the values of K in this +case put it back in take another one out + + align:start position:0% +case put it back in take another one out + + + align:start position:0% +case put it back in take another one out +and repeat the procedure now the + + align:start position:0% +and repeat the procedure now the + + + align:start position:0% +and repeat the procedure now the +question that I had 10-15 minutes ago + + align:start position:0% +question that I had 10-15 minutes ago + + + align:start position:0% +question that I had 10-15 minutes ago +was how do you choose V okay shall I + + align:start position:0% +was how do you choose V okay shall I + + + align:start position:0% +was how do you choose V okay shall I +make this two so I just do one split + + align:start position:0% +make this two so I just do one split + + + align:start position:0% +make this two so I just do one split +like this or shall I make it any so they + + align:start position:0% +like this or shall I make it any so they + + + align:start position:0% +like this or shall I make it any so they +do leave one out and that's right I know + + align:start position:0% +do leave one out and that's right I know + + + align:start position:0% +do leave one out and that's right I know +there is not a lot of theory that would + + align:start position:0% +there is not a lot of theory that would + + + align:start position:0% +there is not a lot of theory that would +support this you know an answer to this + + align:start position:0% +support this you know an answer to this + + + align:start position:0% +support this you know an answer to this +question and what I know is mostly you + + align:start position:0% +question and what I know is mostly you + + + align:start position:0% +question and what I know is mostly you +know what you can expect intuitively + + align:start position:0% +know what you can expect intuitively + + + align:start position:0% +know what you can expect intuitively +which is if you have a lot of data + + align:start position:0% +which is if you have a lot of data + + + align:start position:0% +which is if you have a lot of data +points what does it mean a lot I don't + + align:start position:0% +points what does it mean a lot I don't + + + align:start position:0% +points what does it mean a lot I don't +know if you have to millions ten + + align:start position:0% +know if you have to millions ten + + + align:start position:0% +know if you have to millions ten +thousand I don't know if you have a big + + align:start position:0% +thousand I don't know if you have a big + + + align:start position:0% +thousand I don't know if you have a big +data set + + align:start position:0% +data set + + + align:start position:0% +data set +typically splitting in two or maybe + + align:start position:0% +typically splitting in two or maybe + + + align:start position:0% +typically splitting in two or maybe +doing just random splits is stable + + align:start position:0% +doing just random splits is stable + + + align:start position:0% +doing just random splits is stable +enough what does it mean that you try + + align:start position:0% +enough what does it mean that you try + + + align:start position:0% +enough what does it mean that you try +okay and you look how much it moves + + align:start position:0% +okay and you look how much it moves + + + align:start position:0% +okay and you look how much it moves +whereas if you have say you know I don't + + align:start position:0% +whereas if you have say you know I don't + + + align:start position:0% +whereas if you have say you know I don't +know if it even exists application like + + align:start position:0% +know if it even exists application like + + + align:start position:0% +know if it even exists application like +you know if you were micro replication + + align:start position:0% +you know if you were micro replication + + + align:start position:0% +you know if you were micro replication +where we would have 20 30 inputs + + align:start position:0% +where we would have 20 30 inputs + + + align:start position:0% +where we would have 20 30 inputs +anywhere 20 mentions and then in that + + align:start position:0% +anywhere 20 mentions and then in that + + + align:start position:0% +anywhere 20 mentions and then in that +case you really don't do much splitting + + align:start position:0% +case you really don't do much splitting + + + align:start position:0% +case you really don't do much splitting +okay if you have 20 example you try to + + align:start position:0% +okay if you have 20 example you try to + + + align:start position:0% +okay if you have 20 example you try to +leave one out and it's the best you can + + align:start position:0% +leave one out and it's the best you can + + + align:start position:0% +leave one out and it's the best you can +do and it's really very unstable and + + align:start position:0% +do and it's really very unstable and + + + align:start position:0% +do and it's really very unstable and +sucks okay so in this case there is work + + align:start position:0% +sucks okay so in this case there is work + + + align:start position:0% +sucks okay so in this case there is work +to be done I mean there is as far as I + + align:start position:0% +to be done I mean there is as far as I + + + align:start position:0% +to be done I mean there is as far as I +know that's the state of things okay so + + align:start position:0% +know that's the state of things okay so + + + align:start position:0% +know that's the state of things okay so +we introduced the class of very simple + + align:start position:0% +we introduced the class of very simple + + + align:start position:0% +we introduced the class of very simple +algorithms they seem to be pretty + + align:start position:0% +algorithms they seem to be pretty + + + align:start position:0% +algorithms they seem to be pretty +reasonable they seem to allow us + + align:start position:0% +reasonable they seem to allow us + + + align:start position:0% +reasonable they seem to allow us +provided that we have a way to measure + + align:start position:0% +provided that we have a way to measure + + + align:start position:0% +provided that we have a way to measure +distances or similarity to go from + + align:start position:0% +distances or similarity to go from + + + align:start position:0% +distances or similarity to go from +simple to complex but and we have some + + align:start position:0% +simple to complex but and we have some + + + align:start position:0% +simple to complex but and we have some +kind of theory that tells us how what is + + align:start position:0% +kind of theory that tells us how what is + + + align:start position:0% +kind of theory that tells us how what is +the optimal value of time kind of + + align:start position:0% +the optimal value of time kind of + + + align:start position:0% +the optimal value of time kind of +practical procedure to actually choose + + align:start position:0% +practical procedure to actually choose + + + align:start position:0% +practical procedure to actually choose +it in practice okay are we done it is + + align:start position:0% +it in practice okay are we done it is + + + align:start position:0% +it in practice okay are we done it is +that all okay do we need to do anything + + align:start position:0% +that all okay do we need to do anything + + + align:start position:0% +that all okay do we need to do anything +else what's missing here one thing that + + align:start position:0% +else what's missing here one thing that + + + align:start position:0% +else what's missing here one thing that +is missing here is that most of the + + align:start position:0% +is missing here is that most of the + + + align:start position:0% +is missing here is that most of the +intuition we develop so far are really + + align:start position:0% +intuition we develop so far are really + + + align:start position:0% +intuition we develop so far are really +related to low dimension okay and here + + align:start position:0% +related to low dimension okay and here + + + align:start position:0% +related to low dimension okay and here +very quickly if you just do a little + + align:start position:0% +very quickly if you just do a little + + + align:start position:0% +very quickly if you just do a little +exercise where you try to say how + + align:start position:0% +exercise where you try to say how + + + align:start position:0% +exercise where you try to say how +is a cube that covers 1% of the bigger + + align:start position:0% +is a cube that covers 1% of the bigger + + + align:start position:0% +is a cube that covers 1% of the bigger +cube of unit length okay so the big cube + + align:start position:0% +cube of unit length okay so the big cube + + + align:start position:0% +cube of unit length okay so the big cube +is volume 1 length of Diaz use 1 and ask + + align:start position:0% +is volume 1 length of Diaz use 1 and ask + + + align:start position:0% +is volume 1 length of Diaz use 1 and ask +you how big is this if it has to cover 1 + + align:start position:0% +you how big is this if it has to cover 1 + + + align:start position:0% +you how big is this if it has to cover 1 +percent of the volume it's ready to + + align:start position:0% +percent of the volume it's ready to + + + align:start position:0% +percent of the volume it's ready to +check that you just dis is just going to + + align:start position:0% +check that you just dis is just going to + + + align:start position:0% +check that you just dis is just going to +be a D roof where D is the dimension of + + align:start position:0% +be a D roof where D is the dimension of + + + align:start position:0% +be a D roof where D is the dimension of +the cube and this is the shape of the + + align:start position:0% +the cube and this is the shape of the + + + align:start position:0% +the cube and this is the shape of the +eros okay so if you're in low dimension + + align:start position:0% +eros okay so if you're in low dimension + + + align:start position:0% +eros okay so if you're in low dimension +basically for 1% is intuitively small + + align:start position:0% +basically for 1% is intuitively small + + + align:start position:0% +basically for 1% is intuitively small +within the big cube but as soon as you + + align:start position:0% +within the big cube but as soon as you + + + align:start position:0% +within the big cube but as soon as you +go in harder dimension what you see is + + align:start position:0% +go in harder dimension what you see is + + + align:start position:0% +go in harder dimension what you see is +that the length of the edge of the + + align:start position:0% +that the length of the edge of the + + + align:start position:0% +that the length of the edge of the +little cube that has to cover one + + align:start position:0% +little cube that has to cover one + + + align:start position:0% +little cube that has to cover one +percent of the volume becomes very close + + align:start position:0% +percent of the volume becomes very close + + + align:start position:0% +percent of the volume becomes very close +to one almost immediately is this curve + + align:start position:0% +to one almost immediately is this curve + + + align:start position:0% +to one almost immediately is this curve +going up okay what does it mean that we + + align:start position:0% +going up okay what does it mean that we + + + align:start position:0% +going up okay what does it mean that we +feel call if you say I won't think you + + align:start position:0% +feel call if you say I won't think you + + + align:start position:0% +feel call if you say I won't think you +know our intuition is well one percent + + align:start position:0% +know our intuition is well one percent + + + align:start position:0% +know our intuition is well one percent +is a pretty small volume if I just took + + align:start position:0% +is a pretty small volume if I just took + + + align:start position:0% +is a pretty small volume if I just took +the neighbors in one percent they're + + align:start position:0% +the neighbors in one percent they're + + + align:start position:0% +the neighbors in one percent they're +pretty close so they should have the + + align:start position:0% +pretty close so they should have the + + + align:start position:0% +pretty close so they should have the +same label well in dimension 10 it's + + align:start position:0% +same label well in dimension 10 it's + + + align:start position:0% +same label well in dimension 10 it's +everything ok so our intuition no agency + + align:start position:0% +everything ok so our intuition no agency + + + align:start position:0% +everything ok so our intuition no agency +probably there is something wrong with + + align:start position:0% +probably there is something wrong with + + + align:start position:0% +probably there is something wrong with +my way of thinking of volume sure but + + align:start position:0% +my way of thinking of volume sure but + + + align:start position:0% +my way of thinking of volume sure but +the problem is that we have to rethink a + + align:start position:0% +the problem is that we have to rethink a + + + align:start position:0% +the problem is that we have to rethink a +bit how you think of dimensions and + + align:start position:0% +bit how you think of dimensions and + + + align:start position:0% +bit how you think of dimensions and +similarity and high dimension because + + align:start position:0% +similarity and high dimension because + + + align:start position:0% +similarity and high dimension because +things that are obviously low + + align:start position:0% +things that are obviously low + + + align:start position:0% +things that are obviously low +dimensional start to be very complicated + + align:start position:0% +dimensional start to be very complicated + + + align:start position:0% +dimensional start to be very complicated +okay and the basic idea is that this + + align:start position:0% +okay and the basic idea is that this + + + align:start position:0% +okay and the basic idea is that this +neighbor techniques just look at what's + + align:start position:0% +neighbor techniques just look at what's + + + align:start position:0% +neighbor techniques just look at what's +happening in one regions but hope to do + + align:start position:0% +happening in one regions but hope to do + + + align:start position:0% +happening in one regions but hope to do +is that if your function actually have + + align:start position:0% +is that if your function actually have + + + align:start position:0% +is that if your function actually have +some kind of global properties okay so + + align:start position:0% +some kind of global properties okay so + + + align:start position:0% +some kind of global properties okay so +say for example a sign is the simplest + + align:start position:0% +say for example a sign is the simplest + + + align:start position:0% +say for example a sign is the simplest +example of something which is global + + align:start position:0% +example of something which is global + + + align:start position:0% +example of something which is global +because the value here and the value + + align:start position:0% +because the value here and the value + + + align:start position:0% +because the value here and the value +here are very much related and then I go + + align:start position:0% +here are very much related and then I go + + + align:start position:0% +here are very much related and then I go +up and it's the same then it goes down + + align:start position:0% +up and it's the same then it goes down + + + align:start position:0% +up and it's the same then it goes down +so if you know something like this that + + align:start position:0% +so if you know something like this that + + + align:start position:0% +so if you know something like this that +is that you can borrow a strength from + + align:start position:0% +is that you can borrow a strength from + + + align:start position:0% +is that you can borrow a strength from +points which are far away in some sense + + align:start position:0% +points which are far away in some sense + + + align:start position:0% +points which are far away in some sense +the function has some similar properties + + align:start position:0% +the function has some similar properties + + + align:start position:0% +the function has some similar properties +and so you want to go from a local + + align:start position:0% +and so you want to go from a local + + + align:start position:0% +and so you want to go from a local +estimation to some form of global + + align:start position:0% +estimation to some form of global + + + align:start position:0% +estimation to some form of global +estimation okay and instead of making a + + align:start position:0% +estimation okay and instead of making a + + + align:start position:0% +estimation okay and instead of making a +decision based only on the neighbors of + + align:start position:0% +decision based only on the neighbors of + + + align:start position:0% +decision based only on the neighbors of +the point you might want to use points + + align:start position:0% +the point you might want to use points + + + align:start position:0% +the point you might want to use points +which are potentially far away okay and + + align:start position:0% +which are potentially far away okay and + + + align:start position:0% +which are potentially far away okay and +this seems to be like a good idea in + + align:start position:0% +this seems to be like a good idea in + + + align:start position:0% +this seems to be like a good idea in +high dimensions where you have that + + align:start position:0% +high dimensions where you have that + + + align:start position:0% +high dimensions where you have that +neighboring points might not be enough + + align:start position:0% +neighboring points might not be enough + + + align:start position:0% +neighboring points might not be enough +information and that's kind of what's + + align:start position:0% +information and that's kind of what's + + + align:start position:0% +information and that's kind of what's +called curse of dimensionality okay so + + align:start position:0% +called curse of dimensionality okay so + + + align:start position:0% +called curse of dimensionality okay so +what I want to do next but we can take a + + align:start position:0% +what I want to do next but we can take a + + + align:start position:0% +what I want to do next but we can take a +break here is discussing least squares + + align:start position:0% +break here is discussing least squares + + + align:start position:0% +break here is discussing least squares +and currently squares okay well what + + align:start position:0% +and currently squares okay well what + + + align:start position:0% +and currently squares okay well what +we're gonna do is that we're gonna take + + align:start position:0% +we're gonna do is that we're gonna take + + + align:start position:0% +we're gonna do is that we're gonna take +a linear model of our data and then + + align:start position:0% +a linear model of our data and then + + + align:start position:0% +a linear model of our data and then +we're gonna try to see how you can + + align:start position:0% +we're gonna try to see how you can + + + align:start position:0% +we're gonna try to see how you can +estimate and learn and we're gonna look + + align:start position:0% +estimate and learn and we're gonna look + + + align:start position:0% +estimate and learn and we're gonna look +at bit of the computation a bit of the + + align:start position:0% +at bit of the computation a bit of the + + + align:start position:0% +at bit of the computation a bit of the +statistical idea underlying this model + + align:start position:0% +statistical idea underlying this model + + + align:start position:0% +statistical idea underlying this model +and then we're going to play around in a + + align:start position:0% +and then we're going to play around in a + + + align:start position:0% +and then we're going to play around in a +very simple way to the way to extend + + align:start position:0% +very simple way to the way to extend + + + align:start position:0% +very simple way to the way to extend +from a linear model to a nonlinear model + + align:start position:0% +from a linear model to a nonlinear model + + + align:start position:0% +from a linear model to a nonlinear model +and actually make it nonparametric tell + + align:start position:0% +and actually make it nonparametric tell + + + align:start position:0% +and actually make it nonparametric tell +you what nonparametric means + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/d4xfax4_Iww.txt b/d4xfax4_Iww.txt new file mode 100644 index 0000000000000000000000000000000000000000..743f9ae2452973a6df3538b024e3de1a3ad19f01 --- /dev/null +++ b/d4xfax4_Iww.txt @@ -0,0 +1,3156 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, we're ready for +the second lecture today. + +We will start to get into a +little technical material, + +which doesn't mean necessarily +that it's more important. + +It just means that it's easier +because it deals with + +mathematics. + +I'm going to spend a little +bit more time reviewing + +probability, as you +learned it before. + +I want to review it at a +slightly more fundamental + +level than what you're +used to seeing it as. + +You will understand why as we go +on because when we get into + +stochastic processes, we will +find that there are lots of + +very peculiar things +that happen. + +And when peculiar things happen, +the only thing you can + +do is go back to basics ideas. + +And if you don't understand what +those basic ideas are, + +then you're in real trouble. + +So we'll start out by talking +about expectations just a + +little bit. + +Distribution function of a +random variable often says + +more than you're really +interested in. + +In other words, a distribution +function is a function from + +the whole sample space into +the real numbers. + +And that's a very complicated +thing in general. + +And the expectation is just +one simple number. + +And with that one simple number, +you get an idea of + +what that random variable is all +about, whether it's big or + +it's little or what have you. + +They're a bunch of formulas that +you're familiar with for + +finding the expectation. + +If you have a discrete random +variable, the usual formula is + +you take all of the possible +sample values, multiply each + +of them by the probability +of that sample value, + +and you sum it up. + +This is what you learned right +at the beginning of taking + +probability. + +If you've never taken +probability, you learned it in + +statistic classes just as +something you don't know where + +it comes from. + +But it's there. + +If you have a continuous random +variable, a continuous + +random variable is one +that has a density. + +You can find the expectation +there. + +If you have an arbitrary random +variable and it's not + +negative, then there's this +peculiar formula here, which I + +will point to. + +I think I'll point to it. + +Ah yes, I will point to it. + +This formula down here, you +might or might not have seen. + +And I hope by the end of this +course, you'll realize that + +it's one, more fundamental and +two, probably more useful than + +either of these two. + +And then there's a final one, +which this final formula, I'll + +tell you a little bit about +that when we get to it. + +OK, the formula for the expected +value in terms of the + +integral of the complimentary +distribution function. + +There's a picture here which +shows you how it corresponds + +to the usual thing you're +used to for a + +discrete random variable. + +Namely what you're doing is +you're integrating this + +complimentary distribution +function, which is the + +probability that the random +variable x is greater than any + +particular x along +the axis here. + +So you integrate this +function along here. + +And according to what I'm trying +to convince you of, + +just integrating that function +gives you the expected value. + +And the reason is that this top +little square here is a1 + +times the probability that +x is equal to a1. + +Next one is a2 times the +probability it's equal to a2 + +and so forth down. + +And you can obviously generalize +this to any + +discrete random variable, +which is non-negative. + +And I'm just talking about +non-negative random variables + +for the moment. + +If x has a density, the same +argument applies to any + +Riemann sum for that integral. + +You can take integrals. + +You can break them up +into little slices. + +If you break them up into +little slices, you can + +represent it in this way. + +And presto, again, you get that +this integral is equal to + +the expectation. + +And if you have any other thing +at all, you can always + +represent it in terms +of this Riemann sum. + +Now why is it even more +powerful then that? + +Well, it's more powerful then +that because if you took + +measure theory-- + +which most of you presumably +have not taken yet, and many + +of you might never take it-- + +you will find out that this +is really the fundamental + +definition after all. + +And integration, when you look +and measure theoretic terms, + +instead of taking little slices +that go this way, you + +wind up taking little slices +that go that way. + +So that any way this is the +fundamental definition of + +expectation. + +If you're worried about whether +expectations exist or + +not, why is this much nicer? + +Because what you're integrating +here is simply a + +function, which is monotonic +decreasing with x. + +In other words, if you try to +integrate it by integrating + +this function out to some +largest value and then + +chopping if off there, what +you get is some number. + +If you extend this chopping off +point out, what you get is + +a number which keeps +increasing. + +What can happen? + +As you take a number which is +increasing, you either get to + +infinity or you get to +some finite limit. + +Nothing else can happen. + +So there aren't any limiting +problems here. + +And when you take expectations +in other ways, there are + +always questions that +you have to ask. + +And they're often serious. + +So this is just a much nicer +way of doing it. + +Anyway, that's the way +we're going to do it. + +And so now we go on. + +Oh, I should mention where the +other formula comes from. + +This formula back here. + +You get that by representing x +as both the positive part of x + +plus the negative part of x. + +And if you want to see how to +do that exactly, it's in the + +notes where it talks about +first this and then this. + +So you just put the +two together. + +And then you get an +expected value. + +A word about notation here, and +there's nothing I can do + +about this. + +It's an unfortunate thing. + +When somebody says that the +expected value of a random + +variable exists, what +do they mean? + +Any engineer would try to +integrate it and would either + +get something which was +undefined, because it was + +infinite going this way. + +It's minus infinity +going that way. + +And there's no way to put +the two together. + +If you get infinity going this +way, something finite going + +that way, like with a +non-negative random variable, + +it's kind of silly to say the +expectation doesn't exist. + +Because really what's happening +is the expectation + +is infinite. + +Now mathematicians and everybody +who writes books, + +everybody who writes +papers, everybody-- + +I think-- + +defines expected value as +existing only if it's finite. + +In other words, what you're +doing is taking this integral + +over the set of real values. + +And you don't allow plus +infinity or minus infinity. + +So you say that the expectation +does not exist if + +in fact it's infinite or it's +minus infinity or it is + +undefined completely. + +And you say it's undefined +in all of those cases. + +And that's just a convention +that everybody lives by. + +So the other way of saying this +is if the expected value + +of the magnitude of the random +variable is infinite, then the + +expectation doesn't exist. + +So we will try to say it +that way sometimes + +when it's really important. + +OK, let's go on to indicator +random variables. + +You're probably familiar +with these. + +For every event you can think +of, an event is something + +which is true, which occurs when +some set of the sample + +points occur and is not +true otherwise. + +So the definition of an +indicator random variable is + +that the indicator +for an event a-- + +as a function of the +sample space-- + +is equal to 1, if omega is in +the event a, and 0 otherwise. + +So if you draw the distribution +function of it, + +the distribution function of the +indicator function is 0 up + +until the point 0. + +Then it jumps up to 1 minus +the probability of a. + +At 1, it jumps all +the way up to 1. + +So it's simply a binary +random variable. + +So every event has an indicator +random variable. + +Every indicator random +variable has a + +binary random variable. + +So indicator random variables +are very simple. + +Events are very simple because +you can map any event into an + +indicator random variable +[INAUDIBLE]. + +And this also says that since +we want to talk about events + +very often, binary random +variables are particularly + +important in this field. + +OK, but what this really says +now is that any theorem about + +random variables can be +applied to events. + +This is one of the few examples +I know where it's + +much harder to find the +expectation by taking the + +complimentary distribution +function and integrating it. + +It's not hard. + +But it's far easier to take +the probability that the + +indicator random variable +is 0, which is 1 minus + +probability of a. + +The probability is equal to 1, +which is probability of a, and + +take the expectation, which is +the probability of a, and the + +standard deviation, which +is the square root the + +probability of a times 1 minus +the probability of a. + +So random variables are sort +of trivial things in a way. + +OK, let's go on to multiple +random variables. + +Now here's something that's +a trick question in a way. + +But it's a very important +trick question. + +Is a random variable specified +by its distribution function? + +We've already seen that it's +not really specified by its + +density or by its probability +mass function. + +But we've said a distribution +function is a more general + +thing so that every random +variable has a + +distribution function. + +Does the distribution function +specify the random variable? + +No, that's the whole +reason for what + +Kolmogorov did back in 1933. + +Or at least it was one +of the main reasons + +for what he was doing. + +He wanted to straighten out +this ambiguity which runs + +through the field about +confusing random variables + +with their distribution +function. + +Random variables are functions +from the sample space to the + +real numbers. + +And they're not anything else. + +So if you want to really define +a random variable, you + +not only have to know what that +random variable is but + +you also have to know what +its relationships are. + +It's like if you're trying +to understand the person. + +You can't understand the person +without understanding + +something about who they know, +how they know them, all those + +other things. + +All those relationships +are important. + +And it's the same with +random variables. + +You got to know about all +the relationships. + +Many problems you can solve +just in terms of + +distribution function. + +But ultimately you have to-- + +or ultimately in many cases, +you have to deal with these + +joint distribution functions. + +And random variables +are independent. + +If the joint distribution +function is equal to the + +product of the distribution +functions for all x1 to xn, + +and that same form carries over +for density functions and + +for probability mass +functions. + +OK, if you have discrete random +variables, the idea of + +independence is a whole lot more +intuitive if you express + +it in terms of conditional +probabilities. + +The conditional probability +that the random variable x + +takes on some sample value x +given that the random variable + +y takes on a sample value y. + +Just as one side comment here, +when you're doing problems, + +you will very often want to +leave out the subscripts here + +saying what random variables +you're dealing with. + +And you will use either capital +or small letters here + +mixing up the argument and the +function itself, which + +everybody does. + +And it's perfectly all right. + +I suggest that you try not to do +it for a while because you + +get so confused doing this, +not being able to sort out + +what's a random variable and +what's a real number. + +A lot of wags say random +variables are neither random, + +because they're functions +of the sample space, + +nor are they variables. + +And both of those are true. + +That's immaterial here. + +It's just that when you start +getting confused about a + +problem, it's important to +sort out which things are + +random variables and which +things are arguments. + +Now this conditional probability +is something + +you're all familiar with. + +But x and y are independent then +if the probability of x + +conditional on y is the same +as the probability of x not + +conditional on y. + +In other words, if observing +what y is doesn't tell you + +anything about what x is, that's +really your intuitive + +definition of independence. + +It's what you use if +you're dealing with + +some real world situation. + +And you're asking what does +this have to do with that? + +And if this has nothing to +do with that, the random + +variables over here have nothing +to do with the random + +variables over there, you would +say in the real world + +that these things are +independent of each other. + +When you have a probability +model, you say they're + +statistically independent +of each other. + +OK, so that's the relationship +between the real world and the + +models that we're dealing +with all the time. + +We call it independence +in both cases. + +But it means somewhat different +things in the two + +situations. + +OK, next about IID +random variables. + +What are they? + +Well, the joint distribution +function has to be equal to + +the product of the individual +distribution functions. + +You notice I've done something +funny here, which is a + +convention I always use. + +A lot of people use it. + +If you have a bunch of +independent random variables, + +they all have the same +distribution function. + +If they all have the same +distribution function, it gets + +confusing to refer to their +distribution functions as a + +distribution function of +the random variable x1, + +distribution function of +the random variable x2. + +It's nicer to just take a +generic random variable x, + +which has the same distribution +as all of these, + +and express this numerically +in this way. + +You have the same product form +for probability mass functions + +and for density functions. + +So this works throughout. + +OK next, think about a +probability model in which r, + +the set of real numbers, +is a sample space. + +And x is some random variable +on that sample space. + +Namely x then is a function from +the real numbers on to + +the real numbers. + +The interesting thing +here, and what I'm + +saying here is obvious. + +It's something that +you all know. + +It's something that you've all +been using even before you + +started to learn about +probability theory. + +But at the same time, you +probably never thought about + +it in a serious enough way that +you would really make + +sense out of it. + +You can always create an +extended probability model in + +which the Cartesian space r to +the n-- in other words, the + +space of n real numbers-- + +is the sample space. + +And x1 to xn are independent +identity + +distributed random variables. + +This is not obvious. + +And that's something +you have to prove. + +But it's not hard to prove. + +And all you have to do is start +out with a probability + +model for one random variable. + +And then just define all +products to be what they're + +supposed to be and go from the +products to all unions and all + +intersections. + +We're just going to assume that +that's true because we + +have to assume it's true if we +don't want to use any measure + +theory here. + +This is one of the easier +things to show + +using measure theory. + +But it's something you +are always used to. + +When you think of a random +experiment, when you think of + +playing dice with somebody +or playing cards with + +someone, you are-- + +from the very beginning when you +started to talk about odds + +or anything of that sort, you +have always had the idea that + +this is a game which you +can play repeatedly. + +And each time you play it, +it's the same game. + +But the outcome is different. + +But all the probabilities +are exactly the same. + +What this says is you can always +make a probability + +model that way. + +You can always make a +probability model which + +corresponds to what you've +always believed deep in your + +hearts all your lives. + +And fortunately, that's true. + +Otherwise, you wouldn't +use probability. + +OK, so let's move +on from that. + +The page of philosophy, I will +stop doing that pretty soon. + +But I have to get across what +the relationship is between + +the real world and +these models that + +we're dealing with. + +Because otherwise, you as +engineers or business people + +or financial analysts or +whatever the heck you're going + +to become will start believing +in your probability models. + +And you will cause untold damage +by losing track of the + +fact that these are supposedly +models of something. + +And you better think of +what they're supposed + +to be models of. + +OK, in order to do that, we're +going to study the sample + +average, namely the sum of n +random variables divided by n. + +That's the way you take +sample averages. + +You add them all up. + +You divide by n. + +The law of large numbers, which +we're going to talk + +about very soon, says that s +sub n over n essentially + +becomes deterministic as +n becomes very large. + +What we mean by that-- and most +of you have seen that in + +various ways. + +We will review it later today. + +Well, we'll do it today +and on Wednesday. + +And there's a big question +of about what becoming + +deterministic means. + +But there is an essential +idea there. + +The extended model, namely +when you have one random + +variable, you create a very +large number of them. + +If it corresponds to repeated +experiments in the real world, + +then s sub n over n corresponds +to the arithmetic + +average in the real world. + +In the real world, you do take +arithmetic averages. + +Whenever you open up a +newspaper, somebody is taking + +an arithmetic average of +something and says, gee, this + +is significant. + +This shows what's going +on someplace. + +Models can have two types +of difficulties. + +This paragraph is a little +different than what I wrote in + +the handout because I realized +what I wrote in the handout + +didn't make a whole +lot of sense. + +OK, the two types of +difficulties you have with + +models, especially when you're +trying to model things by IID + +random variables. + +In one, a sequence of real +world experiments is not + +sufficiently similar and +isolated to each other to + +correspond to the IID +extended model. + +In other words, you want to +model things so that each + +time, each trial of this +experiment, you do the same + +thing but get a potentially +different answer. + +Sometimes you rig things without +trying to do so in + +such a way that these +experiments are not + +independent of each other +and in fact are very, + +very heavily biased. + +You find people taking risk +models in the financial world + +where they take all sorts +of these things. + +And they say, oh, all right, +these things are all + +independent of each other. + +They look independent. + +And then suddenly a +scare comes along. + +And everybody sells +simultaneously. + +And you find out that all these +random variables were + +not independent at all. + +They were very closely related +to each other but in a way you + +never saw before. + +OK, the other way that these +models are not true or not + +valid is that the IID +extension is OK. + +But the basic model +is not right. + +OK, in other words, +you model a coin. + +It's coming out heads with +probability 1/2. + +And somebody has put +a loaded coin in. + +And the probability that it +comes up heads is 0.45. + +And the probability that it +comes up tails is 0.55. + +And you might guess that this +person always bets on tails + +and tries to get you +to bet on heads. + +So in that case, the basic +model that you're + +using is not OK. + +So you have both of these +kinds of problems. + +You should try to keep +them straight. + +But we'll learn about these +problems through + +study of the models. + +Namely, we're not going to go +through an enormous amount of + +study on how you can bias a coin +or things of this sort. + +OK, science, symmetry, +analogies, earlier models, all + +of these are used to model +real world situations. + +Let me again talk about an +example I talked about a + +little bit last time because the +model was so trivial that + +you probably understood +everything about the model in + +the situation. + +But you didn't understand what +it was illustrating. + +You have two dice. + +One of them is red. + +And one of them is white. + +You roll them. + +By symmetry, each one comes up +to be 1, 2, 3, up to 6, each + +with equal probability. + +If you roll them with two hands +or something, they're + +going to be independent +of each other. + +And therefore, the probability +of each pair of outcomes-- + +red is equal to i. + +White is equal to j. + +Probability of each one of +those is going to be 136 + +because that's the size +of the sample space. + +Now you take two white dice. + +And you roll them. + +What's the sample space? + +Well, as far as the real world +is concerned, you can't + +distinguish a red 1 from +a white 1 and a white + +2 from a red 2. + +In other words, those two +possibilities can't be + +distinguished. + +So you might say I want to +use a sample space which + +corresponds to the-- + +what's the word I used here?-- +finest grain possible outcome + +that you can observe. + +And who would do that? + +You'd be crazy to do that. + +I mean, you have a nice model +of rolling dice where each + +outcome has probability 136. + +And you would replace that +with something where the + +probability of a 1, 1 is 136. + +But the probability of a 1, 2 is +1/18 because you can get a + +2 in two different ways. + +You get a 2 in two different +ways, which says you're really + +thinking about a red die +and a white die. + +Otherwise, you wouldn't +be able to say that. + +So the appropriate model here is +certainly to think in terms + +of a red die and a white die. + +It's what everybody does. + +They just don't talk about it. + +OK, so the point that I'm trying +to make here is that + +what you call a finest grain +model is not at all clear. + +And if it's not at all clear in +the case of dice, it sure + +as hell is not clear in most of +the kinds of problems you + +want to deal with. + +So you need something +considerably more than that. + +OK, so neither the axioms +nor experimentation + +motivate this model. + +In other words, you really +have to use common sense. + +You have to use judgment. + +And all of you have that. + +It's just that by learning +all this mathematics, you + +eventually start to think that +maybe you shouldn't use your + +common sense. + +So I have to keep saying that +no, you keep on using your + +common sense. + +You want to learn what these +models are about. + +You want to use your +common sense also. + +And you've got to go back and +forth between the two of them. + +OK, that's almost the end +of our philosophy. + +I guess one more slide. + +I'm getting tired +of this stuff. + +Comparing models for similar +situations and analyzing + +limited and effective +models helps a lot + +in clarifying fuzziness. + +But ultimately, as in +all of science, some + +experimentation is needed. + +This is like any other +branch of science. + +You need experimentation +sometimes. + +You don't want to do too much of +it because you'd always be + +doing experiments. + +But the important thing is +that the outcome of an + +experiment is a sample point. + +It's not a probability. + +You do an experiment. + +You get an outcome. + +And all you find is one sample +point, if you do the + +experiment once. + +And there's nothing that +lets you draw a + +probability from that. + +The only way you can get things +that you would call + +probabilities is to use an +extended model, hope the + +extended model corresponds to +the physical situation, and + +deal with these law of large +numbers kind of things. + +You don't necessarily need +IID random variables. + +But you need something that you +know about between a large + +number of random variables +to get from an outcome to + +something you could reasonably +call a probability. + +OK, so that's enough. + +Let's go on to the law +of large numbers. + +Let's do it in pictures first. + +So you can lie back and relax +for a minute or stop being + +bored by all this stuff. + +What I've done here is to take +the simplest random variable I + +can think of, which as +you might guess is a + +binary random variable. + +It's either 0 or 1. + +Here it's 1 with probability +1/4 and 0 + +with probability 3/4. + +I have actually calculated +these things. + +The distribution function of +x1 plus x2 plus x3 plus x4, + +this point down here, +is the probability + +of all 0's, I guess. + +And then you get the probability +of all 0's plus 1, + +1 and so forth. + +Here's where you take the sum +of 20 random variables. + +And you're looking at the +distribution function of the + +number of 1's that you get. + +And it comes out like this. + +Here you're looking at s50. + +You're adding up 50 +random variables. + +And what's happening as far +as the gross picture + +is concerned here? + +Well, the mean value of s sub +n is the mean of a sum of + +random variables. + +And that's equal to n times +a mean of a single random + +variable when you have +identically distributed random + +variables or random variables +that have the same mean. + +The variance is equal to +n times sigma squared. + +Namely, when you take the +expected value of this + +quantity squared, all these +cross terms are going to + +balance out with the +mean when you do. + +I mean, all of you know how to +find the variance of s sub n. + +I hope you know how +to find that. + +And when you do that, +it increases with n. + +And the mean increases with n. + +The standard deviation, which +gives you a picture of how + +wide the distribution is, +only goes up as the + +square root of n. + +This is really the essence of +the weak law of large numbers. + +I mean, everything else is +mathematical detail. + +And then if you go on beyond +this and you talk about the + +sample average, namely the sum +of these n random variables-- + +assume them IID again. + +In fact, assume for this picture +that they're the same + +binary random variables. + +You look at the sample +average. + +You find the mean of +the sample average. + +And it's the mean of a single +random variable. + +You find the variance of it. + +Because of this n here and the +squaring that you're doing, + +the variance of the sum divided +by n, the sigma + +squared divided by n, what +happens as n gets large? + +This variance goes to 0. + +What happens when you have a +random variable, a sequence of + +random variables, all of which +have the same mean and whose + +standard deviation +is going to 0? + +Well, you might play around with +a lot of funny kinds of + +things that you might think +of as happening. + +But essentially what's going +on here is the nice feature + +that when you add all these +things up, the distribution + +function gets scrunched +down into a unit step. + +In other words, since the +standard deviation is going to + +0, the sequence of random +variables-- + +since they all have +the same mean-- + +they all have smaller and +smaller standard deviations. + +The only way you can do that is +to scrunch them down into a + +limiting random variable, +which is deterministic. + +And you can see that +happening here. + +Namely the largest value is +the black thing, which is + +getting smaller and smaller. + +And the left side is +going that way. + +On the right side, it's +going that way. + +So it looks like it's +approaching a unit step. + +That has to be proven. + +And there's a simple +proof of it. + +And we'll see that. + +And you've all seen +that before. + +And you've all probably +said, ho-hum. + +But that's the way it is. + +Now the next thing to look at +for this same set of random + +variables, the same sum, is +you look at the normalized + +sum, namely sn minus +n times the mean. + +And you divide that by the +square root of n times sigma. + +And what do you get? + +Well, every one of these +random variables-- + +for every n has mean 0, has mean +0 because the mean of sn + +is n times x bar. + +So you're subtracting off +of the mean essentially. + +And every one of them +has variance 1. + +So you've got a whole sequence +of random variables, which are + +just sticking there at +the same mean, 0, + +and at the same variance. + +What's extraordinary when you +do that, and you can sort of + +see this happening a little +bit, this curve looks like + +it's going into a fixed +curve, which starts + +out sticking to 0. + +And then it gradually +comes up. + +And it looks fairly smooth. + +It goes off this way. + +And if you read a lot about this +or if you think that all + +respectable random variables are +Gaussian random variables, + +and I hope at the end of this +course you will realize that + +only most respectable +random variables are + +Gaussian random variables. + +There are many very interesting +random variables + +that aren't. + +But what the central limit +theorem says is that as you + +add up more and more random +variables and you look at this + +normalized sum here, what you +get is in fact the normal + +distribution, which is this +strange integral here, that e + +to the minus x squared +over 2 times the x. + +Now what I want to do with the +rest of our time is to show + +you why in fact that happens. + +I've never seen this proof +of the central + +limit theorem before. + +I'm sure that some people +have done it. + +I'm only going to do it for +the case of a binomial + +distribution, which is the only +place where this works. + +But I think in doing this you +will see why in fact that + +strange e to the minus x squared +over 2 comes up. + +It sure is not obvious by +looking at this problem. + +OK, so that's what we're +going to do. + +And I'm hoping that after you +see this, you will in fact + +understand why the central limit +theorem is true as well + +as knowing that it's true. + +OK, so let's look at the +Bernoulli process. + +You have a sequence of binary +random variables, each of them + +is IID, each of them is +1 with probability p. + +And a 0 with probability +q equals 1 minus p. + +You add them all up. + +They're IID. + +And the question is, what +does the distribution of + +the sum look like? + +Well, it has a nice +formula to it. + +It's that formula down there. + +You've probably seen that +formula before. + +Let's get some idea +of where it comes + +from and what it means. + +Each n tuple that starts with +k1's and then ends with n + +minus k0's, each one of those +has the same probability. + +And it's p to the k times +q to the n minus k. + +In other words, the probability +you get a 1 on the + +first toss is p. + +The probability you get a 1 on +the second toss also, since + +those are independent, +probability you get two 1's in + +a row is p squared. + +Probably you get three 1's +in a row is p cubed and + +so forth up to k. + +Because we're looking at the +probability that the first k + +outputs are 1, so the +probability of + +that is p to the k. + +That's this term. + +And the probability that the +rest of them are all 0's is q + +to the n minus k. + +And this is sometimes confusing +to you because you + +often think that this is going +to be maximized when k is + +equal to p over n. + +You have some strange view of +the law of large numbers. + +Well no, this quantity-- + +if p is less than 1/2, it's +going to be largest at k + +equals zero. + +The most probable single outcome +from n tosses of a + +coin, and it's a biased +coin, it comes out 1's + +more often than 0's. + +0's are more probable +than 1's. + +The most probable output +is all 0's. + +Very improbable, but that's the +most probable of all these + +improbable things. + +But as you probably know +already, there are n choose k + +different n tuples, all of which +have k1's in them and n + +minus k0's. + +If you don't know that, +I didn't even + +put that in the text. + +I put most things there. + +This is one of those basic +combinatorial facts. + +Look it up in Wikipedia. + +You'll probably get a cleaner +explanation of it there than + +anywhere else. + +But look it up in any elementary +probability book or + +in any elementary combinatorics +book. + +I'm sure that all of you +have seen this stuff. + +So when you put this together, +the probability that the sum + +of a n random variables, all +of which are binary, the + +probability of getting k1's is +n choose k times p to the k + +times q to the n minus k. + +Now you look at that. + +And if k is 1,000 and if n is +1,000, I mean, your eyes + +boggle because you can't +imagine what that + +number looks like. + +So we want to find out +what it looks like. + +And here's a tricky +way of doing it. + +What we want to do is to see +how this varies with k. + +And in particular, we want to +see how it varies with k when + +n is very large and when k is +relatively close to p times n. + +So what we're going to do +is take the ratio of the + +probability of k plus 1 1's +to the ratio of k1's. + +And what is that? + +I've written it out. + +n choose k, n choose +k plus 1-- + +which is this term here-- + +is n factorial divided by k plus +1 factorial times n minus + +k minus 1 factorial. + +This term here-- + +you put the n factorial down +on the bottom, k factorial + +times n minus k quantity +factorial. + +And then you take the +p's and the q's. + +For this term here you have p +to the k plus 1 q to the n + +minus k minus 1. + +And for this one here you +have p to the k times p + +to the n minus k. + +All that stuff cancels out, +which is really cute. + +When you look at this term you +have p to the k plus 1 + +over p to the k. + +That's just p. + +And here you have q to the +n minus k minus 1 over q + +to the n minus k. + +That's just q in the +denominator. + +So this goes into p over q. + +This quantity here is almost +a simple n factorial over n + +factorial is 1. + +k plus 1 factorial divided by +k factorial is k plus 1. + +That's this term here. + +And the n minus k over n minus +k minus 1 is n minus k. + +So this ratio here +is just that very + +simple expression there. + +Now this ratio is strictly +decreasing in k. + +How do I see that? + +Well, as k gets bigger and +bigger, what happens? + +As k gets bigger, the numerator +gets larger. + +The denominator-- + +excuse me, as k gets larger, +the numerator gets smaller. + +The denominator gets larger. + +So the ratio of the +two gets smaller. + +So this whole quantity here, +as k gets larger and larger + +for fixed n, is just decreasing +and decreasing and + +decreasing. + +Now let's look a little bit at +where this crosses 1, if it + +does cross 1. + +And what I claim here is that +when k plus 1 is less than or + +equal to pn, what +happens here? + +Well if I can do this-- + +I usually get confused +doing these things. + +But if k plus 1 is less than +or equal to pn, this is the + +last of these choices here, then +k is also less than or + +equal to pn. + +And therefore, n minus +k is greater than-- + +in fact, k is strictly +less than pn. + +And n minus k is strictly +greater than n minus pn. + +And since q is 1 minus +p, this is n times q. + +OK, so you take this +divided by this. + +And you take this +divided by this. + +And sure enough, this ratio +here is greater than 1 any + +time you have a k which is +smaller than what you think k + +ought to be, which +is p over n. + +OK, so you have these three +quantities here. + +Let me go on to the +next slide. + +Since these ratios are less +than 1 when k is large, + +approximately equal to 1 when k +is close to pn, and greater + +than 1 when it's smaller than +1, if I plot these things, + +what I find is that as k is +increasing, getting closer and + +closer to pn, it's getting +larger and larger. + +As k is increasing further, +getting larger than pn, this + +ratio says that these +things have to be + +getting smaller and smaller. + +So just from looking at this, we +know that these terms have + +to be increasing for terms less +than pn and have to be + +decreasing for terms +greater than pn. + +So this is a bell-shaped +curve. + +We've already seen that. + +It might not be quite clear that +it's bell-shaped in the + +sense that it kind of tapers +off as you get smaller. + +Because these ratios are getting +bigger and bigger, as + +k gets bigger and bigger, the +ratio of this term to this + +term gets bigger and bigger. + +So what's happening there? + +As this ratio gets bigger and +bigger, these terms get + +smaller and smaller. + +But as these terms get smaller +and smaller, they're getting + +closer and closer to 0. + +So even though they're going to +0 like a bat out of hell, + +they still can't get +any smaller than 0. + +So they just taper down and +start to get close to 0. + +So that is roughly how +this sum of binary + +random variables behave. + +OK, so let's go on and show that +the central limit theorem + +holds for the Bernoulli +process. + +And that's just as +easy really. + +There's nothing more difficult +about it that we + +have to deal with. + +This ratio, as we've said, is +equal to n minus k over k plus + +1 times p over k. + +What we're interested +in here-- + +I mean, we've already seen from +the last slide that the + +interesting thing here +is the big terms. + +And the big terms are the terms +which are close to pn. + +So what we'd like to do is look +at values of k which are + +close to pn. + +What I've done here is to plot +this as k minus the integer + +value of pn. + +So we get integers. + +What I'm going to assume now, +because this gets a little + +hairy if I don't do that, I'm +going to assume that pn is + +equal to an integer. + +It doesn't make a whole lot of +difference to the argument. + +It just leaves out a lot +of terms that you don't + +have to play with. + +So we'll assume that +pn is an integer. + +With this example, we're +looking at where + +p is equal to 1/4. + +Pn is going to be an integer +whenever n is a multiple of 4. + +So things are fine then. + +If I try to make p equal to 1 +over pi, then that doesn't + +work so well. + +But after all, no reason to +chose p in such a strange way. + +OK, so I'm going to look at this +for a fixed value of n. + +I'm going to look at it as k +increases for k less than pn. + +I'm going to look at it +as it decreases for k + +greater than pn. + +And I'm going to define k to +be equal to the i plus pn. + +So I'm going to put the whole +thing in terms of + +i instead of k. + +OK, so when I substitute i +equals k minus pn for k here, + +what I'm going to get +is this term. + +It's going to be the probability +of pn plus i plus + +1 over p of-- + +fortunately when you're using +textures, you can distinguish + +different kinds of p's. + +I have too many p's +in this equation. + +This is the probability +mass function. + +This is just my probability +of a 1. + +And p's are things that you +like to use a lot in + +probability. + +So it's nice to have that +separation there. + +OK, when I take this and I +substitute it into that with k + +equal to i, what I get is +n minus pn minus i. + +That's n minus k over pn plus +i plus 1 times p over q. + +Fair enough, OK, all I'm doing +is replacing k with pn plus i + +because I want i to be very +close to 0 in this argument. + +Because I've already seen that +these terms are only + +significant when i is relatively +close to 0. + +Because when I get away from 0, +these terms are going down + +very, very fast. + +So when I do that, +what do I get? + +I get n minus pn +is equal to qn. + +That's nice. + +So I have an nq here. + +I have a q here. + +I have a pn here. + +I have a p here. + +I'm going to multiply +this p by n. + +I'm going to multiply +this q by n. + +And I'm going to take a ratio +of this pair of things. + +So when I take this ratio, +I'm going to get nq over + +nq, which is 1. + +And the other terms there +become minus i over nq. + +In the denominator, I'm going to +divide pn plus i plus 1 by + +p, by pn, which gives me 1 plus +i plus 1 divided by np. + +So I get two terms, ratio of +two terms, which are both + +close to 1 at this point and +which are getting closer and + +closer to 1 as n gets +larger and larger. + +Now let's take the logarithm +of this. + +Let me justify taking the +logarithm of it in two + +different ways. + +One of them is that what +we're trying to prove-- + +and I'm playing the game +that all of you + +always play in quizzes. + +When you're trying to prove +something, what do you do? + +You start at the beginning. + +You work this way. + +You start at the end. + +You work back this way. + +And you hope, at some point, the +two things come together. + +If they don't come together, +you get to this point. + +And you say, obviously. + +And then you go to that point +which leads to-- yeah. + +[LAUGHTER] + +PROFESSOR: OK, so I'm doing +the same thing here. + +This probability that we're +trying to calculate-- + +well, I've listed it +here in terms of-- + +I have put it here in terms of +a distribution function. + +I will do just as well if I can +do it in terms of an PMF. + +And what I'd like to show is +that the PMF of sn minus nX + +bar over square root of n +times sigma is somehow + +proportional to e to the +minus x squared over 2. + +Now if I want to do that, it +will be all right if I can + +take the logarithm of this +term and show that + +it's a square nX. + +And if I want to show that this +logarithm is a square nX, + +and I'm looking at the +differentials at each time, + +what are the differentials going +to be if the sum of the + +differentials is quadratic? + +If the sum of these +differentials is quadratic, + +then the individual terms +have to be linear. + +If I take a bunch of linear +terms, if I add up 1 plus 2 + +plus 3 plus 4 plus 5, you've +all done this I'm sure. + +And down here you write n plus +n minus 1 plus, plus 1. + +And what do you get? + +You get n times n +plus 1 over 2. + +You can also approximate +that by integrating. + +Whenever you add up a sum +of linear terms, you + +get a square term. + +And I'm just curious. + +How many of you have +seen that? + +Good, OK. + +Well, it's only about 1/2. + +So it's something you've +probably seen in high school. + +Or your haven't seen +it at all. + +So let's go on with +this argument. + +OK, so I'm going to take +the logarithm of + +this expression here. + +I'm going to take +the logarithm. + +I'm going to have the logarithm +of 1 minus i over nq + +minus the logarithm of 1 +plus i plus 1 over np. + +And I'm going to use what I +think of as one of the most + +useful inequalities that you +will ever see, which is the + +natural log of 1 plus x. + +If we use a power expansion, we +get x minus x squared over + +2 plus x cubed over 3 minus-- + +it's an alternating series. + +If x is negative, this +term is negative. + +This term is negative. + +This term is negative. + +And all this makes sense +because if I draw this + +function here, logarithm of +1 plus x at x equals 0. + +This is equal to 0. + +It comes up with a slope of 1. + +And it levels off. + +And here it's going +down very fast. + +So these terms, you get +these negative terms. + +And on the positive side, you +get these alternating terms. + +So this goes up slowly, +down fast. + +The slope here is x, which +is this term here. + +The curvature here gives you +the minus x squared over 2. + +And the approximation, which is +very useful here, is that + +the logarithm of 1 plus x, when +x is small, is equal to x + +plus what we call +little l of x. + +Namely something which goes +to 0 faster than x + +as x goes to 0. + +OK, all of you know +that, right? + +Well, if you don't know +it, now you know it. + +It's useful. + +You will use it again +and again. + +OK, so what we're +going to do is-- + +well, that's pretty good. + +Where did I get to that point? + +I skipped something. + +What I have shown is that this +increment in the probability, + +in the PMF for s sub n, namely +the increment as you increase + +i by 1, is linear in i. + +And in fact, the logarithm of +this increment is linear in i. + +So therefore, by what I was +saying before, the logarithm + +of the actual terms should be +rather than linear in i, they + +should be quadratic in i. + +So that's what I'm trying +to do here. + +I just missed this +whole term here. + +What I'm interested in now is +getting a handle on pn plus + +some larger value, +j, divided by the + +probability of sn for pn. + +What am I trying to do here? + +I should've said what +I was trying to do. + +This term is just one term. + +It's fixed. + +Be nice if we knew what it was, +we don't at the moment. + +But I'm trying to express +everything else in terms of + +that one unknown term. + +And what I'm trying to do is to +show that the logarithm of + +this everything else is going +to be quadratic in j. + +And if I can do that, then I +only have one undetermined + +factor in this whole sum. + +And I can use the fact that PMF +summed to 1 to solve the + +whole problem. + +So I'm going to express the +probability that we get pn + +plus j1's divided by the +probability that we get pn1's. + +It's the sum of the probability +pn plus i plus 1 + +over pn plus i. + +And we increase i. + +We start out at i equals 0. + +And then the denominator is +probability of pn plus 0, + +which is this term. + +And each time we increase i by +1, this term cancels out with + +the previous or the next +value of this term. + +And when I get all done, all I +have is this expression here. + +Everybody see that? + +OK, I see a lot of-- + +if you don't see it, +just look at it. + +And you'll see that this-- + +I think you'll see +that this works. + +OK, so now I take this +expression here. + +This logarithm is this +linear term here. + +What do I want to do? + +I want to sum i from +0 up to j minus 1. + +What do I get when I sum +i from 0 to j minus 1? + +I get this expression here. + +I get j times j minus +1 divided by 2n. + +Oh, I was-- + +I skipped something. + +Let's go back a little bit. + +Because it'll look like +it was a typo. + +When I took this logarithm and +I applied this approximation + +to it, I got minus i over nq +minus i over np minus 1 over + +np plus square terms in n. + +When I take i over nq minus i +over np, I can combine those + +two things together. + +I can take ip over npq +minus iq times npq. + +And q plus p is equal to 1. + +So the numerator +all goes away. + +And these two terms combine to +be minus i over n times p + +times p times q. + +And I just has this one last +little term left here. + +Don't know what to +do with that. + +But then I add up +all these terms. + +This one is the one that +leads to j times j + +minus 1 over 2 npq. + +This one is the one that +leads to j over np. + +And I just neglect this term, +which is negligible compared + +to j squared. + +I get minus j squared +over 2 npq. + +Let me come back later to say +why I'm so eager to neglect + +this term except that that's +what I have to do if I want to + +get the right answer. + +OK, so we'll see why that has +to be negligible in just a + +little bit. + +But now this logarithm is coming +out to be exactly the + +term that I want it to be. + +So finally, the logarithm of +the sum of these random + +variables pn plus j, namely j +off the mean, divided by that + +if pn is equal to minus j +squared over 2 npq plus some + +negligible terms. + +And this says when I +exponentiate things, that the + +probability that sn is j off +the mean is approximately + +equal to this term, the +probability that it's right at + +the mean, times e to the minus +j squared over 2 npq. + +What that is saying is that this +sum of terms that I was + +looking at before-- + +this term here, this term, this +term, this term, this + +term, and so forth down-- + +these terms here are actually +going as minus j squared over + +2 npq, which is what they should +be going as if you have + +a Gaussian curve here. + +OK, now there's one other thing +we have to do, which is + +figure out what this term is. + +And if you look at this as an +undetermined coefficient on + +these Gaussian-type terms and +you think of what happens if I + +sum this over all i, well, if +I sum it over all i what I'm + +going to get is the sum of all +of these terms here, which are + +negligible except where j +squared is proportional to n. + +So I don't have to sum them +beyond the point where this + +approximation makes sense. + +So I want to sum all +these terms. + +In summing these terms, when n +gets very, very large, these + +things are dropping off +very, very slowly. + +The curve is getting +very, very wide. + +If i scrunch the curve back in +again, what I get is a Riemann + +approximation to a normal +density curve. + +Therefore, I can integrate it. + +And believe me. + +If you don't believe me, +I'll go through it. + +And you won't like that. + +When you go through this, what +you get is in fact this + +expression right here, which +says that when n gets very, + +very large and j is the offset +from the mean and is + +proportional to-- + +well, it's proportional to +the square root of n. + +Then what I get is this PMF +here, which is in fact what + +the central limit +theorem says. + +And now if you go back and try +to think of exactly what we've + +done, what we've done is to +show that the logarithm of + +these differences here is +in fact linear in i. + +Therefore, when you sum them, +you get something which is + +quadratic in j. + +And because of that, all you +have to do is normalize with a + +center term. + +And you get this. + +The central limit theorem, +especially for the binary + +case, is almost always done +by using a Stirling + +approximation. + +And a Stirling approximation is +one of these things which + +is black magic. + +I don't know any place except in +William Feller's book where + +anyone talks about where this +formula comes from. + +If you now go back and look +very carefully at this + +derivation, this tells +you what the Stirling + +approximation is. + +Because if you do this for p +equals q, what you're doing is + +actually evaluating n choose +k where k is very + +close to and over 2. + +And that will tell you exactly +what Stirling's + +approximation has to be. + +In other words, that's a way +of deriving Stirling's + +approximation. + +The very backward way of +doing things it seems. + +But often backward ways +are the best ways + +of doing these things. + +OK, so I told you I +would stop at some + +point and ask for questions. + +Yes? + +AUDIENCE: Can you please go +back one slide before this + +slide where can you neglect +a term, which [INAUDIBLE], + +minus j over np. + +PROFESSOR: Why did I neglect +the j over np? + +OK, that's a good question. + +If you look at this curve here, +and I put the j in. + +I can put the j in by just +making this expression here + +look at one smaller value of +j or one larger value of j. + +And you get something different +whether you're + +looking at the minus side +or the plus side. + +In fact, if p is equal to q, +this term cancels out. + +If p is not equal to q, what +happens is that the central + +limit theorem is approximately +symmetric. + +But in this first ordered term, + +it's not quite symmetric. + +It can't be symmetric because +this is p times n. + +And you have all these +terms out to 1. + +And you have many, many +fewer terms back to 0. + +So it has to be slightly +asymmetric. + +But it's only asymmetric over at +most a unit of value here, + +which is not significant. + +Because as n gets bigger, +these terms-- + +well, as I've done +it, the terms do + +not get close together. + +But if I want to think of it +as a normalized Gaussian + +curve, I have to make the +terms close together. + +So that extra term is +not significant. + +I wish I had a nicer way of +taking care of all the + +approximations here. + +I haven't put this in the notes +because I still haven't + +figured out how to do that. + +But I still think you get more +insight from doing it this way + +than you do by going through +Stirling's approximation, all + +those pages and pages +of algebra. + +Anything else? + +OK, well, see you +Wednesday then. \ No newline at end of file diff --git a/dBMtJEt6aO8.txt b/dBMtJEt6aO8.txt new file mode 100644 index 0000000000000000000000000000000000000000..9ffb195d039cad235479416d4ff691651b693c3d --- /dev/null +++ b/dBMtJEt6aO8.txt @@ -0,0 +1,1107 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu this demonstration is for + + align:start position:0% +ocw.mit.edu this demonstration is for + + + align:start position:0% +ocw.mit.edu this demonstration is for +those of you who would like to dig a + + align:start position:0% +those of you who would like to dig a + + + align:start position:0% +those of you who would like to dig a +little more deeply into laser behavior + + align:start position:0% +little more deeply into laser behavior + + + align:start position:0% +little more deeply into laser behavior +as we know a laser like this one here + + align:start position:0% +as we know a laser like this one here + + + align:start position:0% +as we know a laser like this one here +consists of two mirrors and an amplifier + + align:start position:0% +consists of two mirrors and an amplifier + + + align:start position:0% +consists of two mirrors and an amplifier +and if the gain of the amplifier is + + align:start position:0% +and if the gain of the amplifier is + + + align:start position:0% +and if the gain of the amplifier is +bigger than the losses in the cavity + + align:start position:0% +bigger than the losses in the cavity + + + align:start position:0% +bigger than the losses in the cavity +then we can get laser action and if + + align:start position:0% +then we can get laser action and if + + + align:start position:0% +then we can get laser action and if +let's say this mirror has a little bit + + align:start position:0% +let's say this mirror has a little bit + + + align:start position:0% +let's say this mirror has a little bit +of transmission then we can get laser + + align:start position:0% +of transmission then we can get laser + + + align:start position:0% +of transmission then we can get laser +light coming out that we can use so let + + align:start position:0% +light coming out that we can use so let + + + align:start position:0% +light coming out that we can use so let +me turn then this laser on and show you + + align:start position:0% +me turn then this laser on and show you + + + align:start position:0% +me turn then this laser on and show you +here on this card the the output of the + + align:start position:0% +here on this card the the output of the + + + align:start position:0% +here on this card the the output of the +laser now in this demonstration we'd + + align:start position:0% +laser now in this demonstration we'd + + + align:start position:0% +laser now in this demonstration we'd +like to show that the light inside the + + align:start position:0% +like to show that the light inside the + + + align:start position:0% +like to show that the light inside the +laser cavity that's going backwards and + + align:start position:0% +laser cavity that's going backwards and + + + align:start position:0% +laser cavity that's going backwards and +forwards between the two mirrors inside + + align:start position:0% +forwards between the two mirrors inside + + + align:start position:0% +forwards between the two mirrors inside +the laser cavity is much bigger than + + align:start position:0% +the laser cavity is much bigger than + + + align:start position:0% +the laser cavity is much bigger than +then the light that's coming outside + + align:start position:0% +then the light that's coming outside + + + align:start position:0% +then the light that's coming outside +question is how do we how do we do this + + align:start position:0% +question is how do we how do we do this + + + align:start position:0% +question is how do we how do we do this +because if we try to place a detector + + align:start position:0% +because if we try to place a detector + + + align:start position:0% +because if we try to place a detector +inside the laser cavity like here we + + align:start position:0% +inside the laser cavity like here we + + + align:start position:0% +inside the laser cavity like here we +would interrupt the laser action the + + align:start position:0% +would interrupt the laser action the + + + align:start position:0% +would interrupt the laser action the +laser quits so obviously that's not a + + align:start position:0% +laser quits so obviously that's not a + + + align:start position:0% +laser quits so obviously that's not a +smart way of doing this so what are we + + align:start position:0% +smart way of doing this so what are we + + + align:start position:0% +smart way of doing this so what are we +going to do I'm going to use a simple + + align:start position:0% +going to do I'm going to use a simple + + + align:start position:0% +going to do I'm going to use a simple +method like this we're going to take a + + align:start position:0% +method like this we're going to take a + + + align:start position:0% +method like this we're going to take a +piece of glass and depending on the + + align:start position:0% +piece of glass and depending on the + + + align:start position:0% +piece of glass and depending on the +orientation of the piece of glass we're + + align:start position:0% +orientation of the piece of glass we're + + + align:start position:0% +orientation of the piece of glass we're +going to sample the light both outside + + align:start position:0% +going to sample the light both outside + + + align:start position:0% +going to sample the light both outside +the cavity and inside the cavity and + + align:start position:0% +the cavity and inside the cavity and + + + align:start position:0% +the cavity and inside the cavity and +hopefully that the the the loss that we + + align:start position:0% +hopefully that the the the loss that we + + + align:start position:0% +hopefully that the the the loss that we +will place inside the cavity laser + + align:start position:0% +will place inside the cavity laser + + + align:start position:0% +will place inside the cavity laser +cavity is so small that we will not + + align:start position:0% +cavity is so small that we will not + + + align:start position:0% +cavity is so small that we will not +interrupt the laser action at least by + + align:start position:0% +interrupt the laser action at least by + + + align:start position:0% +interrupt the laser action at least by +by too much alright so here we go so + + align:start position:0% +by too much alright so here we go so + + + align:start position:0% +by too much alright so here we go so +first we have to show that + + align:start position:0% +first we have to show that + + + align:start position:0% +first we have to show that +ah that we can sample some of the light + + align:start position:0% +ah that we can sample some of the light + + + align:start position:0% +ah that we can sample some of the light +with with this piece of glass so here we + + align:start position:0% +with with this piece of glass so here we + + + align:start position:0% +with with this piece of glass so here we +are is this piece of glass now let me + + align:start position:0% +are is this piece of glass now let me + + + align:start position:0% +are is this piece of glass now let me +tell you what's what's happening this + + align:start position:0% +tell you what's what's happening this + + + align:start position:0% +tell you what's what's happening this +piece of glass is is placed in this + + align:start position:0% +piece of glass is is placed in this + + + align:start position:0% +piece of glass is is placed in this +orientation and then I can rotate it + + align:start position:0% +orientation and then I can rotate it + + + align:start position:0% +orientation and then I can rotate it +like so this using this rotation stage + + align:start position:0% +like so this using this rotation stage + + + align:start position:0% +like so this using this rotation stage +now if you look at the reflection from + + align:start position:0% +now if you look at the reflection from + + + align:start position:0% +now if you look at the reflection from +piece of glass on this little screen you + + align:start position:0% +piece of glass on this little screen you + + + align:start position:0% +piece of glass on this little screen you +can see that the light gets the + + align:start position:0% +can see that the light gets the + + + align:start position:0% +can see that the light gets the +extinguished when I am at at the + + align:start position:0% +extinguished when I am at at the + + + align:start position:0% +extinguished when I am at at the +Brewster angle remember the the + + align:start position:0% +Brewster angle remember the the + + + align:start position:0% +Brewster angle remember the the +polarization of this laser in the + + align:start position:0% +polarization of this laser in the + + + align:start position:0% +polarization of this laser in the +vertical plane so that I can I can + + align:start position:0% +vertical plane so that I can I can + + + align:start position:0% +vertical plane so that I can I can +achieve Brewster angle condition using + + align:start position:0% +achieve Brewster angle condition using + + + align:start position:0% +achieve Brewster angle condition using +this orientation of the glass so so now + + align:start position:0% +this orientation of the glass so so now + + + align:start position:0% +this orientation of the glass so so now +when I have brewster boosters angle it's + + align:start position:0% +when I have brewster boosters angle it's + + + align:start position:0% +when I have brewster boosters angle it's +when these two markers one on the on the + + align:start position:0% +when these two markers one on the on the + + + align:start position:0% +when these two markers one on the on the +rotating part of the stage and the other + + align:start position:0% +rotating part of the stage and the other + + + align:start position:0% +rotating part of the stage and the other +one on the fixed part of the rotation + + align:start position:0% +one on the fixed part of the rotation + + + align:start position:0% +one on the fixed part of the rotation +state when they line up we're at + + align:start position:0% +state when they line up we're at + + + align:start position:0% +state when they line up we're at +Brewster's angle and when I move away + + align:start position:0% +Brewster's angle and when I move away + + + align:start position:0% +Brewster's angle and when I move away +from Brewster's angle like so I can + + align:start position:0% +from Brewster's angle like so I can + + + align:start position:0% +from Brewster's angle like so I can +increase the amount of light sampled by + + align:start position:0% +increase the amount of light sampled by + + + align:start position:0% +increase the amount of light sampled by +the piece of glass so let's say if i set + + align:start position:0% +the piece of glass so let's say if i set + + + align:start position:0% +the piece of glass so let's say if i set +it this position here then i have a + + align:start position:0% +it this position here then i have a + + + align:start position:0% +it this position here then i have a +small percentage of light that's + + align:start position:0% +small percentage of light that's + + + align:start position:0% +small percentage of light that's +reflected by the piece of glass onto + + align:start position:0% +reflected by the piece of glass onto + + + align:start position:0% +reflected by the piece of glass onto +onto the screen now what i'm going to do + + align:start position:0% +onto the screen now what i'm going to do + + + align:start position:0% +onto the screen now what i'm going to do +is take a similar piece of glass and put + + align:start position:0% +is take a similar piece of glass and put + + + align:start position:0% +is take a similar piece of glass and put +it again in the in the beam like so and + + align:start position:0% +it again in the in the beam like so and + + + align:start position:0% +it again in the in the beam like so and +again the markers are the same as in the + + align:start position:0% +again the markers are the same as in the + + + align:start position:0% +again the markers are the same as in the +is in the other stage so when the when + + align:start position:0% +is in the other stage so when the when + + + align:start position:0% +is in the other stage so when the when +the markers are lined up then I get no + + align:start position:0% +the markers are lined up then I get no + + + align:start position:0% +the markers are lined up then I get no +light reflected this means Bruce's + + align:start position:0% +light reflected this means Bruce's + + + align:start position:0% +light reflected this means Bruce's +condition and when I'm over here I get + + align:start position:0% +condition and when I'm over here I get + + + align:start position:0% +condition and when I'm over here I get +pretty much the same amount of light as + + align:start position:0% +pretty much the same amount of light as + + + align:start position:0% +pretty much the same amount of light as +as in as in this case all right so now I + + align:start position:0% +as in as in this case all right so now I + + + align:start position:0% +as in as in this case all right so now I +have calibrated these two pieces of + + align:start position:0% +have calibrated these two pieces of + + + align:start position:0% +have calibrated these two pieces of +glass in terms of in terms of angle now + + align:start position:0% +glass in terms of in terms of angle now + + + align:start position:0% +glass in terms of in terms of angle now +what I'm going to do I'm going to take + + align:start position:0% +what I'm going to do I'm going to take + + + align:start position:0% +what I'm going to do I'm going to take +one of them + + align:start position:0% +one of them + + + align:start position:0% +one of them +and without changing the angle place it + + align:start position:0% +and without changing the angle place it + + + align:start position:0% +and without changing the angle place it +inside the laser cavity and hopefully + + align:start position:0% +inside the laser cavity and hopefully + + + align:start position:0% +inside the laser cavity and hopefully +the laser won't go out on me so as I put + + align:start position:0% +the laser won't go out on me so as I put + + + align:start position:0% +the laser won't go out on me so as I put +it in here without changing the angle + + align:start position:0% +it in here without changing the angle + + + align:start position:0% +it in here without changing the angle +you can see I'm going to sample some of + + align:start position:0% +you can see I'm going to sample some of + + + align:start position:0% +you can see I'm going to sample some of +the light and you'll see it on on this + + align:start position:0% +the light and you'll see it on on this + + + align:start position:0% +the light and you'll see it on on this +on this screen and note that the word + + align:start position:0% +on this screen and note that the word + + + align:start position:0% +on this screen and note that the word +inside here that means that this piece + + align:start position:0% +inside here that means that this piece + + + align:start position:0% +inside here that means that this piece +of glass is inside the laser cavity and + + align:start position:0% +of glass is inside the laser cavity and + + + align:start position:0% +of glass is inside the laser cavity and +then one outside the laser cavity is + + align:start position:0% +then one outside the laser cavity is + + + align:start position:0% +then one outside the laser cavity is +labeled again by the word outside and + + align:start position:0% +labeled again by the word outside and + + + align:start position:0% +labeled again by the word outside and +now I want I would like you to look at + + align:start position:0% +now I want I would like you to look at + + + align:start position:0% +now I want I would like you to look at +at the spot reflected by the piece of + + align:start position:0% +at the spot reflected by the piece of + + + align:start position:0% +at the spot reflected by the piece of +glass outside the cavity and the spot + + align:start position:0% +glass outside the cavity and the spot + + + align:start position:0% +glass outside the cavity and the spot +reflected by the piece of glass inside + + align:start position:0% +reflected by the piece of glass inside + + + align:start position:0% +reflected by the piece of glass inside +the cavity so if we have now the split + + align:start position:0% +the cavity so if we have now the split + + + align:start position:0% +the cavity so if we have now the split +screen in position you can see that the + + align:start position:0% +screen in position you can see that the + + + align:start position:0% +screen in position you can see that the +one inside is much brighter than than + + align:start position:0% +one inside is much brighter than than + + + align:start position:0% +one inside is much brighter than than +the one outside in fact it's brighter in + + align:start position:0% +the one outside in fact it's brighter in + + + align:start position:0% +the one outside in fact it's brighter in +this case by about a factor of 50 or so + + align:start position:0% +this case by about a factor of 50 or so + + + align:start position:0% +this case by about a factor of 50 or so +the question I want to leave with you is + + align:start position:0% +the question I want to leave with you is + + + align:start position:0% +the question I want to leave with you is +it why the light coming out of the laser + + align:start position:0% +it why the light coming out of the laser + + + align:start position:0% +it why the light coming out of the laser +is much weaker than the light inside the + + align:start position:0% +is much weaker than the light inside the + + + align:start position:0% +is much weaker than the light inside the +laser and what determines that ratio so + + align:start position:0% +laser and what determines that ratio so + + + align:start position:0% +laser and what determines that ratio so +that's a nice little puzzle for you now + + align:start position:0% +that's a nice little puzzle for you now + + + align:start position:0% +that's a nice little puzzle for you now +sometimes one would like to increase the + + align:start position:0% +sometimes one would like to increase the + + + align:start position:0% +sometimes one would like to increase the +light coming out of the laser now how + + align:start position:0% +light coming out of the laser now how + + + align:start position:0% +light coming out of the laser now how +can you do it well you notice that since + + align:start position:0% +can you do it well you notice that since + + + align:start position:0% +can you do it well you notice that since +there's a lot of light inside the cavity + + align:start position:0% +there's a lot of light inside the cavity + + + align:start position:0% +there's a lot of light inside the cavity +one way of quickly increasing the laser + + align:start position:0% +one way of quickly increasing the laser + + + align:start position:0% +one way of quickly increasing the laser +intensity even though for a very short + + align:start position:0% +intensity even though for a very short + + + align:start position:0% +intensity even though for a very short +time is by removing one of the mirrors + + align:start position:0% +time is by removing one of the mirrors + + + align:start position:0% +time is by removing one of the mirrors +and like for example if I take this + + align:start position:0% +and like for example if I take this + + + align:start position:0% +and like for example if I take this +mirror out from the laser very quickly + + align:start position:0% +mirror out from the laser very quickly + + + align:start position:0% +mirror out from the laser very quickly +then I can essentially dump out all the + + align:start position:0% +then I can essentially dump out all the + + + align:start position:0% +then I can essentially dump out all the +photons that are stored in the laser + + align:start position:0% +photons that are stored in the laser + + + align:start position:0% +photons that are stored in the laser +cavity in fact this is called cavity + + align:start position:0% +cavity in fact this is called cavity + + + align:start position:0% +cavity in fact this is called cavity +dumping and what this gives you this + + align:start position:0% +dumping and what this gives you this + + + align:start position:0% +dumping and what this gives you this +gives you a huge increase in the + + align:start position:0% +gives you a huge increase in the + + + align:start position:0% +gives you a huge increase in the +number of photons coming out from the + + align:start position:0% +number of photons coming out from the + + + align:start position:0% +number of photons coming out from the +laser but only for a very short time in + + align:start position:0% +laser but only for a very short time in + + + align:start position:0% +laser but only for a very short time in +fact it just takes all the photon the + + align:start position:0% +fact it just takes all the photon the + + + align:start position:0% +fact it just takes all the photon the +stored in the laser cavity and just + + align:start position:0% +stored in the laser cavity and just + + + align:start position:0% +stored in the laser cavity and just +dumps them out and for of course for + + align:start position:0% +dumps them out and for of course for + + + align:start position:0% +dumps them out and for of course for +very short time in fact the time is just + + align:start position:0% +very short time in fact the time is just + + + align:start position:0% +very short time in fact the time is just +the twice the time that you go the + + align:start position:0% +the twice the time that you go the + + + align:start position:0% +the twice the time that you go the +transit time of the of the cabot so the + + align:start position:0% +transit time of the of the cabot so the + + + align:start position:0% +transit time of the of the cabot so the +fact that one knows something about the + + align:start position:0% +fact that one knows something about the + + + align:start position:0% +fact that one knows something about the +light inside the laser is big in the + + align:start position:0% +light inside the laser is big in the + + + align:start position:0% +light inside the laser is big in the +light outside the laser then one can + + align:start position:0% +light outside the laser then one can + + + align:start position:0% +light outside the laser then one can +come up with this concept of cavity + + align:start position:0% +come up with this concept of cavity + + + align:start position:0% +come up with this concept of cavity +dumping which which can be useful for + + align:start position:0% +dumping which which can be useful for + + + align:start position:0% +dumping which which can be useful for +some applications \ No newline at end of file diff --git a/eBkhAL-0l50.txt b/eBkhAL-0l50.txt new file mode 100644 index 0000000000000000000000000000000000000000..42b221427d0459444539cdcbcb7f36170ebbfcc7 --- /dev/null +++ b/eBkhAL-0l50.txt @@ -0,0 +1,13051 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu like to do today is continue + + align:start position:0% +ocw.mit.edu like to do today is continue + + + align:start position:0% +ocw.mit.edu like to do today is continue +a bit with a survey of third order uh + + align:start position:0% +a bit with a survey of third order uh + + + align:start position:0% +a bit with a survey of third order uh +spectroscopies um little little bit uh + + align:start position:0% +spectroscopies um little little bit uh + + + align:start position:0% +spectroscopies um little little bit uh +faster little fewer equations um just to + + align:start position:0% +faster little fewer equations um just to + + + align:start position:0% +faster little fewer equations um just to +give you a feeling for what uh we do + + align:start position:0% +give you a feeling for what uh we do + + + align:start position:0% +give you a feeling for what uh we do +with them but so third order just uh + + align:start position:0% +with them but so third order just uh + + + align:start position:0% +with them but so third order just uh +from last time remember if you do a + + align:start position:0% +from last time remember if you do a + + + align:start position:0% +from last time remember if you do a +nonlinear spectroscopy or you're not + + align:start position:0% +nonlinear spectroscopy or you're not + + + align:start position:0% +nonlinear spectroscopy or you're not +sure but you think you + + align:start position:0% +sure but you think you + + + align:start position:0% +sure but you think you +do chances are you're doing a third + + align:start position:0% +do chances are you're doing a third + + + align:start position:0% +do chances are you're doing a third +order nonlinear experiment so it + + align:start position:0% +order nonlinear experiment so it + + + align:start position:0% +order nonlinear experiment so it +um also known as four-wave + + align:start position:0% + + + + align:start position:0% + +mixing it's um basically all of the + + align:start position:0% +mixing it's um basically all of the + + + align:start position:0% +mixing it's um basically all of the +coherent Ultra fast spectroscopies you + + align:start position:0% +coherent Ultra fast spectroscopies you + + + align:start position:0% +coherent Ultra fast spectroscopies you +know 90% of them fall into this class um + + align:start position:0% +know 90% of them fall into this class um + + + align:start position:0% +know 90% of them fall into this class um +so we're talking + + align:start position:0% +so we're talking + + + align:start position:0% +so we're talking +about things + + align:start position:0% +about things + + + align:start position:0% +about things +like Photon + + align:start position:0% +like Photon + + + align:start position:0% +like Photon +Echoes transient grade + + align:start position:0% + + + + align:start position:0% + +gradings + + align:start position:0% +gradings + + + align:start position:0% +gradings +um all of the standard uh pump probe or + + align:start position:0% +um all of the standard uh pump probe or + + + align:start position:0% +um all of the standard uh pump probe or +transient absorption experim + + align:start position:0% +transient absorption experim + + + align:start position:0% +transient absorption experim +experiments whether you do that with + + align:start position:0% +experiments whether you do that with + + + align:start position:0% +experiments whether you do that with +coherent detection or + + align:start position:0% + + + + align:start position:0% + +incoherent + + align:start position:0% +incoherent + + + align:start position:0% +incoherent +um basically 90% of all of the uh + + align:start position:0% +um basically 90% of all of the uh + + + align:start position:0% +um basically 90% of all of the uh +two-dimensional spectroscopies that are + + align:start position:0% +two-dimensional spectroscopies that are + + + align:start position:0% +two-dimensional spectroscopies that are +being used these + + align:start position:0% +being used these + + + align:start position:0% +being used these +days + + align:start position:0% + + + + align:start position:0% + +CR can't write and talk at the same time + + align:start position:0% +CR can't write and talk at the same time + + + align:start position:0% +CR can't write and talk at the same time +um and there there's a few other example + + align:start position:0% +um and there there's a few other example + + + align:start position:0% +um and there there's a few other example +so I I want to go through some of these + + align:start position:0% +so I I want to go through some of these + + + align:start position:0% +so I I want to go through some of these +just to kind of give you a feeling for + + align:start position:0% +just to kind of give you a feeling for + + + align:start position:0% +just to kind of give you a feeling for +how they're all held together and + + align:start position:0% +how they're all held together and + + + align:start position:0% +how they're all held together and +they're all related to one another + + align:start position:0% +they're all related to one another + + + align:start position:0% +they're all related to one another +through these third order nonlinear + + align:start position:0% +through these third order nonlinear + + + align:start position:0% +through these third order nonlinear +response function yeah does anyone do + + align:start position:0% +response function yeah does anyone do + + + align:start position:0% +response function yeah does anyone do +second order stuff on nonent + + align:start position:0% +second order stuff on nonent + + + align:start position:0% +second order stuff on nonent +symmetric so + + align:start position:0% +symmetric so + + + align:start position:0% +symmetric so +that uh well the the classic example is + + align:start position:0% +that uh well the the classic example is + + + align:start position:0% +that uh well the the classic example is +uh surface selective experiments where + + align:start position:0% +uh surface selective experiments where + + + align:start position:0% +uh surface selective experiments where +you're making use of the surface to + + align:start position:0% +you're making use of the surface to + + + align:start position:0% +you're making use of the surface to +break the Symmetry um and and look for + + align:start position:0% +break the Symmetry um and and look for + + + align:start position:0% +break the Symmetry um and and look for +surface selective things um but it it is + + align:start position:0% +surface selective things um but it it is + + + align:start position:0% +surface selective things um but it it is +true you could absolutely do nonlinear + + align:start position:0% +true you could absolutely do nonlinear + + + align:start position:0% +true you could absolutely do nonlinear +stuff at at second order in a non- + + align:start position:0% +stuff at at second order in a non- + + + align:start position:0% +stuff at at second order in a non- +Centro symmetric + + align:start position:0% +Centro symmetric + + + align:start position:0% +Centro symmetric +medium but uh just because that's + + align:start position:0% +medium but uh just because that's + + + align:start position:0% +medium but uh just because that's +relatively rare and also bloody hard to + + align:start position:0% +relatively rare and also bloody hard to + + + align:start position:0% +relatively rare and also bloody hard to +do um most people don't do + + align:start position:0% +do um most people don't do + + + align:start position:0% +do um most people don't do +it oh + + align:start position:0% +it oh + + + align:start position:0% +it oh +um okay so last time we talked a bit + + align:start position:0% +um okay so last time we talked a bit + + + align:start position:0% +um okay so last time we talked a bit +about uh Photon Echoes um but sort of + + align:start position:0% +about uh Photon Echoes um but sort of + + + align:start position:0% +about uh Photon Echoes um but sort of +what I'm hoping oh yeah and the other + + align:start position:0% +what I'm hoping oh yeah and the other + + + align:start position:0% +what I'm hoping oh yeah and the other +big + + align:start position:0% +big + + + align:start position:0% +big +class are coherent Ramen + + align:start position:0% + + + + align:start position:0% + +spectroscopies and that refers to many + + align:start position:0% +spectroscopies and that refers to many + + + align:start position:0% +spectroscopies and that refers to many +different sorts of + + align:start position:0% +different sorts of + + + align:start position:0% +different sorts of +things um okay so I I'd like to keep + + align:start position:0% +things um okay so I I'd like to keep + + + align:start position:0% +things um okay so I I'd like to keep +going through this list a little bit and + + align:start position:0% +going through this list a little bit and + + + align:start position:0% +going through this list a little bit and +try and tie them all together we talked + + align:start position:0% +try and tie them all together we talked + + + align:start position:0% +try and tie them all together we talked +about Photon Echoes and the ability + + align:start position:0% +about Photon Echoes and the ability + + + align:start position:0% +about Photon Echoes and the ability +there to um talk about heterogene in a + + align:start position:0% +there to um talk about heterogene in a + + + align:start position:0% +there to um talk about heterogene in a +sample um using the rephasing + + align:start position:0% +sample um using the rephasing + + + align:start position:0% +sample um using the rephasing +characteristics of some of the + + align:start position:0% +characteristics of some of the + + + align:start position:0% +characteristics of some of the +correlation functions that contribute to + + align:start position:0% +correlation functions that contribute to + + + align:start position:0% +correlation functions that contribute to +the third order response let's um pick + + align:start position:0% +the third order response let's um pick + + + align:start position:0% +the third order response let's um pick +it up now with transient gradings um + + align:start position:0% +it up now with transient gradings um + + + align:start position:0% +it up now with transient gradings um +transient gradings that are great + + align:start position:0% +transient gradings that are great + + + align:start position:0% +transient gradings that are great +experiments because they have a very + + align:start position:0% +experiments because they have a very + + + align:start position:0% +experiments because they have a very +nice physical picture um that goes along + + align:start position:0% +nice physical picture um that goes along + + + align:start position:0% +nice physical picture um that goes along +with them so just to review for a second + + align:start position:0% +with them so just to review for a second + + + align:start position:0% +with them so just to review for a second +um we're talking about + + align:start position:0% +um we're talking about + + + align:start position:0% +um we're talking about +degenerate uh four-wave mixing at the + + align:start position:0% +degenerate uh four-wave mixing at the + + + align:start position:0% +degenerate uh four-wave mixing at the +moment um all the colors are the same + + align:start position:0% +moment um all the colors are the same + + + align:start position:0% +moment um all the colors are the same +it's very commonly performed in this box + + align:start position:0% +it's very commonly performed in this box + + + align:start position:0% +it's very commonly performed in this box +geometry + + align:start position:0% +geometry + + + align:start position:0% +geometry +we generate a signal in the fourth + + align:start position:0% +we generate a signal in the fourth + + + align:start position:0% +we generate a signal in the fourth +corner of a box that dictates a + + align:start position:0% +corner of a box that dictates a + + + align:start position:0% +corner of a box that dictates a +particular phase matching condition and + + align:start position:0% +particular phase matching condition and + + + align:start position:0% +particular phase matching condition and +we then can control the timing to sort + + align:start position:0% +we then can control the timing to sort + + + align:start position:0% +we then can control the timing to sort +of Select uh different + + align:start position:0% +of Select uh different + + + align:start position:0% +of Select uh different +contributions okay so the transient + + align:start position:0% +contributions okay so the transient + + + align:start position:0% +contributions okay so the transient +grading refers to the specific case + + align:start position:0% +grading refers to the specific case + + + align:start position:0% +grading refers to the specific case +where the first two fields are time + + align:start position:0% +where the first two fields are time + + + align:start position:0% +where the first two fields are time +coincident and they um they act as a + + align:start position:0% +coincident and they um they act as a + + + align:start position:0% +coincident and they um they act as a +pulse pair that is a pump field and + + align:start position:0% +pulse pair that is a pump field and + + + align:start position:0% +pulse pair that is a pump field and +there's a time delayed uh probe field + + align:start position:0% +there's a time delayed uh probe field + + + align:start position:0% +there's a time delayed uh probe field +okay um so what we're talking about is + + align:start position:0% +okay um so what we're talking about is + + + align:start position:0% +okay um so what we're talking about is +um we're going to generate a signal in + + align:start position:0% +um we're going to generate a signal in + + + align:start position:0% +um we're going to generate a signal in +one corner of the box and uh any + + align:start position:0% +one corner of the box and uh any + + + align:start position:0% +one corner of the box and uh any +adjacent pair of these beams are going + + align:start position:0% +adjacent pair of these beams are going + + + align:start position:0% +adjacent pair of these beams are going +to be timed up with one another um we'll + + align:start position:0% +to be timed up with one another um we'll + + + align:start position:0% +to be timed up with one another um we'll +call them one and two but in practice + + align:start position:0% +call them one and two but in practice + + + align:start position:0% +call them one and two but in practice +because they're time coincident you + + align:start position:0% +because they're time coincident you + + + align:start position:0% +because they're time coincident you +can't distinguish which is first and + + align:start position:0% +can't distinguish which is first and + + + align:start position:0% +can't distinguish which is first and +which is second we'll just call those uh + + align:start position:0% +which is second we'll just call those uh + + + align:start position:0% +which is second we'll just call those uh +I guess we could call them pump + + align:start position:0% +I guess we could call them pump + + + align:start position:0% +I guess we could call them pump +um and then there's a + + align:start position:0% + + + + align:start position:0% + +probe and if you now work through all of + + align:start position:0% +probe and if you now work through all of + + + align:start position:0% +probe and if you now work through all of +the + + align:start position:0% +the + + + align:start position:0% +the +uh processes that will contribute to + + align:start position:0% +uh processes that will contribute to + + + align:start position:0% +uh processes that will contribute to +this you well the first thing you + + align:start position:0% +this you well the first thing you + + + align:start position:0% +this you well the first thing you +realize is the time variable that you + + align:start position:0% +realize is the time variable that you + + + align:start position:0% +realize is the time variable that you +have control over is after the second + + align:start position:0% +have control over is after the second + + + align:start position:0% +have control over is after the second +interaction with the light and of the + + align:start position:0% +interaction with the light and of the + + + align:start position:0% +interaction with the light and of the +light with the matter and so in your + + align:start position:0% +light with the matter and so in your + + + align:start position:0% +light with the matter and so in your +response functions you're looking at the + + align:start position:0% +response functions you're looking at the + + + align:start position:0% +response functions you're looking at the +t2 variable and that typic has many + + align:start position:0% +t2 variable and that typic has many + + + align:start position:0% +t2 variable and that typic has many +contributions we'll talk about those but + + align:start position:0% +contributions we'll talk about those but + + + align:start position:0% +contributions we'll talk about those but +um what you're doing is looking at + + align:start position:0% +um what you're doing is looking at + + + align:start position:0% +um what you're doing is looking at +relaxation of whatever um + + align:start position:0% +relaxation of whatever um + + + align:start position:0% +relaxation of whatever um +happens uh upon you exitation with that + + align:start position:0% +happens uh upon you exitation with that + + + align:start position:0% +happens uh upon you exitation with that +pulse pair okay so the the nice thing + + align:start position:0% +pulse pair okay so the the nice thing + + + align:start position:0% +pulse pair okay so the the nice thing +about transient gradings is that uh you + + align:start position:0% +about transient gradings is that uh you + + + align:start position:0% +about transient gradings is that uh you +should recognize that when you have two + + align:start position:0% +should recognize that when you have two + + + align:start position:0% +should recognize that when you have two +Fields where the wave fronts you know + + align:start position:0% +Fields where the wave fronts you know + + + align:start position:0% +Fields where the wave fronts you know +are + + align:start position:0% +are + + + align:start position:0% +are +perpendicular to the direction of + + align:start position:0% +perpendicular to the direction of + + + align:start position:0% +perpendicular to the direction of +propagation and you cross these + + align:start position:0% +propagation and you cross these + + + align:start position:0% +propagation and you cross these +simultaneously in a sample + + align:start position:0% + + + + align:start position:0% + +that one has + + align:start position:0% +that one has + + + align:start position:0% +that one has +um constructive and destructive + + align:start position:0% +um constructive and destructive + + + align:start position:0% +um constructive and destructive +interference in the crossing area and + + align:start position:0% +interference in the crossing area and + + + align:start position:0% +interference in the crossing area and +you can think about this by sort of + + align:start position:0% +you can think about this by sort of + + + align:start position:0% +you can think about this by sort of +writing out the product of those fields + + align:start position:0% +writing out the product of those fields + + + align:start position:0% +writing out the product of those fields +and it'll look sort of like a magnitude + + align:start position:0% +and it'll look sort of like a magnitude + + + align:start position:0% +and it'll look sort of like a magnitude +and + + align:start position:0% +and + + + align:start position:0% +and +um something like + + align:start position:0% +um something like + + + align:start position:0% +um something like +uh + + align:start position:0% +uh + + + align:start position:0% +uh +cosine Omega 1 - Omega + + align:start position:0% +cosine Omega 1 - Omega + + + align:start position:0% +cosine Omega 1 - Omega +2 t + + align:start position:0% +2 t + + + align:start position:0% +2 t +- + + align:start position:0% +- + + + align:start position:0% +- +k um K1 - + + align:start position:0% +k um K1 - + + + align:start position:0% +k um K1 - +K2 + + align:start position:0% +K2 + + + align:start position:0% +K2 +R hope I got that right let me see but + + align:start position:0% +R hope I got that right let me see but + + + align:start position:0% +R hope I got that right let me see but +in any case what you have is yeah let me + + align:start position:0% +in any case what you have is yeah let me + + + align:start position:0% +in any case what you have is yeah let me +just write + + align:start position:0% +just write + + + align:start position:0% +just write +it just to make sure I don't screw + + align:start position:0% +it just to make sure I don't screw + + + align:start position:0% +it just to make sure I don't screw +anything + + align:start position:0% +anything + + + align:start position:0% +anything +up + + align:start position:0% + + + + align:start position:0% + +xpi the what you have is both a you have + + align:start position:0% +xpi the what you have is both a you have + + + align:start position:0% +xpi the what you have is both a you have +a spa variation of the intensity and + + align:start position:0% +a spa variation of the intensity and + + + align:start position:0% +a spa variation of the intensity and +phase pattern in the sample over here + + align:start position:0% +phase pattern in the sample over here + + + align:start position:0% +phase pattern in the sample over here +okay that's encoded over here so K1 + + align:start position:0% +okay that's encoded over here so K1 + + + align:start position:0% +okay that's encoded over here so K1 +minus K2 the difference in the wave + + align:start position:0% +minus K2 the difference in the wave + + + align:start position:0% +minus K2 the difference in the wave +vectors for the two incident + + align:start position:0% +vectors for the two incident + + + align:start position:0% +vectors for the two incident +pumps uh lies uh perpendicular to this + + align:start position:0% +pumps uh lies uh perpendicular to this + + + align:start position:0% +pumps uh lies uh perpendicular to this +direction which you're cross you know + + align:start position:0% +direction which you're cross you know + + + align:start position:0% +direction which you're cross you know +propagating the beams and it's an + + align:start position:0% +propagating the beams and it's an + + + align:start position:0% +propagating the beams and it's an +interference + + align:start position:0% +interference + + + align:start position:0% +interference +pattern which if you think about it as + + align:start position:0% +pattern which if you think about it as + + + align:start position:0% +pattern which if you think about it as +intensity would be sort of a light dark + + align:start position:0% +intensity would be sort of a light dark + + + align:start position:0% +intensity would be sort of a light dark +light dark pattern um but at the same + + align:start position:0% +light dark pattern um but at the same + + + align:start position:0% +light dark pattern um but at the same +time it's also a phase variation at the + + align:start position:0% +time it's also a phase variation at the + + + align:start position:0% +time it's also a phase variation at the +field + + align:start position:0% +field + + + align:start position:0% +field +level and uh this is the pattern that + + align:start position:0% +level and uh this is the pattern that + + + align:start position:0% +level and uh this is the pattern that +gets imaged into your sample through the + + align:start position:0% +gets imaged into your sample through the + + + align:start position:0% +gets imaged into your sample through the +light matter interaction so if we're + + align:start position:0% +light matter interaction so if we're + + + align:start position:0% +light matter interaction so if we're +talking just about exciting population + + align:start position:0% +talking just about exciting population + + + align:start position:0% +talking just about exciting population +we're saying that we're going to create + + align:start position:0% +we're saying that we're going to create + + + align:start position:0% +we're saying that we're going to create +a spatial variation of + + align:start position:0% +a spatial variation of + + + align:start position:0% +a spatial variation of +populations uh that are excited and so + + align:start position:0% +populations uh that are excited and so + + + align:start position:0% +populations uh that are excited and so +by Imaging that Optical p pattern into + + align:start position:0% +by Imaging that Optical p pattern into + + + align:start position:0% +by Imaging that Optical p pattern into +the sample what you've done is uh + + align:start position:0% +the sample what you've done is uh + + + align:start position:0% +the sample what you've done is uh +created a grading right it's a spatial + + align:start position:0% +created a grading right it's a spatial + + + align:start position:0% +created a grading right it's a spatial +variation of the complex index of + + align:start position:0% +variation of the complex index of + + + align:start position:0% +variation of the complex index of +refraction so they're both the + + align:start position:0% +refraction so they're both the + + + align:start position:0% +refraction so they're both the +absorptive and the dispersive parts okay + + align:start position:0% +absorptive and the dispersive parts okay + + + align:start position:0% +absorptive and the dispersive parts okay +um the nice thing you have is uh you've + + align:start position:0% +um the nice thing you have is uh you've + + + align:start position:0% +um the nice thing you have is uh you've +have control over the grading wave + + align:start position:0% +have control over the grading wave + + + align:start position:0% +have control over the grading wave +Vector because that's really just + + align:start position:0% +Vector because that's really just + + + align:start position:0% +Vector because that's really just +dictated by The Crossing angle so as + + align:start position:0% +dictated by The Crossing angle so as + + + align:start position:0% +dictated by The Crossing angle so as +I've pointed out here if you um Cross by + + align:start position:0% +I've pointed out here if you um Cross by + + + align:start position:0% +I've pointed out here if you um Cross by +an angle to Theta then the um grading + + align:start position:0% +an angle to Theta then the um grading + + + align:start position:0% +an angle to Theta then the um grading +Fringe spacing is uh you know dictated + + align:start position:0% +Fringe spacing is uh you know dictated + + + align:start position:0% +Fringe spacing is uh you know dictated +by the wavelength of the light and the + + align:start position:0% +by the wavelength of the light and the + + + align:start position:0% +by the wavelength of the light and the +sign of the crossing angles of written + + align:start position:0% +sign of the crossing angles of written + + + align:start position:0% +sign of the crossing angles of written +up there okay um so this turns out to be + + align:start position:0% +up there okay um so this turns out to be + + + align:start position:0% +up there okay um so this turns out to be +very effective uh particularly if you're + + align:start position:0% +very effective uh particularly if you're + + + align:start position:0% +very effective uh particularly if you're +interested in watching um relaxation + + align:start position:0% +interested in watching um relaxation + + + align:start position:0% +interested in watching um relaxation +processes on spatial scales you + + align:start position:0% +processes on spatial scales you + + + align:start position:0% +processes on spatial scales you +know uh of optical you know the optical + + align:start position:0% +know uh of optical you know the optical + + + align:start position:0% +know uh of optical you know the optical +wavelength range okay so um y + + align:start position:0% +wavelength range okay so um y + + + align:start position:0% +wavelength range okay so um y +does anyone able to do microscopy on + + align:start position:0% +does anyone able to do microscopy on + + + align:start position:0% +does anyone able to do microscopy on +that like image that y uh I think a good + + align:start position:0% +that like image that y uh I think a good + + + align:start position:0% +that like image that y uh I think a good +great example is what Andy Marcus does + + align:start position:0% +great example is what Andy Marcus does + + + align:start position:0% +great example is what Andy Marcus does +at Oregon he there he's really trying to + + align:start position:0% +at Oregon he there he's really trying to + + + align:start position:0% +at Oregon he there he's really trying to +look at anisotropic diffusion um you + + align:start position:0% +look at anisotropic diffusion um you + + + align:start position:0% +look at anisotropic diffusion um you +know perpendicular and parallel to + + align:start position:0% +know perpendicular and parallel to + + + align:start position:0% +know perpendicular and parallel to +fringes in an you know Optical uh + + align:start position:0% +fringes in an you know Optical uh + + + align:start position:0% +fringes in an you know Optical uh +grading + + align:start position:0% +grading + + + align:start position:0% +grading +yeah it's uh sort of the trans um you + + align:start position:0% +yeah it's uh sort of the trans um you + + + align:start position:0% +yeah it's uh sort of the trans um you +transient gradings + + align:start position:0% +transient gradings + + + align:start position:0% +transient gradings +are pretty much analogous to pump probe + + align:start position:0% +are pretty much analogous to pump probe + + + align:start position:0% +are pretty much analogous to pump probe +experiments they are sort of the limit + + align:start position:0% +experiments they are sort of the limit + + + align:start position:0% +experiments they are sort of the limit +that the crossing angle goes to zero and + + align:start position:0% +that the crossing angle goes to zero and + + + align:start position:0% +that the crossing angle goes to zero and +uh the fix experiments that Andy does + + align:start position:0% +uh the fix experiments that Andy does + + + align:start position:0% +uh the fix experiments that Andy does +are functionally the transient grading + + align:start position:0% +are functionally the transient grading + + + align:start position:0% +are functionally the transient grading +version of what uh uh + + align:start position:0% + + + + align:start position:0% + +it fix is to fluoresence correlation + + align:start position:0% +it fix is to fluoresence correlation + + + align:start position:0% +it fix is to fluoresence correlation +spectroscopy what transient gradings are + + align:start position:0% +spectroscopy what transient gradings are + + + align:start position:0% +spectroscopy what transient gradings are +to pump probe experiments if that makes + + align:start position:0% +to pump probe experiments if that makes + + + align:start position:0% +to pump probe experiments if that makes +sense it's the same kind of technique + + align:start position:0% +sense it's the same kind of technique + + + align:start position:0% +sense it's the same kind of technique +but you're making use of this spatial + + align:start position:0% +but you're making use of this spatial + + + align:start position:0% +but you're making use of this spatial +variation to tell you about anisotropic + + align:start position:0% + + + + align:start position:0% + +Behavior okay so but uh now as you can + + align:start position:0% +Behavior okay so but uh now as you can + + + align:start position:0% +Behavior okay so but uh now as you can +imagine there's all sorts of ways in + + align:start position:0% +imagine there's all sorts of ways in + + + align:start position:0% +imagine there's all sorts of ways in +which this grading can relax you know + + align:start position:0% +which this grading can relax you know + + + align:start position:0% +which this grading can relax you know +what I failed to point out is okay + + align:start position:0% +what I failed to point out is okay + + + align:start position:0% +what I failed to point out is okay +you've imaged a grading into the sample + + align:start position:0% +you've imaged a grading into the sample + + + align:start position:0% +you've imaged a grading into the sample +and now what you can think of is that + + align:start position:0% +and now what you can think of is that + + + align:start position:0% +and now what you can think of is that +the probe pulse is something that um + + align:start position:0% +the probe pulse is something that um + + + align:start position:0% +the probe pulse is something that um +defract off of that grading that the + + align:start position:0% +defract off of that grading that the + + + align:start position:0% +defract off of that grading that the +efficiency of light scattered off of + + align:start position:0% +efficiency of light scattered off of + + + align:start position:0% +efficiency of light scattered off of +that grading is what you were measuring + + align:start position:0% +that grading is what you were measuring + + + align:start position:0% +that grading is what you were measuring +measuring in a transient grading + + align:start position:0% +measuring in a transient grading + + + align:start position:0% +measuring in a transient grading +experiment so that um that's sort of the + + align:start position:0% +experiment so that um that's sort of the + + + align:start position:0% +experiment so that um that's sort of the +physical picture that goes with it and + + align:start position:0% +physical picture that goes with it and + + + align:start position:0% +physical picture that goes with it and +you can imagine a bunch of different + + align:start position:0% +you can imagine a bunch of different + + + align:start position:0% +you can imagine a bunch of different +types of relaxation processes if you're + + align:start position:0% +types of relaxation processes if you're + + + align:start position:0% +types of relaxation processes if you're +just looking at relaxation of uh excited + + align:start position:0% +just looking at relaxation of uh excited + + + align:start position:0% +just looking at relaxation of uh excited +States this is the amplitude of that + + align:start position:0% +States this is the amplitude of that + + + align:start position:0% +States this is the amplitude of that +grading gradually washing out with time + + align:start position:0% +grading gradually washing out with time + + + align:start position:0% +grading gradually washing out with time +and you know you can imagine that that + + align:start position:0% +and you know you can imagine that that + + + align:start position:0% +and you know you can imagine that that +would lead to a um signal where the + + align:start position:0% +would lead to a um signal where the + + + align:start position:0% +would lead to a um signal where the +scattering efficiency just uh decreases + + align:start position:0% +scattering efficiency just uh decreases + + + align:start position:0% +scattering efficiency just uh decreases +with the relaxation processes + + align:start position:0% +with the relaxation processes + + + align:start position:0% +with the relaxation processes +it's also possible that um if this + + align:start position:0% +it's also possible that um if this + + + align:start position:0% +it's also possible that um if this +grading is imaged rapidly that you can + + align:start position:0% +grading is imaged rapidly that you can + + + align:start position:0% +grading is imaged rapidly that you can +jump + + align:start position:0% +jump + + + align:start position:0% +jump +the index in you know functionally + + align:start position:0% +the index in you know functionally + + + align:start position:0% +the index in you know functionally +heating or expanding the material in the + + align:start position:0% +heating or expanding the material in the + + + align:start position:0% +heating or expanding the material in the +high-intensity regions and you can + + align:start position:0% +high-intensity regions and you can + + + align:start position:0% +high-intensity regions and you can +launch acoustic waves that propagate + + align:start position:0% +launch acoustic waves that propagate + + + align:start position:0% +launch acoustic waves that propagate +counter propagate actually through the + + align:start position:0% +counter propagate actually through the + + + align:start position:0% +counter propagate actually through the +sample um and as you might imagine that + + align:start position:0% +sample um and as you might imagine that + + + align:start position:0% +sample um and as you might imagine that +will modulate the defraction efficiency + + align:start position:0% +will modulate the defraction efficiency + + + align:start position:0% +will modulate the defraction efficiency +as they move across and so that would uh + + align:start position:0% +as they move across and so that would uh + + + align:start position:0% +as they move across and so that would uh +typically you know show up as a + + align:start position:0% +typically you know show up as a + + + align:start position:0% +typically you know show up as a +modulation on you know on top of a + + align:start position:0% +modulation on you know on top of a + + + align:start position:0% +modulation on you know on top of a +relaxation + + align:start position:0% +relaxation + + + align:start position:0% +relaxation +process um time scale of course there is + + align:start position:0% +process um time scale of course there is + + + align:start position:0% +process um time scale of course there is +dictated by you know acoustic + + align:start position:0% +dictated by you know acoustic + + + align:start position:0% +dictated by you know acoustic +propagation so you're you know soft me + + align:start position:0% +propagation so you're you know soft me + + + align:start position:0% +propagation so you're you know soft me +to you're talking sort of nanc behavior + + align:start position:0% +to you're talking sort of nanc behavior + + + align:start position:0% +to you're talking sort of nanc behavior +usually um and then as you might imagine + + align:start position:0% +usually um and then as you might imagine + + + align:start position:0% +usually um and then as you might imagine +you can get look at very long um thermal + + align:start position:0% +you can get look at very long um thermal + + + align:start position:0% +you can get look at very long um thermal +relaxation processes you if you're + + align:start position:0% +relaxation processes you if you're + + + align:start position:0% +relaxation processes you if you're +really heating the system in these light + + align:start position:0% +really heating the system in these light + + + align:start position:0% +really heating the system in these light +spots then you've created a modulation + + align:start position:0% +spots then you've created a modulation + + + align:start position:0% +spots then you've created a modulation +in the index of refraction that because + + align:start position:0% +in the index of refraction that because + + + align:start position:0% +in the index of refraction that because +of the temperature dependence to that + + align:start position:0% +of the temperature dependence to that + + + align:start position:0% +of the temperature dependence to that +index and as that uh + + align:start position:0% +index and as that uh + + + align:start position:0% +index and as that uh +grading starts well defined and + + align:start position:0% +grading starts well defined and + + + align:start position:0% +grading starts well defined and +gradually washes + + align:start position:0% +gradually washes + + + align:start position:0% +gradually washes +out due to Thermal diffusion from Peaks + + align:start position:0% +out due to Thermal diffusion from Peaks + + + align:start position:0% +out due to Thermal diffusion from Peaks +into nulls that also contributes and so + + align:start position:0% +into nulls that also contributes and so + + + align:start position:0% +into nulls that also contributes and so +basically at the end of the day any sort + + align:start position:0% +basically at the end of the day any sort + + + align:start position:0% +basically at the end of the day any sort +of Transport process that has a um + + align:start position:0% +of Transport process that has a um + + + align:start position:0% +of Transport process that has a um +wavelength dependence to it or or a or a + + align:start position:0% +wavelength dependence to it or or a or a + + + align:start position:0% +wavelength dependence to it or or a or a +um intensity dependence to it uh that + + align:start position:0% +um intensity dependence to it uh that + + + align:start position:0% +um intensity dependence to it uh that +can be and that that it'll work on this + + align:start position:0% +can be and that that it'll work on this + + + align:start position:0% +can be and that that it'll work on this +distance scale of the optical wavelength + + align:start position:0% +distance scale of the optical wavelength + + + align:start position:0% +distance scale of the optical wavelength +you can probe that with transient + + align:start position:0% + + + + align:start position:0% + +gradings okay any questions on that + + align:start position:0% +gradings okay any questions on that + + + align:start position:0% +gradings okay any questions on that +one you ever do experiments where either + + align:start position:0% +one you ever do experiments where either + + + align:start position:0% +one you ever do experiments where either +the pump or probe in a transient gring + + align:start position:0% +the pump or probe in a transient gring + + + align:start position:0% +the pump or probe in a transient gring +is actually not so transient as the C A + + align:start position:0% +is actually not so transient as the C A + + + align:start position:0% +is actually not so transient as the C A +CW beam so you either have like a + + align:start position:0% +CW beam so you either have like a + + + align:start position:0% +CW beam so you either have like a +optical grading there and you image it + + align:start position:0% +optical grading there and you image it + + + align:start position:0% +optical grading there and you image it +with some transing probe or uh of + + align:start position:0% +with some transing probe or uh of + + + align:start position:0% +with some transing probe or uh of +actually Imaging the the grading + + align:start position:0% +actually Imaging the the grading + + + align:start position:0% +actually Imaging the the grading +itself I don't know I think we got to + + align:start position:0% +itself I don't know I think we got to + + + align:start position:0% +itself I don't know I think we got to +ask that to the Nelson folks I think you + + align:start position:0% +ask that to the Nelson folks I think you + + + align:start position:0% +ask that to the Nelson folks I think you +guys were doing something like that in + + align:start position:0% +guys were doing something like that in + + + align:start position:0% +guys were doing something like that in +that but it's not a CW no but not CW + + align:start position:0% +that but it's not a CW no but not CW + + + align:start position:0% +that but it's not a CW no but not CW +right yeah no it uh but this this is + + align:start position:0% +right yeah no it uh but this this is + + + align:start position:0% +right yeah no it uh but this this is +getting back a little bit to what Paul + + align:start position:0% +getting back a little bit to what Paul + + + align:start position:0% +getting back a little bit to what Paul +was asking earlier there you know you + + align:start position:0% +was asking earlier there you know you + + + align:start position:0% +was asking earlier there you know you +know there there are some microscopies + + align:start position:0% +know there there are some microscopies + + + align:start position:0% +know there there are some microscopies +in which you can really image the + + align:start position:0% +in which you can really image the + + + align:start position:0% +in which you can really image the +grading directly and um try and use it + + align:start position:0% +grading directly and um try and use it + + + align:start position:0% +grading directly and um try and use it +to distinguish diffusion of particles + + align:start position:0% +to distinguish diffusion of particles + + + align:start position:0% +to distinguish diffusion of particles +you know along the direction of The + + align:start position:0% +you know along the direction of The + + + align:start position:0% +you know along the direction of The +Fringe the the gring wave + + align:start position:0% +Fringe the the gring wave + + + align:start position:0% +Fringe the the gring wave +Vector U but no it's I mean the way you + + align:start position:0% +Vector U but no it's I mean the way you + + + align:start position:0% +Vector U but no it's I mean the way you +described it that's very + + align:start position:0% +described it that's very + + + align:start position:0% +described it that's very +uncommon but it's true you can just as + + align:start position:0% +uncommon but it's true you can just as + + + align:start position:0% +uncommon but it's true you can just as +well do this with uh CW beams but you at + + align:start position:0% +well do this with uh CW beams but you at + + + align:start position:0% +well do this with uh CW beams but you at +that moment you also want to recognize + + align:start position:0% +that moment you also want to recognize + + + align:start position:0% +that moment you also want to recognize +that there you can't enforce the kind of + + align:start position:0% +that there you can't enforce the kind of + + + align:start position:0% +that there you can't enforce the kind of +time ordering that we have here there's + + align:start position:0% +time ordering that we have here there's + + + align:start position:0% +time ordering that we have here there's +addition in addition to what I've + + align:start position:0% +addition in addition to what I've + + + align:start position:0% +addition in addition to what I've +described there will be additional + + align:start position:0% +described there will be additional + + + align:start position:0% +described there will be additional +relaxation processes that you know + + align:start position:0% +relaxation processes that you know + + + align:start position:0% +relaxation processes that you know +depend on um uh you know coherence that + + align:start position:0% +depend on um uh you know coherence that + + + align:start position:0% +depend on um uh you know coherence that +different here I've described it really + + align:start position:0% +different here I've described it really + + + align:start position:0% +different here I've described it really +all as incoherent relaxation processes + + align:start position:0% +all as incoherent relaxation processes + + + align:start position:0% +all as incoherent relaxation processes +right that now that's not uh like you + + align:start position:0% +right that now that's not uh like you + + + align:start position:0% +right that now that's not uh like you +know that's not entirely the case um and + + align:start position:0% +know that's not entirely the case um and + + + align:start position:0% +know that's not entirely the case um and +this is sort of getting uh toward + + align:start position:0% +this is sort of getting uh toward + + + align:start position:0% +this is sort of getting uh toward +coherent Ramen methods the other way to + + align:start position:0% +coherent Ramen methods the other way to + + + align:start position:0% +coherent Ramen methods the other way to +look at this is just because um The Wave + + align:start position:0% +look at this is just because um The Wave + + + align:start position:0% +look at this is just because um The Wave +Vector matching and the time + + align:start position:0% +Vector matching and the time + + + align:start position:0% +Vector matching and the time +ordering + + align:start position:0% +ordering + + + align:start position:0% +ordering +um says that there's a difference in + + align:start position:0% +um says that there's a difference in + + + align:start position:0% +um says that there's a difference in +wave Vector between the um difference in + + align:start position:0% +wave Vector between the um difference in + + + align:start position:0% +wave Vector between the um difference in +momentum between the first two + + align:start position:0% +momentum between the first two + + + align:start position:0% +momentum between the first two +interactions that also means that + + align:start position:0% +interactions that also means that + + + align:start position:0% +interactions that also means that +there's a difference in frequency um so + + align:start position:0% +there's a difference in frequency um so + + + align:start position:0% +there's a difference in frequency um so +for degenerate cases you know this uh + + align:start position:0% +for degenerate cases you know this uh + + + align:start position:0% +for degenerate cases you know this uh +disappears um if these are slightly + + align:start position:0% +disappears um if these are slightly + + + align:start position:0% +disappears um if these are slightly +different frequencies you have a you + + align:start position:0% +different frequencies you have a you + + + align:start position:0% +different frequencies you have a you +know um you can now imagine this + + align:start position:0% +know um you can now imagine this + + + align:start position:0% +know um you can now imagine this +experiment as a Ramen experiment where + + align:start position:0% +experiment as a Ramen experiment where + + + align:start position:0% +experiment as a Ramen experiment where +you're driving coherences at the + + align:start position:0% +you're driving coherences at the + + + align:start position:0% +you're driving coherences at the +difference frequency between the two + + align:start position:0% +difference frequency between the two + + + align:start position:0% +difference frequency between the two +incident fields that that creates a + + align:start position:0% +incident fields that that creates a + + + align:start position:0% +incident fields that that creates a +moving rating right it now moves in TI + + align:start position:0% +moving rating right it now moves in TI + + + align:start position:0% +moving rating right it now moves in TI +in + + align:start position:0% + + + + align:start position:0% + +space um yeah so we'll get to coherent + + align:start position:0% +space um yeah so we'll get to coherent + + + align:start position:0% +space um yeah so we'll get to coherent +romen a little bit but the the grading + + align:start position:0% +romen a little bit but the the grading + + + align:start position:0% +romen a little bit but the the grading +the um just one question + + align:start position:0% +the um just one question + + + align:start position:0% +the um just one question +so what if you make your grading out of + + align:start position:0% +so what if you make your grading out of + + + align:start position:0% +so what if you make your grading out of +more than two beans in particular if you + + align:start position:0% +more than two beans in particular if you + + + align:start position:0% +more than two beans in particular if you +want to make not a 1D grading but a + + align:start position:0% +want to make not a 1D grading but a + + + align:start position:0% +want to make not a 1D grading but a +m sure people is that something like + + align:start position:0% +m sure people is that something like + + + align:start position:0% +m sure people is that something like +it's actually + + align:start position:0% +it's actually + + + align:start position:0% +it's actually +possible um boy yes I mean people there + + align:start position:0% +possible um boy yes I mean people there + + + align:start position:0% +possible um boy yes I mean people there +there was a there was a time where + + align:start position:0% +there was a there was a time where + + + align:start position:0% +there was a there was a time where +people really talked a lot about + + align:start position:0% +people really talked a lot about + + + align:start position:0% +people really talked a lot about +holographic data storage you know with + + align:start position:0% +holographic data storage you know with + + + align:start position:0% +holographic data storage you know with +um many beams right and I don't know a + + align:start position:0% +um many beams right and I don't know a + + + align:start position:0% +um many beams right and I don't know a +heck of a lot about that but um that of + + align:start position:0% +heck of a lot about that but um that of + + + align:start position:0% +heck of a lot about that but um that of +course that would fall into a you know + + align:start position:0% +course that would fall into a you know + + + align:start position:0% +course that would fall into a you know +sort of another class light matter + + align:start position:0% +sort of another class light matter + + + align:start position:0% +sort of another class light matter +interactions you're going to need + + align:start position:0% +interactions you're going to need + + + align:start position:0% +interactions you're going to need +additional Fields but but it's right + + align:start position:0% +additional Fields but but it's right + + + align:start position:0% +additional Fields but but it's right +that's analogous it seemed like those + + align:start position:0% +that's analogous it seemed like those + + + align:start position:0% +that's analogous it seemed like those +things never actually got experimentally + + align:start position:0% +things never actually got experimentally + + + align:start position:0% +things never actually got experimentally +realized + + align:start position:0% +realized + + + align:start position:0% +realized +yeah experimentally is this really + + align:start position:0% +yeah experimentally is this really + + + align:start position:0% +yeah experimentally is this really +hard no that's no problem at all + + align:start position:0% + + + + align:start position:0% + +yeah okay so now let me turn to + + align:start position:0% +yeah okay so now let me turn to + + + align:start position:0% +yeah okay so now let me turn to +transient absorption I um I wanted to + + align:start position:0% +transient absorption I um I wanted to + + + align:start position:0% +transient absorption I um I wanted to +save this a little bit just to put a a + + align:start position:0% +save this a little bit just to put a a + + + align:start position:0% +save this a little bit just to put a a +slightly different spin on it what we're + + align:start position:0% +slightly different spin on it what we're + + + align:start position:0% +slightly different spin on it what we're +talking about now is really + + align:start position:0% +talking about now is really + + + align:start position:0% +talking about now is really +um any sort of an experiment where + + align:start position:0% +um any sort of an experiment where + + + align:start position:0% +um any sort of an experiment where +you're using two + + align:start position:0% +you're using two + + + align:start position:0% +you're using two +Fields driving the system waiting a + + align:start position:0% +Fields driving the system waiting a + + + align:start position:0% +Fields driving the system waiting a +period of time and then just watching + + align:start position:0% +period of time and then just watching + + + align:start position:0% +period of time and then just watching +the response so this is probably the + + align:start position:0% +the response so this is probably the + + + align:start position:0% +the response so this is probably the +most common type of an experiment and + + align:start position:0% +most common type of an experiment and + + + align:start position:0% +most common type of an experiment and +and I'm going to specifically talk about + + align:start position:0% +and I'm going to specifically talk about + + + align:start position:0% +and I'm going to specifically talk about +the case where you know I just crossed + + align:start position:0% +the case where you know I just crossed + + + align:start position:0% +the case where you know I just crossed +two beams I've got one that precedes the + + align:start position:0% +two beams I've got one that precedes the + + + align:start position:0% +two beams I've got one that precedes the +other I call the first pump and the + + align:start position:0% +other I call the first pump and the + + + align:start position:0% +other I call the first pump and the +second the probe there's one time delay + + align:start position:0% +second the probe there's one time delay + + + align:start position:0% +second the probe there's one time delay +between these two um and what I'm going + + align:start position:0% +between these two um and what I'm going + + + align:start position:0% +between these two um and what I'm going +to do is put a + + align:start position:0% +to do is put a + + + align:start position:0% +to do is put a +detector on the uh transmitted probe + + align:start position:0% +detector on the uh transmitted probe + + + align:start position:0% +detector on the uh transmitted probe +beam and I'm just interested in looking + + align:start position:0% +beam and I'm just interested in looking + + + align:start position:0% +beam and I'm just interested in looking +at the change in + + align:start position:0% +at the change in + + + align:start position:0% +at the change in +intensity that I see with and without + + align:start position:0% +intensity that I see with and without + + + align:start position:0% +intensity that I see with and without +the pump beam there + + align:start position:0% +the pump beam there + + + align:start position:0% +the pump beam there +okay um so this is is transient + + align:start position:0% +okay um so this is is transient + + + align:start position:0% +okay um so this is is transient +absorption um and what I'm talking about + + align:start position:0% +absorption um and what I'm talking about + + + align:start position:0% +absorption um and what I'm talking about +applies pretty much also to the other + + align:start position:0% +applies pretty much also to the other + + + align:start position:0% +applies pretty much also to the other +common case which is that + + align:start position:0% + + + + align:start position:0% + +um you're looking at spontaneous + + align:start position:0% +um you're looking at spontaneous + + + align:start position:0% +um you're looking at spontaneous +emission or or some sort of an + + align:start position:0% +emission or or some sort of an + + + align:start position:0% +emission or or some sort of an +incoherent + + align:start position:0% +incoherent + + + align:start position:0% +incoherent +process um from the sample and you're + + align:start position:0% +process um from the sample and you're + + + align:start position:0% +process um from the sample and you're +looking at the change of that scattered + + align:start position:0% +looking at the change of that scattered + + + align:start position:0% +looking at the change of that scattered +intensity as a result of these two + + align:start position:0% +intensity as a result of these two + + + align:start position:0% +intensity as a result of these two +interactions okay uh as we talked about + + align:start position:0% +interactions okay uh as we talked about + + + align:start position:0% +interactions okay uh as we talked about +last time this the formulation for this + + align:start position:0% +last time this the formulation for this + + + align:start position:0% +last time this the formulation for this +is a little bit different you got to + + align:start position:0% +is a little bit different you got to + + + align:start position:0% +is a little bit different you got to +tweak it a bit um but uh it's follows + + align:start position:0% +tweak it a bit um but uh it's follows + + + align:start position:0% +tweak it a bit um but uh it's follows +the ideas we're going to talk about so + + align:start position:0% +the ideas we're going to talk about so + + + align:start position:0% +the ideas we're going to talk about so +what we are talking about here is any + + align:start position:0% +what we are talking about here is any + + + align:start position:0% +what we are talking about here is any +experiment in which you've got three + + align:start position:0% +experiment in which you've got three + + + align:start position:0% +experiment in which you've got three +independent variables okay up here I + + align:start position:0% +independent variables okay up here I + + + align:start position:0% +independent variables okay up here I +just want to point out remember in our + + align:start position:0% +just want to point out remember in our + + + align:start position:0% +just want to point out remember in our +third order response function this + + align:start position:0% +third order response function this + + + align:start position:0% +third order response function this +involves three independent uh time + + align:start position:0% +involves three independent uh time + + + align:start position:0% +involves three independent uh time +variables the time delays between it + + align:start position:0% +variables the time delays between it + + + align:start position:0% +variables the time delays between it +different fields those are the ones we + + align:start position:0% +different fields those are the ones we + + + align:start position:0% +different fields those are the ones we +like or um three independent input + + align:start position:0% +like or um three independent input + + + align:start position:0% +like or um three independent input +frequencies or some combination thereof + + align:start position:0% +frequencies or some combination thereof + + + align:start position:0% +frequencies or some combination thereof +okay and in the case of pump probe + + align:start position:0% +okay and in the case of pump probe + + + align:start position:0% +okay and in the case of pump probe +experiments the way we think of this is + + align:start position:0% +experiments the way we think of this is + + + align:start position:0% +experiments the way we think of this is +that this is uh the three variables that + + align:start position:0% +that this is uh the three variables that + + + align:start position:0% +that this is uh the three variables that +we have control over are you know the + + align:start position:0% +we have control over are you know the + + + align:start position:0% +we have control over are you know the +frequency of the pump the frequency of + + align:start position:0% +frequency of the pump the frequency of + + + align:start position:0% +frequency of the pump the frequency of +the probe and probably the time delay + + align:start position:0% +the probe and probably the time delay + + + align:start position:0% +the probe and probably the time delay +between the two + + align:start position:0% +between the two + + + align:start position:0% +between the two +okay so that's that's the first clue + + align:start position:0% +okay so that's that's the first clue + + + align:start position:0% +okay so that's that's the first clue +that you've got a third order + + align:start position:0% +that you've got a third order + + + align:start position:0% +that you've got a third order +experiment okay + + align:start position:0% +experiment okay + + + align:start position:0% +experiment okay +and and + + align:start position:0% +and and + + + align:start position:0% +and and +so + + align:start position:0% + + + + align:start position:0% + +yeah okay so the the first thing to + + align:start position:0% +yeah okay so the the first thing to + + + align:start position:0% +yeah okay so the the first thing to +recognize is that uh this two beam + + align:start position:0% +recognize is that uh this two beam + + + align:start position:0% +recognize is that uh this two beam +experiment and the change and intensity + + align:start position:0% +experiment and the change and intensity + + + align:start position:0% +experiment and the change and intensity +on that signal detector really can just + + align:start position:0% +on that signal detector really can just + + + align:start position:0% +on that signal detector really can just +be thought of as a coherent third order + + align:start position:0% +be thought of as a coherent third order + + + align:start position:0% +be thought of as a coherent third order +experiment if we go back to + + align:start position:0% +experiment if we go back to + + + align:start position:0% +experiment if we go back to +um you know a standard box geometry here + + align:start position:0% +um you know a standard box geometry here + + + align:start position:0% +um you know a standard box geometry here +and we you know remember we thought of + + align:start position:0% +and we you know remember we thought of + + + align:start position:0% +and we you know remember we thought of +the transient grading as being this pump + + align:start position:0% +the transient grading as being this pump + + + align:start position:0% +the transient grading as being this pump +pair spatially separated and crossed in + + align:start position:0% +pair spatially separated and crossed in + + + align:start position:0% +pair spatially separated and crossed in +the sample and then a probe if you take + + align:start position:0% +the sample and then a probe if you take + + + align:start position:0% +the sample and then a probe if you take +the limit that pulse one and two overlap + + align:start position:0% +the limit that pulse one and two overlap + + + align:start position:0% +the limit that pulse one and two overlap +and that they in fact come from the same + + align:start position:0% +and that they in fact come from the same + + + align:start position:0% +and that they in fact come from the same +field that's just a pump probe + + align:start position:0% +field that's just a pump probe + + + align:start position:0% +field that's just a pump probe +experiment that also means that as + + align:start position:0% +experiment that also means that as + + + align:start position:0% +experiment that also means that as +you're gradually approaching colinearity + + align:start position:0% +you're gradually approaching colinearity + + + align:start position:0% +you're gradually approaching colinearity +here it means that the signal is + + align:start position:0% +here it means that the signal is + + + align:start position:0% +here it means that the signal is +gradually uh becoming colinear with the + + align:start position:0% +gradually uh becoming colinear with the + + + align:start position:0% +gradually uh becoming colinear with the +transmitted probe and so what she really + + align:start position:0% +transmitted probe and so what she really + + + align:start position:0% +transmitted probe and so what she really +observing when you look at the intensity + + align:start position:0% +observing when you look at the intensity + + + align:start position:0% +observing when you look at the intensity +of the transmitted probe is a sum of two + + align:start position:0% +of the transmitted probe is a sum of two + + + align:start position:0% +of the transmitted probe is a sum of two +Fields the transmitted field and the + + align:start position:0% +Fields the transmitted field and the + + + align:start position:0% +Fields the transmitted field and the +generated signal okay and so that um + + align:start position:0% +generated signal okay and so that um + + + align:start position:0% +generated signal okay and so that um +that's sort of the coherent description + + align:start position:0% +that's sort of the coherent description + + + align:start position:0% +that's sort of the coherent description +of a pump probe experiment and so then + + align:start position:0% +of a pump probe experiment and so then + + + align:start position:0% +of a pump probe experiment and so then +you know you can start talking about + + align:start position:0% +you know you can start talking about + + + align:start position:0% +you know you can start talking about +okay what is the change of intensity + + align:start position:0% +okay what is the change of intensity + + + align:start position:0% +okay what is the change of intensity +that I see when I add the pump + + align:start position:0% +that I see when I add the pump + + + align:start position:0% +that I see when I add the pump +beam + + align:start position:0% +beam + + + align:start position:0% +beam +um as a function of this delay and it uh + + align:start position:0% +um as a function of this delay and it uh + + + align:start position:0% +um as a function of this delay and it uh +is basically going to involve you know + + align:start position:0% +is basically going to involve you know + + + align:start position:0% +is basically going to involve you know +what is the + + align:start position:0% +what is the + + + align:start position:0% +what is the +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +um with the pump there why it's the + + align:start position:0% +um with the pump there why it's the + + + align:start position:0% +um with the pump there why it's the +intensity without the pump there okay do + + align:start position:0% +intensity without the pump there okay do + + + align:start position:0% +intensity without the pump there okay do +you had a + + align:start position:0% +you had a + + + align:start position:0% +you had a +question I just want to clarify some + + align:start position:0% +question I just want to clarify some + + + align:start position:0% +question I just want to clarify some +language in mind what you just described + + align:start position:0% +language in mind what you just described + + + align:start position:0% +language in mind what you just described +is this the same as saying that pump + + align:start position:0% +is this the same as saying that pump + + + align:start position:0% +is this the same as saying that pump +probe is always heter just yes exactly + + align:start position:0% +probe is always heter just yes exactly + + + align:start position:0% +probe is always heter just yes exactly +it's intrinsically heterodon that's the + + align:start position:0% +it's intrinsically heterodon that's the + + + align:start position:0% +it's intrinsically heterodon that's the +word we use for yeah so that that's sort + + align:start position:0% +word we use for yeah so that that's sort + + + align:start position:0% +word we use for yeah so that that's sort +of what I want to show here is that that + + align:start position:0% +of what I want to show here is that that + + + align:start position:0% +of what I want to show here is that that +um that it is uh you're not actually + + align:start position:0% +um that it is uh you're not actually + + + align:start position:0% +um that it is uh you're not actually +measuring a technique you're you're not + + align:start position:0% +measuring a technique you're you're not + + + align:start position:0% +measuring a technique you're you're not +measuring an intensity actually but + + align:start position:0% +measuring an intensity actually but + + + align:start position:0% +measuring an intensity actually but +you're really measuring something + + align:start position:0% +you're really measuring something + + + align:start position:0% +you're really measuring something +directly proportional to the + + align:start position:0% +directly proportional to the + + + align:start position:0% +directly proportional to the +polarization in the response okay so if + + align:start position:0% +polarization in the response okay so if + + + align:start position:0% +polarization in the response okay so if +you think about this a little bit the + + align:start position:0% +you think about this a little bit the + + + align:start position:0% +you think about this a little bit the +intensity with the pump there is going + + align:start position:0% +intensity with the pump there is going + + + align:start position:0% +intensity with the pump there is going +to look something like the um intensity + + align:start position:0% +to look something like the um intensity + + + align:start position:0% +to look something like the um intensity +of the transmitted pump light and + + align:start position:0% + + + + align:start position:0% + +I'm sorry the the the field of the pump + + align:start position:0% +I'm sorry the the the field of the pump + + + align:start position:0% +I'm sorry the the the field of the pump +plus the signal and of course the + + align:start position:0% +plus the signal and of course the + + + align:start position:0% +plus the signal and of course the +intensity is going to go as a modulus + + align:start position:0% +intensity is going to go as a modulus + + + align:start position:0% +intensity is going to go as a modulus +squared and then you're going to + + align:start position:0% +squared and then you're going to + + + align:start position:0% +squared and then you're going to +subtract away just + + align:start position:0% +subtract away just + + + align:start position:0% +subtract away just +the um intensity of the probe beam + + align:start position:0% +the um intensity of the probe beam + + + align:start position:0% +the um intensity of the probe beam +itself without the pump so this + + align:start position:0% +itself without the pump so this + + + align:start position:0% +itself without the pump so this +is oh I'm sorry I'm getting this wrong + + align:start position:0% +is oh I'm sorry I'm getting this wrong + + + align:start position:0% +is oh I'm sorry I'm getting this wrong +intensity of the probe beam + + align:start position:0% +intensity of the probe beam + + + align:start position:0% +intensity of the probe beam +transmitted subtract that okay so + + align:start position:0% +transmitted subtract that okay so + + + align:start position:0% +transmitted subtract that okay so +technically this is what your measure + + align:start position:0% +technically this is what your measure + + + align:start position:0% +technically this is what your measure +meur in okay and so you're typically + + align:start position:0% +meur in okay and so you're typically + + + align:start position:0% +meur in okay and so you're typically +working in a regime where this change of + + align:start position:0% +working in a regime where this change of + + + align:start position:0% +working in a regime where this change of +intensity is small compared to the uh + + align:start position:0% +intensity is small compared to the uh + + + align:start position:0% +intensity is small compared to the uh +intensity of the pump probe itself and + + align:start position:0% +intensity of the pump probe itself and + + + align:start position:0% +intensity of the pump probe itself and +so what you're saying by that is that + + align:start position:0% +so what you're saying by that is that + + + align:start position:0% +so what you're saying by that is that +the + + align:start position:0% +the + + + align:start position:0% +the +magnitude of the probe uh the field is + + align:start position:0% +magnitude of the probe uh the field is + + + align:start position:0% +magnitude of the probe uh the field is +going to be much + + align:start position:0% +going to be much + + + align:start position:0% +going to be much +greater and that of the + + align:start position:0% +greater and that of the + + + align:start position:0% +greater and that of the +signal okay oops and confusing things + + align:start position:0% +signal okay oops and confusing things + + + align:start position:0% +signal okay oops and confusing things +here and So based on that we can expand + + align:start position:0% +here and So based on that we can expand + + + align:start position:0% +here and So based on that we can expand +this out you can see what happens is + + align:start position:0% +this out you can see what happens is + + + align:start position:0% +this out you can see what happens is +sort of the biggest term the leading + + align:start position:0% +sort of the biggest term the leading + + + align:start position:0% +sort of the biggest term the leading +term which is uh the intensity of the + + align:start position:0% +term which is uh the intensity of the + + + align:start position:0% +term which is uh the intensity of the +probe here and here those subtract away + + align:start position:0% +probe here and here those subtract away + + + align:start position:0% +probe here and here those subtract away +um the square signal term we're going to + + align:start position:0% +um the square signal term we're going to + + + align:start position:0% +um the square signal term we're going to +ignore that just because it's small + + align:start position:0% +ignore that just because it's small + + + align:start position:0% +ignore that just because it's small +compared to the Cross term and the cross + + align:start position:0% +compared to the Cross term and the cross + + + align:start position:0% +compared to the Cross term and the cross +term um you know looks like + + align:start position:0% + + + + align:start position:0% + +okay and so this is just the real part I + + align:start position:0% +okay and so this is just the real part I + + + align:start position:0% +okay and so this is just the real part I +by the way I've left out all the + + align:start position:0% +by the way I've left out all the + + + align:start position:0% +by the way I've left out all the +proportionality factors here this is + + align:start position:0% +proportionality factors here this is + + + align:start position:0% +proportionality factors here this is +just the real part of + + align:start position:0% +just the real part of + + + align:start position:0% +just the real part of +the + + align:start position:0% +the + + + align:start position:0% +the +um probe times the + + align:start position:0% +um probe times the + + + align:start position:0% +um probe times the +signal okay and now if you look at which + + align:start position:0% +signal okay and now if you look at which + + + align:start position:0% +signal okay and now if you look at which +of those quantities are dependent on + + align:start position:0% +of those quantities are dependent on + + + align:start position:0% +of those quantities are dependent on +this time delay over here here well this + + align:start position:0% +this time delay over here here well this + + + align:start position:0% +this time delay over here here well this +this is just a constant and so you + + align:start position:0% +this is just a constant and so you + + + align:start position:0% +this is just a constant and so you +really have something linearly + + align:start position:0% +really have something linearly + + + align:start position:0% +really have something linearly +proportional this is the function of the + + align:start position:0% +proportional this is the function of the + + + align:start position:0% +proportional this is the function of the +time delay you really have a that the + + align:start position:0% +time delay you really have a that the + + + align:start position:0% +time delay you really have a that the +change in intensity is linearly + + align:start position:0% +change in intensity is linearly + + + align:start position:0% +change in intensity is linearly +proportional to the nonlinear signal + + align:start position:0% +proportional to the nonlinear signal + + + align:start position:0% +proportional to the nonlinear signal +okay and uh just remembering + + align:start position:0% +okay and uh just remembering + + + align:start position:0% +okay and uh just remembering +that the uh signal had a pi over 2 phase + + align:start position:0% +that the uh signal had a pi over 2 phase + + + align:start position:0% +that the uh signal had a pi over 2 phase +shift relative to the nonlinear + + align:start position:0% +shift relative to the nonlinear + + + align:start position:0% +shift relative to the nonlinear +polarization + + align:start position:0% +polarization + + + align:start position:0% +polarization +and also remembering that for our + + align:start position:0% +and also remembering that for our + + + align:start position:0% +and also remembering that for our +purposes that the nonlinear polarization + + align:start position:0% +purposes that the nonlinear polarization + + + align:start position:0% +purposes that the nonlinear polarization +is proportional to the response function + + align:start position:0% +is proportional to the response function + + + align:start position:0% +is proportional to the response function +what we are really measuring is um the + + align:start position:0% +what we are really measuring is um the + + + align:start position:0% +what we are really measuring is um the +imaginary part of the product of the + + align:start position:0% +imaginary part of the product of the + + + align:start position:0% +imaginary part of the product of the +probe and Signal um probe field and uh + + align:start position:0% +probe and Signal um probe field and uh + + + align:start position:0% +probe and Signal um probe field and uh +signal polarization or or nonlinear + + align:start position:0% +signal polarization or or nonlinear + + + align:start position:0% +signal polarization or or nonlinear +response + + align:start position:0% + + + + align:start position:0% + +okay which um which is sort of what we + + align:start position:0% +okay which um which is sort of what we + + + align:start position:0% +okay which um which is sort of what we +expected right uh you would think of + + align:start position:0% +expected right uh you would think of + + + align:start position:0% +expected right uh you would think of +this experiment as transient absorption + + align:start position:0% +this experiment as transient absorption + + + align:start position:0% +this experiment as transient absorption +how does the you know how is the + + align:start position:0% +how does the you know how is the + + + align:start position:0% +how does the you know how is the +absorption of the sample modulated by + + align:start position:0% +absorption of the sample modulated by + + + align:start position:0% +absorption of the sample modulated by +the pump beam right and that's just what + + align:start position:0% +the pump beam right and that's just what + + + align:start position:0% +the pump beam right and that's just what +we're looking at here the imaginary part + + align:start position:0% +we're looking at here the imaginary part + + + align:start position:0% +we're looking at here the imaginary part +of the polarization the absorptive + + align:start position:0% +of the polarization the absorptive + + + align:start position:0% +of the polarization the absorptive +part okay so it's just like you said + + align:start position:0% +part okay so it's just like you said + + + align:start position:0% +part okay so it's just like you said +that you can think of this as the + + align:start position:0% +that you can think of this as the + + + align:start position:0% +that you can think of this as the +transmitted field being aerodine a phase + + align:start position:0% +transmitted field being aerodine a phase + + + align:start position:0% +transmitted field being aerodine a phase +locked heterodon field that's that + + align:start position:0% +locked heterodon field that's that + + + align:start position:0% +locked heterodon field that's that +you're beating against the system and + + align:start position:0% +you're beating against the system and + + + align:start position:0% +you're beating against the system and +uh you know for an incoherent experiment + + align:start position:0% +uh you know for an incoherent experiment + + + align:start position:0% +uh you know for an incoherent experiment +you're going through an awful lot of + + align:start position:0% +you're going through an awful lot of + + + align:start position:0% +you're going through an awful lot of +math to describe that but it makes a lot + + align:start position:0% +math to describe that but it makes a lot + + + align:start position:0% +math to describe that but it makes a lot +of sense when you start to look at wave + + align:start position:0% +of sense when you start to look at wave + + + align:start position:0% +of sense when you start to look at wave +packet Dynamics on on pump probe + + align:start position:0% +packet Dynamics on on pump probe + + + align:start position:0% +packet Dynamics on on pump probe +experiments okay any any questions on + + align:start position:0% +experiments okay any any questions on + + + align:start position:0% +experiments okay any any questions on +that okay um + + align:start position:0% +that okay um + + + align:start position:0% +that okay um +so so just uh let's + + align:start position:0% +so so just uh let's + + + align:start position:0% +so so just uh let's +see um so as you might imagine let me + + align:start position:0% +see um so as you might imagine let me + + + align:start position:0% +see um so as you might imagine let me +just go just for purposes of making this + + align:start position:0% +just go just for purposes of making this + + + align:start position:0% +just go just for purposes of making this +easy let's see + + align:start position:0% +easy let's see + + + align:start position:0% +easy let's see +um as you might imagine any sort of + + align:start position:0% +um as you might imagine any sort of + + + align:start position:0% +um as you might imagine any sort of +relaxation process that contributes to + + align:start position:0% +relaxation process that contributes to + + + align:start position:0% +relaxation process that contributes to +the absorptive the imaginary part of the + + align:start position:0% +the absorptive the imaginary part of the + + + align:start position:0% +the absorptive the imaginary part of the +polarization the absorption change in + + align:start position:0% +polarization the absorption change in + + + align:start position:0% +polarization the absorption change in +the sample as a function at time delay + + align:start position:0% +the sample as a function at time delay + + + align:start position:0% +the sample as a function at time delay +you're going to see it and um now one + + align:start position:0% +you're going to see it and um now one + + + align:start position:0% +you're going to see it and um now one +other thing to point out is you know + + align:start position:0% +other thing to point out is you know + + + align:start position:0% +other thing to point out is you know +when you write out all of the possible + + align:start position:0% +when you write out all of the possible + + + align:start position:0% +when you write out all of the possible +dipole interaction processes that can + + align:start position:0% +dipole interaction processes that can + + + align:start position:0% +dipole interaction processes that can +contribute in that signal Direction it's + + align:start position:0% +contribute in that signal Direction it's + + + align:start position:0% +contribute in that signal Direction it's +all four of the possible correlation + + align:start position:0% +all four of the possible correlation + + + align:start position:0% +all four of the possible correlation +functions in that nonlinear + + align:start position:0% +functions in that nonlinear + + + align:start position:0% +functions in that nonlinear +response and so what uh you + + align:start position:0% +response and so what uh you + + + align:start position:0% +response and so what uh you +will um see is a number of different + + align:start position:0% +will um see is a number of different + + + align:start position:0% +will um see is a number of different +contributions probably the one that + + align:start position:0% +contributions probably the one that + + + align:start position:0% +contributions probably the one that +contributes to you know everyone that + + align:start position:0% +contributes to you know everyone that + + + align:start position:0% +contributes to you know everyone that +does this experiment is that Delta I + + align:start position:0% +does this experiment is that Delta I + + + align:start position:0% +does this experiment is that Delta I +will look at the um population + + align:start position:0% + + + + align:start position:0% + +relaxation um in in the uh ground and + + align:start position:0% +relaxation um in in the uh ground and + + + align:start position:0% +relaxation um in in the uh ground and +the excited States that you are coupling + + align:start position:0% +the excited States that you are coupling + + + align:start position:0% +the excited States that you are coupling +together so if you imagine you do these + + align:start position:0% +together so if you imagine you do these + + + align:start position:0% +together so if you imagine you do these +all with this um with the same color + + align:start position:0% +all with this um with the same color + + + align:start position:0% +all with this um with the same color +experiment now what you're doing is um + + align:start position:0% +experiment now what you're doing is um + + + align:start position:0% +experiment now what you're doing is um +call this one a and this one B you will + + align:start position:0% +call this one a and this one B you will + + + align:start position:0% +call this one a and this one B you will +find that there are processes that tell + + align:start position:0% +find that there are processes that tell + + + align:start position:0% +find that there are processes that tell +you about how fast does population relax + + align:start position:0% +you about how fast does population relax + + + align:start position:0% +you about how fast does population relax +out of the excited state and furthermore + + align:start position:0% +out of the excited state and furthermore + + + align:start position:0% +out of the excited state and furthermore +how does population return to the ground + + align:start position:0% +how does population return to the ground + + + align:start position:0% +how does population return to the ground +state you can think of that as the pump + + align:start position:0% +state you can think of that as the pump + + + align:start position:0% +state you can think of that as the pump +field not only creates an excited state + + align:start position:0% +field not only creates an excited state + + + align:start position:0% +field not only creates an excited state +population + + align:start position:0% +population + + + align:start position:0% +population +but it also creates a bleach a hole in + + align:start position:0% +but it also creates a bleach a hole in + + + align:start position:0% +but it also creates a bleach a hole in +the ground state and you watch both of + + align:start position:0% +the ground state and you watch both of + + + align:start position:0% +the ground state and you watch both of +those things in the limit that you + + align:start position:0% +those things in the limit that you + + + align:start position:0% +those things in the limit that you +return from the excited state to the + + align:start position:0% +return from the excited state to the + + + align:start position:0% +return from the excited state to the +ground state this becomes a simple simp + + align:start position:0% +ground state this becomes a simple simp + + + align:start position:0% +ground state this becomes a simple simp +exponential but um could be more + + align:start position:0% +exponential but um could be more + + + align:start position:0% +exponential but um could be more +complicated than that + + align:start position:0% +complicated than that + + + align:start position:0% +complicated than that +okay it's coupling through the fat + + align:start position:0% +okay it's coupling through the fat + + + align:start position:0% +okay it's coupling through the fat +States well you can imagine yeah right + + align:start position:0% +States well you can imagine yeah right + + + align:start position:0% +States well you can imagine yeah right +if you mean by dark States here right so + + align:start position:0% +if you mean by dark States here right so + + + align:start position:0% +if you mean by dark States here right so +you can imagine say you have an + + align:start position:0% +you can imagine say you have an + + + align:start position:0% +you can imagine say you have an +intermediate state that you're relax + + align:start position:0% +intermediate state that you're relax + + + align:start position:0% +intermediate state that you're relax +through on your way down you know then + + align:start position:0% +through on your way down you know then + + + align:start position:0% +through on your way down you know then +the rate of leaving this state and the + + align:start position:0% +the rate of leaving this state and the + + + align:start position:0% +the rate of leaving this state and the +rate of arriving here is going to be + + align:start position:0% +rate of arriving here is going to be + + + align:start position:0% +rate of arriving here is going to be +different so seeing by exponential + + align:start position:0% +different so seeing by exponential + + + align:start position:0% +different so seeing by exponential +Behavior shouldn't be a surprise + + align:start position:0% +Behavior shouldn't be a surprise + + + align:start position:0% +Behavior shouldn't be a surprise +right okay so uh now this way of + + align:start position:0% +right okay so uh now this way of + + + align:start position:0% +right okay so uh now this way of +thinking about it really applies to + + align:start position:0% +thinking about it really applies to + + + align:start position:0% +thinking about it really applies to +experiments that look at wave packet + + align:start position:0% +experiments that look at wave packet + + + align:start position:0% +experiments that look at wave packet +propagation whether you're talking about + + align:start position:0% +propagation whether you're talking about + + + align:start position:0% +propagation whether you're talking about +you know electronic or vibrational + + align:start position:0% +you know electronic or vibrational + + + align:start position:0% +you know electronic or vibrational +spectroscopies um basic idea is you know + + align:start position:0% +spectroscopies um basic idea is you know + + + align:start position:0% +spectroscopies um basic idea is you know +it's pretty common that you see + + align:start position:0% +it's pretty common that you see + + + align:start position:0% +it's pretty common that you see +experiments that describe starting in + + align:start position:0% +experiments that describe starting in + + + align:start position:0% +experiments that describe starting in +some you know electronic + + align:start position:0% +some you know electronic + + + align:start position:0% +some you know electronic +State uh + + align:start position:0% +State uh + + + align:start position:0% +State uh +propagating the system then on an + + align:start position:0% +propagating the system then on an + + + align:start position:0% +propagating the system then on an +excited electronic surface and you know + + align:start position:0% +excited electronic surface and you know + + + align:start position:0% +excited electronic surface and you know +people probe this all over if if you you + + align:start position:0% +people probe this all over if if you you + + + align:start position:0% +people probe this all over if if you you +know really are interested in it + + align:start position:0% +know really are interested in it + + + align:start position:0% +know really are interested in it +studying the system as a function of you + + align:start position:0% +studying the system as a function of you + + + align:start position:0% +studying the system as a function of you +know sort of the nuclear coordinates of + + align:start position:0% +know sort of the nuclear coordinates of + + + align:start position:0% +know sort of the nuclear coordinates of +the uh system say in a reactive one you + + align:start position:0% +the uh system say in a reactive one you + + + align:start position:0% +the uh system say in a reactive one you +know you might imagine choosing the + + align:start position:0% +know you might imagine choosing the + + + align:start position:0% +know you might imagine choosing the +probe + + align:start position:0% +probe + + + align:start position:0% +probe +uh the pump and the probe frequency + + align:start position:0% +uh the pump and the probe frequency + + + align:start position:0% +uh the pump and the probe frequency +don't have to be the same at all + + align:start position:0% +don't have to be the same at all + + + align:start position:0% +don't have to be the same at all +right um they are chosen to match + + align:start position:0% +right um they are chosen to match + + + align:start position:0% +right um they are chosen to match +certain energy gaps in the uh um you + + align:start position:0% +certain energy gaps in the uh um you + + + align:start position:0% +certain energy gaps in the uh um you +know along this potential and You by + + align:start position:0% +know along this potential and You by + + + align:start position:0% +know along this potential and You by +tuning your prob beam you can imagine uh + + align:start position:0% +tuning your prob beam you can imagine uh + + + align:start position:0% +tuning your prob beam you can imagine uh +pulling out um the you know wave packet + + align:start position:0% +pulling out um the you know wave packet + + + align:start position:0% +pulling out um the you know wave packet +Dynamics um as a function of this + + align:start position:0% +Dynamics um as a function of this + + + align:start position:0% +Dynamics um as a function of this +coordinate Q okay so the pump and the + + align:start position:0% +coordinate Q okay so the pump and the + + + align:start position:0% +coordinate Q okay so the pump and the +probe are just independent variables and + + align:start position:0% +probe are just independent variables and + + + align:start position:0% +probe are just independent variables and +you'll notice going back to the wave + + align:start position:0% +you'll notice going back to the wave + + + align:start position:0% +you'll notice going back to the wave +Vector matching that that's the beauty + + align:start position:0% +Vector matching that that's the beauty + + + align:start position:0% +Vector matching that that's the beauty +of a pump probe in our language is that + + align:start position:0% +of a pump probe in our language is that + + + align:start position:0% +of a pump probe in our language is that +it's always wave Vector matched just by + + align:start position:0% +it's always wave Vector matched just by + + + align:start position:0% +it's always wave Vector matched just by +by definition how how it's set up okay + + align:start position:0% +by definition how how it's set up okay + + + align:start position:0% +by definition how how it's set up okay +so um in the diagrammatic perturbation + + align:start position:0% +so um in the diagrammatic perturbation + + + align:start position:0% +so um in the diagrammatic perturbation +Theory language what we're talking about + + align:start position:0% +Theory language what we're talking about + + + align:start position:0% +Theory language what we're talking about +is uh these sorts of diagrams so let me + + align:start position:0% +is uh these sorts of diagrams so let me + + + align:start position:0% +is uh these sorts of diagrams so let me +go back for a + + align:start position:0% +go back for a + + + align:start position:0% +go back for a +moment I I showed you that these are + + align:start position:0% +moment I I showed you that these are + + + align:start position:0% +moment I I showed you that these are +sort of the fundamental + + align:start position:0% +sort of the fundamental + + + align:start position:0% +sort of the fundamental +um four fundamental interaction + + align:start position:0% +um four fundamental interaction + + + align:start position:0% +um four fundamental interaction +processes for light coupling um to a + + align:start position:0% +processes for light coupling um to a + + + align:start position:0% +processes for light coupling um to a +twole uh system um but in you know in + + align:start position:0% +twole uh system um but in you know in + + + align:start position:0% +twole uh system um but in you know in +general you can have up to four levels + + align:start position:0% +general you can have up to four levels + + + align:start position:0% +general you can have up to four levels +that are coupled in a third + + align:start position:0% +that are coupled in a third + + + align:start position:0% +that are coupled in a third +order um experiment and this is just + + align:start position:0% +order um experiment and this is just + + + align:start position:0% +order um experiment and this is just +sort of generalizing those diagrams to + + align:start position:0% +sort of generalizing those diagrams to + + + align:start position:0% +sort of generalizing those diagrams to +four levels that I've arranged in a + + align:start position:0% +four levels that I've arranged in a + + + align:start position:0% +four levels that I've arranged in a +particular way just because they + + align:start position:0% +particular way just because they + + + align:start position:0% +particular way just because they +correspond to this wave packet type of + + align:start position:0% +correspond to this wave packet type of + + + align:start position:0% +correspond to this wave packet type of +process we have some + + align:start position:0% +process we have some + + + align:start position:0% +process we have some +uh processes that create wave packets in + + align:start position:0% +uh processes that create wave packets in + + + align:start position:0% +uh processes that create wave packets in +the you can see here is a difference + + align:start position:0% +the you can see here is a difference + + + align:start position:0% +the you can see here is a difference +frequency creates a coherence a wave + + align:start position:0% +frequency creates a coherence a wave + + + align:start position:0% +frequency creates a coherence a wave +packet in the ground electronic state + + align:start position:0% +packet in the ground electronic state + + + align:start position:0% +packet in the ground electronic state +where you whereas you've got others that + + align:start position:0% +where you whereas you've got others that + + + align:start position:0% +where you whereas you've got others that +create Co a wave packet on the excited + + align:start position:0% +create Co a wave packet on the excited + + + align:start position:0% +create Co a wave packet on the excited +state both of these then propagate + + align:start position:0% +state both of these then propagate + + + align:start position:0% +state both of these then propagate +freely during the second T2 the second + + align:start position:0% +freely during the second T2 the second + + + align:start position:0% +freely during the second T2 the second +time variable one on the excited state + + align:start position:0% +time variable one on the excited state + + + align:start position:0% +time variable one on the excited state +one on the ground state and then you + + align:start position:0% +one on the ground state and then you + + + align:start position:0% +one on the ground state and then you +probe it and of course you know you can + + align:start position:0% +probe it and of course you know you can + + + align:start position:0% +probe it and of course you know you can +choose where you probe it and how you + + align:start position:0% +choose where you probe it and how you + + + align:start position:0% +choose where you probe it and how you +probe it okay so th um + + align:start position:0% +probe it okay so th um + + + align:start position:0% +probe it okay so th um +so those + + align:start position:0% +so those + + + align:start position:0% +so those +are uh the processes that you know I was + + align:start position:0% +are uh the processes that you know I was + + + align:start position:0% +are uh the processes that you know I was +uh picturing here that + + align:start position:0% +uh picturing here that + + + align:start position:0% +uh picturing here that +um those uh sorts of diagrams are sort + + align:start position:0% +um those uh sorts of diagrams are sort + + + align:start position:0% +um those uh sorts of diagrams are sort +of the mathematical way of describing + + align:start position:0% +of the mathematical way of describing + + + align:start position:0% +of the mathematical way of describing +why one would see Quantum beats for + + align:start position:0% +why one would see Quantum beats for + + + align:start position:0% +why one would see Quantum beats for +instance in a + + align:start position:0% +instance in a + + + align:start position:0% +instance in a +um either a transient absorption or even + + align:start position:0% +um either a transient absorption or even + + + align:start position:0% +um either a transient absorption or even +an incoherent uh fluoresence experiment + + align:start position:0% +an incoherent uh fluoresence experiment + + + align:start position:0% +an incoherent uh fluoresence experiment +with two you know with two + + align:start position:0% + + + + align:start position:0% + +Fields by + + align:start position:0% +Fields by + + + align:start position:0% +Fields by +by the way one one important thing I + + align:start position:0% +by the way one one important thing I + + + align:start position:0% +by the way one one important thing I +don't want you to carry away from this + + align:start position:0% +don't want you to carry away from this + + + align:start position:0% +don't want you to carry away from this +is that there there is no simple + + align:start position:0% +is that there there is no simple + + + align:start position:0% +is that there there is no simple +connection between these types + + align:start position:0% +connection between these types + + + align:start position:0% +connection between these types +of diagrams that are really commonly + + align:start position:0% +of diagrams that are really commonly + + + align:start position:0% +of diagrams that are really commonly +drawn and the fan diagrams these are not + + align:start position:0% +drawn and the fan diagrams these are not + + + align:start position:0% +drawn and the fan diagrams these are not +the same thing it is true that there + + align:start position:0% +the same thing it is true that there + + + align:start position:0% +the same thing it is true that there +happens to be know mapping onto the + + align:start position:0% +happens to be know mapping onto the + + + align:start position:0% +happens to be know mapping onto the +same uh energy axis if you're drawing + + align:start position:0% +same uh energy axis if you're drawing + + + align:start position:0% +same uh energy axis if you're drawing +lad diagrams but uh find and lad + + align:start position:0% +lad diagrams but uh find and lad + + + align:start position:0% +lad diagrams but uh find and lad +diagrams propagate the density Matrix + + align:start position:0% +diagrams propagate the density Matrix + + + align:start position:0% +diagrams propagate the density Matrix +and this is energies is a function of + + align:start position:0% +and this is energies is a function of + + + align:start position:0% +and this is energies is a function of +nuclear coordinate + + align:start position:0% +nuclear coordinate + + + align:start position:0% +nuclear coordinate +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so that what I'm implying by that is + + align:start position:0% +so so that what I'm implying by that is + + + align:start position:0% +so so that what I'm implying by that is +that when you draw one of these types of + + align:start position:0% +that when you draw one of these types of + + + align:start position:0% +that when you draw one of these types of +processes and and say that you create a + + align:start position:0% +processes and and say that you create a + + + align:start position:0% +processes and and say that you create a +wave packet in a density Matrix language + + align:start position:0% +wave packet in a density Matrix language + + + align:start position:0% +wave packet in a density Matrix language +that is equivalent + + align:start position:0% +that is equivalent + + + align:start position:0% +that is equivalent +to creating a coherent superposition of + + align:start position:0% +to creating a coherent superposition of + + + align:start position:0% +to creating a coherent superposition of +two igen states of the electronic ided + + align:start position:0% +two igen states of the electronic ided + + + align:start position:0% +two igen states of the electronic ided +surface that then propagate + + align:start position:0% + + + + align:start position:0% + +okay all right any any questions on pump + + align:start position:0% +okay all right any any questions on pump + + + align:start position:0% +okay all right any any questions on pump +probes okay + + align:start position:0% + + + + align:start position:0% + +um sort of in our in our list of things + + align:start position:0% +um sort of in our in our list of things + + + align:start position:0% +um sort of in our in our list of things +let me what I'm hoping to do at some + + align:start position:0% +let me what I'm hoping to do at some + + + align:start position:0% +let me what I'm hoping to do at some +point is actually spend some real time + + align:start position:0% +point is actually spend some real time + + + align:start position:0% +point is actually spend some real time +on Ramen spectroscopies but just uh so + + align:start position:0% +on Ramen spectroscopies but just uh so + + + align:start position:0% +on Ramen spectroscopies but just uh so +that we see it I want to talk a bit + + align:start position:0% +that we see it I want to talk a bit + + + align:start position:0% +that we see it I want to talk a bit +about um car spectroscopy just as an + + align:start position:0% +about um car spectroscopy just as an + + + align:start position:0% +about um car spectroscopy just as an +example of coherent Ramen techniques + + align:start position:0% + + + + align:start position:0% + +um let me + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +see yeah I have to say I think there's + + align:start position:0% +see yeah I have to say I think there's + + + align:start position:0% +see yeah I have to say I think there's +nothing quite as stunning as going into + + align:start position:0% +nothing quite as stunning as going into + + + align:start position:0% +nothing quite as stunning as going into +a lab that does cars in the visible + + align:start position:0% +a lab that does cars in the visible + + + align:start position:0% +a lab that does cars in the visible +because this is one of these experiments + + align:start position:0% +because this is one of these experiments + + + align:start position:0% +because this is one of these experiments +now which is not a degenerate experiment + + align:start position:0% +now which is not a degenerate experiment + + + align:start position:0% +now which is not a degenerate experiment +where you have multiple colors and + + align:start position:0% +where you have multiple colors and + + + align:start position:0% +where you have multiple colors and +you're specifically trying to take + + align:start position:0% +you're specifically trying to take + + + align:start position:0% +you're specifically trying to take +advantage of difference frequencies in + + align:start position:0% +advantage of difference frequencies in + + + align:start position:0% +advantage of difference frequencies in +the optical range to drive vibrational + + align:start position:0% +the optical range to drive vibrational + + + align:start position:0% +the optical range to drive vibrational +Transitions and you know it it is pretty + + align:start position:0% +Transitions and you know it it is pretty + + + align:start position:0% +Transitions and you know it it is pretty +stunning with people that do three color + + align:start position:0% +stunning with people that do three color + + + align:start position:0% +stunning with people that do three color +cars where really have three tunable + + align:start position:0% +cars where really have three tunable + + + align:start position:0% +cars where really have three tunable +colors incident on the sample Crossing + + align:start position:0% +colors incident on the sample Crossing + + + align:start position:0% +colors incident on the sample Crossing +and you get an enormous array of spots + + align:start position:0% +and you get an enormous array of spots + + + align:start position:0% +and you get an enormous array of spots +in every color you can imagine that + + align:start position:0% +in every color you can imagine that + + + align:start position:0% +in every color you can imagine that +comes out the back of the sample and + + align:start position:0% +comes out the back of the sample and + + + align:start position:0% +comes out the back of the sample and +each one of these encodes some sort of a + + align:start position:0% +each one of these encodes some sort of a + + + align:start position:0% +each one of these encodes some sort of a +different uh coherent vibrational + + align:start position:0% +different uh coherent vibrational + + + align:start position:0% +different uh coherent vibrational +dynamics of the system and cars is + + align:start position:0% +dynamics of the system and cars is + + + align:start position:0% +dynamics of the system and cars is +probably the the one that uh has been + + align:start position:0% +probably the the one that uh has been + + + align:start position:0% +probably the the one that uh has been +around the longest and still is really + + align:start position:0% +around the longest and still is really + + + align:start position:0% +around the longest and still is really +important um so the idea here + + align:start position:0% +important um so the idea here + + + align:start position:0% +important um so the idea here +is you can think of this as a Ramen + + align:start position:0% +is you can think of this as a Ramen + + + align:start position:0% +is you can think of this as a Ramen +transition + + align:start position:0% +transition + + + align:start position:0% +transition +um and now this sort of emphasizes the + + align:start position:0% +um and now this sort of emphasizes the + + + align:start position:0% +um and now this sort of emphasizes the +fact that if you look at our nonlinear + + align:start position:0% +fact that if you look at our nonlinear + + + align:start position:0% +fact that if you look at our nonlinear +response functions um as long as say for + + align:start position:0% +response functions um as long as say for + + + align:start position:0% +response functions um as long as say for +instance your first two fields our time + + align:start position:0% +instance your first two fields our time + + + align:start position:0% +instance your first two fields our time +coincident um you don't actually have to + + align:start position:0% +coincident um you don't actually have to + + + align:start position:0% +coincident um you don't actually have to +be + + align:start position:0% +be + + + align:start position:0% +be +resonant with a state um during the time + + align:start position:0% +resonant with a state um during the time + + + align:start position:0% +resonant with a state um during the time +period between the first and second + + align:start position:0% +period between the first and second + + + align:start position:0% +period between the first and second +interaction that uh just by the 4A + + align:start position:0% +interaction that uh just by the 4A + + + align:start position:0% +interaction that uh just by the 4A +transform principle if you remember + + align:start position:0% +transform principle if you remember + + + align:start position:0% +transform principle if you remember +those uh lovely sync functions from 574 + + align:start position:0% +those uh lovely sync functions from 574 + + + align:start position:0% +those uh lovely sync functions from 574 +that uh when time is very short you can + + align:start position:0% +that uh when time is very short you can + + + align:start position:0% +that uh when time is very short you can +be resonant at any frequency you want + + align:start position:0% +be resonant at any frequency you want + + + align:start position:0% +be resonant at any frequency you want +and it's resonance is only a condition + + align:start position:0% +and it's resonance is only a condition + + + align:start position:0% +and it's resonance is only a condition +that happens after several cycles of the + + align:start position:0% +that happens after several cycles of the + + + align:start position:0% +that happens after several cycles of the +field and so this is the language for + + align:start position:0% +field and so this is the language for + + + align:start position:0% +field and so this is the language for +this is virtual States and so what it + + align:start position:0% +this is virtual States and so what it + + + align:start position:0% +this is virtual States and so what it +means is if we take two fields and we + + align:start position:0% +means is if we take two fields and we + + + align:start position:0% +means is if we take two fields and we +are time + + align:start position:0% +are time + + + align:start position:0% +are time +coincident we can um generate + + align:start position:0% +coincident we can um generate + + + align:start position:0% +coincident we can um generate +excitations at difference frequencies so + + align:start position:0% +excitations at difference frequencies so + + + align:start position:0% +excitations at difference frequencies so +we choose two Fields um and in the cars + + align:start position:0% +we choose two Fields um and in the cars + + + align:start position:0% +we choose two Fields um and in the cars +language this would be the pump + + align:start position:0% +language this would be the pump + + + align:start position:0% +language this would be the pump +beam and the Stokes + + align:start position:0% + + + + align:start position:0% + +beam and what you do is then we'll call + + align:start position:0% +beam and what you do is then we'll call + + + align:start position:0% +beam and what you do is then we'll call +these say the or what did I call them up + + align:start position:0% +these say the or what did I call them up + + + align:start position:0% +these say the or what did I call them up +here g& e the ground and excited + + align:start position:0% +here g& e the ground and excited + + + align:start position:0% +here g& e the ground and excited +vibrational + + align:start position:0% + + + + align:start position:0% + +State um and it goes through sort of a + + align:start position:0% +State um and it goes through sort of a + + + align:start position:0% +State um and it goes through sort of a +virtual State and so um this is involves + + align:start position:0% +virtual State and so um this is involves + + + align:start position:0% +virtual State and so um this is involves +two transition dipole interactions the F + + align:start position:0% +two transition dipole interactions the F + + + align:start position:0% +two transition dipole interactions the F +so let's see what do we do + + align:start position:0% +so let's see what do we do + + + align:start position:0% +so let's see what do we do +e mu VG mu EG e + + align:start position:0% +e mu VG mu EG e + + + align:start position:0% +e mu VG mu EG e +v I'm okay they occur simultaneously and + + align:start position:0% +v I'm okay they occur simultaneously and + + + align:start position:0% +v I'm okay they occur simultaneously and +now the system is in a coherence and it + + align:start position:0% + + + + align:start position:0% + +propagates + + align:start position:0% +propagates + + + align:start position:0% +propagates +um oscillating with uh time this is to + + align:start position:0% +um oscillating with uh time this is to + + + align:start position:0% +um oscillating with uh time this is to +two um and we can say put some damping + + align:start position:0% +two um and we can say put some damping + + + align:start position:0% +two um and we can say put some damping +on + + align:start position:0% +on + + + align:start position:0% +on +this this vibrational wave package this + + align:start position:0% +this this vibrational wave package this + + + align:start position:0% +this this vibrational wave package this +vibrational coherence propagates with + + align:start position:0% +vibrational coherence propagates with + + + align:start position:0% +vibrational coherence propagates with +time and then we can probe it now in + + align:start position:0% +time and then we can probe it now in + + + align:start position:0% +time and then we can probe it now in +practice people use the same pump beam + + align:start position:0% +practice people use the same pump beam + + + align:start position:0% +practice people use the same pump beam +as also the probing field okay and this + + align:start position:0% +as also the probing field okay and this + + + align:start position:0% +as also the probing field okay and this +leads to an anti- Stoke signal + + align:start position:0% +leads to an anti- Stoke signal + + + align:start position:0% +leads to an anti- Stoke signal +emission um which is at a completely + + align:start position:0% +emission um which is at a completely + + + align:start position:0% +emission um which is at a completely +unique color so now just looking at this + + align:start position:0% +unique color so now just looking at this + + + align:start position:0% +unique color so now just looking at this +process this is Omega pump we can see + + align:start position:0% +process this is Omega pump we can see + + + align:start position:0% +process this is Omega pump we can see +that the signal is going to be plus + + align:start position:0% +that the signal is going to be plus + + + align:start position:0% +that the signal is going to be plus +Omega pump for the first one minus Omega + + align:start position:0% +Omega pump for the first one minus Omega + + + align:start position:0% +Omega pump for the first one minus Omega +Stokes for the second one plus Omega + + align:start position:0% +Stokes for the second one plus Omega + + + align:start position:0% +Stokes for the second one plus Omega +pump for the third one okay that's 2 + + align:start position:0% +pump for the third one okay that's 2 + + + align:start position:0% +pump for the third one okay that's 2 +Omega P minus Omega s so uh typically + + align:start position:0% +Omega P minus Omega s so uh typically + + + align:start position:0% +Omega P minus Omega s so uh typically +you know you might imagine a green beam + + align:start position:0% +you know you might imagine a green beam + + + align:start position:0% +you know you might imagine a green beam +going in for the pump and a red one for + + align:start position:0% +going in for the pump and a red one for + + + align:start position:0% +going in for the pump and a red one for +the + + align:start position:0% +the + + + align:start position:0% +the +Stokes um and what you see where is that + + align:start position:0% +Stokes um and what you see where is that + + + align:start position:0% +Stokes um and what you see where is that +uh you know you might have a green pump + + align:start position:0% +uh you know you might have a green pump + + + align:start position:0% +uh you know you might have a green pump +and a red Stokes and you'll see sort of + + align:start position:0% +and a red Stokes and you'll see sort of + + + align:start position:0% +and a red Stokes and you'll see sort of +a blue spot out to the side um and you + + align:start position:0% +a blue spot out to the side um and you + + + align:start position:0% +a blue spot out to the side um and you +can understand that then immediately + + align:start position:0% +can understand that then immediately + + + align:start position:0% +can understand that then immediately +from this because it also immediately + + align:start position:0% +from this because it also immediately + + + align:start position:0% +from this because it also immediately +says that the wave Vector matching for + + align:start position:0% +says that the wave Vector matching for + + + align:start position:0% +says that the wave Vector matching for +the + + align:start position:0% +the + + + align:start position:0% +the +experiment is um two two momenta units + + align:start position:0% +experiment is um two two momenta units + + + align:start position:0% +experiment is um two two momenta units +of momenta coming from the pump minus + + align:start position:0% +of momenta coming from the pump minus + + + align:start position:0% +of momenta coming from the pump minus +one of the Stokes and that leads to the + + align:start position:0% +one of the Stokes and that leads to the + + + align:start position:0% +one of the Stokes and that leads to the +wave Vector matching condition that I've + + align:start position:0% +wave Vector matching condition that I've + + + align:start position:0% +wave Vector matching condition that I've +drawn up there right that um we're going + + align:start position:0% +drawn up there right that um we're going + + + align:start position:0% +drawn up there right that um we're going +in the forward Direction and we bring in + + align:start position:0% +in the forward Direction and we bring in + + + align:start position:0% +in the forward Direction and we bring in +the Stokes at an angle the signal field + + align:start position:0% +the Stokes at an angle the signal field + + + align:start position:0% +the Stokes at an angle the signal field +um will come out at a particular + + align:start position:0% +um will come out at a particular + + + align:start position:0% +um will come out at a particular +Direction dictated by the frequency and + + align:start position:0% +Direction dictated by the frequency and + + + align:start position:0% +Direction dictated by the frequency and +wave Vector matching in One Direction + + align:start position:0% +wave Vector matching in One Direction + + + align:start position:0% +wave Vector matching in One Direction +and when you're doing this with + + align:start position:0% +and when you're doing this with + + + align:start position:0% +and when you're doing this with +well-defined frequencies then the wave + + align:start position:0% +well-defined frequencies then the wave + + + align:start position:0% +well-defined frequencies then the wave +Vector issues that we talked about + + align:start position:0% +Vector issues that we talked about + + + align:start position:0% +Vector issues that we talked about +yesterday come into play and the angle + + align:start position:0% +yesterday come into play and the angle + + + align:start position:0% +yesterday come into play and the angle +between the pump and the Stokes become + + align:start position:0% +between the pump and the Stokes become + + + align:start position:0% +between the pump and the Stokes become +really critical to get an efficient uh + + align:start position:0% +really critical to get an efficient uh + + + align:start position:0% +really critical to get an efficient uh +signal generation okay but uh so you can + + align:start position:0% +signal generation okay but uh so you can + + + align:start position:0% +signal generation okay but uh so you can +see here if you now do this with um time + + align:start position:0% +see here if you now do this with um time + + + align:start position:0% +see here if you now do this with um time +resolved pulses that you can move the + + align:start position:0% +resolved pulses that you can move the + + + align:start position:0% +resolved pulses that you can move the +time delay between these pump and probe + + align:start position:0% +time delay between these pump and probe + + + align:start position:0% +time delay between these pump and probe +and that just gives you the vibrational + + align:start position:0% +and that just gives you the vibrational + + + align:start position:0% +and that just gives you the vibrational +Dynamics in the system and that is the + + align:start position:0% +Dynamics in the system and that is the + + + align:start position:0% +Dynamics in the system and that is the +time domain version of a Ramen Spectrum + + align:start position:0% +time domain version of a Ramen Spectrum + + + align:start position:0% +time domain version of a Ramen Spectrum +right in the limit that you go to very + + align:start position:0% +right in the limit that you go to very + + + align:start position:0% +right in the limit that you go to very +short pulses um with the same color you + + align:start position:0% +short pulses um with the same color you + + + align:start position:0% +short pulses um with the same color you +should recognize that the transient + + align:start position:0% +should recognize that the transient + + + align:start position:0% +should recognize that the transient +grading experiments we did correspond to + + align:start position:0% +grading experiments we did correspond to + + + align:start position:0% +grading experiments we did correspond to +this process also where this difference + + align:start position:0% +this process also where this difference + + + align:start position:0% +this process also where this difference +in colors these are colors that both lie + + align:start position:0% +in colors these are colors that both lie + + + align:start position:0% +in colors these are colors that both lie +within the bandwidth of the exitation + + align:start position:0% +within the bandwidth of the exitation + + + align:start position:0% +within the bandwidth of the exitation +fields okay so you can imagine that + + align:start position:0% +fields okay so you can imagine that + + + align:start position:0% +fields okay so you can imagine that +you're there's enough colors in your + + align:start position:0% +you're there's enough colors in your + + + align:start position:0% +you're there's enough colors in your +short pulses that they span this whole + + align:start position:0% +short pulses that they span this whole + + + align:start position:0% +short pulses that they span this whole +the bandwidth spans this whole region so + + align:start position:0% +the bandwidth spans this whole region so + + + align:start position:0% +the bandwidth spans this whole region so +okay so they they they can't they don't + + align:start position:0% +okay so they they they can't they don't + + + align:start position:0% +okay so they they they can't they don't +need to be different colors + + align:start position:0% + + + + align:start position:0% + +okay all right any yep when people do + + align:start position:0% +okay all right any yep when people do + + + align:start position:0% +okay all right any yep when people do +these cars experiments do they bring in + + align:start position:0% +these cars experiments do they bring in + + + align:start position:0% +these cars experiments do they bring in +a local oscillator at some point to + + align:start position:0% +a local oscillator at some point to + + + align:start position:0% +a local oscillator at some point to +heter Signal + + align:start position:0% + + + + align:start position:0% + +or um + + align:start position:0% + + + + align:start position:0% + +so uh yes and no there's uh you you know + + align:start position:0% +so uh yes and no there's uh you you know + + + align:start position:0% +so uh yes and no there's uh you you know +in terms of people doing coherent Ramen + + align:start position:0% +in terms of people doing coherent Ramen + + + align:start position:0% +in terms of people doing coherent Ramen +with heterodon detection I think there's + + align:start position:0% +with heterodon detection I think there's + + + align:start position:0% +with heterodon detection I think there's +not many people that are going a whole + + align:start position:0% +not many people that are going a whole + + + align:start position:0% +not many people that are going a whole +lot further than the Nelson group does + + align:start position:0% +lot further than the Nelson group does + + + align:start position:0% +lot further than the Nelson group does +right um although you know with multiple + + align:start position:0% +right um although you know with multiple + + + align:start position:0% +right um although you know with multiple +colors now that + + align:start position:0% +colors now that + + + align:start position:0% +colors now that +happens there are a handful of coherent + + align:start position:0% +happens there are a handful of coherent + + + align:start position:0% +happens there are a handful of coherent +Ramen experiments that do this + + align:start position:0% +Ramen experiments that do this + + + align:start position:0% +Ramen experiments that do this +um shall we say unintentionally and I + + align:start position:0% +um shall we say unintentionally and I + + + align:start position:0% +um shall we say unintentionally and I +think the F to Second you know the + + align:start position:0% +think the F to Second you know the + + + align:start position:0% +think the F to Second you know the +stimulated Ramen spectroscopy that rich + + align:start position:0% +stimulated Ramen spectroscopy that rich + + + align:start position:0% +stimulated Ramen spectroscopy that rich +Matthews does is an example of this + + align:start position:0% +Matthews does is an example of this + + + align:start position:0% +Matthews does is an example of this +where it's uh sort of intrinsically + + align:start position:0% +where it's uh sort of intrinsically + + + align:start position:0% +where it's uh sort of intrinsically +heter roded sort of like um the pump + + align:start position:0% +heter roded sort of like um the pump + + + align:start position:0% +heter roded sort of like um the pump +probe experiment um I'm actually hoping + + align:start position:0% +probe experiment um I'm actually hoping + + + align:start position:0% +probe experiment um I'm actually hoping +I can spend a whole you know a whole + + align:start position:0% +I can spend a whole you know a whole + + + align:start position:0% +I can spend a whole you know a whole +chunk of time on coherent Ramen because + + align:start position:0% +chunk of time on coherent Ramen because + + + align:start position:0% +chunk of time on coherent Ramen because +there's a whole slug of interesting you + + align:start position:0% +there's a whole slug of interesting you + + + align:start position:0% +there's a whole slug of interesting you +know techniques and you do them with and + + align:start position:0% +know techniques and you do them with and + + + align:start position:0% +know techniques and you do them with and +without header dining and um lot lots of + + align:start position:0% +without header dining and um lot lots of + + + align:start position:0% +without header dining and um lot lots of +interesting information to get out of + + align:start position:0% +interesting information to get out of + + + align:start position:0% +interesting information to get out of +that but + + align:start position:0% +that but + + + align:start position:0% +that but +but + + align:start position:0% +but + + + align:start position:0% +but +uh it's the header dining idea has even + + align:start position:0% +uh it's the header dining idea has even + + + align:start position:0% +uh it's the header dining idea has even +been used header dining cars has also + + align:start position:0% +been used header dining cars has also + + + align:start position:0% +been used header dining cars has also +been used for Imaging um that sunish + + align:start position:0% +been used for Imaging um that sunish + + + align:start position:0% +been used for Imaging um that sunish +she's been doing some of that although + + align:start position:0% +she's been doing some of that although + + + align:start position:0% +she's been doing some of that although +I'm not sure if he's real fond of doing + + align:start position:0% +I'm not sure if he's real fond of doing + + + align:start position:0% +I'm not sure if he's real fond of doing +that really tough + + align:start position:0% +that really tough + + + align:start position:0% +that really tough +experiment he's fond of tough + + align:start position:0% +experiment he's fond of tough + + + align:start position:0% +experiment he's fond of tough +experiments + + align:start position:0% +experiments + + + align:start position:0% +experiments +yeah another point is that so most + + align:start position:0% +yeah another point is that so most + + + align:start position:0% +yeah another point is that so most +people do this in the in the frequency + + align:start position:0% +people do this in the in the frequency + + + align:start position:0% +people do this in the in the frequency +domain in the frequency domain it's + + align:start position:0% +domain in the frequency domain it's + + + align:start position:0% +domain in the frequency domain it's +important that you + + align:start position:0% +important that you + + + align:start position:0% +important that you +little okay people usually have two + + align:start position:0% +little okay people usually have two + + + align:start position:0% +little okay people usually have two +green like the two Mega pumps the same + + align:start position:0% +green like the two Mega pumps the same + + + align:start position:0% +green like the two Mega pumps the same +beam right in principle they don't have + + align:start position:0% +beam right in principle they don't have + + + align:start position:0% +beam right in principle they don't have +to be so what's important if you do this + + align:start position:0% +to be so what's important if you do this + + + align:start position:0% +to be so what's important if you do this +in the frequency domain is that your + + align:start position:0% +in the frequency domain is that your + + + align:start position:0% +in the frequency domain is that your +last beam your last Mega pump is narrow + + align:start position:0% +last beam your last Mega pump is narrow + + + align:start position:0% +last beam your last Mega pump is narrow +P so if not you can wash out + + align:start position:0% +P so if not you can wash out + + + align:start position:0% +P so if not you can wash out +your your your frequency resolution is + + align:start position:0% +your your your frequency resolution is + + + align:start position:0% +your your your frequency resolution is +it's it's depending on your last so you + + align:start position:0% +it's it's depending on your last so you + + + align:start position:0% +it's it's depending on your last so you +need to have a narrow Pand mhm right + + align:start position:0% +need to have a narrow Pand mhm right + + + align:start position:0% +need to have a narrow Pand mhm right +there yeah yeah thanks thanks for + + align:start position:0% +there yeah yeah thanks thanks for + + + align:start position:0% +there yeah yeah thanks thanks for +pointing that out there's so what I + + align:start position:0% +pointing that out there's so what I + + + align:start position:0% +pointing that out there's so what I +described was sort of the time domain + + align:start position:0% +described was sort of the time domain + + + align:start position:0% +described was sort of the time domain +limit um thinking about this as a Time + + align:start position:0% +limit um thinking about this as a Time + + + align:start position:0% +limit um thinking about this as a Time +domain experiment in which you use a you + + align:start position:0% +domain experiment in which you use a you + + + align:start position:0% +domain experiment in which you use a you +know short pair of pulses to create a + + align:start position:0% +know short pair of pulses to create a + + + align:start position:0% +know short pair of pulses to create a +vibration you listen to it and and + + align:start position:0% +vibration you listen to it and and + + + align:start position:0% +vibration you listen to it and and +you're controlling that time variable + + align:start position:0% +you're controlling that time variable + + + align:start position:0% +you're controlling that time variable +the other approach is like Paul was + + align:start position:0% +the other approach is like Paul was + + + align:start position:0% +the other approach is like Paul was +saying is treated it as a frequency + + align:start position:0% +saying is treated it as a frequency + + + align:start position:0% +saying is treated it as a frequency +domain experiment you I mean you you + + align:start position:0% +domain experiment you I mean you you + + + align:start position:0% +domain experiment you I mean you you +still in principle have this you know + + align:start position:0% +still in principle have this you know + + + align:start position:0% +still in principle have this you know +control over um this time delay but uh + + align:start position:0% +control over um this time delay but uh + + + align:start position:0% +control over um this time delay but uh +it's very often that you might actually + + align:start position:0% +it's very often that you might actually + + + align:start position:0% +it's very often that you might actually +want + + align:start position:0% +want + + + align:start position:0% +want +to excite a range of Transitions and + + align:start position:0% +to excite a range of Transitions and + + + align:start position:0% +to excite a range of Transitions and +look at the frequency dependent changes + + align:start position:0% +look at the frequency dependent changes + + + align:start position:0% +look at the frequency dependent changes +and um by spectrally dispersing you know + + align:start position:0% +and um by spectrally dispersing you know + + + align:start position:0% +and um by spectrally dispersing you know +what comes out as a signal and then + + align:start position:0% +what comes out as a signal and then + + + align:start position:0% +what comes out as a signal and then +Paul's right is because the virtual + + align:start position:0% +Paul's right is because the virtual + + + align:start position:0% +Paul's right is because the virtual +state is at any frequency you want you + + align:start position:0% +state is at any frequency you want you + + + align:start position:0% +state is at any frequency you want you +want to use a uh combination of short + + align:start position:0% +want to use a uh combination of short + + + align:start position:0% +want to use a uh combination of short +exitation and narrow band probing to uh + + align:start position:0% +exitation and narrow band probing to uh + + + align:start position:0% +exitation and narrow band probing to uh +give you the both the time and the + + align:start position:0% +give you the both the time and the + + + align:start position:0% +give you the both the time and the +frequency resolution + + align:start position:0% + + + + align:start position:0% + +okay any questions so I think now is a + + align:start position:0% +okay any questions so I think now is a + + + align:start position:0% +okay any questions so I think now is a +good time to take a + + align:start position:0% +good time to take a + + + align:start position:0% +good time to take a +break all right folks um what I'd like + + align:start position:0% +break all right folks um what I'd like + + + align:start position:0% +break all right folks um what I'd like +to do + + align:start position:0% +to do + + + align:start position:0% +to do +is sort of get into an introduction to + + align:start position:0% +is sort of get into an introduction to + + + align:start position:0% +is sort of get into an introduction to +two-dimensional spectroscopy a little + + align:start position:0% +two-dimensional spectroscopy a little + + + align:start position:0% +two-dimensional spectroscopy a little +bit of motivating why you do it and sort + + align:start position:0% +bit of motivating why you do it and sort + + + align:start position:0% +bit of motivating why you do it and sort +of the general ideas behind + + align:start position:0% +of the general ideas behind + + + align:start position:0% +of the general ideas behind +it and but I want to motivated by the + + align:start position:0% +it and but I want to motivated by the + + + align:start position:0% +it and but I want to motivated by the +couple of the examples I gave at the + + align:start position:0% +couple of the examples I gave at the + + + align:start position:0% +couple of the examples I gave at the +beginning you know why you do nonlinear + + align:start position:0% +beginning you know why you do nonlinear + + + align:start position:0% +beginning you know why you do nonlinear +spectroscopy you know it's if I have a + + align:start position:0% +spectroscopy you know it's if I have a + + + align:start position:0% +spectroscopy you know it's if I have a +linear experiment I see two peaks you + + align:start position:0% +linear experiment I see two peaks you + + + align:start position:0% +linear experiment I see two peaks you +know what uh do I use to interpret what + + align:start position:0% +know what uh do I use to interpret what + + + align:start position:0% +know what uh do I use to interpret what +the origin of those Peaks are I could + + align:start position:0% +the origin of those Peaks are I could + + + align:start position:0% +the origin of those Peaks are I could +imagine there are two two entirely + + align:start position:0% +imagine there are two two entirely + + + align:start position:0% +imagine there are two two entirely +different molecules spatially separated + + align:start position:0% +different molecules spatially separated + + + align:start position:0% +different molecules spatially separated +don't know about each other and they + + align:start position:0% +don't know about each other and they + + + align:start position:0% +don't know about each other and they +give rise to these Peaks I can also + + align:start position:0% +give rise to these Peaks I can also + + + align:start position:0% +give rise to these Peaks I can also +imagine that um these arise from igen + + align:start position:0% +imagine that um these arise from igen + + + align:start position:0% +imagine that um these arise from igen +states that reflect the coupling between + + align:start position:0% +states that reflect the coupling between + + + align:start position:0% +states that reflect the coupling between +different um electronic or vibrational + + align:start position:0% +different um electronic or vibrational + + + align:start position:0% +different um electronic or vibrational +States how do you distinguish + + align:start position:0% +States how do you distinguish + + + align:start position:0% +States how do you distinguish +them the other example which is sort of + + align:start position:0% +them the other example which is sort of + + + align:start position:0% +them the other example which is sort of +analogous is you know if you have a very + + align:start position:0% +analogous is you know if you have a very + + + align:start position:0% +analogous is you know if you have a very +broad line do you think of that is that + + align:start position:0% +broad line do you think of that is that + + + align:start position:0% +broad line do you think of that is that +an inhomogeneous line or not how would + + align:start position:0% +an inhomogeneous line or not how would + + + align:start position:0% +an inhomogeneous line or not how would +you go about tackling these problems + + align:start position:0% +you go about tackling these problems + + + align:start position:0% +you go about tackling these problems +um so uh you know I think the there's a + + align:start position:0% +um so uh you know I think the there's a + + + align:start position:0% +um so uh you know I think the there's a +real simple exercise that tells you that + + align:start position:0% +real simple exercise that tells you that + + + align:start position:0% +real simple exercise that tells you that +you should be able to solve these + + align:start position:0% +you should be able to solve these + + + align:start position:0% +you should be able to solve these +problems if you do on probe experiments + + align:start position:0% +problems if you do on probe experiments + + + align:start position:0% +problems if you do on probe experiments +um of the kind that we just discussed + + align:start position:0% +um of the kind that we just discussed + + + align:start position:0% +um of the kind that we just discussed +and what um we talked about is that with + + align:start position:0% +and what um we talked about is that with + + + align:start position:0% +and what um we talked about is that with +um pum + + align:start position:0% + + + + align:start position:0% + +probes that we have three independent + + align:start position:0% +probes that we have three independent + + + align:start position:0% +probes that we have three independent +variables and we tend to think of these + + align:start position:0% +variables and we tend to think of these + + + align:start position:0% +variables and we tend to think of these +I mean when we write out response + + align:start position:0% +I mean when we write out response + + + align:start position:0% +I mean when we write out response +functions we have three independent time + + align:start position:0% +functions we have three independent time + + + align:start position:0% +functions we have three independent time +variables but for pump probes you can + + align:start position:0% +variables but for pump probes you can + + + align:start position:0% +variables but for pump probes you can +think of these as sort of being + + align:start position:0% +think of these as sort of being + + + align:start position:0% +think of these as sort of being +the frequency of the pump + + align:start position:0% +the frequency of the pump + + + align:start position:0% +the frequency of the pump +field uh time delay between the pump and + + align:start position:0% +field uh time delay between the pump and + + + align:start position:0% +field uh time delay between the pump and +the prob and frequency + + align:start position:0% +the prob and frequency + + + align:start position:0% +the prob and frequency +Pro and um now let's just actually sort + + align:start position:0% +Pro and um now let's just actually sort + + + align:start position:0% +Pro and um now let's just actually sort +of consider the case where this is + + align:start position:0% +of consider the case where this is + + + align:start position:0% +of consider the case where this is +really a frequency domain experiment + + align:start position:0% +really a frequency domain experiment + + + align:start position:0% +really a frequency domain experiment +just a double resonance experiment in + + align:start position:0% +just a double resonance experiment in + + + align:start position:0% +just a double resonance experiment in +which we independently control the + + align:start position:0% +which we independently control the + + + align:start position:0% +which we independently control the +frequency of the pump and the problem so + + align:start position:0% +frequency of the pump and the problem so + + + align:start position:0% +frequency of the pump and the problem so +this is sort of what I refer to as + + align:start position:0% +this is sort of what I refer to as + + + align:start position:0% +this is sort of what I refer to as +double resonance to + + align:start position:0% +double resonance to + + + align:start position:0% +double resonance to +the yeah by the way he said ideas have + + align:start position:0% +the yeah by the way he said ideas have + + + align:start position:0% +the yeah by the way he said ideas have +been around forever the only things that + + align:start position:0% +been around forever the only things that + + + align:start position:0% +been around forever the only things that +are new these days is the ways of doing + + align:start position:0% +are new these days is the ways of doing + + + align:start position:0% +are new these days is the ways of doing +them and think about the nonlinear + + align:start position:0% +them and think about the nonlinear + + + align:start position:0% +them and think about the nonlinear +response in terms of a huge two or three + + align:start position:0% +response in terms of a huge two or three + + + align:start position:0% +response in terms of a huge two or three +dimensional + + align:start position:0% + + + + align:start position:0% + +surface okay so let's do that and apply + + align:start position:0% +surface okay so let's do that and apply + + + align:start position:0% +surface okay so let's do that and apply +it to these two problems okay and so + + align:start position:0% +it to these two problems okay and so + + + align:start position:0% +it to these two problems okay and so +here's how we're going to do this + + align:start position:0% +here's how we're going to do this + + + align:start position:0% +here's how we're going to do this +um as before cross two beams in a sample + + align:start position:0% +um as before cross two beams in a sample + + + align:start position:0% +um as before cross two beams in a sample +um here's + + align:start position:0% + + + + align:start position:0% + +my probe here's my FR I'm going to put + + align:start position:0% +my probe here's my FR I'm going to put + + + align:start position:0% +my probe here's my FR I'm going to put +it detector on here and measure the + + align:start position:0% +it detector on here and measure the + + + align:start position:0% +it detector on here and measure the +change of intensity on there as a result + + align:start position:0% +change of intensity on there as a result + + + align:start position:0% +change of intensity on there as a result +of this + + align:start position:0% +of this + + + align:start position:0% +of this +field and I'm going to start with the + + align:start position:0% +field and I'm going to start with the + + + align:start position:0% +field and I'm going to start with the +Spectrum and I measure that with + + align:start position:0% +Spectrum and I measure that with + + + align:start position:0% +Spectrum and I measure that with +my probe field so called this Mega probe + + align:start position:0% +my probe field so called this Mega probe + + + align:start position:0% +my probe field so called this Mega probe +and now imagine that I T my pump + + align:start position:0% +and now imagine that I T my pump + + + align:start position:0% +and now imagine that I T my pump +beam to be on resonance with the + + align:start position:0% + + + + align:start position:0% + +state um so what could happen well + + align:start position:0% +state um so what could happen well + + + align:start position:0% +state um so what could happen well +actually just uh to make it more + + align:start position:0% +actually just uh to make it more + + + align:start position:0% +actually just uh to make it more +interesting let's put a + + align:start position:0% + + + + align:start position:0% + +third so one way of thinking what might + + align:start position:0% +third so one way of thinking what might + + + align:start position:0% +third so one way of thinking what might +happen just uh take the extremely + + align:start position:0% +happen just uh take the extremely + + + align:start position:0% +happen just uh take the extremely +intense limit there is a poor molecule + + align:start position:0% +intense limit there is a poor molecule + + + align:start position:0% +intense limit there is a poor molecule +that's sitting under that frequency that + + align:start position:0% +that's sitting under that frequency that + + + align:start position:0% +that's sitting under that frequency that +is just going to get obliterated we're + + align:start position:0% +is just going to get obliterated we're + + + align:start position:0% +is just going to get obliterated we're +just going to destroy it + + align:start position:0% +just going to destroy it + + + align:start position:0% +just going to destroy it +photochemically bang it's gone what + + align:start position:0% +photochemically bang it's gone what + + + align:start position:0% +photochemically bang it's gone what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +if you know if you sort of somehow + + align:start position:0% +if you know if you sort of somehow + + + align:start position:0% +if you know if you sort of somehow +remove that set of + + align:start position:0% +remove that set of + + + align:start position:0% +remove that set of +molecules um means you've really removed + + align:start position:0% +molecules um means you've really removed + + + align:start position:0% +molecules um means you've really removed +the possibility to make absorption of + + align:start position:0% +the possibility to make absorption of + + + align:start position:0% +the possibility to make absorption of +any of those frequencies so really any + + align:start position:0% +any of those frequencies so really any + + + align:start position:0% +any of those frequencies so really any +sort of uh other transition that + + align:start position:0% +sort of uh other transition that + + + align:start position:0% +sort of uh other transition that +originated from that same molecule will + + align:start position:0% +originated from that same molecule will + + + align:start position:0% +originated from that same molecule will +also be + + align:start position:0% +also be + + + align:start position:0% +also be +done okay so you know imagine we go + + align:start position:0% +done okay so you know imagine we go + + + align:start position:0% +done okay so you know imagine we go +through now and we add the pump and we + + align:start position:0% +through now and we add the pump and we + + + align:start position:0% +through now and we add the pump and we +see that oh this intensity drops this + + align:start position:0% +see that oh this intensity drops this + + + align:start position:0% +see that oh this intensity drops this +one doesn't this one does says point you + + align:start position:0% +one doesn't this one does says point you + + + align:start position:0% +one doesn't this one does says point you +know you know immediately know that + + align:start position:0% +know you know immediately know that + + + align:start position:0% +know you know immediately know that +there's a spectal correlation between + + align:start position:0% +there's a spectal correlation between + + + align:start position:0% +there's a spectal correlation between +that Peak and this peak and it's the + + align:start position:0% +that Peak and this peak and it's the + + + align:start position:0% +that Peak and this peak and it's the +same molecule you destroyed it so what + + align:start position:0% +same molecule you destroyed it so what + + + align:start position:0% +same molecule you destroyed it so what +we are talking about in a you know in a + + align:start position:0% +we are talking about in a you know in a + + + align:start position:0% +we are talking about in a you know in a +more General two-dimensional experiment + + align:start position:0% +more General two-dimensional experiment + + + align:start position:0% +more General two-dimensional experiment +is that we're looking at the same sorts + + align:start position:0% +is that we're looking at the same sorts + + + align:start position:0% +is that we're looking at the same sorts +of molecular couplings that transfer + + align:start position:0% +of molecular couplings that transfer + + + align:start position:0% +of molecular couplings that transfer +energy from one state to another and + + align:start position:0% +energy from one state to another and + + + align:start position:0% +energy from one state to another and +that means that bleaching one transition + + align:start position:0% +that means that bleaching one transition + + + align:start position:0% +that means that bleaching one transition +will lead to bleaches in other couple of + + align:start position:0% +will lead to bleaches in other couple of + + + align:start position:0% +will lead to bleaches in other couple of +transitions so um what this means is now + + align:start position:0% +transitions so um what this means is now + + + align:start position:0% +transitions so um what this means is now +your change of intensity as a function + + align:start position:0% +your change of intensity as a function + + + align:start position:0% +your change of intensity as a function +of the prob is going to be positive and + + align:start position:0% +of the prob is going to be positive and + + + align:start position:0% +of the prob is going to be positive and +positive here no change in between and + + align:start position:0% +positive here no change in between and + + + align:start position:0% +positive here no change in between and +now think of this as one slice through a + + align:start position:0% +now think of this as one slice through a + + + align:start position:0% +now think of this as one slice through a +two-dimensional surface right now repeat + + align:start position:0% +two-dimensional surface right now repeat + + + align:start position:0% +two-dimensional surface right now repeat +that experiment for all possible pump + + align:start position:0% +that experiment for all possible pump + + + align:start position:0% +that experiment for all possible pump +frequencies and now make up a map of + + align:start position:0% +frequencies and now make up a map of + + + align:start position:0% +frequencies and now make up a map of +this Delta I as + + align:start position:0% +this Delta I as + + + align:start position:0% +this Delta I as +pumping the + + align:start position:0% +pumping the + + + align:start position:0% +pumping the +pump and the probe frequency so this is + + align:start position:0% +pump and the probe frequency so this is + + + align:start position:0% +pump and the probe frequency so this is +one + + align:start position:0% + + + + align:start position:0% + +slice vertically through + + align:start position:0% +slice vertically through + + + align:start position:0% +slice vertically through +here and it happens to be at on + + align:start position:0% +here and it happens to be at on + + + align:start position:0% +here and it happens to be at on +resonance with that be you map this all + + align:start position:0% +resonance with that be you map this all + + + align:start position:0% +resonance with that be you map this all +out and you would expect to see a + + align:start position:0% +out and you would expect to see a + + + align:start position:0% +out and you would expect to see a +spectrum that + + align:start position:0% +spectrum that + + + align:start position:0% +spectrum that +looks about like + + align:start position:0% +looks about like + + + align:start position:0% +looks about like +this this is sort of the diagonal + + align:start position:0% +this this is sort of the diagonal + + + align:start position:0% +this this is sort of the diagonal +frequency AIS so what is the Spectrum + + align:start position:0% +frequency AIS so what is the Spectrum + + + align:start position:0% +frequency AIS so what is the Spectrum +report to you it says these uh cross + + align:start position:0% +report to you it says these uh cross + + + align:start position:0% +report to you it says these uh cross +Peaks that is um changes in intensity at + + align:start position:0% +Peaks that is um changes in intensity at + + + align:start position:0% +Peaks that is um changes in intensity at +frequencies different than where you + + align:start position:0% +frequencies different than where you + + + align:start position:0% +frequencies different than where you +pumped is telling you about uh the + + align:start position:0% +pumped is telling you about uh the + + + align:start position:0% +pumped is telling you about uh the +correlation between spectral features it + + align:start position:0% +correlation between spectral features it + + + align:start position:0% +correlation between spectral features it +tells you about you know microscopic + + align:start position:0% +tells you about you know microscopic + + + align:start position:0% +tells you about you know microscopic +interactions this tells you this peak is + + align:start position:0% +interactions this tells you this peak is + + + align:start position:0% +interactions this tells you this peak is +not correlated with other ones whereas + + align:start position:0% +not correlated with other ones whereas + + + align:start position:0% +not correlated with other ones whereas +this one is or you can take the other + + align:start position:0% +this one is or you can take the other + + + align:start position:0% +this one is or you can take the other +limit you know the intensity of those + + align:start position:0% +limit you know the intensity of those + + + align:start position:0% +limit you know the intensity of those +Peaks will tell you how strongly they + + align:start position:0% +Peaks will tell you how strongly they + + + align:start position:0% +Peaks will tell you how strongly they +interact so that's one way of um ironing + + align:start position:0% +interact so that's one way of um ironing + + + align:start position:0% +interact so that's one way of um ironing +it out I'll take the same approach and + + align:start position:0% +it out I'll take the same approach and + + + align:start position:0% +it out I'll take the same approach and +yeah as a practical question is there + + align:start position:0% +yeah as a practical question is there + + + align:start position:0% +yeah as a practical question is there +ever any utility in placing your Omega + + align:start position:0% +ever any utility in placing your Omega + + + align:start position:0% +ever any utility in placing your Omega +pump where you don't have a peak in + + align:start position:0% +pump where you don't have a peak in + + + align:start position:0% +pump where you don't have a peak in +theeg Pro Spectrum where you just + + align:start position:0% +theeg Pro Spectrum where you just + + + align:start position:0% +theeg Pro Spectrum where you just +wasting time by okay uh I'm just uh so + + align:start position:0% +wasting time by okay uh I'm just uh so + + + align:start position:0% +wasting time by okay uh I'm just uh so +when it comes to practical stuff then + + align:start position:0% +when it comes to practical stuff then + + + align:start position:0% +when it comes to practical stuff then +how you do it is going to be different + + align:start position:0% +how you do it is going to be different + + + align:start position:0% +how you do it is going to be different +but so I'm just saying this sort from a + + align:start position:0% +but so I'm just saying this sort from a + + + align:start position:0% +but so I'm just saying this sort from a +conceptual point of view um if you it is + + align:start position:0% +conceptual point of view um if you it is + + + align:start position:0% +conceptual point of view um if you it is +true you know if you know the linear + + align:start position:0% +true you know if you know the linear + + + align:start position:0% +true you know if you know the linear +experiment and you know the pump + + align:start position:0% +experiment and you know the pump + + + align:start position:0% +experiment and you know the pump +interaction then you at least know in + + align:start position:0% +interaction then you at least know in + + + align:start position:0% +interaction then you at least know in +one dimension where to go + + align:start position:0% +one dimension where to go + + + align:start position:0% +one dimension where to go +scan and it doesn't count for the other + + align:start position:0% +scan and it doesn't count for the other + + + align:start position:0% +scan and it doesn't count for the other +dimension um but uh because you can open + + align:start position:0% +dimension um but uh because you can open + + + align:start position:0% +dimension um but uh because you can open +up new transitions with the first + + align:start position:0% +up new transitions with the first + + + align:start position:0% +up new transitions with the first +interaction that you didn't know about + + align:start position:0% +interaction that you didn't know about + + + align:start position:0% +interaction that you didn't know about +but it is true + + align:start position:0% +but it is true + + + align:start position:0% +but it is true +absolutely if you've got a sparse + + align:start position:0% +absolutely if you've got a sparse + + + align:start position:0% +absolutely if you've got a sparse +Spectrum then you know you have a + + align:start position:0% +Spectrum then you know you have a + + + align:start position:0% +Spectrum then you know you have a +limited set of areas to + + align:start position:0% +limited set of areas to + + + align:start position:0% +limited set of areas to +go this is the whole reason why I think + + align:start position:0% +go this is the whole reason why I think + + + align:start position:0% +go this is the whole reason why I think +you know the large fraction of high + + align:start position:0% +you know the large fraction of high + + + align:start position:0% +you know the large fraction of high +quality gas space spectroscopy really + + align:start position:0% +quality gas space spectroscopy really + + + align:start position:0% +quality gas space spectroscopy really +falls into this class of it's it's two + + align:start position:0% +falls into this class of it's it's two + + + align:start position:0% +falls into this class of it's it's two +dimensional spectroscopy it's just it's + + align:start position:0% +dimensional spectroscopy it's just it's + + + align:start position:0% +dimensional spectroscopy it's just it's +presented as slices through you know a + + align:start position:0% +presented as slices through you know a + + + align:start position:0% +presented as slices through you know a +surface well because they're they're not + + align:start position:0% +surface well because they're they're not + + + align:start position:0% +surface well because they're they're not +they're not part so it's very hard to + + align:start position:0% +they're not part so it's very hard to + + + align:start position:0% +they're not part so it's very hard to +visualizing there right so then we start + + align:start position:0% +visualizing there right so then we start + + + align:start position:0% +visualizing there right so then we start +getting into of the Practical issues + + align:start position:0% +getting into of the Practical issues + + + align:start position:0% +getting into of the Practical issues +about why would you do an experiment one + + align:start position:0% +about why would you do an experiment one + + + align:start position:0% +about why would you do an experiment one +way or another and imagine mix time you + + align:start position:0% +way or another and imagine mix time you + + + align:start position:0% +way or another and imagine mix time you +can imagine this is talked about this is + + align:start position:0% +can imagine this is talked about this is + + + align:start position:0% +can imagine this is talked about this is +a frequency domain experiment talk about + + align:start position:0% +a frequency domain experiment talk about + + + align:start position:0% +a frequency domain experiment talk about +time domain and there's practical + + align:start position:0% + + + + align:start position:0% + +isues okay so um but but one thing that + + align:start position:0% +isues okay so um but but one thing that + + + align:start position:0% +isues okay so um but but one thing that +you know is great about 2D is that there + + align:start position:0% +you know is great about 2D is that there + + + align:start position:0% +you know is great about 2D is that there +is a great power of visualizing all of + + align:start position:0% +is a great power of visualizing all of + + + align:start position:0% +is a great power of visualizing all of +the interactions in one certain spect + + align:start position:0% +the interactions in one certain spect + + + align:start position:0% +the interactions in one certain spect +there there's a lot to that in + + align:start position:0% +there there's a lot to that in + + + align:start position:0% +there there's a lot to that in +mind this gets back to the issue of a + + align:start position:0% +mind this gets back to the issue of a + + + align:start position:0% +mind this gets back to the issue of a +spectroscop is only as good as it can + + align:start position:0% +spectroscop is only as good as it can + + + align:start position:0% +spectroscop is only as good as it can +distinguish different models and and + + align:start position:0% +distinguish different models and and + + + align:start position:0% +distinguish different models and and +it's I mean it may just be me being a + + align:start position:0% +it's I mean it may just be me being a + + + align:start position:0% +it's I mean it may just be me being a +visual learner but when you sort of see + + align:start position:0% +visual learner but when you sort of see + + + align:start position:0% +visual learner but when you sort of see +the interaction system is mapped out in + + align:start position:0% +the interaction system is mapped out in + + + align:start position:0% +the interaction system is mapped out in +front of you it really gives you this + + align:start position:0% +front of you it really gives you this + + + align:start position:0% +front of you it really gives you this +Insight okay so let's let's apply the + + align:start position:0% +Insight okay so let's let's apply the + + + align:start position:0% +Insight okay so let's let's apply the +same example then to this inhomogeneous + + align:start position:0% +same example then to this inhomogeneous + + + align:start position:0% +same example then to this inhomogeneous +line shape so now these are both CW yeah + + align:start position:0% +line shape so now these are both CW yeah + + + align:start position:0% +line shape so now these are both CW yeah +just think of them well um well defined + + align:start position:0% +just think of them well um well defined + + + align:start position:0% +just think of them well um well defined +frequencies + + align:start position:0% +frequencies + + + align:start position:0% +frequencies +narrow okay um now now imagine say we + + align:start position:0% +narrow okay um now now imagine say we + + + align:start position:0% +narrow okay um now now imagine say we +have an + + align:start position:0% +have an + + + align:start position:0% +have an +inhome okay we'll do the same thing this + + align:start position:0% +inhome okay we'll do the same thing this + + + align:start position:0% +inhome okay we'll do the same thing this +is our uh probe beam we're going to come + + align:start position:0% +is our uh probe beam we're going to come + + + align:start position:0% +is our uh probe beam we're going to come +in with the narrow band pump and now + + align:start position:0% +in with the narrow band pump and now + + + align:start position:0% +in with the narrow band pump and now +what happens is we'll sort of bleach a + + align:start position:0% +what happens is we'll sort of bleach a + + + align:start position:0% +what happens is we'll sort of bleach a +hole into this + + align:start position:0% +hole into this + + + align:start position:0% +hole into this +line we're looking specifically at the + + align:start position:0% +line we're looking specifically at the + + + align:start position:0% +line we're looking specifically at the +case of an inhomogeneous Lune so now the + + align:start position:0% +case of an inhomogeneous Lune so now the + + + align:start position:0% +case of an inhomogeneous Lune so now the +change in intensity actually looks quite + + align:start position:0% +change in intensity actually looks quite + + + align:start position:0% +change in intensity actually looks quite +narrow along the prob and this also is + + align:start position:0% +narrow along the prob and this also is + + + align:start position:0% +narrow along the prob and this also is +one slice through a two dimensional + + align:start position:0% + + + + align:start position:0% + +surface if we look along the diagonal + + align:start position:0% +surface if we look along the diagonal + + + align:start position:0% +surface if we look along the diagonal +axis this uh this is the slice we took + + align:start position:0% +axis this uh this is the slice we took + + + align:start position:0% +axis this uh this is the slice we took +and it's really quite narrow now if you + + align:start position:0% +and it's really quite narrow now if you + + + align:start position:0% +and it's really quite narrow now if you +map out the whole surface you imagine + + align:start position:0% +map out the whole surface you imagine + + + align:start position:0% +map out the whole surface you imagine +seeing something that looks it's + + align:start position:0% +seeing something that looks it's + + + align:start position:0% +seeing something that looks it's +diagonally elongated like + + align:start position:0% +diagonally elongated like + + + align:start position:0% +diagonally elongated like +this okay I'm drawing just sort of + + align:start position:0% +this okay I'm drawing just sort of + + + align:start position:0% +this okay I'm drawing just sort of +Contours for what you might expect to + + align:start position:0% +Contours for what you might expect to + + + align:start position:0% +Contours for what you might expect to +see um so what is this telling us + + align:start position:0% +see um so what is this telling us + + + align:start position:0% +see um so what is this telling us +well clearly you can see that I take a + + align:start position:0% +well clearly you can see that I take a + + + align:start position:0% +well clearly you can see that I take a +slice along this diagonal axis I'm + + align:start position:0% +slice along this diagonal axis I'm + + + align:start position:0% +slice along this diagonal axis I'm +really just going to be mapping + + align:start position:0% +really just going to be mapping + + + align:start position:0% +really just going to be mapping +out the large broad profile that I saw + + align:start position:0% +out the large broad profile that I saw + + + align:start position:0% +out the large broad profile that I saw +in the absorption + + align:start position:0% +in the absorption + + + align:start position:0% +in the absorption +spect but um this whole burning + + align:start position:0% +spect but um this whole burning + + + align:start position:0% +spect but um this whole burning +experiment is clearly doing some sort of + + align:start position:0% +experiment is clearly doing some sort of + + + align:start position:0% +experiment is clearly doing some sort of +a line narrowing and in fact if you look + + align:start position:0% +a line narrowing and in fact if you look + + + align:start position:0% +a line narrowing and in fact if you look +at a little bit more carefully you can + + align:start position:0% +at a little bit more carefully you can + + + align:start position:0% +at a little bit more carefully you can +convince yourself that slice along this + + align:start position:0% +convince yourself that slice along this + + + align:start position:0% +convince yourself that slice along this +anti- diagonal but that actually gives + + align:start position:0% +anti- diagonal but that actually gives + + + align:start position:0% +anti- diagonal but that actually gives +you the homogeneous + + align:start position:0% +you the homogeneous + + + align:start position:0% +you the homogeneous +line so the idea is this is sort of the + + align:start position:0% +line so the idea is this is sort of the + + + align:start position:0% +line so the idea is this is sort of the +idea of a line shape that a line shape + + align:start position:0% +idea of a line shape that a line shape + + + align:start position:0% +idea of a line shape that a line shape +and analyzing a line shape can give you + + align:start position:0% +and analyzing a line shape can give you + + + align:start position:0% +and analyzing a line shape can give you +some sort of an information about how + + align:start position:0% +some sort of an information about how + + + align:start position:0% +some sort of an information about how +the ensembles meet + + align:start position:0% +the ensembles meet + + + align:start position:0% +the ensembles meet +up + + align:start position:0% +up + + + align:start position:0% +up +and and this is sort of much more than + + align:start position:0% +and and this is sort of much more than + + + align:start position:0% +and and this is sort of much more than +just doing say a photon Ono experiment + + align:start position:0% +just doing say a photon Ono experiment + + + align:start position:0% +just doing say a photon Ono experiment +which gives you an average measurement + + align:start position:0% +which gives you an average measurement + + + align:start position:0% +which gives you an average measurement +you can imagine that this line shape is + + align:start position:0% +you can imagine that this line shape is + + + align:start position:0% +you can imagine that this line shape is +composed of slightly different + + align:start position:0% +composed of slightly different + + + align:start position:0% +composed of slightly different +environments and it vary with frequency + + align:start position:0% +environments and it vary with frequency + + + align:start position:0% +environments and it vary with frequency +and that would show up as you know + + align:start position:0% +and that would show up as you know + + + align:start position:0% +and that would show up as you know +subtle details what this line shape + + align:start position:0% +subtle details what this line shape + + + align:start position:0% +subtle details what this line shape +looks + + align:start position:0% +looks + + + align:start position:0% +looks +like so there's a a lot in then + + align:start position:0% +like so there's a a lot in then + + + align:start position:0% +like so there's a a lot in then +analyzing those + + align:start position:0% + + + + align:start position:0% + +Contour so that that's um that's sort of + + align:start position:0% +Contour so that that's um that's sort of + + + align:start position:0% +Contour so that that's um that's sort of +the motivation for doing uh 2D + + align:start position:0% +the motivation for doing uh 2D + + + align:start position:0% +the motivation for doing uh 2D +these sorts of + + align:start position:0% + + + + align:start position:0% + +problems + + align:start position:0% +problems + + + align:start position:0% +problems +um okay + + align:start position:0% +um okay + + + align:start position:0% +um okay +so what + + align:start position:0% + + + + align:start position:0% + +um for the moment what I'd like to talk + + align:start position:0% +um for the moment what I'd like to talk + + + align:start position:0% +um for the moment what I'd like to talk +a little bit about is is this case here + + align:start position:0% +a little bit about is is this case here + + + align:start position:0% +a little bit about is is this case here +couple + + align:start position:0% +couple + + + align:start position:0% +couple +systems um because that that's one of + + align:start position:0% +systems um because that that's one of + + + align:start position:0% +systems um because that that's one of +the big uh reasons to do yeah actually + + align:start position:0% +the big uh reasons to do yeah actually + + + align:start position:0% +the big uh reasons to do yeah actually +there is one further example I didn't + + align:start position:0% +there is one further example I didn't + + + align:start position:0% +there is one further example I didn't +think about before but + + align:start position:0% +think about before but + + + align:start position:0% +think about before but +um you can also use this to tell you + + align:start position:0% +um you can also use this to tell you + + + align:start position:0% +um you can also use this to tell you +about reaction kinetics right you can + + align:start position:0% +about reaction kinetics right you can + + + align:start position:0% +about reaction kinetics right you can +imagine that uh you can pump if you have + + align:start position:0% +imagine that uh you can pump if you have + + + align:start position:0% +imagine that uh you can pump if you have +a sort of a chemical equilibrium you can + + align:start position:0% +a sort of a chemical equilibrium you can + + + align:start position:0% +a sort of a chemical equilibrium you can +pump one and probe the other and then + + align:start position:0% +pump one and probe the other and then + + + align:start position:0% +pump one and probe the other and then +time the time rate of change of Heats in + + align:start position:0% +time the time rate of change of Heats in + + + align:start position:0% +time the time rate of change of Heats in +that Sur tell you + + align:start position:0% +that Sur tell you + + + align:start position:0% +that Sur tell you +about but you know once you once you + + align:start position:0% +about but you know once you once you + + + align:start position:0% +about but you know once you once you +think about all the ways and people use + + align:start position:0% +think about all the ways and people use + + + align:start position:0% +think about all the ways and people use +a pump probe experiment that have been + + align:start position:0% +a pump probe experiment that have been + + + align:start position:0% +a pump probe experiment that have been +done for + + align:start position:0% +done for + + + align:start position:0% +done for +decades um you can see that there + + align:start position:0% +decades um you can see that there + + + align:start position:0% +decades um you can see that there +there's a mapping of the two + + align:start position:0% +there's a mapping of the two + + + align:start position:0% +there's a mapping of the two +dimensionals okay + + align:start position:0% +dimensionals okay + + + align:start position:0% +dimensionals okay +anyway um so one of the big applications + + align:start position:0% +anyway um so one of the big applications + + + align:start position:0% +anyway um so one of the big applications +is to understand uh molecular couplings + + align:start position:0% +is to understand uh molecular couplings + + + align:start position:0% +is to understand uh molecular couplings +and + + align:start position:0% +and + + + align:start position:0% +and +interactions right it's trying + + align:start position:0% +interactions right it's trying + + + align:start position:0% +interactions right it's trying +to boil down you know the essence of + + align:start position:0% +to boil down you know the essence of + + + align:start position:0% +to boil down you know the essence of +what's Happening molecularly that gives + + align:start position:0% +what's Happening molecularly that gives + + + align:start position:0% +what's Happening molecularly that gives +rise to a particular spectr and perhaps + + align:start position:0% +rise to a particular spectr and perhaps + + + align:start position:0% +rise to a particular spectr and perhaps +even trying to do things like invert a + + align:start position:0% +even trying to do things like invert a + + + align:start position:0% +even trying to do things like invert a +structure from + + align:start position:0% +structure from + + + align:start position:0% +structure from +it and so to start with that I just + + align:start position:0% +it and so to start with that I just + + + align:start position:0% +it and so to start with that I just +wanted + + align:start position:0% + + + + align:start position:0% + +as I've said + + align:start position:0% +as I've said + + + align:start position:0% +as I've said +before spectroscopy modeling is all one + + align:start position:0% +before spectroscopy modeling is all one + + + align:start position:0% +before spectroscopy modeling is all one +and the same we can't separate the two + + align:start position:0% +and the same we can't separate the two + + + align:start position:0% +and the same we can't separate the two +and so you know in terms of trying to + + align:start position:0% +and so you know in terms of trying to + + + align:start position:0% +and so you know in terms of trying to +describe what gives rise to cross PS in + + align:start position:0% +describe what gives rise to cross PS in + + + align:start position:0% +describe what gives rise to cross PS in +that reflect molecular interactions in + + align:start position:0% +that reflect molecular interactions in + + + align:start position:0% +that reflect molecular interactions in +the Spectra you really have to think + + align:start position:0% +the Spectra you really have to think + + + align:start position:0% +the Spectra you really have to think +about it in terms of a hamiltonian that + + align:start position:0% +about it in terms of a hamiltonian that + + + align:start position:0% +about it in terms of a hamiltonian that +includes these sorts of comps so I just + + align:start position:0% +includes these sorts of comps so I just + + + align:start position:0% +includes these sorts of comps so I just +wanted to write down some of the popular + + align:start position:0% +wanted to write down some of the popular + + + align:start position:0% +wanted to write down some of the popular +ones + + align:start position:0% +ones + + + align:start position:0% +ones +which you will see everywhere and in one + + align:start position:0% +which you will see everywhere and in one + + + align:start position:0% +which you will see everywhere and in one +form or another these are all the same + + align:start position:0% +form or another these are all the same + + + align:start position:0% +form or another these are all the same +thing with very subtle tweaks + + align:start position:0% +thing with very subtle tweaks + + + align:start position:0% +thing with very subtle tweaks +um for people that look at electronic + + align:start position:0% +um for people that look at electronic + + + align:start position:0% +um for people that look at electronic +couplings um in molecular systems it's + + align:start position:0% +couplings um in molecular systems it's + + + align:start position:0% +couplings um in molecular systems it's +called a Frankle aeton panel + + align:start position:0% + + + + align:start position:0% + +T sometimes uh it's known as a couple + + align:start position:0% +T sometimes uh it's known as a couple + + + align:start position:0% +T sometimes uh it's known as a couple +three Lev + + align:start position:0% + + + + align:start position:0% + +system for people + + align:start position:0% +system for people + + + align:start position:0% +system for people +doing vibrational work + + align:start position:0% +doing vibrational work + + + align:start position:0% +doing vibrational work +um might talk about couple + + align:start position:0% + + + + align:start position:0% + +oscillators and all you know in in + + align:start position:0% +oscillators and all you know in in + + + align:start position:0% +oscillators and all you know in in +essence what you're trying to do derive + + align:start position:0% +essence what you're trying to do derive + + + align:start position:0% +essence what you're trying to do derive +is the minimum hamiltonian that + + align:start position:0% +is the minimum hamiltonian that + + + align:start position:0% +is the minimum hamiltonian that +describes the interaction between two + + align:start position:0% +describes the interaction between two + + + align:start position:0% +describes the interaction between two +molecular + + align:start position:0% +molecular + + + align:start position:0% +molecular +States so um these uh at the simplest + + align:start position:0% +States so um these uh at the simplest + + + align:start position:0% +States so um these uh at the simplest +level these can boil this down to a 2x2 + + align:start position:0% +level these can boil this down to a 2x2 + + + align:start position:0% +level these can boil this down to a 2x2 +Hamilton Quantum States and in a coup + + align:start position:0% +Hamilton Quantum States and in a coup + + + align:start position:0% +Hamilton Quantum States and in a coup +but um so the basic idea behind all of + + align:start position:0% +but um so the basic idea behind all of + + + align:start position:0% +but um so the basic idea behind all of +these is that you know you imagine that + + align:start position:0% +these is that you know you imagine that + + + align:start position:0% +these is that you know you imagine that +I've got + + align:start position:0% +I've got + + + align:start position:0% +I've got +um two different Quantum states that may + + align:start position:0% +um two different Quantum states that may + + + align:start position:0% +um two different Quantum states that may +be + + align:start position:0% +be + + + align:start position:0% +be +on and uh that I'm going to introduce an + + align:start position:0% +on and uh that I'm going to introduce an + + + align:start position:0% +on and uh that I'm going to introduce an +interaction between these two um so of + + align:start position:0% +interaction between these two um so of + + + align:start position:0% +interaction between these two um so of +coupling these two states together with + + align:start position:0% +coupling these two states together with + + + align:start position:0% +coupling these two states together with +an interaction be we know that that sort + + align:start position:0% +an interaction be we know that that sort + + + align:start position:0% +an interaction be we know that that sort +of creates a common ground state and a + + align:start position:0% +of creates a common ground state and a + + + align:start position:0% +of creates a common ground state and a +split + + align:start position:0% +split + + + align:start position:0% +split +now the I if this was um call + + align:start position:0% +now the I if this was um call + + + align:start position:0% +now the I if this was um call +it and um but that this leads to a set + + align:start position:0% +it and um but that this leads to a set + + + align:start position:0% +it and um but that this leads to a set +of iding States let's say I mean in 574 + + align:start position:0% +of iding States let's say I mean in 574 + + + align:start position:0% +of iding States let's say I mean in 574 +we called them plus and minus but I + + align:start position:0% +we called them plus and minus but I + + + align:start position:0% +we called them plus and minus but I +think I'll call them a they call this + + align:start position:0% +think I'll call them a they call this + + + align:start position:0% +think I'll call them a they call this +one a b + + align:start position:0% + + + + align:start position:0% + +c and now these are I states of the + + align:start position:0% +c and now these are I states of the + + + align:start position:0% +c and now these are I states of the +material Anon we've been writing down so + + align:start position:0% +material Anon we've been writing down so + + + align:start position:0% +material Anon we've been writing down so +far and these now would be the states + + align:start position:0% +far and these now would be the states + + + align:start position:0% +far and these now would be the states +that one would think about creating + + align:start position:0% +that one would think about creating + + + align:start position:0% +that one would think about creating +resonances with + + align:start position:0% +resonances with + + + align:start position:0% +resonances with +in the the hamiltonian we've been + + align:start position:0% +in the the hamiltonian we've been + + + align:start position:0% +in the the hamiltonian we've been +describing the finding diagrams and the + + align:start position:0% +describing the finding diagrams and the + + + align:start position:0% +describing the finding diagrams and the +lad diagrams we've been + + align:start position:0% + + + + align:start position:0% + +describing so in in any case usually the + + align:start position:0% +describing so in in any case usually the + + + align:start position:0% +describing so in in any case usually the +information you want is back here so all + + align:start position:0% +information you want is back here so all + + + align:start position:0% +information you want is back here so all +of this is constructed in this local or + + align:start position:0% +of this is constructed in this local or + + + align:start position:0% +of this is constructed in this local or +site molecular + + align:start position:0% +site molecular + + + align:start position:0% +site molecular +basis so this Frankle xon amilon well + + align:start position:0% +basis so this Frankle xon amilon well + + + align:start position:0% +basis so this Frankle xon amilon well +let me just start with something that + + align:start position:0% +let me just start with something that + + + align:start position:0% +let me just start with something that +look familiar like a couple do you + + align:start position:0% +look familiar like a couple do you + + + align:start position:0% +look familiar like a couple do you +imagine two + + align:start position:0% +imagine two + + + align:start position:0% +imagine two +vibrations something + + align:start position:0% + + + + align:start position:0% + +like okay there's one VI one vibration + + align:start position:0% +like okay there's one VI one vibration + + + align:start position:0% +like okay there's one VI one vibration +and there's + + align:start position:0% + + + + align:start position:0% + +another was too now you have to couple + + align:start position:0% +another was too now you have to couple + + + align:start position:0% +another was too now you have to couple +them together in some and that involves + + align:start position:0% +them together in some and that involves + + + align:start position:0% +them together in some and that involves +in some way a coordinate or the moment + + align:start position:0% +in some way a coordinate or the moment + + + align:start position:0% +in some way a coordinate or the moment +of of the um these two oscillators so at + + align:start position:0% +of of the um these two oscillators so at + + + align:start position:0% +of of the um these two oscillators so at +the simplest level you might imagine um + + align:start position:0% +the simplest level you might imagine um + + + align:start position:0% +the simplest level you might imagine um +a linear compx it's called + + align:start position:0% +a linear compx it's called + + + align:start position:0% +a linear compx it's called +V or some more complicated combination + + align:start position:0% +V or some more complicated combination + + + align:start position:0% +V or some more complicated combination +those + + align:start position:0% +those + + + align:start position:0% +those +things um the frankal exaton anorm and + + align:start position:0% +things um the frankal exaton anorm and + + + align:start position:0% +things um the frankal exaton anorm and +it's usually Written In terms of raising + + align:start position:0% +it's usually Written In terms of raising + + + align:start position:0% +it's usually Written In terms of raising +and lowering operators in the + + align:start position:0% +and lowering operators in the + + + align:start position:0% +and lowering operators in the +electronics stes and by the way this + + align:start position:0% + + + + align:start position:0% + +is it might be + + align:start position:0% + + + + align:start position:0% + +um two diagonal terms and a cent + + align:start position:0% + + + + align:start position:0% + +I just want you to realize that all that + + align:start position:0% +I just want you to realize that all that + + + align:start position:0% +I just want you to realize that all that +is is shorthand for the 2x two Matrix + + align:start position:0% +is is shorthand for the 2x two Matrix + + + align:start position:0% +is is shorthand for the 2x two Matrix +that we know and + + align:start position:0% + + + + align:start position:0% + +love now just so the thing I want you to + + align:start position:0% +love now just so the thing I want you to + + + align:start position:0% +love now just so the thing I want you to +see is that uh these are really + + align:start position:0% +see is that uh these are really + + + align:start position:0% +see is that uh these are really +functionally the same hamiltoni right if + + align:start position:0% +functionally the same hamiltoni right if + + + align:start position:0% +functionally the same hamiltoni right if +you go now express your operational + + align:start position:0% +you go now express your operational + + + align:start position:0% +you go now express your operational +states of raising and lowering operators + + align:start position:0% +states of raising and lowering operators + + + align:start position:0% +states of raising and lowering operators +and just sort of take the leading + + align:start position:0% +and just sort of take the leading + + + align:start position:0% +and just sort of take the leading +harmonic term in these + + align:start position:0% + + + + align:start position:0% + +vibrations and this term here is going + + align:start position:0% +vibrations and this term here is going + + + align:start position:0% +vibrations and this term here is going +to have all sorts of um cross cross term + + align:start position:0% +to have all sorts of um cross cross term + + + align:start position:0% +to have all sorts of um cross cross term +and interactions right some of which + + align:start position:0% +and interactions right some of which + + + align:start position:0% +and interactions right some of which +will take the form wrot up + + align:start position:0% + + + + align:start position:0% + +there and extra + + align:start position:0% + + + + align:start position:0% + +Stu so what are these things telling you + + align:start position:0% +Stu so what are these things telling you + + + align:start position:0% +Stu so what are these things telling you +you're saying I've got two two + + align:start position:0% +you're saying I've got two two + + + align:start position:0% +you're saying I've got two two +vibrations two electronic States there's + + align:start position:0% +vibrations two electronic States there's + + + align:start position:0% +vibrations two electronic States there's +a coupling and that coupling um leads to + + align:start position:0% +a coupling and that coupling um leads to + + + align:start position:0% +a coupling and that coupling um leads to +will lead to in talking in this + + align:start position:0% +will lead to in talking in this + + + align:start position:0% +will lead to in talking in this +molecular base it's going to lead to + + align:start position:0% +molecular base it's going to lead to + + + align:start position:0% +molecular base it's going to lead to +energy being transferred from one state + + align:start position:0% +energy being transferred from one state + + + align:start position:0% +energy being transferred from one state +to another in an igen State + + align:start position:0% +to another in an igen State + + + align:start position:0% +to another in an igen State +picture translate + + align:start position:0% + + + + align:start position:0% + +this this uh creates a you know a new + + align:start position:0% +this this uh creates a you know a new + + + align:start position:0% +this this uh creates a you know a new +set of split I + + align:start position:0% + + + + align:start position:0% + +States okay so there is + + align:start position:0% +States okay so there is + + + align:start position:0% +States okay so there is +a now for the purposes of 2D + + align:start position:0% +a now for the purposes of 2D + + + align:start position:0% +a now for the purposes of 2D +spectroscopy we have to worry about a + + align:start position:0% +spectroscopy we have to worry about a + + + align:start position:0% +spectroscopy we have to worry about a +little bit extra um and that is you + + align:start position:0% +little bit extra um and that is you + + + align:start position:0% +little bit extra um and that is you +know + + align:start position:0% +know + + + align:start position:0% +know +for electronic systems + + align:start position:0% + + + + align:start position:0% + +we have to worry about the fact that + + align:start position:0% +we have to worry about the fact that + + + align:start position:0% +we have to worry about the fact that +there may be a in the IG State Pi there + + align:start position:0% +there may be a in the IG State Pi there + + + align:start position:0% +there may be a in the IG State Pi there +is a common ground state and then there + + align:start position:0% +is a common ground state and then there + + + align:start position:0% +is a common ground state and then there +are two um sly excited States also known + + align:start position:0% +are two um sly excited States also known + + + align:start position:0% +are two um sly excited States also known +as the one exiton States and we can call + + align:start position:0% +as the one exiton States and we can call + + + align:start position:0% +as the one exiton States and we can call +those plus or minus but for for my + + align:start position:0% +those plus or minus but for for my + + + align:start position:0% +those plus or minus but for for my +purposes I'd like to call them + + align:start position:0% +purposes I'd like to call them + + + align:start position:0% +purposes I'd like to call them +use my vibrational + + align:start position:0% +use my vibrational + + + align:start position:0% +use my vibrational +language it's yeah no that's not quite + + align:start position:0% +language it's yeah no that's not quite + + + align:start position:0% +language it's yeah no that's not quite +right basically I have um two possible + + align:start position:0% +right basically I have um two possible + + + align:start position:0% +right basically I have um two possible +States and I can put one Quantum of + + align:start position:0% +States and I can put one Quantum of + + + align:start position:0% +States and I can put one Quantum of +exitation into one State or the other we + + align:start position:0% +exitation into one State or the other we + + + align:start position:0% +exitation into one State or the other we +have to recognize there's also the + + align:start position:0% +have to recognize there's also the + + + align:start position:0% +have to recognize there's also the +possibility when you start talking about + + align:start position:0% +possibility when you start talking about + + + align:start position:0% +possibility when you start talking about +multiple interactions that there's a two + + align:start position:0% +multiple interactions that there's a two + + + align:start position:0% +multiple interactions that there's a two +exiton state where you've got one + + align:start position:0% +exiton state where you've got one + + + align:start position:0% +exiton state where you've got one +exitation um in each state + + align:start position:0% +exitation um in each state + + + align:start position:0% +exitation um in each state +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um we in a coupled electronic system + + align:start position:0% +um we in a coupled electronic system + + + align:start position:0% +um we in a coupled electronic system +we're really four levels you have to + + align:start position:0% +we're really four levels you have to + + + align:start position:0% +we're really four levels you have to +worry + + align:start position:0% + + + + align:start position:0% + +about um in a vibrational system it's + + align:start position:0% +about um in a vibrational system it's + + + align:start position:0% +about um in a vibrational system it's +basically the same except that you know + + align:start position:0% +basically the same except that you know + + + align:start position:0% +basically the same except that you know +with um bons you can uh unlike the + + align:start position:0% +with um bons you can uh unlike the + + + align:start position:0% +with um bons you can uh unlike the +firion you can put multiple excitations + + align:start position:0% +firion you can put multiple excitations + + + align:start position:0% +firion you can put multiple excitations +into the same vibration so there's an + + align:start position:0% +into the same vibration so there's an + + + align:start position:0% +into the same vibration so there's an +additional + + align:start position:0% +additional + + + align:start position:0% +additional +process you think of the I of a coupled + + align:start position:0% +process you think of the I of a coupled + + + align:start position:0% +process you think of the I of a coupled +vibration system not only do you have + + align:start position:0% +vibration system not only do you have + + + align:start position:0% +vibration system not only do you have +the ground + + align:start position:0% +the ground + + + align:start position:0% +the ground +state the U singly excited ion States + + align:start position:0% +state the U singly excited ion States + + + align:start position:0% +state the U singly excited ion States +but you also + + align:start position:0% +but you also + + + align:start position:0% +but you also +have three + + align:start position:0% + + + + align:start position:0% + +states two Quantum in either of the hi + + align:start position:0% +states two Quantum in either of the hi + + + align:start position:0% +states two Quantum in either of the hi +States and also you know what we like to + + align:start position:0% +States and also you know what we like to + + + align:start position:0% +States and also you know what we like to +call the combination it's where youve + + align:start position:0% +call the combination it's where youve + + + align:start position:0% +call the combination it's where youve +got one in each + + align:start position:0% +got one in each + + + align:start position:0% +got one in each +and so it's these four level and six + + align:start position:0% +and so it's these four level and six + + + align:start position:0% +and so it's these four level and six +level systems that um that are important + + align:start position:0% +level systems that um that are important + + + align:start position:0% +level systems that um that are important +to your sort of understanding the origin + + align:start position:0% +to your sort of understanding the origin + + + align:start position:0% +to your sort of understanding the origin +of all the peaks in the 2D + + align:start position:0% +of all the peaks in the 2D + + + align:start position:0% +of all the peaks in the 2D +spect + + align:start position:0% +spect + + + align:start position:0% +spect +so okay now when you go and uh apply the + + align:start position:0% +so okay now when you go and uh apply the + + + align:start position:0% +so okay now when you go and uh apply the +pump probe wave thinking that let's take + + align:start position:0% +pump probe wave thinking that let's take + + + align:start position:0% +pump probe wave thinking that let's take +this double resonance approach um and + + align:start position:0% +this double resonance approach um and + + + align:start position:0% +this double resonance approach um and +assume that the system always begins in + + align:start position:0% +assume that the system always begins in + + + align:start position:0% +assume that the system always begins in +this lowest lying State and you can of + + align:start position:0% +this lowest lying State and you can of + + + align:start position:0% +this lowest lying State and you can of +immediately map out a set of interaction + + align:start position:0% +immediately map out a set of interaction + + + align:start position:0% +immediately map out a set of interaction +processes that will give rise to a set + + align:start position:0% +processes that will give rise to a set + + + align:start position:0% +processes that will give rise to a set +of peaks in this spectrum so taking + + align:start position:0% +of peaks in this spectrum so taking + + + align:start position:0% +of peaks in this spectrum so taking +these + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +so so for the electronic case + + align:start position:0% +so so for the electronic case + + + align:start position:0% +so so for the electronic case +um you can see any initial interaction + + align:start position:0% +um you can see any initial interaction + + + align:start position:0% +um you can see any initial interaction +um with the electronic system is going + + align:start position:0% +um with the electronic system is going + + + align:start position:0% +um with the electronic system is going +to drive one of these one Quantum state + + align:start position:0% +to drive one of these one Quantum state + + + align:start position:0% +to drive one of these one Quantum state +so you um along the pump + + align:start position:0% +so you um along the pump + + + align:start position:0% +so you um along the pump +axis you know that you're only going to + + align:start position:0% +axis you know that you're only going to + + + align:start position:0% +axis you know that you're only going to +have resonances at let's see what should + + align:start position:0% +have resonances at let's see what should + + + align:start position:0% +have resonances at let's see what should +I + + align:start position:0% + + + + align:start position:0% + +call let's call this + + align:start position:0% +call let's call this + + + align:start position:0% +call let's call this +a + + align:start position:0% + + + + align:start position:0% + +c make a b make a + + align:start position:0% +c make a b make a + + + align:start position:0% +c make a b make a +CA you know that this is uh all of the + + align:start position:0% +CA you know that this is uh all of the + + + align:start position:0% +CA you know that this is uh all of the +pains that we observe we going going to + + align:start position:0% +pains that we observe we going going to + + + align:start position:0% +pains that we observe we going going to +have to be along these two directions + + align:start position:0% +have to be along these two directions + + + align:start position:0% +have to be along these two directions +and that in fact you know exactly what + + align:start position:0% +and that in fact you know exactly what + + + align:start position:0% +and that in fact you know exactly what +your linear spectrum is going to look + + align:start position:0% +your linear spectrum is going to look + + + align:start position:0% +your linear spectrum is going to look +like + + align:start position:0% +like + + + align:start position:0% +like +that two peaks that correspond to those + + align:start position:0% +that two peaks that correspond to those + + + align:start position:0% +that two peaks that correspond to those +ion stes the sly + + align:start position:0% +ion stes the sly + + + align:start position:0% +ion stes the sly +excited now you look at the possible + + align:start position:0% +excited now you look at the possible + + + align:start position:0% +excited now you look at the possible +permutations of how the system can + + align:start position:0% +permutations of how the system can + + + align:start position:0% +permutations of how the system can +evolve upwards and the + + align:start position:0% +evolve upwards and the + + + align:start position:0% +evolve upwards and the +possibilities involve well let's let me + + align:start position:0% +possibilities involve well let's let me + + + align:start position:0% +possibilities involve well let's let me +draw some + + align:start position:0% +draw some + + + align:start position:0% +draw some +possible what you'll find is that + + align:start position:0% +possible what you'll find is that + + + align:start position:0% +possible what you'll find is that +there's six Poss + + align:start position:0% + + + + align:start position:0% + +processes and uh actually I'm offsetting + + align:start position:0% +processes and uh actually I'm offsetting + + + align:start position:0% +processes and uh actually I'm offsetting +these two but uh the way I wrote the + + align:start position:0% +these two but uh the way I wrote the + + + align:start position:0% +these two but uh the way I wrote the +hamiltonian these are going to be + + align:start position:0% +hamiltonian these are going to be + + + align:start position:0% +hamiltonian these are going to be +sitting on top of one + + align:start position:0% +sitting on top of one + + + align:start position:0% +sitting on top of one +another um you'll see that these + + align:start position:0% +another um you'll see that these + + + align:start position:0% +another um you'll see that these +diagonal Peaks and one of these cross + + align:start position:0% +diagonal Peaks and one of these cross + + + align:start position:0% +diagonal Peaks and one of these cross +Peaks will all positive + + align:start position:0% +Peaks will all positive + + + align:start position:0% +Peaks will all positive +sign and the other cross a negative sign + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +is okay what gives rise to these things + + align:start position:0% +is okay what gives rise to these things + + + align:start position:0% +is okay what gives rise to these things +well first of all the diagonal stuff + + align:start position:0% +well first of all the diagonal stuff + + + align:start position:0% +well first of all the diagonal stuff +that should be obvious this is just all + + align:start position:0% +that should be obvious this is just all + + + align:start position:0% +that should be obvious this is just all +the pump probe stuff we've already + + align:start position:0% +the pump probe stuff we've already + + + align:start position:0% +the pump probe stuff we've already +written before that's a single + + align:start position:0% +written before that's a single + + + align:start position:0% +written before that's a single +transition where you drive the system + + align:start position:0% +transition where you drive the system + + + align:start position:0% +transition where you drive the system +upward create a population in that + + align:start position:0% +upward create a population in that + + + align:start position:0% +upward create a population in that +state um and + + align:start position:0% +state um and + + + align:start position:0% +state um and +then uh probe that + + align:start position:0% +then uh probe that + + + align:start position:0% +then uh probe that +state these cross p speaks you know uh + + align:start position:0% +state these cross p speaks you know uh + + + align:start position:0% +state these cross p speaks you know uh +to first order that is um the process I + + align:start position:0% +to first order that is um the process I + + + align:start position:0% +to first order that is um the process I +described up there cartoon ver that + + align:start position:0% +described up there cartoon ver that + + + align:start position:0% +described up there cartoon ver that +is + + align:start position:0% +is + + + align:start position:0% +is +driving population into one + + align:start position:0% +driving population into one + + + align:start position:0% +driving population into one +state and then probing the other + + align:start position:0% +state and then probing the other + + + align:start position:0% +state and then probing the other +state + + align:start position:0% +state + + + align:start position:0% +state +okay now this uh what's important is + + align:start position:0% +okay now this uh what's important is + + + align:start position:0% +okay now this uh what's important is +this other negative diagram and that + + align:start position:0% +this other negative diagram and that + + + align:start position:0% +this other negative diagram and that +that's where these two Exon or two + + align:start position:0% +that's where these two Exon or two + + + align:start position:0% +that's where these two Exon or two +quantum States come in those have + + align:start position:0% +quantum States come in those have + + + align:start position:0% +quantum States come in those have +opposite signs this going back to our + + align:start position:0% +opposite signs this going back to our + + + align:start position:0% +opposite signs this going back to our +how many times do you act on the bra + + align:start position:0% +how many times do you act on the bra + + + align:start position:0% +how many times do you act on the bra +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +process and they involve um processes in + + align:start position:0% +process and they involve um processes in + + + align:start position:0% +process and they involve um processes in +which you excite one vibration and then + + align:start position:0% +which you excite one vibration and then + + + align:start position:0% +which you excite one vibration and then +add in another + + align:start position:0% + + + + align:start position:0% + +quantum uh onto the other mode so let's + + align:start position:0% +quantum uh onto the other mode so let's + + + align:start position:0% +quantum uh onto the other mode so let's +say This + + align:start position:0% +say This + + + align:start position:0% +say This +Means A to B means we are putting let's + + align:start position:0% +Means A to B means we are putting let's + + + align:start position:0% +Means A to B means we are putting let's +start in the ground state put one + + align:start position:0% +start in the ground state put one + + + align:start position:0% +start in the ground state put one +Quantum into + + align:start position:0% +Quantum into + + + align:start position:0% +Quantum into +State B and then I'm going to add a + + align:start position:0% +State B and then I'm going to add a + + + align:start position:0% +State B and then I'm going to add a +Quantum in the state + + align:start position:0% +Quantum in the state + + + align:start position:0% +Quantum in the state +a and then I'll + + align:start position:0% +a and then I'll + + + align:start position:0% +a and then I'll +uh prob that state okay so now + + align:start position:0% +uh prob that state okay so now + + + align:start position:0% +uh prob that state okay so now +technically this + + align:start position:0% +technically this + + + align:start position:0% +technically this +transition comes out at a + + align:start position:0% +transition comes out at a + + + align:start position:0% +transition comes out at a +frequency call this guy + + align:start position:0% +frequency call this guy + + + align:start position:0% +frequency call this guy +D um we started at Omega VA and then + + align:start position:0% +D um we started at Omega VA and then + + + align:start position:0% +D um we started at Omega VA and then +we're going to observe the system at + + align:start position:0% +we're going to observe the system at + + + align:start position:0% +we're going to observe the system at +Omega + + align:start position:0% + + + + align:start position:0% + +DB + + align:start position:0% +DB + + + align:start position:0% +DB +so actually I'm really doing it wrong + + align:start position:0% +so actually I'm really doing it wrong + + + align:start position:0% +so actually I'm really doing it wrong +now this negative Peak is going to be at + + align:start position:0% +now this negative Peak is going to be at + + + align:start position:0% +now this negative Peak is going to be at +a slightly different + + align:start position:0% +a slightly different + + + align:start position:0% +a slightly different +frequency now in this one thing you'll + + align:start position:0% +frequency now in this one thing you'll + + + align:start position:0% +frequency now in this one thing you'll +notice is in this very commonly written + + align:start position:0% +notice is in this very commonly written + + + align:start position:0% +notice is in this very commonly written +hamiltonian in which you just have + + align:start position:0% +hamiltonian in which you just have + + + align:start position:0% +hamiltonian in which you just have +simple linear + + align:start position:0% +simple linear + + + align:start position:0% +simple linear +couplings simple AAG terms + + align:start position:0% +couplings simple AAG terms + + + align:start position:0% +couplings simple AAG terms +simple linear q1 Q2 types of terms and + + align:start position:0% +simple linear q1 Q2 types of terms and + + + align:start position:0% +simple linear q1 Q2 types of terms and +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +systems coincidentally it + + align:start position:0% +systems coincidentally it + + + align:start position:0% +systems coincidentally it +happens not coincidentally quite on + + align:start position:0% +happens not coincidentally quite on + + + align:start position:0% +happens not coincidentally quite on +purpose that um + + align:start position:0% +purpose that um + + + align:start position:0% +purpose that um +Omega VA + + align:start position:0% +Omega VA + + + align:start position:0% +Omega VA +a and Omega DC are + + align:start position:0% +a and Omega DC are + + + align:start position:0% +a and Omega DC are +identical not only that but um + + align:start position:0% +identical not only that but um + + + align:start position:0% +identical not only that but um +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +CA and Omega DB they're identical also + + align:start position:0% +CA and Omega DB they're identical also + + + align:start position:0% +CA and Omega DB they're identical also +and what that means is you're going to + + align:start position:0% +and what that means is you're going to + + + align:start position:0% +and what that means is you're going to +have two terms with opposite sign that + + align:start position:0% +have two terms with opposite sign that + + + align:start position:0% +have two terms with opposite sign that +show up right on top of each other + + align:start position:0% +show up right on top of each other + + + align:start position:0% +show up right on top of each other +disappears so for this kind of a simple + + align:start position:0% +disappears so for this kind of a simple + + + align:start position:0% +disappears so for this kind of a simple +system and that same goes for a coupled + + align:start position:0% +system and that same goes for a coupled + + + align:start position:0% +system and that same goes for a coupled +harmonic oscillator system um see these + + align:start position:0% +harmonic oscillator system um see these + + + align:start position:0% +harmonic oscillator system um see these +cross PS actually vanish and this is a + + align:start position:0% +cross PS actually vanish and this is a + + + align:start position:0% +cross PS actually vanish and this is a +manifestation of the fact that there is + + align:start position:0% +manifestation of the fact that there is + + + align:start position:0% +manifestation of the fact that there is +no nonlinear response from a harmonic + + align:start position:0% +no nonlinear response from a harmonic + + + align:start position:0% +no nonlinear response from a harmonic +system you need some sort of uh more + + align:start position:0% +system you need some sort of uh more + + + align:start position:0% +system you need some sort of uh more +complex coupling and harmonicity and + + align:start position:0% +complex coupling and harmonicity and + + + align:start position:0% +complex coupling and harmonicity and +harmonicity in a vibration system that's + + align:start position:0% +harmonicity in a vibration system that's + + + align:start position:0% +harmonicity in a vibration system that's +the word we use there or this may mean + + align:start position:0% +the word we use there or this may mean + + + align:start position:0% +the word we use there or this may mean +um other types of electron electron + + align:start position:0% +um other types of electron electron + + + align:start position:0% +um other types of electron electron +interactions to give you a measurable um + + align:start position:0% +interactions to give you a measurable um + + + align:start position:0% +interactions to give you a measurable um +type of inter uh coupling or interaction + + align:start position:0% +type of inter uh coupling or interaction + + + align:start position:0% +type of inter uh coupling or interaction +that one sees in a 2d Spectrum what do I + + align:start position:0% +that one sees in a 2d Spectrum what do I + + + align:start position:0% +that one sees in a 2d Spectrum what do I +mean by + + align:start position:0% +mean by + + + align:start position:0% +mean by +that what I mean is in a physical just + + align:start position:0% +that what I mean is in a physical just + + + align:start position:0% +that what I mean is in a physical just +sort of from a physical picture + + align:start position:0% +sort of from a physical picture + + + align:start position:0% +sort of from a physical picture +sense I need an effect where there is a + + align:start position:0% +sense I need an effect where there is a + + + align:start position:0% +sense I need an effect where there is a +difference where if I put one Quantum of + + align:start position:0% +difference where if I put one Quantum of + + + align:start position:0% +difference where if I put one Quantum of +exaltation into one state and then + + align:start position:0% +exaltation into one state and then + + + align:start position:0% +exaltation into one state and then +another quantum into the other state + + align:start position:0% +another quantum into the other state + + + align:start position:0% +another quantum into the other state +that that is not merely just the sum of + + align:start position:0% +that that is not merely just the sum of + + + align:start position:0% +that that is not merely just the sum of +the two energies the I need some + + align:start position:0% +the two energies the I need some + + + align:start position:0% +the two energies the I need some +physical effect where if I put energy + + align:start position:0% +physical effect where if I put energy + + + align:start position:0% +physical effect where if I put energy +into one state they communicate with + + align:start position:0% +into one state they communicate with + + + align:start position:0% +into one state they communicate with +each other and so by definition I will + + align:start position:0% +each other and so by definition I will + + + align:start position:0% +each other and so by definition I will +need to put a little less or a little + + align:start position:0% +need to put a little less or a little + + + align:start position:0% +need to put a little less or a little +more + + align:start position:0% +more + + + align:start position:0% +more +energy uh into the system for that + + align:start position:0% +energy uh into the system for that + + + align:start position:0% +energy uh into the system for that +second quum just because of the initial + + align:start position:0% +second quum just because of the initial + + + align:start position:0% +second quum just because of the initial +interaction uh and so uh how do you + + align:start position:0% +interaction uh and so uh how do you + + + align:start position:0% +interaction uh and so uh how do you +write those sorts of things in the case + + align:start position:0% +write those sorts of things in the case + + + align:start position:0% +write those sorts of things in the case +of um vibrational systems it comes about + + align:start position:0% +of um vibrational systems it comes about + + + align:start position:0% +of um vibrational systems it comes about +from anharmonicities it might be the + + align:start position:0% +from anharmonicities it might be the + + + align:start position:0% +from anharmonicities it might be the +higher order terms and the anharmonic + + align:start position:0% +higher order terms and the anharmonic + + + align:start position:0% +higher order terms and the anharmonic +potential it may be nonlinear + + align:start position:0% +potential it may be nonlinear + + + align:start position:0% +potential it may be nonlinear +couplings over in the case of the exaton + + align:start position:0% +couplings over in the case of the exaton + + + align:start position:0% +couplings over in the case of the exaton +hamiltonian we're saying things + + align:start position:0% + + + + align:start position:0% + +like imagine you have a coupling + + align:start position:0% +like imagine you have a coupling + + + align:start position:0% +like imagine you have a coupling +constant that goes as + + align:start position:0% + + + + align:start position:0% + +the ability to put an exitation into n + + align:start position:0% +the ability to put an exitation into n + + + align:start position:0% +the ability to put an exitation into n +depends on whether I have populated M + + align:start position:0% +depends on whether I have populated M + + + align:start position:0% +depends on whether I have populated M +there and the magnitude of that effect + + align:start position:0% +there and the magnitude of that effect + + + align:start position:0% +there and the magnitude of that effect +depends on data so you need um a term + + align:start position:0% +depends on data so you need um a term + + + align:start position:0% +depends on data so you need um a term +that goes higher order than just simple + + align:start position:0% +that goes higher order than just simple + + + align:start position:0% +that goes higher order than just simple +AA diagr types of terms what that leads + + align:start position:0% +AA diagr types of terms what that leads + + + align:start position:0% +AA diagr types of terms what that leads +to is a shift of this um exaton + + align:start position:0% +to is a shift of this um exaton + + + align:start position:0% +to is a shift of this um exaton +State um typically an harmonicity look + + align:start position:0% +State um typically an harmonicity look + + + align:start position:0% +State um typically an harmonicity look +in vibrational systems will shift down + + align:start position:0% +in vibrational systems will shift down + + + align:start position:0% +in vibrational systems will shift down +all of these levels in the electronic + + align:start position:0% +all of these levels in the electronic + + + align:start position:0% +all of these levels in the electronic +case you can imagine shifts both up and + + align:start position:0% +case you can imagine shifts both up and + + + align:start position:0% +case you can imagine shifts both up and +down and it really just depends on the + + align:start position:0% +down and it really just depends on the + + + align:start position:0% +down and it really just depends on the +electron electron interactions if you + + align:start position:0% +electron electron interactions if you + + + align:start position:0% +electron electron interactions if you +have positive or negative coupl see yeah + + align:start position:0% +have positive or negative coupl see yeah + + + align:start position:0% +have positive or negative coupl see yeah +right positive and negative couplings + + align:start position:0% +right positive and negative couplings + + + align:start position:0% +right positive and negative couplings +can take this up or down and that will + + align:start position:0% +can take this up or down and that will + + + align:start position:0% +can take this up or down and that will +dictate which way this peak + + align:start position:0% + + + + align:start position:0% + +shifts and then what we do is go sort of + + align:start position:0% +shifts and then what we do is go sort of + + + align:start position:0% +shifts and then what we do is go sort of +analyze the splittings between these + + align:start position:0% +analyze the splittings between these + + + align:start position:0% +analyze the splittings between these +cross Peaks and and that gives rise to + + align:start position:0% +cross Peaks and and that gives rise to + + + align:start position:0% +cross Peaks and and that gives rise to +sort of information about what the + + align:start position:0% +sort of information about what the + + + align:start position:0% +sort of information about what the +coupling + + align:start position:0% +coupling + + + align:start position:0% +coupling +is these will be related to electron + + align:start position:0% +is these will be related to electron + + + align:start position:0% +is these will be related to electron +electron equ okay so the vibrational + + align:start position:0% +electron equ okay so the vibrational + + + align:start position:0% +electron equ okay so the vibrational +system is exactly the same I mean at + + align:start position:0% +system is exactly the same I mean at + + + align:start position:0% +system is exactly the same I mean at +first level you're going to end up + + align:start position:0% +first level you're going to end up + + + align:start position:0% +first level you're going to end up +with you know two diagonal PS these are + + align:start position:0% +with you know two diagonal PS these are + + + align:start position:0% +with you know two diagonal PS these are +now going to have a doublet shape and + + align:start position:0% +now going to have a doublet shape and + + + align:start position:0% +now going to have a doublet shape and +that just reflects the fact that you + + align:start position:0% +that just reflects the fact that you + + + align:start position:0% +that just reflects the fact that you +have these two one States + + align:start position:0% +have these two one States + + + align:start position:0% +have these two one States +also and proc speaks between + + align:start position:0% + + + + align:start position:0% + +them and in this case it's similar but + + align:start position:0% +them and in this case it's similar but + + + align:start position:0% +them and in this case it's similar but +um the way I've written that hamiltonian + + align:start position:0% +um the way I've written that hamiltonian + + + align:start position:0% +um the way I've written that hamiltonian +over there splitting between these PES + + align:start position:0% +over there splitting between these PES + + + align:start position:0% +over there splitting between these PES +um in the case that you have two + + align:start position:0% +um in the case that you have two + + + align:start position:0% +um in the case that you have two +degenerate oscillators this is going to + + align:start position:0% +degenerate oscillators this is going to + + + align:start position:0% +degenerate oscillators this is going to +be twice the + + align:start position:0% +be twice the + + + align:start position:0% +be twice the +comp and that just reflects the fact + + align:start position:0% +comp and that just reflects the fact + + + align:start position:0% +comp and that just reflects the fact +that um the + + align:start position:0% +that um the + + + align:start position:0% +that um the +energy of the combination band in a + + align:start position:0% +energy of the combination band in a + + + align:start position:0% +energy of the combination band in a +coupled system is to L written it's + + align:start position:0% +coupled system is to L written it's + + + align:start position:0% +coupled system is to L written it's +Omega 1 it's the sum of the two energies + + align:start position:0% +Omega 1 it's the sum of the two energies + + + align:start position:0% +Omega 1 it's the sum of the two energies +minus twice coupling Between the + + align:start position:0% +minus twice coupling Between the + + + align:start position:0% +minus twice coupling Between the +States you had a question so would the + + align:start position:0% +States you had a question so would the + + + align:start position:0% +States you had a question so would the +same whether you have inter cpls you + + align:start position:0% + + + + align:start position:0% + +have + + align:start position:0% +have + + + align:start position:0% +have +so in so in this vibrational case as do + + align:start position:0% +so in so in this vibrational case as do + + + align:start position:0% +so in so in this vibrational case as do +it turns out if you just do a simple + + align:start position:0% +it turns out if you just do a simple + + + align:start position:0% +it turns out if you just do a simple +linear coupling between anharmonic + + align:start position:0% +linear coupling between anharmonic + + + align:start position:0% +linear coupling between anharmonic +oscillators you will um get + + align:start position:0% +oscillators you will um get + + + align:start position:0% +oscillators you will um get +anharmonically + + align:start position:0% + + + + align:start position:0% + +shifted what if you don't have just have + + align:start position:0% +shifted what if you don't have just have + + + align:start position:0% +shifted what if you don't have just have +two an no then you won't u i mean then + + align:start position:0% +two an no then you won't u i mean then + + + align:start position:0% +two an no then you won't u i mean then +you really have two independent + + align:start position:0% +you really have two independent + + + align:start position:0% +you really have two independent +oscillators you need something that you + + align:start position:0% +oscillators you need something that you + + + align:start position:0% +oscillators you need something that you +mean you need some sort of a term that + + align:start position:0% +mean you need some sort of a term that + + + align:start position:0% +mean you need some sort of a term that +laws the + + align:start position:0% +laws the + + + align:start position:0% +laws the +two you do need something in one + + align:start position:0% + + + + align:start position:0% + +coord and and what this is saying is + + align:start position:0% +coord and and what this is saying is + + + align:start position:0% +coord and and what this is saying is +that um for simple harmonic system are + + align:start position:0% +that um for simple harmonic system are + + + align:start position:0% +that um for simple harmonic system are +simple two Lev systems with the linear + + align:start position:0% +simple two Lev systems with the linear + + + align:start position:0% +simple two Lev systems with the linear +couplings and harmonic Behavior are sort + + align:start position:0% +couplings and harmonic Behavior are sort + + + align:start position:0% +couplings and harmonic Behavior are sort +of synonymous with one another and if + + align:start position:0% +of synonymous with one another and if + + + align:start position:0% +of synonymous with one another and if +you have linear cup cup LS and harmonic + + align:start position:0% +you have linear cup cup LS and harmonic + + + align:start position:0% +you have linear cup cup LS and harmonic +Behavior there is no nonlinear response + + align:start position:0% +Behavior there is no nonlinear response + + + align:start position:0% +Behavior there is no nonlinear response +when you really work + + align:start position:0% +when you really work + + + align:start position:0% +when you really work +through there you will always find terms + + align:start position:0% +through there you will always find terms + + + align:start position:0% +through there you will always find terms +that have opposite sign that destructive + + align:start position:0% +that have opposite sign that destructive + + + align:start position:0% +that have opposite sign that destructive +they interfere + + align:start position:0% +they interfere + + + align:start position:0% +they interfere +with other so but if you had diagonales + + align:start position:0% +with other so but if you had diagonales + + + align:start position:0% +with other so but if you had diagonales +would get her that frequency matching + + align:start position:0% +would get her that frequency matching + + + align:start position:0% +would get her that frequency matching +between the two qu of levels one one + + align:start position:0% +between the two qu of levels one one + + + align:start position:0% +between the two qu of levels one one +yeah exactly so that + + align:start position:0% +yeah exactly so that + + + align:start position:0% +yeah exactly so that +would that get rid of the cancellation + + align:start position:0% +would that get rid of the cancellation + + + align:start position:0% +would that get rid of the cancellation +between the cross yeah exactly so you + + align:start position:0% +between the cross yeah exactly so you + + + align:start position:0% +between the cross yeah exactly so you +can take anharmonic oscillators with + + align:start position:0% +can take anharmonic oscillators with + + + align:start position:0% +can take anharmonic oscillators with +linear + + align:start position:0% + + + + align:start position:0% + +coupling okay + + align:start position:0% +coupling okay + + + align:start position:0% +coupling okay +um what the why the pie on the diagonal + + align:start position:0% +um what the why the pie on the diagonal + + + align:start position:0% +um what the why the pie on the diagonal +have two loes again um so that that + + align:start position:0% +have two loes again um so that that + + + align:start position:0% +have two loes again um so that that +reflects the overtone we put two P into + + align:start position:0% +reflects the overtone we put two P into + + + align:start position:0% +reflects the overtone we put two P into +the same vition so this feet reflects + + align:start position:0% +the same vition so this feet reflects + + + align:start position:0% +the same vition so this feet reflects +the fact that you can go + + align:start position:0% +the fact that you can go + + + align:start position:0% +the fact that you can go +0 0 1 0 2 + + align:start position:0% + + + + align:start position:0% + +0 you can pump the fundamental + + align:start position:0% +0 you can pump the fundamental + + + align:start position:0% +0 you can pump the fundamental +transition and probe the overtone + + align:start position:0% +transition and probe the overtone + + + align:start position:0% +transition and probe the overtone +transition and that typically is + + align:start position:0% +transition and that typically is + + + align:start position:0% +transition and that typically is +anharmonically shifted by a little bit + + align:start position:0% +anharmonically shifted by a little bit + + + align:start position:0% +anharmonically shifted by a little bit +if it's a harmonic oscillator they're + + align:start position:0% +if it's a harmonic oscillator they're + + + align:start position:0% +if it's a harmonic oscillator they're +the same and that that's going to vanish + + align:start position:0% +the same and that that's going to vanish + + + align:start position:0% +the same and that that's going to vanish +so again for harmonic Behavior the + + align:start position:0% +so again for harmonic Behavior the + + + align:start position:0% +so again for harmonic Behavior the +nonlinear response management so another + + align:start position:0% +nonlinear response management so another + + + align:start position:0% +nonlinear response management so another +way of thinking about this which might + + align:start position:0% +way of thinking about this which might + + + align:start position:0% +way of thinking about this which might +be more useful is really just think of + + align:start position:0% +be more useful is really just think of + + + align:start position:0% +be more useful is really just think of +this as the sum of two very close Peaks + + align:start position:0% +this as the sum of two very close Peaks + + + align:start position:0% +this as the sum of two very close Peaks +and that you just are going to have Net + + align:start position:0% +and that you just are going to have Net + + + align:start position:0% +and that you just are going to have Net +One Peak whose + + align:start position:0% +One Peak whose + + + align:start position:0% +One Peak whose +amplitude is going to reflect the + + align:start position:0% +amplitude is going to reflect the + + + align:start position:0% +amplitude is going to reflect the +magnitude of the C and you've got two + + align:start position:0% +magnitude of the C and you've got two + + + align:start position:0% +magnitude of the C and you've got two +overlapping Peaks that are just moving a + + align:start position:0% +overlapping Peaks that are just moving a + + + align:start position:0% +overlapping Peaks that are just moving a +little bit you can show that the + + align:start position:0% +little bit you can show that the + + + align:start position:0% +little bit you can show that the +amplitude of that sum is going to scale + + align:start position:0% +amplitude of that sum is going to scale + + + align:start position:0% +amplitude of that sum is going to scale +with the + + align:start position:0% +with the + + + align:start position:0% +with the +comp in practice can you usually resolve + + align:start position:0% +comp in practice can you usually resolve + + + align:start position:0% +comp in practice can you usually resolve +them as two separate P so um C you know + + align:start position:0% +them as two separate P so um C you know + + + align:start position:0% +them as two separate P so um C you know +C there's many times that we see it um + + align:start position:0% +C there's many times that we see it um + + + align:start position:0% +C there's many times that we see it um +in the vibrational systems but you know + + align:start position:0% +in the vibrational systems but you know + + + align:start position:0% +in the vibrational systems but you know +if I kind of do a survey in my head of + + align:start position:0% +if I kind of do a survey in my head of + + + align:start position:0% +if I kind of do a survey in my head of +things I've seen i' see on average it's + + align:start position:0% +things I've seen i' see on average it's + + + align:start position:0% +things I've seen i' see on average it's +more like this that you're looking at + + align:start position:0% +more like this that you're looking at + + + align:start position:0% +more like this that you're looking at +interference + + align:start position:0% +interference + + + align:start position:0% +interference +effects that it's hard to distinguish + + align:start position:0% +effects that it's hard to distinguish + + + align:start position:0% +effects that it's hard to distinguish +discrete resonances but but certainly in + + align:start position:0% +discrete resonances but but certainly in + + + align:start position:0% +discrete resonances but but certainly in +strongly coupled systems there's many + + align:start position:0% +strongly coupled systems there's many + + + align:start position:0% +strongly coupled systems there's many +examples of + + align:start position:0% + + + + align:start position:0% + +this doesn't that get complicated though + + align:start position:0% +this doesn't that get complicated though + + + align:start position:0% +this doesn't that get complicated though +because your your di moments will change + + align:start position:0% + + + + align:start position:0% + +two right so it is true what I I haven't + + align:start position:0% +two right so it is true what I I haven't + + + align:start position:0% +two right so it is true what I I haven't +talked about you do have to worry about + + align:start position:0% +talked about you do have to worry about + + + align:start position:0% +talked about you do have to worry about +the selection rules um and so the way + + align:start position:0% +the selection rules um and so the way + + + align:start position:0% +the selection rules um and so the way +I've drawn this is using harmonic + + align:start position:0% +I've drawn this is using harmonic + + + align:start position:0% +I've drawn this is using harmonic +oscillator selection rules and in that + + align:start position:0% +oscillator selection rules and in that + + + align:start position:0% +oscillator selection rules and in that +case you're not you're going to allow + + align:start position:0% +case you're not you're going to allow + + + align:start position:0% +case you're not you're going to allow +transitions between the ground and + + align:start position:0% +transitions between the ground and + + + align:start position:0% +transitions between the ground and +either of the first excited States and + + align:start position:0% +either of the first excited States and + + + align:start position:0% +either of the first excited States and +then also between either of the first + + align:start position:0% +then also between either of the first + + + align:start position:0% +then also between either of the first +excited States and any of the upper Ling + + align:start position:0% +excited States and any of the upper Ling + + + align:start position:0% +excited States and any of the upper Ling +states that are single Quantum + + align:start position:0% +states that are single Quantum + + + align:start position:0% +states that are single Quantum +transitions di you know harmonic + + align:start position:0% +transitions di you know harmonic + + + align:start position:0% +transitions di you know harmonic +oscillator selection goes so in this + + align:start position:0% +oscillator selection goes so in this + + + align:start position:0% +oscillator selection goes so in this +case there's two in this case it's the + + align:start position:0% +case there's two in this case it's the + + + align:start position:0% +case there's two in this case it's the +same you can connect the one exitation + + align:start position:0% +same you can connect the one exitation + + + align:start position:0% +same you can connect the one exitation +states to the + + align:start position:0% +states to the + + + align:start position:0% +states to the +overtone um but the + + align:start position:0% +overtone um but the + + + align:start position:0% +overtone um but the +um I'm sorry to the combination band but + + align:start position:0% +um I'm sorry to the combination band but + + + align:start position:0% +um I'm sorry to the combination band but +the overtone states can only be + + align:start position:0% +the overtone states can only be + + + align:start position:0% +the overtone states can only be +connected to their + + align:start position:0% + + + + align:start position:0% + +ini there there are examples where you + + align:start position:0% +ini there there are examples where you + + + align:start position:0% +ini there there are examples where you +can start to pick out extra Peaks that + + align:start position:0% +can start to pick out extra Peaks that + + + align:start position:0% +can start to pick out extra Peaks that +arise from them harmonically this + + align:start position:0% +arise from them harmonically this + + + align:start position:0% +arise from them harmonically this +allowed + + align:start position:0% + + + + align:start position:0% + +Transitions okay any any questions on + + align:start position:0% +Transitions okay any any questions on + + + align:start position:0% +Transitions okay any any questions on +that on + + align:start position:0% +that on + + + align:start position:0% +that on +that okay um so I could uh get now into + + align:start position:0% +that okay um so I could uh get now into + + + align:start position:0% +that okay um so I could uh get now into +sort of the other example of you know of + + align:start position:0% +sort of the other example of you know of + + + align:start position:0% +sort of the other example of you know of +looking at line shapes but I mean I + + align:start position:0% +looking at line shapes but I mean I + + + align:start position:0% +looking at line shapes but I mean I +think it's better we just call it a day + + align:start position:0% +think it's better we just call it a day + + + align:start position:0% +think it's better we just call it a day +here \ No newline at end of file diff --git a/eG_aRPy1KVE.txt b/eG_aRPy1KVE.txt new file mode 100644 index 0000000000000000000000000000000000000000..3a534f81cfd118e917953c8a665fa2bfe159dd5e --- /dev/null +++ b/eG_aRPy1KVE.txt @@ -0,0 +1,14643 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right okay let's get uh + + align:start position:0% +ocw.mit.edu all right okay let's get uh + + + align:start position:0% +ocw.mit.edu all right okay let's get uh +started um so before I make an + + align:start position:0% +started um so before I make an + + + align:start position:0% +started um so before I make an +introduction let me just make a few uh + + align:start position:0% +introduction let me just make a few uh + + + align:start position:0% +introduction let me just make a few uh +announcement + + align:start position:0% +announcement + + + align:start position:0% +announcement +a few of you came to us asking about the + + align:start position:0% +a few of you came to us asking about the + + + align:start position:0% +a few of you came to us asking about the +the grading uh for the term and some + + align:start position:0% +the grading uh for the term and some + + + align:start position:0% +the grading uh for the term and some +youi the problem sets may be on the + + align:start position:0% +youi the problem sets may be on the + + + align:start position:0% +youi the problem sets may be on the +difficult side and uh some of you + + align:start position:0% +difficult side and uh some of you + + + align:start position:0% +difficult side and uh some of you +haven't done all of them and some of you + + align:start position:0% +haven't done all of them and some of you + + + align:start position:0% +haven't done all of them and some of you +done more so we just want to let you + + align:start position:0% +done more so we just want to let you + + + align:start position:0% +done more so we just want to let you +know that uh the most important thing uh + + align:start position:0% +know that uh the most important thing uh + + + align:start position:0% +know that uh the most important thing uh +to us in grading is really you know you + + align:start position:0% +to us in grading is really you know you + + + align:start position:0% +to us in grading is really you know you +show your effort in terms of learning + + align:start position:0% +show your effort in terms of learning + + + align:start position:0% +show your effort in terms of learning +and we purposely made the problem sets + + align:start position:0% +and we purposely made the problem sets + + + align:start position:0% +and we purposely made the problem sets +more difficult than the lecture so you + + align:start position:0% +more difficult than the lecture so you + + + align:start position:0% +more difficult than the lecture so you +can if you want to dig into uh deeper so + + align:start position:0% +can if you want to dig into uh deeper so + + + align:start position:0% +can if you want to dig into uh deeper so +you have the opportunity to learn more + + align:start position:0% +you have the opportunity to learn more + + + align:start position:0% +you have the opportunity to learn more +but by no means uh we expect you to + + align:start position:0% +but by no means uh we expect you to + + + align:start position:0% +but by no means uh we expect you to +finish or feel easy in solving all the + + align:start position:0% +finish or feel easy in solving all the + + + align:start position:0% +finish or feel easy in solving all the +problem um uh do the other the problem + + align:start position:0% +problem um uh do the other the problem + + + align:start position:0% +problem um uh do the other the problem +sets so I just want to put you at ease + + align:start position:0% +sets so I just want to put you at ease + + + align:start position:0% +sets so I just want to put you at ease +that uh if that's your concern that's + + align:start position:0% +that uh if that's your concern that's + + + align:start position:0% +that uh if that's your concern that's +definitely you don't need to worry about + + align:start position:0% +definitely you don't need to worry about + + + align:start position:0% +definitely you don't need to worry about +it and uh we will be um uh really just + + align:start position:0% +it and uh we will be um uh really just + + + align:start position:0% +it and uh we will be um uh really just +evaluating + + align:start position:0% +evaluating + + + align:start position:0% +evaluating +uh your effort and based on what we + + align:start position:0% +uh your effort and based on what we + + + align:start position:0% +uh your effort and based on what we +observed so far we actually believe + + align:start position:0% +observed so far we actually believe + + + align:start position:0% +observed so far we actually believe +every single one of you is doing quite + + align:start position:0% +every single one of you is doing quite + + + align:start position:0% +every single one of you is doing quite +well so you shouldn't uh worry about uh + + align:start position:0% +well so you shouldn't uh worry about uh + + + align:start position:0% +well so you shouldn't uh worry about uh +your performance at the class so + + align:start position:0% +your performance at the class so + + + align:start position:0% +your performance at the class so +continue to uh do a good job on your uh + + align:start position:0% +continue to uh do a good job on your uh + + + align:start position:0% +continue to uh do a good job on your uh +class participation and uh do some of + + align:start position:0% +class participation and uh do some of + + + align:start position:0% +class participation and uh do some of +the problem sets and then will you'll be + + align:start position:0% +the problem sets and then will you'll be + + + align:start position:0% +the problem sets and then will you'll be +in fine shape for your grade so that + + align:start position:0% +in fine shape for your grade so that + + + align:start position:0% +in fine shape for your grade so that +that's all of that so without any + + align:start position:0% +that's all of that so without any + + + align:start position:0% +that's all of that so without any +further delay let me uh introduce my + + align:start position:0% +further delay let me uh introduce my + + + align:start position:0% +further delay let me uh introduce my +colleague Dr Steven BL I'll be very + + align:start position:0% +colleague Dr Steven BL I'll be very + + + align:start position:0% +colleague Dr Steven BL I'll be very +brief and he's uh Steven is um doing two + + align:start position:0% +brief and he's uh Steven is um doing two + + + align:start position:0% +brief and he's uh Steven is um doing two +jobs at the same time he's um + + align:start position:0% +jobs at the same time he's um + + + align:start position:0% +jobs at the same time he's um +responsible for the all the public + + align:start position:0% +responsible for the all the public + + + align:start position:0% +responsible for the all the public +markets at the Harvard management uh as + + align:start position:0% +markets at the Harvard management uh as + + + align:start position:0% +markets at the Harvard management uh as +well as being a professor of practice at + + align:start position:0% +well as being a professor of practice at + + + align:start position:0% +well as being a professor of practice at +Harvard so with that I turn to Stephen + + align:start position:0% +Harvard so with that I turn to Stephen + + + align:start position:0% +Harvard so with that I turn to Stephen +okay well thank you Jake and thank you + + align:start position:0% +okay well thank you Jake and thank you + + + align:start position:0% +okay well thank you Jake and thank you +for having me to to speak this afternoon + + align:start position:0% +for having me to to speak this afternoon + + + align:start position:0% +for having me to to speak this afternoon +uh before I um before I begin I wanted + + align:start position:0% +uh before I um before I begin I wanted + + + align:start position:0% +uh before I um before I begin I wanted +to ask you a question um so I'm speaking + + align:start position:0% +to ask you a question um so I'm speaking + + + align:start position:0% +to ask you a question um so I'm speaking +actually at uh almost exactly the 20th + + align:start position:0% +actually at uh almost exactly the 20th + + + align:start position:0% +actually at uh almost exactly the 20th +anniversary is something very important + + align:start position:0% +anniversary is something very important + + + align:start position:0% +anniversary is something very important +so um on the 19th of October + + align:start position:0% +so um on the 19th of October + + + align:start position:0% +so um on the 19th of October +1993 which I guess might be the birthday + + align:start position:0% +1993 which I guess might be the birthday + + + align:start position:0% +1993 which I guess might be the birthday +of uh some of you but any almost exactly + + align:start position:0% +of uh some of you but any almost exactly + + + align:start position:0% +of uh some of you but any almost exactly +20 years + + align:start position:0% +20 years + + + align:start position:0% +20 years +ago uh + + align:start position:0% +ago uh + + + align:start position:0% +ago uh +Congress voted 264 to 159 I actually + + align:start position:0% +Congress voted 264 to 159 I actually + + + align:start position:0% +Congress voted 264 to 159 I actually +remember the count of the vote uh to do + + align:start position:0% +remember the count of the vote uh to do + + + align:start position:0% +remember the count of the vote uh to do +something so anybody uh like to guess + + align:start position:0% +something so anybody uh like to guess + + + align:start position:0% +something so anybody uh like to guess +what they voted to do on the 19th of + + align:start position:0% +what they voted to do on the 19th of + + + align:start position:0% +what they voted to do on the 19th of +October 1993 that might be tangentially + + align:start position:0% +October 1993 that might be tangentially + + + align:start position:0% +October 1993 that might be tangentially +relevant to uh Finance in quantitative + + align:start position:0% +relevant to uh Finance in quantitative + + + align:start position:0% +relevant to uh Finance in quantitative +Finance anyone here from HMC is not + + align:start position:0% +Finance anyone here from HMC is not + + + align:start position:0% +Finance anyone here from HMC is not +allowed to answer anybody any + + align:start position:0% +allowed to answer anybody any + + + align:start position:0% +allowed to answer anybody any +guesses any ideas at all coming into + + align:start position:0% +guesses any ideas at all coming into + + + align:start position:0% +guesses any ideas at all coming into +people's minds was it Le Bailey no + + align:start position:0% +people's minds was it Le Bailey no + + + align:start position:0% +people's minds was it Le Bailey no +these good good uh good guess but + + align:start position:0% +these good good uh good guess but + + + align:start position:0% +these good good uh good guess but +actually that is actually too related to + + align:start position:0% +actually that is actually too related to + + + align:start position:0% +actually that is actually too related to +finance actually this is actually um + + align:start position:0% +finance actually this is actually um + + + align:start position:0% +finance actually this is actually um +wasn't directly financially related so + + align:start position:0% +wasn't directly financially related so + + + align:start position:0% +wasn't directly financially related so +that was related the fut anybody else + + align:start position:0% +that was related the fut anybody else + + + align:start position:0% +that was related the fut anybody else +think + + align:start position:0% + + + + align:start position:0% + +about what does Congress usually + + align:start position:0% + + + + align:start position:0% + +do no no ideas + + align:start position:0% + + + + align:start position:0% + +whatsoever what do you think Congress + + align:start position:0% +whatsoever what do you think Congress + + + align:start position:0% +whatsoever what do you think Congress +did 20 years ago they voted to do + + align:start position:0% +did 20 years ago they voted to do + + + align:start position:0% +did 20 years ago they voted to do +something okay well what Congress do + + align:start position:0% +something okay well what Congress do + + + align:start position:0% +something okay well what Congress do +usually they cut money to something so + + align:start position:0% +usually they cut money to something so + + + align:start position:0% +usually they cut money to something so +they voted to cut financing to + + align:start position:0% +they voted to cut financing to + + + align:start position:0% +they voted to cut financing to +something what do they cut financing to + + align:start position:0% +something what do they cut financing to + + + align:start position:0% +something what do they cut financing to +anybody anybody + + align:start position:0% +anybody anybody + + + align:start position:0% +anybody anybody +guess I know this isn't business school + + align:start position:0% +guess I know this isn't business school + + + align:start position:0% +guess I know this isn't business school +in business school it'd be like right + + align:start position:0% +in business school it'd be like right + + + align:start position:0% +in business school it'd be like right +you're failed no past class + + align:start position:0% +you're failed no past class + + + align:start position:0% +you're failed no past class +participation you're failed you're got + + align:start position:0% +participation you're failed you're got + + + align:start position:0% +participation you're failed you're got +to say something in business school so I + + align:start position:0% +to say something in business school so I + + + align:start position:0% +to say something in business school so I +know it's not business school but anyway + + align:start position:0% +know it's not business school but anyway + + + align:start position:0% +know it's not business school but anyway +it's and I don't teach in business + + align:start position:0% +it's and I don't teach in business + + + align:start position:0% +it's and I don't teach in business +school either but this is actually these + + align:start position:0% +school either but this is actually these + + + align:start position:0% +school either but this is actually these +round desks make me think of business + + align:start position:0% +round desks make me think of business + + + align:start position:0% +round desks make me think of business +school and uh striding into the middle + + align:start position:0% +school and uh striding into the middle + + + align:start position:0% +school and uh striding into the middle +of the the room and saying okay come on + + align:start position:0% +of the the room and saying okay come on + + + align:start position:0% +of the the room and saying okay come on +fortunately you don't have names + + align:start position:0% +fortunately you don't have names + + + align:start position:0% +fortunately you don't have names +otherwise I'd pick on you no no + + align:start position:0% +otherwise I'd pick on you no no + + + align:start position:0% +otherwise I'd pick on you no no +guesses no guesses whatsoever this is + + align:start position:0% +guesses no guesses whatsoever this is + + + align:start position:0% +guesses no guesses whatsoever this is +I'm going to take this up the road to + + align:start position:0% +I'm going to take this up the road to + + + align:start position:0% +I'm going to take this up the road to +Harvard Square and say when I taught at + + align:start position:0% +Harvard Square and say when I taught at + + + align:start position:0% +Harvard Square and say when I taught at +MIT no one had any guesses for this + + align:start position:0% +MIT no one had any guesses for this + + + align:start position:0% +MIT no one had any guesses for this +question one guess actually the + + align:start position:0% +question one guess actually the + + + align:start position:0% +question one guess actually the +gentleman here what do they cancel + + align:start position:0% +gentleman here what do they cancel + + + align:start position:0% +gentleman here what do they cancel +cancel uh what did they cancel their + + align:start position:0% +cancel uh what did they cancel their + + + align:start position:0% +cancel uh what did they cancel their +financing for in 1993 + + align:start position:0% +financing for in 1993 + + + align:start position:0% +financing for in 1993 +so all right well let's say it was the + + align:start position:0% +so all right well let's say it was the + + + align:start position:0% +so all right well let's say it was the +Super conducting super + + align:start position:0% +Super conducting super + + + align:start position:0% +Super conducting super +collider uh underneath Texas just south + + align:start position:0% +collider uh underneath Texas just south + + + align:start position:0% +collider uh underneath Texas just south +of Dallas so um $2 billion had been + + align:start position:0% +of Dallas so um $2 billion had been + + + align:start position:0% +of Dallas so um $2 billion had been +spent on the super collider and the + + align:start position:0% +spent on the super collider and the + + + align:start position:0% +spent on the super collider and the +budget had expanded from I think six + + align:start position:0% +budget had expanded from I think six + + + align:start position:0% +budget had expanded from I think six +billion to 11 billion so they by + + align:start position:0% +billion to 11 billion so they by + + + align:start position:0% +billion to 11 billion so they by +canceling they had a $9 billion saving + + align:start position:0% +canceling they had a $9 billion saving + + + align:start position:0% +canceling they had a $9 billion saving +this was 20 years ago ex almost exactly + + align:start position:0% +this was 20 years ago ex almost exactly + + + align:start position:0% +this was 20 years ago ex almost exactly +um and as a result of that one result of + + align:start position:0% +um and as a result of that one result of + + + align:start position:0% +um and as a result of that one result of +that was of course the academic job + + align:start position:0% +that was of course the academic job + + + align:start position:0% +that was of course the academic job +market for + + align:start position:0% +market for + + + align:start position:0% +market for +physicists collapsed + + align:start position:0% +physicists collapsed + + + align:start position:0% +physicists collapsed +overnight and two of my roommates were + + align:start position:0% +overnight and two of my roommates were + + + align:start position:0% +overnight and two of my roommates were +theoretical physicists at Harvard and + + align:start position:0% +theoretical physicists at Harvard and + + + align:start position:0% +theoretical physicists at Harvard and +they basically realized their job + + align:start position:0% +they basically realized their job + + + align:start position:0% +they basically realized their job +prospects in Academia had vaporized + + align:start position:0% +prospects in Academia had vaporized + + + align:start position:0% +prospects in Academia had vaporized +instantaneously that day and both of + + align:start position:0% +instantaneously that day and both of + + + align:start position:0% +instantaneously that day and both of +them within six months had found jobs + + align:start position:0% +them within six months had found jobs + + + align:start position:0% +them within six months had found jobs +with Goldman Sachs in New + + align:start position:0% +with Goldman Sachs in New + + + align:start position:0% +with Goldman Sachs in New +York and they catalyzed they I mean they + + align:start position:0% +York and they catalyzed they I mean they + + + align:start position:0% +York and they catalyzed they I mean they +and the cohort I've call the super + + align:start position:0% +and the cohort I've call the super + + + align:start position:0% +and the cohort I've call the super +superc conducting super collider + + align:start position:0% +superc conducting super collider + + + align:start position:0% +superc conducting super collider +generation if you ever wondered why + + align:start position:0% +generation if you ever wondered why + + + align:start position:0% +generation if you ever wondered why +people like myself and like Jake who got + + align:start position:0% +people like myself and like Jake who got + + + align:start position:0% +people like myself and like Jake who got +phds in quantitative subjects around the + + align:start position:0% +phds in quantitative subjects around the + + + align:start position:0% +phds in quantitative subjects around the +turn of around 1992 1993 all ended up in + + align:start position:0% +turn of around 1992 1993 all ended up in + + + align:start position:0% +turn of around 1992 1993 all ended up in +a financial path part of it is due to + + align:start position:0% +a financial path part of it is due to + + + align:start position:0% +a financial path part of it is due to +Congress cancelling the super superc + + align:start position:0% +Congress cancelling the super superc + + + align:start position:0% +Congress cancelling the super superc +conducting super collider because this + + align:start position:0% +conducting super collider because this + + + align:start position:0% +conducting super collider because this +cohort catalyzed this growth in + + align:start position:0% +cohort catalyzed this growth in + + + align:start position:0% +cohort catalyzed this growth in +quantitative Finance so actually they + + align:start position:0% +quantitative Finance so actually they + + + align:start position:0% +quantitative Finance so actually they +created a field Financial engineering + + align:start position:0% +created a field Financial engineering + + + align:start position:0% +created a field Financial engineering +which you are all somewhat interested in + + align:start position:0% +which you are all somewhat interested in + + + align:start position:0% +which you are all somewhat interested in +by taking this class okay and they also + + align:start position:0% +by taking this class okay and they also + + + align:start position:0% +by taking this class okay and they also +created a career path quantitative + + align:start position:0% +created a career path quantitative + + + align:start position:0% +created a career path quantitative +analyst or Quant right which really did + + align:start position:0% +analyst or Quant right which really did + + + align:start position:0% +analyst or Quant right which really did +not exist before 1993 okay and that + + align:start position:0% +not exist before 1993 okay and that + + + align:start position:0% +not exist before 1993 okay and that +growth + + align:start position:0% +growth + + + align:start position:0% +growth +of mathematical Finance Financial + + align:start position:0% +of mathematical Finance Financial + + + align:start position:0% +of mathematical Finance Financial +engineering quantitative Finance however + + align:start position:0% +engineering quantitative Finance however + + + align:start position:0% +engineering quantitative Finance however +you want to look at it was basically + + align:start position:0% +you want to look at it was basically + + + align:start position:0% +you want to look at it was basically +exponential from 1993 up until actually + + align:start position:0% +exponential from 1993 up until actually + + + align:start position:0% +exponential from 1993 up until actually +2008 in the financial crisis exactly + + align:start position:0% +2008 in the financial crisis exactly + + + align:start position:0% +2008 in the financial crisis exactly +five years ago funly enough and uh since + + align:start position:0% +five years ago funly enough and uh since + + + align:start position:0% +five years ago funly enough and uh since +then it's been a little bit rockier so + + align:start position:0% +then it's been a little bit rockier so + + + align:start position:0% +then it's been a little bit rockier so +if you're actually interested in this + + align:start position:0% +if you're actually interested in this + + + align:start position:0% +if you're actually interested in this +aftermath of the physics funding what's + + align:start position:0% +aftermath of the physics funding what's + + + align:start position:0% +aftermath of the physics funding what's +interesting is the Large Hadron Collider + + align:start position:0% +interesting is the Large Hadron Collider + + + align:start position:0% +interesting is the Large Hadron Collider +which you might know was up and running + + align:start position:0% +which you might know was up and running + + + align:start position:0% +which you might know was up and running +in Geneva and we just found the higs + + align:start position:0% +in Geneva and we just found the higs + + + align:start position:0% +in Geneva and we just found the higs +boson has sort of reversed the trend + + align:start position:0% +boson has sort of reversed the trend + + + align:start position:0% +boson has sort of reversed the trend +somewhat so if there's there used to be + + align:start position:0% +somewhat so if there's there used to be + + + align:start position:0% +somewhat so if there's there used to be +a whole cohort of people going into + + align:start position:0% +a whole cohort of people going into + + + align:start position:0% +a whole cohort of people going into +Finance instead of physics now because + + align:start position:0% +Finance instead of physics now because + + + align:start position:0% +Finance instead of physics now because +Finance has this somewhat a orative + + align:start position:0% +Finance has this somewhat a orative + + + align:start position:0% +Finance has this somewhat a orative +nature to it you know people don't like + + align:start position:0% +nature to it you know people don't like + + + align:start position:0% +nature to it you know people don't like +Bankers generally and they kind of like + + align:start position:0% +Bankers generally and they kind of like + + + align:start position:0% +Bankers generally and they kind of like +physicist to find the higb on and get a + + align:start position:0% +physicist to find the higb on and get a + + + align:start position:0% +physicist to find the higb on and get a +Nobel Prize maybe we're getting a + + align:start position:0% +Nobel Prize maybe we're getting a + + + align:start position:0% +Nobel Prize maybe we're getting a +reversal but anyway we're still in + + align:start position:0% +reversal but anyway we're still in + + + align:start position:0% +reversal but anyway we're still in +finance I I've um as as Jake mentioned + + align:start position:0% +finance I I've um as as Jake mentioned + + + align:start position:0% +finance I I've um as as Jake mentioned +um well I didn't mention I I I was + + align:start position:0% +um well I didn't mention I I I was + + + align:start position:0% +um well I didn't mention I I I was +originally an academic so I was actually + + align:start position:0% +originally an academic so I was actually + + + align:start position:0% +originally an academic so I was actually +a mathematics uh faculty member in + + align:start position:0% +a mathematics uh faculty member in + + + align:start position:0% +a mathematics uh faculty member in +London when I got my PhD I got my PhD + + align:start position:0% +London when I got my PhD I got my PhD + + + align:start position:0% +London when I got my PhD I got my PhD +from Harvard and in 1993 I was an + + align:start position:0% +from Harvard and in 1993 I was an + + + align:start position:0% +from Harvard and in 1993 I was an +academic and then all my friends I saw + + align:start position:0% +academic and then all my friends I saw + + + align:start position:0% +academic and then all my friends I saw +them go to finance so I followed them uh + + align:start position:0% +them go to finance so I followed them uh + + + align:start position:0% +them go to finance so I followed them uh +spent a career in New York and then came + + align:start position:0% +spent a career in New York and then came + + + align:start position:0% +spent a career in New York and then came +back to Harvard in 2006 to run a part of + + align:start position:0% +back to Harvard in 2006 to run a part of + + + align:start position:0% +back to Harvard in 2006 to run a part of +the endowment and I've also started + + align:start position:0% +the endowment and I've also started + + + align:start position:0% +the endowment and I've also started +teaching so um just as a plug uh for + + align:start position:0% +teaching so um just as a plug uh for + + + align:start position:0% +teaching so um just as a plug uh for +those of you interested in mathematical + + align:start position:0% +those of you interested in mathematical + + + align:start position:0% +those of you interested in mathematical +finance and applications of mathematical + + align:start position:0% +finance and applications of mathematical + + + align:start position:0% +finance and applications of mathematical +Finance I teach a course at at Harvard + + align:start position:0% +Finance I teach a course at at Harvard + + + align:start position:0% +Finance I teach a course at at Harvard +it's an upper level undergraduate course + + align:start position:0% +it's an upper level undergraduate course + + + align:start position:0% +it's an upper level undergraduate course +called applied quantitative Finance + + align:start position:0% +called applied quantitative Finance + + + align:start position:0% +called applied quantitative Finance +which of course you can cross-register + + align:start position:0% +which of course you can cross-register + + + align:start position:0% +which of course you can cross-register +for um and today is also the one week + + align:start position:0% +for um and today is also the one week + + + align:start position:0% +for um and today is also the one week +anniversary of the publication of my + + align:start position:0% +anniversary of the publication of my + + + align:start position:0% +anniversary of the publication of my +book so um if you're interested in what + + align:start position:0% +book so um if you're interested in what + + + align:start position:0% +book so um if you're interested in what +my course is about you can just buy my + + align:start position:0% +my course is about you can just buy my + + + align:start position:0% +my course is about you can just buy my +book it's only 30 bucks so it's and I'll + + align:start position:0% +book it's only 30 bucks so it's and I'll + + + align:start position:0% +book it's only 30 bucks so it's and I'll +sign it first first edition first + + align:start position:0% +sign it first first edition first + + + align:start position:0% +sign it first first edition first +printing first impression book + + align:start position:0% +printing first impression book + + + align:start position:0% +printing first impression book +introduction to quantative Finance um + + align:start position:0% +introduction to quantative Finance um + + + align:start position:0% +introduction to quantative Finance um +and that is that's what that's what the + + align:start position:0% +and that is that's what that's what the + + + align:start position:0% +and that is that's what that's what the +course it's quite distilled when this + + align:start position:0% +course it's quite distilled when this + + + align:start position:0% +course it's quite distilled when this +book came out I thought that's really + + align:start position:0% +book came out I thought that's really + + + align:start position:0% +book came out I thought that's really +thin this is like three years of my work + + align:start position:0% +thin this is like three years of my work + + + align:start position:0% +thin this is like three years of my work +of my life's work it's come out it's + + align:start position:0% +of my life's work it's come out it's + + + align:start position:0% +of my life's work it's come out it's +very thin but I like to think it's like + + align:start position:0% +very thin but I like to think it's like + + + align:start position:0% +very thin but I like to think it's like +whiskey it's very it's well well + + align:start position:0% +whiskey it's very it's well well + + + align:start position:0% +whiskey it's very it's well well +distilled and highly potent and you have + + align:start position:0% +distilled and highly potent and you have + + + align:start position:0% +distilled and highly potent and you have +to sip it and take it take it bit by bit + + align:start position:0% +to sip it and take it take it bit by bit + + + align:start position:0% +to sip it and take it take it bit by bit +anyway that is that is the book of my my + + align:start position:0% +anyway that is that is the book of my my + + + align:start position:0% +anyway that is that is the book of my my +class and um the the Genesis of the + + align:start position:0% +class and um the the Genesis of the + + + align:start position:0% +class and um the the Genesis of the +class um was really that when I'd been + + align:start position:0% +class um was really that when I'd been + + + align:start position:0% +class um was really that when I'd been +on Wall Street and I was a colleague of + + align:start position:0% +on Wall Street and I was a colleague of + + + align:start position:0% +on Wall Street and I was a colleague of +Jake morg Stanley uh in this rapidly + + align:start position:0% +Jake morg Stanley uh in this rapidly + + + align:start position:0% +Jake morg Stanley uh in this rapidly +growing + + align:start position:0% +growing + + + align:start position:0% +growing +quantitative Finance field uh we + + align:start position:0% +quantitative Finance field uh we + + + align:start position:0% +quantitative Finance field uh we +encountered on the trading desk in the + + align:start position:0% +encountered on the trading desk in the + + + align:start position:0% +encountered on the trading desk in the +late 1990s in the early + + align:start position:0% +late 1990s in the early + + + align:start position:0% +late 1990s in the early +2000s uh problems from real the real + + align:start position:0% +2000s uh problems from real the real + + + align:start position:0% +2000s uh problems from real the real +economy things that we had to trade we + + align:start position:0% +economy things that we had to trade we + + + align:start position:0% +economy things that we had to trade we +were things that were coming to us on + + align:start position:0% +were things that were coming to us on + + + align:start position:0% +were things that were coming to us on +the trading desk that required + + align:start position:0% +the trading desk that required + + + align:start position:0% +the trading desk that required +um subtle understanding of the + + align:start position:0% +um subtle understanding of the + + + align:start position:0% +um subtle understanding of the +underlying Theory so that + + align:start position:0% +underlying Theory so that + + + align:start position:0% +underlying Theory so that +we in essence we built theoretical + + align:start position:0% +we in essence we built theoretical + + + align:start position:0% +we in essence we built theoretical +framework to solve the problems that + + align:start position:0% +framework to solve the problems that + + + align:start position:0% +framework to solve the problems that +were given to us by the financial + + align:start position:0% +were given to us by the financial + + + align:start position:0% +were given to us by the financial +markets so that period especially around + + align:start position:0% +markets so that period especially around + + + align:start position:0% +markets so that period especially around +the turn of uh 10 of the century um + + align:start position:0% +the turn of uh 10 of the century um + + + align:start position:0% +the turn of uh 10 of the century um +there's a big growth in derivatives + + align:start position:0% +there's a big growth in derivatives + + + align:start position:0% +there's a big growth in derivatives +markets which + + align:start position:0% +markets which + + + align:start position:0% +markets which +options Futures forwards Etc swaps um + + align:start position:0% +options Futures forwards Etc swaps um + + + align:start position:0% +options Futures forwards Etc swaps um +and we needed to build theoretical tools + + align:start position:0% +and we needed to build theoretical tools + + + align:start position:0% +and we needed to build theoretical tools +to tackle them and that's really what + + align:start position:0% +to tackle them and that's really what + + + align:start position:0% +to tackle them and that's really what +the the course was uh evolved out of to + + align:start position:0% +the the course was uh evolved out of to + + + align:start position:0% +the the course was uh evolved out of to +build the appropriate theoretical + + align:start position:0% +build the appropriate theoretical + + + align:start position:0% +build the appropriate theoretical +framework motivated by the problems we + + align:start position:0% +framework motivated by the problems we + + + align:start position:0% +framework motivated by the problems we +encountered um why I enthus about the + + align:start position:0% +encountered um why I enthus about the + + + align:start position:0% +encountered um why I enthus about the +subject um and I really like teaching + + align:start position:0% +subject um and I really like teaching + + + align:start position:0% +subject um and I really like teaching +the subject is that there is a an + + align:start position:0% +the subject is that there is a an + + + align:start position:0% +the subject is that there is a an +impression that quantative Finance is a + + align:start position:0% +impression that quantative Finance is a + + + align:start position:0% +impression that quantative Finance is a +very Arcane and + + align:start position:0% +very Arcane and + + + align:start position:0% +very Arcane and +contrived subject just a whole bunch of + + align:start position:0% +contrived subject just a whole bunch of + + + align:start position:0% +contrived subject just a whole bunch of +phds on Wall Street coming up with crazy + + align:start position:0% +phds on Wall Street coming up with crazy + + + align:start position:0% +phds on Wall Street coming up with crazy +ideas and they need complicated + + align:start position:0% +ideas and they need complicated + + + align:start position:0% +ideas and they need complicated +mathematics it's just complicated for + + align:start position:0% +mathematics it's just complicated for + + + align:start position:0% +mathematics it's just complicated for +the sake of complexity and the theory is + + align:start position:0% +the sake of complexity and the theory is + + + align:start position:0% +the sake of complexity and the theory is +just sort of a contrived Theory but in + + align:start position:0% +just sort of a contrived Theory but in + + + align:start position:0% +just sort of a contrived Theory but in +fact at the heart of Wall Street is that + + align:start position:0% +fact at the heart of Wall Street is that + + + align:start position:0% +fact at the heart of Wall Street is that +the real economy demands some of these + + align:start position:0% +the real economy demands some of these + + + align:start position:0% +the real economy demands some of these +products by supply and demand they're + + align:start position:0% +products by supply and demand they're + + + align:start position:0% +products by supply and demand they're +actual real participants in the + + align:start position:0% +actual real participants in the + + + align:start position:0% +actual real participants in the +financial markets who want to trade + + align:start position:0% +financial markets who want to trade + + + align:start position:0% +financial markets who want to trade +derivatives and therefore in order to + + align:start position:0% +derivatives and therefore in order to + + + align:start position:0% +derivatives and therefore in order to +understand them you need to develop a + + align:start position:0% +understand them you need to develop a + + + align:start position:0% +understand them you need to develop a +theory so it's actually driven by real + + align:start position:0% +theory so it's actually driven by real + + + align:start position:0% +theory so it's actually driven by real +examples that's one part the other part + + align:start position:0% +examples that's one part the other part + + + align:start position:0% +examples that's one part the other part +is that the theory that comes out of it + + align:start position:0% +is that the theory that comes out of it + + + align:start position:0% +is that the theory that comes out of it +and in particular the the approach I + + align:start position:0% +and in particular the the approach I + + + align:start position:0% +and in particular the the approach I +take here I think is just very elegant + + align:start position:0% +take here I think is just very elegant + + + align:start position:0% +take here I think is just very elegant +okay so there's some subtlety and + + align:start position:0% +okay so there's some subtlety and + + + align:start position:0% +okay so there's some subtlety and +elegance and Beauty to the underlying + + align:start position:0% +elegance and Beauty to the underlying + + + align:start position:0% +elegance and Beauty to the underlying +Theory you need to um that comes out of + + align:start position:0% +Theory you need to um that comes out of + + + align:start position:0% +Theory you need to um that comes out of +addressing real problems this course in + + align:start position:0% +addressing real problems this course in + + + align:start position:0% +addressing real problems this course in +the way that I I teach Finance um is + + align:start position:0% +the way that I I teach Finance um is + + + align:start position:0% +the way that I I teach Finance um is +very probability Centric you probably + + align:start position:0% +very probability Centric you probably + + + align:start position:0% +very probability Centric you probably +realized from the lectures you've seen + + align:start position:0% +realized from the lectures you've seen + + + align:start position:0% +realized from the lectures you've seen +already in this class there are many + + align:start position:0% +already in this class there are many + + + align:start position:0% +already in this class there are many +different approaches many different + + align:start position:0% +different approaches many different + + + align:start position:0% +different approaches many different +methods that are used in finance + + align:start position:0% +methods that are used in finance + + + align:start position:0% +methods that are used in finance +stochastic calculus partial differential + + align:start position:0% +stochastic calculus partial differential + + + align:start position:0% +stochastic calculus partial differential +equations simulation and so on okay the + + align:start position:0% +equations simulation and so on okay the + + + align:start position:0% +equations simulation and so on okay the +classical derivation of black schs is + + align:start position:0% +classical derivation of black schs is + + + align:start position:0% +classical derivation of black schs is +well but it's a solution of a + + align:start position:0% +well but it's a solution of a + + + align:start position:0% +well but it's a solution of a +pde okay that has appeal to people in + + align:start position:0% +pde okay that has appeal to people in + + + align:start position:0% +pde okay that has appeal to people in +fact this is why in some ways quantative + + align:start position:0% +fact this is why in some ways quantative + + + align:start position:0% +fact this is why in some ways quantative +Finance is a broad church because + + align:start position:0% +Finance is a broad church because + + + align:start position:0% +Finance is a broad church because +whether you're a physicist or a + + align:start position:0% +whether you're a physicist or a + + + align:start position:0% +whether you're a physicist or a +probabilist or a chemical engineer all + + align:start position:0% +probabilist or a chemical engineer all + + + align:start position:0% +probabilist or a chemical engineer all +the the techniques you learn can be + + align:start position:0% +the the techniques you learn can be + + + align:start position:0% +the the techniques you learn can be +applied you you know stochastic calculus + + align:start position:0% +applied you you know stochastic calculus + + + align:start position:0% +applied you you know stochastic calculus +or you know differential equations they + + align:start position:0% +or you know differential equations they + + + align:start position:0% +or you know differential equations they +can be applied but the path that I take + + align:start position:0% +can be applied but the path that I take + + + align:start position:0% +can be applied but the path that I take +in this class is very much through the + + align:start position:0% +in this class is very much through the + + + align:start position:0% +in this class is very much through the +probabilistic route okay which is my + + align:start position:0% +probabilistic route okay which is my + + + align:start position:0% +probabilistic route okay which is my +background as a as a probabilist as a as + + align:start position:0% +background as a as a probabilist as a as + + + align:start position:0% +background as a as a probabilist as a as +an academic or statistician as an + + align:start position:0% +an academic or statistician as an + + + align:start position:0% +an academic or statistician as an +academic and this is in particular I + + align:start position:0% +academic and this is in particular I + + + align:start position:0% +academic and this is in particular I +think a very elegant path to understand + + align:start position:0% +think a very elegant path to understand + + + align:start position:0% +think a very elegant path to understand +finance and the linkage between + + align:start position:0% +finance and the linkage between + + + align:start position:0% +finance and the linkage between +derivative products which might seem + + align:start position:0% +derivative products which might seem + + + align:start position:0% +derivative products which might seem +contrived and probability distributions + + align:start position:0% +contrived and probability distributions + + + align:start position:0% +contrived and probability distributions +which are sort of natural things for + + align:start position:0% +which are sort of natural things for + + + align:start position:0% +which are sort of natural things for +probabilists so this what I'm going to + + align:start position:0% +probabilists so this what I'm going to + + + align:start position:0% +probabilists so this what I'm going to +talk about today is really this link + + align:start position:0% +talk about today is really this link + + + align:start position:0% +talk about today is really this link +um which I call + + align:start position:0% +um which I call + + + align:start position:0% +um which I call +option + + align:start position:0% + + + + align:start position:0% + +probability + + align:start position:0% +probability + + + align:start position:0% +probability +Duality + + align:start position:0% +Duality + + + align:start position:0% +Duality +which in um in essence in the simplest + + align:start position:0% +which in um in essence in the simplest + + + align:start position:0% +which in um in essence in the simplest +form is just saying option prices is + + align:start position:0% +form is just saying option prices is + + + align:start position:0% +form is just saying option prices is +they're just probability distributions + + align:start position:0% +they're just probability distributions + + + align:start position:0% +they're just probability distributions +therefore these complicated derivatives + + align:start position:0% +therefore these complicated derivatives + + + align:start position:0% +therefore these complicated derivatives +that people talk about all these options + + align:start position:0% +that people talk about all these options + + + align:start position:0% +that people talk about all these options +these Financial Engineers these quants + + align:start position:0% +these Financial Engineers these quants + + + align:start position:0% +these Financial Engineers these quants +these Exotics we're really just talking + + align:start position:0% +these Exotics we're really just talking + + + align:start position:0% +these Exotics we're really just talking +about probability distributions and we + + align:start position:0% +about probability distributions and we + + + align:start position:0% +about probability distributions and we +can go between them option prices + + align:start position:0% +can go between them option prices + + + align:start position:0% +can go between them option prices +probability distributions and back and + + align:start position:0% +probability distributions and back and + + + align:start position:0% +probability distributions and back and +forth in a very elegant way and what I + + align:start position:0% +forth in a very elegant way and what I + + + align:start position:0% +forth in a very elegant way and what I +love about this subject in particular is + + align:start position:0% +love about this subject in particular is + + + align:start position:0% +love about this subject in particular is +that to get to that point where we see + + align:start position:0% +that to get to that point where we see + + + align:start position:0% +that to get to that point where we see +this Duality does not + + align:start position:0% +this Duality does not + + + align:start position:0% +this Duality does not +need a whole framework and + + align:start position:0% +need a whole framework and + + + align:start position:0% +need a whole framework and +infrastructure of comp complicated + + align:start position:0% +infrastructure of comp complicated + + + align:start position:0% +infrastructure of comp complicated +definitions or formula or option pricing + + align:start position:0% +definitions or formula or option pricing + + + align:start position:0% +definitions or formula or option pricing +formula or so on so that's what I'm + + align:start position:0% +formula or so on so that's what I'm + + + align:start position:0% +formula or so on so that's what I'm +going to try and do in this hour or so + + align:start position:0% +going to try and do in this hour or so + + + align:start position:0% +going to try and do in this hour or so +is introduce this concept of option + + align:start position:0% +is introduce this concept of option + + + align:start position:0% +is introduce this concept of option +price probability Duality and show how + + align:start position:0% +price probability Duality and show how + + + align:start position:0% +price probability Duality and show how +it's sort of a natural so there's a + + align:start position:0% +it's sort of a natural so there's a + + + align:start position:0% +it's sort of a natural so there's a +natural Duality it can be seen in a + + align:start position:0% +natural Duality it can be seen in a + + + align:start position:0% +natural Duality it can be seen in a +number of different ways okay so we're + + align:start position:0% +number of different ways okay so we're + + + align:start position:0% +number of different ways okay so we're +going to um need a few a few definitions + + align:start position:0% +going to um need a few a few definitions + + + align:start position:0% +going to um need a few a few definitions +that should be familiar uh to you we're + + align:start position:0% +that should be familiar uh to you we're + + + align:start position:0% +that should be familiar uh to you we're +going to Define three + + align:start position:0% +going to Define three + + + align:start position:0% +going to Define three +assets um I have a call + + align:start position:0% +assets um I have a call + + + align:start position:0% +assets um I have a call +option you know about out um a zero + + align:start position:0% +option you know about out um a zero + + + align:start position:0% +option you know about out um a zero +coupon + + align:start position:0% +coupon + + + align:start position:0% +coupon +Bond call a + + align:start position:0% +Bond call a + + + align:start position:0% +Bond call a +zcb this is the one thing I haven't + + align:start position:0% +zcb this is the one thing I haven't + + + align:start position:0% +zcb this is the one thing I haven't +become American is on I still call this + + align:start position:0% +become American is on I still call this + + + align:start position:0% +become American is on I still call this +Zed it's a other things I've become um + + align:start position:0% +Zed it's a other things I've become um + + + align:start position:0% +Zed it's a other things I've become um +and then a digital + + align:start position:0% + + + + align:start position:0% + +option okay all right so what are they + + align:start position:0% +option okay all right so what are they + + + align:start position:0% +option okay all right so what are they +well they're all going to be defined by + + align:start position:0% +well they're all going to be defined by + + + align:start position:0% +well they're all going to be defined by +their payout at maturity okay so we're + + align:start position:0% +their payout at maturity okay so we're + + + align:start position:0% +their payout at maturity okay so we're +going to have some maturity capital T um + + align:start position:0% +going to have some maturity capital T um + + + align:start position:0% +going to have some maturity capital T um +and some underlying asset s the stock + + align:start position:0% +and some underlying asset s the stock + + + align:start position:0% +and some underlying asset s the stock +with some price St okay so we know that + + align:start position:0% +with some price St okay so we know that + + + align:start position:0% +with some price St okay so we know that +the call option has payout at T so let's + + align:start position:0% +the call option has payout at T so let's + + + align:start position:0% +the call option has payout at T so let's +called pay out at + + align:start position:0% + + + + align:start position:0% + +T So T is some fixed time in the future + + align:start position:0% +T So T is some fixed time in the future + + + align:start position:0% +T So T is some fixed time in the future +we can we'll change it in future but + + align:start position:0% +we can we'll change it in future but + + + align:start position:0% +we can we'll change it in future but +some fixed time this is simply the max + + align:start position:0% +some fixed time this is simply the max + + + align:start position:0% +some fixed time this is simply the max +of St minus K and + + align:start position:0% +of St minus K and + + + align:start position:0% +of St minus K and +zero okay that's the call option um you + + align:start position:0% +zero okay that's the call option um you + + + align:start position:0% +zero okay that's the call option um you +know you can go + + align:start position:0% +know you can go + + + align:start position:0% +know you can go +through the right to buy etc etc but + + align:start position:0% +through the right to buy etc etc but + + + align:start position:0% +through the right to buy etc etc but +clearly it's just value at maturity is + + align:start position:0% +clearly it's just value at maturity is + + + align:start position:0% +clearly it's just value at maturity is +just the max of stus K and Z um the zero + + align:start position:0% +just the max of stus K and Z um the zero + + + align:start position:0% +just the max of stus K and Z um the zero +coupon bond with maturity T is just + + align:start position:0% +coupon bond with maturity T is just + + + align:start position:0% +coupon bond with maturity T is just +something that's worth one at time T so + + align:start position:0% +something that's worth one at time T so + + + align:start position:0% +something that's worth one at time T so +that's + + align:start position:0% +that's + + + align:start position:0% +that's +just pay one that's definition so you + + align:start position:0% +just pay one that's definition so you + + + align:start position:0% +just pay one that's definition so you +can think of these all as definitions um + + align:start position:0% +can think of these all as definitions um + + + align:start position:0% +can think of these all as definitions um +and then the digital option is just the + + align:start position:0% +and then the digital option is just the + + + align:start position:0% +and then the digital option is just the +indicator function of St being greater + + align:start position:0% +indicator function of St being greater + + + align:start position:0% +indicator function of St being greater +than + + align:start position:0% +than + + + align:start position:0% +than +K okay okay so here + + align:start position:0% +K okay okay so here + + + align:start position:0% +K okay okay so here +um T is the maturity K is the strike + + align:start position:0% +um T is the maturity K is the strike + + + align:start position:0% +um T is the maturity K is the strike +okay so T + + align:start position:0% + + + + align:start position:0% + +maturity okay is + + align:start position:0% +maturity okay is + + + align:start position:0% +maturity okay is +Strike okay and these are three three + + align:start position:0% +Strike okay and these are three three + + + align:start position:0% +Strike okay and these are three three +assets so this is in some sense the + + align:start position:0% +assets so this is in some sense the + + + align:start position:0% +assets so this is in some sense the +payout function okay all derivative + + align:start position:0% +payout function okay all derivative + + + align:start position:0% +payout function okay all derivative +products can be defined in terms of a + + align:start position:0% +products can be defined in terms of a + + + align:start position:0% +products can be defined in terms of a +function not all of them many derivative + + align:start position:0% +function not all of them many derivative + + + align:start position:0% +function not all of them many derivative +products can be defined just simp a + + align:start position:0% +products can be defined just simp a + + + align:start position:0% +products can be defined just simp a +function of St and here are three + + align:start position:0% +function of St and here are three + + + align:start position:0% +function of St and here are three +functions of St is the identity one okay + + align:start position:0% +functions of St is the identity one okay + + + align:start position:0% +functions of St is the identity one okay +and then I'm just going to um get + + align:start position:0% +and then I'm just going to um get + + + align:start position:0% +and then I'm just going to um get +notation for their price at T less than + + align:start position:0% +notation for their price at T less than + + + align:start position:0% +notation for their price at T less than +equal to T we can think about Little T + + align:start position:0% +equal to T we can think about Little T + + + align:start position:0% +equal to T we can think about Little T +as current time today or we can think of + + align:start position:0% +as current time today or we can think of + + + align:start position:0% +as current time today or we can think of +some future time between now and capital + + align:start position:0% +some future time between now and capital + + + align:start position:0% +some future time between now and capital +T um and I'm just going to introduce + + align:start position:0% +T um and I'm just going to introduce + + + align:start position:0% +T um and I'm just going to introduce +notation every different Finance book + + align:start position:0% +notation every different Finance book + + + align:start position:0% +notation every different Finance book +uses different notations so just um um + + align:start position:0% +uses different notations so just um um + + + align:start position:0% +uses different notations so just um um +let's just C for call Price with strike + + align:start position:0% +let's just C for call Price with strike + + + align:start position:0% +let's just C for call Price with strike +K uh at Little T with maturity Big T + + align:start position:0% +K uh at Little T with maturity Big T + + + align:start position:0% +K uh at Little T with maturity Big T +okay just that notation the zero coupon + + align:start position:0% +okay just that notation the zero coupon + + + align:start position:0% +okay just that notation the zero coupon +Bond the price at Little T we's call + + align:start position:0% +Bond the price at Little T we's call + + + align:start position:0% +Bond the price at Little T we's call +that Zed okay that's the price of little + + align:start position:0% +that Zed okay that's the price of little + + + align:start position:0% +that Zed okay that's the price of little +T and the digital we'll just call that + + align:start position:0% +T and the digital we'll just call that + + + align:start position:0% +T and the digital we'll just call that +D okay so this is what we're going to + + align:start position:0% +D okay so this is what we're going to + + + align:start position:0% +D okay so this is what we're going to +we're going to set this up U the not + + align:start position:0% +we're going to set this up U the not + + + align:start position:0% +we're going to set this up U the not +actually you could help you could have a + + align:start position:0% +actually you could help you could have a + + + align:start position:0% +actually you could help you could have a +whole lecture on why notation different + + align:start position:0% +whole lecture on why notation different + + + align:start position:0% +whole lecture on why notation different +notation K and capital T are actually + + align:start position:0% +notation K and capital T are actually + + + align:start position:0% +notation K and capital T are actually +embedded in the terms of the contract + + align:start position:0% +embedded in the terms of the contract + + + align:start position:0% +embedded in the terms of the contract +Little T is of my calendar time so you + + align:start position:0% +Little T is of my calendar time so you + + + align:start position:0% +Little T is of my calendar time so you +might think why don't you put K in + + align:start position:0% +might think why don't you put K in + + + align:start position:0% +might think why don't you put K in +capital D somewhere else well when you + + align:start position:0% +capital D somewhere else well when you + + + align:start position:0% +capital D somewhere else well when you +get actually to modeling derivatives you + + align:start position:0% +get actually to modeling derivatives you + + + align:start position:0% +get actually to modeling derivatives you +like to be moving both maturity and a + + align:start position:0% +like to be moving both maturity and a + + + align:start position:0% +like to be moving both maturity and a +forward time and calendar time that's + + align:start position:0% +forward time and calendar time that's + + + align:start position:0% +forward time and calendar time that's +why I just write it like that but + + align:start position:0% +why I just write it like that but + + + align:start position:0% +why I just write it like that but +there's no okay so C subk Little T Big T + + align:start position:0% +there's no okay so C subk Little T Big T + + + align:start position:0% +there's no okay so C subk Little T Big T +is the price at time Little T of a call + + align:start position:0% +is the price at time Little T of a call + + + align:start position:0% +is the price at time Little T of a call +with maturity capital T and strike K + + align:start position:0% +with maturity capital T and strike K + + + align:start position:0% +with maturity capital T and strike K +okay right black shs and other option + + align:start position:0% +okay right black shs and other option + + + align:start position:0% +okay right black shs and other option +pricing formula are all about + + align:start position:0% +pricing formula are all about + + + align:start position:0% +pricing formula are all about +determining + + align:start position:0% +determining + + + align:start position:0% +determining +this right for T less than T okay cuz + + align:start position:0% +this right for T less than T okay cuz + + + align:start position:0% +this right for T less than T okay cuz +clearly + + align:start position:0% +clearly + + + align:start position:0% +clearly +we know that the price at maturity is + + align:start position:0% +we know that the price at maturity is + + + align:start position:0% +we know that the price at maturity is +simply the payout right I mean that's + + align:start position:0% +simply the payout right I mean that's + + + align:start position:0% +simply the payout right I mean that's +again just the + + align:start position:0% +again just the + + + align:start position:0% +again just the +definition okay so that's that's trivial + + align:start position:0% +definition okay so that's that's trivial + + + align:start position:0% +definition okay so that's that's trivial +but we want to find out what the price + + align:start position:0% +but we want to find out what the price + + + align:start position:0% +but we want to find out what the price +is at Little T okay so that's a whole + + align:start position:0% +is at Little T okay so that's a whole + + + align:start position:0% +is at Little T okay so that's a whole +path of Finance black shs and other + + align:start position:0% +path of Finance black shs and other + + + align:start position:0% +path of Finance black shs and other +price option pricing methodology is + + align:start position:0% +price option pricing methodology is + + + align:start position:0% +price option pricing methodology is +working out this but we're actually + + align:start position:0% +working out this but we're actually + + + align:start position:0% +working out this but we're actually +going to go down a a different route + + align:start position:0% +going to go down a a different route + + + align:start position:0% +going to go down a a different route +okay right so what we're going to do we + + align:start position:0% +okay right so what we're going to do we + + + align:start position:0% +okay right so what we're going to do we +are going to construct a uh portfolio + + align:start position:0% +are going to construct a uh portfolio + + + align:start position:0% +are going to construct a uh portfolio +so we'll + + align:start position:0% + + + + align:start position:0% + +consider as a + + align:start position:0% +consider as a + + + align:start position:0% +consider as a +portfolio of what we're going to consist + + align:start position:0% +portfolio of what we're going to consist + + + align:start position:0% +portfolio of what we're going to consist +of two calls okay we're going to have + + align:start position:0% +of two calls okay we're going to have + + + align:start position:0% +of two calls okay we're going to have +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +calls with strike + + align:start position:0% +calls with strike + + + align:start position:0% +calls with strike +K okay so I just this the mount holding + + align:start position:0% +K okay so I just this the mount holding + + + align:start position:0% +K okay so I just this the mount holding +of and everything is going to be with + + align:start position:0% +of and everything is going to be with + + + align:start position:0% +of and everything is going to be with +maturity capital T So Lambda calls with + + align:start position:0% +maturity capital T So Lambda calls with + + + align:start position:0% +maturity capital T So Lambda calls with +strike K and maturity T and minus Lambda + + align:start position:0% +strike K and maturity T and minus Lambda + + + align:start position:0% +strike K and maturity T and minus Lambda +calls with + + align:start position:0% +calls with + + + align:start position:0% +calls with +strike k + 1 / + + align:start position:0% +strike k + 1 / + + + align:start position:0% +strike k + 1 / +Lambda okay we just consider that + + align:start position:0% +Lambda okay we just consider that + + + align:start position:0% +Lambda okay we just consider that +portfolio consists of two + + align:start position:0% +portfolio consists of two + + + align:start position:0% +portfolio consists of two +options all right well it's + + align:start position:0% + + + + align:start position:0% + +price at T well that's easy we just + + align:start position:0% +price at T well that's easy we just + + + align:start position:0% +price at T well that's easy we just +let's just write it in terms of what is + + align:start position:0% + + + + align:start position:0% + +Lambda times the price of the call with + + align:start position:0% +Lambda times the price of the call with + + + align:start position:0% +Lambda times the price of the call with +strike + + align:start position:0% +strike + + + align:start position:0% +strike +K minus Lambda + + align:start position:0% +K minus Lambda + + + align:start position:0% +K minus Lambda +call with + + align:start position:0% + + + + align:start position:0% + +strike k + one over Lambda okay it's + + align:start position:0% +strike k + one over Lambda okay it's + + + align:start position:0% +strike k + one over Lambda okay it's +just by definition that's its price at + + align:start position:0% +just by definition that's its price at + + + align:start position:0% +just by definition that's its price at +T okay well let's look at its + + align:start position:0% + + + + align:start position:0% + +payout time capital T + + align:start position:0% +payout time capital T + + + align:start position:0% +payout time capital T +graphically right okay so you know about + + align:start position:0% +graphically right okay so you know about + + + align:start position:0% +graphically right okay so you know about +call + + align:start position:0% +call + + + align:start position:0% +call +options right the payout function is + + align:start position:0% +options right the payout function is + + + align:start position:0% +options right the payout function is +just the hockey stick shape clearly + + align:start position:0% +just the hockey stick shape clearly + + + align:start position:0% +just the hockey stick shape clearly +that's confusing to people from the UK + + align:start position:0% +that's confusing to people from the UK + + + align:start position:0% +that's confusing to people from the UK +cu in in UK hockey means field hockey + + align:start position:0% +cu in in UK hockey means field hockey + + + align:start position:0% +cu in in UK hockey means field hockey +not ice hockey and of course hockey sck + + align:start position:0% +not ice hockey and of course hockey sck + + + align:start position:0% +not ice hockey and of course hockey sck +shape and field hockey looks very + + align:start position:0% +shape and field hockey looks very + + + align:start position:0% +shape and field hockey looks very +different anyway that's uh you + + align:start position:0% +different anyway that's uh you + + + align:start position:0% +different anyway that's uh you +understand what the payout of a call is + + align:start position:0% +understand what the payout of a call is + + + align:start position:0% +understand what the payout of a call is +clearly this payout function of a call + + align:start position:0% +clearly this payout function of a call + + + align:start position:0% +clearly this payout function of a call +looks like this + + align:start position:0% + + + + align:start position:0% + +right okay well putting + + align:start position:0% +right okay well putting + + + align:start position:0% +right okay well putting +this P of Lambda C strike K minus Lambda + + align:start position:0% +this P of Lambda C strike K minus Lambda + + + align:start position:0% +this P of Lambda C strike K minus Lambda +C strike K plus one over Lambda let's + + align:start position:0% +C strike K plus one over Lambda let's + + + align:start position:0% +C strike K plus one over Lambda let's +assume Lambda is positive for the time + + align:start position:0% +assume Lambda is positive for the time + + + align:start position:0% +assume Lambda is positive for the time +being what does it look like well it's + + align:start position:0% +being what does it look like well it's + + + align:start position:0% +being what does it look like well it's +zero below + + align:start position:0% + + + + align:start position:0% + +K it's flat above k + 1/ Lambda it has + + align:start position:0% +K it's flat above k + 1/ Lambda it has + + + align:start position:0% +K it's flat above k + 1/ Lambda it has +slope + + align:start position:0% +slope + + + align:start position:0% +slope +Lambda okay and has value one here + + align:start position:0% +Lambda okay and has value one here + + + align:start position:0% +Lambda okay and has value one here +okay right you should be able to see + + align:start position:0% +okay right you should be able to see + + + align:start position:0% +okay right you should be able to see +that just + + align:start position:0% +that just + + + align:start position:0% +that just +easily okay so that's the the pay this + + align:start position:0% +easily okay so that's the the pay this + + + align:start position:0% +easily okay so that's the the pay this +is called call spread just the spread + + align:start position:0% +is called call spread just the spread + + + align:start position:0% +is called call spread just the spread +between two calls okay it has this + + align:start position:0% +between two calls okay it has this + + + align:start position:0% +between two calls okay it has this +payout function Okay so natural thing to + + align:start position:0% +payout function Okay so natural thing to + + + align:start position:0% +payout function Okay so natural thing to +do + + align:start position:0% +do + + + align:start position:0% +do +here being a mathematics class let's + + align:start position:0% +here being a mathematics class let's + + + align:start position:0% +here being a mathematics class let's +take limits just let let Lambda tend to + + align:start position:0% +take limits just let let Lambda tend to + + + align:start position:0% +take limits just let let Lambda tend to +Infinity okay + + align:start position:0% + + + + align:start position:0% + +so okay well then this becomes the + + align:start position:0% +so okay well then this becomes the + + + align:start position:0% +so okay well then this becomes the +partial derivative of the core price + + align:start position:0% +partial derivative of the core price + + + align:start position:0% +partial derivative of the core price +with respect to K or the negative of it + + align:start position:0% +with respect to K or the negative of it + + + align:start position:0% +with respect to K or the negative of it +so this tends to + + align:start position:0% +so this tends to + + + align:start position:0% +so this tends to +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +minus + + align:start position:0% +minus + + + align:start position:0% +minus +okay right let's + + align:start position:0% +okay right let's + + + align:start position:0% +okay right let's +just okay so that's that and then this + + align:start position:0% +just okay so that's that and then this + + + align:start position:0% +just okay so that's that and then this +of course as Lambda goes to Infinity + + align:start position:0% +of course as Lambda goes to Infinity + + + align:start position:0% +of course as Lambda goes to Infinity +this stays at one so this tends + + align:start position:0% +this stays at one so this tends + + + align:start position:0% +this stays at one so this tends +to a payout + + align:start position:0% + + + + align:start position:0% + +function that looks like that + + align:start position:0% +function that looks like that + + + align:start position:0% +function that looks like that +okay right okay so this is easy calculus + + align:start position:0% +okay right okay so this is easy calculus + + + align:start position:0% +okay right okay so this is easy calculus +this is just by + + align:start position:0% +this is just by + + + align:start position:0% +this is just by +inspection right okay so this clearly is + + align:start position:0% +inspection right okay so this clearly is + + + align:start position:0% +inspection right okay so this clearly is +the payout of the digital + + align:start position:0% +the payout of the digital + + + align:start position:0% +the payout of the digital +right + + align:start position:0% + + + + align:start position:0% + +so right of the strictly digital call + + align:start position:0% +so right of the strictly digital call + + + align:start position:0% +so right of the strictly digital call +but that's called the digital digital + + align:start position:0% +but that's called the digital digital + + + align:start position:0% +but that's called the digital digital +option okay um just as a note here's + + align:start position:0% +option okay um just as a note here's + + + align:start position:0% +option okay um just as a note here's +just greater than you might think okay + + align:start position:0% +just greater than you might think okay + + + align:start position:0% +just greater than you might think okay +should does doesn't matter if this is + + align:start position:0% +should does doesn't matter if this is + + + align:start position:0% +should does doesn't matter if this is +greater than or equal to well in + + align:start position:0% +greater than or equal to well in + + + align:start position:0% +greater than or equal to well in +practice you know the chance of + + align:start position:0% +practice you know the chance of + + + align:start position:0% +practice you know the chance of +something equaling a number exactly you + + align:start position:0% +something equaling a number exactly you + + + align:start position:0% +something equaling a number exactly you +can is is zero I mean if it's a + + align:start position:0% +can is is zero I mean if it's a + + + align:start position:0% +can is is zero I mean if it's a +continuous distribution well in theory + + align:start position:0% +continuous distribution well in theory + + + align:start position:0% +continuous distribution well in theory +so I should say the chance of something + + align:start position:0% +so I should say the chance of something + + + align:start position:0% +so I should say the chance of something +actually nailing the strike actually + + align:start position:0% +actually nailing the strike actually + + + align:start position:0% +actually nailing the strike actually +being equal to K is zero so it doesn't + + align:start position:0% +being equal to K is zero so it doesn't + + + align:start position:0% +being equal to K is zero so it doesn't +really matter whether def Finance is + + align:start position:0% +really matter whether def Finance is + + + align:start position:0% +really matter whether def Finance is +greater than or greater than or equal to + + align:start position:0% +greater than or greater than or equal to + + + align:start position:0% +greater than or greater than or equal to +but in practice of course Finance is in + + align:start position:0% +but in practice of course Finance is in + + + align:start position:0% +but in practice of course Finance is in +discrete time because you don't quote + + align:start position:0% +discrete time because you don't quote + + + align:start position:0% +discrete time because you don't quote +things to a million decimal places right + + align:start position:0% +things to a million decimal places right + + + align:start position:0% +things to a million decimal places right +so certain assets actually which are + + align:start position:0% +so certain assets actually which are + + + align:start position:0% +so certain assets actually which are +quoted only in e or 16th or 302s or 64s + + align:start position:0% +quoted only in e or 16th or 302s or 64s + + + align:start position:0% +quoted only in e or 16th or 302s or 64s +this matters actually with you def find + + align:start position:0% +this matters actually with you def find + + + align:start position:0% +this matters actually with you def find +it's greater than greater or equal to + + align:start position:0% +it's greater than greater or equal to + + + align:start position:0% +it's greater than greater or equal to +but theoretically it doesn't make any + + align:start position:0% +but theoretically it doesn't make any + + + align:start position:0% +but theoretically it doesn't make any +difference Okay so we've got the call + + align:start position:0% +difference Okay so we've got the call + + + align:start position:0% +difference Okay so we've got the call +spread tending + + align:start position:0% +spread tending + + + align:start position:0% +spread tending +to the + + align:start position:0% +to the + + + align:start position:0% +to the +digital okay all right + + align:start position:0% +digital okay all right + + + align:start position:0% +digital okay all right +so this tends to um so the limit of this + + align:start position:0% +so this tends to um so the limit of this + + + align:start position:0% +so this tends to um so the limit of this +cor + + align:start position:0% +cor + + + align:start position:0% +cor +spread of this price of the cor spread + + align:start position:0% +spread of this price of the cor spread + + + align:start position:0% +spread of this price of the cor spread +is the digital and + + align:start position:0% +is the digital and + + + align:start position:0% +is the digital and +so we know that + + align:start position:0% + + + + align:start position:0% + +okay see this is the price at T this is + + align:start position:0% +okay see this is the price at T this is + + + align:start position:0% +okay see this is the price at T this is +the pay of capital T okay the price of + + align:start position:0% +the pay of capital T okay the price of + + + align:start position:0% +the pay of capital T okay the price of +the digital must equal just the partial + + align:start position:0% +the digital must equal just the partial + + + align:start position:0% +the digital must equal just the partial +derivative with respect to strike of the + + align:start position:0% +derivative with respect to strike of the + + + align:start position:0% +derivative with respect to strike of the +call Price + + align:start position:0% +call Price + + + align:start position:0% +call Price +okay all right so that's just + + align:start position:0% +okay all right so that's just + + + align:start position:0% +okay all right so that's just +a um nice little result uh where does + + align:start position:0% +a um nice little result uh where does + + + align:start position:0% +a um nice little result uh where does +this bring in probability okay so this + + align:start position:0% +this bring in probability okay so this + + + align:start position:0% +this bring in probability okay so this +is the next + + align:start position:0% +is the next + + + align:start position:0% +is the next +um Okay so this is where we'll make + + align:start position:0% +um Okay so this is where we'll make + + + align:start position:0% +um Okay so this is where we'll make +one um + + align:start position:0% +one um + + + align:start position:0% +one um +assumption um and it's actually a very + + align:start position:0% +assumption um and it's actually a very + + + align:start position:0% +assumption um and it's actually a very +important and fundamental assumption um + + align:start position:0% +important and fundamental assumption um + + + align:start position:0% +important and fundamental assumption um +and it's fundamental because it's called + + align:start position:0% +and it's fundamental because it's called + + + align:start position:0% +and it's fundamental because it's called +the fundamental theorem of Finance or + + align:start position:0% +the fundamental theorem of Finance or + + + align:start position:0% +the fundamental theorem of Finance or +the fundamental theorem of asset prices + + align:start position:0% +the fundamental theorem of asset prices + + + align:start position:0% +the fundamental theorem of asset prices +um + + align:start position:0% +um + + + align:start position:0% +um +so so I call this + + align:start position:0% +so so I call this + + + align:start position:0% +so so I call this +ftap fundamental theorem of asset + + align:start position:0% + + + + align:start position:0% + +pricing by this theorem which we're + + align:start position:0% +pricing by this theorem which we're + + + align:start position:0% +pricing by this theorem which we're +going to here the + + align:start position:0% +going to here the + + + align:start position:0% +going to here the +intuitive answer is correct meaning that + + align:start position:0% +intuitive answer is correct meaning that + + + align:start position:0% +intuitive answer is correct meaning that +prices today our expected values is the + + align:start position:0% +prices today our expected values is the + + + align:start position:0% +prices today our expected values is the +expectation of the future payout okay so + + align:start position:0% +expectation of the future payout okay so + + + align:start position:0% +expectation of the future payout okay so +by ftap the + + align:start position:0% +by ftap the + + + align:start position:0% +by ftap the +price at T is the + + align:start position:0% + + + + align:start position:0% + +expected + + align:start position:0% + + + + align:start position:0% + +payout at time capital P suit + + align:start position:0% + + + + align:start position:0% + +discounted + + align:start position:0% +discounted + + + align:start position:0% +discounted +so there's both something very + + align:start position:0% +so there's both something very + + + align:start position:0% +so there's both something very +straightforward here and something very + + align:start position:0% +straightforward here and something very + + + align:start position:0% +straightforward here and something very +deep right if you would think about what + + align:start position:0% +deep right if you would think about what + + + align:start position:0% +deep right if you would think about what +how much would you pay for a contract + + align:start position:0% +how much would you pay for a contract + + + align:start position:0% +how much would you pay for a contract +that gives you a dollar if an event + + align:start position:0% +that gives you a dollar if an event + + + align:start position:0% +that gives you a dollar if an event +happens in this case the event being + + align:start position:0% +happens in this case the event being + + + align:start position:0% +happens in this case the event being +stock being greater than k at maturity + + align:start position:0% +stock being greater than k at maturity + + + align:start position:0% +stock being greater than k at maturity +you would intuitively think that's + + align:start position:0% +you would intuitively think that's + + + align:start position:0% +you would intuitively think that's +related to the probability of of the + + align:start position:0% +related to the probability of of the + + + align:start position:0% +related to the probability of of the +event happening right how much would you + + align:start position:0% +event happening right how much would you + + + align:start position:0% +event happening right how much would you +pay to receive a dollar if a coin comes + + align:start position:0% +pay to receive a dollar if a coin comes + + + align:start position:0% +pay to receive a dollar if a coin comes +up ahead you'd pay a + + align:start position:0% +up ahead you'd pay a + + + align:start position:0% +up ahead you'd pay a +half probably okay it's very very + + align:start position:0% +half probably okay it's very very + + + align:start position:0% +half probably okay it's very very +intuitive + + align:start position:0% +intuitive + + + align:start position:0% +intuitive +but the deepness is that this is + + align:start position:0% +but the deepness is that this is + + + align:start position:0% +but the deepness is that this is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +holds under a particular probability + + align:start position:0% +holds under a particular probability + + + align:start position:0% +holds under a particular probability +distribution I'm not going to go go into + + align:start position:0% +distribution I'm not going to go go into + + + align:start position:0% +distribution I'm not going to go go into +that here but the by the fundamental + + align:start position:0% +that here but the by the fundamental + + + align:start position:0% +that here but the by the fundamental +theorem this is this is true okay so I + + align:start position:0% +theorem this is this is true okay so I + + + align:start position:0% +theorem this is this is true okay so I +can write in the case of the + + align:start position:0% +can write in the case of the + + + align:start position:0% +can write in the case of the +digital the digital + + align:start position:0% + + + + align:start position:0% + +price + + align:start position:0% +price + + + align:start position:0% +price +equals the + + align:start position:0% +equals the + + + align:start position:0% +equals the +discounted and we'll explain why we want + + align:start position:0% +discounted and we'll explain why we want + + + align:start position:0% +discounted and we'll explain why we want +to put the zero coupon bond price here + + align:start position:0% +to put the zero coupon bond price here + + + align:start position:0% +to put the zero coupon bond price here +that's the present value of a dollar at + + align:start position:0% +that's the present value of a dollar at + + + align:start position:0% +that's the present value of a dollar at +time T right okay that's just a discount + + align:start position:0% +time T right okay that's just a discount + + + align:start position:0% +time T right okay that's just a discount +factor it's very trivial but that's + + align:start position:0% +factor it's very trivial but that's + + + align:start position:0% +factor it's very trivial but that's +written in terms of an asset price times + + align:start position:0% +written in terms of an asset price times + + + align:start position:0% +written in terms of an asset price times +the expected value of the payout + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so okay so either you can take this as + + align:start position:0% +so okay so either you can take this as + + + align:start position:0% +so okay so either you can take this as +this makes a lot of sense the discounted + + align:start position:0% +this makes a lot of sense the discounted + + + align:start position:0% +this makes a lot of sense the discounted +expected + + align:start position:0% +expected + + + align:start position:0% +expected +payout or you can say I don't understand + + align:start position:0% +payout or you can say I don't understand + + + align:start position:0% +payout or you can say I don't understand +this I want to find out about the + + align:start position:0% +this I want to find out about the + + + align:start position:0% +this I want to find out about the +fundamental theorem of asset pricing + + align:start position:0% +fundamental theorem of asset pricing + + + align:start position:0% +fundamental theorem of asset pricing +which we will prove in my in my class + + align:start position:0% +which we will prove in my in my class + + + align:start position:0% +which we will prove in my in my class +but this is s of intuitively makes sense + + align:start position:0% +but this is s of intuitively makes sense + + + align:start position:0% +but this is s of intuitively makes sense +the key here okay is that the expected + + align:start position:0% +the key here okay is that the expected + + + align:start position:0% +the key here okay is that the expected +value actually has to be taken out under + + align:start position:0% +value actually has to be taken out under + + + align:start position:0% +value actually has to be taken out under +the appropriate distribution called the + + align:start position:0% +the appropriate distribution called the + + + align:start position:0% +the appropriate distribution called the +risk neutral distribution okay but this + + align:start position:0% +risk neutral distribution okay but this + + + align:start position:0% +risk neutral distribution okay but this +formula holds in fact + + align:start position:0% +formula holds in fact + + + align:start position:0% +formula holds in fact +strictly I write this here just + + align:start position:0% +strictly I write this here just + + + align:start position:0% +strictly I write this here just +for what holds is that the + + align:start position:0% + + + + align:start position:0% + +price at time Little T divided by the + + align:start position:0% +price at time Little T divided by the + + + align:start position:0% +price at time Little T divided by the +zero coupon + + align:start position:0% +zero coupon + + + align:start position:0% +zero coupon +Bond okay is a marting gale for those of + + align:start position:0% +Bond okay is a marting gale for those of + + + align:start position:0% +Bond okay is a marting gale for those of +you + + align:start position:0% +you + + + align:start position:0% +you +into probability + + align:start position:0% +into probability + + + align:start position:0% +into probability +Theory and this gets probabilists very + + align:start position:0% +Theory and this gets probabilists very + + + align:start position:0% +Theory and this gets probabilists very +excited of course because they love + + align:start position:0% +excited of course because they love + + + align:start position:0% +excited of course because they love +martingales everyone in probability + + align:start position:0% +martingales everyone in probability + + + align:start position:0% +martingales everyone in probability +Theory loves martingales a lot of lot of + + align:start position:0% +Theory loves martingales a lot of lot of + + + align:start position:0% +Theory loves martingales a lot of lot of +theorems about martingales and you'll + + align:start position:0% +theorems about martingales and you'll + + + align:start position:0% +theorems about martingales and you'll +see of course that this is actually a + + align:start position:0% +see of course that this is actually a + + + align:start position:0% +see of course that this is actually a +restatement of + + align:start position:0% + + + + align:start position:0% + +this um assertion okay because Zed + + align:start position:0% +this um assertion okay because Zed + + + align:start position:0% +this um assertion okay because Zed +capital D capital t is one right okay so + + align:start position:0% +capital D capital t is one right okay so + + + align:start position:0% +capital D capital t is one right okay so +this statement here is a is simply a + + align:start position:0% +this statement here is a is simply a + + + align:start position:0% +this statement here is a is simply a +reexpression of this Martingale + + align:start position:0% +reexpression of this Martingale + + + align:start position:0% +reexpression of this Martingale +condition okay so I just pause here just + + align:start position:0% +condition okay so I just pause here just + + + align:start position:0% +condition okay so I just pause here just +from a probability point of view when I + + align:start position:0% +from a probability point of view when I + + + align:start position:0% +from a probability point of view when I +Lear probability it was under David + + align:start position:0% +Lear probability it was under David + + + align:start position:0% +Lear probability it was under David +Williams who wrote the book + + align:start position:0% +Williams who wrote the book + + + align:start position:0% +Williams who wrote the book +probabilities in probability with Martin + + align:start position:0% +probabilities in probability with Martin + + + align:start position:0% +probabilities in probability with Martin +GS which is is a wonderful book and I + + align:start position:0% +GS which is is a wonderful book and I + + + align:start position:0% +GS which is is a wonderful book and I +thought Martin gals is a great thing so + + align:start position:0% +thought Martin gals is a great thing so + + + align:start position:0% +thought Martin gals is a great thing so +I sort of happy it took me about seven + + align:start position:0% +I sort of happy it took me about seven + + + align:start position:0% +I sort of happy it took me about seven +or eight years of being in finance to + + align:start position:0% +or eight years of being in finance to + + + align:start position:0% +or eight years of being in finance to +realize there a whole lot of marting + + align:start position:0% +realize there a whole lot of marting + + + align:start position:0% +realize there a whole lot of marting +girls floating around because this + + align:start position:0% +girls floating around because this + + + align:start position:0% +girls floating around because this +actual approach is formalization + + align:start position:0% +actual approach is formalization + + + align:start position:0% +actual approach is formalization +of uh asset pricing really only became + + align:start position:0% +of uh asset pricing really only became + + + align:start position:0% +of uh asset pricing really only became +embraced on the trade floor around the + + align:start position:0% +embraced on the trade floor around the + + + align:start position:0% +embraced on the trade floor around the +early 2000s even though the kind of + + align:start position:0% +early 2000s even though the kind of + + + align:start position:0% +early 2000s even though the kind of +underlying theory was always there this + + align:start position:0% +underlying theory was always there this + + + align:start position:0% +underlying theory was always there this +idea of this marting girls anyway so + + align:start position:0% +idea of this marting girls anyway so + + + align:start position:0% +idea of this marting girls anyway so +this is a + + align:start position:0% +this is a + + + align:start position:0% +this is a +um um and this of course + + align:start position:0% +um um and this of course + + + align:start position:0% +um um and this of course +is + + align:start position:0% + + + + align:start position:0% + +simply okay the expected value of the + + align:start position:0% +simply okay the expected value of the + + + align:start position:0% +simply okay the expected value of the +indicator function is just the + + align:start position:0% +indicator function is just the + + + align:start position:0% +indicator function is just the +probability of the event okay all right + + align:start position:0% +probability of the event okay all right + + + align:start position:0% +probability of the event okay all right +so + + align:start position:0% +so + + + align:start position:0% +so +now + + align:start position:0% +now + + + align:start position:0% +now +I've one by intuition just here's the + + align:start position:0% +I've one by intuition just here's the + + + align:start position:0% +I've one by intuition just here's the +probability of the payout occurring of + + align:start position:0% +probability of the payout occurring of + + + align:start position:0% +probability of the payout occurring of +price a digital I've Al price of digital + + align:start position:0% +price a digital I've Al price of digital + + + align:start position:0% +price a digital I've Al price of digital +by taking the limit of Co spreads so now + + align:start position:0% +by taking the limit of Co spreads so now + + + align:start position:0% +by taking the limit of Co spreads so now +we just going to equate + + align:start position:0% +we just going to equate + + + align:start position:0% +we just going to equate +them + + align:start position:0% +them + + + align:start position:0% +them +okay right + + align:start position:0% +okay right + + + align:start position:0% +okay right +so by equating these two prices for the + + align:start position:0% +so by equating these two prices for the + + + align:start position:0% +so by equating these two prices for the +digital I simply get that the second + + align:start position:0% +digital I simply get that the second + + + align:start position:0% +digital I simply get that the second +sorry the derivative of the call Price + + align:start position:0% +sorry the derivative of the call Price + + + align:start position:0% +sorry the derivative of the call Price +with respect to strike equals the + + align:start position:0% +with respect to strike equals the + + + align:start position:0% +with respect to strike equals the +discounted + + align:start position:0% +discounted + + + align:start position:0% +discounted +probability + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +the stock being above k + + align:start position:0% +the stock being above k + + + align:start position:0% +the stock being above k +okay I'll just reorganize a little bit + + align:start position:0% +okay I'll just reorganize a little bit + + + align:start position:0% +okay I'll just reorganize a little bit +take one minus and so I've get the + + align:start position:0% +take one minus and so I've get the + + + align:start position:0% +take one minus and so I've get the +probability that + + align:start position:0% +probability that + + + align:start position:0% +probability that +uh well I can clearly reorganize I'm + + align:start position:0% +uh well I can clearly reorganize I'm + + + align:start position:0% +uh well I can clearly reorganize I'm +going to get um all right so if I want + + align:start position:0% +going to get um all right so if I want + + + align:start position:0% +going to get um all right so if I want +to Simply get the cumulative + + align:start position:0% +to Simply get the cumulative + + + align:start position:0% +to Simply get the cumulative +distribution function it's just one + + align:start position:0% +distribution function it's just one + + + align:start position:0% +distribution function it's just one +minus this so divide here take one minus + + align:start position:0% +minus this so divide here take one minus + + + align:start position:0% +minus this so divide here take one minus +okay so I get the the cumulative + + align:start position:0% +okay so I get the the cumulative + + + align:start position:0% +okay so I get the the cumulative +distribution function for the stock + + align:start position:0% +distribution function for the stock + + + align:start position:0% +distribution function for the stock +price at T is equal to 1 plus the d c by + + align:start position:0% +price at T is equal to 1 plus the d c by + + + align:start position:0% +price at T is equal to 1 plus the d c by +DK * 1 / + + align:start position:0% +DK * 1 / + + + align:start position:0% +DK * 1 / +Z right just rearranging so here now is + + align:start position:0% +Z right just rearranging so here now is + + + align:start position:0% +Z right just rearranging so here now is +the cumulative distribution function + + align:start position:0% +the cumulative distribution function + + + align:start position:0% +the cumulative distribution function +clearly I just need to differentiate + + align:start position:0% +clearly I just need to differentiate + + + align:start position:0% +clearly I just need to differentiate +again to get the probability density + + align:start position:0% +again to get the probability density + + + align:start position:0% +again to get the probability density +function right + + align:start position:0% +function right + + + align:start position:0% +function right +so um now here's where the little + + align:start position:0% +so um now here's where the little + + + align:start position:0% +so um now here's where the little +notation gets gets kind of messy but + + align:start position:0% +notation gets gets kind of messy but + + + align:start position:0% +notation gets gets kind of messy but +clearly the probability density function + + align:start position:0% +clearly the probability density function + + + align:start position:0% +clearly the probability density function +of so + + align:start position:0% +of so + + + align:start position:0% +of so +F okay for + + align:start position:0% +F okay for + + + align:start position:0% +F okay for +my um random variable f subt right the + + align:start position:0% +my um random variable f subt right the + + + align:start position:0% +my um random variable f subt right the +density of Express that is I always + + align:start position:0% +density of Express that is I always + + + align:start position:0% +density of Express that is I always +funny problem when you talk about + + align:start position:0% +funny problem when you talk about + + + align:start position:0% +funny problem when you talk about +densities they always got want to say f + + align:start position:0% +densities they always got want to say f + + + align:start position:0% +densities they always got want to say f +ofx and it's the same with me as f of x + + align:start position:0% +ofx and it's the same with me as f of x + + + align:start position:0% +ofx and it's the same with me as f of x +is the density is simply just the next + + align:start position:0% +is the density is simply just the next + + + align:start position:0% +is the density is simply just the next +the second derivative we take the + + align:start position:0% +the second derivative we take the + + + align:start position:0% +the second derivative we take the +derivative of this is the second + + align:start position:0% +derivative of this is the second + + + align:start position:0% +derivative of this is the second +derivative of the core price with + + align:start position:0% +derivative of the core price with + + + align:start position:0% +derivative of the core price with +respect to strike evaluated at Little X + + align:start position:0% +respect to strike evaluated at Little X + + + align:start position:0% +respect to strike evaluated at Little X +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so all right so what we've done here is + + align:start position:0% +so all right so what we've done here is + + + align:start position:0% +so all right so what we've done here is +start off with simple definition of + + align:start position:0% +start off with simple definition of + + + align:start position:0% +start off with simple definition of +three assets priced the digital in two + + align:start position:0% +three assets priced the digital in two + + + align:start position:0% +three assets priced the digital in two +different ways and now we have a rather + + align:start position:0% +different ways and now we have a rather + + + align:start position:0% +different ways and now we have a rather +elegant linkage between call + + align:start position:0% +elegant linkage between call + + + align:start position:0% +elegant linkage between call +prices Okay C and the + + align:start position:0% +prices Okay C and the + + + align:start position:0% +prices Okay C and the +density uh of the random variable that + + align:start position:0% +density uh of the random variable that + + + align:start position:0% +density uh of the random variable that +is the underlying stock price at capital + + align:start position:0% +is the underlying stock price at capital + + + align:start position:0% +is the underlying stock price at capital +t Okay so we've established one side of + + align:start position:0% +t Okay so we've established one side of + + + align:start position:0% +t Okay so we've established one side of +The Duality which is given the set set + + align:start position:0% +The Duality which is given the set set + + + align:start position:0% +The Duality which is given the set set +of call + + align:start position:0% +of call + + + align:start position:0% +of call +prices for all + + align:start position:0% +prices for all + + + align:start position:0% +prices for all +K okay I can then uniquely determine the + + align:start position:0% +K okay I can then uniquely determine the + + + align:start position:0% +K okay I can then uniquely determine the +density + + align:start position:0% +density + + + align:start position:0% +density +of of the underlying asset + + align:start position:0% + + + + align:start position:0% + +okay okay so that might think okay this + + align:start position:0% +okay okay so that might think okay this + + + align:start position:0% +okay okay so that might think okay this +is um this kind of nice how does this + + align:start position:0% +is um this kind of nice how does this + + + align:start position:0% +is um this kind of nice how does this +actually work in practice + + align:start position:0% +actually work in practice + + + align:start position:0% +actually work in practice +um do we actually think in terms of + + align:start position:0% +um do we actually think in terms of + + + align:start position:0% +um do we actually think in terms of +probability trading right we just said + + align:start position:0% +probability trading right we just said + + + align:start position:0% +probability trading right we just said +that call options are equivalent to + + align:start position:0% +that call options are equivalent to + + + align:start position:0% +that call options are equivalent to +probability density functions well + + align:start position:0% +probability density functions well + + + align:start position:0% +probability density functions well +actually there's a very neat way of + + align:start position:0% +actually there's a very neat way of + + + align:start position:0% +actually there's a very neat way of +accessing this density function through + + align:start position:0% +accessing this density function through + + + align:start position:0% +accessing this density function through +another portfolio of options okay so + + align:start position:0% +another portfolio of options okay so + + + align:start position:0% +another portfolio of options okay so +this is actually where we get to me sort + + align:start position:0% +this is actually where we get to me sort + + + align:start position:0% +this is actually where we get to me sort +of practical relevance of some of this + + align:start position:0% +of practical relevance of some of this + + + align:start position:0% +of practical relevance of some of this +Theory so let me just um show you that + + align:start position:0% +Theory so let me just um show you that + + + align:start position:0% +Theory so let me just um show you that +okay so we're going to consider another + + align:start position:0% +okay so we're going to consider another + + + align:start position:0% +okay so we're going to consider another +portfol + + align:start position:0% +portfol + + + align:start position:0% +portfol +okay so here we + + align:start position:0% +okay so here we + + + align:start position:0% +okay so here we +consider + + align:start position:0% +consider + + + align:start position:0% +consider +portfolio as + + align:start position:0% +portfolio as + + + align:start position:0% +portfolio as +follows okay it's actually going to be + + align:start position:0% +follows okay it's actually going to be + + + align:start position:0% +follows okay it's actually going to be +the difference between two call spreads + + align:start position:0% +the difference between two call spreads + + + align:start position:0% +the difference between two call spreads +so Lambda + + align:start position:0% +so Lambda + + + align:start position:0% +so Lambda +calls with + + align:start position:0% +calls with + + + align:start position:0% +calls with +strike K minus 1/ + + align:start position:0% +strike K minus 1/ + + + align:start position:0% +strike K minus 1/ +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +okay uh minus two Lambda + + align:start position:0% +okay uh minus two Lambda + + + align:start position:0% +okay uh minus two Lambda +calls with strike + + align:start position:0% + + + + align:start position:0% + +K and Lambda + + align:start position:0% +K and Lambda + + + align:start position:0% +K and Lambda +calls with strike K plus one over Lambda + + align:start position:0% +calls with strike K plus one over Lambda + + + align:start position:0% +calls with strike K plus one over Lambda +again Lambda + + align:start position:0% + + + + align:start position:0% + +positive okay all right why are we doing + + align:start position:0% +positive okay all right why are we doing + + + align:start position:0% +positive okay all right why are we doing +this let's just stop for a bit of + + align:start position:0% +this let's just stop for a bit of + + + align:start position:0% +this let's just stop for a bit of +intuition here we've seen that the cor + + align:start position:0% +intuition here we've seen that the cor + + + align:start position:0% +intuition here we've seen that the cor +spread so obviously the discrete + + align:start position:0% +spread so obviously the discrete + + + align:start position:0% +spread so obviously the discrete +approximation to the first + + align:start position:0% +approximation to the first + + + align:start position:0% +approximation to the first +derivative of cor price with respect to + + align:start position:0% +derivative of cor price with respect to + + + align:start position:0% +derivative of cor price with respect to +strike so clearly if I want to + + align:start position:0% +strike so clearly if I want to + + + align:start position:0% +strike so clearly if I want to +approximate the second derivative I'm + + align:start position:0% +approximate the second derivative I'm + + + align:start position:0% +approximate the second derivative I'm +going to take the difference between two + + align:start position:0% +going to take the difference between two + + + align:start position:0% +going to take the difference between two +Co spreads appropriately scaled okay you + + align:start position:0% +Co spreads appropriately scaled okay you + + + align:start position:0% +Co spreads appropriately scaled okay you +know I'm going to have to have a do + + align:start position:0% +know I'm going to have to have a do + + + align:start position:0% +know I'm going to have to have a do +there's going to have to be another + + align:start position:0% +there's going to have to be another + + + align:start position:0% +there's going to have to be another +Lambda coming in here at some point this + + align:start position:0% +Lambda coming in here at some point this + + + align:start position:0% +Lambda coming in here at some point this +is just a difference between two Co + + align:start position:0% +is just a difference between two Co + + + align:start position:0% +is just a difference between two Co +spreads so that's the difference between + + align:start position:0% +spreads so that's the difference between + + + align:start position:0% +spreads so that's the difference between +two approximations of the first + + align:start position:0% +two approximations of the first + + + align:start position:0% +two approximations of the first +derivative so I'm going to have to scale + + align:start position:0% +derivative so I'm going to have to scale + + + align:start position:0% +derivative so I'm going to have to scale +by Lambda in order to approximate the + + align:start position:0% +by Lambda in order to approximate the + + + align:start position:0% +by Lambda in order to approximate the +second derivative okay so this is + + align:start position:0% +second derivative okay so this is + + + align:start position:0% +second derivative okay so this is +actually called a CO butterfly + + align:start position:0% + + + + align:start position:0% + +and this is a beautiful thing for two + + align:start position:0% +and this is a beautiful thing for two + + + align:start position:0% +and this is a beautiful thing for two +reasons one is they actually trade a lot + + align:start position:0% +reasons one is they actually trade a lot + + + align:start position:0% +reasons one is they actually trade a lot +surprisingly this is not a contrived + + align:start position:0% +surprisingly this is not a contrived + + + align:start position:0% +surprisingly this is not a contrived +thing that I just made up a it trades a + + align:start position:0% +thing that I just made up a it trades a + + + align:start position:0% +thing that I just made up a it trades a +lot so you can actually trade this thing + + align:start position:0% +lot so you can actually trade this thing + + + align:start position:0% +lot so you can actually trade this thing +and the second is as you can kind of + + align:start position:0% +and the second is as you can kind of + + + align:start position:0% +and the second is as you can kind of +imagine the right scaling of this core + + align:start position:0% +imagine the right scaling of this core + + + align:start position:0% +imagine the right scaling of this core +butterfly is going to approximate this + + align:start position:0% +butterfly is going to approximate this + + + align:start position:0% +butterfly is going to approximate this +second derivative and that's + + align:start position:0% +second derivative and that's + + + align:start position:0% +second derivative and that's +approximating the density function so + + align:start position:0% +approximating the density function so + + + align:start position:0% +approximating the density function so +this is a traded + + align:start position:0% +this is a traded + + + align:start position:0% +this is a traded +object kind of approximate the the + + align:start position:0% +object kind of approximate the the + + + align:start position:0% +object kind of approximate the the +density function + + align:start position:0% +density function + + + align:start position:0% +density function +yeah but in real world you can + + align:start position:0% +yeah but in real world you can + + + align:start position:0% +yeah but in real world you can +distance like small so they have some + + align:start position:0% +distance like small so they have some + + + align:start position:0% +distance like small so they have some +way how can approximate that yeah so + + align:start position:0% +way how can approximate that yeah so + + + align:start position:0% +way how can approximate that yeah so +it's a good point we're not going to be + + align:start position:0% +it's a good point we're not going to be + + + align:start position:0% +it's a good point we're not going to be +yeah so the question is how in practice + + align:start position:0% +yeah so the question is how in practice + + + align:start position:0% +yeah so the question is how in practice +we can't go infinitely small which is + + align:start position:0% +we can't go infinitely small which is + + + align:start position:0% +we can't go infinitely small which is +true but in we can go pretty small so in + + align:start position:0% +true but in we can go pretty small so in + + + align:start position:0% +true but in we can go pretty small so in +interest rates we might be able to trade + + align:start position:0% +interest rates we might be able to trade + + + align:start position:0% +interest rates we might be able to trade +a you know one 50 160 + + align:start position:0% +a you know one 50 160 + + + align:start position:0% +a you know one 50 160 +170 call butterfly or equivalent 10 + + align:start position:0% +170 call butterfly or equivalent 10 + + + align:start position:0% +170 call butterfly or equivalent 10 +basis points wide that's a re I mean + + align:start position:0% +basis points wide that's a re I mean + + + align:start position:0% +basis points wide that's a re I mean +it's a reasonable approximation to the + + align:start position:0% +it's a reasonable approximation to the + + + align:start position:0% +it's a reasonable approximation to the +probability of being in that interval + + align:start position:0% +probability of being in that interval + + + align:start position:0% +probability of being in that interval +okay so so these are all I mean you make + + align:start position:0% +okay so so these are all I mean you make + + + align:start position:0% +okay so so these are all I mean you make +a good point that I mean in fact all of + + align:start position:0% +a good point that I mean in fact all of + + + align:start position:0% +a good point that I mean in fact all of +Finance is discreet in my view so + + align:start position:0% +Finance is discreet in my view so + + + align:start position:0% +Finance is discreet in my view so +continuous Time Finance is done in + + align:start position:0% +continuous Time Finance is done in + + + align:start position:0% +continuous Time Finance is done in +continuous time because the theory is + + align:start position:0% +continuous time because the theory is + + + align:start position:0% +continuous time because the theory is +much more + + align:start position:0% +much more + + + align:start position:0% +much more +elegant but in practice it's all + + align:start position:0% +elegant but in practice it's all + + + align:start position:0% +elegant but in practice it's all +discreete in time and space okay right + + align:start position:0% +discreete in time and space okay right + + + align:start position:0% +discreete in time and space okay right +you can only trade finally off in a day + + align:start position:0% +you can only trade finally off in a day + + + align:start position:0% +you can only trade finally off in a day +and so on okay um I'm going go into the + + align:start position:0% +and so on okay um I'm going go into the + + + align:start position:0% +and so on okay um I'm going go into the +the detail but you can see the price let + + align:start position:0% +the detail but you can see the price let + + + align:start position:0% +the detail but you can see the price let +me just write down the first the price + + align:start position:0% +me just write down the first the price + + + align:start position:0% +me just write down the first the price +of + + align:start position:0% +of + + + align:start position:0% +of +this right I just Express as the + + align:start position:0% +this right I just Express as the + + + align:start position:0% +this right I just Express as the +difference between two cor + + align:start position:0% +difference between two cor + + + align:start position:0% +difference between two cor +spreads so it's Lambda + + align:start position:0% +spreads so it's Lambda + + + align:start position:0% +spreads so it's Lambda +times the co spread from 1us Lambda to + + align:start position:0% + + + + align:start position:0% + +um to K so K1 minus Lambda to to K minus + + align:start position:0% +um to K so K1 minus Lambda to to K minus + + + align:start position:0% +um to K so K1 minus Lambda to to K minus +the call spread + + align:start position:0% + + + + align:start position:0% + +from K to k+ 1/ + + align:start position:0% + + + + align:start position:0% + +Lambda okay so difference between two + + align:start position:0% +Lambda okay so difference between two + + + align:start position:0% +Lambda okay so difference between two +cor spreads + + align:start position:0% +cor spreads + + + align:start position:0% +cor spreads +um we'll call this this is the butterfly + + align:start position:0% +um we'll call this this is the butterfly + + + align:start position:0% +um we'll call this this is the butterfly +we're just going to use temporary + + align:start position:0% +we're just going to use temporary + + + align:start position:0% +we're just going to use temporary +notation call that b b for butterfly um + + align:start position:0% +notation call that b b for butterfly um + + + align:start position:0% +notation call that b b for butterfly um +so the price B and then you get confused + + align:start position:0% +so the price B and then you get confused + + + align:start position:0% +so the price B and then you get confused +it's B centered at K with width Lambda + + align:start position:0% +it's B centered at K with width Lambda + + + align:start position:0% +it's B centered at K with width Lambda +no one ever uses notation outside this + + align:start position:0% +no one ever uses notation outside this + + + align:start position:0% +no one ever uses notation outside this +one section of my class so that's a + + align:start position:0% +one section of my class so that's a + + + align:start position:0% +one section of my class so that's a +that's why but it's just handy for this + + align:start position:0% +that's why but it's just handy for this + + + align:start position:0% +that's why but it's just handy for this +so that is the butterfly price is equal + + align:start position:0% +so that is the butterfly price is equal + + + align:start position:0% +so that is the butterfly price is equal +to the difference between these two call + + align:start position:0% +to the difference between these two call + + + align:start position:0% +to the difference between these two call +spreads what I want to do is I want to + + align:start position:0% +spreads what I want to do is I want to + + + align:start position:0% +spreads what I want to do is I want to +take limits of this suitably scal to get + + align:start position:0% +take limits of this suitably scal to get + + + align:start position:0% +take limits of this suitably scal to get +the second derivative and the if you + + align:start position:0% +the second derivative and the if you + + + align:start position:0% +the second derivative and the if you +uh do you just need to take Lambda time + + align:start position:0% +uh do you just need to take Lambda time + + + align:start position:0% +uh do you just need to take Lambda time +BK of + + align:start position:0% +BK of + + + align:start position:0% +BK of +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +TT is indeed approximately if I take + + align:start position:0% +TT is indeed approximately if I take + + + align:start position:0% +TT is indeed approximately if I take +limits is is exactly the second + + align:start position:0% +limits is is exactly the second + + + align:start position:0% +limits is is exactly the second +derivative + + align:start position:0% + + + + align:start position:0% + +of the core + + align:start position:0% + + + + align:start position:0% + +price okay so right here's here here's + + align:start position:0% +price okay so right here's here here's + + + align:start position:0% +price okay so right here's here here's +how I'm accessing the second derivative + + align:start position:0% +how I'm accessing the second derivative + + + align:start position:0% +how I'm accessing the second derivative +through a portfolio of traded options + + align:start position:0% +through a portfolio of traded options + + + align:start position:0% +through a portfolio of traded options +all right and + + align:start position:0% +all right and + + + align:start position:0% +all right and +so the price of this butterfly B if I + + align:start position:0% +so the price of this butterfly B if I + + + align:start position:0% +so the price of this butterfly B if I +just reorganize and + + align:start position:0% +just reorganize and + + + align:start position:0% +just reorganize and +substitute okay so um I get + + align:start position:0% +substitute okay so um I get + + + align:start position:0% +substitute okay so um I get +BK for small lamb sorry for large Lambda + + align:start position:0% +BK for small lamb sorry for large Lambda + + + align:start position:0% +BK for small lamb sorry for large Lambda +I a small + + align:start position:0% +I a small + + + align:start position:0% +I a small +interval okay is approximately 1/ Lambda + + align:start position:0% +interval okay is approximately 1/ Lambda + + + align:start position:0% +interval okay is approximately 1/ Lambda +times the density + + align:start position:0% + + + + align:start position:0% + +function okay actually evaluated at + + align:start position:0% +function okay actually evaluated at + + + align:start position:0% +function okay actually evaluated at +K right so I + + align:start position:0% +K right so I + + + align:start position:0% +K right so I +have obtained this density + + align:start position:0% +have obtained this density + + + align:start position:0% +have obtained this density +function + + align:start position:0% +function + + + align:start position:0% +function +um by this traded portfolio and to your + + align:start position:0% +um by this traded portfolio and to your + + + align:start position:0% +um by this traded portfolio and to your +to your point about we haven't we're not + + align:start position:0% +to your point about we haven't we're not + + + align:start position:0% +to your point about we haven't we're not +we're not getting infinitely small + + align:start position:0% +we're not getting infinitely small + + + align:start position:0% +we're not getting infinitely small +that's absolutely right but if if you + + align:start position:0% +that's absolutely right but if if you + + + align:start position:0% +that's absolutely right but if if you +think about what the density you know + + align:start position:0% +think about what the density you know + + + align:start position:0% +think about what the density you know +when you learn about density functions + + align:start position:0% +when you learn about density functions + + + align:start position:0% +when you learn about density functions +for the for the first time you say the + + align:start position:0% +for the for the first time you say the + + + align:start position:0% +for the for the first time you say the +density function at x times a small + + align:start position:0% +density function at x times a small + + + align:start position:0% +density function at x times a small +interval is the probability of being in + + align:start position:0% +interval is the probability of being in + + + align:start position:0% +interval is the probability of being in +that small interval right so you know + + align:start position:0% +that small interval right so you know + + + align:start position:0% +that small interval right so you know +when we think about the density + + align:start position:0% +when we think about the density + + + align:start position:0% +when we think about the density +function f ofx if we have a small + + align:start position:0% +function f ofx if we have a small + + + align:start position:0% +function f ofx if we have a small +interval of width Delta + + align:start position:0% + + + + align:start position:0% + +X okay then clearly the probability of + + align:start position:0% +X okay then clearly the probability of + + + align:start position:0% +X okay then clearly the probability of +being in this interval is approximately + + align:start position:0% +being in this interval is approximately + + + align:start position:0% +being in this interval is approximately +F ofx Delta X + + align:start position:0% +F ofx Delta X + + + align:start position:0% +F ofx Delta X +right okay liit that is true so what + + align:start position:0% +right okay liit that is true so what + + + align:start position:0% +right okay liit that is true so what +we're showing here if you actually think + + align:start position:0% +we're showing here if you actually think + + + align:start position:0% +we're showing here if you actually think +about what interval we're looking at + + align:start position:0% +about what interval we're looking at + + + align:start position:0% +about what interval we're looking at +we're actually looking at in this cor + + align:start position:0% +we're actually looking at in this cor + + + align:start position:0% +we're actually looking at in this cor +butterfly if you actually to draw it out + + align:start position:0% +butterfly if you actually to draw it out + + + align:start position:0% +butterfly if you actually to draw it out +this cor + + align:start position:0% +this cor + + + align:start position:0% +this cor +butterfly this is looks like + + align:start position:0% +butterfly this is looks like + + + align:start position:0% +butterfly this is looks like +that around + + align:start position:0% +that around + + + align:start position:0% +that around +K it actually so it's a little triangle + + align:start position:0% +K it actually so it's a little triangle + + + align:start position:0% +K it actually so it's a little triangle +it's not actually a rectangle but it's a + + align:start position:0% +it's not actually a rectangle but it's a + + + align:start position:0% +it's not actually a rectangle but it's a +little triangle of width 2 over Lambda + + align:start position:0% +little triangle of width 2 over Lambda + + + align:start position:0% +little triangle of width 2 over Lambda +okay so it is actually this is the + + align:start position:0% +okay so it is actually this is the + + + align:start position:0% +okay so it is actually this is the +area right of the of this triangle right + + align:start position:0% +area right of the of this triangle right + + + align:start position:0% +area right of the of this triangle right +it's 2 Lambda time half time f x and + + align:start position:0% +it's 2 Lambda time half time f x and + + + align:start position:0% +it's 2 Lambda time half time f x and +that's + + align:start position:0% +that's + + + align:start position:0% +that's +actually this right so this is this is + + align:start position:0% +actually this right so this is this is + + + align:start position:0% +actually this right so this is this is +this has width two over + + align:start position:0% +this has width two over + + + align:start position:0% +this has width two over +Lambda okay so in fact we've got here + + align:start position:0% +Lambda okay so in fact we've got here + + + align:start position:0% +Lambda okay so in fact we've got here +exactly an approxim exactly exactly + + align:start position:0% +exactly an approxim exactly exactly + + + align:start position:0% +exactly an approxim exactly exactly +approximation that doesn't sound right + + align:start position:0% +approximation that doesn't sound right + + + align:start position:0% +approximation that doesn't sound right +but is entirely analogous to the + + align:start position:0% +but is entirely analogous to the + + + align:start position:0% +but is entirely analogous to the +approximation of the probability of + + align:start position:0% +approximation of the probability of + + + align:start position:0% +approximation of the probability of +being in a small interval here is the + + align:start position:0% +being in a small interval here is the + + + align:start position:0% +being in a small interval here is the +the probability of being in this this + + align:start position:0% +the probability of being in this this + + + align:start position:0% +the probability of being in this this +inter + + align:start position:0% +inter + + + align:start position:0% +inter +here okay just the area under that is + + align:start position:0% +here okay just the area under that is + + + align:start position:0% +here okay just the area under that is +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +um one over lamb F ofx okay so here is + + align:start position:0% +um one over lamb F ofx okay so here is + + + align:start position:0% +um one over lamb F ofx okay so here is +actually something that people do do is + + align:start position:0% +actually something that people do do is + + + align:start position:0% +actually something that people do do is +they say okay I will look + + align:start position:0% +they say okay I will look + + + align:start position:0% +they say okay I will look +at the price of this + + align:start position:0% +at the price of this + + + align:start position:0% +at the price of this +butterfly okay which gives me the + + align:start position:0% +butterfly okay which gives me the + + + align:start position:0% +butterfly okay which gives me the +probability of this underlying random + + align:start position:0% +probability of this underlying random + + + align:start position:0% +probability of this underlying random +variable ending up around + + align:start position:0% +variable ending up around + + + align:start position:0% +variable ending up around +K and I'll make a judgment whether I + + align:start position:0% +K and I'll make a judgment whether I + + + align:start position:0% +K and I'll make a judgment whether I +agree with that probability or not + + align:start position:0% +agree with that probability or not + + + align:start position:0% +agree with that probability or not +and if I think that + + align:start position:0% +and if I think that + + + align:start position:0% +and if I think that +probability is higher + + align:start position:0% +probability is higher + + + align:start position:0% +probability is higher +than this price + + align:start position:0% +than this price + + + align:start position:0% +than this price +implies then I'll do a trade I'll buy it + + align:start position:0% +implies then I'll do a trade I'll buy it + + + align:start position:0% +implies then I'll do a trade I'll buy it +I'll buy that + + align:start position:0% +I'll buy that + + + align:start position:0% +I'll buy that +butterfly so there is actually a an + + align:start position:0% +butterfly so there is actually a an + + + align:start position:0% +butterfly so there is actually a an +active Market in butterflies and so I + + align:start position:0% +active Market in butterflies and so I + + + align:start position:0% +active Market in butterflies and so I +like to think an active trading in + + align:start position:0% +like to think an active trading in + + + align:start position:0% +like to think an active trading in +probabilities right probabilities of the + + align:start position:0% +probabilities right probabilities of the + + + align:start position:0% +probabilities right probabilities of the +underlying variable being um at K at + + align:start position:0% +underlying variable being um at K at + + + align:start position:0% +underlying variable being um at K at +maturity + + align:start position:0% +maturity + + + align:start position:0% +maturity +okay right so um okay so that's the + + align:start position:0% +okay right so um okay so that's the + + + align:start position:0% +okay right so um okay so that's the +first the first linkage here both the + + align:start position:0% +first the first linkage here both the + + + align:start position:0% +first the first linkage here both the +density is the second derivative and the + + align:start position:0% +density is the second derivative and the + + + align:start position:0% +density is the second derivative and the +second derivative is essentially a + + align:start position:0% +second derivative is essentially a + + + align:start position:0% +second derivative is essentially a +portfolio of traded options and none of + + align:start position:0% +portfolio of traded options and none of + + + align:start position:0% +portfolio of traded options and none of +this is dependent on the actual price of + + align:start position:0% +this is dependent on the actual price of + + + align:start position:0% +this is dependent on the actual price of +the call option in the sense that this + + align:start position:0% +the call option in the sense that this + + + align:start position:0% +the call option in the sense that this +holds regardless clearly this is a + + align:start position:0% +holds regardless clearly this is a + + + align:start position:0% +holds regardless clearly this is a +function of the price of the call option + + align:start position:0% +function of the price of the call option + + + align:start position:0% +function of the price of the call option +but I don't need any model for the + + align:start position:0% +but I don't need any model for the + + + align:start position:0% +but I don't need any model for the +option price to hold in order for the + + align:start position:0% +option price to hold in order for the + + + align:start position:0% +option price to hold in order for the +these relationships to hold right so + + align:start position:0% +these relationships to hold right so + + + align:start position:0% +these relationships to hold right so +this is model independent relationships + + align:start position:0% +this is model independent relationships + + + align:start position:0% +this is model independent relationships +clearly if you were + + align:start position:0% +clearly if you were + + + align:start position:0% +clearly if you were +to put the black shs formula into + + align:start position:0% +to put the black shs formula into + + + align:start position:0% +to put the black shs formula into +C okay black sh formula of the call + + align:start position:0% +C okay black sh formula of the call + + + align:start position:0% +C okay black sh formula of the call +Price and take the second derivative + + align:start position:0% +Price and take the second derivative + + + align:start position:0% +Price and take the second derivative +with respect to K which would be a mess + + align:start position:0% +with respect to K which would be a mess + + + align:start position:0% +with respect to K which would be a mess +you'll end up with a log normal + + align:start position:0% +you'll end up with a log normal + + + align:start position:0% +you'll end up with a log normal +distribution right because that's what + + align:start position:0% +distribution right because that's what + + + align:start position:0% +distribution right because that's what +actually the black shs formula is is + + align:start position:0% +actually the black shs formula is is + + + align:start position:0% +actually the black shs formula is is +expected value of the payout under a log + + align:start position:0% +expected value of the payout under a log + + + align:start position:0% +expected value of the payout under a log +normal distribution and that will hold + + align:start position:0% +normal distribution and that will hold + + + align:start position:0% +normal distribution and that will hold +okay so this will hold for + + align:start position:0% +okay so this will hold for + + + align:start position:0% +okay so this will hold for +okay + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +deps yes it does but right does not + + align:start position:0% +deps yes it does but right does not + + + align:start position:0% +deps yes it does but right does not +what's what's the role of that yeah so + + align:start position:0% +what's what's the role of that yeah so + + + align:start position:0% +what's what's the role of that yeah so +it's a really good point and I've been + + align:start position:0% +it's a really good point and I've been + + + align:start position:0% +it's a really good point and I've been +loose in my notation so here what is it + + align:start position:0% +loose in my notation so here what is it + + + align:start position:0% +loose in my notation so here what is it +it's actually the conditional + + align:start position:0% +it's actually the conditional + + + align:start position:0% +it's actually the conditional +distribution of S capital T given s + + align:start position:0% +distribution of S capital T given s + + + align:start position:0% +distribution of S capital T given s +Little T so this is the conditional + + align:start position:0% +Little T so this is the conditional + + + align:start position:0% +Little T so this is the conditional +distribution given that we're currently + + align:start position:0% +distribution given that we're currently + + + align:start position:0% +distribution given that we're currently +at time Little T with price s Little T + + align:start position:0% +at time Little T with price s Little T + + + align:start position:0% +at time Little T with price s Little T +or for the distribution at time capital + + align:start position:0% +or for the distribution at time capital + + + align:start position:0% +or for the distribution at time capital +T so that's where that's where it comes + + align:start position:0% +T so that's where that's where it comes + + + align:start position:0% +T so that's where that's where it comes +in it's absolutely right so in fact a + + align:start position:0% +in it's absolutely right so in fact a + + + align:start position:0% +in it's absolutely right so in fact a +lot of um this expected value right + + align:start position:0% +lot of um this expected value right + + + align:start position:0% +lot of um this expected value right +strictly should be conditional on + + align:start position:0% +strictly should be conditional on + + + align:start position:0% +strictly should be conditional on +St okay this probability is a + + align:start position:0% +St okay this probability is a + + + align:start position:0% +St okay this probability is a +probability conditional on St absolutely + + align:start position:0% +probability conditional on St absolutely + + + align:start position:0% +probability conditional on St absolutely +okay and in fact this Martingale + + align:start position:0% +okay and in fact this Martingale + + + align:start position:0% +okay and in fact this Martingale +condition is the marting GS with respect + + align:start position:0% +condition is the marting GS with respect + + + align:start position:0% +condition is the marting GS with respect +to s t Okay well may okay so that where + + align:start position:0% +to s t Okay well may okay so that where + + + align:start position:0% +to s t Okay well may okay so that where +the little t comes comes + + align:start position:0% + + + + align:start position:0% + +in here yes sorry there's one over + + align:start position:0% +in here yes sorry there's one over + + + align:start position:0% +in here yes sorry there's one over +Z that's right this just a constant here + + align:start position:0% +Z that's right this just a constant here + + + align:start position:0% +Z that's right this just a constant here +this is this number especially s + + align:start position:0% +this is this number especially s + + + align:start position:0% +this is this number especially s +especially because interest rates are so + + align:start position:0% +especially because interest rates are so + + + align:start position:0% +especially because interest rates are so +low in the US so this number is so close + + align:start position:0% +low in the US so this number is so close + + + align:start position:0% +low in the US so this number is so close +to one that you always forget about that + + align:start position:0% +to one that you always forget about that + + + align:start position:0% +to one that you always forget about that +I mean not when we're trading but when + + align:start position:0% +I mean not when we're trading but when + + + align:start position:0% +I mean not when we're trading but when +you sort of oh well that's just a you + + align:start position:0% +you sort of oh well that's just a you + + + align:start position:0% +you sort of oh well that's just a you +just think about which one is um this is + + align:start position:0% +just think about which one is um this is + + + align:start position:0% +just think about which one is um this is +a quantity that's in the future right + + align:start position:0% +a quantity that's in the future right + + + align:start position:0% +a quantity that's in the future right +because it's C prices okay any say + + align:start position:0% +because it's C prices okay any say + + + align:start position:0% +because it's C prices okay any say +that's how we going + + align:start position:0% +that's how we going + + + align:start position:0% +that's how we going +to so all right so that's that's the + + align:start position:0% +to so all right so that's that's the + + + align:start position:0% +to so all right so that's that's the +first the first bit + + align:start position:0% + + + + align:start position:0% + +um so um when I when I was uh an + + align:start position:0% +um so um when I when I was uh an + + + align:start position:0% +um so um when I when I was uh an +undergraduate actually learning + + align:start position:0% +undergraduate actually learning + + + align:start position:0% +undergraduate actually learning +probability one thing I learned about + + align:start position:0% +probability one thing I learned about + + + align:start position:0% +probability one thing I learned about +probability was from my probability + + align:start position:0% +probability was from my probability + + + align:start position:0% +probability was from my probability +lecturer who said the attention span of + + align:start position:0% +lecturer who said the attention span of + + + align:start position:0% +lecturer who said the attention span of +students is no more than about 40 + + align:start position:0% +students is no more than about 40 + + + align:start position:0% +students is no more than about 40 +minutes so there's no point lecturing + + align:start position:0% +minutes so there's no point lecturing + + + align:start position:0% +minutes so there's no point lecturing +continuously for 40 minutes because + + align:start position:0% +continuously for 40 minutes because + + + align:start position:0% +continuously for 40 minutes because +people will start you know they'll just + + align:start position:0% +people will start you know they'll just + + + align:start position:0% +people will start you know they'll just +start switching off after 40 minutes so + + align:start position:0% +start switching off after 40 minutes so + + + align:start position:0% +start switching off after 40 minutes so +rather than wait just have a break and + + align:start position:0% +rather than wait just have a break and + + + align:start position:0% +rather than wait just have a break and +waste of time the lecturer said I'm just + + align:start position:0% +waste of time the lecturer said I'm just + + + align:start position:0% +waste of time the lecturer said I'm just +going to give you some random + + align:start position:0% +going to give you some random + + + align:start position:0% +going to give you some random +information in a break and then we'll go + + align:start position:0% +information in a break and then we'll go + + + align:start position:0% +information in a break and then we'll go +back to probability so I learned that + + align:start position:0% +back to probability so I learned that + + + align:start position:0% +back to probability so I learned that +from 25 years ago I can't remember you + + align:start position:0% +from 25 years ago I can't remember you + + + align:start position:0% +from 25 years ago I can't remember you +know I actually remember the material I + + align:start position:0% +know I actually remember the material I + + + align:start position:0% +know I actually remember the material I +can't remember any of the random + + align:start position:0% +can't remember any of the random + + + align:start position:0% +can't remember any of the random +material so that's what I do in my + + align:start position:0% +material so that's what I do in my + + + align:start position:0% +material so that's what I do in my +lectures is I break them up and and talk + + align:start position:0% +lectures is I break them up and and talk + + + align:start position:0% +lectures is I break them up and and talk +about something something random so I + + align:start position:0% +about something something random so I + + + align:start position:0% +about something something random so I +thought I'd do that here as well with + + align:start position:0% +thought I'd do that here as well with + + + align:start position:0% +thought I'd do that here as well with +with some not completely random so this + + align:start position:0% +with some not completely random so this + + + align:start position:0% +with some not completely random so this +is somewhat applicable this being a math + + align:start position:0% +is somewhat applicable this being a math + + + align:start position:0% +is somewhat applicable this being a math +class so um so uh how many of you are + + align:start position:0% +class so um so uh how many of you are + + + align:start position:0% +class so um so uh how many of you are +math concentrators or applied math + + align:start position:0% +math concentrators or applied math + + + align:start position:0% +math concentrators or applied math +concentrators one okay a lot okay + + align:start position:0% +concentrators one okay a lot okay + + + align:start position:0% +concentrators one okay a lot okay +applied math concentrators okay + + align:start position:0% +applied math concentrators okay + + + align:start position:0% +applied math concentrators okay +especially for the applied math + + align:start position:0% +especially for the applied math + + + align:start position:0% +especially for the applied math +concentrators + + align:start position:0% +concentrators + + + align:start position:0% +concentrators +um going going straight to the + + align:start position:0% +um going going straight to the + + + align:start position:0% +um going going straight to the +conclusion your entire syllabus was + + align:start position:0% +conclusion your entire syllabus was + + + align:start position:0% +conclusion your entire syllabus was +generated at Cambridge University that's + + align:start position:0% +generated at Cambridge University that's + + + align:start position:0% +generated at Cambridge University that's +the conclusion so anyway here's the uh + + align:start position:0% +the conclusion so anyway here's the uh + + + align:start position:0% +the conclusion so anyway here's the uh +here's the story so um back in the 19th + + align:start position:0% +here's the story so um back in the 19th + + + align:start position:0% +here's the story so um back in the 19th +century the um the Cambridge Mathematics + + align:start position:0% +century the um the Cambridge Mathematics + + + align:start position:0% +century the um the Cambridge Mathematics +degree the undergraduate mathematics + + align:start position:0% +degree the undergraduate mathematics + + + align:start position:0% +degree the undergraduate mathematics +degree uh was the most um prestigious + + align:start position:0% +degree uh was the most um prestigious + + + align:start position:0% +degree uh was the most um prestigious +degree in the world in fact it was + + align:start position:0% +degree in the world in fact it was + + + align:start position:0% +degree in the world in fact it was +actually the the first + + align:start position:0% +actually the the first + + + align:start position:0% +actually the the first +it was the first undergraduate degree + + align:start position:0% +it was the first undergraduate degree + + + align:start position:0% +it was the first undergraduate degree +with the written + + align:start position:0% +with the written + + + align:start position:0% +with the written +examination it was Cambridge Mathematics + + align:start position:0% +examination it was Cambridge Mathematics + + + align:start position:0% +examination it was Cambridge Mathematics +so they have a lot to you know lot to be + + align:start position:0% +so they have a lot to you know lot to be + + + align:start position:0% +so they have a lot to you know lot to be +responsible for um and each year people + + align:start position:0% +responsible for um and each year people + + + align:start position:0% +responsible for um and each year people +took the exam and they were ranked and + + align:start position:0% +took the exam and they were ranked and + + + align:start position:0% +took the exam and they were ranked and +that ranking was published in the times + + align:start position:0% +that ranking was published in the times + + + align:start position:0% +that ranking was published in the times +of London so in the National newspaper + + align:start position:0% +of London so in the National newspaper + + + align:start position:0% +of London so in the National newspaper +um and the people who got first class + + align:start position:0% +um and the people who got first class + + + align:start position:0% +um and the people who got first class +degrees so summer degrees in Cambridge + + align:start position:0% +degrees so summer degrees in Cambridge + + + align:start position:0% +degrees so summer degrees in Cambridge +Mathematics were called Wranglers and + + align:start position:0% +Mathematics were called Wranglers and + + + align:start position:0% +Mathematics were called Wranglers and +still are called Wranglers actually and + + align:start position:0% +still are called Wranglers actually and + + + align:start position:0% +still are called Wranglers actually and +the reason they're called Wranglers was + + align:start position:0% +the reason they're called Wranglers was + + + align:start position:0% +the reason they're called Wranglers was +from way back in the 17th century where + + align:start position:0% +from way back in the 17th century where + + + align:start position:0% +from way back in the 17th century where +before they had exams or the 18th + + align:start position:0% +before they had exams or the 18th + + + align:start position:0% +before they had exams or the 18th +century I should say before they had + + align:start position:0% +century I should say before they had + + + align:start position:0% +century I should say before they had +exams instead of writing down exam you'd + + align:start position:0% +exams instead of writing down exam you'd + + + align:start position:0% +exams instead of writing down exam you'd +have to argue or dispute or Wrangle with + + align:start position:0% +have to argue or dispute or Wrangle with + + + align:start position:0% +have to argue or dispute or Wrangle with +your professor to get to pass the the + + align:start position:0% +your professor to get to pass the the + + + align:start position:0% +your professor to get to pass the the +class so that that's where Wrangle comes + + align:start position:0% +class so that that's where Wrangle comes + + + align:start position:0% +class so that that's where Wrangle comes +from so these these um uh people who got + + align:start position:0% +from so these these um uh people who got + + + align:start position:0% +from so these these um uh people who got +the first class degree called Wranglers + + align:start position:0% +the first class degree called Wranglers + + + align:start position:0% +the first class degree called Wranglers +and they are ranked and basically the + + align:start position:0% +and they are ranked and basically the + + + align:start position:0% +and they are ranked and basically the +the senior Wrangler was um a very famous + + align:start position:0% +the senior Wrangler was um a very famous + + + align:start position:0% +the senior Wrangler was um a very famous +person in the UK in the 19th century and + + align:start position:0% +person in the UK in the 19th century and + + + align:start position:0% +person in the UK in the 19th century and +a lot of them turned out to be quite + + align:start position:0% +a lot of them turned out to be quite + + + align:start position:0% +a lot of them turned out to be quite +successful so here are here are a few + + align:start position:0% +successful so here are here are a few + + + align:start position:0% +successful so here are here are a few +few wrangles I just U got this + + align:start position:0% +few wrangles I just U got this + + + align:start position:0% +few wrangles I just U got this +one I can't reach that there can I so + + align:start position:0% +one I can't reach that there can I so + + + align:start position:0% +one I can't reach that there can I so +some of them you might you might + + align:start position:0% +some of them you might you might + + + align:start position:0% +some of them you might you might +recognize and then I just wanted to tell + + align:start position:0% +recognize and then I just wanted to tell + + + align:start position:0% +recognize and then I just wanted to tell +you a quick story about the uh one of + + align:start position:0% + + + + align:start position:0% + +them okay so um let's start so + + align:start position:0% +them okay so um let's start so + + + align:start position:0% +them okay so um let's start so +1841 senior angler was uh George Stokes + + align:start position:0% +1841 senior angler was uh George Stokes + + + align:start position:0% +1841 senior angler was uh George Stokes +so basically fluid dynamics the whole + + align:start position:0% +so basically fluid dynamics the whole + + + align:start position:0% +so basically fluid dynamics the whole +the fluid dynamics that's George Stokes + + align:start position:0% +the fluid dynamics that's George Stokes + + + align:start position:0% +the fluid dynamics that's George Stokes +um 18 + + align:start position:0% + + + + align:start position:0% + +54 uh second Wrangler this is this is + + align:start position:0% +54 uh second Wrangler this is this is + + + align:start position:0% +54 uh second Wrangler this is this is +who was the first Wrangler second + + align:start position:0% +who was the first Wrangler second + + + align:start position:0% +who was the first Wrangler second +Wrangler was James Maxwell so + + align:start position:0% +Wrangler was James Maxwell so + + + align:start position:0% +Wrangler was James Maxwell so +electrodynamics Maxwell equations he was + + align:start position:0% +electrodynamics Maxwell equations he was + + + align:start position:0% +electrodynamics Maxwell equations he was +the second I mean I can't I can't quite + + align:start position:0% +the second I mean I can't I can't quite + + + align:start position:0% +the second I mean I can't I can't quite +work out who was who was the first um + + align:start position:0% +work out who was who was the first um + + + align:start position:0% +work out who was who was the first um +1880 the second Wrangler was uh JJ + + align:start position:0% +1880 the second Wrangler was uh JJ + + + align:start position:0% +1880 the second Wrangler was uh JJ +Thompson so electrons Atomic physics + + align:start position:0% +Thompson so electrons Atomic physics + + + align:start position:0% +Thompson so electrons Atomic physics +that comes out of he was only + + align:start position:0% +that comes out of he was only + + + align:start position:0% +that comes out of he was only +second um 1865 senior r Lord Raley so he + + align:start position:0% +second um 1865 senior r Lord Raley so he + + + align:start position:0% +second um 1865 senior r Lord Raley so he +was the uh you know the sky is + + align:start position:0% +was the uh you know the sky is + + + align:start position:0% +was the uh you know the sky is +blue + + align:start position:0% +blue + + + align:start position:0% +blue +um he was first okay so they're pretty + + align:start position:0% +um he was first okay so they're pretty + + + align:start position:0% +um he was first okay so they're pretty +they're a pretty pretty good Bunch um so + + align:start position:0% +they're a pretty pretty good Bunch um so + + + align:start position:0% +they're a pretty pretty good Bunch um so +the best the best the story the best + + align:start position:0% +the best the best the story the best + + + align:start position:0% +the best the best the story the best +story 1845 and going back uh the the + + align:start position:0% +story 1845 and going back uh the the + + + align:start position:0% +story 1845 and going back uh the the +second Wrangler was Lord + + align:start position:0% +second Wrangler was Lord + + + align:start position:0% +second Wrangler was Lord +Kelvin so absolute zero amongst other + + align:start position:0% +Kelvin so absolute zero amongst other + + + align:start position:0% +Kelvin so absolute zero amongst other +things of course but yeah absolute zero + + align:start position:0% +things of course but yeah absolute zero + + + align:start position:0% +things of course but yeah absolute zero +he was second Wrangler and the great + + align:start position:0% +he was second Wrangler and the great + + + align:start position:0% +he was second Wrangler and the great +story about him he was he was the most + + align:start position:0% +story about him he was he was the most + + + align:start position:0% +story about him he was he was the most +talented mathematician of his of the + + align:start position:0% +talented mathematician of his of the + + + align:start position:0% +talented mathematician of his of the +decade + + align:start position:0% +decade + + + align:start position:0% +decade +and it was such a lock for senior angler + + align:start position:0% +and it was such a lock for senior angler + + + align:start position:0% +and it was such a lock for senior angler +that and I actually read the biography + + align:start position:0% +that and I actually read the biography + + + align:start position:0% +that and I actually read the biography +so this is a sort of true statement that + + align:start position:0% +so this is a sort of true statement that + + + align:start position:0% +so this is a sort of true statement that +he sent his servant to the Senate house + + align:start position:0% +he sent his servant to the Senate house + + + align:start position:0% +he sent his servant to the Senate house +where these things are being read out + + align:start position:0% +where these things are being read out + + + align:start position:0% +where these things are being read out +and with a request tell me who is second + + align:start position:0% +and with a request tell me who is second + + + align:start position:0% +and with a request tell me who is second +Wrangler and the servant came back and + + align:start position:0% +Wrangler and the servant came back and + + + align:start position:0% +Wrangler and the servant came back and +said you sir and uh because he was he he + + align:start position:0% +said you sir and uh because he was he he + + + align:start position:0% +said you sir and uh because he was he he +was such a lock to be uh first Wrangler + + align:start position:0% +was such a lock to be uh first Wrangler + + + align:start position:0% +was such a lock to be uh first Wrangler +and in fact what happened was the + + align:start position:0% +and in fact what happened was the + + + align:start position:0% +and in fact what happened was the +question on the mathematical + + align:start position:0% +question on the mathematical + + + align:start position:0% +question on the mathematical +exam was a theorem that he had proved + + align:start position:0% +exam was a theorem that he had proved + + + align:start position:0% +exam was a theorem that he had proved +two years before in the Cambridge + + align:start position:0% +two years before in the Cambridge + + + align:start position:0% +two years before in the Cambridge +mathematical Jour mathematical Journal + + align:start position:0% +mathematical Jour mathematical Journal + + + align:start position:0% +mathematical Jour mathematical Journal +so it's his theorem was set on the exam + + align:start position:0% +so it's his theorem was set on the exam + + + align:start position:0% +so it's his theorem was set on the exam +but of course he had not memorized it so + + align:start position:0% +but of course he had not memorized it so + + + align:start position:0% +but of course he had not memorized it so +he had to reprove it whereas the person + + align:start position:0% +he had to reprove it whereas the person + + + align:start position:0% +he had to reprove it whereas the person +who became senior Wrangler had memorized + + align:start position:0% +who became senior Wrangler had memorized + + + align:start position:0% +who became senior Wrangler had memorized +the proof and was able to regenerate it + + align:start position:0% +the proof and was able to regenerate it + + + align:start position:0% +the proof and was able to regenerate it +and in those days there was a lot of + + align:start position:0% +and in those days there was a lot of + + + align:start position:0% +and in those days there was a lot of +cramming to be done in these exams so + + align:start position:0% +cramming to be done in these exams so + + + align:start position:0% +cramming to be done in these exams so +the guy who um Steven Parkinson was + + align:start position:0% +the guy who um Steven Parkinson was + + + align:start position:0% +the guy who um Steven Parkinson was +senior Wrangler he went on to be F FRS + + align:start position:0% +senior Wrangler he went on to be F FRS + + + align:start position:0% +senior Wrangler he went on to be F FRS +and eminent but so he wasn't uh so + + align:start position:0% +and eminent but so he wasn't uh so + + + align:start position:0% +and eminent but so he wasn't uh so +anyway so these are so here you go + + align:start position:0% +anyway so these are so here you go + + + align:start position:0% +anyway so these are so here you go +here's the applied math syllabus um + + align:start position:0% +here's the applied math syllabus um + + + align:start position:0% +here's the applied math syllabus um +here's a couple of other ones which I + + align:start position:0% +here's a couple of other ones which I + + + align:start position:0% +here's a couple of other ones which I +really like so in + + align:start position:0% +really like so in + + + align:start position:0% +really like so in +1904 John Mayar + + align:start position:0% +1904 John Mayar + + + align:start position:0% +1904 John Mayar +KES was a 12th Wrangler now I can tell + + align:start position:0% +KES was a 12th Wrangler now I can tell + + + align:start position:0% +KES was a 12th Wrangler now I can tell +the story either way depending on + + align:start position:0% +the story either way depending on + + + align:start position:0% +the story either way depending on +whether I'm in an audience of economists + + align:start position:0% +whether I'm in an audience of economists + + + align:start position:0% +whether I'm in an audience of economists +or audience of mathematicians it since + + align:start position:0% +or audience of mathematicians it since + + + align:start position:0% +or audience of mathematicians it since +I'm in an audience of mathematicians I + + align:start position:0% +I'm in an audience of mathematicians I + + + align:start position:0% +I'm in an audience of mathematicians I +like to say look the greatest Economist + + align:start position:0% +like to say look the greatest Economist + + + align:start position:0% +like to say look the greatest Economist +he was so poor at mathematics he only + + align:start position:0% +he was so poor at mathematics he only + + + align:start position:0% +he was so poor at mathematics he only +managed to be 12th Wrangler they're 11th + + align:start position:0% +managed to be 12th Wrangler they're 11th + + + align:start position:0% +managed to be 12th Wrangler they're 11th +better mathematicians in the UK in that + + align:start position:0% +better mathematicians in the UK in that + + + align:start position:0% +better mathematicians in the UK in that +year so he was obviously not not not + + align:start position:0% +year so he was obviously not not not + + + align:start position:0% +year so he was obviously not not not +that great if I was talking to Economist + + align:start position:0% +that great if I was talking to Economist + + + align:start position:0% +that great if I was talking to Economist +would say this guy was so brilliant that + + align:start position:0% +would say this guy was so brilliant that + + + align:start position:0% +would say this guy was so brilliant that +his main field was economics and yet as + + align:start position:0% +his main field was economics and yet as + + + align:start position:0% +his main field was economics and yet as +part-time he was able to be the 12th + + align:start position:0% +part-time he was able to be the 12th + + + align:start position:0% +part-time he was able to be the 12th +best mathematician in the UK so um + + align:start position:0% +best mathematician in the UK so um + + + align:start position:0% +best mathematician in the UK so um +anyway all right so the last one I + + align:start position:0% +anyway all right so the last one I + + + align:start position:0% +anyway all right so the last one I +wanted to talk about + + align:start position:0% +wanted to talk about + + + align:start position:0% +wanted to talk about +1879 all right here's a here's a um + + align:start position:0% +1879 all right here's a here's a um + + + align:start position:0% +1879 all right here's a here's a um +here's a quiz this one you have to have + + align:start position:0% +here's a quiz this one you have to have + + + align:start position:0% +here's a quiz this one you have to have +some answers for okay so um + + align:start position:0% +some answers for okay so um + + + align:start position:0% +some answers for okay so um +198 something I can't remember what it + + align:start position:0% +198 something I can't remember what it + + + align:start position:0% +198 something I can't remember what it +is okay so here's one here's two here's + + align:start position:0% +is okay so here's one here's two here's + + + align:start position:0% +is okay so here's one here's two here's +three right I'm going to give you one + + align:start position:0% +three right I'm going to give you one + + + align:start position:0% +three right I'm going to give you one +and two you got to in three right you're + + align:start position:0% +and two you got to in three right you're + + + align:start position:0% +and two you got to in three right you're +probably not going to be able to get + + align:start position:0% +probably not going to be able to get + + + align:start position:0% +probably not going to be able to get +this one yet but anyway so this is uh uh + + align:start position:0% +this one yet but anyway so this is uh uh + + + align:start position:0% +this one yet but anyway so this is uh uh +Andrew + + align:start position:0% +Andrew + + + align:start position:0% +Andrew +Allen senior Wrangler uh George Walker + + align:start position:0% +Allen senior Wrangler uh George Walker + + + align:start position:0% +Allen senior Wrangler uh George Walker +second + + align:start position:0% +second + + + align:start position:0% +second +Wrangler and number three the question + + align:start position:0% +Wrangler and number three the question + + + align:start position:0% +Wrangler and number three the question +okay so that's that's a question uh 1980 + + align:start position:0% +okay so that's that's a question uh 1980 + + + align:start position:0% +okay so that's that's a question uh 1980 +uh uh hakeim + + align:start position:0% + + + + align:start position:0% + +Alan uh s + + align:start position:0% + + + + align:start position:0% + +Boe question mark okay who's question + + align:start position:0% + + + + align:start position:0% + +mark do we know which sport these people + + align:start position:0% +mark do we know which sport these people + + + align:start position:0% +mark do we know which sport these people +are + + align:start position:0% +are + + + align:start position:0% +are +play that yes right there you go that's + + align:start position:0% +play that yes right there you go that's + + + align:start position:0% +play that yes right there you go that's +Michael Jordan exactly I think you know + + align:start position:0% +Michael Jordan exactly I think you know + + + align:start position:0% +Michael Jordan exactly I think you know +this is this a question could go on + + align:start position:0% +this is this a question could go on + + + align:start position:0% +this is this a question could go on +forever in the UK because they does so + + align:start position:0% +forever in the UK because they does so + + + align:start position:0% +forever in the UK because they does so +Michael Jordan famously was only picked + + align:start position:0% +Michael Jordan famously was only picked + + + align:start position:0% +Michael Jordan famously was only picked +third in the NBA draft in + + align:start position:0% +third in the NBA draft in + + + align:start position:0% +third in the NBA draft in +1984 was it four five something like + + align:start position:0% +1984 was it four five something like + + + align:start position:0% +1984 was it four five something like +that so now hakeim Al was actually + + align:start position:0% +that so now hakeim Al was actually + + + align:start position:0% +that so now hakeim Al was actually +pretty good but is a total bust so + + align:start position:0% +pretty good but is a total bust so + + + align:start position:0% +pretty good but is a total bust so +but he was third so in 1879 and the came + + align:start position:0% +but he was third so in 1879 and the came + + + align:start position:0% +but he was third so in 1879 and the came +mathematics tripos these two people + + align:start position:0% +mathematics tripos these two people + + + align:start position:0% +mathematics tripos these two people +you've never heard of were first and + + align:start position:0% +you've never heard of were first and + + + align:start position:0% +you've never heard of were first and +second and the person who came third + + align:start position:0% +second and the person who came third + + + align:start position:0% +second and the person who came third +you've probably heard of I this is more + + align:start position:0% +you've probably heard of I this is more + + + align:start position:0% +you've probably heard of I this is more +of a statistics thing um people know + + align:start position:0% +of a statistics thing um people know + + + align:start position:0% +of a statistics thing um people know +about + + align:start position:0% +about + + + align:start position:0% +about +correlation what's the correlation who's + + align:start position:0% +correlation what's the correlation who's + + + align:start position:0% +correlation what's the correlation who's +correlation coefficient named + + align:start position:0% +correlation coefficient named + + + align:start position:0% +correlation coefficient named +after Pearson very good k k Pearson so + + align:start position:0% +after Pearson very good k k Pearson so + + + align:start position:0% +after Pearson very good k k Pearson so +so K + + align:start position:0% +so K + + + align:start position:0% +so K +Pearson was the third Wrangler in 1879 + + align:start position:0% +Pearson was the third Wrangler in 1879 + + + align:start position:0% +Pearson was the third Wrangler in 1879 +and the founder of Statistics he founded + + align:start position:0% +and the founder of Statistics he founded + + + align:start position:0% +and the founder of Statistics he founded +the first ever statistics Department and + + align:start position:0% +the first ever statistics Department and + + + align:start position:0% +the first ever statistics Department and +um obviously invented correlation with + + align:start position:0% +um obviously invented correlation with + + + align:start position:0% +um obviously invented correlation with +golden golden Pearson so anyway it's + + align:start position:0% +golden golden Pearson so anyway it's + + + align:start position:0% +golden golden Pearson so anyway it's +only the third Wrangler and + + align:start position:0% +only the third Wrangler and + + + align:start position:0% +only the third Wrangler and +unfortunately these people have very + + align:start position:0% +unfortunately these people have very + + + align:start position:0% +unfortunately these people have very +common name so I have no idea what they + + align:start position:0% +common name so I have no idea what they + + + align:start position:0% +common name so I have no idea what they +went on to do right Google these people + + align:start position:0% +went on to do right Google these people + + + align:start position:0% +went on to do right Google these people +is not not not very effective anyway so + + align:start position:0% +is not not not very effective anyway so + + + align:start position:0% +is not not not very effective anyway so +that's the uh that's the story of uh + + align:start position:0% +that's the uh that's the story of uh + + + align:start position:0% +that's the uh that's the story of uh +Cambridge Cambridge Mathematics lot of + + align:start position:0% +Cambridge Cambridge Mathematics lot of + + + align:start position:0% +Cambridge Cambridge Mathematics lot of +uh lots of good good stuff + + align:start position:0% + + + + align:start position:0% + +all right so um last half hour I just + + align:start position:0% +all right so um last half hour I just + + + align:start position:0% +all right so um last half hour I just +want to go the other + + align:start position:0% +want to go the other + + + align:start position:0% +want to go the other +way um + + align:start position:0% +way um + + + align:start position:0% +way um +from where's my page three okay so the + + align:start position:0% +from where's my page three okay so the + + + align:start position:0% +from where's my page three okay so the +other way we went from option prices to + + align:start position:0% +other way we went from option prices to + + + align:start position:0% +other way we went from option prices to +probability let's go from probability to + + align:start position:0% +probability let's go from probability to + + + align:start position:0% +probability let's go from probability to +option price we sort of already have + + align:start position:0% +option price we sort of already have + + + align:start position:0% +option price we sort of already have +actually this is what the fundamental + + align:start position:0% +actually this is what the fundamental + + + align:start position:0% +actually this is what the fundamental +theorem does if we're thinking if we + + align:start position:0% +theorem does if we're thinking if we + + + align:start position:0% +theorem does if we're thinking if we +let's take on trust that the fundamental + + align:start position:0% +let's take on trust that the fundamental + + + align:start position:0% +let's take on trust that the fundamental +theorem holds namely option prices today + + align:start position:0% +theorem holds namely option prices today + + + align:start position:0% +theorem holds namely option prices today +are the discounted expected + + align:start position:0% +are the discounted expected + + + align:start position:0% +are the discounted expected +payout at maturity okay let take that on + + align:start position:0% +payout at maturity okay let take that on + + + align:start position:0% +payout at maturity okay let take that on +on trust then we're going from + + align:start position:0% +on trust then we're going from + + + align:start position:0% +on trust then we're going from +probability distribution to option price + + align:start position:0% +probability distribution to option price + + + align:start position:0% +probability distribution to option price +in the following way so let's actually + + align:start position:0% +in the following way so let's actually + + + align:start position:0% +in the following way so let's actually +State the the fundamental + + align:start position:0% +State the the fundamental + + + align:start position:0% +State the the fundamental +theorem + + align:start position:0% + + + + align:start position:0% + +ft okay so + + align:start position:0% +ft okay so + + + align:start position:0% +ft okay so +um so I'm going to General derivative D + + align:start position:0% +um so I'm going to General derivative D + + + align:start position:0% +um so I'm going to General derivative D +it's D digital D derivative it's um so a + + align:start position:0% + + + + align:start position:0% + +derivative with pay + + align:start position:0% + + + + align:start position:0% + +at T So this could be the digital payout + + align:start position:0% +at T So this could be the digital payout + + + align:start position:0% +at T So this could be the digital payout +it could be the call option payout it + + align:start position:0% +it could be the call option payout it + + + align:start position:0% +it could be the call option payout it +could be one um and + + align:start position:0% + + + + align:start position:0% + +price + + align:start position:0% +price + + + align:start position:0% +price +right okay so often we we actually think + + align:start position:0% +right okay so often we we actually think + + + align:start position:0% +right okay so often we we actually think +about the payout function is just a + + align:start position:0% +about the payout function is just a + + + align:start position:0% +about the payout function is just a +simple function of the the stock price + + align:start position:0% +simple function of the the stock price + + + align:start position:0% +simple function of the the stock price +um but this notation is useful when we + + align:start position:0% +um but this notation is useful when we + + + align:start position:0% +um but this notation is useful when we +think about the prices being marting + + align:start position:0% +think about the prices being marting + + + align:start position:0% +think about the prices being marting +Gales okay + + align:start position:0% +Gales okay + + + align:start position:0% +Gales okay +then what is ftap um + + align:start position:0% +then what is ftap um + + + align:start position:0% +then what is ftap um +D the ratio of the price to the zero + + align:start position:0% +D the ratio of the price to the zero + + + align:start position:0% +D the ratio of the price to the zero +coupon + + align:start position:0% +coupon + + + align:start position:0% +coupon +bond is equal to is a Martingale in + + align:start position:0% +bond is equal to is a Martingale in + + + align:start position:0% +bond is equal to is a Martingale in +other words there expected value under + + align:start position:0% +other words there expected value under + + + align:start position:0% +other words there expected value under +the special distribution risk neutral + + align:start position:0% +the special distribution risk neutral + + + align:start position:0% +the special distribution risk neutral +distribution of the payout at maturity + + align:start position:0% + + + + align:start position:0% + +and to your point it's conditional on St + + align:start position:0% +and to your point it's conditional on St + + + align:start position:0% +and to your point it's conditional on St +so this is the proper statement so this + + align:start position:0% +so this is the proper statement so this + + + align:start position:0% +so this is the proper statement so this +is the fundamental theorem of asset + + align:start position:0% +is the fundamental theorem of asset + + + align:start position:0% +is the fundamental theorem of asset +prices in words it's saying this ratio + + align:start position:0% +prices in words it's saying this ratio + + + align:start position:0% +prices in words it's saying this ratio +is a Martingale with respect to the + + align:start position:0% +is a Martingale with respect to the + + + align:start position:0% +is a Martingale with respect to the +stock price under the risk neutral + + align:start position:0% +stock price under the risk neutral + + + align:start position:0% +stock price under the risk neutral +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +okay okay that's the statement of the + + align:start position:0% +okay okay that's the statement of the + + + align:start position:0% +okay okay that's the statement of the +fundamental theorem this is actually + + align:start position:0% +fundamental theorem this is actually + + + align:start position:0% +fundamental theorem this is actually +rather neat to prove in the binomial + + align:start position:0% +rather neat to prove in the binomial + + + align:start position:0% +rather neat to prove in the binomial +tree twostep two- State world is very + + align:start position:0% +tree twostep two- State world is very + + + align:start position:0% +tree twostep two- State world is very +very difficult to prove in continuous + + align:start position:0% +very difficult to prove in continuous + + + align:start position:0% +very difficult to prove in continuous +time this is uh Harrison and creps in + + align:start position:0% +time this is uh Harrison and creps in + + + align:start position:0% +time this is uh Harrison and creps in +1979 it's a proof that you know however + + align:start position:0% +1979 it's a proof that you know however + + + align:start position:0% +1979 it's a proof that you know however +many times you look at it you're only + + align:start position:0% +many times you look at it you're only + + + align:start position:0% +many times you look at it you're only +probably going to get through the two or + + align:start position:0% +probably going to get through the two or + + + align:start position:0% +probably going to get through the two or +three pages before thinking okay that's + + align:start position:0% +three pages before thinking okay that's + + + align:start position:0% +three pages before thinking okay that's +hard but it's it was done sorry okay so + + align:start position:0% +hard but it's it was done sorry okay so + + + align:start position:0% +hard but it's it was done sorry okay so +this is um you can imagine continuous + + align:start position:0% +this is um you can imagine continuous + + + align:start position:0% +this is um you can imagine continuous +time infinite amount of trading + + align:start position:0% +time infinite amount of trading + + + align:start position:0% +time infinite amount of trading +different states of the world it's very + + align:start position:0% +different states of the world it's very + + + align:start position:0% +different states of the world it's very +okay so now this of course is + + align:start position:0% +okay so now this of course is + + + align:start position:0% +okay so now this of course is +one okay um and this can come up this is + + align:start position:0% +one okay um and this can come up this is + + + align:start position:0% +one okay um and this can come up this is +these are known at time Little T so if + + align:start position:0% +these are known at time Little T so if + + + align:start position:0% +these are known at time Little T so if +I'm thinking at if I'm at current time + + align:start position:0% +I'm thinking at if I'm at current time + + + align:start position:0% +I'm thinking at if I'm at current time +Little T therefore the derivative + + align:start position:0% +Little T therefore the derivative + + + align:start position:0% +Little T therefore the derivative +price is what we had + + align:start position:0% +price is what we had + + + align:start position:0% +price is what we had +before the expected + + align:start position:0% + + + + align:start position:0% + +payout okay so this is rather nice nice + + align:start position:0% +payout okay so this is rather nice nice + + + align:start position:0% +payout okay so this is rather nice nice +expression and now we can actually just + + align:start position:0% +expression and now we can actually just + + + align:start position:0% +expression and now we can actually just +write down what this is this is the + + align:start position:0% +write down what this is this is the + + + align:start position:0% +write down what this is this is the +expected value of a function of a random + + align:start position:0% +expected value of a function of a random + + + align:start position:0% +expected value of a function of a random +variable okay so this is + + align:start position:0% +variable okay so this is + + + align:start position:0% +variable okay so this is +just the + + align:start position:0% +just the + + + align:start position:0% +just the +integral of G of x + + align:start position:0% +integral of G of x + + + align:start position:0% +integral of G of x +f of + + align:start position:0% +f of + + + align:start position:0% +f of +x DX where this is the density of the + + align:start position:0% +x DX where this is the density of the + + + align:start position:0% +x DX where this is the density of the +random variable at time capital D + + align:start position:0% +random variable at time capital D + + + align:start position:0% +random variable at time capital D +condition one being at St so this + + align:start position:0% +condition one being at St so this + + + align:start position:0% +condition one being at St so this +conditional density okay so this is a + + align:start position:0% +conditional density okay so this is a + + + align:start position:0% +conditional density okay so this is a +restatement of um the fundamental + + align:start position:0% +restatement of um the fundamental + + + align:start position:0% +restatement of um the fundamental +theorem so this is essentially the + + align:start position:0% +theorem so this is essentially the + + + align:start position:0% +theorem so this is essentially the +fundamental theorem and this is a + + align:start position:0% +fundamental theorem and this is a + + + align:start position:0% +fundamental theorem and this is a +intuition made good or intuition made + + align:start position:0% +intuition made good or intuition made + + + align:start position:0% +intuition made good or intuition made +real expected + + align:start position:0% +real expected + + + align:start position:0% +real expected +payouts okay this is um sometimes called + + align:start position:0% +payouts okay this is um sometimes called + + + align:start position:0% +payouts okay this is um sometimes called +Lotus the of the unconscious statistici + + align:start position:0% +Lotus the of the unconscious statistici + + + align:start position:0% +Lotus the of the unconscious statistici +it's just that the expected value of G + + align:start position:0% +it's just that the expected value of G + + + align:start position:0% +it's just that the expected value of G +ofx is integral G of x f ofx that's not + + align:start position:0% +ofx is integral G of x f ofx that's not + + + align:start position:0% +ofx is integral G of x f ofx that's not +immediate from the definition of + + align:start position:0% +immediate from the definition of + + + align:start position:0% +immediate from the definition of +expected value you should really work + + align:start position:0% +expected value you should really work + + + align:start position:0% +expected value you should really work +out the density of G of X right and then + + align:start position:0% +out the density of G of X right and then + + + align:start position:0% +out the density of G of X right and then +integral of x the density of G of X DX + + align:start position:0% +integral of x the density of G of X DX + + + align:start position:0% +integral of x the density of G of X DX +but it turns out to be this okay so + + align:start position:0% +but it turns out to be this okay so + + + align:start position:0% +but it turns out to be this okay so +that's a really nice nice result okay so + + align:start position:0% +that's a really nice nice result okay so + + + align:start position:0% +that's a really nice nice result okay so +here is now + + align:start position:0% +here is now + + + align:start position:0% +here is now +our way of going from density to price + + align:start position:0% +our way of going from density to price + + + align:start position:0% +our way of going from density to price +if I put in the call + + align:start position:0% +if I put in the call + + + align:start position:0% +if I put in the call +option payout for G and I have the + + align:start position:0% +option payout for G and I have the + + + align:start position:0% +option payout for G and I have the +density I can then derive the price C + + align:start position:0% +density I can then derive the price C + + + align:start position:0% +density I can then derive the price C +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you like the way I go from density + + align:start position:0% +so if you like the way I go from density + + + align:start position:0% +so if you like the way I go from density +to or probability distribution to option + + align:start position:0% +to or probability distribution to option + + + align:start position:0% +to or probability distribution to option +price is exactly the fundamental theorem + + align:start position:0% +price is exactly the fundamental theorem + + + align:start position:0% +price is exactly the fundamental theorem +or the root I take is a fundamental + + align:start position:0% + + + + align:start position:0% + +theorem okay so ftap fundamental theorem + + align:start position:0% +theorem okay so ftap fundamental theorem + + + align:start position:0% +theorem okay so ftap fundamental theorem +of asset pricing means I can go from the + + align:start position:0% +of asset pricing means I can go from the + + + align:start position:0% +of asset pricing means I can go from the +probability density to the price of the + + align:start position:0% +probability density to the price of the + + + align:start position:0% +probability density to the price of the +derivative for any derivative + + align:start position:0% +derivative for any derivative + + + align:start position:0% +derivative for any derivative +okay + + align:start position:0% +okay + + + align:start position:0% +okay +right okay so now we can go either way + + align:start position:0% +right okay so now we can go either way + + + align:start position:0% +right okay so now we can go either way +density to derivative or call Price to + + align:start position:0% +density to derivative or call Price to + + + align:start position:0% +density to derivative or call Price to +density you might say well hang on a sec + + align:start position:0% +density you might say well hang on a sec + + + align:start position:0% +density you might say well hang on a sec +we've only gone from we need the core + + align:start position:0% +we've only gone from we need the core + + + align:start position:0% +we've only gone from we need the core +prices to get the density well of course + + align:start position:0% +prices to get the density well of course + + + align:start position:0% +prices to get the density well of course +you know we can + + align:start position:0% +you know we can + + + align:start position:0% +you know we can +go via an intermediate step right so to + + align:start position:0% +go via an intermediate step right so to + + + align:start position:0% +go via an intermediate step right so to +get from the core price to these an + + align:start position:0% +get from the core price to these an + + + align:start position:0% +get from the core price to these an +arbitrary derivative price I just go via + + align:start position:0% +arbitrary derivative price I just go via + + + align:start position:0% +arbitrary derivative price I just go via +the density right so in + + align:start position:0% + + + + align:start position:0% + +particular this is reating + + align:start position:0% + + + + align:start position:0% + +knowledge of all the C + + align:start position:0% + + + + align:start position:0% + +prices okay for all + + align:start position:0% +prices okay for all + + + align:start position:0% +prices okay for all +K okay determines + + align:start position:0% + + + + align:start position:0% + +this derivative pair for any + + align:start position:0% + + + + align:start position:0% + +G okay so if I know all calls I know the + + align:start position:0% +G okay so if I know all calls I know the + + + align:start position:0% +G okay so if I know all calls I know the +density and then if I know the density I + + align:start position:0% +density and then if I know the density I + + + align:start position:0% +density and then if I know the density I +know an arbitary derivative price okay + + align:start position:0% +know an arbitary derivative price okay + + + align:start position:0% +know an arbitary derivative price okay +it's obvious as we state it here but + + align:start position:0% +it's obvious as we state it here but + + + align:start position:0% +it's obvious as we state it here but +what this is saying is the call options + + align:start position:0% +what this is saying is the call options + + + align:start position:0% +what this is saying is the call options +often introduces this why are they + + align:start position:0% +often introduces this why are they + + + align:start position:0% +often introduces this why are they +important are the spanning set right of + + align:start position:0% +important are the spanning set right of + + + align:start position:0% +important are the spanning set right of +all derivative prices so calls + + align:start position:0% +all derivative prices so calls + + + align:start position:0% +all derivative prices so calls +span call prices + + align:start position:0% +span call prices + + + align:start position:0% +span call prices +span span + + align:start position:0% +span span + + + align:start position:0% +span span +all all + + align:start position:0% + + + + align:start position:0% + +derivative prices and they're a + + align:start position:0% +derivative prices and they're a + + + align:start position:0% +derivative prices and they're a +particular type of derivative the ones + + align:start position:0% +particular type of derivative the ones + + + align:start position:0% +particular type of derivative the ones +that are + + align:start position:0% +that are + + + align:start position:0% +that are +determined um exactly by their payout at + + align:start position:0% +determined um exactly by their payout at + + + align:start position:0% +determined um exactly by their payout at +maturity right one can imagine other + + align:start position:0% +maturity right one can imagine other + + + align:start position:0% +maturity right one can imagine other +things that are function of the path or + + align:start position:0% +things that are function of the path or + + + align:start position:0% +things that are function of the path or +whatever but this is particular + + align:start position:0% +whatever but this is particular + + + align:start position:0% +whatever but this is particular +derivative price European derivative + + align:start position:0% +derivative price European derivative + + + align:start position:0% +derivative price European derivative +prices are + + align:start position:0% +prices are + + + align:start position:0% +prices are +determined by calls okay so that's kind + + align:start position:0% +determined by calls okay so that's kind + + + align:start position:0% +determined by calls okay so that's kind +of nice sort of obvious well well it's + + align:start position:0% +of nice sort of obvious well well it's + + + align:start position:0% +of nice sort of obvious well well it's +elegant there's are two ways there are + + align:start position:0% +elegant there's are two ways there are + + + align:start position:0% +elegant there's are two ways there are +two other ways of + + align:start position:0% +two other ways of + + + align:start position:0% +two other ways of +of looking at this though right if I + + align:start position:0% +of looking at this though right if I + + + align:start position:0% +of looking at this though right if I +think about my function + + align:start position:0% +think about my function + + + align:start position:0% +think about my function +G right so think about consider + + align:start position:0% +G right so think about consider + + + align:start position:0% +G right so think about consider +um function + + align:start position:0% + + + + align:start position:0% + +G okay so that that that determines my + + align:start position:0% +G okay so that that that determines my + + + align:start position:0% +G okay so that that that determines my +um derivative so it determines defines + + align:start position:0% +um derivative so it determines defines + + + align:start position:0% +um derivative so it determines defines +the derivative by its payout at maturity + + align:start position:0% +the derivative by its payout at maturity + + + align:start position:0% +the derivative by its payout at maturity +let's just graph it okay okay so it + + align:start position:0% +let's just graph it okay okay so it + + + align:start position:0% +let's just graph it okay okay so it +might look let's let's assume first it's + + align:start position:0% +might look let's let's assume first it's + + + align:start position:0% +might look let's let's assume first it's +piecewise linear right so it looks + + align:start position:0% + + + + align:start position:0% + +like right suppose this is this is + + align:start position:0% + + + + align:start position:0% + +G okay well you can kind of see I can + + align:start position:0% +G okay well you can kind of see I can + + + align:start position:0% +G okay well you can kind of see I can +replicate this portfolio or this option + + align:start position:0% +replicate this portfolio or this option + + + align:start position:0% +replicate this portfolio or this option +by a portfolio of calls in fact a linear + + align:start position:0% +by a portfolio of calls in fact a linear + + + align:start position:0% +by a portfolio of calls in fact a linear +combination of calls right I have no + + align:start position:0% +combination of calls right I have no + + + align:start position:0% +combination of calls right I have no +calls but if this is say + + align:start position:0% +calls but if this is say + + + align:start position:0% +calls but if this is say +K1 this is + + align:start position:0% +K1 this is + + + align:start position:0% +K1 this is +K2 + + align:start position:0% +K2 + + + align:start position:0% +K2 +K3 + + align:start position:0% +K3 + + + align:start position:0% +K3 +K4 K5 + + align:start position:0% +K4 K5 + + + align:start position:0% +K4 K5 +Etc okay you can see what the portfolio + + align:start position:0% +Etc okay you can see what the portfolio + + + align:start position:0% +Etc okay you can see what the portfolio +of calls will be in order to replicate + + align:start position:0% +of calls will be in order to replicate + + + align:start position:0% +of calls will be in order to replicate +this payout at maturity right it'll be a + + align:start position:0% +this payout at maturity right it'll be a + + + align:start position:0% +this payout at maturity right it'll be a +certain amount of calls with strike K1 + + align:start position:0% +certain amount of calls with strike K1 + + + align:start position:0% +certain amount of calls with strike K1 +so that the slope is Right minus a + + align:start position:0% +so that the slope is Right minus a + + + align:start position:0% +so that the slope is Right minus a +certain amount of K2 to get this slope + + align:start position:0% +certain amount of K2 to get this slope + + + align:start position:0% +certain amount of K2 to get this slope +plus a certain amount of K3 minus K4 + + align:start position:0% +plus a certain amount of K3 minus K4 + + + align:start position:0% +plus a certain amount of K3 minus K4 +minus K5 plus k6 Etc so in this case so + + align:start position:0% +minus K5 plus k6 Etc so in this case so + + + align:start position:0% +minus K5 plus k6 Etc so in this case so +a pie wise + + align:start position:0% + + + + align:start position:0% + +linear linear + + align:start position:0% +linear linear + + + align:start position:0% +linear linear +G + + align:start position:0% + + + + align:start position:0% + +replicating + + align:start position:0% +replicating + + + align:start position:0% +replicating +portfolio of + + align:start position:0% +portfolio of + + + align:start position:0% +portfolio of +calls is + + align:start position:0% +calls is + + + align:start position:0% +calls is +obvious + + align:start position:0% +obvious + + + align:start position:0% +obvious +okay all right so if I can replicate the + + align:start position:0% +okay all right so if I can replicate the + + + align:start position:0% +okay all right so if I can replicate the +payout exactly at maturity the price at + + align:start position:0% +payout exactly at maturity the price at + + + align:start position:0% +payout exactly at maturity the price at +time Little T of this derivative + + align:start position:0% +time Little T of this derivative + + + align:start position:0% +time Little T of this derivative +must be the price at Little T of the + + align:start position:0% +must be the price at Little T of the + + + align:start position:0% +must be the price at Little T of the +replicating + + align:start position:0% +replicating + + + align:start position:0% +replicating +portfolio that's actually + + align:start position:0% +portfolio that's actually + + + align:start position:0% +portfolio that's actually +a I do that early on in my class and of + + align:start position:0% +a I do that early on in my class and of + + + align:start position:0% +a I do that early on in my class and of +the 100 people Everyone say okay that's + + align:start position:0% +the 100 people Everyone say okay that's + + + align:start position:0% +the 100 people Everyone say okay that's +that makes sense and someone says does + + align:start position:0% +that makes sense and someone says does + + + align:start position:0% +that makes sense and someone says does +that always have to be the case and it's + + align:start position:0% +that always have to be the case and it's + + + align:start position:0% +that always have to be the case and it's +actually a really really good question + + align:start position:0% +actually a really really good question + + + align:start position:0% +actually a really really good question +now here I was about to just handwave + + align:start position:0% +now here I was about to just handwave + + + align:start position:0% +now here I was about to just handwave +over + + align:start position:0% +over + + + align:start position:0% +over +it is it the case that if I have one + + align:start position:0% +it is it the case that if I have one + + + align:start position:0% +it is it the case that if I have one +derivative contract with this payout at + + align:start position:0% +derivative contract with this payout at + + + align:start position:0% +derivative contract with this payout at +maturity okay and I have a linear + + align:start position:0% +maturity okay and I have a linear + + + align:start position:0% +maturity okay and I have a linear +combination of + + align:start position:0% +combination of + + + align:start position:0% +combination of +calls with the identical payout at + + align:start position:0% +calls with the identical payout at + + + align:start position:0% +calls with the identical payout at +maturity capital T must these two + + align:start position:0% +maturity capital T must these two + + + align:start position:0% +maturity capital T must these two +portfolios have the same value at Little + + align:start position:0% + + + + align:start position:0% + +T well one think so because it's right + + align:start position:0% +T well one think so because it's right + + + align:start position:0% +T well one think so because it's right +they're both the same at maturity so + + align:start position:0% +they're both the same at maturity so + + + align:start position:0% +they're both the same at maturity so +they must both be the same thing they're + + align:start position:0% +they must both be the same thing they're + + + align:start position:0% +they must both be the same thing they're +just constructed differently and the + + align:start position:0% +just constructed differently and the + + + align:start position:0% +just constructed differently and the +Assumption of no Arbitrage which is + + align:start position:0% +Assumption of no Arbitrage which is + + + align:start position:0% +Assumption of no Arbitrage which is +underpins everything in some sense what + + align:start position:0% +underpins everything in some sense what + + + align:start position:0% +underpins everything in some sense what +what we're doing would allow you to say + + align:start position:0% +what we're doing would allow you to say + + + align:start position:0% +what we're doing would allow you to say +yes indeed that is true right in fact + + align:start position:0% +yes indeed that is true right in fact + + + align:start position:0% +yes indeed that is true right in fact +it's actually the fundamental of Finance + + align:start position:0% +it's actually the fundamental of Finance + + + align:start position:0% +it's actually the fundamental of Finance +right if if two things are worth a + + align:start position:0% +right if if two things are worth a + + + align:start position:0% +right if if two things are worth a +dollar in a year's time they got to be + + align:start position:0% +dollar in a year's time they got to be + + + align:start position:0% +dollar in a year's time they got to be +worth the same today + + align:start position:0% +worth the same today + + + align:start position:0% +worth the same today +right that's what we're saying if they + + align:start position:0% +right that's what we're saying if they + + + align:start position:0% +right that's what we're saying if they +you can match the portfolio at T that is + + align:start position:0% +you can match the portfolio at T that is + + + align:start position:0% +you can match the portfolio at T that is +actually the definition + + align:start position:0% +actually the definition + + + align:start position:0% +actually the definition +of it follows immediately from no + + align:start position:0% +of it follows immediately from no + + + align:start position:0% +of it follows immediately from no +Arbitrage what has been + + align:start position:0% +Arbitrage what has been + + + align:start position:0% +Arbitrage what has been +interesting in finance especially since + + align:start position:0% +interesting in finance especially since + + + align:start position:0% +interesting in finance especially since +2008 is that that no arbit this + + align:start position:0% +2008 is that that no arbit this + + + align:start position:0% +2008 is that that no arbit this +assumption has broken down + + align:start position:0% +assumption has broken down + + + align:start position:0% +assumption has broken down +in other words I've hold I can hold a + + align:start position:0% +in other words I've hold I can hold a + + + align:start position:0% +in other words I've hold I can hold a +portfolio of things when aggregated have + + align:start position:0% +portfolio of things when aggregated have + + + align:start position:0% +portfolio of things when aggregated have +exactly this + + align:start position:0% +exactly this + + + align:start position:0% +exactly this +payout against an option with exactly + + align:start position:0% +payout against an option with exactly + + + align:start position:0% +payout against an option with exactly +this + + align:start position:0% +this + + + align:start position:0% +this +payout and be paid for + + align:start position:0% +payout and be paid for + + + align:start position:0% +payout and be paid for +that and this is actually really it's a + + align:start position:0% +that and this is actually really it's a + + + align:start position:0% +that and this is actually really it's a +very it's a very fascinating thing to + + align:start position:0% +very it's a very fascinating thing to + + + align:start position:0% +very it's a very fascinating thing to +think about actually the Dynamics of + + align:start position:0% +think about actually the Dynamics of + + + align:start position:0% +think about actually the Dynamics of +financial markets when Arbitrage can + + align:start position:0% +financial markets when Arbitrage can + + + align:start position:0% +financial markets when Arbitrage can +break down what is the main theme Here + + align:start position:0% +break down what is the main theme Here + + + align:start position:0% +break down what is the main theme Here +is that when capital t is a long way in + + align:start position:0% +is that when capital t is a long way in + + + align:start position:0% +is that when capital t is a long way in +the + + align:start position:0% +the + + + align:start position:0% +the +future 10 years 20 + + align:start position:0% +future 10 years 20 + + + align:start position:0% +future 10 years 20 +years there's nothing to stop the price + + align:start position:0% +years there's nothing to stop the price + + + align:start position:0% +years there's nothing to stop the price +of the option in the replicating + + align:start position:0% +of the option in the replicating + + + align:start position:0% +of the option in the replicating +portfolio going arbitrarily wide other + + align:start position:0% +portfolio going arbitrarily wide other + + + align:start position:0% +portfolio going arbitrarily wide other +than people believing that there has to + + align:start position:0% +than people believing that there has to + + + align:start position:0% +than people believing that there has to +be + + align:start position:0% + + + + align:start position:0% + +equal the only way that you can + + align:start position:0% +equal the only way that you can + + + align:start position:0% +equal the only way that you can +guarantee the two things to be equal is + + align:start position:0% +guarantee the two things to be equal is + + + align:start position:0% +guarantee the two things to be equal is +by holding it until capital T right for + + align:start position:0% +by holding it until capital T right for + + + align:start position:0% +by holding it until capital T right for +10 years for 20 years in the + + align:start position:0% +10 years for 20 years in the + + + align:start position:0% +10 years for 20 years in the +meantime those prices can move + + align:start position:0% +meantime those prices can move + + + align:start position:0% +meantime those prices can move +empirically they've been shown to move + + align:start position:0% +empirically they've been shown to move + + + align:start position:0% +empirically they've been shown to move +away from each other right so it's + + align:start position:0% +away from each other right so it's + + + align:start position:0% +away from each other right so it's +actually a of a deep economic question + + align:start position:0% +actually a of a deep economic question + + + align:start position:0% +actually a of a deep economic question +here it's like + + align:start position:0% +here it's like + + + align:start position:0% +here it's like +if if there is the presence of Arbitrage + + align:start position:0% +if if there is the presence of Arbitrage + + + align:start position:0% +if if there is the presence of Arbitrage +in the markets then that Arbitrage can + + align:start position:0% +in the markets then that Arbitrage can + + + align:start position:0% +in the markets then that Arbitrage can +be arbitrarily big I mean if because + + align:start position:0% +be arbitrarily big I mean if because + + + align:start position:0% +be arbitrarily big I mean if because +you're saying there aren't enough + + align:start position:0% +you're saying there aren't enough + + + align:start position:0% +you're saying there aren't enough +there's not enough capital or there's + + align:start position:0% +there's not enough capital or there's + + + align:start position:0% +there's not enough capital or there's +not enough risk capital for people to + + align:start position:0% +not enough risk capital for people to + + + align:start position:0% +not enough risk capital for people to +come in and say okay these two things + + align:start position:0% +come in and say okay these two things + + + align:start position:0% +come in and say okay these two things +have to be worth the same in 10 years + + align:start position:0% +have to be worth the same in 10 years + + + align:start position:0% +have to be worth the same in 10 years +time therefore I'm prepared to + + align:start position:0% +time therefore I'm prepared to + + + align:start position:0% +time therefore I'm prepared to +buy one a dollar cheaper than the other + + align:start position:0% +buy one a dollar cheaper than the other + + + align:start position:0% +buy one a dollar cheaper than the other +it's actually a question really of + + align:start position:0% +it's actually a question really of + + + align:start position:0% +it's actually a question really of +relevance to the Harvard endowment we're + + align:start position:0% +relevance to the Harvard endowment we're + + + align:start position:0% +relevance to the Harvard endowment we're +a long-term investor you say why doesn't + + align:start position:0% +a long-term investor you say why doesn't + + + align:start position:0% +a long-term investor you say why doesn't +the Harvard endowment if these two + + align:start position:0% +the Harvard endowment if these two + + + align:start position:0% +the Harvard endowment if these two +things are a dollar + + align:start position:0% +things are a dollar + + + align:start position:0% +things are a dollar +apart buy the thing that's dollar + + align:start position:0% +apart buy the thing that's dollar + + + align:start position:0% +apart buy the thing that's dollar +cheaper and just hold them for 10 years + + align:start position:0% +cheaper and just hold them for 10 years + + + align:start position:0% +cheaper and just hold them for 10 years +make the dollar Well we'd like to but if + + align:start position:0% +make the dollar Well we'd like to but if + + + align:start position:0% +make the dollar Well we'd like to but if +if we think that they're going to be a + + align:start position:0% +if we think that they're going to be a + + + align:start position:0% +if we think that they're going to be a +dollar apart and they're going to go to + + align:start position:0% +dollar apart and they're going to go to + + + align:start position:0% +dollar apart and they're going to go to +$10 apart we don't want to buy them at a + + align:start position:0% +$10 apart we don't want to buy them at a + + + align:start position:0% +$10 apart we don't want to buy them at a +dollar apart we want to buy them at $10 + + align:start position:0% +dollar apart we want to buy them at $10 + + + align:start position:0% +dollar apart we want to buy them at $10 +apart I mean you know yes we're a + + align:start position:0% +apart I mean you know yes we're a + + + align:start position:0% +apart I mean you know yes we're a +long-term investor but we care about our + + align:start position:0% +long-term investor but we care about our + + + align:start position:0% +long-term investor but we care about our +annual returns or 5year returns suppose + + align:start position:0% +annual returns or 5year returns suppose + + + align:start position:0% +annual returns or 5year returns suppose +this is a 20-year trade this is very + + align:start position:0% +this is a 20-year trade this is very + + + align:start position:0% +this is a 20-year trade this is very +prevalent when these things are 20 years + + align:start position:0% +prevalent when these things are 20 years + + + align:start position:0% +prevalent when these things are 20 years +out anyway it's a whole this is um it's + + align:start position:0% +out anyway it's a whole this is um it's + + + align:start position:0% +out anyway it's a whole this is um it's +a little bit it's a + + align:start position:0% +a little bit it's a + + + align:start position:0% +a little bit it's a +foundational issue it's a thing where I + + align:start position:0% +foundational issue it's a thing where I + + + align:start position:0% +foundational issue it's a thing where I +could shake the foundational + + align:start position:0% +could shake the foundational + + + align:start position:0% +could shake the foundational +underpinnings of quantitative Finance if + + align:start position:0% +underpinnings of quantitative Finance if + + + align:start position:0% +underpinnings of quantitative Finance if +you don't allow this replicating + + align:start position:0% +you don't allow this replicating + + + align:start position:0% +you don't allow this replicating +portfolio to have the same price as the + + align:start position:0% +portfolio to have the same price as the + + + align:start position:0% +portfolio to have the same price as the +actual option but mathematically you can + + align:start position:0% +actual option but mathematically you can + + + align:start position:0% +actual option but mathematically you can +see that we can replicate it certainly + + align:start position:0% +see that we can replicate it certainly + + + align:start position:0% +see that we can replicate it certainly +capital T and therefore the price at + + align:start position:0% +capital T and therefore the price at + + + align:start position:0% +capital T and therefore the price at +time Little T is just the linear + + align:start position:0% +time Little T is just the linear + + + align:start position:0% +time Little T is just the linear +combination of core prices okay so let's + + align:start position:0% +combination of core prices okay so let's + + + align:start position:0% +combination of core prices okay so let's +assume that and then obviously + + align:start position:0% +assume that and then obviously + + + align:start position:0% +assume that and then obviously +continuous function can be arbitrarily + + align:start position:0% +continuous function can be arbitrarily + + + align:start position:0% +continuous function can be arbitrarily +well approximated by piecewise linear + + align:start position:0% +well approximated by piecewise linear + + + align:start position:0% +well approximated by piecewise linear +function function therefore any + + align:start position:0% +function function therefore any + + + align:start position:0% +function function therefore any +function um at + + align:start position:0% +function um at + + + align:start position:0% +function um at +time any function with this of this + + align:start position:0% +time any function with this of this + + + align:start position:0% +time any function with this of this +form uh a derivative with a pair of that + + align:start position:0% +form uh a derivative with a pair of that + + + align:start position:0% +form uh a derivative with a pair of that +form can + + align:start position:0% +form can + + + align:start position:0% +form can +be uh replicated by a portfolio of call + + align:start position:0% +be uh replicated by a portfolio of call + + + align:start position:0% +be uh replicated by a portfolio of call +options so we can sort of handwave to + + align:start position:0% +options so we can sort of handwave to + + + align:start position:0% +options so we can sort of handwave to +kind of say this must be this must be + + align:start position:0% +kind of say this must be this must be + + + align:start position:0% +kind of say this must be this must be +true that calls are spanding set okay + + align:start position:0% +true that calls are spanding set okay + + + align:start position:0% +true that calls are spanding set okay +there's another way to look at it which + + align:start position:0% +there's another way to look at it which + + + align:start position:0% +there's another way to look at it which +is I just like from calculus where we + + align:start position:0% +is I just like from calculus where we + + + align:start position:0% +is I just like from calculus where we +can actually make explicit it what this + + align:start position:0% +can actually make explicit it what this + + + align:start position:0% +can actually make explicit it what this +spanning what this portfolio of C looks + + align:start position:0% +spanning what this portfolio of C looks + + + align:start position:0% +spanning what this portfolio of C looks +like in the arbitrary case okay so let + + align:start position:0% +like in the arbitrary case okay so let + + + align:start position:0% +like in the arbitrary case okay so let +me just uh do that + + align:start position:0% +me just uh do that + + + align:start position:0% +me just uh do that +um so you can sort of see okay there + + align:start position:0% +um so you can sort of see okay there + + + align:start position:0% +um so you can sort of see okay there +must be a linear combination uh by this + + align:start position:0% +must be a linear combination uh by this + + + align:start position:0% +must be a linear combination uh by this +for a piecewise linear therefore in the + + align:start position:0% +for a piecewise linear therefore in the + + + align:start position:0% +for a piecewise linear therefore in the +limit any continuous function must be + + align:start position:0% +limit any continuous function must be + + + align:start position:0% +limit any continuous function must be +able to be replicated by calls how many + + align:start position:0% +able to be replicated by calls how many + + + align:start position:0% +able to be replicated by calls how many +of each well it's actually a very very + + align:start position:0% +of each well it's actually a very very + + + align:start position:0% +of each well it's actually a very very +simple um very very simple result + + align:start position:0% + + + + align:start position:0% + +that is as follows and um well let's + + align:start position:0% +that is as follows and um well let's + + + align:start position:0% +that is as follows and um well let's +just write down an exact Taylor series + + align:start position:0% +just write down an exact Taylor series + + + align:start position:0% +just write down an exact Taylor series +okay to the second order so this is um + + align:start position:0% +okay to the second order so this is um + + + align:start position:0% +okay to the second order so this is um +so for any + + align:start position:0% +so for any + + + align:start position:0% +so for any +function with second derivative we let's + + align:start position:0% +function with second derivative we let's + + + align:start position:0% +function with second derivative we let's +just write down the Taylor + + align:start position:0% +just write down the Taylor + + + align:start position:0% +just write down the Taylor +series okay the first two terms and + + align:start position:0% +series okay the first two terms and + + + align:start position:0% +series okay the first two terms and +let's put the second term we just do an + + align:start position:0% +let's put the second term we just do an + + + align:start position:0% +let's put the second term we just do an +exact exact second order term so 0 To + + align:start position:0% +exact exact second order term so 0 To + + + align:start position:0% +exact exact second order term so 0 To +infinity x - c + + align:start position:0% +infinity x - c + + + align:start position:0% +infinity x - c +plus G Prime of C DC C is my dummy + + align:start position:0% +plus G Prime of C DC C is my dummy + + + align:start position:0% +plus G Prime of C DC C is my dummy +variable um actually I've gone to gone + + align:start position:0% +variable um actually I've gone to gone + + + align:start position:0% +variable um actually I've gone to gone +to plus notation here's the max of this + + align:start position:0% +to plus notation here's the max of this + + + align:start position:0% +to plus notation here's the max of this +and zero okay + + align:start position:0% +and zero okay + + + align:start position:0% +and zero okay +so so okay that's a that's an exact + + align:start position:0% +so so okay that's a that's an exact + + + align:start position:0% +so so okay that's a that's an exact +Taylor series true for any it's not an + + align:start position:0% +Taylor series true for any it's not an + + + align:start position:0% +Taylor series true for any it's not an +approximation that's exact you just + + align:start position:0% +approximation that's exact you just + + + align:start position:0% +approximation that's exact you just +integrate the right hand side by Parts + + align:start position:0% +integrate the right hand side by Parts + + + align:start position:0% +integrate the right hand side by Parts +if you want to verify maybe it's obvious + + align:start position:0% +if you want to verify maybe it's obvious + + + align:start position:0% +if you want to verify maybe it's obvious +to you but you know I'm so used to just + + align:start position:0% +to you but you know I'm so used to just + + + align:start position:0% +to you but you know I'm so used to just +doing non-exact tayor theories anyway so + + align:start position:0% +doing non-exact tayor theories anyway so + + + align:start position:0% +doing non-exact tayor theories anyway so +this is the second order so this holds + + align:start position:0% +this is the second order so this holds + + + align:start position:0% +this is the second order so this holds +for any any G exactly um and now I'm + + align:start position:0% +for any any G exactly um and now I'm + + + align:start position:0% +for any any G exactly um and now I'm +just going to make one little change + + align:start position:0% +just going to make one little change + + + align:start position:0% +just going to make one little change +which sort of might make obvious what + + align:start position:0% +which sort of might make obvious what + + + align:start position:0% +which sort of might make obvious what +we're trying to do I'm just going to + + align:start position:0% +we're trying to do I'm just going to + + + align:start position:0% +we're trying to do I'm just going to +take this dummy variable C which we're + + align:start position:0% +take this dummy variable C which we're + + + align:start position:0% +take this dummy variable C which we're +integrating over from Zer to infinity + + align:start position:0% +integrating over from Zer to infinity + + + align:start position:0% +integrating over from Zer to infinity +and just call it + + align:start position:0% + + + + align:start position:0% + +K okay certainly do + + align:start position:0% +K okay certainly do + + + align:start position:0% +K okay certainly do +that all right this now looks like the + + align:start position:0% +that all right this now looks like the + + + align:start position:0% +that all right this now looks like the +payout of a + + align:start position:0% +payout of a + + + align:start position:0% +payout of a +call right okay it's payout of the call + + align:start position:0% +call right okay it's payout of the call + + + align:start position:0% +call right okay it's payout of the call +Price now I don't want to be integrating + + align:start position:0% +Price now I don't want to be integrating + + + align:start position:0% +Price now I don't want to be integrating +remember if I want to actually get the + + align:start position:0% +remember if I want to actually get the + + + align:start position:0% +remember if I want to actually get the +call Price I take the expected value of + + align:start position:0% +call Price I take the expected value of + + + align:start position:0% +call Price I take the expected value of +this I integrate x over x with respect + + align:start position:0% +this I integrate x over x with respect + + + align:start position:0% +this I integrate x over x with respect +to its density right this is this is G + + align:start position:0% +to its density right this is this is G + + + align:start position:0% +to its density right this is this is G +of my payout function of X here here I'm + + align:start position:0% +of my payout function of X here here I'm + + + align:start position:0% +of my payout function of X here here I'm +integrating over K so I'm doing + + align:start position:0% +integrating over K so I'm doing + + + align:start position:0% +integrating over K so I'm doing +something a bit different but this is + + align:start position:0% +something a bit different but this is + + + align:start position:0% +something a bit different but this is +the call option payout right so this + + align:start position:0% +the call option payout right so this + + + align:start position:0% +the call option payout right so this +holds it's a + + align:start position:0% +holds it's a + + + align:start position:0% +holds it's a +linear linear equation obviously and of + + align:start position:0% +linear linear equation obviously and of + + + align:start position:0% +linear linear equation obviously and of +course expected expectation is a linear + + align:start position:0% +course expected expectation is a linear + + + align:start position:0% +course expected expectation is a linear +operator so I'm just going to + + align:start position:0% +operator so I'm just going to + + + align:start position:0% +operator so I'm just going to +take well I'm going to do two steps + + align:start position:0% +take well I'm going to do two steps + + + align:start position:0% +take well I'm going to do two steps +first of all I'm just going to replace x + + align:start position:0% +first of all I'm just going to replace x + + + align:start position:0% +first of all I'm just going to replace x +with my random variable s subt okay so + + align:start position:0% +with my random variable s subt okay so + + + align:start position:0% +with my random variable s subt okay so +that's can that I can + + align:start position:0% + + + + align:start position:0% + +do this also + + align:start position:0% +do this also + + + align:start position:0% +do this also +holds and formally of course s sub2 is a + + align:start position:0% +holds and formally of course s sub2 is a + + + align:start position:0% +holds and formally of course s sub2 is a +random variable so it's a function from + + align:start position:0% +random variable so it's a function from + + + align:start position:0% +random variable so it's a function from +the sample space of the real line but if + + align:start position:0% +the sample space of the real line but if + + + align:start position:0% +the sample space of the real line but if +this holds for every point on the sample + + align:start position:0% +this holds for every point on the sample + + + align:start position:0% +this holds for every point on the sample +space space right so I can write down + + align:start position:0% +space space right so I can write down + + + align:start position:0% +space space right so I can write down +this this equation between random + + align:start position:0% + + + + align:start position:0% + +variables okay here's just the integral + + align:start position:0% +variables okay here's just the integral + + + align:start position:0% +variables okay here's just the integral +over + + align:start position:0% +over + + + align:start position:0% +over +DK right so that's that holds now I'm + + align:start position:0% +DK right so that's that holds now I'm + + + align:start position:0% +DK right so that's that holds now I'm +going to take um the expectation + + align:start position:0% +going to take um the expectation + + + align:start position:0% +going to take um the expectation +operator so take + + align:start position:0% + + + + align:start position:0% + +discounted + + align:start position:0% + + + + align:start position:0% + +expected value + + align:start position:0% +expected value + + + align:start position:0% +expected value +okay so of each + + align:start position:0% + + + + align:start position:0% + +side so in other words what is my + + align:start position:0% +side so in other words what is my + + + align:start position:0% +side so in other words what is my +operator de side it looks like Zed + + align:start position:0% +operator de side it looks like Zed + + + align:start position:0% +operator de side it looks like Zed +TT expected value of given + + align:start position:0% +TT expected value of given + + + align:start position:0% +TT expected value of given +St + + align:start position:0% +St + + + align:start position:0% +St +right okay so this one is a discounted + + align:start position:0% +right okay so this one is a discounted + + + align:start position:0% +right okay so this one is a discounted +expected value that's the + + align:start position:0% + + + + align:start position:0% + +price so this + + align:start position:0% +price so this + + + align:start position:0% +price so this +becomes price of the + + align:start position:0% +becomes price of the + + + align:start position:0% +becomes price of the +derivative with payout at maturity + + align:start position:0% +derivative with payout at maturity + + + align:start position:0% +derivative with payout at maturity +G all right what do we have here well + + align:start position:0% +G all right what do we have here well + + + align:start position:0% +G all right what do we have here well +first we' got a + + align:start position:0% +first we' got a + + + align:start position:0% +first we' got a +constant right so we've got a constant + + align:start position:0% +constant right so we've got a constant + + + align:start position:0% +constant right so we've got a constant +times + + align:start position:0% + + + + align:start position:0% + +um okay so that's + + align:start position:0% + + + + align:start position:0% + +constant okay now we got the discounted + + align:start position:0% +constant okay now we got the discounted + + + align:start position:0% +constant okay now we got the discounted +expected stock price okay little bit of + + align:start position:0% +expected stock price okay little bit of + + + align:start position:0% +expected stock price okay little bit of +thought on the terms of the fundamental + + align:start position:0% +thought on the terms of the fundamental + + + align:start position:0% +thought on the terms of the fundamental +theorem will show you that the + + align:start position:0% +theorem will show you that the + + + align:start position:0% +theorem will show you that the +discounted expected stock price under + + align:start position:0% +discounted expected stock price under + + + align:start position:0% +discounted expected stock price under +this operator is the current stock price + + align:start position:0% +this operator is the current stock price + + + align:start position:0% +this operator is the current stock price +it's actually non I hand wa here not + + align:start position:0% +it's actually non I hand wa here not + + + align:start position:0% +it's actually non I hand wa here not +non-trivial but just think of the stock + + align:start position:0% +non-trivial but just think of the stock + + + align:start position:0% +non-trivial but just think of the stock +itself as a derivative right with payout + + align:start position:0% +itself as a derivative right with payout + + + align:start position:0% +itself as a derivative right with payout +s and apply the fundamental theorem okay + + align:start position:0% +s and apply the fundamental theorem okay + + + align:start position:0% +s and apply the fundamental theorem okay +this has to be has to be the case + + align:start position:0% +this has to be has to be the case + + + align:start position:0% +this has to be has to be the case +because the replicating portfolio of the + + align:start position:0% +because the replicating portfolio of the + + + align:start position:0% +because the replicating portfolio of the +stock is just a holding of the + + align:start position:0% +stock is just a holding of the + + + align:start position:0% +stock is just a holding of the +stock okay plus and then we just the + + align:start position:0% +stock okay plus and then we just the + + + align:start position:0% +stock okay plus and then we just the +take the integral so the expectation + + align:start position:0% +take the integral so the expectation + + + align:start position:0% +take the integral so the expectation +inside the + + align:start position:0% +inside the + + + align:start position:0% +inside the +integral + + align:start position:0% + + + + align:start position:0% + +um okay so now I've got discounted + + align:start position:0% +um okay so now I've got discounted + + + align:start position:0% +um okay so now I've got discounted +expected payout of this and the + + align:start position:0% +expected payout of this and the + + + align:start position:0% +expected payout of this and the +discounted expected payout of this is + + align:start position:0% +discounted expected payout of this is + + + align:start position:0% +discounted expected payout of this is +just the call + + align:start position:0% + + + + align:start position:0% + +Price with stri K + + align:start position:0% + + + + align:start position:0% + +right okay so I really like this this + + align:start position:0% +right okay so I really like this this + + + align:start position:0% +right okay so I really like this this +formula I mean in some sense it's it's a + + align:start position:0% +formula I mean in some sense it's it's a + + + align:start position:0% +formula I mean in some sense it's it's a +very + + align:start position:0% +very + + + align:start position:0% +very +nothing tooo complicated about how to + + align:start position:0% +nothing tooo complicated about how to + + + align:start position:0% +nothing tooo complicated about how to +derive it but it says explicitly now how + + align:start position:0% +derive it but it says explicitly now how + + + align:start position:0% +derive it but it says explicitly now how +do I replicate an + + align:start position:0% +do I replicate an + + + align:start position:0% +do I replicate an +arbitrary derivative product with payout + + align:start position:0% +arbitrary derivative product with payout + + + align:start position:0% +arbitrary derivative product with payout +G of X or G of s at maturity well as + + align:start position:0% +G of X or G of s at maturity well as + + + align:start position:0% +G of X or G of s at maturity well as +clear I replicate it by g0 zero coupon + + align:start position:0% +clear I replicate it by g0 zero coupon + + + align:start position:0% +clear I replicate it by g0 zero coupon +bonds okay so I have g0 of zero coupon + + align:start position:0% +bonds okay so I have g0 of zero coupon + + + align:start position:0% +bonds okay so I have g0 of zero coupon +bonds that's this I have G Prime Z Z of + + align:start position:0% +bonds that's this I have G Prime Z Z of + + + align:start position:0% +bonds that's this I have G Prime Z Z of +stock that's this and I have this linear + + align:start position:0% +stock that's this and I have this linear + + + align:start position:0% +stock that's this and I have this linear +combination of + + align:start position:0% + + + + align:start position:0% + +calls okay all right so there is you + + align:start position:0% +calls okay all right so there is you + + + align:start position:0% +calls okay all right so there is you +it's kind of kind of makes sense right + + align:start position:0% +it's kind of kind of makes sense right + + + align:start position:0% +it's kind of kind of makes sense right +you want the zero coupon bond amount is + + align:start position:0% +you want the zero coupon bond amount is + + + align:start position:0% +you want the zero coupon bond amount is +just the intercept of G the number of + + align:start position:0% +just the intercept of G the number of + + + align:start position:0% +just the intercept of G the number of +stocks is just the slope of g at zero + + align:start position:0% +stocks is just the slope of g at zero + + + align:start position:0% +stocks is just the slope of g at zero +and then I have this linear combination + + align:start position:0% +and then I have this linear combination + + + align:start position:0% +and then I have this linear combination +of core prices okay I've just proved + + align:start position:0% +of core prices okay I've just proved + + + align:start position:0% +of core prices okay I've just proved +that by taking this and taking expected + + align:start position:0% +that by taking this and taking expected + + + align:start position:0% +that by taking this and taking expected +values all right + + align:start position:0% +values all right + + + align:start position:0% +values all right +so this is sort of a looking at the uh + + align:start position:0% +so this is sort of a looking at the uh + + + align:start position:0% +so this is sort of a looking at the uh +duality of call option option prices and + + align:start position:0% +duality of call option option prices and + + + align:start position:0% +duality of call option option prices and +probabilities in different ways but then + + align:start position:0% +probabilities in different ways but then + + + align:start position:0% +probabilities in different ways but then +also how calls span everything so the + + align:start position:0% +also how calls span everything so the + + + align:start position:0% +also how calls span everything so the +calls in some sense are the Primitive + + align:start position:0% +calls in some sense are the Primitive + + + align:start position:0% +calls in some sense are the Primitive +primitive information once I know all + + align:start position:0% +primitive information once I know all + + + align:start position:0% +primitive information once I know all +call option prices is I know the + + align:start position:0% +call option prices is I know the + + + align:start position:0% +call option prices is I know the +probability distribution exactly okay so + + align:start position:0% +probability distribution exactly okay so + + + align:start position:0% +probability distribution exactly okay so +there are a couple of um sort of + + align:start position:0% +there are a couple of um sort of + + + align:start position:0% +there are a couple of um sort of +interesting further questions you might + + align:start position:0% +interesting further questions you might + + + align:start position:0% +interesting further questions you might +might want to want to pose we seem to + + align:start position:0% +might want to want to pose we seem to + + + align:start position:0% +might want to want to pose we seem to +have done everything + + align:start position:0% +have done everything + + + align:start position:0% +have done everything +here with regard + + align:start position:0% +here with regard + + + align:start position:0% +here with regard +to uh the distribution at time capital T + + align:start position:0% +to uh the distribution at time capital T + + + align:start position:0% +to uh the distribution at time capital T +and that's true I know all the calls I + + align:start position:0% +and that's true I know all the calls I + + + align:start position:0% +and that's true I know all the calls I +know + + align:start position:0% +know + + + align:start position:0% +know +the distribution at time capital T I + + align:start position:0% +the distribution at time capital T I + + + align:start position:0% +the distribution at time capital T I +know all the calls I know the price of + + align:start position:0% +know all the calls I know the price of + + + align:start position:0% +know all the calls I know the price of +any option with a payout defined slow + + align:start position:0% +any option with a payout defined slow + + + align:start position:0% +any option with a payout defined slow +solely by a function at capital T but I + + align:start position:0% +solely by a function at capital T but I + + + align:start position:0% +solely by a function at capital T but I +said nothing about the path that takes + + align:start position:0% +said nothing about the path that takes + + + align:start position:0% +said nothing about the path that takes +the stock from today until capital T so + + align:start position:0% +the stock from today until capital T so + + + align:start position:0% +the stock from today until capital T so +I just going to leave you with two two + + align:start position:0% +I just going to leave you with two two + + + align:start position:0% +I just going to leave you with two two +things to to think about + + align:start position:0% +things to to think about + + + align:start position:0% +things to to think about +um actually it's one thing to think + + align:start position:0% + + + + align:start position:0% + +about two people thought about it a + + align:start position:0% + + + + align:start position:0% + +lot okay it's the following it's the + + align:start position:0% +lot okay it's the following it's the + + + align:start position:0% +lot okay it's the following it's the +following question which now we'll start + + align:start position:0% +following question which now we'll start + + + align:start position:0% +following question which now we'll start +transitioning into stochastic calculus + + align:start position:0% +transitioning into stochastic calculus + + + align:start position:0% +transitioning into stochastic calculus +and stochastic processes a little bit + + align:start position:0% +and stochastic processes a little bit + + + align:start position:0% +and stochastic processes a little bit +okay so we know let's just + + align:start position:0% +okay so we know let's just + + + align:start position:0% +okay so we know let's just +imagine two + + align:start position:0% + + + + align:start position:0% + +times all right so suppose we + + align:start position:0% + + + + align:start position:0% + +know so we know the set of + + align:start position:0% +know so we know the set of + + + align:start position:0% +know so we know the set of +all Co prices with maturity T1 + + align:start position:0% +all Co prices with maturity T1 + + + align:start position:0% +all Co prices with maturity T1 +okay 4 + + align:start position:0% + + + + align:start position:0% + +K and the set of all Coral prices with + + align:start position:0% +K and the set of all Coral prices with + + + align:start position:0% +K and the set of all Coral prices with +maturity + + align:start position:0% +maturity + + + align:start position:0% +maturity +T2 for + + align:start position:0% +T2 for + + + align:start position:0% +T2 for +K + + align:start position:0% + + + + align:start position:0% + +okay okay so then we know the + + align:start position:0% +okay okay so then we know the + + + align:start position:0% +okay okay so then we know the +distribution well there two + + align:start position:0% +distribution well there two + + + align:start position:0% +distribution well there two +distributions we know the distribution + + align:start position:0% +distributions we know the distribution + + + align:start position:0% +distributions we know the distribution +of T1 given us + + align:start position:0% +of T1 given us + + + align:start position:0% +of T1 given us +T and + + align:start position:0% + + + + align:start position:0% + +okay but do we know the distribution of + + align:start position:0% +okay but do we know the distribution of + + + align:start position:0% +okay but do we know the distribution of +the stock at s at T2 given + + align:start position:0% + + + + align:start position:0% + +T1 right more of a general Point suppose + + align:start position:0% +T1 right more of a general Point suppose + + + align:start position:0% +T1 right more of a general Point suppose +I know this for all + + align:start position:0% + + + + align:start position:0% + +T let's put t z here + + align:start position:0% + + + + align:start position:0% + +okay I know all option prices of all + + align:start position:0% +okay I know all option prices of all + + + align:start position:0% +okay I know all option prices of all +maturities and all strikes + + align:start position:0% +maturities and all strikes + + + align:start position:0% +maturities and all strikes +okay can I + + align:start position:0% +okay can I + + + align:start position:0% +okay can I +determine the stochastic process for + + align:start position:0% + + + + align:start position:0% + +St I over this time is the underlying + + align:start position:0% +St I over this time is the underlying + + + align:start position:0% +St I over this time is the underlying +stochastic process for the stock price + + align:start position:0% +stochastic process for the stock price + + + align:start position:0% +stochastic process for the stock price +fully determined by knowing all call + + align:start position:0% +fully determined by knowing all call + + + align:start position:0% +fully determined by knowing all call +option prices for all strikes and all + + align:start position:0% +option prices for all strikes and all + + + align:start position:0% +option prices for all strikes and all +maturities okay the marginal + + align:start position:0% +maturities okay the marginal + + + align:start position:0% +maturities okay the marginal +distributions or the conditional + + align:start position:0% +distributions or the conditional + + + align:start position:0% +distributions or the conditional +distributions for all maturities are + + align:start position:0% +distributions for all maturities are + + + align:start position:0% +distributions for all maturities are +determined because we know that + + align:start position:0% +determined because we know that + + + align:start position:0% +determined because we know that +here well you probably see this is a + + align:start position:0% +here well you probably see this is a + + + align:start position:0% +here well you probably see this is a +rephrasing of sort of a finite + + align:start position:0% +rephrasing of sort of a finite + + + align:start position:0% +rephrasing of sort of a finite +dimensional problem from from + + align:start position:0% +dimensional problem from from + + + align:start position:0% +dimensional problem from from +probability the answer is + + align:start position:0% + + + + align:start position:0% + +no and the reason to think about is if I + + align:start position:0% +no and the reason to think about is if I + + + align:start position:0% +no and the reason to think about is if I +know all the I me my my intuition for + + align:start position:0% +know all the I me my my intuition for + + + align:start position:0% +know all the I me my my intuition for +this is if I know all the distributions + + align:start position:0% +this is if I know all the distributions + + + align:start position:0% +this is if I know all the distributions +that yeah think about just a denser and + + align:start position:0% +that yeah think about just a denser and + + + align:start position:0% +that yeah think about just a denser and +denser grid of times that I know the + + align:start position:0% +denser grid of times that I know the + + + align:start position:0% +denser grid of times that I know the +distribution well getting closer and + + align:start position:0% +distribution well getting closer and + + + align:start position:0% +distribution well getting closer and +closer I can still allow the stock to + + align:start position:0% +closer I can still allow the stock to + + + align:start position:0% +closer I can still allow the stock to +flip instantaneously quickly imagine + + align:start position:0% +flip instantaneously quickly imagine + + + align:start position:0% +flip instantaneously quickly imagine +they're all essentially symmetric + + align:start position:0% +they're all essentially symmetric + + + align:start position:0% +they're all essentially symmetric +distributions and they're all roughly + + align:start position:0% +distributions and they're all roughly + + + align:start position:0% +distributions and they're all roughly +the same expanding out I can imagine + + align:start position:0% +the same expanding out I can imagine + + + align:start position:0% +the same expanding out I can imagine +this the stock flipping + + align:start position:0% +this the stock flipping + + + align:start position:0% +this the stock flipping +discontinuously right over an + + align:start position:0% +discontinuously right over an + + + align:start position:0% +discontinuously right over an +arbitrarily small time interval so + + align:start position:0% +arbitrarily small time interval so + + + align:start position:0% +arbitrarily small time interval so +without a constraint on the continuity + + align:start position:0% +without a constraint on the continuity + + + align:start position:0% +without a constraint on the continuity +of this process or mathematical + + align:start position:0% +of this process or mathematical + + + align:start position:0% +of this process or mathematical +constraints on this process you can't + + align:start position:0% +constraints on this process you can't + + + align:start position:0% +constraints on this process you can't +determine the actual process for the + + align:start position:0% +determine the actual process for the + + + align:start position:0% +determine the actual process for the +stock even given all the option prices + + align:start position:0% +stock even given all the option prices + + + align:start position:0% +stock even given all the option prices +called option prices kind of a okay so + + align:start position:0% +called option prices kind of a okay so + + + align:start position:0% +called option prices kind of a okay so +there are two um so Ty Emanuel + + align:start position:0% +there are two um so Ty Emanuel + + + align:start position:0% +there are two um so Ty Emanuel +durman who was at Goldman Sachs now at + + align:start position:0% +durman who was at Goldman Sachs now at + + + align:start position:0% +durman who was at Goldman Sachs now at +Columbia and Bruno dupier who's I think + + align:start position:0% +Columbia and Bruno dupier who's I think + + + align:start position:0% +Columbia and Bruno dupier who's I think +still at Bloomberg this is this is the + + align:start position:0% +still at Bloomberg this is this is the + + + align:start position:0% +still at Bloomberg this is this is the +early 90s basically determine the + + align:start position:0% +early 90s basically determine the + + + align:start position:0% +early 90s basically determine the +conditions that you need and basically + + align:start position:0% +conditions that you need and basically + + + align:start position:0% +conditions that you need and basically +the conditions are this just a stock has + + align:start position:0% +the conditions are this just a stock has + + + align:start position:0% +the conditions are this just a stock has +to be a diffusion process if it is a + + align:start position:0% +to be a diffusion process if it is a + + + align:start position:0% +to be a diffusion process if it is a +diffusion process I as a brown the + + align:start position:0% +diffusion process I as a brown the + + + align:start position:0% +diffusion process I as a brown the +random term as a brownie motion then it + + align:start position:0% +random term as a brownie motion then it + + + align:start position:0% +random term as a brownie motion then it +is actually fully determined okay and + + align:start position:0% +is actually fully determined okay and + + + align:start position:0% +is actually fully determined okay and +there's a really nice elegant elegant + + align:start position:0% +there's a really nice elegant elegant + + + align:start position:0% +there's a really nice elegant elegant +result so this is this is what gets + + align:start position:0% +result so this is this is what gets + + + align:start position:0% +result so this is this is what gets +mathematically quite nice and and a + + align:start position:0% +mathematically quite nice and and a + + + align:start position:0% +mathematically quite nice and and a +little tricky um but there's a + + align:start position:0% +little tricky um but there's a + + + align:start position:0% +little tricky um but there's a +practical um implication of this as well + + align:start position:0% +practical um implication of this as well + + + align:start position:0% +practical um implication of this as well +which + + align:start position:0% +which + + + align:start position:0% +which +is in practice ice I will know a finite + + align:start position:0% +is in practice ice I will know a finite + + + align:start position:0% +is in practice ice I will know a finite +subset + + align:start position:0% +subset + + + align:start position:0% +subset +of call options those prices will be + + align:start position:0% +of call options those prices will be + + + align:start position:0% +of call options those prices will be +available to me in the market okay so + + align:start position:0% +available to me in the market okay so + + + align:start position:0% +available to me in the market okay so +they will be given okay so one thing I + + align:start position:0% +they will be given okay so one thing I + + + align:start position:0% +they will be given okay so one thing I +know for sure is that even with a very + + align:start position:0% +know for sure is that even with a very + + + align:start position:0% +know for sure is that even with a very +densely set of call option prices there + + align:start position:0% +densely set of call option prices there + + + align:start position:0% +densely set of call option prices there +will be some other derivative prices + + align:start position:0% +will be some other derivative prices + + + align:start position:0% +will be some other derivative prices +whose price is not exactly determined by + + align:start position:0% +whose price is not exactly determined by + + + align:start position:0% +whose price is not exactly determined by +that set of calls because in particular + + align:start position:0% +that set of calls because in particular + + + align:start position:0% +that set of calls because in particular +I know that the set of R does not + + align:start position:0% +I know that the set of R does not + + + align:start position:0% +I know that the set of R does not +determine the underlying stochastic + + align:start position:0% +determine the underlying stochastic + + + align:start position:0% +determine the underlying stochastic +process even if I knew all of them right + + align:start position:0% +process even if I knew all of them right + + + align:start position:0% +process even if I knew all of them right +so that's a very important thing for + + align:start position:0% +so that's a very important thing for + + + align:start position:0% +so that's a very important thing for +Traders to understand is that even if I + + align:start position:0% +Traders to understand is that even if I + + + align:start position:0% +Traders to understand is that even if I +know a lot of Market information someone + + align:start position:0% +know a lot of Market information someone + + + align:start position:0% +know a lot of Market information someone +gives me here are the prices of a number + + align:start position:0% +gives me here are the prices of a number + + + align:start position:0% +gives me here are the prices of a number +of a large number of European options + + align:start position:0% +of a large number of European options + + + align:start position:0% +of a large number of European options +European call options I can + + align:start position:0% +European call options I can + + + align:start position:0% +European call options I can +trade there may be a complicate a + + align:start position:0% +trade there may be a complicate a + + + align:start position:0% +trade there may be a complicate a +complex or non-standard derivative + + align:start position:0% +complex or non-standard derivative + + + align:start position:0% +complex or non-standard derivative +product whose price is not determined + + align:start position:0% +product whose price is not determined + + + align:start position:0% +product whose price is not determined +uniquely simply by knowing those options + + align:start position:0% +uniquely simply by knowing those options + + + align:start position:0% +uniquely simply by knowing those options +and and that's is one of the challenges + + align:start position:0% +and and that's is one of the challenges + + + align:start position:0% +and and that's is one of the challenges +for some of the the Quant groups + + align:start position:0% +for some of the the Quant groups + + + align:start position:0% +for some of the the Quant groups +so anyway with that that is all I wanted + + align:start position:0% +so anyway with that that is all I wanted + + + align:start position:0% +so anyway with that that is all I wanted +to convey I'm happy to take some + + align:start position:0% +to convey I'm happy to take some + + + align:start position:0% +to convey I'm happy to take some +questions and uh um thank you for um + + align:start position:0% +questions and uh um thank you for um + + + align:start position:0% +questions and uh um thank you for um +thank you for your time and for having + + align:start position:0% +thank you for your time and for having + + + align:start position:0% +thank you for your time and for having +me appreciate + + align:start position:0% +me appreciate + + + align:start position:0% +me appreciate +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +it um yeah I had questions about I was + + align:start position:0% +it um yeah I had questions about I was + + + align:start position:0% +it um yeah I had questions about I was +just wondering so you said the call Al + + align:start position:0% +just wondering so you said the call Al + + + align:start position:0% +just wondering so you said the call Al +set of all calls basically spans space + + align:start position:0% +set of all calls basically spans space + + + align:start position:0% +set of all calls basically spans space +of all possible uh payouts right yes so + + align:start position:0% +of all possible uh payouts right yes so + + + align:start position:0% +of all possible uh payouts right yes so +I was just wondering maybe if we could + + align:start position:0% +I was just wondering maybe if we could + + + align:start position:0% +I was just wondering maybe if we could +change and select some other such bases + + align:start position:0% +change and select some other such bases + + + align:start position:0% +change and select some other such bases +for for for spanning it you know instead + + align:start position:0% +for for for spanning it you know instead + + + align:start position:0% +for for for spanning it you know instead +of call maybe some other kind + + align:start position:0% +of call maybe some other kind + + + align:start position:0% +of call maybe some other kind +of + + align:start position:0% +of + + + align:start position:0% +of +basic payoff that could still spend the + + align:start position:0% +basic payoff that could still spend the + + + align:start position:0% +basic payoff that could still spend the +same thing and maybe it's more easily + + align:start position:0% +same thing and maybe it's more easily + + + align:start position:0% +same thing and maybe it's more easily +tradable or something yeah that's a + + align:start position:0% +tradable or something yeah that's a + + + align:start position:0% +tradable or something yeah that's a +that's a good I mean there must be be + + align:start position:0% +that's a good I mean there must be be + + + align:start position:0% +that's a good I mean there must be be +many if I can uh I mean but this given + + align:start position:0% +many if I can uh I mean but this given + + + align:start position:0% +many if I can uh I mean but this given +that this is the the simplest expansion + + align:start position:0% +that this is the the simplest expansion + + + align:start position:0% +that this is the the simplest expansion +of a the function G an arbitrary + + align:start position:0% +of a the function G an arbitrary + + + align:start position:0% +of a the function G an arbitrary +function G and the second term comes in + + align:start position:0% +function G and the second term comes in + + + align:start position:0% +function G and the second term comes in +with this call + + align:start position:0% +with this call + + + align:start position:0% +with this call +payout right gives us its Elegance right + + align:start position:0% +payout right gives us its Elegance right + + + align:start position:0% +payout right gives us its Elegance right +now of course if I know all the + + align:start position:0% +now of course if I know all the + + + align:start position:0% +now of course if I know all the +digitals I know the cumulative + + align:start position:0% +digitals I know the cumulative + + + align:start position:0% +digitals I know the cumulative +distribution function and therefore I + + align:start position:0% +distribution function and therefore I + + + align:start position:0% +distribution function and therefore I +know the density so I mean digitals do + + align:start position:0% +know the density so I mean digitals do + + + align:start position:0% +know the density so I mean digitals do +the same and in fact you arod de Bru + + align:start position:0% +the same and in fact you arod de Bru + + + align:start position:0% +the same and in fact you arod de Bru +Securities which are sort of building + + align:start position:0% +Securities which are sort of building + + + align:start position:0% +Securities which are sort of building +blocks which is something that pays off + + align:start position:0% +blocks which is something that pays off + + + align:start position:0% +blocks which is something that pays off +one in a particular State sample State + + align:start position:0% +one in a particular State sample State + + + align:start position:0% +one in a particular State sample State +also are building blocks + + align:start position:0% +also are building blocks + + + align:start position:0% +also are building blocks +so yeah yeah I mean some could be you + + align:start position:0% +so yeah yeah I mean some could be you + + + align:start position:0% +so yeah yeah I mean some could be you +can think about an arbitary basis that + + align:start position:0% +can think about an arbitary basis that + + + align:start position:0% +can think about an arbitary basis that +will span an arbitary basis of of + + align:start position:0% +will span an arbitary basis of of + + + align:start position:0% +will span an arbitary basis of of +functions that will span any continuous + + align:start position:0% +functions that will span any continuous + + + align:start position:0% +functions that will span any continuous +function I mean some you could do it in + + align:start position:0% +function I mean some you could do it in + + + align:start position:0% +function I mean some you could do it in +any any polinomial expansion if you have + + align:start position:0% +any any polinomial expansion if you have + + + align:start position:0% +any any polinomial expansion if you have +a price of any of those payouts and I've + + align:start position:0% +a price of any of those payouts and I've + + + align:start position:0% +a price of any of those payouts and I've +got my my spanning set right but this is + + align:start position:0% +got my my spanning set right but this is + + + align:start position:0% +got my my spanning set right but this is +the most elegant + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% + + + + align:start position:0% + +question well because Market is + + align:start position:0% +question well because Market is + + + align:start position:0% +question well because Market is +incomplete so you cannot sort of use + + align:start position:0% +incomplete so you cannot sort of use + + + align:start position:0% +incomplete so you cannot sort of use +core option to rep replicate the stock + + align:start position:0% +core option to rep replicate the stock + + + align:start position:0% +core option to rep replicate the stock +itself um you can use the call option to + + align:start position:0% +itself um you can use the call option to + + + align:start position:0% +itself um you can use the call option to +replicate the + + align:start position:0% +replicate the + + + align:start position:0% +replicate the +stock yeah is it like and as long as you + + align:start position:0% +stock yeah is it like and as long as you + + + align:start position:0% +stock yeah is it like and as long as you +have zero c as you can see from here I + + align:start position:0% +have zero c as you can see from here I + + + align:start position:0% +have zero c as you can see from here I +can just re reorganize anything here to + + align:start position:0% +can just re reorganize anything here to + + + align:start position:0% +can just re reorganize anything here to +zero coupon Bond stock and a set of + + align:start position:0% +zero coupon Bond stock and a set of + + + align:start position:0% +zero coupon Bond stock and a set of +calls will span anything at with + + align:start position:0% +calls will span anything at with + + + align:start position:0% +calls will span anything at with +maturity T what they sort of saying is + + align:start position:0% +maturity T what they sort of saying is + + + align:start position:0% +maturity T what they sort of saying is +if I have this strange process with + + align:start position:0% +if I have this strange process with + + + align:start position:0% +if I have this strange process with +jumps right and flips and + + align:start position:0% +jumps right and flips and + + + align:start position:0% +jumps right and flips and +discontinuities then the market is + + align:start position:0% +discontinuities then the market is + + + align:start position:0% +discontinuities then the market is +incomplete I guess is what what this is + + align:start position:0% +incomplete I guess is what what this is + + + align:start position:0% +incomplete I guess is what what this is +saying okay Alo in is due to that + + align:start position:0% +saying okay Alo in is due to that + + + align:start position:0% +saying okay Alo in is due to that +inconvenience yeah I mean the sense of + + align:start position:0% +inconvenience yeah I mean the sense of + + + align:start position:0% +inconvenience yeah I mean the sense of +most Finance in fact all continuous Time + + align:start position:0% +most Finance in fact all continuous Time + + + align:start position:0% +most Finance in fact all continuous Time +Finance will assume there's some + + align:start position:0% +Finance will assume there's some + + + align:start position:0% +Finance will assume there's some +diffusion process for some process for + + align:start position:0% +diffusion process for some process for + + + align:start position:0% +diffusion process for some process for +the stock which has + + align:start position:0% +the stock which has + + + align:start position:0% +the stock which has +some BR New Motion there's some function + + align:start position:0% +some BR New Motion there's some function + + + align:start position:0% +some BR New Motion there's some function +here and some function for the drift + + align:start position:0% +here and some function for the drift + + + align:start position:0% +here and some function for the drift +term right in that case then all the + + align:start position:0% +term right in that case then all the + + + align:start position:0% +term right in that case then all the +core prices do + + align:start position:0% +core prices do + + + align:start position:0% +core prices do +determine right if you think there's + + align:start position:0% +determine right if you think there's + + + align:start position:0% +determine right if you think there's +some exogenous flipping parameter right + + align:start position:0% +some exogenous flipping parameter right + + + align:start position:0% +some exogenous flipping parameter right +it's that's my intuition for it so there + + align:start position:0% +it's that's my intuition for it so there + + + align:start position:0% +it's that's my intuition for it so there +some that's why this is incomplete so + + align:start position:0% +some that's why this is incomplete so + + + align:start position:0% +some that's why this is incomplete so +this will not determine so in particular + + align:start position:0% +this will not determine so in particular + + + align:start position:0% +this will not determine so in particular +I could know all these core prices then + + align:start position:0% +I could know all these core prices then + + + align:start position:0% +I could know all these core prices then +I could determine a particular + + align:start position:0% +I could determine a particular + + + align:start position:0% +I could determine a particular +derivative product it could be the + + align:start position:0% +derivative product it could be the + + + align:start position:0% +derivative product it could be the +number of times that in an arbitrarily + + align:start position:0% +number of times that in an arbitrarily + + + align:start position:0% +number of times that in an arbitrarily +small interval the stock is you flips + + align:start position:0% +small interval the stock is you flips + + + align:start position:0% +small interval the stock is you flips +this many times I mean there something + + align:start position:0% +this many times I mean there something + + + align:start position:0% +this many times I mean there something +you can create whatever you like for a + + align:start position:0% +you can create whatever you like for a + + + align:start position:0% +you can create whatever you like for a +derivative then it would be incomplete + + align:start position:0% +derivative then it would be incomplete + + + align:start position:0% +derivative then it would be incomplete +with these calls yeah so so in this case + + align:start position:0% +with these calls yeah so so in this case + + + align:start position:0% +with these calls yeah so so in this case +go back to previous question as we just + + align:start position:0% +go back to previous question as we just + + + align:start position:0% +go back to previous question as we just +mentioned the second order derivative of + + align:start position:0% +mentioned the second order derivative of + + + align:start position:0% +mentioned the second order derivative of +call option with respect to strike is ke + + align:start position:0% +call option with respect to strike is ke + + + align:start position:0% +call option with respect to strike is ke +neutral density so in this case it was + + align:start position:0% +neutral density so in this case it was + + + align:start position:0% +neutral density so in this case it was +not + + align:start position:0% +not + + + align:start position:0% +not +that risk neutral density is a + + align:start position:0% +that risk neutral density is a + + + align:start position:0% +that risk neutral density is a +particular instance of that rather it's + + align:start position:0% +particular instance of that rather it's + + + align:start position:0% +particular instance of that rather it's +not uniquely determined right no the + + align:start position:0% +not uniquely determined right no the + + + align:start position:0% +not uniquely determined right no the +risk neutral density is uniquely + + align:start position:0% +risk neutral density is uniquely + + + align:start position:0% +risk neutral density is uniquely +determined the stochastic process for SD + + align:start position:0% +determined the stochastic process for SD + + + align:start position:0% +determined the stochastic process for SD +overall time is not stochastic is not + + align:start position:0% +overall time is not stochastic is not + + + align:start position:0% +overall time is not stochastic is not +uniquely determined so this is uniquely + + align:start position:0% +uniquely determined so this is uniquely + + + align:start position:0% +uniquely determined so this is uniquely +determined oops by by call option + + align:start position:0% + + + + align:start position:0% + +prices that is uniquely + + align:start position:0% +prices that is uniquely + + + align:start position:0% +prices that is uniquely +determined okay but knowing the + + align:start position:0% +determined okay but knowing the + + + align:start position:0% +determined okay but knowing the +conditional distribution of S capital T + + align:start position:0% +conditional distribution of S capital T + + + align:start position:0% +conditional distribution of S capital T +given s Little T doesn't determine + + align:start position:0% +given s Little T doesn't determine + + + align:start position:0% +given s Little T doesn't determine +the process of the stock price to get + + align:start position:0% +the process of the stock price to get + + + align:start position:0% +the process of the stock price to get +there I can think of infinitely many + + align:start position:0% +there I can think of infinitely many + + + align:start position:0% +there I can think of infinitely many +processes of the stock price that give + + align:start position:0% +processes of the stock price that give + + + align:start position:0% +processes of the stock price that give +rise to this + + align:start position:0% +rise to this + + + align:start position:0% +rise to this +distribution okay that's what's not + + align:start position:0% + + + + align:start position:0% + +determined the ter the terminal + + align:start position:0% +determined the ter the terminal + + + align:start position:0% +determined the ter the terminal +distribution is is is uniquely + + align:start position:0% +distribution is is is uniquely + + + align:start position:0% +distribution is is is uniquely +determined by the call option prices + + align:start position:0% +determined by the call option prices + + + align:start position:0% +determined by the call option prices +nothing else so in this case if we take + + align:start position:0% +nothing else so in this case if we take + + + align:start position:0% +nothing else so in this case if we take +real data so we will get a particular + + align:start position:0% +real data so we will get a particular + + + align:start position:0% +real data so we will get a particular +rity for each particular stock that's + + align:start position:0% +rity for each particular stock that's + + + align:start position:0% +rity for each particular stock that's +correct okay that's correct + + align:start position:0% +correct okay that's correct + + + align:start position:0% +correct okay that's correct +all right thank you very much appreciate + + align:start position:0% +all right thank you very much appreciate + + + align:start position:0% +all right thank you very much appreciate +it \ No newline at end of file diff --git a/eXUFm8lA5yE.txt b/eXUFm8lA5yE.txt new file mode 100644 index 0000000000000000000000000000000000000000..c1362fee573fa18c5541f48945b51724832e95bb --- /dev/null +++ b/eXUFm8lA5yE.txt @@ -0,0 +1,1937 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: And today I'll +continue with both ideal and + +non-ideal, or real, +liquid mixtures. + +And let me just say the reason +we're in some sense lavishing + +so much attention on this topic +is because, after all, + +there's just an enormous amount +of chemistry that + +happens in liquid mixtures. + +Awful lot of biology. + +Awful lot of just processing +of stuff. + +Distillation and everything +else. + +So there's so much chemistry +that takes place in liquid + +mixtures that it is really +important to have a sense of + +what the free energy and +chemical potential of each of + +the species is doing in there. + +Because of course this is what +directly guides the chemistry + +that happens. + +So I just want to start by +finishing up something, a + +couple of things, from the +topics from the last lecture. + +One of them is, I derived an +expression for the lever rule. + +And I just wanted to +make a little more + +explicit the result. + +It may not have been +completely clear. + +So, I just want to +go back to that. + +We had looked at what happens +if you start at some + +particular point, labeled one, +and work your way up. + +So we're raising the pressure. + +So we're in the all gas +region to start. + +All gas region of the +phase diagram. + +This is xB and yB. + +The liquid and gas mole +fractions of B. And the idea + +is that here is our +initial value. + +Now we're only in +the gas phase. + +There is no liquid. + +So this is yB of one. + +There is no xB at this point. + +We raise the pressure. + +And at some point, depending on +where we end, we then look + +to both coexistence curves to +determine the compositions of + +both the liquid and +the gas phases. + +So when we look out here, +at the liquid phase. + +That gives us xB. + +At where I labeled point two, so +there's two after we raise + +the pressure. + +We started at one. + +And then over here, we look at +the gas phase coexistence + +curve. so there's our yB +value at two, right? + +And I derived an expression for +the ratio of the number of + +moles in the gas and +liquid phases. + +Because the idea here is, let's +say you're working your + +way up on the curve. + +If you just barely get to the +coexistence curve, of course + +then you could see how +much material you've + +got in the two phases. + +But there's very little +material still. + +You've still got almost +everything in the gas phase + +when you first reach here. + +And as you work your way up in +pressure, you'd have more and + +more liquid. + +Of course, if you were to just +keep going, you'd get into the + +pure liquid phase. + +Typically, though, you might +stop somewhere in the middle + +and have some reasonable amount +of material in both + +phases, and you want +to find out the + +composition in each phase. + +And also, want to know +how much material + +there is in each phase. + +So the result that I derived +was n gas at two + +over n liquid at two. + +The ratio of total moles in +the gas to the liquid. + +What I derived was xA of +two minus yA of one. + +Over yA of one. + +Minus yA of two, and I just want +to, in some sense, finish + +up by making the obvious +substitution, which is, of + +course these are +mole fractions. + +So I can just write xA +is one minus xB. + +And yA is one minus yB. + +And I just want to put this in +the terms that are written + +here in the phase diagram. + +When I got to this result I +pointed out that therefore you + +can use the lever rule. + +And I just want to make that +a little bit more explicit. + +So using that relation, then we +can see that ng of two over + +nl of two, total number of moles +in the gas to the liquid + +is, now I'm going to substitute +in to get yB of one + +minus xB of two over yB of +two minus yB of one. + +So all I've done here is +substitute in these + +expressions. + +And now I'm going to just +switch both of these. + +And so I'm going to multiply +both sides by negative one. + +So I can write xB of two minus +yB of one over yB of + +one minus yB of two. + +So that's the result +that I want. + +Because if I look at the two +segments of this line, on + +either side of the pressure +value I've reached, then what + +I see, of course, is that +over here I've got xB of + +two minus yB of one. + +That's this. + +And this part is yB of +one minus yB of two. + +That is, it's this part. + +And that's here. + +And so that's the point, is that +the ratio of moles in the + +gas and liquid phases is just +given by the two segments of + +this on either side. + +And so what this allows us to +see very simply is alright, + +I'm going to raise the pressure +at some point. + +And depending on how much +material I feel like I need to + +collect in the new phase, I +can always determine that + +simply by reading off the phase +diagram what the ratio + +of these two segment +lengths is. + +Now what I want to do. + +What what we've done mostly is +just go through these phase + +diagrams, see how +to read them. + +How to follow events on them +as you change pressure in a + +diagram like this. + +Or change temperature +in diagrams like I + +also showed last time. + +Now what I'd like to do is go a +little bit further and just + +look at expressions for the +chemical potential and the + +free energies. + +So that we can, a little more +quantitatively, see + +what's going on. + +So let's just see what's +happening. + +So let's look at the chemical +potentials. + +In ideal liquid mixtures. + +So everything is derived from +the fact that when we have any + +of the constituents in both +phases, the chemical potential + +must be equal in both phases. + +Right? + +So, we can write for A, mu +A of the liquid at some + +temperature and pressure must +equal chemical potential of A + +for the gas. + +That's the partial pressure. + +So if we have an ideal gas, and +certainly if we're going + +to assume an ideal liquid +mixture, we can safely assume + +that it's an ideal +gas above it. + +Then we can write +mu A in the gas. + +Is just mu A naught. + +That's a function of the +temperature plus RT + +log of pA over p0. + +Nothing new here, this is just +our expression for the + +chemical potential in the +gas, with reference + +to a standard potential. + +Usually one bar. + +At whatever the temperature +is. + +And, of course, this is how it +varies as the partial pressure + +of A in the gas phase varies. + +So then we can just write our +expression for the liquid. + +At our temperature and pressure, +it's given by mu + +naught in the gas phase. + +Plus RT log pA over p0. + +So it's the same thing. + +Because I'm just taking +advantage of this equality. + +But of course, this is +an obvious step, + +having written this. + +But is a super important step. + +That's what allows us to do +this treatment in such a + +straightforward way. + +We know a lot about the +chemical potential of + +something in the gas phase. + +Since the gas and liquid are in +equilibrium, therefore we + +know the chemical potential +in the liquid phase too. + +So we can rewrite this by +recognizing that if we just go + +to the limit where we only have +pure liquid A, so pure + +liquid A. Well, in that case, mu +A naught or sorry, mu A in + +the liquid phase, mu A star is +mu A naught in the gas phase. + +Plus RT log pA over p0. + +And so for the mixture, now all +I'm going to do is just + +add and subtract terms. + +So we can write mu A in the +liquid at T and p, right? + +So this is in the case of the +limit of the pure liquid. + +Now we're going to +the mixture. + +So it's just mu A naught plus +RT log pA star over p0 minus + +RT log of pA star over p0. + +Wait a minute, lost a term. + +Plus RT log pA over p0. + +And all I want to do now +is combine terms. + +To write mu A star liquid +temperature and pressure. + +Plus RT log of pA +over pA star. + +So this is a very convenient +form for it. + +And then, of course, we have an +expression for pA, right? + +From Raoult's law. pA +is just the mole + +fraction xA times pA star. + +That's just true for +the ideal mixture. + +So now, finally, we can write +that mu A in the liquid at T + +and p is just given +by mu A star. + +So that's for the pure +liquid at that + +temperature and pressure. + +Plus RT log of the mole fraction +of A. So that's a + +very simple expression for the +chemical potential of A. And + +of course the analogous +expression will hold for any + +of the constituents. + +In an ideal liquid mixture. + +By the way, it's convenient +because it looks just like the + +chemical potential in a mixture +of ideal gases. + +Except that we have liquid +instead of gases, right? + +Now, of course, since this is +a mole fraction, it's always + +between zero and one. + +That means this is always +a negative number. + +So what that means is that the +chemical potential in the + +solution is always lower than +the chemical potential of the + +pure liquid. + +Very important result. + +So it has all sorts of +implications that we'll see. + +One of them is osmotic +pressure. + +It means that if I have a +biological cell, or some + +container with a membrane +through which one of the + +constituents might pass. + +So in other words, the let's +say, component A, maybe it's + +just water. + +It can pass freely, let's say, +from the outside to the inside + +of the cell, or from one side +to another of a membrane. + +And on one side I've just +got pure water. + +And on the other I've got saline +solution or whatever is + +in the cells, right? + +What's the water going to +do in that situation? + +What's going to happen? + +Anybody know? + +So I've got, I just take fresh +cells and plunk them into pure + +water solution. + +What happens? + +Yeah. + +They burst. + +Water rushes in. + +Because the chemical potential +is lower inside. + +It's always lower in solution +than outside. + +So water rushes in, and +the membrane expands. + +Now, if the membrane is +strong enough, at some + +point it may not burst. + +And the pressure might +start to go up. + +Let's say the membrane +is strong enough to + +resist and not burst. + +Eventually, the water won't keep +going in indefinitely. + +That's because it won't be at +the same temperature and + +pressure any more. + +In particular, the pressure +will have changed. + +So you can build up some high +pressure, what's called + +osmotic pressure. + +Because of the fact that at the +same pressure the chemical + +potential of the water's lower +inside the cell or inside the + +enclosure with the membrane. + +So water will keep filling. + +And at some point the chemical +potentials will equalize + +because of the change +in pressure. + +And at that point there'll be +an equilibrium established. + +We'll see that quantitatively +a little bit later. + +OK. + +The other thing to notice is, +this is familiar from the + +expression for a gas mixture. + +What drives the gas mixture? + +Remember back when we discussed +mixing of gases and + +the fact that they +would mix at all. + +What makes that happen? + +What's driving it? + +Yeah, it's entropy, right? + +And that's what's happening +here too. + +Of course, in the case of the +ideal liquid mixture, there's + +no energetic interaction. + +The molecules are +non-interacting in this case. + +But of course, entropy is going +to want them to mix. + +And that's what's +resulting in the + +decrease in chemical potential. + +Let's see that a little more +explicitly by just calculating + +out the free energy +change of mixing. + +So, delta G of mixing. + +So we're going to start with +two separated liquids. + +And then we'll remove +the barrier. + +And we'll have the two +mixed together. + +So of course, the free energy in +either case is just the sum + +of the number of moles of +each times the chemical + +potential of each. + +We have expressions for that. + +So starting G1 in this case. + +It's n of A, number of +moles of A. Times + +the chemical potential. + +So it's xA mu A star +in the liquid. + +Plus nB xB B mu B star +of the liquid. + +Here, G of two. + +After we let them mix. + +Then it's n -- wait a minute. + +It's just n. + +I think I've got that wrong +in the notes also. + +Right, it's just a number of +moles times the chemical + +potential in each case. + +So it's the number of +moles times xA. + +Times mu A in the mixture. + +Plus n xB mu B in the mixture. + +But we've just figured it out +our expressions for mu A and + +mu B, our chemical potentials +of each constituent in the + +ideal liquid mixture. + +So this is just n xA. + +And here's our expression. + +And of course these are +going to cancel. + +Let's write it out. + +So it's mu A star +plus RT log xA. + +And then, mu B star +plus RT log xB. + +So our delta G of mixing +is just the difference + +between these two. + +So it's n RT xA log +xA plus xB log xB. + +Where have you seen +that before? + +Yeah. + +The same thing that you had for +the delta G of mixing for + +an ideal gas mixture. + +Why? + +Because we're not accounting for +any interactions between + +the molecules in either +of the phases. + +And if the molecules aren't +interacting, it's all entropy. + +And the entropy term has the +same form in either case. + +In microscopic terms, it's just +measuring the fact that + +there's more disorder +in the mixture + +than in the pure liquids. + +Just the same it was +in the gas phase. + +OK. + +We can see this even more +explicitly if we just recall + +that G is V dp minus S dT. + +So we can just explicitly +calculate + +the entropy of mixing. + +Delta S of mixing is just the +partial of delta G of mixing. + +Negative partial. + +With respect to temperature. + +At constant pressure. + +So it's just minus n R xA +log xA plus xB log xB. + +So that's our entropy +of mixing. + +We can calculate our +enthalpy of mixing. + +Just delta G of mixing. + +Plus T delta S of mixing. + +But it's immediately apparent +that these are just going to + +cancel when we multiply +this by T. So there's + +no enthalpy of mixing. + +Just as we expect when +there are no + +energetic terms involved. + +It's all entropy that's +driving the mixture. + +One more detail, it's +straightforward to see that + +there's no volume change. + +That is, if we take the +derivative of delta G of + +mixing the partial derivative +with respect to pressure, at + +constant temperature, of course, +there's no explicit + +pressure dependence. + +This is zero. + +So again, in the ideal liquid +mixture case, their molecules + +aren't interacting. + +So there's no reason, when I +open that barrier, that the + +amount of volume they occupy +altogether is going to change. + +Any questions, so far? + +OK. + +Then, let's move on to +non-ideal solutions. + +By the way, just to return +briefly to this topic of + +osmotic pressure, I just want +to emphasize that result + +didn't need any kind of energy +of mixing, either, right? + +Just from the entropy +term you would burst + +the cell or do whatever. + +You end up with a +larger pressure. + +So in other words, if you have +a situation where, here is A, + +pure liquid. + +And here is A plus B liquid, so +mu A star is greater than + +mu A. We know that in all cases +at the same pressure, + +the chemical potential of the +mixture is lower than the + +chemical potential of +the pure liquid. + +What's going to happen? + +Well, A is going to, oh, +sorry, A over here is + +going to rush in. + +It's going to get through +this, if I've got a + +semi-permeable membrane, it's +permeable to A but not to B. + +Common situation, of course. + +That's certainly the case +for the cell membrane. + +Water may flow easily in through +the membrane, but all + +of the stuff, all the salt and +everything else that's inside + +the cell generally won't. + +So of course A then flows +through this, what's called a + +semi-permeable membrane. + +And you'll wind up with either a +burst membrane, or something + +that looks like this. + +Where now there is additional +pressure here. + +And you'll have some different +mole fraction than you started + +with before. + +Now let's go over to non-ideal +solutions. + +So let's just think +microscopically for a moment + +about how this is +going to work. + +You know, normally, always, +there are interactions between + +the molecules and the liquid. + +The liquid is a condensed +phase. + +The molecules are in immediate +proximity to each other. + +So it's very different from the +gas phase, where it can be + +a pretty realistic approximation +to say, well, + +the molecules are essentially +non-interacting. + +The ideal gas law may turn +out to be a very good + +approximation. + +In the liquid, really, it's +never the case that you don't + +have interactions. + +So if we just sketch that. + +If we start with a bunch of +molecules in A, they're + +interacting. + +So there's some interaction +energy. + +I'll call it AA, it's the +interaction between two + +molecules of A. In most cases +it'll be less than zero. + +That is, there'd be +a weak attraction. + +Same thing between +molecules of B. + +So that's my situation in +the separated liquids. + +I've got molecules in +each container. + +They're interacting. + +There's some energy associated +with that. + +So here's the pure separated +liquids. + +And now, I'll open up +the barrier and + +let the liquids mix. + +And now suddenly, of course, A +and B are going to interact + +with each other as well +as other molecules + +of their own kind. + +So now, suddenly, there's going +to be some interaction + +energy. uAB. + +And very simplistically, we can +envision that for some of + +the molecules, essentially, +there would be + +exchange of this sort. + +So, one neighbor of this +molecule and one neighbor of + +this molecule will wind up +exchanged for some pairs of + +molecules with the +unlike species. + +And essentially, likes +interactions will be replaced + +by unlike interactions. + +So there's some now change +in energy involved. + +There's a delta u. + +And as outlined in this simple +picture, it's just 2 uAB minus + +uAA plus uBB. + +Real liquids are very +complicated. + +For liquids with relatively +simple non-directional + +interactions, things like +organic liquids that might + +interact van der Waal's +interactions. + +This might be a reasonable +starting point. + +And in general, if we're going +to deal with relatively small + +deviations from the ideal liquid +mixture, the ideal + +solution, then we can start +with a model like this. + +And this difference is what's +going to determine how far the + +liquid mixture will deviate from +the ideal solution case. + +Of course, we could always just +write a term like this. + +It may or may not be easily +expressed in this sort of way. + +So let's just think about what +the possibilities are. + +Of course, simply, +there are two. + +The sign could be positive +or negative. + +And what that means is, you +could have situations where + +it's positive because basically +there's an energy of + +mixing now in these cases. + +If that's not zero, unlike the +ideal case, now unlike before, + +where we just had entropy +driving the mixture, now + +there's an energy of mixing. + +Could be positive or negative. + +If it's positive, that means +energetically speaking, the + +mixture is unfavorable. + +In other words, the +intermolecular interactions + +between like molecules are +more favorable then the + +interactions between the unlike + +molecules, in that case. + +So, delta u is greater +than zero. + +And our delta H of mixing +is going to be close + +to delta u of mixing. + +That is, we're going to figure +that delta pV is not going to + +be something large. + +And in that case, we can say +delta G of mixing is 1/4 n. + +And that's only because there +are 4 species involved here. + +Times delta u. + +In other words, I'm +multiplying this + +molecular delta u. + +This is the change in +energy for this + +collection of four molecules. + +Or of four molecular pairs. + +Plus the other stuff that we've +seen for the ideal case. + +That is, the entropy term, of +course, is still there. xA log + +xA plus xB log xB. + +And because we're treating the +case where this is positive, + +that means this is bigger than +in the ideal solution case. + +So of course there are lots of +examples of each of these. + +In fact, this is the more +common deviation. + +So, and lots of examples. + +An easy one is acetone. + +And carbon disulfide. + +So, if we look at that, and +just see what the phase + +diagram is going to look like, +it's the following. + +So let's start with +the ideal case. + +So I'm going to make B the +more volatile component. + +That is, B is going to be CS2. + +So here's p star CS2, which +I'll call p star B. And + +somewhere down here will be p +star for A, that is, p star + +for acetone. + +And this is going to be the +mole fraction of CS2. + +Or xB. + +So let's start with +the ideal case. + +Not steep enough. + +Pretty good. + +OK. + +And now let's look at +what's going to + +happen in the real mixture. + +Well, because we've got a +positive deviation, what's + +going to happen is the mixing +is unfavorable. + +The molecules aren't +that happy any more + +about being in solution. + +So what that means is, +relative to the ideal + +solution, they'd rather go +up into the gas phase. + +They don't like being +in the mixture. + +Compared to what they would feel +in the ideal solution, + +where there are no +interactions. + +Because the interactions between +unlike molecules are + +unfavorable. + +So what's going to +happen, then, is + +the pressure is higher. + +You have deviations from +the ideal case, + +in the total pressure. + +And in each of the individual +partial pressures. + +That's the total pressure. +pA plus pB. + +In the ideal case it's +this straight line. + +In the non-ideal case, though, +it's bigger than + +the straight line. + +Because more stuff wants to +get up into the gas phase. + +And it's the same for each +individual component. + +So here's pA. + +And there's pB. + +Any questions? + +OK, so it's obvious just from +looking at this that each of + +the partial pressures +is bigger than it is + +in the ideal case. + +And so, so is the +total pressure. + +So in other words, if I say +what's the partial pressure of + +CS2, well, since it's not the +simple ideal case, actually I + +don't know what it +is in general. + +It's not easy to calculate a +priori what it's going to do + +all the way across the phase +diagram for any mole fraction. + +What I do know, though, is it's +bigger than it would be + +for the ideal solution case. + +In other words, it's bigger than +x CS2 times p star CS2, + +the pressure over the +pure liquid CS2. + +Same for acetone. + +It's bigger than x acetone +p star acetone. + +And since both partial pressures +are bigger, the + +total pressure has +to be bigger. + +And of course, that's something +you can read right + +off the diagram as well. + +In other words, the total +pressure is bigger than in the + +ideal solution case. + +Any questions? + +OK. + +So the negative case, +of course, + +is exactly the opposite. + +So I'll just go through +it quickly. + +So, remember positive deviations +came, let's put + +this back up there. + +That came from the case where +the unlike intermolecular + +interactions are not +as favorable. + +There's less attraction, more +repulsion than in this case. + +Of course, there are plenty of +cases of the opposite sort. + +Where the unlike intermolecular +interactions + +are attractive. + +More than the interactions +between like molecules. + +And in that case, you have +the opposite result. + +So you can have negative +deviations. + +In other words, delta +u is less than zero. + +Lots of examples. + +I've got one in the notes, +it's just acetone and + +chloroform. + +So if we get rid of the carbon +disulfide and put CHCl3 in + +there, that's more favorable. + +Because there's weak +hydrogen bonding + +between the unlike species. + +And not between the +like species. + +So what happens is, you have +acetone, it's this. + +And you have chloroform. + +And there's weak hydrogen +bonding between them. + +There's an attraction there. + +That doesn't exist +between either + +case of the like molecules. + +So now there's stronger +attraction between them than + +there is between molecules +in either of + +the pure liquid cases. + +So, of course, you know +that the opposite + +result is going to happen. + +In this case, now you mix them +together, relative to the + +ideal solution where there are +no interactions, now they want + +to be together. + +They're clinging to each other +through these hydrogen bonds. + +What's that mean for the +pressure up in the gas phase, + +in the solution? + +They don't want to go +there any more. + +Stuff in the gas phase now wants +to condense down into + +the liquid. + +Because there they have +favorable interactions. + +So that's, of course, +what'll happen. + +And so then you just see the +opposite sort of deviation + +from what I just illustrated +before. + +So then if we look at +p star CHCl3, where + +are these lines going? + +Well, may have been +more artistic. + +But I'm afraid I'm going to +have to go with reality. + +p star for acetone. + +There's chloroform. + +And now our deviation +is going to be in + +the opposite direction. + +So all the, both of the partial +pressures and the + +total pressure are going to go +lower than indicated here. + +So p total is now less than, +for the real case, is less + +than p total for +the ideal case. + +In the situation where you have +attractive interactions + +between the unlike molecules. + +Any questions? + +OK. + +Now, in general, this +is complicated. + +To describe quantitatively +throughout the + +entire phase diagram. + +The interactions are +complicated. + +Lots of times, molecules +interact with + +more than one neighbor. + +So in general, we don't have a +simple analytical expression + +for what the pressure is going +to do as a function of mole + +fraction all the way +from zero to one. + +Of course, we have it +in very simple form + +for the ideal solution. + +Because everything's linear. + +So it's very simple. + +These are replaced by equalities +and we know + +everything. + +Now we don't. + +But we can at least make some +progress by looking at the + +limiting cases. + +Where you have just very +dilute solutions. + +So in that case, you +can anticipate + +what's going to happen. + +So let's say we mix A and B. +And one of them is in very + +dilute concentration. + +For the other one, for B, most +molecules of B are just going + +to see themselves. + +They hardly know that +you've mixed any + +molecules of A in there. + +For them, it's pretty much +an ideal solution. + +They think they're in +an ideal solution. + +Which is to say there's an +entropy change in mixing. + +But hardly any of them +experience interactions with + +the unlike molecules. + +For the dilute molecules, +there is a change. + +You can't use Raoult's +law any more. + +But at least we can look of +the slope of the curve and + +say, OK, at least in the dilute +solution case for a + +little while it's going +to be linear. + +We can understand it. + +We can tabulate it. + +So let's look at +how that works. + +Alright. + +That limit is something that has +a name, that's called the + +ideal dilute solution. + +Not to be confused with +the ideal solution. + +Where both constituents +follow Raoult's law, + +as we've seen before. + +So ideal dilute solution. + +We're going to just look +at these limits. + +So, if we start with the ideal +case, so let's imagine we're + +going to look at carbon +disulfide again. + +Here's p star CS2, which +is our pB star. + +And this is x CS2, or xB. + +OK, well, what happens +if we've got + +almost pure carbon disulfide. + +Well, what's going to happen is +in this limit, like I was + +mentioning, up here the CS2 +pretty much sees other CS2. + +It thinks it's in an +ideal solution. + +It's going to look like that. + +Now, let's go to the +other limit. + +So this is the limit x CS2 +equals xB approaches one. + +Raoult's law. + +Two, the other limit. x +CS2 approaches zero. + +We're down here. + +So it's definitely not +going to be the same. + +Because now, every molecule, +every CS2 molecule, is + +completely surrounded +by acetone. + +So they all feel the +energy of mixing. + +Because there are hardly +any of them there. + +So every one of them is, it's +very rare for one to find a + +neighbor of its own kind. + +And this is a case where there's +a positive deviation + +from ideality. + +That is, the interactions +are less favorable + +between unlike species. + +So, it's up here. + +Doesn't like that. + +It says, get me out here, I'd +much rather be in the gas + +phase, compared to the ideal +case, then surrounded by all + +these acetone molecules, +right? + +So that's what'll happen. + +And now it's up to the artist. + +But in some way there's +going to be a set + +of values in between. + +And the ideal dilute solution by +itself isn't going to tell + +us about that. + +It's telling us about +the two limits. + +Now, if we follow this, +and I can see I'm + +going to be in trouble. + +But I can do a little creative +bending of the line here. + +If I follow this slope +up to here, + +it'll intercept somewhere. + +That has a name. + +It's called the Henry's +law constant. + +I can write it as +K CS2, or KB. + +So the point is, that at +least for some range of + +concentrations, the variation +is linear. + +And what that means is, if +I know this Henry's law + +constant, for CS2 mixed with +acetone specifically, it would + +be different. + +If it's mixed with something +else, right? + +Other kinds of interactions with +different energies will + +have a different slope. + +But if I know that number, +it's still useful. + +Because at least for that pair +of constituents, I know the + +dependents for some range +of concentrations. + +So this is Henry's +law. p CS -- + +Oops, CS2 is x CS2 +times K CS2. + +Not quite as convenient +as Raoult's law. + +That number, I don't need +to know what the other + +constituent is. + +It's just a property of CS2. + +It depends on the temperature, +but not the other member of + +the mixture. + +This one does, but still there's +at least a substantial + +number of these things +tabulated. + +Especially for important +mixtures. + +So it becomes useful for +dilute solutions. + +And there's an awful +lot of chemistry. + +There's an awful lot of biology +that happens in + +relatively dilute solutions. + +OK. + +I'll leave it at this point. + +Next time we'll look at the +total phase diagram, just like + +we did last time looking at +both the liquid and gas + +coexistence curves, and seeing +what the behavior is as a + +function of mole fractions. + +And we'll talk about +distillation and so forth in + +non-ideal liquids. \ No newline at end of file diff --git a/fQcJNoe-q-s.txt b/fQcJNoe-q-s.txt new file mode 100644 index 0000000000000000000000000000000000000000..d5a7b9d398f546608695745fbce2408fe463fa58 --- /dev/null +++ b/fQcJNoe-q-s.txt @@ -0,0 +1,8123 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi my name is Harry balakrishnan I'm + + align:start position:0% +hi my name is Harry balakrishnan I'm + + + align:start position:0% +hi my name is Harry balakrishnan I'm +your replacement professor you guys know + + align:start position:0% +your replacement professor you guys know + + + align:start position:0% +your replacement professor you guys know +what replacement referees so on the + + align:start position:0% +what replacement referees so on the + + + align:start position:0% +what replacement referees so on the +other professor in the class and I + + align:start position:0% +other professor in the class and I + + + align:start position:0% +other professor in the class and I +generally not with materials that's a + + align:start position:0% +generally not with materials that's a + + + align:start position:0% +generally not with materials that's a +little bit later but what we thought + + align:start position:0% +little bit later but what we thought + + + align:start position:0% +little bit later but what we thought +we'd do today is to talk about this + + align:start position:0% +we'd do today is to talk about this + + + align:start position:0% +we'd do today is to talk about this +audio com library so before I get + + align:start position:0% +audio com library so before I get + + + align:start position:0% +audio com library so before I get +started and show you how to use this and + + align:start position:0% +started and show you how to use this and + + + align:start position:0% +started and show you how to use this and +all the different ways in which things + + align:start position:0% +all the different ways in which things + + + align:start position:0% +all the different ways in which things +will break because it's something in the + + align:start position:0% +will break because it's something in the + + + align:start position:0% +will break because it's something in the +real world let me see a show of hands + + align:start position:0% +real world let me see a show of hands + + + align:start position:0% +real world let me see a show of hands +how many people have tried to install or + + align:start position:0% +how many people have tried to install or + + + align:start position:0% +how many people have tried to install or +run or do something with it okay how + + align:start position:0% +run or do something with it okay how + + + align:start position:0% +run or do something with it okay how +many people have sort of don't have any + + align:start position:0% +many people have sort of don't have any + + + align:start position:0% +many people have sort of don't have any +idea what I'm talking about okay and how + + align:start position:0% +idea what I'm talking about okay and how + + + align:start position:0% +idea what I'm talking about okay and how +many people have managed to get + + align:start position:0% +many people have managed to get + + + align:start position:0% +many people have managed to get +something to work by work it's if you + + align:start position:0% +something to work by work it's if you + + + align:start position:0% +something to work by work it's if you +got the preamble to decode it means + + align:start position:0% +got the preamble to decode it means + + + align:start position:0% +got the preamble to decode it means +something is working alright how many + + align:start position:0% +something is working alright how many + + + align:start position:0% +something is working alright how many +people would got nothing okay well it'll + + align:start position:0% +people would got nothing okay well it'll + + + align:start position:0% +people would got nothing okay well it'll +all work it's just a question of + + align:start position:0% +all work it's just a question of + + + align:start position:0% +all work it's just a question of +figuring out how to get it to work okay + + align:start position:0% +figuring out how to get it to work okay + + + align:start position:0% +figuring out how to get it to work okay +so here's the story in order to do + + align:start position:0% +so here's the story in order to do + + + align:start position:0% +so here's the story in order to do +something practical with all the theory + + align:start position:0% +something practical with all the theory + + + align:start position:0% +something practical with all the theory +that you're learning it's important to + + align:start position:0% +that you're learning it's important to + + + align:start position:0% +that you're learning it's important to +try to implement something now the + + align:start position:0% +try to implement something now the + + + align:start position:0% +try to implement something now the +theory we're learning applies to a wide + + align:start position:0% +theory we're learning applies to a wide + + + align:start position:0% +theory we're learning applies to a wide +range of communication channels it + + align:start position:0% +range of communication channels it + + + align:start position:0% +range of communication channels it +applies to radio it applies to wired + + align:start position:0% +applies to radio it applies to wired + + + align:start position:0% +applies to radio it applies to wired +links you know ethernet or cables it + + align:start position:0% +links you know ethernet or cables it + + + align:start position:0% +links you know ethernet or cables it +applies to optical links like infrared + + align:start position:0% +applies to optical links like infrared + + + align:start position:0% +applies to optical links like infrared +or you know free space optical links and + + align:start position:0% +or you know free space optical links and + + + align:start position:0% +or you know free space optical links and +it also applies to audio + + align:start position:0% +it also applies to audio + + + align:start position:0% +it also applies to audio +and we've decided to use audio as the + + align:start position:0% +and we've decided to use audio as the + + + align:start position:0% +and we've decided to use audio as the +vehicle to bring these ideas into the + + align:start position:0% +vehicle to bring these ideas into the + + + align:start position:0% +vehicle to bring these ideas into the +lab for two reasons the first and most + + align:start position:0% +lab for two reasons the first and most + + + align:start position:0% +lab for two reasons the first and most +important reason is that it turns out + + align:start position:0% +important reason is that it turns out + + + align:start position:0% +important reason is that it turns out +it's the easiest piece of hardware it's + + align:start position:0% +it's the easiest piece of hardware it's + + + align:start position:0% +it's the easiest piece of hardware it's +the most convenient piece of hardware + + align:start position:0% +the most convenient piece of hardware + + + align:start position:0% +the most convenient piece of hardware +that everybody has access to all you + + align:start position:0% +that everybody has access to all you + + + align:start position:0% +that everybody has access to all you +actually need is a computer with a + + align:start position:0% +actually need is a computer with a + + + align:start position:0% +actually need is a computer with a +microphone and speaker and in fact I + + align:start position:0% +microphone and speaker and in fact I + + + align:start position:0% +microphone and speaker and in fact I +would imagine that in the next couple of + + align:start position:0% +would imagine that in the next couple of + + + align:start position:0% +would imagine that in the next couple of +years it will run on this thing too so + + align:start position:0% +years it will run on this thing too so + + + align:start position:0% +years it will run on this thing too so +you could write apps on this that will + + align:start position:0% +you could write apps on this that will + + + align:start position:0% +you could write apps on this that will +make this work already we have stopped + + align:start position:0% +make this work already we have stopped + + + align:start position:0% +make this work already we have stopped +working on on an Android and iPhone to + + align:start position:0% +working on on an Android and iPhone to + + + align:start position:0% +working on on an Android and iPhone to +do much of the stuff so the first one is + + align:start position:0% +do much of the stuff so the first one is + + + align:start position:0% +do much of the stuff so the first one is +just it's everywhere everybody has it + + align:start position:0% +just it's everywhere everybody has it + + + align:start position:0% +just it's everywhere everybody has it +you don't have to do anything special to + + align:start position:0% +you don't have to do anything special to + + + align:start position:0% +you don't have to do anything special to +get it the second is that it turns out + + align:start position:0% +get it the second is that it turns out + + + align:start position:0% +get it the second is that it turns out +it actually illustrates many of the + + align:start position:0% +it actually illustrates many of the + + + align:start position:0% +it actually illustrates many of the +problems that we're talking about noise + + align:start position:0% +problems that we're talking about noise + + + align:start position:0% +problems that we're talking about noise +and this idea of how linear + + align:start position:0% +and this idea of how linear + + + align:start position:0% +and this idea of how linear +time-invariant systems an understanding + + align:start position:0% +time-invariant systems an understanding + + + align:start position:0% +time-invariant systems an understanding +of linear time-invariant systems applies + + align:start position:0% +of linear time-invariant systems applies + + + align:start position:0% +of linear time-invariant systems applies +to what we're trying to be billed to + + align:start position:0% +to what we're trying to be billed to + + + align:start position:0% +to what we're trying to be billed to +communication channels and how you use + + align:start position:0% +communication channels and how you use + + + align:start position:0% +communication channels and how you use +the ideas you've learned about LTI + + align:start position:0% +the ideas you've learned about LTI + + + align:start position:0% +the ideas you've learned about LTI +systems to improve the performance of + + align:start position:0% +systems to improve the performance of + + + align:start position:0% +systems to improve the performance of +whatever you implement + + align:start position:0% + + + + align:start position:0% + +I'm going to restrict myself to this + + align:start position:0% +I'm going to restrict myself to this + + + align:start position:0% +I'm going to restrict myself to this +audio comm system but it you know these + + align:start position:0% +audio comm system but it you know these + + + align:start position:0% +audio comm system but it you know these +ideas apply across the board so let me + + align:start position:0% +ideas apply across the board so let me + + + align:start position:0% +ideas apply across the board so let me +tell you how this system does its job + + align:start position:0% +tell you how this system does its job + + + align:start position:0% +tell you how this system does its job +and this goes back to what Professor + + align:start position:0% +and this goes back to what Professor + + + align:start position:0% +and this goes back to what Professor +Fergie's was telling you before + + align:start position:0% +Fergie's was telling you before + + + align:start position:0% +Fergie's was telling you before +ultimately all of the information is + + align:start position:0% +ultimately all of the information is + + + align:start position:0% +ultimately all of the information is +modulated on top of a carrier and a + + align:start position:0% +modulated on top of a carrier and a + + + align:start position:0% +modulated on top of a carrier and a +carriers as you as you know a sinusoid + + align:start position:0% + + + + align:start position:0% + +so time goes this way and this is the + + align:start position:0% +so time goes this way and this is the + + + align:start position:0% +so time goes this way and this is the +amplitude or which we also call the + + align:start position:0% +amplitude or which we also call the + + + align:start position:0% +amplitude or which we also call the +voltage such a time varying waveform + + align:start position:0% + + + + align:start position:0% + +what your receiver is capable so the + + align:start position:0% +what your receiver is capable so the + + + align:start position:0% +what your receiver is capable so the +transmitter is capable of generating + + align:start position:0% +transmitter is capable of generating + + + align:start position:0% +transmitter is capable of generating +these kinds of waveforms at different + + align:start position:0% +these kinds of waveforms at different + + + align:start position:0% +these kinds of waveforms at different +frequencies so this might be for example + + align:start position:0% +frequencies so this might be for example + + + align:start position:0% +frequencies so this might be for example +1 kilohertz a 1000 Hertz we can go up to + + align:start position:0% +1 kilohertz a 1000 Hertz we can go up to + + + align:start position:0% +1 kilohertz a 1000 Hertz we can go up to +you know I've got mine to work up to 20 + + align:start position:0% +you know I've got mine to work up to 20 + + + align:start position:0% +you know I've got mine to work up to 20 +kilohertz which is fortunate because I + + align:start position:0% +kilohertz which is fortunate because I + + + align:start position:0% +kilohertz which is fortunate because I +can't hear it and you know it does a + + align:start position:0% +can't hear it and you know it does a + + + align:start position:0% +can't hear it and you know it does a +wide range of frequencies this could + + align:start position:0% +wide range of frequencies this could + + + align:start position:0% +wide range of frequencies this could +work in in the lab I found that things + + align:start position:0% +work in in the lab I found that things + + + align:start position:0% +work in in the lab I found that things +tend to work between 1 kilohertz and + + align:start position:0% +tend to work between 1 kilohertz and + + + align:start position:0% +tend to work between 1 kilohertz and +only about three or four kilos so that's + + align:start position:0% +only about three or four kilos so that's + + + align:start position:0% +only about three or four kilos so that's +the range when talking about so you pick + + align:start position:0% +the range when talking about so you pick + + + align:start position:0% +the range when talking about so you pick +a carrier wave form for your + + align:start position:0% +a carrier wave form for your + + + align:start position:0% +a carrier wave form for your +transmission what the receivers capable + + align:start position:0% +transmission what the receivers capable + + + align:start position:0% +transmission what the receivers capable +of doing is it's a digital receiver so + + align:start position:0% +of doing is it's a digital receiver so + + + align:start position:0% +of doing is it's a digital receiver so +what it's capable of doing is receiving + + align:start position:0% +what it's capable of doing is receiving + + + align:start position:0% +what it's capable of doing is receiving +data receiving signals from the sound + + align:start position:0% +data receiving signals from the sound + + + align:start position:0% +data receiving signals from the sound +card at a certain number of samples per + + align:start position:0% +card at a certain number of samples per + + + align:start position:0% +card at a certain number of samples per +second we're going to call that the + + align:start position:0% +second we're going to call that the + + + align:start position:0% +second we're going to call that the +sampling rate we've used the term we've + + align:start position:0% +sampling rate we've used the term we've + + + align:start position:0% +sampling rate we've used the term we've +used the storm before the sampling rate + + align:start position:0% + + + + align:start position:0% + +can be anything by default in the system + + align:start position:0% +can be anything by default in the system + + + align:start position:0% +can be anything by default in the system +we pick the highest possible sampling + + align:start position:0% +we pick the highest possible sampling + + + align:start position:0% +we pick the highest possible sampling +rate of 48 kilohertz in some cases you + + align:start position:0% +rate of 48 kilohertz in some cases you + + + align:start position:0% +rate of 48 kilohertz in some cases you +might have to yank it down you might + + align:start position:0% +might have to yank it down you might + + + align:start position:0% +might have to yank it down you might +have to go as low as 8 kilohertz but 48 + + align:start position:0% +have to go as low as 8 kilohertz but 48 + + + align:start position:0% +have to go as low as 8 kilohertz but 48 +kilohertz seems to work in the lab it + + align:start position:0% +kilohertz seems to work in the lab it + + + align:start position:0% +kilohertz seems to work in the lab it +works on a bunch of machines that I've + + align:start position:0% +works on a bunch of machines that I've + + + align:start position:0% +works on a bunch of machines that I've +looked at so we have tokens we have the + + align:start position:0% +looked at so we have tokens we have the + + + align:start position:0% +looked at so we have tokens we have the +1 kilohertz which is the carrier wave + + align:start position:0% +1 kilohertz which is the carrier wave + + + align:start position:0% +1 kilohertz which is the carrier wave +form will use the notation MC and we can + + align:start position:0% +form will use the notation MC and we can + + + align:start position:0% +form will use the notation MC and we can +receive samples at 48 kilohertz and + + align:start position:0% +receive samples at 48 kilohertz and + + + align:start position:0% +receive samples at 48 kilohertz and +that's how the transmitter also when it + + align:start position:0% +that's how the transmitter also when it + + + align:start position:0% +that's how the transmitter also when it +wants to send stuff only on the air it + + align:start position:0% +wants to send stuff only on the air it + + + align:start position:0% +wants to send stuff only on the air it +picks a sampling rate it's going to pick + + align:start position:0% +picks a sampling rate it's going to pick + + + align:start position:0% +picks a sampling rate it's going to pick +48 kilohertz the receiver and sender + + align:start position:0% +48 kilohertz the receiver and sender + + + align:start position:0% +48 kilohertz the receiver and sender +need to agree on the sampling rate what + + align:start position:0% +need to agree on the sampling rate what + + + align:start position:0% +need to agree on the sampling rate what +happens then is very straightforward if + + align:start position:0% +happens then is very straightforward if + + + align:start position:0% +happens then is very straightforward if +you have a carrier wave form that looks + + align:start position:0% +you have a carrier wave form that looks + + + align:start position:0% +you have a carrier wave form that looks +like this what 1 kilohertz means is that + + align:start position:0% +like this what 1 kilohertz means is that + + + align:start position:0% +like this what 1 kilohertz means is that +we do this cycle a thousand times a + + align:start position:0% +we do this cycle a thousand times a + + + align:start position:0% +we do this cycle a thousand times a +second which means that one period of + + align:start position:0% +second which means that one period of + + + align:start position:0% +second which means that one period of +the cycle is one thousandth of a second + + align:start position:0% +the cycle is one thousandth of a second + + + align:start position:0% +the cycle is one thousandth of a second +or one millisecond + + align:start position:0% + + + + align:start position:0% + +now if I sample this at 48,000 or 48 + + align:start position:0% +now if I sample this at 48,000 or 48 + + + align:start position:0% +now if I sample this at 48,000 or 48 +kilohertz or 48,000 times a second in + + align:start position:0% +kilohertz or 48,000 times a second in + + + align:start position:0% +kilohertz or 48,000 times a second in +one of these periods how many samples do + + align:start position:0% +one of these periods how many samples do + + + align:start position:0% +one of these periods how many samples do +I get this is where you have to tell me + + align:start position:0% +I get this is where you have to tell me + + + align:start position:0% +I get this is where you have to tell me +something shoot sorry 48 great so I + + align:start position:0% +something shoot sorry 48 great so I + + + align:start position:0% +something shoot sorry 48 great so I +sample it forty thousand times a second + + align:start position:0% +sample it forty thousand times a second + + + align:start position:0% +sample it forty thousand times a second +each of these things as one thousandth + + align:start position:0% +each of these things as one thousandth + + + align:start position:0% +each of these things as one thousandth +of a second so i get 48 what that means + + align:start position:0% +of a second so i get 48 what that means + + + align:start position:0% +of a second so i get 48 what that means +is that we pick a sample here we pick a + + align:start position:0% +is that we pick a sample here we pick a + + + align:start position:0% +is that we pick a sample here we pick a +sample here we pick a sample here 1 2 3 + + align:start position:0% +sample here we pick a sample here 1 2 3 + + + align:start position:0% +sample here we pick a sample here 1 2 3 +4 5 6 7 8 10 12 and we keep going 12 12 + + align:start position:0% +4 5 6 7 8 10 12 and we keep going 12 12 + + + align:start position:0% +4 5 6 7 8 10 12 and we keep going 12 12 +etc so we get 48 okay so if I were to + + align:start position:0% +etc so we get 48 okay so if I were to + + + align:start position:0% +etc so we get 48 okay so if I were to +send a pure sinusoid at the receiver and + + align:start position:0% +send a pure sinusoid at the receiver and + + + align:start position:0% +send a pure sinusoid at the receiver and +this and the way the sinusoid is + + align:start position:0% +this and the way the sinusoid is + + + align:start position:0% +this and the way the sinusoid is +transmitted is by providing these + + align:start position:0% +transmitted is by providing these + + + align:start position:0% +transmitted is by providing these +samples each sample being equal to this + + align:start position:0% +samples each sample being equal to this + + + align:start position:0% +samples each sample being equal to this +voltage value picked from this curve and + + align:start position:0% +voltage value picked from this curve and + + + align:start position:0% +voltage value picked from this curve and +I send each of those samples and each of + + align:start position:0% +I send each of those samples and each of + + + align:start position:0% +I send each of those samples and each of +those in our implementation is a + + align:start position:0% +those in our implementation is a + + + align:start position:0% +those in our implementation is a +floating point number okay like a 32-bit + + align:start position:0% +floating point number okay like a 32-bit + + + align:start position:0% +floating point number okay like a 32-bit +floating point number I pick a number + + align:start position:0% +floating point number I pick a number + + + align:start position:0% +floating point number I pick a number +here 0 and then I pick something here + + align:start position:0% +here 0 and then I pick something here + + + align:start position:0% +here 0 and then I pick something here +which is the sign the value of the + + align:start position:0% +which is the sign the value of the + + + align:start position:0% +which is the sign the value of the +sinusoid at this point in time and this + + align:start position:0% +sinusoid at this point in time and this + + + align:start position:0% +sinusoid at this point in time and this +and this and this and all the way down + + align:start position:0% +and this and this and all the way down + + + align:start position:0% +and this and this and all the way down +and I send those samples the receiver is + + align:start position:0% +and I send those samples the receiver is + + + align:start position:0% +and I send those samples the receiver is +going to be listening at 48 kilohertz + + align:start position:0% +going to be listening at 48 kilohertz + + + align:start position:0% +going to be listening at 48 kilohertz +and picking up whatever it's getting on + + align:start position:0% +and picking up whatever it's getting on + + + align:start position:0% +and picking up whatever it's getting on +the audio channel and that's what it's + + align:start position:0% +the audio channel and that's what it's + + + align:start position:0% +the audio channel and that's what it's +going to be are assuming that's what + + align:start position:0% +going to be are assuming that's what + + + align:start position:0% +going to be are assuming that's what +it's going to assume was sent of course + + align:start position:0% +it's going to assume was sent of course + + + align:start position:0% +it's going to assume was sent of course +in the real world if I stand at one vote + + align:start position:0% +in the real world if I stand at one vote + + + align:start position:0% +in the real world if I stand at one vote +what might be received is point 01 volt + + align:start position:0% +what might be received is point 01 volt + + + align:start position:0% +what might be received is point 01 volt +so point two words or whatever because + + align:start position:0% +so point two words or whatever because + + + align:start position:0% +so point two words or whatever because +signals may in fact lose amplitude as + + align:start position:0% +signals may in fact lose amplitude as + + + align:start position:0% +signals may in fact lose amplitude as +you transmit them over the air so that's + + align:start position:0% +you transmit them over the air so that's + + + align:start position:0% +you transmit them over the air so that's +the overall context so I'm going to + + align:start position:0% +the overall context so I'm going to + + + align:start position:0% +the overall context so I'm going to +start by showing you a few things here + + align:start position:0% + + + + align:start position:0% + +the first thing I'll show is this graph + + align:start position:0% +the first thing I'll show is this graph + + + align:start position:0% +the first thing I'll show is this graph +or program that actually is part of the + + align:start position:0% +or program that actually is part of the + + + align:start position:0% +or program that actually is part of the +package but you need some gtk toolkit + + align:start position:0% +package but you need some gtk toolkit + + + align:start position:0% +package but you need some gtk toolkit +for this to work so we're not record we + + align:start position:0% +for this to work so we're not record we + + + align:start position:0% +for this to work so we're not record we +don't you don't need this for the lab + + align:start position:0% +don't you don't need this for the lab + + + align:start position:0% +don't you don't need this for the lab +but this is just a useful test if I + + align:start position:0% +but this is just a useful test if I + + + align:start position:0% +but this is just a useful test if I +transmit a waveform this program assumes + + align:start position:0% +transmit a waveform this program assumes + + + align:start position:0% +transmit a waveform this program assumes +that I'm transmitting data at 1 + + align:start position:0% +that I'm transmitting data at 1 + + + align:start position:0% +that I'm transmitting data at 1 +kilohertz if I send data at 1 kilohertz + + align:start position:0% +kilohertz if I send data at 1 kilohertz + + + align:start position:0% +kilohertz if I send data at 1 kilohertz +and this is a pure sinusoid let me do + + align:start position:0% +and this is a pure sinusoid let me do + + + align:start position:0% +and this is a pure sinusoid let me do +that I'll explain these parameters in a + + align:start position:0% +that I'll explain these parameters in a + + + align:start position:0% +that I'll explain these parameters in a +big + + align:start position:0% + + + + align:start position:0% + +you can see that what's going on here is + + align:start position:0% +you can see that what's going on here is + + + align:start position:0% +you can see that what's going on here is +if I'm silent + + align:start position:0% +if I'm silent + + + align:start position:0% +if I'm silent +the points get demodulated at plus 1 and + + align:start position:0% +the points get demodulated at plus 1 and + + + align:start position:0% +the points get demodulated at plus 1 and +minus 1 that correspond to the top and + + align:start position:0% +minus 1 that correspond to the top and + + + align:start position:0% +minus 1 that correspond to the top and +the bottom of the waveform and if I make + + align:start position:0% +the bottom of the waveform and if I make + + + align:start position:0% +the bottom of the waveform and if I make +a noise the effects of noise get visible + + align:start position:0% +a noise the effects of noise get visible + + + align:start position:0% +a noise the effects of noise get visible +and in fact you can see that sometimes + + align:start position:0% +and in fact you can see that sometimes + + + align:start position:0% +and in fact you can see that sometimes +the guy on the left goes to the right + + align:start position:0% +the guy on the left goes to the right + + + align:start position:0% +the guy on the left goes to the right +and vice versa okay so that's actually a + + align:start position:0% +and vice versa okay so that's actually a + + + align:start position:0% +and vice versa okay so that's actually a +very visual effect of what noise does to + + align:start position:0% +very visual effect of what noise does to + + + align:start position:0% +very visual effect of what noise does to +your transmission i'm going to show this + + align:start position:0% +your transmission i'm going to show this + + + align:start position:0% +your transmission i'm going to show this +again i'm going to do this again so you + + align:start position:0% +again i'm going to do this again so you + + + align:start position:0% +again i'm going to do this again so you +can see what's going on as the amount of + + align:start position:0% +can see what's going on as the amount of + + + align:start position:0% +can see what's going on as the amount of +noise increases you can see that you can + + align:start position:0% +noise increases you can see that you can + + + align:start position:0% +noise increases you can see that you can +imagine that what's going on here in the + + align:start position:0% +imagine that what's going on here in the + + + align:start position:0% +imagine that what's going on here in the +signaling this is called bipolar + + align:start position:0% +signaling this is called bipolar + + + align:start position:0% +signaling this is called bipolar +signaling where you might send a bit 0 + + align:start position:0% +signaling where you might send a bit 0 + + + align:start position:0% +signaling where you might send a bit 0 +ad as a particular kind of sinusoid and + + align:start position:0% +ad as a particular kind of sinusoid and + + + align:start position:0% +ad as a particular kind of sinusoid and +a bit one at the other way as the other + + align:start position:0% +a bit one at the other way as the other + + + align:start position:0% +a bit one at the other way as the other +kind so the idea would be that the zeros + + align:start position:0% +kind so the idea would be that the zeros + + + align:start position:0% +kind so the idea would be that the zeros +get mapped to the left the ones get + + align:start position:0% +get mapped to the left the ones get + + + align:start position:0% +get mapped to the left the ones get +mapped to the right and as we increase + + align:start position:0% +mapped to the right and as we increase + + + align:start position:0% +mapped to the right and as we increase +the amount of noise you can start to see + + align:start position:0% +the amount of noise you can start to see + + + align:start position:0% +the amount of noise you can start to see +that they cross over and we'll be making + + align:start position:0% +that they cross over and we'll be making + + + align:start position:0% +that they cross over and we'll be making +errors in our estimation + + align:start position:0% + + + + align:start position:0% + +so things are working fine now but as I + + align:start position:0% +so things are working fine now but as I + + + align:start position:0% +so things are working fine now but as I +make noise or as you start talking and + + align:start position:0% +make noise or as you start talking and + + + align:start position:0% +make noise or as you start talking and +you create additional noise we're gonna + + align:start position:0% +you create additional noise we're gonna + + + align:start position:0% +you create additional noise we're gonna +start to see the effects of the noise + + align:start position:0% +start to see the effects of the noise + + + align:start position:0% +start to see the effects of the noise +and this is annoying so I'm going to + + align:start position:0% +and this is annoying so I'm going to + + + align:start position:0% +and this is annoying so I'm going to +turn it off okay so um that's the first + + align:start position:0% +turn it off okay so um that's the first + + + align:start position:0% +turn it off okay so um that's the first +order way in which you determine that + + align:start position:0% +order way in which you determine that + + + align:start position:0% +order way in which you determine that +things are working you don't need to use + + align:start position:0% +things are working you don't need to use + + + align:start position:0% +things are working you don't need to use +the graphing program to do that and this + + align:start position:0% +the graphing program to do that and this + + + align:start position:0% +the graphing program to do that and this +is actually annoying to the eye so let + + align:start position:0% +is actually annoying to the eye so let + + + align:start position:0% +is actually annoying to the eye so let +me turn that off too so you run and and + + align:start position:0% +me turn that off too so you run and and + + + align:start position:0% +me turn that off too so you run and and +the documentation we've given you tells + + align:start position:0% +the documentation we've given you tells + + + align:start position:0% +the documentation we've given you tells +you how you go about step by step + + align:start position:0% +you how you go about step by step + + + align:start position:0% +you how you go about step by step +drawing it about this so let me tell you + + align:start position:0% +drawing it about this so let me tell you + + + align:start position:0% +drawing it about this so let me tell you +what these options mean it's all written + + align:start position:0% +what these options mean it's all written + + + align:start position:0% +what these options mean it's all written +up so you don't have to listen you don't + + align:start position:0% +up so you don't have to listen you don't + + + align:start position:0% +up so you don't have to listen you don't +have to take notes right now everything + + align:start position:0% +have to take notes right now everything + + + align:start position:0% +have to take notes right now everything +is there in that command line the dash + + align:start position:0% +is there in that command line the dash + + + align:start position:0% +is there in that command line the dash +little s 256 refers to the number of + + align:start position:0% +little s 256 refers to the number of + + + align:start position:0% +little s 256 refers to the number of +samples per bit i'll get to that point + + align:start position:0% +samples per bit i'll get to that point + + + align:start position:0% +samples per bit i'll get to that point +in a second the dash capital s 1 means + + align:start position:0% +in a second the dash capital s 1 means + + + align:start position:0% +in a second the dash capital s 1 means +that we send capital S is that kind of + + align:start position:0% +that we send capital S is that kind of + + + align:start position:0% +that we send capital S is that kind of +source you know it's it's it's something + + align:start position:0% +source you know it's it's it's something + + + align:start position:0% +source you know it's it's it's something +about the nature of the source capital S + + align:start position:0% +about the nature of the source capital S + + + align:start position:0% +about the nature of the source capital S +one means that my entire information is + + align:start position:0% +one means that my entire information is + + + align:start position:0% +one means that my entire information is +sent as ones which means i'm selling a + + align:start position:0% +sent as ones which means i'm selling a + + + align:start position:0% +sent as ones which means i'm selling a +pure sinusoidal carrier all i'm doing is + + align:start position:0% +pure sinusoidal carrier all i'm doing is + + + align:start position:0% +pure sinusoidal carrier all i'm doing is +sending the sinusoidal carrier dash g + + align:start position:0% +sending the sinusoidal carrier dash g + + + align:start position:0% +sending the sinusoidal carrier dash g +just means show me some graphs and n + + align:start position:0% +just means show me some graphs and n + + + align:start position:0% +just means show me some graphs and n +refers to the number of bits i wish to + + align:start position:0% +refers to the number of bits i wish to + + + align:start position:0% +refers to the number of bits i wish to +send ok so these are all documented in + + align:start position:0% +send ok so these are all documented in + + + align:start position:0% +send ok so these are all documented in +different to worry about so what we're + + align:start position:0% +different to worry about so what we're + + + align:start position:0% +different to worry about so what we're +going to do now is actually to show you + + align:start position:0% +going to do now is actually to show you + + + align:start position:0% +going to do now is actually to show you +what happens when we transmit some data + + align:start position:0% +what happens when we transmit some data + + + align:start position:0% +what happens when we transmit some data +this is actually the very first task in + + align:start position:0% +this is actually the very first task in + + + align:start position:0% +this is actually the very first task in +the lab you transmit some data and you + + align:start position:0% +the lab you transmit some data and you + + + align:start position:0% +the lab you transmit some data and you +plot what the noise histogram looks like + + align:start position:0% + + + + align:start position:0% + +so what we did was we sent a couple + + align:start position:0% +so what we did was we sent a couple + + + align:start position:0% +so what we did was we sent a couple +hundred bits at some appropriate number + + align:start position:0% +hundred bits at some appropriate number + + + align:start position:0% +hundred bits at some appropriate number +of samples per bit you know the way you + + align:start position:0% +of samples per bit you know the way you + + + align:start position:0% +of samples per bit you know the way you +tell if stops working is that line there + + align:start position:0% +tell if stops working is that line there + + + align:start position:0% +tell if stops working is that line there +if it receives the preamble and there's + + align:start position:0% +if it receives the preamble and there's + + + align:start position:0% +if it receives the preamble and there's +this long preamble I'll explain what + + align:start position:0% +this long preamble I'll explain what + + + align:start position:0% +this long preamble I'll explain what +that word means but if you receive the + + align:start position:0% +that word means but if you receive the + + + align:start position:0% +that word means but if you receive the +preamble it means that stops working if + + align:start position:0% +preamble it means that stops working if + + + align:start position:0% +preamble it means that stops working if +you didn't get the preamble it means + + align:start position:0% +you didn't get the preamble it means + + + align:start position:0% +you didn't get the preamble it means +that it doesn't mean that things are + + align:start position:0% +that it doesn't mean that things are + + + align:start position:0% +that it doesn't mean that things are +completely broken it just means you got + + align:start position:0% +completely broken it just means you got + + + align:start position:0% +completely broken it just means you got +it a little bit more work now we also + + align:start position:0% +it a little bit more work now we also + + + align:start position:0% +it a little bit more work now we also +plot out the signal-to-noise ratio of + + align:start position:0% +plot out the signal-to-noise ratio of + + + align:start position:0% +plot out the signal-to-noise ratio of +the transmission and that shows up there + + align:start position:0% +the transmission and that shows up there + + + align:start position:0% +the transmission and that shows up there +if that signal to noise ratio is + + align:start position:0% +if that signal to noise ratio is + + + align:start position:0% +if that signal to noise ratio is +something like 20 DB or 15 DB things are + + align:start position:0% +something like 20 DB or 15 DB things are + + + align:start position:0% +something like 20 DB or 15 DB things are +fine this system doesn't really work + + align:start position:0% +fine this system doesn't really work + + + align:start position:0% +fine this system doesn't really work +below 15 or 10 decibels it means that + + align:start position:0% +below 15 or 10 decibels it means that + + + align:start position:0% +below 15 or 10 decibels it means that +the signal-to-noise ratio is too low + + align:start position:0% +the signal-to-noise ratio is too low + + + align:start position:0% +the signal-to-noise ratio is too low +which means you either have to yank up + + align:start position:0% +which means you either have to yank up + + + align:start position:0% +which means you either have to yank up +the volume or you have to go to a + + align:start position:0% +the volume or you have to go to a + + + align:start position:0% +the volume or you have to go to a +quieter location or and I'll explain + + align:start position:0% +quieter location or and I'll explain + + + align:start position:0% +quieter location or and I'll explain +this you have to change some of the + + align:start position:0% +this you have to change some of the + + + align:start position:0% +this you have to change some of the +parameters in the program now what is + + align:start position:0% +parameters in the program now what is + + + align:start position:0% +parameters in the program now what is +this graph look like will they know this + + align:start position:0% +this graph look like will they know this + + + align:start position:0% +this graph look like will they know this +for a second for this number of samples + + align:start position:0% +for a second for this number of samples + + + align:start position:0% +for a second for this number of samples +that was the noise distribution at point + + align:start position:0% +that was the noise distribution at point + + + align:start position:0% +that was the noise distribution at point +four four you know you could look at it + + align:start position:0% +four four you know you could look at it + + + align:start position:0% +four four you know you could look at it +and it sort of looks Gaussian it's not + + align:start position:0% +and it sort of looks Gaussian it's not + + + align:start position:0% +and it sort of looks Gaussian it's not +quite a Gaussian explain why in a little + + align:start position:0% +quite a Gaussian explain why in a little + + + align:start position:0% +quite a Gaussian explain why in a little +bit what these pictures show is this is + + align:start position:0% +bit what these pictures show is this is + + + align:start position:0% +bit what these pictures show is this is +what the noise this is what the received + + align:start position:0% +what the noise this is what the received + + + align:start position:0% +what the noise this is what the received +samples look like and it's it has a + + align:start position:0% +samples look like and it's it has a + + + align:start position:0% +samples look like and it's it has a +median a mean value that's in the center + + align:start position:0% +median a mean value that's in the center + + + align:start position:0% +median a mean value that's in the center +and then it's kind of got a shape on + + align:start position:0% +and then it's kind of got a shape on + + + align:start position:0% +and then it's kind of got a shape on +both sides + + align:start position:0% +both sides + + + align:start position:0% +both sides +this picture in the middle are the + + align:start position:0% +this picture in the middle are the + + + align:start position:0% +this picture in the middle are the +samples post demodulation it's actually + + align:start position:0% +samples post demodulation it's actually + + + align:start position:0% +samples post demodulation it's actually +what you received at the receiver after + + align:start position:0% +what you received at the receiver after + + + align:start position:0% +what you received at the receiver after +we ran the demodulation step and the + + align:start position:0% +we ran the demodulation step and the + + + align:start position:0% +we ran the demodulation step and the +stuff on top the blue refers to what was + + align:start position:0% +stuff on top the blue refers to what was + + + align:start position:0% +stuff on top the blue refers to what was +transmitted which in this case was + + align:start position:0% +transmitted which in this case was + + + align:start position:0% +transmitted which in this case was +appealed carrier the green shows what + + align:start position:0% +appealed carrier the green shows what + + + align:start position:0% +appealed carrier the green shows what +was received which was some noisy + + align:start position:0% +was received which was some noisy + + + align:start position:0% +was received which was some noisy +version of the carrier because we didn't + + align:start position:0% +version of the carrier because we didn't + + + align:start position:0% +version of the carrier because we didn't +send information other than just the + + align:start position:0% +send information other than just the + + + align:start position:0% +send information other than just the +carrier this is effectively the first + + align:start position:0% +carrier this is effectively the first + + + align:start position:0% +carrier this is effectively the first +lab we have to do nothing more than + + align:start position:0% +lab we have to do nothing more than + + + align:start position:0% +lab we have to do nothing more than +round us a few times and you know the + + align:start position:0% +round us a few times and you know the + + + align:start position:0% +round us a few times and you know the +essence most of the first task in the + + align:start position:0% +essence most of the first task in the + + + align:start position:0% +essence most of the first task in the +lab first two tasks in the lab is just + + align:start position:0% +lab first two tasks in the lab is just + + + align:start position:0% +lab first two tasks in the lab is just +making sure that the stuff works now + + align:start position:0% +making sure that the stuff works now + + + align:start position:0% +making sure that the stuff works now +this entire system you know everything + + align:start position:0% +this entire system you know everything + + + align:start position:0% +this entire system you know everything +works if this thing called the preamble + + align:start position:0% +works if this thing called the preamble + + + align:start position:0% +works if this thing called the preamble +is decoded so what is this preamble and + + align:start position:0% +is decoded so what is this preamble and + + + align:start position:0% +is decoded so what is this preamble and +why do we need it the problem is that as + + align:start position:0% +why do we need it the problem is that as + + + align:start position:0% +why do we need it the problem is that as +you saw in this graphing receiver when I + + align:start position:0% +you saw in this graphing receiver when I + + + align:start position:0% +you saw in this graphing receiver when I +showed this to you the audio hardware is + + align:start position:0% +showed this to you the audio hardware is + + + align:start position:0% +showed this to you the audio hardware is +going to be a you know what it's doing + + align:start position:0% +going to be a you know what it's doing + + + align:start position:0% +going to be a you know what it's doing +is it's always listening when you run + + align:start position:0% +is it's always listening when you run + + + align:start position:0% +is it's always listening when you run +the program it's always listening on the + + align:start position:0% +the program it's always listening on the + + + align:start position:0% +the program it's always listening on the +channel so it's getting data even when + + align:start position:0% +channel so it's getting data even when + + + align:start position:0% +channel so it's getting data even when +I'm not sending anything it's getting + + align:start position:0% +I'm not sending anything it's getting + + + align:start position:0% +I'm not sending anything it's getting +something there's always something on + + align:start position:0% +something there's always something on + + + align:start position:0% +something there's always something on +the audio channel so the question is how + + align:start position:0% +the audio channel so the question is how + + + align:start position:0% +the audio channel so the question is how +do you know how does this they will know + + align:start position:0% +do you know how does this they will know + + + align:start position:0% +do you know how does this they will know +that what it's receiving as part of the + + align:start position:0% +that what it's receiving as part of the + + + align:start position:0% +that what it's receiving as part of the +legitimate transmission all + + align:start position:0% +legitimate transmission all + + + align:start position:0% +legitimate transmission all +communication systems need to solve this + + align:start position:0% +communication systems need to solve this + + + align:start position:0% +communication systems need to solve this +problem of synchronizing between the + + align:start position:0% +problem of synchronizing between the + + + align:start position:0% +problem of synchronizing between the +sender and receiver and that's done + + align:start position:0% +sender and receiver and that's done + + + align:start position:0% +sender and receiver and that's done +using a preamble the preamble is nothing + + align:start position:0% +using a preamble the preamble is nothing + + + align:start position:0% +using a preamble the preamble is nothing +more than a well known which sequence + + align:start position:0% +more than a well known which sequence + + + align:start position:0% +more than a well known which sequence +sequence of bits that the sender and + + align:start position:0% +sequence of bits that the sender and + + + align:start position:0% +sequence of bits that the sender and +receiver both agree on so in this case + + align:start position:0% +receiver both agree on so in this case + + + align:start position:0% +receiver both agree on so in this case +our preamble is that long sequence there + + align:start position:0% +our preamble is that long sequence there + + + align:start position:0% +our preamble is that long sequence there +1 0 1 1 0 1 1 1 etc and there's some + + align:start position:0% +1 0 1 1 0 1 1 1 etc and there's some + + + align:start position:0% +1 0 1 1 0 1 1 1 etc and there's some +guidelines and rules of thumb that go + + align:start position:0% +guidelines and rules of thumb that go + + + align:start position:0% +guidelines and rules of thumb that go +into how what I'm what makes the + + align:start position:0% +into how what I'm what makes the + + + align:start position:0% +into how what I'm what makes the +preamble good and what makes it not so + + align:start position:0% +preamble good and what makes it not so + + + align:start position:0% +preamble good and what makes it not so +good we're not going to worry about that + + align:start position:0% +good we're not going to worry about that + + + align:start position:0% +good we're not going to worry about that +here I'm just telling you that's the + + align:start position:0% +here I'm just telling you that's the + + + align:start position:0% +here I'm just telling you that's the +preamble so as long as the receiver is + + align:start position:0% +preamble so as long as the receiver is + + + align:start position:0% +preamble so as long as the receiver is +successfully able to decode the preamble + + align:start position:0% +successfully able to decode the preamble + + + align:start position:0% +successfully able to decode the preamble +it means that it knows that there's a + + align:start position:0% +it means that it knows that there's a + + + align:start position:0% +it means that it knows that there's a +legitimate transmission over the air and + + align:start position:0% +legitimate transmission over the air and + + + align:start position:0% +legitimate transmission over the air and +it can start listening to it so if you + + align:start position:0% +it can start listening to it so if you + + + align:start position:0% +it can start listening to it so if you +don't get the preamble we can all bets + + align:start position:0% +don't get the preamble we can all bets + + + align:start position:0% +don't get the preamble we can all bets +are off as to what the heck is going on + + align:start position:0% +are off as to what the heck is going on + + + align:start position:0% +are off as to what the heck is going on +on the channel and sometimes you may not + + align:start position:0% +on the channel and sometimes you may not + + + align:start position:0% +on the channel and sometimes you may not +give the preamble now one of the things + + align:start position:0% +give the preamble now one of the things + + + align:start position:0% +give the preamble now one of the things +you would have to do you would want to + + align:start position:0% +you would have to do you would want to + + + align:start position:0% +you would have to do you would want to +do is when you don't get a preamble + + align:start position:0% + + + + align:start position:0% + +usually it's a sign that the either some + + align:start position:0% +usually it's a sign that the either some + + + align:start position:0% +usually it's a sign that the either some +samples are being lost because the audio + + align:start position:0% +samples are being lost because the audio + + + align:start position:0% +samples are being lost because the audio +hardware isn't able to cope with it and + + align:start position:0% +hardware isn't able to cope with it and + + + align:start position:0% +hardware isn't able to cope with it and +the documentation describes how you deal + + align:start position:0% +the documentation describes how you deal + + + align:start position:0% +the documentation describes how you deal +with that problem or it means that the + + align:start position:0% +with that problem or it means that the + + + align:start position:0% +with that problem or it means that the +sampling rate is too high and maybe + + align:start position:0% +sampling rate is too high and maybe + + + align:start position:0% +sampling rate is too high and maybe +something's running on your computer + + align:start position:0% +something's running on your computer + + + align:start position:0% +something's running on your computer +that's you know I don't know you have + + align:start position:0% +that's you know I don't know you have + + + align:start position:0% +that's you know I don't know you have +some video going on in the background + + align:start position:0% +some video going on in the background + + + align:start position:0% +some video going on in the background +and it's not keeping up to read at forty + + align:start position:0% +and it's not keeping up to read at forty + + + align:start position:0% +and it's not keeping up to read at forty +eight thousand Hertz or at the sign that + + align:start position:0% +eight thousand Hertz or at the sign that + + + align:start position:0% +eight thousand Hertz or at the sign that +the signal-to-noise ratio is too low + + align:start position:0% +the signal-to-noise ratio is too low + + + align:start position:0% +the signal-to-noise ratio is too low +maybe you're in a very crowded location + + align:start position:0% +maybe you're in a very crowded location + + + align:start position:0% +maybe you're in a very crowded location +or maybe the volume is too low so those + + align:start position:0% +or maybe the volume is too low so those + + + align:start position:0% +or maybe the volume is too low so those +are usually the ways in which you go + + align:start position:0% +are usually the ways in which you go + + + align:start position:0% +are usually the ways in which you go +about fixing this problem with the + + align:start position:0% +about fixing this problem with the + + + align:start position:0% +about fixing this problem with the +preamble now I want to show you one more + + align:start position:0% +preamble now I want to show you one more + + + align:start position:0% +preamble now I want to show you one more +noise graph what I'd like you to do now + + align:start position:0% +noise graph what I'd like you to do now + + + align:start position:0% +noise graph what I'd like you to do now +is actually make you know we're going to + + align:start position:0% +is actually make you know we're going to + + + align:start position:0% +is actually make you know we're going to +try to do this with some music on the + + align:start position:0% +try to do this with some music on the + + + align:start position:0% +try to do this with some music on the +side what I want to show you is that as + + align:start position:0% +side what I want to show you is that as + + + align:start position:0% +side what I want to show you is that as +you increase the amount of noise the + + align:start position:0% +you increase the amount of noise the + + + align:start position:0% +you increase the amount of noise the +noise is captured in the variance of the + + align:start position:0% +noise is captured in the variance of the + + + align:start position:0% +noise is captured in the variance of the +Gaussian distribution with more the + + align:start position:0% +Gaussian distribution with more the + + + align:start position:0% +Gaussian distribution with more the +noise the bigger the variance of the + + align:start position:0% +noise the bigger the variance of the + + + align:start position:0% +noise the bigger the variance of the +distribution so I'm going to try to do + + align:start position:0% +distribution so I'm going to try to do + + + align:start position:0% +distribution so I'm going to try to do +this by sending a thousand bits that + + align:start position:0% +this by sending a thousand bits that + + + align:start position:0% +this by sending a thousand bits that +this will take a little bit of time so + + align:start position:0% +this will take a little bit of time so + + + align:start position:0% +this will take a little bit of time so +let's first send it without + + align:start position:0% + + + + align:start position:0% + +so we'll send this without a huge amount + + align:start position:0% +so we'll send this without a huge amount + + + align:start position:0% +so we'll send this without a huge amount +of noise I mean there's some ambient + + align:start position:0% +of noise I mean there's some ambient + + + align:start position:0% +of noise I mean there's some ambient +noise in the room and this will take a + + align:start position:0% +noise in the room and this will take a + + + align:start position:0% +noise in the room and this will take a +little bit of time to demodulate and get + + align:start position:0% +little bit of time to demodulate and get + + + align:start position:0% +little bit of time to demodulate and get +working there's a little couple of + + align:start position:0% +working there's a little couple of + + + align:start position:0% +working there's a little couple of +errors bit error rate was point over to + + align:start position:0% +errors bit error rate was point over to + + + align:start position:0% +errors bit error rate was point over to +two bits were an error here and we saw + + align:start position:0% +two bits were an error here and we saw + + + align:start position:0% +two bits were an error here and we saw +something like this it isn't quite a + + align:start position:0% +something like this it isn't quite a + + + align:start position:0% +something like this it isn't quite a +Gaussian in this case but we saw + + align:start position:0% +Gaussian in this case but we saw + + + align:start position:0% +Gaussian in this case but we saw +something like that now + + align:start position:0% + + + + align:start position:0% + +what I'd like you to do is kind of start + + align:start position:0% +what I'd like you to do is kind of start + + + align:start position:0% +what I'd like you to do is kind of start +when I say yes just start making some + + align:start position:0% +when I say yes just start making some + + + align:start position:0% +when I say yes just start making some +noise just trap or just talk or whatever + + align:start position:0% +noise just trap or just talk or whatever + + + align:start position:0% +noise just trap or just talk or whatever +just you know turn on your phones do + + align:start position:0% +just you know turn on your phones do + + + align:start position:0% +just you know turn on your phones do +something yeah all right all right I was + + align:start position:0% +something yeah all right all right I was + + + align:start position:0% +something yeah all right all right I was +actually going to play I found some nice + + align:start position:0% +actually going to play I found some nice + + + align:start position:0% +actually going to play I found some nice +youtube clips of a music group one of + + align:start position:0% +youtube clips of a music group one of + + + align:start position:0% +youtube clips of a music group one of +the MIT acapella music groups okay we + + align:start position:0% +the MIT acapella music groups okay we + + + align:start position:0% +the MIT acapella music groups okay we +really got toasted here because you guys + + align:start position:0% +really got toasted here because you guys + + + align:start position:0% +really got toasted here because you guys +started talking and we couldn't recover + + align:start position:0% +started talking and we couldn't recover + + + align:start position:0% +started talking and we couldn't recover +the preamble but we probably got that + + align:start position:0% +the preamble but we probably got that + + + align:start position:0% +the preamble but we probably got that +was the noise distribution that we saw + + align:start position:0% +was the noise distribution that we saw + + + align:start position:0% +was the noise distribution that we saw +and you can see that it's actually kind + + align:start position:0% +and you can see that it's actually kind + + + align:start position:0% +and you can see that it's actually kind +of a fat redistribution I'll show you + + align:start position:0% +of a fat redistribution I'll show you + + + align:start position:0% +of a fat redistribution I'll show you +what this picture is this is a picture + + align:start position:0% +what this picture is this is a picture + + + align:start position:0% +what this picture is this is a picture +that essentially you will become your + + align:start position:0% +that essentially you will become your + + + align:start position:0% +that essentially you will become your +best friend or maybe your worst enemy + + align:start position:0% +best friend or maybe your worst enemy + + + align:start position:0% +best friend or maybe your worst enemy +this is called an eye diagram and it + + align:start position:0% +this is called an eye diagram and it + + + align:start position:0% +this is called an eye diagram and it +looks completely messed up so i'm going + + align:start position:0% +looks completely messed up so i'm going + + + align:start position:0% +looks completely messed up so i'm going +to show you what that is and we don't + + align:start position:0% +to show you what that is and we don't + + + align:start position:0% +to show you what that is and we don't +talk about um so let me explain to you + + align:start position:0% +talk about um so let me explain to you + + + align:start position:0% +talk about um so let me explain to you +noise was too high on and the point here + + align:start position:0% +noise was too high on and the point here + + + align:start position:0% +noise was too high on and the point here +is that that's shown in this picture + + align:start position:0% +is that that's shown in this picture + + + align:start position:0% +is that that's shown in this picture +here where we ended up with enough of a + + align:start position:0% +here where we ended up with enough of a + + + align:start position:0% +here where we ended up with enough of a +variation that we couldn't distinguish + + align:start position:0% +variation that we couldn't distinguish + + + align:start position:0% +variation that we couldn't distinguish +between zeros and ones we sent something + + align:start position:0% +between zeros and ones we sent something + + + align:start position:0% +between zeros and ones we sent something +which had a little bit of zeros in the + + align:start position:0% +which had a little bit of zeros in the + + + align:start position:0% +which had a little bit of zeros in the +beginning and then the entire one + + align:start position:0% +beginning and then the entire one + + + align:start position:0% +beginning and then the entire one +distribution was spread between you know + + align:start position:0% +distribution was spread between you know + + + align:start position:0% +distribution was spread between you know +point one volts two point nine volts the + + align:start position:0% +point one volts two point nine volts the + + + align:start position:0% +point one volts two point nine volts the +variance is extremely high now let's do + + align:start position:0% +variance is extremely high now let's do + + + align:start position:0% +variance is extremely high now let's do +one thing i'm going to change this to + + align:start position:0% +one thing i'm going to change this to + + + align:start position:0% +one thing i'm going to change this to +just transmit random pieces of + + align:start position:0% +just transmit random pieces of + + + align:start position:0% +just transmit random pieces of +information here when I don't give + + align:start position:0% +information here when I don't give + + + align:start position:0% +information here when I don't give +anything it means that dama the data + + align:start position:0% +anything it means that dama the data + + + align:start position:0% +anything it means that dama the data +that's being sent is just a random + + align:start position:0% +that's being sent is just a random + + + align:start position:0% +that's being sent is just a random +sequence of zeros and ones let me change + + align:start position:0% +sequence of zeros and ones let me change + + + align:start position:0% +sequence of zeros and ones let me change +this to 200 beds + + align:start position:0% + + + + align:start position:0% + +alright so we got those bits through and + + align:start position:0% + + + + align:start position:0% + +that's a beautiful I diagram I'll + + align:start position:0% +that's a beautiful I diagram I'll + + + align:start position:0% +that's a beautiful I diagram I'll +explain what this means but the point is + + align:start position:0% +explain what this means but the point is + + + align:start position:0% +explain what this means but the point is +that when you see the separation and you + + align:start position:0% +that when you see the separation and you + + + align:start position:0% +that when you see the separation and you +see a point in the middle here with a + + align:start position:0% +see a point in the middle here with a + + + align:start position:0% +see a point in the middle here with a +big gap on this I diagram graph and then + + align:start position:0% +big gap on this I diagram graph and then + + + align:start position:0% +big gap on this I diagram graph and then +you see a separation between these were + + align:start position:0% +you see a separation between these were + + + align:start position:0% +you see a separation between these were +the zeros and those were the ones which + + align:start position:0% +the zeros and those were the ones which + + + align:start position:0% +the zeros and those were the ones which +means you could threshold somewhere in + + align:start position:0% +means you could threshold somewhere in + + + align:start position:0% +means you could threshold somewhere in +the middle and separate out which bits + + align:start position:0% +the middle and separate out which bits + + + align:start position:0% +the middle and separate out which bits +with zeros in which bits were one it + + align:start position:0% +with zeros in which bits were one it + + + align:start position:0% +with zeros in which bits were one it +means you're cooking things are great + + align:start position:0% +means you're cooking things are great + + + align:start position:0% +means you're cooking things are great +okay so you can see that there's some + + align:start position:0% +okay so you can see that there's some + + + align:start position:0% +okay so you can see that there's some +distribution here of what the ones look + + align:start position:0% +distribution here of what the ones look + + + align:start position:0% +distribution here of what the ones look +like in the empirical data there's a + + align:start position:0% +like in the empirical data there's a + + + align:start position:0% +like in the empirical data there's a +distribution hear what the zeros are + + align:start position:0% +distribution hear what the zeros are + + + align:start position:0% +distribution hear what the zeros are +look like this is not going to be a + + align:start position:0% +look like this is not going to be a + + + align:start position:0% +look like this is not going to be a +Gaussian at all I'll explain why that is + + align:start position:0% +Gaussian at all I'll explain why that is + + + align:start position:0% +Gaussian at all I'll explain why that is +in a moment okay so I have to do two + + align:start position:0% +in a moment okay so I have to do two + + + align:start position:0% +in a moment okay so I have to do two +more things today and then I'll turn it + + align:start position:0% +more things today and then I'll turn it + + + align:start position:0% +more things today and then I'll turn it +over to Professor for gays the first one + + align:start position:0% +over to Professor for gays the first one + + + align:start position:0% +over to Professor for gays the first one +I want to explain to you is what this + + align:start position:0% +I want to explain to you is what this + + + align:start position:0% +I want to explain to you is what this +eye diagram is and why it's kind of + + align:start position:0% +eye diagram is and why it's kind of + + + align:start position:0% +eye diagram is and why it's kind of +useful and why as you add more noise + + align:start position:0% +useful and why as you add more noise + + + align:start position:0% +useful and why as you add more noise +into the system the combination of + + align:start position:0% +into the system the combination of + + + align:start position:0% +into the system the combination of +something called inter symbol + + align:start position:0% +something called inter symbol + + + align:start position:0% +something called inter symbol +interference and noise getting way + + align:start position:0% +interference and noise getting way + + + align:start position:0% +interference and noise getting way +recording the base now on this channel + + align:start position:0% +recording the base now on this channel + + + align:start position:0% +recording the base now on this channel +there are two things that distort the + + align:start position:0% +there are two things that distort the + + + align:start position:0% +there are two things that distort the +quality of communication the first is + + align:start position:0% +quality of communication the first is + + + align:start position:0% +quality of communication the first is +novice and you kind of saw the effect of + + align:start position:0% +novice and you kind of saw the effect of + + + align:start position:0% +novice and you kind of saw the effect of +that the second is this thing that we've + + align:start position:0% +that the second is this thing that we've + + + align:start position:0% +that the second is this thing that we've +been studying with by modeling it as a + + align:start position:0% +been studying with by modeling it as a + + + align:start position:0% +been studying with by modeling it as a +linear time-invariant system the idea is + + align:start position:0% +linear time-invariant system the idea is + + + align:start position:0% +linear time-invariant system the idea is +that when you have a sequence of zeros + + align:start position:0% +that when you have a sequence of zeros + + + align:start position:0% +that when you have a sequence of zeros +on the input and then you go into a + + align:start position:0% +on the input and then you go into a + + + align:start position:0% +on the input and then you go into a +sequence of one samples that sudden + + align:start position:0% +sequence of one samples that sudden + + + align:start position:0% +sequence of one samples that sudden +sharp input transition does not + + align:start position:0% +sharp input transition does not + + + align:start position:0% +sharp input transition does not +immediately get captured the receiver it + + align:start position:0% +immediately get captured the receiver it + + + align:start position:0% +immediately get captured the receiver it +takes time for the zero to settle into a + + align:start position:0% +takes time for the zero to settle into a + + + align:start position:0% +takes time for the zero to settle into a +one and one to settle in 20 and you can + + align:start position:0% +one and one to settle in 20 and you can + + + align:start position:0% +one and one to settle in 20 and you can +see that in this picture here now let's + + align:start position:0% +see that in this picture here now let's + + + align:start position:0% +see that in this picture here now let's +focus in in this picture here and look + + align:start position:0% +focus in in this picture here and look + + + align:start position:0% +focus in in this picture here and look +carefully at this place here + + align:start position:0% + + + + align:start position:0% + +oops + + align:start position:0% + + + + align:start position:0% + +all right let's do this again I learned + + align:start position:0% +all right let's do this again I learned + + + align:start position:0% +all right let's do this again I learned +about this like 15 minutes ago so bear + + align:start position:0% +about this like 15 minutes ago so bear + + + align:start position:0% +about this like 15 minutes ago so bear +with me + + align:start position:0% + + + + align:start position:0% + +alright so there was zeros at the bottom + + align:start position:0% +alright so there was zeros at the bottom + + + align:start position:0% +alright so there was zeros at the bottom +and then we bumped up to a one on the + + align:start position:0% +and then we bumped up to a one on the + + + align:start position:0% +and then we bumped up to a one on the +input the input bumped from a zero to a + + align:start position:0% +input the input bumped from a zero to a + + + align:start position:0% +input the input bumped from a zero to a +one this is after we'd be modulated so + + align:start position:0% +one this is after we'd be modulated so + + + align:start position:0% +one this is after we'd be modulated so +if things work perfectly you would see + + align:start position:0% +if things work perfectly you would see + + + align:start position:0% +if things work perfectly you would see +at the output the zero immediately goes + + align:start position:0% +at the output the zero immediately goes + + + align:start position:0% +at the output the zero immediately goes +to one but what do you actually see you + + align:start position:0% +to one but what do you actually see you + + + align:start position:0% +to one but what do you actually see you +see that it takes a while for the one to + + align:start position:0% +see that it takes a while for the one to + + + align:start position:0% +see that it takes a while for the one to +settle down right it goes from a zero to + + align:start position:0% +settle down right it goes from a zero to + + + align:start position:0% +settle down right it goes from a zero to +one sharply on the input but it takes a + + align:start position:0% +one sharply on the input but it takes a + + + align:start position:0% +one sharply on the input but it takes a +while to go from 0 to 1 and then I go up + + align:start position:0% +while to go from 0 to 1 and then I go up + + + align:start position:0% +while to go from 0 to 1 and then I go up +like that and then I want to go from one + + align:start position:0% +like that and then I want to go from one + + + align:start position:0% +like that and then I want to go from one +to zero and you can see that as it comes + + align:start position:0% +to zero and you can see that as it comes + + + align:start position:0% +to zero and you can see that as it comes +down to zero it takes a while to settle + + align:start position:0% +down to zero it takes a while to settle + + + align:start position:0% +down to zero it takes a while to settle +down do you guys all understand why that + + align:start position:0% +down do you guys all understand why that + + + align:start position:0% +down do you guys all understand why that +happens I don't mean the physics of why + + align:start position:0% +happens I don't mean the physics of why + + + align:start position:0% +happens I don't mean the physics of why +it happens but what I mean is how that + + align:start position:0% +it happens but what I mean is how that + + + align:start position:0% +it happens but what I mean is how that +idea relates to this idea of the unit + + align:start position:0% +idea relates to this idea of the unit + + + align:start position:0% +idea relates to this idea of the unit +step response from the unit sample + + align:start position:0% +step response from the unit sample + + + align:start position:0% +step response from the unit sample +response this is nothing more than the + + align:start position:0% +response this is nothing more than the + + + align:start position:0% +response this is nothing more than the +unit step response of this channel right + + align:start position:0% +unit step response of this channel right + + + align:start position:0% +unit step response of this channel right +I have a zero and I've assumed among 0 + + align:start position:0% +I have a zero and I've assumed among 0 + + + align:start position:0% +I have a zero and I've assumed among 0 +for a while I bump up to a one and it + + align:start position:0% +for a while I bump up to a one and it + + + align:start position:0% +for a while I bump up to a one and it +takes a while for it to go from 0 to 1 + + align:start position:0% +takes a while for it to go from 0 to 1 + + + align:start position:0% +takes a while for it to go from 0 to 1 +and similarly takes a while for it to go + + align:start position:0% +and similarly takes a while for it to go + + + align:start position:0% +and similarly takes a while for it to go +from one back to zero now suppose I end + + align:start position:0% +from one back to zero now suppose I end + + + align:start position:0% +from one back to zero now suppose I end +up switching 0 1 1 0 0 1 0 1 0 1 very + + align:start position:0% +up switching 0 1 1 0 0 1 0 1 0 1 very + + + align:start position:0% +up switching 0 1 1 0 0 1 0 1 0 1 very +very quickly and I don't give enough + + align:start position:0% +very quickly and I don't give enough + + + align:start position:0% +very quickly and I don't give enough +time for the whole thing to settle down + + align:start position:0% +time for the whole thing to settle down + + + align:start position:0% +time for the whole thing to settle down +in other words as I go from a zero to + + align:start position:0% +in other words as I go from a zero to + + + align:start position:0% +in other words as I go from a zero to +LaVon + + align:start position:0% + + + + align:start position:0% + +before it settles down into one if the + + align:start position:0% +before it settles down into one if the + + + align:start position:0% +before it settles down into one if the +next bit is a zero and then I start + + align:start position:0% +next bit is a zero and then I start + + + align:start position:0% +next bit is a zero and then I start +coming down and before it the next bit + + align:start position:0% +coming down and before it the next bit + + + align:start position:0% +coming down and before it the next bit +settles down to 0 I get to a 1 and + + align:start position:0% +settles down to 0 I get to a 1 and + + + align:start position:0% +settles down to 0 I get to a 1 and +before it comes back to zero you know I + + align:start position:0% +before it comes back to zero you know I + + + align:start position:0% +before it comes back to zero you know I +keep doing that what I'm going to end up + + align:start position:0% +keep doing that what I'm going to end up + + + align:start position:0% +keep doing that what I'm going to end up +with is this combination of zeros and + + align:start position:0% +with is this combination of zeros and + + + align:start position:0% +with is this combination of zeros and +ones that are sort of random start + + align:start position:0% +ones that are sort of random start + + + align:start position:0% +ones that are sort of random start +confusing the receiver because we're not + + align:start position:0% +confusing the receiver because we're not + + + align:start position:0% +confusing the receiver because we're not +giving enough time for the zero to + + align:start position:0% +giving enough time for the zero to + + + align:start position:0% +giving enough time for the zero to +settle down and similarly when we go + + align:start position:0% +settle down and similarly when we go + + + align:start position:0% +settle down and similarly when we go +from a zero to one we're not giving + + align:start position:0% +from a zero to one we're not giving + + + align:start position:0% +from a zero to one we're not giving +enough time for the one to settle down + + align:start position:0% +enough time for the one to settle down + + + align:start position:0% +enough time for the one to settle down +that's what this I diagram was referring + + align:start position:0% +that's what this I diagram was referring + + + align:start position:0% +that's what this I diagram was referring +to where we found in this confused case + + align:start position:0% +to where we found in this confused case + + + align:start position:0% +to where we found in this confused case +and then when you have noise some of the + + align:start position:0% +and then when you have noise some of the + + + align:start position:0% +and then when you have noise some of the +zeros get moved to one anyway and ones + + align:start position:0% +zeros get moved to one anyway and ones + + + align:start position:0% +zeros get moved to one anyway and ones +get moved to zero and we end up with + + align:start position:0% +get moved to zero and we end up with + + + align:start position:0% +get moved to zero and we end up with +this very crowded picture the way you + + align:start position:0% +this very crowded picture the way you + + + align:start position:0% +this very crowded picture the way you +tackle this problem is it all has to do + + align:start position:0% +tackle this problem is it all has to do + + + align:start position:0% +tackle this problem is it all has to do +with the number of samples that you + + align:start position:0% +with the number of samples that you + + + align:start position:0% +with the number of samples that you +decide to use within one pit so coming + + align:start position:0% +decide to use within one pit so coming + + + align:start position:0% +decide to use within one pit so coming +back to this picture if I do this at + + align:start position:0% +back to this picture if I do this at + + + align:start position:0% +back to this picture if I do this at +forty eight thousand samples per second + + align:start position:0% +forty eight thousand samples per second + + + align:start position:0% +forty eight thousand samples per second +in any one of these carriers I have 48 + + align:start position:0% +in any one of these carriers I have 48 + + + align:start position:0% +in any one of these carriers I have 48 +samples that I use but now I get to + + align:start position:0% +samples that I use but now I get to + + + align:start position:0% +samples that I use but now I get to +decide how many samples corresponds to + + align:start position:0% +decide how many samples corresponds to + + + align:start position:0% +decide how many samples corresponds to +one bit of information when I have a bit + + align:start position:0% +one bit of information when I have a bit + + + align:start position:0% +one bit of information when I have a bit +that I want to transmit let's say a 1 + + align:start position:0% + + + + align:start position:0% + +how many arm sounds + + align:start position:0% + + + + align:start position:0% + +what that effectively means is to + + align:start position:0% +what that effectively means is to + + + align:start position:0% +what that effectively means is to +transmit a one how many of these periods + + align:start position:0% +transmit a one how many of these periods + + + align:start position:0% +transmit a one how many of these periods +of this waveform do I want to use to + + align:start position:0% +of this waveform do I want to use to + + + align:start position:0% +of this waveform do I want to use to +transmit a one so for example if I pick + + align:start position:0% +transmit a one so for example if I pick + + + align:start position:0% +transmit a one so for example if I pick +um if I decide I want to send a one as + + align:start position:0% +um if I decide I want to send a one as + + + align:start position:0% +um if I decide I want to send a one as +three carriers of the waveform then in + + align:start position:0% +three carriers of the waveform then in + + + align:start position:0% +three carriers of the waveform then in +any one of these carriers I have 48 + + align:start position:0% +any one of these carriers I have 48 + + + align:start position:0% +any one of these carriers I have 48 +samples therefore I represent a one as + + align:start position:0% +samples therefore I represent a one as + + + align:start position:0% +samples therefore I represent a one as +48 x 3 which is 144 samples probate + + align:start position:0% + + + + align:start position:0% + +now to transmit a zero I could do a + + align:start position:0% +now to transmit a zero I could do a + + + align:start position:0% +now to transmit a zero I could do a +bunch of different things I could decide + + align:start position:0% +bunch of different things I could decide + + + align:start position:0% +bunch of different things I could decide +to keep the channel silent if I do that + + align:start position:0% +to keep the channel silent if I do that + + + align:start position:0% +to keep the channel silent if I do that +it's about on-off keying and that's what + + align:start position:0% +it's about on-off keying and that's what + + + align:start position:0% +it's about on-off keying and that's what +we're using here so we're sending one as + + align:start position:0% +we're using here so we're sending one as + + + align:start position:0% +we're using here so we're sending one as +if we decide to use 144 samples per bit + + align:start position:0% +if we decide to use 144 samples per bit + + + align:start position:0% +if we decide to use 144 samples per bit +then it means we represent a one as 144 + + align:start position:0% +then it means we represent a one as 144 + + + align:start position:0% +then it means we represent a one as 144 +samples which corresponds to three of + + align:start position:0% +samples which corresponds to three of + + + align:start position:0% +samples which corresponds to three of +these and then we represent a zero as + + align:start position:0% +these and then we represent a zero as + + + align:start position:0% +these and then we represent a zero as +nothing so we don't say anything if we + + align:start position:0% +nothing so we don't say anything if we + + + align:start position:0% +nothing so we don't say anything if we +do that this is called on-off keying + + align:start position:0% +do that this is called on-off keying + + + align:start position:0% +do that this is called on-off keying +because we send on for one where we send + + align:start position:0% +because we send on for one where we send + + + align:start position:0% +because we send on for one where we send +a sinusoid and for sending a zero bit we + + align:start position:0% +a sinusoid and for sending a zero bit we + + + align:start position:0% +a sinusoid and for sending a zero bit we +send nothing now if the number of + + align:start position:0% +send nothing now if the number of + + + align:start position:0% +send nothing now if the number of +samples i select / bit is too small you + + align:start position:0% +samples i select / bit is too small you + + + align:start position:0% +samples i select / bit is too small you +end up with this effect that I don't + + align:start position:0% +end up with this effect that I don't + + + align:start position:0% +end up with this effect that I don't +give enough time for the 0 to settle + + align:start position:0% +give enough time for the 0 to settle + + + align:start position:0% +give enough time for the 0 to settle +down to better when I make the + + align:start position:0% +down to better when I make the + + + align:start position:0% +down to better when I make the +transition from a 0 to a 1 if I pick two + + align:start position:0% +transition from a 0 to a 1 if I pick two + + + align:start position:0% +transition from a 0 to a 1 if I pick two +small samples per bit before we settle + + align:start position:0% +small samples per bit before we settle + + + align:start position:0% +small samples per bit before we settle +into a 1 the next bit may show up as a 0 + + align:start position:0% +into a 1 the next bit may show up as a 0 + + + align:start position:0% +into a 1 the next bit may show up as a 0 +and then before we settle down in 20 the + + align:start position:0% +and then before we settle down in 20 the + + + align:start position:0% +and then before we settle down in 20 the +next bit shows up perhaps as a 1 and we + + align:start position:0% +next bit shows up perhaps as a 1 and we + + + align:start position:0% +next bit shows up perhaps as a 1 and we +end up coming lling the zeros and the + + align:start position:0% +end up coming lling the zeros and the + + + align:start position:0% +end up coming lling the zeros and the +ones and we're not able at the receiver + + align:start position:0% +ones and we're not able at the receiver + + + align:start position:0% +ones and we're not able at the receiver +to tell the difference between these + + align:start position:0% +to tell the difference between these + + + align:start position:0% +to tell the difference between these +different voltage samples after we + + align:start position:0% +different voltage samples after we + + + align:start position:0% +different voltage samples after we +demodulate so we don't know what + + align:start position:0% +demodulate so we don't know what + + + align:start position:0% +demodulate so we don't know what +happened so if the eye diagram is a way + + align:start position:0% +happened so if the eye diagram is a way + + + align:start position:0% +happened so if the eye diagram is a way +to capture that what the eye diagram + + align:start position:0% +to capture that what the eye diagram + + + align:start position:0% +to capture that what the eye diagram +does is it's a kind of a clever hack + + align:start position:0% +does is it's a kind of a clever hack + + + align:start position:0% +does is it's a kind of a clever hack +what it does is thought I had it + + align:start position:0% +what it does is thought I had it + + + align:start position:0% +what it does is thought I had it +somewhere else + + align:start position:0% + + + + align:start position:0% + +the way you generate an eye diagram you + + align:start position:0% +the way you generate an eye diagram you + + + align:start position:0% +the way you generate an eye diagram you +don't have to worry about the writing + + align:start position:0% +don't have to worry about the writing + + + align:start position:0% +don't have to worry about the writing +the software for it but you will look at + + align:start position:0% +the software for it but you will look at + + + align:start position:0% +the software for it but you will look at +a lot of these kinds of pictures in lab + + align:start position:0% +a lot of these kinds of pictures in lab + + + align:start position:0% +a lot of these kinds of pictures in lab +5 you transmit a random sequence of bits + + align:start position:0% +5 you transmit a random sequence of bits + + + align:start position:0% +5 you transmit a random sequence of bits +and then you look at the samples that + + align:start position:0% +and then you look at the samples that + + + align:start position:0% +and then you look at the samples that +were received at the receiver after the + + align:start position:0% +were received at the receiver after the + + + align:start position:0% +were received at the receiver after the +demodulation was done those the output + + align:start position:0% +demodulation was done those the output + + + align:start position:0% +demodulation was done those the output +of the demodulation is a set of voltage + + align:start position:0% +of the demodulation is a set of voltage + + + align:start position:0% +of the demodulation is a set of voltage +values what you do is you look at three + + align:start position:0% +values what you do is you look at three + + + align:start position:0% +values what you do is you look at three +bit periods in other words you look at a + + align:start position:0% +bit periods in other words you look at a + + + align:start position:0% +bit periods in other words you look at a +sequence of time a number of samples + + align:start position:0% +sequence of time a number of samples + + + align:start position:0% +sequence of time a number of samples +that corresponds to three big period so + + align:start position:0% +that corresponds to three big period so + + + align:start position:0% +that corresponds to three big period so +for example if i pick 144 samples per + + align:start position:0% +for example if i pick 144 samples per + + + align:start position:0% +for example if i pick 144 samples per +big what I do is I take 144 and multiply + + align:start position:0% +big what I do is I take 144 and multiply + + + align:start position:0% +big what I do is I take 144 and multiply +that by three a bit periods and I look + + align:start position:0% +that by three a bit periods and I look + + + align:start position:0% +that by three a bit periods and I look +at that many samples so for every three + + align:start position:0% +at that many samples so for every three + + + align:start position:0% +at that many samples so for every three +big periods I take all the samples and I + + align:start position:0% +big periods I take all the samples and I + + + align:start position:0% +big periods I take all the samples and I +plot them okay so a particular sequence + + align:start position:0% +plot them okay so a particular sequence + + + align:start position:0% +plot them okay so a particular sequence +of bits in this case it might be a0 and + + align:start position:0% +of bits in this case it might be a0 and + + + align:start position:0% +of bits in this case it might be a0 and +a1 and a0 this is a zero followed by a + + align:start position:0% +a1 and a0 this is a zero followed by a + + + align:start position:0% +a1 and a0 this is a zero followed by a +one followed by zero a different + + align:start position:0% +one followed by zero a different + + + align:start position:0% +one followed by zero a different +sequence of bits could be a one followed + + align:start position:0% +sequence of bits could be a one followed + + + align:start position:0% +sequence of bits could be a one followed +by one followed by one a different + + align:start position:0% +by one followed by one a different + + + align:start position:0% +by one followed by one a different +sequence of bits could be a zero + + align:start position:0% +sequence of bits could be a zero + + + align:start position:0% +sequence of bits could be a zero +followed by zero followed by zero so + + align:start position:0% +followed by zero followed by zero so + + + align:start position:0% +followed by zero followed by zero so +there are you know eight combinations of + + align:start position:0% +there are you know eight combinations of + + + align:start position:0% +there are you know eight combinations of +sequences of three bits each so there + + align:start position:0% +sequences of three bits each so there + + + align:start position:0% +sequences of three bits each so there +are eight you know you have a clean + + align:start position:0% +are eight you know you have a clean + + + align:start position:0% +are eight you know you have a clean +system clean I diagram like this you're + + align:start position:0% +system clean I diagram like this you're + + + align:start position:0% +system clean I diagram like this you're +going to see a variety of different + + align:start position:0% +going to see a variety of different + + + align:start position:0% +going to see a variety of different +lines corresponding to all the places + + align:start position:0% +lines corresponding to all the places + + + align:start position:0% +lines corresponding to all the places +where different three bit sequences + + align:start position:0% +where different three bit sequences + + + align:start position:0% +where different three bit sequences +appeared in your input so for any given + + align:start position:0% +appeared in your input so for any given + + + align:start position:0% +appeared in your input so for any given +3-bit sequence at the input there's a + + align:start position:0% +3-bit sequence at the input there's a + + + align:start position:0% +3-bit sequence at the input there's a +3-bit sample sequence at the output that + + align:start position:0% +3-bit sample sequence at the output that + + + align:start position:0% +3-bit sample sequence at the output that +corresponds to a number of samples equal + + align:start position:0% +corresponds to a number of samples equal + + + align:start position:0% +corresponds to a number of samples equal +to the samples per bit x three + + align:start position:0% +to the samples per bit x three + + + align:start position:0% +to the samples per bit x three +and each of those generates one of those + + align:start position:0% +and each of those generates one of those + + + align:start position:0% +and each of those generates one of those +trajectories through this picture if you + + align:start position:0% +trajectories through this picture if you + + + align:start position:0% +trajectories through this picture if you +generate that picture and you find that + + align:start position:0% +generate that picture and you find that + + + align:start position:0% +generate that picture and you find that +there's a very clean gap between all + + align:start position:0% +there's a very clean gap between all + + + align:start position:0% +there's a very clean gap between all +possible combinations of these bit + + align:start position:0% +possible combinations of these bit + + + align:start position:0% +possible combinations of these bit +sequences as is in this case here then + + align:start position:0% +sequences as is in this case here then + + + align:start position:0% +sequences as is in this case here then +it means that you've been able to decode + + align:start position:0% +it means that you've been able to decode + + + align:start position:0% +it means that you've been able to decode +you're very likely to be able to decode + + align:start position:0% +you're very likely to be able to decode + + + align:start position:0% +you're very likely to be able to decode +because what you can do is essentially + + align:start position:0% +because what you can do is essentially + + + align:start position:0% +because what you can do is essentially +the receiver can decide that you know + + align:start position:0% +the receiver can decide that you know + + + align:start position:0% +the receiver can decide that you know +when one's happen it corresponds to + + align:start position:0% +when one's happen it corresponds to + + + align:start position:0% +when one's happen it corresponds to +something over here at point three five + + align:start position:0% +something over here at point three five + + + align:start position:0% +something over here at point three five +or point 4 volts when a zero happens it + + align:start position:0% +or point 4 volts when a zero happens it + + + align:start position:0% +or point 4 volts when a zero happens it +may not be a zero but it'd make a + + align:start position:0% +may not be a zero but it'd make a + + + align:start position:0% +may not be a zero but it'd make a +respond to something like a point 1 volt + + align:start position:0% +respond to something like a point 1 volt + + + align:start position:0% +respond to something like a point 1 volt +here which means i can pick the middle + + align:start position:0% +here which means i can pick the middle + + + align:start position:0% +here which means i can pick the middle +point and slice it at that middle point + + align:start position:0% +point and slice it at that middle point + + + align:start position:0% +point and slice it at that middle point +to determine whether the receive bits + + align:start position:0% +to determine whether the receive bits + + + align:start position:0% +to determine whether the receive bits +were a 0 or a 1 now if we would run this + + align:start position:0% +were a 0 or a 1 now if we would run this + + + align:start position:0% +were a 0 or a 1 now if we would run this +experiment again and make a lot of noise + + align:start position:0% +experiment again and make a lot of noise + + + align:start position:0% +experiment again and make a lot of noise +let's try that what could happen is we + + align:start position:0% +let's try that what could happen is we + + + align:start position:0% +let's try that what could happen is we +may not be able to decode at all so I'm + + align:start position:0% +may not be able to decode at all so I'm + + + align:start position:0% +may not be able to decode at all so I'm +going to request you guys to make a + + align:start position:0% +going to request you guys to make a + + + align:start position:0% +going to request you guys to make a +little bit of noise so after I start and + + align:start position:0% +little bit of noise so after I start and + + + align:start position:0% +little bit of noise so after I start and +then we'll see how it goes alright start + + align:start position:0% + + + + align:start position:0% + +you know what it wasn't loud enough it + + align:start position:0% +you know what it wasn't loud enough it + + + align:start position:0% +you know what it wasn't loud enough it +work great but let's look at what the + + align:start position:0% +work great but let's look at what the + + + align:start position:0% +work great but let's look at what the +eye diagram looks like well that's a + + align:start position:0% +eye diagram looks like well that's a + + + align:start position:0% +eye diagram looks like well that's a +little worse than the other one but i + + align:start position:0% +little worse than the other one but i + + + align:start position:0% +little worse than the other one but i +think the energy is down in this room so + + align:start position:0% +think the energy is down in this room so + + + align:start position:0% +think the energy is down in this room so +let's do it one more time oh I want to + + align:start position:0% +let's do it one more time oh I want to + + + align:start position:0% +let's do it one more time oh I want to +be in a position where nothing decodes + + align:start position:0% + + + + align:start position:0% + +well fifteen percent bit errors in fact + + align:start position:0% +well fifteen percent bit errors in fact + + + align:start position:0% +well fifteen percent bit errors in fact +my preamble decoded which is amazing + + align:start position:0% + + + + align:start position:0% + +that's what it looked like ok this is a + + align:start position:0% +that's what it looked like ok this is a + + + align:start position:0% +that's what it looked like ok this is a +an eye diagram even a mother wouldn't + + align:start position:0% +an eye diagram even a mother wouldn't + + + align:start position:0% +an eye diagram even a mother wouldn't +like all right so I'm going to stop here + + align:start position:0% +like all right so I'm going to stop here + + + align:start position:0% +like all right so I'm going to stop here +before I turn it over to Professor with + + align:start position:0% +before I turn it over to Professor with + + + align:start position:0% +before I turn it over to Professor with +these are there any questions anything + + align:start position:0% +these are there any questions anything + + + align:start position:0% +these are there any questions anything +at all I know some of you have had + + align:start position:0% +at all I know some of you have had + + + align:start position:0% +at all I know some of you have had +issues and I met want to talk you this + + align:start position:0% +issues and I met want to talk you this + + + align:start position:0% +issues and I met want to talk you this +morning to fix your computers and I'm + + align:start position:0% +morning to fix your computers and I'm + + + align:start position:0% +morning to fix your computers and I'm +happy to do that I'll be in the lab from + + align:start position:0% +happy to do that I'll be in the lab from + + + align:start position:0% +happy to do that I'll be in the lab from +four o'clock we'll get it working on + + align:start position:0% +four o'clock we'll get it working on + + + align:start position:0% +four o'clock we'll get it working on +your computer's if it doesn't work then + + align:start position:0% +your computer's if it doesn't work then + + + align:start position:0% +your computer's if it doesn't work then +you're going to have to use the lab + + align:start position:0% +you're going to have to use the lab + + + align:start position:0% +you're going to have to use the lab +machines let's take some questions or + + align:start position:0% +machines let's take some questions or + + + align:start position:0% +machines let's take some questions or +comments any if people have any + + align:start position:0% +comments any if people have any + + + align:start position:0% +comments any if people have any +questions about this stuff so people get + + align:start position:0% +questions about this stuff so people get + + + align:start position:0% +questions about this stuff so people get +an idea of what's going on and what you + + align:start position:0% +an idea of what's going on and what you + + + align:start position:0% +an idea of what's going on and what you +need to do once you get this working the + + align:start position:0% +need to do once you get this working the + + + align:start position:0% +need to do once you get this working the +labs sort of you know they'll write + + align:start position:0% +labs sort of you know they'll write + + + align:start position:0% +labs sort of you know they'll write +themselves you just have to a little bit + + align:start position:0% +themselves you just have to a little bit + + + align:start position:0% +themselves you just have to a little bit +of work + + align:start position:0% +of work + + + align:start position:0% +of work +questions this can go up to higher + + align:start position:0% +questions this can go up to higher + + + align:start position:0% +questions this can go up to higher +frequencies to so the sounds annoying + + align:start position:0% +frequencies to so the sounds annoying + + + align:start position:0% +frequencies to so the sounds annoying +your ears you can actually get it to + + align:start position:0% +your ears you can actually get it to + + + align:start position:0% +your ears you can actually get it to +work I know one of you guys is trying to + + align:start position:0% +work I know one of you guys is trying to + + + align:start position:0% +work I know one of you guys is trying to +get this to work with ultrasonic + + align:start position:0% +get this to work with ultrasonic + + + align:start position:0% +get this to work with ultrasonic +reception that's challenging but we can + + align:start position:0% +reception that's challenging but we can + + + align:start position:0% +reception that's challenging but we can +probably help you off yeah + + align:start position:0% + + + + align:start position:0% + +uniform noise + + align:start position:0% + + + + align:start position:0% + +yeah you mean if you were to make + + align:start position:0% +yeah you mean if you were to make + + + align:start position:0% +yeah you mean if you were to make +another transmission are exactly the + + align:start position:0% +another transmission are exactly the + + + align:start position:0% +another transmission are exactly the +same frequency the beauty of this is + + align:start position:0% +same frequency the beauty of this is + + + align:start position:0% +same frequency the beauty of this is +that there's there's different + + align:start position:0% +that there's there's different + + + align:start position:0% +that there's there's different +demodulation schemes right now we're + + align:start position:0% +demodulation schemes right now we're + + + align:start position:0% +demodulation schemes right now we're +using something called the envelope + + align:start position:0% +using something called the envelope + + + align:start position:0% +using something called the envelope +demodulation which are several gives + + align:start position:0% +demodulation which are several gives + + + align:start position:0% +demodulation which are several gives +talked about before all that's doing is + + align:start position:0% +talked about before all that's doing is + + + align:start position:0% +talked about before all that's doing is +it's taking the absolute value of every + + align:start position:0% +it's taking the absolute value of every + + + align:start position:0% +it's taking the absolute value of every +received sample and then running a + + align:start position:0% +received sample and then running a + + + align:start position:0% +received sample and then running a +simple averaging filter and that's what + + align:start position:0% +simple averaging filter and that's what + + + align:start position:0% +simple averaging filter and that's what +you write in the lab it's a very very + + align:start position:0% +you write in the lab it's a very very + + + align:start position:0% +you write in the lab it's a very very +simple demodulation will study something + + align:start position:0% +simple demodulation will study something + + + align:start position:0% +simple demodulation will study something +called quadrature demodulation in a + + align:start position:0% +called quadrature demodulation in a + + + align:start position:0% +called quadrature demodulation in a +probably next lecture or the one after + + align:start position:0% +probably next lecture or the one after + + + align:start position:0% +probably next lecture or the one after +that which means that we'll have the + + align:start position:0% +that which means that we'll have the + + + align:start position:0% +that which means that we'll have the +property that if you transmit at a + + align:start position:0% +property that if you transmit at a + + + align:start position:0% +property that if you transmit at a +certain frequency and somebody else + + align:start position:0% +certain frequency and somebody else + + + align:start position:0% +certain frequency and somebody else +interferes and transmits at a different + + align:start position:0% +interferes and transmits at a different + + + align:start position:0% +interferes and transmits at a different +carrier frequency you're still going to + + align:start position:0% +carrier frequency you're still going to + + + align:start position:0% +carrier frequency you're still going to +be able to recover your transmission but + + align:start position:0% +be able to recover your transmission but + + + align:start position:0% +be able to recover your transmission but +if it if the other transmitter has + + align:start position:0% +if it if the other transmitter has + + + align:start position:0% +if it if the other transmitter has +significant strength signal strength in + + align:start position:0% +significant strength signal strength in + + + align:start position:0% +significant strength signal strength in +the same frequencies that you're + + align:start position:0% +the same frequencies that you're + + + align:start position:0% +the same frequencies that you're +transmitting in then he's going to start + + align:start position:0% +transmitting in then he's going to start + + + align:start position:0% +transmitting in then he's going to start +to look like noise to you and that's + + align:start position:0% +to look like noise to you and that's + + + align:start position:0% +to look like noise to you and that's +going to not work so what happened here + + align:start position:0% +going to not work so what happened here + + + align:start position:0% +going to not work so what happened here +is when you guys were all whistling and + + align:start position:0% +is when you guys were all whistling and + + + align:start position:0% +is when you guys were all whistling and +were clapping and so on you know there + + align:start position:0% +were clapping and so on you know there + + + align:start position:0% +were clapping and so on you know there +was there were signal generated across + + align:start position:0% +was there were signal generated across + + + align:start position:0% +was there were signal generated across +all frequencies including the frequency + + align:start position:0% +all frequencies including the frequency + + + align:start position:0% +all frequencies including the frequency +at which I was transmitting and that's + + align:start position:0% +at which I was transmitting and that's + + + align:start position:0% +at which I was transmitting and that's +what caused the signal to have noise + + align:start position:0% +what caused the signal to have noise + + + align:start position:0% +what caused the signal to have noise +it's not like you know you were all + + align:start position:0% +it's not like you know you were all + + + align:start position:0% +it's not like you know you were all +transmitting at a thousand Hertz it just + + align:start position:0% +transmitting at a thousand Hertz it just + + + align:start position:0% +transmitting at a thousand Hertz it just +so happens that you know that + + align:start position:0% +so happens that you know that + + + align:start position:0% +so happens that you know that +combination of noise you were making had + + align:start position:0% +combination of noise you were making had + + + align:start position:0% +combination of noise you were making had +a component a thousand Hertz that answer + + align:start position:0% +a component a thousand Hertz that answer + + + align:start position:0% +a component a thousand Hertz that answer +your question + + align:start position:0% + + + + align:start position:0% + +any other questions comments or marks + + align:start position:0% + + + + align:start position:0% + +okay yeah we've been talking about + + align:start position:0% +okay yeah we've been talking about + + + align:start position:0% +okay yeah we've been talking about +modeling the baseband channel and we've + + align:start position:0% +modeling the baseband channel and we've + + + align:start position:0% +modeling the baseband channel and we've +said we'll focus on LTI channels so I + + align:start position:0% +said we'll focus on LTI channels so I + + + align:start position:0% +said we'll focus on LTI channels so I +just wanted to take advantage of this + + align:start position:0% +just wanted to take advantage of this + + + align:start position:0% +just wanted to take advantage of this +being up here to have you think about + + align:start position:0% +being up here to have you think about + + + align:start position:0% +being up here to have you think about +what this tells you about how close to + + align:start position:0% +what this tells you about how close to + + + align:start position:0% +what this tells you about how close to +linear this channel is and how close to + + align:start position:0% +linear this channel is and how close to + + + align:start position:0% +linear this channel is and how close to +time invariant it is what do you think + + align:start position:0% +time invariant it is what do you think + + + align:start position:0% +time invariant it is what do you think +what we're seeing here is for instance a + + align:start position:0% +what we're seeing here is for instance a + + + align:start position:0% +what we're seeing here is for instance a +step response to something that's at + + align:start position:0% +step response to something that's at + + + align:start position:0% +step response to something that's at +zero and then goes up to one and stays + + align:start position:0% +zero and then goes up to one and stays + + + align:start position:0% +zero and then goes up to one and stays +at one we're seeing a superposition of + + align:start position:0% +at one we're seeing a superposition of + + + align:start position:0% +at one we're seeing a superposition of +many such 021 transitions some 120 + + align:start position:0% +many such 021 transitions some 120 + + + align:start position:0% +many such 021 transitions some 120 +transitions later 120 transitions and so + + align:start position:0% +transitions later 120 transitions and so + + + align:start position:0% +transitions later 120 transitions and so +on right so we're really looking at a + + align:start position:0% +on right so we're really looking at a + + + align:start position:0% +on right so we're really looking at a +superposition of step responses + + align:start position:0% +superposition of step responses + + + align:start position:0% +superposition of step responses +staggered in time and going from 0 to + + align:start position:0% +staggered in time and going from 0 to + + + align:start position:0% +staggered in time and going from 0 to +100 120 do you think time and variances + + align:start position:0% +100 120 do you think time and variances + + + align:start position:0% +100 120 do you think time and variances +may be a good assumption for this + + align:start position:0% +may be a good assumption for this + + + align:start position:0% +may be a good assumption for this +channel plausible right because the step + + align:start position:0% +channel plausible right because the step + + + align:start position:0% +channel plausible right because the step +that we get here looks a lot like the + + align:start position:0% +that we get here looks a lot like the + + + align:start position:0% +that we get here looks a lot like the +step we're getting here the deviations + + align:start position:0% +step we're getting here the deviations + + + align:start position:0% +step we're getting here the deviations +might be noise but the more structured + + align:start position:0% +might be noise but the more structured + + + align:start position:0% +might be noise but the more structured +parts of the waveform here match the + + align:start position:0% +parts of the waveform here match the + + + align:start position:0% +parts of the waveform here match the +structured part of the waveform here and + + align:start position:0% +structured part of the waveform here and + + + align:start position:0% +structured part of the waveform here and +what you're really seeing is the the + + align:start position:0% +what you're really seeing is the the + + + align:start position:0% +what you're really seeing is the the +loudspeaker here reverberating through + + align:start position:0% +loudspeaker here reverberating through + + + align:start position:0% +loudspeaker here reverberating through +the room their eggs you're all staying + + align:start position:0% +the room their eggs you're all staying + + + align:start position:0% +the room their eggs you're all staying +fixed so the echoes are from fixed + + align:start position:0% +fixed so the echoes are from fixed + + + align:start position:0% +fixed so the echoes are from fixed +locations the walls are fixed and so + + align:start position:0% +locations the walls are fixed and so + + + align:start position:0% +locations the walls are fixed and so +what we're seeing is the step response + + align:start position:0% +what we're seeing is the step response + + + align:start position:0% +what we're seeing is the step response +of the room in effect and if you hit the + + align:start position:0% +of the room in effect and if you hit the + + + align:start position:0% +of the room in effect and if you hit the +room a little bit later while you get + + align:start position:0% +room a little bit later while you get + + + align:start position:0% +room a little bit later while you get +the same response but a little later + + align:start position:0% +the same response but a little later + + + align:start position:0% +the same response but a little later +does this look like it's very linear it + + align:start position:0% +does this look like it's very linear it + + + align:start position:0% +does this look like it's very linear it +would linearity the good assumption for + + align:start position:0% +would linearity the good assumption for + + + align:start position:0% +would linearity the good assumption for +this channel + + align:start position:0% + + + + align:start position:0% + +I mean this is very partial information + + align:start position:0% +I mean this is very partial information + + + align:start position:0% +I mean this is very partial information +but does it give you enough to to judge + + align:start position:0% +but does it give you enough to to judge + + + align:start position:0% +but does it give you enough to to judge +so why do you think it linearity might + + align:start position:0% +so why do you think it linearity might + + + align:start position:0% +so why do you think it linearity might +be good here were you saying yes it's a + + align:start position:0% +be good here were you saying yes it's a + + + align:start position:0% +be good here were you saying yes it's a +good assumption because what + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +but that's the time invariance argument + + align:start position:0% +but that's the time invariance argument + + + align:start position:0% +but that's the time invariance argument +that you're giving me what's a linearity + + align:start position:0% +that you're giving me what's a linearity + + + align:start position:0% +that you're giving me what's a linearity +argument yeah + + align:start position:0% + + + + align:start position:0% + +okay so when you scale so we're not + + align:start position:0% +okay so when you scale so we're not + + + align:start position:0% +okay so when you scale so we're not +really seeing too much while we are + + align:start position:0% +really seeing too much while we are + + + align:start position:0% +really seeing too much while we are +seeing scaling what kind of scaling are + + align:start position:0% +seeing scaling what kind of scaling are + + + align:start position:0% +seeing scaling what kind of scaling are +you seeing here we have zero to one + + align:start position:0% +you seeing here we have zero to one + + + align:start position:0% +you seeing here we have zero to one +transitions but we also have 120 kinds + + align:start position:0% +transitions but we also have 120 kinds + + + align:start position:0% +transitions but we also have 120 kinds +of transitions right what would you want + + align:start position:0% +of transitions right what would you want + + + align:start position:0% +of transitions right what would you want +to see for a linear channel for how the + + align:start position:0% +to see for a linear channel for how the + + + align:start position:0% +to see for a linear channel for how the +120 transition behaves relative to the + + align:start position:0% +120 transition behaves relative to the + + + align:start position:0% +120 transition behaves relative to the +zero to one transition what would you + + align:start position:0% +zero to one transition what would you + + + align:start position:0% +zero to one transition what would you +expect on the linear channel yeah so + + align:start position:0% +expect on the linear channel yeah so + + + align:start position:0% +expect on the linear channel yeah so +from superposition you would really + + align:start position:0% +from superposition you would really + + + align:start position:0% +from superposition you would really +expect to see the same shape on the + + align:start position:0% +expect to see the same shape on the + + + align:start position:0% +expect to see the same shape on the +downslope that you see on the upslope + + align:start position:0% +downslope that you see on the upslope + + + align:start position:0% +downslope that you see on the upslope +right so when you look at the upward + + align:start position:0% +right so when you look at the upward + + + align:start position:0% +right so when you look at the upward +transition here you see a certain shape + + align:start position:0% +transition here you see a certain shape + + + align:start position:0% +transition here you see a certain shape +well it's not quite matched on the + + align:start position:0% +well it's not quite matched on the + + + align:start position:0% +well it's not quite matched on the +downward slope here and the reason is + + align:start position:0% +downward slope here and the reason is + + + align:start position:0% +downward slope here and the reason is +that the particular simple demodulation + + align:start position:0% +that the particular simple demodulation + + + align:start position:0% +that the particular simple demodulation +we're using here for this on/off scheme + + align:start position:0% +we're using here for this on/off scheme + + + align:start position:0% +we're using here for this on/off scheme +actually makes that not look very linear + + align:start position:0% +actually makes that not look very linear + + + align:start position:0% +actually makes that not look very linear +for signals that are four channels that + + align:start position:0% +for signals that are four channels that + + + align:start position:0% +for signals that are four channels that +have this kind of an overshoot to them + + align:start position:0% +have this kind of an overshoot to them + + + align:start position:0% +have this kind of an overshoot to them +but the other scheme that Hari mentioned + + align:start position:0% +but the other scheme that Hari mentioned + + + align:start position:0% +but the other scheme that Hari mentioned +the quadrature demodulation will + + align:start position:0% +the quadrature demodulation will + + + align:start position:0% +the quadrature demodulation will +actually do a lot better we in fact saw + + align:start position:0% +actually do a lot better we in fact saw + + + align:start position:0% +actually do a lot better we in fact saw +that right we saw that there was + + align:start position:0% +that right we saw that there was + + + align:start position:0% +that right we saw that there was +modulation that essentially pulled out + + align:start position:0% +modulation that essentially pulled out + + + align:start position:0% +modulation that essentially pulled out +essentially pulled out the absolute + + align:start position:0% +essentially pulled out the absolute + + + align:start position:0% +essentially pulled out the absolute +value of what you were sending and then + + align:start position:0% +value of what you were sending and then + + + align:start position:0% +value of what you were sending and then +there was another modulation scheme that + + align:start position:0% +there was another modulation scheme that + + + align:start position:0% +there was another modulation scheme that +actually pulled out the signal itself + + align:start position:0% +actually pulled out the signal itself + + + align:start position:0% +actually pulled out the signal itself +and so if you if you're doing things + + align:start position:0% +and so if you if you're doing things + + + align:start position:0% +and so if you if you're doing things +like taking absolute value somewhere in + + align:start position:0% +like taking absolute value somewhere in + + + align:start position:0% +like taking absolute value somewhere in +the middle there then you're going to + + align:start position:0% +the middle there then you're going to + + + align:start position:0% +the middle there then you're going to +start losing the ability to model it as + + align:start position:0% +start losing the ability to model it as + + + align:start position:0% +start losing the ability to model it as +linear okay so linear time-invariant + + align:start position:0% +linear okay so linear time-invariant + + + align:start position:0% +linear okay so linear time-invariant +models are not necessarily good for all + + align:start position:0% +models are not necessarily good for all + + + align:start position:0% +models are not necessarily good for all +channels it's something that you've got + + align:start position:0% +channels it's something that you've got + + + align:start position:0% +channels it's something that you've got +to look for their good reasons to try + + align:start position:0% +to look for their good reasons to try + + + align:start position:0% +to look for their good reasons to try +and structure a channel so that it's + + align:start position:0% +and structure a channel so that it's + + + align:start position:0% +and structure a channel so that it's +close to linear and time invariant + + align:start position:0% +close to linear and time invariant + + + align:start position:0% +close to linear and time invariant +because then you can do a lot of + + align:start position:0% +because then you can do a lot of + + + align:start position:0% +because then you can do a lot of +analysis and design for it okay so I + + align:start position:0% +analysis and design for it okay so I + + + align:start position:0% +analysis and design for it okay so I +want to continue talking about our + + align:start position:0% +want to continue talking about our + + + align:start position:0% +want to continue talking about our +models for LTI channels + + align:start position:0% +models for LTI channels + + + align:start position:0% +models for LTI channels +and still in the time domain next time + + align:start position:0% +and still in the time domain next time + + + align:start position:0% +and still in the time domain next time +we'll start to look at this in the + + align:start position:0% +we'll start to look at this in the + + + align:start position:0% +we'll start to look at this in the +frequency domain Hari mentioned + + align:start position:0% +frequency domain Hari mentioned + + + align:start position:0% +frequency domain Hari mentioned +frequency several times here so we're + + align:start position:0% +frequency several times here so we're + + + align:start position:0% +frequency several times here so we're +talking about an LTI channel linear + + align:start position:0% +talking about an LTI channel linear + + + align:start position:0% +talking about an LTI channel linear +time-invariant we talked about + + align:start position:0% +time-invariant we talked about + + + align:start position:0% +time-invariant we talked about +characterizing it by its unit sample + + align:start position:0% +characterizing it by its unit sample + + + align:start position:0% +characterizing it by its unit sample +response and so let's see unit sample + + align:start position:0% +response and so let's see unit sample + + + align:start position:0% +response and so let's see unit sample +response means put in a unit sample + + align:start position:0% +response means put in a unit sample + + + align:start position:0% +response means put in a unit sample +function you get out an output that + + align:start position:0% +function you get out an output that + + + align:start position:0% +function you get out an output that +you're going to call the unit sample + + align:start position:0% +you're going to call the unit sample + + + align:start position:0% +you're going to call the unit sample +response put in an input X n that is the + + align:start position:0% +response put in an input X n that is the + + + align:start position:0% +response put in an input X n that is the +summation of such things let's say x k + + align:start position:0% +summation of such things let's say x k + + + align:start position:0% +summation of such things let's say x k +delta of n minus k summed over all K + + align:start position:0% +delta of n minus k summed over all K + + + align:start position:0% +delta of n minus k summed over all K +right that's a general input represented + + align:start position:0% +right that's a general input represented + + + align:start position:0% +right that's a general input represented +as a weighted combination of unit + + align:start position:0% +as a weighted combination of unit + + + align:start position:0% +as a weighted combination of unit +samples well what comes out in that case + + align:start position:0% +samples well what comes out in that case + + + align:start position:0% +samples well what comes out in that case +what is y of n if we're talking about a + + align:start position:0% +what is y of n if we're talking about a + + + align:start position:0% +what is y of n if we're talking about a +linear time invariant systems and it's + + align:start position:0% +linear time invariant systems and it's + + + align:start position:0% +linear time invariant systems and it's +the same weighted combination of the + + align:start position:0% +the same weighted combination of the + + + align:start position:0% +the same weighted combination of the +responses to these unit samples so we're + + align:start position:0% +responses to these unit samples so we're + + + align:start position:0% +responses to these unit samples so we're +going to get summation XK H of n minus K + + align:start position:0% +going to get summation XK H of n minus K + + + align:start position:0% +going to get summation XK H of n minus K +right so this is the convolution + + align:start position:0% +right so this is the convolution + + + align:start position:0% +right so this is the convolution +expression that we talked about last + + align:start position:0% +expression that we talked about last + + + align:start position:0% +expression that we talked about last +time so what I want to do in the rest of + + align:start position:0% +time so what I want to do in the rest of + + + align:start position:0% +time so what I want to do in the rest of +how the lecturers give you some other + + align:start position:0% +how the lecturers give you some other + + + align:start position:0% +how the lecturers give you some other +ways to think about this + + align:start position:0% + + + + align:start position:0% + +our notation for this was y of n equals + + align:start position:0% +our notation for this was y of n equals + + + align:start position:0% +our notation for this was y of n equals +x convolved with H evaluated a time n + + align:start position:0% +x convolved with H evaluated a time n + + + align:start position:0% +x convolved with H evaluated a time n +right + + align:start position:0% + + + + align:start position:0% + +another way to think about this let's + + align:start position:0% +another way to think about this let's + + + align:start position:0% +another way to think about this let's +see let me actually first do an example + + align:start position:0% +see let me actually first do an example + + + align:start position:0% +see let me actually first do an example +and then give you another way to think + + align:start position:0% +and then give you another way to think + + + align:start position:0% +and then give you another way to think +about this suppose I have a system whose + + align:start position:0% +about this suppose I have a system whose + + + align:start position:0% +about this suppose I have a system whose +effect is to multiply the input by a + + align:start position:0% +effect is to multiply the input by a + + + align:start position:0% +effect is to multiply the input by a +some number a and delay by some number D + + align:start position:0% +some number a and delay by some number D + + + align:start position:0% +some number a and delay by some number D +and I tell you that this is Lt I + + align:start position:0% +and I tell you that this is Lt I + + + align:start position:0% +and I tell you that this is Lt I +actually I don't have to tell you that + + align:start position:0% +actually I don't have to tell you that + + + align:start position:0% +actually I don't have to tell you that +it's LTI you can prove that it's LTI if + + align:start position:0% +it's LTI you can prove that it's LTI if + + + align:start position:0% +it's LTI you can prove that it's LTI if +I tell you have a system there's only + + align:start position:0% +I tell you have a system there's only + + + align:start position:0% +I tell you have a system there's only +action on the input is to delay the + + align:start position:0% +action on the input is to delay the + + + align:start position:0% +action on the input is to delay the +input by capital d and multiply the end + + align:start position:0% +input by capital d and multiply the end + + + align:start position:0% +input by capital d and multiply the end +scale the input by capital A you can + + align:start position:0% +scale the input by capital A you can + + + align:start position:0% +scale the input by capital A you can +actually prove that it satisfies time + + align:start position:0% +actually prove that it satisfies time + + + align:start position:0% +actually prove that it satisfies time +and variance and that it that you can + + align:start position:0% +and variance and that it that you can + + + align:start position:0% +and variance and that it that you can +superpose okay so this is Lt I so what's + + align:start position:0% +superpose okay so this is Lt I so what's + + + align:start position:0% +superpose okay so this is Lt I so what's +the unit sample response if i put in + + align:start position:0% +the unit sample response if i put in + + + align:start position:0% +the unit sample response if i put in +unit sample function of the input what's + + align:start position:0% +unit sample function of the input what's + + + align:start position:0% +unit sample function of the input what's +the output + + align:start position:0% + + + + align:start position:0% + +anyone + + align:start position:0% + + + + align:start position:0% + +yeah a dolt of n minus T right and if I + + align:start position:0% +yeah a dolt of n minus T right and if I + + + align:start position:0% +yeah a dolt of n minus T right and if I +put some general input function in here + + align:start position:0% +put some general input function in here + + + align:start position:0% +put some general input function in here +what's the output + + align:start position:0% + + + + align:start position:0% + +without telling me about convolution + + align:start position:0% +without telling me about convolution + + + align:start position:0% +without telling me about convolution +somebody I heard a voice here yeah right + + align:start position:0% + + + + align:start position:0% + +we didn't have to do any convolution to + + align:start position:0% +we didn't have to do any convolution to + + + align:start position:0% +we didn't have to do any convolution to +figure this out right because I describe + + align:start position:0% +figure this out right because I describe + + + align:start position:0% +figure this out right because I describe +the system to you in a simple way you + + align:start position:0% +the system to you in a simple way you + + + align:start position:0% +the system to you in a simple way you +could tell me what it does to the output + + align:start position:0% +could tell me what it does to the output + + + align:start position:0% +could tell me what it does to the output +all right so I want to give you another + + align:start position:0% +all right so I want to give you another + + + align:start position:0% +all right so I want to give you another +way to think about a system with the + + align:start position:0% +way to think about a system with the + + + align:start position:0% +way to think about a system with the +unit sample response of H of n so I'm + + align:start position:0% +unit sample response of H of n so I'm + + + align:start position:0% +unit sample response of H of n so I'm +talking about a youth system with the + + align:start position:0% +talking about a youth system with the + + + align:start position:0% +talking about a youth system with the +unit sample response to H of n so what + + align:start position:0% +unit sample response to H of n so what + + + align:start position:0% +unit sample response to H of n so what +does that mean that means at a time 0 I + + align:start position:0% +does that mean that means at a time 0 I + + + align:start position:0% +does that mean that means at a time 0 I +get evaluate 0 when I put out and put in + + align:start position:0% +get evaluate 0 when I put out and put in + + + align:start position:0% +get evaluate 0 when I put out and put in +a unit sample at time 1 I get some h1 a + + align:start position:0% +a unit sample at time 1 I get some h1 a + + + align:start position:0% +a unit sample at time 1 I get some h1 a +time to I get some h 2 and so on this is + + align:start position:0% +time to I get some h 2 and so on this is + + + align:start position:0% +time to I get some h 2 and so on this is +HN ok so if I give you a system and tell + + align:start position:0% +HN ok so if I give you a system and tell + + + align:start position:0% +HN ok so if I give you a system and tell +you that the unit sample response is + + align:start position:0% +you that the unit sample response is + + + align:start position:0% +you that the unit sample response is +this function H here's a way to think of + + align:start position:0% +this function H here's a way to think of + + + align:start position:0% +this function H here's a way to think of +what it is inside there here's what my + + align:start position:0% +what it is inside there here's what my + + + align:start position:0% +what it is inside there here's what my +system can be thought of as doing inside + + align:start position:0% +system can be thought of as doing inside + + + align:start position:0% +system can be thought of as doing inside +here I've got many parallel paths of God + + align:start position:0% +here I've got many parallel paths of God + + + align:start position:0% +here I've got many parallel paths of God +a system that scales by 80 + + align:start position:0% + + + + align:start position:0% + +delays by zero and in parallel with the + + align:start position:0% +delays by zero and in parallel with the + + + align:start position:0% +delays by zero and in parallel with the +system that scales by you put it up here + + align:start position:0% + + + + align:start position:0% + +scales by h1 delay by one and so on okay + + align:start position:0% +scales by h1 delay by one and so on okay + + + align:start position:0% +scales by h1 delay by one and so on okay +so all of these in parallel each one is + + align:start position:0% +so all of these in parallel each one is + + + align:start position:0% +so all of these in parallel each one is +very simple each one is as simple as the + + align:start position:0% +very simple each one is as simple as the + + + align:start position:0% +very simple each one is as simple as the +example I showed you okay I've got a + + align:start position:0% +example I showed you okay I've got a + + + align:start position:0% +example I showed you okay I've got a +whole bunch of these parallel systems + + align:start position:0% +whole bunch of these parallel systems + + + align:start position:0% +whole bunch of these parallel systems +each one as simple as this if I put a + + align:start position:0% +each one as simple as this if I put a + + + align:start position:0% +each one as simple as this if I put a +unit sample in here what comes out it's + + align:start position:0% +unit sample in here what comes out it's + + + align:start position:0% +unit sample in here what comes out it's +going to be exactly that right because + + align:start position:0% +going to be exactly that right because + + + align:start position:0% +going to be exactly that right because +the unit sample would get scaled by zero + + align:start position:0% +the unit sample would get scaled by zero + + + align:start position:0% +the unit sample would get scaled by zero +delayed by nothing will come out there + + align:start position:0% +delayed by nothing will come out there + + + align:start position:0% +delayed by nothing will come out there +the unit sample get through this path + + align:start position:0% +the unit sample get through this path + + + align:start position:0% +the unit sample get through this path +scaled by h1 delayed by one come out + + align:start position:0% +scaled by h1 delayed by one come out + + + align:start position:0% +scaled by h1 delayed by one come out +there when you assemble all of these + + align:start position:0% +there when you assemble all of these + + + align:start position:0% +there when you assemble all of these +with this summer here you're going to + + align:start position:0% +with this summer here you're going to + + + align:start position:0% +with this summer here you're going to +get exactly that response so here's + + align:start position:0% +get exactly that response so here's + + + align:start position:0% +get exactly that response so here's +another way to think about what's + + align:start position:0% +another way to think about what's + + + align:start position:0% +another way to think about what's +sitting inside a system an LTI system + + align:start position:0% +sitting inside a system an LTI system + + + align:start position:0% +sitting inside a system an LTI system +whose unit sample response is given to + + align:start position:0% +whose unit sample response is given to + + + align:start position:0% +whose unit sample response is given to +be that ok so if i put x an in what is + + align:start position:0% +be that ok so if i put x an in what is + + + align:start position:0% +be that ok so if i put x an in what is +it that's going to come out + + align:start position:0% + + + + align:start position:0% + +if i put x n in what comes out well + + align:start position:0% +if i put x n in what comes out well + + + align:start position:0% +if i put x n in what comes out well +through this path i get XM scale by zero + + align:start position:0% +through this path i get XM scale by zero + + + align:start position:0% +through this path i get XM scale by zero +and delayed by nothing through this path + + align:start position:0% +and delayed by nothing through this path + + + align:start position:0% +and delayed by nothing through this path +i get x n scale by h1 and delayed by one + + align:start position:0% +i get x n scale by h1 and delayed by one + + + align:start position:0% +i get x n scale by h1 and delayed by one +and so on so what comes out y of n is + + align:start position:0% +and so on so what comes out y of n is + + + align:start position:0% +and so on so what comes out y of n is +equal to hm x of n minus n overall an ok + + align:start position:0% +equal to hm x of n minus n overall an ok + + + align:start position:0% +equal to hm x of n minus n overall an ok +so i take x n i shifted by nothing i + + align:start position:0% +so i take x n i shifted by nothing i + + + align:start position:0% +so i take x n i shifted by nothing i +scale by zero that's one of these terms + + align:start position:0% +scale by zero that's one of these terms + + + align:start position:0% +scale by zero that's one of these terms +the term corresponding to M equals zero + + align:start position:0% +the term corresponding to M equals zero + + + align:start position:0% +the term corresponding to M equals zero +i take x n scale it by h1 delay by one + + align:start position:0% +i take x n scale it by h1 delay by one + + + align:start position:0% +i take x n scale it by h1 delay by one +that gives me the term with M equals one + + align:start position:0% +that gives me the term with M equals one + + + align:start position:0% +that gives me the term with M equals one +so here's another way to write it ok + + align:start position:0% +so here's another way to write it ok + + + align:start position:0% +so here's another way to write it ok +last time I said that actually you can + + align:start position:0% +last time I said that actually you can + + + align:start position:0% +last time I said that actually you can +write convolution in this form or with + + align:start position:0% +write convolution in this form or with + + + align:start position:0% +write convolution in this form or with +the operation reversed so it actually + + align:start position:0% +the operation reversed so it actually + + + align:start position:0% +the operation reversed so it actually +doesn't matter which order you write + + align:start position:0% +doesn't matter which order you write + + + align:start position:0% +doesn't matter which order you write +things in this would be something you + + align:start position:0% +things in this would be something you + + + align:start position:0% +things in this would be something you +might write as h convolved with X at + + align:start position:0% +might write as h convolved with X at + + + align:start position:0% +might write as h convolved with X at +time n so two different ways of writing + + align:start position:0% +time n so two different ways of writing + + + align:start position:0% +time n so two different ways of writing +the convolution and two different ways + + align:start position:0% +the convolution and two different ways + + + align:start position:0% +the convolution and two different ways +of thinking about how the output gets + + align:start position:0% +of thinking about how the output gets + + + align:start position:0% +of thinking about how the output gets +represented that way you can easily get + + align:start position:0% +represented that way you can easily get + + + align:start position:0% +represented that way you can easily get +from one representation to the other by + + align:start position:0% +from one representation to the other by + + + align:start position:0% +from one representation to the other by +just making a change of variables like + + align:start position:0% +just making a change of variables like + + + align:start position:0% +just making a change of variables like +let n minus K equals M and you get from + + align:start position:0% +let n minus K equals M and you get from + + + align:start position:0% +let n minus K equals M and you get from +this representation to the other this is + + align:start position:0% +this representation to the other this is + + + align:start position:0% +this representation to the other this is +a more mechanistic way of thinking about + + align:start position:0% +a more mechanistic way of thinking about + + + align:start position:0% +a more mechanistic way of thinking about +why these two representations work ok so + + align:start position:0% +why these two representations work ok so + + + align:start position:0% +why these two representations work ok so +what that is a given let me show you how + + align:start position:0% +what that is a given let me show you how + + + align:start position:0% +what that is a given let me show you how +to + + align:start position:0% +to + + + align:start position:0% +to +actually carry out these operations + + align:start position:0% +actually carry out these operations + + + align:start position:0% +actually carry out these operations +graphically in either form here's a + + align:start position:0% +graphically in either form here's a + + + align:start position:0% +graphically in either form here's a +simple graphical way to think about + + align:start position:0% +simple graphical way to think about + + + align:start position:0% +simple graphical way to think about +what's going on + + align:start position:0% + + + + align:start position:0% + +so to determine why a time n this is the + + align:start position:0% +so to determine why a time n this is the + + + align:start position:0% +so to determine why a time n this is the +operation that I have to carry out all + + align:start position:0% +operation that I have to carry out all + + + align:start position:0% +operation that I have to carry out all +right so defined why at time n the + + align:start position:0% +right so defined why at time n the + + + align:start position:0% +right so defined why at time n the +output at time and I've got to find a + + align:start position:0% +output at time and I've got to find a + + + align:start position:0% +output at time and I've got to find a +way to implement this operation + + align:start position:0% + + + + align:start position:0% + +so how are we going to think of this + + align:start position:0% +so how are we going to think of this + + + align:start position:0% +so how are we going to think of this +graphically I want to sketch the signal + + align:start position:0% +graphically I want to sketch the signal + + + align:start position:0% +graphically I want to sketch the signal +X I want to sketch the signal h and then + + align:start position:0% +X I want to sketch the signal h and then + + + align:start position:0% +X I want to sketch the signal h and then +do something with these two signals to + + align:start position:0% +do something with these two signals to + + + align:start position:0% +do something with these two signals to +construct this okay so when I plot x and + + align:start position:0% +construct this okay so when I plot x and + + + align:start position:0% +construct this okay so when I plot x and +i plot h to implement this operation + + align:start position:0% +i plot h to implement this operation + + + align:start position:0% +i plot h to implement this operation +what's my what's the name of my time + + align:start position:0% +what's my what's the name of my time + + + align:start position:0% +what's my what's the name of my time +axis is it and that i'm going to stick + + align:start position:0% +axis is it and that i'm going to stick + + + align:start position:0% +axis is it and that i'm going to stick +here or k or what I want to implement + + align:start position:0% +here or k or what I want to implement + + + align:start position:0% +here or k or what I want to implement +this i want to draw these two time + + align:start position:0% +this i want to draw these two time + + + align:start position:0% +this i want to draw these two time +functions their functions of k right and + + align:start position:0% +functions their functions of k right and + + + align:start position:0% +functions their functions of k right and +it's just the number that i'm specifying + + align:start position:0% +it's just the number that i'm specifying + + + align:start position:0% +it's just the number that i'm specifying +here okay so on the k axis I'm going to + + align:start position:0% +here okay so on the k axis I'm going to + + + align:start position:0% +here okay so on the k axis I'm going to +take X and plot it so X is some time + + align:start position:0% +take X and plot it so X is some time + + + align:start position:0% +take X and plot it so X is some time +function here's my ex + + align:start position:0% + + + + align:start position:0% + +I want to label them all because I get + + align:start position:0% +I want to label them all because I get + + + align:start position:0% +I want to label them all because I get +crowded and just to keep things clean + + align:start position:0% +crowded and just to keep things clean + + + align:start position:0% +crowded and just to keep things clean +let's change colors here how am I going + + align:start position:0% +let's change colors here how am I going + + + align:start position:0% +let's change colors here how am I going +to plot H of n minus K well let's start + + align:start position:0% +to plot H of n minus K well let's start + + + align:start position:0% +to plot H of n minus K well let's start +thinking about the N equals 0 case so + + align:start position:0% +thinking about the N equals 0 case so + + + align:start position:0% +thinking about the N equals 0 case so +for n equals 0 I've got to plot H of + + align:start position:0% +for n equals 0 I've got to plot H of + + + align:start position:0% +for n equals 0 I've got to plot H of +minus K so how does H of minus K relate + + align:start position:0% +minus K so how does H of minus K relate + + + align:start position:0% +minus K so how does H of minus K relate +to the unit sample response H of K or + + align:start position:0% +to the unit sample response H of K or + + + align:start position:0% +to the unit sample response H of K or +hmm if I tell you that out of that I + + align:start position:0% +hmm if I tell you that out of that I + + + align:start position:0% +hmm if I tell you that out of that I +have a system we had an example up here + + align:start position:0% +have a system we had an example up here + + + align:start position:0% +have a system we had an example up here +didn't we I lost it if i tell you that i + + align:start position:0% +didn't we I lost it if i tell you that i + + + align:start position:0% +didn't we I lost it if i tell you that i +have a system with + + align:start position:0% + + + + align:start position:0% + +this unit sample response let's do + + align:start position:0% +this unit sample response let's do + + + align:start position:0% +this unit sample response let's do +something simple let's say that this is + + align:start position:0% +something simple let's say that this is + + + align:start position:0% +something simple let's say that this is +one half to the end okay four times u of + + align:start position:0% +one half to the end okay four times u of + + + align:start position:0% +one half to the end okay four times u of +n so for positive time it's kind of a + + align:start position:0% +n so for positive time it's kind of a + + + align:start position:0% +n so for positive time it's kind of a +decaying geometric series and for- time + + align:start position:0% +decaying geometric series and for- time + + + align:start position:0% +decaying geometric series and for- time +at zero okay so that's an example of an + + align:start position:0% +at zero okay so that's an example of an + + + align:start position:0% +at zero okay so that's an example of an +unit sample response of a system so if + + align:start position:0% +unit sample response of a system so if + + + align:start position:0% +unit sample response of a system so if +that's H of n what does age of minus K + + align:start position:0% +that's H of n what does age of minus K + + + align:start position:0% +that's H of n what does age of minus K +look like yeah anyone sorry it's the + + align:start position:0% +look like yeah anyone sorry it's the + + + align:start position:0% +look like yeah anyone sorry it's the +reflection okay so if i want for N + + align:start position:0% +reflection okay so if i want for N + + + align:start position:0% +reflection okay so if i want for N +equals zero to plot just the age of + + align:start position:0% +equals zero to plot just the age of + + + align:start position:0% +equals zero to plot just the age of +minus K that I need here it's that + + align:start position:0% +minus K that I need here it's that + + + align:start position:0% +minus K that I need here it's that +reversed okay and plotted + + align:start position:0% + + + + align:start position:0% + +okay so this is h of minus K here what + + align:start position:0% +okay so this is h of minus K here what + + + align:start position:0% +okay so this is h of minus K here what +about H of minus k sorry what about H of + + align:start position:0% +about H of minus k sorry what about H of + + + align:start position:0% +about H of minus k sorry what about H of +n minus K suppose I had an equals 3 now + + align:start position:0% +n minus K suppose I had an equals 3 now + + + align:start position:0% +n minus K suppose I had an equals 3 now +how do I get h of 3 minus k + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% + + + + align:start position:0% + +so I want to get h of three minus K so + + align:start position:0% +so I want to get h of three minus K so + + + align:start position:0% +so I want to get h of three minus K so +that corresponds to sliding this over do + + align:start position:0% +that corresponds to sliding this over do + + + align:start position:0% +that corresponds to sliding this over do +I slide it to the right by three to the + + align:start position:0% +I slide it to the right by three to the + + + align:start position:0% +I slide it to the right by three to the +left by three + + align:start position:0% + + + + align:start position:0% + +you can tell by looking at the argument + + align:start position:0% +you can tell by looking at the argument + + + align:start position:0% +you can tell by looking at the argument +here whatever used to happen at zero has + + align:start position:0% +here whatever used to happen at zero has + + + align:start position:0% +here whatever used to happen at zero has +now got to happen at K equals 3 so that + + align:start position:0% +now got to happen at K equals 3 so that + + + align:start position:0% +now got to happen at K equals 3 so that +means the rightward shift ok so you flip + + align:start position:0% +means the rightward shift ok so you flip + + + align:start position:0% +means the rightward shift ok so you flip +this over and then you slide it by n + + align:start position:0% +this over and then you slide it by n + + + align:start position:0% +this over and then you slide it by n +steps ok so you take the h of k flip it + + align:start position:0% +steps ok so you take the h of k flip it + + + align:start position:0% +steps ok so you take the h of k flip it +around to get h of minus k slide it by n + + align:start position:0% +around to get h of minus k slide it by n + + + align:start position:0% +around to get h of minus k slide it by n +steps so if n is positive you're sliding + + align:start position:0% +steps so if n is positive you're sliding + + + align:start position:0% +steps so if n is positive you're sliding +it to the right if n is negative you're + + align:start position:0% +it to the right if n is negative you're + + + align:start position:0% +it to the right if n is negative you're +sliding it to the left so now you've on + + align:start position:0% +sliding it to the left so now you've on + + + align:start position:0% +sliding it to the left so now you've on +a single figure you've managed to plot + + align:start position:0% +a single figure you've managed to plot + + + align:start position:0% +a single figure you've managed to plot +these two what's the remaining operation + + align:start position:0% + + + + align:start position:0% + +which you've got to do is the point by + + align:start position:0% +which you've got to do is the point by + + + align:start position:0% +which you've got to do is the point by +point product of these two waveforms and + + align:start position:0% +point product of these two waveforms and + + + align:start position:0% +point product of these two waveforms and +some over the entire time axis it's like + + align:start position:0% +some over the entire time axis it's like + + + align:start position:0% +some over the entire time axis it's like +taking a dot product right so you're + + align:start position:0% +taking a dot product right so you're + + + align:start position:0% +taking a dot product right so you're +going to take this value of the red + + align:start position:0% +going to take this value of the red + + + align:start position:0% +going to take this value of the red +curve well actually let me slide it over + + align:start position:0% +curve well actually let me slide it over + + + align:start position:0% +curve well actually let me slide it over +let's let's do this case this is the + + align:start position:0% +let's let's do this case this is the + + + align:start position:0% +let's let's do this case this is the +slid over case right you're going to + + align:start position:0% +slid over case right you're going to + + + align:start position:0% +slid over case right you're going to +take every one of the purple values + + align:start position:0% +take every one of the purple values + + + align:start position:0% +take every one of the purple values +multiplied by the white and some over + + align:start position:0% +multiplied by the white and some over + + + align:start position:0% +multiplied by the white and some over +the entire time axis that's an + + align:start position:0% +the entire time axis that's an + + + align:start position:0% +the entire time axis that's an +implementation of this right so in + + align:start position:0% +implementation of this right so in + + + align:start position:0% +implementation of this right so in +recitation tomorrow you'll get practice + + align:start position:0% +recitation tomorrow you'll get practice + + + align:start position:0% +recitation tomorrow you'll get practice +on this that what you want to think of + + align:start position:0% +on this that what you want to think of + + + align:start position:0% +on this that what you want to think of +sort of the mantra for graphical + + align:start position:0% + + + + align:start position:0% + +implementation of convolution is you've + + align:start position:0% +implementation of convolution is you've + + + align:start position:0% +implementation of convolution is you've +got to do the flip of one of the time + + align:start position:0% +got to do the flip of one of the time + + + align:start position:0% +got to do the flip of one of the time +functions slide by n + + align:start position:0% +functions slide by n + + + align:start position:0% +functions slide by n +and then the dot product okay so you do + + align:start position:0% +and then the dot product okay so you do + + + align:start position:0% +and then the dot product okay so you do +you slide it to get one particular value + + align:start position:0% +you slide it to get one particular value + + + align:start position:0% +you slide it to get one particular value +of n if you want the next value of n you + + align:start position:0% +of n if you want the next value of n you + + + align:start position:0% +of n if you want the next value of n you +slide it one over and go through this + + align:start position:0% +slide it one over and go through this + + + align:start position:0% +slide it one over and go through this +whole thing so it's flipping sliding by + + align:start position:0% +whole thing so it's flipping sliding by + + + align:start position:0% +whole thing so it's flipping sliding by +the right number of spots doing the + + align:start position:0% +the right number of spots doing the + + + align:start position:0% +the right number of spots doing the +inner product that gives you one value + + align:start position:0% +inner product that gives you one value + + + align:start position:0% +inner product that gives you one value +of the answer and then you repeat all + + align:start position:0% +of the answer and then you repeat all + + + align:start position:0% +of the answer and then you repeat all +right you'll get more practice in + + align:start position:0% +right you'll get more practice in + + + align:start position:0% +right you'll get more practice in +recitation \ No newline at end of file diff --git a/fWOGfzC3IeY.txt b/fWOGfzC3IeY.txt new file mode 100644 index 0000000000000000000000000000000000000000..092f9b6255a1be4aefb2aced9fc8fdac99513e0b --- /dev/null +++ b/fWOGfzC3IeY.txt @@ -0,0 +1,1787 @@ +align:start position:0% + +welcome back to recitation in this video + + align:start position:0% +welcome back to recitation in this video + + + align:start position:0% +welcome back to recitation in this video +I want to show how we can use change of + + align:start position:0% +I want to show how we can use change of + + + align:start position:0% +I want to show how we can use change of +variables to Polar coordinates in + + align:start position:0% +variables to Polar coordinates in + + + align:start position:0% +variables to Polar coordinates in +particular to evaluate an integral that + + align:start position:0% +particular to evaluate an integral that + + + align:start position:0% +particular to evaluate an integral that +without the change in variables we we + + align:start position:0% +without the change in variables we we + + + align:start position:0% +without the change in variables we we +don't have the techniques to do so I'm + + align:start position:0% +don't have the techniques to do so I'm + + + align:start position:0% +don't have the techniques to do so I'm +going to show us how to evaluate the + + align:start position:0% +going to show us how to evaluate the + + + align:start position:0% +going to show us how to evaluate the +integral from minus infinity to Infinity + + align:start position:0% +integral from minus infinity to Infinity + + + align:start position:0% +integral from minus infinity to Infinity +of eus x^2 DX and I'll just point out + + align:start position:0% +of eus x^2 DX and I'll just point out + + + align:start position:0% +of eus x^2 DX and I'll just point out +that if you do anything in probability + + align:start position:0% +that if you do anything in probability + + + align:start position:0% +that if you do anything in probability +you will see + + align:start position:0% +you will see + + + align:start position:0% +you will see +uh this integral a great deal so this + + align:start position:0% +uh this integral a great deal so this + + + align:start position:0% +uh this integral a great deal so this +this is a distribution and you'll see it + + align:start position:0% +this is a distribution and you'll see it + + + align:start position:0% +this is a distribution and you'll see it +a great deal if you ever do anything in + + align:start position:0% +a great deal if you ever do anything in + + + align:start position:0% +a great deal if you ever do anything in +probability Theory but how are we going + + align:start position:0% +probability Theory but how are we going + + + align:start position:0% +probability Theory but how are we going +to use how are we going to use polar + + align:start position:0% +to use how are we going to use polar + + + align:start position:0% +to use how are we going to use polar +coordinates to evaluate this well the + + align:start position:0% +coordinates to evaluate this well the + + + align:start position:0% +coordinates to evaluate this well the +object is going to be to introduce uh a + + align:start position:0% +object is going to be to introduce uh a + + + align:start position:0% +object is going to be to introduce uh a +little bit more um into this integral so + + align:start position:0% +little bit more um into this integral so + + + align:start position:0% +little bit more um into this integral so +that when I when I actually introduce + + align:start position:0% +that when I when I actually introduce + + + align:start position:0% +that when I when I actually introduce +that in I'm going to have an R squ term + + align:start position:0% +that in I'm going to have an R squ term + + + align:start position:0% +that in I'm going to have an R squ term +in the exponent and I'm going to have of + + align:start position:0% +in the exponent and I'm going to have of + + + align:start position:0% +in the exponent and I'm going to have of +course by the change of variables in the + + align:start position:0% +course by the change of variables in the + + + align:start position:0% +course by the change of variables in the +Jacobian and multiplied by R and that's + + align:start position:0% +Jacobian and multiplied by R and that's + + + align:start position:0% +Jacobian and multiplied by R and that's +what's going to save us so let me + + align:start position:0% +what's going to save us so let me + + + align:start position:0% +what's going to save us so let me +actually just get right to it so I um + + align:start position:0% +actually just get right to it so I um + + + align:start position:0% +actually just get right to it so I um +I'm going to call this integral this + + align:start position:0% +I'm going to call this integral this + + + align:start position:0% +I'm going to call this integral this +quantity capital I we'll just call this + + align:start position:0% +quantity capital I we'll just call this + + + align:start position:0% +quantity capital I we'll just call this +quantity capital I and then what I'm + + align:start position:0% +quantity capital I and then what I'm + + + align:start position:0% +quantity capital I and then what I'm +going to do is introduce a couple more + + align:start position:0% +going to do is introduce a couple more + + + align:start position:0% +going to do is introduce a couple more +things so let me write it down and then + + align:start position:0% +things so let me write it down and then + + + align:start position:0% +things so let me write it down and then +I will justify that it's reasonable to + + align:start position:0% +I will justify that it's reasonable to + + + align:start position:0% +I will justify that it's reasonable to +even look at this thing and that it will + + align:start position:0% +even look at this thing and that it will + + + align:start position:0% +even look at this thing and that it will +give us something + + align:start position:0% + + + + align:start position:0% + +useful okay okay so I just took this + + align:start position:0% +useful okay okay so I just took this + + + align:start position:0% +useful okay okay so I just took this +integral and what I've done is I've now + + align:start position:0% +integral and what I've done is I've now + + + align:start position:0% +integral and what I've done is I've now +taken this quantity and I've and I've uh + + align:start position:0% +taken this quantity and I've and I've uh + + + align:start position:0% +taken this quantity and I've and I've uh +multiplied by an eus y^ 2 and then I'm + + align:start position:0% +multiplied by an eus y^ 2 and then I'm + + + align:start position:0% +multiplied by an eus y^ 2 and then I'm +now integrating from minus infinity to + + align:start position:0% +now integrating from minus infinity to + + + align:start position:0% +now integrating from minus infinity to +infinity and Dy also and what I want to + + align:start position:0% +infinity and Dy also and what I want to + + + align:start position:0% +infinity and Dy also and what I want to +point out that maybe isn't immediately + + align:start position:0% +point out that maybe isn't immediately + + + align:start position:0% +point out that maybe isn't immediately +obvious from the way it's written here + + align:start position:0% +obvious from the way it's written here + + + align:start position:0% +obvious from the way it's written here +but will be immediately obvious when I + + align:start position:0% +but will be immediately obvious when I + + + align:start position:0% +but will be immediately obvious when I +write it a different way is that this + + align:start position:0% +write it a different way is that this + + + align:start position:0% +write it a different way is that this +quantity is actually just the square of + + align:start position:0% +quantity is actually just the square of + + + align:start position:0% +quantity is actually just the square of +this quantity so it's actually just two + + align:start position:0% +this quantity so it's actually just two + + + align:start position:0% +this quantity so it's actually just two +of these multiplied together and let me + + align:start position:0% +of these multiplied together and let me + + + align:start position:0% +of these multiplied together and let me +point out why that is because this term + + align:start position:0% +point out why that is because this term + + + align:start position:0% +point out why that is because this term +right here can be Rewritten as e- x^2 + + align:start position:0% +right here can be Rewritten as e- x^2 + + + align:start position:0% +right here can be Rewritten as e- x^2 +eus + + align:start position:0% +eus + + + align:start position:0% +eus +y^2 and then I have two + + align:start position:0% +y^2 and then I have two + + + align:start position:0% +y^2 and then I have two +integrals which are from minus infinity + + align:start position:0% +integrals which are from minus infinity + + + align:start position:0% +integrals which are from minus infinity +to Infinity both sorry that one looks a + + align:start position:0% +to Infinity both sorry that one looks a + + + align:start position:0% +to Infinity both sorry that one looks a +little off kilter but those two + + align:start position:0% +little off kilter but those two + + + align:start position:0% +little off kilter but those two +integrals which I the the bounds are + + align:start position:0% +integrals which I the the bounds are + + + align:start position:0% +integrals which I the the bounds are +minus infinity to Infinity for both and + + align:start position:0% +minus infinity to Infinity for both and + + + align:start position:0% +minus infinity to Infinity for both and +then I have a DX and a + + align:start position:0% +then I have a DX and a + + + align:start position:0% +then I have a DX and a +Dy now the reason that it is just i s + + align:start position:0% +Dy now the reason that it is just i s + + + align:start position:0% +Dy now the reason that it is just i s +this quantity is just I squ is because + + align:start position:0% +this quantity is just I squ is because + + + align:start position:0% +this quantity is just I squ is because +because if you notice this first + + align:start position:0% +because if you notice this first + + + align:start position:0% +because if you notice this first +integral the inside integral this is + + align:start position:0% +integral the inside integral this is + + + align:start position:0% +integral the inside integral this is +independent of X so I can move it out so + + align:start position:0% +independent of X so I can move it out so + + + align:start position:0% +independent of X so I can move it out so +let me actually come up here and write + + align:start position:0% +let me actually come up here and write + + + align:start position:0% +let me actually come up here and write +that down so I can move it out and I can + + align:start position:0% +that down so I can move it out and I can + + + align:start position:0% +that down so I can move it out and I can +actually rewrite the integral and I'll + + align:start position:0% +actually rewrite the integral and I'll + + + align:start position:0% +actually rewrite the integral and I'll +put the bounds here because it's high up + + align:start position:0% +put the bounds here because it's high up + + + align:start position:0% +put the bounds here because it's high up +enough that I can actually write it eus + + align:start position:0% +enough that I can actually write it eus + + + align:start position:0% +enough that I can actually write it eus +y^ 2 and then integral from minus + + align:start position:0% +y^ 2 and then integral from minus + + + align:start position:0% +y^ 2 and then integral from minus +infinity to Infinity e to - + + align:start position:0% +infinity to Infinity e to - + + + align:start position:0% +infinity to Infinity e to - +x^2 DX Dy right so let's point out again + + align:start position:0% +x^2 DX Dy right so let's point out again + + + align:start position:0% +x^2 DX Dy right so let's point out again +what I did this quantity I circled was + + align:start position:0% +what I did this quantity I circled was + + + align:start position:0% +what I did this quantity I circled was +was a constant when I when I consider X + + align:start position:0% +was a constant when I when I consider X + + + align:start position:0% +was a constant when I when I consider X +the variable right in terms of X this is + + align:start position:0% +the variable right in terms of X this is + + + align:start position:0% +the variable right in terms of X this is +a constant so I can move it in front of + + align:start position:0% +a constant so I can move it in front of + + + align:start position:0% +a constant so I can move it in front of +that integral which is the DX integral + + align:start position:0% +that integral which is the DX integral + + + align:start position:0% +that integral which is the DX integral +and so now what do I see well this + + align:start position:0% +and so now what do I see well this + + + align:start position:0% +and so now what do I see well this +quantity is what I've called I and so + + align:start position:0% +quantity is what I've called I and so + + + align:start position:0% +quantity is what I've called I and so +now that's a constant so I can move that + + align:start position:0% +now that's a constant so I can move that + + + align:start position:0% +now that's a constant so I can move that +out to the front that's a constant + + align:start position:0% +out to the front that's a constant + + + align:start position:0% +out to the front that's a constant +that's I as designated and so now I have + + align:start position:0% +that's I as designated and so now I have + + + align:start position:0% +that's I as designated and so now I have +the integral from minus infinity to + + align:start position:0% +the integral from minus infinity to + + + align:start position:0% +the integral from minus infinity to +Infinity of eus y^2 + + align:start position:0% +Infinity of eus y^2 + + + align:start position:0% +Infinity of eus y^2 +Y and then that again is another I + + align:start position:0% +Y and then that again is another I + + + align:start position:0% +Y and then that again is another I +because if you notice I mean this was e- + + align:start position:0% +because if you notice I mean this was e- + + + align:start position:0% +because if you notice I mean this was e- +x^2 DX and so if I keep this as eus y^2 + + align:start position:0% +x^2 DX and so if I keep this as eus y^2 + + + align:start position:0% +x^2 DX and so if I keep this as eus y^2 +Dy it's going to be exactly the same + + align:start position:0% +Dy it's going to be exactly the same + + + align:start position:0% +Dy it's going to be exactly the same +value so this is actually equal to + + align:start position:0% +value so this is actually equal to + + + align:start position:0% +value so this is actually equal to +i^2 so the point I want to make if you + + align:start position:0% +i^2 so the point I want to make if you + + + align:start position:0% +i^2 so the point I want to make if you +come back over here to this to this + + align:start position:0% + + + + align:start position:0% + +integral is is that this quantity I'm + + align:start position:0% +integral is is that this quantity I'm + + + align:start position:0% +integral is is that this quantity I'm +going to be able to integrate very + + align:start position:0% +going to be able to integrate very + + + align:start position:0% +going to be able to integrate very +easily and when I do that if I take the + + align:start position:0% +easily and when I do that if I take the + + + align:start position:0% +easily and when I do that if I take the +square root I'm going to get this + + align:start position:0% +square root I'm going to get this + + + align:start position:0% +square root I'm going to get this +value because I just showed this thing + + align:start position:0% +value because I just showed this thing + + + align:start position:0% +value because I just showed this thing +in the Box was equal to i s all right so + + align:start position:0% +in the Box was equal to i s all right so + + + align:start position:0% +in the Box was equal to i s all right so +let me write it down uh on this last + + align:start position:0% +let me write it down uh on this last + + + align:start position:0% +let me write it down uh on this last +part of the board I will write down that + + align:start position:0% +part of the board I will write down that + + + align:start position:0% +part of the board I will write down that +thing again and then we'll actually + + align:start position:0% +thing again and then we'll actually + + + align:start position:0% +thing again and then we'll actually +evaluate it and we'll see what we + + align:start position:0% +evaluate it and we'll see what we + + + align:start position:0% +evaluate it and we'll see what we +get so let me rewrite this is the thing + + align:start position:0% +get so let me rewrite this is the thing + + + align:start position:0% +get so let me rewrite this is the thing +we want to evaluate + + align:start position:0% + + + + align:start position:0% + +and I'm going to remind myself that + + align:start position:0% +and I'm going to remind myself that + + + align:start position:0% +and I'm going to remind myself that +that's equal to i^2 i^2 is equal to this + + align:start position:0% +that's equal to i^2 i^2 is equal to this + + + align:start position:0% +that's equal to i^2 i^2 is equal to this +quantity and I mentioned at the + + align:start position:0% +quantity and I mentioned at the + + + align:start position:0% +quantity and I mentioned at the +beginning that we're going to use a + + align:start position:0% +beginning that we're going to use a + + + align:start position:0% +beginning that we're going to use a +trick we're going to change variables + + align:start position:0% +trick we're going to change variables + + + align:start position:0% +trick we're going to change variables +into Polar coordinates and so notice + + align:start position:0% +into Polar coordinates and so notice + + + align:start position:0% +into Polar coordinates and so notice +that the region we're integrating over + + align:start position:0% +that the region we're integrating over + + + align:start position:0% +that the region we're integrating over +is the entire XY plane and in polar + + align:start position:0% +is the entire XY plane and in polar + + + align:start position:0% +is the entire XY plane and in polar +coordinates what's that going to be + + align:start position:0% +coordinates what's that going to be + + + align:start position:0% +coordinates what's that going to be +Theta is going to run from zero all the + + align:start position:0% +Theta is going to run from zero all the + + + align:start position:0% +Theta is going to run from zero all the +way around to 2 pi and R is going to run + + align:start position:0% +way around to 2 pi and R is going to run + + + align:start position:0% +way around to 2 pi and R is going to run +from zero to infinity and so those will + + align:start position:0% +from zero to infinity and so those will + + + align:start position:0% +from zero to infinity and so those will +be our bounds for R and Theta because if + + align:start position:0% +be our bounds for R and Theta because if + + + align:start position:0% +be our bounds for R and Theta because if +you want to get the entire XY plane in + + align:start position:0% +you want to get the entire XY plane in + + + align:start position:0% +you want to get the entire XY plane in +terms of R and Theta that is what you + + align:start position:0% +terms of R and Theta that is what you + + + align:start position:0% +terms of R and Theta that is what you +have to + + align:start position:0% +have to + + + align:start position:0% +have to +do and I want to mention also what is + + align:start position:0% +do and I want to mention also what is + + + align:start position:0% +do and I want to mention also what is +this quantity going to become in terms + + align:start position:0% +this quantity going to become in terms + + + align:start position:0% +this quantity going to become in terms +of R and Theta well notice that this is + + align:start position:0% +of R and Theta well notice that this is + + + align:start position:0% +of R and Theta well notice that this is +e- x^2 - y^2 it's just really e to the + + align:start position:0% +e- x^2 - y^2 it's just really e to the + + + align:start position:0% +e- x^2 - y^2 it's just really e to the +minus quantity x^2 + y^2 it's really e + + align:start position:0% +minus quantity x^2 + y^2 it's really e + + + align:start position:0% +minus quantity x^2 + y^2 it's really e +to Theus R 2 so what we get when we do a + + align:start position:0% +to Theus R 2 so what we get when we do a + + + align:start position:0% +to Theus R 2 so what we get when we do a +change of change of variables as we do + + align:start position:0% +change of change of variables as we do + + + align:start position:0% +change of change of variables as we do +uh I'll put the Theta on the I'll put + + align:start position:0% +uh I'll put the Theta on the I'll put + + + align:start position:0% +uh I'll put the Theta on the I'll put +the Theta on the inside actually because + + align:start position:0% +the Theta on the inside actually because + + + align:start position:0% +the Theta on the inside actually because +that'll be easy to do first so the r is + + align:start position:0% +that'll be easy to do first so the r is + + + align:start position:0% +that'll be easy to do first so the r is +going to be on the outside the Theta is + + align:start position:0% +going to be on the outside the Theta is + + + align:start position:0% +going to be on the outside the Theta is +going to be on the inside and then e + + align:start position:0% +going to be on the inside and then e + + + align:start position:0% +going to be on the inside and then e +Theus R 2 that's a direct substitution + + align:start position:0% +Theus R 2 that's a direct substitution + + + align:start position:0% +Theus R 2 that's a direct substitution +x^2 + y^2 = r^2 and then I get r d Theta + + align:start position:0% +x^2 + y^2 = r^2 and then I get r d Theta + + + align:start position:0% +x^2 + y^2 = r^2 and then I get r d Theta +Dr and this comes from the Jacobian that + + align:start position:0% +Dr and this comes from the Jacobian that + + + align:start position:0% +Dr and this comes from the Jacobian that +you computed I believe in in lecture + + align:start position:0% +you computed I believe in in lecture + + + align:start position:0% +you computed I believe in in lecture +even uh to show how you change from XY + + align:start position:0% +even uh to show how you change from XY + + + align:start position:0% +even uh to show how you change from XY +variables to R Theta variables and I put + + align:start position:0% +variables to R Theta variables and I put + + + align:start position:0% +variables to R Theta variables and I put +the D Theta first here because I wanted + + align:start position:0% +the D Theta first here because I wanted + + + align:start position:0% +the D Theta first here because I wanted +to integrate in Theta first and the + + align:start position:0% +to integrate in Theta first and the + + + align:start position:0% +to integrate in Theta first and the +reason I want to integrate in Theta + + align:start position:0% +reason I want to integrate in Theta + + + align:start position:0% +reason I want to integrate in Theta +first is notice that because nothing + + align:start position:0% +first is notice that because nothing + + + align:start position:0% +first is notice that because nothing +here depends on Theta all I pick up is a + + align:start position:0% +here depends on Theta all I pick up is a + + + align:start position:0% +here depends on Theta all I pick up is a +2 pi I just pick up when I integrate I + + align:start position:0% +2 pi I just pick up when I integrate I + + + align:start position:0% +2 pi I just pick up when I integrate I +get a Theta I evaluate it at 2 pi and + + align:start position:0% +get a Theta I evaluate it at 2 pi and + + + align:start position:0% +get a Theta I evaluate it at 2 pi and +then I evaluate it at zero and I take + + align:start position:0% +then I evaluate it at zero and I take + + + align:start position:0% +then I evaluate it at zero and I take +the difference and so if I do that line + + align:start position:0% +the difference and so if I do that line + + + align:start position:0% +the difference and so if I do that line +all I get is well I should probably + + align:start position:0% +all I get is well I should probably + + + align:start position:0% +all I get is well I should probably +write it in front all I get is 2 pi from + + align:start position:0% +write it in front all I get is 2 pi from + + + align:start position:0% +write it in front all I get is 2 pi from +the Theta and then the integral from + + align:start position:0% +the Theta and then the integral from + + + align:start position:0% +the Theta and then the integral from +zero to + + align:start position:0% +zero to + + + align:start position:0% +zero to +Infinity eus r^ 2 * r d r now this isn't + + align:start position:0% +Infinity eus r^ 2 * r d r now this isn't + + + align:start position:0% +Infinity eus r^ 2 * r d r now this isn't +much easier quantity to evaluate than + + align:start position:0% +much easier quantity to evaluate than + + + align:start position:0% +much easier quantity to evaluate than +eus x^2 DX if because now we have an R + + align:start position:0% +eus x^2 DX if because now we have an R + + + align:start position:0% +eus x^2 DX if because now we have an R +here so now it's a natural substitution + + align:start position:0% +here so now it's a natural substitution + + + align:start position:0% +here so now it's a natural substitution +type of problem and we can do it right + + align:start position:0% +type of problem and we can do it right + + + align:start position:0% +type of problem and we can do it right +away I'm going to write it down and then + + align:start position:0% +away I'm going to write it down and then + + + align:start position:0% +away I'm going to write it down and then +we'll check and make sure I didn't make + + align:start position:0% +we'll check and make sure I didn't make + + + align:start position:0% +we'll check and make sure I didn't make +a mistake we should get something like + + align:start position:0% +a mistake we should get something like + + + align:start position:0% +a mistake we should get something like +eus r^ + + align:start position:0% +eus r^ + + + align:start position:0% +eus r^ +2 over 2 with a negative sign in front + + align:start position:0% +2 over 2 with a negative sign in front + + + align:start position:0% +2 over 2 with a negative sign in front +so let me make sure when I take this + + align:start position:0% +so let me make sure when I take this + + + align:start position:0% +so let me make sure when I take this +derivative you could just do a + + align:start position:0% +derivative you could just do a + + + align:start position:0% +derivative you could just do a +substitution to check but you should get + + align:start position:0% +substitution to check but you should get + + + align:start position:0% +substitution to check but you should get +exactly this kind of thing I take the + + align:start position:0% +exactly this kind of thing I take the + + + align:start position:0% +exactly this kind of thing I take the +derivative of eus r^ 2 I get a + + align:start position:0% +derivative of eus r^ 2 I get a + + + align:start position:0% +derivative of eus r^ 2 I get a +-2r and then uh did I do something wrong + + align:start position:0% +-2r and then uh did I do something wrong + + + align:start position:0% +-2r and then uh did I do something wrong +here oh yeah I'm good I get a + + align:start position:0% +here oh yeah I'm good I get a + + + align:start position:0% +here oh yeah I'm good I get a +-2r and so the negatives kill off the + + align:start position:0% +-2r and so the negatives kill off the + + + align:start position:0% +-2r and so the negatives kill off the +twos divide out and I get my e to the + + align:start position:0% +twos divide out and I get my e to the + + + align:start position:0% +twos divide out and I get my e to the +minus r^ 2 * R so that's good and now I + + align:start position:0% +minus r^ 2 * R so that's good and now I + + + align:start position:0% +minus r^ 2 * R so that's good and now I +have to evaluate it at the + + align:start position:0% +have to evaluate it at the + + + align:start position:0% +have to evaluate it at the +bounds so again this was much easier to + + align:start position:0% +bounds so again this was much easier to + + + align:start position:0% +bounds so again this was much easier to +evaluate if I if I let uh if I do a + + align:start position:0% +evaluate if I if I let uh if I do a + + + align:start position:0% +evaluate if I if I let uh if I do a +substitution and I let uh + + align:start position:0% +substitution and I let uh + + + align:start position:0% +substitution and I let uh +R I think I want to let R2 equal U or + + align:start position:0% +R I think I want to let R2 equal U or + + + align:start position:0% +R I think I want to let R2 equal U or +something like this I don't even know I + + align:start position:0% +something like this I don't even know I + + + align:start position:0% +something like this I don't even know I +just did the substitution without + + align:start position:0% +just did the substitution without + + + align:start position:0% +just did the substitution without +thinking about it so you can figure out + + align:start position:0% +thinking about it so you can figure out + + + align:start position:0% +thinking about it so you can figure out +what you need to substitute but this is + + align:start position:0% +what you need to substitute but this is + + + align:start position:0% +what you need to substitute but this is +what you get and so let me actually just + + align:start position:0% +what you get and so let me actually just + + + align:start position:0% +what you get and so let me actually just +evaluate at the bounds and see what + + align:start position:0% +evaluate at the bounds and see what + + + align:start position:0% +evaluate at the bounds and see what +happens so as R goes to Infinity I get e + + align:start position:0% +happens so as R goes to Infinity I get e + + + align:start position:0% +happens so as R goes to Infinity I get e +to the minus r 2 as R goes to Infinity + + align:start position:0% +to the minus r 2 as R goes to Infinity + + + align:start position:0% +to the minus r 2 as R goes to Infinity +uh e to the minus r squ goes to zero and + + align:start position:0% +uh e to the minus r squ goes to zero and + + + align:start position:0% +uh e to the minus r squ goes to zero and +so the first term is zero when I + + align:start position:0% +so the first term is zero when I + + + align:start position:0% +so the first term is zero when I +evaluate and then so the second term I + + align:start position:0% +evaluate and then so the second term I + + + align:start position:0% +evaluate and then so the second term I +get is I do 0 minus 2 pi times if I + + align:start position:0% +get is I do 0 minus 2 pi times if I + + + align:start position:0% +get is I do 0 minus 2 pi times if I +evaluate at e to the 0o I get 1 so I + + align:start position:0% +evaluate at e to the 0o I get 1 so I + + + align:start position:0% +evaluate at e to the 0o I get 1 so I +get1 / 2 right the negative one comes + + align:start position:0% +get1 / 2 right the negative one comes + + + align:start position:0% +get1 / 2 right the negative one comes +from e to the zero right and then I + + align:start position:0% +from e to the zero right and then I + + + align:start position:0% +from e to the zero right and then I +divide by two so I get my two there so a + + align:start position:0% +divide by two so I get my two there so a + + + align:start position:0% +divide by two so I get my two there so a +negative and a negative gives me a + + align:start position:0% +negative and a negative gives me a + + + align:start position:0% +negative and a negative gives me a +positive two divided two and so the + + align:start position:0% +positive two divided two and so the + + + align:start position:0% +positive two divided two and so the +whole thing equals + + align:start position:0% +whole thing equals + + + align:start position:0% +whole thing equals +Pi just enough room and so I just want + + align:start position:0% +Pi just enough room and so I just want + + + align:start position:0% +Pi just enough room and so I just want +to remind us where we came from we came + + align:start position:0% +to remind us where we came from we came + + + align:start position:0% +to remind us where we came from we came +from PI we we wanted to uh show was + + align:start position:0% +from PI we we wanted to uh show was + + + align:start position:0% +from PI we we wanted to uh show was +equal we well the pi where did it come + + align:start position:0% +equal we well the pi where did it come + + + align:start position:0% +equal we well the pi where did it come +from it's equal if we go all the way + + align:start position:0% +from it's equal if we go all the way + + + align:start position:0% +from it's equal if we go all the way +back up to i^ + + align:start position:0% +back up to i^ + + + align:start position:0% +back up to i^ +S and so we wanted to show what I was + + align:start position:0% +S and so we wanted to show what I was + + + align:start position:0% +S and so we wanted to show what I was +equal to I then is equal to just the + + align:start position:0% +equal to I then is equal to just the + + + align:start position:0% +equal to I then is equal to just the +square root of Pi so I can come back + + align:start position:0% +square root of Pi so I can come back + + + align:start position:0% +square root of Pi so I can come back +over to where I started which is over + + align:start position:0% +over to where I started which is over + + + align:start position:0% +over to where I started which is over +here and I can say this is equal to the + + align:start position:0% +here and I can say this is equal to the + + + align:start position:0% +here and I can say this is equal to the +square root of + + align:start position:0% +square root of + + + align:start position:0% +square root of +Pi and again I just want to mention what + + align:start position:0% +Pi and again I just want to mention what + + + align:start position:0% +Pi and again I just want to mention what +it came down to came down to introducing + + align:start position:0% +it came down to came down to introducing + + + align:start position:0% +it came down to came down to introducing +a little bit more essentially we we took + + align:start position:0% +a little bit more essentially we we took + + + align:start position:0% +a little bit more essentially we we took +something that was a single variable + + align:start position:0% +something that was a single variable + + + align:start position:0% +something that was a single variable +problem we made it a multivariable + + align:start position:0% +problem we made it a multivariable + + + align:start position:0% +problem we made it a multivariable +problem but what that allowed us to do + + align:start position:0% +problem but what that allowed us to do + + + align:start position:0% +problem but what that allowed us to do +is to do a change of coordinates from XY + + align:start position:0% +is to do a change of coordinates from XY + + + align:start position:0% +is to do a change of coordinates from XY +into the polar coordinate system and the + + align:start position:0% +into the polar coordinate system and the + + + align:start position:0% +into the polar coordinate system and the +trick here as you come through the trick + + align:start position:0% +trick here as you come through the trick + + + align:start position:0% +trick here as you come through the trick +where it actually happens is right here + + align:start position:0% +where it actually happens is right here + + + align:start position:0% +where it actually happens is right here +is because this is easy to integrate now + + align:start position:0% +is because this is easy to integrate now + + + align:start position:0% +is because this is easy to integrate now +that I have an R here okay if I didn't + + align:start position:0% +that I have an R here okay if I didn't + + + align:start position:0% +that I have an R here okay if I didn't +have my problem initially was I didn't + + align:start position:0% +have my problem initially was I didn't + + + align:start position:0% +have my problem initially was I didn't +have an X when I was trying to find an + + align:start position:0% +have an X when I was trying to find an + + + align:start position:0% +have an X when I was trying to find an +anti-derivative but when I do the change + + align:start position:0% +anti-derivative but when I do the change + + + align:start position:0% +anti-derivative but when I do the change +of variables I get an eus R 2 and then + + align:start position:0% +of variables I get an eus R 2 and then + + + align:start position:0% +of variables I get an eus R 2 and then +with an R here that's much easier to + + align:start position:0% +with an R here that's much easier to + + + align:start position:0% +with an R here that's much easier to +find an anti-derivative + + align:start position:0% +find an anti-derivative + + + align:start position:0% +find an anti-derivative +okay so I think that is where I will + + align:start position:0% +okay so I think that is where I will + + + align:start position:0% +okay so I think that is where I will +stop \ No newline at end of file diff --git a/fdbeCmYRVzA.txt b/fdbeCmYRVzA.txt new file mode 100644 index 0000000000000000000000000000000000000000..4b4a9cfc72e5307e2f570edcc7c3b853447d5ebf --- /dev/null +++ b/fdbeCmYRVzA.txt @@ -0,0 +1,1003 @@ +align:start position:0% + +so as an aside for those of you who have + + align:start position:0% +so as an aside for those of you who have + + + align:start position:0% +so as an aside for those of you who have +an + + align:start position:0% +an + + + align:start position:0% +an +understanding of probability theory and + + align:start position:0% +understanding of probability theory and + + + align:start position:0% +understanding of probability theory and +stochastic processes + + align:start position:0% +stochastic processes + + + align:start position:0% +stochastic processes +let me just explain why it is valid to + + align:start position:0% +let me just explain why it is valid to + + + align:start position:0% +let me just explain why it is valid to +bound + + align:start position:0% +bound + + + align:start position:0% +bound +the mean transmission rate in defining + + align:start position:0% +the mean transmission rate in defining + + + align:start position:0% +the mean transmission rate in defining +the indoor reproductive number + + align:start position:0% +the indoor reproductive number + + + align:start position:0% +the indoor reproductive number +when we might be more concerned about + + align:start position:0% +when we might be more concerned about + + + align:start position:0% +when we might be more concerned about +bounding the probability of a + + align:start position:0% +bounding the probability of a + + + align:start position:0% +bounding the probability of a +transmission + + align:start position:0% +transmission + + + align:start position:0% +transmission +so let's let a capital t + + align:start position:0% +so let's let a capital t + + + align:start position:0% +so let's let a capital t +be a random variable which describes the + + align:start position:0% +be a random variable which describes the + + + align:start position:0% +be a random variable which describes the +random + + align:start position:0% +random + + + align:start position:0% +random +number of transmissions that occur in + + align:start position:0% +number of transmissions that occur in + + + align:start position:0% +number of transmissions that occur in +the room + + align:start position:0% + + + + align:start position:0% + +and and this is specifically for the + + align:start position:0% +and and this is specifically for the + + + align:start position:0% +and and this is specifically for the +case + + align:start position:0% +case + + + align:start position:0% +case +for one infector + + align:start position:0% +for one infector + + + align:start position:0% +for one infector +or infected person and + + align:start position:0% +or infected person and + + + align:start position:0% +or infected person and +n minus 1 susceptible + + align:start position:0% + + + + align:start position:0% + +so again the situation of the + + align:start position:0% +so again the situation of the + + + align:start position:0% +so again the situation of the +reproductive number where for every + + align:start position:0% +reproductive number where for every + + + align:start position:0% +reproductive number where for every +person that comes in we want to know is + + align:start position:0% +person that comes in we want to know is + + + align:start position:0% +person that comes in we want to know is +there going to be a transmission and + + align:start position:0% +there going to be a transmission and + + + align:start position:0% +there going to be a transmission and +typically only one affected person would + + align:start position:0% +typically only one affected person would + + + align:start position:0% +typically only one affected person would +be + + align:start position:0% +be + + + align:start position:0% +be +would be seen so this is a random + + align:start position:0% +would be seen so this is a random + + + align:start position:0% +would be seen so this is a random +variable + + align:start position:0% +variable + + + align:start position:0% +variable +and let's let f + + align:start position:0% +and let's let f + + + align:start position:0% +and let's let f +f t of n be the probability density + + align:start position:0% +f t of n be the probability density + + + align:start position:0% +f t of n be the probability density +function + + align:start position:0% +function + + + align:start position:0% +function +that gives the probability of little n + + align:start position:0% +that gives the probability of little n + + + align:start position:0% +that gives the probability of little n +transmissions + + align:start position:0% +transmissions + + + align:start position:0% +transmissions +and then we can define the + + align:start position:0% +and then we can define the + + + align:start position:0% +and then we can define the +risk of a transmission + + align:start position:0% + + + + align:start position:0% + +the risk of at least one transmission + + align:start position:0% + + + + align:start position:0% + +as the probability that this random + + align:start position:0% +as the probability that this random + + + align:start position:0% +as the probability that this random +variable + + align:start position:0% +variable + + + align:start position:0% +variable +takes on a value which is greater than + + align:start position:0% +takes on a value which is greater than + + + align:start position:0% +takes on a value which is greater than +or equal to one + + align:start position:0% +or equal to one + + + align:start position:0% +or equal to one +okay well in terms of the probability + + align:start position:0% +okay well in terms of the probability + + + align:start position:0% +okay well in terms of the probability +density function then + + align:start position:0% +density function then + + + align:start position:0% +density function then +that would be a sum + + align:start position:0% +that would be a sum + + + align:start position:0% +that would be a sum +from one to infinity of the + + align:start position:0% +from one to infinity of the + + + align:start position:0% +from one to infinity of the +uh ft of n basically so + + align:start position:0% +uh ft of n basically so + + + align:start position:0% +uh ft of n basically so +we're just adding the probabilities that + + align:start position:0% +we're just adding the probabilities that + + + align:start position:0% +we're just adding the probabilities that +each we're not uh + + align:start position:0% +each we're not uh + + + align:start position:0% +each we're not uh +seeing a transmission uh to those uh + + align:start position:0% +seeing a transmission uh to those uh + + + align:start position:0% +seeing a transmission uh to those uh +or possibly a transition to those + + align:start position:0% +or possibly a transition to those + + + align:start position:0% +or possibly a transition to those +different numbers of people + + align:start position:0% +different numbers of people + + + align:start position:0% +different numbers of people +now i'd like to do a little calculation + + align:start position:0% +now i'd like to do a little calculation + + + align:start position:0% +now i'd like to do a little calculation +to get an upper bound on this quantity + + align:start position:0% +to get an upper bound on this quantity + + + align:start position:0% +to get an upper bound on this quantity +so we can say that this is less than or + + align:start position:0% +so we can say that this is less than or + + + align:start position:0% +so we can say that this is less than or +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +the sum from n equals 1 to infinity of n + + align:start position:0% +the sum from n equals 1 to infinity of n + + + align:start position:0% +the sum from n equals 1 to infinity of n +f t of n now this + + align:start position:0% +f t of n now this + + + align:start position:0% +f t of n now this +is just a mathematical trick here so n + + align:start position:0% +is just a mathematical trick here so n + + + align:start position:0% +is just a mathematical trick here so n +refers to the natural numbers 1 2 + + align:start position:0% +refers to the natural numbers 1 2 + + + align:start position:0% +refers to the natural numbers 1 2 +3 4 etc those are all positive numbers + + align:start position:0% +3 4 etc those are all positive numbers + + + align:start position:0% +3 4 etc those are all positive numbers +and they're all greater than or equal to + + align:start position:0% +and they're all greater than or equal to + + + align:start position:0% +and they're all greater than or equal to +1. so if i take + + align:start position:0% +1. so if i take + + + align:start position:0% +1. so if i take +1 in this expression over here or + + align:start position:0% +1 in this expression over here or + + + align:start position:0% +1 in this expression over here or +replace it with little n i'm only + + align:start position:0% +replace it with little n i'm only + + + align:start position:0% +replace it with little n i'm only +increasing the value of that sum + + align:start position:0% +increasing the value of that sum + + + align:start position:0% +increasing the value of that sum +because also this ft is a probability + + align:start position:0% +because also this ft is a probability + + + align:start position:0% +because also this ft is a probability +density that has to be positive + + align:start position:0% +density that has to be positive + + + align:start position:0% +density that has to be positive +and then now i can also say that this is + + align:start position:0% +and then now i can also say that this is + + + align:start position:0% +and then now i can also say that this is +actually equal to + + align:start position:0% +actually equal to + + + align:start position:0% +actually equal to +throwing in n equals 0 because that is a + + align:start position:0% +throwing in n equals 0 because that is a + + + align:start position:0% +throwing in n equals 0 because that is a +term that + + align:start position:0% +term that + + + align:start position:0% +term that +is actually identically zero so i can + + align:start position:0% +is actually identically zero so i can + + + align:start position:0% +is actually identically zero so i can +change the summation + + align:start position:0% +change the summation + + + align:start position:0% +change the summation +and then by definition here this thing + + align:start position:0% +and then by definition here this thing + + + align:start position:0% +and then by definition here this thing +is the expected value of the number of + + align:start position:0% +is the expected value of the number of + + + align:start position:0% +is the expected value of the number of +transmissions because i'm + + align:start position:0% +transmissions because i'm + + + align:start position:0% +transmissions because i'm +summing the number of transmissions + + align:start position:0% +summing the number of transmissions + + + align:start position:0% +summing the number of transmissions +little n times the probability of that + + align:start position:0% +little n times the probability of that + + + align:start position:0% +little n times the probability of that +event occurring so that is the + + align:start position:0% +event occurring so that is the + + + align:start position:0% +event occurring so that is the +definition of the average + + align:start position:0% +definition of the average + + + align:start position:0% +definition of the average +so what we're seeing here is that + + align:start position:0% +so what we're seeing here is that + + + align:start position:0% +so what we're seeing here is that +the risk of a transmission + + align:start position:0% +the risk of a transmission + + + align:start position:0% +the risk of a transmission +is rigorously bounded above by the + + align:start position:0% +is rigorously bounded above by the + + + align:start position:0% +is rigorously bounded above by the +expected number of transmissions and so + + align:start position:0% +expected number of transmissions and so + + + align:start position:0% +expected number of transmissions and so +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +if we require that this is less than + + align:start position:0% +if we require that this is less than + + + align:start position:0% +if we require that this is less than +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +our risk tolerance that we've just + + align:start position:0% +our risk tolerance that we've just + + + align:start position:0% +our risk tolerance that we've just +introduced + + align:start position:0% +introduced + + + align:start position:0% +introduced +this is a conservative bound + + align:start position:0% + + + + align:start position:0% + +on the true risk + + align:start position:0% +on the true risk + + + align:start position:0% +on the true risk +which let's say here is defined by rt so + + align:start position:0% +which let's say here is defined by rt so + + + align:start position:0% +which let's say here is defined by rt so +if your goal + + align:start position:0% +if your goal + + + align:start position:0% +if your goal +is to control the probability of having + + align:start position:0% +is to control the probability of having + + + align:start position:0% +is to control the probability of having +at least one transmission so basically + + align:start position:0% +at least one transmission so basically + + + align:start position:0% +at least one transmission so basically +to ensure that no transmissions occur + + align:start position:0% +to ensure that no transmissions occur + + + align:start position:0% +to ensure that no transmissions occur +then you would do well to bound the + + align:start position:0% +then you would do well to bound the + + + align:start position:0% +then you would do well to bound the +expected number of transmissions because + + align:start position:0% +expected number of transmissions because + + + align:start position:0% +expected number of transmissions because +that's an upper bound + + align:start position:0% +that's an upper bound + + + align:start position:0% +that's an upper bound +it can also be shown that as + + align:start position:0% +it can also be shown that as + + + align:start position:0% +it can also be shown that as +epsilon goes to zero so we're talking + + align:start position:0% +epsilon goes to zero so we're talking + + + align:start position:0% +epsilon goes to zero so we're talking +about very low probabilities of + + align:start position:0% +about very low probabilities of + + + align:start position:0% +about very low probabilities of +transmission and often times that is the + + align:start position:0% +transmission and often times that is the + + + align:start position:0% +transmission and often times that is the +case + + align:start position:0% +case + + + align:start position:0% +case +then rt is asymptotically the same + + align:start position:0% +then rt is asymptotically the same + + + align:start position:0% +then rt is asymptotically the same +as the expected number of transmissions + + align:start position:0% +as the expected number of transmissions + + + align:start position:0% +as the expected number of transmissions +so this so this overall risk + + align:start position:0% +so this so this overall risk + + + align:start position:0% +so this so this overall risk +of a transmission and the expected + + align:start position:0% +of a transmission and the expected + + + align:start position:0% +of a transmission and the expected +number are the same + + align:start position:0% +number are the same + + + align:start position:0% +number are the same +and in fact that's one way you can + + align:start position:0% +and in fact that's one way you can + + + align:start position:0% +and in fact that's one way you can +understand sort of even the definition + + align:start position:0% +understand sort of even the definition + + + align:start position:0% +understand sort of even the definition +of + + align:start position:0% +of + + + align:start position:0% +of +of a probability in terms of an expected + + align:start position:0% +of a probability in terms of an expected + + + align:start position:0% +of a probability in terms of an expected +number of events and we are typically + + align:start position:0% +number of events and we are typically + + + align:start position:0% +number of events and we are typically +thinking of cases where epsilon is much + + align:start position:0% +thinking of cases where epsilon is much + + + align:start position:0% +thinking of cases where epsilon is much +less than one + + align:start position:0% +less than one + + + align:start position:0% +less than one +so uh for those of you that have some + + align:start position:0% +so uh for those of you that have some + + + align:start position:0% +so uh for those of you that have some +background and probability you may + + align:start position:0% +background and probability you may + + + align:start position:0% +background and probability you may +recognize that what i've just done here + + align:start position:0% +recognize that what i've just done here + + + align:start position:0% +recognize that what i've just done here +is an example of a much more general + + align:start position:0% +is an example of a much more general + + + align:start position:0% +is an example of a much more general +result which is called markov's + + align:start position:0% +result which is called markov's + + + align:start position:0% +result which is called markov's +inequality + + align:start position:0% + + + + align:start position:0% + +so now we can safely proceed by + + align:start position:0% +so now we can safely proceed by + + + align:start position:0% +so now we can safely proceed by +continuing to work with average values + + align:start position:0% +continuing to work with average values + + + align:start position:0% +continuing to work with average values +of all the quantities of interest + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/fh1bvrJN4Fc.txt b/fh1bvrJN4Fc.txt new file mode 100644 index 0000000000000000000000000000000000000000..80e2d0c0334ba06b3e19318a7923a057b02955bf --- /dev/null +++ b/fh1bvrJN4Fc.txt @@ -0,0 +1,243 @@ +align:start position:0% + +so so I start the class the only way + + align:start position:0% +so so I start the class the only way + + + align:start position:0% +so so I start the class the only way +first day while they are still fresh and + + align:start position:0% +first day while they are still fresh and + + + align:start position:0% +first day while they are still fresh and +unsuspecting of the class contents of my + + align:start position:0% +unsuspecting of the class contents of my + + + align:start position:0% +unsuspecting of the class contents of my +own ideology I give them a survey where + + align:start position:0% +own ideology I give them a survey where + + + align:start position:0% +own ideology I give them a survey where +ask me simple questions you know the + + align:start position:0% +ask me simple questions you know the + + + align:start position:0% +ask me simple questions you know the +major the year but also ask them + + align:start position:0% +major the year but also ask them + + + align:start position:0% +major the year but also ask them +personal questions where were they born + + align:start position:0% +personal questions where were they born + + + align:start position:0% +personal questions where were they born +where they travel during what years they + + align:start position:0% +where they travel during what years they + + + align:start position:0% +where they travel during what years they +were in which parts of the country of + + align:start position:0% +were in which parts of the country of + + + align:start position:0% +were in which parts of the country of +the world and I ask them about some of + + align:start position:0% +the world and I ask them about some of + + + align:start position:0% +the world and I ask them about some of +the course contents you know what do + + align:start position:0% +the course contents you know what do + + + align:start position:0% +the course contents you know what do +they know about cruel languages how they + + align:start position:0% +they know about cruel languages how they + + + align:start position:0% +they know about cruel languages how they +define identity what is the word + + align:start position:0% +define identity what is the word + + + align:start position:0% +define identity what is the word +identity mean what kind of images does + + align:start position:0% +identity mean what kind of images does + + + align:start position:0% +identity mean what kind of images does +the word Caribbean sugar in the mind so + + align:start position:0% +the word Caribbean sugar in the mind so + + + align:start position:0% +the word Caribbean sugar in the mind so +very easy questions to answer but + + align:start position:0% +very easy questions to answer but + + + align:start position:0% +very easy questions to answer but +through these questions what I'm about + + align:start position:0% +through these questions what I'm about + + + align:start position:0% +through these questions what I'm about +to see and go to get a sense of both the + + align:start position:0% +to see and go to get a sense of both the + + + align:start position:0% +to see and go to get a sense of both the +personal background but also what kind + + align:start position:0% +personal background but also what kind + + + align:start position:0% +personal background but also what kind +of what kind of assumptions they bring + + align:start position:0% +of what kind of assumptions they bring + + + align:start position:0% +of what kind of assumptions they bring +to the course and and then I can use + + align:start position:0% +to the course and and then I can use + + + align:start position:0% +to the course and and then I can use +that to kind of have a beginning where I + + align:start position:0% +that to kind of have a beginning where I + + + align:start position:0% +that to kind of have a beginning where I +can address these fundamental assumption + + align:start position:0% +can address these fundamental assumption + + + align:start position:0% +can address these fundamental assumption +that we do bring in the course and also + + align:start position:0% +that we do bring in the course and also + + + align:start position:0% +that we do bring in the course and also +to connect the discussion to the + + align:start position:0% +to connect the discussion to the + + + align:start position:0% +to connect the discussion to the +personal profiles and then that and then + + align:start position:0% +personal profiles and then that and then + + + align:start position:0% +personal profiles and then that and then +as we progress I can from time to time + + align:start position:0% +as we progress I can from time to time + + + align:start position:0% +as we progress I can from time to time +check to see how some of the ideas might + + align:start position:0% +check to see how some of the ideas might + + + align:start position:0% +check to see how some of the ideas might +have mutated merav evolve through our + + align:start position:0% +have mutated merav evolve through our + + + align:start position:0% +have mutated merav evolve through our +discussions so it's a nice benchmark to + + align:start position:0% +discussions so it's a nice benchmark to + + + align:start position:0% +discussions so it's a nice benchmark to +start with \ No newline at end of file diff --git a/fuo2j6f8yok.txt b/fuo2j6f8yok.txt new file mode 100644 index 0000000000000000000000000000000000000000..12a6e5996455fc617e45152edd933ba04e541b2a --- /dev/null +++ b/fuo2j6f8yok.txt @@ -0,0 +1,883 @@ +align:start position:0% + +okay why does this matter well this is + + align:start position:0% +okay why does this matter well this is + + + align:start position:0% +okay why does this matter well this is +one reason + + align:start position:0% +one reason + + + align:start position:0% +one reason +if you don't plan your cold work + + align:start position:0% +if you don't plan your cold work + + + align:start position:0% +if you don't plan your cold work +carefully + + align:start position:0% +carefully + + + align:start position:0% +carefully +you might make the material too brittle + + align:start position:0% +you might make the material too brittle + + + align:start position:0% +you might make the material too brittle +you wanted it to be so hard because this + + align:start position:0% +you wanted it to be so hard because this + + + align:start position:0% +you wanted it to be so hard because this +was such an important ship + + align:start position:0% +was such an important ship + + + align:start position:0% +was such an important ship +and it was going to be a big deal and + + align:start position:0% +and it was going to be a big deal and + + + align:start position:0% +and it was going to be a big deal and +the launch was really exciting and then + + align:start position:0% +the launch was really exciting and then + + + align:start position:0% +the launch was really exciting and then +it cracks in half + + align:start position:0% +it cracks in half + + + align:start position:0% +it cracks in half +the entire ship why because you didn't + + align:start position:0% +the entire ship why because you didn't + + + align:start position:0% +the entire ship why because you didn't +look up + + align:start position:0% +look up + + + align:start position:0% +look up +what dislocations mean you didn't take + + align:start position:0% +what dislocations mean you didn't take + + + align:start position:0% +what dislocations mean you didn't take +309 one + + align:start position:0% +309 one + + + align:start position:0% +309 one +that's why that's a pretty big crack + + align:start position:0% +that's why that's a pretty big crack + + + align:start position:0% +that's why that's a pretty big crack +but the the main why this matters oh i + + align:start position:0% +but the the main why this matters oh i + + + align:start position:0% +but the the main why this matters oh i +couldn't help it + + align:start position:0% +couldn't help it + + + align:start position:0% +couldn't help it +i am a big fan of wind wind energy is + + align:start position:0% +i am a big fan of wind wind energy is + + + align:start position:0% +i am a big fan of wind wind energy is +growing and growing and it's it's + + align:start position:0% +growing and growing and it's it's + + + align:start position:0% +growing and growing and it's it's +it's such a great resource it's such a + + align:start position:0% +it's such a great resource it's such a + + + align:start position:0% +it's such a great resource it's such a +great national resource + + align:start position:0% +great national resource + + + align:start position:0% +great national resource +here's the global uh capacity and + + align:start position:0% +here's the global uh capacity and + + + align:start position:0% +here's the global uh capacity and +this is install capacity for wind + + align:start position:0% +this is install capacity for wind + + + align:start position:0% +this is install capacity for wind +turbines + + align:start position:0% +turbines + + + align:start position:0% +turbines +um but see this is a mechanical + + align:start position:0% +um but see this is a mechanical + + + align:start position:0% +um but see this is a mechanical +materials problem that you are now + + align:start position:0% +materials problem that you are now + + + align:start position:0% +materials problem that you are now +equipped to think about more deeply + + align:start position:0% +equipped to think about more deeply + + + align:start position:0% +equipped to think about more deeply +right um because you see you can + + align:start position:0% +right um because you see you can + + + align:start position:0% +right um because you see you can +you can do a lot of different + + align:start position:0% +you can do a lot of different + + + align:start position:0% +you can do a lot of different +experiments on those turbines so the + + align:start position:0% +experiments on those turbines so the + + + align:start position:0% +experiments on those turbines so the +turbine + + align:start position:0% +turbine + + + align:start position:0% +turbine +so the blades here are critical you can + + align:start position:0% +so the blades here are critical you can + + + align:start position:0% +so the blades here are critical you can +imagine that + + align:start position:0% +imagine that + + + align:start position:0% +imagine that +you want them to be light but but if + + align:start position:0% +you want them to be light but but if + + + align:start position:0% +you want them to be light but but if +they're too light there may not be + + align:start position:0% +they're too light there may not be + + + align:start position:0% +they're too light there may not be +strong enough and then how do they need + + align:start position:0% +strong enough and then how do they need + + + align:start position:0% +strong enough and then how do they need +to be strong because you've got + + align:start position:0% +to be strong because you've got + + + align:start position:0% +to be strong because you've got +huge amounts of wind coming at them + + align:start position:0% +huge amounts of wind coming at them + + + align:start position:0% +huge amounts of wind coming at them +and it turns out you need to hit just + + align:start position:0% +and it turns out you need to hit just + + + align:start position:0% +and it turns out you need to hit just +the right balance + + align:start position:0% +the right balance + + + align:start position:0% +the right balance +of elastic deformation + + align:start position:0% +of elastic deformation + + + align:start position:0% +of elastic deformation +before it goes into some plastic regime + + align:start position:0% +before it goes into some plastic regime + + + align:start position:0% +before it goes into some plastic regime +you need to hit just the right balance + + align:start position:0% +you need to hit just the right balance + + + align:start position:0% +you need to hit just the right balance +of ductility + + align:start position:0% +of ductility + + + align:start position:0% +of ductility +so here's for example uh these are some + + align:start position:0% +so here's for example uh these are some + + + align:start position:0% +so here's for example uh these are some +simulations here are some experiments on + + align:start position:0% +simulations here are some experiments on + + + align:start position:0% +simulations here are some experiments on +a new + + align:start position:0% +a new + + + align:start position:0% +a new +material for a wind turbine blade and + + align:start position:0% +material for a wind turbine blade and + + + align:start position:0% +material for a wind turbine blade and +then you put it out there + + align:start position:0% +then you put it out there + + + align:start position:0% +then you put it out there +and and look at what happens ice by the + + align:start position:0% +and and look at what happens ice by the + + + align:start position:0% +and and look at what happens ice by the +way this ice + + align:start position:0% +way this ice + + + align:start position:0% +way this ice +comes off at hundreds of miles an hour + + align:start position:0% +comes off at hundreds of miles an hour + + + align:start position:0% +comes off at hundreds of miles an hour +in chunks + + align:start position:0% +in chunks + + + align:start position:0% +in chunks +these farmers are not happy about that + + align:start position:0% +these farmers are not happy about that + + + align:start position:0% +these farmers are not happy about that +seriously but those are bugs + + align:start position:0% +seriously but those are bugs + + + align:start position:0% +seriously but those are bugs +those are bugs so actually bugs in + + align:start position:0% +those are bugs so actually bugs in + + + align:start position:0% +those are bugs so actually bugs in +wind turbine blades is a serious problem + + align:start position:0% +wind turbine blades is a serious problem + + + align:start position:0% +wind turbine blades is a serious problem +how do you clean + + align:start position:0% +how do you clean + + + align:start position:0% +how do you clean +bugs off of it because it dramatically + + align:start position:0% +bugs off of it because it dramatically + + + align:start position:0% +bugs off of it because it dramatically +changes the aerodynamics and the + + align:start position:0% +changes the aerodynamics and the + + + align:start position:0% +changes the aerodynamics and the +efficiency + + align:start position:0% +efficiency + + + align:start position:0% +efficiency +it also can damage the blade itself + + align:start position:0% +it also can damage the blade itself + + + align:start position:0% +it also can damage the blade itself +so there's all sorts of work going on + + align:start position:0% +so there's all sorts of work going on + + + align:start position:0% +so there's all sorts of work going on +how do you make bug proof + + align:start position:0% +how do you make bug proof + + + align:start position:0% +how do you make bug proof +wind turbine blades okay well now just + + align:start position:0% +wind turbine blades okay well now just + + + align:start position:0% +wind turbine blades okay well now just +spray it with something ah but then does + + align:start position:0% +spray it with something ah but then does + + + align:start position:0% +spray it with something ah but then does +it have the right + + align:start position:0% +it have the right + + + align:start position:0% +it have the right +plastic different what does it have the + + align:start position:0% +plastic different what does it have the + + + align:start position:0% +plastic different what does it have the +right yield point or is it just going to + + align:start position:0% +right yield point or is it just going to + + + align:start position:0% +right yield point or is it just going to +crack + + align:start position:0% +crack + + + align:start position:0% +crack +right and by the way it's got to have uh + + align:start position:0% +right and by the way it's got to have uh + + + align:start position:0% +right and by the way it's got to have uh +five times ten to the ninth cycles + + align:start position:0% +five times ten to the ninth cycles + + + align:start position:0% +five times ten to the ninth cycles +before it can fail + + align:start position:0% +before it can fail + + + align:start position:0% +before it can fail +that's like the metric so that's a + + align:start position:0% +that's like the metric so that's a + + + align:start position:0% +that's like the metric so that's a +pretty big ask of a material + + align:start position:0% +pretty big ask of a material + + + align:start position:0% +pretty big ask of a material +it all comes down to understanding this + + align:start position:0% +it all comes down to understanding this + + + align:start position:0% +it all comes down to understanding this +curve + + align:start position:0% +curve + + + align:start position:0% +curve +and and in the broader sense of + + align:start position:0% +and and in the broader sense of + + + align:start position:0% +and and in the broader sense of +materials + + align:start position:0% +materials + + + align:start position:0% +materials +this to me is a very exciting ask + + align:start position:0% +this to me is a very exciting ask + + + align:start position:0% +this to me is a very exciting ask +why because if you look at a plot + + align:start position:0% +why because if you look at a plot + + + align:start position:0% +why because if you look at a plot +of the density of materials okay heavy + + align:start position:0% +of the density of materials okay heavy + + + align:start position:0% +of the density of materials okay heavy +light good kilograms per meter cubed and + + align:start position:0% +light good kilograms per meter cubed and + + + align:start position:0% +light good kilograms per meter cubed and +and the young's modulus now this is a + + align:start position:0% +and the young's modulus now this is a + + + align:start position:0% +and the young's modulus now this is a +measure of + + align:start position:0% +measure of + + + align:start position:0% +measure of +of the strength of the material right + + align:start position:0% +of the strength of the material right + + + align:start position:0% +of the strength of the material right +it's a measure of how much + + align:start position:0% +it's a measure of how much + + + align:start position:0% +it's a measure of how much +strain you could put on the material + + align:start position:0% +strain you could put on the material + + + align:start position:0% +strain you could put on the material +before it breaks or + + align:start position:0% +before it breaks or + + + align:start position:0% +before it breaks or +it goes through deformation but look at + + align:start position:0% +it goes through deformation but look at + + + align:start position:0% +it goes through deformation but look at +this different materials are here + + align:start position:0% +this different materials are here + + + align:start position:0% +this different materials are here +rubbers foams okay foams have + + align:start position:0% +rubbers foams okay foams have + + + align:start position:0% +rubbers foams okay foams have +relatively low young's modulus but + + align:start position:0% +relatively low young's modulus but + + + align:start position:0% +relatively low young's modulus but +they're really light that could be good + + align:start position:0% +they're really light that could be good + + + align:start position:0% +they're really light that could be good +up here you've got metals and alloys + + align:start position:0% +up here you've got metals and alloys + + + align:start position:0% +up here you've got metals and alloys +ceramics + + align:start position:0% +ceramics + + + align:start position:0% +ceramics +you've got polymers in here but but + + align:start position:0% +you've got polymers in here but but + + + align:start position:0% +you've got polymers in here but but +notice + + align:start position:0% +notice + + + align:start position:0% +notice +i've got so many different applications + + align:start position:0% +i've got so many different applications + + + align:start position:0% +i've got so many different applications +and needs in the applications + + align:start position:0% +and needs in the applications + + + align:start position:0% +and needs in the applications +and i've got this plot where i've got + + align:start position:0% +and i've got this plot where i've got + + + align:start position:0% +and i've got this plot where i've got +nothing here and nothing + + align:start position:0% +nothing here and nothing + + + align:start position:0% +nothing here and nothing +here even though if i could fill this + + align:start position:0% +here even though if i could fill this + + + align:start position:0% +here even though if i could fill this +out + + align:start position:0% +out + + + align:start position:0% +out +and dial up any stress strain curve + + align:start position:0% +and dial up any stress strain curve + + + align:start position:0% +and dial up any stress strain curve +for any density or young's modulus you + + align:start position:0% +for any density or young's modulus you + + + align:start position:0% +for any density or young's modulus you +can make a big difference in a lot of + + align:start position:0% +can make a big difference in a lot of + + + align:start position:0% +can make a big difference in a lot of +different applications + + align:start position:0% +different applications + + + align:start position:0% +different applications +so i think this is a great a great + + align:start position:0% + + + + align:start position:0% + +challenge + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/gQ1YPzcHZqo.txt b/gQ1YPzcHZqo.txt new file mode 100644 index 0000000000000000000000000000000000000000..44b0c1883912a8978538de35163a2969d055b439 --- /dev/null +++ b/gQ1YPzcHZqo.txt @@ -0,0 +1,14099 @@ +align:start position:0% + +so what we'll do today is really um + + align:start position:0% +so what we'll do today is really um + + + align:start position:0% +so what we'll do today is really um +switching to sort of the computational + + align:start position:0% +switching to sort of the computational + + + align:start position:0% +switching to sort of the computational +description and characterization of + + align:start position:0% +description and characterization of + + + align:start position:0% +description and characterization of +thermodynamical properties uh as we have + + align:start position:0% +thermodynamical properties uh as we have + + + align:start position:0% +thermodynamical properties uh as we have +seen sort of in a lot of the previous + + align:start position:0% +seen sort of in a lot of the previous + + + align:start position:0% +seen sort of in a lot of the previous +lectures we have been focusing on + + align:start position:0% +lectures we have been focusing on + + + align:start position:0% +lectures we have been focusing on +finding out good energy models that is + + align:start position:0% +finding out good energy models that is + + + align:start position:0% +finding out good energy models that is +being able to calculate what is the + + align:start position:0% +being able to calculate what is the + + + align:start position:0% +being able to calculate what is the +energy of a system giving the coordinate + + align:start position:0% +energy of a system giving the coordinate + + + align:start position:0% +energy of a system giving the coordinate +of its ions and now what we want to + + align:start position:0% +of its ions and now what we want to + + + align:start position:0% +of its ions and now what we want to +understand really is what is the + + align:start position:0% +understand really is what is the + + + align:start position:0% +understand really is what is the +evolution of this system in the the + + align:start position:0% +evolution of this system in the the + + + align:start position:0% +evolution of this system in the the +presence of a fin at temperature + + align:start position:0% +presence of a fin at temperature + + + align:start position:0% +presence of a fin at temperature +temperature really means that there is + + align:start position:0% +temperature really means that there is + + + align:start position:0% +temperature really means that there is +an average kinetic energy available for + + align:start position:0% +an average kinetic energy available for + + + align:start position:0% +an average kinetic energy available for +all the atoms and the molecules in your + + align:start position:0% +all the atoms and the molecules in your + + + align:start position:0% +all the atoms and the molecules in your +system that means that there is really a + + align:start position:0% +system that means that there is really a + + + align:start position:0% +system that means that there is really a +microscopic Dynamics and we want to + + align:start position:0% +microscopic Dynamics and we want to + + + align:start position:0% +microscopic Dynamics and we want to +follow that uh one of the most important + + align:start position:0% +follow that uh one of the most important + + + align:start position:0% +follow that uh one of the most important +things and this sort of goes back to + + align:start position:0% +things and this sort of goes back to + + + align:start position:0% +things and this sort of goes back to +really the first lecture that you have + + align:start position:0% +really the first lecture that you have + + + align:start position:0% +really the first lecture that you have +seen in this sort of class for the + + align:start position:0% +seen in this sort of class for the + + + align:start position:0% +seen in this sort of class for the +quantum part is that there is the sort + + align:start position:0% +quantum part is that there is the sort + + + align:start position:0% +quantum part is that there is the sort +of fundamental de BR relation uh that + + align:start position:0% +of fundamental de BR relation uh that + + + align:start position:0% +of fundamental de BR relation uh that +sort of gives us an estimate of what is + + align:start position:0% +sort of gives us an estimate of what is + + + align:start position:0% +sort of gives us an estimate of what is +the Quantum wavelength of any kind of + + align:start position:0% +the Quantum wavelength of any kind of + + + align:start position:0% +the Quantum wavelength of any kind of +object remember we said that sort of the + + align:start position:0% +object remember we said that sort of the + + + align:start position:0% +object remember we said that sort of the +wavelength times the momentum should + + align:start position:0% +wavelength times the momentum should + + + align:start position:0% +wavelength times the momentum should +sort of be equal to the plank constant + + align:start position:0% +sort of be equal to the plank constant + + + align:start position:0% +sort of be equal to the plank constant +and that really means that for an object + + align:start position:0% +and that really means that for an object + + + align:start position:0% +and that really means that for an object +like an electron the de wavelength that + + align:start position:0% +like an electron the de wavelength that + + + align:start position:0% +like an electron the de wavelength that +comes out from that relation is + + align:start position:0% +comes out from that relation is + + + align:start position:0% +comes out from that relation is +comparable to the distance between the + + align:start position:0% +comparable to the distance between the + + + align:start position:0% +comparable to the distance between the +atoms so if the wavelength of an + + align:start position:0% +atoms so if the wavelength of an + + + align:start position:0% +atoms so if the wavelength of an +electron is of the order of the anstrom + + align:start position:0% +electron is of the order of the anstrom + + + align:start position:0% +electron is of the order of the anstrom +10 Theus 10 m it means means that the + + align:start position:0% +10 Theus 10 m it means means that the + + + align:start position:0% +10 Theus 10 m it means means that the +wav like properties of the electrons + + align:start position:0% +wav like properties of the electrons + + + align:start position:0% +wav like properties of the electrons +needs to be studied and the electron + + align:start position:0% +needs to be studied and the electron + + + align:start position:0% +needs to be studied and the electron +will be behave as a wave and that's why + + align:start position:0% +will be behave as a wave and that's why + + + align:start position:0% +will be behave as a wave and that's why +we sort of use the shedding equation to + + align:start position:0% +we sort of use the shedding equation to + + + align:start position:0% +we sort of use the shedding equation to +describe electrons um the wavelength of + + align:start position:0% +describe electrons um the wavelength of + + + align:start position:0% +describe electrons um the wavelength of +the nucle is much much smaller that + + align:start position:0% +the nucle is much much smaller that + + + align:start position:0% +the nucle is much much smaller that +means that nuclei really didn't we don't + + align:start position:0% +means that nuclei really didn't we don't + + + align:start position:0% +means that nuclei really didn't we don't +really need to sort of take into account + + align:start position:0% +really need to sort of take into account + + + align:start position:0% +really need to sort of take into account +to a good approximation the quantum + + align:start position:0% +to a good approximation the quantum + + + align:start position:0% +to a good approximation the quantum +nature of the nuclei their wavelength is + + align:start position:0% +nature of the nuclei their wavelength is + + + align:start position:0% +nature of the nuclei their wavelength is +so small that they can be treated U + + align:start position:0% +so small that they can be treated U + + + align:start position:0% +so small that they can be treated U +practically correctly as classical + + align:start position:0% +practically correctly as classical + + + align:start position:0% +practically correctly as classical +particles and that's why actually nuclei + + align:start position:0% +particles and that's why actually nuclei + + + align:start position:0% +particles and that's why actually nuclei +in a way still follow the rules of + + align:start position:0% +in a way still follow the rules of + + + align:start position:0% +in a way still follow the rules of +classical dynamics that is they evolve + + align:start position:0% +classical dynamics that is they evolve + + + align:start position:0% +classical dynamics that is they evolve +in time following Newton equation of + + align:start position:0% +in time following Newton equation of + + + align:start position:0% +in time following Newton equation of +motion again this is an approximation + + align:start position:0% +motion again this is an approximation + + + align:start position:0% +motion again this is an approximation +that involves treating the nuclear as + + align:start position:0% +that involves treating the nuclear as + + + align:start position:0% +that involves treating the nuclear as +classical particles and not as Quantum + + align:start position:0% +classical particles and not as Quantum + + + align:start position:0% +classical particles and not as Quantum +particles but especially at high + + align:start position:0% +particles but especially at high + + + align:start position:0% +particles but especially at high +temperature this is a very good + + align:start position:0% +temperature this is a very good + + + align:start position:0% +temperature this is a very good +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +and so a lot of uh approaches in + + align:start position:0% +and so a lot of uh approaches in + + + align:start position:0% +and so a lot of uh approaches in +computational Material Science have to + + align:start position:0% +computational Material Science have to + + + align:start position:0% +computational Material Science have to +do with solving a Newton equation of + + align:start position:0% +do with solving a Newton equation of + + + align:start position:0% +do with solving a Newton equation of +motions for a system of interacting + + align:start position:0% +motions for a system of interacting + + + align:start position:0% +motions for a system of interacting +nuclei and evolving those nucle in time + + align:start position:0% +nuclei and evolving those nucle in time + + + align:start position:0% +nuclei and evolving those nucle in time +to study the thermodynamical properties + + align:start position:0% +to study the thermodynamical properties + + + align:start position:0% +to study the thermodynamical properties +of the system and so that's why I + + align:start position:0% +of the system and so that's why I + + + align:start position:0% +of the system and so that's why I +actually sort of started with a reminder + + align:start position:0% +actually sort of started with a reminder + + + align:start position:0% +actually sort of started with a reminder +of Newton equation of motion that is + + align:start position:0% +of Newton equation of motion that is + + + align:start position:0% +of Newton equation of motion that is +really a Ordinary second order + + align:start position:0% +really a Ordinary second order + + + align:start position:0% +really a Ordinary second order +differential equation that is when you + + align:start position:0% +differential equation that is when you + + + align:start position:0% +differential equation that is when you +have a particle of mass m in a force + + align:start position:0% +have a particle of mass m in a force + + + align:start position:0% +have a particle of mass m in a force +field that is this F ofr Well we can + + align:start position:0% +field that is this F ofr Well we can + + + align:start position:0% +field that is this F ofr Well we can +calculate its trajectory that is its + + align:start position:0% +calculate its trajectory that is its + + + align:start position:0% +calculate its trajectory that is its +position as a function of time and its + + align:start position:0% +position as a function of time and its + + + align:start position:0% +position as a function of time and its +velocity as a function of time uh by + + align:start position:0% +velocity as a function of time uh by + + + align:start position:0% +velocity as a function of time uh by +integrating this differential equation + + align:start position:0% +integrating this differential equation + + + align:start position:0% +integrating this differential equation +and you know sort of the classical case + + align:start position:0% +and you know sort of the classical case + + + align:start position:0% +and you know sort of the classical case +that sort of you know is always + + align:start position:0% +that sort of you know is always + + + align:start position:0% +that sort of you know is always +presented say is the evolution of a + + align:start position:0% +presented say is the evolution of a + + + align:start position:0% +presented say is the evolution of a +particle say in a constant force field + + align:start position:0% +particle say in a constant force field + + + align:start position:0% +particle say in a constant force field +like a particle you know under the + + align:start position:0% +like a particle you know under the + + + align:start position:0% +like a particle you know under the +gravitational law that's of to a large + + align:start position:0% +gravitational law that's of to a large + + + align:start position:0% +gravitational law that's of to a large +extent is constant if you don't move + + align:start position:0% +extent is constant if you don't move + + + align:start position:0% +extent is constant if you don't move +very much and because in that case the + + align:start position:0% +very much and because in that case the + + + align:start position:0% +very much and because in that case the +force is really a constant the + + align:start position:0% +force is really a constant the + + + align:start position:0% +force is really a constant the +integration of this becomes trivial it's + + align:start position:0% +integration of this becomes trivial it's + + + align:start position:0% +integration of this becomes trivial it's +really a sort of you know second + + align:start position:0% +really a sort of you know second + + + align:start position:0% +really a sort of you know second +derivative that needs to be equal a + + align:start position:0% +derivative that needs to be equal a + + + align:start position:0% +derivative that needs to be equal a +constant and integrating that gives us a + + align:start position:0% +constant and integrating that gives us a + + + align:start position:0% +constant and integrating that gives us a +parabola but the reason why I'm sort of + + align:start position:0% +parabola but the reason why I'm sort of + + + align:start position:0% +parabola but the reason why I'm sort of +you know focusing on this is to sort of + + align:start position:0% +you know focusing on this is to sort of + + + align:start position:0% +you know focusing on this is to sort of +remind you of the initial conditions in + + align:start position:0% +remind you of the initial conditions in + + + align:start position:0% +remind you of the initial conditions in +a differential equations that is if we + + align:start position:0% +a differential equations that is if we + + + align:start position:0% +a differential equations that is if we +have a second order differential + + align:start position:0% +have a second order differential + + + align:start position:0% +have a second order differential +equation um the general solution let's + + align:start position:0% +equation um the general solution let's + + + align:start position:0% +equation um the general solution let's +say in this case for this force field + + align:start position:0% +say in this case for this force field + + + align:start position:0% +say in this case for this force field +would be a parabola is uniquely + + align:start position:0% +would be a parabola is uniquely + + + align:start position:0% +would be a parabola is uniquely +identified once we specify the position + + align:start position:0% +identified once we specify the position + + + align:start position:0% +identified once we specify the position +at a certain instant and the velocity as + + align:start position:0% +at a certain instant and the velocity as + + + align:start position:0% +at a certain instant and the velocity as +a certain instant that is among all the + + align:start position:0% +a certain instant that is among all the + + + align:start position:0% +a certain instant that is among all the +possible parabolas in the world you + + align:start position:0% +possible parabolas in the world you + + + align:start position:0% +possible parabolas in the world you +select the one that your projectile is + + align:start position:0% +select the one that your projectile is + + + align:start position:0% +select the one that your projectile is +going to follow once you have the + + align:start position:0% +going to follow once you have the + + + align:start position:0% +going to follow once you have the +position and the velocity at a certain + + align:start position:0% +position and the velocity at a certain + + + align:start position:0% +position and the velocity at a certain +instant and that's why actually Dynamics + + align:start position:0% +instant and that's why actually Dynamics + + + align:start position:0% +instant and that's why actually Dynamics +and molecular Dynamics and a lot of + + align:start position:0% +and molecular Dynamics and a lot of + + + align:start position:0% +and molecular Dynamics and a lot of +physical properties basically depend + + align:start position:0% +physical properties basically depend + + + align:start position:0% +physical properties basically depend +essentially on the position of the + + align:start position:0% +essentially on the position of the + + + align:start position:0% +essentially on the position of the +particle in your system and the Velocity + + align:start position:0% +particle in your system and the Velocity + + + align:start position:0% +particle in your system and the Velocity +in the of the particle in your system + + align:start position:0% +in the of the particle in your system + + + align:start position:0% +in the of the particle in your system +that's why there is sort of you know no + + align:start position:0% +that's why there is sort of you know no + + + align:start position:0% +that's why there is sort of you know no +physical observable that depends say on + + align:start position:0% +physical observable that depends say on + + + align:start position:0% +physical observable that depends say on +the fifth derivative with respect to + + align:start position:0% +the fifth derivative with respect to + + + align:start position:0% +the fifth derivative with respect to +time it's really because the Dynamics of + + align:start position:0% +time it's really because the Dynamics of + + + align:start position:0% +time it's really because the Dynamics of +that system follows Newton's equation of + + align:start position:0% +that system follows Newton's equation of + + + align:start position:0% +that system follows Newton's equation of +motion okay with this what we really + + align:start position:0% +motion okay with this what we really + + + align:start position:0% +motion okay with this what we really +need to deal in general is with you know + + align:start position:0% +need to deal in general is with you know + + + align:start position:0% +need to deal in general is with you know +a system of interacting particles and + + align:start position:0% +a system of interacting particles and + + + align:start position:0% +a system of interacting particles and +you know for a moment you could actually + + align:start position:0% +you know for a moment you could actually + + + align:start position:0% +you know for a moment you could actually +think that you know this uh I + + align:start position:0% +think that you know this uh I + + + align:start position:0% +think that you know this uh I +interacting particles could be the + + align:start position:0% +interacting particles could be the + + + align:start position:0% +interacting particles could be the +planets orbiting around the Sun so each + + align:start position:0% +planets orbiting around the Sun so each + + + align:start position:0% +planets orbiting around the Sun so each +of the planet I will have its own + + align:start position:0% +of the planet I will have its own + + + align:start position:0% +of the planet I will have its own +trajectory R oft will have its own mass + + align:start position:0% +trajectory R oft will have its own mass + + + align:start position:0% +trajectory R oft will have its own mass +and they all live in a force field + + align:start position:0% +and they all live in a force field + + + align:start position:0% +and they all live in a force field +that's really where the many body + + align:start position:0% +that's really where the many body + + + align:start position:0% +that's really where the many body +complexity again comes out it's a many + + align:start position:0% +complexity again comes out it's a many + + + align:start position:0% +complexity again comes out it's a many +body complexity that is much easier to + + align:start position:0% +body complexity that is much easier to + + + align:start position:0% +body complexity that is much easier to +deal with than the many body complex of + + align:start position:0% +deal with than the many body complex of + + + align:start position:0% +deal with than the many body complex of +the electron problem because again now + + align:start position:0% +the electron problem because again now + + + align:start position:0% +the electron problem because again now +we describe each object just with a set + + align:start position:0% +we describe each object just with a set + + + align:start position:0% +we describe each object just with a set +of six variables it's three space + + align:start position:0% +of six variables it's three space + + + align:start position:0% +of six variables it's three space +coordinate and it's three momentum + + align:start position:0% +coordinate and it's three momentum + + + align:start position:0% +coordinate and it's three momentum +coordinate but still each and every + + align:start position:0% +coordinate but still each and every + + + align:start position:0% +coordinate but still each and every +object interact with each other when you + + align:start position:0% +object interact with each other when you + + + align:start position:0% +object interact with each other when you +look at the planets orbiting around the + + align:start position:0% +look at the planets orbiting around the + + + align:start position:0% +look at the planets orbiting around the +Sun you sort of you know to First + + align:start position:0% +Sun you sort of you know to First + + + align:start position:0% +Sun you sort of you know to First +approximation could only consider the + + align:start position:0% +approximation could only consider the + + + align:start position:0% +approximation could only consider the +gravitational attraction to the Sun but + + align:start position:0% +gravitational attraction to the Sun but + + + align:start position:0% +gravitational attraction to the Sun but +in reality also the planets interact + + align:start position:0% +in reality also the planets interact + + + align:start position:0% +in reality also the planets interact +with each other and so again even if + + align:start position:0% +with each other and so again even if + + + align:start position:0% +with each other and so again even if +sort of you know this is much simpler + + align:start position:0% +sort of you know this is much simpler + + + align:start position:0% +sort of you know this is much simpler +than the shadinger equation as soon as + + align:start position:0% +than the shadinger equation as soon as + + + align:start position:0% +than the shadinger equation as soon as +you start have more than two body + + align:start position:0% +you start have more than two body + + + align:start position:0% +you start have more than two body +interacting it really becomes too + + align:start position:0% +interacting it really becomes too + + + align:start position:0% +interacting it really becomes too +complex to solve analytically and so all + + align:start position:0% +complex to solve analytically and so all + + + align:start position:0% +complex to solve analytically and so all +the molecular Dynamic techniques have as + + align:start position:0% +the molecular Dynamic techniques have as + + + align:start position:0% +the molecular Dynamic techniques have as +their only object basically the + + align:start position:0% +their only object basically the + + + align:start position:0% +their only object basically the +integration in time of this equation of + + align:start position:0% +integration in time of this equation of + + + align:start position:0% +integration in time of this equation of +motion in an efficient in an efficient + + align:start position:0% +motion in an efficient in an efficient + + + align:start position:0% +motion in an efficient in an efficient +form uh there are sort of a couple of + + align:start position:0% +form uh there are sort of a couple of + + + align:start position:0% +form uh there are sort of a couple of +comments that sort of one wants to make + + align:start position:0% + + + + align:start position:0% + +uh in general we deal with a + + align:start position:0% +uh in general we deal with a + + + align:start position:0% +uh in general we deal with a +conservative fields that is uh the force + + align:start position:0% +conservative fields that is uh the force + + + align:start position:0% +conservative fields that is uh the force +depends on position only that also means + + align:start position:0% +depends on position only that also means + + + align:start position:0% +depends on position only that also means +that the work that you making going from + + align:start position:0% +that the work that you making going from + + + align:start position:0% +that the work that you making going from +one point to another point the integral + + align:start position:0% +one point to another point the integral + + + align:start position:0% +one point to another point the integral +of the force times um the displacement + + align:start position:0% +of the force times um the displacement + + + align:start position:0% +of the force times um the displacement +is going to be independent from the + + align:start position:0% +is going to be independent from the + + + align:start position:0% +is going to be independent from the +trajectory so the energy if you want is + + align:start position:0% +trajectory so the energy if you want is + + + align:start position:0% +trajectory so the energy if you want is +just a function of the position uh the + + align:start position:0% +just a function of the position uh the + + + align:start position:0% +just a function of the position uh the +other thing that sort of descends + + align:start position:0% +other thing that sort of descends + + + align:start position:0% +other thing that sort of descends +immediately + + align:start position:0% +immediately + + + align:start position:0% +immediately +from this equation of motion is that the + + align:start position:0% +from this equation of motion is that the + + + align:start position:0% +from this equation of motion is that the +total energy of the system is conserved + + align:start position:0% +total energy of the system is conserved + + + align:start position:0% +total energy of the system is conserved +and that's easy very easy to prove and + + align:start position:0% +and that's easy very easy to prove and + + + align:start position:0% +and that's easy very easy to prove and +I'll do it in a moment and that's what's + + align:start position:0% +I'll do it in a moment and that's what's + + + align:start position:0% +I'll do it in a moment and that's what's +often called a microcanonical Evolution + + align:start position:0% +often called a microcanonical Evolution + + + align:start position:0% +often called a microcanonical Evolution +when you sort of read about + + align:start position:0% +when you sort of read about + + + align:start position:0% +when you sort of read about +microcanonical ensembles uh it means + + align:start position:0% +microcanonical ensembles uh it means + + + align:start position:0% +microcanonical ensembles uh it means +that you're actually under the condition + + align:start position:0% +that you're actually under the condition + + + align:start position:0% +that you're actually under the condition +in which the total energy of your system + + align:start position:0% +in which the total energy of your system + + + align:start position:0% +in which the total energy of your system +is conserved and again what is the total + + align:start position:0% +is conserved and again what is the total + + + align:start position:0% +is conserved and again what is the total +energy of your system well if you have + + align:start position:0% +energy of your system well if you have + + + align:start position:0% +energy of your system well if you have +one particle is just trivially the + + align:start position:0% +one particle is just trivially the + + + align:start position:0% +one particle is just trivially the +kinetic energy 12 M + + align:start position:0% +kinetic energy 12 M + + + align:start position:0% +kinetic energy 12 M +v² plus the potential + + align:start position:0% +v² plus the potential + + + align:start position:0% +v² plus the potential +energy V of R of that particle I'm just + + align:start position:0% +energy V of R of that particle I'm just + + + align:start position:0% +energy V of R of that particle I'm just +doing everything in one dimension and + + align:start position:0% +doing everything in one dimension and + + + align:start position:0% +doing everything in one dimension and +you ask why is this going to be + + align:start position:0% +you ask why is this going to be + + + align:start position:0% +you ask why is this going to be +conserved well you can just prove it by + + align:start position:0% +conserved well you can just prove it by + + + align:start position:0% +conserved well you can just prove it by +taking the time derivative of this + + align:start position:0% +taking the time derivative of this + + + align:start position:0% +taking the time derivative of this +quantity okay so we have taken kinetic + + align:start position:0% +quantity okay so we have taken kinetic + + + align:start position:0% +quantity okay so we have taken kinetic +energy plus potential energy we look at + + align:start position:0% +energy plus potential energy we look at + + + align:start position:0% +energy plus potential energy we look at +the time derivative and this is sort of + + align:start position:0% +the time derivative and this is sort of + + + align:start position:0% +the time derivative and this is sort of +you know just simple simple algebra what + + align:start position:0% +you know just simple simple algebra what + + + align:start position:0% +you know just simple simple algebra what +you get is 12 M * 2 * V time the + + align:start position:0% +you get is 12 M * 2 * V time the + + + align:start position:0% +you get is 12 M * 2 * V time the +derivative of we with respect to time + + align:start position:0% +derivative of we with respect to time + + + align:start position:0% +derivative of we with respect to time +that is the + + align:start position:0% +that is the + + + align:start position:0% +that is the +acceleration plus um the derivative of + + align:start position:0% +acceleration plus um the derivative of + + + align:start position:0% +acceleration plus um the derivative of +the potential with respect to time and + + align:start position:0% +the potential with respect to time and + + + align:start position:0% +the potential with respect to time and +this can just be written as um mass time + + align:start position:0% +this can just be written as um mass time + + + align:start position:0% +this can just be written as um mass time +velocity time acceleration plus and we + + align:start position:0% +velocity time acceleration plus and we + + + align:start position:0% +velocity time acceleration plus and we +can rewrite the derivative of the + + align:start position:0% +can rewrite the derivative of the + + + align:start position:0% +can rewrite the derivative of the +potential with time as the derivative of + + align:start position:0% +potential with time as the derivative of + + + align:start position:0% +potential with time as the derivative of +the potential with respect to position + + align:start position:0% +the potential with respect to position + + + align:start position:0% +the potential with respect to position +time the derivative of the position with + + align:start position:0% +time the derivative of the position with + + + align:start position:0% +time the derivative of the position with +respect to time and now you see where we + + align:start position:0% +respect to time and now you see where we + + + align:start position:0% +respect to time and now you see where we +are getting to because uh uh this term + + align:start position:0% +are getting to because uh uh this term + + + align:start position:0% +are getting to because uh uh this term +here is equal to minus the force while + + align:start position:0% +here is equal to minus the force while + + + align:start position:0% +here is equal to minus the force while +these terms here is equal to the + + align:start position:0% +these terms here is equal to the + + + align:start position:0% +these terms here is equal to the +velocity and so it goes away with here + + align:start position:0% +velocity and so it goes away with here + + + align:start position:0% +velocity and so it goes away with here +and so what we have is that um the + + align:start position:0% +and so what we have is that um the + + + align:start position:0% +and so what we have is that um the +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +of the total energy with respect to time + + align:start position:0% +of the total energy with respect to time + + + align:start position:0% +of the total energy with respect to time +is equal to the mass time the + + align:start position:0% +is equal to the mass time the + + + align:start position:0% +is equal to the mass time the +acceleration minus the force that is + + align:start position:0% +acceleration minus the force that is + + + align:start position:0% +acceleration minus the force that is +zero because the particle follows Newton + + align:start position:0% +zero because the particle follows Newton + + + align:start position:0% +zero because the particle follows Newton +equation of motion so because of Newton + + align:start position:0% +equation of motion so because of Newton + + + align:start position:0% +equation of motion so because of Newton +equation of motion and because the + + align:start position:0% +equation of motion and because the + + + align:start position:0% +equation of motion and because the +particle follows exactly that Evolution + + align:start position:0% +particle follows exactly that Evolution + + + align:start position:0% +particle follows exactly that Evolution +we have that the sum of the kinetic + + align:start position:0% +we have that the sum of the kinetic + + + align:start position:0% +we have that the sum of the kinetic +energy plus the potential energy needs + + align:start position:0% +energy plus the potential energy needs + + + align:start position:0% +energy plus the potential energy needs +to be conserved um during the evolution + + align:start position:0% +to be conserved um during the evolution + + + align:start position:0% +to be conserved um during the evolution +and that's actually sort of the um + + align:start position:0% +and that's actually sort of the um + + + align:start position:0% +and that's actually sort of the um +fundamental sanity check that you will + + align:start position:0% +fundamental sanity check that you will + + + align:start position:0% +fundamental sanity check that you will +always have and you can always do during + + align:start position:0% +always have and you can always do during + + + align:start position:0% +always have and you can always do during +a molecular Dynamic simulation that is + + align:start position:0% +a molecular Dynamic simulation that is + + + align:start position:0% +a molecular Dynamic simulation that is +you can check that your integration is + + align:start position:0% +you can check that your integration is + + + align:start position:0% +you can check that your integration is +correct by making sure that the total + + align:start position:0% +correct by making sure that the total + + + align:start position:0% +correct by making sure that the total +energy of your system is + + align:start position:0% +energy of your system is + + + align:start position:0% +energy of your system is +conserved okay so what do we do in a + + align:start position:0% +conserved okay so what do we do in a + + + align:start position:0% +conserved okay so what do we do in a +sort of practical molecular Dynamic + + align:start position:0% +sort of practical molecular Dynamic + + + align:start position:0% +sort of practical molecular Dynamic +simulation well the idea is that as in + + align:start position:0% +simulation well the idea is that as in + + + align:start position:0% +simulation well the idea is that as in +the motion of the planets we want to + + align:start position:0% +the motion of the planets we want to + + + align:start position:0% +the motion of the planets we want to +integrate the equation of motions uh + + align:start position:0% +integrate the equation of motions uh + + + align:start position:0% +integrate the equation of motions uh +with this + + align:start position:0% +with this + + + align:start position:0% +with this +that again each particle interacts with + + align:start position:0% +that again each particle interacts with + + + align:start position:0% +that again each particle interacts with +each other each other particle and so + + align:start position:0% +each other each other particle and so + + + align:start position:0% +each other each other particle and so +it's really a many body problem even if + + align:start position:0% +it's really a many body problem even if + + + align:start position:0% +it's really a many body problem even if +it is a classical many body problem and + + align:start position:0% +it is a classical many body problem and + + + align:start position:0% +it is a classical many body problem and +so it's really easier to integrate than + + align:start position:0% +so it's really easier to integrate than + + + align:start position:0% +so it's really easier to integrate than +uh the sort of many body shadinger um um + + align:start position:0% +uh the sort of many body shadinger um um + + + align:start position:0% +uh the sort of many body shadinger um um +equation and in general sort of the way + + align:start position:0% +equation and in general sort of the way + + + align:start position:0% +equation and in general sort of the way +particle interact with each other can be + + align:start position:0% +particle interact with each other can be + + + align:start position:0% +particle interact with each other can be +described by empirical force fields or + + align:start position:0% +described by empirical force fields or + + + align:start position:0% +described by empirical force fields or +in sort of you know the best case + + align:start position:0% +in sort of you know the best case + + + align:start position:0% +in sort of you know the best case +scenario um can be described using uh + + align:start position:0% +scenario um can be described using uh + + + align:start position:0% +scenario um can be described using uh +quantum mechanics density functional + + align:start position:0% +quantum mechanics density functional + + + align:start position:0% +quantum mechanics density functional +Theory Arch F and so what you will have + + align:start position:0% +Theory Arch F and so what you will have + + + align:start position:0% +Theory Arch F and so what you will have +to do in that case is that for every + + align:start position:0% +to do in that case is that for every + + + align:start position:0% +to do in that case is that for every +configuration of your ionic system you + + align:start position:0% +configuration of your ionic system you + + + align:start position:0% +configuration of your ionic system you +need to solve an entire um total energy + + align:start position:0% +need to solve an entire um total energy + + + align:start position:0% +need to solve an entire um total energy +self-consistent problem and that's why + + align:start position:0% +self-consistent problem and that's why + + + align:start position:0% +self-consistent problem and that's why +actually first principle molecular + + align:start position:0% +actually first principle molecular + + + align:start position:0% +actually first principle molecular +Dynamics becomes a very very expensive + + align:start position:0% +Dynamics becomes a very very expensive + + + align:start position:0% +Dynamics becomes a very very expensive +Challenge and we'll see sort of in uh + + align:start position:0% +Challenge and we'll see sort of in uh + + + align:start position:0% +Challenge and we'll see sort of in uh +one of the later classes how this is how + + align:start position:0% +one of the later classes how this is how + + + align:start position:0% +one of the later classes how this is how +this is solved uh there are a lot of + + align:start position:0% +this is solved uh there are a lot of + + + align:start position:0% +this is solved uh there are a lot of +system that can be described accurately + + align:start position:0% +system that can be described accurately + + + align:start position:0% +system that can be described accurately +even with very simple potential um even + + align:start position:0% +even with very simple potential um even + + + align:start position:0% +even with very simple potential um even +more than in the case of the total + + align:start position:0% +more than in the case of the total + + + align:start position:0% +more than in the case of the total +energy certain thermodynamic transitions + + align:start position:0% +energy certain thermodynamic transitions + + + align:start position:0% +energy certain thermodynamic transitions +like the transition from a solid to a + + align:start position:0% +like the transition from a solid to a + + + align:start position:0% +like the transition from a solid to a +liquid can be thought sort of broadly + + align:start position:0% +liquid can be thought sort of broadly + + + align:start position:0% +liquid can be thought sort of broadly +independent of the details of the + + align:start position:0% +independent of the details of the + + + align:start position:0% +independent of the details of the +interacting potentials so even studying + + align:start position:0% +interacting potentials so even studying + + + align:start position:0% +interacting potentials so even studying +a system you know with a Jon potential + + align:start position:0% +a system you know with a Jon potential + + + align:start position:0% +a system you know with a Jon potential +that's after all sort of you know was + + align:start position:0% +that's after all sort of you know was + + + align:start position:0% +that's after all sort of you know was +developed especially to do molecular + + align:start position:0% +developed especially to do molecular + + + align:start position:0% +developed especially to do molecular +Dynamic simulation of rare gas atoms or + + align:start position:0% +Dynamic simulation of rare gas atoms or + + + align:start position:0% +Dynamic simulation of rare gas atoms or +even just studying A system that is made + + align:start position:0% +even just studying A system that is made + + + align:start position:0% +even just studying A system that is made +by hard spheres that don't really + + align:start position:0% +by hard spheres that don't really + + + align:start position:0% +by hard spheres that don't really +interact when they travel in space apart + + align:start position:0% +interact when they travel in space apart + + + align:start position:0% +interact when they travel in space apart +when they really hit each other so what + + align:start position:0% +when they really hit each other so what + + + align:start position:0% +when they really hit each other so what +is called a contact interaction that is + + align:start position:0% +is called a contact interaction that is + + + align:start position:0% +is called a contact interaction that is +zero all the time apart the instant in + + align:start position:0% +zero all the time apart the instant in + + + align:start position:0% +zero all the time apart the instant in +which they sort of the two spheres + + align:start position:0% +which they sort of the two spheres + + + align:start position:0% +which they sort of the two spheres +Collide can sometimes give you um very + + align:start position:0% +Collide can sometimes give you um very + + + align:start position:0% +Collide can sometimes give you um very +accurate qualitative description of the + + align:start position:0% +accurate qualitative description of the + + + align:start position:0% +accurate qualitative description of the +thermodynamic transition in a problem + + align:start position:0% +thermodynamic transition in a problem + + + align:start position:0% +thermodynamic transition in a problem +and + + align:start position:0% +and + + + align:start position:0% +and +um molecular Dynamics actually was sort + + align:start position:0% +um molecular Dynamics actually was sort + + + align:start position:0% +um molecular Dynamics actually was sort +of first introduced really to study + + align:start position:0% +of first introduced really to study + + + align:start position:0% +of first introduced really to study +systems like liquids for which it's very + + align:start position:0% +systems like liquids for which it's very + + + align:start position:0% +systems like liquids for which it's very +difficult to develop analytic techniques + + align:start position:0% +difficult to develop analytic techniques + + + align:start position:0% +difficult to develop analytic techniques +you see if you want to sort of study a + + align:start position:0% +you see if you want to sort of study a + + + align:start position:0% +you see if you want to sort of study a +solid uh you sort of you know you can + + align:start position:0% +solid uh you sort of you know you can + + + align:start position:0% +solid uh you sort of you know you can +actually um choose a potential poal and + + align:start position:0% +actually um choose a potential poal and + + + align:start position:0% +actually um choose a potential poal and +if the potential is simple enough you + + align:start position:0% +if the potential is simple enough you + + + align:start position:0% +if the potential is simple enough you +can analytically calculate the potential + + align:start position:0% +can analytically calculate the potential + + + align:start position:0% +can analytically calculate the potential +energy of a periodic repetition of all + + align:start position:0% +energy of a periodic repetition of all + + + align:start position:0% +energy of a periodic repetition of all +your atoms but if you study um liquid + + align:start position:0% +your atoms but if you study um liquid + + + align:start position:0% +your atoms but if you study um liquid +disorder is really an essential part of + + align:start position:0% +disorder is really an essential part of + + + align:start position:0% +disorder is really an essential part of +the state of the system and so the + + align:start position:0% +the state of the system and so the + + + align:start position:0% +the state of the system and so the +entropic contribution to the free energy + + align:start position:0% +entropic contribution to the free energy + + + align:start position:0% +entropic contribution to the free energy +of this system is fundamental and really + + align:start position:0% +of this system is fundamental and really + + + align:start position:0% +of this system is fundamental and really +there are no uh reasonable analytic ways + + align:start position:0% +there are no uh reasonable analytic ways + + + align:start position:0% +there are no uh reasonable analytic ways +to address a lot of the questions that + + align:start position:0% +to address a lot of the questions that + + + align:start position:0% +to address a lot of the questions that +you have and that's why people really + + align:start position:0% +you have and that's why people really + + + align:start position:0% +you have and that's why people really +sort of moved to solving on the computer + + align:start position:0% +sort of moved to solving on the computer + + + align:start position:0% +sort of moved to solving on the computer +the newon equation of motion and this is + + align:start position:0% +the newon equation of motion and this is + + + align:start position:0% +the newon equation of motion and this is +you know sort of a short history really + + align:start position:0% +you know sort of a short history really + + + align:start position:0% +you know sort of a short history really +of molecular Dynamics reminding you sort + + align:start position:0% +of molecular Dynamics reminding you sort + + + align:start position:0% +of molecular Dynamics reminding you sort +of you know what is the history of + + align:start position:0% +of you know what is the history of + + + align:start position:0% +of you know what is the history of +computer really in + + align:start position:0% +computer really in + + + align:start position:0% +computer really in +1952 one of the first computers Maniac + + align:start position:0% +1952 one of the first computers Maniac + + + align:start position:0% +1952 one of the first computers Maniac +was operational in Los Alamos and that's + + align:start position:0% +was operational in Los Alamos and that's + + + align:start position:0% +was operational in Los Alamos and that's +when Metropolis Nicholas Metropolis + + align:start position:0% +when Metropolis Nicholas Metropolis + + + align:start position:0% +when Metropolis Nicholas Metropolis +collaboration with actually a husband + + align:start position:0% +collaboration with actually a husband + + + align:start position:0% +collaboration with actually a husband +and wife uh couple Rosen blut and Rosen + + align:start position:0% +and wife uh couple Rosen blut and Rosen + + + align:start position:0% +and wife uh couple Rosen blut and Rosen +blut and Teller and Teller developed + + align:start position:0% +blut and Teller and Teller developed + + + align:start position:0% +blut and Teller and Teller developed +what is called the Monte Carlo method + + align:start position:0% +what is called the Monte Carlo method + + + align:start position:0% +what is called the Monte Carlo method +that was sort of a very powerful method + + align:start position:0% +that was sort of a very powerful method + + + align:start position:0% +that was sort of a very powerful method +to address exactly this entropic free + + align:start position:0% +to address exactly this entropic free + + + align:start position:0% +to address exactly this entropic free +energy problem and that you'll see in + + align:start position:0% +energy problem and that you'll see in + + + align:start position:0% +energy problem and that you'll see in +one of the later uh classes but really + + align:start position:0% +one of the later uh classes but really + + + align:start position:0% +one of the later uh classes but really +sort of 1956 is the first molecular + + align:start position:0% +sort of 1956 is the first molecular + + + align:start position:0% +sort of 1956 is the first molecular +Dynamic simulation uh by Alder and Wayne + + align:start position:0% +Dynamic simulation uh by Alder and Wayne + + + align:start position:0% +Dynamic simulation uh by Alder and Wayne +W as I said in looking at the Dynamics + + align:start position:0% +W as I said in looking at the Dynamics + + + align:start position:0% +W as I said in looking at the Dynamics +of hard spheres and sort of these are + + align:start position:0% +of hard spheres and sort of these are + + + align:start position:0% +of hard spheres and sort of these are +sort of the Milestone papers vineard + + align:start position:0% +sort of the Milestone papers vineard + + + align:start position:0% +sort of the Milestone papers vineard +studying radiation damage in Copper what + + align:start position:0% +studying radiation damage in Copper what + + + align:start position:0% +studying radiation damage in Copper what +happens when you have you know a sort of + + align:start position:0% +happens when you have you know a sort of + + + align:start position:0% +happens when you have you know a sort of +copper atom that is really sort of put + + align:start position:0% +copper atom that is really sort of put + + + align:start position:0% +copper atom that is really sort of put +in motion by a very energetic radiation + + align:start position:0% +in motion by a very energetic radiation + + + align:start position:0% +in motion by a very energetic radiation +kicking it and starting sort of running + + align:start position:0% +kicking it and starting sort of running + + + align:start position:0% +kicking it and starting sort of running +around and really this is the the + + align:start position:0% +around and really this is the the + + + align:start position:0% +around and really this is the the +classic paper of anur Raman starting + + align:start position:0% +classic paper of anur Raman starting + + + align:start position:0% +classic paper of anur Raman starting +with Al lener joh potential the Dynamics + + align:start position:0% +with Al lener joh potential the Dynamics + + + align:start position:0% +with Al lener joh potential the Dynamics +of liquid argon again AL lener joh + + align:start position:0% +of liquid argon again AL lener joh + + + align:start position:0% +of liquid argon again AL lener joh +potential is actually accurate to + + align:start position:0% +potential is actually accurate to + + + align:start position:0% +potential is actually accurate to +describe rare gases that ultimately sort + + align:start position:0% +describe rare gases that ultimately sort + + + align:start position:0% +describe rare gases that ultimately sort +of repel each other at very close + + align:start position:0% +of repel each other at very close + + + align:start position:0% +of repel each other at very close +distance and at large distances attract + + align:start position:0% +distance and at large distances attract + + + align:start position:0% +distance and at large distances attract +each other with this weak dipole dipole + + align:start position:0% +each other with this weak dipole dipole + + + align:start position:0% +each other with this weak dipole dipole +interaction that is that goes us one/ R + + align:start position:0% +interaction that is that goes us one/ R + + + align:start position:0% +interaction that is that goes us one/ R +to the 6th and then really the sort of + + align:start position:0% +to the 6th and then really the sort of + + + align:start position:0% +to the 6th and then really the sort of +first abinal molecular Dynamics and the + + align:start position:0% +first abinal molecular Dynamics and the + + + align:start position:0% +first abinal molecular Dynamics and the +first theory for abin molecular Dynamics + + align:start position:0% +first theory for abin molecular Dynamics + + + align:start position:0% +first theory for abin molecular Dynamics +was developed in the mid 80s by Karen + + align:start position:0% +was developed in the mid 80s by Karen + + + align:start position:0% +was developed in the mid 80s by Karen +parinello okay + + align:start position:0% + + + + align:start position:0% + +now there is a sort of uh Universal way + + align:start position:0% +now there is a sort of uh Universal way + + + align:start position:0% +now there is a sort of uh Universal way +to think at this dynamics of your + + align:start position:0% +to think at this dynamics of your + + + align:start position:0% +to think at this dynamics of your +classical system composed of n particles + + align:start position:0% +classical system composed of n particles + + + align:start position:0% +classical system composed of n particles +and as we have said uh since that they + + align:start position:0% +and as we have said uh since that they + + + align:start position:0% +and as we have said uh since that they +follow Newton equation of motion what we + + align:start position:0% +follow Newton equation of motion what we + + + align:start position:0% +follow Newton equation of motion what we +really need to track the only quantities + + align:start position:0% +really need to track the only quantities + + + align:start position:0% +really need to track the only quantities +that we need to track is their position + + align:start position:0% +that we need to track is their position + + + align:start position:0% +that we need to track is their position +as a function of time and their velocity + + align:start position:0% +as a function of time and their velocity + + + align:start position:0% +as a function of time and their velocity +as a function of time and generally + + align:start position:0% +as a function of time and generally + + + align:start position:0% +as a function of time and generally +speaking the kinetic energy is just a + + align:start position:0% +speaking the kinetic energy is just a + + + align:start position:0% +speaking the kinetic energy is just a +function of the velocities and the + + align:start position:0% +function of the velocities and the + + + align:start position:0% +function of the velocities and the +potential energy is just a function of + + align:start position:0% +potential energy is just a function of + + + align:start position:0% +potential energy is just a function of +the positions so if you have n particles + + align:start position:0% +the positions so if you have n particles + + + align:start position:0% +the positions so if you have n particles +you really have to follow in time six + + align:start position:0% +you really have to follow in time six + + + align:start position:0% +you really have to follow in time six +six n variables and if we Define for a + + align:start position:0% +six n variables and if we Define for a + + + align:start position:0% +six n variables and if we Define for a +moment a six dimensional space what we + + align:start position:0% +moment a six dimensional space what we + + + align:start position:0% +moment a six dimensional space what we +really have is that an instantaneous + + align:start position:0% +really have is that an instantaneous + + + align:start position:0% +really have is that an instantaneous +state of your dynamical system that is + + align:start position:0% +state of your dynamical system that is + + + align:start position:0% +state of your dynamical system that is +all its position and all its velocity + + align:start position:0% +all its position and all its velocity + + + align:start position:0% +all its position and all its velocity +can be represented by a single point + + align:start position:0% +can be represented by a single point + + + align:start position:0% +can be represented by a single point +point in this 6n dimensional space so if + + align:start position:0% +point in this 6n dimensional space so if + + + align:start position:0% +point in this 6n dimensional space so if +you've got just a hydrogen molecule with + + align:start position:0% +you've got just a hydrogen molecule with + + + align:start position:0% +you've got just a hydrogen molecule with +two nuclei what you really need is a + + align:start position:0% +two nuclei what you really need is a + + + align:start position:0% +two nuclei what you really need is a +point in six Dimension if you have a + + align:start position:0% +point in six Dimension if you have a + + + align:start position:0% +point in six Dimension if you have a +water molecule you need a point in nine + + align:start position:0% +water molecule you need a point in nine + + + align:start position:0% +water molecule you need a point in nine +dimensions and the evolution + + align:start position:0% +dimensions and the evolution + + + align:start position:0% +dimensions and the evolution +um sorry if you have a water molecule + + align:start position:0% +um sorry if you have a water molecule + + + align:start position:0% +um sorry if you have a water molecule +you need um point in a 18 dimensions and + + align:start position:0% +you need um point in a 18 dimensions and + + + align:start position:0% +you need um point in a 18 dimensions and +if you have a hydrogen molecule you need + + align:start position:0% +if you have a hydrogen molecule you need + + + align:start position:0% +if you have a hydrogen molecule you need +a point in 12 Dimension and the dynamic + + align:start position:0% +a point in 12 Dimension and the dynamic + + + align:start position:0% +a point in 12 Dimension and the dynamic +IAL evolution of your system is + + align:start position:0% +IAL evolution of your system is + + + align:start position:0% +IAL evolution of your system is +described exactly by the evolution of + + align:start position:0% +described exactly by the evolution of + + + align:start position:0% +described exactly by the evolution of +this point so we often think at this + + align:start position:0% +this point so we often think at this + + + align:start position:0% +this point so we often think at this +phase space uh that we have for n + + align:start position:0% +phase space uh that we have for n + + + align:start position:0% +phase space uh that we have for n +particle 6 n dimension of which uh let's + + align:start position:0% +particle 6 n dimension of which uh let's + + + align:start position:0% +particle 6 n dimension of which uh let's +sort of try to draw a bit Dimension uh + + align:start position:0% +sort of try to draw a bit Dimension uh + + + align:start position:0% +sort of try to draw a bit Dimension uh +three n of them those represented in + + align:start position:0% +three n of them those represented in + + + align:start position:0% +three n of them those represented in +green will really represent the + + align:start position:0% +green will really represent the + + + align:start position:0% +green will really represent the +positions and the other three n will + + align:start position:0% +positions and the other three n will + + + align:start position:0% +positions and the other three n will +represent velocities okay and obviously + + align:start position:0% +represent velocities okay and obviously + + + align:start position:0% +represent velocities okay and obviously +this is all orthogonal Dimension and + + align:start position:0% +this is all orthogonal Dimension and + + + align:start position:0% +this is all orthogonal Dimension and +your point will be somewhere a certain + + align:start position:0% +your point will be somewhere a certain + + + align:start position:0% +your point will be somewhere a certain +instant in time t uh we have a set of + + align:start position:0% +instant in time t uh we have a set of + + + align:start position:0% +instant in time t uh we have a set of +velocities we have a set of position and + + align:start position:0% +velocities we have a set of position and + + + align:start position:0% +velocities we have a set of position and +the Newton equation of motion will make + + align:start position:0% +the Newton equation of motion will make + + + align:start position:0% +the Newton equation of motion will make +it evolve in this phase space so really + + align:start position:0% +it evolve in this phase space so really + + + align:start position:0% +it evolve in this phase space so really +your molecular Dynamic integration + + align:start position:0% +your molecular Dynamic integration + + + align:start position:0% +your molecular Dynamic integration +consists in following in time this uh + + align:start position:0% +consists in following in time this uh + + + align:start position:0% +consists in following in time this uh +this Evolution and that evolution is in + + align:start position:0% +this Evolution and that evolution is in + + + align:start position:0% +this Evolution and that evolution is in +principle analytically and uniquely + + align:start position:0% +principle analytically and uniquely + + + align:start position:0% +principle analytically and uniquely +defined uh once you know the position + + align:start position:0% +defined uh once you know the position + + + align:start position:0% +defined uh once you know the position +and the velocities at every instant uh + + align:start position:0% +and the velocities at every instant uh + + + align:start position:0% +and the velocities at every instant uh +and well we we'll see that later okay so + + align:start position:0% +and well we we'll see that later okay so + + + align:start position:0% +and well we we'll see that later okay so +what do we do once uh we have a + + align:start position:0% +what do we do once uh we have a + + + align:start position:0% +what do we do once uh we have a +computational algorith that allows us to + + align:start position:0% +computational algorith that allows us to + + + align:start position:0% +computational algorith that allows us to +evolve this point in Phase space and I + + align:start position:0% +evolve this point in Phase space and I + + + align:start position:0% +evolve this point in Phase space and I +sort of summarized here sort of the + + align:start position:0% +sort of summarized here sort of the + + + align:start position:0% +sort of summarized here sort of the +three main goals that could follow from + + align:start position:0% +three main goals that could follow from + + + align:start position:0% +three main goals that could follow from +a molecular Dynamic simulation in the + + align:start position:0% +a molecular Dynamic simulation in the + + + align:start position:0% +a molecular Dynamic simulation in the +sort of the order that we'll see them uh + + align:start position:0% +sort of the order that we'll see them uh + + + align:start position:0% +sort of the order that we'll see them uh +really one of the most common ones is to + + align:start position:0% +really one of the most common ones is to + + + align:start position:0% +really one of the most common ones is to +use molecular Dynamic simulations to + + align:start position:0% +use molecular Dynamic simulations to + + + align:start position:0% +use molecular Dynamic simulations to +calculate thermodynamical properties + + align:start position:0% +calculate thermodynamical properties + + + align:start position:0% +calculate thermodynamical properties +that is to calculate what we call + + align:start position:0% +that is to calculate what we call + + + align:start position:0% +that is to calculate what we call +Ensemble averages um suppose that you + + align:start position:0% +Ensemble averages um suppose that you + + + align:start position:0% +Ensemble averages um suppose that you +have + + align:start position:0% +have + + + align:start position:0% +have +a system like a solid and you have + + align:start position:0% +a system like a solid and you have + + + align:start position:0% +a system like a solid and you have +calculated say it's latis parameter like + + align:start position:0% +calculated say it's latis parameter like + + + align:start position:0% +calculated say it's latis parameter like +you're doing in lab two or lab three and + + align:start position:0% +you're doing in lab two or lab three and + + + align:start position:0% +you're doing in lab two or lab three and +suppose that you start heating up this + + align:start position:0% +suppose that you start heating up this + + + align:start position:0% +suppose that you start heating up this +solid what happens well the atoms in the + + align:start position:0% +solid what happens well the atoms in the + + + align:start position:0% +solid what happens well the atoms in the +classical sense start oscillating more + + align:start position:0% +classical sense start oscillating more + + + align:start position:0% +classical sense start oscillating more +and more and you know from experience + + align:start position:0% +and more and you know from experience + + + align:start position:0% +and more and you know from experience +that most solids starts expanding when + + align:start position:0% +that most solids starts expanding when + + + align:start position:0% +that most solids starts expanding when +you warm them up so a molecular Dynamic + + align:start position:0% +you warm them up so a molecular Dynamic + + + align:start position:0% +you warm them up so a molecular Dynamic +simulation could tell you how much a + + align:start position:0% +simulation could tell you how much a + + + align:start position:0% +simulation could tell you how much a +solid expands when you heat it up + + align:start position:0% +solid expands when you heat it up + + + align:start position:0% +solid expands when you heat it up +because basically you start evolving + + align:start position:0% +because basically you start evolving + + + align:start position:0% +because basically you start evolving +your system from zero temperature and + + align:start position:0% +your system from zero temperature and + + + align:start position:0% +your system from zero temperature and +then you increase its temperature and + + align:start position:0% +then you increase its temperature and + + + align:start position:0% +then you increase its temperature and +really temperature remember is just the + + align:start position:0% +really temperature remember is just the + + + align:start position:0% +really temperature remember is just the +average kinetic energy of the ions and + + align:start position:0% +average kinetic energy of the ions and + + + align:start position:0% +average kinetic energy of the ions and +as you increase the temperature the ions + + align:start position:0% +as you increase the temperature the ions + + + align:start position:0% +as you increase the temperature the ions +oscillate more and more and if you let + + align:start position:0% +oscillate more and more and if you let + + + align:start position:0% +oscillate more and more and if you let +your unit cell expand or contract in + + align:start position:0% +your unit cell expand or contract in + + + align:start position:0% +your unit cell expand or contract in +time following what is the stress + + align:start position:0% +time following what is the stress + + + align:start position:0% +time following what is the stress +overall of all the atoms in your unit + + align:start position:0% +overall of all the atoms in your unit + + + align:start position:0% +overall of all the atoms in your unit +cell you'll see that your system sort of + + align:start position:0% +cell you'll see that your system sort of + + + align:start position:0% +cell you'll see that your system sort of +you know increases the dimension of the + + align:start position:0% +you know increases the dimension of the + + + align:start position:0% +you know increases the dimension of the +unit cell and starts oscillating around + + align:start position:0% +unit cell and starts oscillating around + + + align:start position:0% +unit cell and starts oscillating around +a value that's really an average + + align:start position:0% +a value that's really an average + + + align:start position:0% +a value that's really an average +depending on temperature and um this all + + align:start position:0% +depending on temperature and um this all + + + align:start position:0% +depending on temperature and um this all +these sort of you know statements can be + + align:start position:0% +these sort of you know statements can be + + + align:start position:0% +these sort of you know statements can be +actually made formally in a way that + + align:start position:0% +actually made formally in a way that + + + align:start position:0% +actually made formally in a way that +we'll see in a moment that is the + + align:start position:0% +we'll see in a moment that is the + + + align:start position:0% +we'll see in a moment that is the +language of thermodynamics that is if we + + align:start position:0% +language of thermodynamics that is if we + + + align:start position:0% +language of thermodynamics that is if we +have a finite temperature + + align:start position:0% +have a finite temperature + + + align:start position:0% +have a finite temperature +will have a certain probability + + align:start position:0% +will have a certain probability + + + align:start position:0% +will have a certain probability +associated with every microscopic + + align:start position:0% +associated with every microscopic + + + align:start position:0% +associated with every microscopic +configuration okay so if you if you are + + align:start position:0% +configuration okay so if you if you are + + + align:start position:0% +configuration okay so if you if you are +at zero temperature really what you have + + align:start position:0% +at zero temperature really what you have + + + align:start position:0% +at zero temperature really what you have +is that you have probability one to be + + align:start position:0% +is that you have probability one to be + + + align:start position:0% +is that you have probability one to be +in the lowest energy State possible and + + align:start position:0% +in the lowest energy State possible and + + + align:start position:0% +in the lowest energy State possible and +probability zero of being in any other + + align:start position:0% +probability zero of being in any other + + + align:start position:0% +probability zero of being in any other +energy state if you start increasing + + align:start position:0% +energy state if you start increasing + + + align:start position:0% +energy state if you start increasing +your + + align:start position:0% +your + + + align:start position:0% +your +temperature states that are + + align:start position:0% +temperature states that are + + + align:start position:0% +temperature states that are +energetically similar to the ground + + align:start position:0% +energetically similar to the ground + + + align:start position:0% +energetically similar to the ground +state but not really the ground state + + align:start position:0% +state but not really the ground state + + + align:start position:0% +state but not really the ground state +start to have a certain probability of + + align:start position:0% +start to have a certain probability of + + + align:start position:0% +start to have a certain probability of +being occupied and the more temperature + + align:start position:0% +being occupied and the more temperature + + + align:start position:0% +being occupied and the more temperature +you have the more very costly + + align:start position:0% +you have the more very costly + + + align:start position:0% +you have the more very costly +configurations can be accessed by your + + align:start position:0% +configurations can be accessed by your + + + align:start position:0% +configurations can be accessed by your +system and really the average properties + + align:start position:0% +system and really the average properties + + + align:start position:0% +system and really the average properties +at a finite temperature need to be an + + align:start position:0% +at a finite temperature need to be an + + + align:start position:0% +at a finite temperature need to be an +average over all this possible State + + align:start position:0% +average over all this possible State + + + align:start position:0% +average over all this possible State +weight with their appropriate + + align:start position:0% +weight with their appropriate + + + align:start position:0% +weight with their appropriate +thermodynamic weight Wade with the + + align:start position:0% +thermodynamic weight Wade with the + + + align:start position:0% +thermodynamic weight Wade with the +probability of being in that state and + + align:start position:0% +probability of being in that state and + + + align:start position:0% +probability of being in that state and +so this is what an ensemble average does + + align:start position:0% +so this is what an ensemble average does + + + align:start position:0% +so this is what an ensemble average does +really it sort of tries to span all the + + align:start position:0% +really it sort of tries to span all the + + + align:start position:0% +really it sort of tries to span all the +possible States in a system with a + + align:start position:0% +possible States in a system with a + + + align:start position:0% +possible States in a system with a +probability that is proportional to + + align:start position:0% +probability that is proportional to + + + align:start position:0% +probability that is proportional to +their thermodynamical weight and then + + align:start position:0% +their thermodynamical weight and then + + + align:start position:0% +their thermodynamical weight and then +for each state you can calculate a + + align:start position:0% +for each state you can calculate a + + + align:start position:0% +for each state you can calculate a +certain property like what is it sort of + + align:start position:0% +certain property like what is it sort of + + + align:start position:0% +certain property like what is it sort of +average potential energy what is it sort + + align:start position:0% +average potential energy what is it sort + + + align:start position:0% +average potential energy what is it sort +of + + align:start position:0% +of + + + align:start position:0% +of +uh equilibri what is its + + align:start position:0% +uh equilibri what is its + + + align:start position:0% +uh equilibri what is its +um latis parameter and so on and out of + + align:start position:0% +um latis parameter and so on and out of + + + align:start position:0% +um latis parameter and so on and out of +that you can sort of calculate the + + align:start position:0% +that you can sort of calculate the + + + align:start position:0% +that you can sort of calculate the +average thermodynamical property and + + align:start position:0% +average thermodynamical property and + + + align:start position:0% +average thermodynamical property and +we'll see actually example in a moment + + align:start position:0% +we'll see actually example in a moment + + + align:start position:0% +we'll see actually example in a moment +so we'll see sort of a practical + + align:start position:0% +so we'll see sort of a practical + + + align:start position:0% +so we'll see sort of a practical +application of this um the other thing + + align:start position:0% +application of this um the other thing + + + align:start position:0% +application of this um the other thing +that you can do with a molecular Dynamic + + align:start position:0% +that you can do with a molecular Dynamic + + + align:start position:0% +that you can do with a molecular Dynamic +simulator is actually study the + + align:start position:0% +simulator is actually study the + + + align:start position:0% +simulator is actually study the +evolution in real time of your system so + + align:start position:0% +evolution in real time of your system so + + + align:start position:0% +evolution in real time of your system so +you could actually study a chemical + + align:start position:0% +you could actually study a chemical + + + align:start position:0% +you could actually study a chemical +reaction what happens + + align:start position:0% +reaction what happens + + + align:start position:0% +reaction what happens +if you have say an explosive molecule + + align:start position:0% +if you have say an explosive molecule + + + align:start position:0% +if you have say an explosive molecule +that is decomposing okay and in + + align:start position:0% +that is decomposing okay and in + + + align:start position:0% +that is decomposing okay and in +particular whenever you have sort of you + + align:start position:0% +particular whenever you have sort of you + + + align:start position:0% +particular whenever you have sort of you +know chemical reaction that tends to be + + align:start position:0% +know chemical reaction that tends to be + + + align:start position:0% +know chemical reaction that tends to be +bond breaking and bond forming reaction + + align:start position:0% +bond breaking and bond forming reaction + + + align:start position:0% +bond breaking and bond forming reaction +you'll probably need to use a quantum + + align:start position:0% +you'll probably need to use a quantum + + + align:start position:0% +you'll probably need to use a quantum +mechanical approach but in principle you + + align:start position:0% +mechanical approach but in principle you + + + align:start position:0% +mechanical approach but in principle you +can set up your system in an initial + + align:start position:0% +can set up your system in an initial + + + align:start position:0% +can set up your system in an initial +configuration and see what happens as + + align:start position:0% +configuration and see what happens as + + + align:start position:0% +configuration and see what happens as +you evolve in time you could look at a + + align:start position:0% +you evolve in time you could look at a + + + align:start position:0% +you evolve in time you could look at a +catalytic reaction say maybe you're + + align:start position:0% +catalytic reaction say maybe you're + + + align:start position:0% +catalytic reaction say maybe you're +interested in studying fuel cells and + + align:start position:0% +interested in studying fuel cells and + + + align:start position:0% +interested in studying fuel cells and +you want to see how a hydrogen molecule + + align:start position:0% +you want to see how a hydrogen molecule + + + align:start position:0% +you want to see how a hydrogen molecule +decomposes when it arrives on a platinum + + align:start position:0% +decomposes when it arrives on a platinum + + + align:start position:0% +decomposes when it arrives on a platinum +surface well you can take your hydrogen + + align:start position:0% +surface well you can take your hydrogen + + + align:start position:0% +surface well you can take your hydrogen +molecule and sort of you know project it + + align:start position:0% +molecule and sort of you know project it + + + align:start position:0% +molecule and sort of you know project it +delicately towards the Platinum surface + + align:start position:0% +delicately towards the Platinum surface + + + align:start position:0% +delicately towards the Platinum surface +and follow with your molecular Dynamic + + align:start position:0% +and follow with your molecular Dynamic + + + align:start position:0% +and follow with your molecular Dynamic +techniques the Dynamics of all these + + align:start position:0% +techniques the Dynamics of all these + + + align:start position:0% +techniques the Dynamics of all these +nuclei as the molecule chemisorbs and + + align:start position:0% +nuclei as the molecule chemisorbs and + + + align:start position:0% +nuclei as the molecule chemisorbs and +dissociate in + + align:start position:0% +dissociate in + + + align:start position:0% +dissociate in +time and then really sort of the last + + align:start position:0% +time and then really sort of the last + + + align:start position:0% +time and then really sort of the last +um uh application of molecular Dynamics + + align:start position:0% +um uh application of molecular Dynamics + + + align:start position:0% +um uh application of molecular Dynamics +uh is a sort of more of a + + align:start position:0% +uh is a sort of more of a + + + align:start position:0% +uh is a sort of more of a +optimization algorithm uh there are + + align:start position:0% +optimization algorithm uh there are + + + align:start position:0% +optimization algorithm uh there are +problems in which it's very complex to + + align:start position:0% +problems in which it's very complex to + + + align:start position:0% +problems in which it's very complex to +find what is the lowest possible + + align:start position:0% +find what is the lowest possible + + + align:start position:0% +find what is the lowest possible +solution what is the optimal solution + + align:start position:0% +solution what is the optimal solution + + + align:start position:0% +solution what is the optimal solution +that is you know you could sort of you + + align:start position:0% +that is you know you could sort of you + + + align:start position:0% +that is you know you could sort of you +know try to find out what is the schedle + + align:start position:0% +know try to find out what is the schedle + + + align:start position:0% +know try to find out what is the schedle +of all your flights in a air plane comp + + align:start position:0% +of all your flights in a air plane comp + + + align:start position:0% +of all your flights in a air plane comp +and obviously that's a complex + + align:start position:0% +and obviously that's a complex + + + align:start position:0% +and obviously that's a complex +optimization problem because you can't + + align:start position:0% +optimization problem because you can't + + + align:start position:0% +optimization problem because you can't +move one plane at a time and figure out + + align:start position:0% +move one plane at a time and figure out + + + align:start position:0% +move one plane at a time and figure out +what is the best possible solution + + align:start position:0% +what is the best possible solution + + + align:start position:0% +what is the best possible solution +because there might be a completely + + align:start position:0% +because there might be a completely + + + align:start position:0% +because there might be a completely +different choice of planes and + + align:start position:0% +different choice of planes and + + + align:start position:0% +different choice of planes and +itineraries that actually gives you a + + align:start position:0% +itineraries that actually gives you a + + + align:start position:0% +itineraries that actually gives you a +best performance overall on the net and + + align:start position:0% +best performance overall on the net and + + + align:start position:0% +best performance overall on the net and +so you can always sort of take one + + align:start position:0% +so you can always sort of take one + + + align:start position:0% +so you can always sort of take one +optimization problem and express a cost + + align:start position:0% +optimization problem and express a cost + + + align:start position:0% +optimization problem and express a cost +function that is sort of depending on + + align:start position:0% +function that is sort of depending on + + + align:start position:0% +function that is sort of depending on +what is you're interested sort of + + align:start position:0% +what is you're interested sort of + + + align:start position:0% +what is you're interested sort of +minimize the sort of amount of oil I say + + align:start position:0% +minimize the sort of amount of oil I say + + + align:start position:0% +minimize the sort of amount of oil I say +used in running all these routs so when + + align:start position:0% +used in running all these routs so when + + + align:start position:0% +used in running all these routs so when +you have a cost function of a very + + align:start position:0% +you have a cost function of a very + + + align:start position:0% +you have a cost function of a very +complex problem you have really an + + align:start position:0% +complex problem you have really an + + + align:start position:0% +complex problem you have really an +object that depends on many + + align:start position:0% +object that depends on many + + + align:start position:0% +object that depends on many +variables and that has a lot of possible + + align:start position:0% +variables and that has a lot of possible + + + align:start position:0% +variables and that has a lot of possible +Minima okay so this would be really the + + align:start position:0% +Minima okay so this would be really the + + + align:start position:0% +Minima okay so this would be really the +problem of + + align:start position:0% +problem of + + + align:start position:0% +problem of +optimizing uh the airor roots of a uh + + align:start position:0% +optimizing uh the airor roots of a uh + + + align:start position:0% +optimizing uh the airor roots of a uh +Airline what you have is a lot of + + align:start position:0% +Airline what you have is a lot of + + + align:start position:0% +Airline what you have is a lot of +possible variables and there are a lot + + align:start position:0% +possible variables and there are a lot + + + align:start position:0% +possible variables and there are a lot +of reasonable Solutions but you really + + align:start position:0% +of reasonable Solutions but you really + + + align:start position:0% +of reasonable Solutions but you really +want to find the one that is the best + + align:start position:0% +want to find the one that is the best + + + align:start position:0% +want to find the one that is the best +for you something something like this + + align:start position:0% +for you something something like this + + + align:start position:0% +for you something something like this +and molecular Dynamics can actually help + + align:start position:0% +and molecular Dynamics can actually help + + + align:start position:0% +and molecular Dynamics can actually help +to solve this problem because it's a + + align:start position:0% +to solve this problem because it's a + + + align:start position:0% +to solve this problem because it's a +problem that is absolutely analogous of + + align:start position:0% +problem that is absolutely analogous of + + + align:start position:0% +problem that is absolutely analogous of +having a system of interacting particle + + align:start position:0% +having a system of interacting particle + + + align:start position:0% +having a system of interacting particle +that has a certain potential energy + + align:start position:0% +that has a certain potential energy + + + align:start position:0% +that has a certain potential energy +surface and trying to explore that + + align:start position:0% +surface and trying to explore that + + + align:start position:0% +surface and trying to explore that +potential energy surface moving around + + align:start position:0% +potential energy surface moving around + + + align:start position:0% +potential energy surface moving around +until you find the lowest minimum you + + align:start position:0% +until you find the lowest minimum you + + + align:start position:0% +until you find the lowest minimum you +could think at this as you know a + + align:start position:0% +could think at this as you know a + + + align:start position:0% +could think at this as you know a +mountain range and you have your skares + + align:start position:0% +mountain range and you have your skares + + + align:start position:0% +mountain range and you have your skares +that are really your particles moving + + align:start position:0% +that are really your particles moving + + + align:start position:0% +that are really your particles moving +around and you want to sort of let the + + align:start position:0% +around and you want to sort of let the + + + align:start position:0% +around and you want to sort of let the +skiers ski around as much as possible + + align:start position:0% +skiers ski around as much as possible + + + align:start position:0% +skiers ski around as much as possible +until they find the minimum energy State + + align:start position:0% +until they find the minimum energy State + + + align:start position:0% +until they find the minimum energy State +and so you can use a thermodynamical + + align:start position:0% +and so you can use a thermodynamical + + + align:start position:0% +and so you can use a thermodynamical +analogy you heat up your system that + + align:start position:0% +analogy you heat up your system that + + + align:start position:0% +analogy you heat up your system that +means that every particle has a lot of + + align:start position:0% +means that every particle has a lot of + + + align:start position:0% +means that every particle has a lot of +kinetic energy so sort of you know + + align:start position:0% +kinetic energy so sort of you know + + + align:start position:0% +kinetic energy so sort of you know +having a lot of kinetic energy can + + align:start position:0% +having a lot of kinetic energy can + + + align:start position:0% +having a lot of kinetic energy can +easily overcome any kind of potential + + align:start position:0% +easily overcome any kind of potential + + + align:start position:0% +easily overcome any kind of potential +barrier and you have a lot of this + + align:start position:0% +barrier and you have a lot of this + + + align:start position:0% +barrier and you have a lot of this +particle moving around and then you sort + + align:start position:0% +particle moving around and then you sort + + + align:start position:0% +particle moving around and then you sort +of cool them down slowly and as you cool + + align:start position:0% +of cool them down slowly and as you cool + + + align:start position:0% +of cool them down slowly and as you cool +them down they'll start piling up in the + + align:start position:0% +them down they'll start piling up in the + + + align:start position:0% +them down they'll start piling up in the +lowest possible energy states and once + + align:start position:0% +lowest possible energy states and once + + + align:start position:0% +lowest possible energy states and once +you have reached very slowly zero + + align:start position:0% +you have reached very slowly zero + + + align:start position:0% +you have reached very slowly zero +temperature you look where all your + + align:start position:0% +temperature you look where all your + + + align:start position:0% +temperature you look where all your +particles have ended up and so you have + + align:start position:0% +particles have ended up and so you have + + + align:start position:0% +particles have ended up and so you have +at least you know a good sampling of the + + align:start position:0% +at least you know a good sampling of the + + + align:start position:0% +at least you know a good sampling of the +relevant Minima in your potential energy + + align:start position:0% +relevant Minima in your potential energy + + + align:start position:0% +relevant Minima in your potential energy +surface so moleular Dynamics and this is + + align:start position:0% +surface so moleular Dynamics and this is + + + align:start position:0% +surface so moleular Dynamics and this is +called simulated aning in this context + + align:start position:0% +called simulated aning in this context + + + align:start position:0% +called simulated aning in this context +can actually be used as an optimization + + align:start position:0% +can actually be used as an optimization + + + align:start position:0% +can actually be used as an optimization +as an optimization + + align:start position:0% + + + + align:start position:0% + +technique and uh we don't have sort of + + align:start position:0% +technique and uh we don't have sort of + + + align:start position:0% +technique and uh we don't have sort of +you know to go as far as the case of an + + align:start position:0% +you know to go as far as the case of an + + + align:start position:0% +you know to go as far as the case of an +airline or what is called the traveling + + align:start position:0% +airline or what is called the traveling + + + align:start position:0% +airline or what is called the traveling +salesman problem but often what we have + + align:start position:0% +salesman problem but often what we have + + + align:start position:0% +salesman problem but often what we have +is that we have system that has fairly + + align:start position:0% +is that we have system that has fairly + + + align:start position:0% +is that we have system that has fairly +complicated to + + align:start position:0% +complicated to + + + align:start position:0% +complicated to +characterize uh say we want to describe + + align:start position:0% +characterize uh say we want to describe + + + align:start position:0% +characterize uh say we want to describe +maybe an interface between uh you know + + align:start position:0% +maybe an interface between uh you know + + + align:start position:0% +maybe an interface between uh you know +perfect silicon crystal and the sio2 + + align:start position:0% +perfect silicon crystal and the sio2 + + + align:start position:0% +perfect silicon crystal and the sio2 +substrate because we are in the sort of + + align:start position:0% +substrate because we are in the sort of + + + align:start position:0% +substrate because we are in the sort of +electronic industry well I mean we have + + align:start position:0% +electronic industry well I mean we have + + + align:start position:0% +electronic industry well I mean we have +a problem because how how do we + + align:start position:0% +a problem because how how do we + + + align:start position:0% +a problem because how how do we +construct the interface between a + + align:start position:0% +construct the interface between a + + + align:start position:0% +construct the interface between a +crystalline solid and an amorphous + + align:start position:0% +crystalline solid and an amorphous + + + align:start position:0% +crystalline solid and an amorphous +system I mean we can try putting atoms + + align:start position:0% +system I mean we can try putting atoms + + + align:start position:0% +system I mean we can try putting atoms +in reasonable position but it's never + + align:start position:0% +in reasonable position but it's never + + + align:start position:0% +in reasonable position but it's never +going to work very well and so what we + + align:start position:0% +going to work very well and so what we + + + align:start position:0% +going to work very well and so what we +can do is actually use a molecular + + align:start position:0% +can do is actually use a molecular + + + align:start position:0% +can do is actually use a molecular +Dynamic techniques to let the atoms + + align:start position:0% +Dynamic techniques to let the atoms + + + align:start position:0% +Dynamic techniques to let the atoms +evolve according to their interaction + + align:start position:0% +evolve according to their interaction + + + align:start position:0% +evolve according to their interaction +and to the Newton equation of motion and + + align:start position:0% +and to the Newton equation of motion and + + + align:start position:0% +and to the Newton equation of motion and +somehow find by themselves uh slightly + + align:start position:0% +somehow find by themselves uh slightly + + + align:start position:0% +somehow find by themselves uh slightly +more favorable green Minima instead of + + align:start position:0% +more favorable green Minima instead of + + + align:start position:0% +more favorable green Minima instead of +the initial configuration in which we + + align:start position:0% +the initial configuration in which we + + + align:start position:0% +the initial configuration in which we +have put + + align:start position:0% +have put + + + align:start position:0% +have put +them okay so in principle if you had you + + align:start position:0% +them okay so in principle if you had you + + + align:start position:0% +them okay so in principle if you had you +know um infinite computing power or + + align:start position:0% +know um infinite computing power or + + + align:start position:0% +know um infinite computing power or +infinite mathematical + + align:start position:0% +infinite mathematical + + + align:start position:0% +infinite mathematical +Powers you would have really solved the + + align:start position:0% +Powers you would have really solved the + + + align:start position:0% +Powers you would have really solved the +problem of characterizing on a computer + + align:start position:0% +problem of characterizing on a computer + + + align:start position:0% +problem of characterizing on a computer +any material that you wanted uh the + + align:start position:0% +any material that you wanted uh the + + + align:start position:0% +any material that you wanted uh the +reason why you can't really do that in + + align:start position:0% +reason why you can't really do that in + + + align:start position:0% +reason why you can't really do that in +general and indiscriminate + + align:start position:0% +general and indiscriminate + + + align:start position:0% +general and indiscriminate +indiscriminately um as to do with sort + + align:start position:0% +indiscriminately um as to do with sort + + + align:start position:0% +indiscriminately um as to do with sort +of four + + align:start position:0% +of four + + + align:start position:0% +of four +problems that arises in the approach + + align:start position:0% +problems that arises in the approach + + + align:start position:0% +problems that arises in the approach +that I've mentioned and sort of I've + + align:start position:0% +that I've mentioned and sort of I've + + + align:start position:0% +that I've mentioned and sort of I've +mentioned them here uh I guess in order + + align:start position:0% +mentioned them here uh I guess in order + + + align:start position:0% +mentioned them here uh I guess in order +of + + align:start position:0% +of + + + align:start position:0% +of +importance and uh the first and most + + align:start position:0% +importance and uh the first and most + + + align:start position:0% +importance and uh the first and most +dramatic problem is the one of time + + align:start position:0% +dramatic problem is the one of time + + + align:start position:0% +dramatic problem is the one of time +scales that is atoms move around and + + align:start position:0% +scales that is atoms move around and + + + align:start position:0% +scales that is atoms move around and +vibrate at time scales that are + + align:start position:0% +vibrate at time scales that are + + + align:start position:0% +vibrate at time scales that are +characteristic of atoms that is uh um + + align:start position:0% +characteristic of atoms that is uh um + + + align:start position:0% +characteristic of atoms that is uh um +say in a molecule it will take tens of + + align:start position:0% +say in a molecule it will take tens of + + + align:start position:0% +say in a molecule it will take tens of +ftocs or 100 of ftocs to have a periodic + + align:start position:0% +ftocs or 100 of ftocs to have a periodic + + + align:start position:0% +ftocs or 100 of ftocs to have a periodic +oscillation so these are sort of you + + align:start position:0% +oscillation so these are sort of you + + + align:start position:0% +oscillation so these are sort of you +know uh fto seconds 10 Theus 15 seconds + + align:start position:0% +know uh fto seconds 10 Theus 15 seconds + + + align:start position:0% +know uh fto seconds 10 Theus 15 seconds +is the order of magnitude of the + + align:start position:0% +is the order of magnitude of the + + + align:start position:0% +is the order of magnitude of the +Dynamics of the atoms uh at sort of room + + align:start position:0% +Dynamics of the atoms uh at sort of room + + + align:start position:0% +Dynamics of the atoms uh at sort of room +room temperature now a lot of + + align:start position:0% +room temperature now a lot of + + + align:start position:0% +room temperature now a lot of +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +problems take place into sort of times + + align:start position:0% +problems take place into sort of times + + + align:start position:0% +problems take place into sort of times +of seconds me + + align:start position:0% +of seconds me + + + align:start position:0% +of seconds me +or hours you know sort of a classical + + align:start position:0% +or hours you know sort of a classical + + + align:start position:0% +or hours you know sort of a classical +problem is how a protein folds itself in + + align:start position:0% +problem is how a protein folds itself in + + + align:start position:0% +problem is how a protein folds itself in +its native state and you know this is a + + align:start position:0% +its native state and you know this is a + + + align:start position:0% +its native state and you know this is a +process that can take seconds and so we + + align:start position:0% +process that can take seconds and so we + + + align:start position:0% +process that can take seconds and so we +have really the issue that you know all + + align:start position:0% +have really the issue that you know all + + + align:start position:0% +have really the issue that you know all +our calculation takes place on the time + + align:start position:0% +our calculation takes place on the time + + + align:start position:0% +our calculation takes place on the time +scales of 10 to Theus 15 and often we + + align:start position:0% +scales of 10 to Theus 15 and often we + + + align:start position:0% +scales of 10 to Theus 15 and often we +need to reach physical properties that + + align:start position:0% +need to reach physical properties that + + + align:start position:0% +need to reach physical properties that +are of the order of seconds so we need + + align:start position:0% +are of the order of seconds so we need + + + align:start position:0% +are of the order of seconds so we need +to span 15 order of magnitudes and that + + align:start position:0% +to span 15 order of magnitudes and that + + + align:start position:0% +to span 15 order of magnitudes and that +means that you know if it takes a time x + + align:start position:0% +means that you know if it takes a time x + + + align:start position:0% +means that you know if it takes a time x +to perform one single molecular Dynamic + + align:start position:0% +to perform one single molecular Dynamic + + + align:start position:0% +to perform one single molecular Dynamic +operation we have a 10 to the 15 cost to + + align:start position:0% +operation we have a 10 to the 15 cost to + + + align:start position:0% +operation we have a 10 to the 15 cost to +get to the reasonable time scale for a + + align:start position:0% +get to the reasonable time scale for a + + + align:start position:0% +get to the reasonable time scale for a +lot of microscopic processes and that's + + align:start position:0% +lot of microscopic processes and that's + + + align:start position:0% +lot of microscopic processes and that's +really you know a scale that we can't + + align:start position:0% +really you know a scale that we can't + + + align:start position:0% +really you know a scale that we can't +bridge if we do quantum mechanical + + align:start position:0% +bridge if we do quantum mechanical + + + align:start position:0% +bridge if we do quantum mechanical +simulations you know for small system we + + align:start position:0% +simulations you know for small system we + + + align:start position:0% +simulations you know for small system we +can easily sort of reach the times of 10 + + align:start position:0% +can easily sort of reach the times of 10 + + + align:start position:0% +can easily sort of reach the times of 10 +of Picos seconds or hundreds of Picos + + align:start position:0% +of Picos seconds or hundreds of Picos + + + align:start position:0% +of Picos seconds or hundreds of Picos +seconds if we do classical molecular + + align:start position:0% +seconds if we do classical molecular + + + align:start position:0% +seconds if we do classical molecular +Dynamic simulation we can go maybe three + + align:start position:0% +Dynamic simulation we can go maybe three + + + align:start position:0% +Dynamic simulation we can go maybe three +four five orders of magnitude better and + + align:start position:0% +four five orders of magnitude better and + + + align:start position:0% +four five orders of magnitude better and +so we can sort of start accessing + + align:start position:0% +so we can sort of start accessing + + + align:start position:0% +so we can sort of start accessing +Nan and maybe start hitching um start uh + + align:start position:0% +Nan and maybe start hitching um start uh + + + align:start position:0% +Nan and maybe start hitching um start uh +getting closer towards the microc but + + align:start position:0% +getting closer towards the microc but + + + align:start position:0% +getting closer towards the microc but +there is still an enormous Gap to reach + + align:start position:0% +there is still an enormous Gap to reach + + + align:start position:0% +there is still an enormous Gap to reach +and this is really a difficult problem + + align:start position:0% +and this is really a difficult problem + + + align:start position:0% +and this is really a difficult problem +to overcome because we have sort of + + align:start position:0% +to overcome because we have sort of + + + align:start position:0% +to overcome because we have sort of +Dynamics taking place at different + + align:start position:0% +Dynamics taking place at different + + + align:start position:0% +Dynamics taking place at different +levels we have the say think at a + + align:start position:0% +levels we have the say think at a + + + align:start position:0% +levels we have the say think at a +protein we have the atomic dynamics of + + align:start position:0% +protein we have the atomic dynamics of + + + align:start position:0% +protein we have the atomic dynamics of +atom vibrating around and then we have + + align:start position:0% +atom vibrating around and then we have + + + align:start position:0% +atom vibrating around and then we have +sort of dynamics of subunits sort of + + align:start position:0% +sort of dynamics of subunits sort of + + + align:start position:0% +sort of dynamics of subunits sort of +maybe interacting with the different + + align:start position:0% +maybe interacting with the different + + + align:start position:0% +maybe interacting with the different +amino acids along the chain and then we + + align:start position:0% +amino acids along the chain and then we + + + align:start position:0% +amino acids along the chain and then we +have sort of structural motifs that + + align:start position:0% +have sort of structural motifs that + + + align:start position:0% +have sort of structural motifs that +wants to move around and then maybe you + + align:start position:0% +wants to move around and then maybe you + + + align:start position:0% +wants to move around and then maybe you +know sort of they sort of first coil up + + align:start position:0% +know sort of they sort of first coil up + + + align:start position:0% +know sort of they sort of first coil up +in a certain configuration but that's + + align:start position:0% +in a certain configuration but that's + + + align:start position:0% +in a certain configuration but that's +not really very good and then after a + + align:start position:0% +not really very good and then after a + + + align:start position:0% +not really very good and then after a +while they sort of open up and recoil in + + align:start position:0% +while they sort of open up and recoil in + + + align:start position:0% +while they sort of open up and recoil in +a different configuration and so the + + align:start position:0% +a different configuration and so the + + + align:start position:0% +a different configuration and so the +more sort of you look at your system on + + align:start position:0% +more sort of you look at your system on + + + align:start position:0% +more sort of you look at your system on +larger and larger lens scale the more + + align:start position:0% +larger and larger lens scale the more + + + align:start position:0% +larger and larger lens scale the more +you discover that there are dynamics of + + align:start position:0% +you discover that there are dynamics of + + + align:start position:0% +you discover that there are dynamics of +more and more complex groups that are + + align:start position:0% +more and more complex groups that are + + + align:start position:0% +more and more complex groups that are +slower and slower and integrating from + + align:start position:0% +slower and slower and integrating from + + + align:start position:0% +slower and slower and integrating from +the atomic motion up to the mesos scale + + align:start position:0% +the atomic motion up to the mesos scale + + + align:start position:0% +the atomic motion up to the mesos scale +and the microscopic scale this Dynamics + + align:start position:0% +and the microscopic scale this Dynamics + + + align:start position:0% +and the microscopic scale this Dynamics +is really an impossible possible problem + + align:start position:0% +is really an impossible possible problem + + + align:start position:0% +is really an impossible possible problem +to do by brute force and I would say + + align:start position:0% +to do by brute force and I would say + + + align:start position:0% +to do by brute force and I would say +that you know it's still the conceptual + + align:start position:0% +that you know it's still the conceptual + + + align:start position:0% +that you know it's still the conceptual +problem for which less uh progress has + + align:start position:0% +problem for which less uh progress has + + + align:start position:0% +problem for which less uh progress has +been made it's really the most difficult + + align:start position:0% +been made it's really the most difficult + + + align:start position:0% +been made it's really the most difficult +one and you'll hear a lot of talks + + align:start position:0% +one and you'll hear a lot of talks + + + align:start position:0% +one and you'll hear a lot of talks +nowadays in science about multiscale + + align:start position:0% +nowadays in science about multiscale + + + align:start position:0% +nowadays in science about multiscale +modeling and about bridging time scales + + align:start position:0% +modeling and about bridging time scales + + + align:start position:0% +modeling and about bridging time scales +and it's obviously you know very + + align:start position:0% +and it's obviously you know very + + + align:start position:0% +and it's obviously you know very +important challenge but I still think we + + align:start position:0% +important challenge but I still think we + + + align:start position:0% +important challenge but I still think we +are at the stage in which there are very + + align:start position:0% +are at the stage in which there are very + + + align:start position:0% +are at the stage in which there are very +little so Solutions somehow related to + + align:start position:0% +little so Solutions somehow related to + + + align:start position:0% +little so Solutions somehow related to +the length scale problem to the time + + align:start position:0% +the length scale problem to the time + + + align:start position:0% +the length scale problem to the time +scale problem there is the length scale + + align:start position:0% +scale problem there is the length scale + + + align:start position:0% +scale problem there is the length scale +problem um suppose you want to study a + + align:start position:0% +problem um suppose you want to study a + + + align:start position:0% +problem um suppose you want to study a +system close to a phase transition + + align:start position:0% +system close to a phase transition + + + align:start position:0% +system close to a phase transition +suppose that you want to do you know you + + align:start position:0% +suppose that you want to do you know you + + + align:start position:0% +suppose that you want to do you know you +want to see a gas evaporate you want to + + align:start position:0% +want to see a gas evaporate you want to + + + align:start position:0% +want to see a gas evaporate you want to +study a liquid to Vapor transition uh + + align:start position:0% +study a liquid to Vapor transition uh + + + align:start position:0% +study a liquid to Vapor transition uh +what happens exactly at the temperature + + align:start position:0% +what happens exactly at the temperature + + + align:start position:0% +what happens exactly at the temperature +where the liquid and the vapor are in + + align:start position:0% +where the liquid and the vapor are in + + + align:start position:0% +where the liquid and the vapor are in +equilibrium suppose that you're are + + align:start position:0% +equilibrium suppose that you're are + + + align:start position:0% +equilibrium suppose that you're are +studying you know uh water boiling at + + align:start position:0% +studying you know uh water boiling at + + + align:start position:0% +studying you know uh water boiling at +sort of normal condition it boils at uh + + align:start position:0% +sort of normal condition it boils at uh + + + align:start position:0% +sort of normal condition it boils at uh +373 Kelvin uh and at that + + align:start position:0% +373 Kelvin uh and at that + + + align:start position:0% +373 Kelvin uh and at that +temperature uh why there is a phase + + align:start position:0% +temperature uh why there is a phase + + + align:start position:0% +temperature uh why there is a phase +transition basically because the free + + align:start position:0% +transition basically because the free + + + align:start position:0% +transition basically because the free +energy of the liquid and the free energy + + align:start position:0% +energy of the liquid and the free energy + + + align:start position:0% +energy of the liquid and the free energy +of the gas are the same you go a little + + align:start position:0% +of the gas are the same you go a little + + + align:start position:0% +of the gas are the same you go a little +bit above the temperature the free + + align:start position:0% +bit above the temperature the free + + + align:start position:0% +bit above the temperature the free +energy of the gas is lower so the system + + align:start position:0% +energy of the gas is lower so the system + + + align:start position:0% +energy of the gas is lower so the system +wants to be all gas you go a little bit + + align:start position:0% +wants to be all gas you go a little bit + + + align:start position:0% +wants to be all gas you go a little bit +below the boiling temperature the free + + align:start position:0% +below the boiling temperature the free + + + align:start position:0% +below the boiling temperature the free +energy of the liquid is lower so the + + align:start position:0% +energy of the liquid is lower so the + + + align:start position:0% +energy of the liquid is lower so the +system wants to be all liquid but as you + + align:start position:0% +system wants to be all liquid but as you + + + align:start position:0% +system wants to be all liquid but as you +get closer and closer to the temperature + + align:start position:0% +get closer and closer to the temperature + + + align:start position:0% +get closer and closer to the temperature +these two free energies becomes + + align:start position:0% +these two free energies becomes + + + align:start position:0% +these two free energies becomes +comparable that means that the cost of + + align:start position:0% +comparable that means that the cost of + + + align:start position:0% +comparable that means that the cost of +transforming from liquid to the gas and + + align:start position:0% +transforming from liquid to the gas and + + + align:start position:0% +transforming from liquid to the gas and +from gas to liquid becomes smaller and + + align:start position:0% +from gas to liquid becomes smaller and + + + align:start position:0% +from gas to liquid becomes smaller and +smaller and it is zero at the transition + + align:start position:0% +smaller and it is zero at the transition + + + align:start position:0% +smaller and it is zero at the transition +temperature that means in practice that + + align:start position:0% +temperature that means in practice that + + + align:start position:0% +temperature that means in practice that +since that it doesn't cost anything to + + align:start position:0% +since that it doesn't cost anything to + + + align:start position:0% +since that it doesn't cost anything to +transform from one state to the other + + align:start position:0% +transform from one state to the other + + + align:start position:0% +transform from one state to the other +you have lost all possible length scale + + align:start position:0% +you have lost all possible length scale + + + align:start position:0% +you have lost all possible length scale +because you can nucleate a bubble of gas + + align:start position:0% +because you can nucleate a bubble of gas + + + align:start position:0% +because you can nucleate a bubble of gas +of any size with zero cost so if you + + align:start position:0% +of any size with zero cost so if you + + + align:start position:0% +of any size with zero cost so if you +think at the transformation from a + + align:start position:0% +think at the transformation from a + + + align:start position:0% +think at the transformation from a +liquid to a vapor as the nucleation of + + align:start position:0% +liquid to a vapor as the nucleation of + + + align:start position:0% +liquid to a vapor as the nucleation of +bubble of gas exactly at the temperature + + align:start position:0% +bubble of gas exactly at the temperature + + + align:start position:0% +bubble of gas exactly at the temperature +of the transition that cost has become + + align:start position:0% +of the transition that cost has become + + + align:start position:0% +of the transition that cost has become +zero and we can nucleate bubble of any + + align:start position:0% +zero and we can nucleate bubble of any + + + align:start position:0% +zero and we can nucleate bubble of any +size so the phase transition is a moment + + align:start position:0% +size so the phase transition is a moment + + + align:start position:0% +size so the phase transition is a moment +where we lose lens scales the + + align:start position:0% +where we lose lens scales the + + + align:start position:0% +where we lose lens scales the +fluctuation can have any size and so any + + align:start position:0% +fluctuation can have any size and so any + + + align:start position:0% +fluctuation can have any size and so any +kind of finite simulation will break + + align:start position:0% +kind of finite simulation will break + + + align:start position:0% +kind of finite simulation will break +down because it's really only in the + + align:start position:0% +down because it's really only in the + + + align:start position:0% +down because it's really only in the +infinite system that we represent + + align:start position:0% +infinite system that we represent + + + align:start position:0% +infinite system that we represent +appropriately all this sizes popping up + + align:start position:0% +appropriately all this sizes popping up + + + align:start position:0% +appropriately all this sizes popping up +in our system and so that's why it + + align:start position:0% +in our system and so that's why it + + + align:start position:0% +in our system and so that's why it +becomes very difficult to to study + + align:start position:0% +becomes very difficult to to study + + + align:start position:0% +becomes very difficult to to study +accurately say a boundary at a phase + + align:start position:0% +accurately say a boundary at a phase + + + align:start position:0% +accurately say a boundary at a phase +transition we say that the land scale + + align:start position:0% +transition we say that the land scale + + + align:start position:0% +transition we say that the land scale +start diverging and that's why one needs + + align:start position:0% +start diverging and that's why one needs + + + align:start position:0% +start diverging and that's why one needs +to be careful this problem is not as + + align:start position:0% +to be careful this problem is not as + + + align:start position:0% +to be careful this problem is not as +serious as the problem of time scales uh + + align:start position:0% +serious as the problem of time scales uh + + + align:start position:0% +serious as the problem of time scales uh +but it's still you know one that you + + align:start position:0% +but it's still you know one that you + + + align:start position:0% +but it's still you know one that you +want to um consider very carefully and + + align:start position:0% +want to um consider very carefully and + + + align:start position:0% +want to um consider very carefully and +once you need also to spend some time + + align:start position:0% +once you need also to spend some time + + + align:start position:0% +once you need also to spend some time +thinking actually that is uh often we + + align:start position:0% +thinking actually that is uh often we + + + align:start position:0% +thinking actually that is uh often we +use a periodic boundary condition to + + align:start position:0% +use a periodic boundary condition to + + + align:start position:0% +use a periodic boundary condition to +describe an extent system and so the + + align:start position:0% +describe an extent system and so the + + + align:start position:0% +describe an extent system and so the +question that you always have to ask + + align:start position:0% +question that you always have to ask + + + align:start position:0% +question that you always have to ask +yourself is how large should I make my + + align:start position:0% +yourself is how large should I make my + + + align:start position:0% +yourself is how large should I make my +unit system that is periodically + + align:start position:0% +unit system that is periodically + + + align:start position:0% +unit system that is periodically +repeated before it's really describing + + align:start position:0% +repeated before it's really describing + + + align:start position:0% +repeated before it's really describing +accurately the infinite system that is + + align:start position:0% +accurately the infinite system that is + + + align:start position:0% +accurately the infinite system that is +the goal of my simulation suppose that + + align:start position:0% +the goal of my simulation suppose that + + + align:start position:0% +the goal of my simulation suppose that +you want to study water okay or suppose + + align:start position:0% +you want to study water okay or suppose + + + align:start position:0% +you want to study water okay or suppose +that you want to study any + + align:start position:0% +that you want to study any + + + align:start position:0% +that you want to study any +liquid in principle you want an infinite + + align:start position:0% +liquid in principle you want an infinite + + + align:start position:0% +liquid in principle you want an infinite +system in practice you can deal only + + align:start position:0% +system in practice you can deal only + + + align:start position:0% +system in practice you can deal only +with a finite number of degrees of + + align:start position:0% +with a finite number of degrees of + + + align:start position:0% +with a finite number of degrees of +freedom so the two possibilities that + + align:start position:0% +freedom so the two possibilities that + + + align:start position:0% +freedom so the two possibilities that +you have you could study a droplet of + + align:start position:0% +you have you could study a droplet of + + + align:start position:0% +you have you could study a droplet of +water okay but then obviously uh you + + align:start position:0% +water okay but then obviously uh you + + + align:start position:0% +water okay but then obviously uh you +encounter the problem that when you + + align:start position:0% +encounter the problem that when you + + + align:start position:0% +encounter the problem that when you +study a droplet you have a very large + + align:start position:0% +study a droplet you have a very large + + + align:start position:0% +study a droplet you have a very large +influence coming from the surface effect + + align:start position:0% +influence coming from the surface effect + + + align:start position:0% +influence coming from the surface effect +the droplet is a droplet because of the + + align:start position:0% +the droplet is a droplet because of the + + + align:start position:0% +the droplet is a droplet because of the +surface tension and before reaching the + + align:start position:0% +surface tension and before reaching the + + + align:start position:0% +surface tension and before reaching the +thermodynamic limit of that droplet + + align:start position:0% +thermodynamic limit of that droplet + + + align:start position:0% +thermodynamic limit of that droplet +behaving as a bulk liquid you need + + align:start position:0% +behaving as a bulk liquid you need + + + align:start position:0% +behaving as a bulk liquid you need +really to go to a normal most sizes If + + align:start position:0% +really to go to a normal most sizes If + + + align:start position:0% +really to go to a normal most sizes If +instead you study say the same number of + + align:start position:0% +instead you study say the same number of + + + align:start position:0% +instead you study say the same number of +molecules in periodic boundary + + align:start position:0% +molecules in periodic boundary + + + align:start position:0% +molecules in periodic boundary +conditions you eliminate the presence of + + align:start position:0% +conditions you eliminate the presence of + + + align:start position:0% +conditions you eliminate the presence of +the surface and so you can reach the + + align:start position:0% +the surface and so you can reach the + + + align:start position:0% +the surface and so you can reach the +thermodynamic limit of the system + + align:start position:0% +thermodynamic limit of the system + + + align:start position:0% +thermodynamic limit of the system +behaving as a bulk much faster but still + + align:start position:0% +behaving as a bulk much faster but still + + + align:start position:0% +behaving as a bulk much faster but still +you need to always ask your question is + + align:start position:0% +you need to always ask your question is + + + align:start position:0% +you need to always ask your question is +your simulation cell large enough and + + align:start position:0% +your simulation cell large enough and + + + align:start position:0% +your simulation cell large enough and +there is a size that is large enough and + + align:start position:0% +there is a size that is large enough and + + + align:start position:0% +there is a size that is large enough and +that's the other very important concept + + align:start position:0% +that's the other very important concept + + + align:start position:0% +that's the other very important concept +that is whenever your simulation cell is + + align:start position:0% +that is whenever your simulation cell is + + + align:start position:0% +that is whenever your simulation cell is +so large that the Dynamics of one water + + align:start position:0% +so large that the Dynamics of one water + + + align:start position:0% +so large that the Dynamics of one water +molecule doesn't affect the Dynamics of + + align:start position:0% +molecule doesn't affect the Dynamics of + + + align:start position:0% +molecule doesn't affect the Dynamics of +a water molecule that is far away from + + align:start position:0% +a water molecule that is far away from + + + align:start position:0% +a water molecule that is far away from +your as much as it is its periodic image + + align:start position:0% +your as much as it is its periodic image + + + align:start position:0% +your as much as it is its periodic image +your system has become infinite that is + + align:start position:0% +your system has become infinite that is + + + align:start position:0% +your system has become infinite that is +whenever you are sort of a molecule in a + + align:start position:0% +whenever you are sort of a molecule in a + + + align:start position:0% +whenever you are sort of a molecule in a +liquid you really dynamically interact + + align:start position:0% +liquid you really dynamically interact + + + align:start position:0% +liquid you really dynamically interact +not with every other molecule in the + + align:start position:0% +not with every other molecule in the + + + align:start position:0% +not with every other molecule in the +infinite liquid but only with sort of a + + align:start position:0% +infinite liquid but only with sort of a + + + align:start position:0% +infinite liquid but only with sort of a +sphere of neighbors and you need to + + align:start position:0% +sphere of neighbors and you need to + + + align:start position:0% +sphere of neighbors and you need to +understand how large is that sphere of + + align:start position:0% +understand how large is that sphere of + + + align:start position:0% +understand how large is that sphere of +neighbors because those and only those + + align:start position:0% +neighbors because those and only those + + + align:start position:0% +neighbors because those and only those +are the molecules that affect yourself + + align:start position:0% +are the molecules that affect yourself + + + align:start position:0% +are the molecules that affect yourself +in the center of that sphere and if you + + align:start position:0% +in the center of that sphere and if you + + + align:start position:0% +in the center of that sphere and if you +decide that you know for a a water + + align:start position:0% +decide that you know for a a water + + + align:start position:0% +decide that you know for a a water +molecule at room temperature the sphere + + align:start position:0% +molecule at room temperature the sphere + + + align:start position:0% +molecule at room temperature the sphere +of neighbors with which there is a + + align:start position:0% +of neighbors with which there is a + + + align:start position:0% +of neighbors with which there is a +dynamical interaction as only a radius + + align:start position:0% +dynamical interaction as only a radius + + + align:start position:0% +dynamical interaction as only a radius +of 10 anstrom whenever your unit cell is + + align:start position:0% +of 10 anstrom whenever your unit cell is + + + align:start position:0% +of 10 anstrom whenever your unit cell is +larger is a cube say larger than 20 + + align:start position:0% +larger is a cube say larger than 20 + + + align:start position:0% +larger is a cube say larger than 20 +anrom inside you are studying in + + align:start position:0% +anrom inside you are studying in + + + align:start position:0% +anrom inside you are studying in +practice an infinite system because + + align:start position:0% +practice an infinite system because + + + align:start position:0% +practice an infinite system because +every molecule in that system sees all + + align:start position:0% +every molecule in that system sees all + + + align:start position:0% +every molecule in that system sees all +the independent neighbors that needs to + + align:start position:0% +the independent neighbors that needs to + + + align:start position:0% +the independent neighbors that needs to +see okay so even a simulation with a + + align:start position:0% +see okay so even a simulation with a + + + align:start position:0% +see okay so even a simulation with a +finite number of molecules can reproduce + + align:start position:0% +finite number of molecules can reproduce + + + align:start position:0% +finite number of molecules can reproduce +exactly the behavior of an infinite + + align:start position:0% +exactly the behavior of an infinite + + + align:start position:0% +exactly the behavior of an infinite +system provide that a molecule interacts + + align:start position:0% +system provide that a molecule interacts + + + align:start position:0% +system provide that a molecule interacts +with other independent molecules up to a + + align:start position:0% +with other independent molecules up to a + + + align:start position:0% +with other independent molecules up to a +sort of you know maximum range of + + align:start position:0% +sort of you know maximum range of + + + align:start position:0% +sort of you know maximum range of +dynamical correlation and we actually + + align:start position:0% +dynamical correlation and we actually + + + align:start position:0% +dynamical correlation and we actually +sort of Define this quantity in the + + align:start position:0% +sort of Define this quantity in the + + + align:start position:0% +sort of Define this quantity in the +lecture that follows uh so again lens + + align:start position:0% +lecture that follows uh so again lens + + + align:start position:0% +lecture that follows uh so again lens +scale are another problem uh and a + + align:start position:0% +scale are another problem uh and a + + + align:start position:0% +scale are another problem uh and a +problem in which periodic boundary + + align:start position:0% +problem in which periodic boundary + + + align:start position:0% +problem in which periodic boundary +conditions tend to help a lot but again + + align:start position:0% +conditions tend to help a lot but again + + + align:start position:0% +conditions tend to help a lot but again +suppose that you want to study something + + align:start position:0% +suppose that you want to study something + + + align:start position:0% +suppose that you want to study something +like the strength of a metal well you + + align:start position:0% +like the strength of a metal well you + + + align:start position:0% +like the strength of a metal well you +have now a problem in which a lot of + + align:start position:0% +have now a problem in which a lot of + + + align:start position:0% +have now a problem in which a lot of +lens scale becomes intertwined because + + align:start position:0% +lens scale becomes intertwined because + + + align:start position:0% +lens scale becomes intertwined because +in the strength of a metal uh you know + + align:start position:0% +in the strength of a metal uh you know + + + align:start position:0% +in the strength of a metal uh you know +you might want to consider what is the + + align:start position:0% +you might want to consider what is the + + + align:start position:0% +you might want to consider what is the +dynamic dynamics of impurities that + + align:start position:0% +dynamic dynamics of impurities that + + + align:start position:0% +dynamic dynamics of impurities that +strengthen that metal like if you have + + align:start position:0% +strengthen that metal like if you have + + + align:start position:0% +strengthen that metal like if you have +steel you have carbon atoms in between + + align:start position:0% +steel you have carbon atoms in between + + + align:start position:0% +steel you have carbon atoms in between +the iron and so you need to understand + + align:start position:0% +the iron and so you need to understand + + + align:start position:0% +the iron and so you need to understand +what is the atomic Dynamics but then + + align:start position:0% +what is the atomic Dynamics but then + + + align:start position:0% +what is the atomic Dynamics but then +there will be a dynamics of units on a + + align:start position:0% +there will be a dynamics of units on a + + + align:start position:0% +there will be a dynamics of units on a +larger lens scale because in a metal + + align:start position:0% +larger lens scale because in a metal + + + align:start position:0% +larger lens scale because in a metal +there's going to be this location and + + align:start position:0% +there's going to be this location and + + + align:start position:0% +there's going to be this location and +sleep and glide planes and so there is + + align:start position:0% +sleep and glide planes and so there is + + + align:start position:0% +sleep and glide planes and so there is +coordinated + + align:start position:0% +coordinated + + + align:start position:0% +coordinated +motion of thousands of atoms that you + + align:start position:0% +motion of thousands of atoms that you + + + align:start position:0% +motion of thousands of atoms that you +want to consider and then in reality a + + align:start position:0% +want to consider and then in reality a + + + align:start position:0% +want to consider and then in reality a +real metal is never a crystal but it's + + align:start position:0% +real metal is never a crystal but it's + + + align:start position:0% +real metal is never a crystal but it's +always a poly crystalling material so + + align:start position:0% +always a poly crystalling material so + + + align:start position:0% +always a poly crystalling material so +you have grains and inside that grain + + align:start position:0% +you have grains and inside that grain + + + align:start position:0% +you have grains and inside that grain +you have a consistent ordering of the + + align:start position:0% +you have a consistent ordering of the + + + align:start position:0% +you have a consistent ordering of the +atoms but then grains are mismatched and + + align:start position:0% +atoms but then grains are mismatched and + + + align:start position:0% +atoms but then grains are mismatched and +there are grain boundaries and so you + + align:start position:0% +there are grain boundaries and so you + + + align:start position:0% +there are grain boundaries and so you +have a lot of lens scales to consider if + + align:start position:0% +have a lot of lens scales to consider if + + + align:start position:0% +have a lot of lens scales to consider if +you really want to predict what would be + + align:start position:0% +you really want to predict what would be + + + align:start position:0% +you really want to predict what would be +the mechanical response of a real + + align:start position:0% +the mechanical response of a real + + + align:start position:0% +the mechanical response of a real +system okay so this is the challenge if + + align:start position:0% +system okay so this is the challenge if + + + align:start position:0% +system okay so this is the challenge if +you want number two uh the challenge + + align:start position:0% +you want number two uh the challenge + + + align:start position:0% +you want number two uh the challenge +number three is the one that we have + + align:start position:0% +number three is the one that we have + + + align:start position:0% +number three is the one that we have +sort of described more in detail up to + + align:start position:0% +sort of described more in detail up to + + + align:start position:0% +sort of described more in detail up to +now that is determining how accurate + + align:start position:0% +now that is determining how accurate + + + align:start position:0% +now that is determining how accurate +can be your prediction of the + + align:start position:0% +can be your prediction of the + + + align:start position:0% +can be your prediction of the +interaction between nuclei and you have + + align:start position:0% +interaction between nuclei and you have + + + align:start position:0% +interaction between nuclei and you have +seen everything that you know we could + + align:start position:0% +seen everything that you know we could + + + align:start position:0% +seen everything that you know we could +tell you about empirical potential + + align:start position:0% +tell you about empirical potential + + + align:start position:0% +tell you about empirical potential +quantum mechanical simulations and in + + align:start position:0% +quantum mechanical simulations and in + + + align:start position:0% +quantum mechanical simulations and in +principle even if it's obviously very + + align:start position:0% +principle even if it's obviously very + + + align:start position:0% +principle even if it's obviously very +expensive to make very accurate + + align:start position:0% +expensive to make very accurate + + + align:start position:0% +expensive to make very accurate +prediction of the interaction between + + align:start position:0% +prediction of the interaction between + + + align:start position:0% +prediction of the interaction between +atoms in principle is the less + + align:start position:0% +atoms in principle is the less + + + align:start position:0% +atoms in principle is the less +conceptually challenging of the problems + + align:start position:0% +conceptually challenging of the problems + + + align:start position:0% +conceptually challenging of the problems +I mean we can just you know sort of try + + align:start position:0% +I mean we can just you know sort of try + + + align:start position:0% +I mean we can just you know sort of try +all our sort of electronic structure + + align:start position:0% +all our sort of electronic structure + + + align:start position:0% +all our sort of electronic structure +Methods at will and we can sort of to + + align:start position:0% +Methods at will and we can sort of to + + + align:start position:0% +Methods at will and we can sort of to +try to see how accurate we become and + + align:start position:0% +try to see how accurate we become and + + + align:start position:0% +try to see how accurate we become and +the last challenge that is also not + + align:start position:0% +the last challenge that is also not + + + align:start position:0% +the last challenge that is also not +really a conceptual + + align:start position:0% +really a conceptual + + + align:start position:0% +really a conceptual +challenge uh and sort of you know it can + + align:start position:0% +challenge uh and sort of you know it can + + + align:start position:0% +challenge uh and sort of you know it can +be solved but it's just a very um + + align:start position:0% +be solved but it's just a very um + + + align:start position:0% +be solved but it's just a very um +expensive one to overcome is this one in + + align:start position:0% +expensive one to overcome is this one in + + + align:start position:0% +expensive one to overcome is this one in +which we TR we treat the nuclei as + + align:start position:0% +which we TR we treat the nuclei as + + + align:start position:0% +which we TR we treat the nuclei as +classical as classical particles and + + align:start position:0% +classical as classical particles and + + + align:start position:0% +classical as classical particles and +that's s to be in general very good but + + align:start position:0% +that's s to be in general very good but + + + align:start position:0% +that's s to be in general very good but +it's sort of an approximation that + + align:start position:0% +it's sort of an approximation that + + + align:start position:0% +it's sort of an approximation that +breaks down the more you go towards + + align:start position:0% +breaks down the more you go towards + + + align:start position:0% +breaks down the more you go towards +lighter and lighter nuclei because + + align:start position:0% +lighter and lighter nuclei because + + + align:start position:0% +lighter and lighter nuclei because +remember the BR relation your wavelength + + align:start position:0% +remember the BR relation your wavelength + + + align:start position:0% +remember the BR relation your wavelength +times your momentum is equal to the pl + + align:start position:0% +times your momentum is equal to the pl + + + align:start position:0% +times your momentum is equal to the pl +constant so the lighter you are the + + align:start position:0% +constant so the lighter you are the + + + align:start position:0% +constant so the lighter you are the +smaller your momentum the longer your + + align:start position:0% +smaller your momentum the longer your + + + align:start position:0% +smaller your momentum the longer your +wavelength the more Quantum you become + + align:start position:0% +wavelength the more Quantum you become + + + align:start position:0% +wavelength the more Quantum you become +so something like hydrogen that has a + + align:start position:0% +so something like hydrogen that has a + + + align:start position:0% +so something like hydrogen that has a +nucleus that is just one proton so it's + + align:start position:0% +nucleus that is just one proton so it's + + + align:start position:0% +nucleus that is just one proton so it's +fairly light or it's the lightest of all + + align:start position:0% +fairly light or it's the lightest of all + + + align:start position:0% +fairly light or it's the lightest of all +possible nucle tend to still have a + + align:start position:0% +possible nucle tend to still have a + + + align:start position:0% +possible nucle tend to still have a +significant Quantum properties even at + + align:start position:0% +significant Quantum properties even at + + + align:start position:0% +significant Quantum properties even at +relatively high temperatures you see the + + align:start position:0% +relatively high temperatures you see the + + + align:start position:0% +relatively high temperatures you see the +more you increase the temperature the + + align:start position:0% +more you increase the temperature the + + + align:start position:0% +more you increase the temperature the +more the average momentum of your + + align:start position:0% +more the average momentum of your + + + align:start position:0% +more the average momentum of your +particles becomes and the more sort of + + align:start position:0% +particles becomes and the more sort of + + + align:start position:0% +particles becomes and the more sort of +classical they become but the lower the + + align:start position:0% +classical they become but the lower the + + + align:start position:0% +classical they become but the lower the +temperature the more Quantum they become + + align:start position:0% +temperature the more Quantum they become + + + align:start position:0% +temperature the more Quantum they become +and something like hydrogen is still + + align:start position:0% +and something like hydrogen is still + + + align:start position:0% +and something like hydrogen is still +significantly Quantum at room + + align:start position:0% +significantly Quantum at room + + + align:start position:0% +significantly Quantum at room +temperature and what that does that mean + + align:start position:0% +temperature and what that does that mean + + + align:start position:0% +temperature and what that does that mean +well it means that that particle it's + + align:start position:0% +well it means that that particle it's + + + align:start position:0% +well it means that that particle it's +really a delocalized system that can + + align:start position:0% +really a delocalized system that can + + + align:start position:0% +really a delocalized system that can +actually tunnel through through barrier + + align:start position:0% +actually tunnel through through barrier + + + align:start position:0% +actually tunnel through through barrier +that's if you want one of the important + + align:start position:0% +that's if you want one of the important + + + align:start position:0% +that's if you want one of the important +difference between a particle that + + align:start position:0% +difference between a particle that + + + align:start position:0% +difference between a particle that +behaves according to classical mechanics + + align:start position:0% +behaves according to classical mechanics + + + align:start position:0% +behaves according to classical mechanics +and one that behaves according to + + align:start position:0% +and one that behaves according to + + + align:start position:0% +and one that behaves according to +Quantum Mechanics if you are behaving as + + align:start position:0% +Quantum Mechanics if you are behaving as + + + align:start position:0% +Quantum Mechanics if you are behaving as +a classical particle you need to have + + align:start position:0% +a classical particle you need to have + + + align:start position:0% +a classical particle you need to have +enough kinetic energy to overcome a + + align:start position:0% +enough kinetic energy to overcome a + + + align:start position:0% +enough kinetic energy to overcome a +barrier if you are a skier and you are + + align:start position:0% +barrier if you are a skier and you are + + + align:start position:0% +barrier if you are a skier and you are +in a valley and you want to go in the + + align:start position:0% +in a valley and you want to go in the + + + align:start position:0% +in a valley and you want to go in the +other Valley you need to have enough + + align:start position:0% +other Valley you need to have enough + + + align:start position:0% +other Valley you need to have enough +velocity to be able to overcome the + + align:start position:0% +velocity to be able to overcome the + + + align:start position:0% +velocity to be able to overcome the +mountain if you are a Quantum skier you + + align:start position:0% +mountain if you are a Quantum skier you + + + align:start position:0% +mountain if you are a Quantum skier you +can actually have some finite + + align:start position:0% +can actually have some finite + + + align:start position:0% +can actually have some finite +probability of tunnel through and so + + align:start position:0% +probability of tunnel through and so + + + align:start position:0% +probability of tunnel through and so +there are sort of you know tunneling + + align:start position:0% +there are sort of you know tunneling + + + align:start position:0% +there are sort of you know tunneling +problems that are + + align:start position:0% +problems that are + + + align:start position:0% +problems that are +important not only for hydrogen but + + align:start position:0% +important not only for hydrogen but + + + align:start position:0% +important not only for hydrogen but +sometimes even for much more massive + + align:start position:0% +sometimes even for much more massive + + + align:start position:0% +sometimes even for much more massive +particles or even for groups of + + align:start position:0% +particles or even for groups of + + + align:start position:0% +particles or even for groups of +particles provided that the energy + + align:start position:0% +particles provided that the energy + + + align:start position:0% +particles provided that the energy +barrier that they need to overcome is uh + + align:start position:0% +barrier that they need to overcome is uh + + + align:start position:0% +barrier that they need to overcome is uh +small enough and I've shown you in the + + align:start position:0% +small enough and I've shown you in the + + + align:start position:0% +small enough and I've shown you in the +first Quantum class an example in a PA + + align:start position:0% +first Quantum class an example in a PA + + + align:start position:0% +first Quantum class an example in a PA +of Sky crystal in which we have this + + align:start position:0% +of Sky crystal in which we have this + + + align:start position:0% +of Sky crystal in which we have this +cubic structure with an octal cage of + + align:start position:0% +cubic structure with an octal cage of + + + align:start position:0% +cubic structure with an octal cage of +oxygen that can sort of you know + + align:start position:0% +oxygen that can sort of you know + + + align:start position:0% +oxygen that can sort of you know +configure itself in a ground state that + + align:start position:0% +configure itself in a ground state that + + + align:start position:0% +configure itself in a ground state that +is ferroelectric in which the oxygen + + align:start position:0% +is ferroelectric in which the oxygen + + + align:start position:0% +is ferroelectric in which the oxygen +cage displaces with respect to the sort + + align:start position:0% +cage displaces with respect to the sort + + + align:start position:0% +cage displaces with respect to the sort +of cubic Symmetry and induces a + + align:start position:0% +of cubic Symmetry and induces a + + + align:start position:0% +of cubic Symmetry and induces a +permanent electrical diple in your + + align:start position:0% +permanent electrical diple in your + + + align:start position:0% +permanent electrical diple in your +system well there are certain materials + + align:start position:0% +system well there are certain materials + + + align:start position:0% +system well there are certain materials +that have this structure but uh since + + align:start position:0% +that have this structure but uh since + + + align:start position:0% +that have this structure but uh since +that the octal cage can have roughly six + + align:start position:0% +that the octal cage can have roughly six + + + align:start position:0% +that the octal cage can have roughly six +possible choices on where to move off + + align:start position:0% +possible choices on where to move off + + + align:start position:0% +possible choices on where to move off +site if you decrease the temperature + + align:start position:0% +site if you decrease the temperature + + + align:start position:0% +site if you decrease the temperature +enough the oxygen case will start + + align:start position:0% +enough the oxygen case will start + + + align:start position:0% +enough the oxygen case will start +actually tunneling between all the six + + align:start position:0% +actually tunneling between all the six + + + align:start position:0% +actually tunneling between all the six +possibilities instead of sort of finding + + align:start position:0% +possibilities instead of sort of finding + + + align:start position:0% +possibilities instead of sort of finding +itself at zero temperature in a broken + + align:start position:0% +itself at zero temperature in a broken + + + align:start position:0% +itself at zero temperature in a broken +symmetry configuration in which the + + align:start position:0% +symmetry configuration in which the + + + align:start position:0% +symmetry configuration in which the +oxygen cage has chosen one of those six + + align:start position:0% +oxygen cage has chosen one of those six + + + align:start position:0% +oxygen cage has chosen one of those six +possibilities in reality because of + + align:start position:0% +possibilities in reality because of + + + align:start position:0% +possibilities in reality because of +quantum tunneling it keeps tunneling + + align:start position:0% +quantum tunneling it keeps tunneling + + + align:start position:0% +quantum tunneling it keeps tunneling +between all the six possibilities and on + + align:start position:0% +between all the six possibilities and on + + + align:start position:0% +between all the six possibilities and on +average your system looks cubic and on + + align:start position:0% +average your system looks cubic and on + + + align:start position:0% +average your system looks cubic and on +average you don't have really any Fair + + align:start position:0% +average you don't have really any Fair + + + align:start position:0% +average you don't have really any Fair +electricity but the polarizability of + + align:start position:0% +electricity but the polarizability of + + + align:start position:0% +electricity but the polarizability of +the system is going to be different from + + align:start position:0% +the system is going to be different from + + + align:start position:0% +the system is going to be different from +that one in which the octal cage was + + align:start position:0% +that one in which the octal cage was + + + align:start position:0% +that one in which the octal cage was +sitting squarely in the cube so there is + + align:start position:0% +sitting squarely in the cube so there is + + + align:start position:0% +sitting squarely in the cube so there is +a dialectric response that is different + + align:start position:0% +a dialectric response that is different + + + align:start position:0% +a dialectric response that is different +so there are sort of cases that at the + + align:start position:0% +so there are sort of cases that at the + + + align:start position:0% +so there are sort of cases that at the +end are a sort of you know uh fairly + + align:start position:0% +end are a sort of you know uh fairly + + + align:start position:0% +end are a sort of you know uh fairly +exotic I would say for most application + + align:start position:0% +exotic I would say for most application + + + align:start position:0% +exotic I would say for most application +in which tunneling effects of the nuclei + + align:start position:0% +in which tunneling effects of the nuclei + + + align:start position:0% +in which tunneling effects of the nuclei +could become + + align:start position:0% +could become + + + align:start position:0% +could become +important but there is one other + + align:start position:0% +important but there is one other + + + align:start position:0% +important but there is one other +important consequence that comes from + + align:start position:0% +important consequence that comes from + + + align:start position:0% +important consequence that comes from +quantum mechanics that tends to be + + align:start position:0% +quantum mechanics that tends to be + + + align:start position:0% +quantum mechanics that tends to be +important in a lot of cases and that + + align:start position:0% +important in a lot of cases and that + + + align:start position:0% +important in a lot of cases and that +consequence has to do with the + + align:start position:0% +consequence has to do with the + + + align:start position:0% +consequence has to do with the +quantization of vibrational + + align:start position:0% +quantization of vibrational + + + align:start position:0% +quantization of vibrational +excitations that is if you look at the + + align:start position:0% +excitations that is if you look at the + + + align:start position:0% +excitations that is if you look at the +motion of any system a molecule a solid + + align:start position:0% +motion of any system a molecule a solid + + + align:start position:0% +motion of any system a molecule a solid +In classical terms while that molecule + + align:start position:0% +In classical terms while that molecule + + + align:start position:0% +In classical terms while that molecule +or that solid can have any amount of + + align:start position:0% +or that solid can have any amount of + + + align:start position:0% +or that solid can have any amount of +kinetic energy in a hydrogen molecule + + align:start position:0% +kinetic energy in a hydrogen molecule + + + align:start position:0% +kinetic energy in a hydrogen molecule +the atoms can have zero kinetic energy + + align:start position:0% +the atoms can have zero kinetic energy + + + align:start position:0% +the atoms can have zero kinetic energy +if we treat it classically or they can + + align:start position:0% +if we treat it classically or they can + + + align:start position:0% +if we treat it classically or they can +move just a little bit so have a very + + align:start position:0% +move just a little bit so have a very + + + align:start position:0% +move just a little bit so have a very +minute amount of kinetic energy and we + + align:start position:0% +minute amount of kinetic energy and we + + + align:start position:0% +minute amount of kinetic energy and we +can just increase the kinetic energy + + align:start position:0% +can just increase the kinetic energy + + + align:start position:0% +can just increase the kinetic energy +that those atoms can have at + + align:start position:0% +that those atoms can have at + + + align:start position:0% +that those atoms can have at +will in reality because the system is a + + align:start position:0% +will in reality because the system is a + + + align:start position:0% +will in reality because the system is a +Quantum system uh the vibrational modes + + align:start position:0% +Quantum system uh the vibrational modes + + + align:start position:0% +Quantum system uh the vibrational modes +of a molecule or the vibrational modes + + align:start position:0% +of a molecule or the vibrational modes + + + align:start position:0% +of a molecule or the vibrational modes +of a solid are actually quantized and + + align:start position:0% +of a solid are actually quantized and + + + align:start position:0% +of a solid are actually quantized and +you can't have arbitrary amounts of + + align:start position:0% +you can't have arbitrary amounts of + + + align:start position:0% +you can't have arbitrary amounts of +vibrational energy actually in its + + align:start position:0% +vibrational energy actually in its + + + align:start position:0% +vibrational energy actually in its +Quantum ground state a molecule will not + + align:start position:0% +Quantum ground state a molecule will not + + + align:start position:0% +Quantum ground state a molecule will not +be at rest but it will be in what is + + align:start position:0% +be at rest but it will be in what is + + + align:start position:0% +be at rest but it will be in what is +called the zero point Motion state that + + align:start position:0% +called the zero point Motion state that + + + align:start position:0% +called the zero point Motion state that +is what is the quantum mechanical ground + + align:start position:0% +is what is the quantum mechanical ground + + + align:start position:0% +is what is the quantum mechanical ground +state you can think at the analogy with + + align:start position:0% +state you can think at the analogy with + + + align:start position:0% +state you can think at the analogy with +the stability of the atoms uh in its + + align:start position:0% +the stability of the atoms uh in its + + + align:start position:0% +the stability of the atoms uh in its +ground state the electron around the + + align:start position:0% +ground state the electron around the + + + align:start position:0% +ground state the electron around the +proton is not collapsing onto the proton + + align:start position:0% +proton is not collapsing onto the proton + + + align:start position:0% +proton is not collapsing onto the proton +because of the cumic repulsion if the + + align:start position:0% +because of the cumic repulsion if the + + + align:start position:0% +because of the cumic repulsion if the +electron was a classical particle it + + align:start position:0% +electron was a classical particle it + + + align:start position:0% +electron was a classical particle it +would collapse on the nucleus and the + + align:start position:0% +would collapse on the nucleus and the + + + align:start position:0% +would collapse on the nucleus and the +hydrogen atom would be just a proton and + + align:start position:0% +hydrogen atom would be just a proton and + + + align:start position:0% +hydrogen atom would be just a proton and +an electron sitting in the same place + + align:start position:0% +an electron sitting in the same place + + + align:start position:0% +an electron sitting in the same place +but because the electron is quantum it + + align:start position:0% +but because the electron is quantum it + + + align:start position:0% +but because the electron is quantum it +can't really collapse and its lowest + + align:start position:0% +can't really collapse and its lowest + + + align:start position:0% +can't really collapse and its lowest +energy sta is a sta that is you know the + + align:start position:0% +energy sta is a sta that is you know the + + + align:start position:0% +energy sta is a sta that is you know the +1s orbit for the high hydrogen in which + + align:start position:0% +1s orbit for the high hydrogen in which + + + align:start position:0% +1s orbit for the high hydrogen in which +the electron is around that atom but + + align:start position:0% +the electron is around that atom but + + + align:start position:0% +the electron is around that atom but +doesn't collapse onto it and the + + align:start position:0% +doesn't collapse onto it and the + + + align:start position:0% +doesn't collapse onto it and the +excitation of that electron to the next + + align:start position:0% +excitation of that electron to the next + + + align:start position:0% +excitation of that electron to the next +energy state is a quantized excitation + + align:start position:0% +energy state is a quantized excitation + + + align:start position:0% +energy state is a quantized excitation +you can't go to a level of 1 s that has + + align:start position:0% +you can't go to a level of 1 s that has + + + align:start position:0% +you can't go to a level of 1 s that has +an energy for the hydrogen of minus one + + align:start position:0% +an energy for the hydrogen of minus one + + + align:start position:0% +an energy for the hydrogen of minus one +redberg to another state that has energy + + align:start position:0% +redberg to another state that has energy + + + align:start position:0% +redberg to another state that has energy +minus 99 orus 98 or sort of any kind of + + align:start position:0% +minus 99 orus 98 or sort of any kind of + + + align:start position:0% +minus 99 orus 98 or sort of any kind of +amount the next state in which the + + align:start position:0% +amount the next state in which the + + + align:start position:0% +amount the next state in which the +electron can live is a state that has an + + align:start position:0% +electron can live is a state that has an + + + align:start position:0% +electron can live is a state that has an +energy of Min - 1/4 and then minus 1 9th + + align:start position:0% +energy of Min - 1/4 and then minus 1 9th + + + align:start position:0% +energy of Min - 1/4 and then minus 1 9th +and so on and so forth uh the same thing + + align:start position:0% +and so on and so forth uh the same thing + + + align:start position:0% +and so on and so forth uh the same thing +happens for the vibrational level of + + align:start position:0% +happens for the vibrational level of + + + align:start position:0% +happens for the vibrational level of +molecules okay a Quantum molecule at + + align:start position:0% +molecules okay a Quantum molecule at + + + align:start position:0% +molecules okay a Quantum molecule at +sort of you know in its ground state is + + align:start position:0% +sort of you know in its ground state is + + + align:start position:0% +sort of you know in its ground state is +not in a state where the atoms do not + + align:start position:0% +not in a state where the atoms do not + + + align:start position:0% +not in a state where the atoms do not +move but it's in a state where the atoms + + align:start position:0% +move but it's in a state where the atoms + + + align:start position:0% +move but it's in a state where the atoms +have a certain amount of quantum kinetic + + align:start position:0% +have a certain amount of quantum kinetic + + + align:start position:0% +have a certain amount of quantum kinetic +energy and it's in its state called 0 + + align:start position:0% +energy and it's in its state called 0 + + + align:start position:0% +energy and it's in its state called 0 +point motion and if you want to increase + + align:start position:0% +point motion and if you want to increase + + + align:start position:0% +point motion and if you want to increase +the kinetic energy of this molecule you + + align:start position:0% +the kinetic energy of this molecule you + + + align:start position:0% +the kinetic energy of this molecule you +can't do it continuously there is a + + align:start position:0% +can't do it continuously there is a + + + align:start position:0% +can't do it continuously there is a +quantized gap so you need to provide + + align:start position:0% +quantized gap so you need to provide + + + align:start position:0% +quantized gap so you need to provide +enough energy to heat up the system to + + align:start position:0% +enough energy to heat up the system to + + + align:start position:0% +enough energy to heat up the system to +the next state and then to the next + + align:start position:0% +the next state and then to the next + + + align:start position:0% +the next state and then to the next +state and then to the next state and + + align:start position:0% +state and then to the next state and + + + align:start position:0% +state and then to the next state and +that if you think um affects deeply how + + align:start position:0% +that if you think um affects deeply how + + + align:start position:0% +that if you think um affects deeply how +you are going to heat up a system that + + align:start position:0% +you are going to heat up a system that + + + align:start position:0% +you are going to heat up a system that +is if you look at the specific heat of a + + align:start position:0% +is if you look at the specific heat of a + + + align:start position:0% +is if you look at the specific heat of a +solid that is basically the quantity + + align:start position:0% +solid that is basically the quantity + + + align:start position:0% +solid that is basically the quantity +that tells you how much heat this system + + align:start position:0% +that tells you how much heat this system + + + align:start position:0% +that tells you how much heat this system +is going to be able to take and you look + + align:start position:0% +is going to be able to take and you look + + + align:start position:0% +is going to be able to take and you look +at you know what happens at very low + + align:start position:0% +at you know what happens at very low + + + align:start position:0% +at you know what happens at very low +temperature you discover that actually + + align:start position:0% +temperature you discover that actually + + + align:start position:0% +temperature you discover that actually +the system is almost unable to take any + + align:start position:0% +the system is almost unable to take any + + + align:start position:0% +the system is almost unable to take any +heat because all the vibrational + + align:start position:0% +heat because all the vibrational + + + align:start position:0% +heat because all the vibrational +excitation are much larger than the + + align:start position:0% +excitation are much larger than the + + + align:start position:0% +excitation are much larger than the +average amount of kinetic energy that + + align:start position:0% +average amount of kinetic energy that + + + align:start position:0% +average amount of kinetic energy that +you have if you are sort of looking at + + align:start position:0% +you have if you are sort of looking at + + + align:start position:0% +you have if you are sort of looking at +you know what it takes to bring + + align:start position:0% +you know what it takes to bring + + + align:start position:0% +you know what it takes to bring +something from 1 C to 2 Kevin okay but + + align:start position:0% +something from 1 C to 2 Kevin okay but + + + align:start position:0% +something from 1 C to 2 Kevin okay but +this is still relevant if you have you + + align:start position:0% +this is still relevant if you have you + + + align:start position:0% +this is still relevant if you have you +know a system like water even at 300 + + align:start position:0% +know a system like water even at 300 + + + align:start position:0% +know a system like water even at 300 +Kelvin in water say at 300 Kelvin what + + align:start position:0% +Kelvin in water say at 300 Kelvin what + + + align:start position:0% +Kelvin in water say at 300 Kelvin what +you have is you have this water + + align:start position:0% +you have is you have this water + + + align:start position:0% +you have is you have this water +molecules remember what you have you + + align:start position:0% +molecules remember what you have you + + + align:start position:0% +molecules remember what you have you +oxygen hydrogen and hydrogen and you + + align:start position:0% +oxygen hydrogen and hydrogen and you + + + align:start position:0% +oxygen hydrogen and hydrogen and you +know the modes of vibration of these + + align:start position:0% +know the modes of vibration of these + + + align:start position:0% +know the modes of vibration of these +molecules are stretching modes of the + + align:start position:0% +molecules are stretching modes of the + + + align:start position:0% +molecules are stretching modes of the +hydrogens and then there are sort of + + align:start position:0% +hydrogens and then there are sort of + + + align:start position:0% +hydrogens and then there are sort of +scissor like models in which the two + + align:start position:0% +scissor like models in which the two + + + align:start position:0% +scissor like models in which the two +bonds do this and then these are sort of + + align:start position:0% +bonds do this and then these are sort of + + + align:start position:0% +bonds do this and then these are sort of +intramolecular modes just sort of + + align:start position:0% +intramolecular modes just sort of + + + align:start position:0% +intramolecular modes just sort of +relevant to one molecule and then there + + align:start position:0% +relevant to one molecule and then there + + + align:start position:0% +relevant to one molecule and then there +are sort of all the molecules + + align:start position:0% +are sort of all the molecules + + + align:start position:0% +are sort of all the molecules +interacting well at room temperature all + + align:start position:0% +interacting well at room temperature all + + + align:start position:0% +interacting well at room temperature all +the internal modes of the molecule the + + align:start position:0% +the internal modes of the molecule the + + + align:start position:0% +the internal modes of the molecule the +stretching and the scissor modes uh have + + align:start position:0% +stretching and the scissor modes uh have + + + align:start position:0% +stretching and the scissor modes uh have +so much vibrational energy in their + + align:start position:0% +so much vibrational energy in their + + + align:start position:0% +so much vibrational energy in their +ground state that it's almost impossible + + align:start position:0% +ground state that it's almost impossible + + + align:start position:0% +ground state that it's almost impossible +to excite them to the next vibrational + + align:start position:0% +to excite them to the next vibrational + + + align:start position:0% +to excite them to the next vibrational +state with the average temperature that + + align:start position:0% +state with the average temperature that + + + align:start position:0% +state with the average temperature that +you have at 300 Kelvin so even a system + + align:start position:0% +you have at 300 Kelvin so even a system + + + align:start position:0% +you have at 300 Kelvin so even a system +as fundamental as water is really a + + align:start position:0% +as fundamental as water is really a + + + align:start position:0% +as fundamental as water is really a +hybrid behavior in which the vibrational + + align:start position:0% +hybrid behavior in which the vibrational + + + align:start position:0% +hybrid behavior in which the vibrational +interaction between + + align:start position:0% +interaction between + + + align:start position:0% +interaction between +molecules uh can actually be populated + + align:start position:0% +molecules uh can actually be populated + + + align:start position:0% +molecules uh can actually be populated +arbitrarily by the temperature that is + + align:start position:0% +arbitrarily by the temperature that is + + + align:start position:0% +arbitrarily by the temperature that is +surrounding you but it's almost + + align:start position:0% +surrounding you but it's almost + + + align:start position:0% +surrounding you but it's almost +impossible to excite a molecule from a + + align:start position:0% +impossible to excite a molecule from a + + + align:start position:0% +impossible to excite a molecule from a +sort of zero point stretching motion to + + align:start position:0% +sort of zero point stretching motion to + + + align:start position:0% +sort of zero point stretching motion to +the next one and so say the specific + + align:start position:0% +the next one and so say the specific + + + align:start position:0% +the next one and so say the specific +heat of water will be slightly exotic + + align:start position:0% +heat of water will be slightly exotic + + + align:start position:0% +heat of water will be slightly exotic +because really part of its vibration are + + align:start position:0% +because really part of its vibration are + + + align:start position:0% +because really part of its vibration are +quantized and so there are a number of + + align:start position:0% +quantized and so there are a number of + + + align:start position:0% +quantized and so there are a number of +cases in which this classical nuclear + + align:start position:0% +cases in which this classical nuclear + + + align:start position:0% +cases in which this classical nuclear +approximation uh sort of is not is not + + align:start position:0% +approximation uh sort of is not is not + + + align:start position:0% +approximation uh sort of is not is not +exact and luckily they can be studied + + align:start position:0% +exact and luckily they can be studied + + + align:start position:0% +exact and luckily they can be studied +with sort of specific techniques that + + align:start position:0% +with sort of specific techniques that + + + align:start position:0% +with sort of specific techniques that +we'll see in some of the later + + align:start position:0% +we'll see in some of the later + + + align:start position:0% +we'll see in some of the later +application class during this course but + + align:start position:0% +application class during this course but + + + align:start position:0% +application class during this course but +so remember this if there is one thing + + align:start position:0% +so remember this if there is one thing + + + align:start position:0% +so remember this if there is one thing +that you want to remember about the + + align:start position:0% +that you want to remember about the + + + align:start position:0% +that you want to remember about the +behavior of nucle that these vibrational + + align:start position:0% +behavior of nucle that these vibrational + + + align:start position:0% +behavior of nucle that these vibrational +excitation are quantized and we actually + + align:start position:0% +excitation are quantized and we actually + + + align:start position:0% +excitation are quantized and we actually +see this quantization in physical + + align:start position:0% +see this quantization in physical + + + align:start position:0% +see this quantization in physical +properties like the specific like the + + align:start position:0% +properties like the specific like the + + + align:start position:0% +properties like the specific like the +specific + + align:start position:0% +specific + + + align:start position:0% +specific +heat okay so let's + + align:start position:0% +heat okay so let's + + + align:start position:0% +heat okay so let's +discuss uh the + + align:start position:0% +discuss uh the + + + align:start position:0% +discuss uh the +first of the Poss possible application + + align:start position:0% +first of the Poss possible application + + + align:start position:0% +first of the Poss possible application +of molecular dynamics that that I have + + align:start position:0% +of molecular dynamics that that I have + + + align:start position:0% +of molecular dynamics that that I have +mentioned and that using molecular + + align:start position:0% +mentioned and that using molecular + + + align:start position:0% +mentioned and that using molecular +Dynamics to really calculate average + + align:start position:0% +Dynamics to really calculate average + + + align:start position:0% +Dynamics to really calculate average +properties of a system at finite + + align:start position:0% +properties of a system at finite + + + align:start position:0% +properties of a system at finite +temperature and what I written here is + + align:start position:0% +temperature and what I written here is + + + align:start position:0% +temperature and what I written here is +really sort of you know the summary of + + align:start position:0% +really sort of you know the summary of + + + align:start position:0% +really sort of you know the summary of +statistical mechanics that is what if + + align:start position:0% +statistical mechanics that is what if + + + align:start position:0% +statistical mechanics that is what if +you want bolman would tell you you have + + align:start position:0% +you want bolman would tell you you have + + + align:start position:0% +you want bolman would tell you you have +a dynamical system that is described by + + align:start position:0% +a dynamical system that is described by + + + align:start position:0% +a dynamical system that is described by +this point moving around in Phase space + + align:start position:0% +this point moving around in Phase space + + + align:start position:0% +this point moving around in Phase space +okay so with a certain you know possible + + align:start position:0% +okay so with a certain you know possible + + + align:start position:0% +okay so with a certain you know possible +set of position and with a certain + + align:start position:0% +set of position and with a certain + + + align:start position:0% +set of position and with a certain +possible set of momenta and suppose that + + align:start position:0% +possible set of momenta and suppose that + + + align:start position:0% +possible set of momenta and suppose that +we want to calculate I say what is an + + align:start position:0% +we want to calculate I say what is an + + + align:start position:0% +we want to calculate I say what is an +average property at a certain + + align:start position:0% +average property at a certain + + + align:start position:0% +average property at a certain +temperature and we call that property a + + align:start position:0% +temperature and we call that property a + + + align:start position:0% +temperature and we call that property a +it could be the latis parameter of the + + align:start position:0% +it could be the latis parameter of the + + + align:start position:0% +it could be the latis parameter of the +system you have all this or it could be + + align:start position:0% +system you have all this or it could be + + + align:start position:0% +system you have all this or it could be +the diameter say it's even simpler of + + align:start position:0% +the diameter say it's even simpler of + + + align:start position:0% +the diameter say it's even simpler of +your water bubble okay you have this + + align:start position:0% +your water bubble okay you have this + + + align:start position:0% +your water bubble okay you have this +water bubble and you want to see what is + + align:start position:0% +water bubble and you want to see what is + + + align:start position:0% +water bubble and you want to see what is +the diameter of this water Bubble at a + + align:start position:0% +the diameter of this water Bubble at a + + + align:start position:0% +the diameter of this water Bubble at a +certain temperature and this diameter is + + align:start position:0% +certain temperature and this diameter is + + + align:start position:0% +certain temperature and this diameter is +going to increase with temperature and + + align:start position:0% +going to increase with temperature and + + + align:start position:0% +going to increase with temperature and +what you do you just let this system + + align:start position:0% +what you do you just let this system + + + align:start position:0% +what you do you just let this system +evolve and during its Evolution you keep + + align:start position:0% +evolve and during its Evolution you keep + + + align:start position:0% +evolve and during its Evolution you keep +measuring what is its diameter and you + + align:start position:0% +measuring what is its diameter and you + + + align:start position:0% +measuring what is its diameter and you +let this evolve a lot and you measure + + align:start position:0% +let this evolve a lot and you measure + + + align:start position:0% +let this evolve a lot and you measure +what is it's its width well the way + + align:start position:0% +what is it's its width well the way + + + align:start position:0% +what is it's its width well the way +boltman would set this problem is say we + + align:start position:0% +boltman would set this problem is say we + + + align:start position:0% +boltman would set this problem is say we +really need to integrate over all + + align:start position:0% +really need to integrate over all + + + align:start position:0% +really need to integrate over all +possible configuration ation of the + + align:start position:0% +possible configuration ation of the + + + align:start position:0% +possible configuration ation of the +system that is we need to go through all + + align:start position:0% +system that is we need to go through all + + + align:start position:0% +system that is we need to go through all +possible configuration of the system + + align:start position:0% +possible configuration of the system + + + align:start position:0% +possible configuration of the system +that is we need to integrate over the + + align:start position:0% +that is we need to integrate over the + + + align:start position:0% +that is we need to integrate over the +full phase space and for every possible + + align:start position:0% +full phase space and for every possible + + + align:start position:0% +full phase space and for every possible +point in Phase space we need to + + align:start position:0% +point in Phase space we need to + + + align:start position:0% +point in Phase space we need to +calculate the diameter of my water + + align:start position:0% +calculate the diameter of my water + + + align:start position:0% +calculate the diameter of my water +bubble and then we need to sort of take + + align:start position:0% +bubble and then we need to sort of take + + + align:start position:0% +bubble and then we need to sort of take +into account what is the probability of + + align:start position:0% +into account what is the probability of + + + align:start position:0% +into account what is the probability of +being in that configuration and if you + + align:start position:0% +being in that configuration and if you + + + align:start position:0% +being in that configuration and if you +are in a system at a constant + + align:start position:0% +are in a system at a constant + + + align:start position:0% +are in a system at a constant +temperature the probability of finding + + align:start position:0% +temperature the probability of finding + + + align:start position:0% +temperature the probability of finding +yourself at a given temperature is given + + align:start position:0% +yourself at a given temperature is given + + + align:start position:0% +yourself at a given temperature is given +by exponential of minus beta is just one + + align:start position:0% +by exponential of minus beta is just one + + + align:start position:0% +by exponential of minus beta is just one +over the boltzman constant times the + + align:start position:0% +over the boltzman constant times the + + + align:start position:0% +over the boltzman constant times the +temperature times the energy that means + + align:start position:0% +temperature times the energy that means + + + align:start position:0% +temperature times the energy that means +that + + align:start position:0% +that + + + align:start position:0% +that +configuration that have a high internal + + align:start position:0% +configuration that have a high internal + + + align:start position:0% +configuration that have a high internal +energy are very unlikely and + + align:start position:0% +energy are very unlikely and + + + align:start position:0% +energy are very unlikely and +configuration that have low energy are + + align:start position:0% +configuration that have low energy are + + + align:start position:0% +configuration that have low energy are +more likely to the point that if the + + align:start position:0% +more likely to the point that if the + + + align:start position:0% +more likely to the point that if the +temperature is zero that is this beta is + + align:start position:0% +temperature is zero that is this beta is + + + align:start position:0% +temperature is zero that is this beta is +diverging to Infinity only the lowest + + align:start position:0% +diverging to Infinity only the lowest + + + align:start position:0% +diverging to Infinity only the lowest +energy configuration possible is + + align:start position:0% +energy configuration possible is + + + align:start position:0% +energy configuration possible is +represented but so this is the + + align:start position:0% +represented but so this is the + + + align:start position:0% +represented but so this is the +statistical mechanic points to calculate + + align:start position:0% +statistical mechanic points to calculate + + + align:start position:0% +statistical mechanic points to calculate +an average quantity at a finite + + align:start position:0% +an average quantity at a finite + + + align:start position:0% +an average quantity at a finite +temperature we need to sum over all + + align:start position:0% +temperature we need to sum over all + + + align:start position:0% +temperature we need to sum over all +possible configuration in space and + + align:start position:0% +possible configuration in space and + + + align:start position:0% +possible configuration in space and +momentum for each possible rmp + + align:start position:0% +momentum for each possible rmp + + + align:start position:0% +momentum for each possible rmp +configuration we'll have a certain value + + align:start position:0% +configuration we'll have a certain value + + + align:start position:0% +configuration we'll have a certain value +of the diameter of that bubble we weigh + + align:start position:0% +of the diameter of that bubble we weigh + + + align:start position:0% +of the diameter of that bubble we weigh +that with the statistical weight + + align:start position:0% +that with the statistical weight + + + align:start position:0% +that with the statistical weight +of that configuration and we actually + + align:start position:0% +of that configuration and we actually + + + align:start position:0% +of that configuration and we actually +normalize this expectation value and + + align:start position:0% +normalize this expectation value and + + + align:start position:0% +normalize this expectation value and +this is what we obtain so if for a + + align:start position:0% +this is what we obtain so if for a + + + align:start position:0% +this is what we obtain so if for a +moment you think at a facee space that + + align:start position:0% +moment you think at a facee space that + + + align:start position:0% +moment you think at a facee space that +is + + align:start position:0% +is + + + align:start position:0% +is +two-dimensional and you know in this + + align:start position:0% +two-dimensional and you know in this + + + align:start position:0% +two-dimensional and you know in this +Square we represent all the possible + + align:start position:0% +Square we represent all the possible + + + align:start position:0% +Square we represent all the possible +position and velocity of our system uh + + align:start position:0% +position and velocity of our system uh + + + align:start position:0% +position and velocity of our system uh +what boltzman tells us is that for every + + align:start position:0% +what boltzman tells us is that for every + + + align:start position:0% +what boltzman tells us is that for every +possible point we will have a certain + + align:start position:0% +possible point we will have a certain + + + align:start position:0% +possible point we will have a certain +value of a and the sum of over all the + + align:start position:0% +value of a and the sum of over all the + + + align:start position:0% +value of a and the sum of over all the +possible value of a weighed with the + + align:start position:0% +possible value of a weighed with the + + + align:start position:0% +possible value of a weighed with the +sort of probability of finding them + + align:start position:0% +sort of probability of finding them + + + align:start position:0% +sort of probability of finding them +gives us the expectation value and so + + align:start position:0% +gives us the expectation value and so + + + align:start position:0% +gives us the expectation value and so +what you really need to do is an + + align:start position:0% +what you really need to do is an + + + align:start position:0% +what you really need to do is an +integral over all space of this and this + + align:start position:0% +integral over all space of this and this + + + align:start position:0% +integral over all space of this and this +the cost of these + + align:start position:0% +the cost of these + + + align:start position:0% +the cost of these +integrals diverges as the number of + + align:start position:0% +integrals diverges as the number of + + + align:start position:0% +integrals diverges as the number of +Dimension diverges because again every + + align:start position:0% +Dimension diverges because again every + + + align:start position:0% +Dimension diverges because again every +time we + + align:start position:0% +time we + + + align:start position:0% +time we +increase you know the size of the system + + align:start position:0% +increase you know the size of the system + + + align:start position:0% +increase you know the size of the system +by one particle we have six more + + align:start position:0% +by one particle we have six more + + + align:start position:0% +by one particle we have six more +Dimension over which to integrate and + + align:start position:0% +Dimension over which to integrate and + + + align:start position:0% +Dimension over which to integrate and +again if you think that you know sort of + + align:start position:0% +again if you think that you know sort of + + + align:start position:0% +again if you think that you know sort of +we do this just by numerical integration + + align:start position:0% +we do this just by numerical integration + + + align:start position:0% +we do this just by numerical integration +by taking points on a grid and maybe we + + align:start position:0% +by taking points on a grid and maybe we + + + align:start position:0% +by taking points on a grid and maybe we +just discretize our system with 10 + + align:start position:0% +just discretize our system with 10 + + + align:start position:0% +just discretize our system with 10 +points along one dimension every time + + align:start position:0% +points along one dimension every time + + + align:start position:0% +points along one dimension every time +you add a particle you have 10 to the + + align:start position:0% +you add a particle you have 10 to the + + + align:start position:0% +you add a particle you have 10 to the +six points that multiplier system so + + align:start position:0% +six points that multiplier system so + + + align:start position:0% +six points that multiplier system so +this this quantity explodes the point of + + align:start position:0% +this this quantity explodes the point of + + + align:start position:0% +this this quantity explodes the point of +view of molecular Dynamics is different + + align:start position:0% +view of molecular Dynamics is different + + + align:start position:0% +view of molecular Dynamics is different +what we say is that well let's just let + + align:start position:0% +what we say is that well let's just let + + + align:start position:0% +what we say is that well let's just let +this system evolve let this system + + align:start position:0% +this system evolve let this system + + + align:start position:0% +this system evolve let this system +evolve in time and let it evolve at a + + align:start position:0% +evolve in time and let it evolve at a + + + align:start position:0% +evolve in time and let it evolve at a +constant temperature and so now our + + align:start position:0% +constant temperature and so now our + + + align:start position:0% +constant temperature and so now our +point in Phase space is going you know + + align:start position:0% +point in Phase space is going you know + + + align:start position:0% +point in Phase space is going you know +to go around following a + + align:start position:0% +to go around following a + + + align:start position:0% +to go around following a +trajectory and if we let it go around + + align:start position:0% +trajectory and if we let it go around + + + align:start position:0% +trajectory and if we let it go around +sort of long enough it will spend more + + align:start position:0% +sort of long enough it will spend more + + + align:start position:0% +sort of long enough it will spend more +time in the parts of phas space that are + + align:start position:0% +time in the parts of phas space that are + + + align:start position:0% +time in the parts of phas space that are +more favorite the one that are sort of + + align:start position:0% +more favorite the one that are sort of + + + align:start position:0% +more favorite the one that are sort of +more likely according to the boltman + + align:start position:0% +more likely according to the boltman + + + align:start position:0% +more likely according to the boltman +factor and so if our Evolution really is + + align:start position:0% +factor and so if our Evolution really is + + + align:start position:0% +factor and so if our Evolution really is +distributed in the trajectory according + + align:start position:0% +distributed in the trajectory according + + + align:start position:0% +distributed in the trajectory according +to this uh um thermodynamical weight + + align:start position:0% +to this uh um thermodynamical weight + + + align:start position:0% +to this uh um thermodynamical weight +thermodynamical Factor then our + + align:start position:0% +thermodynamical Factor then our + + + align:start position:0% +thermodynamical Factor then our +expectation value the thermodynamical + + align:start position:0% +expectation value the thermodynamical + + + align:start position:0% +expectation value the thermodynamical +average for our observable a is just + + align:start position:0% +average for our observable a is just + + + align:start position:0% +average for our observable a is just +trivial obtain by integrating over the + + align:start position:0% +trivial obtain by integrating over the + + + align:start position:0% +trivial obtain by integrating over the +rectories all the values of a that is + + align:start position:0% +rectories all the values of a that is + + + align:start position:0% +rectories all the values of a that is +what I was saying before if you want to + + align:start position:0% +what I was saying before if you want to + + + align:start position:0% +what I was saying before if you want to +calculate the diameter of your bubble uh + + align:start position:0% +calculate the diameter of your bubble uh + + + align:start position:0% +calculate the diameter of your bubble uh +what you do in the molecular Dynamic + + align:start position:0% +what you do in the molecular Dynamic + + + align:start position:0% +what you do in the molecular Dynamic +sense you just let the bubble evolve + + align:start position:0% +sense you just let the bubble evolve + + + align:start position:0% +sense you just let the bubble evolve +according to the equation of motion at a + + align:start position:0% +according to the equation of motion at a + + + align:start position:0% +according to the equation of motion at a +constant temperature and you keep + + align:start position:0% +constant temperature and you keep + + + align:start position:0% +constant temperature and you keep +monitoring its diameter and you will see + + align:start position:0% +monitoring its diameter and you will see + + + align:start position:0% +monitoring its diameter and you will see +that that diameter will have an average + + align:start position:0% +that that diameter will have an average + + + align:start position:0% +that that diameter will have an average +and that this is a much more efficient + + align:start position:0% +and that this is a much more efficient + + + align:start position:0% +and that this is a much more efficient +way than considering all possible + + align:start position:0% +way than considering all possible + + + align:start position:0% +way than considering all possible +configuration of the bubble weighing + + align:start position:0% +configuration of the bubble weighing + + + align:start position:0% +configuration of the bubble weighing +them with how expensive that + + align:start position:0% +them with how expensive that + + + align:start position:0% +them with how expensive that +configuration is and sort of you know + + align:start position:0% +configuration is and sort of you know + + + align:start position:0% +configuration is and sort of you know +doing it for all the possible + + align:start position:0% +doing it for all the possible + + + align:start position:0% +doing it for all the possible +configuration the molecular Dynamic + + align:start position:0% +configuration the molecular Dynamic + + + align:start position:0% +configuration the molecular Dynamic +algorithm automatically if you want keep + + align:start position:0% +algorithm automatically if you want keep + + + align:start position:0% +algorithm automatically if you want keep +spanning the most likely configurations + + align:start position:0% +spanning the most likely configurations + + + align:start position:0% +spanning the most likely configurations +and so it does for you the job of sort + + align:start position:0% +and so it does for you the job of sort + + + align:start position:0% +and so it does for you the job of sort +of you know going in the place where + + align:start position:0% +of you know going in the place where + + + align:start position:0% +of you know going in the place where +it's most likely to be um so in order to + + align:start position:0% +it's most likely to be um so in order to + + + align:start position:0% +it's most likely to be um so in order to +calculate emble average we can actually + + align:start position:0% +calculate emble average we can actually + + + align:start position:0% +calculate emble average we can actually +transform our problem into integration + + align:start position:0% +transform our problem into integration + + + align:start position:0% +transform our problem into integration +over a trajectory and that is almost + + align:start position:0% +over a trajectory and that is almost + + + align:start position:0% +over a trajectory and that is almost +always doable under what is called the + + align:start position:0% +always doable under what is called the + + + align:start position:0% +always doable under what is called the +Criterion of ergodicity so the + + align:start position:0% +Criterion of ergodicity so the + + + align:start position:0% +Criterion of ergodicity so the +equivalence between the two formulation + + align:start position:0% +equivalence between the two formulation + + + align:start position:0% +equivalence between the two formulation +that I written before that is + + align:start position:0% +that I written before that is + + + align:start position:0% +that I written before that is +calculating a thermodynamical observable + + align:start position:0% +calculating a thermodynamical observable + + + align:start position:0% +calculating a thermodynamical observable +as an integral in PH space or as an + + align:start position:0% +as an integral in PH space or as an + + + align:start position:0% +as an integral in PH space or as an +integral over a trajectories are + + align:start position:0% +integral over a trajectories are + + + align:start position:0% +integral over a trajectories are +equivalent provided your trajectory is + + align:start position:0% +equivalent provided your trajectory is + + + align:start position:0% +equivalent provided your trajectory is +really able to go all over the place in + + align:start position:0% +really able to go all over the place in + + + align:start position:0% +really able to go all over the place in +Phase space so if again this were pH + + align:start position:0% +Phase space so if again this were pH + + + align:start position:0% +Phase space so if again this were pH +space you could have in principle the + + align:start position:0% +space you could have in principle the + + + align:start position:0% +space you could have in principle the +problem of a noner godic system if there + + align:start position:0% +problem of a noner godic system if there + + + align:start position:0% +problem of a noner godic system if there +is something that prevents your + + align:start position:0% +is something that prevents your + + + align:start position:0% +is something that prevents your +trajectory to sort of reach certain + + align:start position:0% +trajectory to sort of reach certain + + + align:start position:0% +trajectory to sort of reach certain +so-call forbidden segments in your face + + align:start position:0% +so-call forbidden segments in your face + + + align:start position:0% +so-call forbidden segments in your face +space and I can give you an example + + align:start position:0% +space and I can give you an example + + + align:start position:0% +space and I can give you an example +suppose that you are studying sort of + + align:start position:0% +suppose that you are studying sort of + + + align:start position:0% +suppose that you are studying sort of +something like Silicon and you are in + + align:start position:0% +something like Silicon and you are in + + + align:start position:0% +something like Silicon and you are in +the crystalling state and now you heat + + align:start position:0% +the crystalling state and now you heat + + + align:start position:0% +the crystalling state and now you heat +it up and once you go above the melting + + align:start position:0% +it up and once you go above the melting + + + align:start position:0% +it up and once you go above the melting +temperature your silicon will become + + align:start position:0% +temperature your silicon will become + + + align:start position:0% +temperature your silicon will become +liquid okay now suppose that you cool it + + align:start position:0% +liquid okay now suppose that you cool it + + + align:start position:0% +liquid okay now suppose that you cool it +down again below now the melting + + align:start position:0% +down again below now the melting + + + align:start position:0% +down again below now the melting +temperature okay in principle the liquid + + align:start position:0% +temperature okay in principle the liquid + + + align:start position:0% +temperature okay in principle the liquid +silicon should become again crystalline + + align:start position:0% +silicon should become again crystalline + + + align:start position:0% +silicon should become again crystalline +silicon because at that temperature in + + align:start position:0% +silicon because at that temperature in + + + align:start position:0% +silicon because at that temperature in +which we have sort of you know brought + + align:start position:0% +which we have sort of you know brought + + + align:start position:0% +which we have sort of you know brought +it back to the thermodynamical stable + + align:start position:0% +it back to the thermodynamical stable + + + align:start position:0% +it back to the thermodynamical stable +state is really the crystal in solid if + + align:start position:0% +state is really the crystal in solid if + + + align:start position:0% +state is really the crystal in solid if +you do that in practice with a molecular + + align:start position:0% +you do that in practice with a molecular + + + align:start position:0% +you do that in practice with a molecular +Dynamic simulation you'll see that you + + align:start position:0% +Dynamic simulation you'll see that you + + + align:start position:0% +Dynamic simulation you'll see that you +start from the crystal you heat it up it + + align:start position:0% +start from the crystal you heat it up it + + + align:start position:0% +start from the crystal you heat it up it +becomes a liquid with no problems and + + align:start position:0% +becomes a liquid with no problems and + + + align:start position:0% +becomes a liquid with no problems and +then you cool it back down and instead + + align:start position:0% +then you cool it back down and instead + + + align:start position:0% +then you cool it back down and instead +of going back to a crystal it goes back + + align:start position:0% +of going back to a crystal it goes back + + + align:start position:0% +of going back to a crystal it goes back +to a glassy amorphous State okay silicon + + align:start position:0% +to a glassy amorphous State okay silicon + + + align:start position:0% +to a glassy amorphous State okay silicon +will sort of find itself in a + + align:start position:0% +will sort of find itself in a + + + align:start position:0% +will sort of find itself in a +configuration in which locally all atoms + + align:start position:0% +configuration in which locally all atoms + + + align:start position:0% +configuration in which locally all atoms +are happy to be for for + + align:start position:0% +are happy to be for for + + + align:start position:0% +are happy to be for for +coordinated but if we look at the long R + + align:start position:0% +coordinated but if we look at the long R + + + align:start position:0% +coordinated but if we look at the long R +long range order is completely lost the + + align:start position:0% +long range order is completely lost the + + + align:start position:0% +long range order is completely lost the +system is not crystalling anymore it's + + align:start position:0% +system is not crystalling anymore it's + + + align:start position:0% +system is not crystalling anymore it's +glassy what's happening there well it + + align:start position:0% +glassy what's happening there well it + + + align:start position:0% +glassy what's happening there well it +happens that it's just for a liquid + + align:start position:0% +happens that it's just for a liquid + + + align:start position:0% +happens that it's just for a liquid +cooling down so much easier to sort of + + align:start position:0% +cooling down so much easier to sort of + + + align:start position:0% +cooling down so much easier to sort of +you know trap itself into a set of you + + align:start position:0% +you know trap itself into a set of you + + + align:start position:0% +you know trap itself into a set of you +know configurations in which atoms are + + align:start position:0% +know configurations in which atoms are + + + align:start position:0% +know configurations in which atoms are +really fairly happy as they are because + + align:start position:0% +really fairly happy as they are because + + + align:start position:0% +really fairly happy as they are because +what is important for silicon atoms is + + align:start position:0% +what is important for silicon atoms is + + + align:start position:0% +what is important for silicon atoms is +to be fourfold + + align:start position:0% +to be fourfold + + + align:start position:0% +to be fourfold +coordinated but what is important to be + + align:start position:0% +coordinated but what is important to be + + + align:start position:0% +coordinated but what is important to be +in a crystal is that this fourfold + + align:start position:0% +in a crystal is that this fourfold + + + align:start position:0% +in a crystal is that this fourfold +coordination sort of extends and become + + align:start position:0% +coordination sort of extends and become + + + align:start position:0% +coordination sort of extends and become +long range order but for silicon it's + + align:start position:0% +long range order but for silicon it's + + + align:start position:0% +long range order but for silicon it's +very inexpensive to mess up that long + + align:start position:0% +very inexpensive to mess up that long + + + align:start position:0% +very inexpensive to mess up that long +range order like for many other system + + align:start position:0% +range order like for many other system + + + align:start position:0% +range order like for many other system +and you know in principle same thing + + align:start position:0% +and you know in principle same thing + + + align:start position:0% +and you know in principle same thing +happens for polymers you know sort of + + align:start position:0% +happens for polymers you know sort of + + + align:start position:0% +happens for polymers you know sort of +you lower it down they sort of get + + align:start position:0% +you lower it down they sort of get + + + align:start position:0% +you lower it down they sort of get +chopped in a glassy configuration a lot + + align:start position:0% +chopped in a glassy configuration a lot + + + align:start position:0% +chopped in a glassy configuration a lot +of polymers might want to stay actually + + align:start position:0% +of polymers might want to stay actually + + + align:start position:0% +of polymers might want to stay actually +in a crystalline state but really that + + align:start position:0% +in a crystalline state but really that + + + align:start position:0% +in a crystalline state but really that +is impossible to reach and so if you + + align:start position:0% +is impossible to reach and so if you + + + align:start position:0% +is impossible to reach and so if you +want to study say what are the + + align:start position:0% +want to study say what are the + + + align:start position:0% +want to study say what are the +properties of your silicon and you have + + align:start position:0% +properties of your silicon and you have + + + align:start position:0% +properties of your silicon and you have +are obtaining or you are trying to + + align:start position:0% +are obtaining or you are trying to + + + align:start position:0% +are obtaining or you are trying to +obtain your silicon structure from a + + align:start position:0% +obtain your silicon structure from a + + + align:start position:0% +obtain your silicon structure from a +liquid that you cool it down you'll + + align:start position:0% +liquid that you cool it down you'll + + + align:start position:0% +liquid that you cool it down you'll +actually sort of you know in your + + align:start position:0% +actually sort of you know in your + + + align:start position:0% +actually sort of you know in your +molecular Dynamics you'll keep sort of + + align:start position:0% +molecular Dynamics you'll keep sort of + + + align:start position:0% +molecular Dynamics you'll keep sort of +orbiting around in this sort of glassy + + align:start position:0% +orbiting around in this sort of glassy + + + align:start position:0% +orbiting around in this sort of glassy +masses State and will never reach that + + align:start position:0% +masses State and will never reach that + + + align:start position:0% +masses State and will never reach that +region of face space that is actually + + align:start position:0% +region of face space that is actually + + + align:start position:0% +region of face space that is actually +very very small because it needs to have + + align:start position:0% +very very small because it needs to have + + + align:start position:0% +very very small because it needs to have +all atoms long range in very specific + + align:start position:0% +all atoms long range in very specific + + + align:start position:0% +all atoms long range in very specific +position and so you're really sort of + + align:start position:0% +position and so you're really sort of + + + align:start position:0% +position and so you're really sort of +spanning a system in a non-ergodic way + + align:start position:0% +spanning a system in a non-ergodic way + + + align:start position:0% +spanning a system in a non-ergodic way +that is you spend a lot of time in + + align:start position:0% +that is you spend a lot of time in + + + align:start position:0% +that is you spend a lot of time in +region of face space that are not really + + align:start position:0% +region of face space that are not really + + + align:start position:0% +region of face space that are not really +representative but out of which is very + + align:start position:0% +representative but out of which is very + + + align:start position:0% +representative but out of which is very +difficult to escape okay so there are + + align:start position:0% +difficult to escape okay so there are + + + align:start position:0% +difficult to escape okay so there are +problems in sort of you know again Brute + + align:start position:0% +problems in sort of you know again Brute + + + align:start position:0% +problems in sort of you know again Brute +Force molecular Dynamics approach Roes + + align:start position:0% +Force molecular Dynamics approach Roes + + + align:start position:0% +Force molecular Dynamics approach Roes +that you have to be careful + + align:start position:0% +that you have to be careful + + + align:start position:0% +that you have to be careful +about okay so let's see how we actually + + align:start position:0% +about okay so let's see how we actually + + + align:start position:0% +about okay so let's see how we actually +go and try to do this on a computer + + align:start position:0% +go and try to do this on a computer + + + align:start position:0% +go and try to do this on a computer +experiment and you know I'll start with + + align:start position:0% +experiment and you know I'll start with + + + align:start position:0% +experiment and you know I'll start with +the simplest case that is what is called + + align:start position:0% +the simplest case that is what is called + + + align:start position:0% +the simplest case that is what is called +the microcanonical case that is we + + align:start position:0% +the microcanonical case that is we + + + align:start position:0% +the microcanonical case that is we +perform a simulation where the number of + + align:start position:0% +perform a simulation where the number of + + + align:start position:0% +perform a simulation where the number of +particle is constant the volume is + + align:start position:0% +particle is constant the volume is + + + align:start position:0% +particle is constant the volume is +constant and the total energy of the + + align:start position:0% +constant and the total energy of the + + + align:start position:0% +constant and the total energy of the +system is constant this is you know what + + align:start position:0% +system is constant this is you know what + + + align:start position:0% +system is constant this is you know what +is called a thermodynamical Ensemble + + align:start position:0% +is called a thermodynamical Ensemble + + + align:start position:0% +is called a thermodynamical Ensemble +again these are all sort of extensive + + align:start position:0% +again these are all sort of extensive + + + align:start position:0% +again these are all sort of extensive +variables and you're fixing them uh + + align:start position:0% +variables and you're fixing them uh + + + align:start position:0% +variables and you're fixing them uh +sometimes you know it's appropriate + + align:start position:0% +sometimes you know it's appropriate + + + align:start position:0% +sometimes you know it's appropriate +instead to do a leand transformation and + + align:start position:0% +instead to do a leand transformation and + + + align:start position:0% +instead to do a leand transformation and +go into a different thermodynamical + + align:start position:0% +go into a different thermodynamical + + + align:start position:0% +go into a different thermodynamical +Ensemble so you could want not to be at + + align:start position:0% +Ensemble so you could want not to be at + + + align:start position:0% +Ensemble so you could want not to be at +a constant volume but you might want to + + align:start position:0% +a constant volume but you might want to + + + align:start position:0% +a constant volume but you might want to +study a system at a constant pressure + + align:start position:0% +study a system at a constant pressure + + + align:start position:0% +study a system at a constant pressure +where the volume changes and so we need + + align:start position:0% +where the volume changes and so we need + + + align:start position:0% +where the volume changes and so we need +to describe how we'll actually be able + + align:start position:0% +to describe how we'll actually be able + + + align:start position:0% +to describe how we'll actually be able +to do that that is how we we be able to + + align:start position:0% +to do that that is how we we be able to + + + align:start position:0% +to do that that is how we we be able to +move to a system in which different + + align:start position:0% +move to a system in which different + + + align:start position:0% +move to a system in which different +intensive thermodynamical variables are + + align:start position:0% +intensive thermodynamical variables are + + + align:start position:0% +intensive thermodynamical variables are +constant but if you take a system of + + align:start position:0% +constant but if you take a system of + + + align:start position:0% +constant but if you take a system of +particles in periodic boundary + + align:start position:0% +particles in periodic boundary + + + align:start position:0% +particles in periodic boundary +conditions and you have sort of you know + + align:start position:0% +conditions and you have sort of you know + + + align:start position:0% +conditions and you have sort of you know +10 water molecules in a certain unit + + align:start position:0% +10 water molecules in a certain unit + + + align:start position:0% +10 water molecules in a certain unit +cell and you evolve them with the Newton + + align:start position:0% +cell and you evolve them with the Newton + + + align:start position:0% +cell and you evolve them with the Newton +equation of motion you can obviously + + align:start position:0% +equation of motion you can obviously + + + align:start position:0% +equation of motion you can obviously +know that the number of molecules and + + align:start position:0% +know that the number of molecules and + + + align:start position:0% +know that the number of molecules and +the volume of the unit cell are not + + align:start position:0% +the volume of the unit cell are not + + + align:start position:0% +the volume of the unit cell are not +going to change and if you integrate + + align:start position:0% +going to change and if you integrate + + + align:start position:0% +going to change and if you integrate +your equation of motion appropriately + + align:start position:0% +your equation of motion appropriately + + + align:start position:0% +your equation of motion appropriately +the total energy of the system that is + + align:start position:0% +the total energy of the system that is + + + align:start position:0% +the total energy of the system that is +the kinetic energy plus the potential + + align:start position:0% +the kinetic energy plus the potential + + + align:start position:0% +the kinetic energy plus the potential +energy is not going to change and so as + + align:start position:0% +energy is not going to change and so as + + + align:start position:0% +energy is not going to change and so as +we evolve this point in Phase space it + + align:start position:0% +we evolve this point in Phase space it + + + align:start position:0% +we evolve this point in Phase space it +trajectory is going to span what we call + + align:start position:0% +trajectory is going to span what we call + + + align:start position:0% +trajectory is going to span what we call +the + + align:start position:0% +the + + + align:start position:0% +the +microcanonical Ensemble and you let this + + align:start position:0% +microcanonical Ensemble and you let this + + + align:start position:0% +microcanonical Ensemble and you let this +point evolve long enough and all of a + + align:start position:0% +point evolve long enough and all of a + + + align:start position:0% +point evolve long enough and all of a +sudden you will have a meaningful + + align:start position:0% +sudden you will have a meaningful + + + align:start position:0% +sudden you will have a meaningful +trajectory that is a meaningful assembly + + align:start position:0% +trajectory that is a meaningful assembly + + + align:start position:0% +trajectory that is a meaningful assembly +collection of micro states of + + align:start position:0% +collection of micro states of + + + align:start position:0% +collection of micro states of +Representative configuration in space + + align:start position:0% +Representative configuration in space + + + align:start position:0% +Representative configuration in space +and in velocities of your system out of + + align:start position:0% +and in velocities of your system out of + + + align:start position:0% +and in velocities of your system out of +which you can calculate averages of any + + align:start position:0% +which you can calculate averages of any + + + align:start position:0% +which you can calculate averages of any +of the observables that you want to + + align:start position:0% +of the observables that you want to + + + align:start position:0% +of the observables that you want to +calculate and that you want to + + align:start position:0% +calculate and that you want to + + + align:start position:0% +calculate and that you want to +characterize so what do you do in this + + align:start position:0% +characterize so what do you do in this + + + align:start position:0% +characterize so what do you do in this +sort of molecular Dynamic simulations + + align:start position:0% +sort of molecular Dynamic simulations + + + align:start position:0% +sort of molecular Dynamic simulations +well there are really four important + + align:start position:0% +well there are really four important + + + align:start position:0% +well there are really four important +steps that you need to take into account + + align:start position:0% +steps that you need to take into account + + + align:start position:0% +steps that you need to take into account +and we'll sort of keep thinking at Water + + align:start position:0% +and we'll sort of keep thinking at Water + + + align:start position:0% +and we'll sort of keep thinking at Water +liquid water as an example that is you + + align:start position:0% +liquid water as an example that is you + + + align:start position:0% +liquid water as an example that is you +need to start from something that is you + + align:start position:0% +need to start from something that is you + + + align:start position:0% +need to start from something that is you +need to put your water molecule in + + align:start position:0% +need to put your water molecule in + + + align:start position:0% +need to put your water molecule in +certain position and you need to give + + align:start position:0% +certain position and you need to give + + + align:start position:0% +certain position and you need to give +them initial velocities and you are + + align:start position:0% +them initial velocities and you are + + + align:start position:0% +them initial velocities and you are +almost never going to be good enough in + + align:start position:0% +almost never going to be good enough in + + + align:start position:0% +almost never going to be good enough in +sort of choosing a state of the system + + align:start position:0% +sort of choosing a state of the system + + + align:start position:0% +sort of choosing a state of the system +that is somehow meaningful you'll always + + align:start position:0% +that is somehow meaningful you'll always + + + align:start position:0% +that is somehow meaningful you'll always +when you start building something in + + align:start position:0% +when you start building something in + + + align:start position:0% +when you start building something in +complex put molecules in places that + + align:start position:0% +complex put molecules in places that + + + align:start position:0% +complex put molecules in places that +they don't want to stay and one needs to + + align:start position:0% +they don't want to stay and one needs to + + + align:start position:0% +they don't want to stay and one needs to +be very careful then in in all of this + + align:start position:0% +be very careful then in in all of this + + + align:start position:0% +be very careful then in in all of this +but suppose that we have in any case an + + align:start position:0% +but suppose that we have in any case an + + + align:start position:0% +but suppose that we have in any case an +initial configuration of position and + + align:start position:0% +initial configuration of position and + + + align:start position:0% +initial configuration of position and +velocity then what we need to do is over + + align:start position:0% +velocity then what we need to do is over + + + align:start position:0% +velocity then what we need to do is over +and over again integrate the equation of + + align:start position:0% +and over again integrate the equation of + + + align:start position:0% +and over again integrate the equation of +motion that is from the current position + + align:start position:0% +motion that is from the current position + + + align:start position:0% +motion that is from the current position +and the current velocities predicted the + + align:start position:0% +and the current velocities predicted the + + + align:start position:0% +and the current velocities predicted the +new position after a certain time and + + align:start position:0% +new position after a certain time and + + + align:start position:0% +new position after a certain time and +once you have the new position at + + align:start position:0% +once you have the new position at + + + align:start position:0% +once you have the new position at +certain time you can recalculate what + + align:start position:0% +certain time you can recalculate what + + + align:start position:0% +certain time you can recalculate what +are the forces acting on the particle in + + align:start position:0% +are the forces acting on the particle in + + + align:start position:0% +are the forces acting on the particle in +the new position and with these forces + + align:start position:0% +the new position and with these forces + + + align:start position:0% +the new position and with these forces +you can again sort of move the particles + + align:start position:0% +you can again sort of move the particles + + + align:start position:0% +you can again sort of move the particles +by certain amount and so on and so forth + + align:start position:0% +by certain amount and so on and so forth + + + align:start position:0% +by certain amount and so on and so forth +and that is sort of you know where the + + align:start position:0% +and that is sort of you know where the + + + align:start position:0% +and that is sort of you know where the +molecular Dynamics algorithm comes into + + align:start position:0% +molecular Dynamics algorithm comes into + + + align:start position:0% +molecular Dynamics algorithm comes into +play we need to integrate our equation + + align:start position:0% +play we need to integrate our equation + + + align:start position:0% +play we need to integrate our equation +of motion and with this our system will + + align:start position:0% +of motion and with this our system will + + + align:start position:0% +of motion and with this our system will +start to evolve we have put that point + + align:start position:0% +start to evolve we have put that point + + + align:start position:0% +start to evolve we have put that point +in facee space in motion and just start + + align:start position:0% +in facee space in motion and just start + + + align:start position:0% +in facee space in motion and just start +moving around and if we are integrating + + align:start position:0% +moving around and if we are integrating + + + align:start position:0% +moving around and if we are integrating +correctly the total energy of the system + + align:start position:0% +correctly the total energy of the system + + + align:start position:0% +correctly the total energy of the system +is going to be + + align:start position:0% +is going to be + + + align:start position:0% +is going to be +conserved now what we need to do is we + + align:start position:0% +conserved now what we need to do is we + + + align:start position:0% +conserved now what we need to do is we +need to make sure that our + + align:start position:0% +need to make sure that our + + + align:start position:0% +need to make sure that our +characterization our thermodynamical + + align:start position:0% +characterization our thermodynamical + + + align:start position:0% +characterization our thermodynamical +averages do not depend on our initial + + align:start position:0% +averages do not depend on our initial + + + align:start position:0% +averages do not depend on our initial +condition again we have sort of you know + + align:start position:0% +condition again we have sort of you know + + + align:start position:0% +condition again we have sort of you know +started from a configuration that we + + align:start position:0% +started from a configuration that we + + + align:start position:0% +started from a configuration that we +have built by hand and because of that + + align:start position:0% +have built by hand and because of that + + + align:start position:0% +have built by hand and because of that +it's most likely uh very unfavorable + + align:start position:0% +it's most likely uh very unfavorable + + + align:start position:0% +it's most likely uh very unfavorable +configuration of the system okay so we + + align:start position:0% +configuration of the system okay so we + + + align:start position:0% +configuration of the system okay so we +need to let the system + + align:start position:0% +need to let the system + + + align:start position:0% +need to let the system +evolve and somehow you know start + + align:start position:0% +evolve and somehow you know start + + + align:start position:0% +evolve and somehow you know start +figuring out really in which condition + + align:start position:0% +figuring out really in which condition + + + align:start position:0% +figuring out really in which condition +it would want to stay think at the + + align:start position:0% +it would want to stay think at the + + + align:start position:0% +it would want to stay think at the +previous example of silicon that is + + align:start position:0% +previous example of silicon that is + + + align:start position:0% +previous example of silicon that is +glossifying well you know we had liquid + + align:start position:0% +glossifying well you know we had liquid + + + align:start position:0% +glossifying well you know we had liquid +silicon we have cool it down in a way + + align:start position:0% +silicon we have cool it down in a way + + + align:start position:0% +silicon we have cool it down in a way +what's happening is that we are never + + align:start position:0% +what's happening is that we are never + + + align:start position:0% +what's happening is that we are never +equilibrating it because the system goes + + align:start position:0% +equilibrating it because the system goes + + + align:start position:0% +equilibrating it because the system goes +into a glass phase and so it never loses + + align:start position:0% +into a glass phase and so it never loses + + + align:start position:0% +into a glass phase and so it never loses +memory of its initial Condition it's + + align:start position:0% +memory of its initial Condition it's + + + align:start position:0% +memory of its initial Condition it's +always sort of Trapped In This pseudo + + align:start position:0% +always sort of Trapped In This pseudo + + + align:start position:0% +always sort of Trapped In This pseudo +liquid now glassy State while in reality + + align:start position:0% +liquid now glassy State while in reality + + + align:start position:0% +liquid now glassy State while in reality +at a temperature below the freezing or + + align:start position:0% +at a temperature below the freezing or + + + align:start position:0% +at a temperature below the freezing or +the melting point equilibrium would be + + align:start position:0% +the melting point equilibrium would be + + + align:start position:0% +the melting point equilibrium would be +given by a crystalling state with the + + align:start position:0% +given by a crystalling state with the + + + align:start position:0% +given by a crystalling state with the +ions vibrating so there are cases in + + align:start position:0% +ions vibrating so there are cases in + + + align:start position:0% +ions vibrating so there are cases in +which equilibration is so difficult that + + align:start position:0% +which equilibration is so difficult that + + + align:start position:0% +which equilibration is so difficult that +we actually never reach it silicon never + + align:start position:0% +we actually never reach it silicon never + + + align:start position:0% +we actually never reach it silicon never +go to a crystal and that's why we need + + align:start position:0% +go to a crystal and that's why we need + + + align:start position:0% +go to a crystal and that's why we need +to be careful but in most cases + + align:start position:0% +to be careful but in most cases + + + align:start position:0% +to be careful but in most cases +hopefully we are lucky and we lose + + align:start position:0% +hopefully we are lucky and we lose + + + align:start position:0% +hopefully we are lucky and we lose +memory of initial condition see the + + align:start position:0% +memory of initial condition see the + + + align:start position:0% +memory of initial condition see the +opposite is actually sort of very easy + + align:start position:0% +opposite is actually sort of very easy + + + align:start position:0% +opposite is actually sort of very easy +to achieve if we start from the solid + + align:start position:0% +to achieve if we start from the solid + + + align:start position:0% +to achieve if we start from the solid +and we warm it up it becomes a liquid + + align:start position:0% +and we warm it up it becomes a liquid + + + align:start position:0% +and we warm it up it becomes a liquid +and if we wait long enough that liquid + + align:start position:0% +and if we wait long enough that liquid + + + align:start position:0% +and if we wait long enough that liquid +will have lost all memory of having come + + align:start position:0% +will have lost all memory of having come + + + align:start position:0% +will have lost all memory of having come +from a solid okay so it's actually very + + align:start position:0% +from a solid okay so it's actually very + + + align:start position:0% +from a solid okay so it's actually very +easy in One Direction and very difficult + + align:start position:0% +easy in One Direction and very difficult + + + align:start position:0% +easy in One Direction and very difficult +in the other direction but once sort of + + align:start position:0% +in the other direction but once sort of + + + align:start position:0% +in the other direction but once sort of +this equilibration time has passed fast + + align:start position:0% +this equilibration time has passed fast + + + align:start position:0% +this equilibration time has passed fast +well at that point we have truly + + align:start position:0% +well at that point we have truly + + + align:start position:0% +well at that point we have truly +everything in place our point in face + + align:start position:0% +everything in place our point in face + + + align:start position:0% +everything in place our point in face +space is moving around and is really + + align:start position:0% +space is moving around and is really + + + align:start position:0% +space is moving around and is really +going into the regions of high + + align:start position:0% +going into the regions of high + + + align:start position:0% +going into the regions of high +probability and distributed according to + + align:start position:0% +probability and distributed according to + + + align:start position:0% +probability and distributed according to +bolman distribution and so at that point + + align:start position:0% +bolman distribution and so at that point + + + align:start position:0% +bolman distribution and so at that point +we can sort of start and average among + + align:start position:0% +we can sort of start and average among + + + align:start position:0% +we can sort of start and average among +any of the sort of physical observable + + align:start position:0% +any of the sort of physical observable + + + align:start position:0% +any of the sort of physical observable +that we want uh that we want to + + align:start position:0% +that we want uh that we want to + + + align:start position:0% +that we want uh that we want to +calculate and so there are these four + + align:start position:0% +calculate and so there are these four + + + align:start position:0% +calculate and so there are these four +phases and I'll brief ly sort of you + + align:start position:0% +phases and I'll brief ly sort of you + + + align:start position:0% +phases and I'll brief ly sort of you +know mention how we actually choose them + + align:start position:0% +know mention how we actually choose them + + + align:start position:0% +know mention how we actually choose them +um initialization well again we need + + align:start position:0% +um initialization well again we need + + + align:start position:0% +um initialization well again we need +position and velocities you need to sort + + align:start position:0% +position and velocities you need to sort + + + align:start position:0% +position and velocities you need to sort +of you know be careful in particular to + + align:start position:0% +of you know be careful in particular to + + + align:start position:0% +of you know be careful in particular to +avoid overlap between your molecules if + + align:start position:0% +avoid overlap between your molecules if + + + align:start position:0% +avoid overlap between your molecules if +you put two atoms very close they are + + align:start position:0% +you put two atoms very close they are + + + align:start position:0% +you put two atoms very close they are +going to repel each other with an + + align:start position:0% +going to repel each other with an + + + align:start position:0% +going to repel each other with an +enormous strength and you know sort of + + align:start position:0% +enormous strength and you know sort of + + + align:start position:0% +enormous strength and you know sort of +if you put them close enough they going + + align:start position:0% +if you put them close enough they going + + + align:start position:0% +if you put them close enough they going +to shoot in opposite direction very + + align:start position:0% +to shoot in opposite direction very + + + align:start position:0% +to shoot in opposite direction very +quickly and completely sort of kick off + + align:start position:0% +quickly and completely sort of kick off + + + align:start position:0% +quickly and completely sort of kick off +and mess up everything on the side so + + align:start position:0% +and mess up everything on the side so + + + align:start position:0% +and mess up everything on the side so +what is difficult is really always in + + align:start position:0% +what is difficult is really always in + + + align:start position:0% +what is difficult is really always in +configuration space finding the right + + align:start position:0% +configuration space finding the right + + + align:start position:0% +configuration space finding the right +structures this is the difficult part of + + align:start position:0% +structures this is the difficult part of + + + align:start position:0% +structures this is the difficult part of +choosing initial condition choosing + + align:start position:0% +choosing initial condition choosing + + + align:start position:0% +choosing initial condition choosing +velocities is much easier uh one + + align:start position:0% +velocities is much easier uh one + + + align:start position:0% +velocities is much easier uh one +possibility is just giving zero velocity + + align:start position:0% +possibility is just giving zero velocity + + + align:start position:0% +possibility is just giving zero velocity +to the system or very small velocity and + + align:start position:0% +to the system or very small velocity and + + + align:start position:0% +to the system or very small velocity and +then sort of slowly adding things and + + align:start position:0% +then sort of slowly adding things and + + + align:start position:0% +then sort of slowly adding things and +what we usually say is that + + align:start position:0% +what we usually say is that + + + align:start position:0% +what we usually say is that +configuration in velocity space is much + + align:start position:0% +configuration in velocity space is much + + + align:start position:0% +configuration in velocity space is much +faster and this is the reason think at a + + align:start position:0% +faster and this is the reason think at a + + + align:start position:0% +faster and this is the reason think at a +trajectory for a moment of one particle + + align:start position:0% +trajectory for a moment of one particle + + + align:start position:0% +trajectory for a moment of one particle +and think what happens when you have a + + align:start position:0% +and think what happens when you have a + + + align:start position:0% +and think what happens when you have a +collision suppose that you have + + align:start position:0% +collision suppose that you have + + + align:start position:0% +collision suppose that you have +particles for a moment that are hard + + align:start position:0% +particles for a moment that are hard + + + align:start position:0% +particles for a moment that are hard +spheres in a collision the velocity of + + align:start position:0% +spheres in a collision the velocity of + + + align:start position:0% +spheres in a collision the velocity of +the particle all of a sudden change + + align:start position:0% +the particle all of a sudden change + + + align:start position:0% +the particle all of a sudden change +sign so in the velocity part of the + + align:start position:0% +sign so in the velocity part of the + + + align:start position:0% +sign so in the velocity part of the +phase space your point makes a sudden + + align:start position:0% +phase space your point makes a sudden + + + align:start position:0% +phase space your point makes a sudden +jump okay because the velocity that was + + align:start position:0% +jump okay because the velocity that was + + + align:start position:0% +jump okay because the velocity that was ++ 10 has become all of a sudden minus 10 + + align:start position:0% ++ 10 has become all of a sudden minus 10 + + + align:start position:0% ++ 10 has become all of a sudden minus 10 +so in velocity space for you know the + + align:start position:0% +so in velocity space for you know the + + + align:start position:0% +so in velocity space for you know the +limit case of a system of hard spheres + + align:start position:0% +limit case of a system of hard spheres + + + align:start position:0% +limit case of a system of hard spheres +your representative Point hops + + align:start position:0% +your representative Point hops + + + align:start position:0% +your representative Point hops +everywhere continuously in reality I + + align:start position:0% +everywhere continuously in reality I + + + align:start position:0% +everywhere continuously in reality I +mean you have interaction at all times + + align:start position:0% +mean you have interaction at all times + + + align:start position:0% +mean you have interaction at all times +and you don't really hope but you can + + align:start position:0% +and you don't really hope but you can + + + align:start position:0% +and you don't really hope but you can +sort of you know move very quickly from + + align:start position:0% +sort of you know move very quickly from + + + align:start position:0% +sort of you know move very quickly from +one region to the other region there is + + align:start position:0% +one region to the other region there is + + + align:start position:0% +one region to the other region there is +not anything similar to The Glass + + align:start position:0% +not anything similar to The Glass + + + align:start position:0% +not anything similar to The Glass +entanglement in configuration space so + + align:start position:0% +entanglement in configuration space so + + + align:start position:0% +entanglement in configuration space so +it's very easy to sort of you know + + align:start position:0% +it's very easy to sort of you know + + + align:start position:0% +it's very easy to sort of you know +thermalize velocity it's very difficult + + align:start position:0% +thermalize velocity it's very difficult + + + align:start position:0% +thermalize velocity it's very difficult +to thermalize and equilibrate position + + align:start position:0% +to thermalize and equilibrate position + + + align:start position:0% +to thermalize and equilibrate position +and that's where all sort of you know + + align:start position:0% +and that's where all sort of you know + + + align:start position:0% +and that's where all sort of you know +you need to be careful + + align:start position:0% +you need to be careful + + + align:start position:0% +you need to be careful +and if you really want to be sort of + + align:start position:0% +and if you really want to be sort of + + + align:start position:0% +and if you really want to be sort of +accurate what you can also do instead of + + align:start position:0% +accurate what you can also do instead of + + + align:start position:0% +accurate what you can also do instead of +giving zero velocity to your system you + + align:start position:0% +giving zero velocity to your system you + + + align:start position:0% +giving zero velocity to your system you +can use sort of your concept of + + align:start position:0% +can use sort of your concept of + + + align:start position:0% +can use sort of your concept of +statistical mechanics that is a system + + align:start position:0% +statistical mechanics that is a system + + + align:start position:0% +statistical mechanics that is a system +of classical particles will have a + + align:start position:0% +of classical particles will have a + + + align:start position:0% +of classical particles will have a +distribution of velocities that depends + + align:start position:0% +distribution of velocities that depends + + + align:start position:0% +distribution of velocities that depends +the temperature at which it is and this + + align:start position:0% +the temperature at which it is and this + + + align:start position:0% +the temperature at which it is and this +is Zer in Celsius so it's 273 Kelvin and + + align:start position:0% +is Zer in Celsius so it's 273 Kelvin and + + + align:start position:0% +is Zer in Celsius so it's 273 Kelvin and +sort of the distribution of velocity in + + align:start position:0% +sort of the distribution of velocity in + + + align:start position:0% +sort of the distribution of velocity in +classical system is actually given by + + align:start position:0% +classical system is actually given by + + + align:start position:0% +classical system is actually given by +the Maxwell bolman distribution written + + align:start position:0% +the Maxwell bolman distribution written + + + align:start position:0% +the Maxwell bolman distribution written +above that has basically this shape so + + align:start position:0% +above that has basically this shape so + + + align:start position:0% +above that has basically this shape so +it means that if we are say at 0 Celsius + + align:start position:0% +it means that if we are say at 0 Celsius + + + align:start position:0% +it means that if we are say at 0 Celsius +273 Kelvin we'll have a lot of molecule + + align:start position:0% +273 Kelvin we'll have a lot of molecule + + + align:start position:0% +273 Kelvin we'll have a lot of molecule +with a + + align:start position:0% +with a + + + align:start position:0% +with a +certain uh velocity and then you know + + align:start position:0% +certain uh velocity and then you know + + + align:start position:0% +certain uh velocity and then you know +sort of in principle we can have + + align:start position:0% +sort of in principle we can have + + + align:start position:0% +sort of in principle we can have +molecules with higher and higher + + align:start position:0% +molecules with higher and higher + + + align:start position:0% +molecules with higher and higher +velocity but the probability of finding + + align:start position:0% +velocity but the probability of finding + + + align:start position:0% +velocity but the probability of finding +them decreases and as we increase the + + align:start position:0% +them decreases and as we increase the + + + align:start position:0% +them decreases and as we increase the +temperature the probability distribution + + align:start position:0% +temperature the probability distribution + + + align:start position:0% +temperature the probability distribution +of the velocities for the molecules + + align:start position:0% +of the velocities for the molecules + + + align:start position:0% +of the velocities for the molecules +changes and so as usual you can sort of + + align:start position:0% +changes and so as usual you can sort of + + + align:start position:0% +changes and so as usual you can sort of +you know Define both a median or an + + align:start position:0% +you know Define both a median or an + + + align:start position:0% +you know Define both a median or an +average in your system that is you can + + align:start position:0% +average in your system that is you can + + + align:start position:0% +average in your system that is you can +look at what is the most likely velocity + + align:start position:0% +look at what is the most likely velocity + + + align:start position:0% +look at what is the most likely velocity +that is the top of this curve at 0 + + align:start position:0% +that is the top of this curve at 0 + + + align:start position:0% +that is the top of this curve at 0 +Celsius or you could also Define what is + + align:start position:0% +Celsius or you could also Define what is + + + align:start position:0% +Celsius or you could also Define what is +the average velocity and since that this + + align:start position:0% +the average velocity and since that this + + + align:start position:0% +the average velocity and since that this +curve is asymmetric is going to be + + align:start position:0% +curve is asymmetric is going to be + + + align:start position:0% +curve is asymmetric is going to be +really sort of shifted a little bit and + + align:start position:0% +really sort of shifted a little bit and + + + align:start position:0% +really sort of shifted a little bit and +these are actually the numerical + + align:start position:0% +these are actually the numerical + + + align:start position:0% +these are actually the numerical +expression for these two velocity the + + align:start position:0% +expression for these two velocity the + + + align:start position:0% +expression for these two velocity the +most likely and the average velocity and + + align:start position:0% +most likely and the average velocity and + + + align:start position:0% +most likely and the average velocity and +so you know sort of I've given you the + + align:start position:0% +so you know sort of I've given you the + + + align:start position:0% +so you know sort of I've given you the +example of an oxygen molecule at room + + align:start position:0% +example of an oxygen molecule at room + + + align:start position:0% +example of an oxygen molecule at room +temperature we are talking about you + + align:start position:0% +temperature we are talking about you + + + align:start position:0% +temperature we are talking about you +know 1,000 m/ second so these velocities + + align:start position:0% +know 1,000 m/ second so these velocities + + + align:start position:0% +know 1,000 m/ second so these velocities +if you want are similar to the speed of + + align:start position:0% +if you want are similar to the speed of + + + align:start position:0% +if you want are similar to the speed of +sound in your material because at the + + align:start position:0% +sound in your material because at the + + + align:start position:0% +sound in your material because at the +end you know sound propagates at certain + + align:start position:0% +end you know sound propagates at certain + + + align:start position:0% +end you know sound propagates at certain +speed because that's the velocity of the + + align:start position:0% +speed because that's the velocity of the + + + align:start position:0% +speed because that's the velocity of the +Collision from one molecule to the next + + align:start position:0% +Collision from one molecule to the next + + + align:start position:0% +Collision from one molecule to the next +that are really carrying sound away so + + align:start position:0% +that are really carrying sound away so + + + align:start position:0% +that are really carrying sound away so +if you want to be sophisticated you give + + align:start position:0% +if you want to be sophisticated you give + + + align:start position:0% +if you want to be sophisticated you give +to your system a set of velocity that + + align:start position:0% +to your system a set of velocity that + + + align:start position:0% +to your system a set of velocity that +could be say all identical to the most + + align:start position:0% +could be say all identical to the most + + + align:start position:0% +could be say all identical to the most +likely velocity but again integration + + align:start position:0% +likely velocity but again integration + + + align:start position:0% +likely velocity but again integration +and thermalization in um equilibration + + align:start position:0% +and thermalization in um equilibration + + + align:start position:0% +and thermalization in um equilibration +and thermalization in velocity space is + + align:start position:0% +and thermalization in velocity space is + + + align:start position:0% +and thermalization in velocity space is +very easy so once you have this that is + + align:start position:0% +very easy so once you have this that is + + + align:start position:0% +very easy so once you have this that is +once you have a set of position and a + + align:start position:0% +once you have a set of position and a + + + align:start position:0% +once you have a set of position and a +set of velocity + + align:start position:0% +set of velocity + + + align:start position:0% +set of velocity +you need to use Newton's equation of + + align:start position:0% +you need to use Newton's equation of + + + align:start position:0% +you need to use Newton's equation of +motion of saying of predicting where + + align:start position:0% +motion of saying of predicting where + + + align:start position:0% +motion of saying of predicting where +your system is going is going to + + align:start position:0% +your system is going is going to + + + align:start position:0% +your system is going is going to +go and so that's when sort of you know + + align:start position:0% +go and so that's when sort of you know + + + align:start position:0% +go and so that's when sort of you know +the molecular Dynamic algorithm come + + align:start position:0% +the molecular Dynamic algorithm come + + + align:start position:0% +the molecular Dynamic algorithm come +into play so what you need to do is as + + align:start position:0% +into play so what you need to do is as + + + align:start position:0% +into play so what you need to do is as +we say you need to use an integrator the + + align:start position:0% +we say you need to use an integrator the + + + align:start position:0% +we say you need to use an integrator the +algorithm that tells you what your next + + align:start position:0% +algorithm that tells you what your next + + + align:start position:0% +algorithm that tells you what your next +position and what your next velocities + + align:start position:0% +position and what your next velocities + + + align:start position:0% +position and what your next velocities +are going to be and there are a number + + align:start position:0% +are going to be and there are a number + + + align:start position:0% +are going to be and there are a number +of + + align:start position:0% +of + + + align:start position:0% +of +integrators uh you know there are sort + + align:start position:0% +integrators uh you know there are sort + + + align:start position:0% +integrators uh you know there are sort +of subtleties but often you find the + + align:start position:0% +of subtleties but often you find the + + + align:start position:0% +of subtleties but often you find the +name of verlet algorithm this is one + + align:start position:0% +name of verlet algorithm this is one + + + align:start position:0% +name of verlet algorithm this is one +class of algorithm and the other sort of + + align:start position:0% +class of algorithm and the other sort of + + + align:start position:0% +class of algorithm and the other sort of +common class is the gear predictor + + align:start position:0% +common class is the gear predictor + + + align:start position:0% +common class is the gear predictor +corrector just to give you the + + align:start position:0% +corrector just to give you the + + + align:start position:0% +corrector just to give you the +terminology and we look in a moment at + + align:start position:0% +terminology and we look in a moment at + + + align:start position:0% +terminology and we look in a moment at +the verlet algorithm they are all fairly + + align:start position:0% +the verlet algorithm they are all fairly + + + align:start position:0% +the verlet algorithm they are all fairly +simple uh but you know what is really + + align:start position:0% +simple uh but you know what is really + + + align:start position:0% +simple uh but you know what is really +important is that this algorithm should + + align:start position:0% +important is that this algorithm should + + + align:start position:0% +important is that this algorithm should +be robust that is you know they should + + align:start position:0% +be robust that is you know they should + + + align:start position:0% +be robust that is you know they should +sort of give you a trajectory that is + + align:start position:0% +sort of give you a trajectory that is + + + align:start position:0% +sort of give you a trajectory that is +very close to the trajectory that you + + align:start position:0% +very close to the trajectory that you + + + align:start position:0% +very close to the trajectory that you +would get from the perfect analytical + + align:start position:0% +would get from the perfect analytical + + + align:start position:0% +would get from the perfect analytical +integration of the equation of motion + + align:start position:0% +integration of the equation of motion + + + align:start position:0% +integration of the equation of motion +and in particular what is the most + + align:start position:0% +and in particular what is the most + + + align:start position:0% +and in particular what is the most +important thing is that they should be + + align:start position:0% +important thing is that they should be + + + align:start position:0% +important thing is that they should be +accurate in say conserving the constant + + align:start position:0% +accurate in say conserving the constant + + + align:start position:0% +accurate in say conserving the constant +of motion as we have seen from the + + align:start position:0% +of motion as we have seen from the + + + align:start position:0% +of motion as we have seen from the +Newton equation of motion the sum of the + + align:start position:0% +Newton equation of motion the sum of the + + + align:start position:0% +Newton equation of motion the sum of the +kinetic energy and the potential energy + + align:start position:0% +kinetic energy and the potential energy + + + align:start position:0% +kinetic energy and the potential energy +should be a constant if your integration + + align:start position:0% +should be a constant if your integration + + + align:start position:0% +should be a constant if your integration +if your numerical evaluation of that + + align:start position:0% +if your numerical evaluation of that + + + align:start position:0% +if your numerical evaluation of that +equation is poor you will see that the + + align:start position:0% +equation is poor you will see that the + + + align:start position:0% +equation is poor you will see that the +constant of motion is not anymore a + + align:start position:0% +constant of motion is not anymore a + + + align:start position:0% +constant of motion is not anymore a +constant so again this is the sanity + + align:start position:0% +constant so again this is the sanity + + + align:start position:0% +constant so again this is the sanity +check on the accuracy of your + + align:start position:0% +check on the accuracy of your + + + align:start position:0% +check on the accuracy of your +integration and there are sort of you + + align:start position:0% +integration and there are sort of you + + + align:start position:0% +integration and there are sort of you +know more subtle uh elements of you know + + align:start position:0% +know more subtle uh elements of you know + + + align:start position:0% +know more subtle uh elements of you know +the integration algorithm that can + + align:start position:0% +the integration algorithm that can + + + align:start position:0% +the integration algorithm that can +become important but we won't go into + + align:start position:0% +become important but we won't go into + + + align:start position:0% +become important but we won't go into +there and then sort of as I said + + align:start position:0% +there and then sort of as I said + + + align:start position:0% +there and then sort of as I said +straightforward integration of the + + align:start position:0% +straightforward integration of the + + + align:start position:0% +straightforward integration of the +Newton equation of motion gives you the + + align:start position:0% +Newton equation of motion gives you the + + + align:start position:0% +Newton equation of motion gives you the +microcanonical ensemble in which the + + align:start position:0% +microcanonical ensemble in which the + + + align:start position:0% +microcanonical ensemble in which the +total energy is conserved but sometimes + + align:start position:0% +total energy is conserved but sometimes + + + align:start position:0% +total energy is conserved but sometimes +you want to study systems in which the + + align:start position:0% +you want to study systems in which the + + + align:start position:0% +you want to study systems in which the +temperature is fixed or you could want + + align:start position:0% +temperature is fixed or you could want + + + align:start position:0% +temperature is fixed or you could want +to study system in which the pressure is + + align:start position:0% +to study system in which the pressure is + + + align:start position:0% +to study system in which the pressure is +fixed and so you need to sort of augment + + align:start position:0% +fixed and so you need to sort of augment + + + align:start position:0% +fixed and so you need to sort of augment +your molecular Dynamic integrator with + + align:start position:0% +your molecular Dynamic integrator with + + + align:start position:0% +your molecular Dynamic integrator with +uh uh some feature that allows you to + + align:start position:0% +uh uh some feature that allows you to + + + align:start position:0% +uh uh some feature that allows you to +control those intensive variables so if + + align:start position:0% +control those intensive variables so if + + + align:start position:0% +control those intensive variables so if +you want say to control the temperature + + align:start position:0% +you want say to control the temperature + + + align:start position:0% +you want say to control the temperature +of the system what we say usually is + + align:start position:0% +of the system what we say usually is + + + align:start position:0% +of the system what we say usually is +that we couple the system to a + + align:start position:0% +that we couple the system to a + + + align:start position:0% +that we couple the system to a +thermostat that is we make sure that the + + align:start position:0% +thermostat that is we make sure that the + + + align:start position:0% +thermostat that is we make sure that the +temperature in your Evolution doesn't + + align:start position:0% +temperature in your Evolution doesn't + + + align:start position:0% +temperature in your Evolution doesn't +change and you'll see examples in the + + align:start position:0% +change and you'll see examples in the + + + align:start position:0% +change and you'll see examples in the +next class of this and uh uh in the case + + align:start position:0% +next class of this and uh uh in the case + + + align:start position:0% +next class of this and uh uh in the case +in particular of something say like the + + align:start position:0% +in particular of something say like the + + + align:start position:0% +in particular of something say like the +temperature you have a whole set of + + align:start position:0% +temperature you have a whole set of + + + align:start position:0% +temperature you have a whole set of +possible thermostats that is you could + + align:start position:0% +possible thermostats that is you could + + + align:start position:0% +possible thermostats that is you could +use um stochastic approaches that is you + + align:start position:0% +use um stochastic approaches that is you + + + align:start position:0% +use um stochastic approaches that is you +have your evolution of your system and + + align:start position:0% +have your evolution of your system and + + + align:start position:0% +have your evolution of your system and +your system doesn't conserve if it's + + align:start position:0% +your system doesn't conserve if it's + + + align:start position:0% +your system doesn't conserve if it's +microcanonical the temperature sometimes + + align:start position:0% +microcanonical the temperature sometimes + + + align:start position:0% +microcanonical the temperature sometimes +it go towards higher temperature + + align:start position:0% +it go towards higher temperature + + + align:start position:0% +it go towards higher temperature +sometimes it's go towards lower + + align:start position:0% +sometimes it's go towards lower + + + align:start position:0% +sometimes it's go towards lower +temperature and you know what you could + + align:start position:0% +temperature and you know what you could + + + align:start position:0% +temperature and you know what you could +do is either every now and then sort of + + align:start position:0% +do is either every now and then sort of + + + align:start position:0% +do is either every now and then sort of +absorb some energy or give back some + + align:start position:0% +absorb some energy or give back some + + + align:start position:0% +absorb some energy or give back some +energy in your system and that would be + + align:start position:0% +energy in your system and that would be + + + align:start position:0% +energy in your system and that would be +a lan dyamics in order to control the + + align:start position:0% +a lan dyamics in order to control the + + + align:start position:0% +a lan dyamics in order to control the +average kinetic energy of your system or + + align:start position:0% +average kinetic energy of your system or + + + align:start position:0% +average kinetic energy of your system or +you could + + align:start position:0% +you could + + + align:start position:0% +you could +somehow for forbid in the microcanonical + + align:start position:0% +somehow for forbid in the microcanonical + + + align:start position:0% +somehow for forbid in the microcanonical +evolution your system to choose a state + + align:start position:0% +evolution your system to choose a state + + + align:start position:0% +evolution your system to choose a state +in which the temperature changes so if + + align:start position:0% +in which the temperature changes so if + + + align:start position:0% +in which the temperature changes so if +your new positions are such that your + + align:start position:0% +your new positions are such that your + + + align:start position:0% +your new positions are such that your +velocity give an increase in temperature + + align:start position:0% +velocity give an increase in temperature + + + align:start position:0% +velocity give an increase in temperature +you just sort of you know shorten how + + align:start position:0% +you just sort of you know shorten how + + + align:start position:0% +you just sort of you know shorten how +much your atoms move in order to make + + align:start position:0% +much your atoms move in order to make + + + align:start position:0% +much your atoms move in order to make +the velocity smaller and in order to + + align:start position:0% +the velocity smaller and in order to + + + align:start position:0% +the velocity smaller and in order to +make the kinetic energy conserved or + + align:start position:0% +make the kinetic energy conserved or + + + align:start position:0% +make the kinetic energy conserved or +there are sort of more complex dynamical + + align:start position:0% +there are sort of more complex dynamical + + + align:start position:0% +there are sort of more complex dynamical +ways of impose temperature that goes + + align:start position:0% +ways of impose temperature that goes + + + align:start position:0% +ways of impose temperature that goes +under the name of extended aonian or + + align:start position:0% +under the name of extended aonian or + + + align:start position:0% +under the name of extended aonian or +extended system of which we'll see an + + align:start position:0% +extended system of which we'll see an + + + align:start position:0% +extended system of which we'll see an +example that is the no + + align:start position:0% +example that is the no + + + align:start position:0% +example that is the no +U but let me give you sort of you know + + align:start position:0% +U but let me give you sort of you know + + + align:start position:0% +U but let me give you sort of you know +really what is the simplest and still + + align:start position:0% +really what is the simplest and still + + + align:start position:0% +really what is the simplest and still +one of the most used uh sort of + + align:start position:0% +one of the most used uh sort of + + + align:start position:0% +one of the most used uh sort of +numerical integrators and it tends to be + + align:start position:0% +numerical integrators and it tends to be + + + align:start position:0% +numerical integrators and it tends to be +very robust and very accurate so you + + align:start position:0% +very robust and very accurate so you + + + align:start position:0% +very robust and very accurate so you +know it's still used in a lot of + + align:start position:0% +know it's still used in a lot of + + + align:start position:0% +know it's still used in a lot of +molecular Dynamic simulation and there + + align:start position:0% +molecular Dynamic simulation and there + + + align:start position:0% +molecular Dynamic simulation and there +is often no reason to do anything better + + align:start position:0% +is often no reason to do anything better + + + align:start position:0% +is often no reason to do anything better +than this so in a way we are in a luier + + align:start position:0% +than this so in a way we are in a luier + + + align:start position:0% +than this so in a way we are in a luier +situation than sort of in quantum + + align:start position:0% +situation than sort of in quantum + + + align:start position:0% +situation than sort of in quantum +mechanics this is good enough in almost + + align:start position:0% +mechanics this is good enough in almost + + + align:start position:0% +mechanics this is good enough in almost +all cases and this is sort of how we + + align:start position:0% +all cases and this is sort of how we + + + align:start position:0% +all cases and this is sort of how we +look at the problem uh that is what we + + align:start position:0% +look at the problem uh that is what we + + + align:start position:0% +look at the problem uh that is what we +need to do always is we need to + + align:start position:0% +need to do always is we need to + + + align:start position:0% +need to do always is we need to +calculate the + + align:start position:0% +calculate the + + + align:start position:0% +calculate the +position of each + + align:start position:0% +position of each + + + align:start position:0% +position of each +particle at a time t plus delta + + align:start position:0% +particle at a time t plus delta + + + align:start position:0% +particle at a time t plus delta +T once we know the position the velocity + + align:start position:0% +T once we know the position the velocity + + + align:start position:0% +T once we know the position the velocity +and the forces on that particle at time + + align:start position:0% +and the forces on that particle at time + + + align:start position:0% +and the forces on that particle at time +T So suppose I'm at certain instant in + + align:start position:0% +T So suppose I'm at certain instant in + + + align:start position:0% +T So suppose I'm at certain instant in +time that I call T I know everything + + align:start position:0% +time that I call T I know everything + + + align:start position:0% +time that I call T I know everything +about my system position velocity and + + align:start position:0% +about my system position velocity and + + + align:start position:0% +about my system position velocity and +forces what I really need to do is + + align:start position:0% +forces what I really need to do is + + + align:start position:0% +forces what I really need to do is +predict what are the new positions and + + align:start position:0% +predict what are the new positions and + + + align:start position:0% +predict what are the new positions and +when I'm in the new positions I want to + + align:start position:0% +when I'm in the new positions I want to + + + align:start position:0% +when I'm in the new positions I want to +calculate the forces again and um evolve + + align:start position:0% +calculate the forces again and um evolve + + + align:start position:0% +calculate the forces again and um evolve +the system and now what do we do well + + align:start position:0% +the system and now what do we do well + + + align:start position:0% +the system and now what do we do well +let's do a simple tailor expansion that + + align:start position:0% +let's do a simple tailor expansion that + + + align:start position:0% +let's do a simple tailor expansion that +is you know this is R of T is a f + + align:start position:0% +is you know this is R of T is a f + + + align:start position:0% +is you know this is R of T is a f +function of the variable T so we can use + + align:start position:0% +function of the variable T so we can use + + + align:start position:0% +function of the variable T so we can use +a tailor expansion and R of t plus delta + + align:start position:0% +a tailor expansion and R of t plus delta + + + align:start position:0% +a tailor expansion and R of t plus delta +T is going to be R of t plus the + + align:start position:0% +T is going to be R of t plus the + + + align:start position:0% +T is going to be R of t plus the +derivative of r with respect to T * + + align:start position:0% +derivative of r with respect to T * + + + align:start position:0% +derivative of r with respect to T * +delta T and that's the velocity plus 1 + + align:start position:0% +delta T and that's the velocity plus 1 + + + align:start position:0% +delta T and that's the velocity plus 1 +12 the second derivative of uh the + + align:start position:0% +12 the second derivative of uh the + + + align:start position:0% +12 the second derivative of uh the +position with respect to time and that's + + align:start position:0% +position with respect to time and that's + + + align:start position:0% +position with respect to time and that's +the acceleration time delta T square and + + align:start position:0% +the acceleration time delta T square and + + + align:start position:0% +the acceleration time delta T square and +so on for the third derivatives and so + + align:start position:0% +so on for the third derivatives and so + + + align:start position:0% +so on for the third derivatives and so +on for the fourth fifth at infinum this + + align:start position:0% +on for the fourth fifth at infinum this + + + align:start position:0% +on for the fourth fifth at infinum this +is just the tailor expansion as a + + align:start position:0% +is just the tailor expansion as a + + + align:start position:0% +is just the tailor expansion as a +function okay and so it gives us the + + align:start position:0% +function okay and so it gives us the + + + align:start position:0% +function okay and so it gives us the +position at t plus delta T knowing all + + align:start position:0% +position at t plus delta T knowing all + + + align:start position:0% +position at t plus delta T knowing all +the derivatives first second third + + align:start position:0% +the derivatives first second third + + + align:start position:0% +the derivatives first second third +fourth n at times T and once we have the + + align:start position:0% +fourth n at times T and once we have the + + + align:start position:0% +fourth n at times T and once we have the +derivatives we can not only sort of + + align:start position:0% +derivatives we can not only sort of + + + align:start position:0% +derivatives we can not only sort of +predict what the position would be at t + + align:start position:0% +predict what the position would be at t + + + align:start position:0% +predict what the position would be at t +plus delta T but also what the position + + align:start position:0% +plus delta T but also what the position + + + align:start position:0% +plus delta T but also what the position +would be at T minus delta T and it's + + align:start position:0% +would be at T minus delta T and it's + + + align:start position:0% +would be at T minus delta T and it's +written here and if you think the uh + + align:start position:0% +written here and if you think the uh + + + align:start position:0% +written here and if you think the uh +terms with an odd power change sign in + + align:start position:0% +terms with an odd power change sign in + + + align:start position:0% +terms with an odd power change sign in +delta T and the terms with an even power + + align:start position:0% +delta T and the terms with an even power + + + align:start position:0% +delta T and the terms with an even power +in delta T do not change sign so we have + + align:start position:0% +in delta T do not change sign so we have + + + align:start position:0% +in delta T do not change sign so we have +just done a tailor expansion and now + + align:start position:0% +just done a tailor expansion and now + + + align:start position:0% +just done a tailor expansion and now +what we do is we actually sum these two + + align:start position:0% +what we do is we actually sum these two + + + align:start position:0% +what we do is we actually sum these two +quantities together okay and this is + + align:start position:0% +quantities together okay and this is + + + align:start position:0% +quantities together okay and this is +what + + align:start position:0% +what + + + align:start position:0% +what +we obtain okay we sum the two quantities + + align:start position:0% +we obtain okay we sum the two quantities + + + align:start position:0% +we obtain okay we sum the two quantities +together all the odd terms disappear + + align:start position:0% +together all the odd terms disappear + + + align:start position:0% +together all the odd terms disappear +this sum to zero this s to zero the + + align:start position:0% +this sum to zero this s to zero the + + + align:start position:0% +this sum to zero this s to zero the +fifth order seventh order and so s to + + align:start position:0% +fifth order seventh order and so s to + + + align:start position:0% +fifth order seventh order and so s to +zero so what we have is that we have rt + + align:start position:0% +zero so what we have is that we have rt + + + align:start position:0% +zero so what we have is that we have rt ++ delta T plus RT minus delta T is equal + + align:start position:0% ++ delta T plus RT minus delta T is equal + + + align:start position:0% ++ delta T plus RT minus delta T is equal +a 2 * RT plus Alpha sorry acceleration + + align:start position:0% +a 2 * RT plus Alpha sorry acceleration + + + align:start position:0% +a 2 * RT plus Alpha sorry acceleration +time delta T Square it's just written + + align:start position:0% +time delta T Square it's just written + + + align:start position:0% +time delta T Square it's just written +here and then rearrange the terms but + + align:start position:0% +here and then rearrange the terms but + + + align:start position:0% +here and then rearrange the terms but +you see this is the verlet algorithm now + + align:start position:0% +you see this is the verlet algorithm now + + + align:start position:0% +you see this is the verlet algorithm now +what we have when we look at this + + align:start position:0% +what we have when we look at this + + + align:start position:0% +what we have when we look at this +expression we have an expression that + + align:start position:0% +expression we have an expression that + + + align:start position:0% +expression we have an expression that +tells us what is the position at my new + + align:start position:0% +tells us what is the position at my new + + + align:start position:0% +tells us what is the position at my new +time step knowing the position at my + + align:start position:0% +time step knowing the position at my + + + align:start position:0% +time step knowing the position at my +current instant knowing the position at + + align:start position:0% +current instant knowing the position at + + + align:start position:0% +current instant knowing the position at +the previous instant we are sort of + + align:start position:0% +the previous instant we are sort of + + + align:start position:0% +the previous instant we are sort of +keeping configurations from our + + align:start position:0% +keeping configurations from our + + + align:start position:0% +keeping configurations from our +trajectories so we know where we were + + align:start position:0% +trajectories so we know where we were + + + align:start position:0% +trajectories so we know where we were +before we know where we are now and we + + align:start position:0% +before we know where we are now and we + + + align:start position:0% +before we know where we are now and we +know where we are going to be just by + + align:start position:0% +know where we are going to be just by + + + align:start position:0% +know where we are going to be just by +adding to this the term acceleration at + + align:start position:0% +adding to this the term acceleration at + + + align:start position:0% +adding to this the term acceleration at +the present times times Delta t s we + + align:start position:0% +the present times times Delta t s we + + + align:start position:0% +the present times times Delta t s we +make an error because we are not + + align:start position:0% +make an error because we are not + + + align:start position:0% +make an error because we are not +introducing terms + + align:start position:0% +introducing terms + + + align:start position:0% +introducing terms +that are higher order in delta T squ but + + align:start position:0% +that are higher order in delta T squ but + + + align:start position:0% +that are higher order in delta T squ but +you see the term in delta T Cube has + + align:start position:0% +you see the term in delta T Cube has + + + align:start position:0% +you see the term in delta T Cube has +cancelled out so the error that we make + + align:start position:0% +cancelled out so the error that we make + + + align:start position:0% +cancelled out so the error that we make +is just of the order Delta T4 that is + + align:start position:0% +is just of the order Delta T4 that is + + + align:start position:0% +is just of the order Delta T4 that is +that means that the smaller we make the + + align:start position:0% +that means that the smaller we make the + + + align:start position:0% +that means that the smaller we make the +delta T the smaller we make the time + + align:start position:0% +delta T the smaller we make the time + + + align:start position:0% +delta T the smaller we make the time +step the more accurate our integration + + align:start position:0% +step the more accurate our integration + + + align:start position:0% +step the more accurate our integration +is and so this is if you want the most + + align:start position:0% +is and so this is if you want the most + + + align:start position:0% +is and so this is if you want the most +critical parameter in your molecular + + align:start position:0% +critical parameter in your molecular + + + align:start position:0% +critical parameter in your molecular +Dynamic simulation you need to make sure + + align:start position:0% +Dynamic simulation you need to make sure + + + align:start position:0% +Dynamic simulation you need to make sure +that the step steps that you take are + + align:start position:0% +that the step steps that you take are + + + align:start position:0% +that the step steps that you take are +small enough considering what is really + + align:start position:0% +small enough considering what is really + + + align:start position:0% +small enough considering what is really +the variation of your Force as a + + align:start position:0% +the variation of your Force as a + + + align:start position:0% +the variation of your Force as a +function of time because remember that + + align:start position:0% +function of time because remember that + + + align:start position:0% +function of time because remember that +you know now we use Newton's equation of + + align:start position:0% +you know now we use Newton's equation of + + + align:start position:0% +you know now we use Newton's equation of +motion the acceleration at a time T is + + align:start position:0% +motion the acceleration at a time T is + + + align:start position:0% +motion the acceleration at a time T is +just given by the mass the force divided + + align:start position:0% +just given by the mass the force divided + + + align:start position:0% +just given by the mass the force divided +by the mass and because the force is + + align:start position:0% +by the mass and because the force is + + + align:start position:0% +by the mass and because the force is +just the gradient of the potential is + + align:start position:0% +just the gradient of the potential is + + + align:start position:0% +just the gradient of the potential is +just given by this so at a certain in in + + align:start position:0% +just given by this so at a certain in in + + + align:start position:0% +just given by this so at a certain in in +time T you have the acceleration acting + + align:start position:0% +time T you have the acceleration acting + + + align:start position:0% +time T you have the acceleration acting +in your particles just by taking the + + align:start position:0% +in your particles just by taking the + + + align:start position:0% +in your particles just by taking the +force and dividing by the mass so at + + align:start position:0% +force and dividing by the mass so at + + + align:start position:0% +force and dividing by the mass so at +every instant you calculate force and + + align:start position:0% +every instant you calculate force and + + + align:start position:0% +every instant you calculate force and +the force lets you evolve the system and + + align:start position:0% +the force lets you evolve the system and + + + align:start position:0% +the force lets you evolve the system and +it keeps giving you the new positions + + align:start position:0% +it keeps giving you the new positions + + + align:start position:0% +it keeps giving you the new positions +and so you know what is the trajectory + + align:start position:0% +and so you know what is the trajectory + + + align:start position:0% +and so you know what is the trajectory +in configuration space and you can very + + align:start position:0% +in configuration space and you can very + + + align:start position:0% +in configuration space and you can very +simply find out what is your velocity at + + align:start position:0% +simply find out what is your velocity at + + + align:start position:0% +simply find out what is your velocity at +every instant T if you need to calculate + + align:start position:0% +every instant T if you need to calculate + + + align:start position:0% +every instant T if you need to calculate +what is the velocity just by you know + + align:start position:0% +what is the velocity just by you know + + + align:start position:0% +what is the velocity just by you know +doing doing a finite difference + + align:start position:0% +doing doing a finite difference + + + align:start position:0% +doing doing a finite difference +calculation of the tangent basically the + + align:start position:0% +calculation of the tangent basically the + + + align:start position:0% +calculation of the tangent basically the +velocity is the tangent of the + + align:start position:0% +velocity is the tangent of the + + + align:start position:0% +velocity is the tangent of the +trajectory with respect to T okay this + + align:start position:0% +trajectory with respect to T okay this + + + align:start position:0% +trajectory with respect to T okay this +concludes class uh sort of what we'll + + align:start position:0% +concludes class uh sort of what we'll + + + align:start position:0% +concludes class uh sort of what we'll +see in the next lecture is how we + + align:start position:0% +see in the next lecture is how we + + + align:start position:0% +see in the next lecture is how we +actually sort of you know take this + + align:start position:0% +actually sort of you know take this + + + align:start position:0% +actually sort of you know take this +verlet integration and how we use it to + + align:start position:0% +verlet integration and how we use it to + + + align:start position:0% +verlet integration and how we use it to +do the characterization of the + + align:start position:0% +do the characterization of the + + + align:start position:0% +do the characterization of the +thermodynamical properties of a real + + align:start position:0% +thermodynamical properties of a real + + + align:start position:0% +thermodynamical properties of a real +system so um today is Thursday next week + + align:start position:0% +system so um today is Thursday next week + + + align:start position:0% +system so um today is Thursday next week +is spring break so we'll see each other + + align:start position:0% +is spring break so we'll see each other + + + align:start position:0% +is spring break so we'll see each other +again on uh Tuesday + + align:start position:0% +again on uh Tuesday + + + align:start position:0% +again on uh Tuesday +29th and + + align:start position:0% +29th and + + + align:start position:0% +29th and +um I will be at a conference and all the + + align:start position:0% +um I will be at a conference and all the + + + align:start position:0% +um I will be at a conference and all the +Tas will be at a conference next week so + + align:start position:0% +Tas will be at a conference next week so + + + align:start position:0% +Tas will be at a conference next week so +it will be slightly difficult + + align:start position:0% +it will be slightly difficult + + + align:start position:0% +it will be slightly difficult +communicating via email so try to ask a + + align:start position:0% +communicating via email so try to ask a + + + align:start position:0% +communicating via email so try to ask a +lot of questions between now and Sunday + + align:start position:0% +lot of questions between now and Sunday + + + align:start position:0% +lot of questions between now and Sunday +for your problem set that is due the + + align:start position:0% +for your problem set that is due the + + + align:start position:0% +for your problem set that is due the +Tuesday after spring break and that will + + align:start position:0% +Tuesday after spring break and that will + + + align:start position:0% +Tuesday after spring break and that will +be problem set + + align:start position:0% +be problem set + + + align:start position:0% +be problem set +too otherwise enjoy spring break \ No newline at end of file diff --git a/gj8RoTm9jxM.txt b/gj8RoTm9jxM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c6332e4f5a82e814cd57bc110400cd9d8dd54685 --- /dev/null +++ b/gj8RoTm9jxM.txt @@ -0,0 +1,1291 @@ +align:start position:0% + +you okay + + align:start position:0% +you okay + + + align:start position:0% +you okay +good morning and welcome thank you for + + align:start position:0% +good morning and welcome thank you for + + + align:start position:0% +good morning and welcome thank you for +agreeing to meet with me to serve on + + align:start position:0% +agreeing to meet with me to serve on + + + align:start position:0% +agreeing to meet with me to serve on +this advisory group to develop a + + align:start position:0% +this advisory group to develop a + + + align:start position:0% +this advisory group to develop a +regional water strategy for metropolitan + + align:start position:0% +regional water strategy for metropolitan + + + align:start position:0% +regional water strategy for metropolitan +area I've called this meeting to give + + align:start position:0% +area I've called this meeting to give + + + align:start position:0% +area I've called this meeting to give +you my advice for how to proceed in this + + align:start position:0% +you my advice for how to proceed in this + + + align:start position:0% +you my advice for how to proceed in this +process during this meeting I will first + + align:start position:0% +process during this meeting I will first + + + align:start position:0% +process during this meeting I will first +clarify our goals in this process then + + align:start position:0% +clarify our goals in this process then + + + align:start position:0% +clarify our goals in this process then +identify some challenges that I see for + + align:start position:0% +identify some challenges that I see for + + + align:start position:0% +identify some challenges that I see for +and what we stand to lose if we don't + + align:start position:0% +and what we stand to lose if we don't + + + align:start position:0% +and what we stand to lose if we don't +conduct this process wisely next I'll + + align:start position:0% +conduct this process wisely next I'll + + + align:start position:0% +conduct this process wisely next I'll +give my thoughts on a strategy to follow + + align:start position:0% +give my thoughts on a strategy to follow + + + align:start position:0% +give my thoughts on a strategy to follow +to reach a sound and politically viable + + align:start position:0% +to reach a sound and politically viable + + + align:start position:0% +to reach a sound and politically viable +regional plan and I'll talk about what I + + align:start position:0% +regional plan and I'll talk about what I + + + align:start position:0% +regional plan and I'll talk about what I +think success in this process would look + + align:start position:0% +think success in this process would look + + + align:start position:0% +think success in this process would look +like for you to keep in mind + + align:start position:0% +like for you to keep in mind + + + align:start position:0% +like for you to keep in mind +prospectively as you carry out the + + align:start position:0% +prospectively as you carry out the + + + align:start position:0% +prospectively as you carry out the +planning process so our goal is to + + align:start position:0% +planning process so our goal is to + + + align:start position:0% +planning process so our goal is to +develop a strategy for administering + + align:start position:0% +develop a strategy for administering + + + align:start position:0% +develop a strategy for administering +water that balances and to whatever + + align:start position:0% +water that balances and to whatever + + + align:start position:0% +water that balances and to whatever +extent possible actually meets the needs + + align:start position:0% +extent possible actually meets the needs + + + align:start position:0% +extent possible actually meets the needs +of the diverse stakeholders from the + + align:start position:0% +of the diverse stakeholders from the + + + align:start position:0% +of the diverse stakeholders from the +industrial residential agricultural and + + align:start position:0% +industrial residential agricultural and + + + align:start position:0% +industrial residential agricultural and +conservation sectors as well as our + + align:start position:0% +conservation sectors as well as our + + + align:start position:0% +conservation sectors as well as our +partners in government I also believe + + align:start position:0% +partners in government I also believe + + + align:start position:0% +partners in government I also believe +that a second but still important goal + + align:start position:0% +that a second but still important goal + + + align:start position:0% +that a second but still important goal +is to get through this process in a way + + align:start position:0% +is to get through this process in a way + + + align:start position:0% +is to get through this process in a way +that this diverse group of stakeholders + + align:start position:0% +that this diverse group of stakeholders + + + align:start position:0% +that this diverse group of stakeholders +feels good about the process they took + + align:start position:0% +feels good about the process they took + + + align:start position:0% +feels good about the process they took +part in has learned from it and thus is + + align:start position:0% +part in has learned from it and thus is + + + align:start position:0% +part in has learned from it and thus is +encouraged to and has a skill set to + + align:start position:0% +encouraged to and has a skill set to + + + align:start position:0% +encouraged to and has a skill set to +collaborate again in the future as you + + align:start position:0% +collaborate again in the future as you + + + align:start position:0% +collaborate again in the future as you +know we face some challenges to + + align:start position:0% +know we face some challenges to + + + align:start position:0% +know we face some challenges to +developing this plan with current + + align:start position:0% +developing this plan with current + + + align:start position:0% +developing this plan with current +distribution and use water supplies are + + align:start position:0% +distribution and use water supplies are + + + align:start position:0% +distribution and use water supplies are +tight and are insufficient to meet the + + align:start position:0% +tight and are insufficient to meet the + + + align:start position:0% +tight and are insufficient to meet the +needs of development that we hope will + + align:start position:0% +needs of development that we hope will + + + align:start position:0% +needs of development that we hope will +return to our region with economic + + align:start position:0% +return to our region with economic + + + align:start position:0% +return to our region with economic +rebound if we don't develop a strategy + + align:start position:0% +rebound if we don't develop a strategy + + + align:start position:0% +rebound if we don't develop a strategy +to as far as possible meet the needs of + + align:start position:0% +to as far as possible meet the needs of + + + align:start position:0% +to as far as possible meet the needs of +all the stakeholder groups involved we + + align:start position:0% +all the stakeholder groups involved we + + + align:start position:0% +all the stakeholder groups involved we +will see rising conflict that could + + align:start position:0% +will see rising conflict that could + + + align:start position:0% +will see rising conflict that could +really strain the relationships in this + + align:start position:0% +really strain the relationships in this + + + align:start position:0% +really strain the relationships in this +community and ultimately tear it apart + + align:start position:0% +community and ultimately tear it apart + + + align:start position:0% +community and ultimately tear it apart +I'm also concerned that if we don't act + + align:start position:0% +I'm also concerned that if we don't act + + + align:start position:0% +I'm also concerned that if we don't act +wisely and proceed in a way that + + align:start position:0% +wisely and proceed in a way that + + + align:start position:0% +wisely and proceed in a way that +everyone is on board with our process + + align:start position:0% +everyone is on board with our process + + + align:start position:0% +everyone is on board with our process +could be undermined who my parties who + + align:start position:0% +could be undermined who my parties who + + + align:start position:0% +could be undermined who my parties who +feel disenfranchised or who don't want + + align:start position:0% +feel disenfranchised or who don't want + + + align:start position:0% +feel disenfranchised or who don't want +to collaborate on a solution so how do + + align:start position:0% +to collaborate on a solution so how do + + + align:start position:0% +to collaborate on a solution so how do +we navigate this delicate task with our + + align:start position:0% +we navigate this delicate task with our + + + align:start position:0% +we navigate this delicate task with our +eyes open to arrive at a sound solution + + align:start position:0% +eyes open to arrive at a sound solution + + + align:start position:0% +eyes open to arrive at a sound solution +I'm very confident in your abilities and + + align:start position:0% +I'm very confident in your abilities and + + + align:start position:0% +I'm very confident in your abilities and +those are the experts that you tap to + + align:start position:0% +those are the experts that you tap to + + + align:start position:0% +those are the experts that you tap to +make sound judgments about a plan to + + align:start position:0% +make sound judgments about a plan to + + + align:start position:0% +make sound judgments about a plan to +share and distribute the water but I + + align:start position:0% +share and distribute the water but I + + + align:start position:0% +share and distribute the water but I +don't want you just to rely on expertise + + align:start position:0% +don't want you just to rely on expertise + + + align:start position:0% +don't want you just to rely on expertise +to engineer the best solution to this + + align:start position:0% +to engineer the best solution to this + + + align:start position:0% +to engineer the best solution to this +problem I want the a plan that is + + align:start position:0% +problem I want the a plan that is + + + align:start position:0% +problem I want the a plan that is +developed to be the result of an + + align:start position:0% +developed to be the result of an + + + align:start position:0% +developed to be the result of an +informed + + align:start position:0% +informed + + + align:start position:0% +informed +that has the backing of everybody needed + + align:start position:0% +that has the backing of everybody needed + + + align:start position:0% +that has the backing of everybody needed +to implement it political viability is + + align:start position:0% +to implement it political viability is + + + align:start position:0% +to implement it political viability is +one key factor we need an an expert + + align:start position:0% +one key factor we need an an expert + + + align:start position:0% +one key factor we need an an expert +solution won't necessarily get us there + + align:start position:0% +solution won't necessarily get us there + + + align:start position:0% +solution won't necessarily get us there +you have been selected to be part of + + align:start position:0% +you have been selected to be part of + + + align:start position:0% +you have been selected to be part of +this advisory group because of your + + align:start position:0% +this advisory group because of your + + + align:start position:0% +this advisory group because of your +expertise and credibility to deal with + + align:start position:0% +expertise and credibility to deal with + + + align:start position:0% +expertise and credibility to deal with +this policy and decision making effort + + align:start position:0% +this policy and decision making effort + + + align:start position:0% +this policy and decision making effort +you have the authority to convene a + + align:start position:0% +you have the authority to convene a + + + align:start position:0% +you have the authority to convene a +credible process however I think we will + + align:start position:0% +credible process however I think we will + + + align:start position:0% +credible process however I think we will +end up with a stronger and more + + align:start position:0% +end up with a stronger and more + + + align:start position:0% +end up with a stronger and more +politically viable solution if we + + align:start position:0% +politically viable solution if we + + + align:start position:0% +politically viable solution if we +directly involve stakeholders who we see + + align:start position:0% +directly involve stakeholders who we see + + + align:start position:0% +directly involve stakeholders who we see +is likely to be in conflict over the + + align:start position:0% +is likely to be in conflict over the + + + align:start position:0% +is likely to be in conflict over the +decision making effort I suggest you + + align:start position:0% +decision making effort I suggest you + + + align:start position:0% +decision making effort I suggest you +bring in a professional neutral + + align:start position:0% +bring in a professional neutral + + + align:start position:0% +bring in a professional neutral +facilitator who can aid in involving + + align:start position:0% +facilitator who can aid in involving + + + align:start position:0% +facilitator who can aid in involving +stakeholders in the proposal generating + + align:start position:0% +stakeholders in the proposal generating + + + align:start position:0% +stakeholders in the proposal generating +process and who could help solidify + + align:start position:0% +process and who could help solidify + + + align:start position:0% +process and who could help solidify +participants confidence in the + + align:start position:0% +participants confidence in the + + + align:start position:0% +participants confidence in the +neutrality of the process since + + align:start position:0% +neutrality of the process since + + + align:start position:0% +neutrality of the process since +disagreements are likely to be + + align:start position:0% +disagreements are likely to be + + + align:start position:0% +disagreements are likely to be +politically charged here's how I suggest + + align:start position:0% +politically charged here's how I suggest + + + align:start position:0% +politically charged here's how I suggest +you proceed hire an experienced neutral + + align:start position:0% +you proceed hire an experienced neutral + + + align:start position:0% +you proceed hire an experienced neutral +as I said begin by conducting situation + + align:start position:0% +as I said begin by conducting situation + + + align:start position:0% +as I said begin by conducting situation +assessment this means meeting with + + align:start position:0% +assessment this means meeting with + + + align:start position:0% +assessment this means meeting with +representatives of each of the + + align:start position:0% +representatives of each of the + + + align:start position:0% +representatives of each of the +stakeholder groups I previously + + align:start position:0% +stakeholder groups I previously + + + align:start position:0% +stakeholder groups I previously +mentioned and anyone else who thinks + + align:start position:0% +mentioned and anyone else who thinks + + + align:start position:0% +mentioned and anyone else who thinks +they should be included in the process + + align:start position:0% +they should be included in the process + + + align:start position:0% +they should be included in the process +and discuss with them what their needs + + align:start position:0% +and discuss with them what their needs + + + align:start position:0% +and discuss with them what their needs +are for water what their interests are + + align:start position:0% +are for water what their interests are + + + align:start position:0% +are for water what their interests are +and how they'd like to see a regional + + align:start position:0% +and how they'd like to see a regional + + + align:start position:0% +and how they'd like to see a regional +plan develop after you've conducted that + + align:start position:0% +plan develop after you've conducted that + + + align:start position:0% +plan develop after you've conducted that +assessment distill down the results of + + align:start position:0% +assessment distill down the results of + + + align:start position:0% +assessment distill down the results of +your research and communicate to the + + align:start position:0% +your research and communicate to the + + + align:start position:0% +your research and communicate to the +public the parameters of the problem and + + align:start position:0% +public the parameters of the problem and + + + align:start position:0% +public the parameters of the problem and +what are some of the preliminary avenues + + align:start position:0% +what are some of the preliminary avenues + + + align:start position:0% +what are some of the preliminary avenues +that could be pursued to reach a plan + + align:start position:0% +that could be pursued to reach a plan + + + align:start position:0% +that could be pursued to reach a plan +ask stakeholder groups to select + + align:start position:0% +ask stakeholder groups to select + + + align:start position:0% +ask stakeholder groups to select +representatives to versus participate in + + align:start position:0% +representatives to versus participate in + + + align:start position:0% +representatives to versus participate in +a formal consensus building process + + align:start position:0% +a formal consensus building process + + + align:start position:0% +a formal consensus building process +conduct joint fact-finding about uses of + + align:start position:0% +conduct joint fact-finding about uses of + + + align:start position:0% +conduct joint fact-finding about uses of +and needs for water in the region and + + align:start position:0% +and needs for water in the region and + + + align:start position:0% +and needs for water in the region and +help participants explore strategies + + align:start position:0% +help participants explore strategies + + + align:start position:0% +help participants explore strategies +that conceptualize water as a flexible + + align:start position:0% +that conceptualize water as a flexible + + + align:start position:0% +that conceptualize water as a flexible +resource where can meet multiple group's + + align:start position:0% +resource where can meet multiple group's + + + align:start position:0% +resource where can meet multiple group's +needs simultaneously here you can bring + + align:start position:0% +needs simultaneously here you can bring + + + align:start position:0% +needs simultaneously here you can bring +in your own expertise and by all means + + align:start position:0% +in your own expertise and by all means + + + align:start position:0% +in your own expertise and by all means +we want everyone to agree together on + + align:start position:0% +we want everyone to agree together on + + + align:start position:0% +we want everyone to agree together on +the facts that we're going to use to + + align:start position:0% +the facts that we're going to use to + + + align:start position:0% +the facts that we're going to use to +make the recommendations together invent + + align:start position:0% +make the recommendations together invent + + + align:start position:0% +make the recommendations together invent +options based on the results of the + + align:start position:0% +options based on the results of the + + + align:start position:0% +options based on the results of the +information gathering help participants + + align:start position:0% +information gathering help participants + + + align:start position:0% +information gathering help participants +in the process find ways to add value to + + align:start position:0% +in the process find ways to add value to + + + align:start position:0% +in the process find ways to add value to +the resources you're dealing with and + + align:start position:0% +the resources you're dealing with and + + + align:start position:0% +the resources you're dealing with and +invent mutually acceptable solutions if + + align:start position:0% +invent mutually acceptable solutions if + + + align:start position:0% +invent mutually acceptable solutions if +necessary bring other issues besides + + align:start position:0% +necessary bring other issues besides + + + align:start position:0% +necessary bring other issues besides +water to the table these groups + + align:start position:0% +water to the table these groups + + + align:start position:0% +water to the table these groups +intersect and overlap in a number of + + align:start position:0% +intersect and overlap in a number of + + + align:start position:0% +intersect and overlap in a number of +areas that affect our planning strategy + + align:start position:0% +areas that affect our planning strategy + + + align:start position:0% +areas that affect our planning strategy +and it might be that if we add in + + align:start position:0% +and it might be that if we add in + + + align:start position:0% +and it might be that if we add in +other ingredients were able to package + + align:start position:0% +other ingredients were able to package + + + align:start position:0% +other ingredients were able to package +solutions that are more acceptable to + + align:start position:0% +solutions that are more acceptable to + + + align:start position:0% +solutions that are more acceptable to +everyone excuse me + + align:start position:0% +everyone excuse me + + + align:start position:0% +everyone excuse me +help representatives caucus the various + + align:start position:0% +help representatives caucus the various + + + align:start position:0% +help representatives caucus the various +options where there consists + + align:start position:0% +options where there consists + + + align:start position:0% +options where there consists +constituencies and clarify their + + align:start position:0% +constituencies and clarify their + + + align:start position:0% +constituencies and clarify their +interests and needs and help them + + align:start position:0% +interests and needs and help them + + + align:start position:0% +interests and needs and help them +package options together in a way that + + align:start position:0% +package options together in a way that + + + align:start position:0% +package options together in a way that +everyone can agree to and knock them all + + align:start position:0% +everyone can agree to and knock them all + + + align:start position:0% +everyone can agree to and knock them all +endorse an agreement for a strategy and + + align:start position:0% +endorse an agreement for a strategy and + + + align:start position:0% +endorse an agreement for a strategy and +then they will turn that recommendation + + align:start position:0% +then they will turn that recommendation + + + align:start position:0% +then they will turn that recommendation +over to you to formalize and then that's + + align:start position:0% +over to you to formalize and then that's + + + align:start position:0% +over to you to formalize and then that's +what we would implement after we engage + + align:start position:0% +what we would implement after we engage + + + align:start position:0% +what we would implement after we engage +in this process how will we know that + + align:start position:0% +in this process how will we know that + + + align:start position:0% +in this process how will we know that +we've succeeded all groups can sign on + + align:start position:0% +we've succeeded all groups can sign on + + + align:start position:0% +we've succeeded all groups can sign on +to the agreement and all agree that it + + align:start position:0% +to the agreement and all agree that it + + + align:start position:0% +to the agreement and all agree that it +is better about an arrangement than + + align:start position:0% +is better about an arrangement than + + + align:start position:0% +is better about an arrangement than +having an agreement at all and + + align:start position:0% +having an agreement at all and + + + align:start position:0% +having an agreement at all and +participating groups will have learned + + align:start position:0% +participating groups will have learned + + + align:start position:0% +participating groups will have learned +about each other's needs and each other + + align:start position:0% +about each other's needs and each other + + + align:start position:0% +about each other's needs and each other +in a way that they can see that coming + + align:start position:0% +in a way that they can see that coming + + + align:start position:0% +in a way that they can see that coming +to consensus is not necessarily a + + align:start position:0% +to consensus is not necessarily a + + + align:start position:0% +to consensus is not necessarily a +zero-sum game I think that this is the + + align:start position:0% +zero-sum game I think that this is the + + + align:start position:0% +zero-sum game I think that this is the +best strategy not only because + + align:start position:0% +best strategy not only because + + + align:start position:0% +best strategy not only because +collaboration improves the quality of + + align:start position:0% +collaboration improves the quality of + + + align:start position:0% +collaboration improves the quality of +the decision but it also makes it more + + align:start position:0% +the decision but it also makes it more + + + align:start position:0% +the decision but it also makes it more +implementable it should help neutralize + + align:start position:0% +implementable it should help neutralize + + + align:start position:0% +implementable it should help neutralize +the process politically if it has + + align:start position:0% +the process politically if it has + + + align:start position:0% +the process politically if it has +extremely widespread support both the + + align:start position:0% +extremely widespread support both the + + + align:start position:0% +extremely widespread support both the +media and the state government who have + + align:start position:0% +media and the state government who have + + + align:start position:0% +media and the state government who have +been less than favorable about + + align:start position:0% +been less than favorable about + + + align:start position:0% +been less than favorable about +developing a regional water plan would + + align:start position:0% +developing a regional water plan would + + + align:start position:0% +developing a regional water plan would +have a hard time criticizing it if + + align:start position:0% +have a hard time criticizing it if + + + align:start position:0% +have a hard time criticizing it if +everyone really backs it up this has + + align:start position:0% +everyone really backs it up this has + + + align:start position:0% +everyone really backs it up this has +been a brief overview and I'm happy to + + align:start position:0% +been a brief overview and I'm happy to + + + align:start position:0% +been a brief overview and I'm happy to +address questions and discuss in more + + align:start position:0% +address questions and discuss in more + + + align:start position:0% +address questions and discuss in more +detail + + align:start position:0% +detail + + + align:start position:0% +detail +[Applause] \ No newline at end of file diff --git a/hMUpevQzNzY.txt b/hMUpevQzNzY.txt new file mode 100644 index 0000000000000000000000000000000000000000..c9705efea3336dc8bbe48ec68bfd60156f1a7b11 --- /dev/null +++ b/hMUpevQzNzY.txt @@ -0,0 +1,8083 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right so we're doing uh + + align:start position:0% +ocw.mit.edu all right so we're doing uh + + + align:start position:0% +ocw.mit.edu all right so we're doing uh +lecture 06 in the course today that's in + + align:start position:0% +lecture 06 in the course today that's in + + + align:start position:0% +lecture 06 in the course today that's in +the just remind people it's in the docs + + align:start position:0% +the just remind people it's in the docs + + + align:start position:0% +the just remind people it's in the docs +directory + + align:start position:0% +directory + + + align:start position:0% +directory +here + + align:start position:0% +here + + + align:start position:0% +here +and we're going to be doing a lot + + align:start position:0% +and we're going to be doing a lot + + + align:start position:0% +and we're going to be doing a lot +talking about a particular application + + align:start position:0% +talking about a particular application + + + align:start position:0% +talking about a particular application +which I think is actually representative + + align:start position:0% +which I think is actually representative + + + align:start position:0% +which I think is actually representative +of a variety of applications that we do + + align:start position:0% +of a variety of applications that we do + + + align:start position:0% +of a variety of applications that we do +a lot of things similar statistical + + align:start position:0% +a lot of things similar statistical + + + align:start position:0% +a lot of things similar statistical +properties + + align:start position:0% +properties + + + align:start position:0% +properties +sequence cross + + align:start position:0% +sequence cross + + + align:start position:0% +sequence cross +correlation okay so um + + align:start position:0% +correlation okay so um + + + align:start position:0% +correlation okay so um +diving right + + align:start position:0% +diving right + + + align:start position:0% +diving right +in just going to give an introduction to + + align:start position:0% +in just going to give an introduction to + + + align:start position:0% +in just going to give an introduction to +this particular problem of genetic + + align:start position:0% +this particular problem of genetic + + + align:start position:0% +this particular problem of genetic +sequence analysis from a computational + + align:start position:0% +sequence analysis from a computational + + + align:start position:0% +sequence analysis from a computational +perspective + + align:start position:0% +perspective + + + align:start position:0% +perspective +um and how the d4m technology can really + + align:start position:0% +um and how the d4m technology can really + + + align:start position:0% +um and how the d4m technology can really +make it uh pretty pretty easy to do the + + align:start position:0% +make it uh pretty pretty easy to do the + + + align:start position:0% +make it uh pretty pretty easy to do the +kinds of things that people like to do + + align:start position:0% +kinds of things that people like to do + + + align:start position:0% +kinds of things that people like to do +and then just talk about the pipeline + + align:start position:0% +and then just talk about the pipeline + + + align:start position:0% +and then just talk about the pipeline +that we implemented to implement this + + align:start position:0% +that we implemented to implement this + + + align:start position:0% +that we implemented to implement this +system because as I've said + + align:start position:0% +system because as I've said + + + align:start position:0% +system because as I've said +before um when you're dealing with this + + align:start position:0% +before um when you're dealing with this + + + align:start position:0% +before um when you're dealing with this +type of large data the deform technology + + align:start position:0% +type of large data the deform technology + + + align:start position:0% +type of large data the deform technology +is one piece it's often the piece you + + align:start position:0% +is one piece it's often the piece you + + + align:start position:0% +is one piece it's often the piece you +use to prototype your algorithms + + align:start position:0% +use to prototype your algorithms + + + align:start position:0% +use to prototype your algorithms +but to be a part of a system you usually + + align:start position:0% +but to be a part of a system you usually + + + align:start position:0% +but to be a part of a system you usually +have to stitch together a variety of + + align:start position:0% +have to stitch together a variety of + + + align:start position:0% +have to stitch together a variety of +Technologies databases obviously being + + align:start position:0% +Technologies databases obviously being + + + align:start position:0% +Technologies databases obviously being +an important part of + + align:start position:0% + + + + align:start position:0% + +that so this is a great chart this is uh + + align:start position:0% +that so this is a great chart this is uh + + + align:start position:0% +that so this is a great chart this is uh +this is the uh relative cost per DNA + + align:start position:0% +this is the uh relative cost per DNA + + + align:start position:0% +this is the uh relative cost per DNA +sequence over time here over the last uh + + align:start position:0% +sequence over time here over the last uh + + + align:start position:0% +sequence over time here over the last uh +uh 20 years uh so we're getting a little + + align:start position:0% +uh 20 years uh so we're getting a little + + + align:start position:0% +uh 20 years uh so we're getting a little +cut off here at the bottom of the screen + + align:start position:0% +cut off here at the bottom of the screen + + + align:start position:0% +cut off here at the bottom of the screen +so I think + + align:start position:0% +so I think + + + align:start position:0% +so I think +I'm so um uh you know this just shows + + align:start position:0% +I'm so um uh you know this just shows + + + align:start position:0% +I'm so um uh you know this just shows +Moore's Law so we all know that that + + align:start position:0% +Moore's Law so we all know that that + + + align:start position:0% +Moore's Law so we all know that that +technology has been increasing at an + + align:start position:0% +technology has been increasing at an + + + align:start position:0% +technology has been increasing at an +incredible rate and as we've seen uh the + + align:start position:0% +incredible rate and as we've seen uh the + + + align:start position:0% +incredible rate and as we've seen uh the +cost of uh DNA sequencing is going down + + align:start position:0% +cost of uh DNA sequencing is going down + + + align:start position:0% +cost of uh DNA sequencing is going down +dramatically so the first DNA + + align:start position:0% +dramatically so the first DNA + + + align:start position:0% +dramatically so the first DNA +sequence you know people nominally say + + align:start position:0% +sequence you know people nominally say + + + align:start position:0% +sequence you know people nominally say +it to to to sequence the first human + + align:start position:0% +it to to to sequence the first human + + + align:start position:0% +it to to to sequence the first human +genome was around a billion + + align:start position:0% +genome was around a billion + + + align:start position:0% +genome was around a billion +dollars and + + align:start position:0% +dollars and + + + align:start position:0% +dollars and +um they're expecting it to be + + align:start position:0% +um they're expecting it to be + + + align:start position:0% +um they're expecting it to be +$100 within the next few years so having + + align:start position:0% +$100 within the next few years so having + + + align:start position:0% +$100 within the next few years so having +your DNA + + align:start position:0% +your DNA + + + align:start position:0% +your DNA +sequenced will become probably a fairly + + align:start position:0% +sequenced will become probably a fairly + + + align:start position:0% +sequenced will become probably a fairly +routine + + align:start position:0% +routine + + + align:start position:0% +routine +medical uh activity in the next the next + + align:start position:0% +medical uh activity in the next the next + + + align:start position:0% +medical uh activity in the next the next +decade um and so + + align:start position:0% +decade um and so + + + align:start position:0% +decade um and so +uh the data generated you know typically + + align:start position:0% +uh the data generated you know typically + + + align:start position:0% +uh the data generated you know typically +a human genm will have + + align:start position:0% +a human genm will have + + + align:start position:0% +a human genm will have +billions of DNA sequences in it and + + align:start position:0% +billions of DNA sequences in it and + + + align:start position:0% +billions of DNA sequences in it and +that's a lot of + + align:start position:0% +that's a lot of + + + align:start position:0% +that's a lot of +data + + align:start position:0% +data + + + align:start position:0% +data +um what's + + align:start position:0% +um what's + + + align:start position:0% +um what's +actually perhaps even more interesting + + align:start position:0% +actually perhaps even more interesting + + + align:start position:0% +actually perhaps even more interesting +than sequencing your + + align:start position:0% +than sequencing your + + + align:start position:0% +than sequencing your +DNA is sequencing the DNA of all the + + align:start position:0% +DNA is sequencing the DNA of all the + + + align:start position:0% +DNA is sequencing the DNA of all the +other things that are in you which is + + align:start position:0% +other things that are in you which is + + + align:start position:0% +other things that are in you which is +sometimes called the metagenome so + + align:start position:0% +sometimes called the metagenome so + + + align:start position:0% +sometimes called the metagenome so +take a swab and not just + + align:start position:0% +take a swab and not just + + + align:start position:0% +take a swab and not just +get the DNA your DNA but also of all the + + align:start position:0% +get the DNA your DNA but also of all the + + + align:start position:0% +get the DNA your DNA but also of all the +other things that are a part of you + + align:start position:0% +other things that are a part of you + + + align:start position:0% +other things that are a part of you +which can be 10 times larger than than + + align:start position:0% +which can be 10 times larger than than + + + align:start position:0% +which can be 10 times larger than than +than your DNA so depending on that so + + align:start position:0% +than your DNA so depending on that so + + + align:start position:0% +than your DNA so depending on that so +they now have developed these high + + align:start position:0% +they now have developed these high + + + align:start position:0% +they now have developed these high +volume sequencers here's an example of + + align:start position:0% +volume sequencers here's an example of + + + align:start position:0% +volume sequencers here's an example of +one that I believe can do uh + + align:start position:0% + + + + align:start position:0% + +600 okay no problem that uh 600 uh + + align:start position:0% +600 okay no problem that uh 600 uh + + + align:start position:0% +600 okay no problem that uh 600 uh +billion base pairs a day so like 600 + + align:start position:0% +billion base pairs a day so like 600 + + + align:start position:0% +billion base pairs a day so like 600 +gigabytes of data a day and this is all + + align:start position:0% +gigabytes of data a day and this is all + + + align:start position:0% +gigabytes of data a day and this is all +data that you want to cross-correlate + + align:start position:0% +data that you want to cross-correlate + + + align:start position:0% +data that you want to cross-correlate +you know I mean it's it's your it's it's + + align:start position:0% +you know I mean it's it's your it's it's + + + align:start position:0% +you know I mean it's it's your it's it's +a it's a so that's what this uh this is + + align:start position:0% +a it's a so that's what this uh this is + + + align:start position:0% +a it's a so that's what this uh this is +a this is a + + align:start position:0% +a this is a + + + align:start position:0% +a this is a +tabletop uh tabletop apparatus here that + + align:start position:0% +tabletop uh tabletop apparatus here that + + + align:start position:0% +tabletop uh tabletop apparatus here that +sells for a few + + align:start position:0% +sells for a few + + + align:start position:0% +sells for a few +hundred, and they are even getting into + + align:start position:0% +hundred, and they are even getting into + + + align:start position:0% +hundred, and they are even getting into +you know portable sequencers that you + + align:start position:0% +you know portable sequencers that you + + + align:start position:0% +you know portable sequencers that you +can plug in with a USB connector + + align:start position:0% +can plug in with a USB connector + + + align:start position:0% +can plug in with a USB connector +connection into a laptop or something + + align:start position:0% +connection into a laptop or something + + + align:start position:0% +connection into a laptop or something +like that to do you know more in the + + align:start position:0% +like that to do you know more in the + + + align:start position:0% +like that to do you know more in the +field types of things so why would you + + align:start position:0% +field types of things so why would you + + + align:start position:0% +field types of things so why would you +want to do this um you know uh I think + + align:start position:0% +want to do this um you know uh I think + + + align:start position:0% +want to do this um you know uh I think +you know abstractly you understand all + + align:start position:0% +you know abstractly you understand all + + + align:start position:0% +you know abstractly you understand all +that would be good um um computation + + align:start position:0% +that would be good um um computation + + + align:start position:0% +that would be good um um computation +plays a a huge role because this data is + + align:start position:0% +plays a a huge role because this data is + + + align:start position:0% +plays a a huge role because this data is +collected and it's just sort of abstract + + align:start position:0% +collected and it's just sort of abstract + + + align:start position:0% +collected and it's just sort of abstract +Snippets of DNA you know just even + + align:start position:0% +Snippets of DNA you know just even + + + align:start position:0% +Snippets of DNA you know just even +assembling them into a you know just + + align:start position:0% +assembling them into a you know just + + + align:start position:0% +assembling them into a you know just +your DNA into a whole process can take a + + align:start position:0% +your DNA into a whole process can take a + + + align:start position:0% +your DNA into a whole process can take a +fair amount of + + align:start position:0% +fair amount of + + + align:start position:0% +fair amount of +computation uh and right now that is + + align:start position:0% +computation uh and right now that is + + + align:start position:0% +computation uh and right now that is +actually something that takes a fair + + align:start position:0% +actually something that takes a fair + + + align:start position:0% +actually something that takes a fair +amount of time and so to give you an + + align:start position:0% +amount of time and so to give you an + + + align:start position:0% +amount of time and so to give you an +example here's a great uh use case uh + + align:start position:0% +example here's a great uh use case uh + + + align:start position:0% +example here's a great uh use case uh +this shows If you recall in the summer + + align:start position:0% +this shows If you recall in the summer + + + align:start position:0% +this shows If you recall in the summer +of 2011 there was a violent ecoli + + align:start position:0% +of 2011 there was a violent ecoli + + + align:start position:0% +of 2011 there was a violent ecoli +outbreak in uh in Germany and not to + + align:start position:0% +outbreak in uh in Germany and not to + + + align:start position:0% +outbreak in uh in Germany and not to +single out the Germans we've certainly + + align:start position:0% +single out the Germans we've certainly + + + align:start position:0% +single out the Germans we've certainly +had the same things occur in the United + + align:start position:0% +had the same things occur in the United + + + align:start position:0% +had the same things occur in the United +States and these these occur all across + + align:start position:0% +States and these these occur all across + + + align:start position:0% +States and these these occur all across +across the world and so you know this + + align:start position:0% +across the world and so you know this + + + align:start position:0% +across the world and so you know this +shows kind of the time course of you + + align:start position:0% +shows kind of the time course of you + + + align:start position:0% +shows kind of the time course of you +know in May you know the first cases + + align:start position:0% +know in May you know the first cases + + + align:start position:0% +know in May you know the first cases +starting appear and then those lead to + + align:start position:0% +starting appear and then those lead to + + + align:start position:0% +starting appear and then those lead to +the first deaths and then you know + + align:start position:0% +the first deaths and then you know + + + align:start position:0% +the first deaths and then you know +spikes and then uh you know that's just + + align:start position:0% +spikes and then uh you know that's just + + + align:start position:0% +spikes and then uh you know that's just +kind of when you hit this peak is when + + align:start position:0% +kind of when you hit this peak is when + + + align:start position:0% +kind of when you hit this peak is when +they really identify the outbrook and + + align:start position:0% +they really identify the outbrook and + + + align:start position:0% +they really identify the outbrook and +then they finally figured out what the + + align:start position:0% +then they finally figured out what the + + + align:start position:0% +then they finally figured out what the +uh what what it what it is that that + + align:start position:0% +uh what what it what it is that that + + + align:start position:0% +uh what what it what it is that that +that's causing people and begin to + + align:start position:0% +that's causing people and begin to + + + align:start position:0% +that's causing people and begin to +remediate it but you know until you've + + align:start position:0% +remediate it but you know until you've + + + align:start position:0% +remediate it but you know until you've +kind of really have this portion you + + align:start position:0% +kind of really have this portion you + + + align:start position:0% +kind of really have this portion you +know people are still getting exposed to + + align:start position:0% +know people are still getting exposed to + + + align:start position:0% +know people are still getting exposed to +the thing um usually before they + + align:start position:0% +the thing um usually before they + + + align:start position:0% +the thing um usually before they +actually nail it down um there's lots of + + align:start position:0% +actually nail it down um there's lots of + + + align:start position:0% +actually nail it down um there's lots of +rumors flying around all other parts of + + align:start position:0% +rumors flying around all other parts of + + + align:start position:0% +rumors flying around all other parts of +uh the food chain are + + align:start position:0% +uh the food chain are + + + align:start position:0% +uh the food chain are +disrupted um you know any single time + + align:start position:0% +disrupted um you know any single time + + + align:start position:0% +disrupted um you know any single time +you know a particular product is + + align:start position:0% +you know a particular product is + + + align:start position:0% +you know a particular product is +implicated that's hundreds of millions + + align:start position:0% +implicated that's hundreds of millions + + + align:start position:0% +implicated that's hundreds of millions +of dollars of lost business as people + + align:start position:0% +of dollars of lost business as people + + + align:start position:0% +of dollars of lost business as people +just basically you know they say it's + + align:start position:0% +just basically you know they say it's + + + align:start position:0% +just basically you know they say it's +spinach then everyone stops buying + + align:start position:0% +spinach then everyone stops buying + + + align:start position:0% +spinach then everyone stops buying +spinach for a while uh oh it wasn't + + align:start position:0% +spinach for a while uh oh it wasn't + + + align:start position:0% +spinach for a while uh oh it wasn't +spinach sorry it was something else and + + align:start position:0% +spinach sorry it was something else and + + + align:start position:0% +spinach sorry it was something else and +so that's so there's a there's a dual + + align:start position:0% +so that's so there's a there's a dual + + + align:start position:0% +so that's so there's a there's a dual +dual uh you know so they started by + + align:start position:0% +dual uh you know so they started by + + + align:start position:0% +dual uh you know so they started by +implicating this the Cucumbers but that + + align:start position:0% +implicating this the Cucumbers but that + + + align:start position:0% +implicating this the Cucumbers but that +wasn't quite right they then sequenced + + align:start position:0% +wasn't quite right they then sequenced + + + align:start position:0% +wasn't quite right they then sequenced +the stuff and then they correctly + + align:start position:0% +the stuff and then they correctly + + + align:start position:0% +the stuff and then they correctly +identified it was the Sprouts um at + + align:start position:0% +identified it was the Sprouts um at + + + align:start position:0% +identified it was the Sprouts um at +least I believe that was the time course + + align:start position:0% +least I believe that was the time course + + + align:start position:0% +least I believe that was the time course +of events here so so um and this is sort + + align:start position:0% +of events here so so um and this is sort + + + align:start position:0% +of events here so so um and this is sort +of the integrated number of deaths and + + align:start position:0% +of the integrated number of deaths and + + + align:start position:0% +of the integrated number of deaths and +so you know the story here is obviously + + align:start position:0% +so you know the story here is obviously + + + align:start position:0% +so you know the story here is obviously +thing we want to do most is when a + + align:start position:0% +thing we want to do most is when a + + + align:start position:0% +thing we want to do most is when a +person gets sick here here wouldn't it + + align:start position:0% +person gets sick here here wouldn't it + + + align:start position:0% +person gets sick here here wouldn't it +be great to sequence them immediately + + align:start position:0% +be great to sequence them immediately + + + align:start position:0% +be great to sequence them immediately +get that information know exactly what's + + align:start position:0% +get that information know exactly what's + + + align:start position:0% +get that information know exactly what's +causing the problem and then be able to + + align:start position:0% +causing the problem and then be able to + + + align:start position:0% +causing the problem and then be able to +start testing the the the the food + + align:start position:0% +start testing the the the the food + + + align:start position:0% +start testing the the the the food +supply channel uh so that you can make a + + align:start position:0% +supply channel uh so that you can make a + + + align:start position:0% +supply channel uh so that you can make a +real impact on the mortality and then + + align:start position:0% +real impact on the mortality and then + + + align:start position:0% +real impact on the mortality and then +likewise not have the econom you know + + align:start position:0% +likewise not have the econom you know + + + align:start position:0% +likewise not have the econom you know +obviously the the the the loss of life + + align:start position:0% +obviously the the the the loss of life + + + align:start position:0% +obviously the the the the loss of life +is the uh + + align:start position:0% +is the uh + + + align:start position:0% +is the uh +preeminent uh issue here um but there's + + align:start position:0% +preeminent uh issue here um but there's + + + align:start position:0% +preeminent uh issue here um but there's +also the economic impact which uh + + align:start position:0% +also the economic impact which uh + + + align:start position:0% +also the economic impact which uh +certainly the people who are in those + + align:start position:0% +certainly the people who are in those + + + align:start position:0% +certainly the people who are in those +businesses would want to address so as + + align:start position:0% +businesses would want to address so as + + + align:start position:0% +businesses would want to address so as +you can see there was a really sort of a + + align:start position:0% +you can see there was a really sort of a + + + align:start position:0% +you can see there was a really sort of a +rather long delay here between sort of + + align:start position:0% +rather long delay here between sort of + + + align:start position:0% +rather long delay here between sort of +when the outbreak started and the DNA uh + + align:start position:0% +when the outbreak started and the DNA uh + + + align:start position:0% +when the outbreak started and the DNA uh +sequence uh release and this was + + align:start position:0% +sequence uh release and this was + + + align:start position:0% +sequence uh release and this was +actually um a big step forward in the + + align:start position:0% +actually um a big step forward in the + + + align:start position:0% +actually um a big step forward in the +sense that DNA sequencing really did + + align:start position:0% +sense that DNA sequencing really did + + + align:start position:0% +sense that DNA sequencing really did +play ended up playing a role in this + + align:start position:0% +play ended up playing a role in this + + + align:start position:0% +play ended up playing a role in this +process as opposed to previously where + + align:start position:0% +process as opposed to previously where + + + align:start position:0% +process as opposed to previously where +it may not have um and uh uh uh and the + + align:start position:0% +it may not have um and uh uh uh and the + + + align:start position:0% +it may not have um and uh uh uh and the +and people see that now and they would + + align:start position:0% +and people see that now and they would + + + align:start position:0% +and people see that now and they would +love to move this move this uh this + + align:start position:0% +love to move this move this uh this + + + align:start position:0% +love to move this move this uh this +earlier so you know and and and + + align:start position:0% +earlier so you know and and and + + + align:start position:0% +earlier so you know and and and +obviously in our business and across + + align:start position:0% +obviously in our business and across + + + align:start position:0% +obviously in our business and across +it's not just this type of example but + + align:start position:0% +it's not just this type of example but + + + align:start position:0% +it's not just this type of example but +there's other types of examples where + + align:start position:0% +there's other types of examples where + + + align:start position:0% +there's other types of examples where +rapid uh sequencing and um and + + align:start position:0% +rapid uh sequencing and um and + + + align:start position:0% +rapid uh sequencing and um and +identification would be very important + + align:start position:0% +identification would be very important + + + align:start position:0% +identification would be very important +and there's certainly Investments being + + align:start position:0% +and there's certainly Investments being + + + align:start position:0% +and there's certainly Investments being +made to try and make that more possible + + align:start position:0% +made to try and make that more possible + + + align:start position:0% +made to try and make that more possible +so an example of what the processing + + align:start position:0% +so an example of what the processing + + + align:start position:0% +so an example of what the processing +timeline looks now I mean you have + + align:start position:0% +timeline looks now I mean you have + + + align:start position:0% +timeline looks now I mean you have +basically starting with the human + + align:start position:0% +basically starting with the human + + + align:start position:0% +basically starting with the human +infection you know it could be a natural + + align:start position:0% +infection you know it could be a natural + + + align:start position:0% +infection you know it could be a natural +disease obviously in the dod they're + + align:start position:0% +disease obviously in the dod they're + + + align:start position:0% +disease obviously in the dod they're +very concerned about bioweapons as well + + align:start position:0% +very concerned about bioweapons as well + + + align:start position:0% +very concerned about bioweapons as well +you know so there's the collection of + + align:start position:0% +you know so there's the collection of + + + align:start position:0% +you know so there's the collection of +the sample the preparation the analysis + + align:start position:0% +the sample the preparation the analysis + + + align:start position:0% +the sample the preparation the analysis +and sort of the overall time to + + align:start position:0% +and sort of the overall time to + + + align:start position:0% +and sort of the overall time to +actionable data and really it's not to + + align:start position:0% +actionable data and really it's not to + + + align:start position:0% +actionable data and really it's not to +say processing plays everything on this + + align:start position:0% +say processing plays everything on this + + + align:start position:0% +say processing plays everything on this +but if is part of a whole system you + + align:start position:0% +but if is part of a whole system you + + + align:start position:0% +but if is part of a whole system you +could imagine if you could do on-site + + align:start position:0% +could imagine if you could do on-site + + + align:start position:0% +could imagine if you could do on-site +collection you know automatic + + align:start position:0% +collection you know automatic + + + align:start position:0% +collection you know automatic +preparation and then you know very quick + + align:start position:0% +preparation and then you know very quick + + + align:start position:0% +preparation and then you know very quick +analysis you could imagine shorting this + + align:start position:0% +analysis you could imagine shorting this + + + align:start position:0% +analysis you could imagine shorting this +cycle down to one day which would be you + + align:start position:0% +cycle down to one day which would be you + + + align:start position:0% +cycle down to one day which would be you +know something that would really make a + + align:start position:0% +know something that would really make a + + + align:start position:0% +know something that would really make a +huge impact + + align:start position:0% +huge impact + + + align:start position:0% +huge impact +some of the other uh useful sequences uh + + align:start position:0% +some of the other uh useful sequences uh + + + align:start position:0% +some of the other uh useful sequences uh +useful I'm sorry uh uh roles for DNA + + align:start position:0% +useful I'm sorry uh uh roles for DNA + + + align:start position:0% +useful I'm sorry uh uh roles for DNA +sequence matching is uh you know quickly + + align:start position:0% +sequence matching is uh you know quickly + + + align:start position:0% +sequence matching is uh you know quickly +comparing two data two sets of DNA um um + + align:start position:0% +comparing two data two sets of DNA um um + + + align:start position:0% +comparing two data two sets of DNA um um +um + + align:start position:0% +um + + + align:start position:0% +um +identification um you know that is you + + align:start position:0% +identification um you know that is you + + + align:start position:0% +identification um you know that is you +know who is it um analysis of mixtures + + align:start position:0% +know who is it um analysis of mixtures + + + align:start position:0% +know who is it um analysis of mixtures +you know what what type of things could + + align:start position:0% +you know what what type of things could + + + align:start position:0% +you know what what type of things could +you determine if someone was related to + + align:start position:0% +you determine if someone was related to + + + align:start position:0% +you determine if someone was related to +somebody else um you know ancestry + + align:start position:0% +somebody else um you know ancestry + + + align:start position:0% +somebody else um you know ancestry +analysis which can be used in disease + + align:start position:0% +analysis which can be used in disease + + + align:start position:0% +analysis which can be used in disease +outbreaks criminal investigation + + align:start position:0% +outbreaks criminal investigation + + + align:start position:0% +outbreaks criminal investigation +personal medicine you know the the set + + align:start position:0% +personal medicine you know the the set + + + align:start position:0% +personal medicine you know the the set +of of things is pretty pretty pretty + + align:start position:0% +of of things is pretty pretty pretty + + + align:start position:0% +of of things is pretty pretty pretty +large + + align:start position:0% +large + + + align:start position:0% +large +here so I'm now going to explain to you + + align:start position:0% +here so I'm now going to explain to you + + + align:start position:0% +here so I'm now going to explain to you +kind of fundamentally what is the + + align:start position:0% +kind of fundamentally what is the + + + align:start position:0% +kind of fundamentally what is the +algorithm that we use for doing this + + align:start position:0% +algorithm that we use for doing this + + + align:start position:0% +algorithm that we use for doing this +matching but we're going to explain it + + align:start position:0% +matching but we're going to explain it + + + align:start position:0% +matching but we're going to explain it +in terms of the mathematics that we've + + align:start position:0% +in terms of the mathematics that we've + + + align:start position:0% +in terms of the mathematics that we've +described before which is these + + align:start position:0% +described before which is these + + + align:start position:0% +described before which is these +associative arrays which actually make + + align:start position:0% +associative arrays which actually make + + + align:start position:0% +associative arrays which actually make +it very very easy to describe what's + + align:start position:0% +it very very easy to describe what's + + + align:start position:0% +it very very easy to describe what's +going on here if I was to describe to + + align:start position:0% +going on here if I was to describe to + + + align:start position:0% +going on here if I was to describe to +you the traditional approaches for how + + align:start position:0% +you the traditional approaches for how + + + align:start position:0% +you the traditional approaches for how +we describe DNA sequence matching it + + align:start position:0% +we describe DNA sequence matching it + + + align:start position:0% +we describe DNA sequence matching it +would actually be that would be a whole + + align:start position:0% +would actually be that would be a whole + + + align:start position:0% +would actually be that would be a whole +lecture in + + align:start position:0% +lecture in + + + align:start position:0% +lecture in +Excel so let me get into that algorithm + + align:start position:0% +Excel so let me get into that algorithm + + + align:start position:0% +Excel so let me get into that algorithm +and so basically this is it one slide Is + + align:start position:0% +and so basically this is it one slide Is + + + align:start position:0% +and so basically this is it one slide Is +How We Do DNA sequence matching so we + + align:start position:0% +How We Do DNA sequence matching so we + + + align:start position:0% +How We Do DNA sequence matching so we +have a reference sequence here this is + + align:start position:0% +have a reference sequence here this is + + + align:start position:0% +have a reference sequence here this is +something that we know a database of + + align:start position:0% +something that we know a database of + + + align:start position:0% +something that we know a database of +data that we know and it consists of a + + align:start position:0% +data that we know and it consists of a + + + align:start position:0% +data that we know and it consists of a +sequence ID and then a whole bunch of + + align:start position:0% +sequence ID and then a whole bunch of + + + align:start position:0% +sequence ID and then a whole bunch of +you know what are called base pairs and + + align:start position:0% +you know what are called base pairs and + + + align:start position:0% +you know what are called base pairs and +this can usually be several hundred long + + align:start position:0% +this can usually be several hundred long + + + align:start position:0% +this can usually be several hundred long +and you'll have thousands of these each + + align:start position:0% +and you'll have thousands of these each + + + align:start position:0% +and you'll have thousands of these each +that are a few hundred maybe a thousand + + align:start position:0% +that are a few hundred maybe a thousand + + + align:start position:0% +that are a few hundred maybe a thousand +base pairs long and so the standard + + align:start position:0% +base pairs long and so the standard + + + align:start position:0% +base pairs long and so the standard +approach to this is to take these + + align:start position:0% +approach to this is to take these + + + align:start position:0% +approach to this is to take these +sequences and break them up into smaller + + align:start position:0% +sequences and break them up into smaller + + + align:start position:0% +sequences and break them up into smaller +units which are called words or + + align:start position:0% +units which are called words or + + + align:start position:0% +units which are called words or +Ms and a standard number is called a + + align:start position:0% +Ms and a standard number is called a + + + align:start position:0% +Ms and a standard number is called a +tenr so the basically what you would say + + align:start position:0% +tenr so the basically what you would say + + + align:start position:0% +tenr so the basically what you would say +is you take the first 10 letters and you + + align:start position:0% +is you take the first 10 letters and you + + + align:start position:0% +is you take the first 10 letters and you +say all right that's one + + align:start position:0% +say all right that's one + + + align:start position:0% +say all right that's one +tenur then you move it over one and you + + align:start position:0% +tenur then you move it over one and you + + + align:start position:0% +tenur then you move it over one and you +say that's another 10mer and so on and + + align:start position:0% +say that's another 10mer and so on and + + + align:start position:0% +say that's another 10mer and so on and +so forth so you have if this was a a + + align:start position:0% +so forth so you have if this was a a + + + align:start position:0% +so forth so you have if this was a a +sequence of four of 400 long you would + + align:start position:0% +sequence of four of 400 long you would + + + align:start position:0% +sequence of four of 400 long you would +have 400 + + align:start position:0% +have 400 + + + align:start position:0% +have 400 +tenm okay and then you're obviously + + align:start position:0% +tenm okay and then you're obviously + + + align:start position:0% +tenm okay and then you're obviously +multiplying the total data volume by a + + align:start position:0% +multiplying the total data volume by a + + + align:start position:0% +multiplying the total data volume by a +factor of 10 because of this thing and + + align:start position:0% +factor of 10 because of this thing and + + + align:start position:0% +factor of 10 because of this thing and +so for those of us who know signal + + align:start position:0% +so for those of us who know signal + + + align:start position:0% +so for those of us who know signal +processing this is just standard + + align:start position:0% +processing this is just standard + + + align:start position:0% +processing this is just standard +filtering nothing new here very very + + align:start position:0% +filtering nothing new here very very + + + align:start position:0% +filtering nothing new here very very +standard type of filtering approach so + + align:start position:0% +standard type of filtering approach so + + + align:start position:0% +standard type of filtering approach so +then what we do is for each sequence + + align:start position:0% +then what we do is for each sequence + + + align:start position:0% +then what we do is for each sequence +ID okay this forms the row key of an + + align:start position:0% +ID okay this forms the row key of an + + + align:start position:0% +ID okay this forms the row key of an +associative array and each 10mer of that + + align:start position:0% +associative array and each 10mer of that + + + align:start position:0% +associative array and each 10mer of that +sequence of forms a column key of that + + align:start position:0% +sequence of forms a column key of that + + + align:start position:0% +sequence of forms a column key of that +tenr so you can see here each of these + + align:start position:0% +tenr so you can see here each of these + + + align:start position:0% +tenr so you can see here each of these +rows shows you all the unique teners + + align:start position:0% +rows shows you all the unique teners + + + align:start position:0% +rows shows you all the unique teners +that appeared in that + + align:start position:0% +that appeared in that + + + align:start position:0% +that appeared in that +sequence and then a column is you know a + + align:start position:0% +sequence and then a column is you know a + + + align:start position:0% +sequence and then a column is you know a +particular tenr so as we can see certain + + align:start position:0% +particular tenr so as we can see certain + + + align:start position:0% +particular tenr so as we can see certain +teners + + align:start position:0% +teners + + + align:start position:0% +teners +appear very commonly and some appear in + + align:start position:0% +appear very commonly and some appear in + + + align:start position:0% +appear very commonly and some appear in +a not so common way so that gives us an + + align:start position:0% +a not so common way so that gives us an + + + align:start position:0% +a not so common way so that gives us an +associative array which is a matri a + + align:start position:0% +associative array which is a matri a + + + align:start position:0% +associative array which is a matri a +sparse Matrix where we have sequence ID + + align:start position:0% +sparse Matrix where we have sequence ID + + + align:start position:0% +sparse Matrix where we have sequence ID +by tenr and then we do the same thing + + align:start position:0% +by tenr and then we do the same thing + + + align:start position:0% +by tenr and then we do the same thing +with a collection so we've collected in + + align:start position:0% +with a collection so we've collected in + + + align:start position:0% +with a collection so we've collected in +this case some unknown bacteria sample + + align:start position:0% +this case some unknown bacteria sample + + + align:start position:0% +this case some unknown bacteria sample +and we have a similar set of sequences + + align:start position:0% +and we have a similar set of sequences + + + align:start position:0% +and we have a similar set of sequences +here and we do the exact same thing we + + align:start position:0% +here and we do the exact same thing we + + + align:start position:0% +here and we do the exact same thing we +have a sequence ID and then the tenr and + + align:start position:0% +have a sequence ID and then the tenr and + + + align:start position:0% +have a sequence ID and then the tenr and +then what we want to do is + + align:start position:0% +then what we want to do is + + + align:start position:0% +then what we want to do is +cross-correlate find all the matches + + align:start position:0% +cross-correlate find all the matches + + + align:start position:0% +cross-correlate find all the matches +between them and so that's just done + + align:start position:0% +between them and so that's just done + + + align:start position:0% +between them and so that's just done +with matri Matrix multiply so A1 + + align:start position:0% +with matri Matrix multiply so A1 + + + align:start position:0% +with matri Matrix multiply so A1 +transpose A2 will then result in a new + + align:start position:0% +transpose A2 will then result in a new + + + align:start position:0% +transpose A2 will then result in a new +Matrix which is reference sequence ID by + + align:start position:0% +Matrix which is reference sequence ID by + + + align:start position:0% +Matrix which is reference sequence ID by +unknown sequence ID and then it will + + align:start position:0% +unknown sequence ID and then it will + + + align:start position:0% +unknown sequence ID and then it will +then the value in here will be how many + + align:start position:0% +then the value in here will be how many + + + align:start position:0% +then the value in here will be how many +matches they had and so generally you + + align:start position:0% +matches they had and so generally you + + + align:start position:0% +matches they had and so generally you +look if say 400 you know was the match + + align:start position:0% +look if say 400 you know was the match + + + align:start position:0% +look if say 400 you know was the match +then you would be looking for things you + + align:start position:0% +then you would be looking for things you + + + align:start position:0% +then you would be looking for things you +know well above 30 or 40 matches between + + align:start position:0% +know well above 30 or 40 matches between + + + align:start position:0% +know well above 30 or 40 matches between +them you know a true match would be + + align:start position:0% +them you know a true match would be + + + align:start position:0% +them you know a true match would be +maybe 50 60 70% of them uh uh match and + + align:start position:0% +maybe 50 60 70% of them uh uh match and + + + align:start position:0% +maybe 50 60 70% of them uh uh match and +so then you can just apply a threshold + + align:start position:0% +so then you can just apply a threshold + + + align:start position:0% +so then you can just apply a threshold +to this to DET to find the true true + + align:start position:0% +to this to DET to find the true true + + + align:start position:0% +to this to DET to find the true true +matches so very simple and you know + + align:start position:0% +matches so very simple and you know + + + align:start position:0% +matches so very simple and you know +there there are large software packages + + align:start position:0% +there there are large software packages + + + align:start position:0% +there there are large software packages +out there that do this they essentially + + align:start position:0% +out there that do this they essentially + + + align:start position:0% +out there that do this they essentially +do this algorithm with various twists + + align:start position:0% +do this algorithm with various twists + + + align:start position:0% +do this algorithm with various twists +and variations and stuff like that but + + align:start position:0% +and variations and stuff like that but + + + align:start position:0% +and variations and stuff like that but +here we can explain the whole thing + + align:start position:0% +here we can explain the whole thing + + + align:start position:0% +here we can explain the whole thing +knowing the mathematics of associative + + align:start position:0% +knowing the mathematics of associative + + + align:start position:0% +knowing the mathematics of associative +arrays on one on one + + align:start position:0% +arrays on one on one + + + align:start position:0% +arrays on one on one +slide + + align:start position:0% +slide + + + align:start position:0% +slide +so + + align:start position:0% +so + + + align:start position:0% +so +this calculation is what we call a + + align:start position:0% +this calculation is what we call a + + + align:start position:0% +this calculation is what we call a +direct match calculation we're literally + + align:start position:0% +direct match calculation we're literally + + + align:start position:0% +direct match calculation we're literally +comparing every single sequences 10 ms + + align:start position:0% +comparing every single sequences 10 ms + + + align:start position:0% +comparing every single sequences 10 ms +with all the other ones you know um and + + align:start position:0% +with all the other ones you know um and + + + align:start position:0% +with all the other ones you know um and +uh this is essentially what sequence + + align:start position:0% +uh this is essentially what sequence + + + align:start position:0% +uh this is essentially what sequence +comparison does and um it's takes a lot + + align:start position:0% +comparison does and um it's takes a lot + + + align:start position:0% +comparison does and um it's takes a lot +of computation to do this you know if + + align:start position:0% +of computation to do this you know if + + + align:start position:0% +of computation to do this you know if +you might have you know millions of + + align:start position:0% +you might have you know millions of + + + align:start position:0% +you might have you know millions of +sequence IDs and millions of sequence + + align:start position:0% +sequence IDs and millions of sequence + + + align:start position:0% +sequence IDs and millions of sequence +IDs this very quickly becomes you know + + align:start position:0% +IDs this very quickly becomes you know + + + align:start position:0% +IDs this very quickly becomes you know +uh a large amount of computational + + align:start position:0% +uh a large amount of computational + + + align:start position:0% +uh a large amount of computational +effort so we are of course interested in + + align:start position:0% +effort so we are of course interested in + + + align:start position:0% +effort so we are of course interested in +other techniques that could possibly + + align:start position:0% +other techniques that could possibly + + + align:start position:0% +other techniques that could possibly +accelerate this so one of the things + + align:start position:0% +accelerate this so one of the things + + + align:start position:0% +accelerate this so one of the things +we're able to do using the cumulo + + align:start position:0% +we're able to do using the cumulo + + + align:start position:0% +we're able to do using the cumulo +database is ingest this entire set of + + align:start position:0% +database is ingest this entire set of + + + align:start position:0% +database is ingest this entire set of +data as an associative array into the + + align:start position:0% +data as an associative array into the + + + align:start position:0% +data as an associative array into the +database and using accumulus tally + + align:start position:0% +database and using accumulus tally + + + align:start position:0% +database and using accumulus tally +features then tally have it essentially + + align:start position:0% +features then tally have it essentially + + + align:start position:0% +features then tally have it essentially +as we do the ingestion automatically + + align:start position:0% +as we do the ingestion automatically + + + align:start position:0% +as we do the ingestion automatically +tally the counts for each tenr so we can + + align:start position:0% +tally the counts for each tenr so we can + + + align:start position:0% +tally the counts for each tenr so we can +then essentially construct a histogram + + align:start position:0% +then essentially construct a histogram + + + align:start position:0% +then essentially construct a histogram +of all the tenur some tenur will appear + + align:start position:0% +of all the tenur some tenur will appear + + + align:start position:0% +of all the tenur some tenur will appear +in a very large number of sequences and + + align:start position:0% +in a very large number of sequences and + + + align:start position:0% +in a very large number of sequences and +Sun 10 teners will appear and not very + + align:start position:0% +Sun 10 teners will appear and not very + + + align:start position:0% +Sun 10 teners will appear and not very +many + + align:start position:0% +many + + + align:start position:0% +many +so this is that histogram or essentially + + align:start position:0% +so this is that histogram or essentially + + + align:start position:0% +so this is that histogram or essentially +a degree distribution we talked about + + align:start position:0% +a degree distribution we talked about + + + align:start position:0% +a degree distribution we talked about +degree distributions and other this + + align:start position:0% +degree distributions and other this + + + align:start position:0% +degree distributions and other this +tells us that there's one 10mer that + + align:start position:0% +tells us that there's one 10mer that + + + align:start position:0% +tells us that there's one 10mer that +appears in you know 80 or 90% of all the + + align:start position:0% +appears in you know 80 or 90% of all the + + + align:start position:0% +appears in you know 80 or 90% of all the +sequences and then there's a you know 20 + + align:start position:0% +sequences and then there's a you know 20 + + + align:start position:0% +sequences and then there's a you know 20 +or 30 10 ms that appear in just + + align:start position:0% +or 30 10 ms that appear in just + + + align:start position:0% +or 30 10 ms that appear in just +a few and then there's a distribution in + + align:start position:0% +a few and then there's a distribution in + + + align:start position:0% +a few and then there's a distribution in +this case almost a sort of almost a log + + align:start position:0% +this case almost a sort of almost a log + + + align:start position:0% +this case almost a sort of almost a log +normal curve that shows you um um you + + align:start position:0% +normal curve that shows you um um you + + + align:start position:0% +normal curve that shows you um um you +know that really uh you know most of the + + align:start position:0% +know that really uh you know most of the + + + align:start position:0% +know that really uh you know most of the +10 ms seem to have uh you know appear in + + align:start position:0% +10 ms seem to have uh you know appear in + + + align:start position:0% +10 ms seem to have uh you know appear in +a few hundred + + align:start position:0% +a few hundred + + + align:start position:0% +a few hundred +sequences and so now one thing I've done + + align:start position:0% +sequences and so now one thing I've done + + + align:start position:0% +sequences and so now one thing I've done +here is create certain + + align:start position:0% +here is create certain + + + align:start position:0% +here is create certain +thresholds to say all right + + align:start position:0% +thresholds to say all right + + + align:start position:0% +thresholds to say all right +if I only wanted if I looked at that + + align:start position:0% +if I only wanted if I looked at that + + + align:start position:0% +if I only wanted if I looked at that +large sparse Matrix of the data and I + + align:start position:0% +large sparse Matrix of the data and I + + + align:start position:0% +large sparse Matrix of the data and I +wanted to + + align:start position:0% +wanted to + + + align:start position:0% +wanted to +threshold uh what how many how much of + + align:start position:0% +threshold uh what how many how much of + + + align:start position:0% +threshold uh what how many how much of +the data would I eliminate so if I + + align:start position:0% +the data would I eliminate so if I + + + align:start position:0% +the data would I eliminate so if I +wanted to eliminate 50% of the data I + + align:start position:0% +wanted to eliminate 50% of the data I + + + align:start position:0% +wanted to eliminate 50% of the data I +could set a threshold let's only look at + + align:start position:0% +could set a threshold let's only look at + + + align:start position:0% +could set a threshold let's only look at +things that are less than a degree of + + align:start position:0% +things that are less than a degree of + + + align:start position:0% +things that are less than a degree of +10,000 and you might say well why would + + align:start position:0% +10,000 and you might say well why would + + + align:start position:0% +10,000 and you might say well why would +I want to eliminate these very very + + align:start position:0% +I want to eliminate these very very + + + align:start position:0% +I want to eliminate these very very +popular things well well because they + + align:start position:0% +popular things well well because they + + + align:start position:0% +popular things well well because they +appear everywhere a true match is + + align:start position:0% +appear everywhere a true match is + + + align:start position:0% +appear everywhere a true match is +they're not going to give me any + + align:start position:0% +they're not going to give me any + + + align:start position:0% +they're not going to give me any +information that really tells me about + + align:start position:0% +information that really tells me about + + + align:start position:0% +information that really tells me about +true matches those are going to be + + align:start position:0% +true matches those are going to be + + + align:start position:0% +true matches those are going to be +clutter everything has them that two + + align:start position:0% +clutter everything has them that two + + + align:start position:0% +clutter everything has them that two +sequences share that particular tenr + + align:start position:0% +sequences share that particular tenr + + + align:start position:0% +sequences share that particular tenr +doesn't really give me a lot of power in + + align:start position:0% +doesn't really give me a lot of power in + + + align:start position:0% +doesn't really give me a lot of power in +in in selecting which one it really + + align:start position:0% +in in selecting which one it really + + + align:start position:0% +in in selecting which one it really +belongs + + align:start position:0% +belongs + + + align:start position:0% +belongs +to so like so I can do that if I wanted + + align:start position:0% +to so like so I can do that if I wanted + + + align:start position:0% +to so like so I can do that if I wanted +to go down to only 5% of the data I + + align:start position:0% +to go down to only 5% of the data I + + + align:start position:0% +to go down to only 5% of the data I +could say you know I only want to look + + align:start position:0% +could say you know I only want to look + + + align:start position:0% +could say you know I only want to look +at 10 m + + align:start position:0% +at 10 m + + + align:start position:0% +at 10 m +that are 100 you + + align:start position:0% +that are 100 you + + + align:start position:0% +that are 100 you +know that have that appear in 100 of + + align:start position:0% +know that have that appear in 100 of + + + align:start position:0% +know that have that appear in 100 of +these sequences less and if I wanted to + + align:start position:0% +these sequences less and if I wanted to + + + align:start position:0% +these sequences less and if I wanted to +go even further you know I could go down + + align:start position:0% +go even further you know I could go down + + + align:start position:0% +go even further you know I could go down +to is this 20 30 40 50 and I would only + + align:start position:0% +to is this 20 30 40 50 and I would only + + + align:start position:0% +to is this 20 30 40 50 and I would only +have 1 half% of the data I would have + + align:start position:0% +have 1 half% of the data I would have + + + align:start position:0% +have 1 half% of the data I would have +eliminated from consideration 99.5% of + + align:start position:0% +eliminated from consideration 99.5% of + + + align:start position:0% +eliminated from consideration 99.5% of +the + + align:start position:0% +the + + + align:start position:0% +the +data + + align:start position:0% +data + + + align:start position:0% +data +so and then if I can do that then that's + + align:start position:0% +so and then if I can do that then that's + + + align:start position:0% +so and then if I can do that then that's +very powerful because I can quickly + + align:start position:0% +very powerful because I can quickly + + + align:start position:0% +very powerful because I can quickly +take my sample data set I know all the + + align:start position:0% +take my sample data set I know all the + + + align:start position:0% +take my sample data set I know all the +teners it has and I can quickly look it + + align:start position:0% +teners it has and I can quickly look it + + + align:start position:0% +teners it has and I can quickly look it +up against this histogram and say no I + + align:start position:0% +up against this histogram and say no I + + + align:start position:0% +up against this histogram and say no I +don't want to do any I only care about + + align:start position:0% +don't want to do any I only care about + + + align:start position:0% +don't want to do any I only care about +this very small section of data and I + + align:start position:0% +this very small section of data and I + + + align:start position:0% +this very small section of data and I +only need to do correlations from that + + align:start position:0% +only need to do correlations from that + + + align:start position:0% +only need to do correlations from that +so let's see how that works + + align:start position:0% +so let's see how that works + + + align:start position:0% +so let's see how that works +out and I should say this technique is + + align:start position:0% +out and I should say this technique is + + + align:start position:0% +out and I should say this technique is +very generic you could do it for text + + align:start position:0% +very generic you could do it for text + + + align:start position:0% +very generic you could do it for text +matching if you have documents you have + + align:start position:0% +matching if you have documents you have + + + align:start position:0% +matching if you have documents you have +the same issue very popular words are + + align:start position:0% +the same issue very popular words are + + + align:start position:0% +the same issue very popular words are +not going to tell you really anything + + align:start position:0% +not going to tell you really anything + + + align:start position:0% +not going to tell you really anything +meaningful about whether two documents + + align:start position:0% +meaningful about whether two documents + + + align:start position:0% +meaningful about whether two documents +are related to an it's going to be + + align:start position:0% +are related to an it's going to be + + + align:start position:0% +are related to an it's going to be +clutter um and other types of records of + + align:start position:0% +clutter um and other types of records of + + + align:start position:0% +clutter um and other types of records of +that thing you know so in the graph + + align:start position:0% +that thing you know so in the graph + + + align:start position:0% +that thing you know so in the graph +Theory perspective we call these super + + align:start position:0% +Theory perspective we call these super + + + align:start position:0% +Theory perspective we call these super +nodes these 10 ms are super nodes they + + align:start position:0% +nodes these 10 ms are super nodes they + + + align:start position:0% +nodes these 10 ms are super nodes they +have connections to many many things and + + align:start position:0% +have connections to many many things and + + + align:start position:0% +have connections to many many things and +therefore if you try and connect through + + align:start position:0% +therefore if you try and connect through + + + align:start position:0% +therefore if you try and connect through +them it's just going to not give you + + align:start position:0% +them it's just going to not give you + + + align:start position:0% +them it's just going to not give you +very useful information um you know it's + + align:start position:0% +very useful information um you know it's + + + align:start position:0% +very useful information um you know it's +like um people visiting + + align:start position:0% +like um people visiting + + + align:start position:0% +like um people visiting +Google looking for all the records where + + align:start position:0% +Google looking for all the records where + + + align:start position:0% +Google looking for all the records where +people connect visited Google is not + + align:start position:0% +people connect visited Google is not + + + align:start position:0% +people connect visited Google is not +really going to tell you much you know + + align:start position:0% +really going to tell you much you know + + + align:start position:0% +really going to tell you much you know +unless you have more information you + + align:start position:0% +unless you have more information you + + + align:start position:0% +unless you have more information you +know and so it's it's not a very big uh + + align:start position:0% +know and so it's it's not a very big uh + + + align:start position:0% +know and so it's it's not a very big uh +distinguishing + + align:start position:0% +distinguishing + + + align:start position:0% +distinguishing +Factor so here's an example of the + + align:start position:0% +Factor so here's an example of the + + + align:start position:0% +Factor so here's an example of the +results of doing of selecting all you + + align:start position:0% +results of doing of selecting all you + + + align:start position:0% +results of doing of selecting all you +know a thresh this low threshold + + align:start position:0% +know a thresh this low threshold + + + align:start position:0% +know a thresh this low threshold +eliminating 99.5% of the data and then + + align:start position:0% +eliminating 99.5% of the data and then + + + align:start position:0% +eliminating 99.5% of the data and then +comparing our matches that we got with + + align:start position:0% +comparing our matches that we got with + + + align:start position:0% +comparing our matches that we got with +what happens when we used 100% % of the + + align:start position:0% +what happens when we used 100% % of the + + + align:start position:0% +what happens when we used 100% % of the +data and so what we have here is the + + align:start position:0% +data and so what we have here is the + + + align:start position:0% +data and so what we have here is the +true 10mer match and then the measured + + align:start position:0% +true 10mer match and then the measured + + + align:start position:0% +true 10mer match and then the measured +subsampled match here and what you see + + align:start position:0% +subsampled match here and what you see + + + align:start position:0% +subsampled match here and what you see +here is that you know we get a very very + + align:start position:0% +here is that you know we get a very very + + + align:start position:0% +here is that you know we get a very very +high success rate in terms of you know + + align:start position:0% +high success rate in terms of you know + + + align:start position:0% +high success rate in terms of you know +uh uh we basically detect all strong + + align:start position:0% +uh uh we basically detect all strong + + + align:start position:0% +uh uh we basically detect all strong +matches using only half percent of the + + align:start position:0% +matches using only half percent of the + + + align:start position:0% +matches using only half percent of the +data and you know uh the number of false + + align:start position:0% +data and you know uh the number of false + + + align:start position:0% +data and you know uh the number of false +positives is extremely low in fact a + + align:start position:0% +positives is extremely low in fact a + + + align:start position:0% +positives is extremely low in fact a +better way to look at that is if we look + + align:start position:0% +better way to look at that is if we look + + + align:start position:0% +better way to look at that is if we look +at the cumul commu probability of + + align:start position:0% +at the cumul commu probability of + + + align:start position:0% +at the cumul commu probability of +detection this shows this that if the + + align:start position:0% +detection this shows this that if the + + + align:start position:0% +detection this shows this that if the +actual match if there was actually 100 + + align:start position:0% +actual match if there was actually 100 + + + align:start position:0% +actual match if there was actually 100 +matches between two sequences we detect + + align:start position:0% +matches between two sequences we detect + + + align:start position:0% +matches between two sequences we detect +all of those using only 12th of the + + align:start position:0% +all of those using only 12th of the + + + align:start position:0% +all of those using only 12th of the +data and likewise in our probability + + align:start position:0% +data and likewise in our probability + + + align:start position:0% +data and likewise in our probability +false alarm rate + + align:start position:0% +false alarm rate + + + align:start position:0% +false alarm rate +we see that if you see more than a match + + align:start position:0% +we see that if you see more than a match + + + align:start position:0% +we see that if you see more than a match +of 10 in the subsample data that is + + align:start position:0% +of 10 in the subsample data that is + + + align:start position:0% +of 10 in the subsample data that is +going to be a true match essentially + + align:start position:0% +going to be a true match essentially + + + align:start position:0% +going to be a true match essentially +100% of the time and so this technique + + align:start position:0% +100% of the time and so this technique + + + align:start position:0% +100% of the time and so this technique +allows us to dramatically speed up the + + align:start position:0% +allows us to dramatically speed up the + + + align:start position:0% +allows us to dramatically speed up the +rate at which we can do these + + align:start position:0% +rate at which we can do these + + + align:start position:0% +rate at which we can do these +comparisons now you do have the price to + + align:start position:0% +comparisons now you do have the price to + + + align:start position:0% +comparisons now you do have the price to +pay that you have to preload your + + align:start position:0% +pay that you have to preload your + + + align:start position:0% +pay that you have to preload your +reference data data into this special + + align:start position:0% +reference data data into this special + + + align:start position:0% +reference data data into this special +database but you since you tend to be + + align:start position:0% +database but you since you tend to be + + + align:start position:0% +database but you since you tend to be +more concerned conned about comparing + + align:start position:0% +more concerned conned about comparing + + + align:start position:0% +more concerned conned about comparing +with respect to it that is a a + + align:start position:0% +with respect to it that is a a + + + align:start position:0% +with respect to it that is a a +worthwhile + + align:start position:0% +worthwhile + + + align:start position:0% +worthwhile +investment so that's just an example of + + align:start position:0% +investment so that's just an example of + + + align:start position:0% +investment so that's just an example of +the how you can use these techniques use + + align:start position:0% +the how you can use these techniques use + + + align:start position:0% +the how you can use these techniques use +the mathematics of associative arrays + + align:start position:0% +the mathematics of associative arrays + + + align:start position:0% +the mathematics of associative arrays +and and these databases uh together in a + + align:start position:0% +and and these databases uh together in a + + + align:start position:0% +and and these databases uh together in a +in a in a coherent + + align:start position:0% +in a in a coherent + + + align:start position:0% +in a in a coherent +way so we can do more than just + + align:start position:0% +way so we can do more than just + + + align:start position:0% +way so we can do more than just +find so the The Matrix multiply I showed + + align:start position:0% +find so the The Matrix multiply I showed + + + align:start position:0% +find so the The Matrix multiply I showed +you before A1 time A2 transpose showed + + align:start position:0% +you before A1 time A2 transpose showed + + + align:start position:0% +you before A1 time A2 transpose showed +us the counts the number of matches but + + align:start position:0% +us the counts the number of matches but + + + align:start position:0% +us the counts the number of matches but +sometimes we don't want to know more + + align:start position:0% +sometimes we don't want to know more + + + align:start position:0% +sometimes we don't want to know more +than that we want to know not just the + + align:start position:0% +than that we want to know not just the + + + align:start position:0% +than that we want to know not just the +number of matches but please show me the + + align:start position:0% +number of matches but please show me the + + + align:start position:0% +number of matches but please show me the +exact set of 10 ms that cause the match + + align:start position:0% +exact set of 10 ms that cause the match + + + align:start position:0% +exact set of 10 ms that cause the match +okay and so this is where and I think we + + align:start position:0% +okay and so this is where and I think we + + + align:start position:0% +okay and so this is where and I think we +talked about this in a previous lecture + + align:start position:0% +talked about this in a previous lecture + + + align:start position:0% +talked about this in a previous lecture +we have these special Matrix multiplies + + align:start position:0% +we have these special Matrix multiplies + + + align:start position:0% +we have these special Matrix multiplies +that will actually + + align:start position:0% +that will actually + + + align:start position:0% +that will actually +take the intersecting key in The Matrix + + align:start position:0% +take the intersecting key in The Matrix + + + align:start position:0% +take the intersecting key in The Matrix +multiply and now assign that to the + + align:start position:0% +multiply and now assign that to the + + + align:start position:0% +multiply and now assign that to the +value field or concatenate and so that's + + align:start position:0% +value field or concatenate and so that's + + + align:start position:0% +value field or concatenate and so that's +why we have this special Matrix multiply + + align:start position:0% +why we have this special Matrix multiply + + + align:start position:0% +why we have this special Matrix multiply +called cat key M and so for instance + + align:start position:0% +called cat key M and so for instance + + + align:start position:0% +called cat key M and so for instance +here if we look at the result of that + + align:start position:0% +here if we look at the result of that + + + align:start position:0% +here if we look at the result of that +which is AK and we say show me all the + + align:start position:0% +which is AK and we say show me all the + + + align:start position:0% +which is AK and we say show me all the +value matches that are you know greater + + align:start position:0% +value matches that are you know greater + + + align:start position:0% +value matches that are you know greater +than six in their rows and their columns + + align:start position:0% +than six in their rows and their columns + + + align:start position:0% +than six in their rows and their columns +together now we can see that this + + align:start position:0% +together now we can see that this + + + align:start position:0% +together now we can see that this +sequence ID matched with this sequence + + align:start position:0% +sequence ID matched with this sequence + + + align:start position:0% +sequence ID matched with this sequence +ID and these were the actual + + align:start position:0% +ID and these were the actual + + + align:start position:0% +ID and these were the actual +10mer that generate that they had in + + align:start position:0% +10mer that generate that they had in + + + align:start position:0% +10mer that generate that they had in +common now clearly six is not true match + + align:start position:0% +common now clearly six is not true match + + + align:start position:0% +common now clearly six is not true match +in this little sample data set we don't + + align:start position:0% +in this little sample data set we don't + + + align:start position:0% +in this little sample data set we don't +have any true matches but this just this + + align:start position:0% +have any true matches but this just this + + + align:start position:0% +have any true matches but this just this +just shows you what what that is like + + align:start position:0% +just shows you what what that is like + + + align:start position:0% +just shows you what what that is like +and so this is what we call a pedigree + + align:start position:0% +and so this is what we call a pedigree + + + align:start position:0% +and so this is what we call a pedigree +preserving correlation that is it shows + + align:start position:0% +preserving correlation that is it shows + + + align:start position:0% +preserving correlation that is it shows +you the the you know it doesn't just + + align:start position:0% +you the the you know it doesn't just + + + align:start position:0% +you the the you know it doesn't just +give you the count it it shows you where + + align:start position:0% +give you the count it it shows you where + + + align:start position:0% +give you the count it it shows you where +that evidence came from and you can + + align:start position:0% +that evidence came from and you can + + + align:start position:0% +that evidence came from and you can +track it back and this is something we + + align:start position:0% +track it back and this is something we + + + align:start position:0% +track it back and this is something we +do want to do all the time if you + + align:start position:0% +do want to do all the time if you + + + align:start position:0% +do want to do all the time if you +imagined two documents that you wanted + + align:start position:0% +imagined two documents that you wanted + + + align:start position:0% +imagined two documents that you wanted +to cross correlate you might say all + + align:start position:0% +to cross correlate you might say all + + + align:start position:0% +to cross correlate you might say all +right I have these two documents and i' + + align:start position:0% +right I have these two documents and i' + + + align:start position:0% +right I have these two documents and i' +i' I've cross-correlated their word + + align:start position:0% +i' I've cross-correlated their word + + + align:start position:0% +i' I've cross-correlated their word +matches well now I want to know the + + align:start position:0% +matches well now I want to know the + + + align:start position:0% +matches well now I want to know the +actual words that matched you know not + + align:start position:0% +actual words that matched you know not + + + align:start position:0% +actual words that matched you know not +just the counts and you would use the + + align:start position:0% +just the counts and you would use the + + + align:start position:0% +just the counts and you would use the +exact same uh multiply to do that you + + align:start position:0% +exact same uh multiply to do that you + + + align:start position:0% +exact same uh multiply to do that you +know likewise you could do the word word + + align:start position:0% +know likewise you could do the word word + + + align:start position:0% +know likewise you could do the word word +correlation of a document so that would + + align:start position:0% +correlation of a document so that would + + + align:start position:0% +correlation of a document so that would +be a transpose time a instead of a a + + align:start position:0% +be a transpose time a instead of a a + + + align:start position:0% +be a transpose time a instead of a a +transpose and then it would show you two + + align:start position:0% +transpose and then it would show you two + + + align:start position:0% +transpose and then it would show you two +words it would show the list of + + align:start position:0% +words it would show the list of + + + align:start position:0% +words it would show the list of +documents that they actually had in + + align:start position:0% +documents that they actually had in + + + align:start position:0% +documents that they actually had in +common so again this is a powerful uh a + + align:start position:0% +common so again this is a powerful uh a + + + align:start position:0% +common so again this is a powerful uh a +powerful tool again I I should remind + + align:start position:0% +powerful tool again I I should remind + + + align:start position:0% +powerful tool again I I should remind +people when using this you do have to be + + align:start position:0% +people when using this you do have to be + + + align:start position:0% +people when using this you do have to be +careful uh when you do say cat keall A1 + + align:start position:0% +careful uh when you do say cat keall A1 + + + align:start position:0% +careful uh when you do say cat keall A1 +time A1 transpose if you do a square + + align:start position:0% +time A1 transpose if you do a square + + + align:start position:0% +time A1 transpose if you do a square +because you will then end up with this + + align:start position:0% +because you will then end up with this + + + align:start position:0% +because you will then end up with this +very dense diagonal and these lists will + + align:start position:0% +very dense diagonal and these lists will + + + align:start position:0% +very dense diagonal and these lists will +get extremely long and you can often run + + align:start position:0% +get extremely long and you can often run + + + align:start position:0% +get extremely long and you can often run +out of memory when that happens so you + + align:start position:0% +out of memory when that happens so you + + + align:start position:0% +out of memory when that happens so you +do have to be careful when you do uh + + align:start position:0% +do have to be careful when you do uh + + + align:start position:0% +do have to be careful when you do uh +correlations these cat Keo correlations + + align:start position:0% +correlations these cat Keo correlations + + + align:start position:0% +correlations these cat Keo correlations +on things that are going to have very + + align:start position:0% +on things that are going to have very + + + align:start position:0% +on things that are going to have very +large uh overlapping matches the regular + + align:start position:0% +large uh overlapping matches the regular + + + align:start position:0% +large uh overlapping matches the regular +Matrix multiply you don't have to worry + + align:start position:0% +Matrix multiply you don't have to worry + + + align:start position:0% +Matrix multiply you don't have to worry +about that creating dense you know that + + align:start position:0% +about that creating dense you know that + + + align:start position:0% +about that creating dense you know that +that's that's that's not a problem but + + align:start position:0% +that's that's that's not a problem but + + + align:start position:0% +that's that's that's not a problem but +that's just a little caveat to be aware + + align:start position:0% +that's just a little caveat to be aware + + + align:start position:0% +that's just a little caveat to be aware +of and there's really nothing we can do + + align:start position:0% +of and there's really nothing we can do + + + align:start position:0% +of and there's really nothing we can do +about that if you do square them you + + align:start position:0% +about that if you do square them you + + + align:start position:0% +about that if you do square them you +know and we thought about creating a new + + align:start position:0% +know and we thought about creating a new + + + align:start position:0% +know and we thought about creating a new +function which is basically squaring + + align:start position:0% +function which is basically squaring + + + align:start position:0% +function which is basically squaring +with and basically not doing the DI + + align:start position:0% +with and basically not doing the DI + + + align:start position:0% +with and basically not doing the DI +diagonal and and we may we may end up + + align:start position:0% +diagonal and and we may we may end up + + + align:start position:0% +diagonal and and we may we may end up +you know making that if we can figure + + align:start position:0% +you know making that if we can figure + + + align:start position:0% +you know making that if we can figure +that one + + align:start position:0% +that one + + + align:start position:0% +that one +out so once you have those actual + + align:start position:0% +out so once you have those actual + + + align:start position:0% +out so once you have those actual +specific matches here so for example we + + align:start position:0% +specific matches here so for example we + + + align:start position:0% +specific matches here so for example we +have our two reference samples and we + + align:start position:0% +have our two reference samples and we + + + align:start position:0% +have our two reference samples and we +looked at the ones that were larger so + + align:start position:0% +looked at the ones that were larger so + + + align:start position:0% +looked at the ones that were larger so +here's our two sequences this this uh we + + align:start position:0% +here's our two sequences this this uh we + + + align:start position:0% +here's our two sequences this this uh we +look back at the original data which uh + + align:start position:0% +look back at the original data which uh + + + align:start position:0% +look back at the original data which uh +which actually stored the locations + + align:start position:0% +which actually stored the locations + + + align:start position:0% +which actually stored the locations +that so now we're saying oh these two + + align:start position:0% +that so now we're saying oh these two + + + align:start position:0% +that so now we're saying oh these two +have a have six matches between them let + + align:start position:0% +have a have six matches between them let + + + align:start position:0% +have a have six matches between them let +me look them up through this oneline + + align:start position:0% +me look them up through this oneline + + + align:start position:0% +me look them up through this oneline +statement here now I can see the actual + + align:start position:0% +statement here now I can see the actual + + + align:start position:0% +statement here now I can see the actual +10mer that match and their actual + + align:start position:0% +10mer that match and their actual + + + align:start position:0% +10mer that match and their actual +locations in the real data and from that + + align:start position:0% +locations in the real data and from that + + + align:start position:0% +locations in the real data and from that +I can then deduce that oh actually this + + align:start position:0% +I can then deduce that oh actually this + + + align:start position:0% +I can then deduce that oh actually this +is not six separate 10mer matches but + + align:start position:0% +is not six separate 10mer matches but + + + align:start position:0% +is not six separate 10mer matches but +it's really two s of uh uh is this 1 2 3 + + align:start position:0% +it's really two s of uh uh is this 1 2 3 + + + align:start position:0% +it's really two s of uh uh is this 1 2 3 +4 5 6 7 8 9 10 one 10 mer match and then + + align:start position:0% +4 5 6 7 8 9 10 one 10 mer match and then + + + align:start position:0% +4 5 6 7 8 9 10 one 10 mer match and then +I guess a I think this is like a 17 + + align:start position:0% +I guess a I think this is like a 17 + + + align:start position:0% +I guess a I think this is like a 17 +match right and likewise over here you + + align:start position:0% +match right and likewise over here you + + + align:start position:0% +match right and likewise over here you +get the a similar type of thing so + + align:start position:0% +get the a similar type of thing so + + + align:start position:0% +get the a similar type of thing so +that's basically stitching it back + + align:start position:0% +that's basically stitching it back + + + align:start position:0% +that's basically stitching it back +together because that's really what + + align:start position:0% +together because that's really what + + + align:start position:0% +together because that's really what +you're trying to do is find these longer + + align:start position:0% +you're trying to do is find these longer + + + align:start position:0% +you're trying to do is find these longer +sequences where it's identical and then + + align:start position:0% +sequences where it's identical and then + + + align:start position:0% +sequences where it's identical and then +people can then use those to determine + + align:start position:0% +people can then use those to determine + + + align:start position:0% +people can then use those to determine +you know functionality and other types + + align:start position:0% +you know functionality and other types + + + align:start position:0% +you know functionality and other types +of things that have to do do with that + + align:start position:0% +of things that have to do do with that + + + align:start position:0% +of things that have to do do with that +so this is just part of the process of + + align:start position:0% +so this is just part of the process of + + + align:start position:0% +so this is just part of the process of +of doing that and it just shows by + + align:start position:0% +of doing that and it just shows by + + + align:start position:0% +of doing that and it just shows by +having this pedigree preserving Matrix + + align:start position:0% +having this pedigree preserving Matrix + + + align:start position:0% +having this pedigree preserving Matrix +multip mly and the ability to store + + align:start position:0% +multip mly and the ability to store + + + align:start position:0% +multip mly and the ability to store +string values in the value that we can + + align:start position:0% +string values in the value that we can + + + align:start position:0% +string values in the value that we can +actually preserve that information and + + align:start position:0% +actually preserve that information and + + + align:start position:0% +actually preserve that information and +um and do + + align:start position:0% +um and do + + + align:start position:0% +um and do +that so that just shows you I think a + + align:start position:0% +that so that just shows you I think a + + + align:start position:0% +that so that just shows you I think a +really great example it's kind of one of + + align:start position:0% +really great example it's kind of one of + + + align:start position:0% +really great example it's kind of one of +the most recent things we did this + + align:start position:0% +the most recent things we did this + + + align:start position:0% +the most recent things we did this +summer in terms of the power of d4m + + align:start position:0% +summer in terms of the power of d4m + + + align:start position:0% +summer in terms of the power of d4m +coupled with databases to really do + + align:start position:0% +coupled with databases to really do + + + align:start position:0% +coupled with databases to really do +algorithms that are completely you + + align:start position:0% +algorithms that are completely you + + + align:start position:0% +algorithms that are completely you +know kind of new and and interesting and + + align:start position:0% +know kind of new and and interesting and + + + align:start position:0% +know kind of new and and interesting and +as algorithm developers I think that's + + align:start position:0% +as algorithm developers I think that's + + + align:start position:0% +as algorithm developers I think that's +something that we all very excited about + + align:start position:0% +something that we all very excited about + + + align:start position:0% +something that we all very excited about +so I'm now I'm going to talk about how + + align:start position:0% +so I'm now I'm going to talk about how + + + align:start position:0% +so I'm now I'm going to talk about how +this fits into an overall pipeline so + + align:start position:0% +this fits into an overall pipeline so + + + align:start position:0% +this fits into an overall pipeline so +once again just for reminders you know + + align:start position:0% +once again just for reminders you know + + + align:start position:0% +once again just for reminders you know +uh d4m you know we've talked mostly + + align:start position:0% +uh d4m you know we've talked mostly + + + align:start position:0% +uh d4m you know we've talked mostly +about working over here in this space in + + align:start position:0% +about working over here in this space in + + + align:start position:0% +about working over here in this space in +the mat lab space um for doing your + + align:start position:0% +the mat lab space um for doing your + + + align:start position:0% +the mat lab space um for doing your +analytics with associative arrays but + + align:start position:0% +analytics with associative arrays but + + + align:start position:0% +analytics with associative arrays but +they also have ways uh we have very nice + + align:start position:0% +they also have ways uh we have very nice + + + align:start position:0% +they also have ways uh we have very nice +bindings to in particular the cumulo + + align:start position:0% +bindings to in particular the cumulo + + + align:start position:0% +bindings to in particular the cumulo +database but we can bind to just about + + align:start position:0% +database but we can bind to just about + + + align:start position:0% +database but we can bind to just about +any database um and here's an example if + + align:start position:0% +any database um and here's an example if + + + align:start position:0% +any database um and here's an example if +I have a table that shows you know all + + align:start position:0% +I have a table that shows you know all + + + align:start position:0% +I have a table that shows you know all +this data and I just wanted to get + + align:start position:0% +this data and I just wanted to get + + + align:start position:0% +this data and I just wanted to get +please give me the column of this 10mer + + align:start position:0% +please give me the column of this 10mer + + + align:start position:0% +please give me the column of this 10mer +sequence I would just type that query + + align:start position:0% +sequence I would just type that query + + + align:start position:0% +sequence I would just type that query +and it will return that column for me + + align:start position:0% +and it will return that column for me + + + align:start position:0% +and it will return that column for me +very nicely so it's a very powerful + + align:start position:0% +very nicely so it's a very powerful + + + align:start position:0% +very nicely so it's a very powerful +binding to to databases it's funny + + align:start position:0% +binding to to databases it's funny + + + align:start position:0% +binding to to databases it's funny +because a lot of people when I talk to + + align:start position:0% +because a lot of people when I talk to + + + align:start position:0% +because a lot of people when I talk to +them they + + align:start position:0% +them they + + + align:start position:0% +them they +like they think dform is either just + + align:start position:0% +like they think dform is either just + + + align:start position:0% +like they think dform is either just +about + + align:start position:0% +about + + + align:start position:0% +about +databases or just about this associative + + align:start position:0% +databases or just about this associative + + + align:start position:0% +databases or just about this associative +R mathematics and because they usually + + align:start position:0% +R mathematics and because they usually + + + align:start position:0% +R mathematics and because they usually +kind of people take sort of they usually + + align:start position:0% +kind of people take sort of they usually + + + align:start position:0% +kind of people take sort of they usually +see it sort of more used in one one + + align:start position:0% +see it sort of more used in one one + + + align:start position:0% +see it sort of more used in one one +context or another and it's really about + + align:start position:0% +context or another and it's really about + + + align:start position:0% +context or another and it's really about +both it's really about connecting the + + align:start position:0% +both it's really about connecting the + + + align:start position:0% +both it's really about connecting the +two worlds + + align:start position:0% +two worlds + + + align:start position:0% +two worlds +together that particular application + + align:start position:0% +together that particular application + + + align:start position:0% +together that particular application +that we showed you this uh genetic + + align:start position:0% +that we showed you this uh genetic + + + align:start position:0% +that we showed you this uh genetic +sequence uh you know comparison uh + + align:start position:0% +sequence uh you know comparison uh + + + align:start position:0% +sequence uh you know comparison uh +application is like you is a part of a + + align:start position:0% +application is like you is a part of a + + + align:start position:0% +application is like you is a part of a +pipeline like you would see in any real + + align:start position:0% +pipeline like you would see in any real + + + align:start position:0% +pipeline like you would see in any real +system and so I'm going to show you that + + align:start position:0% +system and so I'm going to show you that + + + align:start position:0% +system and so I'm going to show you that +that pipeline here and so um you know we + + align:start position:0% +that pipeline here and so um you know we + + + align:start position:0% +that pipeline here and so um you know we +have here uh the the raw data so fasta + + align:start position:0% +have here uh the the raw data so fasta + + + align:start position:0% +have here uh the the raw data so fasta +is just the name of the file format that + + align:start position:0% +is just the name of the file format that + + + align:start position:0% +is just the name of the file format that +all this DNA sequence comes in which + + align:start position:0% +all this DNA sequence comes in which + + + align:start position:0% +all this DNA sequence comes in which +basically looks pretty much like a CSV + + align:start position:0% +basically looks pretty much like a CSV + + + align:start position:0% +basically looks pretty much like a CSV +file of what I just saw you I guess that + + align:start position:0% +file of what I just saw you I guess that + + + align:start position:0% +file of what I just saw you I guess that +deserves a a name as a file format but + + align:start position:0% +deserves a a name as a file format but + + + align:start position:0% +deserves a a name as a file format but +you know uh so it's basically it's + + align:start position:0% +you know uh so it's basically it's + + + align:start position:0% +you know uh so it's basically it's +basically that and then one thing we do + + align:start position:0% +basically that and then one thing we do + + + align:start position:0% +basically that and then one thing we do +is uh is uh we uh parse that data from + + align:start position:0% +is uh is uh we uh parse that data from + + + align:start position:0% +is uh is uh we uh parse that data from +the fasted data into triples + + align:start position:0% +the fasted data into triples + + + align:start position:0% +the fasted data into triples +format which um allows us to then um + + align:start position:0% +format which um allows us to then um + + + align:start position:0% +format which um allows us to then um +really work it with this associative + + align:start position:0% +really work it with this associative + + + align:start position:0% +really work it with this associative +array so it basically creates the 10ms + + align:start position:0% +array so it basically creates the 10ms + + + align:start position:0% +array so it basically creates the 10ms +and puts them into a series of triple + + align:start position:0% +and puts them into a series of triple + + + align:start position:0% +and puts them into a series of triple +files a a row triple file which holds a + + align:start position:0% +files a a row triple file which holds a + + + align:start position:0% +files a a row triple file which holds a +sequence ID uh the actual tenr itself + + align:start position:0% +sequence ID uh the actual tenr itself + + + align:start position:0% +sequence ID uh the actual tenr itself +list of those and then uh the position + + align:start position:0% +list of those and then uh the position + + + align:start position:0% +list of those and then uh the position +of where that tenr appeared in the + + align:start position:0% +of where that tenr appeared in the + + + align:start position:0% +of where that tenr appeared in the +sequence um and then typically what we + + align:start position:0% +sequence um and then typically what we + + + align:start position:0% +sequence um and then typically what we +do then is we + + align:start position:0% +do then is we + + + align:start position:0% +do then is we +read we write a program and this can be + + align:start position:0% +read we write a program and this can be + + + align:start position:0% +read we write a program and this can be +a parallel program if we want it that + + align:start position:0% +a parallel program if we want it that + + + align:start position:0% +a parallel program if we want it that +will then usually in mat lab using D4 + + align:start position:0% +will then usually in mat lab using D4 + + + align:start position:0% +will then usually in mat lab using D4 +that will read these sequences in and + + align:start position:0% +that will read these sequences in and + + + align:start position:0% +that will read these sequences in and +we'll often just directly insert them + + align:start position:0% +we'll often just directly insert them + + + align:start position:0% +we'll often just directly insert them +without any additional formatting just + + align:start position:0% +without any additional formatting just + + + align:start position:0% +without any additional formatting just +we have a way of just inserting triples + + align:start position:0% +we have a way of just inserting triples + + + align:start position:0% +we have a way of just inserting triples +directly into the cumulo database and + + align:start position:0% +directly into the cumulo database and + + + align:start position:0% +directly into the cumulo database and +which is the fastest way that we can do + + align:start position:0% +which is the fastest way that we can do + + + align:start position:0% +which is the fastest way that we can do +inserts um and then it will + + align:start position:0% +inserts um and then it will + + + align:start position:0% +inserts um and then it will +also uh convert these two associative + + align:start position:0% +also uh convert these two associative + + + align:start position:0% +also uh convert these two associative +arrays in mat lab and we'll save them + + align:start position:0% +arrays in mat lab and we'll save them + + + align:start position:0% +arrays in mat lab and we'll save them +out as matte files uh because this will + + align:start position:0% +out as matte files uh because this will + + + align:start position:0% +out as matte files uh because this will +take a little time to convert all of + + align:start position:0% +take a little time to convert all of + + + align:start position:0% +take a little time to convert all of +these things into files you like well + + align:start position:0% +these things into files you like well + + + align:start position:0% +these things into files you like well +why would we do that well there's two + + align:start position:0% +why would we do that well there's two + + + align:start position:0% +why would we do that well there's two +very good reasons for doing that one + + align:start position:0% +very good reasons for doing that one + + + align:start position:0% +very good reasons for doing that one +yukimo database or any database is very + + align:start position:0% +yukimo database or any database is very + + + align:start position:0% +yukimo database or any database is very +good if we want to look up a small part + + align:start position:0% +good if we want to look up a small part + + + align:start position:0% +good if we want to look up a small part +of a large data set okay so we have + + align:start position:0% +of a large data set okay so we have + + + align:start position:0% +of a large data set okay so we have +billions of records and we want millions + + align:start position:0% +billions of records and we want millions + + + align:start position:0% +billions of records and we want millions +of those records that's a great use of a + + align:start position:0% +of those records that's a great use of a + + + align:start position:0% +of those records that's a great use of a +database however there's certain times + + align:start position:0% +database however there's certain times + + + align:start position:0% +database however there's certain times +we're like no we want to Traverse the + + align:start position:0% +we're like no we want to Traverse the + + + align:start position:0% +we're like no we want to Traverse the +entire data set well databases are + + align:start position:0% +entire data set well databases are + + + align:start position:0% +entire data set well databases are +actually bad at doing that if you say I + + align:start position:0% +actually bad at doing that if you say I + + + align:start position:0% +actually bad at doing that if you say I +want to scan over the entire database + + align:start position:0% +want to scan over the entire database + + + align:start position:0% +want to scan over the entire database +it's like doing a billion queries you + + align:start position:0% +it's like doing a billion queries you + + + align:start position:0% +it's like doing a billion queries you +know and so there's overheads associated + + align:start position:0% +know and so there's overheads associated + + + align:start position:0% +know and so there's overheads associated +with that in that instance it's far more + + align:start position:0% +with that in that instance it's far more + + + align:start position:0% +with that in that instance it's far more +efficient to just save the data into + + align:start position:0% +efficient to just save the data into + + + align:start position:0% +efficient to just save the data into +these associate radio files which will + + align:start position:0% +these associate radio files which will + + + align:start position:0% +these associate radio files which will +read in very quickly and then you can + + align:start position:0% +read in very quickly and then you can + + + align:start position:0% +read in very quickly and then you can +just if you're like I want to do an + + align:start position:0% +just if you're like I want to do an + + + align:start position:0% +just if you're like I want to do an +analysis you know of the data uh in that + + align:start position:0% +analysis you know of the data uh in that + + + align:start position:0% +analysis you know of the data uh in that +way where I'm going to want I really + + align:start position:0% +way where I'm going to want I really + + + align:start position:0% +way where I'm going to want I really +want to you know work with 10% or 20% of + + align:start position:0% +want to you know work with 10% or 20% of + + + align:start position:0% +want to you know work with 10% or 20% of +the data then having these these the + + align:start position:0% +the data then having these these the + + + align:start position:0% +the data then having these these the +this data in this you know already + + align:start position:0% +this data in this you know already + + + align:start position:0% +this data in this you know already +parsed into this binary format is a very + + align:start position:0% +parsed into this binary format is a very + + + align:start position:0% +parsed into this binary format is a very +efficient way to run an application or + + align:start position:0% +efficient way to run an application or + + + align:start position:0% +efficient way to run an application or +an analytic that will run over all those + + align:start position:0% +an analytic that will run over all those + + + align:start position:0% +an analytic that will run over all those +files it also U makes parallelism very + + align:start position:0% +files it also U makes parallelism very + + + align:start position:0% +files it also U makes parallelism very +easily you just get let you know + + align:start position:0% +easily you just get let you know + + + align:start position:0% +easily you just get let you know +different processors process different + + align:start position:0% +different processors process different + + + align:start position:0% +different processors process different +files you know that's very easy to do we + + align:start position:0% +files you know that's very easy to do we + + + align:start position:0% +files you know that's very easy to do we +have lots of support for that type of of + + align:start position:0% +have lots of support for that type of of + + + align:start position:0% +have lots of support for that type of of +model and so that's a good reason to do + + align:start position:0% +model and so that's a good reason to do + + + align:start position:0% +model and so that's a good reason to do +that um and you know at worst you're + + align:start position:0% +that um and you know at worst you're + + + align:start position:0% +that um and you know at worst you're +doubling the size of the data in your + + align:start position:0% +doubling the size of the data in your + + + align:start position:0% +doubling the size of the data in your +database don't worry about it we double + + align:start position:0% +database don't worry about it we double + + + align:start position:0% +database don't worry about it we double +data in databases all the time databases + + align:start position:0% +data in databases all the time databases + + + align:start position:0% +data in databases all the time databases +are notoriously if you put a certain + + align:start position:0% +are notoriously if you put a certain + + + align:start position:0% +are notoriously if you put a certain +amount of data in they they they you + + align:start position:0% +amount of data in they they they you + + + align:start position:0% +amount of data in they they they you +know they make it much larger acumulo + + align:start position:0% +know they make it much larger acumulo + + + align:start position:0% +know they make it much larger acumulo +actually does a very good job of that it + + align:start position:0% +actually does a very good job of that it + + + align:start position:0% +actually does a very good job of that it +won't really be that much larger but + + align:start position:0% +won't really be that much larger but + + + align:start position:0% +won't really be that much larger but +there's no reason uh to not as you're + + align:start position:0% +there's no reason uh to not as you're + + + align:start position:0% +there's no reason uh to not as you're +doing the injest to save those files and + + align:start position:0% +doing the injest to save those files and + + + align:start position:0% +doing the injest to save those files and +then you can do various + + align:start position:0% +then you can do various + + + align:start position:0% +then you can do various +comparisons um uh so for example uh you + + align:start position:0% +comparisons um uh so for example uh you + + + align:start position:0% +comparisons um uh so for example uh you +know uh we then can uh if this if we + + align:start position:0% +know uh we then can uh if this if we + + + align:start position:0% +know uh we then can uh if this if we +save the um the sample data as a matlb + + align:start position:0% +save the um the sample data as a matlb + + + align:start position:0% +save the um the sample data as a matlb +file we could read that in and then um + + align:start position:0% +file we could read that in and then um + + + align:start position:0% +file we could read that in and then um +and then uh uh then uh do our comparison + + align:start position:0% +and then uh uh then uh do our comparison + + + align:start position:0% +and then uh uh then uh do our comparison +with the reference data that's sitting + + align:start position:0% +with the reference data that's sitting + + + align:start position:0% +with the reference data that's sitting +inside the database to get our top + + align:start position:0% +inside the database to get our top + + + align:start position:0% +inside the database to get our top +matches and that's exactly how this + + align:start position:0% +matches and that's exactly how this + + + align:start position:0% +matches and that's exactly how this +application actually worked so this pipe + + align:start position:0% +application actually worked so this pipe + + + align:start position:0% +application actually worked so this pipe +P line from raw data to an intermediate + + align:start position:0% +P line from raw data to an intermediate + + + align:start position:0% +P line from raw data to an intermediate +format to you know sort of efficient + + align:start position:0% +format to you know sort of efficient + + + align:start position:0% +format to you know sort of efficient +binary format and insertion uh then to + + align:start position:0% +binary format and insertion uh then to + + + align:start position:0% +binary format and insertion uh then to +then uh doing the analytics and + + align:start position:0% +then uh doing the analytics and + + + align:start position:0% +then uh doing the analytics and +comparisons and eventually you'll + + align:start position:0% +comparisons and eventually you'll + + + align:start position:0% +comparisons and eventually you'll +usually often have another layer which + + align:start position:0% +usually often have another layer which + + + align:start position:0% +usually often have another layer which +is you might create a web interface to + + align:start position:0% +is you might create a web interface to + + + align:start position:0% +is you might create a web interface to +something we're like okay this is now a + + align:start position:0% +something we're like okay this is now a + + + align:start position:0% +something we're like okay this is now a +full system you know person can type in + + align:start position:0% +full system you know person can type in + + + align:start position:0% +full system you know person can type in +you know put in their own data and then + + align:start position:0% +you know put in their own data and then + + + align:start position:0% +you know put in their own data and then +it will then call a function so again + + align:start position:0% +it will then call a function so again + + + align:start position:0% +it will then call a function so again +this is very standard how this stuff + + align:start position:0% +this is very standard how this stuff + + + align:start position:0% +this is very standard how this stuff +ends up uh fitting into an overall + + align:start position:0% +ends up uh fitting into an overall + + + align:start position:0% +ends up uh fitting into an overall +pipeline um and it's certainly a + + align:start position:0% +pipeline um and it's certainly a + + + align:start position:0% +pipeline um and it's certainly a +situation where if you're going to + + align:start position:0% +situation where if you're going to + + + align:start position:0% +situation where if you're going to +deploy a system you might decide you + + align:start position:0% +deploy a system you might decide you + + + align:start position:0% +deploy a system you might decide you +know what I don't want mat lab to be a + + align:start position:0% +know what I don't want mat lab to be a + + + align:start position:0% +know what I don't want mat lab to be a +part of my deployed system I want to do + + align:start position:0% +part of my deployed system I want to do + + + align:start position:0% +part of my deployed system I want to do +that say in Joba or something else + + align:start position:0% +that say in Joba or something else + + + align:start position:0% +that say in Joba or something else +that's sort of more Universal which we + + align:start position:0% +that's sort of more Universal which we + + + align:start position:0% +that's sort of more Universal which we +certainly see people do it still makes + + align:start position:0% +certainly see people do it still makes + + + align:start position:0% +certainly see people do it still makes +sense to do it in this approach because + + align:start position:0% +sense to do it in this approach because + + + align:start position:0% +sense to do it in this approach because +the algorithm development and testing is + + align:start position:0% +the algorithm development and testing is + + + align:start position:0% +the algorithm development and testing is +just much much easier to do in an + + align:start position:0% +just much much easier to do in an + + + align:start position:0% +just much much easier to do in an +environment like d4m and then once you + + align:start position:0% +environment like d4m and then once you + + + align:start position:0% +environment like d4m and then once you +have the algorithm correct it's now much + + align:start position:0% +have the algorithm correct it's now much + + + align:start position:0% +have the algorithm correct it's now much +easier to give that to someone else who + + align:start position:0% +easier to give that to someone else who + + + align:start position:0% +easier to give that to someone else who +is going to do the implementation in + + align:start position:0% +is going to do the implementation in + + + align:start position:0% +is going to do the implementation in +another environment and deal with all + + align:start position:0% +another environment and deal with all + + + align:start position:0% +another environment and deal with all +the issues that are associated with + + align:start position:0% +the issues that are associated with + + + align:start position:0% +the issues that are associated with +maybe doing a deployment type of thing + + align:start position:0% +maybe doing a deployment type of thing + + + align:start position:0% +maybe doing a deployment type of thing +so one certainly could use uh the mat + + align:start position:0% +so one certainly could use uh the mat + + + align:start position:0% +so one certainly could use uh the mat +lab or or G new octave uh code in a + + align:start position:0% +lab or or G new octave uh code in a + + + align:start position:0% +lab or or G new octave uh code in a +production environment we certainly have + + align:start position:0% +production environment we certainly have + + + align:start position:0% +production environment we certainly have +seen that but often in the case one has + + align:start position:0% +seen that but often in the case one has + + + align:start position:0% +seen that but often in the case one has +limitations about what can deploy and so + + align:start position:0% +limitations about what can deploy and so + + + align:start position:0% +limitations about what can deploy and so +it is still better to do the algorithm + + align:start position:0% +it is still better to do the algorithm + + + align:start position:0% +it is still better to do the algorithm +development in this type of environment + + align:start position:0% +development in this type of environment + + + align:start position:0% +development in this type of environment +and than than to uh than to try and do + + align:start position:0% +and than than to uh than to try and do + + + align:start position:0% +and than than to uh than to try and do +the alment in in in a deployment + + align:start position:0% +the alment in in in a deployment + + + align:start position:0% +the alment in in in a deployment +language like + + align:start position:0% + + + + align:start position:0% + +Java one of the things that was very + + align:start position:0% +Java one of the things that was very + + + align:start position:0% +Java one of the things that was very +important + + align:start position:0% +important + + + align:start position:0% +important +for this database and it's true of most + + align:start position:0% +for this database and it's true of most + + + align:start position:0% +for this database and it's true of most +parallel + + align:start position:0% +parallel + + + align:start position:0% +parallel +databases so if we want to get the + + align:start position:0% +databases so if we want to get the + + + align:start position:0% +databases so if we want to get the +highest performance insert that is we + + align:start position:0% +highest performance insert that is we + + + align:start position:0% +highest performance insert that is we +want to you know read the data insert it + + align:start position:0% +want to you know read the data insert it + + + align:start position:0% +want to you know read the data insert it +as quickly as possible in the database + + align:start position:0% +as quickly as possible in the database + + + align:start position:0% +as quickly as possible in the database +typically we'll need to have some kind + + align:start position:0% +typically we'll need to have some kind + + + align:start position:0% +typically we'll need to have some kind +of parallel program running in this case + + align:start position:0% +of parallel program running in this case + + + align:start position:0% +of parallel program running in this case +maybe each reading different sets of + + align:start position:0% +maybe each reading different sets of + + + align:start position:0% +maybe each reading different sets of +input files and all inserting them into + + align:start position:0% +input files and all inserting them into + + + align:start position:0% +input files and all inserting them into +the parallel database and so in accumulo + + align:start position:0% +the parallel database and so in accumulo + + + align:start position:0% +the parallel database and so in accumulo +they divide your table amongst the + + align:start position:0% +they divide your table amongst the + + + align:start position:0% +they divide your table amongst the +different computers which they call + + align:start position:0% +different computers which they call + + + align:start position:0% +different computers which they call +tablet + + align:start position:0% +tablet + + + align:start position:0% +tablet +servers and it's very important to avoid + + align:start position:0% +servers and it's very important to avoid + + + align:start position:0% +servers and it's very important to avoid +the situation where everyone is + + align:start position:0% +the situation where everyone is + + + align:start position:0% +the situation where everyone is +inserting and all the data is inserting + + align:start position:0% +inserting and all the data is inserting + + + align:start position:0% +inserting and all the data is inserting +into the same tablet server you're not + + align:start position:0% +into the same tablet server you're not + + + align:start position:0% +into the same tablet server you're not +going to get really very good + + align:start position:0% +going to get really very good + + + align:start position:0% +going to get really very good +performance now the way a cumulo splits + + align:start position:0% +performance now the way a cumulo splits + + + align:start position:0% +performance now the way a cumulo splits +up its data is similar to many other + + align:start position:0% +up its data is similar to many other + + + align:start position:0% +up its data is similar to many other +databases it called it's called sharding + + align:start position:0% +databases it called it's called sharding + + + align:start position:0% +databases it called it's called sharding +sometimes they call it it's just means + + align:start position:0% +sometimes they call it it's just means + + + align:start position:0% +sometimes they call it it's just means +they split up the table but the term in + + align:start position:0% +they split up the table but the term in + + + align:start position:0% +they split up the table but the term in +the database Community use is they call + + align:start position:0% +the database Community use is they call + + + align:start position:0% +the database Community use is they call +it sharding what they'll do is they'll + + align:start position:0% +it sharding what they'll do is they'll + + + align:start position:0% +it sharding what they'll do is they'll +basically take the table and they'll + + align:start position:0% +basically take the table and they'll + + + align:start position:0% +basically take the table and they'll +sign certain row keys in this in a + + align:start position:0% +sign certain row keys in this in a + + + align:start position:0% +sign certain row keys in this in a +cumulous case certain contiguous sets of + + align:start position:0% +cumulous case certain contiguous sets of + + + align:start position:0% +cumulous case certain contiguous sets of +row keys to particular tablet + + align:start position:0% +row keys to particular tablet + + + align:start position:0% +row keys to particular tablet +servers so you know if you had a a data + + align:start position:0% +servers so you know if you had a a data + + + align:start position:0% +servers so you know if you had a a data +set that was + + align:start position:0% +set that was + + + align:start position:0% +set that was +universally uh uh split uh where over + + align:start position:0% +universally uh uh split uh where over + + + align:start position:0% +universally uh uh split uh where over +the alphabet then and you were going to + + align:start position:0% +the alphabet then and you were going to + + + align:start position:0% +the alphabet then and you were going to +split it the first split would be + + align:start position:0% +split it the first split would be + + + align:start position:0% +split it the first split would be +between you know m and n and so this is + + align:start position:0% +between you know m and n and so this is + + + align:start position:0% +between you know m and n and so this is +called splitting and it's very important + + align:start position:0% +called splitting and it's very important + + + align:start position:0% +called splitting and it's very important +to try and get good splits and choose + + align:start position:0% +to try and get good splits and choose + + + align:start position:0% +to try and get good splits and choose +your splits so that you get good + + align:start position:0% +your splits so that you get good + + + align:start position:0% +your splits so that you get good +performance now d4m has a native + + align:start position:0% +performance now d4m has a native + + + align:start position:0% +performance now d4m has a native +interface that allows you to just say + + align:start position:0% +interface that allows you to just say + + + align:start position:0% +interface that allows you to just say +here are the I want these to be the + + align:start position:0% +here are the I want these to be the + + + align:start position:0% +here are the I want these to be the +splits of this table you can actually + + align:start position:0% +splits of this table you can actually + + + align:start position:0% +splits of this table you can actually +compute those and then assign them if + + align:start position:0% +compute those and then assign them if + + + align:start position:0% +compute those and then assign them if +you have a parallel instance in the + + align:start position:0% +you have a parallel instance in the + + + align:start position:0% +you have a parallel instance in the +class you will only be working on the + + align:start position:0% +class you will only be working on the + + + align:start position:0% +class you will only be working on the +databases that we will be set up for you + + align:start position:0% +databases that we will be set up for you + + + align:start position:0% +databases that we will be set up for you +we have set up for you are all single + + align:start position:0% +we have set up for you are all single + + + align:start position:0% +we have set up for you are all single +node instances they do not have multiple + + align:start position:0% +node instances they do not have multiple + + + align:start position:0% +node instances they do not have multiple +tablet servers so you don't really have + + align:start position:0% +tablet servers so you don't really have + + + align:start position:0% +tablet servers so you don't really have +to do deal with splitting uh it's only + + align:start position:0% +to do deal with splitting uh it's only + + + align:start position:0% +to do deal with splitting uh it's only +an issue in parallel but it's certainly + + align:start position:0% +an issue in parallel but it's certainly + + + align:start position:0% +an issue in parallel but it's certainly +something to be aware of and as of the + + align:start position:0% +something to be aware of and as of the + + + align:start position:0% +something to be aware of and as of the +key you know people will often have a + + align:start position:0% +key you know people will often have a + + + align:start position:0% +key you know people will often have a +very large accumulo instance and they + + align:start position:0% +very large accumulo instance and they + + + align:start position:0% +very large accumulo instance and they +may only be getting not very you know + + align:start position:0% +may only be getting not very you know + + + align:start position:0% +may only be getting not very you know +the performance they would get on one on + + align:start position:0% +the performance they would get on one on + + + align:start position:0% +the performance they would get on one on +just a two node instance because and + + align:start position:0% +just a two node instance because and + + + align:start position:0% +just a two node instance because and +usually it's because their splitting + + align:start position:0% +usually it's because their splitting + + + align:start position:0% +usually it's because their splitting +needs to be done in this proper way and + + align:start position:0% +needs to be done in this proper way and + + + align:start position:0% +needs to be done in this proper way and +this is true of all databases not just + + align:start position:0% +this is true of all databases not just + + + align:start position:0% +this is true of all databases not just +accumulo but other databases have the + + align:start position:0% +accumulo but other databases have the + + + align:start position:0% +accumulo but other databases have the +exact same + + align:start position:0% + + + + align:start position:0% + +issue accumulo is called accumulo + + align:start position:0% +issue accumulo is called accumulo + + + align:start position:0% +issue accumulo is called accumulo +because it has something called + + align:start position:0% +because it has something called + + + align:start position:0% +because it has something called +accumulat + + align:start position:0% +accumulat + + + align:start position:0% +accumulat +which is what actually makes this whole + + align:start position:0% +which is what actually makes this whole + + + align:start position:0% +which is what actually makes this whole +bioinformatics application really go + + align:start position:0% +bioinformatics application really go + + + align:start position:0% +bioinformatics application really go +which is that I can denote a column in a + + align:start position:0% +which is that I can denote a column in a + + + align:start position:0% +which is that I can denote a column in a +table to be an accumulator column which + + align:start position:0% +table to be an accumulator column which + + + align:start position:0% +table to be an accumulator column which +means whenever a new entry is hit some + + align:start position:0% +means whenever a new entry is hit some + + + align:start position:0% +means whenever a new entry is hit some +action will be performed in this case + + align:start position:0% +action will be performed in this case + + + align:start position:0% +action will be performed in this case +the default is + + align:start position:0% +the default is + + + align:start position:0% +the default is +addition and so a standard thing we'll + + align:start position:0% +addition and so a standard thing we'll + + + align:start position:0% +addition and so a standard thing we'll +do in our schemas we've already talked + + align:start position:0% +do in our schemas we've already talked + + + align:start position:0% +do in our schemas we've already talked +about these exploded transpose pair + + align:start position:0% +about these exploded transpose pair + + + align:start position:0% +about these exploded transpose pair +schemas that allow us to do fast lookups + + align:start position:0% +schemas that allow us to do fast lookups + + + align:start position:0% +schemas that allow us to do fast lookups +and rows and columns is it will create + + align:start position:0% +and rows and columns is it will create + + + align:start position:0% +and rows and columns is it will create +two additional tables one of which holds + + align:start position:0% +two additional tables one of which holds + + + align:start position:0% +two additional tables one of which holds +the sums of the rows and one of which + + align:start position:0% +the sums of the rows and one of which + + + align:start position:0% +the sums of the rows and one of which +holds the sums of the columns which then + + align:start position:0% +holds the sums of the columns which then + + + align:start position:0% +holds the sums of the columns which then +allows us to do these very fast lookups + + align:start position:0% +allows us to do these very fast lookups + + + align:start position:0% +allows us to do these very fast lookups +of the statistics which is very useful + + align:start position:0% +of the statistics which is very useful + + + align:start position:0% +of the statistics which is very useful +to know how do we avoid accidentally + + align:start position:0% +to know how do we avoid accidentally + + + align:start position:0% +to know how do we avoid accidentally +looking up columns that we'll have that + + align:start position:0% +looking up columns that we'll have that + + + align:start position:0% +looking up columns that we'll have that +are present in the whole database an + + align:start position:0% +are present in the whole database an + + + align:start position:0% +are present in the whole database an +issue that happens all the time is that + + align:start position:0% +issue that happens all the time is that + + + align:start position:0% +issue that happens all the time is that +you'll have a column that's essentially + + align:start position:0% +you'll have a column that's essentially + + + align:start position:0% +you'll have a column that's essentially +almost a dense column in the database + + align:start position:0% +almost a dense column in the database + + + align:start position:0% +almost a dense column in the database +and you really really really don't want + + align:start position:0% +and you really really really don't want + + + align:start position:0% +and you really really really don't want +to look that up because it's basically + + align:start position:0% +to look that up because it's basically + + + align:start position:0% +to look that up because it's basically +giving you the whole database well with + + align:start position:0% +giving you the whole database well with + + + align:start position:0% +giving you the whole database well with +this accumulator you can look up the + + align:start position:0% +this accumulator you can look up the + + + align:start position:0% +this accumulator you can look up the +column first and it will give you a + + align:start position:0% +column first and it will give you a + + + align:start position:0% +column first and it will give you a +count and be like oh yeah and then you + + align:start position:0% +count and be like oh yeah and then you + + + align:start position:0% +count and be like oh yeah and then you +can just say nope I want to look up + + align:start position:0% +can just say nope I want to look up + + + align:start position:0% +can just say nope I want to look up +everything but that column so very + + align:start position:0% +everything but that column so very + + + align:start position:0% +everything but that column so very +powerful very powerful tool for doing + + align:start position:0% +powerful very powerful tool for doing + + + align:start position:0% +powerful very powerful tool for doing +that that's also another reason why we + + align:start position:0% +that that's also another reason why we + + + align:start position:0% +that that's also another reason why we +construct the associative array when we + + align:start position:0% +construct the associative array when we + + + align:start position:0% +construct the associative array when we +load it for insert because we when we + + align:start position:0% +load it for insert because we when we + + + align:start position:0% +load it for insert because we when we +construct the associa ray we can + + align:start position:0% +construct the associa ray we can + + + align:start position:0% +construct the associa ray we can +actually do a a quick sum right then and + + align:start position:0% +actually do a a quick sum right then and + + + align:start position:0% +actually do a a quick sum right then and +there of whatever piece we've rent in + + align:start position:0% +there of whatever piece we've rent in + + + align:start position:0% +there of whatever piece we've rent in +and so then when we send that into the + + align:start position:0% +and so then when we send that into the + + + align:start position:0% +and so then when we send that into the +database we've dramatically reduced the + + align:start position:0% +database we've dramatically reduced the + + + align:start position:0% +database we've dramatically reduced the +number of the amount of tallying it has + + align:start position:0% +number of the amount of tallying it has + + + align:start position:0% +number of the amount of tallying it has +to do and this can be a huge timesaver + + align:start position:0% +to do and this can be a huge timesaver + + + align:start position:0% +to do and this can be a huge timesaver +because uh if you don't do that you're + + align:start position:0% +because uh if you don't do that you're + + + align:start position:0% +because uh if you don't do that you're +essentially re inserting the data two + + align:start position:0% +essentially re inserting the data two + + + align:start position:0% +essentially re inserting the data two +more times because you know when you + + align:start position:0% +more times because you know when you + + + align:start position:0% +more times because you know when you +you've inserted it into the the the + + align:start position:0% +you've inserted it into the the the + + + align:start position:0% +you've inserted it into the the the +table and it's transpose and to get the + + align:start position:0% +table and it's transpose and to get the + + + align:start position:0% +table and it's transpose and to get the +accumulation effect you would have to + + align:start position:0% +accumulation effect you would have to + + + align:start position:0% +accumulation effect you would have to +directly insert it but if we can do a + + align:start position:0% +directly insert it but if we can do a + + + align:start position:0% +directly insert it but if we can do a +preum that reduces the amount of worked + + align:start position:0% +preum that reduces the amount of worked + + + align:start position:0% +preum that reduces the amount of worked +on that uh on that uh on that + + align:start position:0% +on that uh on that uh on that + + + align:start position:0% +on that uh on that uh on that +accumulator table dramatically and so + + align:start position:0% +accumulator table dramatically and so + + + align:start position:0% +accumulator table dramatically and so +again that's another reason why we we do + + align:start position:0% + + + + align:start position:0% + +that so let's just talk about some of + + align:start position:0% +that so let's just talk about some of + + + align:start position:0% +that so let's just talk about some of +the results that we see so here's an + + align:start position:0% +the results that we see so here's an + + + align:start position:0% +the results that we see so here's an +example on a uh let's see this is an 8 + + align:start position:0% +example on a uh let's see this is an 8 + + + align:start position:0% +example on a uh let's see this is an 8 +no database and this shows us the ingest + + align:start position:0% +no database and this shows us the ingest + + + align:start position:0% +no database and this shows us the ingest +rate that we get using different numbers + + align:start position:0% +rate that we get using different numbers + + + align:start position:0% +rate that we get using different numbers +of ingestor so this is different + + align:start position:0% +of ingestor so this is different + + + align:start position:0% +of ingestor so this is different +programs all trying to insert into this + + align:start position:0% +programs all trying to insert into this + + + align:start position:0% +programs all trying to insert into this +database simultaneously and this just + + align:start position:0% +database simultaneously and this just + + + align:start position:0% +database simultaneously and this just +shows the difference between having um + + align:start position:0% +shows the difference between having um + + + align:start position:0% +shows the difference between having um +uh uh zero splits and uh in this case 35 + + align:start position:0% +uh uh zero splits and uh in this case 35 + + + align:start position:0% +uh uh zero splits and uh in this case 35 +splits is is was the was the optimal + + align:start position:0% +splits is is was the was the optimal + + + align:start position:0% +splits is is was the was the optimal +number that we had and you see it's a + + align:start position:0% +number that we had and you see it's a + + + align:start position:0% +number that we had and you see it's a +rather large uh uh difference um and you + + align:start position:0% +rather large uh uh difference um and you + + + align:start position:0% +rather large uh uh difference um and you +don't get you know you get some benefit + + align:start position:0% +don't get you know you get some benefit + + + align:start position:0% +don't get you know you get some benefit +with multiple inserters but that sort of + + align:start position:0% +with multiple inserters but that sort of + + + align:start position:0% +with multiple inserters but that sort of +ends when you uh when you don't do this + + align:start position:0% +ends when you uh when you don't do this + + + align:start position:0% +ends when you uh when you don't do this +so this is just an example of why you + + align:start position:0% +so this is just an example of why you + + + align:start position:0% +so this is just an example of why you +want to do + + align:start position:0% +want to do + + + align:start position:0% +want to do +that another example is uh with is the + + align:start position:0% +that another example is uh with is the + + + align:start position:0% +that another example is uh with is the +actual human DNA database this shows us + + align:start position:0% +actual human DNA database this shows us + + + align:start position:0% +actual human DNA database this shows us +our insert rate um uh on doing using + + align:start position:0% +our insert rate um uh on doing using + + + align:start position:0% +our insert rate um uh on doing using +different numbers of uh of + + align:start position:0% +different numbers of uh of + + + align:start position:0% +different numbers of uh of +uh of uh + + align:start position:0% +uh of uh + + + align:start position:0% +uh of uh +inserters and uh oh yeah so this is this + + align:start position:0% +inserters and uh oh yeah so this is this + + + align:start position:0% +inserters and uh oh yeah so this is this +is eight tablet servers and this just + + align:start position:0% +is eight tablet servers and this just + + + align:start position:0% +is eight tablet servers and this just +shows the different number of ingestor + + align:start position:0% +shows the different number of ingestor + + + align:start position:0% +shows the different number of ingestor +here and since we're doing proper + + align:start position:0% +here and since we're doing proper + + + align:start position:0% +here and since we're doing proper +splitting we're getting very nice uh + + align:start position:0% +splitting we're getting very nice uh + + + align:start position:0% +splitting we're getting very nice uh +scaling and this is actually the actual + + align:start position:0% +scaling and this is actually the actual + + + align:start position:0% +scaling and this is actually the actual +output from uh from aimul though it + + align:start position:0% +output from uh from aimul though it + + + align:start position:0% +output from uh from aimul though it +actually has a nice little meter here + + align:start position:0% +actually has a nice little meter here + + + align:start position:0% +actually has a nice little meter here +that shows you what it says you're + + align:start position:0% +that shows you what it says you're + + + align:start position:0% +that shows you what it says you're +actually getting which is very very nice + + align:start position:0% +actually getting which is very very nice + + + align:start position:0% +actually getting which is very very nice +to to be able to verify that you know + + align:start position:0% +to to be able to verify that you know + + + align:start position:0% +to to be able to verify that you know +that you and the database both agree + + align:start position:0% +that you and the database both agree + + + align:start position:0% +that you and the database both agree +that your insert rate is uh so this is + + align:start position:0% +that your insert rate is uh so this is + + + align:start position:0% +that your insert rate is uh so this is +insert rate here so you see we're + + align:start position:0% +insert rate here so you see we're + + + align:start position:0% +insert rate here so you see we're +getting about 4,000 400,000 entries per + + align:start position:0% +getting about 4,000 400,000 entries per + + + align:start position:0% +getting about 4,000 400,000 entries per +second which is an extraordinarily High + + align:start position:0% +second which is an extraordinarily High + + + align:start position:0% +second which is an extraordinarily High +number in the database Community uh just + + align:start position:0% +number in the database Community uh just + + + align:start position:0% +number in the database Community uh just +to give you a comparison uh it would not + + align:start position:0% +to give you a comparison uh it would not + + + align:start position:0% +to give you a comparison uh it would not +be uncommon if you were to set up a + + align:start position:0% +be uncommon if you were to set up a + + + align:start position:0% +be uncommon if you were to set up a +MySQL instance on a single computer and + + align:start position:0% +MySQL instance on a single computer and + + + align:start position:0% +MySQL instance on a single computer and +have one inserter going into it to get + + align:start position:0% +have one inserter going into it to get + + + align:start position:0% +have one inserter going into it to get +maybe a thousand inserts per second on a + + align:start position:0% +maybe a thousand inserts per second on a + + + align:start position:0% +maybe a thousand inserts per second on a +good day and so you know this is this is + + align:start position:0% +good day and so you know this is this is + + + align:start position:0% +good day and so you know this is this is +essentially the core reason why people + + align:start position:0% +essentially the core reason why people + + + align:start position:0% +essentially the core reason why people +use a cumulo is because of this very + + align:start position:0% +use a cumulo is because of this very + + + align:start position:0% +use a cumulo is because of this very +high insert and and query performance um + + align:start position:0% +high insert and and query performance um + + + align:start position:0% +high insert and and query performance um +and this just shows our extrapolated + + align:start position:0% +and this just shows our extrapolated + + + align:start position:0% +and this just shows our extrapolated +runtime if we wanted to for instance + + align:start position:0% +runtime if we wanted to for instance + + + align:start position:0% +runtime if we wanted to for instance +ingest the entire human uh uh fast uh + + align:start position:0% +ingest the entire human uh uh fast uh + + + align:start position:0% +ingest the entire human uh uh fast uh +database here a 4.5 billion entries uh + + align:start position:0% +database here a 4.5 billion entries uh + + + align:start position:0% +database here a 4.5 billion entries uh +we could do that in you know eight hours + + align:start position:0% +we could do that in you know eight hours + + + align:start position:0% +we could do that in you know eight hours +which would be a very reasonable amount + + align:start position:0% +which would be a very reasonable amount + + + align:start position:0% +which would be a very reasonable amount +of time to do that so in summary what we + + align:start position:0% +of time to do that so in summary what we + + + align:start position:0% +of time to do that so in summary what we +were able to achieve with this + + align:start position:0% +were able to achieve with this + + + align:start position:0% +were able to achieve with this +application + + align:start position:0% +application + + + align:start position:0% +application +is this shows one of these diagrams I + + align:start position:0% +is this shows one of these diagrams I + + + align:start position:0% +is this shows one of these diagrams I +think I showed one in the first lecture + + align:start position:0% +think I showed one in the first lecture + + + align:start position:0% +think I showed one in the first lecture +this is a way of of sort of measuring + + align:start position:0% +this is a way of of sort of measuring + + + align:start position:0% +this is a way of of sort of measuring +our productivity and our performance so + + align:start position:0% +our productivity and our performance so + + + align:start position:0% +our productivity and our performance so +this shows the volume of code that we + + align:start position:0% +this shows the volume of code that we + + + align:start position:0% +this shows the volume of code that we +wrote and this shows the runtime so + + align:start position:0% +wrote and this shows the runtime so + + + align:start position:0% +wrote and this shows the runtime so +obviously this is better down here and + + align:start position:0% +obviously this is better down here and + + + align:start position:0% +obviously this is better down here and +this shows blast so blast is the + + align:start position:0% +this shows blast so blast is the + + + align:start position:0% +this shows blast so blast is the +industry standard application for doing + + align:start position:0% +industry standard application for doing + + + align:start position:0% +industry standard application for doing +sequence match and I don't want in any + + align:start position:0% +sequence match and I don't want in any + + + align:start position:0% +sequence match and I don't want in any +way to say that we are doing everything + + align:start position:0% +way to say that we are doing everything + + + align:start position:0% +way to say that we are doing everything +blast does blast is almost a million + + align:start position:0% +blast does blast is almost a million + + + align:start position:0% +blast does blast is almost a million +lines of code it does lots and lots of + + align:start position:0% +lines of code it does lots and lots of + + + align:start position:0% +lines of code it does lots and lots of +different things it handles all + + align:start position:0% +different things it handles all + + + align:start position:0% +different things it handles all +different types of file formats and + + align:start position:0% +different types of file formats and + + + align:start position:0% +different types of file formats and +little nuances and other types of things + + align:start position:0% +little nuances and other types of things + + + align:start position:0% +little nuances and other types of things +but at its core it does what we did and + + align:start position:0% +but at its core it does what we did and + + + align:start position:0% +but at its core it does what we did and +in and we were able to basically do that + + align:start position:0% +in and we were able to basically do that + + + align:start position:0% +in and we were able to basically do that +in you + + align:start position:0% +in you + + + align:start position:0% +in you +know 150 lines of d4m + + align:start position:0% +know 150 lines of d4m + + + align:start position:0% +know 150 lines of d4m +code and using the database we were able + + align:start position:0% +code and using the database we were able + + + align:start position:0% +code and using the database we were able +to do + + align:start position:0% +to do + + + align:start position:0% +to do +that a 100 times faster and so this is + + align:start position:0% +that a 100 times faster and so this is + + + align:start position:0% +that a 100 times faster and so this is +really the power of this technology is + + align:start position:0% +really the power of this technology is + + + align:start position:0% +really the power of this technology is +to allow you to develop these algorithms + + align:start position:0% +to allow you to develop these algorithms + + + align:start position:0% +to allow you to develop these algorithms +and and Implement them and in in this + + align:start position:0% +and and Implement them and in in this + + + align:start position:0% +and and Implement them and in in this +case actually you leverage the database + + align:start position:0% +case actually you leverage the database + + + align:start position:0% +case actually you leverage the database +to essentially replace lookups with + + align:start position:0% +to essentially replace lookups with + + + align:start position:0% +to essentially replace lookups with +computations in a very intelligent way + + align:start position:0% +computations in a very intelligent way + + + align:start position:0% +computations in a very intelligent way +in a way that's knowledgeable about the + + align:start position:0% +in a way that's knowledgeable about the + + + align:start position:0% +in a way that's knowledgeable about the +statistics of your data um and that's + + align:start position:0% +statistics of your data um and that's + + + align:start position:0% +statistics of your data um and that's +really the power and these are the types + + align:start position:0% +really the power and these are the types + + + align:start position:0% +really the power and these are the types +of results that people can get and this + + align:start position:0% +of results that people can get and this + + + align:start position:0% +of results that people can get and this +whole result was done with one summer + + align:start position:0% +whole result was done with one summer + + + align:start position:0% +whole result was done with one summer +student you know very smart summer + + align:start position:0% +student you know very smart summer + + + align:start position:0% +student you know very smart summer +student but you know we were able to put + + align:start position:0% +student but you know we were able to put + + + align:start position:0% +student but you know we were able to put +this whole system together in about a + + align:start position:0% +this whole system together in about a + + + align:start position:0% +this whole system together in about a +couple of months and this is from a + + align:start position:0% +couple of months and this is from a + + + align:start position:0% +couple of months and this is from a +person who knew nothing about accumulo + + align:start position:0% +person who knew nothing about accumulo + + + align:start position:0% +person who knew nothing about accumulo +or deform or anything like that they + + align:start position:0% +or deform or anything like that they + + + align:start position:0% +or deform or anything like that they +were a good they were smart they had a + + align:start position:0% +were a good they were smart they had a + + + align:start position:0% +were a good they were smart they had a +they were good uh good solid Java + + align:start position:0% +they were good uh good solid Java + + + align:start position:0% +they were good uh good solid Java +background and and very energetic but + + align:start position:0% +background and and very energetic but + + + align:start position:0% +background and and very energetic but +you know these are the kinds of things + + align:start position:0% +you know these are the kinds of things + + + align:start position:0% +you know these are the kinds of things +we've been able to + + align:start position:0% +we've been able to + + + align:start position:0% +we've been able to +see so just to summarize you know we + + align:start position:0% +see so just to summarize you know we + + + align:start position:0% +see so just to summarize you know we +again we see uh See uh + + align:start position:0% +again we see uh See uh + + + align:start position:0% +again we see uh See uh +uh uh you know I think just to uh you + + align:start position:0% +uh uh you know I think just to uh you + + + align:start position:0% +uh uh you know I think just to uh you +know we we this types of techniques are + + align:start position:0% +know we we this types of techniques are + + + align:start position:0% +know we we this types of techniques are +useful for document analysis and network + + align:start position:0% +useful for document analysis and network + + + align:start position:0% +useful for document analysis and network +analysis and DNA + + align:start position:0% +analysis and DNA + + + align:start position:0% +analysis and DNA +sequencing um you know this is really + + align:start position:0% +sequencing um you know this is really + + + align:start position:0% +sequencing um you know this is really +summarizing all the applications that + + align:start position:0% +summarizing all the applications that + + + align:start position:0% +summarizing all the applications that +we've talked about you know we we think + + align:start position:0% +we've talked about you know we we think + + + align:start position:0% +we've talked about you know we we think +there's a pretty big gap between doing + + align:start position:0% +there's a pretty big gap between doing + + + align:start position:0% +there's a pretty big gap between doing +the data analysis tools that are really + + align:start position:0% +the data analysis tools that are really + + + align:start position:0% +the data analysis tools that are really +algorithm developers need and really + + align:start position:0% +algorithm developers need and really + + + align:start position:0% +algorithm developers need and really +think d4m is really allowing us to use a + + align:start position:0% +think d4m is really allowing us to use a + + + align:start position:0% +think d4m is really allowing us to use a +tool like mat lab for its traditional + + align:start position:0% +tool like mat lab for its traditional + + + align:start position:0% +tool like mat lab for its traditional +role in this new domain which is + + align:start position:0% +role in this new domain which is + + + align:start position:0% +role in this new domain which is +algorithm development figure things out + + align:start position:0% +algorithm development figure things out + + + align:start position:0% +algorithm development figure things out +getting things right before you can then + + align:start position:0% +getting things right before you can then + + + align:start position:0% +getting things right before you can then +hand it on to someone else to you know + + align:start position:0% +hand it on to someone else to you know + + + align:start position:0% +hand it on to someone else to you know +Implement and and actually you know get + + align:start position:0% +Implement and and actually you know get + + + align:start position:0% +Implement and and actually you know get +in a production + + align:start position:0% +in a production + + + align:start position:0% +in a production +environment so with that that brings the + + align:start position:0% +environment so with that that brings the + + + align:start position:0% +environment so with that that brings the +end to the lecture and then there's some + + align:start position:0% +end to the lecture and then there's some + + + align:start position:0% +end to the lecture and then there's some +examples where we show you the the this + + align:start position:0% +examples where we show you the the this + + + align:start position:0% +examples where we show you the the this +this stuff so uh and there's no homework + + align:start position:0% +this stuff so uh and there's no homework + + + align:start position:0% +this stuff so uh and there's no homework +uh other than I sent you all that + + align:start position:0% +uh other than I sent you all that + + + align:start position:0% +uh other than I sent you all that +link to see if your access to the + + align:start position:0% +link to see if your access to the + + + align:start position:0% +link to see if your access to the +database exists did everyone raise your + + align:start position:0% +database exists did everyone raise your + + + align:start position:0% +database exists did everyone raise your +hand did you check the link out yes you + + align:start position:0% +hand did you check the link out yes you + + + align:start position:0% +hand did you check the link out yes you +logged in it worked you saw a bunch of + + align:start position:0% +logged in it worked you saw a bunch of + + + align:start position:0% +logged in it worked you saw a bunch of +databases there okay it doesn't work cu + + align:start position:0% +databases there okay it doesn't work cu + + + align:start position:0% +databases there okay it doesn't work cu +the next class is the sort of the + + align:start position:0% +the next class is the sort of the + + + align:start position:0% +the next class is the sort of the +penultimate class I'm going to go + + align:start position:0% +penultimate class I'm going to go + + + align:start position:0% +penultimate class I'm going to go +through all these examples and the + + align:start position:0% +through all these examples and the + + + align:start position:0% +through all these examples and the +assignment will be to run those examples + + align:start position:0% +assignment will be to run those examples + + + align:start position:0% +assignment will be to run those examples +on those databases so you will be really + + align:start position:0% +on those databases so you will be really + + + align:start position:0% +on those databases so you will be really +using DM touching a database doing real + + align:start position:0% +using DM touching a database doing real + + + align:start position:0% +using DM touching a database doing real +analytics doing very complicated things + + align:start position:0% +analytics doing very complicated things + + + align:start position:0% +analytics doing very complicated things +the whole class is just going to be a + + align:start position:0% +the whole class is just going to be a + + + align:start position:0% +the whole class is just going to be a +demonstration of that well everything + + align:start position:0% +demonstration of that well everything + + + align:start position:0% +demonstration of that well everything +we've been doing has been leading up so + + align:start position:0% +we've been doing has been leading up so + + + align:start position:0% +we've been doing has been leading up so +the concepts are in place so that you + + align:start position:0% +the concepts are in place so that you + + + align:start position:0% +the concepts are in place so that you +can understand those examples fairly + + align:start position:0% +can understand those examples fairly + + + align:start position:0% +can understand those examples fairly +easily all right so we will take a short + + align:start position:0% +easily all right so we will take a short + + + align:start position:0% +easily all right so we will take a short +break here and then uh we will come back + + align:start position:0% +break here and then uh we will come back + + + align:start position:0% +break here and then uh we will come back +and I will show you the demo uh this + + align:start position:0% +and I will show you the demo uh this + + + align:start position:0% +and I will show you the demo uh this +this week's demo \ No newline at end of file diff --git a/hd4roBsrYA8.txt b/hd4roBsrYA8.txt new file mode 100644 index 0000000000000000000000000000000000000000..42ad613a6d5c25478b747311b2a5431088141c33 --- /dev/null +++ b/hd4roBsrYA8.txt @@ -0,0 +1,3659 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu um my name is James ji I + + align:start position:0% +ocw.mit.edu um my name is James ji I + + + align:start position:0% +ocw.mit.edu um my name is James ji I +worked with sedarian and jnu on this uh + + align:start position:0% +worked with sedarian and jnu on this uh + + + align:start position:0% +worked with sedarian and jnu on this uh +project and what we did is we took a + + align:start position:0% +project and what we did is we took a + + + align:start position:0% +project and what we did is we took a +numerical simulation electrochemical + + align:start position:0% +numerical simulation electrochemical + + + align:start position:0% +numerical simulation electrochemical +simulation of a battery and ported it to + + align:start position:0% +simulation of a battery and ported it to + + + align:start position:0% +simulation of a battery and ported it to +the PlayStation + + align:start position:0% +the PlayStation + + + align:start position:0% +the PlayStation +3 and so the objective of this project + + align:start position:0% +3 and so the objective of this project + + + align:start position:0% +3 and so the objective of this project +for this situation was to Port a uh + + align:start position:0% +for this situation was to Port a uh + + + align:start position:0% +for this situation was to Port a uh +electrochemical battery simulation to + + align:start position:0% +electrochemical battery simulation to + + + align:start position:0% +electrochemical battery simulation to +the PlayStation 3 and uh try to take + + align:start position:0% +the PlayStation 3 and uh try to take + + + align:start position:0% +the PlayStation 3 and uh try to take +advantage of the unique features of the + + align:start position:0% +advantage of the unique features of the + + + align:start position:0% +advantage of the unique features of the +cell processor to help speed up the + + align:start position:0% +cell processor to help speed up the + + + align:start position:0% +cell processor to help speed up the +computation of the uh simulation so when + + align:start position:0% +computation of the uh simulation so when + + + align:start position:0% +computation of the uh simulation so when +we talk today we're going to talk about + + align:start position:0% +we talk today we're going to talk about + + + align:start position:0% +we talk today we're going to talk about +why we want to do that uh we're going to + + align:start position:0% +why we want to do that uh we're going to + + + align:start position:0% +why we want to do that uh we're going to +discuss the model we're going to discuss + + align:start position:0% +discuss the model we're going to discuss + + + align:start position:0% +discuss the model we're going to discuss +how we uh solved it numerically + + align:start position:0% +how we uh solved it numerically + + + align:start position:0% +how we uh solved it numerically +uh look at some of our performance + + align:start position:0% +uh look at some of our performance + + + align:start position:0% +uh look at some of our performance +results and then discuss what we wish we + + align:start position:0% +results and then discuss what we wish we + + + align:start position:0% +results and then discuss what we wish we +could have + + align:start position:0% +could have + + + align:start position:0% +could have +implemented okay so the justification is + + align:start position:0% +implemented okay so the justification is + + + align:start position:0% +implemented okay so the justification is +basically the world uh needs energy and + + align:start position:0% +basically the world uh needs energy and + + + align:start position:0% +basically the world uh needs energy and +oil has been in the news a lot and + + align:start position:0% +oil has been in the news a lot and + + + align:start position:0% +oil has been in the news a lot and +hasn't been as uh uh reliable source of + + align:start position:0% +hasn't been as uh uh reliable source of + + + align:start position:0% +hasn't been as uh uh reliable source of +energy as we'd like so in the automotive + + align:start position:0% +energy as we'd like so in the automotive + + + align:start position:0% +energy as we'd like so in the automotive +industry hybrids seem to be part of the + + align:start position:0% +industry hybrids seem to be part of the + + + align:start position:0% +industry hybrids seem to be part of the +solution to the uh energy needs now one + + align:start position:0% +solution to the uh energy needs now one + + + align:start position:0% +solution to the uh energy needs now one +of the problems with hybrids is how much + + align:start position:0% +of the problems with hybrids is how much + + + align:start position:0% +of the problems with hybrids is how much +energy is in your battery so the more + + align:start position:0% +energy is in your battery so the more + + + align:start position:0% +energy is in your battery so the more +sophisticated battery model that we can + + align:start position:0% +sophisticated battery model that we can + + + align:start position:0% +sophisticated battery model that we can +put in a hybrid the better that we're + + align:start position:0% +put in a hybrid the better that we're + + + align:start position:0% +put in a hybrid the better that we're +going to be off so uh the a more + + align:start position:0% +going to be off so uh the a more + + + align:start position:0% +going to be off so uh the a more +sophisticated model requires more + + align:start position:0% +sophisticated model requires more + + + align:start position:0% +sophisticated model requires more +computation so you're looking at having + + align:start position:0% +computation so you're looking at having + + + align:start position:0% +computation so you're looking at having +a large supercal processor in your car + + align:start position:0% +a large supercal processor in your car + + + align:start position:0% +a large supercal processor in your car +or you could get see if you could get a + + align:start position:0% +or you could get see if you could get a + + + align:start position:0% +or you could get see if you could get a +lot of small processors to do the same + + align:start position:0% +lot of small processors to do the same + + + align:start position:0% +lot of small processors to do the same +amount of work and the cell represents + + align:start position:0% +amount of work and the cell represents + + + align:start position:0% +amount of work and the cell represents +the kind of the first opportunity to be + + align:start position:0% +the kind of the first opportunity to be + + + align:start position:0% +the kind of the first opportunity to be +able to test that out so the simulation + + align:start position:0% +able to test that out so the simulation + + + align:start position:0% +able to test that out so the simulation +that we ran uh basically consisted of a + + align:start position:0% +that we ran uh basically consisted of a + + + align:start position:0% +that we ran uh basically consisted of a +lead acid battery a cell so un + + align:start position:0% +lead acid battery a cell so un + + + align:start position:0% +lead acid battery a cell so un +fortunately they use the word cell and + + align:start position:0% +fortunately they use the word cell and + + + align:start position:0% +fortunately they use the word cell and +we're also using the word cell so it's + + align:start position:0% +we're also using the word cell so it's + + + align:start position:0% +we're also using the word cell so it's +sort of like the Modern Day Smurf but um + + align:start position:0% +sort of like the Modern Day Smurf but um + + + align:start position:0% +sort of like the Modern Day Smurf but um +so in a Le a battery cell you have a + + align:start position:0% +so in a Le a battery cell you have a + + + align:start position:0% +so in a Le a battery cell you have a +lead dioxide electrode which consists of + + align:start position:0% +lead dioxide electrode which consists of + + + align:start position:0% +lead dioxide electrode which consists of +a number of Parts a lead electrode which + + align:start position:0% +a number of Parts a lead electrode which + + + align:start position:0% +a number of Parts a lead electrode which +also consists of a number of parts and + + align:start position:0% +also consists of a number of parts and + + + align:start position:0% +also consists of a number of parts and +an electrolyte which is five mol + + align:start position:0% +an electrolyte which is five mol + + + align:start position:0% +an electrolyte which is five mol +sulfuric acid which consists of + + align:start position:0% +sulfuric acid which consists of + + + align:start position:0% +sulfuric acid which consists of +h204 okay um when you discharge the + + align:start position:0% +h204 okay um when you discharge the + + + align:start position:0% +h204 okay um when you discharge the +battery you're going to close the + + align:start position:0% +battery you're going to close the + + + align:start position:0% +battery you're going to close the +circuit and basically what ends up + + align:start position:0% +circuit and basically what ends up + + + align:start position:0% +circuit and basically what ends up +happening is you have electrons flowing + + align:start position:0% +happening is you have electrons flowing + + + align:start position:0% +happening is you have electrons flowing +on the Outer Loop and between the + + align:start position:0% +on the Outer Loop and between the + + + align:start position:0% +on the Outer Loop and between the +electrodes you're going to have uh an + + align:start position:0% +electrodes you're going to have uh an + + + align:start position:0% +electrodes you're going to have uh an +ionic current so uh you have a complete + + align:start position:0% +ionic current so uh you have a complete + + + align:start position:0% +ionic current so uh you have a complete +circuit around your Loop and this is the + + align:start position:0% +circuit around your Loop and this is the + + + align:start position:0% +circuit around your Loop and this is the +effect that the simulation is trying to + + align:start position:0% +effect that the simulation is trying to + + + align:start position:0% +effect that the simulation is trying to +simulate the simulation works on a + + align:start position:0% +simulate the simulation works on a + + + align:start position:0% +simulate the simulation works on a +uh uh uh very low physical level and it + + align:start position:0% +uh uh uh very low physical level and it + + + align:start position:0% +uh uh uh very low physical level and it +stimulates the chemical reactions which + + align:start position:0% +stimulates the chemical reactions which + + + align:start position:0% +stimulates the chemical reactions which +at the lead dioxide electrode it + + align:start position:0% +at the lead dioxide electrode it + + + align:start position:0% +at the lead dioxide electrode it +converts lead dioxide into lead sulfate + + align:start position:0% +converts lead dioxide into lead sulfate + + + align:start position:0% +converts lead dioxide into lead sulfate +during this charge reverses it during + + align:start position:0% +during this charge reverses it during + + + align:start position:0% +during this charge reverses it during +charge during uh discharge the lead + + align:start position:0% +charge during uh discharge the lead + + + align:start position:0% +charge during uh discharge the lead +electrode turns lead into lead sulfate + + align:start position:0% +electrode turns lead into lead sulfate + + + align:start position:0% +electrode turns lead into lead sulfate +and during recharge it converts that + + align:start position:0% +and during recharge it converts that + + + align:start position:0% +and during recharge it converts that +back + + align:start position:0% +back + + + align:start position:0% +back +uh to implement the model we took + + align:start position:0% +uh to implement the model we took + + + align:start position:0% +uh to implement the model we took +basically and discretized the system and + + align:start position:0% +basically and discretized the system and + + + align:start position:0% +basically and discretized the system and +just kind of cross-sectioned it okay + + align:start position:0% +just kind of cross-sectioned it okay + + + align:start position:0% +just kind of cross-sectioned it okay +took small sections and cross-sectioned + + align:start position:0% +took small sections and cross-sectioned + + + align:start position:0% +took small sections and cross-sectioned +it um we're going to skip this slide + + align:start position:0% +it um we're going to skip this slide + + + align:start position:0% +it um we're going to skip this slide +make any sense but basically to to uh + + align:start position:0% +make any sense but basically to to uh + + + align:start position:0% +make any sense but basically to to uh +simulate the physics we have a bunch of + + align:start position:0% +simulate the physics we have a bunch of + + + align:start position:0% +simulate the physics we have a bunch of +nasty nonlinear coupled partial + + align:start position:0% +nasty nonlinear coupled partial + + + align:start position:0% +nasty nonlinear coupled partial +differential equations this is an + + align:start position:0% +differential equations this is an + + + align:start position:0% +differential equations this is an +example of two of them and uh there a + + align:start position:0% +example of two of them and uh there a + + + align:start position:0% +example of two of them and uh there a +number of other ones that are included + + align:start position:0% +number of other ones that are included + + + align:start position:0% +number of other ones that are included +in the system but not really worth + + align:start position:0% +in the system but not really worth + + + align:start position:0% +in the system but not really worth +seeing just kind of a feel you get uh + + align:start position:0% +seeing just kind of a feel you get uh + + + align:start position:0% +seeing just kind of a feel you get uh +you see a a a diffusion term you see in + + align:start position:0% +you see a a a diffusion term you see in + + + align:start position:0% +you see a a a diffusion term you see in +the lower equation you see a diffusion + + align:start position:0% +the lower equation you see a diffusion + + + align:start position:0% +the lower equation you see a diffusion +term you see a reaction term and the + + align:start position:0% +term you see a reaction term and the + + + align:start position:0% +term you see a reaction term and the +upper equation you see uh changing of + + align:start position:0% +upper equation you see uh changing of + + + align:start position:0% +upper equation you see uh changing of +the paracity changing the geometry of + + align:start position:0% +the paracity changing the geometry of + + + align:start position:0% +the paracity changing the geometry of +the system this is kind of the output + + align:start position:0% +the system this is kind of the output + + + align:start position:0% +the system this is kind of the output +that you could get from this type of + + align:start position:0% +that you could get from this type of + + + align:start position:0% +that you could get from this type of +battery + + align:start position:0% +battery + + + align:start position:0% +battery +simulation uh and what you're looking at + + align:start position:0% +simulation uh and what you're looking at + + + align:start position:0% +simulation uh and what you're looking at +here is you're looking at if the left + + align:start position:0% +here is you're looking at if the left + + + align:start position:0% +here is you're looking at if the left +hand side is the uh electrodes is the + + align:start position:0% +hand side is the uh electrodes is the + + + align:start position:0% +hand side is the uh electrodes is the +top of the battery uh and the height of + + align:start position:0% +top of the battery uh and the height of + + + align:start position:0% +top of the battery uh and the height of +the battery goes along that way you see + + align:start position:0% +the battery goes along that way you see + + + align:start position:0% +the battery goes along that way you see +that as you discharge the concentration + + align:start position:0% +that as you discharge the concentration + + + align:start position:0% +that as you discharge the concentration +uh at the top of the electrodes is much + + align:start position:0% +uh at the top of the electrodes is much + + + align:start position:0% +uh at the top of the electrodes is much +the acid is used consumed where you're + + align:start position:0% +the acid is used consumed where you're + + + align:start position:0% +the acid is used consumed where you're +drawing current out most readily so + + align:start position:0% +drawing current out most readily so + + + align:start position:0% +drawing current out most readily so +physically the simulation kind of makes + + align:start position:0% +physically the simulation kind of makes + + + align:start position:0% +physically the simulation kind of makes +sense even if my speech didn't um the + + align:start position:0% +sense even if my speech didn't um the + + + align:start position:0% +sense even if my speech didn't um the +battery model that we use is a + + align:start position:0% +battery model that we use is a + + + align:start position:0% +battery model that we use is a +two-dimensional model it has both a lead + + align:start position:0% +two-dimensional model it has both a lead + + + align:start position:0% +two-dimensional model it has both a lead +dioxide electrode and a leg electrode + + align:start position:0% +dioxide electrode and a leg electrode + + + align:start position:0% +dioxide electrode and a leg electrode +and an electrolyte area this is an + + align:start position:0% +and an electrolyte area this is an + + + align:start position:0% +and an electrolyte area this is an +example of just the lead dioxide + + align:start position:0% +example of just the lead dioxide + + + align:start position:0% +example of just the lead dioxide +electrode and if we discretize that in + + align:start position:0% +electrode and if we discretize that in + + + align:start position:0% +electrode and if we discretize that in +two Dimensions we would get uh a + + align:start position:0% +two Dimensions we would get uh a + + + align:start position:0% +two Dimensions we would get uh a +discretization that looks like that if + + align:start position:0% +discretization that looks like that if + + + align:start position:0% +discretization that looks like that if +we were to use a single centered uh + + align:start position:0% +we were to use a single centered uh + + + align:start position:0% +we were to use a single centered uh +finite volume method but it turns out + + align:start position:0% +finite volume method but it turns out + + + align:start position:0% +finite volume method but it turns out +that we have so many discontinuities in + + align:start position:0% +that we have so many discontinuities in + + + align:start position:0% +that we have so many discontinuities in +here that it's much better to use a + + align:start position:0% +here that it's much better to use a + + + align:start position:0% +here that it's much better to use a +staggered grid and so we are using a uh + + align:start position:0% +staggered grid and so we are using a uh + + + align:start position:0% +staggered grid and so we are using a uh +we're using actually two different uh + + align:start position:0% +we're using actually two different uh + + + align:start position:0% +we're using actually two different uh +meshes to simulate the system two + + align:start position:0% +meshes to simulate the system two + + + align:start position:0% +meshes to simulate the system two +different mes well on a single mesh you + + align:start position:0% +different mes well on a single mesh you + + + align:start position:0% +different mes well on a single mesh you +would end up having Four Corners four + + align:start position:0% +would end up having Four Corners four + + + align:start position:0% +would end up having Four Corners four +edges and centers so you'd get uh nine + + align:start position:0% +edges and centers so you'd get uh nine + + + align:start position:0% +edges and centers so you'd get uh nine +different types of objects in one + + align:start position:0% +different types of objects in one + + + align:start position:0% +different types of objects in one +electrode alone and you're talking about + + align:start position:0% +electrode alone and you're talking about + + + align:start position:0% +electrode alone and you're talking about +a rather large and nasty + + align:start position:0% +a rather large and nasty + + + align:start position:0% +a rather large and nasty +simulation on a small scale the + + align:start position:0% +simulation on a small scale the + + + align:start position:0% +simulation on a small scale the +simulation would produce a very sparse + + align:start position:0% +simulation would produce a very sparse + + + align:start position:0% +simulation would produce a very sparse +Matrix that looks something like this + + align:start position:0% +Matrix that looks something like this + + + align:start position:0% +Matrix that looks something like this +and sarian will now come up and talk to + + align:start position:0% +and sarian will now come up and talk to + + + align:start position:0% +and sarian will now come up and talk to +you about the matrices and how solve + + align:start position:0% +you about the matrices and how solve + + + align:start position:0% +you about the matrices and how solve +this + + align:start position:0% + + + + align:start position:0% + +Sy + + align:start position:0% + + + + align:start position:0% + +cont so basically like John said the the + + align:start position:0% +cont so basically like John said the the + + + align:start position:0% +cont so basically like John said the the +problem we essentially trying to + + align:start position:0% +problem we essentially trying to + + + align:start position:0% +problem we essentially trying to +paralyze the most computational + + align:start position:0% +paralyze the most computational + + + align:start position:0% +paralyze the most computational +expensive part of this whole simulation + + align:start position:0% +expensive part of this whole simulation + + + align:start position:0% +expensive part of this whole simulation +is is solving for the Newton at the + + align:start position:0% +is is solving for the Newton at the + + + align:start position:0% +is is solving for the Newton at the +Newton iterations during each load step + + align:start position:0% +Newton iterations during each load step + + + align:start position:0% +Newton iterations during each load step +and and so basically in an abstract I'm + + align:start position:0% +and and so basically in an abstract I'm + + + align:start position:0% +and and so basically in an abstract I'm +sorry any questions + + align:start position:0% +sorry any questions + + + align:start position:0% +sorry any questions +sorry uh I'll try but you you've got to + + align:start position:0% +sorry uh I'll try but you you've got to + + + align:start position:0% +sorry uh I'll try but you you've got to +try and listen harder too TV you have to + + align:start position:0% +try and listen harder too TV you have to + + + align:start position:0% +try and listen harder too TV you have to +yell at that I got it yeah is it is it + + align:start position:0% +yell at that I got it yeah is it is it + + + align:start position:0% +yell at that I got it yeah is it is it +any better now no you got to yell at it + + align:start position:0% +any better now no you got to yell at it + + + align:start position:0% +any better now no you got to yell at it +is it any better now yeah Okay + + align:start position:0% +is it any better now yeah Okay + + + align:start position:0% +is it any better now yeah Okay +cool + + align:start position:0% +cool + + + align:start position:0% +cool +so yeah I I always like to say I'll try + + align:start position:0% +so yeah I I always like to say I'll try + + + align:start position:0% +so yeah I I always like to say I'll try +to speak harder you should try to listen + + align:start position:0% +to speak harder you should try to listen + + + align:start position:0% +to speak harder you should try to listen +harder too so we can meet somewhere meet + + align:start position:0% +harder too so we can meet somewhere meet + + + align:start position:0% +harder too so we can meet somewhere meet +somewh in between uh so basically in in + + align:start position:0% +somewh in between uh so basically in in + + + align:start position:0% +somewh in between uh so basically in in +the abstract sense we trying to solve a + + align:start position:0% +the abstract sense we trying to solve a + + + align:start position:0% +the abstract sense we trying to solve a +system of sparse linear equations and + + align:start position:0% +system of sparse linear equations and + + + align:start position:0% +system of sparse linear equations and +for Simplicity uh for the first pass we + + align:start position:0% +for Simplicity uh for the first pass we + + + align:start position:0% +for Simplicity uh for the first pass we +treated The Matrix as as being done so + + align:start position:0% +treated The Matrix as as being done so + + + align:start position:0% +treated The Matrix as as being done so +we did the whole gaus elimination on + + align:start position:0% +we did the whole gaus elimination on + + + align:start position:0% +we did the whole gaus elimination on +treating assuming the ignoring all the + + align:start position:0% +treating assuming the ignoring all the + + + align:start position:0% +treating assuming the ignoring all the +the zeros of the Matrix um and so the + + align:start position:0% +the zeros of the Matrix um and so the + + + align:start position:0% +the zeros of the Matrix um and so the +basic idea is that you you we do the + + align:start position:0% +basic idea is that you you we do the + + + align:start position:0% +basic idea is that you you we do the +full we we do G elimination with partial + + align:start position:0% +full we we do G elimination with partial + + + align:start position:0% +full we we do G elimination with partial +pting and and it's the forward + + align:start position:0% +pting and and it's the forward + + + align:start position:0% +pting and and it's the forward +elimination stage of the G elimination + + align:start position:0% +elimination stage of the G elimination + + + align:start position:0% +elimination stage of the G elimination +that's that's order and Cube there is + + align:start position:0% +that's that's order and Cube there is + + + align:start position:0% +that's that's order and Cube there is +most expensive and that is the thing + + align:start position:0% +most expensive and that is the thing + + + align:start position:0% +most expensive and that is the thing +that we have tried to paraliz between + + align:start position:0% +that we have tried to paraliz between + + + align:start position:0% +that we have tried to paraliz between +among the spus the partial pting and and + + align:start position:0% +among the spus the partial pting and and + + + align:start position:0% +among the spus the partial pting and and +the par pting and the back s is all done + + align:start position:0% +the par pting and the back s is all done + + + align:start position:0% +the par pting and the back s is all done +on the ppus because that that turned out + + align:start position:0% +on the ppus because that that turned out + + + align:start position:0% +on the ppus because that that turned out +to be much + + align:start position:0% + + + + align:start position:0% + +faster so this is the the the the Matrix + + align:start position:0% +faster so this is the the the the Matrix + + + align:start position:0% +faster so this is the the the the Matrix +that that that we are considering at + + align:start position:0% +that that that we are considering at + + + align:start position:0% +that that that we are considering at +during each step filled with random + + align:start position:0% +during each step filled with random + + + align:start position:0% +during each step filled with random +entries and filled with a random uh + + align:start position:0% +entries and filled with a random uh + + + align:start position:0% +entries and filled with a random uh +right hand side um and and the way GA + + align:start position:0% +right hand side um and and the way GA + + + align:start position:0% +right hand side um and and the way GA +elimination works is that we we start + + align:start position:0% +elimination works is that we we start + + + align:start position:0% +elimination works is that we we start +off with with one of the rows which you + + align:start position:0% +off with with one of the rows which you + + + align:start position:0% +off with with one of the rows which you +call the base row or which is where the + + align:start position:0% +call the base row or which is where the + + + align:start position:0% +call the base row or which is where the +pivots come + + align:start position:0% +pivots come + + + align:start position:0% +pivots come +from and then we we we take all and then + + align:start position:0% +from and then we we we take all and then + + + align:start position:0% +from and then we we we take all and then +we we eliminate the variable + + align:start position:0% +we we eliminate the variable + + + align:start position:0% +we we eliminate the variable +corresponding to base R from all the + + align:start position:0% +corresponding to base R from all the + + + align:start position:0% +corresponding to base R from all the +subsequent uh elimination rows and all + + align:start position:0% +subsequent uh elimination rows and all + + + align:start position:0% +subsequent uh elimination rows and all +these eliminations can be done in parall + + align:start position:0% +these eliminations can be done in parall + + + align:start position:0% +these eliminations can be done in parall +and that's what we have tried to + + align:start position:0% +and that's what we have tried to + + + align:start position:0% +and that's what we have tried to +paralyze so each spu grabs hold grabs + + align:start position:0% +paralyze so each spu grabs hold grabs + + + align:start position:0% +paralyze so each spu grabs hold grabs +hold of the next available elimination + + align:start position:0% +hold of the next available elimination + + + align:start position:0% +hold of the next available elimination +row eliminates it and writes the result + + align:start position:0% +row eliminates it and writes the result + + + align:start position:0% +row eliminates it and writes the result +back on on onto the main memory so for + + align:start position:0% +back on on onto the main memory so for + + + align:start position:0% +back on on onto the main memory so for +example if we consider a situation with + + align:start position:0% +example if we consider a situation with + + + align:start position:0% +example if we consider a situation with +with two uh what we what we do is that + + align:start position:0% +with two uh what we what we do is that + + + align:start position:0% +with two uh what we what we do is that +we stream the rows across the we stram + + align:start position:0% +we stream the rows across the we stram + + + align:start position:0% +we stream the rows across the we stram +the El rows across all the spus each spu + + align:start position:0% +the El rows across all the spus each spu + + + align:start position:0% +the El rows across all the spus each spu +performs the elimination and wres the + + align:start position:0% +performs the elimination and wres the + + + align:start position:0% +performs the elimination and wres the +result back to uh back to main memory as + + align:start position:0% +result back to uh back to main memory as + + + align:start position:0% +result back to uh back to main memory as +you can see and and it it for this + + align:start position:0% +you can see and and it it for this + + + align:start position:0% +you can see and and it it for this +happens for every uhow so once the so in + + align:start position:0% +happens for every uhow so once the so in + + + align:start position:0% +happens for every uhow so once the so in +this simulation the first variable has + + align:start position:0% +this simulation the first variable has + + + align:start position:0% +this simulation the first variable has +been eliminated uh as you can see there + + align:start position:0% +been eliminated uh as you can see there + + + align:start position:0% +been eliminated uh as you can see there +are zeros along the First Column and and + + align:start position:0% +are zeros along the First Column and and + + + align:start position:0% +are zeros along the First Column and and +and and then the process is is recursive + + align:start position:0% +and and then the process is is recursive + + + align:start position:0% +and and then the process is is recursive +after after the first variable is + + align:start position:0% +after after the first variable is + + + align:start position:0% +after after the first variable is +completed it moves on to the next + + align:start position:0% +completed it moves on to the next + + + align:start position:0% +completed it moves on to the next +variable so that's basically how and and + + align:start position:0% +variable so that's basically how and and + + + align:start position:0% +variable so that's basically how and and +as you can and the way the the the + + align:start position:0% +as you can and the way the the the + + + align:start position:0% +as you can and the way the the the +alumination rows are delt out they delt + + align:start position:0% +alumination rows are delt out they delt + + + align:start position:0% +alumination rows are delt out they delt +out in a cyclic fashion so there is no + + align:start position:0% +out in a cyclic fashion so there is no + + + align:start position:0% +out in a cyclic fashion so there is no +serial bottleneck it's all perfectly + + align:start position:0% +serial bottleneck it's all perfectly + + + align:start position:0% +serial bottleneck it's all perfectly +load balanced I'm sorry change you + + align:start position:0% +load balanced I'm sorry change you + + + align:start position:0% +load balanced I'm sorry change you +eliminate something lower does the PIV + + align:start position:0% +eliminate something lower does the PIV + + + align:start position:0% +eliminate something lower does the PIV +value change I'm completely not getting + + align:start position:0% +value change I'm completely not getting + + + align:start position:0% +value change I'm completely not getting +what you are saying that's my first + + align:start position:0% +what you are saying that's my first + + + align:start position:0% +what you are saying that's my first +question yes second question is if is + + align:start position:0% +question yes second question is if is + + + align:start position:0% +question yes second question is if is +fast or dense what's your Matrix + + align:start position:0% +fast or dense what's your Matrix + + + align:start position:0% +fast or dense what's your Matrix +representation The Matrix representation + + align:start position:0% +representation The Matrix representation + + + align:start position:0% +representation The Matrix representation +currently is + + align:start position:0% +currently is + + + align:start position:0% +currently is +dense okay yeah so the Val keep changing + + align:start position:0% +dense okay yeah so the Val keep changing + + + align:start position:0% +dense okay yeah so the Val keep changing +when you eliminate so if it completely + + align:start position:0% +when you eliminate so if it completely + + + align:start position:0% +when you eliminate so if it completely +parall and that's what the so are theend + + align:start position:0% +parall and that's what the so are theend + + + align:start position:0% +parall and that's what the so are theend +so so the elimination so the all the + + align:start position:0% +so so the elimination so the all the + + + align:start position:0% +so so the elimination so the all the +subsequent variables that that are + + align:start position:0% +subsequent variables that that are + + + align:start position:0% +subsequent variables that that are +eliminated during for for each variable + + align:start position:0% +eliminated during for for each variable + + + align:start position:0% +eliminated during for for each variable +r r can be done in parall but after + + align:start position:0% +r r can be done in parall but after + + + align:start position:0% +r r can be done in parall but after +after one variable has been eliminated + + align:start position:0% +after one variable has been eliminated + + + align:start position:0% +after one variable has been eliminated +there's a synchronization step where all + + align:start position:0% +there's a synchronization step where all + + + align:start position:0% +there's a synchronization step where all +the spus have to have to synchronize + + align:start position:0% +the spus have to have to synchronize + + + align:start position:0% +the spus have to have to synchronize +there's a barrier after each after each + + align:start position:0% +there's a barrier after each after each + + + align:start position:0% +there's a barrier after each after each +row has been + + align:start position:0% +row has been + + + align:start position:0% +row has been +eliminated okay okay yeah so so so you + + align:start position:0% +eliminated okay okay yeah so so so you + + + align:start position:0% +eliminated okay okay yeah so so so you +started so so there's a triply nested + + align:start position:0% +started so so there's a triply nested + + + align:start position:0% +started so so there's a triply nested +for Loop if you write the algorithm down + + align:start position:0% +for Loop if you write the algorithm down + + + align:start position:0% +for Loop if you write the algorithm down +and you and the first and and then it's + + align:start position:0% +and you and the first and and then it's + + + align:start position:0% +and you and the first and and then it's +the it's it's the inner two Loops that + + align:start position:0% +the it's it's the inner two Loops that + + + align:start position:0% +the it's it's the inner two Loops that +are completely paralyzable and that's + + align:start position:0% +are completely paralyzable and that's + + + align:start position:0% +are completely paralyzable and that's +the second Loop is what you try to + + align:start position:0% +the second Loop is what you try to + + + align:start position:0% +the second Loop is what you try to +paralyze okay is that a little clearer + + align:start position:0% +paralyze okay is that a little clearer + + + align:start position:0% +paralyze okay is that a little clearer +yeah so U this is the this is the basic + + align:start position:0% +yeah so U this is the this is the basic + + + align:start position:0% +yeah so U this is the this is the basic +algorithm and and uh um let John talk + + align:start position:0% +algorithm and and uh um let John talk + + + align:start position:0% +algorithm and and uh um let John talk +about some of the performance numbers uh + + align:start position:0% +about some of the performance numbers uh + + + align:start position:0% +about some of the performance numbers uh +we have got but but uh some of the + + align:start position:0% +we have got but but uh some of the + + + align:start position:0% +we have got but but uh some of the +optimizations that we have tried to that + + align:start position:0% +optimizations that we have tried to that + + + align:start position:0% +optimizations that we have tried to that +we haven't done are are are the use of + + align:start position:0% +we haven't done are are are the use of + + + align:start position:0% +we haven't done are are are the use of +BL three operations where you stream + + align:start position:0% +BL three operations where you stream + + + align:start position:0% +BL three operations where you stream +multiple draws at a time and and uh + + align:start position:0% +multiple draws at a time and and uh + + + align:start position:0% +multiple draws at a time and and uh +use of C operations but I'll let jump + + align:start position:0% + + + + align:start position:0% + +the um computation of the current + + align:start position:0% +the um computation of the current + + + align:start position:0% +the um computation of the current +elimination row with the fetching of the + + align:start position:0% +elimination row with the fetching of the + + + align:start position:0% +elimination row with the fetching of the +next elimination row um we get roughly a + + align:start position:0% +next elimination row um we get roughly a + + + align:start position:0% +next elimination row um we get roughly a +30% speed up so here's a graph of um uh + + align:start position:0% +30% speed up so here's a graph of um uh + + + align:start position:0% +30% speed up so here's a graph of um uh +to see how both the unbuffered and + + align:start position:0% +to see how both the unbuffered and + + + align:start position:0% +to see how both the unbuffered and +buffer version um performed um with a + + align:start position:0% +buffer version um performed um with a + + + align:start position:0% +buffer version um performed um with a +number of scaling with a number of spus + + align:start position:0% +number of scaling with a number of spus + + + align:start position:0% +number of scaling with a number of spus +so as you can see both look roughly + + align:start position:0% +so as you can see both look roughly + + + align:start position:0% +so as you can see both look roughly +pretty linear um and um that makes sense + + align:start position:0% +pretty linear um and um that makes sense + + + align:start position:0% +pretty linear um and um that makes sense +because uh + + align:start position:0% +because uh + + + align:start position:0% +because uh +the and + + align:start position:0% + + + + align:start position:0% + +so so here's here's another graph of um + + align:start position:0% +so so here's here's another graph of um + + + align:start position:0% +so so here's here's another graph of um +how um we how we scale with the size of + + align:start position:0% +how um we how we scale with the size of + + + align:start position:0% +how um we how we scale with the size of +the Matrix that we're working with so + + align:start position:0% +the Matrix that we're working with so + + + align:start position:0% +the Matrix that we're working with so +the smaller the Matrix the higher the + + align:start position:0% +the smaller the Matrix the higher the + + + align:start position:0% +the smaller the Matrix the higher the +communication computation ratio so the + + align:start position:0% +communication computation ratio so the + + + align:start position:0% +communication computation ratio so the +the communication latency should be more + + align:start position:0% +the communication latency should be more + + + align:start position:0% +the communication latency should be more +apparent but as you can see + + align:start position:0% +apparent but as you can see + + + align:start position:0% +apparent but as you can see +um even even as you get smaller um + + align:start position:0% +um even even as you get smaller um + + + align:start position:0% +um even even as you get smaller um +the the computation is still pretty + + align:start position:0% +the the computation is still pretty + + + align:start position:0% +the the computation is still pretty +linear um so yeah it's linear but it's + + align:start position:0% +linear um so yeah it's linear but it's + + + align:start position:0% +linear um so yeah it's linear but it's +not as + + align:start position:0% + + + + align:start position:0% + +B it which not running at two + + align:start position:0% +B it which not running at two + + + align:start position:0% +B it which not running at two +performance Improvement but it has a + + align:start position:0% +performance Improvement but it has a + + + align:start position:0% +performance Improvement but it has a +very it's not fling out so the + + align:start position:0% +very it's not fling out so the + + + align:start position:0% +very it's not fling out so the +interesting thing is why is it only 30% + + align:start position:0% +interesting thing is why is it only 30% + + + align:start position:0% +interesting thing is why is it only 30% +why is it not 2x get 2x performance + + align:start position:0% +why is it not 2x get 2x performance + + + align:start position:0% +why is it not 2x get 2x performance +Improvement so is it because of underlow + + align:start position:0% +Improvement so is it because of underlow + + + align:start position:0% +Improvement so is it because of underlow +if it is underlow this graph shouldn't + + align:start position:0% +if it is underlow this graph shouldn't + + + align:start position:0% +if it is underlow this graph shouldn't +have this kind of a pattern it should + + align:start position:0% +have this kind of a pattern it should + + + align:start position:0% +have this kind of a pattern it should +kind of have a more exponential type + + align:start position:0% + + + + align:start position:0% + +pattern no why so why aren't you getting + + align:start position:0% +pattern no why so why aren't you getting + + + align:start position:0% +pattern no why so why aren't you getting +2x speed up or I mean your your line is + + align:start position:0% +2x speed up or I mean your your line is + + + align:start position:0% +2x speed up or I mean your your line is +straight yeah but it's not increasing + + align:start position:0% +straight yeah but it's not increasing + + + align:start position:0% +straight yeah but it's not increasing +proportional to the number of spus + + align:start position:0% +proportional to the number of spus + + + align:start position:0% +proportional to the number of spus +you're increasing so your efficiency + + align:start position:0% +you're increasing so your efficiency + + + align:start position:0% +you're increasing so your efficiency +might not be at 100% any idea + + align:start position:0% + + + + align:start position:0% + +why the two the 2x would only this is a + + align:start position:0% +why the two the 2x would only this is a + + + align:start position:0% +why the two the 2x would only this is a +l Lo so two would only shift it up and + + align:start position:0% +l Lo so two would only shift it up and + + + align:start position:0% +l Lo so two would only shift it up and +down yeah so so looks like you're not + + align:start position:0% +down yeah so so looks like you're not + + + align:start position:0% +down yeah so so looks like you're not +operating at 100% efficiency right oh + + align:start position:0% +operating at 100% efficiency right oh + + + align:start position:0% +operating at 100% efficiency right oh +definely not yeah so I think + + align:start position:0% +definely not yeah so I think + + + align:start position:0% +definely not yeah so I think +the conversation going on there but this + + align:start position:0% +the conversation going on there but this + + + align:start position:0% +the conversation going on there but this +is a stretch type of a gra because + + align:start position:0% +is a stretch type of a gra because + + + align:start position:0% +is a stretch type of a gra because +if it goes actually to do kind of + + align:start position:0% +if it goes actually to do kind of + + + align:start position:0% +if it goes actually to do kind of +improvement and and you get a very nice + + align:start position:0% +improvement and and you get a very nice + + + align:start position:0% +improvement and and you get a very nice +linear T if you have under typ forhead + + align:start position:0% +linear T if you have under typ forhead + + + align:start position:0% +linear T if you have under typ forhead +what you get is you have a good speed up + + align:start position:0% +what you get is you have a good speed up + + + align:start position:0% +what you get is you have a good speed up +at the beginning and then you slow down + + align:start position:0% +at the beginning and then you slow down + + + align:start position:0% +at the beginning and then you slow down +you get a kind of logarithmic type of + + align:start position:0% +you get a kind of logarithmic type of + + + align:start position:0% +you get a kind of logarithmic type of +GRA so it's very I haven't seen things + + align:start position:0% +GRA so it's very I haven't seen things + + + align:start position:0% +GRA so it's very I haven't seen things +like a straight line but not at 45° + + align:start position:0% +like a straight line but not at 45° + + + align:start position:0% +like a straight line but not at 45° +angle Gra is kind of a Str thing it + + align:start position:0% +angle Gra is kind of a Str thing it + + + align:start position:0% +angle Gra is kind of a Str thing it +might be to see where and why this is + + align:start position:0% +might be to see where and why this is + + + align:start position:0% +might be to see where and why this is +happening okay um well yeah so I'll just + + align:start position:0% +happening okay um well yeah so I'll just + + + align:start position:0% +happening okay um well yeah so I'll just +move on um so I'll talk about some of + + align:start position:0% +move on um so I'll talk about some of + + + align:start position:0% +move on um so I'll talk about some of +the further work we're trying to do um + + align:start position:0% +the further work we're trying to do um + + + align:start position:0% +the further work we're trying to do um +you + + align:start position:0% + + + + align:start position:0% + +just + + align:start position:0% +just + + + align:start position:0% +just +yeah so um we've also tried to Triple + + align:start position:0% +yeah so um we've also tried to Triple + + + align:start position:0% +yeah so um we've also tried to Triple +buffer by um uh pipelining the fetching + + align:start position:0% +buffer by um uh pipelining the fetching + + + align:start position:0% +buffer by um uh pipelining the fetching +of the U of the next row with the + + align:start position:0% +of the U of the next row with the + + + align:start position:0% +of the U of the next row with the +computation of the current row row with + + align:start position:0% +computation of the current row row with + + + align:start position:0% +computation of the current row row with +the um sending of the previous row um we + + align:start position:0% +the um sending of the previous row um we + + + align:start position:0% +the um sending of the previous row um we +did this but it didn't actually give us + + align:start position:0% +did this but it didn't actually give us + + + align:start position:0% +did this but it didn't actually give us +the speed up that um we we thought we + + align:start position:0% +the speed up that um we we thought we + + + align:start position:0% +the speed up that um we we thought we +would get um what we're working on now + + align:start position:0% +would get um what we're working on now + + + align:start position:0% +would get um what we're working on now +is smizing the computation stage so + + align:start position:0% +is smizing the computation stage so + + + align:start position:0% +is smizing the computation stage so +right now we treat the the rows as all + + align:start position:0% +right now we treat the the rows as all + + + align:start position:0% +right now we treat the the rows as all +the doubles and the rows as scalers but + + align:start position:0% +the doubles and the rows as scalers but + + + align:start position:0% +the doubles and the rows as scalers but +we could use the my sying hopefully we + + align:start position:0% +we could use the my sying hopefully we + + + align:start position:0% +we could use the my sying hopefully we +can get a speed up of um by a factor of + + align:start position:0% +can get a speed up of um by a factor of + + + align:start position:0% +can get a speed up of um by a factor of +two um and also right now our Lu + + align:start position:0% +two um and also right now our Lu + + + align:start position:0% +two um and also right now our Lu +algorithm isn't + + align:start position:0% +algorithm isn't + + + align:start position:0% +algorithm isn't +very smart in that when we fetch the + + align:start position:0% +very smart in that when we fetch the + + + align:start position:0% +very smart in that when we fetch the +elimination row as we go on through the + + align:start position:0% +elimination row as we go on through the + + + align:start position:0% +elimination row as we go on through the +algorithm part of the elimination row + + align:start position:0% +algorithm part of the elimination row + + + align:start position:0% +algorithm part of the elimination row +becomes zeros as we move down so um we + + align:start position:0% +becomes zeros as we move down so um we + + + align:start position:0% +becomes zeros as we move down so um we +don't really need to fetch the entire + + align:start position:0% +don't really need to fetch the entire + + + align:start position:0% +don't really need to fetch the entire +elimination row and so by taking that + + align:start position:0% +elimination row and so by taking that + + + align:start position:0% +elimination row and so by taking that +into account um our memory the transfer + + align:start position:0% +into account um our memory the transfer + + + align:start position:0% +into account um our memory the transfer +our dma transfers are smaller and maybe + + align:start position:0% +our dma transfers are smaller and maybe + + + align:start position:0% +our dma transfers are smaller and maybe +that'll speed things up a + + align:start position:0% +that'll speed things up a + + + align:start position:0% +that'll speed things up a +bit so the whole thing is in double + + align:start position:0% +bit so the whole thing is in double + + + align:start position:0% +bit so the whole thing is in double +Precision yes + + align:start position:0% +Precision yes + + + align:start position:0% +Precision yes +it's you know how many flop we have G + + align:start position:0% +it's you know how many flop we have G + + + align:start position:0% +it's you know how many flop we have G +flops I think we around G flops so + + align:start position:0% +flops I think we around G flops so + + + align:start position:0% +flops I think we around G flops so +here's a g + + align:start position:0% + + + + align:start position:0% + +flops you know what the + + align:start position:0% + + + + align:start position:0% + +expected is this a linear scale or on + + align:start position:0% +expected is this a linear scale or on + + + align:start position:0% +expected is this a linear scale or on +the Y + + align:start position:0% + + + + align:start position:0% + +AIS idea why you have thisa 3S to use + + align:start position:0% +AIS idea why you have thisa 3S to use + + + align:start position:0% +AIS idea why you have thisa 3S to use +your double buffing result just + + align:start position:0% + + + + align:start position:0% + +drops actually + + align:start position:0% +drops actually + + + align:start position:0% +drops actually +idea I don't + + align:start position:0% + + + + align:start position:0% + +know you might want to run a few more + + align:start position:0% +know you might want to run a few more + + + align:start position:0% +know you might want to run a few more +times um there is uh a recent series of + + align:start position:0% +times um there is uh a recent series of + + + align:start position:0% +times um there is uh a recent series of +papers by Jack gar were aiming at Double + + align:start position:0% +papers by Jack gar were aiming at Double + + + align:start position:0% +papers by Jack gar were aiming at Double +Precision calculations they did used + + align:start position:0% +Precision calculations they did used + + + align:start position:0% +Precision calculations they did used +single Precision to get an approximate + + align:start position:0% +single Precision to get an approximate + + + align:start position:0% +single Precision to get an approximate +guess and then did a few iterations of + + align:start position:0% +guess and then did a few iterations of + + + align:start position:0% +guess and then did a few iterations of +an iterative approach to get a double + + align:start position:0% +an iterative approach to get a double + + + align:start position:0% +an iterative approach to get a double +Precision result yeah those don't work + + align:start position:0% +Precision result yeah those don't work + + + align:start position:0% +Precision result yeah those don't work +very well for poly conditioned mates + + align:start position:0% +very well for poly conditioned mates + + + align:start position:0% +very well for poly conditioned mates +what theying and this is conditioned + + align:start position:0% +what theying and this is conditioned + + + align:start position:0% +what theying and this is conditioned +around 10 to the8 so that's kind of out + + align:start position:0% +around 10 to the8 so that's kind of out + + + align:start position:0% +around 10 to the8 so that's kind of out +of the part + + align:start position:0% + + + + align:start position:0% + +of they do they try to + + align:start position:0% +of they do they try to + + + align:start position:0% +of they do they try to +doal the main reason they do is because + + align:start position:0% + + + + align:start position:0% + +we doing things the hope is to + + align:start position:0% +we doing things the hope is to + + + align:start position:0% +we doing things the hope is to +generalize this to to spar metries later + + align:start position:0% +generalize this to to spar metries later + + + align:start position:0% +generalize this to to spar metries later +on and and I don't think I think they + + align:start position:0% +on and and I don't think I think they + + + align:start position:0% +on and and I don't think I think they +are doing trying to do some work with + + align:start position:0% +are doing trying to do some work with + + + align:start position:0% +are doing trying to do some work with +with spars metries but they haven't + + align:start position:0% +with spars metries but they haven't + + + align:start position:0% +with spars metries but they haven't +gotten + + align:start position:0% + + + + align:start position:0% + +that one additional question just at at + + align:start position:0% +that one additional question just at at + + + align:start position:0% +that one additional question just at at +a high level is this the right way to + + align:start position:0% +a high level is this the right way to + + + align:start position:0% +a high level is this the right way to +tackle this particular problem it's + + align:start position:0% +tackle this particular problem it's + + + align:start position:0% +tackle this particular problem it's +strikes me that there must be a closed + + align:start position:0% +strikes me that there must be a closed + + + align:start position:0% +strikes me that there must be a closed +form uh you know high level macroscopic + + align:start position:0% +form uh you know high level macroscopic + + + align:start position:0% +form uh you know high level macroscopic +model for you + + align:start position:0% +model for you + + + align:start position:0% +model for you +know battery self- + + align:start position:0% +know battery self- + + + align:start position:0% +know battery self- +discharge I don't know anything about + + align:start position:0% +discharge I don't know anything about + + + align:start position:0% +discharge I don't know anything about +the chemistry of lead acid batteries but + + align:start position:0% +the chemistry of lead acid batteries but + + + align:start position:0% +the chemistry of lead acid batteries but +your your the right up on the website + + align:start position:0% +your your the right up on the website + + + align:start position:0% +your your the right up on the website +mentions black shols which I do know + + align:start position:0% +mentions black shols which I do know + + + align:start position:0% +mentions black shols which I do know +something about and of course there are + + align:start position:0% +something about and of course there are + + + align:start position:0% +something about and of course there are +efficient ways of doing that without + + align:start position:0% +efficient ways of doing that without + + + align:start position:0% +efficient ways of doing that without +sure there there are efficient ways of + + align:start position:0% +sure there there are efficient ways of + + + align:start position:0% +sure there there are efficient ways of +doing blacks there are different ways of + + align:start position:0% +doing blacks there are different ways of + + + align:start position:0% +doing blacks there are different ways of +doing this this is only one of the + + align:start position:0% +doing this this is only one of the + + + align:start position:0% +doing this this is only one of the +equations is similar to Black there are + + align:start position:0% +equations is similar to Black there are + + + align:start position:0% +equations is similar to Black there are +multiple equations that go into this + + align:start position:0% +multiple equations that go into this + + + align:start position:0% +multiple equations that go into this +they're all coupl nonlinear so solving + + align:start position:0% +they're all coupl nonlinear so solving + + + align:start position:0% +they're all coupl nonlinear so solving +this system of equations is in the + + align:start position:0% +this system of equations is in the + + + align:start position:0% +this system of equations is in the +literature if you were going to if you + + align:start position:0% +literature if you were going to if you + + + align:start position:0% +literature if you were going to if you +were going to choose this as your model + + align:start position:0% +were going to choose this as your model + + + align:start position:0% +were going to choose this as your model +but if if you are actually in the + + align:start position:0% +but if if you are actually in the + + + align:start position:0% +but if if you are actually in the +business of of you know well building + + align:start position:0% +business of of you know well building + + + align:start position:0% +business of of you know well building +building and Anda the wouldn't you try + + align:start position:0% +building and Anda the wouldn't you try + + + align:start position:0% +building and Anda the wouldn't you try +and come up with a an efficient + + align:start position:0% +and come up with a an efficient + + + align:start position:0% +and come up with a an efficient +macroscopic model rather than you well + + align:start position:0% +macroscopic model rather than you well + + + align:start position:0% +macroscopic model rather than you well +it depends on what your compute costs + + align:start position:0% +it depends on what your compute costs + + + align:start position:0% +it depends on what your compute costs +are I mean if you know if you going to + + align:start position:0% +are I mean if you know if you going to + + + align:start position:0% +are I mean if you know if you going to +run a model on a supercal processor + + align:start position:0% +run a model on a supercal processor + + + align:start position:0% +run a model on a supercal processor +that's a very expensive processor if + + align:start position:0% +that's a very expensive processor if + + + align:start position:0% +that's a very expensive processor if +however now you have the ability to use + + align:start position:0% +however now you have the ability to use + + + align:start position:0% +however now you have the ability to use +a collection of small cheap you know + + align:start position:0% +a collection of small cheap you know + + + align:start position:0% +a collection of small cheap you know +little processors like this you can + + align:start position:0% +little processors like this you can + + + align:start position:0% +little processors like this you can +maybe have the luxury of using a much + + align:start position:0% +maybe have the luxury of using a much + + + align:start position:0% +maybe have the luxury of using a much +more sophisticated model so is it + + align:start position:0% +more sophisticated model so is it + + + align:start position:0% +more sophisticated model so is it +necessarily more sophisticated I mean is + + align:start position:0% +necessarily more sophisticated I mean is + + + align:start position:0% +necessarily more sophisticated I mean is +there some fundamental reason why you + + align:start position:0% +there some fundamental reason why you + + + align:start position:0% +there some fundamental reason why you +get more information out of this + + align:start position:0% +get more information out of this + + + align:start position:0% +get more information out of this +approach + + align:start position:0% +approach + + + align:start position:0% +approach +than out of a higher level model uh you + + align:start position:0% +than out of a higher level model uh you + + + align:start position:0% +than out of a higher level model uh you +you get a lot more detail as to what's + + align:start position:0% +you get a lot more detail as to what's + + + align:start position:0% +you get a lot more detail as to what's +going on within your battery a high + + align:start position:0% +going on within your battery a high + + + align:start position:0% +going on within your battery a high +level model will give you IO information + + align:start position:0% +level model will give you IO information + + + align:start position:0% +level model will give you IO information +but if you're trying to find failure + + align:start position:0% +but if you're trying to find failure + + + align:start position:0% +but if you're trying to find failure +mechanisms you may want to know how much + + align:start position:0% +mechanisms you may want to know how much + + + align:start position:0% +mechanisms you may want to know how much +pressure is going on at certain points + + align:start position:0% +pressure is going on at certain points + + + align:start position:0% +pressure is going on at certain points +in your battery especially with like + + align:start position:0% +in your battery especially with like + + + align:start position:0% +in your battery especially with like +lithium ion batteries when you inter + + align:start position:0% +lithium ion batteries when you inter + + + align:start position:0% +lithium ion batteries when you inter +this is this differs from a lithium ion + + align:start position:0% +this is this differs from a lithium ion + + + align:start position:0% +this is this differs from a lithium ion +battery in that that we're actually + + align:start position:0% +battery in that that we're actually + + + align:start position:0% +battery in that that we're actually +changing the state the type of matter + + align:start position:0% +changing the state the type of matter + + + align:start position:0% +changing the state the type of matter +that we're using and in lithium ion + + align:start position:0% +that we're using and in lithium ion + + + align:start position:0% +that we're using and in lithium ion +battery we're interpolating and de + + align:start position:0% +battery we're interpolating and de + + + align:start position:0% +battery we're interpolating and de +interpolating and so what we're doing is + + align:start position:0% +interpolating and so what we're doing is + + + align:start position:0% +interpolating and so what we're doing is +we're creating a lot of stress on a + + align:start position:0% +we're creating a lot of stress on a + + + align:start position:0% +we're creating a lot of stress on a +matrix a crystal and that will be a + + align:start position:0% +matrix a crystal and that will be a + + + align:start position:0% +matrix a crystal and that will be a +failure mechanism a simple uh input + + align:start position:0% +failure mechanism a simple uh input + + + align:start position:0% +failure mechanism a simple uh input +output relationship will not give you + + align:start position:0% +output relationship will not give you + + + align:start position:0% +output relationship will not give you +that failure mechanism so you may want + + align:start position:0% +that failure mechanism so you may want + + + align:start position:0% +that failure mechanism so you may want +to know that kind of information you may + + align:start position:0% +to know that kind of information you may + + + align:start position:0% +to know that kind of information you may +want to know heat information also you + + align:start position:0% +want to know heat information also you + + + align:start position:0% +want to know heat information also you +could include you know thermodynamical + + align:start position:0% +could include you know thermodynamical + + + align:start position:0% +could include you know thermodynamical +information into this kind of model okay + + align:start position:0% +information into this kind of model okay + + + align:start position:0% +information into this kind of model okay +that's a good answer I I I take that uh + + align:start position:0% +that's a good answer I I I take that uh + + + align:start position:0% +that's a good answer I I I take that uh +to mean that the the reason for doing + + align:start position:0% +to mean that the the reason for doing + + + align:start position:0% +to mean that the the reason for doing +this is if you're researching the you + + align:start position:0% +this is if you're researching the you + + + align:start position:0% +this is if you're researching the you +know physics of of battery discharge as + + align:start position:0% +know physics of of battery discharge as + + + align:start position:0% +know physics of of battery discharge as +opposed to you know trying to estimate + + align:start position:0% +opposed to you know trying to estimate + + + align:start position:0% +opposed to you know trying to estimate +you know how much uh Power is left in + + align:start position:0% +you know how much uh Power is left in + + + align:start position:0% +you know how much uh Power is left in +your battery well you could you could + + align:start position:0% +your battery well you could you could + + + align:start position:0% +your battery well you could you could +use it if you have the computation power + + align:start position:0% +use it if you have the computation power + + + align:start position:0% +use it if you have the computation power +you could use the same model that does + + align:start position:0% +you could use the same model that does + + + align:start position:0% +you could use the same model that does +the research as the car and so if you + + align:start position:0% +the research as the car and so if you + + + align:start position:0% +the research as the car and so if you +yeah if you can use small processor so + + align:start position:0% +yeah if you can use small processor so + + + align:start position:0% +yeah if you can use small processor so +our demonstration if you guys want to + + align:start position:0% +our demonstration if you guys want to + + + align:start position:0% +our demonstration if you guys want to +see printf statements + + align:start position:0% +see printf statements + + + align:start position:0% +see printf statements +um yeah any last questions wait just so + + align:start position:0% +um yeah any last questions wait just so + + + align:start position:0% +um yeah any last questions wait just so +try understand the sparse versus Den + + align:start position:0% +try understand the sparse versus Den + + + align:start position:0% +try understand the sparse versus Den +issue just do a sparse elimination on a + + align:start position:0% +issue just do a sparse elimination on a + + + align:start position:0% +issue just do a sparse elimination on a +on a unior you get a bigger speed up oh + + align:start position:0% +on a unior you get a bigger speed up oh + + + align:start position:0% +on a unior you get a bigger speed up oh +you get a much bigger speed up okay you + + align:start position:0% +you get a much bigger speed up okay you + + + align:start position:0% +you get a much bigger speed up okay you +know the sparse is the Lu is about the + + align:start position:0% +know the sparse is the Lu is about the + + + align:start position:0% +know the sparse is the Lu is about the +slowest thing you could possibly choose + + align:start position:0% +slowest thing you could possibly choose + + + align:start position:0% +slowest thing you could possibly choose +but it works but what you have would + + align:start position:0% +but it works but what you have would + + + align:start position:0% +but it works but what you have would +still be useful for dense matrices it + + align:start position:0% +still be useful for dense matrices it + + + align:start position:0% +still be useful for dense matrices it +would still be useful for dense matrices + + align:start position:0% +would still be useful for dense matrices + + + align:start position:0% +would still be useful for dense matrices +and did you compare it all to just PPU + + align:start position:0% +and did you compare it all to just PPU + + + align:start position:0% +and did you compare it all to just PPU +performance on a dense Matrix uh no we + + align:start position:0% +performance on a dense Matrix uh no we + + + align:start position:0% +performance on a dense Matrix uh no we +didn't compare it to the PPU we we had a + + align:start position:0% +didn't compare it to the PPU we we had a + + + align:start position:0% +didn't compare it to the PPU we we had a +compare we have the same model running + + align:start position:0% +compare we have the same model running + + + align:start position:0% +compare we have the same model running +on a uh + + align:start position:0% +on a uh + + + align:start position:0% +on a uh +PC okay thanks speakers + + align:start position:0% +PC okay thanks speakers + + + align:start position:0% +PC okay thanks speakers +[Applause] \ No newline at end of file diff --git a/j5XdY5wkVTA.txt b/j5XdY5wkVTA.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa9482ce11775fde9fd21d21b35fb0c017e9ab84 --- /dev/null +++ b/j5XdY5wkVTA.txt @@ -0,0 +1,15195 @@ +align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +welcome everyone this is 1413 psychology + + align:start position:0% +welcome everyone this is 1413 psychology + + + align:start position:0% +welcome everyone this is 1413 psychology +and economics also known as behavioral + + align:start position:0% +and economics also known as behavioral + + + align:start position:0% +and economics also known as behavioral +economics + + align:start position:0% +economics + + + align:start position:0% +economics +my name is frank schilbach i'm a faculty + + align:start position:0% +my name is frank schilbach i'm a faculty + + + align:start position:0% +my name is frank schilbach i'm a faculty +member in the economics department + + align:start position:0% +member in the economics department + + + align:start position:0% +member in the economics department +teaching and doing research in + + align:start position:0% +teaching and doing research in + + + align:start position:0% +teaching and doing research in +behavioral economics and + + align:start position:0% +behavioral economics and + + + align:start position:0% +behavioral economics and +psychology and economics and development + + align:start position:0% +psychology and economics and development + + + align:start position:0% +psychology and economics and development +economics + + align:start position:0% +economics + + + align:start position:0% +economics +there's syllabi over here in case + + align:start position:0% +there's syllabi over here in case + + + align:start position:0% +there's syllabi over here in case +anybody uh uh needs one + + align:start position:0% +anybody uh uh needs one + + + align:start position:0% +anybody uh uh needs one +so let me sort of start with introducing + + align:start position:0% +so let me sort of start with introducing + + + align:start position:0% +so let me sort of start with introducing +ourselves uh including myself + + align:start position:0% +ourselves uh including myself + + + align:start position:0% +ourselves uh including myself +as i said i'm uh frank schilbach i'm an + + align:start position:0% +as i said i'm uh frank schilbach i'm an + + + align:start position:0% +as i said i'm uh frank schilbach i'm an +economics + + align:start position:0% +economics + + + align:start position:0% +economics +phd i'm from harvard recently um i'm + + align:start position:0% +phd i'm from harvard recently um i'm + + + align:start position:0% +phd i'm from harvard recently um i'm +from + + align:start position:0% +from + + + align:start position:0% +from +germany in case uh as you may have + + align:start position:0% +germany in case uh as you may have + + + align:start position:0% +germany in case uh as you may have +noticed i do research at the + + align:start position:0% +noticed i do research at the + + + align:start position:0% +noticed i do research at the +intersection of development behavioral + + align:start position:0% +intersection of development behavioral + + + align:start position:0% +intersection of development behavioral +economics in particular i'm interested + + align:start position:0% +economics in particular i'm interested + + + align:start position:0% +economics in particular i'm interested +in + + align:start position:0% +in + + + align:start position:0% +in +integrating uh psychological issues and + + align:start position:0% +integrating uh psychological issues and + + + align:start position:0% +integrating uh psychological issues and +uh helping us understand better + + align:start position:0% +uh helping us understand better + + + align:start position:0% +uh helping us understand better +um uh the lives of the poor and so they + + align:start position:0% +um uh the lives of the poor and so they + + + align:start position:0% +um uh the lives of the poor and so they +study all sorts of issues related to + + align:start position:0% +study all sorts of issues related to + + + align:start position:0% +study all sorts of issues related to +poverty + + align:start position:0% +poverty + + + align:start position:0% +poverty +how poverty itself affects people's + + align:start position:0% +how poverty itself affects people's + + + align:start position:0% +how poverty itself affects people's +behavior um + + align:start position:0% +behavior um + + + align:start position:0% +behavior um +and how conditions of poverty or things + + align:start position:0% +and how conditions of poverty or things + + + align:start position:0% +and how conditions of poverty or things +that are associated with poverty might + + align:start position:0% +that are associated with poverty might + + + align:start position:0% +that are associated with poverty might +feed back into people's decision making + + align:start position:0% +feed back into people's decision making + + + align:start position:0% +feed back into people's decision making +and their productivity or labor market + + align:start position:0% +and their productivity or labor market + + + align:start position:0% +and their productivity or labor market +behaviors + + align:start position:0% +behaviors + + + align:start position:0% +behaviors +and then perhaps sort of lead to the + + align:start position:0% +and then perhaps sort of lead to the + + + align:start position:0% +and then perhaps sort of lead to the +persistence of poverty through those + + align:start position:0% +persistence of poverty through those + + + align:start position:0% +persistence of poverty through those +kinds of effects + + align:start position:0% +kinds of effects + + + align:start position:0% +kinds of effects +so i have some work on financial + + align:start position:0% +so i have some work on financial + + + align:start position:0% +so i have some work on financial +constraints how financial constraints + + align:start position:0% +constraints how financial constraints + + + align:start position:0% +constraints how financial constraints +affect people's behavior + + align:start position:0% +affect people's behavior + + + align:start position:0% +affect people's behavior +in terms of thinking about money itself + + align:start position:0% +in terms of thinking about money itself + + + align:start position:0% +in terms of thinking about money itself +i have some work on sleep deprivation + + align:start position:0% +i have some work on sleep deprivation + + + align:start position:0% +i have some work on sleep deprivation +among the urban poor + + align:start position:0% +among the urban poor + + + align:start position:0% +among the urban poor +i'm thinking about pain and substance + + align:start position:0% +i'm thinking about pain and substance + + + align:start position:0% +i'm thinking about pain and substance +abuse and how that might affect people's + + align:start position:0% +abuse and how that might affect people's + + + align:start position:0% +abuse and how that might affect people's +choices + + align:start position:0% +choices + + + align:start position:0% +choices +uh uh most recently i'm interested in + + align:start position:0% +uh uh most recently i'm interested in + + + align:start position:0% +uh uh most recently i'm interested in +uh things related to mental health in + + align:start position:0% +uh things related to mental health in + + + align:start position:0% +uh things related to mental health in +particular depression and loneliness + + align:start position:0% +particular depression and loneliness + + + align:start position:0% +particular depression and loneliness +how those might affect people's + + align:start position:0% +how those might affect people's + + + align:start position:0% +how those might affect people's +well-being and then their um behaviors + + align:start position:0% +well-being and then their um behaviors + + + align:start position:0% +well-being and then their um behaviors +um i have um office hours um + + align:start position:0% +um i have um office hours um + + + align:start position:0% +um i have um office hours um +where you can sign up on my website uh + + align:start position:0% +where you can sign up on my website uh + + + align:start position:0% +where you can sign up on my website uh +currently they're on tuesday afternoons + + align:start position:0% +currently they're on tuesday afternoons + + + align:start position:0% +currently they're on tuesday afternoons +but you know if you cannot find + + align:start position:0% +but you know if you cannot find + + + align:start position:0% +but you know if you cannot find +times that work for you please email me + + align:start position:0% +times that work for you please email me + + + align:start position:0% +times that work for you please email me +and you'll find some time that that + + align:start position:0% +and you'll find some time that that + + + align:start position:0% +and you'll find some time that that +works out + + align:start position:0% +works out + + + align:start position:0% +works out +my assistant is krista moody in case you + + align:start position:0% +my assistant is krista moody in case you + + + align:start position:0% +my assistant is krista moody in case you +want to sort of get a hold of me and and + + align:start position:0% +want to sort of get a hold of me and and + + + align:start position:0% +want to sort of get a hold of me and and +i + + align:start position:0% +i + + + align:start position:0% +i +um i'm not available for some reason you + + align:start position:0% +um i'm not available for some reason you + + + align:start position:0% +um i'm not available for some reason you +can reach out to her + + align:start position:0% +can reach out to her + + + align:start position:0% +can reach out to her +um so now let me give you sort of the + + align:start position:0% +um so now let me give you sort of the + + + align:start position:0% +um so now let me give you sort of the +overview of the class + + align:start position:0% +overview of the class + + + align:start position:0% +overview of the class +i'm going to start sort of uh reading + + align:start position:0% +i'm going to start sort of uh reading + + + align:start position:0% +i'm going to start sort of uh reading +through four things one first i'm going + + align:start position:0% +through four things one first i'm going + + + align:start position:0% +through four things one first i'm going +to sort of tell you what is this class + + align:start position:0% +to sort of tell you what is this class + + + align:start position:0% +to sort of tell you what is this class +what is behavioral economics or what is + + align:start position:0% +what is behavioral economics or what is + + + align:start position:0% +what is behavioral economics or what is +psychology economics what do we mean by + + align:start position:0% +psychology economics what do we mean by + + + align:start position:0% +psychology economics what do we mean by +that is it sort of just putting two + + align:start position:0% +that is it sort of just putting two + + + align:start position:0% +that is it sort of just putting two +fields together + + align:start position:0% +fields together + + + align:start position:0% +fields together +or is it something more specific which + + align:start position:0% +or is it something more specific which + + + align:start position:0% +or is it something more specific which +you'll argue uh it is + + align:start position:0% +you'll argue uh it is + + + align:start position:0% +you'll argue uh it is +i'm going to give you some example then + + align:start position:0% +i'm going to give you some example then + + + align:start position:0% +i'm going to give you some example then +about like um uh + + align:start position:0% +about like um uh + + + align:start position:0% +about like um uh +how you might sort of use behavioral + + align:start position:0% +how you might sort of use behavioral + + + align:start position:0% +how you might sort of use behavioral +economics um in a specific example + + align:start position:0% +economics um in a specific example + + + align:start position:0% +economics um in a specific example +uh and a policy that might affect all of + + align:start position:0% +uh and a policy that might affect all of + + + align:start position:0% +uh and a policy that might affect all of +you and in fact it will because we have + + align:start position:0% +you and in fact it will because we have + + + align:start position:0% +you and in fact it will because we have +a specific laptop policy in this class + + align:start position:0% +a specific laptop policy in this class + + + align:start position:0% +a specific laptop policy in this class +uh and we'll tell you a little bit how + + align:start position:0% +uh and we'll tell you a little bit how + + + align:start position:0% +uh and we'll tell you a little bit how +to think about this there will also be a + + align:start position:0% +to think about this there will also be a + + + align:start position:0% +to think about this there will also be a +problem set + + align:start position:0% +problem set + + + align:start position:0% +problem set +that will help you think about this a + + align:start position:0% +that will help you think about this a + + + align:start position:0% +that will help you think about this a +bit more uh then we talk about somewhat + + align:start position:0% +bit more uh then we talk about somewhat + + + align:start position:0% +bit more uh then we talk about somewhat +boring uh course logistics + + align:start position:0% +boring uh course logistics + + + align:start position:0% +boring uh course logistics +um and at the end we do a questionnaire + + align:start position:0% +um and at the end we do a questionnaire + + + align:start position:0% +um and at the end we do a questionnaire +quiz um for everybody + + align:start position:0% +quiz um for everybody + + + align:start position:0% +quiz um for everybody +in part because we want to know some + + align:start position:0% +in part because we want to know some + + + align:start position:0% +in part because we want to know some +information for you in part we want to + + align:start position:0% +information for you in part we want to + + + align:start position:0% +information for you in part we want to +sort of learn a little bit about + + align:start position:0% +sort of learn a little bit about + + + align:start position:0% +sort of learn a little bit about +some decisions that um you might make + + align:start position:0% +some decisions that um you might make + + + align:start position:0% +some decisions that um you might make +okay + + align:start position:0% +okay + + + align:start position:0% +okay +great sorry this is + + align:start position:0% +great sorry this is + + + align:start position:0% +great sorry this is +okay so what is um psychology economics + + align:start position:0% +okay so what is um psychology economics + + + align:start position:0% +okay so what is um psychology economics +so you may have heard of this uh the + + align:start position:0% +so you may have heard of this uh the + + + align:start position:0% +so you may have heard of this uh the +class used to be called economics and + + align:start position:0% +class used to be called economics and + + + align:start position:0% +class used to be called economics and +psychology + + align:start position:0% +psychology + + + align:start position:0% +psychology +or behavioral economics uh for our + + align:start position:0% +or behavioral economics uh for our + + + align:start position:0% +or behavioral economics uh for our +purposes that's kind of like all um + + align:start position:0% +purposes that's kind of like all um + + + align:start position:0% +purposes that's kind of like all um +um uh the same some economists sort of + + align:start position:0% +um uh the same some economists sort of + + + align:start position:0% +um uh the same some economists sort of +argue that um + + align:start position:0% +argue that um + + + align:start position:0% +argue that um +uh all economics is about behavior so + + align:start position:0% +uh all economics is about behavior so + + + align:start position:0% +uh all economics is about behavior so +like you know uh behavioral economics is + + align:start position:0% +like you know uh behavioral economics is + + + align:start position:0% +like you know uh behavioral economics is +sort of a bit of a weird word + + align:start position:0% +sort of a bit of a weird word + + + align:start position:0% +sort of a bit of a weird word +um so that's why partially i'm using + + align:start position:0% +um so that's why partially i'm using + + + align:start position:0% +um so that's why partially i'm using +sort of the word psychology and + + align:start position:0% +sort of the word psychology and + + + align:start position:0% +sort of the word psychology and +economics + + align:start position:0% +economics + + + align:start position:0% +economics +in some sense it's sort of broader than + + align:start position:0% +in some sense it's sort of broader than + + + align:start position:0% +in some sense it's sort of broader than +that one definition is it's a field + + align:start position:0% +that one definition is it's a field + + + align:start position:0% +that one definition is it's a field +of economic academic research that + + align:start position:0% +of economic academic research that + + + align:start position:0% +of economic academic research that +studies the joint influences of + + align:start position:0% +studies the joint influences of + + + align:start position:0% +studies the joint influences of +psychological and economic factors + + align:start position:0% +psychological and economic factors + + + align:start position:0% +psychological and economic factors +on behaviors you could be sort of + + align:start position:0% +on behaviors you could be sort of + + + align:start position:0% +on behaviors you could be sort of +broader and say we're trying to + + align:start position:0% +broader and say we're trying to + + + align:start position:0% +broader and say we're trying to +integrate insights from not just + + align:start position:0% +integrate insights from not just + + + align:start position:0% +integrate insights from not just +psychology but also anthropology + + align:start position:0% +psychology but also anthropology + + + align:start position:0% +psychology but also anthropology +sociology medicine + + align:start position:0% +sociology medicine + + + align:start position:0% +sociology medicine +psychiatry etc and so on into economics + + align:start position:0% +psychiatry etc and so on into economics + + + align:start position:0% +psychiatry etc and so on into economics +and trying with an attempt to make + + align:start position:0% +and trying with an attempt to make + + + align:start position:0% +and trying with an attempt to make +economic models + + align:start position:0% +economic models + + + align:start position:0% +economic models +more realistic and therefore more + + align:start position:0% +more realistic and therefore more + + + align:start position:0% +more realistic and therefore more +predictive and help us understand + + align:start position:0% +predictive and help us understand + + + align:start position:0% +predictive and help us understand +people's behavior better + + align:start position:0% +people's behavior better + + + align:start position:0% +people's behavior better +and then help us uh make better policies + + align:start position:0% +and then help us uh make better policies + + + align:start position:0% +and then help us uh make better policies +perhaps + + align:start position:0% +perhaps + + + align:start position:0% +perhaps +in trying to influence um people's + + align:start position:0% +in trying to influence um people's + + + align:start position:0% +in trying to influence um people's +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +now uh as i said you know that's + + align:start position:0% +now uh as i said you know that's + + + align:start position:0% +now uh as i said you know that's +medicine sociology etc + + align:start position:0% +medicine sociology etc + + + align:start position:0% +medicine sociology etc +broadly be trying to use insight from + + align:start position:0% +broadly be trying to use insight from + + + align:start position:0% +broadly be trying to use insight from +those fields and trying to understand + + align:start position:0% +those fields and trying to understand + + + align:start position:0% +those fields and trying to understand +have you missed something by + + align:start position:0% +have you missed something by + + + align:start position:0% +have you missed something by +making the fairly stark assumptions that + + align:start position:0% +making the fairly stark assumptions that + + + align:start position:0% +making the fairly stark assumptions that +economic models um usually + + align:start position:0% +economic models um usually + + + align:start position:0% +economic models um usually +make that leads me to what are the + + align:start position:0% +make that leads me to what are the + + + align:start position:0% +make that leads me to what are the +standard economics + + align:start position:0% +standard economics + + + align:start position:0% +standard economics +models in some sense what we're going to + + align:start position:0% +models in some sense what we're going to + + + align:start position:0% +models in some sense what we're going to +try and study to some degree is + + align:start position:0% +try and study to some degree is + + + align:start position:0% +try and study to some degree is +deviations from the classical or the + + align:start position:0% +deviations from the classical or the + + + align:start position:0% +deviations from the classical or the +the sort of the standard economic model + + align:start position:0% +the sort of the standard economic model + + + align:start position:0% +the sort of the standard economic model +so then of course we need to understand + + align:start position:0% +so then of course we need to understand + + + align:start position:0% +so then of course we need to understand +what is the standard economic models to + + align:start position:0% +what is the standard economic models to + + + align:start position:0% +what is the standard economic models to +start with + + align:start position:0% +start with + + + align:start position:0% +start with +which leads me to in part uh some + + align:start position:0% +which leads me to in part uh some + + + align:start position:0% +which leads me to in part uh some +prerequisites of the class or you should + + align:start position:0% +prerequisites of the class or you should + + + align:start position:0% +prerequisites of the class or you should +have taken at least some economics or + + align:start position:0% +have taken at least some economics or + + + align:start position:0% +have taken at least some economics or +know + + align:start position:0% +know + + + align:start position:0% +know +some economics to start with because i'm + + align:start position:0% +some economics to start with because i'm + + + align:start position:0% +some economics to start with because i'm +going to talk a lot about sort of + + align:start position:0% +going to talk a lot about sort of + + + align:start position:0% +going to talk a lot about sort of +deviations from those models and sort of + + align:start position:0% +deviations from those models and sort of + + + align:start position:0% +deviations from those models and sort of +if you haven't sort of taken any uh + + align:start position:0% +if you haven't sort of taken any uh + + + align:start position:0% +if you haven't sort of taken any uh +class before don't really + + align:start position:0% +class before don't really + + + align:start position:0% +class before don't really +know that very well then understanding + + align:start position:0% +know that very well then understanding + + + align:start position:0% +know that very well then understanding +the deviations will be a little bit + + align:start position:0% +the deviations will be a little bit + + + align:start position:0% +the deviations will be a little bit +tricky so for those of you who have + + align:start position:0% +tricky so for those of you who have + + + align:start position:0% +tricky so for those of you who have +taken economic classes what do we + + align:start position:0% +taken economic classes what do we + + + align:start position:0% +taken economic classes what do we +usually assume about people's behavior + + align:start position:0% +usually assume about people's behavior + + + align:start position:0% +usually assume about people's behavior +what are sort of some of the assumptions + + align:start position:0% +what are sort of some of the assumptions + + + align:start position:0% +what are sort of some of the assumptions +that we make + + align:start position:0% +that we make + + + align:start position:0% +that we make +about economic behavior + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +stable preferences yes um so first well + + align:start position:0% +stable preferences yes um so first well + + + align:start position:0% +stable preferences yes um so first well +defined preferences in the sense of like + + align:start position:0% +defined preferences in the sense of like + + + align:start position:0% +defined preferences in the sense of like +people know what their preferences are + + align:start position:0% +people know what their preferences are + + + align:start position:0% +people know what their preferences are +they can state them + + align:start position:0% +they can state them + + + align:start position:0% +they can state them +and then they're also stable in a sense + + align:start position:0% +and then they're also stable in a sense + + + align:start position:0% +and then they're also stable in a sense +of like when i ask you today + + align:start position:0% +of like when i ask you today + + + align:start position:0% +of like when i ask you today +would you rather have apples or bananas + + align:start position:0% +would you rather have apples or bananas + + + align:start position:0% +would you rather have apples or bananas +um uh that'll + + align:start position:0% +um uh that'll + + + align:start position:0% +um uh that'll +not change unless they're sort of new + + align:start position:0% +not change unless they're sort of new + + + align:start position:0% +not change unless they're sort of new +information or your circumstances change + + align:start position:0% +information or your circumstances change + + + align:start position:0% +information or your circumstances change +of course if i ask you tomorrow and you + + align:start position:0% +of course if i ask you tomorrow and you + + + align:start position:0% +of course if i ask you tomorrow and you +already have a bunch of apples and then + + align:start position:0% +already have a bunch of apples and then + + + align:start position:0% +already have a bunch of apples and then +you'd say you want bananas + + align:start position:0% +you'd say you want bananas + + + align:start position:0% +you'd say you want bananas +that doesn't mean your preferences have + + align:start position:0% +that doesn't mean your preferences have + + + align:start position:0% +that doesn't mean your preferences have +changed but if i ask you about + + align:start position:0% +changed but if i ask you about + + + align:start position:0% +changed but if i ask you about +tomorrow what would you like for lunch + + align:start position:0% +tomorrow what would you like for lunch + + + align:start position:0% +tomorrow what would you like for lunch +you tell me a choice you want apples + + align:start position:0% +you tell me a choice you want apples + + + align:start position:0% +you tell me a choice you want apples +rather than bananas + + align:start position:0% +rather than bananas + + + align:start position:0% +rather than bananas +and then tomorrow you show up and + + align:start position:0% +and then tomorrow you show up and + + + align:start position:0% +and then tomorrow you show up and +nothing else has changed and you say now + + align:start position:0% +nothing else has changed and you say now + + + align:start position:0% +nothing else has changed and you say now +i want bananas well then your + + align:start position:0% +i want bananas well then your + + + align:start position:0% +i want bananas well then your +preferences are not + + align:start position:0% +preferences are not + + + align:start position:0% +preferences are not +stable that's one assumption yes what + + align:start position:0% +stable that's one assumption yes what + + + align:start position:0% +stable that's one assumption yes what +else do you have yeah + + align:start position:0% +else do you have yeah + + + align:start position:0% +else do you have yeah +more broadly they're rational yes and + + align:start position:0% +more broadly they're rational yes and + + + align:start position:0% +more broadly they're rational yes and +what does that mean + + align:start position:0% +what does that mean + + + align:start position:0% +what does that mean +they behave deterministically to + + align:start position:0% +they behave deterministically to + + + align:start position:0% +they behave deterministically to +optimize some utility function + + align:start position:0% +optimize some utility function + + + align:start position:0% +optimize some utility function +right exactly so people essentially + + align:start position:0% +right exactly so people essentially + + + align:start position:0% +right exactly so people essentially +optimize some utility functions so we + + align:start position:0% +optimize some utility functions so we + + + align:start position:0% +optimize some utility functions so we +say here people + + align:start position:0% +say here people + + + align:start position:0% +say here people +have a utility function they know what + + align:start position:0% +have a utility function they know what + + + align:start position:0% +have a utility function they know what +that is and you're sort of saying that + + align:start position:0% +that is and you're sort of saying that + + + align:start position:0% +that is and you're sort of saying that +maximize it to to optimize in a certain + + align:start position:0% +maximize it to to optimize in a certain + + + align:start position:0% +maximize it to to optimize in a certain +way they don't make mistakes in that + + align:start position:0% +way they don't make mistakes in that + + + align:start position:0% +way they don't make mistakes in that +maximization + + align:start position:0% +maximization + + + align:start position:0% +maximization +process so that's to say if you tell me + + align:start position:0% +process so that's to say if you tell me + + + align:start position:0% +process so that's to say if you tell me +you like apples + + align:start position:0% +you like apples + + + align:start position:0% +you like apples +over bananas uh and then you choose + + align:start position:0% +over bananas uh and then you choose + + + align:start position:0% +over bananas uh and then you choose +bananas well then you know something is + + align:start position:0% +bananas well then you know something is + + + align:start position:0% +bananas well then you know something is +sort of going wrong in some ways that we + + align:start position:0% +sort of going wrong in some ways that we + + + align:start position:0% +sort of going wrong in some ways that we +haven't fully understood it might be + + align:start position:0% +haven't fully understood it might be + + + align:start position:0% +haven't fully understood it might be +that you're sort of like just making + + align:start position:0% +that you're sort of like just making + + + align:start position:0% +that you're sort of like just making +uh mistakes that could be construed as + + align:start position:0% +uh mistakes that could be construed as + + + align:start position:0% +uh mistakes that could be construed as +uh irrational it's hard to rationalize + + align:start position:0% +uh irrational it's hard to rationalize + + + align:start position:0% +uh irrational it's hard to rationalize +with a model + + align:start position:0% +with a model + + + align:start position:0% +with a model +what else + + align:start position:0% + + + + align:start position:0% + +self-interest yes so like usually in a + + align:start position:0% +self-interest yes so like usually in a + + + align:start position:0% +self-interest yes so like usually in a +lot of models um + + align:start position:0% +lot of models um + + + align:start position:0% +lot of models um +all like the sort of the the easiest + + align:start position:0% +all like the sort of the the easiest + + + align:start position:0% +all like the sort of the the easiest +models are very narrowly defined + + align:start position:0% +models are very narrowly defined + + + align:start position:0% +models are very narrowly defined +self-interest so people care about + + align:start position:0% +self-interest so people care about + + + align:start position:0% +self-interest so people care about +themselves they care about what they + + align:start position:0% +themselves they care about what they + + + align:start position:0% +themselves they care about what they +consume and not about what others + + align:start position:0% +consume and not about what others + + + align:start position:0% +consume and not about what others +consume or + + align:start position:0% +consume or + + + align:start position:0% +consume or +or or what others think of them sort of + + align:start position:0% +or or what others think of them sort of + + + align:start position:0% +or or what others think of them sort of +narrowly defined + + align:start position:0% +narrowly defined + + + align:start position:0% +narrowly defined +self-interest yes + + align:start position:0% + + + + align:start position:0% + +yes so essentially perfect self-control + + align:start position:0% +yes so essentially perfect self-control + + + align:start position:0% +yes so essentially perfect self-control +usually a sort of + + align:start position:0% +usually a sort of + + + align:start position:0% +usually a sort of +one version of putting that one version + + align:start position:0% +one version of putting that one version + + + align:start position:0% +one version of putting that one version +of putting that is in some sense sort of + + align:start position:0% +of putting that is in some sense sort of + + + align:start position:0% +of putting that is in some sense sort of +going back to what you're saying earlier + + align:start position:0% +going back to what you're saying earlier + + + align:start position:0% +going back to what you're saying earlier +sort of to say stable preferences + + align:start position:0% +sort of to say stable preferences + + + align:start position:0% +sort of to say stable preferences +if i'm telling you i'd like to exercise + + align:start position:0% +if i'm telling you i'd like to exercise + + + align:start position:0% +if i'm telling you i'd like to exercise +tomorrow and that's my preference + + align:start position:0% +tomorrow and that's my preference + + + align:start position:0% +tomorrow and that's my preference +uh tomorrow i'm not gonna sort of be + + align:start position:0% +uh tomorrow i'm not gonna sort of be + + + align:start position:0% +uh tomorrow i'm not gonna sort of be +like oh yeah actually you know i changed + + align:start position:0% +like oh yeah actually you know i changed + + + align:start position:0% +like oh yeah actually you know i changed +my mind and now i'm just watching movies + + align:start position:0% +my mind and now i'm just watching movies + + + align:start position:0% +my mind and now i'm just watching movies +or the like + + align:start position:0% +or the like + + + align:start position:0% +or the like +right so that's the version of sort of + + align:start position:0% +right so that's the version of sort of + + + align:start position:0% +right so that's the version of sort of +preferences being stable but + + align:start position:0% +preferences being stable but + + + align:start position:0% +preferences being stable but +the inherent underlying issue there is + + align:start position:0% +the inherent underlying issue there is + + + align:start position:0% +the inherent underlying issue there is +like self-control problems in the sense + + align:start position:0% +like self-control problems in the sense + + + align:start position:0% +like self-control problems in the sense +of like + + align:start position:0% +of like + + + align:start position:0% +of like +if i like certain things or make certain + + align:start position:0% +if i like certain things or make certain + + + align:start position:0% +if i like certain things or make certain +plans for the future + + align:start position:0% +plans for the future + + + align:start position:0% +plans for the future +i have the self-control to follow + + align:start position:0% +i have the self-control to follow + + + align:start position:0% +i have the self-control to follow +through on those plans that's usually an + + align:start position:0% +through on those plans that's usually an + + + align:start position:0% +through on those plans that's usually an +assumption and that + + align:start position:0% +assumption and that + + + align:start position:0% +assumption and that +then shows up as preferences being + + align:start position:0% +then shows up as preferences being + + + align:start position:0% +then shows up as preferences being +stable + + align:start position:0% +stable + + + align:start position:0% +stable +what else yeah + + align:start position:0% + + + + align:start position:0% + +yeah so usually there is like a discount + + align:start position:0% +yeah so usually there is like a discount + + + align:start position:0% +yeah so usually there is like a discount +um factor in terms of like how much you + + align:start position:0% +um factor in terms of like how much you + + + align:start position:0% +um factor in terms of like how much you +uh like consumption today versus + + align:start position:0% +uh like consumption today versus + + + align:start position:0% +uh like consumption today versus +consumption tomorrow + + align:start position:0% +consumption tomorrow + + + align:start position:0% +consumption tomorrow +um that is usually in any economic model + + align:start position:0% +um that is usually in any economic model + + + align:start position:0% +um that is usually in any economic model +usually we think of like the discount + + align:start position:0% +usually we think of like the discount + + + align:start position:0% +usually we think of like the discount +factor being + + align:start position:0% +factor being + + + align:start position:0% +factor being +constant as like how you think about + + align:start position:0% +constant as like how you think about + + + align:start position:0% +constant as like how you think about +today versus tomorrow is the same + + align:start position:0% +today versus tomorrow is the same + + + align:start position:0% +today versus tomorrow is the same +as you think about today versus in two + + align:start position:0% +as you think about today versus in two + + + align:start position:0% +as you think about today versus in two +days from now or in like a year from now + + align:start position:0% +days from now or in like a year from now + + + align:start position:0% +days from now or in like a year from now +and a year and a day from now so usually + + align:start position:0% +and a year and a day from now so usually + + + align:start position:0% +and a year and a day from now so usually +there's a constant discount factor for + + align:start position:0% +there's a constant discount factor for + + + align:start position:0% +there's a constant discount factor for +the future usually + + align:start position:0% +the future usually + + + align:start position:0% +the future usually +we sort of employ economic sorry + + align:start position:0% +we sort of employ economic sorry + + + align:start position:0% +we sort of employ economic sorry +constant discounting or exponential + + align:start position:0% +constant discounting or exponential + + + align:start position:0% +constant discounting or exponential +discounting + + align:start position:0% +discounting + + + align:start position:0% +discounting +what else do we have yeah risk reverse + + align:start position:0% +what else do we have yeah risk reverse + + + align:start position:0% +what else do we have yeah risk reverse +yes risk aversion in the sense of like + + align:start position:0% +yes risk aversion in the sense of like + + + align:start position:0% +yes risk aversion in the sense of like +yes people um + + align:start position:0% +yes people um + + + align:start position:0% +yes people um +are risk-averse and people often sort of + + align:start position:0% +are risk-averse and people often sort of + + + align:start position:0% +are risk-averse and people often sort of +define their preferences over + + align:start position:0% +define their preferences over + + + align:start position:0% +define their preferences over +outcome so we have a utility function + + align:start position:0% +outcome so we have a utility function + + + align:start position:0% +outcome so we have a utility function +that we tend to concave and the utility + + align:start position:0% +that we tend to concave and the utility + + + align:start position:0% +that we tend to concave and the utility +function + + align:start position:0% +function + + + align:start position:0% +function +is and we'll get to this in a few + + align:start position:0% +is and we'll get to this in a few + + + align:start position:0% +is and we'll get to this in a few +lectures but the utility function tends + + align:start position:0% +lectures but the utility function tends + + + align:start position:0% +lectures but the utility function tends +is concave and it's defined over outcome + + align:start position:0% +is concave and it's defined over outcome + + + align:start position:0% +is concave and it's defined over outcome +as opposed to over + + align:start position:0% +as opposed to over + + + align:start position:0% +as opposed to over +changes of outcomes that shows up + + align:start position:0% +changes of outcomes that shows up + + + align:start position:0% +changes of outcomes that shows up +usually as sort of like essentially like + + align:start position:0% +usually as sort of like essentially like + + + align:start position:0% +usually as sort of like essentially like +a + + align:start position:0% +a + + + align:start position:0% +a +a strictly concave utility function and + + align:start position:0% +a strictly concave utility function and + + + align:start position:0% +a strictly concave utility function and +that's + + align:start position:0% +that's + + + align:start position:0% +that's +risk aversion what about information how + + align:start position:0% +risk aversion what about information how + + + align:start position:0% +risk aversion what about information how +do people + + align:start position:0% +do people + + + align:start position:0% +do people +think about information how do they use + + align:start position:0% +think about information how do they use + + + align:start position:0% +think about information how do they use +information + + align:start position:0% +information + + + align:start position:0% +information +bayesian and what what does that mean + + align:start position:0% + + + + align:start position:0% + +exactly so people essentially are + + align:start position:0% +exactly so people essentially are + + + align:start position:0% +exactly so people essentially are +perfect uh information + + align:start position:0% +perfect uh information + + + align:start position:0% +perfect uh information +processors you can call them bayesians + + align:start position:0% +processors you can call them bayesians + + + align:start position:0% +processors you can call them bayesians +but essentially it's sort of for those + + align:start position:0% +but essentially it's sort of for those + + + align:start position:0% +but essentially it's sort of for those +of you know that it's sort of the use + + align:start position:0% +of you know that it's sort of the use + + + align:start position:0% +of you know that it's sort of the use +bayes rule essentially + + align:start position:0% +bayes rule essentially + + + align:start position:0% +bayes rule essentially +which is to say uh if you gave a + + align:start position:0% +which is to say uh if you gave a + + + align:start position:0% +which is to say uh if you gave a +statistician a problem how to update + + align:start position:0% +statistician a problem how to update + + + align:start position:0% +statistician a problem how to update +information + + align:start position:0% +information + + + align:start position:0% +information +people are able to do that in their + + align:start position:0% +people are able to do that in their + + + align:start position:0% +people are able to do that in their +heads and you know that's a pretty stark + + align:start position:0% +heads and you know that's a pretty stark + + + align:start position:0% +heads and you know that's a pretty stark +assumption but essentially it's like + + align:start position:0% +assumption but essentially it's like + + + align:start position:0% +assumption but essentially it's like +when you people have certain information + + align:start position:0% +when you people have certain information + + + align:start position:0% +when you people have certain information +uh standard economics does not + + align:start position:0% +uh standard economics does not + + + align:start position:0% +uh standard economics does not +necessarily assume that everybody has + + align:start position:0% +necessarily assume that everybody has + + + align:start position:0% +necessarily assume that everybody has +full information in a sense that + + align:start position:0% +full information in a sense that + + + align:start position:0% +full information in a sense that +everybody knows everything + + align:start position:0% +everybody knows everything + + + align:start position:0% +everybody knows everything +but if you give them some information + + align:start position:0% +but if you give them some information + + + align:start position:0% +but if you give them some information +then they update + + align:start position:0% +then they update + + + align:start position:0% +then they update +their uh beliefs accordingly right so + + align:start position:0% +their uh beliefs accordingly right so + + + align:start position:0% +their uh beliefs accordingly right so +they essentially they optimally use new + + align:start position:0% +they essentially they optimally use new + + + align:start position:0% +they essentially they optimally use new +information and then form their beliefs + + align:start position:0% +information and then form their beliefs + + + align:start position:0% +information and then form their beliefs +their posterior beliefs based on having + + align:start position:0% +their posterior beliefs based on having + + + align:start position:0% +their posterior beliefs based on having +a new information and what they believed + + align:start position:0% +a new information and what they believed + + + align:start position:0% +a new information and what they believed +previously um their priors there's + + align:start position:0% +previously um their priors there's + + + align:start position:0% +previously um their priors there's +another assumption usually and i sort of + + align:start position:0% +another assumption usually and i sort of + + + align:start position:0% +another assumption usually and i sort of +can actually + + align:start position:0% +can actually + + + align:start position:0% +can actually +sort of put this out for you which is + + align:start position:0% +sort of put this out for you which is + + + align:start position:0% +sort of put this out for you which is +there's another assumption that is + + align:start position:0% +there's another assumption that is + + + align:start position:0% +there's another assumption that is +people have no taste for beliefs or + + align:start position:0% +people have no taste for beliefs or + + + align:start position:0% +people have no taste for beliefs or +information + + align:start position:0% +information + + + align:start position:0% +information +what do we mean by that we mean by that + + align:start position:0% +what do we mean by that we mean by that + + + align:start position:0% +what do we mean by that we mean by that +as essentially people use + + align:start position:0% +as essentially people use + + + align:start position:0% +as essentially people use +information only to make decisions so if + + align:start position:0% +information only to make decisions so if + + + align:start position:0% +information only to make decisions so if +you tell me something about like what's + + align:start position:0% +you tell me something about like what's + + + align:start position:0% +you tell me something about like what's +going to happen tomorrow or if you tell + + align:start position:0% +going to happen tomorrow or if you tell + + + align:start position:0% +going to happen tomorrow or if you tell +me something about + + align:start position:0% +me something about + + + align:start position:0% +me something about +my health status or the like i use that + + align:start position:0% +my health status or the like i use that + + + align:start position:0% +my health status or the like i use that +to make better decisions so if you tell + + align:start position:0% +to make better decisions so if you tell + + + align:start position:0% +to make better decisions so if you tell +me i'm sick + + align:start position:0% +me i'm sick + + + align:start position:0% +me i'm sick +i'm going to use that information to go + + align:start position:0% +i'm going to use that information to go + + + align:start position:0% +i'm going to use that information to go +to the doctor + + align:start position:0% +to the doctor + + + align:start position:0% +to the doctor +but people usually don't assume that + + align:start position:0% +but people usually don't assume that + + + align:start position:0% +but people usually don't assume that +people have certain beliefs about + + align:start position:0% +people have certain beliefs about + + + align:start position:0% +people have certain beliefs about +whether they're sick or healthy or + + align:start position:0% +whether they're sick or healthy or + + + align:start position:0% +whether they're sick or healthy or +whether they're smart or not or are they + + align:start position:0% +whether they're smart or not or are they + + + align:start position:0% +whether they're smart or not or are they +good looking or not + + align:start position:0% +good looking or not + + + align:start position:0% +good looking or not +usually the assumption is that beliefs + + align:start position:0% +usually the assumption is that beliefs + + + align:start position:0% +usually the assumption is that beliefs +are only used so information is only + + align:start position:0% +are only used so information is only + + + align:start position:0% +are only used so information is only +used to make better decisions + + align:start position:0% +used to make better decisions + + + align:start position:0% +used to make better decisions +not that people get utility from beliefs + + align:start position:0% +not that people get utility from beliefs + + + align:start position:0% +not that people get utility from beliefs +but instead you might say well i'm + + align:start position:0% +but instead you might say well i'm + + + align:start position:0% +but instead you might say well i'm +really good looking and smart + + align:start position:0% +really good looking and smart + + + align:start position:0% +really good looking and smart +and maybe smarter than you actually are + + align:start position:0% +and maybe smarter than you actually are + + + align:start position:0% +and maybe smarter than you actually are +and the reason why people might believe + + align:start position:0% +and the reason why people might believe + + + align:start position:0% +and the reason why people might believe +that is because that makes them feel + + align:start position:0% +that is because that makes them feel + + + align:start position:0% +that is because that makes them feel +good about themselves + + align:start position:0% +good about themselves + + + align:start position:0% +good about themselves +that's what they're usually an + + align:start position:0% +that's what they're usually an + + + align:start position:0% +that's what they're usually an +assumption that + + align:start position:0% +assumption that + + + align:start position:0% +assumption that +people standard economic models make + + align:start position:0% +people standard economic models make + + + align:start position:0% +people standard economic models make +i think we mentioned almost everything + + align:start position:0% +i think we mentioned almost everything + + + align:start position:0% +i think we mentioned almost everything +we sort of said bayesian information + + align:start position:0% +we sort of said bayesian information + + + align:start position:0% +we sort of said bayesian information +processor essentially + + align:start position:0% +processor essentially + + + align:start position:0% +processor essentially +processing information optimally + + align:start position:0% +processing information optimally + + + align:start position:0% +processing information optimally +well-defined and stable preferences + + align:start position:0% +well-defined and stable preferences + + + align:start position:0% +well-defined and stable preferences +maximize expected utility which is sort + + align:start position:0% +maximize expected utility which is sort + + + align:start position:0% +maximize expected utility which is sort +of like in some sense um + + align:start position:0% +of like in some sense um + + + align:start position:0% +of like in some sense um +rationality if you want apply + + align:start position:0% +rationality if you want apply + + + align:start position:0% +rationality if you want apply +exponential discount weighting + + align:start position:0% +exponential discount weighting + + + align:start position:0% +exponential discount weighting +a current and future well-being people + + align:start position:0% +a current and future well-being people + + + align:start position:0% +a current and future well-being people +are narrowly + + align:start position:0% +are narrowly + + + align:start position:0% +are narrowly +defined in terms of their self-interest + + align:start position:0% +defined in terms of their self-interest + + + align:start position:0% +defined in terms of their self-interest +and people have preferences over final + + align:start position:0% +and people have preferences over final + + + align:start position:0% +and people have preferences over final +outcomes not changes + + align:start position:0% +outcomes not changes + + + align:start position:0% +outcomes not changes +so what you care about is how the + + align:start position:0% +so what you care about is how the + + + align:start position:0% +so what you care about is how the +weather is today not kind of like how + + align:start position:0% +weather is today not kind of like how + + + align:start position:0% +weather is today not kind of like how +the weather changed between yesterday um + + align:start position:0% +the weather changed between yesterday um + + + align:start position:0% +the weather changed between yesterday um +and today or tomorrow and we'll talk + + align:start position:0% +and today or tomorrow and we'll talk + + + align:start position:0% +and today or tomorrow and we'll talk +about all of these + + align:start position:0% +about all of these + + + align:start position:0% +about all of these +by the way these are all sort of like + + align:start position:0% +by the way these are all sort of like + + + align:start position:0% +by the way these are all sort of like +some terms that seem maybe + + align:start position:0% +some terms that seem maybe + + + align:start position:0% +some terms that seem maybe +unfamiliar to you we'll talk about all + + align:start position:0% +unfamiliar to you we'll talk about all + + + align:start position:0% +unfamiliar to you we'll talk about all +of these kinds of assumptions and + + align:start position:0% +of these kinds of assumptions and + + + align:start position:0% +of these kinds of assumptions and +perhaps how to deviate from them + + align:start position:0% +perhaps how to deviate from them + + + align:start position:0% +perhaps how to deviate from them +specifically okay so now now that we + + align:start position:0% +specifically okay so now now that we + + + align:start position:0% +specifically okay so now now that we +have those + + align:start position:0% +have those + + + align:start position:0% +have those +assumptions now what kinds of deviations + + align:start position:0% +assumptions now what kinds of deviations + + + align:start position:0% +assumptions now what kinds of deviations +uh when you look into the world and sort + + align:start position:0% +uh when you look into the world and sort + + + align:start position:0% +uh when you look into the world and sort +of + + align:start position:0% +of + + + align:start position:0% +of +one part how you think about behavioral + + align:start position:0% +one part how you think about behavioral + + + align:start position:0% +one part how you think about behavioral +economics is uh in some sense think + + align:start position:0% +economics is uh in some sense think + + + align:start position:0% +economics is uh in some sense think +about the world and try to sort of + + align:start position:0% +about the world and try to sort of + + + align:start position:0% +about the world and try to sort of +observe what's going on in the world + + align:start position:0% +observe what's going on in the world + + + align:start position:0% +observe what's going on in the world +and try to see which assumptions might + + align:start position:0% +and try to see which assumptions might + + + align:start position:0% +and try to see which assumptions might +be violated um + + align:start position:0% +be violated um + + + align:start position:0% +be violated um +in an important way and try to sort of + + align:start position:0% +in an important way and try to sort of + + + align:start position:0% +in an important way and try to sort of +improve our models + + align:start position:0% +improve our models + + + align:start position:0% +improve our models +so when you think about the world and + + align:start position:0% +so when you think about the world and + + + align:start position:0% +so when you think about the world and +look at these assumptions can you come + + align:start position:0% +look at these assumptions can you come + + + align:start position:0% +look at these assumptions can you come +up with real world examples + + align:start position:0% +up with real world examples + + + align:start position:0% +up with real world examples +um uh that might sort of violate these + + align:start position:0% +um uh that might sort of violate these + + + align:start position:0% +um uh that might sort of violate these +assumptions + + align:start position:0% + + + + align:start position:0% + +yes um the uh the last assumption + + align:start position:0% +yes um the uh the last assumption + + + align:start position:0% +yes um the uh the last assumption +that you listed uh the one + + align:start position:0% +that you listed uh the one + + + align:start position:0% +that you listed uh the one +beliefs or information is violated on a + + align:start position:0% +beliefs or information is violated on a + + + align:start position:0% +beliefs or information is violated on a +constant basis people + + align:start position:0% +constant basis people + + + align:start position:0% +constant basis people +tend to believe what they want to + + align:start position:0% +tend to believe what they want to + + + align:start position:0% +tend to believe what they want to +believe and you have an example specific + + align:start position:0% +believe and you have an example specific + + + align:start position:0% +believe and you have an example specific +um this is very common as regards like + + align:start position:0% +um this is very common as regards like + + + align:start position:0% +um this is very common as regards like +political matters i'm not gonna name + + align:start position:0% +political matters i'm not gonna name + + + align:start position:0% +political matters i'm not gonna name +like + + align:start position:0% + + + + align:start position:0% + +obvious reasons but uh like people + + align:start position:0% +obvious reasons but uh like people + + + align:start position:0% +obvious reasons but uh like people +like often like choose to discount + + align:start position:0% +like often like choose to discount + + + align:start position:0% +like often like choose to discount +information + + align:start position:0% +information + + + align:start position:0% +information +that goes against their belief right um + + align:start position:0% +that goes against their belief right um + + + align:start position:0% +that goes against their belief right um +right so + + align:start position:0% +right so + + + align:start position:0% +right so +um so one reason could be and there's uh + + align:start position:0% +um so one reason could be and there's uh + + + align:start position:0% +um so one reason could be and there's uh +quite a bit of work recently we'll talk + + align:start position:0% +quite a bit of work recently we'll talk + + + align:start position:0% +quite a bit of work recently we'll talk +a little bit about this in this class + + align:start position:0% +a little bit about this in this class + + + align:start position:0% +a little bit about this in this class +about sort of + + align:start position:0% +about sort of + + + align:start position:0% +about sort of +how political beliefs or other reasons + + align:start position:0% +how political beliefs or other reasons + + + align:start position:0% +how political beliefs or other reasons +why people might be + + align:start position:0% +why people might be + + + align:start position:0% +why people might be +motivated to believe certain things one + + align:start position:0% +motivated to believe certain things one + + + align:start position:0% +motivated to believe certain things one +clear example would be sort of climate + + align:start position:0% +clear example would be sort of climate + + + align:start position:0% +clear example would be sort of climate +change + + align:start position:0% +change + + + align:start position:0% +change +not just because of political reason + + align:start position:0% +not just because of political reason + + + align:start position:0% +not just because of political reason +there's some interesting work about like + + align:start position:0% +there's some interesting work about like + + + align:start position:0% +there's some interesting work about like +when people live in flood areas for + + align:start position:0% +when people live in flood areas for + + + align:start position:0% +when people live in flood areas for +example what do they think about climate + + align:start position:0% +example what do they think about climate + + + align:start position:0% +example what do they think about climate +change + + align:start position:0% +change + + + align:start position:0% +change +and sort of you might sort of say well + + align:start position:0% +and sort of you might sort of say well + + + align:start position:0% +and sort of you might sort of say well +if you really uh live in an area that's + + align:start position:0% +if you really uh live in an area that's + + + align:start position:0% +if you really uh live in an area that's +potentially + + align:start position:0% +potentially + + + align:start position:0% +potentially +affected by floods you might really want + + align:start position:0% +affected by floods you might really want + + + align:start position:0% +affected by floods you might really want +to know about climate change and know + + align:start position:0% +to know about climate change and know + + + align:start position:0% +to know about climate change and know +what's going on and really try to inform + + align:start position:0% +what's going on and really try to inform + + + align:start position:0% +what's going on and really try to inform +yourself + + align:start position:0% +yourself + + + align:start position:0% +yourself +but what people tend to do is sort of + + align:start position:0% +but what people tend to do is sort of + + + align:start position:0% +but what people tend to do is sort of +try to ignore the issue and try to sort + + align:start position:0% +try to ignore the issue and try to sort + + + align:start position:0% +try to ignore the issue and try to sort +of be happy + + align:start position:0% +of be happy + + + align:start position:0% +of be happy +as long as sort of uh nothing happens + + align:start position:0% +as long as sort of uh nothing happens + + + align:start position:0% +as long as sort of uh nothing happens +now that's one example yes + + align:start position:0% + + + + align:start position:0% + +yes um so purposes might not be well + + align:start position:0% +yes um so purposes might not be well + + + align:start position:0% +yes um so purposes might not be well +defined + + align:start position:0% +defined + + + align:start position:0% +defined +so say like if i have a decision on what + + align:start position:0% +so say like if i have a decision on what + + + align:start position:0% +so say like if i have a decision on what +i want to eat + + align:start position:0% +i want to eat + + + align:start position:0% +i want to eat +i want to eat like steak over chicken if + + align:start position:0% +i want to eat like steak over chicken if + + + align:start position:0% +i want to eat like steak over chicken if +i'm presented with the opportunity + + align:start position:0% +i'm presented with the opportunity + + + align:start position:0% +i'm presented with the opportunity +but i prefer chicken or pork + + align:start position:0% +but i prefer chicken or pork + + + align:start position:0% +but i prefer chicken or pork +but i might also prefer poor purple + + align:start position:0% +but i might also prefer poor purple + + + align:start position:0% +but i might also prefer poor purple +steak right so it's not always + + align:start position:0% +steak right so it's not always + + + align:start position:0% +steak right so it's not always +well defined right so one part that + + align:start position:0% +well defined right so one part that + + + align:start position:0% +well defined right so one part that +you're telling is like essentially so + + align:start position:0% +you're telling is like essentially so + + + align:start position:0% +you're telling is like essentially so +one one part might be it's might not + + align:start position:0% +one one part might be it's might not + + + align:start position:0% +one one part might be it's might not +just be well-defined + + align:start position:0% +just be well-defined + + + align:start position:0% +just be well-defined +there's other issues like for example + + align:start position:0% +there's other issues like for example + + + align:start position:0% +there's other issues like for example +that irrelevant other autism assumption + + align:start position:0% +that irrelevant other autism assumption + + + align:start position:0% +that irrelevant other autism assumption +economics usually is to say if you + + align:start position:0% +economics usually is to say if you + + + align:start position:0% +economics usually is to say if you +choose between a and b + + align:start position:0% +choose between a and b + + + align:start position:0% +choose between a and b +the availability of seed should not + + align:start position:0% +the availability of seed should not + + + align:start position:0% +the availability of seed should not +matter for your choice between a + + align:start position:0% +matter for your choice between a + + + align:start position:0% +matter for your choice between a +and b but often that's not the case + + align:start position:0% +and b but often that's not the case + + + align:start position:0% +and b but often that's not the case +right so if i offer you apples and + + align:start position:0% +right so if i offer you apples and + + + align:start position:0% +right so if i offer you apples and +bananas and you also can get cherries + + align:start position:0% +bananas and you also can get cherries + + + align:start position:0% +bananas and you also can get cherries +now suddenly your choice between apples + + align:start position:0% +now suddenly your choice between apples + + + align:start position:0% +now suddenly your choice between apples +and bananas might change + + align:start position:0% +and bananas might change + + + align:start position:0% +and bananas might change +even if you can't get the cherries like + + align:start position:0% +even if you can't get the cherries like + + + align:start position:0% +even if you can't get the cherries like +if i even if you don't choose the + + align:start position:0% +if i even if you don't choose the + + + align:start position:0% +if i even if you don't choose the +cherries um + + align:start position:0% +cherries um + + + align:start position:0% +cherries um +eventually so exactly so like there + + align:start position:0% +eventually so exactly so like there + + + align:start position:0% +eventually so exactly so like there +might be sort of people's preferences + + align:start position:0% +might be sort of people's preferences + + + align:start position:0% +might be sort of people's preferences +might not be + + align:start position:0% +might not be + + + align:start position:0% +might not be +uh well defined they might also not be + + align:start position:0% +uh well defined they might also not be + + + align:start position:0% +uh well defined they might also not be +stable + + align:start position:0% +stable + + + align:start position:0% +stable +any other example yes um also for the + + align:start position:0% +any other example yes um also for the + + + align:start position:0% +any other example yes um also for the +well-defined preferences like we have + + align:start position:0% +well-defined preferences like we have + + + align:start position:0% +well-defined preferences like we have +information processing constraints if + + align:start position:0% +information processing constraints if + + + align:start position:0% +information processing constraints if +i'm given a menu + + align:start position:0% +i'm given a menu + + + align:start position:0% +i'm given a menu +of 100 choices it's going to be + + align:start position:0% +of 100 choices it's going to be + + + align:start position:0% +of 100 choices it's going to be +difficult for me to + + align:start position:0% +difficult for me to + + + align:start position:0% +difficult for me to +know which one right exactly so the + + align:start position:0% +know which one right exactly so the + + + align:start position:0% +know which one right exactly so the +the people have lots of information + + align:start position:0% +the people have lots of information + + + align:start position:0% +the people have lots of information +around themselves and like if you think + + align:start position:0% +around themselves and like if you think + + + align:start position:0% +around themselves and like if you think +about like + + align:start position:0% +about like + + + align:start position:0% +about like +to process that information if you go to + + align:start position:0% +to process that information if you go to + + + align:start position:0% +to process that information if you go to +a supermarket it's impossible to know + + align:start position:0% +a supermarket it's impossible to know + + + align:start position:0% +a supermarket it's impossible to know +uh all the prices all the goods and make + + align:start position:0% +uh all the prices all the goods and make + + + align:start position:0% +uh all the prices all the goods and make +all these choices so in some sense we're + + align:start position:0% +all these choices so in some sense we're + + + align:start position:0% +all these choices so in some sense we're +like there's an abundance of + + align:start position:0% +like there's an abundance of + + + align:start position:0% +like there's an abundance of +information everywhere and you know we + + align:start position:0% +information everywhere and you know we + + + align:start position:0% +information everywhere and you know we +have to sort of figure out how to how to + + align:start position:0% +have to sort of figure out how to how to + + + align:start position:0% +have to sort of figure out how to how to +deal with + + align:start position:0% +deal with + + + align:start position:0% +deal with +with that any other example yes + + align:start position:0% + + + + align:start position:0% + +right exactly so one part is to say + + align:start position:0% +right exactly so one part is to say + + + align:start position:0% +right exactly so one part is to say +people + + align:start position:0% +people + + + align:start position:0% +people +um have preferences of a final outcome + + align:start position:0% +um have preferences of a final outcome + + + align:start position:0% +um have preferences of a final outcome +not changes which would just say + + align:start position:0% +not changes which would just say + + + align:start position:0% +not changes which would just say +uh you know you might feel about the + + align:start position:0% +uh you know you might feel about the + + + align:start position:0% +uh you know you might feel about the +weather in certain ways + + align:start position:0% +weather in certain ways + + + align:start position:0% +weather in certain ways +uh um you know depending on like how the + + align:start position:0% +uh um you know depending on like how the + + + align:start position:0% +uh um you know depending on like how the +weather was yesterday + + align:start position:0% +weather was yesterday + + + align:start position:0% +weather was yesterday +another version of that would be like + + align:start position:0% +another version of that would be like + + + align:start position:0% +another version of that would be like +you evaluate your + + align:start position:0% +you evaluate your + + + align:start position:0% +you evaluate your +the outcomes that you get based on your + + align:start position:0% +the outcomes that you get based on your + + + align:start position:0% +the outcomes that you get based on your +expectations and sort of if you thought + + align:start position:0% +expectations and sort of if you thought + + + align:start position:0% +expectations and sort of if you thought +you know today is going to be really + + align:start position:0% +you know today is going to be really + + + align:start position:0% +you know today is going to be really +nice + + align:start position:0% +nice + + + align:start position:0% +nice +uh or you know today is something that + + align:start position:0% +uh or you know today is something that + + + align:start position:0% +uh or you know today is something that +your day is going to be really good but + + align:start position:0% +your day is going to be really good but + + + align:start position:0% +your day is going to be really good but +then it happened to be not as good for + + align:start position:0% +then it happened to be not as good for + + + align:start position:0% +then it happened to be not as good for +whatever reason the weather is bad + + align:start position:0% +whatever reason the weather is bad + + + align:start position:0% +whatever reason the weather is bad +or you know something bad happened to + + align:start position:0% +or you know something bad happened to + + + align:start position:0% +or you know something bad happened to +you today the typical assumption would + + align:start position:0% +you today the typical assumption would + + + align:start position:0% +you today the typical assumption would +be to say well + + align:start position:0% +be to say well + + + align:start position:0% +be to say well +um you should just evaluate the final + + align:start position:0% +um you should just evaluate the final + + + align:start position:0% +um you should just evaluate the final +outcome it shouldn't matter what you + + align:start position:0% +outcome it shouldn't matter what you + + + align:start position:0% +outcome it shouldn't matter what you +thought about previously would what + + align:start position:0% +thought about previously would what + + + align:start position:0% +thought about previously would what +might happen + + align:start position:0% +might happen + + + align:start position:0% +might happen +you're going to look at like what + + align:start position:0% +you're going to look at like what + + + align:start position:0% +you're going to look at like what +happens at the end and that's how you + + align:start position:0% +happens at the end and that's how you + + + align:start position:0% +happens at the end and that's how you +evaluate your + + align:start position:0% +evaluate your + + + align:start position:0% +evaluate your +uh your well-being + + align:start position:0% + + + + align:start position:0% + +yes um you might need a commitment + + align:start position:0% +yes um you might need a commitment + + + align:start position:0% +yes um you might need a commitment +device + + align:start position:0% +device + + + align:start position:0% +device +so that you don't uh like you might + + align:start position:0% +so that you don't uh like you might + + + align:start position:0% +so that you don't uh like you might +avoid buying + + align:start position:0% +avoid buying + + + align:start position:0% +avoid buying +potato chips because you think you'll + + align:start position:0% +potato chips because you think you'll + + + align:start position:0% +potato chips because you think you'll +eat them that doesn't really make sense + + align:start position:0% +eat them that doesn't really make sense + + + align:start position:0% +eat them that doesn't really make sense +right so people might on purpose + + align:start position:0% +right so people might on purpose + + + align:start position:0% +right so people might on purpose +restrict their choices in certain ways + + align:start position:0% +restrict their choices in certain ways + + + align:start position:0% +restrict their choices in certain ways +right so you might sort of um and this + + align:start position:0% +right so you might sort of um and this + + + align:start position:0% +right so you might sort of um and this +is what gets me eventually to the + + align:start position:0% +is what gets me eventually to the + + + align:start position:0% +is what gets me eventually to the +laptop policy but people might sort of + + align:start position:0% +laptop policy but people might sort of + + + align:start position:0% +laptop policy but people might sort of +essentially know that in the future they + + align:start position:0% +essentially know that in the future they + + + align:start position:0% +essentially know that in the future they +make certain choices + + align:start position:0% +make certain choices + + + align:start position:0% +make certain choices +you might um for example + + align:start position:0% +you might um for example + + + align:start position:0% +you might um for example +in the laptop case you might say i'm + + align:start position:0% +in the laptop case you might say i'm + + + align:start position:0% +in the laptop case you might say i'm +gonna use a laptop in class + + align:start position:0% +gonna use a laptop in class + + + align:start position:0% +gonna use a laptop in class +with all the best intentions to taking + + align:start position:0% +with all the best intentions to taking + + + align:start position:0% +with all the best intentions to taking +notes and uh paying attention + + align:start position:0% +notes and uh paying attention + + + align:start position:0% +notes and uh paying attention +but you know at the end of the day you + + align:start position:0% +but you know at the end of the day you + + + align:start position:0% +but you know at the end of the day you +know you're gonna like watch the + + align:start position:0% +know you're gonna like watch the + + + align:start position:0% +know you're gonna like watch the +football review from yesterday or + + align:start position:0% +football review from yesterday or + + + align:start position:0% +football review from yesterday or +whatever other stuff comes up you're + + align:start position:0% +whatever other stuff comes up you're + + + align:start position:0% +whatever other stuff comes up you're +going to chat with your friends and so + + align:start position:0% +going to chat with your friends and so + + + align:start position:0% +going to chat with your friends and so +on and so forth + + align:start position:0% +on and so forth + + + align:start position:0% +on and so forth +so now in some sense if you're + + align:start position:0% +so now in some sense if you're + + + align:start position:0% +so now in some sense if you're +sophisticated as in like if you know + + align:start position:0% +sophisticated as in like if you know + + + align:start position:0% +sophisticated as in like if you know +um what you're going to do in case you + + align:start position:0% +um what you're going to do in case you + + + align:start position:0% +um what you're going to do in case you +sort of make certain choices + + align:start position:0% +sort of make certain choices + + + align:start position:0% +sort of make certain choices +you might say i choose not to even allow + + align:start position:0% +you might say i choose not to even allow + + + align:start position:0% +you might say i choose not to even allow +myself to use a laptop + + align:start position:0% +myself to use a laptop + + + align:start position:0% +myself to use a laptop +at all the reason being because i know + + align:start position:0% +at all the reason being because i know + + + align:start position:0% +at all the reason being because i know +that essentially + + align:start position:0% +that essentially + + + align:start position:0% +that essentially +i'm going to misbehave in the future and + + align:start position:0% +i'm going to misbehave in the future and + + + align:start position:0% +i'm going to misbehave in the future and +that's sort of we'll talk about this um + + align:start position:0% +that's sort of we'll talk about this um + + + align:start position:0% +that's sort of we'll talk about this um +soon i think in lecture three or four + + align:start position:0% +soon i think in lecture three or four + + + align:start position:0% +soon i think in lecture three or four +which is essentially people's demand for + + align:start position:0% +which is essentially people's demand for + + + align:start position:0% +which is essentially people's demand for +commitment as we call it which is to say + + align:start position:0% +commitment as we call it which is to say + + + align:start position:0% +commitment as we call it which is to say +people have demand for restricting their + + align:start position:0% +people have demand for restricting their + + + align:start position:0% +people have demand for restricting their +choice + + align:start position:0% +choice + + + align:start position:0% +choice +and in any neoclassical model does this + + align:start position:0% +and in any neoclassical model does this + + + align:start position:0% +and in any neoclassical model does this +make any sense because like you're going + + align:start position:0% +make any sense because like you're going + + + align:start position:0% +make any sense because like you're going +to choose optimally anyway and then you + + align:start position:0% +to choose optimally anyway and then you + + + align:start position:0% +to choose optimally anyway and then you +need to make + + align:start position:0% +need to make + + + align:start position:0% +need to make +the best choice for yourself in any case + + align:start position:0% +the best choice for yourself in any case + + + align:start position:0% +the best choice for yourself in any case +that's an assumption so why would you + + align:start position:0% +that's an assumption so why would you + + + align:start position:0% +that's an assumption so why would you +ever sort of shut down certain choices + + align:start position:0% +ever sort of shut down certain choices + + + align:start position:0% +ever sort of shut down certain choices +because for example in an emergency or + + align:start position:0% +because for example in an emergency or + + + align:start position:0% +because for example in an emergency or +there might be something really + + align:start position:0% +there might be something really + + + align:start position:0% +there might be something really +important coming up in class + + align:start position:0% +important coming up in class + + + align:start position:0% +important coming up in class +where you might want to use your laptop + + align:start position:0% +where you might want to use your laptop + + + align:start position:0% +where you might want to use your laptop +regardless of what's happening uh why + + align:start position:0% +regardless of what's happening uh why + + + align:start position:0% +regardless of what's happening uh why +would you shut that + + align:start position:0% +would you shut that + + + align:start position:0% +would you shut that +uh down exactly so demand for commitment + + align:start position:0% +uh down exactly so demand for commitment + + + align:start position:0% +uh down exactly so demand for commitment +is is is another example + + align:start position:0% +is is is another example + + + align:start position:0% +is is is another example +uh yes people are also not + + align:start position:0% +uh yes people are also not + + + align:start position:0% +uh yes people are also not +like anywhere near perfect uh invasion + + align:start position:0% +like anywhere near perfect uh invasion + + + align:start position:0% +like anywhere near perfect uh invasion +information processors either + + align:start position:0% +information processors either + + + align:start position:0% +information processors either +we are as a general rule + + align:start position:0% +we are as a general rule + + + align:start position:0% +we are as a general rule +people are pretty bad at uh + + align:start position:0% +people are pretty bad at uh + + + align:start position:0% +people are pretty bad at uh +updating their um you know + + align:start position:0% +updating their um you know + + + align:start position:0% +updating their um you know +their their beliefs based on new + + align:start position:0% +their their beliefs based on new + + + align:start position:0% +their their beliefs based on new +information and we frequently traffic + + align:start position:0% +information and we frequently traffic + + + align:start position:0% +information and we frequently traffic +in 100 and zero percent certainties + + align:start position:0% +in 100 and zero percent certainties + + + align:start position:0% +in 100 and zero percent certainties +like very often which um you know + + align:start position:0% +like very often which um you know + + + align:start position:0% +like very often which um you know +far more often than like what you would + + align:start position:0% +far more often than like what you would + + + align:start position:0% +far more often than like what you would +um expect from + + align:start position:0% +um expect from + + + align:start position:0% +um expect from +an invasion information right + + align:start position:0% +an invasion information right + + + align:start position:0% +an invasion information right +exactly so you know uh one summary of + + align:start position:0% +exactly so you know uh one summary of + + + align:start position:0% +exactly so you know uh one summary of +that is to say bayes rule a lot of this + + align:start position:0% +that is to say bayes rule a lot of this + + + align:start position:0% +that is to say bayes rule a lot of this +sort of updating uh behavior is really + + align:start position:0% +sort of updating uh behavior is really + + + align:start position:0% +sort of updating uh behavior is really +hard + + align:start position:0% +hard + + + align:start position:0% +hard +it's actually tough to do um and for + + align:start position:0% +it's actually tough to do um and for + + + align:start position:0% +it's actually tough to do um and for +those of you who do statistics math etc + + align:start position:0% +those of you who do statistics math etc + + + align:start position:0% +those of you who do statistics math etc +you might be able to do that very well + + align:start position:0% +you might be able to do that very well + + + align:start position:0% +you might be able to do that very well +but in way you're like a very small + + align:start position:0% +but in way you're like a very small + + + align:start position:0% +but in way you're like a very small +share of the population + + align:start position:0% +share of the population + + + align:start position:0% +share of the population +who actually uh uh does that well + + align:start position:0% +who actually uh uh does that well + + + align:start position:0% +who actually uh uh does that well +but even among those you know there's a + + align:start position:0% +but even among those you know there's a + + + align:start position:0% +but even among those you know there's a +bunch of + + align:start position:0% +bunch of + + + align:start position:0% +bunch of +stuff that's really hard to compute in + + align:start position:0% +stuff that's really hard to compute in + + + align:start position:0% +stuff that's really hard to compute in +your head uh you might be able to write + + align:start position:0% +your head uh you might be able to write + + + align:start position:0% +your head uh you might be able to write +it down and figure it out eventually + + align:start position:0% +it down and figure it out eventually + + + align:start position:0% +it down and figure it out eventually +but usually the assumption is that + + align:start position:0% +but usually the assumption is that + + + align:start position:0% +but usually the assumption is that +people just do all of this stuff in + + align:start position:0% +people just do all of this stuff in + + + align:start position:0% +people just do all of this stuff in +their heads and really complicated + + align:start position:0% +their heads and really complicated + + + align:start position:0% +their heads and really complicated +problems + + align:start position:0% +problems + + + align:start position:0% +problems +and you know that's that's sort of + + align:start position:0% +and you know that's that's sort of + + + align:start position:0% +and you know that's that's sort of +clearly not the case in many situations + + align:start position:0% +clearly not the case in many situations + + + align:start position:0% +clearly not the case in many situations +and then of course like um uh that's + + align:start position:0% +and then of course like um uh that's + + + align:start position:0% +and then of course like um uh that's +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +one part of that sort of among mit + + align:start position:0% +one part of that sort of among mit + + + align:start position:0% +one part of that sort of among mit +students uh but then you know + + align:start position:0% +students uh but then you know + + + align:start position:0% +students uh but then you know +um there's other populations that are um + + align:start position:0% +um there's other populations that are um + + + align:start position:0% +um there's other populations that are um +uh less educated they might not even + + align:start position:0% +uh less educated they might not even + + + align:start position:0% +uh less educated they might not even +know what bayes rule is + + align:start position:0% +know what bayes rule is + + + align:start position:0% +know what bayes rule is +uh uh they might be illiterate and so on + + align:start position:0% +uh uh they might be illiterate and so on + + + align:start position:0% +uh uh they might be illiterate and so on +and so forth so is there the assumption + + align:start position:0% +and so forth so is there the assumption + + + align:start position:0% +and so forth so is there the assumption +of like + + align:start position:0% +of like + + + align:start position:0% +of like +people's perfectly processing + + align:start position:0% +people's perfectly processing + + + align:start position:0% +people's perfectly processing +information is even perhaps more + + align:start position:0% +information is even perhaps more + + + align:start position:0% +information is even perhaps more +um um uh you know 10 years + + align:start position:0% + + + + align:start position:0% + +right so there's two parts to that + + align:start position:0% +right so there's two parts to that + + + align:start position:0% +right so there's two parts to that +there's essentially people + + align:start position:0% +there's essentially people + + + align:start position:0% +there's essentially people +uh this is essentially the assumption of + + align:start position:0% +uh this is essentially the assumption of + + + align:start position:0% +uh this is essentially the assumption of +narrowly defined self-interest people + + align:start position:0% +narrowly defined self-interest people + + + align:start position:0% +narrowly defined self-interest people +caring only about themselves of their + + align:start position:0% +caring only about themselves of their + + + align:start position:0% +caring only about themselves of their +own consumption + + align:start position:0% +own consumption + + + align:start position:0% +own consumption +so there's two parts to that one is you + + align:start position:0% +so there's two parts to that one is you + + + align:start position:0% +so there's two parts to that one is you +might care about your friends you might + + align:start position:0% +might care about your friends you might + + + align:start position:0% +might care about your friends you might +give money to your friends you might + + align:start position:0% +give money to your friends you might + + + align:start position:0% +give money to your friends you might +sort of help them out you might help + + align:start position:0% +sort of help them out you might help + + + align:start position:0% +sort of help them out you might help +them with homework you might help them + + align:start position:0% +them with homework you might help them + + + align:start position:0% +them with homework you might help them +in + + align:start position:0% +in + + + align:start position:0% +in +uh you know any other situations you + + align:start position:0% +uh you know any other situations you + + + align:start position:0% +uh you know any other situations you +might send money to charity and so on + + align:start position:0% +might send money to charity and so on + + + align:start position:0% +might send money to charity and so on +and so forth this is kind of like + + align:start position:0% +and so forth this is kind of like + + + align:start position:0% +and so forth this is kind of like +you care about other people like the + + align:start position:0% +you care about other people like the + + + align:start position:0% +you care about other people like the +well-being of other people is in your + + align:start position:0% +well-being of other people is in your + + + align:start position:0% +well-being of other people is in your +utility function one way or the other + + align:start position:0% +utility function one way or the other + + + align:start position:0% +utility function one way or the other +the second part is what you uh uh + + align:start position:0% +the second part is what you uh uh + + + align:start position:0% +the second part is what you uh uh +already uh + + align:start position:0% +already uh + + + align:start position:0% +already uh +discuss as well which is kind of like + + align:start position:0% +discuss as well which is kind of like + + + align:start position:0% +discuss as well which is kind of like +social influences call it which is + + align:start position:0% +social influences call it which is + + + align:start position:0% +social influences call it which is +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +peer effects you care a lot about what + + align:start position:0% +peer effects you care a lot about what + + + align:start position:0% +peer effects you care a lot about what +other people think about you + + align:start position:0% +other people think about you + + + align:start position:0% +other people think about you +you care a lot about what other people + + align:start position:0% +you care a lot about what other people + + + align:start position:0% +you care a lot about what other people +do people get jealous + + align:start position:0% +do people get jealous + + + align:start position:0% +do people get jealous +people get angry people get envious and + + align:start position:0% +people get angry people get envious and + + + align:start position:0% +people get angry people get envious and +sort of their behavior about what they + + align:start position:0% +sort of their behavior about what they + + + align:start position:0% +sort of their behavior about what they +want + + align:start position:0% +want + + + align:start position:0% +want +at the end of the day is very um + + align:start position:0% +at the end of the day is very um + + + align:start position:0% +at the end of the day is very um +volatile or malleable essentially based + + align:start position:0% +volatile or malleable essentially based + + + align:start position:0% +volatile or malleable essentially based +on uh influences from others + + align:start position:0% +on uh influences from others + + + align:start position:0% +on uh influences from others +right and that might sort of show up uh + + align:start position:0% +right and that might sort of show up uh + + + align:start position:0% +right and that might sort of show up uh +in all sorts of ways + + align:start position:0% +in all sorts of ways + + + align:start position:0% +in all sorts of ways +including in terms of like peer effects + + align:start position:0% +including in terms of like peer effects + + + align:start position:0% +including in terms of like peer effects +um people do all sorts of things because + + align:start position:0% +um people do all sorts of things because + + + align:start position:0% +um people do all sorts of things because +other people think + + align:start position:0% +other people think + + + align:start position:0% +other people think +that's cool but it's not necessarily + + align:start position:0% +that's cool but it's not necessarily + + + align:start position:0% +that's cool but it's not necessarily +what's best for + + align:start position:0% +what's best for + + + align:start position:0% +what's best for +them if they had to choose on their own + + align:start position:0% +them if they had to choose on their own + + + align:start position:0% +them if they had to choose on their own +okay great so let me stop here there's a + + align:start position:0% +okay great so let me stop here there's a + + + align:start position:0% +okay great so let me stop here there's a +lot of other examples that we can come + + align:start position:0% +lot of other examples that we can come + + + align:start position:0% +lot of other examples that we can come +up with + + align:start position:0% +up with + + + align:start position:0% +up with +i have a few here so one is sort of + + align:start position:0% +i have a few here so one is sort of + + + align:start position:0% +i have a few here so one is sort of +limited self-control that's one of my + + align:start position:0% +limited self-control that's one of my + + + align:start position:0% +limited self-control that's one of my +favorite pictures about + + align:start position:0% +favorite pictures about + + + align:start position:0% +favorite pictures about +a gym attendance where you say well uh + + align:start position:0% +a gym attendance where you say well uh + + + align:start position:0% +a gym attendance where you say well uh +you know they seem to be people have + + align:start position:0% +you know they seem to be people have + + + align:start position:0% +you know they seem to be people have +preferences for going to the gym + + align:start position:0% +preferences for going to the gym + + + align:start position:0% +preferences for going to the gym +um but then you know there's an + + align:start position:0% +um but then you know there's an + + + align:start position:0% +um but then you know there's an +escalator um and people like you know + + align:start position:0% +escalator um and people like you know + + + align:start position:0% +escalator um and people like you know +not working out so much so in some sense + + align:start position:0% +not working out so much so in some sense + + + align:start position:0% +not working out so much so in some sense +uh something is is perhaps um a miss + + align:start position:0% +uh something is is perhaps um a miss + + + align:start position:0% +uh something is is perhaps um a miss +here when you look at sort of + + align:start position:0% +here when you look at sort of + + + align:start position:0% +here when you look at sort of +i mean this is one of my favorite things + + align:start position:0% +i mean this is one of my favorite things + + + align:start position:0% +i mean this is one of my favorite things +to do is like in or not just not quite + + align:start position:0% +to do is like in or not just not quite + + + align:start position:0% +to do is like in or not just not quite +as + + align:start position:0% +as + + + align:start position:0% +as +it's a it's a fun thing to do i mean one + + align:start position:0% +it's a it's a fun thing to do i mean one + + + align:start position:0% +it's a it's a fun thing to do i mean one +of my favorite things um + + align:start position:0% +of my favorite things um + + + align:start position:0% +of my favorite things um +uh um uh uh when you sort of google um + + align:start position:0% +uh um uh uh when you sort of google um + + + align:start position:0% +uh um uh uh when you sort of google um +uh terms and this is um calories or + + align:start position:0% +uh terms and this is um calories or + + + align:start position:0% +uh terms and this is um calories or +weight watchers or the like + + align:start position:0% +weight watchers or the like + + + align:start position:0% +weight watchers or the like +where you say well what is people's + + align:start position:0% +where you say well what is people's + + + align:start position:0% +where you say well what is people's +interest in googling those kinds of + + align:start position:0% +interest in googling those kinds of + + + align:start position:0% +interest in googling those kinds of +terms + + align:start position:0% +terms + + + align:start position:0% +terms +over the course of a year and as you can + + align:start position:0% +over the course of a year and as you can + + + align:start position:0% +over the course of a year and as you can +imagine what you see are these spikes + + align:start position:0% +imagine what you see are these spikes + + + align:start position:0% +imagine what you see are these spikes +are essentially + + align:start position:0% +are essentially + + + align:start position:0% +are essentially +january 1st people start sort of like + + align:start position:0% +january 1st people start sort of like + + + align:start position:0% +january 1st people start sort of like +googling calories they like start + + align:start position:0% +googling calories they like start + + + align:start position:0% +googling calories they like start +googling weight watchers and so on and + + align:start position:0% +googling weight watchers and so on and + + + align:start position:0% +googling weight watchers and so on and +so forth + + align:start position:0% +so forth + + + align:start position:0% +so forth +and now of course you can sort of think + + align:start position:0% +and now of course you can sort of think + + + align:start position:0% +and now of course you can sort of think +about some models that sort of can + + align:start position:0% +about some models that sort of can + + + align:start position:0% +about some models that sort of can +rationalize + + align:start position:0% +rationalize + + + align:start position:0% +rationalize +in some sense in saying like well + + align:start position:0% +in some sense in saying like well + + + align:start position:0% +in some sense in saying like well +january is just a good way to start a + + align:start position:0% +january is just a good way to start a + + + align:start position:0% +january is just a good way to start a +a diet and so on but you know really the + + align:start position:0% +a diet and so on but you know really the + + + align:start position:0% +a diet and so on but you know really the +the right thing to do is sort of people + + align:start position:0% +the right thing to do is sort of people + + + align:start position:0% +the right thing to do is sort of people +and january 1st they have all the best + + align:start position:0% +and january 1st they have all the best + + + align:start position:0% +and january 1st they have all the best +of it + + align:start position:0% +of it + + + align:start position:0% +of it +intentions to lose weight uh uh eat + + align:start position:0% +intentions to lose weight uh uh eat + + + align:start position:0% +intentions to lose weight uh uh eat +healthier um + + align:start position:0% +healthier um + + + align:start position:0% +healthier um +exercise more and so on and so forth and + + align:start position:0% +exercise more and so on and so forth and + + + align:start position:0% +exercise more and so on and so forth and +then you know um + + align:start position:0% +then you know um + + + align:start position:0% +then you know um +uh the year starts the semester um + + align:start position:0% +uh the year starts the semester um + + + align:start position:0% +uh the year starts the semester um +happens and so on and so forth + + align:start position:0% +happens and so on and so forth + + + align:start position:0% +happens and so on and so forth +and the good attention sort of like um a + + align:start position:0% +and the good attention sort of like um a + + + align:start position:0% +and the good attention sort of like um a +fade away which is essentially as + + align:start position:0% +fade away which is essentially as + + + align:start position:0% +fade away which is essentially as +um limited self-control um + + align:start position:0% +um limited self-control um + + + align:start position:0% +um limited self-control um +there's some interesting things about + + align:start position:0% +there's some interesting things about + + + align:start position:0% +there's some interesting things about +demand for information especially when + + align:start position:0% +demand for information especially when + + + align:start position:0% +demand for information especially when +it comes to + + align:start position:0% +it comes to + + + align:start position:0% +it comes to +health you know every time i ask this + + align:start position:0% +health you know every time i ask this + + + align:start position:0% +health you know every time i ask this +um and i've taught this class a few + + align:start position:0% +um and i've taught this class a few + + + align:start position:0% +um and i've taught this class a few +years + + align:start position:0% +years + + + align:start position:0% +years +so far every time i ask this i should + + align:start position:0% +so far every time i ask this i should + + + align:start position:0% +so far every time i ask this i should +have realized how old i am who knows dr + + align:start position:0% +have realized how old i am who knows dr + + + align:start position:0% +have realized how old i am who knows dr +house + + align:start position:0% +house + + + align:start position:0% +house +oh not bad so can anybody explain to me + + align:start position:0% +oh not bad so can anybody explain to me + + + align:start position:0% +oh not bad so can anybody explain to me +13 and dr house and what is sort of + + align:start position:0% +13 and dr house and what is sort of + + + align:start position:0% +13 and dr house and what is sort of +their deal and what does this have to do + + align:start position:0% +their deal and what does this have to do + + + align:start position:0% +their deal and what does this have to do +with demand for information + + align:start position:0% + + + + align:start position:0% + +so who's 13 or what is her health issues + + align:start position:0% +so who's 13 or what is her health issues + + + align:start position:0% +so who's 13 or what is her health issues +she's got like i think yes she has + + align:start position:0% +she's got like i think yes she has + + + align:start position:0% +she's got like i think yes she has +huntington's yes right so + + align:start position:0% +huntington's yes right so + + + align:start position:0% +huntington's yes right so +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +right so she has a disease which is + + align:start position:0% +right so she has a disease which is + + + align:start position:0% +right so she has a disease which is +called huntington's disease which we'll + + align:start position:0% +called huntington's disease which we'll + + + align:start position:0% +called huntington's disease which we'll +also + + align:start position:0% +also + + + align:start position:0% +also +talk about more in the class which + + align:start position:0% +talk about more in the class which + + + align:start position:0% +talk about more in the class which +essentially is a brain disease + + align:start position:0% +essentially is a brain disease + + + align:start position:0% +essentially is a brain disease +where over time your brain more or less + + align:start position:0% +where over time your brain more or less + + + align:start position:0% +where over time your brain more or less +degenerates and that's a + + align:start position:0% +degenerates and that's a + + + align:start position:0% +degenerates and that's a +it's a really a bad condition and uh + + align:start position:0% +it's a really a bad condition and uh + + + align:start position:0% +it's a really a bad condition and uh +where like at age 40 50 that manifests + + align:start position:0% +where like at age 40 50 that manifests + + + align:start position:0% +where like at age 40 50 that manifests +and + + align:start position:0% +and + + + align:start position:0% +and +it's a very serious condition it's a + + align:start position:0% +it's a very serious condition it's a + + + align:start position:0% +it's a very serious condition it's a +genetic disease in the + + align:start position:0% +genetic disease in the + + + align:start position:0% +genetic disease in the +in the sense that like if your parents + + align:start position:0% +in the sense that like if your parents + + + align:start position:0% +in the sense that like if your parents +have that disease the chance of you + + align:start position:0% +have that disease the chance of you + + + align:start position:0% +have that disease the chance of you +having it is way way higher than + + align:start position:0% +having it is way way higher than + + + align:start position:0% +having it is way way higher than +in the general population uh there's a + + align:start position:0% +in the general population uh there's a + + + align:start position:0% +in the general population uh there's a +test for it but there's no cure + + align:start position:0% +test for it but there's no cure + + + align:start position:0% +test for it but there's no cure +so now um the dilemma and the show then + + align:start position:0% +so now um the dilemma and the show then + + + align:start position:0% +so now um the dilemma and the show then +comes where + + align:start position:0% +comes where + + + align:start position:0% +comes where +uh she essentially is thinking about + + align:start position:0% +uh she essentially is thinking about + + + align:start position:0% +uh she essentially is thinking about +getting tested + + align:start position:0% +getting tested + + + align:start position:0% +getting tested +and dr house who's in some ways very + + align:start position:0% +and dr house who's in some ways very + + + align:start position:0% +and dr house who's in some ways very +rational and others not so much + + align:start position:0% +rational and others not so much + + + align:start position:0% +rational and others not so much +essentially encourages her to test or + + align:start position:0% +essentially encourages her to test or + + + align:start position:0% +essentially encourages her to test or +get that test + + align:start position:0% +get that test + + + align:start position:0% +get that test +and any rational model would say well + + align:start position:0% +and any rational model would say well + + + align:start position:0% +and any rational model would say well +you should really get that + + align:start position:0% +you should really get that + + + align:start position:0% +you should really get that +or any sort of neoclassical model would + + align:start position:0% +or any sort of neoclassical model would + + + align:start position:0% +or any sort of neoclassical model would +say you should get that test why why + + align:start position:0% +say you should get that test why why + + + align:start position:0% +say you should get that test why why +should you get the test + + align:start position:0% +should you get the test + + + align:start position:0% +should you get the test +why is that helpful and what's that + + align:start position:0% +why is that helpful and what's that + + + align:start position:0% +why is that helpful and what's that +health information helpful for + + align:start position:0% + + + + align:start position:0% + +right exactly you would say information + + align:start position:0% +right exactly you would say information + + + align:start position:0% +right exactly you would say information +is good why is information good because + + align:start position:0% +is good why is information good because + + + align:start position:0% +is good why is information good because +there's lots of important choices that + + align:start position:0% +there's lots of important choices that + + + align:start position:0% +there's lots of important choices that +you might make + + align:start position:0% +you might make + + + align:start position:0% +you might make +that depend on that information you + + align:start position:0% +that depend on that information you + + + align:start position:0% +that depend on that information you +might think about like how much money + + align:start position:0% +might think about like how much money + + + align:start position:0% +might think about like how much money +you want to save you think about like + + align:start position:0% +you want to save you think about like + + + align:start position:0% +you want to save you think about like +your choices + + align:start position:0% +your choices + + + align:start position:0% +your choices +about taking vacation about + + align:start position:0% +about taking vacation about + + + align:start position:0% +about taking vacation about +career choices about partner choices + + align:start position:0% +career choices about partner choices + + + align:start position:0% +career choices about partner choices +about having children + + align:start position:0% +about having children + + + align:start position:0% +about having children +all sorts of issues about health + + align:start position:0% +all sorts of issues about health + + + align:start position:0% +all sorts of issues about health +behaviors you might sort of take better + + align:start position:0% +behaviors you might sort of take better + + + align:start position:0% +behaviors you might sort of take better +care of yourself + + align:start position:0% +care of yourself + + + align:start position:0% +care of yourself +there's all sorts of really important + + align:start position:0% +there's all sorts of really important + + + align:start position:0% +there's all sorts of really important +decision that might hinge on the fact + + align:start position:0% +decision that might hinge on the fact + + + align:start position:0% +decision that might hinge on the fact +like + + align:start position:0% +like + + + align:start position:0% +like +your life will be dramatically different + + align:start position:0% +your life will be dramatically different + + + align:start position:0% +your life will be dramatically different +whether you have huntington's disease + + align:start position:0% +whether you have huntington's disease + + + align:start position:0% +whether you have huntington's disease +or not now 13 does not want to i think + + align:start position:0% +or not now 13 does not want to i think + + + align:start position:0% +or not now 13 does not want to i think +she actually does the test and then + + align:start position:0% +she actually does the test and then + + + align:start position:0% +she actually does the test and then +doesn't want to see the result + + align:start position:0% +doesn't want to see the result + + + align:start position:0% +doesn't want to see the result +and why is that yes + + align:start position:0% + + + + align:start position:0% + +and so that's one view to view that i + + align:start position:0% +and so that's one view to view that i + + + align:start position:0% +and so that's one view to view that i +think you know in some things as i said + + align:start position:0% +think you know in some things as i said + + + align:start position:0% +think you know in some things as i said +you may could make other decisions like + + align:start position:0% +you may could make other decisions like + + + align:start position:0% +you may could make other decisions like +economic choices you could save more you + + align:start position:0% +economic choices you could save more you + + + align:start position:0% +economic choices you could save more you +could see the doctor more you could + + align:start position:0% +could see the doctor more you could + + + align:start position:0% +could see the doctor more you could +go more on vacations or whatever do fun + + align:start position:0% +go more on vacations or whatever do fun + + + align:start position:0% +go more on vacations or whatever do fun +things in life but you could say well + + align:start position:0% +things in life but you could say well + + + align:start position:0% +things in life but you could say well +maybe that's not that important but the + + align:start position:0% +maybe that's not that important but the + + + align:start position:0% +maybe that's not that important but the +neoclassical or the the classical + + align:start position:0% +neoclassical or the the classical + + + align:start position:0% +neoclassical or the the classical +economics model + + align:start position:0% +economics model + + + align:start position:0% +economics model +would still argue that you should get + + align:start position:0% +would still argue that you should get + + + align:start position:0% +would still argue that you should get +that information it wouldn't hurt you + + align:start position:0% +that information it wouldn't hurt you + + + align:start position:0% +that information it wouldn't hurt you +you wouldn't want to refuse it + + align:start position:0% +you wouldn't want to refuse it + + + align:start position:0% +you wouldn't want to refuse it +so why is she but why is she refusing it + + align:start position:0% +so why is she but why is she refusing it + + + align:start position:0% +so why is she but why is she refusing it +yes i think maybe she doesn't want to + + align:start position:0% +yes i think maybe she doesn't want to + + + align:start position:0% +yes i think maybe she doesn't want to +leave the rest of her life + + align:start position:0% +leave the rest of her life + + + align:start position:0% +leave the rest of her life +exactly so she essentially derives + + align:start position:0% +exactly so she essentially derives + + + align:start position:0% +exactly so she essentially derives +utility from + + align:start position:0% +utility from + + + align:start position:0% +utility from +information if you want from her beliefs + + align:start position:0% +information if you want from her beliefs + + + align:start position:0% +information if you want from her beliefs +she likes to sort of pretend to herself + + align:start position:0% +she likes to sort of pretend to herself + + + align:start position:0% +she likes to sort of pretend to herself +that she's healthy or like the chance of + + align:start position:0% +that she's healthy or like the chance of + + + align:start position:0% +that she's healthy or like the chance of +her being healthy is very high + + align:start position:0% +her being healthy is very high + + + align:start position:0% +her being healthy is very high +now under some assumptions you might + + align:start position:0% +now under some assumptions you might + + + align:start position:0% +now under some assumptions you might +want to not get tested and sort of see + + align:start position:0% +want to not get tested and sort of see + + + align:start position:0% +want to not get tested and sort of see +the results + + align:start position:0% +the results + + + align:start position:0% +the results +of that test because once you have the + + align:start position:0% +of that test because once you have the + + + align:start position:0% +of that test because once you have the +test it's very hard to pretend + + align:start position:0% +test it's very hard to pretend + + + align:start position:0% +test it's very hard to pretend +if it's positive it's very hard to + + align:start position:0% +if it's positive it's very hard to + + + align:start position:0% +if it's positive it's very hard to +pretend to yourself uh + + align:start position:0% +pretend to yourself uh + + + align:start position:0% +pretend to yourself uh +uh uh that you're healthy because + + align:start position:0% +uh uh that you're healthy because + + + align:start position:0% +uh uh that you're healthy because +there's a hard test saying that + + align:start position:0% +there's a hard test saying that + + + align:start position:0% +there's a hard test saying that +um before the test you can still sort of + + align:start position:0% +um before the test you can still sort of + + + align:start position:0% +um before the test you can still sort of +think like try to forget about it and + + align:start position:0% +think like try to forget about it and + + + align:start position:0% +think like try to forget about it and +try to sort of live a happy life + + align:start position:0% +try to sort of live a happy life + + + align:start position:0% +try to sort of live a happy life +sort of until the symptoms set in + + align:start position:0% +sort of until the symptoms set in + + + align:start position:0% +sort of until the symptoms set in +but that's a clear violation of the + + align:start position:0% +but that's a clear violation of the + + + align:start position:0% +but that's a clear violation of the +classical model of the assumptions that + + align:start position:0% +classical model of the assumptions that + + + align:start position:0% +classical model of the assumptions that +i was showing you + + align:start position:0% +i was showing you + + + align:start position:0% +i was showing you +above + + align:start position:0% + + + + align:start position:0% + +the next part is uh default effects so + + align:start position:0% +the next part is uh default effects so + + + align:start position:0% +the next part is uh default effects so +what i'm showing here here is the + + align:start position:0% +what i'm showing here here is the + + + align:start position:0% +what i'm showing here here is the +fraction of organ + + align:start position:0% +fraction of organ + + + align:start position:0% +fraction of organ +donors by country and type of default + + align:start position:0% +donors by country and type of default + + + align:start position:0% +donors by country and type of default +there's uh + + align:start position:0% +there's uh + + + align:start position:0% +there's uh +two types of defaults um often for organ + + align:start position:0% +two types of defaults um often for organ + + + align:start position:0% +two types of defaults um often for organ +donations + + align:start position:0% +donations + + + align:start position:0% +donations +this is from a few years ago but i think + + align:start position:0% +this is from a few years ago but i think + + + align:start position:0% +this is from a few years ago but i think +overall things have not changed that + + align:start position:0% +overall things have not changed that + + + align:start position:0% +overall things have not changed that +much um there's opt-in versus + + align:start position:0% +much um there's opt-in versus + + + align:start position:0% +much um there's opt-in versus +opt-out so in the countries on the left + + align:start position:0% +opt-out so in the countries on the left + + + align:start position:0% +opt-out so in the countries on the left +essentially you have an opt-in policy in + + align:start position:0% +essentially you have an opt-in policy in + + + align:start position:0% +essentially you have an opt-in policy in +a sense like if you don't do anything + + align:start position:0% +a sense like if you don't do anything + + + align:start position:0% +a sense like if you don't do anything +you're not an organ donor + + align:start position:0% +you're not an organ donor + + + align:start position:0% +you're not an organ donor +so you have to like actively say in some + + align:start position:0% +so you have to like actively say in some + + + align:start position:0% +so you have to like actively say in some +form or some form of like declaration + + align:start position:0% +form or some form of like declaration + + + align:start position:0% +form or some form of like declaration +that you want to be + + align:start position:0% +that you want to be + + + align:start position:0% +that you want to be +an organ donor on the right there's like + + align:start position:0% +an organ donor on the right there's like + + + align:start position:0% +an organ donor on the right there's like +opt + + align:start position:0% +opt + + + align:start position:0% +opt +out policies which means essentially if + + align:start position:0% +out policies which means essentially if + + + align:start position:0% +out policies which means essentially if +you don't do anything you'll be + + align:start position:0% +you don't do anything you'll be + + + align:start position:0% +you don't do anything you'll be +automatically + + align:start position:0% +automatically + + + align:start position:0% +automatically +registered or viewed as an organ donor + + align:start position:0% +registered or viewed as an organ donor + + + align:start position:0% +registered or viewed as an organ donor +you can opt + + align:start position:0% +you can opt + + + align:start position:0% +you can opt +out but only um uh only if you do so + + align:start position:0% +out but only um uh only if you do so + + + align:start position:0% +out but only um uh only if you do so +you'll actually be opted out otherwise + + align:start position:0% +you'll actually be opted out otherwise + + + align:start position:0% +you'll actually be opted out otherwise +if there's an accident in the lake + + align:start position:0% +if there's an accident in the lake + + + align:start position:0% +if there's an accident in the lake +you'll be viewed as an organ donor + + align:start position:0% +you'll be viewed as an organ donor + + + align:start position:0% +you'll be viewed as an organ donor +now what's weird about this graph or why + + align:start position:0% +now what's weird about this graph or why + + + align:start position:0% +now what's weird about this graph or why +is this sort of uh + + align:start position:0% +is this sort of uh + + + align:start position:0% +is this sort of uh +potentially a violation of the + + align:start position:0% +potentially a violation of the + + + align:start position:0% +potentially a violation of the +neoclassical or the typical economics + + align:start position:0% +neoclassical or the typical economics + + + align:start position:0% +neoclassical or the typical economics +assumptions + + align:start position:0% + + + + align:start position:0% + +yes the + + align:start position:0% +yes the + + + align:start position:0% +yes the +people have the same preference of + + align:start position:0% +people have the same preference of + + + align:start position:0% +people have the same preference of +whether they want to opt-in or opt-out + + align:start position:0% +whether they want to opt-in or opt-out + + + align:start position:0% +whether they want to opt-in or opt-out +that everyone should have this would be + + align:start position:0% +that everyone should have this would be + + + align:start position:0% +that everyone should have this would be +the same proportion across + + align:start position:0% +the same proportion across + + + align:start position:0% +the same proportion across +but the difference is that um the effort + + align:start position:0% +but the difference is that um the effort + + + align:start position:0% +but the difference is that um the effort +required to make that change or the + + align:start position:0% +required to make that change or the + + + align:start position:0% +required to make that change or the +difference the lack of indifference + + align:start position:0% +difference the lack of indifference + + + align:start position:0% +difference the lack of indifference +causes there to be the imbalance between + + align:start position:0% +causes there to be the imbalance between + + + align:start position:0% +causes there to be the imbalance between +the opt-out and the opt-in + + align:start position:0% +the opt-out and the opt-in + + + align:start position:0% +the opt-out and the opt-in +right exactly so um some people on uh + + align:start position:0% +right exactly so um some people on uh + + + align:start position:0% +right exactly so um some people on uh +you know + + align:start position:0% +you know + + + align:start position:0% +you know +don't want to get in trouble but some + + align:start position:0% +don't want to get in trouble but some + + + align:start position:0% +don't want to get in trouble but some +people argue germany and austria is + + align:start position:0% +people argue germany and austria is + + + align:start position:0% +people argue germany and austria is +actually not that different so i'm + + align:start position:0% +actually not that different so i'm + + + align:start position:0% +actually not that different so i'm +german so you know some austrians might + + align:start position:0% +german so you know some austrians might + + + align:start position:0% +german so you know some austrians might +disagree but you would say you know + + align:start position:0% +disagree but you would say you know + + + align:start position:0% +disagree but you would say you know +overall germans and austrians are not + + align:start position:0% +overall germans and austrians are not + + + align:start position:0% +overall germans and austrians are not +that different overall and you think you + + align:start position:0% +that different overall and you think you + + + align:start position:0% +that different overall and you think you +know their preferences in particular + + align:start position:0% +know their preferences in particular + + + align:start position:0% +know their preferences in particular +they might be different but their + + align:start position:0% +they might be different but their + + + align:start position:0% +they might be different but their +preferences for organ donations + + align:start position:0% +preferences for organ donations + + + align:start position:0% +preferences for organ donations +are probably pretty similar across those + + align:start position:0% +are probably pretty similar across those + + + align:start position:0% +are probably pretty similar across those +two countries which is a reasonable + + align:start position:0% +two countries which is a reasonable + + + align:start position:0% +two countries which is a reasonable +assumption + + align:start position:0% +assumption + + + align:start position:0% +assumption +second lots of people care a lot about + + align:start position:0% +second lots of people care a lot about + + + align:start position:0% +second lots of people care a lot about +what happens to them after they die + + align:start position:0% +what happens to them after they die + + + align:start position:0% +what happens to them after they die +right so they for whatever reasons + + align:start position:0% +right so they for whatever reasons + + + align:start position:0% +right so they for whatever reasons +religious or others they might actually + + align:start position:0% +religious or others they might actually + + + align:start position:0% +religious or others they might actually +care a lot about at the end of the day + + align:start position:0% +care a lot about at the end of the day + + + align:start position:0% +care a lot about at the end of the day +um uh what happens to their body and so + + align:start position:0% +um uh what happens to their body and so + + + align:start position:0% +um uh what happens to their body and so +on and that's obviously their choice + + align:start position:0% +on and that's obviously their choice + + + align:start position:0% +on and that's obviously their choice +um to make now if you assume those two + + align:start position:0% +um to make now if you assume those two + + + align:start position:0% +um to make now if you assume those two +things + + align:start position:0% +things + + + align:start position:0% +things +then it's very hard to reconcile this + + align:start position:0% +then it's very hard to reconcile this + + + align:start position:0% +then it's very hard to reconcile this +this picture + + align:start position:0% +this picture + + + align:start position:0% +this picture +because essentially um the opt in and + + align:start position:0% +because essentially um the opt in and + + + align:start position:0% +because essentially um the opt in and +out out is a very small change to make + + align:start position:0% +out out is a very small change to make + + + align:start position:0% +out out is a very small change to make +it's very um simple and easy to do you + + align:start position:0% +it's very um simple and easy to do you + + + align:start position:0% +it's very um simple and easy to do you +just have to like fill out some form + + align:start position:0% +just have to like fill out some form + + + align:start position:0% +just have to like fill out some form +maybe it takes you an hour maybe two you + + align:start position:0% +maybe it takes you an hour maybe two you + + + align:start position:0% +maybe it takes you an hour maybe two you +have to maybe go to some office or the + + align:start position:0% +have to maybe go to some office or the + + + align:start position:0% +have to maybe go to some office or the +like + + align:start position:0% +like + + + align:start position:0% +like +but if you really care you could easily + + align:start position:0% +but if you really care you could easily + + + align:start position:0% +but if you really care you could easily +do it + + align:start position:0% +do it + + + align:start position:0% +do it +yet you see huge differences in outcome + + align:start position:0% +yet you see huge differences in outcome + + + align:start position:0% +yet you see huge differences in outcome +based on this very simple + + align:start position:0% +based on this very simple + + + align:start position:0% +based on this very simple +um small change which it's very hard to + + align:start position:0% +um small change which it's very hard to + + + align:start position:0% +um small change which it's very hard to +model a right on a model that sort of + + align:start position:0% +model a right on a model that sort of + + + align:start position:0% +model a right on a model that sort of +rationalizes this behavior + + align:start position:0% +rationalizes this behavior + + + align:start position:0% +rationalizes this behavior +so somehow the default sort of the way + + align:start position:0% +so somehow the default sort of the way + + + align:start position:0% +so somehow the default sort of the way +in which the decision is presented + + align:start position:0% +in which the decision is presented + + + align:start position:0% +in which the decision is presented +seems to really affect people's behavior + + align:start position:0% +seems to really affect people's behavior + + + align:start position:0% +seems to really affect people's behavior +in a fundamental + + align:start position:0% +in a fundamental + + + align:start position:0% +in a fundamental +way + + align:start position:0% + + + + align:start position:0% + +okay next one is glow caps this is like + + align:start position:0% +okay next one is glow caps this is like + + + align:start position:0% +okay next one is glow caps this is like +a + + align:start position:0% +a + + + align:start position:0% +a +help for people to take their medication + + align:start position:0% +help for people to take their medication + + + align:start position:0% +help for people to take their medication +in particular for the elderly + + align:start position:0% +in particular for the elderly + + + align:start position:0% +in particular for the elderly +which essentially is a reminder um uh + + align:start position:0% +which essentially is a reminder um uh + + + align:start position:0% +which essentially is a reminder um uh +for people you can sort of program this + + align:start position:0% +for people you can sort of program this + + + align:start position:0% +for people you can sort of program this +in certain ways + + align:start position:0% +in certain ways + + + align:start position:0% +in certain ways +like every day or every few hours um a + + align:start position:0% +like every day or every few hours um a + + + align:start position:0% +like every day or every few hours um a +glow cap + + align:start position:0% +glow cap + + + align:start position:0% +glow cap +starts either sort of making sounds or + + align:start position:0% +starts either sort of making sounds or + + + align:start position:0% +starts either sort of making sounds or +like starts blinking and the like + + align:start position:0% +like starts blinking and the like + + + align:start position:0% +like starts blinking and the like +and gets you to take your medication and + + align:start position:0% +and gets you to take your medication and + + + align:start position:0% +and gets you to take your medication and +it's a very sort of simple proof of + + align:start position:0% +it's a very sort of simple proof of + + + align:start position:0% +it's a very sort of simple proof of +concept that you know reminders are + + align:start position:0% +concept that you know reminders are + + + align:start position:0% +concept that you know reminders are +important and can save people's lives + + align:start position:0% +important and can save people's lives + + + align:start position:0% +important and can save people's lives +and people have done studies on that and + + align:start position:0% +and people have done studies on that and + + + align:start position:0% +and people have done studies on that and +so on + + align:start position:0% +so on + + + align:start position:0% +so on +but essentially it's a very simple proof + + align:start position:0% +but essentially it's a very simple proof + + + align:start position:0% +but essentially it's a very simple proof +of concept that memory is limited + + align:start position:0% +of concept that memory is limited + + + align:start position:0% +of concept that memory is limited +right if your memory was perfect if you + + align:start position:0% +right if your memory was perfect if you + + + align:start position:0% +right if your memory was perfect if you +could remember everything if you sort of + + align:start position:0% +could remember everything if you sort of + + + align:start position:0% +could remember everything if you sort of +had all sorts of if you're a perfect + + align:start position:0% +had all sorts of if you're a perfect + + + align:start position:0% +had all sorts of if you're a perfect +information processor + + align:start position:0% +information processor + + + align:start position:0% +information processor +you would not forget about your + + align:start position:0% +you would not forget about your + + + align:start position:0% +you would not forget about your +medication especially if it's important + + align:start position:0% +medication especially if it's important + + + align:start position:0% +medication especially if it's important +especially if it's medication + + align:start position:0% +especially if it's medication + + + align:start position:0% +especially if it's medication +uh that potentially saves your lives yet + + align:start position:0% +uh that potentially saves your lives yet + + + align:start position:0% +uh that potentially saves your lives yet +you know we see that people's demand + + align:start position:0% +you know we see that people's demand + + + align:start position:0% +you know we see that people's demand +people's uh uh medication usage um + + align:start position:0% +people's uh uh medication usage um + + + align:start position:0% +people's uh uh medication usage um +is uh strongly affected by sort of types + + align:start position:0% +is uh strongly affected by sort of types + + + align:start position:0% +is uh strongly affected by sort of types +of policies or products + + align:start position:0% +of policies or products + + + align:start position:0% +of policies or products +um that can help people uh remember so + + align:start position:0% +um that can help people uh remember so + + + align:start position:0% +um that can help people uh remember so +that's essentially a rejection of um + + align:start position:0% +that's essentially a rejection of um + + + align:start position:0% +that's essentially a rejection of um +perfect memory + + align:start position:0% +perfect memory + + + align:start position:0% +perfect memory +um next one is charity so if you think + + align:start position:0% +um next one is charity so if you think + + + align:start position:0% +um next one is charity so if you think +about you know um + + align:start position:0% +about you know um + + + align:start position:0% +about you know um +people in all sorts of ways seem to care + + align:start position:0% +people in all sorts of ways seem to care + + + align:start position:0% +people in all sorts of ways seem to care +about others in the sense of like just + + align:start position:0% +about others in the sense of like just + + + align:start position:0% +about others in the sense of like just +giving + + align:start position:0% +giving + + + align:start position:0% +giving +uh money uh here's one charity that's + + align:start position:0% +uh money uh here's one charity that's + + + align:start position:0% +uh money uh here's one charity that's +called gift directly which is + + align:start position:0% +called gift directly which is + + + align:start position:0% +called gift directly which is +a very nice charity in a sense that like + + align:start position:0% +a very nice charity in a sense that like + + + align:start position:0% +a very nice charity in a sense that like +what it does essentially is + + align:start position:0% +what it does essentially is + + + align:start position:0% +what it does essentially is +a very simple way of helping the poor by + + align:start position:0% +a very simple way of helping the poor by + + + align:start position:0% +a very simple way of helping the poor by +just directly transferring money + + align:start position:0% +just directly transferring money + + + align:start position:0% +just directly transferring money +to poorer countries so on the right you + + align:start position:0% +to poorer countries so on the right you + + + align:start position:0% +to poorer countries so on the right you +see an actual recipient from + + align:start position:0% +see an actual recipient from + + + align:start position:0% +see an actual recipient from +give directly that person has a phone + + align:start position:0% +give directly that person has a phone + + + align:start position:0% +give directly that person has a phone +they're sort of a mobile + + align:start position:0% +they're sort of a mobile + + + align:start position:0% +they're sort of a mobile +phone based uh transfers where + + align:start position:0% +phone based uh transfers where + + + align:start position:0% +phone based uh transfers where +essentially you can send money to people + + align:start position:0% +essentially you can send money to people + + + align:start position:0% +essentially you can send money to people +with mobile phones + + align:start position:0% +with mobile phones + + + align:start position:0% +with mobile phones +so if you decided now to give hundred + + align:start position:0% +so if you decided now to give hundred + + + align:start position:0% +so if you decided now to give hundred +dollars um + + align:start position:0% +dollars um + + + align:start position:0% +dollars um +to that person it could be that person + + align:start position:0% +to that person it could be that person + + + align:start position:0% +to that person it could be that person +or a similar person + + align:start position:0% +or a similar person + + + align:start position:0% +or a similar person +uh 95 of those or 90 of those dollars + + align:start position:0% +uh 95 of those or 90 of those dollars + + + align:start position:0% +uh 95 of those or 90 of those dollars +would then in fact arrive at the phone + + align:start position:0% +would then in fact arrive at the phone + + + align:start position:0% +would then in fact arrive at the phone +a cell phone of that person now um + + align:start position:0% +a cell phone of that person now um + + + align:start position:0% +a cell phone of that person now um +why are people doing this presumably + + align:start position:0% +why are people doing this presumably + + + align:start position:0% +why are people doing this presumably +because they care about others one way + + align:start position:0% +because they care about others one way + + + align:start position:0% +because they care about others one way +or the other + + align:start position:0% +or the other + + + align:start position:0% +or the other +um it could be either that you know in + + align:start position:0% +um it could be either that you know in + + + align:start position:0% +um it could be either that you know in +some sense that's part of the utility + + align:start position:0% +some sense that's part of the utility + + + align:start position:0% +some sense that's part of the utility +function just donating money to others + + align:start position:0% +function just donating money to others + + + align:start position:0% +function just donating money to others +makes you happier and that's essentially + + align:start position:0% +makes you happier and that's essentially + + + align:start position:0% +makes you happier and that's essentially +a way in which you improve your + + align:start position:0% +a way in which you improve your + + + align:start position:0% +a way in which you improve your +well-being you just have + + align:start position:0% +well-being you just have + + + align:start position:0% +well-being you just have +others well-being in your utility + + align:start position:0% +others well-being in your utility + + + align:start position:0% +others well-being in your utility +function or it could be things like what + + align:start position:0% +function or it could be things like what + + + align:start position:0% +function or it could be things like what +we said previously it could be like you + + align:start position:0% +we said previously it could be like you + + + align:start position:0% +we said previously it could be like you +sort of think it's like appropriate + + align:start position:0% +sort of think it's like appropriate + + + align:start position:0% +sort of think it's like appropriate +thing to do maybe other people's do it's + + align:start position:0% +thing to do maybe other people's do it's + + + align:start position:0% +thing to do maybe other people's do it's +like an important thing to do maybe you + + align:start position:0% +like an important thing to do maybe you + + + align:start position:0% +like an important thing to do maybe you +could tell your friends about it and so + + align:start position:0% +could tell your friends about it and so + + + align:start position:0% +could tell your friends about it and so +on and so forth + + align:start position:0% +on and so forth + + + align:start position:0% +on and so forth +but one way the other people give lots + + align:start position:0% +but one way the other people give lots + + + align:start position:0% +but one way the other people give lots +of money to charity which in some sense + + align:start position:0% +of money to charity which in some sense + + + align:start position:0% +of money to charity which in some sense +says one way or the other you must care + + align:start position:0% +says one way or the other you must care + + + align:start position:0% +says one way or the other you must care +about others + + align:start position:0% +about others + + + align:start position:0% +about others +overall so others are in your utility + + align:start position:0% +overall so others are in your utility + + + align:start position:0% +overall so others are in your utility +function + + align:start position:0% +function + + + align:start position:0% +function +so now attention um if you've seen this + + align:start position:0% +so now attention um if you've seen this + + + align:start position:0% +so now attention um if you've seen this +before um uh + + align:start position:0% +before um uh + + + align:start position:0% +before um uh +don't tell your friends about it here's + + align:start position:0% +don't tell your friends about it here's + + + align:start position:0% +don't tell your friends about it here's +a simple attention test that i want you + + align:start position:0% +a simple attention test that i want you + + + align:start position:0% +a simple attention test that i want you +to + + align:start position:0% +to + + + align:start position:0% +to +do what's interesting about this is in + + align:start position:0% +do what's interesting about this is in + + + align:start position:0% +do what's interesting about this is in +some ways like + + align:start position:0% +some ways like + + + align:start position:0% +some ways like +um you know you might have seen this + + align:start position:0% +um you know you might have seen this + + + align:start position:0% +um you know you might have seen this +before some of them may have she's seen + + align:start position:0% +before some of them may have she's seen + + + align:start position:0% +before some of them may have she's seen +the gorilla before + + align:start position:0% +the gorilla before + + + align:start position:0% +the gorilla before +uh who didn't see the gorilla it's okay + + align:start position:0% +uh who didn't see the gorilla it's okay + + + align:start position:0% +uh who didn't see the gorilla it's okay +i didn't see it either but something + + align:start position:0% +i didn't see it either but something + + + align:start position:0% +i didn't see it either but something +some people have seen it before that + + align:start position:0% +some people have seen it before that + + + align:start position:0% +some people have seen it before that +there's a bunch of experiments that + + align:start position:0% +there's a bunch of experiments that + + + align:start position:0% +there's a bunch of experiments that +people have done that essentially show + + align:start position:0% +people have done that essentially show + + + align:start position:0% +people have done that essentially show +that you know often + + align:start position:0% +that you know often + + + align:start position:0% +that you know often +a large fraction of people don't see + + align:start position:0% +a large fraction of people don't see + + + align:start position:0% +a large fraction of people don't see +this gorilla + + align:start position:0% +this gorilla + + + align:start position:0% +this gorilla +and there's various ways in which people + + align:start position:0% +and there's various ways in which people + + + align:start position:0% +and there's various ways in which people +do other types of experiments + + align:start position:0% +do other types of experiments + + + align:start position:0% +do other types of experiments +there's types of experiments where + + align:start position:0% +there's types of experiments where + + + align:start position:0% +there's types of experiments where +essentially people + + align:start position:0% +essentially people + + + align:start position:0% +essentially people +they go to like some bank teller the + + align:start position:0% +they go to like some bank teller the + + + align:start position:0% +they go to like some bank teller the +bank teller says i'm going to go away + + align:start position:0% +bank teller says i'm going to go away + + + align:start position:0% +bank teller says i'm going to go away +and then comes back and then there's a + + align:start position:0% +and then comes back and then there's a + + + align:start position:0% +and then comes back and then there's a +different person who comes back and + + align:start position:0% +different person who comes back and + + + align:start position:0% +different person who comes back and +people don't notice + + align:start position:0% +people don't notice + + + align:start position:0% +people don't notice +there's various versions of that and so + + align:start position:0% +there's various versions of that and so + + + align:start position:0% +there's various versions of that and so +what's interesting about this in some + + align:start position:0% +what's interesting about this in some + + + align:start position:0% +what's interesting about this in some +sense is + + align:start position:0% +sense is + + + align:start position:0% +sense is +so a it proves in some ways that + + align:start position:0% +so a it proves in some ways that + + + align:start position:0% +so a it proves in some ways that +attention is limited + + align:start position:0% +attention is limited + + + align:start position:0% +attention is limited +you just focus your attention on some + + align:start position:0% +you just focus your attention on some + + + align:start position:0% +you just focus your attention on some +things and not others + + align:start position:0% +things and not others + + + align:start position:0% +things and not others +and you might miss important things now + + align:start position:0% +and you might miss important things now + + + align:start position:0% +and you might miss important things now +that's okay in some ways there's sort of + + align:start position:0% +that's okay in some ways there's sort of + + + align:start position:0% +that's okay in some ways there's sort of +a version of that that says well + + align:start position:0% +a version of that that says well + + + align:start position:0% +a version of that that says well +it might be sort of like rational + + align:start position:0% +it might be sort of like rational + + + align:start position:0% +it might be sort of like rational +inattention in some sense you focus on + + align:start position:0% +inattention in some sense you focus on + + + align:start position:0% +inattention in some sense you focus on +the important things in life and you + + align:start position:0% +the important things in life and you + + + align:start position:0% +the important things in life and you +might miss some things and that's okay + + align:start position:0% +might miss some things and that's okay + + + align:start position:0% +might miss some things and that's okay +in some sense + + align:start position:0% +in some sense + + + align:start position:0% +in some sense +i ask you or the video asks you to count + + align:start position:0% +i ask you or the video asks you to count + + + align:start position:0% +i ask you or the video asks you to count +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +passes so in some sense the gorilla is + + align:start position:0% +passes so in some sense the gorilla is + + + align:start position:0% +passes so in some sense the gorilla is +irrelevant and that's true in this case + + align:start position:0% +irrelevant and that's true in this case + + + align:start position:0% +irrelevant and that's true in this case +but in many other cases people might + + align:start position:0% +but in many other cases people might + + + align:start position:0% +but in many other cases people might +sort of not rationally pay attention + + align:start position:0% +sort of not rationally pay attention + + + align:start position:0% +sort of not rationally pay attention +they might sort of miss + + align:start position:0% +they might sort of miss + + + align:start position:0% +they might sort of miss +some really important things in their + + align:start position:0% +some really important things in their + + + align:start position:0% +some really important things in their +lives in part because you know they're + + align:start position:0% +lives in part because you know they're + + + align:start position:0% +lives in part because you know they're +distracted and part because they don't + + align:start position:0% +distracted and part because they don't + + + align:start position:0% +distracted and part because they don't +want to + + align:start position:0% +want to + + + align:start position:0% +want to +pay attention and so on um and sort of + + align:start position:0% +pay attention and so on um and sort of + + + align:start position:0% +pay attention and so on um and sort of +some of the strand of behavioral + + align:start position:0% +some of the strand of behavioral + + + align:start position:0% +some of the strand of behavioral +economics which we'll talk about is sort + + align:start position:0% +economics which we'll talk about is sort + + + align:start position:0% +economics which we'll talk about is sort +of like + + align:start position:0% +of like + + + align:start position:0% +of like +when people do not pay attention and + + align:start position:0% +when people do not pay attention and + + + align:start position:0% +when people do not pay attention and +then make mistakes + + align:start position:0% +then make mistakes + + + align:start position:0% +then make mistakes +because of that + + align:start position:0% + + + + align:start position:0% + +okay so i could go on and on with lots + + align:start position:0% +okay so i could go on and on with lots + + + align:start position:0% +okay so i could go on and on with lots +of different examples but + + align:start position:0% +of different examples but + + + align:start position:0% +of different examples but +the bottom line here is that most + + align:start position:0% +the bottom line here is that most + + + align:start position:0% +the bottom line here is that most +researchers in psychology economics + + align:start position:0% +researchers in psychology economics + + + align:start position:0% +researchers in psychology economics +believe that the classical um model of + + align:start position:0% +believe that the classical um model of + + + align:start position:0% +believe that the classical um model of +behavior to the homo economics is too + + align:start position:0% +behavior to the homo economics is too + + + align:start position:0% +behavior to the homo economics is too +too extreme in various ways uh that that + + align:start position:0% +too extreme in various ways uh that that + + + align:start position:0% +too extreme in various ways uh that that +person is too selfish + + align:start position:0% +person is too selfish + + + align:start position:0% +person is too selfish +um too rational and too willful and um + + align:start position:0% +um too rational and too willful and um + + + align:start position:0% +um too rational and too willful and um +you know in some ways we want to kind of + + align:start position:0% +you know in some ways we want to kind of + + + align:start position:0% +you know in some ways we want to kind of +understand how relaxing some of these + + align:start position:0% +understand how relaxing some of these + + + align:start position:0% +understand how relaxing some of these +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +might make economic models more + + align:start position:0% +might make economic models more + + + align:start position:0% +might make economic models more +realistic now in some sense + + align:start position:0% +realistic now in some sense + + + align:start position:0% +realistic now in some sense +no economist would in fact argue that + + align:start position:0% +no economist would in fact argue that + + + align:start position:0% +no economist would in fact argue that +the assumptions of the standard models + + align:start position:0% +the assumptions of the standard models + + + align:start position:0% +the assumptions of the standard models +are exactly correct + + align:start position:0% +are exactly correct + + + align:start position:0% +are exactly correct +the questions are are these deviations + + align:start position:0% +the questions are are these deviations + + + align:start position:0% +the questions are are these deviations +important do they actually matter for + + align:start position:0% +important do they actually matter for + + + align:start position:0% +important do they actually matter for +something important + + align:start position:0% +something important + + + align:start position:0% +something important +in explaining people's behavior and you + + align:start position:0% +in explaining people's behavior and you + + + align:start position:0% +in explaining people's behavior and you +know which of those assumptions for + + align:start position:0% +know which of those assumptions for + + + align:start position:0% +know which of those assumptions for +deviations + + align:start position:0% +deviations + + + align:start position:0% +deviations +uh actually matter and that's kind of + + align:start position:0% +uh actually matter and that's kind of + + + align:start position:0% +uh actually matter and that's kind of +like the name of the the game here + + align:start position:0% +like the name of the the game here + + + align:start position:0% +like the name of the the game here +um in fact when you look at sort of like + + align:start position:0% +um in fact when you look at sort of like + + + align:start position:0% +um in fact when you look at sort of like +when you talk to cognitive + + align:start position:0% +when you talk to cognitive + + + align:start position:0% +when you talk to cognitive +scientists uh psychologists etc um + + align:start position:0% +scientists uh psychologists etc um + + + align:start position:0% +scientists uh psychologists etc um +they will tell you the world is full of + + align:start position:0% +they will tell you the world is full of + + + align:start position:0% +they will tell you the world is full of +uh cognitive biases and uh you + + align:start position:0% +uh cognitive biases and uh you + + + align:start position:0% +uh cognitive biases and uh you +might not be able to read this and + + align:start position:0% +might not be able to read this and + + + align:start position:0% +might not be able to read this and +that's kind of the point there's like so + + align:start position:0% +that's kind of the point there's like so + + + align:start position:0% +that's kind of the point there's like so +many different things in which we're + + align:start position:0% +many different things in which we're + + + align:start position:0% +many different things in which we're +biased in some sense every choice that + + align:start position:0% +biased in some sense every choice that + + + align:start position:0% +biased in some sense every choice that +we make or anything + + align:start position:0% +we make or anything + + + align:start position:0% +we make or anything +we do there's lots of biases that + + align:start position:0% +we do there's lots of biases that + + + align:start position:0% +we do there's lots of biases that +interfere with people's choices + + align:start position:0% +interfere with people's choices + + + align:start position:0% +interfere with people's choices +and almost any choice you can think of + + align:start position:0% +and almost any choice you can think of + + + align:start position:0% +and almost any choice you can think of +or any behavior they can think about + + align:start position:0% +or any behavior they can think about + + + align:start position:0% +or any behavior they can think about +there will be a psychology or other + + align:start position:0% +there will be a psychology or other + + + align:start position:0% +there will be a psychology or other +experiments showing that people do not + + align:start position:0% +experiments showing that people do not + + + align:start position:0% +experiments showing that people do not +uh behave perfectly now + + align:start position:0% +uh behave perfectly now + + + align:start position:0% +uh behave perfectly now +the key question then is which of those + + align:start position:0% +the key question then is which of those + + + align:start position:0% +the key question then is which of those +assumptions are are important or which + + align:start position:0% +assumptions are are important or which + + + align:start position:0% +assumptions are are important or which +of those assumptions + + align:start position:0% +of those assumptions + + + align:start position:0% +of those assumptions +violations of assumptions should we + + align:start position:0% +violations of assumptions should we + + + align:start position:0% +violations of assumptions should we +focus on and for that i want to step + + align:start position:0% +focus on and for that i want to step + + + align:start position:0% +focus on and for that i want to step +back a little bit and say okay what is + + align:start position:0% +back a little bit and say okay what is + + + align:start position:0% +back a little bit and say okay what is +actually a model + + align:start position:0% +actually a model + + + align:start position:0% +actually a model +what are economic models are trying to + + align:start position:0% +what are economic models are trying to + + + align:start position:0% +what are economic models are trying to +do and so what is a model a model + + align:start position:0% +do and so what is a model a model + + + align:start position:0% +do and so what is a model a model +is a simplified representation of the + + align:start position:0% +is a simplified representation of the + + + align:start position:0% +is a simplified representation of the +world um + + align:start position:0% +world um + + + align:start position:0% +world um +and we we know in some sense that the + + align:start position:0% +and we we know in some sense that the + + + align:start position:0% +and we we know in some sense that the +assumptions of the models are not true + + align:start position:0% +assumptions of the models are not true + + + align:start position:0% +assumptions of the models are not true +they're sort of supposed to be + + align:start position:0% +they're sort of supposed to be + + + align:start position:0% +they're sort of supposed to be +approximately true and + + align:start position:0% +approximately true and + + + align:start position:0% +approximately true and +exactly uh false so when you think about + + align:start position:0% +exactly uh false so when you think about + + + align:start position:0% +exactly uh false so when you think about +like used models of the earth + + align:start position:0% +like used models of the earth + + + align:start position:0% +like used models of the earth +in some sense they're like flat + + align:start position:0% +in some sense they're like flat + + + align:start position:0% +in some sense they're like flat +spherical ellipsoid and so on and so + + align:start position:0% +spherical ellipsoid and so on and so + + + align:start position:0% +spherical ellipsoid and so on and so +forth + + align:start position:0% +forth + + + align:start position:0% +forth +um models so good models do not accounts + + align:start position:0% +um models so good models do not accounts + + + align:start position:0% +um models so good models do not accounts +for bumps and and grooves and so on + + align:start position:0% +for bumps and and grooves and so on + + + align:start position:0% +for bumps and and grooves and so on +a perfect replica of the earth is not a + + align:start position:0% +a perfect replica of the earth is not a + + + align:start position:0% +a perfect replica of the earth is not a +useful model to use + + align:start position:0% +useful model to use + + + align:start position:0% +useful model to use +you kind of want to simplify and capture + + align:start position:0% +you kind of want to simplify and capture + + + align:start position:0% +you kind of want to simplify and capture +the essence of what's what's um + + align:start position:0% +the essence of what's what's um + + + align:start position:0% +the essence of what's what's um +important so now then what's a good + + align:start position:0% +important so now then what's a good + + + align:start position:0% +important so now then what's a good +model well a good model and you can read + + align:start position:0% +model well a good model and you can read + + + align:start position:0% +model well a good model and you can read +a bit about this in + + align:start position:0% +a bit about this in + + + align:start position:0% +a bit about this in +and get back in lapses paper a good + + align:start position:0% +and get back in lapses paper a good + + + align:start position:0% +and get back in lapses paper a good +model is supposed to be simple + + align:start position:0% +model is supposed to be simple + + + align:start position:0% +model is supposed to be simple +it's supposed to be easy to work with + + align:start position:0% +it's supposed to be easy to work with + + + align:start position:0% +it's supposed to be easy to work with +and tractable so in some sense you have + + align:start position:0% +and tractable so in some sense you have + + + align:start position:0% +and tractable so in some sense you have +only like a few variables or a few + + align:start position:0% +only like a few variables or a few + + + align:start position:0% +only like a few variables or a few +things that you uh + + align:start position:0% +things that you uh + + + align:start position:0% +things that you uh +that matter it's conceptually insightful + + align:start position:0% +that matter it's conceptually insightful + + + align:start position:0% +that matter it's conceptually insightful +in the sense that like + + align:start position:0% +in the sense that like + + + align:start position:0% +in the sense that like +it it focuses on important things it + + align:start position:0% +it it focuses on important things it + + + align:start position:0% +it it focuses on important things it +tells you about behavior that we really + + align:start position:0% +tells you about behavior that we really + + + align:start position:0% +tells you about behavior that we really +care about and important ideas + + align:start position:0% +care about and important ideas + + + align:start position:0% +care about and important ideas +it's generalizable in a sense like + + align:start position:0% +it's generalizable in a sense like + + + align:start position:0% +it's generalizable in a sense like +ideally we are trying to look for some + + align:start position:0% +ideally we are trying to look for some + + + align:start position:0% +ideally we are trying to look for some +behaviors + + align:start position:0% +behaviors + + + align:start position:0% +behaviors +that are general in some sense so if i + + align:start position:0% +that are general in some sense so if i + + + align:start position:0% +that are general in some sense so if i +can just explain you one simple choice + + align:start position:0% +can just explain you one simple choice + + + align:start position:0% +can just explain you one simple choice +in one domain + + align:start position:0% +in one domain + + + align:start position:0% +in one domain +and write a model about it but that + + align:start position:0% +and write a model about it but that + + + align:start position:0% +and write a model about it but that +model doesn't apply for anything else + + align:start position:0% +model doesn't apply for anything else + + + align:start position:0% +model doesn't apply for anything else +that's not a good model um to work with + + align:start position:0% +that's not a good model um to work with + + + align:start position:0% +that's not a good model um to work with +the model is supposed to be falsifiable + + align:start position:0% +the model is supposed to be falsifiable + + + align:start position:0% +the model is supposed to be falsifiable +in a sense like we can actually test + + align:start position:0% +in a sense like we can actually test + + + align:start position:0% +in a sense like we can actually test +them + + align:start position:0% +them + + + align:start position:0% +them +and that's kind of what we do in + + align:start position:0% +and that's kind of what we do in + + + align:start position:0% +and that's kind of what we do in +experimental and behavioral economics we + + align:start position:0% +experimental and behavioral economics we + + + align:start position:0% +experimental and behavioral economics we +try to test people's theories or + + align:start position:0% +try to test people's theories or + + + align:start position:0% +try to test people's theories or +our theories and then sort of empirical + + align:start position:0% +our theories and then sort of empirical + + + align:start position:0% +our theories and then sort of empirical +work and then sort of falsify + + align:start position:0% +work and then sort of falsify + + + align:start position:0% +work and then sort of falsify +or reject models that are wrong + + align:start position:0% + + + + align:start position:0% + +and we should be able to make good + + align:start position:0% +and we should be able to make good + + + align:start position:0% +and we should be able to make good +predictions for people's + + align:start position:0% +predictions for people's + + + align:start position:0% +predictions for people's +behavior now are the assumptions of the + + align:start position:0% +behavior now are the assumptions of the + + + align:start position:0% +behavior now are the assumptions of the +standard models true for most people + + align:start position:0% +standard models true for most people + + + align:start position:0% +standard models true for most people +the answer is no but the key insight + + align:start position:0% +the answer is no but the key insight + + + align:start position:0% +the answer is no but the key insight +here is that + + align:start position:0% +here is that + + + align:start position:0% +here is that +the key properties of good models is + + align:start position:0% +the key properties of good models is + + + align:start position:0% +the key properties of good models is +simplicity so in some sense + + align:start position:0% +simplicity so in some sense + + + align:start position:0% +simplicity so in some sense +assuming perfect rationality selfishness + + align:start position:0% +assuming perfect rationality selfishness + + + align:start position:0% +assuming perfect rationality selfishness +and willpower is actually a simple thing + + align:start position:0% +and willpower is actually a simple thing + + + align:start position:0% +and willpower is actually a simple thing +to do in some sense + + align:start position:0% +to do in some sense + + + align:start position:0% +to do in some sense +the reason why economists have made + + align:start position:0% +the reason why economists have made + + + align:start position:0% +the reason why economists have made +those assumptions to start with + + align:start position:0% +those assumptions to start with + + + align:start position:0% +those assumptions to start with +is not necessarily because i thought + + align:start position:0% +is not necessarily because i thought + + + align:start position:0% +is not necessarily because i thought +people are perfectly rational or or + + align:start position:0% +people are perfectly rational or or + + + align:start position:0% +people are perfectly rational or or +that they're not these uh psychological + + align:start position:0% +that they're not these uh psychological + + + align:start position:0% +that they're not these uh psychological +issues going on + + align:start position:0% +issues going on + + + align:start position:0% +issues going on +the reason is actually simplicity it's + + align:start position:0% +the reason is actually simplicity it's + + + align:start position:0% +the reason is actually simplicity it's +an easy thing to do you model how you + + align:start position:0% +an easy thing to do you model how you + + + align:start position:0% +an easy thing to do you model how you +think people should behave + + align:start position:0% +think people should behave + + + align:start position:0% +think people should behave +and how you behave perfectly and + + align:start position:0% +and how you behave perfectly and + + + align:start position:0% +and how you behave perfectly and +making some of these models sort of + + align:start position:0% +making some of these models sort of + + + align:start position:0% +making some of these models sort of +richer in their psychology is actually + + align:start position:0% +richer in their psychology is actually + + + align:start position:0% +richer in their psychology is actually +complicated + + align:start position:0% +complicated + + + align:start position:0% +complicated +and makes the models more complex and + + align:start position:0% +and makes the models more complex and + + + align:start position:0% +and makes the models more complex and +harder to analyze + + align:start position:0% +harder to analyze + + + align:start position:0% +harder to analyze +so that is just to say well then the + + align:start position:0% +so that is just to say well then the + + + align:start position:0% +so that is just to say well then the +question is like can we find some + + align:start position:0% +question is like can we find some + + + align:start position:0% +question is like can we find some +assumptions of economics can we make + + align:start position:0% +assumptions of economics can we make + + + align:start position:0% +assumptions of economics can we make +them more realistic in a tractable way + + align:start position:0% +them more realistic in a tractable way + + + align:start position:0% +them more realistic in a tractable way +in a sense can we find key things that + + align:start position:0% +in a sense can we find key things that + + + align:start position:0% +in a sense can we find key things that +we change that + + align:start position:0% +we change that + + + align:start position:0% +we change that +keep the models tractable while then + + align:start position:0% +keep the models tractable while then + + + align:start position:0% +keep the models tractable while then +also explaining important things better + + align:start position:0% +also explaining important things better + + + align:start position:0% +also explaining important things better +than we can before + + align:start position:0% +than we can before + + + align:start position:0% +than we can before +right so it's not about just taking all + + align:start position:0% +right so it's not about just taking all + + + align:start position:0% +right so it's not about just taking all +sorts of like psychological issues that + + align:start position:0% +sorts of like psychological issues that + + + align:start position:0% +sorts of like psychological issues that +might be going on and say well + + align:start position:0% +might be going on and say well + + + align:start position:0% +might be going on and say well +economic assumptions are wrong or models + + align:start position:0% +economic assumptions are wrong or models + + + align:start position:0% +economic assumptions are wrong or models +of + + align:start position:0% +of + + + align:start position:0% +of +economics are wrong or the assumptions + + align:start position:0% +economics are wrong or the assumptions + + + align:start position:0% +economics are wrong or the assumptions +of those are wrong we know that these + + align:start position:0% +of those are wrong we know that these + + + align:start position:0% +of those are wrong we know that these +assumptions are wrong + + align:start position:0% +assumptions are wrong + + + align:start position:0% +assumptions are wrong +the question is can we make somewhat + + align:start position:0% +the question is can we make somewhat + + + align:start position:0% +the question is can we make somewhat +simple assumptions or improvements of + + align:start position:0% +simple assumptions or improvements of + + + align:start position:0% +simple assumptions or improvements of +those assumptions + + align:start position:0% +those assumptions + + + align:start position:0% +those assumptions +based on insights from psychology and + + align:start position:0% +based on insights from psychology and + + + align:start position:0% +based on insights from psychology and +other fields that help us improve those + + align:start position:0% +other fields that help us improve those + + + align:start position:0% +other fields that help us improve those +models + + align:start position:0% +models + + + align:start position:0% +models +and then make better uh predictions and + + align:start position:0% +and then make better uh predictions and + + + align:start position:0% +and then make better uh predictions and +all of that in a tractable + + align:start position:0% +all of that in a tractable + + + align:start position:0% +all of that in a tractable +way so now this is very important here + + align:start position:0% +way so now this is very important here + + + align:start position:0% +way so now this is very important here +i'm a good behavioral economic economist + + align:start position:0% +i'm a good behavioral economic economist + + + align:start position:0% +i'm a good behavioral economic economist +or + + align:start position:0% +or + + + align:start position:0% +or +a good student in this class is also a + + align:start position:0% +a good student in this class is also a + + + align:start position:0% +a good student in this class is also a +good economist + + align:start position:0% +good economist + + + align:start position:0% +good economist +behavioral economics is not sort of + + align:start position:0% +behavioral economics is not sort of + + + align:start position:0% +behavioral economics is not sort of +trying to replace standard economics + + align:start position:0% +trying to replace standard economics + + + align:start position:0% +trying to replace standard economics +so i don't want you to go to my + + align:start position:0% +so i don't want you to go to my + + + align:start position:0% +so i don't want you to go to my +colleagues and say you know 1401 1402 + + align:start position:0% +colleagues and say you know 1401 1402 + + + align:start position:0% +colleagues and say you know 1401 1402 +and so on this is all garbage frank is + + align:start position:0% +and so on this is all garbage frank is + + + align:start position:0% +and so on this is all garbage frank is +telling you + + align:start position:0% +telling you + + + align:start position:0% +telling you +um we do things differently in fact you + + align:start position:0% +um we do things differently in fact you + + + align:start position:0% +um we do things differently in fact you +very much need to know those kinds of + + align:start position:0% +very much need to know those kinds of + + + align:start position:0% +very much need to know those kinds of +things from like standard economics + + align:start position:0% +things from like standard economics + + + align:start position:0% +things from like standard economics +to understand what the assumptions are + + align:start position:0% +to understand what the assumptions are + + + align:start position:0% +to understand what the assumptions are +and how to best to deviate + + align:start position:0% +and how to best to deviate + + + align:start position:0% +and how to best to deviate +from that and so as such then like key + + align:start position:0% +from that and so as such then like key + + + align:start position:0% +from that and so as such then like key +principle + + align:start position:0% +principle + + + align:start position:0% +principle +principles of mainstream economics + + align:start position:0% +principles of mainstream economics + + + align:start position:0% +principles of mainstream economics +continue to apply + + align:start position:0% +continue to apply + + + align:start position:0% +continue to apply +decision makers are still highly + + align:start position:0% +decision makers are still highly + + + align:start position:0% +decision makers are still highly +sophisticated markets and incentives + + align:start position:0% +sophisticated markets and incentives + + + align:start position:0% +sophisticated markets and incentives +matter + + align:start position:0% +matter + + + align:start position:0% +matter +they're in fact play a key role in + + align:start position:0% +they're in fact play a key role in + + + align:start position:0% +they're in fact play a key role in +shaping behavior + + align:start position:0% +shaping behavior + + + align:start position:0% +shaping behavior +and markets allocate resources well most + + align:start position:0% +and markets allocate resources well most + + + align:start position:0% +and markets allocate resources well most +of the time the question is can we sort + + align:start position:0% +of the time the question is can we sort + + + align:start position:0% +of the time the question is can we sort +of focus on important deviations and try + + align:start position:0% +of focus on important deviations and try + + + align:start position:0% +of focus on important deviations and try +to fix + + align:start position:0% +to fix + + + align:start position:0% +to fix +those and then again like sort of + + align:start position:0% +those and then again like sort of + + + align:start position:0% +those and then again like sort of +methodological principles still apply + + align:start position:0% +methodological principles still apply + + + align:start position:0% +methodological principles still apply +you use observational experimental data + + align:start position:0% +you use observational experimental data + + + align:start position:0% +you use observational experimental data +mathematical models are good and so on + + align:start position:0% +mathematical models are good and so on + + + align:start position:0% +mathematical models are good and so on +and so forth + + align:start position:0% +and so forth + + + align:start position:0% +and so forth +and ideally models would sort of nest + + align:start position:0% +and ideally models would sort of nest + + + align:start position:0% +and ideally models would sort of nest +the special case stuff + + align:start position:0% +the special case stuff + + + align:start position:0% +the special case stuff +perfect rationality or perfectly sort of + + align:start position:0% +perfect rationality or perfectly sort of + + + align:start position:0% +perfect rationality or perfectly sort of +standard economic models i mean trying + + align:start position:0% +standard economic models i mean trying + + + align:start position:0% +standard economic models i mean trying +to build in some parameters that + + align:start position:0% +to build in some parameters that + + + align:start position:0% +to build in some parameters that +deviates from that and try to understand + + align:start position:0% +deviates from that and try to understand + + + align:start position:0% +deviates from that and try to understand +can we make better + + align:start position:0% +can we make better + + + align:start position:0% +can we make better +predictions and then so often prices are + + align:start position:0% +predictions and then so often prices are + + + align:start position:0% +predictions and then so often prices are +actually the most important aspects of + + align:start position:0% +actually the most important aspects of + + + align:start position:0% +actually the most important aspects of +choice + + align:start position:0% +choice + + + align:start position:0% +choice +here's one experiment by ito at all that + + align:start position:0% +here's one experiment by ito at all that + + + align:start position:0% +here's one experiment by ito at all that +try to essentially sort of change + + align:start position:0% +try to essentially sort of change + + + align:start position:0% +try to essentially sort of change +people's um + + align:start position:0% +people's um + + + align:start position:0% +people's um +energy usage and so on and they have + + align:start position:0% +energy usage and so on and they have + + + align:start position:0% +energy usage and so on and they have +like two treatments one is uh + + align:start position:0% +like two treatments one is uh + + + align:start position:0% +like two treatments one is uh +called moral suration which essentially + + align:start position:0% +called moral suration which essentially + + + align:start position:0% +called moral suration which essentially +is telling people uh uh sort of + + align:start position:0% +is telling people uh uh sort of + + + align:start position:0% +is telling people uh uh sort of +appealing to their morals in some ways + + align:start position:0% +appealing to their morals in some ways + + + align:start position:0% +appealing to their morals in some ways +and the other one is essentially just + + align:start position:0% +and the other one is essentially just + + + align:start position:0% +and the other one is essentially just +financial incentives straight up + + align:start position:0% +financial incentives straight up + + + align:start position:0% +financial incentives straight up +changing the price of people's choices + + align:start position:0% +changing the price of people's choices + + + align:start position:0% +changing the price of people's choices +and what you see in this experiment + + align:start position:0% +and what you see in this experiment + + + align:start position:0% +and what you see in this experiment +essentially is + + align:start position:0% +essentially is + + + align:start position:0% +essentially is +um uh there's a in red you have the + + align:start position:0% +um uh there's a in red you have the + + + align:start position:0% +um uh there's a in red you have the +impact is all treatment effects over + + align:start position:0% +impact is all treatment effects over + + + align:start position:0% +impact is all treatment effects over +time + + align:start position:0% +time + + + align:start position:0% +time +comparing like a treatment group and a + + align:start position:0% +comparing like a treatment group and a + + + align:start position:0% +comparing like a treatment group and a +control group and you see + + align:start position:0% +control group and you see + + + align:start position:0% +control group and you see +and read the treatment effects of the + + align:start position:0% +and read the treatment effects of the + + + align:start position:0% +and read the treatment effects of the +incentives and you see these are + + align:start position:0% +incentives and you see these are + + + align:start position:0% +incentives and you see these are +relatively large and persists over time + + align:start position:0% +relatively large and persists over time + + + align:start position:0% +relatively large and persists over time +and you see the treatment effects of the + + align:start position:0% +and you see the treatment effects of the + + + align:start position:0% +and you see the treatment effects of the +moral suasion treatment which + + align:start position:0% +moral suasion treatment which + + + align:start position:0% +moral suasion treatment which +happens to be you know reasonably large + + align:start position:0% +happens to be you know reasonably large + + + align:start position:0% +happens to be you know reasonably large +to start with but essentially just goes + + align:start position:0% +to start with but essentially just goes + + + align:start position:0% +to start with but essentially just goes +away + + align:start position:0% +away + + + align:start position:0% +away +what we learned from that we were + + align:start position:0% +what we learned from that we were + + + align:start position:0% +what we learned from that we were +learned from that prices matter and + + align:start position:0% +learned from that prices matter and + + + align:start position:0% +learned from that prices matter and +maybe in this case + + align:start position:0% +maybe in this case + + + align:start position:0% +maybe in this case +moral surveillance is just not that + + align:start position:0% +moral surveillance is just not that + + + align:start position:0% +moral surveillance is just not that +important and that's perfectly fine + + align:start position:0% +important and that's perfectly fine + + + align:start position:0% +important and that's perfectly fine +we're trying to identify sort of + + align:start position:0% +we're trying to identify sort of + + + align:start position:0% +we're trying to identify sort of +situations or cases where some of the + + align:start position:0% +situations or cases where some of the + + + align:start position:0% +situations or cases where some of the +underlying psychological issues are + + align:start position:0% +underlying psychological issues are + + + align:start position:0% +underlying psychological issues are +important and we've learned from + + align:start position:0% +important and we've learned from + + + align:start position:0% +important and we've learned from +an experiment that in some cases this + + align:start position:0% +an experiment that in some cases this + + + align:start position:0% +an experiment that in some cases this +doesn't apply well so be it then we + + align:start position:0% +doesn't apply well so be it then we + + + align:start position:0% +doesn't apply well so be it then we +should + + align:start position:0% +should + + + align:start position:0% +should +focus on other cases where the + + align:start position:0% +focus on other cases where the + + + align:start position:0% +focus on other cases where the +psychological issues are + + align:start position:0% +psychological issues are + + + align:start position:0% +psychological issues are +are more important okay so then um + + align:start position:0% +are more important okay so then um + + + align:start position:0% +are more important okay so then um +what sort of our broad approach to each + + align:start position:0% +what sort of our broad approach to each + + + align:start position:0% +what sort of our broad approach to each +topic we're trying to sort of start with + + align:start position:0% +topic we're trying to sort of start with + + + align:start position:0% +topic we're trying to sort of start with +intuitive empirical and uh experimental + + align:start position:0% +intuitive empirical and uh experimental + + + align:start position:0% +intuitive empirical and uh experimental +examples how people behave in in some + + align:start position:0% +examples how people behave in in some + + + align:start position:0% +examples how people behave in in some +situations + + align:start position:0% +situations + + + align:start position:0% +situations +we're trying to think about their + + align:start position:0% +we're trying to think about their + + + align:start position:0% +we're trying to think about their +motivations trying to see about how they + + align:start position:0% +motivations trying to see about how they + + + align:start position:0% +motivations trying to see about how they +make choices and behaviors and how they + + align:start position:0% +make choices and behaviors and how they + + + align:start position:0% +make choices and behaviors and how they +behave in certain situations and then + + align:start position:0% +behave in certain situations and then + + + align:start position:0% +behave in certain situations and then +we're going to try to sort of model this + + align:start position:0% +we're going to try to sort of model this + + + align:start position:0% +we're going to try to sort of model this +in a more precise way + + align:start position:0% +in a more precise way + + + align:start position:0% +in a more precise way +and try to consider how the modeling of + + align:start position:0% +and try to consider how the modeling of + + + align:start position:0% +and try to consider how the modeling of +that perhaps deviates from the + + align:start position:0% +that perhaps deviates from the + + + align:start position:0% +that perhaps deviates from the +neoclassical + + align:start position:0% +neoclassical + + + align:start position:0% +neoclassical +uh or sort of the classical model of + + align:start position:0% +uh or sort of the classical model of + + + align:start position:0% +uh or sort of the classical model of +economics some other times you also just + + align:start position:0% +economics some other times you also just + + + align:start position:0% +economics some other times you also just +start from the classical model of + + align:start position:0% +start from the classical model of + + + align:start position:0% +start from the classical model of +economics look at the predictions and + + align:start position:0% +economics look at the predictions and + + + align:start position:0% +economics look at the predictions and +say well + + align:start position:0% +say well + + + align:start position:0% +say well +can we reject that or do we make certain + + align:start position:0% +can we reject that or do we make certain + + + align:start position:0% +can we reject that or do we make certain +predictions that are just not true and + + align:start position:0% +predictions that are just not true and + + + align:start position:0% +predictions that are just not true and +then say can we sort of improve those + + align:start position:0% +then say can we sort of improve those + + + align:start position:0% +then say can we sort of improve those +types of + + align:start position:0% +types of + + + align:start position:0% +types of +assumptions and then overall they're + + align:start position:0% +assumptions and then overall they're + + + align:start position:0% +assumptions and then overall they're +trying to think about then you know how + + align:start position:0% +trying to think about then you know how + + + align:start position:0% +trying to think about then you know how +these + + align:start position:0% +these + + + align:start position:0% +these +hypotheses or deviations might be able + + align:start position:0% +hypotheses or deviations might be able + + + align:start position:0% +hypotheses or deviations might be able +to explain how people behave and markets + + align:start position:0% +to explain how people behave and markets + + + align:start position:0% +to explain how people behave and markets +and what choices they make + + align:start position:0% +and what choices they make + + + align:start position:0% +and what choices they make +and how perhaps we can think about + + align:start position:0% +and how perhaps we can think about + + + align:start position:0% +and how perhaps we can think about +policies that might affect the people's + + align:start position:0% +policies that might affect the people's + + + align:start position:0% +policies that might affect the people's +well-being + + align:start position:0% +well-being + + + align:start position:0% +well-being +their welfare or any other consequences + + align:start position:0% +their welfare or any other consequences + + + align:start position:0% +their welfare or any other consequences +any questions so far + + align:start position:0% + + + + align:start position:0% + +okay so um now i want to give you one + + align:start position:0% +okay so um now i want to give you one + + + align:start position:0% +okay so um now i want to give you one +very + + align:start position:0% +very + + + align:start position:0% +very +simple and some sense stylized example + + align:start position:0% +simple and some sense stylized example + + + align:start position:0% +simple and some sense stylized example +of uh which would + + align:start position:0% +of uh which would + + + align:start position:0% +of uh which would +demonstrate a little bit what sort of + + align:start position:0% +demonstrate a little bit what sort of + + + align:start position:0% +demonstrate a little bit what sort of +like you know classical economic + + align:start position:0% +like you know classical economic + + + align:start position:0% +like you know classical economic +uh standard uh economic assumptions are + + align:start position:0% +uh standard uh economic assumptions are + + + align:start position:0% +uh standard uh economic assumptions are +and may + + align:start position:0% +and may + + + align:start position:0% +and may +how sort of enriching a model with + + align:start position:0% +how sort of enriching a model with + + + align:start position:0% +how sort of enriching a model with +psychological considerations + + align:start position:0% +psychological considerations + + + align:start position:0% +psychological considerations +um might be more powerful so + + align:start position:0% +um might be more powerful so + + + align:start position:0% +um might be more powerful so +um when you think about laptops in class + + align:start position:0% +um when you think about laptops in class + + + align:start position:0% +um when you think about laptops in class +what are sort of + + align:start position:0% +what are sort of + + + align:start position:0% +what are sort of +standard economic concept considerations + + align:start position:0% +standard economic concept considerations + + + align:start position:0% +standard economic concept considerations +should you allow laptops should they be + + align:start position:0% +should you allow laptops should they be + + + align:start position:0% +should you allow laptops should they be +laptops in class is that a good thing or + + align:start position:0% +laptops in class is that a good thing or + + + align:start position:0% +laptops in class is that a good thing or +a bad thing or + + align:start position:0% +a bad thing or + + + align:start position:0% +a bad thing or +what do we think about that + + align:start position:0% + + + + align:start position:0% + +and now i'm asking for like standard + + align:start position:0% +and now i'm asking for like standard + + + align:start position:0% +and now i'm asking for like standard +non-psychological issues just saying + + align:start position:0% +non-psychological issues just saying + + + align:start position:0% +non-psychological issues just saying +like + + align:start position:0% +like + + + align:start position:0% +like +he went to like a classical economist + + align:start position:0% +he went to like a classical economist + + + align:start position:0% +he went to like a classical economist +and says should we allow laptops in + + align:start position:0% +and says should we allow laptops in + + + align:start position:0% +and says should we allow laptops in +class + + align:start position:0% +class + + + align:start position:0% +class +what would be considerations for that + + align:start position:0% +what would be considerations for that + + + align:start position:0% +what would be considerations for that +yeah uh + + align:start position:0% +yeah uh + + + align:start position:0% +yeah uh +yes so you know you could call that + + align:start position:0% +yes so you know you could call that + + + align:start position:0% +yes so you know you could call that +a psychological or not but essentially + + align:start position:0% +a psychological or not but essentially + + + align:start position:0% +a psychological or not but essentially +it could distract people essentially and + + align:start position:0% +it could distract people essentially and + + + align:start position:0% +it could distract people essentially and +that's uh externalities tend to be sort + + align:start position:0% +that's uh externalities tend to be sort + + + align:start position:0% +that's uh externalities tend to be sort +of like + + align:start position:0% +of like + + + align:start position:0% +of like +uh very much like in classical economics + + align:start position:0% +uh very much like in classical economics + + + align:start position:0% +uh very much like in classical economics +essentially if you smoke it affects + + align:start position:0% +essentially if you smoke it affects + + + align:start position:0% +essentially if you smoke it affects +others similarly if a laptop it might + + align:start position:0% +others similarly if a laptop it might + + + align:start position:0% +others similarly if a laptop it might +affect others + + align:start position:0% +affect others + + + align:start position:0% +affect others +it's a little bit sort of in the middle + + align:start position:0% +it's a little bit sort of in the middle + + + align:start position:0% +it's a little bit sort of in the middle +between psychological and economic + + align:start position:0% +between psychological and economic + + + align:start position:0% +between psychological and economic +considerations because in some sense + + align:start position:0% +considerations because in some sense + + + align:start position:0% +considerations because in some sense +uh you know if somebody next to you + + align:start position:0% +uh you know if somebody next to you + + + align:start position:0% +uh you know if somebody next to you +would use a laptop + + align:start position:0% +would use a laptop + + + align:start position:0% +would use a laptop +and i would just say well why don't you + + align:start position:0% +and i would just say well why don't you + + + align:start position:0% +and i would just say well why don't you +just focus on class anyway you should be + + align:start position:0% +just focus on class anyway you should be + + + align:start position:0% +just focus on class anyway you should be +able to just ignore that + + align:start position:0% +able to just ignore that + + + align:start position:0% +able to just ignore that +but setting that aside that exactly + + align:start position:0% +but setting that aside that exactly + + + align:start position:0% +but setting that aside that exactly +externalities are surely one + + align:start position:0% +externalities are surely one + + + align:start position:0% +externalities are surely one +considerations that we have + + align:start position:0% +considerations that we have + + + align:start position:0% +considerations that we have +what's the pro side why would we allow + + align:start position:0% +what's the pro side why would we allow + + + align:start position:0% +what's the pro side why would we allow +laptops + + align:start position:0% +laptops + + + align:start position:0% +laptops +what's good about laptops in class yeah + + align:start position:0% +what's good about laptops in class yeah + + + align:start position:0% +what's good about laptops in class yeah +like it could just be efficient for + + align:start position:0% +like it could just be efficient for + + + align:start position:0% +like it could just be efficient for +taking notes some people might need to + + align:start position:0% +taking notes some people might need to + + + align:start position:0% +taking notes some people might need to +use them some people maybe are + + align:start position:0% +use them some people maybe are + + + align:start position:0% +use them some people maybe are +dispensing + + align:start position:0% +dispensing + + + align:start position:0% +dispensing +stuff like that so it's just good + + align:start position:0% +stuff like that so it's just good + + + align:start position:0% +stuff like that so it's just good +exactly it's like a useful technology + + align:start position:0% +exactly it's like a useful technology + + + align:start position:0% +exactly it's like a useful technology +to take notes and you might just be + + align:start position:0% +to take notes and you might just be + + + align:start position:0% +to take notes and you might just be +better that it might be more comfortable + + align:start position:0% +better that it might be more comfortable + + + align:start position:0% +better that it might be more comfortable +it's easier for it to do + + align:start position:0% +it's easier for it to do + + + align:start position:0% +it's easier for it to do +maybe it's also saved some paper or + + align:start position:0% +maybe it's also saved some paper or + + + align:start position:0% +maybe it's also saved some paper or +whatever + + align:start position:0% +whatever + + + align:start position:0% +whatever +what else are laptops good for yeah i + + align:start position:0% +what else are laptops good for yeah i + + + align:start position:0% +what else are laptops good for yeah i +mean + + align:start position:0% +mean + + + align:start position:0% +mean +more choices just always better so if + + align:start position:0% +more choices just always better so if + + + align:start position:0% +more choices just always better so if +each person has their laptop they can + + align:start position:0% +each person has their laptop they can + + + align:start position:0% +each person has their laptop they can +choose what's better for them + + align:start position:0% +choose what's better for them + + + align:start position:0% +choose what's better for them +yes exactly if you are so inclined and + + align:start position:0% +yes exactly if you are so inclined and + + + align:start position:0% +yes exactly if you are so inclined and +want to watch football from yesterday + + align:start position:0% +want to watch football from yesterday + + + align:start position:0% +want to watch football from yesterday +the replay and so on if you prefer that + + align:start position:0% +the replay and so on if you prefer that + + + align:start position:0% +the replay and so on if you prefer that +and that's good for you + + align:start position:0% +and that's good for you + + + align:start position:0% +and that's good for you +uh you know who should be stopping you + + align:start position:0% +uh you know who should be stopping you + + + align:start position:0% +uh you know who should be stopping you +right and so + + align:start position:0% +right and so + + + align:start position:0% +right and so +uh at some sense laptops are useful for + + align:start position:0% +uh at some sense laptops are useful for + + + align:start position:0% +uh at some sense laptops are useful for +um + + align:start position:0% +um + + + align:start position:0% +um +note-taking they're also useful for uh + + align:start position:0% +note-taking they're also useful for uh + + + align:start position:0% +note-taking they're also useful for uh +non-class activities + + align:start position:0% +non-class activities + + + align:start position:0% +non-class activities +and as you say each student should be + + align:start position:0% +and as you say each student should be + + + align:start position:0% +and as you say each student should be +able to choose for themselves + + align:start position:0% +able to choose for themselves + + + align:start position:0% +able to choose for themselves +um what's good and um uh that may be + + align:start position:0% +um what's good and um uh that may be + + + align:start position:0% +um what's good and um uh that may be +involved like paying attention or or or + + align:start position:0% +involved like paying attention or or or + + + align:start position:0% +involved like paying attention or or or +not + + align:start position:0% +not + + + align:start position:0% +not +now what else sort of some psychological + + align:start position:0% +now what else sort of some psychological + + + align:start position:0% +now what else sort of some psychological +conservations we had one of them which + + align:start position:0% +conservations we had one of them which + + + align:start position:0% +conservations we had one of them which +is essentially distracting others which + + align:start position:0% +is essentially distracting others which + + + align:start position:0% +is essentially distracting others which +essentially is the externality + + align:start position:0% +essentially is the externality + + + align:start position:0% +essentially is the externality +um what else yeah + + align:start position:0% + + + + align:start position:0% + +right exactly you might sort of uh have + + align:start position:0% +right exactly you might sort of uh have + + + align:start position:0% +right exactly you might sort of uh have +all the best intentions of taking notes + + align:start position:0% +all the best intentions of taking notes + + + align:start position:0% +all the best intentions of taking notes +of the what i said previously but then + + align:start position:0% +of the what i said previously but then + + + align:start position:0% +of the what i said previously but then +you know + + align:start position:0% +you know + + + align:start position:0% +you know +it gets a little dull and boring at + + align:start position:0% +it gets a little dull and boring at + + + align:start position:0% +it gets a little dull and boring at +minutes when it's 40 + + align:start position:0% +minutes when it's 40 + + + align:start position:0% +minutes when it's 40 +and you might sort of be inclined to + + align:start position:0% +and you might sort of be inclined to + + + align:start position:0% +and you might sort of be inclined to +sort of think about other uh stuff and + + align:start position:0% +sort of think about other uh stuff and + + + align:start position:0% +sort of think about other uh stuff and +sort of start surfing in the internet or + + align:start position:0% +sort of start surfing in the internet or + + + align:start position:0% +sort of start surfing in the internet or +the like or start chatting or whatever + + align:start position:0% +the like or start chatting or whatever + + + align:start position:0% +the like or start chatting or whatever +that sort of essentially limited + + align:start position:0% +that sort of essentially limited + + + align:start position:0% +that sort of essentially limited +self-control one way or the other + + align:start position:0% +self-control one way or the other + + + align:start position:0% +self-control one way or the other +yeah yeah i think so i think even if you + + align:start position:0% +yeah yeah i think so i think even if you + + + align:start position:0% +yeah yeah i think so i think even if you +don't fall into the limitation + + align:start position:0% +don't fall into the limitation + + + align:start position:0% +don't fall into the limitation +you kind of have to spend energy + + align:start position:0% +you kind of have to spend energy + + + align:start position:0% +you kind of have to spend energy +resisting that temptation and that might + + align:start position:0% +resisting that temptation and that might + + + align:start position:0% +resisting that temptation and that might +kind of distract you + + align:start position:0% +kind of distract you + + + align:start position:0% +kind of distract you +right so there's some cognitive + + align:start position:0% +right so there's some cognitive + + + align:start position:0% +right so there's some cognitive +resources potentially from + + align:start position:0% +resources potentially from + + + align:start position:0% +resources potentially from +from that that's a very nice observation + + align:start position:0% +from that that's a very nice observation + + + align:start position:0% +from that that's a very nice observation +exactly that that also might be true + + align:start position:0% +exactly that that also might be true + + + align:start position:0% +exactly that that also might be true +there's another part to that which is + + align:start position:0% +there's another part to that which is + + + align:start position:0% +there's another part to that which is +people tend to overestimate how much + + align:start position:0% +people tend to overestimate how much + + + align:start position:0% +people tend to overestimate how much +they can multitask and there's + + align:start position:0% +they can multitask and there's + + + align:start position:0% +they can multitask and there's +like a large number of experiments that + + align:start position:0% +like a large number of experiments that + + + align:start position:0% +like a large number of experiments that +say well i'm actually paying attention + + align:start position:0% +say well i'm actually paying attention + + + align:start position:0% +say well i'm actually paying attention +i'm look you know i'm just sort of + + align:start position:0% +i'm look you know i'm just sort of + + + align:start position:0% +i'm look you know i'm just sort of +reading some other stuff i'm chatting + + align:start position:0% +reading some other stuff i'm chatting + + + align:start position:0% +reading some other stuff i'm chatting +with my friend + + align:start position:0% +with my friend + + + align:start position:0% +with my friend +um and people actually think they pay + + align:start position:0% +um and people actually think they pay + + + align:start position:0% +um and people actually think they pay +attention and they learn + + align:start position:0% +attention and they learn + + + align:start position:0% +attention and they learn +trust me they do not so essentially + + align:start position:0% +trust me they do not so essentially + + + align:start position:0% +trust me they do not so essentially +there's a large large literature on + + align:start position:0% +there's a large large literature on + + + align:start position:0% +there's a large large literature on +people thinking that they can + + align:start position:0% +people thinking that they can + + + align:start position:0% +people thinking that they can +multitask when in fact they cannot + + align:start position:0% +multitask when in fact they cannot + + + align:start position:0% +multitask when in fact they cannot +there's a very human thing to do + + align:start position:0% +there's a very human thing to do + + + align:start position:0% +there's a very human thing to do +you might think you know you can study + + align:start position:0% +you might think you know you can study + + + align:start position:0% +you might think you know you can study +for an exam by watching tv + + align:start position:0% +for an exam by watching tv + + + align:start position:0% +for an exam by watching tv +chances are you're not studying um very + + align:start position:0% +chances are you're not studying um very + + + align:start position:0% +chances are you're not studying um very +well so that's essentially some form of + + align:start position:0% +well so that's essentially some form of + + + align:start position:0% +well so that's essentially some form of +like um + + align:start position:0% +like um + + + align:start position:0% +like um +um overconfidence um + + align:start position:0% +um overconfidence um + + + align:start position:0% +um overconfidence um +right and then there's another part + + align:start position:0% +right and then there's another part + + + align:start position:0% +right and then there's another part +which is sort of like uh + + align:start position:0% +which is sort of like uh + + + align:start position:0% +which is sort of like uh +uh sort of some with different + + align:start position:0% +uh sort of some with different + + + align:start position:0% +uh sort of some with different +psychological consideration which is + + align:start position:0% +psychological consideration which is + + + align:start position:0% +psychological consideration which is +people tend to not like hard paternalism + + align:start position:0% +people tend to not like hard paternalism + + + align:start position:0% +people tend to not like hard paternalism +as in like if you sort of like we talk + + align:start position:0% +as in like if you sort of like we talk + + + align:start position:0% +as in like if you sort of like we talk +about this at the very end when we talk + + align:start position:0% +about this at the very end when we talk + + + align:start position:0% +about this at the very end when we talk +about policy + + align:start position:0% +about policy + + + align:start position:0% +about policy +people don't like certain hard rules + + align:start position:0% +people don't like certain hard rules + + + align:start position:0% +people don't like certain hard rules +about like you're allowed to do this + + align:start position:0% +about like you're allowed to do this + + + align:start position:0% +about like you're allowed to do this +where you don't allow to do x or y you + + align:start position:0% +where you don't allow to do x or y you + + + align:start position:0% +where you don't allow to do x or y you +have to come to class or whatever + + align:start position:0% +have to come to class or whatever + + + align:start position:0% +have to come to class or whatever +people tend to not like that um that's + + align:start position:0% +people tend to not like that um that's + + + align:start position:0% +people tend to not like that um that's +more like another sort of consideration + + align:start position:0% +more like another sort of consideration + + + align:start position:0% +more like another sort of consideration +you think about like what is the right + + align:start position:0% +you think about like what is the right + + + align:start position:0% +you think about like what is the right +policy um + + align:start position:0% +policy um + + + align:start position:0% +policy um +to do now what policy solutions could we + + align:start position:0% +to do now what policy solutions could we + + + align:start position:0% +to do now what policy solutions could we +do what what laptop policies have you + + align:start position:0% +do what what laptop policies have you + + + align:start position:0% +do what what laptop policies have you +seen or how do you think about them + + align:start position:0% + + + + align:start position:0% + +maybe somebody else yes + + align:start position:0% +maybe somebody else yes + + + align:start position:0% +maybe somebody else yes +i haven't seen it but let the people + + align:start position:0% +i haven't seen it but let the people + + + align:start position:0% +i haven't seen it but let the people +with laptops sit in the back + + align:start position:0% +with laptops sit in the back + + + align:start position:0% +with laptops sit in the back +yes you could have you could do that um + + align:start position:0% +yes you could have you could do that um + + + align:start position:0% +yes you could have you could do that um +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +and sort of that's kind of like + + align:start position:0% +and sort of that's kind of like + + + align:start position:0% +and sort of that's kind of like +minimizing the the externality + + align:start position:0% +minimizing the the externality + + + align:start position:0% +minimizing the the externality +potentially + + align:start position:0% +potentially + + + align:start position:0% +potentially +um it's not really helping with + + align:start position:0% +um it's not really helping with + + + align:start position:0% +um it's not really helping with +self-control i guess + + align:start position:0% +self-control i guess + + + align:start position:0% +self-control i guess +right because if particularly if you sit + + align:start position:0% +right because if particularly if you sit + + + align:start position:0% +right because if particularly if you sit +in the back nobody sees what you're + + align:start position:0% +in the back nobody sees what you're + + + align:start position:0% +in the back nobody sees what you're +doing + + align:start position:0% +doing + + + align:start position:0% +doing +um and you might be so inclined to to do + + align:start position:0% +um and you might be so inclined to to do + + + align:start position:0% +um and you might be so inclined to to do +all sorts of things + + align:start position:0% +all sorts of things + + + align:start position:0% +all sorts of things +uh yes + + align:start position:0% + + + + align:start position:0% + +right so that's sort of like hard + + align:start position:0% +right so that's sort of like hard + + + align:start position:0% +right so that's sort of like hard +paternalism with some uh + + align:start position:0% +paternalism with some uh + + + align:start position:0% +paternalism with some uh +exceptions potentially yeah + + align:start position:0% +exceptions potentially yeah + + + align:start position:0% +exceptions potentially yeah +um i've seen like only devices that are + + align:start position:0% +um i've seen like only devices that are + + + align:start position:0% +um i've seen like only devices that are +flat on the table + + align:start position:0% + + + + align:start position:0% + +for note-taking yeah i've seen + + align:start position:0% + + + + align:start position:0% + +track of class um so if they see you + + align:start position:0% +track of class um so if they see you + + + align:start position:0% +track of class um so if they see you +doing something + + align:start position:0% +doing something + + + align:start position:0% +doing something +not academic they can technically take + + align:start position:0% +not academic they can technically take + + + align:start position:0% +not academic they can technically take +you forward + + align:start position:0% +you forward + + + align:start position:0% +you forward +yeah that's what they're for no no + + align:start position:0% +yeah that's what they're for no no + + + align:start position:0% +yeah that's what they're for no no +um anything else + + align:start position:0% +um anything else + + + align:start position:0% +um anything else +i've seen classes where you're just + + align:start position:0% +i've seen classes where you're just + + + align:start position:0% +i've seen classes where you're just +allowed to use your laptop because i + + align:start position:0% +allowed to use your laptop because i + + + align:start position:0% +allowed to use your laptop because i +guess + + align:start position:0% + + + + align:start position:0% + +right exactly that's sort of less affair + + align:start position:0% +right exactly that's sort of less affair + + + align:start position:0% +right exactly that's sort of less affair +saying like you know what's best for you + + align:start position:0% +saying like you know what's best for you + + + align:start position:0% +saying like you know what's best for you +in some sense since this is sort of like + + align:start position:0% +in some sense since this is sort of like + + + align:start position:0% +in some sense since this is sort of like +a psychology income behavioral class + + align:start position:0% +a psychology income behavioral class + + + align:start position:0% +a psychology income behavioral class +uh you know i i tend to + + align:start position:0% +uh you know i i tend to + + + align:start position:0% +uh you know i i tend to +tend to disagree with some of those + + align:start position:0% +tend to disagree with some of those + + + align:start position:0% +tend to disagree with some of those +assumptions but yes exactly that's less + + align:start position:0% +assumptions but yes exactly that's less + + + align:start position:0% +assumptions but yes exactly that's less +affair + + align:start position:0% + + + + align:start position:0% + +any other thoughts + + align:start position:0% +any other thoughts + + + align:start position:0% +any other thoughts +uh okay so then uh here they are so + + align:start position:0% +uh okay so then uh here they are so + + + align:start position:0% +uh okay so then uh here they are so +there's um less affair + + align:start position:0% +there's um less affair + + + align:start position:0% +there's um less affair +there's educational intervention which + + align:start position:0% +there's educational intervention which + + + align:start position:0% +there's educational intervention which +essentially just providing people + + align:start position:0% +essentially just providing people + + + align:start position:0% +essentially just providing people +information + + align:start position:0% +information + + + align:start position:0% +information +about um um laptops or what laptops do + + align:start position:0% +about um um laptops or what laptops do + + + align:start position:0% +about um um laptops or what laptops do +for learning + + align:start position:0% +for learning + + + align:start position:0% +for learning +uh there's some experiments i'll show + + align:start position:0% +uh there's some experiments i'll show + + + align:start position:0% +uh there's some experiments i'll show +you in a second educational + + align:start position:0% +you in a second educational + + + align:start position:0% +you in a second educational +interventions tend to actually not + + align:start position:0% +interventions tend to actually not + + + align:start position:0% +interventions tend to actually not +work particularly well so essentially + + align:start position:0% +work particularly well so essentially + + + align:start position:0% +work particularly well so essentially +just giving people information tends to + + align:start position:0% +just giving people information tends to + + + align:start position:0% +just giving people information tends to +not change behavior + + align:start position:0% +not change behavior + + + align:start position:0% +not change behavior +um often in the way we'd like to do that + + align:start position:0% +um often in the way we'd like to do that + + + align:start position:0% +um often in the way we'd like to do that +you could tax laptop users + + align:start position:0% +you could tax laptop users + + + align:start position:0% +you could tax laptop users +say it's costly to do that would be the + + align:start position:0% +say it's costly to do that would be the + + + align:start position:0% +say it's costly to do that would be the +typical sort of like public economic + + align:start position:0% +typical sort of like public economic + + + align:start position:0% +typical sort of like public economic +sort of solution + + align:start position:0% +sort of solution + + + align:start position:0% +sort of solution +i think i'm not allowed to take money + + align:start position:0% +i think i'm not allowed to take money + + + align:start position:0% +i think i'm not allowed to take money +from you guys so so i might not not do + + align:start position:0% +from you guys so so i might not not do + + + align:start position:0% +from you guys so so i might not not do +that + + align:start position:0% +that + + + align:start position:0% +that +you could ban laptops this is from um + + align:start position:0% +you could ban laptops this is from um + + + align:start position:0% +you could ban laptops this is from um +that was a previous suggestion to say + + align:start position:0% +that was a previous suggestion to say + + + align:start position:0% +that was a previous suggestion to say +except for students with medical need + + align:start position:0% +except for students with medical need + + + align:start position:0% +except for students with medical need +you could make a non-laptop section the + + align:start position:0% +you could make a non-laptop section the + + + align:start position:0% +you could make a non-laptop section the +default and let students opt out or + + align:start position:0% +default and let students opt out or + + + align:start position:0% +default and let students opt out or +opt in depending on that and essentially + + align:start position:0% +opt in depending on that and essentially + + + align:start position:0% +opt in depending on that and essentially +saying like + + align:start position:0% +saying like + + + align:start position:0% +saying like +the default choice is one uh essentially + + align:start position:0% +the default choice is one uh essentially + + + align:start position:0% +the default choice is one uh essentially +no laptops but you can opt into that + + align:start position:0% +no laptops but you can opt into that + + + align:start position:0% +no laptops but you can opt into that +by emailing the a ta and then use it in + + align:start position:0% +by emailing the a ta and then use it in + + + align:start position:0% +by emailing the a ta and then use it in +a certain section uh + + align:start position:0% +a certain section uh + + + align:start position:0% +a certain section uh +we'll talk about in the problems in a + + align:start position:0% +we'll talk about in the problems in a + + + align:start position:0% +we'll talk about in the problems in a +little bit why that might be a good idea + + align:start position:0% +little bit why that might be a good idea + + + align:start position:0% +little bit why that might be a good idea +you could also set up an active choice + + align:start position:0% +you could also set up an active choice + + + align:start position:0% +you could also set up an active choice +between the laptop and the no laptop + + align:start position:0% +between the laptop and the no laptop + + + align:start position:0% +between the laptop and the no laptop +sections so here's the educational + + align:start position:0% +sections so here's the educational + + + align:start position:0% +sections so here's the educational +interventions the the evidence and + + align:start position:0% +interventions the the evidence and + + + align:start position:0% +interventions the the evidence and +there's very clear evidence from various + + align:start position:0% +there's very clear evidence from various + + + align:start position:0% +there's very clear evidence from various +settings that shows that laptops in + + align:start position:0% +settings that shows that laptops in + + + align:start position:0% +settings that shows that laptops in +class are not good for learning + + align:start position:0% +class are not good for learning + + + align:start position:0% +class are not good for learning +on average there's a very nice article + + align:start position:0% +on average there's a very nice article + + + align:start position:0% +on average there's a very nice article +by susan + + align:start position:0% +by susan + + + align:start position:0% +by susan +donarski in the new york times he'll put + + align:start position:0% +donarski in the new york times he'll put + + + align:start position:0% +donarski in the new york times he'll put +this this online as well that you can + + align:start position:0% +this this online as well that you can + + + align:start position:0% +this this online as well that you can +read + + align:start position:0% +read + + + align:start position:0% +read +but essentially one of these studies is + + align:start position:0% +but essentially one of these studies is + + + align:start position:0% +but essentially one of these studies is +a randomized control trial that um + + align:start position:0% +a randomized control trial that um + + + align:start position:0% +a randomized control trial that um +mit a grad student a former mit grad + + align:start position:0% +mit a grad student a former mit grad + + + align:start position:0% +mit a grad student a former mit grad +student had done + + align:start position:0% +student had done + + + align:start position:0% +student had done +in an intro econ class this is carter + + align:start position:0% +in an intro econ class this is carter + + + align:start position:0% +in an intro econ class this is carter +adal and essentially what they find is + + align:start position:0% +adal and essentially what they find is + + + align:start position:0% +adal and essentially what they find is +that allowing computers in class reduced + + align:start position:0% +that allowing computers in class reduced + + + align:start position:0% +that allowing computers in class reduced +test scores by 0.18 standard deviations + + align:start position:0% +test scores by 0.18 standard deviations + + + align:start position:0% +test scores by 0.18 standard deviations +that's quite a large + + align:start position:0% +that's quite a large + + + align:start position:0% +that's quite a large +number that's essentially saying they + + align:start position:0% +number that's essentially saying they + + + align:start position:0% +number that's essentially saying they +didn't randomize across classes like + + align:start position:0% +didn't randomize across classes like + + + align:start position:0% +didn't randomize across classes like +at the classroom level whether they + + align:start position:0% +at the classroom level whether they + + + align:start position:0% +at the classroom level whether they +allowed laptops in class or not + + align:start position:0% +allowed laptops in class or not + + + align:start position:0% +allowed laptops in class or not +interestingly they found negative + + align:start position:0% +interestingly they found negative + + + align:start position:0% +interestingly they found negative +effects both of like unconstrained + + align:start position:0% +effects both of like unconstrained + + + align:start position:0% +effects both of like unconstrained +laptops like + + align:start position:0% +laptops like + + + align:start position:0% +laptops like +any laptop use but also the flat tablet + + align:start position:0% +any laptop use but also the flat tablet + + + align:start position:0% +any laptop use but also the flat tablet +solutions so even the flat tablet + + align:start position:0% +solutions so even the flat tablet + + + align:start position:0% +solutions so even the flat tablet +solution was worse than sort of the note + + align:start position:0% +solution was worse than sort of the note + + + align:start position:0% +solution was worse than sort of the note +taking + + align:start position:0% +taking + + + align:start position:0% +taking +which pen and paper um you know and + + align:start position:0% +which pen and paper um you know and + + + align:start position:0% +which pen and paper um you know and +there's a bunch of evidence that sort of + + align:start position:0% +there's a bunch of evidence that sort of + + + align:start position:0% +there's a bunch of evidence that sort of +shows that + + align:start position:0% +shows that + + + align:start position:0% +shows that +so in this class what we're going to + + align:start position:0% +so in this class what we're going to + + + align:start position:0% +so in this class what we're going to +have is sort of a version of opt-in + + align:start position:0% +have is sort of a version of opt-in + + + align:start position:0% +have is sort of a version of opt-in +policy which is there's going to be a + + align:start position:0% +policy which is there's going to be a + + + align:start position:0% +policy which is there's going to be a +laptop + + align:start position:0% +laptop + + + align:start position:0% +laptop +section starting next class which is + + align:start position:0% +section starting next class which is + + + align:start position:0% +section starting next class which is +going to be on the front and one side of + + align:start position:0% +going to be on the front and one side of + + + align:start position:0% +going to be on the front and one side of +the class + + align:start position:0% +the class + + + align:start position:0% +the class +the reason being we're trying to sort of + + align:start position:0% +the reason being we're trying to sort of + + + align:start position:0% +the reason being we're trying to sort of +minimize externalities + + align:start position:0% +minimize externalities + + + align:start position:0% +minimize externalities +uh it's in the front not in the back um + + align:start position:0% +uh it's in the front not in the back um + + + align:start position:0% +uh it's in the front not in the back um +the reason being that + + align:start position:0% +the reason being that + + + align:start position:0% +the reason being that +if you're in the very back then there's + + align:start position:0% +if you're in the very back then there's + + + align:start position:0% +if you're in the very back then there's +no supervision i'll i guess ask some uh + + align:start position:0% +no supervision i'll i guess ask some uh + + + align:start position:0% +no supervision i'll i guess ask some uh +tas to sit sort of like in the back if + + align:start position:0% +tas to sit sort of like in the back if + + + align:start position:0% +tas to sit sort of like in the back if +there's too much uh + + align:start position:0% +there's too much uh + + + align:start position:0% +there's too much uh +other activities going on maybe there + + align:start position:0% +other activities going on maybe there + + + align:start position:0% +other activities going on maybe there +won't be a laptop section um + + align:start position:0% +won't be a laptop section um + + + align:start position:0% +won't be a laptop section um +anymore anyway there will be sort of + + align:start position:0% +anymore anyway there will be sort of + + + align:start position:0% +anymore anyway there will be sort of +conservations about that and the problem + + align:start position:0% +conservations about that and the problem + + + align:start position:0% +conservations about that and the problem +said + + align:start position:0% +said + + + align:start position:0% +said +but the point of all of that is to say + + align:start position:0% +but the point of all of that is to say + + + align:start position:0% +but the point of all of that is to say +if you just had the standard economic + + align:start position:0% +if you just had the standard economic + + + align:start position:0% +if you just had the standard economic +considerations you would make certain + + align:start position:0% +considerations you would make certain + + + align:start position:0% +considerations you would make certain +policies um + + align:start position:0% +policies um + + + align:start position:0% +policies um +on very sort of simple considerations by + + align:start position:0% +on very sort of simple considerations by + + + align:start position:0% +on very sort of simple considerations by +missing important facts + + align:start position:0% +missing important facts + + + align:start position:0% +missing important facts +and that might be sort of the + + align:start position:0% +and that might be sort of the + + + align:start position:0% +and that might be sort of the +psychological externality might be the + + align:start position:0% +psychological externality might be the + + + align:start position:0% +psychological externality might be the +self-control problems + + align:start position:0% +self-control problems + + + align:start position:0% +self-control problems +the overestimation of people's ability + + align:start position:0% +the overestimation of people's ability + + + align:start position:0% +the overestimation of people's ability +to multitask and so on and so forth + + align:start position:0% +to multitask and so on and so forth + + + align:start position:0% +to multitask and so on and so forth +and all of those things might sort of + + align:start position:0% +and all of those things might sort of + + + align:start position:0% +and all of those things might sort of +like interfere with people's optimal + + align:start position:0% +like interfere with people's optimal + + + align:start position:0% +like interfere with people's optimal +choices + + align:start position:0% +choices + + + align:start position:0% +choices +and that that makes certain more + + align:start position:0% +and that that makes certain more + + + align:start position:0% +and that that makes certain more +paternalistic policies uh + + align:start position:0% +paternalistic policies uh + + + align:start position:0% +paternalistic policies uh +potentially more promising but again + + align:start position:0% +potentially more promising but again + + + align:start position:0% +potentially more promising but again +in the problem said you'll you'll think + + align:start position:0% +in the problem said you'll you'll think + + + align:start position:0% +in the problem said you'll you'll think +about some of these um uh solutions + + align:start position:0% +about some of these um uh solutions + + + align:start position:0% +about some of these um uh solutions +any questions on the laptops yes i might + + align:start position:0% +any questions on the laptops yes i might + + + align:start position:0% +any questions on the laptops yes i might +be thinking of a different study but it + + align:start position:0% +be thinking of a different study but it + + + align:start position:0% +be thinking of a different study but it +is the same one it i thought that in + + align:start position:0% +is the same one it i thought that in + + + align:start position:0% +is the same one it i thought that in +their other classes they + + align:start position:0% +their other classes they + + + align:start position:0% +their other classes they +previously were not like allowed to use + + align:start position:0% +previously were not like allowed to use + + + align:start position:0% +previously were not like allowed to use +laptops so + + align:start position:0% +laptops so + + + align:start position:0% +laptops so +it might be that they had not optimized + + align:start position:0% +it might be that they had not optimized + + + align:start position:0% +it might be that they had not optimized +themselves for + + align:start position:0% +themselves for + + + align:start position:0% +themselves for +laptop usage during class that's + + align:start position:0% +laptop usage during class that's + + + align:start position:0% +laptop usage during class that's +interesting uh + + align:start position:0% +interesting uh + + + align:start position:0% +interesting uh +so i think there are several studies + + align:start position:0% +so i think there are several studies + + + align:start position:0% +so i think there are several studies +that show that um i don't know the + + align:start position:0% +that show that um i don't know the + + + align:start position:0% +that show that um i don't know the +details on + + align:start position:0% +details on + + + align:start position:0% +details on +that uh but if you can send that to me + + align:start position:0% +that uh but if you can send that to me + + + align:start position:0% +that uh but if you can send that to me +i'm happy to + + align:start position:0% +i'm happy to + + + align:start position:0% +i'm happy to +to just look at that and reconsider i + + align:start position:0% +to just look at that and reconsider i + + + align:start position:0% +to just look at that and reconsider i +think my my view overall is that sort of + + align:start position:0% +think my my view overall is that sort of + + + align:start position:0% +think my my view overall is that sort of +the the existing evidence essentially + + align:start position:0% +the the existing evidence essentially + + + align:start position:0% +the the existing evidence essentially +shows laptops + + align:start position:0% +shows laptops + + + align:start position:0% +shows laptops +are bad since i'm interested in your uh + + align:start position:0% +are bad since i'm interested in your uh + + + align:start position:0% +are bad since i'm interested in your uh +learning um um and that's what i go with + + align:start position:0% +learning um um and that's what i go with + + + align:start position:0% +learning um um and that's what i go with +but i'm happy to be um to be educated + + align:start position:0% +but i'm happy to be um to be educated + + + align:start position:0% +but i'm happy to be um to be educated +um i'll try and put the slides online + + align:start position:0% +um i'll try and put the slides online + + + align:start position:0% +um i'll try and put the slides online +um i was the night before in case you + + align:start position:0% +um i was the night before in case you + + + align:start position:0% +um i was the night before in case you +want to print them out or look at them + + align:start position:0% +want to print them out or look at them + + + align:start position:0% +want to print them out or look at them +or whatever during class + + align:start position:0% +or whatever during class + + + align:start position:0% +or whatever during class +i'm um you're welcome um to do that + + align:start position:0% +i'm um you're welcome um to do that + + + align:start position:0% +i'm um you're welcome um to do that +okay so then let me tell you very + + align:start position:0% +okay so then let me tell you very + + + align:start position:0% +okay so then let me tell you very +briefly about like um + + align:start position:0% +briefly about like um + + + align:start position:0% +briefly about like um +uh different topics of the class and + + align:start position:0% +uh different topics of the class and + + + align:start position:0% +uh different topics of the class and +what we're gonna + + align:start position:0% +what we're gonna + + + align:start position:0% +what we're gonna +cover so first we're gonna have an + + align:start position:0% +cover so first we're gonna have an + + + align:start position:0% +cover so first we're gonna have an +introduction uh and overview + + align:start position:0% +introduction uh and overview + + + align:start position:0% +introduction uh and overview +today's introduction lecture the + + align:start position:0% +today's introduction lecture the + + + align:start position:0% +today's introduction lecture the +overview um will be on wednesday we'll + + align:start position:0% +overview um will be on wednesday we'll + + + align:start position:0% +overview um will be on wednesday we'll +show a cover kind of like + + align:start position:0% +show a cover kind of like + + + align:start position:0% +show a cover kind of like +providing an overview what the different + + align:start position:0% +providing an overview what the different + + + align:start position:0% +providing an overview what the different +topics are and how to think about them + + align:start position:0% +topics are and how to think about them + + + align:start position:0% +topics are and how to think about them +and what evidence do we actually have + + align:start position:0% +and what evidence do we actually have + + + align:start position:0% +and what evidence do we actually have +so i was kind of like a little bit hand + + align:start position:0% +so i was kind of like a little bit hand + + + align:start position:0% +so i was kind of like a little bit hand +wavy in a sense of like showing you lots + + align:start position:0% +wavy in a sense of like showing you lots + + + align:start position:0% +wavy in a sense of like showing you lots +of like + + align:start position:0% +of like + + + align:start position:0% +of like +flashy pictures of people misbehaving + + align:start position:0% +flashy pictures of people misbehaving + + + align:start position:0% +flashy pictures of people misbehaving +but in fact um you know i'm going to + + align:start position:0% +but in fact um you know i'm going to + + + align:start position:0% +but in fact um you know i'm going to +show you some more sort of rigorous + + align:start position:0% +show you some more sort of rigorous + + + align:start position:0% +show you some more sort of rigorous +evidence that we have that in fact + + align:start position:0% +evidence that we have that in fact + + + align:start position:0% +evidence that we have that in fact +uh some of the assumptions of the um + + align:start position:0% +uh some of the assumptions of the um + + + align:start position:0% +uh some of the assumptions of the um +classical + + align:start position:0% +classical + + + align:start position:0% +classical +model are violated and sort of like how + + align:start position:0% +model are violated and sort of like how + + + align:start position:0% +model are violated and sort of like how +we think about them and how we might + + align:start position:0% +we think about them and how we might + + + align:start position:0% +we think about them and how we might +sort of incorporate them into economics + + align:start position:0% +sort of incorporate them into economics + + + align:start position:0% +sort of incorporate them into economics +so that's going to be an overview on + + align:start position:0% +so that's going to be an overview on + + + align:start position:0% +so that's going to be an overview on +wednesday + + align:start position:0% +wednesday + + + align:start position:0% +wednesday +then we're going to talk a lot about + + align:start position:0% +then we're going to talk a lot about + + + align:start position:0% +then we're going to talk a lot about +preferences you can think about + + align:start position:0% +preferences you can think about + + + align:start position:0% +preferences you can think about +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +when people make choices there's a + + align:start position:0% +when people make choices there's a + + + align:start position:0% +when people make choices there's a +utility function and sort of + + align:start position:0% +utility function and sort of + + + align:start position:0% +utility function and sort of +one set of behavioral economics issues + + align:start position:0% +one set of behavioral economics issues + + + align:start position:0% +one set of behavioral economics issues +or + + align:start position:0% +or + + + align:start position:0% +or +changes to the utility function this + + align:start position:0% +changes to the utility function this + + + align:start position:0% +changes to the utility function this +might be time preferences and people's + + align:start position:0% +might be time preferences and people's + + + align:start position:0% +might be time preferences and people's +self-control + + align:start position:0% +self-control + + + align:start position:0% +self-control +which we already discussed it might be + + align:start position:0% +which we already discussed it might be + + + align:start position:0% +which we already discussed it might be +risk preferences how people think about + + align:start position:0% +risk preferences how people think about + + + align:start position:0% +risk preferences how people think about +risk or they think about gains and + + align:start position:0% +risk or they think about gains and + + + align:start position:0% +risk or they think about gains and +losses and how their preferences are + + align:start position:0% +losses and how their preferences are + + + align:start position:0% +losses and how their preferences are +reference dependent + + align:start position:0% +reference dependent + + + align:start position:0% +reference dependent +this is what um a student was saying + + align:start position:0% +this is what um a student was saying + + + align:start position:0% +this is what um a student was saying +earlier about like + + align:start position:0% +earlier about like + + + align:start position:0% +earlier about like +how you evaluate something might it + + align:start position:0% +how you evaluate something might it + + + align:start position:0% +how you evaluate something might it +depend a lot on your expectation of that + + align:start position:0% +depend a lot on your expectation of that + + + align:start position:0% +depend a lot on your expectation of that +outcome + + align:start position:0% +outcome + + + align:start position:0% +outcome +as opposed to just the outcome itself + + align:start position:0% +as opposed to just the outcome itself + + + align:start position:0% +as opposed to just the outcome itself +uh let me talk quite a bit about social + + align:start position:0% +uh let me talk quite a bit about social + + + align:start position:0% +uh let me talk quite a bit about social +preferences this is sort of like how + + align:start position:0% +preferences this is sort of like how + + + align:start position:0% +preferences this is sort of like how +much we + + align:start position:0% +much we + + + align:start position:0% +much we +uh uh how much we weigh others um + + align:start position:0% +uh uh how much we weigh others um + + + align:start position:0% +uh uh how much we weigh others um +utility uh in our youtube our utility + + align:start position:0% +utility uh in our youtube our utility + + + align:start position:0% +utility uh in our youtube our utility +function or their consumption and our + + align:start position:0% +function or their consumption and our + + + align:start position:0% +function or their consumption and our +utility function + + align:start position:0% +utility function + + + align:start position:0% +utility function +uh we'll do some experiments in class um + + align:start position:0% +uh we'll do some experiments in class um + + + align:start position:0% +uh we'll do some experiments in class um +on that which which + + align:start position:0% +on that which which + + + align:start position:0% +on that which which +should be a lot of fun and then discuss + + align:start position:0% +should be a lot of fun and then discuss + + + align:start position:0% +should be a lot of fun and then discuss +various issues about a how much people + + align:start position:0% +various issues about a how much people + + + align:start position:0% +various issues about a how much people +care about others and how they're + + align:start position:0% +care about others and how they're + + + align:start position:0% +care about others and how they're +affected by others behavior and social + + align:start position:0% +affected by others behavior and social + + + align:start position:0% +affected by others behavior and social +influences so that's kind of like the + + align:start position:0% +influences so that's kind of like the + + + align:start position:0% +influences so that's kind of like the +first half of the class broadly about + + align:start position:0% +first half of the class broadly about + + + align:start position:0% +first half of the class broadly about +like + + align:start position:0% +like + + + align:start position:0% +like +changes in people's then preferences + + align:start position:0% +changes in people's then preferences + + + align:start position:0% +changes in people's then preferences +going to talk more about beliefs + + align:start position:0% +going to talk more about beliefs + + + align:start position:0% +going to talk more about beliefs +broadly speaking and sort of people's + + align:start position:0% +broadly speaking and sort of people's + + + align:start position:0% +broadly speaking and sort of people's +how people + + align:start position:0% +how people + + + align:start position:0% +how people +view information in the world you talk a + + align:start position:0% +view information in the world you talk a + + + align:start position:0% +view information in the world you talk a +little about emotions what's called + + align:start position:0% +little about emotions what's called + + + align:start position:0% +little about emotions what's called +projection and attribution bias + + align:start position:0% +projection and attribution bias + + + align:start position:0% +projection and attribution bias +these are issues about for example when + + align:start position:0% +these are issues about for example when + + + align:start position:0% +these are issues about for example when +people are hungry + + align:start position:0% +people are hungry + + + align:start position:0% +people are hungry +or tired they might make quite different + + align:start position:0% +or tired they might make quite different + + + align:start position:0% +or tired they might make quite different +choices + + align:start position:0% +choices + + + align:start position:0% +choices +um and and so that might affect their + + align:start position:0% +um and and so that might affect their + + + align:start position:0% +um and and so that might affect their +preferences + + align:start position:0% +preferences + + + align:start position:0% +preferences +but it might also affect their their + + align:start position:0% +but it might also affect their their + + + align:start position:0% +but it might also affect their their +beliefs in some sense if you think about + + align:start position:0% +beliefs in some sense if you think about + + + align:start position:0% +beliefs in some sense if you think about +how you're going to behave if you're + + align:start position:0% +how you're going to behave if you're + + + align:start position:0% +how you're going to behave if you're +hungry right now it's very hard for you + + align:start position:0% +hungry right now it's very hard for you + + + align:start position:0% +hungry right now it's very hard for you +to believe or + + align:start position:0% +to believe or + + + align:start position:0% +to believe or +think about like that you're not might + + align:start position:0% +think about like that you're not might + + + align:start position:0% +think about like that you're not might +not be hungry in the future this is sort + + align:start position:0% +not be hungry in the future this is sort + + + align:start position:0% +not be hungry in the future this is sort +of the classical example of + + align:start position:0% +of the classical example of + + + align:start position:0% +of the classical example of +shopping on an empty stomach um there's + + align:start position:0% +shopping on an empty stomach um there's + + + align:start position:0% +shopping on an empty stomach um there's +lots of different applications of that + + align:start position:0% +lots of different applications of that + + + align:start position:0% +lots of different applications of that +it's like people buy convertibles when + + align:start position:0% +it's like people buy convertibles when + + + align:start position:0% +it's like people buy convertibles when +it's sunny um and then return them when + + align:start position:0% +it's sunny um and then return them when + + + align:start position:0% +it's sunny um and then return them when +it rains + + align:start position:0% +it rains + + + align:start position:0% +it rains +but there's also much more serious + + align:start position:0% +but there's also much more serious + + + align:start position:0% +but there's also much more serious +issues in particular things like + + align:start position:0% +issues in particular things like + + + align:start position:0% +issues in particular things like +depression for example when people are + + align:start position:0% +depression for example when people are + + + align:start position:0% +depression for example when people are +depressed it's very hard for them to + + align:start position:0% +depressed it's very hard for them to + + + align:start position:0% +depressed it's very hard for them to +think about + + align:start position:0% +think about + + + align:start position:0% +think about +how it might feel when they're not + + align:start position:0% +how it might feel when they're not + + + align:start position:0% +how it might feel when they're not +depressed anymore in the future + + align:start position:0% +depressed anymore in the future + + + align:start position:0% +depressed anymore in the future +so we'll talk about sort of production + + align:start position:0% +so we'll talk about sort of production + + + align:start position:0% +so we'll talk about sort of production +and attribution bytes which is kind of + + align:start position:0% +and attribution bytes which is kind of + + + align:start position:0% +and attribution bytes which is kind of +these biases and how to think about + + align:start position:0% +these biases and how to think about + + + align:start position:0% +these biases and how to think about +people's + + align:start position:0% +people's + + + align:start position:0% +people's +states of the world we talk about + + align:start position:0% +states of the world we talk about + + + align:start position:0% +states of the world we talk about +limited attention that people sort of + + align:start position:0% +limited attention that people sort of + + + align:start position:0% +limited attention that people sort of +don't pay attention to certain things in + + align:start position:0% +don't pay attention to certain things in + + + align:start position:0% +don't pay attention to certain things in +the world and sort of how that might + + align:start position:0% +the world and sort of how that might + + + align:start position:0% +the world and sort of how that might +affect people's behavior + + align:start position:0% +affect people's behavior + + + align:start position:0% +affect people's behavior +how we might sort of exploit that + + align:start position:0% +how we might sort of exploit that + + + align:start position:0% +how we might sort of exploit that +potentially for taxing them or how we + + align:start position:0% +potentially for taxing them or how we + + + align:start position:0% +potentially for taxing them or how we +might sort of direct their attention to + + align:start position:0% +might sort of direct their attention to + + + align:start position:0% +might sort of direct their attention to +certain things and might improve their + + align:start position:0% +certain things and might improve their + + + align:start position:0% +certain things and might improve their +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +similarly then we talk about beliefs and + + align:start position:0% +similarly then we talk about beliefs and + + + align:start position:0% +similarly then we talk about beliefs and +learning this is kind of like + + align:start position:0% +learning this is kind of like + + + align:start position:0% +learning this is kind of like +how what information do they have + + align:start position:0% +how what information do they have + + + align:start position:0% +how what information do they have +available a you know how they + + align:start position:0% +available a you know how they + + + align:start position:0% +available a you know how they +update uh their beliefs when they get + + align:start position:0% +update uh their beliefs when they get + + + align:start position:0% +update uh their beliefs when they get +information and are they able to process + + align:start position:0% +information and are they able to process + + + align:start position:0% +information and are they able to process +information well + + align:start position:0% +information well + + + align:start position:0% +information well +b is the demand for information do + + align:start position:0% +b is the demand for information do + + + align:start position:0% +b is the demand for information do +people get utility from beliefs this is + + align:start position:0% +people get utility from beliefs this is + + + align:start position:0% +people get utility from beliefs this is +what i was talking about like + + align:start position:0% +what i was talking about like + + + align:start position:0% +what i was talking about like +health behaviors other health + + align:start position:0% +health behaviors other health + + + align:start position:0% +health behaviors other health +information where people might have + + align:start position:0% +information where people might have + + + align:start position:0% +information where people might have +motivated beliefs in the sense that like + + align:start position:0% +motivated beliefs in the sense that like + + + align:start position:0% +motivated beliefs in the sense that like +they like to + + align:start position:0% +they like to + + + align:start position:0% +they like to +believe certain things uh um + + align:start position:0% +believe certain things uh um + + + align:start position:0% +believe certain things uh um +when in fact they're not true in part + + align:start position:0% +when in fact they're not true in part + + + align:start position:0% +when in fact they're not true in part +because it makes them happy or in part + + align:start position:0% +because it makes them happy or in part + + + align:start position:0% +because it makes them happy or in part +because they want to be right about + + align:start position:0% +because they want to be right about + + + align:start position:0% +because they want to be right about +something + + align:start position:0% +something + + + align:start position:0% +something +or their party or whatever uh you'll + + align:start position:0% +or their party or whatever uh you'll + + + align:start position:0% +or their party or whatever uh you'll +talk a little about mental accounting + + align:start position:0% +talk a little about mental accounting + + + align:start position:0% +talk a little about mental accounting +which is like + + align:start position:0% +which is like + + + align:start position:0% +which is like +people tend to sort of narrowly bracket + + align:start position:0% +people tend to sort of narrowly bracket + + + align:start position:0% +people tend to sort of narrowly bracket +their choices they might sort of have + + align:start position:0% +their choices they might sort of have + + + align:start position:0% +their choices they might sort of have +certain accounts in their behavior and + + align:start position:0% +certain accounts in their behavior and + + + align:start position:0% +certain accounts in their behavior and +decide sort of separately + + align:start position:0% +decide sort of separately + + + align:start position:0% +decide sort of separately +as opposed to aggregating their behavior + + align:start position:0% +as opposed to aggregating their behavior + + + align:start position:0% +as opposed to aggregating their behavior +as a whole + + align:start position:0% +as a whole + + + align:start position:0% +as a whole +and that sort of issue that's less + + align:start position:0% +and that sort of issue that's less + + + align:start position:0% +and that sort of issue that's less +research but quite interesting overall + + align:start position:0% +research but quite interesting overall + + + align:start position:0% +research but quite interesting overall +then we're going to move towards sort of + + align:start position:0% +then we're going to move towards sort of + + + align:start position:0% +then we're going to move towards sort of +more radical deviations if you want from + + align:start position:0% +more radical deviations if you want from + + + align:start position:0% +more radical deviations if you want from +the standard model which is + + align:start position:0% +the standard model which is + + + align:start position:0% +the standard model which is +things like malleability and + + align:start position:0% +things like malleability and + + + align:start position:0% +things like malleability and +inaccessibility of preferences which is + + align:start position:0% +inaccessibility of preferences which is + + + align:start position:0% +inaccessibility of preferences which is +to say + + align:start position:0% +to say + + + align:start position:0% +to say +people might not actually know what they + + align:start position:0% +people might not actually know what they + + + align:start position:0% +people might not actually know what they +want they might not even understand what + + align:start position:0% +want they might not even understand what + + + align:start position:0% +want they might not even understand what +their preferences are + + align:start position:0% +their preferences are + + + align:start position:0% +their preferences are +or their preferences are easily + + align:start position:0% +or their preferences are easily + + + align:start position:0% +or their preferences are easily +manipulable i can sort of like make you + + align:start position:0% +manipulable i can sort of like make you + + + align:start position:0% +manipulable i can sort of like make you +choose a or b + + align:start position:0% +choose a or b + + + align:start position:0% +choose a or b +or b or a versus b or b versus a + + align:start position:0% +or b or a versus b or b versus a + + + align:start position:0% +or b or a versus b or b versus a +depending on what kind of situation i + + align:start position:0% +depending on what kind of situation i + + + align:start position:0% +depending on what kind of situation i +put you in + + align:start position:0% +put you in + + + align:start position:0% +put you in +and you might not even notice that i'm + + align:start position:0% +and you might not even notice that i'm + + + align:start position:0% +and you might not even notice that i'm +doing that um and in fact + + align:start position:0% +doing that um and in fact + + + align:start position:0% +doing that um and in fact +and that makes things a lot trickier + + align:start position:0% +and that makes things a lot trickier + + + align:start position:0% +and that makes things a lot trickier +because then in some sense it's much + + align:start position:0% +because then in some sense it's much + + + align:start position:0% +because then in some sense it's much +harder to sort of say + + align:start position:0% +harder to sort of say + + + align:start position:0% +harder to sort of say +should the government or any sort of + + align:start position:0% +should the government or any sort of + + + align:start position:0% +should the government or any sort of +other policymaker choose a or b + + align:start position:0% +other policymaker choose a or b + + + align:start position:0% +other policymaker choose a or b +if we don't even know what people's + + align:start position:0% +if we don't even know what people's + + + align:start position:0% +if we don't even know what people's +preferences are people don't even know + + align:start position:0% +preferences are people don't even know + + + align:start position:0% +preferences are people don't even know +what their own preferences are + + align:start position:0% +what their own preferences are + + + align:start position:0% +what their own preferences are +we're going to talk about happiness and + + align:start position:0% +we're going to talk about happiness and + + + align:start position:0% +we're going to talk about happiness and +mental health this kind of broadly + + align:start position:0% +mental health this kind of broadly + + + align:start position:0% +mental health this kind of broadly +speaking what makes people happy and can + + align:start position:0% +speaking what makes people happy and can + + + align:start position:0% +speaking what makes people happy and can +we think about that in particular sort + + align:start position:0% +we think about that in particular sort + + + align:start position:0% +we think about that in particular sort +of like financial choices and others + + align:start position:0% +of like financial choices and others + + + align:start position:0% +of like financial choices and others +i'll tell you a little bit about some of + + align:start position:0% +i'll tell you a little bit about some of + + + align:start position:0% +i'll tell you a little bit about some of +the work on mental health that i have + + align:start position:0% +the work on mental health that i have + + + align:start position:0% +the work on mental health that i have +been + + align:start position:0% +been + + + align:start position:0% +been +doing thinking about kind of like how + + align:start position:0% +doing thinking about kind of like how + + + align:start position:0% +doing thinking about kind of like how +mental health might affect economic + + align:start position:0% +mental health might affect economic + + + align:start position:0% +mental health might affect economic +behaviors and choices and in part how + + align:start position:0% +behaviors and choices and in part how + + + align:start position:0% +behaviors and choices and in part how +people's demand for mental health + + align:start position:0% +people's demand for mental health + + + align:start position:0% +people's demand for mental health +interventions + + align:start position:0% +interventions + + + align:start position:0% +interventions +might be shaped by influences of others + + align:start position:0% +might be shaped by influences of others + + + align:start position:0% +might be shaped by influences of others +uh we're going to talk about gender and + + align:start position:0% +uh we're going to talk about gender and + + + align:start position:0% +uh we're going to talk about gender and +racial discrimination um which sometimes + + align:start position:0% +racial discrimination um which sometimes + + + align:start position:0% +racial discrimination um which sometimes +there's sort of + + align:start position:0% +there's sort of + + + align:start position:0% +there's sort of +classical and neoclassical models of + + align:start position:0% +classical and neoclassical models of + + + align:start position:0% +classical and neoclassical models of +discrimination + + align:start position:0% +discrimination + + + align:start position:0% +discrimination +when we in particular think about sort + + align:start position:0% +when we in particular think about sort + + + align:start position:0% +when we in particular think about sort +of issues of discriminations that are + + align:start position:0% +of issues of discriminations that are + + + align:start position:0% +of issues of discriminations that are +sort of not + + align:start position:0% +sort of not + + + align:start position:0% +sort of not +uh rational in the sense of like uh + + align:start position:0% +uh rational in the sense of like uh + + + align:start position:0% +uh rational in the sense of like uh +think about like unfair in some sense um + + align:start position:0% +think about like unfair in some sense um + + + align:start position:0% +think about like unfair in some sense um +discrimination + + align:start position:0% +discrimination + + + align:start position:0% +discrimination +um finally going to talk about sort of + + align:start position:0% +um finally going to talk about sort of + + + align:start position:0% +um finally going to talk about sort of +policy and paternalism + + align:start position:0% +policy and paternalism + + + align:start position:0% +policy and paternalism +uh one broad issue is about and this + + align:start position:0% +uh one broad issue is about and this + + + align:start position:0% +uh one broad issue is about and this +goes back to malleability and + + align:start position:0% +goes back to malleability and + + + align:start position:0% +goes back to malleability and +inaccessibility of of preferences which + + align:start position:0% +inaccessibility of of preferences which + + + align:start position:0% +inaccessibility of of preferences which +is + + align:start position:0% +is + + + align:start position:0% +is +essentially ways in which choices can be + + align:start position:0% +essentially ways in which choices can be + + + align:start position:0% +essentially ways in which choices can be +affected through frames defaults and + + align:start position:0% +affected through frames defaults and + + + align:start position:0% +affected through frames defaults and +nudges assumptions that say + + align:start position:0% +nudges assumptions that say + + + align:start position:0% +nudges assumptions that say +i can manipulate your choice + + align:start position:0% +i can manipulate your choice + + + align:start position:0% +i can manipulate your choice +architecture in certain ways that make + + align:start position:0% +architecture in certain ways that make + + + align:start position:0% +architecture in certain ways that make +you choose certain things + + align:start position:0% +you choose certain things + + + align:start position:0% +you choose certain things +uh you know i might sort of send you + + align:start position:0% +uh you know i might sort of send you + + + align:start position:0% +uh you know i might sort of send you +letters to do your taxes i can sort of + + align:start position:0% +letters to do your taxes i can sort of + + + align:start position:0% +letters to do your taxes i can sort of +like + + align:start position:0% +like + + + align:start position:0% +like +frame certain or set certain defaults + + align:start position:0% +frame certain or set certain defaults + + + align:start position:0% +frame certain or set certain defaults +for + + align:start position:0% +for + + + align:start position:0% +for +organ donations or for uh savings + + align:start position:0% +organ donations or for uh savings + + + align:start position:0% +organ donations or for uh savings +choices and the like + + align:start position:0% +choices and the like + + + align:start position:0% +choices and the like +and that might have profound effects on + + align:start position:0% +and that might have profound effects on + + + align:start position:0% +and that might have profound effects on +people's behavior + + align:start position:0% +people's behavior + + + align:start position:0% +people's behavior +uh once we go through that in the sense + + align:start position:0% +uh once we go through that in the sense + + + align:start position:0% +uh once we go through that in the sense +of like showing you some evidence that + + align:start position:0% +of like showing you some evidence that + + + align:start position:0% +of like showing you some evidence that +people + + align:start position:0% +people + + + align:start position:0% +people +it's possible to do that we're going to + + align:start position:0% +it's possible to do that we're going to + + + align:start position:0% +it's possible to do that we're going to +talk a little bit about policy and + + align:start position:0% +talk a little bit about policy and + + + align:start position:0% +talk a little bit about policy and +paternalism in a sense of like say + + align:start position:0% +paternalism in a sense of like say + + + align:start position:0% +paternalism in a sense of like say +okay now if i know i can change your + + align:start position:0% +okay now if i know i can change your + + + align:start position:0% +okay now if i know i can change your +behavior in certain ways + + align:start position:0% +behavior in certain ways + + + align:start position:0% +behavior in certain ways +what kinds of policies should we do and + + align:start position:0% +what kinds of policies should we do and + + + align:start position:0% +what kinds of policies should we do and +should we in fact do that + + align:start position:0% +should we in fact do that + + + align:start position:0% +should we in fact do that +or you know should we tax people should + + align:start position:0% +or you know should we tax people should + + + align:start position:0% +or you know should we tax people should +we set certain frames and defaults + + align:start position:0% +we set certain frames and defaults + + + align:start position:0% +we set certain frames and defaults +and you know i'll be potentially making + + align:start position:0% +and you know i'll be potentially making + + + align:start position:0% +and you know i'll be potentially making +some people worse off while making some + + align:start position:0% +some people worse off while making some + + + align:start position:0% +some people worse off while making some +people better off by doing these kinds + + align:start position:0% +people better off by doing these kinds + + + align:start position:0% +people better off by doing these kinds +of + + align:start position:0% +of + + + align:start position:0% +of +policies there's often also some ethical + + align:start position:0% +policies there's often also some ethical + + + align:start position:0% +policies there's often also some ethical +issues + + align:start position:0% +issues + + + align:start position:0% +issues +associated with that and then finally i + + align:start position:0% +associated with that and then finally i + + + align:start position:0% +associated with that and then finally i +talk about poverty this is sort of + + align:start position:0% +talk about poverty this is sort of + + + align:start position:0% +talk about poverty this is sort of +mostly the research + + align:start position:0% +mostly the research + + + align:start position:0% +mostly the research +that i do and thinking about sort of + + align:start position:0% +that i do and thinking about sort of + + + align:start position:0% +that i do and thinking about sort of +poverty issues through the lens of of + + align:start position:0% +poverty issues through the lens of of + + + align:start position:0% +poverty issues through the lens of of +psychology again i'll tell you a little + + align:start position:0% +psychology again i'll tell you a little + + + align:start position:0% +psychology again i'll tell you a little +bit about the the work i do myself + + align:start position:0% +bit about the the work i do myself + + + align:start position:0% +bit about the the work i do myself +um partially to talk a little bit about + + align:start position:0% +um partially to talk a little bit about + + + align:start position:0% +um partially to talk a little bit about +so how + + align:start position:0% +so how + + + align:start position:0% +so how +financial constraints are just thinking + + align:start position:0% +financial constraints are just thinking + + + align:start position:0% +financial constraints are just thinking +about money affects people's behavior + + align:start position:0% +about money affects people's behavior + + + align:start position:0% +about money affects people's behavior +and then second how other issues related + + align:start position:0% +and then second how other issues related + + + align:start position:0% +and then second how other issues related +to poverty might + + align:start position:0% +to poverty might + + + align:start position:0% +to poverty might +shape people's choices + + align:start position:0% + + + + align:start position:0% + +decision making and their sort of labor + + align:start position:0% +decision making and their sort of labor + + + align:start position:0% +decision making and their sort of labor +market outcomes earnings and so on + + align:start position:0% +market outcomes earnings and so on + + + align:start position:0% +market outcomes earnings and so on +and whether it's potentially something + + align:start position:0% +and whether it's potentially something + + + align:start position:0% +and whether it's potentially something +that you might want to call a + + align:start position:0% +that you might want to call a + + + align:start position:0% +that you might want to call a +psychological or behavioral + + align:start position:0% +psychological or behavioral + + + align:start position:0% +psychological or behavioral +poverty trap any questions on these + + align:start position:0% +poverty trap any questions on these + + + align:start position:0% +poverty trap any questions on these +topics + + align:start position:0% + + + + align:start position:0% + +okay so then readings for next time this + + align:start position:0% +okay so then readings for next time this + + + align:start position:0% +okay so then readings for next time this +is wednesday please read + + align:start position:0% +is wednesday please read + + + align:start position:0% +is wednesday please read +um there's a paper on the course website + + align:start position:0% +um there's a paper on the course website + + + align:start position:0% +um there's a paper on the course website +um by matthew raven who is one of sort + + align:start position:0% +um by matthew raven who is one of sort + + + align:start position:0% +um by matthew raven who is one of sort +of like the + + align:start position:0% +of like the + + + align:start position:0% +of like the +uh all-stars in behavioral economics + + align:start position:0% +uh all-stars in behavioral economics + + + align:start position:0% +uh all-stars in behavioral economics +uh 20 years ago he already wrote a very + + align:start position:0% +uh 20 years ago he already wrote a very + + + align:start position:0% +uh 20 years ago he already wrote a very +useful perspective on psychology and + + align:start position:0% +useful perspective on psychology and + + + align:start position:0% +useful perspective on psychology and +economics that sort of discusses a lot + + align:start position:0% +economics that sort of discusses a lot + + + align:start position:0% +economics that sort of discusses a lot +of the issues of + + align:start position:0% +of the issues of + + + align:start position:0% +of the issues of +behavioral economics how to think about + + align:start position:0% +behavioral economics how to think about + + + align:start position:0% +behavioral economics how to think about +that um again read sections one and two + + align:start position:0% +that um again read sections one and two + + + align:start position:0% +that um again read sections one and two +we're not going to sort of test you + + align:start position:0% +we're not going to sort of test you + + + align:start position:0% +we're not going to sort of test you +specifically on like very specific + + align:start position:0% +specifically on like very specific + + + align:start position:0% +specifically on like very specific +things but you should sort of be able to + + align:start position:0% +things but you should sort of be able to + + + align:start position:0% +things but you should sort of be able to +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +uh remember at least roughly what's + + align:start position:0% +uh remember at least roughly what's + + + align:start position:0% +uh remember at least roughly what's +what's in that paper \ No newline at end of file diff --git a/jtOxRPQDuJs.txt b/jtOxRPQDuJs.txt new file mode 100644 index 0000000000000000000000000000000000000000..80d1a146813169afccb8aa953770073d3e999238 --- /dev/null +++ b/jtOxRPQDuJs.txt @@ -0,0 +1,459 @@ +align:start position:0% + +let's consider a one-dimensional motion + + align:start position:0% +let's consider a one-dimensional motion + + + align:start position:0% +let's consider a one-dimensional motion +that has a non uniform acceleration what + + align:start position:0% +that has a non uniform acceleration what + + + align:start position:0% +that has a non uniform acceleration what +we'd like to do is explore how do you + + align:start position:0% +we'd like to do is explore how do you + + + align:start position:0% +we'd like to do is explore how do you +differentiate position functions to get + + align:start position:0% +differentiate position functions to get + + + align:start position:0% +differentiate position functions to get +philosophy functions to get acceleration + + align:start position:0% +philosophy functions to get acceleration + + + align:start position:0% +philosophy functions to get acceleration +function so what we're going to consider + + align:start position:0% +function so what we're going to consider + + + align:start position:0% +function so what we're going to consider +is a rocket so I'm going to choose a + + align:start position:0% +is a rocket so I'm going to choose a + + + align:start position:0% +is a rocket so I'm going to choose a +coordinate system Y and here's my rocket + + align:start position:0% +coordinate system Y and here's my rocket + + + align:start position:0% +coordinate system Y and here's my rocket +and I have the function y of T and I'll + + align:start position:0% +and I have the function y of T and I'll + + + align:start position:0% +and I have the function y of T and I'll +have a J hat direction but this will be + + align:start position:0% +have a J hat direction but this will be + + + align:start position:0% +have a J hat direction but this will be +a one-dimensional motion now I want to + + align:start position:0% +a one-dimensional motion now I want to + + + align:start position:0% +a one-dimensional motion now I want to +express while the rocket is thrusting + + align:start position:0% +express while the rocket is thrusting + + + align:start position:0% +express while the rocket is thrusting +upwards and the engine is burning we can + + align:start position:0% +upwards and the engine is burning we can + + + align:start position:0% +upwards and the engine is burning we can +describe a function y of T to be equal + + align:start position:0% +describe a function y of T to be equal + + + align:start position:0% +describe a function y of T to be equal +to one-half a constant a naught minus + + align:start position:0% +to one-half a constant a naught minus + + + align:start position:0% +to one-half a constant a naught minus +the gravitational acceleration times T + + align:start position:0% +the gravitational acceleration times T + + + align:start position:0% +the gravitational acceleration times T +squared and we're going to have a + + align:start position:0% +squared and we're going to have a + + + align:start position:0% +squared and we're going to have a +separate term here which is minus 1 over + + align:start position:0% +separate term here which is minus 1 over + + + align:start position:0% +separate term here which is minus 1 over +30 and you'll see where this 30 comes in + + align:start position:0% +30 and you'll see where this 30 comes in + + + align:start position:0% +30 and you'll see where this 30 comes in +as we start to differentiate same + + align:start position:0% +as we start to differentiate same + + + align:start position:0% +as we start to differentiate same +constant a naught T to the sixth over T + + align:start position:0% +constant a naught T to the sixth over T + + + align:start position:0% +constant a naught T to the sixth over T +naught to the fourth now in this + + align:start position:0% +naught to the fourth now in this + + + align:start position:0% +naught to the fourth now in this +expression a naught is bigger than G and + + align:start position:0% +expression a naught is bigger than G and + + + align:start position:0% +expression a naught is bigger than G and +also this is only true this holds for + + align:start position:0% +also this is only true this holds for + + + align:start position:0% +also this is only true this holds for +the time interval 0 less than or equal + + align:start position:0% +the time interval 0 less than or equal + + + align:start position:0% +the time interval 0 less than or equal +to t less than T naught and at time T + + align:start position:0% +to t less than T naught and at time T + + + align:start position:0% +to t less than T naught and at time T +equals to T naught the engine shuts off + + align:start position:0% +equals to T naught the engine shuts off + + + align:start position:0% +equals to T naught the engine shuts off +and at that moment our expectation will + + align:start position:0% +and at that moment our expectation will + + + align:start position:0% +and at that moment our expectation will +be that the Y component of the + + align:start position:0% +be that the Y component of the + + + align:start position:0% +be that the Y component of the +acceleration should just be minus G for + + align:start position:0% +acceleration should just be minus G for + + + align:start position:0% +acceleration should just be minus G for +T greater than T naught so now let's + + align:start position:0% +T greater than T naught so now let's + + + align:start position:0% +T greater than T naught so now let's +calculate the acceleration as the + + align:start position:0% +calculate the acceleration as the + + + align:start position:0% +calculate the acceleration as the +velocity and the position as functions + + align:start position:0% +velocity and the position as functions + + + align:start position:0% +velocity and the position as functions +of time so the velocity in each case + + align:start position:0% +of time so the velocity in each case + + + align:start position:0% +of time so the velocity in each case +we're going to use the polynomial rule + + align:start position:0% +we're going to use the polynomial rule + + + align:start position:0% +we're going to use the polynomial rule +so the Y component of the velocity is + + align:start position:0% +so the Y component of the velocity is + + + align:start position:0% +so the Y component of the velocity is +just the different derivative of T + + align:start position:0% +just the different derivative of T + + + align:start position:0% +just the different derivative of T +squared which is just 2t and so we get a + + align:start position:0% +squared which is just 2t and so we get a + + + align:start position:0% +squared which is just 2t and so we get a +naught minus G times T and when we + + align:start position:0% +naught minus G times T and when we + + + align:start position:0% +naught minus G times T and when we +differentiate T to the sixth the 6 over + + align:start position:0% +differentiate T to the sixth the 6 over + + + align:start position:0% +differentiate T to the sixth the 6 over +30 gives us a factor 1 over 5 so we have + + align:start position:0% +30 gives us a factor 1 over 5 so we have + + + align:start position:0% +30 gives us a factor 1 over 5 so we have +minus 1 over 5 times a naught T to the + + align:start position:0% +minus 1 over 5 times a naught T to the + + + align:start position:0% +minus 1 over 5 times a naught T to the +fifth + + align:start position:0% +fifth + + + align:start position:0% +fifth +over T not to the fourth and this is a + + align:start position:0% +over T not to the fourth and this is a + + + align:start position:0% +over T not to the fourth and this is a +combination of a linear term and a term + + align:start position:0% +combination of a linear term and a term + + + align:start position:0% +combination of a linear term and a term +that is decreasing by this T to the + + align:start position:0% +that is decreasing by this T to the + + + align:start position:0% +that is decreasing by this T to the +fifth factor and finally we now take the + + align:start position:0% +fifth factor and finally we now take the + + + align:start position:0% +fifth factor and finally we now take the +next derivative a Y of T which is d dy + + align:start position:0% +next derivative a Y of T which is d dy + + + align:start position:0% +next derivative a Y of T which is d dy +DT I'll just keep functions of T but we + + align:start position:0% +DT I'll just keep functions of T but we + + + align:start position:0% +DT I'll just keep functions of T but we +don't really need that and when we + + align:start position:0% +don't really need that and when we + + + align:start position:0% +don't really need that and when we +differentiate here we get a naught minus + + align:start position:0% +differentiate here we get a naught minus + + + align:start position:0% +differentiate here we get a naught minus +G now you see the 5s are cancelling and + + align:start position:0% +G now you see the 5s are cancelling and + + + align:start position:0% +G now you see the 5s are cancelling and +we have minus a naught T to the fourth + + align:start position:0% +we have minus a naught T to the fourth + + + align:start position:0% +we have minus a naught T to the fourth +over T naught to the fourth now at time + + align:start position:0% +over T naught to the fourth now at time + + + align:start position:0% +over T naught to the fourth now at time +T equals T naught what do we have well a + + align:start position:0% +T equals T naught what do we have well a + + + align:start position:0% +T equals T naught what do we have well a +Y at T equals T naught this is just a + + align:start position:0% +Y at T equals T naught this is just a + + + align:start position:0% +Y at T equals T naught this is just a +factor minus a naught those cancel and + + align:start position:0% +factor minus a naught those cancel and + + + align:start position:0% +factor minus a naught those cancel and +we get minus G which is what we expected \ No newline at end of file diff --git a/k3AiUhwHQ28.txt b/k3AiUhwHQ28.txt new file mode 100644 index 0000000000000000000000000000000000000000..fed166d593bb7b68cb96616f428e21596b195fdb --- /dev/null +++ b/k3AiUhwHQ28.txt @@ -0,0 +1,8331 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so he graciously agreed to come today + + align:start position:0% +so he graciously agreed to come today + + + align:start position:0% +so he graciously agreed to come today +and so everything is ready then and in + + align:start position:0% +and so everything is ready then and in + + + align:start position:0% +and so everything is ready then and in +your cutoff is like 155 yeah + + align:start position:0% + + + + align:start position:0% + +why is there + + align:start position:0% + + + + align:start position:0% + +you know somebody changed the resolution + + align:start position:0% +you know somebody changed the resolution + + + align:start position:0% +you know somebody changed the resolution +it seems but that's fine doesn't doesn't + + align:start position:0% +it seems but that's fine doesn't doesn't + + + align:start position:0% +it seems but that's fine doesn't doesn't +bother us so I'm gonna tell you about + + align:start position:0% +bother us so I'm gonna tell you about + + + align:start position:0% +bother us so I'm gonna tell you about +let's say one of the most ancient + + align:start position:0% +let's say one of the most ancient + + + align:start position:0% +let's say one of the most ancient +optimization methods much simpler than + + align:start position:0% +optimization methods much simpler than + + + align:start position:0% +optimization methods much simpler than +in fact the more advanced methods you + + align:start position:0% +in fact the more advanced methods you + + + align:start position:0% +in fact the more advanced methods you +have already seen in class and + + align:start position:0% +have already seen in class and + + + align:start position:0% +have already seen in class and +interestingly this more ancient method + + align:start position:0% +interestingly this more ancient method + + + align:start position:0% +interestingly this more ancient method +remains the method for training + + align:start position:0% +remains the method for training + + + align:start position:0% +remains the method for training +large-scale machine learning systems and + + align:start position:0% +large-scale machine learning systems and + + + align:start position:0% +large-scale machine learning systems and +so there's a little bit of history + + align:start position:0% +so there's a little bit of history + + + align:start position:0% +so there's a little bit of history +around that I'm not gonna go too much + + align:start position:0% +around that I'm not gonna go too much + + + align:start position:0% +around that I'm not gonna go too much +into the history but the bottom line + + align:start position:0% +into the history but the bottom line + + + align:start position:0% +into the history but the bottom line +which probably Gil has also mentioned to + + align:start position:0% +which probably Gil has also mentioned to + + + align:start position:0% +which probably Gil has also mentioned to +you in class that at least for large + + align:start position:0% +you in class that at least for large + + + align:start position:0% +you in class that at least for large +data science problems in the end stuff + + align:start position:0% +data science problems in the end stuff + + + align:start position:0% +data science problems in the end stuff +reduces to solving an optimization + + align:start position:0% +reduces to solving an optimization + + + align:start position:0% +reduces to solving an optimization +problem and in current times these + + align:start position:0% +problem and in current times these + + + align:start position:0% +problem and in current times these +optimization problems are pretty large + + align:start position:0% +optimization problems are pretty large + + + align:start position:0% +optimization problems are pretty large +so people actually started liking stuff + + align:start position:0% +so people actually started liking stuff + + + align:start position:0% +so people actually started liking stuff +like gradient descent which was invented + + align:start position:0% +like gradient descent which was invented + + + align:start position:0% +like gradient descent which was invented +by Cauchy back in the day and this is + + align:start position:0% +by Cauchy back in the day and this is + + + align:start position:0% +by Cauchy back in the day and this is +how I'm writing the abstract problem and + + align:start position:0% +how I'm writing the abstract problem and + + + align:start position:0% +how I'm writing the abstract problem and +what I wanna see is okay is it fitting + + align:start position:0% +what I wanna see is okay is it fitting + + + align:start position:0% +what I wanna see is okay is it fitting +on the page this is my implementation in + + align:start position:0% +on the page this is my implementation in + + + align:start position:0% +on the page this is my implementation in +MATLAB of gradient descent just to set + + align:start position:0% +MATLAB of gradient descent just to set + + + align:start position:0% +MATLAB of gradient descent just to set +the stage that you know this stuff + + align:start position:0% +the stage that you know this stuff + + + align:start position:0% +the stage that you know this stuff +really looks simple you've already seen + + align:start position:0% +really looks simple you've already seen + + + align:start position:0% +really looks simple you've already seen +gradient descent and today essentially + + align:start position:0% +gradient descent and today essentially + + + align:start position:0% +gradient descent and today essentially +in a nutshell what really changes in + + align:start position:0% +in a nutshell what really changes in + + + align:start position:0% +in a nutshell what really changes in +this implementation of gradient descent + + align:start position:0% +this implementation of gradient descent + + + align:start position:0% +this implementation of gradient descent +today is this part that's it + + align:start position:0% +today is this part that's it + + + align:start position:0% +today is this part that's it +so you've seen gradient descent I'm only + + align:start position:0% +so you've seen gradient descent I'm only + + + align:start position:0% +so you've seen gradient descent I'm only +going to change this one line and the + + align:start position:0% +going to change this one line and the + + + align:start position:0% +going to change this one line and the +change of that one line surprisingly is + + align:start position:0% +change of that one line surprisingly is + + + align:start position:0% +change of that one line surprisingly is +driving you know all the deep learning + + align:start position:0% +driving you know all the deep learning + + + align:start position:0% +driving you know all the deep learning +toolboxes and all of large scale machine + + align:start position:0% +toolboxes and all of large scale machine + + + align:start position:0% +toolboxes and all of large scale machine +learning etc this is an + + align:start position:0% +learning etc this is an + + + align:start position:0% +learning etc this is an +oversimplification but morally that's it + + align:start position:0% +oversimplification but morally that's it + + + align:start position:0% +oversimplification but morally that's it +so let's look at what's happening so I + + align:start position:0% +so let's look at what's happening so I + + + align:start position:0% +so let's look at what's happening so I +will become very concrete pretty soon + + align:start position:0% +will become very concrete pretty soon + + + align:start position:0% +will become very concrete pretty soon +but abstractly what I want you to look + + align:start position:0% +but abstractly what I want you to look + + + align:start position:0% +but abstractly what I want you to look +at is the + + align:start position:0% +at is the + + + align:start position:0% +at is the +kinds of optimization problems we are + + align:start position:0% +kinds of optimization problems we are + + + align:start position:0% +kinds of optimization problems we are +solving in machine learning and I'll + + align:start position:0% +solving in machine learning and I'll + + + align:start position:0% +solving in machine learning and I'll +give you very concrete examples of these + + align:start position:0% +give you very concrete examples of these + + + align:start position:0% +give you very concrete examples of these +optimization problems so that you can + + align:start position:0% +optimization problems so that you can + + + align:start position:0% +optimization problems so that you can +relate to them better but I'm just + + align:start position:0% +relate to them better but I'm just + + + align:start position:0% +relate to them better but I'm just +writing this as the key topic that all + + align:start position:0% +writing this as the key topic that all + + + align:start position:0% +writing this as the key topic that all +the optimization problems that I'm going + + align:start position:0% +the optimization problems that I'm going + + + align:start position:0% +the optimization problems that I'm going +to talk about today they look like that + + align:start position:0% +to talk about today they look like that + + + align:start position:0% +to talk about today they look like that +we're trying to find an x over a cost + + align:start position:0% +we're trying to find an x over a cost + + + align:start position:0% +we're trying to find an x over a cost +function where the cost function can be + + align:start position:0% +function where the cost function can be + + + align:start position:0% +function where the cost function can be +written as a sum in modern day machine + + align:start position:0% +written as a sum in modern day machine + + + align:start position:0% +written as a sum in modern day machine +learning parlance these are also called + + align:start position:0% +learning parlance these are also called + + + align:start position:0% +learning parlance these are also called +finite sum problems in case you run into + + align:start position:0% +finite sum problems in case you run into + + + align:start position:0% +finite sum problems in case you run into +that term and this is called finite + + align:start position:0% +that term and this is called finite + + + align:start position:0% +that term and this is called finite +because n is finite here in pure + + align:start position:0% +because n is finite here in pure + + + align:start position:0% +because n is finite here in pure +optimization Theory parlance n can + + align:start position:0% +optimization Theory parlance n can + + + align:start position:0% +optimization Theory parlance n can +actually go to infinity and then they + + align:start position:0% +actually go to infinity and then they + + + align:start position:0% +actually go to infinity and then they +are called stochastic optimization + + align:start position:0% +are called stochastic optimization + + + align:start position:0% +are called stochastic optimization +problems just for terminology if while + + align:start position:0% +problems just for terminology if while + + + align:start position:0% +problems just for terminology if while +searching the internet you run into some + + align:start position:0% +searching the internet you run into some + + + align:start position:0% +searching the internet you run into some +such terminology so you kind of know + + align:start position:0% +such terminology so you kind of know + + + align:start position:0% +such terminology so you kind of know +what it means so here is our set up in + + align:start position:0% +what it means so here is our set up in + + + align:start position:0% +what it means so here is our set up in +machine learning we have a bunch of + + align:start position:0% +machine learning we have a bunch of + + + align:start position:0% +machine learning we have a bunch of +training data ok on this slide I am + + align:start position:0% +training data ok on this slide I am + + + align:start position:0% +training data ok on this slide I am +calling x1 through xn these are the + + align:start position:0% +calling x1 through xn these are the + + + align:start position:0% +calling x1 through xn these are the +training data the raw features later + + align:start position:0% +training data the raw features later + + + align:start position:0% +training data the raw features later +actually I stopped writing X for them + + align:start position:0% +actually I stopped writing X for them + + + align:start position:0% +actually I stopped writing X for them +and write them with the letter A but + + align:start position:0% +and write them with the letter A but + + + align:start position:0% +and write them with the letter A but +hopefully that's okay so x1 through xn + + align:start position:0% +hopefully that's okay so x1 through xn + + + align:start position:0% +hopefully that's okay so x1 through xn +these could be just raw images for + + align:start position:0% +these could be just raw images for + + + align:start position:0% +these could be just raw images for +instance in imagenet or some other image + + align:start position:0% +instance in imagenet or some other image + + + align:start position:0% +instance in imagenet or some other image +data set there could be text documents + + align:start position:0% +data set there could be text documents + + + align:start position:0% +data set there could be text documents +they could be anything y1 through yn in + + align:start position:0% +they could be anything y1 through yn in + + + align:start position:0% +they could be anything y1 through yn in +classical machine learning think of them + + align:start position:0% +classical machine learning think of them + + + align:start position:0% +classical machine learning think of them +as plus minus 1 labels cat not cat or in + + align:start position:0% +as plus minus 1 labels cat not cat or in + + + align:start position:0% +as plus minus 1 labels cat not cat or in +a regression setup as some real number + + align:start position:0% +a regression setup as some real number + + + align:start position:0% +a regression setup as some real number +so that's a training data we have D + + align:start position:0% +so that's a training data we have D + + + align:start position:0% +so that's a training data we have D +dimensional raw vectors and of those and + + align:start position:0% +dimensional raw vectors and of those and + + + align:start position:0% +dimensional raw vectors and of those and +we have corresponding labels which can + + align:start position:0% +we have corresponding labels which can + + + align:start position:0% +we have corresponding labels which can +be either plus minus 1 in a + + align:start position:0% +be either plus minus 1 in a + + + align:start position:0% +be either plus minus 1 in a +classification setting or a real number + + align:start position:0% +classification setting or a real number + + + align:start position:0% +classification setting or a real number +in a regression setting it's kind of + + align:start position:0% +in a regression setting it's kind of + + + align:start position:0% +in a regression setting it's kind of +immaterial for my lecture right now so + + align:start position:0% +immaterial for my lecture right now so + + + align:start position:0% +immaterial for my lecture right now so +that's the input and whenever anybody + + align:start position:0% +that's the input and whenever anybody + + + align:start position:0% +that's the input and whenever anybody +says large-scale machine learning what + + align:start position:0% +says large-scale machine learning what + + + align:start position:0% +says large-scale machine learning what +do we really mean + + align:start position:0% +do we really mean + + + align:start position:0% +do we really mean +what we mean is that both N and D can be + + align:start position:0% +what we mean is that both N and D can be + + + align:start position:0% +what we mean is that both N and D can be +large so what does that mean in words + + align:start position:0% +large so what does that mean in words + + + align:start position:0% +large so what does that mean in words +there n is the number of training data + + align:start position:0% +there n is the number of training data + + + align:start position:0% +there n is the number of training data +points so n could be these days what + + align:start position:0% +points so n could be these days what + + + align:start position:0% +points so n could be these days what +million ten million hundred million + + align:start position:0% +million ten million hundred million + + + align:start position:0% +million ten million hundred million +depends on how big computers and data + + align:start position:0% +depends on how big computers and data + + + align:start position:0% +depends on how big computers and data +sets you got so n can be huge d the + + align:start position:0% +sets you got so n can be huge d the + + + align:start position:0% +sets you got so n can be huge d the +dimensionality the vectors that we are + + align:start position:0% +dimensionality the vectors that we are + + + align:start position:0% +dimensionality the vectors that we are +working with the raw vectors that can + + align:start position:0% +working with the raw vectors that can + + + align:start position:0% +working with the raw vectors that can +also be pretty large think if X is an + + align:start position:0% +also be pretty large think if X is an + + + align:start position:0% +also be pretty large think if X is an +image if it's a megapixel image wow + + align:start position:0% +image if it's a megapixel image wow + + + align:start position:0% +image if it's a megapixel image wow +these like a million already if you are + + align:start position:0% +these like a million already if you are + + + align:start position:0% +these like a million already if you are +somebody like kriti o or Facebook or + + align:start position:0% +somebody like kriti o or Facebook or + + + align:start position:0% +somebody like kriti o or Facebook or +Google and you're serving web + + align:start position:0% +Google and you're serving web + + + align:start position:0% +Google and you're serving web +advertisements D these are the features + + align:start position:0% +advertisements D these are the features + + + align:start position:0% +advertisements D these are the features +could be like in 700 million even a + + align:start position:0% +could be like in 700 million even a + + + align:start position:0% +could be like in 700 million even a +billion where they encode all sorts of + + align:start position:0% +billion where they encode all sorts of + + + align:start position:0% +billion where they encode all sorts of +nasty stuff and information they collect + + align:start position:0% +nasty stuff and information they collect + + + align:start position:0% +nasty stuff and information they collect +about you as users so so many nasty + + align:start position:0% +about you as users so so many nasty + + + align:start position:0% +about you as users so so many nasty +things they can collect right so DNN are + + align:start position:0% +things they can collect right so DNN are + + + align:start position:0% +things they can collect right so DNN are +huge and it's because both D and n are + + align:start position:0% +huge and it's because both D and n are + + + align:start position:0% +huge and it's because both D and n are +huge we are interested in thinking of + + align:start position:0% +huge we are interested in thinking of + + + align:start position:0% +huge we are interested in thinking of +optimization methods for large-scale + + align:start position:0% +optimization methods for large-scale + + + align:start position:0% +optimization methods for large-scale +machine learning that can handle such + + align:start position:0% +machine learning that can handle such + + + align:start position:0% +machine learning that can handle such +big dnl and this is driving a lot of + + align:start position:0% +big dnl and this is driving a lot of + + + align:start position:0% +big dnl and this is driving a lot of +research also in theoretical computer + + align:start position:0% +research also in theoretical computer + + + align:start position:0% +research also in theoretical computer +science including the search for sub + + align:start position:0% +science including the search for sub + + + align:start position:0% +science including the search for sub +linear time algorithms in all sorts of + + align:start position:0% +linear time algorithms in all sorts of + + + align:start position:0% +linear time algorithms in all sorts of +data structures in hashing tricks just + + align:start position:0% +data structures in hashing tricks just + + + align:start position:0% +data structures in hashing tricks just +to deal with these two quantities so + + align:start position:0% +to deal with these two quantities so + + + align:start position:0% +to deal with these two quantities so +here is an example super toy example and + + align:start position:0% +here is an example super toy example and + + + align:start position:0% +here is an example super toy example and +I hope really you know by that I can + + align:start position:0% +I hope really you know by that I can + + + align:start position:0% +I hope really you know by that I can +squeeze in a little bit of a proof later + + align:start position:0% +squeeze in a little bit of a proof later + + + align:start position:0% +squeeze in a little bit of a proof later +on towards the end I'll take a vote here + + align:start position:0% +on towards the end I'll take a vote here + + + align:start position:0% +on towards the end I'll take a vote here +in class to see if you are interested + + align:start position:0% +in class to see if you are interested + + + align:start position:0% +in class to see if you are interested +let's look at the most classic question + + align:start position:0% +let's look at the most classic question + + + align:start position:0% +let's look at the most classic question +least squares regression is a matrix of + + align:start position:0% +least squares regression is a matrix of + + + align:start position:0% +least squares regression is a matrix of +observations or sorry measurements B are + + align:start position:0% +observations or sorry measurements B are + + + align:start position:0% +observations or sorry measurements B are +the observations you're trying to solve + + align:start position:0% +the observations you're trying to solve + + + align:start position:0% +the observations you're trying to solve +ax minus B whole square + + align:start position:0% +ax minus B whole square + + + align:start position:0% +ax minus B whole square +of course a linear system of equations + + align:start position:0% +of course a linear system of equations + + + align:start position:0% +of course a linear system of equations +the most classical problem in linear + + align:start position:0% +the most classical problem in linear + + + align:start position:0% +the most classical problem in linear +algebra can also be written like that + + align:start position:0% +algebra can also be written like that + + + align:start position:0% +algebra can also be written like that +let's say this can be expanded hopefully + + align:start position:0% +let's say this can be expanded hopefully + + + align:start position:0% +let's say this can be expanded hopefully +you are comfortable with this norm right + + align:start position:0% +you are comfortable with this norm right + + + align:start position:0% +you are comfortable with this norm right +so x2 square this is just defined as + + align:start position:0% +so x2 square this is just defined as + + + align:start position:0% +so x2 square this is just defined as +that's the definition of that notation + + align:start position:0% +that's the definition of that notation + + + align:start position:0% +that's the definition of that notation +but I'll just write it only once now I + + align:start position:0% +but I'll just write it only once now I + + + align:start position:0% +but I'll just write it only once now I +hope you are fully familiar with that so + + align:start position:0% +hope you are fully familiar with that so + + + align:start position:0% +hope you are fully familiar with that so +by expanding that I managed to write + + align:start position:0% +by expanding that I managed to write + + + align:start position:0% +by expanding that I managed to write +least squares problem in terms of what I + + align:start position:0% +least squares problem in terms of what I + + + align:start position:0% +least squares problem in terms of what I +call the finite sum right so it's just + + align:start position:0% +call the finite sum right so it's just + + + align:start position:0% +call the finite sum right so it's just +going over all the rows in a their end + + align:start position:0% +going over all the rows in a their end + + + align:start position:0% +going over all the rows in a their end +rows let's say so that's the least + + align:start position:0% +rows let's say so that's the least + + + align:start position:0% +rows let's say so that's the least +squares classical least squares problem + + align:start position:0% +squares classical least squares problem + + + align:start position:0% +squares classical least squares problem +it assumes this finite sum form that we + + align:start position:0% +it assumes this finite sum form that we + + + align:start position:0% +it assumes this finite sum form that we +care about another random example + + align:start position:0% +care about another random example + + + align:start position:0% +care about another random example +something called la so maybe you have if + + align:start position:0% +something called la so maybe you have if + + + align:start position:0% +something called la so maybe you have if +anybody of you has played with machine + + align:start position:0% +anybody of you has played with machine + + + align:start position:0% +anybody of you has played with machine +learning statistics toolkits you may + + align:start position:0% +learning statistics toolkits you may + + + align:start position:0% +learning statistics toolkits you may +have seen something called la Sol la Sol + + align:start position:0% +have seen something called la Sol la Sol + + + align:start position:0% +have seen something called la Sol la Sol +is essentially least squares but there's + + align:start position:0% +is essentially least squares but there's + + + align:start position:0% +is essentially least squares but there's +another simple term at the end that + + align:start position:0% +another simple term at the end that + + + align:start position:0% +another simple term at the end that +again looks like F of I support vector + + align:start position:0% +again looks like F of I support vector + + + align:start position:0% +again looks like F of I support vector +machines once over horse of they're + + align:start position:0% +machines once over horse of they're + + + align:start position:0% +machines once over horse of they're +still a workhorse horse of people who + + align:start position:0% +still a workhorse horse of people who + + + align:start position:0% +still a workhorse horse of people who +work with small to medium sized data + + align:start position:0% +work with small to medium sized data + + + align:start position:0% +work with small to medium sized data +deep learning stuff requires huge amount + + align:start position:0% +deep learning stuff requires huge amount + + + align:start position:0% +deep learning stuff requires huge amount +of data if you have small to medium + + align:start position:0% +of data if you have small to medium + + + align:start position:0% +of data if you have small to medium +amount of data logistic regression + + align:start position:0% +amount of data logistic regression + + + align:start position:0% +amount of data logistic regression +support vector machines trees etc this + + align:start position:0% +support vector machines trees etc this + + + align:start position:0% +support vector machines trees etc this +will be a first go to methods they still + + align:start position:0% +will be a first go to methods they still + + + align:start position:0% +will be a first go to methods they still +very widely used these problems are + + align:start position:0% +very widely used these problems are + + + align:start position:0% +very widely used these problems are +again written in terms of a loss over + + align:start position:0% +again written in terms of a loss over + + + align:start position:0% +again written in terms of a loss over +training data so this again has this + + align:start position:0% +training data so this again has this + + + align:start position:0% +training data so this again has this +awesome format which I'll just now + + align:start position:0% +awesome format which I'll just now + + + align:start position:0% +awesome format which I'll just now +record here I may not even need to + + align:start position:0% +record here I may not even need to + + + align:start position:0% +record here I may not even need to +repeat it sometimes I write it with a + + align:start position:0% +repeat it sometimes I write it with a + + + align:start position:0% +repeat it sometimes I write it with a +normalization you may wonder at some + + align:start position:0% +normalization you may wonder at some + + + align:start position:0% +normalization you may wonder at some +point why as that finite sum problem and + + align:start position:0% +point why as that finite sum problem and + + + align:start position:0% +point why as that finite sum problem and +maybe the example that you want it to + + align:start position:0% +maybe the example that you want it to + + + align:start position:0% +maybe the example that you want it to +see is something like that so deep + + align:start position:0% +see is something like that so deep + + + align:start position:0% +see is something like that so deep +neural networks that are very popular + + align:start position:0% +neural networks that are very popular + + + align:start position:0% +neural networks that are very popular +these days they are just yet another + + align:start position:0% +these days they are just yet another + + + align:start position:0% +these days they are just yet another +example of this finite sum problem how + + align:start position:0% +example of this finite sum problem how + + + align:start position:0% +example of this finite sum problem how +are they an example of that so you have + + align:start position:0% +are they an example of that so you have + + + align:start position:0% +are they an example of that so you have +n training data points there's a neural + + align:start position:0% +n training data points there's a neural + + + align:start position:0% +n training data points there's a neural +network loss like cross-entropy or what + + align:start position:0% +network loss like cross-entropy or what + + + align:start position:0% +network loss like cross-entropy or what +have you squared loss cross into any + + align:start position:0% +have you squared loss cross into any + + + align:start position:0% +have you squared loss cross into any +kind of loss why eyes are the labels cat + + align:start position:0% +kind of loss why eyes are the labels cat + + + align:start position:0% +kind of loss why eyes are the labels cat +not cat or whatever or they may be her + + align:start position:0% +not cat or whatever or they may be her + + + align:start position:0% +not cat or whatever or they may be her +multi class + + align:start position:0% +multi class + + + align:start position:0% +multi class +and then you have a transfer function + + align:start position:0% +and then you have a transfer function + + + align:start position:0% +and then you have a transfer function +called a deep neural network which takes + + align:start position:0% +called a deep neural network which takes + + + align:start position:0% +called a deep neural network which takes +raw images as input and generates a + + align:start position:0% +raw images as input and generates a + + + align:start position:0% +raw images as input and generates a +prediction whether this is a dog or not + + align:start position:0% +prediction whether this is a dog or not + + + align:start position:0% +prediction whether this is a dog or not +that whole thing I'm just calling DN n + + align:start position:0% +that whole thing I'm just calling DN n + + + align:start position:0% +that whole thing I'm just calling DN n +so it's a function of a eyes which are + + align:start position:0% +so it's a function of a eyes which are + + + align:start position:0% +so it's a function of a eyes which are +the training data X are the weight + + align:start position:0% +the training data X are the weight + + + align:start position:0% +the training data X are the weight +matrices of the neural network so I'm + + align:start position:0% +matrices of the neural network so I'm + + + align:start position:0% +matrices of the neural network so I'm +just compressed the whole neural network + + align:start position:0% +just compressed the whole neural network + + + align:start position:0% +just compressed the whole neural network +into this notation + + align:start position:0% +into this notation + + + align:start position:0% +into this notation +once again it's nothing but an instance + + align:start position:0% +once again it's nothing but an instance + + + align:start position:0% +once again it's nothing but an instance +of that finite sum so that F I in there + + align:start position:0% +of that finite sum so that F I in there + + + align:start position:0% +of that finite sum so that F I in there +captures the entire neural network + + align:start position:0% +captures the entire neural network + + + align:start position:0% +captures the entire neural network +architecture but mathematically it's + + align:start position:0% +architecture but mathematically it's + + + align:start position:0% +architecture but mathematically it's +still just one particular instance of + + align:start position:0% +still just one particular instance of + + + align:start position:0% +still just one particular instance of +this finite sum problem and in people + + align:start position:0% +this finite sum problem and in people + + + align:start position:0% +this finite sum problem and in people +who do lot of statistics maximum + + align:start position:0% +who do lot of statistics maximum + + + align:start position:0% +who do lot of statistics maximum +likelihood estimation this is log + + align:start position:0% +likelihood estimation this is log + + + align:start position:0% +likelihood estimation this is log +likelihood over n observations we want + + align:start position:0% +likelihood over n observations we want + + + align:start position:0% +likelihood over n observations we want +to maximize log likelihood once again + + align:start position:0% +to maximize log likelihood once again + + + align:start position:0% +to maximize log likelihood once again +just a finite sum so pretty much most of + + align:start position:0% +just a finite sum so pretty much most of + + + align:start position:0% +just a finite sum so pretty much most of +the problems that we are interested in + + align:start position:0% +the problems that we are interested in + + + align:start position:0% +the problems that we are interested in +machine learning and statistics when I + + align:start position:0% +machine learning and statistics when I + + + align:start position:0% +machine learning and statistics when I +write them write them down as an + + align:start position:0% +write them write them down as an + + + align:start position:0% +write them write them down as an +optimization problem they look like this + + align:start position:0% +optimization problem they look like this + + + align:start position:0% +optimization problem they look like this +finite sum problems and that's the + + align:start position:0% +finite sum problems and that's the + + + align:start position:0% +finite sum problems and that's the +reason to develop specialized + + align:start position:0% +reason to develop specialized + + + align:start position:0% +reason to develop specialized +optimization procedures to solve such + + align:start position:0% +optimization procedures to solve such + + + align:start position:0% +optimization procedures to solve such +finite sum problems and that's where SGD + + align:start position:0% +finite sum problems and that's where SGD + + + align:start position:0% +finite sum problems and that's where SGD +comes in ok so that's kind of just the + + align:start position:0% +comes in ok so that's kind of just the + + + align:start position:0% +comes in ok so that's kind of just the +backdrop let's look at now how to go + + align:start position:0% +backdrop let's look at now how to go + + + align:start position:0% +backdrop let's look at now how to go +about solving these problems + + align:start position:0% + + + + align:start position:0% + +so hopefully this iteration is familiar + + align:start position:0% +so hopefully this iteration is familiar + + + align:start position:0% +so hopefully this iteration is familiar +to you gradient descent right ok so just + + align:start position:0% + + + + align:start position:0% + +for notation f of X refers to that + + align:start position:0% +for notation f of X refers to that + + + align:start position:0% +for notation f of X refers to that +entire summation F sub I of X refers to + + align:start position:0% +entire summation F sub I of X refers to + + + align:start position:0% +entire summation F sub I of X refers to +a single component ok so if you were to + + align:start position:0% +a single component ok so if you were to + + + align:start position:0% +a single component ok so if you were to +try to solve that is to minimize this + + align:start position:0% +try to solve that is to minimize this + + + align:start position:0% +try to solve that is to minimize this +cost function neural network SVM + + align:start position:0% +cost function neural network SVM + + + align:start position:0% +cost function neural network SVM +what-have-you using gradient descent + + align:start position:0% +what-have-you using gradient descent + + + align:start position:0% +what-have-you using gradient descent +that's what one iteration would look + + align:start position:0% +that's what one iteration would look + + + align:start position:0% +that's what one iteration would look +like because it's a finite sum gradients + + align:start position:0% +like because it's a finite sum gradients + + + align:start position:0% +like because it's a finite sum gradients +are linear operators + + align:start position:0% +are linear operators + + + align:start position:0% +are linear operators +you know gradient of the sum is the sum + + align:start position:0% +you know gradient of the sum is the sum + + + align:start position:0% +you know gradient of the sum is the sum +of the gradients so that's gradient + + align:start position:0% +of the gradients so that's gradient + + + align:start position:0% +of the gradients so that's gradient +descent for you and now I'll just ask a + + align:start position:0% +descent for you and now I'll just ask a + + + align:start position:0% +descent for you and now I'll just ask a +rhetoric question that if you put + + align:start position:0% +rhetoric question that if you put + + + align:start position:0% +rhetoric question that if you put +yourself in the shoes of you know + + align:start position:0% +yourself in the shoes of you know + + + align:start position:0% +yourself in the shoes of you know +algorithm designers some things that you + + align:start position:0% +algorithm designers some things that you + + + align:start position:0% +algorithm designers some things that you +may want to think about what may you not + + align:start position:0% +may want to think about what may you not + + + align:start position:0% +may want to think about what may you not +like about this iteration given that big + + align:start position:0% +like about this iteration given that big + + + align:start position:0% +like about this iteration given that big +and Big D story that I told you so + + align:start position:0% +and Big D story that I told you so + + + align:start position:0% +and Big D story that I told you so +anybody have any reservations or about + + align:start position:0% +anybody have any reservations or about + + + align:start position:0% +anybody have any reservations or about +drawbacks of this iteration any comments + + align:start position:0% + + + + align:start position:0% + +it's a pretty big sum especially + + align:start position:0% +it's a pretty big sum especially + + + align:start position:0% +it's a pretty big sum especially +anything that is a big drawback and + + align:start position:0% +anything that is a big drawback and + + + align:start position:0% +anything that is a big drawback and +there is that is the prime drawback for + + align:start position:0% +there is that is the prime drawback for + + + align:start position:0% +there is that is the prime drawback for +large scale that n can be huge there can + + align:start position:0% +large scale that n can be huge there can + + + align:start position:0% +large scale that n can be huge there can +be variety of other drawbacks some of + + align:start position:0% +be variety of other drawbacks some of + + + align:start position:0% +be variety of other drawbacks some of +those you may have seen previously if + + align:start position:0% +those you may have seen previously if + + + align:start position:0% +those you may have seen previously if +when people compare whether to do + + align:start position:0% +when people compare whether to do + + + align:start position:0% +when people compare whether to do +gradient or to do Newton etc but for + + align:start position:0% +gradient or to do Newton etc but for + + + align:start position:0% +gradient or to do Newton etc but for +purpose of today for finite sums the big + + align:start position:0% +purpose of today for finite sums the big + + + align:start position:0% +purpose of today for finite sums the big +drawback is computing gradient at a + + align:start position:0% +drawback is computing gradient at a + + + align:start position:0% +drawback is computing gradient at a +single point this is a subscript XK + + align:start position:0% +single point this is a subscript XK + + + align:start position:0% +single point this is a subscript XK +missing there involves computing the + + align:start position:0% +missing there involves computing the + + + align:start position:0% +missing there involves computing the +gradient of that entire sum that sum is + + align:start position:0% +gradient of that entire sum that sum is + + + align:start position:0% +gradient of that entire sum that sum is +huge so getting a single gradient to do + + align:start position:0% +huge so getting a single gradient to do + + + align:start position:0% +huge so getting a single gradient to do +a single step of gradient descent for a + + align:start position:0% +a single step of gradient descent for a + + + align:start position:0% +a single step of gradient descent for a +large data set could take you hours or + + align:start position:0% +large data set could take you hours or + + + align:start position:0% +large data set could take you hours or +days so that's a major drawback but then + + align:start position:0% +days so that's a major drawback but then + + + align:start position:0% +days so that's a major drawback but then +okay if you identify that drawback + + align:start position:0% +okay if you identify that drawback + + + align:start position:0% +okay if you identify that drawback +anybody have any ideas how to counter + + align:start position:0% +anybody have any ideas how to counter + + + align:start position:0% +anybody have any ideas how to counter +that drawback at least say purely from + + align:start position:0% +that drawback at least say purely from + + + align:start position:0% +that drawback at least say purely from +an engineering perspective I heard + + align:start position:0% +an engineering perspective I heard + + + align:start position:0% +an engineering perspective I heard +something + + align:start position:0% + + + + align:start position:0% + +using LexA and a batch of mash lights to + + align:start position:0% +using LexA and a batch of mash lights to + + + align:start position:0% +using LexA and a batch of mash lights to +defend us and maybe somebody else has + + align:start position:0% +defend us and maybe somebody else has + + + align:start position:0% +defend us and maybe somebody else has +essentially the same idea anybody wants + + align:start position:0% +essentially the same idea anybody wants + + + align:start position:0% +essentially the same idea anybody wants +to suggest how to circumvent that big + + align:start position:0% +to suggest how to circumvent that big + + + align:start position:0% +to suggest how to circumvent that big +end stuff in there anything suppose you + + align:start position:0% +end stuff in there anything suppose you + + + align:start position:0% +end stuff in there anything suppose you +can implement in this what would you do + + align:start position:0% + + + + align:start position:0% + +andum sample of the full n so these are + + align:start position:0% +andum sample of the full n so these are + + + align:start position:0% +andum sample of the full n so these are +all excellent ideas and hence you folks + + align:start position:0% +all excellent ideas and hence you folks + + + align:start position:0% +all excellent ideas and hence you folks +in the class have discovered the most + + align:start position:0% +in the class have discovered the most + + + align:start position:0% +in the class have discovered the most +important method for optimizing machine + + align:start position:0% +important method for optimizing machine + + + align:start position:0% +important method for optimizing machine +learning problems sitting here in a few + + align:start position:0% +learning problems sitting here in a few + + + align:start position:0% +learning problems sitting here in a few +moments isn't that great so the part + + align:start position:0% +moments isn't that great so the part + + + align:start position:0% +moments isn't that great so the part +that is missing is of course to make + + align:start position:0% +that is missing is of course to make + + + align:start position:0% +that is missing is of course to make +sense of does this idea work why does it + + align:start position:0% +sense of does this idea work why does it + + + align:start position:0% +sense of does this idea work why does it +work so this idea is really at the heart + + align:start position:0% +work so this idea is really at the heart + + + align:start position:0% +work so this idea is really at the heart +of stochastic gradient descent so let's + + align:start position:0% +of stochastic gradient descent so let's + + + align:start position:0% +of stochastic gradient descent so let's +see I maybe I can show you an example + + align:start position:0% +see I maybe I can show you an example + + + align:start position:0% +see I maybe I can show you an example +actually that I I'll show you a + + align:start position:0% +actually that I I'll show you a + + + align:start position:0% +actually that I I'll show you a +simulation I found on somebody's nice + + align:start position:0% +simulation I found on somebody's nice + + + align:start position:0% +simulation I found on somebody's nice +web page about that so exactly your idea + + align:start position:0% +web page about that so exactly your idea + + + align:start position:0% +web page about that so exactly your idea +just put in slight mathematical notation + + align:start position:0% +just put in slight mathematical notation + + + align:start position:0% +just put in slight mathematical notation +that what if at each iteration we + + align:start position:0% +that what if at each iteration we + + + align:start position:0% +that what if at each iteration we +randomly pick some integer I K out of + + align:start position:0% +randomly pick some integer I K out of + + + align:start position:0% +randomly pick some integer I K out of +the n training data points and and we + + align:start position:0% +the n training data points and and we + + + align:start position:0% +the n training data points and and we +instead just perform this update right + + align:start position:0% +instead just perform this update right + + + align:start position:0% +instead just perform this update right +so you instead of using the full + + align:start position:0% +so you instead of using the full + + + align:start position:0% +so you instead of using the full +gradient you just compute the gradient + + align:start position:0% +gradient you just compute the gradient + + + align:start position:0% +gradient you just compute the gradient +of a single randomly chosen data point + + align:start position:0% +of a single randomly chosen data point + + + align:start position:0% +of a single randomly chosen data point +so what have you done with that one + + align:start position:0% +so what have you done with that one + + + align:start position:0% +so what have you done with that one +iteration is now n times faster if n + + align:start position:0% +iteration is now n times faster if n + + + align:start position:0% +iteration is now n times faster if n +were a million or a billion wow that's + + align:start position:0% +were a million or a billion wow that's + + + align:start position:0% +were a million or a billion wow that's +super fast but why should this work + + align:start position:0% +super fast but why should this work + + + align:start position:0% +super fast but why should this work +right + + align:start position:0% + + + + align:start position:0% + +I mean I could have done many other + + align:start position:0% +I mean I could have done many other + + + align:start position:0% +I mean I could have done many other +things I could have constant I could + + align:start position:0% +things I could have constant I could + + + align:start position:0% +things I could have constant I could +have not done any update and just output + + align:start position:0% +have not done any update and just output + + + align:start position:0% +have not done any update and just output +the zero vector that would take even + + align:start position:0% +the zero vector that would take even + + + align:start position:0% +the zero vector that would take even +lesser time that's also an idea means a + + align:start position:0% +lesser time that's also an idea means a + + + align:start position:0% +lesser time that's also an idea means a +bad idea but it's an idea in the similar + + align:start position:0% +bad idea but it's an idea in the similar + + + align:start position:0% +bad idea but it's an idea in the similar +league I could have done a variety of + + align:start position:0% +league I could have done a variety of + + + align:start position:0% +league I could have done a variety of +other things why would you think that + + align:start position:0% +other things why would you think that + + + align:start position:0% +other things why would you think that +just you know replacing that some with + + align:start position:0% +just you know replacing that some with + + + align:start position:0% +just you know replacing that some with +just one random example may work let's + + align:start position:0% +just one random example may work let's + + + align:start position:0% +just one random example may work let's +see a little bit more about that so of + + align:start position:0% +see a little bit more about that so of + + + align:start position:0% +see a little bit more about that so of +course it's n times faster and the key + + align:start position:0% +course it's n times faster and the key + + + align:start position:0% +course it's n times faster and the key +question for us here right now the + + align:start position:0% +question for us here right now the + + + align:start position:0% +question for us here right now the +scientific question is does this make + + align:start position:0% +scientific question is does this make + + + align:start position:0% +scientific question is does this make +sense it makes great engineering sense + + align:start position:0% +sense it makes great engineering sense + + + align:start position:0% +sense it makes great engineering sense +does it make algorithmic or mathematical + + align:start position:0% +does it make algorithmic or mathematical + + + align:start position:0% +does it make algorithmic or mathematical +sense so this idea of doing stuff in the + + align:start position:0% +sense so this idea of doing stuff in the + + + align:start position:0% +sense so this idea of doing stuff in the +stochastic manner was actually + + align:start position:0% +stochastic manner was actually + + + align:start position:0% +stochastic manner was actually +originally proposed by Robbins in Monro + + align:start position:0% +originally proposed by Robbins in Monro + + + align:start position:0% +originally proposed by Robbins in Monro +somewhere I think around 1951 and that's + + align:start position:0% +somewhere I think around 1951 and that's + + + align:start position:0% +somewhere I think around 1951 and that's +the most advanced method that we are + + align:start position:0% +the most advanced method that we are + + + align:start position:0% +the most advanced method that we are +essentially using currently so I'll show + + align:start position:0% +essentially using currently so I'll show + + + align:start position:0% +essentially using currently so I'll show +you that this idea makes sense but maybe + + align:start position:0% +you that this idea makes sense but maybe + + + align:start position:0% +you that this idea makes sense but maybe +let's first just look at a comparison of + + align:start position:0% +let's first just look at a comparison of + + + align:start position:0% +let's first just look at a comparison of +SGD with gradient descent in this + + align:start position:0% +SGD with gradient descent in this + + + align:start position:0% +SGD with gradient descent in this +simulation so this is that MATLAB code + + align:start position:0% +simulation so this is that MATLAB code + + + align:start position:0% +simulation so this is that MATLAB code +of gradient descent and this is just a + + align:start position:0% +of gradient descent and this is just a + + + align:start position:0% +of gradient descent and this is just a +simulation of gradient descent as you + + align:start position:0% +simulation of gradient descent as you + + + align:start position:0% +simulation of gradient descent as you +pick a different step size that gamma in + + align:start position:0% +pick a different step size that gamma in + + + align:start position:0% +pick a different step size that gamma in +there you move towards the optimum if + + align:start position:0% +there you move towards the optimum if + + + align:start position:0% +there you move towards the optimum if +the step size is small you make many + + align:start position:0% +the step size is small you make many + + + align:start position:0% +the step size is small you make many +small steps progress and you reach there + + align:start position:0% +small steps progress and you reach there + + + align:start position:0% +small steps progress and you reach there +that's for a well-conditioned problem in + + align:start position:0% +that's for a well-conditioned problem in + + + align:start position:0% +that's for a well-conditioned problem in +an ill-conditioned problem it takes you + + align:start position:0% +an ill-conditioned problem it takes you + + + align:start position:0% +an ill-conditioned problem it takes you +even larger in a neural network type + + align:start position:0% +even larger in a neural network type + + + align:start position:0% +even larger in a neural network type +problem which is non convex you have to + + align:start position:0% +problem which is non convex you have to + + + align:start position:0% +problem which is non convex you have to +typically work with smaller step sizes + + align:start position:0% +typically work with smaller step sizes + + + align:start position:0% +typically work with smaller step sizes +and if you take bigger ones you can get + + align:start position:0% +and if you take bigger ones you can get + + + align:start position:0% +and if you take bigger ones you can get +crazy oscillations but that's gradient + + align:start position:0% +crazy oscillations but that's gradient + + + align:start position:0% +crazy oscillations but that's gradient +descent in comparison let's hope that + + align:start position:0% +descent in comparison let's hope that + + + align:start position:0% +descent in comparison let's hope that +this loads correctly well there's even a + + align:start position:0% +this loads correctly well there's even a + + + align:start position:0% +this loads correctly well there's even a +picture of Robbins who's a core + + align:start position:0% +picture of Robbins who's a core + + + align:start position:0% +picture of Robbins who's a core +discoverer of the stochastic gradient + + align:start position:0% +discoverer of the stochastic gradient + + + align:start position:0% +discoverer of the stochastic gradient +method there's a nice simulation that + + align:start position:0% +method there's a nice simulation that + + + align:start position:0% +method there's a nice simulation that +instead of me + + align:start position:0% +instead of me + + + align:start position:0% +instead of me +King that kind of deterministic descent + + align:start position:0% +King that kind of deterministic descent + + + align:start position:0% +King that kind of deterministic descent +after all gradient descent is called + + align:start position:0% +after all gradient descent is called + + + align:start position:0% +after all gradient descent is called +gradient descent at every step it + + align:start position:0% +gradient descent at every step it + + + align:start position:0% +gradient descent at every step it +descends it decreases the cost function + + align:start position:0% +descends it decreases the cost function + + + align:start position:0% +descends it decreases the cost function +stochastic gradient descent is actually + + align:start position:0% +stochastic gradient descent is actually + + + align:start position:0% +stochastic gradient descent is actually +a misnomer at every step it doesn't do + + align:start position:0% +a misnomer at every step it doesn't do + + + align:start position:0% +a misnomer at every step it doesn't do +any descent it does not decrease the + + align:start position:0% +any descent it does not decrease the + + + align:start position:0% +any descent it does not decrease the +cost function so you can see at every + + align:start position:0% +cost function so you can see at every + + + align:start position:0% +cost function so you can see at every +step those are the contours of the cost + + align:start position:0% +step those are the contours of the cost + + + align:start position:0% +step those are the contours of the cost +function sometimes it goes up sometimes + + align:start position:0% +function sometimes it goes up sometimes + + + align:start position:0% +function sometimes it goes up sometimes +it goes down it fluctuates around but it + + align:start position:0% +it goes down it fluctuates around but it + + + align:start position:0% +it goes down it fluctuates around but it +kind of stochastically still seems to be + + align:start position:0% +kind of stochastically still seems to be + + + align:start position:0% +kind of stochastically still seems to be +making progress towards the optimum and + + align:start position:0% +making progress towards the optimum and + + + align:start position:0% +making progress towards the optimum and +stochastic gradient descent because it's + + align:start position:0% +stochastic gradient descent because it's + + + align:start position:0% +stochastic gradient descent because it's +not using exact gradients just working + + align:start position:0% +not using exact gradients just working + + + align:start position:0% +not using exact gradients just working +with these random examples it actually + + align:start position:0% +with these random examples it actually + + + align:start position:0% +with these random examples it actually +is much more sensitive to step sizes and + + align:start position:0% +is much more sensitive to step sizes and + + + align:start position:0% +is much more sensitive to step sizes and +you can see as I increase the step size + + align:start position:0% +you can see as I increase the step size + + + align:start position:0% +you can see as I increase the step size +its behavior this is like actually full + + align:start position:0% +its behavior this is like actually full + + + align:start position:0% +its behavior this is like actually full +simulation for a toy problem so + + align:start position:0% +simulation for a toy problem so + + + align:start position:0% +simulation for a toy problem so +initially so what I want you to notice + + align:start position:0% +initially so what I want you to notice + + + align:start position:0% +initially so what I want you to notice +is let me go through this you know a few + + align:start position:0% +is let me go through this you know a few + + + align:start position:0% +is let me go through this you know a few +times keep looking at what patterns you + + align:start position:0% +times keep looking at what patterns you + + + align:start position:0% +times keep looking at what patterns you +may notice in how that line is + + align:start position:0% +may notice in how that line is + + + align:start position:0% +may notice in how that line is +fluctuating hopefully this is big enough + + align:start position:0% +fluctuating hopefully this is big enough + + + align:start position:0% +fluctuating hopefully this is big enough +for everybody to see okay so this slider + + align:start position:0% +for everybody to see okay so this slider + + + align:start position:0% +for everybody to see okay so this slider +that I'm shifting is just the step size + + align:start position:0% +that I'm shifting is just the step size + + + align:start position:0% +that I'm shifting is just the step size +so let me just remind you in case you + + align:start position:0% +so let me just remind you in case you + + + align:start position:0% +so let me just remind you in case you +forgot the iteration we are running XK + + align:start position:0% +forgot the iteration we are running XK + + + align:start position:0% +forgot the iteration we are running XK +plus 1 is XK minus some it okay okay + + align:start position:0% +plus 1 is XK minus some it okay okay + + + align:start position:0% +plus 1 is XK minus some it okay okay +it's called alpha there times some + + align:start position:0% +it's called alpha there times some + + + align:start position:0% +it's called alpha there times some +randomly chosen data point you compute + + align:start position:0% +randomly chosen data point you compute + + + align:start position:0% +randomly chosen data point you compute +its gradient this is SGD that's what we + + align:start position:0% +its gradient this is SGD that's what we + + + align:start position:0% +its gradient this is SGD that's what we +are running and we threw away tons of + + align:start position:0% +are running and we threw away tons of + + + align:start position:0% +are running and we threw away tons of +information we didn't use the full + + align:start position:0% +information we didn't use the full + + + align:start position:0% +information we didn't use the full +gradient we just using this crude crude + + align:start position:0% +gradient we just using this crude crude + + + align:start position:0% +gradient we just using this crude crude +gradient so this process is very + + align:start position:0% +gradient so this process is very + + + align:start position:0% +gradient so this process is very +sensitive to the other parameter in the + + align:start position:0% +sensitive to the other parameter in the + + + align:start position:0% +sensitive to the other parameter in the +system which is the step size much more + + align:start position:0% +system which is the step size much more + + + align:start position:0% +system which is the step size much more +sensitive than gradient descent in fact + + align:start position:0% +sensitive than gradient descent in fact + + + align:start position:0% +sensitive than gradient descent in fact +and you let's see as I vary the step + + align:start position:0% +and you let's see as I vary the step + + + align:start position:0% +and you let's see as I vary the step +size see if you can notice some parents + + align:start position:0% +size see if you can notice some parents + + + align:start position:0% +size see if you can notice some parents +on how it tries to go towards an optimum + + align:start position:0% + + + + align:start position:0% + +is a zoomed in version also of this + + align:start position:0% +is a zoomed in version also of this + + + align:start position:0% +is a zoomed in version also of this +later here and come to that shortly + + align:start position:0% +later here and come to that shortly + + + align:start position:0% +later here and come to that shortly +again I'll repeat again and then I'll + + align:start position:0% +again I'll repeat again and then I'll + + + align:start position:0% +again I'll repeat again and then I'll +ask you for your observations if you + + align:start position:0% +ask you for your observations if you + + + align:start position:0% +ask you for your observations if you +notice some patterns I don't know if + + align:start position:0% +notice some patterns I don't know if + + + align:start position:0% +notice some patterns I don't know if +they're necessarily apparent you know + + align:start position:0% +they're necessarily apparent you know + + + align:start position:0% +they're necessarily apparent you know +that's the thing with patterns because I + + align:start position:0% +that's the thing with patterns because I + + + align:start position:0% +that's the thing with patterns because I +know the answer so I see the pattern if + + align:start position:0% +know the answer so I see the pattern if + + + align:start position:0% +know the answer so I see the pattern if +you don't know the answer you may or may + + align:start position:0% +you don't know the answer you may or may + + + align:start position:0% +you don't know the answer you may or may +not see the pattern but I want to see if + + align:start position:0% +not see the pattern but I want to see if + + + align:start position:0% +not see the pattern but I want to see if +you actually see the pattern as I move + + align:start position:0% +you actually see the pattern as I move + + + align:start position:0% +you actually see the pattern as I move +change the step size so maybe that was + + align:start position:0% +change the step size so maybe that was + + + align:start position:0% +change the step size so maybe that was +enough simulation anybody have any + + align:start position:0% +enough simulation anybody have any + + + align:start position:0% +enough simulation anybody have any +comments on what kind of pattern you may + + align:start position:0% +comments on what kind of pattern you may + + + align:start position:0% +comments on what kind of pattern you may +have observed any other comments there's + + align:start position:0% +have observed any other comments there's + + + align:start position:0% +have observed any other comments there's +one more interesting thing happening + + align:start position:0% +one more interesting thing happening + + + align:start position:0% +one more interesting thing happening +here which is a very very typical thing + + align:start position:0% +here which is a very very typical thing + + + align:start position:0% +here which is a very very typical thing +for SGD in one of the reasons why people + + align:start position:0% +for SGD in one of the reasons why people + + + align:start position:0% +for SGD in one of the reasons why people +love SGD let me do that once again + + align:start position:0% +love SGD let me do that once again + + + align:start position:0% +love SGD let me do that once again +briefly okay this is tiny step size + + align:start position:0% +briefly okay this is tiny step size + + + align:start position:0% +briefly okay this is tiny step size +almost zero close to zero is not exactly + + align:start position:0% +almost zero close to zero is not exactly + + + align:start position:0% +almost zero close to zero is not exactly +zero so you see what happens for a very + + align:start position:0% +zero so you see what happens for a very + + + align:start position:0% +zero so you see what happens for a very +tiny step size it doesn't look that + + align:start position:0% +tiny step size it doesn't look that + + + align:start position:0% +tiny step size it doesn't look that +stochastic right but that's kind of + + align:start position:0% +stochastic right but that's kind of + + + align:start position:0% +stochastic right but that's kind of +obvious from there if a Takei is very + + align:start position:0% +obvious from there if a Takei is very + + + align:start position:0% +obvious from there if a Takei is very +tiny you'll hardly make any move so + + align:start position:0% +tiny you'll hardly make any move so + + + align:start position:0% +tiny you'll hardly make any move so +things will look very stable and in fact + + align:start position:0% +things will look very stable and in fact + + + align:start position:0% +things will look very stable and in fact +the speed at which stochastic gradient + + align:start position:0% +the speed at which stochastic gradient + + + align:start position:0% +the speed at which stochastic gradient +converges that's why extremely sensitive + + align:start position:0% +converges that's why extremely sensitive + + + align:start position:0% +converges that's why extremely sensitive +to how you pick the step size it's still + + align:start position:0% +to how you pick the step size it's still + + + align:start position:0% +to how you pick the step size it's still +an open research problem to come up with + + align:start position:0% +an open research problem to come up with + + + align:start position:0% +an open research problem to come up with +the best way to pick step sizes okay so + + align:start position:0% +the best way to pick step sizes okay so + + + align:start position:0% +the best way to pick step sizes okay so +it's even though it's simple it doesn't + + align:start position:0% +it's even though it's simple it doesn't + + + align:start position:0% +it's even though it's simple it doesn't +mean it's trivial and as I vary the step + + align:start position:0% +mean it's trivial and as I vary the step + + + align:start position:0% +mean it's trivial and as I vary the step +size okay to make some progress and it + + align:start position:0% +size okay to make some progress and it + + + align:start position:0% +size okay to make some progress and it +goes towards the solution are you know + + align:start position:0% +goes towards the solution are you know + + + align:start position:0% +goes towards the solution are you know +beginning to say that it seems to be + + align:start position:0% +beginning to say that it seems to be + + + align:start position:0% +beginning to say that it seems to be +making a more stable progress in the + + align:start position:0% +making a more stable progress in the + + + align:start position:0% +making a more stable progress in the +beginning and when it comes close to the + + align:start position:0% +beginning and when it comes close to the + + + align:start position:0% +beginning and when it comes close to the +solution it's fluctuating more and the + + align:start position:0% +solution it's fluctuating more and the + + + align:start position:0% +solution it's fluctuating more and the +bigger the step size the amount of + + align:start position:0% +bigger the step size the amount of + + + align:start position:0% +bigger the step size the amount of +fluctuation near the solution is Wilder + + align:start position:0% +fluctuation near the solution is Wilder + + + align:start position:0% +fluctuation near the solution is Wilder +as he noticed back there but one + + align:start position:0% +as he noticed back there but one + + + align:start position:0% +as he noticed back there but one +very interesting thing is more or less + + align:start position:0% +very interesting thing is more or less + + + align:start position:0% +very interesting thing is more or less +constant there is more fluctuation also + + align:start position:0% +constant there is more fluctuation also + + + align:start position:0% +constant there is more fluctuation also +on the outside but you see that the + + align:start position:0% +on the outside but you see that the + + + align:start position:0% +on the outside but you see that the +initial part still seems to be making + + align:start position:0% +initial part still seems to be making + + + align:start position:0% +initial part still seems to be making +pretty good progress and as you come + + align:start position:0% +pretty good progress and as you come + + + align:start position:0% +pretty good progress and as you come +close to the solution it fluctuates more + + align:start position:0% +close to the solution it fluctuates more + + + align:start position:0% +close to the solution it fluctuates more +and that is a very principally typical + + align:start position:0% +and that is a very principally typical + + + align:start position:0% +and that is a very principally typical +behavior of stochastic gradient descent + + align:start position:0% +behavior of stochastic gradient descent + + + align:start position:0% +behavior of stochastic gradient descent +that in the beginning it makes rapid + + align:start position:0% +that in the beginning it makes rapid + + + align:start position:0% +that in the beginning it makes rapid +strides so you may see your training + + align:start position:0% +strides so you may see your training + + + align:start position:0% +strides so you may see your training +loss decrease whoops super fast and then + + align:start position:0% +loss decrease whoops super fast and then + + + align:start position:0% +loss decrease whoops super fast and then +kind of you know peter out and it's this + + align:start position:0% +kind of you know peter out and it's this + + + align:start position:0% +kind of you know peter out and it's this +particular behavior which got people + + align:start position:0% +particular behavior which got people + + + align:start position:0% +particular behavior which got people +super excited that hey in machine + + align:start position:0% +super excited that hey in machine + + + align:start position:0% +super excited that hey in machine +learning we are working with all sorts + + align:start position:0% +learning we are working with all sorts + + + align:start position:0% +learning we are working with all sorts +of big data I just want a quick and + + align:start position:0% +of big data I just want a quick and + + + align:start position:0% +of big data I just want a quick and +dirty progress on my training training I + + align:start position:0% +dirty progress on my training training I + + + align:start position:0% +dirty progress on my training training I +don't care about getting to the best + + align:start position:0% +don't care about getting to the best + + + align:start position:0% +don't care about getting to the best +optimum because in machine learning you + + align:start position:0% +optimum because in machine learning you + + + align:start position:0% +optimum because in machine learning you +don't just care about solving the + + align:start position:0% +don't just care about solving the + + + align:start position:0% +don't just care about solving the +optimization problem you actually care + + align:start position:0% +optimization problem you actually care + + + align:start position:0% +optimization problem you actually care +about finding solutions that work well + + align:start position:0% +about finding solutions that work well + + + align:start position:0% +about finding solutions that work well +on unseen data so that means you don't + + align:start position:0% +on unseen data so that means you don't + + + align:start position:0% +on unseen data so that means you don't +want to over fit and solve the + + align:start position:0% +want to over fit and solve the + + + align:start position:0% +want to over fit and solve the +optimization problem supremely well so + + align:start position:0% +optimization problem supremely well so + + + align:start position:0% +optimization problem supremely well so +it's great to make rapid initial + + align:start position:0% +it's great to make rapid initial + + + align:start position:0% +it's great to make rapid initial +progress and if after that progress + + align:start position:0% +progress and if after that progress + + + align:start position:0% +progress and if after that progress +Peters out it's okay + + align:start position:0% +Peters out it's okay + + + align:start position:0% +Peters out it's okay +this intuitionistic statements that are + + align:start position:0% +this intuitionistic statements that are + + + align:start position:0% +this intuitionistic statements that are +making in some nice cases like convex + + align:start position:0% +making in some nice cases like convex + + + align:start position:0% +making in some nice cases like convex +optimization problems one can + + align:start position:0% +optimization problems one can + + + align:start position:0% +optimization problems one can +mathematically fully quantify this one + + align:start position:0% +mathematically fully quantify this one + + + align:start position:0% +mathematically fully quantify this one +can prove theorems to quantify its thing + + align:start position:0% +can prove theorems to quantify its thing + + + align:start position:0% +can prove theorems to quantify its thing +that I said in terms of how close how + + align:start position:0% +that I said in terms of how close how + + + align:start position:0% +that I said in terms of how close how +fast and so on we'll see a little bit of + + align:start position:0% +fast and so on we'll see a little bit of + + + align:start position:0% +fast and so on we'll see a little bit of +that and this is what really happens to + + align:start position:0% +that and this is what really happens to + + + align:start position:0% +that and this is what really happens to +SGD you know it makes great initial + + align:start position:0% +SGD you know it makes great initial + + + align:start position:0% +SGD you know it makes great initial +progress and regardless of how you use + + align:start position:0% +progress and regardless of how you use + + + align:start position:0% +progress and regardless of how you use +step sizes close to the optimum it can + + align:start position:0% +step sizes close to the optimum it can + + + align:start position:0% +step sizes close to the optimum it can +either get stuck or enter some kind of + + align:start position:0% +either get stuck or enter some kind of + + + align:start position:0% +either get stuck or enter some kind of +chaos dynamics or just behave like crazy + + align:start position:0% +chaos dynamics or just behave like crazy + + + align:start position:0% +chaos dynamics or just behave like crazy +so that's typical of SGD and let's look + + align:start position:0% +so that's typical of SGD and let's look + + + align:start position:0% +so that's typical of SGD and let's look +at no slight mathematical insight into + + align:start position:0% +at no slight mathematical insight into + + + align:start position:0% +at no slight mathematical insight into +roughly why this behavior may happen + + align:start position:0% +roughly why this behavior may happen + + + align:start position:0% +roughly why this behavior may happen +this is a trivial 1 dimensional + + align:start position:0% +this is a trivial 1 dimensional + + + align:start position:0% +this is a trivial 1 dimensional +optimization problem but it conveys the + + align:start position:0% +optimization problem but it conveys the + + + align:start position:0% +optimization problem but it conveys the +crux of why this behavior is displayed + + align:start position:0% +crux of why this behavior is displayed + + + align:start position:0% +crux of why this behavior is displayed +by stochastic gradient methods that it + + align:start position:0% +by stochastic gradient methods that it + + + align:start position:0% +by stochastic gradient methods that it +works really well in the beginning + + align:start position:0% +works really well in the beginning + + + align:start position:0% +works really well in the beginning +then it can God knows what happens when + + align:start position:0% +then it can God knows what happens when + + + align:start position:0% +then it can God knows what happens when +it comes close to the optimum anything + + align:start position:0% +it comes close to the optimum anything + + + align:start position:0% +it comes close to the optimum anything +can happen so let's look at that okay so + + align:start position:0% +can happen so let's look at that okay so + + + align:start position:0% +can happen so let's look at that okay so +let's look at a simple one dimensional + + align:start position:0% +let's look at a simple one dimensional + + + align:start position:0% +let's look at a simple one dimensional +optimization problem I'll kind of draw + + align:start position:0% +optimization problem I'll kind of draw + + + align:start position:0% +optimization problem I'll kind of draw +it out maybe on the other side so that + + align:start position:0% +it out maybe on the other side so that + + + align:start position:0% +it out maybe on the other side so that +people on this side are not + + align:start position:0% +people on this side are not + + + align:start position:0% +people on this side are not +disadvantaged so I'll just draw out a + + align:start position:0% +disadvantaged so I'll just draw out a + + + align:start position:0% +disadvantaged so I'll just draw out a +least squares problem X is one + + align:start position:0% +least squares problem X is one + + + align:start position:0% +least squares problem X is one +dimensional previously I had AI + + align:start position:0% +dimensional previously I had AI + + + align:start position:0% +dimensional previously I had AI +transpose X now AI is also a scalar so + + align:start position:0% +transpose X now AI is also a scalar so + + + align:start position:0% +transpose X now AI is also a scalar so +it's just 1d stuff everything is 1d so + + align:start position:0% +it's just 1d stuff everything is 1d so + + + align:start position:0% +it's just 1d stuff everything is 1d so +this is our set up think of AI into X + + align:start position:0% +this is our set up think of AI into X + + + align:start position:0% +this is our set up think of AI into X +minus bi these are quadratic functions + + align:start position:0% +minus bi these are quadratic functions + + + align:start position:0% +minus bi these are quadratic functions +right so they look like this + + align:start position:0% +right so they look like this + + + align:start position:0% +right so they look like this +corresponding to different eyes there's + + align:start position:0% +corresponding to different eyes there's + + + align:start position:0% +corresponding to different eyes there's +like some different functions sitting + + align:start position:0% +like some different functions sitting + + + align:start position:0% +like some different functions sitting +and so on so these are my n different + + align:start position:0% +and so on so these are my n different + + + align:start position:0% +and so on so these are my n different +loss functions and I want to minimize + + align:start position:0% +loss functions and I want to minimize + + + align:start position:0% +loss functions and I want to minimize +those we know we can actually explicitly + + align:start position:0% +those we know we can actually explicitly + + + align:start position:0% +those we know we can actually explicitly +compute the solution of that problem + + align:start position:0% +compute the solution of that problem + + + align:start position:0% +compute the solution of that problem +right you set so you set the derivative + + align:start position:0% +right you set so you set the derivative + + + align:start position:0% +right you set so you set the derivative +of f of X to 0 so you set the gradient + + align:start position:0% +of f of X to 0 so you set the gradient + + + align:start position:0% +of f of X to 0 so you set the gradient +of f of X to 0 hopefully that's easy for + + align:start position:0% +of f of X to 0 hopefully that's easy for + + + align:start position:0% +of f of X to 0 hopefully that's easy for +you to do so if you do that + + align:start position:0% +you to do so if you do that + + + align:start position:0% +you to do so if you do that +differentiation will get gradient of f + + align:start position:0% +differentiation will get gradient of f + + + align:start position:0% +differentiation will get gradient of f +of X will be just given by well you can + + align:start position:0% +of X will be just given by well you can + + + align:start position:0% +of X will be just given by well you can +do that in your head I'll just write it + + align:start position:0% +do that in your head I'll just write it + + + align:start position:0% +do that in your head I'll just write it +out explicitly AI X minus bi times AI is + + align:start position:0% +out explicitly AI X minus bi times AI is + + + align:start position:0% +out explicitly AI X minus bi times AI is +equal to 0 and you solve that for X you + + align:start position:0% +equal to 0 and you solve that for X you + + + align:start position:0% +equal to 0 and you solve that for X you +get X star the optimum of this least + + align:start position:0% +get X star the optimum of this least + + + align:start position:0% +get X star the optimum of this least +squares problem right so we actually + + align:start position:0% +squares problem right so we actually + + + align:start position:0% +squares problem right so we actually +know how to solve it pretty easily it's + + align:start position:0% +know how to solve it pretty easily it's + + + align:start position:0% +know how to solve it pretty easily it's +a really cool example actually I got + + align:start position:0% +a really cool example actually I got + + + align:start position:0% +a really cool example actually I got +that from textbook by Professor Dimitri + + align:start position:0% +that from textbook by Professor Dimitri + + + align:start position:0% +that from textbook by Professor Dimitri +butts acres now a very interesting thing + + align:start position:0% +butts acres now a very interesting thing + + + align:start position:0% +butts acres now a very interesting thing +we are not going to use the full + + align:start position:0% +we are not going to use the full + + + align:start position:0% +we are not going to use the full +gradient we are only you going to use + + align:start position:0% +gradient we are only you going to use + + + align:start position:0% +gradient we are only you going to use +the gradients of individual components + + align:start position:0% +the gradients of individual components + + + align:start position:0% +the gradients of individual components +right so what does the minimum of an + + align:start position:0% +right so what does the minimum of an + + + align:start position:0% +right so what does the minimum of an +individual component look like well the + + align:start position:0% +individual component look like well the + + + align:start position:0% +individual component look like well the +minimum of an individual component is + + align:start position:0% +minimum of an individual component is + + + align:start position:0% +minimum of an individual component is +attained when we can set this thing to + + align:start position:0% +attained when we can set this thing to + + + align:start position:0% +attained when we can set this thing to +zero and that thing becomes zero if you + + align:start position:0% +zero and that thing becomes zero if you + + + align:start position:0% +zero and that thing becomes zero if you +just pick X equal to B I divided by AI + + align:start position:0% +just pick X equal to B I divided by AI + + + align:start position:0% +just pick X equal to B I divided by AI +right so a single component we can be + + align:start position:0% +right so a single component we can be + + + align:start position:0% +right so a single component we can be +minimized by that choice so you can do a + + align:start position:0% +minimized by that choice so you can do a + + + align:start position:0% +minimized by that choice so you can do a +little bit of arithmetic mean geometric + + align:start position:0% +little bit of arithmetic mean geometric + + + align:start position:0% +little bit of arithmetic mean geometric +mean type inequalities to draw this + + align:start position:0% +mean type inequalities to draw this + + + align:start position:0% +mean type inequalities to draw this +picture + + align:start position:0% + + + + align:start position:0% + +so overall I from 1 through n this is + + align:start position:0% +so overall I from 1 through n this is + + + align:start position:0% +so overall I from 1 through n this is +the minimum value of this ratio AI bi bi + + align:start position:0% +the minimum value of this ratio AI bi bi + + + align:start position:0% +the minimum value of this ratio AI bi bi +and let's say this is the max value of + + align:start position:0% +and let's say this is the max value of + + + align:start position:0% +and let's say this is the max value of +AI bi bi and we know that closed-form + + align:start position:0% +AI bi bi and we know that closed-form + + + align:start position:0% +AI bi bi and we know that closed-form +solution that is the true solution so + + align:start position:0% +solution that is the true solution so + + + align:start position:0% +solution that is the true solution so +you can verify with some algebra that + + align:start position:0% +you can verify with some algebra that + + + align:start position:0% +you can verify with some algebra that +that solution will lie in this interval + + align:start position:0% +that solution will lie in this interval + + + align:start position:0% +that solution will lie in this interval +so let's so you you may want to this is + + align:start position:0% +so let's so you you may want to this is + + + align:start position:0% +so let's so you you may want to this is +a tiny exercise for you hopefully some + + align:start position:0% +a tiny exercise for you hopefully some + + + align:start position:0% +a tiny exercise for you hopefully some +of you love inequalities like me so this + + align:start position:0% +of you love inequalities like me so this + + + align:start position:0% +of you love inequalities like me so this +is hopefully not such a bad exercise but + + align:start position:0% +is hopefully not such a bad exercise but + + + align:start position:0% +is hopefully not such a bad exercise but +you can verify that within this range of + + align:start position:0% +you can verify that within this range of + + + align:start position:0% +you can verify that within this range of +the individual mins and max is where the + + align:start position:0% +the individual mins and max is where the + + + align:start position:0% +the individual mins and max is where the +combined solution lies so of course + + align:start position:0% +combined solution lies so of course + + + align:start position:0% +combined solution lies so of course +intuitively you would have physics style + + align:start position:0% +intuitively you would have physics style + + + align:start position:0% +intuitively you would have physics style +thinking you would have guessed that + + align:start position:0% +thinking you would have guessed that + + + align:start position:0% +thinking you would have guessed that +right away so it means when you are + + align:start position:0% +right away so it means when you are + + + align:start position:0% +right away so it means when you are +outside where the individual solutions + + align:start position:0% +outside where the individual solutions + + + align:start position:0% +outside where the individual solutions +let's call this the far out zone and + + align:start position:0% +let's call this the far out zone and + + + align:start position:0% +let's call this the far out zone and +also this side is the far out zone and + + align:start position:0% +also this side is the far out zone and + + + align:start position:0% +also this side is the far out zone and +this region within which the true + + align:start position:0% +this region within which the true + + + align:start position:0% +this region within which the true +minimum can lie you can say okay that's + + align:start position:0% +minimum can lie you can say okay that's + + + align:start position:0% +minimum can lie you can say okay that's +the region of confusion why I'm calling + + align:start position:0% +the region of confusion why I'm calling + + + align:start position:0% +the region of confusion why I'm calling +it the region of confusion because there + + align:start position:0% +it the region of confusion because there + + + align:start position:0% +it the region of confusion because there +by minimizing an individual fi you're + + align:start position:0% +by minimizing an individual fi you're + + + align:start position:0% +by minimizing an individual fi you're +not going to be able to tell what is the + + align:start position:0% +not going to be able to tell what is the + + + align:start position:0% +not going to be able to tell what is the +combined X star that's all and a very + + align:start position:0% +combined X star that's all and a very + + + align:start position:0% +combined X star that's all and a very +interesting thing happens now just to + + align:start position:0% +interesting thing happens now just to + + + align:start position:0% +interesting thing happens now just to +gain some mathematical insight into that + + align:start position:0% +gain some mathematical insight into that + + + align:start position:0% +gain some mathematical insight into that +simulation that I showed you that if you + + align:start position:0% +simulation that I showed you that if you + + + align:start position:0% +simulation that I showed you that if you +have a scalar X that is outside this + + align:start position:0% +have a scalar X that is outside this + + + align:start position:0% +have a scalar X that is outside this +region of confusion which states that if + + align:start position:0% +region of confusion which states that if + + + align:start position:0% +region of confusion which states that if +you are far from the region within which + + align:start position:0% +you are far from the region within which + + + align:start position:0% +you are far from the region within which +an optimum can lie so you're far away + + align:start position:0% +an optimum can lie so you're far away + + + align:start position:0% +an optimum can lie so you're far away +you've just started out your progress + + align:start position:0% +you've just started out your progress + + + align:start position:0% +you've just started out your progress +you made a random initialization most + + align:start position:0% +you made a random initialization most + + + align:start position:0% +you made a random initialization most +likely a far away from where the + + align:start position:0% +likely a far away from where the + + + align:start position:0% +likely a far away from where the +solution is so suppose that's where you + + align:start position:0% +solution is so suppose that's where you + + + align:start position:0% +solution is so suppose that's where you +are what happens when you're in that far + + align:start position:0% +are what happens when you're in that far + + + align:start position:0% +are what happens when you're in that far +out region so if you're in that far out + + align:start position:0% +out region so if you're in that far out + + + align:start position:0% +out region so if you're in that far out +region + + align:start position:0% +region + + + align:start position:0% +region +you use a stochastic gradient of some + + align:start position:0% +you use a stochastic gradient of some + + + align:start position:0% +you use a stochastic gradient of some +eyuth component so the full gradient + + align:start position:0% +eyuth component so the full gradient + + + align:start position:0% +eyuth component so the full gradient +will look like that a stochastic + + align:start position:0% +will look like that a stochastic + + + align:start position:0% +will look like that a stochastic +gradient looks like this one component + + align:start position:0% +gradient looks like this one component + + + align:start position:0% +gradient looks like this one component +and when you are far out outside that + + align:start position:0% +and when you are far out outside that + + + align:start position:0% +and when you are far out outside that +min and Max regime then you can check by + + align:start position:0% +min and Max regime then you can check by + + + align:start position:0% +min and Max regime then you can check by +just by just looking at it that a + + align:start position:0% +just by just looking at it that a + + + align:start position:0% +just by just looking at it that a +stochastic gradient in the far away + + align:start position:0% +stochastic gradient in the far away + + + align:start position:0% +stochastic gradient in the far away +regime has exactly the same sign as the + + align:start position:0% +regime has exactly the same sign as the + + + align:start position:0% +regime has exactly the same sign as the +full gradient + + align:start position:0% +full gradient + + + align:start position:0% +full gradient +what does gradient descent do it says + + align:start position:0% +what does gradient descent do it says + + + align:start position:0% +what does gradient descent do it says +well walk in the direction of the + + align:start position:0% +well walk in the direction of the + + + align:start position:0% +well walk in the direction of the +negative gradient and if far away from + + align:start position:0% +negative gradient and if far away from + + + align:start position:0% +negative gradient and if far away from +the optimum outside the region of + + align:start position:0% +the optimum outside the region of + + + align:start position:0% +the optimum outside the region of +confusion your stochastic gradient has + + align:start position:0% +confusion your stochastic gradient has + + + align:start position:0% +confusion your stochastic gradient has +the same sign as the true gradient may + + align:start position:0% +the same sign as the true gradient may + + + align:start position:0% +the same sign as the true gradient may +be in more linear algebra terms it makes + + align:start position:0% +be in more linear algebra terms it makes + + + align:start position:0% +be in more linear algebra terms it makes +you know it makes an acute angle with + + align:start position:0% +you know it makes an acute angle with + + + align:start position:0% +you know it makes an acute angle with +your gradient that means if even though + + align:start position:0% +your gradient that means if even though + + + align:start position:0% +your gradient that means if even though +a stochastic gradient is not exactly the + + align:start position:0% +a stochastic gradient is not exactly the + + + align:start position:0% +a stochastic gradient is not exactly the +full gradient it has some component in + + align:start position:0% +full gradient it has some component in + + + align:start position:0% +full gradient it has some component in +the direction of the true gradient this + + align:start position:0% +the direction of the true gradient this + + + align:start position:0% +the direction of the true gradient this +is 1d here it is exactly the same sign + + align:start position:0% +is 1d here it is exactly the same sign + + + align:start position:0% +is 1d here it is exactly the same sign +in multiple dimensions this is the idea + + align:start position:0% +in multiple dimensions this is the idea + + + align:start position:0% +in multiple dimensions this is the idea +that it will have some component in the + + align:start position:0% +that it will have some component in the + + + align:start position:0% +that it will have some component in the +direction of the true gradient when + + align:start position:0% +direction of the true gradient when + + + align:start position:0% +direction of the true gradient when +you're far away which means if you then + + align:start position:0% +you're far away which means if you then + + + align:start position:0% +you're far away which means if you then +use that direction to make an update in + + align:start position:0% +use that direction to make an update in + + + align:start position:0% +use that direction to make an update in +that style you will end up making solid + + align:start position:0% +that style you will end up making solid + + + align:start position:0% +that style you will end up making solid +progress and the beauty is in the time + + align:start position:0% +progress and the beauty is in the time + + + align:start position:0% +progress and the beauty is in the time +it would have taken you to do one single + + align:start position:0% +it would have taken you to do one single + + + align:start position:0% +it would have taken you to do one single +iteration of batch gradient descent far + + align:start position:0% +iteration of batch gradient descent far + + + align:start position:0% +iteration of batch gradient descent far +away you can do million stochastic steps + + align:start position:0% +away you can do million stochastic steps + + + align:start position:0% +away you can do million stochastic steps +and each step will make some progress + + align:start position:0% +and each step will make some progress + + + align:start position:0% +and each step will make some progress +and that's why you we see this dramatic + + align:start position:0% +and that's why you we see this dramatic + + + align:start position:0% +and that's why you we see this dramatic +initial again this is in the 1d case + + align:start position:0% +initial again this is in the 1d case + + + align:start position:0% +initial again this is in the 1d case +this is explicit mathematically in the + + align:start position:0% +this is explicit mathematically in the + + + align:start position:0% +this is explicit mathematically in the +high D case this is more intuitive ok + + align:start position:0% +high D case this is more intuitive ok + + + align:start position:0% +high D case this is more intuitive ok +without further assumptions about angles + + align:start position:0% +without further assumptions about angles + + + align:start position:0% +without further assumptions about angles +etc one can't make such a broad claim + + align:start position:0% +etc one can't make such a broad claim + + + align:start position:0% +etc one can't make such a broad claim +but intuitively this is what's happening + + align:start position:0% +but intuitively this is what's happening + + + align:start position:0% +but intuitively this is what's happening +on why you see this awesome initial + + align:start position:0% +on why you see this awesome initial + + + align:start position:0% +on why you see this awesome initial +speed + + align:start position:0% + + + + align:start position:0% + +and once you inside the region of + + align:start position:0% +and once you inside the region of + + + align:start position:0% +and once you inside the region of +confusion then this behavior breaks down + + align:start position:0% +confusion then this behavior breaks down + + + align:start position:0% +confusion then this behavior breaks down +some stochastic gradient we have the + + align:start position:0% +some stochastic gradient we have the + + + align:start position:0% +some stochastic gradient we have the +same sign as the full gradient some may + + align:start position:0% +same sign as the full gradient some may + + + align:start position:0% +same sign as the full gradient some may +not and that's why you can get at crazy + + align:start position:0% +not and that's why you can get at crazy + + + align:start position:0% +not and that's why you can get at crazy +fluctuations so this simple 1d example + + align:start position:0% +fluctuations so this simple 1d example + + + align:start position:0% +fluctuations so this simple 1d example +kind of exactly shows you what we saw in + + align:start position:0% +kind of exactly shows you what we saw in + + + align:start position:0% +kind of exactly shows you what we saw in +that picture and people really loved + + align:start position:0% +that picture and people really loved + + + align:start position:0% +that picture and people really loved +this initial progress because often we + + align:start position:0% +this initial progress because often we + + + align:start position:0% +this initial progress because often we +also do early stopping you know train + + align:start position:0% +also do early stopping you know train + + + align:start position:0% +also do early stopping you know train +for some time and then you say ok I'm + + align:start position:0% +for some time and then you say ok I'm + + + align:start position:0% +for some time and then you say ok I'm +done so importantly if you are purely an + + align:start position:0% +done so importantly if you are purely an + + + align:start position:0% +done so importantly if you are purely an +optimization person not thinking so much + + align:start position:0% +optimization person not thinking so much + + + align:start position:0% +optimization person not thinking so much +in terms of machine learning when please + + align:start position:0% +in terms of machine learning when please + + + align:start position:0% +in terms of machine learning when please +keep in mind that stochastic gradient + + align:start position:0% +keep in mind that stochastic gradient + + + align:start position:0% +keep in mind that stochastic gradient +descent or stochastic gradient method is + + align:start position:0% +descent or stochastic gradient method is + + + align:start position:0% +descent or stochastic gradient method is +not such a great optimization method + + align:start position:0% +not such a great optimization method + + + align:start position:0% +not such a great optimization method +because once in the region of confusion + + align:start position:0% +because once in the region of confusion + + + align:start position:0% +because once in the region of confusion +it can just fluctuate all over forever + + align:start position:0% +it can just fluctuate all over forever + + + align:start position:0% +it can just fluctuate all over forever +and in machine learning you say oh the + + align:start position:0% +and in machine learning you say oh the + + + align:start position:0% +and in machine learning you say oh the +region of confusion that's fine it'll + + align:start position:0% +region of confusion that's fine it'll + + + align:start position:0% +region of confusion that's fine it'll +make my method robust gonna make my + + align:start position:0% +make my method robust gonna make my + + + align:start position:0% +make my method robust gonna make my +neural network training more robust will + + align:start position:0% +neural network training more robust will + + + align:start position:0% +neural network training more robust will +generalize better etcetera etcetera we + + align:start position:0% +generalize better etcetera etcetera we + + + align:start position:0% +generalize better etcetera etcetera we +like that so it depends on which frame + + align:start position:0% +like that so it depends on which frame + + + align:start position:0% +like that so it depends on which frame +of mind you are in ok so that's that's + + align:start position:0% +of mind you are in ok so that's that's + + + align:start position:0% +of mind you are in ok so that's that's +the awesome thing about the stochastic + + align:start position:0% +the awesome thing about the stochastic + + + align:start position:0% +the awesome thing about the stochastic +gradient method so I'll give you now the + + align:start position:0% +gradient method so I'll give you now the + + + align:start position:0% +gradient method so I'll give you now the +key mathematical ideas behind the + + align:start position:0% +key mathematical ideas behind the + + + align:start position:0% +key mathematical ideas behind the +success of SGD this was like little + + align:start position:0% +success of SGD this was like little + + + align:start position:0% +success of SGD this was like little +illustration very abstractly this is an + + align:start position:0% +illustration very abstractly this is an + + + align:start position:0% +illustration very abstractly this is an +idea that records throughout machine + + align:start position:0% +idea that records throughout machine + + + align:start position:0% +idea that records throughout machine +learning and throughout theoretical + + align:start position:0% +learning and throughout theoretical + + + align:start position:0% +learning and throughout theoretical +computer science and statistics any time + + align:start position:0% +computer science and statistics any time + + + align:start position:0% +computer science and statistics any time +you're faced with the need to compute an + + align:start position:0% +you're faced with the need to compute an + + + align:start position:0% +you're faced with the need to compute an +expensive quantity resort to + + align:start position:0% +expensive quantity resort to + + + align:start position:0% +expensive quantity resort to +randomization to speed up the + + align:start position:0% +randomization to speed up the + + + align:start position:0% +randomization to speed up the +computation SGD is one example the true + + align:start position:0% +computation SGD is one example the true + + + align:start position:0% +computation SGD is one example the true +gradient was expensive to compute so we + + align:start position:0% +gradient was expensive to compute so we + + + align:start position:0% +gradient was expensive to compute so we +create a randomized estimate of the true + + align:start position:0% +create a randomized estimate of the true + + + align:start position:0% +create a randomized estimate of the true +gradient and the randomized estimate is + + align:start position:0% +gradient and the randomized estimate is + + + align:start position:0% +gradient and the randomized estimate is +much faster to compute and + + align:start position:0% +much faster to compute and + + + align:start position:0% +much faster to compute and +mathematically what will start happening + + align:start position:0% +mathematically what will start happening + + + align:start position:0% +mathematically what will start happening +is + + align:start position:0% +is + + + align:start position:0% +is +depending on how good your randomized + + align:start position:0% +depending on how good your randomized + + + align:start position:0% +depending on how good your randomized +estimate is your method may or may not + + align:start position:0% +estimate is your method may or may not + + + align:start position:0% +estimate is your method may or may not +converge to the right answer so you of + + align:start position:0% +converge to the right answer so you of + + + align:start position:0% +converge to the right answer so you of +course one has to be careful about what + + align:start position:0% +course one has to be careful about what + + + align:start position:0% +course one has to be careful about what +particular randomized estimate one makes + + align:start position:0% +particular randomized estimate one makes + + + align:start position:0% +particular randomized estimate one makes +so but really abstractly even if I + + align:start position:0% +so but really abstractly even if I + + + align:start position:0% +so but really abstractly even if I +hadn't shown you the main idea this idea + + align:start position:0% +hadn't shown you the main idea this idea + + + align:start position:0% +hadn't shown you the main idea this idea +you can apply in many other settings if + + align:start position:0% +you can apply in many other settings if + + + align:start position:0% +you can apply in many other settings if +you have a difficult quantity come up + + align:start position:0% +you have a difficult quantity come up + + + align:start position:0% +you have a difficult quantity come up +with a randomized estimate and save on + + align:start position:0% +with a randomized estimate and save on + + + align:start position:0% +with a randomized estimate and save on +computation this is a very important + + align:start position:0% +computation this is a very important + + + align:start position:0% +computation this is a very important +theme throughout machine learning and + + align:start position:0% +theme throughout machine learning and + + + align:start position:0% +theme throughout machine learning and +data science okay and this is the key + + align:start position:0% +data science okay and this is the key + + + align:start position:0% +data science okay and this is the key +property so stochastic gradient descent + + align:start position:0% +property so stochastic gradient descent + + + align:start position:0% +property so stochastic gradient descent +it uses stochastic gradients stochastic + + align:start position:0% +it uses stochastic gradients stochastic + + + align:start position:0% +it uses stochastic gradients stochastic +is here just used very loosely you know + + align:start position:0% +is here just used very loosely you know + + + align:start position:0% +is here just used very loosely you know +it just means there's some randomization + + align:start position:0% +it just means there's some randomization + + + align:start position:0% +it just means there's some randomization +that's all it means + + align:start position:0% +that's all it means + + + align:start position:0% +that's all it means +and the property the key property that + + align:start position:0% +and the property the key property that + + + align:start position:0% +and the property the key property that +we have is in expectation the + + align:start position:0% +we have is in expectation the + + + align:start position:0% +we have is in expectation the +expectation is over + + align:start position:0% +expectation is over + + + align:start position:0% +expectation is over +whatever randomness you used so if you + + align:start position:0% +whatever randomness you used so if you + + + align:start position:0% +whatever randomness you used so if you +picked you know some random training + + align:start position:0% +picked you know some random training + + + align:start position:0% +picked you know some random training +data point out of the million then it is + + align:start position:0% +data point out of the million then it is + + + align:start position:0% +data point out of the million then it is +the expectation is over the probability + + align:start position:0% +the expectation is over the probability + + + align:start position:0% +the expectation is over the probability +distribution over what kind of + + align:start position:0% +distribution over what kind of + + + align:start position:0% +distribution over what kind of +randomness you used if you like picked + + align:start position:0% +randomness you used if you like picked + + + align:start position:0% +randomness you used if you like picked +uniformly at random from a million + + align:start position:0% +uniformly at random from a million + + + align:start position:0% +uniformly at random from a million +points then this expectation is over + + align:start position:0% +points then this expectation is over + + + align:start position:0% +points then this expectation is over +that uniform probability but the key + + align:start position:0% +that uniform probability but the key + + + align:start position:0% +that uniform probability but the key +property for SGD or at least the version + + align:start position:0% +property for SGD or at least the version + + + align:start position:0% +property for SGD or at least the version +of SGD i am talking about is that in + + align:start position:0% +of SGD i am talking about is that in + + + align:start position:0% +of SGD i am talking about is that in +expectation over that randomness the + + align:start position:0% +expectation over that randomness the + + + align:start position:0% +expectation over that randomness the +thing that you are pretending to use + + align:start position:0% +thing that you are pretending to use + + + align:start position:0% +thing that you are pretending to use +instead of the true gradient in + + align:start position:0% +instead of the true gradient in + + + align:start position:0% +instead of the true gradient in +expectation actually it is the true + + align:start position:0% +expectation actually it is the true + + + align:start position:0% +expectation actually it is the true +gradient so in statistics language this + + align:start position:0% +gradient so in statistics language this + + + align:start position:0% +gradient so in statistics language this +is called the stochastic gradient that + + align:start position:0% +is called the stochastic gradient that + + + align:start position:0% +is called the stochastic gradient that +we use is an unbiased estimate of the + + align:start position:0% +we use is an unbiased estimate of the + + + align:start position:0% +we use is an unbiased estimate of the +true gradient and this is a very + + align:start position:0% +true gradient and this is a very + + + align:start position:0% +true gradient and this is a very +important property in the mathematical + + align:start position:0% +important property in the mathematical + + + align:start position:0% +important property in the mathematical +analysis of stochastic gradient descent + + align:start position:0% +analysis of stochastic gradient descent + + + align:start position:0% +analysis of stochastic gradient descent +that it is an unbiased estimate and + + align:start position:0% +that it is an unbiased estimate and + + + align:start position:0% +that it is an unbiased estimate and +intuitively speaking anytime you did any + + align:start position:0% +intuitively speaking anytime you did any + + + align:start position:0% +intuitively speaking anytime you did any +proof in class or in the book or lecture + + align:start position:0% +proof in class or in the book or lecture + + + align:start position:0% +proof in class or in the book or lecture +notes wherever where you were using true + + align:start position:0% +notes wherever where you were using true + + + align:start position:0% +notes wherever where you were using true +gradients more or less you can do those + + align:start position:0% +gradients more or less you can do those + + + align:start position:0% +gradients more or less you can do those +same proofs more + + align:start position:0% +same proofs more + + + align:start position:0% +same proofs more +less not always using stochastic + + align:start position:0% +less not always using stochastic + + + align:start position:0% +less not always using stochastic +gradients by replace by encapsulating + + align:start position:0% +gradients by replace by encapsulating + + + align:start position:0% +gradients by replace by encapsulating +everything within expectations over the + + align:start position:0% +everything within expectations over the + + + align:start position:0% +everything within expectations over the +randomness I'll show you an example of + + align:start position:0% +randomness I'll show you an example of + + + align:start position:0% +randomness I'll show you an example of +what I mean by that I'm just trying to + + align:start position:0% +what I mean by that I'm just trying to + + + align:start position:0% +what I mean by that I'm just trying to +simplify that for you and in particular + + align:start position:0% + + + + align:start position:0% + +the unbiasness is great so it means I + + align:start position:0% +the unbiasness is great so it means I + + + align:start position:0% +the unbiasness is great so it means I +can kind of plug in these stochastic + + align:start position:0% +can kind of plug in these stochastic + + + align:start position:0% +can kind of plug in these stochastic +gradients in place of the true gradient + + align:start position:0% +gradients in place of the true gradient + + + align:start position:0% +gradients in place of the true gradient +and I'm still doing something meaningful + + align:start position:0% +and I'm still doing something meaningful + + + align:start position:0% +and I'm still doing something meaningful +so this is answering that earlier + + align:start position:0% +so this is answering that earlier + + + align:start position:0% +so this is answering that earlier +question you know why this random stuff + + align:start position:0% +question you know why this random stuff + + + align:start position:0% +question you know why this random stuff +why it should we think it may work but + + align:start position:0% +why it should we think it may work but + + + align:start position:0% +why it should we think it may work but +there's another very important aspect to + + align:start position:0% +there's another very important aspect to + + + align:start position:0% +there's another very important aspect to +it why it works beyond this unbiasness + + align:start position:0% +it why it works beyond this unbiasness + + + align:start position:0% +it why it works beyond this unbiasness +that the amount of noise or like the + + align:start position:0% +that the amount of noise or like the + + + align:start position:0% +that the amount of noise or like the +amount of amount of stochasticity is + + align:start position:0% +amount of amount of stochasticity is + + + align:start position:0% +amount of amount of stochasticity is +controlled so just because it is an + + align:start position:0% +controlled so just because it is an + + + align:start position:0% +controlled so just because it is an +unbiased estimate doesn't mean that it's + + align:start position:0% +unbiased estimate doesn't mean that it's + + + align:start position:0% +unbiased estimate doesn't mean that it's +going to work that well why because it + + align:start position:0% +going to work that well why because it + + + align:start position:0% +going to work that well why because it +could still fluctuate hugely right + + align:start position:0% +could still fluctuate hugely right + + + align:start position:0% +could still fluctuate hugely right +essentially plus infinity here minus + + align:start position:0% +essentially plus infinity here minus + + + align:start position:0% +essentially plus infinity here minus +infinity here you take an average you + + align:start position:0% +infinity here you take an average you + + + align:start position:0% +infinity here you take an average you +get zero so that is essentially unbiased + + align:start position:0% +get zero so that is essentially unbiased + + + align:start position:0% +get zero so that is essentially unbiased +but the fluctuation is gigantic + + align:start position:0% +but the fluctuation is gigantic + + + align:start position:0% +but the fluctuation is gigantic +so whenever talking about estimates + + align:start position:0% +so whenever talking about estimates + + + align:start position:0% +so whenever talking about estimates +what's the other key quantity we need to + + align:start position:0% +what's the other key quantity we need to + + + align:start position:0% +what's the other key quantity we need to +care about beyond expectation + + align:start position:0% +care about beyond expectation + + + align:start position:0% +care about beyond expectation +in clearance and really the key thing + + align:start position:0% +in clearance and really the key thing + + + align:start position:0% +in clearance and really the key thing +that governs the speed at which + + align:start position:0% +that governs the speed at which + + + align:start position:0% +that governs the speed at which +stochastic gradient descent does the job + + align:start position:0% +stochastic gradient descent does the job + + + align:start position:0% +stochastic gradient descent does the job +that we want it to do is how much + + align:start position:0% +that we want it to do is how much + + + align:start position:0% +that we want it to do is how much +variance do the stochastic gradient have + + align:start position:0% +variance do the stochastic gradient have + + + align:start position:0% +variance do the stochastic gradient have +just this simple statistical point in + + align:start position:0% +just this simple statistical point in + + + align:start position:0% +just this simple statistical point in +fact is at the heart of a sequence of + + align:start position:0% +fact is at the heart of a sequence of + + + align:start position:0% +fact is at the heart of a sequence of +research progress in the past five years + + align:start position:0% +research progress in the past five years + + + align:start position:0% +research progress in the past five years +in the field of stochastic gradient + + align:start position:0% +in the field of stochastic gradient + + + align:start position:0% +in the field of stochastic gradient +where people have worked really hard to + + align:start position:0% +where people have worked really hard to + + + align:start position:0% +where people have worked really hard to +come up with newer and newer fancier and + + align:start position:0% +come up with newer and newer fancier and + + + align:start position:0% +come up with newer and newer fancier and +fancier versions of stochastic gradient + + align:start position:0% +fancier versions of stochastic gradient + + + align:start position:0% +fancier versions of stochastic gradient +which have the unbiasness property but + + align:start position:0% +which have the unbiasness property but + + + align:start position:0% +which have the unbiasness property but +have smaller and smaller variants and + + align:start position:0% +have smaller and smaller variants and + + + align:start position:0% +have smaller and smaller variants and +the smaller the variance you have the + + align:start position:0% +the smaller the variance you have the + + + align:start position:0% +the smaller the variance you have the +better your stochastic gradient is as a + + align:start position:0% +better your stochastic gradient is as a + + + align:start position:0% +better your stochastic gradient is as a +replacement of the true gradient and of + + align:start position:0% +replacement of the true gradient and of + + + align:start position:0% +replacement of the true gradient and of +course the better is the replacement of + + align:start position:0% +course the better is the replacement of + + + align:start position:0% +course the better is the replacement of +the true gradient then you truly get + + align:start position:0% +the true gradient then you truly get + + + align:start position:0% +the true gradient then you truly get +that you know n time speed-up okay so + + align:start position:0% +that you know n time speed-up okay so + + + align:start position:0% +that you know n time speed-up okay so +the speed of convergence depends on how + + align:start position:0% +the speed of convergence depends on how + + + align:start position:0% +the speed of convergence depends on how +noisy the stochastic gradients are it + + align:start position:0% +noisy the stochastic gradients are it + + + align:start position:0% +noisy the stochastic gradients are it +seems like I'm going too slow I won't be + + align:start position:0% +seems like I'm going too slow I won't be + + + align:start position:0% +seems like I'm going too slow I won't be +able to do a proof i if it sucks but + + align:start position:0% +able to do a proof i if it sucks but + + + align:start position:0% +able to do a proof i if it sucks but +I'll but let's let me actually tell you + + align:start position:0% +I'll but let's let me actually tell you + + + align:start position:0% +I'll but let's let me actually tell you +then about rather than the the proof + + align:start position:0% +then about rather than the the proof + + + align:start position:0% +then about rather than the the proof +I think I'll share the proof with Gil + + align:start position:0% +I think I'll share the proof with Gil + + + align:start position:0% +I think I'll share the proof with Gil +because the proof that I want to want + + align:start position:0% +because the proof that I want to want + + + align:start position:0% +because the proof that I want to want +you to actually show you talk gives a + + align:start position:0% +you to actually show you talk gives a + + + align:start position:0% +you to actually show you talk gives a +proof of stochastic gradient is + + align:start position:0% +proof of stochastic gradient is + + + align:start position:0% +proof of stochastic gradient is +well-behaved on both convex and non + + align:start position:0% +well-behaved on both convex and non + + + align:start position:0% +well-behaved on both convex and non +convex problems and the proof I wanted + + align:start position:0% +convex problems and the proof I wanted + + + align:start position:0% +convex problems and the proof I wanted +to show was for the non convex case + + align:start position:0% +to show was for the non convex case + + + align:start position:0% +to show was for the non convex case +because it applies to neural networks so + + align:start position:0% +because it applies to neural networks so + + + align:start position:0% +because it applies to neural networks so +you may be curious about that proof and + + align:start position:0% +you may be curious about that proof and + + + align:start position:0% +you may be curious about that proof and +remarkably that proof is much simpler + + align:start position:0% +remarkably that proof is much simpler + + + align:start position:0% +remarkably that proof is much simpler +than the case of convex problems so let + + align:start position:0% +than the case of convex problems so let + + + align:start position:0% +than the case of convex problems so let +me just mention some very important + + align:start position:0% +me just mention some very important + + + align:start position:0% +me just mention some very important +points about stochastic gradient so even + + align:start position:0% +points about stochastic gradient so even + + + align:start position:0% +points about stochastic gradient so even +though this method has been around since + + align:start position:0% +though this method has been around since + + + align:start position:0% +though this method has been around since +1951 every deep learning toolkit has it + + align:start position:0% +1951 every deep learning toolkit has it + + + align:start position:0% +1951 every deep learning toolkit has it +and we are studying it in class there + + align:start position:0% +and we are studying it in class there + + + align:start position:0% +and we are studying it in class there +are still gaps between what we can say + + align:start position:0% +are still gaps between what we can say + + + align:start position:0% +are still gaps between what we can say +theoretically and what happens in + + align:start position:0% +theoretically and what happens in + + + align:start position:0% +theoretically and what happens in +practice and I'll show you those gaps + + align:start position:0% +practice and I'll show you those gaps + + + align:start position:0% +practice and I'll show you those gaps +already and encourage you to think about + + align:start position:0% +already and encourage you to think about + + + align:start position:0% +already and encourage you to think about +those if you wish + + align:start position:0% +those if you wish + + + align:start position:0% +those if you wish +so let's look back at our problem and + + align:start position:0% +so let's look back at our problem and + + + align:start position:0% +so let's look back at our problem and +tell you about two variants so here are + + align:start position:0% +tell you about two variants so here are + + + align:start position:0% +tell you about two variants so here are +the two variants I'm going to ask if any + + align:start position:0% +the two variants I'm going to ask if any + + + align:start position:0% +the two variants I'm going to ask if any +of you is familiar with this variant + + align:start position:0% +of you is familiar with this variant + + + align:start position:0% +of you is familiar with this variant +in some way or the other so let's I just + + align:start position:0% +in some way or the other so let's I just + + + align:start position:0% +in some way or the other so let's I just +call it feasible here there are no + + align:start position:0% +call it feasible here there are no + + + align:start position:0% +call it feasible here there are no +constraints so I start with any random + + align:start position:0% +constraints so I start with any random + + + align:start position:0% +constraints so I start with any random +vector of your choice in deep network + + align:start position:0% +vector of your choice in deep network + + + align:start position:0% +vector of your choice in deep network +training you have to work harder and + + align:start position:0% +training you have to work harder and + + + align:start position:0% +training you have to work harder and +then this is the iteration you run right + + align:start position:0% +then this is the iteration you run right + + + align:start position:0% +then this is the iteration you run right +option one and option two so option one + + align:start position:0% +option one and option two so option one + + + align:start position:0% +option one and option two so option one +says that was the idea we had in class + + align:start position:0% +says that was the idea we had in class + + + align:start position:0% +says that was the idea we had in class +randomly pick some training data point + + align:start position:0% +randomly pick some training data point + + + align:start position:0% +randomly pick some training data point +use it stochastic gradient well what do + + align:start position:0% +use it stochastic gradient well what do + + + align:start position:0% +use it stochastic gradient well what do +we mean by randomly pick the moment you + + align:start position:0% +we mean by randomly pick the moment you + + + align:start position:0% +we mean by randomly pick the moment you +use the word random you have to define + + align:start position:0% +use the word random you have to define + + + align:start position:0% +use the word random you have to define +what's the randomness so one randomness + + align:start position:0% +what's the randomness so one randomness + + + align:start position:0% +what's the randomness so one randomness +is uniform probability of our n training + + align:start position:0% +is uniform probability of our n training + + + align:start position:0% +is uniform probability of our n training +data points that is one randomness the + + align:start position:0% +data points that is one randomness the + + + align:start position:0% +data points that is one randomness the +other version is you pick a training + + align:start position:0% +other version is you pick a training + + + align:start position:0% +other version is you pick a training +data point without replacement so I so + + align:start position:0% +data point without replacement so I so + + + align:start position:0% +data point without replacement so I so +with replacement means you know just + + align:start position:0% +with replacement means you know just + + + align:start position:0% +with replacement means you know just +uniformly at random each time you draw a + + align:start position:0% +uniformly at random each time you draw a + + + align:start position:0% +uniformly at random each time you draw a +number from one through n use that + + align:start position:0% +number from one through n use that + + + align:start position:0% +number from one through n use that +stochastic gradient move on which means + + align:start position:0% +stochastic gradient move on which means + + + align:start position:0% +stochastic gradient move on which means +the same point can easily be picked + + align:start position:0% +the same point can easily be picked + + + align:start position:0% +the same point can easily be picked +twice also and without replacement means + + align:start position:0% +twice also and without replacement means + + + align:start position:0% +twice also and without replacement means +if you've picked a point number three + + align:start position:0% +if you've picked a point number three + + + align:start position:0% +if you've picked a point number three +you're not going to pick it again until + + align:start position:0% +you're not going to pick it again until + + + align:start position:0% +you're not going to pick it again until +you've gone through the entire training + + align:start position:0% +you've gone through the entire training + + + align:start position:0% +you've gone through the entire training +data set those are two types of + + align:start position:0% +data set those are two types of + + + align:start position:0% +data set those are two types of +randomness which version would you use + + align:start position:0% + + + + align:start position:0% + +there is no right or wrong answer to + + align:start position:0% +there is no right or wrong answer to + + + align:start position:0% +there is no right or wrong answer to +this I'm just taking a poll what would + + align:start position:0% +this I'm just taking a poll what would + + + align:start position:0% +this I'm just taking a poll what would +you use think that you're writing a + + align:start position:0% +you use think that you're writing a + + + align:start position:0% +you use think that you're writing a +program for this and maybe think really + + align:start position:0% +program for this and maybe think really + + + align:start position:0% +program for this and maybe think really +pragmatically practically so that's + + align:start position:0% +pragmatically practically so that's + + + align:start position:0% +pragmatically practically so that's +enough of an hint which version would + + align:start position:0% +enough of an hint which version would + + + align:start position:0% +enough of an hint which version would +you use I'm just curious who would use + + align:start position:0% +you use I'm just curious who would use + + + align:start position:0% +you use I'm just curious who would use +one please raise hands who and the the + + align:start position:0% +one please raise hands who and the the + + + align:start position:0% +one please raise hands who and the the +exclusion the compliment they reform I + + align:start position:0% +exclusion the compliment they reform I + + + align:start position:0% +exclusion the compliment they reform I +don't know maybe some people are + + align:start position:0% +don't know maybe some people are + + + align:start position:0% +don't know maybe some people are +undecided who would use two very few + + align:start position:0% +undecided who would use two very few + + + align:start position:0% +undecided who would use two very few +people okay how many of you use neural + + align:start position:0% +people okay how many of you use neural + + + align:start position:0% +people okay how many of you use neural +network training tool kits like + + align:start position:0% +network training tool kits like + + + align:start position:0% +network training tool kits like +tensorflow pi torch whatnot which + + align:start position:0% +tensorflow pi torch whatnot which + + + align:start position:0% +tensorflow pi torch whatnot which +version are they using + + align:start position:0% + + + + align:start position:0% + +actually every person in the real world + + align:start position:0% +actually every person in the real world + + + align:start position:0% +actually every person in the real world +is using version 2 are you really gonna + + align:start position:0% +is using version 2 are you really gonna + + + align:start position:0% +is using version 2 are you really gonna +randomly go through your RAAM each time + + align:start position:0% +randomly go through your RAAM each time + + + align:start position:0% +randomly go through your RAAM each time +to pick random points they'll kill your + + align:start position:0% +to pick random points they'll kill your + + + align:start position:0% +to pick random points they'll kill your +GPU performance like anything what + + align:start position:0% +GPU performance like anything what + + + align:start position:0% +GPU performance like anything what +people do is take a data set use a pre + + align:start position:0% +people do is take a data set use a pre + + + align:start position:0% +people do is take a data set use a pre +shuffle operation and then just Boop + + align:start position:0% +shuffle operation and then just Boop + + + align:start position:0% +shuffle operation and then just Boop +stream through the data what the + + align:start position:0% +stream through the data what the + + + align:start position:0% +stream through the data what the +streaming through the data mean without + + align:start position:0% +streaming through the data mean without + + + align:start position:0% +streaming through the data mean without +replacement so all the toolkits actually + + align:start position:0% +replacement so all the toolkits actually + + + align:start position:0% +replacement so all the toolkits actually +are using the without replacement + + align:start position:0% +are using the without replacement + + + align:start position:0% +are using the without replacement +version even though intuitively the rent + + align:start position:0% +version even though intuitively the rent + + + align:start position:0% +version even though intuitively the rent +just uniform random feels much nicer and + + align:start position:0% +just uniform random feels much nicer and + + + align:start position:0% +just uniform random feels much nicer and +that feeling is not ill-founded because + + align:start position:0% +that feeling is not ill-founded because + + + align:start position:0% +that feeling is not ill-founded because +that's the only version we know how to + + align:start position:0% +that's the only version we know how to + + + align:start position:0% +that's the only version we know how to +analyze mathematically so even for this + + align:start position:0% +analyze mathematically so even for this + + + align:start position:0% +analyze mathematically so even for this +method everybody studies it their + + align:start position:0% +method everybody studies it their + + + align:start position:0% +method everybody studies it their +million papers on it the version that is + + align:start position:0% +million papers on it the version that is + + + align:start position:0% +million papers on it the version that is +used in practice is not the version we + + align:start position:0% +used in practice is not the version we + + + align:start position:0% +used in practice is not the version we +know how to analyze it's a major open + + align:start position:0% +know how to analyze it's a major open + + + align:start position:0% +know how to analyze it's a major open +problem in the field of stochastic + + align:start position:0% +problem in the field of stochastic + + + align:start position:0% +problem in the field of stochastic +gradient to actually analyze the version + + align:start position:0% +gradient to actually analyze the version + + + align:start position:0% +gradient to actually analyze the version +that we use in practice it's kind of + + align:start position:0% +that we use in practice it's kind of + + + align:start position:0% +that we use in practice it's kind of +embarrassing but it's without + + align:start position:0% +embarrassing but it's without + + + align:start position:0% +embarrassing but it's without +replacement means non iid probability + + align:start position:0% +replacement means non iid probability + + + align:start position:0% +replacement means non iid probability +theory and non iid probability theory is + + align:start position:0% +theory and non iid probability theory is + + + align:start position:0% +theory and non iid probability theory is +not so easy + + align:start position:0% +not so easy + + + align:start position:0% +not so easy +that's the answer okay so the other + + align:start position:0% +that's the answer okay so the other + + + align:start position:0% +that's the answer okay so the other +version is this mini batch idea which + + align:start position:0% +version is this mini batch idea which + + + align:start position:0% +version is this mini batch idea which +you mentioned really early on is that + + align:start position:0% +you mentioned really early on is that + + + align:start position:0% +you mentioned really early on is that +rather than pick one random point I'll + + align:start position:0% +rather than pick one random point I'll + + + align:start position:0% +rather than pick one random point I'll +pick a mini batch so I had a million + + align:start position:0% +pick a mini batch so I had a million + + + align:start position:0% +pick a mini batch so I had a million +points each time instead of picking one + + align:start position:0% +points each time instead of picking one + + + align:start position:0% +points each time instead of picking one +maybe I'll pick 10 or 100 or thousand or + + align:start position:0% +maybe I'll pick 10 or 100 or thousand or + + + align:start position:0% +maybe I'll pick 10 or 100 or thousand or +what have you + + align:start position:0% +what have you + + + align:start position:0% +what have you +so this averages things averaging things + + align:start position:0% +so this averages things averaging things + + + align:start position:0% +so this averages things averaging things +reduces the variance so this is actually + + align:start position:0% +reduces the variance so this is actually + + + align:start position:0% +reduces the variance so this is actually +a good thing because the more quantities + + align:start position:0% +a good thing because the more quantities + + + align:start position:0% +a good thing because the more quantities +you averaged the less noise you have + + align:start position:0% +you averaged the less noise you have + + + align:start position:0% +you averaged the less noise you have +that's kind of what happens in + + align:start position:0% +that's kind of what happens in + + + align:start position:0% +that's kind of what happens in +probability right so we pick a mini + + align:start position:0% +probability right so we pick a mini + + + align:start position:0% +probability right so we pick a mini +batch and the stochastic estimate now is + + align:start position:0% +batch and the stochastic estimate now is + + + align:start position:0% +batch and the stochastic estimate now is +this you know not just a single gradient + + align:start position:0% +this you know not just a single gradient + + + align:start position:0% +this you know not just a single gradient +but averaged over a mini batch so mini + + align:start position:0% +but averaged over a mini batch so mini + + + align:start position:0% +but averaged over a mini batch so mini +batch of size one is the pure vanilla + + align:start position:0% +batch of size one is the pure vanilla + + + align:start position:0% +batch of size one is the pure vanilla +SGD mini batch of size n is nothing + + align:start position:0% +SGD mini batch of size n is nothing + + + align:start position:0% +SGD mini batch of size n is nothing +other than pure gradient descent + + align:start position:0% +other than pure gradient descent + + + align:start position:0% +other than pure gradient descent +something in between is what people + + align:start position:0% +something in between is what people + + + align:start position:0% +something in between is what people +actually use + + align:start position:0% +actually use + + + align:start position:0% +actually use +and again the theoretical analysis only + + align:start position:0% +and again the theoretical analysis only + + + align:start position:0% +and again the theoretical analysis only +exists if the mini-batch is picked with + + align:start position:0% +exists if the mini-batch is picked with + + + align:start position:0% +exists if the mini-batch is picked with +replacement not without replacement so + + align:start position:0% +replacement not without replacement so + + + align:start position:0% +replacement not without replacement so +one of the reasons actually a very + + align:start position:0% +one of the reasons actually a very + + + align:start position:0% +one of the reasons actually a very +important thing in theory you don't gain + + align:start position:0% +important thing in theory you don't gain + + + align:start position:0% +important thing in theory you don't gain +too much in terms of computational gains + + align:start position:0% +too much in terms of computational gains + + + align:start position:0% +too much in terms of computational gains +on convergence speed by using mini + + align:start position:0% +on convergence speed by using mini + + + align:start position:0% +on convergence speed by using mini +matches but mini batches are really + + align:start position:0% +matches but mini batches are really + + + align:start position:0% +matches but mini batches are really +crucial especially in you know deep + + align:start position:0% +crucial especially in you know deep + + + align:start position:0% +crucial especially in you know deep +learning GPU style training because they + + align:start position:0% +learning GPU style training because they + + + align:start position:0% +learning GPU style training because they +allow you to do things in parallel each + + align:start position:0% +allow you to do things in parallel each + + + align:start position:0% +allow you to do things in parallel each +thread or each core or sub core or small + + align:start position:0% +thread or each core or sub core or small + + + align:start position:0% +thread or each core or sub core or small +chip or what-have-you depending on your + + align:start position:0% +chip or what-have-you depending on your + + + align:start position:0% +chip or what-have-you depending on your +hardware can be working with one + + align:start position:0% +hardware can be working with one + + + align:start position:0% +hardware can be working with one +stochastic gradient so mini batch is the + + align:start position:0% +stochastic gradient so mini batch is the + + + align:start position:0% +stochastic gradient so mini batch is the +larger the mini batch the more things + + align:start position:0% +larger the mini batch the more things + + + align:start position:0% +larger the mini batch the more things +you can do in parallel so mini batches + + align:start position:0% +you can do in parallel so mini batches + + + align:start position:0% +you can do in parallel so mini batches +are greatly exploited by people to give + + align:start position:0% +are greatly exploited by people to give + + + align:start position:0% +are greatly exploited by people to give +you a cheap version of parallelism and + + align:start position:0% +you a cheap version of parallelism and + + + align:start position:0% +you a cheap version of parallelism and +where does the parallelism happen you + + align:start position:0% +where does the parallelism happen you + + + align:start position:0% +where does the parallelism happen you +can think that each core computes a + + align:start position:0% +can think that each core computes a + + + align:start position:0% +can think that each core computes a +stochastic gradient so the hard part is + + align:start position:0% +stochastic gradient so the hard part is + + + align:start position:0% +stochastic gradient so the hard part is +not adding these things up and making + + align:start position:0% +not adding these things up and making + + + align:start position:0% +not adding these things up and making +the update to X the hard part is + + align:start position:0% +the update to X the hard part is + + + align:start position:0% +the update to X the hard part is +computing a stochastic gradient so if + + align:start position:0% +computing a stochastic gradient so if + + + align:start position:0% +computing a stochastic gradient so if +you can compute 10,000 of those in + + align:start position:0% +you can compute 10,000 of those in + + + align:start position:0% +you can compute 10,000 of those in +parallel because you have 10,000 cores + + align:start position:0% +parallel because you have 10,000 cores + + + align:start position:0% +parallel because you have 10,000 cores +great for you and that's the reason + + align:start position:0% +great for you and that's the reason + + + align:start position:0% +great for you and that's the reason +people love using mini batches but a + + align:start position:0% +people love using mini batches but a + + + align:start position:0% +people love using mini batches but a +nice side remark here this is also this + + align:start position:0% +nice side remark here this is also this + + + align:start position:0% +nice side remark here this is also this +brings us close to the research edge of + + align:start position:0% +brings us close to the research edge of + + + align:start position:0% +brings us close to the research edge of +things again that well you'd love to use + + align:start position:0% +things again that well you'd love to use + + + align:start position:0% +things again that well you'd love to use +very large mini batches so that you can + + align:start position:0% +very large mini batches so that you can + + + align:start position:0% +very large mini batches so that you can +fully max out on the parallelism + + align:start position:0% +fully max out on the parallelism + + + align:start position:0% +fully max out on the parallelism +available to you right maybe you have a + + align:start position:0% +available to you right maybe you have a + + + align:start position:0% +available to you right maybe you have a +multi GPU system if you're friends with + + align:start position:0% +multi GPU system if you're friends with + + + align:start position:0% +multi GPU system if you're friends with +NVDA or Google I only have like two GPUs + + align:start position:0% +NVDA or Google I only have like two GPUs + + + align:start position:0% +NVDA or Google I only have like two GPUs +but it depends on how many GPUs you have + + align:start position:0% +but it depends on how many GPUs you have + + + align:start position:0% +but it depends on how many GPUs you have +you'd like to really max out on + + align:start position:0% +you'd like to really max out on + + + align:start position:0% +you'd like to really max out on +parallelism so that you can really + + align:start position:0% +parallelism so that you can really + + + align:start position:0% +parallelism so that you can really +crunch through big datasets as fast as + + align:start position:0% +crunch through big datasets as fast as + + + align:start position:0% +crunch through big datasets as fast as +possible but you know what happens with + + align:start position:0% +possible but you know what happens with + + + align:start position:0% +possible but you know what happens with +very large mini batches so if you have + + align:start position:0% +very large mini batches so if you have + + + align:start position:0% +very large mini batches so if you have +very large mini batches stochastic + + align:start position:0% +very large mini batches stochastic + + + align:start position:0% +very large mini batches stochastic +gradient starts looking more like full + + align:start position:0% +gradient starts looking more like full + + + align:start position:0% +gradient starts looking more like full +gradient descent which is also called + + align:start position:0% +gradient descent which is also called + + + align:start position:0% +gradient descent which is also called +batch gradient descent that's not a bad + + align:start position:0% +batch gradient descent that's not a bad + + + align:start position:0% +batch gradient descent that's not a bad +thing that's awesome for optimization + + align:start position:0% +thing that's awesome for optimization + + + align:start position:0% +thing that's awesome for optimization +but it is a weird conundrum that happens + + align:start position:0% +but it is a weird conundrum that happens + + + align:start position:0% +but it is a weird conundrum that happens +in training deep neural networks this + + align:start position:0% +in training deep neural networks this + + + align:start position:0% +in training deep neural networks this +type of problem we wouldn't have for + + align:start position:0% +type of problem we wouldn't have for + + + align:start position:0% +type of problem we wouldn't have for +convex optimization but in deep neural + + align:start position:0% +convex optimization but in deep neural + + + align:start position:0% +convex optimization but in deep neural +networks this is really disturbing thing + + align:start position:0% +networks this is really disturbing thing + + + align:start position:0% +networks this is really disturbing thing +happens that if you use this very large + + align:start position:0% +happens that if you use this very large + + + align:start position:0% +happens that if you use this very large +mini-batches your method starts + + align:start position:0% +mini-batches your method starts + + + align:start position:0% +mini-batches your method starts +resembling gradient descent that means + + align:start position:0% +resembling gradient descent that means + + + align:start position:0% +resembling gradient descent that means +it decreases noise so much so that this + + align:start position:0% +it decreases noise so much so that this + + + align:start position:0% +it decreases noise so much so that this +region of confusion shrinks so much + + align:start position:0% +region of confusion shrinks so much + + + align:start position:0% +region of confusion shrinks so much +which all sounds good but it ends up + + align:start position:0% +which all sounds good but it ends up + + + align:start position:0% +which all sounds good but it ends up +being really bad for machine learning + + align:start position:0% +being really bad for machine learning + + + align:start position:0% +being really bad for machine learning +that's what I said that in machine + + align:start position:0% +that's what I said that in machine + + + align:start position:0% +that's what I said that in machine +learning you want some region of + + align:start position:0% +learning you want some region of + + + align:start position:0% +learning you want some region of +uncertainty and what it means actually + + align:start position:0% +uncertainty and what it means actually + + + align:start position:0% +uncertainty and what it means actually +is a lot of people are have been working + + align:start position:0% +is a lot of people are have been working + + + align:start position:0% +is a lot of people are have been working +on this including at big companies that + + align:start position:0% +on this including at big companies that + + + align:start position:0% +on this including at big companies that +if you reduce that region of uncertainty + + align:start position:0% +if you reduce that region of uncertainty + + + align:start position:0% +if you reduce that region of uncertainty +too much you end up overfitting your + + align:start position:0% +too much you end up overfitting your + + + align:start position:0% +too much you end up overfitting your +neural network and then it starts + + align:start position:0% +neural network and then it starts + + + align:start position:0% +neural network and then it starts +sucking in its test data unseen data + + align:start position:0% +sucking in its test data unseen data + + + align:start position:0% +sucking in its test data unseen data +performance so even though for + + align:start position:0% +performance so even though for + + + align:start position:0% +performance so even though for +parallelism programming optimization + + align:start position:0% +parallelism programming optimization + + + align:start position:0% +parallelism programming optimization +Theory big mini-batch is awesome + + align:start position:0% +Theory big mini-batch is awesome + + + align:start position:0% +Theory big mini-batch is awesome +unfortunately there's price to be paid + + align:start position:0% +unfortunately there's price to be paid + + + align:start position:0% +unfortunately there's price to be paid +it hurts your test error performance and + + align:start position:0% +it hurts your test error performance and + + + align:start position:0% +it hurts your test error performance and +there all sorts of methods people are + + align:start position:0% +there all sorts of methods people are + + + align:start position:0% +there all sorts of methods people are +trying to cook up including shrinking + + align:start position:0% +trying to cook up including shrinking + + + align:start position:0% +trying to cook up including shrinking +data accordingly or changing neural + + align:start position:0% +data accordingly or changing neural + + + align:start position:0% +data accordingly or changing neural +network architecture and all sorts of + + align:start position:0% +network architecture and all sorts of + + + align:start position:0% +network architecture and all sorts of +ideas you can cook up your ideas for + + align:start position:0% +ideas you can cook up your ideas for + + + align:start position:0% +ideas you can cook up your ideas for +your favorite architecture how to make a + + align:start position:0% +your favorite architecture how to make a + + + align:start position:0% +your favorite architecture how to make a +large mini batch without hurting the + + align:start position:0% +large mini batch without hurting the + + + align:start position:0% +large mini batch without hurting the +final performance but it's still + + align:start position:0% +final performance but it's still + + + align:start position:0% +final performance but it's still +somewhat of an open question on how to + + align:start position:0% +somewhat of an open question on how to + + + align:start position:0% +somewhat of an open question on how to +optimally select which many larger + + align:start position:0% +optimally select which many larger + + + align:start position:0% +optimally select which many larger +mini-batch so should be so even though + + align:start position:0% +mini-batch so should be so even though + + + align:start position:0% +mini-batch so should be so even though +these ideas are simple you see that + + align:start position:0% +these ideas are simple you see that + + + align:start position:0% +these ideas are simple you see that +every simple idea leads to an entire sub + + align:start position:0% +every simple idea leads to an entire sub + + + align:start position:0% +every simple idea leads to an entire sub +area of SGD so here are practical + + align:start position:0% +area of SGD so here are practical + + + align:start position:0% +area of SGD so here are practical +challenges people have various + + align:start position:0% +challenges people have various + + + align:start position:0% +challenges people have various +heuristics for solving these challenges + + align:start position:0% +heuristics for solving these challenges + + + align:start position:0% +heuristics for solving these challenges +you can cook up your own but it's not + + align:start position:0% +you can cook up your own but it's not + + + align:start position:0% +you can cook up your own but it's not +that one idea always works so if you + + align:start position:0% +that one idea always works so if you + + + align:start position:0% +that one idea always works so if you +look at SGD what are the moving parts + + align:start position:0% +look at SGD what are the moving parts + + + align:start position:0% +look at SGD what are the moving parts +the moving parts in SGD the gradients + + align:start position:0% +the moving parts in SGD the gradients + + + align:start position:0% +the moving parts in SGD the gradients +stochastic gradients the step size the + + align:start position:0% +stochastic gradients the step size the + + + align:start position:0% +stochastic gradients the step size the +mini batch so + + align:start position:0% +mini batch so + + + align:start position:0% +mini batch so +how should I pick step sizes very + + align:start position:0% +how should I pick step sizes very + + + align:start position:0% +how should I pick step sizes very +non-trivial problem different deep + + align:start position:0% +non-trivial problem different deep + + + align:start position:0% +non-trivial problem different deep +learning toolkits may have different + + align:start position:0% +learning toolkits may have different + + + align:start position:0% +learning toolkits may have different +ways of automating that tuning but it's + + align:start position:0% +ways of automating that tuning but it's + + + align:start position:0% +ways of automating that tuning but it's +one of the painful things which + + align:start position:0% +one of the painful things which + + + align:start position:0% +one of the painful things which +mini-batch to use with replacement + + align:start position:0% +mini-batch to use with replacement + + + align:start position:0% +mini-batch to use with replacement +without replacement I already showed you + + align:start position:0% +without replacement I already showed you + + + align:start position:0% +without replacement I already showed you +but which mini-batch should I use how + + align:start position:0% +but which mini-batch should I use how + + + align:start position:0% +but which mini-batch should I use how +large that should be again not an easy + + align:start position:0% +large that should be again not an easy + + + align:start position:0% +large that should be again not an easy +question to answer how to compute + + align:start position:0% +question to answer how to compute + + + align:start position:0% +question to answer how to compute +stochastic gradients does anybody know + + align:start position:0% +stochastic gradients does anybody know + + + align:start position:0% +stochastic gradients does anybody know +how stochastic gradients are computed + + align:start position:0% +how stochastic gradients are computed + + + align:start position:0% +how stochastic gradients are computed +for deep Network training anybody know + + align:start position:0% + + + + align:start position:0% + +there is a very famous algorithm called + + align:start position:0% +there is a very famous algorithm called + + + align:start position:0% +there is a very famous algorithm called +back propagation that back propagation + + align:start position:0% +back propagation that back propagation + + + align:start position:0% +back propagation that back propagation +algorithm is used to compute a single + + align:start position:0% +algorithm is used to compute a single + + + align:start position:0% +algorithm is used to compute a single +stochastic gradient some people use the + + align:start position:0% +stochastic gradient some people use the + + + align:start position:0% +stochastic gradient some people use the +word back prop to mean SGD but what back + + align:start position:0% +word back prop to mean SGD but what back + + + align:start position:0% +word back prop to mean SGD but what back +prop really means is some some kind of + + align:start position:0% +prop really means is some some kind of + + + align:start position:0% +prop really means is some some kind of +algorithm which computes for you a + + align:start position:0% +algorithm which computes for you a + + + align:start position:0% +algorithm which computes for you a +single stochastic gradient and hence you + + align:start position:0% +single stochastic gradient and hence you + + + align:start position:0% +single stochastic gradient and hence you +know this tensorflow etc these toolkits + + align:start position:0% +know this tensorflow etc these toolkits + + + align:start position:0% +know this tensorflow etc these toolkits +they come up with all sorts of ways to + + align:start position:0% +they come up with all sorts of ways to + + + align:start position:0% +they come up with all sorts of ways to +automate the computation of a gradient + + align:start position:0% +automate the computation of a gradient + + + align:start position:0% +automate the computation of a gradient +because really that's the main thing and + + align:start position:0% +because really that's the main thing and + + + align:start position:0% +because really that's the main thing and +then other ideas like gradient clipping + + align:start position:0% +then other ideas like gradient clipping + + + align:start position:0% +then other ideas like gradient clipping +and momentum etc there's a bunch of + + align:start position:0% +and momentum etc there's a bunch of + + + align:start position:0% +and momentum etc there's a bunch of +other ideas and the theoretical + + align:start position:0% +other ideas and the theoretical + + + align:start position:0% +other ideas and the theoretical +challenges I mentioned to you already + + align:start position:0% +challenges I mentioned to you already + + + align:start position:0% +challenges I mentioned to you already +proving that it works that it actually + + align:start position:0% +proving that it works that it actually + + + align:start position:0% +proving that it works that it actually +solves what it set out to do + + align:start position:0% +solves what it set out to do + + + align:start position:0% +solves what it set out to do +unfortunately I was too slow I couldn't + + align:start position:0% +unfortunately I was too slow I couldn't + + + align:start position:0% +unfortunately I was too slow I couldn't +show you the awesome five line proof + + align:start position:0% +show you the awesome five line proof + + + align:start position:0% +show you the awesome five line proof +that I have that SGD works for neural + + align:start position:0% +that I have that SGD works for neural + + + align:start position:0% +that I have that SGD works for neural +networks and theoretical analysis as I + + align:start position:0% +networks and theoretical analysis as I + + + align:start position:0% +networks and theoretical analysis as I +said it's really lagging my proof also + + align:start position:0% +said it's really lagging my proof also + + + align:start position:0% +said it's really lagging my proof also +uses the with replacement and the + + align:start position:0% +uses the with replacement and the + + + align:start position:0% +uses the with replacement and the +without replacement version which is the + + align:start position:0% +without replacement version which is the + + + align:start position:0% +without replacement version which is the +one that is actually implemented there's + + align:start position:0% +one that is actually implemented there's + + + align:start position:0% +one that is actually implemented there's +very little progress on that there is + + align:start position:0% +very little progress on that there is + + + align:start position:0% +very little progress on that there is +some progress there's a bunch of papers + + align:start position:0% +some progress there's a bunch of papers + + + align:start position:0% +some progress there's a bunch of papers +including from our colleagues at MIT but + + align:start position:0% +including from our colleagues at MIT but + + + align:start position:0% +including from our colleagues at MIT but +it's quite unsolved and the biggest + + align:start position:0% +it's quite unsolved and the biggest + + + align:start position:0% +it's quite unsolved and the biggest +question which most of the people in + + align:start position:0% +question which most of the people in + + + align:start position:0% +question which most of the people in +machine learning are currently excited + + align:start position:0% +machine learning are currently excited + + + align:start position:0% +machine learning are currently excited +about these days is stuff like why does + + align:start position:0% +about these days is stuff like why does + + + align:start position:0% +about these days is stuff like why does +SGD work so well for neural networks we + + align:start position:0% +SGD work so well for neural networks we + + + align:start position:0% +SGD work so well for neural networks we +use this crappy optimization method it + + align:start position:0% +use this crappy optimization method it + + + align:start position:0% +use this crappy optimization method it +very rapidly does some fitting data is + + align:start position:0% +very rapidly does some fitting data is + + + align:start position:0% +very rapidly does some fitting data is +large neural network is large + + align:start position:0% +large neural network is large + + + align:start position:0% +large neural network is large +and then this neural network ends up + + align:start position:0% +and then this neural network ends up + + + align:start position:0% +and then this neural network ends up +having great classification performance + + align:start position:0% +having great classification performance + + + align:start position:0% +having great classification performance +why is that happening + + align:start position:0% +why is that happening + + + align:start position:0% +why is that happening +it's called trying to explain build a + + align:start position:0% +it's called trying to explain build a + + + align:start position:0% +it's called trying to explain build a +theory of generalization why does this + + align:start position:0% +theory of generalization why does this + + + align:start position:0% +theory of generalization why does this +an SGD train neural network work better + + align:start position:0% +an SGD train neural network work better + + + align:start position:0% +an SGD train neural network work better +than neural networks train with more + + align:start position:0% +than neural networks train with more + + + align:start position:0% +than neural networks train with more +fancy optimization methods it's a + + align:start position:0% +fancy optimization methods it's a + + + align:start position:0% +fancy optimization methods it's a +mystery and most of the people who take + + align:start position:0% +mystery and most of the people who take + + + align:start position:0% +mystery and most of the people who take +interest in theoretical machine learning + + align:start position:0% +interest in theoretical machine learning + + + align:start position:0% +interest in theoretical machine learning +and statistics that is one of the + + align:start position:0% +and statistics that is one of the + + + align:start position:0% +and statistics that is one of the +mysteries they are trying to understand + + align:start position:0% +mysteries they are trying to understand + + + align:start position:0% +mysteries they are trying to understand +so I think that's my story of SGD and + + align:start position:0% +so I think that's my story of SGD and + + + align:start position:0% +so I think that's my story of SGD and +this is the part we skip but it's ok the + + align:start position:0% +this is the part we skip but it's ok the + + + align:start position:0% +this is the part we skip but it's ok the +the intuition behind SGD is much more + + align:start position:0% +the intuition behind SGD is much more + + + align:start position:0% +the intuition behind SGD is much more +important than this so I think exactly + + align:start position:0% +important than this so I think exactly + + + align:start position:0% +important than this so I think exactly +yeah I think so that they'll be great \ No newline at end of file diff --git a/kZkLqCdMXWY.txt b/kZkLqCdMXWY.txt new file mode 100644 index 0000000000000000000000000000000000000000..14d4227cac904804ec57a15a85a33468bde0fe75 --- /dev/null +++ b/kZkLqCdMXWY.txt @@ -0,0 +1,15963 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu there are a lot of ideas in + + align:start position:0% +ocw.mit.edu there are a lot of ideas in + + + align:start position:0% +ocw.mit.edu there are a lot of ideas in +chapter + + align:start position:0% +chapter + + + align:start position:0% +chapter +for uh about a quarter of them are uh + + align:start position:0% +for uh about a quarter of them are uh + + + align:start position:0% +for uh about a quarter of them are uh +Rewritten from the Society of + + align:start position:0% +Rewritten from the Society of + + + align:start position:0% +Rewritten from the Society of +Mind and + + align:start position:0% +Mind and + + + align:start position:0% +Mind and +uh it isn't until the next chapter that + + align:start position:0% +uh it isn't until the next chapter that + + + align:start position:0% +uh it isn't until the next chapter that +right in the middle of the book that I + + align:start position:0% +right in the middle of the book that I + + + align:start position:0% +right in the middle of the book that I +try to describe the mind is made of a + + align:start position:0% +try to describe the mind is made of a + + + align:start position:0% +try to describe the mind is made of a +big stack of six different layers of I + + align:start position:0% +big stack of six different layers of I + + + align:start position:0% +big stack of six different layers of I +guess the introduction mentioned that + + align:start position:0% +guess the introduction mentioned that + + + align:start position:0% +guess the introduction mentioned that +but uh six different layers of + + align:start position:0% +but uh six different layers of + + + align:start position:0% +but uh six different layers of +structures Each of which reacts to + + align:start position:0% +structures Each of which reacts to + + + align:start position:0% +structures Each of which reacts to +what's happening in the layer below it + + align:start position:0% +what's happening in the layer below it + + + align:start position:0% +what's happening in the layer below it +and and that's something we sometimes + + align:start position:0% +and and that's something we sometimes + + + align:start position:0% +and and that's something we sometimes +call model six for no particular + + align:start position:0% +call model six for no particular + + + align:start position:0% +call model six for no particular +reason and uh so in + + align:start position:0% + + + + align:start position:0% + +the sort of at this section in + + align:start position:0% + + + + align:start position:0% + +the in chapter 4 it talks about the idea + + align:start position:0% +the in chapter 4 it talks about the idea + + + align:start position:0% +the in chapter 4 it talks about the idea +that in the early days of psychology + + align:start position:0% +that in the early days of psychology + + + align:start position:0% +that in the early days of psychology +well around + + align:start position:0% +well around + + + align:start position:0% +well around +1900 uh there were some very simple + + align:start position:0% +1900 uh there were some very simple + + + align:start position:0% +1900 uh there were some very simple +theories based on uh various experiments + + align:start position:0% +theories based on uh various experiments + + + align:start position:0% +theories based on uh various experiments +with rats and other + + align:start position:0% +with rats and other + + + align:start position:0% +with rats and other +uh shouldn't call them simple + + align:start position:0% +uh shouldn't call them simple + + + align:start position:0% +uh shouldn't call them simple +mammals if you think about it the animal + + align:start position:0% +mammals if you think about it the animal + + + align:start position:0% +mammals if you think about it the animal +the small mammals like rats and + + align:start position:0% +the small mammals like rats and + + + align:start position:0% +the small mammals like rats and +mice what did it + + align:start position:0% +mice what did it + + + align:start position:0% +mice what did it +do in the + + align:start position:0% +do in the + + + align:start position:0% +do in the +very when I say early days of psychology + + align:start position:0% +very when I say early days of psychology + + + align:start position:0% +very when I say early days of psychology +that's a strange thing to say because if + + align:start position:0% +that's a strange thing to say because if + + + align:start position:0% +that's a strange thing to say because if +you + + align:start position:0% +you + + + align:start position:0% +you +read + + align:start position:0% +read + + + align:start position:0% +read +Aristotle's book on rhetoric which is a + + align:start position:0% +Aristotle's book on rhetoric which is a + + + align:start position:0% +Aristotle's book on rhetoric which is a +fairly big one it's full of ideas about + + align:start position:0% +fairly big one it's full of ideas about + + + align:start position:0% +fairly big one it's full of ideas about +how the mind works and then if uh then I + + align:start position:0% +how the mind works and then if uh then I + + + align:start position:0% +how the mind works and then if uh then I +don't know very much in between but if + + align:start position:0% +don't know very much in between but if + + + align:start position:0% +don't know very much in between but if +you go to the era of English + + align:start position:0% +you go to the era of English + + + align:start position:0% +you go to the era of English +philosophers like + + align:start position:0% +philosophers like + + + align:start position:0% +philosophers like +Hume and so forth then you uh see + + align:start position:0% +Hume and so forth then you uh see + + + align:start position:0% +Hume and so forth then you uh see +theories well hum is kind of strange + + align:start position:0% +theories well hum is kind of strange + + + align:start position:0% +theories well hum is kind of strange +theories about the associations of ideas + + align:start position:0% +theories about the associations of ideas + + + align:start position:0% +theories about the associations of ideas +and so forth and at the beginning of the + + align:start position:0% +and so forth and at the beginning of the + + + align:start position:0% +and so forth and at the beginning of the +19th century we find people like Watson + + align:start position:0% +19th century we find people like Watson + + + align:start position:0% +19th century we find people like Watson +and Pavlov who invent a very simple form + + align:start position:0% +and Pavlov who invent a very simple form + + + align:start position:0% +and Pavlov who invent a very simple form +of rule-based system uh that Pavlov + + align:start position:0% +of rule-based system uh that Pavlov + + + align:start position:0% +of rule-based system uh that Pavlov +called conditioned + + align:start position:0% +called conditioned + + + align:start position:0% +called conditioned +reflexes + + align:start position:0% +reflexes + + + align:start position:0% +reflexes +and uh in these descriptions of + + align:start position:0% +and uh in these descriptions of + + + align:start position:0% +and uh in these descriptions of +psychology This was later elaborated by + + align:start position:0% +psychology This was later elaborated by + + + align:start position:0% +psychology This was later elaborated by +B F Skinner who was a very famous + + align:start position:0% +B F Skinner who was a very famous + + + align:start position:0% +B F Skinner who was a very famous +psychologist of the + + align:start position:0% +psychologist of the + + + align:start position:0% +psychologist of the +1930s through + + align:start position:0% +1930s through + + + align:start position:0% +1930s through +7s and + + align:start position:0% +7s and + + + align:start position:0% +7s and +uh I made friends with him when I was an + + align:start position:0% +uh I made friends with him when I was an + + + align:start position:0% +uh I made friends with him when I was an +undergraduate at Harvard + + align:start position:0% +undergraduate at Harvard + + + align:start position:0% +undergraduate at Harvard +and played around with I was good at + + align:start position:0% +and played around with I was good at + + + align:start position:0% +and played around with I was good at +Electronics so I helped with the + + align:start position:0% +Electronics so I helped with the + + + align:start position:0% +Electronics so I helped with the +instrumentation uh what Pavlov and and + + align:start position:0% +instrumentation uh what Pavlov and and + + + align:start position:0% +instrumentation uh what Pavlov and and +those people did at the beginning of the + + align:start position:0% +those people did at the beginning of the + + + align:start position:0% +those people did at the beginning of the +19th century was do systematic + + align:start position:0% +19th century was do systematic + + + align:start position:0% +19th century was do systematic +experiments on animals + + align:start position:0% +experiments on animals + + + align:start position:0% +experiments on animals +and the standard Theory became what is + + align:start position:0% +and the standard Theory became what is + + + align:start position:0% +and the standard Theory became what is +now called reinforcement Theory you put + + align:start position:0% +now called reinforcement Theory you put + + + align:start position:0% +now called reinforcement Theory you put +the animal in a situation uh for + + align:start position:0% +the animal in a situation uh for + + + align:start position:0% +the animal in a situation uh for +example uh in Skinner what Skinner did + + align:start position:0% +example uh in Skinner what Skinner did + + + align:start position:0% +example uh in Skinner what Skinner did +was make the study of animal behavior + + align:start position:0% +was make the study of animal behavior + + + align:start position:0% +was make the study of animal behavior +sort of scientific in the sense that he + + align:start position:0% +sort of scientific in the sense that he + + + align:start position:0% +sort of scientific in the sense that he +restricted all sorts of variables what + + align:start position:0% +restricted all sorts of variables what + + + align:start position:0% +restricted all sorts of variables what +Pavlov did is he would uh + + align:start position:0% +Pavlov did is he would uh + + + align:start position:0% +Pavlov did is he would uh +uh uh show something to a dog maybe a + + align:start position:0% +uh uh show something to a dog maybe a + + + align:start position:0% +uh uh show something to a dog maybe a +piece of meat uh I'm sorry maybe uh play + + align:start position:0% +piece of meat uh I'm sorry maybe uh play + + + align:start position:0% +piece of meat uh I'm sorry maybe uh play +a certain sound and if the dog uh did + + align:start position:0% +a certain sound and if the dog uh did + + + align:start position:0% +a certain sound and if the dog uh did +something like + + align:start position:0% +something like + + + align:start position:0% +something like +sit uh then Pavlov would reward it with + + align:start position:0% +sit uh then Pavlov would reward it with + + + align:start position:0% +sit uh then Pavlov would reward it with +something that acts as a reward for the + + align:start position:0% +something that acts as a reward for the + + + align:start position:0% +something that acts as a reward for the +animal uh so that's called a conditioned + + align:start position:0% +animal uh so that's called a conditioned + + + align:start position:0% +animal uh so that's called a conditioned +reflex uh you have a certain stimulus + + align:start position:0% +reflex uh you have a certain stimulus + + + align:start position:0% +reflex uh you have a certain stimulus +the animal could do a variety of things + + align:start position:0% +the animal could do a variety of things + + + align:start position:0% +the animal could do a variety of things +and you pick a particular one and you + + align:start position:0% +and you pick a particular one and you + + + align:start position:0% +and you pick a particular one and you +reward the animal if it does that + + align:start position:0% +reward the animal if it does that + + + align:start position:0% +reward the animal if it does that +particular one and then after a couple + + align:start position:0% +particular one and then after a couple + + + align:start position:0% +particular one and then after a couple +of 100 trials the dog will do exactly + + align:start position:0% +of 100 trials the dog will do exactly + + + align:start position:0% +of 100 trials the dog will do exactly +what you have been rewarding it for very + + align:start position:0% +what you have been rewarding it for very + + + align:start position:0% +what you have been rewarding it for very +reliably then if + + align:start position:0% +reliably then if + + + align:start position:0% +reliably then if +you provide the stimulus + + align:start position:0% +you provide the stimulus + + + align:start position:0% +you provide the stimulus +again + + align:start position:0% +again + + + align:start position:0% +again +uh and the animal sits or whatever you + + align:start position:0% +uh and the animal sits or whatever you + + + align:start position:0% +uh and the animal sits or whatever you +want it to + + align:start position:0% +want it to + + + align:start position:0% +want it to +do if you well the stimulus could just + + align:start position:0% +do if you well the stimulus could just + + + align:start position:0% +do if you well the stimulus could just +sit if you say sit the dog will do + + align:start position:0% +sit if you say sit the dog will do + + + align:start position:0% +sit if you say sit the dog will do +something or other or whatever it does + + align:start position:0% +something or other or whatever it does + + + align:start position:0% +something or other or whatever it does +you can regard as its response and uh if + + align:start position:0% +you can regard as its response and uh if + + + align:start position:0% +you can regard as its response and uh if +it's the response you like you reward it + + align:start position:0% +it's the response you like you reward it + + + align:start position:0% +it's the response you like you reward it +after it's very well trained to do + + align:start position:0% +after it's very well trained to do + + + align:start position:0% +after it's very well trained to do +that + + align:start position:0% +that + + + align:start position:0% +that +uh what happens if you say sit and it + + align:start position:0% +uh what happens if you say sit and it + + + align:start position:0% +uh what happens if you say sit and it +doesn't sit I'm sorry and you don't if + + align:start position:0% +doesn't sit I'm sorry and you don't if + + + align:start position:0% +doesn't sit I'm sorry and you don't if +it sits and you don't reward it uh well + + align:start position:0% +it sits and you don't reward it uh well + + + align:start position:0% +it sits and you don't reward it uh well +then it'll look + + align:start position:0% +then it'll look + + + align:start position:0% +then it'll look +puzzled and uh if you do that a few + + align:start position:0% +puzzled and uh if you do that a few + + + align:start position:0% +puzzled and uh if you do that a few +times + + align:start position:0% +times + + + align:start position:0% +times +then you'll find that when you say sit + + align:start position:0% +then you'll find that when you say sit + + + align:start position:0% +then you'll find that when you say sit +it doesn't properly sit and in fact if + + align:start position:0% +it doesn't properly sit and in fact if + + + align:start position:0% +it doesn't properly sit and in fact if +youve rewarded it a thousand times and + + align:start position:0% +youve rewarded it a thousand times and + + + align:start position:0% +youve rewarded it a thousand times and +then you give this command uh maybe 20 + + align:start position:0% +then you give this command uh maybe 20 + + + align:start position:0% +then you give this command uh maybe 20 +times in a row and don't reward it then + + align:start position:0% +times in a row and don't reward it then + + + align:start position:0% +times in a row and don't reward it then +the 21st time it probably won't + + align:start position:0% +the 21st time it probably won't + + + align:start position:0% +the 21st time it probably won't +sit it's as though it erased the rule + + align:start position:0% +sit it's as though it erased the rule + + + align:start position:0% +sit it's as though it erased the rule +what Skinner + + align:start position:0% +what Skinner + + + align:start position:0% +what Skinner +discovered + + align:start position:0% +discovered + + + align:start position:0% +discovered +uh made a revolution in animal training + + align:start position:0% +uh made a revolution in animal training + + + align:start position:0% +uh made a revolution in animal training +I imagine a lot of lot of animal + + align:start position:0% +I imagine a lot of lot of animal + + + align:start position:0% +I imagine a lot of lot of animal +trainers knew this but they didn't + + align:start position:0% +trainers knew this but they didn't + + + align:start position:0% +trainers knew this but they didn't +publish in journals Skinner discovered + + align:start position:0% +publish in journals Skinner discovered + + + align:start position:0% +publish in journals Skinner discovered +that uh if you reward the animal every + + align:start position:0% +that uh if you reward the animal every + + + align:start position:0% +that uh if you reward the animal every +time then it's then it gets trained to + + align:start position:0% +time then it's then it gets trained to + + + align:start position:0% +time then it's then it gets trained to +produce this stimulus response event + + align:start position:0% +produce this stimulus response event + + + align:start position:0% +produce this stimulus response event +very + + align:start position:0% +very + + + align:start position:0% +very +reliably and if you stop rewarding it + + align:start position:0% +reliably and if you stop rewarding it + + + align:start position:0% +reliably and if you stop rewarding it +then it rather quickly uh stops + + align:start position:0% +then it rather quickly uh stops + + + align:start position:0% +then it rather quickly uh stops +responding in the way you've trained it + + align:start position:0% +responding in the way you've trained it + + + align:start position:0% +responding in the way you've trained it +and you might say it's + + align:start position:0% +and you might say it's + + + align:start position:0% +and you might say it's +forgotten uh + + align:start position:0% +forgotten uh + + + align:start position:0% +forgotten uh +however Skinner discovered that if you + + align:start position:0% +however Skinner discovered that if you + + + align:start position:0% +however Skinner discovered that if you +start to train it again it will very + + align:start position:0% +start to train it again it will very + + + align:start position:0% +start to train it again it will very +quickly learn maybe it will start + + align:start position:0% +quickly learn maybe it will start + + + align:start position:0% +quickly learn maybe it will start +reliably responding in just 20 trials + + align:start position:0% +reliably responding in just 20 trials + + + align:start position:0% +reliably responding in just 20 trials +instead of the maybe couple of hundred + + align:start position:0% +instead of the maybe couple of hundred + + + align:start position:0% +instead of the maybe couple of hundred +or whatever it took the first time but + + align:start position:0% +or whatever it took the first time but + + + align:start position:0% +or whatever it took the first time but +Skinner discovered another thing that + + align:start position:0% +Skinner discovered another thing that + + + align:start position:0% +Skinner discovered another thing that +hadn't uh been observed by animal + + align:start position:0% +hadn't uh been observed by animal + + + align:start position:0% +hadn't uh been observed by animal +behaviorists what happens if you tell + + align:start position:0% +behaviorists what happens if you tell + + + align:start position:0% +behaviorists what happens if you tell +the dog to sit and it does and you + + align:start position:0% +the dog to sit and it does and you + + + align:start position:0% +the dog to sit and it does and you +rewarded only say one out of every five + + align:start position:0% +rewarded only say one out of every five + + + align:start position:0% +rewarded only say one out of every five +times then it'll take a little longer to + + align:start position:0% +times then it'll take a little longer to + + + align:start position:0% +times then it'll take a little longer to +train but not + + align:start position:0% +train but not + + + align:start position:0% +train but not +much and then if you start saying sit + + align:start position:0% +much and then if you start saying sit + + + align:start position:0% +much and then if you start saying sit +and don't reward it it + + align:start position:0% +and don't reward it it + + + align:start position:0% +and don't reward it it +might continue to obey the command + + align:start position:0% +might continue to obey the command + + + align:start position:0% +might continue to obey the command +reliably for a couple of hundred times + + align:start position:0% +reliably for a couple of hundred times + + + align:start position:0% +reliably for a couple of hundred times +in other words intermittent unreliable + + align:start position:0% +in other words intermittent unreliable + + + align:start position:0% +in other words intermittent unreliable +reinforcement and and Skinner would have + + align:start position:0% +reinforcement and and Skinner would have + + + align:start position:0% +reinforcement and and Skinner would have +a random interval uh if you in fact + + align:start position:0% +a random interval uh if you in fact + + + align:start position:0% +a random interval uh if you in fact +rewarded it every five times uh some + + align:start position:0% +rewarded it every five times uh some + + + align:start position:0% +rewarded it every five times uh some +dogs would actually + + align:start position:0% +dogs would actually + + + align:start position:0% +dogs would actually +uh wait for you to order it five times + + align:start position:0% +uh wait for you to order it five times + + + align:start position:0% +uh wait for you to order it five times +before it sits uh but if you did it + + align:start position:0% +before it sits uh but if you did it + + + align:start position:0% +before it sits uh but if you did it +randomly so that it couldn't predict + + align:start position:0% +randomly so that it couldn't predict + + + align:start position:0% +randomly so that it couldn't predict +when the next reward was then it + + align:start position:0% +when the next reward was then it + + + align:start position:0% +when the next reward was then it +sometimes took as many as 50 or a 100 + + align:start position:0% +sometimes took as many as 50 or a 100 + + + align:start position:0% +sometimes took as many as 50 or a 100 +times as long to make that response + + align:start position:0% +times as long to make that response + + + align:start position:0% +times as long to make that response +disappear U anyway that's that's + + align:start position:0% +disappear U anyway that's that's + + + align:start position:0% +disappear U anyway that's that's +something that uh isn't really often + + align:start position:0% +something that uh isn't really often + + + align:start position:0% +something that uh isn't really often +described in in the older + + align:start position:0% +described in in the older + + + align:start position:0% +described in in the older +textbooks on conditioned reflexes + + align:start position:0% +textbooks on conditioned reflexes + + + align:start position:0% +textbooks on conditioned reflexes +because it hadn't been + + align:start position:0% +because it hadn't been + + + align:start position:0% +because it hadn't been +known uh so there's when you extinguish + + align:start position:0% +known uh so there's when you extinguish + + + align:start position:0% +known uh so there's when you extinguish +a response in an animal that's been reli + + align:start position:0% +a response in an animal that's been reli + + + align:start position:0% +a response in an animal that's been reli +been constantly trained it hasn't really + + align:start position:0% +been constantly trained it hasn't really + + + align:start position:0% +been constantly trained it hasn't really +forgotten it it's somehow suppressing it + + align:start position:0% +forgotten it it's somehow suppressing it + + + align:start position:0% +forgotten it it's somehow suppressing it +and uh that was one of the reasons that + + align:start position:0% +and uh that was one of the reasons that + + + align:start position:0% +and uh that was one of the reasons that +I began to think about critics and about + + align:start position:0% +I began to think about critics and about + + + align:start position:0% +I began to think about critics and about +sensors that a memory isn't erased by + + align:start position:0% +sensors that a memory isn't erased by + + + align:start position:0% +sensors that a memory isn't erased by +non-use but it may actually get + + align:start position:0% +non-use but it may actually get + + + align:start position:0% +non-use but it may actually get +suppressed if it turns out that that + + align:start position:0% +suppressed if it turns out that that + + + align:start position:0% +suppressed if it turns out that that +response doesn't + + align:start position:0% +response doesn't + + + align:start position:0% +response doesn't +lead to success for a while so in other + + align:start position:0% +lead to success for a while so in other + + + align:start position:0% +lead to success for a while so in other +words the animal will persist much + + align:start position:0% +words the animal will persist much + + + align:start position:0% +words the animal will persist much +longer if it was randomly rewarded and + + align:start position:0% +longer if it was randomly rewarded and + + + align:start position:0% +longer if it was randomly rewarded and +again when you start rewarding it more + + align:start position:0% +again when you start rewarding it more + + + align:start position:0% +again when you start rewarding it more +often it will almost instantly jump back + + align:start position:0% +often it will almost instantly jump back + + + align:start position:0% +often it will almost instantly jump back +to the previous level of of responding + + align:start position:0% +to the previous level of of responding + + + align:start position:0% +to the previous level of of responding +reliably so that suggests that uh you're + + align:start position:0% +reliably so that suggests that uh you're + + + align:start position:0% +reliably so that suggests that uh you're +not + + align:start position:0% +not + + + align:start position:0% +not +changing now you can look at conditioned + + align:start position:0% +changing now you can look at conditioned + + + align:start position:0% +changing now you can look at conditioned +reflexes as what uh AI researchers call + + align:start position:0% +reflexes as what uh AI researchers call + + + align:start position:0% +reflexes as what uh AI researchers call +rule-based systems namely the you can + + align:start position:0% +rule-based systems namely the you can + + + align:start position:0% +rule-based systems namely the you can +think of the poor animal as just a + + align:start position:0% +think of the poor animal as just a + + + align:start position:0% +think of the poor animal as just a +catalog of uh two-part rules if this + + align:start position:0% +catalog of uh two-part rules if this + + + align:start position:0% +catalog of uh two-part rules if this +happens do that if this happens do that + + align:start position:0% +happens do that if this happens do that + + + align:start position:0% +happens do that if this happens do that +and around + + align:start position:0% +and around + + + align:start position:0% +and around +1980 one of the reasons why artificial + + align:start position:0% +1980 one of the reasons why artificial + + + align:start position:0% +1980 one of the reasons why artificial +intelligence stopped making + + align:start position:0% +intelligence stopped making + + + align:start position:0% +intelligence stopped making +progress is that before + + align:start position:0% +progress is that before + + + align:start position:0% +progress is that before +1980 uh lots of us worked on uh getting + + align:start position:0% +1980 uh lots of us worked on uh getting + + + align:start position:0% +1980 uh lots of us worked on uh getting +computers to solve really hard problems + + align:start position:0% +computers to solve really hard problems + + + align:start position:0% +computers to solve really hard problems +like uh problems in calculus or or + + align:start position:0% +like uh problems in calculus or or + + + align:start position:0% +like uh problems in calculus or or +finding new ways to uh make them better + + align:start position:0% +finding new ways to uh make them better + + + align:start position:0% +finding new ways to uh make them better +at playing games I mean people still + + align:start position:0% +at playing games I mean people still + + + align:start position:0% +at playing games I mean people still +worked on making them play games better + + align:start position:0% +worked on making them play games better + + + align:start position:0% +worked on making them play games better +but as I think I said the other day uh + + align:start position:0% +but as I think I said the other day uh + + + align:start position:0% +but as I think I said the other day uh +when deep blue W the world championship + + align:start position:0% +when deep blue W the world championship + + + align:start position:0% +when deep blue W the world championship +it didn't have a significantly larger + + align:start position:0% +it didn't have a significantly larger + + + align:start position:0% +it didn't have a significantly larger +collection of + + align:start position:0% +collection of + + + align:start position:0% +collection of +strategic uh ideas or knowledge about + + align:start position:0% +strategic uh ideas or knowledge about + + + align:start position:0% +strategic uh ideas or knowledge about +Chess than uh green blats program in 197 + + align:start position:0% +Chess than uh green blats program in 197 + + + align:start position:0% +Chess than uh green blats program in 197 +uh which was the first U chess program + + align:start position:0% +uh which was the first U chess program + + + align:start position:0% +uh which was the first U chess program +that would reliably + + align:start position:0% + + + + align:start position:0% + +beat uh not beginner chess players + + align:start position:0% +beat uh not beginner chess players + + + align:start position:0% +beat uh not beginner chess players +couldn't beat Master chess players but + + align:start position:0% +couldn't beat Master chess players but + + + align:start position:0% +couldn't beat Master chess players but +at an amateur tournament it it turned + + align:start position:0% +at an amateur tournament it it turned + + + align:start position:0% +at an amateur tournament it it turned +over one a few + + align:start position:0% +over one a few + + + align:start position:0% +over one a few +games so there was this idea of a + + align:start position:0% +games so there was this idea of a + + + align:start position:0% +games so there was this idea of a +rule-based system that became very + + align:start position:0% +rule-based system that became very + + + align:start position:0% +rule-based system that became very +popular around 1980 mainly from a PhD + + align:start position:0% +popular around 1980 mainly from a PhD + + + align:start position:0% +popular around 1980 mainly from a PhD +thesis by Ed tigan + + align:start position:0% +thesis by Ed tigan + + + align:start position:0% +thesis by Ed tigan +mam I think was a graduate student at + + align:start position:0% +mam I think was a graduate student at + + + align:start position:0% +mam I think was a graduate student at +Stanford at that time and uh it became + + align:start position:0% +Stanford at that time and uh it became + + + align:start position:0% +Stanford at that time and uh it became +very popular to say could we make + + align:start position:0% +very popular to say could we make + + + align:start position:0% +very popular to say could we make +systems that are just based on rules + + align:start position:0% +systems that are just based on rules + + + align:start position:0% +systems that are just based on rules +without any internal models or + + align:start position:0% +without any internal models or + + + align:start position:0% +without any internal models or +complicated + + align:start position:0% +complicated + + + align:start position:0% +complicated +reflective searches or + + align:start position:0% +reflective searches or + + + align:start position:0% +reflective searches or +whatever uh in the 1980s and progress on + + align:start position:0% +whatever uh in the 1980s and progress on + + + align:start position:0% +whatever uh in the 1980s and progress on +finding good heuristics for improving + + align:start position:0% +finding good heuristics for improving + + + align:start position:0% +finding good heuristics for improving +search processes and so forth sort of + + align:start position:0% +search processes and so forth sort of + + + align:start position:0% +search processes and so forth sort of +appeared + + align:start position:0% +appeared + + + align:start position:0% +appeared +um I just mentioned all that + + align:start position:0% +um I just mentioned all that + + + align:start position:0% +um I just mentioned all that +because + + align:start position:0% +because + + + align:start position:0% +because +uh you don't you see lots of commercial + + align:start position:0% +uh you don't you see lots of commercial + + + align:start position:0% +uh you don't you see lots of commercial +applications of artificial intelligence + + align:start position:0% +applications of artificial intelligence + + + align:start position:0% +applications of artificial intelligence +systems but you don't see ones that do + + align:start position:0% +systems but you don't see ones that do + + + align:start position:0% +systems but you don't see ones that do +dramatically interesting kinds of + + align:start position:0% +dramatically interesting kinds of + + + align:start position:0% +dramatically interesting kinds of +reasoning or problem solving very much + + align:start position:0% +reasoning or problem solving very much + + + align:start position:0% +reasoning or problem solving very much +after + + align:start position:0% +after + + + align:start position:0% +after +that uh so this idea of a rule-based + + align:start position:0% +that uh so this idea of a rule-based + + + align:start position:0% +that uh so this idea of a rule-based +system a collection of if then rules + + align:start position:0% +system a collection of if then rules + + + align:start position:0% +system a collection of if then rules +became popular and + + align:start position:0% + + + + align:start position:0% + +uh uh what I'm suggesting in this early + + align:start position:0% +uh uh what I'm suggesting in this early + + + align:start position:0% +uh uh what I'm suggesting in this early +part of the chapter is + + align:start position:0% +part of the chapter is + + + align:start position:0% +part of the chapter is +that if you're looking at something like + + align:start position:0% +that if you're looking at something like + + + align:start position:0% +that if you're looking at something like +human thinking uh there aren't just + + align:start position:0% +human thinking uh there aren't just + + + align:start position:0% +human thinking uh there aren't just +rules about how to react to an external + + align:start position:0% +rules about how to react to an external + + + align:start position:0% +rules about how to react to an external +situation but there might be a second + + align:start position:0% +situation but there might be a second + + + align:start position:0% +situation but there might be a second +level of the + + align:start position:0% +level of the + + + align:start position:0% +level of the +brain which is regarding the the Pavlov + + align:start position:0% +brain which is regarding the the Pavlov + + + align:start position:0% +brain which is regarding the the Pavlov +and the uh rule based system as its + + align:start position:0% +and the uh rule based system as its + + + align:start position:0% +and the uh rule based system as its +world and the second + + align:start position:0% +world and the second + + + align:start position:0% +world and the second +layer of the brain might be learning + + align:start position:0% +layer of the brain might be learning + + + align:start position:0% +layer of the brain might be learning +some ways to manipulate what happens in + + align:start position:0% +some ways to manipulate what happens in + + + align:start position:0% +some ways to manipulate what happens in +the first world in the U sensory motor + + align:start position:0% +the first world in the U sensory motor + + + align:start position:0% +the first world in the U sensory motor +part of the + + align:start position:0% +part of the + + + align:start position:0% +part of the +system uh why is this + + align:start position:0% +system uh why is this + + + align:start position:0% +system uh why is this +important because if you go back and + + align:start position:0% +important because if you go back and + + + align:start position:0% +important because if you go back and +look + + align:start position:0% +look + + + align:start position:0% +look +at uh Pavlov and even + + align:start position:0% +at uh Pavlov and even + + + align:start position:0% +at uh Pavlov and even +Skinner uh they kept improving their + + align:start position:0% +Skinner uh they kept improving their + + + align:start position:0% +Skinner uh they kept improving their +ideas of under what conditions a rule + + align:start position:0% +ideas of under what conditions a rule + + + align:start position:0% +ideas of under what conditions a rule +gets + + align:start position:0% +gets + + + align:start position:0% +gets +reinforced + + align:start position:0% + + + + align:start position:0% + +but uh when you present the dog or the + + align:start position:0% +but uh when you present the dog or the + + + align:start position:0% +but uh when you present the dog or the +rat with a + + align:start position:0% +rat with a + + + align:start position:0% +rat with a +stimulus + + align:start position:0% +stimulus + + + align:start position:0% +stimulus +uh how does it decide what response to + + align:start position:0% +uh how does it decide what response to + + + align:start position:0% +uh how does it decide what response to +try and you don't see any discussion of + + align:start position:0% +try and you don't see any discussion of + + + align:start position:0% +try and you don't see any discussion of +that uh Skinner made a name for that + + align:start position:0% +that uh Skinner made a name for that + + + align:start position:0% +that uh Skinner made a name for that +that's called operant conditioning + + align:start position:0% +that's called operant conditioning + + + align:start position:0% +that's called operant conditioning +namely put the animal in situation and + + align:start position:0% +namely put the animal in situation and + + + align:start position:0% +namely put the animal in situation and +somehow animal makes a response and then + + align:start position:0% +somehow animal makes a response and then + + + align:start position:0% +somehow animal makes a response and then +the + + align:start position:0% +the + + + align:start position:0% +the +reinforcement May sort of suppress or uh + + align:start position:0% +reinforcement May sort of suppress or uh + + + align:start position:0% +reinforcement May sort of suppress or uh +increase the probability or whatever + + align:start position:0% +increase the probability or whatever + + + align:start position:0% +increase the probability or whatever +however you want to describe it of that + + align:start position:0% +however you want to describe it of that + + + align:start position:0% +however you want to describe it of that +response but there isn't much talk about + + align:start position:0% +response but there isn't much talk about + + + align:start position:0% +response but there isn't much talk about +how it decides what to how to respond + + align:start position:0% +how it decides what to how to respond + + + align:start position:0% +how it decides what to how to respond +does the dog just look up in a table + + align:start position:0% +does the dog just look up in a table + + + align:start position:0% +does the dog just look up in a table +what to do when it hears the phon names + + align:start position:0% +what to do when it hears the phon names + + + align:start position:0% +what to do when it hears the phon names +in the word + + align:start position:0% +in the word + + + align:start position:0% +in the word +sit U well that's what the rulebase + + align:start position:0% +sit U well that's what the rulebase + + + align:start position:0% +sit U well that's what the rulebase +system would require that there's some + + align:start position:0% +system would require that there's some + + + align:start position:0% +system would require that there's some +sort of table which says for each uh + + align:start position:0% +sort of table which says for each uh + + + align:start position:0% +sort of table which says for each uh +input condition what should you do uh + + align:start position:0% +input condition what should you do uh + + + align:start position:0% +input condition what should you do uh +but does the dog say well + + align:start position:0% +but does the dog say well + + + align:start position:0% +but does the dog say well +uh I could do a lot of things uh the + + align:start position:0% +uh I could do a lot of things uh the + + + align:start position:0% +uh I could do a lot of things uh the +last few times that I sat I got a reward + + align:start position:0% +last few times that I sat I got a reward + + + align:start position:0% +last few times that I sat I got a reward +and uh when I didn't sit I didn't get a + + align:start position:0% +and uh when I didn't sit I didn't get a + + + align:start position:0% +and uh when I didn't sit I didn't get a +reward you don't see that kind of + + align:start position:0% +reward you don't see that kind of + + + align:start position:0% +reward you don't see that kind of +thinking in the so-called behaviorist + + align:start position:0% +thinking in the so-called behaviorist + + + align:start position:0% +thinking in the so-called behaviorist +tradition that I've been described ing + + align:start position:0% +tradition that I've been described ing + + + align:start position:0% +tradition that I've been described ing +where you just make a catalog of what + + align:start position:0% +where you just make a catalog of what + + + align:start position:0% +where you just make a catalog of what +are the behavior of the what are the + + align:start position:0% +are the behavior of the what are the + + + align:start position:0% +are the behavior of the what are the +behaviors of the animal and then try to + + align:start position:0% +behaviors of the animal and then try to + + + align:start position:0% +behaviors of the animal and then try to +make a set of rules that explains the + + align:start position:0% +make a set of rules that explains the + + + align:start position:0% +make a set of rules that explains the +behaviors that you've + + align:start position:0% +behaviors that you've + + + align:start position:0% +behaviors that you've +observed where are the rules that + + align:start position:0% + + + + align:start position:0% + +say which behaviors to not + + align:start position:0% +say which behaviors to not + + + align:start position:0% +say which behaviors to not +produce and uh in an ironical way uh uh + + align:start position:0% +produce and uh in an ironical way uh uh + + + align:start position:0% +produce and uh in an ironical way uh uh +Professor Nome Chomsky who's very well + + align:start position:0% +Professor Nome Chomsky who's very well + + + align:start position:0% +Professor Nome Chomsky who's very well +known for having uh sort of won a big + + align:start position:0% +known for having uh sort of won a big + + + align:start position:0% +known for having uh sort of won a big +public argument with + + align:start position:0% +public argument with + + + align:start position:0% +public argument with +Skinner + + align:start position:0% +Skinner + + + align:start position:0% +Skinner +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +has uh been described as the person + + align:start position:0% +has uh been described as the person + + + align:start position:0% +has uh been described as the person +who uh conquered the + + align:start position:0% +who uh conquered the + + + align:start position:0% +who uh conquered the +behaviorists but chsky + + align:start position:0% +behaviorists but chsky + + + align:start position:0% +behaviorists but chsky +himself is very much like Skinner in the + + align:start position:0% +himself is very much like Skinner in the + + + align:start position:0% +himself is very much like Skinner in the +sense that he's taking all the sentences + + align:start position:0% +sense that he's taking all the sentences + + + align:start position:0% +sense that he's taking all the sentences +people you say a lot of sentences to + + align:start position:0% +people you say a lot of sentences to + + + align:start position:0% +people you say a lot of sentences to +people or a lot of strings of words and + + align:start position:0% +people or a lot of strings of words and + + + align:start position:0% +people or a lot of strings of words and +the person has two responses that's a + + align:start position:0% +the person has two responses that's a + + + align:start position:0% +the person has two responses that's a +sentence that's not a + + align:start position:0% +sentence that's not a + + + align:start position:0% +sentence that's not a +sentence then uh Chomsky asks uh what + + align:start position:0% +sentence then uh Chomsky asks uh what + + + align:start position:0% +sentence then uh Chomsky asks uh what +kind + + align:start position:0% +kind + + + align:start position:0% +kind +of Machinery could produce this + + align:start position:0% +of Machinery could produce this + + + align:start position:0% +of Machinery could produce this +particular kind of + + align:start position:0% +particular kind of + + + align:start position:0% +particular kind of +behavior not the behavior of saying + + align:start position:0% +behavior not the behavior of saying + + + align:start position:0% +behavior not the behavior of saying +sentences exactly but the behavior of + + align:start position:0% +sentences exactly but the behavior of + + + align:start position:0% +sentences exactly but the behavior of +which speech actions are called + + align:start position:0% +which speech actions are called + + + align:start position:0% +which speech actions are called +sentences and then he explains that by a + + align:start position:0% +sentences and then he explains that by a + + + align:start position:0% +sentences and then he explains that by a +collection of rules which are at a table + + align:start position:0% +collection of rules which are at a table + + + align:start position:0% +collection of rules which are at a table +because they're more sophisticated and + + align:start position:0% +because they're more sophisticated and + + + align:start position:0% +because they're more sophisticated and +nested which describe the set of all + + align:start position:0% +nested which describe the set of all + + + align:start position:0% +nested which describe the set of all +possible sentences but at least in the + + align:start position:0% +possible sentences but at least in the + + + align:start position:0% +possible sentences but at least in the +older I don't know what chsky has + + align:start position:0% +older I don't know what chsky has + + + align:start position:0% +older I don't know what chsky has +written in the the last decade or so + + align:start position:0% +written in the the last decade or so + + + align:start position:0% +written in the the last decade or so +because I gave up and I may have missed + + align:start position:0% +because I gave up and I may have missed + + + align:start position:0% +because I gave up and I may have missed +some great new ideas but generally his + + align:start position:0% +some great new ideas but generally his + + + align:start position:0% +some great new ideas but generally his +descriptions + + align:start position:0% +descriptions + + + align:start position:0% +descriptions +are ways to describe the set of + + align:start position:0% +are ways to describe the set of + + + align:start position:0% +are ways to describe the set of +acceptable responses or the set of + + align:start position:0% +acceptable responses or the set of + + + align:start position:0% +acceptable responses or the set of +accept of Expressions that are regarded + + align:start position:0% +accept of Expressions that are regarded + + + align:start position:0% +accept of Expressions that are regarded +as s es without a theory of what + + align:start position:0% +as s es without a theory of what + + + align:start position:0% +as s es without a theory of what +produces them so the grammar rules are + + align:start position:0% +produces them so the grammar rules are + + + align:start position:0% +produces them so the grammar rules are +sort of like a rule-based system which + + align:start position:0% +sort of like a rule-based system which + + + align:start position:0% +sort of like a rule-based system which +when apply to an utterance will either + + align:start position:0% +when apply to an utterance will either + + + align:start position:0% +when apply to an utterance will either +accept or uh if you can find a set of + + align:start position:0% +accept or uh if you can find a set of + + + align:start position:0% +accept or uh if you can find a set of +grammar rules which produces that + + align:start position:0% +grammar rules which produces that + + + align:start position:0% +grammar rules which produces that +utterance then it's a sentence and if + + align:start position:0% +utterance then it's a sentence and if + + + align:start position:0% +utterance then it's a sentence and if +you can't then it's not so in some sense + + align:start position:0% +you can't then it's not so in some sense + + + align:start position:0% +you can't then it's not so in some sense +he's as much of a behaviorist as Skinner + + align:start position:0% +he's as much of a behaviorist as Skinner + + + align:start position:0% +he's as much of a behaviorist as Skinner +was because neither of them ask under + + align:start position:0% +was because neither of them ask under + + + align:start position:0% +was because neither of them ask under +what conditions will you produce a + + align:start position:0% +what conditions will you produce a + + + align:start position:0% +what conditions will you produce a +particular + + align:start position:0% +particular + + + align:start position:0% +particular +sentence or even more important perhaps + + align:start position:0% +sentence or even more important perhaps + + + align:start position:0% +sentence or even more important perhaps +uh because a lot of what people say + + align:start position:0% +uh because a lot of what people say + + + align:start position:0% +uh because a lot of what people say +aren't + + align:start position:0% +aren't + + + align:start position:0% +aren't +sentences like the one I just finishing + + align:start position:0% +sentences like the one I just finishing + + + align:start position:0% +sentences like the one I just finishing +now that wasn't a sentence and you know + + align:start position:0% +now that wasn't a sentence and you know + + + align:start position:0% +now that wasn't a sentence and you know +exactly what it meant uh so it doesn't + + align:start position:0% +exactly what it meant uh so it doesn't + + + align:start position:0% +exactly what it meant uh so it doesn't +explain uh very much of human verbal + + align:start position:0% +explain uh very much of human verbal + + + align:start position:0% +explain uh very much of human verbal +Behavior Uh it does explain in in many + + align:start position:0% +Behavior Uh it does explain in in many + + + align:start position:0% +Behavior Uh it does explain in in many +cases uh which utterances after careful + + align:start position:0% +cases uh which utterances after careful + + + align:start position:0% +cases uh which utterances after careful +analysis you will + + align:start position:0% +analysis you will + + + align:start position:0% +analysis you will +decide is a sentence and that's a sort + + align:start position:0% +decide is a sentence and that's a sort + + + align:start position:0% +decide is a sentence and that's a sort +of behavioristic criteria not a + + align:start position:0% +of behavioristic criteria not a + + + align:start position:0% +of behavioristic criteria not a +cognitive one oh well enough denouncing + + align:start position:0% +cognitive one oh well enough denouncing + + + align:start position:0% +cognitive one oh well enough denouncing +chsky it's it's one of my hobbies + + align:start position:0% + + + + align:start position:0% + +so but it's interesting that neither + + align:start position:0% +so but it's interesting that neither + + + align:start position:0% +so but it's interesting that neither +Pavlov or Skinner discuss very much how + + align:start position:0% +Pavlov or Skinner discuss very much how + + + align:start position:0% +Pavlov or Skinner discuss very much how +does the animal decide what to + + align:start position:0% +does the animal decide what to + + + align:start position:0% +does the animal decide what to +try and obviously when you think about + + align:start position:0% +try and obviously when you think about + + + align:start position:0% +try and obviously when you think about +that for about 10 seconds you say well + + align:start position:0% +that for about 10 seconds you say well + + + align:start position:0% +that for about 10 seconds you say well +that's much more important than making a + + align:start position:0% +that's much more important than making a + + + align:start position:0% +that's much more important than making a +description from the outside of just + + align:start position:0% +description from the outside of just + + + align:start position:0% +description from the outside of just +which responses come how often to to + + align:start position:0% +which responses come how often to to + + + align:start position:0% +which responses come how often to to +which stimuli where did the responses + + align:start position:0% +which stimuli where did the responses + + + align:start position:0% +which stimuli where did the responses +themselves come + + align:start position:0% + + + + align:start position:0% + +from so then the next theory + + align:start position:0% + + + + align:start position:0% + +is well why have two levels why not have + + align:start position:0% +is well why have two levels why not have + + + align:start position:0% +is well why have two levels why not have +another level and the main model of the + + align:start position:0% +another level and the main model of the + + + align:start position:0% +another level and the main model of the +book I shouldn't say the main one + + align:start position:0% +book I shouldn't say the main one + + + align:start position:0% +book I shouldn't say the main one +because + + align:start position:0% +because + + + align:start position:0% +because +uh really the strategy in the the + + align:start position:0% +uh really the strategy in the the + + + align:start position:0% +uh really the strategy in the the +emotion machine project or the the whole + + align:start position:0% +emotion machine project or the the whole + + + align:start position:0% +emotion machine project or the the whole +idea is that uh we don't want to be like + + align:start position:0% +idea is that uh we don't want to be like + + + align:start position:0% +idea is that uh we don't want to be like +physicists and say here are the laws of + + align:start position:0% +physicists and say here are the laws of + + + align:start position:0% +physicists and say here are the laws of +thought the reason for that is that uh + + align:start position:0% +thought the reason for that is that uh + + + align:start position:0% +thought the reason for that is that uh +what a physicist does is to look for a + + align:start position:0% +what a physicist does is to look for a + + + align:start position:0% +what a physicist does is to look for a +very small number of rules in the case + + align:start position:0% +very small number of rules in the case + + + align:start position:0% +very small number of rules in the case +of the human brain you know that there + + align:start position:0% +of the human brain you know that there + + + align:start position:0% +of the human brain you know that there +are 400 different pieces of machinery + + align:start position:0% +are 400 different pieces of machinery + + + align:start position:0% +are 400 different pieces of machinery +and uh the behavior of all the different + + align:start position:0% +and uh the behavior of all the different + + + align:start position:0% +and uh the behavior of all the different +mammals are quite different in some + + align:start position:0% +mammals are quite different in some + + + align:start position:0% +mammals are quite different in some +respects all they're all similar in + + align:start position:0% +respects all they're all similar in + + + align:start position:0% +respects all they're all similar in +others and so no very simple Theory + + align:start position:0% +others and so no very simple Theory + + + align:start position:0% +others and so no very simple Theory +could explain it uh the biggest part of + + align:start position:0% +could explain it uh the biggest part of + + + align:start position:0% +could explain it uh the biggest part of +the evidence from neurology is that + + align:start position:0% +the evidence from neurology is that + + + align:start position:0% +the evidence from neurology is that +there are lots of different parts of the + + align:start position:0% +there are lots of different parts of the + + + align:start position:0% +there are lots of different parts of the +brain and if you uh injure one then the + + align:start position:0% +brain and if you uh injure one then the + + + align:start position:0% +brain and if you uh injure one then the +animal's behavior changes in various + + align:start position:0% +animal's behavior changes in various + + + align:start position:0% +animal's behavior changes in various +ways it's uh usually can still solve + + align:start position:0% +ways it's uh usually can still solve + + + align:start position:0% +ways it's uh usually can still solve +lots of problems in some Realms but not + + align:start position:0% +lots of problems in some Realms but not + + + align:start position:0% +lots of problems in some Realms but not +in others and uh + + align:start position:0% +in others and uh + + + align:start position:0% +in others and uh +and uh so it wouldn't be a matter of a + + align:start position:0% +and uh so it wouldn't be a matter of a + + + align:start position:0% +and uh so it wouldn't be a matter of a +small number of uh basic + + align:start position:0% + + + + align:start position:0% + +principles uh then the rest of the book + + align:start position:0% +principles uh then the rest of the book + + + align:start position:0% +principles uh then the rest of the book +jumps into this idea of + + align:start position:0% +jumps into this idea of + + + align:start position:0% +jumps into this idea of +asking + + align:start position:0% +asking + + + align:start position:0% +asking +uh oh I didn't realize I had that in + + align:start position:0% +uh oh I didn't realize I had that in + + + align:start position:0% +uh oh I didn't realize I had that in +that chapter I talked a lot about the uh + + align:start position:0% +that chapter I talked a lot about the uh + + + align:start position:0% +that chapter I talked a lot about the uh +duplication and diversity there + + align:start position:0% + + + + align:start position:0% + +but the chapter is called + + align:start position:0% +but the chapter is called + + + align:start position:0% +but the chapter is called +Consciousness + + align:start position:0% +Consciousness + + + align:start position:0% +Consciousness +and anybody want to describe what they + + align:start position:0% +and anybody want to describe what they + + + align:start position:0% +and anybody want to describe what they +how do you how would you describe or + + align:start position:0% +how do you how would you describe or + + + align:start position:0% +how do you how would you describe or +explain when a human action is conscious + + align:start position:0% +explain when a human action is conscious + + + align:start position:0% +explain when a human action is conscious +or not anybody want to try a + + align:start position:0% +or not anybody want to try a + + + align:start position:0% +or not anybody want to try a +description when would you say you made + + align:start position:0% +description when would you say you made + + + align:start position:0% +description when would you say you made +a conscious + + align:start position:0% +a conscious + + + align:start position:0% +a conscious +decision you predicted what you wanted + + align:start position:0% +decision you predicted what you wanted + + + align:start position:0% +decision you predicted what you wanted +to do and then did it realize that all + + align:start position:0% +to do and then did it realize that all + + + align:start position:0% +to do and then did it realize that all +those things matched the conscious that + + align:start position:0% +those things matched the conscious that + + + align:start position:0% +those things matched the conscious that +you did when you had a description of + + align:start position:0% +you did when you had a description of + + + align:start position:0% +you did when you had a description of +what you were going to do already + + align:start position:0% +what you were going to do already + + + align:start position:0% +what you were going to do already +right but it needs a little more than + + align:start position:0% +right but it needs a little more than + + + align:start position:0% +right but it needs a little more than +that you have to know that you had the + + align:start position:0% +that you have to know that you had the + + + align:start position:0% +that you have to know that you had the +description what if the description were + + align:start position:0% +description what if the description were + + + align:start position:0% +description what if the description were +in in this part of your brain and and + + align:start position:0% +in in this part of your brain and and + + + align:start position:0% +in in this part of your brain and and +the part that's well actually the part + + align:start position:0% +the part that's well actually the part + + + align:start position:0% +the part that's well actually the part +of your brain that's talking is uh in + + align:start position:0% +of your brain that's talking is uh in + + + align:start position:0% +of your brain that's talking is uh in +most people on the left side so what if + + align:start position:0% +most people on the left side so what if + + + align:start position:0% +most people on the left side so what if +the description were over here + + align:start position:0% +the description were over here + + + align:start position:0% +the description were over here +and uh you weren't able to say that you + + align:start position:0% +and uh you weren't able to say that you + + + align:start position:0% +and uh you weren't able to say that you +had + + align:start position:0% +had + + + align:start position:0% +had +one what if the description were + + align:start position:0% +one what if the description were + + + align:start position:0% +one what if the description were +actually there in some other part of the + + align:start position:0% +actually there in some other part of the + + + align:start position:0% +actually there in some other part of the +brain would that be conscious or would + + align:start position:0% +brain would that be conscious or would + + + align:start position:0% +brain would that be conscious or would +it just be a matter of your being able + + align:start position:0% +it just be a matter of your being able + + + align:start position:0% +it just be a matter of your being able +to uh describe it uh with your verbal + + align:start position:0% +to uh describe it uh with your verbal + + + align:start position:0% +to uh describe it uh with your verbal +output other words how do you know what + + align:start position:0% +output other words how do you know what + + + align:start position:0% +output other words how do you know what +you're conscious of is it just + + align:start position:0% + + + + align:start position:0% + +uh only verbal + + align:start position:0% + + + + align:start position:0% + +well of course it's not verbal uh for + + align:start position:0% +well of course it's not verbal uh for + + + align:start position:0% +well of course it's not verbal uh for +example if I'm thinking about picking up + + align:start position:0% +example if I'm thinking about picking up + + + align:start position:0% +example if I'm thinking about picking up +this coke + + align:start position:0% +this coke + + + align:start position:0% +this coke +bottle uh I'm aware + + align:start position:0% +bottle uh I'm aware + + + align:start position:0% +bottle uh I'm aware +of what would you call it a virtual in I + + align:start position:0% +of what would you call it a virtual in I + + + align:start position:0% +of what would you call it a virtual in I +have a little virtual world and I can + + align:start position:0% +have a little virtual world and I can + + + align:start position:0% +have a little virtual world and I can +feel my arm going out and uh I can feel + + align:start position:0% +feel my arm going out and uh I can feel + + + align:start position:0% +feel my arm going out and uh I can feel +that when it gets about here in touches + + align:start position:0% +that when it gets about here in touches + + + align:start position:0% +that when it gets about here in touches +it I'll get a sensation of cold and so + + align:start position:0% +it I'll get a sensation of cold and so + + + align:start position:0% +it I'll get a sensation of cold and so +forth and I presumably could do that + + align:start position:0% +forth and I presumably could do that + + + align:start position:0% +forth and I presumably could do that +without uh having had any verbal + + align:start position:0% +without uh having had any verbal + + + align:start position:0% +without uh having had any verbal +conception or of course I can't be sure + + align:start position:0% +conception or of course I can't be sure + + + align:start position:0% +conception or of course I can't be sure +that uh maybe there's a second language + + align:start position:0% +that uh maybe there's a second language + + + align:start position:0% +that uh maybe there's a second language +area that deals with + + align:start position:0% +area that deals with + + + align:start position:0% +area that deals with +semantics uh with semantic symbols that + + align:start position:0% +semantics uh with semantic symbols that + + + align:start position:0% +semantics uh with semantic symbols that +aren't words and before you speak uh + + align:start position:0% +aren't words and before you speak uh + + + align:start position:0% +aren't words and before you speak uh +that other thing is operating and if you + + align:start position:0% +that other thing is operating and if you + + + align:start position:0% +that other thing is operating and if you +don't happen to feel like talking you + + align:start position:0% +don't happen to feel like talking you + + + align:start position:0% +don't happen to feel like talking you +might never realize that you had + + align:start position:0% +might never realize that you had + + + align:start position:0% +might never realize that you had +something + + align:start position:0% +something + + + align:start position:0% +something +just below the surface of of a verbal + + align:start position:0% +just below the surface of of a verbal + + + align:start position:0% +just below the surface of of a verbal +expression for I was looking at Japanese + + align:start position:0% +expression for I was looking at Japanese + + + align:start position:0% +expression for I was looking at Japanese +characters and they they feel completely + + align:start position:0% +characters and they they feel completely + + + align:start position:0% +characters and they they feel completely +different uh from English characters + + align:start position:0% +different uh from English characters + + + align:start position:0% +different uh from English characters +because uh the words go straight up u in + + align:start position:0% +because uh the words go straight up u in + + + align:start position:0% +because uh the words go straight up u in +columns did you mean or uh straight up + + align:start position:0% +columns did you mean or uh straight up + + + align:start position:0% +columns did you mean or uh straight up +in terms of you know the features um of + + align:start position:0% +in terms of you know the features um of + + + align:start position:0% +in terms of you know the features um of +of the letters the ink I'm not conscious + + align:start position:0% +of the letters the ink I'm not conscious + + + align:start position:0% +of the letters the ink I'm not conscious +all of that I'm not conscious of the + + align:start position:0% +all of that I'm not conscious of the + + + align:start position:0% +all of that I'm not conscious of the +lines that are very particular in + + align:start position:0% +lines that are very particular in + + + align:start position:0% +lines that are very particular in +Japanese characters um but uh when I + + align:start position:0% +Japanese characters um but uh when I + + + align:start position:0% +Japanese characters um but uh when I +look at English words I I I'm instantly + + align:start position:0% +look at English words I I I'm instantly + + + align:start position:0% +look at English words I I I'm instantly +aware of the meaning of it instead of + + align:start position:0% +aware of the meaning of it instead of + + + align:start position:0% +aware of the meaning of it instead of +looking at the low level descriptions + + align:start position:0% +looking at the low level descriptions + + + align:start position:0% +looking at the low level descriptions +that are being buil that are being built + + align:start position:0% +that are being buil that are being built + + + align:start position:0% +that are being buil that are being built +up I think sometimes you can have two + + align:start position:0% +up I think sometimes you can have two + + + align:start position:0% +up I think sometimes you can have two +Japanese characters that have the same + + align:start position:0% +Japanese characters that have the same + + + align:start position:0% +Japanese characters that have the same +pronunciation can't + + align:start position:0% +pronunciation can't + + + align:start position:0% +pronunciation can't +you yeah + + align:start position:0% +you yeah + + + align:start position:0% +you yeah +because I was once uh + + align:start position:0% +because I was once uh + + + align:start position:0% +because I was once uh +watching two people talk and in Japan + + align:start position:0% +watching two people talk and in Japan + + + align:start position:0% +watching two people talk and in Japan +and the first one said something the + + align:start position:0% +and the first one said something the + + + align:start position:0% +and the first one said something the +others said didn't understand the first + + align:start position:0% +others said didn't understand the first + + + align:start position:0% +others said didn't understand the first +one as well I mean this and he made a + + align:start position:0% +one as well I mean this and he made a + + + align:start position:0% +one as well I mean this and he made a +few brush + + align:start position:0% +few brush + + + align:start position:0% +few brush +Strokes because there wasn't + + align:start position:0% +Strokes because there wasn't + + + align:start position:0% +Strokes because there wasn't +any pronouncing it more clearly wouldn't + + align:start position:0% +any pronouncing it more clearly wouldn't + + + align:start position:0% +any pronouncing it more clearly wouldn't +help what I'm try to say is that uh when + + align:start position:0% +help what I'm try to say is that uh when + + + align:start position:0% +help what I'm try to say is that uh when +we learning a language or learning + + align:start position:0% +we learning a language or learning + + + align:start position:0% +we learning a language or learning +symbols then we might be conscious of + + align:start position:0% +symbols then we might be conscious of + + + align:start position:0% +symbols then we might be conscious of +the processings that you know we are + + align:start position:0% +the processings that you know we are + + + align:start position:0% +the processings that you know we are +trying to learn from yes or the + + align:start position:0% +trying to learn from yes or the + + + align:start position:0% +trying to learn from yes or the +representations that we building but + + align:start position:0% +representations that we building but + + + align:start position:0% +representations that we building but +once we've done + + align:start position:0% +once we've done + + + align:start position:0% +once we've done +that uh then maybe we have lost the + + align:start position:0% +that uh then maybe we have lost the + + + align:start position:0% +that uh then maybe we have lost the +intermediate descriptions that build + + align:start position:0% +intermediate descriptions that build + + + align:start position:0% +intermediate descriptions that build +things on exactly it's like uh the + + align:start position:0% +things on exactly it's like uh the + + + align:start position:0% +things on exactly it's like uh the +difference between a highlevel program + + align:start position:0% +difference between a highlevel program + + + align:start position:0% +difference between a highlevel program +and a compiled + + align:start position:0% +and a compiled + + + align:start position:0% +and a compiled +one presumably when you're an + + align:start position:0% +one presumably when you're an + + + align:start position:0% +one presumably when you're an +expert uh when you're a beginner this + + align:start position:0% +expert uh when you're a beginner this + + + align:start position:0% +expert uh when you're a beginner this +teacher tells you all these rules or or + + align:start position:0% +teacher tells you all these rules or or + + + align:start position:0% +teacher tells you all these rules or or +you learn them somehow or look them up + + align:start position:0% +you learn them somehow or look them up + + + align:start position:0% +you learn them somehow or look them up +uh I actually remember + + align:start position:0% +uh I actually remember + + + align:start position:0% +uh I actually remember +uh when my father uh explained how chess + + align:start position:0% +uh when my father uh explained how chess + + + align:start position:0% +uh when my father uh explained how chess +worked and I couldn't believe anybody + + align:start position:0% +worked and I couldn't believe anybody + + + align:start position:0% +worked and I couldn't believe anybody +could do that in real time because he + + align:start position:0% +could do that in real time because he + + + align:start position:0% +could do that in real time because he +would explain that well the night can + + align:start position:0% +would explain that well the night can + + + align:start position:0% +would explain that well the night can +move two two forward and one this way or + + align:start position:0% +move two two forward and one this way or + + + align:start position:0% +move two two forward and one this way or +two this way or one this way and and + + align:start position:0% +two this way or one this way and and + + + align:start position:0% +two this way or one this way and and +there are eight different ways + + align:start position:0% + + + + align:start position:0% + +and uh after a few games uh those rules + + align:start position:0% +and uh after a few games uh those rules + + + align:start position:0% +and uh after a few games uh those rules +have disappeared and you're you've + + align:start position:0% +have disappeared and you're you've + + + align:start position:0% +have disappeared and you're you've +compiled it uh um each person must have + + align:start position:0% +compiled it uh um each person must have + + + align:start position:0% +compiled it uh um each person must have +a different uh new compiled + + align:start position:0% +a different uh new compiled + + + align:start position:0% +a different uh new compiled +representation but mine is that the + + align:start position:0% +representation but mine is that the + + + align:start position:0% +representation but mine is that the +Knight has this uh jaggedy circle around + + align:start position:0% +Knight has this uh jaggedy circle around + + + align:start position:0% +Knight has this uh jaggedy circle around +it and uh it's perfectly obvious uh if + + align:start position:0% +it and uh it's perfectly obvious uh if + + + align:start position:0% +it and uh it's perfectly obvious uh if +the night is on this black Square then + + align:start position:0% +the night is on this black Square then + + + align:start position:0% +the night is on this black Square then +these eight uh white squares uh just + + align:start position:0% +these eight uh white squares uh just + + + align:start position:0% +these eight uh white squares uh just +turn pink or something you can think of + + align:start position:0% +turn pink or something you can think of + + + align:start position:0% +turn pink or something you can think of +it as colors or something but they just + + align:start position:0% +it as colors or something but they just + + + align:start position:0% +it as colors or something but they just +jump out and wherever the night is it + + align:start position:0% +jump out and wherever the night is it + + + align:start position:0% +jump out and wherever the night is it +has this Aura around it and uh happens + + align:start position:0% +has this Aura around it and uh happens + + + align:start position:0% +has this Aura around it and uh happens +without thinking uh if you had to think + + align:start position:0% +without thinking uh if you had to think + + + align:start position:0% +without thinking uh if you had to think +you would never have time to make your + + align:start position:0% +you would never have time to make your + + + align:start position:0% +you would never have time to make your +next + + align:start position:0% + + + + align:start position:0% + +move well + + align:start position:0% +move well + + + align:start position:0% +move well +uh as the chapter says at the beginning + + align:start position:0% +uh as the chapter says at the beginning + + + align:start position:0% +uh as the chapter says at the beginning +there's a lot of uh great many very + + align:start position:0% +there's a lot of uh great many very + + + align:start position:0% +there's a lot of uh great many very +smart + + align:start position:0% +smart + + + align:start position:0% +smart +people uh feel that there's a big + + align:start position:0% +people uh feel that there's a big + + + align:start position:0% +people uh feel that there's a big +mystery about Consciousness could could + + align:start position:0% +mystery about Consciousness could could + + + align:start position:0% +mystery about Consciousness could could +you have a zombie machine as it's been + + align:start position:0% +you have a zombie machine as it's been + + + align:start position:0% +you have a zombie machine as it's been +called which does exactly could you have + + align:start position:0% +called which does exactly could you have + + + align:start position:0% +called which does exactly could you have +a brain uh which is just like your brain + + align:start position:0% +a brain uh which is just like your brain + + + align:start position:0% +a brain uh which is just like your brain +and it does everything uh you do it's + + align:start position:0% +and it does everything uh you do it's + + + align:start position:0% +and it does everything uh you do it's +absolutely identical to you except that + + align:start position:0% +absolutely identical to you except that + + + align:start position:0% +absolutely identical to you except that +it does it's not conscious of what it's + + align:start position:0% +it does it's not conscious of what it's + + + align:start position:0% +it does it's not conscious of what it's +doing and people like uh David Chalmer + + align:start position:0% +doing and people like uh David Chalmer + + + align:start position:0% +doing and people like uh David Chalmer +who's a well-known philosopher of + + align:start position:0% +who's a well-known philosopher of + + + align:start position:0% +who's a well-known philosopher of +Consciousness says well it's logically + + align:start position:0% +Consciousness says well it's logically + + + align:start position:0% +Consciousness says well it's logically +perfectly possible that they could be + + align:start position:0% +perfectly possible that they could be + + + align:start position:0% +perfectly possible that they could be +another person just like you with a + + align:start position:0% +another person just like you with a + + + align:start position:0% +another person just like you with a +brain just like + + align:start position:0% +brain just like + + + align:start position:0% +brain just like +yours uh except that it doesn't have any + + align:start position:0% +yours uh except that it doesn't have any + + + align:start position:0% +yours uh except that it doesn't have any +conscious + + align:start position:0% +conscious + + + align:start position:0% +conscious +experience and + + align:start position:0% +experience and + + + align:start position:0% +experience and +uh I think I might have mentioned that + + align:start position:0% +uh I think I might have mentioned that + + + align:start position:0% +uh I think I might have mentioned that +somewhere in this book when he says + + align:start position:0% +somewhere in this book when he says + + + align:start position:0% +somewhere in this book when he says +logically + + align:start position:0% +logically + + + align:start position:0% +logically +possible I think he's confused what do + + align:start position:0% +possible I think he's confused what do + + + align:start position:0% +possible I think he's confused what do +you mean log uh to say that + + align:start position:0% +you mean log uh to say that + + + align:start position:0% +you mean log uh to say that +something follows logically from another + + align:start position:0% +something follows logically from another + + + align:start position:0% +something follows logically from another +thing one statement follows logically + + align:start position:0% +thing one statement follows logically + + + align:start position:0% +thing one statement follows logically +from another statement doesn't mean + + align:start position:0% +from another statement doesn't mean + + + align:start position:0% +from another statement doesn't mean +anything by itself because the word + + align:start position:0% +anything by itself because the word + + + align:start position:0% +anything by itself because the word +logic refers generally to a set of + + align:start position:0% +logic refers generally to a set of + + + align:start position:0% +logic refers generally to a set of +axioms a set of assumptions of which the + + align:start position:0% +axioms a set of assumptions of which the + + + align:start position:0% +axioms a set of assumptions of which the +average person probably has 60 million + + align:start position:0% +average person probably has 60 million + + + align:start position:0% +average person probably has 60 million +or something like that that's that's + + align:start position:0% +or something like that that's that's + + + align:start position:0% +or something like that that's that's +my one of one of the estimates I like + + align:start position:0% +my one of one of the estimates I like + + + align:start position:0% +my one of one of the estimates I like +that a person knows the order of 50 or + + align:start position:0% +that a person knows the order of 50 or + + + align:start position:0% +that a person knows the order of 50 or +100 million fragments of information so + + align:start position:0% +100 million fragments of information so + + + align:start position:0% +100 million fragments of information so +when you say something is logic Ally + + align:start position:0% +when you say something is logic Ally + + + align:start position:0% +when you say something is logic Ally +possible that means that given these 100 + + align:start position:0% +possible that means that given these 100 + + + align:start position:0% +possible that means that given these 100 +million uh axioms and + + align:start position:0% +million uh axioms and + + + align:start position:0% +million uh axioms and +given the rules by which you can derive + + align:start position:0% +given the rules by which you can derive + + + align:start position:0% +given the rules by which you can derive +a new sentence from one or two or more + + align:start position:0% +a new sentence from one or two or more + + + align:start position:0% +a new sentence from one or two or more +uh already established axioms or axioms + + align:start position:0% +uh already established axioms or axioms + + + align:start position:0% +uh already established axioms or axioms +or already established conclusions + + align:start position:0% +or already established conclusions + + + align:start position:0% +or already established conclusions +that's what logically possible + + align:start position:0% +that's what logically possible + + + align:start position:0% +that's what logically possible +means and chers is saying it's logically + + align:start position:0% +means and chers is saying it's logically + + + align:start position:0% +means and chers is saying it's logically +possible in the sense that uh he thinks + + align:start position:0% +possible in the sense that uh he thinks + + + align:start position:0% +possible in the sense that uh he thinks +he can imagine + + align:start position:0% +he can imagine + + + align:start position:0% +he can imagine +these two machines one of which is + + align:start position:0% +these two machines one of which is + + + align:start position:0% +these two machines one of which is +conscious and one isn't but they're + + align:start position:0% +conscious and one isn't but they're + + + align:start position:0% +conscious and one isn't but they're +otherwise the + + align:start position:0% +otherwise the + + + align:start position:0% +otherwise the +same there's nothing logical about it I + + align:start position:0% +same there's nothing logical about it I + + + align:start position:0% +same there's nothing logical about it I +don't believe he can imagine either of + + align:start position:0% +don't believe he can imagine either of + + + align:start position:0% +don't believe he can imagine either of +those + + align:start position:0% +those + + + align:start position:0% +those +machines he can only make sentences + + align:start position:0% +machines he can only make sentences + + + align:start position:0% +machines he can only make sentences +about them and publish them and convince + + align:start position:0% +about them and publish them and convince + + + align:start position:0% +about them and publish them and convince +other people that they make sense how do + + align:start position:0% +other people that they make sense how do + + + align:start position:0% +other people that they make sense how do +you imagine a machine that's the same as + + align:start position:0% +you imagine a machine that's the same as + + + align:start position:0% +you imagine a machine that's the same as +you but it's not + + align:start position:0% +you but it's not + + + align:start position:0% +you but it's not +conscious all you can do is Imagine that + + align:start position:0% +conscious all you can do is Imagine that + + + align:start position:0% +conscious all you can do is Imagine that +somebody would uh would understand that + + align:start position:0% +somebody would uh would understand that + + + align:start position:0% +somebody would uh would understand that +sentence in some way + + align:start position:0% +sentence in some way + + + align:start position:0% +sentence in some way +yeah could we could we build like a very + + align:start position:0% +yeah could we could we build like a very + + + align:start position:0% +yeah could we could we build like a very +simple block world uh with a character + + align:start position:0% +simple block world uh with a character + + + align:start position:0% +simple block world uh with a character +there doing something that people would + + align:start position:0% +there doing something that people would + + + align:start position:0% +there doing something that people would +agree that it's conscious of + + align:start position:0% +agree that it's conscious of + + + align:start position:0% +agree that it's conscious of +itself well they'd have to Define + + align:start position:0% +itself well they'd have to Define + + + align:start position:0% +itself well they'd have to Define +conscious well I mean that agree that + + align:start position:0% +conscious well I mean that agree that + + + align:start position:0% +conscious well I mean that agree that +you know if I think that this guy's + + align:start position:0% +you know if I think that this guy's + + + align:start position:0% +you know if I think that this guy's +conscious then that guy's conscious mhm + + align:start position:0% +conscious then that guy's conscious mhm + + + align:start position:0% +conscious then that guy's conscious mhm +I'm not sure what you're saying you're + + align:start position:0% +I'm not sure what you're saying you're + + + align:start position:0% +I'm not sure what you're saying you're +saying well let's assume that he's + + align:start position:0% +saying well let's assume that he's + + + align:start position:0% +saying well let's assume that he's +conscious and he and the and they behave + + align:start position:0% +conscious and he and the and they behave + + + align:start position:0% +conscious and he and the and they behave +the same they behave the same they speak + + align:start position:0% +the same they behave the same they speak + + + align:start position:0% +the same they behave the same they speak +the same language all right but what is + + align:start position:0% +the same language all right but what is + + + align:start position:0% +the same language all right but what is +it you're + + align:start position:0% +it you're + + + align:start position:0% +it you're +imagining uh I'm I'm imagining uh a + + align:start position:0% +imagining uh I'm I'm imagining uh a + + + align:start position:0% +imagining uh I'm I'm imagining uh a +blocks world uh system which has uh a + + align:start position:0% +blocks world uh system which has uh a + + + align:start position:0% +blocks world uh system which has uh a +few guys in it uh who are building + + align:start position:0% +few guys in it uh who are building + + + align:start position:0% +few guys in it uh who are building +something or doing something M and + + align:start position:0% +something or doing something M and + + + align:start position:0% +something or doing something M and +uh and it has a lot of is that let's say + + align:start position:0% +uh and it has a lot of is that let's say + + + align:start position:0% +uh and it has a lot of is that let's say +you were talking about and would would + + align:start position:0% +you were talking about and would would + + + align:start position:0% +you were talking about and would would +people agree that those characters are + + align:start position:0% +people agree that those characters are + + + align:start position:0% +people agree that those characters are +conscious what's the test like what's + + align:start position:0% +conscious what's the test like what's + + + align:start position:0% +conscious what's the test like what's +the how would they what would it mean + + align:start position:0% +the how would they what would it mean + + + align:start position:0% +the how would they what would it mean +what matter would it be if they agreed + + align:start position:0% +what matter would it be if they agreed + + + align:start position:0% +what matter would it be if they agreed +what would they + + align:start position:0% +what would they + + + align:start position:0% +what would they +mean um well if the machines are the + + align:start position:0% +mean um well if the machines are the + + + align:start position:0% +mean um well if the machines are the +same and you're saying well I can + + align:start position:0% +same and you're saying well I can + + + align:start position:0% +same and you're saying well I can +imagine that this machine isn't + + align:start position:0% +imagine that this machine isn't + + + align:start position:0% +imagine that this machine isn't +conscious and this one is I don't see + + align:start position:0% +conscious and this one is I don't see + + + align:start position:0% +conscious and this one is I don't see +what you're imagining well finding the + + align:start position:0% +what you're imagining well finding the + + + align:start position:0% +what you're imagining well finding the +word Consciousness but I don't even know + + align:start position:0% +word Consciousness but I don't even know + + + align:start position:0% +word Consciousness but I don't even know +what it means M then how can you imagine + + align:start position:0% +what it means M then how can you imagine + + + align:start position:0% +what it means M then how can you imagine +what it would be from this one not to be + + align:start position:0% +what it would be from this one not to be + + + align:start position:0% +what it would be from this one not to be +conscious if you have no idea what it + + align:start position:0% +conscious if you have no idea what it + + + align:start position:0% +conscious if you have no idea what it +means yeah but but I'm saying those + + align:start position:0% +means yeah but but I'm saying those + + + align:start position:0% +means yeah but but I'm saying those +people aree those people who who are + + align:start position:0% +people aree those people who who are + + + align:start position:0% +people aree those people who who are +trying to + + align:start position:0% + + + + align:start position:0% + +find well I'm just saying in my opinion + + align:start position:0% +find well I'm just saying in my opinion + + + align:start position:0% +find well I'm just saying in my opinion +Chalmer doesn't have any idea of what + + align:start position:0% +Chalmer doesn't have any idea of what + + + align:start position:0% +Chalmer doesn't have any idea of what +that would + + align:start position:0% +that would + + + align:start position:0% +that would +mean and so he says it's logically + + align:start position:0% +mean and so he says it's logically + + + align:start position:0% +mean and so he says it's logically +possible meaning I can't imagine anyone + + align:start position:0% +possible meaning I can't imagine anyone + + + align:start position:0% +possible meaning I can't imagine anyone +objecting to this or something like that + + align:start position:0% +objecting to this or something like that + + + align:start position:0% +objecting to this or something like that +it's he's not making a statement about + + align:start position:0% +it's he's not making a statement about + + + align:start position:0% +it's he's not making a statement about +Consciousness because he's saying that's + + align:start position:0% +Consciousness because he's saying that's + + + align:start position:0% +Consciousness because he's saying that's +a mystery I don't know what it is I + + align:start position:0% +a mystery I don't know what it is I + + + align:start position:0% +a mystery I don't know what it is I +don't think it's describable in physical + + align:start position:0% +don't think it's describable in physical + + + align:start position:0% +don't think it's describable in physical +terms he has all these negative things + + align:start position:0% +terms he has all these negative things + + + align:start position:0% +terms he has all these negative things +he says this is a very hard problem + + align:start position:0% +he says this is a very hard problem + + + align:start position:0% +he says this is a very hard problem +which probably no one will ever + + align:start position:0% +which probably no one will ever + + + align:start position:0% +which probably no one will ever +solve but I don't think when he says + + align:start position:0% +solve but I don't think when he says + + + align:start position:0% +solve but I don't think when he says +it's logically possible that there's + + align:start position:0% +it's logically possible that there's + + + align:start position:0% +it's logically possible that there's +this + + align:start position:0% +this + + + align:start position:0% +this +difference as uh pen Gillette would say + + align:start position:0% +difference as uh pen Gillette would say + + + align:start position:0% +difference as uh pen Gillette would say +I I think that's just word + + align:start position:0% +I I think that's just word + + + align:start position:0% +I I think that's just word +salad that you look at that and say + + align:start position:0% +salad that you look at that and say + + + align:start position:0% +salad that you look at that and say +well Chalmer is saying that he sees some + + align:start position:0% +well Chalmer is saying that he sees some + + + align:start position:0% +well Chalmer is saying that he sees some +meaning in this + + align:start position:0% +meaning in this + + + align:start position:0% +meaning in this +assertion but I don't see any reason to + + align:start position:0% +assertion but I don't see any reason to + + + align:start position:0% +assertion but I don't see any reason to +believe + + align:start position:0% +believe + + + align:start position:0% +believe +him U maybe because I don't see him as + + align:start position:0% +him U maybe because I don't see him as + + + align:start position:0% +him U maybe because I don't see him as +ever having any other good ideas about + + align:start position:0% +ever having any other good ideas about + + + align:start position:0% +ever having any other good ideas about +psychology well that's + + align:start position:0% +psychology well that's + + + align:start position:0% +psychology well that's +mean maybe he has + + align:start position:0% +mean maybe he has + + + align:start position:0% +mean maybe he has +had but in fact what I + + align:start position:0% + + + + align:start position:0% + +the trick in this chapter I think this + + align:start position:0% +the trick in this chapter I think this + + + align:start position:0% +the trick in this chapter I think this +is sort of original maybe you've seen + + align:start position:0% +is sort of original maybe you've seen + + + align:start position:0% +is sort of original maybe you've seen +something like it but uh what I try to + + align:start position:0% +something like it but uh what I try to + + + align:start position:0% +something like it but uh what I try to +do is be a little more + + align:start position:0% +do is be a little more + + + align:start position:0% +do is be a little more +behavioristic and + + align:start position:0% +behavioristic and + + + align:start position:0% +behavioristic and +say uh what's going on when a person + + align:start position:0% +say uh what's going on when a person + + + align:start position:0% +say uh what's going on when a person +says + + align:start position:0% +says + + + align:start position:0% +says +uh I consciously decided to uh pick up + + align:start position:0% +uh I consciously decided to uh pick up + + + align:start position:0% +uh I consciously decided to uh pick up +that bottle of + + align:start position:0% +that bottle of + + + align:start position:0% +that bottle of +coke uh something like that what do what + + align:start position:0% +coke uh something like that what do what + + + align:start position:0% +coke uh something like that what do what +do you think is happening in a person's + + align:start position:0% +do you think is happening in a person's + + + align:start position:0% +do you think is happening in a person's +mind when they use the word conscious + + align:start position:0% +mind when they use the word conscious + + + align:start position:0% +mind when they use the word conscious +and the first chap part of the chapter + + align:start position:0% +and the first chap part of the chapter + + + align:start position:0% +and the first chap part of the chapter +you remember about Joan crossing the + + align:start position:0% +you remember about Joan crossing the + + + align:start position:0% +you remember about Joan crossing the +street describes about uh 20 or 30 + + align:start position:0% +street describes about uh 20 or 30 + + + align:start position:0% +street describes about uh 20 or 30 +different kinds of things that must have + + align:start position:0% +different kinds of things that must have + + + align:start position:0% +different kinds of things that must have +been going on in her mind uh when when + + align:start position:0% +been going on in her mind uh when when + + + align:start position:0% +been going on in her mind uh when when +she was making that decision and I left + + align:start position:0% +she was making that decision and I left + + + align:start position:0% +she was making that decision and I left +it to the reader to say well I think + + align:start position:0% +it to the reader to say well I think + + + align:start position:0% +it to the reader to say well I think +this one where she's thinking about her + + align:start position:0% +this one where she's thinking about her + + + align:start position:0% +this one where she's thinking about her +recent thoughts as conscious or or not + + align:start position:0% +recent thoughts as conscious or or not + + + align:start position:0% +recent thoughts as conscious or or not +and so forth so I didn't say when I + + align:start position:0% +and so forth so I didn't say when I + + + align:start position:0% +and so forth so I didn't say when I +listed those 30 things mental activities + + align:start position:0% +listed those 30 things mental activities + + + align:start position:0% +listed those 30 things mental activities +that she was in I didn't + + align:start position:0% +that she was in I didn't + + + align:start position:0% +that she was in I didn't +uh actually in the first draft I tried + + align:start position:0% +uh actually in the first draft I tried + + + align:start position:0% +uh actually in the first draft I tried +to make a judgment about which ones the + + align:start position:0% +to make a judgment about which ones the + + + align:start position:0% +to make a judgment about which ones the +average person would call conscious and + + align:start position:0% +average person would call conscious and + + + align:start position:0% +average person would call conscious and +then I gave up but uh but then I thought + + align:start position:0% +then I gave up but uh but then I thought + + + align:start position:0% +then I gave up but uh but then I thought +about it a lot more and so in this + + align:start position:0% +about it a lot more and so in this + + + align:start position:0% +about it a lot more and so in this +section I was saying well + + align:start position:0% +section I was saying well + + + align:start position:0% +section I was saying well +when + + align:start position:0% +when + + + align:start position:0% +when +somebody says that uh they did something + + align:start position:0% +somebody says that uh they did something + + + align:start position:0% +somebody says that uh they did something +consciously uh what could they be saying + + align:start position:0% +consciously uh what could they be saying + + + align:start position:0% +consciously uh what could they be saying +and after a while I decided + + align:start position:0% +and after a while I decided + + + align:start position:0% +and after a while I decided +that it uh very likely uses these four + + align:start position:0% +that it uh very likely uses these four + + + align:start position:0% +that it uh very likely uses these four +properties which are sort of + + align:start position:0% +properties which are sort of + + + align:start position:0% +properties which are sort of +computational ones so one thing is when + + align:start position:0% +computational ones so one thing is when + + + align:start position:0% +computational ones so one thing is when +you talk about conscious uh one feature + + align:start position:0% +you talk about conscious uh one feature + + + align:start position:0% +you talk about conscious uh one feature +is that you're talking about yourself + + align:start position:0% +is that you're talking about yourself + + + align:start position:0% +is that you're talking about yourself +probably + + align:start position:0% +probably + + + align:start position:0% +probably +explicitly you don't say a conscious + + align:start position:0% +explicitly you don't say a conscious + + + align:start position:0% +explicitly you don't say a conscious +decision was made you say I made this + + align:start position:0% +decision was made you say I made this + + + align:start position:0% +decision was made you say I made this +decision consciously what do you mean by + + align:start position:0% +decision consciously what do you mean by + + + align:start position:0% +decision consciously what do you mean by +I and I doesn't mean you I means or me I + + align:start position:0% +I and I doesn't mean you I means or me I + + + align:start position:0% +I and I doesn't mean you I means or me I +means uh the current process is using a + + align:start position:0% +means uh the current process is using a + + + align:start position:0% +means uh the current process is using a +model of + + align:start position:0% +model of + + + align:start position:0% +model of +myself I'm a big machine somewhere in + + align:start position:0% +myself I'm a big machine somewhere in + + + align:start position:0% +myself I'm a big machine somewhere in +this machine is something that it often + + align:start position:0% +this machine is something that it often + + + align:start position:0% +this machine is something that it often +uses to make predictions of what uh what + + align:start position:0% +uses to make predictions of what uh what + + + align:start position:0% +uses to make predictions of what uh what +the body of this machine will do or what + + align:start position:0% +the body of this machine will do or what + + + align:start position:0% +the body of this machine will do or what +the mouth of this words the mouth of + + align:start position:0% +the mouth of this words the mouth of + + + align:start position:0% +the mouth of this words the mouth of +this machine will speak or something and + + align:start position:0% +this machine will speak or something and + + + align:start position:0% +this machine will speak or something and +so the word I means that you're thinking + + align:start position:0% +so the word I means that you're thinking + + + align:start position:0% +so the word I means that you're thinking +about some representation or uh theory + + align:start position:0% +about some representation or uh theory + + + align:start position:0% +about some representation or uh theory +about what's inside your head assuming + + align:start position:0% +about what's inside your head assuming + + + align:start position:0% +about what's inside your head assuming +that uh like most westerners you think + + align:start position:0% +that uh like most westerners you think + + + align:start position:0% +that uh like most westerners you think +your mind is in your head I've been told + + align:start position:0% +your mind is in your head I've been told + + + align:start position:0% +your mind is in your head I've been told +that uh in some other cultures people + + align:start position:0% +that uh in some other cultures people + + + align:start position:0% +that uh in some other cultures people +think the mind is in your chest or your + + align:start position:0% +think the mind is in your chest or your + + + align:start position:0% +think the mind is in your chest or your +belly but uh I don't believe them + + align:start position:0% +belly but uh I don't believe them + + + align:start position:0% +belly but uh I don't believe them +exuse me yeah we have very simplistic uh + + align:start position:0% +exuse me yeah we have very simplistic uh + + + align:start position:0% +exuse me yeah we have very simplistic uh +descriptions of + + align:start position:0% +descriptions of + + + align:start position:0% +descriptions of +self among your descriptions of self are + + align:start position:0% +self among your descriptions of self are + + + align:start position:0% +self among your descriptions of self are +some simplistic ones is that what you're + + align:start position:0% +some simplistic ones is that what you're + + + align:start position:0% +some simplistic ones is that what you're +saying I'm saying most people have + + align:start position:0% +saying I'm saying most people have + + + align:start position:0% +saying I'm saying most people have +simple descriptions of the self + + align:start position:0% +simple descriptions of the self + + + align:start position:0% +simple descriptions of the self +otherwise they would find it very hard + + align:start position:0% +otherwise they would find it very hard + + + align:start position:0% +otherwise they would find it very hard +to say something like I did well no + + align:start position:0% +to say something like I did well no + + + align:start position:0% +to say something like I did well no +they're when they say I they're + + align:start position:0% +they're when they say I they're + + + align:start position:0% +they're when they say I they're +using if you had if you understood your + + align:start position:0% +using if you had if you understood your + + + align:start position:0% +using if you had if you understood your +conflix then you would be like oh it + + align:start position:0% +conflix then you would be like oh it + + + align:start position:0% +conflix then you would be like oh it +doesn't mean anything this part of my + + align:start position:0% +doesn't mean anything this part of my + + + align:start position:0% +doesn't mean anything this part of my +brain said this and this part of my + + align:start position:0% +brain said this and this part of my + + + align:start position:0% +brain said this and this part of my +brain said this and this hand yeah but + + align:start position:0% +brain said this and this hand yeah but + + + align:start position:0% +brain said this and this hand yeah but +the Talking part of your brain is using + + align:start position:0% +the Talking part of your brain is using + + + align:start position:0% +the Talking part of your brain is using +this word I and like any a matter ofing + + align:start position:0% +this word I and like any a matter ofing + + + align:start position:0% +this word I and like any a matter ofing +I mean you could P yourself to + + align:start position:0% +I mean you could P yourself to + + + align:start position:0% +I mean you could P yourself to +completely make the word I not mean + + align:start position:0% +completely make the word I not mean + + + align:start position:0% +completely make the word I not mean +anything well Freud says my SEC super + + align:start position:0% +anything well Freud says my SEC super + + + align:start position:0% +anything well Freud says my SEC super +ego does this and my ID does this and my + + align:start position:0% +ego does this and my ID does this and my + + + align:start position:0% +ego does this and my ID does this and my +ego does this so yes you can train + + align:start position:0% +ego does this so yes you can train + + + align:start position:0% +ego does this so yes you can train +yourself to regard yourself is made of + + align:start position:0% +yourself to regard yourself is made of + + + align:start position:0% +yourself to regard yourself is made of +three parts and most people don't but + + align:start position:0% +three parts and most people don't but + + + align:start position:0% +three parts and most people don't but +even if you don't you still may have 16 + + align:start position:0% +even if you don't you still may have 16 + + + align:start position:0% +even if you don't you still may have 16 +models and just like the word chair uh + + align:start position:0% +models and just like the word chair uh + + + align:start position:0% +models and just like the word chair uh +you use it as though it were you don't + + align:start position:0% +you use it as though it were you don't + + + align:start position:0% +you use it as though it were you don't +disambiguate it uh because a at the + + align:start position:0% +disambiguate it uh because a at the + + + align:start position:0% +disambiguate it uh because a at the +moment you're not you don't have a + + align:start position:0% +moment you're not you don't have a + + + align:start position:0% +moment you're not you don't have a +representation of yourself as a lot of + + align:start position:0% +representation of yourself as a lot of + + + align:start position:0% +representation of yourself as a lot of +subs or as a chair uh you might have a + + align:start position:0% +subs or as a chair uh you might have a + + + align:start position:0% +subs or as a chair uh you might have a +representation as something that you + + align:start position:0% +representation as something that you + + + align:start position:0% +representation as something that you +could sit on and you don't say uh it's a + + align:start position:0% +could sit on and you don't say uh it's a + + + align:start position:0% +could sit on and you don't say uh it's a +chair like this or it's a bamboo chair + + align:start position:0% +chair like this or it's a bamboo chair + + + align:start position:0% +chair like this or it's a bamboo chair +or + + align:start position:0% +or + + + align:start position:0% +or +um or a five-legged office chair and so + + align:start position:0% +um or a five-legged office chair and so + + + align:start position:0% +um or a five-legged office chair and so +forth even though every one of you + + align:start position:0% +forth even though every one of you + + + align:start position:0% +forth even though every one of you +probably has 50 or 60 rather different + + align:start position:0% +probably has 50 or 60 rather different + + + align:start position:0% +probably has 50 or 60 rather different +objects that you'd recognize as a chair + + align:start position:0% +objects that you'd recognize as a chair + + + align:start position:0% +objects that you'd recognize as a chair +that doesn't bother you when say I'm + + align:start position:0% +that doesn't bother you when say I'm + + + align:start position:0% +that doesn't bother you when say I'm +looking for something to a chair to sit + + align:start position:0% +looking for something to a chair to sit + + + align:start position:0% +looking for something to a chair to sit +on there's a dollhouse chair which you + + align:start position:0% +on there's a dollhouse chair which you + + + align:start position:0% +on there's a dollhouse chair which you +can't sit on but it's still a chair + + align:start position:0% +can't sit on but it's still a chair + + + align:start position:0% +can't sit on but it's still a chair +right I think in society Society of Mind + + align:start position:0% +right I think in society Society of Mind + + + align:start position:0% +right I think in society Society of Mind +I don't know if I had it in this book + + align:start position:0% +I don't know if I had it in this book + + + align:start position:0% +I don't know if I had it in this book +there's a picture of a broken chair + + align:start position:0% +there's a picture of a broken chair + + + align:start position:0% +there's a picture of a broken chair +which which if you sat on + + align:start position:0% + + + + align:start position:0% + +would you would break your hip or + + align:start position:0% +would you would break your hip or + + + align:start position:0% +would you would break your hip or +something so when you use conscious I + + align:start position:0% +something so when you use conscious I + + + align:start position:0% +something so when you use conscious I +think one thing that you do is uh you're + + align:start position:0% +think one thing that you do is uh you're + + + align:start position:0% +think one thing that you do is uh you're +using some representation of yourself or + + align:start position:0% +using some representation of yourself or + + + align:start position:0% +using some representation of yourself or +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +several another thing I think although + + align:start position:0% +several another thing I think although + + + align:start position:0% +several another thing I think although +this + + align:start position:0% +this + + + align:start position:0% +this +is that doesn't seem quite in fact the + + align:start position:0% +is that doesn't seem quite in fact the + + + align:start position:0% +is that doesn't seem quite in fact the +next two aren't aren't quite so + + align:start position:0% +next two aren't aren't quite so + + + align:start position:0% +next two aren't aren't quite so +necessary I think when people talk about + + align:start position:0% +necessary I think when people talk about + + + align:start position:0% +necessary I think when people talk about +being conscious of something they + + align:start position:0% +being conscious of something they + + + align:start position:0% +being conscious of something they +usually mean that they're aware of some + + align:start position:0% +usually mean that they're aware of some + + + align:start position:0% +usually mean that they're aware of some +kind of Serial sequential process they + + align:start position:0% +kind of Serial sequential process they + + + align:start position:0% +kind of Serial sequential process they +can they can say uh I thought this first + + align:start position:0% +can they can say uh I thought this first + + + align:start position:0% +can they can say uh I thought this first +and that first and and so forth uh not + + align:start position:0% +and that first and and so forth uh not + + + align:start position:0% +and that first and and so forth uh not +too insistent on that uh I'm pretty sure + + align:start position:0% +too insistent on that uh I'm pretty sure + + + align:start position:0% +too insistent on that uh I'm pretty sure +that there that it means that of course + + align:start position:0% +that there that it means that of course + + + align:start position:0% +that there that it means that of course +parts of their brain are reacting in a + + align:start position:0% +parts of their brain are reacting in a + + + align:start position:0% +parts of their brain are reacting in a +St using a statistical baset or + + align:start position:0% +St using a statistical baset or + + + align:start position:0% +St using a statistical baset or +something + + align:start position:0% +something + + + align:start position:0% +something +and one of the features of a statistical + + align:start position:0% +and one of the features of a statistical + + + align:start position:0% +and one of the features of a statistical +baset is inputs come in and outputs go + + align:start position:0% +baset is inputs come in and outputs go + + + align:start position:0% +baset is inputs come in and outputs go +out and if you stuck some probes in the + + align:start position:0% +out and if you stuck some probes in the + + + align:start position:0% +out and if you stuck some probes in the +middle you wouldn't get any information + + align:start position:0% +middle you wouldn't get any information + + + align:start position:0% +middle you wouldn't get any information +about uh How It produced that output + + align:start position:0% +about uh How It produced that output + + + align:start position:0% +about uh How It produced that output +because uh there's a great book that + + align:start position:0% +because uh there's a great book that + + + align:start position:0% +because uh there's a great book that +came out in the early 1980s called + + align:start position:0% +came out in the early 1980s called + + + align:start position:0% +came out in the early 1980s called +parallel distributed + + align:start position:0% +parallel distributed + + + align:start position:0% +parallel distributed +processing which was sort of a who's it + + align:start position:0% +processing which was sort of a who's it + + + align:start position:0% +processing which was sort of a who's it +by + + align:start position:0% +by + + + align:start position:0% +by +um I might remember in a minute + + align:start position:0% +um I might remember in a minute + + + align:start position:0% +um I might remember in a minute +the trouble is I thought Hinton and my + + align:start position:0% +the trouble is I thought Hinton and my + + + align:start position:0% +the trouble is I thought Hinton and my +theory of name recognition + + align:start position:0% +theory of name recognition + + + align:start position:0% +theory of name recognition +is + + align:start position:0% +is + + + align:start position:0% +is +what is it by mclan mlen rumel Hart + + align:start position:0% +what is it by mclan mlen rumel Hart + + + align:start position:0% +what is it by mclan mlen rumel Hart +and one + + align:start position:0% + + + + align:start position:0% + +more who's the neuro one out in West + + align:start position:0% +more who's the neuro one out in West + + + align:start position:0% +more who's the neuro one out in West +Coast Three + + align:start position:0% +Coast Three + + + align:start position:0% +Coast Three +Guys yes it's Mand rumelhart and hint I + + align:start position:0% +Guys yes it's Mand rumelhart and hint I + + + align:start position:0% +Guys yes it's Mand rumelhart and hint I +don't think Hinton was an author of that + + align:start position:0% +don't think Hinton was an author of that + + + align:start position:0% +don't think Hinton was an author of that +book is he really I think so + + align:start position:0% + + + + align:start position:0% + +maybe well it says rart ment and the PDP + + align:start position:0% +maybe well it says rart ment and the PDP + + + align:start position:0% +maybe well it says rart ment and the PDP +research group + + align:start position:0% + + + + align:start position:0% + +oh that's pretty good did you look that + + align:start position:0% +oh that's pretty good did you look that + + + align:start position:0% +oh that's pretty good did you look that +up on the + + align:start position:0% +up on the + + + align:start position:0% +up on the +web + + align:start position:0% +web + + + align:start position:0% +web +uh and you're using symbolic + + align:start position:0% +uh and you're using symbolic + + + align:start position:0% +uh and you're using symbolic +descriptions I think that's fairly + + align:start position:0% +descriptions I think that's fairly + + + align:start position:0% +descriptions I think that's fairly +necessary you can say I was conscious of + + align:start position:0% +necessary you can say I was conscious of + + + align:start position:0% +necessary you can say I was conscious of +a feeling in the pit of my + + align:start position:0% +a feeling in the pit of my + + + align:start position:0% +a feeling in the pit of my +stomach but I still claim you're using a + + align:start position:0% +stomach but I still claim you're using a + + + align:start position:0% +stomach but I still claim you're using a +symbolic description of that or you + + align:start position:0% +symbolic description of that or you + + + align:start position:0% +symbolic description of that or you +couldn't say it uh and maybe most + + align:start position:0% +couldn't say it uh and maybe most + + + align:start position:0% +couldn't say it uh and maybe most +important uh you couldn't say anything + + align:start position:0% +important uh you couldn't say anything + + + align:start position:0% +important uh you couldn't say anything +about how you made the decision unless + + align:start position:0% +about how you made the decision unless + + + align:start position:0% +about how you made the decision unless +you uh the process that's making that + + align:start position:0% +you uh the process that's making that + + + align:start position:0% +you uh the process that's making that +statement and finding the words and + + align:start position:0% +statement and finding the words and + + + align:start position:0% +statement and finding the words and +assembling that utterance um had access + + align:start position:0% +assembling that utterance um had access + + + align:start position:0% +assembling that utterance um had access +to some record of what your mind was + + align:start position:0% +to some record of what your mind was + + + align:start position:0% +to some record of what your mind was +doing recently namely + + align:start position:0% +doing recently namely + + + align:start position:0% +doing recently namely +it was trying to solve this problem and + + align:start position:0% +it was trying to solve this problem and + + + align:start position:0% +it was trying to solve this problem and +it had two Alternatives and it uh after + + align:start position:0% +it had two Alternatives and it uh after + + + align:start position:0% +it had two Alternatives and it uh after +a long time it chose this one rather + + align:start position:0% +a long time it chose this one rather + + + align:start position:0% +a long time it chose this one rather +than that one which means that uh it had + + align:start position:0% +than that one which means that uh it had + + + align:start position:0% +than that one which means that uh it had +to have a sort of symbolic + + align:start position:0% +to have a sort of symbolic + + + align:start position:0% +to have a sort of symbolic +representation it couldn't have been + + align:start position:0% +representation it couldn't have been + + + align:start position:0% +representation it couldn't have been +just a big neural net that had these + + align:start position:0% +just a big neural net that had these + + + align:start position:0% +just a big neural net that had these +waves of activity and then uh a appeared + + align:start position:0% +waves of activity and then uh a appeared + + + align:start position:0% +waves of activity and then uh a appeared +at the output instead of B because uh + + align:start position:0% +at the output instead of B because uh + + + align:start position:0% +at the output instead of B because uh +you wouldn't say I was I was deciding or + + align:start position:0% +you wouldn't say I was I was deciding or + + + align:start position:0% +you wouldn't say I was I was deciding or +you might say something was going on and + + align:start position:0% +you might say something was going on and + + + align:start position:0% +you might say something was going on and +suddenly I found myself forced to do + + align:start position:0% +suddenly I found myself forced to do + + + align:start position:0% +suddenly I found myself forced to do +this or that though which wouldn't fit + + align:start position:0% +this or that though which wouldn't fit + + + align:start position:0% +this or that though which wouldn't fit +the idea of a + + align:start position:0% +the idea of a + + + align:start position:0% +the idea of a +conscious and then the chapter has a a + + align:start position:0% +conscious and then the chapter has a a + + + align:start position:0% +conscious and then the chapter has a a +long discussion of those four + + align:start position:0% +long discussion of those four + + + align:start position:0% +long discussion of those four +ideas + + align:start position:0% +ideas + + + align:start position:0% +ideas +and I'm really not particularly happy + + align:start position:0% +and I'm really not particularly happy + + + align:start position:0% +and I'm really not particularly happy +with that particular description except + + align:start position:0% +with that particular description except + + + align:start position:0% +with that particular description except +that it leads to this + + align:start position:0% +that it leads to this + + + align:start position:0% +that it leads to this +diagram which this is a diagram + + align:start position:0% +diagram which this is a diagram + + + align:start position:0% +diagram which this is a diagram +which you could + + align:start position:0% +which you could + + + align:start position:0% +which you could +use to say when a person is + + align:start position:0% + + + + align:start position:0% + +likely oops this is the wrong + + align:start position:0% +likely oops this is the wrong + + + align:start position:0% +likely oops this is the wrong +diagram imagine all the arrows going the + + align:start position:0% +diagram imagine all the arrows going the + + + align:start position:0% +diagram imagine all the arrows going the +other way then this this is this is what + + align:start position:0% +other way then this this is this is what + + + align:start position:0% +other way then this this is this is what +I keep pointing to that instead of that + + align:start position:0% +I keep pointing to that instead of that + + + align:start position:0% +I keep pointing to that instead of that +and I didn't bring the light + + align:start position:0% +and I didn't bring the light + + + align:start position:0% +and I didn't bring the light +pen uh but if you think of that model of + + align:start position:0% +pen uh but if you think of that model of + + + align:start position:0% +pen uh but if you think of that model of +that diagram backwards you could say + + align:start position:0% +that diagram backwards you could say + + + align:start position:0% +that diagram backwards you could say +here's a piece of machinery that would + + align:start position:0% +here's a piece of machinery that would + + + align:start position:0% +here's a piece of machinery that would +account in many cases for when a person + + align:start position:0% +account in many cases for when a person + + + align:start position:0% +account in many cases for when a person +is likely to use the word + + align:start position:0% +is likely to use the word + + + align:start position:0% +is likely to use the word +conscious and you don't see anything + + align:start position:0% +conscious and you don't see anything + + + align:start position:0% +conscious and you don't see anything +like that in in in the Journal of + + align:start position:0% +like that in in in the Journal of + + + align:start position:0% +like that in in in the Journal of +Consciousness studies because they think + + align:start position:0% +Consciousness studies because they think + + + align:start position:0% +Consciousness studies because they think +Consciousness is a mysterious single + + align:start position:0% +Consciousness is a mysterious single + + + align:start position:0% +Consciousness is a mysterious single +thing and this is saying uh there isn't + + align:start position:0% +thing and this is saying uh there isn't + + + align:start position:0% +thing and this is saying uh there isn't +any such thing as Consciousness but + + align:start position:0% +any such thing as Consciousness but + + + align:start position:0% +any such thing as Consciousness but +there are a lot of mental + + align:start position:0% +there are a lot of mental + + + align:start position:0% +there are a lot of mental +activities + + align:start position:0% +activities + + + align:start position:0% +activities +which uh any of which any combination of + + align:start position:0% +which uh any of which any combination of + + + align:start position:0% +which uh any of which any combination of +which might lead a person to use the + + align:start position:0% +which might lead a person to use the + + + align:start position:0% +which might lead a person to use the +word conscious and how can you help from + + align:start position:0% +word conscious and how can you help from + + + align:start position:0% +word conscious and how can you help from +pointing to that uh and when that + + align:start position:0% +pointing to that uh and when that + + + align:start position:0% +pointing to that uh and when that +trouble detector notices that all four + + align:start position:0% +trouble detector notices that all four + + + align:start position:0% +trouble detector notices that all four +of those kinds of processes are + + align:start position:0% +of those kinds of processes are + + + align:start position:0% +of those kinds of processes are +operating + + align:start position:0% +operating + + + align:start position:0% +operating +uh perhaps in the frontal lobe of your + + align:start position:0% +uh perhaps in the frontal lobe of your + + + align:start position:0% +uh perhaps in the frontal lobe of your +brain I don't know if people who have + + align:start position:0% +brain I don't know if people who have + + + align:start position:0% +brain I don't know if people who have +lost their frontal lobe or claim to be + + align:start position:0% +lost their frontal lobe or claim to be + + + align:start position:0% +lost their frontal lobe or claim to be +conscious or + + align:start position:0% + + + + align:start position:0% + +not so there's a theory of + + align:start position:0% +not so there's a theory of + + + align:start position:0% +not so there's a theory of +of when a person might say conscious and + + align:start position:0% +of when a person might say conscious and + + + align:start position:0% +of when a person might say conscious and +I think it fits a lot of the + + align:start position:0% +I think it fits a lot of the + + + align:start position:0% +I think it fits a lot of the +descriptions of of the uh conditions + + align:start position:0% +descriptions of of the uh conditions + + + align:start position:0% +descriptions of of the uh conditions +under which people say they're conscious + + align:start position:0% +under which people say they're conscious + + + align:start position:0% +under which people say they're conscious +and uh that's the kind of theory I like + + align:start position:0% +and uh that's the kind of theory I like + + + align:start position:0% +and uh that's the kind of theory I like +to see it does still doesn't say + + align:start position:0% +to see it does still doesn't say + + + align:start position:0% +to see it does still doesn't say +what's maybe those are the four wrong + + align:start position:0% +what's maybe those are the four wrong + + + align:start position:0% +what's maybe those are the four wrong +parameters and I'd love somebody to + + align:start position:0% +parameters and I'd love somebody to + + + align:start position:0% +parameters and I'd love somebody to +suggested one that I've obviously left + + align:start position:0% +suggested one that I've obviously left + + + align:start position:0% +suggested one that I've obviously left +out and shouldn't have or or that you + + align:start position:0% +out and shouldn't have or or that you + + + align:start position:0% +out and shouldn't have or or that you +don't + + align:start position:0% + + + + align:start position:0% + +need maybe there's no reason to think + + align:start position:0% +need maybe there's no reason to think + + + align:start position:0% +need maybe there's no reason to think +that you need serial processes for this + + align:start position:0% +that you need serial processes for this + + + align:start position:0% +that you need serial processes for this +to happen or whatever I don't + + align:start position:0% +to happen or whatever I don't + + + align:start position:0% +to happen or whatever I don't +know so then there are four long + + align:start position:0% +know so then there are four long + + + align:start position:0% +know so then there are four long +sections + + align:start position:0% + + + + align:start position:0% + +about actually yeah think about it uh + + align:start position:0% +about actually yeah think about it uh + + + align:start position:0% +about actually yeah think about it uh +you probably have seral processing for + + align:start position:0% +you probably have seral processing for + + + align:start position:0% +you probably have seral processing for +langage langage processing yes if you + + align:start position:0% +langage langage processing yes if you + + + align:start position:0% +langage langage processing yes if you +are p + + align:start position:0% +are p + + + align:start position:0% +are p +feure uh on a canas might is some kind + + align:start position:0% +feure uh on a canas might is some kind + + + align:start position:0% +feure uh on a canas might is some kind +of par processing to imagine different + + align:start position:0% +of par processing to imagine different + + + align:start position:0% +of par processing to imagine different +elements in that picture or composing or + + align:start position:0% +elements in that picture or composing or + + + align:start position:0% +elements in that picture or composing or +something for harmony well certainly + + align:start position:0% +something for harmony well certainly + + + align:start position:0% +something for harmony well certainly +there so much data in a two-dimensional + + align:start position:0% +there so much data in a two-dimensional + + + align:start position:0% +there so much data in a two-dimensional +thing that uh if you had to look at each + + align:start position:0% +thing that uh if you had to look at each + + + align:start position:0% +thing that uh if you had to look at each +point separately uh you would lose track + + align:start position:0% +point separately uh you would lose track + + + align:start position:0% +point separately uh you would lose track +and you'd have to keep starting over so + + align:start position:0% +and you'd have to keep starting over so + + + align:start position:0% +and you'd have to keep starting over so +but uh I think what an artist would you + + align:start position:0% +but uh I think what an artist would you + + + align:start position:0% +but uh I think what an artist would you +ask the artist why did you uh + + align:start position:0% + + + + align:start position:0% + +why did you put that figure of a + + align:start position:0% +why did you put that figure of a + + + align:start position:0% +why did you put that figure of a +person not in the center but a little + + align:start position:0% +person not in the center but a little + + + align:start position:0% +person not in the center but a little +over to the right and uh if he were a + + align:start position:0% +over to the right and uh if he were a + + + align:start position:0% +over to the right and uh if he were a +traditional artist he might say well + + align:start position:0% +traditional artist he might say well + + + align:start position:0% +traditional artist he might say well +everyone knows that if you put something + + align:start position:0% +everyone knows that if you put something + + + align:start position:0% +everyone knows that if you put something +right in the center then the reader uh + + align:start position:0% +right in the center then the reader uh + + + align:start position:0% +right in the center then the reader uh +the viewer doesn't know whether to look + + align:start position:0% +the viewer doesn't know whether to look + + + align:start position:0% +the viewer doesn't know whether to look +left or right after they've seen the + + align:start position:0% +left or right after they've seen the + + + align:start position:0% +left or right after they've seen the +figure that people have little uh + + align:start position:0% +figure that people have little uh + + + align:start position:0% +figure that people have little uh +amateur psychological theories of of why + + align:start position:0% +amateur psychological theories of of why + + + align:start position:0% +amateur psychological theories of of why +you shouldn't put in in fact if you look + + align:start position:0% +you shouldn't put in in fact if you look + + + align:start position:0% +you shouldn't put in in fact if you look +at a book on drawing you'll find + + align:start position:0% +at a book on drawing you'll find + + + align:start position:0% +at a book on drawing you'll find +statements like it's best to put the + + align:start position:0% +statements like it's best to put the + + + align:start position:0% +statements like it's best to put the +center figure 30% from one side or the + + align:start position:0% +center figure 30% from one side or the + + + align:start position:0% +center figure 30% from one side or the +other uh not 50% and uh you certainly + + align:start position:0% +other uh not 50% and uh you certainly + + + align:start position:0% +other uh not 50% and uh you certainly +don't want to put it right in the middle + + align:start position:0% +don't want to put it right in the middle + + + align:start position:0% +don't want to put it right in the middle +uh and + + align:start position:0% +uh and + + + align:start position:0% +uh and +uh how many of you have tried to learn + + align:start position:0% +uh how many of you have tried to learn + + + align:start position:0% +uh how many of you have tried to learn +to draw from a drawing book + + align:start position:0% + + + + align:start position:0% + +they have a lot of principles and + + align:start position:0% +they have a lot of principles and + + + align:start position:0% +they have a lot of principles and +they're not all compatible oh yes but my + + align:start position:0% +they're not all compatible oh yes but my + + + align:start position:0% +they're not all compatible oh yes but my +theory of that art is the same as + + align:start position:0% +theory of that art is the same as + + + align:start position:0% +theory of that art is the same as +engineering uh there's just one big + + align:start position:0% +engineering uh there's just one big + + + align:start position:0% +engineering uh there's just one big +difference in engineering you normally + + align:start position:0% +difference in engineering you normally + + + align:start position:0% +difference in engineering you normally +have a lot of specification you have a + + align:start position:0% +have a lot of specification you have a + + + align:start position:0% +have a lot of specification you have a +lot of goals you have to achieve if + + align:start position:0% +lot of goals you have to achieve if + + + align:start position:0% +lot of goals you have to achieve if +you're making a DVD player + + align:start position:0% +you're making a DVD player + + + align:start position:0% +you're making a DVD player +uh there are a lot of constraints like + + align:start position:0% +uh there are a lot of constraints like + + + align:start position:0% +uh there are a lot of constraints like +the power button ought to be at the left + + align:start position:0% +the power button ought to be at the left + + + align:start position:0% +the power button ought to be at the left +only it isn't always there but since + + align:start position:0% +only it isn't always there but since + + + align:start position:0% +only it isn't always there but since +it's on the left in 90% of devices why + + align:start position:0% +it's on the left in 90% of devices why + + + align:start position:0% +it's on the left in 90% of devices why +is is that + + align:start position:0% +is is that + + + align:start position:0% +is is that +right raise your hand if you have + + align:start position:0% +right raise your hand if you have + + + align:start position:0% +right raise your hand if you have +a DV DVD player with the button on the + + align:start position:0% +a DV DVD player with the button on the + + + align:start position:0% +a DV DVD player with the button on the +right + + align:start position:0% +right + + + align:start position:0% +right +side what mine on the left most of them + + align:start position:0% +side what mine on the left most of them + + + align:start position:0% +side what mine on the left most of them +are on the left I have this motor rol of + + align:start position:0% +are on the left I have this motor rol of + + + align:start position:0% +are on the left I have this motor rol of +phone which + + align:start position:0% +phone which + + + align:start position:0% +phone which +uh has the + + align:start position:0% +uh has the + + + align:start position:0% +uh has the +wrong I think if you press this it goes + + align:start position:0% +wrong I think if you press this it goes + + + align:start position:0% +wrong I think if you press this it goes +off off the left side this one is on the + + align:start position:0% +off off the left side this one is on the + + + align:start position:0% +off off the left side this one is on the +right is it a Motorola + + align:start position:0% + + + + align:start position:0% + +uhhuh isn't everyone else's on the + + align:start position:0% + + + + align:start position:0% + +left yes mine's on the right + + align:start position:0% +left yes mine's on the right + + + align:start position:0% +left yes mine's on the right +uh but I used to use a some other brand + + align:start position:0% +uh but I used to use a some other brand + + + align:start position:0% +uh but I used to use a some other brand +so when the phone rings I press the one + + align:start position:0% +so when the phone rings I press the one + + + align:start position:0% +so when the phone rings I press the one +on the left and it shuts off the + + align:start position:0% +on the left and it shuts off the + + + align:start position:0% +on the left and it shuts off the +call how many of you have phones with + + align:start position:0% +call how many of you have phones with + + + align:start position:0% +call how many of you have phones with +the talk button on the + + align:start position:0% + + + + align:start position:0% + +left how many of those are motor + + align:start position:0% + + + + align:start position:0% + +rollers I talked to some executive and + + align:start position:0% +rollers I talked to some executive and + + + align:start position:0% +rollers I talked to some executive and +he said yes this was a big mistake but + + align:start position:0% +he said yes this was a big mistake but + + + align:start position:0% +he said yes this was a big mistake but +we're afraid to change + + align:start position:0% + + + + align:start position:0% + +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +so what I described the last few minutes + + align:start position:0% +so what I described the last few minutes + + + align:start position:0% +so what I described the last few minutes +was the Consciousness + + align:start position:0% +was the Consciousness + + + align:start position:0% +was the Consciousness +recognizer you were talking about how + + align:start position:0% +recognizer you were talking about how + + + align:start position:0% +recognizer you were talking about how +art is like engineering thank you uh yes + + align:start position:0% +art is like engineering thank you uh yes + + + align:start position:0% +art is like engineering thank you uh yes +and so in uh in + + align:start position:0% +and so in uh in + + + align:start position:0% +and so in uh in +engineering uh you have a bunch of goals + + align:start position:0% +engineering uh you have a bunch of goals + + + align:start position:0% +engineering uh you have a bunch of goals +you want to achieve and uh in fact + + align:start position:0% +you want to achieve and uh in fact + + + align:start position:0% +you want to achieve and uh in fact +there's a + + align:start position:0% +there's a + + + align:start position:0% +there's a +sublist which you absolutely have to + + align:start position:0% +sublist which you absolutely have to + + + align:start position:0% +sublist which you absolutely have to +achieve or the product won't work and so + + align:start position:0% +achieve or the product won't work and so + + + align:start position:0% +achieve or the product won't work and so +forth and so you focus on those and if + + align:start position:0% +forth and so you focus on those and if + + + align:start position:0% +forth and so you focus on those and if +you can make it have a few other virtues + + align:start position:0% +you can make it have a few other virtues + + + align:start position:0% +you can make it have a few other virtues +that's fine uh so there's a lot of + + align:start position:0% +that's fine uh so there's a lot of + + + align:start position:0% +that's fine uh so there's a lot of +problem solving and how do you make a + + align:start position:0% +problem solving and how do you make a + + + align:start position:0% +problem solving and how do you make a +thing that achieves these 12 goals uh in + + align:start position:0% +thing that achieves these 12 goals uh in + + + align:start position:0% +thing that achieves these 12 goals uh in +art I think it's uh the process is the + + align:start position:0% +art I think it's uh the process is the + + + align:start position:0% +art I think it's uh the process is the +same except an artist always has more + + align:start position:0% +same except an artist always has more + + + align:start position:0% +same except an artist always has more +goals than you can achieve maybe he + + align:start position:0% +goals than you can achieve maybe he + + + align:start position:0% +goals than you can achieve maybe he +wants this painting to do everything and + + align:start position:0% +wants this painting to do everything and + + + align:start position:0% +wants this painting to do everything and +uh uh I know a lot of artists and my + + align:start position:0% +uh uh I know a lot of artists and my + + + align:start position:0% +uh uh I know a lot of artists and my +impression is they spend a lot of time + + align:start position:0% +impression is they spend a lot of time + + + align:start position:0% +impression is they spend a lot of time +deciding which goals to scrap for this + + align:start position:0% +deciding which goals to scrap for this + + + align:start position:0% +deciding which goals to scrap for this +particular work like + + align:start position:0% +particular work like + + + align:start position:0% +particular work like +uh if they're going to make a bronze + + align:start position:0% +uh if they're going to make a bronze + + + align:start position:0% +uh if they're going to make a bronze +statue uh they'd like it to be eight + + align:start position:0% +statue uh they'd like it to be eight + + + align:start position:0% +statue uh they'd like it to be eight +feet tall but that would cost $60,000 so + + align:start position:0% +feet tall but that would cost $60,000 so + + + align:start position:0% +feet tall but that would cost $60,000 so +they'll make it this tall and so they + + align:start position:0% +they'll make it this tall and so they + + + align:start position:0% +they'll make it this tall and so they +give up the goal of being 8T tall + + align:start position:0% +give up the goal of being 8T tall + + + align:start position:0% +give up the goal of being 8T tall +because uh they want it to be made of + + align:start position:0% +because uh they want it to be made of + + + align:start position:0% +because uh they want it to be made of +bronze and so forth so my par this is a + + align:start position:0% +bronze and so forth so my par this is a + + + align:start position:0% +bronze and so forth so my par this is a +parody my parody of an artist is an + + align:start position:0% +parody my parody of an artist is an + + + align:start position:0% +parody my parody of an artist is an +artist is just like an engineer only the + + align:start position:0% +artist is just like an engineer only the + + + align:start position:0% +artist is just like an engineer only the +main problem is that the artist has a + + align:start position:0% +main problem is that the artist has a + + + align:start position:0% +main problem is that the artist has a +wider range of possible goals uh + + align:start position:0% +wider range of possible goals uh + + + align:start position:0% +wider range of possible goals uh +he wants to make a lot of people feel + + align:start position:0% +he wants to make a lot of people feel + + + align:start position:0% +he wants to make a lot of people feel +happy or he makes he wants to make all + + align:start position:0% +happy or he makes he wants to make all + + + align:start position:0% +happy or he makes he wants to make all +the people in the world feel terrible + + align:start position:0% +the people in the world feel terrible + + + align:start position:0% +the people in the world feel terrible +and uh but he can't achieve that so he + + align:start position:0% +and uh but he can't achieve that so he + + + align:start position:0% +and uh but he can't achieve that so he +has to make some kind of compromise so a + + align:start position:0% +has to make some kind of compromise so a + + + align:start position:0% +has to make some kind of compromise so a +lot of the artist's work goes into + + align:start position:0% +lot of the artist's work goes into + + + align:start position:0% +lot of the artist's work goes into +deciding uh what set of goals should I + + align:start position:0% +deciding uh what set of goals should I + + + align:start position:0% +deciding uh what set of goals should I +achieve in my next painting or or uh + + align:start position:0% +achieve in my next painting or or uh + + + align:start position:0% +achieve in my next painting or or uh +composition or uh sculpture or + + align:start position:0% +composition or uh sculpture or + + + align:start position:0% +composition or uh sculpture or +whatever and uh once those settle down + + align:start position:0% +whatever and uh once those settle down + + + align:start position:0% +whatever and uh once those settle down +then there's no difference between the + + align:start position:0% +then there's no difference between the + + + align:start position:0% +then there's no difference between the +artist and the engineer and he has to + + align:start position:0% +artist and the engineer and he has to + + + align:start position:0% +artist and the engineer and he has to +get this thing enough off center but not + + align:start position:0% +get this thing enough off center but not + + + align:start position:0% +get this thing enough off center but not +too much and if it if he can't get it + + align:start position:0% +too much and if it if he can't get it + + + align:start position:0% +too much and if it if he can't get it +there well maybe he can uh make a little + + align:start position:0% +there well maybe he can uh make a little + + + align:start position:0% +there well maybe he can uh make a little +more crowded stuff over here to make it + + align:start position:0% +more crowded stuff over here to make it + + + align:start position:0% +more crowded stuff over here to make it +look like it's further you know all + + align:start position:0% +look like it's further you know all + + + align:start position:0% +look like it's further you know all +those uh little interactions that every + + align:start position:0% +those uh little interactions that every + + + align:start position:0% +those uh little interactions that every +artist uh that many artists exploit so + + align:start position:0% +artist uh that many artists exploit so + + + align:start position:0% +artist uh that many artists exploit so +there's not very much difference as far + + align:start position:0% +there's not very much difference as far + + + align:start position:0% +there's not very much difference as far +as I can see they're both doing + + align:start position:0% +as I can see they're both doing + + + align:start position:0% +as I can see they're both doing +heuristic searches they have slightly + + align:start position:0% +heuristic searches they have slightly + + + align:start position:0% +heuristic searches they have slightly +different heuristics but the artist is + + align:start position:0% +different heuristics but the artist is + + + align:start position:0% +different heuristics but the artist is +more ambitious in a sense the artist + + align:start position:0% +more ambitious in a sense the artist + + + align:start position:0% +more ambitious in a sense the artist +wants to make + + align:start position:0% +wants to make + + + align:start position:0% +wants to make +everybody I don't know what the artist + + align:start position:0% +everybody I don't know what the artist + + + align:start position:0% +everybody I don't know what the artist +wants but you get the + + align:start position:0% +wants but you get the + + + align:start position:0% +wants but you get the +idea ambitious too yeah uh Steve Jobs + + align:start position:0% +idea ambitious too yeah uh Steve Jobs + + + align:start position:0% +idea ambitious too yeah uh Steve Jobs +wants everybody to not use anything + + align:start position:0% +wants everybody to not use anything + + + align:start position:0% +wants everybody to not use anything +except a Mac ever again and uh he does + + align:start position:0% +except a Mac ever again and uh he does + + + align:start position:0% +except a Mac ever again and uh he does +all sorts of things to uh make this + + align:start position:0% +all sorts of things to uh make this + + + align:start position:0% +all sorts of things to uh make this +happen and they don't + + align:start position:0% + + + + align:start position:0% + +but but he's as much as an artist as any + + align:start position:0% +but but he's as much as an artist as any + + + align:start position:0% +but but he's as much as an artist as any +artist I + + align:start position:0% + + + + align:start position:0% + +know and then the uh the other half of + + align:start position:0% +know and then the uh the other half of + + + align:start position:0% +know and then the uh the other half of +the theory is exactly the opposite + + align:start position:0% +the theory is exactly the opposite + + + align:start position:0% +the theory is exactly the opposite +namely uh why would you why are people + + align:start position:0% +namely uh why would you why are people + + + align:start position:0% +namely uh why would you why are people +conscious and the answer is when you're + + align:start position:0% +conscious and the answer is when you're + + + align:start position:0% +conscious and the answer is when you're +stuck you've been working on this + + align:start position:0% +stuck you've been working on this + + + align:start position:0% +stuck you've been working on this +problem puttering around and nothing's + + align:start position:0% +problem puttering around and nothing's + + + align:start position:0% +problem puttering around and nothing's +happening and you and you say to + + align:start position:0% +happening and you and you say to + + + align:start position:0% +happening and you and you say to +yourself well this is terrible I must + + align:start position:0% +yourself well this is terrible I must + + + align:start position:0% +yourself well this is terrible I must +think I must focus on this I have to + + align:start position:0% +think I must focus on this I have to + + + align:start position:0% +think I must focus on this I have to +concentrate I ought to crystallize what + + align:start position:0% +concentrate I ought to crystallize what + + + align:start position:0% +concentrate I ought to crystallize what +I'm doing I uh I've got to uh evaluate + + align:start position:0% +I'm doing I uh I've got to uh evaluate + + + align:start position:0% +I'm doing I uh I've got to uh evaluate +the procedures I'm using and blah blah + + align:start position:0% +the procedures I'm using and blah blah + + + align:start position:0% +the procedures I'm using and blah blah +blah and + + align:start position:0% +blah and + + + align:start position:0% +blah and +uh so I summarized this by + + align:start position:0% +uh so I summarized this by + + + align:start position:0% +uh so I summarized this by +saying that + + align:start position:0% + + + + align:start position:0% + +uh Consciousness is a great thing uh + + align:start position:0% +uh Consciousness is a great thing uh + + + align:start position:0% +uh Consciousness is a great thing uh +because uh when you're in trouble and + + align:start position:0% +because uh when you're in trouble and + + + align:start position:0% +because uh when you're in trouble and +you're not solving a problem uh I mean + + align:start position:0% +you're not solving a problem uh I mean + + + align:start position:0% +you're not solving a problem uh I mean +you can solve a lot of problems by Zen + + align:start position:0% +you can solve a lot of problems by Zen + + + align:start position:0% +you can solve a lot of problems by Zen +Buddhism uh where you just don't do + + align:start position:0% +Buddhism uh where you just don't do + + + align:start position:0% +Buddhism uh where you just don't do +anything and you don't think about the + + align:start position:0% +anything and you don't think about the + + + align:start position:0% +anything and you don't think about the +Target and and you pull this thing back + + align:start position:0% +Target and and you pull this thing back + + + align:start position:0% +Target and and you pull this thing back +and the arrow flies right into the + + align:start position:0% +and the arrow flies right into the + + + align:start position:0% +and the arrow flies right into the +bullseye uh but uh I don't care what the + + align:start position:0% +bullseye uh but uh I don't care what the + + + align:start position:0% +bullseye uh but uh I don't care what the +Zen people say the idea is if you have + + align:start position:0% +Zen people say the idea is if you have + + + align:start position:0% +Zen people say the idea is if you have +pretty good compiled code then uh + + align:start position:0% +pretty good compiled code then uh + + + align:start position:0% +pretty good compiled code then uh +thinking about it will mess it up and uh + + align:start position:0% +thinking about it will mess it up and uh + + + align:start position:0% +thinking about it will mess it up and uh +the idea that you should not think about + + align:start position:0% +the idea that you should not think about + + + align:start position:0% +the idea that you should not think about +keeping your gun steady I have great + + align:start position:0% +keeping your gun steady I have great + + + align:start position:0% +keeping your gun steady I have great +example uh + + align:start position:0% +example uh + + + align:start position:0% +example uh +I once went to the Rockefeller Institute + + align:start position:0% +I once went to the Rockefeller Institute + + + align:start position:0% +I once went to the Rockefeller Institute +with Seymour paper to talk + + align:start position:0% +with Seymour paper to talk + + + align:start position:0% +with Seymour paper to talk +to some guy about + + align:start position:0% +to some guy about + + + align:start position:0% +to some guy about +something but instead of discussing that + + align:start position:0% +something but instead of discussing that + + + align:start position:0% +something but instead of discussing that +he said well let's play + + align:start position:0% +he said well let's play + + + align:start position:0% +he said well let's play +pool they had a pool table in + + align:start position:0% +pool they had a pool table in + + + align:start position:0% +pool they had a pool table in +the recreation + + align:start position:0% +the recreation + + + align:start position:0% +the recreation +room and uh I'd never played pool so I + + align:start position:0% +room and uh I'd never played pool so I + + + align:start position:0% +room and uh I'd never played pool so I +went like that and the ball went the + + align:start position:0% +went like that and the ball went the + + + align:start position:0% +went like that and the ball went the +wrong way and uh nothing worked and he + + align:start position:0% + + + + align:start position:0% + +said I know what's wrong I said what's + + align:start position:0% +said I know what's wrong I said what's + + + align:start position:0% +said I know what's wrong I said what's +wrong and he said you're trying to hit + + align:start position:0% +wrong and he said you're trying to hit + + + align:start position:0% +wrong and he said you're trying to hit +the ball with the end of the Q stick and + + align:start position:0% +the ball with the end of the Q stick and + + + align:start position:0% +the ball with the end of the Q stick and +I said + + align:start position:0% +I said + + + align:start position:0% +I said +so and he said uh it's a very bad + + align:start position:0% +so and he said uh it's a very bad + + + align:start position:0% +so and he said uh it's a very bad +strategy what you must do is here's the + + align:start position:0% +strategy what you must do is here's the + + + align:start position:0% +strategy what you must do is here's the +bull don't try to hit the bull with the + + align:start position:0% +bull don't try to hit the bull with the + + + align:start position:0% +bull don't try to hit the bull with the +end of your Q stick imagine another bll + + align:start position:0% +end of your Q stick imagine another bll + + + align:start position:0% +end of your Q stick imagine another bll +4 in + + align:start position:0% +4 in + + + align:start position:0% +4 in +away past it and try to hit that ball + + align:start position:0% +away past it and try to hit that ball + + + align:start position:0% +away past it and try to hit that ball +with the end of your Q stick so I tried + + align:start position:0% +with the end of your Q stick so I tried + + + align:start position:0% +with the end of your Q stick so I tried +that and thing went right in the pocket + + align:start position:0% +that and thing went right in the pocket + + + align:start position:0% +that and thing went right in the pocket +and I got eight in a row without any + + align:start position:0% +and I got eight in a row without any + + + align:start position:0% +and I got eight in a row without any +practice so he said well do you know why + + align:start position:0% +practice so he said well do you know why + + + align:start position:0% +practice so he said well do you know why +that works I said well no and he said + + align:start position:0% +that works I said well no and he said + + + align:start position:0% +that works I said well no and he said +whenever you make a motion like + + align:start position:0% +whenever you make a motion like + + + align:start position:0% +whenever you make a motion like +that bring your hand as close to the + + align:start position:0% +that bring your hand as close to the + + + align:start position:0% +that bring your hand as close to the +nose as fast as + + align:start position:0% + + + + align:start position:0% + +possible well what you don't do is + + align:start position:0% +possible well what you don't do is + + + align:start position:0% +possible well what you don't do is +contract your back biceps with maximum + + align:start position:0% +contract your back biceps with maximum + + + align:start position:0% +contract your back biceps with maximum +Force because then you'll smash your + + align:start position:0% +Force because then you'll smash your + + + align:start position:0% +Force because then you'll smash your +nose what you do is you make you make + + align:start position:0% +nose what you do is you make you make + + + align:start position:0% +nose what you do is you make you make +this plan although you don't know you've + + align:start position:0% +this plan although you don't know you've + + + align:start position:0% +this plan although you don't know you've +made this plan and the plan says I'm + + align:start position:0% +made this plan and the plan says I'm + + + align:start position:0% +made this plan and the plan says I'm +going to contract my biceps until about + + align:start position:0% +going to contract my biceps until about + + + align:start position:0% +going to contract my biceps until about +gets about here and then I'm going to + + align:start position:0% +gets about here and then I'm going to + + + align:start position:0% +gets about here and then I'm going to +contract my triceps so that it stops + + align:start position:0% +contract my triceps so that it stops + + + align:start position:0% +contract my triceps so that it stops +because you see if you just + + align:start position:0% +because you see if you just + + + align:start position:0% +because you see if you just +if you don't have another muscle uh in + + align:start position:0% +if you don't have another muscle uh in + + + align:start position:0% +if you don't have another muscle uh in +the opp Opposite Direction then if you + + align:start position:0% +the opp Opposite Direction then if you + + + align:start position:0% +the opp Opposite Direction then if you +stop here it'll just coast and you'll + + align:start position:0% +stop here it'll just coast and you'll + + + align:start position:0% +stop here it'll just coast and you'll +still get a bloody nose so you're trying + + align:start position:0% +still get a bloody nose so you're trying + + + align:start position:0% +still get a bloody nose so you're trying +to stop at at the ball if you try to + + align:start position:0% +to stop at at the ball if you try to + + + align:start position:0% +to stop at at the ball if you try to +stop at the ball then your antagonist + + align:start position:0% +stop at the ball then your antagonist + + + align:start position:0% +stop at the ball then your antagonist +muscle will engage 4 Ines before you hit + + align:start position:0% +muscle will engage 4 Ines before you hit + + + align:start position:0% +muscle will engage 4 Ines before you hit +the ball and spoil your aim because this + + align:start position:0% +the ball and spoil your aim because this + + + align:start position:0% +the ball and spoil your aim because this +muscle pulls your arm here but this + + align:start position:0% +muscle pulls your arm here but this + + + align:start position:0% +muscle pulls your arm here but this +muscle is not exactly at the opposite + + align:start position:0% +muscle is not exactly at the opposite + + + align:start position:0% +muscle is not exactly at the opposite +part but it's about 10° off so you see + + align:start position:0% +part but it's about 10° off so you see + + + align:start position:0% +part but it's about 10° off so you see +as soon as that one go you're it's very + + align:start position:0% +as soon as that one go you're it's very + + + align:start position:0% +as soon as that one go you're it's very +cute so this way you fool your + + align:start position:0% +cute so this way you fool your + + + align:start position:0% +cute so this way you fool your +uh you fool your uh cerebellum and + + align:start position:0% +uh you fool your uh cerebellum and + + + align:start position:0% +uh you fool your uh cerebellum and +spinal cord from turning on it's called + + align:start position:0% +spinal cord from turning on it's called + + + align:start position:0% +spinal cord from turning on it's called +the decelerator muscle for almost every + + align:start position:0% +the decelerator muscle for almost every + + + align:start position:0% +the decelerator muscle for almost every +action there's an accelerating part and + + align:start position:0% +action there's an accelerating part and + + + align:start position:0% +action there's an accelerating part and +a decelerating part and uh as far as I + + align:start position:0% +a decelerating part and uh as far as I + + + align:start position:0% +a decelerating part and uh as far as I +can see most of what people have told me + + align:start position:0% +can see most of what people have told me + + + align:start position:0% +can see most of what people have told me +about Zen Buddhism has nothing to do + + align:start position:0% +about Zen Buddhism has nothing to do + + + align:start position:0% +about Zen Buddhism has nothing to do +with + + align:start position:0% +with + + + align:start position:0% +with +uh the simultaneous consciousness of + + align:start position:0% +uh the simultaneous consciousness of + + + align:start position:0% +uh the simultaneous consciousness of +everything in the universe or stuff like + + align:start position:0% + + + + align:start position:0% + +that almost all of it is explained by + + align:start position:0% +that almost all of it is explained by + + + align:start position:0% +that almost all of it is explained by +this is a really stupid trick for + + align:start position:0% +this is a really stupid trick for + + + align:start position:0% +this is a really stupid trick for +fooling your decelerator muscle not to + + align:start position:0% +fooling your decelerator muscle not to + + + align:start position:0% +fooling your decelerator muscle not to +spoil your aim and + + align:start position:0% +spoil your aim and + + + align:start position:0% +spoil your aim and +uh I'm very mistrustful of ancient + + align:start position:0% +uh I'm very mistrustful of ancient + + + align:start position:0% +uh I'm very mistrustful of ancient +wisdom just because if it hasn't changed + + align:start position:0% +wisdom just because if it hasn't changed + + + align:start position:0% +wisdom just because if it hasn't changed +for a thousand years then there must be + + align:start position:0% +for a thousand years then there must be + + + align:start position:0% +for a thousand years then there must be +something in the executive bureaucracy + + align:start position:0% +something in the executive bureaucracy + + + align:start position:0% +something in the executive bureaucracy +that's keeping science + + align:start position:0% +that's keeping science + + + align:start position:0% +that's keeping science +out + + align:start position:0% +out + + + align:start position:0% +out +the uh what was true in uh + + align:start position:0% +the uh what was true in uh + + + align:start position:0% +the uh what was true in uh +1700 was that there was this great + + align:start position:0% +1700 was that there was this great + + + align:start position:0% +1700 was that there was this great +caloric theory of heat that heat was a + + align:start position:0% +caloric theory of heat that heat was a + + + align:start position:0% +caloric theory of heat that heat was a +fluid and it flowed uh from the hot + + align:start position:0% +fluid and it flowed uh from the hot + + + align:start position:0% +fluid and it flowed uh from the hot +places to the cold places because + + align:start position:0% +places to the cold places because + + + align:start position:0% +places to the cold places because +there's more of it and if there was room + + align:start position:0% +there's more of it and if there was room + + + align:start position:0% +there's more of it and if there was room +to go somewhere else and it explained a + + align:start position:0% +to go somewhere else and it explained a + + + align:start position:0% +to go somewhere else and it explained a +lot of uh hiders of thermodynamics but + + align:start position:0% +lot of uh hiders of thermodynamics but + + + align:start position:0% +lot of uh hiders of thermodynamics but +not enough and the caloric theory was + + align:start position:0% +not enough and the caloric theory was + + + align:start position:0% +not enough and the caloric theory was +the best theory there had been for a + + align:start position:0% +the best theory there had been for a + + + align:start position:0% +the best theory there had been for a +couple of thousand years and it took + + align:start position:0% +couple of thousand years and it took + + + align:start position:0% +couple of thousand years and it took +about a hundred years to go away as + + align:start position:0% +about a hundred years to go away as + + + align:start position:0% +about a hundred years to go away as +the uh as the uh kinetic theory of heat + + align:start position:0% + + + + align:start position:0% + +appeared however the Zan Buddhist theory + + align:start position:0% +appeared however the Zan Buddhist theory + + + align:start position:0% +appeared however the Zan Buddhist theory +of archery doesn't go away now that we + + align:start position:0% +of archery doesn't go away now that we + + + align:start position:0% +of archery doesn't go away now that we +know about + + align:start position:0% +know about + + + align:start position:0% +know about +physiology because of you know + + align:start position:0% +physiology because of you know + + + align:start position:0% +physiology because of you know +what because there a lot of very wise + + align:start position:0% +what because there a lot of very wise + + + align:start position:0% +what because there a lot of very wise +people who make their living from it + + align:start position:0% +people who make their living from it + + + align:start position:0% +people who make their living from it +so anyway you see once you've got that + + align:start position:0% +so anyway you see once you've got that + + + align:start position:0% +so anyway you see once you've got that +theory of how you know when you're being + + align:start position:0% +theory of how you know when you're being + + + align:start position:0% +theory of how you know when you're being +conscious you see that it's not a + + align:start position:0% +conscious you see that it's not a + + + align:start position:0% +conscious you see that it's not a +complete Theory because having + + align:start position:0% +complete Theory because having + + + align:start position:0% +complete Theory because having +the concept is great uh because then if + + align:start position:0% +the concept is great uh because then if + + + align:start position:0% +the concept is great uh because then if +you're stuck and you're not doing very + + align:start position:0% +you're stuck and you're not doing very + + + align:start position:0% +you're stuck and you're not doing very +well you say well I must be more + + align:start position:0% +well you say well I must be more + + + align:start position:0% +well you say well I must be more +deliberate or conscious or + + align:start position:0% +deliberate or conscious or + + + align:start position:0% +deliberate or conscious or +uh any more synonyms for that uh + + align:start position:0% +uh any more synonyms for that uh + + + align:start position:0% +uh any more synonyms for that uh +reflective what aware yeah I should be + + align:start position:0% +reflective what aware yeah I should be + + + align:start position:0% +reflective what aware yeah I should be +more aware of what I'm doing and so as + + align:start position:0% +more aware of what I'm doing and so as + + + align:start position:0% +more aware of what I'm doing and so as +soon as you say that uh your compiler + + align:start position:0% +soon as you say that uh your compiler + + + align:start position:0% +soon as you say that uh your compiler +has compiled that into oh turn on more + + align:start position:0% +has compiled that into oh turn on more + + + align:start position:0% +has compiled that into oh turn on more +uh self models turn on more reflective + + align:start position:0% +uh self models turn on more reflective + + + align:start position:0% +uh self models turn on more reflective +processes uh get yourself working + + align:start position:0% +processes uh get yourself working + + + align:start position:0% +processes uh get yourself working +serially so that if something goes wrong + + align:start position:0% +serially so that if something goes wrong + + + align:start position:0% +serially so that if something goes wrong +with the process you'll detect it right + + align:start position:0% +with the process you'll detect it right + + + align:start position:0% +with the process you'll detect it right +away instead of it being buried in noise + + align:start position:0% +away instead of it being buried in noise + + + align:start position:0% +away instead of it being buried in noise +and uh start sorting through your recent + + align:start position:0% +and uh start sorting through your recent + + + align:start position:0% +and uh start sorting through your recent +memories to to see where you might have + + align:start position:0% +memories to to see where you might have + + + align:start position:0% +memories to to see where you might have +made your mistake and so forth so + + align:start position:0% +made your mistake and so forth so + + + align:start position:0% +made your mistake and so forth so +Consciousness is a great idea provided + + align:start position:0% +Consciousness is a great idea provided + + + align:start position:0% +Consciousness is a great idea provided +you don't believe it's it's a mysterious + + align:start position:0% +you don't believe it's it's a mysterious + + + align:start position:0% +you don't believe it's it's a mysterious +thing but say um I'm saying it's these + + align:start position:0% +thing but say um I'm saying it's these + + + align:start position:0% +thing but say um I'm saying it's these +four things I'm really hoping somebody + + align:start position:0% +four things I'm really hoping somebody + + + align:start position:0% +four things I'm really hoping somebody +will find five others that are pretty + + align:start position:0% +will find five others that are pretty + + + align:start position:0% +will find five others that are pretty +different that yeah isn't isn't the it + + align:start position:0% +different that yeah isn't isn't the it + + + align:start position:0% +different that yeah isn't isn't the it +seems like the trouble detector is kind + + align:start position:0% +seems like the trouble detector is kind + + + align:start position:0% +seems like the trouble detector is kind +of the hard part right like so what the + + align:start position:0% +of the hard part right like so what the + + + align:start position:0% +of the hard part right like so what the +trouble detector is kind of so I mean if + + align:start position:0% +trouble detector is kind of so I mean if + + + align:start position:0% +trouble detector is kind of so I mean if +I'm if I'm doing a task and my brain is + + align:start position:0% +I'm if I'm doing a task and my brain is + + + align:start position:0% +I'm if I'm doing a task and my brain is +sort of involved in something it's sort + + align:start position:0% +sort of involved in something it's sort + + + align:start position:0% +sort of involved in something it's sort +of like when do you know + + align:start position:0% +of like when do you know + + + align:start position:0% +of like when do you know +that you know enough now is the time to + + align:start position:0% +that you know enough now is the time to + + + align:start position:0% +that you know enough now is the time to +you know bring it up level well the rest + + align:start position:0% +you know bring it up level well the rest + + + align:start position:0% +you know bring it up level well the rest +of the book is about uh these things + + align:start position:0% +of the book is about uh these things + + + align:start position:0% +of the book is about uh these things +called critics and maybe this trouble + + align:start position:0% +called critics and maybe this trouble + + + align:start position:0% +called critics and maybe this trouble +detector is one of the first examples + + align:start position:0% +detector is one of the first examples + + + align:start position:0% +detector is one of the first examples +then I generalize it and say all all + + align:start position:0% +then I generalize it and say all all + + + align:start position:0% +then I generalize it and say all all +thinking involves doing stuff you know + + align:start position:0% +thinking involves doing stuff you know + + + align:start position:0% +thinking involves doing stuff you know +how to do but having other things + + align:start position:0% +how to do but having other things + + + align:start position:0% +how to do but having other things +recognizing not that you're in trouble + + align:start position:0% +recognizing not that you're in trouble + + + align:start position:0% +recognizing not that you're in trouble +but what kind of trouble you're in and + + align:start position:0% +but what kind of trouble you're in and + + + align:start position:0% +but what kind of trouble you're in and +this Consciousness detector is maybe + + align:start position:0% +this Consciousness detector is maybe + + + align:start position:0% +this Consciousness detector is maybe +what you do when everything else has + + align:start position:0% +what you do when everything else has + + + align:start position:0% +what you do when everything else has +failed at lower levels and you're still + + align:start position:0% +failed at lower levels and you're still + + + align:start position:0% +failed at lower levels and you're still +screwing up and it says well uh screw + + align:start position:0% +screwing up and it says well uh screw + + + align:start position:0% +screwing up and it says well uh screw +those lower levels let's get some + + align:start position:0% +those lower levels let's get some + + + align:start position:0% +those lower levels let's get some +reflective symbolic analytical serial + + align:start position:0% +reflective symbolic analytical serial + + + align:start position:0% +reflective symbolic analytical serial +logical processes going and see if we + + align:start position:0% +logical processes going and see if we + + + align:start position:0% +logical processes going and see if we +can take this thing apart and find in + + align:start position:0% +can take this thing apart and find in + + + align:start position:0% +can take this thing apart and find in +other words instead of I'm I'm made of + + align:start position:0% +other words instead of I'm I'm made of + + + align:start position:0% +other words instead of I'm I'm made of +bad protoplasm I can't aim you're saying + + align:start position:0% +bad protoplasm I can't aim you're saying + + + align:start position:0% +bad protoplasm I can't aim you're saying +well uh is there some other way I can + + align:start position:0% +well uh is there some other way I can + + + align:start position:0% +well uh is there some other way I can +fool my uh + + align:start position:0% +fool my uh + + + align:start position:0% +fool my uh +whatever I'm doing for + + align:start position:0% +whatever I'm doing for + + + align:start position:0% +whatever I'm doing for +example uh if you've ever shot a gun + + align:start position:0% +example uh if you've ever shot a gun + + + align:start position:0% +example uh if you've ever shot a gun +which I uh once I was once in the Navy + + align:start position:0% +which I uh once I was once in the Navy + + + align:start position:0% +which I uh once I was once in the Navy +and we got some + + align:start position:0% +and we got some + + + align:start position:0% +and we got some +training and one of the things is that + + align:start position:0% +training and one of the things is that + + + align:start position:0% +training and one of the things is that +uh if you're firing a 3030 rifle it's a + + align:start position:0% +uh if you're firing a 3030 rifle it's a + + + align:start position:0% +uh if you're firing a 3030 rifle it's a +big bang and it really hurts and so + + align:start position:0% +big bang and it really hurts and so + + + align:start position:0% +big bang and it really hurts and so +forth so just as about to pull the + + align:start position:0% +forth so just as about to pull the + + + align:start position:0% +forth so just as about to pull the +trigger you wince because you're + + align:start position:0% +trigger you wince because you're + + + align:start position:0% +trigger you wince because you're +expecting this terrible noise and and + + align:start position:0% +expecting this terrible noise and and + + + align:start position:0% +expecting this terrible noise and and +uh so uh you have to turn off + + align:start position:0% +uh so uh you have to turn off + + + align:start position:0% +uh so uh you have to turn off +uh you have to figure out some way to uh + + align:start position:0% +uh you have to figure out some way to uh + + + align:start position:0% +uh you have to figure out some way to uh +and what some people say is uh you + + align:start position:0% +and what some people say is uh you + + + align:start position:0% +and what some people say is uh you +should squeeze the trigger so slowly + + align:start position:0% +should squeeze the trigger so slowly + + + align:start position:0% +should squeeze the trigger so slowly +that you don't know when it's going to + + align:start position:0% +that you don't know when it's going to + + + align:start position:0% +that you don't know when it's going to +go off and that way you won't wince just + + align:start position:0% +go off and that way you won't wince just + + + align:start position:0% +go off and that way you won't wince just +as as it happens because it takes 100 + + align:start position:0% +as as it happens because it takes 100 + + + align:start position:0% +as as it happens because it takes 100 +milliseconds to react to something by + + align:start position:0% +milliseconds to react to something by + + + align:start position:0% +milliseconds to react to something by +that time the bullet is on its + + align:start position:0% +that time the bullet is on its + + + align:start position:0% +that time the bullet is on its +way you know human reaction time is + + align:start position:0% +way you know human reaction time is + + + align:start position:0% +way you know human reaction time is +a between 100 and + + align:start position:0% +a between 100 and + + + align:start position:0% +a between 100 and +200 one and two 2 t0 of a + + align:start position:0% +200 one and two 2 t0 of a + + + align:start position:0% +200 one and two 2 t0 of a +second so + + align:start position:0% +second so + + + align:start position:0% +second so +uh my colleague Seymour papert did a lot + + align:start position:0% +uh my colleague Seymour papert did a lot + + + align:start position:0% +uh my colleague Seymour papert did a lot +of research on juggling and in fact uh + + align:start position:0% +of research on juggling and in fact uh + + + align:start position:0% +of research on juggling and in fact uh +we hired uh professional jugglers to + + align:start position:0% +we hired uh professional jugglers to + + + align:start position:0% +we hired uh professional jugglers to +tell us how they did it and the most + + align:start position:0% +tell us how they did it and the most + + + align:start position:0% +tell us how they did it and the most +important piece of advice is don't keep + + align:start position:0% +important piece of advice is don't keep + + + align:start position:0% +important piece of advice is don't keep +your eye on the + + align:start position:0% +your eye on the + + + align:start position:0% +your eye on the +bull because if you juggle one bll and + + align:start position:0% +bull because if you juggle one bll and + + + align:start position:0% +bull because if you juggle one bll and +you track it there's no problem if there + + align:start position:0% +you track it there's no problem if there + + + align:start position:0% +you track it there's no problem if there +two the first place you can't keep your + + align:start position:0% +two the first place you can't keep your + + + align:start position:0% +two the first place you can't keep your +eye on the bll and the second place if + + align:start position:0% +eye on the bll and the second place if + + + align:start position:0% +eye on the bll and the second place if +the ball is over here and your hand is + + align:start position:0% +the ball is over here and your hand is + + + align:start position:0% +the ball is over here and your hand is +here it's too + + align:start position:0% +here it's too + + + align:start position:0% +here it's too +late so in fact what a good juggler does + + align:start position:0% +late so in fact what a good juggler does + + + align:start position:0% +late so in fact what a good juggler does +is you only look up here and you look at + + align:start position:0% +is you only look up here and you look at + + + align:start position:0% +is you only look up here and you look at +you look for the top of the parabola + + align:start position:0% +you look for the top of the parabola + + + align:start position:0% +you look for the top of the parabola +which is a great time because the Bull's + + align:start position:0% +which is a great time because the Bull's + + + align:start position:0% +which is a great time because the Bull's +going really slowly and you've got + + align:start position:0% +going really slowly and you've got + + + align:start position:0% +going really slowly and you've got +plenty of time and then some part of + + align:start position:0% +plenty of time and then some part of + + + align:start position:0% +plenty of time and then some part of +your brain extrapolates that and gets + + align:start position:0% +your brain extrapolates that and gets + + + align:start position:0% +your brain extrapolates that and gets +your hand ready to go there of course in + + align:start position:0% +your hand ready to go there of course in + + + align:start position:0% +your hand ready to go there of course in +the meantime there's another Bowl that's + + align:start position:0% +the meantime there's another Bowl that's + + + align:start position:0% +the meantime there's another Bowl that's +already gone by and your hand is was + + align:start position:0% +already gone by and your hand is was + + + align:start position:0% +already gone by and your hand is was +here to receive it but uh after about 40 + + align:start position:0% +here to receive it but uh after about 40 + + + align:start position:0% +here to receive it but uh after about 40 +minutes the average person is able to uh + + align:start position:0% +minutes the average person is able to uh + + + align:start position:0% +minutes the average person is able to uh +get two or two of these going and uh + + align:start position:0% +get two or two of these going and uh + + + align:start position:0% +get two or two of these going and uh +less than two hours if you really focus + + align:start position:0% +less than two hours if you really focus + + + align:start position:0% +less than two hours if you really focus +you can start doing three Ball Juggling + + align:start position:0% +you can start doing three Ball Juggling + + + align:start position:0% +you can start doing three Ball Juggling +uh we actually had a PhD thesis on this + + align:start position:0% +uh we actually had a PhD thesis on this + + + align:start position:0% +uh we actually had a PhD thesis on this +by a clever guy named Howard Austin and + + align:start position:0% +by a clever guy named Howard Austin and + + + align:start position:0% +by a clever guy named Howard Austin and +Austin uh took all these notes that we + + align:start position:0% +Austin uh took all these notes that we + + + align:start position:0% +Austin uh took all these notes that we +had made from The Professional uh + + align:start position:0% +had made from The Professional uh + + + align:start position:0% +had made from The Professional uh +jugglers and uh set up a course and the + + align:start position:0% +jugglers and uh set up a course and the + + + align:start position:0% +jugglers and uh set up a course and the +course was how to juggle and it had + + align:start position:0% +course was how to juggle and it had + + + align:start position:0% +course was how to juggle and it had +three basic principles the most + + align:start position:0% +three basic principles the most + + + align:start position:0% +three basic principles the most +important principle was that uh one + + align:start position:0% +important principle was that uh one + + + align:start position:0% +important principle was that uh one +mistake you're liable to make is that + + align:start position:0% +mistake you're liable to make is that + + + align:start position:0% +mistake you're liable to make is that +the ball goes forward so you step + + align:start position:0% +the ball goes forward so you step + + + align:start position:0% +the ball goes forward so you step +forward to get it well then you're + + align:start position:0% +forward to get it well then you're + + + align:start position:0% +forward to get it well then you're +doomed because the next ball is going to + + align:start position:0% +doomed because the next ball is going to + + + align:start position:0% +doomed because the next ball is going to +go further and you crash into the wool + + align:start position:0% +go further and you crash into the wool + + + align:start position:0% +go further and you crash into the wool +uh and the way the pros deal with + + align:start position:0% +uh and the way the pros deal with + + + align:start position:0% +uh and the way the pros deal with +beginners is that is that you juggle + + align:start position:0% +beginners is that is that you juggle + + + align:start position:0% +beginners is that is that you juggle +right next to the wall so you can't walk + + align:start position:0% +right next to the wall so you can't walk + + + align:start position:0% +right next to the wall so you can't walk +forward and that cures + + align:start position:0% +forward and that cures + + + align:start position:0% +forward and that cures +that and then there's the uh looking at + + align:start position:0% +that and then there's the uh looking at + + + align:start position:0% +that and then there's the uh looking at +the looking up here with what going on + + align:start position:0% +the looking up here with what going on + + + align:start position:0% +the looking up here with what going on +and because if you look here it's too + + align:start position:0% +and because if you look here it's too + + + align:start position:0% +and because if you look here it's too +late you can't react and you can't learn + + align:start position:0% +late you can't react and you can't learn + + + align:start position:0% +late you can't react and you can't learn +much and I forget the third + + align:start position:0% +much and I forget the third + + + align:start position:0% +much and I forget the third +rule but the joke was that it took uh + + align:start position:0% +rule but the joke was that it took uh + + + align:start position:0% +rule but the joke was that it took uh +the untrained people about 40 minutes to + + align:start position:0% +the untrained people about 40 minutes to + + + align:start position:0% +the untrained people about 40 minutes to +reach a certain skill level uh and with + + align:start position:0% +reach a certain skill level uh and with + + + align:start position:0% +reach a certain skill level uh and with +Howard's 20 minute course then it took + + align:start position:0% +Howard's 20 minute course then it took + + + align:start position:0% +Howard's 20 minute course then it took +them only 20 more minutes + + align:start position:0% +them only 20 more minutes + + + align:start position:0% +them only 20 more minutes +to reach that skill level and uh he came + + align:start position:0% +to reach that skill level and uh he came + + + align:start position:0% +to reach that skill level and uh he came +out with this wonderful collection of + + align:start position:0% +out with this wonderful collection of + + + align:start position:0% +out with this wonderful collection of +data which says it takes 40 minutes to + + align:start position:0% +data which says it takes 40 minutes to + + + align:start position:0% +data which says it takes 40 minutes to +learn to juggle this well whether you + + align:start position:0% +learn to juggle this well whether you + + + align:start position:0% +learn to juggle this well whether you +teach your whether you're trained or + + align:start position:0% +teach your whether you're trained or + + + align:start position:0% +teach your whether you're trained or +not um which we regarded as a great + + align:start position:0% +not um which we regarded as a great + + + align:start position:0% +not um which we regarded as a great +positive result but other people said + + align:start position:0% +positive result but other people said + + + align:start position:0% +positive result but other people said +what's the use then if it + + align:start position:0% +what's the use then if it + + + align:start position:0% +what's the use then if it +doesn't uh but the conjecture is maybe + + align:start position:0% +doesn't uh but the conjecture is maybe + + + align:start position:0% +doesn't uh but the conjecture is maybe +for five bow got juggling + + align:start position:0% +for five bow got juggling + + + align:start position:0% +for five bow got juggling +juggling something like that would help + + align:start position:0% +juggling something like that would help + + + align:start position:0% +juggling something like that would help +even more since no normal person ever + + align:start position:0% +even more since no normal person ever + + + align:start position:0% +even more since no normal person ever +gets that far any of you + + align:start position:0% + + + + align:start position:0% + +juggle + + align:start position:0% +juggle + + + align:start position:0% +juggle +problem who a Juggle problem set + + align:start position:0% +problem who a Juggle problem set + + + align:start position:0% +problem who a Juggle problem set +sometimes + + align:start position:0% +sometimes + + + align:start position:0% +sometimes +yes yes how do you decide which problem + + align:start position:0% +yes yes how do you decide which problem + + + align:start position:0% +yes yes how do you decide which problem +to work on next the one that's most + + align:start position:0% +to work on next the one that's most + + + align:start position:0% +to work on next the one that's most +attractive or the one that you want to + + align:start position:0% +attractive or the one that you want to + + + align:start position:0% +attractive or the one that you want to +get it over with we were + + align:start position:0% +get it over with we were + + + align:start position:0% +get it over with we were +just anyway I that's all I wanted to say + + align:start position:0% +just anyway I that's all I wanted to say + + + align:start position:0% +just anyway I that's all I wanted to say +about this + + align:start position:0% +about this + + + align:start position:0% +about this +there's all sorts of other stories in + + align:start position:0% +there's all sorts of other stories in + + + align:start position:0% +there's all sorts of other stories in +this + + align:start position:0% +this + + + align:start position:0% +this +and toward the end of the + + align:start position:0% +and toward the end of the + + + align:start position:0% +and toward the end of the +chapter oh here's here's where I start + + align:start position:0% +chapter oh here's here's where I start + + + align:start position:0% +chapter oh here's here's where I start +talking about Chalmer I didn't discuss + + align:start position:0% +talking about Chalmer I didn't discuss + + + align:start position:0% +talking about Chalmer I didn't discuss +the zombie machine problem here uh maybe + + align:start position:0% +the zombie machine problem here uh maybe + + + align:start position:0% +the zombie machine problem here uh maybe +I'll uh I have a draft of it which I + + align:start position:0% +I'll uh I have a draft of it which I + + + align:start position:0% +I'll uh I have a draft of it which I +didn't put in the book about why it's + + align:start position:0% +didn't put in the book about why it's + + + align:start position:0% +didn't put in the book about why it's +not logically possible that there there + + align:start position:0% +not logically possible that there there + + + align:start position:0% +not logically possible that there there +could be two machines I might be wrong + + align:start position:0% +could be two machines I might be wrong + + + align:start position:0% +could be two machines I might be wrong +it's a nice argument though uh however + + align:start position:0% +it's a nice argument though uh however + + + align:start position:0% +it's a nice argument though uh however +uh + + align:start position:0% +uh + + + align:start position:0% +uh +right uh this week I we have a + + align:start position:0% +right uh this week I we have a + + + align:start position:0% +right uh this week I we have a +visitor Professor takabayashi from uh + + align:start position:0% +visitor Professor takabayashi from uh + + + align:start position:0% +visitor Professor takabayashi from uh +what's it called + + align:start position:0% + + + + align:start position:0% + +University uh uh I've known him for more + + align:start position:0% +University uh uh I've known him for more + + + align:start position:0% +University uh uh I've known him for more +than 20 years and we've worked together + + align:start position:0% +than 20 years and we've worked together + + + align:start position:0% +than 20 years and we've worked together +from time to time on all sorts of + + align:start position:0% +from time to time on all sorts of + + + align:start position:0% +from time to time on all sorts of +different problems uh he's uh expert in + + align:start position:0% +different problems uh he's uh expert in + + + align:start position:0% +different problems uh he's uh expert in +Signal processing + + align:start position:0% +Signal processing + + + align:start position:0% +Signal processing +made any number of inventions I think he + + align:start position:0% +made any number of inventions I think he + + + align:start position:0% +made any number of inventions I think he +you made the first telephone where you + + align:start position:0% +you made the first telephone where you + + + align:start position:0% +you made the first telephone where you +could speak numbers and it would dial + + align:start position:0% +could speak numbers and it would dial + + + align:start position:0% +could speak numbers and it would dial +and did did toi at toiba did they ever + + align:start position:0% +and did did toi at toiba did they ever + + + align:start position:0% +and did did toi at toiba did they ever +make a product of that did it sell yes + + align:start position:0% +make a product of that did it sell yes + + + align:start position:0% +make a product of that did it sell yes +oh + + align:start position:0% + + + + align:start position:0% + +good and he made some speech recognition + + align:start position:0% +good and he made some speech recognition + + + align:start position:0% +good and he made some speech recognition +systems that were quite good uh I know + + align:start position:0% +systems that were quite good uh I know + + + align:start position:0% +systems that were quite good uh I know +some people here who made speech + + align:start position:0% +some people here who made speech + + + align:start position:0% +some people here who made speech +recognition systems and they wanted to + + align:start position:0% +recognition systems and they wanted to + + + align:start position:0% +recognition systems and they wanted to +make one which would still work if there + + align:start position:0% +make one which would still work if there + + + align:start position:0% +make one which would still work if there +were a lot of noise so because they had + + align:start position:0% +were a lot of noise so because they had + + + align:start position:0% +were a lot of noise so because they had +some + + align:start position:0% +some + + + align:start position:0% +some +mathematical training they said well of + + align:start position:0% +mathematical training they said well of + + + align:start position:0% +mathematical training they said well of +course White gaussian Noise would be the + + align:start position:0% +course White gaussian Noise would be the + + + align:start position:0% +course White gaussian Noise would be the +best thing and + + align:start position:0% +best thing and + + + align:start position:0% +best thing and +uh yoichi + + align:start position:0% +uh yoichi + + + align:start position:0% +uh yoichi +takabayashi didn't think white noise was + + align:start position:0% +takabayashi didn't think white noise was + + + align:start position:0% +takabayashi didn't think white noise was +good so uh he made a lot of tapes of + + align:start position:0% +good so uh he made a lot of tapes of + + + align:start position:0% +good so uh he made a lot of tapes of +people saying numbers in the middle of + + align:start position:0% +people saying numbers in the middle of + + + align:start position:0% +people saying numbers in the middle of +Tokyo Station which is the noisiest + + align:start position:0% +Tokyo Station which is the noisiest + + + align:start position:0% +Tokyo Station which is the noisiest +place in the world maybe and it's full + + align:start position:0% +place in the world maybe and it's full + + + align:start position:0% +place in the world maybe and it's full +of every kind of noise so uh somehow + + align:start position:0% +of every kind of noise so uh somehow + + + align:start position:0% +of every kind of noise so uh somehow +that made his system robust enough to be + + align:start position:0% +that made his system robust enough to be + + + align:start position:0% +that made his system robust enough to be +a product but anyway uh for the last few + + align:start position:0% +a product but anyway uh for the last few + + + align:start position:0% +a product but anyway uh for the last few +years he he quit industry became a + + align:start position:0% +years he he quit industry became a + + + align:start position:0% +years he he quit industry became a +professor and is doing some very + + align:start position:0% +professor and is doing some very + + + align:start position:0% +professor and is doing some very +interesting things on Common Sense and + + align:start position:0% +interesting things on Common Sense and + + + align:start position:0% +interesting things on Common Sense and +uh this kind of uh highlevel cognitive + + align:start position:0% +uh this kind of uh highlevel cognitive + + + align:start position:0% +uh this kind of uh highlevel cognitive +theory so he's going to show you some + + align:start position:0% +theory so he's going to show you some + + + align:start position:0% +theory so he's going to show you some +interesting examples of that that we're + + align:start position:0% +interesting examples of that that we're + + + align:start position:0% +interesting examples of that that we're +we're very interested + + align:start position:0% + + + + align:start position:0% + +in as m inod uce me um I used to work + + align:start position:0% +in as m inod uce me um I used to work + + + align:start position:0% +in as m inod uce me um I used to work +for the signal processing and uh speech + + align:start position:0% +for the signal processing and uh speech + + + align:start position:0% +for the signal processing and uh speech +recognition and also multimod speech + + align:start position:0% +recognition and also multimod speech + + + align:start position:0% +recognition and also multimod speech +dialogue system I'm the first person to + + align:start position:0% +dialogue system I'm the first person to + + + align:start position:0% +dialogue system I'm the first person to +develop the spontaneous speech dialogue + + align:start position:0% +develop the spontaneous speech dialogue + + + align:start position:0% +develop the spontaneous speech dialogue +system it + + align:start position:0% +system it + + + align:start position:0% +system it +works um very uh NOA NOA but the problem + + align:start position:0% +works um very uh NOA NOA but the problem + + + align:start position:0% +works um very uh NOA NOA but the problem +is is Task + + align:start position:0% +is is Task + + + align:start position:0% +is is Task +oriented then the Marin criticize me + + align:start position:0% +oriented then the Marin criticize me + + + align:start position:0% +oriented then the Marin criticize me +it's a toy system so I decided to + + align:start position:0% +it's a toy system so I decided to + + + align:start position:0% +it's a toy system so I decided to +develop a system + + align:start position:0% +develop a system + + + align:start position:0% +develop a system +um uh which have the common sense but uh + + align:start position:0% +um uh which have the common sense but uh + + + align:start position:0% +um uh which have the common sense but uh +uh still the common sense means just a + + align:start position:0% +uh still the common sense means just a + + + align:start position:0% +uh still the common sense means just a +white color common sense then I um + + align:start position:0% +white color common sense then I um + + + align:start position:0% +white color common sense then I um +attended the Marvin class that more than + + align:start position:0% +attended the Marvin class that more than + + + align:start position:0% +attended the Marvin class that more than +20 years ago to be exact + + align:start position:0% +20 years ago to be exact + + + align:start position:0% +20 years ago to be exact +1986 and uh at that time he wrote a book + + align:start position:0% +1986 and uh at that time he wrote a book + + + align:start position:0% +1986 and uh at that time he wrote a book +and Society mind I learn lot from him + + align:start position:0% +and Society mind I learn lot from him + + + align:start position:0% +and Society mind I learn lot from him +then the I and now um so I have been + + align:start position:0% +then the I and now um so I have been + + + align:start position:0% +then the I and now um so I have been +working for uh TOA for more than 20 + + align:start position:0% +working for uh TOA for more than 20 + + + align:start position:0% +working for uh TOA for more than 20 +years then I moved to the shiza + + align:start position:0% +years then I moved to the shiza + + + align:start position:0% +years then I moved to the shiza +university as a professor then I have a + + align:start position:0% +university as a professor then I have a + + + align:start position:0% +university as a professor then I have a +lot of freedom to do the basic research + + align:start position:0% +lot of freedom to do the basic research + + + align:start position:0% +lot of freedom to do the basic research +then I started the + + align:start position:0% +then I started the + + + align:start position:0% +then I started the +infant and the uh learning and research + + align:start position:0% +infant and the uh learning and research + + + align:start position:0% +infant and the uh learning and research +so today I I'll introduce about the + + align:start position:0% +so today I I'll introduce about the + + + align:start position:0% +so today I I'll introduce about the +present research on the um infant the + + align:start position:0% +present research on the um infant the + + + align:start position:0% +present research on the um infant the +learning actually it's a common sense + + align:start position:0% +learning actually it's a common sense + + + align:start position:0% +learning actually it's a common sense +computing + + align:start position:0% + + + + align:start position:0% + +um this is a whole um the + + align:start position:0% +um this is a whole um the + + + align:start position:0% +um this is a whole um the +um scope of our uh infant learning + + align:start position:0% +um scope of our uh infant learning + + + align:start position:0% +um scope of our uh infant learning +project so um the Japanese people are + + align:start position:0% +project so um the Japanese people are + + + align:start position:0% +project so um the Japanese people are +good at are making a product in real + + align:start position:0% +good at are making a product in real + + + align:start position:0% +good at are making a product in real +world not conceptually but uh I used to + + align:start position:0% +world not conceptually but uh I used to + + + align:start position:0% +world not conceptually but uh I used to +work for under the speech recognition + + align:start position:0% +work for under the speech recognition + + + align:start position:0% +work for under the speech recognition +system for practical system as a + + align:start position:0% +system for practical system as a + + + align:start position:0% +system for practical system as a +commercial product uh we observed lots + + align:start position:0% +commercial product uh we observed lots + + + align:start position:0% +commercial product uh we observed lots +of data to extract the very essential + + align:start position:0% +of data to extract the very essential + + + align:start position:0% +of data to extract the very essential +component and uh uh so uh I myself I + + align:start position:0% +component and uh uh so uh I myself I + + + align:start position:0% +component and uh uh so uh I myself I +think I believe I know that's important + + align:start position:0% +think I believe I know that's important + + + align:start position:0% +think I believe I know that's important +and that's trivial so uh uh then we + + align:start position:0% +and that's trivial so uh uh then we + + + align:start position:0% +and that's trivial so uh uh then we +started this uh infant running product + + align:start position:0% +started this uh infant running product + + + align:start position:0% +started this uh infant running product +um + + align:start position:0% +um + + + align:start position:0% +um +project um + + align:start position:0% + + + + align:start position:0% + +oops the uh we have the classroom the uh + + align:start position:0% +oops the uh we have the classroom the uh + + + align:start position:0% +oops the uh we have the classroom the uh +actually the co education environment + + align:start position:0% +actually the co education environment + + + align:start position:0% +actually the co education environment +for parents and infants + + align:start position:0% +for parents and infants + + + align:start position:0% +for parents and infants +because um in + + align:start position:0% +because um in + + + align:start position:0% +because um in +Japan um the infants are changing and + + align:start position:0% +Japan um the infants are changing and + + + align:start position:0% +Japan um the infants are changing and +parents are + + align:start position:0% +parents are + + + align:start position:0% +parents are +changing uh Japan used to be very safe + + align:start position:0% +changing uh Japan used to be very safe + + + align:start position:0% +changing uh Japan used to be very safe +country um very few the um the crimes + + align:start position:0% +country um very few the um the crimes + + + align:start position:0% +country um very few the um the crimes +and uh uh when I was the + + align:start position:0% +and uh uh when I was the + + + align:start position:0% +and uh uh when I was the +kid uh we we didn't lock my house it's + + align:start position:0% +kid uh we we didn't lock my house it's + + + align:start position:0% +kid uh we we didn't lock my house it's +very + + align:start position:0% +very + + + align:start position:0% +very +safe um the first time I went to Japan I + + align:start position:0% +safe um the first time I went to Japan I + + + align:start position:0% +safe um the first time I went to Japan I +had a 12-year-old daughter uh-huh and uh + + align:start position:0% +had a 12-year-old daughter uh-huh and uh + + + align:start position:0% +had a 12-year-old daughter uh-huh and uh +she wanted to go and look at Kyoto and + + align:start position:0% +she wanted to go and look at Kyoto and + + + align:start position:0% +she wanted to go and look at Kyoto and +everybody said it's perfectly + + align:start position:0% +everybody said it's perfectly + + + align:start position:0% +everybody said it's perfectly +safe so she went all by herself and uh + + align:start position:0% +safe so she went all by herself and uh + + + align:start position:0% +safe so she went all by herself and uh +but now it's very dangerous it's + + align:start position:0% +but now it's very dangerous it's + + + align:start position:0% +but now it's very dangerous it's +dangerous so that I never tell you the + + align:start position:0% +dangerous so that I never tell you the + + + align:start position:0% +dangerous so that I never tell you the +story she went to an arcade uhhuh which + + align:start position:0% +story she went to an arcade uhhuh which + + + align:start position:0% +story she went to an arcade uhhuh which +had a uh arcade game called gallaga mhm + + align:start position:0% +had a uh arcade game called gallaga mhm + + + align:start position:0% +had a uh arcade game called gallaga mhm +and it had a lot of boys playing it and + + align:start position:0% +and it had a lot of boys playing it and + + + align:start position:0% +and it had a lot of boys playing it and +uh so she had some coins so she got a + + align:start position:0% +uh so she had some coins so she got a + + + align:start position:0% +uh so she had some coins so she got a +turn and then uh she broke the + + align:start position:0% +turn and then uh she broke the + + + align:start position:0% +turn and then uh she broke the +record uh she kept uh shooting down more + + align:start position:0% +record uh she kept uh shooting down more + + + align:start position:0% +record uh she kept uh shooting down more +whatever they were and when she finished + + align:start position:0% +whatever they were and when she finished + + + align:start position:0% +whatever they were and when she finished +all the boys had + + align:start position:0% + + + + align:start position:0% + +disappeared but anyway the we are + + align:start position:0% +disappeared but anyway the we are + + + align:start position:0% +disappeared but anyway the we are +designing the um the classroom infant + + align:start position:0% +designing the um the classroom infant + + + align:start position:0% +designing the um the classroom infant +classroom and the playroom and the uh so + + align:start position:0% +classroom and the playroom and the uh so + + + align:start position:0% +classroom and the playroom and the uh so +the um the the the the purpose um for + + align:start position:0% +the um the the the the purpose um for + + + align:start position:0% +the um the the the the purpose um for +our research is to develop the common + + align:start position:0% +our research is to develop the common + + + align:start position:0% +our research is to develop the common +sense Computing model and also the um + + align:start position:0% +sense Computing model and also the um + + + align:start position:0% +sense Computing model and also the um +the uh designing and developing the the + + align:start position:0% +the uh designing and developing the the + + + align:start position:0% +the uh designing and developing the the +good materials for uh infant education + + align:start position:0% +good materials for uh infant education + + + align:start position:0% +good materials for uh infant education +and the infant learning so the uh we are + + align:start position:0% +and the infant learning so the uh we are + + + align:start position:0% +and the infant learning so the uh we are +focusing on the um um + + align:start position:0% +focusing on the um um + + + align:start position:0% +focusing on the um um +the um constructing infant Behavior + + align:start position:0% +the um constructing infant Behavior + + + align:start position:0% +the um constructing infant Behavior +Corpus so Marin told um many um good the + + align:start position:0% +Corpus so Marin told um many um good the + + + align:start position:0% +Corpus so Marin told um many um good the +Articles related to the how mind works + + align:start position:0% +Articles related to the how mind works + + + align:start position:0% +Articles related to the how mind works +and and the common sense that works but + + align:start position:0% +and and the common sense that works but + + + align:start position:0% +and and the common sense that works but +U um infant is very uh simple relatively + + align:start position:0% +U um infant is very uh simple relatively + + + align:start position:0% +U um infant is very uh simple relatively +uh much simpler than the adults so we + + align:start position:0% +uh much simpler than the adults so we + + + align:start position:0% +uh much simpler than the adults so we +started this research um and this kind + + align:start position:0% +started this research um and this kind + + + align:start position:0% +started this research um and this kind +of + + align:start position:0% +of + + + align:start position:0% +of +research so the again the purpose of the + + align:start position:0% +research so the again the purpose of the + + + align:start position:0% +research so the again the purpose of the +project is constru um conduct basic + + align:start position:0% +project is constru um conduct basic + + + align:start position:0% +project is constru um conduct basic +Common Sense resarch Bas based on the + + align:start position:0% +Common Sense resarch Bas based on the + + + align:start position:0% +Common Sense resarch Bas based on the +scientific data real world data + + align:start position:0% + + + + align:start position:0% + +um infant expressions are genuine and + + align:start position:0% +um infant expressions are genuine and + + + align:start position:0% +um infant expressions are genuine and +good for modeling it's easy easier and + + align:start position:0% +good for modeling it's easy easier and + + + align:start position:0% +good for modeling it's easy easier and +uh um then produce Rich theories for + + align:start position:0% +uh um then produce Rich theories for + + + align:start position:0% +uh um then produce Rich theories for +common sense + + align:start position:0% +common sense + + + align:start position:0% +common sense +Computing um the and the other purpose + + align:start position:0% +Computing um the and the other purpose + + + align:start position:0% +Computing um the and the other purpose +is support healthy development of the + + align:start position:0% +is support healthy development of the + + + align:start position:0% +is support healthy development of the +infant as I mentioned earlier the + + align:start position:0% +infant as I mentioned earlier the + + + align:start position:0% +infant as I mentioned earlier the +parents is an important is parenting is + + align:start position:0% +parents is an important is parenting is + + + align:start position:0% +parents is an important is parenting is +an important issu in Japan now and I + + align:start position:0% +an important issu in Japan now and I + + + align:start position:0% +an important issu in Japan now and I +think in this country + + align:start position:0% +think in this country + + + align:start position:0% +think in this country +and uh and also created multimodal + + align:start position:0% +and uh and also created multimodal + + + align:start position:0% +and uh and also created multimodal +knowledge contents for parir + + align:start position:0% +knowledge contents for parir + + + align:start position:0% +knowledge contents for parir +renting so uh this is this is a trick + + align:start position:0% +renting so uh this is this is a trick + + + align:start position:0% +renting so uh this is this is a trick +the this um infant learning itself is + + align:start position:0% +the this um infant learning itself is + + + align:start position:0% +the this um infant learning itself is +very good + + align:start position:0% +very good + + + align:start position:0% +very good +applications um I hope Japanese + + align:start position:0% +applications um I hope Japanese + + + align:start position:0% +applications um I hope Japanese +government and the US government fing it + + align:start position:0% +government and the US government fing it + + + align:start position:0% +government and the US government fing it +now now oh Japanese government + + align:start position:0% +now now oh Japanese government + + + align:start position:0% +now now oh Japanese government +uhuh that's more funding and this is our + + align:start position:0% +uhuh that's more funding and this is our + + + align:start position:0% +uhuh that's more funding and this is our +the cross room um I'll show you this + + align:start position:0% +the cross room um I'll show you this + + + align:start position:0% +the cross room um I'll show you this +demos brief + + align:start position:0% + + + + align:start position:0% + +explanations it's very + + align:start position:0% + + + + align:start position:0% + +usual so um this is made by CA trees um + + align:start position:0% +usual so um this is made by CA trees um + + + align:start position:0% +usual so um this is made by CA trees um +CA Tre is that causes lots of allergy in + + align:start position:0% +CA Tre is that causes lots of allergy in + + + align:start position:0% +CA Tre is that causes lots of allergy in +in your country country but it's good + + align:start position:0% +in your country country but it's good + + + align:start position:0% +in your country country but it's good +for the um uh child classroom infant + + align:start position:0% + + + + align:start position:0% + +classroom + + align:start position:0% + + + + align:start position:0% + +Goku it's faster this afternoon yeah + + align:start position:0% +Goku it's faster this afternoon yeah + + + align:start position:0% +Goku it's faster this afternoon yeah +it's the building yeah building yeah uh + + align:start position:0% +it's the building yeah building yeah uh + + + align:start position:0% +it's the building yeah building yeah uh +the uh see that three um the trees and + + align:start position:0% +the uh see that three um the trees and + + + align:start position:0% +the uh see that three um the trees and +the uh four cameras + + align:start position:0% +the uh four cameras + + + align:start position:0% +the uh four cameras +and uh + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah it's different + + align:start position:0% + + + + align:start position:0% + +okay I'll be back to that + + align:start position:0% + + + + align:start position:0% + +the oh this is a um the scenary of the + + align:start position:0% +the oh this is a um the scenary of the + + + align:start position:0% +the oh this is a um the scenary of the +education okay + + align:start position:0% + + + + align:start position:0% + +the um the mothers and the + + align:start position:0% +the um the mothers and the + + + align:start position:0% +the um the mothers and the +infants they're working together + + align:start position:0% +infants they're working together + + + align:start position:0% +infants they're working together +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +hardly any of our kids go to school at + + align:start position:0% +hardly any of our kids go to school at + + + align:start position:0% +hardly any of our kids go to school at +age one sorry we don't have many + + align:start position:0% +age one sorry we don't have many + + + align:start position:0% +age one sorry we don't have many +children in school at age one yeah same + + align:start position:0% +children in school at age one yeah same + + + align:start position:0% +children in school at age one yeah same +thing happen in Japan and uh uh it's + + align:start position:0% +thing happen in Japan and uh uh it's + + + align:start position:0% +thing happen in Japan and uh uh it's +good actually in Japan the um the + + align:start position:0% +good actually in Japan the um the + + + align:start position:0% +good actually in Japan the um the +government controlled the um the + + align:start position:0% +government controlled the um the + + + align:start position:0% +government controlled the um the +elementary school but uh before the + + align:start position:0% +elementary school but uh before the + + + align:start position:0% +elementary school but uh before the +elementary SCH it's very free oh so we + + align:start position:0% +elementary SCH it's very free oh so we + + + align:start position:0% +elementary SCH it's very free oh so we +can do our own you know sat to do the + + align:start position:0% +can do our own you know sat to do the + + + align:start position:0% +can do our own you know sat to do the +good + + align:start position:0% + + + + align:start position:0% + +educations so the um practice of of + + align:start position:0% +educations so the um practice of of + + + align:start position:0% +educations so the um practice of of +infant school is uh we are now U have + + align:start position:0% +infant school is uh we are now U have + + + align:start position:0% +infant school is uh we are now U have +participants of one two three year old + + align:start position:0% +participants of one two three year old + + + align:start position:0% +participants of one two three year old +the children and their mothers but from + + align:start position:0% +the children and their mothers but from + + + align:start position:0% +the children and their mothers but from +the uh next April we have one two four + + align:start position:0% +the uh next April we have one two four + + + align:start position:0% +the uh next April we have one two four +years children so we are + + align:start position:0% +years children so we are + + + align:start position:0% +years children so we are +continuously doing the experiment to do + + align:start position:0% +continuously doing the experiment to do + + + align:start position:0% +continuously doing the experiment to do +research and for Designing the good uh + + align:start position:0% +research and for Designing the good uh + + + align:start position:0% +research and for Designing the good uh +environment that's very good because in + + align:start position:0% +environment that's very good because in + + + align:start position:0% +environment that's very good because in +a 100 Years you'll have + + align:start position:0% + + + + align:start position:0% + +everyone so uh yeah you can have a + + align:start position:0% +everyone so uh yeah you can have a + + + align:start position:0% +everyone so uh yeah you can have a +chance to do this kind + + align:start position:0% +chance to do this kind + + + align:start position:0% +chance to do this kind +of so the um the classroom is uh uh half + + align:start position:0% +of so the um the classroom is uh uh half + + + align:start position:0% +of so the um the classroom is uh uh half +an hour and the prum and parenting and + + align:start position:0% +an hour and the prum and parenting and + + + align:start position:0% +an hour and the prum and parenting and +counseling is a half half half an hour + + align:start position:0% +counseling is a half half half an hour + + + align:start position:0% +counseling is a half half half an hour +again this is a trick it's good for the + + align:start position:0% +again this is a trick it's good for the + + + align:start position:0% +again this is a trick it's good for the +the U parents so we can get scientific + + align:start position:0% +the U parents so we can get scientific + + + align:start position:0% +the U parents so we can get scientific +data to do research to the basic + + align:start position:0% +data to do research to the basic + + + align:start position:0% +data to do research to the basic +research so the um the at this moment + + align:start position:0% +research so the um the at this moment + + + align:start position:0% +research so the um the at this moment +the long-term recording of data we um 22 + + align:start position:0% +the long-term recording of data we um 22 + + + align:start position:0% +the long-term recording of data we um 22 +months uh um since um + + align:start position:0% +months uh um since um + + + align:start position:0% +months uh um since um +June of + + align:start position:0% +June of + + + align:start position:0% +June of +2005 and + + align:start position:0% +2005 and + + + align:start position:0% +2005 and +uh 146 occasions of classroom and + + align:start position:0% +uh 146 occasions of classroom and + + + align:start position:0% +uh 146 occasions of classroom and +playrooms the more than 200 hours of + + align:start position:0% +playrooms the more than 200 hours of + + + align:start position:0% +playrooms the more than 200 hours of +recording the movie of the speech + + align:start position:0% + + + + align:start position:0% + +data and uh um we we we are trying to + + align:start position:0% +data and uh um we we we are trying to + + + align:start position:0% +data and uh um we we we are trying to +accumulate of um Child Care knoow from + + align:start position:0% +accumulate of um Child Care knoow from + + + align:start position:0% +accumulate of um Child Care knoow from +Child Care the clinic to the + + align:start position:0% +Child Care the clinic to the + + + align:start position:0% +Child Care the clinic to the +family uh uh it is the um good for the + + align:start position:0% +family uh uh it is the um good for the + + + align:start position:0% +family uh uh it is the um good for the +family and uh um so that's why we can um + + align:start position:0% +family and uh um so that's why we can um + + + align:start position:0% +family and uh um so that's why we can um +and do the very useful the um + + align:start position:0% +and do the very useful the um + + + align:start position:0% +and do the very useful the um +experiment like um + + align:start position:0% +experiment like um + + + align:start position:0% +experiment like um +parents + + align:start position:0% +parents + + + align:start position:0% +parents +uh um um connecting to the uh our uh the + + align:start position:0% +uh um um connecting to the uh our uh the + + + align:start position:0% +uh um um connecting to the uh our uh the +class + + align:start position:0% +class + + + align:start position:0% +class +and other schools are related can be + + align:start position:0% +and other schools are related can be + + + align:start position:0% +and other schools are related can be +related to the um our + + align:start position:0% + + + + align:start position:0% + +classes + + align:start position:0% +classes + + + align:start position:0% +classes +okay and uh the um the but the um the + + align:start position:0% +okay and uh the um the but the um the + + + align:start position:0% +okay and uh the um the but the um the +reason five that to do our the um + + align:start position:0% +reason five that to do our the um + + + align:start position:0% +reason five that to do our the um +project is a + + align:start position:0% +project is a + + + align:start position:0% +project is a +um the um based on the the Marvin's the + + align:start position:0% +um the um based on the the Marvin's the + + + align:start position:0% +um the um based on the the Marvin's the +emotion machine book especially the the + + align:start position:0% +emotion machine book especially the the + + + align:start position:0% +emotion machine book especially the the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +practice of a pushes scenario um + + align:start position:0% +practice of a pushes scenario um + + + align:start position:0% +practice of a pushes scenario um +we uh I'll will show you very + + align:start position:0% +we uh I'll will show you very + + + align:start position:0% +we uh I'll will show you very +interesting uh the um experimental data + + align:start position:0% +interesting uh the um experimental data + + + align:start position:0% +interesting uh the um experimental data +um the uh we put the blocks in the + + align:start position:0% +um the uh we put the blocks in the + + + align:start position:0% +um the uh we put the blocks in the +playroom and uh infants did + + align:start position:0% +playroom and uh infants did + + + align:start position:0% +playroom and uh infants did +collaboration by accident the this is uh + + align:start position:0% +collaboration by accident the this is uh + + + align:start position:0% +collaboration by accident the this is uh +I'll show you the which is the driver + + align:start position:0% +I'll show you the which is the driver + + + align:start position:0% +I'll show you the which is the driver +task + + align:start position:0% + + + + align:start position:0% + +not the want + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +so it's a truck + + align:start position:0% +so it's a truck + + + align:start position:0% +so it's a truck +car yeah yeah truck um + + align:start position:0% + + + + align:start position:0% + +the like a bus + + align:start position:0% + + + + align:start position:0% + +now audio doesn't work well + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +sound yeah no no no actually the uh some + + align:start position:0% +sound yeah no no no actually the uh some + + + align:start position:0% +sound yeah no no no actually the uh some +the background program is right + + align:start position:0% +the background program is right + + + align:start position:0% +the background program is right +[Music] + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% + + + + align:start position:0% + +Microsoft that's how babies cry in + + align:start position:0% +Microsoft that's how babies cry in + + + align:start position:0% +Microsoft that's how babies cry in +Japanese + + align:start position:0% +Japanese + + + align:start position:0% +Japanese +[Laughter] + + align:start position:0% + + + + align:start position:0% + +so um the among the lots of recorded + + align:start position:0% +so um the among the lots of recorded + + + align:start position:0% +so um the among the lots of recorded +data we can choose the very the uh + + align:start position:0% +data we can choose the very the uh + + + align:start position:0% +data we can choose the very the uh +interesting the parts + + align:start position:0% + + + + align:start position:0% + +he's actually giving the steering wheel + + align:start position:0% + + + + align:start position:0% + +yeah how old are they two um three and + + align:start position:0% +yeah how old are they two um three and + + + align:start position:0% +yeah how old are they two um three and +four okay + + align:start position:0% +four okay + + + align:start position:0% +four okay +so because younger ones wouldn't + + align:start position:0% +so because younger ones wouldn't + + + align:start position:0% +so because younger ones wouldn't +negotiate that + + align:start position:0% + + + + align:start position:0% + +well have they seen the movie from push + + align:start position:0% +well have they seen the movie from push + + + align:start position:0% +well have they seen the movie from push +Theses I don't think so push sing wrote + + align:start position:0% +Theses I don't think so push sing wrote + + + align:start position:0% +Theses I don't think so push sing wrote +his PhD Theses with a model of the first + + align:start position:0% +his PhD Theses with a model of the first + + + align:start position:0% +his PhD Theses with a model of the first +three layers of + + align:start position:0% +three layers of + + + align:start position:0% +three layers of +the motion machine architecture that has + + align:start position:0% +the motion machine architecture that has + + + align:start position:0% +the motion machine architecture that has +two + + align:start position:0% +two + + + align:start position:0% +two +robots and one runs into trouble and the + + align:start position:0% +robots and one runs into trouble and the + + + align:start position:0% +robots and one runs into trouble and the +other figures out + + align:start position:0% +other figures out + + + align:start position:0% +other figures out +how to help + + align:start position:0% +how to help + + + align:start position:0% +how to help +it you program at threeyear Old to + + align:start position:0% +it you program at threeyear Old to + + + align:start position:0% +it you program at threeyear Old to +do yeah um actually the um oh and this + + align:start position:0% +do yeah um actually the um oh and this + + + align:start position:0% +do yeah um actually the um oh and this +is a problem solving um and is a example + + align:start position:0% + + + + align:start position:0% + +so sometimes um they use a he use a + + align:start position:0% +so sometimes um they use a he use a + + + align:start position:0% +so sometimes um they use a he use a +higher + + align:start position:0% +higher + + + align:start position:0% +higher +level the + + align:start position:0% + + + + align:start position:0% + +knowledge for + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +spe + + align:start position:0% + + + + align:start position:0% + +spee speech + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +spe + + align:start position:0% + + + + align:start position:0% + +spee + + align:start position:0% + + + + align:start position:0% + +now we have cameras the on the top + + align:start position:0% +now we have cameras the on the top + + + align:start position:0% +now we have cameras the on the top +what's the speed record yeah + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +sorry the audio doesn't work + + align:start position:0% +sorry the audio doesn't work + + + align:start position:0% +sorry the audio doesn't work +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +well they usually the more cute + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +uh we are uh describing this Behavior + + align:start position:0% +uh we are uh describing this Behavior + + + align:start position:0% +uh we are uh describing this Behavior +using a knowledge representation langage + + align:start position:0% +using a knowledge representation langage + + + align:start position:0% +using a knowledge representation langage +like e EMR emotion machine and the type + + align:start position:0% +like e EMR emotion machine and the type + + + align:start position:0% +like e EMR emotion machine and the type +representation by push + + align:start position:0% +representation by push + + + align:start position:0% +representation by push +and did you ask him what his goals are + + align:start position:0% +and did you ask him what his goals are + + + align:start position:0% +and did you ask him what his goals are +yeah but uh we uh we uh we have a + + align:start position:0% +yeah but uh we uh we uh we have a + + + align:start position:0% +yeah but uh we uh we uh we have a +conference what the and the the about + + align:start position:0% +conference what the and the the about + + + align:start position:0% +conference what the and the the about +the goals and what the uh the reasons or + + align:start position:0% +the goals and what the uh the reasons or + + + align:start position:0% +the goals and what the uh the reasons or +some the behaviors so every uh um the um + + align:start position:0% +some the behaviors so every uh um the um + + + align:start position:0% +some the behaviors so every uh um the um +week we have discussions what's going on + + align:start position:0% +week we have discussions what's going on + + + align:start position:0% +week we have discussions what's going on +there + + align:start position:0% +there + + + align:start position:0% +there +and but it's hard to tell ask the infant + + align:start position:0% + + + + align:start position:0% + +[Laughter] + + align:start position:0% + + + + align:start position:0% + +s think worth mentioning that in uh in + + align:start position:0% +s think worth mentioning that in uh in + + + align:start position:0% +s think worth mentioning that in uh in +modern + + align:start position:0% + + + + align:start position:0% + +psychology people are trained to do + + align:start position:0% +psychology people are trained to do + + + align:start position:0% +psychology people are trained to do +experiments and they have large numbers + + align:start position:0% +experiments and they have large numbers + + + align:start position:0% +experiments and they have large numbers +of subjects and control groups and they + + align:start position:0% +of subjects and control groups and they + + + align:start position:0% +of subjects and control groups and they +do the same thing with 50 Children and + + align:start position:0% +do the same thing with 50 Children and + + + align:start position:0% +do the same thing with 50 Children and +then some slightly different thing with + + align:start position:0% +then some slightly different thing with + + + align:start position:0% +then some slightly different thing with +50 others and there's very little + + align:start position:0% +50 others and there's very little + + + align:start position:0% +50 others and there's very little +support for experiments like this uh but + + align:start position:0% +support for experiments like this uh but + + + align:start position:0% +support for experiments like this uh but +historically almost a very large + + align:start position:0% +historically almost a very large + + + align:start position:0% +historically almost a very large +fraction of what we know about young + + align:start position:0% +fraction of what we know about young + + + align:start position:0% +fraction of what we know about young +children comes from the + + align:start position:0% +children comes from the + + + align:start position:0% +children comes from the +psychology psychologist John P who + + align:start position:0% +psychology psychologist John P who + + + align:start position:0% +psychology psychologist John P who +studied three children for many + + align:start position:0% +studied three children for many + + + align:start position:0% +studied three children for many +years uh also my friend Bob ller studied + + align:start position:0% +years uh also my friend Bob ller studied + + + align:start position:0% +years uh also my friend Bob ller studied +three children for many years and they + + align:start position:0% +three children for many years and they + + + align:start position:0% +three children for many years and they +learn a lot about the child's + + align:start position:0% +learn a lot about the child's + + + align:start position:0% +learn a lot about the child's +development whereas it's very hard in + + align:start position:0% +development whereas it's very hard in + + + align:start position:0% +development whereas it's very hard in +modern psychology + + align:start position:0% +modern psychology + + + align:start position:0% +modern psychology +because they want statisticians to say + + align:start position:0% +because they want statisticians to say + + + align:start position:0% +because they want statisticians to say +What's significant so you need 50 + + align:start position:0% +What's significant so you need 50 + + + align:start position:0% +What's significant so you need 50 +Children and then if uh enough of the + + align:start position:0% +Children and then if uh enough of the + + + align:start position:0% +Children and then if uh enough of the +children do the same thing then that's + + align:start position:0% +children do the same thing then that's + + + align:start position:0% +children do the same thing then that's +that's what you publish but what you + + align:start position:0% +that's what you publish but what you + + + align:start position:0% +that's what you publish but what you +really want all children are different + + align:start position:0% +really want all children are different + + + align:start position:0% +really want all children are different +you really want to know what happens in + + align:start position:0% +you really want to know what happens in + + + align:start position:0% +you really want to know what happens in +the course of one child's + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +development + + align:start position:0% +development + + + align:start position:0% +development +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +fore spee + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +so she knows it's to be broken yes + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so this is the audio and video data and + + align:start position:0% +so this is the audio and video data and + + + align:start position:0% +so this is the audio and video data and +uh again we uh we we're trying to to + + align:start position:0% +uh again we uh we we're trying to to + + + align:start position:0% +uh again we uh we we're trying to to +describe the um this Behavior by natural + + align:start position:0% +describe the um this Behavior by natural + + + align:start position:0% +describe the um this Behavior by natural +language and also the um knowledge um um + + align:start position:0% +language and also the um knowledge um um + + + align:start position:0% +language and also the um knowledge um um +AI type knowledge representation + + align:start position:0% +AI type knowledge representation + + + align:start position:0% +AI type knowledge representation +language so did he switch to building + + align:start position:0% +language so did he switch to building + + + align:start position:0% +language so did he switch to building +because she said + + align:start position:0% +because she said + + + align:start position:0% +because she said +to oh + + align:start position:0% + + + + align:start position:0% + +yeah very good + + align:start position:0% + + + + align:start position:0% + +at + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +speech spee + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +so um I don't U give the good + + align:start position:0% +so um I don't U give the good + + + align:start position:0% +so um I don't U give the good +demo so um so + + align:start position:0% + + + + align:start position:0% + +um so have you assembled a sequence of + + align:start position:0% +um so have you assembled a sequence of + + + align:start position:0% +um so have you assembled a sequence of +one of the child's development yet + + align:start position:0% +one of the child's development yet + + + align:start position:0% +one of the child's development yet +sorry have you have you got snaps of + + align:start position:0% +sorry have you have you got snaps of + + + align:start position:0% +sorry have you have you got snaps of +what one child does for 3 years yeah um + + align:start position:0% +what one child does for 3 years yeah um + + + align:start position:0% +what one child does for 3 years yeah um +the again um um this year um the um just + + align:start position:0% +the again um um this year um the um just + + + align:start position:0% +the again um um this year um the um just +the um the third year so we can um + + align:start position:0% +the um the third year so we can um + + + align:start position:0% +the um the third year so we can um +collect the the the fourth the same + + align:start position:0% +collect the the the fourth the same + + + align:start position:0% +collect the the the fourth the same +child now for three years the Child + + align:start position:0% +child now for three years the Child + + + align:start position:0% +child now for three years the Child +Development because it would be nice to + + align:start position:0% +Development because it would be nice to + + + align:start position:0% +Development because it would be nice to +know how she gets the idea of + + align:start position:0% +know how she gets the idea of + + + align:start position:0% +know how she gets the idea of +cooperating yes + + align:start position:0% + + + + align:start position:0% + +so you mention that you use the EM1 + + align:start position:0% +so you mention that you use the EM1 + + + align:start position:0% +so you mention that you use the EM1 +representation yes example that + + align:start position:0% +representation yes example that + + + align:start position:0% +representation yes example that +yeah oh so we can see I think uses it + + align:start position:0% +yeah oh so we can see I think uses it + + + align:start position:0% +yeah oh so we can see I think uses it +for taking notes by saying this action + + align:start position:0% +for taking notes by saying this action + + + align:start position:0% +for taking notes by saying this action +might show level + + align:start position:0% +might show level + + + align:start position:0% +might show level +for + + align:start position:0% +for + + + align:start position:0% +for +okay so I I + + align:start position:0% + + + + align:start position:0% + +give so uh this kind of explanation um + + align:start position:0% +give so uh this kind of explanation um + + + align:start position:0% +give so uh this kind of explanation um +this reflective thinking level and + + align:start position:0% +this reflective thinking level and + + + align:start position:0% +this reflective thinking level and +self-reflective thinking and uh uh so we + + align:start position:0% +self-reflective thinking and uh uh so we + + + align:start position:0% +self-reflective thinking and uh uh so we +can describe the behavior using multi- + + align:start position:0% +can describe the behavior using multi- + + + align:start position:0% +can describe the behavior using multi- +level the representation the that uh uh + + align:start position:0% +level the representation the that uh uh + + + align:start position:0% +level the representation the that uh uh +you are learning in this class but you + + align:start position:0% +you are learning in this class but you + + + align:start position:0% +you are learning in this class but you +don't know if the boy yeah thinks that + + align:start position:0% +don't know if the boy yeah thinks that + + + align:start position:0% +don't know if the boy yeah thinks that +about the mother in that case does he is + + align:start position:0% +about the mother in that case does he is + + + align:start position:0% +about the mother in that case does he is +there any evidence oh it's a just a + + align:start position:0% +there any evidence oh it's a just a + + + align:start position:0% +there any evidence oh it's a just a +assumption and uh we are just um the um + + align:start position:0% +assumption and uh we are just um the um + + + align:start position:0% +assumption and uh we are just um the um +the thinking and discussing what's going + + align:start position:0% +the thinking and discussing what's going + + + align:start position:0% +the thinking and discussing what's going +on so um the uh description is not just + + align:start position:0% +on so um the uh description is not just + + + align:start position:0% +on so um the uh description is not just +a single multi + + align:start position:0% +a single multi + + + align:start position:0% +a single multi +ways but uh the um getting more and more + + align:start position:0% +ways but uh the um getting more and more + + + align:start position:0% +ways but uh the um getting more and more +data and uh um making the model I think + + align:start position:0% +data and uh um making the model I think + + + align:start position:0% +data and uh um making the model I think +um in the room now yes oh so you could + + align:start position:0% +um in the room now yes oh so you could + + + align:start position:0% +um in the room now yes oh so you could +see if he looks over it her yeah uh + + align:start position:0% +see if he looks over it her yeah uh + + + align:start position:0% +see if he looks over it her yeah uh +sometime oh this case is not no uh no + + align:start position:0% + + + + align:start position:0% + +parents so um this is such kind of + + align:start position:0% +parents so um this is such kind of + + + align:start position:0% +parents so um this is such kind of +representations + + align:start position:0% + + + + align:start position:0% + +and we have a graphical user interface + + align:start position:0% +and we have a graphical user interface + + + align:start position:0% +and we have a graphical user interface +to put the um the um the functions of + + align:start position:0% +to put the um the um the functions of + + + align:start position:0% +to put the um the um the functions of +the + + align:start position:0% + + + + align:start position:0% + +EM1 if you had a picture of mother it + + align:start position:0% +EM1 if you had a picture of mother it + + + align:start position:0% +EM1 if you had a picture of mother it +would be interesting to see if his + + align:start position:0% +would be interesting to see if his + + + align:start position:0% +would be interesting to see if his +strategy is different yeah actually the + + align:start position:0% +strategy is different yeah actually the + + + align:start position:0% +strategy is different yeah actually the +uh we I gave up the um videos for one + + align:start position:0% +uh we I gave up the um videos for one + + + align:start position:0% +uh we I gave up the um videos for one +year long you + + align:start position:0% +year long you + + + align:start position:0% +year long you +know uh infant development + + align:start position:0% +know uh infant development + + + align:start position:0% +know uh infant development +for the + + align:start position:0% +for the + + + align:start position:0% +for the +service it's a good souvenir for + + align:start position:0% +service it's a good souvenir for + + + align:start position:0% +service it's a good souvenir for +grandparents + + align:start position:0% +grandparents + + + align:start position:0% +grandparents +and as a d DVD + + align:start position:0% + + + + align:start position:0% + +format but P has a nice + + align:start position:0% +format but P has a nice + + + align:start position:0% +format but P has a nice +story I'm sure you all know the famous + + align:start position:0% +story I'm sure you all know the famous + + + align:start position:0% +story I'm sure you all know the famous +experiment of P where you pour water + + align:start position:0% +experiment of P where you pour water + + + align:start position:0% +experiment of P where you pour water +from a whole thin glass into a short fat + + align:start position:0% +from a whole thin glass into a short fat + + + align:start position:0% +from a whole thin glass into a short fat +glass + + align:start position:0% +glass + + + align:start position:0% +glass +and + + align:start position:0% +and + + + align:start position:0% +and +U paper did a lot of those experiments + + align:start position:0% +U paper did a lot of those experiments + + + align:start position:0% +U paper did a lot of those experiments +in Geneva with + + align:start position:0% +in Geneva with + + + align:start position:0% +in Geneva with +P so typically the 5-year-old thinks + + align:start position:0% +P so typically the 5-year-old thinks + + + align:start position:0% +P so typically the 5-year-old thinks +there's more in the OR says there's more + + align:start position:0% +there's more in the OR says there's more + + + align:start position:0% +there's more in the OR says there's more +water in the to one so he had a boy who + + align:start position:0% +water in the to one so he had a boy who + + + align:start position:0% +water in the to one so he had a boy who +had had a movie of a boy doing that and + + align:start position:0% +had had a movie of a boy doing that and + + + align:start position:0% +had had a movie of a boy doing that and +then when the boy was seven seven years + + align:start position:0% +then when the boy was seven seven years + + + align:start position:0% +then when the boy was seven seven years +old uh he did the same experiment and + + align:start position:0% +old uh he did the same experiment and + + + align:start position:0% +old uh he did the same experiment and +the boy said well of course equal it's + + align:start position:0% +the boy said well of course equal it's + + + align:start position:0% +the boy said well of course equal it's +the same + + align:start position:0% +the same + + + align:start position:0% +the same +order and then peer showed the boy the + + align:start position:0% +order and then peer showed the boy the + + + align:start position:0% +order and then peer showed the boy the +movie two years ago where he said + + align:start position:0% +movie two years ago where he said + + + align:start position:0% +movie two years ago where he said +there's more and the boy gets very angry + + align:start position:0% +there's more and the boy gets very angry + + + align:start position:0% +there's more and the boy gets very angry +and said I never believed that and uh + + align:start position:0% +and said I never believed that and uh + + + align:start position:0% +and said I never believed that and uh +ABT said well there's the movie and the + + align:start position:0% +ABT said well there's the movie and the + + + align:start position:0% +ABT said well there's the movie and the +boy said you must have uh had somebody + + align:start position:0% +boy said you must have uh had somebody + + + align:start position:0% +boy said you must have uh had somebody +make up this fake movie I was never so + + align:start position:0% + + + + align:start position:0% + +stupid it's kind of infant Amnesia of + + align:start position:0% +stupid it's kind of infant Amnesia of + + + align:start position:0% +stupid it's kind of infant Amnesia of +very strong + + align:start position:0% +very strong + + + align:start position:0% +very strong +form boy didn't believe any he could + + align:start position:0% +form boy didn't believe any he could + + + align:start position:0% +form boy didn't believe any he could +ever have made that + + align:start position:0% + + + + align:start position:0% + +mistake so you can use that on yeah you + + align:start position:0% +mistake so you can use that on yeah you + + + align:start position:0% +mistake so you can use that on yeah you +can show them the video in three years + + align:start position:0% +can show them the video in three years + + + align:start position:0% +can show them the video in three years +and see they believe + + align:start position:0% +and see they believe + + + align:start position:0% +and see they believe +it so the um it's a just ongoing project + + align:start position:0% +it so the um it's a just ongoing project + + + align:start position:0% +it so the um it's a just ongoing project +but uh um we want to U develop the um + + align:start position:0% +but uh um we want to U develop the um + + + align:start position:0% +but uh um we want to U develop the um +computational model for common sense + + align:start position:0% +computational model for common sense + + + align:start position:0% +computational model for common sense +reason uh I I think it is not only for + + align:start position:0% +reason uh I I think it is not only for + + + align:start position:0% +reason uh I I think it is not only for +the infant um some of some part of this + + align:start position:0% +the infant um some of some part of this + + + align:start position:0% +the infant um some of some part of this +uh the common sense reasoning model uh + + align:start position:0% +uh the common sense reasoning model uh + + + align:start position:0% +uh the common sense reasoning model uh +work for the U adults I we believe and + + align:start position:0% +work for the U adults I we believe and + + + align:start position:0% +work for the U adults I we believe and +uh so um this is just a the six months + + align:start position:0% +uh so um this is just a the six months + + + align:start position:0% +uh so um this is just a the six months +long project and as far as the the + + align:start position:0% +long project and as far as the the + + + align:start position:0% +long project and as far as the the +modeling we are collecting the data um + + align:start position:0% +modeling we are collecting the data um + + + align:start position:0% +modeling we are collecting the data um +we the building more the models for the + + align:start position:0% +we the building more the models for the + + + align:start position:0% +we the building more the models for the +um Common Sense Computing U de Roy is + + align:start position:0% +um Common Sense Computing U de Roy is + + + align:start position:0% +um Common Sense Computing U de Roy is +collecting a huge amount of data but I'm + + align:start position:0% +collecting a huge amount of data but I'm + + + align:start position:0% +collecting a huge amount of data but I'm +not sure it's so organized as this oh + + align:start position:0% +not sure it's so organized as this oh + + + align:start position:0% +not sure it's so organized as this oh +the different thing is uh we have a you + + align:start position:0% +the different thing is uh we have a you + + + align:start position:0% +the different thing is uh we have a you +know increment we are our data is + + align:start position:0% +know increment we are our data is + + + align:start position:0% +know increment we are our data is +incremental so the uh so it's I I think + + align:start position:0% +incremental so the uh so it's I I think + + + align:start position:0% +incremental so the uh so it's I I think +it's a slightly different the boy uh uh + + align:start position:0% +it's a slightly different the boy uh uh + + + align:start position:0% +it's a slightly different the boy uh uh +was has been doing a good research for + + align:start position:0% +was has been doing a good research for + + + align:start position:0% +was has been doing a good research for +the very the um theep model of the the + + align:start position:0% +the very the um theep model of the the + + + align:start position:0% +the very the um theep model of the the +speech and language development that but + + align:start position:0% +speech and language development that but + + + align:start position:0% +speech and language development that but +our data is a multimodel including + + align:start position:0% +our data is a multimodel including + + + align:start position:0% +our data is a multimodel including +gestures for for instance at the + + align:start position:0% +gestures for for instance at the + + + align:start position:0% +gestures for for instance at the +beginning um just a behavior then the + + align:start position:0% +beginning um just a behavior then the + + + align:start position:0% +beginning um just a behavior then the +the communications is not um the um is + + align:start position:0% +the communications is not um the um is + + + align:start position:0% +the communications is not um the um is +uh useful then the behaviors changes to + + align:start position:0% +uh useful then the behaviors changes to + + + align:start position:0% +uh useful then the behaviors changes to +the + + align:start position:0% +the + + + align:start position:0% +the +gestures so um some symbolic meaning + + align:start position:0% +gestures so um some symbolic meaning + + + align:start position:0% +gestures so um some symbolic meaning +appears + + align:start position:0% +appears + + + align:start position:0% +appears +so our research is a um + + align:start position:0% +so our research is a um + + + align:start position:0% +so our research is a um +um um language development and uh just + + align:start position:0% +um um language development and uh just + + + align:start position:0% +um um language development and uh just +as + + align:start position:0% +as + + + align:start position:0% +as +development yeah if there's just one + + align:start position:0% +development yeah if there's just one + + + align:start position:0% +development yeah if there's just one +child you can't get all that yeah + + align:start position:0% +child you can't get all that yeah + + + align:start position:0% +child you can't get all that yeah +especially the um my colleague kirama he + + align:start position:0% +especially the um my colleague kirama he + + + align:start position:0% +especially the um my colleague kirama he +has a um two months old baby yes so uh + + align:start position:0% +has a um two months old baby yes so uh + + + align:start position:0% +has a um two months old baby yes so uh +it's good and the opportunity for + + align:start position:0% +it's good and the opportunity for + + + align:start position:0% +it's good and the opportunity for +him to observe the the + + align:start position:0% +him to observe the the + + + align:start position:0% +him to observe the the +babye babysitting + + align:start position:0% + + + + align:start position:0% + +yeah so U sorry um um um this evening um + + align:start position:0% +yeah so U sorry um um um this evening um + + + align:start position:0% +yeah so U sorry um um um this evening um +our computer doesn't work well thank you + + align:start position:0% +our computer doesn't work well thank you + + + align:start position:0% +our computer doesn't work well thank you +thank you very much for + + align:start position:0% +thank you very much for + + + align:start position:0% +thank you very much for +attentions + + align:start position:0% +attentions + + + align:start position:0% +attentions +yeah facts we've been able to collect so + + align:start position:0% +yeah facts we've been able to collect so + + + align:start position:0% +yeah facts we've been able to collect so +far those first months sorry how how + + align:start position:0% +far those first months sorry how how + + + align:start position:0% +far those first months sorry how how +manys Common Sense facts have you've + + align:start position:0% +manys Common Sense facts have you've + + + align:start position:0% +manys Common Sense facts have you've +been able to collect uhuh it's how to + + align:start position:0% +been able to collect uhuh it's how to + + + align:start position:0% +been able to collect uhuh it's how to +the um the + + align:start position:0% +the um the + + + align:start position:0% +the um the +count because uh uh um as I mentioned + + align:start position:0% +count because uh uh um as I mentioned + + + align:start position:0% +count because uh uh um as I mentioned +the multi um model infant Behavior + + align:start position:0% +the multi um model infant Behavior + + + align:start position:0% +the multi um model infant Behavior +Corpus the copass means the collecting + + align:start position:0% +Corpus the copass means the collecting + + + align:start position:0% +Corpus the copass means the collecting +video and audio data and annot with + + align:start position:0% +video and audio data and annot with + + + align:start position:0% +video and audio data and annot with +annotation annotation is a natural + + align:start position:0% +annotation annotation is a natural + + + align:start position:0% +annotation annotation is a natural +language and also the uh the some sort + + align:start position:0% +language and also the uh the some sort + + + align:start position:0% +language and also the uh the some sort +of knowledge representation language + + align:start position:0% + + + + align:start position:0% + +so yeah so the huge amount of data and + + align:start position:0% +so yeah so the huge amount of data and + + + align:start position:0% +so yeah so the huge amount of data and +uh we are the the changing the + + align:start position:0% +uh we are the the changing the + + + align:start position:0% +uh we are the the changing the +representation that you know our + + align:start position:0% +representation that you know our + + + align:start position:0% +representation that you know our +representations are evolving + + align:start position:0% + + + + align:start position:0% + +have any of + + align:start position:0% +have any of + + + align:start position:0% +have any of +you try to analyze what a child is + + align:start position:0% + + + + align:start position:0% + +doing of course no one really knows how + + align:start position:0% +doing of course no one really knows how + + + align:start position:0% +doing of course no one really knows how +you so who do you have + + align:start position:0% + + + + align:start position:0% + +annota how many people are oh the trying + + align:start position:0% +annota how many people are oh the trying + + + align:start position:0% +annota how many people are oh the trying +to describe basically the the graduate + + align:start position:0% +to describe basically the the graduate + + + align:start position:0% +to describe basically the the graduate +students and uh for the the conference + + align:start position:0% +students and uh for the the conference + + + align:start position:0% +students and uh for the the conference +the um about 10 mhm the people join the + + align:start position:0% +the um about 10 mhm the people join the + + + align:start position:0% +the um about 10 mhm the people join the +um like uh you know the U medical + + align:start position:0% +um like uh you know the U medical + + + align:start position:0% +um like uh you know the U medical +doctors have a conference yes so you + + align:start position:0% +doctors have a conference yes so you + + + align:start position:0% +doctors have a conference yes so you +have Conference of child yeah interest + + align:start position:0% +have Conference of child yeah interest + + + align:start position:0% +have Conference of child yeah interest +yeah and also sometimes the + + align:start position:0% +yeah and also sometimes the + + + align:start position:0% +yeah and also sometimes the +parents + + align:start position:0% +parents + + + align:start position:0% +parents +collabora I wonder if it be any use to + + align:start position:0% +collabora I wonder if it be any use to + + + align:start position:0% +collabora I wonder if it be any use to +try to get volunteers toate + + align:start position:0% +try to get volunteers toate + + + align:start position:0% +try to get volunteers toate +have to learn your way of describing + + align:start position:0% +have to learn your way of describing + + + align:start position:0% +have to learn your way of describing +things yeah um our system um can be used + + align:start position:0% +things yeah um our system um can be used + + + align:start position:0% +things yeah um our system um can be used +a web based system so you can join + + align:start position:0% + + + + align:start position:0% + +us but everybody would use a different + + align:start position:0% + + + + align:start position:0% + +language yeah U as far as the um the + + align:start position:0% +language yeah U as far as the um the + + + align:start position:0% +language yeah U as far as the um the +audio and video + + align:start position:0% +audio and video + + + align:start position:0% +audio and video +data it's the r data + + align:start position:0% +data it's the r data + + + align:start position:0% +data it's the r data +so in ph's laboratory which + + align:start position:0% +so in ph's laboratory which + + + align:start position:0% +so in ph's laboratory which +I guess closed in + + align:start position:0% +I guess closed in + + + align:start position:0% +I guess closed in +around the late + + align:start position:0% +around the late + + + align:start position:0% +around the late +1970s in Geneva there + + align:start position:0% +1970s in Geneva there + + + align:start position:0% +1970s in Geneva there +were many wonderful experiments it was a + + align:start position:0% +were many wonderful experiments it was a + + + align:start position:0% +were many wonderful experiments it was a +small lab I think it had about 8 or 10 + + align:start position:0% +small lab I think it had about 8 or 10 + + + align:start position:0% +small lab I think it had about 8 or 10 +people uh + + align:start position:0% +people uh + + + align:start position:0% +people uh +and there were long studies watching one + + align:start position:0% +and there were long studies watching one + + + align:start position:0% +and there were long studies watching one +child learn to build things with + + align:start position:0% + + + + align:start position:0% + +blocks I knew I knew one of the + + align:start position:0% +blocks I knew I knew one of the + + + align:start position:0% +blocks I knew I knew one of the +researchers I'm looking for two + + align:start position:0% +researchers I'm looking for two + + + align:start position:0% +researchers I'm looking for two +blocks but uh and that I'll names again + + align:start position:0% +blocks but uh and that I'll names again + + + align:start position:0% +blocks but uh and that I'll names again +uh she did experiments where uh the + + align:start position:0% +uh she did experiments where uh the + + + align:start position:0% +uh she did experiments where uh the +child uh had seen someone else build a + + align:start position:0% +child uh had seen someone else build a + + + align:start position:0% +child uh had seen someone else build a +t-shape just just a thing like + + align:start position:0% +t-shape just just a thing like + + + align:start position:0% +t-shape just just a thing like +that + + align:start position:0% +that + + + align:start position:0% +that +Sor and + + align:start position:0% +Sor and + + + align:start position:0% +Sor and +uh so after a while all children learned + + align:start position:0% +uh so after a while all children learned + + + align:start position:0% +uh so after a while all children learned +that um if you have the vertical block + + align:start position:0% +that um if you have the vertical block + + + align:start position:0% +that um if you have the vertical block +you should put the long horizontal block + + align:start position:0% +you should put the long horizontal block + + + align:start position:0% +you should put the long horizontal block +around in the + + align:start position:0% +around in the + + + align:start position:0% +around in the +middle and + + align:start position:0% + + + + align:start position:0% + +uh I'm blocked on the name of the + + align:start position:0% +uh I'm blocked on the name of the + + + align:start position:0% +uh I'm blocked on the name of the +experimenter so she made a block that uh + + align:start position:0% +experimenter so she made a block that uh + + + align:start position:0% +experimenter so she made a block that uh +like a loaded dice uh she drilled a + + align:start position:0% +like a loaded dice uh she drilled a + + + align:start position:0% +like a loaded dice uh she drilled a +little hole and put a lead weight in one + + align:start position:0% +little hole and put a lead weight in one + + + align:start position:0% +little hole and put a lead weight in one +end covered it up and varnished it so + + align:start position:0% +end covered it up and varnished it so + + + align:start position:0% +end covered it up and varnished it so +you couldn't tell and so then the block + + align:start position:0% +you couldn't tell and so then the block + + + align:start position:0% +you couldn't tell and so then the block +would have to be offset + + align:start position:0% +would have to be offset + + + align:start position:0% +would have to be offset +so what was interesting is that + + align:start position:0% + + + + align:start position:0% + +uh the three-year-olds had a lot of + + align:start position:0% +uh the three-year-olds had a lot of + + + align:start position:0% +uh the three-year-olds had a lot of +trouble with + + align:start position:0% +trouble with + + + align:start position:0% +trouble with +that and uh they would keep putting it + + align:start position:0% +that and uh they would keep putting it + + + align:start position:0% +that and uh they would keep putting it +in in the center it would fall over and + + align:start position:0% +in in the center it would fall over and + + + align:start position:0% +in in the center it would fall over and +they wouldn't know what to do and then + + align:start position:0% +they wouldn't know what to do and then + + + align:start position:0% +they wouldn't know what to do and then +slightly older children would realize + + align:start position:0% +slightly older children would realize + + + align:start position:0% +slightly older children would realize +there was something wrong with the block + + align:start position:0% +there was something wrong with the block + + + align:start position:0% +there was something wrong with the block +and they would just push it until it + + align:start position:0% +and they would just push it until it + + + align:start position:0% +and they would just push it until it +balanced nicely even though it was off + + align:start position:0% +balanced nicely even though it was off + + + align:start position:0% +balanced nicely even though it was off +center it was sort of unusual uh that + + align:start position:0% +center it was sort of unusual uh that + + + align:start position:0% +center it was sort of unusual uh that +developmental scenario because then a + + align:start position:0% +developmental scenario because then a + + + align:start position:0% +developmental scenario because then a +slightly older child uh would be as bad + + align:start position:0% +slightly older child uh would be as bad + + + align:start position:0% +slightly older child uh would be as bad +as the the + + align:start position:0% +as the the + + + align:start position:0% +as the the +three-year-old because the older child + + align:start position:0% +three-year-old because the older child + + + align:start position:0% +three-year-old because the older child +knew that it had to be + + align:start position:0% +knew that it had to be + + + align:start position:0% +knew that it had to be +symmetrical didn't know the imbalance + + align:start position:0% +symmetrical didn't know the imbalance + + + align:start position:0% +symmetrical didn't know the imbalance +was very uh very small so the older + + align:start position:0% +was very uh very small so the older + + + align:start position:0% +was very uh very small so the older +child persisted much longer in trying to + + align:start position:0% +child persisted much longer in trying to + + + align:start position:0% +child persisted much longer in trying to +make it centered because he knew it had + + align:start position:0% +make it centered because he knew it had + + + align:start position:0% +make it centered because he knew it had +to be centered so you had a + + align:start position:0% +to be centered so you had a + + + align:start position:0% +to be centered so you had a +developmental curve like that instead of + + align:start position:0% +developmental curve like that instead of + + + align:start position:0% +developmental curve like that instead of +of the + + align:start position:0% +of the + + + align:start position:0% +of the +usual uh getting better and + + align:start position:0% +usual uh getting better and + + + align:start position:0% +usual uh getting better and +better and then of course a yet older + + align:start position:0% +better and then of course a yet older + + + align:start position:0% +better and then of course a yet older +child would quickly say Well it must + + align:start position:0% +child would quickly say Well it must + + + align:start position:0% +child would quickly say Well it must +have a weight in this end so uh they'd + + align:start position:0% +have a weight in this end so uh they'd + + + align:start position:0% +have a weight in this end so uh they'd +be happy at the first try + + align:start position:0% +be happy at the first try + + + align:start position:0% +be happy at the first try +because it wouldn't have fallen over in + + align:start position:0% +because it wouldn't have fallen over in + + + align:start position:0% +because it wouldn't have fallen over in +the middle if it + + align:start position:0% +the middle if it + + + align:start position:0% +the middle if it +didn't so you could see I mean you're + + align:start position:0% +didn't so you could see I mean you're + + + align:start position:0% +didn't so you could see I mean you're +I'm just inferring all that from just + + align:start position:0% +I'm just inferring all that from just + + + align:start position:0% +I'm just inferring all that from just +seeing + + align:start position:0% +seeing + + + align:start position:0% +seeing +the seeing what happened and you're + + align:start position:0% +the seeing what happened and you're + + + align:start position:0% +the seeing what happened and you're +guessing that why the really old child + + align:start position:0% +guessing that why the really old child + + + align:start position:0% +guessing that why the really old child +instantly makes the Right theory and uh + + align:start position:0% +instantly makes the Right theory and uh + + + align:start position:0% +instantly makes the Right theory and uh +doesn't mind that it's + + align:start position:0% + + + + align:start position:0% + +unsymmetrical so until we can actually + + align:start position:0% +unsymmetrical so until we can actually + + + align:start position:0% +unsymmetrical so until we can actually +look into their brain we just have to + + align:start position:0% +look into their brain we just have to + + + align:start position:0% +look into their brain we just have to +guess how + + align:start position:0% +guess how + + + align:start position:0% +guess how +to what's going on + + align:start position:0% +to what's going on + + + align:start position:0% +to what's going on +there but if P hadn't done the + + align:start position:0% +there but if P hadn't done the + + + align:start position:0% +there but if P hadn't done the +experiments maybe the question would + + align:start position:0% +experiments maybe the question would + + + align:start position:0% +experiments maybe the question would +never + + align:start position:0% +never + + + align:start position:0% +never +arise uh in fact I did some experiments + + align:start position:0% +arise uh in fact I did some experiments + + + align:start position:0% +arise uh in fact I did some experiments +after that uh making complicated things + + align:start position:0% +after that uh making complicated things + + + align:start position:0% +after that uh making complicated things +and asking children where the center + + align:start position:0% +and asking children where the center + + + align:start position:0% +and asking children where the center +was and it wasn't a scientific study but + + align:start position:0% +was and it wasn't a scientific study but + + + align:start position:0% +was and it wasn't a scientific study but +it was + + align:start position:0% +it was + + + align:start position:0% +it was +amazing uh even very young + + align:start position:0% +amazing uh even very young + + + align:start position:0% +amazing uh even very young +children would instantly find this the + + align:start position:0% +children would instantly find this the + + + align:start position:0% +children would instantly find this the +center of an object once once they knew + + align:start position:0% +center of an object once once they knew + + + align:start position:0% +center of an object once once they knew +I was looking for even if it were + + align:start position:0% +I was looking for even if it were + + + align:start position:0% +I was looking for even if it were +complicated Swirls and things I have no + + align:start position:0% +complicated Swirls and things I have no + + + align:start position:0% +complicated Swirls and things I have no +idea how they do it + + align:start position:0% + + + + align:start position:0% + +what do you think about more more + + align:start position:0% +what do you think about more more + + + align:start position:0% +what do you think about more more +research the the brain research using + + align:start position:0% +research the the brain research using + + + align:start position:0% +research the the brain research using +MRI or well every clue gives + + align:start position:0% +MRI or well every clue gives + + + align:start position:0% +MRI or well every clue gives +you I think once you have a a scanner + + align:start position:0% +you I think once you have a a scanner + + + align:start position:0% +you I think once you have a a scanner +that's not interfering with the child + + align:start position:0% +that's not interfering with the child + + + align:start position:0% +that's not interfering with the child +then then you take all your theories + + align:start position:0% +then then you take all your theories + + + align:start position:0% +then then you take all your theories +that came from this and maybe in a much + + align:start position:0% +that came from this and maybe in a much + + + align:start position:0% +that came from this and maybe in a much +shorter time you can say well uh we can + + align:start position:0% +shorter time you can say well uh we can + + + align:start position:0% +shorter time you can say well uh we can +throw half those theories out right away + + align:start position:0% +throw half those theories out right away + + + align:start position:0% +throw half those theories out right away +because of something we saw in the + + align:start position:0% +because of something we saw in the + + + align:start position:0% +because of something we saw in the +brain nobody knows what'll happen if you + + align:start position:0% +brain nobody knows what'll happen if you + + + align:start position:0% +brain nobody knows what'll happen if you +get if we can get fast high resolution + + align:start position:0% +get if we can get fast high resolution + + + align:start position:0% +get if we can get fast high resolution +pictures of the brain + + align:start position:0% +pictures of the brain + + + align:start position:0% +pictures of the brain +then then we might as well start over + + align:start position:0% +then then we might as well start over + + + align:start position:0% +then then we might as well start over +with everything + + align:start position:0% +with everything + + + align:start position:0% +with everything +because generally the brain scientist + + align:start position:0% +because generally the brain scientist + + + align:start position:0% +because generally the brain scientist +doesn't have any interest the high level + + align:start position:0% +doesn't have any interest the high level + + + align:start position:0% +doesn't have any interest the high level +theor well they sort of have very high + + align:start position:0% +theor well they sort of have very high + + + align:start position:0% +theor well they sort of have very high +level theories from Clinical mhm and + + align:start position:0% +level theories from Clinical mhm and + + + align:start position:0% +level theories from Clinical mhm and +very low-level theories from from uh + + align:start position:0% +very low-level theories from from uh + + + align:start position:0% +very low-level theories from from uh +looking at + + align:start position:0% +looking at + + + align:start position:0% +looking at +cells and uh they're trying to find + + align:start position:0% +cells and uh they're trying to find + + + align:start position:0% +cells and uh they're trying to find +theories in between but since they as + + align:start position:0% +theories in between but since they as + + + align:start position:0% +theories in between but since they as +far as I can see what you have to do is + + align:start position:0% +far as I can see what you have to do is + + + align:start position:0% +far as I can see what you have to do is +take the AI thing and work down because + + align:start position:0% +take the AI thing and work down because + + + align:start position:0% +take the AI thing and work down because +otherwise you wouldn't guess what to + + align:start position:0% +otherwise you wouldn't guess what to + + + align:start position:0% +otherwise you wouldn't guess what to +look + + align:start position:0% +look + + + align:start position:0% +look +for like in in uh there's this old idea + + align:start position:0% +for like in in uh there's this old idea + + + align:start position:0% +for like in in uh there's this old idea +uh that I call a Difference + + align:start position:0% +uh that I call a Difference + + + align:start position:0% +uh that I call a Difference +Engine which I got from new Simon it + + align:start position:0% +Engine which I got from new Simon it + + + align:start position:0% +Engine which I got from new Simon it +says uh if you you have a goal uh then + + align:start position:0% +says uh if you you have a goal uh then + + + align:start position:0% +says uh if you you have a goal uh then +the simplest explanation is the old + + align:start position:0% +the simplest explanation is the old + + + align:start position:0% +the simplest explanation is the old +cybernetic idea there's something that + + align:start position:0% +cybernetic idea there's something that + + + align:start position:0% +cybernetic idea there's something that +has a representation of uh the + + align:start position:0% +has a representation of uh the + + + align:start position:0% +has a representation of uh the +properties that you want and there's + + align:start position:0% +properties that you want and there's + + + align:start position:0% +properties that you want and there's +something else that is making a + + align:start position:0% +something else that is making a + + + align:start position:0% +something else that is making a +representation of what it observes and + + align:start position:0% +representation of what it observes and + + + align:start position:0% +representation of what it observes and +there has to be something to see what's + + align:start position:0% +there has to be something to see what's + + + align:start position:0% +there has to be something to see what's +the difference between those lists and + + align:start position:0% +the difference between those lists and + + + align:start position:0% +the difference between those lists and +then there has to be something to say + + align:start position:0% +then there has to be something to say + + + align:start position:0% +then there has to be something to say +well which of those features should I + + align:start position:0% +well which of those features should I + + + align:start position:0% +well which of those features should I +try to reduce + + align:start position:0% +try to reduce + + + align:start position:0% +try to reduce +next and uh unless you have a theory + + align:start position:0% +next and uh unless you have a theory + + + align:start position:0% +next and uh unless you have a theory +like that that you you wouldn't know + + align:start position:0% +like that that you you wouldn't know + + + align:start position:0% +like that that you you wouldn't know +what to look + + align:start position:0% +what to look + + + align:start position:0% +what to look +for + + align:start position:0% + + + + align:start position:0% + +and I'm sure eventually somebody will + + align:start position:0% +and I'm sure eventually somebody will + + + align:start position:0% +and I'm sure eventually somebody will +think of two or three other ideas for + + align:start position:0% +think of two or three other ideas for + + + align:start position:0% +think of two or three other ideas for +representing goals but but uh this is + + align:start position:0% +representing goals but but uh this is + + + align:start position:0% +representing goals but but uh this is +the only one that's ever worked in in + + align:start position:0% + + + + align:start position:0% + +programs there's series of + + align:start position:0% +programs there's series of + + + align:start position:0% +programs there's series of +papers right around 1960 by Allan Newell + + align:start position:0% +papers right around 1960 by Allan Newell + + + align:start position:0% +papers right around 1960 by Allan Newell +and Herbert Simon where they made + + align:start position:0% +and Herbert Simon where they made + + + align:start position:0% +and Herbert Simon where they made +programs that uh solved some problems by + + align:start position:0% +programs that uh solved some problems by + + + align:start position:0% +programs that uh solved some problems by +formulating things as goals and uh + + align:start position:0% +formulating things as goals and uh + + + align:start position:0% +formulating things as goals and uh +processes that would look for + + align:start position:0% +processes that would look for + + + align:start position:0% +processes that would look for +differences between situations and try + + align:start position:0% +differences between situations and try + + + align:start position:0% +differences between situations and try +to remove them it's sort of + + align:start position:0% +to remove them it's sort of + + + align:start position:0% +to remove them it's sort of +obvious but + + align:start position:0% +obvious but + + + align:start position:0% +obvious but +uh but uh I haven't seen that idea + + align:start position:0% +uh but uh I haven't seen that idea + + + align:start position:0% +uh but uh I haven't seen that idea +lately it sort of died out for some + + align:start position:0% +lately it sort of died out for some + + + align:start position:0% +lately it sort of died out for some +reason + + align:start position:0% + + + + align:start position:0% + +time's up but if anybody has + + align:start position:0% + + + + align:start position:0% + +a thanks yoi CH + + align:start position:0% +a thanks yoi CH + + + align:start position:0% +a thanks yoi CH +that's have to come back in a year or + + align:start position:0% +that's have to come back in a year or + + + align:start position:0% +that's have to come back in a year or +two and see what the five-year-olds are + + align:start position:0% +two and see what the five-year-olds are + + + align:start position:0% +two and see what the five-year-olds are +doing well you when do they go to school + + align:start position:0% +doing well you when do they go to school + + + align:start position:0% +doing well you when do they go to school +and then you lose + + align:start position:0% +and then you lose + + + align:start position:0% +and then you lose +them six six year old uhhuh plenty of + + align:start position:0% +them six six year old uhhuh plenty of + + + align:start position:0% +them six six year old uhhuh plenty of +time then uh weend Saturday on + + align:start position:0% +time then uh weend Saturday on + + + align:start position:0% +time then uh weend Saturday on +Sundays but in any case I think if you + + align:start position:0% +Sundays but in any case I think if you + + + align:start position:0% +Sundays but in any case I think if you +knew how a 5-year-old worked you would + + align:start position:0% +knew how a 5-year-old worked you would + + + align:start position:0% +knew how a 5-year-old worked you would +be almost all the way + + align:start position:0% +be almost all the way + + + align:start position:0% +be almost all the way +home + + align:start position:0% +home + + + align:start position:0% +home +so if you take all the things robots can + + align:start position:0% +so if you take all the things robots can + + + align:start position:0% +so if you take all the things robots can +do today + + align:start position:0% +do today + + + align:start position:0% +do today +uh that includes almost none of what a + + align:start position:0% +uh that includes almost none of what a + + + align:start position:0% +uh that includes almost none of what a +five-year-old can + + align:start position:0% + + + + align:start position:0% + +do in fact why do we need school + + align:start position:0% +do in fact why do we need school + + + align:start position:0% +do in fact why do we need school +pleas \ No newline at end of file diff --git a/klPt8DrL5tc.txt b/klPt8DrL5tc.txt new file mode 100644 index 0000000000000000000000000000000000000000..378a150ba0e276248ab174d8f951474c9d23fb2f --- /dev/null +++ b/klPt8DrL5tc.txt @@ -0,0 +1,1347 @@ +align:start position:0% + +my name is Devon Neary I'm the cleaning + + align:start position:0% +my name is Devon Neary I'm the cleaning + + + align:start position:0% +my name is Devon Neary I'm the cleaning +the outreach manager here at the cma as + + align:start position:0% +the outreach manager here at the cma as + + + align:start position:0% +the outreach manager here at the cma as +you all know our members across the + + align:start position:0% +you all know our members across the + + + align:start position:0% +you all know our members across the +country face constant opposition from + + align:start position:0% +country face constant opposition from + + + align:start position:0% +country face constant opposition from +environmental groups I'm here today to + + align:start position:0% +environmental groups I'm here today to + + + align:start position:0% +environmental groups I'm here today to +propose some solutions for working with + + align:start position:0% +propose some solutions for working with + + + align:start position:0% +propose some solutions for working with +these groups right hence then our most + + align:start position:0% +these groups right hence then our most + + + align:start position:0% +these groups right hence then our most +recent conflict involved an + + align:start position:0% +recent conflict involved an + + + align:start position:0% +recent conflict involved an +environmental group trying to block the + + align:start position:0% +environmental group trying to block the + + + align:start position:0% +environmental group trying to block the +expansion of our Southwest computer chip + + align:start position:0% +expansion of our Southwest computer chip + + + align:start position:0% +expansion of our Southwest computer chip +factory on the grounds that pollution is + + align:start position:0% +factory on the grounds that pollution is + + + align:start position:0% +factory on the grounds that pollution is +causing a spike in local cancer rates so + + align:start position:0% +causing a spike in local cancer rates so + + + align:start position:0% +causing a spike in local cancer rates so +what's our goal be in designing a + + align:start position:0% +what's our goal be in designing a + + + align:start position:0% +what's our goal be in designing a +working plan with this environmental + + align:start position:0% +working plan with this environmental + + + align:start position:0% +working plan with this environmental +group I propose a strategy that is + + align:start position:0% +group I propose a strategy that is + + + align:start position:0% +group I propose a strategy that is +different from how the CMA usually + + align:start position:0% +different from how the CMA usually + + + align:start position:0% +different from how the CMA usually +conducts business I propose me sit down + + align:start position:0% +conducts business I propose me sit down + + + align:start position:0% +conducts business I propose me sit down +in a mediated negotiation with the + + align:start position:0% +in a mediated negotiation with the + + + align:start position:0% +in a mediated negotiation with the +environmental groups and explain our + + align:start position:0% +environmental groups and explain our + + + align:start position:0% +environmental groups and explain our +side of the issue allow them to explain + + align:start position:0% +side of the issue allow them to explain + + + align:start position:0% +side of the issue allow them to explain +their side of the issue and find a + + align:start position:0% +their side of the issue and find a + + + align:start position:0% +their side of the issue and find a +consensus for moving forward that + + align:start position:0% +consensus for moving forward that + + + align:start position:0% +consensus for moving forward that +enables both sides to achieve their + + align:start position:0% +enables both sides to achieve their + + + align:start position:0% +enables both sides to achieve their +long-term aims given the constraints of + + align:start position:0% +long-term aims given the constraints of + + + align:start position:0% +long-term aims given the constraints of +reality we want to open up a space to + + align:start position:0% +reality we want to open up a space to + + + align:start position:0% +reality we want to open up a space to +collaborate and brainstorm non-binding + + align:start position:0% +collaborate and brainstorm non-binding + + + align:start position:0% +collaborate and brainstorm non-binding +options as a means of moving towards a + + align:start position:0% +options as a means of moving towards a + + + align:start position:0% +options as a means of moving towards a +binding agreement why should this be our + + align:start position:0% +binding agreement why should this be our + + + align:start position:0% +binding agreement why should this be our +goal environmental groups pressure us + + align:start position:0% +goal environmental groups pressure us + + + align:start position:0% +goal environmental groups pressure us +and attempt to block us at our sites + + align:start position:0% +and attempt to block us at our sites + + + align:start position:0% +and attempt to block us at our sites +throughout the country these disputes + + align:start position:0% +throughout the country these disputes + + + align:start position:0% +throughout the country these disputes +have not improved over the last few + + align:start position:0% +have not improved over the last few + + + align:start position:0% +have not improved over the last few +decades and it's time for a new approach + + align:start position:0% +decades and it's time for a new approach + + + align:start position:0% +decades and it's time for a new approach +to make sure our projects progressed + + align:start position:0% +to make sure our projects progressed + + + align:start position:0% +to make sure our projects progressed +according to time and financial + + align:start position:0% +according to time and financial + + + align:start position:0% +according to time and financial +constraints my research on this issue + + align:start position:0% +constraints my research on this issue + + + align:start position:0% +constraints my research on this issue +supports the idea that a consensus + + align:start position:0% +supports the idea that a consensus + + + align:start position:0% +supports the idea that a consensus +building approach can improve outcomes + + align:start position:0% +building approach can improve outcomes + + + align:start position:0% +building approach can improve outcomes +for all parties just for a little bit of + + align:start position:0% +for all parties just for a little bit of + + + align:start position:0% +for all parties just for a little bit of +context in reality our partners in the + + align:start position:0% +context in reality our partners in the + + + align:start position:0% +context in reality our partners in the +environments organization do not have a + + align:start position:0% +environments organization do not have a + + + align:start position:0% +environments organization do not have a +lot of legal ground to stand on proving + + align:start position:0% +lot of legal ground to stand on proving + + + align:start position:0% +lot of legal ground to stand on proving +the cause of a specific cancer in a + + align:start position:0% +the cause of a specific cancer in a + + + align:start position:0% +the cause of a specific cancer in a +specific individual and tying it to a + + align:start position:0% +specific individual and tying it to a + + + align:start position:0% +specific individual and tying it to a +specific chemical that came out of our + + align:start position:0% +specific chemical that came out of our + + + align:start position:0% +specific chemical that came out of our +chip plant on a specific day is very + + align:start position:0% +chip plant on a specific day is very + + + align:start position:0% +chip plant on a specific day is very +challenging and costly in a courtroom we + + align:start position:0% +challenging and costly in a courtroom we + + + align:start position:0% +challenging and costly in a courtroom we +can gently remind environmentalists that + + align:start position:0% +can gently remind environmentalists that + + + align:start position:0% +can gently remind environmentalists that +court is expensive adversarial and often + + align:start position:0% +court is expensive adversarial and often + + + align:start position:0% +court is expensive adversarial and often +drawn-out + + align:start position:0% +drawn-out + + + align:start position:0% +drawn-out +similarly our funding and legal + + align:start position:0% +similarly our funding and legal + + + align:start position:0% +similarly our funding and legal +capabilities will defeat theirs in + + align:start position:0% +capabilities will defeat theirs in + + + align:start position:0% +capabilities will defeat theirs in +addition in times of economic duress and + + align:start position:0% +addition in times of economic duress and + + + align:start position:0% +addition in times of economic duress and +uncertainty local authorities are going + + align:start position:0% +uncertainty local authorities are going + + + align:start position:0% +uncertainty local authorities are going +to make way for our great industry to + + align:start position:0% +to make way for our great industry to + + + align:start position:0% +to make way for our great industry to +create jobs and capital + + align:start position:0% +create jobs and capital + + + align:start position:0% +create jobs and capital +so in some sense there's no need for us + + align:start position:0% +so in some sense there's no need for us + + + align:start position:0% +so in some sense there's no need for us +to engage with the environmentalists + + align:start position:0% +to engage with the environmentalists + + + align:start position:0% +to engage with the environmentalists +without the negotiation we'll probably + + align:start position:0% +without the negotiation we'll probably + + + align:start position:0% +without the negotiation we'll probably +still get our expansion however what I + + align:start position:0% +still get our expansion however what I + + + align:start position:0% +still get our expansion however what I +want to point out is that we can do + + align:start position:0% +want to point out is that we can do + + + align:start position:0% +want to point out is that we can do +better than that + + align:start position:0% +better than that + + + align:start position:0% +better than that +the negotiation we can improve our + + align:start position:0% +the negotiation we can improve our + + + align:start position:0% +the negotiation we can improve our +relationships with the environmentalists + + align:start position:0% +relationships with the environmentalists + + + align:start position:0% +relationships with the environmentalists +and we can make it easier and less + + align:start position:0% +and we can make it easier and less + + + align:start position:0% +and we can make it easier and less +costly to do business in the future I + + align:start position:0% +costly to do business in the future I + + + align:start position:0% +costly to do business in the future I +know many of you probably have some + + align:start position:0% +know many of you probably have some + + + align:start position:0% +know many of you probably have some +hesitations about this perhaps you feel + + align:start position:0% +hesitations about this perhaps you feel + + + align:start position:0% +hesitations about this perhaps you feel +a fear of the unknown a fear that the + + align:start position:0% +a fear of the unknown a fear that the + + + align:start position:0% +a fear of the unknown a fear that the +process will fail or fear that the + + align:start position:0% +process will fail or fear that the + + + align:start position:0% +process will fail or fear that the +negotiation will be slow and costly but + + align:start position:0% +negotiation will be slow and costly but + + + align:start position:0% +negotiation will be slow and costly but +remember we're investing for long term + + align:start position:0% +remember we're investing for long term + + + align:start position:0% +remember we're investing for long term +gains in our relationships with + + align:start position:0% +gains in our relationships with + + + align:start position:0% +gains in our relationships with +surrounding communities I understands is + + align:start position:0% +surrounding communities I understands is + + + align:start position:0% +surrounding communities I understands is +atypical for our powerful industry and + + align:start position:0% +atypical for our powerful industry and + + + align:start position:0% +atypical for our powerful industry and +there will be challenges as the views of + + align:start position:0% +there will be challenges as the views of + + + align:start position:0% +there will be challenges as the views of +the CMA and the views of the + + align:start position:0% +the CMA and the views of the + + + align:start position:0% +the CMA and the views of the +environmental groups differ radically + + align:start position:0% +environmental groups differ radically + + + align:start position:0% +environmental groups differ radically +the environmentalists may not be ready + + align:start position:0% +the environmentalists may not be ready + + + align:start position:0% +the environmentalists may not be ready +or willing to negotiate they may be + + align:start position:0% +or willing to negotiate they may be + + + align:start position:0% +or willing to negotiate they may be +intent on filing a lawsuit or they could + + align:start position:0% +intent on filing a lawsuit or they could + + + align:start position:0% +intent on filing a lawsuit or they could +draw out the negotiations in a + + align:start position:0% +draw out the negotiations in a + + + align:start position:0% +draw out the negotiations in a +disruptive manner their strategy is + + align:start position:0% +disruptive manner their strategy is + + + align:start position:0% +disruptive manner their strategy is +going to be to eliminate the earth their + + align:start position:0% +going to be to eliminate the earth their + + + align:start position:0% +going to be to eliminate the earth their +ultimate goal would probably be to + + align:start position:0% +ultimate goal would probably be to + + + align:start position:0% +ultimate goal would probably be to +eliminate art plan but this is not a + + align:start position:0% +eliminate art plan but this is not a + + + align:start position:0% +eliminate art plan but this is not a +realistic demand our plan is already + + align:start position:0% +realistic demand our plan is already + + + align:start position:0% +realistic demand our plan is already +they're not breeding well so eliminating + + align:start position:0% +they're not breeding well so eliminating + + + align:start position:0% +they're not breeding well so eliminating +the potential carcinogens is not a + + align:start position:0% +the potential carcinogens is not a + + + align:start position:0% +the potential carcinogens is not a +feasible option for them so what is the + + align:start position:0% +feasible option for them so what is the + + + align:start position:0% +feasible option for them so what is the +next next best option for the community + + align:start position:0% +next next best option for the community + + + align:start position:0% +next next best option for the community +our strategy is to think in terms what + + align:start position:0% +our strategy is to think in terms what + + + align:start position:0% +our strategy is to think in terms what +we can offer them to appease some of + + align:start position:0% +we can offer them to appease some of + + + align:start position:0% +we can offer them to appease some of +their concerns without giving up + + align:start position:0% +their concerns without giving up + + + align:start position:0% +their concerns without giving up +anything precious to us do they need + + align:start position:0% +anything precious to us do they need + + + align:start position:0% +anything precious to us do they need +health clinics in their community do + + align:start position:0% +health clinics in their community do + + + align:start position:0% +health clinics in their community do +they want a community buy out so they + + align:start position:0% +they want a community buy out so they + + + align:start position:0% +they want a community buy out so they +can relocate what they like a new nature + + align:start position:0% +can relocate what they like a new nature + + + align:start position:0% +can relocate what they like a new nature +preserve or funding for education for + + align:start position:0% +preserve or funding for education for + + + align:start position:0% +preserve or funding for education for +our part our members have to decide away + + align:start position:0% +our part our members have to decide away + + + align:start position:0% +our part our members have to decide away +from the table how much we are willing + + align:start position:0% +from the table how much we are willing + + + align:start position:0% +from the table how much we are willing +to give to smooth out these + + align:start position:0% +to give to smooth out these + + + align:start position:0% +to give to smooth out these +relationships and leverage these + + align:start position:0% +relationships and leverage these + + + align:start position:0% +relationships and leverage these +concessions and negotiations we need to + + align:start position:0% +concessions and negotiations we need to + + + align:start position:0% +concessions and negotiations we need to +find out what people on both sides are + + align:start position:0% +find out what people on both sides are + + + align:start position:0% +find out what people on both sides are +really willing to live with we can begin + + align:start position:0% +really willing to live with we can begin + + + align:start position:0% +really willing to live with we can begin +by addressing their environmental + + align:start position:0% +by addressing their environmental + + + align:start position:0% +by addressing their environmental +concerns talking about issues of leaks + + align:start position:0% +concerns talking about issues of leaks + + + align:start position:0% +concerns talking about issues of leaks +accidents the increased rates of cancer + + align:start position:0% +accidents the increased rates of cancer + + + align:start position:0% +accidents the increased rates of cancer +that they're observing how can you prove + + align:start position:0% +that they're observing how can you prove + + + align:start position:0% +that they're observing how can you prove +to them that we are in compliance of + + align:start position:0% +to them that we are in compliance of + + + align:start position:0% +to them that we are in compliance of +regulations and protecting the abutting + + align:start position:0% +regulations and protecting the abutting + + + align:start position:0% +regulations and protecting the abutting +communities we can also leverage what we + + align:start position:0% +communities we can also leverage what we + + + align:start position:0% +communities we can also leverage what we +do well for the community we create jobs + + align:start position:0% +do well for the community we create jobs + + + align:start position:0% +do well for the community we create jobs +we spur economic development we make + + align:start position:0% +we spur economic development we make + + + align:start position:0% +we spur economic development we make +philanthropic donations provide job + + align:start position:0% +philanthropic donations provide job + + + align:start position:0% +philanthropic donations provide job +training my job is to get people excited + + align:start position:0% +training my job is to get people excited + + + align:start position:0% +training my job is to get people excited +about chemical manufacturing and all the + + align:start position:0% +about chemical manufacturing and all the + + + align:start position:0% +about chemical manufacturing and all the +wonderful things we do for the country + + align:start position:0% +wonderful things we do for the country + + + align:start position:0% +wonderful things we do for the country +and for the world the chips + + align:start position:0% +and for the world the chips + + + align:start position:0% +and for the world the chips +manufacturing plant in question while + + align:start position:0% +manufacturing plant in question while + + + align:start position:0% +manufacturing plant in question while +may be causing some pollution is + + align:start position:0% +may be causing some pollution is + + + align:start position:0% +may be causing some pollution is +manufacturing computer chips used in a + + align:start position:0% +manufacturing computer chips used in a + + + align:start position:0% +manufacturing computer chips used in a +wide range of industries and clean + + align:start position:0% +wide range of industries and clean + + + align:start position:0% +wide range of industries and clean +defense medical research + + align:start position:0% +defense medical research + + + align:start position:0% +defense medical research +shishun and so on we believe that if + + align:start position:0% +shishun and so on we believe that if + + + align:start position:0% +shishun and so on we believe that if +residents realize the contribution we + + align:start position:0% +residents realize the contribution we + + + align:start position:0% +residents realize the contribution we +have for their community and for the + + align:start position:0% +have for their community and for the + + + align:start position:0% +have for their community and for the +country they'll be more amenable to + + align:start position:0% +country they'll be more amenable to + + + align:start position:0% +country they'll be more amenable to +negotiating with us so you want to focus + + align:start position:0% +negotiating with us so you want to focus + + + align:start position:0% +negotiating with us so you want to focus +on two principles we want to focus on + + align:start position:0% +on two principles we want to focus on + + + align:start position:0% +on two principles we want to focus on +maintaining relationships throughout you + + align:start position:0% +maintaining relationships throughout you + + + align:start position:0% +maintaining relationships throughout you +want to focus on mutual gains so we'll + + align:start position:0% +want to focus on mutual gains so we'll + + + align:start position:0% +want to focus on mutual gains so we'll +follow a process based on a research + + align:start position:0% +follow a process based on a research + + + align:start position:0% +follow a process based on a research +consensus building approach when we are + + align:start position:0% +consensus building approach when we are + + + align:start position:0% +consensus building approach when we are +a to negotiate and the environmentalists + + align:start position:0% +a to negotiate and the environmentalists + + + align:start position:0% +a to negotiate and the environmentalists +expressed that they already first we + + align:start position:0% +expressed that they already first we + + + align:start position:0% +expressed that they already first we +will convene and assign roles for + + align:start position:0% +will convene and assign roles for + + + align:start position:0% +will convene and assign roles for +example we need to identify a mediator + + align:start position:0% +example we need to identify a mediator + + + align:start position:0% +example we need to identify a mediator +the mediator will schedule and + + align:start position:0% +the mediator will schedule and + + + align:start position:0% +the mediator will schedule and +facilitate the meetings consult + + align:start position:0% +facilitate the meetings consult + + + align:start position:0% +facilitate the meetings consult +privately with groups and push us to + + align:start position:0% +privately with groups and push us to + + + align:start position:0% +privately with groups and push us to +build consensus we also want to focus on + + align:start position:0% +build consensus we also want to focus on + + + align:start position:0% +build consensus we also want to focus on +group problem solving how can we create + + align:start position:0% +group problem solving how can we create + + + align:start position:0% +group problem solving how can we create +value as a group by brainstorming + + align:start position:0% +value as a group by brainstorming + + + align:start position:0% +value as a group by brainstorming +different options together based on our + + align:start position:0% +different options together based on our + + + align:start position:0% +different options together based on our +interests and being creative we can + + align:start position:0% +interests and being creative we can + + + align:start position:0% +interests and being creative we can +present alternative designs we can + + align:start position:0% +present alternative designs we can + + + align:start position:0% +present alternative designs we can +expand the means of dealing with + + align:start position:0% +expand the means of dealing with + + + align:start position:0% +expand the means of dealing with +externalities and try to create + + align:start position:0% +externalities and try to create + + + align:start position:0% +externalities and try to create +different packages of benefits we can + + align:start position:0% +different packages of benefits we can + + + align:start position:0% +different packages of benefits we can +offer the community once we have created + + align:start position:0% +offer the community once we have created + + + align:start position:0% +offer the community once we have created +value we can talk about ways to + + align:start position:0% +value we can talk about ways to + + + align:start position:0% +value we can talk about ways to +distribute value to implement these + + align:start position:0% +distribute value to implement these + + + align:start position:0% +distribute value to implement these +goals and to hold parties accountable + + align:start position:0% +goals and to hold parties accountable + + + align:start position:0% +goals and to hold parties accountable +for their commitments so just to review + + align:start position:0% +for their commitments so just to review + + + align:start position:0% +for their commitments so just to review +the benefits of engaging in a successful + + align:start position:0% +the benefits of engaging in a successful + + + align:start position:0% +the benefits of engaging in a successful +negotiation for our company it's an + + align:start position:0% +negotiation for our company it's an + + + align:start position:0% +negotiation for our company it's an +opportunity to educate the community + + align:start position:0% +opportunity to educate the community + + + align:start position:0% +opportunity to educate the community +about our work and our constraints to + + align:start position:0% +about our work and our constraints to + + + align:start position:0% +about our work and our constraints to +gain some flexibility in when and how + + align:start position:0% +gain some flexibility in when and how + + + align:start position:0% +gain some flexibility in when and how +requirements are met and to smooth out + + align:start position:0% +requirements are met and to smooth out + + + align:start position:0% +requirements are met and to smooth out +these long-standing and disruptive + + align:start position:0% +these long-standing and disruptive + + + align:start position:0% +these long-standing and disruptive +conflicts with environmentalists with + + align:start position:0% +conflicts with environmentalists with + + + align:start position:0% +conflicts with environmentalists with +the environmentalists they can achieve + + align:start position:0% +the environmentalists they can achieve + + + align:start position:0% +the environmentalists they can achieve +better environmental gains we've added + + align:start position:0% +better environmental gains we've added + + + align:start position:0% +better environmental gains we've added +value and enforce stronger business + + align:start position:0% +value and enforce stronger business + + + align:start position:0% +value and enforce stronger business +practices in their community all at a + + align:start position:0% +practices in their community all at a + + + align:start position:0% +practices in their community all at a +lower cost \ No newline at end of file diff --git a/lET4uQLpmM0.txt b/lET4uQLpmM0.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fd197cd2f5824e7fecb5449e88278701730ba4e --- /dev/null +++ b/lET4uQLpmM0.txt @@ -0,0 +1,1091 @@ +align:start position:0% + +in this segment we discuss a little more + + align:start position:0% +in this segment we discuss a little more + + + align:start position:0% +in this segment we discuss a little more +the mean squared error consider some + + align:start position:0% +the mean squared error consider some + + + align:start position:0% +the mean squared error consider some +estimator it can be any estimator not + + align:start position:0% +estimator it can be any estimator not + + + align:start position:0% +estimator it can be any estimator not +just the sample mean we can decompose + + align:start position:0% +just the sample mean we can decompose + + + align:start position:0% +just the sample mean we can decompose +the mean squared error as a sum of two + + align:start position:0% +the mean squared error as a sum of two + + + align:start position:0% +the mean squared error as a sum of two +terms where does this formula come from + + align:start position:0% +terms where does this formula come from + + + align:start position:0% +terms where does this formula come from +well we know that for any random + + align:start position:0% +well we know that for any random + + + align:start position:0% +well we know that for any random +variable Z this formula is valid and if + + align:start position:0% +variable Z this formula is valid and if + + + align:start position:0% +variable Z this formula is valid and if +we let Z be equal to the difference + + align:start position:0% +we let Z be equal to the difference + + + align:start position:0% +we let Z be equal to the difference +between the estimator and the value that + + align:start position:0% +between the estimator and the value that + + + align:start position:0% +between the estimator and the value that +we're trying to estimate then we obtain + + align:start position:0% +we're trying to estimate then we obtain + + + align:start position:0% +we're trying to estimate then we obtain +this formula here we expected value of + + align:start position:0% +this formula here we expected value of + + + align:start position:0% +this formula here we expected value of +our random variable Z squared is equal + + align:start position:0% +our random variable Z squared is equal + + + align:start position:0% +our random variable Z squared is equal +to the variance of that random variable + + align:start position:0% +to the variance of that random variable + + + align:start position:0% +to the variance of that random variable +plus the square of its mean let us now + + align:start position:0% +plus the square of its mean let us now + + + align:start position:0% +plus the square of its mean let us now +rewrite these two terms in a more + + align:start position:0% +rewrite these two terms in a more + + + align:start position:0% +rewrite these two terms in a more +suggestive way we first noticed that + + align:start position:0% +suggestive way we first noticed that + + + align:start position:0% +suggestive way we first noticed that +theta is a constant when you add or + + align:start position:0% +theta is a constant when you add or + + + align:start position:0% +theta is a constant when you add or +subtract a constant from a random + + align:start position:0% +subtract a constant from a random + + + align:start position:0% +subtract a constant from a random +variable the variance does not change so + + align:start position:0% +variable the variance does not change so + + + align:start position:0% +variable the variance does not change so +this term is the same as the variance of + + align:start position:0% +this term is the same as the variance of + + + align:start position:0% +this term is the same as the variance of +theta hat this quantity here we will + + align:start position:0% +theta hat this quantity here we will + + + align:start position:0% +theta hat this quantity here we will +call it the bias of the estimator it + + align:start position:0% +call it the bias of the estimator it + + + align:start position:0% +call it the bias of the estimator it +tells us whether theta hat is + + align:start position:0% +tells us whether theta hat is + + + align:start position:0% +tells us whether theta hat is +systematically above or below than the + + align:start position:0% +systematically above or below than the + + + align:start position:0% +systematically above or below than the +unknown parameter theta that we are + + align:start position:0% +unknown parameter theta that we are + + + align:start position:0% +unknown parameter theta that we are +trying to estimate and using this + + align:start position:0% +trying to estimate and using this + + + align:start position:0% +trying to estimate and using this +terminology this term here is just equal + + align:start position:0% +terminology this term here is just equal + + + align:start position:0% +terminology this term here is just equal +to the square of the bias so the mean + + align:start position:0% +to the square of the bias so the mean + + + align:start position:0% +to the square of the bias so the mean +squared error consists of two components + + align:start position:0% +squared error consists of two components + + + align:start position:0% +squared error consists of two components +and these capture different aspects of + + align:start position:0% +and these capture different aspects of + + + align:start position:0% +and these capture different aspects of +an estimators performance let us see + + align:start position:0% +an estimators performance let us see + + + align:start position:0% +an estimators performance let us see +what they are in the concrete setting + + align:start position:0% +what they are in the concrete setting + + + align:start position:0% +what they are in the concrete setting +suppose that were estimating the unknown + + align:start position:0% +suppose that were estimating the unknown + + + align:start position:0% +suppose that were estimating the unknown +mean of some distribution and that our + + align:start position:0% +mean of some distribution and that our + + + align:start position:0% +mean of some distribution and that our +estimator is the sample mean in this + + align:start position:0% +estimator is the sample mean in this + + + align:start position:0% +estimator is the sample mean in this +case the mean squared error is the + + align:start position:0% +case the mean squared error is the + + + align:start position:0% +case the mean squared error is the +variance which we know to be Sigma + + align:start position:0% +variance which we know to be Sigma + + + align:start position:0% +variance which we know to be Sigma +squared over n plus the bias term but we + + align:start position:0% +squared over n plus the bias term but we + + + align:start position:0% +squared over n plus the bias term but we +know that the sample mean is unbiased + + align:start position:0% +know that the sample mean is unbiased + + + align:start position:0% +know that the sample mean is unbiased +the expected value of the sample mean is + + align:start position:0% +the expected value of the sample mean is + + + align:start position:0% +the expected value of the sample mean is +equal to the unknown mean and so the + + align:start position:0% +equal to the unknown mean and so the + + + align:start position:0% +equal to the unknown mean and so the +bias contribution is equal to 0 now for + + align:start position:0% +bias contribution is equal to 0 now for + + + align:start position:0% +bias contribution is equal to 0 now for +the sake of a comparison let us consider + + align:start position:0% +the sake of a comparison let us consider + + + align:start position:0% +the sake of a comparison let us consider +a somewhat silly estimator which ignores + + align:start position:0% +a somewhat silly estimator which ignores + + + align:start position:0% +a somewhat silly estimator which ignores +the data altogether and always gives you + + align:start position:0% +the data altogether and always gives you + + + align:start position:0% +the data altogether and always gives you +and + + align:start position:0% +and + + + align:start position:0% +and +estimate of zero in this case the mean + + align:start position:0% +estimate of zero in this case the mean + + + align:start position:0% +estimate of zero in this case the mean +squared error is as follows + + align:start position:0% +squared error is as follows + + + align:start position:0% +squared error is as follows +since our estimator is just a constant + + align:start position:0% +since our estimator is just a constant + + + align:start position:0% +since our estimator is just a constant +it's variance is going to be equal to + + align:start position:0% +it's variance is going to be equal to + + + align:start position:0% +it's variance is going to be equal to +zero on the other hand since theta hat + + align:start position:0% +zero on the other hand since theta hat + + + align:start position:0% +zero on the other hand since theta hat +is zero this term here is just the + + align:start position:0% +is zero this term here is just the + + + align:start position:0% +is zero this term here is just the +constant theta squared and this gives us + + align:start position:0% +constant theta squared and this gives us + + + align:start position:0% +constant theta squared and this gives us +the corresponding mean squared error let + + align:start position:0% +the corresponding mean squared error let + + + align:start position:0% +the corresponding mean squared error let +us now compare the two estimators we + + align:start position:0% +us now compare the two estimators we + + + align:start position:0% +us now compare the two estimators we +will plot the mean squared error as a + + align:start position:0% +will plot the mean squared error as a + + + align:start position:0% +will plot the mean squared error as a +function of the unknown parameter theta + + align:start position:0% +function of the unknown parameter theta + + + align:start position:0% +function of the unknown parameter theta +for the sample mean estimator the mean + + align:start position:0% +for the sample mean estimator the mean + + + align:start position:0% +for the sample mean estimator the mean +squared error is constant does not + + align:start position:0% +squared error is constant does not + + + align:start position:0% +squared error is constant does not +depend on theta and is equal to this + + align:start position:0% +depend on theta and is equal to this + + + align:start position:0% +depend on theta and is equal to this +value Sigma squared over N on the other + + align:start position:0% +value Sigma squared over N on the other + + + align:start position:0% +value Sigma squared over N on the other +hand for the zero estimator the mean + + align:start position:0% +hand for the zero estimator the mean + + + align:start position:0% +hand for the zero estimator the mean +squared error is equal to theta squared + + align:start position:0% +squared error is equal to theta squared + + + align:start position:0% +squared error is equal to theta squared +how do they compare which one is better + + align:start position:0% +how do they compare which one is better + + + align:start position:0% +how do they compare which one is better +at this point there is no way to say + + align:start position:0% +at this point there is no way to say + + + align:start position:0% +at this point there is no way to say +that one is better than the other for + + align:start position:0% +that one is better than the other for + + + align:start position:0% +that one is better than the other for +some theta the sample mean has a smaller + + align:start position:0% +some theta the sample mean has a smaller + + + align:start position:0% +some theta the sample mean has a smaller +mean squared error but for other theta + + align:start position:0% +mean squared error but for other theta + + + align:start position:0% +mean squared error but for other theta +the 0 estimator has a smaller mean + + align:start position:0% +the 0 estimator has a smaller mean + + + align:start position:0% +the 0 estimator has a smaller mean +squared error but we do not know where + + align:start position:0% +squared error but we do not know where + + + align:start position:0% +squared error but we do not know where +the true value of theta is it could be + + align:start position:0% +the true value of theta is it could be + + + align:start position:0% +the true value of theta is it could be +anything so we cannot say that one is + + align:start position:0% +anything so we cannot say that one is + + + align:start position:0% +anything so we cannot say that one is +better than the other of course we know + + align:start position:0% +better than the other of course we know + + + align:start position:0% +better than the other of course we know +that the sample mean is a consistent + + align:start position:0% +that the sample mean is a consistent + + + align:start position:0% +that the sample mean is a consistent +estimator as n goes to infinity it will + + align:start position:0% +estimator as n goes to infinity it will + + + align:start position:0% +estimator as n goes to infinity it will +give you the true value of theta and + + align:start position:0% +give you the true value of theta and + + + align:start position:0% +give you the true value of theta and +this is a very desirable property that + + align:start position:0% +this is a very desirable property that + + + align:start position:0% +this is a very desirable property that +the zero estimator does not have but if + + align:start position:0% +the zero estimator does not have but if + + + align:start position:0% +the zero estimator does not have but if +n is moderate the situation is less + + align:start position:0% +n is moderate the situation is less + + + align:start position:0% +n is moderate the situation is less +clear if we have some good reason to + + align:start position:0% +clear if we have some good reason to + + + align:start position:0% +clear if we have some good reason to +expect that the true value of theta is + + align:start position:0% +expect that the true value of theta is + + + align:start position:0% +expect that the true value of theta is +somewhere in the vicinity of zero then + + align:start position:0% +somewhere in the vicinity of zero then + + + align:start position:0% +somewhere in the vicinity of zero then +the zero estimator might be a better one + + align:start position:0% +the zero estimator might be a better one + + + align:start position:0% +the zero estimator might be a better one +because it that will achieve a smaller + + align:start position:0% +because it that will achieve a smaller + + + align:start position:0% +because it that will achieve a smaller +mean squared error but in a classical + + align:start position:0% +mean squared error but in a classical + + + align:start position:0% +mean squared error but in a classical +statistical framework there is no way to + + align:start position:0% +statistical framework there is no way to + + + align:start position:0% +statistical framework there is no way to +express a belief of this kind + + align:start position:0% +express a belief of this kind + + + align:start position:0% +express a belief of this kind +in contrast if we were following a + + align:start position:0% +in contrast if we were following a + + + align:start position:0% +in contrast if we were following a +Bayesian approach you could provide a + + align:start position:0% +Bayesian approach you could provide a + + + align:start position:0% +Bayesian approach you could provide a +prior distribution for theta that would + + align:start position:0% +prior distribution for theta that would + + + align:start position:0% +prior distribution for theta that would +be highly concentrated around zero this + + align:start position:0% +be highly concentrated around zero this + + + align:start position:0% +be highly concentrated around zero this +would express your beliefs about theta + + align:start position:0% +would express your beliefs about theta + + + align:start position:0% +would express your beliefs about theta +and would provide you with the guidance + + align:start position:0% +and would provide you with the guidance + + + align:start position:0% +and would provide you with the guidance +to choose between the two estimators or + + align:start position:0% +to choose between the two estimators or + + + align:start position:0% +to choose between the two estimators or +maybe suggest an even better estimator + + align:start position:0% +maybe suggest an even better estimator + + + align:start position:0% +maybe suggest an even better estimator +in any case going back to this formula + + align:start position:0% +in any case going back to this formula + + + align:start position:0% +in any case going back to this formula +this quantity the variance of the + + align:start position:0% +this quantity the variance of the + + + align:start position:0% +this quantity the variance of the +estimator plays an important role in the + + align:start position:0% +estimator plays an important role in the + + + align:start position:0% +estimator plays an important role in the +analysis of different estimators and the + + align:start position:0% +analysis of different estimators and the + + + align:start position:0% +analysis of different estimators and the +more intuitive variant of this quantity + + align:start position:0% +more intuitive variant of this quantity + + + align:start position:0% +more intuitive variant of this quantity +is its square root which is the standard + + align:start position:0% +is its square root which is the standard + + + align:start position:0% +is its square root which is the standard +deviation of the estimator and is + + align:start position:0% +deviation of the estimator and is + + + align:start position:0% +deviation of the estimator and is +usually called the standard error of the + + align:start position:0% +usually called the standard error of the + + + align:start position:0% +usually called the standard error of the +estimator we can interpret the standard + + align:start position:0% +estimator we can interpret the standard + + + align:start position:0% +estimator we can interpret the standard +error as follows we have the true value + + align:start position:0% +error as follows we have the true value + + + align:start position:0% +error as follows we have the true value +of theta then on day one we collect some + + align:start position:0% +of theta then on day one we collect some + + + align:start position:0% +of theta then on day one we collect some +data we perform the estimation procedure + + align:start position:0% +data we perform the estimation procedure + + + align:start position:0% +data we perform the estimation procedure +and we come up with an estimate on day + + align:start position:0% +and we come up with an estimate on day + + + align:start position:0% +and we come up with an estimate on day +two we do the same thing but + + align:start position:0% +two we do the same thing but + + + align:start position:0% +two we do the same thing but +independently we collect a new set of + + align:start position:0% +independently we collect a new set of + + + align:start position:0% +independently we collect a new set of +data and we come up with another + + align:start position:0% +data and we come up with another + + + align:start position:0% +data and we come up with another +estimate and so on we do this many times + + align:start position:0% +estimate and so on we do this many times + + + align:start position:0% +estimate and so on we do this many times +we use different data sets to come up + + align:start position:0% +we use different data sets to come up + + + align:start position:0% +we use different data sets to come up +with different estimates and because of + + align:start position:0% +with different estimates and because of + + + align:start position:0% +with different estimates and because of +the randomness in the data these + + align:start position:0% +the randomness in the data these + + + align:start position:0% +the randomness in the data these +estimates may be all over the place well + + align:start position:0% +estimates may be all over the place well + + + align:start position:0% +estimates may be all over the place well +the standard error tells us how spread + + align:start position:0% +the standard error tells us how spread + + + align:start position:0% +the standard error tells us how spread +out all these estimates will be it is + + align:start position:0% +out all these estimates will be it is + + + align:start position:0% +out all these estimates will be it is +the standard deviation of this + + align:start position:0% +the standard deviation of this + + + align:start position:0% +the standard deviation of this +collection of estimates having a large + + align:start position:0% +collection of estimates having a large + + + align:start position:0% +collection of estimates having a large +standard error means that our estimation + + align:start position:0% +standard error means that our estimation + + + align:start position:0% +standard error means that our estimation +procedure is quite noisy and that our + + align:start position:0% +procedure is quite noisy and that our + + + align:start position:0% +procedure is quite noisy and that our +estimates have some inherent randomness + + align:start position:0% +estimates have some inherent randomness + + + align:start position:0% +estimates have some inherent randomness +and therefore also have a lack of + + align:start position:0% +and therefore also have a lack of + + + align:start position:0% +and therefore also have a lack of +accuracy that is they cannot be trusted + + align:start position:0% +accuracy that is they cannot be trusted + + + align:start position:0% +accuracy that is they cannot be trusted +too much that's the case of a large + + align:start position:0% +too much that's the case of a large + + + align:start position:0% +too much that's the case of a large +standard error conversely a small + + align:start position:0% +standard error conversely a small + + + align:start position:0% +standard error conversely a small +standard error would tell us that the + + align:start position:0% +standard error would tell us that the + + + align:start position:0% +standard error would tell us that the +estimates would tend to be concentrated + + align:start position:0% +estimates would tend to be concentrated + + + align:start position:0% +estimates would tend to be concentrated +close to each other as such the standard + + align:start position:0% +close to each other as such the standard + + + align:start position:0% +close to each other as such the standard +error is a very useful piece of + + align:start position:0% +error is a very useful piece of + + + align:start position:0% +error is a very useful piece of +information + + align:start position:0% +information + + + align:start position:0% +information +to have besides designing and + + align:start position:0% +to have besides designing and + + + align:start position:0% +to have besides designing and +implementing an estimator one usually + + align:start position:0% +implementing an estimator one usually + + + align:start position:0% +implementing an estimator one usually +also tries to find a way to calculate + + align:start position:0% +also tries to find a way to calculate + + + align:start position:0% +also tries to find a way to calculate +and report the associated standard error \ No newline at end of file diff --git a/lJOuPmI--5c.txt b/lJOuPmI--5c.txt new file mode 100644 index 0000000000000000000000000000000000000000..763cba99052b7d2eeb351fc22ddf1749b4930f71 --- /dev/null +++ b/lJOuPmI--5c.txt @@ -0,0 +1,1833 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK, so let's +start to discuss ion traps. + +Now, in many situations, ions +are just charged neutral atoms. + +And if the charge +doesn't matter, + +you can do very similar physics +with ions and neutral atoms. + +However, the charge +makes major differences + +when it comes to confining +and manipulating particles. + +So when I compare +neutrals to ions, + +the forces which we +exert on neutral atoms + +are magnetic forces, +optical forces. + +And typically, the +traps we can create + +have a depth of about 1 kelvin. + +Actually, you just need +superconducting magnets. + +The magnetic traps we build here +at MIT have millikelvin depths. + +So the trap depth is +often on the order + +of microkelvin, millikelvin, +and kelvin at the high scale. + +Well, this is very +different in ions. + +In ions, you have +the Coulomb force. + +If you take electric fields +of 100 volts per millimeter, + +you can create confinement +forces for 10,000 kelvin. + +So you have no problem in +confining room temperature + +ions. + +When it comes to-- so this +is trapping and confinement. + +If you talk about cooling, +well, our workhorses + +are Doppler cooling and +evaporative cooling. + +You can actually cool +ions by evaporation. + +You can also cool ions +by evaporative cooling. + +But what has been very +common and special to ions + +is the ability to resolve +sidebands, sidebands + +of the vibration and motion in +the harmonic oscillator trap. + +And in problem +set number 10, you + +have looked through the +physics of sideband cooling. + +However, sideband cooling +is now also coming back + +to neutral atoms. + +For instance, if you have +neutral atoms in a very tightly + +confining dipole trap, +you can resolve sidebands + +and use those for cooling. + +OK, what is the science? + +Well, a driving force for +both ions and neutral atoms + +has been clocks. + +If atoms are cold, +you can use them + +to have very accurate +ways of keeping time. + +And I think currently, +there is a race + +between the based neutral +atom atomic clocks, + +neutral [INAUDIBLE] +optical lattices, + +and ion traps in particular, +the aluminum ion at Boulder. + +So we have clocks. + +In ions-- and this is what I +want to talk a little bit more + +about today-- a major driving +force was quantum information. + +You have two ions and get +quantum gates between them, + +or you have eight +ions and can have now + +eight qubits in a +prototypical quantum computer. + +So quantum information +science and quantum algorithms + +was quite important. + +But I would say +some of the physics + +is at least discussed +and partially pursued + +with atoms in optical lattices. + +We have talked a lot +about, for neutral atoms, + +quantum simulations, +studying super fluidity, + +studying phase transitions, +magnetic properties + +of many body systems. + +But there are more efforts +to do that with ions. + +Chris Monroe's +group in Maryland is + +studying antiferromagnetic +ordering of a spin chain. + +And the spin chain consists of +a string of ions in an ion trap. + +So see actually on +the science side + +that all three-- clocks, +precision measurements, quantum + +information, qubits, quantum +algorithms, and quantum + +simulation of many +body systems-- + +are done with both +neutral atoms and ions. + +So these are now two +very different platforms. + +So I could spend a +long time teaching + +about special aspects of ions. + +How do you do a trap? + +How do you cool ions? + +How do you do quantum +state control? + +Because this is +our last lecture, + +I decided to focus +on two aspects. + +One is, I want to talk about a +special way of trapping ions. + +Because there is one +difference for ions. + +Ions, until recently, +have not been + +trapped in stationary traps. + +They've only been +trapped in dynamic traps. + +So you cannot trap ions by +simply putting an electric + +potential around it. + +Because the divergence of +the electric field is 0. + +And that means there's +always one direction in space + +where the ions are dragged out. + +You cannot have an inward +force from all directions. + +So therefore, when you want +to use electric fields, + +you can only use dynamic traps. + +Well, for the +experts I should say, + +this does not apply for +the optical dipole trap. + +We know how we can create +trapping potentials + +for neutral atoms using +the optical dipole trap. + +And very recently, a group +was able to trap ions + +not with electric and magnetic +fields provided by electrodes + +or radio frequency, but by +inner focused laser beams. + +So it's a very new development. + +But it uses exactly +the mechanism + +which has been used +for neutral atoms. + +So when it comes +to dynamic traps, + +the standard two +traps which have + +been used for ion trapping-- +one is the Penning trap, + +which I do not want +to describe in detail. + +The Penning trap uses a +quadrupole configuration + +of two positive charges. + +And then you have a ring +with negative charge. + +That means that an +ion is confined here + +but would see anti-confinement +in the outward direction. + +Now, what you do with +the anti-confinement? + +Well, the solution is that +you add a magnetic field. + +And what happens +now is the particle + +is well-confined axially. + +But radially, when +it wants to move out, + +it's turned into +a cyclotron orbit, + +and therefore stays trapped. + +So this is the principal +of Penning traps + +where the confinement +in the axial direction + +is electrostatic, and +the confinement in x, y + +is through cyclotron motion. + +OK, it's wonderful +physics to describe + +the motion of ions in this trap. + +It's the combination +of an axial motion, + +cyclotron motion, +magnetron motion. + +It's very interesting physics. + +And for many years, Dave +Pritchard here at MIT + +used such Penning traps to +measure the masses, determine + +the masses, of ions with +the highest precision ever + +possible. + +MIT still has the world +record of the most precise + +mass measurements at the +10 to the minus 11 level. + +And this was done +in Penning traps. + +But I want to talk more today +about RF traps, or Paul traps, + +because the are used in the +majority of experiments. + +And they're used in pretty +much all experiments + +on quantum information +processing with ions. + +So the neat thing-- +and I try to teach you + +concepts in physics-- the +interesting thing about Paul + +traps or RF traps is that +you alternate at a radio + +frequency between confinement +and anti-confinement. + +You can say you have a +settle point potential, which + +is confining in x and +anti-confining in y. + +But then, you switch x and y. + +So therefore, the situation +is just imagine you're an ion, + +and you feel half of the time +a confining harmonic oscillator + +and half of the time an +anti-confining harmonic + +oscillator. + +The question I have for you, +and this is a general physics + +question, well, is +the sum of a confining + +and an anti-confining potential +of the same strength give 0, + +or does it give something +which in the end is confining? + +So if you were in a potential, +and the potential switches + +permanently form parabolic +upward to parabolic + +downward, at any given position, +the average force is 0. + +Because in one phase, you +have a force to the left. + +In the other case, +you have the opposite. + +You have the same +force but to the right + +with the opposite sign. + +But what's going on here? + +Yes. + +AUDIENCE: So I can't answer +this mathematically or even + +physically. + +But I just remember +this very cool example + +that someone showed me once +where they took a saddle shape + +in space, put a +ball in the middle, + +and then you spin the saddle. + +And as soon as the ball +tries to fall to one side, + +the saddle will spin +over and pick it up. + +So I know the answer has +to be, it is confining. + +But I can't explain why. + +PROFESSOR: OK, Colin? + +AUDIENCE: Could it possibly +be like a threshold? + +Because if you consider +spinning it sort of slowly, + +then the particle can +just sort of roll off. + +Maybe there's a threshold. + +PROFESSOR: Yeah, +there is a threshold. + +I mean, if there's a +confining potential + +for a long, long +time, and then there's + +an anti-confining potential, +and I just fall down + +the anti-confining potential, +and I disappear to infinity, + +the confining part +doesn't help me. + +So there will definitely +be a threshold in time. + +We have to switch between +confining and anti-confining + +sufficiently rapidly. + +Yes. + +AUDIENCE: Does it +have something to do + +with fictitious +force [INAUDIBLE]? + +PROFESSOR: No, but this would +have been a possibility. + +Maybe there is a formalism. + +But the standard formalism does +not use the rotating frame. + +Let me-- + +AUDIENCE: You could think +of the classical analog + +where you have a bead on a wire, +and you have a stable position + +at sort of a finite angle +only at certain frequencies. + +PROFESSOR: Yes, I'm not sure. + +Anyway, you all-- I think +everybody here works + +with optics or knows +what optics is. + +So why don't I +discuss the following. + +If you take a positive +lens and a negative lens + +with equal strength, what +happens now to your laser beam? + +You send a laser +beam through, it + +gets an inward bend by the +convex lens, an outward bend + +by the concave lens. + +Is the net effect nothing, +or is it focusing? + +Well, it depends. + +What happens is the following. + +If the lenses are put +in close proximity, + +the two bending actions on the +rays just completely cancel. + +But now we can do the following. + +We can put the two +lenses further apart. + +And now the following happens. + +We have a laser beam +which is bent inward. + +And you probably all know +the lens maker's equation, + +that the further +out the rays are, + +the more they have to be bent +inward to come to a focus. + +So what happens is those +beams are now bent inward. + +But when they reach +the other lens, + +they are now bent +outward somewhat. + +I'm not very accurate +in my drawing. + +But the angle by +which they're bent + +inward is proportional +to the separation here. + +The angle by which +they're bent outward + +is proportional to +the separation there. + +So the inward bend is stronger +than the outward bend. + +So therefore what +I'm telling you + +is convex and concave, +with a certain distance + +between the two, +results in focusing. + +Now maybe you can +think about it. + +What happens if I reverse +convex and concave? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Is it +now still focusing, + +or is it the opposite +of the example above? + +Now the first lens bends +the beam outward, yes? + +And the second lens +bends it inward. + +But since we reach the +second lens further out, + +the invert kick is stronger +than the outward bend initially. + +So therefore, when you have +positive and negative lenses + +of equal strength, no matter +in what order you apply it, + +you always get an inward force. + +So this should +actually explain-- + +AUDIENCE: As long as they're +within the focal length. + +Could you imagine if I +had positive and negative + +that was larger than +the focal length away? + +PROFESSOR: Yeah, +everything within reason + +here-- there will be +a stability diagram. + +But I want to first make it +very plausible what happens. + +And just to address the +question which I raised before, + +if I'm in a potential, +and I get an equal amount + +of inward and outward force, +shouldn't that average to 0? + +The question is how you average. + +If I would keep the distance +from the x as constant, + +I would say here as a function +of-- let me call it x. + +The bending angle as a +function of x is positive. + +The bending angle at +the same x is negative. + +So if I would do the average +at constant x, I would get 0. + +But what I do is I do +the average following + +the trajectory of the beam. + +So in other words, +if I'm sitting + +on this potential, which +switches from attractive + +to repulsive, if I would +be here at my position, + +the average force is 0. + +But when the potential is +repulsive, in 1/2 cycle + +I'm pushed outwards. + +And further out, +the attractive force + +is now stronger +than it was before. + +And therefore, if you average +the force at my position, + +you will always find +an inward force. + +But if you average the +force at a fixed location, + +it averages out to 0. + +So this is exactly +how RF ion traps work. + +And well, the rest are just +equations to describe that. + +So I think we have +to make a choice. + +I could derive for +you the equations, how + +you average over the rapid +oscillations of the potential, + +and you get a harmonic +oscillator potential, + +and this is how you trap ions. + +But it's pretty +much showing to you + +how the concept I've +just explained to you + +is reflected in equations. + +Or the second option we have +that takes about 20 minutes + +is to explain to you how +quantum computation is + +done with two +ions, in particular + +how the famous +Zoller-Cirac gate works. + +Do you have a clear preference? + +AUDIENCE: Second one. + +PROFESSOR: OK, fine, +but there is one piece + +of mathematics you +should understand. + +Really, and this +is the only essence + +of the mathematical derivation. + +If I'm standing here, and I +feel the alternating force, + +it's a cosine omega t, +and it averages to 0. + +But if the force drives +me, it shakes me. + +This is micromotion. + +Like the beam here, if you +go through many lasers, + +the beam goes up and +down, up and down. + +This is micromotion. + +The micromotion is +at cosine omega t. + +And the net +attractive force comes + +because the force which +oscillates at cosine omega t, + +and I'm oscillating +at cosine omega t, + +then you get cosine +squared omega t. + +And this gives you +the net force which + +provides the net +attractive force. + +And it's the cosine square term +averaged over the micromotion, + +which is one half, which is +responsible for the trapping + +potential in ion traps. + +Anyway, you know the +physics very well. + +You understand where the math +comes form in that it's really + +just the product of the two. + +It's a rectification. + +It's an alternating force. + +But since the system +itself, the particle itself, + +is driven at the micromotion, +there's rectification going on, + +which leads to the +cosine squared term. + +[? Timor, ?] yes? + +AUDIENCE: Two quick questions. + +So I think ion trappers always +complain about the micromotion. + +But in fact, they +need it for trapping + +to work-- is pretty much +what's going on here, right? + +PROFESSOR: Yes, actually, +the one interesting side + +of the mathematics is the +micromotion is kinetic energy. + +The harmonic +trapping potential is + +nothing else than +the micromotion. + +In other words, if people +show in an ion trap + +that you have a +harmonic oscillator, + +the harmonic oscillator +potential is high here. + +But mathematically, this +harmonic oscillator potential + +is the kinetic energy +of the micromotion. + +In other words, if you +look at the micromotion, + +it has a kinetic energy. + +The kinetic energy appears +as the potential energy + +in this slow secular motion. + +So in other words, the +potential energy for the trap + +is the kinetic energy +of the micromotion. + +So you can't avoid it. + +This is responsible for +the restoring force. + +AUDIENCE: Is it a really +conservative trap, + +or can I have an out +of phase component + +to the micromotion response? + +Is there like a sine +part to the response? + +PROFESSOR: Well, the secular +motion is conservative. + +You're now asking-- + +AUDIENCE: I'm trying to think +if there would be a reason why + +my response, my +dipole response, would + +have a different [INAUDIBLE]. + +Is there a reason? + +PROFESSOR: Well, to the +best of my knowledge, + +everything is +wonderfully conservative + +if you have a +separation of timescale. + +If you want to sort +of get something + +strange and non-conservative +out of the micromotion, + +you have to violate the +adiabatic separation + +of timescales. + +There is a possibility that +if particles move quickly + +through the +potential, they're not + +following the micromotion +adiabatically. + +And then there is a +collision where micromotion + +is released as +collisional energy. + +But on the similar +particle level, + +it's a pretty good +approximation. + +OK, we want to talk about +quantum computation with ions. + +[INAUDIBLE] has a +wonderful write-up + +on the wiki on the basic +concept of quantum computation + +and how it applies to ions. + +But let me immediately +jump to qubit operations. + +You've heard many, many +times that a general quantum + +algorithm can be constructed +out of single qubit + +rotations and two qubit gates. + +Single qubit rotations +are just oscillations + +on the Bloch sphere. + +If you excite a particle, move +it around on the Bloch sphere, + +this is how you can rotate a +single qubit from ground state + +to excited state, any +possible superposition state. + +So the physics of single +atoms, Rabi oscillation, + +rotation on the Bloch +sphere, this is all you + +have to know about +single qubit operations. + +The interesting thing is how do +we create two qubit operations? + +And two qubit +operation would mean + +you want to do something +to one ion here depending + +what the state of +the other ion is. + +And this is much more subtle. + +So what I want to +explain to you now + +is the famous Cirac-Zoller +gate, which was really + +a pioneering paper which has +thousands of citations now. + +Because it showed that +quantum computation + +can be experimentally realized +in a rather straightforward + +way. + +So it's a fundamental theorem of +quantum information processing + +that if you have single +qubit operations, and one + +to qubit gate, which is +a CNOT gate, that this + +is a universal set +of quantum gates, + +any arbitrary quantum algorithm +can be constructed out + +of those gate operations. + +So let me just remind you +what the CNOT gate is. + +We have qubits ion one, ion two. + +They can be in 0 or 1. + +These can be two different +hyperfine states. + +Or in the case of the calcium +ion, it can be the ground state + +or metastable excited state-- +just two different states + +of ion one, two different +states of ion two. + +The CNOT gate would +now say the following. + +The first ion is +the control bit. + +And whenever the +control bit is 1, + +it flips the qubit, +the second qubit. + +If the control bit is 0, it +does nothing to the second ion. + +So therefore, the table +which shows how the quantum + +states perform is +1, 1, 0, 0, 1, 1. + +It just shows that +I'm writing down + +the matrix in these spaces. + +It's a truth table 0, +0, 0, 1, 1, 0, 1, 1. + +And it shows that when you +have 1, 1 at the input, + +you get 1, 0 at the output. + +If you have 1, 0 at the input, +you get 1, 1 at the output. + +Well, the two qubit +gate I want to discuss, + +which can be realized in +the simplest possible way + +with the Cirac-Zoller algorithm, +is the controlled phase qubit, + +which has a truth table +of 1, 1, 1, minus 1. + +And it means it simply +changes the face of the two + +qubit states when +both qubits are 1. + +Now, the CNOT gate +can be constructed out + +of the controlled phase gate +by having two single qubit + +rotations done with +the Hadamard gate. + +The Hadamard gate is taking +the bases 1 and 2 and creates 1 + +plus 2, 1 minus 2, the +symmetric and anti-symmetric + +superposition state. + +So therefore, the CPHASE gate +is S general as the CNOT gate. + +Because one can be used +to construct the other. + +So how do we create +the Cirac-Zoller gate? + +So how do we get now +the controlled phase + +gate out of trapped ions? + +So the effect is the following. + +Remember, if we +have two ions, we + +want to change the phase +to minus 1 of the state + +only if the two +ions are qubit up. + +So in other words, we want to do +180 degree rotation of the wave + +function, but only +if both ions are up. + +And the question is, +how do we do that? + +How does one ion feel what +the other ion is doing? + +And let me explain that now. + +The critical element in +the Cirac-Zoller case + +is a center of mass motion. + +We want at some point-- say +when this ion is spin up, + +we swap the quantum +information from the ion + +to the center of mass motion. + +In other words, when this ion +is up, we use laser pulses. + +I will explain that to you. + +Then all the ions +are moving together. + +And then, this ion, +because they're all moving, + +knows that this ion +was spin up before. + +So the center of mass motion, +the common dipole oscillation + +of all ions together in the +trap, this is the data bus. + +So this is the key idea. + +But in order to explain it to +you, I have to go in two steps. + +So let's just take that as +a genetic level structure. + +We have an S state. + +And it has two different +hyperfine states, + +spin up and spin down. + +And these are our two qubits. + +There may be a P state, which +we have used for laser cooling. + +But everything is in the +ground state of motion + +using sideband +cooling, which you've + +studied in your homework. + +And what I want +to show you first + +is how we can +create a phase gate. + +But I'm only +focusing on ion one. + +So hold the thought. + +Ion two will come in a few +moments, will come back. + +So what we can do +is the following. + +Each qubit state has vibrational +structure-- ground state, + +excited state without +center of mass motion. + +But then, as a function of +vibrational quantum number + +for the center of +mass motion, we + +have g1, g2, e1, e2, and such. + +And what we can now +do is, let's assume + +we have another state, +a D state, which + +is an auxiliary state here. + +Fortunately, ions and +atoms have many states. + +And we can drive a +laser transition from S + +to D, which is only in resonance +with the first vibrational + +excited state to the D state. + +So we use a [INAUDIBLE] +sideband here, + +which only drives the +transition from e1 + +to the non-vibrational state +of the auxiliary state. + +And that means automatically +that this laser does nothing + +to e0, does nothing to +g0, does nothing to g1. + +So if you have this Hilbert +space of g0, g1, e0, e1, + +the only transition +which is effected here, + +or the only state which is +effected here, is the e1 state. + +OK, I'm talking +about a single ion. + +I'm just talking about talking +to a single ion right now. + +It's really simple. + +So if we switch on this +laser, what happens + +is we simply induce Rabi +oscillations-- simple physics. + +The Rabi oscillation, +however, after one Rabi period + +has changed the phase of the +initial state by minus 1. + +If you carefully look what +Rabi oscillations are, + +the wave function goes +up, down, up, down. + +But we usually discuss what +happens to the probability. + +And this is shown in green. + +So when we are back +in the original state, + +we have changed the phase of +the wave function by minus 1. + +So let's just assume that +we switch on this laser + +to this auxiliary state, +and we have a-- well, + +it's a 2 pi pulse in population. + +But it makes a phase shift +of pi to the wave function, + +which is minus 1. + +So what we have +accomplished now is + +a phase gate not +between two ions. + +But we have a phase gate +which, in this Hilbert space, + +between the qubit +up, qubit down-- + +I call it ground +and excited state. + +But the other +qubit, so to speak, + +is the center of mass +motion 0, 1, 0, 1. + +So this is the truth +table of the phase gate. + +And so technically, we have +now done a local phase gate + +with one ion where +the two qubits are + +ground and excited +state of the ion. + +This is our qubit we +want to work with. + +But then, the second qubit +to realize the phase gate + +was 0, 1 of the center +of mass vibration. + +But once we have +realized that, we + +can now immediately +take this idea + +and get a phase gate +between two ions. + +Because the center of mass +vibration is everywhere. + +So therefore, what we can +do is this was ion one. + +We can now-- and this +is the missing step + +I want to show +you-- go to ion two. + +And we can swap the qubit +information-- ground, excited, + +spin up, spin down. + +We can swap that with the +center of mass motion. + +So therefore, what we can do is, +when the second ion is spin up, + +we do a swapping +of the information + +from spin up, spin down +to center of mass motion + +being 0 or 1. + +So the idea is the following. + +Ion two should control +what ion one is doing. + +So we first focus on ion two. + +We swap the qubit of ion two +into the center of mass motion. + +Then, we do what I just +said, the controlled phase + +gate for ion one with the +center of mass motion. + +And after this is done, we write +the center of mass motion back + +into ion two. + +And then we have +nothing to ion two. + +Ion two was just +putting its information + +into the center of mass motion. + +It helped ion one to do +the controlled phase gate. + +And then, we swapped +the information back. + +So this is the sequence. + +After preparing the center of +mass, the first of two lasers + +cool everything in the center +of mass motion into the 0 state. + +Then we swap from ion +two the information + +to this phonon state +center of mass vibration. + +Then we do the controlled +phase gate on ion one. + +And then, we swap +the information back. + +So what I should show +you-- you may have seen it. + +But what I should +show you explicitly-- + +how do we swap +the information ge + +from the internal +state of ion two? + +How do we write this information +into the data bus, which + +is the phonon, +which is the center + +of mass vibration in the trap? + +Well, we again use +[INAUDIBLE] side pulse. + +We do a pi pulse +driving this transition. + +And just look how beautifully +the math works out. + +We have an arbitrary +qubit state, + +a superposition of +ground and excited. + +And the center of +mass motion was + +laser cooled to +the ground state. + +So let me just +multiply that out. + +So we have coefficient a times +g0 plus coefficient b times e0. + +If we now do a pi pulse, we +transfer the population from e0 + +into g1. + +And this is what I've done here. + +But now you see I +can factor out the g. + +And what I have now is I have +the same qubit information + +with coefficients e and b, but +no longer in the internal state + +of the ion but in +the phonon state + +in the qubit, which is +the center of mass motion. + +So the idea here is you can have +an arbitrary number of ions. + +And now you want to +have a quantum gate. + +What you do with a +quantum gate, you say, + +I want to now take this +ion here and have a quantum + +gate with 10 ions further down. + +So you first go +to your first ion, + +transfer the information of +this qubit into the data bus, + +into the center of mass motion. + +And now with a local +operation here, + +you can do something to this +ion conditionally on the motion, + +the center of mass motion. + +But the center of mass +motion reflects the ion + +over there, in +which state it was. + +And after you have +done the two qubit + +operation between +those two ions, + +you take the center +of mass motion, + +put it back into this ion. + +And at the end of the +day what you have done + +is you have done a +two qubit operation. + +You've changed the +state of this ion. + +But all the other ions +have remained the same. + +And with that, you can +now, in a chain of ion, + +implement arbitrary +two qubit operations. + +I think I said it +clearer in words here. + +It is in a little +bit more formal way + +the steps you will do +to the wave function. + +You initialize. + +Your transfer the +information to the data bus, + +you execute the +controlled phase gate, + +and you put the information +from the data bus + +back into the control ion. + +And now your data bus +is free, is back again + +to the initial value and +ready for the next operation. + +I should mention that +this was pioneering paper. + +Right now, this quantum gate +is not the most popular one. + +Because it has +severe requirements. + +One is you really have to cool +to the absolute ground state. + +The center of mass +motion has to be + +cooled to the +absolute ground state. + +There are other +quantum gates which + +do not require such +extreme cooling. + +And secondly, the center of mass +motion, because all particles + +move together, is one of the +slowest vibrational motions + +in the system. + +And if you want to +scale up the system + +to more and more particles, +the speed of the gate operation + +has to be slower than +the vibrational period + +of the center of mass motion. + +So these are two disadvantages. + +But there are different +gates, like geometric gates, + +like Sorensen gates. + +There are other possibilities +to involve the same quantum + +logic with ions. + +But the one of +Cirac-Zoller really + +stands out by it's pedagogy. + +It's really a +wonderful way to see + +how we take the information, +put it in a data bus, + +do the controlled +phase operation, + +and then proceed to the +next two qubit gate. + +OK, so that's the end of +ions, the end of this class. + +Do you have any questions +about the last topic? + +If not, let me say thanks. + +You were a fabulous class. + +I really enjoyed the +classroom atmosphere. + +I enjoyed all the +questions, whether it + +was after class or during class. + +And, well, I'm happy +that most of you + +I will see around for +a number of years. + +All right. + +[APPLAUSE] \ No newline at end of file diff --git a/leXa7EKUPFk.txt b/leXa7EKUPFk.txt new file mode 100644 index 0000000000000000000000000000000000000000..e914b3f2bdab5f6dd2f957f89c11e52cbc33d855 --- /dev/null +++ b/leXa7EKUPFk.txt @@ -0,0 +1,2353 @@ +PROFESSOR PATRICK WINSTON: +Ladies and gentlemen, the + +engineers drinking song. + +Back in the day, I've drunk +quite a lot to that song. + +And as drinking songs +go, it's not bad. + +I caution you, however, before +playing this song in the + +presence of small children, +audition it first. + +Some of the verses are +sufficiently gross as to make + +a sailor go beyond blushing. + +It's an interesting song because +there are an infinite + +number of verses. + +Here's the mathematical proof. + +Suppose there were a finite +number of verses. + +Then there would be +a last verse. + +And if there were a last verse, +then some drunk alumni + +would compose a new one. + +Therefore, there is no last +verse, the size is not finite, + +and there are an infinite +number of verses. + +I play it for you today because +I'm an engineer. + +I like to build stuff. + +I build stuff out of wood. + +I build stuff out of metal. + +I build stuff out of rocks. + +And I especially like +to write programs. + +I don't know, sometimes people +come to me and say, I'm + +majoring in computer science, +but I don't + +like to write programs. + +I've always been mystified +by that. + +I mean, if you want to show how +tough you are, you can go + +bungee jumping or drive a nail +through your hand or something + +like that instead. + +But I've written quite a few +programs for demonstrating + +stuff in this subject. + +They're all written in Java, +principally because I can + +therefore make them available to +you and to the rest of the + +world by way of Web Start. + +A few weeks ago, I was mucking +around with the system and + +broke the version on the server, +and within 15 minutes, + +I got an email from somebody +in the depths of Anatolia + +complaining about it and asking +me to bring it back up. + +This particular program +is patterned + +after an early AI classic. + +And it was the business end of +a program written by Terry + +Winograd, who became, and is, +a professor of computer + +science at Stanford +University-- + +which is on the west coast +for those of you-- + +on the strength of his work on +the natural language front end + +of this program. + +But the natural language part +is not what makes it of + +interest for us today. + +It's more the other +kinds of stuff. + +Let's pile these things up. + +Now, I'm going to ask to +do something, maybe put + +B2 on top of B7. + +Not bad. + +How about B6 on B3? + +This program's kind of clever. + +Let me do one more. + +Let's put B7 on B2. + +OK, now let's see. + +Maybe B5 on B2? + +B4 on B3 first, maybe? + +Oh, I must have clicked +the wrong button. + +Oh, there it goes. + +OK. + +Let's put B4 on B1. + +Agh, my mouse keeps getting +out of control. + +Now, let's put B1 on B2. + +This is an example I'm +actually going to + +work out on the board. + +Oh, I see. + +My touch pad accidentally +got activated. + +B1 on B2. + +Now, let's ask a question. + +OK. + +Well. + +SPEAKER 2: [SINGING] + +PROFESSOR PATRICK +WINSTON: Stop. + +SPEAKER 3: [LAUGHTER] + +PROFESSOR PATRICK WINSTON: +Had enough of that. + +Let's see. + +Why did you put-- + +why did you want to +get rid of B4? + +OK, one-- + +SPEAKER 2: [SINGING] + +PROFESSOR PATRICK WINSTON: Maybe +they think, that's what + +happens when you use software +you write yourself. + +Why did you want to clear +the top of B2? + +Did I do that? + +Why did you clear +the top of B1? + +OK. + +SPEAKER 2: [SINGING] + +SPEAKER 3: [LAUGHTER] + +PROFESSOR PATRICK WINSTON: +Oh, it's haunting me. + +Yeah. + +So the drinking song is easily +offended, I guess. + +But I won't develop that +scenario again. + +What I want to show you is that +this program looks like + +it's kind of smart, and it +somehow can answer questions + +about its own behavior. + +Have you ever written a program +that's answered + +questions about its +own behavior? + +Probably not. + +Would you like to learn +how to do that? + +OK. + +So by the end of the hour, +you'll be able to write this + +program and many more like it +that know how to answer + +questions about their +own behavior. + +There have been tens of +thousands of such programs + +written, but only by people who +know the stuff I'm going + +to tell you about +right now, OK? + +So what I want to do is I want +to start by taking this + +program apart on the board and +talking to you about the + +modules, the subroutines +that it contains. + +So here it is. + +The first thing we need +to think about, + +here are some blocks. + +What has to happen if I'm going +to put the bottom block + +on the larger block? + +Well, first of all, I have +to find space for it. + +Then I have to grasp +the lower block. + +And I have to move it and +I have to ungrasp it. + +So those are four things I need +to do in order to achieve + +what I want to do. + +So therefore, I know that the +put-on method has four pieces. + +It has to find space on +the target block. + +It has to grasp the block that +it's been commanded to move. + +Then it has to move, and +then it has to ungrasp. + +But taking hints from some of +the questions that it did + +answer before I got haunted by +the music, taking our cue from + +that, we know that in order to +grasp something, in this + +particular world, you can't have +anything on top of it. + +So grasp, therefore, may call +clear top in order to get + +stuff off from the +target object. + +And that may happen in an +iterative loop because there + +may be several things on top. + +And how do you get +rid of stuff? + +Well, by calling get rid of. + +And that may go around +a loop several times. + +And then, the way you get rid of +stuff is by calling put-on. + +So that gives us recursion, and +it's from the recursion + +that we get a lot of the +apparent complexity of the + +program's behavior when +it solves a problem. + +Now, in order to find space, +you also have to + +call get rid of. + +So that's where I meant to +put this other iterative + +loop, not down here. + +Cleat top has got the iterative +loop inside of it. + +So that's the structure +of the program. + +It's extremely simple. + +And you might say to me, well, +how can you get such + +apparently complex-looking +behavior out of + +such a simple program? + +A legitimate question. + +But before we tackle that one +head on, I'd like to do a + +simulation of this program +with a very + +simple blocks problem. + +And it's the one I almost +showed you, but + +it goes like this. + +Here's B1. + +We'll call this BX because +I forgot its name. + +Here's BY. + +And here's B2. + +And the task is to +put B1 on B2. + +And according to our system +diagram, that results in four + +calls to subroutines. + +We have to find space. + +We have to grasp B1. + +We have to move, and +then we ungrasp. + +Now, the way we grasp something +is the first thing + +we have to do is clear +off its top. + +So grasp calls clear top. + +And clear top in turn +calls get rid of. + +And let me see. + +Let me keep track of these. + +This is clearing the top +of B1, and this is + +getting rid of BX. + +And the way we get rid of BX is +by putting BX on the table. + +And then that in turn causes +calls to another find space, + +another grasp, another move, +and another ungrasp. + +So that's a little trace of +the program as it works on + +this simple problem. + +So how does it go about +answering the questions that I + +demonstrated to you +a moment ago? + +Let's do that by using +this trace. + +So how, for example, does it +answer the question, why did + +you get rid of BX? + +[INAUDIBLE], what +do you think? + +How can it answer +that question? + +SPEAKER 4: [INAUDIBLE] + +PROFESSOR PATRICK WINSTON: So +it goes up one level and + +reports what it sees. + +So it says, and said in the +demonstration, I got rid of BX + +because I was trying to +clear the top of B1. + +So if I were to say why did you +clear the top of B1, it + +would say because I was +trying to grasp it. + +If I were to say, why did you +grasp B1, it would say because + +I was putting B1 on B2. + +If I say, why did you put +B1 on B2, it would say, + +slavishly, because +you told me to. + +OK, so that's how it deals +with why questions. + +How about how questions? + +Timothy, what do you think +about that one? + +How would it go about answering +a question about how + +you did something? + +Do you have a thought? + +TIMOTHY: Um, yeah, it would +think about what I was trying + +to accomplish. + +PROFESSOR PATRICK WINSTON: +Yeah, but + +how would it do that? + +How would the program do that? + +We know that answering +a why question makes + +it go up one level. + +How does it answer +a how question? + +Sebastian? + +SEBASTIAN: It goes +down one level. + +PROFESSOR PATRICK WINSTON: +You go down one level. + +So you start off all the way +up here with a put-on. + +You will say, oh, well I +did these four things. + +You say, why did you grasp B1? + +It will say because I was +trying to clear its top. + +Why did you clear its top? + +Because I was trying +to get rid of it. + +Why were you trying +to get rid of it? + +Because I was trying to +put it on the table. + +So that's how it answers how +questions, by going down in + +this tree and this trace of the +program of action so as to + +see how things are +put together. + +What are these things that +are being put together? + +What's the word I've been +avoiding so as to bring this + +to a crescendo? + +What are these objectives, these +things it wants to do? + +They're goals. + +So this thing is leaving a +trace, which is a goal tree. + +Does that sound familiar? + +Three days ago, we talked about +goal trees in connection + +with integration. + +So this thing is building a goal +tree, also known as an + +and-or tree. + +So this must be an and tree. + +And if this is an and tree, +are there any and nodes? + +Sure, there's one right there. + +So do you think then that you +can answer questions about + +your own behavior as long as +you build an and-or tree? + +Sure. + +Does this mean that the +integration program could + +answer questions about +its own behavior? + +Sure. + +Because they both build goal +trees, and wherever you got a + +goal tree, you can answer +certain kinds of questions + +about your own behavior. + +So let me see if in fact it +really does build itself a + +goal tree as it solves +problems. + +So this time, we'll put +B6 on B3 this time. + +But watch it develop +its goal tree. + +So in contrast to the simple +example I was working on the + +board, this gets to be a pretty +complicated goal tree. + +But I could still answers +questions about behavior. + +For example, I could say, why +did you put B6 on B3? + +Because you told me to. + +All right, so the complexity of +the behavior is largely a + +consequence not of the +complexity of the program in + +this particular case, but the +building of this giant goal + +tree as a consequence of the +complexity of the problem. + +This brings us to one of +our previous matters-- + +early on to one of the gold +star ideas of today. + +And this gold star idea goes +back to a lecture given in the + +late '60s by Herb Simon, who was +the first Nobel Laureate + +in the pseudo Nobel Prize +for economics. + +Is that right, Bob? + +Was he the first? + +All right, he was the first +winner of the Nobel Prize, + +pseudo Nobel Prize +in economics. + +And in this lecture, which was +titled "The Sciences of the + +Artificial," he said imagine +that you're looking on a beach + +at the path of a ant. + +And he said, well, you know, +the path of the ant looks + +extremely complicated. + +And you're tempted to think the +ant is some kind of genius + +or monster brain ant. + +But in fact, when you take a +closer look, what you discover + +is that there are a bunch of +pebbles on the beach, and all + +the ant is doing is avoiding +those pebbles on his way home. + +So the complexity of the +behavior, said Simon, is a + +consequence of the complexity +of the environment, not the + +complexity of the program. + +So that's the metaphoric +Simon's ant. + +And what it says is that the +complexity of the behavior is + +the max of the complexity of the +program and the complexity + +of the environment. + +So that's something we'll see +many times during the rest of + +the semester. + +Complex behavior, +simple program. + +You think it's going +to be complicated. + +It turns out to be simple +because the problem has the + +complexity, not the program. + +So that brings us to check box +three in today's talk, and + +there's a little bit of a scene +here because now I want + +to stop talking about +goal-centered programming and + +start talking about rule-based +expert systems. + +The rule-based expert systems +were developed in a burst of + +enthusiasm about the prospects +for commercial applications of + +artificial intelligence +in the mid-1980s. + +At that time, it was supposed +lengthy articles are written, + +but you could account for +useful aspects of human + +intelligence by writing all the +knowledge in the form of + +simple rules. + +So if this is true, +then that's true. + +If you want to achieve +this, then do that. + +But all the knowledge had to be +encapsulated in the form of + +simple rules. + +So what might you want +to do with this? + +All sorts of things. + +Thousands of these systems +were written, + +as I indicated before. + +But here's an example. + +I'm going to work out an example +having to do with + +identification. + +And this example is patterned +off of a classic program, + +strangely also written at +Stanford, called MYCIN. + +It was developed to +diagnose bacterial + +infections in the blood. + +So you come in. + +You got some horrible disease, +and the doctor gets curious + +about what antibiotic would be +perfect for your disease. + +He starts asking a +lot of questions. + +So I'm not going to deal with +that because that world has + +all kinds of unpronounceable +terms like bacterioides and + +anaerobic and stuff like that. + +So it's completely analogous +to talk about identifying + +animals in a little zoo, sort +of a small town type of zoo. + +So I'm going to suggest that +we write down on a piece of + +paper all the things we can +observe about an animal, and + +then we'll try to figure +out what the animal is. + +So I don't know, what +can we start with? + +Has hair. + +Then there are some +characteristics of the + +following form. + +Has claws. + +Sharp teeth. + +And forward-pointing eyes. + +And these are all +characteristics of carnivores. + +We happen to have +forward-pointing eyes too, but + +that's more because we used to +swing around the trees a lot, + +and we needed the +stereo vision. + +And we don't have the claws +and the sharp teeth + +that go with it. + +But anyhow, those are typically +characteristics of + +carnivores, as is eating meat. + +And this particular little +animal we're looking at has + +also got spots, and +it's very fast. + +What is it? + +Well, everybody says +it's a cheetah. + +Let's see how our program +would figure that out. + +Well, program might say, let's +see if it has hair, then rule + +one says that that means +it must be a mammal. + +We can imagine another rule that +says if you have sharp + +claws, sharp teeth, and +forward-pointing eyes, then + +you're a carnivore. + +And I'm using sort of hardware +notation here. + +That's an and gate, right? + +So that means we have to have +all of these characteristics + +before we will conclude that +the animal is a carnivore. + +Now, this animal has been also +observed to eat meat. + +So that means we've got extra +evidence that the animal is + +carnivorous. + +And now, because the animal is +a mammal and a carnivore and + +has spots, and it's very fast, +then the animal is a cheetah. + +And I hope all of our African +students agree that + +it must be a cheetah. + +It's a small zoo-- + +I mean, a big zoo. + +Who knows what it is? + +It's probably got some +unpronouncable name-- + +there's possibilities. + +But for our small zoo, +that will do. + +So we have group now written +down in the form + +of these and gates. + +Several rules, R1, R2-- +and there needs to + +be an and gate here-- + +that's R3 and an R4. + +All of which indicate that +this animal is a cheetah. + +So we built ourself a little +rule-based expert system that + +can recognize exactly one +animal, but you could imagine + +filling out this system with +other rules so that you could + +recognize giraffes and penguins +and all the other + +sorts of things you find +in a small zoo. + +So when you have a system like +this that works as I've + +indicated, then what we're +going to call that, we're + +going to give that a special +name, and we're going to call + +that a forward-chaining +rule-based-- + +because it uses rules-- + +expert system. + +And we're going to put expert +in parentheses because when + +these things were developed, +for marketing reasons, they + +called them expert systems +instead of novice systems. + +But are they really experts +in a human sense? + +Not really, because they have +these knee-jerk rules. + +They're not equipped with +anything you might want to + +call common sense. + +They don't have an ability to +deal with previous cases, like + +we do when we go to +medical school. + +So they really ought to be +called rule-based novice + +systems because they reason +like novices on + +the basis of rules. + +But the tradition +is to call them + +rule-based expert systems. + +And this one works forward from +the facts we give it to + +the conclusion off +on the right. + +That's why it's a +forward-chaining system. + +Can this system answer +questions + +about its own behavior? + +[INAUDIBLE], what +do you think? + +SPEAKER 5: [INAUDIBLE]. + +PROFESSOR PATRICK +WINSTON: Why? + +SPEAKER 5: [INAUDIBLE]. + +PROFESSOR PATRICK WINSTON: +Because it + +looks like a goal tree. + +Right. + +This is, in fact, building a +goal tree because each of + +these rules that require several +things to be true is + +creating an and node. + +And each of these situations +here where you have multiple + +reasons for believing that the +thing is a carnivore, that's + +creating an or node. + +And we already know that you +can answer questions about + +your own behavior if you leave +behind a trace of a goal tree. + +So look at this. + +If I say to it, why were +you interested in + +the animal's claws? + +Because I was trying to see +if it was a carnivore. + +How did you know that the +animal is a mammal? + +Because it has hair. + +Why did you think it +was a cheetah? + +Because it's a mammal, +a carnivore, has + +spots, and very fast. + +So by working forward and +backward in this goal tree, + +this too can answer questions +about its own behavior. + +So now you know how, going +forward, you can write + +programs that answer questions +about their behavior. + +Either you write the subroutines +so that each one + +is wrapped around a goal, so +you've got goal-centered + +programming, or you build a +so-called expert system using + +rules, in which case it's easy +to make it leave behind a + +trace of a goal tree, which +makes it possible to answer + +questions about its own +behavior, just as this + +[INAUDIBLE] + +program did. + +But now, a little +more vocabulary. + +I'm going to save time by +erasing all of these things + +that I previously drew by +way of connections. + +And I'm going to approach this +zoo in a little different way. + +I'm going to not ask any +questions about the animal. + +Instead, I'm going to say, +mommy, is this thing I'm + +looking at a cheetah? + +And how would mommy go about +figuring it out. + +In her head, she would say, +well, I don't know. + +If it's going to be a cheetah, +then it must be the case that + +it's a carnivore, and it must be +the case that it has spots. + +And it must be the case +that it's very fast. + +So so far, what we've +established is that if it's + +going to be a cheetah, it +has to have the four + +characteristics that +mommy finds behind + +this rule are four. + +So instead of working forward +from facts, what I'm going to + +do is work backward +from a hypothesis. + +So here the hypothesis is +this thing is a cheetah. + +How do I go about showing +whether that's true or not? + +Well, I haven't done anything so +far because all I know is a + +cheetah if all these things are +true, but are they true? + +Well, to find out if it's a +mammal, I can use rule one. + +And if I know or can determine +that the animal has hair, then + +that part of it is +taken care of. + +And I can similarly work my way +back through carnivore. + +I say, well, it's a carnivore if +it has claws, sharp teeth, + +and forward-pointing eyes. + +And then as much as the +animal in question + +does, then I'm through. + +I know it's a carnivore. + +I don't have to go through and +show that it's a carnivore + +another way. + +So I never actually ask +questions about + +whether it eats meat. + +Finally, the final two +conditions are met by just an + +inspection of the animal. + +That's to say, it's +in the database. + +I don't have to use any rules +to determine that the animal + +has spots and is very fast. + +So now, I've got everything in +place to say that it's a + +cheetah, because it's a +carnivore, because it has + +claws, sharp teeth, and +forward-pointing eyes, and all + +the rest of this stuff is +similarly determined by going + +backwards, backwards from the +hypothesis toward the facts, + +instead of from the facts +forward to the conclusions. + +So building a system that works +like that, I have a + +backward-chaining rule-based +expert system. + +But there's a very important +characteristic of this system + +in both backward and forward +mode, and that is that this + +thing is a deduction system. + +That's because it's +working with facts + +to produce new facts. + +When you have a deduction +system, you can never take + +anything away. + +But these rule-based systems are +also used in another mode, + +where it's possible to +take something away. + +See, in fact world, in deduction +world, you're + +talking about proving things. + +And once you prove something +is true, it can't be false. + +If it is, you've got a +contradiction in your system. + +But if you think of this as a +programming language, if you + +think of using rules as a +programming language, then you + +can think of arranging it so +these rules add or subtract + +from the database. + +Let me show you an example +of a couple of systems. + +First of all, since I've talked +about the MYCIN system, + +let me show you an example +of a MYCIN dialogue. + +That's a MYCIN dialogue. + +And you can see the appearance +of words you have to go to + +medical school to learn. + +And here's a typical MYCIN rule, +just like the rules for + +doing zoo analysis, only a +more complicated domain. + +But here's another example of a +system that was written, not + +in the '80s, but just a couple +of years ago by a student in + +the architecture department, +Ph.D. thesis. + +He was interested in the +architecture of a Portuguese + +architect named Siza. + +And Siza's done a lot of +mass housing stuff. + +And Siza has the idea that you +ought to be able to design + +your own house. + +And so Jose Duarte, a Portuguese +student, a Ph.D. + +student in architecture, wrote +a rule-based system that was + +capable of designing Siza-like +houses in response to the + +requirements and recommendations +and desires of + +the people who are going +to occupy the houses. + +So the most compelling part of +this thing, of this exercise, + +was that Duarte took some of +the designs of the program, + +mixed them up with some of the +designs of Siza, and put them + +in front of Siza, and said, +which ones did you do? + +And Siza couldn't tell. + +So somehow, the rule-based +system that was built using + +this kind of technology was +sufficient to confuse even the + +expert that they were +patterned after. + +But this program is a +little complicated. + +It, too, has its own +specialized lingo. + +So I'm not going to talk about +it in detail, but rather talk + +instead about an analogous +problem. + +And that is a problem that +everyone has faced at one + +point or another, and that +is the problem of putting + +groceries in a bag at +a grocery store. + +It's the same thing, right? + +Instead of putting rooms in +a house, you're putting + +groceries in a bag. + +And there must be some rules +about how to do that. + +In fact, maybe some of you have +been professional grocery + +store baggers? + +[INAUDIBLE] a grocery store +professional bagger. + +You're a-- + +which one? + +LISA: [INAUDIBLE] + +PROFESSOR PATRICK WINSTON: +Yeah, what is your name? + +LISA: Lisa. + +PROFESSOR PATRICK +WINSTON: Lisa. + +OK, well we got two +professional + +grocery store baggers. + +And I'm going to be now +simulating a highly paid + +knowledge engineer desirous of +building a program that knows + +how to bag groceries. + +So I'm going to visit your site, +Market Basket, and I'm + +going to ask Lisa, now fearful +of losing her job, if she + +would tell me about how +she bags groceries. + +So could you suggest a rule? + +LISA: Sure. + +Large items in the bottom. + +PROFESSOR PATRICK WINSTON: Large +items in the bottom. + +You see, that's why I'm a +highly paid knowledge + +engineer, because I translate +what she said + +into an if-then rule. + +So if large, then bottom. + +So now I-- + +SPEAKER 3: [LAUGHTER] + +PROFESSOR PATRICK WINSTON: So +how about you, [INAUDIBLE]? + +Have you got a suggestion? + +About how to bag groceries? + +SPEAKER 6: The small +things on top. + +PROFESSOR PATRICK WINSTON: +If small, then on top. + +Lisa, have you got anything +else you could tell me? + +LISA: Don't put too many heavy +things in the same bag. + +PROFESSOR PATRICK WINSTON: +Don't put too many heavy + +things in the same bag. + +So if heavy greater than +three, then new bag, or + +something like that. + +Is that all we're going to be +able to-- does anybody else + +want to volunteer? + +[INAUDIBLE], have you bagged +groceries in Turkey? + +LISA: So they don't +have grocery + +baggers, so we have to-- + +PROFESSOR PATRICK WINSTON: So +everybody's a professional + +bagger in Turkey. + +Yeah. + +It's outsourced to +the customers. + +SPEAKER 7: So no squishies +on the bottom. + +So if you have-- + +PROFESSOR PATRICK WINSTON: No +squishies on the bottom. + +SPEAKER 7: If you +have tomatoes-- + +PROFESSOR PATRICK WINSTON: +That's good. + +Tomatoes. + +SPEAKER 7: You don't want +them to get squished. + +PROFESSOR PATRICK WINSTON: Now, +there's a very different + +thing about squishies and +tomatoes because tomato is + +specific, and squishy isn't. + +Now, one tendency of MIT +students, of course, is that + +we all tend to generalize. + +I once knew a professor +in the Sloan School + +who seemed real smart. + +And-- + +SPEAKER 3: [LAUGHTER] + +PROFESSOR PATRICK +WINSTON: Then I + +figured out what he did. + +If I were to say, I'm thinking +about a red apple. + +They'd sit back and say, oh, +I see you're contemplating + +colored fruit today. + +They're just taking it up one +level of abstraction. + +Not a genius. + +He also was able to talk for +an hour after he drew a + +triangle on the board. + +Amazing people. + +Anyhow, where were we? + +Oh, yes, bagging groceries. + +So we're making some progress, +but not as + +much as I would like. + +And so in order to really make +progress on tasks like this, + +you have to exercise-- + +you know about some principles +of knowledge engineering. + +So principle number one, which +I've listed over here as part + +of a gold star idea, is deal +with specific cases. + +So while you're at the site, if +all you do is talk to the + +experts like Lisa and +[INAUDIBLE], all you're going + +to get is vague generalities +because they won't think of + +everything. + +So what you do is you +say, well, let me + +watch you on the line. + +And then you'll see that they +have to have some way of + +dealing with the milk. + +And then you'll see that they +have to have some way of + +dealing with the potato chips. + +Nobody mentioned potato chips, +except insofar as they might + +be squishy. + +We don't have a definition +for squishy. + +Nobody talked about +the macaroni. + +And no one talked about +the motor oil. + +This is a convenience store. + +I don't want that in the +same bag with the meat. + +And then no one talked +about canned stuff. + +Here's a can of olives. + +So by looking at specific cases, +you elicit from people + +knowledge they otherwise would +not have thought to give you. + +That's knowledge engineering +rule number one. + +And within a very few minutes, +you'll have all three + +knowledge engineering rules and +be prepared to be a highly + +paid knowledge engineer. + +Heuristic, let's call +these heuristics. + +Heuristic number one, +specific cases. + +Heuristic number two is ask +questions about things that + +appear to be the same, but are +actually handled differently. + +So there's some Birds Eye +frozen peas, and here-- + +ugh, some fresh cut +sweet peas. + +And to me, the person who's +never touched a grocery bag in + +my life-- maybe I'm +from Mars-- + +I can't tell the difference. + +They're both peas. + +But I observe that the experts +are handling these objects + +differently. + +So I say, why did you handle +those peas differently from + +those peas, and what +do they say? + +One's canned, and +one's frozen. + +So what happens? + +Bingo, I've got some new +words in my vocabulary. + +And those new vocabulary words +are going to give me power + +over the domain because +I can now use + +those words in my rules. + +And I can write rules like if +frozen, then put them all + +together in a little +plastic bag. + +Actually, that's too +complicated, but that's what + +we end up doing, right? + +Why do we put them +all together in a + +little plastic bag? + +SPEAKER 8: [INAUDIBLE] + +PROFESSOR PATRICK WINSTON: +What's that? + +SPEAKER 8: [INAUDIBLE] + +PROFESSOR PATRICK WINSTON: +Well, there are two + +explanations. + +There's the MIT explanation. + +We know that temperature flow +is equal to the fourth power + +of the temperature difference +and the surface area and all + +that kind of stuff. + +We want to get them all together +in a ball, sphere. + +The normal explanation is that +they're going to melt anyway, + +so they might as well not +get everything else wet. + +All right. + +SPEAKER 3: [LAUGHTER] + +PROFESSOR PATRICK WINSTON: So +that's heuristic number two. + +And actually, there's heuristic +number three, that I + +just want to relate to you for +the first time because I have + +been dealing with it a lot +over this past summer. + +Heuristic number three is you +build a system, and you see + +when it cracks. + +And when it cracks is when you +don't have one of the rules + +you need in order to execute-- + +in order to get the program +to execute as + +you want it to execute. + +So if I were to write a grocery +store bagging program + +and have it bag some groceries, +again, eventually + +it would either make a mistake +or come to a grinding halt, + +and bingo, I know that there's +a missing rule. + +Isn't that what happens when you +do a problem set, and you + +hit an impasse? + +You're performing an experiment +on yourself, and + +you're discovering that you +don't have the whole program. + +In fact, I've listed this as a +gold star idea having to do + +with engineering yourself +because all of these things + +that you can do for knowledge +engineering are things you can + +do when you learn a new +subject yourself. + +Because essentially, you're +making yourself into an expert + +system when you're learning +circuit theory or + +electromagnetism or something +of that sort. + +You're saying to yourself, +well, let's look at some + +specific cases. + +Well, what are the vocabulary +items here that tell me why + +this problem is different +from that problem? + +Oh, this is a cylinder +instead of a sphere. + +Or you're working with a problem +set, and you discover + +you can't work with the problem, +and you need to get + +another chunk of knowledge +that makes it possible + +for you to do it. + +So this sort of thing, which +you think of primarily as a + +mechanism, heuristics for doing +knowledge engineering, + +are also mechanisms for making +yourself smarter. + +So that concludes what I want to +talk with you about today. + +But the bottom line is, that +if you build a rule-based + +expert system, it can +answer questions + +about its own behavior. + +If you build a program that's +centered on goals, it can + +answer questions about +its own behavior. + +If you build an integration +program, it can answer + +questions about its +own behavior. + +And if you want to build one of +these systems, and you need + +to extract knowledge from an +expert, you need to approach + +it with these kinds of +heuristics because the expert + +won't think what to tell you +unless you elicit that + +information by specific cases, +by asking questions about + +differences, and by ultimately +doing some experiments to see + +where your program is correct. + +So that really concludes what I +had to say, except I want to + +ask the question, is this all +we need to know about human + +intelligence? + +Can these things be-- + +are these things really smart? + +And the traditional answer is +no, they're not really smart + +because their intelligence is +this sort of thin veneer. + +And when you try to get +underneath it, as written, + +they tend to crack. + +For example, we talk about a +rule, we could talk about a + +rule that knows that you should +put the potato chips on + +the top of the bag. + +But a program that knows that +would have no idea why you + +would want to put the potato +chips on top of the bag. + +They wouldn't know that if you +put them on the bottom of the + +bag, they'll get crushed. + +And it wouldn't know that if +they get crushed, the customer + +will get angry, because people +don't like to eat crushed + +potato chips. + +So that's what I mean when I +say the knowledge of these + +things tends to be a veneer. + +So the MYCIN program, during +debugging, once prescribed a + +barrel of penicillin to be +administered to a patient for + +its disease. + +They don't know, they don't +have any common sense. + +So the question then becomes, +well, I don't know. + +Does rule-based-- + +do rules have anything to +do with common sense? + +And I'm becoming a little bit +agnostic on that subject. + +Because there are certain +indications, there are certain + +situations, in which rules could +be said to play a role + +in our ordinary understanding +of things. + +Would you like to see +a demonstration? + +What I'm going to show you, +when the clip speaks up-- + +well, before I make any +promises, let me see if I'm + +actually connected to the web. + +MIT, good. + +MIT. + +Guest. + +Yeah, that's me. + +Sounds good. + +OK, I just tested the system, +and I've seen it is actually + +connected to the web. + +And I'm going to adjust some +systems options here. + +I'll get rid of the text box. + +And we'll get rid of those +changes scale a little bit. + +What I'm going to do is I'm +going to read a little + +synopsis of the Macbeth plot. + +You're MIT students. + +I'm sure you're all classically +educated and very + +familiar with Shakespearean +plots. + +So I'm going to read one. + +I'm going to read a version +of a Macbeth plot. + +And it's going to go +along like this. + +It's basically reading +a rule base so far. + +And pretty soon, it's going to +get beyond the rule base and + +start reading the +Macbeth story. + +And there it is. + +It's read the Macbeth story. + +Let me show you what the Macbeth +story looks like as + +it's actually retained +by the system. + +That's it. + +Read that. + +OK, you ran out of +time because the + +machine's already finished. + +It takes about five seconds +to read this story. + +Now, as you look at this little +synopsis of Macbeth, + +there are a couple +things to note. + +For one thing, it says that +Duncan is murdered. + +Duncan, I hope this doesn't +bother you. + +Duncan is murdered by Macbeth. + +But at no time does it say +that Duncan is dead. + +But you know Duncan's dead +because he was murdered. + +If murdered, then dead. + +SPEAKER 3: [LAUGHTER]. + +PROFESSOR PATRICK WINSTON: So +if you look a little further + +down, what you see is that +Macduff kills Macbeth. + +Fourth line up from +the bottom. + +Why did Macduff kill Macbeth? + +Doesn't say why in this story, +but you have no trouble + +figuring out that it's +because he got angry. + +And when you get angry, you +don't necessarily kill + +somebody, but it's possible. + +SPEAKER 3: [LAUGHTER]. + +PROFESSOR PATRICK WINSTON: So +now that you see what's in the + +story, let me take you +back to this display. + +It's what we call an +elaboration graph. + +And when I blow it up, you can +see that there's some familiar + +looking things in there. + +For example, up here in the +left-hand corner, Macbeth + +murders Duncan, right +over there. + +And over here, Macduff +kills Macbeth. + +And if you look at what is a +consequence of that, it looks + +like there must be a rule that +says if you murder somebody, + +you harm them. + +And if you murder somebody, +then they're dead. + +And one reason why you might +kill somebody is because they + +angered you. + +And if you go the other way, +one consequence of killing + +somebody is that you harm them, +and that they die too. + +And if you harm somebody, they +get angry, and their state + +goes negative. + +So that suggests that there are +some things that we have + +on our hands that are very +compiled and very, strangely + +enough, very rule-like +in their character. + +Now, to close, I'm just +going to read Hamlet. + +The Hamlet demonstration is +much like the Macbeth one. + +In fact, Hamlet and Macbeth are +very alike in their plot. + +But there's one thing that's +well-illustrated by our + +particular capturing +of Hamlet here. + +And that is that you'll note +that the ratio of gray stuff + +to white stuff is +considerable. + +The gray stuff is stuff that +has been deduced by rules. + +And the reason there's so much +gray stuff in this Hamlet + +story is because everybody's +related to everybody else. + +So when you kill anybody, you +irritate everybody else. + +So look at that. + +A few white things, those are +the things that are explicit + +in the story, and lots +of gray stuff. + +So what this is suggesting is +that when we tell a story, + +it's mostly a matter of +controlled hallucination. + +I know what rules are in your +head, so I could take + +advantage of that in telling the +story and not have to tell + +you anything I'm sure you're +going to know. + +And so that's why, we've +discovered, that storytelling + +is largely a matter of just +controlling how you're going + +along, a kind of controlled +hallucination. \ No newline at end of file diff --git a/lw9W32ezQhM.txt b/lw9W32ezQhM.txt new file mode 100644 index 0000000000000000000000000000000000000000..b5dafe3e8d8133cbc73f7be9bff83ef028a30d24 --- /dev/null +++ b/lw9W32ezQhM.txt @@ -0,0 +1,499 @@ +align:start position:0% + +we are now in position to find the + + align:start position:0% +we are now in position to find the + + + align:start position:0% +we are now in position to find the +accelerations a1 a2 in the tension + + align:start position:0% +accelerations a1 a2 in the tension + + + align:start position:0% +accelerations a1 a2 in the tension +because we have Newton's second law and + + align:start position:0% +because we have Newton's second law and + + + align:start position:0% +because we have Newton's second law and +our constraint condition for the + + align:start position:0% +our constraint condition for the + + + align:start position:0% +our constraint condition for the +acceleration let's recall the equations + + align:start position:0% +acceleration let's recall the equations + + + align:start position:0% +acceleration let's recall the equations +that we found we had M 1 G minus T was + + align:start position:0% +that we found we had M 1 G minus T was + + + align:start position:0% +that we found we had M 1 G minus T was +m1 a1 and we had m2 G minus 2 T was + + align:start position:0% +m1 a1 and we had m2 G minus 2 T was + + + align:start position:0% +m1 a1 and we had m2 G minus 2 T was +equal to m2 a2 and we also had the + + align:start position:0% +equal to m2 a2 and we also had the + + + align:start position:0% +equal to m2 a2 and we also had the +condition constraint condition between + + align:start position:0% +condition constraint condition between + + + align:start position:0% +condition constraint condition between +the accelerations that a1 was minus 2 a + + align:start position:0% +the accelerations that a1 was minus 2 a + + + align:start position:0% +the accelerations that a1 was minus 2 a +2 so now we have a system of three + + align:start position:0% +2 so now we have a system of three + + + align:start position:0% +2 so now we have a system of three +equations and we can find we can solve + + align:start position:0% +equations and we can find we can solve + + + align:start position:0% +equations and we can find we can solve +for any of these quantities that we want + + align:start position:0% +for any of these quantities that we want + + + align:start position:0% +for any of these quantities that we want +so one way to do it is to identify an + + align:start position:0% +so one way to do it is to identify an + + + align:start position:0% +so one way to do it is to identify an +equation and to identify the quantity + + align:start position:0% +equation and to identify the quantity + + + align:start position:0% +equation and to identify the quantity +that we would like to solve for so for + + align:start position:0% +that we would like to solve for so for + + + align:start position:0% +that we would like to solve for so for +instance let's identify that we want to + + align:start position:0% +instance let's identify that we want to + + + align:start position:0% +instance let's identify that we want to +solve for a 1 first + + align:start position:0% +solve for a 1 first + + + align:start position:0% +solve for a 1 first +so how are we going to develop a + + align:start position:0% +so how are we going to develop a + + + align:start position:0% +so how are we going to develop a +strategy for that well I'll choose + + align:start position:0% +strategy for that well I'll choose + + + align:start position:0% +strategy for that well I'll choose +equation 1 as my backbone equation and I + + align:start position:0% +equation 1 as my backbone equation and I + + + align:start position:0% +equation 1 as my backbone equation and I +have an unknown T but in equation 2 that + + align:start position:0% +have an unknown T but in equation 2 that + + + align:start position:0% +have an unknown T but in equation 2 that +unknown T is appearing there but it's + + align:start position:0% +unknown T is appearing there but it's + + + align:start position:0% +unknown T is appearing there but it's +expressed in terms of a 2 and a 2 though + + align:start position:0% +expressed in terms of a 2 and a 2 though + + + align:start position:0% +expressed in terms of a 2 and a 2 though +from Equation 3 is expressed in terms of + + align:start position:0% +from Equation 3 is expressed in terms of + + + align:start position:0% +from Equation 3 is expressed in terms of +a 1 so my first step is to write + + align:start position:0% +a 1 so my first step is to write + + + align:start position:0% +a 1 so my first step is to write +equation rewrite equation 2 as m2 G + + align:start position:0% +equation rewrite equation 2 as m2 G + + + align:start position:0% +equation rewrite equation 2 as m2 G +minus 2 T equals m2 now here is I'm + + align:start position:0% +minus 2 T equals m2 now here is I'm + + + align:start position:0% +minus 2 T equals m2 now here is I'm +going to make the substitution which is + + align:start position:0% +going to make the substitution which is + + + align:start position:0% +going to make the substitution which is +minus a 1 over 2 so we'll call that 2a + + align:start position:0% +minus a 1 over 2 so we'll call that 2a + + + align:start position:0% +minus a 1 over 2 so we'll call that 2a +and now I have equation 1 and equation 2 + + align:start position:0% +and now I have equation 1 and equation 2 + + + align:start position:0% +and now I have equation 1 and equation 2 +a 2 unknowns T and a 1 and what I can do + + align:start position:0% +a 2 unknowns T and a 1 and what I can do + + + align:start position:0% +a 2 unknowns T and a 1 and what I can do +is I can solve for either equation and I + + align:start position:0% +is I can solve for either equation and I + + + align:start position:0% +is I can solve for either equation and I +can make a choice what's easiest when I + + align:start position:0% +can make a choice what's easiest when I + + + align:start position:0% +can make a choice what's easiest when I +look at these equations it's easiest for + + align:start position:0% +look at these equations it's easiest for + + + align:start position:0% +look at these equations it's easiest for +me to identify what T is in terms of a 1 + + align:start position:0% +me to identify what T is in terms of a 1 + + + align:start position:0% +me to identify what T is in terms of a 1 +so I'll write M 1 G minus M 1 a 1 is + + align:start position:0% +so I'll write M 1 G minus M 1 a 1 is + + + align:start position:0% +so I'll write M 1 G minus M 1 a 1 is +equal to T I'll call that equation 1 a + + align:start position:0% +equal to T I'll call that equation 1 a + + + align:start position:0% +equal to T I'll call that equation 1 a +and now I can substitute that value of T + + align:start position:0% +and now I can substitute that value of T + + + align:start position:0% +and now I can substitute that value of T +into equation 2 a and I get m2 G minus 2 + + align:start position:0% +into equation 2 a and I get m2 G minus 2 + + + align:start position:0% +into equation 2 a and I get m2 G minus 2 +times M 1 G minus M 1 + + align:start position:0% +times M 1 G minus M 1 + + + align:start position:0% +times M 1 G minus M 1 +and that's equal to minus em 2 over 2 + + align:start position:0% +and that's equal to minus em 2 over 2 + + + align:start position:0% +and that's equal to minus em 2 over 2 +times a 1 and now I'd like to collect my + + align:start position:0% +times a 1 and now I'd like to collect my + + + align:start position:0% +times a 1 and now I'd like to collect my +a 1 terms and what I have over here + + align:start position:0% +a 1 terms and what I have over here + + + align:start position:0% +a 1 terms and what I have over here +let's bring all the a 1 terms to this + + align:start position:0% +let's bring all the a 1 terms to this + + + align:start position:0% +let's bring all the a 1 terms to this +side and I get em 2 gee minus 2 & 1 gee + + align:start position:0% +side and I get em 2 gee minus 2 & 1 gee + + + align:start position:0% +side and I get em 2 gee minus 2 & 1 gee +I have a plus so I'm going to bring that + + align:start position:0% +I have a plus so I'm going to bring that + + + align:start position:0% +I have a plus so I'm going to bring that +over to this side and I get equal to + + align:start position:0% +over to this side and I get equal to + + + align:start position:0% +over to this side and I get equal to +that's plus plus so I'll have 2 minus + + align:start position:0% +that's plus plus so I'll have 2 minus + + + align:start position:0% +that's plus plus so I'll have 2 minus +signs and I'll have to M 1 plus M 2 over + + align:start position:0% +signs and I'll have to M 1 plus M 2 over + + + align:start position:0% +signs and I'll have to M 1 plus M 2 over +2 a 1 and now I can solve for a 1 and + + align:start position:0% +2 a 1 and now I can solve for a 1 and + + + align:start position:0% +2 a 1 and now I can solve for a 1 and +what I get is I get 2 & 1 G minus m2g + + align:start position:0% +what I get is I get 2 & 1 G minus m2g + + + align:start position:0% +what I get is I get 2 & 1 G minus m2g +and I want to divide through by this + + align:start position:0% +and I want to divide through by this + + + align:start position:0% +and I want to divide through by this +denominator and what I have downstairs + + align:start position:0% +denominator and what I have downstairs + + + align:start position:0% +denominator and what I have downstairs +is 2 m 1 plus M 2 divided by 2 and + + align:start position:0% +is 2 m 1 plus M 2 divided by 2 and + + + align:start position:0% +is 2 m 1 plus M 2 divided by 2 and +that's my expression for a 1 once I have + + align:start position:0% +that's my expression for a 1 once I have + + + align:start position:0% +that's my expression for a 1 once I have +that expression for a 1 I can easily + + align:start position:0% +that expression for a 1 I can easily + + + align:start position:0% +that expression for a 1 I can easily +come back and find out what a 2 is or I + + align:start position:0% +come back and find out what a 2 is or I + + + align:start position:0% +come back and find out what a 2 is or I +can substitute into the equation here + + align:start position:0% +can substitute into the equation here + + + align:start position:0% +can substitute into the equation here +for a 1 and find out what the tension is + + align:start position:0% +for a 1 and find out what the tension is + + + align:start position:0% +for a 1 and find out what the tension is +and so I can now easily find my + + align:start position:0% +and so I can now easily find my + + + align:start position:0% +and so I can now easily find my +expressions for a 2 and T but I will + + align:start position:0% +expressions for a 2 and T but I will + + + align:start position:0% +expressions for a 2 and T but I will +leave that as an exercise \ No newline at end of file diff --git a/lxpXowuUdKw.txt b/lxpXowuUdKw.txt new file mode 100644 index 0000000000000000000000000000000000000000..7e66ecd8dfb0f1e5f6e6a32fbd14e6086e8822e7 --- /dev/null +++ b/lxpXowuUdKw.txt @@ -0,0 +1,10795 @@ +align:start position:0% + +that says choices for your gaining + + align:start position:0% +that says choices for your gaining + + + align:start position:0% +that says choices for your gaining +project these are the six choices that + + align:start position:0% +project these are the six choices that + + + align:start position:0% +project these are the six choices that +we want to make available to you the + + align:start position:0% +we want to make available to you the + + + align:start position:0% +we want to make available to you the +next one is perhaps the most challenging + + align:start position:0% +next one is perhaps the most challenging + + + align:start position:0% +next one is perhaps the most challenging +one + + align:start position:0% +one + + + align:start position:0% +one +intellectually it's about new funding + + align:start position:0% +intellectually it's about new funding + + + align:start position:0% +intellectually it's about new funding +mechanisms for disas + + align:start position:0% +mechanisms for disas + + + align:start position:0% +mechanisms for disas +Bri I will explain this we call it + + align:start position:0% +Bri I will explain this we call it + + + align:start position:0% +Bri I will explain this we call it +forecast based financing or + + align:start position:0% +forecast based financing or + + + align:start position:0% +forecast based financing or +FBF and it's the the one that has the + + align:start position:0% +FBF and it's the the one that has the + + + align:start position:0% +FBF and it's the the one that has the +most potential to transform the + + align:start position:0% +most potential to transform the + + + align:start position:0% +most potential to transform the +humanitarian + + align:start position:0% +humanitarian + + + align:start position:0% +humanitarian +world all right moving to the next + + align:start position:0% +world all right moving to the next + + + align:start position:0% +world all right moving to the next +one the next one is the most + + align:start position:0% +one the next one is the most + + + align:start position:0% +one the next one is the most +complex um do you see the drawing of the + + align:start position:0% +complex um do you see the drawing of the + + + align:start position:0% +complex um do you see the drawing of the +time bomb with the fuse + + align:start position:0% +time bomb with the fuse + + + align:start position:0% +time bomb with the fuse +yes + + align:start position:0% +yes + + + align:start position:0% +yes +okay so allow me to give a little bit of + + align:start position:0% +okay so allow me to give a little bit of + + + align:start position:0% +okay so allow me to give a little bit of +context we did a little bit of this + + align:start position:0% +context we did a little bit of this + + + align:start position:0% +context we did a little bit of this +conversation when I showed up a few + + align:start position:0% +conversation when I showed up a few + + + align:start position:0% +conversation when I showed up a few +weeks ago but I imagine you all Forgot + + align:start position:0% +weeks ago but I imagine you all Forgot + + + align:start position:0% +weeks ago but I imagine you all Forgot +by now the humanitarian sector has two + + align:start position:0% +by now the humanitarian sector has two + + + align:start position:0% +by now the humanitarian sector has two +main funding + + align:start position:0% +main funding + + + align:start position:0% +main funding +mechanisms imagine a pot of + + align:start position:0% +mechanisms imagine a pot of + + + align:start position:0% +mechanisms imagine a pot of +money even if there's almost no money + + align:start position:0% +money even if there's almost no money + + + align:start position:0% +money even if there's almost no money +there if the pot exists money can go in + + align:start position:0% +there if the pot exists money can go in + + + align:start position:0% +there if the pot exists money can go in +to then be taken out to spend one of the + + align:start position:0% +to then be taken out to spend one of the + + + align:start position:0% +to then be taken out to spend one of the +pots of money that exists one of the + + align:start position:0% +pots of money that exists one of the + + + align:start position:0% +pots of money that exists one of the +funding mechanisms that exist is for + + align:start position:0% +funding mechanisms that exist is for + + + align:start position:0% +funding mechanisms that exist is for +Disaster Response meaning a hurricane a + + align:start position:0% +Disaster Response meaning a hurricane a + + + align:start position:0% +Disaster Response meaning a hurricane a +flood a volcanic eruption something has + + align:start position:0% +flood a volcanic eruption something has + + + align:start position:0% +flood a volcanic eruption something has +already happened is happening and is + + align:start position:0% +already happened is happening and is + + + align:start position:0% +already happened is happening and is +killing people people are dying but if + + align:start position:0% +killing people people are dying but if + + + align:start position:0% +killing people people are dying but if +you did something you could save lives + + align:start position:0% +you did something you could save lives + + + align:start position:0% +you did something you could save lives +for example get on a boat and rescue + + align:start position:0% +for example get on a boat and rescue + + + align:start position:0% +for example get on a boat and rescue +people who are stranding on a roof or + + align:start position:0% +people who are stranding on a roof or + + + align:start position:0% +people who are stranding on a roof or +people are sick go give them medicine + + align:start position:0% +people are sick go give them medicine + + + align:start position:0% +people are sick go give them medicine +this is Disaster Response and if you + + align:start position:0% +this is Disaster Response and if you + + + align:start position:0% +this is Disaster Response and if you +spend money you can do very good things + + align:start position:0% +spend money you can do very good things + + + align:start position:0% +spend money you can do very good things +and the funding mechanism exists there + + align:start position:0% +and the funding mechanism exists there + + + align:start position:0% +and the funding mechanism exists there +is another pot of money which is for a + + align:start position:0% +is another pot of money which is for a + + + align:start position:0% +is another pot of money which is for a +normal day the Red Cross has Vehicles + + align:start position:0% +normal day the Red Cross has Vehicles + + + align:start position:0% +normal day the Red Cross has Vehicles +the vehicles need maintenance they need + + align:start position:0% +the vehicles need maintenance they need + + + align:start position:0% +the vehicles need maintenance they need +to change tires you need to buy a new + + align:start position:0% +to change tires you need to buy a new + + + align:start position:0% +to change tires you need to buy a new +computer you need to pay rent and uh + + align:start position:0% +computer you need to pay rent and uh + + + align:start position:0% +computer you need to pay rent and uh +electricity bills you need to train + + align:start position:0% +electricity bills you need to train + + + align:start position:0% +electricity bills you need to train +stuff so on a normal day you have a + + align:start position:0% +stuff so on a normal day you have a + + + align:start position:0% +stuff so on a normal day you have a +budget for you know either maintenance + + align:start position:0% +budget for you know either maintenance + + + align:start position:0% +budget for you know either maintenance +or development of new projects or + + align:start position:0% +or development of new projects or + + + align:start position:0% +or development of new projects or +writing proposal and so on and that pot + + align:start position:0% +writing proposal and so on and that pot + + + align:start position:0% +writing proposal and so on and that pot +of money exists we call it the annual + + align:start position:0% +of money exists we call it the annual + + + align:start position:0% +of money exists we call it the annual +appeal every year we appeal for help and + + align:start position:0% +appeal every year we appeal for help and + + + align:start position:0% +appeal every year we appeal for help and +the people or donors or governments give + + align:start position:0% +the people or donors or governments give + + + align:start position:0% +the people or donors or governments give +us some money what does not exist is + + align:start position:0% +us some money what does not exist is + + + align:start position:0% +us some money what does not exist is +what the drawing the cartoon depicts + + align:start position:0% +what the drawing the cartoon depicts + + + align:start position:0% +what the drawing the cartoon depicts +which is when there's a signal from + + align:start position:0% +which is when there's a signal from + + + align:start position:0% +which is when there's a signal from +science that a disaster that something + + align:start position:0% +science that a disaster that something + + + align:start position:0% +science that a disaster that something +bad is likely to happen soon we don't + + align:start position:0% +bad is likely to happen soon we don't + + + align:start position:0% +bad is likely to happen soon we don't +have money to f action before the + + align:start position:0% +have money to f action before the + + + align:start position:0% +have money to f action before the +disaster after the forecast so if you + + align:start position:0% +disaster after the forecast so if you + + + align:start position:0% +disaster after the forecast so if you +click to see the text the context is + + align:start position:0% +click to see the text the context is + + + align:start position:0% +click to see the text the context is +that there's that missing money pot we + + align:start position:0% +that there's that missing money pot we + + + align:start position:0% +that there's that missing money pot we +have money for after the disaster we + + align:start position:0% +have money for after the disaster we + + + align:start position:0% +have money for after the disaster we +have money for the normal day but we + + align:start position:0% +have money for the normal day but we + + + align:start position:0% +have money for the normal day but we +don't have money for before the disaster + + align:start position:0% +don't have money for before the disaster + + + align:start position:0% +don't have money for before the disaster +after the forecast the issue is that if + + align:start position:0% +after the forecast the issue is that if + + + align:start position:0% +after the forecast the issue is that if +you spend money in that time window + + align:start position:0% +you spend money in that time window + + + align:start position:0% +you spend money in that time window +before the disaster after science says + + align:start position:0% +before the disaster after science says + + + align:start position:0% +before the disaster after science says +the disaster is likely you can do very + + align:start position:0% +the disaster is likely you can do very + + + align:start position:0% +the disaster is likely you can do very +good things for very cheap and and + + align:start position:0% +good things for very cheap and and + + + align:start position:0% +good things for very cheap and and +relative be simply and much more + + align:start position:0% +relative be simply and much more + + + align:start position:0% +relative be simply and much more +reliably it's not only more expensive + + align:start position:0% +reliably it's not only more expensive + + + align:start position:0% +reliably it's not only more expensive +but more difficult to Save a Life when + + align:start position:0% +but more difficult to Save a Life when + + + align:start position:0% +but more difficult to Save a Life when +the when the storm waters are flashing + + align:start position:0% +the when the storm waters are flashing + + + align:start position:0% +the when the storm waters are flashing +through a city and people are about to + + align:start position:0% +through a city and people are about to + + + align:start position:0% +through a city and people are about to +drown the boat is unstable whereas if + + align:start position:0% +drown the boat is unstable whereas if + + + align:start position:0% +drown the boat is unstable whereas if +you do it the day before when the water + + align:start position:0% +you do it the day before when the water + + + align:start position:0% +you do it the day before when the water +has come down from the sky but it's + + align:start position:0% +has come down from the sky but it's + + + align:start position:0% +has come down from the sky but it's +still in the river and not in the city + + align:start position:0% +still in the river and not in the city + + + align:start position:0% +still in the river and not in the city +people can take action by just walking + + align:start position:0% +people can take action by just walking + + + align:start position:0% +people can take action by just walking +away on their own means with their + + align:start position:0% +away on their own means with their + + + align:start position:0% +away on their own means with their +valuables and not just depending on + + align:start position:0% +valuables and not just depending on + + + align:start position:0% +valuables and not just depending on +someone to show with the boat so we came + + align:start position:0% +someone to show with the boat so we came + + + align:start position:0% +someone to show with the boat so we came +up with a financial mechanism we call it + + align:start position:0% +up with a financial mechanism we call it + + + align:start position:0% +up with a financial mechanism we call it +forecast based financing for disaster + + align:start position:0% +forecast based financing for disaster + + + align:start position:0% +forecast based financing for disaster +preparedness which is nuanced in how + + align:start position:0% +preparedness which is nuanced in how + + + align:start position:0% +preparedness which is nuanced in how +it's implemented there's a pot of money + + align:start position:0% +it's implemented there's a pot of money + + + align:start position:0% +it's implemented there's a pot of money +it's like a bank account you need to + + align:start position:0% +it's like a bank account you need to + + + align:start position:0% +it's like a bank account you need to +have a threshold of disaster risk that + + align:start position:0% +have a threshold of disaster risk that + + + align:start position:0% +have a threshold of disaster risk that +needs to be exceeded so it cannot be two + + align:start position:0% +needs to be exceeded so it cannot be two + + + align:start position:0% +needs to be exceeded so it cannot be two +drops of rain it has to be a lot of rain + + align:start position:0% +drops of rain it has to be a lot of rain + + + align:start position:0% +drops of rain it has to be a lot of rain +it cannot be some Breeze it has to be a + + align:start position:0% +it cannot be some Breeze it has to be a + + + align:start position:0% +it cannot be some Breeze it has to be a +hurricane category one or more but once + + align:start position:0% +hurricane category one or more but once + + + align:start position:0% +hurricane category one or more but once +the threshold is established and reached + + align:start position:0% +the threshold is established and reached + + + align:start position:0% +the threshold is established and reached +by the forecast then there some standard + + align:start position:0% +by the forecast then there some standard + + + align:start position:0% +by the forecast then there some standard +operating procedures some actions that + + align:start position:0% +operating procedures some actions that + + + align:start position:0% +operating procedures some actions that +people have to take spending money to + + align:start position:0% +people have to take spending money to + + + align:start position:0% +people have to take spending money to +save lives and that is something that if + + align:start position:0% +save lives and that is something that if + + + align:start position:0% +save lives and that is something that if +you could come up with a game that + + align:start position:0% +you could come up with a game that + + + align:start position:0% +you could come up with a game that +captures that this is the one that if we + + align:start position:0% +captures that this is the one that if we + + + align:start position:0% +captures that this is the one that if we +help communicate forecast based + + align:start position:0% +help communicate forecast based + + + align:start position:0% +help communicate forecast based +financing i s to the public because it + + align:start position:0% +financing i s to the public because it + + + align:start position:0% +financing i s to the public because it +can work for a broad audience digitally + + align:start position:0% +can work for a broad audience digitally + + + align:start position:0% +can work for a broad audience digitally +ideally would reach those who can + + align:start position:0% +ideally would reach those who can + + + align:start position:0% +ideally would reach those who can +contribute either money or decisions + + align:start position:0% +contribute either money or decisions + + + align:start position:0% +contribute either money or decisions +muscle power and + + align:start position:0% +muscle power and + + + align:start position:0% +muscle power and +the chances of embrace for this one are + + align:start position:0% +the chances of embrace for this one are + + + align:start position:0% +the chances of embrace for this one are +not as high as all the previous one but + + align:start position:0% +not as high as all the previous one but + + + align:start position:0% +not as high as all the previous one but +if it were to happen it would have the + + align:start position:0% +if it were to happen it would have the + + + align:start position:0% +if it were to happen it would have the +highest impact because right now there's + + align:start position:0% +highest impact because right now there's + + + align:start position:0% +highest impact because right now there's +billions of dollars being spent in the + + align:start position:0% +billions of dollars being spent in the + + + align:start position:0% +billions of dollars being spent in the +two extremes and if a small fraction + + align:start position:0% +two extremes and if a small fraction + + + align:start position:0% +two extremes and if a small fraction +were spent invested in that precious + + align:start position:0% +were spent invested in that precious + + + align:start position:0% +were spent invested in that precious +window of opportunity when you see the + + align:start position:0% +window of opportunity when you see the + + + align:start position:0% +window of opportunity when you see the +fuse getting close that time of effort + + align:start position:0% +fuse getting close that time of effort + + + align:start position:0% +fuse getting close that time of effort +can really have a very very high impact + + align:start position:0% +can really have a very very high impact + + + align:start position:0% +can really have a very very high impact +there's a link to a journal article that + + align:start position:0% +there's a link to a journal article that + + + align:start position:0% +there's a link to a journal article that +is should be very clear for students uh + + align:start position:0% +is should be very clear for students uh + + + align:start position:0% +is should be very clear for students uh +we also have some simpler readings and + + align:start position:0% +we also have some simpler readings and + + + align:start position:0% +we also have some simpler readings and +Jano and I have been engaged with it and + + align:start position:0% +Jano and I have been engaged with it and + + + align:start position:0% +Jano and I have been engaged with it and +are ready to help this is I insist the + + align:start position:0% +are ready to help this is I insist the + + + align:start position:0% +are ready to help this is I insist the +one that is intellectually most + + align:start position:0% +one that is intellectually most + + + align:start position:0% +one that is intellectually most +challenging but I think if you nail it + + align:start position:0% +challenging but I think if you nail it + + + align:start position:0% +challenging but I think if you nail it +it will also be the most + + align:start position:0% +it will also be the most + + + align:start position:0% +it will also be the most +rewarding + + align:start position:0% + + + + align:start position:0% + +questions questions this + + align:start position:0% +questions questions this + + + align:start position:0% +questions questions this +one so one thing when we first started + + align:start position:0% +one so one thing when we first started + + + align:start position:0% +one so one thing when we first started +um designing this class this was + + align:start position:0% +um designing this class this was + + + align:start position:0% +um designing this class this was +actually our the the problem that we + + align:start position:0% +actually our the the problem that we + + + align:start position:0% +actually our the the problem that we +were most interested in um mainly + + align:start position:0% +were most interested in um mainly + + + align:start position:0% +were most interested in um mainly +because the other problems we just + + align:start position:0% +because the other problems we just + + + align:start position:0% +because the other problems we just +didn't hadn't heard about since um the + + align:start position:0% +didn't hadn't heard about since um the + + + align:start position:0% +didn't hadn't heard about since um the +kalera was a recent um yes proposal that + + align:start position:0% +kalera was a recent um yes proposal that + + + align:start position:0% +kalera was a recent um yes proposal that +was asked for and Abola of course um + + align:start position:0% +was asked for and Abola of course um + + + align:start position:0% +was asked for and Abola of course um +very very recent as well um so if you + + align:start position:0% +very very recent as well um so if you + + + align:start position:0% +very very recent as well um so if you +really enjoyed some of the challenges + + align:start position:0% +really enjoyed some of the challenges + + + align:start position:0% +really enjoyed some of the challenges +from projects two and three and you + + align:start position:0% +from projects two and three and you + + + align:start position:0% +from projects two and three and you +really took on the the planning aspects + + align:start position:0% +really took on the the planning aspects + + + align:start position:0% +really took on the the planning aspects +the trade-offs as aspects of those two + + align:start position:0% +the trade-offs as aspects of those two + + + align:start position:0% +the trade-offs as aspects of those two +games um if you're looking at kind of + + align:start position:0% +games um if you're looking at kind of + + + align:start position:0% +games um if you're looking at kind of +trying to trying to communicate to + + align:start position:0% +trying to trying to communicate to + + + align:start position:0% +trying to trying to communicate to +another person how these kind of + + align:start position:0% +another person how these kind of + + + align:start position:0% +another person how these kind of +probabilities works this is probably a + + align:start position:0% +probabilities works this is probably a + + + align:start position:0% +probabilities works this is probably a +really good project you might be + + align:start position:0% +really good project you might be + + + align:start position:0% +really good project you might be +interested in + + align:start position:0% +interested in + + + align:start position:0% +interested in +and I should say also that working with + + align:start position:0% +and I should say also that working with + + + align:start position:0% +and I should say also that working with +a few MIT teams including the + + align:start position:0% +a few MIT teams including the + + + align:start position:0% +a few MIT teams including the +humanitarian response lab including the + + align:start position:0% +humanitarian response lab including the + + + align:start position:0% +humanitarian response lab including the +environmental engineering and we have + + align:start position:0% +environmental engineering and we have + + + align:start position:0% +environmental engineering and we have +two generations of three students plus + + align:start position:0% +two generations of three students plus + + + align:start position:0% +two generations of three students plus +one Professor go to Uganda to work on on + + align:start position:0% +one Professor go to Uganda to work on on + + + align:start position:0% +one Professor go to Uganda to work on on +making this happen for real we got + + align:start position:0% +making this happen for real we got + + + align:start position:0% +making this happen for real we got +German money to do it in Togo and in + + align:start position:0% +German money to do it in Togo and in + + + align:start position:0% +German money to do it in Togo and in +Uganda so it's beginning to happen but + + align:start position:0% +Uganda so it's beginning to happen but + + + align:start position:0% +Uganda so it's beginning to happen but +it's hard to explain because it's dry + + align:start position:0% +it's hard to explain because it's dry + + + align:start position:0% +it's hard to explain because it's dry +it's like explaining Insurance you know + + align:start position:0% +it's like explaining Insurance you know + + + align:start position:0% +it's like explaining Insurance you know +people get bored before they get it so + + align:start position:0% +people get bored before they get it so + + + align:start position:0% +people get bored before they get it so +media game can + + align:start position:0% +media game can + + + align:start position:0% +media game can +help + + align:start position:0% + + + + align:start position:0% + +motivate our team is working on forecast + + align:start position:0% +motivate our team is working on forecast + + + align:start position:0% +motivate our team is working on forecast +based financing so because we're about + + align:start position:0% +based financing so because we're about + + + align:start position:0% +based financing so because we're about +planning for disasters our game is + + align:start position:0% +planning for disasters our game is + + + align:start position:0% +planning for disasters our game is +pretty heavy on chance but what we want + + align:start position:0% +pretty heavy on chance but what we want + + + align:start position:0% +pretty heavy on chance but what we want +to teach the players to do is to use + + align:start position:0% +to teach the players to do is to use + + + align:start position:0% +to teach the players to do is to use +planning and forecasting in order to + + align:start position:0% +planning and forecasting in order to + + + align:start position:0% +planning and forecasting in order to +reduce the effects of that chance and + + align:start position:0% +reduce the effects of that chance and + + + align:start position:0% +reduce the effects of that chance and +sort of gain valuable skills in in uh + + align:start position:0% +sort of gain valuable skills in in uh + + + align:start position:0% +sort of gain valuable skills in in uh +mitigating that + + align:start position:0% + + + + align:start position:0% + +so basically if you + + align:start position:0% +so basically if you + + + align:start position:0% +so basically if you +have there's one two three four five + + align:start position:0% +have there's one two three four five + + + align:start position:0% +have there's one two three four five +testers plus let's say each team send + + align:start position:0% +testers plus let's say each team send + + + align:start position:0% +testers plus let's say each team send +out two two people to test other games + + align:start position:0% +out two two people to test other games + + + align:start position:0% +out two two people to test other games +um remember remember to rotate we're + + align:start position:0% +um remember remember to rotate we're + + + align:start position:0% +um remember remember to rotate we're +going to do this for about 20 minutes as + + align:start position:0% +going to do this for about 20 minutes as + + + align:start position:0% +going to do this for about 20 minutes as +long as it takes and then see where we + + align:start position:0% +long as it takes and then see where we + + + align:start position:0% +long as it takes and then see where we +are and do it again um to get some just + + align:start position:0% +are and do it again um to get some just + + + align:start position:0% +are and do it again um to get some just +quick testing and make sure that the + + align:start position:0% +quick testing and make sure that the + + + align:start position:0% +quick testing and make sure that the +five of us get to play um a good number + + align:start position:0% +five of us get to play um a good number + + + align:start position:0% +five of us get to play um a good number +of your games and give you some some + + align:start position:0% +of your games and give you some some + + + align:start position:0% +of your games and give you some some +feedback on that so remember if you're + + align:start position:0% +feedback on that so remember if you're + + + align:start position:0% +feedback on that so remember if you're +using digital if you're not if a + + align:start position:0% +using digital if you're not if a + + + align:start position:0% +using digital if you're not if a +computer is not being used for testing + + align:start position:0% +computer is not being used for testing + + + align:start position:0% +computer is not being used for testing +close it or make it look like it's not + + align:start position:0% +close it or make it look like it's not + + + align:start position:0% +close it or make it look like it's not +being used for testing by typing on + + align:start position:0% +being used for testing by typing on + + + align:start position:0% +being used for testing by typing on +it + + align:start position:0% +it + + + align:start position:0% +it +um all right let's get + + align:start position:0% + + + + align:start position:0% + +started I we forecast based funding the + + align:start position:0% +started I we forecast based funding the + + + align:start position:0% +started I we forecast based funding the +general idea behind our concept is that + + align:start position:0% +general idea behind our concept is that + + + align:start position:0% +general idea behind our concept is that +planning ahead for disasters is much + + align:start position:0% +planning ahead for disasters is much + + + align:start position:0% +planning ahead for disasters is much +better than trying to react to them so + + align:start position:0% +better than trying to react to them so + + + align:start position:0% +better than trying to react to them so +if you can have operating procedures or + + align:start position:0% +if you can have operating procedures or + + + align:start position:0% +if you can have operating procedures or +ways of planning for them and money + + align:start position:0% +ways of planning for them and money + + + align:start position:0% +ways of planning for them and money +allocated for that you can reduce loss + + align:start position:0% +allocated for that you can reduce loss + + + align:start position:0% +allocated for that you can reduce loss +of lives in the event of disasters we + + align:start position:0% +of lives in the event of disasters we + + + align:start position:0% +of lives in the event of disasters we +are actually between two prototypes + + align:start position:0% +are actually between two prototypes + + + align:start position:0% +are actually between two prototypes +right now that we're testing to try and + + align:start position:0% +right now that we're testing to try and + + + align:start position:0% +right now that we're testing to try and +get at the ideas the first one is a sort + + align:start position:0% +get at the ideas the first one is a sort + + + align:start position:0% +get at the ideas the first one is a sort +of higher level city-based simulation of + + align:start position:0% +of higher level city-based simulation of + + + align:start position:0% +of higher level city-based simulation of +cities at risk of disaster which you + + align:start position:0% +cities at risk of disaster which you + + + align:start position:0% +cities at risk of disaster which you +then have to fortify by training + + align:start position:0% +then have to fortify by training + + + align:start position:0% +then have to fortify by training +volunteers or preparing for upcoming + + align:start position:0% +volunteers or preparing for upcoming + + + align:start position:0% +volunteers or preparing for upcoming +disasters uh in order to prevent too + + align:start position:0% +disasters uh in order to prevent too + + + align:start position:0% +disasters uh in order to prevent too +much damage from happening to them uh + + align:start position:0% +much damage from happening to them uh + + + align:start position:0% +much damage from happening to them uh +one of the problems that we're seeing + + align:start position:0% +one of the problems that we're seeing + + + align:start position:0% +one of the problems that we're seeing +with the game is that it's kind of + + align:start position:0% +with the game is that it's kind of + + + align:start position:0% +with the game is that it's kind of +abstract and not as uh interactive for + + align:start position:0% +abstract and not as uh interactive for + + + align:start position:0% +abstract and not as uh interactive for +players to connect with but they are + + align:start position:0% +players to connect with but they are + + + align:start position:0% +players to connect with but they are +getting a good understanding of the idea + + align:start position:0% +getting a good understanding of the idea + + + align:start position:0% +getting a good understanding of the idea +of planning ahead yeah and so to try and + + align:start position:0% +of planning ahead yeah and so to try and + + + align:start position:0% +of planning ahead yeah and so to try and +address those issues we have a second + + align:start position:0% +address those issues we have a second + + + align:start position:0% +address those issues we have a second +prototype right now which is about um + + align:start position:0% +prototype right now which is about um + + + align:start position:0% +prototype right now which is about um +trying to actually like rescue + + align:start position:0% +trying to actually like rescue + + + align:start position:0% +trying to actually like rescue +volunteers in a flooding I uh rescue + + align:start position:0% +volunteers in a flooding I uh rescue + + + align:start position:0% +volunteers in a flooding I uh rescue +people in a flooding City and so that + + align:start position:0% +people in a flooding City and so that + + + align:start position:0% +people in a flooding City and so that +hits the other end of this scale where + + align:start position:0% +hits the other end of this scale where + + + align:start position:0% +hits the other end of this scale where +the player is told ahead of time this um + + align:start position:0% +the player is told ahead of time this um + + + align:start position:0% +the player is told ahead of time this um +This Disaster was planned for versus + + align:start position:0% +This Disaster was planned for versus + + + align:start position:0% +This Disaster was planned for versus +This Disaster was not planned for and + + align:start position:0% +This Disaster was not planned for and + + + align:start position:0% +This Disaster was not planned for and +the like the uh appropriate effects for + + align:start position:0% +the like the uh appropriate effects for + + + align:start position:0% +the like the uh appropriate effects for +each and then they have to rescue people + + align:start position:0% +each and then they have to rescue people + + + align:start position:0% +each and then they have to rescue people +under those two different conditions and + + align:start position:0% +under those two different conditions and + + + align:start position:0% +under those two different conditions and +then they get to directly compare like + + align:start position:0% +then they get to directly compare like + + + align:start position:0% +then they get to directly compare like +what the experience of is for like um + + align:start position:0% +what the experience of is for like um + + + align:start position:0% +what the experience of is for like um +acting in one circumstance versus the + + align:start position:0% +acting in one circumstance versus the + + + align:start position:0% +acting in one circumstance versus the +other over the next couple days we'll be + + align:start position:0% +other over the next couple days we'll be + + + align:start position:0% +other over the next couple days we'll be +looking at what we learn from both of + + align:start position:0% +looking at what we learn from both of + + + align:start position:0% +looking at what we learn from both of +them trying to either combine them or + + align:start position:0% +them trying to either combine them or + + + align:start position:0% +them trying to either combine them or +pull out the parts that we thought were + + align:start position:0% +pull out the parts that we thought were + + + align:start position:0% +pull out the parts that we thought were +really useful to make a + + align:start position:0% + + + + align:start position:0% + +comp this's the hard one yeah we ass + + align:start position:0% +comp this's the hard one yeah we ass + + + align:start position:0% +comp this's the hard one yeah we ass +this uh it was I think it was stated a + + align:start position:0% +this uh it was I think it was stated a + + + align:start position:0% +this uh it was I think it was stated a +couple of times that we should be + + align:start position:0% +couple of times that we should be + + + align:start position:0% +couple of times that we should be +looking at people like policy makers or + + align:start position:0% +looking at people like policy makers or + + + align:start position:0% +looking at people like policy makers or +donors in the sense of sort of people + + align:start position:0% +donors in the sense of sort of people + + + align:start position:0% +donors in the sense of sort of people +who would be allocating funds from + + align:start position:0% +who would be allocating funds from + + + align:start position:0% +who would be allocating funds from +governments or nonprofits things like + + align:start position:0% +governments or nonprofits things like + + + align:start position:0% +governments or nonprofits things like +that uh basically to make it clear that + + align:start position:0% +that uh basically to make it clear that + + + align:start position:0% +that uh basically to make it clear that +this type of planning ahead is a good + + align:start position:0% +this type of planning ahead is a good + + + align:start position:0% +this type of planning ahead is a good +idea + + align:start position:0% + + + + align:start position:0% + +um oh and what have you decided on + + align:start position:0% +um oh and what have you decided on + + + align:start position:0% +um oh and what have you decided on +technology yet or you still not there + + align:start position:0% +technology yet or you still not there + + + align:start position:0% +technology yet or you still not there +yet uh we're probably using + + align:start position:0% + + + + align:start position:0% + +phaser all right thank + + align:start position:0% +phaser all right thank + + + align:start position:0% +phaser all right thank +[Applause] + + align:start position:0% + + + + align:start position:0% + +you our game uh is called hello waves we + + align:start position:0% +you our game uh is called hello waves we + + + align:start position:0% +you our game uh is called hello waves we +don't have a title screen in yet but the + + align:start position:0% +don't have a title screen in yet but the + + + align:start position:0% +don't have a title screen in yet but the +idea is still forecast based + + align:start position:0% +idea is still forecast based + + + align:start position:0% +idea is still forecast based +financing uh so it's a little washed out + + align:start position:0% +financing uh so it's a little washed out + + + align:start position:0% +financing uh so it's a little washed out +on there but if you can see there these + + align:start position:0% +on there but if you can see there these + + + align:start position:0% +on there but if you can see there these +different these five different sand + + align:start position:0% +different these five different sand + + + align:start position:0% +different these five different sand +castles with workers associated with + + align:start position:0% +castles with workers associated with + + + align:start position:0% +castles with workers associated with +each and up here in the corner we have a + + align:start position:0% +each and up here in the corner we have a + + + align:start position:0% +each and up here in the corner we have a +forecast of what the water level will be + + align:start position:0% +forecast of what the water level will be + + + align:start position:0% +forecast of what the water level will be +like in a couple days this is the water + + align:start position:0% +like in a couple days this is the water + + + align:start position:0% +like in a couple days this is the water +level right here and throughout the game + + align:start position:0% +level right here and throughout the game + + + align:start position:0% +level right here and throughout the game +it'll rise and fall and the idea is not + + align:start position:0% +it'll rise and fall and the idea is not + + + align:start position:0% +it'll rise and fall and the idea is not +to let your workers uh get drowned by + + align:start position:0% +to let your workers uh get drowned by + + + align:start position:0% +to let your workers uh get drowned by +the rising water the other aspect of the + + align:start position:0% +the rising water the other aspect of the + + + align:start position:0% +the rising water the other aspect of the +game though is that you have a certain + + align:start position:0% +game though is that you have a certain + + + align:start position:0% +game though is that you have a certain +amount of supplies and whenever you move + + align:start position:0% +amount of supplies and whenever you move + + + align:start position:0% +amount of supplies and whenever you move +someone from their Castle in order to + + align:start position:0% +someone from their Castle in order to + + + align:start position:0% +someone from their Castle in order to +prevent them from getting drowned they + + align:start position:0% +prevent them from getting drowned they + + + align:start position:0% +prevent them from getting drowned they +will consume supplies from that stock + + align:start position:0% +will consume supplies from that stock + + + align:start position:0% +will consume supplies from that stock +and if you don't have enough supplies + + align:start position:0% +and if you don't have enough supplies + + + align:start position:0% +and if you don't have enough supplies +and they'll take + + align:start position:0% +and they'll take + + + align:start position:0% +and they'll take +damage + + align:start position:0% +damage + + + align:start position:0% +damage +so as you can see right now everybody's + + align:start position:0% +so as you can see right now everybody's + + + align:start position:0% +so as you can see right now everybody's +in their own castle if we click next + + align:start position:0% +in their own castle if we click next + + + align:start position:0% +in their own castle if we click next +turn the water level will change and + + align:start position:0% +turn the water level will change and + + + align:start position:0% +turn the water level will change and +we'll see that the forecast will update + + align:start position:0% +we'll see that the forecast will update + + + align:start position:0% +we'll see that the forecast will update +we have a range of values on this + + align:start position:0% +we have a range of values on this + + + align:start position:0% +we have a range of values on this +forecast uh a high prediction and a low + + align:start position:0% +forecast uh a high prediction and a low + + + align:start position:0% +forecast uh a high prediction and a low +prediction and if if you Mouse over any + + align:start position:0% +prediction and if if you Mouse over any + + + align:start position:0% +prediction and if if you Mouse over any +of the castles you'll see a red line + + align:start position:0% +of the castles you'll see a red line + + + align:start position:0% +of the castles you'll see a red line +appear on the forecast just to help you + + align:start position:0% +appear on the forecast just to help you + + + align:start position:0% +appear on the forecast just to help you +Orient what Heights uh are on the + + align:start position:0% +Orient what Heights uh are on the + + + align:start position:0% +Orient what Heights uh are on the +forecast or if you're looking at the + + align:start position:0% +forecast or if you're looking at the + + + align:start position:0% +forecast or if you're looking at the +forecast what it is in the real world so + + align:start position:0% +forecast what it is in the real world so + + + align:start position:0% +forecast what it is in the real world so +you can see the water move over these + + align:start position:0% +you can see the water move over these + + + align:start position:0% +you can see the water move over these +couple days right now the forecast is + + align:start position:0% +couple days right now the forecast is + + + align:start position:0% +couple days right now the forecast is +pretty low if we see that it's kind of + + align:start position:0% +pretty low if we see that it's kind of + + + align:start position:0% +pretty low if we see that it's kind of +getting close and we're worried about + + align:start position:0% +getting close and we're worried about + + + align:start position:0% +getting close and we're worried about +someone we can click and drag them to + + align:start position:0% +someone we can click and drag them to + + + align:start position:0% +someone we can click and drag them to +another castle and on the next turn + + align:start position:0% +another castle and on the next turn + + + align:start position:0% +another castle and on the next turn +they'll move + + align:start position:0% +they'll move + + + align:start position:0% +they'll move +over you can also click people to toggle + + align:start position:0% +over you can also click people to toggle + + + align:start position:0% +over you can also click people to toggle +between building and Gathering uh it's + + align:start position:0% +between building and Gathering uh it's + + + align:start position:0% +between building and Gathering uh it's +very hard to see the status text right + + align:start position:0% +very hard to see the status text right + + + align:start position:0% +very hard to see the status text right +now because it's small we threw that in + + align:start position:0% +now because it's small we threw that in + + + align:start position:0% +now because it's small we threw that in +quickly for right now uh but he is set + + align:start position:0% +quickly for right now uh but he is set + + + align:start position:0% +quickly for right now uh but he is set +to building and he these three are set + + align:start position:0% +to building and he these three are set + + + align:start position:0% +to building and he these three are set +to Gathering so we'll see that each turn + + align:start position:0% +to Gathering so we'll see that each turn + + + align:start position:0% +to Gathering so we'll see that each turn +these three will gather one Supply each + + align:start position:0% +these three will gather one Supply each + + + align:start position:0% +these three will gather one Supply each +this teddy bear will consume one so + + align:start position:0% +this teddy bear will consume one so + + + align:start position:0% +this teddy bear will consume one so +we'll see supplies go up by two and + + align:start position:0% +we'll see supplies go up by two and + + + align:start position:0% +we'll see supplies go up by two and +victory progress will go up by + + align:start position:0% +victory progress will go up by + + + align:start position:0% +victory progress will go up by +one what we have planned for the rest of + + align:start position:0% +one what we have planned for the rest of + + + align:start position:0% +one what we have planned for the rest of +the game is we've made a lot of progress + + align:start position:0% +the game is we've made a lot of progress + + + align:start position:0% +the game is we've made a lot of progress +in terms of the intuitiveness of our + + align:start position:0% +in terms of the intuitiveness of our + + + align:start position:0% +in terms of the intuitiveness of our +game once you understand it but right + + align:start position:0% +game once you understand it but right + + + align:start position:0% +game once you understand it but right +now there's a lot in the game that isn't + + align:start position:0% +now there's a lot in the game that isn't + + + align:start position:0% +now there's a lot in the game that isn't +explained from the get-go and so uh if I + + align:start position:0% +explained from the get-go and so uh if I + + + align:start position:0% +explained from the get-go and so uh if I +give that Spiel to anyone they can play + + align:start position:0% +give that Spiel to anyone they can play + + + align:start position:0% +give that Spiel to anyone they can play +the game fine and uh they do pretty well + + align:start position:0% +the game fine and uh they do pretty well + + + align:start position:0% +the game fine and uh they do pretty well +with it but if you just open up the game + + align:start position:0% +with it but if you just open up the game + + + align:start position:0% +with it but if you just open up the game +you're lost so a lot of our work is + + align:start position:0% +you're lost so a lot of our work is + + + align:start position:0% +you're lost so a lot of our work is +going to be on the UI of making things + + align:start position:0% +going to be on the UI of making things + + + align:start position:0% +going to be on the UI of making things +more self-evident and making sure that + + align:start position:0% +more self-evident and making sure that + + + align:start position:0% +more self-evident and making sure that +people can understand what's going on + + align:start position:0% +people can understand what's going on + + + align:start position:0% +people can understand what's going on +and what their actions will do without + + align:start position:0% +and what their actions will do without + + + align:start position:0% +and what their actions will do without +me having to stand there and tell + + align:start position:0% + + + + align:start position:0% + +them questions + + align:start position:0% + + + + align:start position:0% + +all right so I'm G to ask you again um + + align:start position:0% +all right so I'm G to ask you again um + + + align:start position:0% +all right so I'm G to ask you again um +what is your biggest risk going forward + + align:start position:0% +what is your biggest risk going forward + + + align:start position:0% +what is your biggest risk going forward +so I mean I think um in terms of our + + align:start position:0% +so I mean I think um in terms of our + + + align:start position:0% +so I mean I think um in terms of our +technical implementation we've already + + align:start position:0% +technical implementation we've already + + + align:start position:0% +technical implementation we've already +got good play tests of our work done and + + align:start position:0% +got good play tests of our work done and + + + align:start position:0% +got good play tests of our work done and +we have like all of our major Graphics + + align:start position:0% +we have like all of our major Graphics + + + align:start position:0% +we have like all of our major Graphics +in and things like that so I think our + + align:start position:0% +in and things like that so I think our + + + align:start position:0% +in and things like that so I think our +major risk going ahead is not being able + + align:start position:0% +major risk going ahead is not being able + + + align:start position:0% +major risk going ahead is not being able +to explain the game properly and so even + + align:start position:0% +to explain the game properly and so even + + + align:start position:0% +to explain the game properly and so even +if we have a finished product like it + + align:start position:0% +if we have a finished product like it + + + align:start position:0% +if we have a finished product like it +may may may still not be playable if we + + align:start position:0% +may may may still not be playable if we + + + align:start position:0% +may may may still not be playable if we +don't write good + + align:start position:0% +don't write good + + + align:start position:0% +don't write good +instructions all right so on that front + + align:start position:0% +instructions all right so on that front + + + align:start position:0% +instructions all right so on that front +think of uh + + align:start position:0% +think of uh + + + align:start position:0% +think of uh +incremental uh addition of features so + + align:start position:0% +incremental uh addition of features so + + + align:start position:0% +incremental uh addition of features so +the game begins with a super simple even + + align:start position:0% +the game begins with a super simple even + + + align:start position:0% +the game begins with a super simple even +maybe too boring choice but then a new + + align:start position:0% +maybe too boring choice but then a new + + + align:start position:0% +maybe too boring choice but then a new +Choice arrives so the the learning by + + align:start position:0% +Choice arrives so the the learning by + + + align:start position:0% +Choice arrives so the the learning by +playing can be staggered uh in a way + + align:start position:0% +playing can be staggered uh in a way + + + align:start position:0% +playing can be staggered uh in a way +that is that is intuitive good good luck + + align:start position:0% +that is that is intuitive good good luck + + + align:start position:0% +that is that is intuitive good good luck +to you and uh we'll talk more about uh + + align:start position:0% +to you and uh we'll talk more about uh + + + align:start position:0% +to you and uh we'll talk more about uh +choices later but okay I by I should say + + align:start position:0% +choices later but okay I by I should say + + + align:start position:0% +choices later but okay I by I should say +that this High versus low prediction is + + align:start position:0% +that this High versus low prediction is + + + align:start position:0% +that this High versus low prediction is +something that I wish scientists did + + align:start position:0% +something that I wish scientists did + + + align:start position:0% +something that I wish scientists did +like you're doing because most people + + align:start position:0% +like you're doing because most people + + + align:start position:0% +like you're doing because most people +say one value and then it's not that + + align:start position:0% +say one value and then it's not that + + + align:start position:0% +say one value and then it's not that +value here everyone does for good thank + + align:start position:0% +value here everyone does for good thank + + + align:start position:0% +value here everyone does for good thank +you thank + + align:start position:0% +you thank + + + align:start position:0% +you thank +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +you anyway come on + + align:start position:0% + + + + align:start position:0% + +down okay so it's a little light on + + align:start position:0% +down okay so it's a little light on + + + align:start position:0% +down okay so it's a little light on +there but our game is hello waves it's a + + align:start position:0% +there but our game is hello waves it's a + + + align:start position:0% +there but our game is hello waves it's a +game about forecast based financing that + + align:start position:0% +game about forecast based financing that + + + align:start position:0% +game about forecast based financing that +we're developing for the Red Cross the + + align:start position:0% +we're developing for the Red Cross the + + + align:start position:0% +we're developing for the Red Cross the +idea of forecast based financing is + + align:start position:0% +idea of forecast based financing is + + + align:start position:0% +idea of forecast based financing is +using the idea of forecast about the + + align:start position:0% +using the idea of forecast about the + + + align:start position:0% +using the idea of forecast about the +future in order to make decisions that + + align:start position:0% +future in order to make decisions that + + + align:start position:0% +future in order to make decisions that +are more effective than just reacting to + + align:start position:0% +are more effective than just reacting to + + + align:start position:0% +are more effective than just reacting to +disasters when they happen so uh I'd + + align:start position:0% +disasters when they happen so uh I'd + + + align:start position:0% +disasters when they happen so uh I'd +like to show you a playthrough of our + + align:start position:0% +like to show you a playthrough of our + + + align:start position:0% +like to show you a playthrough of our +game so uh I said hello waves here are + + align:start position:0% +game so uh I said hello waves here are + + + align:start position:0% +game so uh I said hello waves here are +the + + align:start position:0% +the + + + align:start position:0% +the +instructions uh we would have done a + + align:start position:0% +instructions uh we would have done a + + + align:start position:0% +instructions uh we would have done a +tutorial if we had enough time but this + + align:start position:0% +tutorial if we had enough time but this + + + align:start position:0% +tutorial if we had enough time but this +gets the idea across uh and uh designing + + align:start position:0% +gets the idea across uh and uh designing + + + align:start position:0% +gets the idea across uh and uh designing +a a good tutorial that actually teaches + + align:start position:0% +a a good tutorial that actually teaches + + + align:start position:0% +a a good tutorial that actually teaches +the player well is kind of hard to do in + + align:start position:0% +the player well is kind of hard to do in + + + align:start position:0% +the player well is kind of hard to do in +a a logical flow so we have these + + align:start position:0% +a a logical flow so we have these + + + align:start position:0% +a a logical flow so we have these +instructions that explain how to play + + align:start position:0% +instructions that explain how to play + + + align:start position:0% +instructions that explain how to play +what the point of the game is and uh a + + align:start position:0% +what the point of the game is and uh a + + + align:start position:0% +what the point of the game is and uh a +couple of tips about how the game + + align:start position:0% +couple of tips about how the game + + + align:start position:0% +couple of tips about how the game +works so if we go into the play screen + + align:start position:0% +works so if we go into the play screen + + + align:start position:0% +works so if we go into the play screen +you can see something similar to uh what + + align:start position:0% +you can see something similar to uh what + + + align:start position:0% +you can see something similar to uh what +we showed you a couple weeks ago where + + align:start position:0% +we showed you a couple weeks ago where + + + align:start position:0% +we showed you a couple weeks ago where +you have all these different toys at + + align:start position:0% +you have all these different toys at + + + align:start position:0% +you have all these different toys at +their castles and as you go through the + + align:start position:0% +their castles and as you go through the + + + align:start position:0% +their castles and as you go through the +days you'll see a forecast of what the + + align:start position:0% +days you'll see a forecast of what the + + + align:start position:0% +days you'll see a forecast of what the +water level's going to be at over time + + align:start position:0% +water level's going to be at over time + + + align:start position:0% +water level's going to be at over time +and so you can see that right now + + align:start position:0% +and so you can see that right now + + + align:start position:0% +and so you can see that right now +Gathering candy the water level will + + align:start position:0% +Gathering candy the water level will + + + align:start position:0% +Gathering candy the water level will +change this character is underwater and + + align:start position:0% +change this character is underwater and + + + align:start position:0% +change this character is underwater and +so he takes damage and so what you + + align:start position:0% +so he takes damage and so what you + + + align:start position:0% +so he takes damage and so what you +actually want to do is you want to move + + align:start position:0% +actually want to do is you want to move + + + align:start position:0% +actually want to do is you want to move +toys out of the water so that they don't + + align:start position:0% +toys out of the water so that they don't + + + align:start position:0% +toys out of the water so that they don't +get damaged however they can only move + + align:start position:0% +get damaged however they can only move + + + align:start position:0% +get damaged however they can only move +one Castle over at a time so because we + + align:start position:0% +one Castle over at a time so because we + + + align:start position:0% +one Castle over at a time so because we +didn't think ahead well enough we'll see + + align:start position:0% +didn't think ahead well enough we'll see + + + align:start position:0% +didn't think ahead well enough we'll see +that this truck will actually take + + align:start position:0% +that this truck will actually take + + + align:start position:0% +that this truck will actually take +damage on the next turn because he's + + align:start position:0% +damage on the next turn because he's + + + align:start position:0% +damage on the next turn because he's +underwater actually he ended up not + + align:start position:0% +underwater actually he ended up not + + + align:start position:0% +underwater actually he ended up not +underwater we got lucky there but + + align:start position:0% +underwater we got lucky there but + + + align:start position:0% +underwater we got lucky there but +theoretically he he would have and so as + + align:start position:0% +theoretically he he would have and so as + + + align:start position:0% +theoretically he he would have and so as +you go through it the end goal of the + + align:start position:0% +you go through it the end goal of the + + + align:start position:0% +you go through it the end goal of the +game is to build a castle uh and so + + align:start position:0% +game is to build a castle uh and so + + + align:start position:0% +game is to build a castle uh and so +every toy when they're home can either + + align:start position:0% +every toy when they're home can either + + + align:start position:0% +every toy when they're home can either +choose between Gathering candy to feed + + align:start position:0% +choose between Gathering candy to feed + + + align:start position:0% +choose between Gathering candy to feed +evacuated toys or building the castle to + + align:start position:0% +evacuated toys or building the castle to + + + align:start position:0% +evacuated toys or building the castle to +reach your end goal of the game and then + + align:start position:0% +reach your end goal of the game and then + + + align:start position:0% +reach your end goal of the game and then +the idea of the forecast is that you + + align:start position:0% +the idea of the forecast is that you + + + align:start position:0% +the idea of the forecast is that you +want to use the forecast in order to + + align:start position:0% +want to use the forecast in order to + + + align:start position:0% +want to use the forecast in order to +know how much candy you're going to need + + align:start position:0% +know how much candy you're going to need + + + align:start position:0% +know how much candy you're going to need +over the next couple days and to use it + + align:start position:0% +over the next couple days and to use it + + + align:start position:0% +over the next couple days and to use it +to know when you are going to need to + + align:start position:0% +to know when you are going to need to + + + align:start position:0% +to know when you are going to need to +evacuate various toys from their + + align:start position:0% +evacuate various toys from their + + + align:start position:0% +evacuate various toys from their +variously heighted + + align:start position:0% + + + + align:start position:0% + +homes so back to the presid + + align:start position:0% +homes so back to the presid + + + align:start position:0% +homes so back to the presid +presentation full + + align:start position:0% +presentation full + + + align:start position:0% +presentation full +screen so we had a couple of challenges + + align:start position:0% +screen so we had a couple of challenges + + + align:start position:0% +screen so we had a couple of challenges +in the design process the first and the + + align:start position:0% +in the design process the first and the + + + align:start position:0% +in the design process the first and the +major one is really that we were trying + + align:start position:0% +major one is really that we were trying + + + align:start position:0% +major one is really that we were trying +to teach about forecast-based + + align:start position:0% +to teach about forecast-based + + + align:start position:0% +to teach about forecast-based +financing which was a bit of an abstract + + align:start position:0% +financing which was a bit of an abstract + + + align:start position:0% +financing which was a bit of an abstract +topic it's a little different than just + + align:start position:0% +topic it's a little different than just + + + align:start position:0% +topic it's a little different than just +thinking long term because you have to + + align:start position:0% +thinking long term because you have to + + + align:start position:0% +thinking long term because you have to +use the idea of there's some information + + align:start position:0% +use the idea of there's some information + + + align:start position:0% +use the idea of there's some information +we know about the future that we want to + + align:start position:0% +we know about the future that we want to + + + align:start position:0% +we know about the future that we want to +use to make optimal decisions or at + + align:start position:0% +use to make optimal decisions or at + + + align:start position:0% +use to make optimal decisions or at +least decisions based on some idea of + + align:start position:0% +least decisions based on some idea of + + + align:start position:0% +least decisions based on some idea of +the risk that that's out there but we + + align:start position:0% +the risk that that's out there but we + + + align:start position:0% +the risk that that's out there but we +also wanted to avoid things like just + + align:start position:0% +also wanted to avoid things like just + + + align:start position:0% +also wanted to avoid things like just +pushing a button to win where you have + + align:start position:0% +pushing a button to win where you have + + + align:start position:0% +pushing a button to win where you have +all the information you ever need and + + align:start position:0% +all the information you ever need and + + + align:start position:0% +all the information you ever need and +there's just one option that you know + + align:start position:0% +there's just one option that you know + + + align:start position:0% +there's just one option that you know +you're going to pick every time and the + + align:start position:0% +you're going to pick every time and the + + + align:start position:0% +you're going to pick every time and the +game has no thought whatsoever and we + + align:start position:0% +game has no thought whatsoever and we + + + align:start position:0% +game has no thought whatsoever and we +also needed to think about how we are + + align:start position:0% +also needed to think about how we are + + + align:start position:0% +also needed to think about how we are +going to communicate the forecast to the + + align:start position:0% +going to communicate the forecast to the + + + align:start position:0% +going to communicate the forecast to the +player so that they could then use that + + align:start position:0% +player so that they could then use that + + + align:start position:0% +player so that they could then use that +to make + + align:start position:0% +to make + + + align:start position:0% +to make +decisions uh one of the problems that we + + align:start position:0% +decisions uh one of the problems that we + + + align:start position:0% +decisions uh one of the problems that we +also ran into related to this was that + + align:start position:0% +also ran into related to this was that + + + align:start position:0% +also ran into related to this was that +we focused a lot on the idea of forecast + + align:start position:0% +we focused a lot on the idea of forecast + + + align:start position:0% +we focused a lot on the idea of forecast +based financing as the topic and then + + align:start position:0% +based financing as the topic and then + + + align:start position:0% +based financing as the topic and then +tried to build a game built on top of + + align:start position:0% +tried to build a game built on top of + + + align:start position:0% +tried to build a game built on top of +that topic instead of building a game + + align:start position:0% +that topic instead of building a game + + + align:start position:0% +that topic instead of building a game +that use forecast based financing so + + align:start position:0% +that use forecast based financing so + + + align:start position:0% +that use forecast based financing so +that held us back a lot in the beginning + + align:start position:0% +that held us back a lot in the beginning + + + align:start position:0% +that held us back a lot in the beginning +when we were trying to come up with + + align:start position:0% +when we were trying to come up with + + + align:start position:0% +when we were trying to come up with +ideas we also had a really difficult + + align:start position:0% +ideas we also had a really difficult + + + align:start position:0% +ideas we also had a really difficult +initial targeted audience of policy + + align:start position:0% +initial targeted audience of policy + + + align:start position:0% +initial targeted audience of policy +makers 50 60 year-old uh government + + align:start position:0% +makers 50 60 year-old uh government + + + align:start position:0% +makers 50 60 year-old uh government +officials or people at NOS who are going + + align:start position:0% +officials or people at NOS who are going + + + align:start position:0% +officials or people at NOS who are going +to be using forecast to make decisions + + align:start position:0% +to be using forecast to make decisions + + + align:start position:0% +to be using forecast to make decisions +of some sort and it was supposed to + + align:start position:0% +of some sort and it was supposed to + + + align:start position:0% +of some sort and it was supposed to +teach them about how they can use + + align:start position:0% +teach them about how they can use + + + align:start position:0% +teach them about how they can use +forecast to make these decisions except + + align:start position:0% +forecast to make these decisions except + + + align:start position:0% +forecast to make these decisions except +this was a really difficult audience + + align:start position:0% +this was a really difficult audience + + + align:start position:0% +this was a really difficult audience +because they don't generally play games + + align:start position:0% +because they don't generally play games + + + align:start position:0% +because they don't generally play games +and uh they don't have a lot of time to + + align:start position:0% +and uh they don't have a lot of time to + + + align:start position:0% +and uh they don't have a lot of time to +learn about this kind of thing and so we + + align:start position:0% +learn about this kind of thing and so we + + + align:start position:0% +learn about this kind of thing and so we +couldn't really expect to get them to + + align:start position:0% +couldn't really expect to get them to + + + align:start position:0% +couldn't really expect to get them to +sit down for a long period of time and + + align:start position:0% +sit down for a long period of time and + + + align:start position:0% +sit down for a long period of time and +play around with our + + align:start position:0% +play around with our + + + align:start position:0% +play around with our +game in order to deal with these + + align:start position:0% +game in order to deal with these + + + align:start position:0% +game in order to deal with these +problems we came up with a couple + + align:start position:0% +problems we came up with a couple + + + align:start position:0% +problems we came up with a couple +Solutions the first thing was that we + + align:start position:0% +Solutions the first thing was that we + + + align:start position:0% +Solutions the first thing was that we +had no idea what kind of game would work + + align:start position:0% +had no idea what kind of game would work + + + align:start position:0% +had no idea what kind of game would work +or would make sense or anything like + + align:start position:0% +or would make sense or anything like + + + align:start position:0% +or would make sense or anything like +that so what we did is we just broke up + + align:start position:0% +that so what we did is we just broke up + + + align:start position:0% +that so what we did is we just broke up +into group into our team up into + + align:start position:0% +into group into our team up into + + + align:start position:0% +into group into our team up into +multiple groups and came up with a bunch + + align:start position:0% +multiple groups and came up with a bunch + + + align:start position:0% +multiple groups and came up with a bunch +of different prototypes uh on paper we + + align:start position:0% +of different prototypes uh on paper we + + + align:start position:0% +of different prototypes uh on paper we +had two different prototypes one that + + align:start position:0% +had two different prototypes one that + + + align:start position:0% +had two different prototypes one that +focused on the idea of managing a city + + align:start position:0% +focused on the idea of managing a city + + + align:start position:0% +focused on the idea of managing a city +and it's resources and its response to + + align:start position:0% +and it's resources and its response to + + + align:start position:0% +and it's resources and its response to +disasters versus focusing on individual + + align:start position:0% +disasters versus focusing on individual + + + align:start position:0% +disasters versus focusing on individual +people and how you're going to move them + + align:start position:0% +people and how you're going to move them + + + align:start position:0% +people and how you're going to move them +around to keep them safe from the + + align:start position:0% +around to keep them safe from the + + + align:start position:0% +around to keep them safe from the +disasters and then we went into a whole + + align:start position:0% +disasters and then we went into a whole + + + align:start position:0% +disasters and then we went into a whole +bunch of different digital prototypes + + align:start position:0% +bunch of different digital prototypes + + + align:start position:0% +bunch of different digital prototypes +one that was a text based game about + + align:start position:0% +one that was a text based game about + + + align:start position:0% +one that was a text based game about +managing a city we + + align:start position:0% +managing a city we + + + align:start position:0% +managing a city we +had one that looked like this where you + + align:start position:0% +had one that looked like this where you + + + align:start position:0% +had one that looked like this where you +had two different cities and you were + + align:start position:0% +had two different cities and you were + + + align:start position:0% +had two different cities and you were +specifying what workers were going to do + + align:start position:0% +specifying what workers were going to do + + + align:start position:0% +specifying what workers were going to do +or when they would leave the city in + + align:start position:0% +or when they would leave the city in + + + align:start position:0% +or when they would leave the city in +order to stay + + align:start position:0% +order to stay + + + align:start position:0% +order to stay +safe and then we would take the + + align:start position:0% +safe and then we would take the + + + align:start position:0% +safe and then we would take the +different ideas that we were learning + + align:start position:0% +different ideas that we were learning + + + align:start position:0% +different ideas that we were learning +from both of these prototypes combine + + align:start position:0% +from both of these prototypes combine + + + align:start position:0% +from both of these prototypes combine +them together take things out out and + + align:start position:0% +them together take things out out and + + + align:start position:0% +them together take things out out and +our final prototype actually uses ideas + + align:start position:0% +our final prototype actually uses ideas + + + align:start position:0% +our final prototype actually uses ideas +from all of + + align:start position:0% +from all of + + + align:start position:0% +from all of +these another solution that uh we kind + + align:start position:0% +these another solution that uh we kind + + + align:start position:0% +these another solution that uh we kind +of got lucky with is when Pablo came to + + align:start position:0% +of got lucky with is when Pablo came to + + + align:start position:0% +of got lucky with is when Pablo came to +play our game he told us that we + + align:start position:0% +play our game he told us that we + + + align:start position:0% +play our game he told us that we +actually shouldn't focus on the policy + + align:start position:0% +actually shouldn't focus on the policy + + + align:start position:0% +actually shouldn't focus on the policy +makers because he wasn't confident that + + align:start position:0% +makers because he wasn't confident that + + + align:start position:0% +makers because he wasn't confident that +he could actually get them to play the + + align:start position:0% +he could actually get them to play the + + + align:start position:0% +he could actually get them to play the +game and so we switched our Target to + + align:start position:0% +game and so we switched our Target to + + + align:start position:0% +game and so we switched our Target to +being grade schoolers which is why you + + align:start position:0% +being grade schoolers which is why you + + + align:start position:0% +being grade schoolers which is why you +saw the sort of cuty art with the beach + + align:start position:0% +saw the sort of cuty art with the beach + + + align:start position:0% +saw the sort of cuty art with the beach +and the toys this actually made it a lot + + align:start position:0% +and the toys this actually made it a lot + + + align:start position:0% +and the toys this actually made it a lot +easier for us because we could Target + + align:start position:0% +easier for us because we could Target + + + align:start position:0% +easier for us because we could Target +people who probably had some experience + + align:start position:0% +people who probably had some experience + + + align:start position:0% +people who probably had some experience +with games or at least wanted to do + + align:start position:0% +with games or at least wanted to do + + + align:start position:0% +with games or at least wanted to do +something fun and would be curious to + + align:start position:0% +something fun and would be curious to + + + align:start position:0% +something fun and would be curious to +learn about our + + align:start position:0% + + + + align:start position:0% + +topic so another um for our development + + align:start position:0% +topic so another um for our development + + + align:start position:0% +topic so another um for our development +process uh or I can just speak here + + align:start position:0% +process uh or I can just speak here + + + align:start position:0% +process uh or I can just speak here +right yeah you can speak right okay so + + align:start position:0% +right yeah you can speak right okay so + + + align:start position:0% +right yeah you can speak right okay so +another uh big issue we uh another set + + align:start position:0% +another uh big issue we uh another set + + + align:start position:0% +another uh big issue we uh another set +of challenges that we ran into was + + align:start position:0% +of challenges that we ran into was + + + align:start position:0% +of challenges that we ran into was +through our development process and so + + align:start position:0% +through our development process and so + + + align:start position:0% +through our development process and so +um we had initially issues with + + align:start position:0% +um we had initially issues with + + + align:start position:0% +um we had initially issues with +communication and facilitation our team + + align:start position:0% +communication and facilitation our team + + + align:start position:0% +communication and facilitation our team +had a wide variety of like uh + + align:start position:0% +had a wide variety of like uh + + + align:start position:0% +had a wide variety of like uh +experiences and backgrounds some were + + align:start position:0% +experiences and backgrounds some were + + + align:start position:0% +experiences and backgrounds some were +hardcore Gamers some mostly mobile + + align:start position:0% +hardcore Gamers some mostly mobile + + + align:start position:0% +hardcore Gamers some mostly mobile +Gamers and so there were initially a lot + + align:start position:0% +Gamers and so there were initially a lot + + + align:start position:0% +Gamers and so there were initially a lot +of disagreements on what level of game + + align:start position:0% +of disagreements on what level of game + + + align:start position:0% +of disagreements on what level of game +uh we wanted to create and like what + + align:start position:0% +uh we wanted to create and like what + + + align:start position:0% +uh we wanted to create and like what +sort of game casual versus hardcore that + + align:start position:0% +sort of game casual versus hardcore that + + + align:start position:0% +sort of game casual versus hardcore that +we wanted to create and so we needed to + + align:start position:0% +we wanted to create and so we needed to + + + align:start position:0% +we wanted to create and so we needed to +overcome like challenges of facilitation + + align:start position:0% +overcome like challenges of facilitation + + + align:start position:0% +overcome like challenges of facilitation +and communication within our team + + align:start position:0% +and communication within our team + + + align:start position:0% +and communication within our team +another major challenge in our devel + + align:start position:0% +another major challenge in our devel + + + align:start position:0% +another major challenge in our devel +vment process that we had to face came + + align:start position:0% +vment process that we had to face came + + + align:start position:0% +vment process that we had to face came +from our design issues where for a very + + align:start position:0% +from our design issues where for a very + + + align:start position:0% +from our design issues where for a very +long time we had kind of a vague vision + + align:start position:0% +long time we had kind of a vague vision + + + align:start position:0% +long time we had kind of a vague vision +of what to do we didn't know what kind + + align:start position:0% +of what to do we didn't know what kind + + + align:start position:0% +of what to do we didn't know what kind +of game we wanted to make and so we + + align:start position:0% +of game we wanted to make and so we + + + align:start position:0% +of game we wanted to make and so we +purposely tried to keep our game ideas + + align:start position:0% +purposely tried to keep our game ideas + + + align:start position:0% +purposely tried to keep our game ideas +vague as we built prototypes but then we + + align:start position:0% +vague as we built prototypes but then we + + + align:start position:0% +vague as we built prototypes but then we +ran into issues where um we would have + + align:start position:0% +ran into issues where um we would have + + + align:start position:0% +ran into issues where um we would have +Solutions but like no consensus on which + + align:start position:0% +Solutions but like no consensus on which + + + align:start position:0% +Solutions but like no consensus on which +solution was best and where we would um + + align:start position:0% +solution was best and where we would um + + + align:start position:0% +solution was best and where we would um +and where we went from long periods of + + align:start position:0% +and where we went from long periods of + + + align:start position:0% +and where we went from long periods of +time without having a clear direction of + + align:start position:0% +time without having a clear direction of + + + align:start position:0% +time without having a clear direction of +where we wanted our final game to + + align:start position:0% +where we wanted our final game to + + + align:start position:0% +where we wanted our final game to +be so um our solutions + + align:start position:0% +be so um our solutions + + + align:start position:0% +be so um our solutions +for uh the challenges proposed by the + + align:start position:0% +for uh the challenges proposed by the + + + align:start position:0% +for uh the challenges proposed by the +development were a team structure and so + + align:start position:0% +development were a team structure and so + + + align:start position:0% +development were a team structure and so +we structured our team + + align:start position:0% +we structured our team + + + align:start position:0% +we structured our team +Loosely uh into three sub teams a + + align:start position:0% +Loosely uh into three sub teams a + + + align:start position:0% +Loosely uh into three sub teams a +production sub team which would uh take + + align:start position:0% +production sub team which would uh take + + + align:start position:0% +production sub team which would uh take +care of uh production like the uh + + align:start position:0% +care of uh production like the uh + + + align:start position:0% +care of uh production like the uh +deliverables and making sure that the uh + + align:start position:0% +deliverables and making sure that the uh + + + align:start position:0% +deliverables and making sure that the uh +game ideas are being uh communicated + + align:start position:0% +game ideas are being uh communicated + + + align:start position:0% +game ideas are being uh communicated +properly a technical team which um + + align:start position:0% +properly a technical team which um + + + align:start position:0% +properly a technical team which um +worked primarily with the code and + + align:start position:0% +worked primarily with the code and + + + align:start position:0% +worked primarily with the code and +making sure the game got done and then a + + align:start position:0% +making sure the game got done and then a + + + align:start position:0% +making sure the game got done and then a +user experience team which handled art + + align:start position:0% +user experience team which handled art + + + align:start position:0% +user experience team which handled art +UI and uh sound and so we kept a + + align:start position:0% +UI and uh sound and so we kept a + + + align:start position:0% +UI and uh sound and so we kept a +flexible responsibility I uh we kept the + + align:start position:0% +flexible responsibility I uh we kept the + + + align:start position:0% +flexible responsibility I uh we kept the +responsibilities flexible so you know as + + align:start position:0% +responsibilities flexible so you know as + + + align:start position:0% +responsibilities flexible so you know as +team members got busy over the semester + + align:start position:0% +team members got busy over the semester + + + align:start position:0% +team members got busy over the semester +or as like changing conditions led to + + align:start position:0% +or as like changing conditions led to + + + align:start position:0% +or as like changing conditions led to +different people contributing um + + align:start position:0% +different people contributing um + + + align:start position:0% +different people contributing um +we kept UH responsibilities were able to + + align:start position:0% +we kept UH responsibilities were able to + + + align:start position:0% +we kept UH responsibilities were able to +easily flow between teams and team + + align:start position:0% +easily flow between teams and team + + + align:start position:0% +easily flow between teams and team +members and um additionally another idea + + align:start position:0% +members and um additionally another idea + + + align:start position:0% +members and um additionally another idea +we uh started with in the beginning was + + align:start position:0% +we uh started with in the beginning was + + + align:start position:0% +we uh started with in the beginning was +the idea of sub team leaders um which + + align:start position:0% +the idea of sub team leaders um which + + + align:start position:0% +the idea of sub team leaders um which +are the two people marked with the L's + + align:start position:0% +are the two people marked with the L's + + + align:start position:0% +are the two people marked with the L's +but that was an idea we later abandoned + + align:start position:0% +but that was an idea we later abandoned + + + align:start position:0% +but that was an idea we later abandoned +in favor of just having a more flexible + + align:start position:0% +in favor of just having a more flexible + + + align:start position:0% +in favor of just having a more flexible +team structure or flat team + + align:start position:0% +team structure or flat team + + + align:start position:0% +team structure or flat team +structure um another solution for + + align:start position:0% +structure um another solution for + + + align:start position:0% +structure um another solution for +helping our development process was the + + align:start position:0% +helping our development process was the + + + align:start position:0% +helping our development process was the +use of good code practices and I cannot + + align:start position:0% +use of good code practices and I cannot + + + align:start position:0% +use of good code practices and I cannot +emphasize enough that this really helped + + align:start position:0% +emphasize enough that this really helped + + + align:start position:0% +emphasize enough that this really helped +speed up our development because of we + + align:start position:0% +speed up our development because of we + + + align:start position:0% +speed up our development because of we +didn't run into trouble with code it was + + align:start position:0% +didn't run into trouble with code it was + + + align:start position:0% +didn't run into trouble with code it was +mostly with design so we used um we used + + align:start position:0% +mostly with design so we used um we used + + + align:start position:0% +mostly with design so we used um we used +dooman which is a JavaScript uh SC + + align:start position:0% +dooman which is a JavaScript uh SC + + + align:start position:0% +dooman which is a JavaScript uh SC +module system and basically it allowed + + align:start position:0% +module system and basically it allowed + + + align:start position:0% +module system and basically it allowed +our code to be interoperable we could + + align:start position:0% +our code to be interoperable we could + + + align:start position:0% +our code to be interoperable we could +write one module separately from another + + align:start position:0% +write one module separately from another + + + align:start position:0% +write one module separately from another +module so that solved a lot of issues + + align:start position:0% +module so that solved a lot of issues + + + align:start position:0% +module so that solved a lot of issues +with like dependencies or like um people + + align:start position:0% +with like dependencies or like um people + + + align:start position:0% +with like dependencies or like um people +working in parallel because it allowed + + align:start position:0% +working in parallel because it allowed + + + align:start position:0% +working in parallel because it allowed +people to you know work in parallel + + align:start position:0% +people to you know work in parallel + + + align:start position:0% +people to you know work in parallel +without overwriting each other's code um + + align:start position:0% +without overwriting each other's code um + + + align:start position:0% +without overwriting each other's code um +we also used good code practice with + + align:start position:0% +we also used good code practice with + + + align:start position:0% +we also used good code practice with +State machines and MVC which is mod view + + align:start position:0% +State machines and MVC which is mod view + + + align:start position:0% +State machines and MVC which is mod view +control and so we had a very you know + + align:start position:0% +control and so we had a very you know + + + align:start position:0% +control and so we had a very you know +objectoriented code very modular and + + align:start position:0% +objectoriented code very modular and + + + align:start position:0% +objectoriented code very modular and +when we did need to you know uh change + + align:start position:0% +when we did need to you know uh change + + + align:start position:0% +when we did need to you know uh change +our code rip it all out and put it back + + align:start position:0% +our code rip it all out and put it back + + + align:start position:0% +our code rip it all out and put it back +in it actually didn't turn out to be too + + align:start position:0% +in it actually didn't turn out to be too + + + align:start position:0% +in it actually didn't turn out to be too +painful because we just had to switch a + + align:start position:0% +painful because we just had to switch a + + + align:start position:0% +painful because we just had to switch a +couple objects around + + align:start position:0% +couple objects around + + + align:start position:0% +couple objects around +um all right and then one final solution + + align:start position:0% +um all right and then one final solution + + + align:start position:0% +um all right and then one final solution +that we used for uh for our development + + align:start position:0% +that we used for uh for our development + + + align:start position:0% +that we used for uh for our development +processes were slack and scrum so slack + + align:start position:0% +processes were slack and scrum so slack + + + align:start position:0% +processes were slack and scrum so slack +is like a modernized IRC chat room and + + align:start position:0% +is like a modernized IRC chat room and + + + align:start position:0% +is like a modernized IRC chat room and +it's very featur rich it has a lot of + + align:start position:0% +it's very featur rich it has a lot of + + + align:start position:0% +it's very featur rich it has a lot of +Integrations with uh GitHub and Google + + align:start position:0% +Integrations with uh GitHub and Google + + + align:start position:0% +Integrations with uh GitHub and Google +Drive and things like that and so that + + align:start position:0% +Drive and things like that and so that + + + align:start position:0% +Drive and things like that and so that +sort of realtime communication actually + + align:start position:0% +sort of realtime communication actually + + + align:start position:0% +sort of realtime communication actually +made it so that we didn't really have to + + align:start position:0% +made it so that we didn't really have to + + + align:start position:0% +made it so that we didn't really have to +meet outside of cloud too often uh we if + + align:start position:0% +meet outside of cloud too often uh we if + + + align:start position:0% +meet outside of cloud too often uh we if +someone was working we would just email + + align:start position:0% +someone was working we would just email + + + align:start position:0% +someone was working we would just email +out saying we're I'm on the slack and + + align:start position:0% +out saying we're I'm on the slack and + + + align:start position:0% +out saying we're I'm on the slack and +then people could meet on the slack and + + align:start position:0% +then people could meet on the slack and + + + align:start position:0% +then people could meet on the slack and +it was full featured enough like we + + align:start position:0% +it was full featured enough like we + + + align:start position:0% +it was full featured enough like we +could send attachments and things like + + align:start position:0% +could send attachments and things like + + + align:start position:0% +could send attachments and things like +that that yeah most of our communication + + align:start position:0% +that that yeah most of our communication + + + align:start position:0% +that that yeah most of our communication +in-person communication could be done in + + align:start position:0% +in-person communication could be done in + + + align:start position:0% +in-person communication could be done in +class and in class we adopted a uh sort + + align:start position:0% +class and in class we adopted a uh sort + + + align:start position:0% +class and in class we adopted a uh sort +of like daily scrum format where uh we + + align:start position:0% +of like daily scrum format where uh we + + + align:start position:0% +of like daily scrum format where uh we +simply said what we had done since the + + align:start position:0% +simply said what we had done since the + + + align:start position:0% +simply said what we had done since the +previous class and what our goals were + + align:start position:0% +previous class and what our goals were + + + align:start position:0% +previous class and what our goals were +uh until next + + align:start position:0% +uh until next + + + align:start position:0% +uh until next +class yeah so in the end though we did + + align:start position:0% +class yeah so in the end though we did + + + align:start position:0% +class yeah so in the end though we did +have to cut some features + + align:start position:0% +have to cut some features + + + align:start position:0% +have to cut some features +uh um these features mainly were the + + align:start position:0% +uh um these features mainly were the + + + align:start position:0% +uh um these features mainly were the +idea of multi again m a tutorial or + + align:start position:0% +idea of multi again m a tutorial or + + + align:start position:0% +idea of multi again m a tutorial or +multiple levels uh simply because there + + align:start position:0% +multiple levels uh simply because there + + + align:start position:0% +multiple levels uh simply because there +would just be too much content that we + + align:start position:0% +would just be too much content that we + + + align:start position:0% +would just be too much content that we +would need to play test in order to make + + align:start position:0% +would need to play test in order to make + + + align:start position:0% +would need to play test in order to make +sure that it like was a consistent + + align:start position:0% +sure that it like was a consistent + + + align:start position:0% +sure that it like was a consistent +quality and like got our message + + align:start position:0% +quality and like got our message + + + align:start position:0% +quality and like got our message +across um and also trying to to add more + + align:start position:0% +across um and also trying to to add more + + + align:start position:0% +across um and also trying to to add more +individuality to the uh to the toys that + + align:start position:0% +individuality to the uh to the toys that + + + align:start position:0% +individuality to the uh to the toys that +you saw um they have different Graphics + + align:start position:0% +you saw um they have different Graphics + + + align:start position:0% +you saw um they have different Graphics +but that's as much as we could do given + + align:start position:0% +but that's as much as we could do given + + + align:start position:0% +but that's as much as we could do given +the time + + align:start position:0% +the time + + + align:start position:0% +the time +constraints and so kind of just bring it + + align:start position:0% +constraints and so kind of just bring it + + + align:start position:0% +constraints and so kind of just bring it +back um and our worst three worst + + align:start position:0% +back um and our worst three worst + + + align:start position:0% +back um and our worst three worst +decisions um where first we spent a lot + + align:start position:0% +decisions um where first we spent a lot + + + align:start position:0% +decisions um where first we spent a lot +we did end up spending a lot of time on + + align:start position:0% +we did end up spending a lot of time on + + + align:start position:0% +we did end up spending a lot of time on +code and assets that never got used we + + align:start position:0% +code and assets that never got used we + + + align:start position:0% +code and assets that never got used we +maybe like + + align:start position:0% +maybe like + + + align:start position:0% +maybe like +use 10% of our final 10 to 20% of our + + align:start position:0% +use 10% of our final 10 to 20% of our + + + align:start position:0% +use 10% of our final 10 to 20% of our +final work in our final project actually + + align:start position:0% +final work in our final project actually + + + align:start position:0% +final work in our final project actually +maybe that is a bit uh Overkill but um + + align:start position:0% +maybe that is a bit uh Overkill but um + + + align:start position:0% +maybe that is a bit uh Overkill but um +okay maybe 30% of our final uh code and + + align:start position:0% +okay maybe 30% of our final uh code and + + + align:start position:0% +okay maybe 30% of our final uh code and +Assets in our final + + align:start position:0% +Assets in our final + + + align:start position:0% +Assets in our final +project um this really was due to uh + + align:start position:0% +project um this really was due to uh + + + align:start position:0% +project um this really was due to uh +this second bad decision that we kept + + align:start position:0% +this second bad decision that we kept + + + align:start position:0% +this second bad decision that we kept +the game and its direction too vague for + + align:start position:0% +the game and its direction too vague for + + + align:start position:0% +the game and its direction too vague for +too long we always were holding out that + + align:start position:0% +too long we always were holding out that + + + align:start position:0% +too long we always were holding out that +oh maybe we'll be able to come up with a + + align:start position:0% +oh maybe we'll be able to come up with a + + + align:start position:0% +oh maybe we'll be able to come up with a +better game idea or maybe we'll find + + align:start position:0% +better game idea or maybe we'll find + + + align:start position:0% +better game idea or maybe we'll find +some magic solution to how we can make + + align:start position:0% +some magic solution to how we can make + + + align:start position:0% +some magic solution to how we can make +for forecast based financing into a game + + align:start position:0% +for forecast based financing into a game + + + align:start position:0% +for forecast based financing into a game +and because of this mindset we spent + + align:start position:0% +and because of this mindset we spent + + + align:start position:0% +and because of this mindset we spent +probably the first half of the project + + align:start position:0% +probably the first half of the project + + + align:start position:0% +probably the first half of the project +like just staying too vague and that + + align:start position:0% +like just staying too vague and that + + + align:start position:0% +like just staying too vague and that +hurt us in the end because we spent so + + align:start position:0% +hurt us in the end because we spent so + + + align:start position:0% +hurt us in the end because we spent so +much time going in all these different + + align:start position:0% +much time going in all these different + + + align:start position:0% +much time going in all these different +directions and really um really the uh + + align:start position:0% +directions and really um really the uh + + + align:start position:0% +directions and really um really the uh +decision that kind of capture those + + align:start position:0% +decision that kind of capture those + + + align:start position:0% +decision that kind of capture those +first two though is the fact that we + + align:start position:0% +first two though is the fact that we + + + align:start position:0% +first two though is the fact that we +tried to make a game on top of forecast + + align:start position:0% +tried to make a game on top of forecast + + + align:start position:0% +tried to make a game on top of forecast +based financing so we had forecast based + + align:start position:0% +based financing so we had forecast based + + + align:start position:0% +based financing so we had forecast based +financing and we were like how can we + + align:start position:0% +financing and we were like how can we + + + align:start position:0% +financing and we were like how can we +skin this as a game whereas once we + + align:start position:0% +skin this as a game whereas once we + + + align:start position:0% +skin this as a game whereas once we +switched that mindset and thought let's + + align:start position:0% +switched that mindset and thought let's + + + align:start position:0% +switched that mindset and thought let's +have a game and how can we put forecast + + align:start position:0% +have a game and how can we put forecast + + + align:start position:0% +have a game and how can we put forecast +based financing into it I think uh that + + align:start position:0% +based financing into it I think uh that + + + align:start position:0% +based financing into it I think uh that +was the moment that we then came + + align:start position:0% +was the moment that we then came + + + align:start position:0% +was the moment that we then came +together as a team and really started + + align:start position:0% +together as a team and really started + + + align:start position:0% +together as a team and really started +making the final game that we + + align:start position:0% +making the final game that we + + + align:start position:0% +making the final game that we +wanted so our best + + align:start position:0% +wanted so our best + + + align:start position:0% +wanted so our best +decision um yeah so uh one of our best + + align:start position:0% +decision um yeah so uh one of our best + + + align:start position:0% +decision um yeah so uh one of our best +decisions was that we chose good tools + + align:start position:0% +decisions was that we chose good tools + + + align:start position:0% +decisions was that we chose good tools +at the beginning which meant that as we + + align:start position:0% +at the beginning which meant that as we + + + align:start position:0% +at the beginning which meant that as we +went through all these different digital + + align:start position:0% +went through all these different digital + + + align:start position:0% +went through all these different digital +prototypes we actually didn't have to + + align:start position:0% +prototypes we actually didn't have to + + + align:start position:0% +prototypes we actually didn't have to +completely rewrite our game we could + + align:start position:0% +completely rewrite our game we could + + + align:start position:0% +completely rewrite our game we could +pull out the way that workers worked in + + align:start position:0% +pull out the way that workers worked in + + + align:start position:0% +pull out the way that workers worked in +one game we could pull out the view that + + align:start position:0% +one game we could pull out the view that + + + align:start position:0% +one game we could pull out the view that +we were using in another game and then + + align:start position:0% +we were using in another game and then + + + align:start position:0% +we were using in another game and then +we could just combine them together and + + align:start position:0% +we could just combine them together and + + + align:start position:0% +we could just combine them together and +that allowed us to move quickly whenever + + align:start position:0% +that allowed us to move quickly whenever + + + align:start position:0% +that allowed us to move quickly whenever +we were changing our + + align:start position:0% +we were changing our + + + align:start position:0% +we were changing our +prototype we also weren't afraid to + + align:start position:0% +prototype we also weren't afraid to + + + align:start position:0% +prototype we also weren't afraid to +trust each other uh both in terms of + + align:start position:0% +trust each other uh both in terms of + + + align:start position:0% +trust each other uh both in terms of +what everyone was working on but also in + + align:start position:0% +what everyone was working on but also in + + + align:start position:0% +what everyone was working on but also in +terms of the decisions that we were + + align:start position:0% +terms of the decisions that we were + + + align:start position:0% +terms of the decisions that we were +making and so when we said that we had + + align:start position:0% +making and so when we said that we had + + + align:start position:0% +making and so when we said that we had +throw something out we all understood + + align:start position:0% +throw something out we all understood + + + align:start position:0% +throw something out we all understood +that it was for the best uh the good of + + align:start position:0% +that it was for the best uh the good of + + + align:start position:0% +that it was for the best uh the good of +the project and we we didn't have a lot + + align:start position:0% +the project and we we didn't have a lot + + + align:start position:0% +the project and we we didn't have a lot +of complaining or hurt feelings when + + align:start position:0% +of complaining or hurt feelings when + + + align:start position:0% +of complaining or hurt feelings when +something didn't get put in or when we + + align:start position:0% +something didn't get put in or when we + + + align:start position:0% +something didn't get put in or when we +decided to throw out our assets or code + + align:start position:0% +decided to throw out our assets or code + + + align:start position:0% +decided to throw out our assets or code +and when we got to the end we had been + + align:start position:0% +and when we got to the end we had been + + + align:start position:0% +and when we got to the end we had been +through enough of sort of this vagueness + + align:start position:0% +through enough of sort of this vagueness + + + align:start position:0% +through enough of sort of this vagueness +that we were all kind of frustrated with + + align:start position:0% +that we were all kind of frustrated with + + + align:start position:0% +that we were all kind of frustrated with +it and we realized that we had an idea + + align:start position:0% +it and we realized that we had an idea + + + align:start position:0% +it and we realized that we had an idea +that we all liked and we really got on + + align:start position:0% +that we all liked and we really got on + + + align:start position:0% +that we all liked and we really got on +board with it and made it happen once we + + align:start position:0% +board with it and made it happen once we + + + align:start position:0% +board with it and made it happen once we +started working on our final idea and we + + align:start position:0% +started working on our final idea and we + + + align:start position:0% +started working on our final idea and we +saw that it worked uh basically every + + align:start position:0% +saw that it worked uh basically every + + + align:start position:0% +saw that it worked uh basically every +decision from that point on was how do + + align:start position:0% +decision from that point on was how do + + + align:start position:0% +decision from that point on was how do +we make this game better uh and we were + + align:start position:0% +we make this game better uh and we were + + + align:start position:0% +we make this game better uh and we were +all on board with that + + align:start position:0% + + + + align:start position:0% + +Vision thank you any + + align:start position:0% + + + + align:start position:0% + +questions anyone in the audience have + + align:start position:0% +questions anyone in the audience have + + + align:start position:0% +questions anyone in the audience have +feedback for them first + + align:start position:0% +feedback for them first + + + align:start position:0% +feedback for them first +before you can't see that s very well + + align:start position:0% +before you can't see that s very well + + + align:start position:0% +before you can't see that s very well +yeah we'll have to make all of our + + align:start position:0% +yeah we'll have to make all of our + + + align:start position:0% +yeah we'll have to make all of our +slides darker yeah yellow and white yeah + + align:start position:0% +slides darker yeah yellow and white yeah + + + align:start position:0% +slides darker yeah yellow and white yeah +like the yellow and white on your on + + align:start position:0% +like the yellow and white on your on + + + align:start position:0% +like the yellow and white on your on +your early screen yeah I was doing this + + align:start position:0% +your early screen yeah I was doing this + + + align:start position:0% +your early screen yeah I was doing this +on yourp screen I realized that's the + + align:start position:0% +on yourp screen I realized that's the + + + align:start position:0% +on yourp screen I realized that's the +game not the the + + align:start position:0% +game not the the + + + align:start position:0% +game not the the +um presentation but wow it's also a + + align:start position:0% +um presentation but wow it's also a + + + align:start position:0% +um presentation but wow it's also a +little faded in the game itself it could + + align:start position:0% +little faded in the game itself it could + + + align:start position:0% +little faded in the game itself it could +be the display resolution you're using + + align:start position:0% +be the display resolution you're using + + + align:start position:0% +be the display resolution you're using +so after CL after we're done with + + align:start position:0% +so after CL after we're done with + + + align:start position:0% +so after CL after we're done with +everything try a different resolution + + align:start position:0% +everything try a different resolution + + + align:start position:0% +everything try a different resolution +see if it makes a difference yeah be + + align:start position:0% +see if it makes a difference yeah be + + + align:start position:0% +see if it makes a difference yeah be +great um the music in the game Deo was + + align:start position:0% +great um the music in the game Deo was + + + align:start position:0% +great um the music in the game Deo was +too high um it was overpowering your + + align:start position:0% +too high um it was overpowering your + + + align:start position:0% +too high um it was overpowering your +voice okay uh so you know I think you + + align:start position:0% +voice okay uh so you know I think you + + + align:start position:0% +voice okay uh so you know I think you +were almost hollering just to be able to + + align:start position:0% +were almost hollering just to be able to + + + align:start position:0% +were almost hollering just to be able to +be heard uh doesn't need to be that loud + + align:start position:0% +be heard uh doesn't need to be that loud + + + align:start position:0% +be heard uh doesn't need to be that loud +so you can just crank down the volume I + + align:start position:0% +so you can just crank down the volume I + + + align:start position:0% +so you can just crank down the volume I +or on the computer or on the controls + + align:start position:0% +or on the computer or on the controls + + + align:start position:0% +or on the computer or on the controls +over there um something that I that I + + align:start position:0% +over there um something that I that I + + + align:start position:0% +over there um something that I that I +had a question for uh you don't have to + + align:start position:0% +had a question for uh you don't have to + + + align:start position:0% +had a question for uh you don't have to +answer it today um but you might want to + + align:start position:0% +answer it today um but you might want to + + + align:start position:0% +answer it today um but you might want to +put it in your presentation was how long + + align:start position:0% +put it in your presentation was how long + + + align:start position:0% +put it in your presentation was how long +was the design of what you've what you + + align:start position:0% +was the design of what you've what you + + + align:start position:0% +was the design of what you've what you +eventually established on the table + + align:start position:0% +eventually established on the table + + + align:start position:0% +eventually established on the table +before you decided that this was the + + align:start position:0% +before you decided that this was the + + + align:start position:0% +before you decided that this was the +thing that you were going for right + + align:start position:0% +thing that you were going for right + + + align:start position:0% +thing that you were going for right +because I'm assuming it was one of your + + align:start position:0% +because I'm assuming it was one of your + + + align:start position:0% +because I'm assuming it was one of your +vague it came up during your vague idea + + align:start position:0% +vague it came up during your vague idea + + + align:start position:0% +vague it came up during your vague idea +phase + + align:start position:0% +phase + + + align:start position:0% +phase +and you're and you're implying that you + + align:start position:0% +and you're and you're implying that you + + + align:start position:0% +and you're and you're implying that you +were in that mode for too long but I + + align:start position:0% +were in that mode for too long but I + + + align:start position:0% +were in that mode for too long but I +don't know how long it was on the table + + align:start position:0% +don't know how long it was on the table + + + align:start position:0% +don't know how long it was on the table +or was it only something you figured out + + align:start position:0% +or was it only something you figured out + + + align:start position:0% +or was it only something you figured out +at the end of the vague idea phase um + + align:start position:0% +at the end of the vague idea phase um + + + align:start position:0% +at the end of the vague idea phase um +because you otherwise you wouldn't have + + align:start position:0% +because you otherwise you wouldn't have + + + align:start position:0% +because you otherwise you wouldn't have +been able to switch to this idea if it + + align:start position:0% +been able to switch to this idea if it + + + align:start position:0% +been able to switch to this idea if it +was not on the table in the first place + + align:start position:0% +was not on the table in the first place + + + align:start position:0% +was not on the table in the first place +um so uh and how did you decide this was + + align:start position:0% +um so uh and how did you decide this was + + + align:start position:0% +um so uh and how did you decide this was +it that that the San hustle game was + + align:start position:0% +it that that the San hustle game was + + + align:start position:0% +it that that the San hustle game was +going to be it um I understand I think + + align:start position:0% +going to be it um I understand I think + + + align:start position:0% +going to be it um I understand I think +you you very clearly explained the + + align:start position:0% +you you very clearly explained the + + + align:start position:0% +you you very clearly explained the +benefits of deciding this was it but how + + align:start position:0% +benefits of deciding this was it but how + + + align:start position:0% +benefits of deciding this was it but how +did you come to that conclusion sure was + + align:start position:0% +did you come to that conclusion sure was + + + align:start position:0% +did you come to that conclusion sure was +that stuff I want to hear more about but + + align:start position:0% +that stuff I want to hear more about but + + + align:start position:0% +that stuff I want to hear more about but +you don't have to answer it + + align:start position:0% +you don't have to answer it + + + align:start position:0% +you don't have to answer it +now yeah I might also um just a little + + align:start position:0% +now yeah I might also um just a little + + + align:start position:0% +now yeah I might also um just a little +bit speci you mentioned you spent too + + align:start position:0% +bit speci you mentioned you spent too + + + align:start position:0% +bit speci you mentioned you spent too +long on that design phase I wonder how + + align:start position:0% +long on that design phase I wonder how + + + align:start position:0% +long on that design phase I wonder how +long that was + + align:start position:0% +long that was + + + align:start position:0% +long that was +okay um you said Pablo switched your + + align:start position:0% +okay um you said Pablo switched your + + + align:start position:0% +okay um you said Pablo switched your +target audience for you um telling us + + align:start position:0% +target audience for you um telling us + + + align:start position:0% +target audience for you um telling us +whether that was because of the game + + align:start position:0% +whether that was because of the game + + + align:start position:0% +whether that was because of the game +that he saw or because of something else + + align:start position:0% +that he saw or because of something else + + + align:start position:0% +that he saw or because of something else +if you know that information throw it in + + align:start position:0% +if you know that information throw it in + + + align:start position:0% +if you know that information throw it in +there if you don't know that information + + align:start position:0% +there if you don't know that information + + + align:start position:0% +there if you don't know that information +that's fine + + align:start position:0% +that's fine + + + align:start position:0% +that's fine +um knowing why you you dropped the team + + align:start position:0% +um knowing why you you dropped the team + + + align:start position:0% +um knowing why you you dropped the team +lead you mentioned you you dropped it + + align:start position:0% +lead you mentioned you you dropped it + + + align:start position:0% +lead you mentioned you you dropped it +but you didn't exactly say why again + + align:start position:0% +but you didn't exactly say why again + + + align:start position:0% +but you didn't exactly say why again +really quick this is what it this we + + align:start position:0% +really quick this is what it this we + + + align:start position:0% +really quick this is what it this we +weren't getting blah out of it or the + + align:start position:0% +weren't getting blah out of it or the + + + align:start position:0% +weren't getting blah out of it or the +flexibility was more whatever um and + + align:start position:0% +flexibility was more whatever um and + + + align:start position:0% +flexibility was more whatever um and +then yeah to oh um defining your terms + + align:start position:0% +then yeah to oh um defining your terms + + + align:start position:0% +then yeah to oh um defining your terms +you're saying things like casual versus + + align:start position:0% +you're saying things like casual versus + + + align:start position:0% +you're saying things like casual versus +hardcore give a little bit of definition + + align:start position:0% +hardcore give a little bit of definition + + + align:start position:0% +hardcore give a little bit of definition +of what you what you mean by that um it + + align:start position:0% +of what you what you mean by that um it + + + align:start position:0% +of what you what you mean by that um it +means different things for everybody so + + align:start position:0% +means different things for everybody so + + + align:start position:0% +means different things for everybody so +what is your what is your use of that + + align:start position:0% +what is your what is your use of that + + + align:start position:0% +what is your what is your use of that +yeah I think you specifically said + + align:start position:0% +yeah I think you specifically said + + + align:start position:0% +yeah I think you specifically said +hardcore and mobile uh but there are + + align:start position:0% +hardcore and mobile uh but there are + + + align:start position:0% +hardcore and mobile uh but there are +hardcore mobile players out there so + + align:start position:0% +hardcore mobile players out there so + + + align:start position:0% +hardcore mobile players out there so +this is this is like and Casual can be + + align:start position:0% +this is this is like and Casual can be + + + align:start position:0% +this is this is like and Casual can be +considered a version of Hardcore just in + + align:start position:0% +considered a version of Hardcore just in + + + align:start position:0% +considered a version of Hardcore just in +a different way so just be really just + + align:start position:0% +a different way so just be really just + + + align:start position:0% +a different way so just be really just +be a little bit more clear about because + + align:start position:0% +be a little bit more clear about because + + + align:start position:0% +be a little bit more clear about because +I think you're talking about the target + + align:start position:0% +I think you're talking about the target + + + align:start position:0% +I think you're talking about the target +audience and the kind of players and the + + align:start position:0% +audience and the kind of players and the + + + align:start position:0% +audience and the kind of players and the +kind of games they might play so just be + + align:start position:0% +kind of games they might play so just be + + + align:start position:0% +kind of games they might play so just be +a little bit more more focused on what + + align:start position:0% +a little bit more more focused on what + + + align:start position:0% +a little bit more more focused on what +exactly you mean by + + align:start position:0% +exactly you mean by + + + align:start position:0% +exactly you mean by +that um that's it for me yeah so just a + + align:start position:0% +that um that's it for me yeah so just a + + + align:start position:0% +that um that's it for me yeah so just a +techical observation young man is not + + align:start position:0% +techical observation young man is not + + + align:start position:0% +techical observation young man is not +really a module frame it's just a system + + align:start position:0% +really a module frame it's just a system + + + align:start position:0% +really a module frame it's just a system +to generate a project and puts different + + align:start position:0% +to generate a project and puts different + + + align:start position:0% +to generate a project and puts different +Frameworks so + + align:start position:0% +Frameworks so + + + align:start position:0% +Frameworks so +just so that's terminology issue + + align:start position:0% +just so that's terminology issue + + + align:start position:0% +just so that's terminology issue +yeah CLE clear clearly it worked out for + + align:start position:0% +yeah CLE clear clearly it worked out for + + + align:start position:0% +yeah CLE clear clearly it worked out for +your team so we're not saying like don't + + align:start position:0% +your team so we're not saying like don't + + + align:start position:0% +your team so we're not saying like don't +mention your man it's clearly a good + + align:start position:0% +mention your man it's clearly a good + + + align:start position:0% +mention your man it's clearly a good +thing but just check your definition of + + align:start position:0% +thing but just check your definition of + + + align:start position:0% +thing but just check your definition of +what it of what it is because because + + align:start position:0% +what it of what it is because because + + + align:start position:0% +what it of what it is because because +it'll be more helpful for other people + + align:start position:0% +it'll be more helpful for other people + + + align:start position:0% +it'll be more helpful for other people +to understand what it is so that they + + align:start position:0% +to understand what it is so that they + + + align:start position:0% +to understand what it is so that they +can think about where they want to use + + align:start position:0% +can think about where they want to use + + + align:start position:0% +can think about where they want to use +it in the future oh actually so your + + align:start position:0% +it in the future oh actually so your + + + align:start position:0% +it in the future oh actually so your +demo you spent about three minutes doing + + align:start position:0% +demo you spent about three minutes doing + + + align:start position:0% +demo you spent about three minutes doing +it um we are going to have you have the + + align:start position:0% +it um we are going to have you have the + + + align:start position:0% +it um we are going to have you have the +a player from the audience play your + + align:start position:0% +a player from the audience play your + + + align:start position:0% +a player from the audience play your +your game live okay without do or + + align:start position:0% +your game live okay without do or + + + align:start position:0% +your game live okay without do or +without getting a lot of help you can + + align:start position:0% +without getting a lot of help you can + + + align:start position:0% +without getting a lot of help you can +talk over it you can after a while start + + align:start position:0% +talk over it you can after a while start + + + align:start position:0% +talk over it you can after a while start +helping them we need we want to see them + + align:start position:0% +helping them we need we want to see them + + + align:start position:0% +helping them we need we want to see them +at least just start playing it on their + + align:start position:0% +at least just start playing it on their + + + align:start position:0% +at least just start playing it on their +own decide when you're going to put that + + align:start position:0% +own decide when you're going to put that + + + align:start position:0% +own decide when you're going to put that +demo in you could actually combine them + + align:start position:0% +demo in you could actually combine them + + + align:start position:0% +demo in you could actually combine them +both together if you do it at the + + align:start position:0% +both together if you do it at the + + + align:start position:0% +both together if you do it at the +beginning or end um but if you do that + + align:start position:0% +beginning or end um but if you do that + + + align:start position:0% +beginning or end um but if you do that +give give the player a little bit of + + align:start position:0% +give give the player a little bit of + + + align:start position:0% +give give the player a little bit of +time before you start talking okay + + align:start position:0% +time before you start talking okay + + + align:start position:0% +time before you start talking okay +sure that's all I got great + + align:start position:0% + + + + align:start position:0% + +thanks snap come on down + + align:start position:0% + + + + align:start position:0% + +hello we are hello waves we're a game + + align:start position:0% +hello we are hello waves we're a game + + + align:start position:0% +hello we are hello waves we're a game +about forecasting uh specifically this + + align:start position:0% +about forecasting uh specifically this + + + align:start position:0% +about forecasting uh specifically this +idea called forecast based financing of + + align:start position:0% +idea called forecast based financing of + + + align:start position:0% +idea called forecast based financing of +using forecast to make decisions about + + align:start position:0% +using forecast to make decisions about + + + align:start position:0% +using forecast to make decisions about +possible disasters in the future and how + + align:start position:0% +possible disasters in the future and how + + + align:start position:0% +possible disasters in the future and how +to prepare for them we'd actually like + + align:start position:0% +to prepare for them we'd actually like + + + align:start position:0% +to prepare for them we'd actually like +to start with a playthrough of our game + + align:start position:0% +to start with a playthrough of our game + + + align:start position:0% +to start with a playthrough of our game +so if anybody would like to be a + + align:start position:0% +so if anybody would like to be a + + + align:start position:0% +so if anybody would like to be a +volunteer to to try it out a guest from + + align:start position:0% +volunteer to to try it out a guest from + + + align:start position:0% +volunteer to to try it out a guest from +not our class if one could please come + + align:start position:0% +not our class if one could please come + + + align:start position:0% +not our class if one could please come +down + + align:start position:0% + + + + align:start position:0% + +Andrew thank you for + + align:start position:0% +Andrew thank you for + + + align:start position:0% +Andrew thank you for +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +volunteering hi + + align:start position:0% +volunteering hi + + + align:start position:0% +volunteering hi +I'm you a + + align:start position:0% + + + + align:start position:0% + +chair not sure how got full screen but + + align:start position:0% +chair not sure how got full screen but + + + align:start position:0% +chair not sure how got full screen but +um anyways this is our game I'd + + align:start position:0% +um anyways this is our game I'd + + + align:start position:0% +um anyways this is our game I'd +recommend looking at the instructions + + align:start position:0% +recommend looking at the instructions + + + align:start position:0% +recommend looking at the instructions +first and reading through + + align:start position:0% + + + + align:start position:0% + +them and + + align:start position:0% +them and + + + align:start position:0% +them and +we'll keep the description minimal as + + align:start position:0% +we'll keep the description minimal as + + + align:start position:0% +we'll keep the description minimal as +you read through it just to to sure to + + align:start position:0% +you read through it just to to sure to + + + align:start position:0% +you read through it just to to sure to +show the player's initial reaction to + + align:start position:0% + + + + align:start position:0% + +it music + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay so yeah start + + align:start position:0% +okay so yeah start + + + align:start position:0% +okay so yeah start +again so as you can see our game as I + + align:start position:0% +again so as you can see our game as I + + + align:start position:0% +again so as you can see our game as I +said before you uh control some toys at + + align:start position:0% +said before you uh control some toys at + + + align:start position:0% +said before you uh control some toys at +uh on a day at the + + align:start position:0% + + + + align:start position:0% + +beach and so by dragging and dropping + + align:start position:0% +beach and so by dragging and dropping + + + align:start position:0% +beach and so by dragging and dropping +them between the castles you'll see that + + align:start position:0% +them between the castles you'll see that + + + align:start position:0% +them between the castles you'll see that +their status is Chang change and say + + align:start position:0% +their status is Chang change and say + + + align:start position:0% +their status is Chang change and say +that they want to move on their next + + align:start position:0% +that they want to move on their next + + + align:start position:0% +that they want to move on their next +turn or that they want to be collecting + + align:start position:0% +turn or that they want to be collecting + + + align:start position:0% +turn or that they want to be collecting +or that they're going to be collecting + + align:start position:0% +or that they're going to be collecting + + + align:start position:0% +or that they're going to be collecting +candy or anything like that and the game + + align:start position:0% +candy or anything like that and the game + + + align:start position:0% +candy or anything like that and the game +is turn-based + + align:start position:0% +is turn-based + + + align:start position:0% +is turn-based +so uh all the actions will resolve on + + align:start position:0% +so uh all the actions will resolve on + + + align:start position:0% +so uh all the actions will resolve on +the next turn + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +am I reading this + + align:start position:0% +am I reading this + + + align:start position:0% +am I reading this +right + + align:start position:0% +right + + + align:start position:0% +right +um yeah you can also access the the + + align:start position:0% +um yeah you can also access the the + + + align:start position:0% +um yeah you can also access the the +right corner + + align:start position:0% + + + + align:start position:0% + +and so uh when you go to the next to + + align:start position:0% +and so uh when you go to the next to + + + align:start position:0% +and so uh when you go to the next to +turn you'll see all the toys + + align:start position:0% +turn you'll see all the toys + + + align:start position:0% +turn you'll see all the toys +move uh as specified by the status + + align:start position:0% +move uh as specified by the status + + + align:start position:0% +move uh as specified by the status +bubble above their + + align:start position:0% +bubble above their + + + align:start position:0% +bubble above their +heads so to next turn + + align:start position:0% + + + + align:start position:0% + +next but unfortunately you'll find that + + align:start position:0% +next but unfortunately you'll find that + + + align:start position:0% +next but unfortunately you'll find that +when toys have been evacuated they're + + align:start position:0% +when toys have been evacuated they're + + + align:start position:0% +when toys have been evacuated they're +unhappy and need candy to survive so + + align:start position:0% +unhappy and need candy to survive so + + + align:start position:0% +unhappy and need candy to survive so +they'll all take + + align:start position:0% +they'll all take + + + align:start position:0% +they'll all take +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +damage they don't want + + align:start position:0% +damage they don't want + + + align:start position:0% +damage they don't want +to you can try returning them to their + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +homes and so you'll see that on this + + align:start position:0% +homes and so you'll see that on this + + + align:start position:0% +homes and so you'll see that on this +turn instead uh now they have their + + align:start position:0% +turn instead uh now they have their + + + align:start position:0% +turn instead uh now they have their +statuses set to Gathering candy except + + align:start position:0% +statuses set to Gathering candy except + + + align:start position:0% +statuses set to Gathering candy except +for the dun dump truck who's still + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +evacuated + + align:start position:0% +evacuated + + + align:start position:0% +evacuated +okay need to be + + align:start position:0% + + + + align:start position:0% + +evacuated + + align:start position:0% +evacuated + + + align:start position:0% +evacuated +exactly and so the the idea is that as + + align:start position:0% +exactly and so the the idea is that as + + + align:start position:0% +exactly and so the the idea is that as +the player plays through it they get + + align:start position:0% +the player plays through it they get + + + align:start position:0% +the player plays through it they get +better at understanding how to use the + + align:start position:0% +better at understanding how to use the + + + align:start position:0% +better at understanding how to use the +forecast to make decisions about the + + align:start position:0% +forecast to make decisions about the + + + align:start position:0% +forecast to make decisions about the +future uh both in terms of how much + + align:start position:0% +future uh both in terms of how much + + + align:start position:0% +future uh both in terms of how much +candy that they need to have stocked up + + align:start position:0% +candy that they need to have stocked up + + + align:start position:0% +candy that they need to have stocked up +in order to weather out the rising tides + + align:start position:0% +in order to weather out the rising tides + + + align:start position:0% +in order to weather out the rising tides +and also in terms of uh when they're + + align:start position:0% +and also in terms of uh when they're + + + align:start position:0% +and also in terms of uh when they're +going to need to move their workers out + + align:start position:0% +going to need to move their workers out + + + align:start position:0% +going to need to move their workers out +of their toys out of areas that are in + + align:start position:0% +of their toys out of areas that are in + + + align:start position:0% +of their toys out of areas that are in +danger they're going to be really imp + + align:start position:0% +danger they're going to be really imp + + + align:start position:0% +danger they're going to be really imp +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +um I think you have those two guys + + align:start position:0% +um I think you have those two guys + + + align:start position:0% +um I think you have those two guys +so is there a reminder of where they + + align:start position:0% +so is there a reminder of where they + + + align:start position:0% +so is there a reminder of where they +started yeah it's on the castle it's + + align:start position:0% +started yeah it's on the castle it's + + + align:start position:0% +started yeah it's on the castle it's +actually blocked out right now by by the + + align:start position:0% +actually blocked out right now by by the + + + align:start position:0% +actually blocked out right now by by the +toys in front of it but there's a little + + align:start position:0% +toys in front of it but there's a little + + + align:start position:0% +toys in front of it but there's a little +Shadow on there an + + align:start position:0% + + + + align:start position:0% + +imprint and because because he ran out + + align:start position:0% +imprint and because because he ran out + + + align:start position:0% +imprint and because because he ran out +of candy and then or actually sorry + + align:start position:0% +of candy and then or actually sorry + + + align:start position:0% +of candy and then or actually sorry +because he went to a place that was + + align:start position:0% +because he went to a place that was + + + align:start position:0% +because he went to a place that was +underwater uh he took too much damage + + align:start position:0% +underwater uh he took too much damage + + + align:start position:0% +underwater uh he took too much damage +and then was Swept Away by the waves + + align:start position:0% + + + + align:start position:0% + +and so on the forecast you can see that + + align:start position:0% +and so on the forecast you can see that + + + align:start position:0% +and so on the forecast you can see that +high water is coming for quite a while + + align:start position:0% +high water is coming for quite a while + + + align:start position:0% +high water is coming for quite a while +uh which is going to be a danger for the + + align:start position:0% +uh which is going to be a danger for the + + + align:start position:0% +uh which is going to be a danger for the +toys both in terms of possibly getting + + align:start position:0% +toys both in terms of possibly getting + + + align:start position:0% +toys both in terms of possibly getting +swept away and not having enough candy + + align:start position:0% +swept away and not having enough candy + + + align:start position:0% +swept away and not having enough candy +uh for all the toys that you're going to + + align:start position:0% +uh for all the toys that you're going to + + + align:start position:0% +uh for all the toys that you're going to +have to move out of the way + + align:start position:0% +have to move out of the way + + + align:start position:0% +have to move out of the way +[Music] + + align:start position:0% + + + + align:start position:0% + +oh he may be out of luck + + align:start position:0% +oh he may be out of luck + + + align:start position:0% +oh he may be out of luck +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah and when you've lost two toys you + + align:start position:0% +yeah and when you've lost two toys you + + + align:start position:0% +yeah and when you've lost two toys you +lose the + + align:start position:0% +lose the + + + align:start position:0% +lose the +game okay thank you for + + align:start position:0% +game okay thank you for + + + align:start position:0% +game okay thank you for +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +playing so that's hello + + align:start position:0% + + + + align:start position:0% + +waves + + align:start position:0% + + + + align:start position:0% + +so in our game we had uh a few + + align:start position:0% +so in our game we had uh a few + + + align:start position:0% +so in our game we had uh a few +challenges to overcome the first was + + align:start position:0% +challenges to overcome the first was + + + align:start position:0% +challenges to overcome the first was +that our game was based on forecast + + align:start position:0% +that our game was based on forecast + + + align:start position:0% +that our game was based on forecast +based financing which is a very abstract + + align:start position:0% +based financing which is a very abstract + + + align:start position:0% +based financing which is a very abstract +topic it's it's a pretty understandable + + align:start position:0% +topic it's it's a pretty understandable + + + align:start position:0% +topic it's it's a pretty understandable +idea of using information about the + + align:start position:0% +idea of using information about the + + + align:start position:0% +idea of using information about the +future and ideas of risk in order to + + align:start position:0% +future and ideas of risk in order to + + + align:start position:0% +future and ideas of risk in order to +decide where to allocate resources but + + align:start position:0% +decide where to allocate resources but + + + align:start position:0% +decide where to allocate resources but +it's still a bit abstract and building a + + align:start position:0% +it's still a bit abstract and building a + + + align:start position:0% +it's still a bit abstract and building a +game around it uh took a little bit of + + align:start position:0% +game around it uh took a little bit of + + + align:start position:0% +game around it uh took a little bit of +work it's useful to note that it's + + align:start position:0% +work it's useful to note that it's + + + align:start position:0% +work it's useful to note that it's +different than long-term planning it's + + align:start position:0% +different than long-term planning it's + + + align:start position:0% +different than long-term planning it's +not just thinking about what what will + + align:start position:0% +not just thinking about what what will + + + align:start position:0% +not just thinking about what what will +happen in the future you know building a + + align:start position:0% +happen in the future you know building a + + + align:start position:0% +happen in the future you know building a +dam to prevent water or things like that + + align:start position:0% +dam to prevent water or things like that + + + align:start position:0% +dam to prevent water or things like that +it's actually about using the + + align:start position:0% +it's actually about using the + + + align:start position:0% +it's actually about using the +information you have to make the best + + align:start position:0% +information you have to make the best + + + align:start position:0% +information you have to make the best +decision for events that may be upcoming + + align:start position:0% +decision for events that may be upcoming + + + align:start position:0% +decision for events that may be upcoming +in the semi near + + align:start position:0% +in the semi near + + + align:start position:0% +in the semi near +future we also wanted to avoid making a + + align:start position:0% +future we also wanted to avoid making a + + + align:start position:0% +future we also wanted to avoid making a +game that was overly preachy or + + align:start position:0% +game that was overly preachy or + + + align:start position:0% +game that was overly preachy or +simplified where it was clear H exactly + + align:start position:0% +simplified where it was clear H exactly + + + align:start position:0% +simplified where it was clear H exactly +how you're going to win and you could + + align:start position:0% +how you're going to win and you could + + + align:start position:0% +how you're going to win and you could +just basically push the forecast based + + align:start position:0% +just basically push the forecast based + + + align:start position:0% +just basically push the forecast based +financing button to win the game we want + + align:start position:0% +financing button to win the game we want + + + align:start position:0% +financing button to win the game we want +players to actually think and understand + + align:start position:0% +players to actually think and understand + + + align:start position:0% +players to actually think and understand +the concepts there instead of just you + + align:start position:0% +the concepts there instead of just you + + + align:start position:0% +the concepts there instead of just you +know coming up with the buzzword of + + align:start position:0% +know coming up with the buzzword of + + + align:start position:0% +know coming up with the buzzword of +forecast based financing and finally we + + align:start position:0% +forecast based financing and finally we + + + align:start position:0% +forecast based financing and finally we +had the challenge of actually + + align:start position:0% +had the challenge of actually + + + align:start position:0% +had the challenge of actually +communicating that forecast 2 players in + + align:start position:0% +communicating that forecast 2 players in + + + align:start position:0% +communicating that forecast 2 players in +a way that they would be able to + + align:start position:0% +a way that they would be able to + + + align:start position:0% +a way that they would be able to +understand and then make use of you + + align:start position:0% +understand and then make use of you + + + align:start position:0% +understand and then make use of you +could see in that game that we had water + + align:start position:0% +could see in that game that we had water + + + align:start position:0% +could see in that game that we had water +levels and it would show on the map and + + align:start position:0% +levels and it would show on the map and + + + align:start position:0% +levels and it would show on the map and +we found that players were pretty good + + align:start position:0% +we found that players were pretty good + + + align:start position:0% +we found that players were pretty good +at using that in order to decide to make + + align:start position:0% +at using that in order to decide to make + + + align:start position:0% +at using that in order to decide to make +decisions about what was going to happen + + align:start position:0% +decisions about what was going to happen + + + align:start position:0% +decisions about what was going to happen +in the future and how to allocate their + + align:start position:0% +in the future and how to allocate their + + + align:start position:0% +in the future and how to allocate their +resources the other big challenge that + + align:start position:0% +resources the other big challenge that + + + align:start position:0% +resources the other big challenge that +we had in the beginning was that our + + align:start position:0% +we had in the beginning was that our + + + align:start position:0% +we had in the beginning was that our +initial target audience was policy + + align:start position:0% +initial target audience was policy + + + align:start position:0% +initial target audience was policy +makers uh like for SNAP Pablo had come + + align:start position:0% +makers uh like for SNAP Pablo had come + + + align:start position:0% +makers uh like for SNAP Pablo had come +in and pitched us to this game idea and + + align:start position:0% +in and pitched us to this game idea and + + + align:start position:0% +in and pitched us to this game idea and +originally he had wanted us to build a + + align:start position:0% +originally he had wanted us to build a + + + align:start position:0% +originally he had wanted us to build a +game for policy makers that would help + + align:start position:0% +game for policy makers that would help + + + align:start position:0% +game for policy makers that would help +them understand the benefits of forecast + + align:start position:0% +them understand the benefits of forecast + + + align:start position:0% +them understand the benefits of forecast +based financing and therefore convinc + + align:start position:0% +based financing and therefore convinc + + + align:start position:0% +based financing and therefore convinc +them that they should develop policies + + align:start position:0% +them that they should develop policies + + + align:start position:0% +them that they should develop policies +that would uh give resources to plans + + align:start position:0% +that would uh give resources to plans + + + align:start position:0% +that would uh give resources to plans +based on forecast based + + align:start position:0% +based on forecast based + + + align:start position:0% +based on forecast based +financing so i' would like to take you + + align:start position:0% +financing so i' would like to take you + + + align:start position:0% +financing so i' would like to take you +through a couple of our prototypes just + + align:start position:0% +through a couple of our prototypes just + + + align:start position:0% +through a couple of our prototypes just +to show you the evolution and comment + + align:start position:0% +to show you the evolution and comment + + + align:start position:0% +to show you the evolution and comment +sort of on our + + align:start position:0% +sort of on our + + + align:start position:0% +sort of on our +process uh actually and to to preface + + align:start position:0% +process uh actually and to to preface + + + align:start position:0% +process uh actually and to to preface +that we had a lot of prototypes because + + align:start position:0% +that we had a lot of prototypes because + + + align:start position:0% +that we had a lot of prototypes because +because our idea was so abstract and + + align:start position:0% +because our idea was so abstract and + + + align:start position:0% +because our idea was so abstract and +because we weren't sure how to address + + align:start position:0% +because we weren't sure how to address + + + align:start position:0% +because we weren't sure how to address +our audience so we built a lot of + + align:start position:0% +our audience so we built a lot of + + + align:start position:0% +our audience so we built a lot of +prototypes to start with uh we had ideas + + align:start position:0% +prototypes to start with uh we had ideas + + + align:start position:0% +prototypes to start with uh we had ideas +that ranged across sort of levels of + + align:start position:0% +that ranged across sort of levels of + + + align:start position:0% +that ranged across sort of levels of +scope of what you controlled where you + + align:start position:0% +scope of what you controlled where you + + + align:start position:0% +scope of what you controlled where you +controlled entire cities or where you + + align:start position:0% +controlled entire cities or where you + + + align:start position:0% +controlled entire cities or where you +controlled individual workers and moved + + align:start position:0% +controlled individual workers and moved + + + align:start position:0% +controlled individual workers and moved +them around and then we would pull from + + align:start position:0% +them around and then we would pull from + + + align:start position:0% +them around and then we would pull from +all these different kinds of ideas what + + align:start position:0% +all these different kinds of ideas what + + + align:start position:0% +all these different kinds of ideas what +worked what didn't what did people + + align:start position:0% +worked what didn't what did people + + + align:start position:0% +worked what didn't what did people +understand what confused them and from + + align:start position:0% +understand what confused them and from + + + align:start position:0% +understand what confused them and from +that we got a really good idea of what + + align:start position:0% +that we got a really good idea of what + + + align:start position:0% +that we got a really good idea of what +concepts helped people understand the + + align:start position:0% +concepts helped people understand the + + + align:start position:0% +concepts helped people understand the +idea and brought them into this final + + align:start position:0% +idea and brought them into this final + + + align:start position:0% +idea and brought them into this final +game that we ended up with + + align:start position:0% +game that we ended up with + + + align:start position:0% +game that we ended up with +so the project started on October 15th + + align:start position:0% +so the project started on October 15th + + + align:start position:0% +so the project started on October 15th +and this was our first prototype it was + + align:start position:0% +and this was our first prototype it was + + + align:start position:0% +and this was our first prototype it was +a terminal based game where you had some + + align:start position:0% +a terminal based game where you had some + + + align:start position:0% +a terminal based game where you had some +kind of information about a future + + align:start position:0% +kind of information about a future + + + align:start position:0% +kind of information about a future +rainfall and then you had to type in + + align:start position:0% +rainfall and then you had to type in + + + align:start position:0% +rainfall and then you had to type in +your commands of how you control + + align:start position:0% +your commands of how you control + + + align:start position:0% +your commands of how you control +different + + align:start position:0% +different + + + align:start position:0% +different +cities this actually people found it fun + + align:start position:0% +cities this actually people found it fun + + + align:start position:0% +cities this actually people found it fun +but as you might expect the feedback + + align:start position:0% +but as you might expect the feedback + + + align:start position:0% +but as you might expect the feedback +wasn't very good and people didn't quite + + align:start position:0% +wasn't very good and people didn't quite + + + align:start position:0% +wasn't very good and people didn't quite +understand how to move forward with it + + align:start position:0% +understand how to move forward with it + + + align:start position:0% +understand how to move forward with it +it made it it put a lot of cognitive + + align:start position:0% +it made it it put a lot of cognitive + + + align:start position:0% +it made it it put a lot of cognitive +load on people so when we move forward + + align:start position:0% +load on people so when we move forward + + + align:start position:0% +load on people so when we move forward +we tried to give people more easily + + align:start position:0% +we tried to give people more easily + + + align:start position:0% +we tried to give people more easily +understandable actions to use but the + + align:start position:0% +understandable actions to use but the + + + align:start position:0% +understandable actions to use but the +problem with this game was that it was + + align:start position:0% +problem with this game was that it was + + + align:start position:0% +problem with this game was that it was +time based and it updated every second + + align:start position:0% +time based and it updated every second + + + align:start position:0% +time based and it updated every second +and so there were so many numbers flying + + align:start position:0% +and so there were so many numbers flying + + + align:start position:0% +and so there were so many numbers flying +at people that even MIT students who + + align:start position:0% +at people that even MIT students who + + + align:start position:0% +at people that even MIT students who +play tested it couldn't understand so we + + align:start position:0% +play tested it couldn't understand so we + + + align:start position:0% +play tested it couldn't understand so we +figured that people like policy makers + + align:start position:0% +figured that people like policy makers + + + align:start position:0% +figured that people like policy makers +who didn't have much experience with + + align:start position:0% +who didn't have much experience with + + + align:start position:0% +who didn't have much experience with +games really wouldn't be able to + + align:start position:0% +games really wouldn't be able to + + + align:start position:0% +games really wouldn't be able to +understand the game at all so instead we + + align:start position:0% +understand the game at all so instead we + + + align:start position:0% +understand the game at all so instead we +went to turn-based + + align:start position:0% +went to turn-based + + + align:start position:0% +went to turn-based +and that helped but at the same time + + align:start position:0% +and that helped but at the same time + + + align:start position:0% +and that helped but at the same time +it's tough to see on this projector but + + align:start position:0% +it's tough to see on this projector but + + + align:start position:0% +it's tough to see on this projector but +we have a forecast underneath that says + + align:start position:0% +we have a forecast underneath that says + + + align:start position:0% +we have a forecast underneath that says +how much rainfall is it expected and + + align:start position:0% +how much rainfall is it expected and + + + align:start position:0% +how much rainfall is it expected and +again that wasn't understandable to + + align:start position:0% +again that wasn't understandable to + + + align:start position:0% +again that wasn't understandable to +people cuz they couldn't understand what + + align:start position:0% +people cuz they couldn't understand what + + + align:start position:0% +people cuz they couldn't understand what +3 in of rainfall meant for their city + + align:start position:0% +3 in of rainfall meant for their city + + + align:start position:0% +3 in of rainfall meant for their city +and they couldn't understand how that + + align:start position:0% +and they couldn't understand how that + + + align:start position:0% +and they couldn't understand how that +contributed to a possible disaster at + + align:start position:0% +contributed to a possible disaster at + + + align:start position:0% +contributed to a possible disaster at +this point Pablo actually came by the + + align:start position:0% +this point Pablo actually came by the + + + align:start position:0% +this point Pablo actually came by the +class and played the game and then he + + align:start position:0% +class and played the game and then he + + + align:start position:0% +class and played the game and then he +told us that he wasn't even sure that he + + align:start position:0% +told us that he wasn't even sure that he + + + align:start position:0% +told us that he wasn't even sure that he +could get policy makers to play the game + + align:start position:0% +could get policy makers to play the game + + + align:start position:0% +could get policy makers to play the game +because they may not have enough time + + align:start position:0% +because they may not have enough time + + + align:start position:0% +because they may not have enough time +instead he wanted us to switch to grade + + align:start position:0% +instead he wanted us to switch to grade + + + align:start position:0% +instead he wanted us to switch to grade +schoolers because we could teach them + + align:start position:0% +schoolers because we could teach them + + + align:start position:0% +schoolers because we could teach them +something about forecast based financing + + align:start position:0% +something about forecast based financing + + + align:start position:0% +something about forecast based financing +and help them understand as they grew + + align:start position:0% +and help them understand as they grew + + + align:start position:0% +and help them understand as they grew +up and this was great for us because + + align:start position:0% +up and this was great for us because + + + align:start position:0% +up and this was great for us because +making a game that was serious easy for + + align:start position:0% +making a game that was serious easy for + + + align:start position:0% +making a game that was serious easy for +somebody who didn't have experience with + + align:start position:0% +somebody who didn't have experience with + + + align:start position:0% +somebody who didn't have experience with +games to play and also fun and engaging + + align:start position:0% +games to play and also fun and engaging + + + align:start position:0% +games to play and also fun and engaging +was too difficult for us actually so + + align:start position:0% +was too difficult for us actually so + + + align:start position:0% +was too difficult for us actually so +moving to grade schoolers was awesome he + + align:start position:0% +moving to grade schoolers was awesome he + + + align:start position:0% +moving to grade schoolers was awesome he +also suggested that we try to make the + + align:start position:0% +also suggested that we try to make the + + + align:start position:0% +also suggested that we try to make the +idea of rainfall or water levels more + + align:start position:0% +idea of rainfall or water levels more + + + align:start position:0% +idea of rainfall or water levels more +visceral and that's when we came upon + + align:start position:0% +visceral and that's when we came upon + + + align:start position:0% +visceral and that's when we came upon +this idea of the rising Waters whenever + + align:start position:0% +this idea of the rising Waters whenever + + + align:start position:0% +this idea of the rising Waters whenever +players looked at this they instantly + + align:start position:0% +players looked at this they instantly + + + align:start position:0% +players looked at this they instantly +understood the concept of the game the + + align:start position:0% +understood the concept of the game the + + + align:start position:0% +understood the concept of the game the +feedback might not be there the + + align:start position:0% +feedback might not be there the + + + align:start position:0% +feedback might not be there the +Beautiful You might not be there but the + + align:start position:0% +Beautiful You might not be there but the + + + align:start position:0% +Beautiful You might not be there but the +idea of having cities with workers in + + align:start position:0% +idea of having cities with workers in + + + align:start position:0% +idea of having cities with workers in +them and a rising water level coming + + align:start position:0% +them and a rising water level coming + + + align:start position:0% +them and a rising water level coming +towards them everybody understood that + + align:start position:0% +towards them everybody understood that + + + align:start position:0% +towards them everybody understood that +and it made it a lot easier for players + + align:start position:0% +and it made it a lot easier for players + + + align:start position:0% +and it made it a lot easier for players +to reason about the game from there we + + align:start position:0% +to reason about the game from there we + + + align:start position:0% +to reason about the game from there we +added things like nicer art better + + align:start position:0% +added things like nicer art better + + + align:start position:0% +added things like nicer art better +feedback which you can't quite see in + + align:start position:0% +feedback which you can't quite see in + + + align:start position:0% +feedback which you can't quite see in +the static picture uh more improvements + + align:start position:0% +the static picture uh more improvements + + + align:start position:0% +the static picture uh more improvements +to how the forecast worked and uh + + align:start position:0% +to how the forecast worked and uh + + + align:start position:0% +to how the forecast worked and uh +eventually we ended up with our final + + align:start position:0% +eventually we ended up with our final + + + align:start position:0% +eventually we ended up with our final +version + + align:start position:0% +version + + + align:start position:0% +version +today uh yeah so to talk a little bit + + align:start position:0% +today uh yeah so to talk a little bit + + + align:start position:0% +today uh yeah so to talk a little bit +about our actual development process so + + align:start position:0% +about our actual development process so + + + align:start position:0% +about our actual development process so +our team was structured into three main + + align:start position:0% +our team was structured into three main + + + align:start position:0% +our team was structured into three main +sub teams production which was in charge + + align:start position:0% +sub teams production which was in charge + + + align:start position:0% +sub teams production which was in charge +of managerial roles deliverables and + + align:start position:0% +of managerial roles deliverables and + + + align:start position:0% +of managerial roles deliverables and +play testing and so there was a shared + + align:start position:0% +play testing and so there was a shared + + + align:start position:0% +play testing and so there was a shared +responsibility of like um their uh + + align:start position:0% +responsibility of like um their uh + + + align:start position:0% +responsibility of like um their uh +technical team which was in charge of + + align:start position:0% +technical team which was in charge of + + + align:start position:0% +technical team which was in charge of +the bulk of the uh coding work and a + + align:start position:0% +the bulk of the uh coding work and a + + + align:start position:0% +the bulk of the uh coding work and a +user experience team which would be in + + align:start position:0% +user experience team which would be in + + + align:start position:0% +user experience team which would be in +charge of assets UI design and UI design + + align:start position:0% +charge of assets UI design and UI design + + + align:start position:0% +charge of assets UI design and UI design +um we also initially invisioned like a + + align:start position:0% +um we also initially invisioned like a + + + align:start position:0% +um we also initially invisioned like a +sub team leaders where we'd be kind of + + align:start position:0% +sub team leaders where we'd be kind of + + + align:start position:0% +sub team leaders where we'd be kind of +communicating through those but uh we + + align:start position:0% +communicating through those but uh we + + + align:start position:0% +communicating through those but uh we +found the concept kind of redundant and + + align:start position:0% +found the concept kind of redundant and + + + align:start position:0% +found the concept kind of redundant and +so we worked pretty much with like a + + align:start position:0% +so we worked pretty much with like a + + + align:start position:0% +so we worked pretty much with like a +flat structure between the three + + align:start position:0% +flat structure between the three + + + align:start position:0% +flat structure between the three +teams um so from the beginning we + + align:start position:0% +teams um so from the beginning we + + + align:start position:0% +teams um so from the beginning we +encouraged good coding practice and so + + align:start position:0% +encouraged good coding practice and so + + + align:start position:0% +encouraged good coding practice and so +we used uh good tools available to us + + align:start position:0% +we used uh good tools available to us + + + align:start position:0% +we used uh good tools available to us +one of these is um Yen which is a + + align:start position:0% +one of these is um Yen which is a + + + align:start position:0% +one of these is um Yen which is a +JavaScript scaffolding framework um and + + align:start position:0% +JavaScript scaffolding framework um and + + + align:start position:0% +JavaScript scaffolding framework um and +this helped us out a lot by basically + + align:start position:0% +this helped us out a lot by basically + + + align:start position:0% +this helped us out a lot by basically +automating a lot of our JavaScript tasks + + align:start position:0% +automating a lot of our JavaScript tasks + + + align:start position:0% +automating a lot of our JavaScript tasks +and making our code + + align:start position:0% +and making our code + + + align:start position:0% +and making our code +modular um we also used pH State machine + + align:start position:0% +modular um we also used pH State machine + + + align:start position:0% +modular um we also used pH State machine +which is this kind of kind of badly + + align:start position:0% +which is this kind of kind of badly + + + align:start position:0% +which is this kind of kind of badly +documented like new Fe feature in the + + align:start position:0% +documented like new Fe feature in the + + + align:start position:0% +documented like new Fe feature in the +phaser game engine which was the uh + + align:start position:0% +phaser game engine which was the uh + + + align:start position:0% +phaser game engine which was the uh +JavaScript game engine that we used um + + align:start position:0% +JavaScript game engine that we used um + + + align:start position:0% +JavaScript game engine that we used um +it's a bit badly documented so um but it + + align:start position:0% +it's a bit badly documented so um but it + + + align:start position:0% +it's a bit badly documented so um but it +did save us a lot of headaches and once + + align:start position:0% +did save us a lot of headaches and once + + + align:start position:0% +did save us a lot of headaches and once +we figured that out that was uh proved + + align:start position:0% +we figured that out that was uh proved + + + align:start position:0% +we figured that out that was uh proved +immensely helpful and we also used MVC + + align:start position:0% +immensely helpful and we also used MVC + + + align:start position:0% +immensely helpful and we also used MVC +which is a computer uh computer software + + align:start position:0% +which is a computer uh computer software + + + align:start position:0% +which is a computer uh computer software +engineering term standing for model view + + align:start position:0% +engineering term standing for model view + + + align:start position:0% +engineering term standing for model view +controller and again um by by + + align:start position:0% +controller and again um by by + + + align:start position:0% +controller and again um by by +encouraging these good coding practices + + align:start position:0% +encouraging these good coding practices + + + align:start position:0% +encouraging these good coding practices +we reduced dependencies and uh made sure + + align:start position:0% +we reduced dependencies and uh made sure + + + align:start position:0% +we reduced dependencies and uh made sure +that our team was + + align:start position:0% +that our team was + + + align:start position:0% +that our team was +productive um in terms of communication + + align:start position:0% +productive um in terms of communication + + + align:start position:0% +productive um in terms of communication +we also similar to snap use slack which + + align:start position:0% +we also similar to snap use slack which + + + align:start position:0% +we also similar to snap use slack which +is kind of like a modernized chat room + + align:start position:0% +is kind of like a modernized chat room + + + align:start position:0% +is kind of like a modernized chat room +it's very featur rich and so you can + + align:start position:0% +it's very featur rich and so you can + + + align:start position:0% +it's very featur rich and so you can +share files Channel and things like that + + align:start position:0% +share files Channel and things like that + + + align:start position:0% +share files Channel and things like that +and we also use the idea of the uh daily + + align:start position:0% +and we also use the idea of the uh daily + + + align:start position:0% +and we also use the idea of the uh daily +scrum we implemented it in class and we + + align:start position:0% +scrum we implemented it in class and we + + + align:start position:0% +scrum we implemented it in class and we +would say what we had done that class + + align:start position:0% +would say what we had done that class + + + align:start position:0% +would say what we had done that class +what we would be doing um and what we + + align:start position:0% +what we would be doing um and what we + + + align:start position:0% +what we would be doing um and what we +wanted to do uh until next + + align:start position:0% +wanted to do uh until next + + + align:start position:0% +wanted to do uh until next +class and so now the major challenges + + align:start position:0% +class and so now the major challenges + + + align:start position:0% +class and so now the major challenges +that we faced during the development + + align:start position:0% +that we faced during the development + + + align:start position:0% +that we faced during the development +process though um where that our team + + align:start position:0% +process though um where that our team + + + align:start position:0% +process though um where that our team +members came from very different + + align:start position:0% +members came from very different + + + align:start position:0% +members came from very different +backgrounds and had very different + + align:start position:0% +backgrounds and had very different + + + align:start position:0% +backgrounds and had very different +preferences about games you know some of + + align:start position:0% +preferences about games you know some of + + + align:start position:0% +preferences about games you know some of +our some of our team members were + + align:start position:0% +our some of our team members were + + + align:start position:0% +our some of our team members were +hardcore Starcraft players and you know + + align:start position:0% +hardcore Starcraft players and you know + + + align:start position:0% +hardcore Starcraft players and you know +very good at RTS games while other + + align:start position:0% +very good at RTS games while other + + + align:start position:0% +very good at RTS games while other +members of our team preferred like a + + align:start position:0% +members of our team preferred like a + + + align:start position:0% +members of our team preferred like a +more laid-back you know mobile game + + align:start position:0% +more laid-back you know mobile game + + + align:start position:0% +more laid-back you know mobile game +Fruit Ninja kind of approach and so + + align:start position:0% +Fruit Ninja kind of approach and so + + + align:start position:0% +Fruit Ninja kind of approach and so +trying to like mediate those two + + align:start position:0% +trying to like mediate those two + + + align:start position:0% +trying to like mediate those two +viewpoints and trying to create a game + + align:start position:0% +viewpoints and trying to create a game + + + align:start position:0% +viewpoints and trying to create a game +that would engage both uh both types of + + align:start position:0% +that would engage both uh both types of + + + align:start position:0% +that would engage both uh both types of +Gamers was a challenge that we had to + + align:start position:0% +Gamers was a challenge that we had to + + + align:start position:0% +Gamers was a challenge that we had to +overcome um and so another big challenge + + align:start position:0% +overcome um and so another big challenge + + + align:start position:0% +overcome um and so another big challenge +that we had in our development process + + align:start position:0% +that we had in our development process + + + align:start position:0% +that we had in our development process +you know as you saw through our uh uh + + align:start position:0% +you know as you saw through our uh uh + + + align:start position:0% +you know as you saw through our uh uh +progression through our different + + align:start position:0% +progression through our different + + + align:start position:0% +progression through our different +prototypes was that our Direction was + + align:start position:0% +prototypes was that our Direction was + + + align:start position:0% +prototypes was that our Direction was +not very clear until about halfway + + align:start position:0% +not very clear until about halfway + + + align:start position:0% +not very clear until about halfway +through the project and so partially + + align:start position:0% +through the project and so partially + + + align:start position:0% +through the project and so partially +because we had uh different ideas on + + align:start position:0% +because we had uh different ideas on + + + align:start position:0% +because we had uh different ideas on +what the game should look like and also + + align:start position:0% +what the game should look like and also + + + align:start position:0% +what the game should look like and also +partially because we had such an + + align:start position:0% +partially because we had such an + + + align:start position:0% +partially because we had such an +abstract idea of forecast based + + align:start position:0% +abstract idea of forecast based + + + align:start position:0% +abstract idea of forecast based +financing that you know even we didn't + + align:start position:0% +financing that you know even we didn't + + + align:start position:0% +financing that you know even we didn't +have that good of a grass Bond initially + + align:start position:0% +have that good of a grass Bond initially + + + align:start position:0% +have that good of a grass Bond initially +um it took us a while to really get + + align:start position:0% +um it took us a while to really get + + + align:start position:0% +um it took us a while to really get +settled on what we wanted to build and + + align:start position:0% +settled on what we wanted to build and + + + align:start position:0% +settled on what we wanted to build and +so this really challenged our + + align:start position:0% +so this really challenged our + + + align:start position:0% +so this really challenged our +development process and um and made us + + align:start position:0% +development process and um and made us + + + align:start position:0% +development process and um and made us +have to kind of build a lot before we + + align:start position:0% +have to kind of build a lot before we + + + align:start position:0% +have to kind of build a lot before we +got something that we + + align:start position:0% +got something that we + + + align:start position:0% +got something that we +liked and so um eventually we did end up + + align:start position:0% +liked and so um eventually we did end up + + + align:start position:0% +liked and so um eventually we did end up +having to cut some features uh like + + align:start position:0% +having to cut some features uh like + + + align:start position:0% +having to cut some features uh like +multiple levels or like a guided + + align:start position:0% +multiple levels or like a guided + + + align:start position:0% +multiple levels or like a guided +tutorial for the player um we thought + + align:start position:0% +tutorial for the player um we thought + + + align:start position:0% +tutorial for the player um we thought +that this would introduce too much new + + align:start position:0% +that this would introduce too much new + + + align:start position:0% +that this would introduce too much new +content that would need to be play + + align:start position:0% +content that would need to be play + + + align:start position:0% +content that would need to be play +tested balanced and you know um tested + + align:start position:0% +tested balanced and you know um tested + + + align:start position:0% +tested balanced and you know um tested +to ensure consistency with the rest of + + align:start position:0% +to ensure consistency with the rest of + + + align:start position:0% +to ensure consistency with the rest of +our game which we viewed as taking up + + align:start position:0% +our game which we viewed as taking up + + + align:start position:0% +our game which we viewed as taking up +too much time and we also cut the idea + + align:start position:0% +too much time and we also cut the idea + + + align:start position:0% +too much time and we also cut the idea +of adding more individuality to the + + align:start position:0% +of adding more individuality to the + + + align:start position:0% +of adding more individuality to the +indiv uh to the workers or to the toys + + align:start position:0% +indiv uh to the workers or to the toys + + + align:start position:0% +indiv uh to the workers or to the toys +that use saw um other than different + + align:start position:0% +that use saw um other than different + + + align:start position:0% +that use saw um other than different +graphics for + + align:start position:0% +graphics for + + + align:start position:0% +graphics for +each + + align:start position:0% +each + + + align:start position:0% +each +so some of the worst things that we did + + align:start position:0% +so some of the worst things that we did + + + align:start position:0% +so some of the worst things that we did +on our team is that we spent a lot of + + align:start position:0% +on our team is that we spent a lot of + + + align:start position:0% +on our team is that we spent a lot of +time on work that got thrown out + + align:start position:0% +time on work that got thrown out + + + align:start position:0% +time on work that got thrown out +entirely all the prototypes we did they + + align:start position:0% +entirely all the prototypes we did they + + + align:start position:0% +entirely all the prototypes we did they +were actually pretty useful because of + + align:start position:0% +were actually pretty useful because of + + + align:start position:0% +were actually pretty useful because of +the things we learned about the concept + + align:start position:0% +the things we learned about the concept + + + align:start position:0% +the things we learned about the concept +and about how people would play the game + + align:start position:0% +and about how people would play the game + + + align:start position:0% +and about how people would play the game +but we did spend a lot of time on things + + align:start position:0% +but we did spend a lot of time on things + + + align:start position:0% +but we did spend a lot of time on things +like art or you know nitty-gritty + + align:start position:0% +like art or you know nitty-gritty + + + align:start position:0% +like art or you know nitty-gritty +details that didn't really need to be + + align:start position:0% +details that didn't really need to be + + + align:start position:0% +details that didn't really need to be +figured out and that we could have put + + align:start position:0% +figured out and that we could have put + + + align:start position:0% +figured out and that we could have put +off until later in the project + + align:start position:0% +off until later in the project + + + align:start position:0% +off until later in the project +we also kept the game Direction too + + align:start position:0% +we also kept the game Direction too + + + align:start position:0% +we also kept the game Direction too +vague for too long uh as Norman said we + + align:start position:0% +vague for too long uh as Norman said we + + + align:start position:0% +vague for too long uh as Norman said we +spent a lot of time with that and it + + align:start position:0% +spent a lot of time with that and it + + + align:start position:0% +spent a lot of time with that and it +probably ate up too much of our time + + align:start position:0% +probably ate up too much of our time + + + align:start position:0% +probably ate up too much of our time +although it helped us learn we could + + align:start position:0% +although it helped us learn we could + + + align:start position:0% +although it helped us learn we could +have moved faster in the beginning to + + align:start position:0% +have moved faster in the beginning to + + + align:start position:0% +have moved faster in the beginning to +get to a solid idea because once we got + + align:start position:0% +get to a solid idea because once we got + + + align:start position:0% +get to a solid idea because once we got +to a solid idea of the rising Waters our + + align:start position:0% +to a solid idea of the rising Waters our + + + align:start position:0% +to a solid idea of the rising Waters our +team started to centralize around it a + + align:start position:0% +team started to centralize around it a + + + align:start position:0% +team started to centralize around it a +lot better because we could actually + + align:start position:0% +lot better because we could actually + + + align:start position:0% +lot better because we could actually +deal with something concrete while we + + align:start position:0% +deal with something concrete while we + + + align:start position:0% +deal with something concrete while we +were dealing with the abstract ideas + + align:start position:0% +were dealing with the abstract ideas + + + align:start position:0% +were dealing with the abstract ideas +everybody was all over the place and + + align:start position:0% +everybody was all over the place and + + + align:start position:0% +everybody was all over the place and +arguing about things that didn't quite + + align:start position:0% +arguing about things that didn't quite + + + align:start position:0% +arguing about things that didn't quite +line + + align:start position:0% +line + + + align:start position:0% +line +up and the worst decision of all that we + + align:start position:0% +up and the worst decision of all that we + + + align:start position:0% +up and the worst decision of all that we +started with and that sort of made the + + align:start position:0% +started with and that sort of made the + + + align:start position:0% +started with and that sort of made the +problem of going too vague and all these + + align:start position:0% +problem of going too vague and all these + + + align:start position:0% +problem of going too vague and all these +other things happen is that we were + + align:start position:0% +other things happen is that we were + + + align:start position:0% +other things happen is that we were +originally thinking how do we skin + + align:start position:0% +originally thinking how do we skin + + + align:start position:0% +originally thinking how do we skin +forecast based financing as a game how + + align:start position:0% +forecast based financing as a game how + + + align:start position:0% +forecast based financing as a game how +do we take this idea of using forecast + + align:start position:0% +do we take this idea of using forecast + + + align:start position:0% +do we take this idea of using forecast +to make decisions and then just gamify + + align:start position:0% +to make decisions and then just gamify + + + align:start position:0% +to make decisions and then just gamify +it which we eventually realized wasn't + + align:start position:0% +it which we eventually realized wasn't + + + align:start position:0% +it which we eventually realized wasn't +fun and didn't help us actually come up + + align:start position:0% +fun and didn't help us actually come up + + + align:start position:0% +fun and didn't help us actually come up +with any ideas instead when we flipped + + align:start position:0% +with any ideas instead when we flipped + + + align:start position:0% +with any ideas instead when we flipped +it and started talking about what game + + align:start position:0% +it and started talking about what game + + + align:start position:0% +it and started talking about what game +could we create and use forecast based + + align:start position:0% +could we create and use forecast based + + + align:start position:0% +could we create and use forecast based +financing to improve it and teach + + align:start position:0% +financing to improve it and teach + + + align:start position:0% +financing to improve it and teach +something teach players how to play the + + align:start position:0% +something teach players how to play the + + + align:start position:0% +something teach players how to play the +game and therefore allow them to come + + align:start position:0% +game and therefore allow them to come + + + align:start position:0% +game and therefore allow them to come +out of the game Having learned about + + align:start position:0% +out of the game Having learned about + + + align:start position:0% +out of the game Having learned about +forecast based financing the world sort + + align:start position:0% +forecast based financing the world sort + + + align:start position:0% +forecast based financing the world sort +of opened up everything became a lot + + align:start position:0% +of opened up everything became a lot + + + align:start position:0% +of opened up everything became a lot +more interesting and we found that we + + align:start position:0% +more interesting and we found that we + + + align:start position:0% +more interesting and we found that we +started to move + + align:start position:0% +started to move + + + align:start position:0% +started to move +faster some of the best decisions that + + align:start position:0% +faster some of the best decisions that + + + align:start position:0% +faster some of the best decisions that +we made on the other hand as Norman said + + align:start position:0% +we made on the other hand as Norman said + + + align:start position:0% +we made on the other hand as Norman said +we had good tools which meant that even + + align:start position:0% +we had good tools which meant that even + + + align:start position:0% +we had good tools which meant that even +when we threw out prototypes although we + + align:start position:0% +when we threw out prototypes although we + + + align:start position:0% +when we threw out prototypes although we +wasted things like art resources and uh + + align:start position:0% +wasted things like art resources and uh + + + align:start position:0% +wasted things like art resources and uh +things like that we actually didn't end + + align:start position:0% +things like that we actually didn't end + + + align:start position:0% +things like that we actually didn't end +up wasting very much code because things + + align:start position:0% +up wasting very much code because things + + + align:start position:0% +up wasting very much code because things +like the idea of workers or cities could + + align:start position:0% +like the idea of workers or cities could + + + align:start position:0% +like the idea of workers or cities could +literally be pulled out of the old games + + align:start position:0% +literally be pulled out of the old games + + + align:start position:0% +literally be pulled out of the old games +we had put into our new game and then + + align:start position:0% +we had put into our new game and then + + + align:start position:0% +we had put into our new game and then +reworked to build our our new + + align:start position:0% +reworked to build our our new + + + align:start position:0% +reworked to build our our new +structure we also weren't afraid to + + align:start position:0% +structure we also weren't afraid to + + + align:start position:0% +structure we also weren't afraid to +trust each other and throw out the + + align:start position:0% +trust each other and throw out the + + + align:start position:0% +trust each other and throw out the +things that didn't work once we started + + align:start position:0% +things that didn't work once we started + + + align:start position:0% +things that didn't work once we started +moving fast we had a lot of ideas that + + align:start position:0% +moving fast we had a lot of ideas that + + + align:start position:0% +moving fast we had a lot of ideas that +would come out and we'd say okay this + + align:start position:0% +would come out and we'd say okay this + + + align:start position:0% +would come out and we'd say okay this +doesn't work we're actually going to + + align:start position:0% +doesn't work we're actually going to + + + align:start position:0% +doesn't work we're actually going to +scrap it or uh you know we think that + + align:start position:0% +scrap it or uh you know we think that + + + align:start position:0% +scrap it or uh you know we think that +this isn't the direction we need to go + + align:start position:0% +this isn't the direction we need to go + + + align:start position:0% +this isn't the direction we need to go +in and everybody was willing to go along + + align:start position:0% +in and everybody was willing to go along + + + align:start position:0% +in and everybody was willing to go along +with it it's not good to feel it's not a + + align:start position:0% +with it it's not good to feel it's not a + + + align:start position:0% +with it it's not good to feel it's not a +good feeling to see your things thrown + + align:start position:0% +good feeling to see your things thrown + + + align:start position:0% +good feeling to see your things thrown +out but everybody understood that was + + align:start position:0% +out but everybody understood that was + + + align:start position:0% +out but everybody understood that was +for the best of the game and I really + + align:start position:0% +for the best of the game and I really + + + align:start position:0% +for the best of the game and I really +appreciate their understanding with + + align:start position:0% +appreciate their understanding with + + + align:start position:0% +appreciate their understanding with +everything too and part of that all + + align:start position:0% +everything too and part of that all + + + align:start position:0% +everything too and part of that all +comes down to the fact that we were on + + align:start position:0% +comes down to the fact that we were on + + + align:start position:0% +comes down to the fact that we were on +board with our final idea we were all + + align:start position:0% +board with our final idea we were all + + + align:start position:0% +board with our final idea we were all +excited about the concept that we had + + align:start position:0% +excited about the concept that we had + + + align:start position:0% +excited about the concept that we had +part of that might have been the relief + + align:start position:0% +part of that might have been the relief + + + align:start position:0% +part of that might have been the relief +of coming to a concrete idea after + + align:start position:0% +of coming to a concrete idea after + + + align:start position:0% +of coming to a concrete idea after +spending so much time being vague but + + align:start position:0% +spending so much time being vague but + + + align:start position:0% +spending so much time being vague but +once we had that conquered idea we + + align:start position:0% +once we had that conquered idea we + + + align:start position:0% +once we had that conquered idea we +really moved fast and worked well around + + align:start position:0% +really moved fast and worked well around + + + align:start position:0% +really moved fast and worked well around +it + + align:start position:0% +it + + + align:start position:0% +it +so thank you and any + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +questions who did your sound it's + + align:start position:0% +questions who did your sound it's + + + align:start position:0% +questions who did your sound it's +awesome that was from our + + align:start position:0% + + + + align:start position:0% + +you yeah where did you find it um so + + align:start position:0% +you yeah where did you find it um so + + + align:start position:0% +you yeah where did you find it um so +it's on our credits page most of it was + + align:start position:0% +it's on our credits page most of it was + + + align:start position:0% +it's on our credits page most of it was +online uh the credits page in our game + + align:start position:0% + + + + align:start position:0% + +here it's a little small I guess up + + align:start position:0% +here it's a little small I guess up + + + align:start position:0% +here it's a little small I guess up +there but it looks yeah hold my hand AGP + + align:start position:0% +there but it looks yeah hold my hand AGP + + + align:start position:0% +there but it looks yeah hold my hand AGP +by would it be possible be to create + + align:start position:0% +by would it be possible be to create + + + align:start position:0% +by would it be possible be to create +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +shorturl bitly link uh yeah sure we can + + align:start position:0% +shorturl bitly link uh yeah sure we can + + + align:start position:0% +shorturl bitly link uh yeah sure we can +we can make a bitly link and we'll send + + align:start position:0% +we can make a bitly link and we'll send + + + align:start position:0% +we can make a bitly link and we'll send +it out to everyone just + + align:start position:0% +it out to everyone just + + + align:start position:0% +it out to everyone just +yeah that's a good call + + align:start position:0% +yeah that's a good call + + + align:start position:0% +yeah that's a good call +yes having watched the the early crash + + align:start position:0% +yes having watched the the early crash + + + align:start position:0% +yes having watched the the early crash +and burn at the playr um how often do + + align:start position:0% +and burn at the playr um how often do + + + align:start position:0% +and burn at the playr um how often do +people I don't know if you've actually + + align:start position:0% +people I don't know if you've actually + + + align:start position:0% +people I don't know if you've actually +had a lot of people to play your your + + align:start position:0% +had a lot of people to play your your + + + align:start position:0% +had a lot of people to play your your +current version of your game um do + + align:start position:0% +current version of your game um do + + + align:start position:0% +current version of your game um do +people usually take a playthrough or two + + align:start position:0% +people usually take a playthrough or two + + + align:start position:0% +people usually take a playthrough or two +before they start getting the concept + + align:start position:0% +before they start getting the concept + + + align:start position:0% +before they start getting the concept +yes that's why something like a tutorial + + align:start position:0% +yes that's why something like a tutorial + + + align:start position:0% +yes that's why something like a tutorial +would be really nice um unfortunately we + + align:start position:0% +would be really nice um unfortunately we + + + align:start position:0% +would be really nice um unfortunately we +didn't have the time to put it in yeah + + align:start position:0% +didn't have the time to put it in yeah + + + align:start position:0% +didn't have the time to put it in yeah +no + + align:start position:0% +no + + + align:start position:0% +no +no okay yeah usually what happens is + + align:start position:0% +no okay yeah usually what happens is + + + align:start position:0% +no okay yeah usually what happens is +even if after Maybe a couple turns of + + align:start position:0% +even if after Maybe a couple turns of + + + align:start position:0% +even if after Maybe a couple turns of +playing through they start to get the + + align:start position:0% +playing through they start to get the + + + align:start position:0% +playing through they start to get the +idea the problem is that as the water + + align:start position:0% +idea the problem is that as the water + + + align:start position:0% +idea the problem is that as the water +starts to rise they haven't prepared + + align:start position:0% +starts to rise they haven't prepared + + + align:start position:0% +starts to rise they haven't prepared +enough and so all their workers all the + + align:start position:0% +enough and so all their workers all the + + + align:start position:0% +enough and so all their workers all the +toys will starve or get carried away by + + align:start position:0% +toys will starve or get carried away by + + + align:start position:0% +toys will starve or get carried away by +the waves which is a bit unfortunate and + + align:start position:0% +the waves which is a bit unfortunate and + + + align:start position:0% +the waves which is a bit unfortunate and +probably makes the players feel bad on + + align:start position:0% +probably makes the players feel bad on + + + align:start position:0% +probably makes the players feel bad on +the first time but then they it actually + + align:start position:0% +the first time but then they it actually + + + align:start position:0% +the first time but then they it actually +teaches them to think ahead about it so + + align:start position:0% +teaches them to think ahead about it so + + + align:start position:0% +teaches them to think ahead about it so +the next play through they're much more + + align:start position:0% +the next play through they're much more + + + align:start position:0% +the next play through they're much more +careful and + + align:start position:0% + + + + align:start position:0% + +understanding yes um I was wondering if + + align:start position:0% +understanding yes um I was wondering if + + + align:start position:0% +understanding yes um I was wondering if +um you were play any other games or + + align:start position:0% +um you were play any other games or + + + align:start position:0% +um you were play any other games or +thinking about other games as + + align:start position:0% +thinking about other games as + + + align:start position:0% +thinking about other games as +inspiration or thinking about how to + + align:start position:0% +inspiration or thinking about how to + + + align:start position:0% +inspiration or thinking about how to +deal with sort of getting the right + + align:start position:0% +deal with sort of getting the right + + + align:start position:0% +deal with sort of getting the right +level of strategic thinking + + align:start position:0% +level of strategic thinking + + + align:start position:0% +level of strategic thinking +in yeah well so I guess in terms of uh + + align:start position:0% +in yeah well so I guess in terms of uh + + + align:start position:0% +in yeah well so I guess in terms of uh +early on because we had a very different + + align:start position:0% +early on because we had a very different + + + align:start position:0% +early on because we had a very different +idea of uh what we wanted to do early on + + align:start position:0% +idea of uh what we wanted to do early on + + + align:start position:0% +idea of uh what we wanted to do early on +in the process we were thinking about + + align:start position:0% +in the process we were thinking about + + + align:start position:0% +in the process we were thinking about +games like Civilization and how did they + + align:start position:0% +games like Civilization and how did they + + + align:start position:0% +games like Civilization and how did they +communicate all these complex you know + + align:start position:0% +communicate all these complex you know + + + align:start position:0% +communicate all these complex you know +worker movements and managing multiple + + align:start position:0% +worker movements and managing multiple + + + align:start position:0% +worker movements and managing multiple +cities + + align:start position:0% +cities + + + align:start position:0% +cities +but uh once we actually came up with + + align:start position:0% +but uh once we actually came up with + + + align:start position:0% +but uh once we actually came up with +this game concept uh I think we had much + + align:start position:0% +this game concept uh I think we had much + + + align:start position:0% +this game concept uh I think we had much +much smaller goals and so um do we have + + align:start position:0% +much smaller goals and so um do we have + + + align:start position:0% +much smaller goals and so um do we have +any specific game models do you think or + + align:start position:0% +any specific game models do you think or + + + align:start position:0% +any specific game models do you think or +there's none that I specifically think + + align:start position:0% +there's none that I specifically think + + + align:start position:0% +there's none that I specifically think +of there were some things that you know + + align:start position:0% +of there were some things that you know + + + align:start position:0% +of there were some things that you know +we were sort of inspired by standard + + align:start position:0% +we were sort of inspired by standard + + + align:start position:0% +we were sort of inspired by standard +tricks like when you hover over one of + + align:start position:0% +tricks like when you hover over one of + + + align:start position:0% +tricks like when you hover over one of +the characters they got bigger some idea + + align:start position:0% +the characters they got bigger some idea + + + align:start position:0% +the characters they got bigger some idea +of showing off that this is clickable + + align:start position:0% +of showing off that this is clickable + + + align:start position:0% +of showing off that this is clickable +things like that but specific game + + align:start position:0% +things like that but specific game + + + align:start position:0% +things like that but specific game +themselves uh not really I was just + + align:start position:0% +themselves uh not really I was just + + + align:start position:0% +themselves uh not really I was just +thinking it's it ended up being kind of + + align:start position:0% +thinking it's it ended up being kind of + + + align:start position:0% +thinking it's it ended up being kind of +board gamey and I feel like there's a + + align:start position:0% +board gamey and I feel like there's a + + + align:start position:0% +board gamey and I feel like there's a +lot of War games where they've been + + align:start position:0% +lot of War games where they've been + + + align:start position:0% +lot of War games where they've been +thinking a lot about getting that right + + align:start position:0% +thinking a lot about getting that right + + + align:start position:0% +thinking a lot about getting that right +level of uh of I guess tactics rather + + align:start position:0% +level of uh of I guess tactics rather + + + align:start position:0% +level of uh of I guess tactics rather +than strategy but yeah I guess + + align:start position:0% + + + + align:start position:0% + +wor so this you you mentioned that you + + align:start position:0% +wor so this you you mentioned that you + + + align:start position:0% +wor so this you you mentioned that you +were able to completely change how your + + align:start position:0% +were able to completely change how your + + + align:start position:0% +were able to completely change how your +workers looked and just keep your models + + align:start position:0% +workers looked and just keep your models + + + align:start position:0% +workers looked and just keep your models +so that's sort of the Holy Grail of + + align:start position:0% +so that's sort of the Holy Grail of + + + align:start position:0% +so that's sort of the Holy Grail of +object oriented programming that you + + align:start position:0% +object oriented programming that you + + + align:start position:0% +object oriented programming that you +have an object that's reusable and you + + align:start position:0% +have an object that's reusable and you + + + align:start position:0% +have an object that's reusable and you +don't have to throw out the code um do + + align:start position:0% +don't have to throw out the code um do + + + align:start position:0% +don't have to throw out the code um do +you think there's like a reason why in + + align:start position:0% +you think there's like a reason why in + + + align:start position:0% +you think there's like a reason why in +particular you were able to achieve that + + align:start position:0% +particular you were able to achieve that + + + align:start position:0% +particular you were able to achieve that +because I think that's not that's not + + align:start position:0% +because I think that's not that's not + + + align:start position:0% +because I think that's not that's not +common necessarily in object-oriented + + align:start position:0% +common necessarily in object-oriented + + + align:start position:0% +common necessarily in object-oriented +programming + + align:start position:0% +programming + + + align:start position:0% +programming +uh um partially a little bit of OCD like + + align:start position:0% +uh um partially a little bit of OCD like + + + align:start position:0% +uh um partially a little bit of OCD like +very early on very strictly saying um + + align:start position:0% +very early on very strictly saying um + + + align:start position:0% +very early on very strictly saying um +we're going to write this objectoriented + + align:start position:0% +we're going to write this objectoriented + + + align:start position:0% +we're going to write this objectoriented +code and we're not just going to hack + + align:start position:0% +code and we're not just going to hack + + + align:start position:0% +code and we're not just going to hack +things together I think that helped a + + align:start position:0% +things together I think that helped a + + + align:start position:0% +things together I think that helped a +lot because um we actually spended time + + align:start position:0% +lot because um we actually spended time + + + align:start position:0% +lot because um we actually spended time +in the very beginning to think about + + align:start position:0% +in the very beginning to think about + + + align:start position:0% +in the very beginning to think about +like which which objects were + + align:start position:0% +like which which objects were + + + align:start position:0% +like which which objects were +responsible for what and what their + + align:start position:0% +responsible for what and what their + + + align:start position:0% +responsible for what and what their +purpose should be so yeah basically I + + align:start position:0% +purpose should be so yeah basically I + + + align:start position:0% +purpose should be so yeah basically I +think because we moved more slowly in + + align:start position:0% +think because we moved more slowly in + + + align:start position:0% +think because we moved more slowly in +the start and thought more carefully + + align:start position:0% +the start and thought more carefully + + + align:start position:0% +the start and thought more carefully +about how that code should be structured + + align:start position:0% +about how that code should be structured + + + align:start position:0% +about how that code should be structured +we ended up with having an easier time + + align:start position:0% +we ended up with having an easier time + + + align:start position:0% +we ended up with having an easier time +later on there's also the fact that + + align:start position:0% +later on there's also the fact that + + + align:start position:0% +later on there's also the fact that +because we had learned these things from + + align:start position:0% +because we had learned these things from + + + align:start position:0% +because we had learned these things from +the Prototype that we were putting into + + align:start position:0% +the Prototype that we were putting into + + + align:start position:0% +the Prototype that we were putting into +this game that also meant that + + align:start position:0% +this game that also meant that + + + align:start position:0% +this game that also meant that +the the objects that we + + align:start position:0% +the the objects that we + + + align:start position:0% +the the objects that we +created because we wanted similar + + align:start position:0% +created because we wanted similar + + + align:start position:0% +created because we wanted similar +functionality to things that we had + + align:start position:0% +functionality to things that we had + + + align:start position:0% +functionality to things that we had +already seen and we knew worked it meant + + align:start position:0% +already seen and we knew worked it meant + + + align:start position:0% +already seen and we knew worked it meant +that we were comfortable pulling out the + + align:start position:0% +that we were comfortable pulling out the + + + align:start position:0% +that we were comfortable pulling out the +functionality into that uh so I won't I + + align:start position:0% +functionality into that uh so I won't I + + + align:start position:0% +functionality into that uh so I won't I +don't want to say it was designed to fit + + align:start position:0% +don't want to say it was designed to fit + + + align:start position:0% +don't want to say it was designed to fit +but there is some there is the fact that + + align:start position:0% +but there is some there is the fact that + + + align:start position:0% +but there is some there is the fact that +we moved it on purpose + + align:start position:0% +we moved it on purpose + + + align:start position:0% +we moved it on purpose +really I something so uh we had a very + + align:start position:0% +really I something so uh we had a very + + + align:start position:0% +really I something so uh we had a very +good NBC model uh so models were + + align:start position:0% +good NBC model uh so models were + + + align:start position:0% +good NBC model uh so models were +three like structure and it was very + + align:start position:0% +three like structure and it was very + + + align:start position:0% +three like structure and it was very +easy to change models so models knew + + align:start position:0% +easy to change models so models knew + + + align:start position:0% +easy to change models so models knew +about uh sorry use knew about models but + + align:start position:0% +about uh sorry use knew about models but + + + align:start position:0% +about uh sorry use knew about models but +models and no idea about use so + + align:start position:0% +models and no idea about use so + + + align:start position:0% +models and no idea about use so +basically + + align:start position:0% + + + + align:start position:0% + +[Applause] \ No newline at end of file diff --git a/muLn57VrGAA.txt b/muLn57VrGAA.txt new file mode 100644 index 0000000000000000000000000000000000000000..712643765c3cf89f27256e42fc8af941e4c6f46c --- /dev/null +++ b/muLn57VrGAA.txt @@ -0,0 +1,907 @@ +align:start position:0% + +in the last lecture we introduced the + + align:start position:0% +in the last lecture we introduced the + + + align:start position:0% +in the last lecture we introduced the +notion of virtual memory and added a + + align:start position:0% +notion of virtual memory and added a + + + align:start position:0% +notion of virtual memory and added a +memory management unit MMU to translate + + align:start position:0% +memory management unit MMU to translate + + + align:start position:0% +memory management unit MMU to translate +the virtual addresses generated by the + + align:start position:0% +the virtual addresses generated by the + + + align:start position:0% +the virtual addresses generated by the +CPU to the physical address is sent to + + align:start position:0% +CPU to the physical address is sent to + + + align:start position:0% +CPU to the physical address is sent to +main memory this gave us the ability to + + align:start position:0% +main memory this gave us the ability to + + + align:start position:0% +main memory this gave us the ability to +share physical memory between many + + align:start position:0% +share physical memory between many + + + align:start position:0% +share physical memory between many +running programs while still giving each + + align:start position:0% +running programs while still giving each + + + align:start position:0% +running programs while still giving each +program the illusion of having its own + + align:start position:0% +program the illusion of having its own + + + align:start position:0% +program the illusion of having its own +large address space both the virtual and + + align:start position:0% +large address space both the virtual and + + + align:start position:0% +large address space both the virtual and +physical address spaces are divided into + + align:start position:0% +physical address spaces are divided into + + + align:start position:0% +physical address spaces are divided into +a sequence of pages each holding some + + align:start position:0% +a sequence of pages each holding some + + + align:start position:0% +a sequence of pages each holding some +fixed number of locations for example if + + align:start position:0% +fixed number of locations for example if + + + align:start position:0% +fixed number of locations for example if +each page holds 2 to the 12th bytes a + + align:start position:0% +each page holds 2 to the 12th bytes a + + + align:start position:0% +each page holds 2 to the 12th bytes a +32-bit address would have 2 to the 32 + + align:start position:0% +32-bit address would have 2 to the 32 + + + align:start position:0% +32-bit address would have 2 to the 32 +divided by 2 to the 12th or 2 to the + + align:start position:0% +divided by 2 to the 12th or 2 to the + + + align:start position:0% +divided by 2 to the 12th or 2 to the +20th pages in this example the 32-bit + + align:start position:0% +20th pages in this example the 32-bit + + + align:start position:0% +20th pages in this example the 32-bit +address can be thought of as having 2 + + align:start position:0% +address can be thought of as having 2 + + + align:start position:0% +address can be thought of as having 2 +fields a 20-bit page number form from + + align:start position:0% +fields a 20-bit page number form from + + + align:start position:0% +fields a 20-bit page number form from +the higher-order address bits and a 12 + + align:start position:0% +the higher-order address bits and a 12 + + + align:start position:0% +the higher-order address bits and a 12 +bit page offset form from the low order + + align:start position:0% +bit page offset form from the low order + + + align:start position:0% +bit page offset form from the low order +address bits this arrangement + + align:start position:0% +address bits this arrangement + + + align:start position:0% +address bits this arrangement +ensures that nearby data will be located + + align:start position:0% +ensures that nearby data will be located + + + align:start position:0% +ensures that nearby data will be located +on the same page the MMU translates + + align:start position:0% +on the same page the MMU translates + + + align:start position:0% +on the same page the MMU translates +virtual page numbers into physical page + + align:start position:0% +virtual page numbers into physical page + + + align:start position:0% +virtual page numbers into physical page +numbers using a page map conceptually + + align:start position:0% +numbers using a page map conceptually + + + align:start position:0% +numbers using a page map conceptually +the page map is an array where each + + align:start position:0% +the page map is an array where each + + + align:start position:0% +the page map is an array where each +entry in the array contains a physical + + align:start position:0% +entry in the array contains a physical + + + align:start position:0% +entry in the array contains a physical +page number along with a couple of bits + + align:start position:0% +page number along with a couple of bits + + + align:start position:0% +page number along with a couple of bits +indicating the page status the + + align:start position:0% +indicating the page status the + + + align:start position:0% +indicating the page status the +translation process is simple the + + align:start position:0% +translation process is simple the + + + align:start position:0% +translation process is simple the +virtual page number is used as an index + + align:start position:0% +virtual page number is used as an index + + + align:start position:0% +virtual page number is used as an index +into the array to fetch the + + align:start position:0% +into the array to fetch the + + + align:start position:0% +into the array to fetch the +corresponding physical page number the + + align:start position:0% +corresponding physical page number the + + + align:start position:0% +corresponding physical page number the +physical page number is then combined + + align:start position:0% +physical page number is then combined + + + align:start position:0% +physical page number is then combined +with the page offset to form the + + align:start position:0% +with the page offset to form the + + + align:start position:0% +with the page offset to form the +complete physical address in the actual + + align:start position:0% +complete physical address in the actual + + + align:start position:0% +complete physical address in the actual +implementation the page map is usually + + align:start position:0% +implementation the page map is usually + + + align:start position:0% +implementation the page map is usually +organized into multiple levels which + + align:start position:0% +organized into multiple levels which + + + align:start position:0% +organized into multiple levels which +permits us to have resident only the + + align:start position:0% +permits us to have resident only the + + + align:start position:0% +permits us to have resident only the +portion of the page map we're actively + + align:start position:0% +portion of the page map we're actively + + + align:start position:0% +portion of the page map we're actively +using and to avoid the cost of accessing + + align:start position:0% +using and to avoid the cost of accessing + + + align:start position:0% +using and to avoid the cost of accessing +the page map on each address translation + + align:start position:0% +the page map on each address translation + + + align:start position:0% +the page map on each address translation +we use a cache called the translation + + align:start position:0% +we use a cache called the translation + + + align:start position:0% +we use a cache called the translation +lookaside buffer to remember the results + + align:start position:0% +lookaside buffer to remember the results + + + align:start position:0% +lookaside buffer to remember the results +of recent VPN to PPN translations all + + align:start position:0% +of recent VPN to PPN translations all + + + align:start position:0% +of recent VPN to PPN translations all +allocated locations of each virtual + + align:start position:0% +allocated locations of each virtual + + + align:start position:0% +allocated locations of each virtual +address space can be found on secondary + + align:start position:0% +address space can be found on secondary + + + align:start position:0% +address space can be found on secondary +storage note that they may not + + align:start position:0% +storage note that they may not + + + align:start position:0% +storage note that they may not +necessarily be resident in main + + align:start position:0% +necessarily be resident in main + + + align:start position:0% +necessarily be resident in main +Marie if the CPU attempts to access a + + align:start position:0% +Marie if the CPU attempts to access a + + + align:start position:0% +Marie if the CPU attempts to access a +virtual address that's not resident in + + align:start position:0% +virtual address that's not resident in + + + align:start position:0% +virtual address that's not resident in +main memory a page fault is signaled and + + align:start position:0% +main memory a page fault is signaled and + + + align:start position:0% +main memory a page fault is signaled and +the operating system will arrange to + + align:start position:0% +the operating system will arrange to + + + align:start position:0% +the operating system will arrange to +move the desired page from secondary + + align:start position:0% +move the desired page from secondary + + + align:start position:0% +move the desired page from secondary +storage into main memory in practice + + align:start position:0% +storage into main memory in practice + + + align:start position:0% +storage into main memory in practice +only the active pages for each program + + align:start position:0% +only the active pages for each program + + + align:start position:0% +only the active pages for each program +are resident in main memory at any given + + align:start position:0% +are resident in main memory at any given + + + align:start position:0% +are resident in main memory at any given +time here's a diagram showing the + + align:start position:0% +time here's a diagram showing the + + + align:start position:0% +time here's a diagram showing the +translation process first we check to + + align:start position:0% +translation process first we check to + + + align:start position:0% +translation process first we check to +see if the required VPN to PPN mapping + + align:start position:0% +see if the required VPN to PPN mapping + + + align:start position:0% +see if the required VPN to PPN mapping +is cached in the TLB if not we have to + + align:start position:0% +is cached in the TLB if not we have to + + + align:start position:0% +is cached in the TLB if not we have to +access the hierarchical page map to see + + align:start position:0% +access the hierarchical page map to see + + + align:start position:0% +access the hierarchical page map to see +if the page is resident and if so look + + align:start position:0% +if the page is resident and if so look + + + align:start position:0% +if the page is resident and if so look +up its physical page number if we + + align:start position:0% +up its physical page number if we + + + align:start position:0% +up its physical page number if we +discover that the page is not resident a + + align:start position:0% +discover that the page is not resident a + + + align:start position:0% +discover that the page is not resident a +page fault exception is signaled to the + + align:start position:0% +page fault exception is signaled to the + + + align:start position:0% +page fault exception is signaled to the +CPU so that it can run a handler to load + + align:start position:0% +CPU so that it can run a handler to load + + + align:start position:0% +CPU so that it can run a handler to load +the page from secondary storage note + + align:start position:0% +the page from secondary storage note + + + align:start position:0% +the page from secondary storage note +that access to a particular mapping + + align:start position:0% +that access to a particular mapping + + + align:start position:0% +that access to a particular mapping +context is controlled by two registers + + align:start position:0% +context is controlled by two registers + + + align:start position:0% +context is controlled by two registers +the context number register controls + + align:start position:0% +the context number register controls + + + align:start position:0% +the context number register controls +which mappings are accessible in the TLB + + align:start position:0% +which mappings are accessible in the TLB + + + align:start position:0% +which mappings are accessible in the TLB +and the page directory register + + align:start position:0% +and the page directory register + + + align:start position:0% +and the page directory register +indicates which physical page holds the + + align:start position:0% +indicates which physical page holds the + + + align:start position:0% +indicates which physical page holds the +top tier of the hierarchical page map we + + align:start position:0% +top tier of the hierarchical page map we + + + align:start position:0% +top tier of the hierarchical page map we +can switch to another context by simply + + align:start position:0% +can switch to another context by simply + + + align:start position:0% +can switch to another context by simply +reloading these two registers to + + align:start position:0% +reloading these two registers to + + + align:start position:0% +reloading these two registers to +effectively accommodate multiple + + align:start position:0% +effectively accommodate multiple + + + align:start position:0% +effectively accommodate multiple +contacts we'll need to have sufficient + + align:start position:0% +contacts we'll need to have sufficient + + + align:start position:0% +contacts we'll need to have sufficient +TLB capacity to simultaneously cache the + + align:start position:0% +TLB capacity to simultaneously cache the + + + align:start position:0% +TLB capacity to simultaneously cache the +most frequent mappings for all the + + align:start position:0% +most frequent mappings for all the + + + align:start position:0% +most frequent mappings for all the +processes and we'll need some number of + + align:start position:0% +processes and we'll need some number of + + + align:start position:0% +processes and we'll need some number of +physical pages to hold the required page + + align:start position:0% +physical pages to hold the required page + + + align:start position:0% +physical pages to hold the required page +directories and segments of the page + + align:start position:0% +directories and segments of the page + + + align:start position:0% +directories and segments of the page +tables for example for a particular + + align:start position:0% +tables for example for a particular + + + align:start position:0% +tables for example for a particular +process three pages will suffice to hold + + align:start position:0% +process three pages will suffice to hold + + + align:start position:0% +process three pages will suffice to hold +the resident two-level page map for 1024 + + align:start position:0% +the resident two-level page map for 1024 + + + align:start position:0% +the resident two-level page map for 1024 +pages at each end of the virtual address + + align:start position:0% +pages at each end of the virtual address + + + align:start position:0% +pages at each end of the virtual address +space providing access to up to eight + + align:start position:0% +space providing access to up to eight + + + align:start position:0% +space providing access to up to eight +megabytes of code stack and heap more + + align:start position:0% +megabytes of code stack and heap more + + + align:start position:0% +megabytes of code stack and heap more +than enough for many simple programs the + + align:start position:0% +than enough for many simple programs the + + + align:start position:0% +than enough for many simple programs the +page map creates the context needed to + + align:start position:0% +page map creates the context needed to + + + align:start position:0% +page map creates the context needed to +translate virtual addresses to physical + + align:start position:0% +translate virtual addresses to physical + + + align:start position:0% +translate virtual addresses to physical +addresses in a computer system that's + + align:start position:0% +addresses in a computer system that's + + + align:start position:0% +addresses in a computer system that's +working on multiple tasks at the same + + align:start position:0% +working on multiple tasks at the same + + + align:start position:0% +working on multiple tasks at the same +time we would like to support multiple + + align:start position:0% +time we would like to support multiple + + + align:start position:0% +time we would like to support multiple +contexts and to be able to quickly + + align:start position:0% +contexts and to be able to quickly + + + align:start position:0% +contexts and to be able to quickly +switch from one context to another + + align:start position:0% +switch from one context to another + + + align:start position:0% +switch from one context to another +multiple contexts would allow us to + + align:start position:0% +multiple contexts would allow us to + + + align:start position:0% +multiple contexts would allow us to +share physical memory between multiple + + align:start position:0% +share physical memory between multiple + + + align:start position:0% +share physical memory between multiple +programs + + align:start position:0% +programs + + + align:start position:0% +programs +each program would have an independent + + align:start position:0% +each program would have an independent + + + align:start position:0% +each program would have an independent +virtual address space for example two + + align:start position:0% +virtual address space for example two + + + align:start position:0% +virtual address space for example two +programs could both access virtual zero + + align:start position:0% +programs could both access virtual zero + + + align:start position:0% +programs could both access virtual zero +as the address of the first instruction + + align:start position:0% +as the address of the first instruction + + + align:start position:0% +as the address of the first instruction +and would end up accessing different + + align:start position:0% +and would end up accessing different + + + align:start position:0% +and would end up accessing different +physical locations in main memory when + + align:start position:0% +physical locations in main memory when + + + align:start position:0% +physical locations in main memory when +switching between programs we perform a + + align:start position:0% +switching between programs we perform a + + + align:start position:0% +switching between programs we perform a +context switch to move to the + + align:start position:0% +context switch to move to the + + + align:start position:0% +context switch to move to the +appropriate MMU context the ability to + + align:start position:0% +appropriate MMU context the ability to + + + align:start position:0% +appropriate MMU context the ability to +share the CPU between many programs + + align:start position:0% +share the CPU between many programs + + + align:start position:0% +share the CPU between many programs +seems like a great idea let's figure out + + align:start position:0% +seems like a great idea let's figure out + + + align:start position:0% +seems like a great idea let's figure out +the details of how that might work \ No newline at end of file diff --git a/n1cXiw3s72k.txt b/n1cXiw3s72k.txt new file mode 100644 index 0000000000000000000000000000000000000000..f55df9b005130826f91017f5025094d1a6245a73 --- /dev/null +++ b/n1cXiw3s72k.txt @@ -0,0 +1,475 @@ +align:start position:0% + +up until now we have analyzed the motion + + align:start position:0% +up until now we have analyzed the motion + + + align:start position:0% +up until now we have analyzed the motion +of objects that we treated as so-called + + align:start position:0% +of objects that we treated as so-called + + + align:start position:0% +of objects that we treated as so-called +point masses we're literally all of the + + align:start position:0% +point masses we're literally all of the + + + align:start position:0% +point masses we're literally all of the +mass of the object was treated as lying + + align:start position:0% +mass of the object was treated as lying + + + align:start position:0% +mass of the object was treated as lying +at a single point this is obviously an + + align:start position:0% +at a single point this is obviously an + + + align:start position:0% +at a single point this is obviously an +unrealistic idealization real objects + + align:start position:0% +unrealistic idealization real objects + + + align:start position:0% +unrealistic idealization real objects +have spatial extent and come in various + + align:start position:0% +have spatial extent and come in various + + + align:start position:0% +have spatial extent and come in various +sizes and shapes some regular and some + + align:start position:0% +sizes and shapes some regular and some + + + align:start position:0% +sizes and shapes some regular and some +highly irregular the mass distribution + + align:start position:0% +highly irregular the mass distribution + + + align:start position:0% +highly irregular the mass distribution +within these extended objects might be + + align:start position:0% +within these extended objects might be + + + align:start position:0% +within these extended objects might be +smooth and uniform or highly non-uniform + + align:start position:0% +smooth and uniform or highly non-uniform + + + align:start position:0% +smooth and uniform or highly non-uniform +and lumpy moreover sometimes we will be + + align:start position:0% +and lumpy moreover sometimes we will be + + + align:start position:0% +and lumpy moreover sometimes we will be +interested in simultaneously analyzing a + + align:start position:0% +interested in simultaneously analyzing a + + + align:start position:0% +interested in simultaneously analyzing a +large system of particles or objects to + + align:start position:0% +large system of particles or objects to + + + align:start position:0% +large system of particles or objects to +deal properly with such situations it is + + align:start position:0% +deal properly with such situations it is + + + align:start position:0% +deal properly with such situations it is +necessary to introduce a new physical + + align:start position:0% +necessary to introduce a new physical + + + align:start position:0% +necessary to introduce a new physical +quantity called the momentum which is a + + align:start position:0% +quantity called the momentum which is a + + + align:start position:0% +quantity called the momentum which is a +vector that we traditionally denote with + + align:start position:0% +vector that we traditionally denote with + + + align:start position:0% +vector that we traditionally denote with +the symbol P for a single point mass the + + align:start position:0% +the symbol P for a single point mass the + + + align:start position:0% +the symbol P for a single point mass the +momentum is a product of the mass and + + align:start position:0% +momentum is a product of the mass and + + + align:start position:0% +momentum is a product of the mass and +the velocity vector the form of Newton's + + align:start position:0% +the velocity vector the form of Newton's + + + align:start position:0% +the velocity vector the form of Newton's +second law that we have used so far F + + align:start position:0% +second law that we have used so far F + + + align:start position:0% +second law that we have used so far F +equals MA is actually only true for the + + align:start position:0% +equals MA is actually only true for the + + + align:start position:0% +equals MA is actually only true for the +special case of a point mass the more + + align:start position:0% +special case of a point mass the more + + + align:start position:0% +special case of a point mass the more +general form of Newton's second law is + + align:start position:0% +general form of Newton's second law is + + + align:start position:0% +general form of Newton's second law is +that F equals DP DT that is that the + + align:start position:0% +that F equals DP DT that is that the + + + align:start position:0% +that F equals DP DT that is that the +force is equal to the time derivative of + + align:start position:0% +force is equal to the time derivative of + + + align:start position:0% +force is equal to the time derivative of +the momentum vector this is applicable + + align:start position:0% +the momentum vector this is applicable + + + align:start position:0% +the momentum vector this is applicable +to either a single particle or to a + + align:start position:0% +to either a single particle or to a + + + align:start position:0% +to either a single particle or to a +system of particles this more general + + align:start position:0% +system of particles this more general + + + align:start position:0% +system of particles this more general +form provides us a way to address + + align:start position:0% +form provides us a way to address + + + align:start position:0% +form provides us a way to address +extended objects or multi particle + + align:start position:0% +extended objects or multi particle + + + align:start position:0% +extended objects or multi particle +systems we will once again appeal to a + + align:start position:0% +systems we will once again appeal to a + + + align:start position:0% +systems we will once again appeal to a +calculus like argument breaking down an + + align:start position:0% +calculus like argument breaking down an + + + align:start position:0% +calculus like argument breaking down an +extended distribution into a large + + align:start position:0% +extended distribution into a large + + + align:start position:0% +extended distribution into a large +number of small elements treating each + + align:start position:0% +number of small elements treating each + + + align:start position:0% +number of small elements treating each +element separately and then summing the + + align:start position:0% +element separately and then summing the + + + align:start position:0% +element separately and then summing the +results as part of this process we will + + align:start position:0% +results as part of this process we will + + + align:start position:0% +results as part of this process we will +introduce the concept of the center of + + align:start position:0% +introduce the concept of the center of + + + align:start position:0% +introduce the concept of the center of +mass a sort of mass weighted average + + align:start position:0% +mass a sort of mass weighted average + + + align:start position:0% +mass a sort of mass weighted average +position for an extended object or + + align:start position:0% +position for an extended object or + + + align:start position:0% +position for an extended object or +system momentum is also the first of + + align:start position:0% +system momentum is also the first of + + + align:start position:0% +system momentum is also the first of +several special measurable quantities + + align:start position:0% +several special measurable quantities + + + align:start position:0% +several special measurable quantities +that we will discuss that obey special + + align:start position:0% +that we will discuss that obey special + + + align:start position:0% +that we will discuss that obey special +powerful rules called conservation laws + + align:start position:0% +powerful rules called conservation laws + + + align:start position:0% +powerful rules called conservation laws +the other two quantities are energy and + + align:start position:0% +the other two quantities are energy and + + + align:start position:0% +the other two quantities are energy and +angular momentum conservation laws are + + align:start position:0% +angular momentum conservation laws are + + + align:start position:0% +angular momentum conservation laws are +principles that provide that the given + + align:start position:0% +principles that provide that the given + + + align:start position:0% +principles that provide that the given +measurable quantity remains unchanged + + align:start position:0% +measurable quantity remains unchanged + + + align:start position:0% +measurable quantity remains unchanged +during the evolution of a system with + + align:start position:0% +during the evolution of a system with + + + align:start position:0% +during the evolution of a system with +time as long as certain requirements are + + align:start position:0% +time as long as certain requirements are + + + align:start position:0% +time as long as certain requirements are +met essentially the requirement that a + + align:start position:0% +met essentially the requirement that a + + + align:start position:0% +met essentially the requirement that a +system remains isolated with this + + align:start position:0% +system remains isolated with this + + + align:start position:0% +system remains isolated with this +restriction in place the possible + + align:start position:0% +restriction in place the possible + + + align:start position:0% +restriction in place the possible +evolution of motion of a particle + + align:start position:0% +evolution of motion of a particle + + + align:start position:0% +evolution of motion of a particle +or system of particles is greatly + + align:start position:0% +or system of particles is greatly + + + align:start position:0% +or system of particles is greatly +restricted simplifying this calculation + + align:start position:0% +restricted simplifying this calculation + + + align:start position:0% +restricted simplifying this calculation +we will see how this can be used to our + + align:start position:0% +we will see how this can be used to our + + + align:start position:0% +we will see how this can be used to our +advantage in understanding what will + + align:start position:0% +advantage in understanding what will + + + align:start position:0% +advantage in understanding what will +happen \ No newline at end of file diff --git a/nmuXpvSIm3k.txt b/nmuXpvSIm3k.txt new file mode 100644 index 0000000000000000000000000000000000000000..860497c3bbfe9d60b867954beeab3f5f710ff5d0 --- /dev/null +++ b/nmuXpvSIm3k.txt @@ -0,0 +1,14651 @@ +align:start position:0% + +it's our last class which is happy + + align:start position:0% +it's our last class which is happy + + + align:start position:0% +it's our last class which is happy +because we get to go on break but + + align:start position:0% +because we get to go on break but + + + align:start position:0% +because we get to go on break but +there's so much more I want to tell you + + align:start position:0% +there's so much more I want to tell you + + + align:start position:0% +there's so much more I want to tell you +guys so but you know that's all we have + + align:start position:0% +guys so but you know that's all we have + + + align:start position:0% +guys so but you know that's all we have +time for uh there are cookies here for + + align:start position:0% +time for uh there are cookies here for + + + align:start position:0% +time for uh there are cookies here for +to make our last class sweet so please + + align:start position:0% +to make our last class sweet so please + + + align:start position:0% +to make our last class sweet so please +come and get some if you want they're + + align:start position:0% +come and get some if you want they're + + + align:start position:0% +come and get some if you want they're +very small so you can take to uh or you + + align:start position:0% +very small so you can take to uh or you + + + align:start position:0% +very small so you can take to uh or you +know if you didn't want to commit a + + align:start position:0% +know if you didn't want to commit a + + + align:start position:0% +know if you didn't want to commit a +large cookie you don't need + + align:start position:0% +large cookie you don't need + + + align:start position:0% +large cookie you don't need +to so uh okay so today uh finally we're + + align:start position:0% +to so uh okay so today uh finally we're + + + align:start position:0% +to so uh okay so today uh finally we're +going to actually construct the snars + + align:start position:0% +going to actually construct the snars + + + align:start position:0% +going to actually construct the snars +that we've been after that was kind of + + align:start position:0% +that we've been after that was kind of + + + align:start position:0% +that we've been after that was kind of +the goal uh is to uh construct uh snars + + align:start position:0% +the goal uh is to uh construct uh snars + + + align:start position:0% +the goal uh is to uh construct uh snars +s interactive arguments and like this + + align:start position:0% +s interactive arguments and like this + + + align:start position:0% +s interactive arguments and like this +entire course was a buildup to construct + + align:start position:0% +entire course was a buildup to construct + + + align:start position:0% +entire course was a buildup to construct +uh these snars and today we're going to + + align:start position:0% +uh these snars and today we're going to + + + align:start position:0% +uh these snars and today we're going to +see how to construct them uh they + + align:start position:0% +see how to construct them uh they + + + align:start position:0% +see how to construct them uh they +cookies + + align:start position:0% +cookies + + + align:start position:0% +cookies +guys cookies if you want from flower + + align:start position:0% +guys cookies if you want from flower + + + align:start position:0% +guys cookies if you want from flower +really good ones so feel free to take + + align:start position:0% +really good ones so feel free to take + + + align:start position:0% +really good ones so feel free to take +some um okay so uh what we're going to + + align:start position:0% +some um okay so uh what we're going to + + + align:start position:0% +some um okay so uh what we're going to +do today is show how to construct these + + align:start position:0% +do today is show how to construct these + + + align:start position:0% +do today is show how to construct these +snarks uh and uh we're gonna last class + + align:start position:0% +snarks uh and uh we're gonna last class + + + align:start position:0% +snarks uh and uh we're gonna last class +Jen Jang uh uh showed you is a really + + align:start position:0% +Jen Jang uh uh showed you is a really + + + align:start position:0% +Jen Jang uh uh showed you is a really +beautiful work on constructing bargs + + align:start position:0% +beautiful work on constructing bargs + + + align:start position:0% +beautiful work on constructing bargs +which are batch + + align:start position:0% +which are batch + + + align:start position:0% +which are batch +argument and you know on their own you + + align:start position:0% +argument and you know on their own you + + + align:start position:0% +argument and you know on their own you +can say uh why do we care about B + + align:start position:0% +can say uh why do we care about B + + + align:start position:0% +can say uh why do we care about B +argument I'm going to recall the + + align:start position:0% +argument I'm going to recall the + + + align:start position:0% +argument I'm going to recall the +definition but the I mean it's + + align:start position:0% +definition but the I mean it's + + + align:start position:0% +definition but the I mean it's +interesting on its own but what makes it + + align:start position:0% +interesting on its own but what makes it + + + align:start position:0% +interesting on its own but what makes it +super interesting is that we can use it + + align:start position:0% +super interesting is that we can use it + + + align:start position:0% +super interesting is that we can use it +in a pretty straightforward manner to + + align:start position:0% +in a pretty straightforward manner to + + + align:start position:0% +in a pretty straightforward manner to +construct snars so that's what we're + + align:start position:0% +construct snars so that's what we're + + + align:start position:0% +construct snars so that's what we're +going to see today we're going to see + + align:start position:0% +going to see today we're going to see + + + align:start position:0% +going to see today we're going to see +how to use these bars that I'm going to + + align:start position:0% +how to use these bars that I'm going to + + + align:start position:0% +how to use these bars that I'm going to +recall the definition in a second and + + align:start position:0% +recall the definition in a second and + + + align:start position:0% +recall the definition in a second and +also how to use I think Jen Jong called + + align:start position:0% +also how to use I think Jen Jong called + + + align:start position:0% +also how to use I think Jen Jong called +it a somewhere statistically binding + + align:start position:0% +it a somewhere statistically binding + + + align:start position:0% +it a somewhere statistically binding +hash functions it's also known in the + + align:start position:0% +hash functions it's also known in the + + + align:start position:0% +hash functions it's also known in the +literature as somewh extractable hash + + align:start position:0% +literature as somewh extractable hash + + + align:start position:0% +literature as somewh extractable hash +functions both are used so I'm just + + align:start position:0% +functions both are used so I'm just + + + align:start position:0% +functions both are used so I'm just +going to use the other just so familiar + + align:start position:0% +going to use the other just so familiar + + + align:start position:0% +going to use the other just so familiar +with both uh a uh formulations uh both + + align:start position:0% +with both uh a uh formulations uh both + + + align:start position:0% +with both uh a uh formulations uh both +names uh so what we're going to see + + align:start position:0% +names uh so what we're going to see + + + align:start position:0% +names uh so what we're going to see +today is how to use these bars with with + + align:start position:0% +today is how to use these bars with with + + + align:start position:0% +today is how to use these bars with with +these hash functions to get + + align:start position:0% +these hash functions to get + + + align:start position:0% +these hash functions to get +snars that's kind of uh the plan for + + align:start position:0% +snars that's kind of uh the plan for + + + align:start position:0% +snars that's kind of uh the plan for +today uh so let me first recall what a + + align:start position:0% +today uh so let me first recall what a + + + align:start position:0% +today uh so let me first recall what a +barg is really uh fast so a bar you want + + align:start position:0% +barg is really uh fast so a bar you want + + + align:start position:0% +barg is really uh fast so a bar you want +to kind of prove that many instances + + align:start position:0% +to kind of prove that many instances + + + align:start position:0% +to kind of prove that many instances +belong to an NP language so about Mark + + align:start position:0% +belong to an NP language so about Mark + + + align:start position:0% +belong to an NP language so about Mark +for an NP language L consists of three + + align:start position:0% +for an NP language L consists of three + + + align:start position:0% +for an NP language L consists of three +algorithm gen uh takes as input a + + align:start position:0% +algorithm gen uh takes as input a + + + align:start position:0% +algorithm gen uh takes as input a +security parameter the number of + + align:start position:0% +security parameter the number of + + + align:start position:0% +security parameter the number of +instances you want to batch maybe I'll + + align:start position:0% +instances you want to batch maybe I'll + + + align:start position:0% +instances you want to batch maybe I'll +close thank you can you close the door + + align:start position:0% +close thank you can you close the door + + + align:start position:0% +close thank you can you close the door +thanks uh K which is the number of + + align:start position:0% +thanks uh K which is the number of + + + align:start position:0% +thanks uh K which is the number of +instances you want to batch and N with + + align:start position:0% +instances you want to batch and N with + + + align:start position:0% +instances you want to batch and N with +which is the length of each instance and + + align:start position:0% +which is the length of each instance and + + + align:start position:0% +which is the length of each instance and +then + + align:start position:0% +then + + + align:start position:0% +then +output uh some + + align:start position:0% + + + + align:start position:0% + +CRS note Lambda is given in unary + + align:start position:0% +CRS note Lambda is given in unary + + + align:start position:0% +CRS note Lambda is given in unary +because we want them to run in time poly + + align:start position:0% +because we want them to run in time poly + + + align:start position:0% +because we want them to run in time poly +Lambda but K and N are given in binary + + align:start position:0% +Lambda but K and N are given in binary + + + align:start position:0% +Lambda but K and N are given in binary +so because it's polinomial time + + align:start position:0% +so because it's polinomial time + + + align:start position:0% +so because it's polinomial time +algorithm it runs in time poog in K poog + + align:start position:0% +algorithm it runs in time poog in K poog + + + align:start position:0% +algorithm it runs in time poog in K poog +in N the instant size okay and then the + + align:start position:0% +in N the instant size okay and then the + + + align:start position:0% +in N the instant size okay and then the +Prov algorithm takes as input uh the + + align:start position:0% +Prov algorithm takes as input uh the + + + align:start position:0% +Prov algorithm takes as input uh the +CRS and then X1 up to xn uh XK sorry so + + align:start position:0% +CRS and then X1 up to xn uh XK sorry so + + + align:start position:0% +CRS and then X1 up to xn uh XK sorry so +K elements with + + align:start position:0% +K elements with + + + align:start position:0% +K elements with +Witnesses and outputs + + align:start position:0% + + + + align:start position:0% + +uh proof + + align:start position:0% +uh proof + + + align:start position:0% +uh proof +Pi but importantly this proof should be + + align:start position:0% +Pi but importantly this proof should be + + + align:start position:0% +Pi but importantly this proof should be +small so this Pi is of + + align:start position:0% + + + + align:start position:0% + +size uh poly log or poly in security + + align:start position:0% +size uh poly log or poly in security + + + align:start position:0% +size uh poly log or poly in security +parameter but log K that's + + align:start position:0% +parameter but log K that's + + + align:start position:0% +parameter but log K that's +important okay we want it to depend only + + align:start position:0% +important okay we want it to depend only + + + align:start position:0% +important okay we want it to depend only +Poly arthic on on K that's kind of our + + align:start position:0% +Poly arthic on on K that's kind of our + + + align:start position:0% +Poly arthic on on K that's kind of our +goal okay okay and then maybe ideally + + align:start position:0% +goal okay okay and then maybe ideally + + + align:start position:0% +goal okay okay and then maybe ideally +also log n but the point is we want it + + align:start position:0% +also log n but the point is we want it + + + align:start position:0% +also log n but the point is we want it +to be succinct okay otherwise it's + + align:start position:0% +to be succinct okay otherwise it's + + + align:start position:0% +to be succinct okay otherwise it's +trivial you just output the witnesses + + align:start position:0% +trivial you just output the witnesses + + + align:start position:0% +trivial you just output the witnesses +and the + + align:start position:0% +and the + + + align:start position:0% +and the +verifier takes his input CRS the + + align:start position:0% +verifier takes his input CRS the + + + align:start position:0% +verifier takes his input CRS the +instances and a proof and it output + + align:start position:0% + + + + align:start position:0% + +01 accept or reject okay and this but + + align:start position:0% +01 accept or reject okay and this but + + + align:start position:0% +01 accept or reject okay and this but +when I say the size of the proof is this + + align:start position:0% +when I say the size of the proof is this + + + align:start position:0% +when I say the size of the proof is this +actually you can make it bigger smaller + + align:start position:0% +actually you can make it bigger smaller + + + align:start position:0% +actually you can make it bigger smaller +but we want it to be SU + + align:start position:0% +but we want it to be SU + + + align:start position:0% +but we want it to be SU +okay that's oh sorry I uh sorry I + + align:start position:0% +okay that's oh sorry I uh sorry I + + + align:start position:0% +okay that's oh sorry I uh sorry I +didn't we wanted to depend only + + align:start position:0% +didn't we wanted to depend only + + + align:start position:0% +didn't we wanted to depend only +logarithmically and K so on + + align:start position:0% +logarithmically and K so on + + + align:start position:0% +logarithmically and K so on +but we allow it to depend uh L polom and + + align:start position:0% +but we allow it to depend uh L polom and + + + align:start position:0% +but we allow it to depend uh L polom and +one in one witness okay so I can put it + + align:start position:0% +one in one witness okay so I can put it + + + align:start position:0% +one in one witness okay so I can put it +here a single witness one not many + + align:start position:0% +here a single witness one not many + + + align:start position:0% +here a single witness one not many +ideally we want to be as exing as + + align:start position:0% +ideally we want to be as exing as + + + align:start position:0% +ideally we want to be as exing as +possible but what we can get is a as a + + align:start position:0% +possible but what we can get is a as a + + + align:start position:0% +possible but what we can get is a as a +bar that depends grows with one instance + + align:start position:0% +bar that depends grows with one instance + + + align:start position:0% +bar that depends grows with one instance +one witness as opposed to K + + align:start position:0% +one witness as opposed to K + + + align:start position:0% +one witness as opposed to K +instances okay so uh so this is kind of + + align:start position:0% +instances okay so uh so this is kind of + + + align:start position:0% +instances okay so uh so this is kind of +the the algorithms uh then we want + + align:start position:0% +the the algorithms uh then we want + + + align:start position:0% +the the algorithms uh then we want +completeness and soundness completeness + + align:start position:0% +completeness and soundness completeness + + + align:start position:0% +completeness and soundness completeness +is the usual thing that just says if P + + align:start position:0% +is the usual thing that just says if P + + + align:start position:0% +is the usual thing that just says if P +has valid Witnesses and he generates a + + align:start position:0% +has valid Witnesses and he generates a + + + align:start position:0% +has valid Witnesses and he generates a +bar this bar is going to be accepting + + align:start position:0% +bar this bar is going to be accepting + + + align:start position:0% +bar this bar is going to be accepting +with probability one over kind of the + + align:start position:0% +with probability one over kind of the + + + align:start position:0% +with probability one over kind of the +CRS generation so that's the standard + + align:start position:0% +CRS generation so that's the standard + + + align:start position:0% +CRS generation so that's the standard +completeness and then uh the soundness + + align:start position:0% +completeness and then uh the soundness + + + align:start position:0% +completeness and then uh the soundness +property + + align:start position:0% +property + + + align:start position:0% +property +that uh that we have ideally you would + + align:start position:0% +that uh that we have ideally you would + + + align:start position:0% +that uh that we have ideally you would +want to say that uh so in soundless + + align:start position:0% +want to say that uh so in soundless + + + align:start position:0% +want to say that uh so in soundless +computational soundness we have adaptive + + align:start position:0% +computational soundness we have adaptive + + + align:start position:0% +computational soundness we have adaptive +soundness and nonadaptive soundness and + + align:start position:0% +soundness and nonadaptive soundness and + + + align:start position:0% +soundness and nonadaptive soundness and +we want to we want to say that the a + + align:start position:0% +we want to we want to say that the a + + + align:start position:0% +we want to we want to say that the a +cheating prover cannot convince you of a + + align:start position:0% +cheating prover cannot convince you of a + + + align:start position:0% +cheating prover cannot convince you of a +false statement so he cannot generate he + + align:start position:0% +false statement so he cannot generate he + + + align:start position:0% +false statement so he cannot generate he +cannot give you X's that are not all in + + align:start position:0% +cannot give you X's that are not all in + + + align:start position:0% +cannot give you X's that are not all in +the language with a valid proof that + + align:start position:0% +the language with a valid proof that + + + align:start position:0% +the language with a valid proof that +soundless okay there's an issue is when + + align:start position:0% +soundless okay there's an issue is when + + + align:start position:0% +soundless okay there's an issue is when +does the cheating Pro gets to choose + + align:start position:0% +does the cheating Pro gets to choose + + + align:start position:0% +does the cheating Pro gets to choose +these X's is it before he sees the CRS + + align:start position:0% +these X's is it before he sees the CRS + + + align:start position:0% +these X's is it before he sees the CRS +or after he sees the CRS if he needs to + + align:start position:0% +or after he sees the CRS if he needs to + + + align:start position:0% +or after he sees the CRS if he needs to +decide them before he sees the CRS then + + align:start position:0% +decide them before he sees the CRS then + + + align:start position:0% +decide them before he sees the CRS then +it's non adaptive if you get to decide + + align:start position:0% +it's non adaptive if you get to decide + + + align:start position:0% +it's non adaptive if you get to decide +it after then it's + + align:start position:0% +it after then it's + + + align:start position:0% +it after then it's +adaptive ideally we want to say it's + + align:start position:0% +adaptive ideally we want to say it's + + + align:start position:0% +adaptive ideally we want to say it's +secure for all like very uh all as big + + align:start position:0% +secure for all like very uh all as big + + + align:start position:0% +secure for all like very uh all as big +classes provs as possible and thus we + + align:start position:0% +classes provs as possible and thus we + + + align:start position:0% +classes provs as possible and thus we +would like to have sounds against + + align:start position:0% +would like to have sounds against + + + align:start position:0% +would like to have sounds against +adaptive provs to say even if a cheating + + align:start position:0% +adaptive provs to say even if a cheating + + + align:start position:0% +adaptive provs to say even if a cheating +prover chooses this X1 of XC + + align:start position:0% +prover chooses this X1 of XC + + + align:start position:0% +prover chooses this X1 of XC +adaptably after seeing the CRS if one of + + align:start position:0% +adaptably after seeing the CRS if one of + + + align:start position:0% +adaptably after seeing the CRS if one of +them is false he cannot generate a proof + + align:start position:0% +them is false he cannot generate a proof + + + align:start position:0% +them is false he cannot generate a proof +that's what we would like to say what we + + align:start position:0% +that's what we would like to say what we + + + align:start position:0% +that's what we would like to say what we +can say is what's called a semi adaptive + + align:start position:0% +can say is what's called a semi adaptive + + + align:start position:0% +can say is what's called a semi adaptive +something in between okay so let me just + + align:start position:0% +something in between okay so let me just + + + align:start position:0% +something in between okay so let me just +write it here so semi-adaptive sound + + align:start position:0% + + + + align:start position:0% + +is just says the adversary needs to tell + + align:start position:0% +is just says the adversary needs to tell + + + align:start position:0% +is just says the adversary needs to tell +you which in so he's going to give you K + + align:start position:0% +you which in so he's going to give you K + + + align:start position:0% +you which in so he's going to give you K +instances he can choose them adaptively + + align:start position:0% +instances he can choose them adaptively + + + align:start position:0% +instances he can choose them adaptively +but he needs to choose the ion which is + + align:start position:0% +but he needs to choose the ion which is + + + align:start position:0% +but he needs to choose the ion which is +going to cheat so he's a cheater so one + + align:start position:0% +going to cheat so he's a cheater so one + + + align:start position:0% +going to cheat so he's a cheater so one +of that eyes is not in the + + align:start position:0% +of that eyes is not in the + + + align:start position:0% +of that eyes is not in the +language which ey which location I the + + align:start position:0% +language which ey which location I the + + + align:start position:0% +language which ey which location I the +XI is going to be not in the language + + align:start position:0% +XI is going to be not in the language + + + align:start position:0% +XI is going to be not in the language +that should not depend on the CRS okay + + align:start position:0% +that should not depend on the CRS okay + + + align:start position:0% +that should not depend on the CRS okay +so so it says that for any poly + + align:start position:0% + + + + align:start position:0% + +size P star and for for every I which of + + align:start position:0% +size P star and for for every I which of + + + align:start position:0% +size P star and for for every I which of +course may depend on on Lambda because + + align:start position:0% +course may depend on on Lambda because + + + align:start position:0% +course may depend on on Lambda because +for any Lambda you have an i because the + + align:start position:0% +for any Lambda you have an i because the + + + align:start position:0% +for any Lambda you have an i because the +I is between one and K and K grows with + + align:start position:0% +I is between one and K and K grows with + + + align:start position:0% +I is between one and K and K grows with +can grow with Lambda so for any I you + + align:start position:0% +can grow with Lambda so for any I you + + + align:start position:0% +can grow with Lambda so for any I you +want to say the probability that P star + + align:start position:0% +want to say the probability that P star + + + align:start position:0% +want to say the probability that P star +given a + + align:start position:0% + + + + align:start position:0% + +CRS outputs X1 up to XK and + + align:start position:0% +CRS outputs X1 up to XK and + + + align:start position:0% +CRS outputs X1 up to XK and +Pi such that x i is not in the language + + align:start position:0% +Pi such that x i is not in the language + + + align:start position:0% +Pi such that x i is not in the language +and Pi is accepted is negligible so XI + + align:start position:0% +and Pi is accepted is negligible so XI + + + align:start position:0% +and Pi is accepted is negligible so XI +one of them is the XI one is not in the + + align:start position:0% +one of them is the XI one is not in the + + + align:start position:0% +one of them is the XI one is not in the +language and the I was chosen before he + + align:start position:0% +language and the I was chosen before he + + + align:start position:0% +language and the I was chosen before he +saw the CRS okay so for any P star he + + align:start position:0% +saw the CRS okay so for any P star he + + + align:start position:0% +saw the CRS okay so for any P star he +tells you I'm going to cheat on location + + align:start position:0% +tells you I'm going to cheat on location + + + align:start position:0% +tells you I'm going to cheat on location +I now he's given a CRS the probability + + align:start position:0% +I now he's given a CRS the probability + + + align:start position:0% +I now he's given a CRS the probability +that he gives you an accepting proof for + + align:start position:0% +that he gives you an accepting proof for + + + align:start position:0% +that he gives you an accepting proof for +X on of dek that he chose adaptively + + align:start position:0% +X on of dek that he chose adaptively + + + align:start position:0% +X on of dek that he chose adaptively +after seeing the CRS the probability + + align:start position:0% +after seeing the CRS the probability + + + align:start position:0% +after seeing the CRS the probability +that it's accepting so + + align:start position:0% +that it's accepting so + + + align:start position:0% +that it's accepting so +CRS uh X1 up to XK and Pi is + + align:start position:0% + + + + align:start position:0% + +one and X is not in the language x i is + + align:start position:0% +one and X is not in the language x i is + + + align:start position:0% +one and X is not in the language x i is +not is + + align:start position:0% +not is + + + align:start position:0% +not is +negligible this equals + + align:start position:0% + + + + align:start position:0% + +negligible okay so again for any + + align:start position:0% +negligible okay so again for any + + + align:start position:0% +negligible okay so again for any +cheating prover he needs to ahead of + + align:start position:0% +cheating prover he needs to ahead of + + + align:start position:0% +cheating prover he needs to ahead of +time I'm going to choose my xon XK + + align:start position:0% +time I'm going to choose my xon XK + + + align:start position:0% +time I'm going to choose my xon XK +adaptively after I see the CRS but I'm + + align:start position:0% +adaptively after I see the CRS but I'm + + + align:start position:0% +adaptively after I see the CRS but I'm +going to I'm going to cheat on location + + align:start position:0% +going to I'm going to cheat on location + + + align:start position:0% +going to I'm going to cheat on location +I the probability that he succeeds in + + align:start position:0% +I the probability that he succeeds in + + + align:start position:0% +I the probability that he succeeds in +cheating in location + + align:start position:0% +cheating in location + + + align:start position:0% +cheating in location +I in an accepting way is + + align:start position:0% +I in an accepting way is + + + align:start position:0% +I in an accepting way is +negligible that's the semi-adaptive + + align:start position:0% +negligible that's the semi-adaptive + + + align:start position:0% +negligible that's the semi-adaptive +soundness okay so and uh last class + + align:start position:0% +soundness okay so and uh last class + + + align:start position:0% +soundness okay so and uh last class +jenong kind of showed you the high level + + align:start position:0% +jenong kind of showed you the high level + + + align:start position:0% +jenong kind of showed you the high level +of how you construct such a like the + + align:start position:0% +of how you construct such a like the + + + align:start position:0% +of how you construct such a like the +construction of such a + + align:start position:0% +construction of such a + + + align:start position:0% +construction of such a +bar okay any questions yes uh is piz + + align:start position:0% +bar okay any questions yes uh is piz + + + align:start position:0% +bar okay any questions yes uh is piz +required like the indices other than I + + align:start position:0% +required like the indices other than I + + + align:start position:0% +required like the indices other than I +are those required to be act like in the + + align:start position:0% +are those required to be act like in the + + + align:start position:0% +are those required to be act like in the +language or no no we don't care so yeah + + align:start position:0% +language or no no we don't care so yeah + + + align:start position:0% +language or no no we don't care so yeah +good question so the P star can choose + + align:start position:0% +good question so the P star can choose + + + align:start position:0% +good question so the P star can choose +the rest of the X's however he wants in + + align:start position:0% +the rest of the X's however he wants in + + + align:start position:0% +the rest of the X's however he wants in +the language outside the language + + align:start position:0% +the language outside the language + + + align:start position:0% +the language outside the language +however he + + align:start position:0% +however he + + + align:start position:0% +however he +wants okay but he wins if the XI is not + + align:start position:0% +wants okay but he wins if the XI is not + + + align:start position:0% +wants okay but he wins if the XI is not +in the language and the pi is + + align:start position:0% +in the language and the pi is + + + align:start position:0% +in the language and the pi is +accepting and he wins with probability + + align:start position:0% +accepting and he wins with probability + + + align:start position:0% +accepting and he wins with probability +yes transforming this into fully + + align:start position:0% +yes transforming this into fully + + + align:start position:0% +yes transforming this into fully +adaptive will imply + + align:start position:0% +adaptive will imply + + + align:start position:0% +adaptive will imply +guessing + + align:start position:0% +guessing + + + align:start position:0% +guessing +yeah okay uh good so the question is can + + align:start position:0% +yeah okay uh good so the question is can + + + align:start position:0% +yeah okay uh good so the question is can +why like can we transform this into a + + align:start position:0% +why like can we transform this into a + + + align:start position:0% +why like can we transform this into a +fully adaptive snar so ah converting it + + align:start position:0% +fully adaptive snar so ah converting it + + + align:start position:0% +fully adaptive snar so ah converting it +into a fully adaptive + + align:start position:0% +into a fully adaptive + + + align:start position:0% +into a fully adaptive +snar is um non-trial and I'll tell you + + align:start position:0% +snar is um non-trial and I'll tell you + + + align:start position:0% +snar is um non-trial and I'll tell you +why you can you can guess I you can + + align:start position:0% +why you can you can guess I you can + + + align:start position:0% +why you can you can guess I you can +guess I and you'll guess it correctly + + align:start position:0% +guess I and you'll guess it correctly + + + align:start position:0% +guess I and you'll guess it correctly +with probability one over k + + align:start position:0% +with probability one over k + + + align:start position:0% +with probability one over k +in + + align:start position:0% +in + + + align:start position:0% +in +general but here is so you you can do + + align:start position:0% +general but here is so you you can do + + + align:start position:0% +general but here is so you you can do +the you can do it but here is the issue + + align:start position:0% +the you can do it but here is the issue + + + align:start position:0% +the you can do it but here is the issue +I'll tell you what what um complication + + align:start position:0% +I'll tell you what what um complication + + + align:start position:0% +I'll tell you what what um complication +is in the analysis so I I don't want to + + align:start position:0% +is in the analysis so I I don't want to + + + align:start position:0% +is in the analysis so I I don't want to +recall too much the construction but the + + align:start position:0% +recall too much the construction but the + + + align:start position:0% +recall too much the construction but the +high level idea of how these bars are + + align:start position:0% +high level idea of how these bars are + + + align:start position:0% +high level idea of how these bars are +analyzed even without kind of knowing + + align:start position:0% +analyzed even without kind of knowing + + + align:start position:0% +analyzed even without kind of knowing +the construction uh the way they're + + align:start position:0% +the construction uh the way they're + + + align:start position:0% +the construction uh the way they're +analyzed in this CRS so in the proof in + + align:start position:0% +analyzed in this CRS so in the proof in + + + align:start position:0% +analyzed in this CRS so in the proof in +the analysis we say Suppose there exists + + align:start position:0% +the analysis we say Suppose there exists + + + align:start position:0% +the analysis we say Suppose there exists +some cheating + + align:start position:0% +some cheating + + + align:start position:0% +some cheating +prover that Che on some + + align:start position:0% +prover that Che on some + + + align:start position:0% +prover that Che on some +ey in the + + align:start position:0% +ey in the + + + align:start position:0% +ey in the +CRS I'm going to I'm going to change the + + align:start position:0% +CRS I'm going to I'm going to change the + + + align:start position:0% +CRS I'm going to I'm going to change the +CRS now I'm going to tell the cheating + + align:start position:0% +CRS now I'm going to tell the cheating + + + align:start position:0% +CRS now I'm going to tell the cheating +Pro here's a new CRS and in this new CRS + + align:start position:0% +Pro here's a new CRS and in this new CRS + + + align:start position:0% +Pro here's a new CRS and in this new CRS +I'm going to kind of hardwire I I'm + + align:start position:0% +I'm going to kind of hardwire I I'm + + + align:start position:0% +I'm going to kind of hardwire I I'm +going to put some information about I in + + align:start position:0% +going to put some information about I in + + + align:start position:0% +going to put some information about I in +a way that's + + align:start position:0% +a way that's + + + align:start position:0% +a way that's +unnoticeable okay and when we'll see I'm + + align:start position:0% +unnoticeable okay and when we'll see I'm + + + align:start position:0% +unnoticeable okay and when we'll see I'm +going to call the somewh extractable + + align:start position:0% +going to call the somewh extractable + + + align:start position:0% +going to call the somewh extractable +hash or what J called SSB hash some more + + align:start position:0% +hash or what J called SSB hash some more + + + align:start position:0% +hash or what J called SSB hash some more +statistically binding and then you I'll + + align:start position:0% +statistically binding and then you I'll + + + align:start position:0% +statistically binding and then you I'll +remind you a little bit how we where we + + align:start position:0% +remind you a little bit how we where we + + + align:start position:0% +remind you a little bit how we where we +stick the the index ey but in analysis + + align:start position:0% +stick the the index ey but in analysis + + + align:start position:0% +stick the the index ey but in analysis +we say you know let me change the CRS to + + align:start position:0% +we say you know let me change the CRS to + + + align:start position:0% +we say you know let me change the CRS to +a CRS a different CRS it has a very + + align:start position:0% +a CRS a different CRS it has a very + + + align:start position:0% +a CRS a different CRS it has a very +different distribution but it's + + align:start position:0% +different distribution but it's + + + align:start position:0% +different distribution but it's +indistinguishable it looks the like the + + align:start position:0% +indistinguishable it looks the like the + + + align:start position:0% +indistinguishable it looks the like the +original CRS so P star can't distinguish + + align:start position:0% +original CRS so P star can't distinguish + + + align:start position:0% +original CRS so P star can't distinguish +between the two so he'll still give me a + + align:start position:0% +between the two so he'll still give me a + + + align:start position:0% +between the two so he'll still give me a +valid bar okay and now I'm going to say + + align:start position:0% +valid bar okay and now I'm going to say + + + align:start position:0% +valid bar okay and now I'm going to say +in this new CRS actually there's no way + + align:start position:0% +in this new CRS actually there's no way + + + align:start position:0% +in this new CRS actually there's no way +he can cheat on location I there's no + + align:start position:0% +he can cheat on location I there's no + + + align:start position:0% +he can cheat on location I there's no +way he can cheat okay what is the issue + + align:start position:0% +way he can cheat okay what is the issue + + + align:start position:0% +way he can cheat okay what is the issue +so now you're saying why why do we need + + align:start position:0% +so now you're saying why why do we need + + + align:start position:0% +so now you're saying why why do we need +why can't we do fully + + align:start position:0% +why can't we do fully + + + align:start position:0% +why can't we do fully +adaptive the the issue is it may be the + + align:start position:0% +adaptive the the issue is it may be the + + + align:start position:0% +adaptive the the issue is it may be the +case that once we switch the CRS it + + align:start position:0% +case that once we switch the CRS it + + + align:start position:0% +case that once we switch the CRS it +switches where he's cheating so here's + + align:start position:0% +switches where he's cheating so here's + + + align:start position:0% +switches where he's cheating so here's +an here's an alternative way let's say + + align:start position:0% +an here's an alternative way let's say + + + align:start position:0% +an here's an alternative way let's say +the approver tells you here you know I'm + + align:start position:0% +the approver tells you here you know I'm + + + align:start position:0% +the approver tells you here you know I'm +going to cheat in location I but I can + + align:start position:0% +going to cheat in location I but I can + + + align:start position:0% +going to cheat in location I but I can +be adaptive chosen based on the + + align:start position:0% +be adaptive chosen based on the + + + align:start position:0% +be adaptive chosen based on the +CRS so now in the analysis I'm going to + + align:start position:0% +CRS so now in the analysis I'm going to + + + align:start position:0% +CRS so now in the analysis I'm going to +say I'm GNA guess where he cheated I'm + + align:start position:0% +say I'm GNA guess where he cheated I'm + + + align:start position:0% +say I'm GNA guess where he cheated I'm +GNA say let's guess he cheated location + + align:start position:0% +GNA say let's guess he cheated location + + + align:start position:0% +GNA say let's guess he cheated location +seven I'm GNA hardwire kind of the CRS + + align:start position:0% +seven I'm GNA hardwire kind of the CRS + + + align:start position:0% +seven I'm GNA hardwire kind of the CRS +to depend on this location and then the + + align:start position:0% +to depend on this location and then the + + + align:start position:0% +to depend on this location and then the +cheatting pro doesn't cheat on seven it + + align:start position:0% +cheatting pro doesn't cheat on seven it + + + align:start position:0% +cheatting pro doesn't cheat on seven it +cheat on something else he can kind of + + align:start position:0% +cheat on something else he can kind of + + + align:start position:0% +cheat on something else he can kind of +evade me now you're saying oh if he + + align:start position:0% +evade me now you're saying oh if he + + + align:start position:0% +evade me now you're saying oh if he +cheat something else I can tell I can + + align:start position:0% +cheat something else I can tell I can + + + align:start position:0% +cheat something else I can tell I can +tell the difference so like I shouldn't + + align:start position:0% +tell the difference so like I shouldn't + + + align:start position:0% +tell the difference so like I shouldn't +be able to tell but the thing is you + + align:start position:0% +be able to tell but the thing is you + + + align:start position:0% +be able to tell but the thing is you +don't know what's in the language it's + + align:start position:0% +don't know what's in the language it's + + + align:start position:0% +don't know what's in the language it's +not what's not in the language so the + + align:start position:0% +not what's not in the language so the + + + align:start position:0% +not what's not in the language so the +the problem is whether XI is in the + + align:start position:0% +the problem is whether XI is in the + + + align:start position:0% +the problem is whether XI is in the +language or not in the language can be + + align:start position:0% +language or not in the language can be + + + align:start position:0% +language or not in the language can be +very hard to tell it may + + align:start position:0% +very hard to tell it may + + + align:start position:0% +very hard to tell it may +take and that's why kind of getting + + align:start position:0% +take and that's why kind of getting + + + align:start position:0% +take and that's why kind of getting +adaptive like just guessing is + + align:start position:0% +adaptive like just guessing is + + + align:start position:0% +adaptive like just guessing is +not is not uh good enough because he + + align:start position:0% +not is not uh good enough because he + + + align:start position:0% +not is not uh good enough because he +needs to the the issue is if you could + + align:start position:0% +needs to the the issue is if you could + + + align:start position:0% +needs to the the issue is if you could +tell efficiently whether exi is in the + + align:start position:0% +tell efficiently whether exi is in the + + + align:start position:0% +tell efficiently whether exi is in the +language or not in the language then yes + + align:start position:0% +language or not in the language then yes + + + align:start position:0% +language or not in the language then yes +but because it can be very + + align:start position:0% +but because it can be very + + + align:start position:0% +but because it can be very +hard that's where things become tricky + + align:start position:0% +hard that's where things become tricky + + + align:start position:0% +hard that's where things become tricky +so that's so you can guess but it's not + + align:start position:0% +so that's so you can guess but it's not + + + align:start position:0% +so that's so you can guess but it's not +good enough is is uh the + + align:start position:0% + + + + align:start position:0% + +answer okay any yeah + + align:start position:0% +answer okay any yeah + + + align:start position:0% +answer okay any yeah +even huh even if he commits to + + align:start position:0% +even huh even if he commits to + + + align:start position:0% +even huh even if he commits to +do will that + + align:start position:0% +do will that + + + align:start position:0% +do will that +be well he can com what do you mean he + + align:start position:0% +be well he can com what do you mean he + + + align:start position:0% +be well he can com what do you mean he +commits the so you're saying let's + + align:start position:0% +commits the so you're saying let's + + + align:start position:0% +commits the so you're saying let's +change the scheme kind of and have him + + align:start position:0% +change the scheme kind of and have him + + + align:start position:0% +change the scheme kind of and have him +add commitment + + align:start position:0% +add commitment + + + align:start position:0% +add commitment +or I guess not be + + align:start position:0% +or I guess not be + + + align:start position:0% +or I guess not be +that I I guess the issue is look when + + align:start position:0% +that I I guess the issue is look when + + + align:start position:0% +that I I guess the issue is look when +he's cheating we don't know whether like + + align:start position:0% +he's cheating we don't know whether like + + + align:start position:0% +he's cheating we don't know whether like +he gives you X1 of to XK and and approve + + align:start position:0% +he gives you X1 of to XK and and approve + + + align:start position:0% +he gives you X1 of to XK and and approve +Pi now he cheats if one of them is not + + align:start position:0% +Pi now he cheats if one of them is not + + + align:start position:0% +Pi now he cheats if one of them is not +in the language that's when he cheats + + align:start position:0% +in the language that's when he cheats + + + align:start position:0% +in the language that's when he cheats +it's hard to know whether one of them is + + align:start position:0% +it's hard to know whether one of them is + + + align:start position:0% +it's hard to know whether one of them is +in the language are not in the language + + align:start position:0% +in the language are not in the language + + + align:start position:0% +in the language are not in the language +and the concern is he can say I he can + + align:start position:0% +and the concern is he can say I he can + + + align:start position:0% +and the concern is he can say I he can +say whatever he wants he's going to + + align:start position:0% +say whatever he wants he's going to + + + align:start position:0% +say whatever he wants he's going to +cheat so nothing he says we we we + + align:start position:0% +cheat so nothing he says we we we + + + align:start position:0% +cheat so nothing he says we we we +believe right and the concern is that + + align:start position:0% +believe right and the concern is that + + + align:start position:0% +believe right and the concern is that +maybe when we switch the CRS to kind of + + align:start position:0% +maybe when we switch the CRS to kind of + + + align:start position:0% +maybe when we switch the CRS to kind of +depend on I all the exite becomes in the + + align:start position:0% +depend on I all the exite becomes in the + + + align:start position:0% +depend on I all the exite becomes in the +language and then what do you do and now + + align:start position:0% +language and then what do you do and now + + + align:start position:0% +language and then what do you do and now +you can say you can't tell the + + align:start position:0% +you can say you can't tell the + + + align:start position:0% +you can say you can't tell the +difference because exide in the language + + align:start position:0% +difference because exide in the language + + + align:start position:0% +difference because exide in the language +and outside the language they look the + + align:start position:0% +and outside the language they look the + + + align:start position:0% +and outside the language they look the +same so that's why kind of guessing is + + align:start position:0% +same so that's why kind of guessing is + + + align:start position:0% +same so that's why kind of guessing is +is in some sense not good enough like + + align:start position:0% +is in some sense not good enough like + + + align:start position:0% +is in some sense not good enough like +it's not helpful + + align:start position:0% +it's not helpful + + + align:start position:0% +it's not helpful +okay so this is uh any other + + align:start position:0% + + + + align:start position:0% + +questions okay so this is one ingredient + + align:start position:0% +questions okay so this is one ingredient + + + align:start position:0% +questions okay so this is one ingredient +that we're going to use to construct our + + align:start position:0% +that we're going to use to construct our + + + align:start position:0% +that we're going to use to construct our +snar the other ingredient is uh what's + + align:start position:0% +snar the other ingredient is uh what's + + + align:start position:0% +snar the other ingredient is uh what's +what uh the some extractable hash or SSB + + align:start position:0% +what uh the some extractable hash or SSB + + + align:start position:0% +what uh the some extractable hash or SSB +has so let me write it out I'm going to + + align:start position:0% +has so let me write it out I'm going to + + + align:start position:0% +has so let me write it out I'm going to +write it here uh so we'll keep it on the + + align:start position:0% +write it here uh so we'll keep it on the + + + align:start position:0% +write it here uh so we'll keep it on the +board so that's so let me just recall + + align:start position:0% +board so that's so let me just recall + + + align:start position:0% +board so that's so let me just recall +the + + align:start position:0% +the + + + align:start position:0% +the +definition uh somewhere extractable hash + + align:start position:0% +definition uh somewhere extractable hash + + + align:start position:0% +definition uh somewhere extractable hash +family uh + + align:start position:0% +family uh + + + align:start position:0% +family uh +consists of uh many several PPT + + align:start position:0% +consists of uh many several PPT + + + align:start position:0% +consists of uh many several PPT +algorithm let me start writing so so the + + align:start position:0% +algorithm let me start writing so so the + + + align:start position:0% +algorithm let me start writing so so the +first one is uh + + align:start position:0% +first one is uh + + + align:start position:0% +first one is uh +gen gen so now we're constructing a hash + + align:start position:0% +gen gen so now we're constructing a hash + + + align:start position:0% +gen gen so now we're constructing a hash +okay so gen takes a security + + align:start position:0% +okay so gen takes a security + + + align:start position:0% +okay so gen takes a security +parameter the length how many bits we're + + align:start position:0% +parameter the length how many bits we're + + + align:start position:0% +parameter the length how many bits we're +going to Hash so let's say n Bits we're + + align:start position:0% +going to Hash so let's say n Bits we're + + + align:start position:0% +going to Hash so let's say n Bits we're +going to hash and how many and okay so + + align:start position:0% +going to hash and how many and okay so + + + align:start position:0% +going to hash and how many and okay so +let's say in the location I this is + + align:start position:0% +let's say in the location I this is + + + align:start position:0% +let's say in the location I this is +going to be I and N this is where we're + + align:start position:0% +going to be I and N this is where we're + + + align:start position:0% +going to be I and N this is where we're +going to be binding on or where want to + + align:start position:0% +going to be binding on or where want to + + + align:start position:0% +going to be binding on or where want to +be extractable on and it + + align:start position:0% + + + + align:start position:0% + +outputs a hash key and a trap door this + + align:start position:0% +outputs a hash key and a trap door this + + + align:start position:0% +outputs a hash key and a trap door this +trapid door is going to be we're going + + align:start position:0% +trapid door is going to be we're going + + + align:start position:0% +trapid door is going to be we're going +to use it to kind of extract from the + + align:start position:0% +to use it to kind of extract from the + + + align:start position:0% +to use it to kind of extract from the +hash the I location of what we hashed + + align:start position:0% +hash the I location of what we hashed + + + align:start position:0% +hash the I location of what we hashed +okay so there's a hash key and a trapo I + + align:start position:0% +okay so there's a hash key and a trapo I + + + align:start position:0% +okay so there's a hash key and a trapo I +know when Jen Jen taught it then he just + + align:start position:0% +know when Jen Jen taught it then he just + + + align:start position:0% +know when Jen Jen taught it then he just +said hash key and he put kind of the + + align:start position:0% +said hash key and he put kind of the + + + align:start position:0% +said hash key and he put kind of the +trapo at the end so I'm I'm going to + + align:start position:0% +trapo at the end so I'm I'm going to + + + align:start position:0% +trapo at the end so I'm I'm going to +write it with a + + align:start position:0% +write it with a + + + align:start position:0% +write it with a +trapdoor okay so Jen outputs a hash key + + align:start position:0% +trapdoor okay so Jen outputs a hash key + + + align:start position:0% +trapdoor okay so Jen outputs a hash key +and a trapo and then you have eval + + align:start position:0% +and a trapo and then you have eval + + + align:start position:0% +and a trapo and then you have eval +algorithm it just takes the hash key uh + + align:start position:0% +algorithm it just takes the hash key uh + + + align:start position:0% +algorithm it just takes the hash key uh +uh input X and 01 to the + + align:start position:0% +uh input X and 01 to the + + + align:start position:0% +uh input X and 01 to the +n and then output a hash value + + align:start position:0% +n and then output a hash value + + + align:start position:0% +n and then output a hash value +V uh and then you have + + align:start position:0% +V uh and then you have + + + align:start position:0% +V uh and then you have +open where you take a hash key the X and + + align:start position:0% +open where you take a hash key the X and + + + align:start position:0% +open where you take a hash key the X and +some index J that you want to open + + align:start position:0% +some index J that you want to open + + + align:start position:0% +some index J that you want to open +to and it outputs an opening row or row + + align:start position:0% +to and it outputs an opening row or row + + + align:start position:0% +to and it outputs an opening row or row +J + + align:start position:0% +J + + + align:start position:0% +J +and this should be in 01 to the Lambda + + align:start position:0% +and this should be in 01 to the Lambda + + + align:start position:0% +and this should be in 01 to the Lambda +or poly Lambda similar here this should + + align:start position:0% +or poly Lambda similar here this should + + + align:start position:0% +or poly Lambda similar here this should +be small 01 to the Lambda or poly + + align:start position:0% + + + + align:start position:0% + +Lambda and then there's ver that + + align:start position:0% +Lambda and then there's ver that + + + align:start position:0% +Lambda and then there's ver that +verifies so ver takes a hash key a value + + align:start position:0% +verifies so ver takes a hash key a value + + + align:start position:0% +verifies so ver takes a hash key a value +and now you you let's say you want to + + align:start position:0% +and now you you let's say you want to + + + align:start position:0% +and now you you let's say you want to +say I'm going to open location J here's + + align:start position:0% +say I'm going to open location J here's + + + align:start position:0% +say I'm going to open location J here's +my B that opens and here's the + + align:start position:0% +my B that opens and here's the + + + align:start position:0% +my B that opens and here's the +opening and he checks is it valid + + align:start position:0% +opening and he checks is it valid + + + align:start position:0% +opening and he checks is it valid +opening or not so it + + align:start position:0% + + + + align:start position:0% + +outputs zero or + + align:start position:0% + + + + align:start position:0% + +one and finally so consist of + + align:start position:0% +one and finally so consist of + + + align:start position:0% +one and finally so consist of +five vpt + + align:start position:0% +five vpt + + + align:start position:0% +five vpt +algorithms so first you generate a hash + + align:start position:0% +algorithms so first you generate a hash + + + align:start position:0% +algorithms so first you generate a hash +key with a trapo then uh there's an eval + + align:start position:0% +key with a trapo then uh there's an eval + + + align:start position:0% +key with a trapo then uh there's an eval +algorithm that given nbit string outputs + + align:start position:0% +algorithm that given nbit string outputs + + + align:start position:0% +algorithm that given nbit string outputs +the hash value v short succinct then + + align:start position:0% +the hash value v short succinct then + + + align:start position:0% +the hash value v short succinct then +there's open that you can open given uh + + align:start position:0% +there's open that you can open given uh + + + align:start position:0% +there's open that you can open given uh +that you can generate an opening for + + align:start position:0% +that you can generate an opening for + + + align:start position:0% +that you can generate an opening for +specific index J so you generate row J + + align:start position:0% +specific index J so you generate row J + + + align:start position:0% +specific index J so you generate row J +which is an opening and anybody can + + align:start position:0% +which is an opening and anybody can + + + align:start position:0% +which is an opening and anybody can +verify the opening using only the + + align:start position:0% +verify the opening using only the + + + align:start position:0% +verify the opening using only the +succinct hash value okay so given a hash + + align:start position:0% +succinct hash value okay so given a hash + + + align:start position:0% +succinct hash value okay so given a hash +key the succinct hash value the index + + align:start position:0% +key the succinct hash value the index + + + align:start position:0% +key the succinct hash value the index +the bit you can verify the opening and + + align:start position:0% +the bit you can verify the opening and + + + align:start position:0% +the bit you can verify the opening and +finally that's the extract algorithm + + align:start position:0% + + + + align:start position:0% + +and it takes the + + align:start position:0% +and it takes the + + + align:start position:0% +and it takes the +trapo and the value and it outputs a + + align:start position:0% +trapo and the value and it outputs a + + + align:start position:0% +trapo and the value and it outputs a +bit and this bit should be + + align:start position:0% +bit and this bit should be + + + align:start position:0% +bit and this bit should be +XI okay so let me say the the uh + + align:start position:0% +XI okay so let me say the the uh + + + align:start position:0% +XI okay so let me say the the uh +properties + + align:start position:0% + + + + align:start position:0% + +so the first property is completeness + + align:start position:0% +so the first property is completeness + + + align:start position:0% +so the first property is completeness +that's kind of usually the a + + align:start position:0% +that's kind of usually the a + + + align:start position:0% +that's kind of usually the a +straightforward + + align:start position:0% + + + + align:start position:0% + +property which essentially says look if + + align:start position:0% +property which essentially says look if + + + align:start position:0% +property which essentially says look if +everybody's honest you get what you + + align:start position:0% +everybody's honest you get what you + + + align:start position:0% +everybody's honest you get what you +expect which means one the verifier + + align:start position:0% +expect which means one the verifier + + + align:start position:0% +expect which means one the verifier +would accept the opening and B the + + align:start position:0% +would accept the opening and B the + + + align:start position:0% +would accept the opening and B the +extract will output the I bit so it says + + align:start position:0% +extract will output the I bit so it says + + + align:start position:0% +extract will output the I bit so it says +that the probability okay so for every X + + align:start position:0% +that the probability okay so for every X + + + align:start position:0% +that the probability okay so for every X +for every Lambda for + + align:start position:0% +for every Lambda for + + + align:start position:0% +for every Lambda for +every uh n which is at most two to the + + align:start position:0% +every uh n which is at most two to the + + + align:start position:0% +every uh n which is at most two to the +Lambda we always restrict the length of + + align:start position:0% +Lambda we always restrict the length of + + + align:start position:0% +Lambda we always restrict the length of +what we're we're hashing to be at most 2 + + align:start position:0% +what we're we're hashing to be at most 2 + + + align:start position:0% +what we're we're hashing to be at most 2 +to the + + align:start position:0% +to the + + + align:start position:0% +to the +Lambda and for every + + align:start position:0% + + + + align:start position:0% + +I we say that the + + align:start position:0% + + + + align:start position:0% + +probability that + + align:start position:0% + + + + align:start position:0% + +a open sorry that + + align:start position:0% +a open sorry that + + + align:start position:0% +a open sorry that +there an hash key generated from gen V + + align:start position:0% +there an hash key generated from gen V + + + align:start position:0% +there an hash key generated from gen V +which is + + align:start position:0% +which is + + + align:start position:0% +which is +theal ah and for every + + align:start position:0% + + + + align:start position:0% + +J J row + + align:start position:0% +J J row + + + align:start position:0% +J J row +generated by + + align:start position:0% +generated by + + + align:start position:0% +generated by +open it always outputs one it outputs on + + align:start position:0% +open it always outputs one it outputs on + + + align:start position:0% +open it always outputs one it outputs on +probability one and + + align:start position:0% +probability one and + + + align:start position:0% +probability one and +extract I'll just denote by okay extract + + align:start position:0% +extract I'll just denote by okay extract + + + align:start position:0% +extract I'll just denote by okay extract +let me denote by just X for Simplicity + + align:start position:0% +let me denote by just X for Simplicity + + + align:start position:0% +let me denote by just X for Simplicity +uh given trap door and V output x i and + + align:start position:0% +uh given trap door and V output x i and + + + align:start position:0% +uh given trap door and V output x i and +this hold with probability one where the + + align:start position:0% +this hold with probability one where the + + + align:start position:0% +this hold with probability one where the +probability is over what hash key and + + align:start position:0% +probability is over what hash key and + + + align:start position:0% +probability is over what hash key and +trapo are in gen so essentially I won't + + align:start position:0% +trapo are in gen so essentially I won't + + + align:start position:0% +trapo are in gen so essentially I won't +write it but the hash key is generated + + align:start position:0% +write it but the hash key is generated + + + align:start position:0% +write it but the hash key is generated +by this V is generated by this eval row + + align:start position:0% +by this V is generated by this eval row + + + align:start position:0% +by this V is generated by this eval row +or I'll call row J is + + align:start position:0% +or I'll call row J is + + + align:start position:0% +or I'll call row J is +generated by + + align:start position:0% +generated by + + + align:start position:0% +generated by +open and this just says if if everything + + align:start position:0% +open and this just says if if everything + + + align:start position:0% +open and this just says if if everything +was done correctly the ver always + + align:start position:0% +was done correctly the ver always + + + align:start position:0% +was done correctly the ver always +accepts and the extract indeed will + + align:start position:0% +accepts and the extract indeed will + + + align:start position:0% +accepts and the extract indeed will +extract the correct bit + + align:start position:0% +extract the correct bit + + + align:start position:0% +extract the correct bit +so this is just if everybody follows the + + align:start position:0% +so this is just if everybody follows the + + + align:start position:0% +so this is just if everybody follows the +protocol everything should be as you + + align:start position:0% +protocol everything should be as you + + + align:start position:0% +protocol everything should be as you +expect okay uh the soundness or + + align:start position:0% + + + + align:start position:0% + +binding or the statistical binding I + + align:start position:0% +binding or the statistical binding I + + + align:start position:0% +binding or the statistical binding I +should say somewh or I can call the SSB + + align:start position:0% +should say somewh or I can call the SSB + + + align:start position:0% +should say somewh or I can call the SSB +somewh statistically binding condition + + align:start position:0% +somewh statistically binding condition + + + align:start position:0% +somewh statistically binding condition +says that on + + align:start position:0% +says that on + + + align:start position:0% +says that on +location oh before I go to SSB uh + + align:start position:0% +location oh before I go to SSB uh + + + align:start position:0% +location oh before I go to SSB uh +there's another property which is index + + align:start position:0% + + + + align:start position:0% + +hiding index hiding + + align:start position:0% +hiding index hiding + + + align:start position:0% +hiding index hiding +means that the hash key hides the index + + align:start position:0% +means that the hash key hides the index + + + align:start position:0% +means that the hash key hides the index +okay if you see just hash key you have + + align:start position:0% +okay if you see just hash key you have + + + align:start position:0% +okay if you see just hash key you have +no idea what I is okay so it just says + + align:start position:0% +no idea what I is okay so it just says + + + align:start position:0% +no idea what I is okay so it just says +that for every I and + + align:start position:0% +that for every I and + + + align:start position:0% +that for every I and +J if you look at hash key generated by + + align:start position:0% +J if you look at hash key generated by + + + align:start position:0% +J if you look at hash key generated by +and I'll call it I or hash key generated + + align:start position:0% +and I'll call it I or hash key generated + + + align:start position:0% +and I'll call it I or hash key generated +by J + + align:start position:0% +by J + + + align:start position:0% +by J +they're + + align:start position:0% +they're + + + align:start position:0% +they're +indistinguishable okay this is just a + + align:start position:0% +indistinguishable okay this is just a + + + align:start position:0% +indistinguishable okay this is just a +notation to say hash key generated where + + align:start position:0% +notation to say hash key generated where + + + align:start position:0% +notation to say hash key generated where +here I have I and this is just a + + align:start position:0% +here I have I and this is just a + + + align:start position:0% +here I have I and this is just a +notation saying this is Hash key + + align:start position:0% +notation saying this is Hash key + + + align:start position:0% +notation saying this is Hash key +generated by uh giving J to gen okay so + + align:start position:0% +generated by uh giving J to gen okay so + + + align:start position:0% +generated by uh giving J to gen okay so +this the the hashy HIDs the index for + + align:start position:0% +this the the hashy HIDs the index for + + + align:start position:0% +this the the hashy HIDs the index for +any + + align:start position:0% +any + + + align:start position:0% +any +inj uh the hashy generated with I the + + align:start position:0% +inj uh the hashy generated with I the + + + align:start position:0% +inj uh the hashy generated with I the +has generate J they look the + + align:start position:0% +has generate J they look the + + + align:start position:0% +has generate J they look the +same okay so that's the index hiding and + + align:start position:0% +same okay so that's the index hiding and + + + align:start position:0% +same okay so that's the index hiding and +finally is The Binding + + align:start position:0% +finally is The Binding + + + align:start position:0% +finally is The Binding +condition and The Binding condition says + + align:start position:0% +condition and The Binding condition says + + + align:start position:0% +condition and The Binding condition says +that so the SSB the somewhere + + align:start position:0% +that so the SSB the somewhere + + + align:start position:0% +that so the SSB the somewhere +statistical binding says that for the + + align:start position:0% +statistical binding says that for the + + + align:start position:0% +statistical binding says that for the +location + + align:start position:0% +location + + + align:start position:0% +location +I that we that we're binding on even an + + align:start position:0% +I that we that we're binding on even an + + + align:start position:0% +I that we that we're binding on even an +all powerful adversary that is given + + align:start position:0% +all powerful adversary that is given + + + align:start position:0% +all powerful adversary that is given +hash key cannot generate V and and two + + align:start position:0% +hash key cannot generate V and and two + + + align:start position:0% +hash key cannot generate V and and two +different openings to location I an + + align:start position:0% +different openings to location I an + + + align:start position:0% +different openings to location I an +opening to zero and opening to one on + + align:start position:0% +opening to zero and opening to one on + + + align:start position:0% +opening to zero and opening to one on +location I so on location I you're + + align:start position:0% +location I so on location I you're + + + align:start position:0% +location I so on location I you're +really information theoretically bounded + + align:start position:0% +really information theoretically bounded + + + align:start position:0% +really information theoretically bounded +okay so again even in all powerful + + align:start position:0% +okay so again even in all powerful + + + align:start position:0% +okay so again even in all powerful +adversary that is given hash key with + + align:start position:0% +adversary that is given hash key with + + + align:start position:0% +adversary that is given hash key with +respect to a i on location I cannot open + + align:start position:0% +respect to a i on location I cannot open + + + align:start position:0% +respect to a i on location I cannot open +both to zero and to one except with Neal + + align:start position:0% +both to zero and to one except with Neal + + + align:start position:0% +both to zero and to one except with Neal +probability Okay so ah I hoped to put + + align:start position:0% +probability Okay so ah I hoped to put + + + align:start position:0% +probability Okay so ah I hoped to put +everything on that but I I'll I'll add + + align:start position:0% +everything on that but I I'll I'll add + + + align:start position:0% +everything on that but I I'll I'll add +one here so I'll put here The Binding + + align:start position:0% +one here so I'll put here The Binding + + + align:start position:0% +one here so I'll put here The Binding +condition so the SSB + + align:start position:0% + + + + align:start position:0% + +binding The summ Binding says that for + + align:start position:0% +binding The summ Binding says that for + + + align:start position:0% +binding The summ Binding says that for +every all + + align:start position:0% + + + + align:start position:0% + +powerful adversary a the probability + + align:start position:0% +powerful adversary a the probability + + + align:start position:0% +powerful adversary a the probability +that a and hash key where hash key is + + align:start position:0% +that a and hash key where hash key is + + + align:start position:0% +that a and hash key where hash key is +generated + + align:start position:0% +generated + + + align:start position:0% +generated +from + + align:start position:0% +from + + + align:start position:0% +from +gen 1 Lambda n and I the probability + + align:start position:0% +gen 1 Lambda n and I the probability + + + align:start position:0% +gen 1 Lambda n and I the probability +that he outputs any value + + align:start position:0% +that he outputs any value + + + align:start position:0% +that he outputs any value +V and row zero and Row + + align:start position:0% + + + + align:start position:0% + +one such that there would accept both so + + align:start position:0% +one such that there would accept both so + + + align:start position:0% +one such that there would accept both so +that for every B both zero and + + align:start position:0% +that for every B both zero and + + + align:start position:0% +that for every B both zero and +one there on hash key v i b Robby + + align:start position:0% +one there on hash key v i b Robby + + + align:start position:0% +one there on hash key v i b Robby +outputs one this is + + align:start position:0% + + + + align:start position:0% + +negligible okay so + + align:start position:0% +negligible okay so + + + align:start position:0% +negligible okay so +on on index I the one that we're the + + align:start position:0% +on on index I the one that we're the + + + align:start position:0% +on on index I the one that we're the +hatch came from that we're binding on he + + align:start position:0% +hatch came from that we're binding on he + + + align:start position:0% +hatch came from that we're binding on he +cannot open to both zero and open to one + + align:start position:0% +cannot open to both zero and open to one + + + align:start position:0% +cannot open to both zero and open to one +uh in an accepting way with uh accept + + align:start position:0% +uh in an accepting way with uh accept + + + align:start position:0% +uh in an accepting way with uh accept +probability yeah does have to be + + align:start position:0% +probability yeah does have to be + + + align:start position:0% +probability yeah does have to be +generated from eval here or no good good + + align:start position:0% +generated from eval here or no good good + + + align:start position:0% +generated from eval here or no good good +good good great question V malicious + + align:start position:0% +good good great question V malicious + + + align:start position:0% +good good great question V malicious +there's no a can be so the adversary + + align:start position:0% +there's no a can be so the adversary + + + align:start position:0% +there's no a can be so the adversary +he's not following any guidelines he's + + align:start position:0% +he's not following any guidelines he's + + + align:start position:0% +he's not following any guidelines he's +completely malicious he generates V + + align:start position:0% +completely malicious he generates V + + + align:start position:0% +completely malicious he generates V +according to his own will generating row + + align:start position:0% +according to his own will generating row + + + align:start position:0% +according to his own will generating row +zero and Row one however he wants he's + + align:start position:0% +zero and Row one however he wants he's + + + align:start position:0% +zero and Row one however he wants he's +still and he's all powerful he's still + + align:start position:0% +still and he's all powerful he's still + + + align:start position:0% +still and he's all powerful he's still +cannot uh generate two accepting + + align:start position:0% +cannot uh generate two accepting + + + align:start position:0% +cannot uh generate two accepting +openings for location + + align:start position:0% +openings for location + + + align:start position:0% +openings for location +I yeah just to follow up on that that's + + align:start position:0% +I yeah just to follow up on that that's + + + align:start position:0% +I yeah just to follow up on that that's +the only reason that we don't get this + + align:start position:0% +the only reason that we don't get this + + + align:start position:0% +the only reason that we don't get this +free from extraction right exactly good + + align:start position:0% +free from extraction right exactly good + + + align:start position:0% +free from extraction right exactly good +good good very good so let me just uh uh + + align:start position:0% +good good very good so let me just uh uh + + + align:start position:0% +good good very good so let me just uh uh +uh repeat what s said look in extraction + + align:start position:0% +uh repeat what s said look in extraction + + + align:start position:0% +uh repeat what s said look in extraction +we said that we're binding completely + + align:start position:0% +we said that we're binding completely + + + align:start position:0% +we said that we're binding completely +binding because guess what from V we can + + align:start position:0% +binding because guess what from V we can + + + align:start position:0% +binding because guess what from V we can +actually uh we can actually learn the + + align:start position:0% +actually uh we can actually learn the + + + align:start position:0% +actually uh we can actually learn the +the bit XI so XI is sitting there so + + align:start position:0% +the bit XI so XI is sitting there so + + + align:start position:0% +the bit XI so XI is sitting there so +yeah if you're honest XI is sitting + + align:start position:0% +yeah if you're honest XI is sitting + + + align:start position:0% +yeah if you're honest XI is sitting +there but if you're malicious you know + + align:start position:0% +there but if you're malicious you know + + + align:start position:0% +there but if you're malicious you know +you can do whatever you want and maybe + + align:start position:0% +you can do whatever you want and maybe + + + align:start position:0% +you can do whatever you want and maybe +if for malicious V maybe there's no you + + align:start position:0% +if for malicious V maybe there's no you + + + align:start position:0% +if for malicious V maybe there's no you +can't extract anything from + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +yeah right good good good very good yes + + align:start position:0% +yeah right good good good very good yes + + + align:start position:0% +yeah right good good good very good yes +yes yes this is the same as saying that + + align:start position:0% +yes yes this is the same as saying that + + + align:start position:0% +yes yes this is the same as saying that +there exists a + + align:start position:0% +there exists a + + + align:start position:0% +there exists a +v row zero for any H okay for almost all + + align:start position:0% +v row zero for any H okay for almost all + + + align:start position:0% +v row zero for any H okay for almost all +hash Keys the probability that there + + align:start position:0% +hash Keys the probability that there + + + align:start position:0% +hash Keys the probability that there +exists v r z and R1 is is is uh zero + + align:start position:0% +exists v r z and R1 is is is uh zero + + + align:start position:0% +exists v r z and R1 is is is uh zero +they don't exist for almost all hash + + align:start position:0% +they don't exist for almost all hash + + + align:start position:0% +they don't exist for almost all hash +keys this triplet that satisfies this + + align:start position:0% +keys this triplet that satisfies this + + + align:start position:0% +keys this triplet that satisfies this +does not exist yes yeah very + + align:start position:0% +does not exist yes yeah very + + + align:start position:0% +does not exist yes yeah very +good any any other + + align:start position:0% +good any any other + + + align:start position:0% +good any any other +questions okay so the plan for today is + + align:start position:0% +questions okay so the plan for today is + + + align:start position:0% +questions okay so the plan for today is +to show how to use these two building + + align:start position:0% +to show how to use these two building + + + align:start position:0% +to show how to use these two building +blocks to get a snar but before I do + + align:start position:0% +blocks to get a snar but before I do + + + align:start position:0% +blocks to get a snar but before I do +that I want to say a few more to first I + + align:start position:0% +that I want to say a few more to first I + + + align:start position:0% +that I want to say a few more to first I +want to give you time to digest and ask + + align:start position:0% +want to give you time to digest and ask + + + align:start position:0% +want to give you time to digest and ask +questions uh also I want to say a few + + align:start position:0% +questions uh also I want to say a few + + + align:start position:0% +questions uh also I want to say a few +more things about these two Primitives + + align:start position:0% + + + + align:start position:0% + +any questions before + + align:start position:0% +any questions before + + + align:start position:0% +any questions before +I okay so one thing I want to mention is + + align:start position:0% +I okay so one thing I want to mention is + + + align:start position:0% +I okay so one thing I want to mention is +even though the binding condition was + + align:start position:0% +even though the binding condition was + + + align:start position:0% +even though the binding condition was +only an I I said only on the specific + + align:start position:0% +only an I I said only on the specific + + + align:start position:0% +only an I I said only on the specific +eye I promise you you can't open two + + align:start position:0% +eye I promise you you can't open two + + + align:start position:0% +eye I promise you you can't open two +different ways now say what about the + + align:start position:0% +different ways now say what about the + + + align:start position:0% +different ways now say what about the +other eye what about J Jay can an ADV + + align:start position:0% +other eye what about J Jay can an ADV + + + align:start position:0% +other eye what about J Jay can an ADV +open two different + + align:start position:0% + + + + align:start position:0% + +ways and the answer is no actually he + + align:start position:0% +ways and the answer is no actually he + + + align:start position:0% +ways and the answer is no actually he +can't and we don't need to state that + + align:start position:0% +can't and we don't need to state that + + + align:start position:0% +can't and we don't need to state that +explicitly from from the SSB and the + + align:start position:0% +explicitly from from the SSB and the + + + align:start position:0% +explicitly from from the SSB and the +index hiding I want to argue already we + + align:start position:0% +index hiding I want to argue already we + + + align:start position:0% +index hiding I want to argue already we +can + + align:start position:0% +can + + + align:start position:0% +can +conclude that a poliz + + align:start position:0% +conclude that a poliz + + + align:start position:0% +conclude that a poliz +adversary cannot open a poze not all + + align:start position:0% +adversary cannot open a poze not all + + + align:start position:0% +adversary cannot open a poze not all +powerful but a poliz + + align:start position:0% +powerful but a poliz + + + align:start position:0% +powerful but a poliz +adversary cannot generate V any index + + align:start position:0% +adversary cannot generate V any index + + + align:start position:0% +adversary cannot generate V any index +J and two + + align:start position:0% +J and two + + + align:start position:0% +J and two +openings that will be accepted except NE + + align:start position:0% +openings that will be accepted except NE + + + align:start position:0% +openings that will be accepted except NE +probability + + align:start position:0% +probability + + + align:start position:0% +probability +okay so in other words I'm saying + + align:start position:0% +okay so in other words I'm saying + + + align:start position:0% +okay so in other words I'm saying +binding holes this local binding holes + + align:start position:0% +binding holes this local binding holes + + + align:start position:0% +binding holes this local binding holes +for every J not against all powerful but + + align:start position:0% +for every J not against all powerful but + + + align:start position:0% +for every J not against all powerful but +for any PPT or poly sizing we get this + + align:start position:0% +for any PPT or poly sizing we get this + + + align:start position:0% +for any PPT or poly sizing we get this +binding condition for every + + align:start position:0% + + + + align:start position:0% + +J + + align:start position:0% + + + + align:start position:0% + +why so because of the index hiding + + align:start position:0% +why so because of the index hiding + + + align:start position:0% +why so because of the index hiding +property where we cannot distinguish + + align:start position:0% +property where we cannot distinguish + + + align:start position:0% +property where we cannot distinguish +like index I or something else precisely + + align:start position:0% +like index I or something else precisely + + + align:start position:0% +like index I or something else precisely +so the reason is this a he doesn't know + + align:start position:0% +so the reason is this a he doesn't know + + + align:start position:0% +so the reason is this a he doesn't know +if hash key came from index I or index J + + align:start position:0% +if hash key came from index I or index J + + + align:start position:0% +if hash key came from index I or index J +they're they're indistinguishable so now + + align:start position:0% +they're they're indistinguishable so now + + + align:start position:0% +they're they're indistinguishable so now +if he can generate it for index + + align:start position:0% +if he can generate it for index + + + align:start position:0% +if he can generate it for index +J then he should be able to generate + + align:start position:0% +J then he should be able to generate + + + align:start position:0% +J then he should be able to generate +also for index so let's replace this + + align:start position:0% +also for index so let's replace this + + + align:start position:0% +also for index so let's replace this +with an J he can't distinguish so he'll + + align:start position:0% +with an J he can't distinguish so he'll + + + align:start position:0% +with an J he can't distinguish so he'll +fall in the same J again at some point + + align:start position:0% +fall in the same J again at some point + + + align:start position:0% +fall in the same J again at some point +and that that'll be a + + align:start position:0% +and that that'll be a + + + align:start position:0% +and that that'll be a +contradiction okay so because he has no + + align:start position:0% +contradiction okay so because he has no + + + align:start position:0% +contradiction okay so because he has no +idea what's sitting here the fact that + + align:start position:0% +idea what's sitting here the fact that + + + align:start position:0% +idea what's sitting here the fact that +he cannot do it for that index I even + + align:start position:0% +he cannot do it for that index I even + + + align:start position:0% +he cannot do it for that index I even +information theoretically means he can't + + align:start position:0% +information theoretically means he can't + + + align:start position:0% +information theoretically means he can't +do it for for any other + + align:start position:0% +do it for for any other + + + align:start position:0% +do it for for any other +index yeah so this indexing really + + align:start position:0% +index yeah so this indexing really + + + align:start position:0% +index yeah so this indexing really +statistical no this index hiding is + + align:start position:0% +statistical no this index hiding is + + + align:start position:0% +statistical no this index hiding is +computational + + align:start position:0% +computational + + + align:start position:0% +computational +actually oh good good good good so the + + align:start position:0% +actually oh good good good good so the + + + align:start position:0% +actually oh good good good good so the +corollary + + align:start position:0% +corollary + + + align:start position:0% +corollary +is for any poly + + align:start position:0% +is for any poly + + + align:start position:0% +is for any poly +size the cor say is that for only any + + align:start position:0% +size the cor say is that for only any + + + align:start position:0% +size the cor say is that for only any +poly size a the + + align:start position:0% +poly size a the + + + align:start position:0% +poly size a the +probability that a on hash key let's say + + align:start position:0% +probability that a on hash key let's say + + + align:start position:0% +probability that a on hash key let's say +from I same hash key outputs V or v j + + align:start position:0% +from I same hash key outputs V or v j + + + align:start position:0% +from I same hash key outputs V or v j +row zero and Row + + align:start position:0% +row zero and Row + + + align:start position:0% +row zero and Row +one such that the same thing here holds + + align:start position:0% +one such that the same thing here holds + + + align:start position:0% +one such that the same thing here holds +namely for every B he generates + + align:start position:0% +namely for every B he generates + + + align:start position:0% +namely for every B he generates +accepting answers for both zero and one + + align:start position:0% +accepting answers for both zero and one + + + align:start position:0% +accepting answers for both zero and one +is + + align:start position:0% + + + + align:start position:0% + +negligible because if there exist some J + + align:start position:0% +negligible because if there exist some J + + + align:start position:0% +negligible because if there exist some J +that he does that for non- Negal + + align:start position:0% +that he does that for non- Negal + + + align:start position:0% +that he does that for non- Negal +probability then let's replate replace + + align:start position:0% +probability then let's replate replace + + + align:start position:0% +probability then let's replate replace +HK with hash key generating like that's + + align:start position:0% +HK with hash key generating like that's + + + align:start position:0% +HK with hash key generating like that's +binding on this that actually + + align:start position:0% +binding on this that actually + + + align:start position:0% +binding on this that actually +statistically binding on this J A can + + align:start position:0% +statistically binding on this J A can + + + align:start position:0% +statistically binding on this J A can +distinguish so we'll still do this for + + align:start position:0% +distinguish so we'll still do this for + + + align:start position:0% +distinguish so we'll still do this for +that J with some prob non- negligent + + align:start position:0% +that J with some prob non- negligent + + + align:start position:0% +that J with some prob non- negligent +probability and that he cannot do even + + align:start position:0% +probability and that he cannot do even + + + align:start position:0% +probability and that he cannot do even +information + + align:start position:0% +information + + + align:start position:0% +information +theoretically so that's why we get like + + align:start position:0% +theoretically so that's why we get like + + + align:start position:0% +theoretically so that's why we get like +because index hiding actually just + + align:start position:0% +because index hiding actually just + + + align:start position:0% +because index hiding actually just +getting statistically binding on one of + + align:start position:0% +getting statistically binding on one of + + + align:start position:0% +getting statistically binding on one of +them is good enough it will imply + + align:start position:0% +them is good enough it will imply + + + align:start position:0% +them is good enough it will imply +computational binding and all the + + align:start position:0% +computational binding and all the + + + align:start position:0% +computational binding and all the +rest okay another thing I want to + + align:start position:0% +rest okay another thing I want to + + + align:start position:0% +rest okay another thing I want to +mention and this we'll use actually in + + align:start position:0% +mention and this we'll use actually in + + + align:start position:0% +mention and this we'll use actually in +our construction + + align:start position:0% +our construction + + + align:start position:0% +our construction +today I said that the hash is binding on + + align:start position:0% +today I said that the hash is binding on + + + align:start position:0% +today I said that the hash is binding on +one location and XI we can get it + + align:start position:0% +one location and XI we can get it + + + align:start position:0% +one location and XI we can get it +binding actually on L locations not just + + align:start position:0% +binding actually on L locations not just + + + align:start position:0% +binding actually on L locations not just +one how do I get it binding on L + + align:start position:0% +one how do I get it binding on L + + + align:start position:0% +one how do I get it binding on L +locations I'm going to just generate hk1 + + align:start position:0% +locations I'm going to just generate hk1 + + + align:start position:0% +locations I'm going to just generate hk1 +hk2 up to hkl where the first L is Bing + + align:start position:0% +hk2 up to hkl where the first L is Bing + + + align:start position:0% +hk2 up to hkl where the first L is Bing +on the first I'm just going to + + align:start position:0% +on the first I'm just going to + + + align:start position:0% +on the first I'm just going to +generate L + + align:start position:0% +generate L + + + align:start position:0% +generate L +hashes I'm going to ask to generate the + + align:start position:0% +hashes I'm going to ask to generate the + + + align:start position:0% +hashes I'm going to ask to generate the +AAL on all these hashes so the hash + + align:start position:0% +AAL on all these hashes so the hash + + + align:start position:0% +AAL on all these hashes so the hash +value now is going to be V1 up to VL + + align:start position:0% +value now is going to be V1 up to VL + + + align:start position:0% +value now is going to be V1 up to VL +where the honest uh evalid is going to + + align:start position:0% +where the honest uh evalid is going to + + + align:start position:0% +where the honest uh evalid is going to +take X you want to hash and do eval hk1 + + align:start position:0% +take X you want to hash and do eval hk1 + + + align:start position:0% +take X you want to hash and do eval hk1 +of X eval hk2 of X so just hash the same + + align:start position:0% +of X eval hk2 of X so just hash the same + + + align:start position:0% +of X eval hk2 of X so just hash the same +x with all L keys so now the hatch value + + align:start position:0% +x with all L keys so now the hatch value + + + align:start position:0% +x with all L keys so now the hatch value +is Grows by a factor of L and then when + + align:start position:0% +is Grows by a factor of L and then when + + + align:start position:0% +is Grows by a factor of L and then when +you open a certain bit a certain + + align:start position:0% +you open a certain bit a certain + + + align:start position:0% +you open a certain bit a certain +location you'll generate all the + + align:start position:0% +location you'll generate all the + + + align:start position:0% +location you'll generate all the +openings so just do the same thing kind + + align:start position:0% +openings so just do the same thing kind + + + align:start position:0% +openings so just do the same thing kind +of all times just repeat it all times + + align:start position:0% +of all times just repeat it all times + + + align:start position:0% +of all times just repeat it all times +and now what do we have from that if you + + align:start position:0% +and now what do we have from that if you + + + align:start position:0% +and now what do we have from that if you +by repeating our time so let me uh write + + align:start position:0% +by repeating our time so let me uh write + + + align:start position:0% +by repeating our time so let me uh write +it + + align:start position:0% + + + + align:start position:0% + +so uh let me erase the quary so I'll + + align:start position:0% +so uh let me erase the quary so I'll + + + align:start position:0% +so uh let me erase the quary so I'll +have + + align:start position:0% + + + + align:start position:0% + +room + + align:start position:0% +room + + + align:start position:0% +room +so uh no + + align:start position:0% + + + + align:start position:0% + +remark by repeating + + align:start position:0% + + + + align:start position:0% + +L + + align:start position:0% + + + + align:start position:0% + +times we + + align:start position:0% +times we + + + align:start position:0% +times we +get uh somewhere extractable hash that's + + align:start position:0% + + + + align:start position:0% + +extractable on L + + align:start position:0% + + + + align:start position:0% + +locations and moreover another property + + align:start position:0% +locations and moreover another property + + + align:start position:0% +locations and moreover another property +that's we're going to need even if I + + align:start position:0% +that's we're going to need even if I + + + align:start position:0% +that's we're going to need even if I +let's say gave you the trapo + + align:start position:0% +let's say gave you the trapo + + + align:start position:0% +let's say gave you the trapo +corresponding to some of the alloc not + + align:start position:0% +corresponding to some of the alloc not + + + align:start position:0% +corresponding to some of the alloc not +all the allocations let's say gave you + + align:start position:0% +all the allocations let's say gave you + + + align:start position:0% +all the allocations let's say gave you +trap door one trap door two and trap + + align:start position:0% +trap door one trap door two and trap + + + align:start position:0% +trap door one trap door two and trap +door + + align:start position:0% +door + + + align:start position:0% +door +three still what's in the location + + align:start position:0% +three still what's in the location + + + align:start position:0% +three still what's in the location +hidden in hq4 you have no idea what it + + align:start position:0% +hidden in hq4 you have no idea what it + + + align:start position:0% +hidden in hq4 you have no idea what it +is so even if I reveal some of the trap + + align:start position:0% +is so even if I reveal some of the trap + + + align:start position:0% +is so even if I reveal some of the trap +doors the other IND indic sees remain + + align:start position:0% +doors the other IND indic sees remain + + + align:start position:0% +doors the other IND indic sees remain +hidden okay and we're going to use this + + align:start position:0% +hidden okay and we're going to use this + + + align:start position:0% +hidden okay and we're going to use this +property okay so again if we repeat all + + align:start position:0% +property okay so again if we repeat all + + + align:start position:0% +property okay so again if we repeat all +times we're binding an L location + + align:start position:0% +times we're binding an L location + + + align:start position:0% +times we're binding an L location +but even if I destroy I kind of reveal + + align:start position:0% +but even if I destroy I kind of reveal + + + align:start position:0% +but even if I destroy I kind of reveal +the trapo corresponding to I don't know + + align:start position:0% +the trapo corresponding to I don't know + + + align:start position:0% +the trapo corresponding to I don't know +location to a couple + + align:start position:0% +location to a couple + + + align:start position:0% +location to a couple +locations the rest of the so of course + + align:start position:0% +locations the rest of the so of course + + + align:start position:0% +locations the rest of the so of course +if I give you the trapo then all bets + + align:start position:0% +if I give you the trapo then all bets + + + align:start position:0% +if I give you the trapo then all bets +are off you learn everything you learn + + align:start position:0% +are off you learn everything you learn + + + align:start position:0% +are off you learn everything you learn +the eye you learn everything that's + + align:start position:0% +the eye you learn everything that's + + + align:start position:0% +the eye you learn everything that's +that's the trapo our trap doors are such + + align:start position:0% +that's the trapo our trap doors are such + + + align:start position:0% +that's the trapo our trap doors are such +that once I give you the trap door you + + align:start position:0% +that once I give you the trap door you + + + align:start position:0% +that once I give you the trap door you +learn the index you learn + + align:start position:0% +learn the index you learn + + + align:start position:0% +learn the index you learn +everything but the other indices that + + align:start position:0% +everything but the other indices that + + + align:start position:0% +everything but the other indices that +are not in the not corresponding to the + + align:start position:0% +are not in the not corresponding to the + + + align:start position:0% +are not in the not corresponding to the +trap doors that I give that I gave are + + align:start position:0% +trap doors that I give that I gave are + + + align:start position:0% +trap doors that I give that I gave are +still completely hidden CU I did them + + align:start position:0% +still completely hidden CU I did them + + + align:start position:0% +still completely hidden CU I did them +completely in + + align:start position:0% +completely in + + + align:start position:0% +completely in +independent and this is something we're + + align:start position:0% +independent and this is something we're + + + align:start position:0% +independent and this is something we're +going to use when we're going to + + align:start position:0% +going to use when we're going to + + + align:start position:0% +going to use when we're going to +construct our + + align:start position:0% + + + + align:start position:0% + +snars okay so that's one thing we're + + align:start position:0% +snars okay so that's one thing we're + + + align:start position:0% +snars okay so that's one thing we're +going to use a I I want to mention a + + align:start position:0% +going to use a I I want to mention a + + + align:start position:0% +going to use a I I want to mention a +little I want to talk a little bit about + + align:start position:0% +little I want to talk a little bit about + + + align:start position:0% +little I want to talk a little bit about +the construction because I think maybe + + align:start position:0% +the construction because I think maybe + + + align:start position:0% +the construction because I think maybe +in Jen jang's uh lecture last time this + + align:start position:0% +in Jen jang's uh lecture last time this + + + align:start position:0% +in Jen jang's uh lecture last time this +was missed a little because he said it I + + align:start position:0% +was missed a little because he said it I + + + align:start position:0% +was missed a little because he said it I +think a little too fast so I want to say + + align:start position:0% +think a little too fast so I want to say + + + align:start position:0% +think a little too fast so I want to say +a few words about the construction but + + align:start position:0% +a few words about the construction but + + + align:start position:0% +a few words about the construction but +before I talk about the construction I + + align:start position:0% +before I talk about the construction I + + + align:start position:0% +before I talk about the construction I +want to say one more property about the + + align:start position:0% +want to say one more property about the + + + align:start position:0% +want to say one more property about the +bar that we're going to also use so what + + align:start position:0% +bar that we're going to also use so what + + + align:start position:0% +bar that we're going to also use so what +we're going to use about the bar so we + + align:start position:0% +we're going to use about the bar so we + + + align:start position:0% +we're going to use about the bar so we +said that these gen p and v are + + align:start position:0% +said that these gen p and v are + + + align:start position:0% +said that these gen p and v are +polinomial time algorithm probabilistic + + align:start position:0% +polinomial time algorithm probabilistic + + + align:start position:0% +polinomial time algorithm probabilistic +polinomial time algorithms in particular + + align:start position:0% +polinomial time algorithms in particular + + + align:start position:0% +polinomial time algorithms in particular +V I want to talk about v v is a + + align:start position:0% +V I want to talk about v v is a + + + align:start position:0% +V I want to talk about v v is a +polinomial Time algorithm but V's input + + align:start position:0% +polinomial Time algorithm but V's input + + + align:start position:0% +polinomial Time algorithm but V's input +is really large it has X1 up to XK so + + align:start position:0% +is really large it has X1 up to XK so + + + align:start position:0% +is really large it has X1 up to XK so +poom time means it runs at least in time + + align:start position:0% +poom time means it runs at least in time + + + align:start position:0% +poom time means it runs at least in time +poly K it needs to read its + + align:start position:0% +poly K it needs to read its + + + align:start position:0% +poly K it needs to read its +input ever turns out that the bars we + + align:start position:0% +input ever turns out that the bars we + + + align:start position:0% +input ever turns out that the bars we +have this is what J called bar for index + + align:start position:0% +have this is what J called bar for index + + + align:start position:0% +have this is what J called bar for index +languages if there exists a suing + + align:start position:0% +languages if there exists a suing + + + align:start position:0% +languages if there exists a suing +description of these X1 of to XK the + + align:start position:0% +description of these X1 of to XK the + + + align:start position:0% +description of these X1 of to XK the +verifier only needs to run in time that + + align:start position:0% +verifier only needs to run in time that + + + align:start position:0% +verifier only needs to run in time that +depends on the description in other + + align:start position:0% +depends on the description in other + + + align:start position:0% +depends on the description in other +words we can replace so uh + + align:start position:0% +words we can replace so uh + + + align:start position:0% +words we can replace so uh +if I didn't bring + + align:start position:0% +if I didn't bring + + + align:start position:0% +if I didn't bring +my okay I forgot to bring my colorful uh + + align:start position:0% +my okay I forgot to bring my colorful uh + + + align:start position:0% +my okay I forgot to bring my colorful uh +chalk so uh sorry but at least you have + + align:start position:0% +chalk so uh sorry but at least you have + + + align:start position:0% +chalk so uh sorry but at least you have +cookies I mean what would you prefer + + align:start position:0% +cookies I mean what would you prefer + + + align:start position:0% +cookies I mean what would you prefer +colorful chalks or + + align:start position:0% +colorful chalks or + + + align:start position:0% +colorful chalks or +cookies so if a if you can generate + + align:start position:0% +cookies so if a if you can generate + + + align:start position:0% +cookies so if a if you can generate +these X1 up to XK if there's kind of + + align:start position:0% +these X1 up to XK if there's kind of + + + align:start position:0% +these X1 up to XK if there's kind of +succinct + + align:start position:0% +succinct + + + align:start position:0% +succinct +description then the verify runs in + + align:start position:0% +description then the verify runs in + + + align:start position:0% +description then the verify runs in +polinomial time in the description okay + + align:start position:0% +polinomial time in the description okay + + + align:start position:0% +polinomial time in the description okay +so if let's say there exists some + + align:start position:0% +so if let's say there exists some + + + align:start position:0% +so if let's say there exists some +machine + + align:start position:0% +machine + + + align:start position:0% +machine +M such + + align:start position:0% +M such + + + align:start position:0% +M such +that for every I + + align:start position:0% + + + + align:start position:0% + +XI is just kind of the train + + align:start position:0% +XI is just kind of the train + + + align:start position:0% +XI is just kind of the train +machine on on input I so this kind of + + align:start position:0% +machine on on input I so this kind of + + + align:start position:0% +machine on on input I so this kind of +machine you can you should think this + + align:start position:0% +machine you can you should think this + + + align:start position:0% +machine you can you should think this +algorithm you should think of has kind + + align:start position:0% +algorithm you should think of has kind + + + align:start position:0% +algorithm you should think of has kind +of a succinct description of all the X + + align:start position:0% +of a succinct description of all the X + + + align:start position:0% +of a succinct description of all the X +on up to x k and you give him I you get + + align:start position:0% +on up to x k and you give him I you get + + + align:start position:0% +on up to x k and you give him I you get +it it gives you the X I if this is the + + align:start position:0% +it it gives you the X I if this is the + + + align:start position:0% +it it gives you the X I if this is the +case + + align:start position:0% +case + + + align:start position:0% +case +then V the runtime + + align:start position:0% +then V the runtime + + + align:start position:0% +then V the runtime +or I say + + align:start position:0% +or I say + + + align:start position:0% +or I say +time of v it grows with with the size of + + align:start position:0% +time of v it grows with with the size of + + + align:start position:0% +time of v it grows with with the size of +M as opposed to + + align:start position:0% +M as opposed to + + + align:start position:0% +M as opposed to +K okay so the + + align:start position:0% + + + + align:start position:0% + +grows with M and does not grow with K so + + align:start position:0% +grows with M and does not grow with K so + + + align:start position:0% +grows with M and does not grow with K so +of course if you give him xon to XK he + + align:start position:0% +of course if you give him xon to XK he + + + align:start position:0% +of course if you give him xon to XK he +need to read his input his run times + + align:start position:0% +need to read his input his run times + + + align:start position:0% +need to read his input his run times +grow K but if you can kind of generate + + align:start position:0% +grow K but if you can kind of generate + + + align:start position:0% +grow K but if you can kind of generate +in succinct way then he doesn't need to + + align:start position:0% +in succinct way then he doesn't need to + + + align:start position:0% +in succinct way then he doesn't need to +grow grow with + + align:start position:0% +grow grow with + + + align:start position:0% +grow grow with +K okay so the you should another way to + + align:start position:0% +K okay so the you should another way to + + + align:start position:0% +K okay so the you should another way to +think about it you can think of x i as + + align:start position:0% +think about it you can think of x i as + + + align:start position:0% +think about it you can think of x i as +like M comma + + align:start position:0% +like M comma + + + align:start position:0% +like M comma +I and the instance just says if you run + + align:start position:0% +I and the instance just says if you run + + + align:start position:0% +I and the instance just says if you run +M on i x i then XI in the language and + + align:start position:0% +M on i x i then XI in the language and + + + align:start position:0% +M on i x i then XI in the language and +that's why it's called index language + + align:start position:0% +that's why it's called index language + + + align:start position:0% +that's why it's called index language +because it's like there's an index yeah + + align:start position:0% +because it's like there's an index yeah + + + align:start position:0% +because it's like there's an index yeah +so this means that there still like a + + align:start position:0% +so this means that there still like a + + + align:start position:0% +so this means that there still like a +depend in these R time right yeah yeah + + align:start position:0% +depend in these R time right yeah yeah + + + align:start position:0% +depend in these R time right yeah yeah +yeah there is a lock dependence 100% + + align:start position:0% +yeah there is a lock dependence 100% + + + align:start position:0% +yeah there is a lock dependence 100% +sorry yeah yeah it just means yeah + + align:start position:0% +sorry yeah yeah it just means yeah + + + align:start position:0% +sorry yeah yeah it just means yeah +exactly that runs into time uh log K + + align:start position:0% +exactly that runs into time uh log K + + + align:start position:0% +exactly that runs into time uh log K +actually yeah you have I here which is + + align:start position:0% +actually yeah you have I here which is + + + align:start position:0% +actually yeah you have I here which is +log K so there is a log K dependence + + align:start position:0% +log K so there is a log K dependence + + + align:start position:0% +log K so there is a log K dependence +yeah the CRS is sublinear in K as well + + align:start position:0% +yeah the CRS is sublinear in K as well + + + align:start position:0% +yeah the CRS is sublinear in K as well +is that true the length of the CRS in + + align:start position:0% +is that true the length of the CRS in + + + align:start position:0% +is that true the length of the CRS in +general you want it to be sublinear in K + + align:start position:0% +general you want it to be sublinear in K + + + align:start position:0% +general you want it to be sublinear in K +in the snar construction it's po okay + + align:start position:0% +in the snar construction it's po okay + + + align:start position:0% +in the snar construction it's po okay +but yes but when we'll talk about snar + + align:start position:0% +but yes but when we'll talk about snar + + + align:start position:0% +but yes but when we'll talk about snar +so yeah in the the in the bar the bar + + align:start position:0% +so yeah in the the in the bar the bar + + + align:start position:0% +so yeah in the the in the bar the bar +construction we have the + + align:start position:0% +construction we have the + + + align:start position:0% +construction we have the +CRS MO most of our construction the SS + + align:start position:0% +CRS MO most of our construction the SS + + + align:start position:0% +CRS MO most of our construction the SS +is of size + + align:start position:0% +is of size + + + align:start position:0% +is of size +pology uh the one under lwe that Jing + + align:start position:0% +pology uh the one under lwe that Jing + + + align:start position:0% +pology uh the one under lwe that Jing +Jang showed is is of size + + align:start position:0% + + + + align:start position:0% + +poly so I know that if we have a bar + + align:start position:0% +poly so I know that if we have a bar + + + align:start position:0% +poly so I know that if we have a bar +that size these properties and function + + align:start position:0% +that size these properties and function + + + align:start position:0% +that size these properties and function +I guess you can always kind of like like + + align:start position:0% +I guess you can always kind of like like + + + align:start position:0% +I guess you can always kind of like like +add the property that you want here + + align:start position:0% +add the property that you want here + + + align:start position:0% +add the property that you want here +being able to extract a witness from the + + align:start position:0% +being able to extract a witness from the + + + align:start position:0% +being able to extract a witness from the +group itself is there a world like do we + + align:start position:0% +group itself is there a world like do we + + + align:start position:0% +group itself is there a world like do we +have any bars without the assumptions + + align:start position:0% +have any bars without the assumptions + + + align:start position:0% +have any bars without the assumptions +that we need for + + align:start position:0% +that we need for + + + align:start position:0% +that we need for +function you're asking is there a bar + + align:start position:0% +function you're asking is there a bar + + + align:start position:0% +function you're asking is there a bar +for which we we we don't know how to + + align:start position:0% +for which we we we don't know how to + + + align:start position:0% +for which we we we don't know how to +extract is that what you're asking okay + + align:start position:0% +extract is that what you're asking okay + + + align:start position:0% +extract is that what you're asking okay +okay so okay so let me you're asking a + + align:start position:0% +okay so okay so let me you're asking a + + + align:start position:0% +okay so okay so let me you're asking a +great question let me kind of uh + + align:start position:0% +great question let me kind of uh + + + align:start position:0% +great question let me kind of uh +uh okay so when we said when I when the + + align:start position:0% +uh okay so when we said when I when the + + + align:start position:0% +uh okay so when we said when I when the +soundness condition just says that a + + align:start position:0% +soundness condition just says that a + + + align:start position:0% +soundness condition just says that a +cheating prover cannot uh you know cheat + + align:start position:0% +cheating prover cannot uh you know cheat + + + align:start position:0% +cheating prover cannot uh you know cheat +cannot generate X1 up to XK that one of + + align:start position:0% +cannot generate X1 up to XK that one of + + + align:start position:0% +cannot generate X1 up to XK that one of +them the I is not in the language and + + align:start position:0% +them the I is not in the language and + + + align:start position:0% +them the I is not in the language and +yet convinced + + align:start position:0% +yet convinced + + + align:start position:0% +yet convinced +often time also in our snar in our snar + + align:start position:0% +often time also in our snar in our snar + + + align:start position:0% +often time also in our snar in our snar +construction we want something stronger + + align:start position:0% +construction we want something stronger + + + align:start position:0% +construction we want something stronger +what we want is that I can actually + + align:start position:0% +what we want is that I can actually + + + align:start position:0% +what we want is that I can actually +extract a + + align:start position:0% +extract a + + + align:start position:0% +extract a +witness from from this cheating prover + + align:start position:0% +witness from from this cheating prover + + + align:start position:0% +witness from from this cheating prover +so I want to say this cheating prover I + + align:start position:0% +so I want to say this cheating prover I + + + align:start position:0% +so I want to say this cheating prover I +can't extract all the + + align:start position:0% +can't extract all the + + + align:start position:0% +can't extract all the +witnesses but for some ey I can generate + + align:start position:0% +witnesses but for some ey I can generate + + + align:start position:0% +witnesses but for some ey I can generate +a CRS that looks like just standard CRS + + align:start position:0% +a CRS that looks like just standard CRS + + + align:start position:0% +a CRS that looks like just standard CRS +but I can kind of change the + + align:start position:0% +but I can kind of change the + + + align:start position:0% +but I can kind of change the +distribution a CRS to be such that using + + align:start position:0% +distribution a CRS to be such that using + + + align:start position:0% +distribution a CRS to be such that using +some trapo about the CRS I can actually + + align:start position:0% +some trapo about the CRS I can actually + + + align:start position:0% +some trapo about the CRS I can actually +extract from P star a witness for XI and + + align:start position:0% +extract from P star a witness for XI and + + + align:start position:0% +extract from P star a witness for XI and +once I extract a witness of course it + + align:start position:0% +once I extract a witness of course it + + + align:start position:0% +once I extract a witness of course it +has to be in the language I I argue not + + align:start position:0% +has to be in the language I I argue not + + + align:start position:0% +has to be in the language I I argue not +only it's in the language I can even + + align:start position:0% +only it's in the language I can even + + + align:start position:0% +only it's in the language I can even +find you know get a witness from him so + + align:start position:0% +find you know get a witness from him so + + + align:start position:0% +find you know get a witness from him so +that's called somewhere this is like + + align:start position:0% +that's called somewhere this is like + + + align:start position:0% +that's called somewhere this is like +somewh extractable bar now what Li was + + align:start position:0% +somewh extractable bar now what Li was + + + align:start position:0% +somewh extractable bar now what Li was +saying is that the bar that Jen Jong uh + + align:start position:0% +saying is that the bar that Jen Jong uh + + + align:start position:0% +saying is that the bar that Jen Jong uh +showed you last time was extra had the + + align:start position:0% +showed you last time was extra had the + + + align:start position:0% +showed you last time was extra had the +somewh extractable property okay was + + align:start position:0% +somewh extractable property okay was + + + align:start position:0% +somewh extractable property okay was +extractable actually let me tell you we + + align:start position:0% +extractable actually let me tell you we + + + align:start position:0% +extractable actually let me tell you we +also will need bar that are somewhere + + align:start position:0% +also will need bar that are somewhere + + + align:start position:0% +also will need bar that are somewhere +extractable I didn't write that here why + + align:start position:0% +extractable I didn't write that here why + + + align:start position:0% +extractable I didn't write that here why +didn't I write it here and this is where + + align:start position:0% +didn't I write it here and this is where + + + align:start position:0% +didn't I write it here and this is where +the exactly the answer is any bar we can + + align:start position:0% +the exactly the answer is any bar we can + + + align:start position:0% +the exactly the answer is any bar we can +make it somewhere extractable by just + + align:start position:0% +make it somewhere extractable by just + + + align:start position:0% +make it somewhere extractable by just +adding a hash so we can kind of up we + + align:start position:0% +adding a hash so we can kind of up we + + + align:start position:0% +adding a hash so we can kind of up we +don't need to worry about summer + + align:start position:0% +don't need to worry about summer + + + align:start position:0% +don't need to worry about summer +extractability of a bar because what we + + align:start position:0% +extractability of a bar because what we + + + align:start position:0% +extractability of a bar because what we +can always do is add put a hash of all + + align:start position:0% +can always do is add put a hash of all + + + align:start position:0% +can always do is add put a hash of all +the witnesses a some if you have some + + align:start position:0% +the witnesses a some if you have some + + + align:start position:0% +the witnesses a some if you have some +extractable hash if you have a somewh + + align:start position:0% +extractable hash if you have a somewh + + + align:start position:0% +extractable hash if you have a somewh +extractable hash you can tell the + + align:start position:0% +extractable hash you can tell the + + + align:start position:0% +extractable hash you can tell the +verifier put a somewh extractable hash + + align:start position:0% +verifier put a somewh extractable hash + + + align:start position:0% +verifier put a somewh extractable hash +of all your Witnesses so take witness + + align:start position:0% +of all your Witnesses so take witness + + + align:start position:0% +of all your Witnesses so take witness +one witness two witness three up to + + align:start position:0% +one witness two witness three up to + + + align:start position:0% +one witness two witness three up to +witness K hash them and in the analysis + + align:start position:0% +witness K hash them and in the analysis + + + align:start position:0% +witness K hash them and in the analysis +just jumping ahead we're going to be + + align:start position:0% +just jumping ahead we're going to be + + + align:start position:0% +just jumping ahead we're going to be +extractable on all the locations + + align:start position:0% +extractable on all the locations + + + align:start position:0% +extractable on all the locations +corresponding to witness I and now we're + + align:start position:0% +corresponding to witness I and now we're + + + align:start position:0% +corresponding to witness I and now we're +going to tell him we're going to say + + align:start position:0% +going to tell him we're going to say + + + align:start position:0% +going to tell him we're going to say +give me a bar the bar is not for the + + align:start position:0% +give me a bar the bar is not for the + + + align:start position:0% +give me a bar the bar is not for the +original language L the bar says + + align:start position:0% +original language L the bar says + + + align:start position:0% +original language L the bar says +the bar that X eyes in the language now + + align:start position:0% +the bar that X eyes in the language now + + + align:start position:0% +the bar that X eyes in the language now +says there is an opening for the hash + + align:start position:0% +says there is an opening for the hash + + + align:start position:0% +says there is an opening for the hash +value that in the locations conf find to + + align:start position:0% +value that in the locations conf find to + + + align:start position:0% +value that in the locations conf find to +Wi if you opened you would get a valid + + align:start position:0% +Wi if you opened you would get a valid + + + align:start position:0% +Wi if you opened you would get a valid +witness bar that language so instead of + + align:start position:0% +witness bar that language so instead of + + + align:start position:0% +witness bar that language so instead of +barging the original language bark a + + align:start position:0% +barging the original language bark a + + + align:start position:0% +barging the original language bark a +little bit kind of upgraded language + + align:start position:0% +little bit kind of upgraded language + + + align:start position:0% +little bit kind of upgraded language +that again says there's a so the + + align:start position:0% +that again says there's a so the + + + align:start position:0% +that again says there's a so the +verifier will give you a hash of all the + + align:start position:0% +verifier will give you a hash of all the + + + align:start position:0% +verifier will give you a hash of all the +witnesses and he will prove for every + + align:start position:0% +witnesses and he will prove for every + + + align:start position:0% +witnesses and he will prove for every +eye he won't won't prove just XIs in the + + align:start position:0% +eye he won't won't prove just XIs in the + + + align:start position:0% +eye he won't won't prove just XIs in the +language he's going to prove for every + + align:start position:0% +language he's going to prove for every + + + align:start position:0% +language he's going to prove for every +eye I have openings corresponding to + + align:start position:0% +eye I have openings corresponding to + + + align:start position:0% +eye I have openings corresponding to +witness eye so that the a the openings + + align:start position:0% +witness eye so that the a the openings + + + align:start position:0% +witness eye so that the a the openings +are valid and B wi is in the is in the + + align:start position:0% +are valid and B wi is in the is in the + + + align:start position:0% +are valid and B wi is in the is in the +language L that's the bar he's going to + + align:start position:0% +language L that's the bar he's going to + + + align:start position:0% +language L that's the bar he's going to +give you and now the fact that you're in + + align:start position:0% +give you and now the fact that you're in + + + align:start position:0% +give you and now the fact that you're in +the + + align:start position:0% +the + + + align:start position:0% +the +language means that it must be that if + + align:start position:0% +language means that it must be that if + + + align:start position:0% +language means that it must be that if +you take the trap door and look into it + + align:start position:0% +you take the trap door and look into it + + + align:start position:0% +you take the trap door and look into it +it must be by by + + align:start position:0% +it must be by by + + + align:start position:0% +it must be by by +soundless must be that's what's sitting + + align:start position:0% +soundless must be that's what's sitting + + + align:start position:0% +soundless must be that's what's sitting +there because you're binding if if + + align:start position:0% +there because you're binding if if + + + align:start position:0% +there because you're binding if if +you're going to be binding on that part + + align:start position:0% +you're going to be binding on that part + + + align:start position:0% +you're going to be binding on that part +you know that what's sitting there must + + align:start position:0% +you know that what's sitting there must + + + align:start position:0% +you know that what's sitting there must +be the correct + + align:start position:0% +be the correct + + + align:start position:0% +be the correct +witness so that's uh that's kind of uh + + align:start position:0% +witness so that's uh that's kind of uh + + + align:start position:0% +witness so that's uh that's kind of uh +why why actually we don't need to + + align:start position:0% +why why actually we don't need to + + + align:start position:0% +why why actually we don't need to +construct bars with with extractability + + align:start position:0% +construct bars with with extractability + + + align:start position:0% +construct bars with with extractability +we can always attach uh uh some + + align:start position:0% +we can always attach uh uh some + + + align:start position:0% +we can always attach uh uh some +constructible hash to them yeah I guess + + align:start position:0% +constructible hash to them yeah I guess + + + align:start position:0% +constructible hash to them yeah I guess +actually Wonder something assumptions do + + align:start position:0% +actually Wonder something assumptions do + + + align:start position:0% +actually Wonder something assumptions do +we have any constructions of bars from + + align:start position:0% +we have any constructions of bars from + + + align:start position:0% +we have any constructions of bars from +assumptions weaker than those needed to + + align:start position:0% +assumptions weaker than those needed to + + + align:start position:0% +assumptions weaker than those needed to +construct which would make it I guess + + align:start position:0% +construct which would make it I guess + + + align:start position:0% +construct which would make it I guess +interesting I see what you're saying I + + align:start position:0% +interesting I see what you're saying I + + + align:start position:0% +interesting I see what you're saying I +see uh um I don't think not that I yeah + + align:start position:0% +see uh um I don't think not that I yeah + + + align:start position:0% +see uh um I don't think not that I yeah +I don't think so I don't think + + align:start position:0% + + + + align:start position:0% + +so yeah I don't know how to construct a + + align:start position:0% +so yeah I don't know how to construct a + + + align:start position:0% +so yeah I don't know how to construct a +bar from an assumption for which I don't + + align:start position:0% +bar from an assumption for which I don't + + + align:start position:0% +bar from an assumption for which I don't +know how to construct a some + + align:start position:0% +know how to construct a some + + + align:start position:0% +know how to construct a some +constructible hash + + align:start position:0% +constructible hash + + + align:start position:0% +constructible hash +yeah okay a any other + + align:start position:0% + + + + align:start position:0% + +questions okay so I want to get to the + + align:start position:0% +questions okay so I want to get to the + + + align:start position:0% +questions okay so I want to get to the +bar to the construction of the snar but + + align:start position:0% +bar to the construction of the snar but + + + align:start position:0% +bar to the construction of the snar but +before I do so I I I do want to spend a + + align:start position:0% +before I do so I I I do want to spend a + + + align:start position:0% +before I do so I I I do want to spend a +little more time on the summer + + align:start position:0% +little more time on the summer + + + align:start position:0% +little more time on the summer +extractable hash and say a little bit + + align:start position:0% +extractable hash and say a little bit + + + align:start position:0% +extractable hash and say a little bit +about the way we construct it because + + align:start position:0% +about the way we construct it because + + + align:start position:0% +about the way we construct it because +I'm just want to make sure that a + + align:start position:0% +I'm just want to make sure that a + + + align:start position:0% +I'm just want to make sure that a +a that you you you you didn't miss a + + align:start position:0% +a that you you you you didn't miss a + + + align:start position:0% +a that you you you you didn't miss a +part from last lecture that I think was + + align:start position:0% +part from last lecture that I think was + + + align:start position:0% +part from last lecture that I think was +a bit said too succinctly so the high + + align:start position:0% +a bit said too succinctly so the high + + + align:start position:0% +a bit said too succinctly so the high +level idea of how you construct a Sumer + + align:start position:0% +level idea of how you construct a Sumer + + + align:start position:0% +level idea of how you construct a Sumer +extractable hash is using uh fully + + align:start position:0% +extractable hash is using uh fully + + + align:start position:0% +extractable hash is using uh fully +homomorphic encryption okay so I don't + + align:start position:0% +homomorphic encryption okay so I don't + + + align:start position:0% +homomorphic encryption okay so I don't +want to get into uh uh I don't want to + + align:start position:0% +want to get into uh uh I don't want to + + + align:start position:0% +want to get into uh uh I don't want to +recall too much the definition but I'll + + align:start position:0% +recall too much the definition but I'll + + + align:start position:0% +recall too much the definition but I'll +I'll give you a high level so the basic + + align:start position:0% +I'll give you a high level so the basic + + + align:start position:0% +I'll give you a high level so the basic +idea which doesn't work okay let me + + align:start position:0% +idea which doesn't work okay let me + + + align:start position:0% +idea which doesn't work okay let me +first tell you the idea that doesn't + + align:start position:0% +first tell you the idea that doesn't + + + align:start position:0% +first tell you the idea that doesn't +work because that's very natural and I + + align:start position:0% +work because that's very natural and I + + + align:start position:0% +work because that's very natural and I +think maybe that's what you got from + + align:start position:0% +think maybe that's what you got from + + + align:start position:0% +think maybe that's what you got from +last lecture so the basic idea that + + align:start position:0% +last lecture so the basic idea that + + + align:start position:0% +last lecture so the basic idea that +doesn't work is to say that + + align:start position:0% + + + + align:start position:0% + +gen will just output + + align:start position:0% + + + + align:start position:0% + +encryption so it'll give you a public + + align:start position:0% +encryption so it'll give you a public + + + align:start position:0% +encryption so it'll give you a public +key an encryption of I with this public + + align:start position:0% + + + + align:start position:0% + +key and the trap door that's going to be + + align:start position:0% +key and the trap door that's going to be + + + align:start position:0% +key and the trap door that's going to be +the hash + + align:start position:0% +the hash + + + align:start position:0% +the hash +key and the trap door is going to be the + + align:start position:0% +key and the trap door is going to be the + + + align:start position:0% +key and the trap door is going to be the +secret + + align:start position:0% + + + + align:start position:0% + +key okay so I'm just the hash key is + + align:start position:0% +key okay so I'm just the hash key is + + + align:start position:0% +key okay so I'm just the hash key is +going to be an encryption of of the + + align:start position:0% +going to be an encryption of of the + + + align:start position:0% +going to be an encryption of of the +index + + align:start position:0% + + + + align:start position:0% + +now I want X1 to X n Let Me Assume for + + align:start position:0% +now I want X1 to X n Let Me Assume for + + + align:start position:0% +now I want X1 to X n Let Me Assume for +Simplicity that n + + align:start position:0% + + + + align:start position:0% + +suppose N is a power of two otherwise + + align:start position:0% +suppose N is a power of two otherwise + + + align:start position:0% +suppose N is a power of two otherwise +you know pad okay so let's say big n is + + align:start position:0% +you know pad okay so let's say big n is + + + align:start position:0% +you know pad okay so let's say big n is +a power of two so it's some two to the + + align:start position:0% +a power of two so it's some two to the + + + align:start position:0% +a power of two so it's some two to the +small n now here's what I'm going to do + + align:start position:0% +small n now here's what I'm going to do + + + align:start position:0% +small n now here's what I'm going to do +let me so when I say encryption of I + + align:start position:0% +let me so when I say encryption of I + + + align:start position:0% +let me so when I say encryption of I +let's think of it as bid by bit + + align:start position:0% +let's think of it as bid by bit + + + align:start position:0% +let's think of it as bid by bit +encryption so it's + + align:start position:0% +encryption so it's + + + align:start position:0% +encryption so it's +encryption of + + align:start position:0% +encryption of + + + align:start position:0% +encryption of +i1 up to encryption + + align:start position:0% +i1 up to encryption + + + align:start position:0% +i1 up to encryption +of I + + align:start position:0% + + + + align:start position:0% + +in okay and now the idea + + align:start position:0% + + + + align:start position:0% + +is what we'll do is for for each like + + align:start position:0% +is what we'll do is for for each like + + + align:start position:0% +is what we'll do is for for each like +pair so I'm going to do kind of a Merkle + + align:start position:0% +pair so I'm going to do kind of a Merkle + + + align:start position:0% +pair so I'm going to do kind of a Merkle +hash and for each pair I'm going to + + align:start position:0% +hash and for each pair I'm going to + + + align:start position:0% +hash and for each pair I'm going to +encrypt so I'm going to do this Merle + + align:start position:0% +encrypt so I'm going to do this Merle + + + align:start position:0% +encrypt so I'm going to do this Merle +hash where for each node I'm going to + + align:start position:0% +hash where for each node I'm going to + + + align:start position:0% +hash where for each node I'm going to +associate a cipher text and the output + + align:start position:0% +associate a cipher text and the output + + + align:start position:0% +associate a cipher text and the output +is going to be the cipher text of the + + align:start position:0% +is going to be the cipher text of the + + + align:start position:0% +is going to be the cipher text of the +root that's my hash value the hash Val + + align:start position:0% +root that's my hash value the hash Val + + + align:start position:0% +root that's my hash value the hash Val +is give be a cipher text of the root and + + align:start position:0% +is give be a cipher text of the root and + + + align:start position:0% +is give be a cipher text of the root and +this Cypher text going be a cyppher text + + align:start position:0% +this Cypher text going be a cyppher text + + + align:start position:0% +this Cypher text going be a cyppher text +it's encryption of + + align:start position:0% +it's encryption of + + + align:start position:0% +it's encryption of +XI okay how do I asso so of course I can + + align:start position:0% +XI okay how do I asso so of course I can + + + align:start position:0% +XI okay how do I asso so of course I can +comp encryption of x i this is a + + align:start position:0% +comp encryption of x i this is a + + + align:start position:0% +comp encryption of x i this is a +homomorphic encryption given X an + + align:start position:0% +homomorphic encryption given X an + + + align:start position:0% +homomorphic encryption given X an +encryption of I I can do computation + + align:start position:0% +encryption of I I can do computation + + + align:start position:0% +encryption of I I can do computation +under the hood so I can compute + + align:start position:0% +under the hood so I can compute + + + align:start position:0% +under the hood so I can compute +encryption of xabi okay so because this + + align:start position:0% +encryption of xabi okay so because this + + + align:start position:0% +encryption of xabi okay so because this +is a a fully homomorphic + + align:start position:0% +is a a fully homomorphic + + + align:start position:0% +is a a fully homomorphic +encryption + + align:start position:0% +encryption + + + align:start position:0% +encryption +given X and encryption of I + + align:start position:0% +given X and encryption of I + + + align:start position:0% +given X and encryption of I +I can compute encryption of + + align:start position:0% +I can compute encryption of + + + align:start position:0% +I can compute encryption of +xabi of course there's public keys I'm + + align:start position:0% +xabi of course there's public keys I'm + + + align:start position:0% +xabi of course there's public keys I'm +omitting them for sness of + + align:start position:0% +omitting them for sness of + + + align:start position:0% +omitting them for sness of +rotation okay this is because I can + + align:start position:0% +rotation okay this is because I can + + + align:start position:0% +rotation okay this is because I can +compute under the + + align:start position:0% +compute under the + + + align:start position:0% +compute under the +hood the value of the root is going to + + align:start position:0% +hood the value of the root is going to + + + align:start position:0% +hood the value of the root is going to +be encryption of + + align:start position:0% +be encryption of + + + align:start position:0% +be encryption of +XI but what kind of encryption it's not + + align:start position:0% +XI but what kind of encryption it's not + + + align:start position:0% +XI but what kind of encryption it's not +any ENC so let me tell you how exactly + + align:start position:0% +any ENC so let me tell you how exactly + + + align:start position:0% +any ENC so let me tell you how exactly +how I compute this encryption so the + + align:start position:0% +how I compute this encryption so the + + + align:start position:0% +how I compute this encryption so the +idea would be so and and not only that + + align:start position:0% +idea would be so and and not only that + + + align:start position:0% +idea would be so and and not only that +how do I open + + align:start position:0% +how do I open + + + align:start position:0% +how do I open +okay I want to do local opening so the + + align:start position:0% +okay I want to do local opening so the + + + align:start position:0% +okay I want to do local opening so the +the way I'm going to do it is as follows + + align:start position:0% +the way I'm going to do it is as follows + + + align:start position:0% +the way I'm going to do it is as follows +for each for each pair I'm going to + + align:start position:0% +for each for each pair I'm going to + + + align:start position:0% +for each for each pair I'm going to +encrypt only one of them I'm going to + + align:start position:0% +encrypt only one of them I'm going to + + + align:start position:0% +encrypt only one of them I'm going to +either put here encryption of X1 or + + align:start position:0% +either put here encryption of X1 or + + + align:start position:0% +either put here encryption of X1 or +encryption of X2 which one depending on + + align:start position:0% +encryption of X2 which one depending on + + + align:start position:0% +encryption of X2 which one depending on +i1 so let's start with i1 if i1 is zero + + align:start position:0% +i1 so let's start with i1 if i1 is zero + + + align:start position:0% +i1 so let's start with i1 if i1 is zero +I'm gonna so I'm I'm GNA let's say + + align:start position:0% +I'm gonna so I'm I'm GNA let's say + + + align:start position:0% +I'm gonna so I'm I'm GNA let's say +choose X1 if i1 is one I'm going to + + align:start position:0% +choose X1 if i1 is one I'm going to + + + align:start position:0% +choose X1 if i1 is one I'm going to +choose X2 it's I'm gonna choose even + + align:start position:0% +choose X2 it's I'm gonna choose even + + + align:start position:0% +choose X2 it's I'm gonna choose even +other so that the output will be the + + align:start position:0% +other so that the output will be the + + + align:start position:0% +other so that the output will be the +correct one uh okay so I'm gonna the the + + align:start position:0% +correct one uh okay so I'm gonna the the + + + align:start position:0% +correct one uh okay so I'm gonna the the +i1 depending on encryption of i1 that's + + align:start position:0% +i1 depending on encryption of i1 that's + + + align:start position:0% +i1 depending on encryption of i1 that's +going to tell me which one to put here + + align:start position:0% +going to tell me which one to put here + + + align:start position:0% +going to tell me which one to put here +zero I put all the + + align:start position:0% +zero I put all the + + + align:start position:0% +zero I put all the +left like the left children or one I put + + align:start position:0% +left like the left children or one I put + + + align:start position:0% +left like the left children or one I put +the right + + align:start position:0% +the right + + + align:start position:0% +the right +children and then I do the exact same + + align:start position:0% +children and then I do the exact same + + + align:start position:0% +children and then I do the exact same +thing given + + align:start position:0% +thing given + + + align:start position:0% +thing given +these whether I choose the left or right + + align:start position:0% +these whether I choose the left or right + + + align:start position:0% +these whether I choose the left or right +depends on encryption of I2 if I2 is + + align:start position:0% +depends on encryption of I2 if I2 is + + + align:start position:0% +depends on encryption of I2 if I2 is +zero I choose the left if I2 is one I + + align:start position:0% +zero I choose the left if I2 is one I + + + align:start position:0% +zero I choose the left if I2 is one I +choose the right and so on so forth + + align:start position:0% +choose the right and so on so forth + + + align:start position:0% +choose the right and so on so forth +that's the idea + + align:start position:0% + + + + align:start position:0% + +it's it's like an OT it's really like an + + align:start position:0% +it's it's like an OT it's really like an + + + align:start position:0% +it's it's like an OT it's really like an +OT exactly exact I didn't Define what OT + + align:start position:0% +OT exactly exact I didn't Define what OT + + + align:start position:0% +OT exactly exact I didn't Define what OT +is but it's exactly like an + + align:start position:0% +is but it's exactly like an + + + align:start position:0% +is but it's exactly like an +OT okay this does not + + align:start position:0% + + + + align:start position:0% + +work okay it it almost works but it does + + align:start position:0% +work okay it it almost works but it does + + + align:start position:0% +work okay it it almost works but it does +not work so let me tell you why it seems + + align:start position:0% +not work so let me tell you why it seems + + + align:start position:0% +not work so let me tell you why it seems +like it should work and then I just want + + align:start position:0% +like it should work and then I just want + + + align:start position:0% +like it should work and then I just want +to mention the uh the um the the a the + + align:start position:0% +to mention the uh the um the the a the + + + align:start position:0% +to mention the uh the um the the a the +subtlety here so the reason it you so + + align:start position:0% +subtlety here so the reason it you so + + + align:start position:0% +subtlety here so the reason it you so +okay so first how do you generate local + + align:start position:0% +okay so first how do you generate local + + + align:start position:0% +okay so first how do you generate local +opening well you check so if you want to + + align:start position:0% +opening well you check so if you want to + + + align:start position:0% +opening well you check so if you want to +open XI I I'll tell you okay give me X1 + + align:start position:0% +open XI I I'll tell you okay give me X1 + + + align:start position:0% +open XI I I'll tell you okay give me X1 +and X2 so I can check that this is + + align:start position:0% +and X2 so I can check that this is + + + align:start position:0% +and X2 so I can check that this is +corrected and then give me the hash the + + align:start position:0% +corrected and then give me the hash the + + + align:start position:0% +corrected and then give me the hash the +cipher text here and I can check that + + align:start position:0% +cipher text here and I can check that + + + align:start position:0% +cipher text here and I can check that +this is correct because each each Cipher + + align:start position:0% +this is correct because each each Cipher + + + align:start position:0% +this is correct because each each Cipher +text is some f valuation that depends on + + align:start position:0% +text is some f valuation that depends on + + + align:start position:0% +text is some f valuation that depends on +the two children and on the the hash key + + align:start position:0% +the two children and on the the hash key + + + align:start position:0% +the two children and on the the hash key +which is encryption so in in layer J it + + align:start position:0% +which is encryption so in in layer J it + + + align:start position:0% +which is encryption so in in layer J it +depends on the two children and + + align:start position:0% +depends on the two children and + + + align:start position:0% +depends on the two children and +encryption of + + align:start position:0% +encryption of + + + align:start position:0% +encryption of +IG okay each time the the the the + + align:start position:0% +IG okay each time the the the the + + + align:start position:0% +IG okay each time the the the the +node the the cipher text corresponding + + align:start position:0% +node the the cipher text corresponding + + + align:start position:0% +node the the cipher text corresponding +to some node is a deterministic function + + align:start position:0% +to some node is a deterministic function + + + align:start position:0% +to some node is a deterministic function +of the cipher text corresponding to the + + align:start position:0% +of the cipher text corresponding to the + + + align:start position:0% +of the cipher text corresponding to the +children and the hash key corresponding + + align:start position:0% +children and the hash key corresponding + + + align:start position:0% +children and the hash key corresponding +to that level so encryption of let's say + + align:start position:0% +to that level so encryption of let's say + + + align:start position:0% +to that level so encryption of let's say +JJ okay cu because remember if if I'm + + align:start position:0% +JJ okay cu because remember if if I'm + + + align:start position:0% +JJ okay cu because remember if if I'm +let's say in level two I have here + + align:start position:0% +let's say in level two I have here + + + align:start position:0% +let's say in level two I have here +Cipher text I don't know one and Cipher + + align:start position:0% +Cipher text I don't know one and Cipher + + + align:start position:0% +Cipher text I don't know one and Cipher +text two then I do + + align:start position:0% +text two then I do + + + align:start position:0% +text two then I do +U the way I compute the the parent uh + + align:start position:0% +U the way I compute the the parent uh + + + align:start position:0% +U the way I compute the the parent uh +Cipher text is just a homomorphic + + align:start position:0% +Cipher text is just a homomorphic + + + align:start position:0% +Cipher text is just a homomorphic +evaluation that takes if I uh if I to is + + align:start position:0% +evaluation that takes if I uh if I to is + + + align:start position:0% +evaluation that takes if I uh if I to is +zero it it takes cyppher text two if I + + align:start position:0% +zero it it takes cyppher text two if I + + + align:start position:0% +zero it it takes cyppher text two if I +two is one it takes sorry c one + + align:start position:0% +two is one it takes sorry c one + + + align:start position:0% +two is one it takes sorry c one +otherwise t i verx 2 okay so this is + + align:start position:0% +otherwise t i verx 2 okay so this is + + + align:start position:0% +otherwise t i verx 2 okay so this is +really just a deterministic homomorphic + + align:start position:0% +really just a deterministic homomorphic + + + align:start position:0% +really just a deterministic homomorphic +evaluation and so that's how I open I + + align:start position:0% +evaluation and so that's how I open I + + + align:start position:0% +evaluation and so that's how I open I +just open all the relevant CER Tex and + + align:start position:0% +just open all the relevant CER Tex and + + + align:start position:0% +just open all the relevant CER Tex and +the verifier will check that the + + align:start position:0% +the verifier will check that the + + + align:start position:0% +the verifier will check that the +homomorphic evaluation was done + + align:start position:0% +homomorphic evaluation was done + + + align:start position:0% +homomorphic evaluation was done +correctly so you can local opening you + + align:start position:0% +correctly so you can local opening you + + + align:start position:0% +correctly so you can local opening you +can do local opening but it's not + + align:start position:0% +can do local opening but it's not + + + align:start position:0% +can do local opening but it's not +binding or I don't know how to prove + + align:start position:0% +binding or I don't know how to prove + + + align:start position:0% +binding or I don't know how to prove +that it's binding is the problem okay + + align:start position:0% +that it's binding is the problem okay + + + align:start position:0% +that it's binding is the problem okay +and probably you can find a weird FHA + + align:start position:0% +and probably you can find a weird FHA + + + align:start position:0% +and probably you can find a weird FHA +for which it's not binding I don't know + + align:start position:0% +for which it's not binding I don't know + + + align:start position:0% +for which it's not binding I don't know +maybe for natural constructions it is + + align:start position:0% +maybe for natural constructions it is + + + align:start position:0% +maybe for natural constructions it is +binding I don't know I don't know how to + + align:start position:0% +binding I don't know I don't know how to + + + align:start position:0% +binding I don't know I don't know how to +prove it + + align:start position:0% +prove it + + + align:start position:0% +prove it +but there's a problem with binding and + + align:start position:0% +but there's a problem with binding and + + + align:start position:0% +but there's a problem with binding and +the problem with binding is that a + + align:start position:0% +the problem with binding is that a + + + align:start position:0% +the problem with binding is that a +cheating so it seems like it should be + + align:start position:0% +cheating so it seems like it should be + + + align:start position:0% +cheating so it seems like it should be +binding because look here is sitting + + align:start position:0% +binding because look here is sitting + + + align:start position:0% +binding because look here is sitting +encryption of + + align:start position:0% +encryption of + + + align:start position:0% +encryption of +XI but the thing is the reason why it's + + align:start position:0% +XI but the thing is the reason why it's + + + align:start position:0% +XI but the thing is the reason why it's +not binding is because a + + align:start position:0% +not binding is because a + + + align:start position:0% +not binding is because a +malicious + + align:start position:0% +malicious + + + align:start position:0% +malicious +ah a malicious + + align:start position:0% +ah a malicious + + + align:start position:0% +ah a malicious +adversary he may give Cipher Texs that + + align:start position:0% +adversary he may give Cipher Texs that + + + align:start position:0% +adversary he may give Cipher Texs that +are are garbage are completely garbage + + align:start position:0% +are are garbage are completely garbage + + + align:start position:0% +are are garbage are completely garbage +they don't actually they're not legal + + align:start position:0% +they don't actually they're not legal + + + align:start position:0% +they don't actually they're not legal +Cipher texts and and he if he gives + + align:start position:0% +Cipher texts and and he if he gives + + + align:start position:0% +Cipher texts and and he if he gives +Cypher Texs that are garbage I don't + + align:start position:0% +Cypher Texs that are garbage I don't + + + align:start position:0% +Cypher Texs that are garbage I don't +know + + align:start position:0% +know + + + align:start position:0% +know +why why would there be binding so I mean + + align:start position:0% +why why would there be binding so I mean + + + align:start position:0% +why why would there be binding so I mean +maybe extract doesn't work okay here's + + align:start position:0% +maybe extract doesn't work okay here's + + + align:start position:0% +maybe extract doesn't work okay here's +me I'm a malicious person I nothing ex + + align:start position:0% +me I'm a malicious person I nothing ex + + + align:start position:0% +me I'm a malicious person I nothing ex +no you can't extract anything I just + + align:start position:0% +no you can't extract anything I just + + + align:start position:0% +no you can't extract anything I just +want to ruin the binding my whole goal + + align:start position:0% +want to ruin the binding my whole goal + + + align:start position:0% +want to ruin the binding my whole goal +is + + align:start position:0% +is + + + align:start position:0% +is +to kind of Ruin binding here okay I'm + + align:start position:0% +to kind of Ruin binding here okay I'm + + + align:start position:0% +to kind of Ruin binding here okay I'm +going to give you V that doesn't encrypt + + align:start position:0% +going to give you V that doesn't encrypt + + + align:start position:0% +going to give you V that doesn't encrypt +anything it's a junk V and I'm going to + + align:start position:0% +anything it's a junk V and I'm going to + + + align:start position:0% +anything it's a junk V and I'm going to +open it in two different ways Maybe + + align:start position:0% +open it in two different ways Maybe + + + align:start position:0% +open it in two different ways Maybe +maybe I can generate a v like it's I + + align:start position:0% +maybe I can generate a v like it's I + + + align:start position:0% +maybe I can generate a v like it's I +call it Cypher text but it's just a + + align:start position:0% +call it Cypher text but it's just a + + + align:start position:0% +call it Cypher text but it's just a +bunch of bits that have no meaning + + align:start position:0% +bunch of bits that have no meaning + + + align:start position:0% +bunch of bits that have no meaning +cannot be decrypted at all and maybe I + + align:start position:0% +cannot be decrypted at all and maybe I + + + align:start position:0% +cannot be decrypted at all and maybe I +can somehow generate valid + + align:start position:0% +can somehow generate valid + + + align:start position:0% +can somehow generate valid +openings so and I we don't know how to + + align:start position:0% +openings so and I we don't know how to + + + align:start position:0% +openings so and I we don't know how to +argue that you cannot do that so in + + align:start position:0% +argue that you cannot do that so in + + + align:start position:0% +argue that you cannot do that so in +order to actually get soundness I need + + align:start position:0% +order to actually get soundness I need + + + align:start position:0% +order to actually get soundness I need +to make sure that the things are well + + align:start position:0% +to make sure that the things are well + + + align:start position:0% +to make sure that the things are well +formed that these are actually valid + + align:start position:0% +formed that these are actually valid + + + align:start position:0% +formed that these are actually valid +Cipher text or what I open to is a valid + + align:start position:0% +Cipher text or what I open to is a valid + + + align:start position:0% +Cipher text or what I open to is a valid +Cipher text + + align:start position:0% +Cipher text + + + align:start position:0% +Cipher text +and the way we get this is by making + + align:start position:0% +and the way we get this is by making + + + align:start position:0% +and the way we get this is by making +this a little more + + align:start position:0% +this a little more + + + align:start position:0% +this a little more +cumbersome so the way we get this is we + + align:start position:0% +cumbersome so the way we get this is we + + + align:start position:0% +cumbersome so the way we get this is we +actually don't use one public key we use + + align:start position:0% +actually don't use one public key we use + + + align:start position:0% +actually don't use one public key we use +small n public keys so for each layer + + align:start position:0% +small n public keys so for each layer + + + align:start position:0% +small n public keys so for each layer +we'll use a different public key and + + align:start position:0% +we'll use a different public key and + + + align:start position:0% +we'll use a different public key and +what we encrypt so what okay so what we + + align:start position:0% +what we encrypt so what okay so what we + + + align:start position:0% +what we encrypt so what okay so what we +do is we + + align:start position:0% +do is we + + + align:start position:0% +do is we +have public key + + align:start position:0% +have public key + + + align:start position:0% +have public key +j for J goes from one to n okay so we + + align:start position:0% +j for J goes from one to n okay so we + + + align:start position:0% +j for J goes from one to n okay so we +have n public keys and with public key + + align:start position:0% +have n public keys and with public key + + + align:start position:0% +have n public keys and with public key +j we encrypt i j but also so the you one + + align:start position:0% +j we encrypt i j but also so the you one + + + align:start position:0% +j we encrypt i j but also so the you one +I has I want up to i n we encrypt i j + + align:start position:0% +I has I want up to i n we encrypt i j + + + align:start position:0% +I has I want up to i n we encrypt i j +but we also + + align:start position:0% +but we also + + + align:start position:0% +but we also +encrypt skj minus one we I want to have + + align:start position:0% +encrypt skj minus one we I want to have + + + align:start position:0% +encrypt skj minus one we I want to have +the decryption it's important me to have + + align:start position:0% +the decryption it's important me to have + + + align:start position:0% +the decryption it's important me to have +the decryption + + align:start position:0% +the decryption + + + align:start position:0% +the decryption +key now okay so the the the bit the + + align:start position:0% +key now okay so the the the bit the + + + align:start position:0% +key now okay so the the the bit the +important bit is that homomorphic + + align:start position:0% +important bit is that homomorphic + + + align:start position:0% +important bit is that homomorphic +evaluation I'm doing here I need to know + + align:start position:0% +evaluation I'm doing here I need to know + + + align:start position:0% +evaluation I'm doing here I need to know +the secret key because I'm not just + + align:start position:0% +the secret key because I'm not just + + + align:start position:0% +the secret key because I'm not just +gonna say before I said what's going on + + align:start position:0% +gonna say before I said what's going on + + + align:start position:0% +gonna say before I said what's going on +underneath under the hood I'm saying + + align:start position:0% +underneath under the hood I'm saying + + + align:start position:0% +underneath under the hood I'm saying +look I have I one I have two Cipher + + align:start position:0% +look I have I one I have two Cipher + + + align:start position:0% +look I have I one I have two Cipher +texts give me one of them no no no no + + align:start position:0% +texts give me one of them no no no no + + + align:start position:0% +texts give me one of them no no no no +what I want to do is to say the + + align:start position:0% +what I want to do is to say the + + + align:start position:0% +what I want to do is to say the +following under the hood decrypt + + align:start position:0% +following under the hood decrypt + + + align:start position:0% +following under the hood decrypt +this decrypt this + + align:start position:0% + + + + align:start position:0% + +and give me only the relevant one so + + align:start position:0% +and give me only the relevant one so + + + align:start position:0% +and give me only the relevant one so +that even if this does not + + align:start position:0% +that even if this does not + + + align:start position:0% +that even if this does not +decrypt so okay so here's the point + + align:start position:0% +decrypt so okay so here's the point + + + align:start position:0% +decrypt so okay so here's the point +let's say I want to open to + + align:start position:0% +let's say I want to open to + + + align:start position:0% +let's say I want to open to +X2 okay so okay he gives me X1 these are + + align:start position:0% +X2 okay so okay he gives me X1 these are + + + align:start position:0% +X2 okay so okay he gives me X1 these are +valid so this is valid good but + + align:start position:0% +valid so this is valid good but + + + align:start position:0% +valid so this is valid good but +now Cypher Tex 2 can be completely not + + align:start position:0% +now Cypher Tex 2 can be completely not + + + align:start position:0% +now Cypher Tex 2 can be completely not +valid cuz when he opens he gives me + + align:start position:0% +valid cuz when he opens he gives me + + + align:start position:0% +valid cuz when he opens he gives me +Cypher Tex one with these two so I know + + align:start position:0% +Cypher Tex one with these two so I know + + + align:start position:0% +Cypher Tex one with these two so I know +this was valid because this is + + align:start position:0% +this was valid because this is + + + align:start position:0% +this was valid because this is +computation and then they give me Cypher + + align:start position:0% +computation and then they give me Cypher + + + align:start position:0% +computation and then they give me Cypher +Tex 2 and I do this evaluation then they + + align:start position:0% +Tex 2 and I do this evaluation then they + + + align:start position:0% +Tex 2 and I do this evaluation then they +G me so the The Sibling Cipher Tex that + + align:start position:0% +G me so the The Sibling Cipher Tex that + + + align:start position:0% +G me so the The Sibling Cipher Tex that +he gives me they may not be valid I want + + align:start position:0% +he gives me they may not be valid I want + + + align:start position:0% +he gives me they may not be valid I want +to Ure even if they're not valid even if + + align:start position:0% +to Ure even if they're not valid even if + + + align:start position:0% +to Ure even if they're not valid even if +they're not valid this is going to be + + align:start position:0% +they're not valid this is going to be + + + align:start position:0% +they're not valid this is going to be +valid the openings are going to be valid + + align:start position:0% +valid the openings are going to be valid + + + align:start position:0% +valid the openings are going to be valid +kind of the on the path things are going + + align:start position:0% +kind of the on the path things are going + + + align:start position:0% +kind of the on the path things are going +to be valid even though the siblings + + align:start position:0% +to be valid even though the siblings + + + align:start position:0% +to be valid even though the siblings +that are given in order to just kind of + + align:start position:0% +that are given in order to just kind of + + + align:start position:0% +that are given in order to just kind of +do the verify the opening even if + + align:start position:0% +do the verify the opening even if + + + align:start position:0% +do the verify the opening even if +they're not valid the opening path will + + align:start position:0% +they're not valid the opening path will + + + align:start position:0% +they're not valid the opening path will +be kind of valid Cipher texts so why are + + align:start position:0% +be kind of valid Cipher texts so why are + + + align:start position:0% +be kind of valid Cipher texts so why are +they going to be valid because the way + + align:start position:0% +they going to be valid because the way + + + align:start position:0% +they going to be valid because the way +that what is so now let's what is the + + align:start position:0% +that what is so now let's what is the + + + align:start position:0% +that what is so now let's what is the +deterministic computation that's + + align:start position:0% +deterministic computation that's + + + align:start position:0% +deterministic computation that's +happening here the deter or the + + align:start position:0% +happening here the deter or the + + + align:start position:0% +happening here the deter or the +evaluation the the evaluated Cipher Tech + + align:start position:0% +evaluation the the evaluated Cipher Tech + + + align:start position:0% +evaluation the the evaluated Cipher Tech +the way we do the evaluation is the + + align:start position:0% +the way we do the evaluation is the + + + align:start position:0% +the way we do the evaluation is the +following I decrypt this and I decrypt + + align:start position:0% +following I decrypt this and I decrypt + + + align:start position:0% +following I decrypt this and I decrypt +this and then I take the decrypted value + + align:start position:0% +this and then I take the decrypted value + + + align:start position:0% +this and then I take the decrypted value +and I encrypted with the next public key + + align:start position:0% +and I encrypted with the next public key + + + align:start position:0% +and I encrypted with the next public key +so the point is even if this didn't + + align:start position:0% +so the point is even if this didn't + + + align:start position:0% +so the point is even if this didn't +decrypt maybe this didn't decrypt I + + align:start position:0% +decrypt maybe this didn't decrypt I + + + align:start position:0% +decrypt maybe this didn't decrypt I +don't + + align:start position:0% +don't + + + align:start position:0% +don't +care I'm this is still going to be + + align:start position:0% + + + + align:start position:0% + +valid okay so the point is even if the + + align:start position:0% +valid okay so the point is even if the + + + align:start position:0% +valid okay so the point is even if the +The Sibling Cipher texts that are given + + align:start position:0% +The Sibling Cipher texts that are given + + + align:start position:0% +The Sibling Cipher texts that are given +only for verifying the opening even if + + align:start position:0% +only for verifying the opening even if + + + align:start position:0% +only for verifying the opening even if +these sibling Cipher text are malale + + align:start position:0% +these sibling Cipher text are malale + + + align:start position:0% +these sibling Cipher text are malale +formed if you give me the open openings + + align:start position:0% +formed if you give me the open openings + + + align:start position:0% +formed if you give me the open openings +in the entire path I get the guarantee + + align:start position:0% +in the entire path I get the guarantee + + + align:start position:0% +in the entire path I get the guarantee +that on the path not on the siblings on + + align:start position:0% +that on the path not on the siblings on + + + align:start position:0% +that on the path not on the siblings on +the path things are well formed and I + + align:start position:0% +the path things are well formed and I + + + align:start position:0% +the path things are well formed and I +mean well formed cyer these are Cipher + + align:start position:0% +mean well formed cyer these are Cipher + + + align:start position:0% +mean well formed cyer these are Cipher +Texs that decrypt + + align:start position:0% +Texs that decrypt + + + align:start position:0% +Texs that decrypt +correctly and that's what I need for for + + align:start position:0% +correctly and that's what I need for for + + + align:start position:0% +correctly and that's what I need for for +the soundness so it's important to do + + align:start position:0% +the soundness so it's important to do + + + align:start position:0% +the soundness so it's important to do +the decryption this is really uh crucial + + align:start position:0% +the decryption this is really uh crucial + + + align:start position:0% +the decryption this is really uh crucial +okay you doing each I follow okay again + + align:start position:0% +okay you doing each I follow okay again + + + align:start position:0% +okay you doing each I follow okay again +what what am I doing on each note good + + align:start position:0% +what what am I doing on each note good + + + align:start position:0% +what what am I doing on each note good +good good so here's what I'm doing on + + align:start position:0% +good good so here's what I'm doing on + + + align:start position:0% +good good so here's what I'm doing on +each Noe H the evaluation function takes + + align:start position:0% +each Noe H the evaluation function takes + + + align:start position:0% +each Noe H the evaluation function takes +kind of i j + + align:start position:0% +kind of i j + + + align:start position:0% +kind of i j +secret key j minus one and two Cipher + + align:start position:0% +secret key j minus one and two Cipher + + + align:start position:0% +secret key j minus one and two Cipher +Tex Cipher Tex zero and Cipher Tex + + align:start position:0% +Tex Cipher Tex zero and Cipher Tex + + + align:start position:0% +Tex Cipher Tex zero and Cipher Tex +one and what it does is the following + + align:start position:0% +one and what it does is the following + + + align:start position:0% +one and what it does is the following +decrypt cyppher Tex zero so it + + align:start position:0% +decrypt cyppher Tex zero so it + + + align:start position:0% +decrypt cyppher Tex zero so it +decrypts with SK J minus one uh cyppher + + align:start position:0% +decrypts with SK J minus one uh cyppher + + + align:start position:0% +decrypts with SK J minus one uh cyppher +Tex Z cyppher text B for every B get get + + align:start position:0% +Tex Z cyppher text B for every B get get + + + align:start position:0% +Tex Z cyppher text B for every B get get +some uh bit I don't know a a alpha + + align:start position:0% +some uh bit I don't know a a alpha + + + align:start position:0% +some uh bit I don't know a a alpha +B and then it + + align:start position:0% + + + + align:start position:0% + +outputs one of them I know Alpha B Star + + align:start position:0% +outputs one of them I know Alpha B Star + + + align:start position:0% +outputs one of them I know Alpha B Star +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +i j so so it gets to bits and he he he + + align:start position:0% +i j so so it gets to bits and he he he + + + align:start position:0% +i j so so it gets to bits and he he he +chooses one of them which one depending + + align:start position:0% +chooses one of them which one depending + + + align:start position:0% +chooses one of them which one depending +on the IG you want so what you will get + + align:start position:0% +on the IG you want so what you will get + + + align:start position:0% +on the IG you want so what you will get +the point is what you will get is really + + align:start position:0% +the point is what you will get is really + + + align:start position:0% +the point is what you will get is really +an encryption so the point is let's + + align:start position:0% +an encryption so the point is let's + + + align:start position:0% +an encryption so the point is let's +say I do it under the hood this isn't a + + align:start position:0% +say I do it under the hood this isn't a + + + align:start position:0% +say I do it under the hood this isn't a +computation that is done under the hood + + align:start position:0% +computation that is done under the hood + + + align:start position:0% +computation that is done under the hood +yes so this is going to be encrypted in + + align:start position:0% +yes so this is going to be encrypted in + + + align:start position:0% +yes so this is going to be encrypted in +and in in a box but what I'm going to do + + align:start position:0% +and in in a box but what I'm going to do + + + align:start position:0% +and in in a box but what I'm going to do +Under the box is to say so these I have + + align:start position:0% +Under the box is to say so these I have + + + align:start position:0% +Under the box is to say so these I have +so sorry these two are i j and skj minus + + align:start position:0% +so sorry these two are i j and skj minus + + + align:start position:0% +so sorry these two are i j and skj minus +one are in a box and the computation + + align:start position:0% +one are in a box and the computation + + + align:start position:0% +one are in a box and the computation +that I'm doing inside the box as I'm + + align:start position:0% +that I'm doing inside the box as I'm + + + align:start position:0% +that I'm doing inside the box as I'm +saying I have these in a box I have + + align:start position:0% +saying I have these in a box I have + + + align:start position:0% +saying I have these in a box I have +these in the clear Inside the Box what I + + align:start position:0% +these in the clear Inside the Box what I + + + align:start position:0% +these in the clear Inside the Box what I +do is the following I say I have the + + align:start position:0% +do is the following I say I have the + + + align:start position:0% +do is the following I say I have the +secret key j minus one and these two + + align:start position:0% +secret key j minus one and these two + + + align:start position:0% +secret key j minus one and these two +Cipher texts let me decrypt both of them + + align:start position:0% +Cipher texts let me decrypt both of them + + + align:start position:0% +Cipher texts let me decrypt both of them +I'm going to get two bits Alpha zero and + + align:start position:0% +I'm going to get two bits Alpha zero and + + + align:start position:0% +I'm going to get two bits Alpha zero and +Alpha One now maybe one of them is bad + + align:start position:0% +Alpha One now maybe one of them is bad + + + align:start position:0% +Alpha One now maybe one of them is bad +so but so maybe one of them doesn't + + align:start position:0% +so but so maybe one of them doesn't + + + align:start position:0% +so but so maybe one of them doesn't +decrypt so the one that doesn't decrypt + + align:start position:0% +decrypt so the one that doesn't decrypt + + + align:start position:0% +decrypt so the one that doesn't decrypt +I'll put + + align:start position:0% +I'll put + + + align:start position:0% +I'll put +bot and then the output will be the + + align:start position:0% +bot and then the output will be the + + + align:start position:0% +bot and then the output will be the +relevant one that according if if it's + + align:start position:0% +relevant one that according if if it's + + + align:start position:0% +relevant one that according if if it's +zero I'm going to Output Alpha zero if + + align:start position:0% +zero I'm going to Output Alpha zero if + + + align:start position:0% +zero I'm going to Output Alpha zero if +it's one I'm going to Output Alpha One + + align:start position:0% +it's one I'm going to Output Alpha One + + + align:start position:0% +it's one I'm going to Output Alpha One +and now what I can argue is on the path + + align:start position:0% +and now what I can argue is on the path + + + align:start position:0% +and now what I can argue is on the path +itself everything has to be well formed + + align:start position:0% +itself everything has to be well formed + + + align:start position:0% +itself everything has to be well formed +so I'm actually going to get the the + + align:start position:0% +so I'm actually going to get the the + + + align:start position:0% +so I'm actually going to get the the +correct Cipher text and I can argue that + + align:start position:0% +correct Cipher text and I can argue that + + + align:start position:0% +correct Cipher text and I can argue that +by induction Okay so + + align:start position:0% +by induction Okay so + + + align:start position:0% +by induction Okay so +here of course this is well form because + + align:start position:0% +here of course this is well form because + + + align:start position:0% +here of course this is well form because +I this is just a deterministic + + align:start position:0% +I this is just a deterministic + + + align:start position:0% +I this is just a deterministic +computation that's done locally now the + + align:start position:0% +computation that's done locally now the + + + align:start position:0% +computation that's done locally now the +point is so let's say like I I want to + + align:start position:0% +point is so let's say like I I want to + + + align:start position:0% +point is so let's say like I I want to +Output I want to I'm binding an X1 this + + align:start position:0% +Output I want to I'm binding an X1 this + + + align:start position:0% +Output I want to I'm binding an X1 this +is X1 is what I want to open Okay so + + align:start position:0% +is X1 is what I want to open Okay so + + + align:start position:0% +is X1 is what I want to open Okay so +this must be well formed and now the + + align:start position:0% +this must be well formed and now the + + + align:start position:0% +this must be well formed and now the +point is even if this is not well + + align:start position:0% +point is even if this is not well + + + align:start position:0% +point is even if this is not well +formed what will I do under the hood I'm + + align:start position:0% +formed what will I do under the hood I'm + + + align:start position:0% +formed what will I do under the hood I'm +going to open this and open this this is + + align:start position:0% +going to open this and open this this is + + + align:start position:0% +going to open this and open this this is +going to be the correct value this is + + align:start position:0% +going to be the correct value this is + + + align:start position:0% +going to be the correct value this is +not going to be maybe the correct this + + align:start position:0% +not going to be maybe the correct this + + + align:start position:0% +not going to be maybe the correct this +may be bot but this is the one I choose + + align:start position:0% +may be bot but this is the one I choose + + + align:start position:0% +may be bot but this is the one I choose +and then I encrypt it so I have it here + + align:start position:0% +and then I encrypt it so I have it here + + + align:start position:0% +and then I encrypt it so I have it here +and then again this may be bad I'm going + + align:start position:0% +and then again this may be bad I'm going + + + align:start position:0% +and then again this may be bad I'm going +to decrypt it it may be bot but this is + + align:start position:0% +to decrypt it it may be bot but this is + + + align:start position:0% +to decrypt it it may be bot but this is +going to be good and this is the one I + + align:start position:0% +going to be good and this is the one I + + + align:start position:0% +going to be good and this is the one I +choose so one can argue kind of by + + align:start position:0% +choose so one can argue kind of by + + + align:start position:0% +choose so one can argue kind of by +induction that this is going to be inp x + + align:start position:0% +induction that this is going to be inp x + + + align:start position:0% +induction that this is going to be inp x +one this is going be inp everything in + + align:start position:0% +one this is going be inp everything in + + + align:start position:0% +one this is going be inp everything in +of X1 until the end so there's no way + + align:start position:0% +of X1 until the end so there's no way + + + align:start position:0% +of X1 until the end so there's no way +you can open two different ways you have + + align:start position:0% +you can open two different ways you have + + + align:start position:0% +you can open two different ways you have +to open to + + align:start position:0% +to open to + + + align:start position:0% +to open to +X1 and the verifier is also going to do + + align:start position:0% +X1 and the verifier is also going to do + + + align:start position:0% +X1 and the verifier is also going to do +the same computation to check exactly + + align:start position:0% +the same computation to check exactly + + + align:start position:0% +the same computation to check exactly +the verifier does the exact same + + align:start position:0% +the verifier does the exact same + + + align:start position:0% +the verifier does the exact same +computation to check yes + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +only right this is not opening a general + + align:start position:0% +only right this is not opening a general + + + align:start position:0% +only right this is not opening a general +good so this exactly this shows that the + + align:start position:0% +good so this exactly this shows that the + + + align:start position:0% +good so this exactly this shows that the +specific uh so this + + align:start position:0% +specific uh so this + + + align:start position:0% +specific uh so this +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% + + + + align:start position:0% + +uh okay this shows that the specific eye + + align:start position:0% +uh okay this shows that the specific eye + + + align:start position:0% +uh okay this shows that the specific eye +that's encrypted here so there's one the + + align:start position:0% +that's encrypted here so there's one the + + + align:start position:0% +that's encrypted here so there's one the +hash key is binding on one eye on + + align:start position:0% +hash key is binding on one eye on + + + align:start position:0% +hash key is binding on one eye on +specific eye the the eye on which you're + + align:start position:0% +specific eye the the eye on which you're + + + align:start position:0% +specific eye the the eye on which you're +binding you can only open in one way uh + + align:start position:0% +binding you can only open in one way uh + + + align:start position:0% +binding you can only open in one way uh +statistically and then by the index + + align:start position:0% +statistically and then by the index + + + align:start position:0% +statistically and then by the index +hiding it means that you can only for + + align:start position:0% +hiding it means that you can only for + + + align:start position:0% +hiding it means that you can only for +any J you can only open one way + + align:start position:0% +any J you can only open one way + + + align:start position:0% +any J you can only open one way +computationally because you can + + align:start position:0% +computationally because you can + + + align:start position:0% +computationally because you can +distinguish yeah you avoid this chain of + + align:start position:0% +distinguish yeah you avoid this chain of + + + align:start position:0% +distinguish yeah you avoid this chain of +keys if you happy to + + align:start position:0% +keys if you happy to + + + align:start position:0% +keys if you happy to +ENC good very good good good yes so you + + align:start position:0% +ENC good very good good good yes so you + + + align:start position:0% +ENC good very good good good yes so you +can avoid uh you can avoid avoid using + + align:start position:0% +can avoid uh you can avoid avoid using + + + align:start position:0% +can avoid uh you can avoid avoid using +many public Keys you can just use one + + align:start position:0% +many public Keys you can just use one + + + align:start position:0% +many public Keys you can just use one +public key encrypt the secret key and + + align:start position:0% +public key encrypt the secret key and + + + align:start position:0% +public key encrypt the secret key and +and rely on what's called circular + + align:start position:0% +and rely on what's called circular + + + align:start position:0% +and rely on what's called circular +security that's another option if you + + align:start position:0% +security that's another option if you + + + align:start position:0% +security that's another option if you +wish s doesn't want to do + + align:start position:0% +wish s doesn't want to do + + + align:start position:0% +wish s doesn't want to do +that but yes + + align:start position:0% +that but yes + + + align:start position:0% +that but yes +exactly exactly + + align:start position:0% +exactly exactly + + + align:start position:0% +exactly exactly +yeah you see get + + align:start position:0% +yeah you see get + + + align:start position:0% +yeah you see get +resistance you okay so yeah so you're + + align:start position:0% +resistance you okay so yeah so you're + + + align:start position:0% +resistance you okay so yeah so you're +asking will you get uh Collision like + + align:start position:0% +asking will you get uh Collision like + + + align:start position:0% +asking will you get uh Collision like +Collision resistance and the answer is + + align:start position:0% +Collision resistance and the answer is + + + align:start position:0% +Collision resistance and the answer is +yes + + align:start position:0% +yes + + + align:start position:0% +yes +because for the specific eye that you + + align:start position:0% +because for the specific eye that you + + + align:start position:0% +because for the specific eye that you +for the specific ey that kind of you en + + align:start position:0% +for the specific ey that kind of you en + + + align:start position:0% +for the specific ey that kind of you en +encrypted in the hash key you get uh + + align:start position:0% +encrypted in the hash key you get uh + + + align:start position:0% +encrypted in the hash key you get uh +binding kind of statistically okay + + align:start position:0% +binding kind of statistically okay + + + align:start position:0% +binding kind of statistically okay +there's no way you can open two + + align:start position:0% +there's no way you can open two + + + align:start position:0% +there's no way you can open two +different + + align:start position:0% +different + + + align:start position:0% +different +ways + + align:start position:0% +ways + + + align:start position:0% +ways +and what you have at the end is just the + + align:start position:0% +and what you have at the end is just the + + + align:start position:0% +and what you have at the end is just the +encryption of that Index right right so + + align:start position:0% +encryption of that Index right right so + + + align:start position:0% +encryption of that Index right right so +you're asking about a different J oh + + align:start position:0% +you're asking about a different J oh + + + align:start position:0% +you're asking about a different J oh +sorry no that you you have two x's that + + align:start position:0% +sorry no that you you have two x's that + + + align:start position:0% +sorry no that you you have two x's that +have the same uh + + align:start position:0% + + + + align:start position:0% + +index have the same that index and then + + align:start position:0% +index have the same that index and then + + + align:start position:0% +index have the same that index and then +but the are + + align:start position:0% +but the are + + + align:start position:0% +but the are +different you get a different outut of + + align:start position:0% +different you get a different outut of + + + align:start position:0% +different you get a different outut of +the if you take those two different X + + align:start position:0% +the if you take those two different X + + + align:start position:0% +the if you take those two different X +good good good okay so if you take two + + align:start position:0% +good good good okay so if you take two + + + align:start position:0% +good good good okay so if you take two +different X's for which let's say they + + align:start position:0% +different X's for which let's say they + + + align:start position:0% +different X's for which let's say they +have the same X1 and let's say the hash + + align:start position:0% +have the same X1 and let's say the hash + + + align:start position:0% +have the same X1 and let's say the hash +key is binding on location + + align:start position:0% +key is binding on location + + + align:start position:0% +key is binding on location +one the value would get if you if you + + align:start position:0% +one the value would get if you if you + + + align:start position:0% +one the value would get if you if you +hash them honestly will be actually very + + align:start position:0% +hash them honestly will be actually very + + + align:start position:0% +hash them honestly will be actually very +different + + align:start position:0% +different + + + align:start position:0% +different +but because you use different X's but so + + align:start position:0% +but because you use different X's but so + + + align:start position:0% +but because you use different X's but so +you'll get different values but if you + + align:start position:0% +you'll get different values but if you + + + align:start position:0% +you'll get different values but if you +decrypt these values correspond to a + + align:start position:0% +decrypt these values correspond to a + + + align:start position:0% +decrypt these values correspond to a +cyppher text as values they're going to + + align:start position:0% +cyppher text as values they're going to + + + align:start position:0% +cyppher text as values they're going to +look very different but if you decrypt + + align:start position:0% +look very different but if you decrypt + + + align:start position:0% +look very different but if you decrypt +you will get the same bit which is + + align:start position:0% +you will get the same bit which is + + + align:start position:0% +you will get the same bit which is +X1 yeah good okay so anyway if you if + + align:start position:0% +X1 yeah good okay so anyway if you if + + + align:start position:0% +X1 yeah good okay so anyway if you if +you didn't follow the exact construction + + align:start position:0% +you didn't follow the exact construction + + + align:start position:0% +you didn't follow the exact construction +it doesn't really matter I just wanted + + align:start position:0% +it doesn't really matter I just wanted + + + align:start position:0% +it doesn't really matter I just wanted +to make sure that uh uh you know this it + + align:start position:0% +to make sure that uh uh you know this it + + + align:start position:0% +to make sure that uh uh you know this it +was clear that you really needed to do + + align:start position:0% +was clear that you really needed to do + + + align:start position:0% +was clear that you really needed to do +this decryption uh yeah the reason you + + align:start position:0% +this decryption uh yeah the reason you + + + align:start position:0% +this decryption uh yeah the reason you +don't need circular security as it is + + align:start position:0% +don't need circular security as it is + + + align:start position:0% +don't need circular security as it is +for this F is that each of these + + align:start position:0% +for this F is that each of these + + + align:start position:0% +for this F is that each of these +computations is simple enough that you + + align:start position:0% +computations is simple enough that you + + + align:start position:0% +computations is simple enough that you +don't need to like the bo strap is that + + align:start position:0% +don't need to like the bo strap is that + + + align:start position:0% +don't need to like the bo strap is that +the reason Okay the reason I don't need + + align:start position:0% +the reason Okay the reason I don't need + + + align:start position:0% +the reason Okay the reason I don't need +uh uh um circular security is I'm I'm + + align:start position:0% +uh uh um circular security is I'm I'm + + + align:start position:0% +uh uh um circular security is I'm I'm +never + + align:start position:0% +never + + + align:start position:0% +never +encrypting a secret key under its + + align:start position:0% +encrypting a secret key under its + + + align:start position:0% +encrypting a secret key under its +publicy so sorry asking why the you're + + align:start position:0% +publicy so sorry asking why the you're + + + align:start position:0% +publicy so sorry asking why the you're +using not need to be + + align:start position:0% +using not need to be + + + align:start position:0% +using not need to be +unbounded oh oh oh okay okay okay you're + + align:start position:0% +unbounded oh oh oh okay okay okay you're + + + align:start position:0% +unbounded oh oh oh okay okay okay you're +saying okay sorry sorry you're you're + + align:start position:0% +saying okay sorry sorry you're you're + + + align:start position:0% +saying okay sorry sorry you're you're +asking okay got it you're saying well in + + align:start position:0% +asking okay got it you're saying well in + + + align:start position:0% +asking okay got it you're saying well in +general if we want arbitrary FHA we need + + align:start position:0% +general if we want arbitrary FHA we need + + + align:start position:0% +general if we want arbitrary FHA we need +to assume circular secure LW inside it + + align:start position:0% +to assume circular secure LW inside it + + + align:start position:0% +to assume circular secure LW inside it +kind of and you're asking do we not need + + align:start position:0% +kind of and you're asking do we not need + + + align:start position:0% +kind of and you're asking do we not need +to assum like you're kind of going into + + align:start position:0% +to assum like you're kind of going into + + + align:start position:0% +to assum like you're kind of going into +the you're saying do we actually need + + align:start position:0% +the you're saying do we actually need + + + align:start position:0% +the you're saying do we actually need +fully fully fully homomorphic encryption + + align:start position:0% +fully fully fully homomorphic encryption + + + align:start position:0% +fully fully fully homomorphic encryption +because if we do then actually we need + + align:start position:0% +because if we do then actually we need + + + align:start position:0% +because if we do then actually we need +to rely on like a circle security + + align:start position:0% +to rely on like a circle security + + + align:start position:0% +to rely on like a circle security +assumption inside too the answer is we + + align:start position:0% +assumption inside too the answer is we + + + align:start position:0% +assumption inside too the answer is we +we because the computation is very + + align:start position:0% +we because the computation is very + + + align:start position:0% +we because the computation is very +specific and very small depth you don't + + align:start position:0% +specific and very small depth you don't + + + align:start position:0% +specific and very small depth you don't +need to there's no you don't need like + + align:start position:0% +need to there's no you don't need like + + + align:start position:0% +need to there's no you don't need like +full full FH you need FH for very + + align:start position:0% +full full FH you need FH for very + + + align:start position:0% +full full FH you need FH for very +bounded depth + + align:start position:0% +bounded depth + + + align:start position:0% +bounded depth +computations yeah great thank you a any + + align:start position:0% +computations yeah great thank you a any + + + align:start position:0% +computations yeah great thank you a any +any other + + align:start position:0% + + + + align:start position:0% + +questions okay so let's + + align:start position:0% +questions okay so let's + + + align:start position:0% +questions okay so let's +snar well let me just make sure I + + align:start position:0% +snar well let me just make sure I + + + align:start position:0% +snar well let me just make sure I +covered everything I wanted + + align:start position:0% +covered everything I wanted + + + align:start position:0% +covered everything I wanted +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to okay after three months we SN we snar + + align:start position:0% +to okay after three months we SN we snar + + + align:start position:0% +to okay after three months we SN we snar +okay the last kind of two hours in class + + align:start position:0% +okay the last kind of two hours in class + + + align:start position:0% +okay the last kind of two hours in class +last we're going to + + align:start position:0% +last we're going to + + + align:start position:0% +last we're going to +snar okay + + align:start position:0% +snar okay + + + align:start position:0% +snar okay +so okay so now the snar is really simple + + align:start position:0% +so okay so now the snar is really simple + + + align:start position:0% +so okay so now the snar is really simple +it's like as simple as one can like you + + align:start position:0% +it's like as simple as one can like you + + + align:start position:0% +it's like as simple as one can like you +essentially can do it done we're done + + align:start position:0% +essentially can do it done we're done + + + align:start position:0% +essentially can do it done we're done +okay so how do we we can go home uh okay + + align:start position:0% + + + + align:start position:0% + +so anybody want a cookie before we + + align:start position:0% +so anybody want a cookie before we + + + align:start position:0% +so anybody want a cookie before we +snar I feel like these grandmothers that + + align:start position:0% +snar I feel like these grandmothers that + + + align:start position:0% +snar I feel like these grandmothers that +kind of you know constantly feed + + align:start position:0% +kind of you know constantly feed + + + align:start position:0% +kind of you know constantly feed +you okay so here's the idea the idea is + + align:start position:0% +you okay so here's the idea the idea is + + + align:start position:0% +you okay so here's the idea the idea is +very simple take any so + + align:start position:0% + + + + align:start position:0% + +snar okay so let me first say kind of + + align:start position:0% +snar okay so let me first say kind of + + + align:start position:0% +snar okay so let me first say kind of +the high level idea the high level idea + + align:start position:0% +the high level idea the high level idea + + + align:start position:0% +the high level idea the high level idea +is the following here's what the prover + + align:start position:0% +is the following here's what the prover + + + align:start position:0% +is the following here's what the prover +will do the so the prover wants to + + align:start position:0% +will do the so the prover wants to + + + align:start position:0% +will do the so the prover wants to +convince that X is in the language + + align:start position:0% +convince that X is in the language + + + align:start position:0% +convince that X is in the language +there's some verification circuit so you + + align:start position:0% +there's some verification circuit so you + + + align:start position:0% +there's some verification circuit so you +have X let's start with let's take X in + + align:start position:0% +have X let's start with let's take X in + + + align:start position:0% +have X let's start with let's take X in +the language + + align:start position:0% +the language + + + align:start position:0% +the language +or there is some for any X you know it + + align:start position:0% +or there is some for any X you know it + + + align:start position:0% +or there is some for any X you know it +doesn't matter for any + + align:start position:0% +doesn't matter for any + + + align:start position:0% +doesn't matter for any +X you have a circuit C + + align:start position:0% +X you have a circuit C + + + align:start position:0% +X you have a circuit C +subx and C subx takes a + + align:start position:0% +subx and C subx takes a + + + align:start position:0% +subx and C subx takes a +witness and now put 0 one like it's a + + align:start position:0% +witness and now put 0 one like it's a + + + align:start position:0% +witness and now put 0 one like it's a +verification circuit you can also think + + align:start position:0% +verification circuit you can also think + + + align:start position:0% +verification circuit you can also think +of it if you want + + align:start position:0% +of it if you want + + + align:start position:0% +of it if you want +c as taking X and a witness and I'll put + + align:start position:0% +c as taking X and a witness and I'll put + + + align:start position:0% +c as taking X and a witness and I'll put +zero if it's a not valid witness and one + + align:start position:0% +zero if it's a not valid witness and one + + + align:start position:0% +zero if it's a not valid witness and one +if it's a valid Witness if it's a + + align:start position:0% +if it's a valid Witness if it's a + + + align:start position:0% +if it's a valid Witness if it's a +deterministic computation there's no + + align:start position:0% +deterministic computation there's no + + + align:start position:0% +deterministic computation there's no +witness just say x and output zero or + + align:start position:0% +witness just say x and output zero or + + + align:start position:0% +witness just say x and output zero or +one that's the + + align:start position:0% +one that's the + + + align:start position:0% +one that's the +computation okay so when when I talk + + align:start position:0% +computation okay so when when I talk + + + align:start position:0% +computation okay so when when I talk +about snarky you can think of snar of + + align:start position:0% +about snarky you can think of snar of + + + align:start position:0% +about snarky you can think of snar of +non- deterministic snar of deterministic + + align:start position:0% +non- deterministic snar of deterministic + + + align:start position:0% +non- deterministic snar of deterministic +any language L I don't even want to go + + align:start position:0% +any language L I don't even want to go + + + align:start position:0% +any language L I don't even want to go +to specific okay but when I have a + + align:start position:0% +to specific okay but when I have a + + + align:start position:0% +to specific okay but when I have a +language L you know what how what does + + align:start position:0% +language L you know what how what does + + + align:start position:0% +language L you know what how what does +it mean a language well there's some + + align:start position:0% +it mean a language well there's some + + + align:start position:0% +it mean a language well there's some +circuit it takes the instance maybe with + + align:start position:0% +circuit it takes the instance maybe with + + + align:start position:0% +circuit it takes the instance maybe with +a witness and the circuit kind of does + + align:start position:0% +a witness and the circuit kind of does + + + align:start position:0% +a witness and the circuit kind of does +some checks to decide if it's valid or + + align:start position:0% +some checks to decide if it's valid or + + + align:start position:0% +some checks to decide if it's valid or +not valid + + align:start position:0% +not valid + + + align:start position:0% +not valid +okay now I want to convince you I have + + align:start position:0% +okay now I want to convince you I have + + + align:start position:0% +okay now I want to convince you I have +an X I want to give you a snar that this + + align:start position:0% +an X I want to give you a snar that this + + + align:start position:0% +an X I want to give you a snar that this +C an X outputs one either that there's a + + align:start position:0% +C an X outputs one either that there's a + + + align:start position:0% +C an X outputs one either that there's a +witness say that outputs one or maybe + + align:start position:0% +witness say that outputs one or maybe + + + align:start position:0% +witness say that outputs one or maybe +it's DET terministic so just C of X Out + + align:start position:0% +it's DET terministic so just C of X Out + + + align:start position:0% +it's DET terministic so just C of X Out +outputs one here's what I'm going to do + + align:start position:0% +outputs one here's what I'm going to do + + + align:start position:0% +outputs one here's what I'm going to do +what I'm going to do I'm going to + + align:start position:0% +what I'm going to do I'm going to + + + align:start position:0% +what I'm going to do I'm going to +compute all the wires of this circuit + + align:start position:0% +compute all the wires of this circuit + + + align:start position:0% +compute all the wires of this circuit +I'm all the wires and I'm going to give + + align:start position:0% +I'm all the wires and I'm going to give + + + align:start position:0% +I'm all the wires and I'm going to give +you a hash of all the wires now there's + + align:start position:0% +you a hash of all the wires now there's + + + align:start position:0% +you a hash of all the wires now there's +a lot of wires so it's going to be a + + align:start position:0% +a lot of wires so it's going to be a + + + align:start position:0% +a lot of wires so it's going to be a +shrinking + + align:start position:0% +shrinking + + + align:start position:0% +shrinking +hash I'm gonna actually use a somewh + + align:start position:0% +hash I'm gonna actually use a somewh + + + align:start position:0% +hash I'm gonna actually use a somewh +extractable + + align:start position:0% +extractable + + + align:start position:0% +extractable +hash + + align:start position:0% +hash + + + align:start position:0% +hash +so let's say we agreed on a hash key for + + align:start position:0% +so let's say we agreed on a hash key for + + + align:start position:0% +so let's say we agreed on a hash key for +somewhere extractable hash I the prover + + align:start position:0% +somewhere extractable hash I the prover + + + align:start position:0% +somewhere extractable hash I the prover +I'm going to compute all the wires of + + align:start position:0% +I'm going to compute all the wires of + + + align:start position:0% +I'm going to compute all the wires of +this verification + + align:start position:0% +this verification + + + align:start position:0% +this verification +circuit and I'm going to give you the + + align:start position:0% +circuit and I'm going to give you the + + + align:start position:0% +circuit and I'm going to give you the +hash the hash of the the values of all + + align:start position:0% +hash the hash of the the values of all + + + align:start position:0% +hash the hash of the the values of all +the + + align:start position:0% +the + + + align:start position:0% +the +wires okay hash what are you going to do + + align:start position:0% +wires okay hash what are you going to do + + + align:start position:0% +wires okay hash what are you going to do +with that so the other thing I'm going + + align:start position:0% +with that so the other thing I'm going + + + align:start position:0% +with that so the other thing I'm going +to give you is I'm going to give you a + + align:start position:0% +to give you is I'm going to give you a + + + align:start position:0% +to give you is I'm going to give you a +bar a proof a bar of what the bark I'm + + align:start position:0% +bar a proof a bar of what the bark I'm + + + align:start position:0% +bar a proof a bar of what the bark I'm +going to give you is that every gate + + align:start position:0% +going to give you is that every gate + + + align:start position:0% +going to give you is that every gate +here is satisfied so I committed to all + + align:start position:0% +here is satisfied so I committed to all + + + align:start position:0% +here is satisfied so I committed to all +the wires I can commit to anything I I + + align:start position:0% +the wires I can commit to anything I I + + + align:start position:0% +the wires I can commit to anything I I +mean I hashed all the wires now I'm + + align:start position:0% +mean I hashed all the wires now I'm + + + align:start position:0% +mean I hashed all the wires now I'm +going to prove to you that for any gate + + align:start position:0% +going to prove to you that for any gate + + + align:start position:0% +going to prove to you that for any gate +if you look at kind of the + + align:start position:0% +if you look at kind of the + + + align:start position:0% +if you look at kind of the +two the in the two input wires to the + + align:start position:0% +two the in the two input wires to the + + + align:start position:0% +two the in the two input wires to the +gate and the output wire of the gate + + align:start position:0% +gate and the output wire of the gate + + + align:start position:0% +gate and the output wire of the gate +they satisfy the gate so for any for all + + align:start position:0% +they satisfy the gate so for any for all + + + align:start position:0% +they satisfy the gate so for any for all +every gate in the circuit I'm going to + + align:start position:0% +every gate in the circuit I'm going to + + + align:start position:0% +every gate in the circuit I'm going to +prove to you that there exists an + + align:start position:0% +prove to you that there exists an + + + align:start position:0% +prove to you that there exists an +opening to this wire and an opening to + + align:start position:0% +opening to this wire and an opening to + + + align:start position:0% +opening to this wire and an opening to +this wire and to this wire such that + + align:start position:0% +this wire and to this wire such that + + + align:start position:0% +this wire and to this wire such that +these openings are valid and that the + + align:start position:0% +these openings are valid and that the + + + align:start position:0% +these openings are valid and that the +values that I opened accept the the kind + + align:start position:0% +values that I opened accept the the kind + + + align:start position:0% +values that I opened accept the the kind +of respect the + + align:start position:0% +of respect the + + + align:start position:0% +of respect the +gate and I'm going to prove to you that + + align:start position:0% +gate and I'm going to prove to you that + + + align:start position:0% +gate and I'm going to prove to you that +the + + align:start position:0% +the + + + align:start position:0% +the +output that so I I I I said that I I + + align:start position:0% +output that so I I I I said that I I + + + align:start position:0% +output that so I I I I said that I I +hashed all the wires I'm going to argue + + align:start position:0% +hashed all the wires I'm going to argue + + + align:start position:0% +hashed all the wires I'm going to argue +I'm going to open the output wire so you + + align:start position:0% +I'm going to open the output wire so you + + + align:start position:0% +I'm going to open the output wire so you +see the end output is one so again what + + align:start position:0% +see the end output is one so again what + + + align:start position:0% +see the end output is one so again what +am I going to do I want to I want to + + align:start position:0% +am I going to do I want to I want to + + + align:start position:0% +am I going to do I want to I want to +convince you that the output here is + + align:start position:0% +convince you that the output here is + + + align:start position:0% +convince you that the output here is +one I'm going to Hash all the wires the + + align:start position:0% +one I'm going to Hash all the wires the + + + align:start position:0% +one I'm going to Hash all the wires the +value of all the wires in the + + align:start position:0% +value of all the wires in the + + + align:start position:0% +value of all the wires in the +circuit I'm going to prove that every + + align:start position:0% +circuit I'm going to prove that every + + + align:start position:0% +circuit I'm going to prove that every +gate is kind of satisfied I have an + + align:start position:0% +gate is kind of satisfied I have an + + + align:start position:0% +gate is kind of satisfied I have an +opening that's kind of respects each and + + align:start position:0% +opening that's kind of respects each and + + + align:start position:0% +opening that's kind of respects each and +every gate and the output wire is + + align:start position:0% +every gate and the output wire is + + + align:start position:0% +every gate and the output wire is +one that's my SN yeah how's this + + align:start position:0% +one that's my SN yeah how's this + + + align:start position:0% +one that's my SN yeah how's this +different from gkr okay how is this + + align:start position:0% +different from gkr okay how is this + + + align:start position:0% +different from gkr okay how is this +different from gkr uh G okay so gkr is + + align:start position:0% +different from gkr uh G okay so gkr is + + + align:start position:0% +different from gkr uh G okay so gkr is +uh is very different in many ways first + + align:start position:0% +uh is very different in many ways first + + + align:start position:0% +uh is very different in many ways first +of all it's a interactive protocol now + + align:start position:0% +of all it's a interactive protocol now + + + align:start position:0% +of all it's a interactive protocol now +you can apply F to it but essentially in + + align:start position:0% +you can apply F to it but essentially in + + + align:start position:0% +you can apply F to it but essentially in +gkr you kind of take the circuit you + + align:start position:0% +gkr you kind of take the circuit you + + + align:start position:0% +gkr you kind of take the circuit you +compute all the wires in the circuit but + + align:start position:0% +compute all the wires in the circuit but + + + align:start position:0% +compute all the wires in the circuit but +actually I don't bar say look all the + + align:start position:0% +actually I don't bar say look all the + + + align:start position:0% +actually I don't bar say look all the +wires are satisfied instead I'm going to + + align:start position:0% +wires are satisfied instead I'm going to + + + align:start position:0% +wires are satisfied instead I'm going to +kind of we're doing an interactive + + align:start position:0% +kind of we're doing an interactive + + + align:start position:0% +kind of we're doing an interactive +process saying oh I'm going to I argue + + align:start position:0% +process saying oh I'm going to I argue + + + align:start position:0% +process saying oh I'm going to I argue +the output wies one and then we do kind + + align:start position:0% +the output wies one and then we do kind + + + align:start position:0% +the output wies one and then we do kind +of a little sum check or some inve + + align:start position:0% +of a little sum check or some inve + + + align:start position:0% +of a little sum check or some inve +process to reduce checking that value to + + align:start position:0% +process to reduce checking that value to + + + align:start position:0% +process to reduce checking that value to +checking a value in one layer below and + + align:start position:0% +checking a value in one layer below and + + + align:start position:0% +checking a value in one layer below and +then we do an instructive process to say + + align:start position:0% +then we do an instructive process to say + + + align:start position:0% +then we do an instructive process to say +Okay if that was false you know then the + + align:start position:0% +Okay if that was false you know then the + + + align:start position:0% +Okay if that was false you know then the +layer below needs to be false until we + + align:start position:0% +layer below needs to be false until we + + + align:start position:0% +layer below needs to be false until we +reach the the leaves and then you can + + align:start position:0% +reach the the leaves and then you can + + + align:start position:0% +reach the the leaves and then you can +apply F chamir to that to kind of make + + align:start position:0% +apply F chamir to that to kind of make + + + align:start position:0% +apply F chamir to that to kind of make +it a + + align:start position:0% +it a + + + align:start position:0% +it a +snar here we're doing something very + + align:start position:0% +snar here we're doing something very + + + align:start position:0% +snar here we're doing something very +differently we're starting with a bar + + align:start position:0% +differently we're starting with a bar + + + align:start position:0% +differently we're starting with a bar +now it's true that the construction you + + align:start position:0% +now it's true that the construction you + + + align:start position:0% +now it's true that the construction you +saw for bar uses F also but some + + align:start position:0% +saw for bar uses F also but some + + + align:start position:0% +saw for bar uses F also but some +constructions don't use f actually for + + align:start position:0% +constructions don't use f actually for + + + align:start position:0% +constructions don't use f actually for +bar there are various constructions of + + align:start position:0% +bar there are various constructions of + + + align:start position:0% +bar there are various constructions of +bargs you saw one of them but there are + + align:start position:0% +bargs you saw one of them but there are + + + align:start position:0% +bargs you saw one of them but there are +others so we say take any + + align:start position:0% +others so we say take any + + + align:start position:0% +others so we say take any +bar and there's no interaction here like + + align:start position:0% +bar and there's no interaction here like + + + align:start position:0% +bar and there's no interaction here like +besides maybe they're inside the bark + + align:start position:0% +besides maybe they're inside the bark + + + align:start position:0% +besides maybe they're inside the bark +but maybe the bark doesn't have any F or + + align:start position:0% +but maybe the bark doesn't have any F or + + + align:start position:0% +but maybe the bark doesn't have any F or +anything to it and we're saying just + + align:start position:0% +anything to it and we're saying just + + + align:start position:0% +anything to it and we're saying just +hash all the wires of the circuit and + + align:start position:0% +hash all the wires of the circuit and + + + align:start position:0% +hash all the wires of the circuit and +prove that everything is consistent + + align:start position:0% +prove that everything is consistent + + + align:start position:0% +prove that everything is consistent +that's + + align:start position:0% +that's + + + align:start position:0% +that's +it that's really what we're + + align:start position:0% +it that's really what we're + + + align:start position:0% +it that's really what we're +doing so let me write this down so it + + align:start position:0% +doing so let me write this down so it + + + align:start position:0% +doing so let me write this down so it +will be so that my ingredients that I + + align:start position:0% +will be so that my ingredients that I + + + align:start position:0% +will be so that my ingredients that I +have for my snar is uh so okay so + + align:start position:0% +have for my snar is uh so okay so + + + align:start position:0% +have for my snar is uh so okay so +ingredients maybe I'll write it + + align:start position:0% + + + + align:start position:0% + +here so my + + align:start position:0% + + + + align:start position:0% + +ingredients is a + + align:start position:0% +ingredients is a + + + align:start position:0% +ingredients is a +bar and Sumer extractable + + align:start position:0% +bar and Sumer extractable + + + align:start position:0% +bar and Sumer extractable +hash these are my ingredients and I'm + + align:start position:0% +hash these are my ingredients and I'm + + + align:start position:0% +hash these are my ingredients and I'm +going to show you my snar okay so snar + + align:start position:0% +going to show you my snar okay so snar + + + align:start position:0% +going to show you my snar okay so snar +has uh three algorithms we have a gen + + align:start position:0% + + + + align:start position:0% + +algorithm and here's what my gen + + align:start position:0% +algorithm and here's what my gen + + + align:start position:0% +algorithm and here's what my gen +algorithm is going to + + align:start position:0% +algorithm is going to + + + align:start position:0% +algorithm is going to +do it's going to let's say the Gen also + + align:start position:0% +do it's going to let's say the Gen also + + + align:start position:0% +do it's going to let's say the Gen also +has an input + + align:start position:0% + + + + align:start position:0% + +length ah we don't need it + + align:start position:0% +length ah we don't need it + + + align:start position:0% +length ah we don't need it +okay here's what it's going to okay + + align:start position:0% +okay here's what it's going to okay + + + align:start position:0% +okay here's what it's going to okay +let's say it has an input + + align:start position:0% +let's say it has an input + + + align:start position:0% +let's say it has an input +length so this says you know you're + + align:start position:0% +length so this says you know you're + + + align:start position:0% +length so this says you know you're +going to prove to me statements of + + align:start position:0% +going to prove to me statements of + + + align:start position:0% +going to prove to me statements of +length that the input X is of length n + + align:start position:0% +length that the input X is of length n + + + align:start position:0% +length that the input X is of length n +okay so here's what we're going to do + + align:start position:0% +okay so here's what we're going to do + + + align:start position:0% +okay so here's what we're going to do +first thing we do is we're going to + + align:start position:0% + + + + align:start position:0% + +generate a hash + + align:start position:0% + + + + align:start position:0% + +key for Gen of the Sumer extractable + + align:start position:0% +key for Gen of the Sumer extractable + + + align:start position:0% +key for Gen of the Sumer extractable +hash so generate a hash key + + align:start position:0% +hash so generate a hash key + + + align:start position:0% +hash so generate a hash key +corresponding to the summer extractable + + align:start position:0% +corresponding to the summer extractable + + + align:start position:0% +corresponding to the summer extractable +hash this is going to be with security + + align:start position:0% +hash this is going to be with security + + + align:start position:0% +hash this is going to be with security +parameter n is going to + + align:start position:0% +parameter n is going to + + + align:start position:0% +parameter n is going to +be this is going to be number of + + align:start position:0% +be this is going to be number of + + + align:start position:0% +be this is going to be number of +wires in the circuit C this is the + + align:start position:0% +wires in the circuit C this is the + + + align:start position:0% +wires in the circuit C this is the +circuit that takes X of length n + + align:start position:0% +circuit that takes X of length n + + + align:start position:0% +circuit that takes X of length n +possibly a witness and output zero or + + align:start position:0% +possibly a witness and output zero or + + + align:start position:0% +possibly a witness and output zero or +one okay so this is going to be the + + align:start position:0% +one okay so this is going to be the + + + align:start position:0% +one okay so this is going to be the +number of wires and take any I I don't + + align:start position:0% +number of wires and take any I I don't + + + align:start position:0% +number of wires and take any I I don't +know whatever I equals 1 take any I in + + align:start position:0% +know whatever I equals 1 take any I in + + + align:start position:0% +know whatever I equals 1 take any I in +between one to n it doesn't matter + + align:start position:0% +between one to n it doesn't matter + + + align:start position:0% +between one to n it doesn't matter +choose it arbitrarily your favorite + + align:start position:0% +choose it arbitrarily your favorite + + + align:start position:0% +choose it arbitrarily your favorite +number okay so that's first thing and + + align:start position:0% +number okay so that's first thing and + + + align:start position:0% +number okay so that's first thing and +then you also generate a CRS for the bar + + align:start position:0% +then you also generate a CRS for the bar + + + align:start position:0% +then you also generate a CRS for the bar +so you + + align:start position:0% + + + + align:start position:0% + +generate a CRS for + + align:start position:0% + + + + align:start position:0% + +bar this is for the + + align:start position:0% +bar this is for the + + + align:start position:0% +bar this is for the +bar and this will be with input one to + + align:start position:0% +bar and this will be with input one to + + + align:start position:0% +bar and this will be with input one to +the with the sc one to the Lambda K the + + align:start position:0% +the with the sc one to the Lambda K the + + + align:start position:0% +the with the sc one to the Lambda K the +number of statements is like the number + + align:start position:0% +number of statements is like the number + + + align:start position:0% +number of statements is like the number +of gates in the circuit so K is going to + + align:start position:0% +of gates in the circuit so K is going to + + + align:start position:0% +of gates in the circuit so K is going to +be number of + + align:start position:0% +be number of + + + align:start position:0% +be number of +gates in C because we're going to + + align:start position:0% +gates in C because we're going to + + + align:start position:0% +gates in C because we're going to +remember we're going to say we're going + + align:start position:0% +remember we're going to say we're going + + + align:start position:0% +remember we're going to say we're going +to prove that for every gate is + + align:start position:0% +to prove that for every gate is + + + align:start position:0% +to prove that for every gate is +satisfied so usually K and N are very + + align:start position:0% +satisfied so usually K and N are very + + + align:start position:0% +satisfied so usually K and N are very +similar it's like essentially the same + + align:start position:0% +similar it's like essentially the same + + + align:start position:0% +similar it's like essentially the same +number but you know uh let me just be + + align:start position:0% +number but you know uh let me just be + + + align:start position:0% +number but you know uh let me just be +clear that this is we're going to have + + align:start position:0% +clear that this is we're going to have + + + align:start position:0% +clear that this is we're going to have +the number of gates and the length n + + align:start position:0% +the number of gates and the length n + + + align:start position:0% +the number of gates and the length n +there and let me call it n Prime we'll + + align:start position:0% +there and let me call it n Prime we'll + + + align:start position:0% +there and let me call it n Prime we'll +see what it is it's a we'll see what + + align:start position:0% +see what it is it's a we'll see what + + + align:start position:0% +see what it is it's a we'll see what +this n Prime is in a in a minute so the + + align:start position:0% +this n Prime is in a in a minute so the + + + align:start position:0% +this n Prime is in a in a minute so the +we're going to Bar statements not of + + align:start position:0% +we're going to Bar statements not of + + + align:start position:0% +we're going to Bar statements not of +length n but of a different length n + + align:start position:0% +length n but of a different length n + + + align:start position:0% +length n but of a different length n +Prime we're going to see what that is + + align:start position:0% +Prime we're going to see what that is + + + align:start position:0% +Prime we're going to see what that is +but the output is just + + align:start position:0% + + + + align:start position:0% + +a uh let me call this CRS bar so you + + align:start position:0% +a uh let me call this CRS bar so you + + + align:start position:0% +a uh let me call this CRS bar so you +output CRS which is equal to Hash key + + align:start position:0% +output CRS which is equal to Hash key + + + align:start position:0% +output CRS which is equal to Hash key +and CRS + + align:start position:0% + + + + align:start position:0% + +bar okay so that's how you generate so + + align:start position:0% +bar okay so that's how you generate so + + + align:start position:0% +bar okay so that's how you generate so +the key generation the CRS has a CRS for + + align:start position:0% +the key generation the CRS has a CRS for + + + align:start position:0% +the key generation the CRS has a CRS for +the bar and a hash + + align:start position:0% +the bar and a hash + + + align:start position:0% +the bar and a hash +key now we're going going + + align:start position:0% +key now we're going going + + + align:start position:0% +key now we're going going +to + + align:start position:0% +to + + + align:start position:0% +to +a uh what does the prover do so the + + align:start position:0% +a uh what does the prover do so the + + + align:start position:0% +a uh what does the prover do so the +prover gets his input X maybe a witness + + align:start position:0% +prover gets his input X maybe a witness + + + align:start position:0% +prover gets his input X maybe a witness +if it's an + + align:start position:0% +if it's an + + + align:start position:0% +if it's an +NP maybe there's no witness let me say + + align:start position:0% +NP maybe there's no witness let me say + + + align:start position:0% +NP maybe there's no witness let me say +generally with a witness but uh actually + + align:start position:0% +generally with a witness but uh actually + + + align:start position:0% +generally with a witness but uh actually +the bar we're going to construct today + + align:start position:0% +the bar we're going to construct today + + + align:start position:0% +the bar we're going to construct today +is going to be for deterministic + + align:start position:0% +is going to be for deterministic + + + align:start position:0% +is going to be for deterministic +languages but let me write it also for + + align:start position:0% +languages but let me write it also for + + + align:start position:0% +languages but let me write it also for +because I'm going to show you kind of a + + align:start position:0% +because I'm going to show you kind of a + + + align:start position:0% +because I'm going to show you kind of a +general + + align:start position:0% +general + + + align:start position:0% +general +framework so p is going to get a CRS + + align:start position:0% +framework so p is going to get a CRS + + + align:start position:0% +framework so p is going to get a CRS +X and maybe a witness if it's an + + align:start position:0% +X and maybe a witness if it's an + + + align:start position:0% +X and maybe a witness if it's an +NP and he needs to generate a snar so + + align:start position:0% +NP and he needs to generate a snar so + + + align:start position:0% +NP and he needs to generate a snar so +what does he what does it do + + align:start position:0% + + + + align:start position:0% + +compute all the wires in the circuit so + + align:start position:0% +compute all the wires in the circuit so + + + align:start position:0% +compute all the wires in the circuit so +X is fixed let's think of X is like + + align:start position:0% +X is fixed let's think of X is like + + + align:start position:0% +X is fixed let's think of X is like +that's not part of the wires because + + align:start position:0% +that's not part of the wires because + + + align:start position:0% +that's not part of the wires because +it's fixed but let's compute all the + + align:start position:0% +it's fixed but let's compute all the + + + align:start position:0% +it's fixed but let's compute all the +like + + align:start position:0% +like + + + align:start position:0% +like +W1 up to w a n which is the wires of the + + align:start position:0% +W1 up to w a n which is the wires of the + + + align:start position:0% +W1 up to w a n which is the wires of the +circuit you can think of the first m has + + align:start position:0% +circuit you can think of the first m has + + + align:start position:0% +circuit you can think of the first m has +kind of the actual witness let's say the + + align:start position:0% +kind of the actual witness let's say the + + + align:start position:0% +kind of the actual witness let's say the +if you have a witness and it's of length + + align:start position:0% +if you have a witness and it's of length + + + align:start position:0% +if you have a witness and it's of length +M W1 w m is the witness but then the + + align:start position:0% +M W1 w m is the witness but then the + + + align:start position:0% +M W1 w m is the witness but then the +rest are the wires so I'm thinking the + + align:start position:0% +rest are the wires so I'm thinking the + + + align:start position:0% +rest are the wires so I'm thinking the +wires include kind of the witness and + + align:start position:0% +wires include kind of the witness and + + + align:start position:0% +wires include kind of the witness and +everything above and if there's no + + align:start position:0% +everything above and if there's no + + + align:start position:0% +everything above and if there's no +witness then it doesn't include a + + align:start position:0% +witness then it doesn't include a + + + align:start position:0% +witness then it doesn't include a +witness so I compute these are all the + + align:start position:0% + + + + align:start position:0% + +wires in + + align:start position:0% +wires in + + + align:start position:0% +wires in +C except + + align:start position:0% +C except + + + align:start position:0% +C except +X except the input Y is corresponding + + align:start position:0% +X except the input Y is corresponding + + + align:start position:0% +X except the input Y is corresponding +the input Y is corresponding to X cuz + + align:start position:0% +the input Y is corresponding to X cuz + + + align:start position:0% +the input Y is corresponding to X cuz +that's kind of we know what it is the + + align:start position:0% +that's kind of we know what it is the + + + align:start position:0% +that's kind of we know what it is the +verifier knows + + align:start position:0% +verifier knows + + + align:start position:0% +verifier knows +it okay so you compute all the wires and + + align:start position:0% +it okay so you compute all the wires and + + + align:start position:0% +it okay so you compute all the wires and +then you + + align:start position:0% +then you + + + align:start position:0% +then you +compute hash of the you compute V which + + align:start position:0% +compute hash of the you compute V which + + + align:start position:0% +compute hash of the you compute V which +is a hash the + + align:start position:0% +is a hash the + + + align:start position:0% +is a hash the +eval with hash key of W1 up to + + align:start position:0% +eval with hash key of W1 up to + + + align:start position:0% +eval with hash key of W1 up to +WN so you hash all these wires together + + align:start position:0% +WN so you hash all these wires together + + + align:start position:0% +WN so you hash all these wires together +okay so the verifier computed all the + + align:start position:0% +okay so the verifier computed all the + + + align:start position:0% +okay so the verifier computed all the +wires of the + + align:start position:0% +wires of the + + + align:start position:0% +wires of the +circuit hashed all the + + align:start position:0% +circuit hashed all the + + + align:start position:0% +circuit hashed all the +wires oh uh okay actually let me just + + align:start position:0% +wires oh uh okay actually let me just + + + align:start position:0% +wires oh uh okay actually let me just +say + + align:start position:0% + + + + align:start position:0% + +sorry when you generate a key I said you + + align:start position:0% +sorry when you generate a key I said you + + + align:start position:0% +sorry when you generate a key I said you +know use a a a su constructible hash yes + + align:start position:0% +know use a a a su constructible hash yes + + + align:start position:0% +know use a a a su constructible hash yes +exactly but let's you don't need to just + + align:start position:0% +exactly but let's you don't need to just + + + align:start position:0% +exactly but let's you don't need to just +use one index okay so let's use it with + + align:start position:0% +use one index okay so let's use it with + + + align:start position:0% +use one index okay so let's use it with +few index i l now you can ask what is + + align:start position:0% +few index i l now you can ask what is + + + align:start position:0% +few index i l now you can ask what is +L we'll see you know you can think of it + + align:start position:0% +L we'll see you know you can think of it + + + align:start position:0% +L we'll see you know you can think of it +as a few L's you can think of poly log l + + align:start position:0% +as a few L's you can think of poly log l + + + align:start position:0% +as a few L's you can think of poly log l +the bigger the is the less extinct the + + align:start position:0% +the bigger the is the less extinct the + + + align:start position:0% +the bigger the is the less extinct the +snar is going to be so the snar is going + + align:start position:0% +snar is going to be so the snar is going + + + align:start position:0% +snar is going to be so the snar is going +to grow with L because the hash key + + align:start position:0% +to grow with L because the hash key + + + align:start position:0% +to grow with L because the hash key +grows with L it's like L hash Keys + + align:start position:0% +grows with L it's like L hash Keys + + + align:start position:0% +grows with L it's like L hash Keys +essentially because we're + + align:start position:0% +essentially because we're + + + align:start position:0% +essentially because we're +repeating so here I'm going to be + + align:start position:0% +repeating so here I'm going to be + + + align:start position:0% +repeating so here I'm going to be +binding on L + + align:start position:0% + + + + align:start position:0% + +locations the hash value grow with L + + align:start position:0% +locations the hash value grow with L + + + align:start position:0% +locations the hash value grow with L +because you're like you're Computing + + align:start position:0% +because you're like you're Computing + + + align:start position:0% +because you're like you're Computing +essentially L hash values so the more + + align:start position:0% +essentially L hash values so the more + + + align:start position:0% +essentially L hash values so the more +the bigger L is in some sense the more + + align:start position:0% +the bigger L is in some sense the more + + + align:start position:0% +the bigger L is in some sense the more +secure we're going to we're going to get + + align:start position:0% +secure we're going to we're going to get + + + align:start position:0% +secure we're going to we're going to get +we'll see but the more non succinct it's + + align:start position:0% +we'll see but the more non succinct it's + + + align:start position:0% +we'll see but the more non succinct it's +going to be so L now is going to be a + + align:start position:0% +going to be so L now is going to be a + + + align:start position:0% +going to be so L now is going to be a +parameter and when we talk about then + + align:start position:0% +parameter and when we talk about then + + + align:start position:0% +parameter and when we talk about then +Elis we'll see which L we want yeah is + + align:start position:0% +Elis we'll see which L we want yeah is + + + align:start position:0% +Elis we'll see which L we want yeah is +there any hope for getting like + + align:start position:0% +there any hope for getting like + + + align:start position:0% +there any hope for getting like +sublinear dependence in L like any other + + align:start position:0% +sublinear dependence in L like any other + + + align:start position:0% +sublinear dependence in L like any other +construction instead of a direct product + + align:start position:0% +construction instead of a direct product + + + align:start position:0% +construction instead of a direct product +construction so okay in V there's no way + + align:start position:0% +construction so okay in V there's no way + + + align:start position:0% +construction so okay in V there's no way +to get sublinear and L because you need + + align:start position:0% +to get sublinear and L because you need + + + align:start position:0% +to get sublinear and L because you need +to extract it's like a there's must have + + align:start position:0% +to extract it's like a there's must have + + + align:start position:0% +to extract it's like a there's must have +information so in V there's no way to + + align:start position:0% +information so in V there's no way to + + + align:start position:0% +information so in V there's no way to +have to have in the Hat key on the other + + align:start position:0% +have to have in the Hat key on the other + + + align:start position:0% +have to have in the Hat key on the other +hand + + align:start position:0% +hand + + + align:start position:0% +hand +um okay if the I I want up to I L can be + + align:start position:0% +um okay if the I I want up to I L can be + + + align:start position:0% +um okay if the I I want up to I L can be +shrunk somehow if there's a sucin + + align:start position:0% +shrunk somehow if there's a sucin + + + align:start position:0% +shrunk somehow if there's a sucin +description of i1 to I for example in + + align:start position:0% +description of i1 to I for example in + + + align:start position:0% +description of i1 to I for example in +the case of a witness you know I'm I + + align:start position:0% +the case of a witness you know I'm I + + + align:start position:0% +the case of a witness you know I'm I +want to be extractable and witness I + + align:start position:0% +want to be extractable and witness I + + + align:start position:0% +want to be extractable and witness I +these are consecutive locations so I + + align:start position:0% +these are consecutive locations so I + + + align:start position:0% +these are consecutive locations so I +don't need to write location I I plus + + align:start position:0% +don't need to write location I I plus + + + align:start position:0% +don't need to write location I I plus +one I plus you can just say I and go + + align:start position:0% +one I plus you can just say I and go + + + align:start position:0% +one I plus you can just say I and go +from I to n there's a very suin + + align:start position:0% +from I to n there's a very suin + + + align:start position:0% +from I to n there's a very suin +description in the case where there's Su + + align:start position:0% +description in the case where there's Su + + + align:start position:0% +description in the case where there's Su +description + + align:start position:0% +description + + + align:start position:0% +description +you can hope to get the hash key + + align:start position:0% +you can hope to get the hash key + + + align:start position:0% +you can hope to get the hash key +smaller and we do know how to get the + + align:start position:0% +smaller and we do know how to get the + + + align:start position:0% +smaller and we do know how to get the +hash key smaller but in general uh for + + align:start position:0% +hash key smaller but in general uh for + + + align:start position:0% +hash key smaller but in general uh for +the Val value there's no way information + + align:start position:0% +the Val value there's no way information + + + align:start position:0% +the Val value there's no way information +theoretically great great + + align:start position:0% +theoretically great great + + + align:start position:0% +theoretically great great +question okay so a okay so you compute + + align:start position:0% +question okay so a okay so you compute + + + align:start position:0% +question okay so a okay so you compute +the the hash value of all the wires and + + align:start position:0% +the the hash value of all the wires and + + + align:start position:0% +the the hash value of all the wires and +then you add a Barb so the last thing + + align:start position:0% +then you add a Barb so the last thing + + + align:start position:0% +then you add a Barb so the last thing +you do is you + + align:start position:0% + + + + align:start position:0% + +compute uh the P bar like you take the a + + align:start position:0% +compute uh the P bar like you take the a + + + align:start position:0% +compute uh the P bar like you take the a +bar + + align:start position:0% +bar + + + align:start position:0% +bar +prover and here's our bar prover you + + align:start position:0% +prover and here's our bar prover you + + + align:start position:0% +prover and here's our bar prover you +give it CRS of + + align:start position:0% + + + + align:start position:0% + +bar and you have axes and Witnesses now + + align:start position:0% +bar and you have axes and Witnesses now + + + align:start position:0% +bar and you have axes and Witnesses now +what are the axes and the witnesses okay + + align:start position:0% +what are the axes and the witnesses okay + + + align:start position:0% +what are the axes and the witnesses okay +I want to use I want to argue I'm going + + align:start position:0% +I want to use I want to argue I'm going + + + align:start position:0% +I want to use I want to argue I'm going +to generate a bunch of axes and + + align:start position:0% +to generate a bunch of axes and + + + align:start position:0% +to generate a bunch of axes and +Witnesses and generate a proof so what + + align:start position:0% +Witnesses and generate a proof so what + + + align:start position:0% +Witnesses and generate a proof so what +is it that I'm what are so I'm going to + + align:start position:0% +is it that I'm what are so I'm going to + + + align:start position:0% +is it that I'm what are so I'm going to +give you X1 star x k star and W1 star + + align:start position:0% +give you X1 star x k star and W1 star + + + align:start position:0% +give you X1 star x k star and W1 star +I'll tell you what these are in a second + + align:start position:0% +I'll tell you what these are in a second + + + align:start position:0% +I'll tell you what these are in a second +w k star so this is going to be Pi this + + align:start position:0% +w k star so this is going to be Pi this + + + align:start position:0% +w k star so this is going to be Pi this +is going to be + + align:start position:0% + + + + align:start position:0% + +compute Pi + + align:start position:0% +compute Pi + + + align:start position:0% +compute Pi +Bar so you bar case statements but what + + align:start position:0% +Bar so you bar case statements but what + + + align:start position:0% +Bar so you bar case statements but what +are these statements so so let me just + + align:start position:0% +are these statements so so let me just + + + align:start position:0% +are these statements so so let me just +tell you what these and these + + align:start position:0% +tell you what these and these + + + align:start position:0% +tell you what these and these +are + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +X star J + + align:start position:0% +X star J + + + align:start position:0% +X star J +is essentially it's going to it's going + + align:start position:0% +is essentially it's going to it's going + + + align:start position:0% +is essentially it's going to it's going +to be hash + + align:start position:0% +to be hash + + + align:start position:0% +to be hash +key value and + + align:start position:0% +key value and + + + align:start position:0% +key value and +J okay that's X that so what I'm going + + align:start position:0% +J okay that's X that so what I'm going + + + align:start position:0% +J okay that's X that so what I'm going +to prove that for each gate + + align:start position:0% +to prove that for each gate + + + align:start position:0% +to prove that for each gate +J I have an opening to the input wires + + align:start position:0% +J I have an opening to the input wires + + + align:start position:0% +J I have an opening to the input wires +of the gate and the out wire of the gate + + align:start position:0% +of the gate and the out wire of the gate + + + align:start position:0% +of the gate and the out wire of the gate +with respect I have an opening with + + align:start position:0% +with respect I have an opening with + + + align:start position:0% +with respect I have an opening with +respect to V that satisfi the gate okay + + align:start position:0% +respect to V that satisfi the gate okay + + + align:start position:0% +respect to V that satisfi the gate okay +so the XJ is going to be well I have the + + align:start position:0% +so the XJ is going to be well I have the + + + align:start position:0% +so the XJ is going to be well I have the +hash ke I have the hash value and gate J + + align:start position:0% +hash ke I have the hash value and gate J + + + align:start position:0% +hash ke I have the hash value and gate J +and the witness for gate J is going to + + align:start position:0% +and the witness for gate J is going to + + + align:start position:0% +and the witness for gate J is going to +be opening so I'm going to have a like + + align:start position:0% +be opening so I'm going to have a like + + + align:start position:0% +be opening so I'm going to have a like +bit uh like a left child right child + + align:start position:0% +bit uh like a left child right child + + + align:start position:0% +bit uh like a left child right child +output + + align:start position:0% +output + + + align:start position:0% +output +child not child I'll put the + + align:start position:0% +child not child I'll put the + + + align:start position:0% +child not child I'll put the +parent uh so left child right right + + align:start position:0% +parent uh so left child right right + + + align:start position:0% +parent uh so left child right right +child and parent of the + + align:start position:0% +child and parent of the + + + align:start position:0% +child and parent of the +gate opening row of left child row of + + align:start position:0% +gate opening row of left child row of + + + align:start position:0% +gate opening row of left child row of +right child row of the + + align:start position:0% + + + + align:start position:0% + +output that's going to be a witness and + + align:start position:0% +output that's going to be a witness and + + + align:start position:0% +output that's going to be a witness and +it's a valid witness + + align:start position:0% +it's a valid witness + + + align:start position:0% +it's a valid witness +if b0 row zero are valid opening of the + + align:start position:0% +if b0 row zero are valid opening of the + + + align:start position:0% +if b0 row zero are valid opening of the +left + + align:start position:0% +left + + + align:start position:0% +left +child of + + align:start position:0% +child of + + + align:start position:0% +child of +GJ B1 Row one are a valid opening of the + + align:start position:0% +GJ B1 Row one are a valid opening of the + + + align:start position:0% +GJ B1 Row one are a valid opening of the +right child of gate J B out and row out + + align:start position:0% +right child of gate J B out and row out + + + align:start position:0% +right child of gate J B out and row out +are valid openings of the output wire of + + align:start position:0% +are valid openings of the output wire of + + + align:start position:0% +are valid openings of the output wire of +gate J + + align:start position:0% +gate J + + + align:start position:0% +gate J +and these satisfy the gate so if it's a + + align:start position:0% +and these satisfy the gate so if it's a + + + align:start position:0% +and these satisfy the gate so if it's a +end gate this and this is + + align:start position:0% +end gate this and this is + + + align:start position:0% +end gate this and this is +this okay that's gonna that's what + + align:start position:0% +this okay that's gonna that's what + + + align:start position:0% +this okay that's gonna that's what +that's G to that's so a valid witness is + + align:start position:0% +that's G to that's so a valid witness is + + + align:start position:0% +that's G to that's so a valid witness is +a six tupo like this that all these + + align:start position:0% +a six tupo like this that all these + + + align:start position:0% +a six tupo like this that all these +openings are accepted and these bits + + align:start position:0% +openings are accepted and these bits + + + align:start position:0% +openings are accepted and these bits +satisfy the gate + + align:start position:0% +satisfy the gate + + + align:start position:0% +satisfy the gate +and are valid opening with respect to + + align:start position:0% +and are valid opening with respect to + + + align:start position:0% +and are valid opening with respect to +which wires the wires that are defined + + align:start position:0% +which wires the wires that are defined + + + align:start position:0% +which wires the wires that are defined +by the gate so think of that you know we + + align:start position:0% +by the gate so think of that you know we + + + align:start position:0% +by the gate so think of that you know we +have this circuit C the gates are kind + + align:start position:0% +have this circuit C the gates are kind + + + align:start position:0% +have this circuit C the gates are kind +of uh numbered and for any Gates J we + + align:start position:0% +of uh numbered and for any Gates J we + + + align:start position:0% +of uh numbered and for any Gates J we +know there's we know the number of the + + align:start position:0% +know there's we know the number of the + + + align:start position:0% +know there's we know the number of the +input an output wire okay because it's + + align:start position:0% +input an output wire okay because it's + + + align:start position:0% +input an output wire okay because it's +this is uniform everything the circuit + + align:start position:0% +this is uniform everything the circuit + + + align:start position:0% +this is uniform everything the circuit +is uniform so for every gate J we + + align:start position:0% +is uniform so for every gate J we + + + align:start position:0% +is uniform so for every gate J we +corresponds to you know I know I yre I + + align:start position:0% +corresponds to you know I know I yre I + + + align:start position:0% +corresponds to you know I know I yre I +yre J and yre K yeah and so these + + align:start position:0% +yre J and yre K yeah and so these + + + align:start position:0% +yre J and yre K yeah and so these +openings should be with respect to y i y + + align:start position:0% +openings should be with respect to y i y + + + align:start position:0% +openings should be with respect to y i y +j and y k the same hash key for same + + align:start position:0% +j and y k the same hash key for same + + + align:start position:0% +j and y k the same hash key for same +hash key for all of them yeah because I + + align:start position:0% +hash key for all of them yeah because I + + + align:start position:0% +hash key for all of them yeah because I +used one hash key I mean it's one hash + + align:start position:0% +used one hash key I mean it's one hash + + + align:start position:0% +used one hash key I mean it's one hash +key that's binding and and allocations + + align:start position:0% +key that's binding and and allocations + + + align:start position:0% +key that's binding and and allocations +but I'm uh now I'm thinking just just + + align:start position:0% +but I'm uh now I'm thinking just just + + + align:start position:0% +but I'm uh now I'm thinking just just +one hash key that's binding how I + + align:start position:0% +one hash key that's binding how I + + + align:start position:0% +one hash key that's binding how I +construct it + + align:start position:0% +construct it + + + align:start position:0% +construct it +will abstract that for now but yeah I + + align:start position:0% +will abstract that for now but yeah I + + + align:start position:0% +will abstract that for now but yeah I +have one hash key that's binding on a + + align:start position:0% +have one hash key that's binding on a + + + align:start position:0% +have one hash key that's binding on a +location I hash all the values of the + + align:start position:0% +location I hash all the values of the + + + align:start position:0% +location I hash all the values of the +the W the values of all the wires to + + align:start position:0% +the W the values of all the wires to + + + align:start position:0% +the W the values of all the wires to +this specific hash key and then add a + + align:start position:0% +this specific hash key and then add a + + + align:start position:0% +this specific hash key and then add a +bar for any uh gate J that I have an + + align:start position:0% +bar for any uh gate J that I have an + + + align:start position:0% +bar for any uh gate J that I have an +opening for the input the two input + + align:start position:0% +opening for the input the two input + + + align:start position:0% +opening for the input the two input +children the output output uh um wire of + + align:start position:0% +children the output output uh um wire of + + + align:start position:0% +children the output output uh um wire of +gate J that satisfy the gate yeah only + + align:start position:0% +gate J that satisfy the gate yeah only + + + align:start position:0% +gate J that satisfy the gate yeah only +differ index itself so it's like one of + + align:start position:0% +differ index itself so it's like one of + + + align:start position:0% +differ index itself so it's like one of +the + + align:start position:0% +the + + + align:start position:0% +the +index yeah yeah yeah yeah good so you're + + align:start position:0% +index yeah yeah yeah yeah good so you're + + + align:start position:0% +index yeah yeah yeah yeah good so you're +saying where's J here where's + + align:start position:0% +saying where's J here where's + + + align:start position:0% +saying where's J here where's +J is that you're saying no more like + + align:start position:0% +J is that you're saying no more like + + + align:start position:0% +J is that you're saying no more like +like J star and XJ the only difference + + align:start position:0% +like J star and XJ the only difference + + + align:start position:0% +like J star and XJ the only difference +is J okay so this is an index kind of + + align:start position:0% +is J okay so this is an index kind of + + + align:start position:0% +is J okay so this is an index kind of +language yeah this note this is kind of + + align:start position:0% +language yeah this note this is kind of + + + align:start position:0% +language yeah this note this is kind of +it's that X1 X1 star X2 star are the + + align:start position:0% +it's that X1 X1 star X2 star are the + + + align:start position:0% +it's that X1 X1 star X2 star are the +same hash KV K one two 3 four up to K so + + align:start position:0% +same hash KV K one two 3 four up to K so + + + align:start position:0% +same hash KV K one two 3 four up to K so +it's kind of an index language we're + + align:start position:0% +it's kind of an index language we're + + + align:start position:0% +it's kind of an index language we're +going to get back to it when uh because + + align:start position:0% +going to get back to it when uh because + + + align:start position:0% +going to get back to it when uh because +we want the efficiency of V so we'll + + align:start position:0% +we want the efficiency of V so we'll + + + align:start position:0% +we want the efficiency of V so we'll +talk about that but + + align:start position:0% + + + + align:start position:0% + +yes any question about the the prover + + align:start position:0% +yes any question about the the prover + + + align:start position:0% +yes any question about the the prover +here + + align:start position:0% + + + + align:start position:0% + +okay so now the verifier what the + + align:start position:0% +okay so now the verifier what the + + + align:start position:0% +okay so now the verifier what the +verifier + + align:start position:0% +verifier + + + align:start position:0% +verifier +does is uh okay so now let's write the + + align:start position:0% +does is uh okay so now let's write the + + + align:start position:0% +does is uh okay so now let's write the +verifier + + align:start position:0% +verifier + + + align:start position:0% +verifier +somewhere oh that's sad I want to keep + + align:start position:0% +somewhere oh that's sad I want to keep + + + align:start position:0% +somewhere oh that's sad I want to keep +this okay if you don't mind we'll write + + align:start position:0% +this okay if you don't mind we'll write + + + align:start position:0% +this okay if you don't mind we'll write +the verifier + + align:start position:0% +the verifier + + + align:start position:0% +the verifier +here okay so what does the verifier do V + + align:start position:0% +here okay so what does the verifier do V + + + align:start position:0% +here okay so what does the verifier do V +takes his input a CRS which + + align:start position:0% +takes his input a CRS which + + + align:start position:0% +takes his input a CRS which +is hash key and CRS + + align:start position:0% + + + + align:start position:0% + +bar that's the CRS and it takes an + + align:start position:0% +bar that's the CRS and it takes an + + + align:start position:0% +bar that's the CRS and it takes an +instance X and a proof what is the proof + + align:start position:0% +instance X and a proof what is the proof + + + align:start position:0% +instance X and a proof what is the proof +a proof is a + + align:start position:0% + + + + align:start position:0% + +value and um a + + align:start position:0% +value and um a + + + align:start position:0% +value and um a +bar a hash value and a bar okay so the + + align:start position:0% +bar a hash value and a bar okay so the + + + align:start position:0% +bar a hash value and a bar okay so the +verifier he gets the CRS which is of + + align:start position:0% +verifier he gets the CRS which is of + + + align:start position:0% +verifier he gets the CRS which is of +this form he gets an input X and he gets + + align:start position:0% +this form he gets an input X and he gets + + + align:start position:0% +this form he gets an input X and he gets +snar a snar is oh did I say what did + + align:start position:0% +snar a snar is oh did I say what did + + + align:start position:0% +snar a snar is oh did I say what did +output sorry okay sorry compute + + align:start position:0% + + + + align:start position:0% + +output V and P + + align:start position:0% + + + + align:start position:0% + +bar so now he takes the The Snug which + + align:start position:0% +bar so now he takes the The Snug which + + + align:start position:0% +bar so now he takes the The Snug which +is a + + align:start position:0% +is a + + + align:start position:0% +is a +hash and uh and a bar + + align:start position:0% +hash and uh and a bar + + + align:start position:0% +hash and uh and a bar +and it just outputs + + align:start position:0% +and it just outputs + + + align:start position:0% +and it just outputs +one and + + align:start position:0% + + + + align:start position:0% + +output the output of V bar he accepts if + + align:start position:0% +output the output of V bar he accepts if + + + align:start position:0% +output the output of V bar he accepts if +and only if the bar is accepting what do + + align:start position:0% +and only if the bar is accepting what do + + + align:start position:0% +and only if the bar is accepting what do +I mean the bar V bar takes CRS + + align:start position:0% +I mean the bar V bar takes CRS + + + align:start position:0% +I mean the bar V bar takes CRS +bar and X1 star up to XK star which are + + align:start position:0% +bar and X1 star up to XK star which are + + + align:start position:0% +bar and X1 star up to XK star which are +essentially an index language + + align:start position:0% +essentially an index language + + + align:start position:0% +essentially an index language +corresponding to + + align:start position:0% +corresponding to + + + align:start position:0% +corresponding to +HK V + + align:start position:0% +HK V + + + align:start position:0% +HK V +and + + align:start position:0% + + + + align:start position:0% + +J so it + + align:start position:0% +J so it + + + align:start position:0% +J so it +accepts if and only if the bar is + + align:start position:0% + + + + align:start position:0% + +accepted that's the + + align:start position:0% + + + + align:start position:0% + +snar one thing I so again you a the + + align:start position:0% +snar one thing I so again you a the + + + align:start position:0% +snar one thing I so again you a the +again what is the snar in the CRS + + align:start position:0% +again what is the snar in the CRS + + + align:start position:0% +again what is the snar in the CRS +generated generation you generate a hash + + align:start position:0% +generated generation you generate a hash + + + align:start position:0% +generated generation you generate a hash +key for the sum extractable hash and you + + align:start position:0% +key for the sum extractable hash and you + + + align:start position:0% +key for the sum extractable hash and you +generate a CRS for the barg the + + align:start position:0% +generate a CRS for the barg the + + + align:start position:0% +generate a CRS for the barg the +prover computes the values of all the + + align:start position:0% +prover computes the values of all the + + + align:start position:0% +prover computes the values of all the +wires in the circuits hashes it using + + align:start position:0% +wires in the circuits hashes it using + + + align:start position:0% +wires in the circuits hashes it using +the hash key to generate a value a hash + + align:start position:0% +the hash key to generate a value a hash + + + align:start position:0% +the hash key to generate a value a hash +value V and then he proves he gives a + + align:start position:0% +value V and then he proves he gives a + + + align:start position:0% +value V and then he proves he gives a +bar that all the gates are satisfied + + align:start position:0% +bar that all the gates are satisfied + + + align:start position:0% +bar that all the gates are satisfied +namely for every gate he has an opening + + align:start position:0% +namely for every gate he has an opening + + + align:start position:0% +namely for every gate he has an opening +valid that's satisfi that respects the + + align:start position:0% +valid that's satisfi that respects the + + + align:start position:0% +valid that's satisfi that respects the +gate gate and that the upper gate is one + + align:start position:0% +gate gate and that the upper gate is one + + + align:start position:0% +gate gate and that the upper gate is one +that's another thing you also prove that + + align:start position:0% +that's another thing you also prove that + + + align:start position:0% +that's another thing you also prove that +in the B you also prove that the upper + + align:start position:0% +in the B you also prove that the upper + + + align:start position:0% +in the B you also prove that the upper +gate is one so for the upper gate you + + align:start position:0% +gate is one so for the upper gate you + + + align:start position:0% +gate is one so for the upper gate you +prove it respects namely you prove it's + + align:start position:0% +prove it respects namely you prove it's + + + align:start position:0% +prove it respects namely you prove it's +one + + align:start position:0% +one + + + align:start position:0% +one +um good so that's and and how do you + + align:start position:0% +um good so that's and and how do you + + + align:start position:0% +um good so that's and and how do you +verify you just verify the + + align:start position:0% +verify you just verify the + + + align:start position:0% +verify you just verify the +bar now here's one important thing to + + align:start position:0% +bar now here's one important thing to + + + align:start position:0% +bar now here's one important thing to +note this V bar takes his input the bar + + align:start position:0% +note this V bar takes his input the bar + + + align:start position:0% +note this V bar takes his input the bar +of length k k is like the number of + + align:start position:0% +of length k k is like the number of + + + align:start position:0% +of length k k is like the number of +wires in the circuit we do not want want + + align:start position:0% +wires in the circuit we do not want want + + + align:start position:0% +wires in the circuit we do not want want +the verifier to run in time K that would + + align:start position:0% +the verifier to run in time K that would + + + align:start position:0% +the verifier to run in time K that would +be the the size of the circuit no we + + align:start position:0% +be the the size of the circuit no we + + + align:start position:0% +be the the size of the circuit no we +want the verifier to be very + + align:start position:0% +want the verifier to be very + + + align:start position:0% +want the verifier to be very +efficient but that's but that's okay + + align:start position:0% +efficient but that's but that's okay + + + align:start position:0% +efficient but that's but that's okay +because he actually doesn't need to run + + align:start position:0% +because he actually doesn't need to run + + + align:start position:0% +because he actually doesn't need to run +in time K because actually it's an in + + align:start position:0% +in time K because actually it's an in + + + align:start position:0% +in time K because actually it's an in +it's what's called an index language + + align:start position:0% +it's what's called an index language + + + align:start position:0% +it's what's called an index language +namely X1 up to XK + + align:start position:0% +namely X1 up to XK + + + align:start position:0% +namely X1 up to XK +star essentially it's like an index on + + align:start position:0% +star essentially it's like an index on + + + align:start position:0% +star essentially it's like an index on +an Hash k and V so the the you can + + align:start position:0% +an Hash k and V so the the you can + + + align:start position:0% +an Hash k and V so the the you can +generate them kind of you can um Express + + align:start position:0% +generate them kind of you can um Express + + + align:start position:0% +generate them kind of you can um Express +them very + + align:start position:0% +them very + + + align:start position:0% +them very +succinctly right the you can you can + + align:start position:0% +succinctly right the you can you can + + + align:start position:0% +succinctly right the you can you can +express them by hash key V and all the + + align:start position:0% +express them by hash key V and all the + + + align:start position:0% +express them by hash key V and all the +index between one and K that's it so + + align:start position:0% +index between one and K that's it so + + + align:start position:0% +index between one and K that's it so +because they have a succinct + + align:start position:0% +because they have a succinct + + + align:start position:0% +because they have a succinct +representation the RM of the verifier + + align:start position:0% +representation the RM of the verifier + + + align:start position:0% +representation the RM of the verifier +only grows with hash key and V PO with + + align:start position:0% +only grows with hash key and V PO with + + + align:start position:0% +only grows with hash key and V PO with +hash and V he does not need to grow with + + align:start position:0% +hash and V he does not need to grow with + + + align:start position:0% +hash and V he does not need to grow with +K that's kind of the um efficiency + + align:start position:0% +K that's kind of the um efficiency + + + align:start position:0% +K that's kind of the um efficiency +property of index languages and that's + + align:start position:0% +property of index languages and that's + + + align:start position:0% +property of index languages and that's +very important without it we can't use + + align:start position:0% +very important without it we can't use + + + align:start position:0% +very important without it we can't use +it for the bar for the + + align:start position:0% +it for the bar for the + + + align:start position:0% +it for the bar for the +snar so the so in terms of efficiency if + + align:start position:0% +snar so the so in terms of efficiency if + + + align:start position:0% +snar so the so in terms of efficiency if +the bar has good efficiency and let's + + align:start position:0% +the bar has good efficiency and let's + + + align:start position:0% +the bar has good efficiency and let's +say the the dependence is poly log on K + + align:start position:0% +say the the dependence is poly log on K + + + align:start position:0% +say the the dependence is poly log on K +then the V is going to be so what what + + align:start position:0% +then the V is going to be so what what + + + align:start position:0% +then the V is going to be so what what +is the what's the the snar grows with v + + align:start position:0% +is the what's the the snar grows with v + + + align:start position:0% +is the what's the the snar grows with v +and with a bar proof the bar proof is + + align:start position:0% +and with a bar proof the bar proof is + + + align:start position:0% +and with a bar proof the bar proof is +very if it grows with poly + + align:start position:0% +very if it grows with poly + + + align:start position:0% +very if it grows with poly +logarithmically with K it's like poly + + align:start position:0% +logarithmically with K it's like poly + + + align:start position:0% +logarithmically with K it's like poly +log the circuit sign very + + align:start position:0% +log the circuit sign very + + + align:start position:0% +log the circuit sign very +efficient V grows with the number of + + align:start position:0% +efficient V grows with the number of + + + align:start position:0% +efficient V grows with the number of +indices we're binding on so it grows + + align:start position:0% +indices we're binding on so it grows + + + align:start position:0% +indices we're binding on so it grows +with L so okay grows with L we'll try to + + align:start position:0% +with L so okay grows with L we'll try to + + + align:start position:0% +with L so okay grows with L we'll try to +minimize L we ideally want L to be poly + + align:start position:0% +minimize L we ideally want L to be poly + + + align:start position:0% +minimize L we ideally want L to be poly +log K okay so that's what we want we'll + + align:start position:0% +log K okay so that's what we want we'll + + + align:start position:0% +log K okay so that's what we want we'll +see what we get but ideally this should + + align:start position:0% +see what we get but ideally this should + + + align:start position:0% +see what we get but ideally this should +be polylog K and the runtime of the + + align:start position:0% +be polylog K and the runtime of the + + + align:start position:0% +be polylog K and the runtime of the +verifier because it's an index language + + align:start position:0% +verifier because it's an index language + + + align:start position:0% +verifier because it's an index language +is also going to be poog K assuming uh + + align:start position:0% +is also going to be poog K assuming uh + + + align:start position:0% +is also going to be poog K assuming uh +a sorry uh and he needs to to um to + + align:start position:0% +a sorry uh and he needs to to um to + + + align:start position:0% +a sorry uh and he needs to to um to +uh he does run in time x because he also + + align:start position:0% +uh he does run in time x because he also + + + align:start position:0% +uh he does run in time x because he also +needs to check to check this Pi Bar is + + align:start position:0% +needs to check to check this Pi Bar is + + + align:start position:0% +needs to check to check this Pi Bar is +Pi Bar comma of X because when you check + + align:start position:0% +Pi Bar comma of X because when you check + + + align:start position:0% +Pi Bar comma of X because when you check +the validity of the of that each gate is + + align:start position:0% +the validity of the of that each gate is + + + align:start position:0% +the validity of the of that each gate is +satisfied the the gates in layer one + + align:start position:0% +satisfied the the gates in layer one + + + align:start position:0% +satisfied the the gates in layer one +depend on the on X so to the gates in + + align:start position:0% +depend on the on X so to the gates in + + + align:start position:0% +depend on the on X so to the gates in +layer one the input wires are x x i XJ + + align:start position:0% +layer one the input wires are x x i XJ + + + align:start position:0% +layer one the input wires are x x i XJ +so the bug needs to know X the verifier + + align:start position:0% +so the bug needs to know X the verifier + + + align:start position:0% +so the bug needs to know X the verifier +of course needs to know X but but uh + + align:start position:0% +of course needs to know X but but uh + + + align:start position:0% +of course needs to know X but but uh +that's it so he doesn't need to run in + + align:start position:0% +that's it so he doesn't need to run in + + + align:start position:0% +that's it so he doesn't need to run in +time linear in X but the bar itself s is + + align:start position:0% +time linear in X but the bar itself s is + + + align:start position:0% +time linear in X but the bar itself s is +very short so the The Snug is very short + + align:start position:0% +very short so the The Snug is very short + + + align:start position:0% +very short so the The Snug is very short +the verify of course run needs to run + + align:start position:0% +the verify of course run needs to run + + + align:start position:0% +the verify of course run needs to run +time x he needs to read the input but + + align:start position:0% +time x he needs to read the input but + + + align:start position:0% +time x he needs to read the input but +that's + + align:start position:0% +that's + + + align:start position:0% +that's +it okay so any + + align:start position:0% + + + + align:start position:0% + +questions okay so let's take a break a + + align:start position:0% +questions okay so let's take a break a + + + align:start position:0% +questions okay so let's take a break a +cookie break a fun break and let's start + + align:start position:0% +cookie break a fun break and let's start + + + align:start position:0% +cookie break a fun break and let's start +again like 10 minutes and then we'll + + align:start position:0% +again like 10 minutes and then we'll + + + align:start position:0% +again like 10 minutes and then we'll +talk about the analysis and when but + + align:start position:0% +talk about the analysis and when but + + + align:start position:0% +talk about the analysis and when but +this is all that's done we're done with + + align:start position:0% +this is all that's done we're done with + + + align:start position:0% +this is all that's done we're done with +the construction this is your snar okay + + align:start position:0% +the construction this is your snar okay + + + align:start position:0% +the construction this is your snar okay +and we built up to it here it is and + + align:start position:0% +and we built up to it here it is and + + + align:start position:0% +and we built up to it here it is and +then we'll analyze it uh after the break \ No newline at end of file diff --git a/oAFufZvbBb0.txt b/oAFufZvbBb0.txt new file mode 100644 index 0000000000000000000000000000000000000000..605caaedcdb7c5d5a335219945a1b99d4ea443f9 --- /dev/null +++ b/oAFufZvbBb0.txt @@ -0,0 +1,8131 @@ +align:start position:0% + +We have a a very exciting uh group of of + + align:start position:0% +We have a a very exciting uh group of of + + + align:start position:0% +We have a a very exciting uh group of of +people to talk to you this morning. And + + align:start position:0% +people to talk to you this morning. And + + + align:start position:0% +people to talk to you this morning. And +the way we structure this, as Steve + + align:start position:0% +the way we structure this, as Steve + + + align:start position:0% +the way we structure this, as Steve +said, is is I'm going to give each uh + + align:start position:0% +said, is is I'm going to give each uh + + + align:start position:0% +said, is is I'm going to give each uh +each person about 15 or 20 minutes to + + align:start position:0% +each person about 15 or 20 minutes to + + + align:start position:0% +each person about 15 or 20 minutes to +make their presentation and then we're + + align:start position:0% +make their presentation and then we're + + + align:start position:0% +make their presentation and then we're +going to reserve about 20 minutes at the + + align:start position:0% +going to reserve about 20 minutes at the + + + align:start position:0% +going to reserve about 20 minutes at the +end for questions. I ask that you hold + + align:start position:0% +end for questions. I ask that you hold + + + align:start position:0% +end for questions. I ask that you hold +your questions until until we finish, + + align:start position:0% +your questions until until we finish, + + + align:start position:0% +your questions until until we finish, +but we will uh then be up here as a + + align:start position:0% +but we will uh then be up here as a + + + align:start position:0% +but we will uh then be up here as a +panel to answer the questions. And the + + align:start position:0% +panel to answer the questions. And the + + + align:start position:0% +panel to answer the questions. And the +way we've got it structured is that um + + align:start position:0% +way we've got it structured is that um + + + align:start position:0% +way we've got it structured is that um +I'm going to start off and I'm going to + + align:start position:0% +I'm going to start off and I'm going to + + + align:start position:0% +I'm going to start off and I'm going to +talk about a few things that that we're + + align:start position:0% +talk about a few things that that we're + + + align:start position:0% +talk about a few things that that we're +doing at the University of Arkansas and + + align:start position:0% +doing at the University of Arkansas and + + + align:start position:0% +doing at the University of Arkansas and +some of the the holes that that we see + + align:start position:0% +some of the the holes that that we see + + + align:start position:0% +some of the the holes that that we see +that are out there that need to be + + align:start position:0% +that are out there that need to be + + + align:start position:0% +that are out there that need to be +filled. And uh then we have um Simon + + align:start position:0% +filled. And uh then we have um Simon + + + align:start position:0% +filled. And uh then we have um Simon +Langford from from Walmart. Um we have + + align:start position:0% +Langford from from Walmart. Um we have + + + align:start position:0% +Langford from from Walmart. Um we have +Terry Crawford from Publix and that's + + align:start position:0% +Terry Crawford from Publix and that's + + + align:start position:0% +Terry Crawford from Publix and that's +the the retailer side of things. Uh then + + align:start position:0% +the the retailer side of things. Uh then + + + align:start position:0% +the the retailer side of things. Uh then +we have Dick Canwell from PNG Gillette + + align:start position:0% +we have Dick Canwell from PNG Gillette + + + align:start position:0% +we have Dick Canwell from PNG Gillette +from the supplier perspective and we + + align:start position:0% +from the supplier perspective and we + + + align:start position:0% +from the supplier perspective and we +have Klaus Garbish from DHL from the + + align:start position:0% +have Klaus Garbish from DHL from the + + + align:start position:0% +have Klaus Garbish from DHL from the +logistics side. So we've we've tried to + + align:start position:0% +logistics side. So we've we've tried to + + + align:start position:0% +logistics side. So we've we've tried to +cover the supply chain with uh as much + + align:start position:0% +cover the supply chain with uh as much + + + align:start position:0% +cover the supply chain with uh as much +as possible with our panelists here and + + align:start position:0% +as possible with our panelists here and + + + align:start position:0% +as possible with our panelists here and +and then we'll we'll wrap up then with + + align:start position:0% +and then we'll we'll wrap up then with + + + align:start position:0% +and then we'll we'll wrap up then with +Brian Subberan from from + + align:start position:0% +Brian Subberan from from + + + align:start position:0% +Brian Subberan from from +MIT again. So we'll start with academic + + align:start position:0% +MIT again. So we'll start with academic + + + align:start position:0% +MIT again. So we'll start with academic +we'll end it with academic and and + + align:start position:0% +we'll end it with academic and and + + + align:start position:0% +we'll end it with academic and and +industry in between. So, uh, let's go + + align:start position:0% +industry in between. So, uh, let's go + + + align:start position:0% +industry in between. So, uh, let's go +ahead and get started. And again, + + align:start position:0% +ahead and get started. And again, + + + align:start position:0% +ahead and get started. And again, +welcome welcome to our panelist. And, + + align:start position:0% +welcome welcome to our panelist. And, + + + align:start position:0% +welcome welcome to our panelist. And, +um, I'll keep myself my my job is going + + align:start position:0% +um, I'll keep myself my my job is going + + + align:start position:0% +um, I'll keep myself my my job is going +to be timekeeper, so I'll keep myself on + + align:start position:0% +to be timekeeper, so I'll keep myself on + + + align:start position:0% +to be timekeeper, so I'll keep myself on +time here. Uh, I want to talk about what + + align:start position:0% +time here. Uh, I want to talk about what + + + align:start position:0% +time here. Uh, I want to talk about what +we're doing again at the at the + + align:start position:0% +we're doing again at the at the + + + align:start position:0% +we're doing again at the at the +University of Arkansas and then and to + + align:start position:0% +University of Arkansas and then and to + + + align:start position:0% +University of Arkansas and then and to +talk about some of the research + + align:start position:0% +talk about some of the research + + + align:start position:0% +talk about some of the research +areas. We we have research in several + + align:start position:0% +areas. We we have research in several + + + align:start position:0% +areas. We we have research in several +areas. I'm going to restrict it because + + align:start position:0% +areas. I'm going to restrict it because + + + align:start position:0% +areas. I'm going to restrict it because +of our topic here being supply chain to + + align:start position:0% +of our topic here being supply chain to + + + align:start position:0% +of our topic here being supply chain to +to those specific topics. But we are we + + align:start position:0% +to those specific topics. But we are we + + + align:start position:0% +to those specific topics. But we are we +are heavily involved in the at this + + align:start position:0% +are heavily involved in the at this + + + align:start position:0% +are heavily involved in the at this +point technology deployment. Uh we've + + align:start position:0% +point technology deployment. Uh we've + + + align:start position:0% +point technology deployment. Uh we've +got some groups that are looking at u + + align:start position:0% +got some groups that are looking at u + + + align:start position:0% +got some groups that are looking at u +developing some technology but but for + + align:start position:0% +developing some technology but but for + + + align:start position:0% +developing some technology but but for +the most part we are we're very heavy in + + align:start position:0% +the most part we are we're very heavy in + + + align:start position:0% +the most part we are we're very heavy in +in deploying that technology static + + align:start position:0% +in deploying that technology static + + + align:start position:0% +in deploying that technology static +versus uh mobile readers uh gen two uh + + align:start position:0% +versus uh mobile readers uh gen two uh + + + align:start position:0% +versus uh mobile readers uh gen two uh +those type of things. Uh we we've just + + align:start position:0% +those type of things. Uh we we've just + + + align:start position:0% +those type of things. Uh we we've just +our lab was just converted over and now + + align:start position:0% +our lab was just converted over and now + + + align:start position:0% +our lab was just converted over and now +was just telling Simon we uh we're now + + align:start position:0% +was just telling Simon we uh we're now + + + align:start position:0% +was just telling Simon we uh we're now +totally gen two uh no more gen one + + align:start position:0% +totally gen two uh no more gen one + + + align:start position:0% +totally gen two uh no more gen one +testing for us at this point. Um and + + align:start position:0% +testing for us at this point. Um and + + + align:start position:0% +testing for us at this point. Um and +that's really from the demands that + + align:start position:0% +that's really from the demands that + + + align:start position:0% +that's really from the demands that +we're seeing from from industry data + + align:start position:0% +we're seeing from from industry data + + + align:start position:0% +we're seeing from from industry data +analytics. I'll talk more about that in + + align:start position:0% +analytics. I'll talk more about that in + + + align:start position:0% +analytics. I'll talk more about that in +in depth making the business case. I'll + + align:start position:0% +in depth making the business case. I'll + + + align:start position:0% +in depth making the business case. I'll +talk more about that, but we're doing + + align:start position:0% +talk more about that, but we're doing + + + align:start position:0% +talk more about that, but we're doing +doing projects in middleware, open- + + align:start position:0% +doing projects in middleware, open- + + + align:start position:0% +doing projects in middleware, open- +source um development, uh lots of work + + align:start position:0% +source um development, uh lots of work + + + align:start position:0% +source um development, uh lots of work +around public policy, consumer reaction + + align:start position:0% +around public policy, consumer reaction + + + align:start position:0% +around public policy, consumer reaction +type issues, um animal ID. We've got a + + align:start position:0% +type issues, um animal ID. We've got a + + + align:start position:0% +type issues, um animal ID. We've got a +group in our a department uh and also + + align:start position:0% +group in our a department uh and also + + + align:start position:0% +group in our a department uh and also +with our close affiliation with our + + align:start position:0% +with our close affiliation with our + + + align:start position:0% +with our close affiliation with our +friends at Tyson down the street uh + + align:start position:0% +friends at Tyson down the street uh + + + align:start position:0% +friends at Tyson down the street uh +doing a lot of in animal ID trailer + + align:start position:0% +doing a lot of in animal ID trailer + + + align:start position:0% +doing a lot of in animal ID trailer +tracking load status uh trying to move + + align:start position:0% +tracking load status uh trying to move + + + align:start position:0% +tracking load status uh trying to move +more into the logistics area there and + + align:start position:0% +more into the logistics area there and + + + align:start position:0% +more into the logistics area there and +also as we move up the supply chain into + + align:start position:0% +also as we move up the supply chain into + + + align:start position:0% +also as we move up the supply chain into +manufacturing uh as well. Let me drill + + align:start position:0% +manufacturing uh as well. Let me drill + + + align:start position:0% +manufacturing uh as well. Let me drill +down to a couple of areas here and start + + align:start position:0% +down to a couple of areas here and start + + + align:start position:0% +down to a couple of areas here and start +off with with data analytics. And that's + + align:start position:0% +off with with data analytics. And that's + + + align:start position:0% +off with with data analytics. And that's +one area that we've spent a great deal + + align:start position:0% +one area that we've spent a great deal + + + align:start position:0% +one area that we've spent a great deal +of time uh and trying to look at what + + align:start position:0% +of time uh and trying to look at what + + + align:start position:0% +of time uh and trying to look at what +the data um really trying to tell us. + + align:start position:0% +the data um really trying to tell us. + + + align:start position:0% +the data um really trying to tell us. +And um we we were I was having a + + align:start position:0% +And um we we were I was having a + + + align:start position:0% +And um we we were I was having a +conversation with Jazelle this morning + + align:start position:0% +conversation with Jazelle this morning + + + align:start position:0% +conversation with Jazelle this morning +and uh a couple of conversations last + + align:start position:0% +and uh a couple of conversations last + + + align:start position:0% +and uh a couple of conversations last +night and that's an area that really + + align:start position:0% +night and that's an area that really + + + align:start position:0% +night and that's an area that really +needs a lot of work. Uh you know, we're + + align:start position:0% +needs a lot of work. Uh you know, we're + + + align:start position:0% +needs a lot of work. Uh you know, we're +getting the technology in place. The + + align:start position:0% +getting the technology in place. The + + + align:start position:0% +getting the technology in place. The +technology will come along. We've got a + + align:start position:0% +technology will come along. We've got a + + + align:start position:0% +technology will come along. We've got a +we've got a lot of things we can do + + align:start position:0% +we've got a lot of things we can do + + + align:start position:0% +we've got a lot of things we can do +there, but it's but it's about creating + + align:start position:0% +there, but it's but it's about creating + + + align:start position:0% +there, but it's but it's about creating +that data and then turning that data + + align:start position:0% +that data and then turning that data + + + align:start position:0% +that data and then turning that data +into business value. And so that data is + + align:start position:0% +into business value. And so that data is + + + align:start position:0% +into business value. And so that data is +a very very very important piece and uh + + align:start position:0% +a very very very important piece and uh + + + align:start position:0% +a very very very important piece and uh +you know we we first look at this idea + + align:start position:0% +you know we we first look at this idea + + + align:start position:0% +you know we we first look at this idea +of of the 100% read rates and we've + + align:start position:0% +of of the 100% read rates and we've + + + align:start position:0% +of of the 100% read rates and we've +we've heard all kinds of things about + + align:start position:0% +we've heard all kinds of things about + + + align:start position:0% +we've heard all kinds of things about +we've got to see 100% of those read + + align:start position:0% +we've got to see 100% of those read + + + align:start position:0% +we've got to see 100% of those read +rates for it to make sense. And it + + align:start position:0% +rates for it to make sense. And it + + + align:start position:0% +rates for it to make sense. And it +really doesn't. You know we there's an + + align:start position:0% +really doesn't. You know we there's an + + + align:start position:0% +really doesn't. You know we there's an +implicit read versus an explicit read. + + align:start position:0% +implicit read versus an explicit read. + + + align:start position:0% +implicit read versus an explicit read. +Yeah. Did you see it or can you imply + + align:start position:0% +Yeah. Did you see it or can you imply + + + align:start position:0% +Yeah. Did you see it or can you imply +that if it went from point A to point C + + align:start position:0% +that if it went from point A to point C + + + align:start position:0% +that if it went from point A to point C +that it went past point B? And um Sanjay + + align:start position:0% +that it went past point B? And um Sanjay + + + align:start position:0% +that it went past point B? And um Sanjay +talked about yesterday the idea of of + + align:start position:0% +talked about yesterday the idea of of + + + align:start position:0% +talked about yesterday the idea of of +this phantom inventory. If you were to + + align:start position:0% +this phantom inventory. If you were to + + + align:start position:0% +this phantom inventory. If you were to +miss it, that's extremely important. + + align:start position:0% +miss it, that's extremely important. + + + align:start position:0% +miss it, that's extremely important. +Obviously, if if you're not going to get + + align:start position:0% +Obviously, if if you're not going to get + + + align:start position:0% +Obviously, if if you're not going to get +100% reads, can you infer those 100% + + align:start position:0% +100% reads, can you infer those 100% + + + align:start position:0% +100% reads, can you infer those 100% +reads or how can you get that? And I + + align:start position:0% +reads or how can you get that? And I + + + align:start position:0% +reads or how can you get that? And I +think that's going to be very important + + align:start position:0% +think that's going to be very important + + + align:start position:0% +think that's going to be very important +as we as we go on that we when we reach + + align:start position:0% +as we as we go on that we when we reach + + + align:start position:0% +as we as we go on that we when we reach +this 100% read again whether it's + + align:start position:0% +this 100% read again whether it's + + + align:start position:0% +this 100% read again whether it's +implicit or explicit. You've got to be + + align:start position:0% +implicit or explicit. You've got to be + + + align:start position:0% +implicit or explicit. You've got to be +able to draw some inferences from where + + align:start position:0% +able to draw some inferences from where + + + align:start position:0% +able to draw some inferences from where +you saw that uh the data at this point + + align:start position:0% +you saw that uh the data at this point + + + align:start position:0% +you saw that uh the data at this point +is is very noisy. Uh and those of you in + + align:start position:0% +is is very noisy. Uh and those of you in + + + align:start position:0% +is is very noisy. Uh and those of you in +the room have seen the the data you know + + align:start position:0% +the room have seen the the data you know + + + align:start position:0% +the room have seen the the data you know +there there's there's a there's a lot of + + align:start position:0% +there there's there's a there's a lot of + + + align:start position:0% +there there's there's a there's a lot of +noise in that data. You know you may + + align:start position:0% +noise in that data. You know you may + + + align:start position:0% +noise in that data. You know you may +have uh hundreds of reads at a + + align:start position:0% +have uh hundreds of reads at a + + + align:start position:0% +have uh hundreds of reads at a +particular reader. maybe maybe was + + align:start position:0% +particular reader. maybe maybe was + + + align:start position:0% +particular reader. maybe maybe was +sitting near the reader and moving in + + align:start position:0% +sitting near the reader and moving in + + + align:start position:0% +sitting near the reader and moving in +and out of the field or maybe it passed + + align:start position:0% +and out of the field or maybe it passed + + + align:start position:0% +and out of the field or maybe it passed +back and forth or as the forklift was + + align:start position:0% +back and forth or as the forklift was + + + align:start position:0% +back and forth or as the forklift was +pulling it down through by the dock + + align:start position:0% +pulling it down through by the dock + + + align:start position:0% +pulling it down through by the dock +doors, it was reading at every dock + + align:start position:0% +doors, it was reading at every dock + + + align:start position:0% +doors, it was reading at every dock +door. There's a lot of noise there and + + align:start position:0% +door. There's a lot of noise there and + + + align:start position:0% +door. There's a lot of noise there and +and you know, we've we've did um early + + align:start position:0% +and you know, we've we've did um early + + + align:start position:0% +and you know, we've we've did um early +on quite a bit of work in in using um + + align:start position:0% +on quite a bit of work in in using um + + + align:start position:0% +on quite a bit of work in in using um +such things as neural networks to try to + + align:start position:0% +such things as neural networks to try to + + + align:start position:0% +such things as neural networks to try to +predict when something might be late or + + align:start position:0% +predict when something might be late or + + + align:start position:0% +predict when something might be late or +when it's outside of its its uh uh + + align:start position:0% +when it's outside of its its uh uh + + + align:start position:0% +when it's outside of its its uh uh +normal schedule or using such things as + + align:start position:0% +normal schedule or using such things as + + + align:start position:0% +normal schedule or using such things as +genetic algorithms to try to pull out + + align:start position:0% +genetic algorithms to try to pull out + + + align:start position:0% +genetic algorithms to try to pull out +those patterns in the data. and the the + + align:start position:0% +those patterns in the data. and the the + + + align:start position:0% +those patterns in the data. and the the +data is just very noisy. And we can + + align:start position:0% +data is just very noisy. And we can + + + align:start position:0% +data is just very noisy. And we can +artificially take that data and create + + align:start position:0% +artificially take that data and create + + + align:start position:0% +artificially take that data and create +some good models, but at this point we + + align:start position:0% +some good models, but at this point we + + + align:start position:0% +some good models, but at this point we +haven't been that successful in creating + + align:start position:0% +haven't been that successful in creating + + + align:start position:0% +haven't been that successful in creating +good models with the data as it is. Data + + align:start position:0% +good models with the data as it is. Data + + + align:start position:0% +good models with the data as it is. Data +has got to get cleaner. We got to find a + + align:start position:0% +has got to get cleaner. We got to find a + + + align:start position:0% +has got to get cleaner. We got to find a +way to to clean that data up. And one of + + align:start position:0% +way to to clean that data up. And one of + + + align:start position:0% +way to to clean that data up. And one of +those starts with business rules for + + align:start position:0% +those starts with business rules for + + + align:start position:0% +those starts with business rules for +interpretation. Uh I really feel that + + align:start position:0% +interpretation. Uh I really feel that + + + align:start position:0% +interpretation. Uh I really feel that +we've got to have and there's going to + + align:start position:0% +we've got to have and there's going to + + + align:start position:0% +we've got to have and there's going to +be multiple levels of these. There's + + align:start position:0% +be multiple levels of these. There's + + + align:start position:0% +be multiple levels of these. There's +going to be mo business rules that help + + align:start position:0% +going to be mo business rules that help + + + align:start position:0% +going to be mo business rules that help +us decipher what's a what what was a + + align:start position:0% +us decipher what's a what what was a + + + align:start position:0% +us decipher what's a what what was a +good read, what was a bad read, how do + + align:start position:0% +good read, what was a bad read, how do + + + align:start position:0% +good read, what was a bad read, how do +we make that implicit read then if it's + + align:start position:0% +we make that implicit read then if it's + + + align:start position:0% +we make that implicit read then if it's +not there. And unfortunately, these + + align:start position:0% +not there. And unfortunately, these + + + align:start position:0% +not there. And unfortunately, these +business rules, I think there's going to + + align:start position:0% +business rules, I think there's going to + + + align:start position:0% +business rules, I think there's going to +be some that are global in nature, but + + align:start position:0% +be some that are global in nature, but + + + align:start position:0% +be some that are global in nature, but +then there's going to be some that vary + + align:start position:0% +then there's going to be some that vary + + + align:start position:0% +then there's going to be some that vary +by industry. There's going to be some + + align:start position:0% +by industry. There's going to be some + + + align:start position:0% +by industry. There's going to be some +then that are going to be specific to + + align:start position:0% +then that are going to be specific to + + + align:start position:0% +then that are going to be specific to +companies. And we've got to have some + + align:start position:0% +companies. And we've got to have some + + + align:start position:0% +companies. And we've got to have some +type of architecture, data architecture + + align:start position:0% +type of architecture, data architecture + + + align:start position:0% +type of architecture, data architecture +that allows us to to specify those + + align:start position:0% +that allows us to to specify those + + + align:start position:0% +that allows us to to specify those +business rules all the way down, maybe + + align:start position:0% +business rules all the way down, maybe + + + align:start position:0% +business rules all the way down, maybe +even to a product level. I'm not sure + + align:start position:0% +even to a product level. I'm not sure + + + align:start position:0% +even to a product level. I'm not sure +what that architecture looks like yet. + + align:start position:0% +what that architecture looks like yet. + + + align:start position:0% +what that architecture looks like yet. +We're still trying to conceptualize what + + align:start position:0% +We're still trying to conceptualize what + + + align:start position:0% +We're still trying to conceptualize what +that thing is, but we've got to be able + + align:start position:0% +that thing is, but we've got to be able + + + align:start position:0% +that thing is, but we've got to be able +to to do a better job of of um + + align:start position:0% +to to do a better job of of um + + + align:start position:0% +to to do a better job of of um +interpreting that data. uh Sanjay + + align:start position:0% +interpreting that data. uh Sanjay + + + align:start position:0% +interpreting that data. uh Sanjay +mentioned yesterday the idea of control + + align:start position:0% +mentioned yesterday the idea of control + + + align:start position:0% +mentioned yesterday the idea of control +charts and I think that's going to be + + align:start position:0% +charts and I think that's going to be + + + align:start position:0% +charts and I think that's going to be +important is once we can start + + align:start position:0% +important is once we can start + + + align:start position:0% +important is once we can start +establishing these patterns and + + align:start position:0% +establishing these patterns and + + + align:start position:0% +establishing these patterns and +establishing what these these uh + + align:start position:0% +establishing what these these uh + + + align:start position:0% +establishing what these these uh +products should be doing then we can use + + align:start position:0% +products should be doing then we can use + + + align:start position:0% +products should be doing then we can use +this to to help us determine when things + + align:start position:0% +this to to help us determine when things + + + align:start position:0% +this to to help us determine when things +aren't operating properly um you know + + align:start position:0% +aren't operating properly um you know + + + align:start position:0% +aren't operating properly um you know +the idea of how much uh data will RFID + + align:start position:0% +the idea of how much uh data will RFID + + + align:start position:0% +the idea of how much uh data will RFID +generate you know there's been a lot of + + align:start position:0% +generate you know there's been a lot of + + + align:start position:0% +generate you know there's been a lot of +speculation about the the terabytes of + + align:start position:0% +speculation about the the terabytes of + + + align:start position:0% +speculation about the the terabytes of +data that will be generated and again + + align:start position:0% +data that will be generated and again + + + align:start position:0% +data that will be generated and again +that goes back to you know once we can + + align:start position:0% +that goes back to you know once we can + + + align:start position:0% +that goes back to you know once we can +get this data filtered and cleansed and + + align:start position:0% +get this data filtered and cleansed and + + + align:start position:0% +get this data filtered and cleansed and +and worked on I don't think it's going + + align:start position:0% +and worked on I don't think it's going + + + align:start position:0% +and worked on I don't think it's going +going to be that much and it's not the + + align:start position:0% +going to be that much and it's not the + + + align:start position:0% +going to be that much and it's not the +quantity so much as it is the quality of + + align:start position:0% +quantity so much as it is the quality of + + + align:start position:0% +quantity so much as it is the quality of +the data that's going to matter. You + + align:start position:0% +the data that's going to matter. You + + + align:start position:0% +the data that's going to matter. You +know, storage is cheap, but it's it's + + align:start position:0% +know, storage is cheap, but it's it's + + + align:start position:0% +know, storage is cheap, but it's it's +really extracting that quality. Um, and + + align:start position:0% +really extracting that quality. Um, and + + + align:start position:0% +really extracting that quality. Um, and +a couple issues that were mentioned + + align:start position:0% +a couple issues that were mentioned + + + align:start position:0% +a couple issues that were mentioned +yesterday, it's going to be extremely + + align:start position:0% +yesterday, it's going to be extremely + + + align:start position:0% +yesterday, it's going to be extremely +important data consistency. + + align:start position:0% +important data consistency. + + + align:start position:0% +important data consistency. +uh you know Walmart provides data via + + align:start position:0% +uh you know Walmart provides data via + + + align:start position:0% +uh you know Walmart provides data via +their retail link system and uh you know + + align:start position:0% +their retail link system and uh you know + + + align:start position:0% +their retail link system and uh you know +Target has their own system and Kmart + + align:start position:0% +Target has their own system and Kmart + + + align:start position:0% +Target has their own system and Kmart +has their own system and I know that uh + + align:start position:0% +has their own system and I know that uh + + + align:start position:0% +has their own system and I know that uh +I haven't talked to Simon uh yet but I + + align:start position:0% +I haven't talked to Simon uh yet but I + + + align:start position:0% +I haven't talked to Simon uh yet but I +know that I saw something in the in the + + align:start position:0% +know that I saw something in the in the + + + align:start position:0% +know that I saw something in the in the +news about Target and Walmart working on + + align:start position:0% +news about Target and Walmart working on + + + align:start position:0% +news about Target and Walmart working on +a program where there might be some some + + align:start position:0% +a program where there might be some some + + + align:start position:0% +a program where there might be some some +um efforts to make this data more + + align:start position:0% +um efforts to make this data more + + + align:start position:0% +um efforts to make this data more +consistent. It has to be that way. I + + align:start position:0% +consistent. It has to be that way. I + + + align:start position:0% +consistent. It has to be that way. I +mean we can't have every retailer with + + align:start position:0% +mean we can't have every retailer with + + + align:start position:0% +mean we can't have every retailer with +their own data format for this thing to + + align:start position:0% +their own data format for this thing to + + + align:start position:0% +their own data format for this thing to +work and same thing goes for suppliers. + + align:start position:0% +work and same thing goes for suppliers. + + + align:start position:0% +work and same thing goes for suppliers. +And then of course data integration into + + align:start position:0% +And then of course data integration into + + + align:start position:0% +And then of course data integration into +one's own own organization. I think + + align:start position:0% +one's own own organization. I think + + + align:start position:0% +one's own own organization. I think +we've got a lot of work there into + + align:start position:0% +we've got a lot of work there into + + + align:start position:0% +we've got a lot of work there into +pulling those into the enterprise + + align:start position:0% +pulling those into the enterprise + + + align:start position:0% +pulling those into the enterprise +systems that we have in place. And again + + align:start position:0% +systems that we have in place. And again + + + align:start position:0% +systems that we have in place. And again +with those things, you know, if you pull + + align:start position:0% +with those things, you know, if you pull + + + align:start position:0% +with those things, you know, if you pull +in in noisy or dirty data, uh it's it's + + align:start position:0% +in in noisy or dirty data, uh it's it's + + + align:start position:0% +in in noisy or dirty data, uh it's it's +very bad. So along the bottom you see + + align:start position:0% +very bad. So along the bottom you see + + + align:start position:0% +very bad. So along the bottom you see +there the idea of filter and cleanse, + + align:start position:0% +there the idea of filter and cleanse, + + + align:start position:0% +there the idea of filter and cleanse, +integrate, interpret and understand. + + align:start position:0% +integrate, interpret and understand. + + + align:start position:0% +integrate, interpret and understand. +We've got to move toward that model of + + align:start position:0% +We've got to move toward that model of + + + align:start position:0% +We've got to move toward that model of +filtering that data, cleansing that + + align:start position:0% +filtering that data, cleansing that + + + align:start position:0% +filtering that data, cleansing that +data, integrating with what we have, + + align:start position:0% +data, integrating with what we have, + + + align:start position:0% +data, integrating with what we have, +interpreting what it means and + + align:start position:0% +interpreting what it means and + + + align:start position:0% +interpreting what it means and +understanding. And that then will lead + + align:start position:0% +understanding. And that then will lead + + + align:start position:0% +understanding. And that then will lead +to action based upon that + + align:start position:0% +to action based upon that + + + align:start position:0% +to action based upon that +data. Now making the business case, we + + align:start position:0% +data. Now making the business case, we + + + align:start position:0% +data. Now making the business case, we +could we could spend the rest of the day + + align:start position:0% +could we could spend the rest of the day + + + align:start position:0% +could we could spend the rest of the day +talking about this this area and the + + align:start position:0% +talking about this this area and the + + + align:start position:0% +talking about this this area and the +opportunities that lie within and we had + + align:start position:0% +opportunities that lie within and we had + + + align:start position:0% +opportunities that lie within and we had +some questions yesterday. So, so in in + + align:start position:0% +some questions yesterday. So, so in in + + + align:start position:0% +some questions yesterday. So, so in in +the interest of just keeping it brief, + + align:start position:0% +the interest of just keeping it brief, + + + align:start position:0% +the interest of just keeping it brief, +what I've done is I want to throw out a + + align:start position:0% +what I've done is I want to throw out a + + + align:start position:0% +what I've done is I want to throw out a +couple of things just for you to think + + align:start position:0% +couple of things just for you to think + + + align:start position:0% +couple of things just for you to think +about and and again this is necessarily + + align:start position:0% +about and and again this is necessarily + + + align:start position:0% +about and and again this is necessarily +very narrow so that you can understand + + align:start position:0% +very narrow so that you can understand + + + align:start position:0% +very narrow so that you can understand +the scope at which which we could look + + align:start position:0% +the scope at which which we could look + + + align:start position:0% +the scope at which which we could look +at this. When we look at RFID, we can we + + align:start position:0% +at this. When we look at RFID, we can we + + + align:start position:0% +at this. When we look at RFID, we can we +can view this as an incremental + + align:start position:0% +can view this as an incremental + + + align:start position:0% +can view this as an incremental +technology. We can go in and we can + + align:start position:0% +technology. We can go in and we can + + + align:start position:0% +technology. We can go in and we can +tweak what's already there. Okay. Now, + + align:start position:0% +tweak what's already there. Okay. Now, + + + align:start position:0% +tweak what's already there. Okay. Now, +I'm going to I'm going to kind of look + + align:start position:0% +I'm going to I'm going to kind of look + + + align:start position:0% +I'm going to I'm going to kind of look +at, you know, primarily the store level, + + align:start position:0% +at, you know, primarily the store level, + + + align:start position:0% +at, you know, primarily the store level, +maybe a little bit at the DC level. But + + align:start position:0% +maybe a little bit at the DC level. But + + + align:start position:0% +maybe a little bit at the DC level. But +one thing we could do is say, "All + + align:start position:0% +one thing we could do is say, "All + + + align:start position:0% +one thing we could do is say, "All +right, we'll take RFID and it will just + + align:start position:0% +right, we'll take RFID and it will just + + + align:start position:0% +right, we'll take RFID and it will just +we we'll we'll just use it to make our + + align:start position:0% +we we'll we'll just use it to make our + + + align:start position:0% +we we'll we'll just use it to make our +process a little faster, a little more + + align:start position:0% +process a little faster, a little more + + + align:start position:0% +process a little faster, a little more +efficient, or we'll use it to to make + + align:start position:0% +efficient, or we'll use it to to make + + + align:start position:0% +efficient, or we'll use it to to make +our process a little better. Maybe our + + align:start position:0% +our process a little better. Maybe our + + + align:start position:0% +our process a little better. Maybe our +process isn't broke, it's it's just bent + + align:start position:0% +process isn't broke, it's it's just bent + + + align:start position:0% +process isn't broke, it's it's just bent +a little bit, and we'll use it to just + + align:start position:0% +a little bit, and we'll use it to just + + + align:start position:0% +a little bit, and we'll use it to just +tweak it." Okay, very incremental. We're + + align:start position:0% +tweak it." Okay, very incremental. We're + + + align:start position:0% +tweak it." Okay, very incremental. We're +not we're not radically changing + + align:start position:0% +not we're not radically changing + + + align:start position:0% +not we're not radically changing +anything. So I I just gave some examples + + align:start position:0% +anything. So I I just gave some examples + + + align:start position:0% +anything. So I I just gave some examples +there under the heading of process + + align:start position:0% +there under the heading of process + + + align:start position:0% +there under the heading of process +efficiencies for example promotions you + + align:start position:0% +efficiencies for example promotions you + + + align:start position:0% +efficiencies for example promotions you +know we we may be good at promotions but + + align:start position:0% +know we we may be good at promotions but + + + align:start position:0% +know we we may be good at promotions but +if we don't get it out to the to the + + align:start position:0% +if we don't get it out to the to the + + + align:start position:0% +if we don't get it out to the to the +shelf in a timely manner doesn't matter. + + align:start position:0% +shelf in a timely manner doesn't matter. + + + align:start position:0% +shelf in a timely manner doesn't matter. +So, you know, we can use RFID there. And + + align:start position:0% +So, you know, we can use RFID there. And + + + align:start position:0% +So, you know, we can use RFID there. And +I think there's been some, you know, you + + align:start position:0% +I think there's been some, you know, you + + + align:start position:0% +I think there's been some, you know, you +you probably have all seen this, the + + align:start position:0% +you probably have all seen this, the + + + align:start position:0% +you probably have all seen this, the +early studies. I know Gillette uh + + align:start position:0% +early studies. I know Gillette uh + + + align:start position:0% +early studies. I know Gillette uh +released some data from a study they did + + align:start position:0% +released some data from a study they did + + + align:start position:0% +released some data from a study they did +um working with MIT on on some uh + + align:start position:0% +um working with MIT on on some uh + + + align:start position:0% +um working with MIT on on some uh +opportunities for improvements just + + align:start position:0% +opportunities for improvements just + + + align:start position:0% +opportunities for improvements just +based upon promotions. Uh out of stocks + + align:start position:0% +based upon promotions. Uh out of stocks + + + align:start position:0% +based upon promotions. Uh out of stocks +is another one of those. Again, getting + + align:start position:0% +is another one of those. Again, getting + + + align:start position:0% +is another one of those. Again, getting +it to the shelf when the when the + + align:start position:0% +it to the shelf when the when the + + + align:start position:0% +it to the shelf when the when the +customer wants it in a timely manner. + + align:start position:0% +customer wants it in a timely manner. + + + align:start position:0% +customer wants it in a timely manner. +So, just speeding up that process that's + + align:start position:0% +So, just speeding up that process that's + + + align:start position:0% +So, just speeding up that process that's +already in place. We can also use it + + align:start position:0% +already in place. We can also use it + + + align:start position:0% +already in place. We can also use it +incrementally to to uh fix a process or + + align:start position:0% +incrementally to to uh fix a process or + + + align:start position:0% +incrementally to to uh fix a process or +or make that process a little better. + + align:start position:0% +or make that process a little better. + + + align:start position:0% +or make that process a little better. +Product rotation. Okay, we know how to + + align:start position:0% +Product rotation. Okay, we know how to + + + align:start position:0% +Product rotation. Okay, we know how to +do product rotation. It's not a matter + + align:start position:0% +do product rotation. It's not a matter + + + align:start position:0% +do product rotation. It's not a matter +of timeliness. It's a matter of are we + + align:start position:0% +of timeliness. It's a matter of are we + + + align:start position:0% +of timeliness. It's a matter of are we +doing it correctly? Well, with RFID, we + + align:start position:0% +doing it correctly? Well, with RFID, we + + + align:start position:0% +doing it correctly? Well, with RFID, we +know what's coming in, what's going out. + + align:start position:0% +know what's coming in, what's going out. + + + align:start position:0% +know what's coming in, what's going out. +We can maybe fix some of those problems. + + align:start position:0% +We can maybe fix some of those problems. + + + align:start position:0% +We can maybe fix some of those problems. +Uh better use of merchandisers. Instead + + align:start position:0% +Uh better use of merchandisers. Instead + + + align:start position:0% +Uh better use of merchandisers. Instead +of sending merchandisers to various + + align:start position:0% +of sending merchandisers to various + + + align:start position:0% +of sending merchandisers to various +stores uh just at random or or better or + + align:start position:0% +stores uh just at random or or better or + + + align:start position:0% +stores uh just at random or or better or +worse yet just on a set schedule, maybe + + align:start position:0% +worse yet just on a set schedule, maybe + + + align:start position:0% +worse yet just on a set schedule, maybe +target those merchandisers to where we + + align:start position:0% +target those merchandisers to where we + + + align:start position:0% +target those merchandisers to where we +see product in the back room or when we + + align:start position:0% +see product in the back room or when we + + + align:start position:0% +see product in the back room or when we +see an out of stock event based upon uh + + align:start position:0% +see an out of stock event based upon uh + + + align:start position:0% +see an out of stock event based upon uh +the RFID data. Target those + + align:start position:0% +the RFID data. Target those + + + align:start position:0% +the RFID data. Target those +merchandisers again improving that + + align:start position:0% +merchandisers again improving that + + + align:start position:0% +merchandisers again improving that +process. uh the the manual orders that + + align:start position:0% +process. uh the the manual orders that + + + align:start position:0% +process. uh the the manual orders that +um for example that that Walmart is um + + align:start position:0% +um for example that that Walmart is um + + + align:start position:0% +um for example that that Walmart is um +is doing with with RFID trying to + + align:start position:0% +is doing with with RFID trying to + + + align:start position:0% +is doing with with RFID trying to +restrict those those overrides of those + + align:start position:0% +restrict those those overrides of those + + + align:start position:0% +restrict those those overrides of those +manual orders when we know that + + align:start position:0% +manual orders when we know that + + + align:start position:0% +manual orders when we know that +something's in the back room um + + align:start position:0% +something's in the back room um + + + align:start position:0% +something's in the back room um +electronic proof of delivery um at the + + align:start position:0% +electronic proof of delivery um at the + + + align:start position:0% +electronic proof of delivery um at the +at the DC for example trying to fix that + + align:start position:0% +at the DC for example trying to fix that + + + align:start position:0% +at the DC for example trying to fix that +process where we really see what's + + align:start position:0% +process where we really see what's + + + align:start position:0% +process where we really see what's +coming into the DC and then also I'll + + align:start position:0% +coming into the DC and then also I'll + + + align:start position:0% +coming into the DC and then also I'll +put out a stocks under the idea + + align:start position:0% +put out a stocks under the idea + + + align:start position:0% +put out a stocks under the idea +effectiveness of of uh not only getting + + align:start position:0% +effectiveness of of uh not only getting + + + align:start position:0% +effectiveness of of uh not only getting +out there as a as as an efficiency of + + align:start position:0% +out there as a as as an efficiency of + + + align:start position:0% +out there as a as as an efficiency of +getting out there in a time but also + + align:start position:0% +getting out there in a time but also + + + align:start position:0% +getting out there in a time but also +improving that process. Um there was + + align:start position:0% +improving that process. Um there was + + + align:start position:0% +improving that process. Um there was +there was some data released earlier uh + + align:start position:0% +there was some data released earlier uh + + + align:start position:0% +there was some data released earlier uh +in 2005 that that from Walmart suggested + + align:start position:0% +in 2005 that that from Walmart suggested + + + align:start position:0% +in 2005 that that from Walmart suggested +that you know one out of 12 products was + + align:start position:0% +that you know one out of 12 products was + + + align:start position:0% +that you know one out of 12 products was +actually making it uh from the from the + + align:start position:0% +actually making it uh from the from the + + + align:start position:0% +actually making it uh from the from the +pick list to the shelf and and Simon you + + align:start position:0% +pick list to the shelf and and Simon you + + + align:start position:0% +pick list to the shelf and and Simon you +may have to correct that stat if it's + + align:start position:0% +may have to correct that stat if it's + + + align:start position:0% +may have to correct that stat if it's +not entirely correct but something you + + align:start position:0% +not entirely correct but something you + + + align:start position:0% +not entirely correct but something you +know on a busy Saturday you know by the + + align:start position:0% +know on a busy Saturday you know by the + + + align:start position:0% +know on a busy Saturday you know by the +time it got on the pick list and then + + align:start position:0% +time it got on the pick list and then + + + align:start position:0% +time it got on the pick list and then +got to shelf one out of 12. Well, that + + align:start position:0% +got to shelf one out of 12. Well, that + + + align:start position:0% +got to shelf one out of 12. Well, that +that process can be helped with + + align:start position:0% +that process can be helped with + + + align:start position:0% +that process can be helped with +RFID. Now again, so if you view it as an + + align:start position:0% +RFID. Now again, so if you view it as an + + + align:start position:0% +RFID. Now again, so if you view it as an +incremental technology and some + + align:start position:0% +incremental technology and some + + + align:start position:0% +incremental technology and some +companies are doing that, they look at + + align:start position:0% +companies are doing that, they look at + + + align:start position:0% +companies are doing that, they look at +it and they say, "Okay, RFID is just + + align:start position:0% +it and they say, "Okay, RFID is just + + + align:start position:0% +it and they say, "Okay, RFID is just +going to help us improve the speed of + + align:start position:0% +going to help us improve the speed of + + + align:start position:0% +going to help us improve the speed of +our process or help us tweak our process + + align:start position:0% +our process or help us tweak our process + + + align:start position:0% +our process or help us tweak our process +a little bit." Others are viewing it as + + align:start position:0% +a little bit." Others are viewing it as + + + align:start position:0% +a little bit." Others are viewing it as +more as a radical or disruptive + + align:start position:0% +more as a radical or disruptive + + + align:start position:0% +more as a radical or disruptive +technology. And and that is giving us an + + align:start position:0% +technology. And and that is giving us an + + + align:start position:0% +technology. And and that is giving us an +opportunity to use RFID as a process + + align:start position:0% +opportunity to use RFID as a process + + + align:start position:0% +opportunity to use RFID as a process +enabler. Let's go in and and create new + + align:start position:0% +enabler. Let's go in and and create new + + + align:start position:0% +enabler. Let's go in and and create new +ways of doing business that were never + + align:start position:0% +ways of doing business that were never + + + align:start position:0% +ways of doing business that were never +before possible using RFID as that + + align:start position:0% +before possible using RFID as that + + + align:start position:0% +before possible using RFID as that +technology that drives that. And um I + + align:start position:0% +technology that drives that. And um I + + + align:start position:0% +technology that drives that. And um I +just give you some examples there. It + + align:start position:0% +just give you some examples there. It + + + align:start position:0% +just give you some examples there. It +may be that we could use RFID as to + + align:start position:0% +may be that we could use RFID as to + + + align:start position:0% +may be that we could use RFID as to +radically change the way that retail + + align:start position:0% +radically change the way that retail + + + align:start position:0% +radically change the way that retail +stores stock their shelves. I don't know + + align:start position:0% +stores stock their shelves. I don't know + + + align:start position:0% +stores stock their shelves. I don't know +what that process might look like, but + + align:start position:0% +what that process might look like, but + + + align:start position:0% +what that process might look like, but +that might be a possibility. Obviously, + + align:start position:0% +that might be a possibility. Obviously, + + + align:start position:0% +that might be a possibility. Obviously, +as we move on down the line, the idea of + + align:start position:0% +as we move on down the line, the idea of + + + align:start position:0% +as we move on down the line, the idea of +the contactless checkout, you know, + + align:start position:0% +the contactless checkout, you know, + + + align:start position:0% +the contactless checkout, you know, +that's that would radically change that + + align:start position:0% +that's that would radically change that + + + align:start position:0% +that's that would radically change that +process, right, of of going up and + + align:start position:0% +process, right, of of going up and + + + align:start position:0% +process, right, of of going up and +handing your stuff off to a a cashier + + align:start position:0% +handing your stuff off to a a cashier + + + align:start position:0% +handing your stuff off to a a cashier +that swipes your items and puts it back + + align:start position:0% +that swipes your items and puts it back + + + align:start position:0% +that swipes your items and puts it back +in the cart. Radically changes that. Um, + + align:start position:0% +in the cart. Radically changes that. Um, + + + align:start position:0% +in the cart. Radically changes that. Um, +Sanjay mentioned yesterday the idea of + + align:start position:0% +Sanjay mentioned yesterday the idea of + + + align:start position:0% +Sanjay mentioned yesterday the idea of +the paper scan is radically changing + + align:start position:0% +the paper scan is radically changing + + + align:start position:0% +the paper scan is radically changing +that relationship between suppliers and + + align:start position:0% +that relationship between suppliers and + + + align:start position:0% +that relationship between suppliers and +retailers, changing that supply chain, + + align:start position:0% +retailers, changing that supply chain, + + + align:start position:0% +retailers, changing that supply chain, +okay? where where we get directtore + + align:start position:0% +okay? where where we get directtore + + + align:start position:0% +okay? where where we get directtore +deliveries and you know the retailer + + align:start position:0% +deliveries and you know the retailer + + + align:start position:0% +deliveries and you know the retailer +simply acts as a as a facilitator or a + + align:start position:0% +simply acts as a as a facilitator or a + + + align:start position:0% +simply acts as a as a facilitator or a +broker of those goods until they're + + align:start position:0% +broker of those goods until they're + + + align:start position:0% +broker of those goods until they're +sold. That's a radical change. But but + + align:start position:0% +sold. That's a radical change. But but + + + align:start position:0% +sold. That's a radical change. But but +what I think that we're seeing and and + + align:start position:0% +what I think that we're seeing and and + + + align:start position:0% +what I think that we're seeing and and +if you start looking at the case studies + + align:start position:0% +if you start looking at the case studies + + + align:start position:0% +if you start looking at the case studies +closely, what you what you'll find is + + align:start position:0% +closely, what you what you'll find is + + + align:start position:0% +closely, what you what you'll find is +that some companies are treating it as a + + align:start position:0% +that some companies are treating it as a + + + align:start position:0% +that some companies are treating it as a +as an incremental and and necessarily + + align:start position:0% +as an incremental and and necessarily + + + align:start position:0% +as an incremental and and necessarily +so. There there are many companies and + + align:start position:0% +so. There there are many companies and + + + align:start position:0% +so. There there are many companies and +and I've worked with several of the + + align:start position:0% +and I've worked with several of the + + + align:start position:0% +and I've worked with several of the +suppliers that you know are very very + + align:start position:0% +suppliers that you know are very very + + + align:start position:0% +suppliers that you know are very very +very good at what they do. All the + + align:start position:0% +very good at what they do. All the + + + align:start position:0% +very good at what they do. All the +lowhanging fruit has already been + + align:start position:0% +lowhanging fruit has already been + + + align:start position:0% +lowhanging fruit has already been +picked. So you have to look hard to find + + align:start position:0% +picked. So you have to look hard to find + + + align:start position:0% +picked. So you have to look hard to find +that incremental value. Now that doesn't + + align:start position:0% +that incremental value. Now that doesn't + + + align:start position:0% +that incremental value. Now that doesn't +mean they can't use it as a radical + + align:start position:0% +mean they can't use it as a radical + + + align:start position:0% +mean they can't use it as a radical +technology but there but they first look + + align:start position:0% +technology but there but they first look + + + align:start position:0% +technology but there but they first look +for that incremental change. Other + + align:start position:0% +for that incremental change. Other + + + align:start position:0% +for that incremental change. Other +companies however have actually + + align:start position:0% +companies however have actually + + + align:start position:0% +companies however have actually +purposely used RFID as a way to + + align:start position:0% +purposely used RFID as a way to + + + align:start position:0% +purposely used RFID as a way to +radically change their business. they + + align:start position:0% +radically change their business. they + + + align:start position:0% +radically change their business. they +weren't very good at what they were + + align:start position:0% +weren't very good at what they were + + + align:start position:0% +weren't very good at what they were +doing and RFID then actually becomes an + + align:start position:0% +doing and RFID then actually becomes an + + + align:start position:0% +doing and RFID then actually becomes an +excuse to really change what they're + + align:start position:0% +excuse to really change what they're + + + align:start position:0% +excuse to really change what they're +doing and uh as with most things the + + align:start position:0% +doing and uh as with most things the + + + align:start position:0% +doing and uh as with most things the +higher the risk the higher the return + + align:start position:0% +higher the risk the higher the return + + + align:start position:0% +higher the risk the higher the return +right so uh with with those following + + align:start position:0% +right so uh with with those following + + + align:start position:0% +right so uh with with those following +that radical or disruptive path the the + + align:start position:0% +that radical or disruptive path the the + + + align:start position:0% +that radical or disruptive path the the +opportunity for return is greater but + + align:start position:0% +opportunity for return is greater but + + + align:start position:0% +opportunity for return is greater but +the risk is higher that it won't work + + align:start position:0% +the risk is higher that it won't work + + + align:start position:0% +the risk is higher that it won't work +right now the the third element that we + + align:start position:0% +right now the the third element that we + + + align:start position:0% +right now the the third element that we +have to keep in mind here is who are the + + align:start position:0% +have to keep in mind here is who are the + + + align:start position:0% +have to keep in mind here is who are the +beneficiary beneficiaries of of these + + align:start position:0% +beneficiary beneficiaries of of these + + + align:start position:0% +beneficiary beneficiaries of of these +changes. Could it could be the retailer, + + align:start position:0% +changes. Could it could be the retailer, + + + align:start position:0% +changes. Could it could be the retailer, +it could be the supplier, could be the + + align:start position:0% +it could be the supplier, could be the + + + align:start position:0% +it could be the supplier, could be the +logistics provider, could be the + + align:start position:0% +logistics provider, could be the + + + align:start position:0% +logistics provider, could be the +consumer. Now, we we did a an out of + + align:start position:0% +consumer. Now, we we did a an out of + + + align:start position:0% +consumer. Now, we we did a an out of +stock study working with with Walmart, + + align:start position:0% +stock study working with with Walmart, + + + align:start position:0% +stock study working with with Walmart, +and we necessarily looked + + align:start position:0% +and we necessarily looked + + + align:start position:0% +and we necessarily looked +at one particular area that would + + align:start position:0% +at one particular area that would + + + align:start position:0% +at one particular area that would +provide benefit to several + + align:start position:0% +provide benefit to several + + + align:start position:0% +provide benefit to several +beneficiaries. + + align:start position:0% +beneficiaries. + + + align:start position:0% +beneficiaries. +look at a fairly constrained or a fairly + + align:start position:0% +look at a fairly constrained or a fairly + + + align:start position:0% +look at a fairly constrained or a fairly +narrow area. And that was how + + align:start position:0% +narrow area. And that was how + + + align:start position:0% +narrow area. And that was how +we kind of tweak that out of stock + + align:start position:0% +we kind of tweak that out of stock + + + align:start position:0% +we kind of tweak that out of stock +process to make it just a little bit + + align:start position:0% +process to make it just a little bit + + + align:start position:0% +process to make it just a little bit +better using RFID and in this case + + align:start position:0% +better using RFID and in this case + + + align:start position:0% +better using RFID and in this case +creating those automatic pick list for + + align:start position:0% +creating those automatic pick list for + + + align:start position:0% +creating those automatic pick list for +them to go to the back room and find + + align:start position:0% +them to go to the back room and find + + + align:start position:0% +them to go to the back room and find +that that product and take it to the + + align:start position:0% +that that product and take it to the + + + align:start position:0% +that that product and take it to the +shelf. So we so we tweaked it just a + + align:start position:0% +shelf. So we so we tweaked it just a + + + align:start position:0% +shelf. So we so we tweaked it just a +little bit. And so I wanted to put it in + + align:start position:0% +little bit. And so I wanted to put it in + + + align:start position:0% +little bit. And so I wanted to put it in +context of what we studied and and uh + + align:start position:0% +context of what we studied and and uh + + + align:start position:0% +context of what we studied and and uh +many of you I know have seen the white + + align:start position:0% +many of you I know have seen the white + + + align:start position:0% +many of you I know have seen the white +paper that was released because it's + + align:start position:0% +paper that was released because it's + + + align:start position:0% +paper that was released because it's +it's important that you put this thing + + align:start position:0% +it's important that you put this thing + + + align:start position:0% +it's important that you put this thing +in perspective. Keep in mind that what + + align:start position:0% +in perspective. Keep in mind that what + + + align:start position:0% +in perspective. Keep in mind that what +we looked at was an incremental use of + + align:start position:0% +we looked at was an incremental use of + + + align:start position:0% +we looked at was an incremental use of +the technology in a very narrow + + align:start position:0% +the technology in a very narrow + + + align:start position:0% +the technology in a very narrow +domain. It did help I mean out of stocks + + align:start position:0% +domain. It did help I mean out of stocks + + + align:start position:0% +domain. It did help I mean out of stocks +can help the supplier. It can help the + + align:start position:0% +can help the supplier. It can help the + + + align:start position:0% +can help the supplier. It can help the +retailer. It can help the consumer. So + + align:start position:0% +retailer. It can help the consumer. So + + + align:start position:0% +retailer. It can help the consumer. So +the beneficiary side was great, but the + + align:start position:0% +the beneficiary side was great, but the + + + align:start position:0% +the beneficiary side was great, but the +fact that we + + align:start position:0% +fact that we + + + align:start position:0% +fact that we +found changes that RFID that we could + + align:start position:0% +found changes that RFID that we could + + + align:start position:0% +found changes that RFID that we could +attribute to + + align:start position:0% +attribute to + + + align:start position:0% +attribute to +RFID is tells a lot because we were + + align:start position:0% +RFID is tells a lot because we were + + + align:start position:0% +RFID is tells a lot because we were +looking at a very narrow thing. Now to + + align:start position:0% +looking at a very narrow thing. Now to + + + align:start position:0% +looking at a very narrow thing. Now to +me, that's extremely encouraging because + + align:start position:0% +me, that's extremely encouraging because + + + align:start position:0% +me, that's extremely encouraging because +if you've narrowed it down to this much + + align:start position:0% +if you've narrowed it down to this much + + + align:start position:0% +if you've narrowed it down to this much +and you still found a fairly uh big + + align:start position:0% +and you still found a fairly uh big + + + align:start position:0% +and you still found a fairly uh big +difference, then what if we expand that + + align:start position:0% +difference, then what if we expand that + + + align:start position:0% +difference, then what if we expand that +on + + align:start position:0% +on + + + align:start position:0% +on +out? Okay. I think the possibilities I I + + align:start position:0% +out? Okay. I think the possibilities I I + + + align:start position:0% +out? Okay. I think the possibilities I I +I think we we've only set a very very + + align:start position:0% +I think we we've only set a very very + + + align:start position:0% +I think we we've only set a very very +small bar to clear and and and we we + + align:start position:0% +small bar to clear and and and we we + + + align:start position:0% +small bar to clear and and and we we +cleared it easily, but there's a lot + + align:start position:0% +cleared it easily, but there's a lot + + + align:start position:0% +cleared it easily, but there's a lot +more there that we can we can get at. + + align:start position:0% +more there that we can we can get at. + + + align:start position:0% +more there that we can we can get at. +And also keep in mind that that this + + align:start position:0% +And also keep in mind that that this + + + align:start position:0% +And also keep in mind that that this +idea of incremental versus radical, it's + + align:start position:0% +idea of incremental versus radical, it's + + + align:start position:0% +idea of incremental versus radical, it's +going to vary by the company. We're + + align:start position:0% +going to vary by the company. We're + + + align:start position:0% +going to vary by the company. We're +looking at a very abbreviated supply + + align:start position:0% +looking at a very abbreviated supply + + + align:start position:0% +looking at a very abbreviated supply +chain at this point. Okay, this is from + + align:start position:0% +chain at this point. Okay, this is from + + + align:start position:0% +chain at this point. Okay, this is from +the DC basically to the back room of the + + align:start position:0% +the DC basically to the back room of the + + + align:start position:0% +the DC basically to the back room of the +store and and so far the logistics + + align:start position:0% +store and and so far the logistics + + + align:start position:0% +store and and so far the logistics +segment has been largely + + align:start position:0% +segment has been largely + + + align:start position:0% +segment has been largely +overlooked. You notice that they're + + align:start position:0% +overlooked. You notice that they're + + + align:start position:0% +overlooked. You notice that they're +listed there, but there's not a lot + + align:start position:0% +listed there, but there's not a lot + + + align:start position:0% +listed there, but there's not a lot +going on when we talk about the supply + + align:start position:0% +going on when we talk about the supply + + + align:start position:0% +going on when we talk about the supply +chain and how it's involving the + + align:start position:0% +chain and how it's involving the + + + align:start position:0% +chain and how it's involving the +logistics + + align:start position:0% +logistics + + + align:start position:0% +logistics +arm. Okay. And just uh just very quickly + + align:start position:0% +arm. Okay. And just uh just very quickly + + + align:start position:0% +arm. Okay. And just uh just very quickly +on the on the the out of stocks uh + + align:start position:0% +on the on the the out of stocks uh + + + align:start position:0% +on the on the the out of stocks uh +keeping in in perspective of where that + + align:start position:0% +keeping in in perspective of where that + + + align:start position:0% +keeping in in perspective of where that +was on that chart, you know, the fact + + align:start position:0% +was on that chart, you know, the fact + + + align:start position:0% +was on that chart, you know, the fact +that we were able to find, you know, + + align:start position:0% +that we were able to find, you know, + + + align:start position:0% +that we were able to find, you know, +improvements between pre and post RFID + + align:start position:0% +improvements between pre and post RFID + + + align:start position:0% +improvements between pre and post RFID +and then and in between the pilot and + + align:start position:0% +and then and in between the pilot and + + + align:start position:0% +and then and in between the pilot and +control stores, we we found those + + align:start position:0% +control stores, we we found those + + + align:start position:0% +control stores, we we found those +differences even though we were + + align:start position:0% +differences even though we were + + + align:start position:0% +differences even though we were +constraining ourselves to an incremental + + align:start position:0% +constraining ourselves to an incremental + + + align:start position:0% +constraining ourselves to an incremental +change uh in a very small + + align:start position:0% +change uh in a very small + + + align:start position:0% +change uh in a very small +area. Okay, that that's that just give + + align:start position:0% +area. Okay, that that's that just give + + + align:start position:0% +area. Okay, that that's that just give +you some things to think about there. I + + align:start position:0% +you some things to think about there. I + + + align:start position:0% +you some things to think about there. I +want to very quickly run through, you + + align:start position:0% +want to very quickly run through, you + + + align:start position:0% +want to very quickly run through, you +know, also it's important we're doing + + align:start position:0% +know, also it's important we're doing + + + align:start position:0% +know, also it's important we're doing +the research, but we're also teaching + + align:start position:0% +the research, but we're also teaching + + + align:start position:0% +the research, but we're also teaching +students and others about RFID. We're + + align:start position:0% +students and others about RFID. We're + + + align:start position:0% +students and others about RFID. We're +trying to we're trying to turn out + + align:start position:0% +trying to we're trying to turn out + + + align:start position:0% +trying to we're trying to turn out +people. Michael O'Shea said uh last year + + align:start position:0% +people. Michael O'Shea said uh last year + + + align:start position:0% +people. Michael O'Shea said uh last year +that that the CIO of Kimberly Clark said + + align:start position:0% +that that the CIO of Kimberly Clark said + + + align:start position:0% +that that the CIO of Kimberly Clark said +that uh you know there's such a der of + + align:start position:0% +that uh you know there's such a der of + + + align:start position:0% +that uh you know there's such a der of +experience out there that if somebody + + align:start position:0% +experience out there that if somebody + + + align:start position:0% +experience out there that if somebody +walks by a reader and and says RFID and + + align:start position:0% +walks by a reader and and says RFID and + + + align:start position:0% +walks by a reader and and says RFID and +not riffid, that makes them an RFID + + align:start position:0% +not riffid, that makes them an RFID + + + align:start position:0% +not riffid, that makes them an RFID +expert. Well, we're trying to to stamp + + align:start position:0% +expert. Well, we're trying to to stamp + + + align:start position:0% +expert. Well, we're trying to to stamp +out some of that ignorance by by + + align:start position:0% +out some of that ignorance by by + + + align:start position:0% +out some of that ignorance by by +training people and uh so we've got + + align:start position:0% +training people and uh so we've got + + + align:start position:0% +training people and uh so we've got +dedicated courses in in the the business + + align:start position:0% +dedicated courses in in the the business + + + align:start position:0% +dedicated courses in in the the business +school which which I personally teach uh + + align:start position:0% +school which which I personally teach uh + + + align:start position:0% +school which which I personally teach uh +where we have students uh from across + + align:start position:0% +where we have students uh from across + + + align:start position:0% +where we have students uh from across +the college and and graduate students as + + align:start position:0% +the college and and graduate students as + + + align:start position:0% +the college and and graduate students as +well. So it's undergraduate and graduate + + align:start position:0% +well. So it's undergraduate and graduate + + + align:start position:0% +well. So it's undergraduate and graduate +uh we they're doing live projects for + + align:start position:0% +uh we they're doing live projects for + + + align:start position:0% +uh we they're doing live projects for +companies uh we've got dedicated courses + + align:start position:0% +companies uh we've got dedicated courses + + + align:start position:0% +companies uh we've got dedicated courses +computer science computer engineering + + align:start position:0% +computer science computer engineering + + + align:start position:0% +computer science computer engineering +and then and then interwoven into a lot + + align:start position:0% +and then and then interwoven into a lot + + + align:start position:0% +and then and then interwoven into a lot +of different courses. So we we've got + + align:start position:0% +of different courses. So we we've got + + + align:start position:0% +of different courses. So we we've got +about this semester or last semester we + + align:start position:0% +about this semester or last semester we + + + align:start position:0% +about this semester or last semester we +about had about 80 students uh involved + + align:start position:0% +about had about 80 students uh involved + + + align:start position:0% +about had about 80 students uh involved +in RFID in some some form or fashion. Uh + + align:start position:0% +in RFID in some some form or fashion. Uh + + + align:start position:0% +in RFID in some some form or fashion. Uh +that's over 100 this semester. Um we + + align:start position:0% +that's over 100 this semester. Um we + + + align:start position:0% +that's over 100 this semester. Um we +also uh provide testing and training + + align:start position:0% +also uh provide testing and training + + + align:start position:0% +also uh provide testing and training +services to the industry. Uh one of the + + align:start position:0% +services to the industry. Uh one of the + + + align:start position:0% +services to the industry. Uh one of the +things that we do is we help um + + align:start position:0% +things that we do is we help um + + + align:start position:0% +things that we do is we help um +companies determine tag and tag + + align:start position:0% +companies determine tag and tag + + + align:start position:0% +companies determine tag and tag +placement on their products so that it's + + align:start position:0% +placement on their products so that it's + + + align:start position:0% +placement on their products so that it's +ready to go through an RFID enabled + + align:start position:0% +ready to go through an RFID enabled + + + align:start position:0% +ready to go through an RFID enabled +supply chain. Uh and we've started + + align:start position:0% +supply chain. Uh and we've started + + + align:start position:0% +supply chain. Uh and we've started +coupling our testing with training. One + + align:start position:0% +coupling our testing with training. One + + + align:start position:0% +coupling our testing with training. One +of the things we found out was that, you + + align:start position:0% +of the things we found out was that, you + + + align:start position:0% +of the things we found out was that, you +know, people would just send us a box of + + align:start position:0% +know, people would just send us a box of + + + align:start position:0% +know, people would just send us a box of +their product or case or pallet of their + + align:start position:0% +their product or case or pallet of their + + + align:start position:0% +their product or case or pallet of their +product and say, "Here, help me figure + + align:start position:0% +product and say, "Here, help me figure + + + align:start position:0% +product and say, "Here, help me figure +this out." But they didn't understand + + align:start position:0% +this out." But they didn't understand + + + align:start position:0% +this out." But they didn't understand +RFID. And our most successful um + + align:start position:0% +RFID. And our most successful um + + + align:start position:0% +RFID. And our most successful um +uh projects were when they actually came + + align:start position:0% +uh projects were when they actually came + + + align:start position:0% +uh projects were when they actually came +in and spent time with us going through + + align:start position:0% +in and spent time with us going through + + + align:start position:0% +in and spent time with us going through +the testing and understanding RFID. So, + + align:start position:0% +the testing and understanding RFID. So, + + + align:start position:0% +the testing and understanding RFID. So, +we've actually started coupling that uh + + align:start position:0% +we've actually started coupling that uh + + + align:start position:0% +we've actually started coupling that uh +now formally where we bring the + + align:start position:0% +now formally where we bring the + + + align:start position:0% +now formally where we bring the +companies in, they spend a couple of + + align:start position:0% +companies in, they spend a couple of + + + align:start position:0% +companies in, they spend a couple of +days with us learning about RFID as we + + align:start position:0% +days with us learning about RFID as we + + + align:start position:0% +days with us learning about RFID as we +uh test their products. Um, our lab + + align:start position:0% +uh test their products. Um, our lab + + + align:start position:0% +uh test their products. Um, our lab +facility there at the University of + + align:start position:0% +facility there at the University of + + + align:start position:0% +facility there at the University of +Arkansas, we we're actually off-campus a + + align:start position:0% +Arkansas, we we're actually off-campus a + + + align:start position:0% +Arkansas, we we're actually off-campus a +few miles uh in a working warehouse and + + align:start position:0% +few miles uh in a working warehouse and + + + align:start position:0% +few miles uh in a working warehouse and +manufacturing environment. We have about + + align:start position:0% +manufacturing environment. We have about + + + align:start position:0% +manufacturing environment. We have about +8,000 square feet in Hannah's Candle + + align:start position:0% +8,000 square feet in Hannah's Candle + + + align:start position:0% +8,000 square feet in Hannah's Candle +Company uh which uh they manufacture and + + align:start position:0% +Company uh which uh they manufacture and + + + align:start position:0% +Company uh which uh they manufacture and +then their distribution center is there + + align:start position:0% +then their distribution center is there + + + align:start position:0% +then their distribution center is there +as well. Uh and that's um unfortunately + + align:start position:0% +as well. Uh and that's um unfortunately + + + align:start position:0% +as well. Uh and that's um unfortunately +it is in the distribution center uh + + align:start position:0% +it is in the distribution center uh + + + align:start position:0% +it is in the distribution center uh +part. So the there is no control over + + align:start position:0% +part. So the there is no control over + + + align:start position:0% +part. So the there is no control over +the temperature. So the temperature + + align:start position:0% +the temperature. So the temperature + + + align:start position:0% +the temperature. So the temperature +inside is plus or - 10° what it is + + align:start position:0% +inside is plus or - 10° what it is + + + align:start position:0% +inside is plus or - 10° what it is +outside. Uh, so we also have um when we + + align:start position:0% +outside. Uh, so we also have um when we + + + align:start position:0% +outside. Uh, so we also have um when we +have to test stuff in the cold chain, + + align:start position:0% +have to test stuff in the cold chain, + + + align:start position:0% +have to test stuff in the cold chain, +we've got about a 4,500 square foot + + align:start position:0% +we've got about a 4,500 square foot + + + align:start position:0% +we've got about a 4,500 square foot +square foot facility in Zero Mountain, + + align:start position:0% +square foot facility in Zero Mountain, + + + align:start position:0% +square foot facility in Zero Mountain, +which is a a cold storage facility. And + + align:start position:0% +which is a a cold storage facility. And + + + align:start position:0% +which is a a cold storage facility. And +we've got two labs there, one at 36 + + align:start position:0% +we've got two labs there, one at 36 + + + align:start position:0% +we've got two labs there, one at 36 +degrees and one in minus 10. Uh, so we + + align:start position:0% +degrees and one in minus 10. Uh, so we + + + align:start position:0% +degrees and one in minus 10. Uh, so we +can test stuff there. Our lab is set up + + align:start position:0% +can test stuff there. Our lab is set up + + + align:start position:0% +can test stuff there. Our lab is set up +to replicate really everything that a + + align:start position:0% +to replicate really everything that a + + + align:start position:0% +to replicate really everything that a +that a box sees at this point through + + align:start position:0% +that a box sees at this point through + + + align:start position:0% +that a box sees at this point through +the abbreviated supply chain. And we are + + align:start position:0% +the abbreviated supply chain. And we are + + + align:start position:0% +the abbreviated supply chain. And we are +one of only four labs at this point + + align:start position:0% +one of only four labs at this point + + + align:start position:0% +one of only four labs at this point +that's accredited by EPC Global uh as a + + align:start position:0% +that's accredited by EPC Global uh as a + + + align:start position:0% +that's accredited by EPC Global uh as a +testing facility and the only academic + + align:start position:0% +testing facility and the only academic + + + align:start position:0% +testing facility and the only academic +lab in the world. And just to give you + + align:start position:0% +lab in the world. And just to give you + + + align:start position:0% +lab in the world. And just to give you +some quick quick pictures here of our + + align:start position:0% +some quick quick pictures here of our + + + align:start position:0% +some quick quick pictures here of our +lab and I'm I'm got two minutes to wrap + + align:start position:0% +lab and I'm I'm got two minutes to wrap + + + align:start position:0% +lab and I'm I'm got two minutes to wrap +up. That's the outside of our lab. A + + align:start position:0% +up. That's the outside of our lab. A + + + align:start position:0% +up. That's the outside of our lab. A +truck backed up to our dock. Uh that's + + align:start position:0% +truck backed up to our dock. Uh that's + + + align:start position:0% +truck backed up to our dock. Uh that's +the inside of the lab looking out that + + align:start position:0% +the inside of the lab looking out that + + + align:start position:0% +the inside of the lab looking out that +that same dock door. Um uh view from our + + align:start position:0% +that same dock door. Um uh view from our + + + align:start position:0% +that same dock door. Um uh view from our +lab. The conveyor system that we have in + + align:start position:0% +lab. The conveyor system that we have in + + + align:start position:0% +lab. The conveyor system that we have in +um in there. We we had actually were + + align:start position:0% +um in there. We we had actually were + + + align:start position:0% +um in there. We we had actually were +fortunate to have a conveyor system that + + align:start position:0% +fortunate to have a conveyor system that + + + align:start position:0% +fortunate to have a conveyor system that +was custom designed and built for our + + align:start position:0% +was custom designed and built for our + + + align:start position:0% +was custom designed and built for our +lab that replicates uh um you know + + align:start position:0% +lab that replicates uh um you know + + + align:start position:0% +lab that replicates uh um you know +sorting and merging and and up to 700 ft + + align:start position:0% +sorting and merging and and up to 700 ft + + + align:start position:0% +sorting and merging and and up to 700 ft +per minute. The the whole works um and + + align:start position:0% +per minute. The the whole works um and + + + align:start position:0% +per minute. The the whole works um and +then um pallet rack and and backroom + + align:start position:0% +then um pallet rack and and backroom + + + align:start position:0% +then um pallet rack and and backroom +storage facilities, forklifts, + + align:start position:0% +storage facilities, forklifts, + + + align:start position:0% +storage facilities, forklifts, +etc. Okay. Uh at this point um I believe + + align:start position:0% +etc. Okay. Uh at this point um I believe + + + align:start position:0% +etc. Okay. Uh at this point um I believe +the next on the agenda is is Simon. So + + align:start position:0% +the next on the agenda is is Simon. So + + + align:start position:0% +the next on the agenda is is Simon. So +I'll turn it over to you, Simon. And let + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +me + + align:start position:0% + + + + align:start position:0% + +Okay. Okay. Thanks, Bill. And good + + align:start position:0% +Okay. Okay. Thanks, Bill. And good + + + align:start position:0% +Okay. Okay. Thanks, Bill. And good +morning, everybody. um really want to + + align:start position:0% +morning, everybody. um really want to + + + align:start position:0% +morning, everybody. um really want to +touch on the the opportunities and + + align:start position:0% +touch on the the opportunities and + + + align:start position:0% +touch on the the opportunities and +issues that that we see in the retail + + align:start position:0% +issues that that we see in the retail + + + align:start position:0% +issues that that we see in the retail +supply chain. Um before I do that, just + + align:start position:0% +supply chain. Um before I do that, just + + + align:start position:0% +supply chain. Um before I do that, just +to to step back a little bit and see + + align:start position:0% +to to step back a little bit and see + + + align:start position:0% +to to step back a little bit and see +what uh we've all accomplished in the + + align:start position:0% +what uh we've all accomplished in the + + + align:start position:0% +what uh we've all accomplished in the +last last few years. Uh so in 2001 2002 + + align:start position:0% +last last few years. Uh so in 2001 2002 + + + align:start position:0% +last last few years. Uh so in 2001 2002 +uh we had the auto ID center field + + align:start position:0% +uh we had the auto ID center field + + + align:start position:0% +uh we had the auto ID center field +trials and uh installation points around + + align:start position:0% +trials and uh installation points around + + + align:start position:0% +trials and uh installation points around +a dock door for instance took hours to + + align:start position:0% +a dock door for instance took hours to + + + align:start position:0% +a dock door for instance took hours to +install and and probably minutes to + + align:start position:0% +install and and probably minutes to + + + align:start position:0% +install and and probably minutes to +destroy or somebody to to go move those + + align:start position:0% +destroy or somebody to to go move those + + + align:start position:0% +destroy or somebody to to go move those +things. Um so it wasn't scalable, wasn't + + align:start position:0% +things. Um so it wasn't scalable, wasn't + + + align:start position:0% +things. Um so it wasn't scalable, wasn't +deployable and certainly wasn't wasn't + + align:start position:0% +deployable and certainly wasn't wasn't + + + align:start position:0% +deployable and certainly wasn't wasn't +supportable. Uh but a lot of learning + + align:start position:0% +supportable. Uh but a lot of learning + + + align:start position:0% +supportable. Uh but a lot of learning +came out of that uh for us all then to + + align:start position:0% +came out of that uh for us all then to + + + align:start position:0% +came out of that uh for us all then to +focus on what we needed for deployable + + align:start position:0% +focus on what we needed for deployable + + + align:start position:0% +focus on what we needed for deployable +solutions. And the one key message that + + align:start position:0% +solutions. And the one key message that + + + align:start position:0% +solutions. And the one key message that +we were putting out at the time is that + + align:start position:0% +we were putting out at the time is that + + + align:start position:0% +we were putting out at the time is that +they should be futurep proofed as far as + + align:start position:0% +they should be futurep proofed as far as + + + align:start position:0% +they should be futurep proofed as far as +possible knowing that Gen 2 was on the + + align:start position:0% +possible knowing that Gen 2 was on the + + + align:start position:0% +possible knowing that Gen 2 was on the +horizon that we wanted to deploy things + + align:start position:0% +horizon that we wanted to deploy things + + + align:start position:0% +horizon that we wanted to deploy things +that were software + + align:start position:0% +that were software + + + align:start position:0% +that were software +upgradable. And in 2004 then we really + + align:start position:0% +upgradable. And in 2004 then we really + + + align:start position:0% +upgradable. And in 2004 then we really +stepped up a notch to to drive for + + align:start position:0% +stepped up a notch to to drive for + + + align:start position:0% +stepped up a notch to to drive for +mobile solutions whether that be + + align:start position:0% +mobile solutions whether that be + + + align:start position:0% +mobile solutions whether that be +handheld solutions uh in particular + + align:start position:0% +handheld solutions uh in particular + + + align:start position:0% +handheld solutions uh in particular +forklift solutions which uh is important + + align:start position:0% +forklift solutions which uh is important + + + align:start position:0% +forklift solutions which uh is important +both to the retailer and a lot of + + align:start position:0% +both to the retailer and a lot of + + + align:start position:0% +both to the retailer and a lot of +suppliers. A lot of those things are + + align:start position:0% +suppliers. A lot of those things are + + + align:start position:0% +suppliers. A lot of those things are +still in the the early stages especially + + align:start position:0% +still in the the early stages especially + + + align:start position:0% +still in the the early stages especially +around mobile + + align:start position:0% +around mobile + + + align:start position:0% +around mobile +solutions. So current situation is we + + align:start position:0% +solutions. So current situation is we + + + align:start position:0% +solutions. So current situation is we +have robust fixed reader solutions + + align:start position:0% +have robust fixed reader solutions + + + align:start position:0% +have robust fixed reader solutions +allowing us to deploy up to 20 read + + align:start position:0% +allowing us to deploy up to 20 read + + + align:start position:0% +allowing us to deploy up to 20 read +points in a in a store in a matter of + + align:start position:0% +points in a in a store in a matter of + + + align:start position:0% +points in a in a store in a matter of +hours in a couple of hours. So taking + + align:start position:0% +hours in a couple of hours. So taking + + + align:start position:0% +hours in a couple of hours. So taking +that time down from days to hours that + + align:start position:0% +that time down from days to hours that + + + align:start position:0% +that time down from days to hours that +reduces the cost cost of deployment. So + + align:start position:0% +reduces the cost cost of deployment. So + + + align:start position:0% +reduces the cost cost of deployment. So +the cost of deployment isn't just around + + align:start position:0% +the cost of deployment isn't just around + + + align:start position:0% +the cost of deployment isn't just around +readers and antenna. A lot of the cost + + align:start position:0% +readers and antenna. A lot of the cost + + + align:start position:0% +readers and antenna. A lot of the cost +is in cabling and actual insulation of + + align:start position:0% +is in cabling and actual insulation of + + + align:start position:0% +is in cabling and actual insulation of +the + + align:start position:0% +the + + + align:start position:0% +the +equipment. So it's a little bit like + + align:start position:0% +equipment. So it's a little bit like + + + align:start position:0% +equipment. So it's a little bit like +tags. It's not just the IC chip that we + + align:start position:0% +tags. It's not just the IC chip that we + + + align:start position:0% +tags. It's not just the IC chip that we +can take cost out of. It's that whole + + align:start position:0% +can take cost out of. It's that whole + + + align:start position:0% +can take cost out of. It's that whole +process driving for common operating + + align:start position:0% +process driving for common operating + + + align:start position:0% +process driving for common operating +systems so that we can support it + + align:start position:0% +systems so that we can support it + + + align:start position:0% +systems so that we can support it +centrally and + + align:start position:0% +centrally and + + + align:start position:0% +centrally and +maintain the robustness of that that + + align:start position:0% +maintain the robustness of that that + + + align:start position:0% +maintain the robustness of that that +system. We're starting to deploy + + align:start position:0% +system. We're starting to deploy + + + align:start position:0% +system. We're starting to deploy +handhelds in the the next few months. So + + align:start position:0% +handhelds in the the next few months. So + + + align:start position:0% +handhelds in the the next few months. So +getting the first mobile devices out + + align:start position:0% +getting the first mobile devices out + + + align:start position:0% +getting the first mobile devices out +there. And I think that's when our store + + align:start position:0% +there. And I think that's when our store + + + align:start position:0% +there. And I think that's when our store +associates will start to see some of + + align:start position:0% +associates will start to see some of + + + align:start position:0% +associates will start to see some of +those transformational changes rather + + align:start position:0% +those transformational changes rather + + + align:start position:0% +those transformational changes rather +than just the iterative process changes + + align:start position:0% +than just the iterative process changes + + + align:start position:0% +than just the iterative process changes +that we've had out there in the uh in + + align:start position:0% +that we've had out there in the uh in + + + align:start position:0% +that we've had out there in the uh in +the store so far. Things that they can + + align:start position:0% +the store so far. Things that they can + + + align:start position:0% +the store so far. Things that they can +actually touch and feel and see the + + align:start position:0% +actually touch and feel and see the + + + align:start position:0% +actually touch and feel and see the +difference with RFID. So our fixed read + + align:start position:0% +difference with RFID. So our fixed read + + + align:start position:0% +difference with RFID. So our fixed read +points are collecting data in the + + align:start position:0% +points are collecting data in the + + + align:start position:0% +points are collecting data in the +background and suggesting items to pick. + + align:start position:0% +background and suggesting items to pick. + + + align:start position:0% +background and suggesting items to pick. +But really to a store associate today, + + align:start position:0% +But really to a store associate today, + + + align:start position:0% +But really to a store associate today, +what is RFI doing? They don't know. They + + align:start position:0% +what is RFI doing? They don't know. They + + + align:start position:0% +what is RFI doing? They don't know. They +don't see that as visible. Sure, they're + + align:start position:0% +don't see that as visible. Sure, they're + + + align:start position:0% +don't see that as visible. Sure, they're +picking more product and moving it out + + align:start position:0% +picking more product and moving it out + + + align:start position:0% +picking more product and moving it out +to the the floor quicker, but once we + + align:start position:0% +to the the floor quicker, but once we + + + align:start position:0% +to the the floor quicker, but once we +get these mobile devices in their hands, + + align:start position:0% +get these mobile devices in their hands, + + + align:start position:0% +get these mobile devices in their hands, +then that will help them home in on + + align:start position:0% +then that will help them home in on + + + align:start position:0% +then that will help them home in on +where that product is and really start + + align:start position:0% +where that product is and really start + + + align:start position:0% +where that product is and really start +to streamline their + + align:start position:0% +to streamline their + + + align:start position:0% +to streamline their +process. We're very close to deploying + + align:start position:0% +process. We're very close to deploying + + + align:start position:0% +process. We're very close to deploying +the first forklift solution in our + + align:start position:0% +the first forklift solution in our + + + align:start position:0% +the first forklift solution in our +enterprise to read pallet tags and + + align:start position:0% +enterprise to read pallet tags and + + + align:start position:0% +enterprise to read pallet tags and +location tags. So, we can have a a + + align:start position:0% +location tags. So, we can have a a + + + align:start position:0% +location tags. So, we can have a a +pallet locating system in our Sam's Club + + align:start position:0% +pallet locating system in our Sam's Club + + + align:start position:0% +pallet locating system in our Sam's Club +operation, for example. + + align:start position:0% +operation, for example. + + + align:start position:0% +operation, for example. +Taking that learning, then we can then + + align:start position:0% +Taking that learning, then we can then + + + align:start position:0% +Taking that learning, then we can then +take that to our distribution + + align:start position:0% +take that to our distribution + + + align:start position:0% +take that to our distribution +centers to see how we can use location + + align:start position:0% +centers to see how we can use location + + + align:start position:0% +centers to see how we can use location +tracking and putting pallets away and + + align:start position:0% +tracking and putting pallets away and + + + align:start position:0% +tracking and putting pallets away and +dropping them down and start to + + align:start position:0% +dropping them down and start to + + + align:start position:0% +dropping them down and start to +streamline processes there as we move + + align:start position:0% +streamline processes there as we move + + + align:start position:0% +streamline processes there as we move +move forward in the + + align:start position:0% + + + + align:start position:0% + +future. But even those forklift + + align:start position:0% +future. But even those forklift + + + align:start position:0% +future. But even those forklift +solutions are still at the early stages. + + align:start position:0% +solutions are still at the early stages. + + + align:start position:0% +solutions are still at the early stages. +So we can read a pallet tag today. + + align:start position:0% +So we can read a pallet tag today. + + + align:start position:0% +So we can read a pallet tag today. +In the future, we need to to be able to + + align:start position:0% +In the future, we need to to be able to + + + align:start position:0% +In the future, we need to to be able to +read cases or the same amount of cases + + align:start position:0% +read cases or the same amount of cases + + + align:start position:0% +read cases or the same amount of cases +we do today on a dock door from that + + align:start position:0% +we do today on a dock door from that + + + align:start position:0% +we do today on a dock door from that +pallet read on the + + align:start position:0% +pallet read on the + + + align:start position:0% +pallet read on the +forklift. That way we can start to + + align:start position:0% +forklift. That way we can start to + + + align:start position:0% +forklift. That way we can start to +eliminate deploying readers around dock + + align:start position:0% +eliminate deploying readers around dock + + + align:start position:0% +eliminate deploying readers around dock +doors and reduce our overall costs and + + align:start position:0% +doors and reduce our overall costs and + + + align:start position:0% +doors and reduce our overall costs and +just have those readers on + + align:start position:0% +just have those readers on + + + align:start position:0% +just have those readers on +forklifts. We're at the very early + + align:start position:0% +forklifts. We're at the very early + + + align:start position:0% +forklifts. We're at the very early +stages, the infant stages of wearable + + align:start position:0% +stages, the infant stages of wearable + + + align:start position:0% +stages, the infant stages of wearable +solutions. + + align:start position:0% +solutions. + + + align:start position:0% +solutions. +So whether that be something that an + + align:start position:0% +So whether that be something that an + + + align:start position:0% +So whether that be something that an +associate would wear on their the belt + + align:start position:0% +associate would wear on their the belt + + + align:start position:0% +associate would wear on their the belt +or within a vest and the system is + + align:start position:0% +or within a vest and the system is + + + align:start position:0% +or within a vest and the system is +reading in the + + align:start position:0% +reading in the + + + align:start position:0% +reading in the +background and talking back to them and + + align:start position:0% +background and talking back to them and + + + align:start position:0% +background and talking back to them and +give them work to + + align:start position:0% +give them work to + + + align:start position:0% +give them work to +do. And as Bill mentioned, Gen Two is + + align:start position:0% +do. And as Bill mentioned, Gen Two is + + + align:start position:0% +do. And as Bill mentioned, Gen Two is +starting to roll out. We're enabled in + + align:start position:0% +starting to roll out. We're enabled in + + + align:start position:0% +starting to roll out. We're enabled in +our supply chain and starting to receive + + align:start position:0% +our supply chain and starting to receive + + + align:start position:0% +our supply chain and starting to receive +product uh on Gen Two uh tags and prices + + align:start position:0% +product uh on Gen Two uh tags and prices + + + align:start position:0% +product uh on Gen Two uh tags and prices +are falling. tag prices are are falling + + align:start position:0% +are falling. tag prices are are falling + + + align:start position:0% +are falling. tag prices are are falling +through the the + + align:start position:0% +through the the + + + align:start position:0% +through the the +floor. So what has all that technology + + align:start position:0% +floor. So what has all that technology + + + align:start position:0% +floor. So what has all that technology +delivered so far? What are the benefits + + align:start position:0% +delivered so far? What are the benefits + + + align:start position:0% +delivered so far? What are the benefits +of that? So it's allowed the first sort + + align:start position:0% +of that? So it's allowed the first sort + + + align:start position:0% +of that? So it's allowed the first sort +of automation of tasks around pick lists + + align:start position:0% +of automation of tasks around pick lists + + + align:start position:0% +of automation of tasks around pick lists +and manual order controls and our + + align:start position:0% +and manual order controls and our + + + align:start position:0% +and manual order controls and our +associates to work more efficiently. + + align:start position:0% +associates to work more efficiently. + + + align:start position:0% +associates to work more efficiently. +That's improved our customer service and + + align:start position:0% +That's improved our customer service and + + + align:start position:0% +That's improved our customer service and +our offering of product on the shelf at + + align:start position:0% +our offering of product on the shelf at + + + align:start position:0% +our offering of product on the shelf at +the right time. It's really taken the + + align:start position:0% +the right time. It's really taken the + + + align:start position:0% +the right time. It's really taken the +theory out of the lab environment into + + align:start position:0% +theory out of the lab environment into + + + align:start position:0% +theory out of the lab environment into +the real world. And I think once you + + align:start position:0% +the real world. And I think once you + + + align:start position:0% +the real world. And I think once you +take that step, that's when a lot of the + + align:start position:0% +take that step, that's when a lot of the + + + align:start position:0% +take that step, that's when a lot of the +the real learning comes + + align:start position:0% +the real learning comes + + + align:start position:0% +the real learning comes +about. And Bill mentioned the study that + + align:start position:0% +about. And Bill mentioned the study that + + + align:start position:0% +about. And Bill mentioned the study that +they performed on our first changes + + align:start position:0% +they performed on our first changes + + + align:start position:0% +they performed on our first changes +where out of stocks were reduced by 16%. + + align:start position:0% +where out of stocks were reduced by 16%. + + + align:start position:0% +where out of stocks were reduced by 16%. +So you can see from a a nonrfid + + align:start position:0% +So you can see from a a nonrfid + + + align:start position:0% +So you can see from a a nonrfid +environment in the different store + + align:start position:0% +environment in the different store + + + align:start position:0% +environment in the different store +formats here to a partial implementation + + align:start position:0% +formats here to a partial implementation + + + align:start position:0% +formats here to a partial implementation +that we did uh we had some caps on the + + align:start position:0% +that we did uh we had some caps on the + + + align:start position:0% +that we did uh we had some caps on the +number of autopicks that we would + + align:start position:0% +number of autopicks that we would + + + align:start position:0% +number of autopicks that we would +actually suggest to to store associates + + align:start position:0% +actually suggest to to store associates + + + align:start position:0% +actually suggest to to store associates +and then to a full-blown RFID solution + + align:start position:0% +and then to a full-blown RFID solution + + + align:start position:0% +and then to a full-blown RFID solution +on those products that were enabled at + + align:start position:0% +on those products that were enabled at + + + align:start position:0% +on those products that were enabled at +the + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +measuring the out of stocks in the + + align:start position:0% +measuring the out of stocks in the + + + align:start position:0% +measuring the out of stocks in the +control stores versus um sorry the the + + align:start position:0% +control stores versus um sorry the the + + + align:start position:0% +control stores versus um sorry the the +pilot stores versus control stores. + + align:start position:0% +pilot stores versus control stores. + + + align:start position:0% +pilot stores versus control stores. +Those RFID stores performed 63% better + + align:start position:0% +Those RFID stores performed 63% better + + + align:start position:0% +Those RFID stores performed 63% better +in stocking the shelves than the control + + align:start position:0% +in stocking the shelves than the control + + + align:start position:0% +in stocking the shelves than the control +stores + + align:start position:0% +stores + + + align:start position:0% +stores +did. And within the same store, within + + align:start position:0% +did. And within the same store, within + + + align:start position:0% +did. And within the same store, within +the pilot store, looking at tagged + + align:start position:0% +the pilot store, looking at tagged + + + align:start position:0% +the pilot store, looking at tagged +product versus non-tagged product, we + + align:start position:0% +product versus non-tagged product, we + + + align:start position:0% +product versus non-tagged product, we +saw those replenish three times + + align:start position:0% +saw those replenish three times + + + align:start position:0% +saw those replenish three times +faster, those products with RFID tags. + + align:start position:0% +faster, those products with RFID tags. + + + align:start position:0% +faster, those products with RFID tags. +So, as Bill said, those first iterative + + align:start position:0% +So, as Bill said, those first iterative + + + align:start position:0% +So, as Bill said, those first iterative +process changes were starting to deliver + + align:start position:0% +process changes were starting to deliver + + + align:start position:0% +process changes were starting to deliver +dramatic results on the tag product we + + align:start position:0% +dramatic results on the tag product we + + + align:start position:0% +dramatic results on the tag product we +had in those + + align:start position:0% + + + + align:start position:0% + +stores. So, what about the issues and + + align:start position:0% +stores. So, what about the issues and + + + align:start position:0% +stores. So, what about the issues and +opportunities? Well, the issues remain + + align:start position:0% +opportunities? Well, the issues remain + + + align:start position:0% +opportunities? Well, the issues remain +the same as they did four years ago, 10 + + align:start position:0% +the same as they did four years ago, 10 + + + align:start position:0% +the same as they did four years ago, 10 +years ago. It's all about data accuracy + + align:start position:0% +years ago. It's all about data accuracy + + + align:start position:0% +years ago. It's all about data accuracy +and real-time data. Data accuracy drives + + align:start position:0% +and real-time data. Data accuracy drives + + + align:start position:0% +and real-time data. Data accuracy drives +both availability of product in the + + align:start position:0% +both availability of product in the + + + align:start position:0% +both availability of product in the +whole supply + + align:start position:0% +whole supply + + + align:start position:0% +whole supply +chain, the speed of that that + + align:start position:0% +chain, the speed of that that + + + align:start position:0% +chain, the speed of that that +merchandise flowing through the supply + + align:start position:0% +merchandise flowing through the supply + + + align:start position:0% +merchandise flowing through the supply +chain and the amount of inventory we + + align:start position:0% +chain and the amount of inventory we + + + align:start position:0% +chain and the amount of inventory we +have to hold that has a direct relation + + align:start position:0% +have to hold that has a direct relation + + + align:start position:0% +have to hold that has a direct relation +to to + + align:start position:0% +to to + + + align:start position:0% +to to +costs. And as Bill said, it's important + + align:start position:0% +costs. And as Bill said, it's important + + + align:start position:0% +costs. And as Bill said, it's important +to to see how we use that data that we + + align:start position:0% +to to see how we use that data that we + + + align:start position:0% +to to see how we use that data that we +don't get swamped with data. We're using + + align:start position:0% +don't get swamped with data. We're using + + + align:start position:0% +don't get swamped with data. We're using +it. It's actionable for store + + align:start position:0% +it. It's actionable for store + + + align:start position:0% +it. It's actionable for store +associates, for replenishment + + align:start position:0% +associates, for replenishment + + + align:start position:0% +associates, for replenishment +associates, and for our + + align:start position:0% +associates, and for our + + + align:start position:0% +associates, and for our +suppliers. But it opens up a new world + + align:start position:0% +suppliers. But it opens up a new world + + + align:start position:0% +suppliers. But it opens up a new world +of + + align:start position:0% +of + + + align:start position:0% +of +granularity, new windows that we can see + + align:start position:0% +granularity, new windows that we can see + + + align:start position:0% +granularity, new windows that we can see +into the supply chain that we just + + align:start position:0% +into the supply chain that we just + + + align:start position:0% +into the supply chain that we just +didn't realize + + align:start position:0% +didn't realize + + + align:start position:0% +didn't realize +before. We're starting to drive + + align:start position:0% +before. We're starting to drive + + + align:start position:0% +before. We're starting to drive +efficiencies around manual processes, + + align:start position:0% +efficiencies around manual processes, + + + align:start position:0% +efficiencies around manual processes, +but lots of inefficiencies still exist + + align:start position:0% +but lots of inefficiencies still exist + + + align:start position:0% +but lots of inefficiencies still exist +today. + + align:start position:0% +today. + + + align:start position:0% +today. +And a lot of changes will only occur say + + align:start position:0% +And a lot of changes will only occur say + + + align:start position:0% +And a lot of changes will only occur say +in a distribution center once we start + + align:start position:0% +in a distribution center once we start + + + align:start position:0% +in a distribution center once we start +to get a critical mass of product + + align:start position:0% +to get a critical mass of product + + + align:start position:0% +to get a critical mass of product +flowing through those + + align:start position:0% +flowing through those + + + align:start position:0% +flowing through those +facilities. We've got a big opportunity + + align:start position:0% +facilities. We've got a big opportunity + + + align:start position:0% +facilities. We've got a big opportunity +to reduce lead times in the whole supply + + align:start position:0% + + + + align:start position:0% + +chain. So in the short term, as I've + + align:start position:0% +chain. So in the short term, as I've + + + align:start position:0% +chain. So in the short term, as I've +mentioned, we're rolling out handhelds, + + align:start position:0% +mentioned, we're rolling out handhelds, + + + align:start position:0% +mentioned, we're rolling out handhelds, +but the choice of handhelds today is + + align:start position:0% +but the choice of handhelds today is + + + align:start position:0% +but the choice of handhelds today is +limited. The functionality of those + + align:start position:0% +limited. The functionality of those + + + align:start position:0% +limited. The functionality of those +handhelds is limited. + + align:start position:0% +handhelds is limited. + + + align:start position:0% +handhelds is limited. +We need to move to + + align:start position:0% +We need to move to + + + align:start position:0% +We need to move to +wearable mobile + + align:start position:0% + + + + align:start position:0% + +devices systems that help us fasttrack + + align:start position:0% +devices systems that help us fasttrack + + + align:start position:0% +devices systems that help us fasttrack +product to the sales floor. It's always + + align:start position:0% +product to the sales floor. It's always + + + align:start position:0% +product to the sales floor. It's always +that last 50 yards in the store where + + align:start position:0% +that last 50 yards in the store where + + + align:start position:0% +that last 50 yards in the store where +we're most + + align:start position:0% +we're most + + + align:start position:0% +we're most +inefficient. So, how do we get what I + + align:start position:0% +inefficient. So, how do we get what I + + + align:start position:0% +inefficient. So, how do we get what I +would turn oneway stock? It comes in, + + align:start position:0% +would turn oneway stock? It comes in, + + + align:start position:0% +would turn oneway stock? It comes in, +goes straight to the sales floor to the + + align:start position:0% +goes straight to the sales floor to the + + + align:start position:0% +goes straight to the sales floor to the +shelf. It's put on the shelf and the box + + align:start position:0% +shelf. It's put on the shelf and the box + + + align:start position:0% +shelf. It's put on the shelf and the box +is thrown away. We don't get this + + align:start position:0% +is thrown away. We don't get this + + + align:start position:0% +is thrown away. We don't get this +double, treble, quadruple handling back + + align:start position:0% +double, treble, quadruple handling back + + + align:start position:0% +double, treble, quadruple handling back +and forth from the back room to the + + align:start position:0% +and forth from the back room to the + + + align:start position:0% +and forth from the back room to the +sales + + align:start position:0% +sales + + + align:start position:0% +sales +floor. Bill mentioned about execution + + align:start position:0% +floor. Bill mentioned about execution + + + align:start position:0% +floor. Bill mentioned about execution +tools for promotions, new item + + align:start position:0% +tools for promotions, new item + + + align:start position:0% +tools for promotions, new item +launches. So, how can we work more + + align:start position:0% +launches. So, how can we work more + + + align:start position:0% +launches. So, how can we work more +efficiently in that aspect? And that's + + align:start position:0% +efficiently in that aspect? And that's + + + align:start position:0% +efficiently in that aspect? And that's +not just a suppliers responsibility or a + + align:start position:0% +not just a suppliers responsibility or a + + + align:start position:0% +not just a suppliers responsibility or a +retailer's responsibility. It's how do + + align:start position:0% +retailer's responsibility. It's how do + + + align:start position:0% +retailer's responsibility. It's how do +we collaborate together and make that + + align:start position:0% +we collaborate together and make that + + + align:start position:0% +we collaborate together and make that +work? + + align:start position:0% + + + + align:start position:0% + +driving execution. So I mentioned the + + align:start position:0% +driving execution. So I mentioned the + + + align:start position:0% +driving execution. So I mentioned the +new windows and and the the new data + + align:start position:0% +new windows and and the the new data + + + align:start position:0% +new windows and and the the new data +streams that that RFI gives + + align:start position:0% +streams that that RFI gives + + + align:start position:0% +streams that that RFI gives +us. How do we use + + align:start position:0% +us. How do we use + + + align:start position:0% +us. How do we use +that to drive that execution? So in the + + align:start position:0% +that to drive that execution? So in the + + + align:start position:0% +that to drive that execution? So in the +real world today, people tick boxes and + + align:start position:0% +real world today, people tick boxes and + + + align:start position:0% +real world today, people tick boxes and +make reports look pretty and say they've + + align:start position:0% +make reports look pretty and say they've + + + align:start position:0% +make reports look pretty and say they've +done task when they may not have done + + align:start position:0% +done task when they may not have done + + + align:start position:0% +done task when they may not have done +that task. RFID gives us that ability to + + align:start position:0% +that task. RFID gives us that ability to + + + align:start position:0% +that task. RFID gives us that ability to +see whether that task has been done, + + align:start position:0% +see whether that task has been done, + + + align:start position:0% +see whether that task has been done, +whether that new modular has been laid + + align:start position:0% +whether that new modular has been laid + + + align:start position:0% +whether that new modular has been laid +out on the shelf, whether those new + + align:start position:0% +out on the shelf, whether those new + + + align:start position:0% +out on the shelf, whether those new +items have made it out to the shelf + + align:start position:0% +items have made it out to the shelf + + + align:start position:0% +items have made it out to the shelf +without anybody having to go and and + + align:start position:0% +without anybody having to go and and + + + align:start position:0% +without anybody having to go and and +take a a check + + align:start position:0% + + + + align:start position:0% + +sheet. Bill mentioned electronic proof + + align:start position:0% +sheet. Bill mentioned electronic proof + + + align:start position:0% +sheet. Bill mentioned electronic proof +of + + align:start position:0% +of + + + align:start position:0% +of +delivery, big efficiency gain for both + + align:start position:0% +delivery, big efficiency gain for both + + + align:start position:0% +delivery, big efficiency gain for both +the supplier and retailer. + + align:start position:0% +the supplier and retailer. + + + align:start position:0% +the supplier and retailer. +So how do we we make that happen across + + align:start position:0% +So how do we we make that happen across + + + align:start position:0% +So how do we we make that happen across +all retailers, all + + align:start position:0% +all retailers, all + + + align:start position:0% +all retailers, all +suppliers with a common + + align:start position:0% +suppliers with a common + + + align:start position:0% +suppliers with a common +understanding? I mentioned about the + + align:start position:0% +understanding? I mentioned about the + + + align:start position:0% +understanding? I mentioned about the +pallet locator system for + + align:start position:0% +pallet locator system for + + + align:start position:0% +pallet locator system for +SAMs. The benefits we're starting to see + + align:start position:0% +SAMs. The benefits we're starting to see + + + align:start position:0% +SAMs. The benefits we're starting to see +today, as Bill mentioned, it's a very + + align:start position:0% +today, as Bill mentioned, it's a very + + + align:start position:0% +today, as Bill mentioned, it's a very +small sort of subset of products, an + + align:start position:0% +small sort of subset of products, an + + + align:start position:0% +small sort of subset of products, an +area that we've started to change. So + + align:start position:0% +area that we've started to change. So + + + align:start position:0% +area that we've started to change. So +that is truly the tip of the + + align:start position:0% +that is truly the tip of the + + + align:start position:0% +that is truly the tip of the +iceberg. But many benefits are reliant + + align:start position:0% +iceberg. But many benefits are reliant + + + align:start position:0% +iceberg. But many benefits are reliant +on the technology continue to develop + + align:start position:0% +on the technology continue to develop + + + align:start position:0% +on the technology continue to develop +and mature and reducing the cost of + + align:start position:0% +and mature and reducing the cost of + + + align:start position:0% +and mature and reducing the cost of +deployment. So we start to get that + + align:start position:0% +deployment. So we start to get that + + + align:start position:0% +deployment. So we start to get that +critical mass of products flowing + + align:start position:0% +critical mass of products flowing + + + align:start position:0% +critical mass of products flowing +through. Gen two is showing step change + + align:start position:0% +through. Gen two is showing step change + + + align:start position:0% +through. Gen two is showing step change +in performance, a real step change. I + + align:start position:0% +in performance, a real step change. I + + + align:start position:0% +in performance, a real step change. I +know as end users when we came together + + align:start position:0% +know as end users when we came together + + + align:start position:0% +know as end users when we came together +we all said well you know we need a + + align:start position:0% +we all said well you know we need a + + + align:start position:0% +we all said well you know we need a +global tag but it's no point in in + + align:start position:0% +global tag but it's no point in in + + + align:start position:0% +global tag but it's no point in in +developing this this tag if it's just an + + align:start position:0% +developing this this tag if it's just an + + + align:start position:0% +developing this this tag if it's just an +iterative process we need a real step + + align:start position:0% +iterative process we need a real step + + + align:start position:0% +iterative process we need a real step +change and pleas to say Gen two is is + + align:start position:0% +change and pleas to say Gen two is is + + + align:start position:0% +change and pleas to say Gen two is is +delivering that today but we still need + + align:start position:0% +delivering that today but we still need + + + align:start position:0% +delivering that today but we still need +to drive for cheaper faster and added + + align:start position:0% + + + + align:start position:0% + +features. So what are some of the + + align:start position:0% +features. So what are some of the + + + align:start position:0% +features. So what are some of the +barriers to continuing adoption and + + align:start position:0% +barriers to continuing adoption and + + + align:start position:0% +barriers to continuing adoption and +accelerating + + align:start position:0% +accelerating + + + align:start position:0% +accelerating +adoption? I think if you ask most + + align:start position:0% +adoption? I think if you ask most + + + align:start position:0% +adoption? I think if you ask most +suppliers, tag cost + + align:start position:0% +suppliers, tag cost + + + align:start position:0% +suppliers, tag cost +is the primary barrier. + + align:start position:0% +is the primary barrier. + + + align:start position:0% +is the primary barrier. +Many process + + align:start position:0% +Many process + + + align:start position:0% +Many process +efficiencies require that critical mass + + align:start position:0% +efficiencies require that critical mass + + + align:start position:0% +efficiencies require that critical mass +I've spoken about and we need to be + + align:start position:0% +I've spoken about and we need to be + + + align:start position:0% +I've spoken about and we need to be +smart of how we introduce + + align:start position:0% +smart of how we introduce + + + align:start position:0% +smart of how we introduce +RFID into areas so we're not running + + align:start position:0% +RFID into areas so we're not running + + + align:start position:0% +RFID into areas so we're not running +dual + + align:start position:0% +dual + + + align:start position:0% +dual +processes and turning people's worlds + + align:start position:0% +processes and turning people's worlds + + + align:start position:0% +processes and turning people's worlds +upside down. That's what we started to + + align:start position:0% +upside down. That's what we started to + + + align:start position:0% +upside down. That's what we started to +do with our picking + + align:start position:0% +do with our picking + + + align:start position:0% +do with our picking +list. So it's behind the scenes and it's + + align:start position:0% +list. So it's behind the scenes and it's + + + align:start position:0% +list. So it's behind the scenes and it's +just dovetailing with the current + + align:start position:0% +just dovetailing with the current + + + align:start position:0% +just dovetailing with the current +process. And as we move forward, we need + + align:start position:0% +process. And as we move forward, we need + + + align:start position:0% +process. And as we move forward, we need +to minimize the impact on associates + + align:start position:0% +to minimize the impact on associates + + + align:start position:0% +to minimize the impact on associates +throughout the supply chain to enable us + + align:start position:0% +throughout the supply chain to enable us + + + align:start position:0% +throughout the supply chain to enable us +to execute and to get buy + + align:start position:0% +to execute and to get buy + + + align:start position:0% +to execute and to get buy +in. So what are the kind of things that + + align:start position:0% +in. So what are the kind of things that + + + align:start position:0% +in. So what are the kind of things that +that we're looking that that we need to + + align:start position:0% +that we're looking that that we need to + + + align:start position:0% +that we're looking that that we need to +work on and we need to collaborate on? + + align:start position:0% +work on and we need to collaborate on? + + + align:start position:0% +work on and we need to collaborate on? +And it's those transformational + + align:start position:0% +And it's those transformational + + + align:start position:0% +And it's those transformational +changes that Bill spoke about. So sensor + + align:start position:0% +changes that Bill spoke about. So sensor + + + align:start position:0% +changes that Bill spoke about. So sensor +tags seems like we've been talking about + + align:start position:0% +tags seems like we've been talking about + + + align:start position:0% +tags seems like we've been talking about +cold chain compliance and sensor + + align:start position:0% +cold chain compliance and sensor + + + align:start position:0% +cold chain compliance and sensor +tags since a year + + align:start position:0% +tags since a year + + + align:start position:0% +tags since a year +dot and it's not really becoming a + + align:start position:0% +dot and it's not really becoming a + + + align:start position:0% +dot and it's not really becoming a +reality yet. So you look at semipassive + + align:start position:0% +reality yet. So you look at semipassive + + + align:start position:0% +reality yet. So you look at semipassive +tags, they're far too expensive + + align:start position:0% +tags, they're far too expensive + + + align:start position:0% +tags, they're far too expensive +currently to put into a a deployable uh + + align:start position:0% +currently to put into a a deployable uh + + + align:start position:0% +currently to put into a a deployable uh +solution. So we need to move that up a + + align:start position:0% +solution. So we need to move that up a + + + align:start position:0% +solution. So we need to move that up a +notch. + + align:start position:0% +notch. + + + align:start position:0% +notch. +We'll start piloting some proof of + + align:start position:0% +We'll start piloting some proof of + + + align:start position:0% +We'll start piloting some proof of +concepts this year again to to show + + align:start position:0% +concepts this year again to to show + + + align:start position:0% +concepts this year again to to show +everybody what the benefit would + + align:start position:0% +everybody what the benefit would + + + align:start position:0% +everybody what the benefit would +be. But looking at passive temperature + + align:start position:0% +be. But looking at passive temperature + + + align:start position:0% +be. But looking at passive temperature +sensing. So what is a true real business + + align:start position:0% +sensing. So what is a true real business + + + align:start position:0% +sensing. So what is a true real business +case? Is it that we want to with a + + align:start position:0% +case? Is it that we want to with a + + + align:start position:0% +case? Is it that we want to with a +passive uh sensor tag read that + + align:start position:0% +passive uh sensor tag read that + + + align:start position:0% +passive uh sensor tag read that +temperature as it passes certain read + + align:start position:0% +temperature as it passes certain read + + + align:start position:0% +temperature as it passes certain read +points or in a trailer that may have um + + align:start position:0% +points or in a trailer that may have um + + + align:start position:0% +points or in a trailer that may have um +RF equipment on board already for things + + align:start position:0% +RF equipment on board already for things + + + align:start position:0% +RF equipment on board already for things +like GPS that we can tie into. + + align:start position:0% + + + + align:start position:0% + +theft prevention + + align:start position:0% +theft prevention + + + align:start position:0% +theft prevention +systems. A lot of work was done on this + + align:start position:0% +systems. A lot of work was done on this + + + align:start position:0% +systems. A lot of work was done on this +through the auto center and the + + align:start position:0% +through the auto center and the + + + align:start position:0% +through the auto center and the +labs you probably four or five years + + align:start position:0% +labs you probably four or five years + + + align:start position:0% +labs you probably four or five years +ago. But how do we really replace EAS + + align:start position:0% +ago. But how do we really replace EAS + + + align:start position:0% +ago. But how do we really replace EAS +systems because that will start to + + align:start position:0% +systems because that will start to + + + align:start position:0% +systems because that will start to +reduce + + align:start position:0% +reduce + + + align:start position:0% +reduce +costs in that aspect. We can't have EAS + + align:start position:0% +costs in that aspect. We can't have EAS + + + align:start position:0% +costs in that aspect. We can't have EAS +and + + align:start position:0% +and + + + align:start position:0% +and +RFID tags on the same product. + + align:start position:0% +RFID tags on the same product. + + + align:start position:0% +RFID tags on the same product. +because that's just increasing costs. + + align:start position:0% +because that's just increasing costs. + + + align:start position:0% +because that's just increasing costs. +So, how do we get down to one solution + + align:start position:0% +So, how do we get down to one solution + + + align:start position:0% +So, how do we get down to one solution +that will achieve + + align:start position:0% +that will achieve + + + align:start position:0% +that will achieve +both true true sort at high + + align:start position:0% +both true true sort at high + + + align:start position:0% +both true true sort at high +speeds? So, we're close to 600 feet a + + align:start position:0% +speeds? So, we're close to 600 feet a + + + align:start position:0% +speeds? So, we're close to 600 feet a +minute on our sortation systems. How do + + align:start position:0% +minute on our sortation systems. How do + + + align:start position:0% +minute on our sortation systems. How do +we singulate tag reads to know it's that + + align:start position:0% +we singulate tag reads to know it's that + + + align:start position:0% +we singulate tag reads to know it's that +case that needs to go to store 50? + + align:start position:0% + + + + align:start position:0% + +I spoke quite a bit about mobile devices + + align:start position:0% +I spoke quite a bit about mobile devices + + + align:start position:0% +I spoke quite a bit about mobile devices +but robust deployable mobile + + align:start position:0% + + + + align:start position:0% + +devices and + + align:start position:0% + + + + align:start position:0% + +international we need true global tags + + align:start position:0% +international we need true global tags + + + align:start position:0% +international we need true global tags +mentioned about Gen two being a global + + align:start position:0% +mentioned about Gen two being a global + + + align:start position:0% +mentioned about Gen two being a global +solution but I think what you'll see out + + align:start position:0% +solution but I think what you'll see out + + + align:start position:0% +solution but I think what you'll see out +there today with Gen two is those tags + + align:start position:0% +there today with Gen two is those tags + + + align:start position:0% +there today with Gen two is those tags +are tuned to each geographic area so the + + align:start position:0% +are tuned to each geographic area so the + + + align:start position:0% +are tuned to each geographic area so the +tags that we're testing + + align:start position:0% +tags that we're testing + + + align:start position:0% +tags that we're testing +here I'm sure are tuned + + align:start position:0% +here I'm sure are tuned + + + align:start position:0% +here I'm sure are tuned +to the US. The tags that we're testing + + align:start position:0% +to the US. The tags that we're testing + + + align:start position:0% +to the US. The tags that we're testing +in Europe are tuned to + + align:start position:0% +in Europe are tuned to + + + align:start position:0% +in Europe are tuned to +Europe. That's not going to work. That + + align:start position:0% +Europe. That's not going to work. That + + + align:start position:0% +Europe. That's not going to work. That +wasn't the idea of Gen + + align:start position:0% +wasn't the idea of Gen + + + align:start position:0% +wasn't the idea of Gen +Two. So, we need to to tune the + + align:start position:0% +Two. So, we need to to tune the + + + align:start position:0% +Two. So, we need to to tune the +tags to to one sort of format that will + + align:start position:0% +tags to to one sort of format that will + + + align:start position:0% +tags to to one sort of format that will +work around the + + align:start position:0% +work around the + + + align:start position:0% +work around the +world. And we need to move the EPC + + align:start position:0% +world. And we need to move the EPC + + + align:start position:0% +world. And we need to move the EPC +network from theory and powerpoints into + + align:start position:0% +network from theory and powerpoints into + + + align:start position:0% +network from theory and powerpoints into +reality. + + align:start position:0% + + + + align:start position:0% + +a lot of talk about farmer and I think + + align:start position:0% +a lot of talk about farmer and I think + + + align:start position:0% +a lot of talk about farmer and I think +there was a a separate session yesterday + + align:start position:0% +there was a a separate session yesterday + + + align:start position:0% +there was a a separate session yesterday +on farmer which uh I wasn't able to + + align:start position:0% +on farmer which uh I wasn't able to + + + align:start position:0% +on farmer which uh I wasn't able to +make but in the UHF space you know + + align:start position:0% +make but in the UHF space you know + + + align:start position:0% +make but in the UHF space you know +there's been a lot of focus on case and + + align:start position:0% +there's been a lot of focus on case and + + + align:start position:0% +there's been a lot of focus on case and +pallet and large form factors of + + align:start position:0% +pallet and large form factors of + + + align:start position:0% +pallet and large form factors of +tags little emphasis on the small form + + align:start position:0% +tags little emphasis on the small form + + + align:start position:0% +tags little emphasis on the small form +factors but we need to to work on that + + align:start position:0% +factors but we need to to work on that + + + align:start position:0% +factors but we need to to work on that +there's initiatives uh happening right + + align:start position:0% +there's initiatives uh happening right + + + align:start position:0% +there's initiatives uh happening right +now showing some good results in labs + + align:start position:0% +now showing some good results in labs + + + align:start position:0% +now showing some good results in labs +but again we need to move this out to to + + align:start position:0% +but again we need to move this out to to + + + align:start position:0% +but again we need to move this out to to +the field to get real world + + align:start position:0% +the field to get real world + + + align:start position:0% +the field to get real world +learning and then have the proper debate + + align:start position:0% +learning and then have the proper debate + + + align:start position:0% +learning and then have the proper debate +whether HF or UHF is a correct method to + + align:start position:0% +whether HF or UHF is a correct method to + + + align:start position:0% +whether HF or UHF is a correct method to +to move forward + + align:start position:0% +to move forward + + + align:start position:0% +to move forward +with and a big need not just for pharma + + align:start position:0% +with and a big need not just for pharma + + + align:start position:0% +with and a big need not just for pharma +but other areas as well for + + align:start position:0% +but other areas as well for + + + align:start position:0% +but other areas as well for +security you know so what are the + + align:start position:0% +security you know so what are the + + + align:start position:0% +security you know so what are the +security measures that we would want and + + align:start position:0% +security measures that we would want and + + + align:start position:0% +security measures that we would want and +need on such + + align:start position:0% + + + + align:start position:0% + +products mentioned about international + + align:start position:0% +products mentioned about international + + + align:start position:0% +products mentioned about international +and the EPC + + align:start position:0% +and the EPC + + + align:start position:0% +and the EPC +network and direction. This is probably + + align:start position:0% +network and direction. This is probably + + + align:start position:0% +network and direction. This is probably +my number one um objective for this + + align:start position:0% +my number one um objective for this + + + align:start position:0% +my number one um objective for this +year is through RFID to sense direction. + + align:start position:0% +year is through RFID to sense direction. + + + align:start position:0% +year is through RFID to sense direction. +So, Bill mentioned about read rates, you + + align:start position:0% +So, Bill mentioned about read rates, you + + + align:start position:0% +So, Bill mentioned about read rates, you +know, not 100% and we don't need them to + + align:start position:0% +know, not 100% and we don't need them to + + + align:start position:0% +know, not 100% and we don't need them to +be 100% today, but having direction, + + align:start position:0% +be 100% today, but having direction, + + + align:start position:0% +be 100% today, but having direction, +knowing that something is either leaving + + align:start position:0% +knowing that something is either leaving + + + align:start position:0% +knowing that something is either leaving +this room or coming into this + + align:start position:0% +this room or coming into this + + + align:start position:0% +this room or coming into this +room then actually gives us much more + + align:start position:0% +room then actually gives us much more + + + align:start position:0% +room then actually gives us much more +accurate data than we have today. + + align:start position:0% +accurate data than we have today. + + + align:start position:0% +accurate data than we have today. +The last thing I want to do is tell an + + align:start position:0% +The last thing I want to do is tell an + + + align:start position:0% +The last thing I want to do is tell an +associate to go and pick a case that's + + align:start position:0% +associate to go and pick a case that's + + + align:start position:0% +associate to go and pick a case that's +sat in the back + + align:start position:0% +sat in the back + + + align:start position:0% +sat in the back +room of a store and they go there and + + align:start position:0% +room of a store and they go there and + + + align:start position:0% +room of a store and they go there and +it's not not there can't be found. That + + align:start position:0% +it's not not there can't be found. That + + + align:start position:0% +it's not not there can't be found. That +discredits the whole system. So the + + align:start position:0% +discredits the whole system. So the + + + align:start position:0% +discredits the whole system. So the +cleaner data we can get then the better + + align:start position:0% +cleaner data we can get then the better + + + align:start position:0% +cleaner data we can get then the better +position we are the better execution + + align:start position:0% +position we are the better execution + + + align:start position:0% +position we are the better execution +we'll get and direction will give us + + align:start position:0% +we'll get and direction will give us + + + align:start position:0% +we'll get and direction will give us +that. And there's various uh theories + + align:start position:0% +that. And there's various uh theories + + + align:start position:0% +that. And there's various uh theories +and uh solutions thrown out there from + + align:start position:0% +and uh solutions thrown out there from + + + align:start position:0% +and uh solutions thrown out there from +using RFID and complimentary + + align:start position:0% +using RFID and complimentary + + + align:start position:0% +using RFID and complimentary +technologies such as sensors that we + + align:start position:0% +technologies such as sensors that we + + + align:start position:0% +technologies such as sensors that we +could use or things like the Doppler + + align:start position:0% +could use or things like the Doppler + + + align:start position:0% +could use or things like the Doppler +effect that we could use through through + + align:start position:0% +effect that we could use through through + + + align:start position:0% +effect that we could use through through +readers, but really need to get out + + align:start position:0% +readers, but really need to get out + + + align:start position:0% +readers, but really need to get out +there and try four or five the four or + + align:start position:0% +there and try four or five the four or + + + align:start position:0% +there and try four or five the four or +five of these different methods to see + + align:start position:0% +five of these different methods to see + + + align:start position:0% +five of these different methods to see +which is most appropriate and cost + + align:start position:0% +which is most appropriate and cost + + + align:start position:0% +which is most appropriate and cost +effective. + + align:start position:0% +effective. + + + align:start position:0% +effective. +And then some of the holy grails, + + align:start position:0% +And then some of the holy grails, + + + align:start position:0% +And then some of the holy grails, +reading all cases on a + + align:start position:0% +reading all cases on a + + + align:start position:0% +reading all cases on a +pallet, not possible + + align:start position:0% +pallet, not possible + + + align:start position:0% +pallet, not possible +today, but how can we achieve that in + + align:start position:0% +today, but how can we achieve that in + + + align:start position:0% +today, but how can we achieve that in +the future? And how do we get to the sub + + align:start position:0% +the future? And how do we get to the sub + + + align:start position:0% +the future? And how do we get to the sub +5 cent + + align:start position:0% +5 cent + + + align:start position:0% +5 cent +tag so that the automated checkout + + align:start position:0% +tag so that the automated checkout + + + align:start position:0% +tag so that the automated checkout +becomes a reality in the + + align:start position:0% + + + + align:start position:0% + +future? What do we need to keep doing? + + align:start position:0% +future? What do we need to keep doing? + + + align:start position:0% +future? What do we need to keep doing? +We need to keep educating. + + align:start position:0% +We need to keep educating. + + + align:start position:0% +We need to keep educating. +We need to keep educating governing + + align:start position:0% +We need to keep educating governing + + + align:start position:0% +We need to keep educating governing +bodies around the world so that Gen 2 is + + align:start position:0% +bodies around the world so that Gen 2 is + + + align:start position:0% +bodies around the world so that Gen 2 is +endorsed in every region, every + + align:start position:0% +endorsed in every region, every + + + align:start position:0% +endorsed in every region, every +country so that global tag can be + + align:start position:0% +country so that global tag can be + + + align:start position:0% +country so that global tag can be +used. We need to educate end users what + + align:start position:0% +used. We need to educate end users what + + + align:start position:0% +used. We need to educate end users what +are the benefits of RFID, how best to + + align:start position:0% +are the benefits of RFID, how best to + + + align:start position:0% +are the benefits of RFID, how best to +deploy it, where to start. There's some + + align:start position:0% +deploy it, where to start. There's some + + + align:start position:0% +deploy it, where to start. There's some +great work being done in this area + + align:start position:0% +great work being done in this area + + + align:start position:0% +great work being done in this area +already. And as Bill mentioned, + + align:start position:0% +already. And as Bill mentioned, + + + align:start position:0% +already. And as Bill mentioned, +developing and nurturing people + + align:start position:0% +developing and nurturing people + + + align:start position:0% +developing and nurturing people +today to help in the future + + align:start position:0% +today to help in the future + + + align:start position:0% +today to help in the future +uh build these systems and manage these + + align:start position:0% +uh build these systems and manage these + + + align:start position:0% +uh build these systems and manage these +systems and quality + + align:start position:0% +systems and quality + + + align:start position:0% +systems and quality +improvements. So cost isn't just about + + align:start position:0% +improvements. So cost isn't just about + + + align:start position:0% +improvements. So cost isn't just about +this tag's costing me 12 + + align:start position:0% + + + + align:start position:0% + +cents. Yield rates are important too + + align:start position:0% +cents. Yield rates are important too + + + align:start position:0% +cents. Yield rates are important too +because that c cost gets passed on + + align:start position:0% +because that c cost gets passed on + + + align:start position:0% +because that c cost gets passed on +somewhere down the + + align:start position:0% +somewhere down the + + + align:start position:0% +somewhere down the +line. and testing testing for true + + align:start position:0% +line. and testing testing for true + + + align:start position:0% +line. and testing testing for true +interoperability. Testing for what is + + align:start position:0% +interoperability. Testing for what is + + + align:start position:0% +interoperability. Testing for what is +the best tag or the antenna design for + + align:start position:0% +the best tag or the antenna design for + + + align:start position:0% +the best tag or the antenna design for +that product that you're shipping. + + align:start position:0% +that product that you're shipping. + + + align:start position:0% +that product that you're shipping. +Bill shared with me a while ago an + + align:start position:0% +Bill shared with me a while ago an + + + align:start position:0% +Bill shared with me a while ago an +interesting story from a supplier where + + align:start position:0% +interesting story from a supplier where + + + align:start position:0% +interesting story from a supplier where +there it was two cases of a product, one + + align:start position:0% +there it was two cases of a product, one + + + align:start position:0% +there it was two cases of a product, one +of our suppliers, and uh it was the same + + align:start position:0% +of our suppliers, and uh it was the same + + + align:start position:0% +of our suppliers, and uh it was the same +product except a different flavor and uh + + align:start position:0% +product except a different flavor and uh + + + align:start position:0% +product except a different flavor and uh +they were getting good read rates on one + + align:start position:0% +they were getting good read rates on one + + + align:start position:0% +they were getting good read rates on one +and poor read rates on the other and + + align:start position:0% +and poor read rates on the other and + + + align:start position:0% +and poor read rates on the other and +couldn't understand why why that was and + + align:start position:0% +couldn't understand why why that was and + + + align:start position:0% +couldn't understand why why that was and +uh went along to Bill and said, "Can you + + align:start position:0% +uh went along to Bill and said, "Can you + + + align:start position:0% +uh went along to Bill and said, "Can you +help us with this?" + + align:start position:0% +help us with this?" + + + align:start position:0% +help us with this?" +And after some trial and error and + + align:start position:0% +And after some trial and error and + + + align:start position:0% +And after some trial and error and +swapping the product between the two + + align:start position:0% +swapping the product between the two + + + align:start position:0% +swapping the product between the two +boxes, found out that one of the flavors + + align:start position:0% +boxes, found out that one of the flavors + + + align:start position:0% +boxes, found out that one of the flavors +had some metallic paint within the + + align:start position:0% +had some metallic paint within the + + + align:start position:0% +had some metallic paint within the +packaging. And it was that that was that + + align:start position:0% +packaging. And it was that that was that + + + align:start position:0% +packaging. And it was that that was that +was causing the uh poor read rate on + + align:start position:0% +was causing the uh poor read rate on + + + align:start position:0% +was causing the uh poor read rate on +that second product. So to a supplier, + + align:start position:0% +that second product. So to a supplier, + + + align:start position:0% +that second product. So to a supplier, +it was the same product, the same same + + align:start position:0% +it was the same product, the same same + + + align:start position:0% +it was the same product, the same same +packaging as they thought, same density + + align:start position:0% +packaging as they thought, same density + + + align:start position:0% +packaging as they thought, same density +of product inside, but two different + + align:start position:0% +of product inside, but two different + + + align:start position:0% +of product inside, but two different +results. + + align:start position:0% +results. + + + align:start position:0% +results. +And so how can we uh test and get best + + align:start position:0% +And so how can we uh test and get best + + + align:start position:0% +And so how can we uh test and get best +practice out there and so every supplier + + align:start position:0% +practice out there and so every supplier + + + align:start position:0% +practice out there and so every supplier +doesn't have to go through that learning + + align:start position:0% +doesn't have to go through that learning + + + align:start position:0% +doesn't have to go through that learning +process because that reduces costs + + align:start position:0% + + + + align:start position:0% + +overall. And then we should all be + + align:start position:0% +overall. And then we should all be + + + align:start position:0% +overall. And then we should all be +mindful that you know as we move forward + + align:start position:0% +mindful that you know as we move forward + + + align:start position:0% +mindful that you know as we move forward +as we move forward to the sales floor to + + align:start position:0% +as we move forward to the sales floor to + + + align:start position:0% +as we move forward to the sales floor to +items to theft prevention that we need + + align:start position:0% +items to theft prevention that we need + + + align:start position:0% +items to theft prevention that we need +to ensure that privacy concerns are + + align:start position:0% +to ensure that privacy concerns are + + + align:start position:0% +to ensure that privacy concerns are +taken into account and addressed. + + align:start position:0% +taken into account and addressed. + + + align:start position:0% +taken into account and addressed. +This should only equal lowering the cost + + align:start position:0% +This should only equal lowering the cost + + + align:start position:0% +This should only equal lowering the cost +of + + align:start position:0% +of + + + align:start position:0% +of +implementation. So just to wrap + + align:start position:0% +implementation. So just to wrap + + + align:start position:0% +implementation. So just to wrap +up, we're just scratching the surface + + align:start position:0% +up, we're just scratching the surface + + + align:start position:0% +up, we're just scratching the surface +today. We need to get mobile devices out + + align:start position:0% +today. We need to get mobile devices out + + + align:start position:0% +today. We need to get mobile devices out +there so that people can go about their + + align:start position:0% +there so that people can go about their + + + align:start position:0% +there so that people can go about their +everyday job and the system is just + + align:start position:0% +everyday job and the system is just + + + align:start position:0% +everyday job and the system is just +talking to them and give them work to do + + align:start position:0% +talking to them and give them work to do + + + align:start position:0% +talking to them and give them work to do +in a prioritized way. We need to lower + + align:start position:0% +in a prioritized way. We need to lower + + + align:start position:0% +in a prioritized way. We need to lower +the cost of deployment. + + align:start position:0% +the cost of deployment. + + + align:start position:0% +the cost of deployment. +And then finally, we should never lose a + + align:start position:0% +And then finally, we should never lose a + + + align:start position:0% +And then finally, we should never lose a +sight of of why we're using this + + align:start position:0% +sight of of why we're using this + + + align:start position:0% +sight of of why we're using this +technology, why we're pushing this + + align:start position:0% +technology, why we're pushing this + + + align:start position:0% +technology, why we're pushing this +technology and driving forward. It's all + + align:start position:0% +technology and driving forward. It's all + + + align:start position:0% +technology and driving forward. It's all +about the customer at the end of the + + align:start position:0% +about the customer at the end of the + + + align:start position:0% +about the customer at the end of the +day. So whether you're a supplier or + + align:start position:0% +day. So whether you're a supplier or + + + align:start position:0% +day. So whether you're a supplier or +retailer, at the end of the day, we need + + align:start position:0% +retailer, at the end of the day, we need + + + align:start position:0% +retailer, at the end of the day, we need +to service our customers better. Whether + + align:start position:0% +to service our customers better. Whether + + + align:start position:0% +to service our customers better. Whether +that's working more efficiently and + + align:start position:0% +that's working more efficiently and + + + align:start position:0% +that's working more efficiently and +taking cost out of the supply chain that + + align:start position:0% +taking cost out of the supply chain that + + + align:start position:0% +taking cost out of the supply chain that +then can be passed on to the customer, + + align:start position:0% +then can be passed on to the customer, + + + align:start position:0% +then can be passed on to the customer, +that's our end goal. Thank you. \ No newline at end of file diff --git a/oLIMFmEgaWo.txt b/oLIMFmEgaWo.txt new file mode 100644 index 0000000000000000000000000000000000000000..9d8ab9df4cc36055572e01c93ad691db32f7eda7 --- /dev/null +++ b/oLIMFmEgaWo.txt @@ -0,0 +1,2307 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay most of the hour we'll + + align:start position:0% +ocw.mit.edu okay most of the hour we'll + + + align:start position:0% +ocw.mit.edu okay most of the hour we'll +be watching the first half of the uh the + + align:start position:0% +be watching the first half of the uh the + + + align:start position:0% +be watching the first half of the uh the +video on chimpanzees but yeah I wanted + + align:start position:0% +video on chimpanzees but yeah I wanted + + + align:start position:0% +video on chimpanzees but yeah I wanted +to finish + + align:start position:0% +to finish + + + align:start position:0% +to finish +uh Revis I revised a little bit on motor + + align:start position:0% +uh Revis I revised a little bit on motor + + + align:start position:0% +uh Revis I revised a little bit on motor +learning to try to make it clear what + + align:start position:0% +learning to try to make it clear what + + + align:start position:0% +learning to try to make it clear what +I'm trying to get across so let's just + + align:start position:0% +I'm trying to get across so let's just + + + align:start position:0% +I'm trying to get across so let's just +go through motor learning again this + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the acquisition of path habits I talked + + align:start position:0% +the acquisition of path habits I talked + + + align:start position:0% +the acquisition of path habits I talked +about but the main point here is that + + align:start position:0% +about but the main point here is that + + + align:start position:0% +about but the main point here is that +the movements acquired independence from + + align:start position:0% +the movements acquired independence from + + + align:start position:0% +the movements acquired independence from +sensory input so it's not that they're + + align:start position:0% +sensory input so it's not that they're + + + align:start position:0% +sensory input so it's not that they're +continually responding to things all + + align:start position:0% +continually responding to things all + + + align:start position:0% +continually responding to things all +along their path if if it becomes + + align:start position:0% +along their path if if it becomes + + + align:start position:0% +along their path if if it becomes +learned in the motor system they just + + align:start position:0% +learned in the motor system they just + + + align:start position:0% +learned in the motor system they just +run it off like like a fixed motor + + align:start position:0% +run it off like like a fixed motor + + + align:start position:0% +run it off like like a fixed motor +pattern you'll remember when we talked + + align:start position:0% +pattern you'll remember when we talked + + + align:start position:0% +pattern you'll remember when we talked +about fix action patterns in bir the the + + align:start position:0% +about fix action patterns in bir the the + + + align:start position:0% +about fix action patterns in bir the the +geese and Ducks the way roll the eggs in + + align:start position:0% +geese and Ducks the way roll the eggs in + + + align:start position:0% +geese and Ducks the way roll the eggs in +if you interrupt it you + + align:start position:0% +if you interrupt it you + + + align:start position:0% +if you interrupt it you +know they need they just have to start + + align:start position:0% +know they need they just have to start + + + align:start position:0% +know they need they just have to start +all over again if they going to do it at + + align:start position:0% +all over again if they going to do it at + + + align:start position:0% +all over again if they going to do it at +all it's a single pattern and that's + + align:start position:0% +all it's a single pattern and that's + + + align:start position:0% +all it's a single pattern and that's +what these path this path learning + + align:start position:0% +what these path this path learning + + + align:start position:0% +what these path this path learning +amounts + + align:start position:0% +amounts + + + align:start position:0% +amounts +to it becomes encoded in the + + align:start position:0% +to it becomes encoded in the + + + align:start position:0% +to it becomes encoded in the +cerebellum okay so it's like when you + + align:start position:0% +cerebellum okay so it's like when you + + + align:start position:0% +cerebellum okay so it's like when you +recite something from memory or learn to + + align:start position:0% +recite something from memory or learn to + + + align:start position:0% +recite something from memory or learn to +play a musical instrument you probably + + align:start position:0% +play a musical instrument you probably + + + align:start position:0% +play a musical instrument you probably +have all had the experience of you're + + align:start position:0% +have all had the experience of you're + + + align:start position:0% +have all had the experience of you're +reciting something and you don't have it + + align:start position:0% +reciting something and you don't have it + + + align:start position:0% +reciting something and you don't have it +quite learned perfectly so you get stuck + + align:start position:0% +quite learned perfectly so you get stuck + + + align:start position:0% +quite learned perfectly so you get stuck +and then to remember it you have to go + + align:start position:0% +and then to remember it you have to go + + + align:start position:0% +and then to remember it you have to go +back either to the beginning or to + + align:start position:0% +back either to the beginning or to + + + align:start position:0% +back either to the beginning or to +some chunk beginning of some chunk + + align:start position:0% +some chunk beginning of some chunk + + + align:start position:0% +some chunk beginning of some chunk +before you can do it that's because + + align:start position:0% +before you can do it that's because + + + align:start position:0% +before you can do it that's because +you've learned it if you memorize + + align:start position:0% +you've learned it if you memorize + + + align:start position:0% +you've learned it if you memorize +something it often becomes motor + + align:start position:0% +something it often becomes motor + + + align:start position:0% +something it often becomes motor +learning okay so and it acquires some + + align:start position:0% +learning okay so and it acquires some + + + align:start position:0% +learning okay so and it acquires some +similarities to the motor component of + + align:start position:0% +similarities to the motor component of + + + align:start position:0% +similarities to the motor component of +fix action + + align:start position:0% + + + + align:start position:0% + +patterns um as I mention here and then + + align:start position:0% +patterns um as I mention here and then + + + align:start position:0% +patterns um as I mention here and then +it's it's very resistant to change and + + align:start position:0% +it's it's very resistant to change and + + + align:start position:0% +it's it's very resistant to change and +perhaps most interesting is that in many + + align:start position:0% +perhaps most interesting is that in many + + + align:start position:0% +perhaps most interesting is that in many +cases it seems to acquire its own uh + + align:start position:0% +cases it seems to acquire its own uh + + + align:start position:0% +cases it seems to acquire its own uh +action specific potential that is it + + align:start position:0% +action specific potential that is it + + + align:start position:0% +action specific potential that is it +requires a motivation the animal to do + + align:start position:0% +requires a motivation the animal to do + + + align:start position:0% +requires a motivation the animal to do +it or the person it usually requires a + + align:start position:0% +it or the person it usually requires a + + + align:start position:0% +it or the person it usually requires a +lot of repetition is like when you learn + + align:start position:0% +lot of repetition is like when you learn + + + align:start position:0% +lot of repetition is like when you learn +skills in + + align:start position:0% +skills in + + + align:start position:0% +skills in +sport we talked about the difference in + + align:start position:0% +sport we talked about the difference in + + + align:start position:0% +sport we talked about the difference in +Locomotion between these different + + align:start position:0% +Locomotion between these different + + + align:start position:0% +Locomotion between these different +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ulates and what surf footedness is it's + + align:start position:0% +ulates and what surf footedness is it's + + + align:start position:0% +ulates and what surf footedness is it's +an example of the more surefooted + + align:start position:0% +an example of the more surefooted + + + align:start position:0% +an example of the more surefooted +animals simply there's more separate + + align:start position:0% +animals simply there's more separate + + + align:start position:0% +animals simply there's more separate +elements in their action + + align:start position:0% +elements in their action + + + align:start position:0% +elements in their action +pattern so more subject we would say to + + align:start position:0% +pattern so more subject we would say to + + + align:start position:0% +pattern so more subject we would say to +subject to voluntary control they can + + align:start position:0% +subject to voluntary control they can + + + align:start position:0% +subject to voluntary control they can +decide to use + + align:start position:0% +decide to use + + + align:start position:0% +decide to use +it and so I've rewarded this just a + + align:start position:0% +it and so I've rewarded this just a + + + align:start position:0% +it and so I've rewarded this just a +little bit to help you understand what + + align:start position:0% +little bit to help you understand what + + + align:start position:0% +little bit to help you understand what +that's all about and + + align:start position:0% +that's all about and + + + align:start position:0% +that's all about and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the + + align:start position:0% + + + + align:start position:0% + +uh but I think it's it's clear enough + + align:start position:0% +uh but I think it's it's clear enough + + + align:start position:0% +uh but I think it's it's clear enough +with that + + align:start position:0% + + + + align:start position:0% + +and I wanted to add this + + align:start position:0% + + + + align:start position:0% + +uh about the exploratory uh sorry what + + align:start position:0% +uh about the exploratory uh sorry what + + + align:start position:0% +uh about the exploratory uh sorry what +did I do + + align:start position:0% +did I do + + + align:start position:0% +did I do +here oh this got out of place okay this + + align:start position:0% +here oh this got out of place okay this + + + align:start position:0% +here oh this got out of place okay this +belongs with discussion of voluntary + + align:start position:0% +belongs with discussion of voluntary + + + align:start position:0% +belongs with discussion of voluntary +Behavior animals that have evolved + + align:start position:0% +Behavior animals that have evolved + + + align:start position:0% +Behavior animals that have evolved +direct axonal projections from the + + align:start position:0% +direct axonal projections from the + + + align:start position:0% +direct axonal projections from the +neocortex to the motor + + align:start position:0% +neocortex to the motor + + + align:start position:0% +neocortex to the motor +neurons uh there aren't all that many + + align:start position:0% +neurons uh there aren't all that many + + + align:start position:0% +neurons uh there aren't all that many +but but higher primates have that + + align:start position:0% +but but higher primates have that + + + align:start position:0% +but but higher primates have that +raccoons have it uh a few other species + + align:start position:0% +raccoons have it uh a few other species + + + align:start position:0% +raccoons have it uh a few other species +then the unit of movement is just the + + align:start position:0% +then the unit of movement is just the + + + align:start position:0% +then the unit of movement is just the +digital movement now that's the smallest + + align:start position:0% +digital movement now that's the smallest + + + align:start position:0% +digital movement now that's the smallest +unit you can get and and animals that + + align:start position:0% +unit you can get and and animals that + + + align:start position:0% +unit you can get and and animals that +have that like us you know yes we have + + align:start position:0% +have that like us you know yes we have + + + align:start position:0% +have that like us you know yes we have +voluntary control over individual digits + + align:start position:0% +voluntary control over individual digits + + + align:start position:0% +voluntary control over individual digits +we someone can tell you can you move + + align:start position:0% +we someone can tell you can you move + + + align:start position:0% +we someone can tell you can you move +just you know your little finger and you + + align:start position:0% +just you know your little finger and you + + + align:start position:0% +just you know your little finger and you +can do it we can't do it very well for + + align:start position:0% +can do it we can't do it very well for + + + align:start position:0% +can do it we can't do it very well for +the fourth finger but in general we have + + align:start position:0% +the fourth finger but in general we have + + + align:start position:0% +the fourth finger but in general we have +that kind of control but most movements + + align:start position:0% +that kind of control but most movements + + + align:start position:0% +that kind of control but most movements +are not that we can't control just + + align:start position:0% +are not that we can't control just + + + align:start position:0% +are not that we can't control just +individual set of muscles like that most + + align:start position:0% +individual set of muscles like that most + + + align:start position:0% +individual set of muscles like that most +movements + + align:start position:0% +movements + + + align:start position:0% +movements +uh we don't have that kind of voluntary + + align:start position:0% +uh we don't have that kind of voluntary + + + align:start position:0% +uh we don't have that kind of voluntary +control + + align:start position:0% +control + + + align:start position:0% +control +over and that uh is true for other + + align:start position:0% +over and that uh is true for other + + + align:start position:0% +over and that uh is true for other +animals of course even + + align:start position:0% +animals of course even + + + align:start position:0% +animals of course even +more + + align:start position:0% +more + + + align:start position:0% +more +and I mentioned here that you know I + + align:start position:0% +and I mentioned here that you know I + + + align:start position:0% +and I mentioned here that you know I +talk about these projections from motor + + align:start position:0% +talk about these projections from motor + + + align:start position:0% +talk about these projections from motor +cortex and or the motor areas of Cortex + + align:start position:0% +cortex and or the motor areas of Cortex + + + align:start position:0% +cortex and or the motor areas of Cortex +in a mammal but if you talk about birds + + align:start position:0% +in a mammal but if you talk about birds + + + align:start position:0% +in a mammal but if you talk about birds +they don't have a neocortex but they + + align:start position:0% +they don't have a neocortex but they + + + align:start position:0% +they don't have a neocortex but they +have equivalent structures especially + + align:start position:0% +have equivalent structures especially + + + align:start position:0% +have equivalent structures especially +this hyper palum region and it becomes + + align:start position:0% +this hyper palum region and it becomes + + + align:start position:0% +this hyper palum region and it becomes +so welldeveloped and the more advanced + + align:start position:0% +so welldeveloped and the more advanced + + + align:start position:0% +so welldeveloped and the more advanced +birds like the corvids parrots uh it + + align:start position:0% +birds like the corvids parrots uh it + + + align:start position:0% +birds like the corvids parrots uh it +forms a bulge and they actually have a + + align:start position:0% +forms a bulge and they actually have a + + + align:start position:0% +forms a bulge and they actually have a +motor + + align:start position:0% +motor + + + align:start position:0% +motor +wolst they have aat of sensory wolst a + + align:start position:0% +wolst they have aat of sensory wolst a + + + align:start position:0% +wolst they have aat of sensory wolst a +visual wolst okay that's the equivalent + + align:start position:0% +visual wolst okay that's the equivalent + + + align:start position:0% +visual wolst okay that's the equivalent +to those areas and they also have these + + align:start position:0% +to those areas and they also have these + + + align:start position:0% +to those areas and they also have these +direct projections to the spinal cord um + + align:start position:0% +direct projections to the spinal cord um + + + align:start position:0% +direct projections to the spinal cord um +I'm not sure if they go directly to + + align:start position:0% +I'm not sure if they go directly to + + + align:start position:0% +I'm not sure if they go directly to +motor neurons as they do in higher + + align:start position:0% +motor neurons as they do in higher + + + align:start position:0% +motor neurons as they do in higher +primates uh but uh that's + + align:start position:0% +primates uh but uh that's + + + align:start position:0% +primates uh but uh that's +possible so okay + + align:start position:0% + + + + align:start position:0% + +uh although I rewarded this a little bit + + align:start position:0% +uh although I rewarded this a little bit + + + align:start position:0% +uh although I rewarded this a little bit +we talked about exploratory behavior and + + align:start position:0% +we talked about exploratory behavior and + + + align:start position:0% +we talked about exploratory behavior and +curiosity before so I don't think we + + align:start position:0% +curiosity before so I don't think we + + + align:start position:0% +curiosity before so I don't think we +have to go through + + align:start position:0% +have to go through + + + align:start position:0% +have to go through +that I just want to point out here in + + align:start position:0% +that I just want to point out here in + + + align:start position:0% +that I just want to point out here in +the functions of play he actually + + align:start position:0% +the functions of play he actually + + + align:start position:0% +the functions of play he actually +introduced introduces what amounts to + + align:start position:0% +introduced introduces what amounts to + + + align:start position:0% +introduced introduces what amounts to +three additional types of + + align:start position:0% +three additional types of + + + align:start position:0% +three additional types of +learning U all learned in place so they + + align:start position:0% +learning U all learned in place so they + + + align:start position:0% +learning U all learned in place so they +amount to a different kind of learning + + align:start position:0% +amount to a different kind of learning + + + align:start position:0% +amount to a different kind of learning +than learned in other situations so I + + align:start position:0% +than learned in other situations so I + + + align:start position:0% +than learned in other situations so I +list them + + align:start position:0% +list them + + + align:start position:0% +list them +there and then we talked about research + + align:start position:0% +there and then we talked about research + + + align:start position:0% +there and then we talked about research +in art in humans but that's where we + + align:start position:0% +in art in humans but that's where we + + + align:start position:0% +in art in humans but that's where we +ended yesterday and you can go through + + align:start position:0% +ended yesterday and you can go through + + + align:start position:0% +ended yesterday and you can go through +all these different kinds of learning + + align:start position:0% +all these different kinds of learning + + + align:start position:0% +all these different kinds of learning +and a + + align:start position:0% +and a + + + align:start position:0% +and a +neuroscientist uh can relate them to + + align:start position:0% +neuroscientist uh can relate them to + + + align:start position:0% +neuroscientist uh can relate them to +specific + + align:start position:0% +specific + + + align:start position:0% +specific +structures um for example the + + align:start position:0% +structures um for example the + + + align:start position:0% +structures um for example the +habituation and sensitization the these + + align:start position:0% +habituation and sensitization the these + + + align:start position:0% +habituation and sensitization the these +Learning Without + + align:start position:0% +Learning Without + + + align:start position:0% +Learning Without +Association + + align:start position:0% +Association + + + align:start position:0% +Association +uh it can even happen in in spinal + + align:start position:0% +uh it can even happen in in spinal + + + align:start position:0% +uh it can even happen in in spinal +Pathways uh so all the sensory and motor + + align:start position:0% +Pathways uh so all the sensory and motor + + + align:start position:0% +Pathways uh so all the sensory and motor +pathways can can be subject to that kind + + align:start position:0% +pathways can can be subject to that kind + + + align:start position:0% +pathways can can be subject to that kind +of + + align:start position:0% +of + + + align:start position:0% +of +change uh the other things of interest + + align:start position:0% +change uh the other things of interest + + + align:start position:0% +change uh the other things of interest +are + + align:start position:0% + + + + align:start position:0% + +the not just the cerebellar mechanisms + + align:start position:0% +the not just the cerebellar mechanisms + + + align:start position:0% +the not just the cerebellar mechanisms +for motor learning but for uh these + + align:start position:0% +for motor learning but for uh these + + + align:start position:0% +for motor learning but for uh these +simple habit formation including + + align:start position:0% +simple habit formation including + + + align:start position:0% +simple habit formation including +avoidance responses learned through + + align:start position:0% +avoidance responses learned through + + + align:start position:0% +avoidance responses learned through +trauma they involve the Corpus + + align:start position:0% +trauma they involve the Corpus + + + align:start position:0% +trauma they involve the Corpus +trium responsible for many habits it's + + align:start position:0% +trium responsible for many habits it's + + + align:start position:0% +trium responsible for many habits it's +especially true of a this type of a + + align:start position:0% +especially true of a this type of a + + + align:start position:0% +especially true of a this type of a +learning affected by the consequences of + + align:start position:0% +learning affected by the consequences of + + + align:start position:0% +learning affected by the consequences of +behavior and here's what we were going + + align:start position:0% +behavior and here's what we were going + + + align:start position:0% +behavior and here's what we were going +through before but one more thing I + + align:start position:0% +through before but one more thing I + + + align:start position:0% +through before but one more thing I +wanted to go through in just a little + + align:start position:0% +wanted to go through in just a little + + + align:start position:0% +wanted to go through in just a little +bit and that is another way to classify + + align:start position:0% +bit and that is another way to classify + + + align:start position:0% +bit and that is another way to classify +learning is to begin with the brain + + align:start position:0% +learning is to begin with the brain + + + align:start position:0% +learning is to begin with the brain +mechanisms and here I just focus on the + + align:start position:0% +mechanisms and here I just focus on the + + + align:start position:0% +mechanisms and here I just focus on the +forbrain I've not tried to do it for + + align:start position:0% +forbrain I've not tried to do it for + + + align:start position:0% +forbrain I've not tried to do it for +because we don't know enough really + + align:start position:0% +because we don't know enough really + + + align:start position:0% +because we don't know enough really +about the various kinds of synaptic + + align:start position:0% +about the various kinds of synaptic + + + align:start position:0% +about the various kinds of synaptic +mechanisms various kinds of of + + align:start position:0% +mechanisms various kinds of of + + + align:start position:0% +mechanisms various kinds of of +anatomical changes this field is still + + align:start position:0% +anatomical changes this field is still + + + align:start position:0% +anatomical changes this field is still +pretty young but we do know quite a bit + + align:start position:0% +pretty young but we do know quite a bit + + + align:start position:0% +pretty young but we do know quite a bit +about involvement of forbrain Pathways + + align:start position:0% +about involvement of forbrain Pathways + + + align:start position:0% +about involvement of forbrain Pathways +and the kinds of learning they're + + align:start position:0% +and the kinds of learning they're + + + align:start position:0% +and the kinds of learning they're +involved in so we can separate then + + align:start position:0% +involved in so we can separate then + + + align:start position:0% +involved in so we can separate then +learning of object location in the sense + + align:start position:0% +learning of object location in the sense + + + align:start position:0% +learning of object location in the sense +of an egocentric localization so if I if + + align:start position:0% +of an egocentric localization so if I if + + + align:start position:0% +of an egocentric localization so if I if +I glance at this group here you know I + + align:start position:0% +I glance at this group here you know I + + + align:start position:0% +I glance at this group here you know I +can retain In My Memory at least very + + align:start position:0% +can retain In My Memory at least very + + + align:start position:0% +can retain In My Memory at least very +briefly a working memory of of where + + align:start position:0% +briefly a working memory of of where + + + align:start position:0% +briefly a working memory of of where +various things are in this room in fact + + align:start position:0% +various things are in this room in fact + + + align:start position:0% +various things are in this room in fact +some people can actually see it if they + + align:start position:0% +some people can actually see it if they + + + align:start position:0% +some people can actually see it if they +shut their eyes I can I was talking to + + align:start position:0% +shut their eyes I can I was talking to + + + align:start position:0% +shut their eyes I can I was talking to +one of the students in this class about + + align:start position:0% +one of the students in this class about + + + align:start position:0% +one of the students in this class about +this probably 5 to 10% of you can do it + + align:start position:0% +this probably 5 to 10% of you can do it + + + align:start position:0% +this probably 5 to 10% of you can do it +but uh well you all have that ability + + align:start position:0% +but uh well you all have that ability + + + align:start position:0% +but uh well you all have that ability +you can remember briefly in your what we + + align:start position:0% +you can remember briefly in your what we + + + align:start position:0% +you can remember briefly in your what we +call working memory okay the egocentric + + align:start position:0% +call working memory okay the egocentric + + + align:start position:0% +call working memory okay the egocentric +position meaning where from position of + + align:start position:0% +position meaning where from position of + + + align:start position:0% +position meaning where from position of +my head and eyes something is you know I + + align:start position:0% +my head and eyes something is you know I + + + align:start position:0% +my head and eyes something is you know I +know the doors over there I know the + + align:start position:0% +know the doors over there I know the + + + align:start position:0% +know the doors over there I know the +clocks over there I know that's a wall + + align:start position:0% +clocks over there I know that's a wall + + + align:start position:0% +clocks over there I know that's a wall +and so on so forth and some of these + + align:start position:0% +and so on so forth and some of these + + + align:start position:0% +and so on so forth and some of these +even if I've seen it only briefly I will + + align:start position:0% +even if I've seen it only briefly I will + + + align:start position:0% +even if I've seen it only briefly I will +retain so that's a very simple kind of + + align:start position:0% +retain so that's a very simple kind of + + + align:start position:0% +retain so that's a very simple kind of +learning and we know about the pathways + + align:start position:0% +learning and we know about the pathways + + + align:start position:0% +learning and we know about the pathways +involved in + + align:start position:0% +involved in + + + align:start position:0% +involved in +that + + align:start position:0% +that + + + align:start position:0% +that +uh as for object identity we we know + + align:start position:0% +uh as for object identity we we know + + + align:start position:0% +uh as for object identity we we know +it's another kind of learning but we + + align:start position:0% +it's another kind of learning but we + + + align:start position:0% +it's another kind of learning but we +also now have another kind of + + align:start position:0% +also now have another kind of + + + align:start position:0% +also now have another kind of +localization namely allocentric + + align:start position:0% +localization namely allocentric + + + align:start position:0% +localization namely allocentric +localization where am I in this + + align:start position:0% +localization where am I in this + + + align:start position:0% +localization where am I in this +environment where am I in this building + + align:start position:0% +environment where am I in this building + + + align:start position:0% +environment where am I in this building +where am I in Cambridge and so on so + + align:start position:0% +where am I in Cambridge and so on so + + + align:start position:0% +where am I in Cambridge and so on so +forth and we are learning that all the + + align:start position:0% +forth and we are learning that all the + + + align:start position:0% +forth and we are learning that all the +time and then I've listed other things + + align:start position:0% +time and then I've listed other things + + + align:start position:0% +time and then I've listed other things +like learning of sensor motor + + align:start position:0% +like learning of sensor motor + + + align:start position:0% +like learning of sensor motor +coordination movement patterns that's + + align:start position:0% +coordination movement patterns that's + + + align:start position:0% +coordination movement patterns that's +easier to relate to the things that + + align:start position:0% +easier to relate to the things that + + + align:start position:0% +easier to relate to the things that +Lawrence is talking about what about the + + align:start position:0% +Lawrence is talking about what about the + + + align:start position:0% +Lawrence is talking about what about the +formation of plants that's a kind of + + align:start position:0% +formation of plants that's a kind of + + + align:start position:0% +formation of plants that's a kind of +learning because we're changing them all + + align:start position:0% +learning because we're changing them all + + + align:start position:0% +learning because we're changing them all +the time in our brain okay involving + + align:start position:0% +the time in our brain okay involving + + + align:start position:0% +the time in our brain okay involving +prefrontal areas of the + + align:start position:0% +prefrontal areas of the + + + align:start position:0% +prefrontal areas of the +cortex and then I go through this a + + align:start position:0% +cortex and then I go through this a + + + align:start position:0% +cortex and then I go through this a +little more uh expanding the object + + align:start position:0% +little more uh expanding the object + + + align:start position:0% +little more uh expanding the object +location to include objects associated + + align:start position:0% +location to include objects associated + + + align:start position:0% +location to include objects associated +with places so the places are kind of we + + align:start position:0% +with places so the places are kind of we + + + align:start position:0% +with places so the places are kind of we +remember those by a kind of allocentric + + align:start position:0% +remember those by a kind of allocentric + + + align:start position:0% +remember those by a kind of allocentric +orientation to place that's with respect + + align:start position:0% +orientation to place that's with respect + + + align:start position:0% +orientation to place that's with respect +to the environment not with respect to + + align:start position:0% +to the environment not with respect to + + + align:start position:0% +to the environment not with respect to +where we are at the + + align:start position:0% +where we are at the + + + align:start position:0% +where we are at the +moment but that's a kind of Association + + align:start position:0% +moment but that's a kind of Association + + + align:start position:0% +moment but that's a kind of Association +learning we we associate objects with + + align:start position:0% +learning we we associate objects with + + + align:start position:0% +learning we we associate objects with +specific places and we're only in the + + align:start position:0% +specific places and we're only in the + + + align:start position:0% +specific places and we're only in the +last few years are learning how that is + + align:start position:0% +last few years are learning how that is + + + align:start position:0% +last few years are learning how that is +done in the brain + + align:start position:0% + + + + align:start position:0% + +uh and of course we know a lot about + + align:start position:0% +uh and of course we know a lot about + + + align:start position:0% +uh and of course we know a lot about +learning of object identity I've just + + align:start position:0% +learning of object identity I've just + + + align:start position:0% +learning of object identity I've just +mentioned some of the characteristics + + align:start position:0% +mentioned some of the characteristics + + + align:start position:0% +mentioned some of the characteristics +from a behavioral point of view and then + + align:start position:0% +from a behavioral point of view and then + + + align:start position:0% +from a behavioral point of view and then +ways to classify them according to their + + align:start position:0% +ways to classify them according to their + + + align:start position:0% +ways to classify them according to their +potential uses which neuroscientists + + align:start position:0% +potential uses which neuroscientists + + + align:start position:0% +potential uses which neuroscientists +don't pay a lot of attention + + align:start position:0% +don't pay a lot of attention + + + align:start position:0% +don't pay a lot of attention +to + + align:start position:0% +to + + + align:start position:0% +to +um here's the thing about learning + + align:start position:0% +um here's the thing about learning + + + align:start position:0% +um here's the thing about learning +knowledge of + + align:start position:0% +knowledge of + + + align:start position:0% +knowledge of +place uh besides a very rapid assessment + + align:start position:0% +place uh besides a very rapid assessment + + + align:start position:0% +place uh besides a very rapid assessment +of where we are what we call seene + + align:start position:0% +of where we are what we call seene + + + align:start position:0% +of where we are what we call seene +perception um we + + align:start position:0% +perception um we + + + align:start position:0% +perception um we +learn where we are with respect to + + align:start position:0% +learn where we are with respect to + + + align:start position:0% +learn where we are with respect to +visual landmarks and for primates that's + + align:start position:0% +visual landmarks and for primates that's + + + align:start position:0% +visual landmarks and for primates that's +probably major but for many animals it's + + align:start position:0% +probably major but for many animals it's + + + align:start position:0% +probably major but for many animals it's +still Factory the smell of a place + + align:start position:0% +still Factory the smell of a place + + + align:start position:0% +still Factory the smell of a place +that's more + + align:start position:0% +that's more + + + align:start position:0% +that's more +important uh but we also many animals we + + align:start position:0% +important uh but we also many animals we + + + align:start position:0% +important uh but we also many animals we +know learn where they are with respect + + align:start position:0% +know learn where they are with respect + + + align:start position:0% +know learn where they are with respect +to more Global a more global map + + align:start position:0% +to more Global a more global map + + + align:start position:0% +to more Global a more global map +magnetic cues infr infrasound + + align:start position:0% +magnetic cues infr infrasound + + + align:start position:0% +magnetic cues infr infrasound +patterns um we even learn place in a + + align:start position:0% +patterns um we even learn place in a + + + align:start position:0% +patterns um we even learn place in a +Time cycle but we know the least about + + align:start position:0% +Time cycle but we know the least about + + + align:start position:0% +Time cycle but we know the least about +that and I also want to point out that + + align:start position:0% +that and I also want to point out that + + + align:start position:0% +that and I also want to point out that +we have we we have this knowledge we've + + align:start position:0% +we have we we have this knowledge we've + + + align:start position:0% +we have we we have this knowledge we've +acquired of anticipated positions + + align:start position:0% +acquired of anticipated positions + + + align:start position:0% +acquired of anticipated positions +because every time we move our head + + align:start position:0% +because every time we move our head + + + align:start position:0% +because every time we move our head +around and our eyes we're activating + + align:start position:0% +around and our eyes we're activating + + + align:start position:0% +around and our eyes we're activating +we're say we're activating long-term + + align:start position:0% +we're say we're activating long-term + + + align:start position:0% +we're say we're activating long-term +memories but in the spatial system + + align:start position:0% +memories but in the spatial system + + + align:start position:0% +memories but in the spatial system +putting it in our anatomical terms we're + + align:start position:0% +putting it in our anatomical terms we're + + + align:start position:0% +putting it in our anatomical terms we're +activating a system uh connected with + + align:start position:0% +activating a system uh connected with + + + align:start position:0% +activating a system uh connected with +our head head Direction that's + + align:start position:0% +our head head Direction that's + + + align:start position:0% +our head head Direction that's +activating + + align:start position:0% +activating + + + align:start position:0% +activating +memories we're aware of what's in that + + align:start position:0% +memories we're aware of what's in that + + + align:start position:0% +memories we're aware of what's in that +direction what's in this direction and + + align:start position:0% +direction what's in this direction and + + + align:start position:0% +direction what's in this direction and +so forth that's how we know which way to + + align:start position:0% +so forth that's how we know which way to + + + align:start position:0% +so forth that's how we know which way to +go so it's connected with our + + align:start position:0% +go so it's connected with our + + + align:start position:0% +go so it's connected with our +motivational system as well as the + + align:start position:0% +motivational system as well as the + + + align:start position:0% +motivational system as well as the +highest systems of the brain and the + + align:start position:0% +highest systems of the brain and the + + + align:start position:0% +highest systems of the brain and the +hippoc cample formation is involved in + + align:start position:0% +hippoc cample formation is involved in + + + align:start position:0% +hippoc cample formation is involved in +learning those + + align:start position:0% +learning those + + + align:start position:0% +learning those +things all + + align:start position:0% +things all + + + align:start position:0% +things all +right so we need to fill in a lot of + + align:start position:0% +right so we need to fill in a lot of + + + align:start position:0% +right so we need to fill in a lot of +gaps in this the in lawence types and + + align:start position:0% +gaps in this the in lawence types and + + + align:start position:0% +gaps in this the in lawence types and +I've count about 19 separate types in + + align:start position:0% +I've count about 19 separate types in + + + align:start position:0% +I've count about 19 separate types in +Lawrence + + align:start position:0% +Lawrence + + + align:start position:0% +Lawrence +descriptions and uh if you include those + + align:start position:0% +descriptions and uh if you include those + + + align:start position:0% +descriptions and uh if you include those +iel iisf types he + + align:start position:0% +iel iisf types he + + + align:start position:0% +iel iisf types he +describes uh that hasn't been fully + + align:start position:0% +describes uh that hasn't been fully + + + align:start position:0% +describes uh that hasn't been fully +integrated with the other means of + + align:start position:0% +integrated with the other means of + + + align:start position:0% +integrated with the other means of +classifying + + align:start position:0% +classifying + + + align:start position:0% +classifying +learning okay I'm going to stop there + + align:start position:0% +learning okay I'm going to stop there + + + align:start position:0% +learning okay I'm going to stop there +and turn on the + + align:start position:0% + + + + align:start position:0% + +video this is some of you may have seen + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +some content has been removed due to + + align:start position:0% +some content has been removed due to + + + align:start position:0% +some content has been removed due to +copyright restrictions see the readings + + align:start position:0% +copyright restrictions see the readings + + + align:start position:0% +copyright restrictions see the readings +and viewings page for more information \ No newline at end of file diff --git a/pi1IagGYJ3E.txt b/pi1IagGYJ3E.txt new file mode 100644 index 0000000000000000000000000000000000000000..e93116b235a45e00c93c62bde68b15884deefe16 --- /dev/null +++ b/pi1IagGYJ3E.txt @@ -0,0 +1,2084 @@ +PROFESSOR: Another strange +observation about mirrors that + +I've never really understood-- + +the mirror plane is reflecting +me left to right, so it looks + +as though a mirror has +a grain to it. + +It knows what line to reflect +me back and forth. + +But if I kept the mirror in +fixed orientation and I lay + +down, the thing should +reflect me side to + +side, but it doesn't. + +It still reflects me +from top to bottom. + +So how can that be? + +Why does a mirror plane, if I +hold it in one orientation, + +appear to have a direction +across which I'm reflected but + +it doesn't follow +me if I move? + +Know what I mean? + +You have any explanation +of that? + +Hmm? + +AUDIENCE: Rotate +your eyes, too. + +PROFESSOR: Rotate my eyes. + +I can roll them around. + +I can't rotate in any +other fashion. + +That's strange. + +I mean, you look at yourself +every morning-- + +several times, perhaps, +and you're reflected + +always left to right. + +And if you turn the +mirror, it doesn't + +reflect you top to bottom. + +Or conversely, you can leave the +mirror alone and you can-- + +why does a mirror plane just +reflect you left to right? + +Ah. + +I'll let you stew about +that one for a while. + +And I can tell you that I know +of three papers in scientific + +journals that tried +to explain this. + +I can give you literature +citations, but you think about + +it until our next meeting. + +Why does it know which +way I'm oriented? + +Ah, I can't think about it. + +Alright, back to more +straightforward questions. + +We are now about to embark on +a grand process of synthesis + +which will take us the better +part of half a semester. + +And we've identified our +four basic operations-- + +four basic one step +operations-- + +namely translation, reflection, +rotation, and for + +the time being I'm going to look +just at two-dimensional + +symmetries, so I'll leave +inversion out of the picture. + +It's only defined in three +dimensions, and the logic + +which I will follow will be to +first build up two-dimensional + +symmetries and then we'll turn +them into three-dimensional + +symmetries by picking another +translation that's not + +coplanar with the first two. + +So we're going to look for +the time being at just + +two-dimensional symmetries. + +The nice thing about doing this +is that the number of + +two-dimensional symmetries is +relatively small, so we can + +derive them rigorously +and exhaustively. + +To do so in three dimensions is +a much more time consuming + +and elaborate exercise. + +It's no different in principle, + +there's just more work. + +So if we do two-dimensional +symmetries first, + +it's an easy case. + +We can do it rigorously and +completely, and then what + +we'll do is just look at a few +examples in three dimensions + +and look at how the results are +designated and tabulated. + +So the first combination I will +choose to make is one + +that I set up last time and +should not have started when + +there was no time +to finish it. + +So let me take an initially +pristine space and say that to + +this I'm going to the operation +of translation. + +That immediately implies a +string of translations and a + +string of lattice points, but +I'm just going to focus my + +attention on the first one. + +Then what I said I'll do is add +to the space a rotation + +operation A alpha. + +I'm going to for convenience +put it right at the lattice + +point, but as there is no +unique origin to the + +translation, I can start +and stop the + +translation anywhere I like. + +So here's my translation. + +The rotation operation is going +to take that translation + +and repeat it at angular +intervals alpha so that I get + +a radiating porcupine-like +sheaf of translations all + +coming out of a common point. + +Alpha, we observed, has to be +a submultiple of 2 pi, so I + +will have a cluster of +translations separated by the + +equal interval alpha-- + +angular interval alpha-- + +and I'm going to choose to +focus my attention on + +just the first one. + +So this, since it's repeated +by rotation, has the same + +length T. + +And then I'm going to look +at the other end of the + +translation and say that +similarly I must have a set of + +equally spaced angular-wise +translations all separated by + +alpha, and I'm going to choose +to focus my attention + +just on this one. + +So this angle is alpha, and +this angle here is alpha. + +And now there's big trouble +in River City. + +This is a translation, here's +a lattice point, here's a + +lattice point. + +This is a translation-- + +a lattice point sits up here. + +This is a translation-- + +a lattice points sits up here. + +Now I've got two lattice points +eyeball to eyeball, and + +they jolly well better be +separated by either the + +interval T or some multiple +P times T, + +where P is some integer. + +It would be quite all right if +there were two translation + +separation or five translation +separation, but it must be + +some multiple of translation or +I have violated my initial + +premise that everything in this +space is periodic at a + +translational interval T. + +So let me take this geometrical +constraint and + +very quickly convert it into +analytical form so that we can + +proceed to systematically +find out what the + +possibilities are. + +Let me drop a perpendicular +down to the original + +translation. + +So this distance in here is PT, +this distance will be T + +times the cosine of alpha, and +this distance in here will be + +T times the cosine of alpha. + +So in analytic form, then, I +can say that my original + +translation T is equal +to T cosine of alpha + +plus T cosine of alpha. + +That's 2T cosine of +alpha plus PT. + +And the first thing we can see +is that the magnitude of T + +drops out because this +construction and the + +constraint it embodies in no way +depends on the magnitude + +of the translation. + +So this says, then, that 1 is +equal to 2 cosine of alpha + +plus the integer P. And if I +solve for the value of cosine + +of alpha, cosine of alpha will +be 1 minus an integer P + +divided by 2. + +So there is the constraint that +must be followed if my + +construction is to be +self-consistent. + +So we've got this now in a +plug and chug situation. + +So what I'm going to put down is +the value of P, taking all + +possible integers for +which a value of + +cosine of alpha exists. + +I'm then going to evaluate +cosine of alpha, which is 1 + +minus P over 2, and then I'm +going to identify the n-fold + +axis that corresponds to that +particular value of alpha. + +Let's put in P equals 3, +and this is as far + +as we got last time. + +Well, if we put 4, then cosine +of alpha is minus 3/2-- + +it's not defined. + +If we drop P down to 3, then +cosine of alpha is minus 1, 1 + +minus 3 over 2. + +And the angle whose cosine +is minus 1 is a-- + +let me put down the +value of alpha and + +then the n-fold axis. + +The angle whose cosine is minus +1 is 180 degrees, and + +that would describe quite nicely +the rotational throw of + +a twofold axis. + +If I let P drop down to the +value 2, then I have minus 1/2 + +of the cosine of alpha. + +The angle whose cosine is minus +1/2 is 120 degrees. + +And guess what? + +That's the angular throw +of a threefold axis. + +Let P drop down to 1, and then +cosine of alpha is 0. + +The angle whose cosine is 0 is +90 degrees, and that would be + +a fourfold axis. + +Looks like we're done, except +P could be equal to 0. + +In that case, cosine of +alpha is plus 1/2. + +The angle whose cosine is plus +1/2 is equal to 60 degrees, + +and that's a sixfold access. + +What about negative integers? + +Minus one, will that work? + +This says that cosine of alpha +is 1, and the angle whose + +cosine is one is 0 degrees +or 360 degrees. + +And that would be no rotational +symmetry all. + +It's rather amusing that the +trivial case of no symmetry at + +all also falls out of +this construction. + +So this is a momentous result. + +We've shown that if you're going +to have a pattern that + +has a repetition by translation +in it, the number + +of rotational symmetries that +can be added are either no + +symmetry at all, a twofold +rotational symmetry, + +threefold, fourfold, +or sixfold. + +In other words, the axis-- + +no symmetry at all, twofold, +threefold, fourfold, or + +sixfold, nothing else. + +This tells you a lot about the +shapes that you can see + +macroscopically on crystals. + +You could have a crystal that +had the shape of the trigonal + +prism, and that would +be perfectly fine. + +You could have a crystal that +had the shape of an orthogonal + +brick that would have twofold +axes coming out of the faces. + +You could have a crystal in +the shape of a hexagonal + +present, or you could have a +crystal in the shape of the + +square prism. + +But something thing like a +crystal with a pentagonal + +cross section that would +be a fivefold access-- + +that is strictly forbidden, +because the external shape of + +the crystal has to reflect the +internal symmetry among the + +arrangement of atoms. + +There are lots of things +in nature that have + +crystallographic symmetry. + +There is a little cactus that +looks like this with some + +little spines coming out like +this on the top, and its + +proper name is astrophytum +myriostigma, also known as the + +ornamented bishops cap. + +Beautiful example of fivefold +symmetry, but the cells inside + +of that cactus can not have the +same size and shape and be + +repeated by translation. + +There are flowers that have +very common examples of + +fivefold and even sevenfold +symmetry. + +There's one little purple flower +that looks like this + +that comes out in the spring, +and that's called periwinkle. + +Fivefold symmetry-- fine for a +plant, but if you got down + +inside the stem of this flower, +the cells cannot be + +repeated by translation. + +There are astronomically +high symmetries. + +These big giant cacti in the +Southwest, the saguaro, they + +have rotational symmetries +that run from 18-fold, + +19-fold, 23-fold, so that if +you picked up one of these + +guys very carefully, because +they're covered with spines, + +and if you could lift it-- +which would be very hard + +because they weigh a +couple of tons-- + +take that guy and rotate them +through 1/27 of a circle, and + +if he had 27-fold symmetry, you +could plop them down and + +you couldn't tell that +it had been moved. + +There is no crystallographer +who can resist cacti. + +All sorts of symmetry, even +symmetries that violate + +crystal graphic symmetries-- + +wonderful textures and colors. + +And they have another really +remarkable property, which + +commends them as house plants. + +If they die, this sheath of +spines stays intact until + +someday when you're watering it, +you brush against it and + +you poke a hole right through +the spines and + +there's nothing inside. + +So a house plant that dies and +you can't tell for two years + +or so is a very good plant +to have as a companion. + +So cacti have all sorts +of strange symmetries. + +Fine, but you can say something +about the internal + +structure of that flower +or that cactus. + +But this little almost trivial +proof has told us something + +else about crystals, because +the presence of translation + +imposes a constraint on the +rotational symmetry that can + +be present, and the rotational +symmetry tells us something + +about the nature of the +two-dimensional lattice which + +can accommodate that symmetry. + +So let's go through this list +once more, and let's pay + +attention to the value of P. + +For a twofold rotational +symmetry, what we would do + +would be to take this original +translation, we put the + +twofold axis here, and that +takes the translation and + +rotates it around. + +So here's a lattice point here, +one here, one here, and + +the twofold axis here, takes the +translation and we rotate + +in a counterclockwise sense. + +Here's another lattice +point here. + +P was equal to three +translations, and I'll be + +darned if that isn't exactly +what we have. + +Three translations from +this lattice point A-- + +let me put some labels +up here. + +This was lattice point A, this +was lattice point B, and this + +was our translation PT. + +Three translations, just +as advertised. + +What constraint does this +put on a lattice? + +None whatsoever, because all +this says is that if you have + +a translation that translation +must be repeated into an + +extended one-dimensional row. + +So you can put this an any +2D lattice whatsoever. + +In other words, the magnitudes +of the two translations-- + +let's call them T1 and T2 are +under no constraint to be + +related one to another-- + +and this angle between +them, alpha, can be + +anything that it likes. + +You could have a twofold axis, +but that requires simply a + +lattice row parallel to T1 and +a lattice row parallel to T2. + +The next integer we +hit was minus 1/2. + +That was cosine of minus 1/2, +this was P equals 3, and that + +corresponded to something +that could + +accept a threefold symmetry. + +So let me put a guide to the +I in here and make an + +equilateral triangle. + +If we translate and rotate +up by 120 degrees using a + +threefold axis and then rotate +minus 120 degrees about the + +other lattice point, that +puts another translation + +up here, and now-- + +I'm sorry, this was P equals 2 +And as required, this is PT, + +and that's equal to +two translations. + +This has put a constraint on the +sort of lattice which can + +exist in this space because we +have two translations, T1 and + +T2, which are equal in +magnitude, identical in + +magnitude, because they're +related by symmetry. + +And consequently, we have +defined a space lattice, a + +two-dimensional space lattice. + +We'll call this T1 +and call this T2. + +This lattice has the constraint +that magnitude of + +T1 must be identical to the +magnitude of T2, and the angle + +between T1 and T2 is again +identically 120 degrees. + +Not 119.9, but exactly 120 +degrees because there is a + +threefold axis in here that +demands that that be so. + +So this is a very specialized +kind of lattice, restricted to + +have two translations identical +in magnitude. + +And if there's a threefold axis +there, you should be able + +to find these two. + +And if there's a threefold axis +there, then the angle + +between these two specialized +translations is 120 degrees. + +Our next magic integer was 1, +and that corresponded to a + +fourfold axis. + +And if we do what we claimed we +did in that construction, + +we'd put a fold axis here. + +That takes T1 and rotates it +exactly 90 degrees to a + +translation T2. + +Once again, two noncollinear +translations, so we have + +defined a two-dimensional net. + +If we complete the cell, this +is one translation. + +PT is equal to one translation +in here, and this angle is 90 + +degrees because it's produced +by a fourfold axis. + +So we have a very +special lattice. + +Again, the magnitudes of two +translations are identical-- + +not approximately the same, +they're identical-- + +and the angle between them is +identically 90 degrees. + +Only a couple to go. + +P could be equal to 0, and that +was the case for a 60 + +degree rotation, +a sixfold axis. + +So again, let's draw what +came out of this + +particular special case. + +Here's T1, here is T2. + +This angle is 60 degrees exactly +because there's a + +six-fold rotation axis here, a +sixfold rotation axis here, + +and the rotation of 60 in the +opposite sense gives us + +another translation here. + +These two lattice points +coincide and there is PT equal + +to 0T, and these two +points coincide. + +Now if I complete a standard +unit cell with T1 T2 as I've + +done in other cases-- + +this was T1, this was T2, this +was a translation which I'm + +not going to use. + +So this is the shape of the +lattice and these now are + +lattice points with a sixfold +axis on them. + +The dimensional specialization +is exactly the same as I found + +for a threefold axis, +T1 identical to T2. + +If I pick this cell, T1 to T2 +can be described as an angle + +of 120 degrees. + +Exactly the same lattice that we +found for a threefold axis. + +So with this simple minded +little construction we've + +found two profound things-- + +that there are five kinds of +rotation axes, including the + +onefold no rotational +symmetry at all. + +And it turns out that there are +one, a general lattice, a + +hexagonal lattice, and +the square lattice. + +There are three kinds of +two-dimensional lattices that + +are required by these +symmetry elements. + +So these guys require that +there be three lattice of + +different specializations that +are able to accommodate them. + +So let me call this a +parallelogram net, and that + +has T1 not equal to +T2, the angle + +between T1 and T2 general. + +And this is a lattice that can +accommodate either no symmetry + +at all or a twofold +rotation access. + +Then there was a net that I'll +call the hexagonal net, and + +this had T1 identical to T2 in +magnitude, and it had the + +angle between them, the angle +between T1 and T2 as + +identically 120 degrees. + +And this could accommodate +either a threefold or a + +sixfold axis. + +And then finally, the general +net, which I call a + +parallelogram net, and that +has magnitudes of the two + +translations not equal +to one another. + +They can have any values they +like, and the angle between T1 + +and T2 is completely general. + +And that's exactly what I had +up here for the-- oh, we did + +that once already. + +The one that I'm missing, the +third one, is the square net. + +Square net has T1 +identical to T2. + +In magnitude, the angle between +them is exactly 90 + +degrees, and that is required +by a fourfold axis. + +Let me pause here to see if +there are any questions. + +Yes, sir. + +AUDIENCE: When you write on the +last one with the sixfold, + +it's only 120. + +You could have also written +60, correct? + +PROFESSOR: Yes, I could have. + +And this lattice is actually the +same as what I found for a + +threefold axis. + +I could pick either this or this +as the cell, but the two + +translations in those +two cells are equal. + +And again at various stages +along the way, we'll need a + +convention. + +And if I have a net that looks +like this, a parallelogram, + +whether a specialized +parallelogram or not, I have a + +choice of two angles +that I could use. + +We call that alpha. + +This is going to be 180 +degrees minus alpha. + +Which do I pick? + +You need a rule, and the rule is +that for labeling the cell, + +pick alpha so that it's greater + +or equal to 90 degrees. + +That's pure convention, but you +want to have a rule just + +like a language so people use +the same words to describe the + +same thing. + +Here we want to use the same +geometry to describe one and + +the same thing. + +The other convention is that +there are no unique + +translations that +define a net. + +We could take linear +combinations of these vectors + +and define the same lattice, +so we need another rule for + +selecting the standard +translations-- + +again, so that two people can +do an x-ray diffraction + +experiment and report the +results in terms of the same + +lattice, and this is a fairly +reasonable thing. + +This is pick the two shortest +translations, and that clearly + +makes sense. + +There's absolutely nothing at +all to commend a cell that has + +this as T2 and this as +T1 so you get a long, + +skinny oblique things. + +Your natural inclination would +pick the two shortest + +translations in the net. + +OK, so these are conventions. + +This has nothing to do with the +nature of the symmetry or + +what makes it unique, but just +so that people have one + +defined way of labeling +things. + +AUDIENCE: Right. + +[INAUDIBLE] my question +was actually that-- + +PROFESSOR: It was a good answer, +even if was not to the + +question that you asked. + +AUDIENCE: I said the sixfold and +the threefold are exactly + +the same, but then I realized +they are because there is no + +crystal that can have threefold + +symmetry without sixfold. + +PROFESSOR: You were +doing fine. + +You should have quit just before +that last statement. + +How can you have a hexagonal +lattice that sometimes has + +sixfold symmetry and sometimes +has threefold symmetry? + +Well, let me give you an example +for that, and it makes + +a very useful point. + +Let me draw two hexagonal nets, +and in this one I'll put + +a threefold axis. + +So I'll have one motif here, +I'll go 120 degrees away. + +Here is a motif here, and I'll +go 120 degrees away, and here + +is a third motif. + +So these three guys form +a triangle about + +this lattice point. + +And we would have about the +other lattice points at the + +corners of the cell exactly the +same triangle of motifs, + +and the same thing over here. + +So there is a pattern. + +It has a hexagonal lattice, +and it has a triangle of + +objects related by +a threefold axis. + +And now let me take exactly the +same lattice, and now I'll + +put in instead a sixfold axis. + +And that means I'm going to have +a hexagon of objects, and + +it'll do something like this. + +And I don't want to push my +luck and try to draw that + +twice, but there would be a +hexagon here and a hexagon of + +motifs here, another one at +this lattice point, and + +another one at this lattice +point here. + +Same lattice, same shape, +same dimensions-- + +although that's not critical-- + +but one of them has only +a threefold axis. + +One of them has only a +sixfold axis in it. + +Why? + +Because I decided to put a +threefold axis in this + +pattern, and I decided to put +a sixfold axis in this + +pattern, but they both end up +being contented and happy with + +a lattice with the same degree +of specialization. + +Now we will come as we +progressed a little bit + +further that we have to +go in two dimensions + +to the reverse situation. + +We have a particular symmetry +and it's happy with two + +different sorts of lattices +with different shapes and + +different specializations, +and that's + +going to come up directly. + +Any other questions? + +Yeah. + +AUDIENCE: In this example, +the sixfold [INAUDIBLE] + +axis [INAUDIBLE]. + +It's just that [INAUDIBLE]. + +PROFESSOR: Yes. + +You're saying that here hanging +at this lattice point + +is something that has +sixfold symmetry. + +Here is something has only +threefold symmetry. + +The nature of the lattice and +the symmetry that is in that + +lattice are two inseparable +aspects of the pattern. + +But often, as we've seen here, +there's more than one + +possibility for a +given lattice. + +And as we'll see very shortly, +for some other symmetries, for + +one given symmetry, there are +two kinds of lattices. + +But nevertheless, the thing to +keep fixed in your mind is + +that we call this a +hexagonal lattice. + +Why? + +Because this translation is +equal to this one, and they + +are exactly 120 degrees apart. + +That lattice can have that +specialness only if there's + +either a threefold or a +sixfold axis in it. + +So the specialization of a +lattice is inseparable from + +the symmetry that is in the +lattice that demands that + +specialization of the lattice. + +Conversely, a lattice can have +the specialization only if you + +place in a symmetry which +demands precisely that + +specialization. + +So if you measure a lattice, +and this turns out to be + +119.99 degrees and these turn +out to be 3.21 angstroms and + +3.21 angstroms, that is not a +hexagonal lattice, because + +there's no symmetry in there +that demands that this angle + +be 120 degrees. + +And that may seem to be an +academic fine point, but we'll + +see that in due course the +properties of a crystal depend + +on the symmetry of +that crystal. + +If the crystal has symmetry, the +property also has to have + +that symmetry. + +And it is the atoms inside the +cell which determine the + +symmetry of the property, and +the properties is one aspect + +of the symmetry that goes along +with lattice dimensions + +and lattice angles. + +Is that clear? + +So let me say it again, +because this is + +an important point. + +The specialness of a lattice +is inseparable from the + +symmetry that is existing in +that lattice that demands that + +specialness. + +So if you have a crystal with +three orthogonal translations + +that is equal in length as you +might care to measure, that + +crystal is not cubic unless +there's symmetry in that + +lattice that demands that the +edges of the cell conform to + +the geometry of a cube. + +Any other questions? + +Let's then in the time that's +remaining look at the other + +symmetry element that could be +present in a two-dimensional + +crystal, and that's +the mirror plane. + +So here's a mirror plane. + +That's the one remaining +symmetry element in two + +dimensions, and let's ask how we +might combine in this space + +along with the mirror +plane a translation. + +If I just pop in a translation, +and call this T1, + +and for convenience, I'll take +the lattice point on the + +mirror plane. + +Here's another lattice +point that sits here. + +The mirror plane acts +on everything. + +It's going to take this lattice +point and flip it over + +to here, and it's going to take +the translation that goes + +from the origin lattice point to +this lattice point and give + +me a T1 prime that sits here. + +And now I have two non collinear +translations, so + +these have defined for me a +cell that looks like this. + +This is T1, this is T2, and +this is some angle alpha + +between them. + +That's a special lattice. + +This is a lattice which has, +just as in the hexagonal or + +square net, two translations +that are + +identical in magnitude. + +Why? + +Because they're repeated by a +mirror plane, and the angle + +between them-- the angle +between T1 and T2-- + +is completely general. + +It can be anything it likes. + +It can close up to a very narrow +angle or it can open up + +to an almost flat angle. + +That's a new kind of lattice. + +None of the preceding lattices +could make that claim. + +Now let me point out that this +is for the first time a case + +where it would be much to our +advantage to not choose a cell + +that contains one +lattice point. + +Let me put some dotted +lines in here. + +And let me submit-- + +these will also be +lattice points-- + +that I could pick a larger cell +that would have this as + +T1, it would have this as T2, +and the angle between them now + +would be identically 90 +degrees because of the + +geometry that gives +us a rhombus here. + +This would have two translations +that are not + +equal in magnitude, and it would +have an angle between + +these two translations that is +identically 90 degrees, but it + +is no longer a cell that +contains one lattice point. + +It now catches a second +lattice point + +that's in the middle. + +So this is a double cell, and +it has a rectangular shape. + +It's a centered rectangular +lattice. + +Being a double cell that's +redundant has twice the area + +that is unique in the pattern, +and anything that's hanging up + +here is going to be hanging down +here, so it has a twofold + +redundancy. + +But the thing that you get in +return for paying the price of + +that redundancy is a cell that +has a right angle in it. + +And as we'll see, we're going +to use the edges of the unit + +cell as the basis of a +coordinate system for + +describing what goes on at +positions xy within the cell. + +And the advantages of an +orthogonal coordinate system, + +whenever you can take advantage +of it, far outweighs + +the price of pain-- + +twice the area to describe +the same pattern. + +So this is what is generally +taken as the standard cell. + +It's a double cell. + +But I think you're used to +that sort of compromise, + +because you've all heard of face +centered cubic lattices. + +The primitive cell in a face +centered cubic lattice is a + +rhombohedron. + +But, oh, that Cartesian +coordinate system is so great + +to use rather than something +that has an + +oblique coordinate system. + +So is this is a definition +of convenience. + +Notice the curious duality-- + +either special relation between +the translations angle + +general or special relation +between the translations, an + +angle special. + +General translation, special +angle, relation between the + +translation, general angle-- + +so, it's a curious +sort of duality. + +You can have one but not the +other or vice versa. + +So this is a fourth +sort of lattice. + +Number one, number two, number +three, and now we have number + +four, which is a centered +rectangular lattice. + +And this particular lattice +has T1 not equal to T2 in + +magnitude, but it has the +angle between T1 and T2 + +exactly 90 degrees, and +it's a double cell. + +It's centered. + +Are we done? + +The reason I asked that silly +rhetorical question is that + +obviously I suspect that we're +not done, and what + +else might we do? + +We got our centered rectangular +net by starting + +with a translation-- + +starting with an mirror +plane, really-- + +and then we added a general +translation, and that + +reflected it across and gave us +a diamond shaped net which + +we could define as a rectangular +double shell. + +Does that always happen? + +Do I always get that oblique +diamond shaped cell? + +No. + +Suppose I put in my first +translation deliberately in a + +fashion such that it was at +exactly right angles to the + +mirror plane. + +That mirror plane will then +reflect the translation and + +change its direction, and +now I have generated a + +one-dimensional lattice +row with + +translational periodicity T1. + +And I've got a translation +that's exactly perpendicular + +to the mirror plane. + +How do I now make a space +lattice, a two-dimensional + +space lattice? + +And the answer is +very carefully. + +Suppose I throw in a second +translation T2 and the mirror + +plane reflects it +across to here. + +This interval between lattice +points up here is totally in + +commensurate with the +first translation, + +and that won't work. + +It's violated my initial choice +of the translational + +periodicity unless I do one of +two things, and let's try them + +both and dispose of +this quickly-- + +this is straight away. + +Here's my one-dimensional +lattice row. + +I do not violate this +periodicity + +T1 if I do two things. + +I could pick T2 so that it fell +exactly along the mirror + +line, and that's going to +generate for me a new type of + +lattice in which this is 90 +degrees and these two + +translations are unequal +in length. + +So this is a lattice that +has a rectangular shape. + +It's a primitive rectangular +cell, and it has T1 not equal + +to T2 in magnitude, and +it has T1 and T2 + +exactly 90 degrees apart. + +The second choice that would +not result in any + +contradiction would be to have +this as T1, and then pick T2 + +very carefully so that it +spanned the mirror line with + +one half of T1 exactly +up here and one half + +of T1 exactly here. + +And this would be compatible +with the separation T1 down at + +the start of this translation. + +I think you can see that what +this is going to give me is + +the centered rectangular net +right back again, so this is + +the centered rectangular net-- + +nothing new. + +But we did pick up one +additional two-dimensional + +lattice of distinct character. + +Number 5 is a primitive +rectangular network, and it + +has the characteristics T1 is +not equal to T2 in magnitude. + +Just as in the centered +rectangular net, T1 is at + +exactly 90 degrees to T2, but +this is a primitive cell. + +And that's it. + +We really set up the ground +rules for the geometry of a + +periodic two-dimensional +space. + +There are five kinds +of rotation axes-- + +one, two, three, +four, and six. + +Each one requires one or +more of the specialized + +two-dimensional lattices. + +We have a case where +interestingly two different + +symmetries are compatible with +a lattice of the same + +specialization. + +In the case of the [? hexagon ?] +on that, either + +three or sixfold symmetry +could require that. + +In the case of the mirror plane +we have one symmetry + +element, M, that can +fit into two + +different kinds of lattices. + +So in one case, the same lattice +can take two different + +symmetries. + +In this case, two different +lattices can accommodate the + +same symmetry. + +So that's the story for two +dimensions, and we have just + +one final thing to do. + +That is to add to the lattices +that we have found, and there + +are five of them, and add +to the lattice point the + +symmetries that we have +found require them. + +And there are a limited number +of these-- one, two, three, + +four, or sixfold rotational +symmetry in a mirror plane. + +And when we have finished these +additions, we will end + +up with a combination of lattice +and symmetry, which is + +something that is called +a plane group-- + +group because the operations +that are present in the space + +follow the requirements of the +mathematical entity called a + +group, plane because this is +a distribution of symmetry + +elements throughout a plane +and not just fixed at one + +particular point. + +Let me finish with some general +observation, and we + +will obtain some of these +rules later on. + +Suppose I take a pristine +space-- + +and this blackboard is +no longer pristine-- + +and I put in the space a +first operation, and + +there's a motif in there. + +This first operation moves +around this first motif and + +gives me a second +one, number two. + +Then I say let me put in +another operation. + +I'd like to combine these +things and see how many + +different combinations +I have, so I put in + +operation number two. + +Operation number two will take +the second object and repeat + +it to a third object. + +Number two is identical to +number one, so this gives me a + +third object reproduced +from the second by + +operation number two. + +Now I have a space, and +sitting in it are two + +different operations and +three different motifs. + +Motif number one and motif +number three are the same darn + +thing because they've been +repeated by symmetry steps, so + +there must automatically be some +third transformation that + +is equal to the combined effect +of going from one to + +two and then from +two to three-- + +going from one to +three directly. + +So this is another truth +about these symmetries. + +Whenever you take two operations +and combine them in + +a space, the net effect of those +two operations is equal + +to a third operation. + +So a question we're going to ask +all along the way until we + +are at the end of the month-- + +if you take a translation and +combine it with a mirror + +plane, what new operation +has to arise? + +If you take two rotation +operations and put them + +together, what third net +operation has to arrive? + +If we have some general rules, +then we can automatically say, + +OK, I'm going to take a square +lattice and I'm going to put + +in a fourfold axis. + +What else is going to pop up +elsewhere within the cell? + +We'll be able to do this +systematically but fairly + +automatically. + +So that's where we're +going from here. + +When we're done, we will have +derived systematically and + +rigorously the sorts of +symmetries that can combine + +symmetries such as rotation and +reflection with a lattice, + +and we will know completely +the different sorts of + +patterns that exist around +us in two dimensions-- + +in floor tiles, brick +work, wrapping + +paper, and plaid shirts. + +We'll pick up at this +point on Thursday. + +Let me caution you we are going +into territory that is + +not covered in Berger's book. + +I've just passed +it out to you. + +What we've said in the early +parts of the term are in + +there, but we're going to do +things in a slightly different + +way and then return to +his text later on. \ No newline at end of file diff --git a/pjLbxB9TXJs.txt b/pjLbxB9TXJs.txt new file mode 100644 index 0000000000000000000000000000000000000000..5c02b80ba26fc8341dc6e885005a68b34a08d4f2 --- /dev/null +++ b/pjLbxB9TXJs.txt @@ -0,0 +1,1627 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: I want to finish up +our little excursion into + +searching and sorting, a very +important topic in computing. + +How do you sort lists +or databases? + +How do you search them? + +And I want to finish +it up with hashing. + +Hashing is how dictionaries +are implemented in Python. + +And this leads to a +very efficient-- + +at least most of the +time-- search. + +But it comes at the +cost of space. + +So this is an example where one +can trade space for time. + +So I want to start +with a simple + +example to explain hashing. + +And I'm going to begin by +assuming that what we're + +hashing is a set of integers. + +So we want to build a set of +integers and detect whether or + +not a particular integer +is in that set. + +And we want to do +that quickly. + +So the basic idea is we're going +to take an integer-- + +call it i-- + +and we're going to hash it. + +I'll tell you what that +means in a minute. + +And what a hash function does +is it converts i to a + +different integer, perhaps, +in some range. + +So it, say, converts i to some +integer in the range 0 to k, + +for some constant k. + +We're going to then use +this integer to index + +into a list of lists. + +So each of these is +called a bucket. + +And a bucket will itself +be a list. + +So this together is +called a bucket. + +We've already seen that we can +find the i-th element of a + +list in constant time. + +So when we ask whether some +integers in this set will hash + +it, we'll go immediately to the +correct bucket, the bucket + +associated with that integer. + +And then we'll search the list +at that bucket to see if the + +integer is there. + +If this list is short enough, +it will be very efficient. + +All, right I realize that's +very abstract. + +But let's look at the code, +which will make + +it much less abstract. + +So the code starts with +something very ugly that I'll + +apologize for. + +But very soon, we'll see +how to get rid of that. + +I'm using a global variable here +to say how many buckets + +there are going to be. + +And I've very arbitrarily +chosen 47. + +I then have a function called +create, which uses this global + +variable and creates a +list of lists, each + +element of which is empty. + +Because initially, we have +no elements in the set. + +When I want to insert an element +in the set, I'll call + +the function insert, which +will hash the element. + +It doesn't actually even need +to use the global numBuckets + +in this case, in fact. + +And then append it to +the correct list. + +So it calls this function +hashElem, which could hardly + +be simpler. + +It just takes the remainder, the +modulus of the element and + +the number of buckets. + +So that will give me a +value between 0 and + +numBuckets minus 1. + +It gives me one of the +list, and I'll just + +insert it at the end. + +When I want to check for +membership, you'll see it's + +quite simple. + +All I do is ask the question, +is i in the list associated + +with the correct bucket? + +Remove is a little bit more +complicated, but in fact, we + +don't need to spend much +time looking at it now. + +It's just some code. + +And the only reason it's +complicated is Insert doesn't + +look whether or not the element +is already there. + +So it may occur multiple +times in the list. + +So I would have to remove +each one of them. + +People see the basic +structure of this? + +Why a list of lists? + +Why don't I just, say, have a +list of Booleans, where I hash + +the integer, and it's true or +false, whether or not I've + +seen it, depending upon the +value of that bucket? + +Why can't I do that? + +Somebody? + +Well, what's the property +of this hash function? + +The key issue here is +the hash function -- + +is many-to-one. + +That is to say, an infinite +number of different integers + +will hash to the same value. + +Because after all, I have +a set in which I + +can store any integer-- + +or any positive integer, +at least-- + +and there are only 47 buckets. + +So it's pretty obvious that many +integers will hash to the + +same bucket. + +When two different elements hash +to the same bucket, we + +have what is called +a collision. + +There are lots of different +ways to handle collisions. + +What I've shown you here is +probably the simplest way, + +which is called linear +rehashing. + +I'm not actually rehashing. + +I'm just keeping a list. + +Does that makes sense? + +Yes, thank you for-- + +I'm glad somebody +has a question. + +You have to ask loudly. + +AUDIENCE: When you take +the modulus 47, + +what does that return? + +PROFESSOR: 0. + +AUDIENCE: So hashElem +always returns 0? + +PROFESSOR: Well, no, sorry. + +It depends what I'm hashing. + +Sorry, I thought if you +were saying that if I + +asked 47 mod 47. + +If I take 48 mod 47, I get 1. + +If I take 49 mod 47-- + +it's the remainder. + +Maybe I should have called +it just the remainder. + +Look up. + +I'm about to throw +something at you. + +Ooh, I threw a curve ball. + +OK. + +What's the complexity here +of the membership test? + +Kind of hard to analyze. + +Roughly speaking, or exactly, +it will be the length of the + +bucket, the size +of the bucket. + +Now, I don't know how +many elements + +will be in the bucket. + +But what will this depend on? + +It will depend upon the +number of buckets. + +If I have a million buckets, +I'll get a lot fewer + +collisions than if I +have two buckets. + +So let's look at an +example here. + +There's a small program +called test. + +I said numBuckets to +47 in this case. + +And then I'm going to create +it, create a set. + +And then I'm going to put a +bunch of integers in it, then + +a few more, just for fun, +including one very big + +integer, just to show +that it works. + +Then I'm going to show you +what the set looks like. + +And in fact, what we'll do is +we'll stop it here and see + +what we get. + +So what we'll see here is, as +you would expect with that + +number of buckets, each of the +small numbers hashes to a + +separate thing. + +That's just the way +remainder works. + +Not surprisingly-- + +in fact, it would be +disappointing if 325 didn't + +have the same value both +times I inserted it. + +So we say we happen to have +one bucket that's got two + +elements in it. + +Happen to be the same. + +But this very big number +happened to hash to the same + +value of 30 as 34. + +So here we have two +elements in it. + +A good hash function has the +property that it will widely + +disperse the values you hash. + +So they end up in different +buckets, rather than some + +stupid hash function that tends +to put everything in the + +same bucket. + +Now, let's see what happens if I +change the number of buckets + +to, say, 3. + +Well, not surprisingly, we get +some very big buckets, because + +there are relatively +few choices. + +So what we see here is we have +a genuine trade off between + +time and space. + +If the number of buckets is +large relative to the number + +of elements that we insert in +the table, then looking at + +whether or not an element in +it is roughly order one. + +Because these lists will +be very short. + +So we can actually look up +something in constant time if + +we dedicate enough space +to the hash table. + +If the hash table +is very small-- + +the reduction ad absurdium +case of one bucket-- + +then it's order n. + +It's not constant time. + +It's linear in the number +of elements. + +Typically, when people use hash +tables, they make the + +hash tables big enough that for +all intents and purposes, + +you can assume that looking +something up is + +constant time, order 1. + +And that, in fact, is what +Python does with dictionaries. + +It hashes the keys and chooses +a big enough table so that + +looking up whether or not +something is in a dictionary + +can be done in constant time. + +If it then notices that the +table is too small, because + +you've ended up putting a lot +of elements in it, it just + +re-does it and gets +a bigger table. + +So hashing is an extremely +powerful technique. + +And it's used all the time for +quite complicated things. + +Now is it useful here only when +we want to store ints? + +No. + +It would be kind of bad +if that were the case. + +In fact, any kind of immutable +object can be hashed. + +Now, you may have wondered +why the keys in + +dicts have to be immutable. + +And that's so that they +can be hashed. + +Why does it have to +be immutable? + +Well, imagine that you +used a list as a key. + +You'd hash it when you put the +list in the hash table. + +But then you might mutate it, +and the next time you hashed + +it, you'd get a different value, +and so you wouldn't be + +able to find it again. + +So you need it to be a kind of +object, where every time you + +apply the hash function, +you get the same value. + +I don't need to show you +that this works. + +You'll just believe +me, I'm sure. + +Let's look at a slightly more +complicated hash function. + +Here, I want to hash something +that could be + +either an int or a string. + +So I first check and +see if it's an int. + +If so, I'll set the +value to be e. + +Then down at the bottom, I'll do +the modulus operator again. + +But if it's a string, +I'm going to first + +convert e to an int. + +And this is basically the trick +that people typically + +use when they're doing hashing, +is they convert + +whatever thing they have, +to some integer. + +People do this with all +sorts of things. + +For example, this is the way +airport security systems today + +do face recognition. + +They hash every picture of a +face to an integer, and then + +look it up. + +So we can see it here. + +The way I'm doing it-- +and the details + +don't very much matter-- + +is I'm going to do it a +character at a time, do a + +shift ord of C, takes the +ASCII, the internal + +representation bits +of each character. + +And again, I don't care +if you understand how + +the code works here. + +What I just want you to see is +that it's not very long. + +And in, fact it's typically +fairly simple to hash almost + +any kind of an object. + +Because deep down, we know +that every object is + +represented by some string of +bits in the computer's memory. + +And we can always convert a +string of bits to an integer. + +All right, so that's hashing, a +very powerful and extremely + +useful technique. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +you're returning something, +will you always find the + +remainder, or can you +use [INAUDIBLE]? + +PROFESSOR: There are many +different ways of doing hash. + +All the hash function has to +do is convert its argument + +into an integer in some way or +another within a fixed range. + +It happens to be that remainder +is a very simple way + +to do that and is often used. + +There's a whole theory +about hash functions. + +You can read about them in +gory detail on Wikipedia. + +The math can actually be quite +complicated, and there's no + +real need to understand it. + +I typically do something like +dividing by a prime number, + +which is known to have +good properties. + +But, again, you can get carried +away with this. + +And it's usually not worth the +trouble, unless you're very + +deeply involved in something. + +OK? + +And then I've got another +program that does this, but + +again, I don't think much +would be served by + +running it for you. + +Any questions about hashing? + +Yes? + +AUDIENCE: So does this only +work because you said + +[INAUDIBLE] + +Python treats lists +in a certain way? + +You said other languages, you +can't have this constant time + +list search. + +So how would hashing work? + +PROFESSOR: So the question is +that, because Python gives us + +constant-time looking up for +lists is the key to making + +this work -- + +every programming language +I know has some + +concept that's similar. + +In, say, C, it's not a list, +but it's an array. + +And so in C, you would use +array for this purpose? + +In Java, you would use the +arrays for this purpose? + +But yes, you can do this in +any programming language, + +because every reasonable +programming language has some + +way to create the equivalent +of a list, in which you can + +get a particular index +in constant time. + +So it's a universally +useful technique. + +Good question. + +Anything else? + +If not, we're about to abandon +searching and sorting, and in + +fact, abandon algorithms +in general for a while. + +Bounced right off his hands. + +I will not sign you to +a baseball contract. + +Pardon? + +Yes, I threw him +a Butterfinger? + +Oh, it's terrible. + +Boy, your jokes are +worse than mine. + +I now want to move +on to the last-- + +go back to Python, away from +algorithms, away from computer + +science in general, and talk +about the last three major + +linguistic concepts in Python, +exceptions, classes, and then + +later iterators. + +Let's start with exceptions, +because we've already seen + +them, and they're +pretty simple. + +Exceptions are everywhere +in Python. + +And we've certainly seen +plenty of them + +all semester already. + +We get them if we set some +list to, say [1,2] + +and then I asked for a test of +12, I get an index error. + +This is an exception. + +We've got exceptions when we've +tried to convert things + +to incorrect types. + +So if I go into test, I'll +get a type error. + +Anything that ends in the word +"error" is a built-in kind of + +exception in Python. + +We've got them when we +accessed, nonexistent + +variables, a name error. + +So there are a whole bunch +of these things. + +In each of these cases-- + +here, I'm just kind of playing +around in Python. + +And it printed an error message, +and it stopped. + +These kind of exceptions are +called unhandled exceptions, + +where they cause the program +to effectively crash. + +The program just +stops running. + +And I suspect that some of you +have written programs in which + +this has happened. + +In fact, is there anybody here +who has not written a program + +that crashed because of an +unhandled exception? + +Good. + +For those of you watching +on TV, no hands went up. + +Almost every day, I write a +program that crashes because + +of an unhandled exception. + +On the other hand, once my +program is debugged-- + +once your program is +debugged-- this + +should never happen. + +Because there are mechanisms +in Python for handling + +exceptions. + +And in fact, as we'll see, it's +a perfectly valid flow of + +control concept. + +You will sometimes write +programs that are intended to + +raise exceptions. + +And then you'll catch the +exception and do something + +useful with it. + +The way we use exceptions +is in something called a + +try-except block. + +So you write the word "try," and +then you have some code, + +and then "except," and +then some more code. + +What the interpreter does is it +starts executing this code. + +If it gets through this code +without raising any kind of an + +exception, it jumps to the code + +following the except block. + +On the other hand, if an +exception gets raised here, it + +immediately stops executing +this code and jumps to the + +start of this code, the code +associated with the except, + +and executes that. + +And, then when it finishes this, +it again goes to the + +code following the except. + +Just like an if, you can +nest these things. + +It's just a control concept. + +It's nothing more. + +Let's look at an example. + +So here's readVal. + +This is a function. + +It's a polymorphic function. + +Its first argument is +of type 'type'. + +Remember-- + +and you'll hear me say this a +1,000 more times at least-- + +in Python, everything is an +object and can be manipulated + +by the program. + +It's one of the beauties +of Python. + +It's something that's not true +in many programming languages. + +So types are objects, just +like ints or floats. + +So the first argument to +readVal is a type. + +And then there are two strings, +the request message + +and the error message. + +It then sets a local variable, +numTries, to 0. + +And while numTries is less than +4, it sets val equal to + +raw input, printing the +request message. + +And then it tries to convert val +to valType, whatever that + +happens to be. + +And if it succeeds, +it returns it. + +On the other hand, if during +this attempt to convert it an + +exception is raised-- + +for example, the user is asked +to input an integer, and they + +type in the letter b, which +can't be converted to an int-- + +then a type error exception +will be raised, or a value + +error exception. + +And if a value error exception +is raised, it prints the error + +message, increases numTries by +1, and goes back to the top of + +the y loop. + +If it goes through this y loop +too many times, it leaves, + +raising the type error with the +message that the argument + +"numTries + +exceeded." All right. + +Let's run this and +see what happens. + +Every once in a while, +funny things happen. + +When that happens, somehow, +clicking in this window, and + +then clicking back in +that window tends to + +make it work again. + +This is a bug in Python. + +So it's now asked me +to enter an int. + +If I enter an int, everything +is good. + +It just prints it. + +On the other hand, if I run it, +and I enter the letter A, + +it will give me another +chance. + +And now I can enter an +int, and it's happy. + +All right. + +Now, suppose I am unhappy with +the fact that if four times in + +a row I've failed to enter an +int, something bad happens. + +It comes back, and it +raises an exception. + +Well, I can catch that in the +code that calls readVal. + +So here at the top level, I'm +going to try readVal. + +And then I'm going to say, +except if a type error is + +raised, print the argument +returned by that exception. + +So this is what's called the +handler for the exception. + +And so I don't have to crash +when the exception is raised. + +But I can actually deal with it +and do something sensible. + +If following the word "except," +as you see over + +there, I have not listed any +exception names, then I'll go + +to the except clause +for all exceptions. + +Doesn't matter what +the exception is. + +I will go there. + +So I can write code that +captures any exception. + +OK. + +Usually, that's not as good a +thing, because it shows that I + +did not anticipate what the +exception might be. + +But you can see that +this is a pretty + +powerful programming paradigm. + +I can write this fairly compact +readVal function + +that's pretty robust. + +It's polymorphic, it can take +in what the error messages + +are, and it can try as +many times as I want. + +Yeah? + +AUDIENCE: [INAUDIBLE] after +type error [INAUDIBLE]? + +AUDIENCE: PROFESSOR: You'll note +that when I raised the + +exception type error after it, I +had an open [UNINTELLIGIBLE] + +a string. + +So what this basically says is +that an exception can have + +associated with it a +set of arguments, + +a sequence of arguments. + +And I've just chosen to call the +first of the arguments s, + +so that I could then print it. + +So this is a fairly common +paradigm, that you associate a + +message with an exception, +explaining the exception. + +Since after all, type error is +not all that meaningful. + +And this tells me why it +was raised, that I + +tried too many times. + +OK, does it make sense? + +Anything else? + +Yeah? + +AUDIENCE: [INAUDIBLE] + +before you said [INAUDIBLE]? + +PROFESSOR: Well, what we'll see +when I execute something + +like assert false, it's actually +raising an exception. + +It's raising an assertion +error exception. + +And so I can actually catch that +and do something with it. + +I've been using these +asserts just + +basically to stop the program. + +But we've also seen that +sometimes in functions, we use + +assertions to check the types +of the arguments. + +But if you don't catch that +exception, then the program + +crashes with the wrong +arguments, without doing + +anything useful. + +Because that's just an +exception, I can catch it, and + +then do something useful. + +So it's, again, just +an example of that. + +We're going to try your +hands once more. + +I'll throw you a different +kind of candy. + +And this time he caught it. + +Two for two. + +Very powerful. + +A very useful mechanism. + +You can use them for sort +of catching errors, + +as we've done here. + +They are frequently used in +situations where you are + +getting input from a user. + +So for example, if you were +writing a text editor, and you + +wanted to open up a file, and +you typed in the file name, + +and it didn't exist, you would +in Python get an error message + +when you try to open +that file. + +It would raise an exception, +"File Not Found," basically, + +which you could then catch, and +then print to the user a + +useful error message saying, +"File Not Found." + +Similarly, if you try and write +to a file that already + +exists, you can get an exception +saying, do you + +really want to overwrite +this file? + +And ask the user. + +So it's very commonly +used in a lot of + +programs as a mechanism. + +And now, as we go on and see +more and more code, you'll see + +that I'm going to start using +exceptions fairly frequently + +as a flow of control +mechanism. + +It makes certain kinds of +code easier to write. + +All right. + +That's all I have to say +about exceptions. + +Simple but useful mechanism. + +Now, on to something +that's even more + +useful, but not so simple. + +It is probably the +distinguishing thing, not only + +in Python, but in +a whole class of + +modern programming languages. + +And that's the notion +of a class. + +I'm not going to finish +it today. + +I'm barely going to scratch +the surface of it today. + +But we're going to start leading +up and I will pretty + +much finish it on Thursday. + +We've already seen the notion of +a module, which has been a + +collection of related +functions. + +So, for example, we've seen code +that includes something + +like import math. + +And that provided me +with access to + +functions like math.log. + +What the module mechanism does +in the import mechanism, it + +makes it convenient +to import a lot of + +related things at once. + +And then we use this dot +notation to disambiguate, to + +tell us, well, which log. + +Typically, there's probably +only one log function. + +But certainly, you might imagine +that set.member and + +table.member would +be different, and + +that both might exist. + +And as we've said before, the +dot notation avoids conflicts + +by disambiguating. + +OK. + +That's a module. + +What a class is, it is like a +module, but it's not just a + +collection of functions. + +A class is a collection of data +and functions, functions + +that operate on that data. + +They are bound together, so that +you can pass an object + +from one part of a program +to another. + +And the part of the program +to which you pass it + +automatically gets access to the +functions associated with + +that type of object. + +And this is really the key +to what people call + +object-oriented programming, +a very popular buzzword. + +So we've already seen that kind +of thing, where if we + +pass a list from one function +to another, we can write + +something like L.append, +some value. + +The data and functions +associated with an object are + +called that object's +attributes. + +So you can think of this as a +way to associate attributes + +with objects. + +Now, I've been talking about +data and functions as if + +they're different +kinds of things. + +In fact, they're not really, +because they're just objects. + +In Python, everything is an +object, including, as we'll + +see on Thursday, the class +itself is an object. + +When people talk about objects +and object-oriented + +programming, they often use a +message passing metaphor. + +And I want to emphasize it's +nothing more than a metaphor. + +And I almost hesitate to bring +it up, because it makes it all + +sound more complicated +than it is. + +But you will see this phrase +in the literature. + +People will use it. + +So you need to know +what it is. + +The basic metaphor is that when +I write something like + +L.append, I am passing the +message append e to the object + +L. And then there's a mechanism +for looking up what + +that object means, what +that message means. + +And then the object, L, executes +that message, and + +does something. + +So, for example, if I had a +class called Circle, I might + +pass the object C -- + +the message area, which would +cause this object to return + +the area of its own area, the +area of the circle that is + +that object. + +Again, nothing dramatic +going on here. + +If you just think of this as +a fancy way of writing + +functions, you'll be +absolutely correct. + +But I did think you should +hear about this metaphor. + +I add by the way -- +should have-- + +I've been using the word... + +Method is a function associated +with an object. + +So in this case, the method area +is associated with the + +object C. And purists would say, +always refer to append as + +a method, rather than a +function, because we use the + +dot notation to get to it, and +it's always associated with + +some object of type list. + +Now, just as data can have +types, objects, as we know, + +have types. + +What a class is is it's a +collection of objects with + +identical characteristics +that form a type. + +So we can use classes to +introduce new types into the + +programming environment. + +So as you think about +existing things-- + +now, I won't put that up, +because it will disappear + +behind the screen. + +We've looked at things +like lists and dict. + +What these are are +built-in classes. + +They happen to be classes that +are so useful that somebody + +decided they should be part of +the language, they should have + +efficient implementations, +they should be built-in, + +people shouldn't have to +reimplement them themselves. + +And in fact, there are a whole +bunch of interesting built-in + +classes in Python. + +And there are a whole bunch of +libraries of classes you can + +bring in-- and we'll look +at many of those-- + +that extend it. + +And that's the beauty of +the class mechanism. + +It lets you add new types to +the language that are every + +bit as easy to use as +the built-in types. + +So in effect, the language can +be extended to add new and + +useful types. + +And we'll look at several +examples of + +that starting on Thursday. \ No newline at end of file diff --git a/pyJJ3oRlorM.txt b/pyJJ3oRlorM.txt new file mode 100644 index 0000000000000000000000000000000000000000..5add1c13e169f0ea9a3bbc7497dfe9f25f1b9961 --- /dev/null +++ b/pyJJ3oRlorM.txt @@ -0,0 +1,11547 @@ +align:start position:0% + +today we are going to be discussing + + align:start position:0% +today we are going to be discussing + + + align:start position:0% +today we are going to be discussing +neutral particle + + align:start position:0% + + + + align:start position:0% + +Diagnostics + + align:start position:0% +Diagnostics + + + align:start position:0% +Diagnostics +so the fact of the matter is we have + + align:start position:0% +so the fact of the matter is we have + + + align:start position:0% +so the fact of the matter is we have +some plasma like a + + align:start position:0% +some plasma like a + + + align:start position:0% +some plasma like a +and it has some flux surfaces and we + + align:start position:0% +and it has some flux surfaces and we + + + align:start position:0% +and it has some flux surfaces and we +want to know what's going on inside the + + align:start position:0% +want to know what's going on inside the + + + align:start position:0% +want to know what's going on inside the +core because this is where the fusion is + + align:start position:0% +core because this is where the fusion is + + + align:start position:0% +core because this is where the fusion is +happening in particular we want to know + + align:start position:0% +happening in particular we want to know + + + align:start position:0% +happening in particular we want to know +what the distribution function of the + + align:start position:0% +what the distribution function of the + + + align:start position:0% +what the distribution function of the +ions is it's probably maxwellian is but + + align:start position:0% +ions is it's probably maxwellian is but + + + align:start position:0% +ions is it's probably maxwellian is but +the ish is the interesting bit there may + + align:start position:0% +the ish is the interesting bit there may + + + align:start position:0% +the ish is the interesting bit there may +be some lovely Tales of particles here + + align:start position:0% +be some lovely Tales of particles here + + + align:start position:0% +be some lovely Tales of particles here +and those are the ones that might be + + align:start position:0% +and those are the ones that might be + + + align:start position:0% +and those are the ones that might be +doing most of our Fusion reactions so + + align:start position:0% +doing most of our Fusion reactions so + + + align:start position:0% +doing most of our Fusion reactions so +we'd like to be able to measure this + + align:start position:0% +we'd like to be able to measure this + + + align:start position:0% +we'd like to be able to measure this +distribution function f ofi the trouble + + align:start position:0% +distribution function f ofi the trouble + + + align:start position:0% +distribution function f ofi the trouble +is the particles the core are hopefully + + align:start position:0% +is the particles the core are hopefully + + + align:start position:0% +is the particles the core are hopefully +very well + + align:start position:0% +very well + + + align:start position:0% +very well +confined if they're not confined we + + align:start position:0% +confined if they're not confined we + + + align:start position:0% +confined if they're not confined we +haven't done a very good job so we can't + + align:start position:0% +haven't done a very good job so we can't + + + align:start position:0% +haven't done a very good job so we can't +exactly wait for them to wander out and + + align:start position:0% +exactly wait for them to wander out and + + + align:start position:0% +exactly wait for them to wander out and +see what they're up to uh and so we need + + align:start position:0% +see what they're up to uh and so we need + + + align:start position:0% +see what they're up to uh and so we need +some technique of measuring uh this core + + align:start position:0% +some technique of measuring uh this core + + + align:start position:0% +some technique of measuring uh this core +distribution function f of IV now we + + align:start position:0% +distribution function f of IV now we + + + align:start position:0% +distribution function f of IV now we +have some ideas based on some of the + + align:start position:0% +have some ideas based on some of the + + + align:start position:0% +have some ideas based on some of the +other Diagnostics we've looked at + + align:start position:0% +other Diagnostics we've looked at + + + align:start position:0% +other Diagnostics we've looked at +already for example we could use + + align:start position:0% +already for example we could use + + + align:start position:0% +already for example we could use +electron cyclotron emission that gave us + + align:start position:0% +electron cyclotron emission that gave us + + + align:start position:0% +electron cyclotron emission that gave us +information about what's going on in the + + align:start position:0% +information about what's going on in the + + + align:start position:0% +information about what's going on in the +core but this gives us a measurement of + + align:start position:0% +core but this gives us a measurement of + + + align:start position:0% +core but this gives us a measurement of +te and te does not necessarily have to + + align:start position:0% +te and te does not necessarily have to + + + align:start position:0% +te and te does not necessarily have to +be the same as ti so that's not a very + + align:start position:0% +be the same as ti so that's not a very + + + align:start position:0% +be the same as ti so that's not a very +good diagnostic we could do something + + align:start position:0% +good diagnostic we could do something + + + align:start position:0% +good diagnostic we could do something +using uh laser induced fluoresence or + + align:start position:0% +using uh laser induced fluoresence or + + + align:start position:0% +using uh laser induced fluoresence or +two Photon absorption laser induced + + align:start position:0% +two Photon absorption laser induced + + + align:start position:0% +two Photon absorption laser induced +fluoresence like this if you remember + + align:start position:0% +fluoresence like this if you remember + + + align:start position:0% +fluoresence like this if you remember +that's where we had an upper level and a + + align:start position:0% +that's where we had an upper level and a + + + align:start position:0% +that's where we had an upper level and a +lower level and we scanned our laser + + align:start position:0% +lower level and we scanned our laser + + + align:start position:0% +lower level and we scanned our laser +wavelength in frequency space here so + + align:start position:0% +wavelength in frequency space here so + + + align:start position:0% +wavelength in frequency space here so +that we could address particles which + + align:start position:0% +that we could address particles which + + + align:start position:0% +that we could address particles which +were doter shifted towards us and do + + align:start position:0% +were doter shifted towards us and do + + + align:start position:0% +were doter shifted towards us and do +shifted away from us and by looking at + + align:start position:0% +shifted away from us and by looking at + + + align:start position:0% +shifted away from us and by looking at +the intensity of light coming out we + + align:start position:0% +the intensity of light coming out we + + + align:start position:0% +the intensity of light coming out we +could measure this distribution function + + align:start position:0% +could measure this distribution function + + + align:start position:0% +could measure this distribution function +here so this looks like a pretty good + + align:start position:0% +here so this looks like a pretty good + + + align:start position:0% +here so this looks like a pretty good +technique for measuring the core uh the + + align:start position:0% +technique for measuring the core uh the + + + align:start position:0% +technique for measuring the core uh the +trouble is that in the core all of our + + align:start position:0% +trouble is that in the core all of our + + + align:start position:0% +trouble is that in the core all of our +particles are fully ionized and so there + + align:start position:0% +particles are fully ionized and so there + + + align:start position:0% +particles are fully ionized and so there +are no electrons here so we can't use + + align:start position:0% +are no electrons here so we can't use + + + align:start position:0% +are no electrons here so we can't use +these techniques because there are no + + align:start position:0% +these techniques because there are no + + + align:start position:0% +these techniques because there are no +ions with an electron in them in order + + align:start position:0% +ions with an electron in them in order + + + align:start position:0% +ions with an electron in them in order +for us to be able to address it using + + align:start position:0% +for us to be able to address it using + + + align:start position:0% +for us to be able to address it using +our laser and thirdly we could also use + + align:start position:0% +our laser and thirdly we could also use + + + align:start position:0% +our laser and thirdly we could also use +Thompson scattering which we haven't + + align:start position:0% +Thompson scattering which we haven't + + + align:start position:0% +Thompson scattering which we haven't +about yet but we will do in detail soon + + align:start position:0% +about yet but we will do in detail soon + + + align:start position:0% +about yet but we will do in detail soon +the trouble with Thompson scattering is + + align:start position:0% +the trouble with Thompson scattering is + + + align:start position:0% +the trouble with Thompson scattering is +that it tends to give us information + + align:start position:0% +that it tends to give us information + + + align:start position:0% +that it tends to give us information +scattering about the electron + + align:start position:0% +scattering about the electron + + + align:start position:0% +scattering about the electron +distribution function f of or Fe V like + + align:start position:0% +distribution function f of or Fe V like + + + align:start position:0% +distribution function f of or Fe V like +that and again that doesn't have to + + align:start position:0% +that and again that doesn't have to + + + align:start position:0% +that and again that doesn't have to +necessarily be the same as the ion + + align:start position:0% +necessarily be the same as the ion + + + align:start position:0% +necessarily be the same as the ion +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +function so we're going to need a new + + align:start position:0% +function so we're going to need a new + + + align:start position:0% +function so we're going to need a new +technique in order to measure the + + align:start position:0% +technique in order to measure the + + + align:start position:0% +technique in order to measure the +distribution of these core particles so + + align:start position:0% +distribution of these core particles so + + + align:start position:0% +distribution of these core particles so +the idea + + align:start position:0% +the idea + + + align:start position:0% +the idea +is well what if spontaneously some of + + align:start position:0% +is well what if spontaneously some of + + + align:start position:0% +is well what if spontaneously some of +these core ions turned into + + align:start position:0% + + + + align:start position:0% + +neutrals + + align:start position:0% +neutrals + + + align:start position:0% +neutrals +well if some of these core ions turned + + align:start position:0% +well if some of these core ions turned + + + align:start position:0% +well if some of these core ions turned +into + + align:start position:0% +into + + + align:start position:0% +into +neutrals then they would no longer be + + align:start position:0% +neutrals then they would no longer be + + + align:start position:0% +neutrals then they would no longer be +confined they would be able to wander + + align:start position:0% +confined they would be able to wander + + + align:start position:0% +confined they would be able to wander +freely + + align:start position:0% +freely + + + align:start position:0% +freely +out and perhaps we could stick a + + align:start position:0% +out and perhaps we could stick a + + + align:start position:0% +out and perhaps we could stick a +detector on the outside of the plasma + + align:start position:0% +detector on the outside of the plasma + + + align:start position:0% +detector on the outside of the plasma +and measure these neutrals which will + + align:start position:0% +and measure these neutrals which will + + + align:start position:0% +and measure these neutrals which will +carry with them some information about + + align:start position:0% +carry with them some information about + + + align:start position:0% +carry with them some information about +the ion distribution they came from and + + align:start position:0% +the ion distribution they came from and + + + align:start position:0% +the ion distribution they came from and +that will allow us to indirectly measure + + align:start position:0% +that will allow us to indirectly measure + + + align:start position:0% +that will allow us to indirectly measure +the ion + + align:start position:0% +the ion + + + align:start position:0% +the ion +distribution so uh what's a good way to + + align:start position:0% +distribution so uh what's a good way to + + + align:start position:0% +distribution so uh what's a good way to +summarize they're gonna these neutrals + + align:start position:0% +summarize they're gonna these neutrals + + + align:start position:0% +summarize they're gonna these neutrals +would give us information + + align:start position:0% +would give us information + + + align:start position:0% +would give us information +on the distribution function so there's + + align:start position:0% +on the distribution function so there's + + + align:start position:0% +on the distribution function so there's +two problems that's come to your mind + + align:start position:0% +two problems that's come to your mind + + + align:start position:0% +two problems that's come to your mind +straight away why exactly was an ion + + align:start position:0% +straight away why exactly was an ion + + + align:start position:0% +straight away why exactly was an ion +suddenly turn itself into a neutral in + + align:start position:0% +suddenly turn itself into a neutral in + + + align:start position:0% +suddenly turn itself into a neutral in +the core and does it stand a chance of + + align:start position:0% +the core and does it stand a chance of + + + align:start position:0% +the core and does it stand a chance of +actually escaping from the core to the + + align:start position:0% +actually escaping from the core to the + + + align:start position:0% +actually escaping from the core to the +outside where we can detect it uh and so + + align:start position:0% +outside where we can detect it uh and so + + + align:start position:0% +outside where we can detect it uh and so +we'll talk about those two issues one + + align:start position:0% +we'll talk about those two issues one + + + align:start position:0% +we'll talk about those two issues one +after the other so first of all is the + + align:start position:0% +after the other so first of all is the + + + align:start position:0% +after the other so first of all is the +uh NE neutral + + align:start position:0% + + + + align:start position:0% + +production and I guess we could call the + + align:start position:0% +production and I guess we could call the + + + align:start position:0% +production and I guess we could call the +second problem neutral + + align:start position:0% + + + + align:start position:0% + +transport so in terms of neutral + + align:start position:0% +transport so in terms of neutral + + + align:start position:0% +transport so in terms of neutral +production there are two major processes + + align:start position:0% +production there are two major processes + + + align:start position:0% +production there are two major processes +that we could have we could have a + + align:start position:0% +that we could have we could have a + + + align:start position:0% +that we could have we could have a +charge exchange so I'm just going to + + align:start position:0% +charge exchange so I'm just going to + + + align:start position:0% +charge exchange so I'm just going to +write that as CX uh we talked about + + align:start position:0% +write that as CX uh we talked about + + + align:start position:0% +write that as CX uh we talked about +charge exchange before this is where a + + align:start position:0% +charge exchange before this is where a + + + align:start position:0% +charge exchange before this is where a +neutral collides with an ion and the + + align:start position:0% +neutral collides with an ion and the + + + align:start position:0% +neutral collides with an ion and the +neutral loses an electron and the ion + + align:start position:0% +neutral loses an electron and the ion + + + align:start position:0% +neutral loses an electron and the ion +gains an electron so we could have + + align:start position:0% +gains an electron so we could have + + + align:start position:0% +gains an electron so we could have +charge exchange with Edge + + align:start position:0% +charge exchange with Edge + + + align:start position:0% +charge exchange with Edge +neutrals so they could be neutrals + + align:start position:0% +neutrals so they could be neutrals + + + align:start position:0% +neutrals so they could be neutrals +coming in from the edge of the + + align:start position:0% + + + + align:start position:0% + +plasma and that would look like some + + align:start position:0% +plasma and that would look like some + + + align:start position:0% +plasma and that would look like some +neutrals coming in like this and I'll + + align:start position:0% +neutrals coming in like this and I'll + + + align:start position:0% +neutrals coming in like this and I'll +use N Sub a to be like some density of + + align:start position:0% +use N Sub a to be like some density of + + + align:start position:0% +use N Sub a to be like some density of +neutral atoms these are going to be + + align:start position:0% +neutral atoms these are going to be + + + align:start position:0% +neutral atoms these are going to be +wandering in from the edge all the time + + align:start position:0% +wandering in from the edge all the time + + + align:start position:0% +wandering in from the edge all the time +maybe a few of them make it to the + + align:start position:0% +maybe a few of them make it to the + + + align:start position:0% +maybe a few of them make it to the +center and then they charge exchange of + + align:start position:0% +center and then they charge exchange of + + + align:start position:0% +center and then they charge exchange of +our core and then those + + align:start position:0% + + + + align:start position:0% + +core then the ions make it back out + + align:start position:0% +core then the ions make it back out + + + align:start position:0% +core then the ions make it back out +again and we can detect it that's one + + align:start position:0% +again and we can detect it that's one + + + align:start position:0% +again and we can detect it that's one +possible + + align:start position:0% +possible + + + align:start position:0% +possible +mechanism uh a more active mechanism + + align:start position:0% +mechanism uh a more active mechanism + + + align:start position:0% +mechanism uh a more active mechanism +will be taking a neutral beam and + + align:start position:0% +will be taking a neutral beam and + + + align:start position:0% +will be taking a neutral beam and +putting a neutral beam into the center + + align:start position:0% +putting a neutral beam into the center + + + align:start position:0% +putting a neutral beam into the center +of the core here this is neutral beam + + align:start position:0% +of the core here this is neutral beam + + + align:start position:0% +of the core here this is neutral beam +injection we use neutral beam injection + + align:start position:0% +injection we use neutral beam injection + + + align:start position:0% +injection we use neutral beam injection +for all sorts of things like current + + align:start position:0% +for all sorts of things like current + + + align:start position:0% +for all sorts of things like current +drive and heating of the plasma and so + + align:start position:0% +drive and heating of the plasma and so + + + align:start position:0% +drive and heating of the plasma and so +we often have this process happening + + align:start position:0% +we often have this process happening + + + align:start position:0% +we often have this process happening +automatically the whole point of the + + align:start position:0% +automatically the whole point of the + + + align:start position:0% +automatically the whole point of the +neutral beam here is that as these + + align:start position:0% +neutral beam here is that as these + + + align:start position:0% +neutral beam here is that as these +neutral particles come into the center + + align:start position:0% +neutral particles come into the center + + + align:start position:0% +neutral particles come into the center +they'll charge exchange with the ions + + align:start position:0% +they'll charge exchange with the ions + + + align:start position:0% +they'll charge exchange with the ions +and become ions but that means that the + + align:start position:0% +and become ions but that means that the + + + align:start position:0% +and become ions but that means that the +ions they've charge exchange will become + + align:start position:0% +ions they've charge exchange will become + + + align:start position:0% +ions they've charge exchange will become +neutrals and so those neutrals May uh + + align:start position:0% +neutrals and so those neutrals May uh + + + align:start position:0% +neutrals and so those neutrals May uh +come out the the plasma here where we + + align:start position:0% +come out the the plasma here where we + + + align:start position:0% +come out the the plasma here where we +can detect them so we have charge + + align:start position:0% +can detect them so we have charge + + + align:start position:0% +can detect them so we have charge +exchange with Edge neutrals and charge + + align:start position:0% +exchange with Edge neutrals and charge + + + align:start position:0% +exchange with Edge neutrals and charge +exchange with neutral beam + + align:start position:0% + + + + align:start position:0% + +injection neutral transport is asking + + align:start position:0% +injection neutral transport is asking + + + align:start position:0% +injection neutral transport is asking +can the neutral make it from the center + + align:start position:0% +can the neutral make it from the center + + + align:start position:0% +can the neutral make it from the center +of the + + align:start position:0% + + + + align:start position:0% + +core here can that neutral make it + + align:start position:0% +core here can that neutral make it + + + align:start position:0% +core here can that neutral make it +out along some path and so there's going + + align:start position:0% +out along some path and so there's going + + + align:start position:0% +out along some path and so there's going +to be a series of processes which are + + align:start position:0% +to be a series of processes which are + + + align:start position:0% +to be a series of processes which are +trying to to reionize this neutral as it + + align:start position:0% +trying to to reionize this neutral as it + + + align:start position:0% +trying to to reionize this neutral as it +tries to leave the plasma so these + + align:start position:0% +tries to leave the plasma so these + + + align:start position:0% +tries to leave the plasma so these +processes are going to be things like + + align:start position:0% +processes are going to be things like + + + align:start position:0% +processes are going to be things like +I'm going to give them their + + align:start position:0% +I'm going to give them their + + + align:start position:0% +I'm going to give them their +cross-sections Sigma sub this is + + align:start position:0% +cross-sections Sigma sub this is + + + align:start position:0% +cross-sections Sigma sub this is +electron impact ionization which we + + align:start position:0% +electron impact ionization which we + + + align:start position:0% +electron impact ionization which we +talked about + + align:start position:0% + + + + align:start position:0% + +before this is going to be we're going + + align:start position:0% +before this is going to be we're going + + + align:start position:0% +before this is going to be we're going +to use Sigma subscript P this is Ion + + align:start position:0% +to use Sigma subscript P this is Ion + + + align:start position:0% +to use Sigma subscript P this is Ion +impact ionization because we can also + + align:start position:0% +impact ionization because we can also + + + align:start position:0% +impact ionization because we can also +have collisions of ions causing + + align:start position:0% +have collisions of ions causing + + + align:start position:0% +have collisions of ions causing +ionization here and finally we can have + + align:start position:0% +ionization here and finally we can have + + + align:start position:0% +ionization here and finally we can have +the probability of charge exchange with + + align:start position:0% +the probability of charge exchange with + + + align:start position:0% +the probability of charge exchange with +ions so if we've charge exchanged once + + align:start position:0% +ions so if we've charge exchanged once + + + align:start position:0% +ions so if we've charge exchanged once +in order to get our Neutron in the first + + align:start position:0% +in order to get our Neutron in the first + + + align:start position:0% +in order to get our Neutron in the first +place it's not at all impossible for us + + align:start position:0% +place it's not at all impossible for us + + + align:start position:0% +place it's not at all impossible for us +to charge exchange again as we head out + + align:start position:0% +to charge exchange again as we head out + + + align:start position:0% +to charge exchange again as we head out +and then our core neutral that was + + align:start position:0% +and then our core neutral that was + + + align:start position:0% +and then our core neutral that was +heading out and giving us information + + align:start position:0% +heading out and giving us information + + + align:start position:0% +heading out and giving us information +about the core will become an ion it be + + align:start position:0% +about the core will become an ion it be + + + align:start position:0% +about the core will become an ion it be +trapped again and now we'll have a ion + + align:start position:0% +trapped again and now we'll have a ion + + + align:start position:0% +trapped again and now we'll have a ion +from further out become a neutral and + + align:start position:0% +from further out become a neutral and + + + align:start position:0% +from further out become a neutral and +that will try and Le so this charge EXT + + align:start position:0% +that will try and Le so this charge EXT + + + align:start position:0% +that will try and Le so this charge EXT +change process is particularly + + align:start position:0% +change process is particularly + + + align:start position:0% +change process is particularly +problematic because what we're ending up + + align:start position:0% +problematic because what we're ending up + + + align:start position:0% +problematic because what we're ending up +with is something that looks like a + + align:start position:0% +with is something that looks like a + + + align:start position:0% +with is something that looks like a +hydrogen neutral plus a hydrogen ion + + align:start position:0% +hydrogen neutral plus a hydrogen ion + + + align:start position:0% +hydrogen neutral plus a hydrogen ion +going to a hydrogen ion plus a hydrogen + + align:start position:0% +going to a hydrogen ion plus a hydrogen + + + align:start position:0% +going to a hydrogen ion plus a hydrogen +neutral now the beautiful symmetry in + + align:start position:0% +neutral now the beautiful symmetry in + + + align:start position:0% +neutral now the beautiful symmetry in +this equation here means that this is + + align:start position:0% +this equation here means that this is + + + align:start position:0% +this equation here means that this is +resonant and so it's quite likely to + + align:start position:0% +resonant and so it's quite likely to + + + align:start position:0% +resonant and so it's quite likely to +happen so this Sigma C is + + align:start position:0% + + + + align:start position:0% + +large okay so that's an overview of what + + align:start position:0% +large okay so that's an overview of what + + + align:start position:0% +large okay so that's an overview of what +we're going to try and do I'm going to + + align:start position:0% +we're going to try and do I'm going to + + + align:start position:0% +we're going to try and do I'm going to +talk a little bit about the neutral + + align:start position:0% +talk a little bit about the neutral + + + align:start position:0% +talk a little bit about the neutral +transport estimate the size of these + + align:start position:0% +transport estimate the size of these + + + align:start position:0% +transport estimate the size of these +different coefficients and work out How + + align:start position:0% +different coefficients and work out How + + + align:start position:0% +different coefficients and work out How +likely it is we can actually get any + + align:start position:0% +likely it is we can actually get any + + + align:start position:0% +likely it is we can actually get any +neutrals from the core back out again + + align:start position:0% +neutrals from the core back out again + + + align:start position:0% +neutrals from the core back out again +and then we'll talk about the neutral + + align:start position:0% +and then we'll talk about the neutral + + + align:start position:0% +and then we'll talk about the neutral +Productions I'm going to go two and then + + align:start position:0% +Productions I'm going to go two and then + + + align:start position:0% +Productions I'm going to go two and then +one but that's an overview if you have + + align:start position:0% +one but that's an overview if you have + + + align:start position:0% +one but that's an overview if you have +any questions before we get going this + + align:start position:0% +any questions before we get going this + + + align:start position:0% +any questions before we get going this +is a good time to + + align:start position:0% + + + + align:start position:0% + +ask + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yes you should take a closer look at + + align:start position:0% +yes you should take a closer look at + + + align:start position:0% +yes you should take a closer look at +Hutchinson's Book for a more formal + + align:start position:0% +Hutchinson's Book for a more formal + + + align:start position:0% +Hutchinson's Book for a more formal +definition um but Quantum mechanically + + align:start position:0% +definition um but Quantum mechanically + + + align:start position:0% +definition um but Quantum mechanically +this is nice and likely to happen + + align:start position:0% +this is nice and likely to happen + + + align:start position:0% +this is nice and likely to happen +because we're sort of starting or ending + + align:start position:0% +because we're sort of starting or ending + + + align:start position:0% +because we're sort of starting or ending +up with something very similar to what + + align:start position:0% +up with something very similar to what + + + align:start position:0% +up with something very similar to what +we've started and so this process is is + + align:start position:0% +we've started and so this process is is + + + align:start position:0% +we've started and so this process is is +likely to occur + + align:start position:0% +likely to occur + + + align:start position:0% +likely to occur +yeah + + align:start position:0% + + + + align:start position:0% + +okay so again we've got some blob of + + align:start position:0% +okay so again we've got some blob of + + + align:start position:0% +okay so again we've got some blob of +plasma here we've got some particle + + align:start position:0% +plasma here we've got some particle + + + align:start position:0% +plasma here we've got some particle +which is born at a point a and we want + + align:start position:0% +which is born at a point a and we want + + + align:start position:0% +which is born at a point a and we want +to know if we can get to a point B like + + align:start position:0% +to know if we can get to a point B like + + + align:start position:0% +to know if we can get to a point B like +this so this is the + + align:start position:0% +this so this is the + + + align:start position:0% +this so this is the +core and B is where we have our + + align:start position:0% + + + + align:start position:0% + +detector if you look at this you say oh + + align:start position:0% +detector if you look at this you say oh + + + align:start position:0% +detector if you look at this you say oh +this looks an awful lot like our + + align:start position:0% +this looks an awful lot like our + + + align:start position:0% +this looks an awful lot like our +radiation transport problem and so we + + align:start position:0% +radiation transport problem and so we + + + align:start position:0% +radiation transport problem and so we +could say that there's a probability of + + align:start position:0% +could say that there's a probability of + + + align:start position:0% +could say that there's a probability of +the particle getting from A to B or this + + align:start position:0% +the particle getting from A to B or this + + + align:start position:0% +the particle getting from A to B or this +could be a power of particles as well if + + align:start position:0% +could be a power of particles as well if + + + align:start position:0% +could be a power of particles as well if +I multiply it by the particle energy per + + align:start position:0% +I multiply it by the particle energy per + + + align:start position:0% +I multiply it by the particle energy per +unit time and that's going to look like + + align:start position:0% +unit time and that's going to look like + + + align:start position:0% +unit time and that's going to look like +the exponential of the line integral + + align:start position:0% +the exponential of the line integral + + + align:start position:0% +the exponential of the line integral +from A to B of some opacity in this case + + align:start position:0% +from A to B of some opacity in this case + + + align:start position:0% +from A to B of some opacity in this case +sort of more to do with scattering than + + align:start position:0% +sort of more to do with scattering than + + + align:start position:0% +sort of more to do with scattering than +it is to do with + + align:start position:0% +it is to do with + + + align:start position:0% +it is to do with +absorption which varies along the path + + align:start position:0% +absorption which varies along the path + + + align:start position:0% +absorption which varies along the path +integrated along the path the L and as a + + align:start position:0% +integrated along the path the L and as a + + + align:start position:0% +integrated along the path the L and as a +minus + + align:start position:0% +minus + + + align:start position:0% +minus +sign okay so again this looks like + + align:start position:0% +sign okay so again this looks like + + + align:start position:0% +sign okay so again this looks like +radiation + + align:start position:0% + + + + align:start position:0% + +power + + align:start position:0% + + + + align:start position:0% + +so we talked about three different + + align:start position:0% +so we talked about three different + + + align:start position:0% +so we talked about three different +processes over there which might be + + align:start position:0% +processes over there which might be + + + align:start position:0% +processes over there which might be +important um and the importance of those + + align:start position:0% +important um and the importance of those + + + align:start position:0% +important um and the importance of those +different processes will depend a lot on + + align:start position:0% +different processes will depend a lot on + + + align:start position:0% +different processes will depend a lot on +the distribution functions that we have + + align:start position:0% +the distribution functions that we have + + + align:start position:0% +the distribution functions that we have +here so if this is V and this is f of V + + align:start position:0% +here so if this is V and this is f of V + + + align:start position:0% +here so if this is V and this is f of V +here we'll have an ion distribution + + align:start position:0% +here we'll have an ion distribution + + + align:start position:0% +here we'll have an ion distribution +function that's just the ions making up + + align:start position:0% +function that's just the ions making up + + + align:start position:0% +function that's just the ions making up +the plasma and that will be relatively + + align:start position:0% +the plasma and that will be relatively + + + align:start position:0% +the plasma and that will be relatively +uh small in velocity space here so this + + align:start position:0% +uh small in velocity space here so this + + + align:start position:0% +uh small in velocity space here so this +is f of I and we'll also have an + + align:start position:0% +is f of I and we'll also have an + + + align:start position:0% +is f of I and we'll also have an +electron distribution + + align:start position:0% +electron distribution + + + align:start position:0% +electron distribution +function which is much broader and + + align:start position:0% +function which is much broader and + + + align:start position:0% +function which is much broader and +that's because the electrons are less + + align:start position:0% +that's because the electrons are less + + + align:start position:0% +that's because the electrons are less +massive so for a similar temperature + + align:start position:0% +massive so for a similar temperature + + + align:start position:0% +massive so for a similar temperature +they have fire higher velocities and + + align:start position:0% +they have fire higher velocities and + + + align:start position:0% +they have fire higher velocities and +we'll also assume that our neutrals + + align:start position:0% +we'll also assume that our neutrals + + + align:start position:0% +we'll also assume that our neutrals +coming out here have some + + align:start position:0% +coming out here have some + + + align:start position:0% +coming out here have some +distribution that is relatively narrow + + align:start position:0% +distribution that is relatively narrow + + + align:start position:0% +distribution that is relatively narrow +and uh shifted like this so this is at a + + align:start position:0% +and uh shifted like this so this is at a + + + align:start position:0% +and uh shifted like this so this is at a +velocity e like this for the + + align:start position:0% +velocity e like this for the + + + align:start position:0% +velocity e like this for the +neutrals and so we're assuming here to + + align:start position:0% +neutrals and so we're assuming here to + + + align:start position:0% +neutrals and so we're assuming here to +make our calculations that the ion + + align:start position:0% +make our calculations that the ion + + + align:start position:0% +make our calculations that the ion +velocities are all much less than these + + align:start position:0% +velocities are all much less than these + + + align:start position:0% +velocities are all much less than these +core neutral velocities and this means + + align:start position:0% +core neutral velocities and this means + + + align:start position:0% +core neutral velocities and this means +that VI minus VA is + + align:start position:0% +that VI minus VA is + + + align:start position:0% +that VI minus VA is +about VA is useful when we're working + + align:start position:0% +about VA is useful when we're working + + + align:start position:0% +about VA is useful when we're working +out these cross-sections that have the + + align:start position:0% +out these cross-sections that have the + + + align:start position:0% +out these cross-sections that have the +difference between the two velocity + + align:start position:0% +difference between the two velocity + + + align:start position:0% +difference between the two velocity +populations and then we can write down + + align:start position:0% +populations and then we can write down + + + align:start position:0% +populations and then we can write down +that our attenuation coefficient Alpha + + align:start position:0% +that our attenuation coefficient Alpha + + + align:start position:0% +that our attenuation coefficient Alpha +here is going to look like one upon the + + align:start position:0% +here is going to look like one upon the + + + align:start position:0% +here is going to look like one upon the +a the electron impact uh cross-section + + align:start position:0% +a the electron impact uh cross-section + + + align:start position:0% +a the electron impact uh cross-section +Sigma e v evaluated + + align:start position:0% +Sigma e v evaluated + + + align:start position:0% +Sigma e v evaluated +VA + + align:start position:0% +VA + + + align:start position:0% +VA +NE + + align:start position:0% +NE + + + align:start position:0% +NE +plus the ion impact ionization Sigma P + + align:start position:0% +plus the ion impact ionization Sigma P + + + align:start position:0% +plus the ion impact ionization Sigma P +VI evaluated + + align:start position:0% +VI evaluated + + + align:start position:0% +VI evaluated +VA and that's times ni + + align:start position:0% +VA and that's times ni + + + align:start position:0% +VA and that's times ni +plus the charge exchange cross-section + + align:start position:0% +plus the charge exchange cross-section + + + align:start position:0% +plus the charge exchange cross-section +Sigma C VI evaluated at VA Times by N + + align:start position:0% +Sigma C VI evaluated at VA Times by N + + + align:start position:0% +Sigma C VI evaluated at VA Times by N +I like + + align:start position:0% + + + + align:start position:0% + +that um and we'll also now assume that + + align:start position:0% +that um and we'll also now assume that + + + align:start position:0% +that um and we'll also now assume that +our beam velocity is much less than or + + align:start position:0% +our beam velocity is much less than or + + + align:start position:0% +our beam velocity is much less than or +the sorry the neutral atom velocity the + + align:start position:0% +the sorry the neutral atom velocity the + + + align:start position:0% +the sorry the neutral atom velocity the +neutrals trying to get out of the plasma + + align:start position:0% +neutrals trying to get out of the plasma + + + align:start position:0% +neutrals trying to get out of the plasma +is much less than the sort of average + + align:start position:0% +is much less than the sort of average + + + align:start position:0% +is much less than the sort of average +thermal velocity of the electrons so + + align:start position:0% +thermal velocity of the electrons so + + + align:start position:0% +thermal velocity of the electrons so +that we can have this nice ordering + + align:start position:0% +that we can have this nice ordering + + + align:start position:0% +that we can have this nice ordering +where VI is much less than VA much less + + align:start position:0% +where VI is much less than VA much less + + + align:start position:0% +where VI is much less than VA much less +than + + align:start position:0% +than + + + align:start position:0% +than +VTE and that allows us to further + + align:start position:0% +VTE and that allows us to further + + + align:start position:0% +VTE and that allows us to further +simplify this um we'll simplify it in + + align:start position:0% +simplify this um we'll simplify it in + + + align:start position:0% +simplify this um we'll simplify it in +two ways the first one is that from the + + align:start position:0% +two ways the first one is that from the + + + align:start position:0% +two ways the first one is that from the +point of view of the + + align:start position:0% +point of view of the + + + align:start position:0% +point of view of the +electrons the ions sorry the neutrals + + align:start position:0% +electrons the ions sorry the neutrals + + + align:start position:0% +electrons the ions sorry the neutrals +are basically not moving so we can set + + align:start position:0% +are basically not moving so we can set + + + align:start position:0% +are basically not moving so we can set +this to zero uh and from the point of + + align:start position:0% +this to zero uh and from the point of + + + align:start position:0% +this to zero uh and from the point of +view of the neutrals uh this VI is + + align:start position:0% +view of the neutrals uh this VI is + + + align:start position:0% +view of the neutrals uh this VI is +approximately constant it's a small + + align:start position:0% +approximately constant it's a small + + + align:start position:0% +approximately constant it's a small +value and it's approximately constant + + align:start position:0% +value and it's approximately constant + + + align:start position:0% +value and it's approximately constant +and so we can just take this VI out + + align:start position:0% +and so we can just take this VI out + + + align:start position:0% +and so we can just take this VI out +sorry we can evaluate + + align:start position:0% +sorry we can evaluate + + + align:start position:0% +sorry we can evaluate +this VI is just being VA and we can take + + align:start position:0% +this VI is just being VA and we can take + + + align:start position:0% +this VI is just being VA and we can take +it + + align:start position:0% + + + + align:start position:0% + +outside where it will nicely cancel with + + align:start position:0% +outside where it will nicely cancel with + + + align:start position:0% +outside where it will nicely cancel with +this VA so this gives us an expression + + align:start position:0% +this VA so this gives us an expression + + + align:start position:0% +this VA so this gives us an expression +that looks like one upon + + align:start position:0% +that looks like one upon + + + align:start position:0% +that looks like one upon +VA Sigma + + align:start position:0% +VA Sigma + + + align:start position:0% +VA Sigma +e v + + align:start position:0% +e v + + + align:start position:0% +e v +evaluated for effectiv the zero neutral + + align:start position:0% +evaluated for effectiv the zero neutral + + + align:start position:0% +evaluated for effectiv the zero neutral +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +any + + align:start position:0% +any + + + align:start position:0% +any +plus just these two cross-section Sigma + + align:start position:0% +plus just these two cross-section Sigma + + + align:start position:0% +plus just these two cross-section Sigma +p and sigma c times + + align:start position:0% +p and sigma c times + + + align:start position:0% +p and sigma c times +ni and we see that this term goes as one + + align:start position:0% +ni and we see that this term goes as one + + + align:start position:0% +ni and we see that this term goes as one +upon VA and this term doesn't so if + + align:start position:0% +upon VA and this term doesn't so if + + + align:start position:0% +upon VA and this term doesn't so if +we're dealing with energetic enough uh + + align:start position:0% +we're dealing with energetic enough uh + + + align:start position:0% +we're dealing with energetic enough uh +neutrals coming out of the core then we + + align:start position:0% +neutrals coming out of the core then we + + + align:start position:0% +neutrals coming out of the core then we +could imagine that this term could be + + align:start position:0% +could imagine that this term could be + + + align:start position:0% +could imagine that this term could be +relatively small it will depend exactly + + align:start position:0% +relatively small it will depend exactly + + + align:start position:0% +relatively small it will depend exactly +on Sigma e Sigma p and sigma C are but + + align:start position:0% +on Sigma e Sigma p and sigma C are but + + + align:start position:0% +on Sigma e Sigma p and sigma C are but +we can imagine for reasonable values + + align:start position:0% +we can imagine for reasonable values + + + align:start position:0% +we can imagine for reasonable values +this term will cancel so we end up with + + align:start position:0% +this term will cancel so we end up with + + + align:start position:0% +this term will cancel so we end up with +an expression that just has this so This + + align:start position:0% +an expression that just has this so This + + + align:start position:0% +an expression that just has this so This +Again is just + + align:start position:0% +Again is just + + + align:start position:0% +Again is just +roughly + + align:start position:0% +roughly + + + align:start position:0% +roughly +Alpha neglecting this for + + align:start position:0% + + + + align:start position:0% + +large + + align:start position:0% + + + + align:start position:0% + +okay so then you can put this back up + + align:start position:0% +okay so then you can put this back up + + + align:start position:0% +okay so then you can put this back up +into our probability of the particle + + align:start position:0% +into our probability of the particle + + + align:start position:0% +into our probability of the particle +getting through and we just get + + align:start position:0% +getting through and we just get + + + align:start position:0% +getting through and we just get +exponential of + + align:start position:0% +exponential of + + + align:start position:0% +exponential of +minus Sigma P plus Sigma + + align:start position:0% +minus Sigma P plus Sigma + + + align:start position:0% +minus Sigma P plus Sigma +C integral of Ni D like + + align:start position:0% +C integral of Ni D like + + + align:start position:0% +C integral of Ni D like +this and you can go into Hutchinson's + + align:start position:0% +this and you can go into Hutchinson's + + + align:start position:0% +this and you can go into Hutchinson's +book and see graphs of Sigma p and sigma + + align:start position:0% +book and see graphs of Sigma p and sigma + + + align:start position:0% +book and see graphs of Sigma p and sigma +C and and e as well for different plasma + + align:start position:0% +C and and e as well for different plasma + + + align:start position:0% +C and and e as well for different plasma +conditions and so if we just use an + + align:start position:0% +conditions and so if we just use an + + + align:start position:0% +conditions and so if we just use an +example that maybe we have 10 + + align:start position:0% +example that maybe we have 10 + + + align:start position:0% +example that maybe we have 10 +KV neutrals streaming out of the core + + align:start position:0% +KV neutrals streaming out of the core + + + align:start position:0% +KV neutrals streaming out of the core +because that's the sort of temperature + + align:start position:0% +because that's the sort of temperature + + + align:start position:0% +because that's the sort of temperature +we'd like in a fusion reactor so 10 KV + + align:start position:0% +we'd like in a fusion reactor so 10 KV + + + align:start position:0% +we'd like in a fusion reactor so 10 KV +neutrals we got a + + align:start position:0% +neutrals we got a + + + align:start position:0% +neutrals we got a +density of + + align:start position:0% +density of + + + align:start position:0% +density of +around + + align:start position:0% +around + + + align:start position:0% +around +10 20 per meter cubed so this is on the + + align:start position:0% +10 20 per meter cubed so this is on the + + + align:start position:0% +10 20 per meter cubed so this is on the +dense side for an mcf reactor but that's + + align:start position:0% +dense side for an mcf reactor but that's + + + align:start position:0% +dense side for an mcf reactor but that's +the sort of density we might need to + + align:start position:0% +the sort of density we might need to + + + align:start position:0% +the sort of density we might need to +react to relevant conditions then using + + align:start position:0% +react to relevant conditions then using + + + align:start position:0% +react to relevant conditions then using +this we will get a length scale in this + + align:start position:0% +this we will get a length scale in this + + + align:start position:0% +this we will get a length scale in this +exponent uh which is effectively the + + align:start position:0% +exponent uh which is effectively the + + + align:start position:0% +exponent uh which is effectively the +mean-free path the neutrals trying to + + align:start position:0% +mean-free path the neutrals trying to + + + align:start position:0% +mean-free path the neutrals trying to +leave the plasma and that is going to be + + align:start position:0% +leave the plasma and that is going to be + + + align:start position:0% +leave the plasma and that is going to be +about 10 + + align:start position:0% +about 10 + + + align:start position:0% +about 10 +cm so for this relatively hot relatively + + align:start position:0% +cm so for this relatively hot relatively + + + align:start position:0% +cm so for this relatively hot relatively +dense plasma we're not going to see very + + align:start position:0% +dense plasma we're not going to see very + + + align:start position:0% +dense plasma we're not going to see very +many neutrals more than 10 centimeters + + align:start position:0% +many neutrals more than 10 centimeters + + + align:start position:0% +many neutrals more than 10 centimeters +away from the core and probably our + + align:start position:0% +away from the core and probably our + + + align:start position:0% +away from the core and probably our +reactor is going to have a + + align:start position:0% +reactor is going to have a + + + align:start position:0% +reactor is going to have a +diameter a of about 100 cm or so so + + align:start position:0% +diameter a of about 100 cm or so so + + + align:start position:0% +diameter a of about 100 cm or so so +we're not going to see very many of + + align:start position:0% +we're not going to see very many of + + + align:start position:0% +we're not going to see very many of +these particles which means that in + + align:start position:0% +these particles which means that in + + + align:start position:0% +these particles which means that in +order for these neutral Diagnostics to + + align:start position:0% +order for these neutral Diagnostics to + + + align:start position:0% +order for these neutral Diagnostics to +work at all we're going to + + align:start position:0% +work at all we're going to + + + align:start position:0% +work at all we're going to +require that the + + align:start position:0% +require that the + + + align:start position:0% +require that the +line + + align:start position:0% +line + + + align:start position:0% +line +just + + align:start position:0% + + + + align:start position:0% + +having okay thank you um so we're going + + align:start position:0% +having okay thank you um so we're going + + + align:start position:0% +having okay thank you um so we're going +to require that the line + + align:start position:0% +to require that the line + + + align:start position:0% +to require that the line +integrated density here is going to be + + align:start position:0% +integrated density here is going to be + + + align:start position:0% +integrated density here is going to be +less than about 10 to the + + align:start position:0% +less than about 10 to the + + + align:start position:0% +less than about 10 to the +19 per meter squar here and if you do + + align:start position:0% +19 per meter squar here and if you do + + + align:start position:0% +19 per meter squar here and if you do +that then you get Lambda a more like a + + align:start position:0% +that then you get Lambda a more like a + + + align:start position:0% +that then you get Lambda a more like a +meter or + + align:start position:0% +meter or + + + align:start position:0% +meter or +so so we need low + + align:start position:0% +so so we need low + + + align:start position:0% +so so we need low +density I put it in quote marks because + + align:start position:0% +density I put it in quote marks because + + + align:start position:0% +density I put it in quote marks because +low means different things for different + + align:start position:0% +low means different things for different + + + align:start position:0% +low means different things for different +people but we need a relatively low + + align:start position:0% +people but we need a relatively low + + + align:start position:0% +people but we need a relatively low +density toac or magnetic confir Fusion + + align:start position:0% +density toac or magnetic confir Fusion + + + align:start position:0% +density toac or magnetic confir Fusion +device in order to get neutrals escaping + + align:start position:0% + + + + align:start position:0% + +core + + align:start position:0% + + + + align:start position:0% + +okay questions on + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +yes this is just like a a speed of the + + align:start position:0% +yes this is just like a a speed of the + + + align:start position:0% +yes this is just like a a speed of the +neutrals coming out here I realize + + align:start position:0% +neutrals coming out here I realize + + + align:start position:0% +neutrals coming out here I realize +actually drawing this I don't think this + + align:start position:0% +actually drawing this I don't think this + + + align:start position:0% +actually drawing this I don't think this +is right at all I don't think this is a + + align:start position:0% +is right at all I don't think this is a + + + align:start position:0% +is right at all I don't think this is a +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +function because we're talking about a + + align:start position:0% +function because we're talking about a + + + align:start position:0% +function because we're talking about a +distribution that's the whole thing + + align:start position:0% +distribution that's the whole thing + + + align:start position:0% +distribution that's the whole thing +we're trying to measure here so I think + + align:start position:0% +we're trying to measure here so I think + + + align:start position:0% +we're trying to measure here so I think +that actually I should be drawing it + + align:start position:0% +that actually I should be drawing it + + + align:start position:0% +that actually I should be drawing it +like this and call it f of a so this is + + align:start position:0% +like this and call it f of a so this is + + + align:start position:0% +like this and call it f of a so this is +the distribution the neutrals it's + + align:start position:0% +the distribution the neutrals it's + + + align:start position:0% +the distribution the neutrals it's +something Max wanish um but the average + + align:start position:0% +something Max wanish um but the average + + + align:start position:0% +something Max wanish um but the average +velocity here which I could call + + align:start position:0% +velocity here which I could call + + + align:start position:0% +velocity here which I could call +VTA which is maybe here is much larger + + align:start position:0% +VTA which is maybe here is much larger + + + align:start position:0% +VTA which is maybe here is much larger +than + + align:start position:0% +than + + + align:start position:0% +than +vti but much smaller + + align:start position:0% +vti but much smaller + + + align:start position:0% +vti but much smaller +than + + align:start position:0% +than + + + align:start position:0% +than +VTE so this is just the idea that um for + + align:start position:0% +VTE so this is just the idea that um for + + + align:start position:0% +VTE so this is just the idea that um for +these neutrals here uh from the point of + + align:start position:0% +these neutrals here uh from the point of + + + align:start position:0% +these neutrals here uh from the point of +view of the neutrals the I are basically + + align:start position:0% +view of the neutrals the I are basically + + + align:start position:0% +view of the neutrals the I are basically +stationary and from the point of view of + + align:start position:0% +stationary and from the point of view of + + + align:start position:0% +stationary and from the point of view of +the electrons the neutrals are basically + + align:start position:0% +the electrons the neutrals are basically + + + align:start position:0% +the electrons the neutrals are basically +stationary as well and that allows us to + + align:start position:0% +stationary as well and that allows us to + + + align:start position:0% +stationary as well and that allows us to +simplify all of these angle brackets + + align:start position:0% +simplify all of these angle brackets + + + align:start position:0% +simplify all of these angle brackets +which are actually averaging over the + + align:start position:0% +which are actually averaging over the + + + align:start position:0% +which are actually averaging over the +difference between the two velocity + + align:start position:0% +difference between the two velocity + + + align:start position:0% +difference between the two velocity +distributions we can either set it to + + align:start position:0% +distributions we can either set it to + + + align:start position:0% +distributions we can either set it to +zero or just be the velocity of the + + align:start position:0% +zero or just be the velocity of the + + + align:start position:0% +zero or just be the velocity of the +neutrals + + align:start position:0% + + + + align:start position:0% + +yeah yeah well we imagine there's some + + align:start position:0% +yeah yeah well we imagine there's some + + + align:start position:0% +yeah yeah well we imagine there's some +temperature distribution inside this so + + align:start position:0% +temperature distribution inside this so + + + align:start position:0% +temperature distribution inside this so +we're talking about these these neutrals + + align:start position:0% +we're talking about these these neutrals + + + align:start position:0% +we're talking about these these neutrals +here are neutral that are in the core of + + align:start position:0% +here are neutral that are in the core of + + + align:start position:0% +here are neutral that are in the core of +the plasma so we hope they're hotter + + align:start position:0% +the plasma so we hope they're hotter + + + align:start position:0% +the plasma so we hope they're hotter +than the neutral than the ions in the + + align:start position:0% +than the neutral than the ions in the + + + align:start position:0% +than the neutral than the ions in the +rest of + + align:start position:0% + + + + align:start position:0% + +plas no these are like the ions out here + + align:start position:0% +plas no these are like the ions out here + + + align:start position:0% +plas no these are like the ions out here +or something like that further out yeah + + align:start position:0% +or something like that further out yeah + + + align:start position:0% +or something like that further out yeah +that's a good question so if we have a + + align:start position:0% +that's a good question so if we have a + + + align:start position:0% +that's a good question so if we have a +sort of radius and temperature type + + align:start position:0% +sort of radius and temperature type + + + align:start position:0% +sort of radius and temperature type +thing we assume for a good reactor that + + align:start position:0% +thing we assume for a good reactor that + + + align:start position:0% +thing we assume for a good reactor that +it's peaked in some way and so we're + + align:start position:0% +it's peaked in some way and so we're + + + align:start position:0% +it's peaked in some way and so we're +asking about this the F of I VI I at R + + align:start position:0% +asking about this the F of I VI I at R + + + align:start position:0% +asking about this the F of I VI I at R +equals zero + + align:start position:0% +equals zero + + + align:start position:0% +equals zero +becomes our F of neutrals V + + align:start position:0% +becomes our F of neutrals V + + + align:start position:0% +becomes our F of neutrals V +neutral at r equal Z but they're + + align:start position:0% +neutral at r equal Z but they're + + + align:start position:0% +neutral at r equal Z but they're +streaming through + + align:start position:0% +streaming through + + + align:start position:0% +streaming through +some f ofi VI I at R greater than zero + + align:start position:0% +some f ofi VI I at R greater than zero + + + align:start position:0% +some f ofi VI I at R greater than zero +which in general is going to be a lower + + align:start position:0% +which in general is going to be a lower + + + align:start position:0% +which in general is going to be a lower +temperature so the distribution is + + align:start position:0% +temperature so the distribution is + + + align:start position:0% +temperature so the distribution is +smaller yeah you know all of this is + + align:start position:0% +smaller yeah you know all of this is + + + align:start position:0% +smaller yeah you know all of this is +very handwavy of course if you want to + + align:start position:0% +very handwavy of course if you want to + + + align:start position:0% +very handwavy of course if you want to +do this properly you have to keep track + + align:start position:0% +do this properly you have to keep track + + + align:start position:0% +do this properly you have to keep track +and all these integrals correctly but + + align:start position:0% +and all these integrals correctly but + + + align:start position:0% +and all these integrals correctly but +just to give an idea of the the the most + + align:start position:0% +just to give an idea of the the the most + + + align:start position:0% +just to give an idea of the the the most +important effect it turns out are the + + align:start position:0% +important effect it turns out are the + + + align:start position:0% +important effect it turns out are the +ion ion impact ionization and the charge + + align:start position:0% +ion ion impact ionization and the charge + + + align:start position:0% +ion ion impact ionization and the charge +exchange and the charge exchange + + align:start position:0% +exchange and the charge exchange + + + align:start position:0% +exchange and the charge exchange +dominates this pretty strongly actually + + align:start position:0% +dominates this pretty strongly actually + + + align:start position:0% +dominates this pretty strongly actually +mostly just Char exchange with some of + + align:start position:0% +mostly just Char exchange with some of + + + align:start position:0% +mostly just Char exchange with some of +the other + + align:start position:0% + + + + align:start position:0% + +yeah we haven't talked about that no no + + align:start position:0% +yeah we haven't talked about that no no + + + align:start position:0% +yeah we haven't talked about that no no +so what I'm saying is Imagine somehow + + align:start position:0% +so what I'm saying is Imagine somehow + + + align:start position:0% +so what I'm saying is Imagine somehow +you have created neutrals in core would + + align:start position:0% +you have created neutrals in core would + + + align:start position:0% +you have created neutrals in core would +they actually be able to get out because + + align:start position:0% +they actually be able to get out because + + + align:start position:0% +they actually be able to get out because +if they can't get out there's no point + + align:start position:0% +if they can't get out there's no point + + + align:start position:0% +if they can't get out there's no point +even trying to create them in the first + + align:start position:0% +even trying to create them in the first + + + align:start position:0% +even trying to create them in the first +place so we're sort of working our way + + align:start position:0% +place so we're sort of working our way + + + align:start position:0% +place so we're sort of working our way +backwards through the problem the next + + align:start position:0% +backwards through the problem the next + + + align:start position:0% +backwards through the problem the next +step is okay now that we know if we + + align:start position:0% +step is okay now that we know if we + + + align:start position:0% +step is okay now that we know if we +create some neutrals they can escape we + + align:start position:0% +create some neutrals they can escape we + + + align:start position:0% +create some neutrals they can escape we +can probably measure them in some way + + align:start position:0% +can probably measure them in some way + + + align:start position:0% +can probably measure them in some way +and learn about the core ion + + align:start position:0% +and learn about the core ion + + + align:start position:0% +and learn about the core ion +distribution now that we know that + + align:start position:0% +distribution now that we know that + + + align:start position:0% +distribution now that we know that +that's the case can we now work out how + + align:start position:0% +that's the case can we now work out how + + + align:start position:0% +that's the case can we now work out how +to create the neutrals and we'll talk + + align:start position:0% +to create the neutrals and we'll talk + + + align:start position:0% +to create the neutrals and we'll talk +about some techniques for that yeah + + align:start position:0% + + + + align:start position:0% + +yeah yeah I mean this is very crude + + align:start position:0% +yeah yeah I mean this is very crude + + + align:start position:0% +yeah yeah I mean this is very crude +you're quite right I mean this should be + + align:start position:0% +you're quite right I mean this should be + + + align:start position:0% +you're quite right I mean this should be +inside here but if we assume these don't + + align:start position:0% +inside here but if we assume these don't + + + align:start position:0% +inside here but if we assume these don't +vary too much as the particle travels + + align:start position:0% +vary too much as the particle travels + + + align:start position:0% +vary too much as the particle travels +from the core to the edge then it allows + + align:start position:0% +from the core to the edge then it allows + + + align:start position:0% +from the core to the edge then it allows +us just to pull out this factor of nidl + + align:start position:0% +us just to pull out this factor of nidl + + + align:start position:0% +us just to pull out this factor of nidl +and make it clear that it's like the + + align:start position:0% +and make it clear that it's like the + + + align:start position:0% +and make it clear that it's like the +line integrated density that's important + + align:start position:0% +line integrated density that's important + + + align:start position:0% +line integrated density that's important +thing in reality it would have to stay + + align:start position:0% +thing in reality it would have to stay + + + align:start position:0% +thing in reality it would have to stay +inside you say + + align:start position:0% + + + + align:start position:0% + +yeah any questions + + align:start position:0% + + + + align:start position:0% + +online all right let's go find out how + + align:start position:0% +online all right let's go find out how + + + align:start position:0% +online all right let's go find out how +to put some neutrals in the + + align:start position:0% + + + + align:start position:0% + +core + + align:start position:0% + + + + align:start position:0% + +trying to spell neutrals with an a + + align:start position:0% + + + + align:start position:0% + +there okay so again let's have some flux + + align:start position:0% +there okay so again let's have some flux + + + align:start position:0% +there okay so again let's have some flux +surfaces some plasma like this so one of + + align:start position:0% +surfaces some plasma like this so one of + + + align:start position:0% +surfaces some plasma like this so one of +the ways the neutrals could get there as + + align:start position:0% +the ways the neutrals could get there as + + + align:start position:0% +the ways the neutrals could get there as +we discussed before is from The Edge so + + align:start position:0% +we discussed before is from The Edge so + + + align:start position:0% +we discussed before is from The Edge so +around the edge of plasma there's um for + + align:start position:0% +around the edge of plasma there's um for + + + align:start position:0% +around the edge of plasma there's um for +example the scrape off layer and then + + align:start position:0% +example the scrape off layer and then + + + align:start position:0% +example the scrape off layer and then +there's going to be a region which is in + + align:start position:0% +there's going to be a region which is in + + + align:start position:0% +there's going to be a region which is in +contact with the wall which is + + align:start position:0% +contact with the wall which is + + + align:start position:0% +contact with the wall which is +relatively cold and so we can have + + align:start position:0% +relatively cold and so we can have + + + align:start position:0% +relatively cold and so we can have +neutrals uh being produced here and + + align:start position:0% +neutrals uh being produced here and + + + align:start position:0% +neutrals uh being produced here and +these neutrals will wander in and they + + align:start position:0% +these neutrals will wander in and they + + + align:start position:0% +these neutrals will wander in and they +won't see the magnetic field lines and + + align:start position:0% +won't see the magnetic field lines and + + + align:start position:0% +won't see the magnetic field lines and +so maybe one of them will only get so + + align:start position:0% +so maybe one of them will only get so + + + align:start position:0% +so maybe one of them will only get so +far here before the charge exchanges and + + align:start position:0% +far here before the charge exchanges and + + + align:start position:0% +far here before the charge exchanges and +this one will get a little bit further + + align:start position:0% +this one will get a little bit further + + + align:start position:0% +this one will get a little bit further +but you can imagine that maybe a couple + + align:start position:0% +but you can imagine that maybe a couple + + + align:start position:0% +but you can imagine that maybe a couple +of these neutrals wander into the center + + align:start position:0% +of these neutrals wander into the center + + + align:start position:0% +of these neutrals wander into the center +they charge exchange and then we can + + align:start position:0% +they charge exchange and then we can + + + align:start position:0% +they charge exchange and then we can +start getting + + align:start position:0% +start getting + + + align:start position:0% +start getting +those the new neutrals the ones that + + align:start position:0% +those the new neutrals the ones that + + + align:start position:0% +those the new neutrals the ones that +represent the core ions start moving + + align:start position:0% +represent the core ions start moving + + + align:start position:0% +represent the core ions start moving +back out + + align:start position:0% + + + + align:start position:0% + +again so one possibility is we'll call + + align:start position:0% +again so one possibility is we'll call + + + align:start position:0% +again so one possibility is we'll call +it Edge + + align:start position:0% + + + + align:start position:0% + +fueling and we know how to calculate the + + align:start position:0% +fueling and we know how to calculate the + + + align:start position:0% +fueling and we know how to calculate the +probability of that because we just + + align:start position:0% +probability of that because we just + + + align:start position:0% +probability of that because we just +spent a long time trying to calculate + + align:start position:0% +spent a long time trying to calculate + + + align:start position:0% +spent a long time trying to calculate +the probability of the opposite process + + align:start position:0% +the probability of the opposite process + + + align:start position:0% +the probability of the opposite process +so now we know that it's basically p b + + align:start position:0% +so now we know that it's basically p b + + + align:start position:0% +so now we know that it's basically p b +a which is the probability of going from + + align:start position:0% +a which is the probability of going from + + + align:start position:0% +a which is the probability of going from +the outside B into the core which we + + align:start position:0% +the outside B into the core which we + + + align:start position:0% +the outside B into the core which we +called a in our previous diagram so we + + align:start position:0% +called a in our previous diagram so we + + + align:start position:0% +called a in our previous diagram so we +can estimate How likely it is that any + + align:start position:0% +can estimate How likely it is that any + + + align:start position:0% +can estimate How likely it is that any +of these particles get through and the + + align:start position:0% +of these particles get through and the + + + align:start position:0% +of these particles get through and the +answer is that this actually does create + + align:start position:0% +answer is that this actually does create + + + align:start position:0% +answer is that this actually does create +a fair amount of neutrals in the core + + align:start position:0% +a fair amount of neutrals in the core + + + align:start position:0% +a fair amount of neutrals in the core +just because there are so many neutrals + + align:start position:0% +just because there are so many neutrals + + + align:start position:0% +just because there are so many neutrals +in the edge some of them will get + + align:start position:0% +in the edge some of them will get + + + align:start position:0% +in the edge some of them will get +through so this technique by itself will + + align:start position:0% +through so this technique by itself will + + + align:start position:0% +through so this technique by itself will +create a detectable flux of core + + align:start position:0% +create a detectable flux of core + + + align:start position:0% +create a detectable flux of core +neutrals coming back out again okay so + + align:start position:0% +neutrals coming back out again okay so + + + align:start position:0% +neutrals coming back out again okay so +PBA which is Edge decor + + align:start position:0% + + + + align:start position:0% + +another thing you might say well trapped + + align:start position:0% +another thing you might say well trapped + + + align:start position:0% +another thing you might say well trapped +just by some Atomic processes in the + + align:start position:0% +just by some Atomic processes in the + + + align:start position:0% +just by some Atomic processes in the +core here we could get neutrals + + align:start position:0% +core here we could get neutrals + + + align:start position:0% +core here we could get neutrals +developing here so we could have + + align:start position:0% +developing here so we could have + + + align:start position:0% +developing here so we could have +radiative + + align:start position:0% + + + + align:start position:0% + +recombination because after all there's + + align:start position:0% +recombination because after all there's + + + align:start position:0% +recombination because after all there's +a load of electrons flying + + align:start position:0% + + + + align:start position:0% + +around + + align:start position:0% +around + + + align:start position:0% +around +these electrons are up above the + + align:start position:0% +these electrons are up above the + + + align:start position:0% +these electrons are up above the +ionization energy so they're + + align:start position:0% +ionization energy so they're + + + align:start position:0% +ionization energy so they're +free but this electron could be caught + + align:start position:0% +free but this electron could be caught + + + align:start position:0% +free but this electron could be caught +by the electric potential of the ion and + + align:start position:0% +by the electric potential of the ion and + + + align:start position:0% +by the electric potential of the ion and +become a bound electron and then we + + align:start position:0% +become a bound electron and then we + + + align:start position:0% +become a bound electron and then we +would get out our recombination + + align:start position:0% +would get out our recombination + + + align:start position:0% +would get out our recombination +Photon that process could happen but of + + align:start position:0% +Photon that process could happen but of + + + align:start position:0% +Photon that process could happen but of +course the other process we've already + + align:start position:0% +course the other process we've already + + + align:start position:0% +course the other process we've already +discussed is when we have an electron + + align:start position:0% +discussed is when we have an electron + + + align:start position:0% +discussed is when we have an electron +come in and collide with one of the + + align:start position:0% +come in and collide with one of the + + + align:start position:0% +come in and collide with one of the +inner shell electrons and we end up with + + align:start position:0% +inner shell electrons and we end up with + + + align:start position:0% +inner shell electrons and we end up with +two electrons coming back out again this + + align:start position:0% +two electrons coming back out again this + + + align:start position:0% +two electrons coming back out again this +is electron + + align:start position:0% +is electron + + + align:start position:0% +is electron +impact + + align:start position:0% +impact + + + align:start position:0% +impact +ionization um + + align:start position:0% +ionization um + + + align:start position:0% +ionization um +and there'll be a balance in steady + + align:start position:0% +and there'll be a balance in steady + + + align:start position:0% +and there'll be a balance in steady +States between these two processes and + + align:start position:0% +States between these two processes and + + + align:start position:0% +States between these two processes and +that balance will look like the density + + align:start position:0% +that balance will look like the density + + + align:start position:0% +that balance will look like the density +of electrons the density of ions uh the + + align:start position:0% +of electrons the density of ions uh the + + + align:start position:0% +of electrons the density of ions uh the +reactivity or the cross-section for the + + align:start position:0% +reactivity or the cross-section for the + + + align:start position:0% +reactivity or the cross-section for the +radiative rec + + align:start position:0% +radiative rec + + + align:start position:0% +radiative rec +combination Times by the electron + + align:start position:0% +combination Times by the electron + + + align:start position:0% +combination Times by the electron +velocity and that will be balanced by + + align:start position:0% +velocity and that will be balanced by + + + align:start position:0% +velocity and that will be balanced by +the electron density the density of + + align:start position:0% +the electron density the density of + + + align:start position:0% +the electron density the density of +neutrals + + align:start position:0% +neutrals + + + align:start position:0% +neutrals +here Sigma e for electron impact + + align:start position:0% +here Sigma e for electron impact + + + align:start position:0% +here Sigma e for electron impact +ionization de like that so that means + + align:start position:0% +ionization de like that so that means + + + align:start position:0% +ionization de like that so that means +that we can look at this and go okay + + align:start position:0% +that we can look at this and go okay + + + align:start position:0% +that we can look at this and go okay +what is the steady state density of + + align:start position:0% +what is the steady state density of + + + align:start position:0% +what is the steady state density of +neutrals that's going to be n over ni I + + align:start position:0% +neutrals that's going to be n over ni I + + + align:start position:0% +neutrals that's going to be n over ni I +the ne's cancel so it's just going to be + + align:start position:0% +the ne's cancel so it's just going to be + + + align:start position:0% +the ne's cancel so it's just going to be +the ratio of these reactivities Sigma r + + align:start position:0% +the ratio of these reactivities Sigma r + + + align:start position:0% +the ratio of these reactivities Sigma r +v over Sigma e e e like + + align:start position:0% +v over Sigma e e e like + + + align:start position:0% +v over Sigma e e e like +that and at 1 + + align:start position:0% +that and at 1 + + + align:start position:0% +that and at 1 +KV which is a reasonable temperature for + + align:start position:0% +KV which is a reasonable temperature for + + + align:start position:0% +KV which is a reasonable temperature for +you to have in your core um this is + + align:start position:0% +you to have in your core um this is + + + align:start position:0% +you to have in your core um this is +about 10 to the minus 8 so the point I'm + + align:start position:0% +about 10 to the minus 8 so the point I'm + + + align:start position:0% +about 10 to the minus 8 so the point I'm +trying to make here is although you + + align:start position:0% +trying to make here is although you + + + align:start position:0% +trying to make here is although you +might occasionally have some + + align:start position:0% +might occasionally have some + + + align:start position:0% +might occasionally have some +recombination process because the other + + align:start position:0% +recombination process because the other + + + align:start position:0% +recombination process because the other +processes which lead to ionization again + + align:start position:0% +processes which lead to ionization again + + + align:start position:0% +processes which lead to ionization again +are so rapid you quickly will reionize + + align:start position:0% +are so rapid you quickly will reionize + + + align:start position:0% +are so rapid you quickly will reionize +and so if you have 10 to 13 or 10 to 20 + + align:start position:0% +and so if you have 10 to 13 or 10 to 20 + + + align:start position:0% +and so if you have 10 to 13 or 10 to 20 +um + + align:start position:0% +um + + + align:start position:0% +um +ions per cubic meter they'll only have + + align:start position:0% +ions per cubic meter they'll only have + + + align:start position:0% +ions per cubic meter they'll only have +10 to 12 neutral and that's not really + + align:start position:0% +10 to 12 neutral and that's not really + + + align:start position:0% +10 to 12 neutral and that's not really +enough to detect so this is + + align:start position:0% + + + + align:start position:0% + +negligible so Edge fueling yes could be + + align:start position:0% +negligible so Edge fueling yes could be + + + align:start position:0% +negligible so Edge fueling yes could be +a way of getting neutrals in the core + + align:start position:0% +a way of getting neutrals in the core + + + align:start position:0% +a way of getting neutrals in the core +radiative recombination is not a way and + + align:start position:0% +radiative recombination is not a way and + + + align:start position:0% +radiative recombination is not a way and +you kind of know this because if this + + align:start position:0% +you kind of know this because if this + + + align:start position:0% +you kind of know this because if this +was an effective process then you would + + align:start position:0% +was an effective process then you would + + + align:start position:0% +was an effective process then you would +end up with a large neutral fraction in + + align:start position:0% +end up with a large neutral fraction in + + + align:start position:0% +end up with a large neutral fraction in +the cor of your toac and that's not + + align:start position:0% +the cor of your toac and that's not + + + align:start position:0% +the cor of your toac and that's not +something that we generally think about + + align:start position:0% +something that we generally think about + + + align:start position:0% +something that we generally think about +and doesn't generally happen Okay and + + align:start position:0% +and doesn't generally happen Okay and + + + align:start position:0% +and doesn't generally happen Okay and +then finally there are beans and I'll + + align:start position:0% +then finally there are beans and I'll + + + align:start position:0% +then finally there are beans and I'll +talk a little bit more about beam in a + + align:start position:0% +talk a little bit more about beam in a + + + align:start position:0% +talk a little bit more about beam in a +second as like an active version of the + + align:start position:0% +second as like an active version of the + + + align:start position:0% +second as like an active version of the +diagnostic but I just want to talk about + + align:start position:0% +diagnostic but I just want to talk about + + + align:start position:0% +diagnostic but I just want to talk about +how we actually + + align:start position:0% +how we actually + + + align:start position:0% +how we actually +measure these neutrals coming out in + + align:start position:0% +measure these neutrals coming out in + + + align:start position:0% +measure these neutrals coming out in +this passive version where we just let + + align:start position:0% +this passive version where we just let + + + align:start position:0% +this passive version where we just let +Edge fueling do the + + align:start position:0% + + + + align:start position:0% + +work + + align:start position:0% + + + + align:start position:0% + +so pass it + + align:start position:0% +so pass it + + + align:start position:0% +so pass it +CX with Edge + + align:start position:0% + + + + align:start position:0% + +neutrals so we've got + + align:start position:0% +neutrals so we've got + + + align:start position:0% +neutrals so we've got +some hocak vacuum chamber some mcf + + align:start position:0% +some hocak vacuum chamber some mcf + + + align:start position:0% +some hocak vacuum chamber some mcf +vacuum chamber with some plasma like + + align:start position:0% +vacuum chamber with some plasma like + + + align:start position:0% +vacuum chamber with some plasma like +this we have all of + + align:start position:0% +this we have all of + + + align:start position:0% +this we have all of +the particles coming in from the edge + + align:start position:0% +the particles coming in from the edge + + + align:start position:0% +the particles coming in from the edge +and then the charge exchanging with + + align:start position:0% +and then the charge exchanging with + + + align:start position:0% +and then the charge exchanging with +particles in the core and and they're + + align:start position:0% +particles in the core and and they're + + + align:start position:0% +particles in the core and and they're +producing for + + align:start position:0% + + + + align:start position:0% + +example a hydrogen neutral that's coming + + align:start position:0% +example a hydrogen neutral that's coming + + + align:start position:0% +example a hydrogen neutral that's coming +out from the core and we put that + + align:start position:0% +out from the core and we put that + + + align:start position:0% +out from the core and we put that +hydrogen neutral into something called a + + align:start position:0% +hydrogen neutral into something called a + + + align:start position:0% +hydrogen neutral into something called a +stripping + + align:start position:0% + + + + align:start position:0% + +cell and it comes out as a hydrogen ion + + align:start position:0% +cell and it comes out as a hydrogen ion + + + align:start position:0% +cell and it comes out as a hydrogen ion +again but a hydrogen ion with the same + + align:start position:0% +again but a hydrogen ion with the same + + + align:start position:0% +again but a hydrogen ion with the same +velocity or effectively the same + + align:start position:0% +velocity or effectively the same + + + align:start position:0% +velocity or effectively the same +distribution function as the neutral + + align:start position:0% +distribution function as the neutral + + + align:start position:0% +distribution function as the neutral +coming in the stripping cell has a very + + align:start position:0% +coming in the stripping cell has a very + + + align:start position:0% +coming in the stripping cell has a very +uh electropositive gas so it wants to + + align:start position:0% +uh electropositive gas so it wants to + + + align:start position:0% +uh electropositive gas so it wants to +take off the electrons and it will + + align:start position:0% +take off the electrons and it will + + + align:start position:0% +take off the electrons and it will +charge exchange about really changing + + align:start position:0% +charge exchange about really changing + + + align:start position:0% +charge exchange about really changing +the trajectory of this very much and + + align:start position:0% +the trajectory of this very much and + + + align:start position:0% +the trajectory of this very much and +then we have for example a large + + align:start position:0% +then we have for example a large + + + align:start position:0% +then we have for example a large +magnetic field in this region that bends + + align:start position:0% +magnetic field in this region that bends + + + align:start position:0% +magnetic field in this region that bends +the particles according to their + + align:start position:0% +the particles according to their + + + align:start position:0% +the particles according to their +velocity and then we have a detector + + align:start position:0% +velocity and then we have a detector + + + align:start position:0% +velocity and then we have a detector +like + + align:start position:0% +like + + + align:start position:0% +like +this with bins in it and the bins have + + align:start position:0% +this with bins in it and the bins have + + + align:start position:0% +this with bins in it and the bins have +different sensitivity to different + + align:start position:0% +different sensitivity to different + + + align:start position:0% +different sensitivity to different +velocities here and so by counting out + + align:start position:0% +velocities here and so by counting out + + + align:start position:0% +velocities here and so by counting out +the number of particles in each + + align:start position:0% +the number of particles in each + + + align:start position:0% +the number of particles in each +bin we get out that distribution + + align:start position:0% + + + + align:start position:0% + +function like + + align:start position:0% +function like + + + align:start position:0% +function like +that and we hope that during their + + align:start position:0% +that and we hope that during their + + + align:start position:0% +that and we hope that during their +travels from the core through our + + align:start position:0% +travels from the core through our + + + align:start position:0% +travels from the core through our +stripping cell onto our detector the + + align:start position:0% +stripping cell onto our detector the + + + align:start position:0% +stripping cell onto our detector the +distribution function has not been + + align:start position:0% +distribution function has not been + + + align:start position:0% +distribution function has not been +changed very much so we really are + + align:start position:0% +changed very much so we really are + + + align:start position:0% +changed very much so we really are +measuring the distribution function of + + align:start position:0% +measuring the distribution function of + + + align:start position:0% +measuring the distribution function of +the particles in the center there so if + + align:start position:0% +the particles in the center there so if + + + align:start position:0% +the particles in the center there so if +we look at that on our detector and I + + align:start position:0% +we look at that on our detector and I + + + align:start position:0% +we look at that on our detector and I +plot it on a logarithmic scale the log + + align:start position:0% +plot it on a logarithmic scale the log + + + align:start position:0% +plot it on a logarithmic scale the log +of intensity which is equal to log of + + align:start position:0% +of intensity which is equal to log of + + + align:start position:0% +of intensity which is equal to log of +particle number + + align:start position:0% +particle number + + + align:start position:0% +particle number +versus particle energy here so not + + align:start position:0% +versus particle energy here so not + + + align:start position:0% +versus particle energy here so not +velocity but energy which is half mv^ + + align:start position:0% +velocity but energy which is half mv^ + + + align:start position:0% +velocity but energy which is half mv^ +s we see that we + + align:start position:0% +s we see that we + + + align:start position:0% +s we see that we +have a region that is approximately + + align:start position:0% +have a region that is approximately + + + align:start position:0% +have a region that is approximately +straight and that has a slope of one + + align:start position:0% +straight and that has a slope of one + + + align:start position:0% +straight and that has a slope of one +over TI because our distribution + + align:start position:0% +over TI because our distribution + + + align:start position:0% +over TI because our distribution +function from mellan is exponential of + + align:start position:0% +function from mellan is exponential of + + + align:start position:0% +function from mellan is exponential of +minus E over TI like that and then we + + align:start position:0% +minus E over TI like that and then we + + + align:start position:0% +minus E over TI like that and then we +might have some interesting features + + align:start position:0% +might have some interesting features + + + align:start position:0% +might have some interesting features +down at the bottom here where it become + + align:start position:0% +down at the bottom here where it become + + + align:start position:0% +down at the bottom here where it become +looks non- maxwelli and so this can be + + align:start position:0% +looks non- maxwelli and so this can be + + + align:start position:0% +looks non- maxwelli and so this can be +the pale and this will correspond to + + align:start position:0% +the pale and this will correspond to + + + align:start position:0% +the pale and this will correspond to +fast + + align:start position:0% + + + + align:start position:0% + +ions and measuring fast Downs is very + + align:start position:0% +ions and measuring fast Downs is very + + + align:start position:0% +ions and measuring fast Downs is very +important in magnetic confinement Fusion + + align:start position:0% +important in magnetic confinement Fusion + + + align:start position:0% +important in magnetic confinement Fusion +these fast ions might be due to things + + align:start position:0% +these fast ions might be due to things + + + align:start position:0% +these fast ions might be due to things +like RF + + align:start position:0% + + + + align:start position:0% + +heating or they might be due to runaways + + align:start position:0% +heating or they might be due to runaways + + + align:start position:0% +heating or they might be due to runaways +being produced by inductively driven + + align:start position:0% +being produced by inductively driven + + + align:start position:0% +being produced by inductively driven +electric fields or other cool physics so + + align:start position:0% +electric fields or other cool physics so + + + align:start position:0% +electric fields or other cool physics so +it's nice to be able to measure those + + align:start position:0% +it's nice to be able to measure those + + + align:start position:0% +it's nice to be able to measure those +fast ands as well the main problem with + + align:start position:0% +fast ands as well the main problem with + + + align:start position:0% +fast ands as well the main problem with +this technique of course is it's line + + align:start position:0% +this technique of course is it's line + + + align:start position:0% +this technique of course is it's line +integrated if I have my detector set up + + align:start position:0% +integrated if I have my detector set up + + + align:start position:0% +integrated if I have my detector set up +like this and collecting all the + + align:start position:0% +like this and collecting all the + + + align:start position:0% +like this and collecting all the +particles in this region that come down + + align:start position:0% + + + + align:start position:0% + +here and so you don't really know + + align:start position:0% +here and so you don't really know + + + align:start position:0% +here and so you don't really know +exactly where those particles have come + + align:start position:0% +exactly where those particles have come + + + align:start position:0% +exactly where those particles have come +from and so we have the same problem we + + align:start position:0% +from and so we have the same problem we + + + align:start position:0% +from and so we have the same problem we +have with all of our other line + + align:start position:0% +have with all of our other line + + + align:start position:0% +have with all of our other line +integrated + + align:start position:0% +integrated + + + align:start position:0% +integrated +Diagnostics but it's you know pretty + + align:start position:0% +Diagnostics but it's you know pretty + + + align:start position:0% +Diagnostics but it's you know pretty +free we don't actually have to put any + + align:start position:0% +free we don't actually have to put any + + + align:start position:0% +free we don't actually have to put any +effort into making neutrals in the + + align:start position:0% +effort into making neutrals in the + + + align:start position:0% +effort into making neutrals in the +center there we just let the fact that + + align:start position:0% +center there we just let the fact that + + + align:start position:0% +center there we just let the fact that +we have a crappy vacuum chamber do the + + align:start position:0% +we have a crappy vacuum chamber do the + + + align:start position:0% +we have a crappy vacuum chamber do the +work for so this is a nice way to do it + + align:start position:0% +work for so this is a nice way to do it + + + align:start position:0% +work for so this is a nice way to do it +if you don't have a neutral beam any + + align:start position:0% +if you don't have a neutral beam any + + + align:start position:0% +if you don't have a neutral beam any +questions on that before you put a + + align:start position:0% +questions on that before you put a + + + align:start position:0% +questions on that before you put a +neutral beam in system + + align:start position:0% + + + + align:start position:0% + +mhm oh you would just have a magnetic + + align:start position:0% +mhm oh you would just have a magnetic + + + align:start position:0% +mhm oh you would just have a magnetic +field + + align:start position:0% + + + + align:start position:0% + +yeah and frankly the magnetic field of + + align:start position:0% +yeah and frankly the magnetic field of + + + align:start position:0% +yeah and frankly the magnetic field of +your toac does a pretty good job of that + + align:start position:0% +your toac does a pretty good job of that + + + align:start position:0% +your toac does a pretty good job of that +yeah yes + + align:start position:0% + + + + align:start position:0% + +how does what depend + + align:start position:0% + + + + align:start position:0% + +like yeah uh I mean we tend to be + + align:start position:0% +like yeah uh I mean we tend to be + + + align:start position:0% +like yeah uh I mean we tend to be +thinking about we still tend to be + + align:start position:0% +thinking about we still tend to be + + + align:start position:0% +thinking about we still tend to be +thinking about these neutrals coming + + align:start position:0% +thinking about these neutrals coming + + + align:start position:0% +thinking about these neutrals coming +from the Ed as being hydrogen so when we + + align:start position:0% +from the Ed as being hydrogen so when we + + + align:start position:0% +from the Ed as being hydrogen so when we +have when we have the pl hydrogen plasma + + align:start position:0% +have when we have the pl hydrogen plasma + + + align:start position:0% +have when we have the pl hydrogen plasma +by hydrogen I mean duum and Trum are + + align:start position:0% +by hydrogen I mean duum and Trum are + + + align:start position:0% +by hydrogen I mean duum and Trum are +fuel so when we have our fuel in contact + + align:start position:0% +fuel so when we have our fuel in contact + + + align:start position:0% +fuel so when we have our fuel in contact +with the wall there will be a layer of + + align:start position:0% +with the wall there will be a layer of + + + align:start position:0% +with the wall there will be a layer of +like low ionization state partially + + align:start position:0% +like low ionization state partially + + + align:start position:0% +like low ionization state partially +neutral gas around the edge just gets + + align:start position:0% +neutral gas around the edge just gets + + + align:start position:0% +neutral gas around the edge just gets +into contact with a wall and so most of + + align:start position:0% +into contact with a wall and so most of + + + align:start position:0% +into contact with a wall and so most of +this will be coming from I don't know + + align:start position:0% +this will be coming from I don't know + + + align:start position:0% +this will be coming from I don't know +what happens if you start looking at + + align:start position:0% +what happens if you start looking at + + + align:start position:0% +what happens if you start looking at +this and you start looking at all the + + align:start position:0% +this and you start looking at all the + + + align:start position:0% +this and you start looking at all the +neutrals as well presuming you now need + + align:start position:0% +neutrals as well presuming you now need + + + align:start position:0% +neutrals as well presuming you now need +many more coefficients to calculate and + + align:start position:0% +many more coefficients to calculate and + + + align:start position:0% +many more coefficients to calculate and +probably if you're doing it properly you + + align:start position:0% +probably if you're doing it properly you + + + align:start position:0% +probably if you're doing it properly you +should take into account those but I + + align:start position:0% +should take into account those but I + + + align:start position:0% +should take into account those but I +think although impurities can dominate + + align:start position:0% +think although impurities can dominate + + + align:start position:0% +think although impurities can dominate +things like line radiation this really + + align:start position:0% +things like line radiation this really + + + align:start position:0% +things like line radiation this really +depends on the ion + + align:start position:0% +depends on the ion + + + align:start position:0% +depends on the ion +number so we're going to be thinking + + align:start position:0% +number so we're going to be thinking + + + align:start position:0% +number so we're going to be thinking +probably about the num the the the + + align:start position:0% +probably about the num the the the + + + align:start position:0% +probably about the num the the the +impurities probably don't have a higher + + align:start position:0% +impurities probably don't have a higher + + + align:start position:0% +impurities probably don't have a higher +number density in the fuel or you've + + align:start position:0% +number density in the fuel or you've + + + align:start position:0% +number density in the fuel or you've +done something very wrong that's happen + + align:start position:0% +done something very wrong that's happen + + + align:start position:0% +done something very wrong that's happen +so I think you're still going to be + + align:start position:0% +so I think you're still going to be + + + align:start position:0% +so I think you're still going to be +dominated by your fuel I + + align:start position:0% +dominated by your fuel I + + + align:start position:0% +dominated by your fuel I +yeah yes so if you start with a neutral + + align:start position:0% +yeah yes so if you start with a neutral + + + align:start position:0% +yeah yes so if you start with a neutral +at the and then it goes into the plasma + + align:start position:0% +at the and then it goes into the plasma + + + align:start position:0% +at the and then it goes into the plasma +4 Char exchange and the new neutral that + + align:start position:0% +4 Char exchange and the new neutral that + + + align:start position:0% +4 Char exchange and the new neutral that +leaks out was an + + align:start position:0% +leaks out was an + + + align:start position:0% +leaks out was an +IR and then you're measuring that Neal + + align:start position:0% +IR and then you're measuring that Neal + + + align:start position:0% +IR and then you're measuring that Neal +out how do you know that you're only + + align:start position:0% + + + + align:start position:0% + +measuring yeah so the question how do we + + align:start position:0% +measuring yeah so the question how do we + + + align:start position:0% +measuring yeah so the question how do we +know that none of our signal is due to + + align:start position:0% +know that none of our signal is due to + + + align:start position:0% +know that none of our signal is due to +the neutrals at the edge well the + + align:start position:0% +the neutrals at the edge well the + + + align:start position:0% +the neutrals at the edge well the +neutrals at the edge are very cold so + + align:start position:0% +neutrals at the edge are very cold so + + + align:start position:0% +neutrals at the edge are very cold so +their energy is very low so we probably + + align:start position:0% +their energy is very low so we probably + + + align:start position:0% +their energy is very low so we probably +will have a Spectra that looks like this + + align:start position:0% +will have a Spectra that looks like this + + + align:start position:0% +will have a Spectra that looks like this +or something with some noise up here or + + align:start position:0% +or something with some noise up here or + + + align:start position:0% +or something with some noise up here or +some some spous signal that's due to + + align:start position:0% +some some spous signal that's due to + + + align:start position:0% +some some spous signal that's due to +other neutrals in the system so I'll + + align:start position:0% +other neutrals in the system so I'll + + + align:start position:0% +other neutrals in the system so I'll +just start my fit at some nice high + + align:start position:0% +just start my fit at some nice high + + + align:start position:0% +just start my fit at some nice high +energy which can't be due to any of + + align:start position:0% +energy which can't be due to any of + + + align:start position:0% +energy which can't be due to any of +these uh cold ions or cold neutrals from + + align:start position:0% +these uh cold ions or cold neutrals from + + + align:start position:0% +these uh cold ions or cold neutrals from +The Edge has to just be due to the core + + align:start position:0% +The Edge has to just be due to the core + + + align:start position:0% +The Edge has to just be due to the core +ions + + align:start position:0% +ions + + + align:start position:0% +ions +instead okay any other + + align:start position:0% + + + + align:start position:0% + +yeah yeah so I mean that that's what's + + align:start position:0% +yeah yeah so I mean that that's what's + + + align:start position:0% +yeah yeah so I mean that that's what's +very challenging about this here because + + align:start position:0% +very challenging about this here because + + + align:start position:0% +very challenging about this here because +in fact this will be like the sum of a + + align:start position:0% +in fact this will be like the sum of a + + + align:start position:0% +in fact this will be like the sum of a +load of lines which will be weighted by + + align:start position:0% +load of lines which will be weighted by + + + align:start position:0% +load of lines which will be weighted by +their density so I think it is difficult + + align:start position:0% +their density so I think it is difficult + + + align:start position:0% +their density so I think it is difficult +to interpret the passive version of it + + align:start position:0% +to interpret the passive version of it + + + align:start position:0% +to interpret the passive version of it +of course if you go high enough out in + + align:start position:0% +of course if you go high enough out in + + + align:start position:0% +of course if you go high enough out in +energy and you can still fit a bit of a + + align:start position:0% +energy and you can still fit a bit of a + + + align:start position:0% +energy and you can still fit a bit of a +straight line you can be like there is + + align:start position:0% +straight line you can be like there is + + + align:start position:0% +straight line you can be like there is +some part of my plasma right because + + align:start position:0% +some part of my plasma right because + + + align:start position:0% +some part of my plasma right because +you'll have different + + align:start position:0% + + + + align:start position:0% + +slopes and there'll only be one slope + + align:start position:0% +slopes and there'll only be one slope + + + align:start position:0% +slopes and there'll only be one slope +that still extends all the way out here + + align:start position:0% +that still extends all the way out here + + + align:start position:0% +that still extends all the way out here +because each of these will eventually + + align:start position:0% +because each of these will eventually + + + align:start position:0% +because each of these will eventually +sort of drop off so if you're like aha + + align:start position:0% +sort of drop off so if you're like aha + + + align:start position:0% +sort of drop off so if you're like aha +still out here there's some region then + + align:start position:0% +still out here there's some region then + + + align:start position:0% +still out here there's some region then +that's probably your core ISS so you + + align:start position:0% +that's probably your core ISS so you + + + align:start position:0% +that's probably your core ISS so you +might have a chance of identifying but + + align:start position:0% +might have a chance of identifying but + + + align:start position:0% +might have a chance of identifying but +in general your signal look more comp + + align:start position:0% +in general your signal look more comp + + + align:start position:0% +in general your signal look more comp +which leads me very neatly onto using a + + align:start position:0% +which leads me very neatly onto using a + + + align:start position:0% +which leads me very neatly onto using a +neutral beam you do this + + align:start position:0% + + + + align:start position:0% + +instead so this actually is very similar + + align:start position:0% +instead so this actually is very similar + + + align:start position:0% +instead so this actually is very similar +to some of those active spectroscopy + + align:start position:0% +to some of those active spectroscopy + + + align:start position:0% +to some of those active spectroscopy +Diagnostics we talked about before we've + + align:start position:0% +Diagnostics we talked about before we've + + + align:start position:0% +Diagnostics we talked about before we've +again got our vacuum chamber under our + + align:start position:0% +again got our vacuum chamber under our + + + align:start position:0% +again got our vacuum chamber under our +plasma like this but now we have a + + align:start position:0% +plasma like this but now we have a + + + align:start position:0% +plasma like this but now we have a +neutral beam going through the + + align:start position:0% + + + + align:start position:0% + +plasma and if we have our detector + + align:start position:0% +plasma and if we have our detector + + + align:start position:0% +plasma and if we have our detector +oriented perpendicularly for + + align:start position:0% +oriented perpendicularly for + + + align:start position:0% +oriented perpendicularly for +this now we know that the majority of + + align:start position:0% +this now we know that the majority of + + + align:start position:0% +this now we know that the majority of +the neutrals are being born by charge + + align:start position:0% +the neutrals are being born by charge + + + align:start position:0% +the neutrals are being born by charge +exchange between the neutral beam and + + align:start position:0% +exchange between the neutral beam and + + + align:start position:0% +exchange between the neutral beam and +this small core region here which + + align:start position:0% +this small core region here which + + + align:start position:0% +this small core region here which +overlaps the field of view of our + + align:start position:0% +overlaps the field of view of our + + + align:start position:0% +overlaps the field of view of our +detector and the neutral beam + + align:start position:0% +detector and the neutral beam + + + align:start position:0% +detector and the neutral beam +here and so now we know very well when + + align:start position:0% +here and so now we know very well when + + + align:start position:0% +here and so now we know very well when +these particles come + + align:start position:0% +these particles come + + + align:start position:0% +these particles come +out that we are detecting F ofi VI are + + align:start position:0% +out that we are detecting F ofi VI are + + + align:start position:0% +out that we are detecting F ofi VI are +about + + align:start position:0% +about + + + align:start position:0% +about +zero from the core here so this allows + + align:start position:0% +zero from the core here so this allows + + + align:start position:0% +zero from the core here so this allows +us to actively Pro That central region + + align:start position:0% +us to actively Pro That central region + + + align:start position:0% +us to actively Pro That central region +here + + align:start position:0% + + + + align:start position:0% + +localizes + + align:start position:0% +localizes + + + align:start position:0% +localizes +um and this is often convenient because + + align:start position:0% +um and this is often convenient because + + + align:start position:0% +um and this is often convenient because +we often have neutral beams as we said + + align:start position:0% +we often have neutral beams as we said + + + align:start position:0% +we often have neutral beams as we said +these neutral beams are already being + + align:start position:0% +these neutral beams are already being + + + align:start position:0% +these neutral beams are already being +used for + + align:start position:0% +used for + + + align:start position:0% +used for +heating and + + align:start position:0% +heating and + + + align:start position:0% +heating and +for current + + align:start position:0% + + + + align:start position:0% + +Drive of course the neutral beam has the + + align:start position:0% +Drive of course the neutral beam has the + + + align:start position:0% +Drive of course the neutral beam has the +same problem uh that we found out when + + align:start position:0% +same problem uh that we found out when + + + align:start position:0% +same problem uh that we found out when +we were talking about how far these + + align:start position:0% +we were talking about how far these + + + align:start position:0% +we were talking about how far these +neutrals can penetrate if you have a + + align:start position:0% +neutrals can penetrate if you have a + + + align:start position:0% +neutrals can penetrate if you have a +density that's high enough inside your + + align:start position:0% +density that's high enough inside your + + + align:start position:0% +density that's high enough inside your +machine you're not going to be able to + + align:start position:0% +machine you're not going to be able to + + + align:start position:0% +machine you're not going to be able to +use a neutral beam to heat Al new + + align:start position:0% +use a neutral beam to heat Al new + + + align:start position:0% +use a neutral beam to heat Al new +current driv so beams tend to be limited + + align:start position:0% +current driv so beams tend to be limited + + + align:start position:0% +current driv so beams tend to be limited +to lower density machines which is why + + align:start position:0% +to lower density machines which is why + + + align:start position:0% +to lower density machines which is why +we've never had much use for them on + + align:start position:0% +we've never had much use for them on + + + align:start position:0% +we've never had much use for them on +devices like cod where the magnetic + + align:start position:0% +devices like cod where the magnetic + + + align:start position:0% +devices like cod where the magnetic +field in the density is very very high + + align:start position:0% +field in the density is very very high + + + align:start position:0% +field in the density is very very high +but for other devices you may well have + + align:start position:0% +but for other devices you may well have + + + align:start position:0% +but for other devices you may well have +a neutral beam already there so this is + + align:start position:0% +a neutral beam already there so this is + + + align:start position:0% +a neutral beam already there so this is +again kind of a freebie to have this as + + align:start position:0% +again kind of a freebie to have this as + + + align:start position:0% +again kind of a freebie to have this as +a + + align:start position:0% + + + + align:start position:0% + +diagnostic okay let's talk about some + + align:start position:0% +diagnostic okay let's talk about some + + + align:start position:0% +diagnostic okay let's talk about some +other things you can do with uh a + + align:start position:0% +other things you can do with uh a + + + align:start position:0% +other things you can do with uh a +neutral + + align:start position:0% + + + + align:start position:0% + +beam so there's a very nice technique + + align:start position:0% +beam so there's a very nice technique + + + align:start position:0% +beam so there's a very nice technique +which is + + align:start position:0% + + + + align:start position:0% + +called my green there we + + align:start position:0% +called my green there we + + + align:start position:0% +called my green there we +go + + align:start position:0% +go + + + align:start position:0% +go +charge + + align:start position:0% + + + + align:start position:0% + +exchange + + align:start position:0% + + + + align:start position:0% + +spectroscopy this technique has + + align:start position:0% +spectroscopy this technique has + + + align:start position:0% +spectroscopy this technique has +developed a number of acronyms in the + + align:start position:0% +developed a number of acronyms in the + + + align:start position:0% +developed a number of acronyms in the +literature which are all uh identical in + + align:start position:0% +literature which are all uh identical in + + + align:start position:0% +literature which are all uh identical in +meaning so some people call it charge + + align:start position:0% +meaning so some people call it charge + + + align:start position:0% +meaning so some people call it charge +exchange re com ation spectroscopy and + + align:start position:0% +exchange re com ation spectroscopy and + + + align:start position:0% +exchange re com ation spectroscopy and +some people call it charge exchange + + align:start position:0% +some people call it charge exchange + + + align:start position:0% +some people call it charge exchange +recombination spectroscopy so if you see + + align:start position:0% +recombination spectroscopy so if you see + + + align:start position:0% +recombination spectroscopy so if you see +an acronym that looks something like + + align:start position:0% +an acronym that looks something like + + + align:start position:0% +an acronym that looks something like +this they're probably talking about the + + align:start position:0% +this they're probably talking about the + + + align:start position:0% +this they're probably talking about the +same diagnostic these are not two + + align:start position:0% +same diagnostic these are not two + + + align:start position:0% +same diagnostic these are not two +separate Diagnostics they are the same + + align:start position:0% +separate Diagnostics they are the same + + + align:start position:0% +separate Diagnostics they are the same +thing here um so the idea of charge + + align:start position:0% +thing here um so the idea of charge + + + align:start position:0% +thing here um so the idea of charge +exchange recombination spectroscopy is + + align:start position:0% +exchange recombination spectroscopy is + + + align:start position:0% +exchange recombination spectroscopy is +within our + + align:start position:0% + + + + align:start position:0% + +plasma we will have some neutrals oh + + align:start position:0% +plasma we will have some neutrals oh + + + align:start position:0% +plasma we will have some neutrals oh +sorry we will have some ions which are + + align:start position:0% +sorry we will have some ions which are + + + align:start position:0% +sorry we will have some ions which are +impurity ions sorry so an impurity like + + align:start position:0% + + + + align:start position:0% + +a we'll just use a symbol a I'll make it + + align:start position:0% +a we'll just use a symbol a I'll make it + + + align:start position:0% +a we'll just use a symbol a I'll make it +clear what it is in a moment these + + align:start position:0% +clear what it is in a moment these + + + align:start position:0% +clear what it is in a moment these +impurities will things like oxygen or + + align:start position:0% +impurities will things like oxygen or + + + align:start position:0% +impurities will things like oxygen or +carbon or Boron and although these + + align:start position:0% +carbon or Boron and although these + + + align:start position:0% +carbon or Boron and although these +impurities have many more electrons than + + align:start position:0% +impurities have many more electrons than + + + align:start position:0% +impurities have many more electrons than +hydrogen um they are in the center of + + align:start position:0% +hydrogen um they are in the center of + + + align:start position:0% +hydrogen um they are in the center of +the machine probably fully stripped + + align:start position:0% +the machine probably fully stripped + + + align:start position:0% +the machine probably fully stripped +they've lost all of their electrons so + + align:start position:0% +they've lost all of their electrons so + + + align:start position:0% +they've lost all of their electrons so +they no longer can produce any line so + + align:start position:0% +they no longer can produce any line so + + + align:start position:0% +they no longer can produce any line so +we can't detect their presence in the + + align:start position:0% +we can't detect their presence in the + + + align:start position:0% +we can't detect their presence in the +machine so we don't know where these + + align:start position:0% +machine so we don't know where these + + + align:start position:0% +machine so we don't know where these +impurities are so the idea of charge + + align:start position:0% +impurities are so the idea of charge + + + align:start position:0% +impurities are so the idea of charge +exchange recombination spectroscopy is + + align:start position:0% +exchange recombination spectroscopy is + + + align:start position:0% +exchange recombination spectroscopy is +we put our neutral beam through the + + align:start position:0% + + + + align:start position:0% + +machine and we end up uh charge + + align:start position:0% +machine and we end up uh charge + + + align:start position:0% +machine and we end up uh charge +exchanging on these impurities so we + + align:start position:0% +exchanging on these impurities so we + + + align:start position:0% +exchanging on these impurities so we +have some neutral beam uh and some + + align:start position:0% +have some neutral beam uh and some + + + align:start position:0% +have some neutral beam uh and some +impurity in a + + align:start position:0% +impurity in a + + + align:start position:0% +impurity in a +state Z Plus where it's ionized Z times + + align:start position:0% +state Z Plus where it's ionized Z times + + + align:start position:0% +state Z Plus where it's ionized Z times +and this charge exchanges and gives us a + + align:start position:0% +and this charge exchanges and gives us a + + + align:start position:0% +and this charge exchanges and gives us a +neutral beam ion + + align:start position:0% +neutral beam ion + + + align:start position:0% +neutral beam ion +plus an impurity in a state Z minus one + + align:start position:0% +plus an impurity in a state Z minus one + + + align:start position:0% +plus an impurity in a state Z minus one +plus and most importantly it's likely + + align:start position:0% +plus and most importantly it's likely + + + align:start position:0% +plus and most importantly it's likely +that the impurity will end up in an + + align:start position:0% +that the impurity will end up in an + + + align:start position:0% +that the impurity will end up in an +excited + + align:start position:0% + + + + align:start position:0% + +state so then our impurity which is in + + align:start position:0% +state so then our impurity which is in + + + align:start position:0% +state so then our impurity which is in +some excited state it will spontaneously + + align:start position:0% +some excited state it will spontaneously + + + align:start position:0% +some excited state it will spontaneously +Decay down and we'll get out a photon + + align:start position:0% +Decay down and we'll get out a photon + + + align:start position:0% +Decay down and we'll get out a photon +like that and because this Photon will + + align:start position:0% +like that and because this Photon will + + + align:start position:0% +like that and because this Photon will +have a characteristic energy that we're + + align:start position:0% +have a characteristic energy that we're + + + align:start position:0% +have a characteristic energy that we're +looking for with our spectrometer we can + + align:start position:0% +looking for with our spectrometer we can + + + align:start position:0% +looking for with our spectrometer we can +say aha this is from an + + align:start position:0% +say aha this is from an + + + align:start position:0% +say aha this is from an +impurity and now the invisible + + align:start position:0% +impurity and now the invisible + + + align:start position:0% +impurity and now the invisible +impurities are visible + + align:start position:0% +impurities are visible + + + align:start position:0% +impurities are visible +again so there are a few things that we + + align:start position:0% +again so there are a few things that we + + + align:start position:0% +again so there are a few things that we +can measure from charge exchange + + align:start position:0% +can measure from charge exchange + + + align:start position:0% +can measure from charge exchange +recombination spectroscopy we can + + align:start position:0% +recombination spectroscopy we can + + + align:start position:0% +recombination spectroscopy we can +measure the density of impurities from + + align:start position:0% + + + + align:start position:0% + +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +so you need sum Atomic models and you + + align:start position:0% +so you need sum Atomic models and you + + + align:start position:0% +so you need sum Atomic models and you +need an absolute calibration for your + + align:start position:0% +need an absolute calibration for your + + + align:start position:0% +need an absolute calibration for your +detector but you can work out the + + align:start position:0% +detector but you can work out the + + + align:start position:0% +detector but you can work out the +density of these impurities that's + + align:start position:0% +density of these impurities that's + + + align:start position:0% +density of these impurities that's +pretty useful we can also measure TI and + + align:start position:0% +pretty useful we can also measure TI and + + + align:start position:0% +pretty useful we can also measure TI and +V flow from the + + align:start position:0% + + + + align:start position:0% + +Doppler + + align:start position:0% + + + + align:start position:0% + +broadening and the doler shift + + align:start position:0% +broadening and the doler shift + + + align:start position:0% +broadening and the doler shift +respectively so as we discussed in the + + align:start position:0% +respectively so as we discussed in the + + + align:start position:0% +respectively so as we discussed in the +spectroscopy you weeks ago or a week ago + + align:start position:0% +spectroscopy you weeks ago or a week ago + + + align:start position:0% +spectroscopy you weeks ago or a week ago +when we're talking about different + + align:start position:0% +when we're talking about different + + + align:start position:0% +when we're talking about different +broadening mechanisms uh these + + align:start position:0% +broadening mechanisms uh these + + + align:start position:0% +broadening mechanisms uh these +effectively can be the impurities which + + align:start position:0% +effectively can be the impurities which + + + align:start position:0% +effectively can be the impurities which +are acting as a tracer for the flow + + align:start position:0% +are acting as a tracer for the flow + + + align:start position:0% +are acting as a tracer for the flow +velocity so like our bulk motion of the + + align:start position:0% +velocity so like our bulk motion of the + + + align:start position:0% +velocity so like our bulk motion of the +entire plasma around the Taurus and for + + align:start position:0% +entire plasma around the Taurus and for + + + align:start position:0% +entire plasma around the Taurus and for +the temperature and again the reason is + + align:start position:0% +the temperature and again the reason is + + + align:start position:0% +the temperature and again the reason is +that uh maybe you could r on an impurity + + align:start position:0% +that uh maybe you could r on an impurity + + + align:start position:0% +that uh maybe you could r on an impurity +that was very high Z and still had some + + align:start position:0% +that was very high Z and still had some + + + align:start position:0% +that was very high Z and still had some +electrons left but if you done a really + + align:start position:0% +electrons left but if you done a really + + + align:start position:0% +electrons left but if you done a really +good job of reducing all of the tonsen + + align:start position:0% +good job of reducing all of the tonsen + + + align:start position:0% +good job of reducing all of the tonsen +and nasty things in your machine and all + + align:start position:0% +and nasty things in your machine and all + + + align:start position:0% +and nasty things in your machine and all +your left is oxygen carbon and Boron uh + + align:start position:0% +your left is oxygen carbon and Boron uh + + + align:start position:0% +your left is oxygen carbon and Boron uh +then you need to effectively give them + + align:start position:0% +then you need to effectively give them + + + align:start position:0% +then you need to effectively give them +back an electrons so you can do + + align:start position:0% +back an electrons so you can do + + + align:start position:0% +back an electrons so you can do +spectroscopy on them and again this is a + + align:start position:0% +spectroscopy on them and again this is a + + + align:start position:0% +spectroscopy on them and again this is a +nice active diagnostic because you can + + align:start position:0% +nice active diagnostic because you can + + + align:start position:0% +nice active diagnostic because you can +localize the region where you know the + + align:start position:0% +localize the region where you know the + + + align:start position:0% +localize the region where you know the +particles are sitting in by putting your + + align:start position:0% +particles are sitting in by putting your + + + align:start position:0% +particles are sitting in by putting your +spectrometer perpendicular to the line + + align:start position:0% +spectrometer perpendicular to the line + + + align:start position:0% +spectrometer perpendicular to the line +of sight of your neutral + + align:start position:0% +of sight of your neutral + + + align:start position:0% +of sight of your neutral +beam and + + align:start position:0% +beam and + + + align:start position:0% +beam and +again you can localize it flat region + + align:start position:0% +again you can localize it flat region + + + align:start position:0% +again you can localize it flat region +here so this gives you these two and + + align:start position:0% +here so this gives you these two and + + + align:start position:0% +here so this gives you these two and +they're all localized + + align:start position:0% + + + + align:start position:0% + +measurements + + align:start position:0% + + + + align:start position:0% + +um there there are can be problems with + + align:start position:0% +um there there are can be problems with + + + align:start position:0% +um there there are can be problems with +this + + align:start position:0% +this + + + align:start position:0% +this +um so one issue is you get uh charge + + align:start position:0% +um so one issue is you get uh charge + + + align:start position:0% +um so one issue is you get uh charge +exchange with Edge + + align:start position:0% + + + + align:start position:0% + +impurities I know I said this + + align:start position:0% +impurities I know I said this + + + align:start position:0% +impurities I know I said this +measurement localizes this but you could + + align:start position:0% +measurement localizes this but you could + + + align:start position:0% +measurement localizes this but you could +imagine that you could get light + + align:start position:0% +imagine that you could get light + + + align:start position:0% +imagine that you could get light +reflecting from here fill back down into + + align:start position:0% +reflecting from here fill back down into + + + align:start position:0% +reflecting from here fill back down into +your detector and you can also just have + + align:start position:0% +your detector and you can also just have + + + align:start position:0% +your detector and you can also just have +background so something like Ram stong + + align:start position:0% +background so something like Ram stong + + + align:start position:0% +background so something like Ram stong +radiation at this Photon energy and + + align:start position:0% +radiation at this Photon energy and + + + align:start position:0% +radiation at this Photon energy and +because there's not so many impurities + + align:start position:0% +because there's not so many impurities + + + align:start position:0% +because there's not so many impurities +we hope and not so many of them are + + align:start position:0% +we hope and not so many of them are + + + align:start position:0% +we hope and not so many of them are +charging exchanging neutral beam the + + align:start position:0% +charging exchanging neutral beam the + + + align:start position:0% +charging exchanging neutral beam the +signal could be relatively weak so this + + align:start position:0% +signal could be relatively weak so this + + + align:start position:0% +signal could be relatively weak so this +brem ston at that uh the the photon + + align:start position:0% +brem ston at that uh the the photon + + + align:start position:0% +brem ston at that uh the the photon +energy of the charge exchange with + + align:start position:0% +energy of the charge exchange with + + + align:start position:0% +energy of the charge exchange with +impurities that could be a significant + + align:start position:0% +impurities that could be a significant + + + align:start position:0% +impurities that could be a significant +uh amount so we may not be able to see + + align:start position:0% +uh amount so we may not be able to see + + + align:start position:0% +uh amount so we may not be able to see +this signal very clearly so a really + + align:start position:0% +this signal very clearly so a really + + + align:start position:0% +this signal very clearly so a really +neat trick that you can + + align:start position:0% +neat trick that you can + + + align:start position:0% +neat trick that you can +do is to modulate the + + align:start position:0% + + + + align:start position:0% + +be so you + + align:start position:0% +be so you + + + align:start position:0% +be so you +take the intensity of your neutral beam + + align:start position:0% +take the intensity of your neutral beam + + + align:start position:0% +take the intensity of your neutral beam +and you just turn it on and + + align:start position:0% +and you just turn it on and + + + align:start position:0% +and you just turn it on and +off like that and then when you look at + + align:start position:0% +off like that and then when you look at + + + align:start position:0% +off like that and then when you look at +the + + align:start position:0% +the + + + align:start position:0% +the +intensity at this specific wavelength + + align:start position:0% +intensity at this specific wavelength + + + align:start position:0% +intensity at this specific wavelength +that you're on the lookout for you + + align:start position:0% +that you're on the lookout for you + + + align:start position:0% +that you're on the lookout for you +should see that there's maybe some + + align:start position:0% + + + + align:start position:0% + +background but that background is being + + align:start position:0% +background but that background is being + + + align:start position:0% +background but that background is being +modulated by the neutral beam and then + + align:start position:0% +modulated by the neutral beam and then + + + align:start position:0% +modulated by the neutral beam and then +you can do tricks with like phase lock + + align:start position:0% +you can do tricks with like phase lock + + + align:start position:0% +you can do tricks with like phase lock +loops and all your other favorite for + + align:start position:0% +loops and all your other favorite for + + + align:start position:0% +loops and all your other favorite for +transform techniques and you can isolate + + align:start position:0% +transform techniques and you can isolate + + + align:start position:0% +transform techniques and you can isolate +out which part of this signal is + + align:start position:0% +out which part of this signal is + + + align:start position:0% +out which part of this signal is +actually due + + align:start position:0% +actually due + + + align:start position:0% +actually due +to exchange and which part of the signal + + align:start position:0% +to exchange and which part of the signal + + + align:start position:0% +to exchange and which part of the signal +is due to + + align:start position:0% +is due to + + + align:start position:0% +is due to +RS that's pretty neat okay questions on + + align:start position:0% +RS that's pretty neat okay questions on + + + align:start position:0% +RS that's pretty neat okay questions on +CH + + align:start position:0% + + + + align:start position:0% + +yes so + + align:start position:0% + + + + align:start position:0% + +theoretically we have just a single line + + align:start position:0% +theoretically we have just a single line + + + align:start position:0% +theoretically we have just a single line +like this if all the particles were + + align:start position:0% +like this if all the particles were + + + align:start position:0% +like this if all the particles were +stationary and uh the temperature was + + align:start position:0% +stationary and uh the temperature was + + + align:start position:0% +stationary and uh the temperature was +Zero all the particles moving at the + + align:start position:0% +Zero all the particles moving at the + + + align:start position:0% +Zero all the particles moving at the +same speed and we just have a line at + + align:start position:0% +same speed and we just have a line at + + + align:start position:0% +same speed and we just have a line at +Omega 0 if all the particles are moving + + align:start position:0% +Omega 0 if all the particles are moving + + + align:start position:0% +Omega 0 if all the particles are moving +in the same direction this will be + + align:start position:0% +in the same direction this will be + + + align:start position:0% +in the same direction this will be +Doppler + + align:start position:0% + + + + align:start position:0% + +shifted and that Doppler shift will be P + + align:start position:0% +shifted and that Doppler shift will be P + + + align:start position:0% +shifted and that Doppler shift will be P +doted into the flow velocity and if we + + align:start position:0% +doted into the flow velocity and if we + + + align:start position:0% +doted into the flow velocity and if we +have some broadening on top of that + + align:start position:0% +have some broadening on top of that + + + align:start position:0% +have some broadening on top of that +because we've got nonzero temperature + + align:start position:0% +because we've got nonzero temperature + + + align:start position:0% +because we've got nonzero temperature +some of the particles although they're + + align:start position:0% +some of the particles although they're + + + align:start position:0% +some of the particles although they're +all moving in One Direction some of them + + align:start position:0% +all moving in One Direction some of them + + + align:start position:0% +all moving in One Direction some of them +moving back a little bit and some are + + align:start position:0% +moving back a little bit and some are + + + align:start position:0% +moving back a little bit and some are +moving forwards and then the width of + + align:start position:0% +moving forwards and then the width of + + + align:start position:0% +moving forwards and then the width of +this feature full width of half maximum + + align:start position:0% +this feature full width of half maximum + + + align:start position:0% +this feature full width of half maximum +is proportional to vtii which is square + + align:start position:0% +is proportional to vtii which is square + + + align:start position:0% +is proportional to vtii which is square +root of temperature so you measure the + + align:start position:0% +root of temperature so you measure the + + + align:start position:0% +root of temperature so you measure the +shift of the feature and the broading of + + align:start position:0% +shift of the feature and the broading of + + + align:start position:0% +shift of the feature and the broading of +the feature that gives you the velocity + + align:start position:0% +the feature that gives you the velocity + + + align:start position:0% +the feature that gives you the velocity +and the temperature + + align:start position:0% + + + + align:start position:0% + +in any other + + align:start position:0% + + + + align:start position:0% + +questions any questions + + align:start position:0% + + + + align:start position:0% + +online + + align:start position:0% + + + + align:start position:0% + +okay next + + align:start position:0% + + + + align:start position:0% + +topic there are yet more fun things you + + align:start position:0% +topic there are yet more fun things you + + + align:start position:0% +topic there are yet more fun things you +can do with a neutral beam who would + + align:start position:0% +can do with a neutral beam who would + + + align:start position:0% +can do with a neutral beam who would +have thought + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +next one thing you can do as a neutral + + align:start position:0% +next one thing you can do as a neutral + + + align:start position:0% +next one thing you can do as a neutral +beam is something called + + align:start position:0% + + + + align:start position:0% + +beam + + align:start position:0% + + + + align:start position:0% + +emission + + align:start position:0% + + + + align:start position:0% + +spectroscopy + + align:start position:0% + + + + align:start position:0% + +bees the idea here once again vacuum + + align:start position:0% +bees the idea here once again vacuum + + + align:start position:0% +bees the idea here once again vacuum +chamber + + align:start position:0% + + + + align:start position:0% + +plasma neutral + + align:start position:0% + + + + align:start position:0% + +beam as the beam goes through the plasma + + align:start position:0% +beam as the beam goes through the plasma + + + align:start position:0% +beam as the beam goes through the plasma +remember our beam is going to be + + align:start position:0% +remember our beam is going to be + + + align:start position:0% +remember our beam is going to be +hydrogen or uterum or something like + + align:start position:0% +hydrogen or uterum or something like + + + align:start position:0% +hydrogen or uterum or something like +that the neutrals inside here and these + + align:start position:0% +that the neutrals inside here and these + + + align:start position:0% +that the neutrals inside here and these +are all neutrals so I'll just put a + + align:start position:0% +are all neutrals so I'll just put a + + + align:start position:0% +are all neutrals so I'll just put a +little zero to remind ourselves they're + + align:start position:0% +little zero to remind ourselves they're + + + align:start position:0% +little zero to remind ourselves they're +neutrals um will have some glancing + + align:start position:0% +neutrals um will have some glancing + + + align:start position:0% +neutrals um will have some glancing +collisions of the electrons and ions not + + align:start position:0% +collisions of the electrons and ions not + + + align:start position:0% +collisions of the electrons and ions not +enough to ionize them some of the + + align:start position:0% +enough to ionize them some of the + + + align:start position:0% +enough to ionize them some of the +collisions will ionize them but some of + + align:start position:0% +collisions will ionize them but some of + + + align:start position:0% +collisions will ionize them but some of +the collisions will be enough to excite + + align:start position:0% +the collisions will be enough to excite + + + align:start position:0% +the collisions will be enough to excite +these right and so we'll end up inside + + align:start position:0% +these right and so we'll end up inside + + + align:start position:0% +these right and so we'll end up inside +our Beam with excited neutral hydrogen + + align:start position:0% +our Beam with excited neutral hydrogen + + + align:start position:0% +our Beam with excited neutral hydrogen +and excited neutral uterum or something + + align:start position:0% +and excited neutral uterum or something + + + align:start position:0% +and excited neutral uterum or something +like + + align:start position:0% +like + + + align:start position:0% +like +that and we can then put our + + align:start position:0% +that and we can then put our + + + align:start position:0% +that and we can then put our +spectrometer down here or our detector + + align:start position:0% +spectrometer down here or our detector + + + align:start position:0% +spectrometer down here or our detector +down here and we can look for the + + align:start position:0% +down here and we can look for the + + + align:start position:0% +down here and we can look for the +characteristic I actually have some + + align:start position:0% +characteristic I actually have some + + + align:start position:0% +characteristic I actually have some +drawings of + + align:start position:0% +drawings of + + + align:start position:0% +drawings of +this no okay we can look for these + + align:start position:0% +this no okay we can look for these + + + align:start position:0% +this no okay we can look for these +characteristic uh decays here and if you + + align:start position:0% +characteristic uh decays here and if you + + + align:start position:0% +characteristic uh decays here and if you +remember before we we talked about the + + align:start position:0% +remember before we we talked about the + + + align:start position:0% +remember before we we talked about the +Lyman Alpha and beta and the balma + + align:start position:0% +Lyman Alpha and beta and the balma + + + align:start position:0% +Lyman Alpha and beta and the balma +series as well so we know very well + + align:start position:0% +series as well so we know very well + + + align:start position:0% +series as well so we know very well +defined what these uh energies of the + + align:start position:0% +defined what these uh energies of the + + + align:start position:0% +defined what these uh energies of the +photons coming out are going to be now + + align:start position:0% +photons coming out are going to be now + + + align:start position:0% +photons coming out are going to be now +the neat thing about this is the + + align:start position:0% +the neat thing about this is the + + + align:start position:0% +the neat thing about this is the +intensity of these + + align:start position:0% +intensity of these + + + align:start position:0% +intensity of these +lines is proportional to or is I'll make + + align:start position:0% +lines is proportional to or is I'll make + + + align:start position:0% +lines is proportional to or is I'll make +it stronger is directly proportional to + + align:start position:0% +it stronger is directly proportional to + + + align:start position:0% +it stronger is directly proportional to +the number of electrons in the plasma + + align:start position:0% +the number of electrons in the plasma + + + align:start position:0% +the number of electrons in the plasma +because this is a collisional excitation + + align:start position:0% +because this is a collisional excitation + + + align:start position:0% +because this is a collisional excitation +process and we know that that is propal + + align:start position:0% +process and we know that that is propal + + + align:start position:0% +process and we know that that is propal +to any and then whatever the + + align:start position:0% +to any and then whatever the + + + align:start position:0% +to any and then whatever the +relevant collisional excitation + + align:start position:0% +relevant collisional excitation + + + align:start position:0% +relevant collisional excitation +crosssection is okay but the main thing + + align:start position:0% +crosssection is okay but the main thing + + + align:start position:0% +crosssection is okay but the main thing +is it's proportional to the + + align:start position:0% +is it's proportional to the + + + align:start position:0% +is it's proportional to the +density so the neat thing is if I now + + align:start position:0% +density so the neat thing is if I now + + + align:start position:0% +density so the neat thing is if I now +have density + + align:start position:0% +have density + + + align:start position:0% +have density +fluctuations so this is we've got some + + align:start position:0% +fluctuations so this is we've got some + + + align:start position:0% +fluctuations so this is we've got some +background density but the density is + + align:start position:0% +background density but the density is + + + align:start position:0% +background density but the density is +fluctuating on top of that so you know + + align:start position:0% +fluctuating on top of that so you know + + + align:start position:0% +fluctuating on top of that so you know +any Z Plus Delta NE of T then that's + + align:start position:0% +any Z Plus Delta NE of T then that's + + + align:start position:0% +any Z Plus Delta NE of T then that's +going to give me + + align:start position:0% +going to give me + + + align:start position:0% +going to give me +an intensity fluctuation as + + align:start position:0% + + + + align:start position:0% + +well so by carefully measuring the + + align:start position:0% +well so by carefully measuring the + + + align:start position:0% +well so by carefully measuring the +intensity of these lines and again we + + align:start position:0% +intensity of these lines and again we + + + align:start position:0% +intensity of these lines and again we +can localize this relatively well + + align:start position:0% +can localize this relatively well + + + align:start position:0% +can localize this relatively well +because I have a specific field of view + + align:start position:0% +because I have a specific field of view + + + align:start position:0% +because I have a specific field of view +of my detector and I know where this uh + + align:start position:0% +of my detector and I know where this uh + + + align:start position:0% +of my detector and I know where this uh +beam emission is coming from so I can + + align:start position:0% +beam emission is coming from so I can + + + align:start position:0% +beam emission is coming from so I can +localize it to a little region I could + + align:start position:0% +localize it to a little region I could + + + align:start position:0% +localize it to a little region I could +have multiple detectors and I can have + + align:start position:0% +have multiple detectors and I can have + + + align:start position:0% +have multiple detectors and I can have +another one looking here I can measure + + align:start position:0% +another one looking here I can measure + + + align:start position:0% +another one looking here I can measure +density fluctuations in very precise + + align:start position:0% +density fluctuations in very precise + + + align:start position:0% +density fluctuations in very precise +regions here and density fluctuations + + align:start position:0% +regions here and density fluctuations + + + align:start position:0% +regions here and density fluctuations +are very important especially in + + align:start position:0% +are very important especially in + + + align:start position:0% +are very important especially in +magnetic confinement Fusion because + + align:start position:0% +magnetic confinement Fusion because + + + align:start position:0% +magnetic confinement Fusion because +these fluctuations lead to transport + + align:start position:0% +these fluctuations lead to transport + + + align:start position:0% +these fluctuations lead to transport +turbulent transport so we really really + + align:start position:0% +turbulent transport so we really really + + + align:start position:0% +turbulent transport so we really really +want to be + + align:start position:0% +want to be + + + align:start position:0% +want to be +a um so beam emission spectroscopy I + + align:start position:0% +a um so beam emission spectroscopy I + + + align:start position:0% +a um so beam emission spectroscopy I +think this is the only slide I have on + + align:start position:0% +think this is the only slide I have on + + + align:start position:0% +think this is the only slide I have on +this yes um well I have another one + + align:start position:0% +this yes um well I have another one + + + align:start position:0% +this yes um well I have another one +that's related this is a very cool + + align:start position:0% +that's related this is a very cool + + + align:start position:0% +that's related this is a very cool +technique um the trouble is that what I + + align:start position:0% +technique um the trouble is that what I + + + align:start position:0% +technique um the trouble is that what I +just said + + align:start position:0% +just said + + + align:start position:0% +just said +here about just being proportional to + + align:start position:0% +here about just being proportional to + + + align:start position:0% +here about just being proportional to +density here this is rather simple + + align:start position:0% +density here this is rather simple + + + align:start position:0% +density here this is rather simple +it's not actually true in reality so + + align:start position:0% +it's not actually true in reality so + + + align:start position:0% +it's not actually true in reality so +what we actually have to do um is + + align:start position:0% + + + + align:start position:0% + +include all relevant processes this is + + align:start position:0% +include all relevant processes this is + + + align:start position:0% +include all relevant processes this is +going back to spectroscopy again where + + align:start position:0% +going back to spectroscopy again where + + + align:start position:0% +going back to spectroscopy again where +if you're not quite in a simple + + align:start position:0% +if you're not quite in a simple + + + align:start position:0% +if you're not quite in a simple +equilibrium you need to include lots + + align:start position:0% +equilibrium you need to include lots + + + align:start position:0% +equilibrium you need to include lots +more + + align:start position:0% + + + + align:start position:0% + +processes and you also need to include + + align:start position:0% +processes and you also need to include + + + align:start position:0% +processes and you also need to include +the beam's attenuation because of course + + align:start position:0% +the beam's attenuation because of course + + + align:start position:0% +the beam's attenuation because of course +the point of launching a neutral beam + + align:start position:0% +the point of launching a neutral beam + + + align:start position:0% +the point of launching a neutral beam +into your system is not to hit the far + + align:start position:0% +into your system is not to hit the far + + + align:start position:0% +into your system is not to hit the far +wall of your vacuum chamber and melt it + + align:start position:0% +wall of your vacuum chamber and melt it + + + align:start position:0% +wall of your vacuum chamber and melt it +but it's actually to charge exchange + + align:start position:0% +but it's actually to charge exchange + + + align:start position:0% +but it's actually to charge exchange +with the plasma and heat it and drive + + align:start position:0% +with the plasma and heat it and drive + + + align:start position:0% +with the plasma and heat it and drive +current so this beam is going to be + + align:start position:0% +current so this beam is going to be + + + align:start position:0% +current so this beam is going to be +getting less and less intense as it goes + + align:start position:0% +getting less and less intense as it goes + + + align:start position:0% +getting less and less intense as it goes +through the plasma and so if you want to + + align:start position:0% +through the plasma and so if you want to + + + align:start position:0% +through the plasma and so if you want to +do all this properly you also need to + + align:start position:0% +do all this properly you also need to + + + align:start position:0% +do all this properly you also need to +track the beam attenuation because this + + align:start position:0% +track the beam attenuation because this + + + align:start position:0% +track the beam attenuation because this +density is also proportional to the + + align:start position:0% +density is also proportional to the + + + align:start position:0% +density is also proportional to the +number + + align:start position:0% +number + + + align:start position:0% +number +of beam particles as well or number + + align:start position:0% +of beam particles as well or number + + + align:start position:0% +of beam particles as well or number +density of beam particles so we need to + + align:start position:0% +density of beam particles so we need to + + + align:start position:0% +density of beam particles so we need to +attct the beam + + align:start position:0% + + + + align:start position:0% + +attenuation but if you can do that this + + align:start position:0% +attenuation but if you can do that this + + + align:start position:0% +attenuation but if you can do that this +is potentially a very powerful + + align:start position:0% +is potentially a very powerful + + + align:start position:0% +is potentially a very powerful +diagnostic for measuring density + + align:start position:0% +diagnostic for measuring density + + + align:start position:0% +diagnostic for measuring density +fluctuations which are otherwise quite + + align:start position:0% +fluctuations which are otherwise quite + + + align:start position:0% +fluctuations which are otherwise quite +challenging for + + align:start position:0% +challenging for + + + align:start position:0% +challenging for +meas questions on beam Mission + + align:start position:0% +meas questions on beam Mission + + + align:start position:0% +meas questions on beam Mission +spectroscopy uh Professor yes um so do + + align:start position:0% +spectroscopy uh Professor yes um so do + + + align:start position:0% +spectroscopy uh Professor yes um so do +you need to specialize your neutral Beam + + align:start position:0% +you need to specialize your neutral Beam + + + align:start position:0% +you need to specialize your neutral Beam +for these kind of readings or is it + + align:start position:0% +for these kind of readings or is it + + + align:start position:0% +for these kind of readings or is it +something you can do while using the + + align:start position:0% +something you can do while using the + + + align:start position:0% +something you can do while using the +neutral beam as a heating Source already + + align:start position:0% +neutral beam as a heating Source already + + + align:start position:0% +neutral beam as a heating Source already +yes the nice thing about all of these + + align:start position:0% +yes the nice thing about all of these + + + align:start position:0% +yes the nice thing about all of these +things is you tend to just be able to + + align:start position:0% +things is you tend to just be able to + + + align:start position:0% +things is you tend to just be able to +use your standard neutral beam so some + + align:start position:0% +use your standard neutral beam so some + + + align:start position:0% +use your standard neutral beam so some +people do have specifically made + + align:start position:0% +people do have specifically made + + + align:start position:0% +people do have specifically made +diagnostic neutral beams so on eer they + + align:start position:0% +diagnostic neutral beams so on eer they + + + align:start position:0% +diagnostic neutral beams so on eer they +have several neutral beams specifically + + align:start position:0% +have several neutral beams specifically + + + align:start position:0% +have several neutral beams specifically +designed for heating and they also have + + align:start position:0% +designed for heating and they also have + + + align:start position:0% +designed for heating and they also have +diagnostic neutral beams so the heating + + align:start position:0% +diagnostic neutral beams so the heating + + + align:start position:0% +diagnostic neutral beams so the heating +beams are up at Mega electron volts and + + align:start position:0% +beams are up at Mega electron volts and + + + align:start position:0% +beams are up at Mega electron volts and +the diagnostic beam is at a lower energy + + align:start position:0% +the diagnostic beam is at a lower energy + + + align:start position:0% +the diagnostic beam is at a lower energy +and I believe that lower energy is + + align:start position:0% +and I believe that lower energy is + + + align:start position:0% +and I believe that lower energy is +because it gives you better + + align:start position:0% +because it gives you better + + + align:start position:0% +because it gives you better +cross-sections for all these processes + + align:start position:0% +cross-sections for all these processes + + + align:start position:0% +cross-sections for all these processes +so I'm not sure um an amusing example of + + align:start position:0% +so I'm not sure um an amusing example of + + + align:start position:0% +so I'm not sure um an amusing example of +that is that there was a diagnostic + + align:start position:0% +that is that there was a diagnostic + + + align:start position:0% +that is that there was a diagnostic +neutral be + + align:start position:0% +neutral be + + + align:start position:0% +neutral be +developed for the national compact + + align:start position:0% +developed for the national compact + + + align:start position:0% +developed for the national compact +accelerator experiment of Princeton + + align:start position:0% +accelerator experiment of Princeton + + + align:start position:0% +accelerator experiment of Princeton +which was cancelled and that diagnostic + + align:start position:0% +which was cancelled and that diagnostic + + + align:start position:0% +which was cancelled and that diagnostic +neutral beam then went on to be the + + align:start position:0% +neutral beam then went on to be the + + + align:start position:0% +neutral beam then went on to be the +heating neutral Beam for a much smaller + + align:start position:0% +heating neutral Beam for a much smaller + + + align:start position:0% +heating neutral Beam for a much smaller +device so you know you can build a + + align:start position:0% +device so you know you can build a + + + align:start position:0% +device so you know you can build a +diagnostic neutral beam but at the end + + align:start position:0% +diagnostic neutral beam but at the end + + + align:start position:0% +diagnostic neutral beam but at the end +of the day it's still a neutral beam it + + align:start position:0% +of the day it's still a neutral beam it + + + align:start position:0% +of the day it's still a neutral beam it +can do whatever you you normally want + + align:start position:0% +can do whatever you you normally want + + + align:start position:0% +can do whatever you you normally want +this is going to be coming in at 300 K + + align:start position:0% +this is going to be coming in at 300 K + + + align:start position:0% +this is going to be coming in at 300 K +or whatever energy you can generate and + + align:start position:0% +or whatever energy you can generate and + + + align:start position:0% +or whatever energy you can generate and +all these processes are going to be + + align:start position:0% +all these processes are going to be + + + align:start position:0% +all these processes are going to be +happening and the fact that the beam + + align:start position:0% +happening and the fact that the beam + + + align:start position:0% +happening and the fact that the beam +slows down and converts into ions and + + align:start position:0% +slows down and converts into ions and + + + align:start position:0% +slows down and converts into ions and +does all the heating relies on all of + + align:start position:0% +does all the heating relies on all of + + + align:start position:0% +does all the heating relies on all of +the same atomic processes that we then + + align:start position:0% +the same atomic processes that we then + + + align:start position:0% +the same atomic processes that we then +use to observe beam emission + + align:start position:0% +use to observe beam emission + + + align:start position:0% +use to observe beam emission +spectroscopy and charge exchange and all + + align:start position:0% +spectroscopy and charge exchange and all + + + align:start position:0% +spectroscopy and charge exchange and all +that sort of stuff so like those + + align:start position:0% +that sort of stuff so like those + + + align:start position:0% +that sort of stuff so like those +processes have to happen for the beam to + + align:start position:0% +processes have to happen for the beam to + + + align:start position:0% +processes have to happen for the beam to +work and now you're just observing the + + align:start position:0% +work and now you're just observing the + + + align:start position:0% +work and now you're just observing the +obvious consequence of the yeah good + + align:start position:0% +obvious consequence of the yeah good + + + align:start position:0% +obvious consequence of the yeah good +question great thank you other + + align:start position:0% + + + + align:start position:0% + +question now we're going to be done + + align:start position:0% +question now we're going to be done + + + align:start position:0% +question now we're going to be done +early all right final thing as we + + align:start position:0% +early all right final thing as we + + + align:start position:0% +early all right final thing as we +discussed it the other day is emotional + + align:start position:0% +discussed it the other day is emotional + + + align:start position:0% +discussed it the other day is emotional +Stark effect which I had forgotten was + + align:start position:0% +Stark effect which I had forgotten was + + + align:start position:0% +Stark effect which I had forgotten was +to do with this and in fact I was + + align:start position:0% +to do with this and in fact I was + + + align:start position:0% +to do with this and in fact I was +looking through my notes today and I was + + align:start position:0% +looking through my notes today and I was + + + align:start position:0% +looking through my notes today and I was +like oh I actually wrote several pages + + align:start position:0% +like oh I actually wrote several pages + + + align:start position:0% +like oh I actually wrote several pages +of notes on emotional star effect and + + align:start position:0% +of notes on emotional star effect and + + + align:start position:0% +of notes on emotional star effect and +then told people I had no idea what it + + align:start position:0% +then told people I had no idea what it + + + align:start position:0% +then told people I had no idea what it +was so that just shows how good my + + align:start position:0% +was so that just shows how good my + + + align:start position:0% +was so that just shows how good my +memory is so now you will have the + + align:start position:0% +memory is so now you will have the + + + align:start position:0% +memory is so now you will have the +pleasure of learning about and then + + align:start position:0% +pleasure of learning about and then + + + align:start position:0% +pleasure of learning about and then +instantly forgetting about the emotional + + align:start position:0% +instantly forgetting about the emotional + + + align:start position:0% +instantly forgetting about the emotional +Stark effect no it's actually really + + align:start position:0% + + + + align:start position:0% + +cool say often abbreviated as + + align:start position:0% +cool say often abbreviated as + + + align:start position:0% +cool say often abbreviated as +M okay so we already talked + + align:start position:0% +M okay so we already talked + + + align:start position:0% +M okay so we already talked +about the Stark effect and in the Stark + + align:start position:0% +about the Stark effect and in the Stark + + + align:start position:0% +about the Stark effect and in the Stark +effect we said that there was an + + align:start position:0% +effect we said that there was an + + + align:start position:0% +effect we said that there was an +electric field and I'm going to continue + + align:start position:0% +electric field and I'm going to continue + + + align:start position:0% +electric field and I'm going to continue +writing electric with this weird curly e + + align:start position:0% +writing electric with this weird curly e + + + align:start position:0% +writing electric with this weird curly e +because we're GNA have capital E for + + align:start position:0% +because we're GNA have capital E for + + + align:start position:0% +because we're GNA have capital E for +energy later I don't want us to get + + align:start position:0% +energy later I don't want us to get + + + align:start position:0% +energy later I don't want us to get +confused so this is the electric field + + align:start position:0% +confused so this is the electric field + + + align:start position:0% +confused so this is the electric field +which + + align:start position:0% + + + + align:start position:0% + +shifts the energy + + align:start position:0% + + + + align:start position:0% + +levels + + align:start position:0% +levels + + + align:start position:0% +levels +of some + + align:start position:0% + + + + align:start position:0% + +atom so we could do this just in a + + align:start position:0% +atom so we could do this just in a + + + align:start position:0% +atom so we could do this just in a +laboratory was a strong electric field + + align:start position:0% +laboratory was a strong electric field + + + align:start position:0% +laboratory was a strong electric field +and a neutral gas + + align:start position:0% +and a neutral gas + + + align:start position:0% +and a neutral gas +um and we then considered what this does + + align:start position:0% +um and we then considered what this does + + + align:start position:0% +um and we then considered what this does +inside a plasma so in a plasma we have + + align:start position:0% +inside a plasma so in a plasma we have + + + align:start position:0% +inside a plasma so in a plasma we have +lots of electrons moving around as we + + align:start position:0% +lots of electrons moving around as we + + + align:start position:0% +lots of electrons moving around as we +said and those electrons will be + + align:start position:0% +said and those electrons will be + + + align:start position:0% +said and those electrons will be +colliding with our ions or our atoms + + align:start position:0% +colliding with our ions or our atoms + + + align:start position:0% +colliding with our ions or our atoms +that have bound electrons and those + + align:start position:0% +that have bound electrons and those + + + align:start position:0% +that have bound electrons and those +electrons get close they will be + + align:start position:0% +electrons get close they will be + + + align:start position:0% +electrons get close they will be +Shifting the uh electric field and + + align:start position:0% +Shifting the uh electric field and + + + align:start position:0% +Shifting the uh electric field and +therefore the energy level in the + + align:start position:0% +therefore the energy level in the + + + align:start position:0% +therefore the energy level in the +vicinity that atom so we saw there that + + align:start position:0% +vicinity that atom so we saw there that + + + align:start position:0% +vicinity that atom so we saw there that +we got a change in the energy of the + + align:start position:0% +we got a change in the energy of the + + + align:start position:0% +we got a change in the energy of the +photons being emitted which was + + align:start position:0% +photons being emitted which was + + + align:start position:0% +photons being emitted which was +proportional to the electric field and + + align:start position:0% +proportional to the electric field and + + + align:start position:0% +proportional to the electric field and +that electric field was proportional to + + align:start position:0% +that electric field was proportional to + + + align:start position:0% +that electric field was proportional to +density of the 1/3 and this was just a + + align:start position:0% +density of the 1/3 and this was just a + + + align:start position:0% +density of the 1/3 and this was just a +electric field one over r s i this + + align:start position:0% +electric field one over r s i this + + + align:start position:0% +electric field one over r s i this +should be + + align:start position:0% +should be + + + align:start position:0% +should be +two3 there we go okay this was from + + align:start position:0% + + + + align:start position:0% + +collisions + + align:start position:0% +collisions + + + align:start position:0% +collisions +but this whole picture here required a + + align:start position:0% +but this whole picture here required a + + + align:start position:0% +but this whole picture here required a +thermal plasma with lots of particles + + align:start position:0% +thermal plasma with lots of particles + + + align:start position:0% +thermal plasma with lots of particles +moving in all sorts of ways here so this + + align:start position:0% +moving in all sorts of ways here so this + + + align:start position:0% +moving in all sorts of ways here so this +was with the distribution F of e v that + + align:start position:0% +was with the distribution F of e v that + + + align:start position:0% +was with the distribution F of e v that +was exponential of I don't know minus + + align:start position:0% +was exponential of I don't know minus + + + align:start position:0% +was exponential of I don't know minus +v^2 over V3 e + + align:start position:0% +v^2 over V3 e + + + align:start position:0% +v^2 over V3 e +squ but in this case here for a neutral + + align:start position:0% + + + + align:start position:0% + +beam we have a very Peak distribution + + align:start position:0% +beam we have a very Peak distribution + + + align:start position:0% +beam we have a very Peak distribution +function so our distribution of neutral + + align:start position:0% + + + + align:start position:0% + +beam + + align:start position:0% +beam + + + align:start position:0% +beam +ions is a roughly a Delta function right + + align:start position:0% +ions is a roughly a Delta function right + + + align:start position:0% +ions is a roughly a Delta function right +so they're all at + + align:start position:0% + + + + align:start position:0% + +VB so we don't expect to see a broadness + + align:start position:0% +VB so we don't expect to see a broadness + + + align:start position:0% +VB so we don't expect to see a broadness +what we would expect to see maybe is + + align:start position:0% +what we would expect to see maybe is + + + align:start position:0% +what we would expect to see maybe is +some sort of shift in a single Direction + + align:start position:0% +some sort of shift in a single Direction + + + align:start position:0% +some sort of shift in a single Direction +here but where is the electric field + + align:start position:0% +here but where is the electric field + + + align:start position:0% +here but where is the electric field +coming up from in a plasma like this + + align:start position:0% +coming up from in a plasma like this + + + align:start position:0% +coming up from in a plasma like this +where we're just talking about our + + align:start position:0% +where we're just talking about our + + + align:start position:0% +where we're just talking about our +particles moving because here we argued + + align:start position:0% +particles moving because here we argued + + + align:start position:0% +particles moving because here we argued +this was the electric field from + + align:start position:0% +this was the electric field from + + + align:start position:0% +this was the electric field from +particles close in within the div + + align:start position:0% +particles close in within the div + + + align:start position:0% +particles close in within the div +bisphere but on large scales we don't + + align:start position:0% +bisphere but on large scales we don't + + + align:start position:0% +bisphere but on large scales we don't +see this electric field but what we do + + align:start position:0% +see this electric field but what we do + + + align:start position:0% +see this electric field but what we do +have is a magnetic field we have a + + align:start position:0% +have is a magnetic field we have a + + + align:start position:0% +have is a magnetic field we have a +magnetic field B like this and so we + + align:start position:0% +magnetic field B like this and so we + + + align:start position:0% +magnetic field B like this and so we +have some + + align:start position:0% +have some + + + align:start position:0% +have some +beam + + align:start position:0% +beam + + + align:start position:0% +beam +velocity V cross B and in the frame of + + align:start position:0% +velocity V cross B and in the frame of + + + align:start position:0% +velocity V cross B and in the frame of +the particle that creates an electric + + align:start position:0% +the particle that creates an electric + + + align:start position:0% +the particle that creates an electric +field which is equal to minus B cross B + + align:start position:0% +field which is equal to minus B cross B + + + align:start position:0% +field which is equal to minus B cross B +so this is our Lorent + + align:start position:0% + + + + align:start position:0% + +transform so in the frame of the lab we + + align:start position:0% +transform so in the frame of the lab we + + + align:start position:0% +transform so in the frame of the lab we +see particles moving with velocity the + + align:start position:0% +see particles moving with velocity the + + + align:start position:0% +see particles moving with velocity the +beam and we see a magnetic + + align:start position:0% + + + + align:start position:0% + +field but in the frame of the particle + + align:start position:0% +field but in the frame of the particle + + + align:start position:0% +field but in the frame of the particle +when we do the Laurence + + align:start position:0% +when we do the Laurence + + + align:start position:0% +when we do the Laurence +transformation the particle of course + + align:start position:0% +transformation the particle of course + + + align:start position:0% +transformation the particle of course +doesn't know it's moving we're in its + + align:start position:0% +doesn't know it's moving we're in its + + + align:start position:0% +doesn't know it's moving we're in its +frame and instead of seeing a magnetic + + align:start position:0% +frame and instead of seeing a magnetic + + + align:start position:0% +frame and instead of seeing a magnetic +field it sees this electric field + + align:start position:0% +field it sees this electric field + + + align:start position:0% +field it sees this electric field +instead okay and so that means that now + + align:start position:0% +instead okay and so that means that now + + + align:start position:0% +instead okay and so that means that now +we're expecting to get ngg shifts Delta + + align:start position:0% +we're expecting to get ngg shifts Delta + + + align:start position:0% +we're expecting to get ngg shifts Delta +e which are again proportional to the + + align:start position:0% +e which are again proportional to the + + + align:start position:0% +e which are again proportional to the +electric + + align:start position:0% +electric + + + align:start position:0% +electric +field which are now proportional to V + + align:start position:0% +field which are now proportional to V + + + align:start position:0% +field which are now proportional to V +cross + + align:start position:0% +cross + + + align:start position:0% +cross +B + + align:start position:0% +B + + + align:start position:0% +B +and I just want to point out and + + align:start position:0% +and I just want to point out and + + + align:start position:0% +and I just want to point out and +Hutchinson goes into this in some detail + + align:start position:0% +Hutchinson goes into this in some detail + + + align:start position:0% +Hutchinson goes into this in some detail +we've assumed here that we're talking + + align:start position:0% +we've assumed here that we're talking + + + align:start position:0% +we've assumed here that we're talking +about the linear Stark + + align:start position:0% +about the linear Stark + + + align:start position:0% +about the linear Stark +effect and depending on exactly what's + + align:start position:0% +effect and depending on exactly what's + + + align:start position:0% +effect and depending on exactly what's +going on you may need more complicated + + align:start position:0% +going on you may need more complicated + + + align:start position:0% +going on you may need more complicated +things like the quadratic Stark effect + + align:start position:0% +things like the quadratic Stark effect + + + align:start position:0% +things like the quadratic Stark effect +but this is the linear Stark effect it + + align:start position:0% +but this is the linear Stark effect it + + + align:start position:0% +but this is the linear Stark effect it +turns out the linear Stark effect is + + align:start position:0% +turns out the linear Stark effect is + + + align:start position:0% +turns out the linear Stark effect is +good when this Delta e is + + align:start position:0% + + + + align:start position:0% + +large so as long as you have + + align:start position:0% +large so as long as you have + + + align:start position:0% +large so as long as you have +sufficiently large magnetic field and uh + + align:start position:0% +sufficiently large magnetic field and uh + + + align:start position:0% +sufficiently large magnetic field and uh +beam velocities then you end up in this + + align:start position:0% +beam velocities then you end up in this + + + align:start position:0% +beam velocities then you end up in this +linear regim which is much easier to + + align:start position:0% +linear regim which is much easier to + + + align:start position:0% +linear regim which is much easier to +analyze + + align:start position:0% +analyze + + + align:start position:0% +analyze +here + + align:start position:0% +here + + + align:start position:0% +here +okay um I'm gonna erase this because I + + align:start position:0% +okay um I'm gonna erase this because I + + + align:start position:0% +okay um I'm gonna erase this because I +want to keep that on the + + align:start position:0% + + + + align:start position:0% + +board + + align:start position:0% +board + + + align:start position:0% +board +now some voodoo magic happens and we + + align:start position:0% +now some voodoo magic happens and we + + + align:start position:0% +now some voodoo magic happens and we +find out that we each energy level + + align:start position:0% +find out that we each energy level + + + align:start position:0% +find out that we each energy level +splits into multiple energy levels so + + align:start position:0% +splits into multiple energy levels so + + + align:start position:0% +splits into multiple energy levels so +this is reminiscent of the Zan spliting + + align:start position:0% +this is reminiscent of the Zan spliting + + + align:start position:0% +this is reminiscent of the Zan spliting +again so each energy level splits into + + align:start position:0% +again so each energy level splits into + + + align:start position:0% +again so each energy level splits into +energy levels whose energy is given by + + align:start position:0% +energy levels whose energy is given by + + + align:start position:0% +energy levels whose energy is given by +three n k I'll explain all of these + + align:start position:0% +three n k I'll explain all of these + + + align:start position:0% +three n k I'll explain all of these +symbols mean in a + + align:start position:0% +symbols mean in a + + + align:start position:0% +symbols mean in a +moment electric field + + align:start position:0% +moment electric field + + + align:start position:0% +moment electric field +over z + + align:start position:0% +over z + + + align:start position:0% +over z +e over 4 Pi Epsilon do a z + + align:start position:0% +e over 4 Pi Epsilon do a z + + + align:start position:0% +e over 4 Pi Epsilon do a z +Z squar I haven't got in my notes what a + + align:start position:0% +Z squar I haven't got in my notes what a + + + align:start position:0% +Z squar I haven't got in my notes what a +Zer is and I've forgotten what it is off + + align:start position:0% +Zer is and I've forgotten what it is off + + + align:start position:0% +Zer is and I've forgotten what it is off +to my head so that's not very + + align:start position:0% +to my head so that's not very + + + align:start position:0% +to my head so that's not very +useful some constant is the most + + align:start position:0% +useful some constant is the most + + + align:start position:0% +useful some constant is the most +important thing and all this times the + + align:start position:0% +important thing and all this times the + + + align:start position:0% +important thing and all this times the +rigberg energy which you all remember + + align:start position:0% +rigberg energy which you all remember + + + align:start position:0% +rigberg energy which you all remember +it's + + align:start position:0% +it's + + + align:start position:0% +it's +13.6 electron volts and this electric + + align:start position:0% +13.6 electron volts and this electric + + + align:start position:0% +13.6 electron volts and this electric +field is B cross B modulus of it okay so + + align:start position:0% +field is B cross B modulus of it okay so + + + align:start position:0% +field is B cross B modulus of it okay so +n here is the Quant + + align:start position:0% + + + + align:start position:0% + +number n equal 1 2 3 and K here for each + + align:start position:0% +number n equal 1 2 3 and K here for each + + + align:start position:0% +number n equal 1 2 3 and K here for each +quantum number n can take multiple + + align:start position:0% +quantum number n can take multiple + + + align:start position:0% +quantum number n can take multiple +values k equals Zer plus or minus one + + align:start position:0% +values k equals Zer plus or minus one + + + align:start position:0% +values k equals Zer plus or minus one +plus or minus + + align:start position:0% +plus or minus + + + align:start position:0% +plus or minus +2 up to plus or minus n minus + + align:start position:0% +2 up to plus or minus n minus + + + align:start position:0% +2 up to plus or minus n minus +1 so for Nal 1 K can only take the value + + align:start position:0% +1 so for Nal 1 K can only take the value + + + align:start position:0% +1 so for Nal 1 K can only take the value +zero for nals two it can take three + + align:start position:0% +zero for nals two it can take three + + + align:start position:0% +zero for nals two it can take three +values for n equals three it can take + + align:start position:0% +values for n equals three it can take + + + align:start position:0% +values for n equals three it can take +five values like + + align:start position:0% +five values like + + + align:start position:0% +five values like +this and because these energy levels are + + align:start position:0% +this and because these energy levels are + + + align:start position:0% +this and because these energy levels are +all split and I'll draw some now so that + + align:start position:0% +all split and I'll draw some now so that + + + align:start position:0% +all split and I'll draw some now so that +you get some feel what's going + + align:start position:0% +you get some feel what's going + + + align:start position:0% +you get some feel what's going +on see if I've got space to do it here + + align:start position:0% +on see if I've got space to do it here + + + align:start position:0% +on see if I've got space to do it here +we start out + + align:start position:0% + + + + align:start position:0% + +with n = 1 n = 2 Nal three this nals 1 + + align:start position:0% +with n = 1 n = 2 Nal three this nals 1 + + + align:start position:0% +with n = 1 n = 2 Nal three this nals 1 +will just be split to an N equals one + + align:start position:0% +will just be split to an N equals one + + + align:start position:0% +will just be split to an N equals one +level the N equals 2 will be split to + + align:start position:0% +level the N equals 2 will be split to + + + align:start position:0% +level the N equals 2 will be split to +three levels and the N equals three we + + align:start position:0% +three levels and the N equals three we + + + align:start position:0% +three levels and the N equals three we +split to five + + align:start position:0% + + + + align:start position:0% + +levels and each of these levels is going + + align:start position:0% +levels and each of these levels is going + + + align:start position:0% +levels and each of these levels is going +to have an energy Delta + + align:start position:0% +to have an energy Delta + + + align:start position:0% +to have an energy Delta +e between them which is given by this + + align:start position:0% +e between them which is given by this + + + align:start position:0% +e between them which is given by this +formula here and so by measuring the + + align:start position:0% +formula here and so by measuring the + + + align:start position:0% +formula here and so by measuring the +splitting we can measure the magnetic + + align:start position:0% +splitting we can measure the magnetic + + + align:start position:0% +splitting we can measure the magnetic +field because + + align:start position:0% +field because + + + align:start position:0% +field because +most of the stuff in here is just a + + align:start position:0% +most of the stuff in here is just a + + + align:start position:0% +most of the stuff in here is just a +constant we should know our beam + + align:start position:0% +constant we should know our beam + + + align:start position:0% +constant we should know our beam +velocity because we're the ones + + align:start position:0% +velocity because we're the ones + + + align:start position:0% +velocity because we're the ones +objecting neutral beam so the only thing + + align:start position:0% +objecting neutral beam so the only thing + + + align:start position:0% +objecting neutral beam so the only thing +we don't know is the size of the + + align:start position:0% +we don't know is the size of the + + + align:start position:0% +we don't know is the size of the +magnetic + + align:start position:0% +magnetic + + + align:start position:0% +magnetic +field so we could try and use uh so + + align:start position:0% +field so we could try and use uh so + + + align:start position:0% +field so we could try and use uh so +again this is still a neutral beam so + + align:start position:0% +again this is still a neutral beam so + + + align:start position:0% +again this is still a neutral beam so +we've got one electron so we could try + + align:start position:0% +we've got one electron so we could try + + + align:start position:0% +we've got one electron so we could try +and look at transitions from here down + + align:start position:0% +and look at transitions from here down + + + align:start position:0% +and look at transitions from here down +to + + align:start position:0% +to + + + align:start position:0% +to +here and there should be a triplet of + + align:start position:0% +here and there should be a triplet of + + + align:start position:0% +here and there should be a triplet of +transitions all coming out with slightly + + align:start position:0% +transitions all coming out with slightly + + + align:start position:0% +transitions all coming out with slightly +different energies what is the problem + + align:start position:0% +different energies what is the problem + + + align:start position:0% +different energies what is the problem +with using + + align:start position:0% +with using + + + align:start position:0% +with using +this oh first of all does anyone + + align:start position:0% +this oh first of all does anyone + + + align:start position:0% +this oh first of all does anyone +remember the name for this transition + + align:start position:0% +remember the name for this transition + + + align:start position:0% +remember the name for this transition +and what's the problem with using + + align:start position:0% + + + + align:start position:0% + +it is it a forbidden transition it's not + + align:start position:0% +it is it a forbidden transition it's not + + + align:start position:0% +it is it a forbidden transition it's not +forbidden but good + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% + + + + align:start position:0% + +hydrogen transition from the first + + align:start position:0% +hydrogen transition from the first + + + align:start position:0% +hydrogen transition from the first +excited state down to ground state is + + align:start position:0% +excited state down to ground state is + + + align:start position:0% +excited state down to ground state is +the Lyman Alpha + + align:start position:0% + + + + align:start position:0% + +what's the wavelength of the L + + align:start position:0% +what's the wavelength of the L + + + align:start position:0% +what's the wavelength of the L +Alpha yeah it's 121 + + align:start position:0% + + + + align:start position:0% + +Nom so this is what's called vacuum + + align:start position:0% +Nom so this is what's called vacuum + + + align:start position:0% +Nom so this is what's called vacuum +ultraviolet and the reason it's called + + align:start position:0% +ultraviolet and the reason it's called + + + align:start position:0% +ultraviolet and the reason it's called +vacuum ultraviolet is it only propagates + + align:start position:0% +vacuum ultraviolet is it only propagates + + + align:start position:0% +vacuum ultraviolet is it only propagates +in a vacuum so it's a real pain to deal + + align:start position:0% +in a vacuum so it's a real pain to deal + + + align:start position:0% +in a vacuum so it's a real pain to deal +with so we don't want to work with this + + align:start position:0% +with so we don't want to work with this + + + align:start position:0% +with so we don't want to work with this +transition here instead what we want to + + align:start position:0% +transition here instead what we want to + + + align:start position:0% +transition here instead what we want to +do is use a transition from nals 3 down + + align:start position:0% +do is use a transition from nals 3 down + + + align:start position:0% +do is use a transition from nals 3 down +to nals 2 what's the name of this + + align:start position:0% +to nals 2 what's the name of this + + + align:start position:0% +to nals 2 what's the name of this +transition + + align:start position:0% + + + + align:start position:0% + +yeah H alpha balber + + align:start position:0% + + + + align:start position:0% + +alpha and this is where the Forbidden + + align:start position:0% +alpha and this is where the Forbidden + + + align:start position:0% +alpha and this is where the Forbidden +transitions that were mentioned come in + + align:start position:0% +transitions that were mentioned come in + + + align:start position:0% +transitions that were mentioned come in +here so these have a angular momentum + + align:start position:0% +here so these have a angular momentum + + + align:start position:0% +here so these have a angular momentum +quantum number m m of 2 1 0 minus oneus + + align:start position:0% +quantum number m m of 2 1 0 minus oneus + + + align:start position:0% +quantum number m m of 2 1 0 minus oneus +2 1 Z minus one like this and the + + align:start position:0% +2 1 Z minus one like this and the + + + align:start position:0% +2 1 Z minus one like this and the +transit the uh selection rule for these + + align:start position:0% +transit the uh selection rule for these + + + align:start position:0% +transit the uh selection rule for these +that tells you whether this transition + + align:start position:0% +that tells you whether this transition + + + align:start position:0% +that tells you whether this transition +is forbidden or not is Delta m is equal + + align:start position:0% +is forbidden or not is Delta m is equal + + + align:start position:0% +is forbidden or not is Delta m is equal +to uh I got it written down + + align:start position:0% + + + + align:start position:0% + +here yeah zero and plus or minus + + align:start position:0% +here yeah zero and plus or minus + + + align:start position:0% +here yeah zero and plus or minus +one okay so From Any Given level here + + align:start position:0% +one okay so From Any Given level here + + + align:start position:0% +one okay so From Any Given level here +for this one for example the m equals z + + align:start position:0% +for this one for example the m equals z + + + align:start position:0% +for this one for example the m equals z +in the N equals 3 we can have a + + align:start position:0% +in the N equals 3 we can have a + + + align:start position:0% +in the N equals 3 we can have a +transition down to zero down to minus + + align:start position:0% +transition down to zero down to minus + + + align:start position:0% +transition down to zero down to minus +one and down to one we'll get a triple + + align:start position:0% +one and down to one we'll get a triple + + + align:start position:0% +one and down to one we'll get a triple +of lines from that we'll also get + + align:start position:0% +of lines from that we'll also get + + + align:start position:0% +of lines from that we'll also get +another set of lines you can see this + + align:start position:0% +another set of lines you can see this + + + align:start position:0% +another set of lines you can see this +starts to get quite complicated quite + + align:start position:0% +starts to get quite complicated quite + + + align:start position:0% +starts to get quite complicated quite +quickly like + + align:start position:0% +quickly like + + + align:start position:0% +quickly like +this there is no transition down to + + align:start position:0% +this there is no transition down to + + + align:start position:0% +this there is no transition down to +minus two because it doesn't exist and + + align:start position:0% +minus two because it doesn't exist and + + + align:start position:0% +minus two because it doesn't exist and +then + + align:start position:0% +then + + + align:start position:0% +then +finally uh we'll have well the minus two + + align:start position:0% +finally uh we'll have well the minus two + + + align:start position:0% +finally uh we'll have well the minus two +could guess can go to minus + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +and the m equals 1 can go down to uh m + + align:start position:0% + + + + align:start position:0% + +equals zero and m equal 1 I'm running + + align:start position:0% +equals zero and m equal 1 I'm running + + + align:start position:0% +equals zero and m equal 1 I'm running +out of + + align:start position:0% +out of + + + align:start position:0% +out of +colors and the m equals 2 can go down to + + align:start position:0% +colors and the m equals 2 can go down to + + + align:start position:0% +colors and the m equals 2 can go down to +the + + align:start position:0% +the + + + align:start position:0% +the +m f time so you see there's all sorts of + + align:start position:0% +m f time so you see there's all sorts of + + + align:start position:0% +m f time so you see there's all sorts of +different lines but you notice that + + align:start position:0% +different lines but you notice that + + + align:start position:0% +different lines but you notice that +their spacings of these levels are the + + align:start position:0% +their spacings of these levels are the + + + align:start position:0% +their spacings of these levels are the +same as the spacings of these no it's + + align:start position:0% +same as the spacings of these no it's + + + align:start position:0% +same as the spacings of these no it's +not because n is different yeah you're + + align:start position:0% +not because n is different yeah you're + + + align:start position:0% +not because n is different yeah you're +going to get clusters of different lines + + align:start position:0% +going to get clusters of different lines + + + align:start position:0% +going to get clusters of different lines +at slightly different energy so you need + + align:start position:0% +at slightly different energy so you need + + + align:start position:0% +at slightly different energy so you need +a very nice spectrometer be able to + + align:start position:0% +a very nice spectrometer be able to + + + align:start position:0% +a very nice spectrometer be able to +distinguish between these lines so as + + align:start position:0% +distinguish between these lines so as + + + align:start position:0% +distinguish between these lines so as +you increase the magnetic field the + + align:start position:0% +you increase the magnetic field the + + + align:start position:0% +you increase the magnetic field the +energy gap gets bigger and so you need a + + align:start position:0% +energy gap gets bigger and so you need a + + + align:start position:0% +energy gap gets bigger and so you need a +less and less nice Spectrum so um your + + align:start position:0% +less and less nice Spectrum so um your + + + align:start position:0% +less and less nice Spectrum so um your +resolution requirements go down for a + + align:start position:0% +resolution requirements go down for a + + + align:start position:0% +resolution requirements go down for a +bigger magnetic field but in general + + align:start position:0% +bigger magnetic field but in general + + + align:start position:0% +bigger magnetic field but in general +you're going to see a forest of light + + align:start position:0% +you're going to see a forest of light + + + align:start position:0% +you're going to see a forest of light +you're going to + + align:start position:0% +you're going to + + + align:start position:0% +you're going to +see instead of just your H Alpha line + + align:start position:0% +see instead of just your H Alpha line + + + align:start position:0% +see instead of just your H Alpha line +that you had originally you're going to + + align:start position:0% +that you had originally you're going to + + + align:start position:0% +that you had originally you're going to +get I'm not going to try and draw this + + align:start position:0% +get I'm not going to try and draw this + + + align:start position:0% +get I'm not going to try and draw this +accurately a set of lines like this and + + align:start position:0% +accurately a set of lines like this and + + + align:start position:0% +accurately a set of lines like this and +then you might get another line over up + + align:start position:0% +then you might get another line over up + + + align:start position:0% +then you might get another line over up +here and you might get another line down + + align:start position:0% +here and you might get another line down + + + align:start position:0% +here and you might get another line down +here and all sorts of things like that + + align:start position:0% +here and all sorts of things like that + + + align:start position:0% +here and all sorts of things like that +and other sets of triplets and dbls + + align:start position:0% +and other sets of triplets and dbls + + + align:start position:0% +and other sets of triplets and dbls +different + + align:start position:0% + + + + align:start position:0% + +places if that's not quite right it's + + align:start position:0% +places if that's not quite right it's + + + align:start position:0% +places if that's not quite right it's +not completely okay + + align:start position:0% + + + + align:start position:0% + +cool why are we bothering with this this + + align:start position:0% +cool why are we bothering with this this + + + align:start position:0% +cool why are we bothering with this this +looks an awful lot like Zan splitting + + align:start position:0% +looks an awful lot like Zan splitting + + + align:start position:0% +looks an awful lot like Zan splitting +couldn't we have just done Zan splitting + + align:start position:0% +couldn't we have just done Zan splitting + + + align:start position:0% +couldn't we have just done Zan splitting +okay so the main thing about this is + + align:start position:0% +okay so the main thing about this is + + + align:start position:0% +okay so the main thing about this is +this Delta e is much much larger than we + + align:start position:0% +this Delta e is much much larger than we + + + align:start position:0% +this Delta e is much much larger than we +get for + + align:start position:0% +get for + + + align:start position:0% +get for +Z + + align:start position:0% + + + + align:start position:0% + +by much much larger I mean about 10 + + align:start position:0% +by much much larger I mean about 10 + + + align:start position:0% +by much much larger I mean about 10 +times larger so it's much easier to + + align:start position:0% +times larger so it's much easier to + + + align:start position:0% +times larger so it's much easier to +distinguish between the lines and once + + align:start position:0% +distinguish between the lines and once + + + align:start position:0% +distinguish between the lines and once +again we can use our neutral beam that + + align:start position:0% +again we can use our neutral beam that + + + align:start position:0% +again we can use our neutral beam that +we already have to do this so this is + + align:start position:0% +we already have to do this so this is + + + align:start position:0% +we already have to do this so this is +very nice use of a neutral beam now we + + align:start position:0% +very nice use of a neutral beam now we + + + align:start position:0% +very nice use of a neutral beam now we +talked about with Zan before it's not + + align:start position:0% +talked about with Zan before it's not + + + align:start position:0% +talked about with Zan before it's not +actually super useful to be able to + + align:start position:0% +actually super useful to be able to + + + align:start position:0% +actually super useful to be able to +measure the straight for a magnetic + + align:start position:0% +measure the straight for a magnetic + + + align:start position:0% +measure the straight for a magnetic +field in a toac because we know what it + + align:start position:0% +field in a toac because we know what it + + + align:start position:0% +field in a toac because we know what it +is it's the toid magnetic field + + align:start position:0% +is it's the toid magnetic field + + + align:start position:0% +is it's the toid magnetic field +basically the poloidal magnetic field is + + align:start position:0% +basically the poloidal magnetic field is + + + align:start position:0% +basically the poloidal magnetic field is +very small so this is our condition that + + align:start position:0% +very small so this is our condition that + + + align:start position:0% +very small so this is our condition that +b poloidal is much much less than B + + align:start position:0% +b poloidal is much much less than B + + + align:start position:0% +b poloidal is much much less than B +thidal that we have in a toac um the + + align:start position:0% +thidal that we have in a toac um the + + + align:start position:0% +thidal that we have in a toac um the +nice thing about this is that each of + + align:start position:0% +nice thing about this is that each of + + + align:start position:0% +nice thing about this is that each of +these different transitions has a + + align:start position:0% +these different transitions has a + + + align:start position:0% +these different transitions has a +different polarization this is going + + align:start position:0% +different polarization this is going + + + align:start position:0% +different polarization this is going +back to what we were talking about + + align:start position:0% +back to what we were talking about + + + align:start position:0% +back to what we were talking about +before where we had these pi + + align:start position:0% +before where we had these pi + + + align:start position:0% +before where we had these pi +polarizations and sigma + + align:start position:0% +polarizations and sigma + + + align:start position:0% +polarizations and sigma +polarizations and I'm running out of + + align:start position:0% +polarizations and I'm running out of + + + align:start position:0% +polarizations and I'm running out of +room to draw it but if you go back to + + align:start position:0% +room to draw it but if you go back to + + + align:start position:0% +room to draw it but if you go back to +the notes that we had on Zan + + align:start position:0% +the notes that we had on Zan + + + align:start position:0% +the notes that we had on Zan +spectroscopy here + + align:start position:0% +spectroscopy here + + + align:start position:0% +spectroscopy here +this polarization for example will come + + align:start position:0% + + + + align:start position:0% + +out we've got some magnetic fields here + + align:start position:0% +out we've got some magnetic fields here + + + align:start position:0% +out we've got some magnetic fields here +which is the thidal field plus the the + + align:start position:0% +which is the thidal field plus the the + + + align:start position:0% +which is the thidal field plus the the +loyal field will have the P polarization + + align:start position:0% +loyal field will have the P polarization + + + align:start position:0% +loyal field will have the P polarization +coming out of the + + align:start position:0% + + + + align:start position:0% + +plasma perpendicular to be and we'll + + align:start position:0% +plasma perpendicular to be and we'll + + + align:start position:0% +plasma perpendicular to be and we'll +have the stigma polarizations coming + + align:start position:0% + + + + align:start position:0% + +out parallel to B so by having two + + align:start position:0% +out parallel to B so by having two + + + align:start position:0% +out parallel to B so by having two +spectrometers with two different + + align:start position:0% +spectrometers with two different + + + align:start position:0% +spectrometers with two different +polarizers Cross of each other and + + align:start position:0% +polarizers Cross of each other and + + + align:start position:0% +polarizers Cross of each other and +measuring the relative strength of these + + align:start position:0% +measuring the relative strength of these + + + align:start position:0% +measuring the relative strength of these +two lines you can actually determine the + + align:start position:0% +two lines you can actually determine the + + + align:start position:0% +two lines you can actually determine the +angle of the magnetic field and then + + align:start position:0% +angle of the magnetic field and then + + + align:start position:0% +angle of the magnetic field and then +from that you can work out the size of + + align:start position:0% +from that you can work out the size of + + + align:start position:0% +from that you can work out the size of +this bidal component + + align:start position:0% + + + + align:start position:0% + +and from the bidal component you can + + align:start position:0% +and from the bidal component you can + + + align:start position:0% +and from the bidal component you can +start to guess at distribution of + + align:start position:0% +start to guess at distribution of + + + align:start position:0% +start to guess at distribution of +current inside your toac which is very + + align:start position:0% +current inside your toac which is very + + + align:start position:0% +current inside your toac which is very +very important especially when we're + + align:start position:0% +very important especially when we're + + + align:start position:0% +very important especially when we're +doing things like bootstrap current + + align:start position:0% +doing things like bootstrap current + + + align:start position:0% +doing things like bootstrap current +where we need very specific current + + align:start position:0% +where we need very specific current + + + align:start position:0% +where we need very specific current +profiles in order to induce it so + + align:start position:0% +profiles in order to induce it so + + + align:start position:0% +profiles in order to induce it so +basically motional star effect here is + + align:start position:0% +basically motional star effect here is + + + align:start position:0% +basically motional star effect here is +very useful for + + align:start position:0% +very useful for + + + align:start position:0% +very useful for +magnetic + + align:start position:0% + + + + align:start position:0% + +reconstruction + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +yes so the Zan effect requires certain + + align:start position:0% +yes so the Zan effect requires certain + + + align:start position:0% +yes so the Zan effect requires certain +electronic configurations to actually + + align:start position:0% +electronic configurations to actually + + + align:start position:0% +electronic configurations to actually +occur and I believe that you don't get + + align:start position:0% +occur and I believe that you don't get + + + align:start position:0% +occur and I believe that you don't get +Zan splitting in hydrogen normally so + + align:start position:0% +Zan splitting in hydrogen normally so + + + align:start position:0% +Zan splitting in hydrogen normally so +this emotional star effect is therefore + + align:start position:0% +this emotional star effect is therefore + + + align:start position:0% +this emotional star effect is therefore +more more like more useful in that case + + align:start position:0% +more more like more useful in that case + + + align:start position:0% +more more like more useful in that case +yeah and this motional star effect is + + align:start position:0% +yeah and this motional star effect is + + + align:start position:0% +yeah and this motional star effect is +particularly big because we're talking + + align:start position:0% +particularly big because we're talking + + + align:start position:0% +particularly big because we're talking +about very fast moving neutral beam + + align:start position:0% +about very fast moving neutral beam + + + align:start position:0% +about very fast moving neutral beam +particles so or you know this this isn't + + align:start position:0% +particles so or you know this this isn't + + + align:start position:0% +particles so or you know this this isn't +useful in a plasma in just looking at + + align:start position:0% +useful in a plasma in just looking at + + + align:start position:0% +useful in a plasma in just looking at +the thermal ions because all these + + align:start position:0% +the thermal ions because all these + + + align:start position:0% +the thermal ions because all these +velocities are in different directions + + align:start position:0% +velocities are in different directions + + + align:start position:0% +velocities are in different directions +and they're relatively small so all that + + align:start position:0% +and they're relatively small so all that + + + align:start position:0% +and they're relatively small so all that +will give you is a broadening the point + + align:start position:0% +will give you is a broadening the point + + + align:start position:0% +will give you is a broadening the point +is that this V is large and All in One + + align:start position:0% +is that this V is large and All in One + + + align:start position:0% +is that this V is large and All in One +Direction so you get a big splitting and + + align:start position:0% +Direction so you get a big splitting and + + + align:start position:0% +Direction so you get a big splitting and +it consists every single particle is + + align:start position:0% +it consists every single particle is + + + align:start position:0% +it consists every single particle is +emitting light with the same Spectra and + + align:start position:0% +emitting light with the same Spectra and + + + align:start position:0% +emitting light with the same Spectra and +so you can actually stand a chance of + + align:start position:0% + + + + align:start position:0% + +measure any questions + + align:start position:0% + + + + align:start position:0% + +online all right you can have quarter of + + align:start position:0% +online all right you can have quarter of + + + align:start position:0% +online all right you can have quarter of +your H quarter of an hour of your lives + + align:start position:0% +your H quarter of an hour of your lives + + + align:start position:0% +your H quarter of an hour of your lives +back do whatever you want and Happy + + align:start position:0% + + + + align:start position:0% + +Thanksgiving \ No newline at end of file diff --git a/qhOVXxNXAug.txt b/qhOVXxNXAug.txt new file mode 100644 index 0000000000000000000000000000000000000000..bdedb5b0fade723cb7da8c9f4621996be0bd4a19 --- /dev/null +++ b/qhOVXxNXAug.txt @@ -0,0 +1,379 @@ +align:start position:0% + +okay now it's time to construct and + + align:start position:0% +okay now it's time to construct and + + + align:start position:0% +okay now it's time to construct and +pre-process the corpus so we'll start by + + align:start position:0% +pre-process the corpus so we'll start by + + + align:start position:0% +pre-process the corpus so we'll start by +loading the TM package with library of + + align:start position:0% +loading the TM package with library of + + + align:start position:0% +loading the TM package with library of +TM and now that we have done that we'll + + align:start position:0% +TM and now that we have done that we'll + + + align:start position:0% +TM and now that we have done that we'll +construct a variable called corpus using + + align:start position:0% +construct a variable called corpus using + + + align:start position:0% +construct a variable called corpus using +the corpus and vector source functions + + align:start position:0% +the corpus and vector source functions + + + align:start position:0% +the corpus and vector source functions +and passing in all of the emails in our + + align:start position:0% +and passing in all of the emails in our + + + align:start position:0% +and passing in all of the emails in our +data set which is emails dollar sign + + align:start position:0% +data set which is emails dollar sign + + + align:start position:0% +data set which is emails dollar sign +email okay so now that we've constructed + + align:start position:0% +email okay so now that we've constructed + + + align:start position:0% +email okay so now that we've constructed +the corpus we can output the first email + + align:start position:0% +the corpus we can output the first email + + + align:start position:0% +the corpus we can output the first email +in the corpus we'll start out by calling + + align:start position:0% +in the corpus we'll start out by calling + + + align:start position:0% +in the corpus we'll start out by calling +this to our wrap function to get it on + + align:start position:0% +this to our wrap function to get it on + + + align:start position:0% +this to our wrap function to get it on +multiple lines and then we can select + + align:start position:0% +multiple lines and then we can select + + + align:start position:0% +multiple lines and then we can select +the first element in the corpus using + + align:start position:0% +the first element in the corpus using + + + align:start position:0% +the first element in the corpus using +the double square bracket notation and + + align:start position:0% +the double square bracket notation and + + + align:start position:0% +the double square bracket notation and +selecting element 1 and we can see that + + align:start position:0% +selecting element 1 and we can see that + + + align:start position:0% +selecting element 1 and we can see that +this is exactly the same email that we + + align:start position:0% +this is exactly the same email that we + + + align:start position:0% +this is exactly the same email that we +saw originally so email about the + + align:start position:0% +saw originally so email about the + + + align:start position:0% +saw originally so email about the +working paper alright so now we're ready + + align:start position:0% +working paper alright so now we're ready + + + align:start position:0% +working paper alright so now we're ready +to pre-process the corpus using the TM + + align:start position:0% +to pre-process the corpus using the TM + + + align:start position:0% +to pre-process the corpus using the TM +map function + + align:start position:0% +map function + + + align:start position:0% +map function +so first we'll convert the corpus to + + align:start position:0% +so first we'll convert the corpus to + + + align:start position:0% +so first we'll convert the corpus to +lowercase using TM map and the two lower + + align:start position:0% +lowercase using TM map and the two lower + + + align:start position:0% +lowercase using TM map and the two lower +function still have corpus is equal to + + align:start position:0% +function still have corpus is equal to + + + align:start position:0% +function still have corpus is equal to +TM map of corpus and pass it along to + + align:start position:0% +TM map of corpus and pass it along to + + + align:start position:0% +TM map of corpus and pass it along to +lower alright and then we'll do the + + align:start position:0% +lower alright and then we'll do the + + + align:start position:0% +lower alright and then we'll do the +exact same thing except removing + + align:start position:0% +exact same thing except removing + + + align:start position:0% +exact same thing except removing +punctuation so I have corpus is equal to + + align:start position:0% +punctuation so I have corpus is equal to + + + align:start position:0% +punctuation so I have corpus is equal to +TM map of the corpus with the remove + + align:start position:0% +TM map of the corpus with the remove + + + align:start position:0% +TM map of the corpus with the remove +punctuation ok we'll remove the stop + + align:start position:0% +punctuation ok we'll remove the stop + + + align:start position:0% +punctuation ok we'll remove the stop +words with remove words function and + + align:start position:0% +words with remove words function and + + + align:start position:0% +words with remove words function and +we'll pass along to stop words of the + + align:start position:0% +we'll pass along to stop words of the + + + align:start position:0% +we'll pass along to stop words of the +English language as the words we want to + + align:start position:0% +English language as the words we want to + + + align:start position:0% +English language as the words we want to +remove and lastly we're going to send + + align:start position:0% +remove and lastly we're going to send + + + align:start position:0% +remove and lastly we're going to send +the document so if corpus is you put a + + align:start position:0% +the document so if corpus is you put a + + + align:start position:0% +the document so if corpus is you put a +TM map of corpus with the stem document + + align:start position:0% +TM map of corpus with the stem document + + + align:start position:0% +TM map of corpus with the stem document +function ok and now that we've gone + + align:start position:0% +function ok and now that we've gone + + + align:start position:0% +function ok and now that we've gone +through those for pre-processing steps + + align:start position:0% +through those for pre-processing steps + + + align:start position:0% +through those for pre-processing steps +we can take a second look at the first + + align:start position:0% +we can take a second look at the first + + + align:start position:0% +we can take a second look at the first +email in the corpus so again call STR + + align:start position:0% +email in the corpus so again call STR + + + align:start position:0% +email in the corpus so again call STR +wrap on corpus + + align:start position:0% +wrap on corpus + + + align:start position:0% +wrap on corpus +selecting the first email and now it + + align:start position:0% +selecting the first email and now it + + + align:start position:0% +selecting the first email and now it +looks quite a bit different let me come + + align:start position:0% +looks quite a bit different let me come + + + align:start position:0% +looks quite a bit different let me come +up to the top here it's a lot harder to + + align:start position:0% +up to the top here it's a lot harder to + + + align:start position:0% +up to the top here it's a lot harder to +read now that we removed all the stop + + align:start position:0% +read now that we removed all the stop + + + align:start position:0% +read now that we removed all the stop +words and punctuation and word stems but + + align:start position:0% +words and punctuation and word stems but + + + align:start position:0% +words and punctuation and word stems but +now the emails and this corpus are ready + + align:start position:0% +now the emails and this corpus are ready + + + align:start position:0% +now the emails and this corpus are ready +for our machine learning algorithms \ No newline at end of file diff --git a/qpdtzW8py0c.txt b/qpdtzW8py0c.txt new file mode 100644 index 0000000000000000000000000000000000000000..07c988e73d58e7cf494b49be89368f9c2bccc0ec --- /dev/null +++ b/qpdtzW8py0c.txt @@ -0,0 +1,2907 @@ +align:start position:0% + +Hello, I'm Mary Rudder from the Harvey + + align:start position:0% +Hello, I'm Mary Rudder from the Harvey + + + align:start position:0% +Hello, I'm Mary Rudder from the Harvey +Ken School in Charles Town and I teach + + align:start position:0% +Ken School in Charles Town and I teach + + + align:start position:0% +Ken School in Charles Town and I teach +kindergarten. Um, I use the Star + + align:start position:0% +kindergarten. Um, I use the Star + + + align:start position:0% +kindergarten. Um, I use the Star +Festival CD ROM as part of our unit on + + align:start position:0% +Festival CD ROM as part of our unit on + + + align:start position:0% +Festival CD ROM as part of our unit on +Japan and places in the world. I also + + align:start position:0% +Japan and places in the world. I also + + + align:start position:0% +Japan and places in the world. I also +use it as a connection between family + + align:start position:0% +use it as a connection between family + + + align:start position:0% +use it as a connection between family +life, um, family roots and just to make + + align:start position:0% +life, um, family roots and just to make + + + align:start position:0% +life, um, family roots and just to make +the adventure more real. We start our + + align:start position:0% +the adventure more real. We start our + + + align:start position:0% +the adventure more real. We start our +adventure on our airplane which the kids + + align:start position:0% +adventure on our airplane which the kids + + + align:start position:0% +adventure on our airplane which the kids +painted and designed and then we prepare + + align:start position:0% +painted and designed and then we prepare + + + align:start position:0% +painted and designed and then we prepare +for our trip by packing our suitcases + + align:start position:0% +for our trip by packing our suitcases + + + align:start position:0% +for our trip by packing our suitcases +which of course are made of paper since + + align:start position:0% +which of course are made of paper since + + + align:start position:0% +which of course are made of paper since +kindergarten is the paper capital of the + + align:start position:0% +kindergarten is the paper capital of the + + + align:start position:0% +kindergarten is the paper capital of the +world. Um, inside the suitcase is a + + align:start position:0% +world. Um, inside the suitcase is a + + + align:start position:0% +world. Um, inside the suitcase is a +plain piece of white paper and the + + align:start position:0% +plain piece of white paper and the + + + align:start position:0% +plain piece of white paper and the +children are asked to draw the things + + align:start position:0% +children are asked to draw the things + + + align:start position:0% +children are asked to draw the things +that they think they will need on their + + align:start position:0% +that they think they will need on their + + + align:start position:0% +that they think they will need on their +trip. And sometimes you get what they + + align:start position:0% +trip. And sometimes you get what they + + + align:start position:0% +trip. And sometimes you get what they +would need. Some children want to bring + + align:start position:0% +would need. Some children want to bring + + + align:start position:0% +would need. Some children want to bring +all the toys they own. And one of the + + align:start position:0% +all the toys they own. And one of the + + + align:start position:0% +all the toys they own. And one of the +boys this year wanted to bring an ice + + align:start position:0% +boys this year wanted to bring an ice + + + align:start position:0% +boys this year wanted to bring an ice +cream machine. Unfortunately, when he + + align:start position:0% +cream machine. Unfortunately, when he + + + align:start position:0% +cream machine. Unfortunately, when he +went through customs in Japan, they + + align:start position:0% +went through customs in Japan, they + + + align:start position:0% +went through customs in Japan, they +would not let him in. They made him take + + align:start position:0% +would not let him in. They made him take + + + align:start position:0% +would not let him in. They made him take +it out of his suitcase cuz I am the + + align:start position:0% +it out of his suitcase cuz I am the + + + align:start position:0% +it out of his suitcase cuz I am the +customs official. + + align:start position:0% +customs official. + + + align:start position:0% +customs official. +Um after we prepare we also + + align:start position:0% +Um after we prepare we also + + + align:start position:0% +Um after we prepare we also +have our airline tickets and since we + + align:start position:0% +have our airline tickets and since we + + + align:start position:0% +have our airline tickets and since we +will be traveling to several places on + + align:start position:0% +will be traveling to several places on + + + align:start position:0% +will be traveling to several places on +the earth on the world um there are + + align:start position:0% +the earth on the world um there are + + + align:start position:0% +the earth on the world um there are +several categories that it lists the + + align:start position:0% +several categories that it lists the + + + align:start position:0% +several categories that it lists the +places we we will be going. Tokyo is our + + align:start position:0% +places we we will be going. Tokyo is our + + + align:start position:0% +places we we will be going. Tokyo is our +first stop although our trip will bring + + align:start position:0% +first stop although our trip will bring + + + align:start position:0% +first stop although our trip will bring +us all the way to Haratska which is + + align:start position:0% +us all the way to Haratska which is + + + align:start position:0% +us all the way to Haratska which is +where the star festival takes place. Um + + align:start position:0% +where the star festival takes place. Um + + + align:start position:0% +where the star festival takes place. Um +the children have a ticket in their + + align:start position:0% +the children have a ticket in their + + + align:start position:0% +the children have a ticket in their +boarding pass and quite a few children + + align:start position:0% +boarding pass and quite a few children + + + align:start position:0% +boarding pass and quite a few children +real understand what a boarding pass is. + + align:start position:0% +real understand what a boarding pass is. + + + align:start position:0% +real understand what a boarding pass is. +So when they receive this they thought + + align:start position:0% +So when they receive this they thought + + + align:start position:0% +So when they receive this they thought +the trip was almost real. A few of the + + align:start position:0% +the trip was almost real. A few of the + + + align:start position:0% +the trip was almost real. A few of the +children went home and said I'm going to + + align:start position:0% +children went home and said I'm going to + + + align:start position:0% +children went home and said I'm going to +Japan tomorrow but you don't need to + + align:start position:0% +Japan tomorrow but you don't need to + + + align:start position:0% +Japan tomorrow but you don't need to +worry mom cuz I'm going to be home by + + align:start position:0% +worry mom cuz I'm going to be home by + + + align:start position:0% +worry mom cuz I'm going to be home by +8:00 tonight. So I also issued them a + + align:start position:0% +8:00 tonight. So I also issued them a + + + align:start position:0% +8:00 tonight. So I also issued them a +passport. Put their picture in it. Had + + align:start position:0% +passport. Put their picture in it. Had + + + align:start position:0% +passport. Put their picture in it. Had +them sign their name. checked to see if + + align:start position:0% +them sign their name. checked to see if + + + align:start position:0% +them sign their name. checked to see if +they knew their address because this is + + align:start position:0% +they knew their address because this is + + + align:start position:0% +they knew their address because this is +an important fact u fact toy the + + align:start position:0% +an important fact u fact toy the + + + align:start position:0% +an important fact u fact toy the +kindergarten children are expected to + + align:start position:0% +kindergarten children are expected to + + + align:start position:0% +kindergarten children are expected to +learn a few didn't know went home and + + align:start position:0% +learn a few didn't know went home and + + + align:start position:0% +learn a few didn't know went home and +found out their birth date again a few + + align:start position:0% +found out their birth date again a few + + + align:start position:0% +found out their birth date again a few +didn't know left a space on the back for + + align:start position:0% +didn't know left a space on the back for + + + align:start position:0% +didn't know left a space on the back for +the stamps for when they go through + + align:start position:0% +the stamps for when they go through + + + align:start position:0% +the stamps for when they go through +customs so as you can see we are in + + align:start position:0% +customs so as you can see we are in + + + align:start position:0% +customs so as you can see we are in +Japan so in the afternoon because it's + + align:start position:0% +Japan so in the afternoon because it's + + + align:start position:0% +Japan so in the afternoon because it's +an 18-hour flight from + + align:start position:0% +an 18-hour flight from + + + align:start position:0% +an 18-hour flight from +Boston we board the ship we board the + + align:start position:0% +Boston we board the ship we board the + + + align:start position:0% +Boston we board the ship we board the +airship just before we're leaving and + + align:start position:0% +airship just before we're leaving and + + + align:start position:0% +airship just before we're leaving and +for the day. And I collect their tickets + + align:start position:0% +for the day. And I collect their tickets + + + align:start position:0% +for the day. And I collect their tickets +and their suitcases and stow them under + + align:start position:0% +and their suitcases and stow them under + + + align:start position:0% +and their suitcases and stow them under +board and behind the airplane is seats. + + align:start position:0% +board and behind the airplane is seats. + + + align:start position:0% +board and behind the airplane is seats. +And they sit in + + align:start position:0% +And they sit in + + + align:start position:0% +And they sit in +rows just as they would in a airplane. + + align:start position:0% +rows just as they would in a airplane. + + + align:start position:0% +rows just as they would in a airplane. +And they say, "Oh, uh, when are we going + + align:start position:0% +And they say, "Oh, uh, when are we going + + + align:start position:0% +And they say, "Oh, uh, when are we going +to be in Japan?" And I I will tell them, + + align:start position:0% +to be in Japan?" And I I will tell them, + + + align:start position:0% +to be in Japan?" And I I will tell them, +"You have to go home tonight. Go to bed + + align:start position:0% +"You have to go home tonight. Go to bed + + + align:start position:0% +"You have to go home tonight. Go to bed +in your own bed. And when you come back + + align:start position:0% +in your own bed. And when you come back + + + align:start position:0% +in your own bed. And when you come back +in the morning, we will be almost in + + align:start position:0% +in the morning, we will be almost in + + + align:start position:0% +in the morning, we will be almost in +Japan. So they come in the following + + align:start position:0% +Japan. So they come in the following + + + align:start position:0% +Japan. So they come in the following +morning. And when they came in, the + + align:start position:0% +morning. And when they came in, the + + + align:start position:0% +morning. And when they came in, the +Japanese house is up. So we'll talk + + align:start position:0% +Japanese house is up. So we'll talk + + + align:start position:0% +Japanese house is up. So we'll talk +about that in a few minutes. Before we + + align:start position:0% +about that in a few minutes. Before we + + + align:start position:0% +about that in a few minutes. Before we +start our trip, I want the children to + + align:start position:0% +start our trip, I want the children to + + + align:start position:0% +start our trip, I want the children to +know where in the world they are and + + align:start position:0% +know where in the world they are and + + + align:start position:0% +know where in the world they are and +where they've come from. So we make a + + align:start position:0% +where they've come from. So we make a + + + align:start position:0% +where they've come from. So we make a +big mural map, which they help paint. Of + + align:start position:0% +big mural map, which they help paint. Of + + + align:start position:0% +big mural map, which they help paint. Of +course, you will notice that some of the + + align:start position:0% +course, you will notice that some of the + + + align:start position:0% +course, you will notice that some of the +continents aren't quite correct because + + align:start position:0% +continents aren't quite correct because + + + align:start position:0% +continents aren't quite correct because +when they get the paint in their hand, + + align:start position:0% +when they get the paint in their hand, + + + align:start position:0% +when they get the paint in their hand, +they tend to start painting areas that + + align:start position:0% +they tend to start painting areas that + + + align:start position:0% +they tend to start painting areas that +should be water and end up to be land + + align:start position:0% +should be water and end up to be land + + + align:start position:0% +should be water and end up to be land +and land that should be water or land + + align:start position:0% +and land that should be water or land + + + align:start position:0% +and land that should be water or land +that ends up to be water. So, but it has + + align:start position:0% +that ends up to be water. So, but it has + + + align:start position:0% +that ends up to be water. So, but it has +a general feeling for it. And I send + + align:start position:0% +a general feeling for it. And I send + + + align:start position:0% +a general feeling for it. And I send +home a + + align:start position:0% +home a + + + align:start position:0% +home a +questionnaire asking the parents because + + align:start position:0% +questionnaire asking the parents because + + + align:start position:0% +questionnaire asking the parents because +most of the children in the class come + + align:start position:0% +most of the children in the class come + + + align:start position:0% +most of the children in the class come +from other countries. In fact, just + + align:start position:0% +from other countries. In fact, just + + + align:start position:0% +from other countries. In fact, just +about everybody in America comes from + + align:start position:0% +about everybody in America comes from + + + align:start position:0% +about everybody in America comes from +another country if you trace back far + + align:start position:0% +another country if you trace back far + + + align:start position:0% +another country if you trace back far +enough. And they are asked just to write + + align:start position:0% +enough. And they are asked just to write + + + align:start position:0% +enough. And they are asked just to write +the child's name and if you have I + + align:start position:0% +the child's name and if you have I + + + align:start position:0% +the child's name and if you have I +mentioned mom, dad, grandparents, what + + align:start position:0% +mentioned mom, dad, grandparents, what + + + align:start position:0% +mentioned mom, dad, grandparents, what +countries they come from. And when they + + align:start position:0% +countries they come from. And when they + + + align:start position:0% +countries they come from. And when they +come in, I've already used the same + + align:start position:0% +come in, I've already used the same + + + align:start position:0% +come in, I've already used the same +pictures that we have on the passports + + align:start position:0% +pictures that we have on the passports + + + align:start position:0% +pictures that we have on the passports +to make a little um card which will + + align:start position:0% +to make a little um card which will + + + align:start position:0% +to make a little um card which will +mount on our map with a line that will + + align:start position:0% +mount on our map with a line that will + + + align:start position:0% +mount on our map with a line that will +go from the girl's name or boy's name to + + align:start position:0% +go from the girl's name or boy's name to + + + align:start position:0% +go from the girl's name or boy's name to +Boston to wherever they came from. So + + align:start position:0% +Boston to wherever they came from. So + + + align:start position:0% +Boston to wherever they came from. So +the children will actually be able to + + align:start position:0% +the children will actually be able to + + + align:start position:0% +the children will actually be able to +see where in the world their family came + + align:start position:0% +see where in the world their family came + + + align:start position:0% +see where in the world their family came +from. And it's quite interesting and + + align:start position:0% +from. And it's quite interesting and + + + align:start position:0% +from. And it's quite interesting and +they become very proud. In fact, the + + align:start position:0% +they become very proud. In fact, the + + + align:start position:0% +they become very proud. In fact, the +parents came in when they saw the map up + + align:start position:0% +parents came in when they saw the map up + + + align:start position:0% +parents came in when they saw the map up +and said, "Oh, this is where I come + + align:start position:0% +and said, "Oh, this is where I come + + + align:start position:0% +and said, "Oh, this is where I come +from. This is so they didn't know I was + + align:start position:0% +from. This is so they didn't know I was + + + align:start position:0% +from. This is so they didn't know I was +going to ask them the question." So, + + align:start position:0% +going to ask them the question." So, + + + align:start position:0% +going to ask them the question." So, +they'll I think they'll really be + + align:start position:0% +they'll I think they'll really be + + + align:start position:0% +they'll I think they'll really be +thrilled when they see their kids up + + align:start position:0% +thrilled when they see their kids up + + + align:start position:0% +thrilled when they see their kids up +with the name connected. I think it's + + align:start position:0% +with the name connected. I think it's + + + align:start position:0% +with the name connected. I think it's +just important because it gives them a + + align:start position:0% +just important because it gives them a + + + align:start position:0% +just important because it gives them a +sense of, you know, where where they + + align:start position:0% +sense of, you know, where where they + + + align:start position:0% +sense of, you know, where where they +came from and it also sort of gives + + align:start position:0% +came from and it also sort of gives + + + align:start position:0% +came from and it also sort of gives +value to their background. It was + + align:start position:0% +value to their background. It was + + + align:start position:0% +value to their background. It was +interesting that I sent home because we + + align:start position:0% +interesting that I sent home because we + + + align:start position:0% +interesting that I sent home because we +will be doing this paper. Um, and we + + align:start position:0% +will be doing this paper. Um, and we + + + align:start position:0% +will be doing this paper. Um, and we +will be doing a family tree, but I + + align:start position:0% +will be doing a family tree, but I + + + align:start position:0% +will be doing a family tree, but I +didn't ask for a family tree. One of the + + align:start position:0% +didn't ask for a family tree. One of the + + + align:start position:0% +didn't ask for a family tree. One of the +kids came back with it all written on + + align:start position:0% +kids came back with it all written on + + + align:start position:0% +kids came back with it all written on +the back of the paper. So, I thought + + align:start position:0% +the back of the paper. So, I thought + + + align:start position:0% +the back of the paper. So, I thought +this is perfect because when we start + + align:start position:0% +this is perfect because when we start + + + align:start position:0% +this is perfect because when we start +looking at Shagaru's family tree and we + + align:start position:0% +looking at Shagaru's family tree and we + + + align:start position:0% +looking at Shagaru's family tree and we +start doing our own here, Juan has his + + align:start position:0% +start doing our own here, Juan has his + + + align:start position:0% +start doing our own here, Juan has his +all done. Only we'll probably do it on a + + align:start position:0% +all done. Only we'll probably do it on a + + + align:start position:0% +all done. Only we'll probably do it on a +bigger piece of drawing paper so you can + + align:start position:0% +bigger piece of drawing paper so you can + + + align:start position:0% +bigger piece of drawing paper so you can +see it and I'll have him script the + + align:start position:0% +see it and I'll have him script the + + + align:start position:0% +see it and I'll have him script the +words. So I think that um it's + + align:start position:0% +words. So I think that um it's + + + align:start position:0% +words. So I think that um it's +interesting the things you come out with + + align:start position:0% +interesting the things you come out with + + + align:start position:0% +interesting the things you come out with +and the things that come out of the + + align:start position:0% +and the things that come out of the + + + align:start position:0% +and the things that come out of the +study + + align:start position:0% +study + + + align:start position:0% +study +um + + align:start position:0% +um + + + align:start position:0% +um +because um I want to go to Haratzka + + align:start position:0% +because um I want to go to Haratzka + + + align:start position:0% +because um I want to go to Haratzka +because part of our adventure in Japan + + align:start position:0% +because part of our adventure in Japan + + + align:start position:0% +because part of our adventure in Japan +is the big festival and what we will be + + align:start position:0% +is the big festival and what we will be + + + align:start position:0% +is the big festival and what we will be +doing as we travel with Shagarro through + + align:start position:0% +doing as we travel with Shagarro through + + + align:start position:0% +doing as we travel with Shagarro through +the different points going to the um + + align:start position:0% +the different points going to the um + + + align:start position:0% +the different points going to the um +train station or from the train station + + align:start position:0% +train station or from the train station + + + align:start position:0% +train station or from the train station +on the bus looking to see how it's the + + align:start position:0% +on the bus looking to see how it's the + + + align:start position:0% +on the bus looking to see how it's the +same as what they're used to or how it's + + align:start position:0% +same as what they're used to or how it's + + + align:start position:0% +same as what they're used to or how it's +different from what they know. They were + + align:start position:0% +different from what they know. They were + + + align:start position:0% +different from what they know. They were +thrilled to see the subway station, the + + align:start position:0% +thrilled to see the subway station, the + + + align:start position:0% +thrilled to see the subway station, the +train station, because they noticed + + align:start position:0% +train station, because they noticed + + + align:start position:0% +train station, because they noticed +right away it didn't look like a train + + align:start position:0% +right away it didn't look like a train + + + align:start position:0% +right away it didn't look like a train +station that they are familiar with and + + align:start position:0% +station that they are familiar with and + + + align:start position:0% +station that they are familiar with and +um they could see the little shops in + + align:start position:0% +um they could see the little shops in + + + align:start position:0% +um they could see the little shops in +the background. So, they were, "Wow, + + align:start position:0% +the background. So, they were, "Wow, + + + align:start position:0% +the background. So, they were, "Wow, +that's really pretty." So, I think + + align:start position:0% +that's really pretty." So, I think + + + align:start position:0% +that's really pretty." So, I think +that's um interesting that now they're + + align:start position:0% +that's um interesting that now they're + + + align:start position:0% +that's um interesting that now they're +thinking of what they know and they're + + align:start position:0% +thinking of what they know and they're + + + align:start position:0% +thinking of what they know and they're +learning something different. Um going + + align:start position:0% +learning something different. Um going + + + align:start position:0% +learning something different. Um going +to bring you over to our house. + + align:start position:0% + + + + align:start position:0% + +And the bell's going + + align:start position:0% + + + + align:start position:0% + +to I should sit on the floor, but I + + align:start position:0% +to I should sit on the floor, but I + + + align:start position:0% +to I should sit on the floor, but I +won't cuz I'll never get up + + align:start position:0% +won't cuz I'll never get up + + + align:start position:0% +won't cuz I'll never get up +again. Um, this is + + align:start position:0% +again. Um, this is + + + align:start position:0% +again. Um, this is +Haruku and she's named after a little + + align:start position:0% +Haruku and she's named after a little + + + align:start position:0% +Haruku and she's named after a little +girl I met in Japan when I went on a + + align:start position:0% +girl I met in Japan when I went on a + + + align:start position:0% +girl I met in Japan when I went on a +visit. And so when I came back, I + + align:start position:0% +visit. And so when I came back, I + + + align:start position:0% +visit. And so when I came back, I +thought kids like to relate to other + + align:start position:0% +thought kids like to relate to other + + + align:start position:0% +thought kids like to relate to other +kids. Um, and before I introduce Shagaru + + align:start position:0% +kids. Um, and before I introduce Shagaru + + + align:start position:0% +kids. Um, and before I introduce Shagaru +on the + + align:start position:0% +on the + + + align:start position:0% +on the +um + + align:start position:0% +um + + + align:start position:0% +um +CD, uh, Heruku introduces her + + align:start position:0% +CD, uh, Heruku introduces her + + + align:start position:0% +CD, uh, Heruku introduces her +grandmother's house because I don't want + + align:start position:0% +grandmother's house because I don't want + + + align:start position:0% +grandmother's house because I don't want +the children thinking that the every + + align:start position:0% +the children thinking that the every + + + align:start position:0% +the children thinking that the every +child in Japan lives in a house that's a + + align:start position:0% +child in Japan lives in a house that's a + + + align:start position:0% +child in Japan lives in a house that's a +traditional Japanese style house that + + align:start position:0% +traditional Japanese style house that + + + align:start position:0% +traditional Japanese style house that +most of the children when they talk to + + align:start position:0% +most of the children when they talk to + + + align:start position:0% +most of the children when they talk to +them would probably live in an + + align:start position:0% +them would probably live in an + + + align:start position:0% +them would probably live in an +apartment. U, but they might they would + + align:start position:0% +apartment. U, but they might they would + + + align:start position:0% +apartment. U, but they might they would +probably have a tatami mat on the floor + + align:start position:0% +probably have a tatami mat on the floor + + + align:start position:0% +probably have a tatami mat on the floor +and they might have the kadatu. um at + + align:start position:0% +and they might have the kadatu. um at + + + align:start position:0% +and they might have the kadatu. um at +their table or they might have a western + + align:start position:0% +their table or they might have a western + + + align:start position:0% +their table or they might have a western +table. So I think it's important that + + align:start position:0% +table. So I think it's important that + + + align:start position:0% +table. So I think it's important that +they know some of the things that um the + + align:start position:0% +they know some of the things that um the + + + align:start position:0% +they know some of the things that um the +the children in Japan are doing now. In + + align:start position:0% +the children in Japan are doing now. In + + + align:start position:0% +the children in Japan are doing now. In +fact, we have Japanese eels which is + + align:start position:0% +fact, we have Japanese eels which is + + + align:start position:0% +fact, we have Japanese eels which is +really a great great deal of fun. + + align:start position:0% +really a great great deal of fun. + + + align:start position:0% +really a great great deal of fun. +They're first graders, but they uh are + + align:start position:0% +They're first graders, but they uh are + + + align:start position:0% +They're first graders, but they uh are +kind enough to write to us. I show um + + align:start position:0% +kind enough to write to us. I show um + + + align:start position:0% +kind enough to write to us. I show um +Haku Haku in her regular clothes, but I + + align:start position:0% +Haku Haku in her regular clothes, but I + + + align:start position:0% +Haku Haku in her regular clothes, but I +have this little angel that was sitting + + align:start position:0% +have this little angel that was sitting + + + align:start position:0% +have this little angel that was sitting +up here and the kids all said, "What is + + align:start position:0% +up here and the kids all said, "What is + + + align:start position:0% +up here and the kids all said, "What is +that? What is that?" And then they said, + + align:start position:0% +that? What is that?" And then they said, + + + align:start position:0% +that? What is that?" And then they said, +"She has wings. She has wings." So I + + align:start position:0% +"She has wings. She has wings." So I + + + align:start position:0% +"She has wings. She has wings." So I +said, "Oh, what do you think this is?" + + align:start position:0% +said, "Oh, what do you think this is?" + + + align:start position:0% +said, "Oh, what do you think this is?" +And they recognized right away she's an + + align:start position:0% +And they recognized right away she's an + + + align:start position:0% +And they recognized right away she's an +angel. And I said, "Why would I want to + + align:start position:0% +angel. And I said, "Why would I want to + + + align:start position:0% +angel. And I said, "Why would I want to +have her around?" And oh, she's good + + align:start position:0% +have her around?" And oh, she's good + + + align:start position:0% +have her around?" And oh, she's good +luck. And I said, "But what's she + + align:start position:0% +luck. And I said, "But what's she + + + align:start position:0% +luck. And I said, "But what's she +wearing?" And we talked about she has + + align:start position:0% +wearing?" And we talked about she has + + + align:start position:0% +wearing?" And we talked about she has +the kimono on and she has the Gita + + align:start position:0% +the kimono on and she has the Gita + + + align:start position:0% +the kimono on and she has the Gita +shoes. So, it's sort of like a a tie + + align:start position:0% +shoes. So, it's sort of like a a tie + + + align:start position:0% +shoes. So, it's sort of like a a tie +between the old and the the new. And I + + align:start position:0% +between the old and the the new. And I + + + align:start position:0% +between the old and the the new. And I +think the CD ROM does that a lot when + + align:start position:0% +think the CD ROM does that a lot when + + + align:start position:0% +think the CD ROM does that a lot when +you see the older pictures and um you + + align:start position:0% +you see the older pictures and um you + + + align:start position:0% +you see the older pictures and um you +know the festival dress. Uh you know, I + + align:start position:0% +know the festival dress. Uh you know, I + + + align:start position:0% +know the festival dress. Uh you know, I +think it's important for them to + + align:start position:0% +think it's important for them to + + + align:start position:0% +think it's important for them to +recognize it. Um I tie in a lot of + + align:start position:0% +recognize it. Um I tie in a lot of + + + align:start position:0% +recognize it. Um I tie in a lot of +literature and I introduced the story by + + align:start position:0% +literature and I introduced the story by + + + align:start position:0% +literature and I introduced the story by +saying it's her + + align:start position:0% +saying it's her + + + align:start position:0% +saying it's her +favorite. So they think this is great if + + align:start position:0% +favorite. So they think this is great if + + + align:start position:0% +favorite. So they think this is great if +she liked this story and they sit with + + align:start position:0% +she liked this story and they sit with + + + align:start position:0% +she liked this story and they sit with +her after the story is read and um we'll + + align:start position:0% +her after the story is read and um we'll + + + align:start position:0% +her after the story is read and um we'll +reread it or go through the pages + + align:start position:0% +reread it or go through the pages + + + align:start position:0% +reread it or go through the pages +together or they'll all sit around the + + align:start position:0% +together or they'll all sit around the + + + align:start position:0% +together or they'll all sit around the +table and try to oh look at the pictures + + align:start position:0% +table and try to oh look at the pictures + + + align:start position:0% +table and try to oh look at the pictures +and talk to her. They were we had our + + align:start position:0% +and talk to her. They were we had our + + + align:start position:0% +and talk to her. They were we had our +friends in and we were singing songs + + align:start position:0% +friends in and we were singing songs + + + align:start position:0% +friends in and we were singing songs +together and they were making her hands + + align:start position:0% +together and they were making her hands + + + align:start position:0% +together and they were making her hands +clap because they wanted her to you know + + align:start position:0% +clap because they wanted her to you know + + + align:start position:0% +clap because they wanted her to you know +while we're doing we're clapping they + + align:start position:0% +while we're doing we're clapping they + + + align:start position:0% +while we're doing we're clapping they +wanted her to clap so they were like + + align:start position:0% +wanted her to clap so they were like + + + align:start position:0% +wanted her to clap so they were like +really including her as part of the + + align:start position:0% +really including her as part of the + + + align:start position:0% +really including her as part of the +classroom. I think it's important for + + align:start position:0% +classroom. I think it's important for + + + align:start position:0% +classroom. I think it's important for +the children to really become involved + + align:start position:0% +the children to really become involved + + + align:start position:0% +the children to really become involved +in things to make it important to them. + + align:start position:0% +in things to make it important to them. + + + align:start position:0% +in things to make it important to them. +Um we and I told them today they noticed + + align:start position:0% +Um we and I told them today they noticed + + + align:start position:0% +Um we and I told them today they noticed +the festival decorations on the uh + + align:start position:0% +the festival decorations on the uh + + + align:start position:0% +the festival decorations on the uh +opening screen and on some of the + + align:start position:0% +opening screen and on some of the + + + align:start position:0% +opening screen and on some of the +pictures that they saw and they said, + + align:start position:0% +pictures that they saw and they said, + + + align:start position:0% +pictures that they saw and they said, +"Oh, look at that." Uh especially the + + align:start position:0% +"Oh, look at that." Uh especially the + + + align:start position:0% +"Oh, look at that." Uh especially the +dragon. Look at the dragon. I said, "Oh, + + align:start position:0% +dragon. Look at the dragon. I said, "Oh, + + + align:start position:0% +dragon. Look at the dragon. I said, "Oh, +that's part of the festival." And we're + + align:start position:0% +that's part of the festival." And we're + + + align:start position:0% +that's part of the festival." And we're +traveling on this train to go to + + align:start position:0% +traveling on this train to go to + + + align:start position:0% +traveling on this train to go to +Haratska because we're going to be part + + align:start position:0% +Haratska because we're going to be part + + + align:start position:0% +Haratska because we're going to be part +of the festival. And we will plan at the + + align:start position:0% +of the festival. And we will plan at the + + + align:start position:0% +of the festival. And we will plan at the +end of uh two weeks of reading stories + + align:start position:0% +end of uh two weeks of reading stories + + + align:start position:0% +end of uh two weeks of reading stories +about Japan. True. And mostly folk a lot + + align:start position:0% +about Japan. True. And mostly folk a lot + + + align:start position:0% +about Japan. True. And mostly folk a lot +of folk tales. They are it allows them + + align:start position:0% +of folk tales. They are it allows them + + + align:start position:0% +of folk tales. They are it allows them +to process the story, tell what it's + + align:start position:0% +to process the story, tell what it's + + + align:start position:0% +to process the story, tell what it's +about. They pick out their favorite + + align:start position:0% +about. They pick out their favorite + + + align:start position:0% +about. They pick out their favorite +part. They read it. And um they thrilled + + align:start position:0% +part. They read it. And um they thrilled + + + align:start position:0% +part. They read it. And um they thrilled +me today. They read they they read the + + align:start position:0% +me today. They read they they read the + + + align:start position:0% +me today. They read they they read the +um wise old woman. And it sort of + + align:start position:0% +um wise old woman. And it sort of + + + align:start position:0% +um wise old woman. And it sort of +teaches why um the it's so important to + + align:start position:0% +teaches why um the it's so important to + + + align:start position:0% +teaches why um the it's so important to +respect elderly. And they took their + + align:start position:0% +respect elderly. And they took their + + + align:start position:0% +respect elderly. And they took their +favorite part and then they all stood + + align:start position:0% +favorite part and then they all stood + + + align:start position:0% +favorite part and then they all stood +and they started to write all the + + align:start position:0% +and they started to write all the + + + align:start position:0% +and they started to write all the +they're sounding out their words which + + align:start position:0% +they're sounding out their words which + + + align:start position:0% +they're sounding out their words which +is we're doing writers workshop. So this + + align:start position:0% +is we're doing writers workshop. So this + + + align:start position:0% +is we're doing writers workshop. So this +is like a big thing. I was so proud of + + align:start position:0% +is like a big thing. I was so proud of + + + align:start position:0% +is like a big thing. I was so proud of +them and they're going, "Oh, I got + + align:start position:0% +them and they're going, "Oh, I got + + + align:start position:0% +them and they're going, "Oh, I got +this." And they could read it. So I + + align:start position:0% +this." And they could read it. So I + + + align:start position:0% +this." And they could read it. So I +think it's um you know even though we're + + align:start position:0% +think it's um you know even though we're + + + align:start position:0% +think it's um you know even though we're +doing Japan, we're still doing language + + align:start position:0% +doing Japan, we're still doing language + + + align:start position:0% +doing Japan, we're still doing language +arts. We're still doing writing. + + align:start position:0% +arts. We're still doing writing. + + + align:start position:0% +arts. We're still doing writing. +So um I try to keep that connection and + + align:start position:0% +So um I try to keep that connection and + + + align:start position:0% +So um I try to keep that connection and +keep it tied in. So I told them that the + + align:start position:0% +keep it tied in. So I told them that the + + + align:start position:0% +keep it tied in. So I told them that the +festival we will be having a festival + + align:start position:0% +festival we will be having a festival + + + align:start position:0% +festival we will be having a festival +and we will need to do all the + + align:start position:0% +and we will need to do all the + + + align:start position:0% +and we will need to do all the +decorations just like they see in the + + align:start position:0% +decorations just like they see in the + + + align:start position:0% +decorations just like they see in the +movie and um or film and that we will be + + align:start position:0% +movie and um or film and that we will be + + + align:start position:0% +movie and um or film and that we will be +inviting our pals down the hall to come + + align:start position:0% +inviting our pals down the hall to come + + + align:start position:0% +inviting our pals down the hall to come +in and partake of all the festivities. + + align:start position:0% +in and partake of all the festivities. + + + align:start position:0% +in and partake of all the festivities. +And I said um because I knew I didn't + + align:start position:0% +And I said um because I knew I didn't + + + align:start position:0% +And I said um because I knew I didn't +want to have five kindergarten groups + + align:start position:0% +want to have five kindergarten groups + + + align:start position:0% +want to have five kindergarten groups +all in here at once. I said, you know, + + align:start position:0% +all in here at once. I said, you know, + + + align:start position:0% +all in here at once. I said, you know, +it takes a few days, so we'll probably + + align:start position:0% +it takes a few days, so we'll probably + + + align:start position:0% +it takes a few days, so we'll probably +have it several days with one class in, + + align:start position:0% +have it several days with one class in, + + + align:start position:0% +have it several days with one class in, +you know, each sitting. So, they were, + + align:start position:0% +you know, each sitting. So, they were, + + + align:start position:0% +you know, each sitting. So, they were, +oh, okay, we're ready. So, I think + + align:start position:0% +oh, okay, we're ready. So, I think + + + align:start position:0% +oh, okay, we're ready. So, I think +they're u I think this is really going + + align:start position:0% +they're u I think this is really going + + + align:start position:0% +they're u I think this is really going +to be a great adventure. All the past + + align:start position:0% +to be a great adventure. All the past + + + align:start position:0% +to be a great adventure. All the past +years I've done it, it's been a learning + + align:start position:0% +years I've done it, it's been a learning + + + align:start position:0% +years I've done it, it's been a learning +experience for the children and for + + align:start position:0% +experience for the children and for + + + align:start position:0% +experience for the children and for +myself. They always find a new angle or + + align:start position:0% +myself. They always find a new angle or + + + align:start position:0% +myself. They always find a new angle or +a different part to um key in on. And + + align:start position:0% +a different part to um key in on. And + + + align:start position:0% +a different part to um key in on. And +this especially this class, I think + + align:start position:0% +this especially this class, I think + + + align:start position:0% +this especially this class, I think +they're really keyed in on just they + + align:start position:0% +they're really keyed in on just they + + + align:start position:0% +they're really keyed in on just they +really think they're there. They're + + align:start position:0% +really think they're there. They're + + + align:start position:0% +really think they're there. They're +really and I think that hearing the + + align:start position:0% +really and I think that hearing the + + + align:start position:0% +really and I think that hearing the +noises, seeing the sights, going on the + + align:start position:0% +noises, seeing the sights, going on the + + + align:start position:0% +noises, seeing the sights, going on the +bus ride, seeing the fish market. I have + + align:start position:0% +bus ride, seeing the fish market. I have + + + align:start position:0% +bus ride, seeing the fish market. I have +to tell you the fish market. The girls + + align:start position:0% +to tell you the fish market. The girls + + + align:start position:0% +to tell you the fish market. The girls +saw the fish market. One girl goes, "I + + align:start position:0% +saw the fish market. One girl goes, "I + + + align:start position:0% +saw the fish market. One girl goes, "I +love fish sticks." And so I'm like, + + align:start position:0% +love fish sticks." And so I'm like, + + + align:start position:0% +love fish sticks." And so I'm like, +"They're cutting the fish up into big + + align:start position:0% +"They're cutting the fish up into big + + + align:start position:0% +"They're cutting the fish up into big +sections." I said, "Oh, that's nice. + + align:start position:0% +sections." I said, "Oh, that's nice. + + + align:start position:0% +sections." I said, "Oh, that's nice. +Well, you'll see all the fish later." + + align:start position:0% +Well, you'll see all the fish later." + + + align:start position:0% +Well, you'll see all the fish later." +And she goes, "I love." And I said, + + align:start position:0% +And she goes, "I love." And I said, + + + align:start position:0% +And she goes, "I love." And I said, +"Well, this is where it comes from. This + + align:start position:0% +"Well, this is where it comes from. This + + + align:start position:0% +"Well, this is where it comes from. This +is what happens before it's made into + + align:start position:0% +is what happens before it's made into + + + align:start position:0% +is what happens before it's made into +fish sticks." So, here we'll be talking + + align:start position:0% +fish sticks." So, here we'll be talking + + + align:start position:0% +fish sticks." So, here we'll be talking +about how food comes to the table. You + + align:start position:0% +about how food comes to the table. You + + + align:start position:0% +about how food comes to the table. You +know, what happens? It doesn't just + + align:start position:0% +know, what happens? It doesn't just + + + align:start position:0% +know, what happens? It doesn't just +materialize into fish sticks. We didn't + + align:start position:0% +materialize into fish sticks. We didn't + + + align:start position:0% +materialize into fish sticks. We didn't +just go out to the river and pull up the + + align:start position:0% +just go out to the river and pull up the + + + align:start position:0% +just go out to the river and pull up the +fish sticks. So, I think it's important + + align:start position:0% +fish sticks. So, I think it's important + + + align:start position:0% +fish sticks. So, I think it's important +for um you know, to see that we need + + align:start position:0% +for um you know, to see that we need + + + align:start position:0% +for um you know, to see that we need +food. People in Japan need food. People + + align:start position:0% +food. People in Japan need food. People + + + align:start position:0% +food. People in Japan need food. People +in China need food. We basically are all + + align:start position:0% +in China need food. We basically are all + + + align:start position:0% +in China need food. We basically are all +different, but we all have the same + + align:start position:0% +different, but we all have the same + + + align:start position:0% +different, but we all have the same +kinds of needs. So, + + align:start position:0% +kinds of needs. So, + + + align:start position:0% +kinds of needs. So, +um I don't know. It's an + + align:start position:0% +um I don't know. It's an + + + align:start position:0% +um I don't know. It's an +adventure. Want to see the old picture? + + align:start position:0% + + + + align:start position:0% + +This is a class I had that even at the + + align:start position:0% +This is a class I had that even at the + + + align:start position:0% +This is a class I had that even at the +very end of the + + align:start position:0% +very end of the + + + align:start position:0% +very end of the +day, they were trying to + + align:start position:0% +day, they were trying to + + + align:start position:0% +day, they were trying to +work because I totally identified + + align:start position:0% +work because I totally identified + + + align:start position:0% +work because I totally identified +with Chagarro on the uh film and they + + align:start position:0% +with Chagarro on the uh film and they + + + align:start position:0% +with Chagarro on the uh film and they +were looking at it and even when they + + align:start position:0% +were looking at it and even when they + + + align:start position:0% +were looking at it and even when they +were had their coat on and they're + + align:start position:0% +were had their coat on and they're + + + align:start position:0% +were had their coat on and they're +waiting for their parents to take them + + align:start position:0% +waiting for their parents to take them + + + align:start position:0% +waiting for their parents to take them +home, they would still go and explore in + + align:start position:0% +home, they would still go and explore in + + + align:start position:0% +home, they would still go and explore in +different parts of the um computer. + + align:start position:0% +different parts of the um computer. + + + align:start position:0% +different parts of the um computer. +Do I have a minute to tell you about the + + align:start position:0% +Do I have a minute to tell you about the + + + align:start position:0% +Do I have a minute to tell you about the +book? Sorry, I'm so + + align:start position:0% + + + + align:start position:0% + +hot. This is a project I was involved + + align:start position:0% +hot. This is a project I was involved + + + align:start position:0% +hot. This is a project I was involved +in. It's a real I mean really adventure. + + align:start position:0% +in. It's a real I mean really adventure. + + + align:start position:0% +in. It's a real I mean really adventure. +And so um this is the story of Shagira + + align:start position:0% +And so um this is the story of Shagira + + + align:start position:0% +And so um this is the story of Shagira +when he was in Japan because the story + + align:start position:0% +when he was in Japan because the story + + + align:start position:0% +when he was in Japan because the story +on the CD ROM is when he's grown up. So, + + align:start position:0% +on the CD ROM is when he's grown up. So, + + + align:start position:0% +on the CD ROM is when he's grown up. So, +this takes all the information from the + + align:start position:0% +this takes all the information from the + + + align:start position:0% +this takes all the information from the +CD ROM and makes it into a story + + align:start position:0% +CD ROM and makes it into a story + + + align:start position:0% +CD ROM and makes it into a story +that a teacher or a parent or librarian + + align:start position:0% +that a teacher or a parent or librarian + + + align:start position:0% +that a teacher or a parent or librarian +could read to the children and it shows + + align:start position:0% +could read to the children and it shows + + + align:start position:0% +could read to the children and it shows +real pictures and it also shows + + align:start position:0% +real pictures and it also shows + + + align:start position:0% +real pictures and it also shows +beautiful drawings and I think that um + + align:start position:0% +beautiful drawings and I think that um + + + align:start position:0% +beautiful drawings and I think that um +just it it's a story that about his + + align:start position:0% +just it it's a story that about his + + + align:start position:0% +just it it's a story that about his +family before he left and sort of how he + + align:start position:0% +family before he left and sort of how he + + + align:start position:0% +family before he left and sort of how he +had a very happy joy joyful life with + + align:start position:0% +had a very happy joy joyful life with + + + align:start position:0% +had a very happy joy joyful life with +his family. And he's after it shows them + + align:start position:0% +his family. And he's after it shows them + + + align:start position:0% +his family. And he's after it shows them +all the things he does with his going to + + align:start position:0% +all the things he does with his going to + + + align:start position:0% +all the things he does with his going to +the + + align:start position:0% +the + + + align:start position:0% +the +shrine, fishing with his grandfather, + + align:start position:0% +shrine, fishing with his grandfather, + + + align:start position:0% +shrine, fishing with his grandfather, +um visiting his grandfather's shoe shop, + + align:start position:0% +um visiting his grandfather's shoe shop, + + + align:start position:0% +um visiting his grandfather's shoe shop, +things that were just an intricral part + + align:start position:0% +things that were just an intricral part + + + align:start position:0% +things that were just an intricral part +of his life. going to the model shop and + + align:start position:0% +of his life. going to the model shop and + + + align:start position:0% +of his life. going to the model shop and +then to + + align:start position:0% +then to + + + align:start position:0% +then to +have, you know, when he's nine or 10 to + + align:start position:0% +have, you know, when he's nine or 10 to + + + align:start position:0% +have, you know, when he's nine or 10 to +be taken from his home roots and just + + align:start position:0% +be taken from his home roots and just + + + align:start position:0% +be taken from his home roots and just +brought over into a very strange world + + align:start position:0% +brought over into a very strange world + + + align:start position:0% +brought over into a very strange world +where he didn't speak the language and + + align:start position:0% +where he didn't speak the language and + + + align:start position:0% +where he didn't speak the language and +he didn't, you know, really understand + + align:start position:0% +he didn't, you know, really understand + + + align:start position:0% +he didn't, you know, really understand +or know any of the culture because he + + align:start position:0% +or know any of the culture because he + + + align:start position:0% +or know any of the culture because he +wasn't exposed to it. and then to have + + align:start position:0% +wasn't exposed to it. and then to have + + + align:start position:0% +wasn't exposed to it. and then to have +to deal with that. Um, and how he + + align:start position:0% +to deal with that. Um, and how he + + + align:start position:0% +to deal with that. Um, and how he +quickly became more Americanized that + + align:start position:0% +quickly became more Americanized that + + + align:start position:0% +quickly became more Americanized that +after a short or a year or so when + + align:start position:0% +after a short or a year or so when + + + align:start position:0% +after a short or a year or so when +um he found out that a letter he had + + align:start position:0% +um he found out that a letter he had + + + align:start position:0% +um he found out that a letter he had +sent to his grandfather was totally in + + align:start position:0% +sent to his grandfather was totally in + + + align:start position:0% +sent to his grandfather was totally in +in English and his grandfather couldn't + + align:start position:0% +in English and his grandfather couldn't + + + align:start position:0% +in English and his grandfather couldn't +read it and he didn't hadn't even + + align:start position:0% +read it and he didn't hadn't even + + + align:start position:0% +read it and he didn't hadn't even +realized that he had done that. So, um I + + align:start position:0% +realized that he had done that. So, um I + + + align:start position:0% +realized that he had done that. So, um I +think it a lot of the children I have + + align:start position:0% +think it a lot of the children I have + + + align:start position:0% +think it a lot of the children I have +bilingual children and a lot of them + + align:start position:0% +bilingual children and a lot of them + + + align:start position:0% +bilingual children and a lot of them +have um you know two languages or even + + align:start position:0% +have um you know two languages or even + + + align:start position:0% +have um you know two languages or even +three languages and I think this sort of + + align:start position:0% +three languages and I think this sort of + + + align:start position:0% +three languages and I think this sort of +really they understand that maybe + + align:start position:0% +really they understand that maybe + + + align:start position:0% +really they understand that maybe +sometimes I say things to them they + + align:start position:0% +sometimes I say things to them they + + + align:start position:0% +sometimes I say things to them they +don't quite understand what it is + + align:start position:0% +don't quite understand what it is + + + align:start position:0% +don't quite understand what it is +because it's not familiar to them but + + align:start position:0% +because it's not familiar to them but + + + align:start position:0% +because it's not familiar to them but +this sort of connects to their own their + + align:start position:0% +this sort of connects to their own their + + + align:start position:0% +this sort of connects to their own their +own life and I think that when you see + + align:start position:0% +own life and I think that when you see + + + align:start position:0% +own life and I think that when you see +Shagarro going back into Haratska and + + align:start position:0% +Shagarro going back into Haratska and + + + align:start position:0% +Shagarro going back into Haratska and +visiting the old haunts that he went to. + + align:start position:0% +visiting the old haunts that he went to. + + + align:start position:0% +visiting the old haunts that he went to. +And looking at the old photographs, you + + align:start position:0% +And looking at the old photographs, you + + + align:start position:0% +And looking at the old photographs, you +can see um you know how much he changed + + align:start position:0% +can see um you know how much he changed + + + align:start position:0% +can see um you know how much he changed +and how much he grew and how he would + + align:start position:0% +and how much he grew and how he would + + + align:start position:0% +and how much he grew and how he would +have that feeling. He's not quite sure + + align:start position:0% +have that feeling. He's not quite sure + + + align:start position:0% +have that feeling. He's not quite sure +which culture he belongs to. And maybe + + align:start position:0% +which culture he belongs to. And maybe + + + align:start position:0% +which culture he belongs to. And maybe +that's how a lot of our children feel. \ No newline at end of file diff --git a/rFGvvlsveOk.txt b/rFGvvlsveOk.txt new file mode 100644 index 0000000000000000000000000000000000000000..4e7bdc766303661373b4fad99c9cceb6c771eed6 --- /dev/null +++ b/rFGvvlsveOk.txt @@ -0,0 +1,579 @@ +align:start position:0% + +This insulating cylinder is free to + + align:start position:0% +This insulating cylinder is free to + + + align:start position:0% +This insulating cylinder is free to +rotate. + + align:start position:0% + + + + align:start position:0% + +It's centered between these + + align:start position:0% +It's centered between these + + + align:start position:0% +It's centered between these +electrodes which will be used to impose + + align:start position:0% +electrodes which will be used to impose + + + align:start position:0% +electrodes which will be used to impose +an electric + + align:start position:0% +an electric + + + align:start position:0% +an electric +field transverse to the axis of + + align:start position:0% + + + + align:start position:0% + +rotation. The electrodes and cylinder + + align:start position:0% +rotation. The electrodes and cylinder + + + align:start position:0% +rotation. The electrodes and cylinder +are immersed in slightly conducting corn + + align:start position:0% +are immersed in slightly conducting corn + + + align:start position:0% +are immersed in slightly conducting corn +oil. As we apply the potential to the + + align:start position:0% +oil. As we apply the potential to the + + + align:start position:0% +oil. As we apply the potential to the +plates, the threshold of about 20 + + align:start position:0% +plates, the threshold of about 20 + + + align:start position:0% +plates, the threshold of about 20 +kovolts is reached and the cylinder + + align:start position:0% +kovolts is reached and the cylinder + + + align:start position:0% +kovolts is reached and the cylinder +begins to + + align:start position:0% + + + + align:start position:0% + +rotate. Which direction is a matter of + + align:start position:0% +rotate. Which direction is a matter of + + + align:start position:0% +rotate. Which direction is a matter of +chance? + + align:start position:0% + + + + align:start position:0% + +You need two more pieces of information + + align:start position:0% +You need two more pieces of information + + + align:start position:0% +You need two more pieces of information +to explain this experiment. The Teflon + + align:start position:0% +to explain this experiment. The Teflon + + + align:start position:0% +to explain this experiment. The Teflon +rotor is a very good insulator compared + + align:start position:0% +rotor is a very good insulator compared + + + align:start position:0% +rotor is a very good insulator compared +to the corn oil and the oil has a + + align:start position:0% +to the corn oil and the oil has a + + + align:start position:0% +to the corn oil and the oil has a +relaxation time on the same order as the + + align:start position:0% +relaxation time on the same order as the + + + align:start position:0% +relaxation time on the same order as the +period of rotation. + + align:start position:0% +period of rotation. + + + align:start position:0% +period of rotation. +The rotor acts as an insulator in series + + align:start position:0% +The rotor acts as an insulator in series + + + align:start position:0% +The rotor acts as an insulator in series +with the regions of conducting liquid + + align:start position:0% +with the regions of conducting liquid + + + align:start position:0% +with the regions of conducting liquid +adjacent to the + + align:start position:0% +adjacent to the + + + align:start position:0% +adjacent to the +electrodes. As surface charges build up + + align:start position:0% +electrodes. As surface charges build up + + + align:start position:0% +electrodes. As surface charges build up +on the electrodes, they induce + + align:start position:0% +on the electrodes, they induce + + + align:start position:0% +on the electrodes, they induce +neighboring surface charges of the same + + align:start position:0% +neighboring surface charges of the same + + + align:start position:0% +neighboring surface charges of the same +sign on the rotor liquid + + align:start position:0% +sign on the rotor liquid + + + align:start position:0% +sign on the rotor liquid +interface. A perturbation of the static + + align:start position:0% +interface. A perturbation of the static + + + align:start position:0% +interface. A perturbation of the static +cylinder carries these charges + + align:start position:0% +cylinder carries these charges + + + align:start position:0% +cylinder carries these charges +along. The motion affects the field. + + align:start position:0% +along. The motion affects the field. + + + align:start position:0% +along. The motion affects the field. +In return, there is a repulsion of the + + align:start position:0% +In return, there is a repulsion of the + + + align:start position:0% +In return, there is a repulsion of the +like charges that tends to sustain the + + align:start position:0% +like charges that tends to sustain the + + + align:start position:0% +like charges that tends to sustain the +rotation. The field affects the + + align:start position:0% + + + + align:start position:0% + +motion. Steady rotation is maintained + + align:start position:0% +motion. Steady rotation is maintained + + + align:start position:0% +motion. Steady rotation is maintained +because the convection of the surface + + align:start position:0% +because the convection of the surface + + + align:start position:0% +because the convection of the surface +charge is just compensated by its + + align:start position:0% +charge is just compensated by its + + + align:start position:0% +charge is just compensated by its +relaxation through conduction in the + + align:start position:0% +relaxation through conduction in the + + + align:start position:0% +relaxation through conduction in the +corn oil. + + align:start position:0% +corn oil. + + + align:start position:0% +corn oil. +The cylinder begins to rotate only + + align:start position:0% +The cylinder begins to rotate only + + + align:start position:0% +The cylinder begins to rotate only +because there is both an effect of the + + align:start position:0% +because there is both an effect of the + + + align:start position:0% +because there is both an effect of the +field on the motion and of the motion on + + align:start position:0% +field on the motion and of the motion on + + + align:start position:0% +field on the motion and of the motion on +the + + align:start position:0% + + + + align:start position:0% + +field. The rotation alters the charge + + align:start position:0% +field. The rotation alters the charge + + + align:start position:0% +field. The rotation alters the charge +distribution because the ratio of + + align:start position:0% +distribution because the ratio of + + + align:start position:0% +distribution because the ratio of +relaxation time in the oil to the time + + align:start position:0% +relaxation time in the oil to the time + + + align:start position:0% +relaxation time in the oil to the time +required for a point on the cylinder + + align:start position:0% +required for a point on the cylinder + + + align:start position:0% +required for a point on the cylinder +surface to make one revolution is about + + align:start position:0% +surface to make one revolution is about + + + align:start position:0% +surface to make one revolution is about +unity. + + align:start position:0% + + + + align:start position:0% + +The field induced rotations of the + + align:start position:0% +The field induced rotations of the + + + align:start position:0% +The field induced rotations of the +cylinder also are responsible for this + + align:start position:0% + + + + align:start position:0% + +motion. These cells of fluid are + + align:start position:0% +motion. These cells of fluid are + + + align:start position:0% +motion. These cells of fluid are +spinning on the free surface of corn + + align:start position:0% +spinning on the free surface of corn + + + align:start position:0% +spinning on the free surface of corn +oil. + + align:start position:0% + + + + align:start position:0% + +The fluid is contained in this box which + + align:start position:0% +The fluid is contained in this box which + + + align:start position:0% +The fluid is contained in this box which +has two electrodes lying flat on its + + align:start position:0% + + + + align:start position:0% + +bottom. They're separated by about 1/4 + + align:start position:0% +bottom. They're separated by about 1/4 + + + align:start position:0% +bottom. They're separated by about 1/4 +in. + + align:start position:0% + + + + align:start position:0% + +Bubbles injected on the surface show how + + align:start position:0% +Bubbles injected on the surface show how + + + align:start position:0% +Bubbles injected on the surface show how +the rotations + + align:start position:0% + + + + align:start position:0% + +develop. Passage of current through the + + align:start position:0% +develop. Passage of current through the + + + align:start position:0% +develop. Passage of current through the +oil results in a potential drop along + + align:start position:0% +oil results in a potential drop along + + + align:start position:0% +oil results in a potential drop along +the + + align:start position:0% + + + + align:start position:0% + +interface. From above, we see the + + align:start position:0% +interface. From above, we see the + + + align:start position:0% +interface. From above, we see the +charges on the + + align:start position:0% +charges on the + + + align:start position:0% +charges on the +electrodes and on the + + align:start position:0% +electrodes and on the + + + align:start position:0% +electrodes and on the +interface. + + align:start position:0% +interface. + + + align:start position:0% +interface. +Any slight fluid rotation results in + + align:start position:0% +Any slight fluid rotation results in + + + align:start position:0% +Any slight fluid rotation results in +charge redistribution which encourages + + align:start position:0% +charge redistribution which encourages + + + align:start position:0% +charge redistribution which encourages +further rotation. + + align:start position:0% +further rotation. + + + align:start position:0% +further rotation. +The interface is unstable to cellular + + align:start position:0% +The interface is unstable to cellular + + + align:start position:0% +The interface is unstable to cellular +motions in its own plane and the + + align:start position:0% +motions in its own plane and the + + + align:start position:0% +motions in its own plane and the +resulting cell pattern is one which + + align:start position:0% +resulting cell pattern is one which + + + align:start position:0% +resulting cell pattern is one which +reduces viscous drag to a minimum. \ No newline at end of file diff --git a/rkFY8WB8tfs.txt b/rkFY8WB8tfs.txt new file mode 100644 index 0000000000000000000000000000000000000000..481ab59c2fb2d4b5c7a2d2f65fbba860f173d8d1 --- /dev/null +++ b/rkFY8WB8tfs.txt @@ -0,0 +1,9835 @@ +align:start position:0% + +so we're going to talk a little bit + + align:start position:0% +so we're going to talk a little bit + + + align:start position:0% +so we're going to talk a little bit +about bohr and then we're going to talk + + align:start position:0% +about bohr and then we're going to talk + + + align:start position:0% +about bohr and then we're going to talk +about ionization energy which is a theme + + align:start position:0% +about ionization energy which is a theme + + + align:start position:0% +about ionization energy which is a theme +that's going to come back + + align:start position:0% +that's going to come back + + + align:start position:0% +that's going to come back +a couple more times very important + + align:start position:0% +a couple more times very important + + + align:start position:0% +a couple more times very important +and then we're going quantum + + align:start position:0% +and then we're going quantum + + + align:start position:0% +and then we're going quantum +we're going quantum and that's why this + + align:start position:0% +we're going quantum and that's why this + + + align:start position:0% +we're going quantum and that's why this +is a very exciting day + + align:start position:0% +is a very exciting day + + + align:start position:0% +is a very exciting day +uh for me and i i'm hoping it will be + + align:start position:0% +uh for me and i i'm hoping it will be + + + align:start position:0% +uh for me and i i'm hoping it will be +for you too + + align:start position:0% +for you too + + + align:start position:0% +for you too +it's why i have t-shirts it's also a + + align:start position:0% +it's why i have t-shirts it's also a + + + align:start position:0% +it's why i have t-shirts it's also a +goody bag day there's just all sorts of + + align:start position:0% +goody bag day there's just all sorts of + + + align:start position:0% +goody bag day there's just all sorts of +things + + align:start position:0% +things + + + align:start position:0% +things +happening today so i'm very excited + + align:start position:0% +happening today so i'm very excited + + + align:start position:0% +happening today so i'm very excited +this is how we ended our lecture on + + align:start position:0% +this is how we ended our lecture on + + + align:start position:0% +this is how we ended our lecture on +wednesday + + align:start position:0% +wednesday + + + align:start position:0% +wednesday +okay i was showing you this as part of + + align:start position:0% +okay i was showing you this as part of + + + align:start position:0% +okay i was showing you this as part of +my why this matters which started with + + align:start position:0% +my why this matters which started with + + + align:start position:0% +my why this matters which started with +refrigerators + + align:start position:0% +refrigerators + + + align:start position:0% +refrigerators +and then we talked about a chemistry + + align:start position:0% +and then we talked about a chemistry + + + align:start position:0% +and then we talked about a chemistry +problem cfcs + + align:start position:0% +problem cfcs + + + align:start position:0% +problem cfcs +and we talked about how those were + + align:start position:0% +and we talked about how those were + + + align:start position:0% +and we talked about how those were +destroying the ozone layer of this + + align:start position:0% +destroying the ozone layer of this + + + align:start position:0% +destroying the ozone layer of this +planet + + align:start position:0% +planet + + + align:start position:0% +planet +now why is that important and i had this + + align:start position:0% +now why is that important and i had this + + + align:start position:0% +now why is that important and i had this +picture up there + + align:start position:0% +picture up there + + + align:start position:0% +picture up there +to help explain it this is + + align:start position:0% +to help explain it this is + + + align:start position:0% +to help explain it this is +just to to make sure we all see what + + align:start position:0% +just to to make sure we all see what + + + align:start position:0% +just to to make sure we all see what +this is you know i'm + + align:start position:0% +this is you know i'm + + + align:start position:0% +this is you know i'm +showing it here again this is the energy + + align:start position:0% +showing it here again this is the energy + + + align:start position:0% +showing it here again this is the energy +watts per meter squared + + align:start position:0% +watts per meter squared + + + align:start position:0% +watts per meter squared +that we get from the sun right and + + align:start position:0% +that we get from the sun right and + + + align:start position:0% +that we get from the sun right and +and you can measure that up on top of + + align:start position:0% +and you can measure that up on top of + + + align:start position:0% +and you can measure that up on top of +the atmosphere so there's no atmosphere + + align:start position:0% +the atmosphere so there's no atmosphere + + + align:start position:0% +the atmosphere so there's no atmosphere +there + + align:start position:0% +there + + + align:start position:0% +there +and this is what it looks like right + + align:start position:0% +and this is what it looks like right + + + align:start position:0% +and this is what it looks like right +that's the energy + + align:start position:0% +that's the energy + + + align:start position:0% +that's the energy +as a function of the wavelength or + + align:start position:0% +as a function of the wavelength or + + + align:start position:0% +as a function of the wavelength or +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +or energy of the photon you now know how + + align:start position:0% +or energy of the photon you now know how + + + align:start position:0% +or energy of the photon you now know how +to go back and forth between those + + align:start position:0% + + + + align:start position:0% + +but see on the planet here once you once + + align:start position:0% +but see on the planet here once you once + + + align:start position:0% +but see on the planet here once you once +you + + align:start position:0% +you + + + align:start position:0% +you +have the atmosphere you get a different + + align:start position:0% +have the atmosphere you get a different + + + align:start position:0% +have the atmosphere you get a different +spectrum and the reason is and it's + + align:start position:0% +spectrum and the reason is and it's + + + align:start position:0% +spectrum and the reason is and it's +shown here that + + align:start position:0% +shown here that + + + align:start position:0% +shown here that +some of the molecules in the atmosphere + + align:start position:0% +some of the molecules in the atmosphere + + + align:start position:0% +some of the molecules in the atmosphere +are absorbing + + align:start position:0% +are absorbing + + + align:start position:0% +are absorbing +parts of that spectrum so what we see on + + align:start position:0% +parts of that spectrum so what we see on + + + align:start position:0% +parts of that spectrum so what we see on +the planet is different + + align:start position:0% +the planet is different + + + align:start position:0% +the planet is different +right and we talk about this in terms of + + align:start position:0% +right and we talk about this in terms of + + + align:start position:0% +right and we talk about this in terms of +why this matters + + align:start position:0% +why this matters + + + align:start position:0% +why this matters +and and how ozone you know so you say + + align:start position:0% +and and how ozone you know so you say + + + align:start position:0% +and and how ozone you know so you say +well i said i mentioned oh if you could + + align:start position:0% +well i said i mentioned oh if you could + + + align:start position:0% +well i said i mentioned oh if you could +only if we could only see out here + + align:start position:0% +only if we could only see out here + + + align:start position:0% +only if we could only see out here +right the visible is here that's the + + align:start position:0% +right the visible is here that's the + + + align:start position:0% +right the visible is here that's the +visible okay there's the + + align:start position:0% +visible okay there's the + + + align:start position:0% +visible okay there's the +frequencies of the visible but what if + + align:start position:0% +frequencies of the visible but what if + + + align:start position:0% +frequencies of the visible but what if +it were here the planet would be totally + + align:start position:0% +it were here the planet would be totally + + + align:start position:0% +it were here the planet would be totally +dark + + align:start position:0% +dark + + + align:start position:0% +dark +because no light would get through the + + align:start position:0% +because no light would get through the + + + align:start position:0% +because no light would get through the +absorption that happens from + + align:start position:0% +absorption that happens from + + + align:start position:0% +absorption that happens from +those molecules on the other hand over + + align:start position:0% +those molecules on the other hand over + + + align:start position:0% +those molecules on the other hand over +here we've got ozone that's protecting + + align:start position:0% +here we've got ozone that's protecting + + + align:start position:0% +here we've got ozone that's protecting +us + + align:start position:0% +us + + + align:start position:0% +us +it is absorbing light in the higher + + align:start position:0% +it is absorbing light in the higher + + + align:start position:0% +it is absorbing light in the higher +frequency in the higher frequency + + align:start position:0% +frequency in the higher frequency + + + align:start position:0% +frequency in the higher frequency +which means lower wavelength that's the + + align:start position:0% +which means lower wavelength that's the + + + align:start position:0% +which means lower wavelength that's the +uv + + align:start position:0% +uv + + + align:start position:0% +uv +and that's why that was such an + + align:start position:0% +and that's why that was such an + + + align:start position:0% +and that's why that was such an +important problem is to not destroy + + align:start position:0% +important problem is to not destroy + + + align:start position:0% +important problem is to not destroy +those precious ozone molecules + + align:start position:0% +those precious ozone molecules + + + align:start position:0% +those precious ozone molecules +okay so i want to make sure that we and + + align:start position:0% +okay so i want to make sure that we and + + + align:start position:0% +okay so i want to make sure that we and +we understood this in terms of + + align:start position:0% +we understood this in terms of + + + align:start position:0% +we understood this in terms of +energy transitions because how do these + + align:start position:0% +energy transitions because how do these + + + align:start position:0% +energy transitions because how do these +things absorb light + + align:start position:0% +things absorb light + + + align:start position:0% +things absorb light +well they do just what we said which is + + align:start position:0% +well they do just what we said which is + + + align:start position:0% +well they do just what we said which is +they take the energy from + + align:start position:0% +they take the energy from + + + align:start position:0% +they take the energy from +a kind of light and and an electron then + + align:start position:0% +a kind of light and and an electron then + + + align:start position:0% +a kind of light and and an electron then +takes that energy absorbs it to be + + align:start position:0% +takes that energy absorbs it to be + + + align:start position:0% +takes that energy absorbs it to be +excited and it goes from one energy + + align:start position:0% +excited and it goes from one energy + + + align:start position:0% +excited and it goes from one energy +level + + align:start position:0% +level + + + align:start position:0% +level +to another right we did that in terms of + + align:start position:0% +to another right we did that in terms of + + + align:start position:0% +to another right we did that in terms of +the board levels + + align:start position:0% +the board levels + + + align:start position:0% +the board levels +so i want to do that and that is what + + align:start position:0% +so i want to do that and that is what + + + align:start position:0% +so i want to do that and that is what +you have right here + + align:start position:0% +you have right here + + + align:start position:0% +you have right here +right you have a way to see that visible + + align:start position:0% +right you have a way to see that visible + + + align:start position:0% +right you have a way to see that visible +spectrum so we'll talk about that + + align:start position:0% +spectrum so we'll talk about that + + + align:start position:0% +spectrum so we'll talk about that +as well oh we'll talk about it right now + + align:start position:0% +as well oh we'll talk about it right now + + + align:start position:0% +as well oh we'll talk about it right now +because i have a slide on it + + align:start position:0% +because i have a slide on it + + + align:start position:0% +because i have a slide on it +so you have what is known as + + align:start position:0% +so you have what is known as + + + align:start position:0% +so you have what is known as +a spectroscope or the most powerful way + + align:start position:0% +a spectroscope or the most powerful way + + + align:start position:0% +a spectroscope or the most powerful way +to see light + + align:start position:0% +to see light + + + align:start position:0% +to see light +ever designed and and if you look + + align:start position:0% +ever designed and and if you look + + + align:start position:0% +ever designed and and if you look +through this + + align:start position:0% +through this + + + align:start position:0% +through this +okay don't look at the uv please don't + + align:start position:0% +okay don't look at the uv please don't + + + align:start position:0% +okay don't look at the uv please don't +look at the sun + + align:start position:0% +look at the sun + + + align:start position:0% +look at the sun +with this please don't do that but we + + align:start position:0% +with this please don't do that but we + + + align:start position:0% +with this please don't do that but we +gave you + + align:start position:0% +gave you + + + align:start position:0% +gave you +light sources to look at like that right + + align:start position:0% +light sources to look at like that right + + + align:start position:0% +light sources to look at like that right +or + + align:start position:0% +or + + + align:start position:0% +or +you could look at that or you could look + + align:start position:0% +you could look at that or you could look + + + align:start position:0% +you could look at that or you could look +at like things around you with it + + align:start position:0% +at like things around you with it + + + align:start position:0% +at like things around you with it +and what are you seeing you're seeing + + align:start position:0% +and what are you seeing you're seeing + + + align:start position:0% +and what are you seeing you're seeing +this you're seeing the spectrum + + align:start position:0% +this you're seeing the spectrum + + + align:start position:0% +this you're seeing the spectrum +in the visible you're seeing it in this + + align:start position:0% +in the visible you're seeing it in this + + + align:start position:0% +in the visible you're seeing it in this +part okay + + align:start position:0% +part okay + + + align:start position:0% +part okay +but from this you are also what you are + + align:start position:0% +but from this you are also what you are + + + align:start position:0% +but from this you are also what you are +seeing + + align:start position:0% +seeing + + + align:start position:0% +seeing +are literally electron transitions you + + align:start position:0% +are literally electron transitions you + + + align:start position:0% +are literally electron transitions you +are literally + + align:start position:0% +are literally + + + align:start position:0% +are literally +and that's what i want you to think + + align:start position:0% +and that's what i want you to think + + + align:start position:0% +and that's what i want you to think +about that's why i wanted you to have + + align:start position:0% +about that's why i wanted you to have + + + align:start position:0% +about that's why i wanted you to have +this power + + align:start position:0% +this power + + + align:start position:0% +this power +this power which means responsibility as + + align:start position:0% +this power which means responsibility as + + + align:start position:0% +this power which means responsibility as +we know but + + align:start position:0% +we know but + + + align:start position:0% +we know but +now you can not only see light you can + + align:start position:0% +now you can not only see light you can + + + align:start position:0% +now you can not only see light you can +see electron transitions + + align:start position:0% +see electron transitions + + + align:start position:0% +see electron transitions +i want you to think about that as you're + + align:start position:0% +i want you to think about that as you're + + + align:start position:0% +i want you to think about that as you're +seeing light + + align:start position:0% +seeing light + + + align:start position:0% +seeing light +and and i want you to think about it in + + align:start position:0% +and and i want you to think about it in + + + align:start position:0% +and and i want you to think about it in +terms of what we learned on wednesday + + align:start position:0% +terms of what we learned on wednesday + + + align:start position:0% +terms of what we learned on wednesday +which is bore + + align:start position:0% +which is bore + + + align:start position:0% +which is bore +right and so let's let's just put that + + align:start position:0% +right and so let's let's just put that + + + align:start position:0% +right and so let's let's just put that +here + + align:start position:0% +here + + + align:start position:0% +here +okay so we had bohr and + + align:start position:0% +okay so we had bohr and + + + align:start position:0% +okay so we had bohr and +in the bohr model we said the energy + + align:start position:0% +in the bohr model we said the energy + + + align:start position:0% +in the bohr model we said the energy +is going to be quantized minus 13.6 + + align:start position:0% +is going to be quantized minus 13.6 + + + align:start position:0% +is going to be quantized minus 13.6 +electron volts times the atomic number + + align:start position:0% +electron volts times the atomic number + + + align:start position:0% +electron volts times the atomic number +squared divided by n squared + + align:start position:0% +squared divided by n squared + + + align:start position:0% +squared divided by n squared +right and so like for hydrogen + + align:start position:0% +right and so like for hydrogen + + + align:start position:0% +right and so like for hydrogen +for example this is equal to uh minus + + align:start position:0% +for example this is equal to uh minus + + + align:start position:0% +for example this is equal to uh minus +13.6 ev + + align:start position:0% +13.6 ev + + + align:start position:0% +13.6 ev +right because z is one over n squared so + + align:start position:0% +right because z is one over n squared so + + + align:start position:0% +right because z is one over n squared so +that was our + + align:start position:0% +that was our + + + align:start position:0% +that was our +for hydrogen z equals + + align:start position:0% +for hydrogen z equals + + + align:start position:0% +for hydrogen z equals +one all right and so that that's one and + + align:start position:0% +one all right and so that that's one and + + + align:start position:0% +one all right and so that that's one and +that's it + + align:start position:0% +that's it + + + align:start position:0% +that's it +but n is equal to one two + + align:start position:0% +but n is equal to one two + + + align:start position:0% +but n is equal to one two +three etc it's quantized right this was + + align:start position:0% +three etc it's quantized right this was + + + align:start position:0% +three etc it's quantized right this was +this was the whole uh kind of discussion + + align:start position:0% +this was the whole uh kind of discussion + + + align:start position:0% +this was the whole uh kind of discussion +and theme of wednesday's lecture + + align:start position:0% +and theme of wednesday's lecture + + + align:start position:0% +and theme of wednesday's lecture +and and and that got us to these levels + + align:start position:0% +and and and that got us to these levels + + + align:start position:0% +and and and that got us to these levels +these bore levels which are places where + + align:start position:0% +these bore levels which are places where + + + align:start position:0% +these bore levels which are places where +energetic places energies of the + + align:start position:0% +energetic places energies of the + + + align:start position:0% +energetic places energies of the +electron + + align:start position:0% +electron + + + align:start position:0% +electron +right so we'd have these levels + + align:start position:0% +right so we'd have these levels + + + align:start position:0% +right so we'd have these levels +that kept on going until you're at + + align:start position:0% +that kept on going until you're at + + + align:start position:0% +that kept on going until you're at +somehow + + align:start position:0% + + + + align:start position:0% + +right so if this is energy + + align:start position:0% +right so if this is energy + + + align:start position:0% +right so if this is energy +right and and this would be like n + + align:start position:0% +right and and this would be like n + + + align:start position:0% +right and and this would be like n +equals one + + align:start position:0% +equals one + + + align:start position:0% +equals one +n equals two these are the energies + + align:start position:0% +n equals two these are the energies + + + align:start position:0% +n equals two these are the energies +right right there i'm just plugging in + + align:start position:0% +right right there i'm just plugging in + + + align:start position:0% +right right there i'm just plugging in +and this would be like n equals infinity + + align:start position:0% +and this would be like n equals infinity + + + align:start position:0% +and this would be like n equals infinity +so the energy here + + align:start position:0% +so the energy here + + + align:start position:0% +so the energy here +would be zero and for the hydrogen atom + + align:start position:0% +would be zero and for the hydrogen atom + + + align:start position:0% +would be zero and for the hydrogen atom +the energy here would be minus 13.6 + + align:start position:0% +the energy here would be minus 13.6 + + + align:start position:0% +the energy here would be minus 13.6 +electron volts right if that's hydrogen + + align:start position:0% +electron volts right if that's hydrogen + + + align:start position:0% +electron volts right if that's hydrogen +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +now i'm leaving this here i want to use + + align:start position:0% +now i'm leaving this here i want to use + + + align:start position:0% +now i'm leaving this here i want to use +this that's why i'm putting it back up + + align:start position:0% +this that's why i'm putting it back up + + + align:start position:0% +this that's why i'm putting it back up +okay because look now you can use this + + align:start position:0% +okay because look now you can use this + + + align:start position:0% +okay because look now you can use this +to start + + align:start position:0% +to start + + + align:start position:0% +to start +understanding light and so you use this + + align:start position:0% +understanding light and so you use this + + + align:start position:0% +understanding light and so you use this +and you look at light sources + + align:start position:0% +and you look at light sources + + + align:start position:0% +and you look at light sources +and you can start thinking about things + + align:start position:0% +and you can start thinking about things + + + align:start position:0% +and you can start thinking about things +in terms of energy transitions so let's + + align:start position:0% +in terms of energy transitions so let's + + + align:start position:0% +in terms of energy transitions so let's +take a look so what if i + + align:start position:0% +take a look so what if i + + + align:start position:0% +take a look so what if i +uh just look at some light sources right + + align:start position:0% +uh just look at some light sources right + + + align:start position:0% +uh just look at some light sources right +okay so that's what you see that's like + + align:start position:0% +okay so that's what you see that's like + + + align:start position:0% +okay so that's what you see that's like +the sun + + align:start position:0% +the sun + + + align:start position:0% +the sun +right so that's daylight and now we're + + align:start position:0% +right so that's daylight and now we're + + + align:start position:0% +right so that's daylight and now we're +getting into the the mode of seeing + + align:start position:0% +getting into the the mode of seeing + + + align:start position:0% +getting into the the mode of seeing +light like this right it's in intensity + + align:start position:0% +light like this right it's in intensity + + + align:start position:0% +light like this right it's in intensity +salute versus uh wavelength right + + align:start position:0% +salute versus uh wavelength right + + + align:start position:0% +salute versus uh wavelength right +and there you go you go and now if you + + align:start position:0% +and there you go you go and now if you + + + align:start position:0% +and there you go you go and now if you +look at sort of an incandescent light + + align:start position:0% +look at sort of an incandescent light + + + align:start position:0% +look at sort of an incandescent light +bulb + + align:start position:0% +bulb + + + align:start position:0% +bulb +all right it'll look something like this + + align:start position:0% +all right it'll look something like this + + + align:start position:0% +all right it'll look something like this +so it's it's warm + + align:start position:0% +so it's it's warm + + + align:start position:0% +so it's it's warm +there's a little more red right you + + align:start position:0% +there's a little more red right you + + + align:start position:0% +there's a little more red right you +can't get up to the sun's temperature + + align:start position:0% +can't get up to the sun's temperature + + + align:start position:0% +can't get up to the sun's temperature +but you get pretty hot + + align:start position:0% +but you get pretty hot + + + align:start position:0% +but you get pretty hot +so you see this nice kind of looking + + align:start position:0% +so you see this nice kind of looking + + + align:start position:0% +so you see this nice kind of looking +spectrum and oh here's a halogen + + align:start position:0% +spectrum and oh here's a halogen + + + align:start position:0% +spectrum and oh here's a halogen +all right that looks kind of closer + + align:start position:0% +all right that looks kind of closer + + + align:start position:0% +all right that looks kind of closer +maybe look at what happens when we go + + align:start position:0% +maybe look at what happens when we go + + + align:start position:0% +maybe look at what happens when we go +fluorescent ah + + align:start position:0% +fluorescent ah + + + align:start position:0% +fluorescent ah +look at that why does fluorescent light + + align:start position:0% +look at that why does fluorescent light + + + align:start position:0% +look at that why does fluorescent light +give us headaches + + align:start position:0% +give us headaches + + + align:start position:0% +give us headaches +well that might be other reasons but but + + align:start position:0% +well that might be other reasons but but + + + align:start position:0% +well that might be other reasons but but +look at this spectrum + + align:start position:0% +look at this spectrum + + + align:start position:0% +look at this spectrum +that doesn't look like that that's why + + align:start position:0% +that doesn't look like that that's why + + + align:start position:0% +that doesn't look like that that's why +we all have so much trouble with floor + + align:start position:0% +we all have so much trouble with floor + + + align:start position:0% +we all have so much trouble with floor +and here's leds and you can buy your + + align:start position:0% +and here's leds and you can buy your + + + align:start position:0% +and here's leds and you can buy your +cool white leds and your warm white leds + + align:start position:0% +cool white leds and your warm white leds + + + align:start position:0% +cool white leds and your warm white leds +but look + + align:start position:0% +but look + + + align:start position:0% +but look +they're still not they're not that right + + align:start position:0% +they're still not they're not that right + + + align:start position:0% +they're still not they're not that right +there's been a lot of work on this + + align:start position:0% +there's been a lot of work on this + + + align:start position:0% +there's been a lot of work on this +can we get this to be that right + + align:start position:0% +can we get this to be that right + + + align:start position:0% +can we get this to be that right +and and so so now we are armed + + align:start position:0% +and and so so now we are armed + + + align:start position:0% +and and so so now we are armed +with with great power + + align:start position:0% + + + + align:start position:0% + +and so you can look at things you see oh + + align:start position:0% +and so you can look at things you see oh + + + align:start position:0% +and so you can look at things you see oh +i see that it has + + align:start position:0% +i see that it has + + + align:start position:0% +i see that it has +uh this large peak because i'm looking + + align:start position:0% +uh this large peak because i'm looking + + + align:start position:0% +uh this large peak because i'm looking +at a fluorescent light + + align:start position:0% +at a fluorescent light + + + align:start position:0% +at a fluorescent light +within and i see that it's got this + + align:start position:0% +within and i see that it's got this + + + align:start position:0% +within and i see that it's got this +stronger peak in the blue + + align:start position:0% +stronger peak in the blue + + + align:start position:0% +stronger peak in the blue +maybe i could just absorb a little of + + align:start position:0% +maybe i could just absorb a little of + + + align:start position:0% +maybe i could just absorb a little of +that what if i came up with a coating + + align:start position:0% +that what if i came up with a coating + + + align:start position:0% +that what if i came up with a coating +right that i could put on that cool led + + align:start position:0% +right that i could put on that cool led + + + align:start position:0% +right that i could put on that cool led +bulb to make it just a little bit more + + align:start position:0% +bulb to make it just a little bit more + + + align:start position:0% +bulb to make it just a little bit more +look like that + + align:start position:0% +look like that + + + align:start position:0% +look like that +well now we know how to we might be able + + align:start position:0% +well now we know how to we might be able + + + align:start position:0% +well now we know how to we might be able +to use bore to do this + + align:start position:0% +to use bore to do this + + + align:start position:0% +to use bore to do this +right because because what if i say okay + + align:start position:0% +right because because what if i say okay + + + align:start position:0% +right because because what if i say okay +the + + align:start position:0% +the + + + align:start position:0% +the +the wavelength of that is around 450. + + align:start position:0% +the wavelength of that is around 450. + + + align:start position:0% +the wavelength of that is around 450. +so if the wavelength is 450 nanometers + + align:start position:0% +so if the wavelength is 450 nanometers + + + align:start position:0% +so if the wavelength is 450 nanometers +then i know you know remember we did + + align:start position:0% +then i know you know remember we did + + + align:start position:0% +then i know you know remember we did +this + + align:start position:0% +this + + + align:start position:0% +this +waves right light waves we can go back + + align:start position:0% +waves right light waves we can go back + + + align:start position:0% +waves right light waves we can go back +and forth + + align:start position:0% +and forth + + + align:start position:0% +and forth +between uh frequency below + + align:start position:0% +between uh frequency below + + + align:start position:0% +between uh frequency below +how's it going all right welcome to + + align:start position:0% +how's it going all right welcome to + + + align:start position:0% +how's it going all right welcome to +class um + + align:start position:0% +class um + + + align:start position:0% +class um +and uh and energy energy + + align:start position:0% +and uh and energy energy + + + align:start position:0% +and uh and energy energy +equals h c over lambda + + align:start position:0% +equals h c over lambda + + + align:start position:0% +equals h c over lambda +oh plank thank you + + align:start position:0% +oh plank thank you + + + align:start position:0% +oh plank thank you +and this is roughly 2.75 + + align:start position:0% +and this is roughly 2.75 + + + align:start position:0% +and this is roughly 2.75 +electron volts for that wavelength + + align:start position:0% +electron volts for that wavelength + + + align:start position:0% +electron volts for that wavelength +2.75 electron volts right okay well but + + align:start position:0% +2.75 electron volts right okay well but + + + align:start position:0% +2.75 electron volts right okay well but +see now + + align:start position:0% +see now + + + align:start position:0% +see now +but i want to absorb some of those + + align:start position:0% +but i want to absorb some of those + + + align:start position:0% +but i want to absorb some of those +photons + + align:start position:0% +photons + + + align:start position:0% +photons +i'll pose a problem what if i have + + align:start position:0% +i'll pose a problem what if i have + + + align:start position:0% +i'll pose a problem what if i have +an atom so question right + + align:start position:0% +an atom so question right + + + align:start position:0% +an atom so question right +so i have an atom an atom + + align:start position:0% +so i have an atom an atom + + + align:start position:0% +so i have an atom an atom +that has + + align:start position:0% +that has + + + align:start position:0% +that has +an n equal 4 to n + + align:start position:0% +an n equal 4 to n + + + align:start position:0% +an n equal 4 to n +equal 5 transition + + align:start position:0% +equal 5 transition + + + align:start position:0% +equal 5 transition +that absorbs so i'm i'm telling you now + + align:start position:0% +that absorbs so i'm i'm telling you now + + + align:start position:0% +that absorbs so i'm i'm telling you now +this energy so i'm telling you now + + align:start position:0% +this energy so i'm telling you now + + + align:start position:0% +this energy so i'm telling you now +i've got some atom and i know there's a + + align:start position:0% +i've got some atom and i know there's a + + + align:start position:0% +i've got some atom and i know there's a +transition in it + + align:start position:0% +transition in it + + + align:start position:0% +transition in it +it has an electron transition because + + align:start position:0% +it has an electron transition because + + + align:start position:0% +it has an electron transition because +remember we're going from electron + + align:start position:0% +remember we're going from electron + + + align:start position:0% +remember we're going from electron +transitions to light energy back and + + align:start position:0% +transitions to light energy back and + + + align:start position:0% +transitions to light energy back and +forth back but this right here + + align:start position:0% +forth back but this right here + + + align:start position:0% +forth back but this right here +i'm just saying look okay n equal just + + align:start position:0% +i'm just saying look okay n equal just + + + align:start position:0% +i'm just saying look okay n equal just +keep going n equals three + + align:start position:0% +keep going n equals three + + + align:start position:0% +keep going n equals three +n equals four n equals five so what i + + align:start position:0% +n equals four n equals five so what i + + + align:start position:0% +n equals four n equals five so what i +just asked you is i said well look + + align:start position:0% +just asked you is i said well look + + + align:start position:0% +just asked you is i said well look +some atom has + + align:start position:0% +some atom has + + + align:start position:0% +some atom has +a transition between n equals four and + + align:start position:0% +a transition between n equals four and + + + align:start position:0% +a transition between n equals four and +equals five that means that + + align:start position:0% +equals five that means that + + + align:start position:0% +equals five that means that +if an electron happens to be here it can + + align:start position:0% +if an electron happens to be here it can + + + align:start position:0% +if an electron happens to be here it can +absorb + + align:start position:0% +absorb + + + align:start position:0% +absorb +energy to promote it up to here of + + align:start position:0% +energy to promote it up to here of + + + align:start position:0% +energy to promote it up to here of +exactly 2.75 ev + + align:start position:0% +exactly 2.75 ev + + + align:start position:0% +exactly 2.75 ev +well i can use bore i can use bore now + + align:start position:0% +well i can use bore i can use bore now + + + align:start position:0% +well i can use bore i can use bore now +right because + + align:start position:0% +right because + + + align:start position:0% +right because +so i can actually answer this problem + + align:start position:0% +so i can actually answer this problem + + + align:start position:0% +so i can actually answer this problem +answer this question if i know that + + align:start position:0% +answer this question if i know that + + + align:start position:0% +answer this question if i know that +then i can say well okay if the initial + + align:start position:0% +then i can say well okay if the initial + + + align:start position:0% +then i can say well okay if the initial +state is + + align:start position:0% +state is + + + align:start position:0% +state is +four and the final state is five right + + align:start position:0% +four and the final state is five right + + + align:start position:0% +four and the final state is five right +i've gone from four to five i've + + align:start position:0% +i've gone from four to five i've + + + align:start position:0% +i've gone from four to five i've +promoted an electron + + align:start position:0% +promoted an electron + + + align:start position:0% +promoted an electron +up in energy lifting it up like a ball + + align:start position:0% +up in energy lifting it up like a ball + + + align:start position:0% +up in energy lifting it up like a ball +against gravity + + align:start position:0% +against gravity + + + align:start position:0% +against gravity +all right then if then i can use boar to + + align:start position:0% +all right then if then i can use boar to + + + align:start position:0% +all right then if then i can use boar to +say that 2.75 + + align:start position:0% +say that 2.75 + + + align:start position:0% +say that 2.75 +ev is equal to minus 13.6 + + align:start position:0% +ev is equal to minus 13.6 + + + align:start position:0% +ev is equal to minus 13.6 +z squared times 1 over 5 + + align:start position:0% +z squared times 1 over 5 + + + align:start position:0% +z squared times 1 over 5 +squared minus 1 over 4 squared + + align:start position:0% +squared minus 1 over 4 squared + + + align:start position:0% +squared minus 1 over 4 squared +that would be the transition energy this + + align:start position:0% +that would be the transition energy this + + + align:start position:0% +that would be the transition energy this +dictated by bohr and oh i have + + align:start position:0% +dictated by bohr and oh i have + + + align:start position:0% +dictated by bohr and oh i have +everything except z + + align:start position:0% +everything except z + + + align:start position:0% +everything except z +which i can solve for z equals three + + align:start position:0% +which i can solve for z equals three + + + align:start position:0% +which i can solve for z equals three +z equals three all right so so i've now + + align:start position:0% +z equals three all right so so i've now + + + align:start position:0% +z equals three all right so so i've now +all i need to do is come up with a way + + align:start position:0% +all i need to do is come up with a way + + + align:start position:0% +all i need to do is come up with a way +to coat all the cool + + align:start position:0% +to coat all the cool + + + align:start position:0% +to coat all the cool +leds with lithium right + + align:start position:0% +leds with lithium right + + + align:start position:0% +leds with lithium right +because this is lithium + + align:start position:0% + + + + align:start position:0% + +and we'll be fine except there's a + + align:start position:0% +and we'll be fine except there's a + + + align:start position:0% +and we'll be fine except there's a +problem and this is part of the problem + + align:start position:0% +problem and this is part of the problem + + + align:start position:0% +problem and this is part of the problem +that we need to address and solve today + + align:start position:0% +that we need to address and solve today + + + align:start position:0% +that we need to address and solve today +before the weekend and that is that + + align:start position:0% +before the weekend and that is that + + + align:start position:0% +before the weekend and that is that +see bohr only works + + align:start position:0% +see bohr only works + + + align:start position:0% +see bohr only works +war only works for one electron now it's + + align:start position:0% +war only works for one electron now it's + + + align:start position:0% +war only works for one electron now it's +okay z can be higher + + align:start position:0% +okay z can be higher + + + align:start position:0% +okay z can be higher +z is three and it works here but i've + + align:start position:0% +z is three and it works here but i've + + + align:start position:0% +z is three and it works here but i've +assumed only one + + align:start position:0% +assumed only one + + + align:start position:0% +assumed only one +electron which means this really would + + align:start position:0% +electron which means this really would + + + align:start position:0% +electron which means this really would +be like li-2 plus + + align:start position:0% +be like li-2 plus + + + align:start position:0% +be like li-2 plus +okay we're going to come back to that + + align:start position:0% + + + + align:start position:0% + +but bohr + + align:start position:0% + + + + align:start position:0% + +only for + + align:start position:0% +only for + + + align:start position:0% +only for +one electron + + align:start position:0% +one electron + + + align:start position:0% +one electron +right so so if i'm going to get + + align:start position:0% +right so so if i'm going to get + + + align:start position:0% +right so so if i'm going to get +something like like z + + align:start position:0% +something like like z + + + align:start position:0% +something like like z +is three that's fine but it can only + + align:start position:0% +is three that's fine but it can only + + + align:start position:0% +is three that's fine but it can only +have one electron there + + align:start position:0% +have one electron there + + + align:start position:0% +have one electron there +can only have one electron there or the + + align:start position:0% +can only have one electron there or the + + + align:start position:0% +can only have one electron there or the +model doesn't work it was one electron + + align:start position:0% +model doesn't work it was one electron + + + align:start position:0% +model doesn't work it was one electron +with some z of protons right + + align:start position:0% +with some z of protons right + + + align:start position:0% +with some z of protons right +so this could be li-2 plus that sounds + + align:start position:0% +so this could be li-2 plus that sounds + + + align:start position:0% +so this could be li-2 plus that sounds +harder + + align:start position:0% +harder + + + align:start position:0% +harder +to put into a film okay + + align:start position:0% +to put into a film okay + + + align:start position:0% +to put into a film okay +we will be coming back to this that is a + + align:start position:0% +we will be coming back to this that is a + + + align:start position:0% +we will be coming back to this that is a +serious limitation + + align:start position:0% +serious limitation + + + align:start position:0% +serious limitation +of the bohr model and we can't do a lot + + align:start position:0% +of the bohr model and we can't do a lot + + + align:start position:0% +of the bohr model and we can't do a lot +if we can only do one electron + + align:start position:0% +if we can only do one electron + + + align:start position:0% +if we can only do one electron +right you do a lot of ions + + align:start position:0% +right you do a lot of ions + + + align:start position:0% +right you do a lot of ions +but that's it okay + + align:start position:0% +but that's it okay + + + align:start position:0% +but that's it okay +so i just said the word ion + + align:start position:0% +so i just said the word ion + + + align:start position:0% +so i just said the word ion +what happens now if + + align:start position:0% +what happens now if + + + align:start position:0% +what happens now if +you take an electron not from one level + + align:start position:0% +you take an electron not from one level + + + align:start position:0% +you take an electron not from one level +up in energy but up up up up up all the + + align:start position:0% +up in energy but up up up up up all the + + + align:start position:0% +up in energy but up up up up up all the +way until it's free + + align:start position:0% +way until it's free + + + align:start position:0% +way until it's free +what happens if you do that well that is + + align:start position:0% +what happens if you do that well that is + + + align:start position:0% +what happens if you do that well that is +called ionization + + align:start position:0% +called ionization + + + align:start position:0% +called ionization +that's ionization and in fact when you + + align:start position:0% +that's ionization and in fact when you + + + align:start position:0% +that's ionization and in fact when you +look out into the beautiful world + + align:start position:0% +look out into the beautiful world + + + align:start position:0% +look out into the beautiful world +the universe remember i said on + + align:start position:0% +the universe remember i said on + + + align:start position:0% +the universe remember i said on +wednesday 75 + + align:start position:0% +wednesday 75 + + + align:start position:0% +wednesday 75 +of this is hydrogen a whole lot of it is + + align:start position:0% +of this is hydrogen a whole lot of it is + + + align:start position:0% +of this is hydrogen a whole lot of it is +ionized it's getting ionized + + align:start position:0% +ionized it's getting ionized + + + align:start position:0% +ionized it's getting ionized +from energy that's that's knocking + + align:start position:0% +from energy that's that's knocking + + + align:start position:0% +from energy that's that's knocking +electrons out and then electrons are + + align:start position:0% +electrons out and then electrons are + + + align:start position:0% +electrons out and then electrons are +coming back + + align:start position:0% +coming back + + + align:start position:0% +coming back +and cascading through these levels + + align:start position:0% +and cascading through these levels + + + align:start position:0% +and cascading through these levels +emitting discrete + + align:start position:0% +emitting discrete + + + align:start position:0% +emitting discrete +frequencies of light and this is what + + align:start position:0% +frequencies of light and this is what + + + align:start position:0% +frequencies of light and this is what +you see it's beautiful + + align:start position:0% +you see it's beautiful + + + align:start position:0% +you see it's beautiful +right what you're looking at is ionized + + align:start position:0% +right what you're looking at is ionized + + + align:start position:0% +right what you're looking at is ionized +hydrogen + + align:start position:0% +hydrogen + + + align:start position:0% +hydrogen +getting electrons coming in and + + align:start position:0% +getting electrons coming in and + + + align:start position:0% +getting electrons coming in and +cascading through the bore levels + + align:start position:0% +cascading through the bore levels + + + align:start position:0% +cascading through the bore levels +right ah but what does ionized hydrogen + + align:start position:0% +right ah but what does ionized hydrogen + + + align:start position:0% +right ah but what does ionized hydrogen +mean + + align:start position:0% +mean + + + align:start position:0% +mean +right okay we can now understand it + + align:start position:0% +right okay we can now understand it + + + align:start position:0% +right okay we can now understand it +we can now understand it because now + + align:start position:0% +we can now understand it because now + + + align:start position:0% +we can now understand it because now +instead of going from like four to five + + align:start position:0% +instead of going from like four to five + + + align:start position:0% +instead of going from like four to five +i'm going from anything to infinity it's + + align:start position:0% +i'm going from anything to infinity it's + + + align:start position:0% +i'm going from anything to infinity it's +like escape velocity right + + align:start position:0% +like escape velocity right + + + align:start position:0% +like escape velocity right +it's like how much velocity do i need to + + align:start position:0% +it's like how much velocity do i need to + + + align:start position:0% +it's like how much velocity do i need to +give something so it just gets away + + align:start position:0% +give something so it just gets away + + + align:start position:0% +give something so it just gets away +from the earth and it's not going to + + align:start position:0% +from the earth and it's not going to + + + align:start position:0% +from the earth and it's not going to +feel the earth's + + align:start position:0% +feel the earth's + + + align:start position:0% +feel the earth's +gravitational pull well here i don't + + align:start position:0% +gravitational pull well here i don't + + + align:start position:0% +gravitational pull well here i don't +want this electron to + + align:start position:0% +want this electron to + + + align:start position:0% +want this electron to +feel the potential of the atom anymore + + align:start position:0% +feel the potential of the atom anymore + + + align:start position:0% +feel the potential of the atom anymore +the z the positive charge i want it to + + align:start position:0% +the z the positive charge i want it to + + + align:start position:0% +the z the positive charge i want it to +just be free + + align:start position:0% +just be free + + + align:start position:0% +just be free +that's here that's infinity that's n + + align:start position:0% +that's here that's infinity that's n + + + align:start position:0% +that's here that's infinity that's n +equals infinity + + align:start position:0% +equals infinity + + + align:start position:0% +equals infinity +right so if if i think about this + + align:start position:0% +right so if if i think about this + + + align:start position:0% +right so if if i think about this +that that's actually quite easy to put + + align:start position:0% +that that's actually quite easy to put + + + align:start position:0% +that that's actually quite easy to put +into bohr ionization + + align:start position:0% + + + + align:start position:0% + +energy so + + align:start position:0% +energy so + + + align:start position:0% +energy so +to save time we'll write ie right + + align:start position:0% +to save time we'll write ie right + + + align:start position:0% +to save time we'll write ie right +and this is equal to the energy + + align:start position:0% +and this is equal to the energy + + + align:start position:0% +and this is equal to the energy +required oh i'm going to save time here + + align:start position:0% +required oh i'm going to save time here + + + align:start position:0% +required oh i'm going to save time here +look at that requida + + align:start position:0% +look at that requida + + + align:start position:0% +look at that requida +to remove + + align:start position:0% +to remove + + + align:start position:0% +to remove +the electron from the atom + + align:start position:0% +the electron from the atom + + + align:start position:0% +the electron from the atom +okay good and and if we think about this + + align:start position:0% +okay good and and if we think about this + + + align:start position:0% +okay good and and if we think about this +in terms of bore + + align:start position:0% +in terms of bore + + + align:start position:0% +in terms of bore +it would be like minus 13.6 + + align:start position:0% + + + + align:start position:0% + +let's say for hydrogen because i've got + + align:start position:0% +let's say for hydrogen because i've got + + + align:start position:0% +let's say for hydrogen because i've got +hydrogen up there so for hydrogen + + align:start position:0% +hydrogen up there so for hydrogen + + + align:start position:0% +hydrogen up there so for hydrogen +meaning z equals 1 it'd be minus 13.6 + + align:start position:0% +meaning z equals 1 it'd be minus 13.6 + + + align:start position:0% +meaning z equals 1 it'd be minus 13.6 +times 1 + + align:start position:0% +times 1 + + + align:start position:0% +times 1 +squared that's the z squared right + + align:start position:0% +squared that's the z squared right + + + align:start position:0% +squared that's the z squared right +times 1 over + + align:start position:0% +times 1 over + + + align:start position:0% +times 1 over +nf squared minus 1 over + + align:start position:0% +nf squared minus 1 over + + + align:start position:0% +nf squared minus 1 over +n i squared that's that delta e which + + align:start position:0% +n i squared that's that delta e which + + + align:start position:0% +n i squared that's that delta e which +equals minus 13.6 + + align:start position:0% +equals minus 13.6 + + + align:start position:0% +equals minus 13.6 +times 1 over infinity + + align:start position:0% +times 1 over infinity + + + align:start position:0% +times 1 over infinity +minus 1 over n i squared + + align:start position:0% +minus 1 over n i squared + + + align:start position:0% +minus 1 over n i squared +right now the last i checked with my + + align:start position:0% +right now the last i checked with my + + + align:start position:0% +right now the last i checked with my +colleagues in the math department that's + + align:start position:0% +colleagues in the math department that's + + + align:start position:0% +colleagues in the math department that's +zero + + align:start position:0% +zero + + + align:start position:0% +zero +that's zero right so the ionization + + align:start position:0% +that's zero right so the ionization + + + align:start position:0% +that's zero right so the ionization +energy + + align:start position:0% +energy + + + align:start position:0% +energy +you literally can just read off here if + + align:start position:0% +you literally can just read off here if + + + align:start position:0% +you literally can just read off here if +an electron is in the ground + + align:start position:0% +an electron is in the ground + + + align:start position:0% +an electron is in the ground +state if there's a happy electron right + + align:start position:0% +state if there's a happy electron right + + + align:start position:0% +state if there's a happy electron right +here in this orbital + + align:start position:0% +here in this orbital + + + align:start position:0% +here in this orbital +the amount of energy i need to input + + align:start position:0% +the amount of energy i need to input + + + align:start position:0% +the amount of energy i need to input +into that atom + + align:start position:0% +into that atom + + + align:start position:0% +into that atom +to knock the electron fully out the + + align:start position:0% +to knock the electron fully out the + + + align:start position:0% +to knock the electron fully out the +ionization energy + + align:start position:0% +ionization energy + + + align:start position:0% +ionization energy +is 13.6 electron volts right it's just + + align:start position:0% +is 13.6 electron volts right it's just + + + align:start position:0% +is 13.6 electron volts right it's just +the energy of that orbital + + align:start position:0% +the energy of that orbital + + + align:start position:0% +the energy of that orbital +i could get a little fancier i could say + + align:start position:0% +i could get a little fancier i could say + + + align:start position:0% +i could get a little fancier i could say +well + + align:start position:0% +well + + + align:start position:0% +well +okay what about this question + + align:start position:0% +okay what about this question + + + align:start position:0% +okay what about this question +what if i had light with a hundred + + align:start position:0% +what if i had light with a hundred + + + align:start position:0% +what if i had light with a hundred +nanometers + + align:start position:0% +nanometers + + + align:start position:0% +nanometers +so now i'm telling you my source right + + align:start position:0% +so now i'm telling you my source right + + + align:start position:0% +so now i'm telling you my source right +before i didn't tell you + + align:start position:0% +before i didn't tell you + + + align:start position:0% +before i didn't tell you +something goes into it and knocks it all + + align:start position:0% +something goes into it and knocks it all + + + align:start position:0% +something goes into it and knocks it all +out no now i know what's going in + + align:start position:0% +out no now i know what's going in + + + align:start position:0% +out no now i know what's going in +the the uh the wavelength or the energy + + align:start position:0% +the the uh the wavelength or the energy + + + align:start position:0% +the the uh the wavelength or the energy +of the photons is a hundred nanometers + + align:start position:0% +of the photons is a hundred nanometers + + + align:start position:0% +of the photons is a hundred nanometers +and i'm shining that on hydrogen well + + align:start position:0% +and i'm shining that on hydrogen well + + + align:start position:0% +and i'm shining that on hydrogen well +now okay let's see here so let's stop oh + + align:start position:0% +now okay let's see here so let's stop oh + + + align:start position:0% +now okay let's see here so let's stop oh +i'm asking a question what's the + + align:start position:0% +i'm asking a question what's the + + + align:start position:0% +i'm asking a question what's the +question what is the lowest energy level + + align:start position:0% +question what is the lowest energy level + + + align:start position:0% +question what is the lowest energy level +that the electron could be in such that + + align:start position:0% +that the electron could be in such that + + + align:start position:0% +that the electron could be in such that +a photon from this light source + + align:start position:0% +a photon from this light source + + + align:start position:0% +a photon from this light source +ionizes the atom okay let's see + + align:start position:0% +ionizes the atom okay let's see + + + align:start position:0% +ionizes the atom okay let's see +because i now i now know the pieces and + + align:start position:0% +because i now i now know the pieces and + + + align:start position:0% +because i now i now know the pieces and +i know the definition + + align:start position:0% +i know the definition + + + align:start position:0% +i know the definition +right so now if i have the energy + + align:start position:0% +right so now if i have the energy + + + align:start position:0% +right so now if i have the energy +of a hundred nanometer photon + + align:start position:0% +of a hundred nanometer photon + + + align:start position:0% +of a hundred nanometer photon +well that i'm not going to go through it + + align:start position:0% +well that i'm not going to go through it + + + align:start position:0% +well that i'm not going to go through it +is equal to 12.4 ev + + align:start position:0% +is equal to 12.4 ev + + + align:start position:0% +is equal to 12.4 ev +but see if i now want to use this to + + align:start position:0% +but see if i now want to use this to + + + align:start position:0% +but see if i now want to use this to +ionize hydrogen + + align:start position:0% +ionize hydrogen + + + align:start position:0% +ionize hydrogen +then i get something like this i get + + align:start position:0% +then i get something like this i get + + + align:start position:0% +then i get something like this i get +that delta e + + align:start position:0% +that delta e + + + align:start position:0% +that delta e +equals minus 13.6 + + align:start position:0% +equals minus 13.6 + + + align:start position:0% +equals minus 13.6 +okay times + + align:start position:0% + + + + align:start position:0% + +uh one over infinity squared okay fine + + align:start position:0% +uh one over infinity squared okay fine + + + align:start position:0% +uh one over infinity squared okay fine +we'll keep that for a sec + + align:start position:0% +we'll keep that for a sec + + + align:start position:0% +we'll keep that for a sec +minus one over n i squared right + + align:start position:0% +minus one over n i squared right + + + align:start position:0% +minus one over n i squared right +this is how much this is how much uh uh + + align:start position:0% +this is how much this is how much uh uh + + + align:start position:0% +this is how much this is how much uh uh +delta + + align:start position:0% +delta + + + align:start position:0% +delta +i need to ionize from any given place + + align:start position:0% +i need to ionize from any given place + + + align:start position:0% +i need to ionize from any given place +any + + align:start position:0% +any + + + align:start position:0% +any +given energy level and i right + + align:start position:0% +given energy level and i right + + + align:start position:0% +given energy level and i right +okay but but i have 12. so what if i set + + align:start position:0% +okay but but i have 12. so what if i set + + + align:start position:0% +okay but but i have 12. so what if i set +this equal to 12 + + align:start position:0% +this equal to 12 + + + align:start position:0% +this equal to 12 +right if i set this equal to 12.4 that's + + align:start position:0% +right if i set this equal to 12.4 that's + + + align:start position:0% +right if i set this equal to 12.4 that's +what i have + + align:start position:0% +what i have + + + align:start position:0% +what i have +then what i get is n i + + align:start position:0% +then what i get is n i + + + align:start position:0% +then what i get is n i +equals 1.05 + + align:start position:0% +equals 1.05 + + + align:start position:0% +equals 1.05 +okay good that's my answer + + align:start position:0% + + + + align:start position:0% + +no panic everybody should be panicking + + align:start position:0% +no panic everybody should be panicking + + + align:start position:0% +no panic everybody should be panicking +no that can't be my answer + + align:start position:0% +no that can't be my answer + + + align:start position:0% +no that can't be my answer +i can't i can't have something that's + + align:start position:0% +i can't i can't have something that's + + + align:start position:0% +i can't i can't have something that's +not an integer + + align:start position:0% +not an integer + + + align:start position:0% +not an integer +because i said it over there that n is a + + align:start position:0% +because i said it over there that n is a + + + align:start position:0% +because i said it over there that n is a +quantum number + + align:start position:0% +quantum number + + + align:start position:0% +quantum number +one two three nothing is allowed in + + align:start position:0% +one two three nothing is allowed in + + + align:start position:0% +one two three nothing is allowed in +between + + align:start position:0% +between + + + align:start position:0% +between +so what you can see is that i got so + + align:start position:0% +so what you can see is that i got so + + + align:start position:0% +so what you can see is that i got so +close + + align:start position:0% +close + + + align:start position:0% +close +i almost had enough energy to get n to + + align:start position:0% +i almost had enough energy to get n to + + + align:start position:0% +i almost had enough energy to get n to +b1 but i don't + + align:start position:0% +b1 but i don't + + + align:start position:0% +b1 but i don't +so i cannot use this light to ionize an + + align:start position:0% +so i cannot use this light to ionize an + + + align:start position:0% +so i cannot use this light to ionize an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +in n equals one i can't but i could use + + align:start position:0% +in n equals one i can't but i could use + + + align:start position:0% +in n equals one i can't but i could use +it to ionize an electron in n equals two + + align:start position:0% + + + + align:start position:0% + +right because there if n is two + + align:start position:0% +right because there if n is two + + + align:start position:0% +right because there if n is two +well then i've got actually plenty of + + align:start position:0% +well then i've got actually plenty of + + + align:start position:0% +well then i've got actually plenty of +energy + + align:start position:0% +energy + + + align:start position:0% +energy +right so + + align:start position:0% + + + + align:start position:0% + +cannot ionize + + align:start position:0% + + + + align:start position:0% + +from n i equals one + + align:start position:0% +from n i equals one + + + align:start position:0% +from n i equals one +but n i equals two + + align:start position:0% +but n i equals two + + + align:start position:0% +but n i equals two +is okay right so that's the outcome of + + align:start position:0% +is okay right so that's the outcome of + + + align:start position:0% +is okay right so that's the outcome of +this + + align:start position:0% +this + + + align:start position:0% +this +now i could also use that same 12.4 ev + + align:start position:0% +now i could also use that same 12.4 ev + + + align:start position:0% +now i could also use that same 12.4 ev +photon + + align:start position:0% +photon + + + align:start position:0% +photon +to ionize from n equals three or four or + + align:start position:0% +to ionize from n equals three or four or + + + align:start position:0% +to ionize from n equals three or four or +any of these + + align:start position:0% +any of these + + + align:start position:0% +any of these +but i can't get to one and there's one + + align:start position:0% +but i can't get to one and there's one + + + align:start position:0% +but i can't get to one and there's one +other concept that's important because + + align:start position:0% +other concept that's important because + + + align:start position:0% +other concept that's important because +look + + align:start position:0% +look + + + align:start position:0% +look +i gave it 12.4 ev + + align:start position:0% +i gave it 12.4 ev + + + align:start position:0% +i gave it 12.4 ev +what did i actually need well i mean you + + align:start position:0% +what did i actually need well i mean you + + + align:start position:0% +what did i actually need well i mean you +can even see it here + + align:start position:0% +can even see it here + + + align:start position:0% +can even see it here +you can just you know what these levels + + align:start position:0% +you can just you know what these levels + + + align:start position:0% +you can just you know what these levels +are from the bohr model + + align:start position:0% +are from the bohr model + + + align:start position:0% +are from the bohr model +here this is 13.6 this is + + align:start position:0% +here this is 13.6 this is + + + align:start position:0% +here this is 13.6 this is +minus 3.4 okay that's telling me this is + + align:start position:0% +minus 3.4 okay that's telling me this is + + + align:start position:0% +minus 3.4 okay that's telling me this is +definitely not drawn to scale + + align:start position:0% +definitely not drawn to scale + + + align:start position:0% +definitely not drawn to scale +but still you you get the point 3.4 + + align:start position:0% +but still you you get the point 3.4 + + + align:start position:0% +but still you you get the point 3.4 +and and i just said well i could + + align:start position:0% +and and i just said well i could + + + align:start position:0% +and and i just said well i could +probably get it out of 3.4 and i can + + align:start position:0% +probably get it out of 3.4 and i can + + + align:start position:0% +probably get it out of 3.4 and i can +because i've got 12.4 + + align:start position:0% +because i've got 12.4 + + + align:start position:0% +because i've got 12.4 +and so if i did this so if n + + align:start position:0% +and so if i did this so if n + + + align:start position:0% +and so if i did this so if n +i equals two then i would have excess + + align:start position:0% +i equals two then i would have excess + + + align:start position:0% +i equals two then i would have excess +energy + + align:start position:0% +energy + + + align:start position:0% +energy +excess energy would be nine electron + + align:start position:0% +excess energy would be nine electron + + + align:start position:0% +excess energy would be nine electron +volts + + align:start position:0% +volts + + + align:start position:0% +volts +and that is kinetic right so i've shot + + align:start position:0% +and that is kinetic right so i've shot + + + align:start position:0% +and that is kinetic right so i've shot +this thing out of the atom + + align:start position:0% +this thing out of the atom + + + align:start position:0% +this thing out of the atom +with light that's got way more energy + + align:start position:0% +with light that's got way more energy + + + align:start position:0% +with light that's got way more energy +than i needed to ionize it but that + + align:start position:0% +than i needed to ionize it but that + + + align:start position:0% +than i needed to ionize it but that +energy didn't it's still in the electron + + align:start position:0% +energy didn't it's still in the electron + + + align:start position:0% +energy didn't it's still in the electron +i transferred that photon energy to the + + align:start position:0% +i transferred that photon energy to the + + + align:start position:0% +i transferred that photon energy to the +electron energy + + align:start position:0% +electron energy + + + align:start position:0% +electron energy +and so that is going to be + + align:start position:0% +and so that is going to be + + + align:start position:0% +and so that is going to be +in the kinetic energy of + + align:start position:0% +in the kinetic energy of + + + align:start position:0% +in the kinetic energy of +the electron that's now free the + + align:start position:0% +the electron that's now free the + + + align:start position:0% +the electron that's now free the +electron free + + align:start position:0% +electron free + + + align:start position:0% +electron free +i should have said free electron right + + align:start position:0% +i should have said free electron right + + + align:start position:0% +i should have said free electron right +excess kinetic energy comes after + + align:start position:0% +excess kinetic energy comes after + + + align:start position:0% +excess kinetic energy comes after +ionizing it right so these things + + align:start position:0% +ionizing it right so these things + + + align:start position:0% +ionizing it right so these things +are the things we can do with bohr so i + + align:start position:0% +are the things we can do with bohr so i + + + align:start position:0% +are the things we can do with bohr so i +wanted to kind of + + align:start position:0% +wanted to kind of + + + align:start position:0% +wanted to kind of +you know take what we learned wednesday + + align:start position:0% +you know take what we learned wednesday + + + align:start position:0% +you know take what we learned wednesday +and apply it to a few problems + + align:start position:0% +and apply it to a few problems + + + align:start position:0% +and apply it to a few problems +and go back and forth with + + align:start position:0% +and go back and forth with + + + align:start position:0% +and go back and forth with +with this idea of photon energy uh + + align:start position:0% +with this idea of photon energy uh + + + align:start position:0% +with this idea of photon energy uh +to bore level changes and that's what i + + align:start position:0% +to bore level changes and that's what i + + + align:start position:0% +to bore level changes and that's what i +want you to do in + + align:start position:0% +want you to do in + + + align:start position:0% +want you to do in +this week's goodie bag as well okay + + align:start position:0% +this week's goodie bag as well okay + + + align:start position:0% +this week's goodie bag as well okay +now ionization is an important concept + + align:start position:0% +now ionization is an important concept + + + align:start position:0% +now ionization is an important concept +like i said we'll be coming back to it + + align:start position:0% +like i said we'll be coming back to it + + + align:start position:0% +like i said we'll be coming back to it +um and you can you can actually uh + + align:start position:0% +um and you can you can actually uh + + + align:start position:0% +um and you can you can actually uh +plot and many people have measured and + + align:start position:0% +plot and many people have measured and + + + align:start position:0% +plot and many people have measured and +and this is very important + + align:start position:0% +and this is very important + + + align:start position:0% +and this is very important +the ionization energy of elements like + + align:start position:0% +the ionization energy of elements like + + + align:start position:0% +the ionization energy of elements like +as a function of + + align:start position:0% +as a function of + + + align:start position:0% +as a function of +atomic number and the first ionization + + align:start position:0% +atomic number and the first ionization + + + align:start position:0% +atomic number and the first ionization +energy + + align:start position:0% +energy + + + align:start position:0% +energy +is important right the first ionization + + align:start position:0% +is important right the first ionization + + + align:start position:0% +is important right the first ionization +energy is the energy + + align:start position:0% +energy is the energy + + + align:start position:0% +energy is the energy +required to remove the outermost + + align:start position:0% +required to remove the outermost + + + align:start position:0% +required to remove the outermost +electron right + + align:start position:0% +electron right + + + align:start position:0% +electron right +right so if i did have a whole bunch of + + align:start position:0% +right so if i did have a whole bunch of + + + align:start position:0% +right so if i did have a whole bunch of +of electrons so if i had + + align:start position:0% +of electrons so if i had + + + align:start position:0% +of electrons so if i had +a whole bunch of electrons the first + + align:start position:0% +a whole bunch of electrons the first + + + align:start position:0% +a whole bunch of electrons the first +ionization the first + + align:start position:0% + + + + align:start position:0% + +ionization energy is the energy + + align:start position:0% +ionization energy is the energy + + + align:start position:0% +ionization energy is the energy +required + + align:start position:0% + + + + align:start position:0% + +to remove the outermost one + + align:start position:0% + + + + align:start position:0% + +so that's an important number to know if + + align:start position:0% +so that's an important number to know if + + + align:start position:0% +so that's an important number to know if +you want to take an electron off of an + + align:start position:0% +you want to take an electron off of an + + + align:start position:0% +you want to take an electron off of an +atom + + align:start position:0% +atom + + + align:start position:0% +atom +and we will be doing that because that's + + align:start position:0% +and we will be doing that because that's + + + align:start position:0% +and we will be doing that because that's +how we're going to make our first + + align:start position:0% +how we're going to make our first + + + align:start position:0% +how we're going to make our first +bond next week if you want to take an + + align:start position:0% +bond next week if you want to take an + + + align:start position:0% +bond next week if you want to take an +electron off an atom this is one of the + + align:start position:0% +electron off an atom this is one of the + + + align:start position:0% +electron off an atom this is one of the +first things you ask + + align:start position:0% +first things you ask + + + align:start position:0% +first things you ask +how much energy does it take right how + + align:start position:0% +how much energy does it take right how + + + align:start position:0% +how much energy does it take right how +much energy does it take so that's an + + align:start position:0% +much energy does it take so that's an + + + align:start position:0% +much energy does it take so that's an +important concept that we'll be coming + + align:start position:0% +important concept that we'll be coming + + + align:start position:0% +important concept that we'll be coming +back to now + + align:start position:0% +back to now + + + align:start position:0% +back to now +okay i alluded to the fact that we + + align:start position:0% +okay i alluded to the fact that we + + + align:start position:0% +okay i alluded to the fact that we +needed a new theory + + align:start position:0% +needed a new theory + + + align:start position:0% +needed a new theory +i already alluded to that and i said + + align:start position:0% +i already alluded to that and i said + + + align:start position:0% +i already alluded to that and i said +that's where we're going today + + align:start position:0% +that's where we're going today + + + align:start position:0% +that's where we're going today +the bohr model works for one electron as + + align:start position:0% +the bohr model works for one electron as + + + align:start position:0% +the bohr model works for one electron as +i said all right that means it's good + + align:start position:0% +i said all right that means it's good + + + align:start position:0% +i said all right that means it's good +for hydrogen + + align:start position:0% +for hydrogen + + + align:start position:0% +for hydrogen +oh we just ionized hydrogen that was a + + align:start position:0% +oh we just ionized hydrogen that was a + + + align:start position:0% +oh we just ionized hydrogen that was a +lot of fun + + align:start position:0% +lot of fun + + + align:start position:0% +lot of fun +and it's good for like he plus + + align:start position:0% +and it's good for like he plus + + + align:start position:0% +and it's good for like he plus +or li2 plus or osmium 75 plus + + align:start position:0% +or li2 plus or osmium 75 plus + + + align:start position:0% +or li2 plus or osmium 75 plus +yeah that's real but what about two + + align:start position:0% +yeah that's real but what about two + + + align:start position:0% +yeah that's real but what about two +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +what about two just two forget about ten + + align:start position:0% +what about two just two forget about ten + + + align:start position:0% +what about two just two forget about ten +twenty thirty + + align:start position:0% +twenty thirty + + + align:start position:0% +twenty thirty +two the bohr model can't do it it + + align:start position:0% +two the bohr model can't do it it + + + align:start position:0% +two the bohr model can't do it it +doesn't + + align:start position:0% +doesn't + + + align:start position:0% +doesn't +it it doesn't work for anything more + + align:start position:0% +it it doesn't work for anything more + + + align:start position:0% +it it doesn't work for anything more +than one electron it was derived for one + + align:start position:0% +than one electron it was derived for one + + + align:start position:0% +than one electron it was derived for one +electron and that's where it stays so + + align:start position:0% +electron and that's where it stays so + + + align:start position:0% +electron and that's where it stays so +we're at this point now + + align:start position:0% +we're at this point now + + + align:start position:0% +we're at this point now +this is a picture i started to draw this + + align:start position:0% +this is a picture i started to draw this + + + align:start position:0% +this is a picture i started to draw this +week on monday and we're at a point + + align:start position:0% +week on monday and we're at a point + + + align:start position:0% +week on monday and we're at a point +where we need something deeper + + align:start position:0% +where we need something deeper + + + align:start position:0% +where we need something deeper +and some of the work that went into this + + align:start position:0% +and some of the work that went into this + + + align:start position:0% +and some of the work that went into this +was really critical + + align:start position:0% +was really critical + + + align:start position:0% +was really critical +and i'm not going to go into too much + + align:start position:0% +and i'm not going to go into too much + + + align:start position:0% +and i'm not going to go into too much +detail but there's one thing i want you + + align:start position:0% +detail but there's one thing i want you + + + align:start position:0% +detail but there's one thing i want you +to know so remember + + align:start position:0% +to know so remember + + + align:start position:0% +to know so remember +you know plank and einstein they were + + align:start position:0% +you know plank and einstein they were + + + align:start position:0% +you know plank and einstein they were +playing with quantization of light + + align:start position:0% +playing with quantization of light + + + align:start position:0% +playing with quantization of light +and einstein's photoelectric effect + + align:start position:0% +and einstein's photoelectric effect + + + align:start position:0% +and einstein's photoelectric effect +found the particle nature of light + + align:start position:0% +found the particle nature of light + + + align:start position:0% +found the particle nature of light +with planks you know with together their + + align:start position:0% +with planks you know with together their + + + align:start position:0% +with planks you know with together their +energy + + align:start position:0% +energy + + + align:start position:0% +energy +right equals h nu that quantized energy + + align:start position:0% +right equals h nu that quantized energy + + + align:start position:0% +right equals h nu that quantized energy +of the photon + + align:start position:0% +of the photon + + + align:start position:0% +of the photon +and they they saw it's a particle but it + + align:start position:0% +and they they saw it's a particle but it + + + align:start position:0% +and they they saw it's a particle but it +also is is a + + align:start position:0% +also is is a + + + align:start position:0% +also is is a +is a wave right there's a lot of + + align:start position:0% +is a wave right there's a lot of + + + align:start position:0% +is a wave right there's a lot of +discussion and + + align:start position:0% +discussion and + + + align:start position:0% +discussion and +and interest and and attempts to + + align:start position:0% +and interest and and attempts to + + + align:start position:0% +and interest and and attempts to +understand + + align:start position:0% +understand + + + align:start position:0% +understand +what it was was it a wave or a particle + + align:start position:0% +what it was was it a wave or a particle + + + align:start position:0% +what it was was it a wave or a particle +and compton did some beautiful + + align:start position:0% +and compton did some beautiful + + + align:start position:0% +and compton did some beautiful +experiments to show again + + align:start position:0% +experiments to show again + + + align:start position:0% +experiments to show again +evidence that it was a particle because + + align:start position:0% +evidence that it was a particle because + + + align:start position:0% +evidence that it was a particle because +he he saw how + + align:start position:0% +he he saw how + + + align:start position:0% +he he saw how +light interacted with electrons and it + + align:start position:0% +light interacted with electrons and it + + + align:start position:0% +light interacted with electrons and it +was like this collision + + align:start position:0% +was like this collision + + + align:start position:0% +was like this collision +that particles do and then de broglie + + align:start position:0% +that particles do and then de broglie + + + align:start position:0% +that particles do and then de broglie +or as where's jerome de bruyne + + align:start position:0% +or as where's jerome de bruyne + + + align:start position:0% +or as where's jerome de bruyne +i don't know would say he went + + align:start position:0% +i don't know would say he went + + + align:start position:0% +i don't know would say he went +further de broglie went further he said + + align:start position:0% +further de broglie went further he said + + + align:start position:0% +further de broglie went further he said +everything is both light you guys don't + + align:start position:0% +everything is both light you guys don't + + + align:start position:0% +everything is both light you guys don't +know if light is a particle or wave well + + align:start position:0% +know if light is a particle or wave well + + + align:start position:0% +know if light is a particle or wave well +i'm saying everything is a wave + + align:start position:0% +i'm saying everything is a wave + + + align:start position:0% +i'm saying everything is a wave +everything and everything has this + + align:start position:0% +everything and everything has this + + + align:start position:0% +everything and everything has this +duality + + align:start position:0% +duality + + + align:start position:0% +duality +so he wrote something very important + + align:start position:0% +so he wrote something very important + + + align:start position:0% +so he wrote something very important +which is + + align:start position:0% +which is + + + align:start position:0% +which is +the relationship between anything's + + align:start position:0% +the relationship between anything's + + + align:start position:0% +the relationship between anything's +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +and it's wavelength so we'll come back + + align:start position:0% +and it's wavelength so we'll come back + + + align:start position:0% +and it's wavelength so we'll come back +to this so i want to write it down so + + align:start position:0% +to this so i want to write it down so + + + align:start position:0% +to this so i want to write it down so +de brush he said + + align:start position:0% + + + + align:start position:0% + +that the wavelength of anything can be + + align:start position:0% +that the wavelength of anything can be + + + align:start position:0% +that the wavelength of anything can be +written + + align:start position:0% +written + + + align:start position:0% +written +as oh that same quantization number + + align:start position:0% +as oh that same quantization number + + + align:start position:0% +as oh that same quantization number +constant from planck divided by its + + align:start position:0% +constant from planck divided by its + + + align:start position:0% +constant from planck divided by its +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +literally just its momentum anything has + + align:start position:0% +literally just its momentum anything has + + + align:start position:0% +literally just its momentum anything has +a wave nature + + align:start position:0% +a wave nature + + + align:start position:0% +a wave nature +anything and light has a particle nature + + align:start position:0% +anything and light has a particle nature + + + align:start position:0% +anything and light has a particle nature +what's going on + + align:start position:0% +what's going on + + + align:start position:0% +what's going on +and it led einstein to say at the time + + align:start position:0% +and it led einstein to say at the time + + + align:start position:0% +and it led einstein to say at the time +he said quote it seems as though we must + + align:start position:0% +he said quote it seems as though we must + + + align:start position:0% +he said quote it seems as though we must +use sometimes the one theory and + + align:start position:0% +use sometimes the one theory and + + + align:start position:0% +use sometimes the one theory and +sometimes the other + + align:start position:0% +sometimes the other + + + align:start position:0% +sometimes the other +while at times we may use either we are + + align:start position:0% +while at times we may use either we are + + + align:start position:0% +while at times we may use either we are +faced with a new kind of difficulty we + + align:start position:0% +faced with a new kind of difficulty we + + + align:start position:0% +faced with a new kind of difficulty we +have two contradictory pictures of + + align:start position:0% +have two contradictory pictures of + + + align:start position:0% +have two contradictory pictures of +reality + + align:start position:0% +reality + + + align:start position:0% +reality +separately neither of them fully + + align:start position:0% +separately neither of them fully + + + align:start position:0% +separately neither of them fully +explains the phenomena of light + + align:start position:0% +explains the phenomena of light + + + align:start position:0% +explains the phenomena of light +but together they do this was the + + align:start position:0% +but together they do this was the + + + align:start position:0% +but together they do this was the +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +of quantum mechanics this is where they + + align:start position:0% +of quantum mechanics this is where they + + + align:start position:0% +of quantum mechanics this is where they +were + + align:start position:0% + + + + align:start position:0% + +and and later once they once they really + + align:start position:0% +and and later once they once they really + + + align:start position:0% +and and later once they once they really +got the quantum mechanics kind of going + + align:start position:0% +got the quantum mechanics kind of going + + + align:start position:0% +got the quantum mechanics kind of going +he said this the more success the + + align:start position:0% +he said this the more success the + + + align:start position:0% +he said this the more success the +quantum mechanics has the sillier it + + align:start position:0% +quantum mechanics has the sillier it + + + align:start position:0% +quantum mechanics has the sillier it +looks + + align:start position:0% +looks + + + align:start position:0% +looks +why well there's only one way + + align:start position:0% +why well there's only one way + + + align:start position:0% +why well there's only one way +uh to really learn about quantum + + align:start position:0% +uh to really learn about quantum + + + align:start position:0% +uh to really learn about quantum +especially if it's the first time and + + align:start position:0% +especially if it's the first time and + + + align:start position:0% +especially if it's the first time and +that's from dr quantum himself + + align:start position:0% +that's from dr quantum himself + + + align:start position:0% +that's from dr quantum himself +and so i do have a video of dr quanum + + align:start position:0% +and so i do have a video of dr quanum + + + align:start position:0% +and so i do have a video of dr quanum +and i'm hoping you will enjoy this with + + align:start position:0% +and i'm hoping you will enjoy this with + + + align:start position:0% +and i'm hoping you will enjoy this with +me i enjoy it every time i see it + + align:start position:0% +me i enjoy it every time i see it + + + align:start position:0% +me i enjoy it every time i see it +most friday nights um so + + align:start position:0% +most friday nights um so + + + align:start position:0% +most friday nights um so +let's watch dr quantum explain + + align:start position:0% +let's watch dr quantum explain + + + align:start position:0% +let's watch dr quantum explain +because there was one really important + + align:start position:0% +because there was one really important + + + align:start position:0% +because there was one really important +experiment + + align:start position:0% + + + + align:start position:0% + +that happened that he's going to explain + + align:start position:0% +that happened that he's going to explain + + + align:start position:0% +that happened that he's going to explain +right now called the double slit + + align:start position:0% +right now called the double slit + + + align:start position:0% +right now called the double slit +experiment and it changed everything + + align:start position:0% +experiment and it changed everything + + + align:start position:0% +experiment and it changed everything +and i don't care if you see it in + + align:start position:0% +and i don't care if you see it in + + + align:start position:0% +and i don't care if you see it in +another class we're seeing it here + + align:start position:0% +another class we're seeing it here + + + align:start position:0% +another class we're seeing it here +because this sets up + + align:start position:0% +because this sets up + + + align:start position:0% +because this sets up +what happens next in chemistry let's + + align:start position:0% +what happens next in chemistry let's + + + align:start position:0% +what happens next in chemistry let's +watch dr quantum + + align:start position:0% +watch dr quantum + + + align:start position:0% +watch dr quantum +we are the granddaddy of all quantum + + align:start position:0% +we are the granddaddy of all quantum + + + align:start position:0% +we are the granddaddy of all quantum +weirdness + + align:start position:0% +weirdness + + + align:start position:0% +weirdness +the infamous double slit experiment + + align:start position:0% +the infamous double slit experiment + + + align:start position:0% +the infamous double slit experiment +to understand this experiment we first + + align:start position:0% +to understand this experiment we first + + + align:start position:0% +to understand this experiment we first +need to see + + align:start position:0% +need to see + + + align:start position:0% +need to see +how particles or little balls of matter + + align:start position:0% +how particles or little balls of matter + + + align:start position:0% +how particles or little balls of matter +act if we randomly shoot a small + + align:start position:0% +act if we randomly shoot a small + + + align:start position:0% +act if we randomly shoot a small +object say a marble at the screen + + align:start position:0% +object say a marble at the screen + + + align:start position:0% +object say a marble at the screen +we see a pattern on the back wall where + + align:start position:0% +we see a pattern on the back wall where + + + align:start position:0% +we see a pattern on the back wall where +they went through the slit + + align:start position:0% +they went through the slit + + + align:start position:0% +they went through the slit +and hit now if we add a second slit + + align:start position:0% +and hit now if we add a second slit + + + align:start position:0% +and hit now if we add a second slit +we would expect to see a second band + + align:start position:0% +we would expect to see a second band + + + align:start position:0% +we would expect to see a second band +duplicated + + align:start position:0% +duplicated + + + align:start position:0% +duplicated +to the right + + align:start position:0% + + + + align:start position:0% + +now let's look at waves + + align:start position:0% +now let's look at waves + + + align:start position:0% +now let's look at waves +the waves hit the slit and radiate out + + align:start position:0% +the waves hit the slit and radiate out + + + align:start position:0% +the waves hit the slit and radiate out +striking the back wall with the most + + align:start position:0% +striking the back wall with the most + + + align:start position:0% +striking the back wall with the most +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +directly in line with the slit + + align:start position:0% +directly in line with the slit + + + align:start position:0% +directly in line with the slit +the line of brightness on the back + + align:start position:0% +the line of brightness on the back + + + align:start position:0% +the line of brightness on the back +screen shows that intensity + + align:start position:0% +screen shows that intensity + + + align:start position:0% +screen shows that intensity +this is similar to the line the marbles + + align:start position:0% +this is similar to the line the marbles + + + align:start position:0% +this is similar to the line the marbles +make + + align:start position:0% +make + + + align:start position:0% +make +but when we add the second slit + + align:start position:0% +but when we add the second slit + + + align:start position:0% +but when we add the second slit +something different happens if the top + + align:start position:0% +something different happens if the top + + + align:start position:0% +something different happens if the top +of one wave + + align:start position:0% +of one wave + + + align:start position:0% +of one wave +meets the bottom of another wave + + align:start position:0% +meets the bottom of another wave + + + align:start position:0% +meets the bottom of another wave +they cancel each other out so now + + align:start position:0% +they cancel each other out so now + + + align:start position:0% +they cancel each other out so now +there is an interference pattern on the + + align:start position:0% +there is an interference pattern on the + + + align:start position:0% +there is an interference pattern on the +back wall + + align:start position:0% +back wall + + + align:start position:0% +back wall +places where the two tops meet are the + + align:start position:0% +places where the two tops meet are the + + + align:start position:0% +places where the two tops meet are the +highest intensity + + align:start position:0% +highest intensity + + + align:start position:0% +highest intensity +the bright lines and where they cancel + + align:start position:0% +the bright lines and where they cancel + + + align:start position:0% +the bright lines and where they cancel +there is nothing + + align:start position:0% +there is nothing + + + align:start position:0% +there is nothing +so when we throw things + + align:start position:0% +so when we throw things + + + align:start position:0% +so when we throw things +that is matter through two slits + + align:start position:0% +that is matter through two slits + + + align:start position:0% +that is matter through two slits +we get this two bands of hits + + align:start position:0% +we get this two bands of hits + + + align:start position:0% +we get this two bands of hits +and with waves we get an interference + + align:start position:0% +and with waves we get an interference + + + align:start position:0% +and with waves we get an interference +pattern + + align:start position:0% +pattern + + + align:start position:0% +pattern +of many bands good + + align:start position:0% +of many bands good + + + align:start position:0% +of many bands good +so far now let's go + + align:start position:0% +so far now let's go + + + align:start position:0% +so far now let's go +quantum my favorite line i love that + + align:start position:0% +quantum my favorite line i love that + + + align:start position:0% +quantum my favorite line i love that +line + + align:start position:0% + + + + align:start position:0% + +an electron is a tiny tiny bit + + align:start position:0% +an electron is a tiny tiny bit + + + align:start position:0% +an electron is a tiny tiny bit +of matter like a tiny marble + + align:start position:0% +of matter like a tiny marble + + + align:start position:0% +of matter like a tiny marble +let's fire a stream through one slit + + align:start position:0% +let's fire a stream through one slit + + + align:start position:0% +let's fire a stream through one slit +it behaves just like the marble a single + + align:start position:0% +it behaves just like the marble a single + + + align:start position:0% +it behaves just like the marble a single +band + + align:start position:0% +band + + + align:start position:0% +band +so if we shoot these tiny bits through + + align:start position:0% +so if we shoot these tiny bits through + + + align:start position:0% +so if we shoot these tiny bits through +two slits we should get like the marbles + + align:start position:0% +two slits we should get like the marbles + + + align:start position:0% +two slits we should get like the marbles +two bands what + + align:start position:0% +two bands what + + + align:start position:0% +two bands what +an interference pattern we fired + + align:start position:0% +an interference pattern we fired + + + align:start position:0% +an interference pattern we fired +electrons tiny bits of matter through + + align:start position:0% +electrons tiny bits of matter through + + + align:start position:0% +electrons tiny bits of matter through +but we get a pattern like waves not like + + align:start position:0% +but we get a pattern like waves not like + + + align:start position:0% +but we get a pattern like waves not like +little marbles + + align:start position:0% +little marbles + + + align:start position:0% +little marbles +how how could pieces of matter + + align:start position:0% +how how could pieces of matter + + + align:start position:0% +how how could pieces of matter +create an interference pattern like a + + align:start position:0% +create an interference pattern like a + + + align:start position:0% +create an interference pattern like a +wave + + align:start position:0% +wave + + + align:start position:0% +wave +it doesn't make sense but + + align:start position:0% +it doesn't make sense but + + + align:start position:0% +it doesn't make sense but +physicists are clever they thought maybe + + align:start position:0% +physicists are clever they thought maybe + + + align:start position:0% +physicists are clever they thought maybe +those little balls are bouncing off each + + align:start position:0% +those little balls are bouncing off each + + + align:start position:0% +those little balls are bouncing off each +other + + align:start position:0% +other + + + align:start position:0% +other +and creating that pattern so + + align:start position:0% +and creating that pattern so + + + align:start position:0% +and creating that pattern so +they decide to shoot electrons through + + align:start position:0% +they decide to shoot electrons through + + + align:start position:0% +they decide to shoot electrons through +one at a time + + align:start position:0% +one at a time + + + align:start position:0% +one at a time +there is no way they can interfere with + + align:start position:0% +there is no way they can interfere with + + + align:start position:0% +there is no way they can interfere with +each other + + align:start position:0% +each other + + + align:start position:0% +each other +but after an hour of this the same + + align:start position:0% +but after an hour of this the same + + + align:start position:0% +but after an hour of this the same +interference pattern is seen to emerge + + align:start position:0% +interference pattern is seen to emerge + + + align:start position:0% +interference pattern is seen to emerge +the conclusion is inescapable the single + + align:start position:0% +the conclusion is inescapable the single + + + align:start position:0% +the conclusion is inescapable the single +electron + + align:start position:0% +electron + + + align:start position:0% +electron +leaves as a particle becomes a wave of + + align:start position:0% +leaves as a particle becomes a wave of + + + align:start position:0% +leaves as a particle becomes a wave of +potentials + + align:start position:0% +potentials + + + align:start position:0% +potentials +goes through both slits and interferes + + align:start position:0% +goes through both slits and interferes + + + align:start position:0% +goes through both slits and interferes +with itself to hit the wall like a + + align:start position:0% +with itself to hit the wall like a + + + align:start position:0% +with itself to hit the wall like a +particle + + align:start position:0% +particle + + + align:start position:0% +particle +but mathematically it's even stranger it + + align:start position:0% +but mathematically it's even stranger it + + + align:start position:0% +but mathematically it's even stranger it +goes through both slits + + align:start position:0% +goes through both slits + + + align:start position:0% +goes through both slits +and it goes through neither and it goes + + align:start position:0% +and it goes through neither and it goes + + + align:start position:0% +and it goes through neither and it goes +through just one + + align:start position:0% +through just one + + + align:start position:0% +through just one +and it goes through just the other all + + align:start position:0% +and it goes through just the other all + + + align:start position:0% +and it goes through just the other all +of these possibilities + + align:start position:0% +of these possibilities + + + align:start position:0% +of these possibilities +are in superposition with each other but + + align:start position:0% +are in superposition with each other but + + + align:start position:0% +are in superposition with each other but +physicists were completely baffled by + + align:start position:0% +physicists were completely baffled by + + + align:start position:0% +physicists were completely baffled by +this + + align:start position:0% +this + + + align:start position:0% +this +so they decided to peek and see which + + align:start position:0% +so they decided to peek and see which + + + align:start position:0% +so they decided to peek and see which +slit + + align:start position:0% +slit + + + align:start position:0% +slit +it actually goes through + + align:start position:0% +it actually goes through + + + align:start position:0% +it actually goes through +they put a measuring device by one slip + + align:start position:0% +they put a measuring device by one slip + + + align:start position:0% +they put a measuring device by one slip +to see which one it went through + + align:start position:0% +to see which one it went through + + + align:start position:0% +to see which one it went through +and let it fly + + align:start position:0% + + + + align:start position:0% + +but the quantum world is far more + + align:start position:0% +but the quantum world is far more + + + align:start position:0% +but the quantum world is far more +mysterious than they could have imagined + + align:start position:0% +mysterious than they could have imagined + + + align:start position:0% +mysterious than they could have imagined +when they observed the electron went + + align:start position:0% +when they observed the electron went + + + align:start position:0% +when they observed the electron went +back + + align:start position:0% +back + + + align:start position:0% +back +to behaving like a little marble it + + align:start position:0% +to behaving like a little marble it + + + align:start position:0% +to behaving like a little marble it +produced a pattern of two + + align:start position:0% +produced a pattern of two + + + align:start position:0% +produced a pattern of two +bands not an interference pattern of + + align:start position:0% +bands not an interference pattern of + + + align:start position:0% +bands not an interference pattern of +many + + align:start position:0% +many + + + align:start position:0% +many +the very act of measuring + + align:start position:0% +the very act of measuring + + + align:start position:0% +the very act of measuring +or observing which slit it went through + + align:start position:0% +or observing which slit it went through + + + align:start position:0% +or observing which slit it went through +meant it only went through one not both + + align:start position:0% +meant it only went through one not both + + + align:start position:0% +meant it only went through one not both +the electron decided to act + + align:start position:0% +the electron decided to act + + + align:start position:0% +the electron decided to act +differently though it was aware + + align:start position:0% +differently though it was aware + + + align:start position:0% +differently though it was aware +it was being watched and it was here + + align:start position:0% +it was being watched and it was here + + + align:start position:0% +it was being watched and it was here +that physicists stepped forever into the + + align:start position:0% +that physicists stepped forever into the + + + align:start position:0% +that physicists stepped forever into the +strange + + align:start position:0% +strange + + + align:start position:0% +strange +never world of quantum events + + align:start position:0% +never world of quantum events + + + align:start position:0% +never world of quantum events +what is matter marbles or waves + + align:start position:0% +what is matter marbles or waves + + + align:start position:0% +what is matter marbles or waves +and waves of what and what does an + + align:start position:0% +and waves of what and what does an + + + align:start position:0% +and waves of what and what does an +observer have to do with + + align:start position:0% +observer have to do with + + + align:start position:0% +observer have to do with +any of this the observer + + align:start position:0% +any of this the observer + + + align:start position:0% +any of this the observer +collapsed the wave function + + align:start position:0% +collapsed the wave function + + + align:start position:0% +collapsed the wave function +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +simply by observing + + align:start position:0% +simply by observing + + + align:start position:0% +simply by observing +you you can see why i show this uh we do + + align:start position:0% +you you can see why i show this uh we do + + + align:start position:0% +you you can see why i show this uh we do +movie night at home a lot + + align:start position:0% +movie night at home a lot + + + align:start position:0% +movie night at home a lot +it's friday night guys like seriously um + + align:start position:0% +it's friday night guys like seriously um + + + align:start position:0% +it's friday night guys like seriously um +you know + + align:start position:0% +you know + + + align:start position:0% +you know +that uh you know you might have like a + + align:start position:0% +that uh you know you might have like a + + + align:start position:0% +that uh you know you might have like a +little free time + + align:start position:0% +little free time + + + align:start position:0% +little free time +you get together with some friends + + align:start position:0% +you get together with some friends + + + align:start position:0% +you get together with some friends +there's no better way but look + + align:start position:0% +there's no better way but look + + + align:start position:0% +there's no better way but look +let me you know this is why i hope + + align:start position:0% +let me you know this is why i hope + + + align:start position:0% +let me you know this is why i hope +that's as mind-blowing to you as it is + + align:start position:0% +that's as mind-blowing to you as it is + + + align:start position:0% +that's as mind-blowing to you as it is +to me it was mind-blowing to them + + align:start position:0% +to me it was mind-blowing to them + + + align:start position:0% +to me it was mind-blowing to them +at the time um this led border famously + + align:start position:0% +at the time um this led border famously + + + align:start position:0% +at the time um this led border famously +say + + align:start position:0% +say + + + align:start position:0% +say +anyone who is not shocked by quantum + + align:start position:0% +anyone who is not shocked by quantum + + + align:start position:0% +anyone who is not shocked by quantum +theory has not understood it + + align:start position:0% +theory has not understood it + + + align:start position:0% +theory has not understood it +and and here's the thing there's uh + + align:start position:0% +and and here's the thing there's uh + + + align:start position:0% +and and here's the thing there's uh +you know there are some things in life + + align:start position:0% +you know there are some things in life + + + align:start position:0% +you know there are some things in life +where you can ask questions and and you + + align:start position:0% +where you can ask questions and and you + + + align:start position:0% +where you can ask questions and and you +can understand them you can answer them + + align:start position:0% +can understand them you can answer them + + + align:start position:0% +can understand them you can answer them +i can ask the question why do or + + align:start position:0% +i can ask the question why do or + + + align:start position:0% +i can ask the question why do or +somebody might say + + align:start position:0% +somebody might say + + + align:start position:0% +somebody might say +why do i wear a a t-shirt under a sport + + align:start position:0% +why do i wear a a t-shirt under a sport + + + align:start position:0% +why do i wear a a t-shirt under a sport +coat + + align:start position:0% +coat + + + align:start position:0% +coat +that's weird stylistically + + align:start position:0% +that's weird stylistically + + + align:start position:0% +that's weird stylistically +i mean stylistically that's and i say + + align:start position:0% +i mean stylistically that's and i say + + + align:start position:0% +i mean stylistically that's and i say +well okay here's the answer + + align:start position:0% +well okay here's the answer + + + align:start position:0% +well okay here's the answer +because i put you know comfort over + + align:start position:0% +because i put you know comfort over + + + align:start position:0% +because i put you know comfort over +stylistic norms whatever + + align:start position:0% +stylistic norms whatever + + + align:start position:0% +stylistic norms whatever +that's an answer i could ask a harder + + align:start position:0% +that's an answer i could ask a harder + + + align:start position:0% +that's an answer i could ask a harder +question + + align:start position:0% +question + + + align:start position:0% +question +i could ask a harder question why did + + align:start position:0% +i could ask a harder question why did + + + align:start position:0% +i could ask a harder question why did +justin and celina break up + + align:start position:0% +justin and celina break up + + + align:start position:0% +justin and celina break up +because jelena was totally hashtag + + align:start position:0% +because jelena was totally hashtag + + + align:start position:0% +because jelena was totally hashtag +couple goals + + align:start position:0% +couple goals + + + align:start position:0% +couple goals +just saying okay anyway now i'm just + + align:start position:0% + + + + align:start position:0% + +why oh but still that's a harder + + align:start position:0% +why oh but still that's a harder + + + align:start position:0% +why oh but still that's a harder +question + + align:start position:0% +question + + + align:start position:0% +question +why because they were so good but + + align:start position:0% +why because they were so good but + + + align:start position:0% +why because they were so good but +there's probably an answer to that too + + align:start position:0% +there's probably an answer to that too + + + align:start position:0% +there's probably an answer to that too +that's a harder question + + align:start position:0% +that's a harder question + + + align:start position:0% +that's a harder question +this was mind-blowing how can something + + align:start position:0% +this was mind-blowing how can something + + + align:start position:0% +this was mind-blowing how can something +be both how can something that they know + + align:start position:0% +be both how can something that they know + + + align:start position:0% +be both how can something that they know +is a part of how can everything + + align:start position:0% +is a part of how can everything + + + align:start position:0% +is a part of how can everything +be both this was really + + align:start position:0% +be both this was really + + + align:start position:0% +be both this was really +difficult to answer and in fact + + align:start position:0% +difficult to answer and in fact + + + align:start position:0% +difficult to answer and in fact +the real answer came with a mathematical + + align:start position:0% +the real answer came with a mathematical + + + align:start position:0% +the real answer came with a mathematical +solution + + align:start position:0% +solution + + + align:start position:0% +solution +which we'll learn next but not quite + + align:start position:0% +which we'll learn next but not quite + + + align:start position:0% +which we'll learn next but not quite +understanding + + align:start position:0% +understanding + + + align:start position:0% +understanding +we still don't really understand quantum + + align:start position:0% +we still don't really understand quantum + + + align:start position:0% +we still don't really understand quantum +mechanics even after 100 years + + align:start position:0% +mechanics even after 100 years + + + align:start position:0% +mechanics even after 100 years +we don't um and + + align:start position:0% +we don't um and + + + align:start position:0% +we don't um and +and so so this is just i think a + + align:start position:0% +and so so this is just i think a + + + align:start position:0% +and so so this is just i think a +beautiful part of + + align:start position:0% +beautiful part of + + + align:start position:0% +beautiful part of +our story of our detective story + + align:start position:0% +our story of our detective story + + + align:start position:0% +our story of our detective story +and just to show like people are still + + align:start position:0% +and just to show like people are still + + + align:start position:0% +and just to show like people are still +working on this right + + align:start position:0% +working on this right + + + align:start position:0% +working on this right +how much quantum can we see how much + + align:start position:0% +how much quantum can we see how much + + + align:start position:0% +how much quantum can we see how much +quantum can we see + + align:start position:0% +quantum can we see + + + align:start position:0% +quantum can we see +well look here's some here's somebody + + align:start position:0% +well look here's some here's somebody + + + align:start position:0% +well look here's some here's somebody +who + + align:start position:0% +who + + + align:start position:0% +who +about 15 years ago and it's published in + + align:start position:0% +about 15 years ago and it's published in + + + align:start position:0% +about 15 years ago and it's published in +this paper i'm a little more almost 20 + + align:start position:0% +this paper i'm a little more almost 20 + + + align:start position:0% +this paper i'm a little more almost 20 +now + + align:start position:0% +now + + + align:start position:0% +now +they actually took forget about + + align:start position:0% +they actually took forget about + + + align:start position:0% +they actually took forget about +electrons those are teeny tiny things + + align:start position:0% +electrons those are teeny tiny things + + + align:start position:0% +electrons those are teeny tiny things +this is a whole group of of 60 carbon + + align:start position:0% +this is a whole group of of 60 carbon + + + align:start position:0% +this is a whole group of of 60 carbon +atoms that's called a fullerene + + align:start position:0% +atoms that's called a fullerene + + + align:start position:0% +atoms that's called a fullerene +and they shot this through they did the + + align:start position:0% +and they shot this through they did the + + + align:start position:0% +and they shot this through they did the +double slit experiment with this + + align:start position:0% +double slit experiment with this + + + align:start position:0% +double slit experiment with this +and they showed that with the grating + + align:start position:0% +and they showed that with the grating + + + align:start position:0% +and they showed that with the grating +right without you get the single p + + align:start position:0% +right without you get the single p + + + align:start position:0% +right without you get the single p +just like we saw and with you get + + align:start position:0% +just like we saw and with you get + + + align:start position:0% +just like we saw and with you get +diffract you get interference + + align:start position:0% +diffract you get interference + + + align:start position:0% +diffract you get interference +you get interference so they were able + + align:start position:0% +you get interference so they were able + + + align:start position:0% +you get interference so they were able +to show all the way up to + + align:start position:0% +to show all the way up to + + + align:start position:0% +to show all the way up to +a large molecule 60 carbon atoms + + align:start position:0% +a large molecule 60 carbon atoms + + + align:start position:0% +a large molecule 60 carbon atoms +that these things are still they have + + align:start position:0% +that these things are still they have + + + align:start position:0% +that these things are still they have +wavelength they have these + + align:start position:0% +wavelength they have these + + + align:start position:0% +wavelength they have these +these incredibly strange properties that + + align:start position:0% +these incredibly strange properties that + + + align:start position:0% +these incredibly strange properties that +you just saw + + align:start position:0% +you just saw + + + align:start position:0% +you just saw +in the double slit experiment all + + align:start position:0% +in the double slit experiment all + + + align:start position:0% +in the double slit experiment all +everything has + + align:start position:0% +everything has + + + align:start position:0% +everything has +this duality this this duality between + + align:start position:0% +this duality this this duality between + + + align:start position:0% +this duality this this duality between +uh waves and particles + + align:start position:0% +uh waves and particles + + + align:start position:0% +uh waves and particles +now um okay + + align:start position:0% +now um okay + + + align:start position:0% +now um okay +we said we needed a new model right bohr + + align:start position:0% +we said we needed a new model right bohr + + + align:start position:0% +we said we needed a new model right bohr +can only do one electron + + align:start position:0% +can only do one electron + + + align:start position:0% +can only do one electron +and meanwhile there's all this stuff + + align:start position:0% +and meanwhile there's all this stuff + + + align:start position:0% +and meanwhile there's all this stuff +going on at the time + + align:start position:0% +going on at the time + + + align:start position:0% +going on at the time +you know showing that that there you + + align:start position:0% +you know showing that that there you + + + align:start position:0% +you know showing that that there you +need a new theory + + align:start position:0% +need a new theory + + + align:start position:0% +need a new theory +how do we explain waves and to kind of + + align:start position:0% +how do we explain waves and to kind of + + + align:start position:0% +how do we explain waves and to kind of +put a little bit more of of the nail in + + align:start position:0% +put a little bit more of of the nail in + + + align:start position:0% +put a little bit more of of the nail in +the coffin for for bore + + align:start position:0% +the coffin for for bore + + + align:start position:0% +the coffin for for bore +you had um you had heisenberg so i'll + + align:start position:0% +you had um you had heisenberg so i'll + + + align:start position:0% +you had um you had heisenberg so i'll +just + + align:start position:0% +just + + + align:start position:0% +just +write this on the board before i go to + + align:start position:0% +write this on the board before i go to + + + align:start position:0% +write this on the board before i go to +my why this matters + + align:start position:0% +my why this matters + + + align:start position:0% +my why this matters +um and what heisenberg said + + align:start position:0% +um and what heisenberg said + + + align:start position:0% +um and what heisenberg said +is that you cannot + + align:start position:0% +is that you cannot + + + align:start position:0% +is that you cannot +measure + + align:start position:0% + + + + align:start position:0% + +both + + align:start position:0% +both + + + align:start position:0% +both +position and + + align:start position:0% +position and + + + align:start position:0% +position and +momentum exactly + + align:start position:0% +momentum exactly + + + align:start position:0% +momentum exactly +you can't get them both okay and that + + align:start position:0% +you can't get them both okay and that + + + align:start position:0% +you can't get them both okay and that +that + + align:start position:0% +that + + + align:start position:0% +that +that's called the heisenberg uncertainty + + align:start position:0% +that's called the heisenberg uncertainty + + + align:start position:0% +that's called the heisenberg uncertainty +principle but that was it because look + + align:start position:0% +principle but that was it because look + + + align:start position:0% +principle but that was it because look +you look at that so he he's saying this + + align:start position:0% +you look at that so he he's saying this + + + align:start position:0% +you look at that so he he's saying this +and said but + + align:start position:0% +and said but + + + align:start position:0% +and said but +in board you've got them both you've got + + align:start position:0% +in board you've got them both you've got + + + align:start position:0% +in board you've got them both you've got +them both exactly + + align:start position:0% +them both exactly + + + align:start position:0% +them both exactly +remember we i put energy down there but + + align:start position:0% +remember we i put energy down there but + + + align:start position:0% +remember we i put energy down there but +we also put r + + align:start position:0% +we also put r + + + align:start position:0% +we also put r +on wednesday exactly because then type + + align:start position:0% +on wednesday exactly because then type + + + align:start position:0% +on wednesday exactly because then type +you can't get them both + + align:start position:0% +you can't get them both + + + align:start position:0% +you can't get them both +and if you can't get them both that's + + align:start position:0% +and if you can't get them both that's + + + align:start position:0% +and if you can't get them both that's +another problem with bohr because bohr + + align:start position:0% +another problem with bohr because bohr + + + align:start position:0% +another problem with bohr because bohr +says you can get them exactly right + + align:start position:0% +says you can get them exactly right + + + align:start position:0% +says you can get them exactly right +so we had these pointers double sid + + align:start position:0% +so we had these pointers double sid + + + align:start position:0% +so we had these pointers double sid +experiment heisenberg's theories + + align:start position:0% +experiment heisenberg's theories + + + align:start position:0% +experiment heisenberg's theories +right saying we need something more we + + align:start position:0% +right saying we need something more we + + + align:start position:0% +right saying we need something more we +need something more + + align:start position:0% +need something more + + + align:start position:0% +need something more +and i'll i'll get to that um i want to + + align:start position:0% +and i'll i'll get to that um i want to + + + align:start position:0% +and i'll i'll get to that um i want to +do my why this matters and then i'll get + + align:start position:0% +do my why this matters and then i'll get + + + align:start position:0% +do my why this matters and then i'll get +to + + align:start position:0% +to + + + align:start position:0% +to +the more that came which will then + + align:start position:0% +the more that came which will then + + + align:start position:0% +the more that came which will then +expand on on monday + + align:start position:0% +expand on on monday + + + align:start position:0% +expand on on monday +um before i do that let's do wise + + align:start position:0% +um before i do that let's do wise + + + align:start position:0% +um before i do that let's do wise +matters so why + + align:start position:0% +matters so why + + + align:start position:0% +matters so why +why are why is the fact that an electron + + align:start position:0% +why are why is the fact that an electron + + + align:start position:0% +why are why is the fact that an electron +is a wave why is that so + + align:start position:0% +is a wave why is that so + + + align:start position:0% +is a wave why is that so +important first of all because it sets + + align:start position:0% +important first of all because it sets + + + align:start position:0% +important first of all because it sets +up + + align:start position:0% +up + + + align:start position:0% +up +you know this this detective story of + + align:start position:0% +you know this this detective story of + + + align:start position:0% +you know this this detective story of +the electron + + align:start position:0% +the electron + + + align:start position:0% +the electron +set up this new theory that's coming + + align:start position:0% +set up this new theory that's coming + + + align:start position:0% +set up this new theory that's coming +quantum mechanics right + + align:start position:0% +quantum mechanics right + + + align:start position:0% +quantum mechanics right +um but also it immediately just like + + align:start position:0% +um but also it immediately just like + + + align:start position:0% +um but also it immediately just like +just like we started painting with them + + align:start position:0% +just like we started painting with them + + + align:start position:0% +just like we started painting with them +right remember that was one of my widest + + align:start position:0% +right remember that was one of my widest + + + align:start position:0% +right remember that was one of my widest +matters we also realized that we could + + align:start position:0% +matters we also realized that we could + + + align:start position:0% +matters we also realized that we could +see + + align:start position:0% +see + + + align:start position:0% +see +with them we could see with electrons + + align:start position:0% +with them we could see with electrons + + + align:start position:0% +with them we could see with electrons +because you know if electrons are waves + + align:start position:0% +because you know if electrons are waves + + + align:start position:0% +because you know if electrons are waves +then i can shine them just like i shine + + align:start position:0% +then i can shine them just like i shine + + + align:start position:0% +then i can shine them just like i shine +light and see what it shows me + + align:start position:0% +light and see what it shows me + + + align:start position:0% +light and see what it shows me +right it can illuminate matter + + align:start position:0% +right it can illuminate matter + + + align:start position:0% +right it can illuminate matter +so you know if you look at the frequency + + align:start position:0% +so you know if you look at the frequency + + + align:start position:0% +so you know if you look at the frequency +here + + align:start position:0% +here + + + align:start position:0% +here +of light right this is this is a + + align:start position:0% +of light right this is this is a + + + align:start position:0% +of light right this is this is a +electromagnetic spectrum + + align:start position:0% +electromagnetic spectrum + + + align:start position:0% +electromagnetic spectrum +radio right microwave infrared visible + + align:start position:0% +radio right microwave infrared visible + + + align:start position:0% +radio right microwave infrared visible +uv now here's the thing + + align:start position:0% +uv now here's the thing + + + align:start position:0% +uv now here's the thing +if you want to see something + + align:start position:0% +if you want to see something + + + align:start position:0% +if you want to see something +some feature size you're limited + + align:start position:0% +some feature size you're limited + + + align:start position:0% +some feature size you're limited +by the wavelength of the light it can't + + align:start position:0% +by the wavelength of the light it can't + + + align:start position:0% +by the wavelength of the light it can't +be + + align:start position:0% +be + + + align:start position:0% +be +bigger than the features you're looking + + align:start position:0% +bigger than the features you're looking + + + align:start position:0% +bigger than the features you're looking +at roughly ish + + align:start position:0% +at roughly ish + + + align:start position:0% +at roughly ish +okay that's what you're so if you're + + align:start position:0% +okay that's what you're so if you're + + + align:start position:0% +okay that's what you're so if you're +trying to see something tiny but the + + align:start position:0% +trying to see something tiny but the + + + align:start position:0% +trying to see something tiny but the +wavelength of light is really big + + align:start position:0% +wavelength of light is really big + + + align:start position:0% +wavelength of light is really big +you won't see it so we need if we want + + align:start position:0% +you won't see it so we need if we want + + + align:start position:0% +you won't see it so we need if we want +let's say we want to see atoms + + align:start position:0% +let's say we want to see atoms + + + align:start position:0% +let's say we want to see atoms +let's say we want to see atoms or or or + + align:start position:0% +let's say we want to see atoms or or or + + + align:start position:0% +let's say we want to see atoms or or or +even more nuclei + + align:start position:0% +even more nuclei + + + align:start position:0% +even more nuclei +look at how tight those are 10 to the + + align:start position:0% +look at how tight those are 10 to the + + + align:start position:0% +look at how tight those are 10 to the +minus 10 centimeters 12 meters + + align:start position:0% +minus 10 centimeters 12 meters + + + align:start position:0% +minus 10 centimeters 12 meters +those are x-rays or gamma rays but the + + align:start position:0% +those are x-rays or gamma rays but the + + + align:start position:0% +those are x-rays or gamma rays but the +problem is if we shine + + align:start position:0% +problem is if we shine + + + align:start position:0% +problem is if we shine +x-rays on things and we will do that + + align:start position:0% +x-rays on things and we will do that + + + align:start position:0% +x-rays on things and we will do that +when we look at crystals + + align:start position:0% +when we look at crystals + + + align:start position:0% +when we look at crystals +but if we shine x-rays it's very hard to + + align:start position:0% +but if we shine x-rays it's very hard to + + + align:start position:0% +but if we shine x-rays it's very hard to +then collect them and make a + + align:start position:0% +then collect them and make a + + + align:start position:0% +then collect them and make a +photographic image + + align:start position:0% +photographic image + + + align:start position:0% +photographic image +okay right i mean at least one that gets + + align:start position:0% +okay right i mean at least one that gets + + + align:start position:0% +okay right i mean at least one that gets +you that resolution + + align:start position:0% +you that resolution + + + align:start position:0% +you that resolution +and gamma rays are even harder to catch + + align:start position:0% +and gamma rays are even harder to catch + + + align:start position:0% +and gamma rays are even harder to catch +right + + align:start position:0% +right + + + align:start position:0% +right +oh but see here's the thing electrons + + align:start position:0% +oh but see here's the thing electrons + + + align:start position:0% +oh but see here's the thing electrons +electrons give you exactly what you need + + align:start position:0% +electrons give you exactly what you need + + + align:start position:0% +electrons give you exactly what you need +because you know if we do this math + + align:start position:0% +because you know if we do this math + + + align:start position:0% +because you know if we do this math +for an electron let's bring this one + + align:start position:0% +for an electron let's bring this one + + + align:start position:0% +for an electron let's bring this one +back down + + align:start position:0% +back down + + + align:start position:0% +back down +if we do this math for an electron well + + align:start position:0% +if we do this math for an electron well + + + align:start position:0% +if we do this math for an electron well +i'm going to use + + align:start position:0% +i'm going to use + + + align:start position:0% +i'm going to use +ah i thought i had the middle one so if + + align:start position:0% +ah i thought i had the middle one so if + + + align:start position:0% +ah i thought i had the middle one so if +i have an electron let's suppose i have + + align:start position:0% +i have an electron let's suppose i have + + + align:start position:0% +i have an electron let's suppose i have +an electron + + align:start position:0% +an electron + + + align:start position:0% +an electron +that is + + align:start position:0% + + + + align:start position:0% + +electron i'm going to say i accelerate + + align:start position:0% +electron i'm going to say i accelerate + + + align:start position:0% +electron i'm going to say i accelerate +it + + align:start position:0% + + + + align:start position:0% + +over 100 volts + + align:start position:0% +over 100 volts + + + align:start position:0% +over 100 volts +i'm going to take an electron i'm going + + align:start position:0% +i'm going to take an electron i'm going + + + align:start position:0% +i'm going to take an electron i'm going +to put it over 100 volts i'm going to + + align:start position:0% +to put it over 100 volts i'm going to + + + align:start position:0% +to put it over 100 volts i'm going to +give it some kinetic energy + + align:start position:0% +give it some kinetic energy + + + align:start position:0% +give it some kinetic energy +right so its kinetic energy + + align:start position:0% +right so its kinetic energy + + + align:start position:0% +right so its kinetic energy +is then going to equal 100 ev right + + align:start position:0% +is then going to equal 100 ev right + + + align:start position:0% +is then going to equal 100 ev right +okay so now i've got an electron moving + + align:start position:0% +okay so now i've got an electron moving + + + align:start position:0% +okay so now i've got an electron moving +with a kinetic energy that's 100 ev now + + align:start position:0% +with a kinetic energy that's 100 ev now + + + align:start position:0% +with a kinetic energy that's 100 ev now +you can convert this to joules and you + + align:start position:0% +you can convert this to joules and you + + + align:start position:0% +you can convert this to joules and you +can + + align:start position:0% +can + + + align:start position:0% +can +set this equal to one-half mv squared + + align:start position:0% +set this equal to one-half mv squared + + + align:start position:0% +set this equal to one-half mv squared +right + + align:start position:0% +right + + + align:start position:0% +right +mass of the electron times its velocity + + align:start position:0% +mass of the electron times its velocity + + + align:start position:0% +mass of the electron times its velocity +squared and + + align:start position:0% +squared and + + + align:start position:0% +squared and +then once you have the velocity so you + + align:start position:0% +then once you have the velocity so you + + + align:start position:0% +then once you have the velocity so you +get the v + + align:start position:0% + + + + align:start position:0% + +and then once you have that you get the + + align:start position:0% +and then once you have that you get the + + + align:start position:0% +and then once you have that you get the +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +the p right and then once you have that + + align:start position:0% +the p right and then once you have that + + + align:start position:0% +the p right and then once you have that +you get the wavelength right so i can go + + align:start position:0% +you get the wavelength right so i can go + + + align:start position:0% +you get the wavelength right so i can go +now from like + + align:start position:0% +now from like + + + align:start position:0% +now from like +something that's easy to do 100 volts is + + align:start position:0% +something that's easy to do 100 volts is + + + align:start position:0% +something that's easy to do 100 volts is +a lot but + + align:start position:0% +a lot but + + + align:start position:0% +a lot but +in a lab safe not in your dorm you could + + align:start position:0% +in a lab safe not in your dorm you could + + + align:start position:0% +in a lab safe not in your dorm you could +apply 100 volts + + align:start position:0% +apply 100 volts + + + align:start position:0% +apply 100 volts +to an electron get it going at this + + align:start position:0% +to an electron get it going at this + + + align:start position:0% +to an electron get it going at this +speed + + align:start position:0% +speed + + + align:start position:0% +speed +and once you know the speed you know the + + align:start position:0% +and once you know the speed you know the + + + align:start position:0% +and once you know the speed you know the +momentum and if you know mv + + align:start position:0% +momentum and if you know mv + + + align:start position:0% +momentum and if you know mv +then you know it's wavelength and that + + align:start position:0% +then you know it's wavelength and that + + + align:start position:0% +then you know it's wavelength and that +in that case + + align:start position:0% +in that case + + + align:start position:0% +in that case +from this relationship you would get + + align:start position:0% +from this relationship you would get + + + align:start position:0% +from this relationship you would get +that it's about 0.12 + + align:start position:0% +that it's about 0.12 + + + align:start position:0% +that it's about 0.12 +nanometers but look at this the + + align:start position:0% +nanometers but look at this the + + + align:start position:0% +nanometers but look at this the +wavelength of a + + align:start position:0% +wavelength of a + + + align:start position:0% +wavelength of a +simply accelerated electron is right + + align:start position:0% +simply accelerated electron is right + + + align:start position:0% +simply accelerated electron is right +where i need it + + align:start position:0% +where i need it + + + align:start position:0% +where i need it +it's right where i need it it's an + + align:start position:0% +it's right where i need it it's an + + + align:start position:0% +it's right where i need it it's an +angstrom + + align:start position:0% +angstrom + + + align:start position:0% +angstrom +right so now i think if i take advantage + + align:start position:0% +right so now i think if i take advantage + + + align:start position:0% +right so now i think if i take advantage +of the wavelengths of the wave nature of + + align:start position:0% +of the wavelengths of the wave nature of + + + align:start position:0% +of the wavelengths of the wave nature of +electrons and i shine them + + align:start position:0% +electrons and i shine them + + + align:start position:0% +electrons and i shine them +on materials then i can see materials + + align:start position:0% +on materials then i can see materials + + + align:start position:0% +on materials then i can see materials +that way and i can see them at that + + align:start position:0% +that way and i can see them at that + + + align:start position:0% +that way and i can see them at that +scale and we do that all the time + + align:start position:0% +scale and we do that all the time + + + align:start position:0% +scale and we do that all the time +all the time in in many many different + + align:start position:0% +all the time in in many many different + + + align:start position:0% +all the time in in many many different +areas of technology + + align:start position:0% +areas of technology + + + align:start position:0% +areas of technology +and of research today we use electrons + + align:start position:0% +and of research today we use electrons + + + align:start position:0% +and of research today we use electrons +to image in fact the best images you can + + align:start position:0% +to image in fact the best images you can + + + align:start position:0% +to image in fact the best images you can +get + + align:start position:0% +get + + + align:start position:0% +get +are made with electrons right here's an + + align:start position:0% +are made with electrons right here's an + + + align:start position:0% +are made with electrons right here's an +example + + align:start position:0% +example + + + align:start position:0% +example +of using scanning what's called a + + align:start position:0% +of using scanning what's called a + + + align:start position:0% +of using scanning what's called a +scanning electron microscope + + align:start position:0% +scanning electron microscope + + + align:start position:0% +scanning electron microscope +right so you see a butterfly but you + + align:start position:0% +right so you see a butterfly but you + + + align:start position:0% +right so you see a butterfly but you +want to really see a butterfly + + align:start position:0% +want to really see a butterfly + + + align:start position:0% +want to really see a butterfly +or we can go even further and instead of + + align:start position:0% +or we can go even further and instead of + + + align:start position:0% +or we can go even further and instead of +just drawing pictures + + align:start position:0% +just drawing pictures + + + align:start position:0% +just drawing pictures +of this these beautiful materials made + + align:start position:0% +of this these beautiful materials made + + + align:start position:0% +of this these beautiful materials made +of carbon those are called nanotubes + + align:start position:0% +of carbon those are called nanotubes + + + align:start position:0% +of carbon those are called nanotubes +these are called this is called graphene + + align:start position:0% +these are called this is called graphene + + + align:start position:0% +these are called this is called graphene +because in tight + + align:start position:0% +because in tight + + + align:start position:0% +because in tight +it's a single sheet of carbon atoms one + + align:start position:0% +it's a single sheet of carbon atoms one + + + align:start position:0% +it's a single sheet of carbon atoms one +atom thick material notice with these + + align:start position:0% +atom thick material notice with these + + + align:start position:0% +atom thick material notice with these +materials + + align:start position:0% +materials + + + align:start position:0% +materials +every single atom is a surface atom + + align:start position:0% +every single atom is a surface atom + + + align:start position:0% +every single atom is a surface atom +that's pretty cool + + align:start position:0% +that's pretty cool + + + align:start position:0% +that's pretty cool +they also have lots of other cool + + align:start position:0% +they also have lots of other cool + + + align:start position:0% +they also have lots of other cool +properties and i'll give you examples + + align:start position:0% +properties and i'll give you examples + + + align:start position:0% +properties and i'll give you examples +throughout you know in other other + + align:start position:0% +throughout you know in other other + + + align:start position:0% +throughout you know in other other +lectures of how these kinds of materials + + align:start position:0% +lectures of how these kinds of materials + + + align:start position:0% +lectures of how these kinds of materials +can be used + + align:start position:0% +can be used + + + align:start position:0% +can be used +but for now i'm talking about seeing + + align:start position:0% +but for now i'm talking about seeing + + + align:start position:0% +but for now i'm talking about seeing +them and this is what happens + + align:start position:0% +them and this is what happens + + + align:start position:0% +them and this is what happens +when you actually look at them with an + + align:start position:0% +when you actually look at them with an + + + align:start position:0% +when you actually look at them with an +electron that's a nanotube and here + + align:start position:0% +electron that's a nanotube and here + + + align:start position:0% +electron that's a nanotube and here +is a picture of graphene the only reason + + align:start position:0% +is a picture of graphene the only reason + + + align:start position:0% +is a picture of graphene the only reason +we can see graphene + + align:start position:0% +we can see graphene + + + align:start position:0% +we can see graphene +is because we have electrons and we take + + align:start position:0% +is because we have electrons and we take + + + align:start position:0% +is because we have electrons and we take +advantage of the wave nature + + align:start position:0% +advantage of the wave nature + + + align:start position:0% +advantage of the wave nature +of those electrons we say well okay but + + align:start position:0% +of those electrons we say well okay but + + + align:start position:0% +of those electrons we say well okay but +why does that matter + + align:start position:0% +why does that matter + + + align:start position:0% +why does that matter +well that matters tremendously because + + align:start position:0% +well that matters tremendously because + + + align:start position:0% +well that matters tremendously because +one of the first experiments + + align:start position:0% +one of the first experiments + + + align:start position:0% +one of the first experiments +that really did what feynman what + + align:start position:0% +that really did what feynman what + + + align:start position:0% +that really did what feynman what +richard feynman wanted + + align:start position:0% +richard feynman wanted + + + align:start position:0% +richard feynman wanted +richard feynman predicted the the field + + align:start position:0% +richard feynman predicted the the field + + + align:start position:0% +richard feynman predicted the the field +of nanotechnology + + align:start position:0% +of nanotechnology + + + align:start position:0% +of nanotechnology +50 years ago he gave a famous speech at + + align:start position:0% +50 years ago he gave a famous speech at + + + align:start position:0% +50 years ago he gave a famous speech at +caltech it's called there's plenty of + + align:start position:0% +caltech it's called there's plenty of + + + align:start position:0% +caltech it's called there's plenty of +room at the bottom + + align:start position:0% +room at the bottom + + + align:start position:0% +room at the bottom +he's also an amazing teacher and he + + align:start position:0% +he's also an amazing teacher and he + + + align:start position:0% +he's also an amazing teacher and he +taught actually the double slit + + align:start position:0% +taught actually the double slit + + + align:start position:0% +taught actually the double slit +experiment i highly recommend you + + align:start position:0% +experiment i highly recommend you + + + align:start position:0% +experiment i highly recommend you +googling that lecture and he said that + + align:start position:0% +googling that lecture and he said that + + + align:start position:0% +googling that lecture and he said that +you know someday you can put the atom + + align:start position:0% +you know someday you can put the atom + + + align:start position:0% +you know someday you can put the atom +where you want + + align:start position:0% +where you want + + + align:start position:0% +where you want +right and the first time that was done + + align:start position:0% +right and the first time that was done + + + align:start position:0% +right and the first time that was done +was in 1989 by ibm + + align:start position:0% +was in 1989 by ibm + + + align:start position:0% +was in 1989 by ibm +they had 35 xenon atoms they moved them + + align:start position:0% +they had 35 xenon atoms they moved them + + + align:start position:0% +they had 35 xenon atoms they moved them +around the point is you couldn't realize + + align:start position:0% +around the point is you couldn't realize + + + align:start position:0% +around the point is you couldn't realize +nanotechnology you couldn't + + align:start position:0% +nanotechnology you couldn't + + + align:start position:0% +nanotechnology you couldn't +realize the ability to actually move + + align:start position:0% +realize the ability to actually move + + + align:start position:0% +realize the ability to actually move +atoms if you can't see them + + align:start position:0% +atoms if you can't see them + + + align:start position:0% +atoms if you can't see them +right and so this you know the ability + + align:start position:0% +right and so this you know the ability + + + align:start position:0% +right and so this you know the ability +to see + + align:start position:0% +to see + + + align:start position:0% +to see +what you were doing changed everything + + align:start position:0% +what you were doing changed everything + + + align:start position:0% +what you were doing changed everything +it changed everything and you know + + align:start position:0% +it changed everything and you know + + + align:start position:0% +it changed everything and you know +nature had been doing this and i love + + align:start position:0% +nature had been doing this and i love + + + align:start position:0% +nature had been doing this and i love +these examples so you know nature has + + align:start position:0% +these examples so you know nature has + + + align:start position:0% +these examples so you know nature has +been doing nanotech for a long time + + align:start position:0% +been doing nanotech for a long time + + + align:start position:0% +been doing nanotech for a long time +right uh so you have uh the inner ear of + + align:start position:0% +right uh so you have uh the inner ear of + + + align:start position:0% +right uh so you have uh the inner ear of +the frog it's a cantilever that uh + + align:start position:0% +the frog it's a cantilever that uh + + + align:start position:0% +the frog it's a cantilever that uh +sensitive to a few nanometers of + + align:start position:0% +sensitive to a few nanometers of + + + align:start position:0% +sensitive to a few nanometers of +movement the frog can actually hear that + + align:start position:0% +movement the frog can actually hear that + + + align:start position:0% +movement the frog can actually hear that +you've got features in the ant's eye i + + align:start position:0% +you've got features in the ant's eye i + + + align:start position:0% +you've got features in the ant's eye i +love the the silk moth + + align:start position:0% +love the the silk moth + + + align:start position:0% +love the the silk moth +the male silk moth has a single + + align:start position:0% +the male silk moth has a single + + + align:start position:0% +the male silk moth has a single +molecule detection system on board + + align:start position:0% +molecule detection system on board + + + align:start position:0% +molecule detection system on board +that can sense a single molecule + + align:start position:0% +that can sense a single molecule + + + align:start position:0% +that can sense a single molecule +pheromone it can detect a female silk + + align:start position:0% +pheromone it can detect a female silk + + + align:start position:0% +pheromone it can detect a female silk +moth two miles away + + align:start position:0% +moth two miles away + + + align:start position:0% +moth two miles away +two miles away we have nothing like that + + align:start position:0% +two miles away we have nothing like that + + + align:start position:0% +two miles away we have nothing like that +we have no technologies like that i + + align:start position:0% +we have no technologies like that i + + + align:start position:0% +we have no technologies like that i +can't even tell if someone's in the next + + align:start position:0% +can't even tell if someone's in the next + + + align:start position:0% +can't even tell if someone's in the next +room + + align:start position:0% +room + + + align:start position:0% +room +i have to look at my phone or something + + align:start position:0% +i have to look at my phone or something + + + align:start position:0% +i have to look at my phone or something +this is because of nanotechnology + + align:start position:0% +this is because of nanotechnology + + + align:start position:0% +this is because of nanotechnology +that kind of detection system right but + + align:start position:0% +that kind of detection system right but + + + align:start position:0% +that kind of detection system right but +it was the ability to see + + align:start position:0% +it was the ability to see + + + align:start position:0% +it was the ability to see +atoms and molecules with electrons that + + align:start position:0% +atoms and molecules with electrons that + + + align:start position:0% +atoms and molecules with electrons that +that kind of blew open this entire field + + align:start position:0% +that kind of blew open this entire field + + + align:start position:0% +that kind of blew open this entire field +right and it's made it so that we can + + align:start position:0% +right and it's made it so that we can + + + align:start position:0% +right and it's made it so that we can +now try at least to rival nature + + align:start position:0% +now try at least to rival nature + + + align:start position:0% +now try at least to rival nature +here's one example you're not just + + align:start position:0% +here's one example you're not just + + + align:start position:0% +here's one example you're not just +seeing graphene but check this out + + align:start position:0% +seeing graphene but check this out + + + align:start position:0% +seeing graphene but check this out +you're seeing a single atom of graphene + + align:start position:0% +you're seeing a single atom of graphene + + + align:start position:0% +you're seeing a single atom of graphene +and you're seeing what happens + + align:start position:0% +and you're seeing what happens + + + align:start position:0% +and you're seeing what happens +under a certain kind of ra irradiation + + align:start position:0% +under a certain kind of ra irradiation + + + align:start position:0% +under a certain kind of ra irradiation +and you're seeing this hole + + align:start position:0% +and you're seeing this hole + + + align:start position:0% +and you're seeing this hole +and you're seeing the whole grow and + + align:start position:0% +and you're seeing the whole grow and + + + align:start position:0% +and you're seeing the whole grow and +that's really important because + + align:start position:0% +that's really important because + + + align:start position:0% +that's really important because +something i care a lot about our + + align:start position:0% +something i care a lot about our + + + align:start position:0% +something i care a lot about our +membranes + + align:start position:0% +membranes + + + align:start position:0% +membranes +right and another why this matters i'll + + align:start position:0% +right and another why this matters i'll + + + align:start position:0% +right and another why this matters i'll +tell you about membranes but here + + align:start position:0% +tell you about membranes but here + + + align:start position:0% +tell you about membranes but here +you know i'm actually making the + + align:start position:0% +you know i'm actually making the + + + align:start position:0% +you know i'm actually making the +thinnest possible membrane that + + align:start position:0% +thinnest possible membrane that + + + align:start position:0% +thinnest possible membrane that +that you could make because it's only + + align:start position:0% +that you could make because it's only + + + align:start position:0% +that you could make because it's only +one atom thick and i'm controlling + + align:start position:0% +one atom thick and i'm controlling + + + align:start position:0% +one atom thick and i'm controlling +how i make that but i would never know + + align:start position:0% +how i make that but i would never know + + + align:start position:0% +how i make that but i would never know +what my controls do if i couldn't see it + + align:start position:0% +what my controls do if i couldn't see it + + + align:start position:0% +what my controls do if i couldn't see it +in real time right so this is this is my + + align:start position:0% +in real time right so this is this is my + + + align:start position:0% +in real time right so this is this is my +my why this matters it's seeing things + + align:start position:0% +my why this matters it's seeing things + + + align:start position:0% +my why this matters it's seeing things +at this scale + + align:start position:0% +at this scale + + + align:start position:0% +at this scale +okay so back to so there's heisenberg + + align:start position:0% +okay so back to so there's heisenberg + + + align:start position:0% +okay so back to so there's heisenberg +right so at every moment + + align:start position:0% +right so at every moment + + + align:start position:0% +right so at every moment +the electron is only inaccurate position + + align:start position:0% +the electron is only inaccurate position + + + align:start position:0% +the electron is only inaccurate position +and inaccurate velocity this was + + align:start position:0% +and inaccurate velocity this was + + + align:start position:0% +and inaccurate velocity this was +again saying bohr you got to think + + align:start position:0% +again saying bohr you got to think + + + align:start position:0% +again saying bohr you got to think +harder + + align:start position:0% +harder + + + align:start position:0% +harder +um and we had all of this these + + align:start position:0% +um and we had all of this these + + + align:start position:0% +um and we had all of this these +experiments showing the + + align:start position:0% +experiments showing the + + + align:start position:0% +experiments showing the +the the particle wave duality of nature + + align:start position:0% +the the particle wave duality of nature + + + align:start position:0% +the the particle wave duality of nature +and of + + align:start position:0% +and of + + + align:start position:0% +and of +of atoms um and so the question then + + align:start position:0% +of atoms um and so the question then + + + align:start position:0% +of atoms um and so the question then +became + + align:start position:0% +became + + + align:start position:0% +became +all these pointers from all these + + align:start position:0% +all these pointers from all these + + + align:start position:0% +all these pointers from all these +different places the question became + + align:start position:0% +different places the question became + + + align:start position:0% +different places the question became +how do we describe these this wave + + align:start position:0% +how do we describe these this wave + + + align:start position:0% +how do we describe these this wave +nature + + align:start position:0% +nature + + + align:start position:0% +nature +of matter how do we describe an electron + + align:start position:0% +of matter how do we describe an electron + + + align:start position:0% +of matter how do we describe an electron +as a wave and i like this + + align:start position:0% +as a wave and i like this + + + align:start position:0% +as a wave and i like this +because not only do i think if + + align:start position:0% +because not only do i think if + + + align:start position:0% +because not only do i think if +schrodinger had a swimming pool + + align:start position:0% +schrodinger had a swimming pool + + + align:start position:0% +schrodinger had a swimming pool +this is what he would do with it but + + align:start position:0% +this is what he would do with it but + + + align:start position:0% +this is what he would do with it but +also i thought maybe this would be cool + + align:start position:0% +also i thought maybe this would be cool + + + align:start position:0% +also i thought maybe this would be cool +for like an mit + + align:start position:0% +for like an mit + + + align:start position:0% +for like an mit +kind of swim test thing um in the future + + align:start position:0% +kind of swim test thing um in the future + + + align:start position:0% +kind of swim test thing um in the future +because you can see what happens + + align:start position:0% +because you can see what happens + + + align:start position:0% +because you can see what happens +um this just i i want to do this + + align:start position:0% +um this just i i want to do this + + + align:start position:0% +um this just i i want to do this +experiment + + align:start position:0% +experiment + + + align:start position:0% +experiment +um but this looks really fun they're + + align:start position:0% +um but this looks really fun they're + + + align:start position:0% +um but this looks really fun they're +making waves they're + + align:start position:0% +making waves they're + + + align:start position:0% +making waves they're +they're literally making waves right um + + align:start position:0% +they're literally making waves right um + + + align:start position:0% +they're literally making waves right um +but and so the question now look at that + + align:start position:0% +but and so the question now look at that + + + align:start position:0% +but and so the question now look at that +see but the question is how do you + + align:start position:0% +see but the question is how do you + + + align:start position:0% +see but the question is how do you +describe it well there are wave + + align:start position:0% +describe it well there are wave + + + align:start position:0% +describe it well there are wave +equations + + align:start position:0% +equations + + + align:start position:0% +equations +there are wave equations that we know + + align:start position:0% +there are wave equations that we know + + + align:start position:0% +there are wave equations that we know +about + + align:start position:0% +about + + + align:start position:0% +about +that relate the position of a wave to + + align:start position:0% +that relate the position of a wave to + + + align:start position:0% +that relate the position of a wave to +its time change and velocity + + align:start position:0% +its time change and velocity + + + align:start position:0% +its time change and velocity +right and and the thing is this is it + + align:start position:0% +right and and the thing is this is it + + + align:start position:0% +right and and the thing is this is it +this is how we need to describe an + + align:start position:0% +this is how we need to describe an + + + align:start position:0% +this is how we need to describe an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +now think about it for a second an + + align:start position:0% +now think about it for a second an + + + align:start position:0% +now think about it for a second an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +by the way it just occurred to me that + + align:start position:0% +by the way it just occurred to me that + + + align:start position:0% +by the way it just occurred to me that +you should take this on that same date + + align:start position:0% +you should take this on that same date + + + align:start position:0% +you should take this on that same date +because + + align:start position:0% +because + + + align:start position:0% +because +if they don't have real candles and they + + align:start position:0% +if they don't have real candles and they + + + align:start position:0% +if they don't have real candles and they +only have these + + align:start position:0% +only have these + + + align:start position:0% +only have these +you should have this handy because you + + align:start position:0% +you should have this handy because you + + + align:start position:0% +you should have this handy because you +might need to pull it out and see what + + align:start position:0% +might need to pull it out and see what + + + align:start position:0% +might need to pull it out and see what +kind of led + + align:start position:0% +kind of led + + + align:start position:0% +kind of led +they gave you what does it look like + + align:start position:0% +they gave you what does it look like + + + align:start position:0% +they gave you what does it look like +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +okay that was a side point + + align:start position:0% +okay that was a side point + + + align:start position:0% +okay that was a side point +bohr says electrons can only be in + + align:start position:0% +bohr says electrons can only be in + + + align:start position:0% +bohr says electrons can only be in +certain places + + align:start position:0% +certain places + + + align:start position:0% +certain places +well that's mind-blowing because but by + + align:start position:0% +well that's mind-blowing because but by + + + align:start position:0% +well that's mind-blowing because but by +the way think about that + + align:start position:0% +the way think about that + + + align:start position:0% +the way think about that +an electron can only be here here oh by + + align:start position:0% +an electron can only be here here oh by + + + align:start position:0% +an electron can only be here here oh by +the way it can transition between them + + align:start position:0% +the way it can transition between them + + + align:start position:0% +the way it can transition between them +but it can never be + + align:start position:0% +but it can never be + + + align:start position:0% +but it can never be +between them did anyone catch that + + align:start position:0% +between them did anyone catch that + + + align:start position:0% +between them did anyone catch that +what's up with that it can't be between + + align:start position:0% +what's up with that it can't be between + + + align:start position:0% +what's up with that it can't be between +them i am + + align:start position:0% +them i am + + + align:start position:0% +them i am +telling you that but it can transition + + align:start position:0% +telling you that but it can transition + + + align:start position:0% +telling you that but it can transition +where did it go + + align:start position:0% +where did it go + + + align:start position:0% +where did it go +oh okay that's a weekend kind of + + align:start position:0% +oh okay that's a weekend kind of + + + align:start position:0% +oh okay that's a weekend kind of +thinking exercise + + align:start position:0% +thinking exercise + + + align:start position:0% +thinking exercise +and now we're saying they're not even + + align:start position:0% +and now we're saying they're not even + + + align:start position:0% +and now we're saying they're not even +they're not even like + + align:start position:0% +they're not even like + + + align:start position:0% +they're not even like +in one place they're waves + + align:start position:0% +in one place they're waves + + + align:start position:0% +in one place they're waves +they're like the water + + align:start position:0% + + + + align:start position:0% + +that's cra that that really was at the + + align:start position:0% +that's cra that that really was at the + + + align:start position:0% +that's cra that that really was at the +time they thought how is this possible + + align:start position:0% +time they thought how is this possible + + + align:start position:0% +time they thought how is this possible +right but schrodinger came along and he + + align:start position:0% +right but schrodinger came along and he + + + align:start position:0% +right but schrodinger came along and he +said i'm gonna write down the equation + + align:start position:0% +said i'm gonna write down the equation + + + align:start position:0% +said i'm gonna write down the equation +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +and and that's that was the the + + align:start position:0% +and and that's that was the the + + + align:start position:0% +and and that's that was the the +the big contribution the the really + + align:start position:0% +the big contribution the the really + + + align:start position:0% +the big contribution the the really +critical contribution that schroedinger + + align:start position:0% +critical contribution that schroedinger + + + align:start position:0% +critical contribution that schroedinger +did + + align:start position:0% +did + + + align:start position:0% +did +is he said i'm gonna i'm gonna write + + align:start position:0% +is he said i'm gonna i'm gonna write + + + align:start position:0% +is he said i'm gonna i'm gonna write +down + + align:start position:0% +down + + + align:start position:0% +down +kind of like a newton's equation like an + + align:start position:0% +kind of like a newton's equation like an + + + align:start position:0% +kind of like a newton's equation like an +f equals ma but for + + align:start position:0% +f equals ma but for + + + align:start position:0% +f equals ma but for +for quantum mechanics and for waves like + + align:start position:0% +for quantum mechanics and for waves like + + + align:start position:0% +for quantum mechanics and for waves like +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +and i'm going to describe them so he + + align:start position:0% +and i'm going to describe them so he + + + align:start position:0% +and i'm going to describe them so he +developed the equation + + align:start position:0% +developed the equation + + + align:start position:0% +developed the equation +that we solved that on monday we'll + + align:start position:0% +that we solved that on monday we'll + + + align:start position:0% +that we solved that on monday we'll +solve to describe the wave nature + + align:start position:0% +solve to describe the wave nature + + + align:start position:0% +solve to describe the wave nature +of quantum mechanics and and just to + + align:start position:0% +of quantum mechanics and and just to + + + align:start position:0% +of quantum mechanics and and just to +to end so on on monday we'll pick up + + align:start position:0% +to end so on on monday we'll pick up + + + align:start position:0% +to end so on on monday we'll pick up +with schrodinger's equation + + align:start position:0% +with schrodinger's equation + + + align:start position:0% +with schrodinger's equation +for the atom you know the question is + + align:start position:0% +for the atom you know the question is + + + align:start position:0% +for the atom you know the question is +what does this all mean for chemistry + + align:start position:0% +what does this all mean for chemistry + + + align:start position:0% +what does this all mean for chemistry +what does this mean + + align:start position:0% + + + + align:start position:0% + +we're not i'm not teaching you quantum + + align:start position:0% +we're not i'm not teaching you quantum + + + align:start position:0% +we're not i'm not teaching you quantum +i'm not teaching you quantum just so you + + align:start position:0% +i'm not teaching you quantum just so you + + + align:start position:0% +i'm not teaching you quantum just so you +know quantum in isolation i'm telling + + align:start position:0% +know quantum in isolation i'm telling + + + align:start position:0% +know quantum in isolation i'm telling +you about it + + align:start position:0% +you about it + + + align:start position:0% +you about it +because it completely revolutionized + + align:start position:0% +because it completely revolutionized + + + align:start position:0% +because it completely revolutionized +chemistry and and that is where we will + + align:start position:0% +chemistry and and that is where we will + + + align:start position:0% +chemistry and and that is where we will +answer that question + + align:start position:0% +answer that question + + + align:start position:0% +answer that question +on monday have a really good weekend + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/s67DO7fFM14.txt b/s67DO7fFM14.txt new file mode 100644 index 0000000000000000000000000000000000000000..a5192c1f9028a88158a71eb21e9fe3fd248f7df1 --- /dev/null +++ b/s67DO7fFM14.txt @@ -0,0 +1,3843 @@ +align:start position:0% + +there's no pizza for me cuz I'm going to + + align:start position:0% +there's no pizza for me cuz I'm going to + + + align:start position:0% +there's no pizza for me cuz I'm going to +talk about Oshkosh + + align:start position:0% + + + + align:start position:0% + +so what is it it's end of July every + + align:start position:0% +so what is it it's end of July every + + + align:start position:0% +so what is it it's end of July every +year and a big physically big but + + align:start position:0% +year and a big physically big but + + + align:start position:0% +year and a big physically big but +otherwise not very busy Airport in + + align:start position:0% +otherwise not very busy Airport in + + + align:start position:0% +otherwise not very busy Airport in +Wisconsin and about 10,000 airplanes + + align:start position:0% +Wisconsin and about 10,000 airplanes + + + align:start position:0% +Wisconsin and about 10,000 airplanes +come in people camp out people hang out + + align:start position:0% +come in people camp out people hang out + + + align:start position:0% +come in people camp out people hang out +usually at least a hundred thousand + + align:start position:0% +usually at least a hundred thousand + + + align:start position:0% +usually at least a hundred thousand +people a day there's a Boeing there's a + + align:start position:0% +people a day there's a Boeing there's a + + + align:start position:0% +people a day there's a Boeing there's a +c-17 cargo plane a lot of experimentals + + align:start position:0% +c-17 cargo plane a lot of experimentals + + + align:start position:0% +c-17 cargo plane a lot of experimentals +it's founded by the Experimental + + align:start position:0% +it's founded by the Experimental + + + align:start position:0% +it's founded by the Experimental +Aircraft Association so there's a lot of + + align:start position:0% +Aircraft Association so there's a lot of + + + align:start position:0% +Aircraft Association so there's a lot of +people who are passionate about home + + align:start position:0% +people who are passionate about home + + + align:start position:0% +people who are passionate about home +building there you can see all the + + align:start position:0% +building there you can see all the + + + align:start position:0% +building there you can see all the +airplanes parked + + align:start position:0% + + + + align:start position:0% + +yeah there's 12,000 camping sites 40,000 + + align:start position:0% +yeah there's 12,000 camping sites 40,000 + + + align:start position:0% +yeah there's 12,000 camping sites 40,000 +campers there's 1,500 workshops and + + align:start position:0% +campers there's 1,500 workshops and + + + align:start position:0% +campers there's 1,500 workshops and +seminars that you can take to learn or + + align:start position:0% +seminars that you can take to learn or + + + align:start position:0% +seminars that you can take to learn or +you can just walk around and talk to + + align:start position:0% +you can just walk around and talk to + + + align:start position:0% +you can just walk around and talk to +people and hang out so I planned this + + align:start position:0% +people and hang out so I planned this + + + align:start position:0% +people and hang out so I planned this +trip for me and my friend ray he's a + + align:start position:0% +trip for me and my friend ray he's a + + + align:start position:0% +trip for me and my friend ray he's a +helicopter pilot from Ireland and the + + align:start position:0% +helicopter pilot from Ireland and the + + + align:start position:0% +helicopter pilot from Ireland and the +idea was to fly to Niagara Falls and + + align:start position:0% +idea was to fly to Niagara Falls and + + + align:start position:0% +idea was to fly to Niagara Falls and +show him Niagara Falls and on the way + + align:start position:0% +show him Niagara Falls and on the way + + + align:start position:0% +show him Niagara Falls and on the way +back up to Mackinac Island they saw + + align:start position:0% +back up to Mackinac Island they saw + + + align:start position:0% +back up to Mackinac Island they saw +automobiles about 120 years ago and they + + align:start position:0% +automobiles about 120 years ago and they + + + align:start position:0% +automobiles about 120 years ago and they +said this is a terrible technology + + align:start position:0% +said this is a terrible technology + + + align:start position:0% +said this is a terrible technology +that'll ruin everything + + align:start position:0% +that'll ruin everything + + + align:start position:0% +that'll ruin everything +they banned cars the only powered air + + align:start position:0% +they banned cars the only powered air + + + align:start position:0% +they banned cars the only powered air +the only powered vehicle you can legally + + align:start position:0% +the only powered vehicle you can legally + + + align:start position:0% +the only powered vehicle you can legally +have on Mackinac Island is an aircraft + + align:start position:0% +have on Mackinac Island is an aircraft + + + align:start position:0% +have on Mackinac Island is an aircraft +they do have an airport anyway in the + + align:start position:0% +they do have an airport anyway in the + + + align:start position:0% +they do have an airport anyway in the +back and we were gonna go to Toronto as + + align:start position:0% +back and we were gonna go to Toronto as + + + align:start position:0% +back and we were gonna go to Toronto as +well so we had to get all this stuff + + align:start position:0% +well so we had to get all this stuff + + + align:start position:0% +well so we had to get all this stuff +ready for international flying I had it + + align:start position:0% +ready for international flying I had it + + + align:start position:0% +ready for international flying I had it +all carefully planned out where we're + + align:start position:0% +all carefully planned out where we're + + + align:start position:0% +all carefully planned out where we're +gonna have 540 pounds of stuff which is + + align:start position:0% +gonna have 540 pounds of stuff which is + + + align:start position:0% +gonna have 540 pounds of stuff which is +right at the payload of the airplane + + align:start position:0% +right at the payload of the airplane + + + align:start position:0% +right at the payload of the airplane +with full fuel but then Alex Anna who + + align:start position:0% +with full fuel but then Alex Anna who + + + align:start position:0% +with full fuel but then Alex Anna who +was just here she's an aerobatic pilot + + align:start position:0% +was just here she's an aerobatic pilot + + + align:start position:0% +was just here she's an aerobatic pilot +at East Coast Aero clubs she said she + + align:start position:0% +at East Coast Aero clubs she said she + + + align:start position:0% +at East Coast Aero clubs she said she +wanted to come too so then we had we had + + align:start position:0% +wanted to come too so then we had we had + + + align:start position:0% +wanted to come too so then we had we had +to add a fuel stop there's all our merry + + align:start position:0% +to add a fuel stop there's all our merry + + + align:start position:0% +to add a fuel stop there's all our merry +band of three people there's a whole + + align:start position:0% +band of three people there's a whole + + + align:start position:0% +band of three people there's a whole +bunch of camping gear in the back that + + align:start position:0% +bunch of camping gear in the back that + + + align:start position:0% +bunch of camping gear in the back that +you can't quite see option Cox becomes + + align:start position:0% +you can't quite see option Cox becomes + + + align:start position:0% +you can't quite see option Cox becomes +temporarily the business busiest airport + + align:start position:0% +temporarily the business busiest airport + + + align:start position:0% +temporarily the business busiest airport +in the world and you might say well how + + align:start position:0% +in the world and you might say well how + + + align:start position:0% +in the world and you might say well how +can that be O'Hare has more flights but + + align:start position:0% +can that be O'Hare has more flights but + + + align:start position:0% +can that be O'Hare has more flights but +their only option has only open about 10 + + align:start position:0% +their only option has only open about 10 + + + align:start position:0% +their only option has only open about 10 +hours a day because they close the + + align:start position:0% +hours a day because they close the + + + align:start position:0% +hours a day because they close the +airport at night and they close it also + + align:start position:0% +airport at night and they close it also + + + align:start position:0% +airport at night and they close it also +for a few hours + + align:start position:0% +for a few hours + + + align:start position:0% +for a few hours +every afternoon for an airshow this is + + align:start position:0% + + + + align:start position:0% + +somebody's iPad + + align:start position:0% +somebody's iPad + + + align:start position:0% +somebody's iPad +I think screen capture of airplanes + + align:start position:0% +I think screen capture of airplanes + + + align:start position:0% +I think screen capture of airplanes +flying in and around Oshkosh and these + + align:start position:0% +flying in and around Oshkosh and these + + + align:start position:0% +flying in and around Oshkosh and these +are only the ones with the newest ad s + + align:start position:0% +are only the ones with the newest ad s + + + align:start position:0% +are only the ones with the newest ad s +be out transponders so it doesn't show + + align:start position:0% +be out transponders so it doesn't show + + + align:start position:0% +be out transponders so it doesn't show +probably this is probably only 20 + + align:start position:0% +probably this is probably only 20 + + + align:start position:0% +probably this is probably only 20 +percent of the total airplanes you have + + align:start position:0% +percent of the total airplanes you have + + + align:start position:0% +percent of the total airplanes you have +special arrival rules if you're not a + + align:start position:0% +special arrival rules if you're not a + + + align:start position:0% +special arrival rules if you're not a + then you have to fly and visually + + align:start position:0% + then you have to fly and visually + + + align:start position:0% + then you have to fly and visually +circle around until it's your turn and + + align:start position:0% +circle around until it's your turn and + + + align:start position:0% +circle around until it's your turn and +then they'll tell you you can't use the + + align:start position:0% +then they'll tell you you can't use the + + + align:start position:0% +then they'll tell you you can't use the +whole runway you have to land on one of + + align:start position:0% +whole runway you have to land on one of + + + align:start position:0% +whole runway you have to land on one of +these dots they'll say land on the green + + align:start position:0% +these dots they'll say land on the green + + + align:start position:0% +these dots they'll say land on the green +dot if you are a you file IFR get + + align:start position:0% +dot if you are a you file IFR get + + + align:start position:0% +dot if you are a you file IFR get +your IFR reservation when this daus + + align:start position:0% +your IFR reservation when this daus + + + align:start position:0% +your IFR reservation when this daus +grade computer system confirm it with + + align:start position:0% +grade computer system confirm it with + + + align:start position:0% +grade computer system confirm it with +this daus grade computer system that + + align:start position:0% +this daus grade computer system that + + + align:start position:0% +this daus grade computer system that +nobody else wants to deal with and then + + align:start position:0% +nobody else wants to deal with and then + + + align:start position:0% +nobody else wants to deal with and then +you get the whole runway and you just + + align:start position:0% +you get the whole runway and you just + + + align:start position:0% +you get the whole runway and you just +land all right here's a picture of the + + align:start position:0% +land all right here's a picture of the + + + align:start position:0% +land all right here's a picture of the +multifunction display and no actually I + + align:start position:0% +multifunction display and no actually I + + + align:start position:0% +multifunction display and no actually I +guess this was some flat fried up + + align:start position:0% +guess this was some flat fried up + + + align:start position:0% +guess this was some flat fried up +FlightAware later this shows that we + + align:start position:0% +FlightAware later this shows that we + + + align:start position:0% +FlightAware later this shows that we +diverted a bit from Bedford we ended up + + align:start position:0% +diverted a bit from Bedford we ended up + + + align:start position:0% +diverted a bit from Bedford we ended up +going up to Watertown New York so we + + align:start position:0% +going up to Watertown New York so we + + + align:start position:0% +going up to Watertown New York so we +didn't we could have legally where + + align:start position:0% +didn't we could have legally where + + + align:start position:0% +didn't we could have legally where +instrument-rated and everything we could + + align:start position:0% +instrument-rated and everything we could + + + align:start position:0% +instrument-rated and everything we could +have flown through this you know these + + align:start position:0% +have flown through this you know these + + + align:start position:0% +have flown through this you know these +rain showers but it's always smarter + + align:start position:0% +rain showers but it's always smarter + + + align:start position:0% +rain showers but it's always smarter +just to go around if you can okay so we + + align:start position:0% +just to go around if you can okay so we + + + align:start position:0% +just to go around if you can okay so we +flew over Niagara Falls we landed we had + + align:start position:0% +flew over Niagara Falls we landed we had + + + align:start position:0% +flew over Niagara Falls we landed we had +that whole runway to ourself about + + align:start position:0% +that whole runway to ourself about + + + align:start position:0% +that whole runway to ourself about +10,000 foot runway and it's actually + + align:start position:0% +10,000 foot runway and it's actually + + + align:start position:0% +10,000 foot runway and it's actually +oriented east-west so we actually just + + align:start position:0% +oriented east-west so we actually just + + + align:start position:0% +oriented east-west so we actually just +essentially we could have done the same + + align:start position:0% +essentially we could have done the same + + + align:start position:0% +essentially we could have done the same +heading basically from Hanscom field all + + align:start position:0% +heading basically from Hanscom field all + + + align:start position:0% +heading basically from Hanscom field all +the way to the end of the runway and + + align:start position:0% +the way to the end of the runway and + + + align:start position:0% +the way to the end of the runway and +where we turned off you get there and + + align:start position:0% +where we turned off you get there and + + + align:start position:0% +where we turned off you get there and +there's just on a thirty p-51 Mustangs + + align:start position:0% +there's just on a thirty p-51 Mustangs + + + align:start position:0% +there's just on a thirty p-51 Mustangs +right next to your tent there are people + + align:start position:0% +right next to your tent there are people + + + align:start position:0% +right next to your tent there are people +building this one-week Wonder an RV kit + + align:start position:0% +building this one-week Wonder an RV kit + + + align:start position:0% +building this one-week Wonder an RV kit +where you get to pull rivets Oksana's + + align:start position:0% +where you get to pull rivets Oksana's + + + align:start position:0% +where you get to pull rivets Oksana's +actually here and she can tell you about + + align:start position:0% +actually here and she can tell you about + + + align:start position:0% +actually here and she can tell you about +her experience helping to build that + + align:start position:0% +her experience helping to build that + + + align:start position:0% +her experience helping to build that +airplane + + align:start position:0% +airplane + + + align:start position:0% +airplane +there's your b-1 bomber I love the + + align:start position:0% +there's your b-1 bomber I love the + + + align:start position:0% +there's your b-1 bomber I love the +antiques here's one from the late 20s a + + align:start position:0% +antiques here's one from the late 20s a + + + align:start position:0% +antiques here's one from the late 20s a +Lincoln Age airplane that has been + + align:start position:0% +Lincoln Age airplane that has been + + + align:start position:0% +Lincoln Age airplane that has been +recently restored and flying there's + + align:start position:0% +recently restored and flying there's + + + align:start position:0% +recently restored and flying there's +that replica autogyro beautiful Cessna + + align:start position:0% +that replica autogyro beautiful Cessna + + + align:start position:0% +that replica autogyro beautiful Cessna +172 mold piper Comanche there on the + + align:start position:0% +172 mold piper Comanche there on the + + + align:start position:0% +172 mold piper Comanche there on the +right + + align:start position:0% +right + + + align:start position:0% +right +there's not a whole lot of helicopter + + align:start position:0% +there's not a whole lot of helicopter + + + align:start position:0% +there's not a whole lot of helicopter +action there's a little bit this is + + align:start position:0% +action there's a little bit this is + + + align:start position:0% +action there's a little bit this is +what's called a safari helicopter kit + + align:start position:0% +what's called a safari helicopter kit + + + align:start position:0% +what's called a safari helicopter kit +that's how you know that you have real + + align:start position:0% +that's how you know that you have real + + + align:start position:0% +that's how you know that you have real +confidence in your mechanical abilities + + align:start position:0% +confidence in your mechanical abilities + + + align:start position:0% +confidence in your mechanical abilities +if you build and then fly your own + + align:start position:0% +if you build and then fly your own + + + align:start position:0% +if you build and then fly your own +helicopter Piper Cub this is a guy who + + align:start position:0% +helicopter Piper Cub this is a guy who + + + align:start position:0% +helicopter Piper Cub this is a guy who +stuck a Pratt and Whitney I think it's a + + align:start position:0% +stuck a Pratt and Whitney I think it's a + + + align:start position:0% +stuck a Pratt and Whitney I think it's a +Pratt pt6 engine into a Polish Wilgus + + align:start position:0% +Pratt pt6 engine into a Polish Wilgus + + + align:start position:0% +Pratt pt6 engine into a Polish Wilgus +short field landing airplane he added + + align:start position:0% +short field landing airplane he added + + + align:start position:0% +short field landing airplane he added +fuel tanks it's such a fuel log now that + + align:start position:0% +fuel tanks it's such a fuel log now that + + + align:start position:0% +fuel tanks it's such a fuel log now that +they had to add extra fuel capacity in + + align:start position:0% +they had to add extra fuel capacity in + + + align:start position:0% +they had to add extra fuel capacity in +the struts and flies all around the West + + align:start position:0% +the struts and flies all around the West + + + align:start position:0% +the struts and flies all around the West +going camping with his family all right + + align:start position:0% +going camping with his family all right + + + align:start position:0% +going camping with his family all right +and that's called a traveler there were + + align:start position:0% +and that's called a traveler there were + + + align:start position:0% +and that's called a traveler there were +a bunch of these so these are airplanes + + align:start position:0% +a bunch of these so these are airplanes + + + align:start position:0% +a bunch of these so these are airplanes +from the 20s people are just using them + + align:start position:0% +from the 20s people are just using them + + + align:start position:0% +from the 20s people are just using them +for transportation throwing a friend in + + align:start position:0% +for transportation throwing a friend in + + + align:start position:0% +for transportation throwing a friend in +the back maybe and a tent and that going + + align:start position:0% +the back maybe and a tent and that going + + + align:start position:0% +the back maybe and a tent and that going +and camping out of Oshkosh so I think + + align:start position:0% +and camping out of Oshkosh so I think + + + align:start position:0% +and camping out of Oshkosh so I think +that's pretty cool all right there are + + align:start position:0% +that's pretty cool all right there are + + + align:start position:0% +that's pretty cool all right there are +only five of these Piaggio seaplanes P + + align:start position:0% +only five of these Piaggio seaplanes P + + + align:start position:0% +only five of these Piaggio seaplanes P +31 thirty Six's that still exist out of + + align:start position:0% +31 thirty Six's that still exist out of + + + align:start position:0% +31 thirty Six's that still exist out of +63 that were built from 1948 to 1961 I + + align:start position:0% +63 that were built from 1948 to 1961 I + + + align:start position:0% +63 that were built from 1948 to 1961 I +saw two of them parked next to each + + align:start position:0% +saw two of them parked next to each + + + align:start position:0% +saw two of them parked next to each +other Oshkosh that's what makes it a + + align:start position:0% +other Oshkosh that's what makes it a + + + align:start position:0% +other Oshkosh that's what makes it a +unique experience here's some kind of + + align:start position:0% +unique experience here's some kind of + + + align:start position:0% +unique experience here's some kind of +airplane doing a simulated bombing run + + align:start position:0% +airplane doing a simulated bombing run + + + align:start position:0% +airplane doing a simulated bombing run +meanwhile a family is there and their + + align:start position:0% +meanwhile a family is there and their + + + align:start position:0% +meanwhile a family is there and their +personal dc-3 camping out here's our + + align:start position:0% +personal dc-3 camping out here's our + + + align:start position:0% +personal dc-3 camping out here's our +little plane and the $99 tent from + + align:start position:0% +little plane and the $99 tent from + + + align:start position:0% +little plane and the $99 tent from +Costco it seemed like a great idea + + align:start position:0% +Costco it seemed like a great idea + + + align:start position:0% +Costco it seemed like a great idea +at the time I think we have a slide on + + align:start position:0% +at the time I think we have a slide on + + + align:start position:0% +at the time I think we have a slide on +that okay this kind of summarizes 8:00 + + align:start position:0% +that okay this kind of summarizes 8:00 + + + align:start position:0% +that okay this kind of summarizes 8:00 +this is the unfortunate state of general + + align:start position:0% +this is the unfortunate state of general + + + align:start position:0% +this is the unfortunate state of general +aviation now so we have the innovation + + align:start position:0% +aviation now so we have the innovation + + + align:start position:0% +aviation now so we have the innovation +showcase and right in front of it a + + align:start position:0% +showcase and right in front of it a + + + align:start position:0% +showcase and right in front of it a +piper Seminole which I think was + + align:start position:0% +piper Seminole which I think was + + + align:start position:0% +piper Seminole which I think was +certified in the 1970s and certainly a + + align:start position:0% +certified in the 1970s and certainly a + + + align:start position:0% +certified in the 1970s and certainly a +derivative of things going back a lot + + align:start position:0% +derivative of things going back a lot + + + align:start position:0% +derivative of things going back a lot +harder than that + + align:start position:0% +harder than that + + + align:start position:0% +harder than that +there were some interesting talks there + + align:start position:0% +there were some interesting talks there + + + align:start position:0% +there were some interesting talks there +some heavy-hitters this guy Pat Anderson + + align:start position:0% +some heavy-hitters this guy Pat Anderson + + + align:start position:0% +some heavy-hitters this guy Pat Anderson +is a professor at embry-riddle and he + + align:start position:0% +is a professor at embry-riddle and he + + + align:start position:0% +is a professor at embry-riddle and he +said actually that we haven't really + + align:start position:0% +said actually that we haven't really + + + align:start position:0% +said actually that we haven't really +seen anything in the electric aircraft + + align:start position:0% +seen anything in the electric aircraft + + + align:start position:0% +seen anything in the electric aircraft +world because in the early days of Jets + + align:start position:0% +world because in the early days of Jets + + + align:start position:0% +world because in the early days of Jets +they just took these piston airframes + + align:start position:0% +they just took these piston airframes + + + align:start position:0% +they just took these piston airframes +and stuck a jet engine in them and they + + align:start position:0% +and stuck a jet engine in them and they + + + align:start position:0% +and stuck a jet engine in them and they +didn't perform that differently from the + + align:start position:0% +didn't perform that differently from the + + + align:start position:0% +didn't perform that differently from the +piston fighters but then you know five + + align:start position:0% +piston fighters but then you know five + + + align:start position:0% +piston fighters but then you know five +years later they had the swept wings and + + align:start position:0% +years later they had the swept wings and + + + align:start position:0% +years later they had the swept wings and +we would recognize as the modern fighter + + align:start position:0% +we would recognize as the modern fighter + + + align:start position:0% +we would recognize as the modern fighter +jet so it completely was it was the jet + + align:start position:0% +jet so it completely was it was the jet + + + align:start position:0% +jet so it completely was it was the jet +engine did completely transform the + + align:start position:0% +engine did completely transform the + + + align:start position:0% +engine did completely transform the +aircraft but not immediately so he said + + align:start position:0% +aircraft but not immediately so he said + + + align:start position:0% +aircraft but not immediately so he said +you know you're seeing some of this now + + align:start position:0% +you know you're seeing some of this now + + + align:start position:0% +you know you're seeing some of this now +our people take a little two-seat + + align:start position:0% +our people take a little two-seat + + + align:start position:0% +our people take a little two-seat +trainer and they remove the piston + + align:start position:0% +trainer and they remove the piston + + + align:start position:0% +trainer and they remove the piston +engine and put in a electric motor with + + align:start position:0% +engine and put in a electric motor with + + + align:start position:0% +engine and put in a electric motor with +the propeller but that's not really what + + align:start position:0% +the propeller but that's not really what + + + align:start position:0% +the propeller but that's not really what +what we're really going to see is are + + align:start position:0% +what we're really going to see is are + + + align:start position:0% +what we're really going to see is are +things that are much more like drones + + align:start position:0% +things that are much more like drones + + + align:start position:0% +things that are much more like drones +there's an uber there was a guy from + + align:start position:0% +there's an uber there was a guy from + + + align:start position:0% +there's an uber there was a guy from +uber that was very interesting + + align:start position:0% +uber that was very interesting + + + align:start position:0% +uber that was very interesting +uber has aeronautical engineers working + + align:start position:0% +uber has aeronautical engineers working + + + align:start position:0% +uber has aeronautical engineers working +for them designing aircraft and then + + align:start position:0% +for them designing aircraft and then + + + align:start position:0% +for them designing aircraft and then +releasing the designs for free hoping + + align:start position:0% +releasing the designs for free hoping + + + align:start position:0% +releasing the designs for free hoping +that well people will make them they're + + align:start position:0% +that well people will make them they're + + + align:start position:0% +that well people will make them they're +claiming that they're gonna I don't know + + align:start position:0% +claiming that they're gonna I don't know + + + align:start position:0% +claiming that they're gonna I don't know +they gotta I gotta pay somebody off in + + align:start position:0% +they gotta I gotta pay somebody off in + + + align:start position:0% +they gotta I gotta pay somebody off in +the government to make this happen 2023 + + align:start position:0% +the government to make this happen 2023 + + + align:start position:0% +the government to make this happen 2023 +they say they're gonna be operating in + + align:start position:0% +they say they're gonna be operating in + + + align:start position:0% +they say they're gonna be operating in +Los Angeles their idea is that you know + + align:start position:0% +Los Angeles their idea is that you know + + + align:start position:0% +Los Angeles their idea is that you know +the world is going to be so congested + + align:start position:0% +the world is going to be so congested + + + align:start position:0% +the world is going to be so congested +that people will pay up happily to hop + + align:start position:0% +that people will pay up happily to hop + + + align:start position:0% +that people will pay up happily to hop +over the congestion and in relatively + + align:start position:0% +over the congestion and in relatively + + + align:start position:0% +over the congestion and in relatively +short hops so ubers putting a lot of + + align:start position:0% +short hops so ubers putting a lot of + + + align:start position:0% +short hops so ubers putting a lot of +money into this they have some partners + + align:start position:0% +money into this they have some partners + + + align:start position:0% +money into this they have some partners +like Airbus pipistrelle the Slovenian + + align:start position:0% +like Airbus pipistrelle the Slovenian + + + align:start position:0% +like Airbus pipistrelle the Slovenian +company we'll see what happens so some + + align:start position:0% +company we'll see what happens so some + + + align:start position:0% +company we'll see what happens so some +round-the-world pilots were there + + align:start position:0% +round-the-world pilots were there + + + align:start position:0% +round-the-world pilots were there +actually I don't know how many you guys + + align:start position:0% +actually I don't know how many you guys + + + align:start position:0% +actually I don't know how many you guys +know this but Matt Guf Miller who was an + + align:start position:0% +know this but Matt Guf Miller who was an + + + align:start position:0% +know this but Matt Guf Miller who was an +MIT between freshman and sophomore years + + align:start position:0% +MIT between freshman and sophomore years + + + align:start position:0% +MIT between freshman and sophomore years +became the youngest person ever to fly + + align:start position:0% +became the youngest person ever to fly + + + align:start position:0% +became the youngest person ever to fly +around the world in a Beechcraft Bonanza + + align:start position:0% +around the world in a Beechcraft Bonanza + + + align:start position:0% +around the world in a Beechcraft Bonanza +I mean he was he was in there bonanza + + align:start position:0% +I mean he was he was in there bonanza + + + align:start position:0% +I mean he was he was in there bonanza +and he he was the youngest person to fly + + align:start position:0% +and he he was the youngest person to fly + + + align:start position:0% +and he he was the youngest person to fly +around the world but there's also at + + align:start position:0% +around the world but there's also at + + + align:start position:0% +around the world but there's also at +Oshkosh we met this guy dick Rutan who + + align:start position:0% +Oshkosh we met this guy dick Rutan who + + + align:start position:0% +Oshkosh we met this guy dick Rutan who +flew around the world + + align:start position:0% +flew around the world + + + align:start position:0% +flew around the world +non-stop unrefueled in a clean design by + + align:start position:0% +non-stop unrefueled in a clean design by + + + align:start position:0% +non-stop unrefueled in a clean design by +his brother Burt Rutan what else is Burt + + align:start position:0% +his brother Burt Rutan what else is Burt + + + align:start position:0% +his brother Burt Rutan what else is Burt +Rutan famous for besides designing + + align:start position:0% +Rutan famous for besides designing + + + align:start position:0% +Rutan famous for besides designing +aircraft does anybody know + + align:start position:0% +aircraft does anybody know + + + align:start position:0% +aircraft does anybody know +what spacecraft that's true but yeah + + align:start position:0% +what spacecraft that's true but yeah + + + align:start position:0% +what spacecraft that's true but yeah +spacecraft and aircraft but what else + + align:start position:0% + + + + align:start position:0% + +canard plane so there are airplanes + + align:start position:0% +canard plane so there are airplanes + + + align:start position:0% +canard plane so there are airplanes +climate change denial look it up he's + + align:start position:0% +climate change denial look it up he's + + + align:start position:0% +climate change denial look it up he's +got like a hundred page book about the + + align:start position:0% +got like a hundred page book about the + + + align:start position:0% +got like a hundred page book about the +scientific fraud of climate change but + + align:start position:0% +scientific fraud of climate change but + + + align:start position:0% +scientific fraud of climate change but +anyway dick Rutan the other interesting + + align:start position:0% +anyway dick Rutan the other interesting + + + align:start position:0% +anyway dick Rutan the other interesting +thing is before this nine-day flight he + + align:start position:0% +thing is before this nine-day flight he + + + align:start position:0% +thing is before this nine-day flight he +was engaged to be married to Jeana + + align:start position:0% +was engaged to be married to Jeana + + + align:start position:0% +was engaged to be married to Jeana +Jaeger and supposedly I what I heard was + + align:start position:0% +Jaeger and supposedly I what I heard was + + + align:start position:0% +Jaeger and supposedly I what I heard was +it at Oshkosh was they have not spoken + + align:start position:0% +it at Oshkosh was they have not spoken + + + align:start position:0% +it at Oshkosh was they have not spoken +since they landed in 1986 + + align:start position:0% +since they landed in 1986 + + + align:start position:0% +since they landed in 1986 +so in nine days there can be quite a + + align:start position:0% +so in nine days there can be quite a + + + align:start position:0% +so in nine days there can be quite a +change in a relationship apparently we + + align:start position:0% +change in a relationship apparently we + + + align:start position:0% +change in a relationship apparently we +met this this pilot shyest hawaii's I + + align:start position:0% +met this this pilot shyest hawaii's I + + + align:start position:0% +met this this pilot shyest hawaii's I +don't know if that's the correct + + align:start position:0% +don't know if that's the correct + + + align:start position:0% +don't know if that's the correct +pronunciation she grew up in California + + align:start position:0% +pronunciation she grew up in California + + + align:start position:0% +pronunciation she grew up in California +and learned to fly relatively recently + + align:start position:0% +and learned to fly relatively recently + + + align:start position:0% +and learned to fly relatively recently +and she also flew a bonanza all the way + + align:start position:0% +and she also flew a bonanza all the way + + + align:start position:0% +and she also flew a bonanza all the way +around the world over 145 days so that + + align:start position:0% +around the world over 145 days so that + + + align:start position:0% +around the world over 145 days so that +was interesting she actually said it + + align:start position:0% +was interesting she actually said it + + + align:start position:0% +was interesting she actually said it +gets a little bit easier once you're out + + align:start position:0% +gets a little bit easier once you're out + + + align:start position:0% +gets a little bit easier once you're out +over the ocean from a weather point of + + align:start position:0% +over the ocean from a weather point of + + + align:start position:0% +over the ocean from a weather point of +view she said except for the + + align:start position:0% +view she said except for the + + + align:start position:0% +view she said except for the +Intertropical Convergence of the equator + + align:start position:0% +Intertropical Convergence of the equator + + + align:start position:0% +Intertropical Convergence of the equator +most weather is kind of a phenomenon of + + align:start position:0% +most weather is kind of a phenomenon of + + + align:start position:0% +most weather is kind of a phenomenon of +being overland to me the most impressive + + align:start position:0% +being overland to me the most impressive + + + align:start position:0% +being overland to me the most impressive +round-the-world pilot though was + + align:start position:0% +round-the-world pilot though was + + + align:start position:0% +round-the-world pilot though was +actually an Italian guy that I met he + + align:start position:0% +actually an Italian guy that I met he + + + align:start position:0% +actually an Italian guy that I met he +was in a Cirrus sr22 and he just flies + + align:start position:0% +was in a Cirrus sr22 and he just flies + + + align:start position:0% +was in a Cirrus sr22 and he just flies +to Oshkosh every year he just loads up + + align:start position:0% +to Oshkosh every year he just loads up + + + align:start position:0% +to Oshkosh every year he just loads up +in Italy turns the key and goes every + + align:start position:0% +in Italy turns the key and goes every + + + align:start position:0% +in Italy turns the key and goes every +year flies over the Atlantic and then + + align:start position:0% +year flies over the Atlantic and then + + + align:start position:0% +year flies over the Atlantic and then +flies back to Italy when it's over so I + + align:start position:0% +flies back to Italy when it's over so I + + + align:start position:0% +flies back to Italy when it's over so I +thought you know that is actually the + + align:start position:0% +thought you know that is actually the + + + align:start position:0% +thought you know that is actually the +coolest thing when it's not you know + + align:start position:0% +coolest thing when it's not you know + + + align:start position:0% +coolest thing when it's not you know +even an adventure you're not gonna write + + align:start position:0% +even an adventure you're not gonna write + + + align:start position:0% +even an adventure you're not gonna write +about it you're not gonna build a + + align:start position:0% +about it you're not gonna build a + + + align:start position:0% +about it you're not gonna build a +webpage you're not gonna say you're you + + align:start position:0% +webpage you're not gonna say you're you + + + align:start position:0% +webpage you're not gonna say you're you +know changing the world or helping to + + align:start position:0% +know changing the world or helping to + + + align:start position:0% +know changing the world or helping to +achieve something you're not gonna set a + + align:start position:0% +achieve something you're not gonna set a + + + align:start position:0% +achieve something you're not gonna set a +record you're just using your airplane + + align:start position:0% +record you're just using your airplane + + + align:start position:0% +record you're just using your airplane +for transportation you want to get to + + align:start position:0% +for transportation you want to get to + + + align:start position:0% +for transportation you want to get to +Oshkosh you have an airplane so why + + align:start position:0% +Oshkosh you have an airplane so why + + + align:start position:0% +Oshkosh you have an airplane so why +should the fact that you're on a + + align:start position:0% +should the fact that you're on a + + + align:start position:0% +should the fact that you're on a +different continent stopped you from + + align:start position:0% +different continent stopped you from + + + align:start position:0% +different continent stopped you from +doing it you know a lot of people have + + align:start position:0% +doing it you know a lot of people have + + + align:start position:0% +doing it you know a lot of people have +stopped doing home projects home repairs + + align:start position:0% +stopped doing home projects home repairs + + + align:start position:0% +stopped doing home projects home repairs +so Oshkosh they actually have people to + + align:start position:0% +so Oshkosh they actually have people to + + + align:start position:0% +so Oshkosh they actually have people to +teach kids you know how to hammer how to + + align:start position:0% +teach kids you know how to hammer how to + + + align:start position:0% +teach kids you know how to hammer how to +drill how to cut sheet metal there's a + + align:start position:0% +drill how to cut sheet metal there's a + + + align:start position:0% +drill how to cut sheet metal there's a +lot of great workshops there for kids we + + align:start position:0% +lot of great workshops there for kids we + + + align:start position:0% +lot of great workshops there for kids we +were over by the Pioneer Airport and the + + align:start position:0% +were over by the Pioneer Airport and the + + + align:start position:0% +were over by the Pioneer Airport and the +museum + + align:start position:0% +museum + + + align:start position:0% +museum +here's the museum they have a replica + + align:start position:0% +here's the museum they have a replica + + + align:start position:0% +here's the museum they have a replica +right flyer + + align:start position:0% +right flyer + + + align:start position:0% +right flyer +the whole area devoted to the route and + + align:start position:0% +the whole area devoted to the route and + + + align:start position:0% +the whole area devoted to the route and +designs I don't know how many I don't + + align:start position:0% +designs I don't know how many I don't + + + align:start position:0% +designs I don't know how many I don't +know how many you know the MIT spin-off + + align:start position:0% +know how many you know the MIT spin-off + + + align:start position:0% +know how many you know the MIT spin-off +Terrafugia I guess I think it was 12 at + + align:start position:0% +Terrafugia I guess I think it was 12 at + + + align:start position:0% +Terrafugia I guess I think it was 12 at +least 12 years ago they said they were + + align:start position:0% +least 12 years ago they said they were + + + align:start position:0% +least 12 years ago they said they were +gonna build a flying car so I took a + + align:start position:0% +gonna build a flying car so I took a + + + align:start position:0% +gonna build a flying car so I took a +picture of this 1949 Taylor Aero car + + align:start position:0% +picture of this 1949 Taylor Aero car + + + align:start position:0% +picture of this 1949 Taylor Aero car +which is actually a certificated flying + + align:start position:0% +which is actually a certificated flying + + + align:start position:0% +which is actually a certificated flying +car and unfairly associated with + + align:start position:0% +car and unfairly associated with + + + align:start position:0% +car and unfairly associated with +Terrafugia okay so this guy is kind of + + align:start position:0% +Terrafugia okay so this guy is kind of + + + align:start position:0% +Terrafugia okay so this guy is kind of +an inspiration I think Paul po Perez nee + + align:start position:0% +an inspiration I think Paul po Perez nee + + + align:start position:0% +an inspiration I think Paul po Perez nee +the founder of the Experimental Aircraft + + align:start position:0% +the founder of the Experimental Aircraft + + + align:start position:0% +the founder of the Experimental Aircraft +Association he flew the most expensive + + align:start position:0% +Association he flew the most expensive + + + align:start position:0% +Association he flew the most expensive +and highest performance aircraft of the + + align:start position:0% +and highest performance aircraft of the + + + align:start position:0% +and highest performance aircraft of the +day he flew the p-51 Mustang the p-38 + + align:start position:0% +day he flew the p-51 Mustang the p-38 + + + align:start position:0% +day he flew the p-51 Mustang the p-38 +lightning and then he came home and said + + align:start position:0% +lightning and then he came home and said + + + align:start position:0% +lightning and then he came home and said +well what's cool to do after flying you + + align:start position:0% +well what's cool to do after flying you + + + align:start position:0% +well what's cool to do after flying you +know a 12,000 pound plus p-51 Mustang + + align:start position:0% +know a 12,000 pound plus p-51 Mustang + + + align:start position:0% +know a 12,000 pound plus p-51 Mustang +why not just you know go to the basement + + align:start position:0% +why not just you know go to the basement + + + align:start position:0% +why not just you know go to the basement +get some plywood nail it together and + + align:start position:0% +get some plywood nail it together and + + + align:start position:0% +get some plywood nail it together and +build a really crummy plywood airplane + + align:start position:0% +build a really crummy plywood airplane + + + align:start position:0% +build a really crummy plywood airplane +and that's what he did so it just shows + + align:start position:0% +and that's what he did so it just shows + + + align:start position:0% +and that's what he did so it just shows +the joy you know you don't have to have + + align:start position:0% +the joy you know you don't have to have + + + align:start position:0% +the joy you know you don't have to have +a high-performance state-of-the-art + + align:start position:0% +a high-performance state-of-the-art + + + align:start position:0% +a high-performance state-of-the-art +airplane if you build it yourself or + + align:start position:0% +airplane if you build it yourself or + + + align:start position:0% +airplane if you build it yourself or +you're goofing around you can have fun + + align:start position:0% +you're goofing around you can have fun + + + align:start position:0% +you're goofing around you can have fun +and he did and he was a better pilot you + + align:start position:0% +and he did and he was a better pilot you + + + align:start position:0% +and he did and he was a better pilot you +know then an alibi B I'm sure you know + + align:start position:0% +know then an alibi B I'm sure you know + + + align:start position:0% +know then an alibi B I'm sure you know +in his p-51 so that that made me think + + align:start position:0% +in his p-51 so that that made me think + + + align:start position:0% +in his p-51 so that that made me think +you know maybe we shouldn't be snobby + + align:start position:0% +you know maybe we shouldn't be snobby + + + align:start position:0% +you know maybe we shouldn't be snobby +about these slim build airplanes because + + align:start position:0% +about these slim build airplanes because + + + align:start position:0% +about these slim build airplanes because +if it was good enough you know po Perez + + align:start position:0% +if it was good enough you know po Perez + + + align:start position:0% +if it was good enough you know po Perez +and you had fun with it all right so + + align:start position:0% +and you had fun with it all right so + + + align:start position:0% +and you had fun with it all right so +here's some examples of homebuilts up at + + align:start position:0% +here's some examples of homebuilts up at + + + align:start position:0% +here's some examples of homebuilts up at +the left there there's some kind of + + align:start position:0% +the left there there's some kind of + + + align:start position:0% +the left there there's some kind of +canard velocity these folks spent 15 + + align:start position:0% +canard velocity these folks spent 15 + + + align:start position:0% +canard velocity these folks spent 15 +years building this helicopter and they + + align:start position:0% +years building this helicopter and they + + + align:start position:0% +years building this helicopter and they +add about 40 hours of flight time on it + + align:start position:0% +add about 40 hours of flight time on it + + + align:start position:0% +add about 40 hours of flight time on it +so it's you know to me you know in a + + align:start position:0% +so it's you know to me you know in a + + + align:start position:0% +so it's you know to me you know in a +good in a good month at a flight school + + align:start position:0% +good in a good month at a flight school + + + align:start position:0% +good in a good month at a flight school +a Robinson helicopter might fly 90 hours + + align:start position:0% +a Robinson helicopter might fly 90 hours + + + align:start position:0% +a Robinson helicopter might fly 90 hours +or 100 hours in just a month so it was + + align:start position:0% +or 100 hours in just a month so it was + + + align:start position:0% +or 100 hours in just a month so it was +taking them you know take them 15 years + + align:start position:0% +taking them you know take them 15 years + + + align:start position:0% +taking them you know take them 15 years +plus to get to where a flight school + + align:start position:0% +plus to get to where a flight school + + + align:start position:0% +plus to get to where a flight school +would get in a month but you know that's + + align:start position:0% +would get in a month but you know that's + + + align:start position:0% +would get in a month but you know that's +kind of not the point it's not about + + align:start position:0% +kind of not the point it's not about + + + align:start position:0% +kind of not the point it's not about +efficiency apparently that's a rotor way + + align:start position:0% +efficiency apparently that's a rotor way + + + align:start position:0% +efficiency apparently that's a rotor way +kid I bet and they modified it by + + align:start position:0% +kid I bet and they modified it by + + + align:start position:0% +kid I bet and they modified it by +sticking in a little tiny turbine engine + + align:start position:0% +sticking in a little tiny turbine engine + + + align:start position:0% +sticking in a little tiny turbine engine +this is another modification this is a + + align:start position:0% +this is another modification this is a + + + align:start position:0% +this is another modification this is a +Rutan design that became the bear coot + + align:start position:0% +Rutan design that became the bear coot + + + align:start position:0% +Rutan design that became the bear coot +with a big piston engine this guy stuck + + align:start position:0% +with a big piston engine this guy stuck + + + align:start position:0% +with a big piston engine this guy stuck +hey a turbojet engine here's the company + + align:start position:0% +hey a turbojet engine here's the company + + + align:start position:0% +hey a turbojet engine here's the company +42,000 I think that doesn't include the + + align:start position:0% +42,000 I think that doesn't include the + + + align:start position:0% +42,000 I think that doesn't include the +engine which is another 50 you can build + + align:start position:0% +engine which is another 50 you can build + + + align:start position:0% +engine which is another 50 you can build +your own little single-seat jet Cirrus + + align:start position:0% +your own little single-seat jet Cirrus + + + align:start position:0% +your own little single-seat jet Cirrus +was there serious actually has been kind + + align:start position:0% +was there serious actually has been kind + + + align:start position:0% +was there serious actually has been kind +of a industry change in company it + + align:start position:0% +of a industry change in company it + + + align:start position:0% +of a industry change in company it +didn't seem that way at the time because + + align:start position:0% +didn't seem that way at the time because + + + align:start position:0% +didn't seem that way at the time because +it's very similar in performance the + + align:start position:0% +it's very similar in performance the + + + align:start position:0% +it's very similar in performance the +Moonies and Piper's and Cessnas but they + + align:start position:0% +Moonies and Piper's and Cessnas but they + + + align:start position:0% +Moonies and Piper's and Cessnas but they +really have revolutionized the way that + + align:start position:0% +really have revolutionized the way that + + + align:start position:0% +really have revolutionized the way that +you know families buy airplanes now and + + align:start position:0% +you know families buy airplanes now and + + + align:start position:0% +you know families buy airplanes now and +they've got over 7,000 of them the + + align:start position:0% +they've got over 7,000 of them the + + + align:start position:0% +they've got over 7,000 of them the +parachute is I think critical to getting + + align:start position:0% +parachute is I think critical to getting + + + align:start position:0% +parachute is I think critical to getting +modern people to accept this design and + + align:start position:0% +modern people to accept this design and + + + align:start position:0% +modern people to accept this design and +also the glass cockpit does make life + + align:start position:0% +also the glass cockpit does make life + + + align:start position:0% +also the glass cockpit does make life +easier although everybody else has + + align:start position:0% +easier although everybody else has + + + align:start position:0% +easier although everybody else has +caught up there here's the icon a5 they + + align:start position:0% +caught up there here's the icon a5 they + + + align:start position:0% +caught up there here's the icon a5 they +had the same booth every year a huge + + align:start position:0% +had the same booth every year a huge + + + align:start position:0% +had the same booth every year a huge +amount of excitement people love it a + + align:start position:0% +amount of excitement people love it a + + + align:start position:0% +amount of excitement people love it a +lot of people have ordered it they + + align:start position:0% +lot of people have ordered it they + + + align:start position:0% +lot of people have ordered it they +haven't figured out how to build it you + + align:start position:0% +haven't figured out how to build it you + + + align:start position:0% +haven't figured out how to build it you +know the price has gotten got to the + + align:start position:0% +know the price has gotten got to the + + + align:start position:0% +know the price has gotten got to the +point where you can almost buy a Cessna + + align:start position:0% +point where you can almost buy a Cessna + + + align:start position:0% +point where you can almost buy a Cessna +Caravan on floats with a jet engine for + + align:start position:0% +Caravan on floats with a jet engine for + + + align:start position:0% +Caravan on floats with a jet engine for +the same price here's a retired airforce + + align:start position:0% +the same price here's a retired airforce + + + align:start position:0% +the same price here's a retired airforce +and Southwest Airlines pilot with his + + align:start position:0% +and Southwest Airlines pilot with his + + + align:start position:0% +and Southwest Airlines pilot with his +electric self launching pipistrelle + + align:start position:0% +electric self launching pipistrelle + + + align:start position:0% +electric self launching pipistrelle +glider the past role is the company to + + align:start position:0% +glider the past role is the company to + + + align:start position:0% +glider the past role is the company to +watch they do a lot of interesting stuff + + align:start position:0% +watch they do a lot of interesting stuff + + + align:start position:0% +watch they do a lot of interesting stuff +in Slovenia + + align:start position:0% +in Slovenia + + + align:start position:0% +in Slovenia +especially with electrics this is not + + align:start position:0% +especially with electrics this is not + + + align:start position:0% +especially with electrics this is not +the kind of radar picture you want to + + align:start position:0% +the kind of radar picture you want to + + + align:start position:0% +the kind of radar picture you want to +see when you're in the $99 tent I will + + align:start position:0% +see when you're in the $99 tent I will + + + align:start position:0% +see when you're in the $99 tent I will +say I will say to Costco that it did + + align:start position:0% +say I will say to Costco that it did + + + align:start position:0% +say I will say to Costco that it did +hold up remarkably well but it was scary + + align:start position:0% +hold up remarkably well but it was scary + + + align:start position:0% +hold up remarkably well but it was scary +the seaplane base a few miles away from + + align:start position:0% +the seaplane base a few miles away from + + + align:start position:0% +the seaplane base a few miles away from +Oshkosh they have the Oshkosh seaplane + + align:start position:0% +Oshkosh they have the Oshkosh seaplane + + + align:start position:0% +Oshkosh they have the Oshkosh seaplane +base + + align:start position:0% +base + + + align:start position:0% +base +I think it's on Lake Winnebago so you + + align:start position:0% +I think it's on Lake Winnebago so you + + + align:start position:0% +I think it's on Lake Winnebago so you +take the shuttle bus or you drive over + + align:start position:0% +take the shuttle bus or you drive over + + + align:start position:0% +take the shuttle bus or you drive over +there if you have a rental car so you'll + + align:start position:0% +there if you have a rental car so you'll + + + align:start position:0% +there if you have a rental car so you'll +see you know they call it the quiet part + + align:start position:0% +see you know they call it the quiet part + + + align:start position:0% +see you know they call it the quiet part +of Akasha it's quiet because you only + + align:start position:0% +of Akasha it's quiet because you only + + + align:start position:0% +of Akasha it's quiet because you only +hear about three or four aircraft + + align:start position:0% +hear about three or four aircraft + + + align:start position:0% +hear about three or four aircraft +engines running at any one time and + + align:start position:0% +engines running at any one time and + + + align:start position:0% +engines running at any one time and +maybe two takeoffs or landings they have + + align:start position:0% +maybe two takeoffs or landings they have + + + align:start position:0% +maybe two takeoffs or landings they have +four hangars vendors if you want to take + + align:start position:0% +four hangars vendors if you want to take + + + align:start position:0% +four hangars vendors if you want to take +your dog and an unpressurized airplane + + align:start position:0% +your dog and an unpressurized airplane + + + align:start position:0% +your dog and an unpressurized airplane +up to 18,000 feet you can buy this kit I + + align:start position:0% +up to 18,000 feet you can buy this kit I + + + align:start position:0% +up to 18,000 feet you can buy this kit I +don't know what our golden retriever + + align:start position:0% +don't know what our golden retriever + + + align:start position:0% +don't know what our golden retriever +would say about that + + align:start position:0% +would say about that + + + align:start position:0% +would say about that +there's affinity groups + + align:start position:0% +there's affinity groups + + + align:start position:0% +there's affinity groups +you know four different slices here's + + align:start position:0% +you know four different slices here's + + + align:start position:0% +you know four different slices here's +one a woman who just like just for + + align:start position:0% +one a woman who just like just for + + + align:start position:0% +one a woman who just like just for +female pilots of Muniz air shows every + + align:start position:0% +female pilots of Muniz air shows every + + + align:start position:0% +female pilots of Muniz air shows every +day + + align:start position:0% +day + + + align:start position:0% +day +my favorite acts actually were I did + + align:start position:0% +my favorite acts actually were I did + + + align:start position:0% +my favorite acts actually were I did +like the game bird that was cool but I + + align:start position:0% +like the game bird that was cool but I + + + align:start position:0% +like the game bird that was cool but I +also liked this first two were kind of + + align:start position:0% +also liked this first two were kind of + + + align:start position:0% +also liked this first two were kind of +regular family airplanes just being + + align:start position:0% +regular family airplanes just being + + + align:start position:0% +regular family airplanes just being +pushed to their limits it wouldn't be + + align:start position:0% +pushed to their limits it wouldn't be + + + align:start position:0% +pushed to their limits it wouldn't be +legal just to go out and do that in a + + align:start position:0% +legal just to go out and do that in a + + + align:start position:0% +legal just to go out and do that in a +barren because you can't do acrobatics + + align:start position:0% +barren because you can't do acrobatics + + + align:start position:0% +barren because you can't do acrobatics +but he would help put it into + + align:start position:0% +but he would help put it into + + + align:start position:0% +but he would help put it into +experimental category and then just fly + + align:start position:0% +experimental category and then just fly + + + align:start position:0% +experimental category and then just fly +it right up to the G limits for which it + + align:start position:0% +it right up to the G limits for which it + + + align:start position:0% +it right up to the G limits for which it +was designed and it's amazing to see + + align:start position:0% +was designed and it's amazing to see + + + align:start position:0% +was designed and it's amazing to see +what these you know ordinary family or + + align:start position:0% +what these you know ordinary family or + + + align:start position:0% +what these you know ordinary family or +business airplanes can do when pushed + + align:start position:0% +business airplanes can do when pushed + + + align:start position:0% +business airplanes can do when pushed +there were one thing is interesting + + align:start position:0% +there were one thing is interesting + + + align:start position:0% +there were one thing is interesting +about 150 Beechcraft aerobatic bonanzas + + align:start position:0% +about 150 Beechcraft aerobatic bonanzas + + + align:start position:0% +about 150 Beechcraft aerobatic bonanzas +were built they were strengthened and it + + align:start position:0% +were built they were strengthened and it + + + align:start position:0% +were built they were strengthened and it +is legal to do aerobatics in your four + + align:start position:0% +is legal to do aerobatics in your four + + + align:start position:0% +is legal to do aerobatics in your four +seed Bonanza night airshow I guess + + align:start position:0% +seed Bonanza night airshow I guess + + + align:start position:0% +seed Bonanza night airshow I guess +that's worth showing it is so unusual + + align:start position:0% +that's worth showing it is so unusual + + + align:start position:0% +that's worth showing it is so unusual +they had explosives and fireworks + + align:start position:0% +they had explosives and fireworks + + + align:start position:0% +they had explosives and fireworks +mounted on the aircraft so they fly + + align:start position:0% +mounted on the aircraft so they fly + + + align:start position:0% +mounted on the aircraft so they fly +around at night shooting fireworks off I + + align:start position:0% +around at night shooting fireworks off I + + + align:start position:0% +around at night shooting fireworks off I +guess you may have to you may have to + + align:start position:0% +guess you may have to you may have to + + + align:start position:0% +guess you may have to you may have to +view that on your own which isn't so bad + + align:start position:0% +view that on your own which isn't so bad + + + align:start position:0% +view that on your own which isn't so bad +a lot of warbirds everything from World + + align:start position:0% +a lot of warbirds everything from World + + + align:start position:0% +a lot of warbirds everything from World +War two is still flying pretty much at + + align:start position:0% +War two is still flying pretty much at + + + align:start position:0% +War two is still flying pretty much at +Oshkosh that Grumman tiger cat on the + + align:start position:0% +Oshkosh that Grumman tiger cat on the + + + align:start position:0% +Oshkosh that Grumman tiger cat on the +right I'd never even heard of that + + align:start position:0% +right I'd never even heard of that + + + align:start position:0% +right I'd never even heard of that +airplane until I saw it at Oshkosh + + align:start position:0% + + + + align:start position:0% + +that's I think this is EA's own b-17 + + align:start position:0% +that's I think this is EA's own b-17 + + + align:start position:0% +that's I think this is EA's own b-17 +which they fly around and sell rides and + + align:start position:0% +which they fly around and sell rides and + + + align:start position:0% +which they fly around and sell rides and +and stuff + + align:start position:0% +and stuff + + + align:start position:0% +and stuff +oh and up on the top right is a flying + + align:start position:0% +oh and up on the top right is a flying + + + align:start position:0% +oh and up on the top right is a flying +1/3 scale b-17 that some crazy guy spent + + align:start position:0% +1/3 scale b-17 that some crazy guy spent + + + align:start position:0% +1/3 scale b-17 that some crazy guy spent +15 years building or more + + align:start position:0% +15 years building or more + + + align:start position:0% +15 years building or more +that's EAA also they have a b-29 up + + align:start position:0% +that's EAA also they have a b-29 up + + + align:start position:0% +that's EAA also they have a b-29 up +there the top right is my friend Erik + + align:start position:0% +there the top right is my friend Erik + + + align:start position:0% +there the top right is my friend Erik +with his personal I guess he hasn't + + align:start position:0% +with his personal I guess he hasn't + + + align:start position:0% +with his personal I guess he hasn't +found a ssin with a few other people but + + align:start position:0% +found a ssin with a few other people but + + + align:start position:0% +found a ssin with a few other people but +he's essentially a personal dc-3 oh and + + align:start position:0% +he's essentially a personal dc-3 oh and + + + align:start position:0% +he's essentially a personal dc-3 oh and +he's flying up to Europe this year for + + align:start position:0% +he's flying up to Europe this year for + + + align:start position:0% +he's flying up to Europe this year for +the 50th anniversary of d-day is it the + + align:start position:0% +the 50th anniversary of d-day is it the + + + align:start position:0% +the 50th anniversary of d-day is it the +50th no it can't be + + align:start position:0% +50th no it can't be + + + align:start position:0% +50th no it can't be +what seventy-fifth sorry thank you I was + + align:start position:0% +what seventy-fifth sorry thank you I was + + + align:start position:0% +what seventy-fifth sorry thank you I was +in math undergrad good illustration of + + align:start position:0% +in math undergrad good illustration of + + + align:start position:0% +in math undergrad good illustration of +the value of a course 18 degree and + + align:start position:0% +the value of a course 18 degree and + + + align:start position:0% +the value of a course 18 degree and +actually when I was in undergrad people + + align:start position:0% +actually when I was in undergrad people + + + align:start position:0% +actually when I was in undergrad people +said how will you ever get a job if + + align:start position:0% +said how will you ever get a job if + + + align:start position:0% +said how will you ever get a job if +you're a math major the engineers all + + align:start position:0% +you're a math major the engineers all + + + align:start position:0% +you're a math major the engineers all +said that when you said well we can + + align:start position:0% +said that when you said well we can + + + align:start position:0% +said that when you said well we can +become actuaries we can become actuaries + + align:start position:0% +become actuaries we can become actuaries + + + align:start position:0% +become actuaries we can become actuaries +if there's a group of folks who are + + align:start position:0% +if there's a group of folks who are + + + align:start position:0% +if there's a group of folks who are +passionate about warbirds down in the + + align:start position:0% +passionate about warbirds down in the + + + align:start position:0% +passionate about warbirds down in the +south and they called their organization + + align:start position:0% +south and they called their organization + + + align:start position:0% +south and they called their organization +the Confederate air Confederate Air + + align:start position:0% +the Confederate air Confederate Air + + + align:start position:0% +the Confederate air Confederate Air +Force well they've had to change that + + align:start position:0% +Force well they've had to change that + + + align:start position:0% +Force well they've had to change that +now they're the commemorative Air Force + + align:start position:0% +now they're the commemorative Air Force + + + align:start position:0% +now they're the commemorative Air Force +and they're big into they brought the + + align:start position:0% +and they're big into they brought the + + + align:start position:0% +and they're big into they brought the +Tuskeegee Airmen some of the remaining + + align:start position:0% +Tuskeegee Airmen some of the remaining + + + align:start position:0% +Tuskeegee Airmen some of the remaining +p-51 guys from World War two there I + + align:start position:0% +p-51 guys from World War two there I + + + align:start position:0% +p-51 guys from World War two there I +gave a talk with Noah that's Kate from + + align:start position:0% +gave a talk with Noah that's Kate from + + + align:start position:0% +gave a talk with Noah that's Kate from +NOAA trying to get volunteer pilots to + + align:start position:0% +NOAA trying to get volunteer pilots to + + + align:start position:0% +NOAA trying to get volunteer pilots to +fly sea turtles back from Cape Cod and + + align:start position:0% +fly sea turtles back from Cape Cod and + + + align:start position:0% +fly sea turtles back from Cape Cod and +other northern places to Florida Sunday + + align:start position:0% +other northern places to Florida Sunday + + + align:start position:0% +other northern places to Florida Sunday +morning it was time to leave I for me I + + align:start position:0% +morning it was time to leave I for me I + + + align:start position:0% +morning it was time to leave I for me I +saw a 30% of what we'd hope to see and + + align:start position:0% +saw a 30% of what we'd hope to see and + + + align:start position:0% +saw a 30% of what we'd hope to see and +1% of what there was to see as you can + + align:start position:0% +1% of what there was to see as you can + + + align:start position:0% +1% of what there was to see as you can +see from the right that one week wonder + + align:start position:0% +see from the right that one week wonder + + + align:start position:0% +see from the right that one week wonder +is coming together it actually did fly I + + align:start position:0% +is coming together it actually did fly I + + + align:start position:0% +is coming together it actually did fly I +believe on Sunday so they they got it + + align:start position:0% +believe on Sunday so they they got it + + + align:start position:0% +believe on Sunday so they they got it +built in seven or eight days we went to + + align:start position:0% +built in seven or eight days we went to + + + align:start position:0% +built in seven or eight days we went to +Mackinac Island beautiful place up near + + align:start position:0% +Mackinac Island beautiful place up near + + + align:start position:0% +Mackinac Island beautiful place up near +the Canadian border + + align:start position:0% +the Canadian border + + + align:start position:0% +the Canadian border +everything is horse-drawn or bicycle fun + + align:start position:0% +everything is horse-drawn or bicycle fun + + + align:start position:0% +everything is horse-drawn or bicycle fun +place to go in the airplane we went we + + align:start position:0% +place to go in the airplane we went we + + + align:start position:0% +place to go in the airplane we went we +went and landed to Toronto City Island + + align:start position:0% +went and landed to Toronto City Island + + + align:start position:0% +went and landed to Toronto City Island +Airport which is right in front of + + align:start position:0% +Airport which is right in front of + + + align:start position:0% +Airport which is right in front of +downtown we had Chinese food + + align:start position:0% +downtown we had Chinese food + + + align:start position:0% +downtown we had Chinese food +so the aquarium landed back in Bedford + + align:start position:0% +so the aquarium landed back in Bedford + + + align:start position:0% +so the aquarium landed back in Bedford +so we burned up 15 hours of Hobbes time + + align:start position:0% +so we burned up 15 hours of Hobbes time + + + align:start position:0% +so we burned up 15 hours of Hobbes time +split by three people that wouldn't be + + align:start position:0% +split by three people that wouldn't be + + + align:start position:0% +split by three people that wouldn't be +too horrible it was about three thousand + + align:start position:0% +too horrible it was about three thousand + + + align:start position:0% +too horrible it was about three thousand +dollars at retail next year I think it + + align:start position:0% +dollars at retail next year I think it + + + align:start position:0% +dollars at retail next year I think it +might be time to go JetBlue so the + + align:start position:0% +might be time to go JetBlue so the + + + align:start position:0% +might be time to go JetBlue so the +summary is that you know even as the + + align:start position:0% +summary is that you know even as the + + + align:start position:0% +summary is that you know even as the +regulation has made light aircraft + + align:start position:0% +regulation has made light aircraft + + + align:start position:0% +regulation has made light aircraft +almost as expensive to operate + + align:start position:0% +almost as expensive to operate + + + align:start position:0% +almost as expensive to operate +commercially at least or for charter has + + align:start position:0% +commercially at least or for charter has + + + align:start position:0% +commercially at least or for charter has +the big aircraft so but Oshkosh keeps + + align:start position:0% +the big aircraft so but Oshkosh keeps + + + align:start position:0% +the big aircraft so but Oshkosh keeps +growing every year more people are + + align:start position:0% +growing every year more people are + + + align:start position:0% +growing every year more people are +passionate about it so what you're + + align:start position:0% +passionate about it so what you're + + + align:start position:0% +passionate about it so what you're +seeing in the aircraft world is like the + + align:start position:0% +seeing in the aircraft world is like the + + + align:start position:0% +seeing in the aircraft world is like the +very high-end and the very low end or + + align:start position:0% +very high-end and the very low end or + + + align:start position:0% +very high-end and the very low end or +kind of prospering + + align:start position:0% +kind of prospering + + + align:start position:0% +kind of prospering +this is Oksana Stang she asked everybody + + align:start position:0% +this is Oksana Stang she asked everybody + + + align:start position:0% +this is Oksana Stang she asked everybody +like what brings you to ash cops and + + align:start position:0% +like what brings you to ash cops and + + + align:start position:0% +like what brings you to ash cops and +they always said the people I love + + align:start position:0% +they always said the people I love + + + align:start position:0% +they always said the people I love +talking to the people here and I feel + + align:start position:0% +talking to the people here and I feel + + + align:start position:0% +talking to the people here and I feel +that way too people go you know year + + align:start position:0% +that way too people go you know year + + + align:start position:0% +that way too people go you know year +after year there's a whole bunch of + + align:start position:0% +after year there's a whole bunch of + + + align:start position:0% +after year there's a whole bunch of +Link's here in the presentation and + + align:start position:0% +Link's here in the presentation and + + + align:start position:0% +Link's here in the presentation and +finally you know what I like most about + + align:start position:0% +finally you know what I like most about + + + align:start position:0% +finally you know what I like most about +it is and the reason I'm going back I + + align:start position:0% +it is and the reason I'm going back I + + + align:start position:0% +it is and the reason I'm going back I +think is it's it's my safe space outside + + align:start position:0% +think is it's it's my safe space outside + + + align:start position:0% +think is it's it's my safe space outside +of this room if I tell people you know I + + align:start position:0% +of this room if I tell people you know I + + + align:start position:0% +of this room if I tell people you know I +have to go over to Hanscom field and buy + + align:start position:0% +have to go over to Hanscom field and buy + + + align:start position:0% +have to go over to Hanscom field and buy +this little four seat airplane with a + + align:start position:0% +this little four seat airplane with a + + + align:start position:0% +this little four seat airplane with a +piston engine they're horrified that's + + align:start position:0% +piston engine they're horrified that's + + + align:start position:0% +piston engine they're horrified that's +just so dumb you could just drive to New + + align:start position:0% +just so dumb you could just drive to New + + + align:start position:0% +just so dumb you could just drive to New +York in your Honda you could get a + + align:start position:0% +York in your Honda you could get a + + + align:start position:0% +York in your Honda you could get a +ticket on JetBlue for no money like why + + align:start position:0% +ticket on JetBlue for no money like why + + + align:start position:0% +ticket on JetBlue for no money like why +would you do that it's dumb but Oshkosh + + align:start position:0% +would you do that it's dumb but Oshkosh + + + align:start position:0% +would you do that it's dumb but Oshkosh +is the one place where nobody will say + + align:start position:0% +is the one place where nobody will say + + + align:start position:0% +is the one place where nobody will say +that + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/srjNMMtPATo.txt b/srjNMMtPATo.txt new file mode 100644 index 0000000000000000000000000000000000000000..453995513c544c4e6dd5c31f3952fd35341186b0 --- /dev/null +++ b/srjNMMtPATo.txt @@ -0,0 +1,1823 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Alright. + +Well, we've been looking in the +last couple lectures at a + +really important topic +in thermodynamics. + +Which is, how do you tell +what's going to happen. + +Which way does a process +want to go? + +Which way will it go +spontaneously? + +And if it goes in one direction +or another, where + +does is lead? + +In other words, what is +the equilibrium state? + +And this is just an incredibly +important area that + +thermodynamics allows +us to speak to. + +So we started to see this. + +Sort of direction of +spontaneous change. + +And where the equilibrium +lies. + +So what we did is, remember we +started with the second law. + +Right? + +That dS is greater than +dq over T. And for the + +spontaneous change which happens +irreversibly That + +means that'll be dq +irreversible. + +It would be equal for +the reversible case. + +And we combine this with first +law, which for the case of + +pressure volume changes +we write as this. + +And so what this gave us was +a very, very useful general + +criterion for determining +whether something happened + +spontaneously. + +Namely, du plus p external dV +minus T for the surroundings + +dS, is greater than zero. + +Sorry. + +It's less than zero. + +And this is for any spontaneous +change. + +If it equals zero, then +we're at equilibrium. + +And if it's greater than +zero, then the process + +goes the other way. + +We would write the process in +the reverse to have it be less + +than 0 and it would +go spontaneously. + +And based on this one result, +we then looked under various + +constraints and said OK, what +about looking at our + +variables, volume, pressure, +temperature, other things, + +entropy, if we constrain those, +what's the condition + +for equilibrium? + +And that's what led us to a +number of results to determine + +what quantities we even +need to be looking at. + +To figure out equilibrium. + +And what the conditions were. + +And so what we discovered +were the following. + +This one, which we already +had seen, which is dS, is + +greater than zero. + +Change in entropy is +greater than zero, + +for an isolated system. + +We also saw that dS for constant +H and p was greater + +than zero. du, regular energy, +at constant entropy and volume + +is less then zero. + +And u is minimized +at equilibrium. + +And this is the familiar +result from ordinary + +mechanics, where you're not +worrying about something like + +entropy for a whole collection +of particles. + +That is, you minimize potential +energy and you see + +things falling under the force +of gravity and so forth, going + +to potential energy minima in +conformance with this result. + +dH, S and p is less than zero. + +So our H is u plus +pV, as you know. + +And H is minimized +at equilibrium. + +And this is, of course, with +constant S V. This is + +constant S and p. + +But of course, the need to have +entropy constrained is + +never going to be the most +convenient one experimental. + +There may be circumstances under +which it's the case, but + +it's often difficult +to control. + +On the other hand, temperature, +volume and + +pressure are variables that are +much easier in the lab to + +keep constant. + +To keep control over. + +And so that led us to the +definitions of other energy + +quantities, the Helmholtz +and Gibbs free energy. + +We discovered that the quantity +dA, under conditions + +of constant volume +and temperature, + +is less than zero. + +And A is u minus TS. + +And A is minimized at +equilibrium, under conditions + +of constant T and V. And +finally, and in many cases the + +most important of the results, +because of the conditions it + +applies to, we saw that this +Gibbs free energy is less than + +zero, that's our condition +for spontaneous change. + +Where the Gibbs free energy, +u plus pV minus + +TS is H minus TS. + +Also A plus pV and G is +minimized at equilibrium with + +constant temperature +and pressure. + +And that's why the Gibbs +free energy is just + +so enormously important. + +Because so much of what we do +in chemistry does take place + +with constant temperature +and pressure. + +So we have this condition +that's established in a + +quantity that we know +how to calculate. + +That tells us the direction +of spontaneous change for + +ordinary processes, chemical +processes, mixing and you name + +it, under conditions that are +easy to achieve in the lab. + +OK, now what we'd like to do is +be able to calculate any of + +these quantities in terms of +temperature, pressure, volume + +properties. + +That is, in terms of +equations of state. + +For any material. + +Then we would really be able to + +essentially calculate anything. + +Anything thermodynamic. + +About a material. + +Of course, that's assuming we +know the equation of state. + +We may or may not. + +But because in many cases we can +reasonably either model or + +measure equations of state, +collect data for a material + +for its temperature, pressure, +volume relations, then in fact + +if we can relate all these +quantities to those, then in + +fact we really can calculate +essentially all of the + +thermodynamics. + +For the material. + +So let's relate the +thermodynamic quantities to + +equation of state +p, V, T data. + +And we can do that by going +through and deriving what + +we'll call the fundamental +equations of thermodynamics. + +that'll provide these +relations. + +And at this point we know +enough to do this in a + +straightforward way. + +So if we start with a relation +for energy, T dS minus p dV. + +Where u is written +as a function + +of entropy and volume. + +And we've seen that that's +generally the case. + +It comes from the fact that dq +reversible is T dS, and dw + +reversible is minus p dV. + +And of course du is +the some of those. + +So, this is generally true. + +Since these are all +state functions. + +That is, this is derived in the +case for reversible paths. + +But since these are all simply +state functions and + +quantities, this is +generally true. + +Now we can use it to derive +differential relations for all + +of the thermodynamics +quantities. + +So let's just go through +and do that. + +So H is u plus pV. + +So dH is just du plus +p dV plus V dp. + +And now we're just going to +substitute du in here. + +And the p dV terms are +going to cancel. + +So we have the result that +dH is T dS plus V dp. + +Right? + +And that shows us that H is +written naturally as a + +function of entropy +and pressure. + +And now let's keep going. + +A is u minus TS. + +dA is du minus T +dS minus S dT. + +We're going to do +the same thing. + +Substitute this for du. + +This time, the T dS terms +are going to cancel. + +So we have dA is minus +S dT minus T dS. + +That can't be right. + +And it isn't. + +Minus S dT, that's the p dV term +that's left, minus p dV. + +And it shows us that A is +written naturally as a + +function of T and V. G, +we can write in any + +of a number of ways. + +Let's write it as H minus TS. + +So dG is dH minus +T dS minus S dT. + +Here's dH. + +We'll substitute that in, +and the T dS terms + +are going to cancel. + +So dG is minus S dT plus V dp. + +And this shows that G is +written naturally as a + +function of T and p. + +So these, which we will exalt +and celebrate by our + +sparingly-used colored chalk, +are our fundamental equations + +of thermodynamics. + +So what they do is, they're +describing how these + +thermodynamic properties change, +in terms of only state + +functions and state variables. + +Very, very useful. + +And that's what it means, when +we say well, it's natural + +then, to express say, G as a +function of T and p, that's + +what we're saying. + +Is that we can express +its changes in + +terms of these variables. + +Related only through +quantities that are + +functions of state. + +I don't need to know about +a specific path here. + +If I know about the states +involved, I just need to know + +what the volume was +in each of them. + +Now, before, of course, in the +first part of the class we + +started out looking at u and +then looking at H not as + +functions of S and V or S and +p, but as functions of + +temperature, mostly. + +In general, temperature and +volume or pressure. + +And it doesn't mean +that something was + +somehow wrong with that. + +It certainly is, it still is +going to be useful to do + +thermochemistry. + +To ask questions like how much +heat is released in a chemical + +reaction that takes place +at constant temperature. + +Not one of these variables. + +And we can calculate that. + +So it's not that we're somehow +throwing away our + +ability to do that. + +However, the thing to remember +is, when you look at heats of + +reaction under those +conditions it's + +all well and good. + +But it doesn't tell you, this +is the direction that the + +reaction is going to go. + +It doesn't tell you, this is the +equilibrium concentration + +that you'll end up with. + +That doesn't come out of what +we calculated before in + +thermochemistry. + +What does come out, which is +very useful is, if you do run + +the reaction, here's how +much heat comes out. + +And if you want to run a furnace +and provide energy, + +that's an extremely important +thing to be able to calculate. + +Because you're going to run it +and you'll probably find + +conditions under which you can +run it more or less to + +completion. + +But it doesn't tell you, +by itself, which + +direction things run in. + +Whereas under these conditions, +these quantities, + +if you look at free energy +change, for example, at + +constant temperature and +pressure, you can still + +calculate H. You can +still calculate + +the heat that's released. + +This is what will tell you +under some particular + +conditions what will +actually happen. + +Where will you end up. + +Very, very important, of +course, to be able to + +understand that. + +Now, it's also very useful to +look at some of the relations + +that come out of these +fundamental equations. + +And they're straightforward +to derive. + +So, all I want to do now is look +at the derivatives of the + +free energies with respect +to temperature + +and volume and pressure. + +So for example, if I look at A, +which we now have written + +as the function of T and V, of +course, in general I can + +always write dA as partial of +A, with respect to T at + +constant volume dT, plus partial +of A with respect to + +V, at constant temperature dV. + +And I know what those +turn out to be. + +It's minus S dT minus p dV. + +So what does that tell me? + +It tells me that the partial +of A with respect to T at + +constant V is minus S. Right? + +In other words, now I know how +to tell how the Helmholtz free + +energy changes as a function +of temperature. + +Or as a function of volume. +dA/dV, at constant T, must be + +negative p. + +Things that I can measure. + +So I can in a very +straightforward way say, OK, + +well, here is my Helmholtz +free energy. + +If I'm working under conditions +of constant + +temperature and volume, +that's very useful. + +Now, if I want to change those +quantities; change the + +temperature, change the volume, +how will it change? + +Well, I can, for any given case, +measure the pressure, + +determine the entropy and +I'll know what the slope + +of change will be. + +Similarly for G as a function of +temperature and pressure, I + +can go through the +same procedure. + +That is, it's easy to write down +straight away that dG, + +with respect to temperature at +constant pressure is minus S. + +That is, this is, dG/dT +at constant pressure. + +And this is dG/dp at constant +temperature. + +So again with the Gibbs free +energy, now I see how to + +determine, if I change the +pressure, if I change the + +temperature by some modest +amount, how much is the Gibbs + +free energy going to change? + +Well, it's easy to see. + +These two relations involving +entropy are also useful + +because they'll let us see +how entropy depends + +on volume and pressure. + +And let me show you +how that goes. + +Now, you've already seen +how entropy depends on + +temperature. + +We've already seen that, going +to write dS as dq reversible + +over T. And it's Cv dT over +T at constant volume. + +It's Cp dT over T at +constant pressure. + +So we know that dS/dT at +constant volume is Cv over T, + +and dS/dT at constant pressure +is Cp, over T. And we've seen + +that on a number of occasions. + +So that tells us what to do +to know the entropy as the + +temperature changes. + +But now, what happens if, +instead we look at what + +happens when we go to some state +one to some other state + +two and it's the pressure. + +Or the volume, that changes. + +And by the way, just to be +explicit about this, let's + +take this example, it means that +delta S, if we undergo a + +change from, say, T1 to T2. + +There's Cp over T dT. + +So it's Cp log of T2 over T1, +and we saw this before. + +So now, instead, let's +look at some process. + +State one goes to state two. + +Let's have constant T. And +look at what happens if + +pressure goes from p1 to p2. + +Or volume goes from V1 to V2. + +And see what happens there. + +We looked at pressure change +before, actually, in + +discussing the third law, the +fact that the entropy goes to + +zero as the absolute temperature +goes to zero for a + +pure, perfect crystal. + +But, actually, we didn't do +that in a general way. + +We just treated the one case +of an ideal gas as the + +temperature is reduced. + +But we can do this, generally, +by using what are called + +Maxwell relations. + +And all this is, is saying that +when you take a mixed + +second derivative, it doesn't +matter in which order you take + +the two derivatives. + +So, let's, we're going to +use this relationship. + +And we're going to +use these two. + +So, using those, now, what +happens if we take the second + +derivative of A, the mixed +derivative, partial with + +respect to T and the partial +with respect to V. So let's + +leave these off for a moment, +and now let's try that. + +And the point is that the second +derivative of A, with + +respect to V and T in this +order is the same as the + +second derivative of +a with respect to T + +and V in this order. + +It doesn't matter which order. + +But that turns out +to be useful. + +So let's do this explicitly. + +Which means we're going to +take the derivative with + +respect to volume of dA/dT. + +Now, the dA/dT isn't +constant volume. + +The derivative we're taking with +respect to volume, when + +we take that it's at constant +temperature. + +But what is it? + +Well, we already know what +dA/dT at constant V is. + +It's negative S. So this +is negative dS/dV. + +At constant temperature. + +Now let's take it in +the other order. + +So d/dT of dA/dV, +just like this. + +The dA/dV is calculated at +constant temperature. + +We know it. + +Then we can take the derivative +of that quantity, + +when we vary the temperature, +holding the volume constant. + +But again, dA/dV dT, +there it is. + +It's negative p. + +So this is just negative dp/dT +at constant volume. + +These things have to be +equal to each other. + +Because these mixed +second derivatives + +are the same thing. + +But that's very useful. + +Because this is what comes +directly out of an equation of + +state, right? + +You know how pressure changes +with temperature at constant + +volume if you know the +equation of state. + +It relates the pressure, +volume, + +and temperature together. + +So from measured equation of +state data, or from a model + +like the ideal gas or the van +der Waal's gas or another + +equation of state, +you know this. + +Can determine how entropy +is going to behave + +as the volume changes. + +If we try that for an ideal +gas, pV is nRT. + +So dp/dT at constant volume, +it's just nR over V. And that, + +now, we know must equal dS/dV, +with a positive sign. + +At constant temperature. + +So now let's try looking +at something where + +are V1 goes to V2. + +The volume is going to change, +and we can see + +how the entropy changes. + +So, if one goes to two and V1 +goes to V2, and it's constant + +temperature, just what we've +specified there. + +Delta S is S(T, V2) minus S(T, +V1), T's staying the same. + +So it's just the integral from +V1 to V2 of dS/dV At constant + +temperature dV. + +And now we know what that is. + +So it's nR integral from V1 to +V2 dV over V. So it's nR log + +V2 over V1. + +There's our delta S. So we +know how to calculate it. + +Make sense? + +Now, we can do the same +procedure for + +the pressure change. + +And all we do is, I'll just +outline this, I think. + +I won't write it all +on the board. + +But, of course, it's going to +come from the fact that these + +second derivatives +are also equal. + +So d squared G dT dp is equal +to d squared G dp dT. + +In other words, the order of +taking the derivatives with + +respect to pressure and +temperature doesn't matter. + +And what this will show is +that dS/dp at constant + +temperature, here we saw how +entropy varies with volume, + +this is going to show us how +it varies with pressure. + +Is equal to minus dV/dT +at constant pressure. + +And again, this is something +that comes from + +an equation of state. + +We know how the volume and +temperature vary with respect + +to each other at constant +pressure. + +That's what the equation +of state tells us. + +So, again, I can just +use that result. + +So, if we do a process where +one goes to two at constant + +temperature, and now the +pressure, p1, goes to p2, well + +then delta S is just the +integral from p1 to p2 of + +dS/dp times dS, so +it's just this. + +And so of course it's +still pV equals nRT. + +So now we just have +nR over p dp. + +Right? + +So we're going to see +the same story. + +It's nR log of p2 over p1 for +the process where there's a + +pressure change. + +Any questions about this part? + +So what we've done is take +one step further. + +We've used the fundamental +equations that are hiding down + +here, out of sight but +never out of mind. + +And what we've done is look at +the derivatives of the new + +free energies that we've just +recently introduced, A and G. + +And then, the only thing we've +done beyond that is say, OK, + +well now let's just take the +mixed second derivatives, they + +have to be equal +to each other. + +And what's fallen out when we do +that, because in each case, + +one of the first derivatives +gives us the entropy. + +Then the second derivative gives +the change in entropy + +with respect to the variable +that we're differentiating, + +with respect to which is either +pressure or volume. + +And the useful outcome of all +that is that we get to see how + +entropy changes with one of +those variables in terms of + +only V, T, and p, which come out +of some equation of state. + +And all we did, further, is take +that second derivative. + +That mixed second derivative. + +And, of course, see that either +way we do that we'll + +have an equality. + +Now, let's go back to our older +friends u and H. Which + +we've expressed now in terms +of S and V, S and p. + +So, so far we don't have a way +to just write off, relate them + +to equation of state data. + +Which also would +be very useful. + +Here, A and G, we've already +got as functions of these + +easily controlled, conveniently + +controlled state variables. + +Let's look at those quantities. +u and H. And look + +at, for example, the +V dependence of u. + +The volume dependence. + +And in particular let's look +at, for example, du/dV at + +constant temperature. + +Now, we can immediately +see what du/dV at + +constant entropy is. + +Experimentally, though, that's +not such an easy + +situation to arrange. + +Of course, this is a much +more practical one. + +But it doesn't just fall out +immediately from the one + +fundamental equation for du. + +But we can start there. + +So, du is T dS minus p dV. + +And I can take this derivative. +du/dV at constant + +T. And so, what is it? + +Well, it's not just p because +there's some dS/dV at constant + +T. This isn't zero. + +There's some variation, dS/dV, +at constant temperature. + +That's going to matter. + +This part, of course, +is just minus p. + +But we just figured out what +dS/dV at constant T is. + +This is dp/dT at constant +V. So that's neat. + +So in other words, we can write +this as T, dp/dT at + +constant V, minus p. + +Let's just check T, p, T, V, p. + +Right? + +In other words, we just +have pressure, + +temperature and volume. + +Again, if we know the equation +of state, we + +know all this stuff. + +So again, we can measure +equation of state data. + +Or, if we know the equation of +state from a model, ideal gas, + +van der Waal's gas, whatever, +now we can determine u. + +From equation of state data. + +Terrific, right? + +So let's take our one model that +we keep going back to. + +Equation of state, and just +see how it works. + +That is, ideal gas. + +And see how it works +with that. + +Now, we saw before, or really +I should say we accepted + +before, that for an ideal +gas, u was a function of + +temperature only. + +Well, now let's try it. + +So, dp/dT, for our ideal gas, +at constant volume, + +remember pV is nRT. + +So this nR over V. And then, +using the relation again, we + +can just write this as p over +T. In other words, we're + +taking advantage of +the fact that we + +now know that quantity. + +In the case of the ideal +gas, we just have a + +simple model for it. + +More generally, we +could measure it. + +We could just collect +a bunch of data. + +For a material. + +What's the volume it occupies +at some pressure and + +temperature? + +Now let's change the pressure +and temperature and sweep + +through a whole range of +pressures and temperatures and + +measure the volume in +every one of them. + +Well, then, we could +just use that for + +our equation of state. + +One way or another, we can +determine this quantity. + +For the ideal gas it's this. + +So now our du/dV, at constant T +is just T times dp/dT, which + +is just p over T minus +p, it's zero. + +Remember the Joule expansion. + +And we saw that, you saw that +the Joule coefficient for an + +ideal gas was zero. + +So that you could see that for +the ideal gas, u would not be + +a function of volume, but +only of temperature. + +But actually, when you saw that +before, you weren't given + +any proof of that. + +It was just that when the +good Mr. Joule made the + +measurements, to the precision +that he could measure, he + +discovered that for some gases +it was extremely small. + +At least, smaller than anything +he could detect. + +So it sure seemed like it was +going to zero, under ideal gas + +conditions. + +And that was the result that +we came to accept. + +Here, though, you can just +derive straight away. + +That for an ideal gas it has to +be the case that there's no + +volume dependence +of the energy. + +Only a temperature dependence. + +It's the same for H. Just like +u, we'd like to be able to + +express it in a way that allows +us to calculate what + +happens only from equation +of state data. + +But, again, our fundamental +equations show us how it + +changes as a function of +entropy and pressure. + +So, dH is T dS plus V dp. + +So let's look at dH/dp. + +We know how to get it +immediately if we + +keep entropy constant. + +But we'd like to relate it to +what happens if we keep the + +temperature constant. + +So then, just like we saw, +analogous to what saw just + +before, it's T dS/dp at constant +T. Plus V. But now + +we've seen from the Maxwell +relations that dS/dp is minus + +dV/dT, for constant p. + +Again, this is this quantity, +one of these quantities that + +again we can determine from +equation of state data. + +Only V, p and T appear. + +So it's minus T dV/dT at +constant p, plus V. And so, + +again, this can come from +equation of state data. + +And if you do this again for +an ideal gas, let me see. + +So we have pV is nRT. + +So dV/dT at constant pressure +is just nR over p. + +But we can plug that in again +just like we did before. + +It's just equal to V over T. +And so dH/dp under our + +condition of constant +temperature is just minus T + +times V over T plus +V, everything + +cancels, and that's zero. + +That's our Joule - Thompson +expansion. + +That was a constant +enthalpy change. + +And again there, too, you saw +an experimental result you + +were presented with that says, +well at least to the extent + +that it could be measured, +it was obviously + +getting very small. + +For gases that approach +ideal gas conditions. + +Well, there you can see it. + +Sure better have gotten +small because in fact + +it has to be zero. + +Now let's take just +one somewhat + +more complicated case. + +Let's look at a van +der Waal's gas. + +Let's try it with a different +equation of state, that isn't + +quite as simple as the +ideal gas case. + +So, then p plus a over molar +volume squared times V minus b + +molar volume V minus b is +equal to RT, remember? + +This was back from the +first or second + +lecture in the course. + +So, we can separate out p. + +It's RT over molar volume minus +b minus a over molar + +volume V squared. + +And then we can take the +derivative with respect to + +temperature, it's just R over +molar volume minus b. + +So it's dp/dT at constant V is +just R over V bar minus b. + +Well, let's now look, given +this, let's now look in that + +case, at what happens to u as a +function of V. For the ideal + +gas, we know that u is +volume independent. + +It only depends on +the temperature. + +But for the van der +Waal's gas, now + +it's going to be different. + +And that's because this is +different from what it is in + +the ideal gas case. + +Namely, now du/dV at constant T, +for the van der Waal's gas. + +So it's this. + +So it's RT over molar +volume minus b. + +Minus p, right? + +But in fact, if you go back to +the van der Waal's equation of + +state, here's RT +over v minus b. + +If we put it as minus +b, that's just + +equal to a over V squared. + +Equals a over molar +volume squared. + +But the point is, the main +point is, it's not zero. + +It's some number. a over the +molar volume squared. a is a + +positive number in the van der +Waal's equation of state. + +So this is greater than zero. + +In other words, u is a function +of T and V. If we + +don't have an ideal gas. + +By the way, just to think about +it a little bit, it's a + +positive number. + +What that means is, I've got my + +ideal gas in some container. + +There's some energy, some +internal energy. + +Now I make the volume bigger. + +I allow it to expand. + +And the energy changes, +it goes up. + +In some sense it's less +favorable energetically. + +What's happening there, that a +term in the van der Waal's + +equation of state, is describing +interactions, + +favorable attractions, between +gas molecules. + +The b is describing +repulsions. + +Effectively, the +volume changes. + +The molar volume is being +changed a little bit by the + +fact that if you're really +trying to make things collide + +with each other, they can't +occupy the same volume. + +And that is being +expressed here. + +The a, though is expressing +attraction between molecules + +at somewhat longer range. + +So now, if you make the +volume bigger, those + +attractions die out. + +Because the molecules are +farther apart from each other. + +So the energy goes up. + +Now, you might ask, well why +does it do that, right? + +I mean, if the energy is lower +to occupy a smaller volume, + +then if I have this room and a +bunch of molecules of oxygen, + +and nitrogen and what have you +in the air, and there are weak + +attractions between them, why +don't they all just sort of + +glum together and find whatever +volume they like. + +So that the attractive +forces can exert + +themselves a little bit. + +Not too close, right? + +Not so close that the +repulsions dominate. + +Why don't they do that? + +What else matters besides any +of those considerations? + +What else matters that I haven't +considered in this + +little discussion? + +Yeah. + +What about entropy, right? + +If I only worry about +minimizing the + +energy, it's true. + +They'll stick together +a little bit. + +But entropy also matters. + +And there's disorder achieved +by occupying the full + +available volume. + +Many more states possible. + +And that will end up winning out +at basically any realistic + +temperature where the stuff +really is a gas. + +OK. + +Next time, what you're going +to see is the following. + +It turns out we can express all +these functions in terms + +of G, we wouldn't need to choose +G, but it's a very + +useful function to choose. + +Because of its natural +expression in + +terms of T and p. + +So we can write any of these +functions in terms of G. Which + +means that we can really +calculate all the + +thermodynamics in +terms of only g. + +It's not necessary to do that, +but it can be quite + +convenient. + +And then we can say, OK, if we +have many constituents, what + +if we have a mixture of stuff? + +We can take the derivative of +G with respect to how much + +material there is. + +With respect to n, the +number of moles. + +And if there are one, and two, +and three constituents with + +respect to n1, and n2, and n3. + +Each individual amount +of stuff. + +What that's going to allow us to +do is, if we say, OK I have + +a mixture of stuff, how does +the free energy change? + +If I change the composition +of the mixture? + +If I take something away, or +put something else in? + +And we'll be able to determine +equilibrium under those + +conditions. + +That's very useful for things +like chemical reactions, where + +this constituent changes +to this one. + +And I can calculate what happens +to G under those + +conditions. + +And that's what you'll see +starting next time. + +And professor Blendi +will be taking over + +for that set of lectures. \ No newline at end of file diff --git a/tBhR9hZLf0c.txt b/tBhR9hZLf0c.txt new file mode 100644 index 0000000000000000000000000000000000000000..f208c0674b93a5a9ed996185599d79cee3ec5e8e --- /dev/null +++ b/tBhR9hZLf0c.txt @@ -0,0 +1,13163 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to 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you're saying is a +trajectory that uh we start so it's it's + + align:start position:0% +trajectory that uh we start so it's it's + + + align:start position:0% +trajectory that uh we start so it's it's +a very steep time we start from a very + + align:start position:0% +a very steep time we start from a very + + + align:start position:0% +a very steep time we start from a very +basic thinking and then really trying to + + align:start position:0% +basic thinking and then really trying to + + + align:start position:0% +basic thinking and then really trying to +understand the materials what determin + + align:start position:0% +understand the materials what determin + + + align:start position:0% +understand the materials what determin +the material + + align:start position:0% +the material + + + align:start position:0% +the material +properties and uh uh this lecture I what + + align:start position:0% +properties and uh uh this lecture I what + + + align:start position:0% +properties and uh uh this lecture I what +I'm hoping after I close up with you uh + + align:start position:0% +I'm hoping after I close up with you uh + + + align:start position:0% +I'm hoping after I close up with you uh +listen topic conductivity what I'm Hing + + align:start position:0% +listen topic conductivity what I'm Hing + + + align:start position:0% +listen topic conductivity what I'm Hing +hoping is bring you to re from here what + + align:start position:0% +hoping is bring you to re from here what + + + align:start position:0% +hoping is bring you to re from here what +people are thinking in making materials + + align:start position:0% +people are thinking in making materials + + + align:start position:0% +people are thinking in making materials +better so uh but uh let me start with uh + + align:start position:0% +better so uh but uh let me start with uh + + + align:start position:0% +better so uh but uh let me start with uh +a very brief + + align:start position:0% +a very brief + + + align:start position:0% +a very brief +review uh of last lecture um uh we show + + align:start position:0% +review uh of last lecture um uh we show + + + align:start position:0% +review uh of last lecture um uh we show +uh one is simple remember my picture + + align:start position:0% +uh one is simple remember my picture + + + align:start position:0% +uh one is simple remember my picture +always simple picture always from left + + align:start position:0% +always simple picture always from left + + + align:start position:0% +always simple picture always from left +to right and right to left and the + + align:start position:0% +to right and right to left and the + + + align:start position:0% +to right and right to left and the +difference gives the the FL uh so from + + align:start position:0% +difference gives the the FL uh so from + + + align:start position:0% +difference gives the the FL uh so from +there we show General relation uh the + + align:start position:0% +there we show General relation uh the + + + align:start position:0% +there we show General relation uh the +current + + align:start position:0% +current + + + align:start position:0% +current +flux this the uh current flux is related + + align:start position:0% +flux this the uh current flux is related + + + align:start position:0% +flux this the uh current flux is related +to electrostatic potential so that's the + + align:start position:0% +to electrostatic potential so that's the + + + align:start position:0% +to electrostatic potential so that's the +charge driving force for charge flow and + + align:start position:0% +charge driving force for charge flow and + + + align:start position:0% +charge driving force for charge flow and +then we will have a gradient is + + align:start position:0% +then we will have a gradient is + + + align:start position:0% +then we will have a gradient is +toter so now you see the electricity to + + align:start position:0% +toter so now you see the electricity to + + + align:start position:0% +toter so now you see the electricity to +he and then this one shows the Heat + + align:start position:0% +he and then this one shows the Heat + + + align:start position:0% +he and then this one shows the Heat +current so really now electron is + + align:start position:0% +current so really now electron is + + + align:start position:0% +current so really now electron is +carrying the heat as Heat current + + align:start position:0% +carrying the heat as Heat current + + + align:start position:0% +carrying the heat as Heat current +electric current Heat current is again + + align:start position:0% +electric current Heat current is again + + + align:start position:0% +electric current Heat current is again +coupl in this Cas not just + + align:start position:0% +coupl in this Cas not just + + + align:start position:0% +coupl in this Cas not just +to but also to the elal + + align:start position:0% +to but also to the elal + + + align:start position:0% +to but also to the elal +potential and uh this is a very general + + align:start position:0% +potential and uh this is a very general + + + align:start position:0% +potential and uh this is a very general +answer relation if I have read this + + align:start position:0% +answer relation if I have read this + + + align:start position:0% +answer relation if I have read this +really this radi in terms of generalized + + align:start position:0% +really this radi in terms of generalized + + + align:start position:0% +really this radi in terms of generalized +force uh is this coefficient + + align:start position:0% +force uh is this coefficient + + + align:start position:0% +force uh is this coefficient +CR this + + align:start position:0% +CR this + + + align:start position:0% +CR this +what the price + + align:start position:0% +what the price + + + align:start position:0% +what the price +before and uh then uh I gave some we use + + align:start position:0% +before and uh then uh I gave some we use + + + align:start position:0% +before and uh then uh I gave some we use +the some of the concept we learned + + align:start position:0% +the some of the concept we learned + + + align:start position:0% +the some of the concept we learned +before for example density of states and + + align:start position:0% +before for example density of states and + + + align:start position:0% +before for example density of states and +uh uh the uh uh we have expression for + + align:start position:0% +uh uh the uh uh we have expression for + + + align:start position:0% +uh uh the uh uh we have expression for +this coefficient l11 is the electric + + align:start position:0% +this coefficient l11 is the electric + + + align:start position:0% +this coefficient l11 is the electric +conductivity uh and those other + + align:start position:0% +conductivity uh and those other + + + align:start position:0% +conductivity uh and those other +coefficient from those other + + align:start position:0% +coefficient from those other + + + align:start position:0% +coefficient from those other +with + + align:start position:0% +with + + + align:start position:0% +with +c + + align:start position:0% +c + + + align:start position:0% +c +and uh let me just uh one remark that + + align:start position:0% +and uh let me just uh one remark that + + + align:start position:0% +and uh let me just uh one remark that +those expressions are not uh uh most + + align:start position:0% +those expressions are not uh uh most + + + align:start position:0% +those expressions are not uh uh most +General uh you can have different + + align:start position:0% +General uh you can have different + + + align:start position:0% +General uh you can have different +transort regim this is the regime that + + align:start position:0% +transort regim this is the regime that + + + align:start position:0% +transort regim this is the regime that +most people do the Boardman transort + + align:start position:0% +most people do the Boardman transort + + + align:start position:0% +most people do the Boardman transort +regime so those expression can rather + + align:start position:0% +regime so those expression can rather + + + align:start position:0% +regime so those expression can rather +than my time deration uh you can + + align:start position:0% +than my time deration uh you can + + + align:start position:0% +than my time deration uh you can +actually start from my equation derive + + align:start position:0% +actually start from my equation derive + + + align:start position:0% +actually start from my equation derive +those + + align:start position:0% +those + + + align:start position:0% +those +coefficients and uh uh I showed + + align:start position:0% +coefficients and uh uh I showed + + + align:start position:0% +coefficients and uh uh I showed +examples uh one thing that I want to uh + + align:start position:0% +examples uh one thing that I want to uh + + + align:start position:0% +examples uh one thing that I want to uh +emphasize is that the properties depends + + align:start position:0% +emphasize is that the properties depends + + + align:start position:0% +emphasize is that the properties depends +on temperature so different temperature + + align:start position:0% +on temperature so different temperature + + + align:start position:0% +on temperature so different temperature +uh you can see the property are changing + + align:start position:0% +uh you can see the property are changing + + + align:start position:0% +uh you can see the property are changing +uh for electric conductivity if you + + align:start position:0% +uh for electric conductivity if you + + + align:start position:0% +uh for electric conductivity if you +follow the simple Bo + + align:start position:0% +follow the simple Bo + + + align:start position:0% +follow the simple Bo +statistics uh you actually get the + + align:start position:0% +statistics uh you actually get the + + + align:start position:0% +statistics uh you actually get the +electric conductive in semiconductor we + + align:start position:0% +electric conductive in semiconductor we + + + align:start position:0% +electric conductive in semiconductor we +know typical micro electronic type of + + align:start position:0% +know typical micro electronic type of + + + align:start position:0% +know typical micro electronic type of +doping Electa the increase with + + align:start position:0% +doping Electa the increase with + + + align:start position:0% +doping Electa the increase with +temperature but for thric material so + + align:start position:0% +temperature but for thric material so + + + align:start position:0% +temperature but for thric material so +this is not right for thric material you + + align:start position:0% +this is not right for thric material you + + + align:start position:0% +this is not right for thric material you +can say theal contivity electric + + align:start position:0% +can say theal contivity electric + + + align:start position:0% +can say theal contivity electric +contivity decrease this temperature and + + align:start position:0% +contivity decrease this temperature and + + + align:start position:0% +contivity decrease this temperature and +that's because we doping very heavily + + align:start position:0% +that's because we doping very heavily + + + align:start position:0% +that's because we doping very heavily +metal is like this metal in metal the + + align:start position:0% +metal is like this metal in metal the + + + align:start position:0% +metal is like this metal in metal the +electric connectivity decreases because + + align:start position:0% +electric connectivity decreases because + + + align:start position:0% +electric connectivity decreases because +when you get a top they're not more Fon + + align:start position:0% +when you get a top they're not more Fon + + + align:start position:0% +when you get a top they're not more Fon +the Aton atoms are vibrating more + + align:start position:0% +the Aton atoms are vibrating more + + + align:start position:0% +the Aton atoms are vibrating more +violently and that's scatter electron + + align:start position:0% +violently and that's scatter electron + + + align:start position:0% +violently and that's scatter electron +that's when why they will + + align:start position:0% +that's when why they will + + + align:start position:0% +that's when why they will +decrease and uh the + + align:start position:0% +decrease and uh the + + + align:start position:0% +decrease and uh the +CAC uh is typically have a peak and if + + align:start position:0% +CAC uh is typically have a peak and if + + + align:start position:0% +CAC uh is typically have a peak and if +you just talk simply one B Transport so + + align:start position:0% +you just talk simply one B Transport so + + + align:start position:0% +you just talk simply one B Transport so +one b means if I have a conduction B and + + align:start position:0% +one b means if I have a conduction B and + + + align:start position:0% +one b means if I have a conduction B and +if electron only uh going one through + + align:start position:0% +if electron only uh going one through + + + align:start position:0% +if electron only uh going one through +one conduction B then the theory say it + + align:start position:0% +one conduction B then the theory say it + + + align:start position:0% +one conduction B then the theory say it +should increase temperature because as + + align:start position:0% +should increase temperature because as + + + align:start position:0% +should increase temperature because as +the temperature increases the separation + + align:start position:0% +the temperature increases the separation + + + align:start position:0% +the temperature increases the separation +of the chemical potential from the + + align:start position:0% +of the chemical potential from the + + + align:start position:0% +of the chemical potential from the +bottom so you drive chemal potential to + + align:start position:0% +bottom so you drive chemal potential to + + + align:start position:0% +bottom so you drive chemal potential to +the center of the B but uh in uh almost + + align:start position:0% +the center of the B but uh in uh almost + + + align:start position:0% +the center of the B but uh in uh almost +all materials the behavior is will peit + + align:start position:0% +all materials the behavior is will peit + + + align:start position:0% +all materials the behavior is will peit +at some temperature and start to + + align:start position:0% +at some temperature and start to + + + align:start position:0% +at some temperature and start to +decrease and the reason is uh as the + + align:start position:0% +decrease and the reason is uh as the + + + align:start position:0% +decrease and the reason is uh as the +temperature increase you exide uh the + + align:start position:0% +temperature increase you exide uh the + + + align:start position:0% +temperature increase you exide uh the +intrinsically you you you leave the + + align:start position:0% +intrinsically you you you leave the + + + align:start position:0% +intrinsically you you you leave the +thermal energy leave electron from the + + align:start position:0% +thermal energy leave electron from the + + + align:start position:0% +thermal energy leave electron from the +bance band with a hole behind D electron + + align:start position:0% +bance band with a hole behind D electron + + + align:start position:0% +bance band with a hole behind D electron +can so in this case now you have both + + align:start position:0% +can so in this case now you have both + + + align:start position:0% +can so in this case now you have both +electron a hole so when you flow current + + align:start position:0% +electron a hole so when you flow current + + + align:start position:0% +electron a hole so when you flow current +electron carry energy in One Direction F + + align:start position:0% +electron carry energy in One Direction F + + + align:start position:0% +electron carry energy in One Direction F +carrent energy in the opposite direction + + align:start position:0% +carrent energy in the opposite direction + + + align:start position:0% +carrent energy in the opposite direction +so they cancel each other in this case + + align:start position:0% +so they cancel each other in this case + + + align:start position:0% +so they cancel each other in this case +you actually could get a higher electric + + align:start position:0% +you actually could get a higher electric + + + align:start position:0% +you actually could get a higher electric +conductivity but the C canel each other + + align:start position:0% +conductivity but the C canel each other + + + align:start position:0% +conductivity but the C canel each other +so this is when you look at experimental + + align:start position:0% +so this is when you look at experimental + + + align:start position:0% +so this is when you look at experimental +data it turns out the many C we do that + + align:start position:0% +data it turns out the many C we do that + + + align:start position:0% +data it turns out the many C we do that +say we cannot calculate exactly so we + + align:start position:0% +say we cannot calculate exactly so we + + + align:start position:0% +say we cannot calculate exactly so we +look at experiment this is what + + align:start position:0% +look at experiment this is what + + + align:start position:0% +look at experiment this is what +happening this is the why div and this + + align:start position:0% +happening this is the why div and this + + + align:start position:0% +happening this is the why div and this +is where okay how you can move this to + + align:start position:0% +is where okay how you can move this to + + + align:start position:0% +is where okay how you can move this to +higher + + align:start position:0% +higher + + + align:start position:0% +higher +temperature you if you have more + + align:start position:0% +temperature you if you have more + + + align:start position:0% +temperature you if you have more +electron you you do it more heavily you + + align:start position:0% +electron you you do it more heavily you + + + align:start position:0% +electron you you do it more heavily you +will go to higher temperature and if you + + align:start position:0% +will go to higher temperature and if you + + + align:start position:0% +will go to higher temperature and if you +have larger back Gap it's it's more + + align:start position:0% +have larger back Gap it's it's more + + + align:start position:0% +have larger back Gap it's it's more +difficult to generate the seral electron + + align:start position:0% +difficult to generate the seral electron + + + align:start position:0% +difficult to generate the seral electron +pole pair and then you can move this so + + align:start position:0% +pole pair and then you can move this so + + + align:start position:0% +pole pair and then you can move this so +that's how you look at different these + + align:start position:0% +that's how you look at different these + + + align:start position:0% +that's how you look at different these +different + + align:start position:0% +different + + + align:start position:0% +different +materials so that's where we were in the + + align:start position:0% +materials so that's where we were in the + + + align:start position:0% +materials so that's where we were in the +uh last uh lecture and those were many + + align:start position:0% +uh last uh lecture and those were many + + + align:start position:0% +uh last uh lecture and those were many +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +electrons and uh uh we also talk about + + align:start position:0% +electrons and uh uh we also talk about + + + align:start position:0% +electrons and uh uh we also talk about +the colon the concept of lce vibration + + align:start position:0% +the colon the concept of lce vibration + + + align:start position:0% +the colon the concept of lce vibration +and we give a very simple expression + + align:start position:0% +and we give a very simple expression + + + align:start position:0% +and we give a very simple expression +before on the phon thermal conductivity + + align:start position:0% +before on the phon thermal conductivity + + + align:start position:0% +before on the phon thermal conductivity +and again my picture is left to right + + align:start position:0% +and again my picture is left to right + + + align:start position:0% +and again my picture is left to right +right to left right so when I want to + + align:start position:0% +right to left right so when I want to + + + align:start position:0% +right to left right so when I want to +find out the heat flock going through + + align:start position:0% +find out the heat flock going through + + + align:start position:0% +find out the heat flock going through +any plan I see how much heat is going + + align:start position:0% +any plan I see how much heat is going + + + align:start position:0% +any plan I see how much heat is going +from one side to the other without + + align:start position:0% +from one side to the other without + + + align:start position:0% +from one side to the other without +scattering so this is with one + + align:start position:0% +scattering so this is with one + + + align:start position:0% +scattering so this is with one +relaxation time and how much from left + + align:start position:0% +relaxation time and how much from left + + + align:start position:0% +relaxation time and how much from left +to + + align:start position:0% +to + + + align:start position:0% +to +right time the difference give me the + + align:start position:0% +right time the difference give me the + + + align:start position:0% +right time the difference give me the +and what I want to do a little bit more + + align:start position:0% +and what I want to do a little bit more + + + align:start position:0% +and what I want to do a little bit more +better compy uh meaning before I just + + align:start position:0% +better compy uh meaning before I just + + + align:start position:0% +better compy uh meaning before I just +say this is lber density n right per + + align:start position:0% +say this is lber density n right per + + + align:start position:0% +say this is lber density n right per +unit volume now I'm going to do modes so + + align:start position:0% +unit volume now I'm going to do modes so + + + align:start position:0% +unit volume now I'm going to do modes so +I'm going to sum up so this is a uh it's + + align:start position:0% +I'm going to sum up so this is a uh it's + + + align:start position:0% +I'm going to sum up so this is a uh it's +the same as as what I draw here but here + + align:start position:0% +the same as as what I draw here but here + + + align:start position:0% +the same as as what I draw here but here +is uh more rigorous so this is the + + align:start position:0% +is uh more rigorous so this is the + + + align:start position:0% +is uh more rigorous so this is the +energy of + + align:start position:0% +energy of + + + align:start position:0% +energy of +one lce vibration form of lce vibration + + align:start position:0% +one lce vibration form of lce vibration + + + align:start position:0% +one lce vibration form of lce vibration +so one F and then this is perum mechanic + + align:start position:0% +so one F and then this is perum mechanic + + + align:start position:0% +so one F and then this is perum mechanic +modes that's both Einstein distribution + + align:start position:0% +modes that's both Einstein distribution + + + align:start position:0% +modes that's both Einstein distribution +right per mole per state Quantum State + + align:start position:0% +right per mole per state Quantum State + + + align:start position:0% +right per mole per state Quantum State +how many Fon you + + align:start position:0% +how many Fon you + + + align:start position:0% +how many Fon you +have right and this is the velocity so + + align:start position:0% +have right and this is the velocity so + + + align:start position:0% +have right and this is the velocity so +this is a so this is really telling me + + align:start position:0% +this is a so this is really telling me + + + align:start position:0% +this is a so this is really telling me +per quantum mechanical mode how many + + align:start position:0% +per quantum mechanical mode how many + + + align:start position:0% +per quantum mechanical mode how many +Fons is moving to the forward positive X + + align:start position:0% +Fons is moving to the forward positive X + + + align:start position:0% +Fons is moving to the forward positive X +Direction the one half gives me half + + align:start position:0% +Direction the one half gives me half + + + align:start position:0% +Direction the one half gives me half +random motion so the idea is the same + + align:start position:0% +random motion so the idea is the same + + + align:start position:0% +random motion so the idea is the same +but now I'm trying to do little a better + + align:start position:0% +but now I'm trying to do little a better + + + align:start position:0% +but now I'm trying to do little a better +job cting better cting job and here what + + align:start position:0% +job cting better cting job and here what + + + align:start position:0% +job cting better cting job and here what +we have this is remember in the second + + align:start position:0% +we have this is remember in the second + + + align:start position:0% +we have this is remember in the second +lecture I was doing black body black + + align:start position:0% +lecture I was doing black body black + + + align:start position:0% +lecture I was doing black body black +body radiation right so this is the + + align:start position:0% +body radiation right so this is the + + + align:start position:0% +body radiation right so this is the +counting all the mechanic allow M KX + + align:start position:0% +counting all the mechanic allow M KX + + + align:start position:0% +counting all the mechanic allow M KX +with vectors right it's a for on with KX + + align:start position:0% +with vectors right it's a for on with KX + + + align:start position:0% +with vectors right it's a for on with KX +KY k z so I'm suing up all those modes + + align:start position:0% +KY k z so I'm suing up all those modes + + + align:start position:0% +KY k z so I'm suing up all those modes +and that's from left to right minus from + + align:start position:0% +and that's from left to right minus from + + + align:start position:0% +and that's from left to right minus from +right to left give me the left FL so + + align:start position:0% +right to left give me the left FL so + + + align:start position:0% +right to left give me the left FL so +that's what I uh we show before in + + align:start position:0% +that's what I uh we show before in + + + align:start position:0% +that's what I uh we show before in +simpler form but if I do + + align:start position:0% +simpler form but if I do + + + align:start position:0% +simpler form but if I do +this okay and I will get the integral no + + align:start position:0% +this okay and I will get the integral no + + + align:start position:0% +this okay and I will get the integral no +longer just a simple 1/3 CB GMA that's + + align:start position:0% +longer just a simple 1/3 CB GMA that's + + + align:start position:0% +longer just a simple 1/3 CB GMA that's +what we have before and now it's + + align:start position:0% +what we have before and now it's + + + align:start position:0% +what we have before and now it's +integration of all the frequency + + align:start position:0% +integration of all the frequency + + + align:start position:0% +integration of all the frequency +frequency remember fall so the acoustic + + align:start position:0% +frequency remember fall so the acoustic + + + align:start position:0% +frequency remember fall so the acoustic +wave the uh for example low frequency + + align:start position:0% +wave the uh for example low frequency + + + align:start position:0% +wave the uh for example low frequency +acoustic wave that's what you hear and + + align:start position:0% +acoustic wave that's what you hear and + + + align:start position:0% +acoustic wave that's what you hear and +uh they have uh uh the different mean + + align:start position:0% +uh they have uh uh the different mean + + + align:start position:0% +uh they have uh uh the different mean +free paths different group velocity the + + align:start position:0% +free paths different group velocity the + + + align:start position:0% +free paths different group velocity the +higher frequency ones so this can all + + align:start position:0% +higher frequency ones so this can all + + + align:start position:0% +higher frequency ones so this can all +change as a function frequency what we + + align:start position:0% +change as a function frequency what we + + + align:start position:0% +change as a function frequency what we +writing now is the more RoR form for the + + align:start position:0% +writing now is the more RoR form for the + + + align:start position:0% +writing now is the more RoR form for the +thermal conductivity uh carry e + + align:start position:0% +thermal conductivity uh carry e + + + align:start position:0% +thermal conductivity uh carry e +conduction by the L + + align:start position:0% + + + + align:start position:0% + +L okay so this is a about material right + + align:start position:0% +L okay so this is a about material right + + + align:start position:0% +L okay so this is a about material right +and people have measur the theral + + align:start position:0% +and people have measur the theral + + + align:start position:0% +and people have measur the theral +conductivity and this is a typical curve + + align:start position:0% +conductivity and this is a typical curve + + + align:start position:0% +conductivity and this is a typical curve +of Thal conductivity of material versus + + align:start position:0% +of Thal conductivity of material versus + + + align:start position:0% +of Thal conductivity of material versus +temperature and this is specific example + + align:start position:0% +temperature and this is specific example + + + align:start position:0% +temperature and this is specific example +ofum oite and you can say uh there's a + + align:start position:0% +ofum oite and you can say uh there's a + + + align:start position:0% +ofum oite and you can say uh there's a +peak this is B matal this peak is + + align:start position:0% +peak this is B matal this peak is + + + align:start position:0% +peak this is B matal this peak is +typically between 10 to 20 + + align:start position:0% +typically between 10 to 20 + + + align:start position:0% +typically between 10 to 20 +K and then after the PE the drops below + + align:start position:0% +K and then after the PE the drops below + + + align:start position:0% +K and then after the PE the drops below +the + + align:start position:0% +the + + + align:start position:0% +the +in and this actually reflects different + + align:start position:0% +in and this actually reflects different + + + align:start position:0% +in and this actually reflects different +physics so at a very high + + align:start position:0% +physics so at a very high + + + align:start position:0% +physics so at a very high +temperature okay the uh each mold carry + + align:start position:0% +temperature okay the uh each mold carry + + + align:start position:0% +temperature okay the uh each mold carry +energy KT right so the L uh the L of + + align:start position:0% +energy KT right so the L uh the L of + + + align:start position:0% +energy KT right so the L uh the L of +fance is also proportional to T + + align:start position:0% +fance is also proportional to T + + + align:start position:0% +fance is also proportional to T +temperature and in this case case what + + align:start position:0% +temperature and in this case case what + + + align:start position:0% +temperature and in this case case what +happens because as the temperature + + align:start position:0% +happens because as the temperature + + + align:start position:0% +happens because as the temperature +increases you inside more + + align:start position:0% +increases you inside more + + + align:start position:0% +increases you inside more +Fons and they scatter each other they + + align:start position:0% +Fons and they scatter each other they + + + align:start position:0% +Fons and they scatter each other they +scatter each other and they drop the Cal + + align:start position:0% +scatter each other and they drop the Cal + + + align:start position:0% +scatter each other and they drop the Cal +conductivity so that's why the Cal + + align:start position:0% +conductivity so that's why the Cal + + + align:start position:0% +conductivity so that's why the Cal +conductiv is dropping and in fact if you + + align:start position:0% +conductiv is dropping and in fact if you + + + align:start position:0% +conductiv is dropping and in fact if you +follow the arum I + + align:start position:0% +follow the arum I + + + align:start position:0% +follow the arum I +saying the L is proportional to T the + + align:start position:0% +saying the L is proportional to T the + + + align:start position:0% +saying the L is proportional to T the +contivity iners proportional to Surf to + + align:start position:0% +contivity iners proportional to Surf to + + + align:start position:0% +contivity iners proportional to Surf to +temperature but see that's a simple + + align:start position:0% +temperature but see that's a simple + + + align:start position:0% +temperature but see that's a simple +picture and then + + align:start position:0% +picture and then + + + align:start position:0% +picture and then +this exponent is not one it's typic + + align:start position:0% +this exponent is not one it's typic + + + align:start position:0% +this exponent is not one it's typic +depend on matal 1.5 people Z are trying + + align:start position:0% +depend on matal 1.5 people Z are trying + + + align:start position:0% +depend on matal 1.5 people Z are trying +to figure out Y is not exactly + + align:start position:0% +to figure out Y is not exactly + + + align:start position:0% +to figure out Y is not exactly +one okay so this is a higher temperature + + align:start position:0% +one okay so this is a higher temperature + + + align:start position:0% +one okay so this is a higher temperature +range and as you go to lower temperature + + align:start position:0% +range and as you go to lower temperature + + + align:start position:0% +range and as you go to lower temperature +the foron foron scal the lightest W + + align:start position:0% +the foron foron scal the lightest W + + + align:start position:0% +the foron foron scal the lightest W +interaction with itself becomes weaker + + align:start position:0% +interaction with itself becomes weaker + + + align:start position:0% +interaction with itself becomes weaker +so in this case what so the ther cond + + align:start position:0% +so in this case what so the ther cond + + + align:start position:0% +so in this case what so the ther cond +increase right even though if you go to + + align:start position:0% +increase right even though if you go to + + + align:start position:0% +increase right even though if you go to +check specific heat specific heat of the + + align:start position:0% +check specific heat specific heat of the + + + align:start position:0% +check specific heat specific heat of the +which in in this dialectric is due to FS + + align:start position:0% +which in in this dialectric is due to FS + + + align:start position:0% +which in in this dialectric is due to FS +specific is typically this curve okay I + + align:start position:0% +specific is typically this curve okay I + + + align:start position:0% +specific is typically this curve okay I +Q one and it's not a constant uh it + + align:start position:0% +Q one and it's not a constant uh it + + + align:start position:0% +Q one and it's not a constant uh it +increase from low time to high + + align:start position:0% +increase from low time to high + + + align:start position:0% +increase from low time to high +temperature but Thal conductivity so + + align:start position:0% +temperature but Thal conductivity so + + + align:start position:0% +temperature but Thal conductivity so +even though there less energy + + align:start position:0% +even though there less energy + + + align:start position:0% +even though there less energy +specifically the measure of full energy + + align:start position:0% +specifically the measure of full energy + + + align:start position:0% +specifically the measure of full energy +less energy in this region compared this + + align:start position:0% +less energy in this region compared this + + + align:start position:0% +less energy in this region compared this +region but because L scatter the goes + + align:start position:0% +region but because L scatter the goes + + + align:start position:0% +region but because L scatter the goes +longer so the Thal conductivity actually + + align:start position:0% +longer so the Thal conductivity actually + + + align:start position:0% +longer so the Thal conductivity actually +incre okay so the uh so in this region + + align:start position:0% +incre okay so the uh so in this region + + + align:start position:0% +incre okay so the uh so in this region +is + + align:start position:0% +is + + + align:start position:0% +is +typically scatter is no longer dominant + + align:start position:0% +typically scatter is no longer dominant + + + align:start position:0% +typically scatter is no longer dominant +is you got a impurity atoms so for + + align:start position:0% +is you got a impurity atoms so for + + + align:start position:0% +is you got a impurity atoms so for +example in Silicon if you + + align:start position:0% +example in Silicon if you + + + align:start position:0% +example in Silicon if you +have phosphor or Boron you dop it right + + align:start position:0% +have phosphor or Boron you dop it right + + + align:start position:0% +have phosphor or Boron you dop it right +they are lighter so you think about it + + align:start position:0% +they are lighter so you think about it + + + align:start position:0% +they are lighter so you think about it +you have a Str again Fon is the larest + + align:start position:0% +you have a Str again Fon is the larest + + + align:start position:0% +you have a Str again Fon is the larest +you have the same mass for and suddenly + + align:start position:0% +you have the same mass for and suddenly + + + align:start position:0% +you have the same mass for and suddenly +you put a different + + align:start position:0% +you put a different + + + align:start position:0% +you put a different +mass that created some scaling of the of + + align:start position:0% +mass that created some scaling of the of + + + align:start position:0% +mass that created some scaling of the of +the waves and so this is the region + + align:start position:0% +the waves and so this is the region + + + align:start position:0% +the waves and so this is the region +where the + + align:start position:0% +where the + + + align:start position:0% +where the +limit uh the peak here is very much + + align:start position:0% +limit uh the peak here is very much + + + align:start position:0% +limit uh the peak here is very much +limited by this impurities in the + + align:start position:0% +limited by this impurities in the + + + align:start position:0% +limited by this impurities in the +material and + + align:start position:0% +material and + + + align:start position:0% +material and +then when you go to very low temperature + + align:start position:0% +then when you go to very low temperature + + + align:start position:0% +then when you go to very low temperature +so the M pass becomes very long in fact + + align:start position:0% +so the M pass becomes very long in fact + + + align:start position:0% +so the M pass becomes very long in fact +even you make a make a measure make a b + + align:start position:0% +even you make a make a measure make a b + + + align:start position:0% +even you make a make a measure make a b +material the the me fre pass is longer + + align:start position:0% +material the the me fre pass is longer + + + align:start position:0% +material the the me fre pass is longer +than your + + align:start position:0% +than your + + + align:start position:0% +than your +sze so in this case the boundary scatter + + align:start position:0% +sze so in this case the boundary scatter + + + align:start position:0% +sze so in this case the boundary scatter +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +dominant and the mean free pass L longer + + align:start position:0% +dominant and the mean free pass L longer + + + align:start position:0% +dominant and the mean free pass L longer +dependent on the frequency but depend on + + align:start position:0% +dependent on the frequency but depend on + + + align:start position:0% +dependent on the frequency but depend on +is limited by the sample size so in this + + align:start position:0% +is limited by the sample size so in this + + + align:start position:0% +is limited by the sample size so in this +region the theral conductivity that is + + align:start position:0% +region the theral conductivity that is + + + align:start position:0% +region the theral conductivity that is +exactly due + + align:start position:0% +exactly due + + + align:start position:0% +exactly due +to uh yeah due to the specific so the + + align:start position:0% +to uh yeah due to the specific so the + + + align:start position:0% +to uh yeah due to the specific so the +behavior just + + align:start position:0% +behavior just + + + align:start position:0% +behavior just +speciic + + align:start position:0% +speciic + + + align:start position:0% +speciic +sample so yes no question because I just + + align:start position:0% +sample so yes no question because I just + + + align:start position:0% +sample so yes no question because I just +think because spef + + align:start position:0% +think because spef + + + align:start position:0% +think because spef +all why that's exactly the reason right + + align:start position:0% +all why that's exactly the reason right + + + align:start position:0% +all why that's exactly the reason right +so by the way this is why black body + + align:start position:0% +so by the way this is why black body + + + align:start position:0% +so by the way this is why black body +radiation the fourth power right + + align:start position:0% +radiation the fourth power right + + + align:start position:0% +radiation the fourth power right +specific is the third power the energy + + align:start position:0% +specific is the third power the energy + + + align:start position:0% +specific is the third power the energy +is Du DT so if you integrate the energy + + align:start position:0% +is Du DT so if you integrate the energy + + + align:start position:0% +is Du DT so if you integrate the energy +is the temperature Force Power and Fon + + align:start position:0% +is the temperature Force Power and Fon + + + align:start position:0% +is the temperature Force Power and Fon +Photon this is regime unfortunately this + + align:start position:0% +Photon this is regime unfortunately this + + + align:start position:0% +Photon this is regime unfortunately this +is very low temperature regime but this + + align:start position:0% +is very low temperature regime but this + + + align:start position:0% +is very low temperature regime but this +is regime Fon behave almost identically + + align:start position:0% +is regime Fon behave almost identically + + + align:start position:0% +is regime Fon behave almost identically +to full no scatter very weak scatter so + + align:start position:0% +to full no scatter very weak scatter so + + + align:start position:0% +to full no scatter very weak scatter so +uh you can see the + + align:start position:0% +uh you can see the + + + align:start position:0% +uh you can see the +temperature power is the + + align:start position:0% +temperature power is the + + + align:start position:0% +temperature power is the +same okay so that's that's a typical + + align:start position:0% +same okay so that's that's a typical + + + align:start position:0% +same okay so that's that's a typical +behavior of lat theral conductivity in C + + align:start position:0% +behavior of lat theral conductivity in C + + + align:start position:0% +behavior of lat theral conductivity in C +and just give one example the highest + + align:start position:0% +and just give one example the highest + + + align:start position:0% +and just give one example the highest +thermal conductivity materal + + align:start position:0% +thermal conductivity materal + + + align:start position:0% +thermal conductivity materal +diamond and if you purify the diamond + + align:start position:0% +diamond and if you purify the diamond + + + align:start position:0% +diamond and if you purify the diamond +you can change this P by uh from uh this + + align:start position:0% +you can change this P by uh from uh this + + + align:start position:0% +you can change this P by uh from uh this +P di at room temperature is about 2,000 + + align:start position:0% +P di at room temperature is about 2,000 + + + align:start position:0% +P di at room temperature is about 2,000 +and that PE will go very high and if you + + align:start position:0% +and that PE will go very high and if you + + + align:start position:0% +and that PE will go very high and if you +purify just say even + + align:start position:0% +purify just say even + + + align:start position:0% +purify just say even +Isotopes right carbon 12 versus carbon + + align:start position:0% +Isotopes right carbon 12 versus carbon + + + align:start position:0% +Isotopes right carbon 12 versus carbon +13 can significant limit this uh the you + + align:start position:0% +13 can significant limit this uh the you + + + align:start position:0% +13 can significant limit this uh the you +my room temperature uh the theral + + align:start position:0% +my room temperature uh the theral + + + align:start position:0% +my room temperature uh the theral +connectivity will be influenced by the + + align:start position:0% +connectivity will be influenced by the + + + align:start position:0% +connectivity will be influenced by the +just the + + align:start position:0% + + + + align:start position:0% + +is okay so now if I combine the theral + + align:start position:0% +is okay so now if I combine the theral + + + align:start position:0% +is okay so now if I combine the theral +conductivity right it turns out lce has + + align:start position:0% +conductivity right it turns out lce has + + + align:start position:0% +conductivity right it turns out lce has +a + + align:start position:0% +a + + + align:start position:0% +a +contribution the electron also carry + + align:start position:0% +contribution the electron also carry + + + align:start position:0% +contribution the electron also carry +here so if I have electron I have hole + + align:start position:0% +here so if I have electron I have hole + + + align:start position:0% +here so if I have electron I have hole +hole also carries here right so I have + + align:start position:0% +hole also carries here right so I have + + + align:start position:0% +hole also carries here right so I have +electron hole and then I mention uh the + + align:start position:0% +electron hole and then I mention uh the + + + align:start position:0% +electron hole and then I mention uh the +uh when they move when electron hold or + + align:start position:0% +uh when they move when electron hold or + + + align:start position:0% +uh when they move when electron hold or +fuse they uh at the higher temperature + + align:start position:0% +fuse they uh at the higher temperature + + + align:start position:0% +fuse they uh at the higher temperature +region you may get more electron ho when + + align:start position:0% +region you may get more electron ho when + + + align:start position:0% +region you may get more electron ho when +you go to lower temperature region they + + align:start position:0% +you go to lower temperature region they + + + align:start position:0% +you go to lower temperature region they +have less electron hole what happens the + + align:start position:0% +have less electron hole what happens the + + + align:start position:0% +have less electron hole what happens the +electron and the hole will combine each + + align:start position:0% +electron and the hole will combine each + + + align:start position:0% +electron and the hole will combine each +with each other and give up heat so in + + align:start position:0% +with each other and give up heat so in + + + align:start position:0% +with each other and give up heat so in +that case they they carry really + + align:start position:0% +that case they they carry really + + + align:start position:0% +that case they they carry really +potential energy from one place to other + + align:start position:0% +potential energy from one place to other + + + align:start position:0% +potential energy from one place to other +and this is a bipol contribution which + + align:start position:0% +and this is a bipol contribution which + + + align:start position:0% +and this is a bipol contribution which +is really bad for Thermo elrics so uh uh + + align:start position:0% +is really bad for Thermo elrics so uh uh + + + align:start position:0% +is really bad for Thermo elrics so uh uh +this is + + align:start position:0% +this is + + + align:start position:0% +this is +example most people do Thermo + + align:start position:0% +example most people do Thermo + + + align:start position:0% +example most people do Thermo +electrics don't pay attention to this + + align:start position:0% +electrics don't pay attention to this + + + align:start position:0% +electrics don't pay attention to this +and uh uh that's wrong okay uh for + + align:start position:0% +and uh uh that's wrong okay uh for + + + align:start position:0% +and uh uh that's wrong okay uh for +example the electronic contribution you + + align:start position:0% +example the electronic contribution you + + + align:start position:0% +example the electronic contribution you +can calculate from with right the + + align:start position:0% +can calculate from with right the + + + align:start position:0% +can calculate from with right the +electric conductivity divide by + + align:start position:0% +electric conductivity divide by + + + align:start position:0% +electric conductivity divide by +conductivity temp constant mention so + + align:start position:0% +conductivity temp constant mention so + + + align:start position:0% +conductivity temp constant mention so +many people would do this they will + + align:start position:0% +many people would do this they will + + + align:start position:0% +many people would do this they will +calculate this term and this term and + + align:start position:0% +calculate this term and this term and + + + align:start position:0% +calculate this term and this term and +they measure this term and they subtract + + align:start position:0% +they measure this term and they subtract + + + align:start position:0% +they measure this term and they subtract +the difference to give you the L but + + align:start position:0% +the difference to give you the L but + + + align:start position:0% +the difference to give you the L but +they don't calculate this term okay and + + align:start position:0% +they don't calculate this term okay and + + + align:start position:0% +they don't calculate this term okay and +this is actually difficult to calculate + + align:start position:0% +this is actually difficult to calculate + + + align:start position:0% +this is actually difficult to calculate +see and that's the reason and but you + + align:start position:0% +see and that's the reason and but you + + + align:start position:0% +see and that's the reason and but you +can see that the Thal conductivity at + + align:start position:0% +can see that the Thal conductivity at + + + align:start position:0% +can see that the Thal conductivity at +higher temperature goes + + align:start position:0% +higher temperature goes + + + align:start position:0% +higher temperature goes +up okay the lat Thal conductivity always + + align:start position:0% +up okay the lat Thal conductivity always + + + align:start position:0% +up okay the lat Thal conductivity always +goes down and the reason for this goes + + align:start position:0% +goes down and the reason for this goes + + + align:start position:0% +goes down and the reason for this goes +up is due to this term a very strong + + align:start position:0% +up is due to this term a very strong + + + align:start position:0% +up is due to this term a very strong +signature of bipolar C conductivity from + + align:start position:0% +signature of bipolar C conductivity from + + + align:start position:0% +signature of bipolar C conductivity from +electron + + align:start position:0% +electron + + + align:start position:0% +electron +and and and corresponding the cback goes + + align:start position:0% +and and and corresponding the cback goes + + + align:start position:0% +and and and corresponding the cback goes +down right the catback because the + + align:start position:0% +down right the catback because the + + + align:start position:0% +down right the catback because the +electron hold cancel that Fe but the Cal + + align:start position:0% +electron hold cancel that Fe but the Cal + + + align:start position:0% +electron hold cancel that Fe but the Cal +conductivity is still getting both terms + + align:start position:0% + + + + align:start position:0% + +inal okay so now let's go back I've + + align:start position:0% +inal okay so now let's go back I've + + + align:start position:0% +inal okay so now let's go back I've +talked a long time on this figure of + + align:start position:0% +talked a long time on this figure of + + + align:start position:0% +talked a long time on this figure of +marriage this parameter + + align:start position:0% +marriage this parameter + + + align:start position:0% +marriage this parameter +electric C conductivity and we SP the C + + align:start position:0% +electric C conductivity and we SP the C + + + align:start position:0% +electric C conductivity and we SP the C +conductivity into electronic part colon + + align:start position:0% +conductivity into electronic part colon + + + align:start position:0% +conductivity into electronic part colon +part and uh now if I divide this uh by + + align:start position:0% +part and uh now if I divide this uh by + + + align:start position:0% +part and uh now if I divide this uh by +the uh electric conductivity so here I + + align:start position:0% +the uh electric conductivity so here I + + + align:start position:0% +the uh electric conductivity so here I +have laen + + align:start position:0% +have laen + + + align:start position:0% +have laen +L and here I full on by so Sigma T right + + align:start position:0% +L and here I full on by so Sigma T right + + + align:start position:0% +L and here I full on by so Sigma T right +that's just the um say simple + + align:start position:0% +that's just the um say simple + + + align:start position:0% +that's just the um say simple +manipulation and the lawence L + + align:start position:0% +manipulation and the lawence L + + + align:start position:0% +manipulation and the lawence L +in metal that's the exact L but when you + + align:start position:0% +in metal that's the exact L but when you + + + align:start position:0% +in metal that's the exact L but when you +go semiconductor this depends on L so I + + align:start position:0% +go semiconductor this depends on L so I + + + align:start position:0% +go semiconductor this depends on L so I +have that's why I WR L function n but + + align:start position:0% +have that's why I WR L function n but + + + align:start position:0% +have that's why I WR L function n but +see if you look at it me C cancel each + + align:start position:0% +see if you look at it me C cancel each + + + align:start position:0% +see if you look at it me C cancel each +other the electron above the fir level + + align:start position:0% +other the electron above the fir level + + + align:start position:0% +other the electron above the fir level +electron below the fir level cancel each + + align:start position:0% +electron below the fir level cancel each + + + align:start position:0% +electron below the fir level cancel each +other you don't get + + align:start position:0% +other you don't get + + + align:start position:0% +other you don't get +a so you plug in those lepers the best + + align:start position:0% +a so you plug in those lepers the best + + + align:start position:0% +a so you plug in those lepers the best +you get most metal is about 01 + + align:start position:0% +you get most metal is about 01 + + + align:start position:0% +you get most metal is about 01 +okay when I first get into Ru the C + + align:start position:0% +okay when I first get into Ru the C + + + align:start position:0% +okay when I first get into Ru the C +Electric proposal I didn't know whether + + align:start position:0% +Electric proposal I didn't know whether + + + align:start position:0% +Electric proposal I didn't know whether +metal was good or bad or semiconductor + + align:start position:0% +metal was good or bad or semiconductor + + + align:start position:0% +metal was good or bad or semiconductor +so well now you take a + + align:start position:0% +so well now you take a + + + align:start position:0% +so well now you take a +good right B that's a example and C is + + align:start position:0% +good right B that's a example and C is + + + align:start position:0% +good right B that's a example and C is +about 200 microw + + align:start position:0% +about 200 microw + + + align:start position:0% +about 200 microw +per and is about + + align:start position:0% + + + + align:start position:0% + +one per meter so C is just the inverse + + align:start position:0% +one per meter so C is just the inverse + + + align:start position:0% +one per meter so C is just the inverse +of all right so that's the unit of + + align:start position:0% +of all right so that's the unit of + + + align:start position:0% +of all right so that's the unit of +connectivity and you plug in all those + + align:start position:0% +connectivity and you plug in all those + + + align:start position:0% +connectivity and you plug in all those +numbers and then you find that's of the + + align:start position:0% +numbers and then you find that's of the + + + align:start position:0% +numbers and then you find that's of the +order one so uh for from 1950s to 1990s + + align:start position:0% +order one so uh for from 1950s to 1990s + + + align:start position:0% +order one so uh for from 1950s to 1990s +the best thero electric material have a + + align:start position:0% +the best thero electric material have a + + + align:start position:0% +the best thero electric material have a +figure matter about one people have + + align:start position:0% +figure matter about one people have + + + align:start position:0% +figure matter about one people have +because of experimental you can't get + + align:start position:0% +because of experimental you can't get + + + align:start position:0% +because of experimental you can't get +better so people reading lot of papers + + align:start position:0% +better so people reading lot of papers + + + align:start position:0% +better so people reading lot of papers +on why we can't break this is the + + align:start position:0% +on why we can't break this is the + + + align:start position:0% +on why we can't break this is the +absolute maximum so whe they question + + align:start position:0% +absolute maximum so whe they question + + + align:start position:0% +absolute maximum so whe they question +whether their Theory trying to say why + + align:start position:0% +whether their Theory trying to say why + + + align:start position:0% +whether their Theory trying to say why +this is the maximum okay so this is the + + align:start position:0% +this is the maximum okay so this is the + + + align:start position:0% +this is the maximum okay so this is the +U uh uh the really the thetical + + align:start position:0% +U uh uh the really the thetical + + + align:start position:0% +U uh uh the really the thetical +foundation we talk and the last slides + + align:start position:0% +foundation we talk and the last slides + + + align:start position:0% +foundation we talk and the last slides +on this is a uh material I said + + align:start position:0% +on this is a uh material I said + + + align:start position:0% +on this is a uh material I said +sometimes you may get a really good one + + align:start position:0% +sometimes you may get a really good one + + + align:start position:0% +sometimes you may get a really good one +but you throw away because the do isn't + + align:start position:0% +but you throw away because the do isn't + + + align:start position:0% +but you throw away because the do isn't +right you can say that say because the + + align:start position:0% +right you can say that say because the + + + align:start position:0% +right you can say that say because the +dop determine where is the chemical + + align:start position:0% +dop determine where is the chemical + + + align:start position:0% +dop determine where is the chemical +potential right so the properties are so + + align:start position:0% +potential right so the properties are so + + + align:start position:0% +potential right so the properties are so +uh intertrend with each other C by + + align:start position:0% +uh intertrend with each other C by + + + align:start position:0% +uh intertrend with each other C by +coefficient as a function of dopin right + + align:start position:0% +coefficient as a function of dopin right + + + align:start position:0% +coefficient as a function of dopin right +here is bipolar in fact in fact this one + + align:start position:0% +here is bipolar in fact in fact this one + + + align:start position:0% +here is bipolar in fact in fact this one +why I have to check uh the electric + + align:start position:0% +why I have to check uh the electric + + + align:start position:0% +why I have to check uh the electric +conduc this looks better electric + + align:start position:0% +conduc this looks better electric + + + align:start position:0% +conduc this looks better electric +conductivity + + align:start position:0% +conductivity + + + align:start position:0% +conductivity +increases and thermal conductivity and + + align:start position:0% +increases and thermal conductivity and + + + align:start position:0% +increases and thermal conductivity and +you t z at certain + + align:start position:0% +you t z at certain + + + align:start position:0% +you t z at certain +value right so this is a clearly so you + + align:start position:0% +value right so this is a clearly so you + + + align:start position:0% +value right so this is a clearly so you +have to really TW your dopen that's say + + align:start position:0% +have to really TW your dopen that's say + + + align:start position:0% +have to really TW your dopen that's say +adding other materials or creating their + + align:start position:0% +adding other materials or creating their + + + align:start position:0% +adding other materials or creating their +different ways creating dopen carriers + + align:start position:0% +different ways creating dopen carriers + + + align:start position:0% +different ways creating dopen carriers +so this is uh the uh uh the difficulty + + align:start position:0% +so this is uh the uh uh the difficulty + + + align:start position:0% +so this is uh the uh uh the difficulty +with ther electric optimization not of + + align:start position:0% +with ther electric optimization not of + + + align:start position:0% +with ther electric optimization not of +work one has to + + align:start position:0% +work one has to + + + align:start position:0% +work one has to +do okay now we're going to really say + + align:start position:0% +do okay now we're going to really say + + + align:start position:0% +do okay now we're going to really say +What are the + + align:start position:0% +What are the + + + align:start position:0% +What are the +uh yes so that gra was it actually + + align:start position:0% +uh yes so that gra was it actually + + + align:start position:0% +uh yes so that gra was it actually +experim this Cur yeah this Cur for + + align:start position:0% +experim this Cur yeah this Cur for + + + align:start position:0% +experim this Cur yeah this Cur for +calculated right yeah the the typically + + align:start position:0% +calculated right yeah the the typically + + + align:start position:0% +calculated right yeah the the typically +when you say show dots that's mostly + + align:start position:0% +when you say show dots that's mostly + + + align:start position:0% +when you say show dots that's mostly +experiment + + align:start position:0% +experiment + + + align:start position:0% +experiment +okay okay those are experiment what do + + align:start position:0% +okay okay those are experiment what do + + + align:start position:0% +okay okay those are experiment what do +you see here in the experiment so this + + align:start position:0% +you see here in the experiment so this + + + align:start position:0% +you see here in the experiment so this +is a um uh say summary not always + + align:start position:0% +is a um uh say summary not always + + + align:start position:0% +is a um uh say summary not always +updated and people always recording + + align:start position:0% +updated and people always recording + + + align:start position:0% +updated and people always recording +program + + align:start position:0% +program + + + align:start position:0% +program +those days so uh here is a summary of ZT + + align:start position:0% +those days so uh here is a summary of ZT + + + align:start position:0% +those days so uh here is a summary of ZT +of different materials and what people + + align:start position:0% +of different materials and what people + + + align:start position:0% +of different materials and what people +have traditionally been using this cite + + align:start position:0% +have traditionally been using this cite + + + align:start position:0% +have traditionally been using this cite +that's in all modules uh commercial + + align:start position:0% +that's in all modules uh commercial + + + align:start position:0% +that's in all modules uh commercial +module you buy and this is the function + + align:start position:0% +module you buy and this is the function + + + align:start position:0% +module you buy and this is the function +of temperature right so this commercial + + align:start position:0% +of temperature right so this commercial + + + align:start position:0% +of temperature right so this commercial +uh CT kcks around room + + align:start position:0% +uh CT kcks around room + + + align:start position:0% +uh CT kcks around room +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +one and left and right is in the + + align:start position:0% +one and left and right is in the + + + align:start position:0% +one and left and right is in the +intermediate temperature 400° 500° right + + align:start position:0% +intermediate temperature 400° 500° right + + + align:start position:0% +intermediate temperature 400° 500° right +and the p is less than + + align:start position:0% + + + + align:start position:0% + +one89 and the SEC manual this is what + + align:start position:0% +one89 and the SEC manual this is what + + + align:start position:0% +one89 and the SEC manual this is what +Lassa has been using Lassa uses for + + align:start position:0% +Lassa has been using Lassa uses for + + + align:start position:0% +Lassa has been using Lassa uses for +space machines they use nuclear as a + + align:start position:0% +space machines they use nuclear as a + + + align:start position:0% +space machines they use nuclear as a +heat source and but they they build + + align:start position:0% +heat source and but they they build + + + align:start position:0% +heat source and but they they build +their system so the H side offer very + + align:start position:0% +their system so the H side offer very + + + align:start position:0% +their system so the H side offer very +high temperature so 6 manum is what L + + align:start position:0% +high temperature so 6 manum is what L + + + align:start position:0% +high temperature so 6 manum is what L +used in the past and remember if you + + align:start position:0% +used in the past and remember if you + + + align:start position:0% +used in the past and remember if you +want to build device you have to have + + align:start position:0% +want to build device you have to have + + + align:start position:0% +want to build device you have to have +both n type and P type materials so uh + + align:start position:0% +both n type and P type materials so uh + + + align:start position:0% +both n type and P type materials so uh +uh it's not all shown whether it's p + + align:start position:0% +uh it's not all shown whether it's p + + + align:start position:0% +uh it's not all shown whether it's p +type or n type but for each time you you + + align:start position:0% +type or n type but for each time you you + + + align:start position:0% +type or n type but for each time you you +build device you need both n and T and + + align:start position:0% +build device you need both n and T and + + + align:start position:0% +build device you need both n and T and +also ideally if we look uh go back to + + align:start position:0% +also ideally if we look uh go back to + + + align:start position:0% +also ideally if we look uh go back to +look at the notes in the uh device + + align:start position:0% +look at the notes in the uh device + + + align:start position:0% +look at the notes in the uh device +section when we talk about device you + + align:start position:0% +section when we talk about device you + + + align:start position:0% +section when we talk about device you +want this two materials closed + + align:start position:0% +want this two materials closed + + + align:start position:0% +want this two materials closed +properties closed otherwise it's not the + + align:start position:0% +properties closed otherwise it's not the + + + align:start position:0% +properties closed otherwise it's not the +material that determine your efficiency + + align:start position:0% +material that determine your efficiency + + + align:start position:0% +material that determine your efficiency +so uh you look at say the same P range + + align:start position:0% +so uh you look at say the same P range + + + align:start position:0% +so uh you look at say the same P range +what mats are + + align:start position:0% +what mats are + + + align:start position:0% +what mats are +below and uh like I said uh ZT has been + + align:start position:0% +below and uh like I said uh ZT has been + + + align:start position:0% +below and uh like I said uh ZT has been +one most of the time and there are some + + align:start position:0% +one most of the time and there are some + + + align:start position:0% +one most of the time and there are some +recent progress will discuss those + + align:start position:0% + + + + align:start position:0% + +progresses okay this is a more + + align:start position:0% +progresses okay this is a more + + + align:start position:0% +progresses okay this is a more +traditional + + align:start position:0% +traditional + + + align:start position:0% +traditional +material uh like I said this + + align:start position:0% + + + + align:start position:0% + +Tye and P Tye + + align:start position:0% +Tye and P Tye + + + align:start position:0% +Tye and P Tye +materials and SC is newer material so + + align:start position:0% +materials and SC is newer material so + + + align:start position:0% +materials and SC is newer material so +the uh commercial is + + align:start position:0% +the uh commercial is + + + align:start position:0% +the uh commercial is +Bid right bid go to periodic table I I + + align:start position:0% +Bid right bid go to periodic table I I + + + align:start position:0% +Bid right bid go to periodic table I I +can't remember all this positions every + + align:start position:0% +can't remember all this positions every + + + align:start position:0% +can't remember all this positions every +time I'm sit in my office look at + + align:start position:0% +time I'm sit in my office look at + + + align:start position:0% +time I'm sit in my office look at +periodic table but this a heavy that's + + align:start position:0% +periodic table but this a heavy that's + + + align:start position:0% +periodic table but this a heavy that's +so dismus colorum heavy elements and why + + align:start position:0% +so dismus colorum heavy elements and why + + + align:start position:0% +so dismus colorum heavy elements and why +uh we want heavy elements in this case + + align:start position:0% +uh we want heavy elements in this case + + + align:start position:0% +uh we want heavy elements in this case +why why it's good so you look at it as + + align:start position:0% +why why it's good so you look at it as + + + align:start position:0% +why why it's good so you look at it as +the uh it becomes heavier the bank Gap + + align:start position:0% +the uh it becomes heavier the bank Gap + + + align:start position:0% +the uh it becomes heavier the bank Gap +decreases here this is the bank Gap the + + align:start position:0% +decreases here this is the bank Gap the + + + align:start position:0% +decreases here this is the bank Gap the +bank Gap decrease uh it's typically + + align:start position:0% +bank Gap decrease uh it's typically + + + align:start position:0% +bank Gap decrease uh it's typically +about you need for the bank Gap versus + + align:start position:0% +about you need for the bank Gap versus + + + align:start position:0% +about you need for the bank Gap versus +temperature range around 10 KT okay 10 + + align:start position:0% +temperature range around 10 KT okay 10 + + + align:start position:0% +temperature range around 10 KT okay 10 +times KBT KT so at room temperature the + + align:start position:0% +times KBT KT so at room temperature the + + + align:start position:0% +times KBT KT so at room temperature the +KT is 26 M electron volts so 10 is + + align:start position:0% +KT is 26 M electron volts so 10 is + + + align:start position:0% +KT is 26 M electron volts so 10 is +a26 turns out the VIS ter back Gap is + + align:start position:0% +a26 turns out the VIS ter back Gap is + + + align:start position:0% +a26 turns out the VIS ter back Gap is +about + + align:start position:0% +about + + + align:start position:0% +about +.15 uh uh range so uh you go to uh see + + align:start position:0% +.15 uh uh range so uh you go to uh see + + + align:start position:0% +.15 uh uh range so uh you go to uh see +heavier material your bank Gap + + align:start position:0% +heavier material your bank Gap + + + align:start position:0% +heavier material your bank Gap +decreases and uh now you think about + + align:start position:0% +decreases and uh now you think about + + + align:start position:0% +decreases and uh now you think about +thermal + + align:start position:0% +thermal + + + align:start position:0% +thermal +conductivity uh recall that when I say + + align:start position:0% +conductivity uh recall that when I say + + + align:start position:0% +conductivity uh recall that when I say +the vibrational frequency right + + align:start position:0% +the vibrational frequency right + + + align:start position:0% +the vibrational frequency right +vibrational frequency is spring constant + + align:start position:0% +vibrational frequency is spring constant + + + align:start position:0% +vibrational frequency is spring constant +divide the mass square root + + align:start position:0% +divide the mass square root + + + align:start position:0% +divide the mass square root +so h mass you got uh the lower + + align:start position:0% +so h mass you got uh the lower + + + align:start position:0% +so h mass you got uh the lower +vibrational frequency lower vibrational + + align:start position:0% +vibrational frequency lower vibrational + + + align:start position:0% +vibrational frequency lower vibrational +frequency you look at the group velocity + + align:start position:0% +frequency you look at the group velocity + + + align:start position:0% +frequency you look at the group velocity +it travels slower so the fall on that + + align:start position:0% +it travels slower so the fall on that + + + align:start position:0% +it travels slower so the fall on that +waves go slow more slowly than lighter + + align:start position:0% +waves go slow more slowly than lighter + + + align:start position:0% +waves go slow more slowly than lighter +ATS so that's why the thermal + + align:start position:0% +ATS so that's why the thermal + + + align:start position:0% +ATS so that's why the thermal +conductivity uh is lower when you go to + + align:start position:0% +conductivity uh is lower when you go to + + + align:start position:0% +conductivity uh is lower when you go to +heavier materials so B ter right uh has + + align:start position:0% +heavier materials so B ter right uh has + + + align:start position:0% +heavier materials so B ter right uh has +a very complicated unit this is really + + align:start position:0% +a very complicated unit this is really + + + align:start position:0% +a very complicated unit this is really +in in terms of full periodicity when you + + align:start position:0% +in in terms of full periodicity when you + + + align:start position:0% +in in terms of full periodicity when you +consider a + + align:start position:0% +consider a + + + align:start position:0% +consider a +hexagonal unic cell is really uh 30.7 + + align:start position:0% +hexagonal unic cell is really uh 30.7 + + + align:start position:0% +hexagonal unic cell is really uh 30.7 +Armstrong many atoms here and uh uh it's + + align:start position:0% +Armstrong many atoms here and uh uh it's + + + align:start position:0% +Armstrong many atoms here and uh uh it's +it's interesting this is where when you + + align:start position:0% +it's interesting this is where when you + + + align:start position:0% +it's interesting this is where when you +really want to understand the material + + align:start position:0% +really want to understand the material + + + align:start position:0% +really want to understand the material +so uh it's a tum BM tum so layer + + align:start position:0% +so uh it's a tum BM tum so layer + + + align:start position:0% +so uh it's a tum BM tum so layer +structure right and this is the tum this + + align:start position:0% +structure right and this is the tum this + + + align:start position:0% +structure right and this is the tum this +is bmus to + + align:start position:0% +is bmus to + + + align:start position:0% +is bmus to +and the in between the layers you got + + align:start position:0% +and the in between the layers you got + + + align:start position:0% +and the in between the layers you got +you see here is T this are one bonding + + align:start position:0% +you see here is T this are one bonding + + + align:start position:0% +you see here is T this are one bonding +and here is more mixture of coent and + + align:start position:0% +and here is more mixture of coent and + + + align:start position:0% +and here is more mixture of coent and +ionic bonding uh and there lot of study + + align:start position:0% +ionic bonding uh and there lot of study + + + align:start position:0% +ionic bonding uh and there lot of study +people looking at which layer is + + align:start position:0% +people looking at which layer is + + + align:start position:0% +people looking at which layer is +conducting electron which layer is + + align:start position:0% +conducting electron which layer is + + + align:start position:0% +conducting electron which layer is +conducting hole and uh uh it's a really + + align:start position:0% +conducting hole and uh uh it's a really + + + align:start position:0% +conducting hole and uh uh it's a really +if you we're still working on + + align:start position:0% +if you we're still working on + + + align:start position:0% +if you we're still working on +buide and it's important to understand + + align:start position:0% +buide and it's important to understand + + + align:start position:0% +buide and it's important to understand +those details because people have been + + align:start position:0% +those details because people have been + + + align:start position:0% +those details because people have been +working this many years you want to do + + align:start position:0% +working this many years you want to do + + + align:start position:0% +working this many years you want to do +something you need to look at detail + + align:start position:0% +something you need to look at detail + + + align:start position:0% +something you need to look at detail +where are the which are the layers that + + align:start position:0% +where are the which are the layers that + + + align:start position:0% +where are the which are the layers that +electron can you think about something + + align:start position:0% +electron can you think about something + + + align:start position:0% +electron can you think about something +that you can for example still get the + + align:start position:0% +that you can for example still get the + + + align:start position:0% +that you can for example still get the +electron transer well in this layer but + + align:start position:0% +electron transer well in this layer but + + + align:start position:0% +electron transer well in this layer but +screw up the Fon kill the Fon + + align:start position:0% +screw up the Fon kill the Fon + + + align:start position:0% +screw up the Fon kill the Fon +propagation in the materials so uh + + align:start position:0% +propagation in the materials so uh + + + align:start position:0% +propagation in the materials so uh +people calculate the B structure I'm not + + align:start position:0% +people calculate the B structure I'm not + + + align:start position:0% +people calculate the B structure I'm not +going to detail this is a really uh how + + align:start position:0% +going to detail this is a really uh how + + + align:start position:0% +going to detail this is a really uh how +you do this uh the span structure + + align:start position:0% +you do this uh the span structure + + + align:start position:0% +you do this uh the span structure +calculation is also relative standard + + align:start position:0% +calculation is also relative standard + + + align:start position:0% +calculation is also relative standard +you do density function Theory + + align:start position:0% +you do density function Theory + + + align:start position:0% +you do density function Theory +calculation and uh this is a pure + + align:start position:0% +calculation and uh this is a pure + + + align:start position:0% +calculation and uh this is a pure +business turn right uh uh uh if you just + + align:start position:0% +business turn right uh uh uh if you just + + + align:start position:0% +business turn right uh uh uh if you just +do pure business turn right the Z the + + align:start position:0% +do pure business turn right the Z the + + + align:start position:0% +do pure business turn right the Z the +best is + + align:start position:0% +best is + + + align:start position:0% +best is +about6 okay and how you get one is + + align:start position:0% +about6 okay and how you get one is + + + align:start position:0% +about6 okay and how you get one is +really by alloying alloying you so you + + align:start position:0% +really by alloying alloying you so you + + + align:start position:0% +really by alloying alloying you so you +can further reduce Thal conductivity by + + align:start position:0% +can further reduce Thal conductivity by + + + align:start position:0% +can further reduce Thal conductivity by +allo so B ter is a Compound + + align:start position:0% +allo so B ter is a Compound + + + align:start position:0% +allo so B ter is a Compound +Semiconductor and they look at the same + + align:start position:0% +Semiconductor and they look at the same + + + align:start position:0% +Semiconductor and they look at the same +column of the periodic table when we are + + align:start position:0% +column of the periodic table when we are + + + align:start position:0% +column of the periodic table when we are +thinking Al is same column periodic + + align:start position:0% +thinking Al is same column periodic + + + align:start position:0% +thinking Al is same column periodic +table and you substitute for example + + align:start position:0% +table and you substitute for example + + + align:start position:0% +table and you substitute for example +buus by + + align:start position:0% +buus by + + + align:start position:0% +buus by +antimony and that way you could reduce + + align:start position:0% +antimony and that way you could reduce + + + align:start position:0% +antimony and that way you could reduce +thermal + + align:start position:0% +thermal + + + align:start position:0% +thermal +conductivity and the best example of + + align:start position:0% +conductivity and the best example of + + + align:start position:0% +conductivity and the best example of +allo reduced th + + align:start position:0% +allo reduced th + + + align:start position:0% +allo reduced th +conductivity is + + align:start position:0% +conductivity is + + + align:start position:0% +conductivity is +Sy okay and the SEC manual uh this is a + + align:start position:0% +Sy okay and the SEC manual uh this is a + + + align:start position:0% +Sy okay and the SEC manual uh this is a +another Thal conductivity unit this is + + align:start position:0% +another Thal conductivity unit this is + + + align:start position:0% +another Thal conductivity unit this is +the inverse thermal + + align:start position:0% +the inverse thermal + + + align:start position:0% +the inverse thermal +conductivity uh uh unit so uh here is + + align:start position:0% +conductivity uh uh unit so uh here is + + + align:start position:0% +conductivity uh uh unit so uh here is +cicon very conductive the theral + + align:start position:0% +cicon very conductive the theral + + + align:start position:0% +cicon very conductive the theral +conductivity of silicon is about + + align:start position:0% +conductivity of silicon is about + + + align:start position:0% +conductivity of silicon is about +150 wat per meter per + + align:start position:0% +150 wat per meter per + + + align:start position:0% +150 wat per meter per +K and the geranium is also very + + align:start position:0% +K and the geranium is also very + + + align:start position:0% +K and the geranium is also very +conductive about 60 wat per meter per K + + align:start position:0% +conductive about 60 wat per meter per K + + + align:start position:0% +conductive about 60 wat per meter per K +okay now you mix a little bit you can + + align:start position:0% +okay now you mix a little bit you can + + + align:start position:0% +okay now you mix a little bit you can +see this is not a linear curve right you + + align:start position:0% +see this is not a linear curve right you + + + align:start position:0% +see this is not a linear curve right you +mix a little bit silicon with Germania + + align:start position:0% +mix a little bit silicon with Germania + + + align:start position:0% +mix a little bit silicon with Germania +your thermal conductivity drop + + align:start position:0% +your thermal conductivity drop + + + align:start position:0% +your thermal conductivity drop +sharply and the lowest thermal + + align:start position:0% +sharply and the lowest thermal + + + align:start position:0% +sharply and the lowest thermal +conductivity here your un state is about + + align:start position:0% +conductivity here your un state is about + + + align:start position:0% +conductivity here your un state is about +67 wat met kin so you drop from 100 to + + align:start position:0% +67 wat met kin so you drop from 100 to + + + align:start position:0% +67 wat met kin so you drop from 100 to +67 by alloy and this is because again if + + align:start position:0% +67 by alloy and this is because again if + + + align:start position:0% +67 by alloy and this is because again if +you think about it you have Atomic chain + + align:start position:0% +you think about it you have Atomic chain + + + align:start position:0% +you think about it you have Atomic chain +right first you do you can try with a + + align:start position:0% +right first you do you can try with a + + + align:start position:0% +right first you do you can try with a +pure atom Ste second you you MX up the + + align:start position:0% +pure atom Ste second you you MX up the + + + align:start position:0% +pure atom Ste second you you MX up the +atom ticity the wave becomes frustrated + + align:start position:0% +atom ticity the wave becomes frustrated + + + align:start position:0% +atom ticity the wave becomes frustrated +and so the theral + + align:start position:0% +and so the theral + + + align:start position:0% +and so the theral +conductivity uh will drop so this is one + + align:start position:0% +conductivity uh will drop so this is one + + + align:start position:0% +conductivity uh will drop so this is one +way of scattering and that's the all th + + align:start position:0% +way of scattering and that's the all th + + + align:start position:0% +way of scattering and that's the all th +electric + + align:start position:0% +electric + + + align:start position:0% +electric +materials that are made of Alloys and uh + + align:start position:0% +materials that are made of Alloys and uh + + + align:start position:0% +materials that are made of Alloys and uh +uh the typical thinking of the alloy is + + align:start position:0% +uh the typical thinking of the alloy is + + + align:start position:0% +uh the typical thinking of the alloy is +in terms of scn create additional + + align:start position:0% +in terms of scn create additional + + + align:start position:0% +in terms of scn create additional +statter and you can see here this is a + + align:start position:0% +statter and you can see here this is a + + + align:start position:0% +statter and you can see here this is a +really statter relation + + align:start position:0% +really statter relation + + + align:start position:0% +really statter relation +what is really scanner you go outside in + + align:start position:0% +what is really scanner you go outside in + + + align:start position:0% +what is really scanner you go outside in +sunny day you see blue + + align:start position:0% +sunny day you see blue + + + align:start position:0% +sunny day you see blue +skies and the blue sky is the blue light + + align:start position:0% +skies and the blue sky is the blue light + + + align:start position:0% +skies and the blue sky is the blue light +get + + align:start position:0% +get + + + align:start position:0% +get +scattered and high frequency blue light + + align:start position:0% +scattered and high frequency blue light + + + align:start position:0% +scattered and high frequency blue light +compared to red right solar radiation + + align:start position:0% +compared to red right solar radiation + + + align:start position:0% +compared to red right solar radiation +The High Frequency scatter more so here + + align:start position:0% +The High Frequency scatter more so here + + + align:start position:0% +The High Frequency scatter more so here +is the really scatter regime that's + + align:start position:0% +is the really scatter regime that's + + + align:start position:0% +is the really scatter regime that's +that's really scatter high frequency and + + align:start position:0% +that's really scatter high frequency and + + + align:start position:0% +that's really scatter high frequency and +the some wave is typical as people model + + align:start position:0% +the some wave is typical as people model + + + align:start position:0% +the some wave is typical as people model +uh high frequency it's a inverse time so + + align:start position:0% +uh high frequency it's a inverse time so + + + align:start position:0% +uh high frequency it's a inverse time so +scatter time relaxation time is shorter + + align:start position:0% +scatter time relaxation time is shorter + + + align:start position:0% +scatter time relaxation time is shorter +so that's really scatter and uh uh then + + align:start position:0% +so that's really scatter and uh uh then + + + align:start position:0% +so that's really scatter and uh uh then +this depends on the mass contrast and + + align:start position:0% +this depends on the mass contrast and + + + align:start position:0% +this depends on the mass contrast and +also depends on lce uh parameter lce + + align:start position:0% +also depends on lce uh parameter lce + + + align:start position:0% +also depends on lce uh parameter lce +constant + + align:start position:0% +constant + + + align:start position:0% +constant +contast those series were done in the + + align:start position:0% +contast those series were done in the + + + align:start position:0% +contast those series were done in the +50s and in fact I have a lot of + + align:start position:0% +50s and in fact I have a lot of + + + align:start position:0% +50s and in fact I have a lot of +Suspicion whether they are truly valid + + align:start position:0% +Suspicion whether they are truly valid + + + align:start position:0% +Suspicion whether they are truly valid +or not and uh uh but say that's what + + align:start position:0% +or not and uh uh but say that's what + + + align:start position:0% +or not and uh uh but say that's what +people doing uh this is the just the + + align:start position:0% +people doing uh this is the just the + + + align:start position:0% +people doing uh this is the just the +Curr St most + + align:start position:0% +Curr St most + + + align:start position:0% +Curr St most +of and the the problem is you go to + + align:start position:0% +of and the the problem is you go to + + + align:start position:0% +of and the the problem is you go to +think about theral conductivity I show + + align:start position:0% +think about theral conductivity I show + + + align:start position:0% +think about theral conductivity I show +payal 13 c v GMA + + align:start position:0% +payal 13 c v GMA + + + align:start position:0% +payal 13 c v GMA +integration and integration is very + + align:start position:0% +integration and integration is very + + + align:start position:0% +integration and integration is very +forgiven okay in the sense if you make + + align:start position:0% +forgiven okay in the sense if you make + + + align:start position:0% +forgiven okay in the sense if you make +the error one place you make up the + + align:start position:0% +the error one place you make up the + + + align:start position:0% +the error one place you make up the +other place and when you don't have + + align:start position:0% +other place and when you don't have + + + align:start position:0% +other place and when you don't have +exact uh Theory there and you got a lot + + align:start position:0% +exact uh Theory there and you got a lot + + + align:start position:0% +exact uh Theory there and you got a lot +of feeding parameter and that + + align:start position:0% +of feeding parameter and that + + + align:start position:0% +of feeding parameter and that +integration can help you publish your + + align:start position:0% +integration can help you publish your + + + align:start position:0% +integration can help you publish your +paper okay + + align:start position:0% +paper okay + + + align:start position:0% +paper okay +but uh the details very often are + + align:start position:0% +but uh the details very often are + + + align:start position:0% +but uh the details very often are +amazing okay like I said uh this is a + + align:start position:0% +amazing okay like I said uh this is a + + + align:start position:0% +amazing okay like I said uh this is a +typically that's how people uh make the + + align:start position:0% +typically that's how people uh make the + + + align:start position:0% +typically that's how people uh make the +material dismus in P5 dismus antimony + + align:start position:0% +material dismus in P5 dismus antimony + + + align:start position:0% +material dismus in P5 dismus antimony +and this x is about 33 + + align:start position:0% +and this x is about 33 + + + align:start position:0% +and this x is about 33 +to.5 and then the end type material + + align:start position:0% +to.5 and then the end type material + + + align:start position:0% +to.5 and then the end type material +dismus anony and with + + align:start position:0% +dismus anony and with + + + align:start position:0% +dismus anony and with +senum and if any of you actually are uh + + align:start position:0% +senum and if any of you actually are uh + + + align:start position:0% +senum and if any of you actually are uh +from physics Department uh you probably + + align:start position:0% +from physics Department uh you probably + + + align:start position:0% +from physics Department uh you probably +went to I remember a few weeks ago there + + align:start position:0% +went to I remember a few weeks ago there + + + align:start position:0% +went to I remember a few weeks ago there +was a seminar on topological conductor + + align:start position:0% +was a seminar on topological conductor + + + align:start position:0% +was a seminar on topological conductor +turns out that this material now it's + + align:start position:0% +turns out that this material now it's + + + align:start position:0% +turns out that this material now it's +very hard in the physics people are + + align:start position:0% +very hard in the physics people are + + + align:start position:0% +very hard in the physics people are +looking at Anon turn right and it's + + align:start position:0% +looking at Anon turn right and it's + + + align:start position:0% +looking at Anon turn right and it's +topological conductor uh so very hot to + + align:start position:0% +topological conductor uh so very hot to + + + align:start position:0% +topological conductor uh so very hot to +clear but see uh we don't know whether + + align:start position:0% +clear but see uh we don't know whether + + + align:start position:0% +clear but see uh we don't know whether +that has any implication of thermo + + align:start position:0% +that has any implication of thermo + + + align:start position:0% +that has any implication of thermo +electrics or + + align:start position:0% +electrics or + + + align:start position:0% +electrics or +not and dopin you can uh always add + + align:start position:0% +not and dopin you can uh always add + + + align:start position:0% +not and dopin you can uh always add +other materials as dopin but say uh here + + align:start position:0% +other materials as dopin but say uh here + + + align:start position:0% +other materials as dopin but say uh here +typically is by Def effect the soal anti + + align:start position:0% +typically is by Def effect the soal anti + + + align:start position:0% +typically is by Def effect the soal anti +side so if you look at it it's possible + + align:start position:0% +side so if you look at it it's possible + + + align:start position:0% +side so if you look at it it's possible +that buiness go to torum side and this + + align:start position:0% +that buiness go to torum side and this + + + align:start position:0% +that buiness go to torum side and this +is a particularly because bmus and torum + + align:start position:0% +is a particularly because bmus and torum + + + align:start position:0% +is a particularly because bmus and torum +there are soall Char say uh electro + + align:start position:0% +there are soall Char say uh electro + + + align:start position:0% +there are soall Char say uh electro +negativity is very similar so they can + + align:start position:0% +negativity is very similar so they can + + + align:start position:0% +negativity is very similar so they can +uh uh the when they exchange positions + + align:start position:0% +uh uh the when they exchange positions + + + align:start position:0% +uh uh the when they exchange positions +uh uh the uh the uh disturbance PR is + + align:start position:0% +uh uh the uh the uh disturbance PR is + + + align:start position:0% +uh uh the uh the uh disturbance PR is +small but the number of charge is + + align:start position:0% +small but the number of charge is + + + align:start position:0% +small but the number of charge is +different so that cre either F or + + align:start position:0% + + + + align:start position:0% + +electrons okay so now we're moving to so + + align:start position:0% +electrons okay so now we're moving to so + + + align:start position:0% +electrons okay so now we're moving to so +that's traditional material we're now + + align:start position:0% +that's traditional material we're now + + + align:start position:0% +that's traditional material we're now +moving to more uh current materials + + align:start position:0% +moving to more uh current materials + + + align:start position:0% +moving to more uh current materials +people are + + align:start position:0% +people are + + + align:start position:0% +people are +talking uh this is a uh uh oxide um it's + + align:start position:0% +talking uh this is a uh uh oxide um it's + + + align:start position:0% +talking uh this is a uh uh oxide um it's +sodium cobal uh oxide and uh uh this + + align:start position:0% +sodium cobal uh oxide and uh uh this + + + align:start position:0% +sodium cobal uh oxide and uh uh this +were originally started in Japan terak + + align:start position:0% +were originally started in Japan terak + + + align:start position:0% +were originally started in Japan terak +more contribution to this and uh turns + + align:start position:0% +more contribution to this and uh turns + + + align:start position:0% +more contribution to this and uh turns +out people are interested in oxide since + + align:start position:0% +out people are interested in oxide since + + + align:start position:0% +out people are interested in oxide since +1980s + + align:start position:0% + + + + align:start position:0% + +why that's because the high temperature + + align:start position:0% +why that's because the high temperature + + + align:start position:0% +why that's because the high temperature +superconductor was discovered out of + + align:start position:0% +superconductor was discovered out of + + + align:start position:0% +superconductor was discovered out of +oxide it's is + + align:start position:0% +oxide it's is + + + align:start position:0% +oxide it's is +surprising yd you s copper oxygen + + align:start position:0% +surprising yd you s copper oxygen + + + align:start position:0% +surprising yd you s copper oxygen +and that got lower price right see so uh + + align:start position:0% +and that got lower price right see so uh + + + align:start position:0% +and that got lower price right see so uh +the transitional temperature now in this + + align:start position:0% +the transitional temperature now in this + + + align:start position:0% +the transitional temperature now in this +High tempure super conductor uh has + + align:start position:0% +High tempure super conductor uh has + + + align:start position:0% +High tempure super conductor uh has +reached probably around 130 K + + align:start position:0% +reached probably around 130 K + + + align:start position:0% +reached probably around 130 K +140 uh but say uh super conductor itself + + align:start position:0% +140 uh but say uh super conductor itself + + + align:start position:0% +140 uh but say uh super conductor itself +is not interesting for + + align:start position:0% +is not interesting for + + + align:start position:0% +is not interesting for +thermoelectrics why this is because + + align:start position:0% +thermoelectrics why this is because + + + align:start position:0% +thermoelectrics why this is because +there's only one common state so the + + align:start position:0% +there's only one common state so the + + + align:start position:0% +there's only one common state so the +entropy is is zero log of quum state + + align:start position:0% +entropy is is zero log of quum state + + + align:start position:0% +entropy is is zero log of quum state +right that's the for man relation uh uh + + align:start position:0% +right that's the for man relation uh uh + + + align:start position:0% +right that's the for man relation uh uh +entropy carried by say is a l state so + + align:start position:0% +entropy carried by say is a l state so + + + align:start position:0% +entropy carried by say is a l state so +super conductor is not interesting but + + align:start position:0% +super conductor is not interesting but + + + align:start position:0% +super conductor is not interesting but +this one is lot of super conductor and + + align:start position:0% +this one is lot of super conductor and + + + align:start position:0% +this one is lot of super conductor and +uh people have achieve about ZT for one + + align:start position:0% +uh people have achieve about ZT for one + + + align:start position:0% +uh people have achieve about ZT for one +at I think this is around 800 de CS so + + align:start position:0% +at I think this is around 800 de CS so + + + align:start position:0% +at I think this is around 800 de CS so +it's a high temperature + + align:start position:0% + + + + align:start position:0% + +application uh half poer uh I mentioned + + align:start position:0% +application uh half poer uh I mentioned + + + align:start position:0% +application uh half poer uh I mentioned +this material uh + + align:start position:0% +this material uh + + + align:start position:0% +this material uh +because if you go to Japan I talk a lot + + align:start position:0% +because if you go to Japan I talk a lot + + + align:start position:0% +because if you go to Japan I talk a lot +to uh uh Japan uh C ELC guys and also + + align:start position:0% +to uh uh Japan uh C ELC guys and also + + + align:start position:0% +to uh uh Japan uh C ELC guys and also +from a + + align:start position:0% +from a + + + align:start position:0% +from a +company uh whenever you work on you look + + align:start position:0% +company uh whenever you work on you look + + + align:start position:0% +company uh whenever you work on you look +at the disos ter uh they they whereare + + align:start position:0% +at the disos ter uh they they whereare + + + align:start position:0% +at the disos ter uh they they whereare +Japan is very sensitive this + + align:start position:0% +Japan is very sensitive this + + + align:start position:0% +Japan is very sensitive this +because uh they have limited amount of + + align:start position:0% +because uh they have limited amount of + + + align:start position:0% +because uh they have limited amount of +materials right small country and the + + align:start position:0% +materials right small country and the + + + align:start position:0% +materials right small country and the +resources very limited so they don't + + align:start position:0% +resources very limited so they don't + + + align:start position:0% +resources very limited so they don't +want they always say can you make out of + + align:start position:0% +want they always say can you make out of + + + align:start position:0% +want they always say can you make out of +this abond material what are the abond + + align:start position:0% +this abond material what are the abond + + + align:start position:0% +this abond material what are the abond +material + + align:start position:0% +material + + + align:start position:0% +material +City and aluminum so those type of + + align:start position:0% +City and aluminum so those type of + + + align:start position:0% +City and aluminum so those type of +materials and uh uh so this is one + + align:start position:0% +materials and uh uh so this is one + + + align:start position:0% +materials and uh uh so this is one +example where the material is called + + align:start position:0% +example where the material is called + + + align:start position:0% +example where the material is called +abundant + + align:start position:0% +abundant + + + align:start position:0% +abundant +ni uh uh kin and tanium and it has + + align:start position:0% +ni uh uh kin and tanium and it has + + + align:start position:0% +ni uh uh kin and tanium and it has +reached a reasonable uh fig of marage + + align:start position:0% +reached a reasonable uh fig of marage + + + align:start position:0% +reached a reasonable uh fig of marage +and this is where for example you look + + align:start position:0% +and this is where for example you look + + + align:start position:0% +and this is where for example you look +at even with this biger merage C cond is + + align:start position:0% +at even with this biger merage C cond is + + + align:start position:0% +at even with this biger merage C cond is +still very high why is still very high + + align:start position:0% +still very high why is still very high + + + align:start position:0% +still very high why is still very high +why I say it's very high because you + + align:start position:0% +why I say it's very high because you + + + align:start position:0% +why I say it's very high because you +always think of BU St right that's a + + align:start position:0% +always think of BU St right that's a + + + align:start position:0% +always think of BU St right that's a +good number to remember Cal conductivity + + align:start position:0% +good number to remember Cal conductivity + + + align:start position:0% +good number to remember Cal conductivity +is about one or 1.5 C is 100 microwatt + + align:start position:0% +is about one or 1.5 C is 100 microwatt + + + align:start position:0% +is about one or 1.5 C is 100 microwatt +per celvin and + + align:start position:0% +per celvin and + + + align:start position:0% +per celvin and +electric so if you look at this the + + align:start position:0% +electric so if you look at this the + + + align:start position:0% +electric so if you look at this the +ctivity is in the denominator and they + + align:start position:0% +ctivity is in the denominator and they + + + align:start position:0% +ctivity is in the denominator and they +get this good uh ZT that means electron + + align:start position:0% +get this good uh ZT that means electron + + + align:start position:0% +get this good uh ZT that means electron +is really good right s sare Sigma that's + + align:start position:0% +is really good right s sare Sigma that's + + + align:start position:0% +is really good right s sare Sigma that's +the power factor is pretty good can you + + align:start position:0% +the power factor is pretty good can you + + + align:start position:0% +the power factor is pretty good can you +kill this guy can you kill it thermal + + align:start position:0% +kill this guy can you kill it thermal + + + align:start position:0% +kill this guy can you kill it thermal +conductivity reduce it how + + align:start position:0% +conductivity reduce it how + + + align:start position:0% +conductivity reduce it how +can you reduce the F part you don't just + + align:start position:0% +can you reduce the F part you don't just + + + align:start position:0% +can you reduce the F part you don't just +want to reduce because the electronic + + align:start position:0% +want to reduce because the electronic + + + align:start position:0% +want to reduce because the electronic +also part of the + + align:start position:0% + + + + align:start position:0% + +Z okay so uh people now looking into if + + align:start position:0% +Z okay so uh people now looking into if + + + align:start position:0% +Z okay so uh people now looking into if +you look at the P materials right uh + + align:start position:0% +you look at the P materials right uh + + + align:start position:0% +you look at the P materials right uh +it's typically bu ter let ter manual + + align:start position:0% +it's typically bu ter let ter manual + + + align:start position:0% +it's typically bu ter let ter manual +those are simple structures simple + + align:start position:0% +those are simple structures simple + + + align:start position:0% +those are simple structures simple +compounds Two element binary + + align:start position:0% +compounds Two element binary + + + align:start position:0% +compounds Two element binary +right and now people are looking going + + align:start position:0% +right and now people are looking going + + + align:start position:0% +right and now people are looking going +more into more complex + + align:start position:0% +more into more complex + + + align:start position:0% +more into more complex +structures and the why complex + + align:start position:0% +structures and the why complex + + + align:start position:0% +structures and the why complex +structure yeah from Thal connectivity + + align:start position:0% +structure yeah from Thal connectivity + + + align:start position:0% +structure yeah from Thal connectivity +point of view there is a good reason + + align:start position:0% +point of view there is a good reason + + + align:start position:0% +point of view there is a good reason +there uh uh this is a few lecture back I + + align:start position:0% +there uh uh this is a few lecture back I + + + align:start position:0% +there uh uh this is a few lecture back I +was talking about the mes right uh in + + align:start position:0% +was talking about the mes right uh in + + + align:start position:0% +was talking about the mes right uh in +terms of op forong acoustic forong op + + align:start position:0% +terms of op forong acoustic forong op + + + align:start position:0% +terms of op forong acoustic forong op +Fon is very flat and acoustic Fon is + + align:start position:0% +Fon is very flat and acoustic Fon is + + + align:start position:0% +Fon is very flat and acoustic Fon is +really the one that carries Heat + + align:start position:0% +really the one that carries Heat + + + align:start position:0% +really the one that carries Heat +so when you got a lot of atem in the + + align:start position:0% +so when you got a lot of atem in the + + + align:start position:0% +so when you got a lot of atem in the +Unis + + align:start position:0% +Unis + + + align:start position:0% +Unis +cell you have lot of op branches so + + align:start position:0% +cell you have lot of op branches so + + + align:start position:0% +cell you have lot of op branches so +those out brand don't carry much GE so + + align:start position:0% +those out brand don't carry much GE so + + + align:start position:0% +those out brand don't carry much GE so +the uh that's the more complex Crystal + + align:start position:0% +the uh that's the more complex Crystal + + + align:start position:0% +the uh that's the more complex Crystal +typically the lower is their C + + align:start position:0% +typically the lower is their C + + + align:start position:0% +typically the lower is their C +connectivity and that's only a very + + align:start position:0% +connectivity and that's only a very + + + align:start position:0% +connectivity and that's only a very +simple uh handen uh uh way of saying and + + align:start position:0% +simple uh handen uh uh way of saying and + + + align:start position:0% +simple uh handen uh uh way of saying and +of course you can say some of this + + align:start position:0% +of course you can say some of this + + + align:start position:0% +of course you can say some of this +material have really low of conductivity + + align:start position:0% +material have really low of conductivity + + + align:start position:0% +material have really low of conductivity +bu turn right is is here right and this + + align:start position:0% +bu turn right is is here right and this + + + align:start position:0% +bu turn right is is here right and this +like want to find out this Z + + align:start position:0% +like want to find out this Z + + + align:start position:0% +like want to find out this Z +zinc zinc is a b if you can make zinc + + align:start position:0% +zinc zinc is a b if you can make zinc + + + align:start position:0% +zinc zinc is a b if you can make zinc +zinc zinc is a good one if you can make + + align:start position:0% +zinc zinc is a good one if you can make + + + align:start position:0% +zinc zinc is a good one if you can make +the work right uh and it has very low + + align:start position:0% +the work right uh and it has very low + + + align:start position:0% +the work right uh and it has very low +Thal conductivity and in fact + + align:start position:0% +Thal conductivity and in fact + + + align:start position:0% +Thal conductivity and in fact +zinc electric F mer now has reached I + + align:start position:0% +zinc electric F mer now has reached I + + + align:start position:0% +zinc electric F mer now has reached I +think it's about 1.4 + + align:start position:0% +think it's about 1.4 + + + align:start position:0% +think it's about 1.4 +um pretty good except there are also + + align:start position:0% +um pretty good except there are also + + + align:start position:0% +um pretty good except there are also +issues material stability and when you + + align:start position:0% +issues material stability and when you + + + align:start position:0% +issues material stability and when you +heat up to high + + align:start position:0% +heat up to high + + + align:start position:0% +heat up to high +temperature zinc speed up I have seen + + align:start position:0% +temperature zinc speed up I have seen + + + align:start position:0% +temperature zinc speed up I have seen +pictures showing that the under tempure + + align:start position:0% +pictures showing that the under tempure + + + align:start position:0% +pictures showing that the under tempure +gradient is the material grew here okay + + align:start position:0% +gradient is the material grew here okay + + + align:start position:0% +gradient is the material grew here okay +the here are Z coming out so You' got a + + align:start position:0% +the here are Z coming out so You' got a + + + align:start position:0% +the here are Z coming out so You' got a +lot of material reliability issues also + + align:start position:0% +lot of material reliability issues also + + + align:start position:0% +lot of material reliability issues also +and uh uh so the uh but uh generally + + align:start position:0% +and uh uh so the uh but uh generally + + + align:start position:0% +and uh uh so the uh but uh generally +there are L people into a lot more + + align:start position:0% +there are L people into a lot more + + + align:start position:0% +there are L people into a lot more +complex structures Crystal + + align:start position:0% +complex structures Crystal + + + align:start position:0% +complex structures Crystal +structures and a broader much broader + + align:start position:0% +structures and a broader much broader + + + align:start position:0% +structures and a broader much broader +range of some electric materials I + + align:start position:0% +range of some electric materials I + + + align:start position:0% +range of some electric materials I +mentioned this already but now let's + + align:start position:0% +mentioned this already but now let's + + + align:start position:0% +mentioned this already but now let's +look at the ideas right uh which the + + align:start position:0% +look at the ideas right uh which the + + + align:start position:0% +look at the ideas right uh which the +complex structure and this is another + + align:start position:0% +complex structure and this is another + + + align:start position:0% +complex structure and this is another +idea uh that's really interesting + + align:start position:0% +idea uh that's really interesting + + + align:start position:0% +idea uh that's really interesting +because + + align:start position:0% +because + + + align:start position:0% +because +uh uh alloy if you think about silicon + + align:start position:0% +uh uh alloy if you think about silicon + + + align:start position:0% +uh uh alloy if you think about silicon +gum + + align:start position:0% +gum + + + align:start position:0% +gum +alloy and it's really geranium go to + + align:start position:0% +alloy and it's really geranium go to + + + align:start position:0% +alloy and it's really geranium go to +Silicon Atomic side so you can think + + align:start position:0% +Silicon Atomic side so you can think + + + align:start position:0% +Silicon Atomic side so you can think +about that as a substitution right so + + align:start position:0% +about that as a substitution right so + + + align:start position:0% +about that as a substitution right so +silicon germanium substitute silicon + + align:start position:0% +silicon germanium substitute silicon + + + align:start position:0% +silicon germanium substitute silicon +atom the L is the if you think about + + align:start position:0% +atom the L is the if you think about + + + align:start position:0% +atom the L is the if you think about +cube right and let's take a cry right + + align:start position:0% +cube right and let's take a cry right + + + align:start position:0% +cube right and let's take a cry right +think about Cube and silicon sits in the + + align:start position:0% +think about Cube and silicon sits in the + + + align:start position:0% +think about Cube and silicon sits in the +corner of the cube now you take out one + + align:start position:0% +corner of the cube now you take out one + + + align:start position:0% +corner of the cube now you take out one +of the corner you put a gtic and so the + + align:start position:0% +of the corner you put a gtic and so the + + + align:start position:0% +of the corner you put a gtic and so the +this is a uh substitutional uh type of I + + align:start position:0% +this is a uh substitutional uh type of I + + + align:start position:0% +this is a uh substitutional uh type of I +call + + align:start position:0% + + + + align:start position:0% + +that and Scar is a simple interesting + + align:start position:0% +that and Scar is a simple interesting + + + align:start position:0% +that and Scar is a simple interesting +material uh this is a SC Cal antim + + align:start position:0% +material uh this is a SC Cal antim + + + align:start position:0% +material uh this is a SC Cal antim +orium IR that type of + + align:start position:0% +orium IR that type of + + + align:start position:0% +orium IR that type of +structure and what's interesting is it + + align:start position:0% +structure and what's interesting is it + + + align:start position:0% +structure and what's interesting is it +has a very large Unis cell lot of atoms + + align:start position:0% +has a very large Unis cell lot of atoms + + + align:start position:0% +has a very large Unis cell lot of atoms +there and also in those unic cell so + + align:start position:0% +there and also in those unic cell so + + + align:start position:0% +there and also in those unic cell so +uh uh here we got two V so you can see + + align:start position:0% +uh uh here we got two V so you can see + + + align:start position:0% +uh uh here we got two V so you can see +this each is a square right but in uh + + align:start position:0% +this each is a square right but in uh + + + align:start position:0% +this each is a square right but in uh +this eight uh how many we have eight + + align:start position:0% +this eight uh how many we have eight + + + align:start position:0% +this eight uh how many we have eight +cubes six of the square has a atoms + + align:start position:0% +cubes six of the square has a atoms + + + align:start position:0% +cubes six of the square has a atoms +inside two of them don't have anything + + align:start position:0% +inside two of them don't have anything + + + align:start position:0% +inside two of them don't have anything +inside so there is a open space + + align:start position:0% +inside so there is a open space + + + align:start position:0% +inside so there is a open space +here uh the open space give you + + align:start position:0% +here uh the open space give you + + + align:start position:0% +here uh the open space give you +opportunity let's put another at + + align:start position:0% +opportunity let's put another at + + + align:start position:0% +opportunity let's put another at +there another this atom has a very + + align:start position:0% +there another this atom has a very + + + align:start position:0% +there another this atom has a very +different characteristic from the host + + align:start position:0% +different characteristic from the host + + + align:start position:0% +different characteristic from the host +atom cob UL so the idea is like a r + + align:start position:0% +atom cob UL so the idea is like a r + + + align:start position:0% +atom cob UL so the idea is like a r +slate you put the atom the r wrong and + + align:start position:0% +slate you put the atom the r wrong and + + + align:start position:0% +slate you put the atom the r wrong and +this rine will disturb the normally + + align:start position:0% +this rine will disturb the normally + + + align:start position:0% +this rine will disturb the normally +periodical L waves in the surrounding + + align:start position:0% +periodical L waves in the surrounding + + + align:start position:0% +periodical L waves in the surrounding +material surrounding the the lat itself + + align:start position:0% +material surrounding the the lat itself + + + align:start position:0% +material surrounding the the lat itself +so that was called fullon r + + align:start position:0% +so that was called fullon r + + + align:start position:0% +so that was called fullon r +and + + align:start position:0% +and + + + align:start position:0% +and +uh next one it's example + + align:start position:0% +uh next one it's example + + + align:start position:0% +uh next one it's example +of you can see + + align:start position:0% +of you can see + + + align:start position:0% +of you can see +C and you feel this with other rular Lum + + align:start position:0% +C and you feel this with other rular Lum + + + align:start position:0% +C and you feel this with other rular Lum +and people try it many different way + + align:start position:0% +and people try it many different way + + + align:start position:0% +and people try it many different way +this is a steel I said uh I was in the + + align:start position:0% +this is a steel I said uh I was in the + + + align:start position:0% +this is a steel I said uh I was in the +meeting last week and people are still + + align:start position:0% +meeting last week and people are still + + + align:start position:0% +meeting last week and people are still +putting first with one r one atom one + + align:start position:0% +putting first with one r one atom one + + + align:start position:0% +putting first with one r one atom one +type of atom now people gotone to three + + align:start position:0% +type of atom now people gotone to three + + + align:start position:0% +type of atom now people gotone to three +rackers well the hope is each rler have + + align:start position:0% +rackers well the hope is each rler have + + + align:start position:0% +rackers well the hope is each rler have +its own rling + + align:start position:0% +its own rling + + + align:start position:0% +its own rling +frequency and you kill the whole uh + + align:start position:0% +frequency and you kill the whole uh + + + align:start position:0% +frequency and you kill the whole uh +acoustic frequency of the whole uh LS + + align:start position:0% +acoustic frequency of the whole uh LS + + + align:start position:0% +acoustic frequency of the whole uh LS +waves so uh this is a clearly a very + + align:start position:0% +waves so uh this is a clearly a very + + + align:start position:0% +waves so uh this is a clearly a very +dramatic decrease in the latest thermal + + align:start position:0% +dramatic decrease in the latest thermal + + + align:start position:0% +dramatic decrease in the latest thermal +connectivity and people have done uh + + align:start position:0% +connectivity and people have done uh + + + align:start position:0% +connectivity and people have done uh +Neutron scattering to actually look at + + align:start position:0% +Neutron scattering to actually look at + + + align:start position:0% +Neutron scattering to actually look at +the Atomic + + align:start position:0% +the Atomic + + + align:start position:0% +the Atomic +displacement in this materials so you + + align:start position:0% +displacement in this materials so you + + + align:start position:0% +displacement in this materials so you +can see here this is a lum uh uh cobal + + align:start position:0% +can see here this is a lum uh uh cobal + + + align:start position:0% +can see here this is a lum uh uh cobal +anite right so uh here you have ion + + align:start position:0% +anite right so uh here you have ion + + + align:start position:0% +anite right so uh here you have ion +cobal that's their atomic display of it + + align:start position:0% +cobal that's their atomic display of it + + + align:start position:0% +cobal that's their atomic display of it +so inside is doing Browning motion and + + align:start position:0% +so inside is doing Browning motion and + + + align:start position:0% +so inside is doing Browning motion and +this measurement you can actually + + align:start position:0% +this measurement you can actually + + + align:start position:0% +this measurement you can actually +measure what's the amplitude this is + + align:start position:0% +measure what's the amplitude this is + + + align:start position:0% +measure what's the amplitude this is +Armstrong Square you here and what's the + + align:start position:0% +Armstrong Square you here and what's the + + + align:start position:0% +Armstrong Square you here and what's the +amplitude of the motion and the Lum they + + align:start position:0% +amplitude of the motion and the Lum they + + + align:start position:0% +amplitude of the motion and the Lum they +put into the cage there seems to be have + + align:start position:0% +put into the cage there seems to be have + + + align:start position:0% +put into the cage there seems to be have +a very large uh ude here you can see and + + align:start position:0% +a very large uh ude here you can see and + + + align:start position:0% +a very large uh ude here you can see and +the uh the theory is that this uh + + align:start position:0% +the uh the theory is that this uh + + + align:start position:0% +the uh the theory is that this uh +scatter the fors I think the again the + + align:start position:0% +scatter the fors I think the again the + + + align:start position:0% +scatter the fors I think the again the +theory is still evolving okay and the + + align:start position:0% +theory is still evolving okay and the + + + align:start position:0% +theory is still evolving okay and the +explanation people have came up with + + align:start position:0% +explanation people have came up with + + + align:start position:0% +explanation people have came up with +different explanations but you try to uh + + align:start position:0% +different explanations but you try to uh + + + align:start position:0% +different explanations but you try to uh +uh do the uh uh modeling experiment to + + align:start position:0% +uh do the uh uh modeling experiment to + + + align:start position:0% +uh do the uh uh modeling experiment to +really make this + + align:start position:0% +really make this + + + align:start position:0% +really make this +muchal uh here + + align:start position:0% +muchal uh here + + + align:start position:0% +muchal uh here +uh is the uh this is a I I think I + + align:start position:0% +uh is the uh this is a I I think I + + + align:start position:0% +uh is the uh this is a I I think I +forgot whether this is G type and N type + + align:start position:0% +forgot whether this is G type and N type + + + align:start position:0% +forgot whether this is G type and N type +and but I do want to tell you a + + align:start position:0% +and but I do want to tell you a + + + align:start position:0% +and but I do want to tell you a +story uh many uh years ago people + + align:start position:0% +story uh many uh years ago people + + + align:start position:0% +story uh many uh years ago people +reported P type uh scites cob timite + + align:start position:0% +reported P type uh scites cob timite + + + align:start position:0% +reported P type uh scites cob timite +have figure merital + + align:start position:0% +have figure merital + + + align:start position:0% +have figure merital +1.4 and now nobody can get + + align:start position:0% +1.4 and now nobody can get + + + align:start position:0% +1.4 and now nobody can get +1.4 everybody the best you can get is + + align:start position:0% +1.4 everybody the best you can get is + + + align:start position:0% +1.4 everybody the best you can get is +.95 and the reason this is bring up a + + align:start position:0% +.95 and the reason this is bring up a + + + align:start position:0% +.95 and the reason this is bring up a +very important Point Thal electrical + + align:start position:0% +very important Point Thal electrical + + + align:start position:0% +very important Point Thal electrical +research measuring this property is + + align:start position:0% +research measuring this property is + + + align:start position:0% +research measuring this property is +tricky okay and it has three property to + + align:start position:0% +tricky okay and it has three property to + + + align:start position:0% +tricky okay and it has three property to +measure electric conductivity thermal + + align:start position:0% +measure electric conductivity thermal + + + align:start position:0% +measure electric conductivity thermal +conductivity cack and even if you are + + align:start position:0% +conductivity cack and even if you are + + + align:start position:0% +conductivity cack and even if you are +very good each property you say okay I + + align:start position:0% +very good each property you say okay I + + + align:start position:0% +very good each property you say okay I +have about 5% uncertainty which I think + + align:start position:0% +have about 5% uncertainty which I think + + + align:start position:0% +have about 5% uncertainty which I think +is pretty good right + + align:start position:0% +is pretty good right + + + align:start position:0% +is pretty good right +and you go to calc our certainty range + + align:start position:0% +and you go to calc our certainty range + + + align:start position:0% +and you go to calc our certainty range +and that's about + + align:start position:0% +and that's about + + + align:start position:0% +and that's about +15% right and it turns out that many + + align:start position:0% +15% right and it turns out that many + + + align:start position:0% +15% right and it turns out that many +times your system can take the same + + align:start position:0% +times your system can take the same + + + align:start position:0% +times your system can take the same +sample so you do Cal conductivity take a + + align:start position:0% +sample so you do Cal conductivity take a + + + align:start position:0% +sample so you do Cal conductivity take a +sample you go to pick another sample for + + align:start position:0% +sample you go to pick another sample for + + + align:start position:0% +sample you go to pick another sample for +electric conductivity and uh you + + align:start position:0% +electric conductivity and uh you + + + align:start position:0% +electric conductivity and uh you +measure wrong + + align:start position:0% +measure wrong + + + align:start position:0% +measure wrong +things and sometimes if you look at bu + + align:start position:0% +things and sometimes if you look at bu + + + align:start position:0% +things and sometimes if you look at bu +uh Chate it's layer structure right the + + align:start position:0% +uh Chate it's layer structure right the + + + align:start position:0% +uh Chate it's layer structure right the +property is very + + align:start position:0% +property is very + + + align:start position:0% +property is very +isotropic this will be uh uh really + + align:start position:0% +isotropic this will be uh uh really + + + align:start position:0% +isotropic this will be uh uh really +dangerous you you measure even the same + + align:start position:0% +dangerous you you measure even the same + + + align:start position:0% +dangerous you you measure even the same +sample you you measure property C in One + + align:start position:0% +sample you you measure property C in One + + + align:start position:0% +sample you you measure property C in One +Direction measure Electric in other + + align:start position:0% +Direction measure Electric in other + + + align:start position:0% +Direction measure Electric in other +direction and you can just get a good ZT + + align:start position:0% +direction and you can just get a good ZT + + + align:start position:0% +direction and you can just get a good ZT +that's not true so this is a every time + + align:start position:0% +that's not true so this is a every time + + + align:start position:0% +that's not true so this is a every time +you going to mean it people will be + + align:start position:0% +you going to mean it people will be + + + align:start position:0% +you going to mean it people will be +debating and most of time people are + + align:start position:0% +debating and most of time people are + + + align:start position:0% +debating and most of time people are +skep of any + + align:start position:0% +skep of any + + + align:start position:0% +skep of any +report okay it's just difficult because + + align:start position:0% +report okay it's just difficult because + + + align:start position:0% +report okay it's just difficult because +measurement + + align:start position:0% + + + + align:start position:0% + +difficult okay now uh I turn to my cvor + + align:start position:0% +difficult okay now uh I turn to my cvor + + + align:start position:0% +difficult okay now uh I turn to my cvor +right n structure I said that they bulk + + align:start position:0% +right n structure I said that they bulk + + + align:start position:0% +right n structure I said that they bulk +material people look at different + + align:start position:0% +material people look at different + + + align:start position:0% +material people look at different +material different structures uh uh full + + align:start position:0% +material different structures uh uh full + + + align:start position:0% +material different structures uh uh full +rular those are all working on crystal + + align:start position:0% +rular those are all working on crystal + + + align:start position:0% +rular those are all working on crystal +line + + align:start position:0% +line + + + align:start position:0% +line +materials and there was say this another + + align:start position:0% +materials and there was say this another + + + align:start position:0% +materials and there was say this another +structur + + align:start position:0% +structur + + + align:start position:0% +structur +approach uh was really uh a m gr house + + align:start position:0% +approach uh was really uh a m gr house + + + align:start position:0% +approach uh was really uh a m gr house +in the E Department uh at the time and + + align:start position:0% +in the E Department uh at the time and + + + align:start position:0% +in the E Department uh at the time and +the story is this is a really a good + + align:start position:0% +the story is this is a really a good + + + align:start position:0% +the story is this is a really a good +story okay uh in around the 990 uh US + + align:start position:0% +story okay uh in around the 990 uh US + + + align:start position:0% +story okay uh in around the 990 uh US +Navy uh start to rethink thero electrics + + align:start position:0% +Navy uh start to rethink thero electrics + + + align:start position:0% +Navy uh start to rethink thero electrics +so they went ask around and they came to + + align:start position:0% +so they went ask around and they came to + + + align:start position:0% +so they went ask around and they came to +Millie whether she had any idea on ther + + align:start position:0% +Millie whether she had any idea on ther + + + align:start position:0% +Millie whether she had any idea on ther +elrics Millie didn't uh work on Elric + + align:start position:0% +elrics Millie didn't uh work on Elric + + + align:start position:0% +elrics Millie didn't uh work on Elric +before and uh but she s about it and + + align:start position:0% +before and uh but she s about it and + + + align:start position:0% +before and uh but she s about it and +there was a pH student walked into her + + align:start position:0% +there was a pH student walked into her + + + align:start position:0% +there was a pH student walked into her +office want to do was ask her whether + + align:start position:0% +office want to do was ask her whether + + + align:start position:0% +office want to do was ask her whether +she had a topic so she said oh why don't + + align:start position:0% +she had a topic so she said oh why don't + + + align:start position:0% +she had a topic so she said oh why don't +you look at the uh condom well whether + + align:start position:0% +you look at the uh condom well whether + + + align:start position:0% +you look at the uh condom well whether +you can give better uh super electric + + align:start position:0% +you can give better uh super electric + + + align:start position:0% +you can give better uh super electric +properties uh so the student looked and + + align:start position:0% +properties uh so the student looked and + + + align:start position:0% +properties uh so the student looked and +did it's really a homework problem I + + align:start position:0% +did it's really a homework problem I + + + align:start position:0% +did it's really a homework problem I +I'll show you later and but the + + align:start position:0% +I'll show you later and but the + + + align:start position:0% +I'll show you later and but the +calculation turns out to be really + + align:start position:0% +calculation turns out to be really + + + align:start position:0% +calculation turns out to be really +interesting and lot people start working + + align:start position:0% +interesting and lot people start working + + + align:start position:0% +interesting and lot people start working +on that so sometimes a simple idea + + align:start position:0% +on that so sometimes a simple idea + + + align:start position:0% +on that so sometimes a simple idea +really + + align:start position:0% +really + + + align:start position:0% +really +uh + + align:start position:0% +uh + + + align:start position:0% +uh +research and here uh I'm this is a slide + + align:start position:0% +research and here uh I'm this is a slide + + + align:start position:0% +research and here uh I'm this is a slide +that I triy to make and they seeing the + + align:start position:0% +that I triy to make and they seeing the + + + align:start position:0% +that I triy to make and they seeing the +potential of using n so uh you think + + align:start position:0% +potential of using n so uh you think + + + align:start position:0% +potential of using n so uh you think +about the electron and Fon electron is + + align:start position:0% +about the electron and Fon electron is + + + align:start position:0% +about the electron and Fon electron is +what carries heat around and of course + + align:start position:0% +what carries heat around and of course + + + align:start position:0% +what carries heat around and of course +they are Quant mechanic they all waves + + align:start position:0% +they are Quant mechanic they all waves + + + align:start position:0% +they are Quant mechanic they all waves +we we mentioned those W before but they + + align:start position:0% +we we mentioned those W before but they + + + align:start position:0% +we we mentioned those W before but they +have different wavelengths okay and in + + align:start position:0% +have different wavelengths okay and in + + + align:start position:0% +have different wavelengths okay and in +terms of it's a spread okay in real + + align:start position:0% +terms of it's a spread okay in real + + + align:start position:0% +terms of it's a spread okay in real +material it's all a spread and uh U we + + align:start position:0% +material it's all a spread and uh U we + + + align:start position:0% +material it's all a spread and uh U we +need to look into details but in general + + align:start position:0% +need to look into details but in general + + + align:start position:0% +need to look into details but in general +actually electron winess can be long + + align:start position:0% +actually electron winess can be long + + + align:start position:0% +actually electron winess can be long +average speaking then the fullon he + + align:start position:0% +average speaking then the fullon he + + + align:start position:0% +average speaking then the fullon he +carrying for ons and so uh so that's uh + + align:start position:0% +carrying for ons and so uh so that's uh + + + align:start position:0% +carrying for ons and so uh so that's uh +sort of order magnitud that I could I I + + align:start position:0% +sort of order magnitud that I could I I + + + align:start position:0% +sort of order magnitud that I could I I +often use but again each material is + + align:start position:0% +often use but again each material is + + + align:start position:0% +often use but again each material is +different temp is + + align:start position:0% +different temp is + + + align:start position:0% +different temp is +different and the other is me free + + align:start position:0% +different and the other is me free + + + align:start position:0% +different and the other is me free +pa okay that's the average distance + + align:start position:0% +pa okay that's the average distance + + + align:start position:0% +pa okay that's the average distance +electron fall on + + align:start position:0% +electron fall on + + + align:start position:0% +electron fall on +TRS so uh we you look at one possibility + + align:start position:0% +TRS so uh we you look at one possibility + + + align:start position:0% +TRS so uh we you look at one possibility +is really look at the wavelength + + align:start position:0% +is really look at the wavelength + + + align:start position:0% +is really look at the wavelength +difference and uh because the wavelength + + align:start position:0% +difference and uh because the wavelength + + + align:start position:0% +difference and uh because the wavelength +difference means uh intutive picture is + + align:start position:0% +difference means uh intutive picture is + + + align:start position:0% +difference means uh intutive picture is +that if you have a surface whether it's + + align:start position:0% +that if you have a surface whether it's + + + align:start position:0% +that if you have a surface whether it's +smooth or rough right really depends on + + align:start position:0% +smooth or rough right really depends on + + + align:start position:0% +smooth or rough right really depends on +the feature on the on the surface versus + + align:start position:0% +the feature on the on the surface versus + + + align:start position:0% +the feature on the on the surface versus +the feature of the wave wavess right if + + align:start position:0% +the feature of the wave wavess right if + + + align:start position:0% +the feature of the wave wavess right if +you have uh visible light coming towards + + align:start position:0% +you have uh visible light coming towards + + + align:start position:0% +you have uh visible light coming towards +a surface like this it look rough it's + + align:start position:0% +a surface like this it look rough it's + + + align:start position:0% +a surface like this it look rough it's +scatter light to all Direction but if + + align:start position:0% +scatter light to all Direction but if + + + align:start position:0% +scatter light to all Direction but if +you have really a microwave coming in + + align:start position:0% +you have really a microwave coming in + + + align:start position:0% +you have really a microwave coming in +very long wavelength this surface will + + align:start position:0% +very long wavelength this surface will + + + align:start position:0% +very long wavelength this surface will +be smooth much say uh we larger than the + + align:start position:0% +be smooth much say uh we larger than the + + + align:start position:0% +be smooth much say uh we larger than the +roughness + + align:start position:0% +roughness + + + align:start position:0% +roughness +fees uh so one of this idea was if you + + align:start position:0% +fees uh so one of this idea was if you + + + align:start position:0% +fees uh so one of this idea was if you +recall the thermal conductivity right + + align:start position:0% +recall the thermal conductivity right + + + align:start position:0% +recall the thermal conductivity right +the Curve at a very low temperature the + + align:start position:0% +the Curve at a very low temperature the + + + align:start position:0% +the Curve at a very low temperature the +Cal conductivity increase with the + + align:start position:0% +Cal conductivity increase with the + + + align:start position:0% +Cal conductivity increase with the +specific heat because the mean free pass + + align:start position:0% +specific heat because the mean free pass + + + align:start position:0% +specific heat because the mean free pass +equals sample size is limited by sample + + align:start position:0% +equals sample size is limited by sample + + + align:start position:0% +equals sample size is limited by sample +size so low temperature already have the + + align:start position:0% +size so low temperature already have the + + + align:start position:0% +size so low temperature already have the +size + + align:start position:0% +size + + + align:start position:0% +size +effect and if I make this structure very + + align:start position:0% +effect and if I make this structure very + + + align:start position:0% +effect and if I make this structure very +small that size effect can shift to high + + align:start position:0% +small that size effect can shift to high + + + align:start position:0% +small that size effect can shift to high +temperature as long as small enough so + + align:start position:0% +temperature as long as small enough so + + + align:start position:0% +temperature as long as small enough so +that the let's take a wire or + + align:start position:0% +that the let's take a wire or + + + align:start position:0% +that the let's take a wire or +fi if the diameter or thickness is + + align:start position:0% +fi if the diameter or thickness is + + + align:start position:0% +fi if the diameter or thickness is +comparable to MRE PA now the Fallon will + + align:start position:0% +comparable to MRE PA now the Fallon will + + + align:start position:0% +comparable to MRE PA now the Fallon will +no longer is a Fallon Fon pooll they are + + align:start position:0% +no longer is a Fallon Fon pooll they are + + + align:start position:0% +no longer is a Fallon Fon pooll they are +colled with + + align:start position:0% +colled with + + + align:start position:0% +colled with +surface right and uh another simple + + align:start position:0% +surface right and uh another simple + + + align:start position:0% +surface right and uh another simple +intuitive picture is okay what happens + + align:start position:0% +intuitive picture is okay what happens + + + align:start position:0% +intuitive picture is okay what happens +have the interface of to material right + + align:start position:0% +have the interface of to material right + + + align:start position:0% +have the interface of to material right +uh you have the L wave coming in and at + + align:start position:0% +uh you have the L wave coming in and at + + + align:start position:0% +uh you have the L wave coming in and at +the interface you hear Echo High well we + + align:start position:0% +the interface you hear Echo High well we + + + align:start position:0% +the interface you hear Echo High well we +he Echo for the visible R audible range + + align:start position:0% +he Echo for the visible R audible range + + + align:start position:0% +he Echo for the visible R audible range +but see in the heat caring is terz Right + + align:start position:0% +but see in the heat caring is terz Right + + + align:start position:0% +but see in the heat caring is terz Right +depends on so those are high frequency + + align:start position:0% +depends on so those are high frequency + + + align:start position:0% +depends on so those are high frequency +you still got the same phenomena happen + + align:start position:0% +you still got the same phenomena happen + + + align:start position:0% +you still got the same phenomena happen +and the echo means some he go don't go + + align:start position:0% +and the echo means some he go don't go + + + align:start position:0% +and the echo means some he go don't go +forward anymore so you have you could + + align:start position:0% +forward anymore so you have you could + + + align:start position:0% +forward anymore so you have you could +use those phenomena to drop the Thal + + align:start position:0% +use those phenomena to drop the Thal + + + align:start position:0% +use those phenomena to drop the Thal +connectivity and uh M idea uh at the + + align:start position:0% +connectivity and uh M idea uh at the + + + align:start position:0% +connectivity and uh M idea uh at the +time was squeeze + + align:start position:0% +time was squeeze + + + align:start position:0% +time was squeeze +electrons okay so Quantum effect which + + align:start position:0% +electrons okay so Quantum effect which + + + align:start position:0% +electrons okay so Quantum effect which +I'll talk more but + + align:start position:0% +I'll talk more but + + + align:start position:0% +I'll talk more but +now think about the the quantum effect + + align:start position:0% +now think about the the quantum effect + + + align:start position:0% +now think about the the quantum effect +electron is a b wave wave function is a + + align:start position:0% +electron is a b wave wave function is a + + + align:start position:0% +electron is a b wave wave function is a +function this the S + + align:start position:0% +function this the S + + + align:start position:0% +function this the S +orbital we function is a ball okay and + + align:start position:0% +orbital we function is a ball okay and + + + align:start position:0% +orbital we function is a ball okay and +uh let's see this is the size of the + + align:start position:0% +uh let's see this is the size of the + + + align:start position:0% +uh let's see this is the size of the +ball let's say + + align:start position:0% +ball let's say + + + align:start position:0% +ball let's say +100 right now you fit this this electron + + align:start position:0% +100 right now you fit this this electron + + + align:start position:0% +100 right now you fit this this electron +you make a film only 10 Armstrong or 50 + + align:start position:0% +you make a film only 10 Armstrong or 50 + + + align:start position:0% +you make a film only 10 Armstrong or 50 +Armstrong What Happens the the ball is + + align:start position:0% +Armstrong What Happens the the ball is + + + align:start position:0% +Armstrong What Happens the the ball is +long longer a b right I once when I was + + align:start position:0% +long longer a b right I once when I was + + + align:start position:0% +long longer a b right I once when I was +student visiting lbl there was + + align:start position:0% +student visiting lbl there was + + + align:start position:0% +student visiting lbl there was +interesting analogy made by professor + + align:start position:0% +interesting analogy made by professor + + + align:start position:0% +interesting analogy made by professor +said think this you put a box ball into + + align:start position:0% +said think this you put a box ball into + + + align:start position:0% +said think this you put a box ball into +a piz of + + align:start position:0% +a piz of + + + align:start position:0% +a piz of +box you squeeze that wall you have + + align:start position:0% +box you squeeze that wall you have + + + align:start position:0% +box you squeeze that wall you have +energy compensation so that's the so you + + align:start position:0% +energy compensation so that's the so you + + + align:start position:0% +energy compensation so that's the so you +have this wave and when you size is + + align:start position:0% +have this wave and when you size is + + + align:start position:0% +have this wave and when you size is +small you you you quti the wave and uh + + align:start position:0% +small you you you quti the wave and uh + + + align:start position:0% +small you you you quti the wave and uh +you ideally what you want is this way is + + align:start position:0% +you ideally what you want is this way is + + + align:start position:0% +you ideally what you want is this way is +a under ideal pation you want this + + align:start position:0% +a under ideal pation you want this + + + align:start position:0% +a under ideal pation you want this +smooth surface okay you don't want the + + align:start position:0% +smooth surface okay you don't want the + + + align:start position:0% +smooth surface okay you don't want the +interface scatter + + align:start position:0% +interface scatter + + + align:start position:0% +interface scatter +electrons and it's possible again you + + align:start position:0% +electrons and it's possible again you + + + align:start position:0% +electrons and it's possible again you +think about the wavelength range right + + align:start position:0% +think about the wavelength range right + + + align:start position:0% +think about the wavelength range right +because we surface smooth or a rough + + align:start position:0% +because we surface smooth or a rough + + + align:start position:0% +because we surface smooth or a rough +depends on wavess for the case of + + align:start position:0% +depends on wavess for the case of + + + align:start position:0% +depends on wavess for the case of +electron the scatter is electrical + + align:start position:0% +electron the scatter is electrical + + + align:start position:0% +electron the scatter is electrical +potential your potential whether is + + align:start position:0% +potential your potential whether is + + + align:start position:0% +potential your potential whether is +rough or not and for the case of full on + + align:start position:0% +rough or not and for the case of full on + + + align:start position:0% +rough or not and for the case of full on +that way fundament is all electrostatic + + align:start position:0% +that way fundament is all electrostatic + + + align:start position:0% +that way fundament is all electrostatic +but it's really the you can think of + + align:start position:0% +but it's really the you can think of + + + align:start position:0% +but it's really the you can think of +mass Sprint whether this uh the force is + + align:start position:0% +mass Sprint whether this uh the force is + + + align:start position:0% +mass Sprint whether this uh the force is +RO + + align:start position:0% +RO + + + align:start position:0% +RO +now okay and so you actually have the + + align:start position:0% +now okay and so you actually have the + + + align:start position:0% +now okay and so you actually have the +potential if you think about the Fon and + + align:start position:0% +potential if you think about the Fon and + + + align:start position:0% +potential if you think about the Fon and +electron your your electron if you quiz + + align:start position:0% +electron your your electron if you quiz + + + align:start position:0% +electron your your electron if you quiz +it is the + + align:start position:0% +it is the + + + align:start position:0% +it is the +smooth and because the wance difference + + align:start position:0% +smooth and because the wance difference + + + align:start position:0% +smooth and because the wance difference +you can potentially actually have the + + align:start position:0% +you can potentially actually have the + + + align:start position:0% +you can potentially actually have the +same surface be Rock right for full the + + align:start position:0% +same surface be Rock right for full the + + + align:start position:0% +same surface be Rock right for full the +acoustic W so this will be idea your + + align:start position:0% +acoustic W so this will be idea your + + + align:start position:0% +acoustic W so this will be idea your +dreft you you want to screw up the + + align:start position:0% +dreft you you want to screw up the + + + align:start position:0% +dreft you you want to screw up the +atomical vibration but electron can go + + align:start position:0% +atomical vibration but electron can go + + + align:start position:0% +atomical vibration but electron can go +as a wave guide that that would be one + + align:start position:0% +as a wave guide that that would be one + + + align:start position:0% +as a wave guide that that would be one +scenario and people started uh uh a lot + + align:start position:0% +scenario and people started uh uh a lot + + + align:start position:0% +scenario and people started uh uh a lot +uh since many and in fact I should say + + align:start position:0% +uh since many and in fact I should say + + + align:start position:0% +uh since many and in fact I should say +at the same time they go to other places + + align:start position:0% +at the same time they go to other places + + + align:start position:0% +at the same time they go to other places +and people have similar idea although M + + align:start position:0% +and people have similar idea although M + + + align:start position:0% +and people have similar idea although M +did the really a good calculation uh uh + + align:start position:0% +did the really a good calculation uh uh + + + align:start position:0% +did the really a good calculation uh uh +this uh uh superl idea was from Rama Ron + + align:start position:0% +this uh uh superl idea was from Rama Ron + + + align:start position:0% +this uh uh superl idea was from Rama Ron +and what he did is the perpendicular + + align:start position:0% +and what he did is the perpendicular + + + align:start position:0% +and what he did is the perpendicular +direction to + + align:start position:0% +direction to + + + align:start position:0% +direction to +superus and this is a you can say uh the + + align:start position:0% +superus and this is a you can say uh the + + + align:start position:0% +superus and this is a you can say uh the +experiment Cal + + align:start position:0% +experiment Cal + + + align:start position:0% +experiment Cal +connectivity had uh dropped right say uh + + align:start position:0% +connectivity had uh dropped right say uh + + + align:start position:0% +connectivity had uh dropped right say uh +say the uh dis cite B is about 1.2 and + + align:start position:0% +say the uh dis cite B is about 1.2 and + + + align:start position:0% +say the uh dis cite B is about 1.2 and +they Dro + + align:start position:0% +they Dro + + + align:start position:0% +they Dro +to5 very difficult measurement and this + + align:start position:0% +to5 very difficult measurement and this + + + align:start position:0% +to5 very difficult measurement and this +is where I start getting into ther + + align:start position:0% +is where I start getting into ther + + + align:start position:0% +is where I start getting into ther +electrics my my thesis my wife my PhD I + + align:start position:0% +electrics my my thesis my wife my PhD I + + + align:start position:0% +electrics my my thesis my wife my PhD I +was looking at the superus he conduction + + align:start position:0% +was looking at the superus he conduction + + + align:start position:0% +was looking at the superus he conduction +I was aware about lasers not therm Elric + + align:start position:0% +I was aware about lasers not therm Elric + + + align:start position:0% +I was aware about lasers not therm Elric +I didn't know anything + + align:start position:0% +I didn't know anything + + + align:start position:0% +I didn't know anything +thric and uh uh the but the electron + + align:start position:0% +thric and uh uh the but the electron + + + align:start position:0% +thric and uh uh the but the electron +here decrease a little bit this s Square + + align:start position:0% +here decrease a little bit this s Square + + + align:start position:0% +here decrease a little bit this s Square +Sigma the power Factor s sare Sigma + + align:start position:0% +Sigma the power Factor s sare Sigma + + + align:start position:0% +Sigma the power Factor s sare Sigma +decre a little bit and in the case of + + align:start position:0% +decre a little bit and in the case of + + + align:start position:0% +decre a little bit and in the case of +this is + + align:start position:0% +this is + + + align:start position:0% +this is +a he grew this Le + + align:start position:0% +a he grew this Le + + + align:start position:0% +a he grew this Le +torite on Le site on Le torite and + + align:start position:0% +torite on Le site on Le torite and + + + align:start position:0% +torite on Le site on Le torite and +because the lce constant is very + + align:start position:0% +because the lce constant is very + + + align:start position:0% +because the lce constant is very +different the string so you grw certain + + align:start position:0% +different the string so you grw certain + + + align:start position:0% +different the string so you grw certain +sickness the string will break up the + + align:start position:0% +sickness the string will break up the + + + align:start position:0% +sickness the string will break up the +film and form dots so he grew those + + align:start position:0% +film and form dots so he grew those + + + align:start position:0% +film and form dots so he grew those +multi-layer + + align:start position:0% +multi-layer + + + align:start position:0% +multi-layer +structures and uh uh this picture I + + align:start position:0% +structures and uh uh this picture I + + + align:start position:0% +structures and uh uh this picture I +don't think it from him I don't remember + + align:start position:0% +don't think it from him I don't remember + + + align:start position:0% +don't think it from him I don't remember +but uh uh what he show was again no + + align:start position:0% +but uh uh what he show was again no + + + align:start position:0% +but uh uh what he show was again no +contivity and the par Factor so at the + + align:start position:0% +contivity and the par Factor so at the + + + align:start position:0% +contivity and the par Factor so at the +end it turns out + + align:start position:0% +end it turns out + + + align:start position:0% +end it turns out +that uh historically the connectivity + + align:start position:0% +that uh historically the connectivity + + + align:start position:0% +that uh historically the connectivity +alloy institutional right and now with + + align:start position:0% +alloy institutional right and now with + + + align:start position:0% +alloy institutional right and now with +the uh this Nan structure in terms of + + align:start position:0% +the uh this Nan structure in terms of + + + align:start position:0% +the uh this Nan structure in terms of +the really Thal contivity seems to be a + + align:start position:0% +the really Thal contivity seems to be a + + + align:start position:0% +the really Thal contivity seems to be a +very effective + + align:start position:0% +very effective + + + align:start position:0% +very effective +strategy but let me again + + align:start position:0% +strategy but let me again + + + align:start position:0% +strategy but let me again +o almost now see everybody question + + align:start position:0% +o almost now see everybody question + + + align:start position:0% +o almost now see everybody question +those + + align:start position:0% +those + + + align:start position:0% +those +results it's a a very interesting + + align:start position:0% +results it's a a very interesting + + + align:start position:0% +results it's a a very interesting +results very intriguant but it's a very + + align:start position:0% +results very intriguant but it's a very + + + align:start position:0% +results very intriguant but it's a very +hard + + align:start position:0% +hard + + + align:start position:0% +hard +measurement and uh uh uh retire is I + + align:start position:0% +measurement and uh uh uh retire is I + + + align:start position:0% +measurement and uh uh uh retire is I +very respected and I I talk to him a + + align:start position:0% +very respected and I I talk to him a + + + align:start position:0% +very respected and I I talk to him a +lot he has a book if you want to + + align:start position:0% +lot he has a book if you want to + + + align:start position:0% +lot he has a book if you want to +understand Thermo Elric he has a very + + align:start position:0% +understand Thermo Elric he has a very + + + align:start position:0% +understand Thermo Elric he has a very +good book not many people read because + + align:start position:0% +good book not many people read because + + + align:start position:0% +good book not many people read because +it's too + + align:start position:0% +it's too + + + align:start position:0% +it's too +difficult but very good if you if you + + align:start position:0% +difficult but very good if you if you + + + align:start position:0% +difficult but very good if you if you +read and the first picture I remember + + align:start position:0% +read and the first picture I remember + + + align:start position:0% +read and the first picture I remember +first two pages was talking about + + align:start position:0% +first two pages was talking about + + + align:start position:0% +first two pages was talking about +electrostatic potential as a mechanical + + align:start position:0% +electrostatic potential as a mechanical + + + align:start position:0% +electrostatic potential as a mechanical +engineer that always being har um + + align:start position:0% +engineer that always being har um + + + align:start position:0% +engineer that always being har um +understand what's the electrical + + align:start position:0% +understand what's the electrical + + + align:start position:0% +understand what's the electrical +potential what's the C + + align:start position:0% +potential what's the C + + + align:start position:0% +potential what's the C +po okay and uh uh Rama wonan this from + + align:start position:0% +po okay and uh uh Rama wonan this from + + + align:start position:0% +po okay and uh uh Rama wonan this from +RTI they have a uh spin up company + + align:start position:0% +RTI they have a uh spin up company + + + align:start position:0% +RTI they have a uh spin up company +trying to do the super lysis for micro + + align:start position:0% +trying to do the super lysis for micro + + + align:start position:0% +trying to do the super lysis for micro +electronics coing and if you're + + align:start position:0% +electronics coing and if you're + + + align:start position:0% +electronics coing and if you're +interested you can check Le they have + + align:start position:0% +interested you can check Le they have + + + align:start position:0% +interested you can check Le they have +that's the + + align:start position:0% +that's the + + + align:start position:0% +that's the +startups and uh uh uh the the uh the + + align:start position:0% +startups and uh uh uh the the uh the + + + align:start position:0% +startups and uh uh uh the the uh the +super L is uh I guess say the the + + align:start position:0% +super L is uh I guess say the the + + + align:start position:0% +super L is uh I guess say the the +challenge is grew very thck and also + + align:start position:0% +challenge is grew very thck and also + + + align:start position:0% +challenge is grew very thck and also +reduce the + + align:start position:0% +reduce the + + + align:start position:0% +reduce the +cost so this is where my story is I I + + align:start position:0% +cost so this is where my story is I I + + + align:start position:0% +cost so this is where my story is I I +said I have been working on this for a + + align:start position:0% +said I have been working on this for a + + + align:start position:0% +said I have been working on this for a +long time uh since my uh + + align:start position:0% +long time uh since my uh + + + align:start position:0% +long time uh since my uh +was really use for + + align:start position:0% +was really use for + + + align:start position:0% +was really use for +leers and uh uh uh so those are + + align:start position:0% +leers and uh uh uh so those are + + + align:start position:0% +leers and uh uh uh so those are +experiments uh in the along the film + + align:start position:0% +experiments uh in the along the film + + + align:start position:0% +experiments uh in the along the film +Direction you can see isotopic this + + align:start position:0% +Direction you can see isotopic this + + + align:start position:0% +Direction you can see isotopic this +is but's see uh the super structure + + align:start position:0% +is but's see uh the super structure + + + align:start position:0% +is but's see uh the super structure +right so this is a perpendicular to the + + align:start position:0% +right so this is a perpendicular to the + + + align:start position:0% +right so this is a perpendicular to the +fil plan Direction parallel to film plan + + align:start position:0% +fil plan Direction parallel to film plan + + + align:start position:0% +fil plan Direction parallel to film plan +Direction and the problem is if you + + align:start position:0% +Direction and the problem is if you + + + align:start position:0% +Direction and the problem is if you +think about this super l space l this + + align:start position:0% +think about this super l space l this + + + align:start position:0% +think about this super l space l this +were super ltis was + + align:start position:0% +were super ltis was + + + align:start position:0% +were super ltis was +invented by uh R2 and isak isaki got the + + align:start position:0% +invented by uh R2 and isak isaki got the + + + align:start position:0% +invented by uh R2 and isak isaki got the +low price uh for his work in resent dial + + align:start position:0% +low price uh for his work in resent dial + + + align:start position:0% +low price uh for his work in resent dial +okay that's before he even super + + align:start position:0% +okay that's before he even super + + + align:start position:0% +okay that's before he even super +this and the L of super litis means you + + align:start position:0% +this and the L of super litis means you + + + align:start position:0% +this and the L of super litis means you +have a super + + align:start position:0% +have a super + + + align:start position:0% +have a super +freal and so you see say this is one + + align:start position:0% +freal and so you see say this is one + + + align:start position:0% +freal and so you see say this is one +layer this another layer now you look at + + align:start position:0% +layer this another layer now you look at + + + align:start position:0% +layer this another layer now you look at +a Unis is no longer CU but the uh + + align:start position:0% +a Unis is no longer CU but the uh + + + align:start position:0% +a Unis is no longer CU but the uh +cedra that cover from here to here one + + align:start position:0% +cedra that cover from here to here one + + + align:start position:0% +cedra that cover from here to here one +period of a crystal right so that's what + + align:start position:0% +period of a crystal right so that's what + + + align:start position:0% +period of a crystal right so that's what +the Lan implies if you have this + + align:start position:0% +the Lan implies if you have this + + + align:start position:0% +the Lan implies if you have this +according to the Lan this is new Crystal + + align:start position:0% +according to the Lan this is new Crystal + + + align:start position:0% +according to the Lan this is new Crystal +you can calculate the new energy for on + + align:start position:0% +you can calculate the new energy for on + + + align:start position:0% +you can calculate the new energy for on +Spectrum you calc grou velocity you C + + align:start position:0% +Spectrum you calc grou velocity you C + + + align:start position:0% +Spectrum you calc grou velocity you C +sub states do all this calculation and + + align:start position:0% +sub states do all this calculation and + + + align:start position:0% +sub states do all this calculation and +then you do one c v gamma I don't know + + align:start position:0% +then you do one c v gamma I don't know + + + align:start position:0% +then you do one c v gamma I don't know +gamma so but I know I can from that + + align:start position:0% +gamma so but I know I can from that + + + align:start position:0% +gamma so but I know I can from that +calculation I know see and not weak from + + align:start position:0% +calculation I know see and not weak from + + + align:start position:0% +calculation I know see and not weak from +density of St and dis and that's the + + align:start position:0% +density of St and dis and that's the + + + align:start position:0% +density of St and dis and that's the +curve you get as a function of thickness + + align:start position:0% +curve you get as a function of thickness + + + align:start position:0% +curve you get as a function of thickness +just it's not correct okay so basically + + align:start position:0% +just it's not correct okay so basically + + + align:start position:0% +just it's not correct okay so basically +the picture is not + + align:start position:0% +the picture is not + + + align:start position:0% +the picture is not +about forming a coherent structure + + align:start position:0% +about forming a coherent structure + + + align:start position:0% +about forming a coherent structure +people are still debating so I don't + + align:start position:0% +people are still debating so I don't + + + align:start position:0% +people are still debating so I don't +want to prejuce you you should read + + align:start position:0% +want to prejuce you you should read + + + align:start position:0% +want to prejuce you you should read +literature and that's my own Prejudice + + align:start position:0% +literature and that's my own Prejudice + + + align:start position:0% +literature and that's my own Prejudice +because I been doing research in that + + align:start position:0% +because I been doing research in that + + + align:start position:0% +because I been doing research in that +but when you get into it say oh I don't + + align:start position:0% +but when you get into it say oh I don't + + + align:start position:0% +but when you get into it say oh I don't +believe that look into literature look + + align:start position:0% +believe that look into literature look + + + align:start position:0% +believe that look into literature look +at the different sides of the + + align:start position:0% +at the different sides of the + + + align:start position:0% +at the different sides of the +argument + + align:start position:0% +argument + + + align:start position:0% +argument +okay and uh so when I go to look into + + align:start position:0% +okay and uh so when I go to look into + + + align:start position:0% +okay and uh so when I go to look into +the other picture just say okay now I + + align:start position:0% +the other picture just say okay now I + + + align:start position:0% +the other picture just say okay now I +got a + + align:start position:0% +got a + + + align:start position:0% +got a +surface I I only just consider not this + + align:start position:0% +surface I I only just consider not this + + + align:start position:0% +surface I I only just consider not this +super cell just two layers and of course + + align:start position:0% +super cell just two layers and of course + + + align:start position:0% +super cell just two layers and of course +periodic structure we consider all that + + align:start position:0% +periodic structure we consider all that + + + align:start position:0% +periodic structure we consider all that +and then we got the interface + + align:start position:0% +and then we got the interface + + + align:start position:0% +and then we got the interface +roughness and that roughness scatter + + align:start position:0% +roughness and that roughness scatter + + + align:start position:0% +roughness and that roughness scatter +foron diffuse the and that can cause the + + align:start position:0% +foron diffuse the and that can cause the + + + align:start position:0% +foron diffuse the and that can cause the +reduction and here I got a fuding + + align:start position:0% +reduction and here I got a fuding + + + align:start position:0% +reduction and here I got a fuding +parameter yes when you say roughness are + + align:start position:0% +parameter yes when you say roughness are + + + align:start position:0% +parameter yes when you say roughness are +you talking about just like obstacle + + align:start position:0% +you talking about just like obstacle + + + align:start position:0% +you talking about just like obstacle +spacing like an electron defraction or + + align:start position:0% +spacing like an electron defraction or + + + align:start position:0% +spacing like an electron defraction or +any other defraction experiment that + + align:start position:0% +any other defraction experiment that + + + align:start position:0% +any other defraction experiment that +like you expect something to be + + align:start position:0% +like you expect something to be + + + align:start position:0% +like you expect something to be +scattered by something with spacing your + + align:start position:0% +scattered by something with spacing your + + + align:start position:0% +scattered by something with spacing your +right right so so that's a very good + + align:start position:0% +right right so so that's a very good + + + align:start position:0% +right right so so that's a very good +question and what's the mechanism of + + align:start position:0% +question and what's the mechanism of + + + align:start position:0% +question and what's the mechanism of +that + + align:start position:0% +that + + + align:start position:0% +that +roughness and it turns + + align:start position:0% +roughness and it turns + + + align:start position:0% +roughness and it turns +out that say when you grw super L + + align:start position:0% +out that say when you grw super L + + + align:start position:0% +out that say when you grw super L +molecular + + align:start position:0% +molecular + + + align:start position:0% +molecular +and you find out there in the 80s there + + align:start position:0% +and you find out there in the 80s there + + + align:start position:0% +and you find out there in the 80s there +a lot of study gas is best study system + + align:start position:0% +a lot of study gas is best study system + + + align:start position:0% +a lot of study gas is best study system +and there are diffusion of atoms between + + align:start position:0% +and there are diffusion of atoms between + + + align:start position:0% +and there are diffusion of atoms between +the layers about one two three mon + + align:start position:0% +the layers about one two three mon + + + align:start position:0% +the layers about one two three mon +Atomic + + align:start position:0% +Atomic + + + align:start position:0% +Atomic +layer and I said the full weakness is + + align:start position:0% +layer and I said the full weakness is + + + align:start position:0% +layer and I said the full weakness is +very short right so my picture is really + + align:start position:0% +very short right so my picture is really + + + align:start position:0% +very short right so my picture is really +the atom if it's a perfect periodic you + + align:start position:0% +the atom if it's a perfect periodic you + + + align:start position:0% +the atom if it's a perfect periodic you +see the atomic space is all PR the same + + align:start position:0% +see the atomic space is all PR the same + + + align:start position:0% +see the atomic space is all PR the same +atom then you should not have that but + + align:start position:0% +atom then you should not have that but + + + align:start position:0% +atom then you should not have that but +now if you just have one atom per two + + align:start position:0% +now if you just have one atom per two + + + align:start position:0% +now if you just have one atom per two +and then random distance later another + + align:start position:0% +and then random distance later another + + + align:start position:0% +and then random distance later another +atom protr and that's say a surface + + align:start position:0% +atom protr and that's say a surface + + + align:start position:0% +atom protr and that's say a surface +whether is rough or or smooth is about + + align:start position:0% +whether is rough or or smooth is about + + + align:start position:0% +whether is rough or or smooth is about +one1 of the wavelength so if you go the + + align:start position:0% +one1 of the wavelength so if you go the + + + align:start position:0% +one1 of the wavelength so if you go the +Optics so here again we do know exactly + + align:start position:0% +Optics so here again we do know exactly + + + align:start position:0% +Optics so here again we do know exactly +so good Optics when people say whether + + align:start position:0% +so good Optics when people say whether + + + align:start position:0% +so good Optics when people say whether +surface is smooth or not is about one1 + + align:start position:0% +surface is smooth or not is about one1 + + + align:start position:0% +surface is smooth or not is about one1 +Wess right one you look at the uh the + + align:start position:0% +Wess right one you look at the uh the + + + align:start position:0% +Wess right one you look at the uh the +face of the wave so uh here because the + + align:start position:0% +face of the wave so uh here because the + + + align:start position:0% +face of the wave so uh here because the +weakness of foron is about 1 n to 10 NM + + align:start position:0% +weakness of foron is about 1 n to 10 NM + + + align:start position:0% +weakness of foron is about 1 n to 10 NM +R so a little bit atom diffusion can PA + + align:start position:0% +R so a little bit atom diffusion can PA + + + align:start position:0% +R so a little bit atom diffusion can PA +that but there are a lot of puzzles at + + align:start position:0% +that but there are a lot of puzzles at + + + align:start position:0% +that but there are a lot of puzzles at +this stage okay you should read uh D + + align:start position:0% +this stage okay you should read uh D + + + align:start position:0% +this stage okay you should read uh D +paper from U and they have done constant + + align:start position:0% +paper from U and they have done constant + + + align:start position:0% +paper from U and they have done constant +dite and some newer material system and + + align:start position:0% +dite and some newer material system and + + + align:start position:0% +dite and some newer material system and +they found that they can have S + + align:start position:0% +they found that they can have S + + + align:start position:0% +they found that they can have S +connectivity really really the noise + + align:start position:0% +connectivity really really the noise + + + align:start position:0% +connectivity really really the noise +they have is twice air solid fully uh + + align:start position:0% +they have is twice air solid fully uh + + + align:start position:0% +they have is twice air solid fully uh +solid anyway so I I say uh uh this is a + + align:start position:0% +solid anyway so I I say uh uh this is a + + + align:start position:0% +solid anyway so I I say uh uh this is a +uh the picture I have but I think there + + align:start position:0% +uh the picture I have but I think there + + + align:start position:0% +uh the picture I have but I think there +are probably more things uh that that we + + align:start position:0% +are probably more things uh that that we + + + align:start position:0% +are probably more things uh that that we +need to + + align:start position:0% +need to + + + align:start position:0% +need to +develop okay so but see from this + + align:start position:0% +develop okay so but see from this + + + align:start position:0% +develop okay so but see from this +picture what I conclude is okay we don't + + align:start position:0% +picture what I conclude is okay we don't + + + align:start position:0% +picture what I conclude is okay we don't +need the P structure because if it's not + + align:start position:0% +need the P structure because if it's not + + + align:start position:0% +need the P structure because if it's not +unic cell type of picture then I don't + + align:start position:0% +unic cell type of picture then I don't + + + align:start position:0% +unic cell type of picture then I don't +need a pure disy so that's what need us + + align:start position:0% +need a pure disy so that's what need us + + + align:start position:0% +need a pure disy so that's what need us +to to do this random composite + + align:start position:0% +to to do this random composite + + + align:start position:0% +to to do this random composite +structures because that way I can do Cod + + align:start position:0% +structures because that way I can do Cod + + + align:start position:0% +structures because that way I can do Cod +lower cost and + + align:start position:0% +lower cost and + + + align:start position:0% +lower cost and +uh uh so we we try this and it works in + + align:start position:0% +uh uh so we we try this and it works in + + + align:start position:0% +uh uh so we we try this and it works in +some materials right this is a + + align:start position:0% +some materials right this is a + + + align:start position:0% +some materials right this is a +uh lat right uh this is the this is a b + + align:start position:0% +uh lat right uh this is the this is a b + + + align:start position:0% +uh lat right uh this is the this is a b +that right and this is n no dis right + + align:start position:0% +that right and this is n no dis right + + + align:start position:0% +that right and this is n no dis right +dis right B and N and uh uh it turn what + + align:start position:0% +dis right B and N and uh uh it turn what + + + align:start position:0% +dis right B and N and uh uh it turn what +we do is just B material and we compact + + align:start position:0% +we do is just B material and we compact + + + align:start position:0% +we do is just B material and we compact +them into n form in work in dis ter + + align:start position:0% +them into n form in work in dis ter + + + align:start position:0% +them into n form in work in dis ter +works on SEC gtic also didn't quite work + + align:start position:0% +works on SEC gtic also didn't quite work + + + align:start position:0% +works on SEC gtic also didn't quite work +in that that the green + + align:start position:0% +in that that the green + + + align:start position:0% +in that that the green +gr and uh SC that didn't work out either + + align:start position:0% +gr and uh SC that didn't work out either + + + align:start position:0% +gr and uh SC that didn't work out either +and because GRE so we're still trying to + + align:start position:0% +and because GRE so we're still trying to + + + align:start position:0% +and because GRE so we're still trying to +figure out how we can prevent stop that + + align:start position:0% +figure out how we can prevent stop that + + + align:start position:0% +figure out how we can prevent stop that +grth of the GD and we drop the ther + + align:start position:0% +grth of the GD and we drop the ther + + + align:start position:0% +grth of the GD and we drop the ther +activity yes + + align:start position:0% + + + + align:start position:0% + +yeah that's that's a very good uh uh uh + + align:start position:0% +yeah that's that's a very good uh uh uh + + + align:start position:0% +yeah that's that's a very good uh uh uh +suggestion and I didn't look in C + + align:start position:0% +suggestion and I didn't look in C + + + align:start position:0% +suggestion and I didn't look in C +Crystal but but there are people looking + + align:start position:0% +Crystal but but there are people looking + + + align:start position:0% +Crystal but but there are people looking +to + + align:start position:0% +to + + + align:start position:0% +to +CL classro is a very complicated like uh + + align:start position:0% +CL classro is a very complicated like uh + + + align:start position:0% +CL classro is a very complicated like uh +you can have cicon in the crossroad + + align:start position:0% +you can have cicon in the crossroad + + + align:start position:0% +you can have cicon in the crossroad +geranium in Closs it's + + align:start position:0% +geranium in Closs it's + + + align:start position:0% +geranium in Closs it's +a it has a say has holes + + align:start position:0% +a it has a say has holes + + + align:start position:0% +a it has a say has holes +and uh they have + + align:start position:0% +and uh they have + + + align:start position:0% +and uh they have +little uh but for that c the + + align:start position:0% +little uh but for that c the + + + align:start position:0% +little uh but for that c the +CATE the case whether you can make the + + align:start position:0% +CATE the case whether you can make the + + + align:start position:0% +CATE the case whether you can make the +electron to move remember you can kill + + align:start position:0% +electron to move remember you can kill + + + align:start position:0% +electron to move remember you can kill +fullon if you just want to kill Fon + + align:start position:0% +fullon if you just want to kill Fon + + + align:start position:0% +fullon if you just want to kill Fon +that's easy but you also want to keep + + align:start position:0% +that's easy but you also want to keep + + + align:start position:0% +that's easy but you also want to keep +the electron moving so the idea the good + + align:start position:0% +the electron moving so the idea the good + + + align:start position:0% +the electron moving so the idea the good +a very good terminology came from glance + + align:start position:0% +a very good terminology came from glance + + + align:start position:0% +a very good terminology came from glance +SL and he said what do you want is + + align:start position:0% +SL and he said what do you want is + + + align:start position:0% +SL and he said what do you want is +electron Crystal for Fon glass in one + + align:start position:0% +electron Crystal for Fon glass in one + + + align:start position:0% +electron Crystal for Fon glass in one +material because Fon in glass this glass + + align:start position:0% +material because Fon in glass this glass + + + align:start position:0% +material because Fon in glass this glass +here am off us random Atomic Arrangement + + align:start position:0% +here am off us random Atomic Arrangement + + + align:start position:0% +here am off us random Atomic Arrangement +so the full onity is very cool but this + + align:start position:0% +so the full onity is very cool but this + + + align:start position:0% +so the full onity is very cool but this +super L is is + + align:start position:0% +super L is is + + + align:start position:0% +super L is is +different right it's still + + align:start position:0% +different right it's still + + + align:start position:0% +different right it's still +Crystal so you are uh whether we can for + + align:start position:0% +Crystal so you are uh whether we can for + + + align:start position:0% +Crystal so you are uh whether we can for +example we're looking randomized wave + + align:start position:0% +example we're looking randomized wave + + + align:start position:0% +example we're looking randomized wave +localize you you localize + + align:start position:0% +localize you you localize + + + align:start position:0% +localize you you localize +way very difficult I think but it's + + align:start position:0% +way very difficult I think but it's + + + align:start position:0% +way very difficult I think but it's +worth trying right and uh because say + + align:start position:0% +worth trying right and uh because say + + + align:start position:0% +worth trying right and uh because say +you need a crystal structure to get + + align:start position:0% +you need a crystal structure to get + + + align:start position:0% +you need a crystal structure to get +electron + + align:start position:0% +electron + + + align:start position:0% +electron +propagated very difficult because the + + align:start position:0% +propagated very difficult because the + + + align:start position:0% +propagated very difficult because the +sure wance you can do photonic Crystal + + align:start position:0% +sure wance you can do photonic Crystal + + + align:start position:0% +sure wance you can do photonic Crystal +or that for electromagnetic wave because + + align:start position:0% +or that for electromagnetic wave because + + + align:start position:0% +or that for electromagnetic wave because +the wav is pretty long but it's very + + align:start position:0% +the wav is pretty long but it's very + + + align:start position:0% +the wav is pretty long but it's very +hard to do this for fullon because wance + + align:start position:0% +hard to do this for fullon because wance + + + align:start position:0% +hard to do this for fullon because wance +is short and they don't propagate very + + align:start position:0% +is short and they don't propagate very + + + align:start position:0% +is short and they don't propagate very +long you need a long cerence to have the + + align:start position:0% +long you need a long cerence to have the + + + align:start position:0% +long you need a long cerence to have the +waves distract each other so those are + + align:start position:0% +waves distract each other so those are + + + align:start position:0% +waves distract each other so those are +the + + align:start position:0% + + + + align:start position:0% + +difficulties okay so here more detailed + + align:start position:0% +difficulties okay so here more detailed + + + align:start position:0% +difficulties okay so here more detailed +example this you can say the theral is + + align:start position:0% +example this you can say the theral is + + + align:start position:0% +example this you can say the theral is +Dro so when I started + + align:start position:0% +Dro so when I started + + + align:start position:0% +Dro so when I started +this everybody was saying electron what + + align:start position:0% +this everybody was saying electron what + + + align:start position:0% +this everybody was saying electron what +you to do with electron and said I don't + + align:start position:0% +you to do with electron and said I don't + + + align:start position:0% +you to do with electron and said I don't +know I wish it work out uh but when I + + align:start position:0% +know I wish it work out uh but when I + + + align:start position:0% +know I wish it work out uh but when I +think back you actually have good reason + + align:start position:0% +think back you actually have good reason + + + align:start position:0% +think back you actually have good reason +the general idea is okay let's don't get + + align:start position:0% +the general idea is okay let's don't get + + + align:start position:0% +the general idea is okay let's don't get +a too much electrical potential offset + + align:start position:0% +a too much electrical potential offset + + + align:start position:0% +a too much electrical potential offset +at the + + align:start position:0% +at the + + + align:start position:0% +at the +interface right that's what the scatter + + align:start position:0% +interface right that's what the scatter + + + align:start position:0% +interface right that's what the scatter +electron and uh but say it turns out uh + + align:start position:0% +electron and uh but say it turns out uh + + + align:start position:0% +electron and uh but say it turns out uh +in bu right you can see the electron is + + align:start position:0% +in bu right you can see the electron is + + + align:start position:0% +in bu right you can see the electron is +is better when I first look at this I + + align:start position:0% +is better when I first look at this I + + + align:start position:0% +is better when I first look at this I +couldn't believe right and the reason is + + align:start position:0% +couldn't believe right and the reason is + + + align:start position:0% +couldn't believe right and the reason is +of course it's semiconductor the + + align:start position:0% +of course it's semiconductor the + + + align:start position:0% +of course it's semiconductor the +electric conductivity depends on the + + align:start position:0% +electric conductivity depends on the + + + align:start position:0% +electric conductivity depends on the +carer concentration right it's a + + align:start position:0% +carer concentration right it's a + + + align:start position:0% +carer concentration right it's a +Mobility times n the car concentration + + align:start position:0% +Mobility times n the car concentration + + + align:start position:0% +Mobility times n the car concentration +times charge so turn out the dis ter + + align:start position:0% +times charge so turn out the dis ter + + + align:start position:0% +times charge so turn out the dis ter +when you it you generate defect that + + align:start position:0% +when you it you generate defect that + + + align:start position:0% +when you it you generate defect that +generate more electron or in this case + + align:start position:0% +generate more electron or in this case + + + align:start position:0% +generate more electron or in this case +more P because it's a positive you C is + + align:start position:0% +more P because it's a positive you C is + + + align:start position:0% +more P because it's a positive you C is +positive that's P again you can say + + align:start position:0% +positive that's P again you can say + + + align:start position:0% +positive that's P again you can say +that's the typical Behavior so at the + + align:start position:0% +that's the typical Behavior so at the + + + align:start position:0% +that's the typical Behavior so at the +end if I PL the s s here so higher + + align:start position:0% +end if I PL the s s here so higher + + + align:start position:0% +end if I PL the s s here so higher +electron density lower catback + + align:start position:0% +electron density lower catback + + + align:start position:0% +electron density lower catback +right higher electron density fir level + + align:start position:0% +right higher electron density fir level + + + align:start position:0% +right higher electron density fir level +is closer to the B Edge or even get into + + align:start position:0% +is closer to the B Edge or even get into + + + align:start position:0% +is closer to the B Edge or even get into +the B the C is the average distance + + align:start position:0% +the B the C is the average distance + + + align:start position:0% +the B the C is the average distance +thermal energy of electron Rel to C + + align:start position:0% +thermal energy of electron Rel to C + + + align:start position:0% +thermal energy of electron Rel to C +Potential from so higher electric + + align:start position:0% +Potential from so higher electric + + + align:start position:0% +Potential from so higher electric +connectivity lower C that's all but + + align:start position:0% +connectivity lower C that's all but + + + align:start position:0% +connectivity lower C that's all but +because it have higher car + + align:start position:0% +because it have higher car + + + align:start position:0% +because it have higher car +concentration the bipolar decrease start + + align:start position:0% +concentration the bipolar decrease start + + + align:start position:0% +concentration the bipolar decrease start +later you can see here right go to + + align:start position:0% +later you can see here right go to + + + align:start position:0% +later you can see here right go to +higher temperature + + align:start position:0% +higher temperature + + + align:start position:0% +higher temperature +and then uh so if you PL s sare Sigma + + align:start position:0% +and then uh so if you PL s sare Sigma + + + align:start position:0% +and then uh so if you PL s sare Sigma +this is actually better than + + align:start position:0% +this is actually better than + + + align:start position:0% +this is actually better than +this we try that very hard in superla we + + align:start position:0% +this we try that very hard in superla we + + + align:start position:0% +this we try that very hard in superla we +didn't get S squ Sigma both decreased + + align:start position:0% +didn't get S squ Sigma both decreased + + + align:start position:0% +didn't get S squ Sigma both decreased +Thal connectivity incre power factor and + + align:start position:0% +Thal connectivity incre power factor and + + + align:start position:0% +Thal connectivity incre power factor and +this actually work so um but we still + + align:start position:0% +this actually work so um but we still + + + align:start position:0% +this actually work so um but we still +don't know how exactly to model it very + + align:start position:0% +don't know how exactly to model it very + + + align:start position:0% +don't know how exactly to model it very +difficult to model in + + align:start position:0% + + + + align:start position:0% + +romu we do not and we another only one + + align:start position:0% +romu we do not and we another only one + + + align:start position:0% +romu we do not and we another only one +let me see uh in fact uh Mercury + + align:start position:0% +let me see uh in fact uh Mercury + + + align:start position:0% +let me see uh in fact uh Mercury +KES uh has been working this material + + align:start position:0% +KES uh has been working this material + + + align:start position:0% +KES uh has been working this material +system which play + + align:start position:0% +system which play + + + align:start position:0% +system which play +for last and so that + + align:start position:0% +for last and so that + + + align:start position:0% +for last and so that +turn and the single free store he grew + + align:start position:0% +turn and the single free store he grew + + + align:start position:0% +turn and the single free store he grew +single free spent several days to GRE + + align:start position:0% +single free spent several days to GRE + + + align:start position:0% +single free spent several days to GRE +single fre stores coing feeding and got + + align:start position:0% +single fre stores coing feeding and got + + + align:start position:0% +single fre stores coing feeding and got +a very good + + align:start position:0% +a very good + + + align:start position:0% +a very good +properties and again let me question you + + align:start position:0% +properties and again let me question you + + + align:start position:0% +properties and again let me question you +I can't believe this for point this he + + align:start position:0% +I can't believe this for point this he + + + align:start position:0% +I can't believe this for point this he +extrapolated no he doesn't show this + + align:start position:0% +extrapolated no he doesn't show this + + + align:start position:0% +extrapolated no he doesn't show this +anymore and measurement is always a hard + + align:start position:0% +anymore and measurement is always a hard + + + align:start position:0% +anymore and measurement is always a hard +problem this is a one has to realize + + align:start position:0% +problem this is a one has to realize + + + align:start position:0% +problem this is a one has to realize +sometimes I steare people away by saying + + align:start position:0% +sometimes I steare people away by saying + + + align:start position:0% +sometimes I steare people away by saying +that but that's reality have Cas and + + align:start position:0% +that but that's reality have Cas and + + + align:start position:0% +that but that's reality have Cas and +what they found later on is that in this + + align:start position:0% +what they found later on is that in this + + + align:start position:0% +what they found later on is that in this +material + + align:start position:0% +material + + + align:start position:0% +material +actually even though it's a single + + align:start position:0% +actually even though it's a single + + + align:start position:0% +actually even though it's a single +Crystal but a lot of precipi are from n + + align:start position:0% +Crystal but a lot of precipi are from n + + + align:start position:0% +Crystal but a lot of precipi are from n +Dot and uh and with that the his is also + + align:start position:0% +Dot and uh and with that the his is also + + + align:start position:0% +Dot and uh and with that the his is also +low so we got a a good uh + + align:start position:0% + + + + align:start position:0% + +figure this is a really interesting + + align:start position:0% +figure this is a really interesting + + + align:start position:0% +figure this is a really interesting +system uh I've been talking to je + + align:start position:0% +system uh I've been talking to je + + + align:start position:0% +system uh I've been talking to je +paramas + + align:start position:0% +paramas + + + align:start position:0% +paramas +uh and I still can really give you very + + align:start position:0% +uh and I still can really give you very + + + align:start position:0% +uh and I still can really give you very +simple picture and it's a uh basically + + align:start position:0% +simple picture and it's a uh basically + + + align:start position:0% +simple picture and it's a uh basically +uh I give me a very simple picture so I + + align:start position:0% +uh I give me a very simple picture so I + + + align:start position:0% +uh I give me a very simple picture so I +can exp my students and uh I don't think + + align:start position:0% +can exp my students and uh I don't think + + + align:start position:0% +can exp my students and uh I don't think +I got his simple picture yet uh but the + + align:start position:0% +I got his simple picture yet uh but the + + + align:start position:0% +I got his simple picture yet uh but the +the idea is looking at is uh here is a + + align:start position:0% +the idea is looking at is uh here is a + + + align:start position:0% +the idea is looking at is uh here is a +silver uh site by site it's cuic + + align:start position:0% +silver uh site by site it's cuic + + + align:start position:0% +silver uh site by site it's cuic +structure right so right all those are + + align:start position:0% +structure right so right all those are + + + align:start position:0% +structure right so right all those are +similar and uh one is see is uh the + + align:start position:0% +similar and uh one is see is uh the + + + align:start position:0% +similar and uh one is see is uh the +electron clouds between the atoms + + align:start position:0% +electron clouds between the atoms + + + align:start position:0% +electron clouds between the atoms +uh have overlap and when one set of atom + + align:start position:0% +uh have overlap and when one set of atom + + + align:start position:0% +uh have overlap and when one set of atom +is moving let squeeze this CL clouds + + align:start position:0% +is moving let squeeze this CL clouds + + + align:start position:0% +is moving let squeeze this CL clouds +very significant so electron CLA very + + align:start position:0% +very significant so electron CLA very + + + align:start position:0% +very significant so electron CLA very +significant squeezing cause the the + + align:start position:0% +significant squeezing cause the the + + + align:start position:0% +significant squeezing cause the the +force UNH + + align:start position:0% +force UNH + + + align:start position:0% +force UNH +harmonis and this + + align:start position:0% +harmonis and this + + + align:start position:0% +harmonis and this +anharmonicity gives a very low so what + + align:start position:0% +anharmonicity gives a very low so what + + + align:start position:0% +anharmonicity gives a very low so what +you want is you want to make the atom + + align:start position:0% +you want is you want to make the atom + + + align:start position:0% +you want is you want to make the atom +strongly scatter each other okay uh High + + align:start position:0% +strongly scatter each other okay uh High + + + align:start position:0% +strongly scatter each other okay uh High +connectivity is you just have a pure + + align:start position:0% +connectivity is you just have a pure + + + align:start position:0% +connectivity is you just have a pure +Sprint honic oscillator you have + + align:start position:0% +Sprint honic oscillator you have + + + align:start position:0% +Sprint honic oscillator you have +infinite thermal + + align:start position:0% +infinite thermal + + + align:start position:0% +infinite thermal +conductivity and this the final thermal + + align:start position:0% +conductivity and this the final thermal + + + align:start position:0% +conductivity and this the final thermal +connectivity really comes from the third + + align:start position:0% +connectivity really comes from the third + + + align:start position:0% +connectivity really comes from the third +term of the potential okay it's not fals + + align:start position:0% +term of the potential okay it's not fals + + + align:start position:0% +term of the potential okay it's not fals +KX is for FAL KX plus perturbation KX + + align:start position:0% +KX is for FAL KX plus perturbation KX + + + align:start position:0% +KX is for FAL KX plus perturbation KX +squ so that square makees the two + + align:start position:0% +squ so that square makees the two + + + align:start position:0% +squ so that square makees the two +different frequency W interact with each + + align:start position:0% +different frequency W interact with each + + + align:start position:0% +different frequency W interact with each +other that's so hard for optical wave + + align:start position:0% +other that's so hard for optical wave + + + align:start position:0% +other that's so hard for optical wave +it's much easier for f but when you want + + align:start position:0% +it's much easier for f but when you want + + + align:start position:0% +it's much easier for f but when you want +to push to very low uh very small limit + + align:start position:0% +to push to very low uh very small limit + + + align:start position:0% +to push to very low uh very small limit +you got to say get this aity very large + + align:start position:0% +you got to say get this aity very large + + + align:start position:0% +you got to say get this aity very large +and one way to to gaug that is this + + align:start position:0% +and one way to to gaug that is this + + + align:start position:0% +and one way to to gaug that is this +reason parameter which is related to + + align:start position:0% +reason parameter which is related to + + + align:start position:0% +reason parameter which is related to +theral expansion and theral expansion so + + align:start position:0% +theral expansion and theral expansion so + + + align:start position:0% +theral expansion and theral expansion so +higher large th expansion material + + align:start position:0% +higher large th expansion material + + + align:start position:0% +higher large th expansion material +typically is more + + align:start position:0% +typically is more + + + align:start position:0% +typically is more +unod + + align:start position:0% +unod + + + align:start position:0% +unod +okay and uh what is showing is this + + align:start position:0% +okay and uh what is showing is this + + + align:start position:0% +okay and uh what is showing is this +minimum theral conductivity Theory uh + + align:start position:0% +minimum theral conductivity Theory uh + + + align:start position:0% +minimum theral conductivity Theory uh +that's also another thing I never + + align:start position:0% +that's also another thing I never + + + align:start position:0% +that's also another thing I never +believe minimum Ser contivity uh what + + align:start position:0% +believe minimum Ser contivity uh what + + + align:start position:0% +believe minimum Ser contivity uh what +the idea is one thir K 1 c v gamma right + + align:start position:0% +the idea is one thir K 1 c v gamma right + + + align:start position:0% +the idea is one thir K 1 c v gamma right +that's the ktic theory and the minimum + + align:start position:0% +that's the ktic theory and the minimum + + + align:start position:0% +that's the ktic theory and the minimum +server conductivity is replacing the + + align:start position:0% +server conductivity is replacing the + + + align:start position:0% +server conductivity is replacing the +mean free pass by the + + align:start position:0% +mean free pass by the + + + align:start position:0% +mean free pass by the +wavelength okay so that's the minimum + + align:start position:0% +wavelength okay so that's the minimum + + + align:start position:0% +wavelength okay so that's the minimum +mean free pass you could have and this + + align:start position:0% +mean free pass you could have and this + + + align:start position:0% +mean free pass you could have and this +was a glen slack originary Theory and + + align:start position:0% +was a glen slack originary Theory and + + + align:start position:0% +was a glen slack originary Theory and +then + + align:start position:0% +then + + + align:start position:0% +then +and Bobby Paul from uh Corel uh said + + align:start position:0% +and Bobby Paul from uh Corel uh said + + + align:start position:0% +and Bobby Paul from uh Corel uh said +that oh you should not be just mean free + + align:start position:0% +that oh you should not be just mean free + + + align:start position:0% +that oh you should not be just mean free +pass equals wance it should be mean free + + align:start position:0% +pass equals wance it should be mean free + + + align:start position:0% +pass equals wance it should be mean free +pass equals half wance Einstein based on + + align:start position:0% +pass equals half wance Einstein based on + + + align:start position:0% +pass equals half wance Einstein based on +Einstein the + + align:start position:0% +Einstein the + + + align:start position:0% +Einstein the +argument so that reduce th minimum by + + align:start position:0% +argument so that reduce th minimum by + + + align:start position:0% +argument so that reduce th minimum by +another half and so very often people + + align:start position:0% +another half and so very often people + + + align:start position:0% +another half and so very often people +will draw theal connectivity against + + align:start position:0% +will draw theal connectivity against + + + align:start position:0% +will draw theal connectivity against +minimum so this is the one example say + + align:start position:0% +minimum so this is the one example say + + + align:start position:0% +minimum so this is the one example say +okay you reach the minimum you can + + align:start position:0% +okay you reach the minimum you can + + + align:start position:0% +okay you reach the minimum you can +reduce + + align:start position:0% +reduce + + + align:start position:0% +reduce +anymore but in fact I said D key help + + align:start position:0% +anymore but in fact I said D key help + + + align:start position:0% +anymore but in fact I said D key help +because he measur layer structure his + + align:start position:0% +because he measur layer structure his + + + align:start position:0% +because he measur layer structure his +server connectivity is twice air it's + + align:start position:0% +server connectivity is twice air it's + + + align:start position:0% +server connectivity is twice air it's +order magnitude smaller than the minimum + + align:start position:0% +order magnitude smaller than the minimum + + + align:start position:0% +order magnitude smaller than the minimum +so his own minimal Theory now there's a + + align:start position:0% +so his own minimal Theory now there's a + + + align:start position:0% +so his own minimal Theory now there's a +minimal experiment as an order Corner + + align:start position:0% +minimal experiment as an order Corner + + + align:start position:0% +minimal experiment as an order Corner +that's why I say I don't believe in the + + align:start position:0% +that's why I say I don't believe in the + + + align:start position:0% +that's why I say I don't believe in the +because you should go uh look at that + + align:start position:0% +because you should go uh look at that + + + align:start position:0% +because you should go uh look at that +there better formulation when you have + + align:start position:0% +there better formulation when you have + + + align:start position:0% +there better formulation when you have +iron s you don't you don't have one3 + + align:start position:0% +iron s you don't you don't have one3 + + + align:start position:0% +iron s you don't you don't have one3 +M if you're interested this point + + align:start position:0% + + + + align:start position:0% + +to okay this is something that uh I + + align:start position:0% +to okay this is something that uh I + + + align:start position:0% +to okay this is something that uh I +really want I said I have okay I bring + + align:start position:0% +really want I said I have okay I bring + + + align:start position:0% +really want I said I have okay I bring +you from the basics to really the + + align:start position:0% +you from the basics to really the + + + align:start position:0% +you from the basics to really the +Forefront that's just a few uh uh month + + align:start position:0% +Forefront that's just a few uh uh month + + + align:start position:0% +Forefront that's just a few uh uh month +ago there was paper um uh Indian + + align:start position:0% +ago there was paper um uh Indian + + + align:start position:0% +ago there was paper um uh Indian +uh + + align:start position:0% +uh + + + align:start position:0% +uh +satellite and uh what is the saying this + + align:start position:0% +satellite and uh what is the saying this + + + align:start position:0% +satellite and uh what is the saying this +is this is a charge + + align:start position:0% +is this is a charge + + + align:start position:0% +is this is a charge +density and the PES + + align:start position:0% +density and the PES + + + align:start position:0% +density and the PES +instability and this this got really uh + + align:start position:0% +instability and this this got really uh + + + align:start position:0% +instability and this this got really uh +uh so uh but let me f uh so what what + + align:start position:0% +uh so uh but let me f uh so what what + + + align:start position:0% +uh so uh but let me f uh so what what +happens is uh this direction is wward + + align:start position:0% +happens is uh this direction is wward + + + align:start position:0% +happens is uh this direction is wward +for that's more like a layer structure + + align:start position:0% +for that's more like a layer structure + + + align:start position:0% +for that's more like a layer structure +and then into the C axis that's the uh + + align:start position:0% +and then into the C axis that's the uh + + + align:start position:0% +and then into the C axis that's the uh +uh see calent bonding but because the uh + + align:start position:0% +uh see calent bonding but because the uh + + + align:start position:0% +uh see calent bonding but because the uh +uh charge Distortion so in the C axis + + align:start position:0% +uh charge Distortion so in the C axis + + + align:start position:0% +uh charge Distortion so in the C axis +this actually charg is strongly + + align:start position:0% +this actually charg is strongly + + + align:start position:0% +this actually charg is strongly +distorted and create a very large ANH + + align:start position:0% +distorted and create a very large ANH + + + align:start position:0% +distorted and create a very large ANH +harmonicity to the L W scatter so the + + align:start position:0% +harmonicity to the L W scatter so the + + + align:start position:0% +harmonicity to the L W scatter so the +theral conductivity is really strange + + align:start position:0% +theral conductivity is really strange + + + align:start position:0% +theral conductivity is really strange +because the onear direction Force weak + + align:start position:0% +because the onear direction Force weak + + + align:start position:0% +because the onear direction Force weak +Force typically means low th contivity + + align:start position:0% +Force typically means low th contivity + + + align:start position:0% +Force typically means low th contivity +right but in this case what you have + + align:start position:0% +right but in this case what you have + + + align:start position:0% +right but in this case what you have +this is the CX coent Direction has lower + + align:start position:0% +this is the CX coent Direction has lower + + + align:start position:0% +this is the CX coent Direction has lower +C + + align:start position:0% +C + + + align:start position:0% +C +the and very interesting uh uh and + + align:start position:0% +the and very interesting uh uh and + + + align:start position:0% +the and very interesting uh uh and +definitely wor more study + + align:start position:0% + + + + align:start position:0% + +here okay now let me go to m + + align:start position:0% +here okay now let me go to m + + + align:start position:0% +here okay now let me go to m +side right uh this is the quantization + + align:start position:0% +side right uh this is the quantization + + + align:start position:0% +side right uh this is the quantization +menion and uh uh the pza Box problem + + align:start position:0% +menion and uh uh the pza Box problem + + + align:start position:0% +menion and uh uh the pza Box problem +right the + + align:start position:0% +right the + + + align:start position:0% +right the +possible so you have a simple uh see + + align:start position:0% +possible so you have a simple uh see + + + align:start position:0% +possible so you have a simple uh see +this is a simple homework I said before + + align:start position:0% +this is a simple homework I said before + + + align:start position:0% +this is a simple homework I said before +uh the uh this is the Z Direction energy + + align:start position:0% +uh the uh this is the Z Direction energy + + + align:start position:0% +uh the uh this is the Z Direction energy +cont and you can do the same standing + + align:start position:0% +cont and you can do the same standing + + + align:start position:0% +cont and you can do the same standing +wave argument I did before and say + + align:start position:0% +wave argument I did before and say + + + align:start position:0% +wave argument I did before and say +what's the wavelength and what's the + + align:start position:0% +what's the wavelength and what's the + + + align:start position:0% +what's the wavelength and what's the +corresponding + + align:start position:0% +corresponding + + + align:start position:0% +corresponding +energy and uh uh so x y direction the is + + align:start position:0% +energy and uh uh so x y direction the is + + + align:start position:0% +energy and uh uh so x y direction the is +qu continuous W Vector so now for + + align:start position:0% +qu continuous W Vector so now for + + + align:start position:0% +qu continuous W Vector so now for +different end uh we have the sub bance + + align:start position:0% +different end uh we have the sub bance + + + align:start position:0% +different end uh we have the sub bance +so this energy P + + align:start position:0% +so this energy P + + + align:start position:0% +so this energy P +has different energy levels in the due + + align:start position:0% +has different energy levels in the due + + + align:start position:0% +has different energy levels in the due +to the uh thickness in the direction so + + align:start position:0% +to the uh thickness in the direction so + + + align:start position:0% +to the uh thickness in the direction so +that's a basic F Well idea okay and now + + align:start position:0% +that's a basic F Well idea okay and now + + + align:start position:0% +that's a basic F Well idea okay and now +you go to do + + align:start position:0% +you go to do + + + align:start position:0% +you go to do +this uh you calculate the density of + + align:start position:0% +this uh you calculate the density of + + + align:start position:0% +this uh you calculate the density of +space I I uh I don't want to go through + + align:start position:0% +space I I uh I don't want to go through + + + align:start position:0% +space I I uh I don't want to go through +this MTH but you can say this is the the + + align:start position:0% +this MTH but you can say this is the the + + + align:start position:0% +this MTH but you can say this is the the +same thing we did before except in the + + align:start position:0% +same thing we did before except in the + + + align:start position:0% +same thing we did before except in the +direction now I don't do uh I do not + + align:start position:0% +direction now I don't do uh I do not + + + align:start position:0% +direction now I don't do uh I do not +convert this summation into into + + align:start position:0% +convert this summation into into + + + align:start position:0% +convert this summation into into +integration in Z Direction I convert the + + align:start position:0% +integration in Z Direction I convert the + + + align:start position:0% +integration in Z Direction I convert the +XY Direction because the direction that + + align:start position:0% +XY Direction because the direction that + + + align:start position:0% +XY Direction because the direction that +separation is too large and the the + + align:start position:0% +separation is too large and the the + + + align:start position:0% +separation is too large and the the +summation to integration that conversion + + align:start position:0% +summation to integration that conversion + + + align:start position:0% +summation to integration that conversion +is not rigorous not mathematically + + align:start position:0% +is not rigorous not mathematically + + + align:start position:0% +is not rigorous not mathematically +accurate so I still keep this summation + + align:start position:0% +accurate so I still keep this summation + + + align:start position:0% +accurate so I still keep this summation +here and at the end what you show is + + align:start position:0% +here and at the end what you show is + + + align:start position:0% +here and at the end what you show is +density of States now is a + + align:start position:0% +density of States now is a + + + align:start position:0% +density of States now is a +staircase uh or in typical parabolic + + align:start position:0% +staircase uh or in typical parabolic + + + align:start position:0% +staircase uh or in typical parabolic +band approximation we got this is 3D + + align:start position:0% +band approximation we got this is 3D + + + align:start position:0% +band approximation we got this is 3D +this is + + align:start position:0% +this is + + + align:start position:0% +this is +2D okay and now with that there's + + align:start position:0% +2D okay and now with that there's + + + align:start position:0% +2D okay and now with that there's +Advantage where is the + + align:start position:0% +Advantage where is the + + + align:start position:0% +Advantage where is the +advantage let's go back to the picture I + + align:start position:0% +advantage let's go back to the picture I + + + align:start position:0% +advantage let's go back to the picture I +show before right see back in the + + align:start position:0% +show before right see back in the + + + align:start position:0% +show before right see back in the +measure of the average energy of the + + align:start position:0% +measure of the average energy of the + + + align:start position:0% +measure of the average energy of the +electron relative chical potential + + align:start position:0% + + + + align:start position:0% + +the number the electron electric + + align:start position:0% +the number the electron electric + + + align:start position:0% +the number the electron electric +conductivity is really proportional to + + align:start position:0% +conductivity is really proportional to + + + align:start position:0% +conductivity is really proportional to +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +electrons right now when I have this if + + align:start position:0% +electrons right now when I have this if + + + align:start position:0% +electrons right now when I have this if +you look at this is den of States this + + align:start position:0% +you look at this is den of States this + + + align:start position:0% +you look at this is den of States this +is DF per direct derivative now this is + + align:start position:0% +is DF per direct derivative now this is + + + align:start position:0% +is DF per direct derivative now this is +very small this this times this that's + + align:start position:0% +very small this this times this that's + + + align:start position:0% +very small this this times this that's +the region where it's contributing to + + align:start position:0% +the region where it's contributing to + + + align:start position:0% +the region where it's contributing to +electrons right because of the parabolic + + align:start position:0% +electrons right because of the parabolic + + + align:start position:0% +electrons right because of the parabolic +this is a small L time small + + align:start position:0% +this is a small L time small + + + align:start position:0% +this is a small L time small +l so the electric conduction the number + + align:start position:0% +l so the electric conduction the number + + + align:start position:0% +l so the electric conduction the number +of + + align:start position:0% +of + + + align:start position:0% +of +charges that carry this C back most of + + align:start position:0% +charges that carry this C back most of + + + align:start position:0% +charges that carry this C back most of +them is very low energy the average + + align:start position:0% +them is very low energy the average + + + align:start position:0% +them is very low energy the average +energy is here those are low energy + + align:start position:0% +energy is here those are low energy + + + align:start position:0% +energy is here those are low energy +electron they carry more electrical + + align:start position:0% +electron they carry more electrical + + + align:start position:0% +electron they carry more electrical +charge so that's a problem with + + align:start position:0% +charge so that's a problem with + + + align:start position:0% +charge so that's a problem with +parabolic than with the density the + + align:start position:0% +parabolic than with the density the + + + align:start position:0% +parabolic than with the density the +parabolic density of + + align:start position:0% +parabolic density of + + + align:start position:0% +parabolic density of +stat okay now do the conent right you + + align:start position:0% +stat okay now do the conent right you + + + align:start position:0% +stat okay now do the conent right you +have a sharp + + align:start position:0% +have a sharp + + + align:start position:0% +have a sharp +staircase and uh you can put in you see + + align:start position:0% +staircase and uh you can put in you see + + + align:start position:0% +staircase and uh you can put in you see +here you can put in more charge or still + + align:start position:0% +here you can put in more charge or still + + + align:start position:0% +here you can put in more charge or still +have the same + + align:start position:0% +have the same + + + align:start position:0% +have the same +SE or if you have S electric + + align:start position:0% +SE or if you have S electric + + + align:start position:0% +SE or if you have S electric +conductivity they you then you can + + align:start position:0% +conductivity they you then you can + + + align:start position:0% +conductivity they you then you can +increase your + + align:start position:0% +increase your + + + align:start position:0% +increase your +C at the end what you want is s sare + + align:start position:0% +C at the end what you want is s sare + + + align:start position:0% +C at the end what you want is s sare +Sigma to be larger right so that's why + + align:start position:0% +Sigma to be larger right so that's why + + + align:start position:0% +Sigma to be larger right so that's why +why those Quantum structures like the + + align:start position:0% +why those Quantum structures like the + + + align:start position:0% +why those Quantum structures like the +quantum Wells gave you larger s Square + + align:start position:0% +quantum Wells gave you larger s Square + + + align:start position:0% +quantum Wells gave you larger s Square +Sigma and then you look at the other + + align:start position:0% +Sigma and then you look at the other + + + align:start position:0% +Sigma and then you look at the other +structures the D of States this is the + + align:start position:0% +structures the D of States this is the + + + align:start position:0% +structures the D of States this is the +Ser case for the uh two dimensional and + + align:start position:0% +Ser case for the uh two dimensional and + + + align:start position:0% +Ser case for the uh two dimensional and +then + + align:start position:0% +then + + + align:start position:0% +then +wires is a sharp Pi here and dots are + + align:start position:0% +wires is a sharp Pi here and dots are + + + align:start position:0% +wires is a sharp Pi here and dots are +just discrete + + align:start position:0% +just discrete + + + align:start position:0% +just discrete +lines + + align:start position:0% +lines + + + align:start position:0% +lines +so progressively going from 3D 2D 1D z d + + align:start position:0% +so progressively going from 3D 2D 1D z d + + + align:start position:0% +so progressively going from 3D 2D 1D z d +it's better progressively it's better + + align:start position:0% +it's better progressively it's better + + + align:start position:0% +it's better progressively it's better +okay so that's what the theory says and + + align:start position:0% +okay so that's what the theory says and + + + align:start position:0% +okay so that's what the theory says and +at the time Milly and uh Ham N lab did + + align:start position:0% +at the time Milly and uh Ham N lab did + + + align:start position:0% +at the time Milly and uh Ham N lab did +the + + align:start position:0% +the + + + align:start position:0% +the +experiment and uh uh they show that that + + align:start position:0% +experiment and uh uh they show that that + + + align:start position:0% +experiment and uh uh they show that that +this but I don't I want first to show + + align:start position:0% +this but I don't I want first to show + + + align:start position:0% +this but I don't I want first to show +the trend right except there's one + + align:start position:0% +the trend right except there's one + + + align:start position:0% +the trend right except there's one +cop you see there + + align:start position:0% + + + + align:start position:0% + +this is not s squ Sigma this is s squ n + + align:start position:0% +this is not s squ Sigma this is s squ n + + + align:start position:0% +this is not s squ Sigma this is s squ n +right electric conductivity is n time + + align:start position:0% +right electric conductivity is n time + + + align:start position:0% +right electric conductivity is n time +Mobility + + align:start position:0% +Mobility + + + align:start position:0% +Mobility +times the carrier charge electron + + align:start position:0% +times the carrier charge electron + + + align:start position:0% +times the carrier charge electron +charge okay and what what's the reason + + align:start position:0% +charge okay and what what's the reason + + + align:start position:0% +charge okay and what what's the reason +is that the super was not the the + + align:start position:0% +is that the super was not the the + + + align:start position:0% +is that the super was not the the +quantum W was not very good interface + + align:start position:0% +quantum W was not very good interface + + + align:start position:0% +quantum W was not very good interface +scal + + align:start position:0% +scal + + + align:start position:0% +scal +electrons Electric conductiv + + align:start position:0% +electrons Electric conductiv + + + align:start position:0% +electrons Electric conductiv +if you PL uh that I don't I don't know + + align:start position:0% +if you PL uh that I don't I don't know + + + align:start position:0% +if you PL uh that I don't I don't know +the detail but let see uh there are + + align:start position:0% +the detail but let see uh there are + + + align:start position:0% +the detail but let see uh there are +still questions here right because you + + align:start position:0% +still questions here right because you + + + align:start position:0% +still questions here right because you +this is s Square Sigma s Square n not s + + align:start position:0% +this is s Square Sigma s Square n not s + + + align:start position:0% +this is s Square Sigma s Square n not s +squ Sigma but the trend is there and + + align:start position:0% +squ Sigma but the trend is there and + + + align:start position:0% +squ Sigma but the trend is there and +that generate a lot of + + align:start position:0% + + + + align:start position:0% + +interest and uh this is just a more + + align:start position:0% +interest and uh this is just a more + + + align:start position:0% +interest and uh this is just a more +calculation I + + align:start position:0% +calculation I + + + align:start position:0% +calculation I +took from a book that Jo Paras and + + align:start position:0% +took from a book that Jo Paras and + + + align:start position:0% +took from a book that Jo Paras and +myself wri we never have finished finish + + align:start position:0% +myself wri we never have finished finish + + + align:start position:0% +myself wri we never have finished finish +this + + align:start position:0% +this + + + align:start position:0% +this +but anyone want to read there gra 3D 2D + + align:start position:0% +but anyone want to read there gra 3D 2D + + + align:start position:0% +but anyone want to read there gra 3D 2D +1D progressiv is + + align:start position:0% +1D progressiv is + + + align:start position:0% +1D progressiv is +better uh that's a theory and to do it + + align:start position:0% +better uh that's a theory and to do it + + + align:start position:0% +better uh that's a theory and to do it +in the experiment like I said you you + + align:start position:0% +in the experiment like I said you you + + + align:start position:0% +in the experiment like I said you you +can't scatter electrons you have to be + + align:start position:0% +can't scatter electrons you have to be + + + align:start position:0% +can't scatter electrons you have to be +very careful right so + + align:start position:0% +very careful right so + + + align:start position:0% +very careful right so +um and there's another problem okay so + + align:start position:0% +um and there's another problem okay so + + + align:start position:0% +um and there's another problem okay so +of course superl is uh well is just the + + align:start position:0% +of course superl is uh well is just the + + + align:start position:0% +of course superl is uh well is just the +film that's conducting electron + + align:start position:0% +film that's conducting electron + + + align:start position:0% +film that's conducting electron +and uh the problem is you have to + + align:start position:0% +and uh the problem is you have to + + + align:start position:0% +and uh the problem is you have to +sandwich this right or you can use air + + align:start position:0% +sandwich this right or you can use air + + + align:start position:0% +sandwich this right or you can use air +or vacuum or Quon wire in vacuum then + + align:start position:0% +or vacuum or Quon wire in vacuum then + + + align:start position:0% +or vacuum or Quon wire in vacuum then +there's no + + align:start position:0% +there's no + + + align:start position:0% +there's no +leakage but see normally when you use + + align:start position:0% +leakage but see normally when you use + + + align:start position:0% +leakage but see normally when you use +another materal to create a barrier to + + align:start position:0% +another materal to create a barrier to + + + align:start position:0% +another materal to create a barrier to +confine electron in the film then you + + align:start position:0% +confine electron in the film then you + + + align:start position:0% +confine electron in the film then you +got a colons in this + + align:start position:0% +got a colons in this + + + align:start position:0% +got a colons in this +barrier forance in this varus will kill + + align:start position:0% +barrier forance in this varus will kill + + + align:start position:0% +barrier forance in this varus will kill +your conduction right so kill your + + align:start position:0% +your conduction right so kill your + + + align:start position:0% +your conduction right so kill your +create a more Lage + + align:start position:0% +create a more Lage + + + align:start position:0% +create a more Lage +there and there are solutions on this + + align:start position:0% +there and there are solutions on this + + + align:start position:0% +there and there are solutions on this +theoretically I worked with M uh on this + + align:start position:0% +theoretically I worked with M uh on this + + + align:start position:0% +theoretically I worked with M uh on this +before uh let's say uh just the CIA one + + align:start position:0% +before uh let's say uh just the CIA one + + + align:start position:0% +before uh let's say uh just the CIA one +has to pay attention for example uh + + align:start position:0% +has to pay attention for example uh + + + align:start position:0% +has to pay attention for example uh +there are also also study by Jer and + + align:start position:0% +there are also also study by Jer and + + + align:start position:0% +there are also also study by Jer and +others say if you reduce the sickness + + align:start position:0% +others say if you reduce the sickness + + + align:start position:0% +others say if you reduce the sickness +okay you want to reduce barrier hequ you + + align:start position:0% +okay you want to reduce barrier hequ you + + + align:start position:0% +okay you want to reduce barrier hequ you +reduce sickness and then the different + + align:start position:0% +reduce sickness and then the different + + + align:start position:0% +reduce sickness and then the different +then you have another qu this two start + + align:start position:0% +then you have another qu this two start + + + align:start position:0% +then you have another qu this two start +talking to each other colony and that + + align:start position:0% +talking to each other colony and that + + + align:start position:0% +talking to each other colony and that +Colony actually is not good that can uh + + align:start position:0% +Colony actually is not good that can uh + + + align:start position:0% +Colony actually is not good that can uh +the uh the den stat become less sharper + + align:start position:0% +the uh the den stat become less sharper + + + align:start position:0% +the uh the den stat become less sharper +than uh the pure Quant we is there are + + align:start position:0% +than uh the pure Quant we is there are + + + align:start position:0% +than uh the pure Quant we is there are +there are potential Solutions uh I + + align:start position:0% +there are potential Solutions uh I + + + align:start position:0% +there are potential Solutions uh I +encourage you read the literature M and + + align:start position:0% +encourage you read the literature M and + + + align:start position:0% +encourage you read the literature M and +work on + + align:start position:0% +work on + + + align:start position:0% +work on +this but turns + + align:start position:0% +this but turns + + + align:start position:0% +this but turns +out this general idea of sh feature in + + align:start position:0% +out this general idea of sh feature in + + + align:start position:0% +out this general idea of sh feature in +den of + + align:start position:0% +den of + + + align:start position:0% +den of +States is Universal not only in th films + + align:start position:0% +States is Universal not only in th films + + + align:start position:0% +States is Universal not only in th films +but in both + + align:start position:0% +but in both + + + align:start position:0% +but in both +materials and uh there was a one paper + + align:start position:0% +materials and uh there was a one paper + + + align:start position:0% +materials and uh there was a one paper +by + + align:start position:0% +by + + + align:start position:0% +by +Jeran and uh he wrote a paper around 97 + + align:start position:0% +Jeran and uh he wrote a paper around 97 + + + align:start position:0% +Jeran and uh he wrote a paper around 97 +and he did he is he's a very good + + align:start position:0% +and he did he is he's a very good + + + align:start position:0% +and he did he is he's a very good +theoretician he just took a simple math + + align:start position:0% +theoretician he just took a simple math + + + align:start position:0% +theoretician he just took a simple math +problem he said I'm going to optimize + + align:start position:0% +problem he said I'm going to optimize + + + align:start position:0% +problem he said I'm going to optimize +thiss of States just write the + + align:start position:0% +thiss of States just write the + + + align:start position:0% +thiss of States just write the +expression I wrote before treat as a + + align:start position:0% +expression I wrote before treat as a + + + align:start position:0% +expression I wrote before treat as a +functional that D this sub stat as a + + align:start position:0% +functional that D this sub stat as a + + + align:start position:0% +functional that D this sub stat as a +functional mathematics what's the + + align:start position:0% +functional mathematics what's the + + + align:start position:0% +functional mathematics what's the +functional that will give you maximum s + + align:start position:0% +functional that will give you maximum s + + + align:start position:0% +functional that will give you maximum s +s Sigma or give you maximum ZT and at + + align:start position:0% +s Sigma or give you maximum ZT and at + + + align:start position:0% +s Sigma or give you maximum ZT and at +the end he conclud this Delta + + align:start position:0% +the end he conclud this Delta + + + align:start position:0% +the end he conclud this Delta +function okay so Delta function is the + + align:start position:0% +function okay so Delta function is the + + + align:start position:0% +function okay so Delta function is the +best and if you go back to what I show + + align:start position:0% +best and if you go back to what I show + + + align:start position:0% +best and if you go back to what I show +here quum dot is best except the + + align:start position:0% +here quum dot is best except the + + + align:start position:0% +here quum dot is best except the +electron what how you going move quom + + align:start position:0% +electron what how you going move quom + + + align:start position:0% +electron what how you going move quom +dots electron going to except the delta + + align:start position:0% +dots electron going to except the delta + + + align:start position:0% +dots electron going to except the delta +T over quom dots right + + align:start position:0% +T over quom dots right + + + align:start position:0% +T over quom dots right +so wire is is is also good so this is + + align:start position:0% +so wire is is is also good so this is + + + align:start position:0% +so wire is is is also good so this is +General principle another interesting + + align:start position:0% +General principle another interesting + + + align:start position:0% +General principle another interesting +comment I want to make is you go to + + align:start position:0% +comment I want to make is you go to + + + align:start position:0% +comment I want to make is you go to +check the Lawrence Lum uh and that's + + align:start position:0% +check the Lawrence Lum uh and that's + + + align:start position:0% +check the Lawrence Lum uh and that's +what I suspected the Lawrence number in + + align:start position:0% +what I suspected the Lawrence number in + + + align:start position:0% +what I suspected the Lawrence number in +Quantum do can be + + align:start position:0% +Quantum do can be + + + align:start position:0% +Quantum do can be +zero very strange nobody demonstrated + + align:start position:0% +zero very strange nobody demonstrated + + + align:start position:0% +zero very strange nobody demonstrated +that okay it very will be interesting + + align:start position:0% +that okay it very will be interesting + + + align:start position:0% +that okay it very will be interesting +experiment electric + + align:start position:0% +experiment electric + + + align:start position:0% +experiment electric +conductivity is not zero but the + + align:start position:0% +conductivity is not zero but the + + + align:start position:0% +conductivity is not zero but the +electronic thermal conductivity is zero + + align:start position:0% +electronic thermal conductivity is zero + + + align:start position:0% +electronic thermal conductivity is zero +very easy to + + align:start position:0% +very easy to + + + align:start position:0% +very easy to +check okay let me go here so so this is + + align:start position:0% +check okay let me go here so so this is + + + align:start position:0% +check okay let me go here so so this is +really recent + + align:start position:0% +really recent + + + align:start position:0% +really recent +Herman and he said weing we talk a lot + + align:start position:0% +Herman and he said weing we talk a lot + + + align:start position:0% +Herman and he said weing we talk a lot +but the very smart guy and he + + align:start position:0% +but the very smart guy and he + + + align:start position:0% +but the very smart guy and he +say uh he worked on Nano Nano work with + + align:start position:0% +say uh he worked on Nano Nano work with + + + align:start position:0% +say uh he worked on Nano Nano work with +million say I'm going to turn to B mat + + align:start position:0% +million say I'm going to turn to B mat + + + align:start position:0% +million say I'm going to turn to B mat +so he when they uh he he read Russian + + align:start position:0% +so he when they uh he he read Russian + + + align:start position:0% +so he when they uh he he read Russian +literature and this all actually in + + align:start position:0% +literature and this all actually in + + + align:start position:0% +literature and this all actually in +Russian literature it turns out there + + align:start position:0% +Russian literature it turns out there + + + align:start position:0% +Russian literature it turns out there +are some + + align:start position:0% +are some + + + align:start position:0% +are some +doping when we think about doping we + + align:start position:0% +doping when we think about doping we + + + align:start position:0% +doping when we think about doping we +think about doping the energy level is + + align:start position:0% +think about doping the energy level is + + + align:start position:0% +think about doping the energy level is +inside the b in the uh Bank Gap but + + align:start position:0% +inside the b in the uh Bank Gap but + + + align:start position:0% +inside the b in the uh Bank Gap but +there are some other atoms you dop it + + align:start position:0% +there are some other atoms you dop it + + + align:start position:0% +there are some other atoms you dop it +the dopen level is within the conduction + + align:start position:0% +the dopen level is within the conduction + + + align:start position:0% +the dopen level is within the conduction +of Valance B and in this case is in the + + align:start position:0% +of Valance B and in this case is in the + + + align:start position:0% +of Valance B and in this case is in the +viance band and this viance band they + + align:start position:0% +viance band and this viance band they + + + align:start position:0% +viance band and this viance band they +don't the form additional energy state + + align:start position:0% +don't the form additional energy state + + + align:start position:0% +don't the form additional energy state +that create a Shar feature in the + + align:start position:0% +that create a Shar feature in the + + + align:start position:0% +that create a Shar feature in the +density of + + align:start position:0% +density of + + + align:start position:0% +density of +state and this Shar feature led to a + + align:start position:0% +state and this Shar feature led to a + + + align:start position:0% +state and this Shar feature led to a +very good C coefficient and a very high + + align:start position:0% + + + + align:start position:0% + +C the question is you whether you can + + align:start position:0% +C the question is you whether you can + + + align:start position:0% +C the question is you whether you can +replicate in different + + align:start position:0% +replicate in different + + + align:start position:0% +replicate in different +materials without nobody wants to touch + + align:start position:0% +materials without nobody wants to touch + + + align:start position:0% +materials without nobody wants to touch +it okay a very poison uh uh because say + + align:start position:0% +it okay a very poison uh uh because say + + + align:start position:0% +it okay a very poison uh uh because say +it's not that terrible I have a friend + + align:start position:0% +it's not that terrible I have a friend + + + align:start position:0% +it's not that terrible I have a friend +that he said I work with son for more + + align:start position:0% +that he said I work with son for more + + + align:start position:0% +that he said I work with son for more +than 15 years Super conductor and uh + + align:start position:0% +than 15 years Super conductor and uh + + + align:start position:0% +than 15 years Super conductor and uh +nothing happened but but uh of + + align:start position:0% +nothing happened but but uh of + + + align:start position:0% +nothing happened but but uh of +course + + align:start position:0% +course + + + align:start position:0% +course +careful now this is another + + align:start position:0% +careful now this is another + + + align:start position:0% +careful now this is another +idea uh I think again come back to uh + + align:start position:0% +idea uh I think again come back to uh + + + align:start position:0% +idea uh I think again come back to uh +the uh you can interpret the same as + + align:start position:0% +the uh you can interpret the same as + + + align:start position:0% +the uh you can interpret the same as +dens of State this is a Okay C efficient + + align:start position:0% +dens of State this is a Okay C efficient + + + align:start position:0% +dens of State this is a Okay C efficient +if your C potential is here + + align:start position:0% +if your C potential is here + + + align:start position:0% +if your C potential is here +this is negative this is positive so + + align:start position:0% +this is negative this is positive so + + + align:start position:0% +this is negative this is positive so +they cancel each other right of course + + align:start position:0% +they cancel each other right of course + + + align:start position:0% +they cancel each other right of course +this is larger so you still have the + + align:start position:0% +this is larger so you still have the + + + align:start position:0% +this is larger so you still have the +cancellation small but if you put a + + align:start position:0% +cancellation small but if you put a + + + align:start position:0% +cancellation small but if you put a +potential so you you have a particle or + + align:start position:0% +potential so you you have a particle or + + + align:start position:0% +potential so you you have a particle or +you have an interface that just happen + + align:start position:0% +you have an interface that just happen + + + align:start position:0% +you have an interface that just happen +to have this potential height then those + + align:start position:0% +to have this potential height then those + + + align:start position:0% +to have this potential height then those +electrons are scatter so that's called + + align:start position:0% +electrons are scatter so that's called + + + align:start position:0% +electrons are scatter so that's called +the energy fi term or emission I'll talk + + align:start position:0% +the energy fi term or emission I'll talk + + + align:start position:0% +the energy fi term or emission I'll talk +about th mission in the last lecture we + + align:start position:0% +about th mission in the last lecture we + + + align:start position:0% +about th mission in the last lecture we +talk about theran engines that's a + + align:start position:0% +talk about theran engines that's a + + + align:start position:0% +talk about theran engines that's a +different way but this is doing in solid + + align:start position:0% +different way but this is doing in solid + + + align:start position:0% +different way but this is doing in solid +so you scatter this low energy electron + + align:start position:0% +so you scatter this low energy electron + + + align:start position:0% +so you scatter this low energy electron +and then you only have high energy + + align:start position:0% +and then you only have high energy + + + align:start position:0% +and then you only have high energy +electron and if I dra the den of State + + align:start position:0% +electron and if I dra the den of State + + + align:start position:0% +electron and if I dra the den of State +picture is although there are electron + + align:start position:0% +picture is although there are electron + + + align:start position:0% +picture is although there are electron +in this region but I scatter them they + + align:start position:0% +in this region but I scatter them they + + + align:start position:0% +in this region but I scatter them they +do not move so now the in terms of this + + align:start position:0% +do not move so now the in terms of this + + + align:start position:0% +do not move so now the in terms of this +St what's really moving is still have + + align:start position:0% +St what's really moving is still have + + + align:start position:0% +St what's really moving is still have +per Char picture so that's my + + align:start position:0% +per Char picture so that's my + + + align:start position:0% +per Char picture so that's my +interpretation to this picture uh this + + align:start position:0% +interpretation to this picture uh this + + + align:start position:0% +interpretation to this picture uh this +this different idea can think about the + + align:start position:0% +this different idea can think about the + + + align:start position:0% +this different idea can think about the +state features for electron but really + + align:start position:0% +state features for electron but really + + + align:start position:0% +state features for electron but really +the one that has went so far in the only + + align:start position:0% +the one that has went so far in the only + + + align:start position:0% +the one that has went so far in the only +successful example I + + align:start position:0% +successful example I + + + align:start position:0% +successful example I +know is this one okay truly uh work in + + align:start position:0% +know is this one okay truly uh work in + + + align:start position:0% +know is this one okay truly uh work in +materials so most other approach that's + + align:start position:0% +materials so most other approach that's + + + align:start position:0% +materials so most other approach that's +successful is in + + align:start position:0% +successful is in + + + align:start position:0% +successful is in +PH so with that I brought you from this + + align:start position:0% +PH so with that I brought you from this + + + align:start position:0% +PH so with that I brought you from this +very simple since I don't know you + + align:start position:0% +very simple since I don't know you + + + align:start position:0% +very simple since I don't know you +figure out okay \ No newline at end of file diff --git a/tnmQ8gytqyc.txt b/tnmQ8gytqyc.txt new file mode 100644 index 0000000000000000000000000000000000000000..393dacc53e7296f974b558c4bc8ffdddd72e1a3a --- /dev/null +++ b/tnmQ8gytqyc.txt @@ -0,0 +1,12380 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license your support + + align:start position:0% +a creative commons license your support + + + align:start position:0% +a creative commons license your support +will help mit opencourseware continue to + + align:start position:0% +will help mit opencourseware continue to + + + align:start position:0% +will help mit opencourseware continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so looking at + + align:start position:0% + + + + align:start position:0% + +things here + + align:start position:0% +things here + + + align:start position:0% +things here +right + + align:start position:0% +right + + + align:start position:0% +right +x and theta and how they can be + + align:start position:0% +x and theta and how they can be + + + align:start position:0% +x and theta and how they can be +represented + + align:start position:0% +represented + + + align:start position:0% +represented +uh but you can create some really + + align:start position:0% +uh but you can create some really + + + align:start position:0% +uh but you can create some really +beautiful images out of that you can + + align:start position:0% +beautiful images out of that you can + + + align:start position:0% +beautiful images out of that you can +even create + + align:start position:0% + + + + align:start position:0% + +you can create some really interesting + + align:start position:0% +you can create some really interesting + + + align:start position:0% +you can create some really interesting +pictures like this + + align:start position:0% +pictures like this + + + align:start position:0% +pictures like this +so if i + + align:start position:0% +so if i + + + align:start position:0% +so if i +uh + + align:start position:0% + + + + align:start position:0% + +this picture + + align:start position:0% +this picture + + + align:start position:0% +this picture +is made + + align:start position:0% +is made + + + align:start position:0% +is made +in that x theta space the coordinates + + align:start position:0% +in that x theta space the coordinates + + + align:start position:0% +in that x theta space the coordinates +are a little bit + + align:start position:0% +are a little bit + + + align:start position:0% +are a little bit +uh changed here this is a this is a + + align:start position:0% +uh changed here this is a this is a + + + align:start position:0% +uh changed here this is a this is a +slide from + + align:start position:0% +slide from + + + align:start position:0% +slide from +uh samus enough + + align:start position:0% +uh samus enough + + + align:start position:0% +uh samus enough +and + + align:start position:0% +and + + + align:start position:0% +and +there's a robot that + + align:start position:0% +there's a robot that + + + align:start position:0% +there's a robot that +andrew adams built at stanford just + + align:start position:0% +andrew adams built at stanford just + + + align:start position:0% +andrew adams built at stanford just +using legos and you can do this for your + + align:start position:0% +using legos and you can do this for your + + + align:start position:0% +using legos and you can do this for your +assignment as well + + align:start position:0% +assignment as well + + + align:start position:0% +assignment as well +you can build a lego based + + align:start position:0% +you can build a lego based + + + align:start position:0% +you can build a lego based +uh + + align:start position:0% +uh + + + align:start position:0% +uh +gang tree + + align:start position:0% +gang tree + + + align:start position:0% +gang tree +that can + + align:start position:0% +that can + + + align:start position:0% +that can +you know shift and take these pictures + + align:start position:0% +you know shift and take these pictures + + + align:start position:0% +you know shift and take these pictures +for your assignment you're just doing + + align:start position:0% +for your assignment you're just doing + + + align:start position:0% +for your assignment you're just doing +one day translation + + align:start position:0% +one day translation + + + align:start position:0% +one day translation +but you could even do 2d translation + + align:start position:0% +but you could even do 2d translation + + + align:start position:0% +but you could even do 2d translation +and then imagine if i put a camera here + + align:start position:0% +and then imagine if i put a camera here + + + align:start position:0% +and then imagine if i put a camera here +and i simply translate it + + align:start position:0% +and i simply translate it + + + align:start position:0% +and i simply translate it +and now we are in flatline when + + align:start position:0% +and now we are in flatline when + + + align:start position:0% +and now we are in flatline when +the camera is here i will take a picture + + align:start position:0% +the camera is here i will take a picture + + + align:start position:0% +the camera is here i will take a picture +and put it over here this launcher + + align:start position:0% +and put it over here this launcher + + + align:start position:0% +and put it over here this launcher +okay then i'll move the camera and i'll + + align:start position:0% +okay then i'll move the camera and i'll + + + align:start position:0% +okay then i'll move the camera and i'll +stack those images + + align:start position:0% +stack those images + + + align:start position:0% +stack those images +so for example when i am + + align:start position:0% + + + + align:start position:0% + +so yeah if you look at this particular + + align:start position:0% +so yeah if you look at this particular + + + align:start position:0% +so yeah if you look at this particular +green object + + align:start position:0% +green object + + + align:start position:0% +green object +over here you'll see that it creates + + align:start position:0% +over here you'll see that it creates + + + align:start position:0% +over here you'll see that it creates +actually a line + + align:start position:0% +actually a line + + + align:start position:0% +actually a line +because when i'm gonna start + + align:start position:0% +because when i'm gonna start + + + align:start position:0% +because when i'm gonna start +transferring it it creates that line on + + align:start position:0% +transferring it it creates that line on + + + align:start position:0% +transferring it it creates that line on +the other hand this particular white + + align:start position:0% +the other hand this particular white + + + align:start position:0% +the other hand this particular white +sphere + + align:start position:0% +sphere + + + align:start position:0% +sphere +ends up mapping with this really strange + + align:start position:0% +ends up mapping with this really strange + + + align:start position:0% +ends up mapping with this really strange +object here + + align:start position:0% +object here + + + align:start position:0% +object here +so this is the visualization of the same + + align:start position:0% +so this is the visualization of the same + + + align:start position:0% +so this is the visualization of the same +space that you saw earlier which looks + + align:start position:0% +space that you saw earlier which looks + + + align:start position:0% +space that you saw earlier which looks +you know maybe simple and very boring + + align:start position:0% +you know maybe simple and very boring + + + align:start position:0% +you know maybe simple and very boring +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so once you start putting interesting + + align:start position:0% +so once you start putting interesting + + + align:start position:0% +so once you start putting interesting +objects + + align:start position:0% +objects + + + align:start position:0% +objects +that's how your like fit starts looking + + align:start position:0% +that's how your like fit starts looking + + + align:start position:0% +that's how your like fit starts looking +and this is basically a light fill here + + align:start position:0% +and this is basically a light fill here + + + align:start position:0% +and this is basically a light fill here +t and theta but it's same as x and theta + + align:start position:0% +t and theta but it's same as x and theta + + + align:start position:0% +t and theta but it's same as x and theta +and + + align:start position:0% +and + + + align:start position:0% +and +the the appearance of this room + + align:start position:0% +the the appearance of this room + + + align:start position:0% +the the appearance of this room +through this window + + align:start position:0% +through this window + + + align:start position:0% +through this window +all you have to do is look at this world + + align:start position:0% +all you have to do is look at this world + + + align:start position:0% +all you have to do is look at this world +through this window you cannot go inside + + align:start position:0% +through this window you cannot go inside + + + align:start position:0% +through this window you cannot go inside +to list it from outside + + align:start position:0% +to list it from outside + + + align:start position:0% +to list it from outside +everything that can be captured about + + align:start position:0% +everything that can be captured about + + + align:start position:0% +everything that can be captured about +the scene through this window is + + align:start position:0% +the scene through this window is + + + align:start position:0% +the scene through this window is +represented + + align:start position:0% +represented + + + align:start position:0% +represented +in this 2d electrode + + align:start position:0% +in this 2d electrode + + + align:start position:0% +in this 2d electrode +so now if i want to create any + + align:start position:0% +so now if i want to create any + + + align:start position:0% +so now if i want to create any +refocusing effects any depth of field + + align:start position:0% +refocusing effects any depth of field + + + align:start position:0% +refocusing effects any depth of field +effects all the information is available + + align:start position:0% +effects all the information is available + + + align:start position:0% +effects all the information is available +here and if i just + + align:start position:0% +here and if i just + + + align:start position:0% +here and if i just +reuse the pixels from here and take + + align:start position:0% +reuse the pixels from here and take + + + align:start position:0% +reuse the pixels from here and take +projections and so on i can create the + + align:start position:0% +projections and so on i can create the + + + align:start position:0% +projections and so on i can create the +things + + align:start position:0% + + + + align:start position:0% + +if you're going to twist your twist your + + align:start position:0% +if you're going to twist your twist your + + + align:start position:0% +if you're going to twist your twist your +mind around it and then it starts making + + align:start position:0% +mind around it and then it starts making + + + align:start position:0% +mind around it and then it starts making +sense + + align:start position:0% + + + + align:start position:0% + +for those of you who have a computer + + align:start position:0% +for those of you who have a computer + + + align:start position:0% +for those of you who have a computer +vision background + + align:start position:0% +vision background + + + align:start position:0% +vision background +this is also known as ap polar plane + + align:start position:0% +this is also known as ap polar plane + + + align:start position:0% +this is also known as ap polar plane +images or epi + + align:start position:0% +images or epi + + + align:start position:0% +images or epi +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's go back to some of this concept + + align:start position:0% +so let's go back to some of this concept + + + align:start position:0% +so let's go back to some of this concept +we were talking about earlier + + align:start position:0% +we were talking about earlier + + + align:start position:0% +we were talking about earlier +where + + align:start position:0% +where + + + align:start position:0% +where +you know you're going to represent + + align:start position:0% +you know you're going to represent + + + align:start position:0% +you know you're going to represent +each + + align:start position:0% +each + + + align:start position:0% +each +part of the lens as a different camera + + align:start position:0% +part of the lens as a different camera + + + align:start position:0% +part of the lens as a different camera +so + + align:start position:0% +so + + + align:start position:0% +so +five subsections five games + + align:start position:0% +five subsections five games + + + align:start position:0% +five subsections five games +except + + align:start position:0% +except + + + align:start position:0% +except +we know that + + align:start position:0% +we know that + + + align:start position:0% +we know that +we found the focus at infinity + + align:start position:0% +we found the focus at infinity + + + align:start position:0% +we found the focus at infinity +i can just take the sum of all these + + align:start position:0% +i can just take the sum of all these + + + align:start position:0% +i can just take the sum of all these +images and i'm done + + align:start position:0% +images and i'm done + + + align:start position:0% +images and i'm done +right or average of these images but for + + align:start position:0% +right or average of these images but for + + + align:start position:0% +right or average of these images but for +focus closer + + align:start position:0% +focus closer + + + align:start position:0% +focus closer +then i cannot just take the average i + + align:start position:0% +then i cannot just take the average i + + + align:start position:0% +then i cannot just take the average i +would shift + + align:start position:0% +would shift + + + align:start position:0% +would shift +and what this prism is doing + + align:start position:0% +and what this prism is doing + + + align:start position:0% +and what this prism is doing +in the real world is doing the shifting + + align:start position:0% +in the real world is doing the shifting + + + align:start position:0% +in the real world is doing the shifting +for you + + align:start position:0% +for you + + + align:start position:0% +for you +okay so let's go back to this example + + align:start position:0% + + + + align:start position:0% + +of this notion of shifting and adding + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +i'm going to compare this with + + align:start position:0% +i'm going to compare this with + + + align:start position:0% +i'm going to compare this with +the + + align:start position:0% +the + + + align:start position:0% +the +five camera situation see if i have a + + align:start position:0% +five camera situation see if i have a + + + align:start position:0% +five camera situation see if i have a +point here + + align:start position:0% +point here + + + align:start position:0% +point here +from the first camera the image goes + + align:start position:0% +from the first camera the image goes + + + align:start position:0% +from the first camera the image goes +here the second one it goes there third + + align:start position:0% +here the second one it goes there third + + + align:start position:0% +here the second one it goes there third +one it goes there both front goes here + + align:start position:0% +one it goes there both front goes here + + + align:start position:0% +one it goes there both front goes here +this one is here + + align:start position:0% + + + + align:start position:0% + +and that's my pinball camera + + align:start position:0% + + + + align:start position:0% + +okay so as you can see if the point is + + align:start position:0% +okay so as you can see if the point is + + + align:start position:0% +okay so as you can see if the point is +close by the coordinates here are not + + align:start position:0% +close by the coordinates here are not + + + align:start position:0% +close by the coordinates here are not +the same + + align:start position:0% +the same + + + align:start position:0% +the same +here it's near the zero and here's a + + align:start position:0% +here it's near the zero and here's a + + + align:start position:0% +here it's near the zero and here's a +little bit further up from the center + + align:start position:0% +little bit further up from the center + + + align:start position:0% +little bit further up from the center +and here is + + align:start position:0% +and here is + + + align:start position:0% +and here is +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +so when i have to bring these five + + align:start position:0% +so when i have to bring these five + + + align:start position:0% +so when i have to bring these five +images i need to shift these images so + + align:start position:0% +images i need to shift these images so + + + align:start position:0% +images i need to shift these images so +that these are all guys overlap on top + + align:start position:0% +that these are all guys overlap on top + + + align:start position:0% +that these are all guys overlap on top +of each other so that this point will be + + align:start position:0% +of each other so that this point will be + + + align:start position:0% +of each other so that this point will be +sharp focus + + align:start position:0% +sharp focus + + + align:start position:0% +sharp focus +the lens does that for you automatically + + align:start position:0% +the lens does that for you automatically + + + align:start position:0% +the lens does that for you automatically +because + + align:start position:0% +because + + + align:start position:0% +because +because of the prism if i put a painting + + align:start position:0% +because of the prism if i put a painting + + + align:start position:0% +because of the prism if i put a painting +here + + align:start position:0% +here + + + align:start position:0% +here +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and there is just a + + align:start position:0% +and there is just a + + + align:start position:0% +and there is just a +pinhole here + + align:start position:0% +pinhole here + + + align:start position:0% +pinhole here +this is abc + + align:start position:0% +this is abc + + + align:start position:0% +this is abc +right this will come back as abc + + align:start position:0% + + + + align:start position:0% + +okay but this one here + + align:start position:0% +okay but this one here + + + align:start position:0% +okay but this one here +would have created an image that + + align:start position:0% + + + + align:start position:0% + +looks like this + + align:start position:0% + + + + align:start position:0% + +but because of the prism + + align:start position:0% +but because of the prism + + + align:start position:0% +but because of the prism +it rotates the image and then this thing + + align:start position:0% +it rotates the image and then this thing + + + align:start position:0% +it rotates the image and then this thing +shifts down + + align:start position:0% +shifts down + + + align:start position:0% +shifts down +so they are on top of each other + + align:start position:0% +so they are on top of each other + + + align:start position:0% +so they are on top of each other +and because of this part of the prism it + + align:start position:0% +and because of this part of the prism it + + + align:start position:0% +and because of this part of the prism it +shifts + + align:start position:0% +shifts + + + align:start position:0% +shifts +it would have the image would have been + + align:start position:0% +it would have the image would have been + + + align:start position:0% +it would have the image would have been +created here the abc + + align:start position:0% +created here the abc + + + align:start position:0% +created here the abc +but shifts just a little bit + + align:start position:0% +but shifts just a little bit + + + align:start position:0% +but shifts just a little bit +and so on and for the other one the + + align:start position:0% +and so on and for the other one the + + + align:start position:0% +and so on and for the other one the +image would have been formed here it + + align:start position:0% +image would have been formed here it + + + align:start position:0% +image would have been formed here it +shifts up so the prism does the job for + + align:start position:0% +shifts up so the prism does the job for + + + align:start position:0% +shifts up so the prism does the job for +you basically of shifting these images + + align:start position:0% +you basically of shifting these images + + + align:start position:0% +you basically of shifting these images +so that's so very simple we are thinking + + align:start position:0% +so that's so very simple we are thinking + + + align:start position:0% +so that's so very simple we are thinking +about + + align:start position:0% +about + + + align:start position:0% +about +how + + align:start position:0% +how + + + align:start position:0% +how +we can emulate a very large lens by an + + align:start position:0% +we can emulate a very large lens by an + + + align:start position:0% +we can emulate a very large lens by an +array of canvas + + align:start position:0% +array of canvas + + + align:start position:0% +array of canvas +so the top cameras here should shift + + align:start position:0% +so the top cameras here should shift + + + align:start position:0% +so the top cameras here should shift +jump shift down into images and the + + align:start position:0% +jump shift down into images and the + + + align:start position:0% +jump shift down into images and the +bottom cameras should shift up and by + + align:start position:0% +bottom cameras should shift up and by + + + align:start position:0% +bottom cameras should shift up and by +doing that you can focus anyway + + align:start position:0% +doing that you can focus anyway + + + align:start position:0% +doing that you can focus anyway +except that in case of a traditional + + align:start position:0% +except that in case of a traditional + + + align:start position:0% +except that in case of a traditional +lens once the photo is taken you are + + align:start position:0% +lens once the photo is taken you are + + + align:start position:0% +lens once the photo is taken you are +done + + align:start position:0% +done + + + align:start position:0% +done +in case of an area of cameras + + align:start position:0% +in case of an area of cameras + + + align:start position:0% +in case of an area of cameras +you can take those pictures and shift as + + align:start position:0% +you can take those pictures and shift as + + + align:start position:0% +you can take those pictures and shift as +much as you want you want and add them + + align:start position:0% +much as you want you want and add them + + + align:start position:0% +much as you want you want and add them +in interesting + + align:start position:0% +in interesting + + + align:start position:0% +in interesting +and that's why like fits are so powerful + + align:start position:0% +and that's why like fits are so powerful + + + align:start position:0% +and that's why like fits are so powerful +so instead of using now an area of + + align:start position:0% +so instead of using now an area of + + + align:start position:0% +so instead of using now an area of +cameras + + align:start position:0% +cameras + + + align:start position:0% +cameras +we're going to build landslide arrays or + + align:start position:0% +we're going to build landslide arrays or + + + align:start position:0% +we're going to build landslide arrays or +some other + + align:start position:0% +some other + + + align:start position:0% +some other +fantasy optics so that i can directly + + align:start position:0% +fantasy optics so that i can directly + + + align:start position:0% +fantasy optics so that i can directly +capture these five images + + align:start position:0% +capture these five images + + + align:start position:0% +capture these five images +in a single function + + align:start position:0% + + + + align:start position:0% + +okay there is three ways + + align:start position:0% +okay there is three ways + + + align:start position:0% +okay there is three ways +of creating + + align:start position:0% +of creating + + + align:start position:0% +of creating +yes + + align:start position:0% + + + + align:start position:0% + +when you think about the stanford camera + + align:start position:0% +when you think about the stanford camera + + + align:start position:0% +when you think about the stanford camera +you want each of these cameras to have + + align:start position:0% +you want each of these cameras to have + + + align:start position:0% +you want each of these cameras to have +independent depth of it so everything is + + align:start position:0% +independent depth of it so everything is + + + align:start position:0% +independent depth of it so everything is +sharp focus which means it's a pinhole + + align:start position:0% +sharp focus which means it's a pinhole + + + align:start position:0% +sharp focus which means it's a pinhole +camera so conceptually yes it's a + + align:start position:0% +camera so conceptually yes it's a + + + align:start position:0% +camera so conceptually yes it's a +pinhole camera but in real world you + + align:start position:0% +pinhole camera but in real world you + + + align:start position:0% +pinhole camera but in real world you +cannot help in the camera + + align:start position:0% +cannot help in the camera + + + align:start position:0% +cannot help in the camera +so + + align:start position:0% +so + + + align:start position:0% +so +they try to keep that aperture small but + + align:start position:0% +they try to keep that aperture small but + + + align:start position:0% +they try to keep that aperture small but +you know if you use a really cheap + + align:start position:0% +you know if you use a really cheap + + + align:start position:0% +you know if you use a really cheap +camera like a cell phone camera + + align:start position:0% +camera like a cell phone camera + + + align:start position:0% +camera like a cell phone camera +they usually have a pretty large depth + + align:start position:0% +they usually have a pretty large depth + + + align:start position:0% +they usually have a pretty large depth +of field on you so they're as close to + + align:start position:0% +of field on you so they're as close to + + + align:start position:0% +of field on you so they're as close to +pinhole as you can get + + align:start position:0% + + + + align:start position:0% + +okay so basically three ways of + + align:start position:0% +okay so basically three ways of + + + align:start position:0% +okay so basically three ways of +capturing + + align:start position:0% +capturing + + + align:start position:0% +capturing +light for you + + align:start position:0% +light for you + + + align:start position:0% +light for you +something that exploits shadows and + + align:start position:0% +something that exploits shadows and + + + align:start position:0% +something that exploits shadows and +pinhole array 1908 + + align:start position:0% +pinhole array 1908 + + + align:start position:0% +pinhole array 1908 +something that uses landslide array also + + align:start position:0% +something that uses landslide array also + + + align:start position:0% +something that uses landslide array also +uh early 1900s + + align:start position:0% +uh early 1900s + + + align:start position:0% +uh early 1900s +and so-called heterodyne + + align:start position:0% +and so-called heterodyne + + + align:start position:0% +and so-called heterodyne +after 100 years in my group + + align:start position:0% +after 100 years in my group + + + align:start position:0% +after 100 years in my group +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so took 100 years to come up with a + + align:start position:0% +so took 100 years to come up with a + + + align:start position:0% +so took 100 years to come up with a +third solution + + align:start position:0% +third solution + + + align:start position:0% +third solution +um + + align:start position:0% +um + + + align:start position:0% +um +think about + + align:start position:0% +think about + + + align:start position:0% +think about +how you can uh you know as i said a sub + + align:start position:0% +how you can uh you know as i said a sub + + + align:start position:0% +how you can uh you know as i said a sub +aperture is basically a pinhole with a + + align:start position:0% +aperture is basically a pinhole with a + + + align:start position:0% +aperture is basically a pinhole with a +prism + + align:start position:0% +prism + + + align:start position:0% +prism +so i can take each of these pinholes + + align:start position:0% +so i can take each of these pinholes + + + align:start position:0% +so i can take each of these pinholes +and just so + + align:start position:0% +and just so + + + align:start position:0% +and just so +you have this you have this and the + + align:start position:0% +you have this you have this and the + + + align:start position:0% +you have this you have this and the +third one would be i can just put a + + align:start position:0% +third one would be i can just put a + + + align:start position:0% +third one would be i can just put a +pinhole + + align:start position:0% +pinhole + + + align:start position:0% +pinhole +and in front of this i can put a prism + + align:start position:0% +and in front of this i can put a prism + + + align:start position:0% +and in front of this i can put a prism +in front of this i'll put a + + align:start position:0% +in front of this i'll put a + + + align:start position:0% +in front of this i'll put a +shower present in front of this piece of + + align:start position:0% +shower present in front of this piece of + + + align:start position:0% +shower present in front of this piece of +glass + + align:start position:0% +glass + + + align:start position:0% +glass +here + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +so lens is basically area of pimples + + align:start position:0% +so lens is basically area of pimples + + + align:start position:0% +so lens is basically area of pimples +with a set of pistons + + align:start position:0% + + + + align:start position:0% + +and as you saw + + align:start position:0% +and as you saw + + + align:start position:0% +and as you saw +if you have two + + align:start position:0% +if you have two + + + align:start position:0% +if you have two +corners of this pinhole the image will + + align:start position:0% +corners of this pinhole the image will + + + align:start position:0% +corners of this pinhole the image will +be formed with large sensor + + align:start position:0% +be formed with large sensor + + + align:start position:0% +be formed with large sensor +but the lens does a smart job of just + + align:start position:0% +but the lens does a smart job of just + + + align:start position:0% +but the lens does a smart job of just +bending like + + align:start position:0% +bending like + + + align:start position:0% +bending like +this + + align:start position:0% + + + + align:start position:0% + +okay so this figure is from uh from from + + align:start position:0% +okay so this figure is from uh from from + + + align:start position:0% +okay so this figure is from uh from from +lipman i believe in 1930 sorry this one + + align:start position:0% +lipman i believe in 1930 sorry this one + + + align:start position:0% +lipman i believe in 1930 sorry this one +is lipman this one is in 1933 and he + + align:start position:0% +is lipman this one is in 1933 and he + + + align:start position:0% +is lipman this one is in 1933 and he +said okay if you really want to capture + + align:start position:0% +said okay if you really want to capture + + + align:start position:0% +said okay if you really want to capture +each of these individually + + align:start position:0% +each of these individually + + + align:start position:0% +each of these individually +you can just put a pin for that + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +if i put a pinhole area there + + align:start position:0% +if i put a pinhole area there + + + align:start position:0% +if i put a pinhole area there +and and and take a picture so no + + align:start position:0% +and and and take a picture so no + + + align:start position:0% +and and and take a picture so no +legislate array just a pin hole + + align:start position:0% +legislate array just a pin hole + + + align:start position:0% +legislate array just a pin hole +then you end up getting a picture that + + align:start position:0% +then you end up getting a picture that + + + align:start position:0% +then you end up getting a picture that +looks like this + + align:start position:0% +looks like this + + + align:start position:0% +looks like this +and if you zoom in on that + + align:start position:0% +and if you zoom in on that + + + align:start position:0% +and if you zoom in on that +you'll see that under each pinhole it + + align:start position:0% +you'll see that under each pinhole it + + + align:start position:0% +you'll see that under each pinhole it +will create a disc + + align:start position:0% +will create a disc + + + align:start position:0% +will create a disc +so remember we had a lens light + + align:start position:0% + + + + align:start position:0% + +yeah so that's that's an example of uh + + align:start position:0% + + + + align:start position:0% + +so this is our solution number one + + align:start position:0% +so this is our solution number one + + + align:start position:0% +so this is our solution number one +is our solution number two and solution + + align:start position:0% +is our solution number two and solution + + + align:start position:0% +is our solution number two and solution +number three + + align:start position:0% +number three + + + align:start position:0% +number three +will + + align:start position:0% + + + + align:start position:0% + +uh and it turns out if you think about a + + align:start position:0% +uh and it turns out if you think about a + + + align:start position:0% +uh and it turns out if you think about a +glare in a scene + + align:start position:0% +glare in a scene + + + align:start position:0% +glare in a scene +like a lens flare + + align:start position:0% +like a lens flare + + + align:start position:0% +like a lens flare +uh a 2d image might look like that on + + align:start position:0% +uh a 2d image might look like that on + + + align:start position:0% +uh a 2d image might look like that on +the top right + + align:start position:0% +the top right + + + align:start position:0% +the top right +but if you zoom in + + align:start position:0% +but if you zoom in + + + align:start position:0% +but if you zoom in +it turns out in the 4d space + + align:start position:0% +it turns out in the 4d space + + + align:start position:0% +it turns out in the 4d space +the glare manifests itself as this + + align:start position:0% +the glare manifests itself as this + + + align:start position:0% +the glare manifests itself as this +bright spots in a corner can match so + + align:start position:0% +bright spots in a corner can match so + + + align:start position:0% +bright spots in a corner can match so +you can just go through this image and + + align:start position:0% +you can just go through this image and + + + align:start position:0% +you can just go through this image and +eliminate all the all the bright spots + + align:start position:0% +eliminate all the all the bright spots + + + align:start position:0% +eliminate all the all the bright spots +and you can get rid of lens flare + + align:start position:0% + + + + align:start position:0% + +and you know so you can remove the + + align:start position:0% +and you know so you can remove the + + + align:start position:0% +and you know so you can remove the +outliers just do some kind of a medium + + align:start position:0% +outliers just do some kind of a medium + + + align:start position:0% +outliers just do some kind of a medium +filtering in a neighborhood + + align:start position:0% +filtering in a neighborhood + + + align:start position:0% +filtering in a neighborhood +and the lens flare is removed + + align:start position:0% + + + + align:start position:0% + +all right so the second way of doing it + + align:start position:0% +all right so the second way of doing it + + + align:start position:0% +all right so the second way of doing it +is by using lenslet array which we + + align:start position:0% +is by using lenslet array which we + + + align:start position:0% +is by using lenslet array which we +already saw so i'm going to repeat that + + align:start position:0% +already saw so i'm going to repeat that + + + align:start position:0% +already saw so i'm going to repeat that +again + + align:start position:0% +again + + + align:start position:0% +again +and now comes the question of + + align:start position:0% +and now comes the question of + + + align:start position:0% +and now comes the question of +what happens to points that are in focus + + align:start position:0% +what happens to points that are in focus + + + align:start position:0% +what happens to points that are in focus +versus order focus okay and this is a + + align:start position:0% +versus order focus okay and this is a + + + align:start position:0% +versus order focus okay and this is a +very key concept uh you have to + + align:start position:0% +very key concept uh you have to + + + align:start position:0% +very key concept uh you have to +understand + + align:start position:0% +understand + + + align:start position:0% +understand +so let's say + + align:start position:0% +so let's say + + + align:start position:0% +so let's say +i have a level + + align:start position:0% + + + + align:start position:0% + +uh and i have a point that's in sharp + + align:start position:0% +uh and i have a point that's in sharp + + + align:start position:0% +uh and i have a point that's in sharp +focus + + align:start position:0% +focus + + + align:start position:0% +focus +at one of these + + align:start position:0% +at one of these + + + align:start position:0% +at one of these +and same situation + + align:start position:0% +and same situation + + + align:start position:0% +and same situation +if the point is in sharp focus + + align:start position:0% +if the point is in sharp focus + + + align:start position:0% +if the point is in sharp focus +at this pin + + align:start position:0% + + + + align:start position:0% + +light will go back + + align:start position:0% +light will go back + + + align:start position:0% +light will go back +and i will create a disk + + align:start position:0% +and i will create a disk + + + align:start position:0% +and i will create a disk +here + + align:start position:0% +here + + + align:start position:0% +here +but let's say this is the this is the + + align:start position:0% +but let's say this is the this is the + + + align:start position:0% +but let's say this is the this is the +red + + align:start position:0% +red + + + align:start position:0% +red +crayon + + align:start position:0% +crayon + + + align:start position:0% +crayon +all the rays are red + + align:start position:0% +all the rays are red + + + align:start position:0% +all the rays are red +and when we come back to the spin hole + + align:start position:0% +and when we come back to the spin hole + + + align:start position:0% +and when we come back to the spin hole +this whole thing looks wet + + align:start position:0% +this whole thing looks wet + + + align:start position:0% +this whole thing looks wet +so that's why + + align:start position:0% +so that's why + + + align:start position:0% +so that's why +in this part of the image + + align:start position:0% +in this part of the image + + + align:start position:0% +in this part of the image +where in the original photo with the + + align:start position:0% +where in the original photo with the + + + align:start position:0% +where in the original photo with the +original camera + + align:start position:0% +original camera + + + align:start position:0% +original camera +the the red crayons are in sharp focus + + align:start position:0% +the the red crayons are in sharp focus + + + align:start position:0% +the the red crayons are in sharp focus +the whole disc is right + + align:start position:0% + + + + align:start position:0% + +which means that + + align:start position:0% +which means that + + + align:start position:0% +which means that +the whole + + align:start position:0% +the whole + + + align:start position:0% +the whole +every part of the lens + + align:start position:0% +every part of the lens + + + align:start position:0% +every part of the lens +is getting + + align:start position:0% +is getting + + + align:start position:0% +is getting +a red ray as in + + align:start position:0% +a red ray as in + + + align:start position:0% +a red ray as in +from this point + + align:start position:0% +from this point + + + align:start position:0% +from this point +but let's go to a part that's actually + + align:start position:0% +but let's go to a part that's actually + + + align:start position:0% +but let's go to a part that's actually +uh outer force okay so i believe this + + align:start position:0% +uh outer force okay so i believe this + + + align:start position:0% +uh outer force okay so i believe this +one is over here so that's on the + + align:start position:0% +one is over here so that's on the + + + align:start position:0% +one is over here so that's on the +boundary between uh maybe a yellow + + align:start position:0% +boundary between uh maybe a yellow + + + align:start position:0% +boundary between uh maybe a yellow +crayon and a blue cream + + align:start position:0% +crayon and a blue cream + + + align:start position:0% +crayon and a blue cream +so even in the original photo it's all + + align:start position:0% +so even in the original photo it's all + + + align:start position:0% +so even in the original photo it's all +for this + + align:start position:0% +for this + + + align:start position:0% +for this +we didn't have a necessary array to the + + align:start position:0% +we didn't have a necessary array to the + + + align:start position:0% +we didn't have a necessary array to the +outputs and here you can see + + align:start position:0% +outputs and here you can see + + + align:start position:0% +outputs and here you can see +part of the each block + + align:start position:0% +part of the each block + + + align:start position:0% +part of the each block +under a landslide is yellow and the + + align:start position:0% +under a landslide is yellow and the + + + align:start position:0% +under a landslide is yellow and the +other part is blue + + align:start position:0% + + + + align:start position:0% + +so we have a situation + + align:start position:0% +so we have a situation + + + align:start position:0% +so we have a situation +where + + align:start position:0% +where + + + align:start position:0% +where +we have a + + align:start position:0% +we have a + + + align:start position:0% +we have a +focus + + align:start position:0% +focus + + + align:start position:0% +focus +we have + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yellow and blue + + align:start position:0% +yellow and blue + + + align:start position:0% +yellow and blue +yellow + + align:start position:0% + + + + align:start position:0% + +okay but they're actually autofocus + + align:start position:0% +okay but they're actually autofocus + + + align:start position:0% +okay but they're actually autofocus +so if i start shooting the rays from + + align:start position:0% +so if i start shooting the rays from + + + align:start position:0% +so if i start shooting the rays from +that + + align:start position:0% + + + + align:start position:0% + +if i just take the one from the yellow + + align:start position:0% +if i just take the one from the yellow + + + align:start position:0% +if i just take the one from the yellow +blue boundary + + align:start position:0% +blue boundary + + + align:start position:0% +blue boundary +for this part + + align:start position:0% +for this part + + + align:start position:0% +for this part +the light is in focus closer + + align:start position:0% + + + + align:start position:0% + +okay it's in focus closer + + align:start position:0% +okay it's in focus closer + + + align:start position:0% +okay it's in focus closer +and the image is actually false + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +for the bottom part + + align:start position:0% +for the bottom part + + + align:start position:0% +for the bottom part +here all these rays are going to be + + align:start position:0% +here all these rays are going to be + + + align:start position:0% +here all these rays are going to be +but this part here + + align:start position:0% +but this part here + + + align:start position:0% +but this part here +is not here + + align:start position:0% +is not here + + + align:start position:0% +is not here +and from the blue part again we + + align:start position:0% +and from the blue part again we + + + align:start position:0% +and from the blue part again we +shoot the rays + + align:start position:0% +shoot the rays + + + align:start position:0% +shoot the rays +and what you will realize + + align:start position:0% + + + + align:start position:0% + +is that + + align:start position:0% +is that + + + align:start position:0% +is that +you look at this pimple you've had + + align:start position:0% +you look at this pimple you've had + + + align:start position:0% +you look at this pimple you've had +yellow corn coming through and a + + align:start position:0% +yellow corn coming through and a + + + align:start position:0% +yellow corn coming through and a +slightly offset blue core coming + + align:start position:0% +slightly offset blue core coming + + + align:start position:0% +slightly offset blue core coming +and because they were not in sharp focus + + align:start position:0% +and because they were not in sharp focus + + + align:start position:0% +and because they were not in sharp focus +they will contribute through one pink + + align:start position:0% +they will contribute through one pink + + + align:start position:0% +they will contribute through one pink +hole so that part of + + align:start position:0% + + + + align:start position:0% + +now let's go in the + + align:start position:0% + + + + align:start position:0% + +this one is the first + + align:start position:0% +this one is the first + + + align:start position:0% +this one is the first +let's go to the one that's further away + + align:start position:0% +let's go to the one that's further away + + + align:start position:0% +let's go to the one that's further away +let's go by the images + + align:start position:0% + + + + align:start position:0% + +all right let's look at this one this + + align:start position:0% +all right let's look at this one this + + + align:start position:0% +all right let's look at this one this +was the current example so if you just + + align:start position:0% +was the current example so if you just + + + align:start position:0% +was the current example so if you just +look at the green and the one that's + + align:start position:0% +look at the green and the one that's + + + align:start position:0% +look at the green and the one that's +kind of blackish next to it + + align:start position:0% +kind of blackish next to it + + + align:start position:0% +kind of blackish next to it +so this one was very easy the the blue + + align:start position:0% +so this one was very easy the the blue + + + align:start position:0% +so this one was very easy the the blue +was to the left of the yellow in the + + align:start position:0% +was to the left of the yellow in the + + + align:start position:0% +was to the left of the yellow in the +original picture and even inside each + + align:start position:0% +original picture and even inside each + + + align:start position:0% +original picture and even inside each +blob the blue is to the left of the + + align:start position:0% +blob the blue is to the left of the + + + align:start position:0% +blob the blue is to the left of the +earth + + align:start position:0% +earth + + + align:start position:0% +earth +but if you see this one the green is to + + align:start position:0% +but if you see this one the green is to + + + align:start position:0% +but if you see this one the green is to +the left of the dark region so it has + + align:start position:0% +the left of the dark region so it has + + + align:start position:0% +the left of the dark region so it has +fluid + + align:start position:0% + + + + align:start position:0% + +so here the left right ordering is + + align:start position:0% +so here the left right ordering is + + + align:start position:0% +so here the left right ordering is +maintained here the left hand already + + align:start position:0% +maintained here the left hand already + + + align:start position:0% +maintained here the left hand already +switched + + align:start position:0% + + + + align:start position:0% + +and can everybody tell me what's going + + align:start position:0% +and can everybody tell me what's going + + + align:start position:0% +and can everybody tell me what's going +on + + align:start position:0% + + + + align:start position:0% + +remains in the same position + + align:start position:0% +remains in the same position + + + align:start position:0% +remains in the same position +when you are behind the focus plane the + + align:start position:0% +when you are behind the focus plane the + + + align:start position:0% +when you are behind the focus plane the +order is switched + + align:start position:0% +order is switched + + + align:start position:0% +order is switched +and that's why you cannot simply take + + align:start position:0% +and that's why you cannot simply take + + + align:start position:0% +and that's why you cannot simply take +this image and reconstruct the original + + align:start position:0% +this image and reconstruct the original + + + align:start position:0% +this image and reconstruct the original +high frequency higher resolution image + + align:start position:0% + + + + align:start position:0% + +processing for this + + align:start position:0% +processing for this + + + align:start position:0% +processing for this +to be able to recover + + align:start position:0% +to be able to recover + + + align:start position:0% +to be able to recover +so it's a lot of fun to look at these + + align:start position:0% +so it's a lot of fun to look at these + + + align:start position:0% +so it's a lot of fun to look at these +images there's all this information + + align:start position:0% +images there's all this information + + + align:start position:0% +images there's all this information +that's encoded the four dimensional + + align:start position:0% +that's encoded the four dimensional + + + align:start position:0% +that's encoded the four dimensional +information + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so here is our solution + + align:start position:0% +so here is our solution + + + align:start position:0% +so here is our solution +instead of placing the left leg array + + align:start position:0% +instead of placing the left leg array + + + align:start position:0% +instead of placing the left leg array +we're going to place a mask not a + + align:start position:0% +we're going to place a mask not a + + + align:start position:0% +we're going to place a mask not a +pinhole array but specially printed mask + + align:start position:0% +pinhole array but specially printed mask + + + align:start position:0% +pinhole array but specially printed mask +you can just take a medium format camera + + align:start position:0% +you can just take a medium format camera + + + align:start position:0% +you can just take a medium format camera +such as a mamiyan uh just remove the + + align:start position:0% +such as a mamiyan uh just remove the + + + align:start position:0% +such as a mamiyan uh just remove the +ir + + align:start position:0% +ir + + + align:start position:0% +ir +protective glass + + align:start position:0% +protective glass + + + align:start position:0% +protective glass +and then simply drop a film + + align:start position:0% +and then simply drop a film + + + align:start position:0% +and then simply drop a film +on top of + + align:start position:0% +on top of + + + align:start position:0% +on top of +uh the medium format camera sensor + + align:start position:0% +uh the medium format camera sensor + + + align:start position:0% +uh the medium format camera sensor +put back the put back the protective + + align:start position:0% +put back the put back the protective + + + align:start position:0% +put back the put back the protective +glass + + align:start position:0% +glass + + + align:start position:0% +glass +and you're ready to go and you have + + align:start position:0% +and you're ready to go and you have + + + align:start position:0% +and you're ready to go and you have +electric camera + + align:start position:0% + + + + align:start position:0% + +so in this case we are not putting a + + align:start position:0% +so in this case we are not putting a + + + align:start position:0% +so in this case we are not putting a +pinhole array + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% +but + + + align:start position:0% +but +so i'm going to go through the slides + + align:start position:0% +so i'm going to go through the slides + + + align:start position:0% +so i'm going to go through the slides +uh very quickly + + align:start position:0% +uh very quickly + + + align:start position:0% +uh very quickly +instead of putting a pinhole array we're + + align:start position:0% +instead of putting a pinhole array we're + + + align:start position:0% +instead of putting a pinhole array we're +going to place a different type of mask + + align:start position:0% +going to place a different type of mask + + + align:start position:0% +going to place a different type of mask +to capture that + + align:start position:0% +to capture that + + + align:start position:0% +to capture that +and + + align:start position:0% +and + + + align:start position:0% +and +a few concepts that we have to look at + + align:start position:0% +a few concepts that we have to look at + + + align:start position:0% +a few concepts that we have to look at +before we get there + + align:start position:0% +before we get there + + + align:start position:0% +before we get there +is that + + align:start position:0% +is that + + + align:start position:0% +is that +there is this concept of conjugate plane + + align:start position:0% +there is this concept of conjugate plane + + + align:start position:0% +there is this concept of conjugate plane +that if a plane is in sharp focus at + + align:start position:0% +that if a plane is in sharp focus at + + + align:start position:0% +that if a plane is in sharp focus at +sensor then this plane and the + + align:start position:0% +sensor then this plane and the + + + align:start position:0% +sensor then this plane and the +corresponding sensor plane are + + align:start position:0% +corresponding sensor plane are + + + align:start position:0% +corresponding sensor plane are +conjugated with each other + + align:start position:0% +conjugated with each other + + + align:start position:0% +conjugated with each other +if i put the object closer + + align:start position:0% +if i put the object closer + + + align:start position:0% +if i put the object closer +then i must move the sensor further back + + align:start position:0% +then i must move the sensor further back + + + align:start position:0% +then i must move the sensor further back +and those two are conjugate with respect + + align:start position:0% +and those two are conjugate with respect + + + align:start position:0% +and those two are conjugate with respect +to each other and that is defined by the + + align:start position:0% +to each other and that is defined by the + + + align:start position:0% +to each other and that is defined by the +length equation + + align:start position:0% +length equation + + + align:start position:0% +length equation +one over f equals one over u plus + + align:start position:0% +one over f equals one over u plus + + + align:start position:0% +one over f equals one over u plus + + align:start position:0% + + + + align:start position:0% + +now the key concept here is that a lens + + align:start position:0% +now the key concept here is that a lens + + + align:start position:0% +now the key concept here is that a lens +copies + + align:start position:0% +copies + + + align:start position:0% +copies +a light fill from the outside world + + align:start position:0% +a light fill from the outside world + + + align:start position:0% +a light fill from the outside world +to the inside + + align:start position:0% +to the inside + + + align:start position:0% +to the inside +what does that mean + + align:start position:0% +what does that mean + + + align:start position:0% +what does that mean +if i have + + align:start position:0% +if i have + + + align:start position:0% +if i have +so originally what we were doing we were + + align:start position:0% +so originally what we were doing we were + + + align:start position:0% +so originally what we were doing we were +assigning some coordinate system + + align:start position:0% +assigning some coordinate system + + + align:start position:0% +assigning some coordinate system +we called it the theta plane and we call + + align:start position:0% +we called it the theta plane and we call + + + align:start position:0% +we called it the theta plane and we call +this one the next + + align:start position:0% + + + + align:start position:0% + +this is our two plane parameters now + + align:start position:0% +this is our two plane parameters now + + + align:start position:0% +this is our two plane parameters now +there's a little bit of fudging going on + + align:start position:0% +there's a little bit of fudging going on + + + align:start position:0% +there's a little bit of fudging going on +here because + + align:start position:0% +here because + + + align:start position:0% +here because +theta here doesn't really correspond to + + align:start position:0% +theta here doesn't really correspond to + + + align:start position:0% +theta here doesn't really correspond to +absolute angle + + align:start position:0% +absolute angle + + + align:start position:0% +absolute angle +but + + align:start position:0% +but + + + align:start position:0% +but +but a coordinate on this axis so theta + + align:start position:0% +but a coordinate on this axis so theta + + + align:start position:0% +but a coordinate on this axis so theta +is zero here + + align:start position:0% +is zero here + + + align:start position:0% +is zero here +and you know let's say it's + + align:start position:0% +and you know let's say it's + + + align:start position:0% +and you know let's say it's +plus 5 here and minus stock + + align:start position:0% + + + + align:start position:0% + +and x is of course goes from 0 to 1000 + + align:start position:0% + + + + align:start position:0% + +and this is our life the relationship + + align:start position:0% +and this is our life the relationship + + + align:start position:0% +and this is our life the relationship +between any point here that you want + + align:start position:0% +between any point here that you want + + + align:start position:0% +between any point here that you want +here defines the 2d + + align:start position:0% +here defines the 2d + + + align:start position:0% +here defines the 2d +now it turns out + + align:start position:0% +now it turns out + + + align:start position:0% +now it turns out +let's say i have two points here + + align:start position:0% +let's say i have two points here + + + align:start position:0% +let's say i have two points here +a and b + + align:start position:0% +a and b + + + align:start position:0% +a and b +and i have two points here + + align:start position:0% +and i have two points here + + + align:start position:0% +and i have two points here +a and b + + align:start position:0% +a and b + + + align:start position:0% +a and b +so + + align:start position:0% + + + + align:start position:0% + +again okay + + align:start position:0% +again okay + + + align:start position:0% +again okay +the image is formed here i can also + + align:start position:0% +the image is formed here i can also + + + align:start position:0% +the image is formed here i can also +assign a new plane here + + align:start position:0% +assign a new plane here + + + align:start position:0% +assign a new plane here +in a quality span for this expression + + align:start position:0% +in a quality span for this expression + + + align:start position:0% +in a quality span for this expression +this light fit which means this x theta + + align:start position:0% +this light fit which means this x theta + + + align:start position:0% +this light fit which means this x theta +relationship is maintained in this theta + + align:start position:0% +relationship is maintained in this theta + + + align:start position:0% +relationship is maintained in this theta +acceleration + + align:start position:0% +acceleration + + + align:start position:0% +acceleration +so if i take a ray here from i'm going + + align:start position:0% +so if i take a ray here from i'm going + + + align:start position:0% +so if i take a ray here from i'm going +to assign this also let's say i put a + + align:start position:0% +to assign this also let's say i put a + + + align:start position:0% +to assign this also let's say i put a +painting here + + align:start position:0% +painting here + + + align:start position:0% +painting here +okay and assign the coordinate of one to + + align:start position:0% +okay and assign the coordinate of one to + + + align:start position:0% +okay and assign the coordinate of one to +thousand + + align:start position:0% +thousand + + + align:start position:0% +thousand +and here is a coordinate of one thousand + + align:start position:0% + + + + align:start position:0% + +it's good to take some real numbers + + align:start position:0% +it's good to take some real numbers + + + align:start position:0% +it's good to take some real numbers +then if i shoot a rate from + + align:start position:0% +then if i shoot a rate from + + + align:start position:0% +then if i shoot a rate from + + align:start position:0% + + + align:start position:0% +to plus 4 + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +i can guarantee if the plane was in + + align:start position:0% +i can guarantee if the plane was in + + + align:start position:0% +i can guarantee if the plane was in +conjugate that the four will map back to + + align:start position:0% +conjugate that the four will map back to + + + align:start position:0% +conjugate that the four will map back to +um + + align:start position:0% + + + + align:start position:0% + +it will map to the pixel that's 200 + + align:start position:0% + + + + align:start position:0% + +and of course if i have 200 naming to + + align:start position:0% +and of course if i have 200 naming to + + + align:start position:0% +and of course if i have 200 naming to +3 here + + align:start position:0% +3 here + + + align:start position:0% +3 here +3 will automatically map it to also + + align:start position:0% +3 will automatically map it to also + + + align:start position:0% +3 will automatically map it to also +and that's only because this painting is + + align:start position:0% +and that's only because this painting is + + + align:start position:0% +and that's only because this painting is +a sharp focus + + align:start position:0% + + + + align:start position:0% + +this notion of conjugation + + align:start position:0% +this notion of conjugation + + + align:start position:0% +this notion of conjugation +uh + + align:start position:0% +uh + + + align:start position:0% +uh +means that the light field of this next + + align:start position:0% +means that the light field of this next + + + align:start position:0% +means that the light field of this next +theta coordinate is mapped to this theta + + align:start position:0% +theta coordinate is mapped to this theta + + + align:start position:0% +theta coordinate is mapped to this theta +s + + align:start position:0% +s + + + align:start position:0% +s +so i can take + + align:start position:0% +so i can take + + + align:start position:0% +so i can take +parameterization i can shoot all the + + align:start position:0% +parameterization i can shoot all the + + + align:start position:0% +parameterization i can shoot all the +rays here + + align:start position:0% +rays here + + + align:start position:0% +rays here +if there's a point here and i should + + align:start position:0% +if there's a point here and i should + + + align:start position:0% +if there's a point here and i should +trace out + + align:start position:0% +trace out + + + align:start position:0% +trace out +the same point will be sharp focus here + + align:start position:0% +the same point will be sharp focus here + + + align:start position:0% +the same point will be sharp focus here +and all the rays will converge + + align:start position:0% +and all the rays will converge + + + align:start position:0% +and all the rays will converge +okay if i have two rays that are + + align:start position:0% +okay if i have two rays that are + + + align:start position:0% +okay if i have two rays that are +starting in the same theta direction + + align:start position:0% +starting in the same theta direction + + + align:start position:0% +starting in the same theta direction +they'll come out here in the same + + align:start position:0% +they'll come out here in the same + + + align:start position:0% +they'll come out here in the same +theta direction + + align:start position:0% +theta direction + + + align:start position:0% +theta direction +okay and so on so basically i'm creating + + align:start position:0% +okay and so on so basically i'm creating + + + align:start position:0% +okay and so on so basically i'm creating +an exact replica of light for here + + align:start position:0% +an exact replica of light for here + + + align:start position:0% +an exact replica of light for here +inside + + align:start position:0% + + + + align:start position:0% + +and this is possible only when the lens + + align:start position:0% +and this is possible only when the lens + + + align:start position:0% +and this is possible only when the lens +is extremely good + + align:start position:0% + + + + align:start position:0% + +so it might do a pretty good job + + align:start position:0% +so it might do a pretty good job + + + align:start position:0% +so it might do a pretty good job +a not so good lens would do a good job + + align:start position:0% +a not so good lens would do a good job + + + align:start position:0% +a not so good lens would do a good job +of popping it in the center but not at + + align:start position:0% +of popping it in the center but not at + + + align:start position:0% +of popping it in the center but not at +the edges or it might be good for one + + align:start position:0% +the edges or it might be good for one + + + align:start position:0% +the edges or it might be good for one +level but not for others + + align:start position:0% +level but not for others + + + align:start position:0% +level but not for others +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +and + + align:start position:0% +and + + + align:start position:0% +and +this notion of copying the light field + + align:start position:0% +this notion of copying the light field + + + align:start position:0% +this notion of copying the light field +makes the lens very unique because + + align:start position:0% +makes the lens very unique because + + + align:start position:0% +makes the lens very unique because +we know that the appearance of the world + + align:start position:0% +we know that the appearance of the world + + + align:start position:0% +we know that the appearance of the world +is 4d + + align:start position:0% +is 4d + + + align:start position:0% +is 4d +it completely describes + + align:start position:0% +it completely describes + + + align:start position:0% +it completely describes +the appearance of the world and what the + + align:start position:0% +the appearance of the world and what the + + + align:start position:0% +the appearance of the world and what the +lens has done is optically it has copied + + align:start position:0% +lens has done is optically it has copied + + + align:start position:0% +lens has done is optically it has copied +the appearance of the word faithfully to + + align:start position:0% +the appearance of the word faithfully to + + + align:start position:0% +the appearance of the word faithfully to +something that's inside + + align:start position:0% +something that's inside + + + align:start position:0% +something that's inside +okay and now we just need a good quality + + align:start position:0% +okay and now we just need a good quality + + + align:start position:0% +okay and now we just need a good quality +sensor + + align:start position:0% +sensor + + + align:start position:0% +sensor +to basically take the hologram of what's + + align:start position:0% +to basically take the hologram of what's + + + align:start position:0% +to basically take the hologram of what's +out there + + align:start position:0% +out there + + + align:start position:0% +out there +i'm using the word hologram to indicate + + align:start position:0% +i'm using the word hologram to indicate + + + align:start position:0% +i'm using the word hologram to indicate +the 4d appearance of the window + + align:start position:0% + + + + align:start position:0% + +so this window + + align:start position:0% + + + + align:start position:0% + +that we have here + + align:start position:0% +that we have here + + + align:start position:0% +that we have here +is exactly copied + + align:start position:0% +is exactly copied + + + align:start position:0% +is exactly copied +over here so anything that's + + align:start position:0% +over here so anything that's + + + align:start position:0% +over here so anything that's +behind this window is faithfully + + align:start position:0% +behind this window is faithfully + + + align:start position:0% +behind this window is faithfully +influenced over here + + align:start position:0% +influenced over here + + + align:start position:0% +influenced over here +unfortunately in a traditional camera + + align:start position:0% +unfortunately in a traditional camera + + + align:start position:0% +unfortunately in a traditional camera +you take that window and you snap it + + align:start position:0% +you take that window and you snap it + + + align:start position:0% +you take that window and you snap it +back to a 2d + + align:start position:0% +back to a 2d + + + align:start position:0% +back to a 2d +so image + + align:start position:0% +so image + + + align:start position:0% +so image +problem is the sensor the optics is + + align:start position:0% +problem is the sensor the optics is + + + align:start position:0% +problem is the sensor the optics is +doing its job + + align:start position:0% +doing its job + + + align:start position:0% +doing its job +of going from 4d to 4d + + align:start position:0% +of going from 4d to 4d + + + align:start position:0% +of going from 4d to 4d +so 4d in + + align:start position:0% +so 4d in + + + align:start position:0% +so 4d in +right fully up + + align:start position:0% + + + + align:start position:0% + +but sensor does a terrible job of + + align:start position:0% +but sensor does a terrible job of + + + align:start position:0% +but sensor does a terrible job of +maintaining that four-legged user + + align:start position:0% +maintaining that four-legged user + + + align:start position:0% +maintaining that four-legged user +but if you have these three solutions + + align:start position:0% +but if you have these three solutions + + + align:start position:0% +but if you have these three solutions +you can recover + + align:start position:0% +you can recover + + + align:start position:0% +you can recover +this code + + align:start position:0% + + + + align:start position:0% + +so let me + + align:start position:0% +so let me + + + align:start position:0% +so let me +just explain this concept one more time + + align:start position:0% +just explain this concept one more time + + + align:start position:0% +just explain this concept one more time +of + + align:start position:0% +of + + + align:start position:0% +of +how the rays when the sharp focus versus + + align:start position:0% +how the rays when the sharp focus versus + + + align:start position:0% +how the rays when the sharp focus versus +auto focus look differently + + align:start position:0% +auto focus look differently + + + align:start position:0% +auto focus look differently +and i promise you that after you + + align:start position:0% +and i promise you that after you + + + align:start position:0% +and i promise you that after you +understand this concept of rays and ray + + align:start position:0% +understand this concept of rays and ray + + + align:start position:0% +understand this concept of rays and ray +space and all that everything else in + + align:start position:0% +space and all that everything else in + + + align:start position:0% +space and all that everything else in +the auto focus and and depth of field + + align:start position:0% +the auto focus and and depth of field + + + align:start position:0% +the auto focus and and depth of field +will become extremely easy to understand + + align:start position:0% +will become extremely easy to understand + + + align:start position:0% +will become extremely easy to understand +okay so just + + align:start position:0% +okay so just + + + align:start position:0% +okay so just +just see how this works out + + align:start position:0% +just see how this works out + + + align:start position:0% +just see how this works out +so + + align:start position:0% +so + + + align:start position:0% +so +now let's say we have a point here + + align:start position:0% +now let's say we have a point here + + + align:start position:0% +now let's say we have a point here +okay we can either represent the like + + align:start position:0% +okay we can either represent the like + + + align:start position:0% +okay we can either represent the like +field here + + align:start position:0% +field here + + + align:start position:0% +field here +or we can represent it here it doesn't + + align:start position:0% +or we can represent it here it doesn't + + + align:start position:0% +or we can represent it here it doesn't +really matter + + align:start position:0% +really matter + + + align:start position:0% +really matter +now here what we have is a point + + align:start position:0% +now here what we have is a point + + + align:start position:0% +now here what we have is a point +that's emitting light in all directions + + align:start position:0% +that's emitting light in all directions + + + align:start position:0% +that's emitting light in all directions +so how does the light look like + + align:start position:0% +so how does the light look like + + + align:start position:0% +so how does the light look like +there's a point x and it's emitting + + align:start position:0% +there's a point x and it's emitting + + + align:start position:0% +there's a point x and it's emitting +light in all three directions + + align:start position:0% +light in all three directions + + + align:start position:0% +light in all three directions +now we know that the lens is going to + + align:start position:0% +now we know that the lens is going to + + + align:start position:0% +now we know that the lens is going to +make an exact replica of that inside so + + align:start position:0% +make an exact replica of that inside so + + + align:start position:0% +make an exact replica of that inside so +when i come here i have a particular x + + align:start position:0% +when i come here i have a particular x + + + align:start position:0% +when i come here i have a particular x +and light is coming from all different + + align:start position:0% +and light is coming from all different + + + align:start position:0% +and light is coming from all different +directions + + align:start position:0% +directions + + + align:start position:0% +directions +so what's coming at the plane is exactly + + align:start position:0% +so what's coming at the plane is exactly + + + align:start position:0% +so what's coming at the plane is exactly +that + + align:start position:0% +that + + + align:start position:0% +that +okay from this how do i for an image + + align:start position:0% + + + + align:start position:0% + +how do i realize that if i integrate + + align:start position:0% +how do i realize that if i integrate + + + align:start position:0% +how do i realize that if i integrate +the radius along each of these rays i + + align:start position:0% +the radius along each of these rays i + + + align:start position:0% +the radius along each of these rays i +will get the intensity + + align:start position:0% + + + + align:start position:0% + +we are going from a 2d world now to a 1d + + align:start position:0% +we are going from a 2d world now to a 1d + + + align:start position:0% +we are going from a 2d world now to a 1d +world + + align:start position:0% +world + + + align:start position:0% +world +in the in the in the general case we go + + align:start position:0% +in the in the in the general case we go + + + align:start position:0% +in the in the in the general case we go +from + + align:start position:0% +from + + + align:start position:0% +from +from a 4d world to a 2d sensor 4d + + align:start position:0% +from a 4d world to a 2d sensor 4d + + + align:start position:0% +from a 4d world to a 2d sensor 4d +representation 2d sensor here we have 2d + + align:start position:0% +representation 2d sensor here we have 2d + + + align:start position:0% +representation 2d sensor here we have 2d +light fill and 1d sensor + + align:start position:0% + + + + align:start position:0% + +how would you do it + + align:start position:0% + + + + align:start position:0% + +sum over theta i'm just going to sum up + + align:start position:0% +sum over theta i'm just going to sum up + + + align:start position:0% +sum over theta i'm just going to sum up +everything that comes out theta that is + + align:start position:0% +everything that comes out theta that is + + + align:start position:0% +everything that comes out theta that is +i'm going to take all these values + + align:start position:0% +i'm going to take all these values + + + align:start position:0% +i'm going to take all these values +and sum them up + + align:start position:0% +and sum them up + + + align:start position:0% +and sum them up +and mathematically that's just taking a + + align:start position:0% +and mathematically that's just taking a + + + align:start position:0% +and mathematically that's just taking a +projection i'm just going to take this + + align:start position:0% +projection i'm just going to take this + + + align:start position:0% +projection i'm just going to take this +2d world and flatten it + + align:start position:0% +2d world and flatten it + + + align:start position:0% +2d world and flatten it +to a 1d word + + align:start position:0% +to a 1d word + + + align:start position:0% +to a 1d word +okay + + align:start position:0% +okay + + + align:start position:0% +okay +or you can call it line integral + + align:start position:0% +or you can call it line integral + + + align:start position:0% +or you can call it line integral +so imagine + + align:start position:0% +so imagine + + + align:start position:0% +so imagine +i had all this + + align:start position:0% +i had all this + + + align:start position:0% +i had all this +all this + + align:start position:0% +all this + + + align:start position:0% +all this +tennis falls here and i struck + + align:start position:0% +tennis falls here and i struck + + + align:start position:0% +tennis falls here and i struck +all of them under the force of gravity + + align:start position:0% +all of them under the force of gravity + + + align:start position:0% +all of them under the force of gravity +the number of balls that will come here + + align:start position:0% +the number of balls that will come here + + + align:start position:0% +the number of balls that will come here +will be the intensity of that pistol and + + align:start position:0% +will be the intensity of that pistol and + + + align:start position:0% +will be the intensity of that pistol and +will black everywhere else + + align:start position:0% +will black everywhere else + + + align:start position:0% +will black everywhere else +very simple very clean + + align:start position:0% +very simple very clean + + + align:start position:0% +very simple very clean +now what happens when something is out + + align:start position:0% +now what happens when something is out + + + align:start position:0% +now what happens when something is out +of focus + + align:start position:0% +of focus + + + align:start position:0% +of focus +okay + + align:start position:0% +okay + + + align:start position:0% +okay +if it's out of focus + + align:start position:0% +if it's out of focus + + + align:start position:0% +if it's out of focus +then + + align:start position:0% +then + + + align:start position:0% +then +the lens is doing a good job of + + align:start position:0% +the lens is doing a good job of + + + align:start position:0% +the lens is doing a good job of +transferring the 40 here 40 here but if + + align:start position:0% +transferring the 40 here 40 here but if + + + align:start position:0% +transferring the 40 here 40 here but if +you did the right job for this plane + + align:start position:0% +you did the right job for this plane + + + align:start position:0% +you did the right job for this plane +not first + + align:start position:0% +not first + + + align:start position:0% +not first +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so how do we represent the new space + + align:start position:0% +so how do we represent the new space + + + align:start position:0% +so how do we represent the new space +of light failure in this in this case + + align:start position:0% +of light failure in this in this case + + + align:start position:0% +of light failure in this in this case +the light feels very simple there's just + + align:start position:0% +the light feels very simple there's just + + + align:start position:0% +the light feels very simple there's just +one pointer + + align:start position:0% +one pointer + + + align:start position:0% +one pointer +it has a bunch of rays and you want to + + align:start position:0% +it has a bunch of rays and you want to + + + align:start position:0% +it has a bunch of rays and you want to +represent that previously the light was + + align:start position:0% +represent that previously the light was + + + align:start position:0% +represent that previously the light was +reaching only one next point now it's + + align:start position:0% +reaching only one next point now it's + + + align:start position:0% +reaching only one next point now it's +reaching an array of + + align:start position:0% +reaching an array of + + + align:start position:0% +reaching an array of +x points and for each of the x points + + align:start position:0% +x points and for each of the x points + + + align:start position:0% +x points and for each of the x points +there's only one direction in which + + align:start position:0% +there's only one direction in which + + + align:start position:0% +there's only one direction in which +lights are acting + + align:start position:0% +lights are acting + + + align:start position:0% +lights are acting +so there's still a line that's the axis + + align:start position:0% +so there's still a line that's the axis + + + align:start position:0% +so there's still a line that's the axis +is missing + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so i have a bunch of different points + + align:start position:0% +so i have a bunch of different points + + + align:start position:0% +so i have a bunch of different points +here + + align:start position:0% +here + + + align:start position:0% +here +and for each of them there's a + + align:start position:0% +and for each of them there's a + + + align:start position:0% +and for each of them there's a +direction along which the light + + align:start position:0% +direction along which the light + + + align:start position:0% +direction along which the light +so this is the notion of shear + + align:start position:0% +so this is the notion of shear + + + align:start position:0% +so this is the notion of shear +we have a straight line with shear + + align:start position:0% +we have a straight line with shear + + + align:start position:0% +we have a straight line with shear +deterioration + + align:start position:0% +deterioration + + + align:start position:0% +deterioration +and now + + align:start position:0% +and now + + + align:start position:0% +and now +how do we compute the light how do we + + align:start position:0% +how do we compute the light how do we + + + align:start position:0% +how do we compute the light how do we +compute the intensity from the set of + + align:start position:0% +compute the intensity from the set of + + + align:start position:0% +compute the intensity from the set of +rays + + align:start position:0% +rays + + + align:start position:0% +rays +again the same operation of imagine we + + align:start position:0% +again the same operation of imagine we + + + align:start position:0% +again the same operation of imagine we +had all this all this tennis balls here + + align:start position:0% +had all this all this tennis balls here + + + align:start position:0% +had all this all this tennis balls here +and we're going to let them drop + + align:start position:0% +and we're going to let them drop + + + align:start position:0% +and we're going to let them drop +if you let them drop we're going to get + + align:start position:0% +if you let them drop we're going to get + + + align:start position:0% +if you let them drop we're going to get +intensity that + + align:start position:0% +intensity that + + + align:start position:0% +intensity that +goes over a set of pixels rather than + + align:start position:0% +goes over a set of pixels rather than + + + align:start position:0% +goes over a set of pixels rather than +just one pixel + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and that's the capture photo you'll see + + align:start position:0% +and that's the capture photo you'll see + + + align:start position:0% +and that's the capture photo you'll see +when something is out of focus you don't + + align:start position:0% +when something is out of focus you don't + + + align:start position:0% +when something is out of focus you don't +see a sharp point + + align:start position:0% +see a sharp point + + + align:start position:0% +see a sharp point +but you see + + align:start position:0% +but you see + + + align:start position:0% +but you see +a blurred + + align:start position:0% +a blurred + + + align:start position:0% +a blurred +set of values + + align:start position:0% +set of values + + + align:start position:0% +set of values +so again we start from here + + align:start position:0% +so again we start from here + + + align:start position:0% +so again we start from here +exact copy + + align:start position:0% +exact copy + + + align:start position:0% +exact copy +for a given x we have all the thetas we + + align:start position:0% +for a given x we have all the thetas we + + + align:start position:0% +for a given x we have all the thetas we +project we get a sharp point + + align:start position:0% +project we get a sharp point + + + align:start position:0% +project we get a sharp point +that's the intensity of the capture flow + + align:start position:0% +that's the intensity of the capture flow + + + align:start position:0% +that's the intensity of the capture flow +if it's out of focus + + align:start position:0% +if it's out of focus + + + align:start position:0% +if it's out of focus +the set of rays can be represented on a + + align:start position:0% +the set of rays can be represented on a + + + align:start position:0% +the set of rays can be represented on a +slanted line now + + align:start position:0% +slanted line now + + + align:start position:0% +slanted line now +when we project that we get + + align:start position:0% +when we project that we get + + + align:start position:0% +when we project that we get +the integral + + align:start position:0% +the integral + + + align:start position:0% +the integral +and + + align:start position:0% +and + + + align:start position:0% +and +that will be + + align:start position:0% + + + + align:start position:0% + +is this gear + + align:start position:0% + + + + align:start position:0% + +so now when you're thinking about + + align:start position:0% +so now when you're thinking about + + + align:start position:0% +so now when you're thinking about +um + + align:start position:0% +um + + + align:start position:0% +um +now when you're thinking about + + align:start position:0% +now when you're thinking about + + + align:start position:0% +now when you're thinking about +doing your assignment + + align:start position:0% +doing your assignment + + + align:start position:0% +doing your assignment +and you have set up photos + + align:start position:0% + + + + align:start position:0% + +and you want to do refocusing + + align:start position:0% +and you want to do refocusing + + + align:start position:0% +and you want to do refocusing +you can think of in multiple ways + + align:start position:0% +you can think of in multiple ways + + + align:start position:0% +you can think of in multiple ways +if i stack all the photos + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so remember + + align:start position:0% +so remember + + + align:start position:0% +so remember +taking a picture with area of cameras + + align:start position:0% +taking a picture with area of cameras + + + align:start position:0% +taking a picture with area of cameras +is the same thing so i'm going to put an + + align:start position:0% +is the same thing so i'm going to put an + + + align:start position:0% +is the same thing so i'm going to put an +array of canvas here + + align:start position:0% + + + + align:start position:0% + +and the coordinate of the camera is + + align:start position:0% +and the coordinate of the camera is + + + align:start position:0% +and the coordinate of the camera is +thinner + + align:start position:0% +thinner + + + align:start position:0% +thinner +and + + align:start position:0% +and + + + align:start position:0% +and +the framework for the camera is nice + + align:start position:0% +the framework for the camera is nice + + + align:start position:0% +the framework for the camera is nice +so i can take a picture of the first + + align:start position:0% +so i can take a picture of the first + + + align:start position:0% +so i can take a picture of the first +camera + + align:start position:0% +camera + + + align:start position:0% +camera +and i'll put that as the top row of this + + align:start position:0% +and i'll put that as the top row of this + + + align:start position:0% +and i'll put that as the top row of this +i'll take a picture with the theta + + align:start position:0% +i'll take a picture with the theta + + + align:start position:0% +i'll take a picture with the theta +equals two and put it over here sorry + + align:start position:0% +equals two and put it over here sorry + + + align:start position:0% +equals two and put it over here sorry +fit equals five over here four three two + + align:start position:0% +fit equals five over here four three two + + + align:start position:0% +fit equals five over here four three two +one zero if i'm nine cameras i'll put + + align:start position:0% +one zero if i'm nine cameras i'll put + + + align:start position:0% +one zero if i'm nine cameras i'll put +them over here + + align:start position:0% +them over here + + + align:start position:0% +them over here +and if i just want to take a picture + + align:start position:0% +and if i just want to take a picture + + + align:start position:0% +and if i just want to take a picture +that's focused at infinity + + align:start position:0% +that's focused at infinity + + + align:start position:0% +that's focused at infinity +i'm going to start all those pictures + + align:start position:0% +i'm going to start all those pictures + + + align:start position:0% +i'm going to start all those pictures +and just take the sum + + align:start position:0% +and just take the sum + + + align:start position:0% +and just take the sum +along vertical direction + + align:start position:0% +along vertical direction + + + align:start position:0% +along vertical direction +and that will focus at + + align:start position:0% +and that will focus at + + + align:start position:0% +and that will focus at +infinity + + align:start position:0% +infinity + + + align:start position:0% +infinity +right if i want to focus closer + + align:start position:0% +right if i want to focus closer + + + align:start position:0% +right if i want to focus closer +then i shouldn't just sum them up + + align:start position:0% +then i shouldn't just sum them up + + + align:start position:0% +then i shouldn't just sum them up +as they are + + align:start position:0% +as they are + + + align:start position:0% +as they are +but i need to slightly + + align:start position:0% +but i need to slightly + + + align:start position:0% +but i need to slightly +shear them + + align:start position:0% +shear them + + + align:start position:0% +shear them +so i'm going to keep the center camera + + align:start position:0% +so i'm going to keep the center camera + + + align:start position:0% +so i'm going to keep the center camera +center camera image as is i'll take the + + align:start position:0% +center camera image as is i'll take the + + + align:start position:0% +center camera image as is i'll take the +theta equals one camera and shift it to + + align:start position:0% +theta equals one camera and shift it to + + + align:start position:0% +theta equals one camera and shift it to +the left + + align:start position:0% +the left + + + align:start position:0% +the left +by one pixel i'll take three times two + + align:start position:0% +by one pixel i'll take three times two + + + align:start position:0% +by one pixel i'll take three times two +i'll shift it by two pixels three pixels + + align:start position:0% +i'll shift it by two pixels three pixels + + + align:start position:0% +i'll shift it by two pixels three pixels +and five x's + + align:start position:0% +and five x's + + + align:start position:0% +and five x's +minus sorry minus one minus two minus + + align:start position:0% +minus sorry minus one minus two minus + + + align:start position:0% +minus sorry minus one minus two minus +three and one over here are shipped out + + align:start position:0% +three and one over here are shipped out + + + align:start position:0% +three and one over here are shipped out +plus one plus two plus three if i sum + + align:start position:0% +plus one plus two plus three if i sum + + + align:start position:0% +plus one plus two plus three if i sum +them up + + align:start position:0% +them up + + + align:start position:0% +them up +i'll be actually focusing + + align:start position:0% +i'll be actually focusing + + + align:start position:0% +i'll be actually focusing +on a different plane + + align:start position:0% +on a different plane + + + align:start position:0% +on a different plane +so this is the main concept behind + + align:start position:0% +so this is the main concept behind + + + align:start position:0% +so this is the main concept behind +refocusing + + align:start position:0% +refocusing + + + align:start position:0% +refocusing +that + + align:start position:0% +that + + + align:start position:0% +that +it's shifting and adding + + align:start position:0% +it's shifting and adding + + + align:start position:0% +it's shifting and adding +and you can think of that within a + + align:start position:0% +and you can think of that within a + + + align:start position:0% +and you can think of that within a +single lens + + align:start position:0% +single lens + + + align:start position:0% +single lens +or you can think of that using area of + + align:start position:0% +or you can think of that using area of + + + align:start position:0% +or you can think of that using area of +canvas + + align:start position:0% + + + + align:start position:0% + +clear so far + + align:start position:0% +clear so far + + + align:start position:0% +clear so far +so next time you're taking a picture + + align:start position:0% +so next time you're taking a picture + + + align:start position:0% +so next time you're taking a picture +you know think about how much work the + + align:start position:0% +you know think about how much work the + + + align:start position:0% +you know think about how much work the +lens is doing + + align:start position:0% +lens is doing + + + align:start position:0% +lens is doing +you know it's copying the light field + + align:start position:0% +you know it's copying the light field + + + align:start position:0% +you know it's copying the light field +right it's crea it's capturing the + + align:start position:0% +right it's crea it's capturing the + + + align:start position:0% +right it's crea it's capturing the +hologram of what's out there + + align:start position:0% +hologram of what's out there + + + align:start position:0% +hologram of what's out there +right this is using the popular + + align:start position:0% +right this is using the popular + + + align:start position:0% +right this is using the popular +terminology + + align:start position:0% +terminology + + + align:start position:0% +terminology +it's capturing the hologram of what + + align:start position:0% +it's capturing the hologram of what + + + align:start position:0% +it's capturing the hologram of what +what's out there it's recreating that + + align:start position:0% +what's out there it's recreating that + + + align:start position:0% +what's out there it's recreating that +hologram + + align:start position:0% +hologram + + + align:start position:0% +hologram +very close to the sensor + + align:start position:0% +very close to the sensor + + + align:start position:0% +very close to the sensor +and all that the sensor is doing is just + + align:start position:0% +and all that the sensor is doing is just + + + align:start position:0% +and all that the sensor is doing is just +recording that + + align:start position:0% +recording that + + + align:start position:0% +recording that +as a 2d image + + align:start position:0% +as a 2d image + + + align:start position:0% +as a 2d image +because the sensor doesn't have an + + align:start position:0% +because the sensor doesn't have an + + + align:start position:0% +because the sensor doesn't have an +ability to record in a traditional sense + + align:start position:0% +ability to record in a traditional sense + + + align:start position:0% +ability to record in a traditional sense +a 4d hologram it can always sense a 2d + + align:start position:0% +a 4d hologram it can always sense a 2d + + + align:start position:0% +a 4d hologram it can always sense a 2d +image + + align:start position:0% +image + + + align:start position:0% +image +and explain all of that at the speed of + + align:start position:0% +and explain all of that at the speed of + + + align:start position:0% +and explain all of that at the speed of +light + + align:start position:0% +light + + + align:start position:0% +light +isn't it great + + align:start position:0% +isn't it great + + + align:start position:0% +isn't it great +and that's why competition photograph is + + align:start position:0% +and that's why competition photograph is + + + align:start position:0% +and that's why competition photograph is +exciting because + + align:start position:0% +exciting because + + + align:start position:0% +exciting because +there's some work you can let the + + align:start position:0% +there's some work you can let the + + + align:start position:0% +there's some work you can let the +computer do + + align:start position:0% +computer do + + + align:start position:0% +computer do +and there's a lot of work you can just + + align:start position:0% +and there's a lot of work you can just + + + align:start position:0% +and there's a lot of work you can just +let the physics do for you but when the + + align:start position:0% +let the physics do for you but when the + + + align:start position:0% +let the physics do for you but when the +physics does it for you it happens at + + align:start position:0% +physics does it for you it happens at + + + align:start position:0% +physics does it for you it happens at +the speed of light with almost no + + align:start position:0% +the speed of light with almost no + + + align:start position:0% +the speed of light with almost no +additional cost + + align:start position:0% +additional cost + + + align:start position:0% +additional cost +so + + align:start position:0% +so + + + align:start position:0% +so +doing this core design + + align:start position:0% +doing this core design + + + align:start position:0% +doing this core design +of the physical + + align:start position:0% +of the physical + + + align:start position:0% +of the physical +uh device and the computational device + + align:start position:0% +uh device and the computational device + + + align:start position:0% +uh device and the computational device +brings in the real power in a + + align:start position:0% +brings in the real power in a + + + align:start position:0% +brings in the real power in a +competition + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so uh let me switch to some other + + align:start position:0% +so uh let me switch to some other + + + align:start position:0% +so uh let me switch to some other +things i wanted to show you + + align:start position:0% +things i wanted to show you + + + align:start position:0% +things i wanted to show you +by the way is this all clear so far this + + align:start position:0% +by the way is this all clear so far this + + + align:start position:0% +by the way is this all clear so far this +part here + + align:start position:0% +part here + + + align:start position:0% +part here +this will be on your exam remember + + align:start position:0% + + + + align:start position:0% + +this is this is the fun part + + align:start position:0% +this is this is the fun part + + + align:start position:0% +this is this is the fun part +all right so now that we understood all + + align:start position:0% +all right so now that we understood all + + + align:start position:0% +all right so now that we understood all +these concepts of + + align:start position:0% +these concepts of + + + align:start position:0% +these concepts of +uh rays and and flow space let's see how + + align:start position:0% +uh rays and and flow space let's see how + + + align:start position:0% +uh rays and and flow space let's see how +it impacts we already saw autofocus + + align:start position:0% +it impacts we already saw autofocus + + + align:start position:0% +it impacts we already saw autofocus +but let's see how it impacts some other + + align:start position:0% +but let's see how it impacts some other + + + align:start position:0% +but let's see how it impacts some other +elements of photography + + align:start position:0% +elements of photography + + + align:start position:0% +elements of photography +so let's say you have a point light + + align:start position:0% +so let's say you have a point light + + + align:start position:0% +so let's say you have a point light +you take the photo in sharp focus + + align:start position:0% +you take the photo in sharp focus + + + align:start position:0% +you take the photo in sharp focus +it looks like a point + + align:start position:0% +it looks like a point + + + align:start position:0% +it looks like a point +if you take that photo out of focus + + align:start position:0% +if you take that photo out of focus + + + align:start position:0% +if you take that photo out of focus +it appears as a disc + + align:start position:0% + + + + align:start position:0% + +and if you look if you saw this + + align:start position:0% +and if you look if you saw this + + + align:start position:0% +and if you look if you saw this +resolution chart + + align:start position:0% +resolution chart + + + align:start position:0% +resolution chart +then it was blurred as well + + align:start position:0% +then it was blurred as well + + + align:start position:0% +then it was blurred as well +right and here's an example + + align:start position:0% +right and here's an example + + + align:start position:0% +right and here's an example +to answer in a question where we started + + align:start position:0% +to answer in a question where we started + + + align:start position:0% +to answer in a question where we started +with a 2d image + + align:start position:0% +with a 2d image + + + align:start position:0% +with a 2d image +and now we have another 2d image + + align:start position:0% +and now we have another 2d image + + + align:start position:0% +and now we have another 2d image +but + + align:start position:0% +but + + + align:start position:0% +but +the blur the image was converged + + align:start position:0% +the blur the image was converged + + + align:start position:0% +the blur the image was converged +effectively by this disk so we took + + align:start position:0% +effectively by this disk so we took + + + align:start position:0% +effectively by this disk so we took +every point + + align:start position:0% +every point + + + align:start position:0% +every point +if it is grounded summed up all those + + align:start position:0% +if it is grounded summed up all those + + + align:start position:0% +if it is grounded summed up all those +values and assign it over there + + align:start position:0% +values and assign it over there + + + align:start position:0% +values and assign it over there +and which was achieved using the same + + align:start position:0% +and which was achieved using the same + + + align:start position:0% +and which was achieved using the same +effect + + align:start position:0% +effect + + + align:start position:0% +effect +as this + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +every every pixel in the world like this + + align:start position:0% +every every pixel in the world like this + + + align:start position:0% +every every pixel in the world like this +one here actually is contributing to a + + align:start position:0% +one here actually is contributing to a + + + align:start position:0% +one here actually is contributing to a +disk + + align:start position:0% +disk + + + align:start position:0% +disk +okay the other way to think about this + + align:start position:0% +okay the other way to think about this + + + align:start position:0% +okay the other way to think about this +if i just take one pixel here + + align:start position:0% +if i just take one pixel here + + + align:start position:0% +if i just take one pixel here +and go up + + align:start position:0% +and go up + + + align:start position:0% +and go up +vertically + + align:start position:0% +vertically + + + align:start position:0% +vertically +it's coming from different points in the + + align:start position:0% +it's coming from different points in the + + + align:start position:0% +it's coming from different points in the +world + + align:start position:0% +world + + + align:start position:0% +world +and that's how we can specify blood + + align:start position:0% +and that's how we can specify blood + + + align:start position:0% +and that's how we can specify blood +so now we have that + + align:start position:0% + + + + align:start position:0% + +i'll come back to this later + + align:start position:0% +i'll come back to this later + + + align:start position:0% +i'll come back to this later +but every once in a while we can create + + align:start position:0% +but every once in a while we can create + + + align:start position:0% +but every once in a while we can create +some really interesting and this is + + align:start position:0% +some really interesting and this is + + + align:start position:0% +some really interesting and this is +called okay + + align:start position:0% +called okay + + + align:start position:0% +called okay +in in japanese + + align:start position:0% +in in japanese + + + align:start position:0% +in in japanese +what's the right way to say it + + align:start position:0% + + + + align:start position:0% + +yeah okay + + align:start position:0% +yeah okay + + + align:start position:0% +yeah okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and you know the exploitation of out + + align:start position:0% +and you know the exploitation of out + + + align:start position:0% +and you know the exploitation of out +out-of-focus blur + + align:start position:0% +out-of-focus blur + + + align:start position:0% +out-of-focus blur +but sometimes you can do some + + align:start position:0% +but sometimes you can do some + + + align:start position:0% +but sometimes you can do some +interesting things + + align:start position:0% +interesting things + + + align:start position:0% +interesting things +instead of keeping the aperture + + align:start position:0% +instead of keeping the aperture + + + align:start position:0% +instead of keeping the aperture +completely open + + align:start position:0% +completely open + + + align:start position:0% +completely open +you can insert + + align:start position:0% +you can insert + + + align:start position:0% +you can insert +a special pattern + + align:start position:0% +a special pattern + + + align:start position:0% +a special pattern +okay so we're going to place this + + align:start position:0% +okay so we're going to place this + + + align:start position:0% +okay so we're going to place this +crossword puzzle shape mask + + align:start position:0% +crossword puzzle shape mask + + + align:start position:0% +crossword puzzle shape mask +in the aperture + + align:start position:0% +in the aperture + + + align:start position:0% +in the aperture +and now if i take the photo out of focus + + align:start position:0% +and now if i take the photo out of focus + + + align:start position:0% +and now if i take the photo out of focus +instead of getting a disc + + align:start position:0% +instead of getting a disc + + + align:start position:0% +instead of getting a disc +the led that you saw earlier + + align:start position:0% +the led that you saw earlier + + + align:start position:0% +the led that you saw earlier +out of focus will appear something like + + align:start position:0% +out of focus will appear something like + + + align:start position:0% +out of focus will appear something like +this + + align:start position:0% +this + + + align:start position:0% +this +the same + + align:start position:0% +the same + + + align:start position:0% +the same +7x7 pattern that you have here + + align:start position:0% +7x7 pattern that you have here + + + align:start position:0% +7x7 pattern that you have here +in the factory doorway + + align:start position:0% + + + + align:start position:0% + +you see these two lines + + align:start position:0% +you see these two lines + + + align:start position:0% +you see these two lines +and this whole pattern is exactly + + align:start position:0% +and this whole pattern is exactly + + + align:start position:0% +and this whole pattern is exactly +different + + align:start position:0% + + + + align:start position:0% + +okay so you can do some really + + align:start position:0% +okay so you can do some really + + + align:start position:0% +okay so you can do some really +interesting things with it + + align:start position:0% +interesting things with it + + + align:start position:0% +interesting things with it +uh so again + + align:start position:0% +uh so again + + + align:start position:0% +uh so again +photographers you know want to take + + align:start position:0% +photographers you know want to take + + + align:start position:0% +photographers you know want to take +pictures that have really beautiful okay + + align:start position:0% +pictures that have really beautiful okay + + + align:start position:0% +pictures that have really beautiful okay +so when it's really tiny aperture + + align:start position:0% +so when it's really tiny aperture + + + align:start position:0% +so when it's really tiny aperture +things are + + align:start position:0% +things are + + + align:start position:0% +things are +focused over large depth of field + + align:start position:0% +focused over large depth of field + + + align:start position:0% +focused over large depth of field +but with a very large aperture the + + align:start position:0% +but with a very large aperture the + + + align:start position:0% +but with a very large aperture the +background is completely out of works + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +good + + align:start position:0% +good + + + align:start position:0% +good +so + + align:start position:0% +so + + + align:start position:0% +so +now you can start playing some really + + align:start position:0% +now you can start playing some really + + + align:start position:0% +now you can start playing some really +interesting tricks + + align:start position:0% +interesting tricks + + + align:start position:0% +interesting tricks +you can take a seam + + align:start position:0% +you can take a seam + + + align:start position:0% +you can take a seam +which has this chinese price points on a + + align:start position:0% +which has this chinese price points on a + + + align:start position:0% +which has this chinese price points on a +specular fashion + + align:start position:0% + + + + align:start position:0% + +and in your aperture you can instead of + + align:start position:0% +and in your aperture you can instead of + + + align:start position:0% +and in your aperture you can instead of +putting the seven by seven + + align:start position:0% +putting the seven by seven + + + align:start position:0% +putting the seven by seven +uh crossword puzzle shape mask you can + + align:start position:0% +uh crossword puzzle shape mask you can + + + align:start position:0% +uh crossword puzzle shape mask you can +start putting some alphanumeric + + align:start position:0% + + + + align:start position:0% + +characters okay so i'm going to take + + align:start position:0% +characters okay so i'm going to take + + + align:start position:0% +characters okay so i'm going to take +seven different pictures + + align:start position:0% +seven different pictures + + + align:start position:0% +seven different pictures +one with this aperture + + align:start position:0% +one with this aperture + + + align:start position:0% +one with this aperture +one with this aperture one with this + + align:start position:0% +one with this aperture one with this + + + align:start position:0% +one with this aperture one with this +aperture + + align:start position:0% +aperture + + + align:start position:0% +aperture +and if you just take addition of those + + align:start position:0% +and if you just take addition of those + + + align:start position:0% +and if you just take addition of those +three photos so when you take a picture + + align:start position:0% +three photos so when you take a picture + + + align:start position:0% +three photos so when you take a picture +with this aperture you get a vertical + + align:start position:0% +with this aperture you get a vertical + + + align:start position:0% +with this aperture you get a vertical +line + + align:start position:0% +line + + + align:start position:0% +line +for every bright spot out of focus so + + align:start position:0% +for every bright spot out of focus so + + + align:start position:0% +for every bright spot out of focus so +this one you get sort of two line + + align:start position:0% +this one you get sort of two line + + + align:start position:0% +this one you get sort of two line +vertical line vertical line at a + + align:start position:0% +vertical line vertical line at a + + + align:start position:0% +vertical line vertical line at a +different position you just sum them up + + align:start position:0% +different position you just sum them up + + + align:start position:0% +different position you just sum them up +every auto focus part + + align:start position:0% +every auto focus part + + + align:start position:0% +every auto focus part +will + + align:start position:0% +will + + + align:start position:0% +will +have a better cell + + align:start position:0% + + + + align:start position:0% + +so you can + + align:start position:0% +so you can + + + align:start position:0% +so you can +i believe there's an animation here + + align:start position:0% + + + + align:start position:0% + +so you can see letter eight + + align:start position:0% +so you can see letter eight + + + align:start position:0% +so you can see letter eight +appearing at all different places + + align:start position:0% +appearing at all different places + + + align:start position:0% +appearing at all different places +so let's try to understand what's going + + align:start position:0% +so let's try to understand what's going + + + align:start position:0% +so let's try to understand what's going +on here + + align:start position:0% + + + + align:start position:0% + +so that's with a disc aperture like a + + align:start position:0% +so that's with a disc aperture like a + + + align:start position:0% +so that's with a disc aperture like a +traditional aperture + + align:start position:0% +traditional aperture + + + align:start position:0% +traditional aperture +this is the one with + + align:start position:0% +this is the one with + + + align:start position:0% +this is the one with +some special + + align:start position:0% +some special + + + align:start position:0% +some special +okay and if you want you can even say + + align:start position:0% +okay and if you want you can even say + + + align:start position:0% +okay and if you want you can even say +happy birthday jennifer and we'll just + + align:start position:0% +happy birthday jennifer and we'll just + + + align:start position:0% +happy birthday jennifer and we'll just +show up there so if you take a picture + + align:start position:0% +show up there so if you take a picture + + + align:start position:0% +show up there so if you take a picture +of all the candles every candle will say + + align:start position:0% +of all the candles every candle will say + + + align:start position:0% +of all the candles every candle will say +happy birthday + + align:start position:0% + + + + align:start position:0% + +okay so how's this taking place + + align:start position:0% +okay so how's this taking place + + + align:start position:0% +okay so how's this taking place +it's difficult to explain purely as + + align:start position:0% +it's difficult to explain purely as + + + align:start position:0% +it's difficult to explain purely as +as + + align:start position:0% +as + + + align:start position:0% +as +autofocus blur but if you think about + + align:start position:0% +autofocus blur but if you think about + + + align:start position:0% +autofocus blur but if you think about +what's going on over here it's right + + align:start position:0% +what's going on over here it's right + + + align:start position:0% +what's going on over here it's right +here + + align:start position:0% + + + + align:start position:0% + +so we have our lens + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +we have a sensor + + align:start position:0% +we have a sensor + + + align:start position:0% +we have a sensor +we have one candle or one bright spot + + align:start position:0% +we have one candle or one bright spot + + + align:start position:0% +we have one candle or one bright spot +if it's out of focus + + align:start position:0% +if it's out of focus + + + align:start position:0% +if it's out of focus +it will create a disk + + align:start position:0% +it will create a disk + + + align:start position:0% +it will create a disk +here + + align:start position:0% +here + + + align:start position:0% +here +right but imagine you started putting + + align:start position:0% +right but imagine you started putting + + + align:start position:0% +right but imagine you started putting +some interesting character for + + align:start position:0% +some interesting character for + + + align:start position:0% +some interesting character for +simplicity i'm just going to make + + align:start position:0% +simplicity i'm just going to make + + + align:start position:0% +simplicity i'm just going to make +a 1 0 1 0 + + align:start position:0% +a 1 0 1 0 + + + align:start position:0% +a 1 0 1 0 +so i'm going to put + + align:start position:0% +so i'm going to put + + + align:start position:0% +so i'm going to put +a film here + + align:start position:0% +a film here + + + align:start position:0% +a film here +that's + + align:start position:0% +that's + + + align:start position:0% +that's +open + + align:start position:0% +open + + + align:start position:0% +open +closed + + align:start position:0% +closed + + + align:start position:0% +closed +open closed + + align:start position:0% +open closed + + + align:start position:0% +open closed +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +in this part of the lens i will go + + align:start position:0% +in this part of the lens i will go + + + align:start position:0% +in this part of the lens i will go +through + + align:start position:0% +through + + + align:start position:0% +through +so i'll get some value here this part of + + align:start position:0% +so i'll get some value here this part of + + + align:start position:0% +so i'll get some value here this part of +the lens is like blocked because + + align:start position:0% + + + + align:start position:0% + +over here that goes through + + align:start position:0% +over here that goes through + + + align:start position:0% +over here that goes through +circuit + + align:start position:0% +circuit + + + align:start position:0% +circuit +here and this for the lens is part + + align:start position:0% +here and this for the lens is part + + + align:start position:0% +here and this for the lens is part +the pattern that we had here + + align:start position:0% + + + + align:start position:0% + +that will be blur + + align:start position:0% + + + + align:start position:0% + +and if i put a different pattern here + + align:start position:0% +and if i put a different pattern here + + + align:start position:0% +and if i put a different pattern here +i will get a different + + align:start position:0% +i will get a different + + + align:start position:0% +i will get a different +and that's how you can code for the code + + align:start position:0% +and that's how you can code for the code + + + align:start position:0% +and that's how you can code for the code +in the country + + align:start position:0% + + + + align:start position:0% + +how would you think about this + + align:start position:0% +how would you think about this + + + align:start position:0% +how would you think about this +in the expeditions + + align:start position:0% +in the expeditions + + + align:start position:0% +in the expeditions +but remember the world is not as simple + + align:start position:0% +but remember the world is not as simple + + + align:start position:0% +but remember the world is not as simple +there is not this point but there are a + + align:start position:0% +there is not this point but there are a + + + align:start position:0% +there is not this point but there are a +whole bunch of things going on here and + + align:start position:0% +whole bunch of things going on here and + + + align:start position:0% +whole bunch of things going on here and +all of them are interactions + + align:start position:0% +all of them are interactions + + + align:start position:0% +all of them are interactions +if you go to the exterior space what we + + align:start position:0% +if you go to the exterior space what we + + + align:start position:0% +if you go to the exterior space what we +have + + align:start position:0% +have + + + align:start position:0% +have +is + + align:start position:0% +is + + + align:start position:0% +is +you have the x space here he does this + + align:start position:0% +you have the x space here he does this + + + align:start position:0% +you have the x space here he does this +here + + align:start position:0% +here + + + align:start position:0% +here +and by blocking + + align:start position:0% +and by blocking + + + align:start position:0% +and by blocking +uh this part and this part what i'm + + align:start position:0% +uh this part and this part what i'm + + + align:start position:0% +uh this part and this part what i'm +saying is that the top is fine i have + + align:start position:0% +saying is that the top is fine i have + + + align:start position:0% +saying is that the top is fine i have +blocked this part + + align:start position:0% +blocked this part + + + align:start position:0% +blocked this part +here + + align:start position:0% +here + + + align:start position:0% +here +this is delicate basically + + align:start position:0% +this is delicate basically + + + align:start position:0% +this is delicate basically +and this part is open that's fine and + + align:start position:0% +and this part is open that's fine and + + + align:start position:0% +and this part is open that's fine and +then again the bottom part is deleted + + align:start position:0% + + + + align:start position:0% + +so what the optical system is doing here + + align:start position:0% +so what the optical system is doing here + + + align:start position:0% +so what the optical system is doing here +is taking the right fit from outside and + + align:start position:0% +is taking the right fit from outside and + + + align:start position:0% +is taking the right fit from outside and +it's just deleting all the ways here + + align:start position:0% +it's just deleting all the ways here + + + align:start position:0% +it's just deleting all the ways here +it's just blocking all the links + + align:start position:0% +it's just blocking all the links + + + align:start position:0% +it's just blocking all the links +and then we take a picture + + align:start position:0% +and then we take a picture + + + align:start position:0% +and then we take a picture +in great and effective + + align:start position:0% + + + + align:start position:0% + +that's the basic + + align:start position:0% + + + + align:start position:0% + +and then again you can you can play this + + align:start position:0% +and then again you can you can play this + + + align:start position:0% +and then again you can you can play this +cheesy trick of taking multiple images + + align:start position:0% +cheesy trick of taking multiple images + + + align:start position:0% +cheesy trick of taking multiple images +with different blur + + align:start position:0% +with different blur + + + align:start position:0% +with different blur +and because of linearity which we + + align:start position:0% +and because of linearity which we + + + align:start position:0% +and because of linearity which we +discussed last time of light + + align:start position:0% +discussed last time of light + + + align:start position:0% +discussed last time of light +you can + + align:start position:0% +you can + + + align:start position:0% +you can +you can + + align:start position:0% +you can + + + align:start position:0% +you can +you can just take the addition of two + + align:start position:0% +you can just take the addition of two + + + align:start position:0% +you can just take the addition of two +images + + align:start position:0% +images + + + align:start position:0% +images +to create an illusion that the aperture + + align:start position:0% +to create an illusion that the aperture + + + align:start position:0% +to create an illusion that the aperture +actually had + + align:start position:0% +actually had + + + align:start position:0% +actually had +those three apertures + + align:start position:0% +those three apertures + + + align:start position:0% +those three apertures +so instead of putting a seven + + align:start position:0% +so instead of putting a seven + + + align:start position:0% +so instead of putting a seven +in the in the aperture and taking one + + align:start position:0% +in the in the aperture and taking one + + + align:start position:0% +in the in the aperture and taking one +picture you can take three pictures with + + align:start position:0% +picture you can take three pictures with + + + align:start position:0% +picture you can take three pictures with +each of those different apertures and + + align:start position:0% +each of those different apertures and + + + align:start position:0% +each of those different apertures and +just take some of that + + align:start position:0% +just take some of that + + + align:start position:0% +just take some of that +and that's the beauty of light and + + align:start position:0% +and that's the beauty of light and + + + align:start position:0% +and that's the beauty of light and +interaction of light at normal + + align:start position:0% +interaction of light at normal + + + align:start position:0% +interaction of light at normal +intensities you can + + align:start position:0% +intensities you can + + + align:start position:0% +intensities you can +first take a picture and then take an + + align:start position:0% +first take a picture and then take an + + + align:start position:0% +first take a picture and then take an +addition + + align:start position:0% +addition + + + align:start position:0% +addition +as opposed to adding it + + align:start position:0% +as opposed to adding it + + + align:start position:0% +as opposed to adding it +in + + align:start position:0% +in + + + align:start position:0% +in +in the physical domain and then + + align:start position:0% + + + + align:start position:0% + +this is good + + align:start position:0% +this is good + + + align:start position:0% +this is good +so it's a fun project somebody wants to + + align:start position:0% +so it's a fun project somebody wants to + + + align:start position:0% +so it's a fun project somebody wants to +try it out you know + + align:start position:0% +try it out you know + + + align:start position:0% +try it out you know +create nice bouquet + + align:start position:0% +create nice bouquet + + + align:start position:0% +create nice bouquet +beautiful patterns you can also put an + + align:start position:0% +beautiful patterns you can also put an + + + align:start position:0% +beautiful patterns you can also put an +lcd + + align:start position:0% +lcd + + + align:start position:0% +lcd +in the aperture so it's not just a film + + align:start position:0% +in the aperture so it's not just a film + + + align:start position:0% +in the aperture so it's not just a film +and you can change the lcd + + align:start position:0% +and you can change the lcd + + + align:start position:0% +and you can change the lcd +so that depending on the depending on + + align:start position:0% +so that depending on the depending on + + + align:start position:0% +so that depending on the depending on +the + + align:start position:0% +the + + + align:start position:0% +the +event you can change the different + + align:start position:0% +event you can change the different + + + align:start position:0% +event you can change the different +pattern + + align:start position:0% +pattern + + + align:start position:0% +pattern +and you know you'll get very interesting + + align:start position:0% +and you know you'll get very interesting + + + align:start position:0% +and you know you'll get very interesting +effects for the folks + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what's going on with animal eyes and + + align:start position:0% +so what's going on with animal eyes and + + + align:start position:0% +so what's going on with animal eyes and +we'll have a full lecture + + align:start position:0% +we'll have a full lecture + + + align:start position:0% +we'll have a full lecture +a little bit later on animal eyes + + align:start position:0% +a little bit later on animal eyes + + + align:start position:0% +a little bit later on animal eyes +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +you know + + align:start position:0% +you know + + + align:start position:0% +you know +compound eyes of animals are also very + + align:start position:0% +compound eyes of animals are also very + + + align:start position:0% +compound eyes of animals are also very +interesting these are basically area of + + align:start position:0% +interesting these are basically area of + + + align:start position:0% +interesting these are basically area of +lenses + + align:start position:0% +lenses + + + align:start position:0% +lenses +okay but + + align:start position:0% +okay but + + + align:start position:0% +okay but +there's hundreds of hundreds of them + + align:start position:0% +there's hundreds of hundreds of them + + + align:start position:0% +there's hundreds of hundreds of them +um and this is kind of an artistic + + align:start position:0% +um and this is kind of an artistic + + + align:start position:0% +um and this is kind of an artistic +rendering of what + + align:start position:0% +rendering of what + + + align:start position:0% +rendering of what +the creature must be seeing you know + + align:start position:0% +the creature must be seeing you know + + + align:start position:0% +the creature must be seeing you know +just an area of very tiny images + + align:start position:0% +just an area of very tiny images + + + align:start position:0% +just an area of very tiny images +which is not true as we will see later + + align:start position:0% +which is not true as we will see later + + + align:start position:0% +which is not true as we will see later +but that's how the rendition looks like + + align:start position:0% +but that's how the rendition looks like + + + align:start position:0% +but that's how the rendition looks like +so there are projects such as uh tombow + + align:start position:0% +so there are projects such as uh tombow + + + align:start position:0% +so there are projects such as uh tombow +which tries to mimic this concept + + align:start position:0% +which tries to mimic this concept + + + align:start position:0% +which tries to mimic this concept +uh + + align:start position:0% +uh + + + align:start position:0% +uh +to basically reduce the thickness of + + align:start position:0% +to basically reduce the thickness of + + + align:start position:0% +to basically reduce the thickness of +your camera + + align:start position:0% +your camera + + + align:start position:0% +your camera +okay so if you have a + + align:start position:0% +okay so if you have a + + + align:start position:0% +okay so if you have a +35 millimeter lens it will be about 35 + + align:start position:0% +35 millimeter lens it will be about 35 + + + align:start position:0% +35 millimeter lens it will be about 35 +millimeters deep + + align:start position:0% +millimeters deep + + + align:start position:0% +millimeters deep +but imagine if you want to create a + + align:start position:0% +but imagine if you want to create a + + + align:start position:0% +but imagine if you want to create a +camera that's really really thin + + align:start position:0% +camera that's really really thin + + + align:start position:0% +camera that's really really thin +one way of thinking about that is i can + + align:start position:0% +one way of thinking about that is i can + + + align:start position:0% +one way of thinking about that is i can +just split + + align:start position:0% +just split + + + align:start position:0% +just split +my lens into a set of tiny links + + align:start position:0% +my lens into a set of tiny links + + + align:start position:0% +my lens into a set of tiny links +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you go back to this diagram over + + align:start position:0% +so if you go back to this diagram over + + + align:start position:0% +so if you go back to this diagram over +here + + align:start position:0% +here + + + align:start position:0% +here +i have a sensor + + align:start position:0% +i have a sensor + + + align:start position:0% +i have a sensor +and lens light and maintenance i'll just + + align:start position:0% +and lens light and maintenance i'll just + + + align:start position:0% +and lens light and maintenance i'll just +get rid of this + + align:start position:0% +get rid of this + + + align:start position:0% +get rid of this +all i have + + align:start position:0% + + + + align:start position:0% + +and the question is can you do something + + align:start position:0% +and the question is can you do something + + + align:start position:0% +and the question is can you do something +useful for that + + align:start position:0% +useful for that + + + align:start position:0% +useful for that +any guesses what you can do what you + + align:start position:0% +any guesses what you can do what you + + + align:start position:0% +any guesses what you can do what you +cannot do + + align:start position:0% + + + + align:start position:0% + +that's the situation + + align:start position:0% +that's the situation + + + align:start position:0% +that's the situation +so there's no mainlands + + align:start position:0% +so there's no mainlands + + + align:start position:0% +so there's no mainlands +out here + + align:start position:0% +out here + + + align:start position:0% +out here +every point in the world + + align:start position:0% +every point in the world + + + align:start position:0% +every point in the world +maps to + + align:start position:0% +maps to + + + align:start position:0% +maps to +every + + align:start position:0% +every + + + align:start position:0% +every +uh every block + + align:start position:0% + + + + align:start position:0% + +just got rid of + + align:start position:0% +just got rid of + + + align:start position:0% +just got rid of +the transformation + + align:start position:0% +the transformation + + + align:start position:0% +the transformation +so if you have + + align:start position:0% +so if you have + + + align:start position:0% +so if you have +50 such lenses every point will be seen + + align:start position:0% +50 such lenses every point will be seen + + + align:start position:0% +50 such lenses every point will be seen +fifty times + + align:start position:0% +fifty times + + + align:start position:0% +fifty times +okay but each of the image is actually + + align:start position:0% +okay but each of the image is actually + + + align:start position:0% +okay but each of the image is actually +pretty long + + align:start position:0% +pretty long + + + align:start position:0% +pretty long +isn't this basically the same as uh the + + align:start position:0% +isn't this basically the same as uh the + + + align:start position:0% +isn't this basically the same as uh the +light peeled degree a little bit isn't + + align:start position:0% +light peeled degree a little bit isn't + + + align:start position:0% +light peeled degree a little bit isn't +this basically the same + + align:start position:0% +this basically the same + + + align:start position:0% +this basically the same +surface with smaller big rig + + align:start position:0% +surface with smaller big rig + + + align:start position:0% +surface with smaller big rig +the + + align:start position:0% +the + + + align:start position:0% +the +camera already yes yes okay so that's a + + align:start position:0% +camera already yes yes okay so that's a + + + align:start position:0% +camera already yes yes okay so that's a +good point right so + + align:start position:0% +good point right so + + + align:start position:0% +good point right so +let's say i tell you that you have a 16 + + align:start position:0% +let's say i tell you that you have a 16 + + + align:start position:0% +let's say i tell you that you have a 16 +megapixel sensor + + align:start position:0% +megapixel sensor + + + align:start position:0% +megapixel sensor +okay a 16 megapixel in flatland you know + + align:start position:0% +okay a 16 megapixel in flatland you know + + + align:start position:0% +okay a 16 megapixel in flatland you know + + align:start position:0% + + + align:start position:0% +pixels + + align:start position:0% +pixels + + + align:start position:0% +pixels +and + + align:start position:0% +and + + + align:start position:0% +and +you can use the 4000 pixels anywhere you + + align:start position:0% +you can use the 4000 pixels anywhere you + + + align:start position:0% +you can use the 4000 pixels anywhere you +want + + align:start position:0% +want + + + align:start position:0% +want +okay and you have some resolution in + + align:start position:0% +okay and you have some resolution in + + + align:start position:0% +okay and you have some resolution in +theta some resolution and x + + align:start position:0% +theta some resolution and x + + + align:start position:0% +theta some resolution and x +and if i don't use the right foot camera + + align:start position:0% +and if i don't use the right foot camera + + + align:start position:0% +and if i don't use the right foot camera +i have four thousand pieces + + align:start position:0% +i have four thousand pieces + + + align:start position:0% +i have four thousand pieces +if i place + + align:start position:0% +if i place + + + align:start position:0% +if i place +a light fill and let's say under each + + align:start position:0% +a light fill and let's say under each + + + align:start position:0% +a light fill and let's say under each +lens i get 10 pixels here + + align:start position:0% +lens i get 10 pixels here + + + align:start position:0% +lens i get 10 pixels here +i'm subdividing my lens into 10 zones + + align:start position:0% +i'm subdividing my lens into 10 zones + + + align:start position:0% +i'm subdividing my lens into 10 zones +right and my actual resolution is only + + align:start position:0% +right and my actual resolution is only + + + align:start position:0% +right and my actual resolution is only +400 so i have length slits going from 1 + + align:start position:0% +400 so i have length slits going from 1 + + + align:start position:0% +400 so i have length slits going from 1 +to 400 + + align:start position:0% +to 400 + + + align:start position:0% +to 400 +and under each transfer i have a pixel + + align:start position:0% +and under each transfer i have a pixel + + + align:start position:0% +and under each transfer i have a pixel +that's i have 10 pixels + + align:start position:0% +that's i have 10 pixels + + + align:start position:0% +that's i have 10 pixels +so in that sense my resolution in x is + + align:start position:0% +so in that sense my resolution in x is + + + align:start position:0% +so in that sense my resolution in x is +400 and the solution of theta is 10 + + align:start position:0% +400 and the solution of theta is 10 + + + align:start position:0% +400 and the solution of theta is 10 +and you can see that in the x theta + + align:start position:0% +and you can see that in the x theta + + + align:start position:0% +and you can see that in the x theta +space + + align:start position:0% + + + + align:start position:0% + +it's this way so this is only 10 + + align:start position:0% +it's this way so this is only 10 + + + align:start position:0% +it's this way so this is only 10 +and this is + + align:start position:0% + + + + align:start position:0% + +measurements + + align:start position:0% +measurements + + + align:start position:0% +measurements +and i need to distribute that + + align:start position:0% +and i need to distribute that + + + align:start position:0% +and i need to distribute that +in a typical sensor all of them will go + + align:start position:0% + + + + align:start position:0% + +exactly for one + + align:start position:0% +exactly for one + + + align:start position:0% +exactly for one +there is no theta resolution so i will + + align:start position:0% +there is no theta resolution so i will + + + align:start position:0% +there is no theta resolution so i will +have fourth of the pixels + + align:start position:0% +have fourth of the pixels + + + align:start position:0% +have fourth of the pixels +but no resolution and theta + + align:start position:0% +but no resolution and theta + + + align:start position:0% +but no resolution and theta +in a light fit camera i could have 400 + + align:start position:0% +in a light fit camera i could have 400 + + + align:start position:0% +in a light fit camera i could have 400 +pixels and theta resolution of 10 + + align:start position:0% +pixels and theta resolution of 10 + + + align:start position:0% +pixels and theta resolution of 10 +or i could go + + align:start position:0% +or i could go + + + align:start position:0% +or i could go +in in other directions where maybe this + + align:start position:0% +in in other directions where maybe this + + + align:start position:0% +in in other directions where maybe this +is even thicker and more thicker + + align:start position:0% +is even thicker and more thicker + + + align:start position:0% +is even thicker and more thicker +i could do + + align:start position:0% + + + + align:start position:0% + +how far can i keep going so i started + + align:start position:0% +how far can i keep going so i started + + + align:start position:0% +how far can i keep going so i started +something very thin it's bad it's + + align:start position:0% +something very thin it's bad it's + + + align:start position:0% +something very thin it's bad it's +getting fatter with a total number of + + align:start position:0% +getting fatter with a total number of + + + align:start position:0% +getting fatter with a total number of +samples + + align:start position:0% + + + + align:start position:0% + +if i get rid of this main lens + + align:start position:0% + + + + align:start position:0% + +i'll give you a hint what you're + + align:start position:0% +i'll give you a hint what you're + + + align:start position:0% +i'll give you a hint what you're +indicating + + align:start position:0% +indicating + + + align:start position:0% +indicating +is + + align:start position:0% +is + + + align:start position:0% +is +the opposite you get + + align:start position:0% + + + + align:start position:0% + +so you have flipped + + align:start position:0% +so you have flipped + + + align:start position:0% +so you have flipped +from this condition this situation + + align:start position:0% +from this condition this situation + + + align:start position:0% +from this condition this situation +because now what we have is if i have a + + align:start position:0% +because now what we have is if i have a + + + align:start position:0% +because now what we have is if i have a +word out here + + align:start position:0% +word out here + + + align:start position:0% +word out here +x + + align:start position:0% +x + + + align:start position:0% +x +then from every point + + align:start position:0% + + + + align:start position:0% + +i can resolve this theta to + + align:start position:0% +i can resolve this theta to + + + align:start position:0% +i can resolve this theta to +400 different lenses so this one is one + + align:start position:0% + + + + align:start position:0% + +i can measure light coming out of this + + align:start position:0% +i can measure light coming out of this + + + align:start position:0% +i can measure light coming out of this +point in 400 different directions + + align:start position:0% + + + + align:start position:0% + +but under each only had some fixes + + align:start position:0% +but under each only had some fixes + + + align:start position:0% +but under each only had some fixes +so this is what i got + + align:start position:0% +so this is what i got + + + align:start position:0% +so this is what i got +so the key lesson here + + align:start position:0% +so the key lesson here + + + align:start position:0% +so the key lesson here +is that a lens + + align:start position:0% + + + + align:start position:0% + +and without a lens we are basically + + align:start position:0% +and without a lens we are basically + + + align:start position:0% +and without a lens we are basically +flipping + + align:start position:0% +flipping + + + align:start position:0% +flipping +the resolution in x and theta + + align:start position:0% +the resolution in x and theta + + + align:start position:0% +the resolution in x and theta +if you have less you get more special + + align:start position:0% +if you have less you get more special + + + align:start position:0% +if you have less you get more special +resolution but a little bit angle of + + align:start position:0% +resolution but a little bit angle of + + + align:start position:0% +resolution but a little bit angle of +position which is an ideal case the + + align:start position:0% +position which is an ideal case the + + + align:start position:0% +position which is an ideal case the +world doesn't change that much if you + + align:start position:0% +world doesn't change that much if you + + + align:start position:0% +world doesn't change that much if you +change the viewpoint + + align:start position:0% +change the viewpoint + + + align:start position:0% +change the viewpoint +but in certain case scenarios as we see + + align:start position:0% +but in certain case scenarios as we see + + + align:start position:0% +but in certain case scenarios as we see +that there + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +is very far away right + + align:start position:0% +is very far away right + + + align:start position:0% +is very far away right +i don't need to sample this point in + + align:start position:0% +i don't need to sample this point in + + + align:start position:0% +i don't need to sample this point in +4000 different directions 400 different + + align:start position:0% +4000 different directions 400 different + + + align:start position:0% +4000 different directions 400 different +directions i'm getting a sample in 10 + + align:start position:0% +directions i'm getting a sample in 10 + + + align:start position:0% +directions i'm getting a sample in 10 +different directions + + align:start position:0% +different directions + + + align:start position:0% +different directions +and then having the lenses + + align:start position:0% +and then having the lenses + + + align:start position:0% +and then having the lenses +okay + + align:start position:0% +okay + + + align:start position:0% +okay +but what note is saying is i can start + + align:start position:0% +but what note is saying is i can start + + + align:start position:0% +but what note is saying is i can start +coming closer + + align:start position:0% +coming closer + + + align:start position:0% +coming closer +a bit longer very close now + + align:start position:0% + + + + align:start position:0% + +those 400 directions are sufficiently + + align:start position:0% +those 400 directions are sufficiently + + + align:start position:0% +those 400 directions are sufficiently +wide + + align:start position:0% +wide + + + align:start position:0% +wide +they're spanning + + align:start position:0% +they're spanning + + + align:start position:0% +they're spanning +more times + + align:start position:0% +more times + + + align:start position:0% +more times +and it's become really really close + + align:start position:0% +and it's become really really close + + + align:start position:0% +and it's become really really close +right and it's almost minus one + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +then i really want to see all these + + align:start position:0% + + + + align:start position:0% + +directions + + align:start position:0% + + + + align:start position:0% + +and then the analogy of what happens + + align:start position:0% +and then the analogy of what happens + + + align:start position:0% +and then the analogy of what happens +when you go from here to here + + align:start position:0% +when you go from here to here + + + align:start position:0% +when you go from here to here +is that remember the length system will + + align:start position:0% +is that remember the length system will + + + align:start position:0% +is that remember the length system will +do a very good job of mapping a 4d light + + align:start position:0% +do a very good job of mapping a 4d light + + + align:start position:0% +do a very good job of mapping a 4d light +fluid + + align:start position:0% +fluid + + + align:start position:0% +fluid +for the real world + + align:start position:0% +for the real world + + + align:start position:0% +for the real world +into a 4d light thread + + align:start position:0% +into a 4d light thread + + + align:start position:0% +into a 4d light thread +on the on the inside inside the camera + + align:start position:0% +on the on the inside inside the camera + + + align:start position:0% +on the on the inside inside the camera +and again again hologram + + align:start position:0% +and again again hologram + + + align:start position:0% +and again again hologram +but when you don't have lines + + align:start position:0% +but when you don't have lines + + + align:start position:0% +but when you don't have lines +that's not true anymore + + align:start position:0% +that's not true anymore + + + align:start position:0% +that's not true anymore +you have a light fit + + align:start position:0% +you have a light fit + + + align:start position:0% +you have a light fit +here and have a similar light fill here + + align:start position:0% +here and have a similar light fill here + + + align:start position:0% +here and have a similar light fill here +for this plane + + align:start position:0% +for this plane + + + align:start position:0% +for this plane +like you imagine you put a holographic + + align:start position:0% +like you imagine you put a holographic + + + align:start position:0% +like you imagine you put a holographic +and the hologram has exactly 10 + + align:start position:0% +and the hologram has exactly 10 + + + align:start position:0% +and the hologram has exactly 10 +directions + + align:start position:0% +directions + + + align:start position:0% +directions +so it's a 400 pixel program it has + + align:start position:0% +so it's a 400 pixel program it has + + + align:start position:0% +so it's a 400 pixel program it has +exactly 10 directions + + align:start position:0% +exactly 10 directions + + + align:start position:0% +exactly 10 directions +if i want to capture that i should try + + align:start position:0% +if i want to capture that i should try + + + align:start position:0% +if i want to capture that i should try +and see + + align:start position:0% +and see + + + align:start position:0% +and see +but if i have a hologram + + align:start position:0% +but if i have a hologram + + + align:start position:0% +but if i have a hologram +where + + align:start position:0% +where + + + align:start position:0% +where +i have only 10 pixels + + align:start position:0% +i have only 10 pixels + + + align:start position:0% +i have only 10 pixels +and it has 400 different directions i'm + + align:start position:0% +and it has 400 different directions i'm + + + align:start position:0% +and it has 400 different directions i'm +so close to it + + align:start position:0% +so close to it + + + align:start position:0% +so close to it +then it makes sense to get another lens + + align:start position:0% +then it makes sense to get another lens + + + align:start position:0% +then it makes sense to get another lens +so in microscopy and so on + + align:start position:0% + + + + align:start position:0% + +so uh mark lovato has done some work in + + align:start position:0% +so uh mark lovato has done some work in + + + align:start position:0% +so uh mark lovato has done some work in +life in + + align:start position:0% +life in + + + align:start position:0% +life in +in microscopes + + align:start position:0% +in microscopes + + + align:start position:0% +in microscopes +it uses different modifications + + align:start position:0% + + + + align:start position:0% + +and the example that we saw for um + + align:start position:0% +and the example that we saw for um + + + align:start position:0% +and the example that we saw for um +shot curtain on the sensor for + + align:start position:0% +shot curtain on the sensor for + + + align:start position:0% +shot curtain on the sensor for +looking at the apparition of a point + + align:start position:0% +looking at the apparition of a point + + + align:start position:0% +looking at the apparition of a point +light they didn't use the mainland + + align:start position:0% +light they didn't use the mainland + + + align:start position:0% +light they didn't use the mainland +because i expected to see + + align:start position:0% +because i expected to see + + + align:start position:0% +because i expected to see +a point that's very very far away + + align:start position:0% +a point that's very very far away + + + align:start position:0% +a point that's very very far away +but they're not they're not interested + + align:start position:0% +but they're not they're not interested + + + align:start position:0% +but they're not they're not interested +in taking an image of the point with the + + align:start position:0% +in taking an image of the point with the + + + align:start position:0% +in taking an image of the point with the +setup they're just interested in finding + + align:start position:0% +setup they're just interested in finding + + + align:start position:0% +setup they're just interested in finding +the operation + + align:start position:0% +the operation + + + align:start position:0% +the operation +so if you have a point very far away and + + align:start position:0% +so if you have a point very far away and + + + align:start position:0% +so if you have a point very far away and +the waves are coming straight i don't + + align:start position:0% +the waves are coming straight i don't + + + align:start position:0% +the waves are coming straight i don't +need a main lens if you're coming + + align:start position:0% +need a main lens if you're coming + + + align:start position:0% +need a main lens if you're coming +straight all the images are the center + + align:start position:0% +straight all the images are the center + + + align:start position:0% +straight all the images are the center +and with elaboration + + align:start position:0% +and with elaboration + + + align:start position:0% +and with elaboration +the + + align:start position:0% +the + + + align:start position:0% +the +sharp images are offset + + align:start position:0% +sharp images are offset + + + align:start position:0% +sharp images are offset +so there are many configurations when + + align:start position:0% +so there are many configurations when + + + align:start position:0% +so there are many configurations when +you + + align:start position:0% +you + + + align:start position:0% +you +when you + + align:start position:0% +when you + + + align:start position:0% +when you +can decide + + align:start position:0% + + + + align:start position:0% + +and one thought experiment for you would + + align:start position:0% +and one thought experiment for you would + + + align:start position:0% +and one thought experiment for you would +be + + align:start position:0% +be + + + align:start position:0% +be +what happens if there is more than one + + align:start position:0% +what happens if there is more than one + + + align:start position:0% +what happens if there is more than one +less element or more than one answer + + align:start position:0% + + + + align:start position:0% + +so you should look up something called + + align:start position:0% +so you should look up something called + + + align:start position:0% +so you should look up something called +the poor + + align:start position:0% +the poor + + + align:start position:0% +the poor +superlets + + align:start position:0% + + + + align:start position:0% + +it's a very fun + + align:start position:0% +it's a very fun + + + align:start position:0% +it's a very fun +um + + align:start position:0% + + + + align:start position:0% + +and it has very interesting properties + + align:start position:0% +and it has very interesting properties + + + align:start position:0% +and it has very interesting properties +because the focal length of that lens is + + align:start position:0% +because the focal length of that lens is + + + align:start position:0% +because the focal length of that lens is +dependent on the depth + + align:start position:0% +dependent on the depth + + + align:start position:0% +dependent on the depth +in a traditional lens + + align:start position:0% +in a traditional lens + + + align:start position:0% +in a traditional lens +it bends it copies of the light field + + align:start position:0% +it bends it copies of the light field + + + align:start position:0% +it bends it copies of the light field +from its side of the right hand side + + align:start position:0% +from its side of the right hand side + + + align:start position:0% +from its side of the right hand side +but for the cover support lens + + align:start position:0% +but for the cover support lens + + + align:start position:0% +but for the cover support lens +it does have a strange transformation + + align:start position:0% +it does have a strange transformation + + + align:start position:0% +it does have a strange transformation +i think + + align:start position:0% + + + + align:start position:0% + +and once you start thinking about + + align:start position:0% +and once you start thinking about + + + align:start position:0% +and once you start thinking about +uh the world as not just 2d but 4d + + align:start position:0% +uh the world as not just 2d but 4d + + + align:start position:0% +uh the world as not just 2d but 4d +and + + align:start position:0% +and + + + align:start position:0% +and +a photograph having not just a position + + align:start position:0% +a photograph having not just a position + + + align:start position:0% +a photograph having not just a position +coordinate but also an angle coordinate + + align:start position:0% +coordinate but also an angle coordinate + + + align:start position:0% +coordinate but also an angle coordinate +you realize there are lots of other + + align:start position:0% +you realize there are lots of other + + + align:start position:0% +you realize there are lots of other +examples + + align:start position:0% +examples + + + align:start position:0% +examples +where this 4d representation starts + + align:start position:0% +where this 4d representation starts + + + align:start position:0% +where this 4d representation starts +making sense + + align:start position:0% +making sense + + + align:start position:0% +making sense +so near the end of the semester we'll be + + align:start position:0% +so near the end of the semester we'll be + + + align:start position:0% +so near the end of the semester we'll be +studying + + align:start position:0% +studying + + + align:start position:0% +studying +medical imaging and scientific imaging + + align:start position:0% +medical imaging and scientific imaging + + + align:start position:0% +medical imaging and scientific imaging +uh using tomography and and + + align:start position:0% +uh using tomography and and + + + align:start position:0% +uh using tomography and and +deconvolution and so on and all those + + align:start position:0% +deconvolution and so on and all those + + + align:start position:0% +deconvolution and so on and all those +concepts you know cat scan machine they + + align:start position:0% +concepts you know cat scan machine they + + + align:start position:0% +concepts you know cat scan machine they +all work on this principle + + align:start position:0% +all work on this principle + + + align:start position:0% +all work on this principle +of being sensitive to position as well + + align:start position:0% +of being sensitive to position as well + + + align:start position:0% +of being sensitive to position as well +as angle + + align:start position:0% +as angle + + + align:start position:0% +as angle +so in case of a flat scan machine + + align:start position:0% +so in case of a flat scan machine + + + align:start position:0% +so in case of a flat scan machine +you have + + align:start position:0% + + + + align:start position:0% + +basically have + + align:start position:0% +basically have + + + align:start position:0% +basically have +a + + align:start position:0% + + + + align:start position:0% + +but what is it doing inside it has + + align:start position:0% +but what is it doing inside it has + + + align:start position:0% +but what is it doing inside it has +a set of detectors + + align:start position:0% +a set of detectors + + + align:start position:0% +a set of detectors +and an emitter + + align:start position:0% +and an emitter + + + align:start position:0% +and an emitter +and your head is in here + + align:start position:0% +and your head is in here + + + align:start position:0% +and your head is in here +you turn on this x-ray source + + align:start position:0% +you turn on this x-ray source + + + align:start position:0% +you turn on this x-ray source +and you take this image + + align:start position:0% +and you take this image + + + align:start position:0% +and you take this image +take + + align:start position:0% + + + + align:start position:0% + +then you move this light source + + align:start position:0% +then you move this light source + + + align:start position:0% +then you move this light source +and you take new shots + + align:start position:0% + + + + align:start position:0% + +and this is basically capturing the + + align:start position:0% +and this is basically capturing the + + + align:start position:0% +and this is basically capturing the +light frame of the body using excess + + align:start position:0% + + + + align:start position:0% + +to simplify this diagram + + align:start position:0% +to simplify this diagram + + + align:start position:0% +to simplify this diagram +imagine this is flat + + align:start position:0% + + + + align:start position:0% + +and in case of x-rays the source is + + align:start position:0% +and in case of x-rays the source is + + + align:start position:0% +and in case of x-rays the source is +moving and the sensors are moving + + align:start position:0% + + + + align:start position:0% + +but to simplify this diagram imagine i + + align:start position:0% +but to simplify this diagram imagine i + + + align:start position:0% +but to simplify this diagram imagine i +flattened this set of pixels + + align:start position:0% +flattened this set of pixels + + + align:start position:0% +flattened this set of pixels +and i put the lights at + + align:start position:0% +and i put the lights at + + + align:start position:0% +and i put the lights at +different positions + + align:start position:0% + + + + align:start position:0% + +can be represented in the exterior space + + align:start position:0% + + + + align:start position:0% + +and then it turns out that there is + + align:start position:0% +and then it turns out that there is + + + align:start position:0% +and then it turns out that there is +redundancy in your space + + align:start position:0% +redundancy in your space + + + align:start position:0% +redundancy in your space +such as if you have a voxel + + align:start position:0% +such as if you have a voxel + + + align:start position:0% +such as if you have a voxel +inside your body and independent of + + align:start position:0% +inside your body and independent of + + + align:start position:0% +inside your body and independent of +which direction the x-ray comes in + + align:start position:0% +which direction the x-ray comes in + + + align:start position:0% +which direction the x-ray comes in +which attenuates the same factor so + + align:start position:0% +which attenuates the same factor so + + + align:start position:0% +which attenuates the same factor so +there's bone or muscle or or blood + + align:start position:0% +there's bone or muscle or or blood + + + align:start position:0% +there's bone or muscle or or blood +then + + align:start position:0% +then + + + align:start position:0% +then +although your like field is four + + align:start position:0% +although your like field is four + + + align:start position:0% +although your like field is four +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +the inherent data + + align:start position:0% +the inherent data + + + align:start position:0% +the inherent data +is only two or three dimension + + align:start position:0% +is only two or three dimension + + + align:start position:0% +is only two or three dimension +and so you can invert that and recover + + align:start position:0% +and so you can invert that and recover + + + align:start position:0% +and so you can invert that and recover +the opacity of each false + + align:start position:0% + + + + align:start position:0% + +so the same thing + + align:start position:0% +so the same thing + + + align:start position:0% +so the same thing +can be done with lightsaber + + align:start position:0% +can be done with lightsaber + + + align:start position:0% +can be done with lightsaber +if you capture this four-dimensional + + align:start position:0% +if you capture this four-dimensional + + + align:start position:0% +if you capture this four-dimensional +light fluid now you can go back + + align:start position:0% +light fluid now you can go back + + + align:start position:0% +light fluid now you can go back +and estimate the depth of every point in + + align:start position:0% +and estimate the depth of every point in + + + align:start position:0% +and estimate the depth of every point in +the scene + + align:start position:0% +the scene + + + align:start position:0% +the scene +so typically you use a stereo pair + + align:start position:0% +so typically you use a stereo pair + + + align:start position:0% +so typically you use a stereo pair +there's two cameras you can try to do + + align:start position:0% +there's two cameras you can try to do + + + align:start position:0% +there's two cameras you can try to do +some + + align:start position:0% + + + + align:start position:0% + +correlation to estimate correspondence + + align:start position:0% +correlation to estimate correspondence + + + align:start position:0% +correlation to estimate correspondence +and a triangulation estimate + + align:start position:0% +and a triangulation estimate + + + align:start position:0% +and a triangulation estimate +but in your second assignment + + align:start position:0% +but in your second assignment + + + align:start position:0% +but in your second assignment +what you're going to do is capture the + + align:start position:0% +what you're going to do is capture the + + + align:start position:0% +what you're going to do is capture the +light field and directly from the light + + align:start position:0% +light field and directly from the light + + + align:start position:0% +light field and directly from the light +field estimate + + align:start position:0% + + + + align:start position:0% + +and the way you will do that is you'll + + align:start position:0% +and the way you will do that is you'll + + + align:start position:0% +and the way you will do that is you'll +basically line up those images + + align:start position:0% + + + + align:start position:0% + +if the point is in sharp focus the digit + + align:start position:0% +if the point is in sharp focus the digit + + + align:start position:0% +if the point is in sharp focus the digit +will be focusing all these values here + + align:start position:0% +will be focusing all these values here + + + align:start position:0% +will be focusing all these values here +will look the same + + align:start position:0% + + + + align:start position:0% + +but if something is out of focus you + + align:start position:0% +but if something is out of focus you + + + align:start position:0% +but if something is out of focus you +need to shift and add + + align:start position:0% +need to shift and add + + + align:start position:0% +need to shift and add +right so you'll have to share it at some + + align:start position:0% +right so you'll have to share it at some + + + align:start position:0% +right so you'll have to share it at some +point + + align:start position:0% + + + + align:start position:0% + +and then all these values will be + + align:start position:0% +and then all these values will be + + + align:start position:0% +and then all these values will be +concerned + + align:start position:0% + + + + align:start position:0% + +and the fact that all the values are the + + align:start position:0% +and the fact that all the values are the + + + align:start position:0% +and the fact that all the values are the +same + + align:start position:0% +same + + + align:start position:0% +same +indicates that now you can achieve a + + align:start position:0% +indicates that now you can achieve a + + + align:start position:0% +indicates that now you can achieve a +digital difference + + align:start position:0% + + + + align:start position:0% + +so that's a great point so think about + + align:start position:0% +so that's a great point so think about + + + align:start position:0% +so that's a great point so think about +you have a point + + align:start position:0% +you have a point + + + align:start position:0% +you have a point +which is at different depths + + align:start position:0% +which is at different depths + + + align:start position:0% +which is at different depths +and you're saying that + + align:start position:0% +and you're saying that + + + align:start position:0% +and you're saying that +in flatland + + align:start position:0% +in flatland + + + align:start position:0% +in flatland +at the top of the image we shouldn't + + align:start position:0% +at the top of the image we shouldn't + + + align:start position:0% +at the top of the image we shouldn't +focus here in the middle of the + + align:start position:0% +focus here in the middle of the + + + align:start position:0% +focus here in the middle of the +dimension focus here and so on + + align:start position:0% +dimension focus here and so on + + + align:start position:0% +dimension focus here and so on +right so this is my plane or surface or + + align:start position:0% +right so this is my plane or surface or + + + align:start position:0% +right so this is my plane or surface or +focus rather than than this + + align:start position:0% +focus rather than than this + + + align:start position:0% +focus rather than than this +so all you have to do + + align:start position:0% +so all you have to do + + + align:start position:0% +so all you have to do +is for the top point + + align:start position:0% +is for the top point + + + align:start position:0% +is for the top point +right + + align:start position:0% +right + + + align:start position:0% +right +you have to keep a little bit more + + align:start position:0% +you have to keep a little bit more + + + align:start position:0% +you have to keep a little bit more +you have to do but i'll give you a very + + align:start position:0% +you have to do but i'll give you a very + + + align:start position:0% +you have to do but i'll give you a very +very high level flavor of pollution to + + align:start position:0% +very high level flavor of pollution to + + + align:start position:0% +very high level flavor of pollution to +this + + align:start position:0% +this + + + align:start position:0% +this +for this point + + align:start position:0% +for this point + + + align:start position:0% +for this point +for this + + align:start position:0% +for this + + + align:start position:0% +for this +we have a lens here + + align:start position:0% +we have a lens here + + + align:start position:0% +we have a lens here +for this particular direction + + align:start position:0% + + + + align:start position:0% + +multiple + + align:start position:0% +multiple + + + align:start position:0% +multiple +cameras right for this particular + + align:start position:0% +cameras right for this particular + + + align:start position:0% +cameras right for this particular +direction you can just + + align:start position:0% +direction you can just + + + align:start position:0% +direction you can just +calibrate your world you put a box + + align:start position:0% +calibrate your world you put a box + + + align:start position:0% +calibrate your world you put a box +you know one meter wide and i can say + + align:start position:0% +you know one meter wide and i can say + + + align:start position:0% +you know one meter wide and i can say +within this box + + align:start position:0% +within this box + + + align:start position:0% +within this box +at the top left + + align:start position:0% +at the top left + + + align:start position:0% +at the top left +i want to be the focus to be in the top + + align:start position:0% +i want to be the focus to be in the top + + + align:start position:0% +i want to be the focus to be in the top +left the middle + + align:start position:0% +left the middle + + + align:start position:0% +left the middle +in the back of the frame and + + align:start position:0% +in the back of the frame and + + + align:start position:0% +in the back of the frame and +you just kind of did that + + align:start position:0% +you just kind of did that + + + align:start position:0% +you just kind of did that +you can move the camera + + align:start position:0% + + + + align:start position:0% + +and say that all the rays that go here + + align:start position:0% +and say that all the rays that go here + + + align:start position:0% +and say that all the rays that go here +i'm going to add + + align:start position:0% +i'm going to add + + + align:start position:0% +i'm going to add +up but for the next pixel i'm not going + + align:start position:0% +up but for the next pixel i'm not going + + + align:start position:0% +up but for the next pixel i'm not going +to add up all those radar mode adders in + + align:start position:0% +to add up all those radar mode adders in + + + align:start position:0% +to add up all those radar mode adders in +other ways + + align:start position:0% + + + + align:start position:0% + +how do we issue that in the next three + + align:start position:0% +how do we issue that in the next three + + + align:start position:0% +how do we issue that in the next three +dozens + + align:start position:0% +dozens + + + align:start position:0% +dozens +we know that for a point here + + align:start position:0% +we know that for a point here + + + align:start position:0% +we know that for a point here +there will be some + + align:start position:0% +there will be some + + + align:start position:0% +there will be some +value over here + + align:start position:0% +value over here + + + align:start position:0% +value over here +but for a point here + + align:start position:0% +but for a point here + + + align:start position:0% +but for a point here +there is some kind of a slope + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +if i just wanted to create an image + + align:start position:0% +if i just wanted to create an image + + + align:start position:0% +if i just wanted to create an image +as + + align:start position:0% +as + + + align:start position:0% +as +so let's take something very concrete if + + align:start position:0% +so let's take something very concrete if + + + align:start position:0% +so let's take something very concrete if +i were to focus on infinity i know i + + align:start position:0% +i were to focus on infinity i know i + + + align:start position:0% +i were to focus on infinity i know i +should just protect it straight up i + + align:start position:0% +should just protect it straight up i + + + align:start position:0% +should just protect it straight up i +just sum up everything along vertical + + align:start position:0% +just sum up everything along vertical + + + align:start position:0% +just sum up everything along vertical +mass + + align:start position:0% +mass + + + align:start position:0% +mass +if i want to + + align:start position:0% +if i want to + + + align:start position:0% +if i want to +focus somewhere closer i need to share + + align:start position:0% +focus somewhere closer i need to share + + + align:start position:0% +focus somewhere closer i need to share +this so i'm going to take this + + align:start position:0% + + + + align:start position:0% + +and keep the event same space like that + + align:start position:0% +and keep the event same space like that + + + align:start position:0% +and keep the event same space like that +and i'm going to sum up these values + + align:start position:0% +and i'm going to sum up these values + + + align:start position:0% +and i'm going to sum up these values +okay and store the value i'm going to + + align:start position:0% +okay and store the value i'm going to + + + align:start position:0% +okay and store the value i'm going to +sum up these values and this means i'm + + align:start position:0% +sum up these values and this means i'm + + + align:start position:0% +sum up these values and this means i'm +focusing at this point + + align:start position:0% +focusing at this point + + + align:start position:0% +focusing at this point +if you want to focus on a slightly + + align:start position:0% +if you want to focus on a slightly + + + align:start position:0% +if you want to focus on a slightly +different plane + + align:start position:0% +different plane + + + align:start position:0% +different plane +then + + align:start position:0% + + + + align:start position:0% + +it's vertical is slanted for the focus + + align:start position:0% +it's vertical is slanted for the focus + + + align:start position:0% +it's vertical is slanted for the focus +of some other plane + + align:start position:0% +of some other plane + + + align:start position:0% +of some other plane +is + + align:start position:0% + + + + align:start position:0% + +so now your question is how can i do it + + align:start position:0% +so now your question is how can i do it + + + align:start position:0% +so now your question is how can i do it +differently for different pieces + + align:start position:0% +differently for different pieces + + + align:start position:0% +differently for different pieces +so on the edges i will just do vertical + + align:start position:0% +so on the edges i will just do vertical + + + align:start position:0% +so on the edges i will just do vertical +protection + + align:start position:0% +protection + + + align:start position:0% +protection +right in the middle i will do a standard + + align:start position:0% +right in the middle i will do a standard + + + align:start position:0% +right in the middle i will do a standard +protection + + align:start position:0% +protection + + + align:start position:0% +protection +and for all the places in between i will + + align:start position:0% +and for all the places in between i will + + + align:start position:0% +and for all the places in between i will +do + + align:start position:0% +do + + + align:start position:0% +do +less climbing + + align:start position:0% + + + + align:start position:0% + +and then i'll come back + + align:start position:0% + + + + align:start position:0% + +and you can imagine all the crazy tricks + + align:start position:0% +and you can imagine all the crazy tricks + + + align:start position:0% +and you can imagine all the crazy tricks +you can do + + align:start position:0% +you can do + + + align:start position:0% +you can do +so one part of your assignment + + align:start position:0% +so one part of your assignment + + + align:start position:0% +so one part of your assignment +you're going to look at + + align:start position:0% +you're going to look at + + + align:start position:0% +you're going to look at +you're going to look at + + align:start position:0% +you're going to look at + + + align:start position:0% +you're going to look at +you would have a seat + + align:start position:0% +you would have a seat + + + align:start position:0% +you would have a seat +and for that what i recommend you to do + + align:start position:0% +and for that what i recommend you to do + + + align:start position:0% +and for that what i recommend you to do +is + + align:start position:0% + + + + align:start position:0% + +take your area of cameras + + align:start position:0% + + + + align:start position:0% + +and then create some kind of offense + + align:start position:0% +and then create some kind of offense + + + align:start position:0% +and then create some kind of offense +here + + align:start position:0% + + + + align:start position:0% + +okay so in + + align:start position:0% +okay so in + + + align:start position:0% +okay so in +real world i'm guessing there's some + + align:start position:0% +real world i'm guessing there's some + + + align:start position:0% +real world i'm guessing there's some +kind of + + align:start position:0% + + + + align:start position:0% + +it is a see-through part + + align:start position:0% +it is a see-through part + + + align:start position:0% +it is a see-through part +and then there is some book or some + + align:start position:0% +and then there is some book or some + + + align:start position:0% +and then there is some book or some +painting back here + + align:start position:0% + + + + align:start position:0% + +and you're going to take 16 images + + align:start position:0% +and you're going to take 16 images + + + align:start position:0% +and you're going to take 16 images +and you'll and this is red and this is + + align:start position:0% +and you'll and this is red and this is + + + align:start position:0% +and you'll and this is red and this is +green + + align:start position:0% + + + + align:start position:0% + +uh purely by focusing on the background + + align:start position:0% +uh purely by focusing on the background + + + align:start position:0% +uh purely by focusing on the background +so when you focus on the foreground you + + align:start position:0% +so when you focus on the foreground you + + + align:start position:0% +so when you focus on the foreground you +have to maybe shift the three pieces + + align:start position:0% +have to maybe shift the three pieces + + + align:start position:0% +have to maybe shift the three pieces +and shift on the + + align:start position:0% + + + + align:start position:0% + +background but + + align:start position:0% +background but + + + align:start position:0% +background but +uh as an extra credit what you can do is + + align:start position:0% +uh as an extra credit what you can do is + + + align:start position:0% +uh as an extra credit what you can do is +not just refocus + + align:start position:0% +not just refocus + + + align:start position:0% +not just refocus +but also do some analysis + + align:start position:0% +but also do some analysis + + + align:start position:0% +but also do some analysis +of + + align:start position:0% +of + + + align:start position:0% +of +uh when you when you shift and add those + + align:start position:0% +uh when you when you shift and add those + + + align:start position:0% +uh when you when you shift and add those +pixels if all those pixels have the same + + align:start position:0% +pixels if all those pixels have the same + + + align:start position:0% +pixels if all those pixels have the same +value or not + + align:start position:0% +value or not + + + align:start position:0% +value or not +so + + align:start position:0% +so + + + align:start position:0% +so +if the red object wasn't there and just + + align:start position:0% +if the red object wasn't there and just + + + align:start position:0% +if the red object wasn't there and just +focus on the green + + align:start position:0% +focus on the green + + + align:start position:0% +focus on the green +all the pixels here + + align:start position:0% +all the pixels here + + + align:start position:0% +all the pixels here +will be green + + align:start position:0% +will be green + + + align:start position:0% +will be green +all these values will be green + + align:start position:0% + + + + align:start position:0% + +but if you have some object here some of + + align:start position:0% +but if you have some object here some of + + + align:start position:0% +but if you have some object here some of +these objects some of these pixels will + + align:start position:0% +these objects some of these pixels will + + + align:start position:0% +these objects some of these pixels will +be written + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +here this + + align:start position:0% +here this + + + align:start position:0% +here this +type the is + + align:start position:0% +type the is + + + align:start position:0% +type the is +number + + align:start position:0% +number + + + align:start position:0% +number +and access to the cameras + + align:start position:0% +and access to the cameras + + + align:start position:0% +and access to the cameras +so the image from the first camera + + align:start position:0% +so the image from the first camera + + + align:start position:0% +so the image from the first camera +is placed here + + align:start position:0% +is placed here + + + align:start position:0% +is placed here +the image from the second camera goes + + align:start position:0% +the image from the second camera goes + + + align:start position:0% +the image from the second camera goes +here + + align:start position:0% + + + + align:start position:0% + +and because you're doing this problem + + align:start position:0% +and because you're doing this problem + + + align:start position:0% +and because you're doing this problem +only in one d every row is independent + + align:start position:0% +only in one d every row is independent + + + align:start position:0% +only in one d every row is independent +so think of this as on the center row of + + align:start position:0% +so think of this as on the center row of + + + align:start position:0% +so think of this as on the center row of +each of the system channels + + align:start position:0% + + + + align:start position:0% + +okay so going back to this example of + + align:start position:0% +okay so going back to this example of + + + align:start position:0% +okay so going back to this example of +redwater cream + + align:start position:0% +redwater cream + + + align:start position:0% +redwater cream +you when you try to sample it + + align:start position:0% +you when you try to sample it + + + align:start position:0% +you when you try to sample it +you'll see that you can refocus on green + + align:start position:0% +you'll see that you can refocus on green + + + align:start position:0% +you'll see that you can refocus on green +and the object will look mostly green + + align:start position:0% +and the object will look mostly green + + + align:start position:0% +and the object will look mostly green +but then there's some reds + + align:start position:0% + + + + align:start position:0% + +but then you can do very simple + + align:start position:0% +but then you can do very simple + + + align:start position:0% +but then you can do very simple +outlier rejection and let's say 16 + + align:start position:0% +outlier rejection and let's say 16 + + + align:start position:0% +outlier rejection and let's say 16 +cameras and only four of them so + + align:start position:0% +cameras and only four of them so + + + align:start position:0% +cameras and only four of them so +12 of those are green and only four of + + align:start position:0% +12 of those are green and only four of + + + align:start position:0% +12 of those are green and only four of +those are red + + align:start position:0% +those are red + + + align:start position:0% +those are red +you don't understand all 16. + + align:start position:0% +you don't understand all 16. + + + align:start position:0% +you don't understand all 16. +you can say what's my + + align:start position:0% +you can say what's my + + + align:start position:0% +you can say what's my +what's the color that's in my character + + align:start position:0% +what's the color that's in my character + + + align:start position:0% +what's the color that's in my character +and that color is green + + align:start position:0% +and that color is green + + + align:start position:0% +and that color is green +so you will not get a reddish tinge + + align:start position:0% +so you will not get a reddish tinge + + + align:start position:0% +so you will not get a reddish tinge +to your to your photo but you'll get + + align:start position:0% +to your to your photo but you'll get + + + align:start position:0% +to your to your photo but you'll get +crowded quality + + align:start position:0% +crowded quality + + + align:start position:0% +crowded quality +it's not a simple linear projection it's + + align:start position:0% +it's not a simple linear projection it's + + + align:start position:0% +it's not a simple linear projection it's +not just the sum of the pixels + + align:start position:0% +not just the sum of the pixels + + + align:start position:0% +not just the sum of the pixels +but you're going to throw out + + align:start position:0% +but you're going to throw out + + + align:start position:0% +but you're going to throw out +colors that + + align:start position:0% +colors that + + + align:start position:0% +colors that +are + + align:start position:0% +are + + + align:start position:0% +are +in minority + + align:start position:0% + + + + align:start position:0% + +and that will get much better + + align:start position:0% + + + + align:start position:0% + +instructions in the assignment uh when + + align:start position:0% +instructions in the assignment uh when + + + align:start position:0% +instructions in the assignment uh when +you're taking the pictures make sure + + align:start position:0% +you're taking the pictures make sure + + + align:start position:0% +you're taking the pictures make sure +they are placed at equal distances + + align:start position:0% +they are placed at equal distances + + + align:start position:0% +they are placed at equal distances +and you know you hold the camera in + + align:start position:0% +and you know you hold the camera in + + + align:start position:0% +and you know you hold the camera in +parallel fashion + + align:start position:0% +parallel fashion + + + align:start position:0% +parallel fashion +make sure the scene it has vibrant + + align:start position:0% +make sure the scene it has vibrant + + + align:start position:0% +make sure the scene it has vibrant +colors + + align:start position:0% +colors + + + align:start position:0% +colors +so this color should be + + align:start position:0% + + + + align:start position:0% + +100 100 + + align:start position:0% +100 100 + + + align:start position:0% +100 100 +pixel region of that + + align:start position:0% +pixel region of that + + + align:start position:0% +pixel region of that +and just run your code to make sure + + align:start position:0% +and just run your code to make sure + + + align:start position:0% +and just run your code to make sure +everything is done + + align:start position:0% +everything is done + + + align:start position:0% +everything is done +and then you can go and take your own + + align:start position:0% +and then you can go and take your own + + + align:start position:0% +and then you can go and take your own +images so even before it again + + align:start position:0% +images so even before it again + + + align:start position:0% +images so even before it again +run your code on those + + align:start position:0% + + + + align:start position:0% + +because if you start with your own + + align:start position:0% +because if you start with your own + + + align:start position:0% +because if you start with your own +images + + align:start position:0% +images + + + align:start position:0% +images +and you're not getting the right results + + align:start position:0% +and you're not getting the right results + + + align:start position:0% +and you're not getting the right results +you don't know if the problem is your + + align:start position:0% +you don't know if the problem is your + + + align:start position:0% +you don't know if the problem is your +photos are with your phone + + align:start position:0% +photos are with your phone + + + align:start position:0% +photos are with your phone +and + + align:start position:0% +and + + + align:start position:0% +and +does photoshop allow you to + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +images shift + + align:start position:0% + + + + align:start position:0% + +but just because it's fine i have + + align:start position:0% +but just because it's fine i have + + + align:start position:0% +but just because it's fine i have +friends of course don't wait till the + + align:start position:0% +friends of course don't wait till the + + + align:start position:0% +friends of course don't wait till the +first day of whenever + + align:start position:0% +first day of whenever + + + align:start position:0% +first day of whenever +you + + align:start position:0% +you + + + align:start position:0% +you +start today because + + align:start position:0% +start today because + + + align:start position:0% +start today because +the the fun part of this lecture taking + + align:start position:0% +the the fun part of this lecture taking + + + align:start position:0% +the the fun part of this lecture taking +this image + + align:start position:0% +this image + + + align:start position:0% +this image +and creating scenarios where you can see + + align:start position:0% +and creating scenarios where you can see + + + align:start position:0% +and creating scenarios where you can see +through and you know they should go on + + align:start position:0% +through and you know they should go on + + + align:start position:0% +through and you know they should go on +the thicker page + + align:start position:0% +the thicker page + + + align:start position:0% +the thicker page +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +you know we will comment on each other's + + align:start position:0% +you know we will comment on each other's + + + align:start position:0% +you know we will comment on each other's +uh each of the score uh for the first + + align:start position:0% +uh each of the score uh for the first + + + align:start position:0% +uh each of the score uh for the first +assignment only five out of several + + align:start position:0% +assignment only five out of several + + + align:start position:0% +assignment only five out of several +dozen submissions + + align:start position:0% + + + + align:start position:0% + +so almost everybody got an a so you + + align:start position:0% +so almost everybody got an a so you + + + align:start position:0% +so almost everybody got an a so you +should feel good about yourself but + + align:start position:0% +should feel good about yourself but + + + align:start position:0% +should feel good about yourself but +somebody got a plus + + align:start position:0% + + + + align:start position:0% + +so yeah make sure it's on flickr and all + + align:start position:0% +so yeah make sure it's on flickr and all + + + align:start position:0% +so yeah make sure it's on flickr and all +those three places + + align:start position:0% +those three places + + + align:start position:0% +those three places +and feel free to send me uh email you + + align:start position:0% +and feel free to send me uh email you + + + align:start position:0% +and feel free to send me uh email you +can talk to + + align:start position:0% +can talk to + + + align:start position:0% +can talk to +professor oliveira or professor + + align:start position:0% +professor oliveira or professor + + + align:start position:0% +professor oliveira or professor +mukaigawa + + align:start position:0% +mukaigawa + + + align:start position:0% +mukaigawa +about any of this or also unkit + + align:start position:0% +about any of this or also unkit + + + align:start position:0% +about any of this or also unkit +and chemo is also here if you want to + + align:start position:0% +and chemo is also here if you want to + + + align:start position:0% +and chemo is also here if you want to +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +3d scanning and so on and use the forum + + align:start position:0% +3d scanning and so on and use the forum + + + align:start position:0% +3d scanning and so on and use the forum +on the stellar website + + align:start position:0% +on the stellar website + + + align:start position:0% +on the stellar website +and + + align:start position:0% +and + + + align:start position:0% +and +so on so today's lecture was + + align:start position:0% +so on so today's lecture was + + + align:start position:0% +so on so today's lecture was +very much focusing on the theory behind + + align:start position:0% +very much focusing on the theory behind + + + align:start position:0% +very much focusing on the theory behind +uh how we start thinking and then + + align:start position:0% +uh how we start thinking and then + + + align:start position:0% +uh how we start thinking and then +starting next week we'll be looking at + + align:start position:0% +starting next week we'll be looking at + + + align:start position:0% +starting next week we'll be looking at +very different applications and + + align:start position:0% +very different applications and + + + align:start position:0% +very different applications and +different tricks we use + + align:start position:0% +different tricks we use + + + align:start position:0% +different tricks we use +in optics + + align:start position:0% +in optics + + + align:start position:0% +in optics +so + + align:start position:0% +so + + + align:start position:0% +so +just go through the slide lap post today + + align:start position:0% +just go through the slide lap post today + + + align:start position:0% +just go through the slide lap post today +they are conceptual + + align:start position:0% +they are conceptual + + + align:start position:0% +they are conceptual +but it will take you some time to just + + align:start position:0% +but it will take you some time to just + + + align:start position:0% +but it will take you some time to just +grasp it + + align:start position:0% +grasp it + + + align:start position:0% +grasp it +and again as i said it might feel + + align:start position:0% +and again as i said it might feel + + + align:start position:0% +and again as i said it might feel +somewhat hard to think in a dual space + + align:start position:0% +somewhat hard to think in a dual space + + + align:start position:0% +somewhat hard to think in a dual space +of x and theta as opposed to just + + align:start position:0% +of x and theta as opposed to just + + + align:start position:0% +of x and theta as opposed to just +finding the rays directly + + align:start position:0% +finding the rays directly + + + align:start position:0% +finding the rays directly +but as you will see later especially in + + align:start position:0% +but as you will see later especially in + + + align:start position:0% +but as you will see later especially in +your projects and so on and this will + + align:start position:0% +your projects and so on and this will + + + align:start position:0% +your projects and so on and this will +greatly simplify + + align:start position:0% + + + + align:start position:0% + +this is going to simplify the way you + + align:start position:0% +this is going to simplify the way you + + + align:start position:0% +this is going to simplify the way you +think about your problems + + align:start position:0% +think about your problems + + + align:start position:0% +think about your problems +cool + + align:start position:0% +cool + + + align:start position:0% +cool +have a good weekend \ No newline at end of file diff --git a/u3Umk_2PVuw.txt b/u3Umk_2PVuw.txt new file mode 100644 index 0000000000000000000000000000000000000000..0b573493f2969fc479a4ca37fa96466cb26bd29c --- /dev/null +++ b/u3Umk_2PVuw.txt @@ -0,0 +1,7767 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencare at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so welcome to lean thinking + + align:start position:0% +ocw.mit.edu so welcome to lean thinking + + + align:start position:0% +ocw.mit.edu so welcome to lean thinking +part two uh we're essentially going to + + align:start position:0% +part two uh we're essentially going to + + + align:start position:0% +part two uh we're essentially going to +pick up where left off last time in + + align:start position:0% +pick up where left off last time in + + + align:start position:0% +pick up where left off last time in +discussing the uh the lean framework of + + align:start position:0% +discussing the uh the lean framework of + + + align:start position:0% +discussing the uh the lean framework of +thinking about value the value Stream + + align:start position:0% +thinking about value the value Stream + + + align:start position:0% +thinking about value the value Stream +flow pole and Perfection um hopefully + + align:start position:0% +flow pole and Perfection um hopefully + + + align:start position:0% +flow pole and Perfection um hopefully +the the video gave you some real active + + align:start position:0% +the the video gave you some real active + + + align:start position:0% +the the video gave you some real active +sort of visual representations of what + + align:start position:0% +sort of visual representations of what + + + align:start position:0% +sort of visual representations of what +some of these Concepts might might mean + + align:start position:0% +some of these Concepts might might mean + + + align:start position:0% +some of these Concepts might might mean +so let's talk about um flow we would + + align:start position:0% +so let's talk about um flow we would + + + align:start position:0% +so let's talk about um flow we would +like if we have a value stream this is a + + align:start position:0% +like if we have a value stream this is a + + + align:start position:0% +like if we have a value stream this is a +patient value stream we have people + + align:start position:0% +patient value stream we have people + + + align:start position:0% +patient value stream we have people +coming in and going through diagnostic + + align:start position:0% +coming in and going through diagnostic + + + align:start position:0% +coming in and going through diagnostic +procedures and hopefully leaving in + + align:start position:0% +procedures and hopefully leaving in + + + align:start position:0% +procedures and hopefully leaving in +better shape than they came in and we + + align:start position:0% +better shape than they came in and we + + + align:start position:0% +better shape than they came in and we +would like to create flow in this system + + align:start position:0% +would like to create flow in this system + + + align:start position:0% +would like to create flow in this system +we have to think about a bunch of things + + align:start position:0% +we have to think about a bunch of things + + + align:start position:0% +we have to think about a bunch of things +we we obviously want to focus on what is + + align:start position:0% +we we obviously want to focus on what is + + + align:start position:0% +we we obviously want to focus on what is +flowing again the value stream map is a + + align:start position:0% +flowing again the value stream map is a + + + align:start position:0% +flowing again the value stream map is a +is a map that looks at the at the + + align:start position:0% +is a map that looks at the at the + + + align:start position:0% +is a map that looks at the at the +product in this case the patient flowing + + align:start position:0% +product in this case the patient flowing + + + align:start position:0% +product in this case the patient flowing +through the uh process + + align:start position:0% +through the uh process + + + align:start position:0% +through the uh process +um we we don't want to be uh limited by + + align:start position:0% +um we we don't want to be uh limited by + + + align:start position:0% +um we we don't want to be uh limited by +organizational or people boundaries it's + + align:start position:0% +organizational or people boundaries it's + + + align:start position:0% +organizational or people boundaries it's +not a value stream map if it follows say + + align:start position:0% +not a value stream map if it follows say + + + align:start position:0% +not a value stream map if it follows say +an organizational work or an + + align:start position:0% +an organizational work or an + + + align:start position:0% +an organizational work or an +individual's work it's really about the + + align:start position:0% +individual's work it's really about the + + + align:start position:0% +individual's work it's really about the +about the product um in first order we + + align:start position:0% +about the product um in first order we + + + align:start position:0% +about the product um in first order we +want to make sure that there's the + + align:start position:0% +want to make sure that there's the + + + align:start position:0% +want to make sure that there's the +minimum amount of uh buffers in there + + align:start position:0% +minimum amount of uh buffers in there + + + align:start position:0% +minimum amount of uh buffers in there +inventory here's a waiting room full of + + align:start position:0% +inventory here's a waiting room full of + + + align:start position:0% +inventory here's a waiting room full of +people that's not flow right and that's + + align:start position:0% +people that's not flow right and that's + + + align:start position:0% +people that's not flow right and that's +it's interesting to me as a non-medical + + align:start position:0% +it's interesting to me as a non-medical + + + align:start position:0% +it's interesting to me as a non-medical +professional to just sort of observe uh + + align:start position:0% +professional to just sort of observe uh + + + align:start position:0% +professional to just sort of observe uh +things from uh from a lean perspective I + + align:start position:0% +things from uh from a lean perspective I + + + align:start position:0% +things from uh from a lean perspective I +have had both good and bad experiences + + align:start position:0% +have had both good and bad experiences + + + align:start position:0% +have had both good and bad experiences +as a patient or the parent of patients + + align:start position:0% +as a patient or the parent of patients + + + align:start position:0% +as a patient or the parent of patients +sometimes it's this you're sitting in + + align:start position:0% +sometimes it's this you're sitting in + + + align:start position:0% +sometimes it's this you're sitting in +the way waiting room for five or six + + align:start position:0% +the way waiting room for five or six + + + align:start position:0% +the way waiting room for five or six +hours um or and sometimes it + + align:start position:0% +hours um or and sometimes it + + + align:start position:0% +hours um or and sometimes it +isn't um I've had sort of astonishing + + align:start position:0% +isn't um I've had sort of astonishing + + + align:start position:0% +isn't um I've had sort of astonishing +experiences with well organized medical + + align:start position:0% +experiences with well organized medical + + + align:start position:0% +experiences with well organized medical +facilities where you know they hardly + + align:start position:0% +facilities where you know they hardly + + + align:start position:0% +facilities where you know they hardly +had literally once I didn't have time to + + align:start position:0% +had literally once I didn't have time to + + + align:start position:0% +had literally once I didn't have time to +sit down they gave me a little form to + + align:start position:0% +sit down they gave me a little form to + + + align:start position:0% +sit down they gave me a little form to +fill out and before I had finished + + align:start position:0% +fill out and before I had finished + + + align:start position:0% +fill out and before I had finished +filling out the form they were calling + + align:start position:0% +filling out the form they were calling + + + align:start position:0% +filling out the form they were calling +my name to see the doctor right it was + + align:start position:0% +my name to see the doctor right it was + + + align:start position:0% +my name to see the doctor right it was +it was a well organized system that had + + align:start position:0% +it was a well organized system that had + + + align:start position:0% +it was a well organized system that had +flow but bottlenecks are going to slow + + align:start position:0% +flow but bottlenecks are going to slow + + + align:start position:0% +flow but bottlenecks are going to slow +that down buffers essentially the same + + align:start position:0% +that down buffers essentially the same + + + align:start position:0% +that down buffers essentially the same +you know weight time in between steps + + align:start position:0% +you know weight time in between steps + + + align:start position:0% +you know weight time in between steps +sometimes that's necessary you have an + + align:start position:0% +sometimes that's necessary you have an + + + align:start position:0% +sometimes that's necessary you have an +expensive facility like a cat scanner + + align:start position:0% +expensive facility like a cat scanner + + + align:start position:0% +expensive facility like a cat scanner +you're not going to risk not using that + + align:start position:0% +you're not going to risk not using that + + + align:start position:0% +you're not going to risk not using that +facility so people are going to have to + + align:start position:0% +facility so people are going to have to + + + align:start position:0% +facility so people are going to have to +wait for it but to achieve flow you need + + align:start position:0% +wait for it but to achieve flow you need + + + align:start position:0% +wait for it but to achieve flow you need +to minimize that and one of the key + + align:start position:0% +to minimize that and one of the key + + + align:start position:0% +to minimize that and one of the key +things to think about is time it's an + + align:start position:0% +things to think about is time it's an + + + align:start position:0% +things to think about is time it's an +essential metric our discussion today is + + align:start position:0% +essential metric our discussion today is + + + align:start position:0% +essential metric our discussion today is +going to really be about how how do we + + align:start position:0% +going to really be about how how do we + + + align:start position:0% +going to really be about how how do we +measure and Define time um time is sort + + align:start position:0% +measure and Define time um time is sort + + + align:start position:0% +measure and Define time um time is sort +of an obvious thing but when when you + + align:start position:0% +of an obvious thing but when when you + + + align:start position:0% +of an obvious thing but when when you +start thinking about measuring and + + align:start position:0% +start thinking about measuring and + + + align:start position:0% +start thinking about measuring and +defining it it does get a little bit + + align:start position:0% +defining it it does get a little bit + + + align:start position:0% +defining it it does get a little bit +complicated you have to think about it + + align:start position:0% +complicated you have to think about it + + + align:start position:0% +complicated you have to think about it +carefully um and the key is really to + + align:start position:0% +carefully um and the key is really to + + + align:start position:0% +carefully um and the key is really to +understand the definition uh of how the + + align:start position:0% +understand the definition uh of how the + + + align:start position:0% +understand the definition uh of how the +time is measured um and one of the + + align:start position:0% +time is measured um and one of the + + + align:start position:0% +time is measured um and one of the +problems here is that the terminology + + align:start position:0% +problems here is that the terminology + + + align:start position:0% +problems here is that the terminology +there's some terminology here is not + + align:start position:0% +there's some terminology here is not + + + align:start position:0% +there's some terminology here is not +standardized so in different fields + + align:start position:0% +standardized so in different fields + + + align:start position:0% +standardized so in different fields +industrial engineers and supply chain + + align:start position:0% +industrial engineers and supply chain + + + align:start position:0% +industrial engineers and supply chain +people will talk about things using the + + align:start position:0% +people will talk about things using the + + + align:start position:0% +people will talk about things using the +same words they mean different things + + align:start position:0% +same words they mean different things + + + align:start position:0% +same words they mean different things +some sometimes the words are used in a + + align:start position:0% +some sometimes the words are used in a + + + align:start position:0% +some sometimes the words are used in a +way that isn't intuitive so rather than + + align:start position:0% +way that isn't intuitive so rather than + + + align:start position:0% +way that isn't intuitive so rather than +try to teach you the jargon of any + + align:start position:0% +try to teach you the jargon of any + + + align:start position:0% +try to teach you the jargon of any +particular field what we're going to ask + + align:start position:0% +particular field what we're going to ask + + + align:start position:0% +particular field what we're going to ask +you to do is think about time and + + align:start position:0% +you to do is think about time and + + + align:start position:0% +you to do is think about time and +understand and make sure you you + + align:start position:0% +understand and make sure you you + + + align:start position:0% +understand and make sure you you +understand and communicate your + + align:start position:0% +understand and communicate your + + + align:start position:0% +understand and communicate your +definitions of time and we'll actually + + align:start position:0% +definitions of time and we'll actually + + + align:start position:0% +definitions of time and we'll actually +have a little exercise about that so + + align:start position:0% +have a little exercise about that so + + + align:start position:0% +have a little exercise about that so +wait time that's relatively simple um if + + align:start position:0% +wait time that's relatively simple um if + + + align:start position:0% +wait time that's relatively simple um if +something is just sitting there um it is + + align:start position:0% +something is just sitting there um it is + + + align:start position:0% +something is just sitting there um it is +waiting so there's there is uh work in + + align:start position:0% +waiting so there's there is uh work in + + + align:start position:0% +waiting so there's there is uh work in +progress the work that you're trying to + + align:start position:0% +progress the work that you're trying to + + + align:start position:0% +progress the work that you're trying to +do is is not moving forward that's wait + + align:start position:0% +do is is not moving forward that's wait + + + align:start position:0% +do is is not moving forward that's wait +time that's also called Q time delay + + align:start position:0% +time that's also called Q time delay + + + align:start position:0% +time that's also called Q time delay +time again the terminology isn't + + align:start position:0% +time again the terminology isn't + + + align:start position:0% +time again the terminology isn't +particularly standard the concept is + + align:start position:0% +particularly standard the concept is + + + align:start position:0% +particularly standard the concept is +pretty easy to understand though + + align:start position:0% +pretty easy to understand though + + + align:start position:0% +pretty easy to understand though +processing time on the other hand is a + + align:start position:0% +processing time on the other hand is a + + + align:start position:0% +processing time on the other hand is a +little bit more complicated um so now + + align:start position:0% +little bit more complicated um so now + + + align:start position:0% +little bit more complicated um so now +something is happening to the work + + align:start position:0% +something is happening to the work + + + align:start position:0% +something is happening to the work +product uh some sort of resources are + + align:start position:0% +product uh some sort of resources are + + + align:start position:0% +product uh some sort of resources are +being consumed maybe a person is working + + align:start position:0% +being consumed maybe a person is working + + + align:start position:0% +being consumed maybe a person is working +on it maybe a machine is working on it + + align:start position:0% +on it maybe a machine is working on it + + + align:start position:0% +on it maybe a machine is working on it +and that could be value added or + + align:start position:0% +and that could be value added or + + + align:start position:0% +and that could be value added or +non-value added it could be an active or + + align:start position:0% +non-value added it could be an active or + + + align:start position:0% +non-value added it could be an active or +uh or relatively passive use there are + + align:start position:0% +uh or relatively passive use there are + + + align:start position:0% +uh or relatively passive use there are +multiple names for it touch time kind of + + align:start position:0% +multiple names for it touch time kind of + + + align:start position:0% +multiple names for it touch time kind of +gets to the to the to I I kind of like + + align:start position:0% +gets to the to the to I I kind of like + + + align:start position:0% +gets to the to the to I I kind of like +touch time because it's intuitive means + + align:start position:0% +touch time because it's intuitive means + + + align:start position:0% +touch time because it's intuitive means +and in in for example engineering or + + align:start position:0% +and in in for example engineering or + + + align:start position:0% +and in in for example engineering or +Health Care work someone is working on + + align:start position:0% +Health Care work someone is working on + + + align:start position:0% +Health Care work someone is working on +it right it's that's those both of those + + align:start position:0% +it right it's that's those both of those + + + align:start position:0% +it right it's that's those both of those +fields are very people intensive if + + align:start position:0% +fields are very people intensive if + + + align:start position:0% +fields are very people intensive if +somebody is working with the patient or + + align:start position:0% +somebody is working with the patient or + + + align:start position:0% +somebody is working with the patient or +working with the diagnosis or working + + align:start position:0% +working with the diagnosis or working + + + align:start position:0% +working with the diagnosis or working +with the engineering drawing that's + + align:start position:0% +with the engineering drawing that's + + + align:start position:0% +with the engineering drawing that's +touch time it's also sometimes called in + + align:start position:0% +touch time it's also sometimes called in + + + align:start position:0% +touch time it's also sometimes called in +process time or response time in the + + align:start position:0% +process time or response time in the + + + align:start position:0% +process time or response time in the +sense of how quickly can the people + + align:start position:0% +sense of how quickly can the people + + + align:start position:0% +sense of how quickly can the people +respond to a demand that they get + + align:start position:0% +respond to a demand that they get + + + align:start position:0% +respond to a demand that they get +something + + align:start position:0% +something + + + align:start position:0% +something +done and these things tend to pile up + + align:start position:0% +done and these things tend to pile up + + + align:start position:0% +done and these things tend to pile up +in ways that it kind of Illustrated here + + align:start position:0% +in ways that it kind of Illustrated here + + + align:start position:0% +in ways that it kind of Illustrated here +in a simple case you know if you have + + align:start position:0% +in a simple case you know if you have + + + align:start position:0% +in a simple case you know if you have +some work you need to get done well + + align:start position:0% +some work you need to get done well + + + align:start position:0% +some work you need to get done well +first it + + align:start position:0% +first it + + + align:start position:0% +first it +waits question how would you categorize + + align:start position:0% +waits question how would you categorize + + + align:start position:0% +waits question how would you categorize +a for example there was an oven on one + + align:start position:0% +a for example there was an oven on one + + + align:start position:0% +a for example there was an oven on one +of those shoes yeah and he would heat + + align:start position:0% +of those shoes yeah and he would heat + + + align:start position:0% +of those shoes yeah and he would heat +the thing up but then he would open the + + align:start position:0% +the thing up but then he would open the + + + align:start position:0% +the thing up but then he would open the +open the OV and let it sit not touch it + + align:start position:0% +open the OV and let it sit not touch it + + + align:start position:0% +open the OV and let it sit not touch it +because it + + align:start position:0% +because it + + + align:start position:0% +because it +was that's right that's classic right + + align:start position:0% +was that's right that's classic right + + + align:start position:0% +was that's right that's classic right +okay so is that weight time because it's + + align:start position:0% +okay so is that weight time because it's + + + align:start position:0% +okay so is that weight time because it's +cooling off well but it's occupying the + + align:start position:0% +cooling off well but it's occupying the + + + align:start position:0% +cooling off well but it's occupying the +oven it's not touch time the guy is not + + align:start position:0% +oven it's not touch time the guy is not + + + align:start position:0% +oven it's not touch time the guy is not +working on it he can go do something + + align:start position:0% +working on it he can go do something + + + align:start position:0% +working on it he can go do something +else right but the equipment is used is + + align:start position:0% +else right but the equipment is used is + + + align:start position:0% +else right but the equipment is used is +used so that's that's classic and I I + + align:start position:0% +used so that's that's classic and I I + + + align:start position:0% +used so that's that's classic and I I +don't have an easy answer for you it + + align:start position:0% +don't have an easy answer for you it + + + align:start position:0% +don't have an easy answer for you it +depends on what you're measuring if + + align:start position:0% +depends on what you're measuring if + + + align:start position:0% +depends on what you're measuring if +you're measuring the equipment you know + + align:start position:0% +you're measuring the equipment you know + + + align:start position:0% +you're measuring the equipment you know +how many ovens do we need you better you + + align:start position:0% +how many ovens do we need you better you + + + align:start position:0% +how many ovens do we need you better you +know account for that cooling because + + align:start position:0% +know account for that cooling because + + + align:start position:0% +know account for that cooling because +they probably don't want to yank it out + + align:start position:0% +they probably don't want to yank it out + + + align:start position:0% +they probably don't want to yank it out +it'll cool too fast right um so you know + + align:start position:0% +it'll cool too fast right um so you know + + + align:start position:0% +it'll cool too fast right um so you know +if you're concerned as the oven you got + + align:start position:0% +if you're concerned as the oven you got + + + align:start position:0% +if you're concerned as the oven you got +to count that if you're concerned as the + + align:start position:0% +to count that if you're concerned as the + + + align:start position:0% +to count that if you're concerned as the +worker that part doesn't count your + + align:start position:0% +worker that part doesn't count your + + + align:start position:0% +worker that part doesn't count your +concern is the + + align:start position:0% +concern is the + + + align:start position:0% +concern is the +shoe it's in process in some way right + + align:start position:0% +shoe it's in process in some way right + + + align:start position:0% +shoe it's in process in some way right +it's cooling off that you can't make + + align:start position:0% +it's cooling off that you can't make + + + align:start position:0% +it's cooling off that you can't make +that go fast you can't say that's weight + + align:start position:0% +that go fast you can't say that's weight + + + align:start position:0% +that go fast you can't say that's weight +time because you can't make that go + + align:start position:0% +time because you can't make that go + + + align:start position:0% +time because you can't make that go +faster right another classic one is + + align:start position:0% +faster right another classic one is + + + align:start position:0% +faster right another classic one is +painting you can't make paint dry faster + + align:start position:0% +painting you can't make paint dry faster + + + align:start position:0% +painting you can't make paint dry faster +well you can you can blast hot air on it + + align:start position:0% +well you can you can blast hot air on it + + + align:start position:0% +well you can you can blast hot air on it +but that may or may not be a good thing + + align:start position:0% +but that may or may not be a good thing + + + align:start position:0% +but that may or may not be a good thing +right so right and that's exactly what + + align:start position:0% +right so right and that's exactly what + + + align:start position:0% +right so right and that's exactly what +I'm trying to get across here is that + + align:start position:0% +I'm trying to get across here is that + + + align:start position:0% +I'm trying to get across here is that +the time has a lot of a lot of sort of + + align:start position:0% +the time has a lot of a lot of sort of + + + align:start position:0% +the time has a lot of a lot of sort of +unexpected complexity when you're + + align:start position:0% +unexpected complexity when you're + + + align:start position:0% +unexpected complexity when you're +looking at these things and you have to + + align:start position:0% +looking at these things and you have to + + + align:start position:0% +looking at these things and you have to +you have to think pretty straight about + + align:start position:0% +you have to think pretty straight about + + + align:start position:0% +you have to think pretty straight about +it so you could be waiting you could be + + align:start position:0% +it so you could be waiting you could be + + + align:start position:0% +it so you could be waiting you could be +doing value added work you could be nonv + + align:start position:0% +doing value added work you could be nonv + + + align:start position:0% +doing value added work you could be nonv +value added but still in processing + + align:start position:0% +value added but still in processing + + + align:start position:0% +value added but still in processing +right we we stuck the glue on now we're + + align:start position:0% +right we we stuck the glue on now we're + + + align:start position:0% +right we we stuck the glue on now we're +cooling off we're still using the + + align:start position:0% +cooling off we're still using the + + + align:start position:0% +cooling off we're still using the +oven we can't leave the oven but it's + + align:start position:0% +oven we can't leave the oven but it's + + + align:start position:0% +oven we can't leave the oven but it's +not really value added maybe we could do + + align:start position:0% +not really value added maybe we could do + + + align:start position:0% +not really value added maybe we could do +that in a different way maybe it's + + align:start position:0% +that in a different way maybe it's + + + align:start position:0% +that in a different way maybe it's +necessary nonv value added you know + + align:start position:0% +necessary nonv value added you know + + + align:start position:0% +necessary nonv value added you know +maybe we'll call call that yellow at + + align:start position:0% +maybe we'll call call that yellow at + + + align:start position:0% +maybe we'll call call that yellow at +some point the processing ends and we go + + align:start position:0% +some point the processing ends and we go + + + align:start position:0% +some point the processing ends and we go +back into inventory and we're waiting + + align:start position:0% +back into inventory and we're waiting + + + align:start position:0% +back into inventory and we're waiting +again and sort of Imagine That cycle + + align:start position:0% +again and sort of Imagine That cycle + + + align:start position:0% +again and sort of Imagine That cycle +repeated lots of times to finish our + + align:start position:0% +repeated lots of times to finish our + + + align:start position:0% +repeated lots of times to finish our +overall process so and cycle time is our + + align:start position:0% +overall process so and cycle time is our + + + align:start position:0% +overall process so and cycle time is our +overall all time um there isn't a whole + + align:start position:0% +overall all time um there isn't a whole + + + align:start position:0% +overall all time um there isn't a whole +lot of uh confusion about cycle time + + align:start position:0% +lot of uh confusion about cycle time + + + align:start position:0% +lot of uh confusion about cycle time +means overall time weight weight plus + + align:start position:0% +means overall time weight weight plus + + + align:start position:0% +means overall time weight weight plus +processing there's some other names for + + align:start position:0% +processing there's some other names for + + + align:start position:0% +processing there's some other names for +it the thing you have to really watch + + align:start position:0% +it the thing you have to really watch + + + align:start position:0% +it the thing you have to really watch +out for cycle time is cycle of what it + + align:start position:0% +out for cycle time is cycle of what it + + + align:start position:0% +out for cycle time is cycle of what it +could be the cycle of a machine kachunk + + align:start position:0% +could be the cycle of a machine kachunk + + + align:start position:0% +could be the cycle of a machine kachunk +kachunk kachunk right that's seconds um + + align:start position:0% +kachunk kachunk right that's seconds um + + + align:start position:0% +kachunk kachunk right that's seconds um +it could be cycle of the overall shoe + + align:start position:0% +it could be cycle of the overall shoe + + + align:start position:0% +it could be cycle of the overall shoe +manufacturing process which and New + + align:start position:0% +manufacturing process which and New + + + align:start position:0% +manufacturing process which and New +Balance was an amazingly short three + + align:start position:0% +Balance was an amazingly short three + + + align:start position:0% +Balance was an amazingly short three +days uh but in you know Aeronautical + + align:start position:0% +days uh but in you know Aeronautical + + + align:start position:0% +days uh but in you know Aeronautical +Engineering cycle time of an aircraft + + align:start position:0% +Engineering cycle time of an aircraft + + + align:start position:0% +Engineering cycle time of an aircraft +life cycle 20 years you know cycle time + + align:start position:0% +life cycle 20 years you know cycle time + + + align:start position:0% +life cycle 20 years you know cycle time +can mean a lot of different things you + + align:start position:0% +can mean a lot of different things you + + + align:start position:0% +can mean a lot of different things you +got to just Define your your boundaries + + align:start position:0% +got to just Define your your boundaries + + + align:start position:0% +got to just Define your your boundaries +uh very carefully when you're talking + + align:start position:0% +uh very carefully when you're talking + + + align:start position:0% +uh very carefully when you're talking +about um cycle time so now we have a + + align:start position:0% +about um cycle time so now we have a + + + align:start position:0% +about um cycle time so now we have a +little exercise we're going to ask you + + align:start position:0% +little exercise we're going to ask you + + + align:start position:0% +little exercise we're going to ask you +to tackle some of these complexities I + + align:start position:0% +to tackle some of these complexities I + + + align:start position:0% +to tackle some of these complexities I +hope everybody held on to this sheet um + + align:start position:0% +hope everybody held on to this sheet um + + + align:start position:0% +hope everybody held on to this sheet um +you were using this before hopefully you + + align:start position:0% +you were using this before hopefully you + + + align:start position:0% +you were using this before hopefully you +didn't um we call it 5sing out of + + align:start position:0% +didn't um we call it 5sing out of + + + align:start position:0% +didn't um we call it 5sing out of +existence you know you clean up + + align:start position:0% +existence you know you clean up + + + align:start position:0% +existence you know you clean up +something you really need and then it's + + align:start position:0% +something you really need and then it's + + + align:start position:0% +something you really need and then it's +gone hope that didn't happen + + align:start position:0% +gone hope that didn't happen + + + align:start position:0% +gone hope that didn't happen +um because now we're going to look at + + align:start position:0% +um because now we're going to look at + + + align:start position:0% +um because now we're going to look at +the at the times and we're going to do a + + align:start position:0% +the at the times and we're going to do a + + + align:start position:0% +the at the times and we're going to do a +little exercise we're going to add up + + align:start position:0% +little exercise we're going to add up + + + align:start position:0% +little exercise we're going to add up +the overall cycle time of an order from + + align:start position:0% +the overall cycle time of an order from + + + align:start position:0% +the overall cycle time of an order from +the time the customer walks up to the + + align:start position:0% +the time the customer walks up to the + + + align:start position:0% +the time the customer walks up to the +time they get their hot dog the tricky + + align:start position:0% +time they get their hot dog the tricky + + + align:start position:0% +time they get their hot dog the tricky +thing is these times are not necessarily + + align:start position:0% +thing is these times are not necessarily + + + align:start position:0% +thing is these times are not necessarily +in the right units make sure everything + + align:start position:0% +in the right units make sure everything + + + align:start position:0% +in the right units make sure everything +is converted to time per order right is + + align:start position:0% +is converted to time per order right is + + + align:start position:0% +is converted to time per order right is +it time for hot dog subtle right what's + + align:start position:0% +it time for hot dog subtle right what's + + + align:start position:0% +it time for hot dog subtle right what's +the average order does anybody + + align:start position:0% +the average order does anybody + + + align:start position:0% +the average order does anybody +remember two hot dogs right so um and we + + align:start position:0% +remember two hot dogs right so um and we + + + align:start position:0% +remember two hot dogs right so um and we +got to worry about rework there's some + + align:start position:0% +got to worry about rework there's some + + + align:start position:0% +got to worry about rework there's some +percentage chance we're looking at the + + align:start position:0% +percentage chance we're looking at the + + + align:start position:0% +percentage chance we're looking at the +average there's some percentage chance + + align:start position:0% +average there's some percentage chance + + + align:start position:0% +average there's some percentage chance +that things are going to have to be done + + align:start position:0% +that things are going to have to be done + + + align:start position:0% +that things are going to have to be done +over so this this actually gets pretty + + align:start position:0% +over so this this actually gets pretty + + + align:start position:0% +over so this this actually gets pretty +well at some at how tricky this can + + align:start position:0% +well at some at how tricky this can + + + align:start position:0% +well at some at how tricky this can +sometimes be all right so try to + + align:start position:0% +sometimes be all right so try to + + + align:start position:0% +sometimes be all right so try to +normalize the times sum them up and use + + align:start position:0% +normalize the times sum them up and use + + + align:start position:0% +normalize the times sum them up and use +the sheet this is actually a group + + align:start position:0% +the sheet this is actually a group + + + align:start position:0% +the sheet this is actually a group +exercise if you guys want to divide and + + align:start position:0% +exercise if you guys want to divide and + + + align:start position:0% +exercise if you guys want to divide and +conquer or if you just want to see you + + align:start position:0% +conquer or if you just want to see you + + + align:start position:0% +conquer or if you just want to see you +know a see what people get whatever um + + align:start position:0% +know a see what people get whatever um + + + align:start position:0% +know a see what people get whatever um +whatever strategy you want to take to uh + + align:start position:0% +whatever strategy you want to take to uh + + + align:start position:0% +whatever strategy you want to take to uh +to uh to puzzle this out is fine but you + + align:start position:0% +to uh to puzzle this out is fine but you + + + align:start position:0% +to uh to puzzle this out is fine but you +only have um little under 10 minutes why + + align:start position:0% +only have um little under 10 minutes why + + + align:start position:0% +only have um little under 10 minutes why +don't we give it till like three after + + align:start position:0% +don't we give it till like three after + + + align:start position:0% +don't we give it till like three after +to do this + + align:start position:0% + + + + align:start position:0% + +exercise I see what you're saying so it + + align:start position:0% +exercise I see what you're saying so it + + + align:start position:0% +exercise I see what you're saying so it +does it shouldn't take 20 seconds to put + + align:start position:0% +does it shouldn't take 20 seconds to put + + + align:start position:0% +does it shouldn't take 20 seconds to put +a hot dog in a bun yeah so 20 seconds + + align:start position:0% +a hot dog in a bun yeah so 20 seconds + + + align:start position:0% +a hot dog in a bun yeah so 20 seconds +with it in the bun and then get the + + align:start position:0% +with it in the bun and then get the + + + align:start position:0% +with it in the bun and then get the +about 10 seconds putting about 10 + + align:start position:0% +about 10 seconds putting about 10 + + + align:start position:0% +about 10 seconds putting about 10 +seconds putting exactly that's how I + + align:start position:0% +seconds putting exactly that's how I + + + align:start position:0% +seconds putting exactly that's how I +interpret all righty what do you got + + align:start position:0% +interpret all righty what do you got + + + align:start position:0% +interpret all righty what do you got +one of the one of the fun things about + + align:start position:0% +one of the one of the fun things about + + + align:start position:0% +one of the one of the fun things about +uh about this class is is is our uh sort + + align:start position:0% +uh about this class is is is our uh sort + + + align:start position:0% +uh about this class is is is our uh sort +of unintentional e u experimenting and + + align:start position:0% +of unintentional e u experimenting and + + + align:start position:0% +of unintentional e u experimenting and +work Styles is some people were like + + align:start position:0% +work Styles is some people were like + + + align:start position:0% +work Styles is some people were like +just doing away you know other people + + align:start position:0% +just doing away you know other people + + + align:start position:0% +just doing away you know other people +were talking waving their arms and stuff + + align:start position:0% +were talking waving their arms and stuff + + + align:start position:0% +were talking waving their arms and stuff +it was interesting let's see if uh let's + + align:start position:0% +it was interesting let's see if uh let's + + + align:start position:0% +it was interesting let's see if uh let's +see what what uh this process yielded + + align:start position:0% +see what what uh this process yielded + + + align:start position:0% +see what what uh this process yielded +I'm numbering you guys M1 through three + + align:start position:0% +I'm numbering you guys M1 through three + + + align:start position:0% +I'm numbering you guys M1 through three +and E1 and two um so first uh medical + + align:start position:0% +and E1 and two um so first uh medical + + + align:start position:0% +and E1 and two um so first uh medical +option table what do you + + align:start position:0% +option table what do you + + + align:start position:0% +option table what do you +got + + align:start position:0% +got + + + align:start position:0% +got +449 okay interesting + + align:start position:0% +449 okay interesting + + + align:start position:0% +449 okay interesting +m29 + + align:start position:0% + + + + align:start position:0% + +393 39 390 + + align:start position:0% + + + + align:start position:0% + +okay what do you guys got different + + align:start position:0% +okay what do you guys got different + + + align:start position:0% +okay what do you guys got different +things you have different things well + + align:start position:0% +things you have different things well + + + align:start position:0% +things you have different things well +give give me a sample see this is the + + align:start position:0% +give give me a sample see this is the + + + align:start position:0% +give give me a sample see this is the +table that didn't talk right so they've + + align:start position:0% +table that didn't talk right so they've + + + align:start position:0% +table that didn't talk right so they've +got yeah we have around 300 around 300 + + align:start position:0% +got yeah we have around 300 around 300 + + + align:start position:0% +got yeah we have around 300 around 300 +okay plus or + + align:start position:0% +okay plus or + + + align:start position:0% +okay plus or +minus all right and + + align:start position:0% +minus all right and + + + align:start position:0% +minus all right and +E2 + + align:start position:0% +E2 + + + align:start position:0% +E2 +432 okay there we + + align:start position:0% +432 okay there we + + + align:start position:0% +432 okay there we +go there we + + align:start position:0% +go there we + + + align:start position:0% +go there we +go + + align:start position:0% +go + + + align:start position:0% +go +um so we didn't exactly agree we're + + align:start position:0% +um so we didn't exactly agree we're + + + align:start position:0% +um so we didn't exactly agree we're +going to give you guys sort of an answer + + align:start position:0% +going to give you guys sort of an answer + + + align:start position:0% +going to give you guys sort of an answer +sheet later so you can like figure out + + align:start position:0% +sheet later so you can like figure out + + + align:start position:0% +sheet later so you can like figure out +uh but + + align:start position:0% +uh but + + + align:start position:0% +uh but +sort of illustrates the issue of the + + align:start position:0% +sort of illustrates the issue of the + + + align:start position:0% +sort of illustrates the issue of the +squirm of this you know it's a very + + align:start position:0% +squirm of this you know it's a very + + + align:start position:0% +squirm of this you know it's a very +simple + + align:start position:0% +simple + + + align:start position:0% +simple +process the times you were gave you the + + align:start position:0% +process the times you were gave you the + + + align:start position:0% +process the times you were gave you the +times right but how do you interpret + + align:start position:0% +times right but how do you interpret + + + align:start position:0% +times right but how do you interpret +them exactly how do you do the rework + + align:start position:0% +them exactly how do you do the rework + + + align:start position:0% +them exactly how do you do the rework +you average that in probably the most + + align:start position:0% +you average that in probably the most + + + align:start position:0% +you average that in probably the most +reasonable thing to do would be to add + + align:start position:0% +reasonable thing to do would be to add + + + align:start position:0% +reasonable thing to do would be to add +10% to all of the things that might have + + align:start position:0% +10% to all of the things that might have + + + align:start position:0% +10% to all of the things that might have +to be done over right but there's + + align:start position:0% +to be done over right but there's + + + align:start position:0% +to be done over right but there's +actually a couple of do over Loops so + + align:start position:0% +actually a couple of do over Loops so + + + align:start position:0% +actually a couple of do over Loops so +you add 20% to that one I you know I'm + + align:start position:0% +you add 20% to that one I you know I'm + + + align:start position:0% +you add 20% to that one I you know I'm +not sure right you could interpret that + + align:start position:0% +not sure right you could interpret that + + + align:start position:0% +not sure right you could interpret that +a couple different ways more more + + align:start position:0% +a couple different ways more more + + + align:start position:0% +a couple different ways more more +importantly how do you or more + + align:start position:0% +importantly how do you or more + + + align:start position:0% +importantly how do you or more +significantly it has a bigger impact on + + align:start position:0% +significantly it has a bigger impact on + + + align:start position:0% +significantly it has a bigger impact on +the numbers what do you do with that the + + align:start position:0% +the numbers what do you do with that the + + + align:start position:0% +the numbers what do you do with that the +stuff that's kind of off the main + + align:start position:0% +stuff that's kind of off the main + + + align:start position:0% +stuff that's kind of off the main +process Loop there the cleanup and the + + align:start position:0% +process Loop there the cleanup and the + + + align:start position:0% +process Loop there the cleanup and the +you know do you average that and put it + + align:start position:0% +you know do you average that and put it + + + align:start position:0% +you know do you average that and put it +in as a sort of tax against the each hot + + align:start position:0% +in as a sort of tax against the each hot + + + align:start position:0% +in as a sort of tax against the each hot +dog order or do you say no they'll do + + align:start position:0% +dog order or do you say no they'll do + + + align:start position:0% +dog order or do you say no they'll do +that when it's quiet it shouldn't count + + align:start position:0% +that when it's quiet it shouldn't count + + + align:start position:0% +that when it's quiet it shouldn't count +right and that's probably the difference + + align:start position:0% +right and that's probably the difference + + + align:start position:0% +right and that's probably the difference +between the people that were up above + + align:start position:0% +between the people that were up above + + + align:start position:0% +between the people that were up above +400 and the people down around 300 do + + align:start position:0% +400 and the people down around 300 do + + + align:start position:0% +400 and the people down around 300 do +that does that make sense that I hope + + align:start position:0% +that does that make sense that I hope + + + align:start position:0% +that does that make sense that I hope +the 300 people we're leaving that out + + align:start position:0% +the 300 people we're leaving that out + + + align:start position:0% +the 300 people we're leaving that out +because otherwise it's hard to get a + + align:start position:0% +because otherwise it's hard to get a + + + align:start position:0% +because otherwise it's hard to get a +number that + + align:start position:0% +number that + + + align:start position:0% +number that +small um while as this is um pretty much + + align:start position:0% +small um while as this is um pretty much + + + align:start position:0% +small um while as this is um pretty much +that that's that's a not sure that's + + align:start position:0% +that that's that's a not sure that's + + + align:start position:0% +that that's that's a not sure that's +somehow one second higher than than the + + align:start position:0% +somehow one second higher than than the + + + align:start position:0% +somehow one second higher than than the +number you get if you add 10% to + + align:start position:0% +number you get if you add 10% to + + + align:start position:0% +number you get if you add 10% to +everything and tax with the with the + + align:start position:0% +everything and tax with the with the + + + align:start position:0% +everything and tax with the with the +cleanup so that's that's real close to + + align:start position:0% +cleanup so that's that's real close to + + + align:start position:0% +cleanup so that's that's real close to +that number so there's different ways to + + align:start position:0% +that number so there's different ways to + + + align:start position:0% +that number so there's different ways to +do it and and they're all legitimate but + + align:start position:0% +do it and and they're all legitimate but + + + align:start position:0% +do it and and they're all legitimate but +it gives you a feel for how these things + + align:start position:0% +it gives you a feel for how these things + + + align:start position:0% +it gives you a feel for how these things +this is not an exact science right and + + align:start position:0% +this is not an exact science right and + + + align:start position:0% +this is not an exact science right and +again if we wanted to get more exact we + + align:start position:0% +again if we wanted to get more exact we + + + align:start position:0% +again if we wanted to get more exact we +would have to go to the GMO we might + + align:start position:0% +would have to go to the GMO we might + + + align:start position:0% +would have to go to the GMO we might +have to stand there with a stopwatch and + + align:start position:0% +have to stand there with a stopwatch and + + + align:start position:0% +have to stand there with a stopwatch and +watch the customers come and go and see + + align:start position:0% +watch the customers come and go and see + + + align:start position:0% +watch the customers come and go and see +what actually does happen right do you + + align:start position:0% +what actually does happen right do you + + + align:start position:0% +what actually does happen right do you +know for example the cleanup issue do + + align:start position:0% +know for example the cleanup issue do + + + align:start position:0% +know for example the cleanup issue do +they really have time to do it on the + + align:start position:0% +they really have time to do it on the + + + align:start position:0% +they really have time to do it on the +side or do they have to actually make + + align:start position:0% +side or do they have to actually make + + + align:start position:0% +side or do they have to actually make +customers wait while they do that you + + align:start position:0% +customers wait while they do that you + + + align:start position:0% +customers wait while they do that you +don't know until you go look so so again + + align:start position:0% +don't know until you go look so so again + + + align:start position:0% +don't know until you go look so so again +an illustration in in how this can be a + + align:start position:0% +an illustration in in how this can be a + + + align:start position:0% +an illustration in in how this can be a +a little tricky and we're going to go + + align:start position:0% +a little tricky and we're going to go + + + align:start position:0% +a little tricky and we're going to go +even deeper on this later this afternoon + + align:start position:0% +even deeper on this later this afternoon + + + align:start position:0% +even deeper on this later this afternoon +but for now that exercise is done + + align:start position:0% +but for now that exercise is done + + + align:start position:0% +but for now that exercise is done +um just a explanation of something we've + + align:start position:0% +um just a explanation of something we've + + + align:start position:0% +um just a explanation of something we've +had kind of across the bottom as an icon + + align:start position:0% +had kind of across the bottom as an icon + + + align:start position:0% +had kind of across the bottom as an icon +for a while um these things are called + + align:start position:0% +for a while um these things are called + + + align:start position:0% +for a while um these things are called +time value charts they're they're useful + + align:start position:0% +time value charts they're they're useful + + + align:start position:0% +time value charts they're they're useful +if you want to make broad points about + + align:start position:0% +if you want to make broad points about + + + align:start position:0% +if you want to make broad points about +the use of time um this is a uh typical + + align:start position:0% +the use of time um this is a uh typical + + + align:start position:0% +the use of time um this is a uh typical +example in a lot of ways here's a + + align:start position:0% +example in a lot of ways here's a + + + align:start position:0% +example in a lot of ways here's a +process that takes a while um apparently + + align:start position:0% +process that takes a while um apparently + + + align:start position:0% +process that takes a while um apparently +there are two spans of four days of + + align:start position:0% +there are two spans of four days of + + + align:start position:0% +there are two spans of four days of +solid work uh in this process as well as + + align:start position:0% +solid work uh in this process as well as + + + align:start position:0% +solid work uh in this process as well as +a lot of weight time and a lot of nonv + + align:start position:0% +a lot of weight time and a lot of nonv + + + align:start position:0% +a lot of weight time and a lot of nonv +value added working time um one of the + + align:start position:0% +value added working time um one of the + + + align:start position:0% +value added working time um one of the +key things that this kind of chart will + + align:start position:0% +key things that this kind of chart will + + + align:start position:0% +key things that this kind of chart will +tell you about almost any process it's + + align:start position:0% +tell you about almost any process it's + + + align:start position:0% +tell you about almost any process it's +very bizarre if you come up with a + + align:start position:0% +very bizarre if you come up with a + + + align:start position:0% +very bizarre if you come up with a +process that isn't this way um is that + + align:start position:0% +process that isn't this way um is that + + + align:start position:0% +process that isn't this way um is that +um uh the Big Time Savings are in the + + align:start position:0% +um uh the Big Time Savings are in the + + + align:start position:0% +um uh the Big Time Savings are in the +weight times and the non-v value added + + align:start position:0% +weight times and the non-v value added + + + align:start position:0% +weight times and the non-v value added +times and this is one of those key you + + align:start position:0% +times and this is one of those key you + + + align:start position:0% +times and this is one of those key you +know people were talking about the issue + + align:start position:0% +know people were talking about the issue + + + align:start position:0% +know people were talking about the issue +of you know standardizing work and and + + align:start position:0% +of you know standardizing work and and + + + align:start position:0% +of you know standardizing work and and +limiting + + align:start position:0% +limiting + + + align:start position:0% +limiting +creativity what I always tell the + + align:start position:0% +creativity what I always tell the + + + align:start position:0% +creativity what I always tell the +engineers uh is no we this is this is + + align:start position:0% +engineers uh is no we this is this is + + + align:start position:0% +engineers uh is no we this is this is +you doing your work we don't we almost + + align:start position:0% +you doing your work we don't we almost + + + align:start position:0% +you doing your work we don't we almost +don't care how you do it because it's a + + align:start position:0% +don't care how you do it because it's a + + + align:start position:0% +don't care how you do it because it's a +tiny percentage of the time right to + + align:start position:0% +tiny percentage of the time right to + + + align:start position:0% +tiny percentage of the time right to +keep the customers happy we got to take + + align:start position:0% +keep the customers happy we got to take + + + align:start position:0% +keep the customers happy we got to take +this out we got to take this out and + + align:start position:0% +this out we got to take this out and + + + align:start position:0% +this out we got to take this out and +that's what we're going to worry + + align:start position:0% +that's what we're going to worry + + + align:start position:0% +that's what we're going to worry +about um and in a way the same goes with + + align:start position:0% +about um and in a way the same goes with + + + align:start position:0% +about um and in a way the same goes with +with Medical Care uh a lot of + + align:start position:0% +with Medical Care uh a lot of + + + align:start position:0% +with Medical Care uh a lot of +the um customer dissatisfaction comes + + align:start position:0% +the um customer dissatisfaction comes + + + align:start position:0% +the um customer dissatisfaction comes +from this kind of + + align:start position:0% +from this kind of + + + align:start position:0% +from this kind of +stuff right if um you know my son gets + + align:start position:0% +stuff right if um you know my son gets + + + align:start position:0% +stuff right if um you know my son gets +injured I take him to the hospital I was + + align:start position:0% +injured I take him to the hospital I was + + + align:start position:0% +injured I take him to the hospital I was +absolutely delighted with the 45 seconds + + align:start position:0% +absolutely delighted with the 45 seconds + + + align:start position:0% +absolutely delighted with the 45 seconds +of care that he received in our 9h hour + + align:start position:0% +of care that he received in our 9h hour + + + align:start position:0% +of care that he received in our 9h hour +visit + + align:start position:0% +visit + + + align:start position:0% +visit +so I was not going to tell the old male + + align:start position:0% +so I was not going to tell the old male + + + align:start position:0% +so I was not going to tell the old male +nurse who was really good at stitches + + align:start position:0% +nurse who was really good at stitches + + + align:start position:0% +nurse who was really good at stitches +how to do his job I was delighted with + + align:start position:0% +how to do his job I was delighted with + + + align:start position:0% +how to do his job I was delighted with +his job but there was a bunch of other + + align:start position:0% +his job but there was a bunch of other + + + align:start position:0% +his job but there was a bunch of other +processes involved in that particular + + align:start position:0% +processes involved in that particular + + + align:start position:0% +processes involved in that particular +experience that could have that could + + align:start position:0% +experience that could have that could + + + align:start position:0% +experience that could have that could +have used Improvement which gets to the + + align:start position:0% +have used Improvement which gets to the + + + align:start position:0% +have used Improvement which gets to the +issue of pulling value I was the + + align:start position:0% +issue of pulling value I was the + + + align:start position:0% +issue of pulling value I was the +customer there I didn't really perceive + + align:start position:0% +customer there I didn't really perceive + + + align:start position:0% +customer there I didn't really perceive +value pull in that experience all I've + + align:start position:0% +value pull in that experience all I've + + + align:start position:0% +value pull in that experience all I've +had some where where I did so what does + + align:start position:0% +had some where where I did so what does + + + align:start position:0% +had some where where I did so what does +this mean this is a kind of a difficult + + align:start position:0% +this mean this is a kind of a difficult + + + align:start position:0% +this mean this is a kind of a difficult +concept and it it exists on a couple of + + align:start position:0% +concept and it it exists on a couple of + + + align:start position:0% +concept and it it exists on a couple of +scales sometimes the easiest way to + + align:start position:0% +scales sometimes the easiest way to + + + align:start position:0% +scales sometimes the easiest way to +think about it is to think of its + + align:start position:0% +think about it is to think of its + + + align:start position:0% +think about it is to think of its +opposite a push system is an + + align:start position:0% +opposite a push system is an + + + align:start position:0% +opposite a push system is an +old-fashioned mass production system + + align:start position:0% +old-fashioned mass production system + + + align:start position:0% +old-fashioned mass production system +where what you're trying to do is + + align:start position:0% +where what you're trying to do is + + + align:start position:0% +where what you're trying to do is +optimize the productivity of each step + + align:start position:0% +optimize the productivity of each step + + + align:start position:0% +optimize the productivity of each step +all right what that means is we set up + + align:start position:0% +all right what that means is we set up + + + align:start position:0% +all right what that means is we set up +our machine or we set up our process and + + align:start position:0% +our machine or we set up our process and + + + align:start position:0% +our machine or we set up our process and +we push a lot of material through it + + align:start position:0% +we push a lot of material through it + + + align:start position:0% +we push a lot of material through it +because that is the most efficient way + + align:start position:0% +because that is the most efficient way + + + align:start position:0% +because that is the most efficient way +to do most things is to set something up + + align:start position:0% +to do most things is to set something up + + + align:start position:0% +to do most things is to set something up +and then just bang stuff through it + + align:start position:0% +and then just bang stuff through it + + + align:start position:0% +and then just bang stuff through it +there was a question and people sort of + + align:start position:0% +there was a question and people sort of + + + align:start position:0% +there was a question and people sort of +intuitively understand that there was a + + align:start position:0% +intuitively understand that there was a + + + align:start position:0% +intuitively understand that there was a +question of like why don't we just + + align:start position:0% +question of like why don't we just + + + align:start position:0% +question of like why don't we just +automate it well to automate something + + align:start position:0% +automate it well to automate something + + + align:start position:0% +automate it well to automate something +you have to set up a process buy + + align:start position:0% +you have to set up a process buy + + + align:start position:0% +you have to set up a process buy +expensive equipment then when you're all + + align:start position:0% +expensive equipment then when you're all + + + align:start position:0% +expensive equipment then when you're all +done after doing all that prep work Boom + + align:start position:0% +done after doing all that prep work Boom + + + align:start position:0% +done after doing all that prep work Boom +the shoes just fly out the end and you + + align:start position:0% +the shoes just fly out the end and you + + + align:start position:0% +the shoes just fly out the end and you +can build huge piles of them but then + + align:start position:0% +can build huge piles of them but then + + + align:start position:0% +can build huge piles of them but then +the question is do people want them are + + align:start position:0% +the question is do people want them are + + + align:start position:0% +the question is do people want them are +they good are there is there quality + + align:start position:0% +they good are there is there quality + + + align:start position:0% +they good are there is there quality +issues is there issues with you know if + + align:start position:0% +issues is there issues with you know if + + + align:start position:0% +issues is there issues with you know if +you want to change the style how hard is + + align:start position:0% +you want to change the style how hard is + + + align:start position:0% +you want to change the style how hard is +that to do um so that's a push system a + + align:start position:0% +that to do um so that's a push system a + + + align:start position:0% +that to do um so that's a push system a +pull system is kind of the conceptual + + align:start position:0% +pull system is kind of the conceptual + + + align:start position:0% +pull system is kind of the conceptual +opposite of that stuff only happens if + + align:start position:0% +opposite of that stuff only happens if + + + align:start position:0% +opposite of that stuff only happens if +the customers want it and it happens + + align:start position:0% +the customers want it and it happens + + + align:start position:0% +the customers want it and it happens +hopefully quickly enough that the + + align:start position:0% +hopefully quickly enough that the + + + align:start position:0% +hopefully quickly enough that the +customer um is Satisfied by the process + + align:start position:0% +customer um is Satisfied by the process + + + align:start position:0% +customer um is Satisfied by the process +so it's triggered by the + + align:start position:0% +so it's triggered by the + + + align:start position:0% +so it's triggered by the +customer um and that is what New Balance + + align:start position:0% +customer um and that is what New Balance + + + align:start position:0% +customer um and that is what New Balance +was really striving for they had a + + align:start position:0% +was really striving for they had a + + + align:start position:0% +was really striving for they had a +three-day turn so the shoe store ordered + + align:start position:0% +three-day turn so the shoe store ordered + + + align:start position:0% +three-day turn so the shoe store ordered +shoes and in three days the shoes were + + align:start position:0% +shoes and in three days the shoes were + + + align:start position:0% +shoes and in three days the shoes were +manufactured all the way from raw + + align:start position:0% +manufactured all the way from raw + + + align:start position:0% +manufactured all the way from raw +materials and sent to the shoe store + + align:start position:0% +materials and sent to the shoe store + + + align:start position:0% +materials and sent to the shoe store +this both results in and necessitates a + + align:start position:0% +this both results in and necessitates a + + + align:start position:0% +this both results in and necessitates a +smooth flow with relatively modest + + align:start position:0% +smooth flow with relatively modest + + + align:start position:0% +smooth flow with relatively modest +batches um and relatively small weight + + align:start position:0% +batches um and relatively small weight + + + align:start position:0% +batches um and relatively small weight +Tim or it doesn't work so as a as a sort + + align:start position:0% +Tim or it doesn't work so as a as a sort + + + align:start position:0% +Tim or it doesn't work so as a as a sort +of an ideal it's worth trying for and + + align:start position:0% +of an ideal it's worth trying for and + + + align:start position:0% +of an ideal it's worth trying for and +inherently there's very little waste in + + align:start position:0% +inherently there's very little waste in + + + align:start position:0% +inherently there's very little waste in +that kind of system trouble is of course + + align:start position:0% +that kind of system trouble is of course + + + align:start position:0% +that kind of system trouble is of course +that's relatively hard to do so let's + + align:start position:0% +that's relatively hard to do so let's + + + align:start position:0% +that's relatively hard to do so let's +think about what we need to do um to to + + align:start position:0% +think about what we need to do um to to + + + align:start position:0% +think about what we need to do um to to +do a pull system like we saw at new + + align:start position:0% +do a pull system like we saw at new + + + align:start position:0% +do a pull system like we saw at new +balance pretty much requires flow you + + align:start position:0% +balance pretty much requires flow you + + + align:start position:0% +balance pretty much requires flow you +don't have to have perfect flow but if + + align:start position:0% +don't have to have perfect flow but if + + + align:start position:0% +don't have to have perfect flow but if +you don't have a system that flows + + align:start position:0% +you don't have a system that flows + + + align:start position:0% +you don't have a system that flows +reasonably well it's very hard to make + + align:start position:0% +reasonably well it's very hard to make + + + align:start position:0% +reasonably well it's very hard to make +it a pull system and you would like to + + align:start position:0% +it a pull system and you would like to + + + align:start position:0% +it a pull system and you would like to +have a fairly predictable cycle time + + align:start position:0% +have a fairly predictable cycle time + + + align:start position:0% +have a fairly predictable cycle time +here's a bunch of tools we're going to + + align:start position:0% +here's a bunch of tools we're going to + + + align:start position:0% +here's a bunch of tools we're going to +get into those in a while the point + + align:start position:0% +get into those in a while the point + + + align:start position:0% +get into those in a while the point +really with this slide is that to have + + align:start position:0% +really with this slide is that to have + + + align:start position:0% +really with this slide is that to have +pull you need if not all of these most + + align:start position:0% +pull you need if not all of these most + + + align:start position:0% +pull you need if not all of these most +of them you have to have a pretty lean + + align:start position:0% +of them you have to have a pretty lean + + + align:start position:0% +of them you have to have a pretty lean +system and again we'll get into what + + align:start position:0% +system and again we'll get into what + + + align:start position:0% +system and again we'll get into what +those are and a pull system starts with + + align:start position:0% +those are and a pull system starts with + + + align:start position:0% +those are and a pull system starts with +a customer and essentially the signals + + align:start position:0% +a customer and essentially the signals + + + align:start position:0% +a customer and essentially the signals +work backward Ward through the system + + align:start position:0% +work backward Ward through the system + + + align:start position:0% +work backward Ward through the system +what does that mean from the customer's + + align:start position:0% +what does that mean from the customer's + + + align:start position:0% +what does that mean from the customer's +point of view it means that either the + + align:start position:0% +point of view it means that either the + + + align:start position:0% +point of view it means that either the +cycle time is lower than my expectation + + align:start position:0% +cycle time is lower than my expectation + + + align:start position:0% +cycle time is lower than my expectation +for when my product will will be + + align:start position:0% +for when my product will will be + + + align:start position:0% +for when my product will will be +delivered or when my service will be + + align:start position:0% +delivered or when my service will be + + + align:start position:0% +delivered or when my service will be +delivered or there's or there's + + align:start position:0% +delivered or there's or there's + + + align:start position:0% +delivered or there's or there's +inventory in the system as a for example + + align:start position:0% +inventory in the system as a for example + + + align:start position:0% +inventory in the system as a for example +I ordered a computer a while ago that + + align:start position:0% +I ordered a computer a while ago that + + + align:start position:0% +I ordered a computer a while ago that +computer right there and I I sort of + + align:start position:0% +computer right there and I I sort of + + + align:start position:0% +computer right there and I I sort of +mentally budgeted a couple weeks you + + align:start position:0% +mentally budgeted a couple weeks you + + + align:start position:0% +mentally budgeted a couple weeks you +know you get the new computer put the + + align:start position:0% +know you get the new computer put the + + + align:start position:0% +know you get the new computer put the +files on it get used to the system um I + + align:start position:0% +files on it get used to the system um I + + + align:start position:0% +files on it get used to the system um I +ordered it online + + align:start position:0% +ordered it online + + + align:start position:0% +ordered it online +and it came in from China in less than + + align:start position:0% +and it came in from China in less than + + + align:start position:0% +and it came in from China in less than +48 hours less than two days so to me + + align:start position:0% +48 hours less than two days so to me + + + align:start position:0% +48 hours less than two days so to me +that was a pull system it was way inside + + align:start position:0% +that was a pull system it was way inside + + + align:start position:0% +that was a pull system it was way inside +my expectations so as far as I could you + + align:start position:0% +my expectations so as far as I could you + + + align:start position:0% +my expectations so as far as I could you +know as far as it felt I wanted it and + + align:start position:0% +know as far as it felt I wanted it and + + + align:start position:0% +know as far as it felt I wanted it and +it came um so that's a very nice system + + align:start position:0% +it came um so that's a very nice system + + + align:start position:0% +it came um so that's a very nice system +uh the system was actually originally + + align:start position:0% +uh the system was actually originally + + + align:start position:0% +uh the system was actually originally +invented by Dell computer Apple's really + + align:start position:0% +invented by Dell computer Apple's really + + + align:start position:0% +invented by Dell computer Apple's really +good at it now Dell still is actually + + align:start position:0% +good at it now Dell still is actually + + + align:start position:0% +good at it now Dell still is actually +although interestingly their Market has + + align:start position:0% +although interestingly their Market has + + + align:start position:0% +although interestingly their Market has +shifted more to um servers and + + align:start position:0% +shifted more to um servers and + + + align:start position:0% +shifted more to um servers and +Industrial uses of computers than than + + align:start position:0% +Industrial uses of computers than than + + + align:start position:0% +Industrial uses of computers than than +consumers but they were one of the + + align:start position:0% +consumers but they were one of the + + + align:start position:0% +consumers but they were one of the +original U inventors of essentially + + align:start position:0% +original U inventors of essentially + + + align:start position:0% +original U inventors of essentially +ordering something on the web and then + + align:start position:0% +ordering something on the web and then + + + align:start position:0% +ordering something on the web and then +having it built for you in a process + + align:start position:0% +having it built for you in a process + + + align:start position:0% +having it built for you in a process +that's it's not really automated but the + + align:start position:0% +that's it's not really automated but the + + + align:start position:0% +that's it's not really automated but the +process itself creates your computer + + align:start position:0% +process itself creates your computer + + + align:start position:0% +process itself creates your computer +there's there isn't a whole people don't + + align:start position:0% +there's there isn't a whole people don't + + + align:start position:0% +there's there isn't a whole people don't +think about the mcmanis order it's just + + align:start position:0% +think about the mcmanis order it's just + + + align:start position:0% +think about the mcmanis order it's just +you order that computer it goes into the + + align:start position:0% +you order that computer it goes into the + + + align:start position:0% +you order that computer it goes into the +system uh that that initiates the + + align:start position:0% +system uh that that initiates the + + + align:start position:0% +system uh that that initiates the +production of the computer um + + align:start position:0% +production of the computer um + + + align:start position:0% +production of the computer um +which goes very fast so it can ship the + + align:start position:0% +which goes very fast so it can ship the + + + align:start position:0% +which goes very fast so it can ship the +same day and then they have a really + + align:start position:0% +same day and then they have a really + + + align:start position:0% +same day and then they have a really +nice supply chain operation so it can + + align:start position:0% +nice supply chain operation so it can + + + align:start position:0% +nice supply chain operation so it can +come all the way from China in about 24 + + align:start position:0% +come all the way from China in about 24 + + + align:start position:0% +come all the way from China in about 24 +hours and you get your + + align:start position:0% +hours and you get your + + + align:start position:0% +hours and you get your +computer this has become a pretty + + align:start position:0% +computer this has become a pretty + + + align:start position:0% +computer this has become a pretty +standard for a lot of consumer products + + align:start position:0% +standard for a lot of consumer products + + + align:start position:0% +standard for a lot of consumer products +so the bar is gone up people are no + + align:start position:0% +so the bar is gone up people are no + + + align:start position:0% +so the bar is gone up people are no +longer mega mega impressed by this but + + align:start position:0% +longer mega mega impressed by this but + + + align:start position:0% +longer mega mega impressed by this but +it's actually pretty impressive that + + align:start position:0% +it's actually pretty impressive that + + + align:start position:0% +it's actually pretty impressive that +that people can do that on the on the + + align:start position:0% +that people can do that on the on the + + + align:start position:0% +that people can do that on the on the +sort of customer + + align:start position:0% +sort of customer + + + align:start position:0% +sort of customer +end a very useful concept when thinking + + align:start position:0% +end a very useful concept when thinking + + + align:start position:0% +end a very useful concept when thinking +about pull is Tac time if I want one I'm + + align:start position:0% +about pull is Tac time if I want one I'm + + + align:start position:0% +about pull is Tac time if I want one I'm +really thinking about you know what's + + align:start position:0% +really thinking about you know what's + + + align:start position:0% +really thinking about you know what's +the cycle time I expect right I want a + + align:start position:0% +the cycle time I expect right I want a + + + align:start position:0% +the cycle time I expect right I want a +computer in inside of a week okay so if + + align:start position:0% +computer in inside of a week okay so if + + + align:start position:0% +computer in inside of a week okay so if +I get it in two days I'm delighted um + + align:start position:0% +I get it in two days I'm delighted um + + + align:start position:0% +I get it in two days I'm delighted um +but if I'm you know Dell's current + + align:start position:0% +but if I'm you know Dell's current + + + align:start position:0% +but if I'm you know Dell's current +customers there are people like Google + + align:start position:0% +customers there are people like Google + + + align:start position:0% +customers there are people like Google +and I want a 100,000 computers then what + + align:start position:0% +and I want a 100,000 computers then what + + + align:start position:0% +and I want a 100,000 computers then what +we have to start thinking about is what + + align:start position:0% +we have to start thinking about is what + + + align:start position:0% +we have to start thinking about is what +is the pace at which I want those + + align:start position:0% +is the pace at which I want those + + + align:start position:0% +is the pace at which I want those +computers to show up uh and that's a + + align:start position:0% +computers to show up uh and that's a + + + align:start position:0% +computers to show up uh and that's a +really simple calculation actually and + + align:start position:0% +really simple calculation actually and + + + align:start position:0% +really simple calculation actually and +one that's very much worth doing even in + + align:start position:0% +one that's very much worth doing even in + + + align:start position:0% +one that's very much worth doing even in +processes that are less predictable than + + align:start position:0% +processes that are less predictable than + + + align:start position:0% +processes that are less predictable than +production uh things like engineering + + align:start position:0% +production uh things like engineering + + + align:start position:0% +production uh things like engineering +and Hospital processes this is actually + + align:start position:0% +and Hospital processes this is actually + + + align:start position:0% +and Hospital processes this is actually +very useful to do which is to just think + + align:start position:0% +very useful to do which is to just think + + + align:start position:0% +very useful to do which is to just think +about what's your available time a day a + + align:start position:0% +about what's your available time a day a + + + align:start position:0% +about what's your available time a day a +week a year whatever it is and what is + + align:start position:0% +week a year whatever it is and what is + + + align:start position:0% +week a year whatever it is and what is +the customer demand during that time so + + align:start position:0% +the customer demand during that time so + + + align:start position:0% +the customer demand during that time so +if I have a day uh and I have to + + align:start position:0% +if I have a day uh and I have to + + + align:start position:0% +if I have a day uh and I have to +see uh 16 patients what's my Tac time 8 + + align:start position:0% +see uh 16 patients what's my Tac time 8 + + + align:start position:0% +see uh 16 patients what's my Tac time 8 +hour a day 16 + + align:start position:0% +hour a day 16 + + + align:start position:0% +hour a day 16 +patients half hour right if I'm not + + align:start position:0% +patients half hour right if I'm not + + + align:start position:0% +patients half hour right if I'm not +seeing a patient every half hour I'm + + align:start position:0% +seeing a patient every half hour I'm + + + align:start position:0% +seeing a patient every half hour I'm +behind it's not it's not rocket science + + align:start position:0% +behind it's not it's not rocket science + + + align:start position:0% +behind it's not it's not rocket science +but um but it's a way of understanding + + align:start position:0% +but um but it's a way of understanding + + + align:start position:0% +but um but it's a way of understanding +what the customer demand is and if I + + align:start position:0% +what the customer demand is and if I + + + align:start position:0% +what the customer demand is and if I +hope to have anything resembling a pull + + align:start position:0% +hope to have anything resembling a pull + + + align:start position:0% +hope to have anything resembling a pull +system what kind of time constraints I + + align:start position:0% +system what kind of time constraints I + + + align:start position:0% +system what kind of time constraints I +have to stay within so there's a very + + align:start position:0% +have to stay within so there's a very + + + align:start position:0% +have to stay within so there's a very +simple an very simple calculation here + + align:start position:0% +simple an very simple calculation here + + + align:start position:0% +simple an very simple calculation here +which is basically the same one that we + + align:start position:0% +which is basically the same one that we + + + align:start position:0% +which is basically the same one that we +did uh for for our medical example um + + align:start position:0% +did uh for for our medical example um + + + align:start position:0% +did uh for for our medical example um +this is for 40 orders across a year of + + align:start position:0% +this is for 40 orders across a year of + + + align:start position:0% +this is for 40 orders across a year of +235 working days same idea this is what + + align:start position:0% +235 working days same idea this is what + + + align:start position:0% +235 working days same idea this is what +what H uh basically what is the pace at + + align:start position:0% +what H uh basically what is the pace at + + + align:start position:0% +what H uh basically what is the pace at +which we need to do work to satisfy the + + align:start position:0% +which we need to do work to satisfy the + + + align:start position:0% +which we need to do work to satisfy the +customer + + align:start position:0% +customer + + + align:start position:0% +customer +need well that's presuming that this is + + align:start position:0% +need well that's presuming that this is + + + align:start position:0% +need well that's presuming that this is +like on average but what if all 40 + + align:start position:0% +like on average but what if all 40 + + + align:start position:0% +like on average but what if all 40 +orders came in on the same day right + + align:start position:0% +orders came in on the same day right + + + align:start position:0% +orders came in on the same day right +yeah that's right Tac time is an average + + align:start position:0% +yeah that's right Tac time is an average + + + align:start position:0% +yeah that's right Tac time is an average +um the issue of irregularity we're going + + align:start position:0% +um the issue of irregularity we're going + + + align:start position:0% +um the issue of irregularity we're going +to explore a little later in the class + + align:start position:0% +to explore a little later in the class + + + align:start position:0% +to explore a little later in the class +it definitely makes things harder on the + + align:start position:0% +it definitely makes things harder on the + + + align:start position:0% +it definitely makes things harder on the +other hand if you're dead on average the + + align:start position:0% +other hand if you're dead on average the + + + align:start position:0% +other hand if you're dead on average the +no no amount of variation is going to + + align:start position:0% +no no amount of variation is going to + + + align:start position:0% +no no amount of variation is going to +help you variation almost never helps + + align:start position:0% +help you variation almost never helps + + + align:start position:0% +help you variation almost never helps +you so you start here right but yeah + + align:start position:0% +you so you start here right but yeah + + + align:start position:0% +you so you start here right but yeah +there is that issue of you know what if + + align:start position:0% +there is that issue of you know what if + + + align:start position:0% +there is that issue of you know what if +uh sorry for the aside but I was + + align:start position:0% +uh sorry for the aside but I was + + + align:start position:0% +uh sorry for the aside but I was +visiting Walmart one of their + + align:start position:0% +visiting Walmart one of their + + + align:start position:0% +visiting Walmart one of their +distribution centers they have an + + align:start position:0% +distribution centers they have an + + + align:start position:0% +distribution centers they have an +awesome supply chain they're very very + + align:start position:0% +awesome supply chain they're very very + + + align:start position:0% +awesome supply chain they're very very +good at what they do um they had this + + align:start position:0% +good at what they do um they had this + + + align:start position:0% +good at what they do um they had this +enormous Warehouse in the middle of + + align:start position:0% +enormous Warehouse in the middle of + + + align:start position:0% +enormous Warehouse in the middle of +nowhere uh with about a cubic mile of + + align:start position:0% +nowhere uh with about a cubic mile of + + + align:start position:0% +nowhere uh with about a cubic mile of +lawnmowers in it um I exaggerate a + + align:start position:0% +lawnmowers in it um I exaggerate a + + + align:start position:0% +lawnmowers in it um I exaggerate a +little bit but I think it was it was a + + align:start position:0% +little bit but I think it was it was a + + + align:start position:0% +little bit but I think it was it was a +good chunk of a mile long only maybe 100 + + align:start position:0% +good chunk of a mile long only maybe 100 + + + align:start position:0% +good chunk of a mile long only maybe 100 +ft wide and as many lawnmowers as you + + align:start position:0% +ft wide and as many lawnmowers as you + + + align:start position:0% +ft wide and as many lawnmowers as you +could stack before they started crushing + + align:start position:0% +could stack before they started crushing + + + align:start position:0% +could stack before they started crushing +each other not very lean right but + + align:start position:0% +each other not very lean right but + + + align:start position:0% +each other not very lean right but +that's because everyone wants a lawn + + align:start position:0% +that's because everyone wants a lawn + + + align:start position:0% +that's because everyone wants a lawn +mower + + align:start position:0% + + + + align:start position:0% + +when yeah like May right so sometimes + + align:start position:0% +when yeah like May right so sometimes + + + align:start position:0% +when yeah like May right so sometimes +you're just screwed but on the other + + align:start position:0% +you're just screwed but on the other + + + align:start position:0% +you're just screwed but on the other +hand the lawnmowers the reason that they + + align:start position:0% +hand the lawnmowers the reason that they + + + align:start position:0% +hand the lawnmowers the reason that they +built the lawnmower they stacked the + + align:start position:0% +built the lawnmower they stacked the + + + align:start position:0% +built the lawnmower they stacked the +lawnmowers up into The Big Cube is + + align:start position:0% +lawnmowers up into The Big Cube is + + + align:start position:0% +lawnmowers up into The Big Cube is +because the lawnmower Factory was + + align:start position:0% +because the lawnmower Factory was + + + align:start position:0% +because the lawnmower Factory was +working to T they just figured out over + + align:start position:0% +working to T they just figured out over + + + align:start position:0% +working to T they just figured out over +the whole year how many lawnmowers they + + align:start position:0% +the whole year how many lawnmowers they + + + align:start position:0% +the whole year how many lawnmowers they +did and they were just banging them out + + align:start position:0% +did and they were just banging them out + + + align:start position:0% +did and they were just banging them out +real efficiently at that rate and they + + align:start position:0% +real efficiently at that rate and they + + + align:start position:0% +real efficiently at that rate and they +just decided that the the best thing to + + align:start position:0% +just decided that the the best thing to + + + align:start position:0% +just decided that the the best thing to +do although they weren't happy about it + + align:start position:0% +do although they weren't happy about it + + + align:start position:0% +do although they weren't happy about it +was to pile them up and sell them all in + + align:start position:0% +was to pile them up and sell them all in + + + align:start position:0% +was to pile them up and sell them all in +May so the tax still actually you know + + align:start position:0% +May so the tax still actually you know + + + align:start position:0% +May so the tax still actually you know +over a year was it made sense just + + align:start position:0% +over a year was it made sense just + + + align:start position:0% +over a year was it made sense just +happened that they had to keep them all + + align:start position:0% +happened that they had to keep them all + + + align:start position:0% +happened that they had to keep them all +until May um okay so what's our attack + + align:start position:0% +until May um okay so what's our attack + + + align:start position:0% +until May um okay so what's our attack +time at um at our hot dog stand if we + + align:start position:0% +time at um at our hot dog stand if we + + + align:start position:0% +time at um at our hot dog stand if we +had 50 customers what would our attack + + align:start position:0% +had 50 customers what would our attack + + + align:start position:0% +had 50 customers what would our attack +time b i it's got a calculator they can + + align:start position:0% +time b i it's got a calculator they can + + + align:start position:0% +time b i it's got a calculator they can +bang that out four hours right which is + + align:start position:0% +bang that out four hours right which is + + + align:start position:0% +bang that out four hours right which is +some number of minutes which is some + + align:start position:0% +some number of minutes which is some + + + align:start position:0% +some number of minutes which is some +number of seconds 12.5 customers per + + align:start position:0% +number of seconds 12.5 customers per + + + align:start position:0% +number of seconds 12.5 customers per +hour so how many hours per + + align:start position:0% +hour so how many hours per + + + align:start position:0% +hour so how many hours per +customer and let's try to express that + + align:start position:0% +customer and let's try to express that + + + align:start position:0% +customer and let's try to express that +in seconds Let's see we got 240 + + align:start position:0% +in seconds Let's see we got 240 + + + align:start position:0% +in seconds Let's see we got 240 +minutes uh so we got about four and a + + align:start position:0% +minutes uh so we got about four and a + + + align:start position:0% +minutes uh so we got about four and a +half minutes how many seconds is that + + align:start position:0% +half minutes how many seconds is that + + + align:start position:0% +half minutes how many seconds is that +can somebody multiply that by 60 280 + + align:start position:0% +can somebody multiply that by 60 280 + + + align:start position:0% +can somebody multiply that by 60 280 +seconds okay + + align:start position:0% + + + + align:start position:0% + +all right and if we wanted 75 customers + + align:start position:0% +all right and if we wanted 75 customers + + + align:start position:0% +all right and if we wanted 75 customers +we'd need even less 192 okay that's for + + align:start position:0% +we'd need even less 192 okay that's for + + + align:start position:0% +we'd need even less 192 okay that's for + + align:start position:0% + + + align:start position:0% + + align:start position:0% + + + + align:start position:0% + +475 so we've computed a attack time and + + align:start position:0% +475 so we've computed a attack time and + + + align:start position:0% +475 so we've computed a attack time and +a cycle time for our hot dog stand and + + align:start position:0% +a cycle time for our hot dog stand and + + + align:start position:0% +a cycle time for our hot dog stand and +first order doesn't look good right our + + align:start position:0% +first order doesn't look good right our + + + align:start position:0% +first order doesn't look good right our +our cycle time is longer than our tack + + align:start position:0% +our cycle time is longer than our tack + + + align:start position:0% +our cycle time is longer than our tack +time but that's a little deceptive + + align:start position:0% +time but that's a little deceptive + + + align:start position:0% +time but that's a little deceptive +because there's two workers right it + + align:start position:0% +because there's two workers right it + + + align:start position:0% +because there's two workers right it +takes one hot dog dog this one order of + + align:start position:0% +takes one hot dog dog this one order of + + + align:start position:0% +takes one hot dog dog this one order of +two hot dogs about this this many + + align:start position:0% +two hot dogs about this this many + + + align:start position:0% +two hot dogs about this this many +seconds to get through the system but + + align:start position:0% +seconds to get through the system but + + + align:start position:0% +seconds to get through the system but +it's trading off between two workers so + + align:start position:0% +it's trading off between two workers so + + + align:start position:0% +it's trading off between two workers so +we can't just directly compare those + + align:start position:0% +we can't just directly compare those + + + align:start position:0% +we can't just directly compare those +still it probably makes us a little + + align:start position:0% +still it probably makes us a little + + + align:start position:0% +still it probably makes us a little +nervous that our our tack time the time + + align:start position:0% +nervous that our our tack time the time + + + align:start position:0% +nervous that our our tack time the time +that that the sort of average time we + + align:start position:0% +that that the sort of average time we + + + align:start position:0% +that that the sort of average time we +have to hit um is considerably lower + + align:start position:0% +have to hit um is considerably lower + + + align:start position:0% +have to hit um is considerably lower +than than the amount of time it actually + + align:start position:0% +than than the amount of time it actually + + + align:start position:0% +than than the amount of time it actually +takes we'll save that thought for a + + align:start position:0% +takes we'll save that thought for a + + + align:start position:0% +takes we'll save that thought for a +little + + align:start position:0% +little + + + align:start position:0% +little +later uh and move on to the thought of + + align:start position:0% +later uh and move on to the thought of + + + align:start position:0% +later uh and move on to the thought of +balance work + + align:start position:0% +balance work + + + align:start position:0% +balance work +actually again in this example it's + + align:start position:0% +actually again in this example it's + + + align:start position:0% +actually again in this example it's +pretty easy we got two workers so if + + align:start position:0% +pretty easy we got two workers so if + + + align:start position:0% +pretty easy we got two workers so if +their work is perfectly balanced they're + + align:start position:0% +their work is perfectly balanced they're + + + align:start position:0% +their work is perfectly balanced they're +kind of doing half the work each each + + align:start position:0% +kind of doing half the work each each + + + align:start position:0% +kind of doing half the work each each +right uh is that the case don't know um + + align:start position:0% +right uh is that the case don't know um + + + align:start position:0% +right uh is that the case don't know um +okay so we have U we have this example + + align:start position:0% +okay so we have U we have this example + + + align:start position:0% +okay so we have U we have this example +of a product that needs to be delivered + + align:start position:0% +of a product that needs to be delivered + + + align:start position:0% +of a product that needs to be delivered +every six days if it takes 30 build if + + align:start position:0% +every six days if it takes 30 build if + + + align:start position:0% +every six days if it takes 30 build if +it takes 30 days to build how can we do + + align:start position:0% +it takes 30 days to build how can we do + + + align:start position:0% +it takes 30 days to build how can we do +it well one thing we could do is split + + align:start position:0% +it well one thing we could do is split + + + align:start position:0% +it well one thing we could do is split +the J the job up into five pieces + + align:start position:0% +the J the job up into five pieces + + + align:start position:0% +the J the job up into five pieces +right and then they should take six days + + align:start position:0% +right and then they should take six days + + + align:start position:0% +right and then they should take six days +each so that would work and uh you know + + align:start position:0% +each so that would work and uh you know + + + align:start position:0% +each so that would work and uh you know +as unit one goes into uh the the + + align:start position:0% +as unit one goes into uh the the + + + align:start position:0% +as unit one goes into uh the the +production there takes a couple days to + + align:start position:0% +production there takes a couple days to + + + align:start position:0% +production there takes a couple days to +get things started oh that animation's + + align:start position:0% +get things started oh that animation's + + + align:start position:0% +get things started oh that animation's +taken off by itself I don't have to push + + align:start position:0% +taken off by itself I don't have to push + + + align:start position:0% +taken off by itself I don't have to push +the button anymore every six days a unit + + align:start position:0% +the button anymore every six days a unit + + + align:start position:0% +the button anymore every six days a unit +comes out right so we're making our + + align:start position:0% +comes out right so we're making our + + + align:start position:0% +comes out right so we're making our +attack time even though our cycle time + + align:start position:0% +attack time even though our cycle time + + + align:start position:0% +attack time even though our cycle time +is longer but we have five steps five + + align:start position:0% +is longer but we have five steps five + + + align:start position:0% +is longer but we have five steps five +workers five units of work and they're + + align:start position:0% +workers five units of work and they're + + + align:start position:0% +workers five units of work and they're +balanced they take the same if one of + + align:start position:0% +balanced they take the same if one of + + + align:start position:0% +balanced they take the same if one of +those processes take took eight days + + align:start position:0% +those processes take took eight days + + + align:start position:0% +those processes take took eight days +days would that + + align:start position:0% +days would that + + + align:start position:0% +days would that +work no it would take eight days to get + + align:start position:0% +work no it would take eight days to get + + + align:start position:0% +work no it would take eight days to get +this the attack time would basically go + + align:start position:0% +this the attack time would basically go + + + align:start position:0% +this the attack time would basically go +to eight days so again not rocket + + align:start position:0% +to eight days so again not rocket + + + align:start position:0% +to eight days so again not rocket +science fairly simple but if we look at + + align:start position:0% +science fairly simple but if we look at + + + align:start position:0% +science fairly simple but if we look at +existing processes you know if we're + + align:start position:0% +existing processes you know if we're + + + align:start position:0% +existing processes you know if we're +plotting this out it's easy if we look + + align:start position:0% +plotting this out it's easy if we look + + + align:start position:0% +plotting this out it's easy if we look +at existing processes they're very + + align:start position:0% +at existing processes they're very + + + align:start position:0% +at existing processes they're very +rarely balanced there usually is a + + align:start position:0% +rarely balanced there usually is a + + + align:start position:0% +rarely balanced there usually is a +bottleneck process or a problem where uh + + align:start position:0% +bottleneck process or a problem where uh + + + align:start position:0% +bottleneck process or a problem where uh +one step takes longer than some of the + + align:start position:0% +one step takes longer than some of the + + + align:start position:0% +one step takes longer than some of the +other ones so balance is a key concept + + align:start position:0% +other ones so balance is a key concept + + + align:start position:0% +other ones so balance is a key concept +standard work we've talked quite a lot + + align:start position:0% +standard work we've talked quite a lot + + + align:start position:0% +standard work we've talked quite a lot +about about the fact that uh if we can't + + align:start position:0% +about about the fact that uh if we can't + + + align:start position:0% +about about the fact that uh if we can't +standardize work um then we are um then + + align:start position:0% +standardize work um then we are um then + + + align:start position:0% +standardize work um then we are um then +it's very difficult to improve it single + + align:start position:0% +it's very difficult to improve it single + + + align:start position:0% +it's very difficult to improve it single +piece flow is a key concept that's kind + + align:start position:0% +piece flow is a key concept that's kind + + + align:start position:0% +piece flow is a key concept that's kind +of integral to the idea of pull that + + align:start position:0% +of integral to the idea of pull that + + + align:start position:0% +of integral to the idea of pull that +we're processing one unit at a time just + + align:start position:0% +we're processing one unit at a time just + + + align:start position:0% +we're processing one unit at a time just +like that illustration through all the + + align:start position:0% +like that illustration through all the + + + align:start position:0% +like that illustration through all the +steps to completion that's kind of an + + align:start position:0% +steps to completion that's kind of an + + + align:start position:0% +steps to completion that's kind of an +ideal it works great on a PowerPoint you + + align:start position:0% +ideal it works great on a PowerPoint you + + + align:start position:0% +ideal it works great on a PowerPoint you +know we can things are going one step at + + align:start position:0% +know we can things are going one step at + + + align:start position:0% +know we can things are going one step at +a time no inventory that's great in + + align:start position:0% +a time no inventory that's great in + + + align:start position:0% +a time no inventory that's great in +practice is sort of an ideal that we + + align:start position:0% +practice is sort of an ideal that we + + + align:start position:0% +practice is sort of an ideal that we +shoot towards we try to keep our batches + + align:start position:0% +shoot towards we try to keep our batches + + + align:start position:0% +shoot towards we try to keep our batches +small we try to make processes when we + + align:start position:0% +small we try to make processes when we + + + align:start position:0% +small we try to make processes when we +can line up so that the flow is H is + + align:start position:0% +can line up so that the flow is H is + + + align:start position:0% +can line up so that the flow is H is +single piece uh that's kind of the + + align:start position:0% +single piece uh that's kind of the + + + align:start position:0% +single piece uh that's kind of the +opposite again of of a batch and que + + align:start position:0% +opposite again of of a batch and que + + + align:start position:0% +opposite again of of a batch and que +where we make big batches of stuff and + + align:start position:0% +where we make big batches of stuff and + + + align:start position:0% +where we make big batches of stuff and +then it waits until until the next step + + align:start position:0% +then it waits until until the next step + + + align:start position:0% +then it waits until until the next step +is ready to take + + align:start position:0% +is ready to take + + + align:start position:0% +is ready to take +it this is a key conceptual tool for any + + align:start position:0% +it this is a key conceptual tool for any + + + align:start position:0% +it this is a key conceptual tool for any +kind of pull process it's called a + + align:start position:0% +kind of pull process it's called a + + + align:start position:0% +kind of pull process it's called a +manufacturing cell and we actually saw + + align:start position:0% +manufacturing cell and we actually saw + + + align:start position:0% +manufacturing cell and we actually saw +these in action um at New Balance + + align:start position:0% +these in action um at New Balance + + + align:start position:0% +these in action um at New Balance +um the classic cell is actually u-shaped + + align:start position:0% +um the classic cell is actually u-shaped + + + align:start position:0% +um the classic cell is actually u-shaped +people actually arrange arrange the + + align:start position:0% +people actually arrange arrange the + + + align:start position:0% +people actually arrange arrange the +stuff in a u on the factory floor + + align:start position:0% +stuff in a u on the factory floor + + + align:start position:0% +stuff in a u on the factory floor +because then the in and out are + + align:start position:0% +because then the in and out are + + + align:start position:0% +because then the in and out are +basically in the same place makes moving + + align:start position:0% +basically in the same place makes moving + + + align:start position:0% +basically in the same place makes moving +stuff around easier there's even + + align:start position:0% +stuff around easier there's even + + + align:start position:0% +stuff around easier there's even +interesting rules about whether you + + align:start position:0% +interesting rules about whether you + + + align:start position:0% +interesting rules about whether you +should be whether they should go + + align:start position:0% +should be whether they should go + + + align:start position:0% +should be whether they should go +clockwise or counterclockwise depending + + align:start position:0% +clockwise or counterclockwise depending + + + align:start position:0% +clockwise or counterclockwise depending +on whether you're right-handed or + + align:start position:0% +on whether you're right-handed or + + + align:start position:0% +on whether you're right-handed or +left-handed it's if you want to get into + + align:start position:0% +left-handed it's if you want to get into + + + align:start position:0% +left-handed it's if you want to get into +the ergometrics you can get very clever + + align:start position:0% +the ergometrics you can get very clever + + + align:start position:0% +the ergometrics you can get very clever +but the basic idea is okay if if we have + + align:start position:0% +but the basic idea is okay if if we have + + + align:start position:0% +but the basic idea is okay if if we have +some tasks that can be balanced that can + + align:start position:0% +some tasks that can be balanced that can + + + align:start position:0% +some tasks that can be balanced that can +can be made to take about the same time + + align:start position:0% +can be made to take about the same time + + + align:start position:0% +can be made to take about the same time +um and that aren't dependent on a big + + align:start position:0% +um and that aren't dependent on a big + + + align:start position:0% +um and that aren't dependent on a big +batch machine like those Cutters um then + + align:start position:0% +batch machine like those Cutters um then + + + align:start position:0% +batch machine like those Cutters um then +we can line them + + align:start position:0% +we can line them + + + align:start position:0% +we can line them +up balance them so they take about the + + align:start position:0% +up balance them so they take about the + + + align:start position:0% +up balance them so they take about the +same time and then put in a very + + align:start position:0% +same time and then put in a very + + + align:start position:0% +same time and then put in a very +interesting rule instead of a big + + align:start position:0% +interesting rule instead of a big + + + align:start position:0% +interesting rule instead of a big +complicated scheduling system we're + + align:start position:0% +complicated scheduling system we're + + + align:start position:0% +complicated scheduling system we're +going to say don't work unless the + + align:start position:0% +going to say don't work unless the + + + align:start position:0% +going to say don't work unless the +downstream process needs you to and you + + align:start position:0% +downstream process needs you to and you + + + align:start position:0% +downstream process needs you to and you +and you can tell whether it needs you to + + align:start position:0% +and you can tell whether it needs you to + + + align:start position:0% +and you can tell whether it needs you to +you don't even have to ask by the fact + + align:start position:0% +you don't even have to ask by the fact + + + align:start position:0% +you don't even have to ask by the fact +that their inventory bin is empty so + + align:start position:0% +that their inventory bin is empty so + + + align:start position:0% +that their inventory bin is empty so +very simple rule so in practice okay + + align:start position:0% +very simple rule so in practice okay + + + align:start position:0% +very simple rule so in practice okay +everybody has inventory nobody works + + align:start position:0% +everybody has inventory nobody works + + + align:start position:0% +everybody has inventory nobody works +until somebody the next process in line + + align:start position:0% +until somebody the next process in line + + + align:start position:0% +until somebody the next process in line +the internal or external customer takes + + align:start position:0% +the internal or external customer takes + + + align:start position:0% +the internal or external customer takes +the product away from here now task four + + align:start position:0% +the product away from here now task four + + + align:start position:0% +the product away from here now task four +starts to work to do that they they + + align:start position:0% +starts to work to do that they they + + + align:start position:0% +starts to work to do that they they +start using their inventory which means + + align:start position:0% +start using their inventory which means + + + align:start position:0% +start using their inventory which means +three starts working which means two + + align:start position:0% +three starts working which means two + + + align:start position:0% +three starts working which means two +starts working which means one starts + + align:start position:0% +starts working which means one starts + + + align:start position:0% +starts working which means one starts +working so now everybody's working oh + + align:start position:0% +working so now everybody's working oh + + + align:start position:0% +working so now everybody's working oh +and of course now we're out here so we + + align:start position:0% +and of course now we're out here so we + + + align:start position:0% +and of course now we're out here so we +have to go ask our internal or external + + align:start position:0% +have to go ask our internal or external + + + align:start position:0% +have to go ask our internal or external +supplier for more parts right for more + + align:start position:0% +supplier for more parts right for more + + + align:start position:0% +supplier for more parts right for more +stuff if everybody takes exactly the + + align:start position:0% +stuff if everybody takes exactly the + + + align:start position:0% +stuff if everybody takes exactly the +same amount of time my next click would + + align:start position:0% +same amount of time my next click would + + + align:start position:0% +same amount of time my next click would +get us back to the beginning right + + align:start position:0% +get us back to the beginning right + + + align:start position:0% +get us back to the beginning right +everything would go back to to everybody + + align:start position:0% +everything would go back to to everybody + + + align:start position:0% +everything would go back to to everybody +having uh work in front of them uh so + + align:start position:0% +having uh work in front of them uh so + + + align:start position:0% +having uh work in front of them uh so +they stop working no + + align:start position:0% +they stop working no + + + align:start position:0% +they stop working no +inventory Direct Customer pull it's just + + align:start position:0% +inventory Direct Customer pull it's just + + + align:start position:0% +inventory Direct Customer pull it's just +triggered by the customer taking the uh + + align:start position:0% +triggered by the customer taking the uh + + + align:start position:0% +triggered by the customer taking the uh +the item out of the inventory of one at + + align:start position:0% +the item out of the inventory of one at + + + align:start position:0% +the item out of the inventory of one at +the end in the real world some tasks + + align:start position:0% +the end in the real world some tasks + + + align:start position:0% +the end in the real world some tasks +maybe the balance isn't perfect these + + align:start position:0% +maybe the balance isn't perfect these + + + align:start position:0% +maybe the balance isn't perfect these +tasks finish first + + align:start position:0% +tasks finish first + + + align:start position:0% +tasks finish first +they notice now that there is inventory + + align:start position:0% +they notice now that there is inventory + + + align:start position:0% +they notice now that there is inventory +sitting there because this task is not + + align:start position:0% +sitting there because this task is not + + + align:start position:0% +sitting there because this task is not +ready to take it so they're finished + + align:start position:0% +ready to take it so they're finished + + + align:start position:0% +ready to take it so they're finished +they stop + + align:start position:0% +they stop + + + align:start position:0% +they stop +working um that seems inefficient but + + align:start position:0% +working um that seems inefficient but + + + align:start position:0% +working um that seems inefficient but +what good does it do if they keep + + align:start position:0% +what good does it do if they keep + + + align:start position:0% +what good does it do if they keep +working what happens if they keep + + align:start position:0% +working what happens if they keep + + + align:start position:0% +working what happens if they keep +working we have yeah it just creates + + align:start position:0% +working we have yeah it just creates + + + align:start position:0% +working we have yeah it just creates +more inventory right we can just pile up + + align:start position:0% +more inventory right we can just pile up + + + align:start position:0% +more inventory right we can just pile up +inventory here it's a that would be a + + align:start position:0% +inventory here it's a that would be a + + + align:start position:0% +inventory here it's a that would be a +waste of over production so that's + + align:start position:0% +waste of over production so that's + + + align:start position:0% +waste of over production so that's +that's a very simple but this is very + + align:start position:0% +that's a very simple but this is very + + + align:start position:0% +that's a very simple but this is very +practical in a manufacturing system and + + align:start position:0% +practical in a manufacturing system and + + + align:start position:0% +practical in a manufacturing system and +conceptually you can use it for things + + align:start position:0% +conceptually you can use it for things + + + align:start position:0% +conceptually you can use it for things +like engineering work um rapid drawing + + align:start position:0% +like engineering work um rapid drawing + + + align:start position:0% +like engineering work um rapid drawing +release people have set up cells where + + align:start position:0% +release people have set up cells where + + + align:start position:0% +release people have set up cells where +um you know that that horrible value + + align:start position:0% +um you know that that horrible value + + + align:start position:0% +um you know that that horrible value +stream we saw at the very beginning with + + align:start position:0% +stream we saw at the very beginning with + + + align:start position:0% +stream we saw at the very beginning with +all the lines going everywhere well that + + align:start position:0% +all the lines going everywhere well that + + + align:start position:0% +all the lines going everywhere well that +was to get one drawing out so if you + + align:start position:0% +was to get one drawing out so if you + + + align:start position:0% +was to get one drawing out so if you +just line the engineers up like this it + + align:start position:0% +just line the engineers up like this it + + + align:start position:0% +just line the engineers up like this it +makes as much sense as every as anything + + align:start position:0% +makes as much sense as every as anything + + + align:start position:0% +makes as much sense as every as anything +else it may not be perfectly efficient + + align:start position:0% +else it may not be perfectly efficient + + + align:start position:0% +else it may not be perfectly efficient +from the engineers point of view but it + + align:start position:0% +from the engineers point of view but it + + + align:start position:0% +from the engineers point of view but it +AB but it minimizes without any + + align:start position:0% +AB but it minimizes without any + + + align:start position:0% +AB but it minimizes without any +complicated control system the time the + + align:start position:0% +complicated control system the time the + + + align:start position:0% +complicated control system the time the +product spends in the system and that's + + align:start position:0% +product spends in the system and that's + + + align:start position:0% +product spends in the system and that's +the advantage of a pull system uh + + align:start position:0% +the advantage of a pull system uh + + + align:start position:0% +the advantage of a pull system uh +another example of + + align:start position:0% +another example of + + + align:start position:0% +another example of +pull as as a con Bond system we talked + + align:start position:0% +pull as as a con Bond system we talked + + + align:start position:0% +pull as as a con Bond system we talked +about that a little bit before + + align:start position:0% +about that a little bit before + + + align:start position:0% +about that a little bit before +essentially same + + align:start position:0% +essentially same + + + align:start position:0% +essentially same +rule um appearance of a conbine bin + + align:start position:0% +rule um appearance of a conbine bin + + + align:start position:0% +rule um appearance of a conbine bin +means that the downstream process wants + + align:start position:0% +means that the downstream process wants + + + align:start position:0% +means that the downstream process wants +uh Parts conbine card or bin some kind + + align:start position:0% +uh Parts conbine card or bin some kind + + + align:start position:0% +uh Parts conbine card or bin some kind +of signal uh the the difference here is + + align:start position:0% +of signal uh the the difference here is + + + align:start position:0% +of signal uh the the difference here is +that we're no longer in a cell we're no + + align:start position:0% +that we're no longer in a cell we're no + + + align:start position:0% +that we're no longer in a cell we're no +longer right next to the other process + + align:start position:0% +longer right next to the other process + + + align:start position:0% +longer right next to the other process +so we need some kind of signal now it + + align:start position:0% +so we need some kind of signal now it + + + align:start position:0% +so we need some kind of signal now it +could be a complicated order with legal + + align:start position:0% +could be a complicated order with legal + + + align:start position:0% +could be a complicated order with legal +and pages and or it could be a bin or a + + align:start position:0% +and pages and or it could be a bin or a + + + align:start position:0% +and pages and or it could be a bin or a +card something something simple that + + align:start position:0% +card something something simple that + + + align:start position:0% +card something something simple that +we've pre-arranged that says by you know + + align:start position:0% +we've pre-arranged that says by you know + + + align:start position:0% +we've pre-arranged that says by you know +I need work I need you to do work for me + + align:start position:0% +I need work I need you to do work for me + + + align:start position:0% +I need work I need you to do work for me +um of course you have to have standard + + align:start position:0% +um of course you have to have standard + + + align:start position:0% +um of course you have to have standard +processes for this you have to agree + + align:start position:0% +processes for this you have to agree + + + align:start position:0% +processes for this you have to agree +what this card means um but it does + + align:start position:0% +what this card means um but it does + + + align:start position:0% +what this card means um but it does +allow us to control even a fairly + + align:start position:0% +allow us to control even a fairly + + + align:start position:0% +allow us to control even a fairly +complicated system uh visually and even + + align:start position:0% +complicated system uh visually and even + + + align:start position:0% +complicated system uh visually and even +if it's geographically or + + align:start position:0% +if it's geographically or + + + align:start position:0% +if it's geographically or +organizationally separated again a very + + align:start position:0% +organizationally separated again a very + + + align:start position:0% +organizationally separated again a very +simple example if we have a supplier and + + align:start position:0% +simple example if we have a supplier and + + + align:start position:0% +simple example if we have a supplier and +a + + align:start position:0% +a + + + align:start position:0% +a +manufacturer this in this case we have + + align:start position:0% +manufacturer this in this case we have + + + align:start position:0% +manufacturer this in this case we have +physical bins in the New Balance video + + align:start position:0% +physical bins in the New Balance video + + + align:start position:0% +physical bins in the New Balance video +you saw those plastic bins that + + align:start position:0% +you saw those plastic bins that + + + align:start position:0% +you saw those plastic bins that +everybody was using to move the parts + + align:start position:0% +everybody was using to move the parts + + + align:start position:0% +everybody was using to move the parts +around it's very real very direct and + + align:start position:0% +around it's very real very direct and + + + align:start position:0% +around it's very real very direct and +physical if we run out we send the empty + + align:start position:0% +physical if we run out we send the empty + + + align:start position:0% +physical if we run out we send the empty +bin to the supplier they know what that + + align:start position:0% +bin to the supplier they know what that + + + align:start position:0% +bin to the supplier they know what that +means it means fill it up um so they + + align:start position:0% +means it means fill it up um so they + + + align:start position:0% +means it means fill it up um so they +work on it and they fill up the bin when + + align:start position:0% +work on it and they fill up the bin when + + + align:start position:0% +work on it and they fill up the bin when +it's full shipping Department knows that + + align:start position:0% +it's full shipping Department knows that + + + align:start position:0% +it's full shipping Department knows that +means to take it away um when it shows + + align:start position:0% +means to take it away um when it shows + + + align:start position:0% +means to take it away um when it shows +up the manufacturer uses it until the + + align:start position:0% +up the manufacturer uses it until the + + + align:start position:0% +up the manufacturer uses it until the +bin is empty back to the supplier + + align:start position:0% +bin is empty back to the supplier + + + align:start position:0% +bin is empty back to the supplier +self-perpetuating system even if these + + align:start position:0% +self-perpetuating system even if these + + + align:start position:0% +self-perpetuating system even if these +systems are not particularly well + + align:start position:0% +systems are not particularly well + + + align:start position:0% +systems are not particularly well +balanced or if or even if demand is is + + align:start position:0% +balanced or if or even if demand is is + + + align:start position:0% +balanced or if or even if demand is is +intermittent um it will operate uh with + + align:start position:0% +intermittent um it will operate uh with + + + align:start position:0% +intermittent um it will operate uh with +no outside interference no management + + align:start position:0% +no outside interference no management + + + align:start position:0% +no outside interference no management +effort uh and minimum inventory about + + align:start position:0% +effort uh and minimum inventory about + + + align:start position:0% +effort uh and minimum inventory about +the only trick in this is essentially + + align:start position:0% +the only trick in this is essentially + + + align:start position:0% +the only trick in this is essentially +how many bins if you only have one bin + + align:start position:0% +how many bins if you only have one bin + + + align:start position:0% +how many bins if you only have one bin +what's the + + align:start position:0% +what's the + + + align:start position:0% +what's the +problem yeah yeah you have to wait right + + align:start position:0% +problem yeah yeah you have to wait right + + + align:start position:0% +problem yeah yeah you have to wait right +the only the one you have to wait for + + align:start position:0% +the only the one you have to wait for + + + align:start position:0% +the only the one you have to wait for +the supplier to be finished before you + + align:start position:0% +the supplier to be finished before you + + + align:start position:0% +the supplier to be finished before you +can start working again which might be + + align:start position:0% +can start working again which might be + + + align:start position:0% +can start working again which might be +okay if it's a low demand product or + + align:start position:0% +okay if it's a low demand product or + + + align:start position:0% +okay if it's a low demand product or +something um this example we have four + + align:start position:0% +something um this example we have four + + + align:start position:0% +something um this example we have four +so it kind of continues round and around + + align:start position:0% +so it kind of continues round and around + + + align:start position:0% +so it kind of continues round and around +worst thing that can happen here is if + + align:start position:0% +worst thing that can happen here is if + + + align:start position:0% +worst thing that can happen here is if +there's no demand four bins worth pile + + align:start position:0% +there's no demand four bins worth pile + + + align:start position:0% +there's no demand four bins worth pile +up right because the supplier will keep + + align:start position:0% +up right because the supplier will keep + + + align:start position:0% +up right because the supplier will keep +moving until all bins are full so we + + align:start position:0% +moving until all bins are full so we + + + align:start position:0% +moving until all bins are full so we +could pile up four bins that's probably + + align:start position:0% +could pile up four bins that's probably + + + align:start position:0% +could pile up four bins that's probably +not horrible unless of course they're + + align:start position:0% +not horrible unless of course they're + + + align:start position:0% +not horrible unless of course they're +really expensive things so there's + + align:start position:0% +really expensive things so there's + + + align:start position:0% +really expensive things so there's +there's essentially a design knob on the + + align:start position:0% +there's essentially a design knob on the + + + align:start position:0% +there's essentially a design knob on the +system which is how many bins but that's + + align:start position:0% +system which is how many bins but that's + + + align:start position:0% +system which is how many bins but that's +it it's very simple um and we can tweak + + align:start position:0% +it it's very simple um and we can tweak + + + align:start position:0% +it it's very simple um and we can tweak +it as necessary by changing the number + + align:start position:0% +it as necessary by changing the number + + + align:start position:0% +it as necessary by changing the number +of + + align:start position:0% +of + + + align:start position:0% +of +Bin okay so that's that's conbine con + + align:start position:0% +Bin okay so that's that's conbine con + + + align:start position:0% +Bin okay so that's that's conbine con +Bond itself is kind of a visual control + + align:start position:0% +Bond itself is kind of a visual control + + + align:start position:0% +Bond itself is kind of a visual control +you see an empty bin you work um there's + + align:start position:0% +you see an empty bin you work um there's + + + align:start position:0% +you see an empty bin you work um there's +other kinds of uh visual controls that + + align:start position:0% +other kinds of uh visual controls that + + + align:start position:0% +other kinds of uh visual controls that +are referred to uh generically again + + align:start position:0% +are referred to uh generically again + + + align:start position:0% +are referred to uh generically again +with another Japanese word the word + + align:start position:0% +with another Japanese word the word + + + align:start position:0% +with another Japanese word the word +andon andon is kind of an adjective + + align:start position:0% +andon andon is kind of an adjective + + + align:start position:0% +andon andon is kind of an adjective +means visual control more or less um and + + align:start position:0% +means visual control more or less um and + + + align:start position:0% +means visual control more or less um and +you can have for example andon lights + + align:start position:0% +you can have for example andon lights + + + align:start position:0% +you can have for example andon lights +again in the video you may have seen you + + align:start position:0% +again in the video you may have seen you + + + align:start position:0% +again in the video you may have seen you +may have noticed in the background some + + align:start position:0% +may have noticed in the background some + + + align:start position:0% +may have noticed in the background some +uh lights like this very very standard + + align:start position:0% +uh lights like this very very standard + + + align:start position:0% +uh lights like this very very standard +practice now in manufacturing to have a + + align:start position:0% +practice now in manufacturing to have a + + + align:start position:0% +practice now in manufacturing to have a +little light Tower like that red means + + align:start position:0% +little light Tower like that red means + + + align:start position:0% +little light Tower like that red means +like the machine is broken or there's + + align:start position:0% +like the machine is broken or there's + + + align:start position:0% +like the machine is broken or there's +some serious problem it needs attention + + align:start position:0% +some serious problem it needs attention + + + align:start position:0% +some serious problem it needs attention +green means it's going fine yellow means + + align:start position:0% +green means it's going fine yellow means + + + align:start position:0% +green means it's going fine yellow means +maybe we're behind a little bit it + + align:start position:0% +maybe we're behind a little bit it + + + align:start position:0% +maybe we're behind a little bit it +allows you to just look across the + + align:start position:0% +allows you to just look across the + + + align:start position:0% +allows you to just look across the +factory floor see the state if + + align:start position:0% +factory floor see the state if + + + align:start position:0% +factory floor see the state if +everything's green it's Dandy if there's + + align:start position:0% +everything's green it's Dandy if there's + + + align:start position:0% +everything's green it's Dandy if there's +red stuff you got to go fix it if + + align:start position:0% +red stuff you got to go fix it if + + + align:start position:0% +red stuff you got to go fix it if +there's yellows that tells you what to + + align:start position:0% +there's yellows that tells you what to + + + align:start position:0% +there's yellows that tells you what to +worry about um it's only really useful + + align:start position:0% +worry about um it's only really useful + + + align:start position:0% +worry about um it's only really useful +if you do something about it though it's + + align:start position:0% +if you do something about it though it's + + + align:start position:0% +if you do something about it though it's +part of an active management system um + + align:start position:0% +part of an active management system um + + + align:start position:0% +part of an active management system um +another one is the andon cord this is + + align:start position:0% +another one is the andon cord this is + + + align:start position:0% +another one is the andon cord this is +the famous counterintuitive Japanese + + align:start position:0% +the famous counterintuitive Japanese + + + align:start position:0% +the famous counterintuitive Japanese +practice of basically having a cord in + + align:start position:0% +practice of basically having a cord in + + + align:start position:0% +practice of basically having a cord in +front of every employee that they can + + align:start position:0% +front of every employee that they can + + + align:start position:0% +front of every employee that they can +pull that stops the entire + + align:start position:0% +pull that stops the entire + + + align:start position:0% +pull that stops the entire +Factory um this is very scary even to + + align:start position:0% +Factory um this is very scary even to + + + align:start position:0% +Factory um this is very scary even to +this day to uh North American managers + + align:start position:0% +this day to uh North American managers + + + align:start position:0% +this day to uh North American managers +because any disgruntled person can pull + + align:start position:0% +because any disgruntled person can pull + + + align:start position:0% +because any disgruntled person can pull +the court and stop the entire Factory + + align:start position:0% +the court and stop the entire Factory + + + align:start position:0% +the court and stop the entire Factory +what's what's that about um but of + + align:start position:0% +what's what's that about um but of + + + align:start position:0% +what's what's that about um but of +course the way they use that is to draw + + align:start position:0% +course the way they use that is to draw + + + align:start position:0% +course the way they use that is to draw +attention to a serious problem if a + + align:start position:0% +attention to a serious problem if a + + + align:start position:0% +attention to a serious problem if a +quality problem is happening okay the + + align:start position:0% +quality problem is happening okay the + + + align:start position:0% +quality problem is happening okay the +parts don't fit um that's unacceptable + + align:start position:0% +parts don't fit um that's unacceptable + + + align:start position:0% +parts don't fit um that's unacceptable +at a at at a high quality production + + align:start position:0% +at a at at a high quality production + + + align:start position:0% +at a at at a high quality production +operation so they stop the line because + + align:start position:0% +operation so they stop the line because + + + align:start position:0% +operation so they stop the line because +if they don't that defective part is + + align:start position:0% +if they don't that defective part is + + + align:start position:0% +if they don't that defective part is +going to continue down the line get more + + align:start position:0% +going to continue down the line get more + + + align:start position:0% +going to continue down the line get more +parts piled on top of it until you have + + align:start position:0% +parts piled on top of it until you have + + + align:start position:0% +parts piled on top of it until you have +effect essentially a defective car so a + + align:start position:0% +effect essentially a defective car so a + + + align:start position:0% +effect essentially a defective car so a +washer or whatever is turned into a big + + align:start position:0% +washer or whatever is turned into a big + + + align:start position:0% +washer or whatever is turned into a big +problem it's actually better to stop and + + align:start position:0% +problem it's actually better to stop and + + + align:start position:0% +problem it's actually better to stop and +fix it it also provides a lot of + + align:start position:0% +fix it it also provides a lot of + + + align:start position:0% +fix it it also provides a lot of +motivation everybody comes over and + + align:start position:0% +motivation everybody comes over and + + + align:start position:0% +motivation everybody comes over and +fixes it right away because you know the + + align:start position:0% +fixes it right away because you know the + + + align:start position:0% +fixes it right away because you know the +line is stopped so the team leader + + align:start position:0% +line is stopped so the team leader + + + align:start position:0% +line is stopped so the team leader +Engineers whoever needs to come on over + + align:start position:0% +Engineers whoever needs to come on over + + + align:start position:0% +Engineers whoever needs to come on over +um and solve the + + align:start position:0% + + + + align:start position:0% + +problem that's the andon cord + + align:start position:0% +problem that's the andon cord + + + align:start position:0% +problem that's the andon cord +Concept Medical example Virginia Mason + + align:start position:0% +Concept Medical example Virginia Mason + + + align:start position:0% +Concept Medical example Virginia Mason +Medical Center they have a u essentially + + align:start position:0% +Medical Center they have a u essentially + + + align:start position:0% +Medical Center they have a u essentially +a policy that says that any of their + + align:start position:0% +a policy that says that any of their + + + align:start position:0% +a policy that says that any of their +5,000 employees + + align:start position:0% +5,000 employees + + + align:start position:0% +5,000 employees +can they don't exactly stop seeing + + align:start position:0% +can they don't exactly stop seeing + + + align:start position:0% +can they don't exactly stop seeing +patients but + + align:start position:0% +patients but + + + align:start position:0% +patients but +all attention is paid to this person if + + align:start position:0% +all attention is paid to this person if + + + align:start position:0% +all attention is paid to this person if +they if they uh declare it an andon cord + + align:start position:0% +they if they uh declare it an andon cord + + + align:start position:0% +they if they uh declare it an andon cord +action if there is a patient safety + + align:start position:0% +action if there is a patient safety + + + align:start position:0% +action if there is a patient safety +issue that needs to be dealt with + + align:start position:0% +issue that needs to be dealt with + + + align:start position:0% +issue that needs to be dealt with +immediately they can get as much + + align:start position:0% +immediately they can get as much + + + align:start position:0% +immediately they can get as much +attention as they need and this happens + + align:start position:0% +attention as they need and this happens + + + align:start position:0% +attention as they need and this happens +quite a bit um but um but it has also + + align:start position:0% +quite a bit um but um but it has also + + + align:start position:0% +quite a bit um but um but it has also +surfaced a lot of problems and and the + + align:start position:0% +surfaced a lot of problems and and the + + + align:start position:0% +surfaced a lot of problems and and the +real key here by the way is not that + + align:start position:0% +real key here by the way is not that + + + align:start position:0% +real key here by the way is not that +this is a very good quick solving + + align:start position:0% +this is a very good quick solving + + + align:start position:0% +this is a very good quick solving +problem problem solving method because + + align:start position:0% +problem problem solving method because + + + align:start position:0% +problem problem solving method because +it isn't it stop the line it could be + + align:start position:0% +it isn't it stop the line it could be + + + align:start position:0% +it isn't it stop the line it could be +potentially very expensive over + + align:start position:0% +potentially very expensive over + + + align:start position:0% +potentially very expensive over +something very small but that it + + align:start position:0% +something very small but that it + + + align:start position:0% +something very small but that it +surfaces problems if you if you have a + + align:start position:0% +surfaces problems if you if you have a + + + align:start position:0% +surfaces problems if you if you have a +problem of this magnitude you don't want + + align:start position:0% +problem of this magnitude you don't want + + + align:start position:0% +problem of this magnitude you don't want +to see it again so it surfaces the + + align:start position:0% +to see it again so it surfaces the + + + align:start position:0% +to see it again so it surfaces the +problem and uh allows uh people to pay + + align:start position:0% +problem and uh allows uh people to pay + + + align:start position:0% +problem and uh allows uh people to pay +attention to it find the root cause make + + align:start position:0% +attention to it find the root cause make + + + align:start position:0% +attention to it find the root cause make +it go away for good okay final step + + align:start position:0% +it go away for good okay final step + + + align:start position:0% +it go away for good okay final step +pursuing Perfection this is all about + + align:start position:0% +pursuing Perfection this is all about + + + align:start position:0% +pursuing Perfection this is all about +not quitting there's always more ways to + + align:start position:0% +not quitting there's always more ways to + + + align:start position:0% +not quitting there's always more ways to +eliminate there's always ways you can do + + align:start position:0% +eliminate there's always ways you can do + + + align:start position:0% +eliminate there's always ways you can do +things better there's always ways you + + align:start position:0% +things better there's always ways you + + + align:start position:0% +things better there's always ways you +can get the employees more involved so + + align:start position:0% +can get the employees more involved so + + + align:start position:0% +can get the employees more involved so +it's a it's a continuous process and + + align:start position:0% +it's a it's a continuous process and + + + align:start position:0% +it's a it's a continuous process and +we'll be talking about uh about that + + align:start position:0% +we'll be talking about uh about that + + + align:start position:0% +we'll be talking about uh about that +more later another tool a final tool for + + align:start position:0% +more later another tool a final tool for + + + align:start position:0% +more later another tool a final tool for +for for this afternoon uh five W put the + + align:start position:0% +for for this afternoon uh five W put the + + + align:start position:0% +for for this afternoon uh five W put the +seven the eight wastes and the six s's + + align:start position:0% +seven the eight wastes and the six s's + + + align:start position:0% +seven the eight wastes and the six s's +these are the five y's uh not the letter + + align:start position:0% +these are the five y's uh not the letter + + + align:start position:0% +these are the five y's uh not the letter +the uh the word um and the point of the + + align:start position:0% +the uh the word um and the point of the + + + align:start position:0% +the uh the word um and the point of the +five y's is to keep asking why fact the + + align:start position:0% +five y's is to keep asking why fact the + + + align:start position:0% +five y's is to keep asking why fact the +fact that there's a number is actually + + align:start position:0% +fact that there's a number is actually + + + align:start position:0% +fact that there's a number is actually +kind of bad because you you may not want + + align:start position:0% +kind of bad because you you may not want + + + align:start position:0% +kind of bad because you you may not want +to quit at five and three might be + + align:start position:0% +to quit at five and three might be + + + align:start position:0% +to quit at five and three might be +enough but here's an example um it's + + align:start position:0% +enough but here's an example um it's + + + align:start position:0% +enough but here's an example um it's +possibly apocryphal example about the + + align:start position:0% +possibly apocryphal example about the + + + align:start position:0% +possibly apocryphal example about the +Jefferson + + align:start position:0% +Jefferson + + + align:start position:0% +Jefferson +monument why is the Jeff Jefferson + + align:start position:0% +monument why is the Jeff Jefferson + + + align:start position:0% +monument why is the Jeff Jefferson +monument deteriorating because they wash + + align:start position:0% +monument deteriorating because they wash + + + align:start position:0% +monument deteriorating because they wash +it all the time why is it washed all the + + align:start position:0% +it all the time why is it washed all the + + + align:start position:0% +it all the time why is it washed all the +time because it has bird poop on it um + + align:start position:0% +time because it has bird poop on it um + + + align:start position:0% +time because it has bird poop on it um +why do they do that well because the + + align:start position:0% +why do they do that well because the + + + align:start position:0% +why do they do that well because the +birds are eating the spiders why are + + align:start position:0% +birds are eating the spiders why are + + + align:start position:0% +birds are eating the spiders why are +there spiders because they're eating + + align:start position:0% +there spiders because they're eating + + + align:start position:0% +there spiders because they're eating +Nats why are there gats cuz the lights + + align:start position:0% +Nats why are there gats cuz the lights + + + align:start position:0% +Nats why are there gats cuz the lights +are on all the time of course I had + + align:start position:0% +are on all the time of course I had + + + align:start position:0% +are on all the time of course I had +somebody did a class + + align:start position:0% +somebody did a class + + + align:start position:0% +somebody did a class +uh a couple times ago that said why are + + align:start position:0% +uh a couple times ago that said why are + + + align:start position:0% +uh a couple times ago that said why are +the lights on all the time because it's + + align:start position:0% +the lights on all the time because it's + + + align:start position:0% +the lights on all the time because it's +in a bad neighborhood + + align:start position:0% +in a bad neighborhood + + + align:start position:0% +in a bad neighborhood +but um so so maybe five is not the right + + align:start position:0% +but um so so maybe five is not the right + + + align:start position:0% +but um so so maybe five is not the right +number maybe less is okay maybe you need + + align:start position:0% +number maybe less is okay maybe you need + + + align:start position:0% +number maybe less is okay maybe you need +to go deeper so five fundamentals kind + + align:start position:0% +to go deeper so five fundamentals kind + + + align:start position:0% +to go deeper so five fundamentals kind +of work together pursuing Perfection may + + align:start position:0% +of work together pursuing Perfection may + + + align:start position:0% +of work together pursuing Perfection may +send you all the way back to the + + align:start position:0% +send you all the way back to the + + + align:start position:0% +send you all the way back to the +beginning this is kind of a strategic + + align:start position:0% +beginning this is kind of a strategic + + + align:start position:0% +beginning this is kind of a strategic +view the tactics and we're going to be + + align:start position:0% +view the tactics and we're going to be + + + align:start position:0% +view the tactics and we're going to be +talking about this for the rest of the + + align:start position:0% +talking about this for the rest of the + + + align:start position:0% +talking about this for the rest of the +week so I won't dwell well on it are uh + + align:start position:0% +week so I won't dwell well on it are uh + + + align:start position:0% +week so I won't dwell well on it are uh +in this Loop the plan do study act Loop + + align:start position:0% +in this Loop the plan do study act Loop + + + align:start position:0% +in this Loop the plan do study act Loop +so whenever you find something you need + + align:start position:0% +so whenever you find something you need + + + align:start position:0% +so whenever you find something you need +to + + align:start position:0% +to + + + align:start position:0% +to +fix you don't just willy-nilly fix it + + align:start position:0% +fix you don't just willy-nilly fix it + + + align:start position:0% +fix you don't just willy-nilly fix it +you go through an ordered process and it + + align:start position:0% +you go through an ordered process and it + + + align:start position:0% +you go through an ordered process and it +is through a series of these ordered + + align:start position:0% +is through a series of these ordered + + + align:start position:0% +is through a series of these ordered +processes that you actually uh improve + + align:start position:0% +processes that you actually uh improve + + + align:start position:0% +processes that you actually uh improve +your your value stream achieve your flow + + align:start position:0% +your your value stream achieve your flow + + + align:start position:0% +your your value stream achieve your flow +uh move push towards pull so we've + + align:start position:0% +uh move push towards pull so we've + + + align:start position:0% +uh move push towards pull so we've +actually gone through a bunch of stuff + + align:start position:0% +actually gone through a bunch of stuff + + + align:start position:0% +actually gone through a bunch of stuff +remember that huge chart at the + + align:start position:0% +remember that huge chart at the + + + align:start position:0% +remember that huge chart at the +beginning that nobody knew hardly any of + + align:start position:0% +beginning that nobody knew hardly any of + + + align:start position:0% +beginning that nobody knew hardly any of +the terms on well now you have at least + + align:start position:0% +the terms on well now you have at least + + + align:start position:0% +the terms on well now you have at least +been introduced to all of these quite a + + align:start position:0% +been introduced to all of these quite a + + + align:start position:0% +been introduced to all of these quite a +few hopefully at the top level I don't + + align:start position:0% +few hopefully at the top level I don't + + + align:start position:0% +few hopefully at the top level I don't +know whether you've absorbed all of + + align:start position:0% +know whether you've absorbed all of + + + align:start position:0% +know whether you've absorbed all of +those hopefully at the top level the + + align:start position:0% +those hopefully at the top level the + + + align:start position:0% +those hopefully at the top level the +concept of + + align:start position:0% +concept of + + + align:start position:0% +concept of +process the concept of thinking about + + align:start position:0% +process the concept of thinking about + + + align:start position:0% +process the concept of thinking about +customer value has sunk + + align:start position:0% +customer value has sunk + + + align:start position:0% +customer value has sunk +in and that some of the thoughts about + + align:start position:0% +in and that some of the thoughts about + + + align:start position:0% +in and that some of the thoughts about +making value flow couple of the simple + + align:start position:0% +making value flow couple of the simple + + + align:start position:0% +making value flow couple of the simple +tools have stuck particularly not on the + + align:start position:0% +tools have stuck particularly not on the + + + align:start position:0% +tools have stuck particularly not on the +chart but always uh a favorite of mine + + align:start position:0% +chart but always uh a favorite of mine + + + align:start position:0% +chart but always uh a favorite of mine +is that you at least started to + + align:start position:0% +is that you at least started to + + + align:start position:0% +is that you at least started to +appreciate the complexity of what time + + align:start position:0% +appreciate the complexity of what time + + + align:start position:0% +appreciate the complexity of what time +means in these processes and again we'll + + align:start position:0% +means in these processes and again we'll + + + align:start position:0% +means in these processes and again we'll +be doing a considerable exercise on that + + align:start position:0% +be doing a considerable exercise on that + + + align:start position:0% +be doing a considerable exercise on that +starting in just a few minutes so that's + + align:start position:0% +starting in just a few minutes so that's + + + align:start position:0% +starting in just a few minutes so that's +it for now \ No newline at end of file diff --git a/uMc-j5aQTH8.txt b/uMc-j5aQTH8.txt new file mode 100644 index 0000000000000000000000000000000000000000..1289320a8c5f4ebee715c6385139306266d01e8c --- /dev/null +++ b/uMc-j5aQTH8.txt @@ -0,0 +1,4032 @@ +align:start position:0% + +welcome to age 20. welcome to uh special + + align:start position:0% +welcome to age 20. welcome to uh special + + + align:start position:0% +welcome to age 20. welcome to uh special +relativity and let me start by wishing + + align:start position:0% +relativity and let me start by wishing + + + align:start position:0% +relativity and let me start by wishing +you all a happy new year uh happy new + + align:start position:0% +you all a happy new year uh happy new + + + align:start position:0% +you all a happy new year uh happy new +year 2021 i'm pretty sure this is going + + align:start position:0% +year 2021 i'm pretty sure this is going + + + align:start position:0% +year 2021 i'm pretty sure this is going +to be an exciting year with a lot of + + align:start position:0% +to be an exciting year with a lot of + + + align:start position:0% +to be an exciting year with a lot of +changes ahead and a lot of exciting + + align:start position:0% +changes ahead and a lot of exciting + + + align:start position:0% +changes ahead and a lot of exciting +events + + align:start position:0% +events + + + align:start position:0% +events +my name is marcus schluter and i will + + align:start position:0% +my name is marcus schluter and i will + + + align:start position:0% +my name is marcus schluter and i will +guide you through this iap lecture on + + align:start position:0% +guide you through this iap lecture on + + + align:start position:0% +guide you through this iap lecture on +special relativity + + align:start position:0% +special relativity + + + align:start position:0% +special relativity +this is very likely my favorite class at + + align:start position:0% +this is very likely my favorite class at + + + align:start position:0% +this is very likely my favorite class at +mit um + + align:start position:0% +mit um + + + align:start position:0% +mit um +a because it's iap and + + align:start position:0% +a because it's iap and + + + align:start position:0% +a because it's iap and +we start a new year there's a lot of + + align:start position:0% +we start a new year there's a lot of + + + align:start position:0% +we start a new year there's a lot of +excitement in the air and + + align:start position:0% +excitement in the air and + + + align:start position:0% +excitement in the air and +um we have a chance to focus for this + + align:start position:0% +um we have a chance to focus for this + + + align:start position:0% +um we have a chance to focus for this +one month of january + + align:start position:0% +one month of january + + + align:start position:0% +one month of january +on this specific subject + + align:start position:0% +on this specific subject + + + align:start position:0% +on this specific subject +b + + align:start position:0% +b + + + align:start position:0% +b +i have a chance to introduce a man + + align:start position:0% +i have a chance to introduce a man + + + align:start position:0% +i have a chance to introduce a man +albert einstein + + align:start position:0% +albert einstein + + + align:start position:0% +albert einstein +through a discussion of his physics + + align:start position:0% +through a discussion of his physics + + + align:start position:0% +through a discussion of his physics +through a discussion of him as a person + + align:start position:0% +through a discussion of him as a person + + + align:start position:0% +through a discussion of him as a person +and also + + align:start position:0% +and also + + + align:start position:0% +and also +through a discussion of the historic + + align:start position:0% +through a discussion of the historic + + + align:start position:0% +through a discussion of the historic +context in which he developed special + + align:start position:0% +context in which he developed special + + + align:start position:0% +context in which he developed special +relativity + + align:start position:0% +relativity + + + align:start position:0% +relativity +and see + + align:start position:0% +and see + + + align:start position:0% +and see +if this is the first time you encounter + + align:start position:0% +if this is the first time you encounter + + + align:start position:0% +if this is the first time you encounter +special relativity it will blow your + + align:start position:0% +special relativity it will blow your + + + align:start position:0% +special relativity it will blow your +mind and it actually is quite fun as an + + align:start position:0% +mind and it actually is quite fun as an + + + align:start position:0% +mind and it actually is quite fun as an +instructor to you know do a little bit + + align:start position:0% +instructor to you know do a little bit + + + align:start position:0% +instructor to you know do a little bit +of a transformation a new understanding + + align:start position:0% +of a transformation a new understanding + + + align:start position:0% +of a transformation a new understanding +on on physics so let's get started + + align:start position:0% +on on physics so let's get started + + + align:start position:0% +on on physics so let's get started +um with a quote with an einstein quote i + + align:start position:0% +um with a quote with an einstein quote i + + + align:start position:0% +um with a quote with an einstein quote i +have a number of those + + align:start position:0% +have a number of those + + + align:start position:0% +have a number of those +as we go through the class + + align:start position:0% +as we go through the class + + + align:start position:0% +as we go through the class +this one here is really you know kind of + + align:start position:0% +this one here is really you know kind of + + + align:start position:0% +this one here is really you know kind of +the theme of the class + + align:start position:0% +the theme of the class + + + align:start position:0% +the theme of the class +um let me just read this to you + + align:start position:0% +um let me just read this to you + + + align:start position:0% +um let me just read this to you +it is not the result of scientific + + align:start position:0% +it is not the result of scientific + + + align:start position:0% +it is not the result of scientific +research that enables humans and + + align:start position:0% +research that enables humans and + + + align:start position:0% +research that enables humans and +enriches their nature but the struggle + + align:start position:0% +enriches their nature but the struggle + + + align:start position:0% +enriches their nature but the struggle +to understand while performing creative + + align:start position:0% +to understand while performing creative + + + align:start position:0% +to understand while performing creative +and open-minded intellectual work + + align:start position:0% +and open-minded intellectual work + + + align:start position:0% +and open-minded intellectual work +it is really you know the struggle with + + align:start position:0% +it is really you know the struggle with + + + align:start position:0% +it is really you know the struggle with +the ideas really the trying to get + + align:start position:0% +the ideas really the trying to get + + + align:start position:0% +the ideas really the trying to get +understanding which ennobles humans and + + align:start position:0% +understanding which ennobles humans and + + + align:start position:0% +understanding which ennobles humans and +enriches their natures and let me add + + align:start position:0% +enriches their natures and let me add + + + align:start position:0% +enriches their natures and let me add +here um + + align:start position:0% +here um + + + align:start position:0% +here um +that through your own work um so your + + align:start position:0% +that through your own work um so your + + + align:start position:0% +that through your own work um so your +own mind you can transform yourself + + align:start position:0% +own mind you can transform yourself + + + align:start position:0% +own mind you can transform yourself +in your understanding of physics in + + align:start position:0% +in your understanding of physics in + + + align:start position:0% +in your understanding of physics in +general + + align:start position:0% +general + + + align:start position:0% +general +this first video and this first lecture + + align:start position:0% +this first video and this first lecture + + + align:start position:0% +this first video and this first lecture +will mostly be concerned with + + align:start position:0% +will mostly be concerned with + + + align:start position:0% +will mostly be concerned with +organizational + + align:start position:0% +organizational + + + align:start position:0% +organizational +topics so i'll lay out + + align:start position:0% +topics so i'll lay out + + + align:start position:0% +topics so i'll lay out +the schedule of the class and also how + + align:start position:0% +the schedule of the class and also how + + + align:start position:0% +the schedule of the class and also how +you get a grade or what kind of presets + + align:start position:0% +you get a grade or what kind of presets + + + align:start position:0% +you get a grade or what kind of presets +we have in mind and so on + + align:start position:0% +we have in mind and so on + + + align:start position:0% +we have in mind and so on +let's get started so i introduced myself + + align:start position:0% +let's get started so i introduced myself + + + align:start position:0% +let's get started so i introduced myself +already again marcus cluter you can + + align:start position:0% +already again marcus cluter you can + + + align:start position:0% +already again marcus cluter you can +reach me by email at clutter mit.edu we + + align:start position:0% +reach me by email at clutter mit.edu we + + + align:start position:0% +reach me by email at clutter mit.edu we +have a graduate ta justin his email is + + align:start position:0% +have a graduate ta justin his email is + + + align:start position:0% +have a graduate ta justin his email is +given on the slide as well and then we + + align:start position:0% +given on the slide as well and then we + + + align:start position:0% +given on the slide as well and then we +have two + + align:start position:0% +have two + + + align:start position:0% +have two +graders and tas mohit zak + + align:start position:0% +graders and tas mohit zak + + + align:start position:0% +graders and tas mohit zak +and steven + + align:start position:0% +and steven + + + align:start position:0% +and steven +those four + + align:start position:0% +those four + + + align:start position:0% +those four +will guide us through the class as well + + align:start position:0% +will guide us through the class as well + + + align:start position:0% +will guide us through the class as well +and especially when we go into breakout + + align:start position:0% +and especially when we go into breakout + + + align:start position:0% +and especially when we go into breakout +rooms in the live class they will help + + align:start position:0% +rooms in the live class they will help + + + align:start position:0% +rooms in the live class they will help +you + + align:start position:0% +you + + + align:start position:0% +you +in the discussion the class hours are + + align:start position:0% +in the discussion the class hours are + + + align:start position:0% +in the discussion the class hours are +from 3 to 4 30 p.m on zoom + + align:start position:0% +from 3 to 4 30 p.m on zoom + + + align:start position:0% +from 3 to 4 30 p.m on zoom +um + + align:start position:0% +um + + + align:start position:0% +um +and you can you know i encourage you to + + align:start position:0% +and you can you know i encourage you to + + + align:start position:0% +and you can you know i encourage you to +to join the class to + + align:start position:0% +to join the class to + + + align:start position:0% +to join the class to +participate to be active in the class + + align:start position:0% +participate to be active in the class + + + align:start position:0% +participate to be active in the class +but you will also be able to get to the + + align:start position:0% +but you will also be able to get to the + + + align:start position:0% +but you will also be able to get to the +material through recordings i will not + + align:start position:0% +material through recordings i will not + + + align:start position:0% +material through recordings i will not +record the live class because i want to + + align:start position:0% +record the live class because i want to + + + align:start position:0% +record the live class because i want to +encourage you to be just as open as + + align:start position:0% +encourage you to be just as open as + + + align:start position:0% +encourage you to be just as open as +possible but i pre-record the class and + + align:start position:0% +possible but i pre-record the class and + + + align:start position:0% +possible but i pre-record the class and +after the class time is over i'll upload + + align:start position:0% +after the class time is over i'll upload + + + align:start position:0% +after the class time is over i'll upload +those uh videos um for your for your + + align:start position:0% +those uh videos um for your for your + + + align:start position:0% +those uh videos um for your for your +reference and also if you live in a + + align:start position:0% +reference and also if you live in a + + + align:start position:0% +reference and also if you live in a +different time zone you have a chance to + + align:start position:0% +different time zone you have a chance to + + + align:start position:0% +different time zone you have a chance to +listen to the class + + align:start position:0% +listen to the class + + + align:start position:0% +listen to the class +office hours will be tuesday at 9 00 a.m + + align:start position:0% +office hours will be tuesday at 9 00 a.m + + + align:start position:0% +office hours will be tuesday at 9 00 a.m +and friday at 5am tuesday you reach me + + align:start position:0% +and friday at 5am tuesday you reach me + + + align:start position:0% +and friday at 5am tuesday you reach me +and friday you reach justin + + align:start position:0% +and friday you reach justin + + + align:start position:0% +and friday you reach justin +we will set up a slack workspace which + + align:start position:0% +we will set up a slack workspace which + + + align:start position:0% +we will set up a slack workspace which +uh we use for our internal discussions + + align:start position:0% +uh we use for our internal discussions + + + align:start position:0% +uh we use for our internal discussions +um with the teaching staff but um + + align:start position:0% +um with the teaching staff but um + + + align:start position:0% +um with the teaching staff but um +there's also going to be channels for + + align:start position:0% +there's also going to be channels for + + + align:start position:0% +there's also going to be channels for +you to discuss psets there's channels we + + align:start position:0% +you to discuss psets there's channels we + + + align:start position:0% +you to discuss psets there's channels we +discuss the physics + + align:start position:0% +discuss the physics + + + align:start position:0% +discuss the physics +and there's going to be a channel which + + align:start position:0% +and there's going to be a channel which + + + align:start position:0% +and there's going to be a channel which +will be important when we go to the to + + align:start position:0% +will be important when we go to the to + + + align:start position:0% +will be important when we go to the to +the exam discussion + + align:start position:0% +the exam discussion + + + align:start position:0% +the exam discussion +the expectation is that you spend about + + align:start position:0% +the expectation is that you spend about + + + align:start position:0% +the expectation is that you spend about +30 hours a week during iip + + align:start position:0% +30 hours a week during iip + + + align:start position:0% +30 hours a week during iip +some will find the presets very + + align:start position:0% +some will find the presets very + + + align:start position:0% +some will find the presets very +straightforward and quickly to do others + + align:start position:0% +straightforward and quickly to do others + + + align:start position:0% +straightforward and quickly to do others +will need more time so it's just it's + + align:start position:0% +will need more time so it's just it's + + + align:start position:0% +will need more time so it's just it's +not a you know don't set your stopwatch + + align:start position:0% +not a you know don't set your stopwatch + + + align:start position:0% +not a you know don't set your stopwatch +for 30 hours that's just an average + + align:start position:0% +for 30 hours that's just an average + + + align:start position:0% +for 30 hours that's just an average +guide + + align:start position:0% +guide + + + align:start position:0% +guide +um i will evaluate you at the end of the + + align:start position:0% +um i will evaluate you at the end of the + + + align:start position:0% +um i will evaluate you at the end of the +term um + + align:start position:0% +term um + + + align:start position:0% +term um +and i will use this this metric here 50 + + align:start position:0% +and i will use this this metric here 50 + + + align:start position:0% +and i will use this this metric here 50 +of your grade will come from the + + align:start position:0% +of your grade will come from the + + + align:start position:0% +of your grade will come from the +homework there's going to be five + + align:start position:0% +homework there's going to be five + + + align:start position:0% +homework there's going to be five +different homework assignments there's + + align:start position:0% +different homework assignments there's + + + align:start position:0% +different homework assignments there's +going to be two midterms with 15 each + + align:start position:0% +going to be two midterms with 15 each + + + align:start position:0% +going to be two midterms with 15 each +and one final with 20 + + align:start position:0% +and one final with 20 + + + align:start position:0% +and one final with 20 +if i do the mass correctly this should + + align:start position:0% +if i do the mass correctly this should + + + align:start position:0% +if i do the mass correctly this should +lead us to a hundred percent + + align:start position:0% +lead us to a hundred percent + + + align:start position:0% +lead us to a hundred percent +uh you earn an a with 90 percent b with + + align:start position:0% +uh you earn an a with 90 percent b with + + + align:start position:0% +uh you earn an a with 90 percent b with +75 percent i see the 60 percent or + + align:start position:0% +75 percent i see the 60 percent or + + + align:start position:0% +75 percent i see the 60 percent or +higher a d is 50 or higher and a failing + + align:start position:0% +higher a d is 50 or higher and a failing + + + align:start position:0% +higher a d is 50 or higher and a failing +grade is less than 50 + + align:start position:0% +grade is less than 50 + + + align:start position:0% +grade is less than 50 +so all lectures will be on zoom + + align:start position:0% +so all lectures will be on zoom + + + align:start position:0% +so all lectures will be on zoom +you find the zoom links on the canvas + + align:start position:0% +you find the zoom links on the canvas + + + align:start position:0% +you find the zoom links on the canvas +page and + + align:start position:0% +page and + + + align:start position:0% +page and +you probably found this already + + align:start position:0% +you probably found this already + + + align:start position:0% +you probably found this already +otherwise you wouldn't be able to find + + align:start position:0% +otherwise you wouldn't be able to find + + + align:start position:0% +otherwise you wouldn't be able to find +this video and again as i was saying the + + align:start position:0% +this video and again as i was saying the + + + align:start position:0% +this video and again as i was saying the +recordings will be available after class + + align:start position:0% + + + + align:start position:0% + +this is the schedule um let me start by + + align:start position:0% +this is the schedule um let me start by + + + align:start position:0% +this is the schedule um let me start by +uh explaining this picture there's a + + align:start position:0% +uh explaining this picture there's a + + + align:start position:0% +uh explaining this picture there's a +little thomas here and then a german ice + + align:start position:0% +little thomas here and then a german ice + + + align:start position:0% +little thomas here and then a german ice +train um this class + + align:start position:0% +train um this class + + + align:start position:0% +train um this class +the way i look at this class is + + align:start position:0% +the way i look at this class is + + + align:start position:0% +the way i look at this class is +a train which is just leaving the + + align:start position:0% +a train which is just leaving the + + + align:start position:0% +a train which is just leaving the +station right now and it will you know + + align:start position:0% +station right now and it will you know + + + align:start position:0% +station right now and it will you know +very slowly pick up space + + align:start position:0% +very slowly pick up space + + + align:start position:0% +very slowly pick up space +um pace + + align:start position:0% +um pace + + + align:start position:0% +um pace +um but + + align:start position:0% +um but + + + align:start position:0% +um but +you want to make sure that you stay on + + align:start position:0% +you want to make sure that you stay on + + + align:start position:0% +you want to make sure that you stay on +the train and you don't jump off because + + align:start position:0% +the train and you don't jump off because + + + align:start position:0% +the train and you don't jump off because +you know if this will one once it's + + align:start position:0% +you know if this will one once it's + + + align:start position:0% +you know if this will one once it's +picked up its pace will be a fast moving + + align:start position:0% +picked up its pace will be a fast moving + + + align:start position:0% +picked up its pace will be a fast moving +train + + align:start position:0% +train + + + align:start position:0% +train +and uh missing a few days in iap + + align:start position:0% +and uh missing a few days in iap + + + align:start position:0% +and uh missing a few days in iap +uh will cause you to have trouble + + align:start position:0% +uh will cause you to have trouble + + + align:start position:0% +uh will cause you to have trouble +following along with the material + + align:start position:0% +following along with the material + + + align:start position:0% +following along with the material +um we'll start today with this + + align:start position:0% +um we'll start today with this + + + align:start position:0% +um we'll start today with this +introduction um tomorrow we have a very + + align:start position:0% +introduction um tomorrow we have a very + + + align:start position:0% +introduction um tomorrow we have a very +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +uh lecture by david kaiser this is the + + align:start position:0% +uh lecture by david kaiser this is the + + + align:start position:0% +uh lecture by david kaiser this is the +only one where we actually record the + + align:start position:0% +only one where we actually record the + + + align:start position:0% +only one where we actually record the +live live event so we will record the + + align:start position:0% +live live event so we will record the + + + align:start position:0% +live live event so we will record the +zoom session + + align:start position:0% +zoom session + + + align:start position:0% +zoom session +um and then the rest will unfold i was + + align:start position:0% +um and then the rest will unfold i was + + + align:start position:0% +um and then the rest will unfold i was +also saying you find this red block here + + align:start position:0% +also saying you find this red block here + + + align:start position:0% +also saying you find this red block here +those are our midterms and the final + + align:start position:0% +those are our midterms and the final + + + align:start position:0% +those are our midterms and the final +on those days there's not going to be a + + align:start position:0% +on those days there's not going to be a + + + align:start position:0% +on those days there's not going to be a +live class + + align:start position:0% +live class + + + align:start position:0% +live class +but i will make the a final sorry the + + align:start position:0% +but i will make the a final sorry the + + + align:start position:0% +but i will make the a final sorry the +exam available + + align:start position:0% +exam available + + + align:start position:0% +exam available +for about 24 hours + + align:start position:0% +for about 24 hours + + + align:start position:0% +for about 24 hours +you should not spend more than an hour + + align:start position:0% +you should not spend more than an hour + + + align:start position:0% +you should not spend more than an hour +maybe an hour and a half on on on the + + align:start position:0% +maybe an hour and a half on on on the + + + align:start position:0% +maybe an hour and a half on on on the +exam and then submit once you're done + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +the exams are um + + align:start position:0% +the exams are um + + + align:start position:0% +the exams are um +open book in a sense that you can look + + align:start position:0% +open book in a sense that you can look + + + align:start position:0% +open book in a sense that you can look +at the textbooks and you can look at the + + align:start position:0% +at the textbooks and you can look at the + + + align:start position:0% +at the textbooks and you can look at the +course material + + align:start position:0% +course material + + + align:start position:0% +course material +but you are not supposed to you know do + + align:start position:0% +but you are not supposed to you know do + + + align:start position:0% +but you are not supposed to you know do +an online search for the solutions and + + align:start position:0% +an online search for the solutions and + + + align:start position:0% +an online search for the solutions and +you're also not supposed to discuss with + + align:start position:0% +you're also not supposed to discuss with + + + align:start position:0% +you're also not supposed to discuss with +your + + align:start position:0% +your + + + align:start position:0% +your +peers you can ask the clarifying + + align:start position:0% +peers you can ask the clarifying + + + align:start position:0% +peers you can ask the clarifying +question on one of the slack channels + + align:start position:0% +question on one of the slack channels + + + align:start position:0% +question on one of the slack channels +and we will be happy to answer as + + align:start position:0% +and we will be happy to answer as + + + align:start position:0% +and we will be happy to answer as +quickly as we see them + + align:start position:0% +quickly as we see them + + + align:start position:0% +quickly as we see them +but again this is an evaluation of your + + align:start position:0% +but again this is an evaluation of your + + + align:start position:0% +but again this is an evaluation of your +own performance and you should submit + + align:start position:0% +own performance and you should submit + + + align:start position:0% +own performance and you should submit +your own performance + + align:start position:0% +your own performance + + + align:start position:0% +your own performance +the psets are different in a sense that + + align:start position:0% +the psets are different in a sense that + + + align:start position:0% +the psets are different in a sense that +i encourage that you guys you know build + + align:start position:0% +i encourage that you guys you know build + + + align:start position:0% +i encourage that you guys you know build +small groups and work on them together + + align:start position:0% +small groups and work on them together + + + align:start position:0% +small groups and work on them together +um + + align:start position:0% +um + + + align:start position:0% +um +each pset then has to be submitted by + + align:start position:0% +each pset then has to be submitted by + + + align:start position:0% +each pset then has to be submitted by +you as an individual + + align:start position:0% +you as an individual + + + align:start position:0% +you as an individual +meaning that i don't want to see copies + + align:start position:0% +meaning that i don't want to see copies + + + align:start position:0% +meaning that i don't want to see copies +of presets of other folks i want your + + align:start position:0% +of presets of other folks i want your + + + align:start position:0% +of presets of other folks i want your +own answers in your own words to the + + align:start position:0% +own answers in your own words to the + + + align:start position:0% +own answers in your own words to the +questions + + align:start position:0% +questions + + + align:start position:0% +questions +um very important day in in january is + + align:start position:0% +um very important day in in january is + + + align:start position:0% +um very important day in in january is +martin luther + + align:start position:0% + + + + align:start position:0% + +gives us all a little bit of a breathing + + align:start position:0% +gives us all a little bit of a breathing + + + align:start position:0% +gives us all a little bit of a breathing +room an extra free day + + align:start position:0% +room an extra free day + + + align:start position:0% +room an extra free day +and you see that you know there's going + + align:start position:0% +and you see that you know there's going + + + align:start position:0% +and you see that you know there's going +to be + + align:start position:0% +to be + + + align:start position:0% +to be +um after the discussion at the very end + + align:start position:0% +um after the discussion at the very end + + + align:start position:0% +um after the discussion at the very end +after the final a special lecture where + + align:start position:0% +after the final a special lecture where + + + align:start position:0% +after the final a special lecture where +i introduced the topic of general + + align:start position:0% +i introduced the topic of general + + + align:start position:0% +i introduced the topic of general +relativity um which is not par part of + + align:start position:0% +relativity um which is not par part of + + + align:start position:0% +relativity um which is not par part of +the core + + align:start position:0% +the core + + + align:start position:0% +the core +content of especially of this special + + align:start position:0% +content of especially of this special + + + align:start position:0% +content of especially of this special +relativity class + + align:start position:0% +relativity class + + + align:start position:0% +relativity class +textbooks um i will not really follow + + align:start position:0% +textbooks um i will not really follow + + + align:start position:0% +textbooks um i will not really follow +the textbooks line by line or chapter by + + align:start position:0% +the textbooks line by line or chapter by + + + align:start position:0% +the textbooks line by line or chapter by +chapter but i encourage you and i give + + align:start position:0% +chapter but i encourage you and i give + + + align:start position:0% +chapter but i encourage you and i give +you an outline and to read them + + align:start position:0% +you an outline and to read them + + + align:start position:0% +you an outline and to read them +especially the first two one first one + + align:start position:0% +especially the first two one first one + + + align:start position:0% +especially the first two one first one +is by french the second one is by + + align:start position:0% +is by french the second one is by + + + align:start position:0% +is by french the second one is by +resnick + + align:start position:0% +resnick + + + align:start position:0% +resnick +the former the first one is a former mit + + align:start position:0% +the former the first one is a former mit + + + align:start position:0% +the former the first one is a former mit +professor + + align:start position:0% +professor + + + align:start position:0% +professor +you are supposed to read this book cover + + align:start position:0% +you are supposed to read this book cover + + + align:start position:0% +you are supposed to read this book cover +to cover and i give reading assignments + + align:start position:0% +to cover and i give reading assignments + + + align:start position:0% +to cover and i give reading assignments +on this + + align:start position:0% +on this + + + align:start position:0% +on this +resnick has a lot of good examples and + + align:start position:0% +resnick has a lot of good examples and + + + align:start position:0% +resnick has a lot of good examples and +problems and we will focus on the first + + align:start position:0% +problems and we will focus on the first + + + align:start position:0% +problems and we will focus on the first +four chapters of that book + + align:start position:0% +four chapters of that book + + + align:start position:0% +four chapters of that book +there is a lot of literature i would say + + align:start position:0% +there is a lot of literature i would say + + + align:start position:0% +there is a lot of literature i would say +on special relativity as a + + align:start position:0% +on special relativity as a + + + align:start position:0% +on special relativity as a +slew of textbooks available if you have + + align:start position:0% +slew of textbooks available if you have + + + align:start position:0% +slew of textbooks available if you have +one at hand you can also use that and + + align:start position:0% +one at hand you can also use that and + + + align:start position:0% +one at hand you can also use that and +find the relevant chapter in there + + align:start position:0% +find the relevant chapter in there + + + align:start position:0% +find the relevant chapter in there +um i give you one extra book here which + + align:start position:0% +um i give you one extra book here which + + + align:start position:0% +um i give you one extra book here which +is nice because it is + + align:start position:0% +is nice because it is + + + align:start position:0% +is nice because it is +an excellent + + align:start position:0% +an excellent + + + align:start position:0% +an excellent +explanation of the mathematics involved + + align:start position:0% +explanation of the mathematics involved + + + align:start position:0% +explanation of the mathematics involved +if you're more inclined + + align:start position:0% +if you're more inclined + + + align:start position:0% +if you're more inclined +to course course 18 that might be an + + align:start position:0% +to course course 18 that might be an + + + align:start position:0% +to course course 18 that might be an +interesting textbook for you + + align:start position:0% +interesting textbook for you + + + align:start position:0% +interesting textbook for you +again there's many many resources on the + + align:start position:0% +again there's many many resources on the + + + align:start position:0% +again there's many many resources on the +topic of special relativity and i've + + align:start position:0% +topic of special relativity and i've + + + align:start position:0% +topic of special relativity and i've +pointed out a few as we go + + align:start position:0% +pointed out a few as we go + + + align:start position:0% +pointed out a few as we go +in addition to the textbooks i give you + + align:start position:0% +in addition to the textbooks i give you + + + align:start position:0% +in addition to the textbooks i give you +a number of papers for example the paper + + align:start position:0% +a number of papers for example the paper + + + align:start position:0% +a number of papers for example the paper +in which einstein explains + + align:start position:0% +in which einstein explains + + + align:start position:0% +in which einstein explains +what describes the concept of the theory + + align:start position:0% +what describes the concept of the theory + + + align:start position:0% +what describes the concept of the theory +of special relativity + + align:start position:0% +of special relativity + + + align:start position:0% +of special relativity +and there's a few others which i'd like + + align:start position:0% +and there's a few others which i'd like + + + align:start position:0% +and there's a few others which i'd like +you to read they're interesting because + + align:start position:0% +you to read they're interesting because + + + align:start position:0% +you to read they're interesting because +they + + align:start position:0% +they + + + align:start position:0% +they +they introduce the physics but they're + + align:start position:0% +they introduce the physics but they're + + + align:start position:0% +they introduce the physics but they're +also interesting as they have been + + align:start position:0% +also interesting as they have been + + + align:start position:0% +also interesting as they have been +written more than 100 years ago in a + + align:start position:0% +written more than 100 years ago in a + + + align:start position:0% +written more than 100 years ago in a +slightly different language than we + + align:start position:0% +slightly different language than we + + + align:start position:0% +slightly different language than we +would be using today and + + align:start position:0% +would be using today and + + + align:start position:0% +would be using today and +einstein specifically doesn't even write + + align:start position:0% +einstein specifically doesn't even write + + + align:start position:0% +einstein specifically doesn't even write +papers the way other people wrote papers + + align:start position:0% +papers the way other people wrote papers + + + align:start position:0% +papers the way other people wrote papers +at the time + + align:start position:0% +at the time + + + align:start position:0% +at the time +he had his own style on the writing + + align:start position:0% +he had his own style on the writing + + + align:start position:0% +he had his own style on the writing +papers and we will see that + + align:start position:0% +papers and we will see that + + + align:start position:0% +papers and we will see that +so here's a reading assignment week by + + align:start position:0% +so here's a reading assignment week by + + + align:start position:0% +so here's a reading assignment week by +week + + align:start position:0% +week + + + align:start position:0% +week +you know we start in week one by resnick + + align:start position:0% +you know we start in week one by resnick + + + align:start position:0% +you know we start in week one by resnick +chapter one french chapter two there's + + align:start position:0% +chapter one french chapter two there's + + + align:start position:0% +chapter one french chapter two there's +two papers the michelson-morley paper + + align:start position:0% +two papers the michelson-morley paper + + + align:start position:0% +two papers the michelson-morley paper +and the einstein paper on special + + align:start position:0% +and the einstein paper on special + + + align:start position:0% +and the einstein paper on special +relativity and then we go on + + align:start position:0% +relativity and then we go on + + + align:start position:0% +relativity and then we go on +as we go through iap + + align:start position:0% +as we go through iap + + + align:start position:0% +as we go through iap +the homework schedule is here + + align:start position:0% +the homework schedule is here + + + align:start position:0% +the homework schedule is here +i hand out pset number zero today + + align:start position:0% +i hand out pset number zero today + + + align:start position:0% +i hand out pset number zero today +and i'll explain it on the next page + + align:start position:0% +and i'll explain it on the next page + + + align:start position:0% +and i'll explain it on the next page +this + + align:start position:0% +this + + + align:start position:0% +this +is a pset which allows i mean this is a + + align:start position:0% +is a pset which allows i mean this is a + + + align:start position:0% +is a pset which allows i mean this is a +preset which will keep you busy uh for + + align:start position:0% +preset which will keep you busy uh for + + + align:start position:0% +preset which will keep you busy uh for +the entire month or most of it on the + + align:start position:0% +the entire month or most of it on the + + + align:start position:0% +the entire month or most of it on the +other psets are + + align:start position:0% +other psets are + + + align:start position:0% +other psets are +shorter + + align:start position:0% +shorter + + + align:start position:0% +shorter +and they are more pointed and you know + + align:start position:0% +and they are more pointed and you know + + + align:start position:0% +and they are more pointed and you know +you get the pset you work on it and you + + align:start position:0% +you get the pset you work on it and you + + + align:start position:0% +you get the pset you work on it and you +hand in the solution and by the time you + + align:start position:0% +hand in the solution and by the time you + + + align:start position:0% +hand in the solution and by the time you +have done that the next piece rolls + + align:start position:0% +have done that the next piece rolls + + + align:start position:0% +have done that the next piece rolls +around + + align:start position:0% +around + + + align:start position:0% +around +i would use the pset load a little bit + + align:start position:0% +i would use the pset load a little bit + + + align:start position:0% +i would use the pset load a little bit +because i want to acknowledge the fact + + align:start position:0% +because i want to acknowledge the fact + + + align:start position:0% +because i want to acknowledge the fact +that it will be harder for you to work + + align:start position:0% +that it will be harder for you to work + + + align:start position:0% +that it will be harder for you to work +in teams i still encourage this uh you + + align:start position:0% +in teams i still encourage this uh you + + + align:start position:0% +in teams i still encourage this uh you +find yourself on slack you find yourself + + align:start position:0% +find yourself on slack you find yourself + + + align:start position:0% +find yourself on slack you find yourself +on zoom channel some of you might have + + align:start position:0% +on zoom channel some of you might have + + + align:start position:0% +on zoom channel some of you might have +housing together + + align:start position:0% +housing together + + + align:start position:0% +housing together +um i really encourage you guys to + + align:start position:0% +um i really encourage you guys to + + + align:start position:0% +um i really encourage you guys to +discuss the physics there are some + + align:start position:0% +discuss the physics there are some + + + align:start position:0% +discuss the physics there are some +really + + align:start position:0% +really + + + align:start position:0% +really +difficult concepts + + align:start position:0% +difficult concepts + + + align:start position:0% +difficult concepts +um which just need you to + + align:start position:0% +um which just need you to + + + align:start position:0% +um which just need you to +think through and to talk through and + + align:start position:0% +think through and to talk through and + + + align:start position:0% +think through and to talk through and +the talking through best happens with + + align:start position:0% +the talking through best happens with + + + align:start position:0% +the talking through best happens with +your peers and you will see that that + + align:start position:0% +your peers and you will see that that + + + align:start position:0% +your peers and you will see that that +will be very beneficial especially when + + align:start position:0% +will be very beneficial especially when + + + align:start position:0% +will be very beneficial especially when +it comes to the pset + + align:start position:0% + + + + align:start position:0% + +so here's homework number one um i've + + align:start position:0% +so here's homework number one um i've + + + align:start position:0% +so here's homework number one um i've +done this now a few times and i really + + align:start position:0% +done this now a few times and i really + + + align:start position:0% +done this now a few times and i really +really enjoy + + align:start position:0% +really enjoy + + + align:start position:0% +really enjoy +the + + align:start position:0% +the + + + align:start position:0% +the +solutions given by the students + + align:start position:0% +solutions given by the students + + + align:start position:0% +solutions given by the students +um so this is a creative project um + + align:start position:0% +um so this is a creative project um + + + align:start position:0% +um so this is a creative project um +you know you have basically almost all + + align:start position:0% +you know you have basically almost all + + + align:start position:0% +you know you have basically almost all +of irp to hand it in and the idea is to + + align:start position:0% +of irp to hand it in and the idea is to + + + align:start position:0% +of irp to hand it in and the idea is to +be creative around + + align:start position:0% +be creative around + + + align:start position:0% +be creative around +a topic relating einstein + + align:start position:0% +a topic relating einstein + + + align:start position:0% +a topic relating einstein +or and the special + + align:start position:0% +or and the special + + + align:start position:0% +or and the special +the + + align:start position:0% +the + + + align:start position:0% +the +serial of special relativity + + align:start position:0% +serial of special relativity + + + align:start position:0% +serial of special relativity +the project might be a video it might be + + align:start position:0% +the project might be a video it might be + + + align:start position:0% +the project might be a video it might be +a poem it might be a musical piece + + align:start position:0% +a poem it might be a musical piece + + + align:start position:0% +a poem it might be a musical piece +artwork animations + + align:start position:0% +artwork animations + + + align:start position:0% +artwork animations +a game + + align:start position:0% +a game + + + align:start position:0% +a game +a structure + + align:start position:0% +a structure + + + align:start position:0% +a structure +you name it + + align:start position:0% + + + + align:start position:0% + +what i really want is that you take + + align:start position:0% +what i really want is that you take + + + align:start position:0% +what i really want is that you take +something you do very well + + align:start position:0% +something you do very well + + + align:start position:0% +something you do very well +and combine it + + align:start position:0% +and combine it + + + align:start position:0% +and combine it +with the topic of this class um i want + + align:start position:0% +with the topic of this class um i want + + + align:start position:0% +with the topic of this class um i want +you to + + align:start position:0% +you to + + + align:start position:0% +you to +take something where you are very + + align:start position:0% +take something where you are very + + + align:start position:0% +take something where you are very +familiar with + + align:start position:0% +familiar with + + + align:start position:0% +familiar with +where you are feeling comfortable + + align:start position:0% +where you are feeling comfortable + + + align:start position:0% +where you are feeling comfortable +and then enter this new topic this new + + align:start position:0% +and then enter this new topic this new + + + align:start position:0% +and then enter this new topic this new +topic of special relativity + + align:start position:0% +topic of special relativity + + + align:start position:0% +topic of special relativity +i will + + align:start position:0% +i will + + + align:start position:0% +i will +rate it based on your creativity on the + + align:start position:0% +rate it based on your creativity on the + + + align:start position:0% +rate it based on your creativity on the +quality and on your effort + + align:start position:0% +quality and on your effort + + + align:start position:0% +quality and on your effort +and again this sends this in by january + + align:start position:0% +and again this sends this in by january + + + align:start position:0% +and again this sends this in by january +22nd i really encourage you to not wait + + align:start position:0% +22nd i really encourage you to not wait + + + align:start position:0% +22nd i really encourage you to not wait +to the last minute to start working on + + align:start position:0% +to the last minute to start working on + + + align:start position:0% +to the last minute to start working on +that those topics those creative + + align:start position:0% +that those topics those creative + + + align:start position:0% +that those topics those creative +projects they always take a little bit + + align:start position:0% +projects they always take a little bit + + + align:start position:0% +projects they always take a little bit +more time than you might expect + + align:start position:0% +more time than you might expect + + + align:start position:0% +more time than you might expect +this class will have + + align:start position:0% +this class will have + + + align:start position:0% +this class will have +an interactive component and + + align:start position:0% +an interactive component and + + + align:start position:0% +an interactive component and +we will use breakout rooms for + + align:start position:0% +we will use breakout rooms for + + + align:start position:0% +we will use breakout rooms for +discussions and + + align:start position:0% +discussions and + + + align:start position:0% +discussions and +smaller programs programs as you would + + align:start position:0% +smaller programs programs as you would + + + align:start position:0% +smaller programs programs as you would +be doing in the classroom as well + + align:start position:0% +be doing in the classroom as well + + + align:start position:0% +be doing in the classroom as well +here is the very first one um + + align:start position:0% +here is the very first one um + + + align:start position:0% +here is the very first one um +what people who are taking this class + + align:start position:0% +what people who are taking this class + + + align:start position:0% +what people who are taking this class +asynchronously i encourage you to stop + + align:start position:0% +asynchronously i encourage you to stop + + + align:start position:0% +asynchronously i encourage you to stop +here and + + align:start position:0% +here and + + + align:start position:0% +here and +work through the problem + + align:start position:0% +work through the problem + + + align:start position:0% +work through the problem +and then look at the solution afterwards + + align:start position:0% +and then look at the solution afterwards + + + align:start position:0% +and then look at the solution afterwards +or look at the discussion of the + + align:start position:0% +or look at the discussion of the + + + align:start position:0% +or look at the discussion of the +solution afterwards so this first duncan + + align:start position:0% +solution afterwards so this first duncan + + + align:start position:0% +solution afterwards so this first duncan +experiment thought experiment + + align:start position:0% +experiment thought experiment + + + align:start position:0% +experiment thought experiment +is about the topic of relativity + + align:start position:0% +is about the topic of relativity + + + align:start position:0% +is about the topic of relativity +and + + align:start position:0% +and + + + align:start position:0% +and +you know + + align:start position:0% +you know + + + align:start position:0% +you know +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you + + align:start position:0% +you + + + align:start position:0% +you +you want to first understand what that + + align:start position:0% +you want to first understand what that + + + align:start position:0% +you want to first understand what that +is before you do + + align:start position:0% +is before you do + + + align:start position:0% +is before you do +for what relativity is before you + + align:start position:0% +for what relativity is before you + + + align:start position:0% +for what relativity is before you +discuss what a special relativity is + + align:start position:0% +discuss what a special relativity is + + + align:start position:0% +discuss what a special relativity is +so imagine + + align:start position:0% +so imagine + + + align:start position:0% +so imagine +you wake up inside a room with no + + align:start position:0% +you wake up inside a room with no + + + align:start position:0% +you wake up inside a room with no +windows + + align:start position:0% +windows + + + align:start position:0% +windows +and + + align:start position:0% +and + + + align:start position:0% +and +one locked door you checked you make + + align:start position:0% +one locked door you checked you make + + + align:start position:0% +one locked door you checked you make +sure that the door is locked you cannot + + align:start position:0% +sure that the door is locked you cannot + + + align:start position:0% +sure that the door is locked you cannot +get out you cannot see outside looking + + align:start position:0% +get out you cannot see outside looking + + + align:start position:0% +get out you cannot see outside looking +out around you see a table with a number + + align:start position:0% +out around you see a table with a number + + + align:start position:0% +out around you see a table with a number +of items on it there's a desk lamp + + align:start position:0% +of items on it there's a desk lamp + + + align:start position:0% +of items on it there's a desk lamp +plugged in and turned on as a tennis + + align:start position:0% +plugged in and turned on as a tennis + + + align:start position:0% +plugged in and turned on as a tennis +ball + + align:start position:0% +ball + + + align:start position:0% +ball +there's a bunch of string + + align:start position:0% +there's a bunch of string + + + align:start position:0% +there's a bunch of string +there's a picture of water there's a cup + + align:start position:0% +there's a picture of water there's a cup + + + align:start position:0% +there's a picture of water there's a cup +there's a candle there's a box of + + align:start position:0% +there's a candle there's a box of + + + align:start position:0% +there's a candle there's a box of +matches and there's a music player with + + align:start position:0% +matches and there's a music player with + + + align:start position:0% +matches and there's a music player with +headphones + + align:start position:0% +headphones + + + align:start position:0% +headphones +a skateboard and a wooden stool are also + + align:start position:0% +a skateboard and a wooden stool are also + + + align:start position:0% +a skateboard and a wooden stool are also +in the room the music player has a sign + + align:start position:0% +in the room the music player has a sign + + + align:start position:0% +in the room the music player has a sign +on it saying turn it on for instructions + + align:start position:0% +on it saying turn it on for instructions + + + align:start position:0% +on it saying turn it on for instructions +so you do + + align:start position:0% +so you do + + + align:start position:0% +so you do +you're told that you're in a special + + align:start position:0% +you're told that you're in a special + + + align:start position:0% +you're told that you're in a special +specially designed vibration proof and + + align:start position:0% +specially designed vibration proof and + + + align:start position:0% +specially designed vibration proof and +noise proof train car + + align:start position:0% +noise proof train car + + + align:start position:0% +noise proof train car +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +on a set of straight and level train + + align:start position:0% +on a set of straight and level train + + + align:start position:0% +on a set of straight and level train +tracks + + align:start position:0% +tracks + + + align:start position:0% +tracks +your task is to use one or more of the + + align:start position:0% +your task is to use one or more of the + + + align:start position:0% +your task is to use one or more of the +items in the room + + align:start position:0% +items in the room + + + align:start position:0% +items in the room +perhaps in combination with each other + + align:start position:0% +perhaps in combination with each other + + + align:start position:0% +perhaps in combination with each other +to determine whether the train car is + + align:start position:0% +to determine whether the train car is + + + align:start position:0% +to determine whether the train car is +stationary or is moving on the tracks + + align:start position:0% +stationary or is moving on the tracks + + + align:start position:0% +stationary or is moving on the tracks +there's a 30 minute time limit on your + + align:start position:0% +there's a 30 minute time limit on your + + + align:start position:0% +there's a 30 minute time limit on your +test + + align:start position:0% +test + + + align:start position:0% +test +or tests + + align:start position:0% +or tests + + + align:start position:0% +or tests +and + + align:start position:0% +and + + + align:start position:0% +and +you cannot destroy or you cannot modify + + align:start position:0% +you cannot destroy or you cannot modify + + + align:start position:0% +you cannot destroy or you cannot modify +the walls or the floors or the seating + + align:start position:0% +the walls or the floors or the seating + + + align:start position:0% +the walls or the floors or the seating +of the car + + align:start position:0% +of the car + + + align:start position:0% +of the car +that is not permitted + + align:start position:0% +that is not permitted + + + align:start position:0% +that is not permitted +um so the question to you is can you + + align:start position:0% +um so the question to you is can you + + + align:start position:0% +um so the question to you is can you +think of some creative way + + align:start position:0% +think of some creative way + + + align:start position:0% +think of some creative way +to use the items that might indicate + + align:start position:0% +to use the items that might indicate + + + align:start position:0% +to use the items that might indicate +whether or not you're moving + + align:start position:0% +whether or not you're moving + + + align:start position:0% +whether or not you're moving +think about this and discuss your + + align:start position:0% +think about this and discuss your + + + align:start position:0% +think about this and discuss your +breakout rooms + + align:start position:0% +breakout rooms + + + align:start position:0% +breakout rooms +that is for the live session here again + + align:start position:0% +that is for the live session here again + + + align:start position:0% +that is for the live session here again +i want to encourage you to stop + + align:start position:0% +i want to encourage you to stop + + + align:start position:0% +i want to encourage you to stop +and to think about + + align:start position:0% +and to think about + + + align:start position:0% +and to think about +a solution can you think about a + + align:start position:0% +a solution can you think about a + + + align:start position:0% +a solution can you think about a +creative way + + align:start position:0% +creative way + + + align:start position:0% +creative way +to work with this + + align:start position:0% + + + + align:start position:0% + +the typical time is about 10 minutes you + + align:start position:0% +the typical time is about 10 minutes you + + + align:start position:0% +the typical time is about 10 minutes you +might want to think about it you might + + align:start position:0% +might want to think about it you might + + + align:start position:0% +might want to think about it you might +want to take some notes + + align:start position:0% +want to take some notes + + + align:start position:0% +want to take some notes +all right + + align:start position:0% +all right + + + align:start position:0% +all right +the answer is you cannot figure it out + + align:start position:0% +the answer is you cannot figure it out + + + align:start position:0% +the answer is you cannot figure it out +every reference frame by itself + + align:start position:0% +every reference frame by itself + + + align:start position:0% +every reference frame by itself +um + + align:start position:0% +um + + + align:start position:0% +um +is + + align:start position:0% +is + + + align:start position:0% +is +is + + align:start position:0% +is + + + align:start position:0% +is +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +inert you cannot figure out whether or + + align:start position:0% +inert you cannot figure out whether or + + + align:start position:0% +inert you cannot figure out whether or +not you're in a moving or in a in a + + align:start position:0% +not you're in a moving or in a in a + + + align:start position:0% +not you're in a moving or in a in a +stationary reference frame and as long + + align:start position:0% +stationary reference frame and as long + + + align:start position:0% +stationary reference frame and as long +as you cannot feel vibrations or you + + align:start position:0% +as you cannot feel vibrations or you + + + align:start position:0% +as you cannot feel vibrations or you +hear the sound or you have some other + + align:start position:0% +hear the sound or you have some other + + + align:start position:0% +hear the sound or you have some other +internal external indication you will + + align:start position:0% +internal external indication you will + + + align:start position:0% +internal external indication you will +not be able to figure out whether or not + + align:start position:0% +not be able to figure out whether or not + + + align:start position:0% +not be able to figure out whether or not +the room is moving with a constant + + align:start position:0% +the room is moving with a constant + + + align:start position:0% +the room is moving with a constant +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +you will be able to feel + + align:start position:0% +you will be able to feel + + + align:start position:0% +you will be able to feel +or measure accelerations + + align:start position:0% +or measure accelerations + + + align:start position:0% +or measure accelerations +and so now you could argue that you know + + align:start position:0% +and so now you could argue that you know + + + align:start position:0% +and so now you could argue that you know +since the train track is on earth and + + align:start position:0% +since the train track is on earth and + + + align:start position:0% +since the train track is on earth and +the earth + + align:start position:0% +the earth + + + align:start position:0% +the earth +is actually + + align:start position:0% +is actually + + + align:start position:0% +is actually +uh since since you're on on earth and if + + align:start position:0% +uh since since you're on on earth and if + + + align:start position:0% +uh since since you're on on earth and if +you're moving you would + + align:start position:0% +you're moving you would + + + align:start position:0% +you're moving you would +be able to feel + + align:start position:0% +be able to feel + + + align:start position:0% +be able to feel +the rotation of the earth there might be + + align:start position:0% +the rotation of the earth there might be + + + align:start position:0% +the rotation of the earth there might be +a way to figure this out um but that + + align:start position:0% +a way to figure this out um but that + + + align:start position:0% +a way to figure this out um but that +will be very very hard to do + + align:start position:0% + + + + align:start position:0% + +so the answer is you cannot you cannot + + align:start position:0% +so the answer is you cannot you cannot + + + align:start position:0% +so the answer is you cannot you cannot +distinguish one reference frame from + + align:start position:0% +distinguish one reference frame from + + + align:start position:0% +distinguish one reference frame from +another you don't know what an absolute + + align:start position:0% +another you don't know what an absolute + + + align:start position:0% +another you don't know what an absolute +velocity is + + align:start position:0% + + + + align:start position:0% + +so another way we will interact in this + + align:start position:0% +so another way we will interact in this + + + align:start position:0% +so another way we will interact in this +class is the concept questions so here + + align:start position:0% +class is the concept questions so here + + + align:start position:0% +class is the concept questions so here +concept questions are meant to you know + + align:start position:0% +concept questions are meant to you know + + + align:start position:0% +concept questions are meant to you know +give you a little bit of a checkpoint to + + align:start position:0% +give you a little bit of a checkpoint to + + + align:start position:0% +give you a little bit of a checkpoint to +encourage you to think about what i just + + align:start position:0% +encourage you to think about what i just + + + align:start position:0% +encourage you to think about what i just +explained in a video or in the class and + + align:start position:0% +explained in a video or in the class and + + + align:start position:0% +explained in a video or in the class and +to stimulate some sort of discussion + + align:start position:0% +to stimulate some sort of discussion + + + align:start position:0% +to stimulate some sort of discussion +sometimes you will use concept questions + + align:start position:0% +sometimes you will use concept questions + + + align:start position:0% +sometimes you will use concept questions +in breakout rooms for the discussion + + align:start position:0% +in breakout rooms for the discussion + + + align:start position:0% +in breakout rooms for the discussion +part + + align:start position:0% +part + + + align:start position:0% +part +sometimes we'll just use room features + + align:start position:0% +sometimes we'll just use room features + + + align:start position:0% +sometimes we'll just use room features +in order to figure out what + + align:start position:0% +in order to figure out what + + + align:start position:0% +in order to figure out what +the answer is but besides the technology + + align:start position:0% +the answer is but besides the technology + + + align:start position:0% +the answer is but besides the technology +those concept questions are really for + + align:start position:0% +those concept questions are really for + + + align:start position:0% +those concept questions are really for +you + + align:start position:0% +you + + + align:start position:0% +you +to figure out whether or not you did + + align:start position:0% +to figure out whether or not you did + + + align:start position:0% +to figure out whether or not you did +just understand the concept + + align:start position:0% +just understand the concept + + + align:start position:0% +just understand the concept +um so again i encourage you to + + align:start position:0% +um so again i encourage you to + + + align:start position:0% +um so again i encourage you to +you know + + align:start position:0% +you know + + + align:start position:0% +you know +pause the video to think about the + + align:start position:0% +pause the video to think about the + + + align:start position:0% +pause the video to think about the +concept question and then move on with + + align:start position:0% +concept question and then move on with + + + align:start position:0% +concept question and then move on with +the answer + + align:start position:0% +the answer + + + align:start position:0% +the answer +here's an example + + align:start position:0% +here's an example + + + align:start position:0% +here's an example +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +a new star wars movie came out + + align:start position:0% +a new star wars movie came out + + + align:start position:0% +a new star wars movie came out + + align:start position:0% + + + align:start position:0% +and i asked you to pick the answer + + align:start position:0% +and i asked you to pick the answer + + + align:start position:0% +and i asked you to pick the answer +closest to your level of starburst + + align:start position:0% +closest to your level of starburst + + + align:start position:0% +closest to your level of starburst +servers expertise + + align:start position:0% +servers expertise + + + align:start position:0% +servers expertise +i saw the movie and consider myself a + + align:start position:0% +i saw the movie and consider myself a + + + align:start position:0% +i saw the movie and consider myself a +star wars fan i saw the new movie but i + + align:start position:0% +star wars fan i saw the new movie but i + + + align:start position:0% +star wars fan i saw the new movie but i +do not know much about star wars i heard + + align:start position:0% +do not know much about star wars i heard + + + align:start position:0% +do not know much about star wars i heard +about star wars but i didn't see the + + align:start position:0% +about star wars but i didn't see the + + + align:start position:0% +about star wars but i didn't see the +movie yet always liked star trek better + + align:start position:0% +movie yet always liked star trek better + + + align:start position:0% +movie yet always liked star trek better +what star wars + + align:start position:0% +what star wars + + + align:start position:0% +what star wars +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +very straightforward here i would give + + align:start position:0% +very straightforward here i would give + + + align:start position:0% +very straightforward here i would give +you an option one two three or four we + + align:start position:0% +you an option one two three or four we + + + align:start position:0% +you an option one two three or four we +collect the answers and we get some + + align:start position:0% +collect the answers and we get some + + + align:start position:0% +collect the answers and we get some +feedback this is obviously there's no + + align:start position:0% +feedback this is obviously there's no + + + align:start position:0% +feedback this is obviously there's no +right answer here + + align:start position:0% +right answer here + + + align:start position:0% +right answer here +there can be concept questions where + + align:start position:0% +there can be concept questions where + + + align:start position:0% +there can be concept questions where +there is a right and the wrong answer + + align:start position:0% +there is a right and the wrong answer + + + align:start position:0% +there is a right and the wrong answer +and again for you this is supposed to + + align:start position:0% +and again for you this is supposed to + + + align:start position:0% +and again for you this is supposed to +give you feedback + + align:start position:0% +give you feedback + + + align:start position:0% +give you feedback +on how well you understood the concept + + align:start position:0% +on how well you understood the concept + + + align:start position:0% +on how well you understood the concept +all right before we close this first + + align:start position:0% +all right before we close this first + + + align:start position:0% +all right before we close this first +video i want to introduce players um + + align:start position:0% +video i want to introduce players um + + + align:start position:0% +video i want to introduce players um +alice and bob we will have um + + align:start position:0% +alice and bob we will have um + + + align:start position:0% +alice and bob we will have um +often discussions of reference frames + + align:start position:0% +often discussions of reference frames + + + align:start position:0% +often discussions of reference frames +typically alice or bob are in one + + align:start position:0% +typically alice or bob are in one + + + align:start position:0% +typically alice or bob are in one +reference frame and then the other + + align:start position:0% +reference frame and then the other + + + align:start position:0% +reference frame and then the other +person is in the other reference frame i + + align:start position:0% +person is in the other reference frame i + + + align:start position:0% +person is in the other reference frame i +want you to think about those star trek + + align:start position:0% +want you to think about those star trek + + + align:start position:0% +want you to think about those star trek +um figures um we will use + + align:start position:0% +um figures um we will use + + + align:start position:0% +um figures um we will use +spacecrafts we will use light + + align:start position:0% +spacecrafts we will use light + + + align:start position:0% +spacecrafts we will use light +so phasers or light + + align:start position:0% +so phasers or light + + + align:start position:0% +so phasers or light +pistols + + align:start position:0% +pistols + + + align:start position:0% +pistols +in order to + + align:start position:0% +in order to + + + align:start position:0% +in order to +demonstrate the impact of special + + align:start position:0% +demonstrate the impact of special + + + align:start position:0% +demonstrate the impact of special +relativity you understand understand the + + align:start position:0% +relativity you understand understand the + + + align:start position:0% +relativity you understand understand the +concepts + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/uOPuBNtv6Fk.txt b/uOPuBNtv6Fk.txt new file mode 100644 index 0000000000000000000000000000000000000000..277372661cba393ec3b954f1ed3f1956973dcda5 --- /dev/null +++ b/uOPuBNtv6Fk.txt @@ -0,0 +1,8155 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right so today when you keep on + + align:start position:0% +all right so today when you keep on + + + align:start position:0% +all right so today when you keep on +working on sarcastic and I guess maybe + + align:start position:0% +working on sarcastic and I guess maybe + + + align:start position:0% +working on sarcastic and I guess maybe +we start if you guys have questions from + + align:start position:0% +we start if you guys have questions from + + + align:start position:0% +we start if you guys have questions from +the homework set since I'm sure you're + + align:start position:0% +the homework set since I'm sure you're + + + align:start position:0% +the homework set since I'm sure you're +thinking about that a lot right now are + + align:start position:0% +thinking about that a lot right now are + + + align:start position:0% +thinking about that a lot right now are +there any questions so do I take this to + + align:start position:0% +there any questions so do I take this to + + + align:start position:0% +there any questions so do I take this to +mean you have a completely under control + + align:start position:0% + + + + align:start position:0% + +that's good + + align:start position:0% +that's good + + + align:start position:0% +that's good +all right all right so since we have + + align:start position:0% +all right all right so since we have + + + align:start position:0% +all right all right so since we have +Monte Carlo integration metropolis + + align:start position:0% +Monte Carlo integration metropolis + + + align:start position:0% +Monte Carlo integration metropolis +totally under control + + align:start position:0% +totally under control + + + align:start position:0% +totally under control +let's talk about time dependent + + align:start position:0% +let's talk about time dependent + + + align:start position:0% +let's talk about time dependent +probability distributions so in many + + align:start position:0% +probability distributions so in many + + + align:start position:0% +probability distributions so in many +situations + + align:start position:0% +situations + + + align:start position:0% +situations +we'd like to predict what's going to + + align:start position:0% +we'd like to predict what's going to + + + align:start position:0% +we'd like to predict what's going to +happen in an experiment and the + + align:start position:0% +happen in an experiment and the + + + align:start position:0% +happen in an experiment and the +fundamental equation side experiment or + + align:start position:0% +fundamental equation side experiment or + + + align:start position:0% +fundamental equation side experiment or +time dependent so we have different + + align:start position:0% +time dependent so we have different + + + align:start position:0% +time dependent so we have different +things happening at different times and + + align:start position:0% +things happening at different times and + + + align:start position:0% +things happening at different times and +so we really want to know what D DT of + + align:start position:0% +so we really want to know what D DT of + + + align:start position:0% +so we really want to know what D DT of +the probability of some observable + + align:start position:0% + + + + align:start position:0% + +all right so he wants an equation like + + align:start position:0% +all right so he wants an equation like + + + align:start position:0% +all right so he wants an equation like +this and then when you actually made + + align:start position:0% +this and then when you actually made + + + align:start position:0% +this and then when you actually made +your measurement + + align:start position:0% +your measurement + + + align:start position:0% +your measurement +you'd be sampling from P so probability + + align:start position:0% +you'd be sampling from P so probability + + + align:start position:0% +you'd be sampling from P so probability +of the observables and so if you made + + align:start position:0% +of the observables and so if you made + + + align:start position:0% +of the observables and so if you made +the measurement you'd have a certain + + align:start position:0% +the measurement you'd have a certain + + + align:start position:0% +the measurement you'd have a certain +probability you'd observe something and + + align:start position:0% +probability you'd observe something and + + + align:start position:0% +probability you'd observe something and +you made a different measurement you'd + + align:start position:0% +you made a different measurement you'd + + + align:start position:0% +you made a different measurement you'd +have some prove the same probability you + + align:start position:0% +have some prove the same probability you + + + align:start position:0% +have some prove the same probability you +made the measurement at this time so + + align:start position:0% +made the measurement at this time so + + + align:start position:0% +made the measurement at this time so +this is gonna be probably the derivative + + align:start position:0% +this is gonna be probably the derivative + + + align:start position:0% +this is gonna be probably the derivative +all depending on the time and you made + + align:start position:0% +all depending on the time and you made + + + align:start position:0% +all depending on the time and you made +the measurements at different times so + + align:start position:0% +the measurements at different times so + + + align:start position:0% +the measurements at different times so +let's conceptually think about this + + align:start position:0% +let's conceptually think about this + + + align:start position:0% +let's conceptually think about this +suppose we had a box and it had a + + align:start position:0% +suppose we had a box and it had a + + + align:start position:0% +suppose we had a box and it had a +uranium atom in it that's radioactive + + align:start position:0% +uranium atom in it that's radioactive + + + align:start position:0% +uranium atom in it that's radioactive +and it can decay so we look in the box + + align:start position:0% +and it can decay so we look in the box + + + align:start position:0% +and it can decay so we look in the box +and at time zero I look in there and + + align:start position:0% +and at time zero I look in there and + + + align:start position:0% +and at time zero I look in there and +there's uranium atoms sitting there + + align:start position:0% +there's uranium atoms sitting there + + + align:start position:0% +there's uranium atoms sitting there +nicely and I go away for a while I come + + align:start position:0% +nicely and I go away for a while I come + + + align:start position:0% +nicely and I go away for a while I come +back and I open the box I looking again + + align:start position:0% +back and I open the box I looking again + + + align:start position:0% +back and I open the box I looking again +later and there's some probability that + + align:start position:0% +later and there's some probability that + + + align:start position:0% +later and there's some probability that +the uranium atom is still there and + + align:start position:0% +the uranium atom is still there and + + + align:start position:0% +the uranium atom is still there and +there's some probability that it fission + + align:start position:0% +there's some probability that it fission + + + align:start position:0% +there's some probability that it fission +during the time and it's gone right okay + + align:start position:0% +during the time and it's gone right okay + + + align:start position:0% +during the time and it's gone right okay +so there must be some kind of equation + + align:start position:0% +so there must be some kind of equation + + + align:start position:0% +so there must be some kind of equation +like this how the probability that the + + align:start position:0% +like this how the probability that the + + + align:start position:0% +like this how the probability that the +uranium atom is still there in the box + + align:start position:0% +uranium atom is still there in the box + + + align:start position:0% +uranium atom is still there in the box +right this okay yeah so just for that + + align:start position:0% +right this okay yeah so just for that + + + align:start position:0% +right this okay yeah so just for that +case yeah what do we think that + + align:start position:0% +case yeah what do we think that + + + align:start position:0% +case yeah what do we think that +probability how does that probably + + align:start position:0% +probability how does that probably + + + align:start position:0% +probability how does that probably +behave yes + + align:start position:0% + + + + align:start position:0% + +so uranium has a half-life or something + + align:start position:0% +so uranium has a half-life or something + + + align:start position:0% +so uranium has a half-life or something +right yeah you guys heard this before + + align:start position:0% +right yeah you guys heard this before + + + align:start position:0% +right yeah you guys heard this before +right so so let's just try to think of + + align:start position:0% +right so so let's just try to think of + + + align:start position:0% +right so so let's just try to think of +how this should scale whenever it is + + align:start position:0% +how this should scale whenever it is + + + align:start position:0% +how this should scale whenever it is +probably should have something to do + + align:start position:0% +probably should have something to do + + + align:start position:0% +probably should have something to do +with the time constant for how fast + + align:start position:0% +with the time constant for how fast + + + align:start position:0% +with the time constant for how fast +uranium decays yeah you guys look at me + + align:start position:0% +uranium decays yeah you guys look at me + + + align:start position:0% +uranium decays yeah you guys look at me +Lisa blankly this is not that hard just + + align:start position:0% +Lisa blankly this is not that hard just + + + align:start position:0% +Lisa blankly this is not that hard just +one year eighty minute it's okay yeah + + align:start position:0% +one year eighty minute it's okay yeah + + + align:start position:0% +one year eighty minute it's okay yeah +all right so let's just write a + + align:start position:0% +all right so let's just write a + + + align:start position:0% +all right so let's just write a +plausible equation maybe it's DP DT + + align:start position:0% +plausible equation maybe it's DP DT + + + align:start position:0% +plausible equation maybe it's DP DT +where this is the probability that the + + align:start position:0% +where this is the probability that the + + + align:start position:0% +where this is the probability that the +uranium is in the box this might be + + align:start position:0% +uranium is in the box this might be + + + align:start position:0% +uranium is in the box this might be +probability divided by so what that + + align:start position:0% +probability divided by so what that + + + align:start position:0% +probability divided by so what that +would that be all right wait I guess we + + align:start position:0% +would that be all right wait I guess we + + + align:start position:0% +would that be all right wait I guess we +need a negative sign there so then the + + align:start position:0% +need a negative sign there so then the + + + align:start position:0% +need a negative sign there so then the +probability the solution of this would + + align:start position:0% +probability the solution of this would + + + align:start position:0% +probability the solution of this would +be that the probability that the uranium + + align:start position:0% +be that the probability that the uranium + + + align:start position:0% +be that the probability that the uranium +is still there it is gonna be equal to + + align:start position:0% +is still there it is gonna be equal to + + + align:start position:0% +is still there it is gonna be equal to +some initial probability either negative + + align:start position:0% +some initial probability either negative + + + align:start position:0% +some initial probability either negative +time or become great this is this look + + align:start position:0% +time or become great this is this look + + + align:start position:0% +time or become great this is this look +very reasonable + + align:start position:0% +very reasonable + + + align:start position:0% +very reasonable +you might seen this before yeah I mean + + align:start position:0% +you might seen this before yeah I mean + + + align:start position:0% +you might seen this before yeah I mean +II didn't think of this probability + + align:start position:0% +II didn't think of this probability + + + align:start position:0% +II didn't think of this probability +maybe you thought about it as number of + + align:start position:0% +maybe you thought about it as number of + + + align:start position:0% +maybe you thought about it as number of +uranium sandbox if I had written it as + + align:start position:0% +uranium sandbox if I had written it as + + + align:start position:0% +uranium sandbox if I had written it as +the number of uranium is equal to the + + align:start position:0% +the number of uranium is equal to the + + + align:start position:0% +the number of uranium is equal to the +original number of uranium's e to the + + align:start position:0% +original number of uranium's e to the + + + align:start position:0% +original number of uranium's e to the +negative T over tau you guys would have + + align:start position:0% +negative T over tau you guys would have + + + align:start position:0% +negative T over tau you guys would have +believed that right away right yeah okay + + align:start position:0% +believed that right away right yeah okay + + + align:start position:0% +believed that right away right yeah okay +so I guess maybe this is highlighting an + + align:start position:0% +so I guess maybe this is highlighting an + + + align:start position:0% +so I guess maybe this is highlighting an +issue here is that we're used to + + align:start position:0% +issue here is that we're used to + + + align:start position:0% +issue here is that we're used to +macroscopic thinking we're used to + + align:start position:0% +macroscopic thinking we're used to + + + align:start position:0% +macroscopic thinking we're used to +thinking of things this continuum right + + align:start position:0% +thinking of things this continuum right + + + align:start position:0% +thinking of things this continuum right +but if I only have one uranium there + + align:start position:0% +but if I only have one uranium there + + + align:start position:0% +but if I only have one uranium there +it's either there or it's not there it's + + align:start position:0% +it's either there or it's not there it's + + + align:start position:0% +it's either there or it's not there it's +1 or 0 it's so this the problem of this + + align:start position:0% +1 or 0 it's so this the problem of this + + + align:start position:0% +1 or 0 it's so this the problem of this +equation if you compute this it computes + + align:start position:0% +equation if you compute this it computes + + + align:start position:0% +equation if you compute this it computes +your you know irrational numbers + + align:start position:0% +your you know irrational numbers + + + align:start position:0% +your you know irrational numbers +fractional numbers as the number of + + align:start position:0% +fractional numbers as the number of + + + align:start position:0% +fractional numbers as the number of +uranium's but of course the number + + align:start position:0% +uranium's but of course the number + + + align:start position:0% +uranium's but of course the number +uranium is is just either it's integers + + align:start position:0% +uranium is is just either it's integers + + + align:start position:0% +uranium is is just either it's integers +right there's one uranium atom of this + + align:start position:0% +right there's one uranium atom of this + + + align:start position:0% +right there's one uranium atom of this +two or this 3 so this equation is not + + align:start position:0% +two or this 3 so this equation is not + + + align:start position:0% +two or this 3 so this equation is not +right all right this is incorrect so + + align:start position:0% +right all right this is incorrect so + + + align:start position:0% +right all right this is incorrect so +that was you learned in high school + + align:start position:0% +that was you learned in high school + + + align:start position:0% +that was you learned in high school +right that equation but that's not right + + align:start position:0% +right that equation but that's not right + + + align:start position:0% +right that equation but that's not right +so this is really the correct equation + + align:start position:0% +so this is really the correct equation + + + align:start position:0% +so this is really the correct equation +that the probability they have some + + align:start position:0% +that the probability they have some + + + align:start position:0% +that the probability they have some +memory uranium's does something + + align:start position:0% +memory uranium's does something + + + align:start position:0% +memory uranium's does something +you know if all this works for one year + + align:start position:0% +you know if all this works for one year + + + align:start position:0% +you know if all this works for one year +one atom anyway alright so that's the + + align:start position:0% +one atom anyway alright so that's the + + + align:start position:0% +one atom anyway alright so that's the +equation for one so this is probability + + align:start position:0% +equation for one so this is probability + + + align:start position:0% +equation for one so this is probability +I have one uranium if there's initial + + align:start position:0% +I have one uranium if there's initial + + + align:start position:0% +I have one uranium if there's initial +probability there's one your aim in the + + align:start position:0% +probability there's one your aim in the + + + align:start position:0% +probability there's one your aim in the +box which is basically my case will be + + align:start position:0% +box which is basically my case will be + + + align:start position:0% +box which is basically my case will be +one I know I put one in there + + align:start position:0% +one I know I put one in there + + + align:start position:0% +one I know I put one in there +right and that's just the case the + + align:start position:0% +right and that's just the case the + + + align:start position:0% +right and that's just the case the +probability decays but it doesn't mean + + align:start position:0% +probability decays but it doesn't mean + + + align:start position:0% +probability decays but it doesn't mean +the uranium decay so it means when I did + + align:start position:0% +the uranium decay so it means when I did + + + align:start position:0% +the uranium decay so it means when I did +if I do the experiment wants here I have + + align:start position:0% +if I do the experiment wants here I have + + + align:start position:0% +if I do the experiment wants here I have +the uranium the probability of the + + align:start position:0% +the uranium the probability of the + + + align:start position:0% +the uranium the probability of the +uranium is a simple exponential decay I + + align:start position:0% +uranium is a simple exponential decay I + + + align:start position:0% +uranium is a simple exponential decay I +know I had to uranium out of there when + + align:start position:0% +know I had to uranium out of there when + + + align:start position:0% +know I had to uranium out of there when +I first put it there and in later times + + align:start position:0% +I first put it there and in later times + + + align:start position:0% +I first put it there and in later times +it's going away + + align:start position:0% +it's going away + + + align:start position:0% +it's going away +right because longer longer times more + + align:start position:0% +right because longer longer times more + + + align:start position:0% +right because longer longer times more +more likelihood efficient now they + + align:start position:0% +more likelihood efficient now they + + + align:start position:0% +more likelihood efficient now they +actually do this to make a by a million + + align:start position:0% +actually do this to make a by a million + + + align:start position:0% +actually do this to make a by a million +boxes and put a million uranium atoms + + align:start position:0% +boxes and put a million uranium atoms + + + align:start position:0% +boxes and put a million uranium atoms +one in each one to start with and then I + + align:start position:0% +one in each one to start with and then I + + + align:start position:0% +one in each one to start with and then I +just keep coming back once a while and + + align:start position:0% +just keep coming back once a while and + + + align:start position:0% +just keep coming back once a while and +checking what I'll see is that initially + + align:start position:0% +checking what I'll see is that initially + + + align:start position:0% +checking what I'll see is that initially +I had number uranium's initially I had a + + align:start position:0% +I had number uranium's initially I had a + + + align:start position:0% +I had number uranium's initially I had a +million uranium atoms and for some time + + align:start position:0% +million uranium atoms and for some time + + + align:start position:0% +million uranium atoms and for some time +period I still had a million and then + + align:start position:0% +period I still had a million and then + + + align:start position:0% +period I still had a million and then +something happened and one of them went + + align:start position:0% +something happened and one of them went + + + align:start position:0% +something happened and one of them went +away because one of was envisioned turn + + align:start position:0% +away because one of was envisioned turn + + + align:start position:0% +away because one of was envisioned turn +into lead or whatever they turn into all + + align:start position:0% +into lead or whatever they turn into all + + + align:start position:0% +into lead or whatever they turn into all +right and so now I had a million minus + + align:start position:0% +right and so now I had a million minus + + + align:start position:0% +right and so now I had a million minus +one your any of said I live for a while + + align:start position:0% +one your any of said I live for a while + + + align:start position:0% +one your any of said I live for a while +and then maybe another one went away and + + align:start position:0% +and then maybe another one went away and + + + align:start position:0% +and then maybe another one went away and +then this time another one went away + + align:start position:0% +then this time another one went away + + + align:start position:0% +then this time another one went away +that time it lasted longer right this is + + align:start position:0% +that time it lasted longer right this is + + + align:start position:0% +that time it lasted longer right this is +what you really expect to observe this + + align:start position:0% +what you really expect to observe this + + + align:start position:0% +what you really expect to observe this +okay and so this is sampling from that + + align:start position:0% +okay and so this is sampling from that + + + align:start position:0% +okay and so this is sampling from that +probability distribution give you does + + align:start position:0% +probability distribution give you does + + + align:start position:0% +probability distribution give you does +it make sense + + align:start position:0% +it make sense + + + align:start position:0% +it make sense +yeah so I'm sampling a million times + + align:start position:0% +yeah so I'm sampling a million times + + + align:start position:0% +yeah so I'm sampling a million times +seven million boxes this is probably + + align:start position:0% +seven million boxes this is probably + + + align:start position:0% +seven million boxes this is probably +tribution for one box and so I'm able to + + align:start position:0% +tribution for one box and so I'm able to + + + align:start position:0% +tribution for one box and so I'm able to +figure this out okay + + align:start position:0% + + + + align:start position:0% + +all right so we'd like to write + + align:start position:0% +all right so we'd like to write + + + align:start position:0% +all right so we'd like to write +equations like this for more complicated + + align:start position:0% +equations like this for more complicated + + + align:start position:0% +equations like this for more complicated +systems but you'll still go have the + + align:start position:0% +systems but you'll still go have the + + + align:start position:0% +systems but you'll still go have the +same confusion that the probabilities is + + align:start position:0% +same confusion that the probabilities is + + + align:start position:0% +same confusion that the probabilities is +going to be a continuous variable and + + align:start position:0% +going to be a continuous variable and + + + align:start position:0% +going to be a continuous variable and +it's gonna behave in ways that seem + + align:start position:0% +it's gonna behave in ways that seem + + + align:start position:0% +it's gonna behave in ways that seem +perfectly sensible to you but then every + + align:start position:0% +perfectly sensible to you but then every + + + align:start position:0% +perfectly sensible to you but then every +time you do the experiment different + + align:start position:0% +time you do the experiment different + + + align:start position:0% +time you do the experiment different +things will happen in time because you + + align:start position:0% +things will happen in time because you + + + align:start position:0% +things will happen in time because you +have something that's a time varying + + align:start position:0% +have something that's a time varying + + + align:start position:0% +have something that's a time varying +probability and each time you sample + + align:start position:0% +probability and each time you sample + + + align:start position:0% +probability and each time you sample +from the probably solution every time + + align:start position:0% +from the probably solution every time + + + align:start position:0% +from the probably solution every time +you do the experiment it's like a + + align:start position:0% +you do the experiment it's like a + + + align:start position:0% +you do the experiment it's like a +particular instance of sampling from + + align:start position:0% +particular instance of sampling from + + + align:start position:0% +particular instance of sampling from +that probability tribution and you might + + align:start position:0% +that probability tribution and you might + + + align:start position:0% +that probability tribution and you might +get you might get that there's you know + + align:start position:0% +get you might get that there's you know + + + align:start position:0% +get you might get that there's you know +87 uranium atoms left you might get that + + align:start position:0% +87 uranium atoms left you might get that + + + align:start position:0% +87 uranium atoms left you might get that +there's 93 and it's it's not because of + + align:start position:0% +there's 93 and it's it's not because of + + + align:start position:0% +there's 93 and it's it's not because of +your measurement error it's because the + + align:start position:0% +your measurement error it's because the + + + align:start position:0% +your measurement error it's because the +the intrinsic system it has its own + + align:start position:0% +the intrinsic system it has its own + + + align:start position:0% +the intrinsic system it has its own +randomness to it right you know you look + + align:start position:0% +randomness to it right you know you look + + + align:start position:0% +randomness to it right you know you look +at one uranium atom some of uranium + + align:start position:0% +at one uranium atom some of uranium + + + align:start position:0% +at one uranium atom some of uranium +atoms live for a million years and some + + align:start position:0% +atoms live for a million years and some + + + align:start position:0% +atoms live for a million years and some +uranium atoms might decayed in the next + + align:start position:0% +uranium atoms might decayed in the next + + + align:start position:0% +uranium atoms might decayed in the next +second right and you have no idea when + + align:start position:0% +second right and you have no idea when + + + align:start position:0% +second right and you have no idea when +they're gonna decay all you know is + + align:start position:0% +they're gonna decay all you know is + + + align:start position:0% +they're gonna decay all you know is +statistically on the average uranium is + + align:start position:0% +statistically on the average uranium is + + + align:start position:0% +statistically on the average uranium is +decay with a certain half-life which is + + align:start position:0% +decay with a certain half-life which is + + + align:start position:0% +decay with a certain half-life which is +pretty long all right all right just + + align:start position:0% +pretty long all right all right just + + + align:start position:0% +pretty long all right all right just +totally obvious + + align:start position:0% +totally obvious + + + align:start position:0% +totally obvious +I kept here there's this like totally + + align:start position:0% +I kept here there's this like totally + + + align:start position:0% +I kept here there's this like totally +obvious are totally confusing it's very + + align:start position:0% +obvious are totally confusing it's very + + + align:start position:0% +obvious are totally confusing it's very +funny with you guys are your expressions + + align:start position:0% +funny with you guys are your expressions + + + align:start position:0% +funny with you guys are your expressions +totally obvious until we confusing has + + align:start position:0% +totally obvious until we confusing has + + + align:start position:0% +totally obvious until we confusing has +the same blank expression can somebody + + align:start position:0% +the same blank expression can somebody + + + align:start position:0% +the same blank expression can somebody +ask a question maybe that would help us + + align:start position:0% +ask a question maybe that would help us + + + align:start position:0% +ask a question maybe that would help us +do this is okay all right this is a guy + + align:start position:0% +do this is okay all right this is a guy + + + align:start position:0% +do this is okay all right this is a guy +the second all right so a totally + + align:start position:0% +the second all right so a totally + + + align:start position:0% +the second all right so a totally +obvious good hard to tell sometimes + + align:start position:0% +obvious good hard to tell sometimes + + + align:start position:0% +obvious good hard to tell sometimes +all right so Joe Scott were some + + align:start position:0% +all right so Joe Scott were some + + + align:start position:0% +all right so Joe Scott were some +brilliant notes try to explain how to do + + align:start position:0% +brilliant notes try to explain how to do + + + align:start position:0% +brilliant notes try to explain how to do +this for chemical kinetics okay so you + + align:start position:0% +this for chemical kinetics okay so you + + + align:start position:0% +this for chemical kinetics okay so you +should definitely read them there in the + + align:start position:0% +should definitely read them there in the + + + align:start position:0% +should definitely read them there in the +posted under the materials general + + align:start position:0% +posted under the materials general + + + align:start position:0% +posted under the materials general +section stochastic chemical kinetics + + align:start position:0% +section stochastic chemical kinetics + + + align:start position:0% +section stochastic chemical kinetics +nice 20 page long thing don't like that + + align:start position:0% +nice 20 page long thing don't like that + + + align:start position:0% +nice 20 page long thing don't like that +it's definitely worthwhile to read it he + + align:start position:0% +it's definitely worthwhile to read it he + + + align:start position:0% +it's definitely worthwhile to read it he +was very nice to write very clear note + + align:start position:0% +was very nice to write very clear note + + + align:start position:0% +was very nice to write very clear note +so I'll try to explain his notes in + + align:start position:0% +so I'll try to explain his notes in + + + align:start position:0% +so I'll try to explain his notes in +expertly in a short period of time I + + align:start position:0% +expertly in a short period of time I + + + align:start position:0% +expertly in a short period of time I +strongly recommend your video so the + + align:start position:0% +strongly recommend your video so the + + + align:start position:0% +strongly recommend your video so the +idea is that the chemical kinetic + + align:start position:0% +idea is that the chemical kinetic + + + align:start position:0% +idea is that the chemical kinetic +equation do you guys have all used are + + align:start position:0% +equation do you guys have all used are + + + align:start position:0% +equation do you guys have all used are +also incorrect right just like this is + + align:start position:0% +also incorrect right just like this is + + + align:start position:0% +also incorrect right just like this is +incorrect right + + align:start position:0% +incorrect right + + + align:start position:0% +incorrect right +because this is assuming that something + + align:start position:0% +because this is assuming that something + + + align:start position:0% +because this is assuming that something +that's really a discrete variable is a + + align:start position:0% +that's really a discrete variable is a + + + align:start position:0% +that's really a discrete variable is a +continuous variable and we do this all + + align:start position:0% +continuous variable and we do this all + + + align:start position:0% +continuous variable and we do this all +the time right + + align:start position:0% +the time right + + + align:start position:0% +the time right +we know that material is made of atoms + + align:start position:0% +we know that material is made of atoms + + + align:start position:0% +we know that material is made of atoms +and so when you measure a mass in a + + align:start position:0% +and so when you measure a mass in a + + + align:start position:0% +and so when you measure a mass in a +certain volume there only can be certain + + align:start position:0% +certain volume there only can be certain + + + align:start position:0% +certain volume there only can be certain +discrete values but we always ignore + + align:start position:0% +discrete values but we always ignore + + + align:start position:0% +discrete values but we always ignore +that and we always treat mass as a + + align:start position:0% +that and we always treat mass as a + + + align:start position:0% +that and we always treat mass as a +continuous variable right so you have + + align:start position:0% +continuous variable right so you have + + + align:start position:0% +continuous variable right so you have +some flow some amount of liquid and you + + align:start position:0% +some flow some amount of liquid and you + + + align:start position:0% +some flow some amount of liquid and you +have some amount of mass so it could be + + align:start position:0% +have some amount of mass so it could be + + + align:start position:0% +have some amount of mass so it could be +any number and we treat D you know D M + + align:start position:0% +any number and we treat D you know D M + + + align:start position:0% +any number and we treat D you know D M +DT or things with DM DX D Rho DX we + + align:start position:0% +DT or things with DM DX D Rho DX we + + + align:start position:0% +DT or things with DM DX D Rho DX we +wrote those down as if everything's + + align:start position:0% +wrote those down as if everything's + + + align:start position:0% +wrote those down as if everything's +perfectly continuous variables and + + align:start position:0% +perfectly continuous variables and + + + align:start position:0% +perfectly continuous variables and +that's because that in a lot of systems + + align:start position:0% +that's because that in a lot of systems + + + align:start position:0% +that's because that in a lot of systems +we have we have so many atoms and we + + align:start position:0% +we have we have so many atoms and we + + + align:start position:0% +we have we have so many atoms and we +can't measure that well any way that we + + align:start position:0% +can't measure that well any way that we + + + align:start position:0% +can't measure that well any way that we +can tell if we were missing one or two + + align:start position:0% +can tell if we were missing one or two + + + align:start position:0% +can tell if we were missing one or two +atoms whether we end up with an extra + + align:start position:0% +atoms whether we end up with an extra + + + align:start position:0% +atoms whether we end up with an extra +half an atom in our equations or not + + align:start position:0% +half an atom in our equations or not + + + align:start position:0% +half an atom in our equations or not +makes no difference because we're not + + align:start position:0% +makes no difference because we're not + + + align:start position:0% +makes no difference because we're not +that precise right so we don't worry + + align:start position:0% +that precise right so we don't worry + + + align:start position:0% +that precise right so we don't worry +about so we use continuum equations + + align:start position:0% +about so we use continuum equations + + + align:start position:0% +about so we use continuum equations +everywhere in but in many cases what we + + align:start position:0% +everywhere in but in many cases what we + + + align:start position:0% +everywhere in but in many cases what we +really should be using our continuous + + align:start position:0% +really should be using our continuous + + + align:start position:0% +really should be using our continuous +equations for probabilities and and then + + align:start position:0% +equations for probabilities and and then + + + align:start position:0% +equations for probabilities and and then +as I'm trying to show you how you do it + + align:start position:0% +as I'm trying to show you how you do it + + + align:start position:0% +as I'm trying to show you how you do it +for chemical kinetics in a minute I'd + + align:start position:0% +for chemical kinetics in a minute I'd + + + align:start position:0% +for chemical kinetics in a minute I'd +say that this is super fundamental + + align:start position:0% +say that this is super fundamental + + + align:start position:0% +say that this is super fundamental +actually so quantum mechanics says that + + align:start position:0% +actually so quantum mechanics says that + + + align:start position:0% +actually so quantum mechanics says that +everything is wave functions which is + + align:start position:0% +everything is wave functions which is + + + align:start position:0% +everything is wave functions which is +actually like the square root of a + + align:start position:0% +actually like the square root of a + + + align:start position:0% +actually like the square root of a +probability density and the real + + align:start position:0% +probability density and the real + + + align:start position:0% +probability density and the real +equations are are probably really + + align:start position:0% +equations are are probably really + + + align:start position:0% +equations are are probably really +probability densities and so that's the + + align:start position:0% +probability densities and so that's the + + + align:start position:0% +probability densities and so that's the +real fundamental equations really + + align:start position:0% +real fundamental equations really + + + align:start position:0% +real fundamental equations really +everything is probabilities and when you + + align:start position:0% +everything is probabilities and when you + + + align:start position:0% +everything is probabilities and when you +make an experiment you're just sampling + + align:start position:0% +make an experiment you're just sampling + + + align:start position:0% +make an experiment you're just sampling +from the probability and all our + + align:start position:0% +from the probability and all our + + + align:start position:0% +from the probability and all our +continuing equations are like + + align:start position:0% +continuing equations are like + + + align:start position:0% +continuing equations are like +approximations they're only valid in + + align:start position:0% +approximations they're only valid in + + + align:start position:0% +approximations they're only valid in +like a large large number of atoms limit + + align:start position:0% +like a large large number of atoms limit + + + align:start position:0% +like a large large number of atoms limit +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so just I know this takes it may be a + + align:start position:0% +so just I know this takes it may be a + + + align:start position:0% +so just I know this takes it may be a +change of thought because you're so used + + align:start position:0% +change of thought because you're so used + + + align:start position:0% +change of thought because you're so used +to this continual equations you start to + + align:start position:0% +to this continual equations you start to + + + align:start position:0% +to this continual equations you start to +believe they're really true right right + + align:start position:0% +believe they're really true right right + + + align:start position:0% +believe they're really true right right +if you probably use them a lot and you + + align:start position:0% +if you probably use them a lot and you + + + align:start position:0% +if you probably use them a lot and you +start to feel like you love those + + align:start position:0% +start to feel like you love those + + + align:start position:0% +start to feel like you love those +equations or your favorite equations you + + align:start position:0% +equations or your favorite equations you + + + align:start position:0% +equations or your favorite equations you +know you have a relationship for them + + align:start position:0% +know you have a relationship for them + + + align:start position:0% +know you have a relationship for them +something you might hate some of you + + align:start position:0% +something you might hate some of you + + + align:start position:0% +something you might hate some of you +love but at least you have a strong + + align:start position:0% +love but at least you have a strong + + + align:start position:0% +love but at least you have a strong +connection with them and you find out + + align:start position:0% +connection with them and you find out + + + align:start position:0% +connection with them and you find out +that the actually they're not even + + align:start position:0% +that the actually they're not even + + + align:start position:0% +that the actually they're not even +related to the real equation so the real + + align:start position:0% +related to the real equation so the real + + + align:start position:0% +related to the real equation so the real +equations are actually some different + + align:start position:0% +equations are actually some different + + + align:start position:0% +equations are actually some different +Isis be very annoying but it's true and + + align:start position:0% +Isis be very annoying but it's true and + + + align:start position:0% +Isis be very annoying but it's true and +when you get to smaller and smaller + + align:start position:0% +when you get to smaller and smaller + + + align:start position:0% +when you get to smaller and smaller +systems that have fewer and fewer + + align:start position:0% +systems that have fewer and fewer + + + align:start position:0% +systems that have fewer and fewer +molecules in them + + align:start position:0% +molecules in them + + + align:start position:0% +molecules in them +then you get more and more sensitive to + + align:start position:0% +then you get more and more sensitive to + + + align:start position:0% +then you get more and more sensitive to +the fact that the regular equations are + + align:start position:0% +the fact that the regular equations are + + + align:start position:0% +the fact that the regular equations are +incorrect and the this comes up a lot in + + align:start position:0% +incorrect and the this comes up a lot in + + + align:start position:0% +incorrect and the this comes up a lot in +small systems so that many of you + + align:start position:0% +small systems so that many of you + + + align:start position:0% +small systems so that many of you +probably will do research that has to do + + align:start position:0% +probably will do research that has to do + + + align:start position:0% +probably will do research that has to do +with biology inside in biology they're + + align:start position:0% +with biology inside in biology they're + + + align:start position:0% +with biology inside in biology they're +cells inside cells there's like + + align:start position:0% +cells inside cells there's like + + + align:start position:0% +cells inside cells there's like +subcellular structures inside those sub + + align:start position:0% +subcellular structures inside those sub + + + align:start position:0% +subcellular structures inside those sub +cellular structures there's not very + + align:start position:0% +cellular structures there's not very + + + align:start position:0% +cellular structures there's not very +many molecules and so you often are at + + align:start position:0% +many molecules and so you often are at + + + align:start position:0% +many molecules and so you often are at +the limit where you know you have like + + align:start position:0% +the limit where you know you have like + + + align:start position:0% +the limit where you know you have like +one molecule of a certain type inside + + align:start position:0% +one molecule of a certain type inside + + + align:start position:0% +one molecule of a certain type inside +this you know in mitochondria or + + align:start position:0% +this you know in mitochondria or + + + align:start position:0% +this you know in mitochondria or +something and that's it and so you + + align:start position:0% +something and that's it and so you + + + align:start position:0% +something and that's it and so you +wouldn't expect a continuum equations to + + align:start position:0% +wouldn't expect a continuum equations to + + + align:start position:0% +wouldn't expect a continuum equations to +work and and in fact there's a big field + + align:start position:0% +work and and in fact there's a big field + + + align:start position:0% +work and and in fact there's a big field +many people research doing here called + + align:start position:0% +many people research doing here called + + + align:start position:0% +many people research doing here called +single molecule spectroscopy where you + + align:start position:0% +single molecule spectroscopy where you + + + align:start position:0% +single molecule spectroscopy where you +can watch and you know measure the + + align:start position:0% +can watch and you know measure the + + + align:start position:0% +can watch and you know measure the +motion of one DNA molecule or something + + align:start position:0% +motion of one DNA molecule or something + + + align:start position:0% +motion of one DNA molecule or something +like that and so you really see the + + align:start position:0% +like that and so you really see the + + + align:start position:0% +like that and so you really see the +individual molecules and and the effects + + align:start position:0% +individual molecules and and the effects + + + align:start position:0% +individual molecules and and the effects +of the individuality of the molecules + + align:start position:0% +of the individuality of the molecules + + + align:start position:0% +of the individuality of the molecules +and this is not only true in biology for + + align:start position:0% +and this is not only true in biology for + + + align:start position:0% +and this is not only true in biology for +a long time there's a field called + + align:start position:0% +a long time there's a field called + + + align:start position:0% +a long time there's a field called +emulsion polymerization you guys ever + + align:start position:0% +emulsion polymerization you guys ever + + + align:start position:0% +emulsion polymerization you guys ever +hear this so like all the paint on the + + align:start position:0% +hear this so like all the paint on the + + + align:start position:0% +hear this so like all the paint on the +walls here is made by that process where + + align:start position:0% +walls here is made by that process where + + + align:start position:0% +walls here is made by that process where +they polymerize methyl methacrylate they + + align:start position:0% +they polymerize methyl methacrylate they + + + align:start position:0% +they polymerize methyl methacrylate they +want to make the little beads of + + align:start position:0% +want to make the little beads of + + + align:start position:0% +want to make the little beads of +polymers as have a small dispersion as + + align:start position:0% +polymers as have a small dispersion as + + + align:start position:0% +polymers as have a small dispersion as +possible to make them all the molecules + + align:start position:0% +possible to make them all the molecules + + + align:start position:0% +possible to make them all the molecules +the same so what they do is they make a + + align:start position:0% +the same so what they do is they make a + + + align:start position:0% +the same so what they do is they make a +colloidal suspension draw a little + + align:start position:0% +colloidal suspension draw a little + + + align:start position:0% +colloidal suspension draw a little +picture so they have a reactor they make + + align:start position:0% +picture so they have a reactor they make + + + align:start position:0% +picture so they have a reactor they make +little bubbles of the monomer that are + + align:start position:0% +little bubbles of the monomer that are + + + align:start position:0% +little bubbles of the monomer that are +suspended in some solvent and inside + + align:start position:0% +suspended in some solvent and inside + + + align:start position:0% +suspended in some solvent and inside +each of these bubbles because the way + + align:start position:0% +each of these bubbles because the way + + + align:start position:0% +each of these bubbles because the way +they make them they're all about the + + align:start position:0% +they make them they're all about the + + + align:start position:0% +they make them they're all about the +same size so they all have a lot of + + align:start position:0% +same size so they all have a lot of + + + align:start position:0% +same size so they all have a lot of +bubbles all about the same size and then + + align:start position:0% +bubbles all about the same size and then + + + align:start position:0% +bubbles all about the same size and then +they polymerize and they polymerize each + + align:start position:0% +they polymerize and they polymerize each + + + align:start position:0% +they polymerize and they polymerize each +them and they polymerize and basically + + align:start position:0% +them and they polymerize and basically + + + align:start position:0% +them and they polymerize and basically +all the material that's they are + + align:start position:0% +all the material that's they are + + + align:start position:0% +all the material that's they are +polymerizes into one molecule how do + + align:start position:0% +polymerizes into one molecule how do + + + align:start position:0% +polymerizes into one molecule how do +they make that happen is that they + + align:start position:0% +they make that happen is that they + + + align:start position:0% +they make that happen is that they +introduce say a free radical and one + + align:start position:0% +introduce say a free radical and one + + + align:start position:0% +introduce say a free radical and one +free radical gets into one these mala in + + align:start position:0% +free radical gets into one these mala in + + + align:start position:0% +free radical gets into one these mala in +these bubbles and it complies the whole + + align:start position:0% +these bubbles and it complies the whole + + + align:start position:0% +these bubbles and it complies the whole +thing because the reactions are radical + + align:start position:0% +thing because the reactions are radical + + + align:start position:0% +thing because the reactions are radical +plus monomer gets to a you know + + align:start position:0% +plus monomer gets to a you know + + + align:start position:0% +plus monomer gets to a you know +copolymer bigger polymer polymer radical + + align:start position:0% +copolymer bigger polymer polymer radical + + + align:start position:0% +copolymer bigger polymer polymer radical +size in goes to polymer radical size n + + align:start position:0% +size in goes to polymer radical size n + + + align:start position:0% +size in goes to polymer radical size n +plus one that's the polymerization + + align:start position:0% +plus one that's the polymerization + + + align:start position:0% +plus one that's the polymerization +reaction now normally + + align:start position:0% +reaction now normally + + + align:start position:0% +reaction now normally +if you did this in the bulk there'd be a + + align:start position:0% +if you did this in the bulk there'd be a + + + align:start position:0% +if you did this in the bulk there'd be a +lot of radicals and some of these guys + + align:start position:0% +lot of radicals and some of these guys + + + align:start position:0% +lot of radicals and some of these guys +would react with each other and the rack + + align:start position:0% +would react with each other and the rack + + + align:start position:0% +would react with each other and the rack +will be gone because the two radicals + + align:start position:0% +will be gone because the two radicals + + + align:start position:0% +will be gone because the two radicals +would react make a new chemical bond and + + align:start position:0% +would react make a new chemical bond and + + + align:start position:0% +would react make a new chemical bond and +this process would stop and so this + + align:start position:0% +this process would stop and so this + + + align:start position:0% +this process would stop and so this +gives a big dispersion in the size of + + align:start position:0% +gives a big dispersion in the size of + + + align:start position:0% +gives a big dispersion in the size of +the polymer change again so to beat this + + align:start position:0% +the polymer change again so to beat this + + + align:start position:0% +the polymer change again so to beat this +they do a molten polymerization and they + + align:start position:0% +they do a molten polymerization and they + + + align:start position:0% +they do a molten polymerization and they +make the number of radicals so small + + align:start position:0% +make the number of radicals so small + + + align:start position:0% +make the number of radicals so small +that statistically at a time and these + + align:start position:0% +that statistically at a time and these + + + align:start position:0% +that statistically at a time and these +droplets either has 0 or 1 of radicals + + align:start position:0% +droplets either has 0 or 1 of radicals + + + align:start position:0% +droplets either has 0 or 1 of radicals +in it and and there's not during the + + align:start position:0% +in it and and there's not during the + + + align:start position:0% +in it and and there's not during the +time it does the polymerization there's + + align:start position:0% +time it does the polymerization there's + + + align:start position:0% +time it does the polymerization there's +not enough time for a second radical to + + align:start position:0% +not enough time for a second radical to + + + align:start position:0% +not enough time for a second radical to +come in so it's only got one radical so + + align:start position:0% +come in so it's only got one radical so + + + align:start position:0% +come in so it's only got one radical so +that one radical is gonna eat up every + + align:start position:0% +that one radical is gonna eat up every + + + align:start position:0% +that one radical is gonna eat up every +single monomer molecule and the whole + + align:start position:0% +single monomer molecule and the whole + + + align:start position:0% +single monomer molecule and the whole +thing and so it's gonna make a giant + + align:start position:0% +thing and so it's gonna make a giant + + + align:start position:0% +thing and so it's gonna make a giant +polymer that's the whole size of the + + align:start position:0% +polymer that's the whole size of the + + + align:start position:0% +polymer that's the whole size of the +emulsion if you if you made the drops + + align:start position:0% +emulsion if you if you made the drops + + + align:start position:0% +emulsion if you if you made the drops +too big you get two radicals in there + + align:start position:0% +too big you get two radicals in there + + + align:start position:0% +too big you get two radicals in there +you get something that's happening and + + align:start position:0% +you get something that's happening and + + + align:start position:0% +you get something that's happening and +you get a dispersion so this is a + + align:start position:0% +you get a dispersion so this is a + + + align:start position:0% +you get a dispersion so this is a +emulsion polymerization + + align:start position:0% + + + + align:start position:0% + +all right so cells have small little + + align:start position:0% +all right so cells have small little + + + align:start position:0% +all right so cells have small little +volumes colloids and emulsions have + + align:start position:0% +volumes colloids and emulsions have + + + align:start position:0% +volumes colloids and emulsions have +small little volumes they all have that + + align:start position:0% +small little volumes they all have that + + + align:start position:0% +small little volumes they all have that +the sum of the molecules the important + + align:start position:0% +the sum of the molecules the important + + + align:start position:0% +the sum of the molecules the important +molecules are so have such low + + align:start position:0% +molecules are so have such low + + + align:start position:0% +molecules are so have such low +concentrations of ions are so small that + + align:start position:0% +concentrations of ions are so small that + + + align:start position:0% +concentrations of ions are so small that +the concentration times the volume is + + align:start position:0% +the concentration times the volume is + + + align:start position:0% +the concentration times the volume is +less than 1 or about 1 so that's for + + align:start position:0% +less than 1 or about 1 so that's for + + + align:start position:0% +less than 1 or about 1 so that's for +like you know your your copies of DNA + + align:start position:0% +like you know your your copies of DNA + + + align:start position:0% +like you know your your copies of DNA +and you in your cells there's the same + + align:start position:0% +and you in your cells there's the same + + + align:start position:0% +and you in your cells there's the same +kind of thing for radicals free radicals + + align:start position:0% +kind of thing for radicals free radicals + + + align:start position:0% +kind of thing for radicals free radicals +and a polymerization system and the + + align:start position:0% +and a polymerization system and the + + + align:start position:0% +and a polymerization system and the +Civil Code things could happen with like + + align:start position:0% +Civil Code things could happen with like + + + align:start position:0% +Civil Code things could happen with like +explosions + + align:start position:0% +explosions + + + align:start position:0% +explosions +different kinds of rare events you might + + align:start position:0% +different kinds of rare events you might + + + align:start position:0% +different kinds of rare events you might +have a very small number of some really + + align:start position:0% +have a very small number of some really + + + align:start position:0% +have a very small number of some really +important molecule and then whether or + + align:start position:0% +important molecule and then whether or + + + align:start position:0% +important molecule and then whether or +not you have one or not is really + + align:start position:0% +not you have one or not is really + + + align:start position:0% +not you have one or not is really +important ok all right so we want to + + align:start position:0% +important ok all right so we want to + + + align:start position:0% +important ok all right so we want to +model those kinds of systems we have to + + align:start position:0% +model those kinds of systems we have to + + + align:start position:0% +model those kinds of systems we have to +worry about the graininess so we want to + + align:start position:0% +worry about the graininess so we want to + + + align:start position:0% +worry about the graininess so we want to +write down what the equation is for DP + + align:start position:0% +write down what the equation is for DP + + + align:start position:0% +write down what the equation is for DP +DT so firstly I think what is P let's do + + align:start position:0% +DT so firstly I think what is P let's do + + + align:start position:0% +DT so firstly I think what is P let's do +a case + + align:start position:0% + + + + align:start position:0% + +where have the reaction of a plus B goes + + align:start position:0% +where have the reaction of a plus B goes + + + align:start position:0% +where have the reaction of a plus B goes +to C okay suppose this the only reaction + + align:start position:0% +to C okay suppose this the only reaction + + + align:start position:0% +to C okay suppose this the only reaction +at camp in our system the only molecules + + align:start position:0% +at camp in our system the only molecules + + + align:start position:0% +at camp in our system the only molecules +we have our system or A's B's and C's + + align:start position:0% +we have our system or A's B's and C's + + + align:start position:0% +we have our system or A's B's and C's +and so our probability distribution or + + align:start position:0% +and so our probability distribution or + + + align:start position:0% +and so our probability distribution or +probably we want to know is how many A's + + align:start position:0% +probably we want to know is how many A's + + + align:start position:0% +probably we want to know is how many A's +how many bees how many C's do we have in + + align:start position:0% +how many bees how many C's do we have in + + + align:start position:0% +how many bees how many C's do we have in +our system okay so that's that's a + + align:start position:0% +our system okay so that's that's a + + + align:start position:0% +our system okay so that's that's a +probability we're interested to know we + + align:start position:0% +probability we're interested to know we + + + align:start position:0% +probability we're interested to know we +could have five A's to B's and zero C's + + align:start position:0% +could have five A's to B's and zero C's + + + align:start position:0% +could have five A's to B's and zero C's +we could have 3a is seven B's elevenses + + align:start position:0% +we could have 3a is seven B's elevenses + + + align:start position:0% +we could have 3a is seven B's elevenses +who knows all right different numbers + + align:start position:0% +who knows all right different numbers + + + align:start position:0% +who knows all right different numbers +like that if he gets out to be ten to + + align:start position:0% +like that if he gets out to be ten to + + + align:start position:0% +like that if he gets out to be ten to +the 23rd then there's no point you don't + + align:start position:0% +the 23rd then there's no point you don't + + + align:start position:0% +the 23rd then there's no point you don't +have to do this because you can just go + + align:start position:0% +have to do this because you can just go + + + align:start position:0% +have to do this because you can just go +back to your continuum equations right + + align:start position:0% +back to your continuum equations right + + + align:start position:0% +back to your continuum equations right +but if you have five or three or two or + + align:start position:0% +but if you have five or three or two or + + + align:start position:0% +but if you have five or three or two or +one or zero then you really need to + + align:start position:0% +one or zero then you really need to + + + align:start position:0% +one or zero then you really need to +worry about the graininess so you want + + align:start position:0% +worry about the graininess so you want + + + align:start position:0% +worry about the graininess so you want +to write down an equation so here's the + + align:start position:0% +to write down an equation so here's the + + + align:start position:0% +to write down an equation so here's the +probability of n a and D and C and it's + + align:start position:0% +probability of n a and D and C and it's + + + align:start position:0% +probability of n a and D and C and it's +going to equal two reactions which + + align:start position:0% +going to equal two reactions which + + + align:start position:0% +going to equal two reactions which +consume if I'm in the state that has + + align:start position:0% +consume if I'm in the state that has + + + align:start position:0% +consume if I'm in the state that has +certain number of A's B's and C's and I + + align:start position:0% +certain number of A's B's and C's and I + + + align:start position:0% +certain number of A's B's and C's and I +can react away so we have reactions for + + align:start position:0% +can react away so we have reactions for + + + align:start position:0% +can react away so we have reactions for +example I'm in this state and a plus B + + align:start position:0% +example I'm in this state and a plus B + + + align:start position:0% +example I'm in this state and a plus B +could react with each other and and will + + align:start position:0% +could react with each other and and will + + + align:start position:0% +could react with each other and and will +react away so I'll have a some reaction + + align:start position:0% +react away so I'll have a some reaction + + + align:start position:0% +react away so I'll have a some reaction +I'm gonna write it K but we'll come back + + align:start position:0% +I'm gonna write it K but we'll come back + + + align:start position:0% +I'm gonna write it K but we'll come back +to what this really means exactly in a + + align:start position:0% +to what this really means exactly in a + + + align:start position:0% +to what this really means exactly in a +minute so this is the K for a plus B + + align:start position:0% +minute so this is the K for a plus B + + + align:start position:0% +minute so this is the K for a plus B +going to C and we think that this is + + align:start position:0% +going to C and we think that this is + + + align:start position:0% +going to C and we think that this is +going to scale with a number of A's and + + align:start position:0% +going to scale with a number of A's and + + + align:start position:0% +going to scale with a number of A's and +the number of bees have gotten right and + + align:start position:0% +the number of bees have gotten right and + + + align:start position:0% +the number of bees have gotten right and +this depends on the probability that I + + align:start position:0% +this depends on the probability that I + + + align:start position:0% +this depends on the probability that I +have ABC okay so if I if I'm if I'm in + + align:start position:0% +have ABC okay so if I if I'm if I'm in + + + align:start position:0% +have ABC okay so if I if I'm if I'm in +this state with n A's and B's and C's + + align:start position:0% +this state with n A's and B's and C's + + + align:start position:0% +this state with n A's and B's and C's +that probability is going to go down + + align:start position:0% +that probability is going to go down + + + align:start position:0% +that probability is going to go down +because the A's and B's can react with + + align:start position:0% +because the A's and B's can react with + + + align:start position:0% +because the A's and B's can react with +each other right + + align:start position:0% +each other right + + + align:start position:0% +each other right +now on the other hand I have plus the + + align:start position:0% +now on the other hand I have plus the + + + align:start position:0% +now on the other hand I have plus the +same K + + align:start position:0% + + + + align:start position:0% + +and this is gonna be n a-prime and + + align:start position:0% +and this is gonna be n a-prime and + + + align:start position:0% +and this is gonna be n a-prime and +b-prime if I have some other state that + + align:start position:0% +b-prime if I have some other state that + + + align:start position:0% +b-prime if I have some other state that +can react so that it makes this state + + align:start position:0% +can react so that it makes this state + + + align:start position:0% +can react so that it makes this state +then I'll get a plus sign because the + + align:start position:0% +then I'll get a plus sign because the + + + align:start position:0% +then I'll get a plus sign because the +probability of the state would increase + + align:start position:0% +probability of the state would increase + + + align:start position:0% +probability of the state would increase +so for example if na prime is equal to + + align:start position:0% +so for example if na prime is equal to + + + align:start position:0% +so for example if na prime is equal to +na plus 1 and B prime is equal to NB + + align:start position:0% +na plus 1 and B prime is equal to NB + + + align:start position:0% +na plus 1 and B prime is equal to NB +plus 1 and then C prime is equal to and + + align:start position:0% +plus 1 and then C prime is equal to and + + + align:start position:0% +plus 1 and then C prime is equal to and +C minus 1 then that state can react by + + align:start position:0% +C minus 1 then that state can react by + + + align:start position:0% +C minus 1 then that state can react by +one of these days and one of these B's + + align:start position:0% +one of these days and one of these B's + + + align:start position:0% +one of these days and one of these B's +combining together to make a C that will + + align:start position:0% +combining together to make a C that will + + + align:start position:0% +combining together to make a C that will +get me to this exact state here + + align:start position:0% +get me to this exact state here + + + align:start position:0% +get me to this exact state here +does it make sense all right so that's + + align:start position:0% +does it make sense all right so that's + + + align:start position:0% +does it make sense all right so that's +the master equation if I have a system + + align:start position:0% +the master equation if I have a system + + + align:start position:0% +the master equation if I have a system +that can only do the irreversible + + align:start position:0% +that can only do the irreversible + + + align:start position:0% +that can only do the irreversible +reaction a plus B goes to C so the only + + align:start position:0% +reaction a plus B goes to C so the only + + + align:start position:0% +reaction a plus B goes to C so the only +I can go away because I probability + + align:start position:0% +I can go away because I probability + + + align:start position:0% +I can go away because I probability +density of this is probably the state + + align:start position:0% +density of this is probably the state + + + align:start position:0% +density of this is probably the state +can reduce because that reaction occurs + + align:start position:0% +can reduce because that reaction occurs + + + align:start position:0% +can reduce because that reaction occurs +starting from this state and the + + align:start position:0% +starting from this state and the + + + align:start position:0% +starting from this state and the +probably this state can increase because + + align:start position:0% +probably this state can increase because + + + align:start position:0% +probably this state can increase because +I started from this other stay here the + + align:start position:0% +I started from this other stay here the + + + align:start position:0% +I started from this other stay here the +special stay here and that would make + + align:start position:0% +special stay here and that would make + + + align:start position:0% +special stay here and that would make +the state of interest + + align:start position:0% +the state of interest + + + align:start position:0% +the state of interest +all right and so I have equation this + + align:start position:0% +all right and so I have equation this + + + align:start position:0% +all right and so I have equation this +equation over and over again for every + + align:start position:0% +equation over and over again for every + + + align:start position:0% +equation over and over again for every +possible value of n a and B H and C this + + align:start position:0% +possible value of n a and B H and C this + + + align:start position:0% +possible value of n a and B H and C this +is ok now I have to actually remember + + align:start position:0% +is ok now I have to actually remember + + + align:start position:0% +is ok now I have to actually remember +for chemical kinetics that whenever you + + align:start position:0% +for chemical kinetics that whenever you + + + align:start position:0% +for chemical kinetics that whenever you +have a forward reaction you also have + + align:start position:0% +have a forward reaction you also have + + + align:start position:0% +have a forward reaction you also have +the reverse reaction so there's actually + + align:start position:0% +the reverse reaction so there's actually + + + align:start position:0% +the reverse reaction so there's actually +a couple more terms so now I have + + align:start position:0% +a couple more terms so now I have + + + align:start position:0% +a couple more terms so now I have +another lost term this is C goes to a + + align:start position:0% +another lost term this is C goes to a + + + align:start position:0% +another lost term this is C goes to a +plus B this is going to tend on the + + align:start position:0% +plus B this is going to tend on the + + + align:start position:0% +plus B this is going to tend on the +number of C's and that's a P of n a and + + align:start position:0% +number of C's and that's a P of n a and + + + align:start position:0% +number of C's and that's a P of n a and +B and C and then I have another source + + align:start position:0% +B and C and then I have another source + + + align:start position:0% +B and C and then I have another source +term + + align:start position:0% + + + + align:start position:0% + +and this is where I start from state + + align:start position:0% +and this is where I start from state + + + align:start position:0% +and this is where I start from state +with one more C okay so this set of + + align:start position:0% +with one more C okay so this set of + + + align:start position:0% +with one more C okay so this set of +equations is called the kinetic master + + align:start position:0% +equations is called the kinetic master + + + align:start position:0% +equations is called the kinetic master +equation and this is the equation that + + align:start position:0% +equation and this is the equation that + + + align:start position:0% +equation and this is the equation that +describes a real system so this is the + + align:start position:0% +describes a real system so this is the + + + align:start position:0% +describes a real system so this is the +real probability of finding the system + + align:start position:0% +real probability of finding the system + + + align:start position:0% +real probability of finding the system +with any number of A's B's and C's and I + + align:start position:0% +with any number of A's B's and C's and I + + + align:start position:0% +with any number of A's B's and C's and I +have an equation like this for every + + align:start position:0% +have an equation like this for every + + + align:start position:0% +have an equation like this for every +different possible number of A's number + + align:start position:0% +different possible number of A's number + + + align:start position:0% +different possible number of A's number +of BS and number sees all right and it's + + align:start position:0% +of BS and number sees all right and it's + + + align:start position:0% +of BS and number sees all right and it's +not bad as an equation goes it's a + + align:start position:0% +not bad as an equation goes it's a + + + align:start position:0% +not bad as an equation goes it's a +linear differential equation because it + + align:start position:0% +linear differential equation because it + + + align:start position:0% +linear differential equation because it +it's linear in peas right there's just + + align:start position:0% +it's linear in peas right there's just + + + align:start position:0% +it's linear in peas right there's just +first everything's first power in P so + + align:start position:0% +first everything's first power in P so + + + align:start position:0% +first everything's first power in P so +in general I can rewrite this as DP DT + + align:start position:0% +in general I can rewrite this as DP DT + + + align:start position:0% +in general I can rewrite this as DP DT +is equal to some matrix times me right + + align:start position:0% +is equal to some matrix times me right + + + align:start position:0% +is equal to some matrix times me right +and the matrix entries are these pre + + align:start position:0% +and the matrix entries are these pre + + + align:start position:0% +and the matrix entries are these pre +factors things like this sorry these are + + align:start position:0% +factors things like this sorry these are + + + align:start position:0% +factors things like this sorry these are +the different elements in the matrix am + + align:start position:0% + + + + align:start position:0% + +alright yeah + + align:start position:0% +alright yeah + + + align:start position:0% +alright yeah +so you should go ahead and be able to + + align:start position:0% +so you should go ahead and be able to + + + align:start position:0% +so you should go ahead and be able to +write any kinetic equation system + + align:start position:0% +write any kinetic equation system + + + align:start position:0% +write any kinetic equation system +rewrite it in this form if you want it's + + align:start position:0% +rewrite it in this form if you want it's + + + align:start position:0% +rewrite it in this form if you want it's +called the kinetic master equation + + align:start position:0% +called the kinetic master equation + + + align:start position:0% +called the kinetic master equation +[Applause] + + align:start position:0% + + + + align:start position:0% + +alright now if I do an experiment like I + + align:start position:0% +alright now if I do an experiment like I + + + align:start position:0% +alright now if I do an experiment like I +talked about with uranium ore I put one + + align:start position:0% +talked about with uranium ore I put one + + + align:start position:0% +talked about with uranium ore I put one +uranium atom in there and all your any + + align:start position:0% +uranium atom in there and all your any + + + align:start position:0% +uranium atom in there and all your any +items can react to do is fall apart to + + align:start position:0% +items can react to do is fall apart to + + + align:start position:0% +items can react to do is fall apart to +lead plus neutrons or whatever the heck + + align:start position:0% +lead plus neutrons or whatever the heck + + + align:start position:0% +lead plus neutrons or whatever the heck +they fall apart to so I can write down + + align:start position:0% +they fall apart to so I can write down + + + align:start position:0% +they fall apart to so I can write down +there's like one reaction that uranium + + align:start position:0% +there's like one reaction that uranium + + + align:start position:0% +there's like one reaction that uranium +nuclei do and so I could write it out + + align:start position:0% +nuclei do and so I could write it out + + + align:start position:0% +nuclei do and so I could write it out +and it'll just be a little something + + align:start position:0% +and it'll just be a little something + + + align:start position:0% +and it'll just be a little something +like this and there's a question of work + + align:start position:0% +like this and there's a question of work + + + align:start position:0% +like this and there's a question of work +you know for a case where I put one + + align:start position:0% +you know for a case where I put one + + + align:start position:0% +you know for a case where I put one +uranium atom there to begin with I could + + align:start position:0% +uranium atom there to begin with I could + + + align:start position:0% +uranium atom there to begin with I could +do the case where I put two uranium + + align:start position:0% +do the case where I put two uranium + + + align:start position:0% +do the case where I put two uranium +atoms in there to begin with I could + + align:start position:0% +atoms in there to begin with I could + + + align:start position:0% +atoms in there to begin with I could +write this down said alright okay now if + + align:start position:0% +write this down said alright okay now if + + + align:start position:0% +write this down said alright okay now if +I had a case where I had 27 a s14 B's + + align:start position:0% +I had a case where I had 27 a s14 B's + + + align:start position:0% +I had a case where I had 27 a s14 B's +and 33 C's to start with then you can + + align:start position:0% +and 33 C's to start with then you can + + + align:start position:0% +and 33 C's to start with then you can +see that the number of possibilities + + align:start position:0% +see that the number of possibilities + + + align:start position:0% +see that the number of possibilities +here might get pretty large except to + + align:start position:0% +here might get pretty large except to + + + align:start position:0% +here might get pretty large except to +consider well I could lose one a and + + align:start position:0% +consider well I could lose one a and + + + align:start position:0% +consider well I could lose one a and +there's one B and get one more C but + + align:start position:0% +there's one B and get one more C but + + + align:start position:0% +there's one B and get one more C but +then I'll have an equation for this term + + align:start position:0% +then I'll have an equation for this term + + + align:start position:0% +then I'll have an equation for this term +which will look just like this but it'll + + align:start position:0% +which will look just like this but it'll + + + align:start position:0% +which will look just like this but it'll +go to ones I have lost two days and two + + align:start position:0% +go to ones I have lost two days and two + + + align:start position:0% +go to ones I have lost two days and two +B's and gained two c's and then all the + + align:start position:0% +B's and gained two c's and then all the + + + align:start position:0% +B's and gained two c's and then all the +way down until I get down to one of the + + align:start position:0% +way down until I get down to one of the + + + align:start position:0% +way down until I get down to one of the +ends to be 0 + + align:start position:0% +ends to be 0 + + + align:start position:0% +ends to be 0 +right and so it could be quite a lot of + + align:start position:0% +right and so it could be quite a lot of + + + align:start position:0% +right and so it could be quite a lot of +possible equations right so the + + align:start position:0% +possible equations right so the + + + align:start position:0% +possible equations right so the +dimension the length of the the vector P + + align:start position:0% +dimension the length of the the vector P + + + align:start position:0% +dimension the length of the the vector P +might get really long right so you know + + align:start position:0% +might get really long right so you know + + + align:start position:0% +might get really long right so you know +the the length of P is something like + + align:start position:0% +the the length of P is something like + + + align:start position:0% +the the length of P is something like +the max number of A's max number of bees + + align:start position:0% +the max number of A's max number of bees + + + align:start position:0% +the max number of A's max number of bees +max number of C's all right so if I have + + align:start position:0% +max number of C's all right so if I have + + + align:start position:0% +max number of C's all right so if I have +you know I allow I consider systems with + + align:start position:0% +you know I allow I consider systems with + + + align:start position:0% +you know I allow I consider systems with +up to 10 days 10 B's and 10 C's then + + align:start position:0% +up to 10 days 10 B's and 10 C's then + + + align:start position:0% +up to 10 days 10 B's and 10 C's then +this is a thousand P is the length of + + align:start position:0% +this is a thousand P is the length of + + + align:start position:0% +this is a thousand P is the length of +approximately and it might be less than + + align:start position:0% +approximately and it might be less than + + + align:start position:0% +approximately and it might be less than +that because may + + align:start position:0% +that because may + + + align:start position:0% +that because may +some of them some pretty clear states I + + align:start position:0% +some of them some pretty clear states I + + + align:start position:0% +some of them some pretty clear states I +can't get to all right submits less than + + align:start position:0% +can't get to all right submits less than + + + align:start position:0% +can't get to all right submits less than +a thousand but something like a thousand + + align:start position:0% +a thousand but something like a thousand + + + align:start position:0% +a thousand but something like a thousand +on the other hand if I allow up to a + + align:start position:0% +on the other hand if I allow up to a + + + align:start position:0% +on the other hand if I allow up to a +million A's a million bees and a million + + align:start position:0% +million A's a million bees and a million + + + align:start position:0% +million A's a million bees and a million +sees then I have like 10 to the 18th + + align:start position:0% +sees then I have like 10 to the 18th + + + align:start position:0% +sees then I have like 10 to the 18th +lent the P so P gets pretty long pretty + + align:start position:0% +lent the P so P gets pretty long pretty + + + align:start position:0% +lent the P so P gets pretty long pretty +fast when the number of possible states + + align:start position:0% +fast when the number of possible states + + + align:start position:0% +fast when the number of possible states +gives up all right so now it's linear + + align:start position:0% +gives up all right so now it's linear + + + align:start position:0% +gives up all right so now it's linear +though and it's linear and this is + + align:start position:0% +though and it's linear and this is + + + align:start position:0% +though and it's linear and this is +constant coefficients and so this is + + align:start position:0% +constant coefficients and so this is + + + align:start position:0% +constant coefficients and so this is +really not as sparse so this is really + + align:start position:0% +really not as sparse so this is really + + + align:start position:0% +really not as sparse so this is really +it's not that bad and in fact professor + + align:start position:0% +it's not that bad and in fact professor + + + align:start position:0% +it's not that bad and in fact professor +Barton's group has worked on these kind + + align:start position:0% +Barton's group has worked on these kind + + + align:start position:0% +Barton's group has worked on these kind +of problems and he has a saw or that can + + align:start position:0% +of problems and he has a saw or that can + + + align:start position:0% +of problems and he has a saw or that can +work with pH dimension up to 200 million + + align:start position:0% +work with pH dimension up to 200 million + + + align:start position:0% +work with pH dimension up to 200 million +so if you can keep the number of states + + align:start position:0% +so if you can keep the number of states + + + align:start position:0% +so if you can keep the number of states +200 million or less you can actually + + align:start position:0% +200 million or less you can actually + + + align:start position:0% +200 million or less you can actually +solve this exactly now some of this + + align:start position:0% +solve this exactly now some of this + + + align:start position:0% +solve this exactly now some of this +exactly is really good because then you + + align:start position:0% +exactly is really good because then you + + + align:start position:0% +exactly is really good because then you +actually have the exact probability of + + align:start position:0% +actually have the exact probability of + + + align:start position:0% +actually have the exact probability of +any observable measurement that you + + align:start position:0% +any observable measurement that you + + + align:start position:0% +any observable measurement that you +would possibly make at any time all + + align:start position:0% +would possibly make at any time all + + + align:start position:0% +would possibly make at any time all +computed okay + + align:start position:0% +computed okay + + + align:start position:0% +computed okay +so that's really great but as I just + + align:start position:0% +so that's really great but as I just + + + align:start position:0% +so that's really great but as I just +pointed out if I make these numbers like + + align:start position:0% +pointed out if I make these numbers like + + + align:start position:0% +pointed out if I make these numbers like +10 to the 6 10 to the 6 and 10 to 6 this + + align:start position:0% +10 to the 6 10 to the 6 and 10 to 6 this + + + align:start position:0% +10 to the 6 10 to the 6 and 10 to 6 this +is like 10 to the 18 that's a lot bigger + + align:start position:0% +is like 10 to the 18 that's a lot bigger + + + align:start position:0% +is like 10 to the 18 that's a lot bigger +than 200 million and so professor Barton + + align:start position:0% +than 200 million and so professor Barton + + + align:start position:0% +than 200 million and so professor Barton +is numerical methods are going to pop + + align:start position:0% +is numerical methods are going to pop + + + align:start position:0% +is numerical methods are going to pop +out at some point and not gonna work for + + align:start position:0% +out at some point and not gonna work for + + + align:start position:0% +out at some point and not gonna work for +you anymore so there's a limited number + + align:start position:0% +you anymore so there's a limited number + + + align:start position:0% +you anymore so there's a limited number +of problems you can do so if your + + align:start position:0% +of problems you can do so if your + + + align:start position:0% +of problems you can do so if your +problem is small enough you just solve + + align:start position:0% +problem is small enough you just solve + + + align:start position:0% +problem is small enough you just solve +this for really small ones you can just + + align:start position:0% +this for really small ones you can just + + + align:start position:0% +this for really small ones you can just +solve this with OD for 5 or OD 1 5s but + + align:start position:0% +solve this with OD for 5 or OD 1 5s but + + + align:start position:0% +solve this with OD for 5 or OD 1 5s but +because it's linear there's special + + align:start position:0% +because it's linear there's special + + + align:start position:0% +because it's linear there's special +solution methods I know you remember + + align:start position:0% +solution methods I know you remember + + + align:start position:0% +solution methods I know you remember +solutions of linear equations like this + + align:start position:0% +solutions of linear equations like this + + + align:start position:0% +solutions of linear equations like this +you you can relate them to the + + align:start position:0% +you you can relate them to the + + + align:start position:0% +you you can relate them to the +eigenvectors and eigenvalues of m and so + + align:start position:0% +eigenvectors and eigenvalues of m and so + + + align:start position:0% +eigenvectors and eigenvalues of m and so +you can do that's one way to do it and + + align:start position:0% +you can do that's one way to do it and + + + align:start position:0% +you can do that's one way to do it and +then there's special methods you can do + + align:start position:0% +then there's special methods you can do + + + align:start position:0% +then there's special methods you can do +talk to Professor Barton if it's sparse + + align:start position:0% +talk to Professor Barton if it's sparse + + + align:start position:0% +talk to Professor Barton if it's sparse +and certain kinds of properties you can + + align:start position:0% +and certain kinds of properties you can + + + align:start position:0% +and certain kinds of properties you can +make this really you can make quite + + align:start position:0% +make this really you can make quite + + + align:start position:0% +make this really you can make quite +large systems up to you know 10 to the + + align:start position:0% +large systems up to you know 10 to the + + + align:start position:0% +large systems up to you know 10 to the +8th kind of size if you get a system + + align:start position:0% +8th kind of size if you get a system + + + align:start position:0% +8th kind of size if you get a system +with more than 10 to 8 possible States + + align:start position:0% +with more than 10 to 8 possible States + + + align:start position:0% +with more than 10 to 8 possible States +that means more than 10 to the 8th + + align:start position:0% +that means more than 10 to the 8th + + + align:start position:0% +that means more than 10 to the 8th +possible things could be observed you + + align:start position:0% +possible things could be observed you + + + align:start position:0% +possible things could be observed you +know or could be the result of the + + align:start position:0% +know or could be the result of the + + + align:start position:0% +know or could be the result of the +experiment could be we have more than 10 + + align:start position:0% +experiment could be we have more than 10 + + + align:start position:0% +experiment could be we have more than 10 +to the 8th possibilities then this is + + align:start position:0% +to the 8th possibilities then this is + + + align:start position:0% +to the 8th possibilities then this is +you're not gonna be able solve it this + + align:start position:0% +you're not gonna be able solve it this + + + align:start position:0% +you're not gonna be able solve it this +way and so then we're gonna have to use + + align:start position:0% +way and so then we're gonna have to use + + + align:start position:0% +way and so then we're gonna have to use +a stochastic solid solution method to + + align:start position:0% +a stochastic solid solution method to + + + align:start position:0% +a stochastic solid solution method to +try to figure that to do so + + align:start position:0% +try to figure that to do so + + + align:start position:0% +try to figure that to do so +going to try to sample from P of T so I + + align:start position:0% +going to try to sample from P of T so I + + + align:start position:0% +going to try to sample from P of T so I +guess I should comment again I wrote it + + align:start position:0% +guess I should comment again I wrote it + + + align:start position:0% +guess I should comment again I wrote it +this way but this thing P is definitely + + align:start position:0% +this way but this thing P is definitely + + + align:start position:0% +this way but this thing P is definitely +depends on time so it's you'll have a + + align:start position:0% +depends on time so it's you'll have a + + + align:start position:0% +depends on time so it's you'll have a +different p for every time yeah + + align:start position:0% + + + + align:start position:0% + +yeah maybe maybe I'd do better too I can + + align:start position:0% +yeah maybe maybe I'd do better too I can + + + align:start position:0% +yeah maybe maybe I'd do better too I can +substitute in here said right yeah + + align:start position:0% +substitute in here said right yeah + + + align:start position:0% +substitute in here said right yeah +there's a key idea is that chemical + + align:start position:0% +there's a key idea is that chemical + + + align:start position:0% +there's a key idea is that chemical +kinetics only does one step at a time so + + align:start position:0% +kinetics only does one step at a time so + + + align:start position:0% +kinetics only does one step at a time so +if you have a reaction like this at any + + align:start position:0% +if you have a reaction like this at any + + + align:start position:0% +if you have a reaction like this at any +instant the probability that two + + align:start position:0% +instant the probability that two + + + align:start position:0% +instant the probability that two +reactions are happening exactly the same + + align:start position:0% +reactions are happening exactly the same + + + align:start position:0% +reactions are happening exactly the same +instant is negligible so that at any + + align:start position:0% +instant is negligible so that at any + + + align:start position:0% +instant is negligible so that at any +instant you're only changing the numbers + + align:start position:0% +instant you're only changing the numbers + + + align:start position:0% +instant you're only changing the numbers +of the atoms by one one unit yeah may I + + align:start position:0% +of the atoms by one one unit yeah may I + + + align:start position:0% +of the atoms by one one unit yeah may I +get this backwards in a plus 1 plus 1 + + align:start position:0% +get this backwards in a plus 1 plus 1 + + + align:start position:0% +get this backwards in a plus 1 plus 1 +minus 1 minus 1 minus 1 plus 1 I think I + + align:start position:0% +minus 1 minus 1 minus 1 plus 1 I think I + + + align:start position:0% +minus 1 minus 1 minus 1 plus 1 I think I +got I think this is right so this is for + + align:start position:0% +got I think this is right so this is for + + + align:start position:0% +got I think this is right so this is for +the forward reaction that always reduces + + align:start position:0% +the forward reaction that always reduces + + + align:start position:0% +the forward reaction that always reduces +the number of A's and B's and this is + + align:start position:0% +the number of A's and B's and this is + + + align:start position:0% +the number of A's and B's and this is +the reverse reaction that always + + align:start position:0% +the reverse reaction that always + + + align:start position:0% +the reverse reaction that always +increases that and so I think you + + align:start position:0% +increases that and so I think you + + + align:start position:0% +increases that and so I think you +generally get like this you always get + + align:start position:0% +generally get like this you always get + + + align:start position:0% +generally get like this you always get +for any reaction you'll have four terms + + align:start position:0% +for any reaction you'll have four terms + + + align:start position:0% +for any reaction you'll have four terms +so the forward and reverse starting for + + align:start position:0% +so the forward and reverse starting for + + + align:start position:0% +so the forward and reverse starting for +the initial state and the forward and + + align:start position:0% +the initial state and the forward and + + + align:start position:0% +the initial state and the forward and +reverse that make your state alright and + + align:start position:0% +reverse that make your state alright and + + + align:start position:0% +reverse that make your state alright and +then if you have more reactions you have + + align:start position:0% +then if you have more reactions you have + + + align:start position:0% +then if you have more reactions you have +system we have a lot more reactions + + align:start position:0% +system we have a lot more reactions + + + align:start position:0% +system we have a lot more reactions +maybe you have seed you can just + + align:start position:0% +maybe you have seed you can just + + + align:start position:0% +maybe you have seed you can just +decompose into bees or something + + align:start position:0% +decompose into bees or something + + + align:start position:0% +decompose into bees or something +different reactions then you'd have a + + align:start position:0% +different reactions then you'd have a + + + align:start position:0% +different reactions then you'd have a +sum like this with terms like this from + + align:start position:0% +sum like this with terms like this from + + + align:start position:0% +sum like this with terms like this from +every reaction and you go through all + + align:start position:0% +every reaction and you go through all + + + align:start position:0% +every reaction and you go through all +your list of all your actions alright I + + align:start position:0% +your list of all your actions alright I + + + align:start position:0% +your list of all your actions alright I +guess there's there's one funny thing I + + align:start position:0% +guess there's there's one funny thing I + + + align:start position:0% +guess there's there's one funny thing I +should point out to you about this it's + + align:start position:0% +should point out to you about this it's + + + align:start position:0% +should point out to you about this it's +very important for this emulsion + + align:start position:0% +very important for this emulsion + + + align:start position:0% +very important for this emulsion +polymerization case is that if you have + + align:start position:0% +polymerization case is that if you have + + + align:start position:0% +polymerization case is that if you have +a reaction of the type a plus + + align:start position:0% +a reaction of the type a plus + + + align:start position:0% +a reaction of the type a plus +a ghost I don't know okay that might be + + align:start position:0% +a ghost I don't know okay that might be + + + align:start position:0% +a ghost I don't know okay that might be +a reaction you could have that when I + + align:start position:0% +a reaction you could have that when I + + + align:start position:0% +a reaction you could have that when I +write down the equation if I only have + + align:start position:0% +write down the equation if I only have + + + align:start position:0% +write down the equation if I only have +one a in my sample this probability of + + align:start position:0% +one a in my sample this probability of + + + align:start position:0% +one a in my sample this probability of +this of this happening is zero right + + align:start position:0% +this of this happening is zero right + + + align:start position:0% +this of this happening is zero right +because I need two ways for this to + + align:start position:0% +because I need two ways for this to + + + align:start position:0% +because I need two ways for this to +happen + + align:start position:0% +happen + + + align:start position:0% +happen +so really the equation for this case is + + align:start position:0% +so really the equation for this case is + + + align:start position:0% +so really the equation for this case is +na times na minus one so it's K a plus a + + align:start position:0% +na times na minus one so it's K a plus a + + + align:start position:0% +na times na minus one so it's K a plus a +goes to B times n a times anyway alright + + align:start position:0% +goes to B times n a times anyway alright + + + align:start position:0% +goes to B times n a times anyway alright +and this is crucial for like the + + align:start position:0% +and this is crucial for like the + + + align:start position:0% +and this is crucial for like the +emulsion polymerization case does the + + align:start position:0% +emulsion polymerization case does the + + + align:start position:0% +emulsion polymerization case does the +fact that I have don't have a second one + + align:start position:0% +fact that I have don't have a second one + + + align:start position:0% +fact that I have don't have a second one +is really important all right + + align:start position:0% +is really important all right + + + align:start position:0% +is really important all right +otherwise I was miss compute that this + + align:start position:0% +otherwise I was miss compute that this + + + align:start position:0% +otherwise I was miss compute that this +radical could react with itself and + + align:start position:0% +radical could react with itself and + + + align:start position:0% +radical could react with itself and +terminate itself which is not true is + + align:start position:0% +terminate itself which is not true is + + + align:start position:0% +terminate itself which is not true is +that right um I commented that these k's + + align:start position:0% +that right um I commented that these k's + + + align:start position:0% +that right um I commented that these k's +are a little bit odd so if you remember + + align:start position:0% +are a little bit odd so if you remember + + + align:start position:0% +are a little bit odd so if you remember +if you have a k4 a unimolecular reaction + + align:start position:0% +if you have a k4 a unimolecular reaction + + + align:start position:0% +if you have a k4 a unimolecular reaction +like C goes to a plus B what units would + + align:start position:0% +like C goes to a plus B what units would + + + align:start position:0% +like C goes to a plus B what units would +it have what are use for in regular + + align:start position:0% +it have what are use for in regular + + + align:start position:0% +it have what are use for in regular +kinetics right inverse seconds right so + + align:start position:0% +kinetics right inverse seconds right so + + + align:start position:0% +kinetics right inverse seconds right so +you'd normally say this thing has units + + align:start position:0% +you'd normally say this thing has units + + + align:start position:0% +you'd normally say this thing has units +of inverse seconds and that works fine + + align:start position:0% +of inverse seconds and that works fine + + + align:start position:0% +of inverse seconds and that works fine +here right because I have DP DT and its + + align:start position:0% +here right because I have DP DT and its + + + align:start position:0% +here right because I have DP DT and its +inverse seconds times P so it's fine + + align:start position:0% +inverse seconds times P so it's fine + + + align:start position:0% +inverse seconds times P so it's fine +however this guy to make the unit's + + align:start position:0% +however this guy to make the unit's + + + align:start position:0% +however this guy to make the unit's +workout still has to also be inverse + + align:start position:0% +workout still has to also be inverse + + + align:start position:0% +workout still has to also be inverse +seconds but that's not normally what you + + align:start position:0% +seconds but that's not normally what you + + + align:start position:0% +seconds but that's not normally what you +would have for a by molecular reaction + + align:start position:0% +would have for a by molecular reaction + + + align:start position:0% +would have for a by molecular reaction +right and the other thing to watch out + + align:start position:0% +right and the other thing to watch out + + + align:start position:0% +right and the other thing to watch out +for here is that I have ends but + + align:start position:0% +for here is that I have ends but + + + align:start position:0% +for here is that I have ends but +normally you would write them with + + align:start position:0% +normally you would write them with + + + align:start position:0% +normally you would write them with +concentrations right you'd have the + + align:start position:0% +concentrations right you'd have the + + + align:start position:0% +concentrations right you'd have the +content you would write something like K + + align:start position:0% +content you would write something like K + + + align:start position:0% +content you would write something like K +times the concentration of C it's a + + align:start position:0% +times the concentration of C it's a + + + align:start position:0% +times the concentration of C it's a +normal way you write your equations to + + align:start position:0% +normal way you write your equations to + + + align:start position:0% +normal way you write your equations to +the rate equations but this is not the + + align:start position:0% +the rate equations but this is not the + + + align:start position:0% +the rate equations but this is not the +same right this is n this is unitless + + align:start position:0% +same right this is n this is unitless + + + align:start position:0% +same right this is n this is unitless +now it turns out in this case actually + + align:start position:0% +now it turns out in this case actually + + + align:start position:0% +now it turns out in this case actually +you can use the exactly the same case + + align:start position:0% +you can use the exactly the same case + + + align:start position:0% +you can use the exactly the same case +okay and it works but for the + + align:start position:0% +okay and it works but for the + + + align:start position:0% +okay and it works but for the +biomolecular case it definitely does not + + align:start position:0% +biomolecular case it definitely does not + + + align:start position:0% +biomolecular case it definitely does not +work + + align:start position:0% +work + + + align:start position:0% +work +the units are wrong and also this + + align:start position:0% +the units are wrong and also this + + + align:start position:0% +the units are wrong and also this +concentration thing implies that we + + align:start position:0% +concentration thing implies that we + + + align:start position:0% +concentration thing implies that we +think the rate really has stable if you + + align:start position:0% +think the rate really has stable if you + + + align:start position:0% +think the rate really has stable if you +have ka KB I could rewrite this as K + + align:start position:0% +have ka KB I could rewrite this as K + + + align:start position:0% +have ka KB I could rewrite this as K +times n a over the volume and B over the + + align:start position:0% +times n a over the volume and B over the + + + align:start position:0% +times n a over the volume and B over the +volume said all right actually one thing + + align:start position:0% +volume said all right actually one thing + + + align:start position:0% +volume said all right actually one thing +I should warn you about that usually + + align:start position:0% +I should warn you about that usually + + + align:start position:0% +I should warn you about that usually +write this I mold per liter so I factors + + align:start position:0% +write this I mold per liter so I factors + + + align:start position:0% +write this I mold per liter so I factors +a 10 to the 23rd between this and this + + align:start position:0% +a 10 to the 23rd between this and this + + + align:start position:0% +a 10 to the 23rd between this and this +because these ends have got to be the + + align:start position:0% +because these ends have got to be the + + + align:start position:0% +because these ends have got to be the +individual molecules it's for us to work + + align:start position:0% +individual molecules it's for us to work + + + align:start position:0% +individual molecules it's for us to work +so what so watch out first of all + + align:start position:0% +so what so watch out first of all + + + align:start position:0% +so what so watch out first of all +there's a 10 to the 23rd somewhere in + + align:start position:0% +there's a 10 to the 23rd somewhere in + + + align:start position:0% +there's a 10 to the 23rd somewhere in +here I have a gathers number and then + + align:start position:0% +here I have a gathers number and then + + + align:start position:0% +here I have a gathers number and then +this is what how we would normally write + + align:start position:0% +this is what how we would normally write + + + align:start position:0% +this is what how we would normally write +it but this K has the wrong units for us + + align:start position:0% +it but this K has the wrong units for us + + + align:start position:0% +it but this K has the wrong units for us +here and so this this guy here is the + + align:start position:0% +here and so this this guy here is the + + + align:start position:0% +here and so this this guy here is the +normal K divided by the volume see + + align:start position:0% +normal K divided by the volume see + + + align:start position:0% +normal K divided by the volume see +that's right mate the other way around + + align:start position:0% +that's right mate the other way around + + + align:start position:0% +that's right mate the other way around +no this is no 1 K times above that's + + align:start position:0% +no this is no 1 K times above that's + + + align:start position:0% +no this is no 1 K times above that's +right so normally we would write the + + align:start position:0% +right so normally we would write the + + + align:start position:0% +right so normally we would write the +unit's k normal normal kinetics back row + + align:start position:0% + + + + align:start position:0% + +K for a plus B reactions the units are + + align:start position:0% +K for a plus B reactions the units are + + + align:start position:0% +K for a plus B reactions the units are +centimeters cubed per mole second and + + align:start position:0% +centimeters cubed per mole second and + + + align:start position:0% +centimeters cubed per mole second and +but we want them to be units of the new + + align:start position:0% +but we want them to be units of the new + + + align:start position:0% +but we want them to be units of the new +the new K it's got to be units of per + + align:start position:0% +the new K it's got to be units of per + + + align:start position:0% +the new K it's got to be units of per +second and so the new K is equal to the + + align:start position:0% +second and so the new K is equal to the + + + align:start position:0% +second and so the new K is equal to the +old K new old times fine it's all right + + align:start position:0% +old K new old times fine it's all right + + + align:start position:0% +old K new old times fine it's all right +no divide by the by let's write that + + align:start position:0% +no divide by the by let's write that + + + align:start position:0% +no divide by the by let's write that +first + + align:start position:0% +first + + + align:start position:0% +first +this is volume that yep + + align:start position:0% +this is volume that yep + + + align:start position:0% +this is volume that yep +seven ears cute Sandra's cute yeah I + + align:start position:0% +seven ears cute Sandra's cute yeah I + + + align:start position:0% +seven ears cute Sandra's cute yeah I +guess hold out good for a second so this + + align:start position:0% +guess hold out good for a second so this + + + align:start position:0% +guess hold out good for a second so this +is K per volume no I'm okay right and + + align:start position:0% +is K per volume no I'm okay right and + + + align:start position:0% +is K per volume no I'm okay right and +you may wonder well how come it's only + + align:start position:0% +you may wonder well how come it's only + + + align:start position:0% +you may wonder well how come it's only +volume to the first power + + align:start position:0% +volume to the first power + + + align:start position:0% +volume to the first power +before I had volume to the second power + + align:start position:0% +before I had volume to the second power + + + align:start position:0% +before I had volume to the second power +in the denominator and it's because I'm + + align:start position:0% +in the denominator and it's because I'm + + + align:start position:0% +in the denominator and it's because I'm +using ends up in the numerator and it's + + align:start position:0% +using ends up in the numerator and it's + + + align:start position:0% +using ends up in the numerator and it's +just like here I'm using ends instead of + + align:start position:0% +just like here I'm using ends instead of + + + align:start position:0% +just like here I'm using ends instead of +n over V so I've sort of multiplying + + align:start position:0% +n over V so I've sort of multiplying + + + align:start position:0% +n over V so I've sort of multiplying +through by be everywhere it's one way to + + align:start position:0% +through by be everywhere it's one way to + + + align:start position:0% +through by be everywhere it's one way to +look at all right no questions yet yeah + + align:start position:0% +look at all right no questions yet yeah + + + align:start position:0% +look at all right no questions yet yeah +uh yeah it's only the ten to the 23rd as + + align:start position:0% +uh yeah it's only the ten to the 23rd as + + + align:start position:0% +uh yeah it's only the ten to the 23rd as +well so there's gonna be navigators + + align:start position:0% +well so there's gonna be navigators + + + align:start position:0% +well so there's gonna be navigators +number and you'll tell me where the + + align:start position:0% +number and you'll tell me where the + + + align:start position:0% +number and you'll tell me where the +advertisers number goes but it's gotta + + align:start position:0% +advertisers number goes but it's gotta + + + align:start position:0% +advertisers number goes but it's gotta +be in there somewhere to get from Boston + + align:start position:0% +be in there somewhere to get from Boston + + + align:start position:0% +be in there somewhere to get from Boston +to Nagas + + align:start position:0% +to Nagas + + + align:start position:0% +to Nagas +so the numbers are a lot different yeah + + align:start position:0% + + + + align:start position:0% + +this is okay in this factor this n minus + + align:start position:0% +this is okay in this factor this n minus + + + align:start position:0% +this is okay in this factor this n minus +one thing again when these are + + align:start position:0% +one thing again when these are + + + align:start position:0% +one thing again when these are +macroscopic numbers like 10 to the 23rd + + align:start position:0% +macroscopic numbers like 10 to the 23rd + + + align:start position:0% +macroscopic numbers like 10 to the 23rd +this makes no difference right that's + + align:start position:0% +this makes no difference right that's + + + align:start position:0% +this makes no difference right that's +minus 1 so we can fit our data ignoring + + align:start position:0% +minus 1 so we can fit our data ignoring + + + align:start position:0% +minus 1 so we can fit our data ignoring +the one is 1 perfectly well the law of + + align:start position:0% +the one is 1 perfectly well the law of + + + align:start position:0% +the one is 1 perfectly well the law of +mass action that works fine so you never + + align:start position:0% +mass action that works fine so you never + + + align:start position:0% +mass action that works fine so you never +notice this unless you get down to where + + align:start position:0% +notice this unless you get down to where + + + align:start position:0% +notice this unless you get down to where +n is very small but this is actually + + align:start position:0% +n is very small but this is actually + + + align:start position:0% +n is very small but this is actually +this is actually the truth this is + + align:start position:0% +this is actually the truth this is + + + align:start position:0% +this is actually the truth this is +really what the correct equation is + + align:start position:0% + + + + align:start position:0% + +alright okay so so we now we have these + + align:start position:0% +alright okay so so we now we have these + + + align:start position:0% +alright okay so so we now we have these +the true equations for predicting the + + align:start position:0% +the true equations for predicting the + + + align:start position:0% +the true equations for predicting the +profile the probability distribution + + align:start position:0% +profile the probability distribution + + + align:start position:0% +profile the probability distribution +evolves in a reacting system by the way + + align:start position:0% +evolves in a reacting system by the way + + + align:start position:0% +evolves in a reacting system by the way +you can add transport in as well if you + + align:start position:0% +you can add transport in as well if you + + + align:start position:0% +you can add transport in as well if you +want so if you have control volumes and + + align:start position:0% +want so if you have control volumes and + + + align:start position:0% +want so if you have control volumes and +you know what formulas for the rate at + + align:start position:0% +you know what formulas for the rate at + + + align:start position:0% +you know what formulas for the rate at +which stuff is transported in and out of + + align:start position:0% +which stuff is transported in and out of + + + align:start position:0% +which stuff is transported in and out of +the control volume you can add those + + align:start position:0% +the control volume you can add those + + + align:start position:0% +the control volume you can add those +terms in as well and they will affect + + align:start position:0% +terms in as well and they will affect + + + align:start position:0% +terms in as well and they will affect +the probability distribution okay no + + align:start position:0% +the probability distribution okay no + + + align:start position:0% +the probability distribution okay no +problem you should be able to do the + + align:start position:0% +problem you should be able to do the + + + align:start position:0% +problem you should be able to do the +same conversion so just we converted the + + align:start position:0% +same conversion so just we converted the + + + align:start position:0% +same conversion so just we converted the +reaction equations + + align:start position:0% +reaction equations + + + align:start position:0% +reaction equations +you can write a similar thing once you + + align:start position:0% +you can write a similar thing once you + + + align:start position:0% +you can write a similar thing once you +can write the macroscopic transport + + align:start position:0% +can write the macroscopic transport + + + align:start position:0% +can write the macroscopic transport +equation you can figure out how you + + align:start position:0% +equation you can figure out how you + + + align:start position:0% +equation you can figure out how you +would reduce it down to a time constant + + align:start position:0% +would reduce it down to a time constant + + + align:start position:0% +would reduce it down to a time constant +for transport that would work for the + + align:start position:0% +for transport that would work for the + + + align:start position:0% +for transport that would work for the +for this microscopic version of + + align:start position:0% +for this microscopic version of + + + align:start position:0% +for this microscopic version of +equations so transport may actually + + align:start position:0% +equations so transport may actually + + + align:start position:0% +equations so transport may actually +grate the whole thing down that's the + + align:start position:0% +grate the whole thing down that's the + + + align:start position:0% +grate the whole thing down that's the +master equation that's the real solution + + align:start position:0% +master equation that's the real solution + + + align:start position:0% +master equation that's the real solution +the real equation and the problem is + + align:start position:0% +the real equation and the problem is + + + align:start position:0% +the real equation and the problem is +that the real equation oftentimes is too + + align:start position:0% +that the real equation oftentimes is too + + + align:start position:0% +that the real equation oftentimes is too +big because P scales up so so rapidly + + align:start position:0% +big because P scales up so so rapidly + + + align:start position:0% +big because P scales up so so rapidly +with the number of possible states + + align:start position:0% +with the number of possible states + + + align:start position:0% +with the number of possible states +so then wait to figure how we're going + + align:start position:0% +so then wait to figure how we're going + + + align:start position:0% +so then wait to figure how we're going +to solve it and the way to solve it is + + align:start position:0% +to solve it and the way to solve it is + + + align:start position:0% +to solve it and the way to solve it is +by called kinetic Montecarlo and this + + align:start position:0% +by called kinetic Montecarlo and this + + + align:start position:0% +by called kinetic Montecarlo and this +method was invented by a guy named John + + align:start position:0% +method was invented by a guy named John + + + align:start position:0% +method was invented by a guy named John +Gillespie and the journal paper is + + align:start position:0% +Gillespie and the journal paper is + + + align:start position:0% +Gillespie and the journal paper is +posted and this is just like with a + + align:start position:0% +posted and this is just like with a + + + align:start position:0% +posted and this is just like with a +Monte Carlo metropolis Monte Carlo you + + align:start position:0% +Monte Carlo metropolis Monte Carlo you + + + align:start position:0% +Monte Carlo metropolis Monte Carlo you +just did we're trying to find a way to + + align:start position:0% +just did we're trying to find a way to + + + align:start position:0% +just did we're trying to find a way to +sample from the problem the true + + align:start position:0% +sample from the problem the true + + + align:start position:0% +sample from the problem the true +probability density without ever + + align:start position:0% +probability density without ever + + + align:start position:0% +probability density without ever +computing the truth the true probability + + align:start position:0% +computing the truth the true probability + + + align:start position:0% +computing the truth the true probability +density right so in the Monte Carlo + + align:start position:0% +density right so in the Monte Carlo + + + align:start position:0% +density right so in the Monte Carlo +integration you're doing for homework + + align:start position:0% +integration you're doing for homework + + + align:start position:0% +integration you're doing for homework +you're sampling from the true Boulton + + align:start position:0% +you're sampling from the true Boulton + + + align:start position:0% +you're sampling from the true Boulton +probability density but you never + + align:start position:0% +probability density but you never + + + align:start position:0% +probability density but you never +actually split right down when that P is + + align:start position:0% +actually split right down when that P is + + + align:start position:0% +actually split right down when that P is +right and so the same we're gonna do the + + align:start position:0% +right and so the same we're gonna do the + + + align:start position:0% +right and so the same we're gonna do the +same thing here is we're gonna from the + + align:start position:0% +same thing here is we're gonna from the + + + align:start position:0% +same thing here is we're gonna from the +differential equations from this + + align:start position:0% +differential equations from this + + + align:start position:0% +differential equations from this +differential equation system here we're + + align:start position:0% +differential equation system here we're + + + align:start position:0% +differential equation system here we're +gonna try to somehow never ever solve + + align:start position:0% +gonna try to somehow never ever solve + + + align:start position:0% +gonna try to somehow never ever solve +this directly but instead just sample + + align:start position:0% +this directly but instead just sample + + + align:start position:0% +this directly but instead just sample +from the solution B which depends on + + align:start position:0% +from the solution B which depends on + + + align:start position:0% +from the solution B which depends on +time all right and the way it's done is + + align:start position:0% + + + + align:start position:0% + +it's really to try to follow individual + + align:start position:0% +it's really to try to follow individual + + + align:start position:0% +it's really to try to follow individual +trajectories of what could have happened + + align:start position:0% +trajectories of what could have happened + + + align:start position:0% +trajectories of what could have happened +okay so at any time step we have some + + align:start position:0% +okay so at any time step we have some + + + align:start position:0% +okay so at any time step we have some +number of A's B's and C's and we're + + align:start position:0% +number of A's B's and C's and we're + + + align:start position:0% +number of A's B's and C's and we're +gonna say well in the next time period + + align:start position:0% +gonna say well in the next time period + + + align:start position:0% +gonna say well in the next time period +some small time period what can happen + + align:start position:0% +some small time period what can happen + + + align:start position:0% +some small time period what can happen +and we're gonna make the time period so + + align:start position:0% +and we're gonna make the time period so + + + align:start position:0% +and we're gonna make the time period so +small they're the only thing that can + + align:start position:0% +small they're the only thing that can + + + align:start position:0% +small they're the only thing that can +happen is + + align:start position:0% +happen is + + + align:start position:0% +happen is +nothing happens and a B and C stay the + + align:start position:0% +nothing happens and a B and C stay the + + + align:start position:0% +nothing happens and a B and C stay the +same or one event happens which will + + align:start position:0% +same or one event happens which will + + + align:start position:0% +same or one event happens which will +change like the one of the numbers the + + align:start position:0% +change like the one of the numbers the + + + align:start position:0% +change like the one of the numbers the +A's B's and C's by to say one reaction + + align:start position:0% +A's B's and C's by to say one reaction + + + align:start position:0% +A's B's and C's by to say one reaction +mmm okay and then after we accomplished + + align:start position:0% +mmm okay and then after we accomplished + + + align:start position:0% +mmm okay and then after we accomplished +that now we have a new state a B and C + + align:start position:0% +that now we have a new state a B and C + + + align:start position:0% +that now we have a new state a B and C +with some new values and we'll do the + + align:start position:0% +with some new values and we'll do the + + + align:start position:0% +with some new values and we'll do the +same thing again and we just repeat that + + align:start position:0% +same thing again and we just repeat that + + + align:start position:0% +same thing again and we just repeat that +over and over so it's very brute force + + align:start position:0% +over and over so it's very brute force + + + align:start position:0% +over and over so it's very brute force +you're just doing like what a single + + align:start position:0% +you're just doing like what a single + + + align:start position:0% +you're just doing like what a single +system would do so for example for the + + align:start position:0% +system would do so for example for the + + + align:start position:0% +system would do so for example for the +uranium atom case we have one uranium + + align:start position:0% +uranium atom case we have one uranium + + + align:start position:0% +uranium atom case we have one uranium +atom in there we wait for some time + + align:start position:0% +atom in there we wait for some time + + + align:start position:0% +atom in there we wait for some time +period say 20 minutes we compute the + + align:start position:0% +period say 20 minutes we compute the + + + align:start position:0% +period say 20 minutes we compute the +probability that the Iranian would have + + align:start position:0% +probability that the Iranian would have + + + align:start position:0% +probability that the Iranian would have +decayed in the last 20 minutes it's + + align:start position:0% +decayed in the last 20 minutes it's + + + align:start position:0% +decayed in the last 20 minutes it's +pretty small and then we'll say okay now + + align:start position:0% +pretty small and then we'll say okay now + + + align:start position:0% +pretty small and then we'll say okay now +we'll draw a random number if the random + + align:start position:0% +we'll draw a random number if the random + + + align:start position:0% +we'll draw a random number if the random +number is less than that probability + + align:start position:0% +number is less than that probability + + + align:start position:0% +number is less than that probability +then we think that the uranium is still + + align:start position:0% +then we think that the uranium is still + + + align:start position:0% +then we think that the uranium is still +there and the randoms bigger than that + + align:start position:0% +there and the randoms bigger than that + + + align:start position:0% +there and the randoms bigger than that +probability then the rainy one was gone + + align:start position:0% +probability then the rainy one was gone + + + align:start position:0% +probability then the rainy one was gone +if it's still there then we'll do it + + align:start position:0% +if it's still there then we'll do it + + + align:start position:0% +if it's still there then we'll do it +again and we'll just keep doing that + + align:start position:0% +again and we'll just keep doing that + + + align:start position:0% +again and we'll just keep doing that +over and over again and we'll sample + + align:start position:0% +over and over again and we'll sample + + + align:start position:0% +over and over again and we'll sample +what could happen your any I could live + + align:start position:0% +what could happen your any I could live + + + align:start position:0% +what could happen your any I could live +for three two three eight years and 14 + + align:start position:0% +for three two three eight years and 14 + + + align:start position:0% +for three two three eight years and 14 +minutes and then disappear and that + + align:start position:0% +minutes and then disappear and that + + + align:start position:0% +minutes and then disappear and that +would be one example and then we go back + + align:start position:0% +would be one example and then we go back + + + align:start position:0% +would be one example and then we go back +and we do it again from a different + + align:start position:0% +and we do it again from a different + + + align:start position:0% +and we do it again from a different +trajectory and we do it over and over + + align:start position:0% +trajectory and we do it over and over + + + align:start position:0% +trajectory and we do it over and over +and over again and we do it over and + + align:start position:0% +and over again and we do it over and + + + align:start position:0% +and over again and we do it over and +over again those trajectories are + + align:start position:0% +over again those trajectories are + + + align:start position:0% +over again those trajectories are +sampling from what could happen with the + + align:start position:0% +sampling from what could happen with the + + + align:start position:0% +sampling from what could happen with the +right probability density this makes + + align:start position:0% +right probability density this makes + + + align:start position:0% +right probability density this makes +sense so the way Gillespie says to do it + + align:start position:0% +sense so the way Gillespie says to do it + + + align:start position:0% +sense so the way Gillespie says to do it +is figure out the the expected time + + align:start position:0% +is figure out the the expected time + + + align:start position:0% +is figure out the the expected time +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +until something will call this time tau + + align:start position:0% +until something will call this time tau + + + align:start position:0% +until something will call this time tau +okay and we'll pull actually it's not + + align:start position:0% +okay and we'll pull actually it's not + + + align:start position:0% +okay and we'll pull actually it's not +used how cuz it's hello judge I'll try + + align:start position:0% +used how cuz it's hello judge I'll try + + + align:start position:0% +used how cuz it's hello judge I'll try +Bigfoot sister with dose notation he + + align:start position:0% +Bigfoot sister with dose notation he + + + align:start position:0% +Bigfoot sister with dose notation he +calls this thing 1 over a so a is like + + align:start position:0% +calls this thing 1 over a so a is like + + + align:start position:0% +calls this thing 1 over a so a is like +the expected rate per second and + + align:start position:0% +the expected rate per second and + + + align:start position:0% +the expected rate per second and +whenever a is expected time till + + align:start position:0% +whenever a is expected time till + + + align:start position:0% +whenever a is expected time till +something would happen and then we'll + + align:start position:0% +something would happen and then we'll + + + align:start position:0% +something would happen and then we'll +draw draw a random number R because it R + + align:start position:0% +draw draw a random number R because it R + + + align:start position:0% +draw draw a random number R because it R +1 we just call the rand function it + + align:start position:0% +1 we just call the rand function it + + + align:start position:0% +1 we just call the rand function it +gives me a number between 0 and 1 and + + align:start position:0% +gives me a number between 0 and 1 and + + + align:start position:0% +gives me a number between 0 and 1 and +I'll say that my my time step delta-t + + align:start position:0% +I'll say that my my time step delta-t + + + align:start position:0% +I'll say that my my time step delta-t +which Joe calls tau is whenever a the + + align:start position:0% +which Joe calls tau is whenever a the + + + align:start position:0% +which Joe calls tau is whenever a the +logarithm of 1 over R 1 so I and I think + + align:start position:0% +logarithm of 1 over R 1 so I and I think + + + align:start position:0% +logarithm of 1 over R 1 so I and I think +there should be a negative sign no one + + align:start position:0% +there should be a negative sign no one + + + align:start position:0% +there should be a negative sign no one +of hours positive that's right alright + + align:start position:0% +of hours positive that's right alright + + + align:start position:0% +of hours positive that's right alright +so I choose a random number suppose it's + + align:start position:0% +so I choose a random number suppose it's + + + align:start position:0% +so I choose a random number suppose it's +a half then this is this fraction is 2 + + align:start position:0% +a half then this is this fraction is 2 + + + align:start position:0% +a half then this is this fraction is 2 +whatever happens to log on the 2 is to + + align:start position:0% +whatever happens to log on the 2 is to + + + align:start position:0% +whatever happens to log on the 2 is to +some number bigger than 1 and I pull + + align:start position:0% +some number bigger than 1 and I pull + + + align:start position:0% +some number bigger than 1 and I pull +that and I get some actually some that + + align:start position:0% +that and I get some actually some that + + + align:start position:0% +that and I get some actually some that +were less than 1 + + align:start position:0% +were less than 1 + + + align:start position:0% +were less than 1 +like really - anyway some positive + + align:start position:0% +like really - anyway some positive + + + align:start position:0% +like really - anyway some positive +number multiply it by the expected time + + align:start position:0% +number multiply it by the expected time + + + align:start position:0% +number multiply it by the expected time +until something happens and that's the + + align:start position:0% +until something happens and that's the + + + align:start position:0% +until something happens and that's the +time in this particular simulation when + + align:start position:0% +time in this particular simulation when + + + align:start position:0% +time in this particular simulation when +the next thing happened and then I + + align:start position:0% +the next thing happened and then I + + + align:start position:0% +the next thing happened and then I +repeat this again and again and again + + align:start position:0% +repeat this again and again and again + + + align:start position:0% +repeat this again and again and again +and I get the + + align:start position:0% +and I get the + + + align:start position:0% +and I get the +period of time intervals between when + + align:start position:0% +period of time intervals between when + + + align:start position:0% +period of time intervals between when +something happened now every time + + align:start position:0% +something happened now every time + + + align:start position:0% +something happened now every time +something happened I took a well what + + align:start position:0% +something happened I took a well what + + + align:start position:0% +something happened I took a well what +happened so if I look at my left back + + align:start position:0% +happened so if I look at my left back + + + align:start position:0% +happened so if I look at my left back +here when I had the urate uranium + + align:start position:0% +here when I had the urate uranium + + + align:start position:0% +here when I had the urate uranium +I waited along the in this particular + + align:start position:0% +I waited along the in this particular + + + align:start position:0% +I waited along the in this particular +case here's my towel call it's tell one + + align:start position:0% +case here's my towel call it's tell one + + + align:start position:0% +case here's my towel call it's tell one +time that it took for the first thing to + + align:start position:0% +time that it took for the first thing to + + + align:start position:0% +time that it took for the first thing to +happen and then well what could happen + + align:start position:0% +happen and then well what could happen + + + align:start position:0% +happen and then well what could happen +the only thing that can happen my single + + align:start position:0% +the only thing that can happen my single + + + align:start position:0% +the only thing that can happen my single +uranium I you ready + + align:start position:0% +uranium I you ready + + + align:start position:0% +uranium I you ready +uranium atom case is it decayed so it + + align:start position:0% +uranium atom case is it decayed so it + + + align:start position:0% +uranium atom case is it decayed so it +went away all right and then I do the + + align:start position:0% +went away all right and then I do the + + + align:start position:0% +went away all right and then I do the +random number thing again and I draw on + + align:start position:0% +random number thing again and I draw on + + + align:start position:0% +random number thing again and I draw on +I get a different number this time how + + align:start position:0% +I get a different number this time how + + + align:start position:0% +I get a different number this time how +long it is still something yeah + + align:start position:0% + + + + align:start position:0% + +now notice maybe it's not too obvious + + align:start position:0% +now notice maybe it's not too obvious + + + align:start position:0% +now notice maybe it's not too obvious +that the time until something happens + + align:start position:0% +that the time until something happens + + + align:start position:0% +that the time until something happens +changes as you run so for example if I + + align:start position:0% +changes as you run so for example if I + + + align:start position:0% +changes as you run so for example if I +start out with 100 uranium atoms in a + + align:start position:0% +start out with 100 uranium atoms in a + + + align:start position:0% +start out with 100 uranium atoms in a +hundred little boxes and I'm watching + + align:start position:0% +hundred little boxes and I'm watching + + + align:start position:0% +hundred little boxes and I'm watching +them after I've run this for a long time + + align:start position:0% +them after I've run this for a long time + + + align:start position:0% +them after I've run this for a long time +I only have 50 uranium atoms left and + + align:start position:0% +I only have 50 uranium atoms left and + + + align:start position:0% +I only have 50 uranium atoms left and +that means that the average time period + + align:start position:0% +that means that the average time period + + + align:start position:0% +that means that the average time period +until something happens will be slower + + align:start position:0% +until something happens will be slower + + + align:start position:0% +until something happens will be slower +because I don't have as many the more I + + align:start position:0% +because I don't have as many the more I + + + align:start position:0% +because I don't have as many the more I +have the more rapidly something will + + align:start position:0% +have the more rapidly something will + + + align:start position:0% +have the more rapidly something will +happen so it makes sense so I have to + + align:start position:0% +happen so it makes sense so I have to + + + align:start position:0% +happen so it makes sense so I have to +compute this a thing at each iteration + + align:start position:0% +compute this a thing at each iteration + + + align:start position:0% +compute this a thing at each iteration +so I compute the time until something + + align:start position:0% +so I compute the time until something + + + align:start position:0% +so I compute the time until something +happens then I'm going to compute what + + align:start position:0% +happens then I'm going to compute what + + + align:start position:0% +happens then I'm going to compute what +happened I'll tell you about that in a + + align:start position:0% +happened I'll tell you about that in a + + + align:start position:0% +happened I'll tell you about that in a +second in the uranium case the only + + align:start position:0% +second in the uranium case the only + + + align:start position:0% +second in the uranium case the only +thing that can happen is the uranium one + + align:start position:0% +thing that can happen is the uranium one + + + align:start position:0% +thing that can happen is the uranium one +uranium is decayed so I took that away + + align:start position:0% +uranium is decayed so I took that away + + + align:start position:0% +uranium is decayed so I took that away +now I have to compute a again so a is + + align:start position:0% +now I have to compute a again so a is + + + align:start position:0% +now I have to compute a again so a is +the sum of all the things that can + + align:start position:0% +the sum of all the things that can + + + align:start position:0% +the sum of all the things that can +happen so in my case where I have a + + align:start position:0% +happen so in my case where I have a + + + align:start position:0% +happen so in my case where I have a +hundred rate uranium atoms I have 100 + + align:start position:0% +hundred rate uranium atoms I have 100 + + + align:start position:0% +hundred rate uranium atoms I have 100 +different boxes in each one of them + + align:start position:0% +different boxes in each one of them + + + align:start position:0% +different boxes in each one of them +there's a rate at which the uranium is + + align:start position:0% +there's a rate at which the uranium is + + + align:start position:0% +there's a rate at which the uranium is +probability is decay it's like 1 over + + align:start position:0% +probability is decay it's like 1 over + + + align:start position:0% +probability is decay it's like 1 over +the normal half-life uranium something + + align:start position:0% +the normal half-life uranium something + + + align:start position:0% +the normal half-life uranium something +like that and I add them up so a is the + + align:start position:0% +like that and I add them up so a is the + + + align:start position:0% +like that and I add them up so a is the +sum of the race + + align:start position:0% + + + + align:start position:0% + +of everything that can happen so I just + + align:start position:0% +of everything that can happen so I just + + + align:start position:0% +of everything that can happen so I just +list out all the different things that + + align:start position:0% +list out all the different things that + + + align:start position:0% +list out all the different things that +can happen so in the case is supposed to + + align:start position:0% +can happen so in the case is supposed to + + + align:start position:0% +can happen so in the case is supposed to +have two eight two boxes to uranium + + align:start position:0% +have two eight two boxes to uranium + + + align:start position:0% +have two eight two boxes to uranium +atoms I can have decay of Rio grab + + align:start position:0% +atoms I can have decay of Rio grab + + + align:start position:0% +atoms I can have decay of Rio grab +number one or uranium atom number two so + + align:start position:0% +number one or uranium atom number two so + + + align:start position:0% +number one or uranium atom number two so +I have this this thing would be equal to + + align:start position:0% +I have this this thing would be equal to + + + align:start position:0% +I have this this thing would be equal to +two uranium times a it's equal to 1 over + + align:start position:0% +two uranium times a it's equal to 1 over + + + align:start position:0% +two uranium times a it's equal to 1 over +tau normal for a uranium atom I'll swing + + align:start position:0% +tau normal for a uranium atom I'll swing + + + align:start position:0% +tau normal for a uranium atom I'll swing +over town normal cuz they're both normal + + align:start position:0% +over town normal cuz they're both normal + + + align:start position:0% +over town normal cuz they're both normal +really matters this is equal to two over + + align:start position:0% +really matters this is equal to two over + + + align:start position:0% +really matters this is equal to two over +tau and so whatever a is half of the + + align:start position:0% +tau and so whatever a is half of the + + + align:start position:0% +tau and so whatever a is half of the +half of the normal lifetime and that's + + align:start position:0% +half of the normal lifetime and that's + + + align:start position:0% +half of the normal lifetime and that's +when I would expect that something would + + align:start position:0% +when I would expect that something would + + + align:start position:0% +when I would expect that something would +happen by then okay one of them would + + align:start position:0% +happen by then okay one of them would + + + align:start position:0% +happen by then okay one of them would +one would probably decay so that would + + align:start position:0% +one would probably decay so that would + + + align:start position:0% +one would probably decay so that would +be the a value I would use here draw my + + align:start position:0% +be the a value I would use here draw my + + + align:start position:0% +be the a value I would use here draw my +random number get my towel until + + align:start position:0% +random number get my towel until + + + align:start position:0% +random number get my towel until +something probably happened then figure + + align:start position:0% +something probably happened then figure + + + align:start position:0% +something probably happened then figure +out what happens now in the kinetics + + align:start position:0% +out what happens now in the kinetics + + + align:start position:0% +out what happens now in the kinetics +case several different things can happen + + align:start position:0% +case several different things can happen + + + align:start position:0% +case several different things can happen +right I wrote down if I'm in state n a n + + align:start position:0% +right I wrote down if I'm in state n a n + + + align:start position:0% +right I wrote down if I'm in state n a n +a and B and C I the the state can change + + align:start position:0% +a and B and C I the the state can change + + + align:start position:0% +a and B and C I the the state can change +by two different ways I can I can move + + align:start position:0% +by two different ways I can I can move + + + align:start position:0% +by two different ways I can I can move +out of that state this way or this way + + align:start position:0% +out of that state this way or this way + + + align:start position:0% +out of that state this way or this way +right Toofer reactions happen for a + + align:start position:0% +right Toofer reactions happen for a + + + align:start position:0% +right Toofer reactions happen for a +reverse reaction and they will go to + + align:start position:0% +reverse reaction and they will go to + + + align:start position:0% +reverse reaction and they will go to +take me out of the state so those are + + align:start position:0% +take me out of the state so those are + + + align:start position:0% +take me out of the state so those are +two different things they happen and so + + align:start position:0% +two different things they happen and so + + + align:start position:0% +two different things they happen and so +I have to add the product those rates so + + align:start position:0% +I have to add the product those rates so + + + align:start position:0% +I have to add the product those rates so +I would add this number and this number + + align:start position:0% +I would add this number and this number + + + align:start position:0% +I would add this number and this number +and they would be the two things that + + align:start position:0% +and they would be the two things that + + + align:start position:0% +and they would be the two things that +could happen that would give me that a + + align:start position:0% +could happen that would give me that a + + + align:start position:0% +could happen that would give me that a +die + + align:start position:0% +die + + + align:start position:0% +die +now I I figured out something happened + + align:start position:0% +now I I figured out something happened + + + align:start position:0% +now I I figured out something happened +but now I'm not doing uranium now I'm + + align:start position:0% +but now I'm not doing uranium now I'm + + + align:start position:0% +but now I'm not doing uranium now I'm +doing a number of A's and I figure + + align:start position:0% +doing a number of A's and I figure + + + align:start position:0% +doing a number of A's and I figure +something it happened + + align:start position:0% +something it happened + + + align:start position:0% +something it happened +- what happened and the number of A's + + align:start position:0% +- what happened and the number of A's + + + align:start position:0% +- what happened and the number of A's +could have gone up or gone down because + + align:start position:0% +could have gone up or gone down because + + + align:start position:0% +could have gone up or gone down because +it was a forward reaction number of ADEs + + align:start position:0% +it was a forward reaction number of ADEs + + + align:start position:0% +it was a forward reaction number of ADEs +went down if it was a reverse reaction + + align:start position:0% +went down if it was a reverse reaction + + + align:start position:0% +went down if it was a reverse reaction +number days went up so I had to decide + + align:start position:0% +number days went up so I had to decide + + + align:start position:0% +number days went up so I had to decide +which way is gonna happen so I could + + align:start position:0% +which way is gonna happen so I could + + + align:start position:0% +which way is gonna happen so I could +have either the number of A's went down + + align:start position:0% +have either the number of A's went down + + + align:start position:0% +have either the number of A's went down +or their race went up there's are two + + align:start position:0% +or their race went up there's are two + + + align:start position:0% +or their race went up there's are two +possibilities I had to figure which one + + align:start position:0% +possibilities I had to figure which one + + + align:start position:0% +possibilities I had to figure which one +happened I have to figure it draw + + align:start position:0% +happened I have to figure it draw + + + align:start position:0% +happened I have to figure it draw +another random number to figure out + + align:start position:0% +another random number to figure out + + + align:start position:0% +another random number to figure out +which one probably happened so I'll list + + align:start position:0% +which one probably happened so I'll list + + + align:start position:0% +which one probably happened so I'll list +out the list of all the things that can + + align:start position:0% +out the list of all the things that can + + + align:start position:0% +out the list of all the things that can +happen with their rates and one of them + + align:start position:0% +happen with their rates and one of them + + + align:start position:0% +happen with their rates and one of them +say is twice as big as the other so that + + align:start position:0% +say is twice as big as the other so that + + + align:start position:0% +say is twice as big as the other so that +it'll be twice as likely to happen so I + + align:start position:0% +it'll be twice as likely to happen so I + + + align:start position:0% +it'll be twice as likely to happen so I +have to choose a round number and use + + align:start position:0% +have to choose a round number and use + + + align:start position:0% +have to choose a round number and use +that to choose the next one so so first + + align:start position:0% +that to choose the next one so so first + + + align:start position:0% +that to choose the next one so so first +I figured it out this is actually did + + align:start position:0% +I figured it out this is actually did + + + align:start position:0% +I figured it out this is actually did +first I figured out what my rates are + + align:start position:0% +first I figured out what my rates are + + + align:start position:0% +first I figured out what my rates are +second thing is I figure out the time + + align:start position:0% +second thing is I figure out the time + + + align:start position:0% +second thing is I figure out the time +until something happened third thing is + + align:start position:0% +until something happened third thing is + + + align:start position:0% +until something happened third thing is +I'm going to figure out what happened + + align:start position:0% + + + + align:start position:0% + +and what I do is I say I draw a random + + align:start position:0% +and what I do is I say I draw a random + + + align:start position:0% +and what I do is I say I draw a random +number call r2 and if there's only two + + align:start position:0% +number call r2 and if there's only two + + + align:start position:0% +number call r2 and if there's only two +possibilities like in this case then I + + align:start position:0% +possibilities like in this case then I + + + align:start position:0% +possibilities like in this case then I +can say if r2 is less than the re + + align:start position:0% +can say if r2 is less than the re + + + align:start position:0% +can say if r2 is less than the re +process 1 divided by the sum of the + + align:start position:0% +process 1 divided by the sum of the + + + align:start position:0% +process 1 divided by the sum of the +rates which is the same as that a right + + align:start position:0% +rates which is the same as that a right + + + align:start position:0% +rates which is the same as that a right +this is hey this is true then process 1 + + align:start position:0% +this is hey this is true then process 1 + + + align:start position:0% +this is hey this is true then process 1 +happened on the other hand if the rate + + align:start position:0% +happened on the other hand if the rate + + + align:start position:0% +happened on the other hand if the rate +of the remember I chose is larger than + + align:start position:0% +of the remember I chose is larger than + + + align:start position:0% +of the remember I chose is larger than +this ratio then I'll say process two + + align:start position:0% +this ratio then I'll say process two + + + align:start position:0% +this ratio then I'll say process two +happened and that's how I decide whether + + align:start position:0% +happened and that's how I decide whether + + + align:start position:0% +happened and that's how I decide whether +the number of A's went up and went down + + align:start position:0% +the number of A's went up and went down + + + align:start position:0% +the number of A's went up and went down +and then it would recompute the a + + align:start position:0% +and then it would recompute the a + + + align:start position:0% +and then it would recompute the a +depending on what happens suppose I I do + + align:start position:0% +depending on what happens suppose I I do + + + align:start position:0% +depending on what happens suppose I I do +this and I found out that the number of + + align:start position:0% +this and I found out that the number of + + + align:start position:0% +this and I found out that the number of +A's went up is my crude my drawing the + + align:start position:0% +A's went up is my crude my drawing the + + + align:start position:0% +A's went up is my crude my drawing the +random number that I'll go and I'll + + align:start position:0% +random number that I'll go and I'll + + + align:start position:0% +random number that I'll go and I'll +recompute da now the rates all be + + align:start position:0% +recompute da now the rates all be + + + align:start position:0% +recompute da now the rates all be +different because + + align:start position:0% +different because + + + align:start position:0% +different because +n/a is bigger so the rate of DNA + + align:start position:0% +n/a is bigger so the rate of DNA + + + align:start position:0% +n/a is bigger so the rate of DNA +reaction is faster so I recompute it I + + align:start position:0% +reaction is faster so I recompute it I + + + align:start position:0% +reaction is faster so I recompute it I +redraw a number here I get some + + align:start position:0% +redraw a number here I get some + + + align:start position:0% +redraw a number here I get some +different time tattoo it's not the same + + align:start position:0% +different time tattoo it's not the same + + + align:start position:0% +different time tattoo it's not the same +as tell one and then something happened + + align:start position:0% +as tell one and then something happened + + + align:start position:0% +as tell one and then something happened +here I do the same process here to + + align:start position:0% +here I do the same process here to + + + align:start position:0% +here I do the same process here to +figure out what happened maybe this time + + align:start position:0% +figure out what happened maybe this time + + + align:start position:0% +figure out what happened maybe this time +they reacted away and then went Benton + + align:start position:0% +they reacted away and then went Benton + + + align:start position:0% +they reacted away and then went Benton +alright and then I do it again and this + + align:start position:0% +alright and then I do it again and this + + + align:start position:0% +alright and then I do it again and this +time I draw a longer time tau 3 and I do + + align:start position:0% +time I draw a longer time tau 3 and I do + + + align:start position:0% +time I draw a longer time tau 3 and I do +what happened that made this time again + + align:start position:0% +what happened that made this time again + + + align:start position:0% +what happened that made this time again +something reacted away in it with them + + align:start position:0% +something reacted away in it with them + + + align:start position:0% +something reacted away in it with them +and I don't know and after my computer + + align:start position:0% +and I don't know and after my computer + + + align:start position:0% +and I don't know and after my computer +is done doing that for a while I got so + + align:start position:0% +is done doing that for a while I got so + + + align:start position:0% +is done doing that for a while I got so +long enough time I say okay I'm done oh + + align:start position:0% +long enough time I say okay I'm done oh + + + align:start position:0% +long enough time I say okay I'm done oh +I don't really don't have to go back and + + align:start position:0% +I don't really don't have to go back and + + + align:start position:0% +I don't really don't have to go back and +start again and run another simulation + + align:start position:0% +start again and run another simulation + + + align:start position:0% +start again and run another simulation +to run through all the possibilities and + + align:start position:0% +to run through all the possibilities and + + + align:start position:0% +to run through all the possibilities and +what I save all these results of all + + align:start position:0% +what I save all these results of all + + + align:start position:0% +what I save all these results of all +these simulations because these guys are + + align:start position:0% +these simulations because these guys are + + + align:start position:0% +these simulations because these guys are +samples from the probability + + align:start position:0% +samples from the probability + + + align:start position:0% +samples from the probability +distribution and if I build histograms + + align:start position:0% +distribution and if I build histograms + + + align:start position:0% +distribution and if I build histograms +and stuff from those guys I can figure + + align:start position:0% +and stuff from those guys I can figure + + + align:start position:0% +and stuff from those guys I can figure +out what really is gonna have them all + + align:start position:0% +out what really is gonna have them all + + + align:start position:0% +out what really is gonna have them all +right so it's a way to represent the P + + align:start position:0% +right so it's a way to represent the P + + + align:start position:0% +right so it's a way to represent the P +questions alright hope you'll clear all + + align:start position:0% +questions alright hope you'll clear all + + + align:start position:0% +questions alright hope you'll clear all +right so it's nice about this is + + align:start position:0% +right so it's nice about this is + + + align:start position:0% +right so it's nice about this is +actually it's not that hard once you do + + align:start position:0% +actually it's not that hard once you do + + + align:start position:0% +actually it's not that hard once you do +this once it's not hard to do it and you + + align:start position:0% +this once it's not hard to do it and you + + + align:start position:0% +this once it's not hard to do it and you +do for any problem at all + + align:start position:0% +do for any problem at all + + + align:start position:0% +do for any problem at all +and so it's like often cases people do + + align:start position:0% +and so it's like often cases people do + + + align:start position:0% +and so it's like often cases people do +this even for cases where you actually + + align:start position:0% +this even for cases where you actually + + + align:start position:0% +this even for cases where you actually +could solve you might be able to solve + + align:start position:0% +could solve you might be able to solve + + + align:start position:0% +could solve you might be able to solve +this equation + + align:start position:0% +this equation + + + align:start position:0% +this equation +a lot times when people won't do it + + align:start position:0% +a lot times when people won't do it + + + align:start position:0% +a lot times when people won't do it +don't do this instead just cuz it's so + + align:start position:0% +don't do this instead just cuz it's so + + + align:start position:0% +don't do this instead just cuz it's so +easy so although May it looks hard to + + align:start position:0% +easy so although May it looks hard to + + + align:start position:0% +easy so although May it looks hard to +you right now it's only a three step + + align:start position:0% +you right now it's only a three step + + + align:start position:0% +you right now it's only a three step +thing you just do it over and over again + + align:start position:0% +thing you just do it over and over again + + + align:start position:0% +thing you just do it over and over again +you're not doing it the computers doing + + align:start position:0% +you're not doing it the computers doing + + + align:start position:0% +you're not doing it the computers doing +it no big deal + + align:start position:0% +it no big deal + + + align:start position:0% +it no big deal +and so this one you have to like look at + + align:start position:0% +and so this one you have to like look at + + + align:start position:0% +and so this one you have to like look at +the sparsity pattern of your m there's a + + align:start position:0% +the sparsity pattern of your m there's a + + + align:start position:0% +the sparsity pattern of your m there's a +complicated stuff so this is actually + + align:start position:0% +complicated stuff so this is actually + + + align:start position:0% +complicated stuff so this is actually +done extremely a commonly alright see + + align:start position:0% +done extremely a commonly alright see + + + align:start position:0% +done extremely a commonly alright see +you on Friday \ No newline at end of file diff --git a/uS-w4yl35vc.txt b/uS-w4yl35vc.txt new file mode 100644 index 0000000000000000000000000000000000000000..616755c32adc27f801c941014a39e7cd676f6ffd --- /dev/null +++ b/uS-w4yl35vc.txt @@ -0,0 +1,13659 @@ +align:start position:0% + +so today in case you were thinking that + + align:start position:0% +so today in case you were thinking that + + + align:start position:0% +so today in case you were thinking that +there wasn't enough theorems on Tuesday + + align:start position:0% +there wasn't enough theorems on Tuesday + + + align:start position:0% +there wasn't enough theorems on Tuesday +we're going to approve a lot of them + + align:start position:0% +we're going to approve a lot of them + + + align:start position:0% +we're going to approve a lot of them +today on the general metric space Theory + + align:start position:0% +today on the general metric space Theory + + + align:start position:0% +today on the general metric space Theory +I I like this notion of a theory of the + + align:start position:0% +I I like this notion of a theory of the + + + align:start position:0% +I I like this notion of a theory of the +spaces this is a notation that um Dr + + align:start position:0% +spaces this is a notation that um Dr + + + align:start position:0% +spaces this is a notation that um Dr +Casey Rodriguez taught me Loosely + + align:start position:0% +Casey Rodriguez taught me Loosely + + + align:start position:0% +Casey Rodriguez taught me Loosely +speaking where you know you're just + + align:start position:0% +speaking where you know you're just + + + align:start position:0% +speaking where you know you're just +trying to encapsulate what are all the + + align:start position:0% +trying to encapsulate what are all the + + + align:start position:0% +trying to encapsulate what are all the +things we can say about the most + + align:start position:0% +things we can say about the most + + + align:start position:0% +things we can say about the most +fundamental objects in the space that + + align:start position:0% +fundamental objects in the space that + + + align:start position:0% +fundamental objects in the space that +you're considering and a number of them + + align:start position:0% +you're considering and a number of them + + + align:start position:0% +you're considering and a number of them +will essentially a number of the + + align:start position:0% +will essentially a number of the + + + align:start position:0% +will essentially a number of the +theorems that will prove are essentially + + align:start position:0% +theorems that will prove are essentially + + + align:start position:0% +theorems that will prove are essentially +the same as what we would picture in + + align:start position:0% +the same as what we would picture in + + + align:start position:0% +the same as what we would picture in +ukian space but we have to be slightly + + align:start position:0% +ukian space but we have to be slightly + + + align:start position:0% +ukian space but we have to be slightly +more careful sometimes and all of this + + align:start position:0% +more careful sometimes and all of this + + + align:start position:0% +more careful sometimes and all of this +theory is going to be building up to + + align:start position:0% +theory is going to be building up to + + + align:start position:0% +theory is going to be building up to +understanding something that you + + align:start position:0% +understanding something that you + + + align:start position:0% +understanding something that you +probably haven't seen before if you + + align:start position:0% +probably haven't seen before if you + + + align:start position:0% +probably haven't seen before if you +haven't done 100b known as compact sets + + align:start position:0% +haven't done 100b known as compact sets + + + align:start position:0% +haven't done 100b known as compact sets +so we're going to be building up to + + align:start position:0% +so we're going to be building up to + + + align:start position:0% +so we're going to be building up to +talking about compact sets but first we + + align:start position:0% +talking about compact sets but first we + + + align:start position:0% +talking about compact sets but first we +have to understand what are the + + align:start position:0% +have to understand what are the + + + align:start position:0% +have to understand what are the +fundamental Tools in our tool belt with + + align:start position:0% +fundamental Tools in our tool belt with + + + align:start position:0% +fundamental Tools in our tool belt with +metrics based Theory and I do want to + + align:start position:0% +metrics based Theory and I do want to + + + align:start position:0% +metrics based Theory and I do want to +Note One Thing even though last time I + + align:start position:0% +Note One Thing even though last time I + + + align:start position:0% +Note One Thing even though last time I +said we can put a metric on every set + + align:start position:0% +said we can put a metric on every set + + + align:start position:0% +said we can put a metric on every set +which is true not every set has a nice + + align:start position:0% +which is true not every set has a nice + + + align:start position:0% +which is true not every set has a nice +metric on it uh in case have any of + + align:start position:0% +metric on it uh in case have any of + + + align:start position:0% +metric on it uh in case have any of +youall Taken topology before no worries + + align:start position:0% +youall Taken topology before no worries + + + align:start position:0% +youall Taken topology before no worries +if not it's a class that usually comes + + align:start position:0% +if not it's a class that usually comes + + + align:start position:0% +if not it's a class that usually comes +after real analysis but in topology talk + + align:start position:0% +after real analysis but in topology talk + + + align:start position:0% +after real analysis but in topology talk +not every topological space is + + align:start position:0% +not every topological space is + + + align:start position:0% +not every topological space is +metrizable I.E there's not necessarily a + + align:start position:0% +metrizable I.E there's not necessarily a + + + align:start position:0% +metrizable I.E there's not necessarily a +metric on it that will make the topology + + align:start position:0% +metric on it that will make the topology + + + align:start position:0% +metric on it that will make the topology +nice and we'll talk about what topology + + align:start position:0% +nice and we'll talk about what topology + + + align:start position:0% +nice and we'll talk about what topology +is a little bit today so in case you're + + align:start position:0% +is a little bit today so in case you're + + + align:start position:0% +is a little bit today so in case you're +interested in what that statement is + + align:start position:0% +interested in what that statement is + + + align:start position:0% +interested in what that statement is +we'll come to it but the basic idea is + + align:start position:0% +we'll come to it but the basic idea is + + + align:start position:0% +we'll come to it but the basic idea is +even though we can put a metric on every + + align:start position:0% +even though we can put a metric on every + + + align:start position:0% +even though we can put a metric on every +set it's sometimes the trivial one is + + align:start position:0% +set it's sometimes the trivial one is + + + align:start position:0% +set it's sometimes the trivial one is +not that interesting + + align:start position:0% +not that interesting + + + align:start position:0% +not that interesting +so all right let's go ahead and jump + + align:start position:0% +so all right let's go ahead and jump + + + align:start position:0% +so all right let's go ahead and jump +into the metric Bas theory for + + align:start position:0% +into the metric Bas theory for + + + align:start position:0% +into the metric Bas theory for +today so first off we're going to be + + align:start position:0% +today so first off we're going to be + + + align:start position:0% +today so first off we're going to be +talking about convergent sequences just + + align:start position:0% +talking about convergent sequences just + + + align:start position:0% +talking about convergent sequences just +like we did in RN so throughout + + align:start position:0% +like we did in RN so throughout + + + align:start position:0% +like we did in RN so throughout +this let + + align:start position:0% +this let + + + align:start position:0% +this let +xn and YN + + align:start position:0% +xn and YN + + + align:start position:0% +xn and YN +be the sequences we're + + align:start position:0% + + + + align:start position:0% + +considering and the first + + align:start position:0% +considering and the first + + + align:start position:0% +considering and the first +statement + + align:start position:0% +statement + + + align:start position:0% +statement +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +suppose + + align:start position:0% +suppose + + + align:start position:0% +suppose +xn converges to x what should we expect + + align:start position:0% +xn converges to x what should we expect + + + align:start position:0% +xn converges to x what should we expect +about the point that it converges to + + align:start position:0% +about the point that it converges to + + + align:start position:0% +about the point that it converges to +well in ukian space we knew that this + + align:start position:0% +well in ukian space we knew that this + + + align:start position:0% +well in ukian space we knew that this +limit point had to be unique and in fact + + align:start position:0% +limit point had to be unique and in fact + + + align:start position:0% +limit point had to be unique and in fact +we can prove that this must be the + + align:start position:0% +we can prove that this must be the + + + align:start position:0% +we can prove that this must be the +case uh so + + align:start position:0% +case uh so + + + align:start position:0% +case uh so +then X is + + align:start position:0% + + + + align:start position:0% + +unique to prove a statement like this we + + align:start position:0% +unique to prove a statement like this we + + + align:start position:0% +unique to prove a statement like this we +choose a different point Y in our set to + + align:start position:0% +choose a different point Y in our set to + + + align:start position:0% +choose a different point Y in our set to +consider so what we're going to show now + + align:start position:0% +consider so what we're going to show now + + + align:start position:0% +consider so what we're going to show now +is that convergent sequences have unique + + align:start position:0% +is that convergent sequences have unique + + + align:start position:0% +is that convergent sequences have unique +limit points so + + align:start position:0% +limit points so + + + align:start position:0% +limit points so +prove + + align:start position:0% + + + + align:start position:0% + +Suppose there exists a y in your metric + + align:start position:0% +Suppose there exists a y in your metric + + + align:start position:0% +Suppose there exists a y in your metric +base X oh I should say sequences in your + + align:start position:0% +base X oh I should say sequences in your + + + align:start position:0% +base X oh I should say sequences in your +metric base + + align:start position:0% +metric base + + + align:start position:0% +metric base +XD so metric Bas x with metric D and + + align:start position:0% +XD so metric Bas x with metric D and + + + align:start position:0% +XD so metric Bas x with metric D and +suppose that there exists a y and x such + + align:start position:0% + + + + align:start position:0% + +that X then converges to Y our end goal + + align:start position:0% +that X then converges to Y our end goal + + + align:start position:0% +that X then converges to Y our end goal +is to show then that X must be equal to + + align:start position:0% +is to show then that X must be equal to + + + align:start position:0% +is to show then that X must be equal to +Y in fact now to do this what do we know + + align:start position:0% +Y in fact now to do this what do we know + + + align:start position:0% +Y in fact now to do this what do we know +about equality for points well by the + + align:start position:0% +about equality for points well by the + + + align:start position:0% +about equality for points well by the +axioms of what we're defining a metric + + align:start position:0% +axioms of what we're defining a metric + + + align:start position:0% +axioms of what we're defining a metric +space to be two points are going to be + + align:start position:0% +space to be two points are going to be + + + align:start position:0% +space to be two points are going to be +the same if the distance is precisely + + align:start position:0% +the same if the distance is precisely + + + align:start position:0% +the same if the distance is precisely +zero it's an if and only a statement so + + align:start position:0% +zero it's an if and only a statement so + + + align:start position:0% +zero it's an if and only a statement so +that's what we want to prove we want to + + align:start position:0% +that's what we want to prove we want to + + + align:start position:0% +that's what we want to prove we want to +prove that the distance between X and Y + + align:start position:0% +prove that the distance between X and Y + + + align:start position:0% +prove that the distance between X and Y +is zero so how can we do that well + + align:start position:0% +is zero so how can we do that well + + + align:start position:0% +is zero so how can we do that well +firstly let's write down what the + + align:start position:0% +firstly let's write down what the + + + align:start position:0% +firstly let's write down what the +definitions of them converging to X and + + align:start position:0% +definitions of them converging to X and + + + align:start position:0% +definitions of them converging to X and +Y is respectively so xn converges to X + + align:start position:0% +Y is respectively so xn converges to X + + + align:start position:0% +Y is respectively so xn converges to X +means that for all Epsilon bigger than + + align:start position:0% +means that for all Epsilon bigger than + + + align:start position:0% +means that for all Epsilon bigger than +zero there exists an n in the natural + + align:start position:0% +zero there exists an n in the natural + + + align:start position:0% +zero there exists an n in the natural +numbers such that for all n bigger than + + align:start position:0% +numbers such that for all n bigger than + + + align:start position:0% +numbers such that for all n bigger than +or equal to n and I'll this + + align:start position:0% +or equal to n and I'll this + + + align:start position:0% +or equal to n and I'll this +N1 we have that the distance from xn to + + align:start position:0% +N1 we have that the distance from xn to + + + align:start position:0% +N1 we have that the distance from xn to +X is less than Epsilon this is the + + align:start position:0% +X is less than Epsilon this is the + + + align:start position:0% +X is less than Epsilon this is the +definition of convergent sequence that + + align:start position:0% +definition of convergent sequence that + + + align:start position:0% +definition of convergent sequence that +we're dealing + + align:start position:0% +we're dealing + + + align:start position:0% +we're dealing +with and similarly xn converges to Y if + + align:start position:0% +with and similarly xn converges to Y if + + + align:start position:0% +with and similarly xn converges to Y if +there exists an N2 in the natural + + align:start position:0% +there exists an N2 in the natural + + + align:start position:0% +there exists an N2 in the natural +numbers for this Epsilon such that for + + align:start position:0% +numbers for this Epsilon such that for + + + align:start position:0% +numbers for this Epsilon such that for +such that for all n bigger than or equal + + align:start position:0% +such that for all n bigger than or equal + + + align:start position:0% +such that for all n bigger than or equal +to + + align:start position:0% +to + + + align:start position:0% +to +N2 the distance from xn to + + align:start position:0% +N2 the distance from xn to + + + align:start position:0% +N2 the distance from xn to +Y is is less than + + align:start position:0% +Y is is less than + + + align:start position:0% +Y is is less than +Epsilon so now what do we want to do we + + align:start position:0% +Epsilon so now what do we want to do we + + + align:start position:0% +Epsilon so now what do we want to do we +want to use this to show that the + + align:start position:0% +want to use this to show that the + + + align:start position:0% +want to use this to show that the +distance between X and Y is small and to + + align:start position:0% +distance between X and Y is small and to + + + align:start position:0% +distance between X and Y is small and to +do this we'll apply the triangle + + align:start position:0% +do this we'll apply the triangle + + + align:start position:0% +do this we'll apply the triangle +inequality to understand the distance + + align:start position:0% +inequality to understand the distance + + + align:start position:0% +inequality to understand the distance +from X to + + align:start position:0% +from X to + + + align:start position:0% +from X to +Y so by the triangle inequality this is + + align:start position:0% +Y so by the triangle inequality this is + + + align:start position:0% +Y so by the triangle inequality this is +less than or equal to the distance from + + align:start position:0% +less than or equal to the distance from + + + align:start position:0% +less than or equal to the distance from +xn to X plus the distance from + + align:start position:0% +xn to X plus the distance from + + + align:start position:0% +xn to X plus the distance from +xn to Y where here I'm applying symmetry + + align:start position:0% +xn to Y where here I'm applying symmetry + + + align:start position:0% +xn to Y where here I'm applying symmetry +so that I can move the terms around + + align:start position:0% +so that I can move the terms around + + + align:start position:0% +so that I can move the terms around +right and this we know that for all + + align:start position:0% +right and this we know that for all + + + align:start position:0% +right and this we know that for all +Epsilon bigger than + + align:start position:0% +Epsilon bigger than + + + align:start position:0% +Epsilon bigger than +zero there exists an N let's say this is + + align:start position:0% +zero there exists an N let's say this is + + + align:start position:0% +zero there exists an N let's say this is +equal to the + + align:start position:0% +equal to the + + + align:start position:0% +equal to the +maximum of N1 and + + align:start position:0% +maximum of N1 and + + + align:start position:0% +maximum of N1 and +N2 in the natural + + align:start position:0% +N2 in the natural + + + align:start position:0% +N2 in the natural +numbers such that both of these terms + + align:start position:0% +numbers such that both of these terms + + + align:start position:0% +numbers such that both of these terms +are now less than Epsilon in fact you + + align:start position:0% +are now less than Epsilon in fact you + + + align:start position:0% +are now less than Epsilon in fact you +know what to make it nicer I'll make + + align:start position:0% +know what to make it nicer I'll make + + + align:start position:0% +know what to make it nicer I'll make +this Epsilon over two both + + align:start position:0% +this Epsilon over two both + + + align:start position:0% +this Epsilon over two both +spots so then this is less than Epsilon + + align:start position:0% +spots so then this is less than Epsilon + + + align:start position:0% +spots so then this is less than Epsilon +/ 2 plus Epsilon / 2 which is equal to + + align:start position:0% +/ 2 plus Epsilon / 2 which is equal to + + + align:start position:0% +/ 2 plus Epsilon / 2 which is equal to +Epsilon now does this imp immediately + + align:start position:0% +Epsilon now does this imp immediately + + + align:start position:0% +Epsilon now does this imp immediately +that the uh that the distance between + + align:start position:0% +that the uh that the distance between + + + align:start position:0% +that the uh that the distance between +them is zero essentially we have to note + + align:start position:0% +them is zero essentially we have to note + + + align:start position:0% +them is zero essentially we have to note +one more thing which is that distances + + align:start position:0% +one more thing which is that distances + + + align:start position:0% +one more thing which is that distances +are positive definite so this is going + + align:start position:0% +are positive definite so this is going + + + align:start position:0% +are positive definite so this is going +to be bigger than or equal to zero so + + align:start position:0% +to be bigger than or equal to zero so + + + align:start position:0% +to be bigger than or equal to zero so +what this tells you is that because + + align:start position:0% +what this tells you is that because + + + align:start position:0% +what this tells you is that because +these the distance between X and Y gets + + align:start position:0% +these the distance between X and Y gets + + + align:start position:0% +these the distance between X and Y gets +arbitrarily + + align:start position:0% +arbitrarily + + + align:start position:0% +arbitrarily +small and arbitrarily small and close to + + align:start position:0% +small and arbitrarily small and close to + + + align:start position:0% +small and arbitrarily small and close to +zero it has to be zero this is from the + + align:start position:0% +zero it has to be zero this is from the + + + align:start position:0% +zero it has to be zero this is from the +real number theory that we've already + + align:start position:0% +real number theory that we've already + + + align:start position:0% +real number theory that we've already +know so this implies that the distance + + align:start position:0% +know so this implies that the distance + + + align:start position:0% +know so this implies that the distance +from X to y + + align:start position:0% +from X to y + + + align:start position:0% +from X to y +is zero and therefore X is equal to + + align:start position:0% +is zero and therefore X is equal to + + + align:start position:0% +is zero and therefore X is equal to +Y which is what we've wanted to + + align:start position:0% +Y which is what we've wanted to + + + align:start position:0% +Y which is what we've wanted to +prove so notice that a lot of this used + + align:start position:0% +prove so notice that a lot of this used + + + align:start position:0% +prove so notice that a lot of this used +all the aoms that we were talking about + + align:start position:0% +all the aoms that we were talking about + + + align:start position:0% +all the aoms that we were talking about +in one point we use symmetry which + + align:start position:0% +in one point we use symmetry which + + + align:start position:0% +in one point we use symmetry which +wasn't too important but was useful to + + align:start position:0% +wasn't too important but was useful to + + + align:start position:0% +wasn't too important but was useful to +note so that we can swap X and and X + + align:start position:0% +note so that we can swap X and and X + + + align:start position:0% +note so that we can swap X and and X +around and apply the triangle inequality + + align:start position:0% +around and apply the triangle inequality + + + align:start position:0% +around and apply the triangle inequality +we apply the triangle inequality and we + + align:start position:0% +we apply the triangle inequality and we + + + align:start position:0% +we apply the triangle inequality and we +had to use positive definiteness so you + + align:start position:0% +had to use positive definiteness so you + + + align:start position:0% +had to use positive definiteness so you +know these are the Bare Bones of what we + + align:start position:0% +know these are the Bare Bones of what we + + + align:start position:0% +know these are the Bare Bones of what we +really need in the theory + + align:start position:0% +really need in the theory + + + align:start position:0% +really need in the theory +all + + align:start position:0% +all + + + align:start position:0% +all +right so now what we're going to do is + + align:start position:0% +right so now what we're going to do is + + + align:start position:0% +right so now what we're going to do is +show that not only do limit points exist + + align:start position:0% +show that not only do limit points exist + + + align:start position:0% +show that not only do limit points exist +nicely but the distances between limit + + align:start position:0% +nicely but the distances between limit + + + align:start position:0% +nicely but the distances between limit +points act + + align:start position:0% +points act + + + align:start position:0% +points act +nicely so to state that more clearly + + align:start position:0% +nicely so to state that more clearly + + + align:start position:0% +nicely so to state that more clearly +theorem let y be an + + align:start position:0% +theorem let y be an + + + align:start position:0% +theorem let y be an +X and xn converge to + + align:start position:0% +X and xn converge to + + + align:start position:0% +X and xn converge to +X + + align:start position:0% +X + + + align:start position:0% +X +then my claim is that the distance from + + align:start position:0% +then my claim is that the distance from + + + align:start position:0% +then my claim is that the distance from +xn to Y will converge from the distance + + align:start position:0% +xn to Y will converge from the distance + + + align:start position:0% +xn to Y will converge from the distance +from X to + + align:start position:0% +from X to + + + align:start position:0% +from X to +Y which makes relative sense but notice + + align:start position:0% +Y which makes relative sense but notice + + + align:start position:0% +Y which makes relative sense but notice +here the statement is slightly different + + align:start position:0% +here the statement is slightly different + + + align:start position:0% +here the statement is slightly different +before we were purely dealing with + + align:start position:0% +before we were purely dealing with + + + align:start position:0% +before we were purely dealing with +sequences of a metric + + align:start position:0% +sequences of a metric + + + align:start position:0% +sequences of a metric +space and so we had to deal with the + + align:start position:0% +space and so we had to deal with the + + + align:start position:0% +space and so we had to deal with the +metric D itself but when we're saying + + align:start position:0% +metric D itself but when we're saying + + + align:start position:0% +metric D itself but when we're saying +that this converges to dxy what space am + + align:start position:0% +that this converges to dxy what space am + + + align:start position:0% +that this converges to dxy what space am +I considering these distances + + align:start position:0% + + + + align:start position:0% + +in + + align:start position:0% + + + + align:start position:0% + +no no no worries it's the we're looking + + align:start position:0% +no no no worries it's the we're looking + + + align:start position:0% +no no no worries it's the we're looking +at it in R right because for every + + align:start position:0% +at it in R right because for every + + + align:start position:0% +at it in R right because for every +single n this is just a real number and + + align:start position:0% +single n this is just a real number and + + + align:start position:0% +single n this is just a real number and +so when I say the distance from X and to + + align:start position:0% +so when I say the distance from X and to + + + align:start position:0% +so when I say the distance from X and to +Y converges to the distance from X to Y + + align:start position:0% +Y converges to the distance from X to Y + + + align:start position:0% +Y converges to the distance from X to Y +I mean that this happens in ukian space + + align:start position:0% +I mean that this happens in ukian space + + + align:start position:0% +I mean that this happens in ukian space +and in fact you can likely I don't want + + align:start position:0% +and in fact you can likely I don't want + + + align:start position:0% +and in fact you can likely I don't want +to State explicitly but I'm pretty + + align:start position:0% +to State explicitly but I'm pretty + + + align:start position:0% +to State explicitly but I'm pretty +certain you can prove this as well in a + + align:start position:0% +certain you can prove this as well in a + + + align:start position:0% +certain you can prove this as well in a +general setting so between two metric + + align:start position:0% +general setting so between two metric + + + align:start position:0% +general setting so between two metric +spaces okay so let's prove + + align:start position:0% +spaces okay so let's prove + + + align:start position:0% +spaces okay so let's prove +this to do this we want to show + + align:start position:0% +this to do this we want to show + + + align:start position:0% +this to do this we want to show +ultimately + + align:start position:0% +ultimately + + + align:start position:0% +ultimately +we want to show that for all Epsilon + + align:start position:0% +we want to show that for all Epsilon + + + align:start position:0% +we want to show that for all Epsilon +bigger than + + align:start position:0% +bigger than + + + align:start position:0% +bigger than +zero there exists an n and the natural + + align:start position:0% +zero there exists an n and the natural + + + align:start position:0% +zero there exists an n and the natural +numbers such + + align:start position:0% +numbers such + + + align:start position:0% +numbers such +that the distance from X and to Y minus + + align:start position:0% +that the distance from X and to Y minus + + + align:start position:0% +that the distance from X and to Y minus +the distance from X to + + align:start position:0% +the distance from X to + + + align:start position:0% +the distance from X to +Y is less than Epsilon and absolute + + align:start position:0% +Y is less than Epsilon and absolute + + + align:start position:0% +Y is less than Epsilon and absolute +values and to do so we can just find an + + align:start position:0% +values and to do so we can just find an + + + align:start position:0% +values and to do so we can just find an +upper and lower bound on the distance + + align:start position:0% +upper and lower bound on the distance + + + align:start position:0% +upper and lower bound on the distance +from X to + + align:start position:0% +from X to + + + align:start position:0% +from X to +y or the distance from X and to Y so + + align:start position:0% +y or the distance from X and to Y so + + + align:start position:0% +y or the distance from X and to Y so +let's do that the first Direction + + align:start position:0% +let's do that the first Direction + + + align:start position:0% +let's do that the first Direction +is nice the distance from X to Y is less + + align:start position:0% +is nice the distance from X to Y is less + + + align:start position:0% +is nice the distance from X to Y is less +than or equal to by the triangle + + align:start position:0% +than or equal to by the triangle + + + align:start position:0% +than or equal to by the triangle +inequality the distance from xn to X + + align:start position:0% +inequality the distance from xn to X + + + align:start position:0% +inequality the distance from xn to X +plus the distance from X to + + align:start position:0% +plus the distance from X to + + + align:start position:0% +plus the distance from X to +Y and we can make this term arbitrarily + + align:start position:0% +Y and we can make this term arbitrarily + + + align:start position:0% +Y and we can make this term arbitrarily +small so uh I'm just going to choose the + + align:start position:0% +small so uh I'm just going to choose the + + + align:start position:0% +small so uh I'm just going to choose the +same end to be the one for this + + align:start position:0% +same end to be the one for this + + + align:start position:0% +same end to be the one for this +convergent sequence so this is less than + + align:start position:0% +convergent sequence so this is less than + + + align:start position:0% +convergent sequence so this is less than +Epsilon plus the distance from X to + + align:start position:0% +Epsilon plus the distance from X to + + + align:start position:0% +Epsilon plus the distance from X to +Y so this gives us the upper bound that + + align:start position:0% +Y so this gives us the upper bound that + + + align:start position:0% +Y so this gives us the upper bound that +we're wanting on the distance from X to + + align:start position:0% +we're wanting on the distance from X to + + + align:start position:0% +we're wanting on the distance from X to +Y let's prove the lower lower bound and + + align:start position:0% +Y let's prove the lower lower bound and + + + align:start position:0% +Y let's prove the lower lower bound and +the lower bound is very similar but it's + + align:start position:0% +the lower bound is very similar but it's + + + align:start position:0% +the lower bound is very similar but it's +just a slightly different manipulation + + align:start position:0% +just a slightly different manipulation + + + align:start position:0% +just a slightly different manipulation +where what we're then going to do so the + + align:start position:0% +where what we're then going to do so the + + + align:start position:0% +where what we're then going to do so the +distance from xn to + + align:start position:0% +distance from xn to + + + align:start position:0% +distance from xn to +Y uh actually you know I'll look at the + + align:start position:0% +Y uh actually you know I'll look at the + + + align:start position:0% +Y uh actually you know I'll look at the +distance from X to Y this is less than + + align:start position:0% +distance from X to Y this is less than + + + align:start position:0% +distance from X to Y this is less than +or equal to the distance from X to xn + + align:start position:0% +or equal to the distance from X to xn + + + align:start position:0% +or equal to the distance from X to xn +plus the distance + + align:start position:0% +plus the distance + + + align:start position:0% +plus the distance +from X to Y and then what we can do is + + align:start position:0% +from X to Y and then what we can do is + + + align:start position:0% +from X to Y and then what we can do is +subtract these terms so specifically + + align:start position:0% +subtract these terms so specifically + + + align:start position:0% +subtract these terms so specifically +we'll get that the distance from X to Y + + align:start position:0% +we'll get that the distance from X to Y + + + align:start position:0% +we'll get that the distance from X to Y +minus the distance from X to xn + + align:start position:0% + + + + align:start position:0% + +xn is less than or equal to the distance + + align:start position:0% +xn is less than or equal to the distance + + + align:start position:0% +xn is less than or equal to the distance +from X to + + align:start position:0% +from X to + + + align:start position:0% +from X to +Y and we can make this term arbitrarily + + align:start position:0% +Y and we can make this term arbitrarily + + + align:start position:0% +Y and we can make this term arbitrarily +small so this is less than the distance + + align:start position:0% +small so this is less than the distance + + + align:start position:0% +small so this is less than the distance +from X to + + align:start position:0% +from X to + + + align:start position:0% +from X to +Y minus Epsilon and notice that this + + align:start position:0% +Y minus Epsilon and notice that this + + + align:start position:0% +Y minus Epsilon and notice that this +implies the result because then we have + + align:start position:0% +implies the result because then we have + + + align:start position:0% +implies the result because then we have +that the distance from xn to Y is less + + align:start position:0% +that the distance from xn to Y is less + + + align:start position:0% +that the distance from xn to Y is less +oh shoot did I do I get this wrong + + align:start position:0% +oh shoot did I do I get this wrong + + + align:start position:0% +oh shoot did I do I get this wrong +uh no no okay yeah so then the distance + + align:start position:0% +uh no no okay yeah so then the distance + + + align:start position:0% +uh no no okay yeah so then the distance +from xn to Y is less + + align:start position:0% +from xn to Y is less + + + align:start position:0% +from xn to Y is less +than sorry this should be the distance + + align:start position:0% +than sorry this should be the distance + + + align:start position:0% +than sorry this should be the distance +from X to Y there we go the distance + + align:start position:0% +from X to Y there we go the distance + + + align:start position:0% +from X to Y there we go the distance +from xn + + align:start position:0% +from xn + + + align:start position:0% +from xn +to let me double check this distance + + align:start position:0% +to let me double check this distance + + + align:start position:0% +to let me double check this distance +from xn to Y + + align:start position:0% +from xn to Y + + + align:start position:0% +from xn to Y +plus + + align:start position:0% +plus + + + align:start position:0% +plus +xn 2 y there we go sorry about that I I + + align:start position:0% +xn 2 y there we go sorry about that I I + + + align:start position:0% +xn 2 y there we go sorry about that I I +mixed up what they were converging + + align:start position:0% +mixed up what they were converging + + + align:start position:0% +mixed up what they were converging +to so what this tells us is that the + + align:start position:0% +to so what this tells us is that the + + + align:start position:0% +to so what this tells us is that the +distance from X into y minus the + + align:start position:0% +distance from X into y minus the + + + align:start position:0% +distance from X into y minus the +distance from X to Y gets arbitrarily + + align:start position:0% +distance from X to Y gets arbitrarily + + + align:start position:0% +distance from X to Y gets arbitrarily +small right I can write that out if + + align:start position:0% +small right I can write that out if + + + align:start position:0% +small right I can write that out if +y'all would prefer uh but that's just + + align:start position:0% +y'all would prefer uh but that's just + + + align:start position:0% +y'all would prefer uh but that's just +the next step you write it in terms of + + align:start position:0% +the next step you write it in terms of + + + align:start position:0% +the next step you write it in terms of +the absolute + + align:start position:0% +the absolute + + + align:start position:0% +the absolute +values okay any + + align:start position:0% +values okay any + + + align:start position:0% +values okay any +questions so not only do limit points be + + align:start position:0% +questions so not only do limit points be + + + align:start position:0% +questions so not only do limit points be +not only are limit points unique but the + + align:start position:0% +not only are limit points unique but the + + + align:start position:0% +not only are limit points unique but the +distances between limit points are also + + align:start position:0% +distances between limit points are also + + + align:start position:0% +distances between limit points are also +going to be unique at least in the real + + align:start position:0% +going to be unique at least in the real + + + align:start position:0% +going to be unique at least in the real +number sense which is pretty nice uh + + align:start position:0% +number sense which is pretty nice uh + + + align:start position:0% +number sense which is pretty nice uh +I'll remark one proposition which is + + align:start position:0% +I'll remark one proposition which is + + + align:start position:0% +I'll remark one proposition which is +pretty interesting + + align:start position:0% +pretty interesting + + + align:start position:0% +pretty interesting +you can study this for two convergent + + align:start position:0% +you can study this for two convergent + + + align:start position:0% +you can study this for two convergent +sequences at once so + + align:start position:0% + + + + align:start position:0% + +suppose or I I'll State this in two + + align:start position:0% +suppose or I I'll State this in two + + + align:start position:0% +suppose or I I'll State this in two +parts suppose xn converges to X and Y N + + align:start position:0% +parts suppose xn converges to X and Y N + + + align:start position:0% +parts suppose xn converges to X and Y N +converges to + + align:start position:0% +converges to + + + align:start position:0% +converges to +Y then the distance from xn to + + align:start position:0% +Y then the distance from xn to + + + align:start position:0% +Y then the distance from xn to +YN converges to the distance from X to + + align:start position:0% +YN converges to the distance from X to + + + align:start position:0% +YN converges to the distance from X to +Y this relatively makes sense but we can + + align:start position:0% +Y this relatively makes sense but we can + + + align:start position:0% +Y this relatively makes sense but we can +also State this slightly differently or + + align:start position:0% +also State this slightly differently or + + + align:start position:0% +also State this slightly differently or +a different type of this theorem + + align:start position:0% +a different type of this theorem + + + align:start position:0% +a different type of this theorem +suppose xn and YN are koshy so they're + + align:start position:0% +suppose xn and YN are koshy so they're + + + align:start position:0% +suppose xn and YN are koshy so they're +koshy sequences so they get arbitrarily + + align:start position:0% +koshy sequences so they get arbitrarily + + + align:start position:0% +koshy sequences so they get arbitrarily +closed together but don't necessarily + + align:start position:0% +closed together but don't necessarily + + + align:start position:0% +closed together but don't necessarily +have a limit + + align:start position:0% +have a limit + + + align:start position:0% +have a limit +point then we know that the distance + + align:start position:0% +point then we know that the distance + + + align:start position:0% +point then we know that the distance +from xn to + + align:start position:0% +from xn to + + + align:start position:0% +from xn to +YN + + align:start position:0% + + + + align:start position:0% + +converges notice that I'm not saying + + align:start position:0% +converges notice that I'm not saying + + + align:start position:0% +converges notice that I'm not saying +that I'm not saying what it converges to + + align:start position:0% +that I'm not saying what it converges to + + + align:start position:0% +that I'm not saying what it converges to +I don't know that Koshi sequences have + + align:start position:0% +I don't know that Koshi sequences have + + + align:start position:0% +I don't know that Koshi sequences have +limit points in my metric space + + align:start position:0% +limit points in my metric space + + + align:start position:0% +limit points in my metric space +uh and I'll get back to that in a moment + + align:start position:0% +uh and I'll get back to that in a moment + + + align:start position:0% +uh and I'll get back to that in a moment +but nonetheless the sequence itself in + + align:start position:0% +but nonetheless the sequence itself in + + + align:start position:0% +but nonetheless the sequence itself in +the real numbers will converge and that + + align:start position:0% +the real numbers will converge and that + + + align:start position:0% +the real numbers will converge and that +uses the fact that the real numbers is + + align:start position:0% +uses the fact that the real numbers is + + + align:start position:0% +uses the fact that the real numbers is +Koshi + + align:start position:0% +Koshi + + + align:start position:0% +Koshi +complete now I'm not going to prove + + align:start position:0% +complete now I'm not going to prove + + + align:start position:0% +complete now I'm not going to prove +these two facts these are facts that are + + align:start position:0% +these two facts these are facts that are + + + align:start position:0% +these two facts these are facts that are +uh on your problem set but I do want to + + align:start position:0% +uh on your problem set but I do want to + + + align:start position:0% +uh on your problem set but I do want to +point out because this happened a lot + + align:start position:0% +point out because this happened a lot + + + align:start position:0% +point out because this happened a lot +last year you cannot assume that the + + align:start position:0% +last year you cannot assume that the + + + align:start position:0% +last year you cannot assume that the +limit points in the second part exist + + align:start position:0% +limit points in the second part exist + + + align:start position:0% +limit points in the second part exist +you can know that this implication + + align:start position:0% +you can know that this implication + + + align:start position:0% +you can know that this implication +implies the top one by uniqueness + + align:start position:0% +implies the top one by uniqueness + + + align:start position:0% +implies the top one by uniqueness +because convergent sequences are koshy + + align:start position:0% +because convergent sequences are koshy + + + align:start position:0% +because convergent sequences are koshy +as we're going to prove right now um so + + align:start position:0% +as we're going to prove right now um so + + + align:start position:0% +as we're going to prove right now um so +if you prove the second one first then + + align:start position:0% +if you prove the second one first then + + + align:start position:0% +if you prove the second one first then +you can make a small remark you have to + + align:start position:0% +you can make a small remark you have to + + + align:start position:0% +you can make a small remark you have to +explain why the limit point is the + + align:start position:0% +explain why the limit point is the + + + align:start position:0% +explain why the limit point is the +distance from X to Y but that's not too + + align:start position:0% +distance from X to Y but that's not too + + + align:start position:0% +distance from X to Y but that's not too +bad + + align:start position:0% +bad + + + align:start position:0% +bad +so let's prove that + + align:start position:0% +so let's prove that + + + align:start position:0% +so let's prove that +theorem uh is that the next theorem I + + align:start position:0% +theorem uh is that the next theorem I + + + align:start position:0% +theorem uh is that the next theorem I +wanted to + + align:start position:0% + + + + align:start position:0% + +say + + align:start position:0% + + + + align:start position:0% + +uh yeah I'll do that one + + align:start position:0% +uh yeah I'll do that one + + + align:start position:0% +uh yeah I'll do that one +now Koshi sequences + + align:start position:0% + + + + align:start position:0% + +oh sorry convergent + + align:start position:0% + + + + align:start position:0% + +sequences + + align:start position:0% +sequences + + + align:start position:0% +sequences +sequences are kosi + + align:start position:0% + + + + align:start position:0% + +sequences + + align:start position:0% +sequences + + + align:start position:0% +sequences +proof + + align:start position:0% +proof + + + align:start position:0% +proof +suppose xn is the convergent sequence + + align:start position:0% +suppose xn is the convergent sequence + + + align:start position:0% +suppose xn is the convergent sequence +we're considering and that xn converges + + align:start position:0% +we're considering and that xn converges + + + align:start position:0% +we're considering and that xn converges +to + + align:start position:0% +to + + + align:start position:0% +to +X then we know that and I'm going to + + align:start position:0% +X then we know that and I'm going to + + + align:start position:0% +X then we know that and I'm going to +State this over and over again just like + + align:start position:0% +State this over and over again just like + + + align:start position:0% +State this over and over again just like +we do in real analysis but at a certain + + align:start position:0% +we do in real analysis but at a certain + + + align:start position:0% +we do in real analysis but at a certain +point it just BEC secondhand nature uh + + align:start position:0% +point it just BEC secondhand nature uh + + + align:start position:0% +point it just BEC secondhand nature uh +so therefore for all Epson bigger than + + align:start position:0% +so therefore for all Epson bigger than + + + align:start position:0% +so therefore for all Epson bigger than +zero there exists n in the natural + + align:start position:0% +zero there exists n in the natural + + + align:start position:0% +zero there exists n in the natural +numbers such + + align:start position:0% +numbers such + + + align:start position:0% +numbers such +that uh the uh such that for all n + + align:start position:0% +that uh the uh such that for all n + + + align:start position:0% +that uh the uh such that for all n +bigger than or equal to n the distance + + align:start position:0% +bigger than or equal to n the distance + + + align:start position:0% +bigger than or equal to n the distance +from xn to X is less than Epsilon so + + align:start position:0% +from xn to X is less than Epsilon so + + + align:start position:0% +from xn to X is less than Epsilon so +what does this tell us well what we're + + align:start position:0% +what does this tell us well what we're + + + align:start position:0% +what does this tell us well what we're +ultimately interested in is the distance + + align:start position:0% +ultimately interested in is the distance + + + align:start position:0% +ultimately interested in is the distance +from xn to XM right + + align:start position:0% +from xn to XM right + + + align:start position:0% +from xn to XM right +let M be bigger than or equal to n what + + align:start position:0% +let M be bigger than or equal to n what + + + align:start position:0% +let M be bigger than or equal to n what +we're interested in is the distance from + + align:start position:0% +we're interested in is the distance from + + + align:start position:0% +we're interested in is the distance from +X and to XM to state that it's a Koshi + + align:start position:0% +X and to XM to state that it's a Koshi + + + align:start position:0% +X and to XM to state that it's a Koshi +sequence so what can we + + align:start position:0% +sequence so what can we + + + align:start position:0% +sequence so what can we +do + + align:start position:0% + + + + align:start position:0% + +anyone sort + + align:start position:0% +anyone sort + + + align:start position:0% +anyone sort +of want yall to think about it because + + align:start position:0% +of want yall to think about it because + + + align:start position:0% +of want yall to think about it because +there's we want to bound this and show + + align:start position:0% +there's we want to bound this and show + + + align:start position:0% +there's we want to bound this and show +that this is less than + + align:start position:0% + + + + align:start position:0% + +Epsilon exactly the triangle inequality + + align:start position:0% +Epsilon exactly the triangle inequality + + + align:start position:0% +Epsilon exactly the triangle inequality +this is less than or equal to the + + align:start position:0% +this is less than or equal to the + + + align:start position:0% +this is less than or equal to the +distance from xn to X plus the distance + + align:start position:0% +distance from xn to X plus the distance + + + align:start position:0% +distance from xn to X plus the distance +from X or X to + + align:start position:0% +from X or X to + + + align:start position:0% +from X or X to +XM and we can make both of these less + + align:start position:0% +XM and we can make both of these less + + + align:start position:0% +XM and we can make both of these less +than + + align:start position:0% + + + + align:start position:0% + +Epsilon now if I was really careful I + + align:start position:0% +Epsilon now if I was really careful I + + + align:start position:0% +Epsilon now if I was really careful I +could have made these epsilons over two + + align:start position:0% +could have made these epsilons over two + + + align:start position:0% +could have made these epsilons over two +and then this would have been exactly + + align:start position:0% +and then this would have been exactly + + + align:start position:0% +and then this would have been exactly +Epsilon most of the time if you show + + align:start position:0% +Epsilon most of the time if you show + + + align:start position:0% +Epsilon most of the time if you show +it's less than a constant time Epsilon + + align:start position:0% +it's less than a constant time Epsilon + + + align:start position:0% +it's less than a constant time Epsilon +you're good you would just have to + + align:start position:0% +you're good you would just have to + + + align:start position:0% +you're good you would just have to +relabel things so all good things here + + align:start position:0% +relabel things so all good things here + + + align:start position:0% +relabel things so all good things here +but yeah exactly you apply the triangle + + align:start position:0% +but yeah exactly you apply the triangle + + + align:start position:0% +but yeah exactly you apply the triangle +inequality and notice oh and then this + + align:start position:0% +inequality and notice oh and then this + + + align:start position:0% +inequality and notice oh and then this +is precisely what we want for a Koshi + + align:start position:0% +is precisely what we want for a Koshi + + + align:start position:0% +is precisely what we want for a Koshi +sequence right this implies that it is + + align:start position:0% +sequence right this implies that it is + + + align:start position:0% +sequence right this implies that it is +in fact a koshy + + align:start position:0% +in fact a koshy + + + align:start position:0% +in fact a koshy +sequence so we're + + align:start position:0% +sequence so we're + + + align:start position:0% +sequence so we're +done uh now the real question is if + + align:start position:0% +done uh now the real question is if + + + align:start position:0% +done uh now the real question is if +koshy sequences are convergent sequences + + align:start position:0% +koshy sequences are convergent sequences + + + align:start position:0% +koshy sequences are convergent sequences +and as we know from the real numbers + + align:start position:0% +and as we know from the real numbers + + + align:start position:0% +and as we know from the real numbers +this is not always or from the real + + align:start position:0% +this is not always or from the real + + + align:start position:0% +this is not always or from the real +numbers we know that there it's Koshi + + align:start position:0% +numbers we know that there it's Koshi + + + align:start position:0% +numbers we know that there it's Koshi +complete but here we don't and what do I + + align:start position:0% +complete but here we don't and what do I + + + align:start position:0% +complete but here we don't and what do I +mean by Koshi complete which I've stated + + align:start position:0% +mean by Koshi complete which I've stated + + + align:start position:0% +mean by Koshi complete which I've stated +a few times + + align:start position:0% +a few times + + + align:start position:0% +a few times +definition a + + align:start position:0% +definition a + + + align:start position:0% +definition a +space is Koshi + + align:start position:0% + + + + align:start position:0% + +complete if and only if I.E the + + align:start position:0% +complete if and only if I.E the + + + align:start position:0% +complete if and only if I.E the +definition uh the Koshi + + align:start position:0% + + + + align:start position:0% + +sequences are + + align:start position:0% + + + + align:start position:0% + +convergent so this is the definition of + + align:start position:0% +convergent so this is the definition of + + + align:start position:0% +convergent so this is the definition of +what Koshi complete actually means and + + align:start position:0% +what Koshi complete actually means and + + + align:start position:0% +what Koshi complete actually means and +this is a very powerful fact right we + + align:start position:0% +this is a very powerful fact right we + + + align:start position:0% +this is a very powerful fact right we +use Co completeness everywhere in real + + align:start position:0% +use Co completeness everywhere in real + + + align:start position:0% +use Co completeness everywhere in real +analysis to state that limit points + + align:start position:0% +analysis to state that limit points + + + align:start position:0% +analysis to state that limit points +exist to state that differentiability + + align:start position:0% +exist to state that differentiability + + + align:start position:0% +exist to state that differentiability +was nice things like that we we needed + + align:start position:0% +was nice things like that we we needed + + + align:start position:0% +was nice things like that we we needed +Koshi completeness there now not every + + align:start position:0% +Koshi completeness there now not every + + + align:start position:0% +Koshi completeness there now not every +space is Koshi complete unfortunately + + align:start position:0% +space is Koshi complete unfortunately + + + align:start position:0% +space is Koshi complete unfortunately +but the ones that we really want them to + + align:start position:0% +but the ones that we really want them to + + + align:start position:0% +but the ones that we really want them to +be are in fact so uh proposition this is + + align:start position:0% +be are in fact so uh proposition this is + + + align:start position:0% +be are in fact so uh proposition this is +on your + + align:start position:0% +on your + + + align:start position:0% +on your +homework we have + + align:start position:0% +homework we have + + + align:start position:0% +homework we have +that + + align:start position:0% +that + + + align:start position:0% +that +yeah the set of continuous functions on + + align:start position:0% +yeah the set of continuous functions on + + + align:start position:0% +yeah the set of continuous functions on +0 to one is Koshi complete + + align:start position:0% + + + + align:start position:0% + +this is a statement on your homework + + align:start position:0% +this is a statement on your homework + + + align:start position:0% +this is a statement on your homework +that I've broken up into individual + + align:start position:0% +that I've broken up into individual + + + align:start position:0% +that I've broken up into individual +steps so they should be a little bit + + align:start position:0% +steps so they should be a little bit + + + align:start position:0% +steps so they should be a little bit +nicer um but yeah a very useful + + align:start position:0% +nicer um but yeah a very useful + + + align:start position:0% +nicer um but yeah a very useful +proposition to show okay now let me go + + align:start position:0% +proposition to show okay now let me go + + + align:start position:0% +proposition to show okay now let me go +back to what I meant to do slightly + + align:start position:0% +back to what I meant to do slightly + + + align:start position:0% +back to what I meant to do slightly +earlier okay we have a few more things + + align:start position:0% +earlier okay we have a few more things + + + align:start position:0% +earlier okay we have a few more things +to say about uh Co convergent sequences + + align:start position:0% +to say about uh Co convergent sequences + + + align:start position:0% +to say about uh Co convergent sequences +and to do so I'm going to Define what it + + align:start position:0% +and to do so I'm going to Define what it + + + align:start position:0% +and to do so I'm going to Define what it +means for a set to be bounded right when + + align:start position:0% +means for a set to be bounded right when + + + align:start position:0% +means for a set to be bounded right when +we were looking at real analysis one of + + align:start position:0% +we were looking at real analysis one of + + + align:start position:0% +we were looking at real analysis one of +the most useful theorems we had in our + + align:start position:0% +the most useful theorems we had in our + + + align:start position:0% +the most useful theorems we had in our +tool belt was the bosano virus drust + + align:start position:0% +tool belt was the bosano virus drust + + + align:start position:0% +tool belt was the bosano virus drust +theorem now we're not going to have an + + align:start position:0% +theorem now we're not going to have an + + + align:start position:0% +theorem now we're not going to have an +analog of it but we still have some + + align:start position:0% +analog of it but we still have some + + + align:start position:0% +analog of it but we still have some +statements akin to it that we want to + + align:start position:0% +statements akin to it that we want to + + + align:start position:0% +statements akin to it that we want to +show uh and this will be especially + + align:start position:0% +show uh and this will be especially + + + align:start position:0% +show uh and this will be especially +important as we build up to compact + + align:start position:0% +important as we build up to compact + + + align:start position:0% +important as we build up to compact +sets so + + align:start position:0% +sets so + + + align:start position:0% +sets so +definition a sequence + + align:start position:0% +definition a sequence + + + align:start position:0% +definition a sequence +xn is + + align:start position:0% + + + + align:start position:0% + +bounded by let's say B bigger than zero + + align:start position:0% +bounded by let's say B bigger than zero + + + align:start position:0% +bounded by let's say B bigger than zero +if for all n in the natural + + align:start position:0% +if for all n in the natural + + + align:start position:0% +if for all n in the natural +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +uh oh sorry I should + + align:start position:0% + + + + align:start position:0% + +say if there exists a point p in your + + align:start position:0% +say if there exists a point p in your + + + align:start position:0% +say if there exists a point p in your +metrics base such that for all n and the + + align:start position:0% +metrics base such that for all n and the + + + align:start position:0% +metrics base such that for all n and the +natural + + align:start position:0% +natural + + + align:start position:0% +natural +numbers the distance from + + align:start position:0% +numbers the distance from + + + align:start position:0% +numbers the distance from +xn to P is less than b which is what we + + align:start position:0% +xn to P is less than b which is what we + + + align:start position:0% +xn to P is less than b which is what we +would expect we want the convergent we + + align:start position:0% +would expect we want the convergent we + + + align:start position:0% +would expect we want the convergent we +want the sequence itself to to be the + + align:start position:0% +want the sequence itself to to be the + + + align:start position:0% +want the sequence itself to to be the +distance between the point and your + + align:start position:0% +distance between the point and your + + + align:start position:0% +distance between the point and your +sequence to be bounded that's what it + + align:start position:0% +sequence to be bounded that's what it + + + align:start position:0% +sequence to be bounded that's what it +means for a sequence to be + + align:start position:0% +means for a sequence to be + + + align:start position:0% +means for a sequence to be +bounded and if you want to picture this + + align:start position:0% +bounded and if you want to picture this + + + align:start position:0% +bounded and if you want to picture this +uh you can I always like to draw little + + align:start position:0% +uh you can I always like to draw little + + + align:start position:0% +uh you can I always like to draw little +pictures in my notes about this if this + + align:start position:0% +pictures in my notes about this if this + + + align:start position:0% +pictures in my notes about this if this +is our metric base X here's our Point p + + align:start position:0% +is our metric base X here's our Point p + + + align:start position:0% +is our metric base X here's our Point p +and what this is stating is that there + + align:start position:0% +and what this is stating is that there + + + align:start position:0% +and what this is stating is that there +exists a radius large + + align:start position:0% +exists a radius large + + + align:start position:0% +exists a radius large +enough of radius R sorry not R of radius + + align:start position:0% +enough of radius R sorry not R of radius + + + align:start position:0% +enough of radius R sorry not R of radius +B such that it completely contains X + + align:start position:0% +B such that it completely contains X + + + align:start position:0% +B such that it completely contains X +now granted what does it mean to have + + align:start position:0% +now granted what does it mean to have + + + align:start position:0% +now granted what does it mean to have +stuff outside of X nothing really so + + align:start position:0% +stuff outside of X nothing really so + + + align:start position:0% +stuff outside of X nothing really so +really we just mean the + + align:start position:0% +really we just mean the + + + align:start position:0% +really we just mean the +region in the middle is contained in the + + align:start position:0% +region in the middle is contained in the + + + align:start position:0% +region in the middle is contained in the +ball of radius r or radius B but that's + + align:start position:0% +ball of radius r or radius B but that's + + + align:start position:0% +ball of radius r or radius B but that's +a nice picture if you prefer and not + + align:start position:0% +a nice picture if you prefer and not + + + align:start position:0% +a nice picture if you prefer and not +only can we say this about convergent + + align:start position:0% +only can we say this about convergent + + + align:start position:0% +only can we say this about convergent +sequences or sorry not only can we say + + align:start position:0% +sequences or sorry not only can we say + + + align:start position:0% +sequences or sorry not only can we say +this about sequences in general we can + + align:start position:0% +this about sequences in general we can + + + align:start position:0% +this about sequences in general we can +also Define what this means for a + + align:start position:0% +also Define what this means for a + + + align:start position:0% +also Define what this means for a +set a + + align:start position:0% +set a + + + align:start position:0% +set a +set a in + + align:start position:0% +set a in + + + align:start position:0% +set a in +X is bounded + + align:start position:0% +X is bounded + + + align:start position:0% +X is bounded +by + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% +B + + + align:start position:0% +B +if for + + align:start position:0% +if for + + + align:start position:0% +if for +all p in X oh sorry if there exists a p + + align:start position:0% +all p in X oh sorry if there exists a p + + + align:start position:0% +all p in X oh sorry if there exists a p +in X such that for all a and + + align:start position:0% +in X such that for all a and + + + align:start position:0% +in X such that for all a and +a the distance from a to + + align:start position:0% +a the distance from a to + + + align:start position:0% +a the distance from a to +P is less than + + align:start position:0% +P is less than + + + align:start position:0% +P is less than +b does the uh set theory notation that + + align:start position:0% +b does the uh set theory notation that + + + align:start position:0% +b does the uh set theory notation that +I'm using make sense to everyone there + + align:start position:0% +I'm using make sense to everyone there + + + align:start position:0% +I'm using make sense to everyone there +exists in for all cool so this is what + + align:start position:0% +exists in for all cool so this is what + + + align:start position:0% +exists in for all cool so this is what +it means for a sequence and a set to be + + align:start position:0% +it means for a sequence and a set to be + + + align:start position:0% +it means for a sequence and a set to be +bounded why do I bring this up because + + align:start position:0% +bounded why do I bring this up because + + + align:start position:0% +bounded why do I bring this up because +convergent sequences are bounded + + align:start position:0% +convergent sequences are bounded + + + align:start position:0% +convergent sequences are bounded +sequences we have this from real + + align:start position:0% +sequences we have this from real + + + align:start position:0% +sequences we have this from real +analysis but I'm going to prove it now + + align:start position:0% +analysis but I'm going to prove it now + + + align:start position:0% +analysis but I'm going to prove it now +in metric + + align:start position:0% +in metric + + + align:start position:0% +in metric +baces so + + align:start position:0% + + + + align:start position:0% + +proposition or I should I'll just write + + align:start position:0% +proposition or I should I'll just write + + + align:start position:0% +proposition or I should I'll just write +it out how I've been writing out the + + align:start position:0% +it out how I've been writing out the + + + align:start position:0% +it out how I've been writing out the +other ones if xn converges to X then + + align:start position:0% + + + + align:start position:0% + +xn is a bounded sequence + + align:start position:0% + + + + align:start position:0% + +okay let's start off with the proof + + align:start position:0% +okay let's start off with the proof + + + align:start position:0% +okay let's start off with the proof +which we'll start off as all of our + + align:start position:0% +which we'll start off as all of our + + + align:start position:0% +which we'll start off as all of our +statements have so far with the + + align:start position:0% +statements have so far with the + + + align:start position:0% +statements have so far with the +statement of what uh of what convergence + + align:start position:0% +statement of what uh of what convergence + + + align:start position:0% +statement of what uh of what convergence +means and the statement of what + + align:start position:0% +means and the statement of what + + + align:start position:0% +means and the statement of what +convergence means I'm going to choose + + align:start position:0% +convergence means I'm going to choose + + + align:start position:0% +convergence means I'm going to choose +the Epsilon that I want so that I'm not + + align:start position:0% +the Epsilon that I want so that I'm not + + + align:start position:0% +the Epsilon that I want so that I'm not +dealing with all the possible epsilons + + align:start position:0% +dealing with all the possible epsilons + + + align:start position:0% +dealing with all the possible epsilons +so I'm going to + + align:start position:0% +so I'm going to + + + align:start position:0% +so I'm going to +note for Epsilon equal to one bigger + + align:start position:0% +note for Epsilon equal to one bigger + + + align:start position:0% +note for Epsilon equal to one bigger +than zero we know that there exists an n + + align:start position:0% +than zero we know that there exists an n + + + align:start position:0% +than zero we know that there exists an n +in the natural + + align:start position:0% +in the natural + + + align:start position:0% +in the natural +numbers such that the distance from such + + align:start position:0% +numbers such that the distance from such + + + align:start position:0% +numbers such that the distance from such +that for + + align:start position:0% +that for + + + align:start position:0% +that for +all n bigger than or equal to + + align:start position:0% +all n bigger than or equal to + + + align:start position:0% +all n bigger than or equal to +n the distance from xn to X is less than + + align:start position:0% +n the distance from xn to X is less than + + + align:start position:0% +n the distance from xn to X is less than +Epsilon which again I'm assuming is + + align:start position:0% +Epsilon which again I'm assuming is + + + align:start position:0% +Epsilon which again I'm assuming is +one now does this complete our statement + + align:start position:0% +one now does this complete our statement + + + align:start position:0% +one now does this complete our statement +the answer is no here we only have that + + align:start position:0% +the answer is no here we only have that + + + align:start position:0% +the answer is no here we only have that +this is true for all n bigger than or + + align:start position:0% +this is true for all n bigger than or + + + align:start position:0% +this is true for all n bigger than or +equal to capital N right but what we + + align:start position:0% +equal to capital N right but what we + + + align:start position:0% +equal to capital N right but what we +want for our + + align:start position:0% +want for our + + + align:start position:0% +want for our +statement is to to show that for every + + align:start position:0% +statement is to to show that for every + + + align:start position:0% +statement is to to show that for every +single natural number this sequence is + + align:start position:0% +single natural number this sequence is + + + align:start position:0% +single natural number this sequence is +bounded but this isn't an issue because + + align:start position:0% +bounded but this isn't an issue because + + + align:start position:0% +bounded but this isn't an issue because +what we can note is that there are + + align:start position:0% +what we can note is that there are + + + align:start position:0% +what we can note is that there are +finitely many terms less than n in the + + align:start position:0% +finitely many terms less than n in the + + + align:start position:0% +finitely many terms less than n in the +natural numbers right so what we can + + align:start position:0% +natural numbers right so what we can + + + align:start position:0% +natural numbers right so what we can +do is that + + align:start position:0% +do is that + + + align:start position:0% +do is that +b be the maximum of the finitely many + + align:start position:0% +b be the maximum of the finitely many + + + align:start position:0% +b be the maximum of the finitely many +terms of the distance from x i tox or + + align:start position:0% +terms of the distance from x i tox or + + + align:start position:0% +terms of the distance from x i tox or +let's say uh + + align:start position:0% +let's say uh + + + align:start position:0% +let's say uh +or + + align:start position:0% +or + + + align:start position:0% +or +one for I between 1 and capital + + align:start position:0% +one for I between 1 and capital + + + align:start position:0% +one for I between 1 and capital +N so what I'm doing here is I'm noting + + align:start position:0% +N so what I'm doing here is I'm noting + + + align:start position:0% +N so what I'm doing here is I'm noting +that here I have my convergent + + align:start position:0% + + + + align:start position:0% + +sequence I know that most of them in + + align:start position:0% +sequence I know that most of them in + + + align:start position:0% +sequence I know that most of them in +fact infinitely many of them are + + align:start position:0% +fact infinitely many of them are + + + align:start position:0% +fact infinitely many of them are +contained uh are contained in a ball of + + align:start position:0% +contained uh are contained in a ball of + + + align:start position:0% +contained uh are contained in a ball of +radius + + align:start position:0% +radius + + + align:start position:0% +radius +one and I only have finitely many terms + + align:start position:0% +one and I only have finitely many terms + + + align:start position:0% +one and I only have finitely many terms +outside of that ball + + align:start position:0% +outside of that ball + + + align:start position:0% +outside of that ball +so what I'm doing is I'm saying okay + + align:start position:0% +so what I'm doing is I'm saying okay + + + align:start position:0% +so what I'm doing is I'm saying okay +well it's either in this ball or the + + align:start position:0% +well it's either in this ball or the + + + align:start position:0% +well it's either in this ball or the +next one or the next one or so on and so + + align:start position:0% +next one or the next one or so on and so + + + align:start position:0% +next one or the next one or so on and so +forth this is what the statement is that + + align:start position:0% +forth this is what the statement is that + + + align:start position:0% +forth this is what the statement is that +we wanted to show and we know that this + + align:start position:0% +we wanted to show and we know that this + + + align:start position:0% +we wanted to show and we know that this +is in fact + + align:start position:0% +is in fact + + + align:start position:0% +is in fact +finite as there was only finitely many + + align:start position:0% +finite as there was only finitely many + + + align:start position:0% +finite as there was only finitely many +terms so this is the B that it's bounded + + align:start position:0% +terms so this is the B that it's bounded + + + align:start position:0% +terms so this is the B that it's bounded +by I can write that out some more if + + align:start position:0% +by I can write that out some more if + + + align:start position:0% +by I can write that out some more if +yall would prefer but this is + + align:start position:0% +yall would prefer but this is + + + align:start position:0% +yall would prefer but this is +essentially the + + align:start position:0% +essentially the + + + align:start position:0% +essentially the +statement + + align:start position:0% +statement + + + align:start position:0% +statement +cool uh so + + align:start position:0% +cool uh so + + + align:start position:0% +cool uh so +I think that's mostly oh there's one + + align:start position:0% +I think that's mostly oh there's one + + + align:start position:0% +I think that's mostly oh there's one +more thing we want to say about + + align:start position:0% +more thing we want to say about + + + align:start position:0% +more thing we want to say about +convergent + + align:start position:0% +convergent + + + align:start position:0% +convergent +sequences which is that their + + align:start position:0% +sequences which is that their + + + align:start position:0% +sequences which is that their +subsequences act nicely which will be + + align:start position:0% +subsequences act nicely which will be + + + align:start position:0% +subsequences act nicely which will be +essentially how we want it to be um + + align:start position:0% +essentially how we want it to be um + + + align:start position:0% +essentially how we want it to be um +so + + align:start position:0% + + + + align:start position:0% + +proposition let xn converge to + + align:start position:0% +proposition let xn converge to + + + align:start position:0% +proposition let xn converge to +X and xn + + align:start position:0% +X and xn + + + align:start position:0% +X and xn +K be a + + align:start position:0% + + + + align:start position:0% + +subsequence of xn + + align:start position:0% + + + + align:start position:0% + +then my + + align:start position:0% +then my + + + align:start position:0% +then my +claim is that xn + + align:start position:0% +claim is that xn + + + align:start position:0% +claim is that xn +K is + + align:start position:0% + + + + align:start position:0% + +convergent and in fact to show that it's + + align:start position:0% +convergent and in fact to show that it's + + + align:start position:0% +convergent and in fact to show that it's +convergent we're going to show that it + + align:start position:0% +convergent we're going to show that it + + + align:start position:0% +convergent we're going to show that it +converges to X right which is what we + + align:start position:0% +converges to X right which is what we + + + align:start position:0% +converges to X right which is what we +should expect of a subsequence does + + align:start position:0% +should expect of a subsequence does + + + align:start position:0% +should expect of a subsequence does +everyone here know what a subsequence is + + align:start position:0% +everyone here know what a subsequence is + + + align:start position:0% +everyone here know what a subsequence is +happy to redefine + + align:start position:0% +happy to redefine + + + align:start position:0% +happy to redefine +um cool um so let's go with the + + align:start position:0% +um cool um so let's go with the + + + align:start position:0% +um cool um so let's go with the +statement so proof notice that my + + align:start position:0% +statement so proof notice that my + + + align:start position:0% +statement so proof notice that my +subsequence here is arbitrary I'm not + + align:start position:0% +subsequence here is arbitrary I'm not + + + align:start position:0% +subsequence here is arbitrary I'm not +going to rewrite that out but we could + + align:start position:0% +going to rewrite that out but we could + + + align:start position:0% +going to rewrite that out but we could +choose any subsequence of our sequence + + align:start position:0% +choose any subsequence of our sequence + + + align:start position:0% +choose any subsequence of our sequence +and what we're interested in is we want + + align:start position:0% +and what we're interested in is we want + + + align:start position:0% +and what we're interested in is we want +to show for all Epsilon bigger than zero + + align:start position:0% +to show for all Epsilon bigger than zero + + + align:start position:0% +to show for all Epsilon bigger than zero +there existant n in the natural + + align:start position:0% +there existant n in the natural + + + align:start position:0% +there existant n in the natural +numbers such + + align:start position:0% +numbers such + + + align:start position:0% +numbers such +that for all n k now bigger than or + + align:start position:0% +that for all n k now bigger than or + + + align:start position:0% +that for all n k now bigger than or +equal to n the distance from X and + + align:start position:0% +equal to n the distance from X and + + + align:start position:0% +equal to n the distance from X and +K to X is less than an + + align:start position:0% +K to X is less than an + + + align:start position:0% +K to X is less than an +Epsilon and now again any guess this as + + align:start position:0% +Epsilon and now again any guess this as + + + align:start position:0% +Epsilon and now again any guess this as +to what we should + + align:start position:0% +to what we should + + + align:start position:0% +to what we should +do triangle inequality precisely yeah so + + align:start position:0% +do triangle inequality precisely yeah so + + + align:start position:0% +do triangle inequality precisely yeah so +we're considering the distance from X + + align:start position:0% +we're considering the distance from X + + + align:start position:0% +we're considering the distance from X +and K to + + align:start position:0% +and K to + + + align:start position:0% +and K to +x what we can do is apply the fact that + + align:start position:0% +x what we can do is apply the fact that + + + align:start position:0% +x what we can do is apply the fact that +we know that convergent sequences are + + align:start position:0% +we know that convergent sequences are + + + align:start position:0% +we know that convergent sequences are +koshy so we can State we can write this + + align:start position:0% +koshy so we can State we can write this + + + align:start position:0% +koshy so we can State we can write this +as less than or equal to the distance + + align:start position:0% +as less than or equal to the distance + + + align:start position:0% +as less than or equal to the distance +from xn K let's say to + + align:start position:0% +from xn K let's say to + + + align:start position:0% +from xn K let's say to +XM for m + + align:start position:0% +XM for m + + + align:start position:0% +XM for m +bigger than or equal to + + align:start position:0% +bigger than or equal to + + + align:start position:0% +bigger than or equal to +n plus the distance from XM to + + align:start position:0% +n plus the distance from XM to + + + align:start position:0% +n plus the distance from XM to +X and now I can choose a larger natural + + align:start position:0% +X and now I can choose a larger natural + + + align:start position:0% +X and now I can choose a larger natural +number if necessary such that this term + + align:start position:0% +number if necessary such that this term + + + align:start position:0% +number if necessary such that this term +gets less than Epsilon / 2 and this term + + align:start position:0% +gets less than Epsilon / 2 and this term + + + align:start position:0% +gets less than Epsilon / 2 and this term +because it's Koshi is less than Epsilon + + align:start position:0% +because it's Koshi is less than Epsilon + + + align:start position:0% +because it's Koshi is less than Epsilon +over 2 so without writing out all those + + align:start position:0% +over 2 so without writing out all those + + + align:start position:0% +over 2 so without writing out all those +steps this is less than + + align:start position:0% + + + + align:start position:0% + +Epsilon so this shows that the distance + + align:start position:0% +Epsilon so this shows that the distance + + + align:start position:0% +Epsilon so this shows that the distance +from X and K to X gets arbitrarily small + + align:start position:0% +from X and K to X gets arbitrarily small + + + align:start position:0% +from X and K to X gets arbitrarily small +so therefore it's convergent + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +yeah this is fairly + + align:start position:0% +yeah this is fairly + + + align:start position:0% +yeah this is fairly +important and it highlights you know one + + align:start position:0% +important and it highlights you know one + + + align:start position:0% +important and it highlights you know one +of the many ways in which Koshi + + align:start position:0% +of the many ways in which Koshi + + + align:start position:0% +of the many ways in which Koshi +sequences are deeply important as we'll + + align:start position:0% +sequences are deeply important as we'll + + + align:start position:0% +sequences are deeply important as we'll +talk about in like the fifth lecture in + + align:start position:0% +talk about in like the fifth lecture in + + + align:start position:0% +talk about in like the fifth lecture in +a specific module of this class uh + + align:start position:0% +a specific module of this class uh + + + align:start position:0% +a specific module of this class uh +having things to be Koshi complete + + align:start position:0% +having things to be Koshi complete + + + align:start position:0% +having things to be Koshi complete +really really helpful + + align:start position:0% + + + + align:start position:0% + +um okay oh one more note this is + + align:start position:0% +um okay oh one more note this is + + + align:start position:0% +um okay oh one more note this is +something that I vaguely noted on uh + + align:start position:0% +something that I vaguely noted on uh + + + align:start position:0% +something that I vaguely noted on uh +Tuesday but these are all of the major + + align:start position:0% +Tuesday but these are all of the major + + + align:start position:0% +Tuesday but these are all of the major +theorems and propositions that we're + + align:start position:0% +theorems and propositions that we're + + + align:start position:0% +theorems and propositions that we're +going to need for convergent sequences + + align:start position:0% +going to need for convergent sequences + + + align:start position:0% +going to need for convergent sequences +you might be wondering why there aren't + + align:start position:0% +you might be wondering why there aren't + + + align:start position:0% +you might be wondering why there aren't +more we had a ton more in real analysis + + align:start position:0% +more we had a ton more in real analysis + + + align:start position:0% +more we had a ton more in real analysis +in fact it took like a month of our time + + align:start position:0% +in fact it took like a month of our time + + + align:start position:0% +in fact it took like a month of our time +the reason we don't have more is because + + align:start position:0% +the reason we don't have more is because + + + align:start position:0% +the reason we don't have more is because +the real numbers are a vector space I + + align:start position:0% +the real numbers are a vector space I + + + align:start position:0% +the real numbers are a vector space I +can add two real numbers and get a real + + align:start position:0% +can add two real numbers and get a real + + + align:start position:0% +can add two real numbers and get a real +number I can multiply them and get a + + align:start position:0% +number I can multiply them and get a + + + align:start position:0% +number I can multiply them and get a +real number everything there was nicer + + align:start position:0% +real number everything there was nicer + + + align:start position:0% +real number everything there was nicer +and we had addition toin so when it + + align:start position:0% +and we had addition toin so when it + + + align:start position:0% +and we had addition toin so when it +meant so one thing we could state in + + align:start position:0% +meant so one thing we could state in + + + align:start position:0% +meant so one thing we could state in +real analysis is that this for instance + + align:start position:0% +real analysis is that this for instance + + + align:start position:0% +real analysis is that this for instance +the sum of two convergent sequences is + + align:start position:0% +the sum of two convergent sequences is + + + align:start position:0% +the sum of two convergent sequences is +convergent here that doesn't make sense + + align:start position:0% +convergent here that doesn't make sense + + + align:start position:0% +convergent here that doesn't make sense +necessarily you can't always add two + + align:start position:0% +necessarily you can't always add two + + + align:start position:0% +necessarily you can't always add two +points in a metric space and get a point + + align:start position:0% +points in a metric space and get a point + + + align:start position:0% +points in a metric space and get a point +in your metric space let alone have + + align:start position:0% +in your metric space let alone have + + + align:start position:0% +in your metric space let alone have +addition be well + + align:start position:0% +addition be well + + + align:start position:0% +addition be well +defined uh similarly we have the squeeze + + align:start position:0% +defined uh similarly we have the squeeze + + + align:start position:0% +defined uh similarly we have the squeeze +theorem in real analysis we have a + + align:start position:0% +theorem in real analysis we have a + + + align:start position:0% +theorem in real analysis we have a +version of it based off of distances but + + align:start position:0% +version of it based off of distances but + + + align:start position:0% +version of it based off of distances but +we don't have a squeeze theorem for + + align:start position:0% +we don't have a squeeze theorem for + + + align:start position:0% +we don't have a squeeze theorem for +points so because we don't necessarily + + align:start position:0% +points so because we don't necessarily + + + align:start position:0% +points so because we don't necessarily +have an ordering on our set right you + + align:start position:0% +have an ordering on our set right you + + + align:start position:0% +have an ordering on our set right you +can picture the complex numbers the + + align:start position:0% +can picture the complex numbers the + + + align:start position:0% +can picture the complex numbers the +complex numbers don't have a uh ordering + + align:start position:0% +complex numbers don't have a uh ordering + + + align:start position:0% +complex numbers don't have a uh ordering +on them you don't have a sense in which + + align:start position:0% +on them you don't have a sense in which + + + align:start position:0% +on them you don't have a sense in which +one complex number is bigger than the + + align:start position:0% +one complex number is bigger than the + + + align:start position:0% +one complex number is bigger than the +other other than yeah I'm just going to + + align:start position:0% +other other than yeah I'm just going to + + + align:start position:0% +other other than yeah I'm just going to +leave it there if you've done complex + + align:start position:0% +leave it there if you've done complex + + + align:start position:0% +leave it there if you've done complex +analysis then you'll know what I'm + + align:start position:0% +analysis then you'll know what I'm + + + align:start position:0% +analysis then you'll know what I'm +talking + + align:start position:0% +talking + + + align:start position:0% +talking +about uh but yeah so that's why we don't + + align:start position:0% +about uh but yeah so that's why we don't + + + align:start position:0% +about uh but yeah so that's why we don't +have more theorems as we used to so now + + align:start position:0% +have more theorems as we used to so now + + + align:start position:0% +have more theorems as we used to so now +we're going to move on to the next major + + align:start position:0% +we're going to move on to the next major + + + align:start position:0% +we're going to move on to the next major +theorem that I've talked about or the + + align:start position:0% +theorem that I've talked about or the + + + align:start position:0% +theorem that I've talked about or the +next major definition that I've talked + + align:start position:0% +next major definition that I've talked + + + align:start position:0% +next major definition that I've talked +about we've talked about convergent + + align:start position:0% +about we've talked about convergent + + + align:start position:0% +about we've talked about convergent +sequences we've talked a little bit + + align:start position:0% +sequences we've talked a little bit + + + align:start position:0% +sequences we've talked a little bit +about koshy sequences kosy sequences are + + align:start position:0% +about koshy sequences kosy sequences are + + + align:start position:0% +about koshy sequences kosy sequences are +helpful but in terms of a metric space + + align:start position:0% +helpful but in terms of a metric space + + + align:start position:0% +helpful but in terms of a metric space +we've mostly St stated what we need for + + align:start position:0% +we've mostly St stated what we need for + + + align:start position:0% +we've mostly St stated what we need for +the moment being + + align:start position:0% +the moment being + + + align:start position:0% +the moment being +uh now we're going to move on to open + + align:start position:0% +uh now we're going to move on to open + + + align:start position:0% +uh now we're going to move on to open +sets so I'm going to recall what this + + align:start position:0% +sets so I'm going to recall what this + + + align:start position:0% +sets so I'm going to recall what this +definition is because it's the one that + + align:start position:0% +definition is because it's the one that + + + align:start position:0% +definition is because it's the one that +can be a little bit the weirdest so + + align:start position:0% + + + + align:start position:0% + +recall a + + align:start position:0% +recall a + + + align:start position:0% +recall a +set a contained in your metric Space + + align:start position:0% +set a contained in your metric Space + + + align:start position:0% +set a contained in your metric Space +X is + + align:start position:0% + + + + align:start position:0% + +open if for all for every single point + + align:start position:0% +open if for all for every single point + + + align:start position:0% +open if for all for every single point +in + + align:start position:0% +in + + + align:start position:0% +in +a there exists an Epsilon bigger than + + align:start position:0% +a there exists an Epsilon bigger than + + + align:start position:0% +a there exists an Epsilon bigger than +zero such that the ball of radius + + align:start position:0% +zero such that the ball of radius + + + align:start position:0% +zero such that the ball of radius +Epsilon around a + + align:start position:0% +Epsilon around a + + + align:start position:0% +Epsilon around a +is completely contained in your set and + + align:start position:0% +is completely contained in your set and + + + align:start position:0% +is completely contained in your set and +this is the set of Y in your metric + + align:start position:0% +this is the set of Y in your metric + + + align:start position:0% +this is the set of Y in your metric +space such that the distance from y to a + + align:start position:0% +space such that the distance from y to a + + + align:start position:0% +space such that the distance from y to a +is less than + + align:start position:0% +is less than + + + align:start position:0% +is less than +Epsilon uh just to bring it up because + + align:start position:0% +Epsilon uh just to bring it up because + + + align:start position:0% +Epsilon uh just to bring it up because +sometimes the notation comes up this is + + align:start position:0% +sometimes the notation comes up this is + + + align:start position:0% +sometimes the notation comes up this is +also sometimes + + align:start position:0% +also sometimes + + + align:start position:0% +also sometimes +denoted the ball around a of radius + + align:start position:0% +denoted the ball around a of radius + + + align:start position:0% +denoted the ball around a of radius +Epsilon so use whichever notation you + + align:start position:0% +Epsilon so use whichever notation you + + + align:start position:0% +Epsilon so use whichever notation you +prefer uh can you here I can move it a + + align:start position:0% +prefer uh can you here I can move it a + + + align:start position:0% +prefer uh can you here I can move it a +little bit up so use whichever notation + + align:start position:0% +little bit up so use whichever notation + + + align:start position:0% +little bit up so use whichever notation +you prefer + + align:start position:0% +you prefer + + + align:start position:0% +you prefer +uh I prefer this one just because it + + align:start position:0% +uh I prefer this one just because it + + + align:start position:0% +uh I prefer this one just because it +means uh less commas but you know + + align:start position:0% +means uh less commas but you know + + + align:start position:0% +means uh less commas but you know +whichever + + align:start position:0% +whichever + + + align:start position:0% +whichever +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh open sets are going to have a huge + + align:start position:0% +so uh open sets are going to have a huge + + + align:start position:0% +so uh open sets are going to have a huge +connection between topology and + + align:start position:0% +connection between topology and + + + align:start position:0% +connection between topology and +continuity and other definitions that + + align:start position:0% +continuity and other definitions that + + + align:start position:0% +continuity and other definitions that +are important now the first thing that + + align:start position:0% +are important now the first thing that + + + align:start position:0% +are important now the first thing that +we're going to prove is topological + + align:start position:0% +we're going to prove is topological + + + align:start position:0% +we're going to prove is topological +properties of open sets so because + + align:start position:0% +properties of open sets so because + + + align:start position:0% +properties of open sets so because +youall haven't taken topology this is in + + align:start position:0% +youall haven't taken topology this is in + + + align:start position:0% +youall haven't taken topology this is in +fact really really helpful we're going + + align:start position:0% +fact really really helpful we're going + + + align:start position:0% +fact really really helpful we're going +to show three major properties of uh + + align:start position:0% +to show three major properties of uh + + + align:start position:0% +to show three major properties of uh +open sets in metric spaces so a + + align:start position:0% + + + + align:start position:0% + +theorem uh and you can call this + + align:start position:0% +theorem uh and you can call this + + + align:start position:0% +theorem uh and you can call this +topological properties if you + + align:start position:0% +topological properties if you + + + align:start position:0% +topological properties if you +want or I'll write it out cu + + align:start position:0% + + + + align:start position:0% + +topological + + align:start position:0% + + + + align:start position:0% + +properties of open + + align:start position:0% + + + + align:start position:0% + +sets Okay firstly we have that the empty + + align:start position:0% +sets Okay firstly we have that the empty + + + align:start position:0% +sets Okay firstly we have that the empty +set and the entire metric bace + + align:start position:0% +set and the entire metric bace + + + align:start position:0% +set and the entire metric bace +itself are + + align:start position:0% + + + + align:start position:0% + +open + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +given + + align:start position:0% +given + + + align:start position:0% +given +AI are open + + align:start position:0% + + + + align:start position:0% + +sets then the union of all of these sets + + align:start position:0% +sets then the union of all of these sets + + + align:start position:0% +sets then the union of all of these sets +from I equals let's say one to infinity + + align:start position:0% +from I equals let's say one to infinity + + + align:start position:0% +from I equals let's say one to infinity +or all see Zero why not uh is open so in + + align:start position:0% +or all see Zero why not uh is open so in + + + align:start position:0% +or all see Zero why not uh is open so in +other words the arbitrary Union of open + + align:start position:0% +other words the arbitrary Union of open + + + align:start position:0% +other words the arbitrary Union of open +sets is + + align:start position:0% +sets is + + + align:start position:0% +sets is +open and + + align:start position:0% + + + + align:start position:0% + +finally uh the finite + + align:start position:0% + + + + align:start position:0% + +intersections of open sets are + + align:start position:0% + + + + align:start position:0% + +open in other words if I intersect from + + align:start position:0% +open in other words if I intersect from + + + align:start position:0% +open in other words if I intersect from +IAL 0 to capital M of a I then this is + + align:start position:0% +IAL 0 to capital M of a I then this is + + + align:start position:0% +IAL 0 to capital M of a I then this is +open the fact that we can't intersect + + align:start position:0% +open the fact that we can't intersect + + + align:start position:0% +open the fact that we can't intersect +infinitely many of them will become + + align:start position:0% +infinitely many of them will become + + + align:start position:0% +infinitely many of them will become +apparent in the proof so in the proof of + + align:start position:0% +apparent in the proof so in the proof of + + + align:start position:0% +apparent in the proof so in the proof of +these three properties it'll become + + align:start position:0% +these three properties it'll become + + + align:start position:0% +these three properties it'll become +apparent why we can't do infinitely many + + align:start position:0% +apparent why we can't do infinitely many + + + align:start position:0% +apparent why we can't do infinitely many +of them but let's see + + align:start position:0% + + + + align:start position:0% + +this one so consider the empty set how + + align:start position:0% +this one so consider the empty set how + + + align:start position:0% +this one so consider the empty set how +do we know that the empty set is open + + align:start position:0% +do we know that the empty set is open + + + align:start position:0% +do we know that the empty set is open +well it's vasly true it's true all the + + align:start position:0% +well it's vasly true it's true all the + + + align:start position:0% +well it's vasly true it's true all the +time because for every single point in + + align:start position:0% +time because for every single point in + + + align:start position:0% +time because for every single point in +the empty set there are no points in the + + align:start position:0% +the empty set there are no points in the + + + align:start position:0% +the empty set there are no points in the +empty set so as soon as that statement + + align:start position:0% +empty set so as soon as that statement + + + align:start position:0% +empty set so as soon as that statement +is false we have that the empty set is + + align:start position:0% +is false we have that the empty set is + + + align:start position:0% +is false we have that the empty set is +open so this is open vake is + + align:start position:0% + + + + align:start position:0% + +sleeve two let's consider the set X well + + align:start position:0% +sleeve two let's consider the set X well + + + align:start position:0% +sleeve two let's consider the set X well +for + + align:start position:0% +for + + + align:start position:0% +for +all Epsilon or sorry for every single + + align:start position:0% +all Epsilon or sorry for every single + + + align:start position:0% +all Epsilon or sorry for every single +point x and + + align:start position:0% +point x and + + + align:start position:0% +point x and +x does there exist a ball around x and x + + align:start position:0% +x does there exist a ball around x and x + + + align:start position:0% +x does there exist a ball around x and x +yes there is because just pick + + align:start position:0% +yes there is because just pick + + + align:start position:0% +yes there is because just pick +pick your favorite Epsilon bigger than + + align:start position:0% +pick your favorite Epsilon bigger than + + + align:start position:0% +pick your favorite Epsilon bigger than +zero and then the ball of radius Epsilon + + align:start position:0% +zero and then the ball of radius Epsilon + + + align:start position:0% +zero and then the ball of radius Epsilon +around that point x is by definition a + + align:start position:0% +around that point x is by definition a + + + align:start position:0% +around that point x is by definition a +subset of your metric space right + + align:start position:0% +subset of your metric space right + + + align:start position:0% +subset of your metric space right +because the definition of a ball of + + align:start position:0% +because the definition of a ball of + + + align:start position:0% +because the definition of a ball of +radius Epsilon is only the point in X so + + align:start position:0% +radius Epsilon is only the point in X so + + + align:start position:0% +radius Epsilon is only the point in X so +we're not going to end up with some + + align:start position:0% +we're not going to end up with some + + + align:start position:0% +we're not going to end up with some +weird thing outside of + + align:start position:0% +weird thing outside of + + + align:start position:0% +weird thing outside of +X so this shows that X itself is + + align:start position:0% +X so this shows that X itself is + + + align:start position:0% +X so this shows that X itself is +open two we want to show that the union + + align:start position:0% +open two we want to show that the union + + + align:start position:0% +open two we want to show that the union +of open sets is open how' we do + + align:start position:0% + + + + align:start position:0% + +that um IAL 0 to Infinity is + + align:start position:0% +that um IAL 0 to Infinity is + + + align:start position:0% +that um IAL 0 to Infinity is +open this is what we want to + + align:start position:0% +open this is what we want to + + + align:start position:0% +open this is what we want to +show well as as with the definition + + align:start position:0% +show well as as with the definition + + + align:start position:0% +show well as as with the definition +we're just going to pick a point in the + + align:start position:0% +we're just going to pick a point in the + + + align:start position:0% +we're just going to pick a point in the +union so pick arbitrary X in the union I + + align:start position:0% +union so pick arbitrary X in the union I + + + align:start position:0% +union so pick arbitrary X in the union I +equal 0 to Infinity of a + + align:start position:0% +equal 0 to Infinity of a + + + align:start position:0% +equal 0 to Infinity of a +i and we want to show that there exists + + align:start position:0% +i and we want to show that there exists + + + align:start position:0% +i and we want to show that there exists +a ball of radius Epsilon around X that's + + align:start position:0% +a ball of radius Epsilon around X that's + + + align:start position:0% +a ball of radius Epsilon around X that's +contained in the set well because it's + + align:start position:0% +contained in the set well because it's + + + align:start position:0% +contained in the set well because it's +in the union there has to exist at least + + align:start position:0% +in the union there has to exist at least + + + align:start position:0% +in the union there has to exist at least +one AI that contains X so therefore + + align:start position:0% +one AI that contains X so therefore + + + align:start position:0% +one AI that contains X so therefore +there exists an AJ in your set of open + + align:start position:0% +there exists an AJ in your set of open + + + align:start position:0% +there exists an AJ in your set of open +sets + + align:start position:0% +sets + + + align:start position:0% +sets +AI such that X is in + + align:start position:0% +AI such that X is in + + + align:start position:0% +AI such that X is in +AJ and then we apply the fact that AJ + + align:start position:0% +AJ and then we apply the fact that AJ + + + align:start position:0% +AJ and then we apply the fact that AJ +itself is open so therefore there exists + + align:start position:0% +itself is open so therefore there exists + + + align:start position:0% +itself is open so therefore there exists +an Epsilon bigger than zero such that + + align:start position:0% +an Epsilon bigger than zero such that + + + align:start position:0% +an Epsilon bigger than zero such that +the ball of radius Epsilon around X is + + align:start position:0% +the ball of radius Epsilon around X is + + + align:start position:0% +the ball of radius Epsilon around X is +contained in + + align:start position:0% +contained in + + + align:start position:0% +contained in +AI or sorry AJ + + align:start position:0% +AI or sorry AJ + + + align:start position:0% +AI or sorry AJ +but this is a subset of the + + align:start position:0% + + + + align:start position:0% + +Union so this shows that the ball of + + align:start position:0% +Union so this shows that the ball of + + + align:start position:0% +Union so this shows that the ball of +radius Epsilon is contained in the + + align:start position:0% +radius Epsilon is contained in the + + + align:start position:0% +radius Epsilon is contained in the +infinite Union or potentially infinite + + align:start position:0% +infinite Union or potentially infinite + + + align:start position:0% +infinite Union or potentially infinite +Union this also works if it's finite + + align:start position:0% +Union this also works if it's finite + + + align:start position:0% +Union this also works if it's finite +notice but you know that that's just a + + align:start position:0% +notice but you know that that's just a + + + align:start position:0% +notice but you know that that's just a +subcase okay uh and can I squeeze it in + + align:start position:0% +subcase okay uh and can I squeeze it in + + + align:start position:0% +subcase okay uh and can I squeeze it in +here no I cannot so I will move over + + align:start position:0% +here no I cannot so I will move over + + + align:start position:0% +here no I cannot so I will move over +here any questions so far actually let + + align:start position:0% +here any questions so far actually let + + + align:start position:0% +here any questions so far actually let +me move with this any questions + + align:start position:0% +me move with this any questions + + + align:start position:0% +me move with this any questions +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +open sets are weird in + + align:start position:0% +open sets are weird in + + + align:start position:0% +open sets are weird in +that you know when we learn about them + + align:start position:0% +that you know when we learn about them + + + align:start position:0% +that you know when we learn about them +in real analysis I feel like they're + + align:start position:0% +in real analysis I feel like they're + + + align:start position:0% +in real analysis I feel like they're +pretty unintuitively important everyone + + align:start position:0% +pretty unintuitively important everyone + + + align:start position:0% +pretty unintuitively important everyone +says that they're + + align:start position:0% +says that they're + + + align:start position:0% +says that they're +important but I never got why and I'll + + align:start position:0% +important but I never got why and I'll + + + align:start position:0% +important but I never got why and I'll +explain why they are just like in a + + align:start position:0% +explain why they are just like in a + + + align:start position:0% +explain why they are just like in a +moment um but yeah open sets are deeply + + align:start position:0% +moment um but yeah open sets are deeply + + + align:start position:0% +moment um but yeah open sets are deeply +important in real analysis Sy + + align:start position:0% +important in real analysis Sy + + + align:start position:0% +important in real analysis Sy +topology and we're going to prove some + + align:start position:0% +topology and we're going to prove some + + + align:start position:0% +topology and we're going to prove some +more statements besides these + + align:start position:0% +more statements besides these + + + align:start position:0% +more statements besides these +topological + + align:start position:0% +topological + + + align:start position:0% +topological +properties that will be + + align:start position:0% +properties that will be + + + align:start position:0% +properties that will be +important uh and we'll relate to the + + align:start position:0% +important uh and we'll relate to the + + + align:start position:0% +important uh and we'll relate to the +major definitions in our tool tool + + align:start position:0% + + + + align:start position:0% + +box + + align:start position:0% +box + + + align:start position:0% +box +okay so now we're interested + + align:start position:0% +okay so now we're interested + + + align:start position:0% +okay so now we're interested +in the third case the intersection from + + align:start position:0% +in the third case the intersection from + + + align:start position:0% +in the third case the intersection from +I equals 0 to M of the AI well we're + + align:start position:0% +I equals 0 to M of the AI well we're + + + align:start position:0% +I equals 0 to M of the AI well we're +going to do exactly as we did + + align:start position:0% +going to do exactly as we did + + + align:start position:0% +going to do exactly as we did +before if I have some X the intersection + + align:start position:0% +before if I have some X the intersection + + + align:start position:0% +before if I have some X the intersection +of the AI from i = 0 to M then what do I + + align:start position:0% +of the AI from i = 0 to M then what do I + + + align:start position:0% +of the AI from i = 0 to M then what do I +know before we knew that it was in any + + align:start position:0% +know before we knew that it was in any + + + align:start position:0% +know before we knew that it was in any +of the AIS but here we know even more + + align:start position:0% +of the AIS but here we know even more + + + align:start position:0% +of the AIS but here we know even more +information here we know that X is in AI + + align:start position:0% +information here we know that X is in AI + + + align:start position:0% +information here we know that X is in AI +for every single + + align:start position:0% +for every single + + + align:start position:0% +for every single +I so what can we do well we know that + + align:start position:0% +I so what can we do well we know that + + + align:start position:0% +I so what can we do well we know that +therefore because each AI is open there + + align:start position:0% +therefore because each AI is open there + + + align:start position:0% +therefore because each AI is open there +exists an Epsilon I bigger than zero + + align:start position:0% +exists an Epsilon I bigger than zero + + + align:start position:0% +exists an Epsilon I bigger than zero +such that the ball of radius Epsilon I + + align:start position:0% +such that the ball of radius Epsilon I + + + align:start position:0% +such that the ball of radius Epsilon I +around X is contained in + + align:start position:0% +around X is contained in + + + align:start position:0% +around X is contained in +AI the issue is that the entirety of AI + + align:start position:0% +AI the issue is that the entirety of AI + + + align:start position:0% +AI the issue is that the entirety of AI +might not be in the intersection so what + + align:start position:0% +might not be in the intersection so what + + + align:start position:0% +might not be in the intersection so what +can we do we have this for every single + + align:start position:0% +can we do we have this for every single + + + align:start position:0% +can we do we have this for every single +I and we have finitely many of them so + + align:start position:0% + + + + align:start position:0% + +choose uh Epsilon to be equal to the + + align:start position:0% +choose uh Epsilon to be equal to the + + + align:start position:0% +choose uh Epsilon to be equal to the +minimum of the Epsilon I from I equals z + + align:start position:0% +minimum of the Epsilon I from I equals z + + + align:start position:0% +minimum of the Epsilon I from I equals z +or 0 to + + align:start position:0% +or 0 to + + + align:start position:0% +or 0 to +m capital + + align:start position:0% +m capital + + + align:start position:0% +m capital +M this is bigger than zero right because + + align:start position:0% +M this is bigger than zero right because + + + align:start position:0% +M this is bigger than zero right because +we're only choosing finitely many this + + align:start position:0% +we're only choosing finitely many this + + + align:start position:0% +we're only choosing finitely many this +is where we're using the fact that + + align:start position:0% +is where we're using the fact that + + + align:start position:0% +is where we're using the fact that +there's the finite intersection if we + + align:start position:0% +there's the finite intersection if we + + + align:start position:0% +there's the finite intersection if we +had an infinite intersection you can + + align:start position:0% +had an infinite intersection you can + + + align:start position:0% +had an infinite intersection you can +picture taking um more and more uh + + align:start position:0% +picture taking um more and more uh + + + align:start position:0% +picture taking um more and more uh +smaller and smaller Epsilon I such that + + align:start position:0% +smaller and smaller Epsilon I such that + + + align:start position:0% +smaller and smaller Epsilon I such that +this uh infinum is zero and that's an + + align:start position:0% +this uh infinum is zero and that's an + + + align:start position:0% +this uh infinum is zero and that's an +issue but if it's finitely many we can + + align:start position:0% +issue but if it's finitely many we can + + + align:start position:0% +issue but if it's finitely many we can +take the minimum of them and then what + + align:start position:0% +take the minimum of them and then what + + + align:start position:0% +take the minimum of them and then what +we know is that the ball of radius + + align:start position:0% +we know is that the ball of radius + + + align:start position:0% +we know is that the ball of radius +Epsilon round X is a subset of AI for + + align:start position:0% +Epsilon round X is a subset of AI for + + + align:start position:0% +Epsilon round X is a subset of AI for +all I because it's contained in the ball + + align:start position:0% +all I because it's contained in the ball + + + align:start position:0% +all I because it's contained in the ball +of radius Epsilon + + align:start position:0% +of radius Epsilon + + + align:start position:0% +of radius Epsilon +I I guess I should tell that this is + + align:start position:0% +I I guess I should tell that this is + + + align:start position:0% +I I guess I should tell that this is +contained in the ball of radius Epsilon + + align:start position:0% +contained in the ball of radius Epsilon + + + align:start position:0% +contained in the ball of radius Epsilon +I of + + align:start position:0% +I of + + + align:start position:0% +I of +X which is contained in AI for all I + + align:start position:0% +X which is contained in AI for all I + + + align:start position:0% +X which is contained in AI for all I +which implies that the ball of radius + + align:start position:0% +which implies that the ball of radius + + + align:start position:0% +which implies that the ball of radius +Epsilon around X is a subset of the + + align:start position:0% +Epsilon around X is a subset of the + + + align:start position:0% +Epsilon around X is a subset of the +finite + + align:start position:0% + + + + align:start position:0% + +intersection all right all right so why + + align:start position:0% +intersection all right all right so why + + + align:start position:0% +intersection all right all right so why +is this called the topological + + align:start position:0% +is this called the topological + + + align:start position:0% +is this called the topological +properties of open sets because if you + + align:start position:0% +properties of open sets because if you + + + align:start position:0% +properties of open sets because if you +were to take 18901 which is a class that + + align:start position:0% +were to take 18901 which is a class that + + + align:start position:0% +were to take 18901 which is a class that +I would highly suggest to take at some + + align:start position:0% +I would highly suggest to take at some + + + align:start position:0% +I would highly suggest to take at some +point if you're interested in this sort + + align:start position:0% +point if you're interested in this sort + + + align:start position:0% +point if you're interested in this sort +of + + align:start position:0% +of + + + align:start position:0% +of +analysis uh as we're going to see open + + align:start position:0% +analysis uh as we're going to see open + + + align:start position:0% +analysis uh as we're going to see open +sets allow us to state things about + + align:start position:0% +sets allow us to state things about + + + align:start position:0% +sets allow us to state things about +continuity you can Define continuity in + + align:start position:0% +continuity you can Define continuity in + + + align:start position:0% +continuity you can Define continuity in +terms of open sets you can Define + + align:start position:0% +terms of open sets you can Define + + + align:start position:0% +terms of open sets you can Define +convergent sequences in terms of open + + align:start position:0% +convergent sequences in terms of open + + + align:start position:0% +convergent sequences in terms of open +sets basically everything we can redo in + + align:start position:0% +sets basically everything we can redo in + + + align:start position:0% +sets basically everything we can redo in +terms of open sets and that is a + + align:start position:0% +terms of open sets and that is a + + + align:start position:0% +terms of open sets and that is a +topology if I have a set of subsets such + + align:start position:0% +topology if I have a set of subsets such + + + align:start position:0% +topology if I have a set of subsets such +that these three properties hold that's + + align:start position:0% +that these three properties hold that's + + + align:start position:0% +that these three properties hold that's +known as a topology and in 18901 that's + + align:start position:0% +known as a topology and in 18901 that's + + + align:start position:0% +known as a topology and in 18901 that's +the basic toolbox that you're given and + + align:start position:0% +the basic toolbox that you're given and + + + align:start position:0% +the basic toolbox that you're given and +then you go from there in terms of + + align:start position:0% +then you go from there in terms of + + + align:start position:0% +then you go from there in terms of +redefining everything so this is just an + + align:start position:0% +redefining everything so this is just an + + + align:start position:0% +redefining everything so this is just an +example of uh a more General thing than + + align:start position:0% +example of uh a more General thing than + + + align:start position:0% +example of uh a more General thing than +metric + + align:start position:0% +metric + + + align:start position:0% +metric +spaces um I'm going to talk a little bit + + align:start position:0% +spaces um I'm going to talk a little bit + + + align:start position:0% +spaces um I'm going to talk a little bit +about that in the final lecture where I + + align:start position:0% +about that in the final lecture where I + + + align:start position:0% +about that in the final lecture where I +talk about you know where things go from + + align:start position:0% +talk about you know where things go from + + + align:start position:0% +talk about you know where things go from +here but for now this is you know the + + align:start position:0% +here but for now this is you know the + + + align:start position:0% +here but for now this is you know the +basic + + align:start position:0% +basic + + + align:start position:0% +basic +idea all right uh + + align:start position:0% +idea all right uh + + + align:start position:0% +idea all right uh +uh now what I'm going to state is some + + align:start position:0% +uh now what I'm going to state is some + + + align:start position:0% +uh now what I'm going to state is some +facts about closed sets but what is a + + align:start position:0% +facts about closed sets but what is a + + + align:start position:0% +facts about closed sets but what is a +closed + + align:start position:0% +closed + + + align:start position:0% +closed +set which I haven't defined before so + + align:start position:0% +set which I haven't defined before so + + + align:start position:0% +set which I haven't defined before so +this is useful to note a subset a in + + align:start position:0% +this is useful to note a subset a in + + + align:start position:0% +this is useful to note a subset a in +X is + + align:start position:0% + + + + align:start position:0% + +closed if + + align:start position:0% +closed if + + + align:start position:0% +closed if +a uh if the complement of a which is + + align:start position:0% +a uh if the complement of a which is + + + align:start position:0% +a uh if the complement of a which is +known as this the metric bace x minus + + align:start position:0% +known as this the metric bace x minus + + + align:start position:0% +known as this the metric bace x minus +a is open + + align:start position:0% + + + + align:start position:0% + +now if a set is closed does that imply + + align:start position:0% +now if a set is closed does that imply + + + align:start position:0% +now if a set is closed does that imply +that it's not + + align:start position:0% +that it's not + + + align:start position:0% +that it's not +open yeah the answer is no how can we + + align:start position:0% +open yeah the answer is no how can we + + + align:start position:0% +open yeah the answer is no how can we +see that well let's consider the real + + align:start position:0% +see that well let's consider the real + + + align:start position:0% +see that well let's consider the real +numbers as an + + align:start position:0% + + + + align:start position:0% + +example uh + + align:start position:0% +example uh + + + align:start position:0% +example uh +notice what's the complement of the + + align:start position:0% +notice what's the complement of the + + + align:start position:0% +notice what's the complement of the +empty set in the real + + align:start position:0% + + + + align:start position:0% + +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +anyone it's a good exercise and thinking + + align:start position:0% +anyone it's a good exercise and thinking + + + align:start position:0% +anyone it's a good exercise and thinking +about what the complement + + align:start position:0% +about what the complement + + + align:start position:0% +about what the complement +means real numbers minus the empty set + + align:start position:0% +means real numbers minus the empty set + + + align:start position:0% +means real numbers minus the empty set +so it's just going to be all of the real + + align:start position:0% +so it's just going to be all of the real + + + align:start position:0% +so it's just going to be all of the real +numbers but this as we've stated before + + align:start position:0% +numbers but this as we've stated before + + + align:start position:0% +numbers but this as we've stated before +in our first topological property this + + align:start position:0% +in our first topological property this + + + align:start position:0% +in our first topological property this +is + + align:start position:0% +is + + + align:start position:0% +is +open so therefore the empty + + align:start position:0% +open so therefore the empty + + + align:start position:0% +open so therefore the empty +set is closed by + + align:start position:0% +set is closed by + + + align:start position:0% +set is closed by +definition but we also know by our + + align:start position:0% +definition but we also know by our + + + align:start position:0% +definition but we also know by our +topological properties again that the + + align:start position:0% +topological properties again that the + + + align:start position:0% +topological properties again that the +empty set is + + align:start position:0% + + + + align:start position:0% + +open what the heck well this is just one + + align:start position:0% +open what the heck well this is just one + + + align:start position:0% +open what the heck well this is just one +of those things in topology it's kind of + + align:start position:0% +of those things in topology it's kind of + + + align:start position:0% +of those things in topology it's kind of +weird like open sets you can prove + + align:start position:0% +weird like open sets you can prove + + + align:start position:0% +weird like open sets you can prove +properties of closed sets instead and + + align:start position:0% +properties of closed sets instead and + + + align:start position:0% +properties of closed sets instead and +things are everything everything's fine + + align:start position:0% +things are everything everything's fine + + + align:start position:0% +things are everything everything's fine +um I'll + + align:start position:0% +um I'll + + + align:start position:0% +um I'll +note + + align:start position:0% + + + + align:start position:0% + +note there's a notion called + + align:start position:0% + + + + align:start position:0% + +connectedness which I'll briefly Define + + align:start position:0% +connectedness which I'll briefly Define + + + align:start position:0% +connectedness which I'll briefly Define +But ultimately will be more of a problem + + align:start position:0% +But ultimately will be more of a problem + + + align:start position:0% +But ultimately will be more of a problem +set problem but if your metric space is + + align:start position:0% +set problem but if your metric space is + + + align:start position:0% +set problem but if your metric space is +connected uh let me state it that way + + align:start position:0% + + + + align:start position:0% + +if if your metric Space X is connected + + align:start position:0% +if if your metric Space X is connected + + + align:start position:0% +if if your metric Space X is connected +which I'll redefine in a mo or which + + align:start position:0% +which I'll redefine in a mo or which + + + align:start position:0% +which I'll redefine in a mo or which +I'll Define in a + + align:start position:0% + + + + align:start position:0% + +moment this is true if and only if the + + align:start position:0% + + + + align:start position:0% + +only open and closed + + align:start position:0% +only open and closed + + + align:start position:0% +only open and closed +sets so sets that are both open and + + align:start position:0% +sets so sets that are both open and + + + align:start position:0% +sets so sets that are both open and +closed are the empty + + align:start position:0% +closed are the empty + + + align:start position:0% +closed are the empty +set and the metric space + + align:start position:0% +set and the metric space + + + align:start position:0% +set and the metric space +itself now what does it mean for your + + align:start position:0% +itself now what does it mean for your + + + align:start position:0% +itself now what does it mean for your +metric space to be connected I mean we + + align:start position:0% +metric space to be connected I mean we + + + align:start position:0% +metric space to be connected I mean we +have a nice picture of it in our heads + + align:start position:0% +have a nice picture of it in our heads + + + align:start position:0% +have a nice picture of it in our heads +CU connected is a pretty visual thing + + align:start position:0% +CU connected is a pretty visual thing + + + align:start position:0% +CU connected is a pretty visual thing +but this is one definition once you + + align:start position:0% +but this is one definition once you + + + align:start position:0% +but this is one definition once you +prove this this is a definition how do + + align:start position:0% +prove this this is a definition how do + + + align:start position:0% +prove this this is a definition how do +you prove this well you prove it based + + align:start position:0% +you prove this well you prove it based + + + align:start position:0% +you prove this well you prove it based +off of the definition of disconnected so + + align:start position:0% +off of the definition of disconnected so + + + align:start position:0% +off of the definition of disconnected so +definition X is + + align:start position:0% +definition X is + + + align:start position:0% +definition X is +disconnected by + + align:start position:0% +disconnected by + + + align:start position:0% +disconnected by +definition if there exists two open sets + + align:start position:0% +definition if there exists two open sets + + + align:start position:0% +definition if there exists two open sets +U1 and U2 that are + + align:start position:0% + + + + align:start position:0% + +joint + + align:start position:0% +joint + + + align:start position:0% +joint +disjoint and + + align:start position:0% + + + + align:start position:0% + +non-empty such that uh the union of + + align:start position:0% + + + + align:start position:0% + +them is exactly X this is what it means + + align:start position:0% +them is exactly X this is what it means + + + align:start position:0% +them is exactly X this is what it means +for your space to be + + align:start position:0% +for your space to be + + + align:start position:0% +for your space to be +disconnected and from here a set is + + align:start position:0% +disconnected and from here a set is + + + align:start position:0% +disconnected and from here a set is +connected if it is not disconnected so + + align:start position:0% +connected if it is not disconnected so + + + align:start position:0% +connected if it is not disconnected so +kind of kind kind of circular reasoning + + align:start position:0% +kind of kind kind of circular reasoning + + + align:start position:0% +kind of kind kind of circular reasoning +and then once you have that you can + + align:start position:0% +and then once you have that you can + + + align:start position:0% +and then once you have that you can +prove this note which I'll put in the + + align:start position:0% +prove this note which I'll put in the + + + align:start position:0% +prove this note which I'll put in the +problem or the third problem set which + + align:start position:0% +problem or the third problem set which + + + align:start position:0% +problem or the third problem set which +is an interesting problem + + align:start position:0% +is an interesting problem + + + align:start position:0% +is an interesting problem +um but I just want to knowe showing + + align:start position:0% +um but I just want to knowe showing + + + align:start position:0% +um but I just want to knowe showing +something is closed does not necessarily + + align:start position:0% +something is closed does not necessarily + + + align:start position:0% +something is closed does not necessarily +imply that it's + + align:start position:0% +imply that it's + + + align:start position:0% +imply that it's +open uh I'll give one short example of + + align:start position:0% +open uh I'll give one short example of + + + align:start position:0% +open uh I'll give one short example of +why this is true and then I'll move on + + align:start position:0% +why this is true and then I'll move on + + + align:start position:0% +why this is true and then I'll move on +to more properties of open + + align:start position:0% +to more properties of open + + + align:start position:0% +to more properties of open +sets anyone have + + align:start position:0% +sets anyone have + + + align:start position:0% +sets anyone have +questions + + align:start position:0% +questions + + + align:start position:0% +questions +cool uh feel free to shout out questions + + align:start position:0% +cool uh feel free to shout out questions + + + align:start position:0% +cool uh feel free to shout out questions +if you have any or interrupt I'm more + + align:start position:0% +if you have any or interrupt I'm more + + + align:start position:0% +if you have any or interrupt I'm more +than happy to be + + align:start position:0% + + + + align:start position:0% + +interrupted okay so I'm just going to + + align:start position:0% +interrupted okay so I'm just going to + + + align:start position:0% +interrupted okay so I'm just going to +give one example of a metric space that + + align:start position:0% +give one example of a metric space that + + + align:start position:0% +give one example of a metric space that +is disconnected which is one that makes + + align:start position:0% +is disconnected which is one that makes + + + align:start position:0% +is disconnected which is one that makes +relative sense at least on the face of + + align:start position:0% +relative sense at least on the face of + + + align:start position:0% +relative sense at least on the face of +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +example I can take the a union of two + + align:start position:0% +example I can take the a union of two + + + align:start position:0% +example I can take the a union of two +open intervals 0 to 1 and 1 to two and + + align:start position:0% +open intervals 0 to 1 and 1 to two and + + + align:start position:0% +open intervals 0 to 1 and 1 to two and +give + + align:start position:0% + + + + align:start position:0% + +it the usual + + align:start position:0% + + + + align:start position:0% + +metric on + + align:start position:0% + + + + align:start position:0% + +R what do I mean by usual metric I mean + + align:start position:0% +R what do I mean by usual metric I mean + + + align:start position:0% +R what do I mean by usual metric I mean +the distance between two points in this + + align:start position:0% +the distance between two points in this + + + align:start position:0% +the distance between two points in this +set is just the distance normally in R + + align:start position:0% +set is just the distance normally in R + + + align:start position:0% +set is just the distance normally in R +right absolute + + align:start position:0% +right absolute + + + align:start position:0% +right absolute +values this is an example of one that's + + align:start position:0% +values this is an example of one that's + + + align:start position:0% +values this is an example of one that's +disconnected right because it's the + + align:start position:0% +disconnected right because it's the + + + align:start position:0% +disconnected right because it's the +union of two or one that is is + + align:start position:0% +union of two or one that is is + + + align:start position:0% +union of two or one that is is +disconnected it is the union of two open + + align:start position:0% +disconnected it is the union of two open + + + align:start position:0% +disconnected it is the union of two open +sets right that are + + align:start position:0% +sets right that are + + + align:start position:0% +sets right that are +disjointed and you can notice here the + + align:start position:0% +disjointed and you can notice here the + + + align:start position:0% +disjointed and you can notice here the +interval 01 is both open and + + align:start position:0% +interval 01 is both open and + + + align:start position:0% +interval 01 is both open and +closed + + align:start position:0% +closed + + + align:start position:0% +closed +so uh because the complement of it is + + align:start position:0% +so uh because the complement of it is + + + align:start position:0% +so uh because the complement of it is +just one two and that's open so this is + + align:start position:0% +just one two and that's open so this is + + + align:start position:0% +just one two and that's open so this is +an interesting example to think through + + align:start position:0% +an interesting example to think through + + + align:start position:0% +an interesting example to think through +this is known as the Subspace metric + + align:start position:0% +this is known as the Subspace metric + + + align:start position:0% +this is known as the Subspace metric +it's really or the Subspace topology + + align:start position:0% +it's really or the Subspace topology + + + align:start position:0% +it's really or the Subspace topology +technically um but yeah okay let's go + + align:start position:0% +technically um but yeah okay let's go + + + align:start position:0% +technically um but yeah okay let's go +back to proving things about the general + + align:start position:0% +back to proving things about the general + + + align:start position:0% +back to proving things about the general +theory of open + + align:start position:0% +theory of open + + + align:start position:0% +theory of open +sets proposition I'm first going to + + align:start position:0% +sets proposition I'm first going to + + + align:start position:0% +sets proposition I'm first going to +point out that closed sets are very + + align:start position:0% +point out that closed sets are very + + + align:start position:0% +point out that closed sets are very +similar to top uh very similar to open + + align:start position:0% +similar to top uh very similar to open + + + align:start position:0% +similar to top uh very similar to open +sets in fact we can Define everything in + + align:start position:0% +sets in fact we can Define everything in + + + align:start position:0% +sets in fact we can Define everything in +terms of of closed sets if you wanted to + + align:start position:0% +terms of of closed sets if you wanted to + + + align:start position:0% +terms of of closed sets if you wanted to +properties of closed + + align:start position:0% + + + + align:start position:0% + +sets here we have that the empty set and + + align:start position:0% +sets here we have that the empty set and + + + align:start position:0% +sets here we have that the empty set and +X are + + align:start position:0% + + + + align:start position:0% + +closed to + + align:start position:0% +closed to + + + align:start position:0% +closed to +the infinite the potentially infinite + + align:start position:0% +the infinite the potentially infinite + + + align:start position:0% +the infinite the potentially infinite +intersection of closed + + align:start position:0% +intersection of closed + + + align:start position:0% +intersection of closed +sets AI + + align:start position:0% + + + + align:start position:0% + +closed is + + align:start position:0% + + + + align:start position:0% + +closed and + + align:start position:0% +closed and + + + align:start position:0% +closed and +three the finite + + align:start position:0% + + + + align:start position:0% + +Union of Clos + + align:start position:0% + + + + align:start position:0% + +sets is closed + + align:start position:0% + + + + align:start position:0% + +nearly identical to the topological + + align:start position:0% +nearly identical to the topological + + + align:start position:0% +nearly identical to the topological +properties of open sets how do we prove + + align:start position:0% +properties of open sets how do we prove + + + align:start position:0% +properties of open sets how do we prove +this it's not too bad I'm not going to + + align:start position:0% +this it's not too bad I'm not going to + + + align:start position:0% +this it's not too bad I'm not going to +actually do it the fact that the empty + + align:start position:0% +actually do it the fact that the empty + + + align:start position:0% +actually do it the fact that the empty +set and X are closed is just the proof + + align:start position:0% +set and X are closed is just the proof + + + align:start position:0% +set and X are closed is just the proof +that I did above for R right you can + + align:start position:0% +that I did above for R right you can + + + align:start position:0% +that I did above for R right you can +replace r with just any metric + + align:start position:0% +replace r with just any metric + + + align:start position:0% +replace r with just any metric +space uh and we have that this first + + align:start position:0% +space uh and we have that this first + + + align:start position:0% +space uh and we have that this first +property holds how about the other two + + align:start position:0% +property holds how about the other two + + + align:start position:0% +property holds how about the other two +well for the other two I'm just going to + + align:start position:0% +well for the other two I'm just going to + + + align:start position:0% +well for the other two I'm just going to +quickly note what are known as the + + align:start position:0% +quickly note what are known as the + + + align:start position:0% +quickly note what are known as the +Morgan's + + align:start position:0% + + + + align:start position:0% + +laws so this is is a nice Lemma from met + + align:start position:0% +laws so this is is a nice Lemma from met + + + align:start position:0% +laws so this is is a nice Lemma from met +from set + + align:start position:0% +from set + + + align:start position:0% +from set +theory these are known as de Morgan's + + align:start position:0% + + + + align:start position:0% + +laws going to switch which talk I'm + + align:start position:0% + + + + align:start position:0% + +using this + + align:start position:0% +using this + + + align:start position:0% +using this +states that the complement of a + + align:start position:0% + + + + align:start position:0% + +union is the intersection of the + + align:start position:0% +union is the intersection of the + + + align:start position:0% +union is the intersection of the +complements so I and a + + align:start position:0% +complements so I and a + + + align:start position:0% +complements so I and a +and + + align:start position:0% + + + + align:start position:0% + +similarly the complement of an + + align:start position:0% +similarly the complement of an + + + align:start position:0% +similarly the complement of an +intersection UI + + align:start position:0% +intersection UI + + + align:start position:0% +intersection UI +complement I in a is equal to the union + + align:start position:0% +complement I in a is equal to the union + + + align:start position:0% +complement I in a is equal to the union +of the + + align:start position:0% + + + + align:start position:0% + +complements these are known as de + + align:start position:0% +complements these are known as de + + + align:start position:0% +complements these are known as de +Morgan's laws they make relative sense + + align:start position:0% +Morgan's laws they make relative sense + + + align:start position:0% +Morgan's laws they make relative sense +you can prove them for two sets as + + align:start position:0% +you can prove them for two sets as + + + align:start position:0% +you can prove them for two sets as +opposed to infinitely many of them but + + align:start position:0% +opposed to infinitely many of them but + + + align:start position:0% +opposed to infinitely many of them but +once you have these two properties then + + align:start position:0% +once you have these two properties then + + + align:start position:0% +once you have these two properties then +you can rewrite these two properties in + + align:start position:0% +you can rewrite these two properties in + + + align:start position:0% +you can rewrite these two properties in +terms of open open sets that's why + + align:start position:0% +terms of open open sets that's why + + + align:start position:0% +terms of open open sets that's why +there's this Duality right I can write + + align:start position:0% +there's this Duality right I can write + + + align:start position:0% +there's this Duality right I can write +the intersection of closed sets as the + + align:start position:0% +the intersection of closed sets as the + + + align:start position:0% +the intersection of closed sets as the +union of open + + align:start position:0% +union of open + + + align:start position:0% +union of open +sets so that's uh that's how you apply + + align:start position:0% +sets so that's uh that's how you apply + + + align:start position:0% +sets so that's uh that's how you apply +to Morgan's laws and I'm not going to + + align:start position:0% +to Morgan's laws and I'm not going to + + + align:start position:0% +to Morgan's laws and I'm not going to +prove that or I'm not going to prove + + align:start position:0% +prove that or I'm not going to prove + + + align:start position:0% +prove that or I'm not going to prove +these topological properties this is in + + align:start position:0% +these topological properties this is in + + + align:start position:0% +these topological properties this is in +the lecture notes but I do want to knowe + + align:start position:0% +the lecture notes but I do want to knowe + + + align:start position:0% +the lecture notes but I do want to knowe +you could do everything in terms of + + align:start position:0% +you could do everything in terms of + + + align:start position:0% +you could do everything in terms of +closed sets if you really truly wanted + + align:start position:0% +closed sets if you really truly wanted + + + align:start position:0% +closed sets if you really truly wanted +to we just don't because open sets are + + align:start position:0% +to we just don't because open sets are + + + align:start position:0% +to we just don't because open sets are +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +nice okay we'll show why some of those + + align:start position:0% +nice okay we'll show why some of those + + + align:start position:0% +nice okay we'll show why some of those +things are actually nice uh what more + + align:start position:0% +things are actually nice uh what more + + + align:start position:0% +things are actually nice uh what more +things do I want to know okay + + align:start position:0% +things do I want to know okay + + + align:start position:0% +things do I want to know okay +cool uh now I want to State some + + align:start position:0% +cool uh now I want to State some + + + align:start position:0% +cool uh now I want to State some +specific examples of open sets and + + align:start position:0% +specific examples of open sets and + + + align:start position:0% +specific examples of open sets and +Metric baces which we can already do + + align:start position:0% +Metric baces which we can already do + + + align:start position:0% +Metric baces which we can already do +quite a bit + + align:start position:0% +quite a bit + + + align:start position:0% +quite a bit +of + + align:start position:0% +of + + + align:start position:0% +of +example uh one thing did I erase it + + align:start position:0% +example uh one thing did I erase it + + + align:start position:0% +example uh one thing did I erase it +already I think I oh wait no I did it + + align:start position:0% +already I think I oh wait no I did it + + + align:start position:0% +already I think I oh wait no I did it +here uh I did it where did I do it oh I + + align:start position:0% +here uh I did it where did I do it oh I + + + align:start position:0% +here uh I did it where did I do it oh I +did it at the very top uh the ball of + + align:start position:0% +did it at the very top uh the ball of + + + align:start position:0% +did it at the very top uh the ball of +radius Epsilon around a is sometimes + + align:start position:0% +radius Epsilon around a is sometimes + + + align:start position:0% +radius Epsilon around a is sometimes +referred to as an open ball but you + + align:start position:0% +referred to as an open ball but you + + + align:start position:0% +referred to as an open ball but you +should prove that the ball is in fact + + align:start position:0% +should prove that the ball is in fact + + + align:start position:0% +should prove that the ball is in fact +open which will be our first + + align:start position:0% +open which will be our first + + + align:start position:0% +open which will be our first +example so + + align:start position:0% +example so + + + align:start position:0% +example so +given some point x in your metric Space + + align:start position:0% +given some point x in your metric Space + + + align:start position:0% +given some point x in your metric Space +X and Epsilon bigger than + + align:start position:0% +X and Epsilon bigger than + + + align:start position:0% +X and Epsilon bigger than +zero we have that the ball of radius + + align:start position:0% +zero we have that the ball of radius + + + align:start position:0% +zero we have that the ball of radius +Epsilon round + + align:start position:0% +Epsilon round + + + align:start position:0% +Epsilon round +X is + + align:start position:0% +X is + + + align:start position:0% +X is +open how do we do this well we choose an + + align:start position:0% +open how do we do this well we choose an + + + align:start position:0% +open how do we do this well we choose an +arbitrary point in your ball of radius + + align:start position:0% +arbitrary point in your ball of radius + + + align:start position:0% +arbitrary point in your ball of radius +Epsilon right so + + align:start position:0% +Epsilon right so + + + align:start position:0% +Epsilon right so +proof uh + + align:start position:0% +proof uh + + + align:start position:0% +proof uh +choose some + + align:start position:0% +choose some + + + align:start position:0% +choose some +y in the ball of radius Epsilon around + + align:start position:0% +y in the ball of radius Epsilon around + + + align:start position:0% +y in the ball of radius Epsilon around +X we want to find a ball of radius let's + + align:start position:0% +X we want to find a ball of radius let's + + + align:start position:0% +X we want to find a ball of radius let's +say Delta around y contained in the ball + + align:start position:0% +say Delta around y contained in the ball + + + align:start position:0% +say Delta around y contained in the ball +of radius Epsilon around X that's the + + align:start position:0% +of radius Epsilon around X that's the + + + align:start position:0% +of radius Epsilon around X that's the +definition of open uh open + + align:start position:0% +definition of open uh open + + + align:start position:0% +definition of open uh open +set well notice that the distance from X + + align:start position:0% +set well notice that the distance from X + + + align:start position:0% +set well notice that the distance from X +to + + align:start position:0% +to + + + align:start position:0% +to +Y is less than Epsilon by definition + + align:start position:0% +Y is less than Epsilon by definition + + + align:start position:0% +Y is less than Epsilon by definition +right because we're assuming that the + + align:start position:0% +right because we're assuming that the + + + align:start position:0% +right because we're assuming that the +distance between points in our ball is + + align:start position:0% +distance between points in our ball is + + + align:start position:0% +distance between points in our ball is +less than + + align:start position:0% +less than + + + align:start position:0% +less than +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +so let Delta be the distance from X to + + align:start position:0% +so let Delta be the distance from X to + + + align:start position:0% +so let Delta be the distance from X to +Y over + + align:start position:0% +Y over + + + align:start position:0% +Y over +two why does this work because then + + align:start position:0% +two why does this work because then + + + align:start position:0% +two why does this work because then +we'll + + align:start position:0% +we'll + + + align:start position:0% +we'll +notice that the ball of radius Delta + + align:start position:0% +notice that the ball of radius Delta + + + align:start position:0% +notice that the ball of radius Delta +around y has to be contained in the ball + + align:start position:0% +around y has to be contained in the ball + + + align:start position:0% +around y has to be contained in the ball +of radius Epsilon around X why is this + + align:start position:0% +of radius Epsilon around X why is this + + + align:start position:0% +of radius Epsilon around X why is this +true essentially the triangle inequality + + align:start position:0% +true essentially the triangle inequality + + + align:start position:0% +true essentially the triangle inequality +right we have a ball of radius Epsilon + + align:start position:0% + + + + align:start position:0% + +centered at + + align:start position:0% +centered at + + + align:start position:0% +centered at +X have a point Y + + align:start position:0% +X have a point Y + + + align:start position:0% +X have a point Y +here and I'm noting that the distance + + align:start position:0% +here and I'm noting that the distance + + + align:start position:0% +here and I'm noting that the distance +from here to here is Epsilon uh is less + + align:start position:0% +from here to here is Epsilon uh is less + + + align:start position:0% +from here to here is Epsilon uh is less +than Epsilon by definition and I'm just + + align:start position:0% +than Epsilon by definition and I'm just + + + align:start position:0% +than Epsilon by definition and I'm just +choosing a ball around + + align:start position:0% +choosing a ball around + + + align:start position:0% +choosing a ball around +y to be half of that + + align:start position:0% +y to be half of that + + + align:start position:0% +y to be half of that +distance and then you can apply the + + align:start position:0% +distance and then you can apply the + + + align:start position:0% +distance and then you can apply the +triangle inequality to show that this + + align:start position:0% +triangle inequality to show that this + + + align:start position:0% +triangle inequality to show that this +ball must actually be contained in the + + align:start position:0% +ball must actually be contained in the + + + align:start position:0% +ball must actually be contained in the +bigger + + align:start position:0% +bigger + + + align:start position:0% +bigger +one anyone want me to work through that + + align:start position:0% +one anyone want me to work through that + + + align:start position:0% +one anyone want me to work through that +I'm happy to + + align:start position:0% + + + + align:start position:0% + +oh wait + + align:start position:0% + + + + align:start position:0% + +one let me let me write it + + align:start position:0% +one let me let me write it + + + align:start position:0% +one let me let me write it +out uh you know I'll write it out on the + + align:start position:0% +out uh you know I'll write it out on the + + + align:start position:0% +out uh you know I'll write it out on the +backboard so + + align:start position:0% +backboard so + + + align:start position:0% +backboard so +let z b in the ball of radius Delta + + align:start position:0% +let z b in the ball of radius Delta + + + align:start position:0% +let z b in the ball of radius Delta +around + + align:start position:0% +around + + + align:start position:0% +around +y then we have that the distance from X + + align:start position:0% +y then we have that the distance from X + + + align:start position:0% +y then we have that the distance from X +to Z is less than equal to by the + + align:start position:0% +to Z is less than equal to by the + + + align:start position:0% +to Z is less than equal to by the +triangle inequality the distance from X + + align:start position:0% +triangle inequality the distance from X + + + align:start position:0% +triangle inequality the distance from X +to Y plus the distance from y to + + align:start position:0% +to Y plus the distance from y to + + + align:start position:0% +to Y plus the distance from y to +Z uh distance from X to + + align:start position:0% +Z uh distance from X to + + + align:start position:0% +Z uh distance from X to +Y and the distance from y to Z is less + + align:start position:0% +Y and the distance from y to Z is less + + + align:start position:0% +Y and the distance from y to Z is less +than the distance from X to Y over + + align:start position:0% + + + + align:start position:0% + +2 is this what I wanted to do epon Prim + + align:start position:0% + + + + align:start position:0% + +uh I should say no this is not what I + + align:start position:0% +uh I should say no this is not what I + + + align:start position:0% +uh I should say no this is not what I +wanted to + + align:start position:0% +wanted to + + + align:start position:0% +wanted to +do + + align:start position:0% +do + + + align:start position:0% +do +let let R be the distance from X to Y + + align:start position:0% +let let R be the distance from X to Y + + + align:start position:0% +let let R be the distance from X to Y +minus + + align:start position:0% +minus + + + align:start position:0% +minus +Epsilon then what we know is that the + + align:start position:0% +Epsilon then what we know is that the + + + align:start position:0% +Epsilon then what we know is that the +distance from y to Z is less than + + align:start position:0% + + + + align:start position:0% + +R what am I trying to say distance of Y + + align:start position:0% +R what am I trying to say distance of Y + + + align:start position:0% +R what am I trying to say distance of Y +to Z is less + + align:start position:0% +to Z is less + + + align:start position:0% +to Z is less +than or sorry this should be Epsilon + + align:start position:0% +than or sorry this should be Epsilon + + + align:start position:0% +than or sorry this should be Epsilon +minus the distance there we go and this + + align:start position:0% +minus the distance there we go and this + + + align:start position:0% +minus the distance there we go and this +is then less than Epsilon so this is in + + align:start position:0% +is then less than Epsilon so this is in + + + align:start position:0% +is then less than Epsilon so this is in +the lecture notes I would highly suggest + + align:start position:0% +the lecture notes I would highly suggest + + + align:start position:0% +the lecture notes I would highly suggest +drawing out the picture and working + + align:start position:0% +drawing out the picture and working + + + align:start position:0% +drawing out the picture and working +through it uh separately but Loosely + + align:start position:0% +through it uh separately but Loosely + + + align:start position:0% +through it uh separately but Loosely +speaking it's just this diagram on the + + align:start position:0% +speaking it's just this diagram on the + + + align:start position:0% +speaking it's just this diagram on the +right hand side it's an application of + + align:start position:0% +right hand side it's an application of + + + align:start position:0% +right hand side it's an application of +the triangle + + align:start position:0% +the triangle + + + align:start position:0% +the triangle +inequality okay so the ball of radius + + align:start position:0% +inequality okay so the ball of radius + + + align:start position:0% +inequality okay so the ball of radius +Epsilon is an open ball in + + align:start position:0% +Epsilon is an open ball in + + + align:start position:0% +Epsilon is an open ball in +fact you can State much more than this + + align:start position:0% +fact you can State much more than this + + + align:start position:0% +fact you can State much more than this +this is an optional problem on your + + align:start position:0% +this is an optional problem on your + + + align:start position:0% +this is an optional problem on your +second problem + + align:start position:0% +second problem + + + align:start position:0% +second problem +set and for the record I do suggest yall + + align:start position:0% +set and for the record I do suggest yall + + + align:start position:0% +set and for the record I do suggest yall +look at the + + align:start position:0% +look at the + + + align:start position:0% +look at the +um look at the optional problems because + + align:start position:0% +um look at the optional problems because + + + align:start position:0% +um look at the optional problems because +they will potentially give you more + + align:start position:0% +they will potentially give you more + + + align:start position:0% +they will potentially give you more +intuition even if you don't solve + + align:start position:0% +intuition even if you don't solve + + + align:start position:0% +intuition even if you don't solve +them + + align:start position:0% +them + + + align:start position:0% +them +um but yeah it's this is just one of + + align:start position:0% +um but yeah it's this is just one of + + + align:start position:0% +um but yeah it's this is just one of +those cases where this isn't a topology + + align:start position:0% +those cases where this isn't a topology + + + align:start position:0% +those cases where this isn't a topology +class so I'm not going to ask that y'all + + align:start position:0% +class so I'm not going to ask that y'all + + + align:start position:0% +class so I'm not going to ask that y'all +do a bunch of topology but it's pretty + + align:start position:0% +do a bunch of topology but it's pretty + + + align:start position:0% +do a bunch of topology but it's pretty +nice + + align:start position:0% +nice + + + align:start position:0% +nice +okay so just a small + + align:start position:0% + + + + align:start position:0% + +note any open set + + align:start position:0% + + + + align:start position:0% + +U contained in your metric + + align:start position:0% +U contained in your metric + + + align:start position:0% +U contained in your metric +space can be + + align:start position:0% + + + + align:start position:0% + +written + + align:start position:0% +written + + + align:start position:0% +written +as a union a potentially infinite Union + + align:start position:0% +as a union a potentially infinite Union + + + align:start position:0% +as a union a potentially infinite Union +of open + + align:start position:0% + + + + align:start position:0% + +balls I'll I'll outline briefly how to + + align:start position:0% +balls I'll I'll outline briefly how to + + + align:start position:0% +balls I'll I'll outline briefly how to +do this right now so if youall want to + + align:start position:0% +do this right now so if youall want to + + + align:start position:0% +do this right now so if youall want to +do it later you can do it um but theide + + align:start position:0% +do it later you can do it um but theide + + + align:start position:0% +do it later you can do it um but theide +idea is that for any single point in + + align:start position:0% +idea is that for any single point in + + + align:start position:0% +idea is that for any single point in +your open set there exists a ball of + + align:start position:0% +your open set there exists a ball of + + + align:start position:0% +your open set there exists a ball of +radius Epsilon around that point and + + align:start position:0% +radius Epsilon around that point and + + + align:start position:0% +radius Epsilon around that point and +then you can just take the union of all + + align:start position:0% +then you can just take the union of all + + + align:start position:0% +then you can just take the union of all +those balls of radius Epsilon the + + align:start position:0% +those balls of radius Epsilon the + + + align:start position:0% +those balls of radius Epsilon the +Epsilon might change for every single + + align:start position:0% +Epsilon might change for every single + + + align:start position:0% +Epsilon might change for every single +point but that doesn't matter right + + align:start position:0% +point but that doesn't matter right + + + align:start position:0% +point but that doesn't matter right +because it's an infinite Union so I'll + + align:start position:0% +because it's an infinite Union so I'll + + + align:start position:0% +because it's an infinite Union so I'll +let youall work through those + + align:start position:0% +let youall work through those + + + align:start position:0% +let youall work through those +details but this is just a proposition + + align:start position:0% +details but this is just a proposition + + + align:start position:0% +details but this is just a proposition +you can + + align:start position:0% +you can + + + align:start position:0% +you can +show okay let's also just prove what an + + align:start position:0% +show okay let's also just prove what an + + + align:start position:0% +show okay let's also just prove what an +example of a Clos set which will come + + align:start position:0% +example of a Clos set which will come + + + align:start position:0% +example of a Clos set which will come +important for next + + align:start position:0% +important for next + + + align:start position:0% +important for next +time it's just an example + + align:start position:0% +time it's just an example + + + align:start position:0% +time it's just an example +x uh sorry I should say let X be a point + + align:start position:0% +x uh sorry I should say let X be a point + + + align:start position:0% +x uh sorry I should say let X be a point +in your metric + + align:start position:0% +in your metric + + + align:start position:0% +in your metric +space then the set + + align:start position:0% +space then the set + + + align:start position:0% +space then the set +X is + + align:start position:0% +X is + + + align:start position:0% +X is +closed so this is just a singular point + + align:start position:0% +closed so this is just a singular point + + + align:start position:0% +closed so this is just a singular point +in your metric space how we're going to + + align:start position:0% +in your metric space how we're going to + + + align:start position:0% +in your metric space how we're going to +prove this well we only have one + + align:start position:0% +prove this well we only have one + + + align:start position:0% +prove this well we only have one +definition of closed we have that it's + + align:start position:0% +definition of closed we have that it's + + + align:start position:0% +definition of closed we have that it's +the complement or the complement is open + + align:start position:0% +the complement or the complement is open + + + align:start position:0% +the complement or the complement is open +right so uh proof + + align:start position:0% + + + + align:start position:0% + +consider the complement of + + align:start position:0% + + + + align:start position:0% + +X which is X not including + + align:start position:0% +X which is X not including + + + align:start position:0% +X which is X not including +X and + + align:start position:0% +X and + + + align:start position:0% +X and +let y be a point + + align:start position:0% +let y be a point + + + align:start position:0% +let y be a point +here what we want to show is that + + align:start position:0% +here what we want to show is that + + + align:start position:0% +here what we want to show is that +there's a ball of radius Epsilon I want + + align:start position:0% +there's a ball of radius Epsilon I want + + + align:start position:0% +there's a ball of radius Epsilon I want +to show around + + align:start position:0% +to show around + + + align:start position:0% +to show around +y or not in subset of X not including X + + align:start position:0% + + + + align:start position:0% + +let's draw a picture of what this should + + align:start position:0% +let's draw a picture of what this should + + + align:start position:0% +let's draw a picture of what this should +actually look like + + align:start position:0% +actually look like + + + align:start position:0% +actually look like +right uh well I didn't want to do that + + align:start position:0% +right uh well I didn't want to do that + + + align:start position:0% +right uh well I didn't want to do that +here's our metric + + align:start position:0% +here's our metric + + + align:start position:0% +here's our metric +space here's our singular point x and + + align:start position:0% +space here's our singular point x and + + + align:start position:0% +space here's our singular point x and +here's our Point let's say y we want to + + align:start position:0% +here's our Point let's say y we want to + + + align:start position:0% +here's our Point let's say y we want to +choose a ball around + + align:start position:0% +choose a ball around + + + align:start position:0% +choose a ball around +y that doesn't contain X how can we do + + align:start position:0% + + + + align:start position:0% + +it anyone you could choose whatever + + align:start position:0% +it anyone you could choose whatever + + + align:start position:0% +it anyone you could choose whatever +Epsilon you want so it's a question of + + align:start position:0% +Epsilon you want so it's a question of + + + align:start position:0% +Epsilon you want so it's a question of +what Epsilon want to + + align:start position:0% + + + + align:start position:0% + +choose we can choose Epsilon to be the + + align:start position:0% +choose we can choose Epsilon to be the + + + align:start position:0% +choose we can choose Epsilon to be the +half the distance between X and Y I + + align:start position:0% +half the distance between X and Y I + + + align:start position:0% +half the distance between X and Y I +think that's what I was mixing up on the + + align:start position:0% +think that's what I was mixing up on the + + + align:start position:0% +think that's what I was mixing up on the +other proof but it's in the lecture + + align:start position:0% +other proof but it's in the lecture + + + align:start position:0% +other proof but it's in the lecture +notes so I'll let you all do the other + + align:start position:0% +notes so I'll let you all do the other + + + align:start position:0% +notes so I'll let you all do the other +one but + + align:start position:0% +one but + + + align:start position:0% +one but +um choose + + align:start position:0% +um choose + + + align:start position:0% +um choose +Epsilon to be the distance from X to + + align:start position:0% +Epsilon to be the distance from X to + + + align:start position:0% +Epsilon to be the distance from X to +Y over + + align:start position:0% +Y over + + + align:start position:0% +Y over +two and then pictorially we have that + + align:start position:0% +two and then pictorially we have that + + + align:start position:0% +two and then pictorially we have that +it's you know that's rest of the problem + + align:start position:0% +it's you know that's rest of the problem + + + align:start position:0% +it's you know that's rest of the problem +but let's actually work through the + + align:start position:0% +but let's actually work through the + + + align:start position:0% +but let's actually work through the +details + + align:start position:0% +details + + + align:start position:0% +details +so then let Z be in your ball of radius + + align:start position:0% +so then let Z be in your ball of radius + + + align:start position:0% +so then let Z be in your ball of radius +Epsilon around + + align:start position:0% +Epsilon around + + + align:start position:0% +Epsilon around +y then we want to show that Z cannot be + + align:start position:0% +y then we want to show that Z cannot be + + + align:start position:0% +y then we want to show that Z cannot be +X + + align:start position:0% +X + + + align:start position:0% +X +right well notice this implies that the + + align:start position:0% +right well notice this implies that the + + + align:start position:0% +right well notice this implies that the +distance from y to + + align:start position:0% +distance from y to + + + align:start position:0% +distance from y to +Z has to be less + + align:start position:0% +Z has to be less + + + align:start position:0% +Z has to be less +than Epsilon right this is by + + align:start position:0% +than Epsilon right this is by + + + align:start position:0% +than Epsilon right this is by +construction but what can we can we get + + align:start position:0% +construction but what can we can we get + + + align:start position:0% +construction but what can we can we get +a lower bound on this we can we can note + + align:start position:0% +a lower bound on this we can we can note + + + align:start position:0% +a lower bound on this we can we can note +that the distance from I want to make + + align:start position:0% +that the distance from I want to make + + + align:start position:0% +that the distance from I want to make +sure I'm getting this + + align:start position:0% + + + + align:start position:0% + +right r + + align:start position:0% +right r + + + align:start position:0% +right r +x actually you know I'll do this + + align:start position:0% +x actually you know I'll do this + + + align:start position:0% +x actually you know I'll do this +directly or I'll do this by + + align:start position:0% + + + + align:start position:0% + +contradiction suppose for the sake of + + align:start position:0% +contradiction suppose for the sake of + + + align:start position:0% +contradiction suppose for the sake of +contradiction X was in the ball of + + align:start position:0% +contradiction X was in the ball of + + + align:start position:0% +contradiction X was in the ball of +radius Epsilon around y then this would + + align:start position:0% +radius Epsilon around y then this would + + + align:start position:0% +radius Epsilon around y then this would +imply that the distance from X to + + align:start position:0% +imply that the distance from X to + + + align:start position:0% +imply that the distance from X to +Y is less than + + align:start position:0% +Y is less than + + + align:start position:0% +Y is less than +Epsilon but this can't be the case + + align:start position:0% +Epsilon but this can't be the case + + + align:start position:0% +Epsilon but this can't be the case +because again we're assuming that the + + align:start position:0% +because again we're assuming that the + + + align:start position:0% +because again we're assuming that the +distance that + + align:start position:0% +distance that + + + align:start position:0% +distance that +Epsilon is the distance from X to Y over + + align:start position:0% +Epsilon is the distance from X to Y over + + + align:start position:0% +Epsilon is the distance from X to Y over +2 and the distance from X to Y cannot be + + align:start position:0% +2 and the distance from X to Y cannot be + + + align:start position:0% +2 and the distance from X to Y cannot be +less than the distance from X to Y over + + align:start position:0% +less than the distance from X to Y over + + + align:start position:0% +less than the distance from X to Y over +2 so that is our + + align:start position:0% + + + + align:start position:0% + +contradiction I'll make one more small + + align:start position:0% +contradiction I'll make one more small + + + align:start position:0% +contradiction I'll make one more small +note here which will come important for + + align:start position:0% +note here which will come important for + + + align:start position:0% +note here which will come important for +Tuesday which is as opposed to looking + + align:start position:0% +Tuesday which is as opposed to looking + + + align:start position:0% +Tuesday which is as opposed to looking +at a singular point you can do this with + + align:start position:0% +at a singular point you can do this with + + + align:start position:0% +at a singular point you can do this with +a finite Union of points right and the + + align:start position:0% +a finite Union of points right and the + + + align:start position:0% +a finite Union of points right and the +argument would be essentially the same + + align:start position:0% +argument would be essentially the same + + + align:start position:0% +argument would be essentially the same +as our finite intersection of open sets + + align:start position:0% +as our finite intersection of open sets + + + align:start position:0% +as our finite intersection of open sets +argument you have a finite Union of open + + align:start position:0% +argument you have a finite Union of open + + + align:start position:0% +argument you have a finite Union of open +sets or sorry a finite Union of closed + + align:start position:0% +sets or sorry a finite Union of closed + + + align:start position:0% +sets or sorry a finite Union of closed +things so it should be closed in fact + + align:start position:0% +things so it should be closed in fact + + + align:start position:0% +things so it should be closed in fact +you could use that to prove it + + align:start position:0% +you could use that to prove it + + + align:start position:0% +you could use that to prove it +immediately but you can also prove it + + align:start position:0% +immediately but you can also prove it + + + align:start position:0% +immediately but you can also prove it +directly like + + align:start position:0% +directly like + + + align:start position:0% +directly like +this + + align:start position:0% +this + + + align:start position:0% +this +okay so now what we're going to do is + + align:start position:0% +okay so now what we're going to do is + + + align:start position:0% +okay so now what we're going to do is +talk about how this definition of open + + align:start position:0% +talk about how this definition of open + + + align:start position:0% +talk about how this definition of open +set that's relates to convergent + + align:start position:0% +set that's relates to convergent + + + align:start position:0% +set that's relates to convergent +sequences and to um and to + + align:start position:0% +sequences and to um and to + + + align:start position:0% +sequences and to um and to +continuity + + align:start position:0% + + + + align:start position:0% + +proposition let + + align:start position:0% +proposition let + + + align:start position:0% +proposition let +xn to do this I'm going to do it in the + + align:start position:0% +xn to do this I'm going to do it in the + + + align:start position:0% +xn to do this I'm going to do it in the +real numbers but note that everything + + align:start position:0% +real numbers but note that everything + + + align:start position:0% +real numbers but note that everything +can be done in your metric bace I just + + align:start position:0% +can be done in your metric bace I just + + + align:start position:0% +can be done in your metric bace I just +want to use the notation from the real + + align:start position:0% +want to use the notation from the real + + + align:start position:0% +want to use the notation from the real +numbers let xn be a + + align:start position:0% +numbers let xn be a + + + align:start position:0% +numbers let xn be a +sequence am I holding it backwards I am + + align:start position:0% +sequence am I holding it backwards I am + + + align:start position:0% +sequence am I holding it backwards I am +in + + align:start position:0% +in + + + align:start position:0% +in +R uh that converges to + + align:start position:0% + + + + align:start position:0% + +X so this is true I claim if and only + + align:start position:0% +X so this is true I claim if and only + + + align:start position:0% +X so this is true I claim if and only +if for all Epsilon bigger than + + align:start position:0% +if for all Epsilon bigger than + + + align:start position:0% +if for all Epsilon bigger than +zero all but finitely + + align:start position:0% + + + + align:start position:0% + +many x i are in + + align:start position:0% + + + + align:start position:0% + +x - + + align:start position:0% +x - + + + align:start position:0% +x - +Epsilon to X Plus Epsilon so this is the + + align:start position:0% +Epsilon to X Plus Epsilon so this is the + + + align:start position:0% +Epsilon to X Plus Epsilon so this is the +ball of radius Epsilon around X right + + align:start position:0% +ball of radius Epsilon around X right + + + align:start position:0% +ball of radius Epsilon around X right +how do we prove this if and only if + + align:start position:0% +how do we prove this if and only if + + + align:start position:0% +how do we prove this if and only if +proof well okay I should say convergent + + align:start position:0% +proof well okay I should say convergent + + + align:start position:0% +proof well okay I should say convergent +sequence let's prove the forward + + align:start position:0% +sequence let's prove the forward + + + align:start position:0% +sequence let's prove the forward +Direction first + + align:start position:0% + + + + align:start position:0% + +so if xn is convergent then for all + + align:start position:0% +so if xn is convergent then for all + + + align:start position:0% +so if xn is convergent then for all +Epsilon bigger than zero there exists an + + align:start position:0% +Epsilon bigger than zero there exists an + + + align:start position:0% +Epsilon bigger than zero there exists an +n in the natural numbers + + align:start position:0% +n in the natural numbers + + + align:start position:0% +n in the natural numbers +such that the ball of radius Epsilon + + align:start position:0% +such that the ball of radius Epsilon + + + align:start position:0% +such that the ball of radius Epsilon +around + + align:start position:0% +around + + + align:start position:0% +around +x uh such that I should say such that + + align:start position:0% +x uh such that I should say such that + + + align:start position:0% +x uh such that I should say such that +for + + align:start position:0% +for + + + align:start position:0% +for +all n bigger than or equal to + + align:start position:0% +all n bigger than or equal to + + + align:start position:0% +all n bigger than or equal to +n the uh xn is in the ball of radius + + align:start position:0% +n the uh xn is in the ball of radius + + + align:start position:0% +n the uh xn is in the ball of radius +Epsilon X Plus + + align:start position:0% +Epsilon X Plus + + + align:start position:0% +Epsilon X Plus +Epsilon as this is true because the + + align:start position:0% +Epsilon as this is true because the + + + align:start position:0% +Epsilon as this is true because the +distance from xn to X is less than + + align:start position:0% +distance from xn to X is less than + + + align:start position:0% +distance from xn to X is less than +Epsilon this is just the open set way to + + align:start position:0% +Epsilon this is just the open set way to + + + align:start position:0% +Epsilon this is just the open set way to +view it right and this capital N notice + + align:start position:0% +view it right and this capital N notice + + + align:start position:0% +view it right and this capital N notice +that there are only Finly many terms + + align:start position:0% +that there are only Finly many terms + + + align:start position:0% +that there are only Finly many terms +less than it so this shows that + + align:start position:0% +less than it so this shows that + + + align:start position:0% +less than it so this shows that +infinitely many of the terms are in this + + align:start position:0% +infinitely many of the terms are in this + + + align:start position:0% +infinitely many of the terms are in this +open set and in fact only finitely many + + align:start position:0% +open set and in fact only finitely many + + + align:start position:0% +open set and in fact only finitely many +are outside of it so that proves the + + align:start position:0% +are outside of it so that proves the + + + align:start position:0% +are outside of it so that proves the +forward Direction let's prove the + + align:start position:0% +forward Direction let's prove the + + + align:start position:0% +forward Direction let's prove the +opposite + + align:start position:0% + + + + align:start position:0% + +direction + + align:start position:0% +direction + + + align:start position:0% +direction +uh + + align:start position:0% +uh + + + align:start position:0% +uh +suppose or I should + + align:start position:0% +suppose or I should + + + align:start position:0% +suppose or I should +write suppose + + align:start position:0% +write suppose + + + align:start position:0% +write suppose +uh for all Epsilon bigger than + + align:start position:0% +uh for all Epsilon bigger than + + + align:start position:0% +uh for all Epsilon bigger than +zero all but finitely + + align:start position:0% + + + + align:start position:0% + +many + + align:start position:0% +many + + + align:start position:0% +many +many + + align:start position:0% +many + + + align:start position:0% +many +XI are + + align:start position:0% +XI are + + + align:start position:0% +XI are +in x - Epsilon to X Plus + + align:start position:0% +in x - Epsilon to X Plus + + + align:start position:0% +in x - Epsilon to X Plus +Epsilon I want to choose a sequence that + + align:start position:0% +Epsilon I want to choose a sequence that + + + align:start position:0% +Epsilon I want to choose a sequence that +will converge to X then + + align:start position:0% +will converge to X then + + + align:start position:0% +will converge to X then +right well how can we do that we can + + align:start position:0% +right well how can we do that we can + + + align:start position:0% +right well how can we do that we can +construct a subsequence that is going to + + align:start position:0% +construct a subsequence that is going to + + + align:start position:0% +construct a subsequence that is going to +be convergent and if it's remember a + + align:start position:0% +be convergent and if it's remember a + + + align:start position:0% +be convergent and if it's remember a +subsequence if it's convergent converges + + align:start position:0% +subsequence if it's convergent converges + + + align:start position:0% +subsequence if it's convergent converges +to what the original sequence converges + + align:start position:0% +to what the original sequence converges + + + align:start position:0% +to what the original sequence converges +to right so this is where we're using a + + align:start position:0% +to right so this is where we're using a + + + align:start position:0% +to right so this is where we're using a +fact from earlier that we + + align:start position:0% +fact from earlier that we + + + align:start position:0% +fact from earlier that we +proved okay so suppose Epsilon is 1/ n + + align:start position:0% +proved okay so suppose Epsilon is 1/ n + + + align:start position:0% +proved okay so suppose Epsilon is 1/ n +for n and the natural numbers or I'll + + align:start position:0% +for n and the natural numbers or I'll + + + align:start position:0% +for n and the natural numbers or I'll +say + + align:start position:0% +say + + + align:start position:0% +say +m + + align:start position:0% +m + + + align:start position:0% +m +then + + align:start position:0% +then + + + align:start position:0% +then +choose X n + + align:start position:0% +choose X n + + + align:start position:0% +choose X n +m in the ball of radius Epsilon so 1 / M + + align:start position:0% +m in the ball of radius Epsilon so 1 / M + + + align:start position:0% +m in the ball of radius Epsilon so 1 / M +to x + 1 + + align:start position:0% +to x + 1 + + + align:start position:0% +to x + 1 +M what does this tell us I claim that + + align:start position:0% +M what does this tell us I claim that + + + align:start position:0% +M what does this tell us I claim that +this convergent sequence converges to + + align:start position:0% +this convergent sequence converges to + + + align:start position:0% +this convergent sequence converges to +X + + align:start position:0% +X + + + align:start position:0% +X +well to show that we need to write down + + align:start position:0% +well to show that we need to write down + + + align:start position:0% +well to show that we need to write down +the + + align:start position:0% + + + + align:start position:0% + +definition when professor riguez was + + align:start position:0% +definition when professor riguez was + + + align:start position:0% +definition when professor riguez was +erasing the board he'd always tell some + + align:start position:0% +erasing the board he'd always tell some + + + align:start position:0% +erasing the board he'd always tell some +joke but I don't have any jokes right + + align:start position:0% +joke but I don't have any jokes right + + + align:start position:0% +joke but I don't have any jokes right +now + + align:start position:0% + + + + align:start position:0% + +unfortunately though he would do them + + align:start position:0% +unfortunately though he would do them + + + align:start position:0% +unfortunately though he would do them +two at a time so he could actually have + + align:start position:0% +two at a time so he could actually have + + + align:start position:0% +two at a time so he could actually have +time to actually say the joke before he + + align:start position:0% +time to actually say the joke before he + + + align:start position:0% +time to actually say the joke before he +finished okay so we want to show that X + + align:start position:0% +finished okay so we want to show that X + + + align:start position:0% +finished okay so we want to show that X +and M converges to X right proof for all + + align:start position:0% +and M converges to X right proof for all + + + align:start position:0% +and M converges to X right proof for all +Epsilon bigger than + + align:start position:0% +Epsilon bigger than + + + align:start position:0% +Epsilon bigger than +zero we can choose + + align:start position:0% + + + + align:start position:0% + +M uh large enough + + align:start position:0% + + + + align:start position:0% + +or I should say capital + + align:start position:0% +or I should say capital + + + align:start position:0% +or I should say capital +M such that for all n m bigger than or + + align:start position:0% +M such that for all n m bigger than or + + + align:start position:0% +M such that for all n m bigger than or +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +M we have that uh 1 / n m is less than + + align:start position:0% +M we have that uh 1 / n m is less than + + + align:start position:0% +M we have that uh 1 / n m is less than +Epsilon right because epsilon's bigger + + align:start position:0% +Epsilon right because epsilon's bigger + + + align:start position:0% +Epsilon right because epsilon's bigger +than zero I can find a large enough + + align:start position:0% +than zero I can find a large enough + + + align:start position:0% +than zero I can find a large enough +natural number such that one over that + + align:start position:0% +natural number such that one over that + + + align:start position:0% +natural number such that one over that +natural number is less than Epsilon + + align:start position:0% +natural number is less than Epsilon + + + align:start position:0% +natural number is less than Epsilon +that's our it's a factor from real + + align:start position:0% +that's our it's a factor from real + + + align:start position:0% +that's our it's a factor from real +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +so what this tells + + align:start position:0% +so what this tells + + + align:start position:0% +so what this tells +us is that we + + align:start position:0% + + + + align:start position:0% + +know then that X and M or I should say + + align:start position:0% +know then that X and M or I should say + + + align:start position:0% +know then that X and M or I should say +uh yeah X and M is in xus epsilon to x + + + align:start position:0% +uh yeah X and M is in xus epsilon to x + + + + align:start position:0% +uh yeah X and M is in xus epsilon to x + +Epsilon because this is from X over 1 n + + align:start position:0% +Epsilon because this is from X over 1 n + + + align:start position:0% +Epsilon because this is from X over 1 n +m to x + 1 n m which is a subset of the + + align:start position:0% +m to x + 1 n m which is a subset of the + + + align:start position:0% +m to x + 1 n m which is a subset of the +B radius Epsilon by + + align:start position:0% +B radius Epsilon by + + + align:start position:0% +B radius Epsilon by +construction right because 1 nm is less + + align:start position:0% +construction right because 1 nm is less + + + align:start position:0% +construction right because 1 nm is less +than Epsilon so what this tells you is + + align:start position:0% +than Epsilon so what this tells you is + + + align:start position:0% +than Epsilon so what this tells you is +that the distance from xn M - x is less + + align:start position:0% +that the distance from xn M - x is less + + + align:start position:0% +that the distance from xn M - x is less +than Epsilon which implies that the + + align:start position:0% +than Epsilon which implies that the + + + align:start position:0% +than Epsilon which implies that the +convergent sequence or the convergent + + align:start position:0% +convergent sequence or the convergent + + + align:start position:0% +convergent sequence or the convergent +subsequence converges to X so to + + align:start position:0% +subsequence converges to X so to + + + align:start position:0% +subsequence converges to X so to +reiterate how the proof went we had a + + align:start position:0% +reiterate how the proof went we had a + + + align:start position:0% +reiterate how the proof went we had a +convergent sequence we had a subsequence + + align:start position:0% +convergent sequence we had a subsequence + + + align:start position:0% +convergent sequence we had a subsequence +that we showed converges to x and by + + align:start position:0% +that we showed converges to x and by + + + align:start position:0% +that we showed converges to x and by +what we showed earlier X must be the + + align:start position:0% +what we showed earlier X must be the + + + align:start position:0% +what we showed earlier X must be the +limit point of the original convergent + + align:start position:0% +limit point of the original convergent + + + align:start position:0% +limit point of the original convergent +sequence then so we're done + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right uh I won't write out the analogous + + align:start position:0% +right uh I won't write out the analogous + + + align:start position:0% +right uh I won't write out the analogous +statement for metric bases the you just + + align:start position:0% +statement for metric bases the you just + + + align:start position:0% +statement for metric bases the you just +change xus Epsilon to X Plus Epsilon + + align:start position:0% +change xus Epsilon to X Plus Epsilon + + + align:start position:0% +change xus Epsilon to X Plus Epsilon +with a ball of radius Epsilon um I just + + align:start position:0% +with a ball of radius Epsilon um I just + + + align:start position:0% +with a ball of radius Epsilon um I just +dated it in real real numbers because + + align:start position:0% +dated it in real real numbers because + + + align:start position:0% +dated it in real real numbers because +the I prefer the interval notation to + + align:start position:0% +the I prefer the interval notation to + + + align:start position:0% +the I prefer the interval notation to +think about it and it's a fact that like + + align:start position:0% +think about it and it's a fact that like + + + align:start position:0% +think about it and it's a fact that like +not everyone fully sees in real analysis + + align:start position:0% +not everyone fully sees in real analysis + + + align:start position:0% +not everyone fully sees in real analysis +because sometimes you don't know what an + + align:start position:0% +because sometimes you don't know what an + + + align:start position:0% +because sometimes you don't know what an +open set is in 100a it depends on who's + + align:start position:0% +open set is in 100a it depends on who's + + + align:start position:0% +open set is in 100a it depends on who's +teaching it + + align:start position:0% +teaching it + + + align:start position:0% +teaching it +realistically okay we're going to prove + + align:start position:0% +realistically okay we're going to prove + + + align:start position:0% +realistically okay we're going to prove +one more oh wait what do I want to + + align:start position:0% + + + + align:start position:0% + +say yeah okay this was just why I wanted + + align:start position:0% +say yeah okay this was just why I wanted + + + align:start position:0% +say yeah okay this was just why I wanted +to show that it's related to uh + + align:start position:0% +to show that it's related to uh + + + align:start position:0% +to show that it's related to uh +convergent sequences now what I'm going + + align:start position:0% +convergent sequences now what I'm going + + + align:start position:0% +convergent sequences now what I'm going +to do is show that it's related to + + align:start position:0% +to do is show that it's related to + + + align:start position:0% +to do is show that it's related to +continuous functions and I'm going to + + align:start position:0% +continuous functions and I'm going to + + + align:start position:0% +continuous functions and I'm going to +recall what that definition is because + + align:start position:0% +recall what that definition is because + + + align:start position:0% +recall what that definition is because +that can again be a little bit weird + + align:start position:0% +that can again be a little bit weird + + + align:start position:0% +that can again be a little bit weird +between metric spaces so a function f + + align:start position:0% +between metric spaces so a function f + + + align:start position:0% +between metric spaces so a function f +from a metric Space X to a metric space + + align:start position:0% +from a metric Space X to a metric space + + + align:start position:0% +from a metric Space X to a metric space +y let's say with metric DX + + align:start position:0% +y let's say with metric DX + + + align:start position:0% +y let's say with metric DX +and + + align:start position:0% +and + + + align:start position:0% +and +Dy is + + align:start position:0% + + + + align:start position:0% + +continuous if for all Epsilon bigger + + align:start position:0% +continuous if for all Epsilon bigger + + + align:start position:0% +continuous if for all Epsilon bigger +than + + align:start position:0% +than + + + align:start position:0% +than +zero there exists a + + align:start position:0% +zero there exists a + + + align:start position:0% +zero there exists a +Delta bigger than zero such that if the + + align:start position:0% +Delta bigger than zero such that if the + + + align:start position:0% +Delta bigger than zero such that if the +distance between two + + align:start position:0% +distance between two + + + align:start position:0% +distance between two +points X and Y is less than Delta then + + align:start position:0% +points X and Y is less than Delta then + + + align:start position:0% +points X and Y is less than Delta then +the distance in the metric space y of + + align:start position:0% +the distance in the metric space y of + + + align:start position:0% +the distance in the metric space y of +the images of X and + + align:start position:0% +the images of X and + + + align:start position:0% +the images of X and +Y is less than Epsilon this is the the + + align:start position:0% +Y is less than Epsilon this is the the + + + align:start position:0% +Y is less than Epsilon this is the the +definition of continuous in the metric + + align:start position:0% +definition of continuous in the metric + + + align:start position:0% +definition of continuous in the metric +bace + + align:start position:0% +bace + + + align:start position:0% +bace +setting and so now what we're going to + + align:start position:0% +setting and so now what we're going to + + + align:start position:0% +setting and so now what we're going to +do is prove a statement akin to + + align:start position:0% +do is prove a statement akin to + + + align:start position:0% +do is prove a statement akin to +convergent sequences but for continuity + + align:start position:0% +convergent sequences but for continuity + + + align:start position:0% +convergent sequences but for continuity +we can write the definition of + + align:start position:0% +we can write the definition of + + + align:start position:0% +we can write the definition of +continuity in terms of open sets and not + + align:start position:0% +continuity in terms of open sets and not + + + align:start position:0% +continuity in terms of open sets and not +only can we do that we can write + + align:start position:0% +only can we do that we can write + + + align:start position:0% +only can we do that we can write +continuity in terms of convergence of + + align:start position:0% +continuity in terms of convergence of + + + align:start position:0% +continuity in terms of convergence of +sequences so I'll do that right + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +theorem under all the same assumptions + + align:start position:0% +theorem under all the same assumptions + + + align:start position:0% +theorem under all the same assumptions +here I'm going to let X and Y be metric + + align:start position:0% +here I'm going to let X and Y be metric + + + align:start position:0% +here I'm going to let X and Y be metric +spaces with distances DX and + + align:start position:0% +spaces with distances DX and + + + align:start position:0% +spaces with distances DX and +Dy + + align:start position:0% + + + + align:start position:0% + +and yeah + + align:start position:0% +and yeah + + + align:start position:0% +and yeah +okay uh + + align:start position:0% +okay uh + + + align:start position:0% +okay uh +let claim uh F from X to + + align:start position:0% +let claim uh F from X to + + + align:start position:0% +let claim uh F from X to +Y is continuous at a point C in + + align:start position:0% +Y is continuous at a point C in + + + align:start position:0% +Y is continuous at a point C in +X + + align:start position:0% +X + + + align:start position:0% +X +if if and only if + + align:start position:0% + + + + align:start position:0% + +if xn is a sequence that converges to X + + align:start position:0% +if xn is a sequence that converges to X + + + align:start position:0% +if xn is a sequence that converges to X +then F of + + align:start position:0% +then F of + + + align:start position:0% +then F of +xn converges to F + + align:start position:0% +xn converges to F + + + align:start position:0% +xn converges to F +ofx this is my + + align:start position:0% +ofx this is my + + + align:start position:0% +ofx this is my +statement uh when I say continuous at + + align:start position:0% +statement uh when I say continuous at + + + align:start position:0% +statement uh when I say continuous at +the point C I mean just + + align:start position:0% +the point C I mean just + + + align:start position:0% +the point C I mean just +replace uh y with C here that means that + + align:start position:0% +replace uh y with C here that means that + + + align:start position:0% +replace uh y with C here that means that +this is continuous at every + + align:start position:0% +this is continuous at every + + + align:start position:0% +this is continuous at every +Point continuous at x and x and as + + align:start position:0% +Point continuous at x and x and as + + + align:start position:0% +Point continuous at x and x and as +continuous if it's continuous everywhere + + align:start position:0% +continuous if it's continuous everywhere + + + align:start position:0% +continuous if it's continuous everywhere +right this is the same as in real + + align:start position:0% +right this is the same as in real + + + align:start position:0% +right this is the same as in real +analysis we had get continuity at a + + align:start position:0% +analysis we had get continuity at a + + + align:start position:0% +analysis we had get continuity at a +point and continuity everywhere this is + + align:start position:0% +point and continuity everywhere this is + + + align:start position:0% +point and continuity everywhere this is +just continuity at a + + align:start position:0% +just continuity at a + + + align:start position:0% +just continuity at a +point okay + + align:start position:0% +point okay + + + align:start position:0% +point okay +proof I always prefer + + align:start position:0% +proof I always prefer + + + align:start position:0% +proof I always prefer +going the downwards Direction first so + + align:start position:0% +going the downwards Direction first so + + + align:start position:0% +going the downwards Direction first so +let + + align:start position:0% +let + + + align:start position:0% +let +F be continuous at C + + align:start position:0% + + + + align:start position:0% + +then by definition for all Epsilon + + align:start position:0% +then by definition for all Epsilon + + + align:start position:0% +then by definition for all Epsilon +bigger than zero there exists a Delta + + align:start position:0% +bigger than zero there exists a Delta + + + align:start position:0% +bigger than zero there exists a Delta +such that this implication holds what + + align:start position:0% +such that this implication holds what + + + align:start position:0% +such that this implication holds what +does this actually tell us well suppose + + align:start position:0% +does this actually tell us well suppose + + + align:start position:0% +does this actually tell us well suppose +we're going I'm going toose suppose the + + align:start position:0% +we're going I'm going toose suppose the + + + align:start position:0% +we're going I'm going toose suppose the +um uh thing in the second hypothesis + + align:start position:0% + + + + align:start position:0% + +suppose xn is a sequence in X that + + align:start position:0% +suppose xn is a sequence in X that + + + align:start position:0% +suppose xn is a sequence in X that +converges to X then what can I say well + + align:start position:0% +converges to X then what can I say well + + + align:start position:0% +converges to X then what can I say well +we know that there + + align:start position:0% +we know that there + + + align:start position:0% +we know that there +exists a sorry I should say to + + align:start position:0% + + + + align:start position:0% + +C then by definition of convergent + + align:start position:0% +C then by definition of convergent + + + align:start position:0% +C then by definition of convergent +sequence we know that for all Epsilon + + align:start position:0% +sequence we know that for all Epsilon + + + align:start position:0% +sequence we know that for all Epsilon +bigger than + + align:start position:0% +bigger than + + + align:start position:0% +bigger than +zero there exists an n in the natural + + align:start position:0% +zero there exists an n in the natural + + + align:start position:0% +zero there exists an n in the natural +numbers such that for all n bigger than + + align:start position:0% +numbers such that for all n bigger than + + + align:start position:0% +numbers such that for all n bigger than +or equal to + + align:start position:0% +or equal to + + + align:start position:0% +or equal to +n the distance from xn to C is less than + + align:start position:0% +n the distance from xn to C is less than + + + align:start position:0% +n the distance from xn to C is less than +Epsilon but we know that for all Epsilon + + align:start position:0% +Epsilon but we know that for all Epsilon + + + align:start position:0% +Epsilon but we know that for all Epsilon +bigger than + + align:start position:0% +bigger than + + + align:start position:0% +bigger than +zero furthermore + + align:start position:0% + + + + align:start position:0% + +there exists a Delta bigger than zero + + align:start position:0% +there exists a Delta bigger than zero + + + align:start position:0% +there exists a Delta bigger than zero +such that the distance from F of + + align:start position:0% +such that the distance from F of + + + align:start position:0% +such that the distance from F of +xn to F of + + align:start position:0% +xn to F of + + + align:start position:0% +xn to F of +C is less than Delta over two oh sorry + + align:start position:0% +C is less than Delta over two oh sorry + + + align:start position:0% +C is less than Delta over two oh sorry +not Delta over two just + + align:start position:0% +not Delta over two just + + + align:start position:0% +not Delta over two just +Delta uh is this no uh I should have re + + align:start position:0% +Delta uh is this no uh I should have re + + + align:start position:0% +Delta uh is this no uh I should have re +labeled this I should have said for all + + align:start position:0% +labeled this I should have said for all + + + align:start position:0% +labeled this I should have said for all +Delta bigger than zero there exists one + + align:start position:0% +Delta bigger than zero there exists one + + + align:start position:0% +Delta bigger than zero there exists one +such that this is less than Delta and + + align:start position:0% +such that this is less than Delta and + + + align:start position:0% +such that this is less than Delta and +then there exists an Epsilon bigger than + + align:start position:0% +then there exists an Epsilon bigger than + + + align:start position:0% +then there exists an Epsilon bigger than +zero such that no no I said it right the + + align:start position:0% +zero such that no no I said it right the + + + align:start position:0% +zero such that no no I said it right the +first time uh for all bigger than Z + + align:start position:0% +first time uh for all bigger than Z + + + align:start position:0% +first time uh for all bigger than Z +there exists a Delta bigger than zero + + align:start position:0% +there exists a Delta bigger than zero + + + align:start position:0% +there exists a Delta bigger than zero +such that this term is less than Delta + + align:start position:0% +such that this term is less than Delta + + + align:start position:0% +such that this term is less than Delta +and + + align:start position:0% +and + + + align:start position:0% +and +furthermore the distance between the + + align:start position:0% +furthermore the distance between the + + + align:start position:0% +furthermore the distance between the +images is less than Epsilon there we go + + align:start position:0% +images is less than Epsilon there we go + + + align:start position:0% +images is less than Epsilon there we go +that's what I meant to say and so what + + align:start position:0% +that's what I meant to say and so what + + + align:start position:0% +that's what I meant to say and so what +this tells you is that F of xn must + + align:start position:0% +this tells you is that F of xn must + + + align:start position:0% +this tells you is that F of xn must +converge to F of C right because there + + align:start position:0% +converge to F of C right because there + + + align:start position:0% +converge to F of C right because there +exists an n in the natural numbers such + + align:start position:0% +exists an n in the natural numbers such + + + align:start position:0% +exists an n in the natural numbers such +that the distance between the two points + + align:start position:0% +that the distance between the two points + + + align:start position:0% +that the distance between the two points +is less than Epsilon which is the + + align:start position:0% +is less than Epsilon which is the + + + align:start position:0% +is less than Epsilon which is the +definition of convergent + + align:start position:0% +definition of convergent + + + align:start position:0% +definition of convergent +sequence and then to prove the other + + align:start position:0% +sequence and then to prove the other + + + align:start position:0% +sequence and then to prove the other +direction uh I'm just going to State it + + align:start position:0% +direction uh I'm just going to State it + + + align:start position:0% +direction uh I'm just going to State it +because are running out of time no I'll + + align:start position:0% +because are running out of time no I'll + + + align:start position:0% +because are running out of time no I'll +write it out I'll write it out over + + align:start position:0% + + + + align:start position:0% + +here to proof the other direction we're + + align:start position:0% +here to proof the other direction we're + + + align:start position:0% +here to proof the other direction we're +going to use it by uh contradiction + + align:start position:0% +going to use it by uh contradiction + + + align:start position:0% +going to use it by uh contradiction +we're going to assume that it's not + + align:start position:0% +we're going to assume that it's not + + + align:start position:0% +we're going to assume that it's not +continuous at C and then choose a + + align:start position:0% +continuous at C and then choose a + + + align:start position:0% +continuous at C and then choose a +convergent sequence that uh or a + + align:start position:0% +convergent sequence that uh or a + + + align:start position:0% +convergent sequence that uh or a +sequence that doesn't + + align:start position:0% +sequence that doesn't + + + align:start position:0% +sequence that doesn't +converge or such that the images don't + + align:start position:0% +converge or such that the images don't + + + align:start position:0% +converge or such that the images don't +converge + + align:start position:0% + + + + align:start position:0% + +okay if and only + + align:start position:0% +okay if and only + + + align:start position:0% +okay if and only +if + + align:start position:0% +if + + + align:start position:0% +if +suppose f is not + + align:start position:0% +suppose f is not + + + align:start position:0% +suppose f is not +continuous this is the proof of the + + align:start position:0% +continuous this is the proof of the + + + align:start position:0% +continuous this is the proof of the +upwards + + align:start position:0% +upwards + + + align:start position:0% +upwards +Direction suppose it's not + + align:start position:0% +Direction suppose it's not + + + align:start position:0% +Direction suppose it's not +continuous at C what does this tell you + + align:start position:0% +continuous at C what does this tell you + + + align:start position:0% +continuous at C what does this tell you +well saying something is not continuous + + align:start position:0% +well saying something is not continuous + + + align:start position:0% +well saying something is not continuous +is a little bit weird but I'll State out + + align:start position:0% +is a little bit weird but I'll State out + + + align:start position:0% +is a little bit weird but I'll State out +what that definition means + + align:start position:0% +what that definition means + + + align:start position:0% +what that definition means +given some bigger than + + align:start position:0% +given some bigger than + + + align:start position:0% +given some bigger than +zero we know that there + + align:start position:0% + + + + align:start position:0% + +exists there exists an xn in the + + align:start position:0% +exists there exists an xn in the + + + align:start position:0% +exists there exists an xn in the +sequence such + + align:start position:0% +sequence such + + + align:start position:0% +sequence such +that the distance from + + align:start position:0% +that the distance from + + + align:start position:0% +that the distance from +xn to C get + + align:start position:0% + + + + align:start position:0% + +small uh I want to say one over n I'll + + align:start position:0% +small uh I want to say one over n I'll + + + align:start position:0% +small uh I want to say one over n I'll +just + + align:start position:0% +just + + + align:start position:0% +just +say less + + align:start position:0% +say less + + + align:start position:0% +say less +than given Epsilon bigger than Z there + + align:start position:0% +than given Epsilon bigger than Z there + + + align:start position:0% +than given Epsilon bigger than Z there +exists a Delta bigger than zero and an X + + align:start position:0% +exists a Delta bigger than zero and an X + + + align:start position:0% +exists a Delta bigger than zero and an X +in your sequence such that the distances + + align:start position:0% +in your sequence such that the distances + + + align:start position:0% +in your sequence such that the distances +get small so let's say 1/ + + align:start position:0% +get small so let's say 1/ + + + align:start position:0% +get small so let's say 1/ +n but the distances between the images + + align:start position:0% +n but the distances between the images + + + align:start position:0% +n but the distances between the images +of + + align:start position:0% +of + + + align:start position:0% +of +them F of C is bigger than + + align:start position:0% +them F of C is bigger than + + + align:start position:0% +them F of C is bigger than +Epsilon right because the the uh Contra + + align:start position:0% +Epsilon right because the the uh Contra + + + align:start position:0% +Epsilon right because the the uh Contra +uh the opposite would be if this was + + align:start position:0% +uh the opposite would be if this was + + + align:start position:0% +uh the opposite would be if this was +less than or equal to + + align:start position:0% +less than or equal to + + + align:start position:0% +less than or equal to +Epsilon right and so then what you can + + align:start position:0% +Epsilon right and so then what you can + + + align:start position:0% +Epsilon right and so then what you can +show is + + align:start position:0% +show is + + + align:start position:0% +show is +that therefore xn converges to C but F + + align:start position:0% +that therefore xn converges to C but F + + + align:start position:0% +that therefore xn converges to C but F +of + + align:start position:0% +of + + + align:start position:0% +of +xn does not converge to F of + + align:start position:0% +xn does not converge to F of + + + align:start position:0% +xn does not converge to F of +C we know that it doesn't converge to F + + align:start position:0% +C we know that it doesn't converge to F + + + align:start position:0% +C we know that it doesn't converge to F +of C because we just + + align:start position:0% +of C because we just + + + align:start position:0% +of C because we just +proved up here that if a sequence is to + + align:start position:0% +proved up here that if a sequence is to + + + align:start position:0% +proved up here that if a sequence is to +Converge All But finitely many of them + + align:start position:0% +Converge All But finitely many of them + + + align:start position:0% +Converge All But finitely many of them +I.E infinitely many of them or that's + + align:start position:0% +I.E infinitely many of them or that's + + + align:start position:0% +I.E infinitely many of them or that's +not quite the same but all but finitely + + align:start position:0% +not quite the same but all but finitely + + + align:start position:0% +not quite the same but all but finitely +many of them must exist in any ball of + + align:start position:0% +many of them must exist in any ball of + + + align:start position:0% +many of them must exist in any ball of +radius Epsilon right and we just showed + + align:start position:0% +radius Epsilon right and we just showed + + + align:start position:0% +radius Epsilon right and we just showed +here that there are in fact infinitely + + align:start position:0% +here that there are in fact infinitely + + + align:start position:0% +here that there are in fact infinitely +many that don't exist in a ball of + + align:start position:0% +many that don't exist in a ball of + + + align:start position:0% +many that don't exist in a ball of +radius + + align:start position:0% +radius + + + align:start position:0% +radius +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +so uh that proves the other + + align:start position:0% + + + + align:start position:0% + +direction this is known as sequential + + align:start position:0% +direction this is known as sequential + + + align:start position:0% +direction this is known as sequential +continuity sometimes if you want to + + align:start position:0% +continuity sometimes if you want to + + + align:start position:0% +continuity sometimes if you want to +study uh this in more generality as + + align:start position:0% +study uh this in more generality as + + + align:start position:0% +study uh this in more generality as +opposed to assuming continuous you can + + align:start position:0% +opposed to assuming continuous you can + + + align:start position:0% +opposed to assuming continuous you can +assume this this sort of definition on + + align:start position:0% +assume this this sort of definition on + + + align:start position:0% +assume this this sort of definition on +topological space and that's slightly + + align:start position:0% +topological space and that's slightly + + + align:start position:0% +topological space and that's slightly +different um but for metric spaces the + + align:start position:0% +different um but for metric spaces the + + + align:start position:0% +different um but for metric spaces the +two definitions are the same right which + + align:start position:0% +two definitions are the same right which + + + align:start position:0% +two definitions are the same right which +will be the case a lot of the time a lot + + align:start position:0% +will be the case a lot of the time a lot + + + align:start position:0% +will be the case a lot of the time a lot +of the time in this class A definition + + align:start position:0% +of the time in this class A definition + + + align:start position:0% +of the time in this class A definition +that's specific to metric spaces will + + align:start position:0% +that's specific to metric spaces will + + + align:start position:0% +that's specific to metric spaces will +imply other very useful + + align:start position:0% +imply other very useful + + + align:start position:0% +imply other very useful +definitions that might not hold in more + + align:start position:0% +definitions that might not hold in more + + + align:start position:0% +definitions that might not hold in more +generality + + align:start position:0% +generality + + + align:start position:0% +generality +okay I just have one more statement to + + align:start position:0% +okay I just have one more statement to + + + align:start position:0% +okay I just have one more statement to +show which is how continuity relates to + + align:start position:0% +show which is how continuity relates to + + + align:start position:0% +show which is how continuity relates to +open + + align:start position:0% +open + + + align:start position:0% +open +sets uh let me write out what this Sumo + + align:start position:0% +sets uh let me write out what this Sumo + + + align:start position:0% +sets uh let me write out what this Sumo +will be oh sorry I should have this is + + align:start position:0% +will be oh sorry I should have this is + + + align:start position:0% +will be oh sorry I should have this is +poor board manners I should have raised + + align:start position:0% +poor board manners I should have raised + + + align:start position:0% +poor board manners I should have raised +this in the with + + align:start position:0% +this in the with + + + align:start position:0% +this in the with +this + + align:start position:0% +this + + + align:start position:0% +this +okay + + align:start position:0% + + + + align:start position:0% + +okay just one more + + align:start position:0% + + + + align:start position:0% + +Lemma f is + + align:start position:0% +Lemma f is + + + align:start position:0% +Lemma f is +continuous at C if and only + + align:start position:0% +continuous at C if and only + + + align:start position:0% +continuous at C if and only +if oh I need to state a definition first + + align:start position:0% +if oh I need to state a definition first + + + align:start position:0% +if oh I need to state a definition first +I'll state it over + + align:start position:0% +I'll state it over + + + align:start position:0% +I'll state it over +here + + align:start position:0% +here + + + align:start position:0% +here +definition a + + align:start position:0% + + + + align:start position:0% + +neighborhood of a point + + align:start position:0% + + + + align:start position:0% + +Y is + + align:start position:0% +Y is + + + align:start position:0% +Y is +simply an open set that that contains + + align:start position:0% + + + + align:start position:0% + +y containing + + align:start position:0% + + + + align:start position:0% + +y for our purposes though you can just + + align:start position:0% +y for our purposes though you can just + + + align:start position:0% +y for our purposes though you can just +think of this open neighborhood as a + + align:start position:0% +think of this open neighborhood as a + + + align:start position:0% +think of this open neighborhood as a +ball right because I've stated that + + align:start position:0% +ball right because I've stated that + + + align:start position:0% +ball right because I've stated that +every uh open set can be written as a + + align:start position:0% +every uh open set can be written as a + + + align:start position:0% +every uh open set can be written as a +union of finitely of infinitely many + + align:start position:0% +union of finitely of infinitely many + + + align:start position:0% +union of finitely of infinitely many +balls so this is what a definition of a + + align:start position:0% +balls so this is what a definition of a + + + align:start position:0% +balls so this is what a definition of a +neighborhood is and that lets us State + + align:start position:0% +neighborhood is and that lets us State + + + align:start position:0% +neighborhood is and that lets us State +the Lemma which + + align:start position:0% +the Lemma which + + + align:start position:0% +the Lemma which +is for + + align:start position:0% +is for + + + align:start position:0% +is for +every open + + align:start position:0% + + + + align:start position:0% + +neighborhood + + align:start position:0% +neighborhood + + + align:start position:0% +neighborhood +neighborhood of Y oh sorry of f of C + + align:start position:0% +neighborhood of Y oh sorry of f of C + + + align:start position:0% +neighborhood of Y oh sorry of f of C +this will be our + + align:start position:0% + + + + align:start position:0% + +y then we have that the inverse image F + + align:start position:0% +y then we have that the inverse image F + + + align:start position:0% +y then we have that the inverse image F +inverse of f of oh sorry I should say + + align:start position:0% +inverse of f of oh sorry I should say + + + align:start position:0% +inverse of f of oh sorry I should say +every open neighborhood U of f of c f + + align:start position:0% +every open neighborhood U of f of c f + + + align:start position:0% +every open neighborhood U of f of c f +inverse of U Is An Open + + align:start position:0% + + + + align:start position:0% + +neighborhood of f of C sorry of C + + align:start position:0% +neighborhood of f of C sorry of C + + + align:start position:0% +neighborhood of f of C sorry of C +because we're in the inverse image okay + + align:start position:0% +because we're in the inverse image okay + + + align:start position:0% +because we're in the inverse image okay +has anyone seen this sort of definition + + align:start position:0% +has anyone seen this sort of definition + + + align:start position:0% +has anyone seen this sort of definition +before regarding open + + align:start position:0% +before regarding open + + + align:start position:0% +before regarding open +sets yeah um it doesn't come up all the + + align:start position:0% +sets yeah um it doesn't come up all the + + + align:start position:0% +sets yeah um it doesn't come up all the +time because it is essentially topology + + align:start position:0% +time because it is essentially topology + + + align:start position:0% +time because it is essentially topology +like if you take a topology class you + + align:start position:0% +like if you take a topology class you + + + align:start position:0% +like if you take a topology class you +would see this definition of this would + + align:start position:0% +would see this definition of this would + + + align:start position:0% +would see this definition of this would +be the definition of continuity in a + + align:start position:0% +be the definition of continuity in a + + + align:start position:0% +be the definition of continuity in a +topological class um but here we're + + align:start position:0% +topological class um but here we're + + + align:start position:0% +topological class um but here we're +going to actually prove it for a metric + + align:start position:0% +going to actually prove it for a metric + + + align:start position:0% +going to actually prove it for a metric +bace and because not all of you have + + align:start position:0% +bace and because not all of you have + + + align:start position:0% +bace and because not all of you have +seen it before we'll just go through + + align:start position:0% +seen it before we'll just go through + + + align:start position:0% +seen it before we'll just go through +that proof so + + align:start position:0% + + + + align:start position:0% + +proof we'll prove the downwards + + align:start position:0% +proof we'll prove the downwards + + + align:start position:0% +proof we'll prove the downwards +Direction so we have that f is + + align:start position:0% +Direction so we have that f is + + + align:start position:0% +Direction so we have that f is +continuous at C and I'm going to let + + align:start position:0% +continuous at C and I'm going to let + + + align:start position:0% +continuous at C and I'm going to let +you be an open + + align:start position:0% + + + + align:start position:0% + +neighborhood of f of c and so then I + + align:start position:0% +neighborhood of f of c and so then I + + + align:start position:0% +neighborhood of f of c and so then I +want to show that F inverse of C oh + + align:start position:0% +want to show that F inverse of C oh + + + align:start position:0% +want to show that F inverse of C oh +sorry F inverse of U Is An Open set of C + + align:start position:0% +sorry F inverse of U Is An Open set of C + + + align:start position:0% +sorry F inverse of U Is An Open set of C +open neighborhood of C right what I'm + + align:start position:0% +open neighborhood of C right what I'm + + + align:start position:0% +open neighborhood of C right what I'm +going to do + + align:start position:0% +going to do + + + align:start position:0% +going to do +instead uh instead of considering this + + align:start position:0% +instead uh instead of considering this + + + align:start position:0% +instead uh instead of considering this +entire open neighborhood I'm going to + + align:start position:0% +entire open neighborhood I'm going to + + + align:start position:0% +entire open neighborhood I'm going to +consider a ball of radius Epsilon right + + align:start position:0% +consider a ball of radius Epsilon right + + + align:start position:0% +consider a ball of radius Epsilon right +around F of C so we know because U is + + align:start position:0% +around F of C so we know because U is + + + align:start position:0% +around F of C so we know because U is +open we know that there exists an + + align:start position:0% +open we know that there exists an + + + align:start position:0% +open we know that there exists an +Epsilon bigger than zero such that the + + align:start position:0% +Epsilon bigger than zero such that the + + + align:start position:0% +Epsilon bigger than zero such that the +ball of radius + + align:start position:0% +ball of radius + + + align:start position:0% +ball of radius +Epsilon with metric + + align:start position:0% +Epsilon with metric + + + align:start position:0% +Epsilon with metric +Dy around uh F of + + align:start position:0% +Dy around uh F of + + + align:start position:0% +Dy around uh F of +C is contained in U right we can find a + + align:start position:0% +C is contained in U right we can find a + + + align:start position:0% +C is contained in U right we can find a +ball around F of C that such that it's + + align:start position:0% +ball around F of C that such that it's + + + align:start position:0% +ball around F of C that such that it's +contained in U because it's + + align:start position:0% +contained in U because it's + + + align:start position:0% +contained in U because it's +open what does this tell you well by + + align:start position:0% +open what does this tell you well by + + + align:start position:0% +open what does this tell you well by +continuity + + align:start position:0% + + + + align:start position:0% + +furthermore there exists a Delta bigger + + align:start position:0% +furthermore there exists a Delta bigger + + + align:start position:0% +furthermore there exists a Delta bigger +than zero such that uh such that the + + align:start position:0% +than zero such that uh such that the + + + align:start position:0% +than zero such that uh such that the +ball such that + + align:start position:0% +ball such that + + + align:start position:0% +ball such that +if the distance from X to C is less than + + align:start position:0% +if the distance from X to C is less than + + + align:start position:0% +if the distance from X to C is less than +Delta then the distance of f + + align:start position:0% +Delta then the distance of f + + + align:start position:0% +Delta then the distance of f +ofx to F of C is less than + + align:start position:0% +ofx to F of C is less than + + + align:start position:0% +ofx to F of C is less than +Epsilon what does this tell you well + + align:start position:0% +Epsilon what does this tell you well + + + align:start position:0% +Epsilon what does this tell you well +this tells you that the image of the + + align:start position:0% +this tells you that the image of the + + + align:start position:0% +this tells you that the image of the +ball of radius EP of radius Delta around + + align:start position:0% +ball of radius EP of radius Delta around + + + align:start position:0% +ball of radius EP of radius Delta around +C is contained in the ball of radius + + align:start position:0% +C is contained in the ball of radius + + + align:start position:0% +C is contained in the ball of radius +Epsilon around F of + + align:start position:0% +Epsilon around F of + + + align:start position:0% +Epsilon around F of +C right because if I look at the images + + align:start position:0% +C right because if I look at the images + + + align:start position:0% +C right because if I look at the images +of these points I'm going to get the + + align:start position:0% +of these points I'm going to get the + + + align:start position:0% +of these points I'm going to get the +distance is less than Epsilon around F + + align:start position:0% +distance is less than Epsilon around F + + + align:start position:0% +distance is less than Epsilon around F +of c and what you can check I won't + + align:start position:0% +of c and what you can check I won't + + + align:start position:0% +of c and what you can check I won't +State this right now or I won't prove it + + align:start position:0% +State this right now or I won't prove it + + + align:start position:0% +State this right now or I won't prove it +but you can check that if I do F inverse + + align:start position:0% +but you can check that if I do F inverse + + + align:start position:0% +but you can check that if I do F inverse +here it's going to be contained in F + + align:start position:0% +here it's going to be contained in F + + + align:start position:0% +here it's going to be contained in F +inverse here + + align:start position:0% +inverse here + + + align:start position:0% +inverse here +why is this helpful because this is a + + align:start position:0% +why is this helpful because this is a + + + align:start position:0% +why is this helpful because this is a +subset of f inverse of U so what we've + + align:start position:0% +subset of f inverse of U so what we've + + + align:start position:0% +subset of f inverse of U so what we've +done is we've gone from an open + + align:start position:0% +done is we've gone from an open + + + align:start position:0% +done is we've gone from an open +neighborhood of f of C to an open + + align:start position:0% +neighborhood of f of C to an open + + + align:start position:0% +neighborhood of f of C to an open +neighborhood of C which is what we + + align:start position:0% +neighborhood of C which is what we + + + align:start position:0% +neighborhood of C which is what we +wanted to show right we wanted to show + + align:start position:0% +wanted to show right we wanted to show + + + align:start position:0% +wanted to show right we wanted to show +that F inverse of U Is An Open + + align:start position:0% +that F inverse of U Is An Open + + + align:start position:0% +that F inverse of U Is An Open +neighborhood of + + align:start position:0% +neighborhood of + + + align:start position:0% +neighborhood of +C okay so we now need to prove the other + + align:start position:0% +C okay so we now need to prove the other + + + align:start position:0% +C okay so we now need to prove the other +direction which is sometimes a little + + align:start position:0% +direction which is sometimes a little + + + align:start position:0% +direction which is sometimes a little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +harder to to + + align:start position:0% + + + + align:start position:0% + +do only a little bit harder but should + + align:start position:0% +do only a little bit harder but should + + + align:start position:0% +do only a little bit harder but should +be able to fit right + + align:start position:0% + + + + align:start position:0% + +here okay so now we're going to suppose + + align:start position:0% +here okay so now we're going to suppose + + + align:start position:0% +here okay so now we're going to suppose +that uh let Epsilon be bigger than + + align:start position:0% +that uh let Epsilon be bigger than + + + align:start position:0% +that uh let Epsilon be bigger than +zero and consider the open neighborhood + + align:start position:0% +zero and consider the open neighborhood + + + align:start position:0% +zero and consider the open neighborhood +of f of C given by the + + align:start position:0% +of f of C given by the + + + align:start position:0% +of f of C given by the +ball and consider + + align:start position:0% + + + + align:start position:0% + +the ball of radius Epsilon around F of + + align:start position:0% + + + + align:start position:0% + +C then we know by + + align:start position:0% +C then we know by + + + align:start position:0% +C then we know by +assumption that F inverse of this ball + + align:start position:0% +assumption that F inverse of this ball + + + align:start position:0% +assumption that F inverse of this ball +of radius Epsilon of f of + + align:start position:0% +of radius Epsilon of f of + + + align:start position:0% +of radius Epsilon of f of +C uh 1 2 3 is an + + align:start position:0% +C uh 1 2 3 is an + + + align:start position:0% +C uh 1 2 3 is an +open + + align:start position:0% +open + + + align:start position:0% +open +neighborhood of + + align:start position:0% +neighborhood of + + + align:start position:0% +neighborhood of +C but because this is an open set around + + align:start position:0% +C but because this is an open set around + + + align:start position:0% +C but because this is an open set around +C + + align:start position:0% +C + + + align:start position:0% +C +there exists a Delta bigger than zero + + align:start position:0% +there exists a Delta bigger than zero + + + align:start position:0% +there exists a Delta bigger than zero +such + + align:start position:0% +such + + + align:start position:0% +such +that the ball of radius Delta around C + + align:start position:0% +that the ball of radius Delta around C + + + align:start position:0% +that the ball of radius Delta around C +is contained in F inverse of the ball of + + align:start position:0% +is contained in F inverse of the ball of + + + align:start position:0% +is contained in F inverse of the ball of +radius Epsilon of f of + + align:start position:0% + + + + align:start position:0% + +C right because this is an open set and + + align:start position:0% +C right because this is an open set and + + + align:start position:0% +C right because this is an open set and +we know that therefore that we know that + + align:start position:0% +we know that therefore that we know that + + + align:start position:0% +we know that therefore that we know that +there exists a radius such that the ball + + align:start position:0% +there exists a radius such that the ball + + + align:start position:0% +there exists a radius such that the ball +of radius Delta of that radius is + + align:start position:0% +of radius Delta of that radius is + + + align:start position:0% +of radius Delta of that radius is +contained in the open set and then we're + + align:start position:0% +contained in the open set and then we're + + + align:start position:0% +contained in the open set and then we're +done right because then we can apply F + + align:start position:0% +done right because then we can apply F + + + align:start position:0% +done right because then we can apply F +to both sides and we that F of the ball + + align:start position:0% +to both sides and we that F of the ball + + + align:start position:0% +to both sides and we that F of the ball +of radius Delta around C is contained in + + align:start position:0% +of radius Delta around C is contained in + + + align:start position:0% +of radius Delta around C is contained in +the ball of radius Epsilon of f c which + + align:start position:0% +the ball of radius Epsilon of f c which + + + align:start position:0% +the ball of radius Epsilon of f c which +is exactly the statement of continuity + + align:start position:0% +is exactly the statement of continuity + + + align:start position:0% +is exactly the statement of continuity +you can just write this out in terms of + + align:start position:0% +you can just write this out in terms of + + + align:start position:0% +you can just write this out in terms of +the metric right because then the + + align:start position:0% +the metric right because then the + + + align:start position:0% +the metric right because then the +distance from X to C being less than + + align:start position:0% +distance from X to C being less than + + + align:start position:0% +distance from X to C being less than +Delta implies that the distance from F + + align:start position:0% +Delta implies that the distance from F + + + align:start position:0% +Delta implies that the distance from F +ofx to F of C is less than Epsilon so + + align:start position:0% +ofx to F of C is less than Epsilon so + + + align:start position:0% +ofx to F of C is less than Epsilon so +this concludes the proof okay this was + + align:start position:0% +this concludes the proof okay this was + + + align:start position:0% +this concludes the proof okay this was +the general theory of metric space we've + + align:start position:0% +the general theory of metric space we've + + + align:start position:0% +the general theory of metric space we've +talked about convergent sequences which + + align:start position:0% +talked about convergent sequences which + + + align:start position:0% +talked about convergent sequences which +was essentially just like the real + + align:start position:0% +was essentially just like the real + + + align:start position:0% +was essentially just like the real +numbers we talked about uh open sets + + align:start position:0% +numbers we talked about uh open sets + + + align:start position:0% +numbers we talked about uh open sets +specifically the topological properties + + align:start position:0% +specifically the topological properties + + + align:start position:0% +specifically the topological properties +of them um which is important for + + align:start position:0% +of them um which is important for + + + align:start position:0% +of them um which is important for +topology and then we related those two + + align:start position:0% +topology and then we related those two + + + align:start position:0% +topology and then we related those two +concepts to convergent uh to continuity + + align:start position:0% +concepts to convergent uh to continuity + + + align:start position:0% +concepts to convergent uh to continuity +right we talked about how continuity is + + align:start position:0% +right we talked about how continuity is + + + align:start position:0% +right we talked about how continuity is +sequentially continuous at a point C if + + align:start position:0% +sequentially continuous at a point C if + + + align:start position:0% +sequentially continuous at a point C if +it's continuous on the metric space and + + align:start position:0% +it's continuous on the metric space and + + + align:start position:0% +it's continuous on the metric space and +we've talked about how continuity can be + + align:start position:0% +we've talked about how continuity can be + + + align:start position:0% +we've talked about how continuity can be +defined in terms of these open sets this + + align:start position:0% +defined in terms of these open sets this + + + align:start position:0% +defined in terms of these open sets this +is by no means a simple connection it + + align:start position:0% +is by no means a simple connection it + + + align:start position:0% +is by no means a simple connection it +can take a while to feel comfortable + + align:start position:0% +can take a while to feel comfortable + + + align:start position:0% +can take a while to feel comfortable +with these ideas but I highly suggest if + + align:start position:0% +with these ideas but I highly suggest if + + + align:start position:0% +with these ideas but I highly suggest if +if you're finding this a little bit + + align:start position:0% +if you're finding this a little bit + + + align:start position:0% +if you're finding this a little bit +confusing to try and draw out the + + align:start position:0% +confusing to try and draw out the + + + align:start position:0% +confusing to try and draw out the +pictures why does why does this + + align:start position:0% +pictures why does why does this + + + align:start position:0% +pictures why does why does this +conclusion hold why can I apply F to + + align:start position:0% +conclusion hold why can I apply F to + + + align:start position:0% +conclusion hold why can I apply F to +both sides and have things to be fine + + align:start position:0% +both sides and have things to be fine + + + align:start position:0% +both sides and have things to be fine +it's just a practice and set theory but + + align:start position:0% +it's just a practice and set theory but + + + align:start position:0% +it's just a practice and set theory but +it is helpful to do at some point okay + + align:start position:0% +it is helpful to do at some point okay + + + align:start position:0% +it is helpful to do at some point okay +starting next time we're going to start + + align:start position:0% +starting next time we're going to start + + + align:start position:0% +starting next time we're going to start +talking about something you might not + + align:start position:0% +talking about something you might not + + + align:start position:0% +talking about something you might not +have seen before at all known as compact + + align:start position:0% +have seen before at all known as compact + + + align:start position:0% +have seen before at all known as compact +sets until then have a great weekend + + align:start position:0% +sets until then have a great weekend + + + align:start position:0% +sets until then have a great weekend +remember that the P set is due on the + + align:start position:0% +remember that the P set is due on the + + + align:start position:0% +remember that the P set is due on the +13th okay all right have a great day \ No newline at end of file diff --git a/uS42vSWEGTU.txt b/uS42vSWEGTU.txt new file mode 100644 index 0000000000000000000000000000000000000000..c3321faab3383c2b6101a81bc44cea882f2e229e --- /dev/null +++ b/uS42vSWEGTU.txt @@ -0,0 +1,6355 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +gonna get started and today we're gonna + + align:start position:0% +gonna get started and today we're gonna + + + align:start position:0% +gonna get started and today we're gonna +move forward with the protein + + align:start position:0% +move forward with the protein + + + align:start position:0% +move forward with the protein +degradation module and looking at the + + align:start position:0% +degradation module and looking at the + + + align:start position:0% +degradation module and looking at the +degradation chamber of e.coli clip XP so + + align:start position:0% +degradation chamber of e.coli clip XP so + + + align:start position:0% +degradation chamber of e.coli clip XP so +this is a degradation machine and + + align:start position:0% +this is a degradation machine and + + + align:start position:0% +this is a degradation machine and +effectively what we see in this case and + + align:start position:0% +effectively what we see in this case and + + + align:start position:0% +effectively what we see in this case and +as mentioned in lecture last time is + + align:start position:0% +as mentioned in lecture last time is + + + align:start position:0% +as mentioned in lecture last time is +that there are gigantic chambers that + + align:start position:0% +that there are gigantic chambers that + + + align:start position:0% +that there are gigantic chambers that +isolate protease active sites and so + + align:start position:0% +isolate protease active sites and so + + + align:start position:0% +isolate protease active sites and so +we're gonna examine this particular + + align:start position:0% +we're gonna examine this particular + + + align:start position:0% +we're gonna examine this particular +machinery as a paradigm here so the clip + + align:start position:0% +machinery as a paradigm here so the clip + + + align:start position:0% +machinery as a paradigm here so the clip +system was first identified in e.coli + + align:start position:0% +system was first identified in e.coli + + + align:start position:0% +system was first identified in e.coli +and it's highly conserved and what we'll + + align:start position:0% +and it's highly conserved and what we'll + + + align:start position:0% +and it's highly conserved and what we'll +see is that there's encapsulation of an + + align:start position:0% +see is that there's encapsulation of an + + + align:start position:0% +see is that there's encapsulation of an +active site in a large degradation + + align:start position:0% +active site in a large degradation + + + align:start position:0% +active site in a large degradation +chamber so there's two components clip X + + align:start position:0% +chamber so there's two components clip X + + + align:start position:0% +chamber so there's two components clip X +and clip P and so we're going to look at + + align:start position:0% +and clip P and so we're going to look at + + + align:start position:0% +and clip P and so we're going to look at +both of these components individually + + align:start position:0% +both of these components individually + + + align:start position:0% +both of these components individually +and then see how this machine works and + + align:start position:0% +and then see how this machine works and + + + align:start position:0% +and then see how this machine works and +so clip P this is the proteasome okay + + align:start position:0% +so clip P this is the proteasome okay + + + align:start position:0% +so clip P this is the proteasome okay +and it's a serine protease so we talked + + align:start position:0% +and it's a serine protease so we talked + + + align:start position:0% +and it's a serine protease so we talked +about serine proteases last time so + + align:start position:0% +about serine proteases last time so + + + align:start position:0% +about serine proteases last time so +there's the catalytic triad of serine + + align:start position:0% +there's the catalytic triad of serine + + + align:start position:0% +there's the catalytic triad of serine +histidine an aspartate + + align:start position:0% +histidine an aspartate + + + align:start position:0% +histidine an aspartate +so there's formation of a covalent a + + align:start position:0% +so there's formation of a covalent a + + + align:start position:0% +so there's formation of a covalent a +selenium intermediate we learned that + + align:start position:0% +selenium intermediate we learned that + + + align:start position:0% +selenium intermediate we learned that +the serine residue is the active site + + align:start position:0% +the serine residue is the active site + + + align:start position:0% +the serine residue is the active site +nucleophile and what we're going to see + + align:start position:0% +nucleophile and what we're going to see + + + align:start position:0% +nucleophile and what we're going to see +is that this degradation chamber has 14 + + align:start position:0% +is that this degradation chamber has 14 + + + align:start position:0% +is that this degradation chamber has 14 +active sites + + align:start position:0% + + + + align:start position:0% + +okay and what this does is degrade + + align:start position:0% + + + + align:start position:0% + +proteins into short polypeptides so it's + + align:start position:0% +proteins into short polypeptides so it's + + + align:start position:0% +proteins into short polypeptides so it's +a peptides of about seven to eight amino + + align:start position:0% +a peptides of about seven to eight amino + + + align:start position:0% +a peptides of about seven to eight amino +acids and so if we consider a cartoon of + + align:start position:0% +acids and so if we consider a cartoon of + + + align:start position:0% +acids and so if we consider a cartoon of +the structure what we find is that we + + align:start position:0% +the structure what we find is that we + + + align:start position:0% +the structure what we find is that we +have two back-to-back rings here okay + + align:start position:0% +have two back-to-back rings here okay + + + align:start position:0% +have two back-to-back rings here okay +and each of these rings is a seven or + + align:start position:0% +and each of these rings is a seven or + + + align:start position:0% +and each of these rings is a seven or +seven murmur so we have two hep tumors + + align:start position:0% + + + + align:start position:0% + +okay in terms of size approximately 90 + + align:start position:0% +okay in terms of size approximately 90 + + + align:start position:0% +okay in terms of size approximately 90 +angstroms here and approximately 90 + + align:start position:0% +angstroms here and approximately 90 + + + align:start position:0% +angstroms here and approximately 90 +angstroms across okay and then this + + align:start position:0% +angstroms across okay and then this + + + align:start position:0% +angstroms across okay and then this +region between the two rings is + + align:start position:0% +region between the two rings is + + + align:start position:0% +region between the two rings is +sometimes referred to as the equator + + align:start position:0% + + + + align:start position:0% + +okay so here we have two back-to-back + + align:start position:0% +okay so here we have two back-to-back + + + align:start position:0% +okay so here we have two back-to-back +rings okay and these rings generate a + + align:start position:0% +rings okay and these rings generate a + + + align:start position:0% +rings okay and these rings generate a +chamber okay and proteins upwards of + + align:start position:0% +chamber okay and proteins upwards of + + + align:start position:0% +chamber okay and proteins upwards of +about 70 killer Dalton's can fit + + align:start position:0% + + + + align:start position:0% + +and so if we take this looking at from + + align:start position:0% +and so if we take this looking at from + + + align:start position:0% +and so if we take this looking at from +the side and just rotate 90 degrees to + + align:start position:0% +the side and just rotate 90 degrees to + + + align:start position:0% +the side and just rotate 90 degrees to +ask what does it look like from the top + + align:start position:0% +ask what does it look like from the top + + + align:start position:0% +ask what does it look like from the top +okay so this is a side view okay what we + + align:start position:0% +okay so this is a side view okay what we + + + align:start position:0% +okay so this is a side view okay what we +see is that there's a very small pore + + align:start position:0% +see is that there's a very small pore + + + align:start position:0% +see is that there's a very small pore +here okay so we have the seven subunits + + align:start position:0% +here okay so we have the seven subunits + + + align:start position:0% +here okay so we have the seven subunits +and then in the center there's an axial + + align:start position:0% +and then in the center there's an axial + + + align:start position:0% +and then in the center there's an axial +pore okay + + align:start position:0% +pore okay + + + align:start position:0% +pore okay +and this pore is small about 10 + + align:start position:0% +and this pore is small about 10 + + + align:start position:0% +and this pore is small about 10 +angstroms in diameter okay so when + + align:start position:0% +angstroms in diameter okay so when + + + align:start position:0% +angstroms in diameter okay so when +thinking about that size we need to + + align:start position:0% +thinking about that size we need to + + + align:start position:0% +thinking about that size we need to +think about the size of some large + + align:start position:0% +think about the size of some large + + + align:start position:0% +think about the size of some large +protein right if we have something on + + align:start position:0% +protein right if we have something on + + + align:start position:0% +protein right if we have something on +the order of 70 kilo daltons + + align:start position:0% +the order of 70 kilo daltons + + + align:start position:0% +the order of 70 kilo daltons +with a fold that proteins not going to + + align:start position:0% +with a fold that proteins not going to + + + align:start position:0% +with a fold that proteins not going to +fit through this this hole in that state + + align:start position:0% +fit through this this hole in that state + + + align:start position:0% +fit through this this hole in that state +here okay so it's too small for a big + + align:start position:0% +here okay so it's too small for a big + + + align:start position:0% +here okay so it's too small for a big +folded protein okay but then basically + + align:start position:0% +folded protein okay but then basically + + + align:start position:0% +folded protein okay but then basically +if we take this and rather than just + + align:start position:0% +if we take this and rather than just + + + align:start position:0% +if we take this and rather than just +looking at the top we cut through and + + align:start position:0% +looking at the top we cut through and + + + align:start position:0% +looking at the top we cut through and +ask what's going on in the interior what + + align:start position:0% +ask what's going on in the interior what + + + align:start position:0% +ask what's going on in the interior what +do we see okay so cut through + + align:start position:0% + + + + align:start position:0% + +what we see know is that there's a + + align:start position:0% +what we see know is that there's a + + + align:start position:0% +what we see know is that there's a +chamber of about 51 angstroms okay so + + align:start position:0% +chamber of about 51 angstroms okay so + + + align:start position:0% +chamber of about 51 angstroms okay so +this is the interior degradation chamber + + align:start position:0% + + + + align:start position:0% + +okay so one question we're gonna address + + align:start position:0% +okay so one question we're gonna address + + + align:start position:0% +okay so one question we're gonna address +as we move forward is that how is it + + align:start position:0% +as we move forward is that how is it + + + align:start position:0% +as we move forward is that how is it +that a polypeptide gets through this + + align:start position:0% +that a polypeptide gets through this + + + align:start position:0% +that a polypeptide gets through this +hole into the degradation chamber that + + align:start position:0% +hole into the degradation chamber that + + + align:start position:0% +hole into the degradation chamber that +can accommodate you know approaching up + + align:start position:0% +can accommodate you know approaching up + + + align:start position:0% +can accommodate you know approaching up +to 70 kilonewtons + + align:start position:0% +to 70 kilonewtons + + + align:start position:0% +to 70 kilonewtons +okay so small axial pour versus large + + align:start position:0% +okay so small axial pour versus large + + + align:start position:0% +okay so small axial pour versus large +degradation chamber here okay + + align:start position:0% +degradation chamber here okay + + + align:start position:0% +degradation chamber here okay +so we'll look at some structures of clip + + align:start position:0% +so we'll look at some structures of clip + + + align:start position:0% +so we'll look at some structures of clip +P and then go on to clip X so what we're + + align:start position:0% +P and then go on to clip X so what we're + + + align:start position:0% +P and then go on to clip X so what we're +looking at here are effectively what + + align:start position:0% +looking at here are effectively what + + + align:start position:0% +looking at here are effectively what +I've drawn out in cartoon form on the + + align:start position:0% +I've drawn out in cartoon form on the + + + align:start position:0% +I've drawn out in cartoon form on the +board so here we have the side view of + + align:start position:0% +board so here we have the side view of + + + align:start position:0% +board so here we have the side view of +clip P we have the top ring the bottom + + align:start position:0% +clip P we have the top ring the bottom + + + align:start position:0% +clip P we have the top ring the bottom +ring and here's the region between the + + align:start position:0% +ring and here's the region between the + + + align:start position:0% +ring and here's the region between the +two the equator if we look at the top + + align:start position:0% +two the equator if we look at the top + + + align:start position:0% +two the equator if we look at the top +here they're describing the axial pore + + align:start position:0% +here they're describing the axial pore + + + align:start position:0% +here they're describing the axial pore +as a portal okay and here's the cutaway + + align:start position:0% +as a portal okay and here's the cutaway + + + align:start position:0% +as a portal okay and here's the cutaway +view so this hole is very small and if + + align:start position:0% +view so this hole is very small and if + + + align:start position:0% +view so this hole is very small and if +we look at the cutaway view what we see + + align:start position:0% +we look at the cutaway view what we see + + + align:start position:0% +we look at the cutaway view what we see +is the degradation chamber here okay and + + align:start position:0% +is the degradation chamber here okay and + + + align:start position:0% +is the degradation chamber here okay and +basically the seven different serine + + align:start position:0% +basically the seven different serine + + + align:start position:0% +basically the seven different serine +protease active sites are shown here + + align:start position:0% +protease active sites are shown here + + + align:start position:0% +protease active sites are shown here +okay and this is a side view cutting + + align:start position:0% +okay and this is a side view cutting + + + align:start position:0% +okay and this is a side view cutting +through through the middle here so we + + align:start position:0% +through through the middle here so we + + + align:start position:0% +through through the middle here so we +see that these Syrian protease active + + align:start position:0% +see that these Syrian protease active + + + align:start position:0% +see that these Syrian protease active +sites are down in this region here if we + + align:start position:0% +sites are down in this region here if we + + + align:start position:0% +sites are down in this region here if we +take another view and look at again this + + align:start position:0% +take another view and look at again this + + + align:start position:0% +take another view and look at again this +is cut away so cut through the side view + + align:start position:0% +is cut away so cut through the side view + + + align:start position:0% +is cut away so cut through the side view +what we can look at here is the + + align:start position:0% +what we can look at here is the + + + align:start position:0% +what we can look at here is the +machinery in the active site so we + + align:start position:0% +machinery in the active site so we + + + align:start position:0% +machinery in the active site so we +learned last time about the catalytic + + align:start position:0% +learned last time about the catalytic + + + align:start position:0% +learned last time about the catalytic +triad with the aspartate histidine and + + align:start position:0% +triad with the aspartate histidine and + + + align:start position:0% +triad with the aspartate histidine and +serine and in this particular structure + + align:start position:0% +serine and in this particular structure + + + align:start position:0% +serine and in this particular structure +there's a serine protease inhibitor + + align:start position:0% +there's a serine protease inhibitor + + + align:start position:0% +there's a serine protease inhibitor +bound to the Syrian side chain here okay + + align:start position:0% +bound to the Syrian side chain here okay + + + align:start position:0% +bound to the Syrian side chain here okay +so that that conserved machinery + + align:start position:0% +so that that conserved machinery + + + align:start position:0% +so that that conserved machinery +if we look at the structure of an + + align:start position:0% +if we look at the structure of an + + + align:start position:0% +if we look at the structure of an +individual clip piece subunit those are + + align:start position:0% +individual clip piece subunit those are + + + align:start position:0% +individual clip piece subunit those are +shown here from several different + + align:start position:0% +shown here from several different + + + align:start position:0% +shown here from several different +organisms what we see if we can think + + align:start position:0% +organisms what we see if we can think + + + align:start position:0% +organisms what we see if we can think +about this is the top part and this is + + align:start position:0% +about this is the top part and this is + + + align:start position:0% +about this is the top part and this is +the bottom part of one ring we see + + align:start position:0% +the bottom part of one ring we see + + + align:start position:0% +the bottom part of one ring we see +there's a region with axial loops + + align:start position:0% +there's a region with axial loops + + + align:start position:0% +there's a region with axial loops +there's a head domain and what's called + + align:start position:0% +there's a head domain and what's called + + + align:start position:0% +there's a head domain and what's called +a handle region okay and the catalytic + + align:start position:0% +a handle region okay and the catalytic + + + align:start position:0% +a handle region okay and the catalytic +triad is located at the juncture of the + + align:start position:0% +triad is located at the juncture of the + + + align:start position:0% +triad is located at the juncture of the +head and handle region and you can again + + align:start position:0% +head and handle region and you can again + + + align:start position:0% +head and handle region and you can again +look back to the cutaway views to orient + + align:start position:0% +look back to the cutaway views to orient + + + align:start position:0% +look back to the cutaway views to orient +that within the whole chamber + + align:start position:0% +that within the whole chamber + + + align:start position:0% +that within the whole chamber +okay these axial loops we'll see are + + align:start position:0% +okay these axial loops we'll see are + + + align:start position:0% +okay these axial loops we'll see are +important for interaction with clip X + + align:start position:0% +important for interaction with clip X + + + align:start position:0% +important for interaction with clip X +and we'll talk about that component of + + align:start position:0% +and we'll talk about that component of + + + align:start position:0% +and we'll talk about that component of +the machine in a moment here again just + + align:start position:0% +the machine in a moment here again just + + + align:start position:0% +the machine in a moment here again just +structures of clip P from various + + align:start position:0% +structures of clip P from various + + + align:start position:0% +structures of clip P from various +organisms ecoli streptococcus human we + + align:start position:0% +organisms ecoli streptococcus human we + + + align:start position:0% +organisms ecoli streptococcus human we +see that that they're all very similar + + align:start position:0% +see that that they're all very similar + + + align:start position:0% +see that that they're all very similar +here so what is clip X moving forward + + align:start position:0% + + + + align:start position:0% + +okay so clip X is effectively an + + align:start position:0% +okay so clip X is effectively an + + + align:start position:0% +okay so clip X is effectively an +accessory protein okay and in some + + align:start position:0% +accessory protein okay and in some + + + align:start position:0% +accessory protein okay and in some +respects we can think about it as a lid + + align:start position:0% +respects we can think about it as a lid + + + align:start position:0% +respects we can think about it as a lid +to the proteasome okay it's a hexamer + + align:start position:0% + + + + align:start position:0% + +okay so there's a mismatch here in terms + + align:start position:0% +okay so there's a mismatch here in terms + + + align:start position:0% +okay so there's a mismatch here in terms +of the number of subunits and clip P and + + align:start position:0% +of the number of subunits and clip P and + + + align:start position:0% +of the number of subunits and clip P and +clip X this is different from what we + + align:start position:0% +clip X this is different from what we + + + align:start position:0% +clip X this is different from what we +saw with grow al grow es where they are + + align:start position:0% +saw with grow al grow es where they are + + + align:start position:0% +saw with grow al grow es where they are +both heptamer + + align:start position:0% +both heptamer + + + align:start position:0% +both heptamer +clip clip X is a hexamer and it's an AAA + + align:start position:0% +clip clip X is a hexamer and it's an AAA + + + align:start position:0% +clip clip X is a hexamer and it's an AAA +so Triple A plus unfold ace okay + + align:start position:0% +so Triple A plus unfold ace okay + + + align:start position:0% +so Triple A plus unfold ace okay +it's an ATPase here okay and effectively + + align:start position:0% +it's an ATPase here okay and effectively + + + align:start position:0% +it's an ATPase here okay and effectively +what we'll see is that clip X has an + + align:start position:0% +what we'll see is that clip X has an + + + align:start position:0% +what we'll see is that clip X has an +important role as an accessory protein + + align:start position:0% +important role as an accessory protein + + + align:start position:0% +important role as an accessory protein +that unfolds the polypeptide that's + + align:start position:0% +that unfolds the polypeptide that's + + + align:start position:0% +that unfolds the polypeptide that's +destined for degradation by clip P + + align:start position:0% + + + + align:start position:0% + +so when unfolds the polypeptide and + + align:start position:0% +so when unfolds the polypeptide and + + + align:start position:0% +so when unfolds the polypeptide and +we're gonna have to ask how as we go + + align:start position:0% +we're gonna have to ask how as we go + + + align:start position:0% +we're gonna have to ask how as we go +through okay and in addition to + + align:start position:0% +through okay and in addition to + + + align:start position:0% +through okay and in addition to +unfolding it also threads that + + align:start position:0% +unfolding it also threads that + + + align:start position:0% +unfolding it also threads that +polypeptide that's being unfolded and + + align:start position:0% +polypeptide that's being unfolded and + + + align:start position:0% +polypeptide that's being unfolded and +through the axial pore such that it can + + align:start position:0% +through the axial pore such that it can + + + align:start position:0% +through the axial pore such that it can +reach the degradation chamber okay and + + align:start position:0% +reach the degradation chamber okay and + + + align:start position:0% +reach the degradation chamber okay and +threads into the degradation chamber and + + align:start position:0% +threads into the degradation chamber and + + + align:start position:0% +threads into the degradation chamber and +so if we look at clip X from a top view + + align:start position:0% + + + + align:start position:0% + +and I'm agin we have a hole + + align:start position:0% + + + + align:start position:0% + +and we have a six Merc okay here so if + + align:start position:0% +and we have a six Merc okay here so if + + + align:start position:0% +and we have a six Merc okay here so if +we take a look in this particular + + align:start position:0% +we take a look in this particular + + + align:start position:0% +we take a look in this particular +depiction what we're seeing are the top + + align:start position:0% +depiction what we're seeing are the top + + + align:start position:0% +depiction what we're seeing are the top +views and the side views so here we have + + align:start position:0% +views and the side views so here we have + + + align:start position:0% +views and the side views so here we have +put P here we have clip X and what we + + align:start position:0% +put P here we have clip X and what we + + + align:start position:0% +put P here we have clip X and what we +want to ask is how is it that clip X + + align:start position:0% +want to ask is how is it that clip X + + + align:start position:0% +want to ask is how is it that clip X +binds to clip P and how is this mismatch + + align:start position:0% +binds to clip P and how is this mismatch + + + align:start position:0% +binds to clip P and how is this mismatch +in terms of the number of subunits + + align:start position:0% +in terms of the number of subunits + + + align:start position:0% +in terms of the number of subunits +accommodated right so it's not that one + + align:start position:0% +accommodated right so it's not that one + + + align:start position:0% +accommodated right so it's not that one +subunit is precisely going to act with + + align:start position:0% +subunit is precisely going to act with + + + align:start position:0% +subunit is precisely going to act with +one because we have six in throughout + + align:start position:0% +one because we have six in throughout + + + align:start position:0% +one because we have six in throughout +because we have six in clip X and 7 and + + align:start position:0% +because we have six in clip X and 7 and + + + align:start position:0% +because we have six in clip X and 7 and +clip P and so if we think about how clip + + align:start position:0% +clip P and so if we think about how clip + + + align:start position:0% +clip P and so if we think about how clip +explains to clip P what we see is that + + align:start position:0% +explains to clip P what we see is that + + + align:start position:0% +explains to clip P what we see is that +we have the six mer so we're looking + + align:start position:0% +we have the six mer so we're looking + + + align:start position:0% +we have the six mer so we're looking +from the side view okay and there's some + + align:start position:0% +from the side view okay and there's some + + + align:start position:0% +from the side view okay and there's some +loops that are called IGF loops okay so + + align:start position:0% +loops that are called IGF loops okay so + + + align:start position:0% +loops that are called IGF loops okay so +these are tripeptide motifs and they're + + align:start position:0% +these are tripeptide motifs and they're + + + align:start position:0% +these are tripeptide motifs and they're +flexible okay and these loops interact + + align:start position:0% +flexible okay and these loops interact + + + align:start position:0% +flexible okay and these loops interact +with hydrophobic regions of clip P + + align:start position:0% + + + + align:start position:0% + +and this flexibility helps accommodate + + align:start position:0% +and this flexibility helps accommodate + + + align:start position:0% +and this flexibility helps accommodate +the 6 vs 7 sub units so if we look here + + align:start position:0% +the 6 vs 7 sub units so if we look here + + + align:start position:0% +the 6 vs 7 sub units so if we look here +here we see these tripeptide loops okay + + align:start position:0% +here we see these tripeptide loops okay + + + align:start position:0% +here we see these tripeptide loops okay +and see we're only seeing three but + + align:start position:0% +and see we're only seeing three but + + + align:start position:0% +and see we're only seeing three but +there's one for subunit so 1 2 3 4 5 6 + + align:start position:0% +there's one for subunit so 1 2 3 4 5 6 + + + align:start position:0% +there's one for subunit so 1 2 3 4 5 6 +here and then what's shown here in red + + align:start position:0% +here and then what's shown here in red + + + align:start position:0% +here and then what's shown here in red +are the hydrophobic regions of clip P + + align:start position:0% +are the hydrophobic regions of clip P + + + align:start position:0% +are the hydrophobic regions of clip P +where these can bind okay and where do + + align:start position:0% +where these can bind okay and where do + + + align:start position:0% +where these can bind okay and where do +we see these regions on clip P here + + align:start position:0% +we see these regions on clip P here + + + align:start position:0% +we see these regions on clip P here +they're a bit removed from the axial + + align:start position:0% +they're a bit removed from the axial + + + align:start position:0% +they're a bit removed from the axial +pore here okay + + align:start position:0% +pore here okay + + + align:start position:0% +pore here okay +so how many of these loops are needed + + align:start position:0% +so how many of these loops are needed + + + align:start position:0% +so how many of these loops are needed +just to note there's been studies done + + align:start position:0% +just to note there's been studies done + + + align:start position:0% +just to note there's been studies done +where these residues are deleted and the + + align:start position:0% +where these residues are deleted and the + + + align:start position:0% +where these residues are deleted and the +question is how many how many of these + + align:start position:0% +question is how many how many of these + + + align:start position:0% +question is how many how many of these +motifs are important for this protein + + align:start position:0% +motifs are important for this protein + + + align:start position:0% +motifs are important for this protein +protein interaction and what's been + + align:start position:0% +protein interaction and what's been + + + align:start position:0% +protein interaction and what's been +found in test-tube studies is that a + + align:start position:0% +found in test-tube studies is that a + + + align:start position:0% +found in test-tube studies is that a +minimum of 2 are required to get + + align:start position:0% +minimum of 2 are required to get + + + align:start position:0% +minimum of 2 are required to get +interaction between clip X and clip clip + + align:start position:0% +interaction between clip X and clip clip + + + align:start position:0% +interaction between clip X and clip clip +P here yeah + + align:start position:0% +P here yeah + + + align:start position:0% +P here yeah +[Music] + + align:start position:0% + + + + align:start position:0% + +um I would presume so but I don't don't + + align:start position:0% +um I would presume so but I don't don't + + + align:start position:0% +um I would presume so but I don't don't +know right so we very much think of this + + align:start position:0% +know right so we very much think of this + + + align:start position:0% +know right so we very much think of this +as coming coming together like as shown + + align:start position:0% +as coming coming together like as shown + + + align:start position:0% +as coming coming together like as shown +here there but don't know jo-ann's you + + align:start position:0% +here there but don't know jo-ann's you + + + align:start position:0% +here there but don't know jo-ann's you +know no I would say it needs to be + + align:start position:0% +know no I would say it needs to be + + + align:start position:0% +know no I would say it needs to be +pretty stable like there's always + + align:start position:0% +pretty stable like there's always + + + align:start position:0% +pretty stable like there's always +dynamics but as we see how this machine + + align:start position:0% +dynamics but as we see how this machine + + + align:start position:0% +dynamics but as we see how this machine +works right + + align:start position:0% +works right + + + align:start position:0% +works right +this whole is going to have to allow the + + align:start position:0% +this whole is going to have to allow the + + + align:start position:0% +this whole is going to have to allow the +polypeptide to thread through and get to + + align:start position:0% +polypeptide to thread through and get to + + + align:start position:0% +polypeptide to thread through and get to +that through that axial pore for the + + align:start position:0% +that through that axial pore for the + + + align:start position:0% +that through that axial pore for the +polypeptide to get in the degradation + + align:start position:0% +polypeptide to get in the degradation + + + align:start position:0% +polypeptide to get in the degradation +chamber so you'd imagine you want that + + align:start position:0% +chamber so you'd imagine you want that + + + align:start position:0% +chamber so you'd imagine you want that +to be lined up quite well in order for + + align:start position:0% +to be lined up quite well in order for + + + align:start position:0% +to be lined up quite well in order for +it to be efficient there okay so what + + align:start position:0% +it to be efficient there okay so what + + + align:start position:0% +it to be efficient there okay so what +are these triple A plus ATP ASE's this + + align:start position:0% +are these triple A plus ATP ASE's this + + + align:start position:0% +are these triple A plus ATP ASE's this +is a very important group of ATP ASE's + + align:start position:0% +is a very important group of ATP ASE's + + + align:start position:0% +is a very important group of ATP ASE's +so what the name means ATP ASE's + + align:start position:0% +so what the name means ATP ASE's + + + align:start position:0% +so what the name means ATP ASE's +associated with various cellular + + align:start position:0% +associated with various cellular + + + align:start position:0% +associated with various cellular +activities and they're super duper given + + align:start position:0% +activities and they're super duper given + + + align:start position:0% +activities and they're super duper given +this hopefully everyone gets a Triple A + + align:start position:0% +this hopefully everyone gets a Triple A + + + align:start position:0% +this hopefully everyone gets a Triple A +plus on the exam tonight the super + + align:start position:0% +plus on the exam tonight the super + + + align:start position:0% +plus on the exam tonight the super +family is involved in many cellular + + align:start position:0% +family is involved in many cellular + + + align:start position:0% +family is involved in many cellular +functions and take a look so many + + align:start position:0% +functions and take a look so many + + + align:start position:0% +functions and take a look so many +diverse functions so membrane fusion + + align:start position:0% +diverse functions so membrane fusion + + + align:start position:0% +diverse functions so membrane fusion +trafficking of vesicles cytoskeleton + + align:start position:0% +trafficking of vesicles cytoskeleton + + + align:start position:0% +trafficking of vesicles cytoskeleton +regulation transport organelle + + align:start position:0% +regulation transport organelle + + + align:start position:0% +regulation transport organelle +biogenesis DNA replication transcription + + align:start position:0% +biogenesis DNA replication transcription + + + align:start position:0% +biogenesis DNA replication transcription +regulation and what we're really + + align:start position:0% +regulation and what we're really + + + align:start position:0% +regulation and what we're really +interested in here is protein + + align:start position:0% +interested in here is protein + + + align:start position:0% +interested in here is protein +degradation so they come up in a variety + + align:start position:0% +degradation so they come up in a variety + + + align:start position:0% +degradation so they come up in a variety +of processes and although these + + align:start position:0% +of processes and although these + + + align:start position:0% +of processes and although these +processes are very different + + align:start position:0% +processes are very different + + + align:start position:0% +processes are very different +all of these triple 8 plus ATP ASE's + + align:start position:0% +all of these triple 8 plus ATP ASE's + + + align:start position:0% +all of these triple 8 plus ATP ASE's +share a common protein architecture and + + align:start position:0% +share a common protein architecture and + + + align:start position:0% +share a common protein architecture and +I'll just point out that there's an ATP + + align:start position:0% +I'll just point out that there's an ATP + + + align:start position:0% +I'll just point out that there's an ATP +binding module and some details are + + align:start position:0% +binding module and some details are + + + align:start position:0% +binding module and some details are +given here in terms of the motif and + + align:start position:0% +given here in terms of the motif and + + + align:start position:0% +given here in terms of the motif and +then really what we'll focus on in terms + + align:start position:0% +then really what we'll focus on in terms + + + align:start position:0% +then really what we'll focus on in terms +of aspects of this course is that they + + align:start position:0% +of aspects of this course is that they + + + align:start position:0% +of aspects of this course is that they +form oligomers that are ring or cylinder + + align:start position:0% +form oligomers that are ring or cylinder + + + align:start position:0% +form oligomers that are ring or cylinder +shaped and they're all hexamers here ok + + align:start position:0% +shaped and they're all hexamers here ok + + + align:start position:0% +shaped and they're all hexamers here ok +and so of importance to clip XP these + + align:start position:0% +and so of importance to clip XP these + + + align:start position:0% +and so of importance to clip XP these +ATP ASE's + + align:start position:0% +ATP ASE's + + + align:start position:0% +ATP ASE's +have the ability to ream + + align:start position:0% +have the ability to ream + + + align:start position:0% +have the ability to ream +conformation of macromolecules and so + + align:start position:0% +conformation of macromolecules and so + + + align:start position:0% +conformation of macromolecules and so +here we're focused on unfolding yeah 80 + + align:start position:0% +here we're focused on unfolding yeah 80 + + + align:start position:0% +here we're focused on unfolding yeah 80 +pieces that aren't associated with other + + align:start position:0% +pieces that aren't associated with other + + + align:start position:0% +pieces that aren't associated with other +activities the architecture strictly + + align:start position:0% +activities the architecture strictly + + + align:start position:0% +activities the architecture strictly +yeah I mean if you look at trna + + align:start position:0% +yeah I mean if you look at trna + + + align:start position:0% +yeah I mean if you look at trna +synthetases right yeah ATPase activity + + align:start position:0% +synthetases right yeah ATPase activity + + + align:start position:0% +synthetases right yeah ATPase activity +100 and Perkins have ATPase activities + + align:start position:0% +100 and Perkins have ATPase activities + + + align:start position:0% +100 and Perkins have ATPase activities +right so they hydrolyze ATP to ADP MPI + + align:start position:0% +right so they hydrolyze ATP to ADP MPI + + + align:start position:0% +right so they hydrolyze ATP to ADP MPI +activities like what water what aren't + + align:start position:0% + + + + align:start position:0% + +well your aminoacyl trna synthetases are + + align:start position:0% +well your aminoacyl trna synthetases are + + + align:start position:0% +well your aminoacyl trna synthetases are +not Triple A plus ATP ASE's what we'll + + align:start position:0% +not Triple A plus ATP ASE's what we'll + + + align:start position:0% +not Triple A plus ATP ASE's what we'll +see in terms of the non-ribosomal + + align:start position:0% +see in terms of the non-ribosomal + + + align:start position:0% +see in terms of the non-ribosomal +peptide synthesis they're not these + + align:start position:0% +peptide synthesis they're not these + + + align:start position:0% +peptide synthesis they're not these +triple e plus ATP ASE's right so these + + align:start position:0% +triple e plus ATP ASE's right so these + + + align:start position:0% +triple e plus ATP ASE's right so these +any yes okay all ATP ASE's the enzymes + + align:start position:0% +any yes okay all ATP ASE's the enzymes + + + align:start position:0% +any yes okay all ATP ASE's the enzymes +in a Cell it's going to have some role + + align:start position:0% +in a Cell it's going to have some role + + + align:start position:0% +in a Cell it's going to have some role +in a cellular activity right so maybe + + align:start position:0% +in a cellular activity right so maybe + + + align:start position:0% +in a cellular activity right so maybe +this name isn't very helpful but what's + + align:start position:0% +this name isn't very helpful but what's + + + align:start position:0% +this name isn't very helpful but what's +common about all of these is that they + + align:start position:0% +common about all of these is that they + + + align:start position:0% +common about all of these is that they +share this common structural motif they + + align:start position:0% +share this common structural motif they + + + align:start position:0% +share this common structural motif they +form these hexamers but within that + + align:start position:0% +form these hexamers but within that + + + align:start position:0% +form these hexamers but within that +there's quite a bit of diversity because + + align:start position:0% +there's quite a bit of diversity because + + + align:start position:0% +there's quite a bit of diversity because +they have all these different functions + + align:start position:0% +they have all these different functions + + + align:start position:0% +they have all these different functions +so we can just see that here to some + + align:start position:0% +so we can just see that here to some + + + align:start position:0% +so we can just see that here to some +degree so he and there's a typo which + + align:start position:0% +degree so he and there's a typo which + + + align:start position:0% +degree so he and there's a typo which +I'll fix before posting but if we take a + + align:start position:0% +I'll fix before posting but if we take a + + + align:start position:0% +I'll fix before posting but if we take a +look just at two examples here of + + align:start position:0% +look just at two examples here of + + + align:start position:0% +look just at two examples here of +different hexameric rings so these are + + align:start position:0% +different hexameric rings so these are + + + align:start position:0% +different hexameric rings so these are +two different Triple A plus ATP ASE's + + align:start position:0% +two different Triple A plus ATP ASE's + + + align:start position:0% +two different Triple A plus ATP ASE's +what do we see so in common they're both + + align:start position:0% +what do we see so in common they're both + + + align:start position:0% +what do we see so in common they're both +hexamers in common they both have an + + align:start position:0% +hexamers in common they both have an + + + align:start position:0% +hexamers in common they both have an +axial pore here but we see different + + align:start position:0% +axial pore here but we see different + + + align:start position:0% +axial pore here but we see different +elements of secondary structure and + + align:start position:0% +elements of secondary structure and + + + align:start position:0% +elements of secondary structure and +granted these are both depicted in a bit + + align:start position:0% +granted these are both depicted in a bit + + + align:start position:0% +granted these are both depicted in a bit +of a different way but if we look here I + + align:start position:0% +of a different way but if we look here I + + + align:start position:0% +of a different way but if we look here I +mean look we have these alpha helical + + align:start position:0% +mean look we have these alpha helical + + + align:start position:0% +mean look we have these alpha helical +regions around the exterior that we + + align:start position:0% +regions around the exterior that we + + + align:start position:0% +regions around the exterior that we +don't see here okay + + align:start position:0% +don't see here okay + + + align:start position:0% +don't see here okay +and in this view I show this particular + + align:start position:0% +and in this view I show this particular + + + align:start position:0% +and in this view I show this particular +one because it's depicted where the ATP + + align:start position:0% +one because it's depicted where the ATP + + + align:start position:0% +one because it's depicted where the ATP +is binding so you can see the ATP + + align:start position:0% +is binding so you can see the ATP + + + align:start position:0% +is binding so you can see the ATP +binding to each subunit here so I've + + align:start position:0% +binding to each subunit here so I've + + + align:start position:0% +binding to each subunit here so I've +shown six ATP's bound so the structural + + align:start position:0% +shown six ATP's bound so the structural + + + align:start position:0% +shown six ATP's bound so the structural +diversity is quite tremendous and here's + + align:start position:0% +diversity is quite tremendous and here's + + + align:start position:0% +diversity is quite tremendous and here's +just another + + align:start position:0% +just another + + + align:start position:0% +just another +example so these are three different + + align:start position:0% +example so these are three different + + + align:start position:0% +example so these are three different +Triple A plus ATP ASE's of the clip + + align:start position:0% +Triple A plus ATP ASE's of the clip + + + align:start position:0% +Triple A plus ATP ASE's of the clip +system so we're going to focus on clip X + + align:start position:0% +system so we're going to focus on clip X + + + align:start position:0% +system so we're going to focus on clip X +but it's not the only one and so what + + align:start position:0% +but it's not the only one and so what + + + align:start position:0% +but it's not the only one and so what +we're looking at here is clip X we have + + align:start position:0% +we're looking at here is clip X we have + + + align:start position:0% +we're looking at here is clip X we have +another family member clip a I'm here + + align:start position:0% +another family member clip a I'm here + + + align:start position:0% +another family member clip a I'm here +clip B okay and so what we see is + + align:start position:0% +clip B okay and so what we see is + + + align:start position:0% +clip B okay and so what we see is +subunit 2 subunit whether it's XA or B + + align:start position:0% +subunit 2 subunit whether it's XA or B + + + align:start position:0% +subunit 2 subunit whether it's XA or B +there's quite a bit of difference right + + align:start position:0% +there's quite a bit of difference right + + + align:start position:0% +there's quite a bit of difference right +so clip X is the most simple in terms of + + align:start position:0% +so clip X is the most simple in terms of + + + align:start position:0% +so clip X is the most simple in terms of +the architecture here for that and so + + align:start position:0% +the architecture here for that and so + + + align:start position:0% +the architecture here for that and so +one thing people think about is in terms + + align:start position:0% +one thing people think about is in terms + + + align:start position:0% +one thing people think about is in terms +of the different activities that have + + align:start position:0% +of the different activities that have + + + align:start position:0% +of the different activities that have +been associated with these different + + align:start position:0% +been associated with these different + + + align:start position:0% +been associated with these different +family members how is it that these + + align:start position:0% +family members how is it that these + + + align:start position:0% +family members how is it that these +different structural features play a + + align:start position:0% +different structural features play a + + + align:start position:0% +different structural features play a +role ok so coming back to clip X and the + + align:start position:0% +role ok so coming back to clip X and the + + + align:start position:0% +role ok so coming back to clip X and the +depiction we saw before right + + align:start position:0% +depiction we saw before right + + + align:start position:0% +depiction we saw before right +clip X is an unfolding and what's really + + align:start position:0% +clip X is an unfolding and what's really + + + align:start position:0% +clip X is an unfolding and what's really +a key point here is that ATP hydrolysis + + align:start position:0% +a key point here is that ATP hydrolysis + + + align:start position:0% +a key point here is that ATP hydrolysis +by clip X is going to power + + align:start position:0% +by clip X is going to power + + + align:start position:0% +by clip X is going to power +conformational changes that allow for + + align:start position:0% +conformational changes that allow for + + + align:start position:0% +conformational changes that allow for +mechanical unfolding of this protein + + align:start position:0% +mechanical unfolding of this protein + + + align:start position:0% +mechanical unfolding of this protein +that's condemned for degradation by clip + + align:start position:0% +that's condemned for degradation by clip + + + align:start position:0% +that's condemned for degradation by clip +P okay and that's what's going to also + + align:start position:0% +P okay and that's what's going to also + + + align:start position:0% +P okay and that's what's going to also +allow for translocation of the resulting + + align:start position:0% +allow for translocation of the resulting + + + align:start position:0% +allow for translocation of the resulting +unfolded protein into the degradation + + align:start position:0% +unfolded protein into the degradation + + + align:start position:0% +unfolded protein into the degradation +chamber so the action of clip X is + + align:start position:0% +chamber so the action of clip X is + + + align:start position:0% +chamber so the action of clip X is +allowing that protein to fit through + + align:start position:0% +allowing that protein to fit through + + + align:start position:0% +allowing that protein to fit through +this axial pore and be threaded into the + + align:start position:0% +this axial pore and be threaded into the + + + align:start position:0% +this axial pore and be threaded into the +chamber here so with that what are the + + align:start position:0% +chamber here so with that what are the + + + align:start position:0% +chamber here so with that what are the +questions we need to address and + + align:start position:0% +questions we need to address and + + + align:start position:0% +questions we need to address and +thinking about how this macro mulish + + align:start position:0% +thinking about how this macro mulish + + + align:start position:0% +thinking about how this macro mulish +molecular machine works one how our + + align:start position:0% +molecular machine works one how our + + + align:start position:0% +molecular machine works one how our +substrates recognized right so there's + + align:start position:0% +substrates recognized right so there's + + + align:start position:0% +substrates recognized right so there's +some certain group of proteins that are + + align:start position:0% +some certain group of proteins that are + + + align:start position:0% +some certain group of proteins that are +going to be degraded by this machinery + + align:start position:0% +going to be degraded by this machinery + + + align:start position:0% +going to be degraded by this machinery +what is the mechanism how is it that + + align:start position:0% +what is the mechanism how is it that + + + align:start position:0% +what is the mechanism how is it that +atp-dependent conformational changes of + + align:start position:0% +atp-dependent conformational changes of + + + align:start position:0% +atp-dependent conformational changes of +clip XP drive unfolding and + + align:start position:0% +clip XP drive unfolding and + + + align:start position:0% +clip XP drive unfolding and +translocation and what is the substrate + + align:start position:0% +translocation and what is the substrate + + + align:start position:0% +translocation and what is the substrate +selectivity so that's where we're going + + align:start position:0% +selectivity so that's where we're going + + + align:start position:0% +selectivity so that's where we're going +to move forward with and so the first + + align:start position:0% +to move forward with and so the first + + + align:start position:0% +to move forward with and so the first +question we need to ask is how are the + + align:start position:0% +question we need to ask is how are the + + + align:start position:0% +question we need to ask is how are the +substrates recognized by clip X + + align:start position:0% +substrates recognized by clip X + + + align:start position:0% +substrates recognized by clip X +okay okay and so what are possibilities + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +first what we'll consider is a + + align:start position:0% +first what we'll consider is a + + + align:start position:0% +first what we'll consider is a +degradation tag okay so when I draw + + align:start position:0% +degradation tag okay so when I draw + + + align:start position:0% +degradation tag okay so when I draw +these cartoons I'm only going to show + + align:start position:0% +these cartoons I'm only going to show + + + align:start position:0% +these cartoons I'm only going to show +one of the two rings for clip P it's not + + align:start position:0% +one of the two rings for clip P it's not + + + align:start position:0% +one of the two rings for clip P it's not +that it's only one this is just for + + align:start position:0% +that it's only one this is just for + + + align:start position:0% +that it's only one this is just for +simplicity but imagine that here we have + + align:start position:0% +simplicity but imagine that here we have + + + align:start position:0% +simplicity but imagine that here we have +X here we have P okay and we have some + + align:start position:0% +X here we have P okay and we have some + + + align:start position:0% +X here we have P okay and we have some +condemned protein which I'll just draw + + align:start position:0% +condemned protein which I'll just draw + + + align:start position:0% +condemned protein which I'll just draw +as a circle so the cell no longer wants + + align:start position:0% +as a circle so the cell no longer wants + + + align:start position:0% +as a circle so the cell no longer wants +this protein it needs to go away okay + + align:start position:0% +this protein it needs to go away okay + + + align:start position:0% +this protein it needs to go away okay +and we can imagine as one possibility is + + align:start position:0% +and we can imagine as one possibility is + + + align:start position:0% +and we can imagine as one possibility is +that a degradation tag can be attached + + align:start position:0% +that a degradation tag can be attached + + + align:start position:0% +that a degradation tag can be attached +to this polypeptide okay and what we + + align:start position:0% +to this polypeptide okay and what we + + + align:start position:0% +to this polypeptide okay and what we +find is that there's a particular tag + + align:start position:0% +find is that there's a particular tag + + + align:start position:0% +find is that there's a particular tag +called SSR a tag that is used to tag + + align:start position:0% +called SSR a tag that is used to tag + + + align:start position:0% +called SSR a tag that is used to tag +proteins for degradation by clip XP so + + align:start position:0% +proteins for degradation by clip XP so + + + align:start position:0% +proteins for degradation by clip XP so +we can think of this tag as a zip code + + align:start position:0% +we can think of this tag as a zip code + + + align:start position:0% +we can think of this tag as a zip code +if a polypeptide gets modified such that + + align:start position:0% +if a polypeptide gets modified such that + + + align:start position:0% +if a polypeptide gets modified such that +this tag is appended it's going to end + + align:start position:0% +this tag is appended it's going to end + + + align:start position:0% +this tag is appended it's going to end +up going to this degradation machine + + align:start position:0% +up going to this degradation machine + + + align:start position:0% +up going to this degradation machine +such that it gets degraded + + align:start position:0% +such that it gets degraded + + + align:start position:0% +such that it gets degraded +okay the tag is 11 amino acids it's + + align:start position:0% +okay the tag is 11 amino acids it's + + + align:start position:0% +okay the tag is 11 amino acids it's +attached to the C terminus + + align:start position:0% + + + + align:start position:0% + +okay and the sequence is a a and d e and + + align:start position:0% +okay and the sequence is a a and d e and + + + align:start position:0% +okay and the sequence is a a and d e and +why a ll laa okay and so what happens in + + align:start position:0% +why a ll laa okay and so what happens in + + + align:start position:0% +why a ll laa okay and so what happens in +this case as shown + + align:start position:0% +this case as shown + + + align:start position:0% +this case as shown +okay we can imagine that this tag binds + + align:start position:0% +okay we can imagine that this tag binds + + + align:start position:0% +okay we can imagine that this tag binds +to the poor of clip X directly and the + + align:start position:0% +to the poor of clip X directly and the + + + align:start position:0% +to the poor of clip X directly and the +tag when binding enables translocation + + align:start position:0% +tag when binding enables translocation + + + align:start position:0% +tag when binding enables translocation +so here + + align:start position:0% + + + + align:start position:0% + +okay and this poor has what are termed + + align:start position:0% +okay and this poor has what are termed + + + align:start position:0% +okay and this poor has what are termed +poor loops that are involved in tag + + align:start position:0% +poor loops that are involved in tag + + + align:start position:0% +poor loops that are involved in tag +binding and in particular there's a + + align:start position:0% +binding and in particular there's a + + + align:start position:0% +binding and in particular there's a +region G Y Z G so for amino acid + + align:start position:0% +region G Y Z G so for amino acid + + + align:start position:0% +region G Y Z G so for amino acid +sequence that is thought to grip and + + align:start position:0% +sequence that is thought to grip and + + + align:start position:0% +sequence that is thought to grip and +drag the substrate okay here and of + + align:start position:0% +drag the substrate okay here and of + + + align:start position:0% +drag the substrate okay here and of +course it's not gripping like we would + + align:start position:0% +course it's not gripping like we would + + + align:start position:0% +course it's not gripping like we would +but there's some interaction there + + align:start position:0% +but there's some interaction there + + + align:start position:0% +but there's some interaction there +happening that allows that to occur so + + align:start position:0% +happening that allows that to occur so + + + align:start position:0% +happening that allows that to occur so +you'll see there's a lot of kind of + + align:start position:0% +you'll see there's a lot of kind of + + + align:start position:0% +you'll see there's a lot of kind of +mechanical type cartoons and language + + align:start position:0% +mechanical type cartoons and language + + + align:start position:0% +mechanical type cartoons and language +used in describing these machines okay + + align:start position:0% +used in describing these machines okay + + + align:start position:0% +used in describing these machines okay +so what is another possibility + + align:start position:0% + + + + align:start position:0% + +okay so another possibility for how an + + align:start position:0% +okay so another possibility for how an + + + align:start position:0% +okay so another possibility for how an +ATPase could interact with a degradation + + align:start position:0% +ATPase could interact with a degradation + + + align:start position:0% +ATPase could interact with a degradation +chamber is that the protein substrate + + align:start position:0% + + + + align:start position:0% + +binds to an extra domain okay + + align:start position:0% +binds to an extra domain okay + + + align:start position:0% +binds to an extra domain okay +attached to the ATPase okay and I point + + align:start position:0% +attached to the ATPase okay and I point + + + align:start position:0% +attached to the ATPase okay and I point +out this possibility is not for clip X + + align:start position:0% +out this possibility is not for clip X + + + align:start position:0% +out this possibility is not for clip X +but it's one to be aware of because it + + align:start position:0% +but it's one to be aware of because it + + + align:start position:0% +but it's one to be aware of because it +can occur okay we saw some of those + + align:start position:0% +can occur okay we saw some of those + + + align:start position:0% +can occur okay we saw some of those +other ATP ASE's are quite complicated so + + align:start position:0% +other ATP ASE's are quite complicated so + + + align:start position:0% +other ATP ASE's are quite complicated so +in this case imagine we have an 80-hour + + align:start position:0% +in this case imagine we have an 80-hour + + + align:start position:0% +in this case imagine we have an 80-hour +ATPase we have the degradation chamber + + align:start position:0% +ATPase we have the degradation chamber + + + align:start position:0% +ATPase we have the degradation chamber +and this ATP a has some extra domain + + align:start position:0% + + + + align:start position:0% + +okay that effectively can bind the + + align:start position:0% +okay that effectively can bind the + + + align:start position:0% +okay that effectively can bind the +condemned protein and help deliver it to + + align:start position:0% +condemned protein and help deliver it to + + + align:start position:0% +condemned protein and help deliver it to +the poor here and just as a third + + align:start position:0% +the poor here and just as a third + + + align:start position:0% +the poor here and just as a third +possibility and something that we'll see + + align:start position:0% +possibility and something that we'll see + + + align:start position:0% +possibility and something that we'll see +moving forward is that there's + + align:start position:0% +moving forward is that there's + + + align:start position:0% +moving forward is that there's +involvement of an adapter protein so in + + align:start position:0% +involvement of an adapter protein so in + + + align:start position:0% +involvement of an adapter protein so in +addition to the ATPase and the + + align:start position:0% +addition to the ATPase and the + + + align:start position:0% +addition to the ATPase and the +degradation chamber there's an adapter + + align:start position:0% +degradation chamber there's an adapter + + + align:start position:0% +degradation chamber there's an adapter +protein that comes into play so in this + + align:start position:0% +protein that comes into play so in this + + + align:start position:0% +protein that comes into play so in this +case the protein + + align:start position:0% + + + + align:start position:0% + +okay adapter okay and this protein helps + + align:start position:0% +okay adapter okay and this protein helps + + + align:start position:0% +okay adapter okay and this protein helps +direct it to the poor so they condemned + + align:start position:0% +direct it to the poor so they condemned + + + align:start position:0% +direct it to the poor so they condemned +protein to the ATPase okay so for + + align:start position:0% +protein to the ATPase okay so for + + + align:start position:0% +protein to the ATPase okay so for +instance here we have the ATPase here we + + align:start position:0% +instance here we have the ATPase here we + + + align:start position:0% +instance here we have the ATPase here we +have the degradation chamber okay and + + align:start position:0% +have the degradation chamber okay and + + + align:start position:0% +have the degradation chamber okay and +maybe there's some additional protein + + align:start position:0% + + + + align:start position:0% + +okay that facilitates getting the + + align:start position:0% +okay that facilitates getting the + + + align:start position:0% +okay that facilitates getting the +condemned protein to the ATPase and so + + align:start position:0% +condemned protein to the ATPase and so + + + align:start position:0% +condemned protein to the ATPase and so +something to keep in mind and what we'll + + align:start position:0% +something to keep in mind and what we'll + + + align:start position:0% +something to keep in mind and what we'll +see with clip XP is that one and three + + align:start position:0% +see with clip XP is that one and three + + + align:start position:0% +see with clip XP is that one and three +are not mutually exclusive okay and + + align:start position:0% +are not mutually exclusive okay and + + + align:start position:0% +are not mutually exclusive okay and +there's an adapter protein named SSP B + + align:start position:0% +there's an adapter protein named SSP B + + + align:start position:0% +there's an adapter protein named SSP B +that can help deliver SSR a tagged + + align:start position:0% +that can help deliver SSR a tagged + + + align:start position:0% +that can help deliver SSR a tagged +polypeptides or proteins to the + + align:start position:0% +polypeptides or proteins to the + + + align:start position:0% +polypeptides or proteins to the +degradation chamber here + + align:start position:0% + + + + align:start position:0% + +so we're gonna think about these SSRI + + align:start position:0% +so we're gonna think about these SSRI + + + align:start position:0% +so we're gonna think about these SSRI +tags quite a bit and something else to + + align:start position:0% +tags quite a bit and something else to + + + align:start position:0% +tags quite a bit and something else to +be aware of is just that these SSRI tags + + align:start position:0% +be aware of is just that these SSRI tags + + + align:start position:0% +be aware of is just that these SSRI tags +are not the only ways of tagging + + align:start position:0% +are not the only ways of tagging + + + align:start position:0% +are not the only ways of tagging +proteins for degradation we're not going + + align:start position:0% +proteins for degradation we're not going + + + align:start position:0% +proteins for degradation we're not going +to talk about it in detail in this + + align:start position:0% +to talk about it in detail in this + + + align:start position:0% +to talk about it in detail in this +course but you should be aware of + + align:start position:0% +course but you should be aware of + + + align:start position:0% +course but you should be aware of +something called the N + rule and this + + align:start position:0% +something called the N + rule and this + + + align:start position:0% +something called the N + rule and this +is really cool so this rule basically + + align:start position:0% +is really cool so this rule basically + + + align:start position:0% +is really cool so this rule basically +states that a half-life of the protein + + align:start position:0% +states that a half-life of the protein + + + align:start position:0% +states that a half-life of the protein +is determined by its n terminal residue + + align:start position:0% +is determined by its n terminal residue + + + align:start position:0% +is determined by its n terminal residue +here and this can be called an undergrad + + align:start position:0% +here and this can be called an undergrad + + + align:start position:0% +here and this can be called an undergrad +and these and a grants are recognized by + + align:start position:0% +and these and a grants are recognized by + + + align:start position:0% +and these and a grants are recognized by +proteins such as clip s and E coli and + + align:start position:0% +proteins such as clip s and E coli and + + + align:start position:0% +proteins such as clip s and E coli and +as a result these proteins can get + + align:start position:0% +as a result these proteins can get + + + align:start position:0% +as a result these proteins can get +delivered to degradation machines so for + + align:start position:0% +delivered to degradation machines so for + + + align:start position:0% +delivered to degradation machines so for +instance they're in addition to clip XP + + align:start position:0% +instance they're in addition to clip XP + + + align:start position:0% +instance they're in addition to clip XP +there's an ATPase clip a that can + + align:start position:0% +there's an ATPase clip a that can + + + align:start position:0% +there's an ATPase clip a that can +associate with clip P and be involved in + + align:start position:0% +associate with clip P and be involved in + + + align:start position:0% +associate with clip P and be involved in +degradation of polypeptides via this and + + align:start position:0% +degradation of polypeptides via this and + + + align:start position:0% +degradation of polypeptides via this and +end rule ok and in terms of the rule + + align:start position:0% +end rule ok and in terms of the rule + + + align:start position:0% +end rule ok and in terms of the rule +depending on the identity of this end + + align:start position:0% +depending on the identity of this end + + + align:start position:0% +depending on the identity of this end +terminal amino acid it may be + + align:start position:0% +terminal amino acid it may be + + + align:start position:0% +terminal amino acid it may be +stabilizing or destabilizing in terms of + + align:start position:0% +stabilizing or destabilizing in terms of + + + align:start position:0% +stabilizing or destabilizing in terms of +protein lifetime if you're curious to + + align:start position:0% +protein lifetime if you're curious to + + + align:start position:0% +protein lifetime if you're curious to +know more about that we can refer you to + + align:start position:0% +know more about that we can refer you to + + + align:start position:0% +know more about that we can refer you to +some literature so here we have a + + align:start position:0% +some literature so here we have a + + + align:start position:0% +some literature so here we have a +cartoon looking at a native protein + + align:start position:0% +cartoon looking at a native protein + + + align:start position:0% +cartoon looking at a native protein +substrate that needs to be degraded it's + + align:start position:0% +substrate that needs to be degraded it's + + + align:start position:0% +substrate that needs to be degraded it's +been modified with a tag we have clip X + + align:start position:0% +been modified with a tag we have clip X + + + align:start position:0% +been modified with a tag we have clip X +here we have clip P okay here's the tag + + align:start position:0% +here we have clip P okay here's the tag + + + align:start position:0% +here we have clip P okay here's the tag +and in addition we can have this adapter + + align:start position:0% +and in addition we can have this adapter + + + align:start position:0% +and in addition we can have this adapter +protein s s P P and the adapter clip s + + align:start position:0% +protein s s P P and the adapter clip s + + + align:start position:0% +protein s s P P and the adapter clip s +so let's think about this tag for a + + align:start position:0% +so let's think about this tag for a + + + align:start position:0% +so let's think about this tag for a +minute and we need to think about this + + align:start position:0% +minute and we need to think about this + + + align:start position:0% +minute and we need to think about this +tag from the standpoint one of in vitro + + align:start position:0% +tag from the standpoint one of in vitro + + + align:start position:0% +tag from the standpoint one of in vitro +experiments because we're going to begin + + align:start position:0% +experiments because we're going to begin + + + align:start position:0% +experiments because we're going to begin +to look at some experiments that were + + align:start position:0% +to look at some experiments that were + + + align:start position:0% +to look at some experiments that were +done to understand how this machine + + align:start position:0% +done to understand how this machine + + + align:start position:0% +done to understand how this machine +works and we also need to think about + + align:start position:0% +works and we also need to think about + + + align:start position:0% +works and we also need to think about +this tag from the standpoint of the cell + + align:start position:0% +this tag from the standpoint of the cell + + + align:start position:0% +this tag from the standpoint of the cell +so if we think about an in vitro + + align:start position:0% +so if we think about an in vitro + + + align:start position:0% +so if we think about an in vitro +experiment where we want to study how + + align:start position:0% +experiment where we want to study how + + + align:start position:0% +experiment where we want to study how +clip XP + + align:start position:0% +clip XP + + + align:start position:0% +clip XP +degrades some protein substrate right we + + align:start position:0% +degrades some protein substrate right we + + + align:start position:0% +degrades some protein substrate right we +can use this SSRI tank and it's quite + + align:start position:0% +can use this SSRI tank and it's quite + + + align:start position:0% +can use this SSRI tank and it's quite +easy to attach 11 amino acids to some + + align:start position:0% +easy to attach 11 amino acids to some + + + align:start position:0% +easy to attach 11 amino acids to some +protein or polypeptide at the c-terminus + + align:start position:0% +protein or polypeptide at the c-terminus + + + align:start position:0% +protein or polypeptide at the c-terminus +right we can do that by protein + + align:start position:0% +right we can do that by protein + + + align:start position:0% +right we can do that by protein +expression we can do that by chemical + + align:start position:0% +expression we can do that by chemical + + + align:start position:0% +expression we can do that by chemical +synthesis here and so we're going to + + align:start position:0% +synthesis here and so we're going to + + + align:start position:0% +synthesis here and so we're going to +look at a number of experiments where + + align:start position:0% +look at a number of experiments where + + + align:start position:0% +look at a number of experiments where +this SSR a tag has been appended to + + align:start position:0% +this SSR a tag has been appended to + + + align:start position:0% +this SSR a tag has been appended to +certain model substrates moving forward + + align:start position:0% +certain model substrates moving forward + + + align:start position:0% +certain model substrates moving forward +so what about in the cell so when is + + align:start position:0% +so what about in the cell so when is + + + align:start position:0% +so what about in the cell so when is +this SSR a tag attached to a protein so + + align:start position:0% +this SSR a tag attached to a protein so + + + align:start position:0% +this SSR a tag attached to a protein so +are all proteins that need to be + + align:start position:0% +are all proteins that need to be + + + align:start position:0% +are all proteins that need to be +degraded destined to clip XP just + + align:start position:0% +degraded destined to clip XP just + + + align:start position:0% +degraded destined to clip XP just +intuitively what do you think yes you + + align:start position:0% +intuitively what do you think yes you + + + align:start position:0% +intuitively what do you think yes you +shaking heads no right there's many many + + align:start position:0% +shaking heads no right there's many many + + + align:start position:0% +shaking heads no right there's many many +proteases around so what proteins are + + align:start position:0% +proteases around so what proteins are + + + align:start position:0% +proteases around so what proteins are +destined for degradation by clip XP + + align:start position:0% +destined for degradation by clip XP + + + align:start position:0% +destined for degradation by clip XP +that's what we're going to look at and + + align:start position:0% +that's what we're going to look at and + + + align:start position:0% +that's what we're going to look at and +how this tag is appended and so + + align:start position:0% +how this tag is appended and so + + + align:start position:0% +how this tag is appended and so +effectively this SSR a tag say an e.coli + + align:start position:0% +effectively this SSR a tag say an e.coli + + + align:start position:0% +effectively this SSR a tag say an e.coli +is used 1 because protein degradation + + align:start position:0% +is used 1 because protein degradation + + + align:start position:0% +is used 1 because protein degradation +needs to be tightly regulated but 2 it's + + align:start position:0% +needs to be tightly regulated but 2 it's + + + align:start position:0% +needs to be tightly regulated but 2 it's +used for dealing with proteins that it + + align:start position:0% +used for dealing with proteins that it + + + align:start position:0% +used for dealing with proteins that it +exhibited stalled translation so this + + align:start position:0% +exhibited stalled translation so this + + + align:start position:0% +exhibited stalled translation so this +discussion is going to bring us back to + + align:start position:0% +discussion is going to bring us back to + + + align:start position:0% +discussion is going to bring us back to +the ribosome here so we want to ask what + + align:start position:0% +the ribosome here so we want to ask what + + + align:start position:0% +the ribosome here so we want to ask what +proteins in the cell are tagged by with + + align:start position:0% +proteins in the cell are tagged by with + + + align:start position:0% +proteins in the cell are tagged by with +SS RA how is the tag attached to the + + align:start position:0% +SS RA how is the tag attached to the + + + align:start position:0% +SS RA how is the tag attached to the +chem protein as well here this is just a + + align:start position:0% +chem protein as well here this is just a + + + align:start position:0% +chem protein as well here this is just a +cartoon showing an adapter protein + + align:start position:0% +cartoon showing an adapter protein + + + align:start position:0% +cartoon showing an adapter protein +helping direct this tag to the substrate + + align:start position:0% +helping direct this tag to the substrate + + + align:start position:0% +helping direct this tag to the substrate +here so we're gonna just move forward to + + align:start position:0% +here so we're gonna just move forward to + + + align:start position:0% +here so we're gonna just move forward to +this slide this tag is specifically + + align:start position:0% +this slide this tag is specifically + + + align:start position:0% +this slide this tag is specifically +added to proteins that are experiencing + + align:start position:0% +added to proteins that are experiencing + + + align:start position:0% +added to proteins that are experiencing +stalled translation so it's estimated + + align:start position:0% +stalled translation so it's estimated + + + align:start position:0% +stalled translation so it's estimated +that on + + align:start position:0% +that on + + + align:start position:0% +that on +order of 0.5% of e.coli translations + + align:start position:0% +order of 0.5% of e.coli translations + + + align:start position:0% +order of 0.5% of e.coli translations +result in SSR a tagging and so this is + + align:start position:0% +result in SSR a tagging and so this is + + + align:start position:0% +result in SSR a tagging and so this is +thought to be one largely of quality + + align:start position:0% +thought to be one largely of quality + + + align:start position:0% +thought to be one largely of quality +control right so you can imagine if the + + align:start position:0% +control right so you can imagine if the + + + align:start position:0% +control right so you can imagine if the +ribosomes stalled there could be buildup + + align:start position:0% +ribosomes stalled there could be buildup + + + align:start position:0% +ribosomes stalled there could be buildup +of polypeptide products that aren't + + align:start position:0% +of polypeptide products that aren't + + + align:start position:0% +of polypeptide products that aren't +wanted and the translation machinery + + align:start position:0% +wanted and the translation machinery + + + align:start position:0% +wanted and the translation machinery +could get blocked and we don't really + + align:start position:0% +could get blocked and we don't really + + + align:start position:0% +could get blocked and we don't really +want that to happen here so here's our + + align:start position:0% +want that to happen here so here's our + + + align:start position:0% +want that to happen here so here's our +friend the ribosome and here's looking + + align:start position:0% +friend the ribosome and here's looking + + + align:start position:0% +friend the ribosome and here's looking +at the 50s ribosomal subunit and we have + + align:start position:0% +at the 50s ribosomal subunit and we have + + + align:start position:0% +at the 50s ribosomal subunit and we have +a polypeptide emerging from that exit + + align:start position:0% +a polypeptide emerging from that exit + + + align:start position:0% +a polypeptide emerging from that exit +tunnel so these should all be familiar + + align:start position:0% +tunnel so these should all be familiar + + + align:start position:0% +tunnel so these should all be familiar +at this stage and so what happens when + + align:start position:0% +at this stage and so what happens when + + + align:start position:0% +at this stage and so what happens when +this ribosome is trying to synthesize a + + align:start position:0% +this ribosome is trying to synthesize a + + + align:start position:0% +this ribosome is trying to synthesize a +polypeptide and it just gets stuck so + + align:start position:0% +polypeptide and it just gets stuck so + + + align:start position:0% +polypeptide and it just gets stuck so +this s sr a tag is attached to the c + + align:start position:0% +this s sr a tag is attached to the c + + + align:start position:0% +this s sr a tag is attached to the c +terminus of proteins and as we're going + + align:start position:0% +terminus of proteins and as we're going + + + align:start position:0% +terminus of proteins and as we're going +to see this occurs Co translationally + + align:start position:0% +to see this occurs Co translationally + + + align:start position:0% +to see this occurs Co translationally +and it's very very interesting machinery + + align:start position:0% +and it's very very interesting machinery + + + align:start position:0% +and it's very very interesting machinery +so what we see here is that there's a + + align:start position:0% +so what we see here is that there's a + + + align:start position:0% +so what we see here is that there's a +new player we haven't yet seen and this + + align:start position:0% +new player we haven't yet seen and this + + + align:start position:0% +new player we haven't yet seen and this +is called SS RA or TM RNA for transfer + + align:start position:0% +is called SS RA or TM RNA for transfer + + + align:start position:0% +is called SS RA or TM RNA for transfer +messenger RNA and it's involved in an + + align:start position:0% +messenger RNA and it's involved in an + + + align:start position:0% +messenger RNA and it's involved in an +attachment of this SS are a tag to + + align:start position:0% +attachment of this SS are a tag to + + + align:start position:0% +attachment of this SS are a tag to +polypeptides that are having stalled + + align:start position:0% +polypeptides that are having stalled + + + align:start position:0% +polypeptides that are having stalled +biosynthesis on the ribosome and so this + + align:start position:0% +biosynthesis on the ribosome and so this + + + align:start position:0% +biosynthesis on the ribosome and so this +player acts as both the tRNA and an mrna + + align:start position:0% +player acts as both the tRNA and an mrna + + + align:start position:0% +player acts as both the tRNA and an mrna +right and we can take a look at the + + align:start position:0% +right and we can take a look at the + + + align:start position:0% +right and we can take a look at the +structures shown here so here we have + + align:start position:0% +structures shown here so here we have + + + align:start position:0% +structures shown here so here we have +tRNA and the cloverleaf depiction I'm + + align:start position:0% +tRNA and the cloverleaf depiction I'm + + + align:start position:0% +tRNA and the cloverleaf depiction I'm +just in awe a tRNA ala and if we take a + + align:start position:0% +just in awe a tRNA ala and if we take a + + + align:start position:0% +just in awe a tRNA ala and if we take a +look here what do we see at this and we + + align:start position:0% +look here what do we see at this and we + + + align:start position:0% +look here what do we see at this and we +have a region of the TM RNA that looks + + align:start position:0% +have a region of the TM RNA that looks + + + align:start position:0% +have a region of the TM RNA that looks +like a tRNA right quite quite similar + + align:start position:0% +like a tRNA right quite quite similar + + + align:start position:0% +like a tRNA right quite quite similar +here to the 3 prime 5 prime end and then + + align:start position:0% +here to the 3 prime 5 prime end and then + + + align:start position:0% +here to the 3 prime 5 prime end and then +we have this additional region and then + + align:start position:0% +we have this additional region and then + + + align:start position:0% +we have this additional region and then +if we look down and here what do we see + + align:start position:0% +if we look down and here what do we see + + + align:start position:0% +if we look down and here what do we see +we see a region that with a little + + align:start position:0% +we see a region that with a little + + + align:start position:0% +we see a region that with a little +imagination we can think looks like mRNA + + align:start position:0% +imagination we can think looks like mRNA + + + align:start position:0% +imagination we can think looks like mRNA +and if we take a look at the various + + align:start position:0% +and if we take a look at the various + + + align:start position:0% +and if we take a look at the various +codons what we + + align:start position:0% +codons what we + + + align:start position:0% +codons what we +see is that the SSR a tag is encoded + + align:start position:0% +see is that the SSR a tag is encoded + + + align:start position:0% +see is that the SSR a tag is encoded +there along with a stop codon so + + align:start position:0% +there along with a stop codon so + + + align:start position:0% +there along with a stop codon so +effectively we have a tRNA look-alike we + + align:start position:0% +effectively we have a tRNA look-alike we + + + align:start position:0% +effectively we have a tRNA look-alike we +have an mRNA look-alike that is encoding + + align:start position:0% +have an mRNA look-alike that is encoding + + + align:start position:0% +have an mRNA look-alike that is encoding +this SSR a tag so what happens there's a + + align:start position:0% +this SSR a tag so what happens there's a + + + align:start position:0% +this SSR a tag so what happens there's a +partner protein called SMP B just to be + + align:start position:0% +partner protein called SMP B just to be + + + align:start position:0% +partner protein called SMP B just to be +aware of and in complex with fmpp it's + + align:start position:0% +aware of and in complex with fmpp it's + + + align:start position:0% +aware of and in complex with fmpp it's +actually ef-tu that delivers this TM RNA + + align:start position:0% +actually ef-tu that delivers this TM RNA + + + align:start position:0% +actually ef-tu that delivers this TM RNA +to the ribosome here so this is pretty + + align:start position:0% +to the ribosome here so this is pretty + + + align:start position:0% +to the ribosome here so this is pretty +interesting just from the standpoint of + + align:start position:0% +interesting just from the standpoint of + + + align:start position:0% +interesting just from the standpoint of +what we know about ef-tu we don't have a + + align:start position:0% +what we know about ef-tu we don't have a + + + align:start position:0% +what we know about ef-tu we don't have a +typical anticodon here so how does that + + align:start position:0% +typical anticodon here so how does that + + + align:start position:0% +typical anticodon here so how does that +happen we're not going to go into + + align:start position:0% +happen we're not going to go into + + + align:start position:0% +happen we're not going to go into +details but it's something you know + + align:start position:0% +details but it's something you know + + + align:start position:0% +details but it's something you know +curiosity should should beg those + + align:start position:0% +curiosity should should beg those + + + align:start position:0% +curiosity should should beg those +questions so what happens we can look at + + align:start position:0% +questions so what happens we can look at + + + align:start position:0% +questions so what happens we can look at +this cartoon overview here and so the + + align:start position:0% +this cartoon overview here and so the + + + align:start position:0% +this cartoon overview here and so the +color coding within this is helpful in + + align:start position:0% +color coding within this is helpful in + + + align:start position:0% +color coding within this is helpful in +terms of keeping track of pieces but + + align:start position:0% +terms of keeping track of pieces but + + + align:start position:0% +terms of keeping track of pieces but +here we start with our stalled ribosomes + + align:start position:0% +here we start with our stalled ribosomes + + + align:start position:0% +here we start with our stalled ribosomes +so the mRNA is found we see there's a + + align:start position:0% +so the mRNA is found we see there's a + + + align:start position:0% +so the mRNA is found we see there's a +peptidyl trna in the piece site you know + + align:start position:0% +peptidyl trna in the piece site you know + + + align:start position:0% +peptidyl trna in the piece site you know +the polypeptide has a number of amino + + align:start position:0% +the polypeptide has a number of amino + + + align:start position:0% +the polypeptide has a number of amino +acids and the a site is empty and for + + align:start position:0% +acids and the a site is empty and for + + + align:start position:0% +acids and the a site is empty and for +some reason no new amino acyl tRNA is + + align:start position:0% +some reason no new amino acyl tRNA is + + + align:start position:0% +some reason no new amino acyl tRNA is +coming in so the ribosomes stealth and + + align:start position:0% +coming in so the ribosomes stealth and + + + align:start position:0% +coming in so the ribosomes stealth and +as a result this SS RA or T mRNA is + + align:start position:0% +as a result this SS RA or T mRNA is + + + align:start position:0% +as a result this SS RA or T mRNA is +recruited to this stalled ribosome and + + align:start position:0% +recruited to this stalled ribosome and + + + align:start position:0% +recruited to this stalled ribosome and +so here we see the tRNA end and yellow + + align:start position:0% +so here we see the tRNA end and yellow + + + align:start position:0% +so here we see the tRNA end and yellow +with the alanine attached and here we + + align:start position:0% +with the alanine attached and here we + + + align:start position:0% +with the alanine attached and here we +have that region + + align:start position:0% +have that region + + + align:start position:0% +have that region +that's mRNA like encoding the tag so + + align:start position:0% +that's mRNA like encoding the tag so + + + align:start position:0% +that's mRNA like encoding the tag so +this molecule biomolecule gets recruited + + align:start position:0% +this molecule biomolecule gets recruited + + + align:start position:0% +this molecule biomolecule gets recruited +and what do we see it enters the a site + + align:start position:0% +and what do we see it enters the a site + + + align:start position:0% +and what do we see it enters the a site +so here we see the tRNA end and the a + + align:start position:0% +so here we see the tRNA end and the a + + + align:start position:0% +so here we see the tRNA end and the a +site and we have the rest of the + + align:start position:0% +site and we have the rest of the + + + align:start position:0% +site and we have the rest of the +molecule here then what there's + + align:start position:0% +molecule here then what there's + + + align:start position:0% +molecule here then what there's +formation of a new peptide bond so we + + align:start position:0% +formation of a new peptide bond so we + + + align:start position:0% +formation of a new peptide bond so we +have peptidyl transfer we see that Alan + + align:start position:0% +have peptidyl transfer we see that Alan + + + align:start position:0% +have peptidyl transfer we see that Alan +is here look that looks quite a bit like + + align:start position:0% +is here look that looks quite a bit like + + + align:start position:0% +is here look that looks quite a bit like +the hybrid states we talked about right + + align:start position:0% +the hybrid states we talked about right + + + align:start position:0% +the hybrid states we talked about right +where we're seeing these and shift into + + align:start position:0% +where we're seeing these and shift into + + + align:start position:0% +where we're seeing these and shift into +the esight not shown in the p-site here + + align:start position:0% +the esight not shown in the p-site here + + + align:start position:0% +the esight not shown in the p-site here +okay and then what happens there's + + align:start position:0% +okay and then what happens there's + + + align:start position:0% +okay and then what happens there's +translocation and there's message + + align:start position:0% +translocation and there's message + + + align:start position:0% +translocation and there's message +switching so the original mRNA gets + + align:start position:0% +switching so the original mRNA gets + + + align:start position:0% +switching so the original mRNA gets +kicked out and what do we see now that + + align:start position:0% +kicked out and what do we see now that + + + align:start position:0% +kicked out and what do we see now that +mRNA like region of the T mRNA is in the + + align:start position:0% +mRNA like region of the T mRNA is in the + + + align:start position:0% +mRNA like region of the T mRNA is in the +a site here then what happens after + + align:start position:0% +a site here then what happens after + + + align:start position:0% +a site here then what happens after +replacement of the mRNA translation can + + align:start position:0% +replacement of the mRNA translation can + + + align:start position:0% +replacement of the mRNA translation can +occur which results in synthesis of the + + align:start position:0% +occur which results in synthesis of the + + + align:start position:0% +occur which results in synthesis of the +SSR a tag so that's how this tag is + + align:start position:0% +SSR a tag so that's how this tag is + + + align:start position:0% +SSR a tag so that's how this tag is +attached to the C terminus of the + + align:start position:0% +attached to the C terminus of the + + + align:start position:0% +attached to the C terminus of the +polypeptide okay an elongation occurs + + align:start position:0% +polypeptide okay an elongation occurs + + + align:start position:0% +polypeptide okay an elongation occurs +until that stop codon in the t mRNA + + align:start position:0% +until that stop codon in the t mRNA + + + align:start position:0% +until that stop codon in the t mRNA +enters the a site okay and then peptide + + align:start position:0% +enters the a site okay and then peptide + + + align:start position:0% +enters the a site okay and then peptide +release occurs here so the result is a + + align:start position:0% +release occurs here so the result is a + + + align:start position:0% +release occurs here so the result is a +protein that has the SSR a tag attached + + align:start position:0% +protein that has the SSR a tag attached + + + align:start position:0% +protein that has the SSR a tag attached +to it C terminus and that protein will + + align:start position:0% +to it C terminus and that protein will + + + align:start position:0% +to it C terminus and that protein will +be directed to clip X P so pretty cool + + align:start position:0% +be directed to clip X P so pretty cool + + + align:start position:0% +be directed to clip X P so pretty cool +yeah thank you so there we don't ever + + align:start position:0% +yeah thank you so there we don't ever + + + align:start position:0% +yeah thank you so there we don't ever +leave the ribosome too much within these + + align:start position:0% +leave the ribosome too much within these + + + align:start position:0% +leave the ribosome too much within these +units here just to point out this tag is + + align:start position:0% +units here just to point out this tag is + + + align:start position:0% +units here just to point out this tag is +universal in bacteria so here's just a + + align:start position:0% +universal in bacteria so here's just a + + + align:start position:0% +universal in bacteria so here's just a +table a phylogenetic distribution you're + + align:start position:0% +table a phylogenetic distribution you're + + + align:start position:0% +table a phylogenetic distribution you're +not responsible for these details yeah + + align:start position:0% + + + + align:start position:0% + +like the original protein completed or + + align:start position:0% +like the original protein completed or + + + align:start position:0% +like the original protein completed or +just yeah so what does the cartoon + + align:start position:0% +just yeah so what does the cartoon + + + align:start position:0% +just yeah so what does the cartoon +suggest it feels like it's already on + + align:start position:0% +suggest it feels like it's already on + + + align:start position:0% +suggest it feels like it's already on +the C end + + align:start position:0% + + + + align:start position:0% + +well the ribosome can stall at various + + align:start position:0% +well the ribosome can stall at various + + + align:start position:0% +well the ribosome can stall at various +points right so imagine you have a + + align:start position:0% +points right so imagine you have a + + + align:start position:0% +points right so imagine you have a +hundred amino acid polypeptide that + + align:start position:0% +hundred amino acid polypeptide that + + + align:start position:0% +hundred amino acid polypeptide that +needs to be synthesized right the + + align:start position:0% +needs to be synthesized right the + + + align:start position:0% +needs to be synthesized right the +ribosome could stall after amino acid + + align:start position:0% +ribosome could stall after amino acid + + + align:start position:0% +ribosome could stall after amino acid +twenty or forty or sixty right it's not + + align:start position:0% +twenty or forty or sixty right it's not + + + align:start position:0% +twenty or forty or sixty right it's not +that the whole polypeptide has been + + align:start position:0% +that the whole polypeptide has been + + + align:start position:0% +that the whole polypeptide has been +synthesized and then this gets put on + + align:start position:0% +synthesized and then this gets put on + + + align:start position:0% +synthesized and then this gets put on +right and maybe some some fragment there + + align:start position:0% +right and maybe some some fragment there + + + align:start position:0% +right and maybe some some fragment there +for that so yes so in terms of this + + align:start position:0% +for that so yes so in terms of this + + + align:start position:0% +for that so yes so in terms of this +adapter protein I just want to make a + + align:start position:0% +adapter protein I just want to make a + + + align:start position:0% +adapter protein I just want to make a +note in terms of the adapter so these + + align:start position:0% +note in terms of the adapter so these + + + align:start position:0% +note in terms of the adapter so these +adapter proteins can help with + + align:start position:0% +adapter proteins can help with + + + align:start position:0% +adapter proteins can help with +regulating the substrate specificity of + + align:start position:0% +regulating the substrate specificity of + + + align:start position:0% +regulating the substrate specificity of +Triple A plus ATP ASE's and effectively + + align:start position:0% +Triple A plus ATP ASE's and effectively + + + align:start position:0% +Triple A plus ATP ASE's and effectively +depending on the system and depending on + + align:start position:0% +depending on the system and depending on + + + align:start position:0% +depending on the system and depending on +the adapter it may enhance or it may + + align:start position:0% +the adapter it may enhance or it may + + + align:start position:0% +the adapter it may enhance or it may +inhibit degradation here so it's a + + align:start position:0% +inhibit degradation here so it's a + + + align:start position:0% +inhibit degradation here so it's a +case-by-case basis this ssp be shown in + + align:start position:0% +case-by-case basis this ssp be shown in + + + align:start position:0% +case-by-case basis this ssp be shown in +the cartoon here is a dimeric adapter + + align:start position:0% +the cartoon here is a dimeric adapter + + + align:start position:0% +the cartoon here is a dimeric adapter +for XP and it promotes degradation of + + align:start position:0% +for XP and it promotes degradation of + + + align:start position:0% +for XP and it promotes degradation of +certain substrates and effectively it + + align:start position:0% +certain substrates and effectively it + + + align:start position:0% +certain substrates and effectively it +enhances recognition of this tag by the + + align:start position:0% +enhances recognition of this tag by the + + + align:start position:0% +enhances recognition of this tag by the +machinery such that the degradation + + align:start position:0% +machinery such that the degradation + + + align:start position:0% +machinery such that the degradation +rates are enhanced so it's not that it's + + align:start position:0% +rates are enhanced so it's not that it's + + + align:start position:0% +rates are enhanced so it's not that it's +required it's just helpful and + + align:start position:0% +required it's just helpful and + + + align:start position:0% +required it's just helpful and +accelerates the process so just + + align:start position:0% + + + + align:start position:0% + +so just an interesting observation + + align:start position:0% +so just an interesting observation + + + align:start position:0% +so just an interesting observation +regarding SSP be it can be Co purified + + align:start position:0% +regarding SSP be it can be Co purified + + + align:start position:0% +regarding SSP be it can be Co purified +with ribosomes here and in terms of its + + align:start position:0% +with ribosomes here and in terms of its + + + align:start position:0% +with ribosomes here and in terms of its +structure and has some resemblance to + + align:start position:0% +structure and has some resemblance to + + + align:start position:0% +structure and has some resemblance to +known RNA binding proteins and this + + align:start position:0% +known RNA binding proteins and this + + + align:start position:0% +known RNA binding proteins and this +resemblance has begged a question you + + align:start position:0% +resemblance has begged a question you + + + align:start position:0% +resemblance has begged a question you +know does SSP be some you know itself um + + align:start position:0% +know does SSP be some you know itself um + + + align:start position:0% +know does SSP be some you know itself um +help with linking protein synthesis and + + align:start position:0% +help with linking protein synthesis and + + + align:start position:0% +help with linking protein synthesis and +protein degradation right so is it + + align:start position:0% +protein degradation right so is it + + + align:start position:0% +protein degradation right so is it +possible that SS PB could help promote + + align:start position:0% +possible that SS PB could help promote + + + align:start position:0% +possible that SS PB could help promote +binding of clip x to polypeptides you + + align:start position:0% +binding of clip x to polypeptides you + + + align:start position:0% +binding of clip x to polypeptides you +know before full release to the ribosome + + align:start position:0% +know before full release to the ribosome + + + align:start position:0% +know before full release to the ribosome +that something people have wondered + + align:start position:0% +that something people have wondered + + + align:start position:0% +that something people have wondered +about and initially this protein was + + align:start position:0% +about and initially this protein was + + + align:start position:0% +about and initially this protein was +classified as stringent of starvation + + align:start position:0% +classified as stringent of starvation + + + align:start position:0% +classified as stringent of starvation +protein that's where the name comes from + + align:start position:0% +protein that's where the name comes from + + + align:start position:0% +protein that's where the name comes from +so if we just take a quick look at its + + align:start position:0% +so if we just take a quick look at its + + + align:start position:0% +so if we just take a quick look at its +structure here what do we see so here's + + align:start position:0% +structure here what do we see so here's + + + align:start position:0% +structure here what do we see so here's +s s PB and then here we have structures + + align:start position:0% +s s PB and then here we have structures + + + align:start position:0% +s s PB and then here we have structures +from ribosomal proteins and so in SS PP + + align:start position:0% +from ribosomal proteins and so in SS PP + + + align:start position:0% +from ribosomal proteins and so in SS PP +clip X binds on this side and + + align:start position:0% +clip X binds on this side and + + + align:start position:0% +clip X binds on this side and +effectively here we look at the + + align:start position:0% +effectively here we look at the + + + align:start position:0% +effectively here we look at the +ribosomal proteins that bind RNA and + + align:start position:0% +ribosomal proteins that bind RNA and + + + align:start position:0% +ribosomal proteins that bind RNA and +they have these RNA binding sites there + + align:start position:0% +they have these RNA binding sites there + + + align:start position:0% +they have these RNA binding sites there +so there's some similarities in terms of + + align:start position:0% +so there's some similarities in terms of + + + align:start position:0% +so there's some similarities in terms of +the alpha helix in terms of the beta + + align:start position:0% +the alpha helix in terms of the beta + + + align:start position:0% +the alpha helix in terms of the beta +sheets here and also I'll just note in + + align:start position:0% +sheets here and also I'll just note in + + + align:start position:0% +sheets here and also I'll just note in +terms of SS PB and the SS are a tag so + + align:start position:0% +terms of SS PB and the SS are a tag so + + + align:start position:0% +terms of SS PB and the SS are a tag so +if we take this tag + + align:start position:0% + + + + align:start position:0% + +so this is our SSR a tag here what's + + align:start position:0% +so this is our SSR a tag here what's + + + align:start position:0% +so this is our SSR a tag here what's +found is that clip X recognition is on + + align:start position:0% +found is that clip X recognition is on + + + align:start position:0% +found is that clip X recognition is on +this end okay an SSP be binding is on + + align:start position:0% +this end okay an SSP be binding is on + + + align:start position:0% +this end okay an SSP be binding is on +this end here so in different points so + + align:start position:0% +this end here so in different points so + + + align:start position:0% +this end here so in different points so +what this indicates here is that SSP b + + align:start position:0% + + + + align:start position:0% + +and clip x can bind simultaneously okay + + align:start position:0% +and clip x can bind simultaneously okay + + + align:start position:0% +and clip x can bind simultaneously okay +but this is small so we can expect that + + align:start position:0% +but this is small so we can expect that + + + align:start position:0% +but this is small so we can expect that +there's some clash here for that okay so + + align:start position:0% +there's some clash here for that okay so + + + align:start position:0% +there's some clash here for that okay so +we're we're going to close it's just + + align:start position:0% +we're we're going to close it's just + + + align:start position:0% +we're we're going to close it's just +looking at an overview as to how this + + align:start position:0% +looking at an overview as to how this + + + align:start position:0% +looking at an overview as to how this +machine works and the model that then + + align:start position:0% +machine works and the model that then + + + align:start position:0% +machine works and the model that then +starting on Friday we'll look at + + align:start position:0% +starting on Friday we'll look at + + + align:start position:0% +starting on Friday we'll look at +experiments that were designed and + + align:start position:0% +experiments that were designed and + + + align:start position:0% +experiments that were designed and +performed to inform this model so if we + + align:start position:0% +performed to inform this model so if we + + + align:start position:0% +performed to inform this model so if we +look at this in one type of cartoon what + + align:start position:0% +look at this in one type of cartoon what + + + align:start position:0% +look at this in one type of cartoon what +are the stages so we can think of three + + align:start position:0% +are the stages so we can think of three + + + align:start position:0% +are the stages so we can think of three +as depicted here where there's some sort + + align:start position:0% +as depicted here where there's some sort + + + align:start position:0% +as depicted here where there's some sort +of initial recognition so the SSR a tag + + align:start position:0% +of initial recognition so the SSR a tag + + + align:start position:0% +of initial recognition so the SSR a tag +of this condemned protein binds to the + + align:start position:0% +of this condemned protein binds to the + + + align:start position:0% +of this condemned protein binds to the +axial pour of clip X and this process + + align:start position:0% +axial pour of clip X and this process + + + align:start position:0% +axial pour of clip X and this process +does not require ATP hydrolysis so here + + align:start position:0% +does not require ATP hydrolysis so here + + + align:start position:0% +does not require ATP hydrolysis so here +we see a folded substrate this dagger on + + align:start position:0% +we see a folded substrate this dagger on + + + align:start position:0% +we see a folded substrate this dagger on +is another word for for one of these + + align:start position:0% +is another word for for one of these + + + align:start position:0% +is another word for for one of these +tags SSR a tag so we see there's some + + align:start position:0% +tags SSR a tag so we see there's some + + + align:start position:0% +tags SSR a tag so we see there's some +recognition here then what happens + + align:start position:0% +recognition here then what happens + + + align:start position:0% +recognition here then what happens +clip X unfolds this substrate so somehow + + align:start position:0% +clip X unfolds this substrate so somehow + + + align:start position:0% +clip X unfolds this substrate so somehow +it has to grip and pull and apply of + + align:start position:0% +it has to grip and pull and apply of + + + align:start position:0% +it has to grip and pull and apply of +force that unfolds the polypeptide and + + align:start position:0% +force that unfolds the polypeptide and + + + align:start position:0% +force that unfolds the polypeptide and +threads that unfolded polypeptide into + + align:start position:0% +threads that unfolded polypeptide into + + + align:start position:0% +threads that unfolded polypeptide into +the degradation chamber so you know kind + + align:start position:0% +the degradation chamber so you know kind + + + align:start position:0% +the degradation chamber so you know kind +of this pulley system is shown here this + + align:start position:0% +of this pulley system is shown here this + + + align:start position:0% +of this pulley system is shown here this +chopper type thing shown here you can + + align:start position:0% +chopper type thing shown here you can + + + align:start position:0% +chopper type thing shown here you can +use your imagination in this unit for + + align:start position:0% +use your imagination in this unit for + + + align:start position:0% +use your imagination in this unit for +how to depict this machine so we see + + align:start position:0% +how to depict this machine so we see + + + align:start position:0% +how to depict this machine so we see +that the polypeptide is being unfolded + + align:start position:0% +that the polypeptide is being unfolded + + + align:start position:0% +that the polypeptide is being unfolded +and threaded through clip X into this + + align:start position:0% +and threaded through clip X into this + + + align:start position:0% +and threaded through clip X into this +chamber where it gets chopped up by the + + align:start position:0% +chamber where it gets chopped up by the + + + align:start position:0% +chamber where it gets chopped up by the +serine protease active sites here okay + + align:start position:0% +serine protease active sites here okay + + + align:start position:0% +serine protease active sites here okay +so for unfolding and translocation ATP + + align:start position:0% +so for unfolding and translocation ATP + + + align:start position:0% +so for unfolding and translocation ATP +is needed + + align:start position:0% +is needed + + + align:start position:0% +is needed +clip X is high drooling I tried + + align:start position:0% +clip X is high drooling I tried + + + align:start position:0% +clip X is high drooling I tried +realizing HTP to allow this to occur + + align:start position:0% +realizing HTP to allow this to occur + + + align:start position:0% +realizing HTP to allow this to occur +okay in the degradation chamber this + + align:start position:0% +okay in the degradation chamber this + + + align:start position:0% +okay in the degradation chamber this +degradation part is independent of ATP + + align:start position:0% +degradation part is independent of ATP + + + align:start position:0% +degradation part is independent of ATP +right the serine protease doesn't need + + align:start position:0% +right the serine protease doesn't need + + + align:start position:0% +right the serine protease doesn't need +that here so how can we kind of break + + align:start position:0% +that here so how can we kind of break + + + align:start position:0% +that here so how can we kind of break +this up further into a model that we can + + align:start position:0% +this up further into a model that we can + + + align:start position:0% +this up further into a model that we can +test what I present here is the working + + align:start position:0% +test what I present here is the working + + + align:start position:0% +test what I present here is the working +model and just note they now the + + align:start position:0% +model and just note they now the + + + align:start position:0% +model and just note they now the +orientation is flipped here so we have + + align:start position:0% +orientation is flipped here so we have + + + align:start position:0% +orientation is flipped here so we have +clip X on the bottom and clip P on top + + align:start position:0% +clip X on the bottom and clip P on top + + + align:start position:0% +clip X on the bottom and clip P on top +so what happens here we can look at this + + align:start position:0% +so what happens here we can look at this + + + align:start position:0% +so what happens here we can look at this +in terms of five steps okay and we can + + align:start position:0% +in terms of five steps okay and we can + + + align:start position:0% +in terms of five steps okay and we can +begin here with binding right so this + + align:start position:0% +begin here with binding right so this + + + align:start position:0% +begin here with binding right so this +SSR a tagged protein needs to bind to + + align:start position:0% +SSR a tagged protein needs to bind to + + + align:start position:0% +SSR a tagged protein needs to bind to +clip X and that binding is associated + + align:start position:0% +clip X and that binding is associated + + + align:start position:0% +clip X and that binding is associated +with some dissociation constant or KD + + align:start position:0% +with some dissociation constant or KD + + + align:start position:0% +with some dissociation constant or KD +here right what do we see after binding + + align:start position:0% +here right what do we see after binding + + + align:start position:0% +here right what do we see after binding +we have a second step which is + + align:start position:0% +we have a second step which is + + + align:start position:0% +we have a second step which is +denaturation so the polypeptide becomes + + align:start position:0% +denaturation so the polypeptide becomes + + + align:start position:0% +denaturation so the polypeptide becomes +unfolded we have a and that's defined by + + align:start position:0% +unfolded we have a and that's defined by + + + align:start position:0% +unfolded we have a and that's defined by +a rate constant for denaturation as + + align:start position:0% +a rate constant for denaturation as + + + align:start position:0% +a rate constant for denaturation as +shown here if we look next we have + + align:start position:0% +shown here if we look next we have + + + align:start position:0% +shown here if we look next we have +translocation so this polypeptide is + + align:start position:0% +translocation so this polypeptide is + + + align:start position:0% +translocation so this polypeptide is +moving through clip X into the + + align:start position:0% +moving through clip X into the + + + align:start position:0% +moving through clip X into the +degradation chamber right and this is + + align:start position:0% +degradation chamber right and this is + + + align:start position:0% +degradation chamber right and this is +also associated with the rate constant + + align:start position:0% +also associated with the rate constant + + + align:start position:0% +also associated with the rate constant +so rate constant for translocation and + + align:start position:0% +so rate constant for translocation and + + + align:start position:0% +so rate constant for translocation and +both of these steps require the use of + + align:start position:0% +both of these steps require the use of + + + align:start position:0% +both of these steps require the use of +ATP once this polypeptide is in the + + align:start position:0% +ATP once this polypeptide is in the + + + align:start position:0% +ATP once this polypeptide is in the +chamber we have step 4 which is + + align:start position:0% +chamber we have step 4 which is + + + align:start position:0% +chamber we have step 4 which is +degradation and again we have K DANC + + align:start position:0% +degradation and again we have K DANC + + + align:start position:0% +degradation and again we have K DANC +this + + align:start position:0% +this + + + align:start position:0% +this +fast and then in this last step here + + align:start position:0% +fast and then in this last step here + + + align:start position:0% +fast and then in this last step here +there's some release so somehow these + + align:start position:0% +there's some release so somehow these + + + align:start position:0% +there's some release so somehow these +poly peptide fragments need to be + + align:start position:0% +poly peptide fragments need to be + + + align:start position:0% +poly peptide fragments need to be +released from the chamber yeah yeah so + + align:start position:0% +released from the chamber yeah yeah so + + + align:start position:0% +released from the chamber yeah yeah so +often the cartoons are drawn just + + align:start position:0% +often the cartoons are drawn just + + + align:start position:0% +often the cartoons are drawn just +showing one of the heptamer but think of + + align:start position:0% +showing one of the heptamer but think of + + + align:start position:0% +showing one of the heptamer but think of +it as a dimer with these two + + align:start position:0% +it as a dimer with these two + + + align:start position:0% +it as a dimer with these two +back-to-back rings here for that right + + align:start position:0% +back-to-back rings here for that right + + + align:start position:0% +back-to-back rings here for that right +so we have five steps here right each + + align:start position:0% +so we have five steps here right each + + + align:start position:0% +so we have five steps here right each +one of these steps has a rate constant + + align:start position:0% +one of these steps has a rate constant + + + align:start position:0% +one of these steps has a rate constant +and one question we want to ask with + + align:start position:0% +and one question we want to ask with + + + align:start position:0% +and one question we want to ask with +this is what is the rate determining + + align:start position:0% +this is what is the rate determining + + + align:start position:0% +this is what is the rate determining +step and the quick answer where we'll + + align:start position:0% +step and the quick answer where we'll + + + align:start position:0% +step and the quick answer where we'll +end today and as indicated in this + + align:start position:0% +end today and as indicated in this + + + align:start position:0% +end today and as indicated in this +overview is that degradation is fast + + align:start position:0% +overview is that degradation is fast + + + align:start position:0% +overview is that degradation is fast +relative to denaturation and + + align:start position:0% +relative to denaturation and + + + align:start position:0% +relative to denaturation and +translocation okay and there should be + + align:start position:0% +translocation okay and there should be + + + align:start position:0% +translocation okay and there should be +an intuitive aspect to that we heard + + align:start position:0% +an intuitive aspect to that we heard + + + align:start position:0% +an intuitive aspect to that we heard +about last time how proteases give these + + align:start position:0% +about last time how proteases give these + + + align:start position:0% +about last time how proteases give these +tremendous rate accelerations right and + + align:start position:0% +tremendous rate accelerations right and + + + align:start position:0% +tremendous rate accelerations right and +if you have an unfolded peptide those + + align:start position:0% +if you have an unfolded peptide those + + + align:start position:0% +if you have an unfolded peptide those +sites where cleavage will happen are + + align:start position:0% +sites where cleavage will happen are + + + align:start position:0% +sites where cleavage will happen are +going to be exposed there so what we're + + align:start position:0% +going to be exposed there so what we're + + + align:start position:0% +going to be exposed there so what we're +going to ask is is it possible to make + + align:start position:0% +going to ask is is it possible to make + + + align:start position:0% +going to ask is is it possible to make +experiments design experience where we + + align:start position:0% +experiments design experience where we + + + align:start position:0% +experiments design experience where we +can separate the denaturation process + + align:start position:0% +can separate the denaturation process + + + align:start position:0% +can separate the denaturation process +from the translocation process and + + align:start position:0% +from the translocation process and + + + align:start position:0% +from the translocation process and +analyze those and in the process of + + align:start position:0% +analyze those and in the process of + + + align:start position:0% +analyze those and in the process of +doing so ask you know what is the ATP + + align:start position:0% +doing so ask you know what is the ATP + + + align:start position:0% +doing so ask you know what is the ATP +utilization for each step and what is + + align:start position:0% +utilization for each step and what is + + + align:start position:0% +utilization for each step and what is +the role for ATP in this process and so + + align:start position:0% +the role for ATP in this process and so + + + align:start position:0% +the role for ATP in this process and so +on Friday we'll begin with discussing + + align:start position:0% +on Friday we'll begin with discussing + + + align:start position:0% +on Friday we'll begin with discussing +substrates the design of substrates that + + align:start position:0% +substrates the design of substrates that + + + align:start position:0% +substrates the design of substrates that +have been used to examine this model in + + align:start position:0% +have been used to examine this model in + + + align:start position:0% +have been used to examine this model in +more detail is there one question next + + align:start position:0% + + + + align:start position:0% + +in the degradation step that's gonna + + align:start position:0% +in the degradation step that's gonna + + + align:start position:0% +in the degradation step that's gonna +depend I mean you can have different + + align:start position:0% +depend I mean you can have different + + + align:start position:0% +depend I mean you can have different +types of bonds with post-translational + + align:start position:0% +types of bonds with post-translational + + + align:start position:0% +types of bonds with post-translational +modifications right right so in the + + align:start position:0% +modifications right right so in the + + + align:start position:0% +modifications right right so in the +periodic system you have a post + + align:start position:0% +periodic system you have a post + + + align:start position:0% +periodic system you have a post +translational modification to direct + + align:start position:0% +translational modification to direct + + + align:start position:0% +translational modification to direct +this condemned protein and that + + align:start position:0% +this condemned protein and that + + + align:start position:0% +this condemned protein and that +machinery so they're ubiquitous and you + + align:start position:0% +machinery so they're ubiquitous and you + + + align:start position:0% +machinery so they're ubiquitous and you +get this poly ubiquitin tail so you saw + + align:start position:0% +get this poly ubiquitin tail so you saw + + + align:start position:0% +get this poly ubiquitin tail so you saw +ubiquitin and recitation number one and + + align:start position:0% +ubiquitin and recitation number one and + + + align:start position:0% +ubiquitin and recitation number one and +the eukaryotic proteasome has the + + align:start position:0% +the eukaryotic proteasome has the + + + align:start position:0% +the eukaryotic proteasome has the +ability to chop those ubiquitin x' off + + align:start position:0% +ability to chop those ubiquitin x' off + + + align:start position:0% +ability to chop those ubiquitin x' off +for recycling they're in that so so + + align:start position:0% +for recycling they're in that so so + + + align:start position:0% +for recycling they're in that so so +that's one example + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/upzI8ZxORyI.txt b/upzI8ZxORyI.txt new file mode 100644 index 0000000000000000000000000000000000000000..d5b72bc2fcfb4e6259460d8974dedf535990506f --- /dev/null +++ b/upzI8ZxORyI.txt @@ -0,0 +1,8699 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common license. Your support + + align:start position:0% +a Creative Common license. Your support + + + align:start position:0% +a Creative Common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mit.edu. + + align:start position:0% + + + + align:start position:0% + +Wireless fantasy by Vladimir Luchevski. + + align:start position:0% +Wireless fantasy by Vladimir Luchevski. + + + align:start position:0% +Wireless fantasy by Vladimir Luchevski. +It's one of the first pieces of + + align:start position:0% +It's one of the first pieces of + + + align:start position:0% +It's one of the first pieces of +computerenerated music. It was done at + + align:start position:0% +computerenerated music. It was done at + + + align:start position:0% +computerenerated music. It was done at +Columbia University in 1960. It was + + align:start position:0% +Columbia University in 1960. It was + + + align:start position:0% +Columbia University in 1960. It was +commissioned by a group of + + align:start position:0% +commissioned by a group of + + + align:start position:0% +commissioned by a group of +uh fans of Lee Deforest and it was uh in + + align:start position:0% +uh fans of Lee Deforest and it was uh in + + + align:start position:0% +uh fans of Lee Deforest and it was uh in +honor of Deforest contribution to + + align:start position:0% +honor of Deforest contribution to + + + align:start position:0% +honor of Deforest contribution to +wireless broadcast. So it it and one of + + align:start position:0% +wireless broadcast. So it it and one of + + + align:start position:0% +wireless broadcast. So it it and one of +the first broadcast Deforest ever sent + + align:start position:0% +the first broadcast Deforest ever sent + + + align:start position:0% +the first broadcast Deforest ever sent +over the radio was the uh piece that + + align:start position:0% +over the radio was the uh piece that + + + align:start position:0% +over the radio was the uh piece that +you're hearing. It's a parcifile. It's + + align:start position:0% +you're hearing. It's a parcifile. It's + + + align:start position:0% +you're hearing. It's a parcifile. It's +from the Vagner opera. And so what + + align:start position:0% +from the Vagner opera. And so what + + + align:start position:0% +from the Vagner opera. And so what +Usachevski has done in the piece is to + + align:start position:0% +Usachevski has done in the piece is to + + + align:start position:0% +Usachevski has done in the piece is to +uh process it to make it sound really + + align:start position:0% +uh process it to make it sound really + + + align:start position:0% +uh process it to make it sound really +distant as though it's coming over a + + align:start position:0% +distant as though it's coming over a + + + align:start position:0% +distant as though it's coming over a +shortwave radio. And then he's got Morse + + align:start position:0% +shortwave radio. And then he's got Morse + + + align:start position:0% +shortwave radio. And then he's got Morse +code and there's various Morse code + + align:start position:0% +code and there's various Morse code + + + align:start position:0% +code and there's various Morse code +messages going through the + + align:start position:0% +messages going through the + + + align:start position:0% +messages going through the +piece. Wireless fantasy from + + align:start position:0% +piece. Wireless fantasy from + + + align:start position:0% +piece. Wireless fantasy from +1960 done longhand by the way. It was + + align:start position:0% +1960 done longhand by the way. It was + + + align:start position:0% +1960 done longhand by the way. It was +really done with Morris code and a + + align:start position:0% +really done with Morris code and a + + + align:start position:0% +really done with Morris code and a +mainframe computer and giant realtore + + align:start position:0% +mainframe computer and giant realtore + + + align:start position:0% +mainframe computer and giant realtore +decks. Nothing like what you have on + + align:start position:0% +decks. Nothing like what you have on + + + align:start position:0% +decks. Nothing like what you have on +your desktop today. Um okay so uh + + align:start position:0% +your desktop today. Um okay so uh + + + align:start position:0% +your desktop today. Um okay so uh +announcements tomorrow will be the + + align:start position:0% +announcements tomorrow will be the + + + align:start position:0% +announcements tomorrow will be the +exceptional Thursday test uh quiz 5 + + align:start position:0% +exceptional Thursday test uh quiz 5 + + + align:start position:0% +exceptional Thursday test uh quiz 5 +based on homework five. Uh last day we + + align:start position:0% +based on homework five. Uh last day we + + + align:start position:0% +based on homework five. Uh last day we +talked about the band theory of solids + + align:start position:0% +talked about the band theory of solids + + + align:start position:0% +talked about the band theory of solids +and in the band theory we were able to + + align:start position:0% +and in the band theory we were able to + + + align:start position:0% +and in the band theory we were able to +distinguish metals from insulators from + + align:start position:0% +distinguish metals from insulators from + + + align:start position:0% +distinguish metals from insulators from +semiconductors. And you can see up here + + align:start position:0% +semiconductors. And you can see up here + + + align:start position:0% +semiconductors. And you can see up here +the metal has u a very very tiny uh + + align:start position:0% +the metal has u a very very tiny uh + + + align:start position:0% +the metal has u a very very tiny uh +energy gap between the the the top of + + align:start position:0% +energy gap between the the the top of + + + align:start position:0% +energy gap between the the the top of +the filled uh orbitals and the bottom of + + align:start position:0% +the filled uh orbitals and the bottom of + + + align:start position:0% +the filled uh orbitals and the bottom of +the unfilled orbitals. So it's + + align:start position:0% +the unfilled orbitals. So it's + + + align:start position:0% +the unfilled orbitals. So it's +effortless to move the electron up into + + align:start position:0% +effortless to move the electron up into + + + align:start position:0% +effortless to move the electron up into +this zone and give it mobility. Uh in an + + align:start position:0% +this zone and give it mobility. Uh in an + + + align:start position:0% +this zone and give it mobility. Uh in an +insulator there's a substantial energy + + align:start position:0% +insulator there's a substantial energy + + + align:start position:0% +insulator there's a substantial energy +required to move from the filled + + align:start position:0% +required to move from the filled + + + align:start position:0% +required to move from the filled +orbitals to the unfilled orbitals which + + align:start position:0% +orbitals to the unfilled orbitals which + + + align:start position:0% +orbitals to the unfilled orbitals which +we neatly refer to as the veilance band + + align:start position:0% +we neatly refer to as the veilance band + + + align:start position:0% +we neatly refer to as the veilance band +uh and conduction band. And arbitrarily + + align:start position:0% +uh and conduction band. And arbitrarily + + + align:start position:0% +uh and conduction band. And arbitrarily +we've chosen three electron volts. + + align:start position:0% +we've chosen three electron volts. + + + align:start position:0% +we've chosen three electron volts. +Typically the insulators are up four, + + align:start position:0% +Typically the insulators are up four, + + + align:start position:0% +Typically the insulators are up four, +five, six and so on electron volts. And + + align:start position:0% +five, six and so on electron volts. And + + + align:start position:0% +five, six and so on electron volts. And +then there's this class of material + + align:start position:0% +then there's this class of material + + + align:start position:0% +then there's this class of material +semiconductors uh for which the band gap + + align:start position:0% +semiconductors uh for which the band gap + + + align:start position:0% +semiconductors uh for which the band gap +is on the order of three electron volts. + + align:start position:0% +is on the order of three electron volts. + + + align:start position:0% +is on the order of three electron volts. +And why is three such a magic number? + + align:start position:0% +And why is three such a magic number? + + + align:start position:0% +And why is three such a magic number? +Because three electron volts is the + + align:start position:0% +Because three electron volts is the + + + align:start position:0% +Because three electron volts is the +threshold of visible light. So materials + + align:start position:0% +threshold of visible light. So materials + + + align:start position:0% +threshold of visible light. So materials +that have energy gaps below three + + align:start position:0% +that have energy gaps below three + + + align:start position:0% +that have energy gaps below three +electron volts will respond to visible + + align:start position:0% +electron volts will respond to visible + + + align:start position:0% +electron volts will respond to visible +light. And uh we're going to talk about + + align:start position:0% +light. And uh we're going to talk about + + + align:start position:0% +light. And uh we're going to talk about +such matters presently. Uh and just the + + align:start position:0% +such matters presently. Uh and just the + + + align:start position:0% +such matters presently. Uh and just the +last point to make is that the veilance + + align:start position:0% +last point to make is that the veilance + + + align:start position:0% +last point to make is that the veilance +band is constructed of the smearing of + + align:start position:0% +band is constructed of the smearing of + + + align:start position:0% +band is constructed of the smearing of +uh or the the splitting of orbitals that + + align:start position:0% +uh or the the splitting of orbitals that + + + align:start position:0% +uh or the the splitting of orbitals that +are associated with bonding. So veence + + align:start position:0% +are associated with bonding. So veence + + + align:start position:0% +are associated with bonding. So veence +band is veence electrons in bonding + + align:start position:0% +band is veence electrons in bonding + + + align:start position:0% +band is veence electrons in bonding +orbitals and the conduction band was + + align:start position:0% +orbitals and the conduction band was + + + align:start position:0% +orbitals and the conduction band was +generated from anti-bonding orbitals. + + align:start position:0% +generated from anti-bonding orbitals. + + + align:start position:0% +generated from anti-bonding orbitals. +And then we looked at + + align:start position:0% +And then we looked at + + + align:start position:0% +And then we looked at +photoexitation. If we have incident + + align:start position:0% +photoexitation. If we have incident + + + align:start position:0% +photoexitation. If we have incident +photons that have enough energy to break + + align:start position:0% +photons that have enough energy to break + + + align:start position:0% +photons that have enough energy to break +the bonds, electrons will be promoted up + + align:start position:0% +the bonds, electrons will be promoted up + + + align:start position:0% +the bonds, electrons will be promoted up +into the conduction band and it's a + + align:start position:0% +into the conduction band and it's a + + + align:start position:0% +into the conduction band and it's a +momentary uh transit and they will + + align:start position:0% +momentary uh transit and they will + + + align:start position:0% +momentary uh transit and they will +subsequently cascade back down and when + + align:start position:0% +subsequently cascade back down and when + + + align:start position:0% +subsequently cascade back down and when +they do so a photon will be remitted. + + align:start position:0% +they do so a photon will be remitted. + + + align:start position:0% +they do so a photon will be remitted. +When the electron cascades down, photon + + align:start position:0% +When the electron cascades down, photon + + + align:start position:0% +When the electron cascades down, photon +will be emitted and the emission will be + + align:start position:0% +will be emitted and the emission will be + + + align:start position:0% +will be emitted and the emission will be +pegged at the band gap energy. So if we + + align:start position:0% +pegged at the band gap energy. So if we + + + align:start position:0% +pegged at the band gap energy. So if we +go into HC over lambda, lambda becomes a + + align:start position:0% +go into HC over lambda, lambda becomes a + + + align:start position:0% +go into HC over lambda, lambda becomes a +a a critical value that's associated + + align:start position:0% +a a critical value that's associated + + + align:start position:0% +a a critical value that's associated +with this particular material. And so we + + align:start position:0% +with this particular material. And so we + + + align:start position:0% +with this particular material. And so we +can plot percent absorption percent + + align:start position:0% +can plot percent absorption percent + + + align:start position:0% +can plot percent absorption percent +absorption of what? Percent absorption + + align:start position:0% +absorption of what? Percent absorption + + + align:start position:0% +absorption of what? Percent absorption +of incident light as a function of the + + align:start position:0% +of incident light as a function of the + + + align:start position:0% +of incident light as a function of the +energy of that incident light. So high + + align:start position:0% +energy of that incident light. So high + + + align:start position:0% +energy of that incident light. So high +wavelength low energy light will pass + + align:start position:0% +wavelength low energy light will pass + + + align:start position:0% +wavelength low energy light will pass +through. It'll be transmitted and the + + align:start position:0% +through. It'll be transmitted and the + + + align:start position:0% +through. It'll be transmitted and the +material will appear transparent. High + + align:start position:0% +material will appear transparent. High + + + align:start position:0% +material will appear transparent. High +energy that is to say low wavelength + + align:start position:0% +energy that is to say low wavelength + + + align:start position:0% +energy that is to say low wavelength +incident radiation will have enough + + align:start position:0% +incident radiation will have enough + + + align:start position:0% +incident radiation will have enough +energy to promote electrons and so + + align:start position:0% +energy to promote electrons and so + + + align:start position:0% +energy to promote electrons and so +therefore those incident photons will be + + align:start position:0% +therefore those incident photons will be + + + align:start position:0% +therefore those incident photons will be +absorbed. the excess energy will be + + align:start position:0% +absorbed. the excess energy will be + + + align:start position:0% +absorbed. the excess energy will be +dissipated up here as heat and then + + align:start position:0% +dissipated up here as heat and then + + + align:start position:0% +dissipated up here as heat and then +we'll get ree of photons and so over + + align:start position:0% +we'll get ree of photons and so over + + + align:start position:0% +we'll get ree of photons and so over +here the material is an absorber and so + + align:start position:0% +here the material is an absorber and so + + + align:start position:0% +here the material is an absorber and so +we have a sharp jump here at uh a + + align:start position:0% +we have a sharp jump here at uh a + + + align:start position:0% +we have a sharp jump here at uh a +critical wavelength which we term the + + align:start position:0% +critical wavelength which we term the + + + align:start position:0% +critical wavelength which we term the +absorption edge and then towards the end + + align:start position:0% +absorption edge and then towards the end + + + align:start position:0% +absorption edge and then towards the end +of the lecture we talked about another + + align:start position:0% +of the lecture we talked about another + + + align:start position:0% +of the lecture we talked about another +type of excitation this was + + align:start position:0% +type of excitation this was + + + align:start position:0% +type of excitation this was +photoexitation we're going to talk about + + align:start position:0% +photoexitation we're going to talk about + + + align:start position:0% +photoexitation we're going to talk about +thermal excitation where the thermal + + align:start position:0% +thermal excitation where the thermal + + + align:start position:0% +thermal excitation where the thermal +energy in the environment is enough to + + align:start position:0% +energy in the environment is enough to + + + align:start position:0% +energy in the environment is enough to +cause the breaking of the bonds and the + + align:start position:0% +cause the breaking of the bonds and the + + + align:start position:0% +cause the breaking of the bonds and the +promotion of the electron gone from the + + align:start position:0% +promotion of the electron gone from the + + + align:start position:0% +promotion of the electron gone from the +veillance band to the conduction band. + + align:start position:0% +veillance band to the conduction band. + + + align:start position:0% +veillance band to the conduction band. +But in this case we discovered that pair + + align:start position:0% +But in this case we discovered that pair + + + align:start position:0% +But in this case we discovered that pair +of carriers was generated not a single + + align:start position:0% +of carriers was generated not a single + + + align:start position:0% +of carriers was generated not a single +carrier. In the case of uh + + align:start position:0% +carrier. In the case of uh + + + align:start position:0% +carrier. In the case of uh +photoexitation the electron moves up + + align:start position:0% +photoexitation the electron moves up + + + align:start position:0% +photoexitation the electron moves up +falls back down. Here we have pair pair + + align:start position:0% +falls back down. Here we have pair pair + + + align:start position:0% +falls back down. Here we have pair pair +excitation. So what happens is this + + align:start position:0% +excitation. So what happens is this + + + align:start position:0% +excitation. So what happens is this +electron is permanently sustainably + + align:start position:0% +electron is permanently sustainably + + + align:start position:0% +electron is permanently sustainably +sitting up in the veence band leaving in + + align:start position:0% +sitting up in the veence band leaving in + + + align:start position:0% +sitting up in the veence band leaving in +its uh place a broken bond which + + align:start position:0% +its uh place a broken bond which + + + align:start position:0% +its uh place a broken bond which +consists of a single electron and a + + align:start position:0% +consists of a single electron and a + + + align:start position:0% +consists of a single electron and a +missing electron which is termed a + + align:start position:0% +missing electron which is termed a + + + align:start position:0% +missing electron which is termed a +whole. It is zero in a land of minus1. + + align:start position:0% +whole. It is zero in a land of minus1. + + + align:start position:0% +whole. It is zero in a land of minus1. +So it appears to be + one and this is + + align:start position:0% +So it appears to be + one and this is + + + align:start position:0% +So it appears to be + one and this is +minus1 in a land of zero. So it appears + + align:start position:0% +minus1 in a land of zero. So it appears + + + align:start position:0% +minus1 in a land of zero. So it appears +to be minus1. So you see you see charge + + align:start position:0% +to be minus1. So you see you see charge + + + align:start position:0% +to be minus1. So you see you see charge +conservation the population of electrons + + align:start position:0% +conservation the population of electrons + + + align:start position:0% +conservation the population of electrons +in the conduction band due to thermal + + align:start position:0% +in the conduction band due to thermal + + + align:start position:0% +in the conduction band due to thermal +excitation is equal to the population of + + align:start position:0% +excitation is equal to the population of + + + align:start position:0% +excitation is equal to the population of +holes in the veilance band and + + align:start position:0% +holes in the veilance band and + + + align:start position:0% +holes in the veilance band and +electrical engineers like to just refer + + align:start position:0% +electrical engineers like to just refer + + + align:start position:0% +electrical engineers like to just refer +to the um the charge the nature of the + + align:start position:0% +to the um the charge the nature of the + + + align:start position:0% +to the um the charge the nature of the +charge regardless of the carrier whether + + align:start position:0% +charge regardless of the carrier whether + + + align:start position:0% +charge regardless of the carrier whether +it's a positive ion or a positive hole + + align:start position:0% +it's a positive ion or a positive hole + + + align:start position:0% +it's a positive ion or a positive hole +as far as they're concerned it's a + + align:start position:0% +as far as they're concerned it's a + + + align:start position:0% +as far as they're concerned it's a +positive so the electrical engineers + + align:start position:0% +positive so the electrical engineers + + + align:start position:0% +positive so the electrical engineers +write this relationship n equals p the + + align:start position:0% +write this relationship n equals p the + + + align:start position:0% +write this relationship n equals p the +number of negative charges in the + + align:start position:0% +number of negative charges in the + + + align:start position:0% +number of negative charges in the +conduction band equals the number of + + align:start position:0% +conduction band equals the number of + + + align:start position:0% +conduction band equals the number of +positive positive charges in the + + align:start position:0% +positive positive charges in the + + + align:start position:0% +positive positive charges in the +veillance band and then I left you with + + align:start position:0% +veillance band and then I left you with + + + align:start position:0% +veillance band and then I left you with +this uh mystery at the end of the + + align:start position:0% +this uh mystery at the end of the + + + align:start position:0% +this uh mystery at the end of the +lecture. I said well we observe thermal + + align:start position:0% +lecture. I said well we observe thermal + + + align:start position:0% +lecture. I said well we observe thermal +excitation in semiconductors but the + + align:start position:0% +excitation in semiconductors but the + + + align:start position:0% +excitation in semiconductors but the +thermal energy is roughly uh related to + + align:start position:0% +thermal energy is roughly uh related to + + + align:start position:0% +thermal energy is roughly uh related to +the product of the boltzman constant + + align:start position:0% +the product of the boltzman constant + + + align:start position:0% +the product of the boltzman constant +times the temperature and in electron + + align:start position:0% +times the temperature and in electron + + + align:start position:0% +times the temperature and in electron +volts this amounts to about 140th of an + + align:start position:0% +volts this amounts to about 140th of an + + + align:start position:0% +volts this amounts to about 140th of an +electron volt at room temperature but + + align:start position:0% +electron volt at room temperature but + + + align:start position:0% +electron volt at room temperature but +the band gap energy in semiconductors is + + align:start position:0% +the band gap energy in semiconductors is + + + align:start position:0% +the band gap energy in semiconductors is +on the order of several electron volts + + align:start position:0% +on the order of several electron volts + + + align:start position:0% +on the order of several electron volts +in the case of silicon it's 1.1 electron + + align:start position:0% +in the case of silicon it's 1.1 electron + + + align:start position:0% +in the case of silicon it's 1.1 electron +volts so how can we justify any kind of + + align:start position:0% +volts so how can we justify any kind of + + + align:start position:0% +volts so how can we justify any kind of +thermal excitation given that the + + align:start position:0% +thermal excitation given that the + + + align:start position:0% +thermal excitation given that the +thermal energy is so much lower than + + align:start position:0% +thermal energy is so much lower than + + + align:start position:0% +thermal energy is so much lower than +that of the band gap energy. Well, I + + align:start position:0% +that of the band gap energy. Well, I + + + align:start position:0% +that of the band gap energy. Well, I +have good news. The answer is that the + + align:start position:0% +have good news. The answer is that the + + + align:start position:0% +have good news. The answer is that the +energy in this room is distributed + + align:start position:0% +energy in this room is distributed + + + align:start position:0% +energy in this room is distributed +amongst all of the entities in the room. + + align:start position:0% +amongst all of the entities in the room. + + + align:start position:0% +amongst all of the entities in the room. +So that if you look at the gas for + + align:start position:0% +So that if you look at the gas for + + + align:start position:0% +So that if you look at the gas for +example, let's start, let's go back to + + align:start position:0% +example, let's start, let's go back to + + + align:start position:0% +example, let's start, let's go back to +the 1850s and uh peer into the mind of + + align:start position:0% +the 1850s and uh peer into the mind of + + + align:start position:0% +the 1850s and uh peer into the mind of +uh James Clark Maxwell who also gave us + + align:start position:0% +uh James Clark Maxwell who also gave us + + + align:start position:0% +uh James Clark Maxwell who also gave us +Maxwell's equations. He was a polymath + + align:start position:0% +Maxwell's equations. He was a polymath + + + align:start position:0% +Maxwell's equations. He was a polymath +like so many of the other people that + + align:start position:0% +like so many of the other people that + + + align:start position:0% +like so many of the other people that +we've been talking about in 3091. He + + align:start position:0% +we've been talking about in 3091. He + + + align:start position:0% +we've been talking about in 3091. He +didn't just focus on + + align:start position:0% +didn't just focus on + + + align:start position:0% +didn't just focus on +electromagnetism. He was a Renaissance + + align:start position:0% +electromagnetism. He was a Renaissance + + + align:start position:0% +electromagnetism. He was a Renaissance +scholar. And so one of his areas of + + align:start position:0% +scholar. And so one of his areas of + + + align:start position:0% +scholar. And so one of his areas of +interest was physical chemistry. And he + + align:start position:0% +interest was physical chemistry. And he + + + align:start position:0% +interest was physical chemistry. And he +studied gases. And he reasoned that the + + align:start position:0% +studied gases. And he reasoned that the + + + align:start position:0% +studied gases. And he reasoned that the +gases have a distribution of velocities. + + align:start position:0% +gases have a distribution of velocities. + + + align:start position:0% +gases have a distribution of velocities. +All of the gas molecules in this room + + align:start position:0% +All of the gas molecules in this room + + + align:start position:0% +All of the gas molecules in this room +are not behaving as though they are at + + align:start position:0% +are not behaving as though they are at + + + align:start position:0% +are not behaving as though they are at +room temperature. A substantial number + + align:start position:0% +room temperature. A substantial number + + + align:start position:0% +room temperature. A substantial number +are. And that's how we establish + + align:start position:0% +are. And that's how we establish + + + align:start position:0% +are. And that's how we establish +temperature. But what Maxwell reasoned + + align:start position:0% +temperature. But what Maxwell reasoned + + + align:start position:0% +temperature. But what Maxwell reasoned +was that some gas molecules are moving + + align:start position:0% +was that some gas molecules are moving + + + align:start position:0% +was that some gas molecules are moving +around as though the temperature of the + + align:start position:0% +around as though the temperature of the + + + align:start position:0% +around as though the temperature of the +room is 500 Kelvin and some are moving + + align:start position:0% +room is 500 Kelvin and some are moving + + + align:start position:0% +room is 500 Kelvin and some are moving +around as though it's only 100 Kelvin. + + align:start position:0% +around as though it's only 100 Kelvin. + + + align:start position:0% +around as though it's only 100 Kelvin. +But a large number of them are moving + + align:start position:0% +But a large number of them are moving + + + align:start position:0% +But a large number of them are moving +around as though it's roughly 300 + + align:start position:0% +around as though it's roughly 300 + + + align:start position:0% +around as though it's roughly 300 +Kelvin. So he gave us a mathematical + + align:start position:0% +Kelvin. So he gave us a mathematical + + + align:start position:0% +Kelvin. So he gave us a mathematical +formulation of the distribution of + + align:start position:0% +formulation of the distribution of + + + align:start position:0% +formulation of the distribution of +energies. And then about 25 years later, + + align:start position:0% +energies. And then about 25 years later, + + + align:start position:0% +energies. And then about 25 years later, +Boltzman came along and said, you know, + + align:start position:0% +Boltzman came along and said, you know, + + + align:start position:0% +Boltzman came along and said, you know, +I'm going to generalize this idea. I'm + + align:start position:0% +I'm going to generalize this idea. I'm + + + align:start position:0% +I'm going to generalize this idea. I'm +going to generalize the idea. Forget + + align:start position:0% +going to generalize the idea. Forget + + + align:start position:0% +going to generalize the idea. Forget +about just gas molecules and velocity. + + align:start position:0% +about just gas molecules and velocity. + + + align:start position:0% +about just gas molecules and velocity. +Let's talk about all molecules and say + + align:start position:0% +Let's talk about all molecules and say + + + align:start position:0% +Let's talk about all molecules and say +the reason the gas molecules are moving + + align:start position:0% +the reason the gas molecules are moving + + + align:start position:0% +the reason the gas molecules are moving +ma mainly at 300 Kelvin and that some + + align:start position:0% +ma mainly at 300 Kelvin and that some + + + align:start position:0% +ma mainly at 300 Kelvin and that some +are moving at 500 Kelvin is and this was + + align:start position:0% +are moving at 500 Kelvin is and this was + + + align:start position:0% +are moving at 500 Kelvin is and this was +a big leap for Boltzman. He said I'm + + align:start position:0% +a big leap for Boltzman. He said I'm + + + align:start position:0% +a big leap for Boltzman. He said I'm +going to propose that temperature is + + align:start position:0% +going to propose that temperature is + + + align:start position:0% +going to propose that temperature is +distributed as well. That the reason + + align:start position:0% +distributed as well. That the reason + + + align:start position:0% +distributed as well. That the reason +some gas molecules are moving as though + + align:start position:0% +some gas molecules are moving as though + + + align:start position:0% +some gas molecules are moving as though +they have the velocity of 500 Kelvin is + + align:start position:0% +they have the velocity of 500 Kelvin is + + + align:start position:0% +they have the velocity of 500 Kelvin is +that I'm going to propose that they have + + align:start position:0% +that I'm going to propose that they have + + + align:start position:0% +that I'm going to propose that they have +the energy of 500 Kelvin. Well, what is + + align:start position:0% +the energy of 500 Kelvin. Well, what is + + + align:start position:0% +the energy of 500 Kelvin. Well, what is +local energy? That's temperature. So, + + align:start position:0% +local energy? That's temperature. So, + + + align:start position:0% +local energy? That's temperature. So, +Maxwell and Boltzman, we put the two of + + align:start position:0% +Maxwell and Boltzman, we put the two of + + + align:start position:0% +Maxwell and Boltzman, we put the two of +them together and we come up with the + + align:start position:0% +them together and we come up with the + + + align:start position:0% +them together and we come up with the +notion of a distribution of temperature, + + align:start position:0% +notion of a distribution of temperature, + + + align:start position:0% +notion of a distribution of temperature, +a distribution of energy. And this is + + align:start position:0% +a distribution of energy. And this is + + + align:start position:0% +a distribution of energy. And this is +what that distribution looks like. What + + align:start position:0% +what that distribution looks like. What + + + align:start position:0% +what that distribution looks like. What +we do is we plot the number + + align:start position:0% +we do is we plot the number + + + align:start position:0% +we do is we plot the number +of the number of particles in a + + align:start position:0% +of the number of particles in a + + + align:start position:0% +of the number of particles in a +particular ensemble that have a + + align:start position:0% +particular ensemble that have a + + + align:start position:0% +particular ensemble that have a +particular energy as a function of + + align:start position:0% +particular energy as a function of + + + align:start position:0% +particular energy as a function of +energy. And then we'll normalize it over + + align:start position:0% +energy. And then we'll normalize it over + + + align:start position:0% +energy. And then we'll normalize it over +the total number of particles in the + + align:start position:0% +the total number of particles in the + + + align:start position:0% +the total number of particles in the +system. And you know before I do that, + + align:start position:0% +system. And you know before I do that, + + + align:start position:0% +system. And you know before I do that, +why don't I just do an analogy? I'll do + + align:start position:0% +why don't I just do an analogy? I'll do + + + align:start position:0% +why don't I just do an analogy? I'll do +you know we had the we had the test a + + align:start position:0% +you know we had the we had the test a + + + align:start position:0% +you know we had the we had the test a +few weeks ago. Let's do a distribution + + align:start position:0% +few weeks ago. Let's do a distribution + + + align:start position:0% +few weeks ago. Let's do a distribution +of grades and then we'll relate it. + + align:start position:0% +of grades and then we'll relate it. + + + align:start position:0% +of grades and then we'll relate it. +Okay. So for example, what I could do is + + align:start position:0% +Okay. So for example, what I could do is + + + align:start position:0% +Okay. So for example, what I could do is +I could plot grade on this axis and I + + align:start position:0% +I could plot grade on this axis and I + + + align:start position:0% +I could plot grade on this axis and I +could put the number of people who have + + align:start position:0% +could put the number of people who have + + + align:start position:0% +could put the number of people who have +a particular grade and then normalize it + + align:start position:0% +a particular grade and then normalize it + + + align:start position:0% +a particular grade and then normalize it +divide it by the total number of + + align:start position:0% +divide it by the total number of + + + align:start position:0% +divide it by the total number of +students in the class. And if it's a big + + align:start position:0% +students in the class. And if it's a big + + + align:start position:0% +students in the class. And if it's a big +class as this one is and we have some + + align:start position:0% +class as this one is and we have some + + + align:start position:0% +class as this one is and we have some +kind of reasonable test, we expect to + + align:start position:0% +kind of reasonable test, we expect to + + + align:start position:0% +kind of reasonable test, we expect to +see this kind of a distribution, a + + align:start position:0% +see this kind of a distribution, a + + + align:start position:0% +see this kind of a distribution, a +bell-shaped curve, a Gaussian + + align:start position:0% +bell-shaped curve, a Gaussian + + + align:start position:0% +bell-shaped curve, a Gaussian +distribution. All right. And what does + + align:start position:0% +distribution. All right. And what does + + + align:start position:0% +distribution. All right. And what does +this tell? Tell tells us that some + + align:start position:0% +this tell? Tell tells us that some + + + align:start position:0% +this tell? Tell tells us that some +people had greater than the average + + align:start position:0% +people had greater than the average + + + align:start position:0% +people had greater than the average +value, some people had less than the + + align:start position:0% +value, some people had less than the + + + align:start position:0% +value, some people had less than the +average value, but the average value is + + align:start position:0% +average value, but the average value is + + + align:start position:0% +average value, but the average value is +given here. It's a symmetric + + align:start position:0% +given here. It's a symmetric + + + align:start position:0% +given here. It's a symmetric +distribution. And so we call this, we + + align:start position:0% +distribution. And so we call this, we + + + align:start position:0% +distribution. And so we call this, we +can call this the average. This is the + + align:start position:0% +can call this the average. This is the + + + align:start position:0% +can call this the average. This is the +average grade G with a bar over it. and + + align:start position:0% +average grade G with a bar over it. and + + + align:start position:0% +average grade G with a bar over it. and +you get the the inflection point here. + + align:start position:0% +you get the the inflection point here. + + + align:start position:0% +you get the the inflection point here. +This is where the the second derivative + + align:start position:0% +This is where the the second derivative + + + align:start position:0% +This is where the the second derivative +shifts from positive to negative. That's + + align:start position:0% +shifts from positive to negative. That's + + + align:start position:0% +shifts from positive to negative. That's +how you get the standard deviation. This + + align:start position:0% +how you get the standard deviation. This + + + align:start position:0% +how you get the standard deviation. This +is G bar plus standard deviation. This + + align:start position:0% +is G bar plus standard deviation. This + + + align:start position:0% +is G bar plus standard deviation. This +is G bar minus standard deviation. You + + align:start position:0% +is G bar minus standard deviation. You + + + align:start position:0% +is G bar minus standard deviation. You +can have a lot of fun with this. And the + + align:start position:0% +can have a lot of fun with this. And the + + + align:start position:0% +can have a lot of fun with this. And the +area under this line, if I use + + align:start position:0% +area under this line, if I use + + + align:start position:0% +area under this line, if I use +normalized values, the area under this + + align:start position:0% +normalized values, the area under this + + + align:start position:0% +normalized values, the area under this +line must equal one, right? Area equals + + align:start position:0% +line must equal one, right? Area equals + + + align:start position:0% +line must equal one, right? Area equals +1 when I normalize from 0 to infinity. + + align:start position:0% +1 when I normalize from 0 to infinity. + + + align:start position:0% +1 when I normalize from 0 to infinity. +So let's do the same thing here. only + + align:start position:0% +So let's do the same thing here. only + + + align:start position:0% +So let's do the same thing here. only +this is now this is + + align:start position:0% +this is now this is + + + align:start position:0% +this is now this is +Gaussian. This is + + align:start position:0% +Gaussian. This is + + + align:start position:0% +Gaussian. This is +Gaussian. But that's not the way + + align:start position:0% +Gaussian. But that's not the way + + + align:start position:0% +Gaussian. But that's not the way +molecules are distributed or energies + + align:start position:0% +molecules are distributed or energies + + + align:start position:0% +molecules are distributed or energies +are distributed in ensemble. It's + + align:start position:0% +are distributed in ensemble. It's + + + align:start position:0% +are distributed in ensemble. It's +asymmetrical. It looks a little bit like + + align:start position:0% +asymmetrical. It looks a little bit like + + + align:start position:0% +asymmetrical. It looks a little bit like +this. It's got a sharp rise and a long + + align:start position:0% +this. It's got a sharp rise and a long + + + align:start position:0% +this. It's got a sharp rise and a long +asmtoic tail. And so the average is not + + align:start position:0% +asmtoic tail. And so the average is not + + + align:start position:0% +asmtoic tail. And so the average is not +at the maximum in this case. This is + + align:start position:0% +at the maximum in this case. This is + + + align:start position:0% +at the maximum in this case. This is +Maxwell + + align:start position:0% +Maxwell + + + align:start position:0% +Maxwell +Boltzman. This is Maxwell Boltzman. + + align:start position:0% +Boltzman. This is Maxwell Boltzman. + + + align:start position:0% +Boltzman. This is Maxwell Boltzman. +we have a distribution of energies and + + align:start position:0% +we have a distribution of energies and + + + align:start position:0% +we have a distribution of energies and +the average the energy average E with a + + align:start position:0% +the average the energy average E with a + + + align:start position:0% +the average the energy average E with a +til uh a macron over it is somewhere a + + align:start position:0% +til uh a macron over it is somewhere a + + + align:start position:0% +til uh a macron over it is somewhere a +little bit to the right of the maximum + + align:start position:0% +little bit to the right of the maximum + + + align:start position:0% +little bit to the right of the maximum +and so what I'm doing is I'm taking the + + align:start position:0% +and so what I'm doing is I'm taking the + + + align:start position:0% +and so what I'm doing is I'm taking the +energy of a particle the number of + + align:start position:0% +energy of a particle the number of + + + align:start position:0% +energy of a particle the number of +particles that are given energy divided + + align:start position:0% +particles that are given energy divided + + + align:start position:0% +particles that are given energy divided +by the total number of particles so also + + align:start position:0% +by the total number of particles so also + + + align:start position:0% +by the total number of particles so also +the area under this curve must equal one + + align:start position:0% +the area under this curve must equal one + + + align:start position:0% +the area under this curve must equal one +so this is the value at some t1 and what + + align:start position:0% +so this is the value at some t1 and what + + + align:start position:0% +so this is the value at some t1 and what +I want to do is I want to focus down + + align:start position:0% +I want to do is I want to focus down + + + align:start position:0% +I want to do is I want to focus down +here suppose up here this is 1.1 + + align:start position:0% +here suppose up here this is 1.1 + + + align:start position:0% +here suppose up here this is 1.1 +eV 1.1 eV well the average value is here + + align:start position:0% +eV 1.1 eV well the average value is here + + + align:start position:0% +eV 1.1 eV well the average value is here +and I said that this was 140th of an + + align:start position:0% +and I said that this was 140th of an + + + align:start position:0% +and I said that this was 140th of an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +volt that's not the problem that the the + + align:start position:0% +volt that's not the problem that the the + + + align:start position:0% +volt that's not the problem that the the +problem is not that the average is a 140 + + align:start position:0% +problem is not that the average is a 140 + + + align:start position:0% +problem is not that the average is a 140 +of an electron volt the good news is + + align:start position:0% +of an electron volt the good news is + + + align:start position:0% +of an electron volt the good news is +that there is some tiny fraction of the + + align:start position:0% +that there is some tiny fraction of the + + + align:start position:0% +that there is some tiny fraction of the +distribution that has energy above 1.1 + + align:start position:0% +distribution that has energy above 1.1 + + + align:start position:0% +distribution that has energy above 1.1 +eV so if I knew what that fraction was + + align:start position:0% +eV so if I knew what that fraction was + + + align:start position:0% +eV so if I knew what that fraction was +then I could guess how much I could + + align:start position:0% +then I could guess how much I could + + + align:start position:0% +then I could guess how much I could +expect in the way of promotion here. You + + align:start position:0% +expect in the way of promotion here. You + + + align:start position:0% +expect in the way of promotion here. You +can see it's non zero. It's not a sharp + + align:start position:0% +can see it's non zero. It's not a sharp + + + align:start position:0% +can see it's non zero. It's not a sharp +cutoff. There's a tiny there's a tiny uh + + align:start position:0% +cutoff. There's a tiny there's a tiny uh + + + align:start position:0% +cutoff. There's a tiny there's a tiny uh +value out here. And the nature of this + + align:start position:0% +value out here. And the nature of this + + + align:start position:0% +value out here. And the nature of this +curve is that the amount of the the the + + align:start position:0% +curve is that the amount of the the the + + + align:start position:0% +curve is that the amount of the the the +fraction of the distribution out here. + + align:start position:0% +fraction of the distribution out here. + + + align:start position:0% +fraction of the distribution out here. +If I want to integrate say from 1.1 eV + + align:start position:0% +If I want to integrate say from 1.1 eV + + + align:start position:0% +If I want to integrate say from 1.1 eV +out to infinity, that's the area under + + align:start position:0% +out to infinity, that's the area under + + + align:start position:0% +out to infinity, that's the area under +this line. What am I integrating? I'm + + align:start position:0% +this line. What am I integrating? I'm + + + align:start position:0% +this line. What am I integrating? I'm +integrating the the fraction times d. + + align:start position:0% +integrating the the fraction times d. + + + align:start position:0% +integrating the the fraction times d. +This equals e to the minus energy gap + + align:start position:0% +This equals e to the minus energy gap + + + align:start position:0% +This equals e to the minus energy gap +divided by K boltzman temperature. This + + align:start position:0% +divided by K boltzman temperature. This + + + align:start position:0% +divided by K boltzman temperature. This +exponential that's what gives us the + + align:start position:0% +exponential that's what gives us the + + + align:start position:0% +exponential that's what gives us the +fraction underneath this + + align:start position:0% +fraction underneath this + + + align:start position:0% +fraction underneath this +line. Now let's see what happens when + + align:start position:0% +line. Now let's see what happens when + + + align:start position:0% +line. Now let's see what happens when +temperature rises. When temperature + + align:start position:0% +temperature rises. When temperature + + + align:start position:0% +temperature rises. When temperature +rises this line shifts to the right. + + align:start position:0% +rises this line shifts to the right. + + + align:start position:0% +rises this line shifts to the right. +This line shifts to the + + align:start position:0% + + + + align:start position:0% + +right. And as you would expect the + + align:start position:0% +right. And as you would expect the + + + align:start position:0% +right. And as you would expect the +average shifts to the right as well. So + + align:start position:0% +average shifts to the right as well. So + + + align:start position:0% +average shifts to the right as well. So +this now is E average at + + align:start position:0% +this now is E average at + + + align:start position:0% +this now is E average at +T2 and okay let's say I I raise the + + align:start position:0% +T2 and okay let's say I I raise the + + + align:start position:0% +T2 and okay let's say I I raise the +temperature I raise the temperature + + align:start position:0% +temperature I raise the temperature + + + align:start position:0% +temperature I raise the temperature +let's look at silicon so let's say T1 is + + align:start position:0% +let's look at silicon so let's say T1 is + + + align:start position:0% +let's look at silicon so let's say T1 is +equal to room temperature 300 Kelvin and + + align:start position:0% +equal to room temperature 300 Kelvin and + + + align:start position:0% +equal to room temperature 300 Kelvin and +T2 will be the melting point of silicon + + align:start position:0% +T2 will be the melting point of silicon + + + align:start position:0% +T2 will be the melting point of silicon +t2 is the melting point of silicon not + + align:start position:0% +t2 is the melting point of silicon not + + + align:start position:0% +t2 is the melting point of silicon not +to make liquid silicon it's solid + + align:start position:0% +to make liquid silicon it's solid + + + align:start position:0% +to make liquid silicon it's solid +silicon at the melting point so it' be + + align:start position:0% +silicon at the melting point so it' be + + + align:start position:0% +silicon at the melting point so it' be +like ice at 0 degrees C melting point of + + align:start position:0% +like ice at 0 degrees C melting point of + + + align:start position:0% +like ice at 0 degrees C melting point of +silicon is uh 1414° C so add 27 73 to it + + align:start position:0% +silicon is uh 1414° C so add 27 73 to it + + + align:start position:0% +silicon is uh 1414° C so add 27 73 to it +and get about 1,700. It's about + + align:start position:0% +and get about 1,700. It's about + + + align:start position:0% +and get about 1,700. It's about +1,700 Kelvin. So, what's the ratio? T2 + + align:start position:0% +1,700 Kelvin. So, what's the ratio? T2 + + + align:start position:0% +1,700 Kelvin. So, what's the ratio? T2 +to T1 is on the order of about + + align:start position:0% +to T1 is on the order of about + + + align:start position:0% +to T1 is on the order of about +six. So, this thing shifts by a factor + + align:start position:0% +six. So, this thing shifts by a factor + + + align:start position:0% +six. So, this thing shifts by a factor +of six. Let's look at what happens in + + align:start position:0% +of six. Let's look at what happens in + + + align:start position:0% +of six. Let's look at what happens in +here. Let's look at what happens in + + align:start position:0% +here. Let's look at what happens in + + + align:start position:0% +here. Let's look at what happens in +here. So, I'm going to use some some + + align:start position:0% +here. So, I'm going to use some some + + + align:start position:0% +here. So, I'm going to use some some +uh I'm going to blow this up. We'll blow + + align:start position:0% +uh I'm going to blow this up. We'll blow + + + align:start position:0% +uh I'm going to blow this up. We'll blow +this up. So what we're really looking at + + align:start position:0% +this up. So what we're really looking at + + + align:start position:0% +this up. So what we're really looking at +is what's the difference between the + + align:start position:0% +is what's the difference between the + + + align:start position:0% +is what's the difference between the +area here at room temperature and then + + align:start position:0% +area here at room temperature and then + + + align:start position:0% +area here at room temperature and then +what we're going to do is not to scale + + align:start position:0% +what we're going to do is not to scale + + + align:start position:0% +what we're going to do is not to scale +we're going to look at the area under + + align:start position:0% +we're going to look at the area under + + + align:start position:0% +we're going to look at the area under +the green + + align:start position:0% +the green + + + align:start position:0% +the green +curve. And when we use this relationship + + align:start position:0% +curve. And when we use this relationship + + + align:start position:0% +curve. And when we use this relationship +e to the minus energy gap energy over uh + + align:start position:0% +e to the minus energy gap energy over uh + + + align:start position:0% +e to the minus energy gap energy over uh +kt band gap energy over kt we find that + + align:start position:0% +kt band gap energy over kt we find that + + + align:start position:0% +kt band gap energy over kt we find that +the fraction the fraction at + + align:start position:0% +the fraction the fraction at + + + align:start position:0% +the fraction the fraction at +t2 divided by the fraction at t1 comes + + align:start position:0% +t2 divided by the fraction at t1 comes + + + align:start position:0% +t2 divided by the fraction at t1 comes +out to be 10 the 15th. + + align:start position:0% +out to be 10 the 15th. + + + align:start position:0% +out to be 10 the 15th. +So changing temperature changes the + + align:start position:0% +So changing temperature changes the + + + align:start position:0% +So changing temperature changes the +excitation population through the shift + + align:start position:0% +excitation population through the shift + + + align:start position:0% +excitation population through the shift +in the high end of the curve and it's + + align:start position:0% +in the high end of the curve and it's + + + align:start position:0% +in the high end of the curve and it's +only through that that we end up seeing + + align:start position:0% +only through that that we end up seeing + + + align:start position:0% +only through that that we end up seeing +decent levels of population in the + + align:start position:0% +decent levels of population in the + + + align:start position:0% +decent levels of population in the +uh conduction band. + + align:start position:0% +uh conduction band. + + + align:start position:0% +uh conduction band. +But so actually the number the number at + + align:start position:0% +But so actually the number the number at + + + align:start position:0% +But so actually the number the number at +room temperature is vanishingly small at + + align:start position:0% +room temperature is vanishingly small at + + + align:start position:0% +room temperature is vanishingly small at +room temperature. At room temp, at room + + align:start position:0% +room temperature. At room temp, at room + + + align:start position:0% +room temperature. At room temp, at room +temp, the fraction, the fraction in the + + align:start position:0% +temp, the fraction, the fraction in the + + + align:start position:0% +temp, the fraction, the fraction in the +conduction band is about 10 the minus19. + + align:start position:0% +conduction band is about 10 the minus19. + + + align:start position:0% +conduction band is about 10 the minus19. +There's so few of them you can give each + + align:start position:0% +There's so few of them you can give each + + + align:start position:0% +There's so few of them you can give each +of them a name. So there's almost no + + align:start position:0% +of them a name. So there's almost no + + + align:start position:0% +of them a name. So there's almost no +conduction. Silicon at room temperature + + align:start position:0% +conduction. Silicon at room temperature + + + align:start position:0% +conduction. Silicon at room temperature +is an insulator. So if we want to get + + align:start position:0% +is an insulator. So if we want to get + + + align:start position:0% +is an insulator. So if we want to get +some conductivity, are we going to heat + + align:start position:0% +some conductivity, are we going to heat + + + align:start position:0% +some conductivity, are we going to heat +our computers up to such a high + + align:start position:0% +our computers up to such a high + + + align:start position:0% +our computers up to such a high +temperature? I don't think so. So we + + align:start position:0% +temperature? I don't think so. So we + + + align:start position:0% +temperature? I don't think so. So we +need some other way of populating the + + align:start position:0% +need some other way of populating the + + + align:start position:0% +need some other way of populating the +conduction band. And we're going to do + + align:start position:0% +conduction band. And we're going to do + + + align:start position:0% +conduction band. And we're going to do +one other mode of promotion. We've + + align:start position:0% +one other mode of promotion. We've + + + align:start position:0% +one other mode of promotion. We've +looked at photoexitation, thermal + + align:start position:0% +looked at photoexitation, thermal + + + align:start position:0% +looked at photoexitation, thermal +excitation, and the third mode is chemo + + align:start position:0% +excitation, and the third mode is chemo + + + align:start position:0% +excitation, and the third mode is chemo +excitation. + + align:start position:0% +excitation. + + + align:start position:0% +excitation. +Cheoexitation. What we're going to do is + + align:start position:0% +Cheoexitation. What we're going to do is + + + align:start position:0% +Cheoexitation. What we're going to do is +we're going to get + + align:start position:0% +we're going to get + + + align:start position:0% +we're going to get +carrier carrier + + align:start position:0% + + + + align:start position:0% + +injection by introducing + + align:start position:0% +injection by introducing + + + align:start position:0% +injection by introducing +impurities by introducing impurities. + + align:start position:0% +impurities by introducing impurities. + + + align:start position:0% +impurities by introducing impurities. +And I know you're sitting there + + align:start position:0% +And I know you're sitting there + + + align:start position:0% +And I know you're sitting there +thinking, he's crazy. We just spent all + + align:start position:0% +thinking, he's crazy. We just spent all + + + align:start position:0% +thinking, he's crazy. We just spent all +of this time and money making silicon + + align:start position:0% +of this time and money making silicon + + + align:start position:0% +of this time and money making silicon +69's purity and now we're going to start + + align:start position:0% +69's purity and now we're going to start + + + align:start position:0% +69's purity and now we're going to start +throwing impurities into it. Well, + + align:start position:0% +throwing impurities into it. Well, + + + align:start position:0% +throwing impurities into it. Well, +there's two kinds of impurities in this + + align:start position:0% +there's two kinds of impurities in this + + + align:start position:0% +there's two kinds of impurities in this +world. Two kinds of impurities. There + + align:start position:0% +world. Two kinds of impurities. There + + + align:start position:0% +world. Two kinds of impurities. There +are good impurities and bad impurities. + + align:start position:0% +are good impurities and bad impurities. + + + align:start position:0% +are good impurities and bad impurities. +All right, the good impurities are + + align:start position:0% +All right, the good impurities are + + + align:start position:0% +All right, the good impurities are +called dopants. These are the ones that + + align:start position:0% +called dopants. These are the ones that + + + align:start position:0% +called dopants. These are the ones that +are there desiraably. Okay, so dopants + + align:start position:0% +are there desiraably. Okay, so dopants + + + align:start position:0% +are there desiraably. Okay, so dopants +are good guys. And then there are other + + align:start position:0% +are good guys. And then there are other + + + align:start position:0% +are good guys. And then there are other +ones that are called + + align:start position:0% +ones that are called + + + align:start position:0% +ones that are called +contaminants. Contaminants. And these + + align:start position:0% +contaminants. Contaminants. And these + + + align:start position:0% +contaminants. Contaminants. And these +are undesirable + + align:start position:0% +are undesirable + + + align:start position:0% +are undesirable +impurities. So we don't want + + align:start position:0% +impurities. So we don't want + + + align:start position:0% +impurities. So we don't want +contaminants. So we're going to look at + + align:start position:0% +contaminants. So we're going to look at + + + align:start position:0% +contaminants. So we're going to look at +dopens. And this is a really important + + align:start position:0% +dopens. And this is a really important + + + align:start position:0% +dopens. And this is a really important +lesson right now that I'm teaching you. + + align:start position:0% +lesson right now that I'm teaching you. + + + align:start position:0% +lesson right now that I'm teaching you. +What I'm showing you for the first time + + align:start position:0% +What I'm showing you for the first time + + + align:start position:0% +What I'm showing you for the first time +in 3091 is how we can use chemistry to + + align:start position:0% +in 3091 is how we can use chemistry to + + + align:start position:0% +in 3091 is how we can use chemistry to +alter the performance of a material. I'm + + align:start position:0% +alter the performance of a material. I'm + + + align:start position:0% +alter the performance of a material. I'm +going to take plain high purity silicon + + align:start position:0% +going to take plain high purity silicon + + + align:start position:0% +going to take plain high purity silicon +which is an insulator at room + + align:start position:0% +which is an insulator at room + + + align:start position:0% +which is an insulator at room +temperature and by operating on its + + align:start position:0% +temperature and by operating on its + + + align:start position:0% +temperature and by operating on its +chemical composition give it properties + + align:start position:0% +chemical composition give it properties + + + align:start position:0% +chemical composition give it properties +that it cannot possess otherwise. So + + align:start position:0% +that it cannot possess otherwise. So + + + align:start position:0% +that it cannot possess otherwise. So +this is a paradigm. This is a paradigm + + align:start position:0% +this is a paradigm. This is a paradigm + + + align:start position:0% +this is a paradigm. This is a paradigm +for solid state chemistry. You want + + align:start position:0% +for solid state chemistry. You want + + + align:start position:0% +for solid state chemistry. You want +something that's got a higher yield + + align:start position:0% +something that's got a higher yield + + + align:start position:0% +something that's got a higher yield +strength will change its composition. + + align:start position:0% +strength will change its composition. + + + align:start position:0% +strength will change its composition. +You want something that's got a higher + + align:start position:0% +You want something that's got a higher + + + align:start position:0% +You want something that's got a higher +conductivity will change its + + align:start position:0% +conductivity will change its + + + align:start position:0% +conductivity will change its +composition. That's different. That's + + align:start position:0% +composition. That's different. That's + + + align:start position:0% +composition. That's different. That's +different. Okay. So this is an + + align:start position:0% +different. Okay. So this is an + + + align:start position:0% +different. Okay. So this is an +engineered material. This will be + + align:start position:0% +engineered material. This will be + + + align:start position:0% +engineered material. This will be +engineered material. And how is it + + align:start position:0% +engineered material. And how is it + + + align:start position:0% +engineered material. And how is it +engineered? Engineered material. What + + align:start position:0% +engineered? Engineered material. What + + + align:start position:0% +engineered? Engineered material. What +we're getting is + + align:start position:0% +we're getting is + + + align:start position:0% +we're getting is +via via chemical + + align:start position:0% +via via chemical + + + align:start position:0% +via via chemical +change. Via chemical change. Purposeful + + align:start position:0% +change. Via chemical change. Purposeful + + + align:start position:0% +change. Via chemical change. Purposeful +chemical change. So we're getting if you + + align:start position:0% +chemical change. So we're getting if you + + + align:start position:0% +chemical change. So we're getting if you +like tailored + + align:start position:0% +like tailored + + + align:start position:0% +like tailored +composition. Tailored + + align:start position:0% + + + + align:start position:0% + +composition. Tailored composition to + + align:start position:0% +composition. Tailored composition to + + + align:start position:0% +composition. Tailored composition to +give targeted properties. + + align:start position:0% +give targeted properties. + + + align:start position:0% +give targeted properties. +And this is the this is what underlies + + align:start position:0% +And this is the this is what underlies + + + align:start position:0% +And this is the this is what underlies +material science. If you don't see what + + align:start position:0% +material science. If you don't see what + + + align:start position:0% +material science. If you don't see what +you like, make it. And how do you make + + align:start position:0% +you like, make it. And how do you make + + + align:start position:0% +you like, make it. And how do you make +it? By understanding the relationship + + align:start position:0% +it? By understanding the relationship + + + align:start position:0% +it? By understanding the relationship +between electronic structure, bonding, + + align:start position:0% +between electronic structure, bonding, + + + align:start position:0% +between electronic structure, bonding, +and ultimately properties. So here's + + align:start position:0% +and ultimately properties. So here's + + + align:start position:0% +and ultimately properties. So here's +what the gambit is. Now I'm I'm going to + + align:start position:0% +what the gambit is. Now I'm I'm going to + + + align:start position:0% +what the gambit is. Now I'm I'm going to +talk only about elemental + + align:start position:0% +talk only about elemental + + + align:start position:0% +talk only about elemental +semiconductors. So in the case of in + + align:start position:0% +semiconductors. So in the case of in + + + align:start position:0% +semiconductors. So in the case of in +case of + + align:start position:0% +case of + + + align:start position:0% +case of +silicon and germanmanium I'm just going + + align:start position:0% +silicon and germanmanium I'm just going + + + align:start position:0% +silicon and germanmanium I'm just going +to red restrict today to silicon and + + align:start position:0% +to red restrict today to silicon and + + + align:start position:0% +to red restrict today to silicon and +germanmanium and that's not such a bad + + align:start position:0% +germanmanium and that's not such a bad + + + align:start position:0% +germanmanium and that's not such a bad +restriction since we're in the silicon + + align:start position:0% +restriction since we're in the silicon + + + align:start position:0% +restriction since we're in the silicon +age. All of your micro devices contain + + align:start position:0% +age. All of your micro devices contain + + + align:start position:0% +age. All of your micro devices contain +silicon. So this is pretty good. So + + align:start position:0% +silicon. So this is pretty good. So + + + align:start position:0% +silicon. So this is pretty good. So +here's the gambit. You introduce + + align:start position:0% +here's the gambit. You introduce + + + align:start position:0% +here's the gambit. You introduce +alovoent + + align:start position:0% +alovoent + + + align:start position:0% +alovoent +impurities. Introduce + + align:start position:0% +impurities. Introduce + + + align:start position:0% +impurities. Introduce +aloalent + + align:start position:0% +aloalent + + + align:start position:0% +aloalent +impurities. What do I mean alovalent? + + align:start position:0% +impurities. What do I mean alovalent? + + + align:start position:0% +impurities. What do I mean alovalent? +Alio is the same as the Latin word for + + align:start position:0% +Alio is the same as the Latin word for + + + align:start position:0% +Alio is the same as the Latin word for +alias other. So we we are going to + + align:start position:0% +alias other. So we we are going to + + + align:start position:0% +alias other. So we we are going to +introduce impurities that have a + + align:start position:0% +introduce impurities that have a + + + align:start position:0% +introduce impurities that have a +different veilance from silicon and + + align:start position:0% +different veilance from silicon and + + + align:start position:0% +different veilance from silicon and +germanmanium. Silicon and germanmanium + + align:start position:0% +germanmanium. Silicon and germanmanium + + + align:start position:0% +germanmanium. Silicon and germanmanium +are group four or group 14 if you want + + align:start position:0% +are group four or group 14 if you want + + + align:start position:0% +are group four or group 14 if you want +to use upupac notation. So what I'm + + align:start position:0% +to use upupac notation. So what I'm + + + align:start position:0% +to use upupac notation. So what I'm +going to do is introduce something else. + + align:start position:0% +going to do is introduce something else. + + + align:start position:0% +going to do is introduce something else. +I'll give you an example. So and and the + + align:start position:0% +I'll give you an example. So and and the + + + align:start position:0% +I'll give you an example. So and and the +purpose of introducing alioent + + align:start position:0% +purpose of introducing alioent + + + align:start position:0% +purpose of introducing alioent +impurities is to + + align:start position:0% +impurities is to + + + align:start position:0% +impurities is to +cause cause electron + + align:start position:0% +cause cause electron + + + align:start position:0% +cause cause electron +donation or electron + + align:start position:0% +donation or electron + + + align:start position:0% +donation or electron +consumption. And how's that going to + + align:start position:0% +consumption. And how's that going to + + + align:start position:0% +consumption. And how's that going to +work? Well, you'll see it best in + + align:start position:0% +work? Well, you'll see it best in + + + align:start position:0% +work? Well, you'll see it best in +action. So here's a simple example. + + align:start position:0% +action. So here's a simple example. + + + align:start position:0% +action. So here's a simple example. +Let's put phosphorus in silicon. + + align:start position:0% +Let's put phosphorus in silicon. + + + align:start position:0% +Let's put phosphorus in silicon. +Phosphorus, as you know, is group 15 or + + align:start position:0% +Phosphorus, as you know, is group 15 or + + + align:start position:0% +Phosphorus, as you know, is group 15 or +group five. So it's got five veence + + align:start position:0% +group five. So it's got five veence + + + align:start position:0% +group five. So it's got five veence +electrons. And let's first look at the + + align:start position:0% +electrons. And let's first look at the + + + align:start position:0% +electrons. And let's first look at the +cartisian world. So here's silicon. It's + + align:start position:0% +cartisian world. So here's silicon. It's + + + align:start position:0% +cartisian world. So here's silicon. It's +sp3 hybridized and it forms a + + align:start position:0% +sp3 hybridized and it forms a + + + align:start position:0% +sp3 hybridized and it forms a +diamondlike diamondlike solid, right? + + align:start position:0% +diamondlike diamondlike solid, right? + + + align:start position:0% +diamondlike diamondlike solid, right? +Diamondlike + + align:start position:0% +Diamondlike + + + align:start position:0% +Diamondlike +solid. So it's crystallin. It's regular + + align:start position:0% +solid. So it's crystallin. It's regular + + + align:start position:0% +solid. So it's crystallin. It's regular +arrays + + align:start position:0% +arrays + + + align:start position:0% +arrays +silicons at all of the corners of the + + align:start position:0% +silicons at all of the corners of the + + + align:start position:0% +silicons at all of the corners of the +tetrahedra. And on and on it goes. I'll + + align:start position:0% +tetrahedra. And on and on it goes. I'll + + + align:start position:0% +tetrahedra. And on and on it goes. I'll +give about three of these. + + align:start position:0% +give about three of these. + + + align:start position:0% +give about three of these. +Okay. So now what happens if I introduce + + align:start position:0% +Okay. So now what happens if I introduce + + + align:start position:0% +Okay. So now what happens if I introduce +phosphorus? If I introduce phosphorus, + + align:start position:0% +phosphorus? If I introduce phosphorus, + + + align:start position:0% +phosphorus? If I introduce phosphorus, +the phosphorus actually goes in and + + align:start position:0% +the phosphorus actually goes in and + + + align:start position:0% +the phosphorus actually goes in and +substitutes for silicon. So the + + align:start position:0% +substitutes for silicon. So the + + + align:start position:0% +substitutes for silicon. So the +phosphorus phosphorus substitutes. It + + align:start position:0% +phosphorus phosphorus substitutes. It + + + align:start position:0% +phosphorus phosphorus substitutes. It +doesn't go and sit in some void space. + + align:start position:0% +doesn't go and sit in some void space. + + + align:start position:0% +doesn't go and sit in some void space. +It actually + + align:start position:0% +It actually + + + align:start position:0% +It actually +substitutes substitutes for silicon. Now + + align:start position:0% +substitutes substitutes for silicon. Now + + + align:start position:0% +substitutes substitutes for silicon. Now +if it's going to substitute for silicon, + + align:start position:0% +if it's going to substitute for silicon, + + + align:start position:0% +if it's going to substitute for silicon, +it has to form bonds. Agreed? You can't + + align:start position:0% +it has to form bonds. Agreed? You can't + + + align:start position:0% +it has to form bonds. Agreed? You can't +just sit there. There's no passive + + align:start position:0% +just sit there. There's no passive + + + align:start position:0% +just sit there. There's no passive +observer here. If you want to play, you + + align:start position:0% +observer here. If you want to play, you + + + align:start position:0% +observer here. If you want to play, you +got to bond. So phosphorus comes in with + + align:start position:0% +got to bond. So phosphorus comes in with + + + align:start position:0% +got to bond. So phosphorus comes in with +five veence electrons. So it goes 1 2 3 + + align:start position:0% +five veence electrons. So it goes 1 2 3 + + + align:start position:0% +five veence electrons. So it goes 1 2 3 +four. There's four of its veence + + align:start position:0% +four. There's four of its veence + + + align:start position:0% +four. There's four of its veence +electrons are bonding to the four + + align:start position:0% +electrons are bonding to the four + + + align:start position:0% +electrons are bonding to the four +adjacent silicons. What happens to the + + align:start position:0% +adjacent silicons. What happens to the + + + align:start position:0% +adjacent silicons. What happens to the +fifth veence electron of phosphorus. + + align:start position:0% +fifth veence electron of phosphorus. + + + align:start position:0% +fifth veence electron of phosphorus. +There's no empty orbital in which that + + align:start position:0% +There's no empty orbital in which that + + + align:start position:0% +There's no empty orbital in which that +fifth electron can sit. So that fifth + + align:start position:0% +fifth electron can sit. So that fifth + + + align:start position:0% +fifth electron can sit. So that fifth +electron is sitting here kind of tapping + + align:start position:0% +electron is sitting here kind of tapping + + + align:start position:0% +electron is sitting here kind of tapping +its foot wondering what it's going to + + align:start position:0% +its foot wondering what it's going to + + + align:start position:0% +its foot wondering what it's going to +do. Right now let's go over to the + + align:start position:0% +do. Right now let's go over to the + + + align:start position:0% +do. Right now let's go over to the +energy level diagram. Here's the energy + + align:start position:0% +energy level diagram. Here's the energy + + + align:start position:0% +energy level diagram. Here's the energy +level diagram. This is silicon elemental + + align:start position:0% +level diagram. This is silicon elemental + + + align:start position:0% +level diagram. This is silicon elemental +silicon. Downstairs is veance band. + + align:start position:0% +silicon. Downstairs is veance band. + + + align:start position:0% +silicon. Downstairs is veance band. +Upstairs is conduction band. When we put + + align:start position:0% +Upstairs is conduction band. When we put + + + align:start position:0% +Upstairs is conduction band. When we put +the phosphorus into the silicon, where + + align:start position:0% +the phosphorus into the silicon, where + + + align:start position:0% +the phosphorus into the silicon, where +in energy space, where's the only place + + align:start position:0% +in energy space, where's the only place + + + align:start position:0% +in energy space, where's the only place +that fifth electron can + + align:start position:0% +that fifth electron can + + + align:start position:0% +that fifth electron can +go? There's no room at the end down + + align:start position:0% +go? There's no room at the end down + + + align:start position:0% +go? There's no room at the end down +here. All of the veence orbitals are + + align:start position:0% +here. All of the veence orbitals are + + + align:start position:0% +here. All of the veence orbitals are +filled. So the only place it can go is + + align:start position:0% +filled. So the only place it can go is + + + align:start position:0% +filled. So the only place it can go is +up here in the conduction band. So + + align:start position:0% +up here in the conduction band. So + + + align:start position:0% +up here in the conduction band. So +here's the electron that came from + + align:start position:0% +here's the electron that came from + + + align:start position:0% +here's the electron that came from +phosphorus. that was donated from + + align:start position:0% +phosphorus. that was donated from + + + align:start position:0% +phosphorus. that was donated from +phosphorus. We call phosphorus a donor. + + align:start position:0% +phosphorus. We call phosphorus a donor. + + + align:start position:0% +phosphorus. We call phosphorus a donor. +Okay, this is a donor + + align:start position:0% +Okay, this is a donor + + + align:start position:0% +Okay, this is a donor +electron. And can you see that every + + align:start position:0% +electron. And can you see that every + + + align:start position:0% +electron. And can you see that every +time I throw a phosphorus in, I'm going + + align:start position:0% +time I throw a phosphorus in, I'm going + + + align:start position:0% +time I throw a phosphorus in, I'm going +to get an extra electron in the + + align:start position:0% +to get an extra electron in the + + + align:start position:0% +to get an extra electron in the +conduction band. So if I want to + + align:start position:0% +conduction band. So if I want to + + + align:start position:0% +conduction band. So if I want to +increase the conductivity of silicon, + + align:start position:0% +increase the conductivity of silicon, + + + align:start position:0% +increase the conductivity of silicon, +just keep adding + + align:start position:0% +just keep adding + + + align:start position:0% +just keep adding +phosphorus. One for one. Oh, but am I am + + align:start position:0% +phosphorus. One for one. Oh, but am I am + + + align:start position:0% +phosphorus. One for one. Oh, but am I am +I making holes down here? No, I'm not + + align:start position:0% +I making holes down here? No, I'm not + + + align:start position:0% +I making holes down here? No, I'm not +breaking any bonds. In fact, I'm forming + + align:start position:0% +breaking any bonds. In fact, I'm forming + + + align:start position:0% +breaking any bonds. In fact, I'm forming +bonds here. There's an extra electron. + + align:start position:0% +bonds here. There's an extra electron. + + + align:start position:0% +bonds here. There's an extra electron. +Everything's fine. So now I can I've got + + align:start position:0% +Everything's fine. So now I can I've got + + + align:start position:0% +Everything's fine. So now I can I've got +a lever. I can I can dial in how much + + align:start position:0% +a lever. I can I can dial in how much + + + align:start position:0% +a lever. I can I can dial in how much +conductivity I + + align:start position:0% +conductivity I + + + align:start position:0% +conductivity I +want. You want to raise the conductivity + + align:start position:0% +want. You want to raise the conductivity + + + align:start position:0% +want. You want to raise the conductivity +to a certain value. I can tell you how + + align:start position:0% +to a certain value. I can tell you how + + + align:start position:0% +to a certain value. I can tell you how +much phosphorus to add to get to that + + align:start position:0% +much phosphorus to add to get to that + + + align:start position:0% +much phosphorus to add to get to that +level of + + align:start position:0% + + + + align:start position:0% + +conductivity. And this electron is not + + align:start position:0% +conductivity. And this electron is not + + + align:start position:0% +conductivity. And this electron is not +in a veence band. It's not bound. So it + + align:start position:0% +in a veence band. It's not bound. So it + + + align:start position:0% +in a veence band. It's not bound. So it +can move. So this this goes back to Paul + + align:start position:0% +can move. So this this goes back to Paul + + + align:start position:0% +can move. So this this goes back to Paul +Duda. the these electrons are free to + + align:start position:0% +Duda. the these electrons are free to + + + align:start position:0% +Duda. the these electrons are free to +roam because they're not + + align:start position:0% +roam because they're not + + + align:start position:0% +roam because they're not +bound. But I'm going to show you + + align:start position:0% +bound. But I'm going to show you + + + align:start position:0% +bound. But I'm going to show you +something. I'm going to show you + + align:start position:0% +something. I'm going to show you + + + align:start position:0% +something. I'm going to show you +something really cool. Um how far can + + align:start position:0% +something really cool. Um how far can + + + align:start position:0% +something really cool. Um how far can +that electron roam? So think about it. + + align:start position:0% +that electron roam? So think about it. + + + align:start position:0% +that electron roam? So think about it. +Phosphorus is a five five veent. So it's + + align:start position:0% +Phosphorus is a five five veent. So it's + + + align:start position:0% +Phosphorus is a five five veent. So it's +got an extra proton too, right? So this + + align:start position:0% +got an extra proton too, right? So this + + + align:start position:0% +got an extra proton too, right? So this +phosphorus is a five plus and a land of + + align:start position:0% +phosphorus is a five plus and a land of + + + align:start position:0% +phosphorus is a five plus and a land of +4 plus. So the phosphorus you can think + + align:start position:0% +4 plus. So the phosphorus you can think + + + align:start position:0% +4 plus. So the phosphorus you can think +of as locally plus. And this electron + + align:start position:0% +of as locally plus. And this electron + + + align:start position:0% +of as locally plus. And this electron +that didn't go into any of the veence + + align:start position:0% +that didn't go into any of the veence + + + align:start position:0% +that didn't go into any of the veence +band orbitals, you it's it's locally + + align:start position:0% +band orbitals, you it's it's locally + + + align:start position:0% +band orbitals, you it's it's locally +minus. Duh. An electron is locally + + align:start position:0% +minus. Duh. An electron is locally + + + align:start position:0% +minus. Duh. An electron is locally +minus. That's deep. Okay. So here I've + + align:start position:0% +minus. That's deep. Okay. So here I've + + + align:start position:0% +minus. That's deep. Okay. So here I've +got the phosphorus that's locally plus + + align:start position:0% +got the phosphorus that's locally plus + + + align:start position:0% +got the phosphorus that's locally plus +and I got the electron that's locally + + align:start position:0% +and I got the electron that's locally + + + align:start position:0% +and I got the electron that's locally +minus. Do you know of a model that might + + align:start position:0% +minus. Do you know of a model that might + + + align:start position:0% +minus. Do you know of a model that might +describe the motion of an anchored + + align:start position:0% +describe the motion of an anchored + + + align:start position:0% +describe the motion of an anchored +positive charge with an electron that's + + align:start position:0% +positive charge with an electron that's + + + align:start position:0% +positive charge with an electron that's +free to roam? Do you know of a model + + align:start position:0% +free to roam? Do you know of a model + + + align:start position:0% +free to roam? Do you know of a model +that might talk about such + + align:start position:0% +that might talk about such + + + align:start position:0% +that might talk about such +things? Bore. So let's do something + + align:start position:0% +things? Bore. So let's do something + + + align:start position:0% +things? Bore. So let's do something +really whacked. Suppose we said we took + + align:start position:0% +really whacked. Suppose we said we took + + + align:start position:0% +really whacked. Suppose we said we took +this electron and we said let's let's + + align:start position:0% +this electron and we said let's let's + + + align:start position:0% +this electron and we said let's let's +ask the question if we applied the bore + + align:start position:0% +ask the question if we applied the bore + + + align:start position:0% +ask the question if we applied the bore +model to this pair. What would we come + + align:start position:0% +model to this pair. What would we come + + + align:start position:0% +model to this pair. What would we come +up with? I mean it's going to give us + + align:start position:0% +up with? I mean it's going to give us + + + align:start position:0% +up with? I mean it's going to give us +energies. It's going to give us radi. + + align:start position:0% +energies. It's going to give us radi. + + + align:start position:0% +energies. It's going to give us radi. +It's going to give us velocities. Do you + + align:start position:0% +It's going to give us velocities. Do you + + + align:start position:0% +It's going to give us velocities. Do you +think there might be a relationship to + + align:start position:0% +think there might be a relationship to + + + align:start position:0% +think there might be a relationship to +velocity and mobility and conductivity + + align:start position:0% +velocity and mobility and conductivity + + + align:start position:0% +velocity and mobility and conductivity +and well let's see where it goes. So + + align:start position:0% +and well let's see where it goes. So + + + align:start position:0% +and well let's see where it goes. So +let's go. Um, so what I'm going to do is + + align:start position:0% +let's go. Um, so what I'm going to do is + + + align:start position:0% +let's go. Um, so what I'm going to do is +I'm going to say remember in recall in + + align:start position:0% +I'm going to say remember in recall in + + + align:start position:0% +I'm going to say remember in recall in +hydrogen and atomic hydrogen recall in + + align:start position:0% +hydrogen and atomic hydrogen recall in + + + align:start position:0% +hydrogen and atomic hydrogen recall in +atomic hydrogen the ground state energy + + align:start position:0% +atomic hydrogen the ground state energy + + + align:start position:0% +atomic hydrogen the ground state energy +this is the electron at the bottom of + + align:start position:0% +this is the electron at the bottom of + + + align:start position:0% +this is the electron at the bottom of +the is minus K what we've been calling K + + align:start position:0% +the is minus K what we've been calling K + + + align:start position:0% +the is minus K what we've been calling K +which has this uh full full-blown + + align:start position:0% +which has this uh full full-blown + + + align:start position:0% +which has this uh full full-blown +formula of me to 4 over 8 epsilon0^ 2 + + align:start position:0% +formula of me to 4 over 8 epsilon0^ 2 + + + align:start position:0% +formula of me to 4 over 8 epsilon0^ 2 +h^2 and plug in all the numbers and you + + align:start position:0% +h^2 and plug in all the numbers and you + + + align:start position:0% +h^2 and plug in all the numbers and you +get -3.6 6 electron volts -3.6 electron + + align:start position:0% +get -3.6 6 electron volts -3.6 electron + + + align:start position:0% +get -3.6 6 electron volts -3.6 electron +volts. Now let's think about this. What + + align:start position:0% +volts. Now let's think about this. What + + + align:start position:0% +volts. Now let's think about this. What +we're going to have to make a few + + align:start position:0% +we're going to have to make a few + + + align:start position:0% +we're going to have to make a few +changes. Uh epsilon0 that's the + + align:start position:0% +changes. Uh epsilon0 that's the + + + align:start position:0% +changes. Uh epsilon0 that's the +permitivity of vacuum. But if you're if + + align:start position:0% +permitivity of vacuum. But if you're if + + + align:start position:0% +permitivity of vacuum. But if you're if +you're an electron, you're looking down + + align:start position:0% +you're an electron, you're looking down + + + align:start position:0% +you're an electron, you're looking down +at the phosphorus. It's not just vacuum + + align:start position:0% +at the phosphorus. It's not just vacuum + + + align:start position:0% +at the phosphorus. It's not just vacuum +between you and the central phosphorus. + + align:start position:0% +between you and the central phosphorus. + + + align:start position:0% +between you and the central phosphorus. +There's all this stuff. There's bonds. + + align:start position:0% +There's all this stuff. There's bonds. + + + align:start position:0% +There's all this stuff. There's bonds. +There's silica + + align:start position:0% +There's silica + + + align:start position:0% +There's silica +nuclei. So I got to modify this. I've + + align:start position:0% +nuclei. So I got to modify this. I've + + + align:start position:0% +nuclei. So I got to modify this. I've +got to I've got to change this. So what + + align:start position:0% +got to I've got to change this. So what + + + align:start position:0% +got to I've got to change this. So what +I'm going to do is I'm going to take + + align:start position:0% +I'm going to do is I'm going to take + + + align:start position:0% +I'm going to do is I'm going to take +epsilon0 which is what we have for + + align:start position:0% +epsilon0 which is what we have for + + + align:start position:0% +epsilon0 which is what we have for +vacuum and I'm going to replace it with + + align:start position:0% +vacuum and I'm going to replace it with + + + align:start position:0% +vacuum and I'm going to replace it with +epsilon epsilon of silicon epsilon of + + align:start position:0% +epsilon epsilon of silicon epsilon of + + + align:start position:0% +epsilon epsilon of silicon epsilon of +silicon. Silicon is the host crystal. So + + align:start position:0% +silicon. Silicon is the host crystal. So + + + align:start position:0% +silicon. Silicon is the host crystal. So +what does it what does this capture? + + align:start position:0% +what does it what does this capture? + + + align:start position:0% +what does it what does this capture? +Captures all the bonds all of the + + align:start position:0% +Captures all the bonds all of the + + + align:start position:0% +Captures all the bonds all of the +silicon all of the stuff. Okay. So + + align:start position:0% +silicon all of the stuff. Okay. So + + + align:start position:0% +silicon all of the stuff. Okay. So +that's the the dialectric + + align:start position:0% +that's the the dialectric + + + align:start position:0% +that's the the dialectric +constant. That's the dialectric + + align:start position:0% +constant. That's the dialectric + + + align:start position:0% +constant. That's the dialectric +constant of the host crystal. + + align:start position:0% + + + + align:start position:0% + +And there's one other thing. This is + + align:start position:0% +And there's one other thing. This is + + + align:start position:0% +And there's one other thing. This is +some esoteric physics. I'm just going to + + align:start position:0% +some esoteric physics. I'm just going to + + + align:start position:0% +some esoteric physics. I'm just going to +put it up here without without proof. + + align:start position:0% +put it up here without without proof. + + + align:start position:0% +put it up here without without proof. +When you're in this situation, you don't + + align:start position:0% +When you're in this situation, you don't + + + align:start position:0% +When you're in this situation, you don't +use the the rest mass. There is an + + align:start position:0% +use the the rest mass. There is an + + + align:start position:0% +use the the rest mass. There is an +effective mass. The effective mass and + + align:start position:0% +effective mass. The effective mass and + + + align:start position:0% +effective mass. The effective mass and +that in invokes a slight uh correction. + + align:start position:0% +that in invokes a slight uh correction. + + + align:start position:0% +that in invokes a slight uh correction. +The effective + + align:start position:0% +The effective + + + align:start position:0% +The effective +mass of the electron at the bottom of + + align:start position:0% +mass of the electron at the bottom of + + + align:start position:0% +mass of the electron at the bottom of +the conduction band. Bottom of + + align:start position:0% +the conduction band. Bottom of + + + align:start position:0% +the conduction band. Bottom of +conduction band. This is a minor + + align:start position:0% +conduction band. This is a minor + + + align:start position:0% +conduction band. This is a minor +correction. And the main correction is + + align:start position:0% +correction. And the main correction is + + + align:start position:0% +correction. And the main correction is +getting the dialectric constant. Okay. + + align:start position:0% +getting the dialectric constant. Okay. + + + align:start position:0% +getting the dialectric constant. Okay. +So the second one is there for + + align:start position:0% +So the second one is there for + + + align:start position:0% +So the second one is there for +completeness. Some of you are going to + + align:start position:0% +completeness. Some of you are going to + + + align:start position:0% +completeness. Some of you are going to +look back fondly at at at these notes + + align:start position:0% +look back fondly at at at these notes + + + align:start position:0% +look back fondly at at at these notes +and say yeah we got it. This was good. + + align:start position:0% +and say yeah we got it. This was good. + + + align:start position:0% +and say yeah we got it. This was good. +Otherwise you say how do we lift out the + + align:start position:0% +Otherwise you say how do we lift out the + + + align:start position:0% +Otherwise you say how do we lift out the +effective mass? So can't say that now. + + align:start position:0% +effective mass? So can't say that now. + + + align:start position:0% +effective mass? So can't say that now. +All right. So here's the here are the + + align:start position:0% +All right. So here's the here are the + + + align:start position:0% +All right. So here's the here are the +values for silicon. For silicon the uh + + align:start position:0% +values for silicon. For silicon the uh + + + align:start position:0% +values for silicon. For silicon the uh +dialectric uh constant is 11.7 and the + + align:start position:0% +dialectric uh constant is 11.7 and the + + + align:start position:0% +dialectric uh constant is 11.7 and the +effective mass at the bottom of the + + align:start position:0% +effective mass at the bottom of the + + + align:start position:0% +effective mass at the bottom of the +conduction band is 15th of the rest + + align:start position:0% +conduction band is 15th of the rest + + + align:start position:0% +conduction band is 15th of the rest +mass. So I'm going to plug these values + + align:start position:0% +mass. So I'm going to plug these values + + + align:start position:0% +mass. So I'm going to plug these values +into this equation. And what this gives + + align:start position:0% +into this equation. And what this gives + + + align:start position:0% +into this equation. And what this gives +me is then that the ground state energy + + align:start position:0% +me is then that the ground state energy + + + align:start position:0% +me is then that the ground state energy +of the donor electron is minus K as we + + align:start position:0% +of the donor electron is minus K as we + + + align:start position:0% +of the donor electron is minus K as we +had before and it's going to be + + align:start position:0% +had before and it's going to be + + + align:start position:0% +had before and it's going to be +multiplied by 0.2 on the top and then + + align:start position:0% +multiplied by 0.2 on the top and then + + + align:start position:0% +multiplied by 0.2 on the top and then +I'm going to have an 11.7 + + align:start position:0% +I'm going to have an 11.7 + + + align:start position:0% +I'm going to have an 11.7 +uh squared on the bottom. And that gives + + align:start position:0% +uh squared on the bottom. And that gives + + + align:start position:0% +uh squared on the bottom. And that gives +me minus + + align:start position:0% +me minus + + + align:start position:0% +me minus +0.02 electron volts. 2100s of electron + + align:start position:0% +0.02 electron volts. 2100s of electron + + + align:start position:0% +0.02 electron volts. 2100s of electron +volt. + + align:start position:0% +volt. + + + align:start position:0% +volt. +This quantity has been measured. The + + align:start position:0% +This quantity has been measured. The + + + align:start position:0% +This quantity has been measured. The +measured + + align:start position:0% +measured + + + align:start position:0% +measured +value compare with CF CF + + align:start position:0% +value compare with CF CF + + + align:start position:0% +value compare with CF CF +0.045 + + align:start position:0% +0.045 + + + align:start position:0% +0.045 +EV measured. And you might say, well, + + align:start position:0% +EV measured. And you might say, well, + + + align:start position:0% +EV measured. And you might say, well, +that's more than double that. And I'll + + align:start position:0% +that's more than double that. And I'll + + + align:start position:0% +that's more than double that. And I'll +say, but wait a minute. You know, we + + align:start position:0% +say, but wait a minute. You know, we + + + align:start position:0% +say, but wait a minute. You know, we +started at 13.6 and I took it down to 02 + + align:start position:0% +started at 13.6 and I took it down to 02 + + + align:start position:0% +started at 13.6 and I took it down to 02 +and you're telling me, yeah, but the + + align:start position:0% +and you're telling me, yeah, but the + + + align:start position:0% +and you're telling me, yeah, but the +real value is 04. I said, you don't + + align:start position:0% +real value is 04. I said, you don't + + + align:start position:0% +real value is 04. I said, you don't +appreciate good work. That's what this + + align:start position:0% +appreciate good work. That's what this + + + align:start position:0% +appreciate good work. That's what this +is. Fantastic. This is fantastic with a + + align:start position:0% +is. Fantastic. This is fantastic with a + + + align:start position:0% +is. Fantastic. This is fantastic with a +simple primitive bore model and two + + align:start position:0% +simple primitive bore model and two + + + align:start position:0% +simple primitive bore model and two +minor corrections to zoom into condensed + + align:start position:0% +minor corrections to zoom into condensed + + + align:start position:0% +minor corrections to zoom into condensed +matter and give this + + align:start position:0% +matter and give this + + + align:start position:0% +matter and give this +value. So where is that going to be? + + align:start position:0% +value. So where is that going to be? + + + align:start position:0% +value. So where is that going to be? +Where's that going to be? + + align:start position:0% +Where's that going to be? + + + align:start position:0% +Where's that going to be? +02 south of what? It's going to be here. + + align:start position:0% +02 south of what? It's going to be here. + + + align:start position:0% +02 south of what? It's going to be here. +This is where that lies. This distance + + align:start position:0% +This is where that lies. This distance + + + align:start position:0% +This is where that lies. This distance +here is the + + align:start position:0% +here is the + + + align:start position:0% +here is the +0.02 electron volt difference. You're + + align:start position:0% +0.02 electron volt difference. You're + + + align:start position:0% +0.02 electron volt difference. You're +0.02 002 electron volts below the + + align:start position:0% +0.02 002 electron volts below the + + + align:start position:0% +0.02 002 electron volts below the +conduction band. You're not down here. + + align:start position:0% +conduction band. You're not down here. + + + align:start position:0% +conduction band. You're not down here. +This is veilance. You're up + + align:start position:0% +This is veilance. You're up + + + align:start position:0% +This is veilance. You're up +top and the electrons sitting in there + + align:start position:0% +top and the electrons sitting in there + + + align:start position:0% +top and the electrons sitting in there +because that's a ground state. So now + + align:start position:0% +because that's a ground state. So now + + + align:start position:0% +because that's a ground state. So now +you're saying, "Well, that's really + + align:start position:0% +you're saying, "Well, that's really + + + align:start position:0% +you're saying, "Well, that's really +great, Satway. Now you've got an + + align:start position:0% +great, Satway. Now you've got an + + + align:start position:0% +great, Satway. Now you've got an +electron sitting in an orbital. Now, how + + align:start position:0% +electron sitting in an orbital. Now, how + + + align:start position:0% +electron sitting in an orbital. Now, how +are you going to get it up to here?" I + + align:start position:0% +are you going to get it up to here?" I + + + align:start position:0% +are you going to get it up to here?" I +got an answer for that. But first, first + + align:start position:0% +got an answer for that. But first, first + + + align:start position:0% +got an answer for that. But first, first +look at this. I I couldn't resist this + + align:start position:0% +look at this. I I couldn't resist this + + + align:start position:0% +look at this. I I couldn't resist this +derivation. I said, "What about the + + align:start position:0% +derivation. I said, "What about the + + + align:start position:0% +derivation. I said, "What about the +radius of the orbit? How far is that + + align:start position:0% +radius of the orbit? How far is that + + + align:start position:0% +radius of the orbit? How far is that +electron away from the phosphorus? You + + align:start position:0% +electron away from the phosphorus? You + + + align:start position:0% +electron away from the phosphorus? You +know, is it in tight? Is it in moving + + align:start position:0% +know, is it in tight? Is it in moving + + + align:start position:0% +know, is it in tight? Is it in moving +around like this? Or is it way way out + + align:start position:0% +around like this? Or is it way way out + + + align:start position:0% +around like this? Or is it way way out +here? Doesn't that intrigue + + align:start position:0% +here? Doesn't that intrigue + + + align:start position:0% +here? Doesn't that intrigue +you? Sure intrigues me. So, here's what + + align:start position:0% +you? Sure intrigues me. So, here's what + + + align:start position:0% +you? Sure intrigues me. So, here's what +I did. I said, "Okay, the R1, the radius + + align:start position:0% +I did. I said, "Okay, the R1, the radius + + + align:start position:0% +I did. I said, "Okay, the R1, the radius +of this ground state was going to be + + align:start position:0% +of this ground state was going to be + + + align:start position:0% +of this ground state was going to be +given by the bore radius times the + + align:start position:0% +given by the bore radius times the + + + align:start position:0% +given by the bore radius times the +modified dialectric constant divided by + + align:start position:0% +modified dialectric constant divided by + + + align:start position:0% +modified dialectric constant divided by +the modified mass. And when you plug in + + align:start position:0% +the modified mass. And when you plug in + + + align:start position:0% +the modified mass. And when you plug in +the numbers, you get 30 angstroms." 30 + + align:start position:0% +the numbers, you get 30 angstroms." 30 + + + align:start position:0% +the numbers, you get 30 angstroms." 30 +angstroms. We say, well, I don't know + + align:start position:0% +angstroms. We say, well, I don't know + + + align:start position:0% +angstroms. We say, well, I don't know +what the silicon silicon distance is. + + align:start position:0% +what the silicon silicon distance is. + + + align:start position:0% +what the silicon silicon distance is. +Well, what do you think it is? I mean, + + align:start position:0% +Well, what do you think it is? I mean, + + + align:start position:0% +Well, what do you think it is? I mean, +you know, it's got to be on the order of + + align:start position:0% +you know, it's got to be on the order of + + + align:start position:0% +you know, it's got to be on the order of +a couple of angstroms. So, if you + + align:start position:0% +a couple of angstroms. So, if you + + + align:start position:0% +a couple of angstroms. So, if you +compare that, the silicon silicon + + align:start position:0% +compare that, the silicon silicon + + + align:start position:0% +compare that, the silicon silicon +distance is + + align:start position:0% +distance is + + + align:start position:0% +distance is +2.35 angstroms. So, this electron's way + + align:start position:0% +2.35 angstroms. So, this electron's way + + + align:start position:0% +2.35 angstroms. So, this electron's way +way zooming + + align:start position:0% + + + + align:start position:0% + +around. + + align:start position:0% +around. + + + align:start position:0% +around. +So, fantastic what we've learned here. + + align:start position:0% +So, fantastic what we've learned here. + + + align:start position:0% +So, fantastic what we've learned here. +Now, let's look at this. So, we've got + + align:start position:0% +Now, let's look at this. So, we've got + + + align:start position:0% +Now, let's look at this. So, we've got +electrons sitting in this uh uh energy + + align:start position:0% +electrons sitting in this uh uh energy + + + align:start position:0% +electrons sitting in this uh uh energy +level down below. And now what happens? + + align:start position:0% +level down below. And now what happens? + + + align:start position:0% +level down below. And now what happens? +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +um how do how do I get this thing to how + + align:start position:0% +um how do how do I get this thing to how + + + align:start position:0% +um how do how do I get this thing to how +do I get this thing to move out? What + + align:start position:0% +do I get this thing to move out? What + + + align:start position:0% +do I get this thing to move out? What +I'm going to do to make it move out? + + align:start position:0% +I'm going to do to make it move out? + + + align:start position:0% +I'm going to do to make it move out? +Well, what do I have? I know that the + + align:start position:0% +Well, what do I have? I know that the + + + align:start position:0% +Well, what do I have? I know that the +energy is 0.02. But what's the comp how + + align:start position:0% +energy is 0.02. But what's the comp how + + + align:start position:0% +energy is 0.02. But what's the comp how +do I compare this energy with compare + + align:start position:0% +do I compare this energy with compare + + + align:start position:0% +do I compare this energy with compare +this with the thermal energy? Ether + + align:start position:0% +this with the thermal energy? Ether + + + align:start position:0% +this with the thermal energy? Ether +thermal is on the order of 0.025140th + + align:start position:0% +thermal is on the order of 0.025140th + + + align:start position:0% +thermal is on the order of 0.025140th +025140th of an EV. So the thermal energy + + align:start position:0% +025140th of an EV. So the thermal energy + + + align:start position:0% +025140th of an EV. So the thermal energy +is so high at room temperature that it's + + align:start position:0% +is so high at room temperature that it's + + + align:start position:0% +is so high at room temperature that it's +able to promote these. And by the way, + + align:start position:0% +able to promote these. And by the way, + + + align:start position:0% +able to promote these. And by the way, +you know, if this war model works for + + align:start position:0% +you know, if this war model works for + + + align:start position:0% +you know, if this war model works for +ground state, what would happen if I + + align:start position:0% +ground state, what would happen if I + + + align:start position:0% +ground state, what would happen if I +were to blow this up? Can you imagine + + align:start position:0% +were to blow this up? Can you imagine + + + align:start position:0% +were to blow this up? Can you imagine +that? I have, if this is the conduction + + align:start position:0% +that? I have, if this is the conduction + + + align:start position:0% +that? I have, if this is the conduction +band, I get all of the energy + + align:start position:0% +band, I get all of the energy + + + align:start position:0% +band, I get all of the energy +levels. I get the whole bore energy + + align:start position:0% +levels. I get the whole bore energy + + + align:start position:0% +levels. I get the whole bore energy +state here. I get ground state n= 2, n= + + align:start position:0% +state here. I get ground state n= 2, n= + + + align:start position:0% +state here. I get ground state n= 2, n= +3, all the way + + align:start position:0% +3, all the way + + + align:start position:0% +3, all the way +up. And now I have enough energy from + + align:start position:0% +up. And now I have enough energy from + + + align:start position:0% +up. And now I have enough energy from +thermal energy to take all of these + + align:start position:0% +thermal energy to take all of these + + + align:start position:0% +thermal energy to take all of these +electrons because each one of these + + align:start position:0% +electrons because each one of these + + + align:start position:0% +electrons because each one of these +comes in because it's a separate + + align:start position:0% +comes in because it's a separate + + + align:start position:0% +comes in because it's a separate +phosphorus and they're far enough apart. + + align:start position:0% +phosphorus and they're far enough apart. + + + align:start position:0% +phosphorus and they're far enough apart. +They're separate states. All of these + + align:start position:0% +They're separate states. All of these + + + align:start position:0% +They're separate states. All of these +can get promoted. What do we call this + + align:start position:0% +can get promoted. What do we call this + + + align:start position:0% +can get promoted. What do we call this +action? If I take a ground state + + align:start position:0% +action? If I take a ground state + + + align:start position:0% +action? If I take a ground state +electron and hydrogen and I get it right + + align:start position:0% +electron and hydrogen and I get it right + + + align:start position:0% +electron and hydrogen and I get it right +out of all of this set of energy levels, + + align:start position:0% +out of all of this set of energy levels, + + + align:start position:0% +out of all of this set of energy levels, +what do we call that process? We take + + align:start position:0% +what do we call that process? We take + + + align:start position:0% +what do we call that process? We take +the electron and we throw it out of the + + align:start position:0% +the electron and we throw it out of the + + + align:start position:0% +the electron and we throw it out of the +system. Ionization. And that's exactly + + align:start position:0% +system. Ionization. And that's exactly + + + align:start position:0% +system. Ionization. And that's exactly +what the electrical engineers call this + + align:start position:0% +what the electrical engineers call this + + + align:start position:0% +what the electrical engineers call this +process. They call the thermal + + align:start position:0% +process. They call the thermal + + + align:start position:0% +process. They call the thermal +excitation of the donor electrons + + align:start position:0% +excitation of the donor electrons + + + align:start position:0% +excitation of the donor electrons +ionization. So for all intents and + + align:start position:0% +ionization. So for all intents and + + + align:start position:0% +ionization. So for all intents and +purposes because ether thermal is on the + + align:start position:0% +purposes because ether thermal is on the + + + align:start position:0% +purposes because ether thermal is on the +order of this e of the donor electron we + + align:start position:0% +order of this e of the donor electron we + + + align:start position:0% +order of this e of the donor electron we +can we can + + align:start position:0% +can we can + + + align:start position:0% +can we can +assume assume + + align:start position:0% +assume assume + + + align:start position:0% +assume assume +complete and I'm going to use an + + align:start position:0% +complete and I'm going to use an + + + align:start position:0% +complete and I'm going to use an +electrical engineering term here because + + align:start position:0% +electrical engineering term here because + + + align:start position:0% +electrical engineering term here because +I think I'm still teaching in an + + align:start position:0% +I think I'm still teaching in an + + + align:start position:0% +I think I'm still teaching in an +engineering school complete + + align:start position:0% +engineering school complete + + + align:start position:0% +engineering school complete +ionization of donor electrons. + + align:start position:0% + + + + align:start position:0% + +Oh, this is fantastic. That's fantastic. + + align:start position:0% +Oh, this is fantastic. That's fantastic. + + + align:start position:0% +Oh, this is fantastic. That's fantastic. +They're all ionized. So now, last day I + + align:start position:0% +They're all ionized. So now, last day I + + + align:start position:0% +They're all ionized. So now, last day I +said that the total number of electrons + + align:start position:0% +said that the total number of electrons + + + align:start position:0% +said that the total number of electrons +in the conduction band would equal the + + align:start position:0% +in the conduction band would equal the + + + align:start position:0% +in the conduction band would equal the +number of electrons from the host + + align:start position:0% +number of electrons from the host + + + align:start position:0% +number of electrons from the host +silica, right? host silicon due to + + align:start position:0% +silica, right? host silicon due to + + + align:start position:0% +silica, right? host silicon due to +thermal + + align:start position:0% + + + + align:start position:0% + +excitation plus it's going to be the + + align:start position:0% +excitation plus it's going to be the + + + align:start position:0% +excitation plus it's going to be the +number of electrons from the + + align:start position:0% +number of electrons from the + + + align:start position:0% +number of electrons from the +impur + + align:start position:0% +impur + + + align:start position:0% +impur +phosphorus + + align:start position:0% + + + + align:start position:0% + +okay and we know this requires eg on the + + align:start position:0% +okay and we know this requires eg on the + + + align:start position:0% +okay and we know this requires eg on the +order of about 1.1 eV so very few of + + align:start position:0% +order of about 1.1 eV so very few of + + + align:start position:0% +order of about 1.1 eV so very few of +these are contributed there's almost no + + align:start position:0% +these are contributed there's almost no + + + align:start position:0% +these are contributed there's almost no +promotion of electron + + align:start position:0% +promotion of electron + + + align:start position:0% +promotion of electron +from the veance band to the conduction + + align:start position:0% +from the veance band to the conduction + + + align:start position:0% +from the veance band to the conduction +band to leave holes. This is vanishingly + + align:start position:0% +band to leave holes. This is vanishingly + + + align:start position:0% +band to leave holes. This is vanishingly +small at room temperature in silicon. + + align:start position:0% +small at room temperature in silicon. + + + align:start position:0% +small at room temperature in silicon. +Whereas here because the I'm going to + + align:start position:0% +Whereas here because the I'm going to + + + align:start position:0% +Whereas here because the I'm going to +put in quotation marks the ionization + + align:start position:0% +put in quotation marks the ionization + + + align:start position:0% +put in quotation marks the ionization +energy is on the order of the thermal + + align:start position:0% +energy is on the order of the thermal + + + align:start position:0% +energy is on the order of the thermal +energy we get all the electrons from + + align:start position:0% +energy we get all the electrons from + + + align:start position:0% +energy we get all the electrons from +here. And so in such a material we say + + align:start position:0% +here. And so in such a material we say + + + align:start position:0% +here. And so in such a material we say +that the electrical properties are + + align:start position:0% +that the electrical properties are + + + align:start position:0% +that the electrical properties are +essentially those as from the impur. So + + align:start position:0% +essentially those as from the impur. So + + + align:start position:0% +essentially those as from the impur. So +we send this to zero and we say that + + align:start position:0% +we send this to zero and we say that + + + align:start position:0% +we send this to zero and we say that +such a material exhibits extrinsic + + align:start position:0% +such a material exhibits extrinsic + + + align:start position:0% +such a material exhibits extrinsic +behavior. Exttrinsic + + align:start position:0% +behavior. Exttrinsic + + + align:start position:0% +behavior. Exttrinsic +behavior. Why is it extrinsic? Because + + align:start position:0% +behavior. Why is it extrinsic? Because + + + align:start position:0% +behavior. Why is it extrinsic? Because +the behavior of the the electrical + + align:start position:0% +the behavior of the the electrical + + + align:start position:0% +the behavior of the the electrical +behavior of the silicon is governed by + + align:start position:0% +behavior of the silicon is governed by + + + align:start position:0% +behavior of the silicon is governed by +the impurities that we introduced into + + align:start position:0% +the impurities that we introduced into + + + align:start position:0% +the impurities that we introduced into +the silicon. Okay, extrinsic behavior + + align:start position:0% +the silicon. Okay, extrinsic behavior + + + align:start position:0% +the silicon. Okay, extrinsic behavior +and it is imp or let's call it dopant. + + align:start position:0% +and it is imp or let's call it dopant. + + + align:start position:0% +and it is imp or let's call it dopant. +I'm going to use the word dopant and + + align:start position:0% +I'm going to use the word dopant and + + + align:start position:0% +I'm going to use the word dopant and +impurity uh interchangeably. So it's + + align:start position:0% +impurity uh interchangeably. So it's + + + align:start position:0% +impurity uh interchangeably. So it's +dopant + + align:start position:0% +dopant + + + align:start position:0% +dopant +dependent and this of course depends on + + align:start position:0% +dependent and this of course depends on + + + align:start position:0% +dependent and this of course depends on +how much we put in but the typical + + align:start position:0% +how much we put in but the typical + + + align:start position:0% +how much we put in but the typical +levels that we put in are great enough + + align:start position:0% +levels that we put in are great enough + + + align:start position:0% +levels that we put in are great enough +that they swamp the value that you get + + align:start position:0% +that they swamp the value that you get + + + align:start position:0% +that they swamp the value that you get +from thermal excitation. So in doped + + align:start position:0% +from thermal excitation. So in doped + + + align:start position:0% +from thermal excitation. So in doped +silicon you neglect thermal excitation + + align:start position:0% +silicon you neglect thermal excitation + + + align:start position:0% +silicon you neglect thermal excitation +and you calculate the carrier population + + align:start position:0% +and you calculate the carrier population + + + align:start position:0% +and you calculate the carrier population +in the conduction band based on how much + + align:start position:0% +in the conduction band based on how much + + + align:start position:0% +in the conduction band based on how much +phosphorus you put in. Every phosphorus + + align:start position:0% +phosphorus you put in. Every phosphorus + + + align:start position:0% +phosphorus you put in. Every phosphorus +gives you a a contribution. And just to + + align:start position:0% +gives you a a contribution. And just to + + + align:start position:0% +gives you a a contribution. And just to +just to complete the definition uh the + + align:start position:0% +just to complete the definition uh the + + + align:start position:0% +just to complete the definition uh the +the undoped material the undoped that is + + align:start position:0% +the undoped material the undoped that is + + + align:start position:0% +the undoped material the undoped that is +to say highly pure silicon exhibits + + align:start position:0% +to say highly pure silicon exhibits + + + align:start position:0% +to say highly pure silicon exhibits +intrinsic behavior. In other words, it + + align:start position:0% +intrinsic behavior. In other words, it + + + align:start position:0% +intrinsic behavior. In other words, it +behaves as pure silicon should behave. + + align:start position:0% +behaves as pure silicon should behave. + + + align:start position:0% +behaves as pure silicon should behave. +So an + + align:start position:0% +So an + + + align:start position:0% +So an +intrinsic semiconductor is one that has + + align:start position:0% +intrinsic semiconductor is one that has + + + align:start position:0% +intrinsic semiconductor is one that has +impur levels so low that they don't + + align:start position:0% +impur levels so low that they don't + + + align:start position:0% +impur levels so low that they don't +manifest themselves. An exttrinsic + + align:start position:0% +manifest themselves. An exttrinsic + + + align:start position:0% +manifest themselves. An exttrinsic +semiconductor has impur levels high + + align:start position:0% +semiconductor has impur levels high + + + align:start position:0% +semiconductor has impur levels high +enough that we can perceive the action + + align:start position:0% +enough that we can perceive the action + + + align:start position:0% +enough that we can perceive the action +of those impur + + align:start position:0% +of those impur + + + align:start position:0% +of those impur +levels. So we can say in this material + + align:start position:0% +levels. So we can say in this material + + + align:start position:0% +levels. So we can say in this material +that that n that are generated from the + + align:start position:0% +that that n that are generated from the + + + align:start position:0% +that that n that are generated from the +impurity or the dopen are greater by far + + align:start position:0% +impurity or the dopen are greater by far + + + align:start position:0% +impurity or the dopen are greater by far +than the n from the from the host + + align:start position:0% +than the n from the from the host + + + align:start position:0% +than the n from the from the host +material itself or if you like the + + align:start position:0% +material itself or if you like the + + + align:start position:0% +material itself or if you like the +number of electrons from the the dopant + + align:start position:0% +number of electrons from the the dopant + + + align:start position:0% +number of electrons from the the dopant +are much greater than the number of + + align:start position:0% +are much greater than the number of + + + align:start position:0% +are much greater than the number of +electrons from thermal excitation. + + align:start position:0% +electrons from thermal excitation. + + + align:start position:0% +electrons from thermal excitation. +It all comes out to say then + + align:start position:0% +It all comes out to say then + + + align:start position:0% +It all comes out to say then +that the number of electrons that are up + + align:start position:0% +that the number of electrons that are up + + + align:start position:0% +that the number of electrons that are up +in the conduction band are much greater + + align:start position:0% +in the conduction band are much greater + + + align:start position:0% +in the conduction band are much greater +than the number of holes in the veilance + + align:start position:0% +than the number of holes in the veilance + + + align:start position:0% +than the number of holes in the veilance +band because if the impurity levels are + + align:start position:0% +band because if the impurity levels are + + + align:start position:0% +band because if the impurity levels are +dominating what comes out of the host + + align:start position:0% +dominating what comes out of the host + + + align:start position:0% +dominating what comes out of the host +then that means if there's hardly any of + + align:start position:0% +then that means if there's hardly any of + + + align:start position:0% +then that means if there's hardly any of +the electrons that came from thermal + + align:start position:0% +the electrons that came from thermal + + + align:start position:0% +the electrons that came from thermal +excitation there's hardly any holes. So + + align:start position:0% +excitation there's hardly any holes. So + + + align:start position:0% +excitation there's hardly any holes. So +now the number of electrons far exceeds + + align:start position:0% +now the number of electrons far exceeds + + + align:start position:0% +now the number of electrons far exceeds +the number of holes. So this material is + + align:start position:0% +the number of holes. So this material is + + + align:start position:0% +the number of holes. So this material is +not net neutral. We do not say that n + + align:start position:0% +not net neutral. We do not say that n + + + align:start position:0% +not net neutral. We do not say that n +equals p because the number of electrons + + align:start position:0% +equals p because the number of electrons + + + align:start position:0% +equals p because the number of electrons +in conduction band is far greater than + + align:start position:0% +in conduction band is far greater than + + + align:start position:0% +in conduction band is far greater than +the number of holes. And so we call this + + align:start position:0% +the number of holes. And so we call this + + + align:start position:0% +the number of holes. And so we call this +material it's extrinsic and electrical + + align:start position:0% +material it's extrinsic and electrical + + + align:start position:0% +material it's extrinsic and electrical +engineers refer to the type of carrier + + align:start position:0% +engineers refer to the type of carrier + + + align:start position:0% +engineers refer to the type of carrier +that's dominating its electrons and + + align:start position:0% +that's dominating its electrons and + + + align:start position:0% +that's dominating its electrons and +electrons when I went to school were + + align:start position:0% +electrons when I went to school were + + + align:start position:0% +electrons when I went to school were +negative. So this is an end type + + align:start position:0% +negative. So this is an end type + + + align:start position:0% +negative. So this is an end type +semiconductor exttrinsic end type. So we + + align:start position:0% +semiconductor exttrinsic end type. So we + + + align:start position:0% +semiconductor exttrinsic end type. So we +altered the electrical properties of + + align:start position:0% +altered the electrical properties of + + + align:start position:0% +altered the electrical properties of +silicon by introducing high level of + + align:start position:0% +silicon by introducing high level of + + + align:start position:0% +silicon by introducing high level of +supervalent supervalent in other words + + align:start position:0% +supervalent supervalent in other words + + + align:start position:0% +supervalent supervalent in other words +phosphorus five is greater than four. So + + align:start position:0% +phosphorus five is greater than four. So + + + align:start position:0% +phosphorus five is greater than four. So +supervalent + + align:start position:0% +supervalent + + + align:start position:0% +supervalent +dopant supervalent dopant leads to end + + align:start position:0% +dopant supervalent dopant leads to end + + + align:start position:0% +dopant supervalent dopant leads to end +type n type + + align:start position:0% + + + + align:start position:0% + +semiconduction and now we can do it all + + align:start position:0% +semiconduction and now we can do it all + + + align:start position:0% +semiconduction and now we can do it all +over again. We do it all over again. + + align:start position:0% +over again. We do it all over again. + + + align:start position:0% +over again. We do it all over again. +What what can we do? Well, repeat + + align:start position:0% +What what can we do? Well, repeat + + + align:start position:0% +What what can we do? Well, repeat +with and I'm not going to drag you + + align:start position:0% +with and I'm not going to drag you + + + align:start position:0% +with and I'm not going to drag you +through it. This is something you can do + + align:start position:0% +through it. This is something you can do + + + align:start position:0% +through it. This is something you can do +at at home or uh wherever you'd like to + + align:start position:0% +at at home or uh wherever you'd like to + + + align:start position:0% +at at home or uh wherever you'd like to +work. Repeat with subvealent + + align:start position:0% +work. Repeat with subvealent + + + align:start position:0% +work. Repeat with subvealent +impurity. Repeat with subvealent + + align:start position:0% +impurity. Repeat with subvealent + + + align:start position:0% +impurity. Repeat with subvealent +impurity or subvvealent + + align:start position:0% +impurity or subvvealent + + + align:start position:0% +impurity or subvvealent +dopan. So for example, + + align:start position:0% +dopan. So for example, + + + align:start position:0% +dopan. So for example, +boron. What would happen if we were to + + align:start position:0% +boron. What would happen if we were to + + + align:start position:0% +boron. What would happen if we were to +introduce boron here? So boron goes into + + align:start position:0% +introduce boron here? So boron goes into + + + align:start position:0% +introduce boron here? So boron goes into +the space and it substitutes. But boron + + align:start position:0% +the space and it substitutes. But boron + + + align:start position:0% +the space and it substitutes. But boron +is group 13 or group three. So boron + + align:start position:0% +is group 13 or group three. So boron + + + align:start position:0% +is group 13 or group three. So boron +only has three veence electrons. So it + + align:start position:0% +only has three veence electrons. So it + + + align:start position:0% +only has three veence electrons. So it +fills one two three. And boron is + + align:start position:0% +fills one two three. And boron is + + + align:start position:0% +fills one two three. And boron is +electropositive. It's sitting there. It + + align:start position:0% +electropositive. It's sitting there. It + + + align:start position:0% +electropositive. It's sitting there. It +wants to form the bond. How do we how do + + align:start position:0% +wants to form the bond. How do we how do + + + align:start position:0% +wants to form the bond. How do we how do +we handle this situation? What do we do + + align:start position:0% +we handle this situation? What do we do + + + align:start position:0% +we handle this situation? What do we do +in order to balance the fact that this + + align:start position:0% +in order to balance the fact that this + + + align:start position:0% +in order to balance the fact that this +is lacking one electron? Where is the + + align:start position:0% +is lacking one electron? Where is the + + + align:start position:0% +is lacking one electron? Where is the +electron inventory in this crystal? + + align:start position:0% +electron inventory in this crystal? + + + align:start position:0% +electron inventory in this crystal? +Where's the electron store? If I go + + align:start position:0% +Where's the electron store? If I go + + + align:start position:0% +Where's the electron store? If I go +shopping for electrons, where's the only + + align:start position:0% +shopping for electrons, where's the only + + + align:start position:0% +shopping for electrons, where's the only +place I can find them? They're here. + + align:start position:0% +place I can find them? They're here. + + + align:start position:0% +place I can find them? They're here. +They're in the + + align:start position:0% +They're in the + + + align:start position:0% +They're in the +bonds. That is to say, they're in the + + align:start position:0% +bonds. That is to say, they're in the + + + align:start position:0% +bonds. That is to say, they're in the +veence band. So, what will happen is we + + align:start position:0% +veence band. So, what will happen is we + + + align:start position:0% +veence band. So, what will happen is we +will rip an electron out of the veence + + align:start position:0% +will rip an electron out of the veence + + + align:start position:0% +will rip an electron out of the veence +band and move it over to here. And when + + align:start position:0% +band and move it over to here. And when + + + align:start position:0% +band and move it over to here. And when +we do that, what happens if I take an + + align:start position:0% +we do that, what happens if I take an + + + align:start position:0% +we do that, what happens if I take an +electron out of here? What's left + + align:start position:0% +electron out of here? What's left + + + align:start position:0% +electron out of here? What's left +behind? A hole. So, let's generate a + + align:start position:0% +behind? A hole. So, let's generate a + + + align:start position:0% +behind? A hole. So, let's generate a +hole. + + align:start position:0% +hole. + + + align:start position:0% +hole. +So every time I introduce a subvealent + + align:start position:0% +So every time I introduce a subvealent + + + align:start position:0% +So every time I introduce a subvealent +impur I call for an electron out of the + + align:start position:0% +impur I call for an electron out of the + + + align:start position:0% +impur I call for an electron out of the +veence band and I generate a + + align:start position:0% +veence band and I generate a + + + align:start position:0% +veence band and I generate a +hole and where's that hole going to lie? + + align:start position:0% +hole and where's that hole going to lie? + + + align:start position:0% +hole and where's that hole going to lie? +We can go through the same analogy and + + align:start position:0% +We can go through the same analogy and + + + align:start position:0% +We can go through the same analogy and +we will find that the energy level of + + align:start position:0% +we will find that the energy level of + + + align:start position:0% +we will find that the energy level of +that hole is sitting just above the + + align:start position:0% +that hole is sitting just above the + + + align:start position:0% +that hole is sitting just above the +veilance + + align:start position:0% +veilance + + + align:start position:0% +veilance +band but the electrons are sitting in + + align:start position:0% +band but the electrons are sitting in + + + align:start position:0% +band but the electrons are sitting in +the veilance + + align:start position:0% + + + + align:start position:0% + +band. So how do I get the electrons out + + align:start position:0% +band. So how do I get the electrons out + + + align:start position:0% +band. So how do I get the electrons out +of the veilance band up into this level? + + align:start position:0% +of the veilance band up into this level? + + + align:start position:0% +of the veilance band up into this level? +Thermal excitation. And guess what this + + align:start position:0% +Thermal excitation. And guess what this + + + align:start position:0% +Thermal excitation. And guess what this +energy difference is? It's on the order + + align:start position:0% +energy difference is? It's on the order + + + align:start position:0% +energy difference is? It's on the order +of the thermal energy. And so I get + + align:start position:0% +of the thermal energy. And so I get + + + align:start position:0% +of the thermal energy. And so I get +thermal ionization of the veence + + align:start position:0% +thermal ionization of the veence + + + align:start position:0% +thermal ionization of the veence +electrons up into this level. This level + + align:start position:0% +electrons up into this level. This level + + + align:start position:0% +electrons up into this level. This level +is a place where electrons go. It + + align:start position:0% +is a place where electrons go. It + + + align:start position:0% +is a place where electrons go. It +accepts electrons. It is called the + + align:start position:0% +accepts electrons. It is called the + + + align:start position:0% +accepts electrons. It is called the +acceptor level. acceptor + + align:start position:0% + + + + align:start position:0% + +level. Acceptor + + align:start position:0% + + + + align:start position:0% + +level. So now we have this configuration + + align:start position:0% +level. So now we have this configuration + + + align:start position:0% +level. So now we have this configuration +conduction + + align:start position:0% +conduction + + + align:start position:0% +conduction +band veilance band subvvealent impurity. + + align:start position:0% +band veilance band subvvealent impurity. + + + align:start position:0% +band veilance band subvvealent impurity. +This is not to scale of course. This is + + align:start position:0% +This is not to scale of course. This is + + + align:start position:0% +This is not to scale of course. This is +on the order of 0.02 EV. Okay. And this + + align:start position:0% +on the order of 0.02 EV. Okay. And this + + + align:start position:0% +on the order of 0.02 EV. Okay. And this +is called the acceptor level. + + align:start position:0% + + + + align:start position:0% + +we get thermal excitation leaving holes + + align:start position:0% +we get thermal excitation leaving holes + + + align:start position:0% +we get thermal excitation leaving holes +behind. So thermal excitation promotes + + align:start position:0% +behind. So thermal excitation promotes + + + align:start position:0% +behind. So thermal excitation promotes +the electrons up to here and leaves + + align:start position:0% +the electrons up to here and leaves + + + align:start position:0% +the electrons up to here and leaves +behind holes. So every time I put in a a + + align:start position:0% +behind holes. So every time I put in a a + + + align:start position:0% +behind holes. So every time I put in a a +subvealent impurity the result is a + + align:start position:0% +subvealent impurity the result is a + + + align:start position:0% +subvealent impurity the result is a +hole. So I can control the whole + + align:start position:0% +hole. So I can control the whole + + + align:start position:0% +hole. So I can control the whole +population and the same thing will + + align:start position:0% +population and the same thing will + + + align:start position:0% +population and the same thing will +happen if you go through this analogy + + align:start position:0% +happen if you go through this analogy + + + align:start position:0% +happen if you go through this analogy +what will happen n will no longer equal + + align:start position:0% +what will happen n will no longer equal + + + align:start position:0% +what will happen n will no longer equal +p instead the number of positives is + + align:start position:0% +p instead the number of positives is + + + align:start position:0% +p instead the number of positives is +going to exceed the number of negatives. + + align:start position:0% +going to exceed the number of negatives. + + + align:start position:0% +going to exceed the number of negatives. +Now ne will be much less than + + align:start position:0% +Now ne will be much less than + + + align:start position:0% +Now ne will be much less than +nh will be less than p and so this + + align:start position:0% +nh will be less than p and so this + + + align:start position:0% +nh will be less than p and so this +material will be rendered a positive + + align:start position:0% +material will be rendered a positive + + + align:start position:0% +material will be rendered a positive +conductor. It's going to be dominantly + + align:start position:0% +conductor. It's going to be dominantly + + + align:start position:0% +conductor. It's going to be dominantly +whole conduction. So this is now a + + align:start position:0% +whole conduction. So this is now a + + + align:start position:0% +whole conduction. So this is now a +ptype ptype + + align:start position:0% +ptype ptype + + + align:start position:0% +ptype ptype +semiconductor extrinsic ptype + + align:start position:0% +semiconductor extrinsic ptype + + + align:start position:0% +semiconductor extrinsic ptype +semiconductor. So what's the what's the + + align:start position:0% +semiconductor. So what's the what's the + + + align:start position:0% +semiconductor. So what's the what's the +template here? Subveent + + align:start position:0% +template here? Subveent + + + align:start position:0% +template here? Subveent +dopant. Subveilent dopant calls for + + align:start position:0% +dopant. Subveilent dopant calls for + + + align:start position:0% +dopant. Subveilent dopant calls for +electrons, generates holes and makes a + + align:start position:0% + + + + align:start position:0% + +ptype + + align:start position:0% + + + + align:start position:0% + +semiconductor. That's amazing. So now I + + align:start position:0% +semiconductor. That's amazing. So now I + + + align:start position:0% +semiconductor. That's amazing. So now I +can take these I can make a sandwich out + + align:start position:0% +can take these I can make a sandwich out + + + align:start position:0% +can take these I can make a sandwich out +of these things. You know I can do this. + + align:start position:0% +of these things. You know I can do this. + + + align:start position:0% +of these things. You know I can do this. +I could say take this is all silicon. + + align:start position:0% +I could say take this is all silicon. + + + align:start position:0% +I could say take this is all silicon. +Okay. Okay, I could dope this side with + + align:start position:0% +Okay. Okay, I could dope this side with + + + align:start position:0% +Okay. Okay, I could dope this side with +phosphorus. This side with let's say + + align:start position:0% +phosphorus. This side with let's say + + + align:start position:0% +phosphorus. This side with let's say +this is phosphorus doped. The right is + + align:start position:0% +this is phosphorus doped. The right is + + + align:start position:0% +this is phosphorus doped. The right is +phosphorus doped. The left side is boron + + align:start position:0% +phosphorus doped. The left side is boron + + + align:start position:0% +phosphorus doped. The left side is boron +doped. So that means that the left side + + align:start position:0% +doped. So that means that the left side + + + align:start position:0% +doped. So that means that the left side +will be P type. The right side will be N + + align:start position:0% +will be P type. The right side will be N + + + align:start position:0% +will be P type. The right side will be N +type. And what do I have here? I have a + + align:start position:0% +type. And what do I have here? I have a + + + align:start position:0% +type. And what do I have here? I have a +PN + + align:start position:0% +PN + + + align:start position:0% +PN +junction. I have a solid state + + align:start position:0% +junction. I have a solid state + + + align:start position:0% +junction. I have a solid state +rectifier. If I put an AC signal in + + align:start position:0% +rectifier. If I put an AC signal in + + + align:start position:0% +rectifier. If I put an AC signal in +here, I get + + align:start position:0% +here, I get + + + align:start position:0% +here, I get +rectification. Solid state. This is the + + align:start position:0% +rectification. Solid state. This is the + + + align:start position:0% +rectification. Solid state. This is the +solid + + align:start position:0% +solid + + + align:start position:0% +solid +state. It's fantastic. Well, you know, + + align:start position:0% +state. It's fantastic. Well, you know, + + + align:start position:0% +state. It's fantastic. Well, you know, +I've been talking about elemental + + align:start position:0% +I've been talking about elemental + + + align:start position:0% +I've been talking about elemental +semiconductors, but uh these are found + + align:start position:0% +semiconductors, but uh these are found + + + align:start position:0% +semiconductors, but uh these are found +not only in uh elements. Oh, this is + + align:start position:0% +not only in uh elements. Oh, this is + + + align:start position:0% +not only in uh elements. Oh, this is +just left over from last day. We saw + + align:start position:0% +just left over from last day. We saw + + + align:start position:0% +just left over from last day. We saw +this last day. + + align:start position:0% +this last day. + + + align:start position:0% +this last day. +Um you can have compounds that are + + align:start position:0% +Um you can have compounds that are + + + align:start position:0% +Um you can have compounds that are +semiconductors. So, so far we talked + + align:start position:0% +semiconductors. So, so far we talked + + + align:start position:0% +semiconductors. So, so far we talked +about just group four. We talked about + + align:start position:0% +about just group four. We talked about + + + align:start position:0% +about just group four. We talked about +silicon and germanmanium. Tin is very + + align:start position:0% +silicon and germanmanium. Tin is very + + + align:start position:0% +silicon and germanmanium. Tin is very +very mildly semiconducting, but these + + align:start position:0% +very mildly semiconducting, but these + + + align:start position:0% +very mildly semiconducting, but these +are the two workh horses. And in fact + + align:start position:0% +are the two workh horses. And in fact + + + align:start position:0% +are the two workh horses. And in fact +it's dominantly silicon. But now look at + + align:start position:0% +it's dominantly silicon. But now look at + + + align:start position:0% +it's dominantly silicon. But now look at +you can take group three and group five + + align:start position:0% +you can take group three and group five + + + align:start position:0% +you can take group three and group five +and you'll make covealent compounds and + + align:start position:0% +and you'll make covealent compounds and + + + align:start position:0% +and you'll make covealent compounds and +they too have band gaps on this + + align:start position:0% +they too have band gaps on this + + + align:start position:0% +they too have band gaps on this +interval. So we have an entire pallet + + align:start position:0% +interval. So we have an entire pallet + + + align:start position:0% +interval. So we have an entire pallet +here that we can paint on. So for + + align:start position:0% +here that we can paint on. So for + + + align:start position:0% +here that we can paint on. So for +example let's look at this homologous + + align:start position:0% +example let's look at this homologous + + + align:start position:0% +example let's look at this homologous +series with aluminum. Aluminum antimide + + align:start position:0% +series with aluminum. Aluminum antimide + + + align:start position:0% +series with aluminum. Aluminum antimide +1.52 electron volts band gap. Aluminum + + align:start position:0% +1.52 electron volts band gap. Aluminum + + + align:start position:0% +1.52 electron volts band gap. Aluminum +nitride 6.3. Aluminum nitrite is an + + align:start position:0% +nitride 6.3. Aluminum nitrite is an + + + align:start position:0% +nitride 6.3. Aluminum nitrite is an +insulator. It's very strong material. We + + align:start position:0% +insulator. It's very strong material. We + + + align:start position:0% +insulator. It's very strong material. We +use it in in my lab as a uh for as a + + align:start position:0% +use it in in my lab as a uh for as a + + + align:start position:0% +use it in in my lab as a uh for as a +refractory. It resists high temperature + + align:start position:0% +refractory. It resists high temperature + + + align:start position:0% +refractory. It resists high temperature +corrosion. Now what's going on? The + + align:start position:0% +corrosion. Now what's going on? The + + + align:start position:0% +corrosion. Now what's going on? The +difference in electro negativity. These + + align:start position:0% +difference in electro negativity. These + + + align:start position:0% +difference in electro negativity. These +are covealent bonds. Greater difference + + align:start position:0% +are covealent bonds. Greater difference + + + align:start position:0% +are covealent bonds. Greater difference +in electro negativity, higher bond + + align:start position:0% +in electro negativity, higher bond + + + align:start position:0% +in electro negativity, higher bond +energy. And that occurs in all of these + + align:start position:0% +energy. And that occurs in all of these + + + align:start position:0% +energy. And that occurs in all of these +columns as you go up. So an increase in + + align:start position:0% +columns as you go up. So an increase in + + + align:start position:0% +columns as you go up. So an increase in +electro negativity difference is an + + align:start position:0% +electro negativity difference is an + + + align:start position:0% +electro negativity difference is an +increase in bond strength. And an + + align:start position:0% +increase in bond strength. And an + + + align:start position:0% +increase in bond strength. And an +increase in bond strength means an + + align:start position:0% +increase in bond strength means an + + + align:start position:0% +increase in bond strength means an +increase in band gap + + align:start position:0% +increase in band gap + + + align:start position:0% +increase in band gap +energy. And some of these are really + + align:start position:0% +energy. And some of these are really + + + align:start position:0% +energy. And some of these are really +interesting. Indium antimonide has a + + align:start position:0% +interesting. Indium antimonide has a + + + align:start position:0% +interesting. Indium antimonide has a +band gap of about 2/10 of an electron + + align:start position:0% +band gap of about 2/10 of an electron + + + align:start position:0% +band gap of about 2/10 of an electron +volt which means that its absorption + + align:start position:0% +volt which means that its absorption + + + align:start position:0% +volt which means that its absorption +edge its absorption edge is 7 * 10 the + + align:start position:0% +edge its absorption edge is 7 * 10 the + + + align:start position:0% +edge its absorption edge is 7 * 10 the +minus 6 7 micrometers which puts it in + + align:start position:0% +minus 6 7 micrometers which puts it in + + + align:start position:0% +minus 6 7 micrometers which puts it in +the IR and this is one of the materials + + align:start position:0% +the IR and this is one of the materials + + + align:start position:0% +the IR and this is one of the materials +that would be used as a sensor for night + + align:start position:0% +that would be used as a sensor for night + + + align:start position:0% +that would be used as a sensor for night +vision because what are you really + + align:start position:0% +vision because what are you really + + + align:start position:0% +vision because what are you really +sensing when you're looking at night + + align:start position:0% +sensing when you're looking at night + + + align:start position:0% +sensing when you're looking at night +you're sensing heat you don't see the + + align:start position:0% +you're sensing heat you don't see the + + + align:start position:0% +you're sensing heat you don't see the +human body you see the heat coming from + + align:start position:0% +human body you see the heat coming from + + + align:start position:0% +human body you see the heat coming from +the human body right so if everything's + + align:start position:0% +the human body right so if everything's + + + align:start position:0% +the human body right so if everything's +cold And there's no delta T. You don't + + align:start position:0% +cold And there's no delta T. You don't + + + align:start position:0% +cold And there's no delta T. You don't +see anything over here. Cadmium sulfide. + + align:start position:0% +see anything over here. Cadmium sulfide. + + + align:start position:0% +see anything over here. Cadmium sulfide. +Cadmium sulfide is 5 * 10us 7. That's + + align:start position:0% +Cadmium sulfide is 5 * 10us 7. That's + + + align:start position:0% +Cadmium sulfide is 5 * 10us 7. That's +right smack dab in the middle of the + + align:start position:0% +right smack dab in the middle of the + + + align:start position:0% +right smack dab in the middle of the +visible. When I was a child, my father + + align:start position:0% +visible. When I was a child, my father + + + align:start position:0% +visible. When I was a child, my father +had a 35mm camera. It had a cadmium + + align:start position:0% +had a 35mm camera. It had a cadmium + + + align:start position:0% +had a 35mm camera. It had a cadmium +sulfide light meter. And we would match + + align:start position:0% +sulfide light meter. And we would match + + + align:start position:0% +sulfide light meter. And we would match +the needle with the um incoming + + align:start position:0% +the needle with the um incoming + + + align:start position:0% +the needle with the um incoming +radiation and cadmium sulfide. Well, I + + align:start position:0% +radiation and cadmium sulfide. Well, I + + + align:start position:0% +radiation and cadmium sulfide. Well, I +never never understood why it was + + align:start position:0% +never never understood why it was + + + align:start position:0% +never never understood why it was +cadmium sulfide until I understood band + + align:start position:0% +cadmium sulfide until I understood band + + + align:start position:0% +cadmium sulfide until I understood band +gap. And obviously there it is. You can + + align:start position:0% +gap. And obviously there it is. You can + + + align:start position:0% +gap. And obviously there it is. You can +also think about what happens what + + align:start position:0% +also think about what happens what + + + align:start position:0% +also think about what happens what +happens if you're photographing + + align:start position:0% +happens if you're photographing + + + align:start position:0% +happens if you're photographing +something that's that's dominantly red + + align:start position:0% +something that's that's dominantly red + + + align:start position:0% +something that's that's dominantly red +and your um light meter is parked in the + + align:start position:0% +and your um light meter is parked in the + + + align:start position:0% +and your um light meter is parked in the +middle of the yellow. You wonder why + + align:start position:0% +middle of the yellow. You wonder why + + + align:start position:0% +middle of the yellow. You wonder why +your photographs are + + align:start position:0% +your photographs are + + + align:start position:0% +your photographs are +overexposed. Think about that sometime. + + align:start position:0% +overexposed. Think about that sometime. + + + align:start position:0% +overexposed. Think about that sometime. +Oh, so now last thing I want to tell you + + align:start position:0% +Oh, so now last thing I want to tell you + + + align:start position:0% +Oh, so now last thing I want to tell you +is that um that not only do you have uh + + align:start position:0% +is that um that not only do you have uh + + + align:start position:0% +is that um that not only do you have uh +solid semiconductors, you have liquid + + align:start position:0% +solid semiconductors, you have liquid + + + align:start position:0% +solid semiconductors, you have liquid +semiconductors. And when silicon melts, + + align:start position:0% +semiconductors. And when silicon melts, + + + align:start position:0% +semiconductors. And when silicon melts, +it's not a semiconductor. silicon melts, + + align:start position:0% +it's not a semiconductor. silicon melts, + + + align:start position:0% +it's not a semiconductor. silicon melts, +the band gap collapses and molten + + align:start position:0% +the band gap collapses and molten + + + align:start position:0% +the band gap collapses and molten +silicon behaves as a liquid metal. But + + align:start position:0% +silicon behaves as a liquid metal. But + + + align:start position:0% +silicon behaves as a liquid metal. But +for example, something like cadmium + + align:start position:0% +for example, something like cadmium + + + align:start position:0% +for example, something like cadmium +teluride which is uh useful in night + + align:start position:0% +teluride which is uh useful in night + + + align:start position:0% +teluride which is uh useful in night +vision. Cadmium telleluride as a solid + + align:start position:0% +vision. Cadmium telleluride as a solid + + + align:start position:0% +vision. Cadmium telleluride as a solid +has a band gap on the order of + + align:start position:0% +has a band gap on the order of + + + align:start position:0% +has a band gap on the order of +1.45 electron volts. As a liquid, it + + align:start position:0% +1.45 electron volts. As a liquid, it + + + align:start position:0% +1.45 electron volts. As a liquid, it +still has a band gap. It's about 0.3 + + align:start position:0% +still has a band gap. It's about 0.3 + + + align:start position:0% +still has a band gap. It's about 0.3 +electron volts. So it is uh parked down + + align:start position:0% +electron volts. So it is uh parked down + + + align:start position:0% +electron volts. So it is uh parked down +in the infrared. + + align:start position:0% +in the infrared. + + + align:start position:0% +in the infrared. +And the transition metal oxides also do + + align:start position:0% +And the transition metal oxides also do + + + align:start position:0% +And the transition metal oxides also do +this. Trans titania liquid titania is + + align:start position:0% +this. Trans titania liquid titania is + + + align:start position:0% +this. Trans titania liquid titania is +dominantly an electronic conductor, not + + align:start position:0% +dominantly an electronic conductor, not + + + align:start position:0% +dominantly an electronic conductor, not +an ionic conductor because its band gap + + align:start position:0% +an ionic conductor because its band gap + + + align:start position:0% +an ionic conductor because its band gap +is parked there. And this is of interest + + align:start position:0% +is parked there. And this is of interest + + + align:start position:0% +is parked there. And this is of interest +to some of the work in my lab where + + align:start position:0% +to some of the work in my lab where + + + align:start position:0% +to some of the work in my lab where +we're looking at trying to set the stage + + align:start position:0% +we're looking at trying to set the stage + + + align:start position:0% +we're looking at trying to set the stage +for lunar colonization where you want to + + align:start position:0% +for lunar colonization where you want to + + + align:start position:0% +for lunar colonization where you want to +get oxygen out of the moon. The surface + + align:start position:0% +get oxygen out of the moon. The surface + + + align:start position:0% +get oxygen out of the moon. The surface +of the moon. The surface of the moon is + + align:start position:0% +of the moon. The surface of the moon is + + + align:start position:0% +of the moon. The surface of the moon is +not made of green cheese. I'm sorry to + + align:start position:0% +not made of green cheese. I'm sorry to + + + align:start position:0% +not made of green cheese. I'm sorry to +tell you. It's made dominantly of iron + + align:start position:0% +tell you. It's made dominantly of iron + + + align:start position:0% +tell you. It's made dominantly of iron +oxide and titanium oxide. That's why + + align:start position:0% +oxide and titanium oxide. That's why + + + align:start position:0% +oxide and titanium oxide. That's why +it's so brilliantly white. It's titania. + + align:start position:0% +it's so brilliantly white. It's titania. + + + align:start position:0% +it's so brilliantly white. It's titania. +So, it's 50% oxygen but tightly bound. + + align:start position:0% +So, it's 50% oxygen but tightly bound. + + + align:start position:0% +So, it's 50% oxygen but tightly bound. +And if you want to electrolyze the moon, + + align:start position:0% +And if you want to electrolyze the moon, + + + align:start position:0% +And if you want to electrolyze the moon, +you have to somehow repress this liquid + + align:start position:0% +you have to somehow repress this liquid + + + align:start position:0% +you have to somehow repress this liquid +semiconduction. So, that's a topic of + + align:start position:0% +semiconduction. So, that's a topic of + + + align:start position:0% +semiconduction. So, that's a topic of +research. So, this is probably a uh a + + align:start position:0% +research. So, this is probably a uh a + + + align:start position:0% +research. So, this is probably a uh a +good place to stay. And what we're going + + align:start position:0% +good place to stay. And what we're going + + + align:start position:0% +good place to stay. And what we're going +to do next day is we're going to start + + align:start position:0% +to do next day is we're going to start + + + align:start position:0% +to do next day is we're going to start +onto the um treatment of uh solids and + + align:start position:0% +onto the um treatment of uh solids and + + + align:start position:0% +onto the um treatment of uh solids and +crystal. But I don't want a lot of + + align:start position:0% +crystal. But I don't want a lot of + + + align:start position:0% +crystal. But I don't want a lot of +moving. It's 11:47. We still have a few + + align:start position:0% +moving. It's 11:47. We still have a few + + + align:start position:0% +moving. It's 11:47. We still have a few +minutes. So um let's see what do we want + + align:start position:0% +minutes. So um let's see what do we want + + + align:start position:0% +minutes. So um let's see what do we want +to talk about. We'll move past this. + + align:start position:0% +to talk about. We'll move past this. + + + align:start position:0% +to talk about. We'll move past this. +We'll get to this next day. And uh what + + align:start position:0% +We'll get to this next day. And uh what + + + align:start position:0% +We'll get to this next day. And uh what +I wanted to talk about today was this + + align:start position:0% +I wanted to talk about today was this + + + align:start position:0% +I wanted to talk about today was this +image here. This image is an image of + + align:start position:0% +image here. This image is an image of + + + align:start position:0% +image here. This image is an image of +the first + + align:start position:0% +the first + + + align:start position:0% +the first +um diode rectifying solid state diode. + + align:start position:0% +um diode rectifying solid state diode. + + + align:start position:0% +um diode rectifying solid state diode. +This was uh done at Bell Labs in Murray + + align:start position:0% +This was uh done at Bell Labs in Murray + + + align:start position:0% +This was uh done at Bell Labs in Murray +Hill, New Jersey in uh December of + + align:start position:0% +Hill, New Jersey in uh December of + + + align:start position:0% +Hill, New Jersey in uh December of +1947. So what you're looking at here is + + align:start position:0% +1947. So what you're looking at here is + + + align:start position:0% +1947. So what you're looking at here is +a piece of single crystal germanmanium. + + align:start position:0% +a piece of single crystal germanmanium. + + + align:start position:0% +a piece of single crystal germanmanium. +Single crystal germanmanium and uh the + + align:start position:0% +Single crystal germanmanium and uh the + + + align:start position:0% +Single crystal germanmanium and uh the +various leads and so on. And this uh was + + align:start position:0% +various leads and so on. And this uh was + + + align:start position:0% +various leads and so on. And this uh was +able to uh perform the the uh the + + align:start position:0% +able to uh perform the the uh the + + + align:start position:0% +able to uh perform the the uh the +function of a of a diode. Now, if I told + + align:start position:0% +function of a of a diode. Now, if I told + + + align:start position:0% +function of a of a diode. Now, if I told +you that someday there would + + align:start position:0% +you that someday there would + + + align:start position:0% +you that someday there would +be 16 million of those on the uh on a a + + align:start position:0% +be 16 million of those on the uh on a a + + + align:start position:0% +be 16 million of those on the uh on a a +piece of real estate about the size of + + align:start position:0% +piece of real estate about the size of + + + align:start position:0% +piece of real estate about the size of +your fingernail, you would say that I + + align:start position:0% +your fingernail, you would say that I + + + align:start position:0% +your fingernail, you would say that I +was crazy. All right. And so what's + + align:start position:0% +was crazy. All right. And so what's + + + align:start position:0% +was crazy. All right. And so what's +happened from that day to this date? Uh + + align:start position:0% +happened from that day to this date? Uh + + + align:start position:0% +happened from that day to this date? Uh +Tom, do you think I could get the + + align:start position:0% +Tom, do you think I could get the + + + align:start position:0% +Tom, do you think I could get the +document camera on, please? So, I'm I'm + + align:start position:0% +document camera on, please? So, I'm I'm + + + align:start position:0% +document camera on, please? So, I'm I'm +going to show you where we've gone. This + + align:start position:0% +going to show you where we've gone. This + + + align:start position:0% +going to show you where we've gone. This +is now this is uh uh let's see I want to + + align:start position:0% +is now this is uh uh let's see I want to + + + align:start position:0% +is now this is uh uh let's see I want to +go to is this oh look at + + align:start position:0% +go to is this oh look at + + + align:start position:0% +go to is this oh look at +this. So let's look at + + align:start position:0% +this. So let's look at + + + align:start position:0% +this. So let's look at +Pentium. Here's Pentium. And then okay + + align:start position:0% +Pentium. Here's Pentium. And then okay + + + align:start position:0% +Pentium. Here's Pentium. And then okay +so we've got we've got a gazillion of + + align:start position:0% +so we've got we've got a gazillion of + + + align:start position:0% +so we've got we've got a gazillion of +these things underneath the gold here. + + align:start position:0% +these things underneath the gold here. + + + align:start position:0% +these things underneath the gold here. +This is everything's covered in gold + + align:start position:0% +This is everything's covered in gold + + + align:start position:0% +This is everything's covered in gold +because um electrical engineers are very + + align:start position:0% +because um electrical engineers are very + + + align:start position:0% +because um electrical engineers are very +superstitious. They they get nervous + + align:start position:0% +superstitious. They they get nervous + + + align:start position:0% +superstitious. They they get nervous +exposing wires. So they played + + align:start position:0% +exposing wires. So they played + + + align:start position:0% +exposing wires. So they played +everything with gold because they heard + + align:start position:0% +everything with gold because they heard + + + align:start position:0% +everything with gold because they heard +somewhere that gold is chemically inert. + + align:start position:0% +somewhere that gold is chemically inert. + + + align:start position:0% +somewhere that gold is chemically inert. +So underneath there is well here you can + + align:start position:0% +So underneath there is well here you can + + + align:start position:0% +So underneath there is well here you can +see that there's the there's the unit. + + align:start position:0% +see that there's the there's the unit. + + + align:start position:0% +see that there's the there's the unit. +So it's sitting there. So all of this + + align:start position:0% +So it's sitting there. So all of this + + + align:start position:0% +So it's sitting there. So all of this +and here's the suspension. All of this + + align:start position:0% +and here's the suspension. All of this + + + align:start position:0% +and here's the suspension. All of this +spider spiderweb is is being able to + + align:start position:0% +spider spiderweb is is being able to + + + align:start position:0% +spider spiderweb is is being able to +address all of the various devices. So + + align:start position:0% +address all of the various devices. So + + + align:start position:0% +address all of the various devices. So +it started with that first one and + + align:start position:0% +it started with that first one and + + + align:start position:0% +it started with that first one and +here's the sort of the intermediate. + + align:start position:0% +here's the sort of the intermediate. + + + align:start position:0% +here's the sort of the intermediate. +This is taking the silicon that I showed + + align:start position:0% +This is taking the silicon that I showed + + + align:start position:0% +This is taking the silicon that I showed +you last day. And now + + align:start position:0% +you last day. And now + + + align:start position:0% +you last day. And now +uh let's go as big. + + align:start position:0% +uh let's go as big. + + + align:start position:0% +uh let's go as big. +See? So these are now these are + + align:start position:0% +See? So these are now these are + + + align:start position:0% +See? So these are now these are +individual devices that have been put on + + align:start position:0% +individual devices that have been put on + + + align:start position:0% +individual devices that have been put on +the silicon through uh + + align:start position:0% +the silicon through uh + + + align:start position:0% +the silicon through uh +photoiththography. So what are we doing? + + align:start position:0% +photoiththography. So what are we doing? + + + align:start position:0% +photoiththography. So what are we doing? +What we're doing is we're making masks + + align:start position:0% +What we're doing is we're making masks + + + align:start position:0% +What we're doing is we're making masks +and we're conducting these doping + + align:start position:0% +and we're conducting these doping + + + align:start position:0% +and we're conducting these doping +operations to set up the various uh + + align:start position:0% +operations to set up the various uh + + + align:start position:0% +operations to set up the various uh +devices and we can make many of them and + + align:start position:0% +devices and we can make many of them and + + + align:start position:0% +devices and we can make many of them and +then break them up and then eventually + + align:start position:0% +then break them up and then eventually + + + align:start position:0% +then break them up and then eventually +put them into something like this and so + + align:start position:0% +put them into something like this and so + + + align:start position:0% +put them into something like this and so +on. So that's the that's the result of a + + align:start position:0% +on. So that's the that's the result of a + + + align:start position:0% +on. So that's the that's the result of a +of a long of a long history of + + align:start position:0% +of a long of a long history of + + + align:start position:0% +of a long of a long history of +understanding the the processing of + + align:start position:0% +understanding the the processing of + + + align:start position:0% +understanding the the processing of +devices based upon the chemistry that + + align:start position:0% +devices based upon the chemistry that + + + align:start position:0% +devices based upon the chemistry that +started with what what started all of + + align:start position:0% +started with what what started all of + + + align:start position:0% +started with what what started all of +this. The search for octet stability. + + align:start position:0% +this. The search for octet stability. + + + align:start position:0% +this. The search for octet stability. +Never forget that. That's what started + + align:start position:0% +Never forget that. That's what started + + + align:start position:0% +Never forget that. That's what started +this. The search for octet stability. + + align:start position:0% +this. The search for octet stability. + + + align:start position:0% +this. The search for octet stability. +Okay, we'll see you on Friday. \ No newline at end of file diff --git a/vpJba2qIXjs.txt b/vpJba2qIXjs.txt new file mode 100644 index 0000000000000000000000000000000000000000..5c04ddb725552f16e6c00aa6da25fa3a9ded5109 --- /dev/null +++ b/vpJba2qIXjs.txt @@ -0,0 +1,12539 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +I'd like to in this evening lecture what + + align:start position:0% +I'd like to in this evening lecture what + + + align:start position:0% +I'd like to in this evening lecture what +I'd like to do is continue a bit to + + align:start position:0% +I'd like to do is continue a bit to + + + align:start position:0% +I'd like to do is continue a bit to +expand on and complicate and maybe also + + align:start position:0% +expand on and complicate and maybe also + + + align:start position:0% +expand on and complicate and maybe also +deepen this idea I've been suggesting to + + align:start position:0% +deepen this idea I've been suggesting to + + + align:start position:0% +deepen this idea I've been suggesting to +you that I'm labeling the Fred principle + + align:start position:0% +you that I'm labeling the Fred principle + + + align:start position:0% +you that I'm labeling the Fred principle +really a shorthand way of describing the + + align:start position:0% +really a shorthand way of describing the + + + align:start position:0% +really a shorthand way of describing the +immensely complex and from an + + align:start position:0% +immensely complex and from an + + + align:start position:0% +immensely complex and from an +intellectual standpoint a historical + + align:start position:0% +intellectual standpoint a historical + + + align:start position:0% +intellectual standpoint a historical +standpoint immensely exciting and + + align:start position:0% +standpoint immensely exciting and + + + align:start position:0% +standpoint immensely exciting and +astonishing process whereby film went in + + align:start position:0% +astonishing process whereby film went in + + + align:start position:0% +astonishing process whereby film went in +an in an incredibly ly short time from + + align:start position:0% +an in an incredibly ly short time from + + + align:start position:0% +an in an incredibly ly short time from +being a mere novelty to being an + + align:start position:0% +being a mere novelty to being an + + + align:start position:0% +being a mere novelty to being an +embedded social formation in the United + + align:start position:0% +embedded social formation in the United + + + align:start position:0% +embedded social formation in the United +States and and in other industrialized + + align:start position:0% +States and and in other industrialized + + + align:start position:0% +States and and in other industrialized +societies and not just only a so + + align:start position:0% +societies and not just only a so + + + align:start position:0% +societies and not just only a so +embedded social formation becoming by + + align:start position:0% +embedded social formation becoming by + + + align:start position:0% +embedded social formation becoming by +the end of the 1920s one of the central + + align:start position:0% +the end of the 1920s one of the central + + + align:start position:0% +the end of the 1920s one of the central +media for the expression of art and an + + align:start position:0% +media for the expression of art and an + + + align:start position:0% +media for the expression of art and an +artistic medium so that it went from + + align:start position:0% +artistic medium so that it went from + + + align:start position:0% +artistic medium so that it went from +being a mere novelty from Fred Sneeze in + + align:start position:0% +being a mere novelty from Fred Sneeze in + + + align:start position:0% +being a mere novelty from Fred Sneeze in +20 years or so 25 years to being a + + align:start position:0% +20 years or so 25 years to being a + + + align:start position:0% +20 years or so 25 years to being a +medium + + align:start position:0% +medium + + + align:start position:0% +medium +astonishingly rich and complex narrative + + align:start position:0% +astonishingly rich and complex narrative + + + align:start position:0% +astonishingly rich and complex narrative +art. That progress uh is part of what I + + align:start position:0% +art. That progress uh is part of what I + + + align:start position:0% +art. That progress uh is part of what I +mean by the um Fredot principle. And and + + align:start position:0% +mean by the um Fredot principle. And and + + + align:start position:0% +mean by the um Fredot principle. And and +it might be helpful if I if I concretize + + align:start position:0% +it might be helpful if I if I concretize + + + align:start position:0% +it might be helpful if I if I concretize +that a little bit more by mentioning a + + align:start position:0% +that a little bit more by mentioning a + + + align:start position:0% +that a little bit more by mentioning a +bit more about what I mean about the + + align:start position:0% +bit more about what I mean about the + + + align:start position:0% +bit more about what I mean about the +what I was implying or referring to when + + align:start position:0% +what I was implying or referring to when + + + align:start position:0% +what I was implying or referring to when +I spoke about that moment of imitation. + + align:start position:0% +I spoke about that moment of imitation. + + + align:start position:0% +I spoke about that moment of imitation. +Remember I said that there were + + align:start position:0% +Remember I said that there were + + + align:start position:0% +Remember I said that there were +essentially three that the that the that + + align:start position:0% +essentially three that the that the that + + + align:start position:0% +essentially three that the that the that +silent film and incidentally I take it + + align:start position:0% +silent film and incidentally I take it + + + align:start position:0% +silent film and incidentally I take it +as a model for the way in which most new + + align:start position:0% +as a model for the way in which most new + + + align:start position:0% +as a model for the way in which most new +media systems uh develop in culture. You + + align:start position:0% +media systems uh develop in culture. You + + + align:start position:0% +media systems uh develop in culture. You +can apply this same basic schema to + + align:start position:0% +can apply this same basic schema to + + + align:start position:0% +can apply this same basic schema to +other forms of of popular entertainment + + align:start position:0% +other forms of of popular entertainment + + + align:start position:0% +other forms of of popular entertainment +including + + align:start position:0% +including + + + align:start position:0% +including +shocking as it may seem Shakespeare's + + align:start position:0% +shocking as it may seem Shakespeare's + + + align:start position:0% +shocking as it may seem Shakespeare's +public theater. And I'll come back to + + align:start position:0% +public theater. And I'll come back to + + + align:start position:0% +public theater. And I'll come back to +the implications of that analogy. The + + align:start position:0% +the implications of that analogy. The + + + align:start position:0% +the implications of that analogy. The +idea that Shakespeare was the movie of + + align:start position:0% +idea that Shakespeare was the movie of + + + align:start position:0% +idea that Shakespeare was the movie of +his time, that Shakespeare's theater was + + align:start position:0% +his time, that Shakespeare's theater was + + + align:start position:0% +his time, that Shakespeare's theater was +the Hollywood studio system of of of the + + align:start position:0% +the Hollywood studio system of of of the + + + align:start position:0% +the Hollywood studio system of of of the +of the Elizabethan era is a very + + align:start position:0% +of the Elizabethan era is a very + + + align:start position:0% +of the Elizabethan era is a very +complicated one. It's a very inspiring + + align:start position:0% +complicated one. It's a very inspiring + + + align:start position:0% +complicated one. It's a very inspiring +one. And it's it's complicated because + + align:start position:0% +one. And it's it's complicated because + + + align:start position:0% +one. And it's it's complicated because +it makes us reassess our inherited + + align:start position:0% +it makes us reassess our inherited + + + align:start position:0% +it makes us reassess our inherited +notions about what art is and where art + + align:start position:0% +notions about what art is and where art + + + align:start position:0% +notions about what art is and where art +comes from. One of the subtexts in this + + align:start position:0% +comes from. One of the subtexts in this + + + align:start position:0% +comes from. One of the subtexts in this +course is precisely that. the has to do + + align:start position:0% +course is precisely that. the has to do + + + align:start position:0% +course is precisely that. the has to do +with what I call the enabling conditions + + align:start position:0% +with what I call the enabling conditions + + + align:start position:0% +with what I call the enabling conditions +of art and I'll come back to that again + + align:start position:0% +of art and I'll come back to that again + + + align:start position:0% +of art and I'll come back to that again +as a theme again and again in in the + + align:start position:0% +as a theme again and again in in the + + + align:start position:0% +as a theme again and again in in the +course. So part of what I mean by the + + align:start position:0% +course. So part of what I mean by the + + + align:start position:0% +course. So part of what I mean by the +Fred out principle is this is this uh + + align:start position:0% +Fred out principle is this is this uh + + + align:start position:0% +Fred out principle is this is this uh +roing complex uh uh um uh partly + + align:start position:0% +roing complex uh uh um uh partly + + + align:start position:0% +roing complex uh uh um uh partly +unpredictable process whereby uh au an + + align:start position:0% +unpredictable process whereby uh au an + + + align:start position:0% +unpredictable process whereby uh au an +enlarging population incredibly hungry + + align:start position:0% +enlarging population incredibly hungry + + + align:start position:0% +enlarging population incredibly hungry +for the novelties being produced by this + + align:start position:0% +for the novelties being produced by this + + + align:start position:0% +for the novelties being produced by this +new technology create uh a kind of + + align:start position:0% +new technology create uh a kind of + + + align:start position:0% +new technology create uh a kind of +symbiotic relationship between the + + align:start position:0% +symbiotic relationship between the + + + align:start position:0% +symbiotic relationship between the +audience and the emerging medium. So + + align:start position:0% +audience and the emerging medium. So + + + align:start position:0% +audience and the emerging medium. So +that as the medium be the medium grows + + align:start position:0% +that as the medium be the medium grows + + + align:start position:0% +that as the medium be the medium grows +more complicated in part because the + + align:start position:0% +more complicated in part because the + + + align:start position:0% +more complicated in part because the +audience okay after five or 10 or 15 + + align:start position:0% +audience okay after five or 10 or 15 + + + align:start position:0% +audience okay after five or 10 or 15 +visits to the to the Nickelodeon or uh + + align:start position:0% +visits to the to the Nickelodeon or uh + + + align:start position:0% +visits to the to the Nickelodeon or uh +or to the the a after the movies moved + + align:start position:0% +or to the the a after the movies moved + + + align:start position:0% +or to the the a after the movies moved +out of after the movies moved out of the + + align:start position:0% +out of after the movies moved out of the + + + align:start position:0% +out of after the movies moved out of the +penny arcades and began to take their + + align:start position:0% +penny arcades and began to take their + + + align:start position:0% +penny arcades and began to take their +own space as some of you know and as as + + align:start position:0% +own space as some of you know and as as + + + align:start position:0% +own space as some of you know and as as +is recounted in our reading for this for + + align:start position:0% +is recounted in our reading for this for + + + align:start position:0% +is recounted in our reading for this for +these early weeks. The movies first + + align:start position:0% +these early weeks. The movies first + + + align:start position:0% +these early weeks. The movies first +moved out into what were called + + align:start position:0% +moved out into what were called + + + align:start position:0% +moved out into what were called +Nickelodeons, right? They were they were + + align:start position:0% +Nickelodeons, right? They were they were + + + align:start position:0% +Nickelodeons, right? They were they were +uh storefronts in the for the most part + + align:start position:0% +uh storefronts in the for the most part + + + align:start position:0% +uh storefronts in the for the most part +in which you and the admission was a + + align:start position:0% +in which you and the admission was a + + + align:start position:0% +in which you and the admission was a +nickel. That's why they were called + + align:start position:0% +nickel. That's why they were called + + + align:start position:0% +nickel. That's why they were called +Nickelodeons. Uh and uh you sat in in + + align:start position:0% +Nickelodeons. Uh and uh you sat in in + + + align:start position:0% +Nickelodeons. Uh and uh you sat in in +many of these on benches without backs + + align:start position:0% +many of these on benches without backs + + + align:start position:0% +many of these on benches without backs +next to strangers. You didn't have + + align:start position:0% +next to strangers. You didn't have + + + align:start position:0% +next to strangers. You didn't have +private seats and you would sit in there + + align:start position:0% +private seats and you would sit in there + + + align:start position:0% +private seats and you would sit in there +and see a series of short films. So but + + align:start position:0% +and see a series of short films. So but + + + align:start position:0% +and see a series of short films. So but +the fact that the Nickelodeons emerged + + align:start position:0% +the fact that the Nickelodeons emerged + + + align:start position:0% +the fact that the Nickelodeons emerged +so quickly is a mark of how popular an + + align:start position:0% +so quickly is a mark of how popular an + + + align:start position:0% +so quickly is a mark of how popular an +uh film became even even in the even in + + align:start position:0% +uh film became even even in the even in + + + align:start position:0% +uh film became even even in the even in +its relatively primitive early form. Uh + + align:start position:0% +its relatively primitive early form. Uh + + + align:start position:0% +its relatively primitive early form. Uh +and and then of course within a few + + align:start position:0% +and and then of course within a few + + + align:start position:0% +and and then of course within a few +years of the Nickelodeons appearing what + + align:start position:0% +years of the Nickelodeons appearing what + + + align:start position:0% +years of the Nickelodeons appearing what +else began to happen? Theaters made + + align:start position:0% +else began to happen? Theaters made + + + align:start position:0% +else began to happen? Theaters made +specially for the showing of motion + + align:start position:0% +specially for the showing of motion + + + align:start position:0% +specially for the showing of motion +pictures that were longer than the early + + align:start position:0% +pictures that were longer than the early + + + align:start position:0% +pictures that were longer than the early +shorts because film began to expand its + + align:start position:0% +shorts because film began to expand its + + + align:start position:0% +shorts because film began to expand its +length all through the period from 1910 + + align:start position:0% +length all through the period from 1910 + + + align:start position:0% +length all through the period from 1910 +through 1920. Right? What what's the + + align:start position:0% +through 1920. Right? What what's the + + + align:start position:0% +through 1920. Right? What what's the +great moment when the feature film is + + align:start position:0% +great moment when the feature film is + + + align:start position:0% +great moment when the feature film is +born in the United States? 1915. Who's + + align:start position:0% +born in the United States? 1915. Who's + + + align:start position:0% +born in the United States? 1915. Who's +the director? DW Griffith. Who's the + + align:start position:0% +the director? DW Griffith. Who's the + + + align:start position:0% +the director? DW Griffith. Who's the +what's the film? Birth of a Nation. + + align:start position:0% +what's the film? Birth of a Nation. + + + align:start position:0% +what's the film? Birth of a Nation. +Birth of a Nation, a very complicated uh + + align:start position:0% +Birth of a Nation, a very complicated uh + + + align:start position:0% +Birth of a Nation, a very complicated uh +example because its content is + + align:start position:0% +example because its content is + + + align:start position:0% +example because its content is +disturbing in some ways. It's a very + + align:start position:0% +disturbing in some ways. It's a very + + + align:start position:0% +disturbing in some ways. It's a very +reactionary and in some respects racist + + align:start position:0% +reactionary and in some respects racist + + + align:start position:0% +reactionary and in some respects racist +film. It it it it it + + align:start position:0% +film. It it it it it + + + align:start position:0% +film. It it it it it +absorbs and carries forward what we + + align:start position:0% +absorbs and carries forward what we + + + align:start position:0% +absorbs and carries forward what we +might think of as the the racial + + align:start position:0% +might think of as the the racial + + + align:start position:0% +might think of as the the racial +prejudices that were uh very widespread + + align:start position:0% +prejudices that were uh very widespread + + + align:start position:0% +prejudices that were uh very widespread +in American society at the turn of the + + align:start position:0% +in American society at the turn of the + + + align:start position:0% +in American society at the turn of the +century and especially in the south from + + align:start position:0% +century and especially in the south from + + + align:start position:0% +century and especially in the south from +which uh Griffith himself was was a + + align:start position:0% +which uh Griffith himself was was a + + + align:start position:0% +which uh Griffith himself was was a +southerner and was born in the south and + + align:start position:0% +southerner and was born in the south and + + + align:start position:0% +southerner and was born in the south and +what his film was deeply influenced by a + + align:start position:0% +what his film was deeply influenced by a + + + align:start position:0% +what his film was deeply influenced by a +best-selling novel called the clansmen + + align:start position:0% +best-selling novel called the clansmen + + + align:start position:0% +best-selling novel called the clansmen +which was a celebration of the Ku Klux + + align:start position:0% +which was a celebration of the Ku Klux + + + align:start position:0% +which was a celebration of the Ku Klux +Clan uh and the uh birth of a nation. + + align:start position:0% +Clan uh and the uh birth of a nation. + + + align:start position:0% +Clan uh and the uh birth of a nation. +So, so the content of Birth of a Nation + + align:start position:0% +So, so the content of Birth of a Nation + + + align:start position:0% +So, so the content of Birth of a Nation +is very unsettling and disturbing. And + + align:start position:0% +is very unsettling and disturbing. And + + + align:start position:0% +is very unsettling and disturbing. And +even when it was first uh um released to + + align:start position:0% +even when it was first uh um released to + + + align:start position:0% +even when it was first uh um released to +the public to great claim because it it + + align:start position:0% +the public to great claim because it it + + + align:start position:0% +the public to great claim because it it +it it expanded the possibilities of + + align:start position:0% +it it expanded the possibilities of + + + align:start position:0% +it it expanded the possibilities of +movies in all kinds of ways. From a + + align:start position:0% +movies in all kinds of ways. From a + + + align:start position:0% +movies in all kinds of ways. From a +technical standpoint, it is an + + align:start position:0% +technical standpoint, it is an + + + align:start position:0% +technical standpoint, it is an +astonishingly important film. And from a + + align:start position:0% +astonishingly important film. And from a + + + align:start position:0% +astonishingly important film. And from a +content standpoint, it's a very + + align:start position:0% +content standpoint, it's a very + + + align:start position:0% +content standpoint, it's a very +disturbing film. It's a wonderful + + align:start position:0% +disturbing film. It's a wonderful + + + align:start position:0% +disturbing film. It's a wonderful +reminder of the fact that this progress + + align:start position:0% +reminder of the fact that this progress + + + align:start position:0% +reminder of the fact that this progress +I'm describing to you is not an unaloyed + + align:start position:0% +I'm describing to you is not an unaloyed + + + align:start position:0% +I'm describing to you is not an unaloyed +triumphal story. Uh even as the movies + + align:start position:0% +triumphal story. Uh even as the movies + + + align:start position:0% +triumphal story. Uh even as the movies +became more technically complicated and + + align:start position:0% +became more technically complicated and + + + align:start position:0% +became more technically complicated and +and uh more demanding and longer and + + align:start position:0% +and uh more demanding and longer and + + + align:start position:0% +and uh more demanding and longer and +more interested in character, they also + + align:start position:0% +more interested in character, they also + + + align:start position:0% +more interested in character, they also +nonetheless carried the lies and + + align:start position:0% +nonetheless carried the lies and + + + align:start position:0% +nonetheless carried the lies and +prejudices and and um um um hierarchic + + align:start position:0% +prejudices and and um um um hierarchic + + + align:start position:0% +prejudices and and um um um hierarchic +assumptions that were embedded in the + + align:start position:0% +assumptions that were embedded in the + + + align:start position:0% +assumptions that were embedded in the +society from which they arose. How could + + align:start position:0% +society from which they arose. How could + + + align:start position:0% +society from which they arose. How could +it be otherwise? Every media form does + + align:start position:0% +it be otherwise? Every media form does + + + align:start position:0% +it be otherwise? Every media form does +this. But it's but it's important to + + align:start position:0% +this. But it's but it's important to + + + align:start position:0% +this. But it's but it's important to +make this point as a way of reminding us + + align:start position:0% +make this point as a way of reminding us + + + align:start position:0% +make this point as a way of reminding us +that the story we're telling is not uh + + align:start position:0% +that the story we're telling is not uh + + + align:start position:0% +that the story we're telling is not uh +in some simple sense just a kind of a + + align:start position:0% +in some simple sense just a kind of a + + + align:start position:0% +in some simple sense just a kind of a +kind of progress myth in which we're + + align:start position:0% +kind of progress myth in which we're + + + align:start position:0% +kind of progress myth in which we're +celebrating development and and and + + align:start position:0% +celebrating development and and and + + + align:start position:0% +celebrating development and and and +genius. We're we're we're identifying + + align:start position:0% +genius. We're we're we're identifying + + + align:start position:0% +genius. We're we're we're identifying +and locating something more complicated + + align:start position:0% +and locating something more complicated + + + align:start position:0% +and locating something more complicated +than that. the process whereby these + + align:start position:0% +than that. the process whereby these + + + align:start position:0% +than that. the process whereby these +cultural myths uh and these stories that + + align:start position:0% +cultural myths uh and these stories that + + + align:start position:0% +cultural myths uh and these stories that +are drawn from inherited older stories + + align:start position:0% +are drawn from inherited older stories + + + align:start position:0% +are drawn from inherited older stories +and from and from the lore of the + + align:start position:0% +and from and from the lore of the + + + align:start position:0% +and from and from the lore of the +society more broadly, more generally uh + + align:start position:0% +society more broadly, more generally uh + + + align:start position:0% +society more broadly, more generally uh +uh are are transformed into this new + + align:start position:0% +uh are are transformed into this new + + + align:start position:0% +uh are are transformed into this new +medium and they have a tremendous + + align:start position:0% +medium and they have a tremendous + + + align:start position:0% +medium and they have a tremendous +technical interest. But very often they + + align:start position:0% +technical interest. But very often they + + + align:start position:0% +technical interest. But very often they +also have a kind of cultural or + + align:start position:0% +also have a kind of cultural or + + + align:start position:0% +also have a kind of cultural or +sociological interest of a negative kind + + align:start position:0% +sociological interest of a negative kind + + + align:start position:0% +sociological interest of a negative kind +in the sense that what they reveal are + + align:start position:0% +in the sense that what they reveal are + + + align:start position:0% +in the sense that what they reveal are +the prejudices, the lies, the + + align:start position:0% +the prejudices, the lies, the + + + align:start position:0% +the prejudices, the lies, the +limitations uh of the society that's + + align:start position:0% +limitations uh of the society that's + + + align:start position:0% +limitations uh of the society that's +given the the mythologies that sustain + + align:start position:0% +given the the mythologies that sustain + + + align:start position:0% +given the the mythologies that sustain +the society. Again, this is a matter to + + align:start position:0% +the society. Again, this is a matter to + + + align:start position:0% +the society. Again, this is a matter to +which we'll return. One of the deep + + align:start position:0% +which we'll return. One of the deep + + + align:start position:0% +which we'll return. One of the deep +cultural functions of American movies + + align:start position:0% +cultural functions of American movies + + + align:start position:0% +cultural functions of American movies +especially was to promulgate a kind of + + align:start position:0% +especially was to promulgate a kind of + + + align:start position:0% +especially was to promulgate a kind of +mythology of America. And we'll talk + + align:start position:0% +mythology of America. And we'll talk + + + align:start position:0% +mythology of America. And we'll talk +more about this when we when we when we + + align:start position:0% +more about this when we when we when we + + + align:start position:0% +more about this when we when we when we +reach certain genre forms in the second + + align:start position:0% +reach certain genre forms in the second + + + align:start position:0% +reach certain genre forms in the second +segment of the course. + + align:start position:0% +segment of the course. + + + align:start position:0% +segment of the course. +I said something earlier this morning + + align:start position:0% +I said something earlier this morning + + + align:start position:0% +I said something earlier this morning +that I want to make uh explicit + + align:start position:0% +that I want to make uh explicit + + + align:start position:0% +that I want to make uh explicit +uh because I think it's an important + + align:start position:0% +uh because I think it's an important + + + align:start position:0% +uh because I think it's an important +another way of qualifying this triumphal + + align:start position:0% +another way of qualifying this triumphal + + + align:start position:0% +another way of qualifying this triumphal +story. It's hard because I'm + + align:start position:0% +story. It's hard because I'm + + + align:start position:0% +story. It's hard because I'm +enthusiastic about what I'm looking at + + align:start position:0% +enthusiastic about what I'm looking at + + + align:start position:0% +enthusiastic about what I'm looking at +and there is some material that's so + + align:start position:0% +and there is some material that's so + + + align:start position:0% +and there is some material that's so +exciting here to watch. In a way what + + align:start position:0% +exciting here to watch. In a way what + + + align:start position:0% +exciting here to watch. In a way what +we're watching is we're watching the + + align:start position:0% +we're watching is we're watching the + + + align:start position:0% +we're watching is we're watching the +birth of the movies. We're watching the + + align:start position:0% +birth of the movies. We're watching the + + + align:start position:0% +birth of the movies. We're watching the +the the discovery of the language of + + align:start position:0% +the the discovery of the language of + + + align:start position:0% +the the discovery of the language of +cinema in these early films. And that's + + align:start position:0% +cinema in these early films. And that's + + + align:start position:0% +cinema in these early films. And that's +why even though from an artistic + + align:start position:0% +why even though from an artistic + + + align:start position:0% +why even though from an artistic +standpoint, some of these shorts are not + + align:start position:0% +standpoint, some of these shorts are not + + + align:start position:0% +standpoint, some of these shorts are not +very rich. I hope they're interesting + + align:start position:0% +very rich. I hope they're interesting + + + align:start position:0% +very rich. I hope they're interesting +enough that I've made them interesting + + align:start position:0% +enough that I've made them interesting + + + align:start position:0% +enough that I've made them interesting +to you from a historical standpoint. If + + align:start position:0% +to you from a historical standpoint. If + + + align:start position:0% +to you from a historical standpoint. If +you look at them closely, you can see ve + + align:start position:0% +you look at them closely, you can see ve + + + align:start position:0% +you look at them closely, you can see ve +you can see the movies being born. You + + align:start position:0% +you can see the movies being born. You + + + align:start position:0% +you can see the movies being born. You +can see a language, a syntax for + + align:start position:0% +can see a language, a syntax for + + + align:start position:0% +can see a language, a syntax for +speaking in pictures for for this new + + align:start position:0% +speaking in pictures for for this new + + + align:start position:0% +speaking in pictures for for this new +new visual language being this new + + align:start position:0% +new visual language being this new + + + align:start position:0% +new visual language being this new +visual medium being developed. uh and + + align:start position:0% +visual medium being developed. uh and + + + align:start position:0% +visual medium being developed. uh and +and I I'll if I have time this evening, + + align:start position:0% +and I I'll if I have time this evening, + + + align:start position:0% +and I I'll if I have time this evening, +I'll give you a few more concrete + + align:start position:0% +I'll give you a few more concrete + + + align:start position:0% +I'll give you a few more concrete +examples of that. But another way in + + align:start position:0% +examples of that. But another way in + + + align:start position:0% +examples of that. But another way in +which one can qualify this apparently + + align:start position:0% +which one can qualify this apparently + + + align:start position:0% +which one can qualify this apparently +triumphal story, it's not a triumphal + + align:start position:0% +triumphal story, it's not a triumphal + + + align:start position:0% +triumphal story, it's not a triumphal +story, even though it is a story of + + align:start position:0% +story, even though it is a story of + + + align:start position:0% +story, even though it is a story of +refinement, development, and evolution + + align:start position:0% +refinement, development, and evolution + + + align:start position:0% +refinement, development, and evolution +of a of a kind that involves increasing + + align:start position:0% +of a of a kind that involves increasing + + + align:start position:0% +of a of a kind that involves increasing +complexity and technical perfection, + + align:start position:0% +complexity and technical perfection, + + + align:start position:0% +complexity and technical perfection, +technical uh uh mastery. uh it's not + + align:start position:0% +technical uh uh mastery. uh it's not + + + align:start position:0% +technical uh uh mastery. uh it's not +merely that or not or not or not even + + align:start position:0% +merely that or not or not or not even + + + align:start position:0% +merely that or not or not or not even +primarily that it's very important to + + align:start position:0% +primarily that it's very important to + + + align:start position:0% +primarily that it's very important to +recognize among other things as I + + align:start position:0% +recognize among other things as I + + + align:start position:0% +recognize among other things as I +implied this afternoon that uh not all + + align:start position:0% +implied this afternoon that uh not all + + + align:start position:0% +implied this afternoon that uh not all +the possibilities that are inherent in + + align:start position:0% +the possibilities that are inherent in + + + align:start position:0% +the possibilities that are inherent in +the in the in the nent medium aren't + + align:start position:0% +the in the in the nent medium aren't + + + align:start position:0% +the in the in the nent medium aren't +necessarily exploited in a particular + + align:start position:0% +necessarily exploited in a particular + + + align:start position:0% +necessarily exploited in a particular +cultural moment or or maybe ever + + align:start position:0% +cultural moment or or maybe ever + + + align:start position:0% +cultural moment or or maybe ever +exploited depending on how things + + align:start position:0% +exploited depending on how things + + + align:start position:0% +exploited depending on how things +develop. That is to say, uh, I mentioned + + align:start position:0% +develop. That is to say, uh, I mentioned + + + align:start position:0% +develop. That is to say, uh, I mentioned +this this afternoon, uh, how, for + + align:start position:0% +this this afternoon, uh, how, for + + + align:start position:0% +this this afternoon, uh, how, for +instance, + + align:start position:0% +instance, + + + align:start position:0% +instance, +when Edison first conceived the + + align:start position:0% +when Edison first conceived the + + + align:start position:0% +when Edison first conceived the +apparatus before it was actually + + align:start position:0% +apparatus before it was actually + + + align:start position:0% +apparatus before it was actually +invented of the mo of the motion picture + + align:start position:0% +invented of the mo of the motion picture + + + align:start position:0% +invented of the mo of the motion picture +projector and the motion picture camera, + + align:start position:0% +projector and the motion picture camera, + + + align:start position:0% +projector and the motion picture camera, +his first idea was that he would create + + align:start position:0% +his first idea was that he would create + + + align:start position:0% +his first idea was that he would create +an an item that would be a consumer item + + align:start position:0% +an an item that would be a consumer item + + + align:start position:0% +an an item that would be a consumer item +that would be sold to individual + + align:start position:0% +that would be sold to individual + + + align:start position:0% +that would be sold to individual +families and the film would become, you + + align:start position:0% +families and the film would become, you + + + align:start position:0% +families and the film would become, you +know, the the an equivalent of a kind of + + align:start position:0% +know, the the an equivalent of a kind of + + + align:start position:0% +know, the the an equivalent of a kind of +a photo album, although it would it + + align:start position:0% +a photo album, although it would it + + + align:start position:0% +a photo album, although it would it +would have motion in it and and the and + + align:start position:0% +would have motion in it and and the and + + + align:start position:0% +would have motion in it and and the and +as I suggested this this morning this + + align:start position:0% +as I suggested this this morning this + + + align:start position:0% +as I suggested this this morning this +afternoon there's no reason why given + + align:start position:0% +afternoon there's no reason why given + + + align:start position:0% +afternoon there's no reason why given +the nature of the technology itself that + + align:start position:0% +the nature of the technology itself that + + + align:start position:0% +the nature of the technology itself that +that vision of how film might develop + + align:start position:0% +that vision of how film might develop + + + align:start position:0% +that vision of how film might develop +was impossible. In fact, it wasn't + + align:start position:0% +was impossible. In fact, it wasn't + + + align:start position:0% +was impossible. In fact, it wasn't +impossible. It was just incredibly ahead + + align:start position:0% +impossible. It was just incredibly ahead + + + align:start position:0% +impossible. It was just incredibly ahead +of its time. It took it took a half a + + align:start position:0% +of its time. It took it took a half a + + + align:start position:0% +of its time. It took it took a half a +century before something like that + + align:start position:0% +century before something like that + + + align:start position:0% +century before something like that +actually became available in society. + + align:start position:0% +actually became available in society. + + + align:start position:0% +actually became available in society. +But there was no reason in terms of the + + align:start position:0% +But there was no reason in terms of the + + + align:start position:0% +But there was no reason in terms of the +the possibilities of the technology that + + align:start position:0% +the possibilities of the technology that + + + align:start position:0% +the possibilities of the technology that +that that needed to happen. What I'm + + align:start position:0% +that that needed to happen. What I'm + + + align:start position:0% +that that needed to happen. What I'm +calling your attention to is what is a + + align:start position:0% +calling your attention to is what is a + + + align:start position:0% +calling your attention to is what is a +very widespread myth. It's especially + + align:start position:0% +very widespread myth. It's especially + + + align:start position:0% +very widespread myth. It's especially +pernicious and widespread at MIT and + + align:start position:0% +pernicious and widespread at MIT and + + + align:start position:0% +pernicious and widespread at MIT and +it's ve for reasons that are obvious and + + align:start position:0% +it's ve for reasons that are obvious and + + + align:start position:0% +it's ve for reasons that are obvious and +understandable. We at MIT love to + + align:start position:0% +understandable. We at MIT love to + + + align:start position:0% +understandable. We at MIT love to +believe that technology will solve all + + align:start position:0% +believe that technology will solve all + + + align:start position:0% +believe that technology will solve all +problems. The primary thing I'm + + align:start position:0% +problems. The primary thing I'm + + + align:start position:0% +problems. The primary thing I'm +suggesting to you is that the evolution + + align:start position:0% +suggesting to you is that the evolution + + + align:start position:0% +suggesting to you is that the evolution +of the movies that I want you to be + + align:start position:0% +of the movies that I want you to be + + + align:start position:0% +of the movies that I want you to be +aware of this process of increasing + + align:start position:0% +aware of this process of increasing + + + align:start position:0% +aware of this process of increasing +complexity and and uh uh uh compression + + align:start position:0% +complexity and and uh uh uh compression + + + align:start position:0% +complexity and and uh uh uh compression +in which in in which the movies become a + + align:start position:0% +in which in in which the movies become a + + + align:start position:0% +in which in in which the movies become a +more and more independent form of + + align:start position:0% +more and more independent form of + + + align:start position:0% +more and more independent form of +expression in which the movies begin to + + align:start position:0% +expression in which the movies begin to + + + align:start position:0% +expression in which the movies begin to +discover the unique characteristics of + + align:start position:0% +discover the unique characteristics of + + + align:start position:0% +discover the unique characteristics of +the motion picture camera and of the + + align:start position:0% +the motion picture camera and of the + + + align:start position:0% +the motion picture camera and of the +environment of the movie theater that + + align:start position:0% +environment of the movie theater that + + + align:start position:0% +environment of the movie theater that +that the movie that the movies begin to + + align:start position:0% +that the movie that the movies begin to + + + align:start position:0% +that the movie that the movies begin to +explore those qualities in this new + + align:start position:0% +explore those qualities in this new + + + align:start position:0% +explore those qualities in this new +medium that are unique and special. That + + align:start position:0% +medium that are unique and special. That + + + align:start position:0% +medium that are unique and special. That +process is important and I want you to + + align:start position:0% +process is important and I want you to + + + align:start position:0% +process is important and I want you to +be aware of it. But I don't want you to + + align:start position:0% +be aware of it. But I don't want you to + + + align:start position:0% +be aware of it. But I don't want you to +embrace that principle too uncritically + + align:start position:0% +embrace that principle too uncritically + + + align:start position:0% +embrace that principle too uncritically +because I want you to recognize that + + align:start position:0% +because I want you to recognize that + + + align:start position:0% +because I want you to recognize that +what that that the technology itself + + align:start position:0% +what that that the technology itself + + + align:start position:0% +what that that the technology itself +does not explain this process. The + + align:start position:0% +does not explain this process. The + + + align:start position:0% +does not explain this process. The +process is explained by cultural factors + + align:start position:0% +process is explained by cultural factors + + + align:start position:0% +process is explained by cultural factors +and social factors and even individual + + align:start position:0% +and social factors and even individual + + + align:start position:0% +and social factors and even individual +sometimes individual psychological + + align:start position:0% +sometimes individual psychological + + + align:start position:0% +sometimes individual psychological +factors. Right? Uh what we're talking + + align:start position:0% +factors. Right? Uh what we're talking + + + align:start position:0% +factors. Right? Uh what we're talking +about here is the myth of technological + + align:start position:0% +about here is the myth of technological + + + align:start position:0% +about here is the myth of technological +determinism. The myth that technology + + align:start position:0% +determinism. The myth that technology + + + align:start position:0% +determinism. The myth that technology +drives culture. the myth that a new + + align:start position:0% +drives culture. the myth that a new + + + align:start position:0% +drives culture. the myth that a new +invention obliterates old inventions. + + align:start position:0% +invention obliterates old inventions. + + + align:start position:0% +invention obliterates old inventions. +The truth is much more complicated than + + align:start position:0% +The truth is much more complicated than + + + align:start position:0% +The truth is much more complicated than +that. And one of the most remarkable + + align:start position:0% +that. And one of the most remarkable + + + align:start position:0% +that. And one of the most remarkable +things about this evolutionary process + + align:start position:0% +things about this evolutionary process + + + align:start position:0% +things about this evolutionary process +I've been describing, as I said earlier, + + align:start position:0% +I've been describing, as I said earlier, + + + align:start position:0% +I've been describing, as I said earlier, +is how swift it is, how fast it is, how + + align:start position:0% +is how swift it is, how fast it is, how + + + align:start position:0% +is how swift it is, how fast it is, how +we go from being a mere novelty to + + align:start position:0% +we go from being a mere novelty to + + + align:start position:0% +we go from being a mere novelty to +becoming a a significant social form by + + align:start position:0% +becoming a a significant social form by + + + align:start position:0% +becoming a a significant social form by +1910 or so and to becoming a virtually + + align:start position:0% +1910 or so and to becoming a virtually + + + align:start position:0% +1910 or so and to becoming a virtually +universal aesthetic and entertainment + + align:start position:0% +universal aesthetic and entertainment + + + align:start position:0% +universal aesthetic and entertainment +experience for the majority of the + + align:start position:0% +experience for the majority of the + + + align:start position:0% +experience for the majority of the +population in the country by 1920. So in + + align:start position:0% +population in the country by 1920. So in + + + align:start position:0% +population in the country by 1920. So in +something like 20 or 25 years, the + + align:start position:0% +something like 20 or 25 years, the + + + align:start position:0% +something like 20 or 25 years, the +movies go from being an absolutely + + align:start position:0% +movies go from being an absolutely + + + align:start position:0% +movies go from being an absolutely +unknown or trivial novelty, sharing + + align:start position:0% +unknown or trivial novelty, sharing + + + align:start position:0% +unknown or trivial novelty, sharing +space with fortune tellers and strip and + + align:start position:0% +space with fortune tellers and strip and + + + align:start position:0% +space with fortune tellers and strip and +and strip shows in the penny arcades to + + align:start position:0% +and strip shows in the penny arcades to + + + align:start position:0% +and strip shows in the penny arcades to +becoming not just an embedded social + + align:start position:0% +becoming not just an embedded social + + + align:start position:0% +becoming not just an embedded social +form but one of the dominant economic + + align:start position:0% +form but one of the dominant economic + + + align:start position:0% +form but one of the dominant economic +engines of the society, employing tens + + align:start position:0% +engines of the society, employing tens + + + align:start position:0% +engines of the society, employing tens +of thousands of people in various uh + + align:start position:0% +of thousands of people in various uh + + + align:start position:0% +of thousands of people in various uh +direct and ancillary positions and + + align:start position:0% +direct and ancillary positions and + + + align:start position:0% +direct and ancillary positions and +mobilizing virtually the entire + + align:start position:0% +mobilizing virtually the entire + + + align:start position:0% +mobilizing virtually the entire +population of the country in an an in a + + align:start position:0% +population of the country in an an in a + + + align:start position:0% +population of the country in an an in a +regular a routine and habitual + + align:start position:0% +regular a routine and habitual + + + align:start position:0% +regular a routine and habitual +experience uh um uh to which they return + + align:start position:0% +experience uh um uh to which they return + + + align:start position:0% +experience uh um uh to which they return +again and again and because the audience + + align:start position:0% +again and again and because the audience + + + align:start position:0% +again and again and because the audience +is returning again and again I remember + + align:start position:0% +is returning again and again I remember + + + align:start position:0% +is returning again and again I remember +I said there's a kind of symbiotic + + align:start position:0% +I said there's a kind of symbiotic + + + align:start position:0% +I said there's a kind of symbiotic +relation between the audience and the + + align:start position:0% +relation between the audience and the + + + align:start position:0% +relation between the audience and the +because the audience is returning again + + align:start position:0% +because the audience is returning again + + + align:start position:0% +because the audience is returning again +and again what happens that's also an + + align:start position:0% +and again what happens that's also an + + + align:start position:0% +and again what happens that's also an +aspect of the resources that are + + align:start position:0% +aspect of the resources that are + + + align:start position:0% +aspect of the resources that are +available to the medium what begins then + + align:start position:0% +available to the medium what begins then + + + align:start position:0% +available to the medium what begins then +to develop are form are are forms of + + align:start position:0% +to develop are form are are forms of + + + align:start position:0% +to develop are form are are forms of +storytelling that rely on the audience's + + align:start position:0% +storytelling that rely on the audience's + + + align:start position:0% +storytelling that rely on the audience's +prior memory of other shows, right? So + + align:start position:0% +prior memory of other shows, right? So + + + align:start position:0% +prior memory of other shows, right? So +that one thing that emerges very quickly + + align:start position:0% +that one thing that emerges very quickly + + + align:start position:0% +that one thing that emerges very quickly +is what we might call a star system in + + align:start position:0% +is what we might call a star system in + + + align:start position:0% +is what we might call a star system in +which particular actors are become + + align:start position:0% +which particular actors are become + + + align:start position:0% +which particular actors are become +identified with particular kinds of + + align:start position:0% +identified with particular kinds of + + + align:start position:0% +identified with particular kinds of +roles and audiences want to come back to + + align:start position:0% +roles and audiences want to come back to + + + align:start position:0% +roles and audiences want to come back to +see those stars again and again. What + + align:start position:0% +see those stars again and again. What + + + align:start position:0% +see those stars again and again. What +also begins to happen is the + + align:start position:0% +also begins to happen is the + + + align:start position:0% +also begins to happen is the +establishment of a very rigorous kind of + + align:start position:0% +establishment of a very rigorous kind of + + + align:start position:0% +establishment of a very rigorous kind of +genre system. What's a genre? A category + + align:start position:0% +genre system. What's a genre? A category + + + align:start position:0% +genre system. What's a genre? A category +of story. The western is a genre. The + + align:start position:0% +of story. The western is a genre. The + + + align:start position:0% +of story. The western is a genre. The +detective story is a genre. The elegy is + + align:start position:0% +detective story is a genre. The elegy is + + + align:start position:0% +detective story is a genre. The elegy is +a poetic genre. Right? That so so + + align:start position:0% +a poetic genre. Right? That so so + + + align:start position:0% +a poetic genre. Right? That so so +genres. So and and and the movie the the + + align:start position:0% +genres. So and and and the movie the the + + + align:start position:0% +genres. So and and and the movie the the +typical the fundamental movie genres + + align:start position:0% +typical the fundamental movie genres + + + align:start position:0% +typical the fundamental movie genres +begin to emerge relatively early. + + align:start position:0% +begin to emerge relatively early. + + + align:start position:0% +begin to emerge relatively early. +There's a western adventure story. + + align:start position:0% +There's a western adventure story. + + + align:start position:0% +There's a western adventure story. +There's a historical spectacle. Uh there + + align:start position:0% +There's a historical spectacle. Uh there + + + align:start position:0% +There's a historical spectacle. Uh there +are certain forms of urban crime + + align:start position:0% +are certain forms of urban crime + + + align:start position:0% +are certain forms of urban crime +narrative that that became our detective + + align:start position:0% +narrative that that became our detective + + + align:start position:0% +narrative that that became our detective +and crime films at a later at a later + + align:start position:0% +and crime films at a later at a later + + + align:start position:0% +and crime films at a later at a later +stage. Uh and there are certain and + + align:start position:0% +stage. Uh and there are certain and + + + align:start position:0% +stage. Uh and there are certain and +there emerge especially certain forms of + + align:start position:0% +there emerge especially certain forms of + + + align:start position:0% +there emerge especially certain forms of +satire and comedy. So so a genre system + + align:start position:0% +satire and comedy. So so a genre system + + + align:start position:0% +satire and comedy. So so a genre system +begins to emerge as well. And there + + align:start position:0% +begins to emerge as well. And there + + + align:start position:0% +begins to emerge as well. And there +there are reasons of course why this + + align:start position:0% +there are reasons of course why this + + + align:start position:0% +there are reasons of course why this +kind of thing is useful to a mass + + align:start position:0% +kind of thing is useful to a mass + + + align:start position:0% +kind of thing is useful to a mass +production system to a system of an + + align:start position:0% +production system to a system of an + + + align:start position:0% +production system to a system of an +assembly line system because look if you + + align:start position:0% +assembly line system because look if you + + + align:start position:0% +assembly line system because look if you +make seven westerns uh if the same uh + + align:start position:0% +make seven westerns uh if the same uh + + + align:start position:0% +make seven westerns uh if the same uh +movie studio makes seven westerns they + + align:start position:0% +movie studio makes seven westerns they + + + align:start position:0% +movie studio makes seven westerns they +can use the same horses again and again + + align:start position:0% +can use the same horses again and again + + + align:start position:0% +can use the same horses again and again +they can use the same set they can use + + align:start position:0% +they can use the same set they can use + + + align:start position:0% +they can use the same set they can use +the same hats they might even be you and + + align:start position:0% +the same hats they might even be you and + + + align:start position:0% +the same hats they might even be you and +this in fact happened they might even be + + align:start position:0% +this in fact happened they might even be + + + align:start position:0% +this in fact happened they might even be +be able to use the same clip of film + + align:start position:0% +be able to use the same clip of film + + + align:start position:0% +be able to use the same clip of film +that shows a cattle stampede in seven + + align:start position:0% +that shows a cattle stampede in seven + + + align:start position:0% +that shows a cattle stampede in seven +different movies because nobody would + + align:start position:0% +different movies because nobody would + + + align:start position:0% +different movies because nobody would +actually see it. So economies of scale + + align:start position:0% +actually see it. So economies of scale + + + align:start position:0% +actually see it. So economies of scale +become possible uh as the system begins + + align:start position:0% +become possible uh as the system begins + + + align:start position:0% +become possible uh as the system begins +to regularize itself once it stabilizes + + align:start position:0% +to regularize itself once it stabilizes + + + align:start position:0% +to regularize itself once it stabilizes +after that period of imitation and + + align:start position:0% +after that period of imitation and + + + align:start position:0% +after that period of imitation and +patent warfare. Right? So one of the + + align:start position:0% +patent warfare. Right? So one of the + + + align:start position:0% +patent warfare. Right? So one of the +things and there's and there's nothing + + align:start position:0% +things and there's and there's nothing + + + align:start position:0% +things and there's and there's nothing +noble or artistic or or or conscious uh + + align:start position:0% +noble or artistic or or or conscious uh + + + align:start position:0% +noble or artistic or or or conscious uh +about this development. That's part of + + align:start position:0% +about this development. That's part of + + + align:start position:0% +about this development. That's part of +what makes it so remarkable and it puts + + align:start position:0% +what makes it so remarkable and it puts + + + align:start position:0% +what makes it so remarkable and it puts +us in touch with a paradox that's at the + + align:start position:0% +us in touch with a paradox that's at the + + + align:start position:0% +us in touch with a paradox that's at the +very heart of what I hope to make you + + align:start position:0% +very heart of what I hope to make you + + + align:start position:0% +very heart of what I hope to make you +aware of in this course. It's a paradox + + align:start position:0% +aware of in this course. It's a paradox + + + align:start position:0% +aware of in this course. It's a paradox +that I guess it animates my transition + + align:start position:0% +that I guess it animates my transition + + + align:start position:0% +that I guess it animates my transition +many years ago now from a traditional + + align:start position:0% +many years ago now from a traditional + + + align:start position:0% +many years ago now from a traditional +literary scholar into someone interested + + align:start position:0% +literary scholar into someone interested + + + align:start position:0% +literary scholar into someone interested +in film and media. And it's this paradox + + align:start position:0% +in film and media. And it's this paradox + + + align:start position:0% +in film and media. And it's this paradox +that based on what I've been telling you + + align:start position:0% +that based on what I've been telling you + + + align:start position:0% +that based on what I've been telling you +about this evolution this evolution of + + align:start position:0% +about this evolution this evolution of + + + align:start position:0% +about this evolution this evolution of +the medium of of the film medium. It's + + align:start position:0% +the medium of of the film medium. It's + + + align:start position:0% +the medium of of the film medium. It's +the paradox that capitalist greed, the + + align:start position:0% +the paradox that capitalist greed, the + + + align:start position:0% +the paradox that capitalist greed, the +crassest of alliances between commerce + + align:start position:0% +crassest of alliances between commerce + + + align:start position:0% +crassest of alliances between commerce +and modern technology + + align:start position:0% +and modern technology + + + align:start position:0% +and modern technology +might be the enabling conditions of a + + align:start position:0% +might be the enabling conditions of a + + + align:start position:0% +might be the enabling conditions of a +complex narrative art. Right? Where does + + align:start position:0% +complex narrative art. Right? Where does + + + align:start position:0% +complex narrative art. Right? Where does +art come from? It's about the and it's + + align:start position:0% +art come from? It's about the and it's + + + align:start position:0% +art come from? It's about the and it's +not just about art though even about + + align:start position:0% +not just about art though even about + + + align:start position:0% +not just about art though even about +sort of social even if even if we forget + + align:start position:0% +sort of social even if even if we forget + + + align:start position:0% +sort of social even if even if we forget +the question of art and just talk about + + align:start position:0% +the question of art and just talk about + + + align:start position:0% +the question of art and just talk about +sort of the the social and cultural + + align:start position:0% +sort of the the social and cultural + + + align:start position:0% +sort of the the social and cultural +importance of moviegoing in modern + + align:start position:0% +importance of moviegoing in modern + + + align:start position:0% +importance of moviegoing in modern +societies. leave out the question of + + align:start position:0% +societies. leave out the question of + + + align:start position:0% +societies. leave out the question of +whether it's an aesthetically valuable + + align:start position:0% +whether it's an aesthetically valuable + + + align:start position:0% +whether it's an aesthetically valuable +experience. It's so central to human + + align:start position:0% +experience. It's so central to human + + + align:start position:0% +experience. It's so central to human +experience, remains so central to human + + align:start position:0% +experience, remains so central to human + + + align:start position:0% +experience, remains so central to human +experience that there's a tremendous par + + align:start position:0% +experience that there's a tremendous par + + + align:start position:0% +experience that there's a tremendous par +that there's a tremendous paradox in + + align:start position:0% +that there's a tremendous paradox in + + + align:start position:0% +that there's a tremendous paradox in +this that the that the crassest of + + align:start position:0% +this that the that the crassest of + + + align:start position:0% +this that the that the crassest of +alliances between commerce and + + align:start position:0% +alliances between commerce and + + + align:start position:0% +alliances between commerce and +technology, right? Nothing noble or + + align:start position:0% +technology, right? Nothing noble or + + + align:start position:0% +technology, right? Nothing noble or +admirable about it. Nobody's sitting + + align:start position:0% +admirable about it. Nobody's sitting + + + align:start position:0% +admirable about it. Nobody's sitting +down thinking I want to make a new great + + align:start position:0% +down thinking I want to make a new great + + + align:start position:0% +down thinking I want to make a new great +medium for art. nonetheless become these + + align:start position:0% +medium for art. nonetheless become these + + + align:start position:0% +medium for art. nonetheless become these +this alliance becomes the enabling + + align:start position:0% +this alliance becomes the enabling + + + align:start position:0% +this alliance becomes the enabling +conditions for a complex form of social + + align:start position:0% +conditions for a complex form of social + + + align:start position:0% +conditions for a complex form of social +experience and of narrative art. Well, + + align:start position:0% +experience and of narrative art. Well, + + + align:start position:0% +experience and of narrative art. Well, +that paradox is at the heart of a lot of + + align:start position:0% +that paradox is at the heart of a lot of + + + align:start position:0% +that paradox is at the heart of a lot of +what we're we'll be looking at in this + + align:start position:0% +what we're we'll be looking at in this + + + align:start position:0% +what we're we'll be looking at in this +course and I hope you'll keep it in mind + + align:start position:0% +course and I hope you'll keep it in mind + + + align:start position:0% +course and I hope you'll keep it in mind +as we go on. I'd like to say a couple of + + align:start position:0% +as we go on. I'd like to say a couple of + + + align:start position:0% +as we go on. I'd like to say a couple of +words, not too many, a couple of words + + align:start position:0% +words, not too many, a couple of words + + + align:start position:0% +words, not too many, a couple of words +about the um the great train robbery, + + align:start position:0% +about the um the great train robbery, + + + align:start position:0% +about the um the great train robbery, +the very first uh film that you've seen. + + align:start position:0% +the very first uh film that you've seen. + + + align:start position:0% +the very first uh film that you've seen. +uh this the great train robbery is + + align:start position:0% +uh this the great train robbery is + + + align:start position:0% +uh this the great train robbery is +discussed in some helpful detail in + + align:start position:0% +discussed in some helpful detail in + + + align:start position:0% +discussed in some helpful detail in +David Cook's history of narrative film + + align:start position:0% +David Cook's history of narrative film + + + align:start position:0% +David Cook's history of narrative film +and I urge you to look closely at his + + align:start position:0% +and I urge you to look closely at his + + + align:start position:0% +and I urge you to look closely at his +account of it but I want to remind you + + align:start position:0% +account of it but I want to remind you + + + align:start position:0% +account of it but I want to remind you +of about a couple of highlights. One is + + align:start position:0% +of about a couple of highlights. One is + + + align:start position:0% +of about a couple of highlights. One is +that that although the great train + + align:start position:0% +that that although the great train + + + align:start position:0% +that that although the great train +robbery seems very primitive to us, it's + + align:start position:0% +robbery seems very primitive to us, it's + + + align:start position:0% +robbery seems very primitive to us, it's +important to realize that even the great + + align:start position:0% +important to realize that even the great + + + align:start position:0% +important to realize that even the great +train robbery is already a refined text + + align:start position:0% +train robbery is already a refined text + + + align:start position:0% +train robbery is already a refined text +almost most most of the most fundamental + + align:start position:0% +almost most most of the most fundamental + + + align:start position:0% +almost most most of the most fundamental +principles of what we might call the + + align:start position:0% +principles of what we might call the + + + align:start position:0% +principles of what we might call the +syntax or grammar of the movies is + + align:start position:0% +syntax or grammar of the movies is + + + align:start position:0% +syntax or grammar of the movies is +already embedded in the great train + + align:start position:0% +already embedded in the great train + + + align:start position:0% +already embedded in the great train +robbery. And what that means is that the + + align:start position:0% +robbery. And what that means is that the + + + align:start position:0% +robbery. And what that means is that the +period the five or six year period + + align:start position:0% +period the five or six year period + + + align:start position:0% +period the five or six year period +before that when there is all this + + align:start position:0% +before that when there is all this + + + align:start position:0% +before that when there is all this +practice in with non-narrative forms uh + + align:start position:0% +practice in with non-narrative forms uh + + + align:start position:0% +practice in with non-narrative forms uh +lies behind the great train robbery in + + align:start position:0% +lies behind the great train robbery in + + + align:start position:0% +lies behind the great train robbery in +some and what also lies behind the great + + align:start position:0% +some and what also lies behind the great + + + align:start position:0% +some and what also lies behind the great +train robbery is this experience of + + align:start position:0% +train robbery is this experience of + + + align:start position:0% +train robbery is this experience of +audiences going in to the to first to + + align:start position:0% +audiences going in to the to first to + + + align:start position:0% +audiences going in to the to first to +the penny arcades then to the + + align:start position:0% +the penny arcades then to the + + + align:start position:0% +the penny arcades then to the +nickelodeons that begin to open up in + + align:start position:0% +nickelodeons that begin to open up in + + + align:start position:0% +nickelodeons that begin to open up in +the in in the by the turn of the 20th + + align:start position:0% +the in in the by the turn of the 20th + + + align:start position:0% +the in in the by the turn of the 20th +century uh and becoming impatient with + + align:start position:0% +century uh and becoming impatient with + + + align:start position:0% +century uh and becoming impatient with +repeated scenes that simply show uh + + align:start position:0% +repeated scenes that simply show uh + + + align:start position:0% +repeated scenes that simply show uh +jokes uh hoses going off in people's + + align:start position:0% +jokes uh hoses going off in people's + + + align:start position:0% +jokes uh hoses going off in people's +faces or trains coming into a state. + + align:start position:0% +faces or trains coming into a state. + + + align:start position:0% +faces or trains coming into a state. +After a while, the novelty wears off. + + align:start position:0% +After a while, the novelty wears off. + + + align:start position:0% +After a while, the novelty wears off. +The audience wants but of course the + + align:start position:0% +The audience wants but of course the + + + align:start position:0% +The audience wants but of course the +people who are making films are also + + align:start position:0% +people who are making films are also + + + align:start position:0% +people who are making films are also +interested in what they're doing. You + + align:start position:0% +interested in what they're doing. You + + + align:start position:0% +interested in what they're doing. You +can feel especially if you look at DW + + align:start position:0% +can feel especially if you look at DW + + + align:start position:0% +can feel especially if you look at DW +Griffith's shorts and you've looked at + + align:start position:0% +Griffith's shorts and you've looked at + + + align:start position:0% +Griffith's shorts and you've looked at +two you will have looked at two of them + + align:start position:0% +two you will have looked at two of them + + + align:start position:0% +two you will have looked at two of them +in this course uh the uh a beast at bay + + align:start position:0% +in this course uh the uh a beast at bay + + + align:start position:0% +in this course uh the uh a beast at bay +from last time and the lonale operator + + align:start position:0% +from last time and the lonale operator + + + align:start position:0% +from last time and the lonale operator +which you'll see tonight before we turn + + align:start position:0% +which you'll see tonight before we turn + + + align:start position:0% +which you'll see tonight before we turn +to the Keaton films. uh and you'll see + + align:start position:0% +to the Keaton films. uh and you'll see + + + align:start position:0% +to the Keaton films. uh and you'll see +in these are just a sampling of his of + + align:start position:0% +in these are just a sampling of his of + + + align:start position:0% +in these are just a sampling of his of +his early work. But if you look closely + + align:start position:0% +his early work. But if you look closely + + + align:start position:0% +his early work. But if you look closely +at those where you can feel Griffith's + + align:start position:0% +at those where you can feel Griffith's + + + align:start position:0% +at those where you can feel Griffith's +own excitement at discovering the + + align:start position:0% +own excitement at discovering the + + + align:start position:0% +own excitement at discovering the +possibilities of the cinema learn and in + + align:start position:0% +possibilities of the cinema learn and in + + + align:start position:0% +possibilities of the cinema learn and in +many cases these films you Griffith is + + align:start position:0% +many cases these films you Griffith is + + + align:start position:0% +many cases these films you Griffith is +doing what doing some things with the + + align:start position:0% +doing what doing some things with the + + + align:start position:0% +doing what doing some things with the +camera doing some things with narrative + + align:start position:0% +camera doing some things with narrative + + + align:start position:0% +camera doing some things with narrative +shape with the shaping of narrative in + + align:start position:0% +shape with the shaping of narrative in + + + align:start position:0% +shape with the shaping of narrative in +in cinema that had never been done + + align:start position:0% +in cinema that had never been done + + + align:start position:0% +in cinema that had never been done +before and you can feel his own + + align:start position:0% +before and you can feel his own + + + align:start position:0% +before and you can feel his own +excitement at the possibilities of this + + align:start position:0% +excitement at the possibilities of this + + + align:start position:0% +excitement at the possibilities of this +of this astonishing of this astonishing + + align:start position:0% +of this astonishing of this astonishing + + + align:start position:0% +of this astonishing of this astonishing +technology. Well, the great train + + align:start position:0% +technology. Well, the great train + + + align:start position:0% +technology. Well, the great train +robbery, the most important discovery + + align:start position:0% +robbery, the most important discovery + + + align:start position:0% +robbery, the most important discovery +that the great train robbery shows us, + + align:start position:0% +that the great train robbery shows us, + + + align:start position:0% +that the great train robbery shows us, +and again, it seems so obvious and so + + align:start position:0% +and again, it seems so obvious and so + + + align:start position:0% +and again, it seems so obvious and so +embedded that we wouldn't even think + + align:start position:0% +embedded that we wouldn't even think + + + align:start position:0% +embedded that we wouldn't even think +about it today. We've absorbed these + + align:start position:0% +about it today. We've absorbed these + + + align:start position:0% +about it today. We've absorbed these +principles so deeply into our DNA that + + align:start position:0% +principles so deeply into our DNA that + + + align:start position:0% +principles so deeply into our DNA that +we don't even think of we're we're we + + align:start position:0% +we don't even think of we're we're we + + + align:start position:0% +we don't even think of we're we're we +learn how to watch movies in this way + + align:start position:0% +learn how to watch movies in this way + + + align:start position:0% +learn how to watch movies in this way +from the great from the cradle in some + + align:start position:0% +from the great from the cradle in some + + + align:start position:0% +from the great from the cradle in some +ways be because we we're by by the time + + align:start position:0% +ways be because we we're by by the time + + + align:start position:0% +ways be because we we're by by the time +most most people today are five or six + + align:start position:0% +most most people today are five or six + + + align:start position:0% +most most people today are five or six +years old, they've been subjected + + align:start position:0% +years old, they've been subjected + + + align:start position:0% +years old, they've been subjected +probably to more audiovisisual images + + align:start position:0% +probably to more audiovisisual images + + + align:start position:0% +probably to more audiovisisual images +than anyone alive in 1900. And that's + + align:start position:0% +than anyone alive in 1900. And that's + + + align:start position:0% +than anyone alive in 1900. And that's +you know we're we're just cognitively + + align:start position:0% +you know we're we're just cognitively + + + align:start position:0% +you know we're we're just cognitively +different from from the in terms of our + + align:start position:0% +different from from the in terms of our + + + align:start position:0% +different from from the in terms of our +capacity to process audiovisisual + + align:start position:0% +capacity to process audiovisisual + + + align:start position:0% +capacity to process audiovisisual +information. Uh we and but imagine an + + align:start position:0% +information. Uh we and but imagine an + + + align:start position:0% +information. Uh we and but imagine an +audience that's completely illiterate in + + align:start position:0% +audience that's completely illiterate in + + + align:start position:0% +audience that's completely illiterate in +these things that has to learn this + + align:start position:0% +these things that has to learn this + + + align:start position:0% +these things that has to learn this +system as the system itself is evolving. + + align:start position:0% +system as the system itself is evolving. + + + align:start position:0% +system as the system itself is evolving. +That's part of the excitement of looking + + align:start position:0% +That's part of the excitement of looking + + + align:start position:0% +That's part of the excitement of looking +at these at at these early films. And + + align:start position:0% +at these at at these early films. And + + + align:start position:0% +at these at at these early films. And +the most important discovery in the in + + align:start position:0% +the most important discovery in the in + + + align:start position:0% +the most important discovery in the in +the great train robbery is the discovery + + align:start position:0% +the great train robbery is the discovery + + + align:start position:0% +the great train robbery is the discovery +that the shot the single the single + + align:start position:0% +that the shot the single the single + + + align:start position:0% +that the shot the single the single +uncut shot of film however long it lasts + + align:start position:0% +uncut shot of film however long it lasts + + + align:start position:0% +uncut shot of film however long it lasts +and its length is dependent on on the + + align:start position:0% +and its length is dependent on on the + + + align:start position:0% +and its length is dependent on on the +decision you make about when to edit it + + align:start position:0% +decision you make about when to edit it + + + align:start position:0% +decision you make about when to edit it +right uh so it can it can go on for a + + align:start position:0% +right uh so it can it can go on for a + + + align:start position:0% +right uh so it can it can go on for a +long time or it can be very short and + + align:start position:0% +long time or it can be very short and + + + align:start position:0% +long time or it can be very short and +and the length or the shortness of a of + + align:start position:0% +and the length or the shortness of a of + + + align:start position:0% +and the length or the shortness of a of +of of cuts also affects sort of the + + align:start position:0% +of of cuts also affects sort of the + + + align:start position:0% +of of cuts also affects sort of the +rhythm of your experience in the film. + + align:start position:0% +rhythm of your experience in the film. + + + align:start position:0% +rhythm of your experience in the film. +This is something that you can see + + align:start position:0% +This is something that you can see + + + align:start position:0% +This is something that you can see +Griffith practicing with even as as as + + align:start position:0% +Griffith practicing with even as as as + + + align:start position:0% +Griffith practicing with even as as as +early as a beast at bay. If you think + + align:start position:0% +early as a beast at bay. If you think + + + align:start position:0% +early as a beast at bay. If you think +about the great climax of the beast at + + align:start position:0% +about the great climax of the beast at + + + align:start position:0% +about the great climax of the beast at +bay where you have the where you have + + align:start position:0% +bay where you have the where you have + + + align:start position:0% +bay where you have the where you have +the uh uh um + + align:start position:0% +the uh uh um + + + align:start position:0% +the uh uh um +uh the woman the woman being threatened + + align:start position:0% +uh the woman the woman being threatened + + + align:start position:0% +uh the woman the woman being threatened +but you also have this sort of this sort + + align:start position:0% +but you also have this sort of this sort + + + align:start position:0% +but you also have this sort of this sort +of race in the automobile to try to to + + align:start position:0% +of race in the automobile to try to to + + + align:start position:0% +of race in the automobile to try to to +try to get there on time and then and + + align:start position:0% +try to get there on time and then and + + + align:start position:0% +try to get there on time and then and +then the race to rescue her by a variety + + align:start position:0% +then the race to rescue her by a variety + + + align:start position:0% +then the race to rescue her by a variety +of people. You could what what Griffith + + align:start position:0% +of people. You could what what Griffith + + + align:start position:0% +of people. You could what what Griffith +does is he cuts back and forth. He + + align:start position:0% +does is he cuts back and forth. He + + + align:start position:0% +does is he cuts back and forth. He +creates the principle of parallel + + align:start position:0% +creates the principle of parallel + + + align:start position:0% +creates the principle of parallel +action. What he realized, what he + + align:start position:0% +action. What he realized, what he + + + align:start position:0% +action. What he realized, what he +discovered was that the audience will + + align:start position:0% +discovered was that the audience will + + + align:start position:0% +discovered was that the audience will +recognize this kind of cutting as + + align:start position:0% +recognize this kind of cutting as + + + align:start position:0% +recognize this kind of cutting as +showing you simultaneity, showing you + + align:start position:0% +showing you simultaneity, showing you + + + align:start position:0% +showing you simultaneity, showing you +things that are going on at the same + + align:start position:0% +things that are going on at the same + + + align:start position:0% +things that are going on at the same +time. In other words, what he what he + + align:start position:0% +time. In other words, what he what he + + + align:start position:0% +time. In other words, what he what he +discovered were in a certain sense how + + align:start position:0% +discovered were in a certain sense how + + + align:start position:0% +discovered were in a certain sense how +the mind how how we would cognitively + + align:start position:0% +the mind how how we would cognitively + + + align:start position:0% +the mind how how we would cognitively +process certain kinds of gestures on + + align:start position:0% +process certain kinds of gestures on + + + align:start position:0% +process certain kinds of gestures on +film. And what he discovered, of course, + + align:start position:0% +film. And what he discovered, of course, + + + align:start position:0% +film. And what he discovered, of course, +is that if he cuts, if he edits more + + align:start position:0% +is that if he cuts, if he edits more + + + align:start position:0% +is that if he cuts, if he edits more +quickly, if he creates a fast rhythm, he + + align:start position:0% +quickly, if he creates a fast rhythm, he + + + align:start position:0% +quickly, if he creates a fast rhythm, he +creates excitement. And if he create and + + align:start position:0% +creates excitement. And if he create and + + + align:start position:0% +creates excitement. And if he create and +what he began to discover was something + + align:start position:0% +what he began to discover was something + + + align:start position:0% +what he began to discover was something +that in later directors like Hitchcock + + align:start position:0% +that in later directors like Hitchcock + + + align:start position:0% +that in later directors like Hitchcock +would carry to to an almost evil pitch a + + align:start position:0% +would carry to to an almost evil pitch a + + + align:start position:0% +would carry to to an almost evil pitch a +capacity to manipulate and control the + + align:start position:0% +capacity to manipulate and control the + + + align:start position:0% +capacity to manipulate and control the +audience's reaction by the speed with + + align:start position:0% +audience's reaction by the speed with + + + align:start position:0% +audience's reaction by the speed with +which particular images appear or + + align:start position:0% +which particular images appear or + + + align:start position:0% +which particular images appear or +disappear. So so Griffith even at this + + align:start position:0% +disappear. So so Griffith even at this + + + align:start position:0% +disappear. So so Griffith even at this +early stage you can see Griffith + + align:start position:0% +early stage you can see Griffith + + + align:start position:0% +early stage you can see Griffith +discovering important principles. The + + align:start position:0% +discovering important principles. The + + + align:start position:0% +discovering important principles. The +most fundamental principle in a great + + align:start position:0% +most fundamental principle in a great + + + align:start position:0% +most fundamental principle in a great +train robbery which is not a Griffith + + align:start position:0% +train robbery which is not a Griffith + + + align:start position:0% +train robbery which is not a Griffith +film and precedes Griffith is the + + align:start position:0% +film and precedes Griffith is the + + + align:start position:0% +film and precedes Griffith is the +discovery that the shot is the basic + + align:start position:0% +discovery that the shot is the basic + + + align:start position:0% +discovery that the shot is the basic +unit of action. Why is that a great + + align:start position:0% +unit of action. Why is that a great + + + align:start position:0% +unit of action. Why is that a great +discovery? Well, if you think of the if + + align:start position:0% +discovery? Well, if you think of the if + + + align:start position:0% +discovery? Well, if you think of the if +you think of the movies as as a a as a + + align:start position:0% +you think of the movies as as a a as a + + + align:start position:0% +you think of the movies as as a a as a +device or as a as a as a medium that + + align:start position:0% +device or as a as a as a medium that + + + align:start position:0% +device or as a as a as a medium that +grows out of especially a theatrical + + align:start position:0% +grows out of especially a theatrical + + + align:start position:0% +grows out of especially a theatrical +dispensation grows out of other things + + align:start position:0% +dispensation grows out of other things + + + align:start position:0% +dispensation grows out of other things +as well. Novels feed into it. Visual art + + align:start position:0% +as well. Novels feed into it. Visual art + + + align:start position:0% +as well. Novels feed into it. Visual art +feeds into the movies. But it's + + align:start position:0% +feeds into the movies. But it's + + + align:start position:0% +feeds into the movies. But it's +certainly true that most of the major + + align:start position:0% +certainly true that most of the major + + + align:start position:0% +certainly true that most of the major +sort of ways in which directors first + + align:start position:0% +sort of ways in which directors first + + + align:start position:0% +sort of ways in which directors first +conceived how to think about the + + align:start position:0% +conceived how to think about the + + + align:start position:0% +conceived how to think about the +experience of what's of what the camera + + align:start position:0% +experience of what's of what the camera + + + align:start position:0% +experience of what's of what the camera +is looking at, they would they would + + align:start position:0% +is looking at, they would they would + + + align:start position:0% +is looking at, they would they would +have been influenced by their own + + align:start position:0% +have been influenced by their own + + + align:start position:0% +have been influenced by their own +experience of theater. And if you think + + align:start position:0% +experience of theater. And if you think + + + align:start position:0% +experience of theater. And if you think +about it for a moment, what you can see + + align:start position:0% +about it for a moment, what you can see + + + align:start position:0% +about it for a moment, what you can see +even in the great train robbery and uh + + align:start position:0% +even in the great train robbery and uh + + + align:start position:0% +even in the great train robbery and uh +the an impulse to treat the camera as a + + align:start position:0% +the an impulse to treat the camera as a + + + align:start position:0% +the an impulse to treat the camera as a +stable thing, the camera doesn't move + + align:start position:0% +stable thing, the camera doesn't move + + + align:start position:0% +stable thing, the camera doesn't move +very the camera the there are panning + + align:start position:0% +very the camera the there are panning + + + align:start position:0% +very the camera the there are panning +shots in which the camera will go like + + align:start position:0% +shots in which the camera will go like + + + align:start position:0% +shots in which the camera will go like +this, right? But the camera will not + + align:start position:0% +this, right? But the camera will not + + + align:start position:0% +this, right? But the camera will not +track. It will not move back and forth + + align:start position:0% +track. It will not move back and forth + + + align:start position:0% +track. It will not move back and forth +or sideways off its off its in in the + + align:start position:0% +or sideways off its off its in in the + + + align:start position:0% +or sideways off its off its in in the +great train robbery. It's that's a + + align:start position:0% +great train robbery. It's that's a + + + align:start position:0% +great train robbery. It's that's a +discover that's a discovery that + + align:start position:0% +discover that's a discovery that + + + align:start position:0% +discover that's a discovery that +Griffith is going to make and will + + align:start position:0% +Griffith is going to make and will + + + align:start position:0% +Griffith is going to make and will +exploit. Uh and you can see it in in in + + align:start position:0% +exploit. Uh and you can see it in in in + + + align:start position:0% +exploit. Uh and you can see it in in in +a beast at bay. But in the great train + + align:start position:0% +a beast at bay. But in the great train + + + align:start position:0% +a beast at bay. But in the great train +robbery, we haven't got that far yet. + + align:start position:0% +robbery, we haven't got that far yet. + + + align:start position:0% +robbery, we haven't got that far yet. +But what we have discovered, what what + + align:start position:0% +But what we have discovered, what what + + + align:start position:0% +But what we have discovered, what what +Porter, Edwin Porter did discover was + + align:start position:0% +Porter, Edwin Porter did discover was + + + align:start position:0% +Porter, Edwin Porter did discover was +that the shot is the basic unit of + + align:start position:0% +that the shot is the basic unit of + + + align:start position:0% +that the shot is the basic unit of +action. And that and what this means is + + align:start position:0% +action. And that and what this means is + + + align:start position:0% +action. And that and what this means is +it's not simply what the camera sees, + + align:start position:0% +it's not simply what the camera sees, + + + align:start position:0% +it's not simply what the camera sees, +but then how the shots are edited + + align:start position:0% +but then how the shots are edited + + + align:start position:0% +but then how the shots are edited +afterwards that is so crucial. So what + + align:start position:0% +afterwards that is so crucial. So what + + + align:start position:0% +afterwards that is so crucial. So what +it what it came to understand was that + + align:start position:0% +it what it came to understand was that + + + align:start position:0% +it what it came to understand was that +the making of of any movie is always a + + align:start position:0% +the making of of any movie is always a + + + align:start position:0% +the making of of any movie is always a +two-stage process. There's the shooting + + align:start position:0% +two-stage process. There's the shooting + + + align:start position:0% +two-stage process. There's the shooting +of the film and then there's the editing + + align:start position:0% +of the film and then there's the editing + + + align:start position:0% +of the film and then there's the editing +of the film. Right? And that that itself + + align:start position:0% +of the film. Right? And that that itself + + + align:start position:0% +of the film. Right? And that that itself +is a fundamental disc. But the idea that + + align:start position:0% +is a fundamental disc. But the idea that + + + align:start position:0% +is a fundamental disc. But the idea that +the shot is the unit of action instead + + align:start position:0% +the shot is the unit of action instead + + + align:start position:0% +the shot is the unit of action instead +of the scene was hard for movie makers + + align:start position:0% +of the scene was hard for movie makers + + + align:start position:0% +of the scene was hard for movie makers +to get because and what they would do + + align:start position:0% +to get because and what they would do + + + align:start position:0% +to get because and what they would do +they would set the camera up and then + + align:start position:0% +they would set the camera up and then + + + align:start position:0% +they would set the camera up and then +actors would walk in front of the + + align:start position:0% +actors would walk in front of the + + + align:start position:0% +actors would walk in front of the +camera. They would do what they had to + + align:start position:0% +camera. They would do what they had to + + + align:start position:0% +camera. They would do what they had to +do and they would walk off. What's going + + align:start position:0% +do and they would walk off. What's going + + + align:start position:0% +do and they would walk off. What's going +on there? They're conceiving of + + align:start position:0% +on there? They're conceiving of + + + align:start position:0% +on there? They're conceiving of +cinematic space in theatrical terms. As + + align:start position:0% +cinematic space in theatrical terms. As + + + align:start position:0% +cinematic space in theatrical terms. As +soon as the camera is liberated, taken + + align:start position:0% +soon as the camera is liberated, taken + + + align:start position:0% +soon as the camera is liberated, taken +off its tripod, moved around in some + + align:start position:0% +off its tripod, moved around in some + + + align:start position:0% +off its tripod, moved around in some +way, uh allowed to back up or or or come + + align:start position:0% +way, uh allowed to back up or or or come + + + align:start position:0% +way, uh allowed to back up or or or come +close, even allowed to move laterally or + + align:start position:0% +close, even allowed to move laterally or + + + align:start position:0% +close, even allowed to move laterally or +uh uh what we're beginning to do was to + + align:start position:0% +uh uh what we're beginning to do was to + + + align:start position:0% +uh uh what we're beginning to do was to +explore more systematically what the + + align:start position:0% +explore more systematically what the + + + align:start position:0% +explore more systematically what the +camera's unique features are. How the + + align:start position:0% +camera's unique features are. How the + + + align:start position:0% +camera's unique features are. How the +theater is different from the movies, + + align:start position:0% +theater is different from the movies, + + + align:start position:0% +theater is different from the movies, +how how how certain effects are possible + + align:start position:0% +how how how certain effects are possible + + + align:start position:0% +how how how certain effects are possible +in the movies that would not be possible + + align:start position:0% +in the movies that would not be possible + + + align:start position:0% +in the movies that would not be possible +in the theater. When you watch the + + align:start position:0% +in the theater. When you watch the + + + align:start position:0% +in the theater. When you watch the +Keaton films that you're going to see + + align:start position:0% +Keaton films that you're going to see + + + align:start position:0% +Keaton films that you're going to see +tonight, watch for the ways in which + + align:start position:0% +tonight, watch for the ways in which + + + align:start position:0% +tonight, watch for the ways in which +Keaton repeatedly sets up situations so + + align:start position:0% +Keaton repeatedly sets up situations so + + + align:start position:0% +Keaton repeatedly sets up situations so +that such that when you see a particular + + align:start position:0% +that such that when you see a particular + + + align:start position:0% +that such that when you see a particular +gag of his, a joke, what you realize is + + align:start position:0% +gag of his, a joke, what you realize is + + + align:start position:0% +gag of his, a joke, what you realize is +that the joke could not have happened in + + align:start position:0% +that the joke could not have happened in + + + align:start position:0% +that the joke could not have happened in +the theater. It could not have been told + + align:start position:0% +the theater. It could not have been told + + + align:start position:0% +the theater. It could not have been told +to you verbally. The joke is visual. The + + align:start position:0% +to you verbally. The joke is visual. The + + + align:start position:0% +to you verbally. The joke is visual. The +joke involves motion. the the joke in + + align:start position:0% +joke involves motion. the the joke in + + + align:start position:0% +joke involves motion. the the joke in +the joke involves uh a recognition of + + align:start position:0% +the joke involves uh a recognition of + + + align:start position:0% +the joke involves uh a recognition of +the powers of the s of the powers of of + + align:start position:0% +the powers of the s of the powers of of + + + align:start position:0% +the powers of the s of the powers of of +of cinematic representation to tell + + align:start position:0% +of cinematic representation to tell + + + align:start position:0% +of cinematic representation to tell +stories. Uh and there you'll see many + + align:start position:0% +stories. Uh and there you'll see many + + + align:start position:0% +stories. Uh and there you'll see many +examples of this in the in the in the uh + + align:start position:0% +examples of this in the in the in the uh + + + align:start position:0% +examples of this in the in the in the uh +Katon materials that you'll that you'll + + align:start position:0% +Katon materials that you'll that you'll + + + align:start position:0% +Katon materials that you'll that you'll +be looking at tonight. So the so the one + + align:start position:0% +be looking at tonight. So the so the one + + + align:start position:0% +be looking at tonight. So the so the one +of the very first discoveries that's + + align:start position:0% +of the very first discoveries that's + + + align:start position:0% +of the very first discoveries that's +made is the discovery that the shot is + + align:start position:0% +made is the discovery that the shot is + + + align:start position:0% +made is the discovery that the shot is +the basic unit of action. Uh a second + + align:start position:0% +the basic unit of action. Uh a second + + + align:start position:0% +the basic unit of action. Uh a second +discovery is the recognition that you + + align:start position:0% +discovery is the recognition that you + + + align:start position:0% +discovery is the recognition that you +have to cut between scenes. You do your + + align:start position:0% +have to cut between scenes. You do your + + + align:start position:0% +have to cut between scenes. You do your +editing between shots rather rather than + + align:start position:0% +editing between shots rather rather than + + + align:start position:0% +editing between shots rather rather than +and that mo and mostly what you do is + + align:start position:0% +and that mo and mostly what you do is + + + align:start position:0% +and that mo and mostly what you do is +you let scenes play out even though you + + align:start position:0% +you let scenes play out even though you + + + align:start position:0% +you let scenes play out even though you +might abruptly cut a scene before the + + align:start position:0% +might abruptly cut a scene before the + + + align:start position:0% +might abruptly cut a scene before the +action is completed. One of that's + + align:start position:0% +action is completed. One of that's + + + align:start position:0% +action is completed. One of that's +another discovery that was made. If you + + align:start position:0% +another discovery that was made. If you + + + align:start position:0% +another discovery that was made. If you +cut the scene if a person starts to walk + + align:start position:0% +cut the scene if a person starts to walk + + + align:start position:0% +cut the scene if a person starts to walk +toward the door the first earliest films + + align:start position:0% +toward the door the first earliest films + + + align:start position:0% +toward the door the first earliest films +they would show the person walking all + + align:start position:0% +they would show the person walking all + + + align:start position:0% +they would show the person walking all +the way to the end walking out of the + + align:start position:0% +the way to the end walking out of the + + + align:start position:0% +the way to the end walking out of the +door. Then filmmakers discovered, wait a + + align:start position:0% +door. Then filmmakers discovered, wait a + + + align:start position:0% +door. Then filmmakers discovered, wait a +minute, there's a way of creating a kind + + align:start position:0% +minute, there's a way of creating a kind + + + align:start position:0% +minute, there's a way of creating a kind +of quickness here. Because if I show + + align:start position:0% +of quickness here. Because if I show + + + align:start position:0% +of quickness here. Because if I show +Thorburn walking toward the door, + + align:start position:0% +Thorburn walking toward the door, + + + align:start position:0% +Thorburn walking toward the door, +starting and I cut and he knocks his + + align:start position:0% +starting and I cut and he knocks his + + + align:start position:0% +starting and I cut and he knocks his +glasses off. Uh, and then I and then I + + align:start position:0% +glasses off. Uh, and then I and then I + + + align:start position:0% +glasses off. Uh, and then I and then I +cut and I wait till he gets to the door + + align:start position:0% +cut and I wait till he gets to the door + + + align:start position:0% +cut and I wait till he gets to the door +and we see him leaving the door. I don't + + align:start position:0% +and we see him leaving the door. I don't + + + align:start position:0% +and we see him leaving the door. I don't +have to watch him take those 17 steps + + align:start position:0% +have to watch him take those 17 steps + + + align:start position:0% +have to watch him take those 17 steps +that Right. So what what what's been + + align:start position:0% +that Right. So what what what's been + + + align:start position:0% +that Right. So what what what's been +discovered is a basic principle of + + align:start position:0% +discovered is a basic principle of + + + align:start position:0% +discovered is a basic principle of +cinematic syntax, right? You know, but + + align:start position:0% +cinematic syntax, right? You know, but + + + align:start position:0% +cinematic syntax, right? You know, but +what but but it seems so obvious to us, + + align:start position:0% +what but but it seems so obvious to us, + + + align:start position:0% +what but but it seems so obvious to us, +but of course it's really a great + + align:start position:0% +but of course it's really a great + + + align:start position:0% +but of course it's really a great +discovery. It's a uh in other words, the + + align:start position:0% +discovery. It's a uh in other words, the + + + align:start position:0% +discovery. It's a uh in other words, the +the properties of the medium have to be + + align:start position:0% +the properties of the medium have to be + + + align:start position:0% +the properties of the medium have to be +understood before you can really begin + + align:start position:0% +understood before you can really begin + + + align:start position:0% +understood before you can really begin +to exploit it. And that's why uh I've + + align:start position:0% +to exploit it. And that's why uh I've + + + align:start position:0% +to exploit it. And that's why uh I've +asked you to look at some of these short + + align:start position:0% +asked you to look at some of these short + + + align:start position:0% +asked you to look at some of these short +films. None of the short films I've + + align:start position:0% +films. None of the short films I've + + + align:start position:0% +films. None of the short films I've +shown you are completely without uh some + + align:start position:0% +shown you are completely without uh some + + + align:start position:0% +shown you are completely without uh some +uh uh technical interest. And uh even + + align:start position:0% +uh uh technical interest. And uh even + + + align:start position:0% +uh uh technical interest. And uh even +though of course they're the only films + + align:start position:0% +though of course they're the only films + + + align:start position:0% +though of course they're the only films +I'm showing you that I wouldn't sort of + + align:start position:0% +I'm showing you that I wouldn't sort of + + + align:start position:0% +I'm showing you that I wouldn't sort of +make arguments uh to defend them as + + align:start position:0% +make arguments uh to defend them as + + + align:start position:0% +make arguments uh to defend them as +works of art, but I certainly would make + + align:start position:0% +works of art, but I certainly would make + + + align:start position:0% +works of art, but I certainly would make +arguments for them as technically + + align:start position:0% +arguments for them as technically + + + align:start position:0% +arguments for them as technically +fascinating documents. And I hope you'll + + align:start position:0% +fascinating documents. And I hope you'll + + + align:start position:0% +fascinating documents. And I hope you'll +I hope you'll look at them in in that + + align:start position:0% +I hope you'll look at them in in that + + + align:start position:0% +I hope you'll look at them in in that +light. So the shot as a basic unit of + + align:start position:0% +light. So the shot as a basic unit of + + + align:start position:0% +light. So the shot as a basic unit of +action cutting between scenes and a + + align:start position:0% +action cutting between scenes and a + + + align:start position:0% +action cutting between scenes and a +couple of other things in the in the + + align:start position:0% +couple of other things in the in the + + + align:start position:0% +couple of other things in the in the +that I think are important in the great + + align:start position:0% +that I think are important in the great + + + align:start position:0% +that I think are important in the great +train rob one is that you can see in the + + align:start position:0% +train rob one is that you can see in the + + + align:start position:0% +train rob one is that you can see in the +great train robbery they're beginning to + + align:start position:0% +great train robbery they're beginning to + + + align:start position:0% +great train robbery they're beginning to +discover the value of camera placement. + + align:start position:0% +discover the value of camera placement. + + + align:start position:0% +discover the value of camera placement. +What happens when you place the camera + + align:start position:0% +What happens when you place the camera + + + align:start position:0% +What happens when you place the camera +in a particular position that if the + + align:start position:0% +in a particular position that if the + + + align:start position:0% +in a particular position that if the +camera uh especially if action is coming + + align:start position:0% +camera uh especially if action is coming + + + align:start position:0% +camera uh especially if action is coming +toward the camera if you that you might + + align:start position:0% +toward the camera if you that you might + + + align:start position:0% +toward the camera if you that you might +not want to place the camera directly in + + align:start position:0% +not want to place the camera directly in + + + align:start position:0% +not want to place the camera directly in +front of the action that's coming toward + + align:start position:0% +front of the action that's coming toward + + + align:start position:0% +front of the action that's coming toward +you that something happens if you place + + align:start position:0% +you that something happens if you place + + + align:start position:0% +you that something happens if you place +it slightly up toward it so it can see + + align:start position:0% +it slightly up toward it so it can see + + + align:start position:0% +it slightly up toward it so it can see +it at a slight angle. creates a greater + + align:start position:0% +it at a slight angle. creates a greater + + + align:start position:0% +it at a slight angle. creates a greater +illusion of depth in the image for + + align:start position:0% +illusion of depth in the image for + + + align:start position:0% +illusion of depth in the image for +example and it does other kinds of it + + align:start position:0% +example and it does other kinds of it + + + align:start position:0% +example and it does other kinds of it +lets the action get closer to you before + + align:start position:0% +lets the action get closer to you before + + + align:start position:0% +lets the action get closer to you before +before the uh scene has to be cut. Uh so + + align:start position:0% +before the uh scene has to be cut. Uh so + + + align:start position:0% +before the uh scene has to be cut. Uh so +camera placement is something that you + + align:start position:0% +camera placement is something that you + + + align:start position:0% +camera placement is something that you +can see is is beginning to be learned + + align:start position:0% +can see is is beginning to be learned + + + align:start position:0% +can see is is beginning to be learned +beginning to be mastered in the great in + + align:start position:0% +beginning to be mastered in the great in + + + align:start position:0% +beginning to be mastered in the great in +the great train robbery and f camera or + + align:start position:0% +the great train robbery and f camera or + + + align:start position:0% +the great train robbery and f camera or +c or or camera position. So there are + + align:start position:0% +c or or camera position. So there are + + + align:start position:0% +c or or camera position. So there are +other things and finally one might + + align:start position:0% +other things and finally one might + + + align:start position:0% +other things and finally one might +mention one other thing that again + + align:start position:0% +mention one other thing that again + + + align:start position:0% +mention one other thing that again +establishes a principle that begins that + + align:start position:0% +establishes a principle that begins that + + + align:start position:0% +establishes a principle that begins that +that that then is continued continues in + + align:start position:0% +that that then is continued continues in + + + align:start position:0% +that that then is continued continues in +use for 50 or 75 years and that's the + + align:start position:0% +use for 50 or 75 years and that's the + + + align:start position:0% +use for 50 or 75 years and that's the +principle of the process shot. You can + + align:start position:0% +principle of the process shot. You can + + + align:start position:0% +principle of the process shot. You can +see in the great train robbery that he + + align:start position:0% +see in the great train robbery that he + + + align:start position:0% +see in the great train robbery that he +that some effects have been created by + + align:start position:0% +that some effects have been created by + + + align:start position:0% +that some effects have been created by +tricks that there's a that there's back + + align:start position:0% +tricks that there's a that there's back + + + align:start position:0% +tricks that there's a that there's back +projection going used in that. It's it + + align:start position:0% +projection going used in that. It's it + + + align:start position:0% +projection going used in that. It's it +looks crude to us. We can see through + + align:start position:0% +looks crude to us. We can see through + + + align:start position:0% +looks crude to us. We can see through +it, but the early audiences would would + + align:start position:0% +it, but the early audiences would would + + + align:start position:0% +it, but the early audiences would would +not have recognized that. We we're so + + align:start position:0% +not have recognized that. We we're so + + + align:start position:0% +not have recognized that. We we're so +used to location filming that we can + + align:start position:0% +used to location filming that we can + + + align:start position:0% +used to location filming that we can +pick out uh we today can see through the + + align:start position:0% +pick out uh we today can see through the + + + align:start position:0% +pick out uh we today can see through the +process shots of earlier films. Th this + + align:start position:0% +process shots of earlier films. Th this + + + align:start position:0% +process shots of earlier films. Th this +in fact damages some of Hitchcock's + + align:start position:0% +in fact damages some of Hitchcock's + + + align:start position:0% +in fact damages some of Hitchcock's +films very badly today because Hitchcock + + align:start position:0% +films very badly today because Hitchcock + + + align:start position:0% +films very badly today because Hitchcock +used a lot of processed shot effects in + + align:start position:0% +used a lot of processed shot effects in + + + align:start position:0% +used a lot of processed shot effects in +his films. When he made them the + + align:start position:0% +his films. When he made them the + + + align:start position:0% +his films. When he made them the +audiences were used to there was a + + align:start position:0% +audiences were used to there was a + + + align:start position:0% +audiences were used to there was a +convention of film going today + + align:start position:0% +convention of film going today + + + align:start position:0% +convention of film going today +everything because cameras are so much + + align:start position:0% +everything because cameras are so much + + + align:start position:0% +everything because cameras are so much +more more mobile and light and so so + + align:start position:0% +more more mobile and light and so so + + + align:start position:0% +more more mobile and light and so so +much has been uh learned about how to + + align:start position:0% +much has been uh learned about how to + + + align:start position:0% +much has been uh learned about how to +even about filming in in low light and + + align:start position:0% +even about filming in in low light and + + + align:start position:0% +even about filming in in low light and +so forth that they that + + align:start position:0% +so forth that they that + + + align:start position:0% +so forth that they that +there's much less use of process shots. + + align:start position:0% +there's much less use of process shots. + + + align:start position:0% +there's much less use of process shots. +So, well, a new kind of process shot, I + + align:start position:0% +So, well, a new kind of process shot, I + + + align:start position:0% +So, well, a new kind of process shot, I +suppose, is emerging with digital + + align:start position:0% +suppose, is emerging with digital + + + align:start position:0% +suppose, is emerging with digital +animation. And one could say it's sort + + align:start position:0% +animation. And one could say it's sort + + + align:start position:0% +animation. And one could say it's sort +of a return to the idea of manipulating + + align:start position:0% +of a return to the idea of manipulating + + + align:start position:0% +of a return to the idea of manipulating +the image in illegitimate ways. Um, but + + align:start position:0% +the image in illegitimate ways. Um, but + + + align:start position:0% +the image in illegitimate ways. Um, but +the but but we can see even in the great + + align:start position:0% +the but but we can see even in the great + + + align:start position:0% +the but but we can see even in the great +train robbery, we we can even see the + + align:start position:0% +train robbery, we we can even see the + + + align:start position:0% +train robbery, we we can even see the +beginnings of the use of process shots + + align:start position:0% +beginnings of the use of process shots + + + align:start position:0% +beginnings of the use of process shots +of recognizing that you can create + + align:start position:0% +of recognizing that you can create + + + align:start position:0% +of recognizing that you can create +effects in the movies that are unique + + align:start position:0% +effects in the movies that are unique + + + align:start position:0% +effects in the movies that are unique +and special that no other medium would + + align:start position:0% +and special that no other medium would + + + align:start position:0% +and special that no other medium would +allow you to do. And what's embedded + + align:start position:0% +allow you to do. And what's embedded + + + align:start position:0% +allow you to do. And what's embedded +there is science fiction. What's + + align:start position:0% +there is science fiction. What's + + + align:start position:0% +there is science fiction. What's +embedded there are all the kinds of + + align:start position:0% +embedded there are all the kinds of + + + align:start position:0% +embedded there are all the kinds of +imaginative not just science fictional + + align:start position:0% +imaginative not just science fictional + + + align:start position:0% +imaginative not just science fictional +all the kinds of imaginative movies that + + align:start position:0% +all the kinds of imaginative movies that + + + align:start position:0% +all the kinds of imaginative movies that +have been made that maybe take you + + align:start position:0% +have been made that maybe take you + + + align:start position:0% +have been made that maybe take you +inside people's nightmares or dreams + + align:start position:0% +inside people's nightmares or dreams + + + align:start position:0% +inside people's nightmares or dreams +where what the film is showing you now + + align:start position:0% +where what the film is showing you now + + + align:start position:0% +where what the film is showing you now +what in words what what is embedded in + + align:start position:0% +what in words what what is embedded in + + + align:start position:0% +what in words what what is embedded in +that process shot even more fully + + align:start position:0% +that process shot even more fully + + + align:start position:0% +that process shot even more fully +embedded in in Melier's the French + + align:start position:0% +embedded in in Melier's the French + + + align:start position:0% +embedded in in Melier's the French +director's films like trip to the moon + + align:start position:0% +director's films like trip to the moon + + + align:start position:0% +director's films like trip to the moon +where he explicitly goes into a realm of + + align:start position:0% +where he explicitly goes into a realm of + + + align:start position:0% +where he explicitly goes into a realm of +fantasy is not only that the film is the + + align:start position:0% +fantasy is not only that the film is the + + + align:start position:0% +fantasy is not only that the film is the +most profoundly realistic medium that + + align:start position:0% +most profoundly realistic medium that + + + align:start position:0% +most profoundly realistic medium that +was ever invented it may also be the + + align:start position:0% +was ever invented it may also be the + + + align:start position:0% +was ever invented it may also be the +most the the the the most expressive + + align:start position:0% +most the the the the most expressive + + + align:start position:0% +most the the the the most expressive +medium for the for the rendering of + + align:start position:0% +medium for the for the rendering of + + + align:start position:0% +medium for the for the rendering of +non-realistic states of dream, of + + align:start position:0% +non-realistic states of dream, of + + + align:start position:0% +non-realistic states of dream, of +nightmare, of fantasy. Uh exactly be be + + align:start position:0% +nightmare, of fantasy. Uh exactly be be + + + align:start position:0% +nightmare, of fantasy. Uh exactly be be +because of the freedom that that uh the + + align:start position:0% +because of the freedom that that uh the + + + align:start position:0% +because of the freedom that that uh the +film medium allows. And it even these + + align:start position:0% +film medium allows. And it even these + + + align:start position:0% +film medium allows. And it even these +implications are at least embedded in + + align:start position:0% +implications are at least embedded in + + + align:start position:0% +implications are at least embedded in +the use of the process shots in uh + + align:start position:0% +the use of the process shots in uh + + + align:start position:0% +the use of the process shots in uh +Porter's The Great Train Robbery. The + + align:start position:0% +Porter's The Great Train Robbery. The + + + align:start position:0% +Porter's The Great Train Robbery. The +the the other short that you're going to + + align:start position:0% +the the other short that you're going to + + + align:start position:0% +the the other short that you're going to +see tonight that is not by Katon is + + align:start position:0% +see tonight that is not by Katon is + + + align:start position:0% +see tonight that is not by Katon is +called the Lonale Operator. It's it was + + align:start position:0% +called the Lonale Operator. It's it was + + + align:start position:0% +called the Lonale Operator. It's it was +made in 1911. + + align:start position:0% +made in 1911. + + + align:start position:0% +made in 1911. +Um and uh it in a way it's the most it's + + align:start position:0% +Um and uh it in a way it's the most it's + + + align:start position:0% +Um and uh it in a way it's the most it's +the most advanced film of its time. And + + align:start position:0% +the most advanced film of its time. And + + + align:start position:0% +the most advanced film of its time. And +that that's one re and I what I hope + + align:start position:0% +that that's one re and I what I hope + + + align:start position:0% +that that's one re and I what I hope +when you look at it you'll you'll watch + + align:start position:0% +when you look at it you'll you'll watch + + + align:start position:0% +when you look at it you'll you'll watch +especially for how much more complex it + + align:start position:0% +especially for how much more complex it + + + align:start position:0% +especially for how much more complex it +is than let's say the great train + + align:start position:0% +is than let's say the great train + + + align:start position:0% +is than let's say the great train +robbery and it'll be a kind of small + + align:start position:0% +robbery and it'll be a kind of small + + + align:start position:0% +robbery and it'll be a kind of small +measure of this Fredot principle that + + align:start position:0% +measure of this Fredot principle that + + + align:start position:0% +measure of this Fredot principle that +I've been talking about. Let me mention + + align:start position:0% +I've been talking about. Let me mention + + + align:start position:0% +I've been talking about. Let me mention +a couple of things about uh the lonale + + align:start position:0% +a couple of things about uh the lonale + + + align:start position:0% +a couple of things about uh the lonale +operator. Between 1907 and 1911, most + + align:start position:0% +operator. Between 1907 and 1911, most + + + align:start position:0% +operator. Between 1907 and 1911, most +films consisted of no more than 24 + + align:start position:0% +films consisted of no more than 24 + + + align:start position:0% +films consisted of no more than 24 +separate shots. Right. Between 1908 and + + align:start position:0% +separate shots. Right. Between 1908 and + + + align:start position:0% +separate shots. Right. Between 1908 and +1913, led by DW Griffith and his + + align:start position:0% +1913, led by DW Griffith and his + + + align:start position:0% +1913, led by DW Griffith and his +company, the Biograph Company, many more + + align:start position:0% +company, the Biograph Company, many more + + + align:start position:0% +company, the Biograph Company, many more +shots were introduced into in into a + + align:start position:0% +shots were introduced into in into a + + + align:start position:0% +shots were introduced into in into a +single reel of film. And in the Loneale + + align:start position:0% +single reel of film. And in the Loneale + + + align:start position:0% +single reel of film. And in the Loneale +Operator, there are 98 shots, six + + align:start position:0% +Operator, there are 98 shots, six + + + align:start position:0% +Operator, there are 98 shots, six +intertitles, one main title, and two + + align:start position:0% +intertitles, one main title, and two + + + align:start position:0% +intertitles, one main title, and two +written inserts, all within a 17-minute + + align:start position:0% +written inserts, all within a 17-minute + + + align:start position:0% +written inserts, all within a 17-minute +length. Now, think of the just the + + align:start position:0% +length. Now, think of the just the + + + align:start position:0% +length. Now, think of the just the +advent of the the access of complexity + + align:start position:0% +advent of the the access of complexity + + + align:start position:0% +advent of the the access of complexity +that has occurred just in less than 10 + + align:start position:0% +that has occurred just in less than 10 + + + align:start position:0% +that has occurred just in less than 10 +years, right? Uh um + + align:start position:0% +years, right? Uh um + + + align:start position:0% +years, right? Uh um +it's such a complicated film that one of + + align:start position:0% +it's such a complicated film that one of + + + align:start position:0% +it's such a complicated film that one of +the things we realize even looking at + + align:start position:0% +the things we realize even looking at + + + align:start position:0% +the things we realize even looking at +it, if we look closely, is that it + + align:start position:0% +it, if we look closely, is that it + + + align:start position:0% +it, if we look closely, is that it +actually required uh a kind of + + align:start position:0% +actually required uh a kind of + + + align:start position:0% +actually required uh a kind of +attentiveness that earlier films did + + align:start position:0% +attentiveness that earlier films did + + + align:start position:0% +attentiveness that earlier films did +not. As filmmakers began to make these + + align:start position:0% +not. As filmmakers began to make these + + + align:start position:0% +not. As filmmakers began to make these +things and began to make them longer and + + align:start position:0% +things and began to make them longer and + + + align:start position:0% +things and began to make them longer and +began to make them more complicated, + + align:start position:0% +began to make them more complicated, + + + align:start position:0% +began to make them more complicated, +they realized that they couldn't just + + align:start position:0% +they realized that they couldn't just + + + align:start position:0% +they realized that they couldn't just +bring the camera out and start shooting. + + align:start position:0% +bring the camera out and start shooting. + + + align:start position:0% +bring the camera out and start shooting. +They began to develop the the the formal + + align:start position:0% +They began to develop the the the formal + + + align:start position:0% +They began to develop the the the formal +rationalizing strategies that led to the + + align:start position:0% +rationalizing strategies that led to the + + + align:start position:0% +rationalizing strategies that led to the +making of movies as we understand them. + + align:start position:0% +making of movies as we understand them. + + + align:start position:0% +making of movies as we understand them. +There was a 4-day shooting schedule + + align:start position:0% +There was a 4-day shooting schedule + + + align:start position:0% +There was a 4-day shooting schedule +created for the Londonale operator. It + + align:start position:0% +created for the Londonale operator. It + + + align:start position:0% +created for the Londonale operator. It +was one of the first films to to to have + + align:start position:0% +was one of the first films to to to have + + + align:start position:0% +was one of the first films to to to have +uh this format. And of course it's the + + align:start position:0% +uh this format. And of course it's the + + + align:start position:0% +uh this format. And of course it's the +format that is followed today with + + align:start position:0% +format that is followed today with + + + align:start position:0% +format that is followed today with +virtually every film uh in in in + + align:start position:0% +virtually every film uh in in in + + + align:start position:0% +virtually every film uh in in in +different in different uh aspects. Um uh + + align:start position:0% +different in different uh aspects. Um uh + + + align:start position:0% +different in different uh aspects. Um uh +and this also required a pre-planned + + align:start position:0% +and this also required a pre-planned + + + align:start position:0% +and this also required a pre-planned +shooting script. + + align:start position:0% +shooting script. + + + align:start position:0% +shooting script. +They had to they had to plan what they + + align:start position:0% +They had to they had to plan what they + + + align:start position:0% +They had to they had to plan what they +would pre-plan all of their shooting all + + align:start position:0% +would pre-plan all of their shooting all + + + align:start position:0% +would pre-plan all of their shooting all +of their shots all of their camera + + align:start position:0% +of their shots all of their camera + + + align:start position:0% +of their shots all of their camera +angles. They needed a shooting script, a + + align:start position:0% +angles. They needed a shooting script, a + + + align:start position:0% +angles. They needed a shooting script, a +written script. Films didn't have + + align:start position:0% +written script. Films didn't have + + + align:start position:0% +written script. Films didn't have +written scripts at first, but Lonale + + align:start position:0% +written scripts at first, but Lonale + + + align:start position:0% +written scripts at first, but Lonale +did. Uh and it also required in order + + align:start position:0% +did. Uh and it also required in order + + + align:start position:0% +did. Uh and it also required in order +for them to make their schedule out of + + align:start position:0% +for them to make their schedule out of + + + align:start position:0% +for them to make their schedule out of +order shooting. That is to say, they had + + align:start position:0% +order shooting. That is to say, they had + + + align:start position:0% +order shooting. That is to say, they had +to shoot certain things not in the + + align:start position:0% +to shoot certain things not in the + + + align:start position:0% +to shoot certain things not in the +sequential order of the film. And that's + + align:start position:0% +sequential order of the film. And that's + + + align:start position:0% +sequential order of the film. And that's +one of the most basic principles of film + + align:start position:0% +one of the most basic principles of film + + + align:start position:0% +one of the most basic principles of film +making because once you set up the + + align:start position:0% +making because once you set up the + + + align:start position:0% +making because once you set up the +camera for a for a a shot of a + + align:start position:0% +camera for a for a a shot of a + + + align:start position:0% +camera for a for a a shot of a +particular environment, if that + + align:start position:0% +particular environment, if that + + + align:start position:0% +particular environment, if that +environment shows up later in the film, + + align:start position:0% +environment shows up later in the film, + + + align:start position:0% +environment shows up later in the film, +it's unbelievably more expensive and + + align:start position:0% +it's unbelievably more expensive and + + + align:start position:0% +it's unbelievably more expensive and +timeconuming to reconstitute that whole + + align:start position:0% +timeconuming to reconstitute that whole + + + align:start position:0% +timeconuming to reconstitute that whole +set. So they the B almost all films to + + align:start position:0% +set. So they the B almost all films to + + + align:start position:0% +set. So they the B almost all films to +this very day are still shot out of + + align:start position:0% +this very day are still shot out of + + + align:start position:0% +this very day are still shot out of +sequence in order to maximize the the uh + + align:start position:0% +sequence in order to maximize the the uh + + + align:start position:0% +sequence in order to maximize the the uh +uh the the the the the time you have in + + align:start position:0% +uh the the the the the time you have in + + + align:start position:0% +uh the the the the the time you have in +order in in order to work at your most + + align:start position:0% +order in in order to work at your most + + + align:start position:0% +order in in order to work at your most +efficient. In words, it's not an + + align:start position:0% +efficient. In words, it's not an + + + align:start position:0% +efficient. In words, it's not an +efficient way to make a movie to shoot + + align:start position:0% +efficient way to make a movie to shoot + + + align:start position:0% +efficient way to make a movie to shoot +it sequentially to follow the to follow + + align:start position:0% +it sequentially to follow the to follow + + + align:start position:0% +it sequentially to follow the to follow +the script in its chronological + + align:start position:0% +the script in its chronological + + + align:start position:0% +the script in its chronological +sequence. Uh, and the Loneale Operator + + align:start position:0% +sequence. Uh, and the Loneale Operator + + + align:start position:0% +sequence. Uh, and the Loneale Operator +is one of it's maybe the first film to + + align:start position:0% +is one of it's maybe the first film to + + + align:start position:0% +is one of it's maybe the first film to +to have all of these features that we + + align:start position:0% +to have all of these features that we + + + align:start position:0% +to have all of these features that we +would associate with with a mo with with + + align:start position:0% +would associate with with a mo with with + + + align:start position:0% +would associate with with a mo with with +a modern or a contemporary film. Uh, you + + align:start position:0% +a modern or a contemporary film. Uh, you + + + align:start position:0% +a modern or a contemporary film. Uh, you +might notice in the it's a it's an + + align:start position:0% +might notice in the it's a it's an + + + align:start position:0% +might notice in the it's a it's an +immensely complex film even in terms of + + align:start position:0% +immensely complex film even in terms of + + + align:start position:0% +immensely complex film even in terms of +its content and I might leave that I I + + align:start position:0% +its content and I might leave that I I + + + align:start position:0% +its content and I might leave that I I +won't talk about that much now except to + + align:start position:0% +won't talk about that much now except to + + + align:start position:0% +won't talk about that much now except to +say this. Watch the way in which the + + align:start position:0% +say this. Watch the way in which the + + + align:start position:0% +say this. Watch the way in which the +film tries to deal with what we might + + align:start position:0% +film tries to deal with what we might + + + align:start position:0% +film tries to deal with what we might +call uh hierarchies of gender. I mean, + + align:start position:0% +call uh hierarchies of gender. I mean, + + + align:start position:0% +call uh hierarchies of gender. I mean, +the film is partly about how a woman + + align:start position:0% +the film is partly about how a woman + + + align:start position:0% +the film is partly about how a woman +takes on a man's job. I mean, her I + + align:start position:0% +takes on a man's job. I mean, her I + + + align:start position:0% +takes on a man's job. I mean, her I +guess it's her father, isn't it? Her + + align:start position:0% +guess it's her father, isn't it? Her + + + align:start position:0% +guess it's her father, isn't it? Her +father is ill and she has to take over + + align:start position:0% +father is ill and she has to take over + + + align:start position:0% +father is ill and she has to take over +running the the train station and she + + align:start position:0% +running the the train station and she + + + align:start position:0% +running the the train station and she +runs in and and so there's a certain + + align:start position:0% +runs in and and so there's a certain + + + align:start position:0% +runs in and and so there's a certain +sense in which one of the things that's + + align:start position:0% +sense in which one of the things that's + + + align:start position:0% +sense in which one of the things that's +dramatized socially is is a woman sort + + align:start position:0% +dramatized socially is is a woman sort + + + align:start position:0% +dramatized socially is is a woman sort +of moving into a kind of masculine + + align:start position:0% +of moving into a kind of masculine + + + align:start position:0% +of moving into a kind of masculine +realm, taking on a role that's more + + align:start position:0% +realm, taking on a role that's more + + + align:start position:0% +realm, taking on a role that's more +aggressive than is appropriate for for + + align:start position:0% +aggressive than is appropriate for for + + + align:start position:0% +aggressive than is appropriate for for +the for the gender ideologies that are + + align:start position:0% +the for the gender ideologies that are + + + align:start position:0% +the for the gender ideologies that are +dominant. at the end of the 19th century + + align:start position:0% +dominant. at the end of the 19th century + + + align:start position:0% +dominant. at the end of the 19th century +in the United States. But the film is + + align:start position:0% +in the United States. But the film is + + + align:start position:0% +in the United States. But the film is +pretty clever about this like many such + + align:start position:0% +pretty clever about this like many such + + + align:start position:0% +pretty clever about this like many such +popular texts because although it does + + align:start position:0% +popular texts because although it does + + + align:start position:0% +popular texts because although it does +grant this woman a certain kind of + + align:start position:0% +grant this woman a certain kind of + + + align:start position:0% +grant this woman a certain kind of +masculine authority and competence, it + + align:start position:0% +masculine authority and competence, it + + + align:start position:0% +masculine authority and competence, it +also has other things in the film that + + align:start position:0% +also has other things in the film that + + + align:start position:0% +also has other things in the film that +balance that that remind us that she is + + align:start position:0% +balance that that remind us that she is + + + align:start position:0% +balance that that remind us that she is +still nonetheless uh a weak vessel that + + align:start position:0% +still nonetheless uh a weak vessel that + + + align:start position:0% +still nonetheless uh a weak vessel that +she is still a damsel in distress like + + align:start position:0% +she is still a damsel in distress like + + + align:start position:0% +she is still a damsel in distress like +the typical Victorian construction of + + align:start position:0% +the typical Victorian construction of + + + align:start position:0% +the typical Victorian construction of +women. uh in other words what you can + + align:start position:0% +women. uh in other words what you can + + + align:start position:0% +women. uh in other words what you can +see is that the movie exhibits an + + align:start position:0% +see is that the movie exhibits an + + + align:start position:0% +see is that the movie exhibits an +anxiety about gender roles that's also + + align:start position:0% +anxiety about gender roles that's also + + + align:start position:0% +anxiety about gender roles that's also +an anxiety that's resident in the + + align:start position:0% +an anxiety that's resident in the + + + align:start position:0% +an anxiety that's resident in the +society itself uh and I I won't talk + + align:start position:0% +society itself uh and I I won't talk + + + align:start position:0% +society itself uh and I I won't talk +more about this now it's something we + + align:start position:0% +more about this now it's something we + + + align:start position:0% +more about this now it's something we +will develop this aspect of the movies + + align:start position:0% +will develop this aspect of the movies + + + align:start position:0% +will develop this aspect of the movies +the movies as a reflection of social + + align:start position:0% +the movies as a reflection of social + + + align:start position:0% +the movies as a reflection of social +anxieties and social and social problems + + align:start position:0% +anxieties and social and social problems + + + align:start position:0% +anxieties and social and social problems +as the as the course goes on but I do + + align:start position:0% +as the as the course goes on but I do + + + align:start position:0% +as the as the course goes on but I do +want to call your attention to certain + + align:start position:0% +want to call your attention to certain + + + align:start position:0% +want to call your attention to certain +technical things that you can watch to + + align:start position:0% +technical things that you can watch to + + + align:start position:0% +technical things that you can watch to +at least one technical item in the film + + align:start position:0% +at least one technical item in the film + + + align:start position:0% +at least one technical item in the film +it contains what might be called rhyming + + align:start position:0% +it contains what might be called rhyming + + + align:start position:0% +it contains what might be called rhyming +scenes + + align:start position:0% +scenes + + + align:start position:0% +scenes +in which at one point in the film you'll + + align:start position:0% +in which at one point in the film you'll + + + align:start position:0% +in which at one point in the film you'll +see a sequence of scenes and a + + align:start position:0% +see a sequence of scenes and a + + + align:start position:0% +see a sequence of scenes and a +particular shot and then later in the + + align:start position:0% +particular shot and then later in the + + + align:start position:0% +particular shot and then later in the +film almost exactly the same shot will + + align:start position:0% +film almost exactly the same shot will + + + align:start position:0% +film almost exactly the same shot will +reappear and the effect of this of + + align:start position:0% +reappear and the effect of this of + + + align:start position:0% +reappear and the effect of this of +course is to create a sense of coherence + + align:start position:0% +course is to create a sense of coherence + + + align:start position:0% +course is to create a sense of coherence +and a sense of familiarity in the + + align:start position:0% +and a sense of familiarity in the + + + align:start position:0% +and a sense of familiarity in the +audience. It's actually a very subtle + + align:start position:0% +audience. It's actually a very subtle + + + align:start position:0% +audience. It's actually a very subtle +and careful strategy that Griffith + + align:start position:0% +and careful strategy that Griffith + + + align:start position:0% +and careful strategy that Griffith +himself devised. Uh it creates a kind of + + align:start position:0% +himself devised. Uh it creates a kind of + + + align:start position:0% +himself devised. Uh it creates a kind of +continuity and clarity to the whole + + align:start position:0% +continuity and clarity to the whole + + + align:start position:0% +continuity and clarity to the whole +film. Watch for example how the doorway + + align:start position:0% +film. Watch for example how the doorway + + + align:start position:0% +film. Watch for example how the doorway +to the lonale station is photographed + + align:start position:0% +to the lonale station is photographed + + + align:start position:0% +to the lonale station is photographed +when you first see it. how this image + + align:start position:0% +when you first see it. how this image + + + align:start position:0% +when you first see it. how this image +anchors the film's spatial relationships + + align:start position:0% +anchors the film's spatial relationships + + + align:start position:0% +anchors the film's spatial relationships +and how the film has a certain + + align:start position:0% +and how the film has a certain + + + align:start position:0% +and how the film has a certain +trajectory of movement that is repeated + + align:start position:0% +trajectory of movement that is repeated + + + align:start position:0% +trajectory of movement that is repeated +as the film goes on. So that for example + + align:start position:0% +as the film goes on. So that for example + + + align:start position:0% +as the film goes on. So that for example +early in the film we see the heroine go + + align:start position:0% +early in the film we see the heroine go + + + align:start position:0% +early in the film we see the heroine go +from the exterior to the interior of the + + align:start position:0% +from the exterior to the interior of the + + + align:start position:0% +from the exterior to the interior of the +ticket office and then to the inner + + align:start position:0% +ticket office and then to the inner + + + align:start position:0% +ticket office and then to the inner +office of the telegraph operator and we + + align:start position:0% +office of the telegraph operator and we + + + align:start position:0% +office of the telegraph operator and we +see her do this right and then this sets + + align:start position:0% +see her do this right and then this sets + + + align:start position:0% +see her do this right and then this sets +up a kind of basic location and basic + + align:start position:0% +up a kind of basic location and basic + + + align:start position:0% +up a kind of basic location and basic +action for the entire film. It's as if + + align:start position:0% +action for the entire film. It's as if + + + align:start position:0% +action for the entire film. It's as if +what happens in that moment sets up + + align:start position:0% +what happens in that moment sets up + + + align:start position:0% +what happens in that moment sets up +creates a familiarity with the for the + + align:start position:0% +creates a familiarity with the for the + + + align:start position:0% +creates a familiarity with the for the +audience with the sort of geography of + + align:start position:0% +audience with the sort of geography of + + + align:start position:0% +audience with the sort of geography of +the movie because a lot of the action + + align:start position:0% +the movie because a lot of the action + + + align:start position:0% +the movie because a lot of the action +then will depend on our understanding of + + align:start position:0% +then will depend on our understanding of + + + align:start position:0% +then will depend on our understanding of +that geography. And then there are at + + align:start position:0% +that geography. And then there are at + + + align:start position:0% +that geography. And then there are at +least four different times that Griffith + + align:start position:0% +least four different times that Griffith + + + align:start position:0% +least four different times that Griffith +repeats that basic three-shot trajectory + + align:start position:0% +repeats that basic three-shot trajectory + + + align:start position:0% +repeats that basic three-shot trajectory +from the um exterior to the interior of + + align:start position:0% +from the um exterior to the interior of + + + align:start position:0% +from the um exterior to the interior of +the ticket office and then from the + + align:start position:0% +the ticket office and then from the + + + align:start position:0% +the ticket office and then from the +inner to the inner office of the + + align:start position:0% +inner to the inner office of the + + + align:start position:0% +inner to the inner office of the +telegraph operator. It happens four + + align:start position:0% +telegraph operator. It happens four + + + align:start position:0% +telegraph operator. It happens four +times in the film. So it so the film has + + align:start position:0% +times in the film. So it so the film has + + + align:start position:0% +times in the film. So it so the film has +a kind of visual coherence. By the time + + align:start position:0% +a kind of visual coherence. By the time + + + align:start position:0% +a kind of visual coherence. By the time +you come to it the third or fourth time, + + align:start position:0% +you come to it the third or fourth time, + + + align:start position:0% +you come to it the third or fourth time, +it's as if you're intimate with the + + align:start position:0% +it's as if you're intimate with the + + + align:start position:0% +it's as if you're intimate with the +physical geography of the movie. This is + + align:start position:0% +physical geography of the movie. This is + + + align:start position:0% +physical geography of the movie. This is +actually a structural feature that it's + + align:start position:0% +actually a structural feature that it's + + + align:start position:0% +actually a structural feature that it's +easy to miss it, but it's it it's + + align:start position:0% +easy to miss it, but it's it it's + + + align:start position:0% +easy to miss it, but it's it it's +actually very artful and we can see it's + + align:start position:0% +actually very artful and we can see it's + + + align:start position:0% +actually very artful and we can see it's +a it's a mark of how far film has come + + align:start position:0% +a it's a mark of how far film has come + + + align:start position:0% +a it's a mark of how far film has come +even by 1911 that this level of + + align:start position:0% +even by 1911 that this level of + + + align:start position:0% +even by 1911 that this level of +attentiveness uh is is available to us + + align:start position:0% +attentiveness uh is is available to us + + + align:start position:0% +attentiveness uh is is available to us +in the film. There's m much more that + + align:start position:0% +in the film. There's m much more that + + + align:start position:0% +in the film. There's m much more that +could be said about the Loneale + + align:start position:0% +could be said about the Loneale + + + align:start position:0% +could be said about the Loneale +operator, but I will leave it to your + + align:start position:0% +operator, but I will leave it to your + + + align:start position:0% +operator, but I will leave it to your +intelligence and your attentiveness to + + align:start position:0% +intelligence and your attentiveness to + + + align:start position:0% +intelligence and your attentiveness to +try to pick out more thing. And again, + + align:start position:0% +try to pick out more thing. And again, + + + align:start position:0% +try to pick out more thing. And again, +we're only talking about a 17 minute a + + align:start position:0% +we're only talking about a 17 minute a + + + align:start position:0% +we're only talking about a 17 minute a +17-minute film. Well, uh, + + align:start position:0% +17-minute film. Well, uh, + + + align:start position:0% +17-minute film. Well, uh, +Buster Keaton's career could be said in + + align:start position:0% +Buster Keaton's career could be said in + + + align:start position:0% +Buster Keaton's career could be said in +some degree to enact in small the larger + + align:start position:0% +some degree to enact in small the larger + + + align:start position:0% +some degree to enact in small the larger +processes I've been describing. He comes + + align:start position:0% +processes I've been describing. He comes + + + align:start position:0% +processes I've been describing. He comes +into film late and in fact if we were + + align:start position:0% +into film late and in fact if we were + + + align:start position:0% +into film late and in fact if we were +working perfectly chronologically in + + align:start position:0% +working perfectly chronologically in + + + align:start position:0% +working perfectly chronologically in +terms of when Chaplain became a director + + align:start position:0% +terms of when Chaplain became a director + + + align:start position:0% +terms of when Chaplain became a director +he would precede Keaton but I've + + align:start position:0% +he would precede Keaton but I've + + + align:start position:0% +he would precede Keaton but I've +organized the film according to the + + align:start position:0% +organized the film according to the + + + align:start position:0% +organized the film according to the +feature the dates of the feature films + + align:start position:0% +feature the dates of the feature films + + + align:start position:0% +feature the dates of the feature films +and the general is an ear a much a + + align:start position:0% +and the general is an ear a much a + + + align:start position:0% +and the general is an ear a much a +decade earlier than modern times which + + align:start position:0% +decade earlier than modern times which + + + align:start position:0% +decade earlier than modern times which +is the last quote silent film. It's not + + align:start position:0% +is the last quote silent film. It's not + + + align:start position:0% +is the last quote silent film. It's not +really a silent film but it's the last + + align:start position:0% +really a silent film but it's the last + + + align:start position:0% +really a silent film but it's the last +silent film in a deep sense that was + + align:start position:0% +silent film in a deep sense that was + + + align:start position:0% +silent film in a deep sense that was +ever made. It was made in the sound era + + align:start position:0% +ever made. It was made in the sound era + + + align:start position:0% +ever made. It was made in the sound era +in 1936. And when we next week we'll + + align:start position:0% +in 1936. And when we next week we'll + + + align:start position:0% +in 1936. And when we next week we'll +talk more about the implications of that + + align:start position:0% +talk more about the implications of that + + + align:start position:0% +talk more about the implications of that +and why that was a very daring thing for + + align:start position:0% +and why that was a very daring thing for + + + align:start position:0% +and why that was a very daring thing for +Chaplan to do something like almost a + + align:start position:0% +Chaplan to do something like almost a + + + align:start position:0% +Chaplan to do something like almost a +decade after the advent of sound he made + + align:start position:0% +decade after the advent of sound he made + + + align:start position:0% +decade after the advent of sound he made +a movie that essentially had no dialogue + + align:start position:0% +a movie that essentially had no dialogue + + + align:start position:0% +a movie that essentially had no dialogue +in it. So Katon came a little later + + align:start position:0% +in it. So Katon came a little later + + + align:start position:0% +in it. So Katon came a little later +comes into movie making uh after uh a + + align:start position:0% +comes into movie making uh after uh a + + + align:start position:0% +comes into movie making uh after uh a +little a few years after uh uh Chaplain + + align:start position:0% +little a few years after uh uh Chaplain + + + align:start position:0% +little a few years after uh uh Chaplain +but his but his career has a similar + + align:start position:0% +but his but his career has a similar + + + align:start position:0% +but his but his career has a similar +trajectory. He began his career in + + align:start position:0% +trajectory. He began his career in + + + align:start position:0% +trajectory. He began his career in +legitimate theater in vaudeville and in + + align:start position:0% +legitimate theater in vaudeville and in + + + align:start position:0% +legitimate theater in vaudeville and in +and in and in on the performance circuit + + align:start position:0% +and in and in on the performance circuit + + + align:start position:0% +and in and in on the performance circuit +uh and and uh- was an acrobat from a + + align:start position:0% +uh and and uh- was an acrobat from a + + + align:start position:0% +uh and and uh- was an acrobat from a +very young age from the the age of two + + align:start position:0% +very young age from the the age of two + + + align:start position:0% +very young age from the the age of two +or three was in his parents' stage act. + + align:start position:0% +or three was in his parents' stage act. + + + align:start position:0% +or three was in his parents' stage act. +He was actually uh uh uh a and in fact + + align:start position:0% +He was actually uh uh uh a and in fact + + + align:start position:0% +He was actually uh uh uh a and in fact +he learned a lot of his acrobatic feats + + align:start position:0% +he learned a lot of his acrobatic feats + + + align:start position:0% +he learned a lot of his acrobatic feats +on his parents' stage act. one very + + align:start position:0% +on his parents' stage act. one very + + + align:start position:0% +on his parents' stage act. one very +famous uh passage in his his father used + + align:start position:0% +famous uh passage in his his father used + + + align:start position:0% +famous uh passage in his his father used +to take him he was just a young kid + + align:start position:0% +to take him he was just a young kid + + + align:start position:0% +to take him he was just a young kid +three or four years old five years old + + align:start position:0% +three or four years old five years old + + + align:start position:0% +three or four years old five years old +would take him by his legs and swing him + + align:start position:0% +would take him by his legs and swing him + + + align:start position:0% +would take him by his legs and swing him +back and forth like this he had very + + align:start position:0% +back and forth like this he had very + + + align:start position:0% +back and forth like this he had very +long hair and he would sweep the floor + + align:start position:0% +long hair and he would sweep the floor + + + align:start position:0% +long hair and he would sweep the floor +with his hair and then swing him two or + + align:start position:0% +with his hair and then swing him two or + + + align:start position:0% +with his hair and then swing him two or +three times this would happen live he + + align:start position:0% +three times this would happen live he + + + align:start position:0% +three times this would happen live he +would swing him like this and let him go + + align:start position:0% +would swing him like this and let him go + + + align:start position:0% +would swing him like this and let him go +and the kid five years old would fly + + align:start position:0% +and the kid five years old would fly + + + align:start position:0% +and the kid five years old would fly +against the wall and fall down it would + + align:start position:0% +against the wall and fall down it would + + + align:start position:0% +against the wall and fall down it would +look terrible and Katon took later in + + align:start position:0% +look terrible and Katon took later in + + + align:start position:0% +look terrible and Katon took later in +his life Katon talked about this there + + align:start position:0% +his life Katon talked about this there + + + align:start position:0% +his life Katon talked about this there +were actually some cities in which the + + align:start position:0% +were actually some cities in which the + + + align:start position:0% +were actually some cities in which the +the uh uh societies for the for for the + + align:start position:0% +the uh uh societies for the for for the + + + align:start position:0% +the uh uh societies for the for for the +prevention of cruelty to children came + + align:start position:0% +prevention of cruelty to children came + + + align:start position:0% +prevention of cruelty to children came +in and shut down the shut down the act. + + align:start position:0% +in and shut down the shut down the act. + + + align:start position:0% +in and shut down the shut down the act. +Wouldn't allow the act to go on. Not + + align:start position:0% +Wouldn't allow the act to go on. Not + + + align:start position:0% +Wouldn't allow the act to go on. Not +stupid because his father was a drunkard + + align:start position:0% +stupid because his father was a drunkard + + + align:start position:0% +stupid because his father was a drunkard +and sometimes performed drunk. And Katon + + align:start position:0% +and sometimes performed drunk. And Katon + + + align:start position:0% +and sometimes performed drunk. And Katon +was sometimes injured. He was also + + align:start position:0% +was sometimes injured. He was also + + + align:start position:0% +was sometimes injured. He was also +injured when he made his own movies for + + align:start position:0% +injured when he made his own movies for + + + align:start position:0% +injured when he made his own movies for +because he was such a daring acrobat. Uh + + align:start position:0% +because he was such a daring acrobat. Uh + + + align:start position:0% +because he was such a daring acrobat. Uh +and uh Katon recounts that when he first + + align:start position:0% +and uh Katon recounts that when he first + + + align:start position:0% +and uh Katon recounts that when he first +began to perform in this, he would make + + align:start position:0% +began to perform in this, he would make + + + align:start position:0% +began to perform in this, he would make +faces, you know, faces that indicated + + align:start position:0% +faces, you know, faces that indicated + + + align:start position:0% +faces, you know, faces that indicated +pain or happiness or relief when his + + align:start position:0% +pain or happiness or relief when his + + + align:start position:0% +pain or happiness or relief when his +father was manipulating him this way. + + align:start position:0% +father was manipulating him this way. + + + align:start position:0% +father was manipulating him this way. +But he found that the audience responded + + align:start position:0% +But he found that the audience responded + + + align:start position:0% +But he found that the audience responded +much more comically, much more + + align:start position:0% +much more comically, much more + + + align:start position:0% +much more comically, much more +immediately if he just kept his face + + align:start position:0% +immediately if he just kept his face + + + align:start position:0% +immediately if he just kept his face +expressionless. And that's where there + + align:start position:0% +expressionless. And that's where there + + + align:start position:0% +expressionless. And that's where there +developed the probably mistaken uh uh + + align:start position:0% +developed the probably mistaken uh uh + + + align:start position:0% +developed the probably mistaken uh uh +label for Keaton of the great stone + + align:start position:0% +label for Keaton of the great stone + + + align:start position:0% +label for Keaton of the great stone +face. And in his films very often, + + align:start position:0% +face. And in his films very often, + + + align:start position:0% +face. And in his films very often, +you'll see this young man facing + + align:start position:0% +you'll see this young man facing + + + align:start position:0% +you'll see this young man facing +monumental catastrophe. His face will + + align:start position:0% +monumental catastrophe. His face will + + + align:start position:0% +monumental catastrophe. His face will +look out at things without everchanging + + align:start position:0% +look out at things without everchanging + + + align:start position:0% +look out at things without everchanging +expression. And there is something kind + + align:start position:0% +expression. And there is something kind + + + align:start position:0% +expression. And there is something kind +of kind of comical about that. You'll + + align:start position:0% +of kind of comical about that. You'll + + + align:start position:0% +of kind of comical about that. You'll +see some examples of this in the in the + + align:start position:0% +see some examples of this in the in the + + + align:start position:0% +see some examples of this in the in the +general. Well, you'll you'll see in the + + align:start position:0% +general. Well, you'll you'll see in the + + + align:start position:0% +general. Well, you'll you'll see in the +two short films that Keaton began to + + align:start position:0% +two short films that Keaton began to + + + align:start position:0% +two short films that Keaton began to +make that he enters film at already a + + align:start position:0% +make that he enters film at already a + + + align:start position:0% +make that he enters film at already a +relatively sophisticated time and and + + align:start position:0% +relatively sophisticated time and and + + + align:start position:0% +relatively sophisticated time and and +the shorts I'm asking you to look at are + + align:start position:0% +the shorts I'm asking you to look at are + + + align:start position:0% +the shorts I'm asking you to look at are +very interesting uh uh remarkable films + + align:start position:0% +very interesting uh uh remarkable films + + + align:start position:0% +very interesting uh uh remarkable films +in in their own way. And one of the + + align:start position:0% +in in their own way. And one of the + + + align:start position:0% +in in their own way. And one of the +things they teach us and one of the + + align:start position:0% +things they teach us and one of the + + + align:start position:0% +things they teach us and one of the +reasons I want you to look closely at at + + align:start position:0% +reasons I want you to look closely at at + + + align:start position:0% +reasons I want you to look closely at at +at uh Keaton is they te is they show us + + align:start position:0% +at uh Keaton is they te is they show us + + + align:start position:0% +at uh Keaton is they te is they show us +yet again another aspect of what I mean + + align:start position:0% +yet again another aspect of what I mean + + + align:start position:0% +yet again another aspect of what I mean +when I talk about the + + align:start position:0% +when I talk about the + + + align:start position:0% +when I talk about the +Fred principle. this development of + + align:start position:0% +Fred principle. this development of + + + align:start position:0% +Fred principle. this development of +evolution and and and and and increasing + + align:start position:0% +evolution and and and and and increasing + + + align:start position:0% +evolution and and and and and increasing +and increasing complexity because + + align:start position:0% +and increasing complexity because + + + align:start position:0% +and increasing complexity because +if you look at cops or if you look at + + align:start position:0% +if you look at cops or if you look at + + + align:start position:0% +if you look at cops or if you look at +one week what you will see Katon doing + + align:start position:0% +one week what you will see Katon doing + + + align:start position:0% +one week what you will see Katon doing +in those films is learning how to link + + align:start position:0% +in those films is learning how to link + + + align:start position:0% +in those films is learning how to link +jokes together in some sort of a + + align:start position:0% +jokes together in some sort of a + + + align:start position:0% +jokes together in some sort of a +coherent way but the films and and there + + align:start position:0% +coherent way but the films and and there + + + align:start position:0% +coherent way but the films and and there +are wonderful coherent sequences in + + align:start position:0% +are wonderful coherent sequences in + + + align:start position:0% +are wonderful coherent sequences in +these films but still one doesn't feel + + align:start position:0% +these films but still one doesn't feel + + + align:start position:0% +these films but still one doesn't feel +that there's a real character in them + + align:start position:0% +that there's a real character in them + + + align:start position:0% +that there's a real character in them +that there's a sustained coherent uh + + align:start position:0% +that there's a sustained coherent uh + + + align:start position:0% +that there's a sustained coherent uh +fictional universe being dramat + + align:start position:0% +fictional universe being dramat + + + align:start position:0% +fictional universe being dramat +Maybe in Cops one does feel this. + + align:start position:0% +Maybe in Cops one does feel this. + + + align:start position:0% +Maybe in Cops one does feel this. +There's much more sort of textural + + align:start position:0% +There's much more sort of textural + + + align:start position:0% +There's much more sort of textural +coherence in Cops. But what we can see + + align:start position:0% +coherence in Cops. But what we can see + + + align:start position:0% +coherence in Cops. But what we can see +Katon doing is beginning to move from + + align:start position:0% +Katon doing is beginning to move from + + + align:start position:0% +Katon doing is beginning to move from +the idea of a single joke to a sequence + + align:start position:0% +the idea of a single joke to a sequence + + + align:start position:0% +the idea of a single joke to a sequence +of jokes. And then by the time we get to + + align:start position:0% +of jokes. And then by the time we get to + + + align:start position:0% +of jokes. And then by the time we get to +the general moving from a sequence of + + align:start position:0% +the general moving from a sequence of + + + align:start position:0% +the general moving from a sequence of +from a single joke to a sequence of + + align:start position:0% +from a single joke to a sequence of + + + align:start position:0% +from a single joke to a sequence of +jokes to a sustained narrative which + + align:start position:0% +jokes to a sustained narrative which + + + align:start position:0% +jokes to a sustained narrative which +incorporates within it various kinds of + + align:start position:0% +incorporates within it various kinds of + + + align:start position:0% +incorporates within it various kinds of +comical jokes and also sequence jokes + + align:start position:0% +comical jokes and also sequence jokes + + + align:start position:0% +comical jokes and also sequence jokes +because Katon's best jokes are not + + align:start position:0% +because Katon's best jokes are not + + + align:start position:0% +because Katon's best jokes are not +single jokes at all not oneliners but + + align:start position:0% +single jokes at all not oneliners but + + + align:start position:0% +single jokes at all not oneliners but +the the joke will be told again and + + align:start position:0% +the the joke will be told again and + + + align:start position:0% +the the joke will be told again and +again or what or really what will happen + + align:start position:0% +again or what or really what will happen + + + align:start position:0% +again or what or really what will happen +is he will do something and you'll think + + align:start position:0% +is he will do something and you'll think + + + align:start position:0% +is he will do something and you'll think +how could and then he'll the next step + + align:start position:0% +how could and then he'll the next step + + + align:start position:0% +how could and then he'll the next step +will top what he's done before and the + + align:start position:0% +will top what he's done before and the + + + align:start position:0% +will top what he's done before and the +next step will top you think that he got + + align:start position:0% +next step will top you think that he got + + + align:start position:0% +next step will top you think that he got +to a point where it would be impossible + + align:start position:0% +to a point where it would be impossible + + + align:start position:0% +to a point where it would be impossible +possible to add another comic + + align:start position:0% +possible to add another comic + + + align:start position:0% +possible to add another comic +complication to what he's done when he + + align:start position:0% +complication to what he's done when he + + + align:start position:0% +complication to what he's done when he +of course does it. Uh and this becomes + + align:start position:0% +of course does it. Uh and this becomes + + + align:start position:0% +of course does it. Uh and this becomes +one of the deep principles of chap of of + + align:start position:0% +one of the deep principles of chap of of + + + align:start position:0% +one of the deep principles of chap of of +Katon's comedy. There are numerous + + align:start position:0% +Katon's comedy. There are numerous + + + align:start position:0% +Katon's comedy. There are numerous +examples of it in both the two shorts + + align:start position:0% +examples of it in both the two shorts + + + align:start position:0% +examples of it in both the two shorts +and in this in the longer film that I + + align:start position:0% +and in this in the longer film that I + + + align:start position:0% +and in this in the longer film that I +that uh the the general but let me + + align:start position:0% +that uh the the general but let me + + + align:start position:0% +that uh the the general but let me +mention an example from the general. + + align:start position:0% +mention an example from the general. + + + align:start position:0% +mention an example from the general. +Very early in the general there's a + + align:start position:0% +Very early in the general there's a + + + align:start position:0% +Very early in the general there's a +sequence it's probably the + + align:start position:0% +sequence it's probably the + + + align:start position:0% +sequence it's probably the +quintessential Katon sequence and I + + align:start position:0% +quintessential Katon sequence and I + + + align:start position:0% +quintessential Katon sequence and I +won't go into such detail as to spoil + + align:start position:0% +won't go into such detail as to spoil + + + align:start position:0% +won't go into such detail as to spoil +the film for you. Uh but let me just say + + align:start position:0% +the film for you. Uh but let me just say + + + align:start position:0% +the film for you. Uh but let me just say +it involves a cannon and it involves + + align:start position:0% +it involves a cannon and it involves + + + align:start position:0% +it involves a cannon and it involves +Katon uh uh who's chasing after Katon + + align:start position:0% +Katon uh uh who's chasing after Katon + + + align:start position:0% +Katon uh uh who's chasing after Katon +plays a uh the engineer of a of of a + + align:start position:0% +plays a uh the engineer of a of of a + + + align:start position:0% +plays a uh the engineer of a of of a +locomotive, a locomotive engineer. The + + align:start position:0% +locomotive, a locomotive engineer. The + + + align:start position:0% +locomotive, a locomotive engineer. The +general of the title is not a a mar a + + align:start position:0% +general of the title is not a a mar a + + + align:start position:0% +general of the title is not a a mar a +military general. It's a locomotive. The + + align:start position:0% +military general. It's a locomotive. The + + + align:start position:0% +military general. It's a locomotive. The +locomotive is called the general. And + + align:start position:0% +locomotive is called the general. And + + + align:start position:0% +locomotive is called the general. And +the and the film recounts a historically + + align:start position:0% +the and the film recounts a historically + + + align:start position:0% +the and the film recounts a historically +true story of a of a time when the Union + + align:start position:0% +true story of a of a time when the Union + + + align:start position:0% +true story of a of a time when the Union +Army um came in uh that with uh the + + align:start position:0% +Army um came in uh that with uh the + + + align:start position:0% +Army um came in uh that with uh the +Confederate army uh the Union Army came + + align:start position:0% +Confederate army uh the Union Army came + + + align:start position:0% +Confederate army uh the Union Army came +into Confederate territory and stole a + + align:start position:0% +into Confederate territory and stole a + + + align:start position:0% +into Confederate territory and stole a +locomotive belonging to the Confederacy. + + align:start position:0% +locomotive belonging to the Confederacy. + + + align:start position:0% +locomotive belonging to the Confederacy. +And this and and he was a and Keaton in + + align:start position:0% +And this and and he was a and Keaton in + + + align:start position:0% +And this and and he was a and Keaton in +a comic vein retells retells this story. + + align:start position:0% +a comic vein retells retells this story. + + + align:start position:0% +a comic vein retells retells this story. +When you watch this cannon sequence, + + align:start position:0% +When you watch this cannon sequence, + + + align:start position:0% +When you watch this cannon sequence, +you'll see exactly what I mean. You'll + + align:start position:0% +you'll see exactly what I mean. You'll + + + align:start position:0% +you'll see exactly what I mean. You'll +and this sequence is at the heart of + + align:start position:0% +and this sequence is at the heart of + + + align:start position:0% +and this sequence is at the heart of +James AG's essay on the silent film + + align:start position:0% +James AG's essay on the silent film + + + align:start position:0% +James AG's essay on the silent film +comedy. And when you read that essay, + + align:start position:0% +comedy. And when you read that essay, + + + align:start position:0% +comedy. And when you read that essay, +you'll see even more clearly what I mean + + align:start position:0% +you'll see even more clearly what I mean + + + align:start position:0% +you'll see even more clearly what I mean +by a trajectory joke or a sequence joke + + align:start position:0% +by a trajectory joke or a sequence joke + + + align:start position:0% +by a trajectory joke or a sequence joke +which builds and builds and builds and + + align:start position:0% +which builds and builds and builds and + + + align:start position:0% +which builds and builds and builds and +keeps topping itself. Well, this cannon + + align:start position:0% +keeps topping itself. Well, this cannon + + + align:start position:0% +keeps topping itself. Well, this cannon +sequence is a perfect example of that. + + align:start position:0% +sequence is a perfect example of that. + + + align:start position:0% +sequence is a perfect example of that. +And it's a perfect example of it not + + align:start position:0% +And it's a perfect example of it not + + + align:start position:0% +And it's a perfect example of it not +only because we see the joke getting + + align:start position:0% +only because we see the joke getting + + + align:start position:0% +only because we see the joke getting +more complicated as it goes on, but as + + align:start position:0% +more complicated as it goes on, but as + + + align:start position:0% +more complicated as it goes on, but as +the joke becomes more complicated, + + align:start position:0% +the joke becomes more complicated, + + + align:start position:0% +the joke becomes more complicated, +something else happens. The joke becomes + + align:start position:0% +something else happens. The joke becomes + + + align:start position:0% +something else happens. The joke becomes +more than a joke. It becomes a kind of + + align:start position:0% +more than a joke. It becomes a kind of + + + align:start position:0% +more than a joke. It becomes a kind of +comment on experience. It becomes a kind + + align:start position:0% +comment on experience. It becomes a kind + + + align:start position:0% +comment on experience. It becomes a kind +of comment on on on on on + + align:start position:0% +of comment on on on on on + + + align:start position:0% +of comment on on on on on +what life is like. That is to say, we + + align:start position:0% +what life is like. That is to say, we + + + align:start position:0% +what life is like. That is to say, we +move from something that simply makes us + + align:start position:0% +move from something that simply makes us + + + align:start position:0% +move from something that simply makes us +smile to something that makes us think + + align:start position:0% +smile to something that makes us think + + + align:start position:0% +smile to something that makes us think +about the world, that comments on the + + align:start position:0% +about the world, that comments on the + + + align:start position:0% +about the world, that comments on the +world, that imagines the world in a + + align:start position:0% +world, that imagines the world in a + + + align:start position:0% +world, that imagines the world in a +coherent way. I'll try to be more + + align:start position:0% +coherent way. I'll try to be more + + + align:start position:0% +coherent way. I'll try to be more +explicit about this in a in a in in a + + align:start position:0% +explicit about this in a in a in in a + + + align:start position:0% +explicit about this in a in a in in a +moment. So in Katon's career, we see him + + align:start position:0% +moment. So in Katon's career, we see him + + + align:start position:0% +moment. So in Katon's career, we see him +doing astonishing things as an acrobat + + align:start position:0% +doing astonishing things as an acrobat + + + align:start position:0% +doing astonishing things as an acrobat +and we would admire him just for his + + align:start position:0% +and we would admire him just for his + + + align:start position:0% +and we would admire him just for his +acrobatic performances in these films. + + align:start position:0% +acrobatic performances in these films. + + + align:start position:0% +acrobatic performances in these films. +Watch in this film in the in the + + align:start position:0% +Watch in this film in the in the + + + align:start position:0% +Watch in this film in the in the +general, for example, the way in which + + align:start position:0% +general, for example, the way in which + + + align:start position:0% +general, for example, the way in which +when he's piloting his locomotive, + + align:start position:0% +when he's piloting his locomotive, + + + align:start position:0% +when he's piloting his locomotive, +chasing the people who have stolen his + + align:start position:0% +chasing the people who have stolen his + + + align:start position:0% +chasing the people who have stolen his +original locomotive, how he's the only + + align:start position:0% +original locomotive, how he's the only + + + align:start position:0% +original locomotive, how he's the only +one on the train and he crawls all over + + align:start position:0% +one on the train and he crawls all over + + + align:start position:0% +one on the train and he crawls all over +the train. He + + align:start position:0% +the train. He + + + align:start position:0% +the train. He +almost every while the train is running, + + align:start position:0% +almost every while the train is running, + + + align:start position:0% +almost every while the train is running, +he'll crawl up to the front of it. He'll + + align:start position:0% +he'll crawl up to the front of it. He'll + + + align:start position:0% +he'll crawl up to the front of it. He'll +run to the back of it to put more fuel + + align:start position:0% +run to the back of it to put more fuel + + + align:start position:0% +run to the back of it to put more fuel +in. you what you can what you can see is + + align:start position:0% +in. you what you can what you can see is + + + align:start position:0% +in. you what you can what you can see is +and and also you can see this stuff + + align:start position:0% +and and also you can see this stuff + + + align:start position:0% +and and also you can see this stuff +happening in really happening. It's not + + align:start position:0% +happening in really happening. It's not + + + align:start position:0% +happening in really happening. It's not +faked in any way because there's a there + + align:start position:0% +faked in any way because there's a there + + + align:start position:0% +faked in any way because there's a there +is a a camera following the train as + + align:start position:0% +is a a camera following the train as + + + align:start position:0% +is a a camera following the train as +it's moving. You can see it's really + + align:start position:0% +it's moving. You can see it's really + + + align:start position:0% +it's moving. You can see it's really +moving because you can you can see it + + align:start position:0% +moving because you can you can see it + + + align:start position:0% +moving because you can you can see it +you can see it moving on the track and + + align:start position:0% +you can see it moving on the track and + + + align:start position:0% +you can see it moving on the track and +you can see the world behind it and you + + align:start position:0% +you can see the world behind it and you + + + align:start position:0% +you can see the world behind it and you +can you can tell that Katon is not + + align:start position:0% +can you can tell that Katon is not + + + align:start position:0% +can you can tell that Katon is not +faking these effects. Well, this cannon + + align:start position:0% +faking these effects. Well, this cannon + + + align:start position:0% +faking these effects. Well, this cannon +sequence is a is a is a sublimely rich + + align:start position:0% +sequence is a is a is a sublimely rich + + + align:start position:0% +sequence is a is a is a sublimely rich +example of this complex process I've + + align:start position:0% +example of this complex process I've + + + align:start position:0% +example of this complex process I've +been describing and it it has to do in + + align:start position:0% +been describing and it it has to do in + + + align:start position:0% +been describing and it it has to do in +part with what I call the multiplicity + + align:start position:0% +part with what I call the multiplicity + + + align:start position:0% +part with what I call the multiplicity +principle which I will define in a + + align:start position:0% +principle which I will define in a + + + align:start position:0% +principle which I will define in a +moment. So we see Katon as an actor as + + align:start position:0% +moment. So we see Katon as an actor as + + + align:start position:0% +moment. So we see Katon as an actor as +an acrobat as an acrobat actor as an + + align:start position:0% +an acrobat as an acrobat actor as an + + + align:start position:0% +an acrobat as an acrobat actor as an +incredibly in as a man much more than + + align:start position:0% +incredibly in as a man much more than + + + align:start position:0% +incredibly in as a man much more than +cha chaplain interested in the + + align:start position:0% +cha chaplain interested in the + + + align:start position:0% +cha chaplain interested in the +technology of motion pictures and of + + align:start position:0% +technology of motion pictures and of + + + align:start position:0% +technology of motion pictures and of +cinema. And you'll see a couple of + + align:start position:0% +cinema. And you'll see a couple of + + + align:start position:0% +cinema. And you'll see a couple of +examples in the films you're going to + + align:start position:0% +examples in the films you're going to + + + align:start position:0% +examples in the films you're going to +look at tonight in which we see Katon + + align:start position:0% +look at tonight in which we see Katon + + + align:start position:0% +look at tonight in which we see Katon +exploring uh in a somewhat systematic + + align:start position:0% +exploring uh in a somewhat systematic + + + align:start position:0% +exploring uh in a somewhat systematic +way the nature of the illusion of the + + align:start position:0% +way the nature of the illusion of the + + + align:start position:0% +way the nature of the illusion of the +motion pictures. There's one remarkable + + align:start position:0% +motion pictures. There's one remarkable + + + align:start position:0% +motion pictures. There's one remarkable +moment, comical moment in one week in + + align:start position:0% +moment, comical moment in one week in + + + align:start position:0% +moment, comical moment in one week in +which uh the heroine gets into a bathtub + + align:start position:0% +which uh the heroine gets into a bathtub + + + align:start position:0% +which uh the heroine gets into a bathtub +and it looks like you and she's sitting + + align:start position:0% +and it looks like you and she's sitting + + + align:start position:0% +and it looks like you and she's sitting +in the bathtub. She's starting to get up + + align:start position:0% +in the bathtub. She's starting to get up + + + align:start position:0% +in the bathtub. She's starting to get up +and it looks like you're actually about + + align:start position:0% +and it looks like you're actually about + + + align:start position:0% +and it looks like you're actually about +to see some unmentionable parts of her + + align:start position:0% +to see some unmentionable parts of her + + + align:start position:0% +to see some unmentionable parts of her +body and just as that's about to happen + + align:start position:0% +body and just as that's about to happen + + + align:start position:0% +body and just as that's about to happen +a hand comes in front of the camera and + + align:start position:0% +a hand comes in front of the camera and + + + align:start position:0% +a hand comes in front of the camera and +blocks you. And it's actually a very + + align:start position:0% +blocks you. And it's actually a very + + + align:start position:0% +blocks you. And it's actually a very +disturbing moment in a way because it + + align:start position:0% +disturbing moment in a way because it + + + align:start position:0% +disturbing moment in a way because it +interrupts the narrative flow. It's it's + + align:start position:0% +interrupts the narrative flow. It's it's + + + align:start position:0% +interrupts the narrative flow. It's it's +a it's an intervention from the outside + + align:start position:0% +a it's an intervention from the outside + + + align:start position:0% +a it's an intervention from the outside +whose hand it is. It's not a character + + align:start position:0% +whose hand it is. It's not a character + + + align:start position:0% +whose hand it is. It's not a character +in the film. It's the director or + + align:start position:0% +in the film. It's the director or + + + align:start position:0% +in the film. It's the director or +something, right? It's very bold moment + + align:start position:0% +something, right? It's very bold moment + + + align:start position:0% +something, right? It's very bold moment +because what it does is it reminds you + + align:start position:0% +because what it does is it reminds you + + + align:start position:0% +because what it does is it reminds you +of the film as an artifact. It reminds + + align:start position:0% +of the film as an artifact. It reminds + + + align:start position:0% +of the film as an artifact. It reminds +you that the film is uh an + + align:start position:0% +you that the film is uh an + + + align:start position:0% +you that the film is uh an +artiflexiveness + + align:start position:0% +artiflexiveness + + + align:start position:0% +artiflexiveness +or self-consciousness that you would + + align:start position:0% +or self-consciousness that you would + + + align:start position:0% +or self-consciousness that you would +never see in a Chaplain film, but shows + + align:start position:0% +never see in a Chaplain film, but shows + + + align:start position:0% +never see in a Chaplain film, but shows +Katon's astonishing interest in the + + align:start position:0% +Katon's astonishing interest in the + + + align:start position:0% +Katon's astonishing interest in the +technology of motion pictures. Uh, I had + + align:start position:0% +technology of motion pictures. Uh, I had + + + align:start position:0% +technology of motion pictures. Uh, I had +many examples that Greg and I had ready, + + align:start position:0% +many examples that Greg and I had ready, + + + align:start position:0% +many examples that Greg and I had ready, +but I don't have time to show them to + + align:start position:0% +but I don't have time to show them to + + + align:start position:0% +but I don't have time to show them to +you. Maybe you can put up while I'm + + align:start position:0% +you. Maybe you can put up while I'm + + + align:start position:0% +you. Maybe you can put up while I'm +talking. The the Playhouse. One of his + + align:start position:0% +talking. The the Playhouse. One of his + + + align:start position:0% +talking. The the Playhouse. One of his +most famous examples of this is a film + + align:start position:0% +most famous examples of this is a film + + + align:start position:0% +most famous examples of this is a film +called The Playhouse in which he ends up + + align:start position:0% +called The Playhouse in which he ends up + + + align:start position:0% +called The Playhouse in which he ends up +playing every role in the movie. And the + + align:start position:0% +playing every role in the movie. And the + + + align:start position:0% +playing every role in the movie. And the +way he did this was incred was + + align:start position:0% +way he did this was incred was + + + align:start position:0% +way he did this was incred was +incredibly interesting. He would shoot + + align:start position:0% +incredibly interesting. He would shoot + + + align:start position:0% +incredibly interesting. He would shoot +the film. Uh, and then he he would shoot + + align:start position:0% +the film. Uh, and then he he would shoot + + + align:start position:0% +the film. Uh, and then he he would shoot +the film, but he would but he put a he + + align:start position:0% +the film, but he would but he put a he + + + align:start position:0% +the film, but he would but he put a he +put masking tape over the lens of the + + align:start position:0% +put masking tape over the lens of the + + + align:start position:0% +put masking tape over the lens of the +camera and only one little tiny part of + + align:start position:0% +camera and only one little tiny part of + + + align:start position:0% +camera and only one little tiny part of +the of the lens of the camera was was + + align:start position:0% +the of the lens of the camera was was + + + align:start position:0% +the of the lens of the camera was was +would expose the film and he would he + + align:start position:0% +would expose the film and he would he + + + align:start position:0% +would expose the film and he would he +would shoot that. Then he would rewind + + align:start position:0% +would shoot that. Then he would rewind + + + align:start position:0% +would shoot that. Then he would rewind +the film and then if he were over in + + align:start position:0% +the film and then if he were over in + + + align:start position:0% +the film and then if he were over in +this corner for that shot, then he'd + + align:start position:0% +this corner for that shot, then he'd + + + align:start position:0% +this corner for that shot, then he'd +move over and sit in the other corner. + + align:start position:0% +move over and sit in the other corner. + + + align:start position:0% +move over and sit in the other corner. +He'd put a new kind of tape on the + + align:start position:0% +He'd put a new kind of tape on the + + + align:start position:0% +He'd put a new kind of tape on the +camera, film it again. And the film + + align:start position:0% +camera, film it again. And the film + + + align:start position:0% +camera, film it again. And the film +you're going to see will show this. And + + align:start position:0% +you're going to see will show this. And + + + align:start position:0% +you're going to see will show this. And +you can see they're all buster, right? + + align:start position:0% +you can see they're all buster, right? + + + align:start position:0% +you can see they're all buster, right? +It's a it's an it's a it's again what it + + align:start position:0% +It's a it's an it's a it's again what it + + + align:start position:0% +It's a it's an it's a it's again what it +shows is he's a technician. He's + + align:start position:0% +shows is he's a technician. He's + + + align:start position:0% +shows is he's a technician. He's +interested in the technology of motion p + + align:start position:0% +interested in the technology of motion p + + + align:start position:0% +interested in the technology of motion p +of of of the of the uh motion picture + + align:start position:0% +of of of the of the uh motion picture + + + align:start position:0% +of of of the of the uh motion picture +camera and what kinds of manipulations + + align:start position:0% +camera and what kinds of manipulations + + + align:start position:0% +camera and what kinds of manipulations +are possible because he's the conductor, + + align:start position:0% +are possible because he's the conductor, + + + align:start position:0% +are possible because he's the conductor, +right? He's you'll as it turns out he's + + align:start position:0% +right? He's you'll as it turns out he's + + + align:start position:0% +right? He's you'll as it turns out he's +going to also end up being the o the the + + align:start position:0% +going to also end up being the o the the + + + align:start position:0% +going to also end up being the o the the +only person in the audience. Well, um, + + align:start position:0% +only person in the audience. Well, um, + + + align:start position:0% +only person in the audience. Well, um, +and then finally, what what what I've + + align:start position:0% +and then finally, what what what I've + + + align:start position:0% +and then finally, what what what I've +already implied is that Keaton's jokes + + align:start position:0% +already implied is that Keaton's jokes + + + align:start position:0% +already implied is that Keaton's jokes +and his technical interests also end up + + align:start position:0% +and his technical interests also end up + + + align:start position:0% +and his technical interests also end up +making him a metaphysician, a + + align:start position:0% +making him a metaphysician, a + + + align:start position:0% +making him a metaphysician, a +philosopher, an artist. Now, Katon + + align:start position:0% +philosopher, an artist. Now, Katon + + + align:start position:0% +philosopher, an artist. Now, Katon +himself could never articulate his own + + align:start position:0% +himself could never articulate his own + + + align:start position:0% +himself could never articulate his own +ambitions in this way. If you said, "Mr. + + align:start position:0% +ambitions in this way. If you said, "Mr. + + + align:start position:0% +ambitions in this way. If you said, "Mr. +Keaton, your vision of the absurd + + align:start position:0% +Keaton, your vision of the absurd + + + align:start position:0% +Keaton, your vision of the absurd +universe is more complex and rich than + + align:start position:0% +universe is more complex and rich than + + + align:start position:0% +universe is more complex and rich than +Jean Paul Sarts," as in fact it is, + + align:start position:0% +Jean Paul Sarts," as in fact it is, + + + align:start position:0% +Jean Paul Sarts," as in fact it is, +incidentally, he would laugh. He + + align:start position:0% +incidentally, he would laugh. He + + + align:start position:0% +incidentally, he would laugh. He +wouldn't even understand what you were + + align:start position:0% +wouldn't even understand what you were + + + align:start position:0% +wouldn't even understand what you were +talking about. Not only because he'd + + align:start position:0% +talking about. Not only because he'd + + + align:start position:0% +talking about. Not only because he'd +never read Sart since he died before he + + align:start position:0% +never read Sart since he died before he + + + align:start position:0% +never read Sart since he died before he +well sorry he was alive when Sart was + + align:start position:0% +well sorry he was alive when Sart was + + + align:start position:0% +well sorry he was alive when Sart was +alive actually but but he undoubtedly he + + align:start position:0% +alive actually but but he undoubtedly he + + + align:start position:0% +alive actually but but he undoubtedly he +did not read but the universe that he + + align:start position:0% +did not read but the universe that he + + + align:start position:0% +did not read but the universe that he +projects uh has has a kind of content or + + align:start position:0% +projects uh has has a kind of content or + + + align:start position:0% +projects uh has has a kind of content or +a meaning that's a function of how + + align:start position:0% +a meaning that's a function of how + + + align:start position:0% +a meaning that's a function of how +intelligent he is about exploiting his + + align:start position:0% +intelligent he is about exploiting his + + + align:start position:0% +intelligent he is about exploiting his +medium and telling his stories as if his + + align:start position:0% +medium and telling his stories as if his + + + align:start position:0% +medium and telling his stories as if his +jokes express a vision of life a sense + + align:start position:0% +jokes express a vision of life a sense + + + align:start position:0% +jokes express a vision of life a sense +of experience. Now this so you um and of + + align:start position:0% +of experience. Now this so you um and of + + + align:start position:0% +of experience. Now this so you um and of +course this is what you're looking at is + + align:start position:0% +course this is what you're looking at is + + + align:start position:0% +course this is what you're looking at is +sort of minor keaton here but it but it + + align:start position:0% +sort of minor keaton here but it but it + + + align:start position:0% +sort of minor keaton here but it but it +shows his it shows his technical his + + align:start position:0% +shows his it shows his technical his + + + align:start position:0% +shows his it shows his technical his +technical interests well so what I mean + + align:start position:0% +technical interests well so what I mean + + + align:start position:0% +technical interests well so what I mean +so let me explain what I mean basically + + align:start position:0% +so let me explain what I mean basically + + + align:start position:0% +so let me explain what I mean basically +by the multiplicity principle this + + align:start position:0% +by the multiplicity principle this + + + align:start position:0% +by the multiplicity principle this +process of accretion and complexity I've + + align:start position:0% +process of accretion and complexity I've + + + align:start position:0% +process of accretion and complexity I've +described at a certain point you get to + + align:start position:0% +described at a certain point you get to + + + align:start position:0% +described at a certain point you get to +a point where what what began as a gag + + align:start position:0% +a point where what what began as a gag + + + align:start position:0% +a point where what what began as a gag +or as a mere entertainment takes on a + + align:start position:0% +or as a mere entertainment takes on a + + + align:start position:0% +or as a mere entertainment takes on a +density or a texture that makes you + + align:start position:0% +density or a texture that makes you + + + align:start position:0% +density or a texture that makes you +think wait a second the vision of + + align:start position:0% +think wait a second the vision of + + + align:start position:0% +think wait a second the vision of +experience that's projected in This text + + align:start position:0% +experience that's projected in This text + + + align:start position:0% +experience that's projected in This text +is intrinsically interesting. That is to + + align:start position:0% +is intrinsically interesting. That is to + + + align:start position:0% +is intrinsically interesting. That is to +say, there's an understanding of life + + align:start position:0% +say, there's an understanding of life + + + align:start position:0% +say, there's an understanding of life +that's embedded in the story. When you + + align:start position:0% +that's embedded in the story. When you + + + align:start position:0% +that's embedded in the story. When you +reach the point where the text itself + + align:start position:0% +reach the point where the text itself + + + align:start position:0% +reach the point where the text itself +embodies some sort of understanding of + + align:start position:0% +embodies some sort of understanding of + + + align:start position:0% +embodies some sort of understanding of +life and it's coherent, an understanding + + align:start position:0% +life and it's coherent, an understanding + + + align:start position:0% +life and it's coherent, an understanding +of life that's coherently presented, + + align:start position:0% +of life that's coherently presented, + + + align:start position:0% +of life that's coherently presented, +powerfully presented, what you're what + + align:start position:0% +powerfully presented, what you're what + + + align:start position:0% +powerfully presented, what you're what +you're looking at is what I call art. + + align:start position:0% +you're looking at is what I call art. + + + align:start position:0% +you're looking at is what I call art. +There's you might just call it more + + align:start position:0% +There's you might just call it more + + + align:start position:0% +There's you might just call it more +intelligent entertainment, but this is a + + align:start position:0% +intelligent entertainment, but this is a + + + align:start position:0% +intelligent entertainment, but this is a +way of distinguishing between + + align:start position:0% +way of distinguishing between + + + align:start position:0% +way of distinguishing between +entertainment and art. In other words, + + align:start position:0% +entertainment and art. In other words, + + + align:start position:0% +entertainment and art. In other words, +there's a certain point at which + + align:start position:0% +there's a certain point at which + + + align:start position:0% +there's a certain point at which +entertainment becomes so complicated + + align:start position:0% +entertainment becomes so complicated + + + align:start position:0% +entertainment becomes so complicated +that it's more than mere entertainment. + + align:start position:0% +that it's more than mere entertainment. + + + align:start position:0% +that it's more than mere entertainment. +When does that occur? Well, one way to + + align:start position:0% +When does that occur? Well, one way to + + + align:start position:0% +When does that occur? Well, one way to +tell when it occurs is to watch for what + + align:start position:0% +tell when it occurs is to watch for what + + + align:start position:0% +tell when it occurs is to watch for what +I call the multiplicity principle. When + + align:start position:0% +I call the multiplicity principle. When + + + align:start position:0% +I call the multiplicity principle. When +events in the film play more than one + + align:start position:0% +events in the film play more than one + + + align:start position:0% +events in the film play more than one +function, do more than one job. When + + align:start position:0% +function, do more than one job. When + + + align:start position:0% +function, do more than one job. When +they forward the story but also declare + + align:start position:0% +they forward the story but also declare + + + align:start position:0% +they forward the story but also declare +for character. when they express when + + align:start position:0% +for character. when they express when + + + align:start position:0% +for character. when they express when +they make you laugh but also express a + + align:start position:0% +they make you laugh but also express a + + + align:start position:0% +they make you laugh but also express a +vision of life and at the same time ex + + align:start position:0% +vision of life and at the same time ex + + + align:start position:0% +vision of life and at the same time ex +uh are consistent with the character + + align:start position:0% +uh are consistent with the character + + + align:start position:0% +uh are consistent with the character +psychological nature that multiplicity + + align:start position:0% +psychological nature that multiplicity + + + align:start position:0% +psychological nature that multiplicity +that density that texture is what we + + align:start position:0% +that density that texture is what we + + + align:start position:0% +that density that texture is what we +associate with works of art right uh a + + align:start position:0% +associate with works of art right uh a + + + align:start position:0% +associate with works of art right uh a +bad example would be you're all familiar + + align:start position:0% +bad example would be you're all familiar + + + align:start position:0% +bad example would be you're all familiar +I hope with the kind of bad soap opera + + align:start position:0% +I hope with the kind of bad soap opera + + + align:start position:0% +I hope with the kind of bad soap opera +line in which a character comes in and + + align:start position:0% +line in which a character comes in and + + + align:start position:0% +line in which a character comes in and +says something like this oh hello John + + align:start position:0% +says something like this oh hello John + + + align:start position:0% +says something like this oh hello John +my longlost brother who just got out of + + align:start position:0% +my longlost brother who just got out of + + + align:start position:0% +my longlost brother who just got out of +the insane asylum after 15 years of + + align:start position:0% +the insane asylum after 15 years of + + + align:start position:0% +the insane asylum after 15 years of +unfair misery All right. What's wrong + + align:start position:0% +unfair misery All right. What's wrong + + + align:start position:0% +unfair misery All right. What's wrong +with that line? Why is that a stupid + + align:start position:0% +with that line? Why is that a stupid + + + align:start position:0% +with that line? Why is that a stupid +line? Although we hear them all the + + align:start position:0% +line? Although we hear them all the + + + align:start position:0% +line? Although we hear them all the +time. What What's wrong with it? + + align:start position:0% +time. What What's wrong with it? + + + align:start position:0% +time. What What's wrong with it? +Excessive and awkward exposition. It's + + align:start position:0% +Excessive and awkward exposition. It's + + + align:start position:0% +Excessive and awkward exposition. It's +it's very awkward exposition. But why is + + align:start position:0% +it's very awkward exposition. But why is + + + align:start position:0% +it's very awkward exposition. But why is +it so awkward? What makes it so awkward? + + align:start position:0% +it so awkward? What makes it so awkward? + + + align:start position:0% +it so awkward? What makes it so awkward? +It's it's its intention is clear. It + + align:start position:0% +It's it's its intention is clear. It + + + align:start position:0% +It's it's its intention is clear. It +wants to present information to the + + align:start position:0% +wants to present information to the + + + align:start position:0% +wants to present information to the +audience. But in order to do that, what + + align:start position:0% +audience. But in order to do that, what + + + align:start position:0% +audience. But in order to do that, what +what is it violated? Um it's ceases to + + align:start position:0% +what is it violated? Um it's ceases to + + + align:start position:0% +what is it violated? Um it's ceases to +be something that follows the nature of + + align:start position:0% +be something that follows the nature of + + + align:start position:0% +be something that follows the nature of +the character. It ceases to be something + + align:start position:0% +the character. It ceases to be something + + + align:start position:0% +the character. It ceases to be something +that is that honors the character's + + align:start position:0% +that is that honors the character's + + + align:start position:0% +that is that honors the character's +nature. Exactly right. That's a very + + align:start position:0% +nature. Exactly right. That's a very + + + align:start position:0% +nature. Exactly right. That's a very +good answer. What's your name? Michael. + + align:start position:0% +good answer. What's your name? Michael. + + + align:start position:0% +good answer. What's your name? Michael. +Michael. Thank Michael. That's very + + align:start position:0% +Michael. Thank Michael. That's very + + + align:start position:0% +Michael. Thank Michael. That's very +good. And what what happened? Okay. I + + align:start position:0% +good. And what what happened? Okay. I + + + align:start position:0% +good. And what what happened? Okay. I +want to give information to the + + align:start position:0% +want to give information to the + + + align:start position:0% +want to give information to the +audience. In order to do that, I'll + + align:start position:0% +audience. In order to do that, I'll + + + align:start position:0% +audience. In order to do that, I'll +compromise the character's basic nature + + align:start position:0% +compromise the character's basic nature + + + align:start position:0% +compromise the character's basic nature +because no brother, no sister talking to + + align:start position:0% +because no brother, no sister talking to + + + align:start position:0% +because no brother, no sister talking to +a brother would recount the brother's + + align:start position:0% +a brother would recount the brother's + + + align:start position:0% +a brother would recount the brother's +history to the brother, right? That just + + align:start position:0% +history to the brother, right? That just + + + align:start position:0% +history to the brother, right? That just +wouldn't happen. Right? So, in order to + + align:start position:0% +wouldn't happen. Right? So, in order to + + + align:start position:0% +wouldn't happen. Right? So, in order to +accomplish one task, the text has + + align:start position:0% +accomplish one task, the text has + + + align:start position:0% +accomplish one task, the text has +compromised itself on another task. But + + align:start position:0% +compromised itself on another task. But + + + align:start position:0% +compromised itself on another task. But +imagine a story in which this + + align:start position:0% +imagine a story in which this + + + align:start position:0% +imagine a story in which this +information emerges in in dramatic ways. + + align:start position:0% +information emerges in in dramatic ways. + + + align:start position:0% +information emerges in in dramatic ways. +two characters are talking and Mary says + + align:start position:0% +two characters are talking and Mary says + + + align:start position:0% +two characters are talking and Mary says +to Joan, "Oh, Joan, my brother's coming + + align:start position:0% +to Joan, "Oh, Joan, my brother's coming + + + align:start position:0% +to Joan, "Oh, Joan, my brother's coming +back from the asylum." And she says, + + align:start position:0% +back from the asylum." And she says, + + + align:start position:0% +back from the asylum." And she says, +"Really? I didn't even know he was in + + align:start position:0% +"Really? I didn't even know he was in + + + align:start position:0% +"Really? I didn't even know he was in +the asylum." And Mary pulls back and + + align:start position:0% +the asylum." And Mary pulls back and + + + align:start position:0% +the asylum." And Mary pulls back and +says, "I don't know if I should tell + + align:start position:0% +says, "I don't know if I should tell + + + align:start position:0% +says, "I don't know if I should tell +you." Right. Okay. So, we have a we have + + align:start position:0% +you." Right. Okay. So, we have a we have + + + align:start position:0% +you." Right. Okay. So, we have a we have +a dramatic scene in which what in which + + align:start position:0% +a dramatic scene in which what in which + + + align:start position:0% +a dramatic scene in which what in which +the information that the audience is + + align:start position:0% +the information that the audience is + + + align:start position:0% +the information that the audience is +supposed to have is presented in a way + + align:start position:0% +supposed to have is presented in a way + + + align:start position:0% +supposed to have is presented in a way +that maybe tells us something about + + align:start position:0% +that maybe tells us something about + + + align:start position:0% +that maybe tells us something about +Mary's nature and maybe tells us + + align:start position:0% +Mary's nature and maybe tells us + + + align:start position:0% +Mary's nature and maybe tells us +something about Joan's nature. That is + + align:start position:0% +something about Joan's nature. That is + + + align:start position:0% +something about Joan's nature. That is +multiplicity, right? More that's what I + + align:start position:0% +multiplicity, right? More that's what I + + + align:start position:0% +multiplicity, right? More that's what I +mean by the multiplicity principle. You + + align:start position:0% +mean by the multiplicity principle. You + + + align:start position:0% +mean by the multiplicity principle. You +will see many many instances of what of + + align:start position:0% +will see many many instances of what of + + + align:start position:0% +will see many many instances of what of +what I'm calling the multiplicity + + align:start position:0% +what I'm calling the multiplicity + + + align:start position:0% +what I'm calling the multiplicity +principle in Katon's work and you will + + align:start position:0% +principle in Katon's work and you will + + + align:start position:0% +principle in Katon's work and you will +especially see it in these astonishing + + align:start position:0% +especially see it in these astonishing + + + align:start position:0% +especially see it in these astonishing +repeated + + align:start position:0% +repeated + + + align:start position:0% +repeated +um uh uh sequences in which we see in + + align:start position:0% +um uh uh sequences in which we see in + + + align:start position:0% +um uh uh sequences in which we see in +which we see the and I'm talking now in + + align:start position:0% +which we see the and I'm talking now in + + + align:start position:0% +which we see the and I'm talking now in +a way about the general in which we see + + align:start position:0% +a way about the general in which we see + + + align:start position:0% +a way about the general in which we see +the Katon hero who sort of uh is + + align:start position:0% +the Katon hero who sort of uh is + + + align:start position:0% +the Katon hero who sort of uh is +steadfast but also a muddler. He keeps + + align:start position:0% +steadfast but also a muddler. He keeps + + + align:start position:0% +steadfast but also a muddler. He keeps +he keeps doing the same things. they're + + align:start position:0% +he keeps doing the same things. they're + + + align:start position:0% +he keeps doing the same things. they're +not really likely to help him and then + + align:start position:0% +not really likely to help him and then + + + align:start position:0% +not really likely to help him and then +he gets help from the outside and was + + align:start position:0% +he gets help from the outside and was + + + align:start position:0% +he gets help from the outside and was +what what Keaton's jokes repeatedly + + align:start position:0% +what what Keaton's jokes repeatedly + + + align:start position:0% +what what Keaton's jokes repeatedly +depend upon the idea of of uh accident + + align:start position:0% +depend upon the idea of of uh accident + + + align:start position:0% +depend upon the idea of of uh accident +in a certain way and I I'll come back to + + align:start position:0% +in a certain way and I I'll come back to + + + align:start position:0% +in a certain way and I I'll come back to +that in finally in a second. So so think + + align:start position:0% +that in finally in a second. So so think + + + align:start position:0% +that in finally in a second. So so think +about the multiplicity principle the + + align:start position:0% +about the multiplicity principle the + + + align:start position:0% +about the multiplicity principle the +difference between entertainment and art + + align:start position:0% +difference between entertainment and art + + + align:start position:0% +difference between entertainment and art +again this is a principle I'll come back + + align:start position:0% +again this is a principle I'll come back + + + align:start position:0% +again this is a principle I'll come back +to and try to illustrate with greater uh + + align:start position:0% +to and try to illustrate with greater uh + + + align:start position:0% +to and try to illustrate with greater uh +uh concreteness and greater leisure in + + align:start position:0% +uh concreteness and greater leisure in + + + align:start position:0% +uh concreteness and greater leisure in +later lectures but I want you to be + + align:start position:0% +later lectures but I want you to be + + + align:start position:0% +later lectures but I want you to be +aware of these of these issues. So the + + align:start position:0% +aware of these of these issues. So the + + + align:start position:0% +aware of these of these issues. So the +general can be understood as a kind of + + align:start position:0% +general can be understood as a kind of + + + align:start position:0% +general can be understood as a kind of +culminating text in at least two ways. + + align:start position:0% +culminating text in at least two ways. + + + align:start position:0% +culminating text in at least two ways. +It's a culmination of Katon's career. + + align:start position:0% +It's a culmination of Katon's career. + + + align:start position:0% +It's a culmination of Katon's career. +That is to say, the jokes and gags that + + align:start position:0% +That is to say, the jokes and gags that + + + align:start position:0% +That is to say, the jokes and gags that +are enacted in in uh in the film recall + + align:start position:0% +are enacted in in uh in the film recall + + + align:start position:0% +are enacted in in uh in the film recall +many earlier Katon films. And the basic + + align:start position:0% +many earlier Katon films. And the basic + + + align:start position:0% +many earlier Katon films. And the basic +character of the general is the basic + + align:start position:0% +character of the general is the basic + + + align:start position:0% +character of the general is the basic +character of the Katon hero. a + + align:start position:0% +character of the Katon hero. a + + + align:start position:0% +character of the Katon hero. a +steadfast, unremarkable young man who + + align:start position:0% +steadfast, unremarkable young man who + + + align:start position:0% +steadfast, unremarkable young man who +perseveres in the face of catastrophic + + align:start position:0% +perseveres in the face of catastrophic + + + align:start position:0% +perseveres in the face of catastrophic +difficulties with mostly comic + + align:start position:0% +difficulties with mostly comic + + + align:start position:0% +difficulties with mostly comic +expectations, very small expectations of + + align:start position:0% +expectations, very small expectations of + + + align:start position:0% +expectations, very small expectations of +success, who often muddles through + + align:start position:0% +success, who often muddles through + + + align:start position:0% +success, who often muddles through +almost despite himself right now. But it + + align:start position:0% +almost despite himself right now. But it + + + align:start position:0% +almost despite himself right now. But it +isn't merely, but I say almost despite + + align:start position:0% +isn't merely, but I say almost despite + + + align:start position:0% +isn't merely, but I say almost despite +himself and this is where the complexity + + align:start position:0% +himself and this is where the complexity + + + align:start position:0% +himself and this is where the complexity +of Katon's vision of life comes in. Why + + align:start position:0% +of Katon's vision of life comes in. Why + + + align:start position:0% +of Katon's vision of life comes in. Why +I'm saying that Katon moves from being + + align:start position:0% +I'm saying that Katon moves from being + + + align:start position:0% +I'm saying that Katon moves from being +merely a jokester or being merely a + + align:start position:0% +merely a jokester or being merely a + + + align:start position:0% +merely a jokester or being merely a +great entertainer to being an artist. + + align:start position:0% +great entertainer to being an artist. + + + align:start position:0% +great entertainer to being an artist. +His jokes embody an idea of what + + align:start position:0% +His jokes embody an idea of what + + + align:start position:0% +His jokes embody an idea of what +experience is like and it's a very + + align:start position:0% +experience is like and it's a very + + + align:start position:0% +experience is like and it's a very +powerful mortant mature idea of + + align:start position:0% +powerful mortant mature idea of + + + align:start position:0% +powerful mortant mature idea of +experience because what happens again + + align:start position:0% +experience because what happens again + + + align:start position:0% +experience because what happens again +and again in the small jokes the + + align:start position:0% +and again in the small jokes the + + + align:start position:0% +and again in the small jokes the +sequence jokes in Katon's work + + align:start position:0% +sequence jokes in Katon's work + + + align:start position:0% +sequence jokes in Katon's work +especially in the general and in the + + align:start position:0% +especially in the general and in the + + + align:start position:0% +especially in the general and in the +larger film what happens again and again + + align:start position:0% +larger film what happens again and again + + + align:start position:0% +larger film what happens again and again +is a is a an adventure in which a + + align:start position:0% +is a is a an adventure in which a + + + align:start position:0% +is a is a an adventure in which a +steadfast relentless young hero does + + align:start position:0% +steadfast relentless young hero does + + + align:start position:0% +steadfast relentless young hero does +everything he can to to uh accomplish + + align:start position:0% +everything he can to to uh accomplish + + + align:start position:0% +everything he can to to uh accomplish +his goal and it's obvious that he's up + + align:start position:0% +his goal and it's obvious that he's up + + + align:start position:0% +his goal and it's obvious that he's up +against forces far beyond himself that + + align:start position:0% +against forces far beyond himself that + + + align:start position:0% +against forces far beyond himself that +he could never that there's a + + align:start position:0% +he could never that there's a + + + align:start position:0% +he could never that there's a +unbelievable mis mismatch between this + + align:start position:0% +unbelievable mis mismatch between this + + + align:start position:0% +unbelievable mis mismatch between this +minuscule tiny figure and the and his + + align:start position:0% +minuscule tiny figure and the and his + + + align:start position:0% +minuscule tiny figure and the and his +powers and the forces he's he's fighting + + align:start position:0% +powers and the forces he's he's fighting + + + align:start position:0% +powers and the forces he's he's fighting +against. There's one Katon film called + + align:start position:0% +against. There's one Katon film called + + + align:start position:0% +against. There's one Katon film called +the navigator in which the Keaton + + align:start position:0% +the navigator in which the Keaton + + + align:start position:0% +the navigator in which the Keaton +character even more than with the + + align:start position:0% +character even more than with the + + + align:start position:0% +character even more than with the +locomotive in the general has to + + align:start position:0% +locomotive in the general has to + + + align:start position:0% +locomotive in the general has to +navigate an ocean liner and he's alone + + align:start position:0% +navigate an ocean liner and he's alone + + + align:start position:0% +navigate an ocean liner and he's alone +on the ocean liner and you see him + + align:start position:0% +on the ocean liner and you see him + + + align:start position:0% +on the ocean liner and you see him +running up and down into the engine room + + align:start position:0% +running up and down into the engine room + + + align:start position:0% +running up and down into the engine room +back up to this up to the bridge not + + align:start position:0% +back up to this up to the bridge not + + + align:start position:0% +back up to this up to the bridge not +running all over the ocean liner in a in + + align:start position:0% +running all over the ocean liner in a in + + + align:start position:0% +running all over the ocean liner in a in +a in in great difficulties. There's a + + align:start position:0% +a in in great difficulties. There's a + + + align:start position:0% +a in in great difficulties. There's a +wonderful film, late film made in 1928, + + align:start position:0% +wonderful film, late film made in 1928, + + + align:start position:0% +wonderful film, late film made in 1928, +just the his last silent film called + + align:start position:0% +just the his last silent film called + + + align:start position:0% +just the his last silent film called +Steamboat Bill Jr. in which he + + align:start position:0% +Steamboat Bill Jr. in which he + + + align:start position:0% +Steamboat Bill Jr. in which he +dramatizes an astonishing song, an + + align:start position:0% +dramatizes an astonishing song, an + + + align:start position:0% +dramatizes an astonishing song, an +astonishing an astonishing um uh + + align:start position:0% +astonishing an astonishing um uh + + + align:start position:0% +astonishing an astonishing um uh +hurricane uh and a long extended + + align:start position:0% +hurricane uh and a long extended + + + align:start position:0% +hurricane uh and a long extended +sequence in which we see him trying to + + align:start position:0% +sequence in which we see him trying to + + + align:start position:0% +sequence in which we see him trying to +escape the hurricane uh trying to + + align:start position:0% +escape the hurricane uh trying to + + + align:start position:0% +escape the hurricane uh trying to +contend against this natural force + + align:start position:0% +contend against this natural force + + + align:start position:0% +contend against this natural force +that's so gigantic. So the the so so the + + align:start position:0% +that's so gigantic. So the the so so the + + + align:start position:0% +that's so gigantic. So the the so so the +the general is a culmination in the + + align:start position:0% +the general is a culmination in the + + + align:start position:0% +the general is a culmination in the +sense that it gives us another version + + align:start position:0% +sense that it gives us another version + + + align:start position:0% +sense that it gives us another version +and the the richest the richest version + + align:start position:0% +and the the richest the richest version + + + align:start position:0% +and the the richest the richest version +so far of the of the adventures of this + + align:start position:0% +so far of the of the adventures of this + + + align:start position:0% +so far of the of the adventures of this +kind of Katon hero. But what makes it a + + align:start position:0% +kind of Katon hero. But what makes it a + + + align:start position:0% +kind of Katon hero. But what makes it a +what what makes it sort of metaphysical + + align:start position:0% +what what makes it sort of metaphysical + + + align:start position:0% +what what makes it sort of metaphysical +or philosophically interesting is that + + align:start position:0% +or philosophically interesting is that + + + align:start position:0% +or philosophically interesting is that +what what this joke repeatedly does and + + align:start position:0% +what what this joke repeatedly does and + + + align:start position:0% +what what this joke repeatedly does and +what the structure of the whole film + + align:start position:0% +what the structure of the whole film + + + align:start position:0% +what the structure of the whole film +repeatedly says is something like this. + + align:start position:0% +repeatedly says is something like this. + + + align:start position:0% +repeatedly says is something like this. +We get through we make it through life + + align:start position:0% +We get through we make it through life + + + align:start position:0% +We get through we make it through life +not mo mostly it's a it's a great comic + + align:start position:0% +not mo mostly it's a it's a great comic + + + align:start position:0% +not mo mostly it's a it's a great comic +Morton comic. We get through life mostly + + align:start position:0% +Morton comic. We get through life mostly + + + align:start position:0% +Morton comic. We get through life mostly +not because of anything we've done but + + align:start position:0% +not because of anything we've done but + + + align:start position:0% +not because of anything we've done but +because of accident. We live in a + + align:start position:0% +because of accident. We live in a + + + align:start position:0% +because of accident. We live in a +contingent universe. Right? The idea of + + align:start position:0% +contingent universe. Right? The idea of + + + align:start position:0% +contingent universe. Right? The idea of +contingency is at the heart of what of + + align:start position:0% +contingency is at the heart of what of + + + align:start position:0% +contingency is at the heart of what of +of of Katon's jokes. We could we could + + align:start position:0% +of of Katon's jokes. We could we could + + + align:start position:0% +of of Katon's jokes. We could we could +call them jokes about contingency. The + + align:start position:0% +call them jokes about contingency. The + + + align:start position:0% +call them jokes about contingency. The +word contingent is interesting. Remember + + align:start position:0% +word contingent is interesting. Remember + + + align:start position:0% +word contingent is interesting. Remember +it means both li it means liable but not + + align:start position:0% +it means both li it means liable but not + + + align:start position:0% +it means both li it means liable but not +certain but not certain to occur. It + + align:start position:0% +certain but not certain to occur. It + + + align:start position:0% +certain but not certain to occur. It +means possible. Right? So, so uh for + + align:start position:0% +means possible. Right? So, so uh for + + + align:start position:0% +means possible. Right? So, so uh for +it's it means dependent upon subject to + + align:start position:0% +it's it means dependent upon subject to + + + align:start position:0% +it's it means dependent upon subject to +conditioned by right in law you could + + align:start position:0% +conditioned by right in law you could + + + align:start position:0% +conditioned by right in law you could +say something uh you can say that + + align:start position:0% +say something uh you can say that + + + align:start position:0% +say something uh you can say that +something that is contingent is + + align:start position:0% +something that is contingent is + + + align:start position:0% +something that is contingent is +dependent for its effect on something + + align:start position:0% +dependent for its effect on something + + + align:start position:0% +dependent for its effect on something +that may or may not occur as in a + + align:start position:0% +that may or may not occur as in a + + + align:start position:0% +that may or may not occur as in a +contingent estate or legacy right in + + align:start position:0% +contingent estate or legacy right in + + + align:start position:0% +contingent estate or legacy right in +logic the same thing dependent upon some + + align:start position:0% +logic the same thing dependent upon some + + + align:start position:0% +logic the same thing dependent upon some +condition or upon the truth of something + + align:start position:0% +condition or upon the truth of something + + + align:start position:0% +condition or upon the truth of something +else not true a priori not necessary so + + align:start position:0% +else not true a priori not necessary so + + + align:start position:0% +else not true a priori not necessary so +what keaton's jokes constantly do is + + align:start position:0% +what keaton's jokes constantly do is + + + align:start position:0% +what keaton's jokes constantly do is +they show us two things. They show us a + + align:start position:0% +they show us two things. They show us a + + + align:start position:0% +they show us two things. They show us a +world in which human agency matters. + + align:start position:0% +world in which human agency matters. + + + align:start position:0% +world in which human agency matters. +Because if this schmenrich didn't keep, + + align:start position:0% +Because if this schmenrich didn't keep, + + + align:start position:0% +Because if this schmenrich didn't keep, +that's a Jewish word for schlamazle. + + align:start position:0% +that's a Jewish word for schlamazle. + + + align:start position:0% +that's a Jewish word for schlamazle. +It's a clown. If this schmenrich did not + + align:start position:0% +It's a clown. If this schmenrich did not + + + align:start position:0% +It's a clown. If this schmenrich did not +if this schmenrich did not um keep on so + + align:start position:0% +if this schmenrich did not um keep on so + + + align:start position:0% +if this schmenrich did not um keep on so +steadfastly, he wouldn't survive. But + + align:start position:0% +steadfastly, he wouldn't survive. But + + + align:start position:0% +steadfastly, he wouldn't survive. But +his keeping on so steadfastly still + + align:start position:0% +his keeping on so steadfastly still + + + align:start position:0% +his keeping on so steadfastly still +wouldn't make him survive if there + + align:start position:0% +wouldn't make him survive if there + + + align:start position:0% +wouldn't make him survive if there +weren't the intervention of mere + + align:start position:0% +weren't the intervention of mere + + + align:start position:0% +weren't the intervention of mere +accidents, stuff he has no control over. + + align:start position:0% +accidents, stuff he has no control over. + + + align:start position:0% +accidents, stuff he has no control over. +There's one magnificent moment in the in + + align:start position:0% +There's one magnificent moment in the in + + + align:start position:0% +There's one magnificent moment in the in +in one week for example where he's + + align:start position:0% +in one week for example where he's + + + align:start position:0% +in one week for example where he's +standing in a certain place and the + + align:start position:0% +standing in a certain place and the + + + align:start position:0% +standing in a certain place and the +house and the house behind him falls + + align:start position:0% +house and the house behind him falls + + + align:start position:0% +house and the house behind him falls +down and he happens just by accident to + + align:start position:0% +down and he happens just by accident to + + + align:start position:0% +down and he happens just by accident to +be standing so that by the open window + + align:start position:0% +be standing so that by the open window + + + align:start position:0% +be standing so that by the open window +the house falls so he doesn't get hurt. + + align:start position:0% +the house falls so he doesn't get hurt. + + + align:start position:0% +the house falls so he doesn't get hurt. +He used this joke more than once in + + align:start position:0% +He used this joke more than once in + + + align:start position:0% +He used this joke more than once in +other films because such a great one. + + align:start position:0% +other films because such a great one. + + + align:start position:0% +other films because such a great one. +But it's a perfect example of what I + + align:start position:0% +But it's a perfect example of what I + + + align:start position:0% +But it's a perfect example of what I +mean. A partial example of what I mean + + align:start position:0% +mean. A partial example of what I mean + + + align:start position:0% +mean. A partial example of what I mean +because he's not responsible for the + + align:start position:0% +because he's not responsible for the + + + align:start position:0% +because he's not responsible for the +fact that he escaped. On the other hand, + + align:start position:0% +fact that he escaped. On the other hand, + + + align:start position:0% +fact that he escaped. On the other hand, +because he was trying to get away from + + align:start position:0% +because he was trying to get away from + + + align:start position:0% +because he was trying to get away from +difficulties, maybe he was in that + + align:start position:0% +difficulties, maybe he was in that + + + align:start position:0% +difficulties, maybe he was in that +particular position because of acts of + + align:start position:0% +particular position because of acts of + + + align:start position:0% +particular position because of acts of +his own. So, so what it says what what + + align:start position:0% +his own. So, so what it says what what + + + align:start position:0% +his own. So, so what it says what what +so what this joking vision says about + + align:start position:0% +so what this joking vision says about + + + align:start position:0% +so what this joking vision says about +the world is something that's true. We + + align:start position:0% +the world is something that's true. We + + + align:start position:0% +the world is something that's true. We +all love the idea that we've gotten to + + align:start position:0% +all love the idea that we've gotten to + + + align:start position:0% +all love the idea that we've gotten to +where we are by our own acts, by our own + + align:start position:0% +where we are by our own acts, by our own + + + align:start position:0% +where we are by our own acts, by our own +conscious control. The truth of the + + align:start position:0% +conscious control. The truth of the + + + align:start position:0% +conscious control. The truth of the +matter is that life that life is much + + align:start position:0% +matter is that life that life is much + + + align:start position:0% +matter is that life that life is much +more contingent than that. It's partly + + align:start position:0% +more contingent than that. It's partly + + + align:start position:0% +more contingent than that. It's partly +accident. It's partly luck. And + + align:start position:0% +accident. It's partly luck. And + + + align:start position:0% +accident. It's partly luck. And +something deeper than that. Keaton's + + align:start position:0% +something deeper than that. Keaton's + + + align:start position:0% +something deeper than that. Keaton's +vision of the universe is one which + + align:start position:0% +vision of the universe is one which + + + align:start position:0% +vision of the universe is one which +suggests that while the universe may + + align:start position:0% +suggests that while the universe may + + + align:start position:0% +suggests that while the universe may +screw you up sometimes, it won't always + + align:start position:0% +screw you up sometimes, it won't always + + + align:start position:0% +screw you up sometimes, it won't always +do that. That is to say, it's not the + + align:start position:0% +do that. That is to say, it's not the + + + align:start position:0% +do that. That is to say, it's not the +universe in Katon's world is not angry + + align:start position:0% +universe in Katon's world is not angry + + + align:start position:0% +universe in Katon's world is not angry +at us. It's indifferent to us. It + + align:start position:0% +at us. It's indifferent to us. It + + + align:start position:0% +at us. It's indifferent to us. It +doesn't give a damn about us. It's not + + align:start position:0% +doesn't give a damn about us. It's not + + + align:start position:0% +doesn't give a damn about us. It's not +aware of us. It's too big for us. Right? + + align:start position:0% +aware of us. It's too big for us. Right? + + + align:start position:0% +aware of us. It's too big for us. Right? +You can't come away from Katon's films + + align:start position:0% +You can't come away from Katon's films + + + align:start position:0% +You can't come away from Katon's films +without a simultaneous sense of the + + align:start position:0% +without a simultaneous sense of the + + + align:start position:0% +without a simultaneous sense of the +importance of human action of human + + align:start position:0% +importance of human action of human + + + align:start position:0% +importance of human action of human +agency but also of the inadequacy of + + align:start position:0% +agency but also of the inadequacy of + + + align:start position:0% +agency but also of the inadequacy of +human agency of how contingent every + + align:start position:0% +human agency of how contingent every + + + align:start position:0% +human agency of how contingent every +experience every adventure every + + align:start position:0% +experience every adventure every + + + align:start position:0% +experience every adventure every +personality is and that and that meaning + + align:start position:0% +personality is and that and that meaning + + + align:start position:0% +personality is and that and that meaning +that idea of the world is a profound one + + align:start position:0% +that idea of the world is a profound one + + + align:start position:0% +that idea of the world is a profound one +I think it tells so that so that even + + align:start position:0% +I think it tells so that so that even + + + align:start position:0% +I think it tells so that so that even +though Keaton is telling a joke embedded + + align:start position:0% +though Keaton is telling a joke embedded + + + align:start position:0% +though Keaton is telling a joke embedded +in the joke is a kind of interpretation + + align:start position:0% +in the joke is a kind of interpretation + + + align:start position:0% +in the joke is a kind of interpretation +of life and embedded in the film is a + + align:start position:0% +of life and embedded in the film is a + + + align:start position:0% +of life and embedded in the film is a +kind interpretation of life. Uh when + + align:start position:0% +kind interpretation of life. Uh when + + + align:start position:0% +kind interpretation of life. Uh when +you're looking at the general, I think + + align:start position:0% +you're looking at the general, I think + + + align:start position:0% +you're looking at the general, I think +you will see multiple examples of this + + align:start position:0% +you will see multiple examples of this + + + align:start position:0% +you will see multiple examples of this +kind of thing. Let me say one last + + align:start position:0% +kind of thing. Let me say one last + + + align:start position:0% +kind of thing. Let me say one last +thing. I haven't mentioned anything + + align:start position:0% +thing. I haven't mentioned anything + + + align:start position:0% +thing. I haven't mentioned anything +about the structure of the film. I'm a + + align:start position:0% +about the structure of the film. I'm a + + + align:start position:0% +about the structure of the film. I'm a +little out of order there. Watch how the + + align:start position:0% +little out of order there. Watch how the + + + align:start position:0% +little out of order there. Watch how the +film is structured. It it's a ve it's a + + align:start position:0% +film is structured. It it's a ve it's a + + + align:start position:0% +film is structured. It it's a ve it's a +much more complex variation on what I + + align:start position:0% +much more complex variation on what I + + + align:start position:0% +much more complex variation on what I +said about Lonale Operator. The film + + align:start position:0% +said about Lonale Operator. The film + + + align:start position:0% +said about Lonale Operator. The film +begins with him going up the track and + + align:start position:0% +begins with him going up the track and + + + align:start position:0% +begins with him going up the track and +then the second half of the film has him + + align:start position:0% +then the second half of the film has him + + + align:start position:0% +then the second half of the film has him +going back down the track. You may not + + align:start position:0% +going back down the track. You may not + + + align:start position:0% +going back down the track. You may not +be aware of it, but actually the film in + + align:start position:0% +be aware of it, but actually the film in + + + align:start position:0% +be aware of it, but actually the film in +a certain sense has its tail in its + + align:start position:0% +a certain sense has its tail in its + + + align:start position:0% +a certain sense has its tail in its +mouth. When it goes up the track, he has + + align:start position:0% +mouth. When it goes up the track, he has + + + align:start position:0% +mouth. When it goes up the track, he has +a series of adventures. When he comes + + align:start position:0% +a series of adventures. When he comes + + + align:start position:0% +a series of adventures. When he comes +back down, he has a series of adventures + + align:start position:0% +back down, he has a series of adventures + + + align:start position:0% +back down, he has a series of adventures +that in a certain sense replicate what's + + align:start position:0% +that in a certain sense replicate what's + + + align:start position:0% +that in a certain sense replicate what's +happened before. The film mirrors itself + + align:start position:0% +happened before. The film mirrors itself + + + align:start position:0% +happened before. The film mirrors itself +in a way repeats itself. Watch. It's an + + align:start position:0% +in a way repeats itself. Watch. It's an + + + align:start position:0% +in a way repeats itself. Watch. It's an +incredibly elegant structure. It's + + align:start position:0% +incredibly elegant structure. It's + + + align:start position:0% +incredibly elegant structure. It's +incred and and the elegance of the + + align:start position:0% +incred and and the elegance of the + + + align:start position:0% +incred and and the elegance of the +structure reminds us also uh of the in + + align:start position:0% +structure reminds us also uh of the in + + + align:start position:0% +structure reminds us also uh of the in +its own way also reminds us of this + + align:start position:0% +its own way also reminds us of this + + + align:start position:0% +its own way also reminds us of this +principle of contingency that's at the + + align:start position:0% +principle of contingency that's at the + + + align:start position:0% +principle of contingency that's at the +heart of Keaton's vision of the world. + + align:start position:0% +heart of Keaton's vision of the world. + + + align:start position:0% +heart of Keaton's vision of the world. +Let me conclude by reminding you again + + align:start position:0% +Let me conclude by reminding you again + + + align:start position:0% +Let me conclude by reminding you again +of what I said earlier. When I call + + align:start position:0% +of what I said earlier. When I call + + + align:start position:0% +of what I said earlier. When I call +Katon a philosopher and a metaphysician + + align:start position:0% +Katon a philosopher and a metaphysician + + + align:start position:0% +Katon a philosopher and a metaphysician +and a wise person about the world, I do + + align:start position:0% +and a wise person about the world, I do + + + align:start position:0% +and a wise person about the world, I do +not at all mean to suggest that if you + + align:start position:0% +not at all mean to suggest that if you + + + align:start position:0% +not at all mean to suggest that if you +ask Keaton to explain how he thought + + align:start position:0% +ask Keaton to explain how he thought + + + align:start position:0% +ask Keaton to explain how he thought +about the world, he could do this. + + align:start position:0% +about the world, he could do this. + + + align:start position:0% +about the world, he could do this. +That's that's the job of professors and + + align:start position:0% +That's that's the job of professors and + + + align:start position:0% +That's that's the job of professors and +literary and film critics. Right? What + + align:start position:0% +literary and film critics. Right? What + + + align:start position:0% +literary and film critics. Right? What +I'm saying to you is that Keaton like + + align:start position:0% +I'm saying to you is that Keaton like + + + align:start position:0% +I'm saying to you is that Keaton like +many great artists had an intuitive + + align:start position:0% +many great artists had an intuitive + + + align:start position:0% +many great artists had an intuitive +understanding of the world which he + + align:start position:0% +understanding of the world which he + + + align:start position:0% +understanding of the world which he +expressed with greater and greater + + align:start position:0% +expressed with greater and greater + + + align:start position:0% +expressed with greater and greater +complexity in the medium of the cinema. + + align:start position:0% +complexity in the medium of the cinema. + + + align:start position:0% +complexity in the medium of the cinema. +And in the general we have what is + + align:start position:0% +And in the general we have what is + + + align:start position:0% +And in the general we have what is +ultimately a culminating instance of + + align:start position:0% +ultimately a culminating instance of + + + align:start position:0% +ultimately a culminating instance of +that. One last point about the film as a + + align:start position:0% +that. One last point about the film as a + + + align:start position:0% +that. One last point about the film as a +culminating example. It's not just a + + align:start position:0% +culminating example. It's not just a + + + align:start position:0% +culminating example. It's not just a +culmination of Katon's career. It's a + + align:start position:0% +culmination of Katon's career. It's a + + + align:start position:0% +culmination of Katon's career. It's a +culmination of silent film in it in it + + align:start position:0% +culmination of silent film in it in it + + + align:start position:0% +culmination of silent film in it in it +in as a whole. Katon would have expected + + align:start position:0% +in as a whole. Katon would have expected + + + align:start position:0% +in as a whole. Katon would have expected +his audience to recognize the degree to + + align:start position:0% +his audience to recognize the degree to + + + align:start position:0% +his audience to recognize the degree to +which this film was a parody or a + + align:start position:0% +which this film was a parody or a + + + align:start position:0% +which this film was a parody or a +mockery of famous historical films made + + align:start position:0% +mockery of famous historical films made + + + align:start position:0% +mockery of famous historical films made +by DW Griffith. It puts down the + + align:start position:0% +by DW Griffith. It puts down the + + + align:start position:0% +by DW Griffith. It puts down the +pretentiousness and the Marshall valor + + align:start position:0% +pretentiousness and the Marshall valor + + + align:start position:0% +pretentiousness and the Marshall valor +that's celebrated in so many of the + + align:start position:0% +that's celebrated in so many of the + + + align:start position:0% +that's celebrated in so many of the +historical spectacles that Griffith and + + align:start position:0% +historical spectacles that Griffith and + + + align:start position:0% +historical spectacles that Griffith and +other serious directors were making at + + align:start position:0% +other serious directors were making at + + + align:start position:0% +other serious directors were making at +the time. Uh and it and it also goes + + align:start position:0% +the time. Uh and it and it also goes + + + align:start position:0% +the time. Uh and it and it also goes +back in a certain way to the very roots + + align:start position:0% +back in a certain way to the very roots + + + align:start position:0% +back in a certain way to the very roots +of film. What was the very first + + align:start position:0% +of film. What was the very first + + + align:start position:0% +of film. What was the very first +narrative film or one of the very first + + align:start position:0% +narrative film or one of the very first + + + align:start position:0% +narrative film or one of the very first +the uh also a film about a train + + align:start position:0% +the uh also a film about a train + + + align:start position:0% +the uh also a film about a train +robbery, right? Called the great train + + align:start position:0% +robbery, right? Called the great train + + + align:start position:0% +robbery, right? Called the great train +robbery. Well, this is about a train + + align:start position:0% +robbery. Well, this is about a train + + + align:start position:0% +robbery. Well, this is about a train +robbery too. And who is the central + + align:start position:0% +robbery too. And who is the central + + + align:start position:0% +robbery too. And who is the central +character in this film? Really? A train + + align:start position:0% +character in this film? Really? A train + + + align:start position:0% +character in this film? Really? A train +is the central object, the central more + + align:start position:0% +is the central object, the central more + + + align:start position:0% +is the central object, the central more +interesting in some ways than the + + align:start position:0% +interesting in some ways than the + + + align:start position:0% +interesting in some ways than the +character himself. this and there are + + align:start position:0% +character himself. this and there are + + + align:start position:0% +character himself. this and there are +many other ways in which the particular + + align:start position:0% +many other ways in which the particular + + + align:start position:0% +many other ways in which the particular +features of the general allude to and in + + align:start position:0% +features of the general allude to and in + + + align:start position:0% +features of the general allude to and in +some sense summarize the history of + + align:start position:0% +some sense summarize the history of + + + align:start position:0% +some sense summarize the history of +silent film and all of the original + + align:start position:0% +silent film and all of the original + + + align:start position:0% +silent film and all of the original +audience coming to see the general would + + align:start position:0% +audience coming to see the general would + + + align:start position:0% +audience coming to see the general would +have been of course alert to these + + align:start position:0% +have been of course alert to these + + + align:start position:0% +have been of course alert to these +connections would have been literate in + + align:start position:0% +connections would have been literate in + + + align:start position:0% +connections would have been literate in +these connections wouldn't have needed + + align:start position:0% +these connections wouldn't have needed + + + align:start position:0% +these connections wouldn't have needed +footnotes or professors to tell them + + align:start position:0% +footnotes or professors to tell them + + + align:start position:0% +footnotes or professors to tell them +about it because they would have lived + + align:start position:0% +about it because they would have lived + + + align:start position:0% +about it because they would have lived +through the history they would have + + align:start position:0% +through the history they would have + + + align:start position:0% +through the history they would have +lived through the history of the + + align:start position:0% +lived through the history of the + + + align:start position:0% +lived through the history of the +previous 20 years they would have seen + + align:start position:0% +previous 20 years they would have seen + + + align:start position:0% +previous 20 years they would have seen +other Keaton films they would have seen + + align:start position:0% +other Keaton films they would have seen + + + align:start position:0% +other Keaton films they would have seen +DW Griffith they would have the history + + align:start position:0% +DW Griffith they would have the history + + + align:start position:0% +DW Griffith they would have the history +of the of the uh medium of movies in + + align:start position:0% +of the of the uh medium of movies in + + + align:start position:0% +of the of the uh medium of movies in +their heads when they sat down to watch + + align:start position:0% +their heads when they sat down to watch + + + align:start position:0% +their heads when they sat down to watch +The General. So that's another way in + + align:start position:0% +The General. So that's another way in + + + align:start position:0% +The General. So that's another way in +which The General is a profoundly + + align:start position:0% +which The General is a profoundly + + + align:start position:0% +which The General is a profoundly +culminating text. \ No newline at end of file diff --git a/wCSl5eeMSDY.txt b/wCSl5eeMSDY.txt new file mode 100644 index 0000000000000000000000000000000000000000..86e02001432a0d6aef94110fefcb49f70c200445 --- /dev/null +++ b/wCSl5eeMSDY.txt @@ -0,0 +1,2232 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: So last +time you learned + +about the ideal solution limits +with Henry's law and Raoult's + +law. + +And I just want to start +with one reminder of what + +this is all about. + +So let's say that you have a +mixture of CS2 and acetone. + +So this is a review of +what you saw last time. + +Acetone like this, CH3, CH3. + +And if you take the CS2 as +the solvent and the acetone + +as a solute, then when you plot +as a function of the amount + +of CS2 here as a +solvent, then you + +have the limit where the mole +fraction of CS2 goes to one, + +meaning that CS is the solvent. + +You expect Raoult to work +if it's an ideal solution. + +So that the vapor +pressure of CS2 + +is related to the mole +fraction of CS2 times the vapor + +pressure of CS2 if it was pure. + +So you're sitting +here somewhere. + +This is the vapor +pressure of CS2 pure + +and CS2 goes from zero to one. + +And you expect Raoult to work. + +So let's do Raoult. + +Like this. + +So in this area, if I were +to plot the real curve, + +I would expect it to start +out just like Raoult. + +And then there's going +to be some deviation. + +Then if I take the other limit, +where the mole fraction of CS2 + +goes to zero. + +So now the CS2 is the solute. + +And the acetone is +the solvent. what + +happens for this +particular mixture is + +that Henry's law +is no longer valid. + +Raoult's law is not valid here. + +Instead, you have to +look at Henry's law. + +And Henry's law tells you +that for the solute now, + +not the solvent, +so the CS2 here is + +the solute, very +small amount of it. + +Very small mole fraction. + +That the vapor +pressure of the solute + +is related to the mole +fraction in the solution. + +But instead of having the vapor +pressure of the pure solute, + +you have another number. + +Another constant. + +Which we call K. Which is +a Henry's law constant. + +And this constant depends on +what else in the solution. + +It depends on the fact that +you have acetone in there. + +You would have a +different constant + +if the acetone were replaced +with chloroform, let's say. + +So this constant here +cares what the solvent is. + +And it cares what the +temperature is, also. + +There's a lot of stuff that's +built into this constant here. + +It's a phinemelogical constant. + +And in the case of the +mixture of CS2 and acetone, + +the deviation from +Raoult's law is positive. + +Meaning that the +Henry's law constant + +is greater than the vapor +pressure of the pure CS2. + +So that means that +the molecules of CS2 + +would rather go +in the gas phase. + +If there's acetone around. + +That means they don't +like to mix so much. + +They're not happy +with each other. + +So the CS2 molecules +would rather + +escape what would normally be +a Raoult's law type of solution + +to go in the gas phase away +from being close to the acetone. + +And as a result you get +this positive deviation. + +You get a higher pressure than +you expect from Raoult's law. + +So that the slope here +This slope here is K CS2. + +And that slope +here is p star CS2. + +This is a positive deviation. + +And you saw an example where +you if you mix chloroform + +and acetone, you get +a negative deviation. + +Chloroform and acetone +are happy together + +because of the hydrogen +bonding between the oxygen here + +and the hydrogen in chloroform. + +And you get a +negative deviation. + +So let's start by doing +an example with numbers. + +Of how this might come about. + +Any questions on this first? + +I always got confused with +Henry's law and Raoult's law. + +And I always got +confused as to when + +I was supposed to +use Henry's law + +and when I was supposed +to use Raoult's law. + +Very confusing to me, initially. + +The thing to remember +is that if you're + +talking about something which +in a very small amount, just + +the solute, like, well I'm going +to give you an example which + +is a bad example, +like sugar and water. + +Where sugar is +clearly the solute, + +but sugar is not volatile +clearly this is a bad example. + +But something which in a very +small concentration, then + +Henry's law is going to apply. + +Raoult's law is only going +to apply for the solvent. + +When you have a lot +of stuff around. + +On this side here +is Raoult's law. + +On this side here +is Henry's law. + +Henry's law, the deviation's +from Raoult's law, + +are going to happen where +the molecules in the solution + +mostly see molecules that +are not like themselves. + +If they mostly see +molecules like themselves, + +since it's an ideal +solution, then they + +don't know that there's +other stuff around. + +In this case here, the CS2 +molecules don't really know. + +Most of them don't know that +there's any acetone around. + +They couldn't care less. + +So it obeys an ideal solution. + +Here, they don't see +any other CS2 molecules. + +They mostly see acetone. + +And so Raoult's law is +going to fall apart. + +Because Raoult's +law assumed that you + +have a single component. + +Or mostly one component. + +OK. + +Let's do an example. + +So in this case +here, we're going + +to work the example out here. + +So let's take two +components, A and B. Where + +B is, and let's look +at something which + +is a dilute solution +and non-ideal. + +So there's going to be some +deviation from Raoult's law. + +And what we're told +is at 50 degrees + +Celsius, that the vapor pressure +of pure A is equal to 0.67 bar. + +And the vapor pressure of +pure B is equal to 1.2 bar. + +So B is clearly +the more volatile. + +And we're also told, +then, that at 50 degrees + +C we have a molar fraction of +A in the liquid phase is 0.9. + +And the molar fraction of B +in the liquid phase is 0.1. + +And the total pressure above +the solution is 0.7 bar. + +And eventually what we're +going to try to find out is, + +we're going to change +these concentrations. + +Are we going to +try to figure out + +how the total pressure +above the solution changes. + +That's maybe the +goal of the problem. + +When you change this +to, eventually we'll + +change it to 0.95 +and 0.05, and we'll + +want to know how does that +change the total pressure. + +So immediately we see +that this is a solvent. + +This is a solute. + +This is volatile. + +So, we're close to +where this is zero. + +So if we're going to apply any, +sort of, Raoult or Henry's law + +problem to this, +this is probably + +going to be Henry's law for +B and Raoult's law for A. + +We're going to be close +to this area here for B. + +We're going to be close +to this area for A. + +OK. + +So ah the first +question is, what's + +the composition +in the gas phase. + +What is y sub B. And it looks +like this particular set + +of notes doesn't have +the calculations. + +I'm going to go to my other set +of notes here that has them. + +So, because I'm going +to make a mistake if I + +go through it +without my notes, I'm + +going to leave it up +to you to do part a. + +That's a good way +out of making a mess. + +I'm just going to +tell you the answer. + +Because the actual, +the interesting part, + +is part b of the problem. + +Part a is the easy part. + +So this is something that +you can do on your own. + +So yB is equal to 0.139. + +Is going to be answer to +part b, given these two molar + +fractions and the +total pressure. + +So now, what we're +going to do is, + +we're going to change +the molar fractions + +and we're going to +find out how that + +changes the total pressure. + +So, second part is we're +still at 50 degrees Celsius. + +And we're going to change the +molar fraction of A to 0.95. + +And the molar +fraction of B to 0.05. + +And we're going to ask, +what is p total now. + +So we write what we know. + +Which is that we +expect p total to be + +the sum of the partial pressures +of A and B. A is the solvent, + +B is the solute. + +It's a dilute +non-ideal solution. pA + +is going to be proportional +to Raoult's law, + +because it's a solvent. + +It's in large quantities. + +So it's going to be xA pA star. + +And xB is going, and +pB is going to be + +proportional to the +mole fraction again. + +But because it's a solute, it's +seen most the other molecules + +of A around, it's +not necessarily + +going to be obeying +Raoult's law. + +It's going to obey Henry's law. + +It's going to be close +to the zero point. + +There's going to be a deviation +because of the interactions + +between A and B. +Which dominate now. + +So instead of pA +star, we have KB here, + +where this is the +Henry's law constant. + +Which depends on the +fact that A is around. + +We get a different constant +if we have a different solvent + +around. + +So we know this. + +We know this because that was +given to us at the beginning. + +But we don't know this here. + +We don't know what the +Henry's law constant here is. + +But we can get it. + +We can get it from part a here. + +Because we have all the +information we need there. + +So from part a, we +already have a mixture + +where we're given +the total pressure. + +So from part a, +KB is pB over xB. + +And we calculated +what yB is over there. + +On part a. + +So we know what the +partial pressure of B is. + +It's the molar fraction +of B in the gas + +phase times the total pressure. + +That's Dalton's law. + +Then we divide by xB. + +And then we plug in +the number 0.139 times + +the total pressure +up there is 0.7. + +Divided by 0.1. + +And we get that +this is 0.973 bar. + +So now we can plug this +in to our equation here. + +We know xA, we know xB, we know +Raoult's law, the 0.67 pA star. + +We know KB here. + +We plug in all the +numbers, and we + +get that the total +pressure is now 0.685 bar. + +This is a pretty typical +example of a problem that + +combines Raoult's law, Henry's +law and Dalton's law together. + +And keeping track of these laws +takes a little bit of thinking. + +And it's very, very common +on problem sets or exams + +to mix these up. + +So it's good to go +through examples like this + +and really keep track of +where each law applies. + +Dalton's law applies +in the gas phase. + +It's partial pressure +in the gas phase. + +Henry's law is the pressure. + +If you know what's happening in +the liquid phase, for a solute. + +Raoult's law is the partial +pressure in the gas phase, + +if you know what's happening +in the liquid phase. + +So Raoult and Henry tell you +something about the pressure + +if you know the liquid. + +Dalton only deals with what's +happening in the gas phase. + +OK, any questions +on the problem? + +Alright. + +So we did this problem +here, and now let's + +draw the phase diagram for our +solute here, or for B, rather. + +Zero to one. + +And let's take a vote here. + +So if Raoult's law worked for +B, for the mixture of A and B, + +then we would have pB star here. + +And everything would be great. + +But Raoult's law doesn't work. + +Close to molar fraction of zero. + +Instead, Henry's law. + +There's a deviation, +due to the interactions + +between the molecules +A and B here. + +So we have two choices +for the deviation. + +We can have a +positive deviation, + +or we could have a +negative deviation. + +Positive deviation, +if the molecules of B + +would rather be +in the gas phase, + +than be in the mixture +in the liquid phase. + +Meaning they don't +like molecules of A. + +They don't like to be +mixed with molecules + +of A. The energy of +interaction is not favorable. + +The enthalpy is not +favorable, for mixing + +A and B. In this case +here, the enthalpy + +is favorable for mixing A and B. + +So in this problem here, +which do you think it is? + +The blue one or the green one. + +Let's raise hands here. + +How many people think +it's the blue one here. + +Anybody else? + +The right answer, +we have four people. + +How many people think +it's the green one? + +Four. + +Five. + +Six. + +You didn't vote twice, did you? + +Vote early, vote often, right? + +Mayor Daley, the old +Mayor Daley in Chicago. + +And if you know somebody +who's dead, vote for them. + +OK, so this is the, I've +got about five people here. + +And a bunch of +people didn't vote. + +So it's a tie. + +It's basically a tie here. + +I think you should +think about this. + +Maybe talk to each +other a little bit. + +See if you can figure +out, given all the numbers + +that are in this +problem here, you + +know what, the pure +pressure on the solvent is. + +We change concentrations here. + +Got Henry's law constant out. + +And Henry's law +constant is going + +to tell you whether or not +that enthalpy of interaction + +is favorable or not favorable. + +It's going to be a +positive deviation + +or a negative deviation. + +OK, shall we vote again. + +How many people say +it's the blue one? + +How many people say +it's the green one. + +Thank you. + +Alright. + +Good. + +Alright. + +We have K sub B is +less than p star, + +therefore it's a +negative deviation. + +The pressure is less +than you'd expect. + +The molecules like each +other better than you expect. + +There is a favorable enthalpy +of interaction between A and B. + +They like to interact. + +It could be hydrogen bonding. + +Could be a lot of +different things. + +OK, so now if I put the +whole diagram together, + +which I shouldn't +have erased here. + +Right, so there's my +diagram here again. + +There's Raoult's law. + +There's the deviation +from Raoult's law here. + +For one substance, +let's say for B. There's + +Raoult's law for A. There's +a deviation for A. It + +could be like this. + +And if I now add +these two together, + +instead of having +a diagram for, this + +is a pressure xB, yB diagram, +pressure xB, yB diagram, + +instead of having Raoult's +law sitting right here. + +And then the yB part down +here below, your usual sort + +of ideal solution phase +diagram with the high pressure + +of the liquid on top and +the gas on the bottom. + +Now if you add the blue curve +and the red curve together, + +you're not going to +get a straight line + +like you did before. + +When Raoult's law +applied throughout. + +Instead you're going +to get a deviation + +from the straight line. + +You're going to +get a curve that's + +always below the straight line. + +Because we have the negative +deviation on both sides. + +So you end up with +something that's + +curved and deviates below. + +And the same thing will +happen for the bubble line. + +It will also deviate below. + +In some way. + +Maybe not as much, maybe. + +So this is what you usually see. + +You see deviation of +that whole phase diagram, + +like you're pushing down on it. + +Or maybe it didn't pulled up. + +If you have a +positive deviation, + +then it's the opposite. + +It gets, this is +negative deviation. + +And if you have a +positive deviation, + +instead of having a +usual phase diagram, + +you're going to get something +that's looking like this. + +Which is the Henry's +law coming in. + +Yes. + +STUDENT: [INAUDIBLE] + +PROFESSOR: Yes. + +STUDENT: [INAUDIBLE] + +PROFESSOR: Doesn't matter. + +Good question, though. + +OK, so this is what +it usually looks like. + +And everything +you've learned so far + +can be applied to +these diagrams here. + +There's one exception, though, +which is an important one. + +Which is, sometimes, +these non-ideal diagrams + +have a funny spot. + +Which is that if I +draw them, so there's + +my xB, yB, on the bottom. + +Zero to one. + +I have pressure here. + +Sometimes, there's the dew line. + +And the bubble line. + +Sometimes, instead of +having a nice separation + +between the bubble +and the dew line, + +there's a special point +which for some reason + +those two curves meet. + +Non-ideality. + +There's interaction +between the molecules. + +In the gas phase and +the liquid phase. + +This special point is +an interesting one. + +Because, well, if I'm away +from this special point, + +let's say I'm sitting to the +left of the special point, + +right here. + +And I can distill this thing. + +I can take my gas phase here. + +And increase the pressure. + +Say I'm sitting here in +the mixture, gas phase + +mixture with x prime B, y +prime B. Sorry, x prime B. + +And I go up and I +increase the pressure. + +Start making vapor. + +Start making vapor, I +can find out what the, + +I start making liquid. + +I can find out where the +composition in the liquid + +is by going over to +the blue line here. + +That tells me the +composition in the liquid. + +And reading off the composition +of the liquid down here. + +So this is actually the +composition in the gas phase + +is yB prime. yB prime +is the gas phase. + +I'm starting here. + +I start to increase +the pressure. + +I begin the +distillation process. + +And I get a little +bit of liquid out. + +And I can read off the +composition in the liquid. xB + +prime. + +And I know from this diagram +that xB prime is less then + +yB prime. + +So I'm enriching +my liquid in A. I'm + +purifying my +solution in A, right? + +I can get pure A out eventually. + +The fact of doing +this, I can get pure A. + +So I decrease the pressure, +I get the pure gas phase + +of my new solution here. + +And I increase the pressure. + +And go over and make a +little bit of liquid. + +And capture that liquid. + +And repeat the process +over and over again. + +And eventually I have pure A. + +Now, suppose I'm sitting +here at this special point. + +And I'm starting with yB And +let me call it a here. yB of a. + +I'm sitting right here. + +And I'm increasing the pressure. + +I go all the way up here. + +And I start making liquid. . + +What's the composition +of liquid, compared + +to the composition +of the gas phase? + +What's y? + +What's xB compared to yB +of this point up here? + +It's the same. + +So I'm making liquid. + +I got the same composition. + +Doesn't help me. + +If I make a gas again, I still +have the same composition. + +I can't distill. + +I can't purify it. + +So if I have this special +mixture here, of A and B, + +at this point here, I form +what's called an azeotrope. + +And then you can't +separate it out. + +You can't separate out +the mixtures into A and B. + +You can't distill it +at that point here. + +Now, you can draw the same +diagram in, instead of + +pressure, mole fraction, you +can draw the same diagram + +in terms of temperature. + +And the same thing happens. + +You can have +deviations from, this + +is the extra figures that +are on the bottom page + +of the notes from +last time here. + +That we've replaced here. + +You can have a +positive deviation. + +With a positive azeotrope. + +And your T p +diagram, T x diagram. + +Or you can have, depending +on the interactions + +between the two +molecules, you can + +have something that has +a negative deviation. + +And a negative azeotrope here. + +So in this case here, this is +a particularly awful situation. + +Because there's your +liquid phase down here. + +There's the gas phase here. + +And now, suppose +that you're doing + +some sort of distillation. + +So you start here in the liquid +phase, with some composition. + +You make a gas. + +Let's say you're doing a +fractional distillation + +of some sort. + +Your gas now has a new mixture. + +So this is the composition +in the gas phase. + +You take that gas phase +mixture, and you condense it + +in your condenser. + +In your fractional +distillation condenser. + +So now I've condensed it. + +And I heat it up again. + +I've condensed it. + +So I'm here somewhere. + +And cool it down so +that I have a liquid. + +And I condense it. + +And slowly I move over +to the azeotrope point. + +And once I get there, I'm stuck. + +And the same thing happens +if I'm on the other side. + +I'm on this point here, I +keep my solution, my mixture. + +I make a gas, I read off the +composition of the gas phase + +here. + +I take my gas phase composition +out and I re-liquefy it. + +So I'm here, down +here somewhere, again. + +And I heat it up again. + +And and I move to +the azeotrope point. + +That's what happens if you have +a mixture of benzene and water, + +for instance. + +You can't distill it. + +You work your way down +to this point here. + +You can't use +fractional distillation + +until you've separated it out. + +So this is a real life problem. + +And you have to do things +like change the pressure. + +Do your distillation under +high pressure or low pressure. + +To try to get this +point to separate out. + +So you can get past this point. + +Or to try to get the deviation +to become of the opposite sign. + +Where you can start to +do some distillation. + +Any questions on +azeotropes, before we + +get to colligative properties? + +If you're doing +organic chemistry, + +and you're trying +to purify things, + +this is a real pain, right? + +Pain in the neck. + +So you've got to know, which +things form azeotropes. + +So we're going to start +colligative properties. + +There are four +colligative properties, + +and you already +know what they are. + +And you've even seen +the math behind them. + +And in fact, you've seen +the math for one of them + +already pretty clearly. + +And these colligative +properties are + +properties that you use all the +time in your day to day life. + +At least, three of them. + +OK what are the four +colligative properties? + +There is vapor +pressure lowering. + +If you have a mixture and the +vapor pressure of the mixture + +is less than the vapor +pressure of the pure material, + +there's the boiling +point elevation. + +If you add a large amount of +insoluble - not insoluble, + +non-volatile solute to a +solution, you will depress, + +you will increase the boiling +point of that solution like + +the example of the salt +and water that I gave. + +So if you need a lot +of salt to increase + +the boiling point of water. + +There's the freezing +point depression. + +That's what we use to +melt ice in the winter. + +By adding salt to it. + +Then there's the +osmotic pressure. + +Which is the example of the +freshwater fish in salt water, + +or the saltwater +fish in fresh water. + +Or the cells bursting +when you put them in. + +OK, so these colligative +properties all come + +from the fact if +I have a mixture, + +the chemical potential of +a molecule in a mixture, + +in the liquid +phase here, is less + +than the chemical +potential of the pure guy. + +Where A is the solvent, +and B is some solute. + +So this is always true if +your number of moles of A + +is much larger than +number of moles of B. Mix + +a little bit of B in there, +and the chemical potential of A + +in the liquid is +going to come down. + +Because of the mixing process. + +Because of the +entropy of mixing. + +And that's going to give +rise to these properties. + +And, to do these, one more +thing before we start. + +We're going to use a special +concentration for these guys. + +We're going to use, +call something molality. + +Molality. + +Molality is the number +of moles of solute + +divided by kilograms of solvent. + +So it's moles per +weight of solvent. + +As opposed to moles +per liter, which + +is something that +we're more used to. + +Moles per kilograms of solvent. + +It's pretty close to +moles for liter for water. + +Because a gram of water +is a milliliter, roughly. + +The density of +water's close to one. + +So let's start on these things. + +So we've already seen this. + +You've already seen +vapor pressure lowering. + +It comes from Raoult's law. + +If I look at the change in +the vapor pressure of A, pA + +minus pA star. pA is equal to +xA pA star. xA pA star, that's + +Raoult's law. + +Minus pA star, that's +equal to one minus xA. + +Minus pA star. + +Which is minus xB pA star. + +Which is less than zero. + +So, that means that the vapor +pressure above the solution + +is lowered. + +So I should have said +vapor pressure lowering. + +And we also drew a +phase diagram to show + +how this vapor +pressure lowering was + +going to imply freezing point +depression and boiling point + +depression. + +So now let's go on and look at +the freezing point depression. + +Number two. + +We're going to find that the +change in the boiling point + +is going to be some constant +K sub b, which is not + +to be confused with +Henry's law's constant. + +It's completely different. + +This is a colligative property. + +Times the molality +of B. That's going + +to be the answer +we're going to get. + +Amount of temperature +change depends linearly + +on the molality of +B, with a constant + +that depends on +what the mixture is. + +And what the pressure is. + +Whenever we derive anything +connected to phase transitions, + +we usually always +start with the fact + +that the chemical +potential changes. + +And it has to be +equal at equilibrium. + +So that's what +we're going to do. + +We're going to start with +the chemical potential equal + +of the liquid phase is equal +to the chemical potential + +of the gas phase. + +For the solvent at equilibrium. + +And the liquid phase +obeys Raoult's law. + +So it's going to be the chemical +potential of the pure material. + +The pure liquid. + +Plus RT log xA. + +So this is where the mixing +of the solute comes in. + +And on the gas phase +side, mu A, it's + +going to be the same thing +as the chemical potential + +of the pure A. +Because we're going + +to take B to be non-volatile. + +So the only thing +in the gas phase + +is A. Same chemical +potential as if it were pure. + +Because it is pure. + +So now we solve for log xA +is equal to one over RT mu + +A star in the gas phase minus +mu A star in the liquid phase. + +And this is just the +Gibbs free energy + +per mole of A in the gas phase. + +The Gibbs free energy per +mole of A in the liquid phase. + +So we can replace this with +the change in Gibbs free energy + +from going from gas to liquid. + +Per mole, which +is just the Gibbs + +free energy of vaporization. + +We're going from liquid to gas. + +And I probably have a +negative sign somewhere. + +No this is right, this +is the final state. + +This is the initial state. + +Divided by RT. + +OK. + +That's not really +what we want, though. + +What we want is +delta T. Here I've + +got some complicated +equation that has T in it, + +but not delta T. +But before we do + +that, before we transfer +and try to get a delta T out + +of this equation, +let's see if we + +can do any sort of +simplifications here. + +I don't like to +carry logs around. + +There are no logs around here. + +So let's see if we can +get rid of that log. + +What is log xA? + +Log xA, well, xA +is close to one. + +It's connected to xB. + +And everything in +here is connected + +to B. There's a +molality of B here. + +The concentration of A +doesn't come into play here. + +I don't want it there. + +So let me replace it with B. one +minus xB. xB is a small number. + +It's a solute, it's +in small amount. + +We're close to being +a pure solvent here. + +So one minus +something very small. + +The log of that. + +Well if you've worked +with Taylor's expansions. + +You probably know that +that's close to minus xB. + +The log of one minus +x where x goes to zero + +is close to minus x. + +So that's minus xB. + +Now, minus xB, in +terms of the moles, + +is the number of moles of B +divided by the number of moles + +of B plus the number of moles +of A, the total number of moles. + +The number of moles +of B is very small, + +compared to the number of moles +of A. So I can get rid of this. + +So, and there's a +minus sign here. + +So this is approximately +minus nB divided by nA. + +Now, the only I can do is, I'm +trying to get at molality here. + +I said we're going +to use molality. + +Got moles. + +I don't have kilograms +of solvent here. + +I have moles of solvent. + +I'm not so happy with that. + +So, in order to get something +that has kilograms out, + +let's multiply up and down by +capital M where capital M is + +that total mass of A. Basically +the number of kilograms + +of solvent. + +Total mass of A. So +now, this fraction here, + +that's the molality. + +That's what I'm looking for. + +So this is minus the molality. + +Then I have the total +mass of A divided + +by the number of moles +of A. Well, that's + +the molecular weight of it. + +Total mass divided by +the number of moles + +is the molecular weight. + +So this is the molality of +B times the molecular weight + +of A. OK. + +So now I can plug this +instead of log xA. + +And I get minus nB times +nA is equal to delta + +G of vaporization divided by RT. + +Let's rearrange a little bit. + +And mB is equal to to delta +G vaporization divided + +by nA times RT, with +a negative sign. + +Well, I've eliminated +the log at least, + +but I still don't have +a delta T in there. + +I don't have a delta +T. How am I going + +to get a delta T in there? + +Got to get the delta T. +Everything's very small. + +So one way to get a small +change in temperature + +is to take a derivative +with respect to temperature. + +That's going to get +a delta T in there. + +So I'm going to take the +derivative of both sides + +with respect to T. + +And delta T is going +to come out that. + +I'm going to take d nB +/ dT, constant pressure. + +Minus one over mA times +R d delta G over T. This + +is delta G of vaporization. +dT, constant pressure. + +And I wish I'd made my +boards a little bit better. + +Because I have to +cover things up. + +OK, now I have this derivative +of the Gibbs free energy + +divided by the temperature. + +This turns out to be something +that you've seen before. + +It's called the +Gibbs-Helmholtz equation. + +And it relates the temperature +change in the Gibbs free energy + +with the enthalpy change. + +The Gibbs-Helmholtz equation +is that the d delta G over T dT + +is equal to minus +delta H over T. + +And you can get that from just +writing fundamental equations + +about G and H. And +turning the crank. + +And we've done that before. + +And I'll leave that +as an exercise for you + +to go back and figure +out what, you can go back + +to your textbook and look +at, you know under the index. + +Gibbs-Helmholtz, and figure +out why this is the case. + +So now, we have +this equation here. + +This is going to be +nice, because it's + +going to get rid of the d/dT. + +On the right-hand side. + +And so now our +equation becomes d + +mB / dT is equal to delta H +vaporization divided by mA R T + +squared. + +Now, I can rewrite this in +a slightly different way. + +This is delta m over +delta T, basically. + +Delta the change +in number of moles. + +I mean, the molality +of B divided + +by the change in temperature. + +I'm getting very close here. + +There's a change in +temperature here. + +There's a change +in molality here. + +I can rewrite this +as delta T, then, + +is equal to molecular +weight of A times + +RT squared divided by delta H +vaporization times delta mB. + +Now, I'm making a very +small change in B here. + +Starting at zero. + +Basically I'm taking +pure A and I'm + +dumping in a little +bit of B. That's + +what I'm doing +when I experiment. + +I'm dumping in a little +bit of B in my pure A, + +and I'm trying to figure out +how the temperature is changing. + +So I'm doing delta m sub +B is my small amount of B + +that I'm adding to the solution. + +Minus what I started out +with, which was zero. + +So delta mB is basically +m sub B. Right? + +That's basically what it is. + +So let's get rid +of this delta here. + +What else can I say? + +Well, I can say that the +temperature change that I'm + +looking at is also pretty small. + +Compared to the +absolute temperature. + +This is a small change. + +I'm only adding a small +amount of B in there. + +So this temperature up here is +not going to change very much. + +Let's take it to +be the temperature + +of the boiling point +of the pure material. + +T sub B star, of +the pure material. + +OK And there's my delta T here. + +So this is of the +form delta T is + +equal to molecular weight +of A. Times R. Times + +the boiling point of the +pure material squared. + +Divided by delta +H of vaporization + +of the pure solvent. + +Times the molality of B. And +this combination of properties + +of A, the molecular weight of +A, the boiling point of pure A. + +The heat of vaporization of +pure A, this is K sub b up here. + +Which I covered up. + +It's of the form delta T is +equal to K sub b times mB. + +And this turns out to be +always greater than zero. + +Now. + +If you want to look at +freezing point depression, + +it's really easy. + +In your equations, it's the +same thermodynamic picture. + +All you need to do, +in all your equations, + +you replace delta +G of vaporization + +with minus delta G of freezing. + +When we did a vaporization, +we're going from liquid to gas. + +We had delta G of vaporization. + +When we're doing freezing +point depression, + +we're going from +liquid to solid. + +And so we have to use +minus delta G of fusion. + +Minus delta H of +fusion. s to l would + +be the positive +delta G of fusion. + +So we're going from +liquid to solid. + +We have to replace +delta G of vaporization + +with delta G of fusion. + +We replace delta +H of vaporization, + +where minus delta H of fusion. + +Replace the boiling point +with the freezing point. + +And replace K sub +b with K sub f. + +And the math is +exactly identical. + +It all starts from the chemical +potentials being equal. + +And turning the crank +at equilibrium, being + +equal between the solid +phase and the liquid phase. + +And turning the crank. + +The solid phase is +like the gas phase. + +It's a pure A, pretty much. + +Because the molecules +of B are stuck. + +And A doesn't know that B's +around, in the solid phase. + +They know that they're +around in the liquid phase + +because the fusion +fast enough. . + +And then we can write, +if we turn the crank, + +we get an equation +that looks like this. + +The freezing point depression +is equal to minus mA + +R Tf star squared. + +Divided by delta H +of fusion, for mole. + +Times the molality +of B. And this number + +is always less than zero. + +There's the negative +signs in here. + +OK. + +Always depressed. + +Any questions about those +freezing point depression + +and boiling point elevation. + +Yes. + +STUDENT: [INAUDIBLE] PROFESSOR: +Why did I drop it here? + +Because the small change +that I'm making in nB + +is going from pure +A, where nB is zero, + +to a very small amount of nB. + +That's why I'm +allowed to say this. + +And then just replace +delta nB with nB. + +I'm comparing every, +my reference point + +is the pure material. + +I'm just adding a little +bit to start with. + +It's a good question. + +Any other questions? + +OK. + +I didn't get to +osmotic pressure. + +You'll get to that on Friday. + +And also start +statistical mechanics. + +And after osmotic pressure, +you'll be done with thermo. + +It'll be statistical +mechanics and then kinetics. \ No newline at end of file diff --git a/wrEcHhoJxjM.txt b/wrEcHhoJxjM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c129b82f52acaee519e9c3cbb821840b54ea8dce --- /dev/null +++ b/wrEcHhoJxjM.txt @@ -0,0 +1,5867 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +talk about gradient descent and the and + + align:start position:0% +talk about gradient descent and the and + + + align:start position:0% +talk about gradient descent and the and +its descendants so from the basic + + align:start position:0% +its descendants so from the basic + + + align:start position:0% +its descendants so from the basic +gradient descent formula which we all + + align:start position:0% +gradient descent formula which we all + + + align:start position:0% +gradient descent formula which we all +know let me just write that down the new + + align:start position:0% +know let me just write that down the new + + + align:start position:0% +know let me just write that down the new +point is the old point we're going + + align:start position:0% +point is the old point we're going + + + align:start position:0% +point is the old point we're going +downwards so with a minus sign that's + + align:start position:0% +downwards so with a minus sign that's + + + align:start position:0% +downwards so with a minus sign that's +the step size and we compute the + + align:start position:0% +the step size and we compute the + + + align:start position:0% +the step size and we compute the +gradient at X K so we're descending in + + align:start position:0% +gradient at X K so we're descending in + + + align:start position:0% +gradient at X K so we're descending in +the direction of the negative gradient + + align:start position:0% +the direction of the negative gradient + + + align:start position:0% +the direction of the negative gradient +and that's the basic formula and is in + + align:start position:0% +and that's the basic formula and is in + + + align:start position:0% +and that's the basic formula and is in +every book studied so my main reference + + align:start position:0% +every book studied so my main reference + + + align:start position:0% +every book studied so my main reference +for the some of these lectures is the + + align:start position:0% +for the some of these lectures is the + + + align:start position:0% +for the some of these lectures is the +book by Stephen Boyd and Linden and + + align:start position:0% +book by Stephen Boyd and Linden and + + + align:start position:0% +book by Stephen Boyd and Linden and +Vandenberg and and I mentioned again + + align:start position:0% +Vandenberg and and I mentioned again + + + align:start position:0% +Vandenberg and and I mentioned again +professor Boyd is talking in this room + + align:start position:0% +professor Boyd is talking in this room + + + align:start position:0% +professor Boyd is talking in this room +next week Wednesday Thursday and and + + align:start position:0% +next week Wednesday Thursday and and + + + align:start position:0% +next week Wednesday Thursday and and +he's speaking somewhere on Friday at + + align:start position:0% +he's speaking somewhere on Friday at + + + align:start position:0% +he's speaking somewhere on Friday at +4:30 and of course about optimization + + align:start position:0% +4:30 and of course about optimization + + + align:start position:0% +4:30 and of course about optimization +and he's a good lecturer yeah very good + + align:start position:0% +and he's a good lecturer yeah very good + + + align:start position:0% +and he's a good lecturer yeah very good +okay so there's steepest descent and + + align:start position:0% +okay so there's steepest descent and + + + align:start position:0% +okay so there's steepest descent and +I've redrawn my picture from last time + + align:start position:0% +I've redrawn my picture from last time + + + align:start position:0% +I've redrawn my picture from last time +that I'll go over there and look at that + + align:start position:0% +that I'll go over there and look at that + + + align:start position:0% +that I'll go over there and look at that +picture but let me say what's coming so + + align:start position:0% +picture but let me say what's coming so + + + align:start position:0% +picture but let me say what's coming so +that's pretty standard very standard you + + align:start position:0% +that's pretty standard very standard you + + + align:start position:0% +that's pretty standard very standard you +could say then this is the improvement + + align:start position:0% +could say then this is the improvement + + + align:start position:0% +could say then this is the improvement +that is widely used adding in something + + align:start position:0% +that is widely used adding in something + + + align:start position:0% +that is widely used adding in something +called momentum to avoid the zigzag that + + align:start position:0% +called momentum to avoid the zigzag that + + + align:start position:0% +called momentum to avoid the zigzag that +we're going to see + + align:start position:0% +we're going to see + + + align:start position:0% +we're going to see +and there's another way to do it there's + + align:start position:0% +and there's another way to do it there's + + + align:start position:0% +and there's another way to do it there's +a Russian guy named Nestor off his + + align:start position:0% +a Russian guy named Nestor off his + + + align:start position:0% +a Russian guy named Nestor off his +papers are not easy to read but they've + + align:start position:0% +papers are not easy to read but they've + + + align:start position:0% +papers are not easy to read but they've +got serious content and one thing he did + + align:start position:0% +got serious content and one thing he did + + + align:start position:0% +got serious content and one thing he did +was find an alternative to momentum that + + align:start position:0% +was find an alternative to momentum that + + + align:start position:0% +was find an alternative to momentum that +also accelerated the the descent so this + + align:start position:0% +also accelerated the the descent so this + + + align:start position:0% +also accelerated the the descent so this +produces these both produce faster + + align:start position:0% +produces these both produce faster + + + align:start position:0% +produces these both produce faster +descent than the ordinary one okay and + + align:start position:0% +descent than the ordinary one okay and + + + align:start position:0% +descent than the ordinary one okay and +then you know looking ahead that for + + align:start position:0% +then you know looking ahead that for + + + align:start position:0% +then you know looking ahead that for +problems of machine learning they're so + + align:start position:0% +problems of machine learning they're so + + + align:start position:0% +problems of machine learning they're so +large that the gradient and we have so + + align:start position:0% +large that the gradient and we have so + + + align:start position:0% +large that the gradient and we have so +many variables all those weights are + + align:start position:0% +many variables all those weights are + + + align:start position:0% +many variables all those weights are +variables all and that could hundreds of + + align:start position:0% +variables all and that could hundreds of + + + align:start position:0% +variables all and that could hundreds of +thousands is is not uncommon + + align:start position:0% +thousands is is not uncommon + + + align:start position:0% +thousands is is not uncommon +so that then the gradient becomes a + + align:start position:0% +so that then the gradient becomes a + + + align:start position:0% +so that then the gradient becomes a +pretty big calculation and we don't have + + align:start position:0% +pretty big calculation and we don't have + + + align:start position:0% +pretty big calculation and we don't have +to do it all at once we don't have to + + align:start position:0% +to do it all at once we don't have to + + + align:start position:0% +to do it all at once we don't have to +change so xk is a vector of all the + + align:start position:0% +change so xk is a vector of all the + + + align:start position:0% +change so xk is a vector of all the +weights or and using and our equations + + align:start position:0% +weights or and using and our equations + + + align:start position:0% +weights or and using and our equations +are the matching the the training data + + align:start position:0% +are the matching the the training data + + + align:start position:0% +are the matching the the training data +so we don't have to use all the training + + align:start position:0% +so we don't have to use all the training + + + align:start position:0% +so we don't have to use all the training +data at once and we don't we take a + + align:start position:0% +data at once and we don't we take a + + + align:start position:0% +data at once and we don't we take a +batch of training data like one but + + align:start position:0% +batch of training data like one but + + + align:start position:0% +batch of training data like one but +that's sort of inefficient in the + + align:start position:0% +that's sort of inefficient in the + + + align:start position:0% +that's sort of inefficient in the +opposite direction they do them one at a + + align:start position:0% +opposite direction they do them one at a + + + align:start position:0% +opposite direction they do them one at a +time so we don't want to do with them + + align:start position:0% +time so we don't want to do with them + + + align:start position:0% +time so we don't want to do with them +one at a time but we don't want to do + + align:start position:0% +one at a time but we don't want to do + + + align:start position:0% +one at a time but we don't want to do +all all million at a time + + align:start position:0% +all all million at a time + + + align:start position:0% +all all million at a time +so the compromise is a mini batch so + + align:start position:0% +so the compromise is a mini batch so + + + align:start position:0% +so the compromise is a mini batch so +sarcastic gradient descent does a mini + + align:start position:0% +sarcastic gradient descent does a mini + + + align:start position:0% +sarcastic gradient descent does a mini +batch at a time a mini batch of of + + align:start position:0% +batch at a time a mini batch of of + + + align:start position:0% +batch at a time a mini batch of of +training of samples training data each + + align:start position:0% +training of samples training data each + + + align:start position:0% +training of samples training data each +step and it can choose them + + align:start position:0% +step and it can choose them + + + align:start position:0% +step and it can choose them +stochastically meaning randomly or + + align:start position:0% +stochastically meaning randomly or + + + align:start position:0% +stochastically meaning randomly or +sitting more systematically but we do a + + align:start position:0% +sitting more systematically but we do a + + + align:start position:0% +sitting more systematically but we do a +batch at a time and that will come after + + align:start position:0% +batch at a time and that will come after + + + align:start position:0% +batch at a time and that will come after +the + + align:start position:0% +the + + + align:start position:0% +the +it'll come next week after a marathon of + + align:start position:0% +it'll come next week after a marathon of + + + align:start position:0% +it'll come next week after a marathon of +course on Monday okay so let me just go + + align:start position:0% +course on Monday okay so let me just go + + + align:start position:0% +course on Monday okay so let me just go +back to that picture for a moment but + + align:start position:0% +back to that picture for a moment but + + + align:start position:0% +back to that picture for a moment but +then the real content of today is this + + align:start position:0% +then the real content of today is this + + + align:start position:0% +then the real content of today is this +one with momentum added okay I just I + + align:start position:0% +one with momentum added okay I just I + + + align:start position:0% +one with momentum added okay I just I +probably haven't got the picture perfect + + align:start position:0% +probably haven't got the picture perfect + + + align:start position:0% +probably haven't got the picture perfect +yet I'm just not an artist but I think + + align:start position:0% +yet I'm just not an artist but I think + + + align:start position:0% +yet I'm just not an artist but I think +I'm closer so this is uh those are the + + align:start position:0% +I'm closer so this is uh those are the + + + align:start position:0% +I'm closer so this is uh those are the +level sets those are the sets f of X + + align:start position:0% +level sets those are the sets f of X + + + align:start position:0% +level sets those are the sets f of X +equal constant and in our model problem + + align:start position:0% +equal constant and in our model problem + + + align:start position:0% +equal constant and in our model problem +f of X is X 1 squared or let's say x + + align:start position:0% +f of X is X 1 squared or let's say x + + + align:start position:0% +f of X is X 1 squared or let's say x +squared plus B y squared equal constants + + align:start position:0% +squared plus B y squared equal constants + + + align:start position:0% +squared plus B y squared equal constants +with small B be below 1 and maybe far + + align:start position:0% +with small B be below 1 and maybe far + + + align:start position:0% +with small B be below 1 and maybe far +below 1 so those are ellipses those the + + align:start position:0% +below 1 so those are ellipses those the + + + align:start position:0% +below 1 so those are ellipses those the +equations of an ellipse and that's what + + align:start position:0% +equations of an ellipse and that's what + + + align:start position:0% +equations of an ellipse and that's what +I tried to draw and if B is small then + + align:start position:0% +I tried to draw and if B is small then + + + align:start position:0% +I tried to draw and if B is small then +the ellipses are long and thin like that + + align:start position:0% +the ellipses are long and thin like that + + + align:start position:0% +the ellipses are long and thin like that +and now what's what's the picture you + + align:start position:0% +and now what's what's the picture you + + + align:start position:0% +and now what's what's the picture you +start with a point X naught and you + + align:start position:0% +start with a point X naught and you + + + align:start position:0% +start with a point X naught and you +descend in the steepest direction so the + + align:start position:0% +descend in the steepest direction so the + + + align:start position:0% +descend in the steepest direction so the +steepest direction is perpendicular to + + align:start position:0% +steepest direction is perpendicular to + + + align:start position:0% +steepest direction is perpendicular to +the level set right perpendicular to the + + align:start position:0% +the level set right perpendicular to the + + + align:start position:0% +the level set right perpendicular to the +ellipse so you down down down you're + + align:start position:0% +ellipse so you down down down you're + + + align:start position:0% +ellipse so you down down down you're +passing through more ellipses more + + align:start position:0% +passing through more ellipses more + + + align:start position:0% +passing through more ellipses more +ellipses more ellipses eventually your + + align:start position:0% +ellipses more ellipses eventually your + + + align:start position:0% +ellipses more ellipses eventually your +tangent to it seems to me it has to be + + align:start position:0% +tangent to it seems to me it has to be + + + align:start position:0% +tangent to it seems to me it has to be +tangent I didn't read this but it looks + + align:start position:0% +tangent I didn't read this but it looks + + + align:start position:0% +tangent I didn't read this but it looks +reasonable to me that the the farthest + + align:start position:0% +reasonable to me that the the farthest + + + align:start position:0% +reasonable to me that the the farthest +in level-set farthest an ellipse you're + + align:start position:0% +in level-set farthest an ellipse you're + + + align:start position:0% +in level-set farthest an ellipse you're +tangent to and then you start going up + + align:start position:0% +tangent to and then you start going up + + + align:start position:0% +tangent to and then you start going up +again so that's the optimal point to + + align:start position:0% +again so that's the optimal point to + + + align:start position:0% +again so that's the optimal point to +stop to end that step and then where + + align:start position:0% +stop to end that step and then where + + + align:start position:0% +stop to end that step and then where +does the next step go well you're here + + align:start position:0% +does the next step go well you're here + + + align:start position:0% +does the next step go well you're here +you're on an ellipse that's a level set + + align:start position:0% +you're on an ellipse that's a level set + + + align:start position:0% +you're on an ellipse that's a level set +you want to move in the gradient + + align:start position:0% +you want to move in the gradient + + + align:start position:0% +you want to move in the gradient +direction that's perpendicular to the + + align:start position:0% +direction that's perpendicular to the + + + align:start position:0% +direction that's perpendicular to the +level set so you're going down somewhere + + align:start position:0% +level set so you're going down somewhere + + + align:start position:0% +level set so you're going down somewhere +here and you're passing again through + + align:start position:0% +here and you're passing again through + + + align:start position:0% +here and you're passing again through +more and more ellipses until your + + align:start position:0% +more and more ellipses until your + + + align:start position:0% +more and more ellipses until your +tangent to a + + align:start position:0% +tangent to a + + + align:start position:0% +tangent to a +to a smaller ellipse here and and you + + align:start position:0% +to a smaller ellipse here and and you + + + align:start position:0% +to a smaller ellipse here and and you +see the zig-zag pattern and that zig-zag + + align:start position:0% +see the zig-zag pattern and that zig-zag + + + align:start position:0% +see the zig-zag pattern and that zig-zag +pattern is what we see by formula in in + + align:start position:0% +pattern is what we see by formula in in + + + align:start position:0% +pattern is what we see by formula in in +Boyd's book and many other places too + + align:start position:0% +Boyd's book and many other places too + + + align:start position:0% +Boyd's book and many other places too +the formula has the there was powers of + + align:start position:0% +the formula has the there was powers of + + + align:start position:0% +the formula has the there was powers of +a beam of the magic number so we start + + align:start position:0% +a beam of the magic number so we start + + + align:start position:0% +a beam of the magic number so we start +at start at the point b1 and follow this + + align:start position:0% +at start at the point b1 and follow this + + + align:start position:0% +at start at the point b1 and follow this +path then the X's are the same B times + + align:start position:0% +path then the X's are the same B times + + + align:start position:0% +path then the X's are the same B times +this quantity to the case power and + + align:start position:0% +this quantity to the case power and + + + align:start position:0% +this quantity to the case power and +here's that quantity B minus 1 over B + + align:start position:0% +here's that quantity B minus 1 over B + + + align:start position:0% +here's that quantity B minus 1 over B +plus 1 so you see for a small B that's + + align:start position:0% +plus 1 so you see for a small B that's + + + align:start position:0% +plus 1 so you see for a small B that's +that's a negative number so it's + + align:start position:0% +that's a negative number so it's + + + align:start position:0% +that's a negative number so it's +flipping sign in the X's as we saw on + + align:start position:0% +flipping sign in the X's as we saw on + + + align:start position:0% +flipping sign in the X's as we saw on +the pictures + + align:start position:0% +the pictures + + + align:start position:0% +the pictures +leave that part of the picture is + + align:start position:0% +leave that part of the picture is + + + align:start position:0% +leave that part of the picture is +correct the Y's don't flip sign so this + + align:start position:0% +correct the Y's don't flip sign so this + + + align:start position:0% +correct the Y's don't flip sign so this +was XK and when K is 0 we got B YK is I + + align:start position:0% +was XK and when K is 0 we got B YK is I + + + align:start position:0% +was XK and when K is 0 we got B YK is I +think is is not flipping a sign so that + + align:start position:0% +think is is not flipping a sign so that + + + align:start position:0% +think is is not flipping a sign so that +looks good and then FK the value of F + + align:start position:0% +looks good and then FK the value of F + + + align:start position:0% +looks good and then FK the value of F +also was the same quantity + + align:start position:0% +also was the same quantity + + + align:start position:0% +also was the same quantity +FK is that same quantity to the case + + align:start position:0% +FK is that same quantity to the case + + + align:start position:0% +FK is that same quantity to the case +times f0 + + align:start position:0% +times f0 + + + align:start position:0% +times f0 +so that quantity is all all-important + + align:start position:0% +so that quantity is all all-important + + + align:start position:0% +so that quantity is all all-important +and so the purpose of today's lecture is + + align:start position:0% +and so the purpose of today's lecture is + + + align:start position:0% +and so the purpose of today's lecture is +to tell you what the momentum term what + + align:start position:0% +to tell you what the momentum term what + + + align:start position:0% +to tell you what the momentum term what +improvement what change that brings in + + align:start position:0% +improvement what change that brings in + + + align:start position:0% +improvement what change that brings in +the basic steepest descent formula I'm + + align:start position:0% +the basic steepest descent formula I'm + + + align:start position:0% +the basic steepest descent formula I'm +gonna add on another term which is going + + align:start position:0% +gonna add on another term which is going + + + align:start position:0% +gonna add on another term which is going +to have some give us some memory of the + + align:start position:0% +to have some give us some memory of the + + + align:start position:0% +to have some give us some memory of the +previous step and so when I do that + + align:start position:0% +previous step and so when I do that + + + align:start position:0% +previous step and so when I do that +I want to track that kind of descent for + + align:start position:0% +I want to track that kind of descent for + + + align:start position:0% +I want to track that kind of descent for +for the new for the accelerated descent + + align:start position:0% +for the new for the accelerated descent + + + align:start position:0% +for the new for the accelerated descent +and track it and see what improvement + + align:start position:0% +and track it and see what improvement + + + align:start position:0% +and track it and see what improvement +the momentum term brings and so the + + align:start position:0% +the momentum term brings and so the + + + align:start position:0% +the momentum term brings and so the +final result will be to tell you the + + align:start position:0% +final result will be to tell you the + + + align:start position:0% +final result will be to tell you the +improvement in the produce by the + + align:start position:0% +improvement in the produce by the + + + align:start position:0% +improvement in the produce by the +momentum term maybe while I have your + + align:start position:0% +momentum term maybe while I have your + + + align:start position:0% +momentum term maybe while I have your +attention I'll tell you what it is now + + align:start position:0% +attention I'll tell you what it is now + + + align:start position:0% +attention I'll tell you what it is now +and then we'll come the details the + + align:start position:0% +and then we'll come the details the + + + align:start position:0% +and then we'll come the details the +algebra and to me so this is my own + + align:start position:0% +algebra and to me so this is my own + + + align:start position:0% +algebra and to me so this is my own +thought it's a miracle that the algebra + + align:start position:0% +thought it's a miracle that the algebra + + + align:start position:0% +thought it's a miracle that the algebra +which is straightforward you really see + + align:start position:0% +which is straightforward you really see + + + align:start position:0% +which is straightforward you really see +the value of eigenvectors + + align:start position:0% +the value of eigenvectors + + + align:start position:0% +the value of eigenvectors +you know we explain eigenvectors in + + align:start position:0% +you know we explain eigenvectors in + + + align:start position:0% +you know we explain eigenvectors in +class but but here you see why what how + + align:start position:0% +class but but here you see why what how + + + align:start position:0% +class but but here you see why what how +to use them that's is really a good + + align:start position:0% +to use them that's is really a good + + + align:start position:0% +to use them that's is really a good +exercise but to me it's a miracle that + + align:start position:0% +exercise but to me it's a miracle that + + + align:start position:0% +exercise but to me it's a miracle that +the expression with momentum is very + + align:start position:0% +the expression with momentum is very + + + align:start position:0% +the expression with momentum is very +much like that expression but different + + align:start position:0% +much like that expression but different + + + align:start position:0% +much like that expression but different +of course the the the decay is a term + + align:start position:0% +of course the the the decay is a term + + + align:start position:0% +of course the the the decay is a term +that tells you how fast the decay is is + + align:start position:0% +that tells you how fast the decay is is + + + align:start position:0% +that tells you how fast the decay is is +smaller so you're taking K power so so + + align:start position:0% +smaller so you're taking K power so so + + + align:start position:0% +smaller so you're taking K power so so +let me I'll write that down if that's + + align:start position:0% +let me I'll write that down if that's + + + align:start position:0% +let me I'll write that down if that's +all right it's I didn't plan to do to + + align:start position:0% +all right it's I didn't plan to do to + + + align:start position:0% +all right it's I didn't plan to do to +reveal the final result at the beginning + + align:start position:0% +reveal the final result at the beginning + + + align:start position:0% +reveal the final result at the beginning +of the lecture but I think you want to + + align:start position:0% +of the lecture but I think you want to + + + align:start position:0% +of the lecture but I think you want to +see where we're going so so with + + align:start position:0% +see where we're going so so with + + + align:start position:0% +see where we're going so so with +momentum and we have to see what that + + align:start position:0% +momentum and we have to see what that + + + align:start position:0% +momentum and we have to see what that +means this this term of 1 minus B over 1 + + align:start position:0% +means this this term of 1 minus B over 1 + + + align:start position:0% +means this this term of 1 minus B over 1 +plus B becomes changes to + + align:start position:0% + + + + align:start position:0% + +one minus square root of B over 1 plus + + align:start position:0% +one minus square root of B over 1 plus + + + align:start position:0% +one minus square root of B over 1 plus +square would be so I mentioned that + + align:start position:0% +square would be so I mentioned that + + + align:start position:0% +square would be so I mentioned that +before but but I don't think I wrote it + + align:start position:0% +before but but I don't think I wrote it + + + align:start position:0% +before but but I don't think I wrote it +down just clearly so the miracle to me + + align:start position:0% +down just clearly so the miracle to me + + + align:start position:0% +down just clearly so the miracle to me +is to get such a nice expression for the + + align:start position:0% +is to get such a nice expression for the + + + align:start position:0% +is to get such a nice expression for the +because you'll see the algebra is it + + align:start position:0% +because you'll see the algebra is it + + + align:start position:0% +because you'll see the algebra is it +works but it's it's it involves more + + align:start position:0% +works but it's it's it involves more + + + align:start position:0% +works but it's it's it involves more +terms because of momentum involves doing + + align:start position:0% +terms because of momentum involves doing + + + align:start position:0% +terms because of momentum involves doing +a minimization of eigenvalues and yet it + + align:start position:0% +a minimization of eigenvalues and yet it + + + align:start position:0% +a minimization of eigenvalues and yet it +comes out nicely and and then you have + + align:start position:0% +comes out nicely and and then you have + + + align:start position:0% +comes out nicely and and then you have +to see the importance of that so let me + + align:start position:0% +to see the importance of that so let me + + + align:start position:0% +to see the importance of that so let me +I would just take the same example that + + align:start position:0% +I would just take the same example that + + + align:start position:0% +I would just take the same example that +I mentioned before if B is 1 over 100 + + align:start position:0% +I mentioned before if B is 1 over 100 + + + align:start position:0% +I mentioned before if B is 1 over 100 +then this is 0.99 over 1.01 oh I think + + align:start position:0% +then this is 0.99 over 1.01 oh I think + + + align:start position:0% +then this is 0.99 over 1.01 oh I think +that these there's a square here 2 K so + + align:start position:0% +that these there's a square here 2 K so + + + align:start position:0% +that these there's a square here 2 K so +if we're so I'll I'll just keep this + + align:start position:0% +if we're so I'll I'll just keep this + + + align:start position:0% +if we're so I'll I'll just keep this +square there no big change but but I'm + + align:start position:0% +square there no big change but but I'm + + + align:start position:0% +square there no big change but but I'm +looking at now here at the square + + align:start position:0% + + + + align:start position:0% + +maybe maybe squares are everywhere you + + align:start position:0% +maybe maybe squares are everywhere you + + + align:start position:0% +maybe maybe squares are everywhere you +know ok so so that's close to 1 and now + + align:start position:0% +know ok so so that's close to 1 and now + + + align:start position:0% +know ok so so that's close to 1 and now +let's compare that with what we have so + + align:start position:0% +let's compare that with what we have so + + + align:start position:0% +let's compare that with what we have so +if B is 1 over 100 so I'm taking V to be + + align:start position:0% +if B is 1 over 100 so I'm taking V to be + + + align:start position:0% +if B is 1 over 100 so I'm taking V to be +1 over 100 then square root of B is 1 + + align:start position:0% +1 over 100 then square root of B is 1 + + + align:start position:0% +1 over 100 then square root of B is 1 +over 10 so this is 0.9 0.9 over 1.1 + + align:start position:0% +over 10 so this is 0.9 0.9 over 1.1 + + + align:start position:0% +over 10 so this is 0.9 0.9 over 1.1 +squared and there's a tremendous um + + align:start position:0% +squared and there's a tremendous um + + + align:start position:0% +squared and there's a tremendous um +block smaller than that is right + + align:start position:0% +block smaller than that is right + + + align:start position:0% +block smaller than that is right +9/10 9 9 / 11 compared to 99 over 101 + + align:start position:0% +9/10 9 9 / 11 compared to 99 over 101 + + + align:start position:0% +9/10 9 9 / 11 compared to 99 over 101 +this one is you know is definitely oh + + align:start position:0% +this one is you know is definitely oh + + + align:start position:0% +this one is you know is definitely oh +sorry it's yeah it's this this reduction + + align:start position:0% +sorry it's yeah it's this this reduction + + + align:start position:0% +sorry it's yeah it's this this reduction +factor is well below that one so it's a + + align:start position:0% +factor is well below that one so it's a + + + align:start position:0% +factor is well below that one so it's a +good thing it's worth doing and okay + + align:start position:0% +good thing it's worth doing and okay + + + align:start position:0% +good thing it's worth doing and okay +now what is it involved okay so I'll + + align:start position:0% +now what is it involved okay so I'll + + + align:start position:0% +now what is it involved okay so I'll +write down the expression for the for + + align:start position:0% +write down the expression for the for + + + align:start position:0% +write down the expression for the for +the sarcastic here we go okay + + align:start position:0% +the sarcastic here we go okay + + + align:start position:0% +the sarcastic here we go okay +so here's one way to see it the new X is + + align:start position:0% +so here's one way to see it the new X is + + + align:start position:0% +so here's one way to see it the new X is +the old X minus the gradient and now + + align:start position:0% +the old X minus the gradient and now + + + align:start position:0% +the old X minus the gradient and now +comes an extra term which gives us a + + align:start position:0% +comes an extra term which gives us a + + + align:start position:0% +comes an extra term which gives us a +little memory well I'm sorry the the + + align:start position:0% +little memory well I'm sorry the the + + + align:start position:0% +little memory well I'm sorry the the +algebra is slightly nicer if I write it + + align:start position:0% +algebra is slightly nicer if I write it + + + align:start position:0% +algebra is slightly nicer if I write it +a little bit differently I'll create a + + align:start position:0% +a little bit differently I'll create a + + + align:start position:0% +a little bit differently I'll create a +new quantity ZK with a step size okay + + align:start position:0% + + + + align:start position:0% + +okay so if I took ZK to be just the + + align:start position:0% +okay so if I took ZK to be just the + + + align:start position:0% +okay so if I took ZK to be just the +gradient that would be steepest descent + + align:start position:0% +gradient that would be steepest descent + + + align:start position:0% +gradient that would be steepest descent +nothing has changed but instead I'm + + align:start position:0% +nothing has changed but instead I'm + + + align:start position:0% +nothing has changed but instead I'm +gonna take ZK well its leading term will + + align:start position:0% +gonna take ZK well its leading term will + + + align:start position:0% +gonna take ZK well its leading term will +be the gradient but here comes the + + align:start position:0% +be the gradient but here comes the + + + align:start position:0% +be the gradient but here comes the +momentum term I add on a multiple beta + + align:start position:0% +momentum term I add on a multiple beta + + + align:start position:0% +momentum term I add on a multiple beta +one way to do it is of the previous Z so + + align:start position:0% +one way to do it is of the previous Z so + + + align:start position:0% +one way to do it is of the previous Z so +the Z is the search direction z is the + + align:start position:0% +the Z is the search direction z is the + + + align:start position:0% +the Z is the search direction z is the +gradient you're traveling it's the + + align:start position:0% +gradient you're traveling it's the + + + align:start position:0% +gradient you're traveling it's the +direction you're moving so it's + + align:start position:0% +direction you're moving so it's + + + align:start position:0% +direction you're moving so it's +different from that direction there that + + align:start position:0% +different from that direction there that + + + align:start position:0% +different from that direction there that +direction was the gradient this + + align:start position:0% +direction was the gradient this + + + align:start position:0% +direction was the gradient this +direction is the gradient correct + + align:start position:0% +direction is the gradient correct + + + align:start position:0% +direction is the gradient correct +corrected by a memory term a momentum + + align:start position:0% +corrected by a memory term a momentum + + + align:start position:0% +corrected by a memory term a momentum +term and one way to interpret that is to + + align:start position:0% +term and one way to interpret that is to + + + align:start position:0% +term and one way to interpret that is to +say that that ball is to think of a + + align:start position:0% +say that that ball is to think of a + + + align:start position:0% +say that that ball is to think of a +heavy ball instead of just a point I + + align:start position:0% +heavy ball instead of just a point I + + + align:start position:0% +heavy ball instead of just a point I +think of a heavy ball it instead of + + align:start position:0% +think of a heavy ball it instead of + + + align:start position:0% +think of a heavy ball it instead of +bouncing back and forth as as as as + + align:start position:0% +bouncing back and forth as as as as + + + align:start position:0% +bouncing back and forth as as as as +uselessly as this one it tends to + + align:start position:0% +uselessly as this one it tends to + + + align:start position:0% +uselessly as this one it tends to +it still bounces of course on the sides + + align:start position:0% +it still bounces of course on the sides + + + align:start position:0% +it still bounces of course on the sides +of the level sets but it comes down the + + align:start position:0% +of the level sets but it comes down the + + + align:start position:0% +of the level sets but it comes down the +valley faster and that's the effect of + + align:start position:0% +valley faster and that's the effect of + + + align:start position:0% +valley faster and that's the effect of +this so so you could play with different + + align:start position:0% +this so so you could play with different + + + align:start position:0% +this so so you could play with different +adjustment terms different Corrections + + align:start position:0% +adjustment terms different Corrections + + + align:start position:0% +adjustment terms different Corrections +so but I'll follow through this one + + align:start position:0% +so but I'll follow through this one + + + align:start position:0% +so but I'll follow through this one +Nesterov had another way to make a + + align:start position:0% +Nesterov had another way to make a + + + align:start position:0% +Nesterov had another way to make a +change in the formula and the there are + + align:start position:0% +change in the formula and the there are + + + align:start position:0% +change in the formula and the there are +certainly others beyond that okay + + align:start position:0% +certainly others beyond that okay + + + align:start position:0% +certainly others beyond that okay +so how do we analyze that one well + + align:start position:0% +so how do we analyze that one well + + + align:start position:0% +so how do we analyze that one well +they're the real point is we've sort of + + align:start position:0% +they're the real point is we've sort of + + + align:start position:0% +they're the real point is we've sort of +by taking by involving the previous step + + align:start position:0% +by taking by involving the previous step + + + align:start position:0% +by taking by involving the previous step +we now have a three level method instead + + align:start position:0% +we now have a three level method instead + + + align:start position:0% +we now have a three level method instead +of a two level method you could say + + align:start position:0% +of a two level method you could say + + + align:start position:0% +of a two level method you could say +there's this this involves only level k + + align:start position:0% +there's this this involves only level k + + + align:start position:0% +there's this this involves only level k +plus 1 and level K the formulas now + + align:start position:0% +plus 1 and level K the formulas now + + + align:start position:0% +plus 1 and level K the formulas now +involve k plus 1 k and k minus 1 it's + + align:start position:0% +involve k plus 1 k and k minus 1 it's + + + align:start position:0% +involve k plus 1 k and k minus 1 it's +just like going from a first-order + + align:start position:0% +just like going from a first-order + + + align:start position:0% +just like going from a first-order +differential equation to a second-order + + align:start position:0% +differential equation to a second-order + + + align:start position:0% +differential equation to a second-order +differential equation + + align:start position:0% +differential equation + + + align:start position:0% +differential equation +it's it's I'm not really thinking that K + + align:start position:0% +it's it's I'm not really thinking that K + + + align:start position:0% +it's it's I'm not really thinking that K +is a is a time variable but in the + + align:start position:0% +is a is a time variable but in the + + + align:start position:0% +is a is a time variable but in the +analogy K could be a time variable so + + align:start position:0% +analogy K could be a time variable so + + + align:start position:0% +analogy K could be a time variable so +that here we had like a first-order + + align:start position:0% +that here we had like a first-order + + + align:start position:0% +that here we had like a first-order +equation if I wanted to model that + + align:start position:0% +equation if I wanted to model that + + + align:start position:0% +equation if I wanted to model that +that's sort of a DX DT coming in there + + align:start position:0% +that's sort of a DX DT coming in there + + + align:start position:0% +that's sort of a DX DT coming in there +equal a gradient and and these models + + align:start position:0% +equal a gradient and and these models + + + align:start position:0% +equal a gradient and and these models +are highly useful and and developed for + + align:start position:0% +are highly useful and and developed for + + + align:start position:0% +are highly useful and and developed for +sort of a continuous model of steepest + + align:start position:0% +sort of a continuous model of steepest + + + align:start position:0% +sort of a continuous model of steepest +descent a continuous motion instead of + + align:start position:0% +descent a continuous motion instead of + + + align:start position:0% +descent a continuous motion instead of +the instead of the discrete motion okay + + align:start position:0% +the instead of the discrete motion okay + + + align:start position:0% +the instead of the discrete motion okay +so that would that's continuous model + + align:start position:0% +so that would that's continuous model + + + align:start position:0% +so that would that's continuous model +for that guy would be a first order in + + align:start position:0% +for that guy would be a first order in + + + align:start position:0% +for that guy would be a first order in +time for this one it'll be second order + + align:start position:0% +time for this one it'll be second order + + + align:start position:0% +time for this one it'll be second order +in time and second order equations of + + align:start position:0% +in time and second order equations of + + + align:start position:0% +in time and second order equations of +course and the be constant coefficients + + align:start position:0% +course and the be constant coefficients + + + align:start position:0% +course and the be constant coefficients +in our model problem and the thing about + + align:start position:0% +in our model problem and the thing about + + + align:start position:0% +in our model problem and the thing about +a second-order equation that we all know + + align:start position:0% +a second-order equation that we all know + + + align:start position:0% +a second-order equation that we all know +there's a momentum term a a damping term + + align:start position:0% +there's a momentum term a a damping term + + + align:start position:0% +there's a momentum term a a damping term +you could say in multiplying the first + + align:start position:0% +you could say in multiplying the first + + + align:start position:0% +you could say in multiplying the first +derivative so that's what that's what a + + align:start position:0% +derivative so that's what that's what a + + + align:start position:0% +derivative so that's what that's what a +second-order equation offers is the + + align:start position:0% +second-order equation offers is the + + + align:start position:0% +second-order equation offers is the +inclusion of a damping term which isn't + + align:start position:0% +inclusion of a damping term which isn't + + + align:start position:0% +inclusion of a damping term which isn't +present in the in the original + + align:start position:0% +present in the in the original + + + align:start position:0% +present in the in the original +first-order okay so how do we analyze + + align:start position:0% +first-order okay so how do we analyze + + + align:start position:0% +first-order okay so how do we analyze +this I have to so how do you analyze + + align:start position:0% +this I have to so how do you analyze + + + align:start position:0% +this I have to so how do you analyze +second-order differential equations you + + align:start position:0% +second-order differential equations you + + + align:start position:0% +second-order differential equations you +write them as a system of two first + + align:start position:0% +write them as a system of two first + + + align:start position:0% +write them as a system of two first +order equations so that's exactly what + + align:start position:0% +order equations so that's exactly what + + + align:start position:0% +order equations so that's exactly what +we're going to do here in the discrete + + align:start position:0% +we're going to do here in the discrete + + + align:start position:0% +we're going to do here in the discrete +case we're going to see of course we + + align:start position:0% +case we're going to see of course we + + + align:start position:0% +case we're going to see of course we +have two equations and their first order + + align:start position:0% +have two equations and their first order + + + align:start position:0% +have two equations and their first order +and and we can let me play with them for + + align:start position:0% +and and we can let me play with them for + + + align:start position:0% +and and we can let me play with them for +a moment to to make them good okay so + + align:start position:0% +a moment to to make them good okay so + + + align:start position:0% +a moment to to make them good okay so +I'm gonna have so this will go to 2 + + align:start position:0% +I'm gonna have so this will go to 2 + + + align:start position:0% +I'm gonna have so this will go to 2 +first order equations in which the first + + align:start position:0% +first order equations in which the first + + + align:start position:0% +first order equations in which the first +one I'm just gonna copy XK plus 1 is XK + + align:start position:0% +one I'm just gonna copy XK plus 1 is XK + + + align:start position:0% +one I'm just gonna copy XK plus 1 is XK +minus at step size ZK whew yeah ok yeah + + align:start position:0% +minus at step size ZK whew yeah ok yeah + + + align:start position:0% +minus at step size ZK whew yeah ok yeah +ok time the previous times type here the + + align:start position:0% +ok time the previous times type here the + + + align:start position:0% +ok time the previous times type here the +the next time step on the left okay so I + + align:start position:0% +the next time step on the left okay so I + + + align:start position:0% +the next time step on the left okay so I +just copied that now this one I'm going + + align:start position:0% +just copied that now this one I'm going + + + align:start position:0% +just copied that now this one I'm going +to increase K by 1 so in order to have + + align:start position:0% +to increase K by 1 so in order to have + + + align:start position:0% +to increase K by 1 so in order to have +that looking to match this I'll write + + align:start position:0% +that looking to match this I'll write + + + align:start position:0% +that looking to match this I'll write +that as Z K plus 1 and I'll bring the + + align:start position:0% +that as Z K plus 1 and I'll bring the + + + align:start position:0% +that as Z K plus 1 and I'll bring the +case ain't grad F k plus 1 equal beta ZK + + align:start position:0% +case ain't grad F k plus 1 equal beta ZK + + + align:start position:0% +case ain't grad F k plus 1 equal beta ZK +that look with you I just in this in + + align:start position:0% +that look with you I just in this in + + + align:start position:0% +that look with you I just in this in +this thing instead of looking at it at + + align:start position:0% +this thing instead of looking at it at + + + align:start position:0% +this thing instead of looking at it at +ki I went to K plus 1 and I put the K + + align:start position:0% +ki I went to K plus 1 and I put the K + + + align:start position:0% +ki I went to K plus 1 and I put the K +plus 1 terms on one side okay so now I + + align:start position:0% +plus 1 terms on one side okay so now I + + + align:start position:0% +plus 1 terms on one side okay so now I +have a a + + align:start position:0% + + + + align:start position:0% + +and let's see let's remember we're doing + + align:start position:0% +and let's see let's remember we're doing + + + align:start position:0% +and let's see let's remember we're doing +our the model we're doing is f equal up + + align:start position:0% +our the model we're doing is f equal up + + + align:start position:0% +our the model we're doing is f equal up +1/2 X transpose s X so the gradient of F + + align:start position:0% +1/2 X transpose s X so the gradient of F + + + align:start position:0% +1/2 X transpose s X so the gradient of F +is s X so what I've written there or + + align:start position:0% +is s X so what I've written there or + + + align:start position:0% +is s X so what I've written there or +gradient is really I know what that + + align:start position:0% +gradient is really I know what that + + + align:start position:0% +gradient is really I know what that +gradient is so that's really s xk plus + + align:start position:0% +gradient is so that's really s xk plus + + + align:start position:0% +gradient is so that's really s xk plus +okay okay how to analyze that what + + align:start position:0% +okay okay how to analyze that what + + + align:start position:0% +okay okay how to analyze that what +happens as K as K travels forward one + + align:start position:0% +happens as K as K travels forward one + + + align:start position:0% +happens as K as K travels forward one +two three four five we have a constant + + align:start position:0% +two three four five we have a constant + + + align:start position:0% +two three four five we have a constant +coefficient problem at every step the XZ + + align:start position:0% +coefficient problem at every step the XZ + + + align:start position:0% +coefficient problem at every step the XZ +variable is getting multiplied by a + + align:start position:0% +variable is getting multiplied by a + + + align:start position:0% +variable is getting multiplied by a +matrix so here's X Z at k plus 1 and + + align:start position:0% +matrix so here's X Z at k plus 1 and + + + align:start position:0% +matrix so here's X Z at k plus 1 and +over here will be X Z at step K and I + + align:start position:0% +over here will be X Z at step K and I + + + align:start position:0% +over here will be X Z at step K and I +just have to figure out what matrix is + + align:start position:0% +just have to figure out what matrix is + + + align:start position:0% +just have to figure out what matrix is +multiplying here and here okay and I + + align:start position:0% +multiplying here and here okay and I + + + align:start position:0% +multiplying here and here okay and I +guess here I see it if the first + + align:start position:0% +guess here I see it if the first + + + align:start position:0% +guess here I see it if the first +equation has a 1 and a minus s looks + + align:start position:0% +equation has a 1 and a minus s looks + + + align:start position:0% +equation has a 1 and a minus s looks +like in the first row and it has a beta + + align:start position:0% +like in the first row and it has a beta + + + align:start position:0% +like in the first row and it has a beta +in the second row and here the first + + align:start position:0% +in the second row and here the first + + + align:start position:0% +in the second row and here the first +equation has a 1 0 in that row and then + + align:start position:0% +equation has a 1 0 in that row and then + + + align:start position:0% +equation has a 1 0 in that row and then +a minus s I'll put in minus s + + align:start position:0% +a minus s I'll put in minus s + + + align:start position:0% +a minus s I'll put in minus s +multiplying XK plus 1 and then the one + + align:start position:0% +multiplying XK plus 1 and then the one + + + align:start position:0% +multiplying XK plus 1 and then the one +that multiplies ZK plus 1 is that all + + align:start position:0% +that multiplies ZK plus 1 is that all + + + align:start position:0% +that multiplies ZK plus 1 is that all +right + + align:start position:0% + + + + align:start position:0% + +sorry I've got 2 SS and I didn't draw + + align:start position:0% +sorry I've got 2 SS and I didn't draw + + + align:start position:0% +sorry I've got 2 SS and I didn't draw +that one didn't write that one in large + + align:start position:0% +that one didn't write that one in large + + + align:start position:0% +that one didn't write that one in large +enough and I'd plan to erase it anyway + + align:start position:0% +enough and I'd plan to erase it anyway + + + align:start position:0% +enough and I'd plan to erase it anyway +this is the this is the step size this + + align:start position:0% +this is the this is the step size this + + + align:start position:0% +this is the this is the step size this +this is the matrix but but it's it's not + + align:start position:0% +this is the matrix but but it's it's not + + + align:start position:0% +this is the matrix but but it's it's not +it's not quite fitting it's placed this + + align:start position:0% +it's not quite fitting it's placed this + + + align:start position:0% +it's not quite fitting it's placed this +is the point where I'm gonna use eigen + + align:start position:0% +is the point where I'm gonna use eigen + + + align:start position:0% +is the point where I'm gonna use eigen +values I'm gonna follow an I follow each + + align:start position:0% +values I'm gonna follow an I follow each + + + align:start position:0% +values I'm gonna follow an I follow each +eigen value that's the whole point when + + align:start position:0% +eigen value that's the whole point when + + + align:start position:0% +eigen value that's the whole point when +I follow each eigen value + + align:start position:0% +I follow each eigen value + + + align:start position:0% +I follow each eigen value +each eigenvector I should say I'll + + align:start position:0% +each eigenvector I should say I'll + + + align:start position:0% +each eigenvector I should say I'll +follow each eigenvector of s so let's + + align:start position:0% +follow each eigenvector of s so let's + + + align:start position:0% +follow each eigenvector of s so let's +let's do that so so I can vectors of s + + align:start position:0% +let's do that so so I can vectors of s + + + align:start position:0% +let's do that so so I can vectors of s +what are we gonna call those lambda + + align:start position:0% +what are we gonna call those lambda + + + align:start position:0% +what are we gonna call those lambda +probably so s X equal lambda X I think + + align:start position:0% +probably so s X equal lambda X I think + + + align:start position:0% +probably so s X equal lambda X I think +that's what's coming or Q I to do things + + align:start position:0% +that's what's coming or Q I to do things + + + align:start position:0% +that's what's coming or Q I to do things +right I want to remember that s is a + + align:start position:0% +right I want to remember that s is a + + + align:start position:0% +right I want to remember that s is a +positive definite symmetric matrix + + align:start position:0% +positive definite symmetric matrix + + + align:start position:0% +positive definite symmetric matrix +that's why I called it s instead of a so + + align:start position:0% +that's why I called it s instead of a so + + + align:start position:0% +that's why I called it s instead of a so +I really should call the eigen it + + align:start position:0% +I really should call the eigen it + + + align:start position:0% +I really should call the eigen it +doesn't matter but to be on the ball let + + align:start position:0% +doesn't matter but to be on the ball let + + + align:start position:0% +doesn't matter but to be on the ball let +me call the eigen vector Q and the eigen + + align:start position:0% +me call the eigen vector Q and the eigen + + + align:start position:0% +me call the eigen vector Q and the eigen +value lambda okay okay so now I want to + + align:start position:0% +value lambda okay okay so now I want to + + + align:start position:0% +value lambda okay okay so now I want to +I want to follow this eigen vector so + + align:start position:0% +I want to follow this eigen vector so + + + align:start position:0% +I want to follow this eigen vector so +I'm supposing that X K is some C K times + + align:start position:0% +I'm supposing that X K is some C K times + + + align:start position:0% +I'm supposing that X K is some C K times +Q I'm assuming that X is in the tracking + + align:start position:0% +Q I'm assuming that X is in the tracking + + + align:start position:0% +Q I'm assuming that X is in the tracking +this eigen vector and I'm gonna assume + + align:start position:0% +this eigen vector and I'm gonna assume + + + align:start position:0% +this eigen vector and I'm gonna assume +that ZK is some other constant times Q + + align:start position:0% +that ZK is some other constant times Q + + + align:start position:0% +that ZK is some other constant times Q +everybody do you see that's a vector and + + align:start position:0% +everybody do you see that's a vector and + + + align:start position:0% +everybody do you see that's a vector and +that's a vector and I want scalars I + + align:start position:0% +that's a vector and I want scalars I + + + align:start position:0% +that's a vector and I want scalars I +want to attract just scalar C K and D K + + align:start position:0% +want to attract just scalar C K and D K + + + align:start position:0% +want to attract just scalar C K and D K +so that's really what I have here is + + align:start position:0% +so that's really what I have here is + + + align:start position:0% +so that's really what I have here is +this was a little tricky because X here + + align:start position:0% +this was a little tricky because X here + + + align:start position:0% +this was a little tricky because X here +is a vector and two components are n + + align:start position:0% +is a vector and two components are n + + + align:start position:0% +is a vector and two components are n +components I didn't want that I really + + align:start position:0% +components I didn't want that I really + + + align:start position:0% +components I didn't want that I really +wanted just to track an eigen vector + + align:start position:0% +wanted just to track an eigen vector + + + align:start position:0% +wanted just to track an eigen vector +once I've settled on the direction Q + + align:start position:0% +once I've settled on the direction Q + + + align:start position:0% +once I've settled on the direction Q +everything is all vectors are in the + + align:start position:0% +everything is all vectors are in the + + + align:start position:0% +everything is all vectors are in the +direction of Q so so we just have + + align:start position:0% +direction of Q so so we just have + + + align:start position:0% +direction of Q so so we just have +numbers see indeed a track okay so I'm + + align:start position:0% +numbers see indeed a track okay so I'm + + + align:start position:0% +numbers see indeed a track okay so I'm +gonna rewrite this + + align:start position:0% +gonna rewrite this + + + align:start position:0% +gonna rewrite this +correctly as yeah well let me keep keep + + align:start position:0% +correctly as yeah well let me keep keep + + + align:start position:0% +correctly as yeah well let me keep keep +going with this little formula then what + + align:start position:0% +going with this little formula then what + + + align:start position:0% +going with this little formula then what +will I needed an SX what will s xk be if + + align:start position:0% +will I needed an SX what will s xk be if + + + align:start position:0% +will I needed an SX what will s xk be if +if xk is in the direction of the eigen + + align:start position:0% +if xk is in the direction of the eigen + + + align:start position:0% +if xk is in the direction of the eigen +vector Q and its CK what happens when I + + align:start position:0% +vector Q and its CK what happens when I + + + align:start position:0% +vector Q and its CK what happens when I +multiply by yes q was an eigen vector so + + align:start position:0% +multiply by yes q was an eigen vector so + + + align:start position:0% +multiply by yes q was an eigen vector so +the multiplying by s gives me I can + + align:start position:0% +the multiplying by s gives me I can + + + align:start position:0% +the multiplying by s gives me I can +value right so it's C K lambda Q + + align:start position:0% +value right so it's C K lambda Q + + + align:start position:0% +value right so it's C K lambda Q +everything is a multiple of Q and it's + + align:start position:0% +everything is a multiple of Q and it's + + + align:start position:0% +everything is a multiple of Q and it's +only those multiples I'm looking for the + + align:start position:0% +only those multiples I'm looking for the + + + align:start position:0% +only those multiples I'm looking for the +Seas and the DS and then the lambda + + align:start position:0% +Seas and the DS and then the lambda + + + align:start position:0% +Seas and the DS and then the lambda +comes into the S term yeah I think + + align:start position:0% +comes into the S term yeah I think + + + align:start position:0% +comes into the S term yeah I think +that's probably all I need to to do this + + align:start position:0% +that's probably all I need to to do this + + + align:start position:0% +that's probably all I need to to do this +and then the gradient yeah so that's the + + align:start position:0% +and then the gradient yeah so that's the + + + align:start position:0% +and then the gradient yeah so that's the +gradient of course this is the gradient + + align:start position:0% +gradient of course this is the gradient + + + align:start position:0% +gradient of course this is the gradient +of F okay so instead of this let me just + + align:start position:0% +of F okay so instead of this let me just + + + align:start position:0% +of F okay so instead of this let me just +write what's what's happening if I'm + + align:start position:0% +write what's what's happening if I'm + + + align:start position:0% +write what's what's happening if I'm +tracking the coefficients CK plus 1 and + + align:start position:0% +tracking the coefficients CK plus 1 and + + + align:start position:0% +tracking the coefficients CK plus 1 and +DK plus 1 then what I really meant to + + align:start position:0% +DK plus 1 then what I really meant to + + + align:start position:0% +DK plus 1 then what I really meant to +have there is 1 0 and minus s is a minus + + align:start position:0% +have there is 1 0 and minus s is a minus + + + align:start position:0% +have there is 1 0 and minus s is a minus +lambda is that right yeah when I + + align:start position:0% +lambda is that right yeah when I + + + align:start position:0% +lambda is that right yeah when I +multiply the eigenvector by s I'm just + + align:start position:0% +multiply the eigenvector by s I'm just + + + align:start position:0% +multiply the eigenvector by s I'm just +kidding oh it's a lambda times the CK + + align:start position:0% +kidding oh it's a lambda times the CK + + + align:start position:0% +kidding oh it's a lambda times the CK +yeah lambda times the CK that's good I + + align:start position:0% +yeah lambda times the CK that's good I + + + align:start position:0% +yeah lambda times the CK that's good I +think that that's the left-hand side of + + align:start position:0% +think that that's the left-hand side of + + + align:start position:0% +think that that's the left-hand side of +my equation and on the right hand side I + + align:start position:0% +my equation and on the right hand side I + + + align:start position:0% +my equation and on the right hand side I +have here that's 1 and this was the + + align:start position:0% +have here that's 1 and this was the + + + align:start position:0% +have here that's 1 and this was the +scalar the step size and this was the + + align:start position:0% +scalar the step size and this was the + + + align:start position:0% +scalar the step size and this was the +other coefficient it's the SN beta so I + + align:start position:0% +other coefficient it's the SN beta so I + + + align:start position:0% +other coefficient it's the SN beta so I +want to choose what's my purpose now + + align:start position:0% +want to choose what's my purpose now + + + align:start position:0% +want to choose what's my purpose now +that gives me the + + align:start position:0% + + + + align:start position:0% + +what happens at every step to the C and + + align:start position:0% +what happens at every step to the C and + + + align:start position:0% +what happens at every step to the C and +D so I want to choose the land the the + + align:start position:0% +D so I want to choose the land the the + + + align:start position:0% +D so I want to choose the land the the +two things that I have I'm free to + + align:start position:0% +two things that I have I'm free to + + + align:start position:0% +two things that I have I'm free to +choose our s and beta so that's my big + + align:start position:0% +choose our s and beta so that's my big + + + align:start position:0% +choose our s and beta so that's my big +big job choose s and beta okay now I to + + align:start position:0% +big job choose s and beta okay now I to + + + align:start position:0% +big job choose s and beta okay now I to +make oh let me just shape this thing up + + align:start position:0% +make oh let me just shape this thing up + + + align:start position:0% +make oh let me just shape this thing up +by month by multiplying the inverse of + + align:start position:0% +by month by multiplying the inverse of + + + align:start position:0% +by month by multiplying the inverse of +that and get it over here so that well + + align:start position:0% +that and get it over here so that well + + + align:start position:0% +that and get it over here so that well +really you'll see everything so CK plus + + align:start position:0% +really you'll see everything so CK plus + + + align:start position:0% +really you'll see everything so CK plus +one DK plus one what's the inverse of + + align:start position:0% +one DK plus one what's the inverse of + + + align:start position:0% +one DK plus one what's the inverse of +one zero + + align:start position:0% +one zero + + + align:start position:0% +one zero +oh I don't think I wanna that would have + + align:start position:0% +oh I don't think I wanna that would have + + + align:start position:0% +oh I don't think I wanna that would have +a tough time finding an inverse it was a + + align:start position:0% +a tough time finding an inverse it was a + + + align:start position:0% +a tough time finding an inverse it was a +one wasn't it yeah okay so I want to + + align:start position:0% +one wasn't it yeah okay so I want to + + + align:start position:0% +one wasn't it yeah okay so I want to +multiply by the inverse of that matrix + + align:start position:0% +multiply by the inverse of that matrix + + + align:start position:0% +multiply by the inverse of that matrix +to get it over here and what's the + + align:start position:0% +to get it over here and what's the + + + align:start position:0% +to get it over here and what's the +inverse of 1 1 minus lamda it's 1 1 plus + + align:start position:0% +inverse of 1 1 minus lamda it's 1 1 plus + + + align:start position:0% +inverse of 1 1 minus lamda it's 1 1 plus +lambda so that the inverse brought it + + align:start position:0% +lambda so that the inverse brought it + + + align:start position:0% +lambda so that the inverse brought it +over here times this matrix 1 0 beta and + + align:start position:0% +over here times this matrix 1 0 beta and + + + align:start position:0% +over here times this matrix 1 0 beta and +minus the step size that's what + + align:start position:0% +minus the step size that's what + + + align:start position:0% +minus the step size that's what +multiplies C KD K so we have these + + align:start position:0% +multiplies C KD K so we have these + + + align:start position:0% +multiplies C KD K so we have these +simple beautiful steps which which come + + align:start position:0% +simple beautiful steps which which come + + + align:start position:0% +simple beautiful steps which which come +from tracking one eigenvector makes the + + align:start position:0% +from tracking one eigenvector makes the + + + align:start position:0% +from tracking one eigenvector makes the +whole problem scalar so I multiply those + + align:start position:0% +whole problem scalar so I multiply those + + + align:start position:0% +whole problem scalar so I multiply those +two matrices in our I finally get the + + align:start position:0% +two matrices in our I finally get the + + + align:start position:0% +two matrices in our I finally get the +matrix that I really have to think about + + align:start position:0% +matrix that I really have to think about + + + align:start position:0% +matrix that I really have to think about +1 0 times that'll be 1 minus s lambda 1 + + align:start position:0% +1 0 times that'll be 1 minus s lambda 1 + + + align:start position:0% +1 0 times that'll be 1 minus s lambda 1 +times that will be a lambda there and + + align:start position:0% +times that will be a lambda there and + + + align:start position:0% +times that will be a lambda there and +minus lambda s plus beta beta minus + + align:start position:0% +minus lambda s plus beta beta minus + + + align:start position:0% +minus lambda s plus beta beta minus +lambda s that's the matrix that we see + + align:start position:0% +lambda s that's the matrix that we see + + + align:start position:0% +lambda s that's the matrix that we see +at every step let me call that matrix Oh + + align:start position:0% + + + + align:start position:0% + +so I've done some algebra more than I + + align:start position:0% +so I've done some algebra more than I + + + align:start position:0% +so I've done some algebra more than I +would always do in a lecture but it's + + align:start position:0% +would always do in a lecture but it's + + + align:start position:0% +would always do in a lecture but it's +really my I wouldn't do it if it wasn't + + align:start position:0% +really my I wouldn't do it if it wasn't + + + align:start position:0% +really my I wouldn't do it if it wasn't +nice algebra what's the conclusion the + + align:start position:0% +nice algebra what's the conclusion the + + + align:start position:0% +nice algebra what's the conclusion the +conclusion is that with the momentum + + align:start position:0% +conclusion is that with the momentum + + + align:start position:0% +conclusion is that with the momentum +term with this number beta available to + + align:start position:0% +term with this number beta available to + + + align:start position:0% +term with this number beta available to +choose as well as s the step the + + align:start position:0% +choose as well as s the step the + + + align:start position:0% +choose as well as s the step the +coefficient of the eigenvalue + + align:start position:0% +coefficient of the eigenvalue + + + align:start position:0% +coefficient of the eigenvalue +eigenvector is multiplied at every step + + align:start position:0% +eigenvector is multiplied at every step + + + align:start position:0% +eigenvector is multiplied at every step +by that matrix r r is that matrix and of + + align:start position:0% +by that matrix r r is that matrix and of + + + align:start position:0% +by that matrix r r is that matrix and of +course that matrix involves the + + align:start position:0% +course that matrix involves the + + + align:start position:0% +course that matrix involves the +eigenvalue yep so we have to think about + + align:start position:0% +eigenvalue yep so we have to think about + + + align:start position:0% +eigenvalue yep so we have to think about +what what do we want to do now we want + + align:start position:0% +what what do we want to do now we want + + + align:start position:0% +what what do we want to do now we want +to choose beta and s to make our as + + align:start position:0% +to choose beta and s to make our as + + + align:start position:0% +to choose beta and s to make our as +small as possible right we want to make + + align:start position:0% +small as possible right we want to make + + + align:start position:0% +small as possible right we want to make +our as small as possible and we're free + + align:start position:0% +our as small as possible and we're free + + + align:start position:0% +our as small as possible and we're free +to choose beta and s but we but our + + align:start position:0% +to choose beta and s but we but our + + + align:start position:0% +to choose beta and s but we but our +depends on lambda so I'm going to make + + align:start position:0% +depends on lambda so I'm going to make + + + align:start position:0% +depends on lambda so I'm going to make +it as small as possible over the whole + + align:start position:0% +it as small as possible over the whole + + + align:start position:0% +it as small as possible over the whole +range of possible lambdas so so let me + + align:start position:0% +range of possible lambdas so so let me + + + align:start position:0% +range of possible lambdas so so let me +so now here we really go so we have + + align:start position:0% +so now here we really go so we have + + + align:start position:0% +so now here we really go so we have +lambda between some these are these are + + align:start position:0% +lambda between some these are these are + + + align:start position:0% +lambda between some these are these are +the eigen eigen value of s and what we + + align:start position:0% +the eigen eigen value of s and what we + + + align:start position:0% +the eigen eigen value of s and what we +know what's what's reasonable to know is + + align:start position:0% +know what's what's reasonable to know is + + + align:start position:0% +know what's what's reasonable to know is +a lower bound it's a positive this is a + + align:start position:0% +a lower bound it's a positive this is a + + + align:start position:0% +a lower bound it's a positive this is a +symmetric positive definite matrix a + + align:start position:0% +symmetric positive definite matrix a + + + align:start position:0% +symmetric positive definite matrix a +lower bound and an upper bound for + + align:start position:0% +lower bound and an upper bound for + + + align:start position:0% +lower bound and an upper bound for +example and M was B and M was one in + + align:start position:0% +example and M was B and M was one in + + + align:start position:0% +example and M was B and M was one in +that two-by-two problem and this is what + + align:start position:0% +that two-by-two problem and this is what + + + align:start position:0% +that two-by-two problem and this is what +we know that the eigen values are + + align:start position:0% +we know that the eigen values are + + + align:start position:0% +we know that the eigen values are +between M&M and the ratio of + + align:start position:0% + + + + align:start position:0% + +m2m well if I buy right this is the this + + align:start position:0% +m2m well if I buy right this is the this + + + align:start position:0% +m2m well if I buy right this is the this +is the key quantity and what's it called + + align:start position:0% +is the key quantity and what's it called + + + align:start position:0% +is the key quantity and what's it called +lambda max divided by lambda min is the + + align:start position:0% +lambda max divided by lambda min is the + + + align:start position:0% +lambda max divided by lambda min is the +condition number right this is all + + align:start position:0% +condition number right this is all + + + align:start position:0% +condition number right this is all +sometimes written Kappa Greek letter + + align:start position:0% +sometimes written Kappa Greek letter + + + align:start position:0% +sometimes written Kappa Greek letter +Kappa the condition number of s and when + + align:start position:0% +Kappa the condition number of s and when + + + align:start position:0% +Kappa the condition number of s and when +that's big that then the problem is + + align:start position:0% +that's big that then the problem is + + + align:start position:0% +that's big that then the problem is +going to be harder when that's one that + + align:start position:0% +going to be harder when that's one that + + + align:start position:0% +going to be harder when that's one that +then the matrix is just a multiple of + + align:start position:0% +then the matrix is just a multiple of + + + align:start position:0% +then the matrix is just a multiple of +the identity matrix and the problem is + + align:start position:0% +the identity matrix and the problem is + + + align:start position:0% +the identity matrix and the problem is +trivial when this when when when capital + + align:start position:0% +trivial when this when when when capital + + + align:start position:0% +trivial when this when when when capital +in it m and small m are the same then + + align:start position:0% +in it m and small m are the same then + + + align:start position:0% +in it m and small m are the same then +that's saying that the largest and + + align:start position:0% +that's saying that the largest and + + + align:start position:0% +that's saying that the largest and +smallest eigen values are identical that + + align:start position:0% +smallest eigen values are identical that + + + align:start position:0% +smallest eigen values are identical that +that the matrix is a multiple of the + + align:start position:0% +that the matrix is a multiple of the + + + align:start position:0% +that the matrix is a multiple of the +identity that's the condition number one + + align:start position:0% +identity that's the condition number one + + + align:start position:0% +identity that's the condition number one +but but the bad one is when it's 1 over + + align:start position:0% +but but the bad one is when it's 1 over + + + align:start position:0% +but but the bad one is when it's 1 over +B in our example and it and that could + + align:start position:0% +B in our example and it and that could + + + align:start position:0% +B in our example and it and that could +be very large okay that's where we have + + align:start position:0% +be very large okay that's where we have + + + align:start position:0% +be very large okay that's where we have +a problem let me just insert about the + + align:start position:0% +a problem let me just insert about the + + + align:start position:0% +a problem let me just insert about the +ordinary gradient descent of course the + + align:start position:0% +ordinary gradient descent of course the + + + align:start position:0% +ordinary gradient descent of course the +textbooks find a estimate for how fast + + align:start position:0% +textbooks find a estimate for how fast + + + align:start position:0% +textbooks find a estimate for how fast +that is and of course it depends on that + + align:start position:0% +that is and of course it depends on that + + + align:start position:0% +that is and of course it depends on that +number + + align:start position:0% +number + + + align:start position:0% +number +yeah so it depends on that number and E + + align:start position:0% +yeah so it depends on that number and E + + + align:start position:0% +yeah so it depends on that number and E +right you exactly saw how it depended on + + align:start position:0% +right you exactly saw how it depended on + + + align:start position:0% +right you exactly saw how it depended on +that number right but now we have a + + align:start position:0% +that number right but now we have a + + + align:start position:0% +that number right but now we have a +different problem and we're gonna finish + + align:start position:0% +different problem and we're gonna finish + + + align:start position:0% +different problem and we're gonna finish +it okay so what's my job I'm gonna + + align:start position:0% +it okay so what's my job I'm gonna + + + align:start position:0% +it okay so what's my job I'm gonna +choose s and beta to get to keep the the + + align:start position:0% +choose s and beta to get to keep the the + + + align:start position:0% +choose s and beta to get to keep the the +eigen values of R so let's give the + + align:start position:0% +eigen values of R so let's give the + + + align:start position:0% +eigen values of R so let's give the +eigen values of RNA so R let's say R has + + align:start position:0% +eigen values of RNA so R let's say R has + + + align:start position:0% +eigen values of RNA so R let's say R has +eigen values + + align:start position:0% + + + + align:start position:0% + +II won that depends on on the lambda and + + align:start position:0% +II won that depends on on the lambda and + + + align:start position:0% +II won that depends on on the lambda and +the s and the beta and E - so those are + + align:start position:0% +the s and the beta and E - so those are + + + align:start position:0% +the s and the beta and E - so those are +the eigenvalues of our just giving a + + align:start position:0% +the eigenvalues of our just giving a + + + align:start position:0% +the eigenvalues of our just giving a +letter to to them so what's our job we + + align:start position:0% +letter to to them so what's our job we + + + align:start position:0% +letter to to them so what's our job we +want to choose s and beta to make those + + align:start position:0% +want to choose s and beta to make those + + + align:start position:0% +want to choose s and beta to make those +eigenvalues as small as possible right + + align:start position:0% +eigenvalues as small as possible right + + + align:start position:0% +eigenvalues as small as possible right +small eigenvalues if r has small + + align:start position:0% +small eigenvalues if r has small + + + align:start position:0% +small eigenvalues if r has small +eigenvalues its powers see we ever every + + align:start position:0% +eigenvalues its powers see we ever every + + + align:start position:0% +eigenvalues its powers see we ever every +step multiplies by r so the convergence + + align:start position:0% +step multiplies by r so the convergence + + + align:start position:0% +step multiplies by r so the convergence +rate with momentum is depends on the + + align:start position:0% +rate with momentum is depends on the + + + align:start position:0% +rate with momentum is depends on the +powers of our getting small fast it + + align:start position:0% +powers of our getting small fast it + + + align:start position:0% +powers of our getting small fast it +depends on the eigenvalues being small + + align:start position:0% +depends on the eigenvalues being small + + + align:start position:0% +depends on the eigenvalues being small +we want to minimize the largest + + align:start position:0% +we want to minimize the largest + + + align:start position:0% +we want to minimize the largest +eigenvalue so I'll say the maximum of e + + align:start position:0% +eigenvalue so I'll say the maximum of e + + + align:start position:0% +eigenvalue so I'll say the maximum of e +1 and each and E 2 that's our job + + align:start position:0% +1 and each and E 2 that's our job + + + align:start position:0% +1 and each and E 2 that's our job +minimize we want to choose s and beta to + + align:start position:0% +minimize we want to choose s and beta to + + + align:start position:0% +minimize we want to choose s and beta to +minimize the largest eigenvalue because + + align:start position:0% +minimize the largest eigenvalue because + + + align:start position:0% +minimize the largest eigenvalue because +if there's one small eigenvalue but the + + align:start position:0% +if there's one small eigenvalue but the + + + align:start position:0% +if there's one small eigenvalue but the +other is big then the other one is going + + align:start position:0% +other is big then the other one is going + + + align:start position:0% +other is big then the other one is going +to kill us so we have to get both + + align:start position:0% +to kill us so we have to get both + + + align:start position:0% +to kill us so we have to get both +eigenvalues down and of course those + + align:start position:0% +eigenvalues down and of course those + + + align:start position:0% +eigenvalues down and of course those +depend on lambda e 1 depends on lambda + + align:start position:0% +depend on lambda e 1 depends on lambda + + + align:start position:0% +depend on lambda e 1 depends on lambda +so we have a little algebra problem and + + align:start position:0% +so we have a little algebra problem and + + + align:start position:0% +so we have a little algebra problem and +this is what I described as a miracle + + align:start position:0% +this is what I described as a miracle + + + align:start position:0% +this is what I described as a miracle +the fact that this little algebra + + align:start position:0% +the fact that this little algebra + + + align:start position:0% +the fact that this little algebra +problem the eigenvalues of that matrix + + align:start position:0% +problem the eigenvalues of that matrix + + + align:start position:0% +problem the eigenvalues of that matrix +e1 and e2 which depend on lambda in some + + align:start position:0% +e1 and e2 which depend on lambda in some + + + align:start position:0% +e1 and e2 which depend on lambda in some +in some way and we want to make both e1 + + align:start position:0% +in some way and we want to make both e1 + + + align:start position:0% +in some way and we want to make both e1 +and e2 small the maximum of those of + + align:start position:0% +and e2 small the maximum of those of + + + align:start position:0% +and e2 small the maximum of those of +them and we have to do it for all the + + align:start position:0% +them and we have to do it for all the + + + align:start position:0% +them and we have to do it for all the +eigen all the eigenvalues lambda because + + align:start position:0% +eigen all the eigenvalues lambda because + + + align:start position:0% +eigen all the eigenvalues lambda because +we have to we're now thinking we've been + + align:start position:0% +we have to we're now thinking we've been + + + align:start position:0% +we have to we're now thinking we've been +tracking each eigenvector so that gave + + align:start position:0% +tracking each eigenvector so that gave + + + align:start position:0% +tracking each eigenvector so that gave +us 1 so this is for all possible lambda + + align:start position:0% +us 1 so this is for all possible lambda + + + align:start position:0% +us 1 so this is for all possible lambda +oh so we have to decide what do I mean + + align:start position:0% +oh so we have to decide what do I mean + + + align:start position:0% +oh so we have to decide what do I mean +by all pasta + + align:start position:0% +by all pasta + + + align:start position:0% +by all pasta +lambda and I mean all lambda that are + + align:start position:0% +lambda and I mean all lambda that are + + + align:start position:0% +lambda and I mean all lambda that are +between some M&M there is a beautiful + + align:start position:0% +between some M&M there is a beautiful + + + align:start position:0% +between some M&M there is a beautiful +problem you have a two-by-two matrix you + + align:start position:0% +problem you have a two-by-two matrix you + + + align:start position:0% +problem you have a two-by-two matrix you +can find it it find its eigenvalues its + + align:start position:0% +can find it it find its eigenvalues its + + + align:start position:0% +can find it it find its eigenvalues its +it they depend on lambda and what we all + + align:start position:0% +it they depend on lambda and what we all + + + align:start position:0% +it they depend on lambda and what we all +we know about lambda is it's between m + + align:start position:0% +we know about lambda is it's between m + + + align:start position:0% +we know about lambda is it's between m +and and capya and also they also depend + + align:start position:0% +and and capya and also they also depend + + + align:start position:0% +and and capya and also they also depend +on s and beta the two parameters we can + + align:start position:0% +on s and beta the two parameters we can + + + align:start position:0% +on s and beta the two parameters we can +choose and we want to choose those + + align:start position:0% +choose and we want to choose those + + + align:start position:0% +choose and we want to choose those +parameters so that for for all the all + + align:start position:0% +parameters so that for for all the all + + + align:start position:0% +parameters so that for for all the all +the possible eigenvalues the larger of + + align:start position:0% +the possible eigenvalues the larger of + + + align:start position:0% +the possible eigenvalues the larger of +the two eigenvalues will be as small as + + align:start position:0% +the two eigenvalues will be as small as + + + align:start position:0% +the two eigenvalues will be as small as +possible that's it's a little bit of + + align:start position:0% +possible that's it's a little bit of + + + align:start position:0% +possible that's it's a little bit of +algebra but it's do you see that that's + + align:start position:0% +algebra but it's do you see that that's + + + align:start position:0% +algebra but it's do you see that that's +the tricky that I shouldn't say tricky + + align:start position:0% +the tricky that I shouldn't say tricky + + + align:start position:0% +the tricky that I shouldn't say tricky +because it comes out that's that this is + + align:start position:0% +because it comes out that's that this is + + + align:start position:0% +because it comes out that's that this is +the one that is a miracle in the in the + + align:start position:0% +the one that is a miracle in the in the + + + align:start position:0% +the one that is a miracle in the in the +simplicity of the solution okay and I'm + + align:start position:0% +simplicity of the solution okay and I'm + + + align:start position:0% +simplicity of the solution okay and I'm +gonna effect maybe I'll move over here + + align:start position:0% +gonna effect maybe I'll move over here + + + align:start position:0% +gonna effect maybe I'll move over here +to write the answer okay and I just want + + align:start position:0% +to write the answer okay and I just want + + + align:start position:0% +to write the answer okay and I just want +to say that miracles don't happen so + + align:start position:0% +to say that miracles don't happen so + + + align:start position:0% +to say that miracles don't happen so +often in math there's you know all of + + align:start position:0% +often in math there's you know all of + + + align:start position:0% +often in math there's you know all of +mathematics the whole point of math is + + align:start position:0% +mathematics the whole point of math is + + + align:start position:0% +mathematics the whole point of math is +to explain miracles so there is a + + align:start position:0% +to explain miracles so there is a + + + align:start position:0% +to explain miracles so there is a +there's something to explain here and I + + align:start position:0% +there's something to explain here and I + + + align:start position:0% +there's something to explain here and I +don't have my finger on it yet because + + align:start position:0% +don't have my finger on it yet because + + + align:start position:0% +don't have my finger on it yet because +anyway it happens so let me tell you + + align:start position:0% +anyway it happens so let me tell you + + + align:start position:0% +anyway it happens so let me tell you +what the right s and the right beta and + + align:start position:0% +what the right s and the right beta and + + + align:start position:0% +what the right s and the right beta and +the resulting minimum eigen value are so + + align:start position:0% +the resulting minimum eigen value are so + + + align:start position:0% +the resulting minimum eigen value are so +again they depend on little m and Big M + + align:start position:0% +again they depend on little m and Big M + + + align:start position:0% +again they depend on little m and Big M +that's a very nice feature which we + + align:start position:0% +that's a very nice feature which we + + + align:start position:0% +that's a very nice feature which we +expect and that is and they depend on + + align:start position:0% +expect and that is and they depend on + + + align:start position:0% +expect and that is and they depend on +the ratio okay so that ratio alright + + align:start position:0% +the ratio okay so that ratio alright + + + align:start position:0% +the ratio okay so that ratio alright +let's let's see it okay so the best s + + align:start position:0% + + + + align:start position:0% + +the S optimal has the formula two over + + align:start position:0% +the S optimal has the formula two over + + + align:start position:0% +the S optimal has the formula two over +square root of lambda max that's the + + align:start position:0% +square root of lambda max that's the + + + align:start position:0% +square root of lambda max that's the +square root of M and the square root of + + align:start position:0% +square root of M and the square root of + + + align:start position:0% +square root of M and the square root of +M Squared amazing okay and beta optimal + + align:start position:0% + + + + align:start position:0% + +turns out to be the square root of M + + align:start position:0% +turns out to be the square root of M + + + align:start position:0% +turns out to be the square root of M +minus the square root of little m over + + align:start position:0% +minus the square root of little m over + + + align:start position:0% +minus the square root of little m over +the square root of M plus the square + + align:start position:0% +the square root of M plus the square + + + align:start position:0% +the square root of M plus the square +root of little M all the squared of + + align:start position:0% +root of little M all the squared of + + + align:start position:0% +root of little M all the squared of +course we know what these numbers are 1 + + align:start position:0% +course we know what these numbers are 1 + + + align:start position:0% +course we know what these numbers are 1 +and beta in our model problem that's + + align:start position:0% +and beta in our model problem that's + + + align:start position:0% +and beta in our model problem that's +where I'm gonna get this square root of + + align:start position:0% +where I'm gonna get this square root of + + + align:start position:0% +where I'm gonna get this square root of +this is 1 minus the square sorry B this + + align:start position:0% +this is 1 minus the square sorry B this + + + align:start position:0% +this is 1 minus the square sorry B this +is 1 minus the square root of B in fact + + align:start position:0% +is 1 minus the square root of B in fact + + + align:start position:0% +is 1 minus the square root of B in fact +ya for our for our example well let me + + align:start position:0% +ya for our for our example well let me + + + align:start position:0% +ya for our for our example well let me +just write what they would be 2 over 1 + + align:start position:0% +just write what they would be 2 over 1 + + + align:start position:0% +just write what they would be 2 over 1 +plus square root of B Square and 1 minus + + align:start position:0% +plus square root of B Square and 1 minus + + + align:start position:0% +plus square root of B Square and 1 minus +would be over 1 plus square you see + + align:start position:0% +would be over 1 plus square you see + + + align:start position:0% +would be over 1 plus square you see +where this is 1 minus square root of B + + align:start position:0% +where this is 1 minus square root of B + + + align:start position:0% +where this is 1 minus square root of B +as a beginning to appear now it appears + + align:start position:0% +as a beginning to appear now it appears + + + align:start position:0% +as a beginning to appear now it appears +in the solution of this problem and then + + align:start position:0% +in the solution of this problem and then + + + align:start position:0% +in the solution of this problem and then +I have to tell you what the what how + + align:start position:0% +I have to tell you what the what how + + + align:start position:0% +I have to tell you what the what how +small did do these these optimal choices + + align:start position:0% +small did do these these optimal choices + + + align:start position:0% +small did do these these optimal choices +make the eigenvalues of our right this + + align:start position:0% +make the eigenvalues of our right this + + + align:start position:0% +make the eigenvalues of our right this +is what we're really paying attention to + + align:start position:0% +is what we're really paying attention to + + + align:start position:0% +is what we're really paying attention to +because it's the eigen values that that + + align:start position:0% +because it's the eigen values that that + + + align:start position:0% +because it's the eigen values that that +matrix tells us what happens at every + + align:start position:0% +matrix tells us what happens at every + + + align:start position:0% +matrix tells us what happens at every +step and the its eigen values have to be + + align:start position:0% +step and the its eigen values have to be + + + align:start position:0% +step and the its eigen values have to be +small to get fast convergence so how + + align:start position:0% +small to get fast convergence so how + + + align:start position:0% +small to get fast convergence so how +small are they well they involve this + + align:start position:0% + + + + align:start position:0% + +yeah so it's the number that I've seen + + align:start position:0% +yeah so it's the number that I've seen + + + align:start position:0% +yeah so it's the number that I've seen +so so in this case the ease the + + align:start position:0% +so so in this case the ease the + + + align:start position:0% +so so in this case the ease the +eigenvalues + + align:start position:0% + + + + align:start position:0% + +of our that's the iterating matrix are + + align:start position:0% +of our that's the iterating matrix are + + + align:start position:0% +of our that's the iterating matrix are +below that now we're now you're gonna + + align:start position:0% +below that now we're now you're gonna + + + align:start position:0% +below that now we're now you're gonna +see that one - were to be over 1 plus + + align:start position:0% +see that one - were to be over 1 plus + + + align:start position:0% +see that one - were to be over 1 plus +we're to be I think maybe squared let me + + align:start position:0% +we're to be I think maybe squared let me + + + align:start position:0% +we're to be I think maybe squared let me +just see yeah yeah it happens to come + + align:start position:0% +just see yeah yeah it happens to come + + + align:start position:0% +just see yeah yeah it happens to come +out that number again so that's the + + align:start position:0% +out that number again so that's the + + + align:start position:0% +out that number again so that's the +conclusion that was the right choice of + + align:start position:0% +conclusion that was the right choice of + + + align:start position:0% +conclusion that was the right choice of +s and beta by adding this look-back term + + align:start position:0% +s and beta by adding this look-back term + + + align:start position:0% +s and beta by adding this look-back term +look back one step you get this + + align:start position:0% +look back one step you get this + + + align:start position:0% +look back one step you get this +improvement and it's it happens you see + + align:start position:0% +improvement and it's it happens you see + + + align:start position:0% +improvement and it's it happens you see +it in practice of course you'll see it + + align:start position:0% +it in practice of course you'll see it + + + align:start position:0% +it in practice of course you'll see it +exactly and so you you do the job to use + + align:start position:0% +exactly and so you you do the job to use + + + align:start position:0% +exactly and so you you do the job to use +momentum now I'm going to mention what + + align:start position:0% +momentum now I'm going to mention what + + + align:start position:0% +momentum now I'm going to mention what +the Nesterov Nesterov had a slightly + + align:start position:0% +the Nesterov Nesterov had a slightly + + + align:start position:0% +the Nesterov Nesterov had a slightly +different way to do it and i'll tell you + + align:start position:0% +different way to do it and i'll tell you + + + align:start position:0% +different way to do it and i'll tell you +what that is but it's the same idea get + + align:start position:0% +what that is but it's the same idea get + + + align:start position:0% +what that is but it's the same idea get +a second thing so let's see if I can + + align:start position:0% +a second thing so let's see if I can + + + align:start position:0% +a second thing so let's see if I can +find that yeah nestor oh ok ok here we + + align:start position:0% +find that yeah nestor oh ok ok here we + + + align:start position:0% +find that yeah nestor oh ok ok here we +go + + align:start position:0% +go + + + align:start position:0% +go +so let me bring Nestor offs a name down + + align:start position:0% +so let me bring Nestor offs a name down + + + align:start position:0% +so let me bring Nestor offs a name down +so that that's the basically what I + + align:start position:0% +so that that's the basically what I + + + align:start position:0% +so that that's the basically what I +wanted to say about number one and when + + align:start position:0% +wanted to say about number one and when + + + align:start position:0% +wanted to say about number one and when +you've seen this trough you'll see that + + align:start position:0% +you've seen this trough you'll see that + + + align:start position:0% +you've seen this trough you'll see that +it's a similar idea of involving the + + align:start position:0% +it's a similar idea of involving the + + + align:start position:0% +it's a similar idea of involving the +previous time value ok there are very + + align:start position:0% +previous time value ok there are very + + + align:start position:0% +previous time value ok there are very +popular methods in use now for machine + + align:start position:0% +popular methods in use now for machine + + + align:start position:0% +popular methods in use now for machine +learning that involves by a simple + + align:start position:0% +learning that involves by a simple + + + align:start position:0% +learning that involves by a simple +formula all the previous values by by + + align:start position:0% +formula all the previous values by by + + + align:start position:0% +formula all the previous values by by +sort of just by an addition of a bunch + + align:start position:0% +sort of just by an addition of a bunch + + + align:start position:0% +sort of just by an addition of a bunch +of terms so it's really it + + align:start position:0% +of terms so it's really it + + + align:start position:0% +of terms so it's really it +so it's it goes under the names ADA ADA + + align:start position:0% +so it's it goes under the names ADA ADA + + + align:start position:0% +so it's it goes under the names ADA ADA +grad or others those of you who already + + align:start position:0% +grad or others those of you who already + + + align:start position:0% +grad or others those of you who already +know about machine learning will know + + align:start position:0% +know about machine learning will know + + + align:start position:0% +know about machine learning will know +what I'm speaking about and I'll say + + align:start position:0% +what I'm speaking about and I'll say + + + align:start position:0% +what I'm speaking about and I'll say +more about those yeah but it doesn't + + align:start position:0% +more about those yeah but it doesn't + + + align:start position:0% +more about those yeah but it doesn't +involve a separate coefficient for each + + align:start position:0% +involve a separate coefficient for each + + + align:start position:0% +involve a separate coefficient for each +previous value or that would be a + + align:start position:0% +previous value or that would be a + + + align:start position:0% +previous value or that would be a +momentous amount of work so so now I + + align:start position:0% +momentous amount of work so so now I + + + align:start position:0% +momentous amount of work so so now I +just want to tell you what Nesterov is + + align:start position:0% +just want to tell you what Nesterov is + + + align:start position:0% +just want to tell you what Nesterov is +and then we were good ok mr. roffe's + + align:start position:0% +and then we were good ok mr. roffe's + + + align:start position:0% +and then we were good ok mr. roffe's +idea let me bring that down + + align:start position:0% +idea let me bring that down + + + align:start position:0% +idea let me bring that down +shoot this up bring down because he had + + align:start position:0% +shoot this up bring down because he had + + + align:start position:0% +shoot this up bring down because he had +an idea that you might not have thought + + align:start position:0% +an idea that you might not have thought + + + align:start position:0% +an idea that you might not have thought +of somehow the momentum idea was pretty + + align:start position:0% +of somehow the momentum idea was pretty + + + align:start position:0% +of somehow the momentum idea was pretty +natural to use that previous value and + + align:start position:0% +natural to use that previous value and + + + align:start position:0% +natural to use that previous value and +actually I would like to know what + + align:start position:0% +actually I would like to know what + + + align:start position:0% +actually I would like to know what +happens if you use two previous values + + align:start position:0% +happens if you use two previous values + + + align:start position:0% +happens if you use two previous values +or three previous values can you then + + align:start position:0% +or three previous values can you then + + + align:start position:0% +or three previous values can you then +get improvements on this this + + align:start position:0% +get improvements on this this + + + align:start position:0% +get improvements on this this +convergence rate by going back two steps + + align:start position:0% +convergence rate by going back two steps + + + align:start position:0% +convergence rate by going back two steps +or three steps if I use the analogy with + + align:start position:0% +or three steps if I use the analogy with + + + align:start position:0% +or three steps if I use the analogy with +ordinary differential equations maybe + + align:start position:0% +ordinary differential equations maybe + + + align:start position:0% +ordinary differential equations maybe +you know so right so so there are + + align:start position:0% +you know so right so so there are + + + align:start position:0% +you know so right so so there are +backward difference formulas do you know + + align:start position:0% +backward difference formulas do you know + + + align:start position:0% +backward difference formulas do you know +about those four those would be in + + align:start position:0% +about those four those would be in + + + align:start position:0% +about those four those would be in +MATLAB software and all other software + + align:start position:0% +MATLAB software and all other software + + + align:start position:0% +MATLAB software and all other software +backward differences so maybe you go + + align:start position:0% +backward differences so maybe you go + + + align:start position:0% +backward differences so maybe you go +back two steps or four steps if you're + + align:start position:0% +back two steps or four steps if you're + + + align:start position:0% +back two steps or four steps if you're +doing planetary calculations if you're + + align:start position:0% +doing planetary calculations if you're + + + align:start position:0% +doing planetary calculations if you're +an astronomer you go back maybe seven or + + align:start position:0% +an astronomer you go back maybe seven or + + + align:start position:0% +an astronomer you go back maybe seven or +eight steps to get super high accuracy + + align:start position:0% +eight steps to get super high accuracy + + + align:start position:0% +eight steps to get super high accuracy +so that doesn't seem to have happened + + align:start position:0% +so that doesn't seem to have happened + + + align:start position:0% +so that doesn't seem to have happened +yet but it should happen here to go back + + align:start position:0% +yet but it should happen here to go back + + + align:start position:0% +yet but it should happen here to go back +more but but Nesterov will has it has + + align:start position:0% +more but but Nesterov will has it has + + + align:start position:0% +more but but Nesterov will has it has +this different way to go back so his + + align:start position:0% +this different way to go back so his + + + align:start position:0% +this different way to go back so his +formula is XK plus one the new way + + align:start position:0% +formula is XK plus one the new way + + + align:start position:0% +formula is XK plus one the new way +is YK so he's introducing something a + + align:start position:0% +is YK so he's introducing something a + + + align:start position:0% +is YK so he's introducing something a +little different - s radiant f @ YK I'm + + align:start position:0% +little different - s radiant f @ YK I'm + + + align:start position:0% +little different - s radiant f @ YK I'm +a little surprised about that YK but + + align:start position:0% +a little surprised about that YK but + + + align:start position:0% +a little surprised about that YK but +this is the point here that the gradient + + align:start position:0% +this is the point here that the gradient + + + align:start position:0% +this is the point here that the gradient +is being evaluated at some different + + align:start position:0% +is being evaluated at some different + + + align:start position:0% +is being evaluated at some different +point and then he has to give a formula + + align:start position:0% +point and then he has to give a formula + + + align:start position:0% +point and then he has to give a formula +for that for those to track those wise + + align:start position:0% +for that for those to track those wise + + + align:start position:0% +for that for those to track those wise +so the Y's are like the X's but they're + + align:start position:0% +so the Y's are like the X's but they're + + + align:start position:0% +so the Y's are like the X's but they're +shifted a little bit by some term and + + align:start position:0% +shifted a little bit by some term and + + + align:start position:0% +shifted a little bit by some term and +beta would be fine Oh No yeah beta have + + align:start position:0% +beta would be fine Oh No yeah beta have + + + align:start position:0% +beta would be fine Oh No yeah beta have +we got Nesterov here yes mister off has + + align:start position:0% +we got Nesterov here yes mister off has + + + align:start position:0% +we got Nesterov here yes mister off has +a factor gamma in yeah so I all right + + align:start position:0% +a factor gamma in yeah so I all right + + + align:start position:0% +a factor gamma in yeah so I all right +let me let me try to get this right okay + + align:start position:0% +let me let me try to get this right okay + + + align:start position:0% +let me let me try to get this right okay +all right on the previous line I've + + align:start position:0% +all right on the previous line I've + + + align:start position:0% +all right on the previous line I've +written the whole nestdrop thing here + + align:start position:0% +written the whole nestdrop thing here + + + align:start position:0% +written the whole nestdrop thing here +let's see nice drop completely and then + + align:start position:0% +let's see nice drop completely and then + + + align:start position:0% +let's see nice drop completely and then +they'll break then this is the step that + + align:start position:0% +they'll break then this is the step that + + + align:start position:0% +they'll break then this is the step that +breaks it into two first order but + + align:start position:0% +breaks it into two first order but + + + align:start position:0% +breaks it into two first order but +you'll see the main formula here XK plus + + align:start position:0% +you'll see the main formula here XK plus + + + align:start position:0% +you'll see the main formula here XK plus +1 is XK and then a beta times XK minus + + align:start position:0% +1 is XK and then a beta times XK minus + + + align:start position:0% +1 is XK and then a beta times XK minus +XK minus 1 so that's like a momentum + + align:start position:0% +XK minus 1 so that's like a momentum + + + align:start position:0% +XK minus 1 so that's like a momentum +term and then a typical gradient but now + + align:start position:0% +term and then a typical gradient but now + + + align:start position:0% +term and then a typical gradient but now +here's Nesterov speaking up this trough + + align:start position:0% +here's Nesterov speaking up this trough + + + align:start position:0% +here's Nesterov speaking up this trough +evaluates the gradient not at XK not at + + align:start position:0% +evaluates the gradient not at XK not at + + + align:start position:0% +evaluates the gradient not at XK not at +XK minus 1 but it is home mr. Oz point + + align:start position:0% +XK minus 1 but it is home mr. Oz point + + + align:start position:0% +XK minus 1 but it is home mr. Oz point +like so this is Nesterov say my favorite + + align:start position:0% +like so this is Nesterov say my favorite + + + align:start position:0% +like so this is Nesterov say my favorite +point gamma XK minus XK minus 1 some + + align:start position:0% +point gamma XK minus XK minus 1 some + + + align:start position:0% +point gamma XK minus XK minus 1 some +point part way along that step so it so + + align:start position:0% +point part way along that step so it so + + + align:start position:0% +point part way along that step so it so +this point because gamma is going to be + + align:start position:0% +this point because gamma is going to be + + + align:start position:0% +this point because gamma is going to be +some non integer this evaluation point + + align:start position:0% +some non integer this evaluation point + + + align:start position:0% +some non integer this evaluation point +of for the gradient of F + + align:start position:0% +of for the gradient of F + + + align:start position:0% +of for the gradient of F +is a little unexpected and weird because + + align:start position:0% +is a little unexpected and weird because + + + align:start position:0% +is a little unexpected and weird because +it's not a mesh point it's somewhere + + align:start position:0% +it's not a mesh point it's somewhere + + + align:start position:0% +it's not a mesh point it's somewhere +between okay yep yep and then that so + + align:start position:0% +between okay yep yep and then that so + + + align:start position:0% +between okay yep yep and then that so +that involves XK plus 1 XK and XK minus + + align:start position:0% +that involves XK plus 1 XK and XK minus + + + align:start position:0% +that involves XK plus 1 XK and XK minus +1 so it's a second-order there's a + + align:start position:0% +1 so it's a second-order there's a + + + align:start position:0% +1 so it's a second-order there's a +second-order method here we're going to + + align:start position:0% +second-order method here we're going to + + + align:start position:0% +second-order method here we're going to +it to analyze it we're going to go + + align:start position:0% +it to analyze it we're going to go + + + align:start position:0% +it to analyze it we're going to go +through this same process of writing it + + align:start position:0% +through this same process of writing it + + + align:start position:0% +through this same process of writing it +as two first-order steps to first two + + align:start position:0% +as two first-order steps to first two + + + align:start position:0% +as two first-order steps to first two +single step to one step from k to k plus + + align:start position:0% +single step to one step from k to k plus + + + align:start position:0% +single step to one step from k to k plus +1 a a coupled one-step thing follow that + + align:start position:0% +1 a a coupled one-step thing follow that + + + align:start position:0% +1 a a coupled one-step thing follow that +same thing through and then the result + + align:start position:0% +same thing through and then the result + + + align:start position:0% +same thing through and then the result +is a same factor appears for him + + align:start position:0% +is a same factor appears for him + + + align:start position:0% +is a same factor appears for him +the same factor this is also so this the + + align:start position:0% +the same factor this is also so this the + + + align:start position:0% +the same factor this is also so this the +point is this is for momentum and + + align:start position:0% + + + + align:start position:0% + +Nesterov with with some with some + + align:start position:0% +Nesterov with with some with some + + + align:start position:0% +Nesterov with with some with some +constant difference different by some + + align:start position:0% +constant difference different by some + + + align:start position:0% +constant difference different by some +constant but the key quantity is that + + align:start position:0% +constant but the key quantity is that + + + align:start position:0% +constant but the key quantity is that +one and that appears in both so so so I + + align:start position:0% +one and that appears in both so so so I + + + align:start position:0% +one and that appears in both so so so I +don't propose of course to repeat these + + align:start position:0% +don't propose of course to repeat these + + + align:start position:0% +don't propose of course to repeat these +steps for an ester off but you see what + + align:start position:0% +steps for an ester off but you see what + + + align:start position:0% +steps for an ester off but you see what +you see what you could do you see that + + align:start position:0% +you see what you could do you see that + + + align:start position:0% +you see what you could do you see that +it involves K minus 1 K in k plus 1 you + + align:start position:0% +it involves K minus 1 K in k plus 1 you + + + align:start position:0% +it involves K minus 1 K in k plus 1 you +write it as you follow an eigen vector + + align:start position:0% +write it as you follow an eigen vector + + + align:start position:0% +write it as you follow an eigen vector +you write it as a coupled system of + + align:start position:0% +you write it as a coupled system of + + + align:start position:0% +you write it as a coupled system of +that's a one-step that has a matrix you + + align:start position:0% +that's a one-step that has a matrix you + + + align:start position:0% +that's a one-step that has a matrix you +find the matrix you find the eigen + + align:start position:0% +find the matrix you find the eigen + + + align:start position:0% +find the matrix you find the eigen +values of the matrix you make those + + align:start position:0% +values of the matrix you make those + + + align:start position:0% +values of the matrix you make those +eigenvalues as small as possible and you + + align:start position:0% +eigenvalues as small as possible and you + + + align:start position:0% +eigenvalues as small as possible and you +have optimized their coefficients in + + align:start position:0% +have optimized their coefficients in + + + align:start position:0% +have optimized their coefficients in +Nesterov ok that's that's sort of a lot + + align:start position:0% +Nesterov ok that's that's sort of a lot + + + align:start position:0% +Nesterov ok that's that's sort of a lot +of algebra that's at the heart of + + align:start position:0% +of algebra that's at the heart of + + + align:start position:0% +of algebra that's at the heart of +accelerated gradient descent and of + + align:start position:0% +accelerated gradient descent and of + + + align:start position:0% +accelerated gradient descent and of +course it's worth doing because it's a + + align:start position:0% +course it's worth doing because it's a + + + align:start position:0% +course it's worth doing because it's a +tremendous saving in the in the in the + + align:start position:0% +tremendous saving in the in the in the + + + align:start position:0% +tremendous saving in the in the in the +convergence rate ok anybody running in + + align:start position:0% +convergence rate ok anybody running in + + + align:start position:0% +convergence rate ok anybody running in +the marathon or just watching it's + + align:start position:0% +the marathon or just watching it's + + + align:start position:0% +the marathon or just watching it's +possible to run you know anyway I'll see + + align:start position:0% +possible to run you know anyway I'll see + + + align:start position:0% +possible to run you know anyway I'll see +you after the marathon next Wednesday + + align:start position:0% +you after the marathon next Wednesday + + + align:start position:0% +you after the marathon next Wednesday +and professor Boyd will also see you \ No newline at end of file diff --git a/xSQxaie_h1o.txt b/xSQxaie_h1o.txt new file mode 100644 index 0000000000000000000000000000000000000000..965867bf7f111a6633bb4bdda1cf2b2b2a68f8b9 --- /dev/null +++ b/xSQxaie_h1o.txt @@ -0,0 +1,4835 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation, or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: All right, +let's get started. + +So welcome to the next +lecture about exploiting + +buffer overflow. + +So today, what we're +going to do is, + +we're going to finish up our +discussion about baggy bounds + +and then we're going +to move on to a couple + +of other different techniques +for protecting its buffer + +overflows. + +Then we're going to talk +about the paper for today, + +which is the blind return +oriented programming. + +So if you were like me when +you first read that paper + +you kind of felt like you were +watching like a Christopher + +Nolan movie at the beginning. + +It was kind of like +mind blowing right. + +So what we're going +to do is we're + +going to actually step through +how some of these gadgets + +work right. + +And so hopefully +by the end, you'll + +be able to understand all this +sort of high tech chicanery + +that they're doing in the paper. + +So first of all, +like I said, let's + +just close up with the +baggy bounds discussions. + +Let's go through a very +simple example here. + +So let's say that we're going +to define a pointer called P. + +And let's say that +we're going to give it + +allocation size of 44. + +Let's also assume that the +slot size equals 16 bytes OK. + +So what's going to happen when +we do this malloc up here? + +So as you know, the +baggy bounds system + +is going to pad that allocation +out to the next power of two, + +right. + +So even though we've only +allocated 44 bytes here, + +we're actually going to allocate +64 bytes for this pointer + +up here. + +And so also note too, this +is the slot size is 16. + +How many bounds tables entries +are we going to create? + +Well we're going to create +the allocation size, which + +in this case 64, divided by +the slot size, which is 16. + +So in this case we'll create +four different bounds table + +entries for this +thing right here. + +Each one of those +entries is going + +to be set to the log of +the allocation size, which + +in this case is +going to be 6 right. + +Because the allocation +size is 64, OK? + +So, so far so good. + +Then we're going to define +another pointer called q + +and we're going to set +it equal to p plus 60. + +So what happens when we do this? + +Well note that +strictly speaking, + +this access is out +of bounds, right. + +Because this was only +allocated 44 bytes of memory, + +but of course the way +that baggy bounds works + +is that it will actually allow +axises that are out of bounds, + +if they stay within +that baggy bounds. + +So even though +strictly speaking, + +the programmer probably +shouldn't have done this, + +this is actually +going to be OK, right. + +We're not going to raise any +flags or anything like that. + +Now let's say that +the next thing we do + +is we need to find another +pointer, which is going to be + +set equal to q plus 16 right. + +Now this is actually going +to cause an error, right. + +Because now q is at an offset +of 60 plus 16, which equals 76. + +So this is actually 12 +bytes away from the end + +of that baggy bounds. + +OK? + +And that's actually greater +than half a slot away. + +All right, so if you remember +the baggy bounds system will + +actually throw a hard +synchronous error if you + +get beyond 1/2 a slot from +the edge of that baggy bounds. + +So this will actually +cause the program to fail. + +This will actually make it stop. + +Now let's imagine that we +didn't have this line of code + +in the program, OK. + +So we had these two, but +we don't have this one. + +So what if we instead +of doing this line, + +did something that +looks like this. + +We declare another +pointer, let's call it s, + +and we set it equal to q plus 8. + +Now in this case, +the pointer is going + +to be at 60 plus 8, which equals +68 bytes away from p, right. + +So this is only four bytes +beyond that baggy bound. + +So this will not +actually cause an error. + +Even though it is strictly +speaking, out of bounds. + +What we will do here though, +is set that high order + +bit on the pointer, right. + +So that if anyone +subsequently tries + +to dereference this +thing, it's going + +to cause a hard +fault at that point. + +And then let's say, the +final thing that we do + +is we declare another +pointer t, which + +is going to equal s minus 32. + +So what happens here +is that essentially we + +brought this pointer t, it +is now back in bounds, right. + +So what that means is that +even though this guy was out + +of bounds, now we sort of going +back to the original allocated + +region, that we originally +created up here. + +So as a result, t will not +have that high order bit step + +and so you can dereference T +and everything will be fine. + +So does this all make sense? + +This should be fairly +straightforward. + +AUDIENCE: [INAUDIBLE] +the difference + +between r and s, how +would you know that r is-- + +or how does the program know +that r is 1/2 the [INAUDIBLE]. + +PROFESSOR: So note +that, like up here, + +when we create r you +can basically interpose, + +we get an instrumented +code that's + +going to be working at all +of these pointer operations. + +So basically we can tell is that +we know where P is going to be. + +I'm sorry, we know +where q is going to be. + +And we know that q is +within those baggy bounds. + +And so when we do +this operation here, + +the instrumentation +of baggy bounds + +adds and we're able +to say, aha, well I + +know where that source +formula is coming from. + +And then if you look +at this offset here, + +you determine it's more than a +1/2 slot away from slot side. + +So basically what +you think about is + +that as we're doing +these pointer operations, + +and looking and saying is how +are you going out of bounds, + +have you gone out of +bounds, yes or no. + +At some point you're going +to have some operation that's + +going to involve a pointer +that is either in bounds + +within the baggy bounds and +then some thing over here that + +makes it go out of bounds. + +So at that moment, +right when that happens, + +that's how we know that +something chicanerous has + +arisen. + +All right so, hopefully +that should all make sense. + +And so this is very +briefly a review + +of the homework question. + +So hopefully you can understand +this and our homework question + +should be pretty +easy to understand. + +So we have a character pointer +the malloc had 256 bytes to it, + +Then we declare a +character pointer + +q, that is equal to +that pointer plus 256 + +and then we essentially try +to dereference this pointer. + +So what's going to happen? + +Well note that this is an +exact power too, right. + +So there's not actually any +bagginess in the bounds, right. + +So when we do this right here, +this makes q point to one + +pass the end of +those baggy bounds. + +So just like in this +example up here, + +this line is actually fine, +but it will cause the high bit + +to be set in q, right. + +So when you come down +here and reference it, + +then everything +blows up and it's + +time to call in your +insurance agent. + +So pretty straightforward? + +OK so, that's +basically two examples + +that you can flavor for +how baggy bounds works. + +As I mentioned in +the last lecture, + +you don't actually have to +instrument every pointer + +operation, if you can use static +code analysis to figure out + +the particular set of +pointer operations is safe. + +I'll defer further +discussion of some + +of the static +analysis [INAUDIBLE], + +but suffice it to say +that you don't always + +have to have all this bit +wise arithmetic that you + +have in some of the cases +that we've examined before. + +And so another question +that came up a lot in Piazza + +was, how does baggy bounds +ensure compatibility + +with these preexisting, +non-instrumented libraries, + +right. + +And so the Piazza idea behind +how baggy bounds does that + +is, that when baggy bounds +initializes the bounds tables, + +they set all the entries +to be that bound of 31. + +So when we read +the bounds table, + +each entry represents +2 to the power + +of that entry, the size of +that particular pointer. + +So by initializing +all those bounds + +of 31, what this allows +us to do is automatically + +assume that each pointer +from [INAUDIBLE] the code + +is going to have the +largest bound possible, 2 + +raised to the 31. + +So let me just give you a +very simple example here + +that will hopefully make +this a little clearer. + +So let's say that this +over here is the memory + +space that we lose for heap. + +This is simple example, +let's suppose that basically + +what this memory space +[INAUDIBLE] two components. + +This is the heap, that is out +by the unistrumented code. + +And then let's suppose +that down here we + +have the heat that is allocated +by the instrumented code. + +So what's baggy +bounds going to do? + +So remember, baggy bounds has +this notion of a slot size, + +right. + +So basically the +slot size is 16, + +you only have entry +for every sort + +of slot of size 16 over here. + +So basically the bounds +table in this case, + +you can think of being +set up into three + +places, sorry two places. + +So initially all of the +bounds table, all the entries + +are initialized to 2 to the +30-- or sorry, to the 31. + +But then eventually +as the instrument code + +runs it's actually going +to use the baggy bounds + +algorithm to set these +values for whatever + +should be appropriate for that +particular [INAUDIBLE], right. + +So what ends happening +is that if you + +did-- if instrumented code gets +a pointer that comes from here, + +then those baggy bounds +with each particular pointer + +will always be set to the +largest possible value, 231. + +2 to the 31, right. + +Which means that +it's going to be + +impossible for baggy +bounds, entry of the code, + +to think that you've done +an out of bound operation + +with that pointer that's +coming from this uninstrumented + +library. + +So does that make sense? + +So the idea is that +in instrumented code + +we're always going to be +doing these comparisons + +with the pointers, but if +we always set the bounds + +entries for uninstrumented +pointer code 2 to the 31, + +you can never have +a dereference error. + +OK so that's basically how we +have this nice interoperability + +between the entry of the +baggy bounds code in between + +a noninstrumented off the +shelf legacy library's. + +So putting it all together, +what does this all mean? + +So, we have this +system here which + +is nice because it doesn't make +the uninstrumented libraries + +blow up, but one problem +is that we can't detect out + +of bounds pointers +that were generated + +in the uninstrumented +code, right. + +Because we're never going to +set that high bit for example, + +if that [INAUDIBLE] +pointer gets too big, + +or gets too small or +anything like that. + +So we actually can't +provide memory safety + +for operations that take +place in uninstrumented code. + +You also can't detect when +we pass an out of bounds + +pointer from instrumented +code to uninstrumented code. + +Something insane +could happen, right. + +Because remember if you +had this out of bounds + +pulled it from the +instrumented code + +it has that high +bit set to 1, right. + +So it looks like +it's super ginormous. + +Now we know if we just kept +that code in instrumented code, + +we might clear that +flag at some point + +if it comes back in bounds. + +But if we just pass +this ginormous address + +to uninstrumented +code, then who knows, + +it may try to dereference it, +it may do something crazy. + +It may even bring that +pointer back in bounds, + +but we would never +have an opportunity + +to clear that high bit, right. + +So you can come up-- +you still may come up + +with some inter-op +issues there, even if we + +use this scheme over here. + +OK, so that's essentially how +baggy bounds works on a 32-- + +you got a question? + +AUDIENCE: Yeah, so if you +have a instrumented coding + +meets like allocated +memory, is it + +using the same malloc that the +attributing code is using, or? + +PROFESSOR: Yeah so +it's a bit subtle. + +So like in this case +here, it's like very stark + +what's going on, because there's +just two regions, one of which + +is used by each set of things. + +So it actually depends on +the if they use [INAUDIBLE] + +and stuff like that. + +You can also imagine that like +in C++ [INAUDIBLE] for example, + +you can define your +own allocator, right. + +So it kind of +depends [INAUDIBLE]. + +AUDIENCE: [INAUDIBLE] +input the same, + +how does the allocator +know whether or not + +to set 31 or [INAUDIBLE]. + +PROFESSOR: Yeah so at the +lower level, typically the way + +that these allocation +algorithms work, + +is that you call unknown +system [INAUDIBLE] or something + +like that, sort of +move a pointer up. + +So you can imagine if you have +multiple allocators, all trying + +to allocate memory, +they each have + +their own chunk of memory +they reserve for themselves + +basically, right. + +So in real life it may be +more fragmented than this, + +that's essentially on a +high level, how it works. + +OK so this was a baggy +bounds on a 32-bit system. + +So as you all know 64-bit +systems are the bees + +knees these days, so +how does baggy bounds + +work on those systems? + +Well, in those systems +you can actually + +get rid of the bounds table, +because we can actually + +store some information about +the bounds, from the pointer + +itself. + +So imagine we're going to +look at a regular pointer + +in a baggy bounds system. + +So we can use it, like this. + +So we can-- if the +pointer's in bounds, + +we can basically just set +the first 21 bits to 0. + +We can put the size +in these 5 bits here. + +And once again this is +representing the log base 2 + +at the size here. + +And then we have here, +in the remaining 38 bits, + +just the regular address bits. + +Now the reason why +this doesn't massively + +curtail the address size +of the program you use, + +is that a lot of +these high order bits, + +the operating system +and-or the hardware, + +doesn't let a application use, +for various reasons, right. + +So as it turns out, +we're not dramatically + +shrinking the amount of +[INAUDIBLE] application + +you use in the system. + +This is what a regular +pointer looks like. + +Now what happens +when we only have + +one of these out +of bounds pointers? + +Well, in a 32-bit system +all we can do basically + +is just set that high +order bit and you just + +hope that thing never got +beyond a 1/2 a slot away + +from it's base. + +But now that we have all this +extra address space here, + +you can actually put the out +of bounds offset directly + +in this pointer. + +So we can do +something like this. + +So we can have 13 bits +here for the offset, right, + +the out of bound offset. + +How far away is this out of +bounds pointer, from the place + +where it should be? + +And then once again you +can put the actual size + +of the referred object here. + +This will be 0 once again. + +And this will be the +real address base here. + +And so this may be +reminiscent to you + +of some type of fact +pointer representation, + +but there's a +couple of advantages + +here, now that we're +moving in the 64-bit world. + +So first of all, you'll note +that these tag pointers, + +these are the regular size +of a regular pointer, right. + +Pointer's are still just 64-bits +wide in both of these setups. + +So that's nice because +that means for example, + +that means and rights to +that pointer are time. + +Unlike in traditional +fat finger world, + +where you actually have +to use multiple words + +represent that fat pointer. + +So that's nice. + +And also note that we can +trivially ask these things, + +uninstrumented +code, because they + +work and are the same +size as regular pointers. + +We can put these things +in structs for example, + +and the size of those +structs won't change. + +So this is very nice if we +can work in that 64-bit world. + +So does that all make sense? + +AUDIENCE: So why are there +eight 0-bits [INAUDIBLE] + +pointer there? + +Where like the 5 size +bits previously weren't. + +PROFESSOR: So you're +talking about down here? + +AUDIENCE: Yeah, +is there a reason + +why we can't just +store a [INAUDIBLE] + +if we're like six +0-bits there and had + +more bits for the offset, +like why is the number 8? + +PROFESSOR: So I think +so in some cases + +there are certain line issues +that we have to work with. + +The [INAUDIBLE] issue is to deal +with if the bits are higher. + +I don't think, in +principle, there's + +any reason why you +couldn't read some + +of these things [INAUDIBLE]. + +Well there may be +some hard versions + +that I'm not thinking +of right now, + +but [INAUDIBLE] some of +these would have to 0 + +or otherwise the hardware's +going to cause a problem. + +Any other questions? + +OK so, next thing +are you wondering + +is, can you still +launch a buffer + +overflows in the +baggy bounds system, + +obviously because I gave +you another paper to read, + +so clearly this thing, this +doesn't solve all the problems, + +right? + +So one problem +you might run into + +is that if you have +uninstrumented code once again, + +we can't detect any problems +in uninstrumented code. + +You could also encounter +memory vulnerabilities + +that come about from the dynamic +memory allocation system. + +So if you can remember +in the lecture + +we looked at this weird +free malloc weird pointer + +thing that took place. + +Baggy bounds won't +necessarily prevent you + +from some of that stuff. + +We also discussed +last lecture, where + +the fact that code +pointers do not have bounds + +associated with them, right. + +So now you have struct that +has a buffer at the bottom, + +it has a function +pointer up top, + +if you have a buffer overflow +in to that function pointer, + +right. + +Let's say that buffer +overflow is still + +within the baggy bounds. + +So you've overridden +that function pointer. + +We would try to execute +that function pointer, + +it could be pointed +at something for, + +attack a control +piece of memory. + +OK, and bounds won't +help with that, + +because there's no bounds +associate with function + +pointers. + +And so in general, what are +the cost's of baggy bounds? + +So there are essentially four. + +So the first cost +is space, right. + +So if you're using +a fat pointer, + +obviously you've got to +make pointers bigger. + +But if you're using the baggy +bounds system that we just + +discussed, you've got to +store the bounds table, right. + +And so the bounds table +has that slot size + +which allows you to control +how big that bounds table is, + +but still you may end up using +[INAUDIBLE] memory for that. + +You've also got the CPU overhead +of doing all of the pointer + +instrumentation, right. + +So for every, or close to every +pointer thing that you do, + +you got to check these bounds +using those shift operations + +and things like that. + +So that's going to +slow your program down. + +There's also this problem +with false alarms, right. + +So as we discussed, +it may be the case + +that a program generates +out of bound pointers + +but never tries to +dereference it, right. + +Strictly speaking +that's not an issue. + +The baggy bounds will +flag the creation + +of those out of bounds +pointers, if they + +get beyond a 1/2 a slot size, +at least in the 32-bit solution, + +right. + +And so what you'll see with +a lot of security tools, + +is that false alarms really +reduce the likelihood + +that people are going to +use your tools, right. + +Because in practice +we would all hope + +that we care about +security, but actually + +what do people care about? + +They want to be able to upload +their silly Facebook photos + +and life things, +and they want to be + +able to make things go +fast and stuff like that. + +So you really want +your security tools + +to probably have less +coverage of finding bugs, + +but actually have +0 false alarms. + +As opposed to catching all types +of security vulnerabilities, + +but then maybe having +some false alarms + +that are going to irritate +developers, or irritate users. + +And the other costs that you +have for this is finally, + +is that you need +compiler support, right. + +Which can actually end +up being nontrivial, + +because you have +to go in there, you + +have to add all the +instrumentation, + +crawl the pointer checks, +and so on ans so forth. + +So those are basically the +cost of these bounds checking + +approaches. + +So that concludes the +discussion of baggy bounds. + +And so now we can actually think +about a two other mitigation + +strategies for buffer overflows. + +They're actually much simpler +to explain and understand. + +So one of these approaches is +called a non-executable memory. + +And the basic idea is +that the paging hardware + +is going to specify +3-bits for each page + +that you have in memory, read, +write and execute, right. + +Can the program read +that memory, write to it, + +execute it. + +The first 2-bits +are old, they've + +been around for a while, +that last bit is actually + +a fairly new construction. + +And so the idea is +that you can actually + +make the stack +non-executable, right. + +So if you make the +stack non-executable + +that means that the +adversary can't run code + +just by pointing-- by +creating that shell code + +and then sort of jumping to +someplace in that buffer. + +And so what a lot of systems +do, is they actually specify + +a policy like this. + +So right exclusive or x, +which means that if you have + +a particular page, you +can either write to it, + +or you can treat it +as executable code, + +but you cannot do both. + +OK and so that once +again, is going + +to prevent the +attacker from just + +putting executable +code in the stack + +and then going straight to it. + +So this is-- should be pretty +straightforward, right. + +So we've removed, at the +hardware level, this attack + +vector of the attacker putting +executable code in the stack. + +So what's nice about this? + +Well potentially this +works without any changes + +to the application, right. + +This is all taken place +at the hardware level + +and at the OS level, +with the OS just + +making sure the pages are +protected with these bits, OK. + +So that's very, +very nuts, right. + +Because you don;t have to worry +about this compiler support + +issue we had over here. + +The other nice thing +is that, as I mentioned + +in the last lecture, +the hardware's + +always watching you, even +though the OS is not, right. + +So these bits being +said over here, + +you know they're +looked at and verified + +for correctness at +every memory reference + +that you make by the code. + +That's a very nice +aspect of this too. + +Now one disadvantage +of this system + +though, is that it makes it +harder for an application + +to dynamically generate code, +in benign or benevolent cases. + +And the best example of +that is, the just-in-time + +compilers that we discussed +from last lecture, right. + +So how is it that +you can go to a web + +page and your JavaScript +code executes fast. + +It downloads that +JavaScript source, + +it initially probably +starts just interpreting it, + +but then at some +point it's going + +to find some hot +path, some hot loop + +and then it's going to +dynamically generate + +x86 machine code and execute +that directly, right. + +But to get that to work you have +to be able to dynamically write + +code to a page. + +So there's some ways you can +get around this for example, + +you could imagine that the +just-in-time compiler initially + +sets the write bit and then +it removes the write bit, + +then it sets the execute bits. + +There are some ways that +you can get around that, + +but it can be a little +bit tricky sometimes. + +On a higher level, that's how +non-executable memory works, + +pretty easy to understand. + +AUDIENCE: What is the +definition of like executable + +instructions? + +So if you change the +attenuator [INAUDIBLE] + +it's not considered a +executable instruction. + +PROFESSOR: Well basically no. + +Can you set like the instruction +pointer register to that value. + +In other words, can you-- if you +have a bunch of memory pages, + +can you actually set EIP +there and actually start + +executing code from that page. + +AUDIENCE: Ah. + +PROFESSOR: OK, so that +is nonexecutable memory. + +And so another +technique you might + +imagine for protecting +against a buffer overflows + +is using a randomized +addresses or address spaces. + +And so the observation +here is, that a lot + +of the attacks that +we've discussed so far + +use hard coded addresses, right. + +And so if you think about +a lot of the attacks + +you've been working on in +your lab, how does that work? + +You open up the program +in GDB, you find out + +the location of some things, +you may create some shell code + +that actually has some hard +coded addresses in there, + +right. + +So the idea behind the +randomized address base + +is simple. + +Basically you want to make +it difficult for the attacker + +to guess addresses. + +So there's a couple +different ways + +you could think about +doing this, right. + +So one idea is that +you can imagine having + +stack randomization, right. + +So imagine that +from here to here, + +this is the entire virtual +memory space of the program, + +right. + +As we described this +stuff to you so far, + +basically the +stack always starts + +with this particular place +up here, always goes down, + +right, and the program codes +down here and the heap always + +goes up here. + +And all these seg-- all of these +segments, the stack, the heap, + +and the program code, they all +start at a well known location. + +So imagine for example, like +if my lecture notes here + +are the stack. + +You can imagine instead of +the stack always starting here + +at this known location, +maybe you start it here, + +maybe you start it here. + +Somewhere else like that, right. + +Similarly you can imagine that +maybe the program code which + +used to always start +down here, maybe we + +start it up here, or down here, +or something like that, right. + +So the idea now is that +if you, the attacker, + +control one of these +binary's, you can look in GDB + +and figure out where +all these offsets are, + +but they're not actually +going to help you figure out + +where those offsets are +in the real code that's + +running on the server, right. + +So that's the basic idea behind +these randomized address spaces + +there. + +And so this takes +advantage of the fact + +that a lot of the code +that you generate, + +doesn't have to be loaded into +a specific place in memory, + +right. + +So unless you're writing like +a device driver, or something + +like, that maybe is interacting +with some hardware that + +requires this +particular address to be + +belong in this particular buffer +so it can copy information in. + +If you're not doing stuff +like that then typically + +your codes going +to be relocatable. + +So this approach will work very +nicely with that kind of stuff. + +So once again the question +is, can you exploit this? + +Obviously the +answer is still yes. + +There's a couple different +ways you can do it + +as we'll discuss later today +in the [INAUDIBLE] paper, + +the attacker can actually +extract randomness, right. + +And so in general that's +how you defeat all + +these randomized approaches. + +You make them unrandom, +by either finding out + +the random seed that +the attacker was doing, + +or by somehow leveraging the +fact that the attacker leaks + +information about the randomized +locations of these things. + +And another thing +that's interesting + +is that for a lot of the +attacks we've discussed so far, + +we've basically been using these +sort of hard coded addresses, + +but note that the attacker +may not necessarily + +care about jumping to +a specific address. + +Or there's this attack +called a heap attack, which + +is actually pretty hilarious if +you're a bad person, I suppose. + +So the way that this +heap attack works + +is, that the +attacker essentially + +just starts dynamically +allocating a ton of shell code + +and just stuffs it +randomly in memory, right. + +This is particularly +effective if you're + +using like a dynamically high +level language like JavaScript + +let's say. + +So the tag reader is +sitting in a tight loop + +and just generate a bunch of +shell code strings, right. + +And you just fill the heap +with all these shell code + +strings, right. + +Now the attacker maybe cannot +figure out where the exact + +location is of each of +the shell code strings, + +but if you've allocated 10s of +megabytes of shell code strings + +and then just do a +random jump, right. + +If you could somehow control +one of these ret pointers, + +then hey, maybe you'll +land in shell code, right. + +And one trick you +can actually use + +is this thing called NOP sleds, +which is also pretty hilarious. + +So imagine that if you have +a shell code string, then + +it may not work out if +you jump to a random place + +in that shell code +string, because it may not + +set the attack up correctly. + +But maybe this stuff that +your spewing to the heap, + +is basically just a ton of NOPs +and then at the very, very end + +you have the shell code, right. + +This is actually +quite clever right, + +because this means that now +you can actually goof up + +the exact place where you jump. + +If you jump into +another one of these NOP + +things just go boom, boom, boom, +boom, boom, boom, boom, then + +you hit the shell code, right. + +So it's like these are the +people that you probably + +see on the team. + +They're inventing these +types of things, right. + +This is a problem. + +So that's another way +to get around some + +of this randomization +stuff, just + +by making your codes +randomization resilient, + +if that makes sense. + +OK so that's basically +a discussion of some + +of the types of +randomness you can use. + +There's also some wacky ideas +that people have had too. + +So now you know +that when you want + +to make a system +call for example, + +you use this syscall +libc function + +and you basically pass +any unique number that + +represents the system call +that you want to make, right. + +So maybe four is seven and maybe +sleep is eight, or something + +like that, right. + +So what that means is that +if the attacker can somehow + +figure out the address of +that syscall instruction + +and jump to it somehow, he or +she can actually just supply + +the system call number that they +want to invoke directly, right. + +So you could imagine that +each time the program runs, + +you actually create a dynamic +assignment of syscall numbers + +to actual syscalls, right. + +To make it harder for the +attacker to get stuff. + +There's even some very +avant garde proposals + +to change the hardware such +that the hardware actually + +contains an xor key, that +is used to dynamically xor + +instructions, right. + +Imagine every time you +compile the program, all + +of the instruction codes that's +the xor of some key, right. + +That key is put into +that hardware register + +when you initially +load the program + +and then whenever you +execute an instruction, + +the hardware +automatically xor's it, + +before you continue executing +that instruction, right. + +So what's nice about +that is, that now even + +if the attacker can +generate the shell code, + +the attacker doesn't +know that key, right. + +So it's very difficult +for the attacker + +to figure out what exactly +to put into memory. + +AUDIENCE: But if +he can get the code + +and he also instructions +he can xor it back + +to the instruction [INAUDIBLE]. + +PROFESSOR;Oh yeah. + +This is always a +canonical problem, right. + +So it's like what if +someone does this? + +So that's exactly right. + +So this is somewhat similar to +what happens in the BROP attack + +where, essentially we've sort of +randomized where locations are, + +but the attacker can +do probes, right. + +And figure out what's going on. + +So you can imagine too that for +example, if the attacker knows + +some sub-sequence of +code that he's expects + +to be in the binary, +you could imagine + +just sort of trying to xor the +binary with that known code, + +trying to extract the key. + +And there's a lot +evil in the world, + +so you're exactly +correct about that. + +OK so that's essentially +the discussion + +of all the randomization attacks +that I want to discuss today. + +So one thing to +talk about before we + +get to some of the return +oriented programming stuff, + +is you might wonder which +ones of these defenses + +are actually used in practice. + +And so as it turns out, +both GCC and Visual Studio, + +they both enable stack +canaries by default, right. + +So that's very popular, that's +a very well known community. + +If you look Linux +and Windows they + +can also do things like +non-executable memory. + +They can also do things like +randomize the address space, so + +that's also [INAUDIBLE]. + +The baggy bounds stuff +however, is not as popular. + +And that's because of +some of these costs + +that we talked about +over here, in terms + +of memory overhead, CPU, the +false alarms, and so on ans + +so forth. + +So that's basically a survey +of the state of the art, + +in trying to prevent +these buffer overflows. + +So now we're going to talk about +this return oriented programing + +stuff. + +So what I'm described to +you so far today in terms + +of the address space +randomization and the data + +execution prevention, +that's the-- the + +read, write and execute +that I just described. + +Those things are actually +very, very powerful, right. + +Because the randomization +prevents the attacker + +from actually understanding +where our hard coded addresses + +are. + +And the data +execution prevention + +says, even if you can put +shell code into the stack, + +then the attacker +can't just jump to it + +and execute it, right. + +So at its space, +that seems like, + +man you've really +made a lot of progress + +for stopping these attackers, +but of course there + +are these hackers out there who +spend all their time thinking + +about how to ruin our lives. + +So what's the insight behind +return oriented programming? + +The insight is that, what +if instead of the attacker + +being able to generate just +new code at attack time, what + +if the attacker could +string together preexisting + +pieces of code and then string +them together in deviant ways, + +right? + +And we know that the program +contains a ton of code already, + +right. + +So hopefully, or unhopefully, +depending on which side of this + +you're on. + +If you can find enough +interesting code snippets, + +you can string them +together to basically form + +like this Turing +complete language, where + +the attacker can essentially +do whatever the attacker wants + +to do. + +So that's the insight behind +return oriented programming. + +So understand how this works. + +Let's look at a very simple +example that will initially + +start off very familiar, right. + +But then it's very quickly +going to descend into madness. + +So let's say that we have +the following program. + +So we have some program-- sorry, +some function and conveniently + +for the attacker, it has this +nice function here called + +run shell. + +So this is just +going to call system, + +it's going to execute bin +slash bash and then be done. + +And then we've got the canonical +buffer overflow process + +or sorry, function down +here, basically this thing + +is going to declare a +buffer, and then it's + +going to use one of +these unsafe functions + +to fill in bytes in the buffer. + +OK so, we know that this +can be overflowing OK, + +this is old news. + +Now what's interesting is that +we have this function up here, + +run shell, but it +doesn't quite seem + +to be accessed in some direct +way based on this buffer + +overflow. + +So how can the attacker invoke +this run shell command here? + +Well the attack may +do a couple things. + +So first of all, the attacker +can disassemble the program, + +run GDB, find out the address +of this thing in the executable, + +right. + +So you all should be very +familiar with doing those kinds + +of things through the lab. + +That's the first thing +the attacker can do. + +And then during the +buffer overflow, + +the attacker can essentially +take that address, + +put it in the buffer +overflow that's generated + +and make sure that the +function returns to run shell. + +So just to make that clear, +let's draw that over here. + +So, you have a setup +that looks something + +like this at the bottom, +we have the buffer, + +that's being overflowed. + +And then up here, we have +the save the break pointer, + +up here we have the return +address, for process message. + +So remember that the new stack +pointer will be here initially, + +when we start +executing the function. + +This is the new +break pointer, this + +is what the stack +pointer used to be. + +And then we've got some +break pointer up here, + +for the previous frame. + +OK, so this should +look pretty familiar. + +So basically, in the +attack, like I said, + +we've used GDB to +figure out what + +the address is of run shell. + +So in the buffer overflow, +we can essentially just + +put the address of run +shell right here, right. + +So this is a actually pretty +straightforward extension + +of what we already +know how to do, right. + +So basically it's saying, +if we conveniently + +have a command +that runs a shell, + +if we can disassemble +the binary, figure out + +where that address is, we can +just put that in this overflow + +array that we have here. + +So that should be +pretty straightforward. + +Does that make sense? + +OK. + +So, this was a very +childish example, + +because the programmer +for some crazy reason + +has put this low +hanging fruit here. + +So as an attacker this is like +Christmas coming early, right. + +Now it may not be the case +that you have something + +as delightful as this. + +So what you could have instead, +is something like this. + +So let's say that instead +of this thing being called + +run shell, we call it +run boring and then + +maybe this thing just executes +bin slash OS let's say. + +But let's say that everything +is not completely lost, + +because we actually +have a string up here + +that conveniently gives +us the path of that. + +So what's interesting about +this is, that we can disassemble + +the program, find the +location of run boring, + +but as an attacker, +who wants to run an OS? + +Right, that's no fun +But we do actually + +have a string in memory that +points to the path of the shell + +and actually we also know +something interesting too. + +Which is that even though the +program isn't calling system + +with the argument that we want, +it is calling system somehow. + +So we know that +system must be getting + +linked into this +program somehow, right. + +So we can actually +leverage those two things, + +to actually call system +with this argument here. + +So the first thing that we +do, is we can go into GDB + +and we can actually +figure out where + +this thing is located in the +process binary image, right. + +So you just go to GDB, just +type in basically print system + +and I'll give you +some information + +about the offset of that OK. + +So that's pretty +straightforward. + +You can also do the same +thing with bash path. + +Right, you just use +GDB to figure out + +where this thing lives. + +It's statically +declared string, right. + +So you'd be able to find +out where that lives. + +And so once you've +done that, now you + +got to do something a +little bit different, right. + +Because now we actually +have to figure out somehow, + +how to invoke system with +an argument of our choosing, + +right. + +And so the way that we do +that is by essentially faking + +a calling frame for system. + +OK, so remember that +a frame is the thing + +that the compiler +and the hardware + +work together to use to +implement the call stack, + +right. + +So here's basically +what we want to do. + +We want to set up something +like this on the stack, right. + +So basically we're +going to fake what + +system would expect +to be on the stack, + +but right before it +actually executes its code. + +So up here we had the +argument of the system, + +this is the string that we +actually want to execute. + +And then down here, this is +where system should return to, + +when it's done. + +Right, so this is what system +expects the stack to look like, + +right before it +starts execution. + +It's going to say this is where +I should go when I'm finished, + +this is the thing I should +consume as my argument, right. + +In the past we've been +assuming that there + +were no arguments when +you pass the functions, + +but now this is a little +bit different, right. + +So basically we +just have to ensure + +that this thing is in that +overflow code that we create, + +right. + +We just have to make +sure this fake calling + +frame is in that array. + +So basically the +way this will work + +is, we will do the following. + +So once again remember +the overflow goes up here. + +So first, we're going to put +the address of system here. + +And then here, we're going +to put just some junk return + +address. + +Right, this is +where system's going + +to return after it's finished. + +For the purposes +of the discussion + +now, we don't care +what this does, + +we'll just make this be just +some random set of bytes. + +And then up here, +we're actually going + +to put the address +of bash path, right. + +So what's going +to happen now when + +we do this buffer in overflow? + +So what's going to happen is +that, process message is going + +to finish, it's +going to say, OK hey, + +here's where I should +return to, right. + +And then it's going to +pop the stack, right, + +and now the system code +is executing, right. + +The system code now sees +that fake call frame + +that we created, right. + +As far as system is +concerned, nothing chicanerous + +has taken place, right. + +System will say, aha +here's the argument + +that I want to execute, +it's bin slash bash, + +it's going to execute it +and voila, the attacker + +has a shell, right. + +So does this make sense? + +So basically what we've +done is, we've now + +taken advantage of knowledge +of the calling convention, + +for the platform to +create fake stack frames, + +or fake calling +frames I should say. + +And using those +fake calling frames, + +we can actually execute any +function that is already linked + +and defined in the application. + +Does that make sense? + +OK so, another question +you might have is, + +what if this string wasn't +actually in the program? + +Now to be clear, this +string is almost certainly + +in the program. + +So that's one funny +thing about security, + +there's just all kinds of fun +strings that are laying around, + +you can just go to +town all day long. + +Well let's suppose we +live in bizarro world + +and like this string +is not in the program. + +So does anyone have +any ideas about what + +we could do to get that +string to be in the program? + +AUDIENCE: We can put the +string on the [INAUDIBLE]. + +PROFESSOR; Yes exactly, +don't trust that man. + +That's what you can do, exactly. + +So, what you can do +is actually for here, + +have the address of bash path, +actually point here, right. + +And then you'd put-- up here +you would put slash B-I-N + +slash P-A-T slash 0. + +So that's how you +can get around-- I + +think I got that math right, +because each one of these + +is 4 bytes. + +But anyway, so you have the +pointer go up here and then + +boom, you're done. + +So now you can actually +conjure up arguments + +just by putting them +in the shell code. + +Pretty horrifying. + +So this is all building up +towards the full BROP attack, + +right. + +But before you can mention +the full BROP attack, + +you've got to +understand how you just + +chain together these +preexisting things in the code. + +So one thing to note is that +when I'm setting up this return + +address here, I just said, +eh just put some junk here, + +it doesn't really matter, +we just want to get a shell. + +But if you're the attacker, +you could actually + +set this return +address to something + +that's actually useful, right. + +And if you did that, you +could actually string together + +several functions, several +function indications in a row, + +right. + +That's actually very, +very powerful, right. + +Because in particular, +if we literally just + +set this return +address to jump, I + +mean it may be that +when we ret from it, + +like the program crashes on +it, maybe we don't want that, + +right. + +So can actually start +chaining some of these things + +to do interesting stuff. + +So let's say that our goal is +that we want to call system + +an arbitrary number of times. + +We don't just want +to do it one time, + +we're going to it a +arbitrary number of times. + +So how can we do that? + +Well, we're going to use +two pieces of information + +that we already know +how to get, right. + +We already know how to get +the address of system, right. + +We just look in GDB and find it. + +We also know how to find +the address of that string, + +bin flash bash. + +Now to actually make this +attack work using multiple calls + +to system, we're going to +have to use gadgets, right. + +This is getting us +closer to what's + +taking place in the BROP paper. + +So what we need to do +now, is find the address + +of these two Op codes. + +Right, so what is this, so this +is pop in EAX, so what does + +this do? + +This just takes the +top of the stack + +and then it puts it +into the EAX register. + +And what is the ret +instruction going to do? + +It just pops the +top of the stack + +and then puts it into +EIP, instruction pointer. + +OK, so this is what's +known as a gadget, right. + +This is like a small set +of assembly instructions + +that the attacker can use +to build these larger more + +grandiose attacks. + +OK, So how can we find +this gadget, right. + +There's actually like +some off the shelf tools + +that hackers use to +find these things, + +it's not hard to get +the binary, right. + +Essentially just +do a [INAUDIBLE] + +for these types +of things, right. + +So it's just as easy to +find one of these gadgets, + +assuming that you've +got a copy of the binary + +and we're not worried +about randomization yet. + +It's very easy to +find these things. + +Just like it's very easy to find +the address of system and stuff + +like that. + +So if we've got one +of these gadgets, + +what can we use +this gadget to do? + +Well of course the +answer is evil. + +So, what we can do +is the following. + +Let's say that we +changed the stack + +so that it looks like this. + +So the exploit goes this way. + +And so let's say, we do this. + +So the first thing +we're going to put here + +is the address of system. + +And the thing we're +going to put up here, + +is the address of +the pop ret gadget. + +Then up here, we're going to +put the address of bash path + +and then we're going +to repeat this pattern. + +So we're going to put +the address of system, + +the address of the +pop ret gadget, + +and then the address +of bash path. + +OK, so what's going +to happen here now? + +Now this is going +to be a bit tricky, + +and these lecture +notes are going + +to be up on the +web, so you may just + +want to listen to +what's happening, + +but this-- when I first +understood this, this + +was like understanding that +Santa Claus wasn't real right. + +So what will happen +is-- and by the way, + +Santa Claus isn't real, I hope +I didn't ruin it for everyone. + +So what's going to happen? + +So [INAUDIBLE] is what +puts this in memory. + +So we're going to +start here, OK. + +So what's going to happen? + +We're going to return to +system, the ret instruction + +is going to pop an +entry off the stack, now + +the top of the +stack pointers here. + +OK, so system is going to +find its argument here, + +it's going to execute the shell. + +Then it's going to finish +and return to whatever's + +here, which is the pop gadget. + +In executing that +return, we change + +the top of the stack +pointer to be here. + +OK, now we are in +the pop ret gadget. + +OK, so what is that pop +ret gadget going to do? + +It's going to pop what's on +the stack, which is this, OK. + +So now the top of +the stack is here. + +Then we're now in +the ret instruction + +from the pop ret gadget. + +What's this going to do? + +Aha, it's going to call +system again, right. + +So once again the ret is going +to pop this off this stack, + +we are now in system. + +Top of the stack +is here, system is + +going-- this will trigger +calling frame, the system. + +System takes the bash +path argument here. + +OK, and then it is +going to ret, right. + +Where's it going to ret to? + +The pop ret gadget again. + +So the ret pops +the stack, we are + +now in the pop ret gadget, +the ret gadget-- sorry, + +the pop ret gadget is going to +pop this, so on and so forth. + +OK? + +So clearly we can +chain this sequence + +to execute an arbitrary +number of things, right. + +And so this in +essence is starting + +to get to the core of what +return oriented programming is. + +Note that we have not executed +anything in the stack, right. + +This is what has allowed us to +get beyond those data execution + +prevention bits, right. + +Nothing's been executed here. + +We're just sort of jumping +to things in unexpected ways + +to do what we want to do. + +OK so this is actually +very, very, very, clever. + +And so what's interesting +is that at a high level + +you can think about us, we've +now defined this new model + +for computation, right. + +So in a traditional, +non-malicious program, + +you have the +instruction pointer that + +points to some linear +sequence of instructions. + +And you increment the +instruction pointer + +to figure out what's +the next thing to do. + +In essence, what return +oriented programing does is, + +it uses the stack pointer +as the instruction pointer. + +Right, so as we move +the stack pointer, + +we're pointing to like +other blocks of code + +that we're going to execute. + +And then at the +end of the gadget, + +you return back to +the stack pointer + +which is then going to tell +us the next block of code + +to execute. + +OK so that does that make sense? + +So that's basically how you +can avoid the data execution + +prevention stuff. + +That's how you can +get around having + +this no execute bit on pages. + +So the next thing that +we might want to do + +is defeat stack canaries. + +So if you remember, this +canary was this value + +that we were going to +place on the stack, right. + +So you can imagine +the canary would + +go right here for +example, or right here, + +and it would prevent someone +from overriding the return + +address, without also +overwriting the canary. + +With the intuition being that +before the system actually + +jumps to the ret +address, it can check + +to see if the canary +has been changed + +in a way that's incorrect. + +So that's how the +canary works, but can we + +get around the canary? + +Can we guess the canary somehow? + +Well we can actually, if +we make a few assumptions + +about how the system works. + +So, how do we defeat +those canaries? + +So the first thing that we want +to assume is, that the server, + +it has to have a buffer +overflow vulnerability. + +The second thing that +we're going to assume, + +is that the server is going +to crash and respond, just + +restart, if we set the +canary value to a bad one. + +And the third thing that +we're going to assume + +is that, after the restart, +that the canary and any address + +space randomization that you're +doing, is not rerandomized. + +Right, so what that +means is that, we're + +going to assume that if we can +somehow crash the server, then + +when the server restarts, +it's going to have + +the same value for the canary. + +And it's going to have the same +locations for all the quote + +unquote "randomized" stack, +heap and code information + +that it has. + +So you might wonder why +would this be the case? + +Why would it be that when +the server comes back + +it doesn't have new +locations for things? + +The reason is because +a lot of servers + +are written to use fork, +to create new processes. + +And if you remember, +fork actually + +inherits-- the child +inherits the address + +space of the address space +layout right of the parent, + +right. + +This is copy on write pages +that change stuff as the child + +updates things, but +if you use fork here, + +instead of execing +a whole new process, + +any time that parent server +process forms new children, + +those children will have the +same values of the canary + +in the address base, OK. + +So these are the +assumptions that we're + +going to make to try to +defeat these canaries here. + +So how can we defeat the canary? + +Well the attack is actually +fairly straightforward. + +So imagine that the stack +is going up this way, right. + +Imagine you got the +buffer overflow here, + +then imagine that the +canary is up here, right. + +And the canary actually +has multiple bytes, right. + +So what you can +actually do is, you + +can probe those bytes one by +one and start guessing values + +of what those bytes are, right. + +So let's say that-- so the +canary looks like this. + +Here's the overflowing +buffer, and you want + +to guess what these bytes are. + +So the first thing +that you guess + +is you take your overflow, +just to this first byte + +of the canary and you +say, hey, is that byte 0? + +You write a 0 there, +with your overflow. + +You're either correct +or you're incorrect. + +If you are incorrect, then the +server's going to crash, right. + +If you are correct you +say, aha I actually + +know the first byte of +the canary now, right. + +Then you start guessing here. + +You say, are you 0? + +Probably not, it's +going to crash. + +Are you one? + +And maybe not, it's +going to crash. + +Are you two? + +Aha, it doesn't crash, right. + +So now you've actually found +the value of that second canary + +byte, right. + +As you can imagine, +you step up this way, + +and you eventually find all +the values for the canary. + +So once again we're taking +advantage of the fact, + +that crashes are a signal +to you, the attacker, + +that you've actually done +something wrong, right. + +And the server is staying +up, in other words, + +that socket connection's +staying open, is + +a signal to you, the +attacker, that you've + +done something right. + +AUDIENCE: Maybe I mentioned +something basic here + +like why do you-- if you +know how long the canary is, + +can you just infect directly? + +Skip that buffer +and overflow those-- + +the one path there the canary? + +So like [INAUDIBLE] say you can +like [INAUDIBLE] the canary-- + +PROFESSOR: Yeah, yeah you +can't-- so that's right + +if you-- so if you in fact +know the exact location + +of the canary, right. + +That can sometimes +allow you to skip + +some of these attacks totally. + +Because then you +can just directly + +write to the return +address, let's say, + +as opposed to doing some of +this buffer overflow nonsense. + +But in general, if there's +some level of randomization + +here, if you don't quite know +where the stack is for example, + +then it's tricky +to do that, right. + +So basically the way +that the attack proceeds + +is that you don't quite +know what's happening, + +and so you just very slowly +creep your way up memory, + +down the stack, to figure +out where these things are. + +AUDIENCE: Can the +server instead of + +crashing when it +finds strong canaries, + +keep the socket open and +[INAUDIBLE] deprocess + +and [INAUDIBLE]? + +PROFESSOR: Yeah, so we'll +discuss at the end of lecture + +some of the defenses you +can have against this, + +but one very, abstractly +speaking civil defense, + +is that when the +program crashes, + +you catch the segfault +using a signal handler, + +do not deduce you're +own code by the way. + +But you can do this, right. + +You catch that segfault +and then the signal handler + +just keeps that +process alive for a bit + +and that will trick the +attack into thinking that, + +oh I won't get that signal +back, in other words. + +OK so that's +basically how you can + +guess the value for the canary. + +And note that you can +actually use this attack + +to sort of figure out +arbitrary values that + +are low in the stack, right. + +Just by iteratively guessing +for each byte what it is, + +and then using that +crash indication + +as a signal of whether you're +guess was correct or not. + +So that's basically +how you can defeat + +these randomized +canaries, assuming + +that after the server restarts, +those things are not changed. + +And so we've also +shown how you can + +use the gadgets +to string together + +these more elaborate attacks. + +So what we're going +to look at next + +is a way that you can use all +these techniques to defeat + +data execution prevention, +address-based randomization + +and canaries on a +production system. + +Now what we're +going to do now is, + +we're actually going +to start looking + +at 64-bit architectures instead +of 32-bit architectures. + +As it turns out for +randomization purposes, + +64-bit architectures +actually give you + +a lot more randomness to protect +yourself against the attacker. + +So looking at attacks +is much more interesting + +on those systems. + +So that's also the type +of architecture that's + +discussed in the BROP paper. + +They talk about 64-bit machines. + +So from now on, +assume that we're + +going to talk about the +64-bit architectures. + +For the purposes +of this discussion, + +the only difference +between a 32-bit machine + +and a 64-bit machine, is +that on a 32-bit machine, + +the arguments are passed +on the stack, right. + +So here for example, this +is like a 32-bit machine + +we were assuming, so +for example, bash path + +will pass on the stack. + +On a 64-bit machine, +the arguments + +are passed in registers instead. + +OK so like when a +function starts execution, + +it's going to look +in certain registers + +to find where the arguments are. + +OK, make sense? + +All right. + +So start up here. + +All right, so now we get to +the point of today's paper. + +Which is the blind return +oriented programming. + +So what's the first +thing you want to do, + +if you want to engage in +BROP for fun or profit? + +So the first thing +you have to do + +is, you have to find what +they call a stop gadget. + +Now a stop gadget-- and remember +that when we say gadget, + +we essentially mean, +return addresses, right. + +A gadget is identified +by the return address, + +by the start address of that +sequence of instructions + +that we want to jump to, right. + +So what is a stop gadget? + +So a stop gadget is +essentially a return address + +to someplace in the code, +but if you jump to it, + +you're going to +pause the program, + +but you're not +going to crash it. + +OK, so that's why it's +called a stop gadget. + +Now what might that +stop gadget be? + +You might jump to someplace +in the code that then calls + +via the sleep system call +for example, or does pause, + +or something like that. + +Or maybe somehow the program +gets stuck in an infinite loop + +if you jump to that place. + +Doesn't really matter +why the stop's happening, + +but you could imagine +several scenarios which would + +cause that stop to take place. + +So why is this useful? + +Well once the +attacker has managed + +to defeat the canaries using +that iterative guessing + +technique I showed +you, he can start + +to overwrite this return +address and start probing + +for these stop gadgets, right. + +And so note that +most of the random + +addresses you might +put there, they'll + +probably crash +the server, right. + +Once again, that's the +message to you, the attacker, + +that's an indication that what +you found is not a stop gadget, + +right. + +Because when the server +crashes your sockets-- + +your socket +connection is closed. + +You as an attacker +know, OK that must not + +have been a stop gadget. + +Where if you guess something +and then you-- that socket still + +stays open for +awhile, you think, + +aha I found that stop gadget. + +So that's the basic +idea behind step one. + +You got to find +that stop gadget. + +Now step two, is +that you want to find + +gadgets that pop stack entries. + +And so you basically have to +use this sequence of carefully + +crafted instructions +to figure out + +when we've got one of +these stack gadgets. + +So this sequence +is going to consist + +of a probe address, a stop +address, and a crash address. + +So the probe +address is the thing + +that we're going to +put in the stack. + +This is going to be the address +of a potential stack popping + +gadget. + +This stop gadget is going to +be what we found in step one. + +So this is an address +of the stop gadget. + +And then the crash +gadget is just + +going to be the address +of nonexecutable code. + +So for example, you +could just set this + +to, just the +address zero, right. + +If you do a ret to this and +then try to execute code there, + +this is going to +crash your program. + +So we can basically use +these types of addresses + +to find out where these +stack popping gadgets are. + +So here's a simple example. + +So let's write this over here. + +So let's say we have these two +different examples of a probe, + +a trap, and then a stop, right. + +So let's assume that +we have down here, + +we're going to probe +at some address, + +doesn't really matter, +starts with a four, + +ends with an eight. + +That doesn't matter. + +Over here, let's say that +we look at the address + +that, let's say starts +in a four ends in a C. + +So we're saying, +we're hypothesizing, + +that maybe one of +these two addresses + +is going to be one of these +stack popping gadgets. + +And then let's say +that the trap up here, + +like I said this is just +going to be address zero, + +and then let's assume that we +found some preexisting stop + +gadget, some addresses start +the [INAUDIBLE] doesn't really + +matter. + +And remember this stop gadget, +like maybe this address, + +points to code that does +something like sleep 10, + +or something like that, right. + +So when I say that we're +going to test these sequences, + +this is the stuff that we're +going to push onto the stack, + +right. + +So similar to over there, when +we were pushing these gadgets + +onto the stack, +this is the stuff + +that we're going to +push onto the stack, + +and we're going to see +what happens, right. + +Now let's say that, +this code here, points + +to the following sequence. + +We're going to pop some +register, let's say racks, + +and then we're going to return. + +So what's going to happen here? + +Well so when the system +jumps this address, + +the stack pointer's +going to move here, OK. + +Now we're in the middle +of this gadget, right. + +What's the gadget going to do? + +It's going to pop racks, OK. + +Top of stack pointer's +now here, and it's + +going to return to whatever's +the top of the stack which + +is the stop gap, right. + +So in this case this +gadget gets us to here, + +and the attacker +can tell that this + +is-- this probe address belong +to one of these pop stacking + +things, right. + +Because the client +connection stays open. + +Now let's say that +this gadget here, + +pointed to something +like the following. + +Maybe it just does like +an xor, for example. + +So it's just going to xor +some registers and then it's + +going to ret. + +So what happens if we try +to jump to this gadget? + +Right, note that this does not +pop anything off the stack, OK. + +It just changes the +contents of registers. + +So what's going to happen? + +So we're going to +be here, we're going + +to jump to the address +of this gadget, + +stack pointer goes here, OK. + +We're going to xor +these two things, right. + +Stack pointer's not +going to change. + +Then we're going to return to +whatever the top of the stack + +is, which is 0, 0. + +This is going to crash. + +OK, the client connection to +the server is going to close, + +and as a result, the attacker +knows that this is not + +a stack popping gadget. + +So does that all make sense? + +And so you can also +imagine that you can-- + +by coming with more +baroque series of traps + +and stop gadgets +and stuff like that, + +you can find things that +for example, pop two things + +off the stack, right. + +You can just put another one +of these trap instructions + +there, right. + +And so then unless +the-- unless this gadget + +pops two things +off, you're going + +to end up in one of these +traps and your code execution + +is going to blow up, right. + +And so in the paper they discuss +like this thing called the BROP + +gadget, which is sort +of like hilariously + +complex if you're not used +to returning to programming. + +What I'll show you today +is you can actually + +just use these very +simple pop gadgets + +to launch the same attack. + +Then hopefully after +you understand this, + +the BROP gadget will +make more sense. + +But does everyone +understand how we can probe + +for these little gadgets here? + +OK. + +So, once you've got these +gadgets, what do you know? + +Well you found the location +of code snippets that + +allow you to pop stuff up, +one thing off the stack. + +Precisely one thing +off the stack, + +but you don't actually +know into what register + +they're popping it into. + +You just know that they're +getting popped off, right. + +And you actually +need to know what + +register these gadgets +are popping stuff + +into, because remember, +on a 64-bit architecture, + +the registers control where the +arguments are to this function + +that you want to invoke, right. + +So the ultimate goal +to keep in mind, + +is that we want to be able +to create some gadgets that + +allow us to pop values +that we put on the stack + +into certain registers, +and eventually we're + +going to call a system +call that's going to allow + +us to do something evil. + +OK, so the next thing +that we need to do + +is determine which +registers-- so determine which + +registers the pop gadgets use. + +So how are we going to do that? + +Well basically we can take +advantage of the pause system + +call. + +OK, so the pause system call, +it takes no arguments, right. + +And that means that it ignores +everything in the registers. + +OK. + +And essentially, to find +the pause instruction what + +we can do is, we can chain +all of these pop gadgets + +in such a way, that we put +all of them on the stack, + +in between each one of them +we put the syscall number + +for pause, and then we +see if we can actually + +get the program to hang. + +Let me give you a +concrete example of that. + +So we'll do something like this. + +So here for the return address, +we'll put the following. + +So let's say we have one +gadget that pops RDI register, + +then does a ret. + +And then up here we'll put +the syscall number for pause. + +And then let's say that we have +another gadget that we found, + +that does a pop into a different +register, let's say RSI. + +And then we'll put the +system call number for pause + +up here again. + +And we do this for all the +gadgets that we've found + +and then eventually we put +the guest address for pause, + +or sorry for syscall, excuse me. + +Once again, remember how you +invoke these system calls. + +So you basically have to put +the number of the system call + +into the RAX register, then +you invoke this libc function + +syscall which is then going to +execute the requested system + +call, OK. + +So what's going to happen +when we execute this code? + +Right, so we're +going to come here, + +we're going to jump to the +address of this gadget, + +and note that as an +attacker, all that we know + +is that this gadget here +pops something off the stack. + +We don't know what the +register is yet, right. + +Put it here just to +make the [INAUDIBLE], + +but the attacker +doesn't know yet, right. + +So if you jump-- or +sorry the-- we jump + +to the gadget, the +stack corners now here, + +what's it going to do? + +It's going to pop this +syscall number for pause, + +into some register the +attacker doesn't know, + +and then we're going to continue +to go up this chain and so + +on and so forth. + +And what you'll see is that +each one of these gadgets, one + +of them hopefully will +pop the system call + +number into the +appropriate RAX register. + +So that by the time +we get up to here, + +I mean we basically +polluted all the registers, + +with the system call number, +but hopefully just one of them + +has to be correct, right. + +Because if one of our gadgets +does this, then by the time + +we ret to here, +we'll get a pause. + +Once again, that pause acts as +a signal to the attacker, OK. + +Because if this guest +address was wrong, + +then probably the program's +going to crash, right. + +So what does this phase +of the attack let us do? + +Well we still don't +know which gadgets + +pop into which registers, +but we know that one of them + +is popped into RAX, which is +the one we want to control. + +And for sure we know the +address of syscall, right. + +Because we were able to +induce the pause, right. + +So once we've done that, right. + +Once we know for sure +where this thing is, + +the address for syscall, +then we can actually just + +try the gadgets +one by one, right. + +And see which one of +them is actually going + +to induce the pause, right. + +So in other words, cut all +the middleman here, let's + +have a stack it looks like this, +and then you just immediately + +jump to syscall. + +Did that cause the +pause or did it crash? + +If it crashed, OK +we know this gadget, + +it pops to RDI for example. + +OK, get rid of that one, right. + +Try the next gadget, right. + +Put the guest address-- put the, +well it's not guest anymore, + +put the real address +for syscall up here. + +Were we able to +pause the program? + +Yes? + +Aha, so we know that pop +gadget must pop into RAX. + +So does that make sense? + +AUDIENCE: So the way to guess +the address for system call + +is just blind transfer? + +PROFESSOR: Yeah, so +there-- so in the paper, + +they go into some +optimizations about how + +you can work in a PLT and +all that kind of stuff. + +Like I said, I think it's easier +to ignore that for a second, + +and just look toward +the simpler thing + +first, but yeah in a simple +attack that I'm describing, + +yeah you just put +some address up here + +and you just see if you pause. + +So does that all make sense? + +OK so at the end of +this we actually know + +the location of syscall. + +We know the location +of the instruction + +that does the pop into RAX. + +Now you can imagine that we +also need gadgets that pop + +into some other registers too. + +Suffice to say, you can +do similar tests, right. + +So instead of like pushing a +system call number for pause, + +push it for some +other command that + +now takes in all arguments in +RAX and RDI for example, right. + +Do the same type of test, right. + +So basically you can +leverage the fact + +that for any particular +set of registers + +that you want to +be able to control, + +there's some system +call that will give you + +a signal as an attacker, +that allow you to figure out + +whether you successfully +broke it or not. + +Right, so at the +end of this phase, + +you basically have +the address of syscall + +and the address of +a bunch of gadgets + +which allow you to pop +into arbitrary registers. + +OK and so now let's +see so, step 4 + +is going to be to invoke write. + +Step 4 is invoke the +write system call. + +So to invoke write, we need +to have the following gadgets. + +You need to be able to pop RDI. + +We need to be able to pop RSI. + +We need to be able to pop RDX, +pop racks, and then invoke + +syscall, right. + +So as it turns out, +what are these registers + +being used for by system call? + +So this is the socket, or more +generally, the file descriptor + +that you're going +to pass into write. + +This is the buffer. + +This is the length +of that buffer. + +This is the syscall number. + +And it is called syscall. + +Right, so if we found +all these gadgets, + +then we can actually +now control the values + +that are put into +those arguments, that + +put in those registers, +because we just pushed them + +on the stack, right. + +And so for example, what's +the socket going to be? + +For once you're going to have +to do a little guessing here, + +right. + +can take advantage of the +fact that Linux restricts + +the number of simultaneous +open file connections, + +for a file that's +going to be 2024. + +And also it's supposed to +be the lowest one available. + +So we do a little bit of +guessing here and figure out + +what that socket +is, put it in there. + +Now interestingly, +what are we going + +to pass into the buff pointer? + +Right, we're actually +going to use the text + +segment of the program. + +We're actually going to pass in +that the pointer to somewhere + +in the code of the program. + +So what's that going +to allow us to do? + +That's going to allows us to +read the binary, out of memory, + +using the right call +to the client socket. + +So that the attacker can +then take that binary, + +analyze it offline, right. + +Just use GDB, or +whatever, to figure out + +where everything is located. + +The attacker knows that now, +every time the server crashes, + +it's going to have the same +randomized set of things in it. + +So now, once the attacker can +find out addresses and offsets + +for stuff, now the +attacker can directly + +attack those gadgets, right. + +Directly attack other +vulnerabilities, + +figure out how to open up a +shell, so on and so forth. + +So in other words, +at the point you + +exfiltrated the binary to the +attacker, you basically lost. + +Right, so this is essentially +how the BROP attack works. + +Like I said, in +the paper, there's + +a bunch of optimization, +but really you + +need to understand this +stuff, the basic stuff, + +before that optimization +will start to make sense. + +And so we can talk about the +optimization with me offline + +if you want, or after class. + +But to suffice it +to say, this is + +the basics of how you +launch that BROP attack. + +You've got to find +the stop gadget, + +find those gadgets +that pop stack entries. + +Figure out which +of those registers + +those gadgets pop +into, and find out + +how to figure out where +syscall is, and then invoke + +write by accumulating +all that knowledge. + +So very quickly, how do +you defend against BROP? + +Well the most obvious +thing is you've + +got to rerandomize, right. + +So the fact that +crashed servers do not + +respawn, rerandomize +versions of themselves, + +that allows the crash to +act as a signal that let's + +the attacker test +various hypotheses + +about how the programs working. + +So one simple defense +is to make sure + +that you do exec when you spawn +your process, instead of fork, + +right. + +Because when you exec the +process, you create totally new + +randomized layout space, +at least on Linux, right. + +So on Linux, when you compile +with this PIE, the Position + +Independent Executable +flag, you only + +get that randomized +address space + +that's new if you use exec. + +So another event you can +use is just use Windows, + +because Windows +basically does not + +have a fork equivalent, right. + +So hooray for us. + +So that means that +on Windows, whenever + +you spawn that new +server, it's always + +going to have a new +randomized address space. + +I think someone over here +mentioned something like, + +what would happen +if for example, + +when the server crashed, +it didn't actually + +close the connection? + +Right, so you can +imagine one thing + +that when a crash takes place, +we somehow catch that fault + +and then we keep that connection +open for a little while + +to confuse the attacker +and remove that signal, + +that something's gone amiss. + +So that's something +you definitely do. + +What's hilarious about that +is, that now your BROP attack + +turns into a denial +of service attack. + +Because now you just got +all the potential zombie + +processes that are sitting +around, they segfaulted. + +They're useless in +society, but you + +can't let them go, because +otherwise you're going + +to delete this information. + +Another thing you +might think about to, + +is you could do bounds +checking, right. + +We just talked a bunch +about that, right. + +But in the paper, they +casually dismiss this + +as saying it has +up to 2x overhead, + +so nobody's going to do that, +but you could in fact do that. + +So that's basically +how BROP works. + +As for the homework +question, the homework + +questions a bit subtle, because +the homework question says, + +what if you use a hash of +the current time, right? + +Get time of day when you +restarted the program. + +Is that sufficient to +prevent this type of attack? + +Well note that, hashing +does not magically + +provide you bits of entropy +if the input to the hash + +is easily guessable, right. + +If I know that you're only +going to hash one or two things, + +it doesn't matter if I have +like some a jillion bit hash. + +Doesn't matter. + +So I can just guess one of those +two values and see what is. + +So the thing to note is +that get time of day, + +actually has much less +entropy than you might think. + +Particularly because the +attacker can actually + +check what time he or she is +launching the attack, right. + +So that's going to actually +remove a bunch of entropy + +from that calculation, right. + +So there's some +subtleties there. + +What's the server skew in +terms of clock or the client + +and so on and so forth. + +The long story short, using +a guessable base value, + +even with guessable +just inside of a range, + +is super useful for +the attacker, right. + +Particularly +because the attack-- + +we can start subverting a +bunch of servers in parallel + +and know that all +of them should have + +fairly similar values, right. + +This is a high order +of bits, right. + +So long story +short, the answer is + +that, it's literally better +than nothing to randomize, + +if you use get time of day, but +it doesn't actually provide you + +as much security as you think. + +And the other lesson too +is, that just because you + +hash something +right, that doesn't + +matter if you're not actually +using that hash in a smart way. + +You have a question? + +AUDIENCE: Oh, still when I +did the calculations that some + +[INAUDIBLE] it seems +like maybe to be + +able to get the offset +that the [INAUDIBLE] + +your [INAUDIBLE] +start the process + +to within like 48 milliseconds? + +PROFESSOR: Yes and +getting the timing right + +depends on a bunch of +different things, right. + +But you could take +advantage of the fact + +that the attacker can open +up a bunch of connections + +in parallel, and +leverage the fact + +that even if the initial +guess a little bit off, + +you can still launch +multiple guesses on what + +should be very +similar canary values, + +and do that attack in parallel. + +But you're right, there's +tricky time and issues. \ No newline at end of file diff --git a/x_DGTWH4tEA.txt b/x_DGTWH4tEA.txt new file mode 100644 index 0000000000000000000000000000000000000000..004c75373788f93d4bada7622c40f3c1102f6c55 --- /dev/null +++ b/x_DGTWH4tEA.txt @@ -0,0 +1,787 @@ +align:start position:0% + +so today was the + + align:start position:0% +so today was the + + + align:start position:0% +so today was the +lecture on scripting and hosting it's + + align:start position:0% +lecture on scripting and hosting it's + + + align:start position:0% +lecture on scripting and hosting it's +the end of day three + + align:start position:0% +the end of day three + + + align:start position:0% +the end of day three +this was probably the lecture that i was + + align:start position:0% +this was probably the lecture that i was + + + align:start position:0% +this was probably the lecture that i was +the most prepared for in terms of + + align:start position:0% +the most prepared for in terms of + + + align:start position:0% +the most prepared for in terms of +practice ahead of time ahead of this + + align:start position:0% +practice ahead of time ahead of this + + + align:start position:0% +practice ahead of time ahead of this +class + + align:start position:0% +class + + + align:start position:0% +class +because it's kind of like what george + + align:start position:0% +because it's kind of like what george + + + align:start position:0% +because it's kind of like what george +and i do + + align:start position:0% +and i do + + + align:start position:0% +and i do +for most of the production process that + + align:start position:0% +for most of the production process that + + + align:start position:0% +for most of the production process that +happens for science out loud so whenever + + align:start position:0% +happens for science out loud so whenever + + + align:start position:0% +happens for science out loud so whenever +we work with our students + + align:start position:0% +we work with our students + + + align:start position:0% +we work with our students +in the individual seasons + + align:start position:0% +in the individual seasons + + + align:start position:0% +in the individual seasons +this is basically what we do with them + + align:start position:0% +this is basically what we do with them + + + align:start position:0% +this is basically what we do with them +just a little bit more formalized and + + align:start position:0% +just a little bit more formalized and + + + align:start position:0% +just a little bit more formalized and +for a longer period of time it is + + align:start position:0% +for a longer period of time it is + + + align:start position:0% +for a longer period of time it is +so hard to teach + + align:start position:0% +so hard to teach + + + align:start position:0% +so hard to teach +good hosting because it's one of those + + align:start position:0% +good hosting because it's one of those + + + align:start position:0% +good hosting because it's one of those +things that you can sit and read about + + align:start position:0% +things that you can sit and read about + + + align:start position:0% +things that you can sit and read about +and you can watch + + align:start position:0% +and you can watch + + + align:start position:0% +and you can watch +a bunch of case studies and it just + + align:start position:0% +a bunch of case studies and it just + + + align:start position:0% +a bunch of case studies and it just +doesn't matter until you try to adopt it + + align:start position:0% +doesn't matter until you try to adopt it + + + align:start position:0% +doesn't matter until you try to adopt it +yourself i had planned + + align:start position:0% + + + + align:start position:0% + +all this material or it would be like + + align:start position:0% +all this material or it would be like + + + align:start position:0% +all this material or it would be like +there were all these videos of various + + align:start position:0% +there were all these videos of various + + + align:start position:0% +there were all these videos of various +hosts + + align:start position:0% +hosts + + + align:start position:0% +hosts +and it was going to be sort of a similar + + align:start position:0% +and it was going to be sort of a similar + + + align:start position:0% +and it was going to be sort of a similar +exercise to day one to all those youtube + + align:start position:0% +exercise to day one to all those youtube + + + align:start position:0% +exercise to day one to all those youtube +videos where they would go through and + + align:start position:0% +videos where they would go through and + + + align:start position:0% +videos where they would go through and +they would write you know some of the + + align:start position:0% +they would write you know some of the + + + align:start position:0% +they would write you know some of the +qualities that they liked and + + align:start position:0% +qualities that they liked and + + + align:start position:0% +qualities that they liked and +um try to see what they wanted to take + + align:start position:0% +um try to see what they wanted to take + + + align:start position:0% +um try to see what they wanted to take +on for themselves but we just + + align:start position:0% +on for themselves but we just + + + align:start position:0% +on for themselves but we just +totally scrapped it and i i think + + align:start position:0% +totally scrapped it and i i think + + + align:start position:0% +totally scrapped it and i i think +honestly it was much better that we did + + align:start position:0% +honestly it was much better that we did + + + align:start position:0% +honestly it was much better that we did +the hosting thing is hard and helping + + align:start position:0% +the hosting thing is hard and helping + + + align:start position:0% +the hosting thing is hard and helping +the students really be comfortable with + + align:start position:0% +the students really be comfortable with + + + align:start position:0% +the students really be comfortable with +their own voice and their own persona on + + align:start position:0% +their own voice and their own persona on + + + align:start position:0% +their own voice and their own persona on +screen + + align:start position:0% +screen + + + align:start position:0% +screen +it's really important so i don't want to + + align:start position:0% +it's really important so i don't want to + + + align:start position:0% +it's really important so i don't want to +distract from that at all one of the + + align:start position:0% +distract from that at all one of the + + + align:start position:0% +distract from that at all one of the +students wanted to minimize her presence + + align:start position:0% +students wanted to minimize her presence + + + align:start position:0% +students wanted to minimize her presence +on screen i don't want the students here + + align:start position:0% +on screen i don't want the students here + + + align:start position:0% +on screen i don't want the students here +to sell themselves short + + align:start position:0% +to sell themselves short + + + align:start position:0% +to sell themselves short +on on the power that they have as a + + align:start position:0% +on on the power that they have as a + + + align:start position:0% +on on the power that they have as a +practitioner of some of the science and + + align:start position:0% +practitioner of some of the science and + + + align:start position:0% +practitioner of some of the science and +the engineering + + align:start position:0% +the engineering + + + align:start position:0% +the engineering +to to default + + align:start position:0% +to to default + + + align:start position:0% +to to default +to a type of video that + + align:start position:0% +to a type of video that + + + align:start position:0% +to a type of video that +a lot of other people can make these + + align:start position:0% +a lot of other people can make these + + + align:start position:0% +a lot of other people can make these +students are not the best hosts finding + + align:start position:0% +students are not the best hosts finding + + + align:start position:0% +students are not the best hosts finding +like a neil degrasse tyson at mit + + align:start position:0% +like a neil degrasse tyson at mit + + + align:start position:0% +like a neil degrasse tyson at mit +you can't bank on that and i don't mean + + align:start position:0% +you can't bank on that and i don't mean + + + align:start position:0% +you can't bank on that and i don't mean +that in a mean way perhaps i should + + align:start position:0% +that in a mean way perhaps i should + + + align:start position:0% +that in a mean way perhaps i should +rephrase this maybe they can cut this + + align:start position:0% +rephrase this maybe they can cut this + + + align:start position:0% +rephrase this maybe they can cut this +out + + align:start position:0% +out + + + align:start position:0% +out +it is an imprudent thing to assume that + + align:start position:0% +it is an imprudent thing to assume that + + + align:start position:0% +it is an imprudent thing to assume that +we're going to find the next bill night + + align:start position:0% +we're going to find the next bill night + + + align:start position:0% +we're going to find the next bill night +at mit we can expect the students to + + align:start position:0% +at mit we can expect the students to + + + align:start position:0% +at mit we can expect the students to +become like hank green and to make the + + align:start position:0% +become like hank green and to make the + + + align:start position:0% +become like hank green and to make the +next sci show like that's an unfair + + align:start position:0% +next sci show like that's an unfair + + + align:start position:0% +next sci show like that's an unfair +expectation to have but the value + + align:start position:0% +expectation to have but the value + + + align:start position:0% +expectation to have but the value +proposition + + align:start position:0% +proposition + + + align:start position:0% +proposition +that they offer here which i think is so + + align:start position:0% +that they offer here which i think is so + + + align:start position:0% +that they offer here which i think is so +powerful which i think is the most + + align:start position:0% +powerful which i think is the most + + + align:start position:0% +powerful which i think is the most +important thing + + align:start position:0% +important thing + + + align:start position:0% +important thing +that someone like michael stevens on + + align:start position:0% +that someone like michael stevens on + + + align:start position:0% +that someone like michael stevens on +vsauce can't do and scishow can't do is + + align:start position:0% +vsauce can't do and scishow can't do is + + + align:start position:0% +vsauce can't do and scishow can't do is +that they are the scientists they are + + align:start position:0% +that they are the scientists they are + + + align:start position:0% +that they are the scientists they are +the people who worked in the industry + + align:start position:0% +the people who worked in the industry + + + align:start position:0% +the people who worked in the industry +they are the + + align:start position:0% +they are the + + + align:start position:0% +they are the +they are the actual naval engineers that + + align:start position:0% +they are the actual naval engineers that + + + align:start position:0% +they are the actual naval engineers that +is something + + align:start position:0% +is something + + + align:start position:0% +is something +for me personally is so important to + + align:start position:0% +for me personally is so important to + + + align:start position:0% +for me personally is so important to +highlight so to make themselves evident + + align:start position:0% +highlight so to make themselves evident + + + align:start position:0% +highlight so to make themselves evident +i think is really important to make + + align:start position:0% +i think is really important to make + + + align:start position:0% +i think is really important to make +themselves the host to make themselves + + align:start position:0% +themselves the host to make themselves + + + align:start position:0% +themselves the host to make themselves +visible to + + align:start position:0% +visible to + + + align:start position:0% +visible to +to make their persona and their actual + + align:start position:0% +to make their persona and their actual + + + align:start position:0% +to make their persona and their actual +personal stories + + align:start position:0% +personal stories + + + align:start position:0% +personal stories +part of the video i think is important + + align:start position:0% +part of the video i think is important + + + align:start position:0% +part of the video i think is important +whether + + align:start position:0% +whether + + + align:start position:0% +whether +you're in front of a camera or you're on + + align:start position:0% +you're in front of a camera or you're on + + + align:start position:0% +you're in front of a camera or you're on +a stage or you're on a podium giving a + + align:start position:0% +a stage or you're on a podium giving a + + + align:start position:0% +a stage or you're on a podium giving a +talk + + align:start position:0% +talk + + + align:start position:0% +talk +the habit of falling back into this + + align:start position:0% +the habit of falling back into this + + + align:start position:0% +the habit of falling back into this +monotonous robotic + + align:start position:0% +monotonous robotic + + + align:start position:0% +monotonous robotic +or perceived persona that you think you + + align:start position:0% +or perceived persona that you think you + + + align:start position:0% +or perceived persona that you think you +have to take on + + align:start position:0% +have to take on + + + align:start position:0% +have to take on +totally happens all the time + + align:start position:0% +totally happens all the time + + + align:start position:0% +totally happens all the time +so i think it's a relevant lesson that + + align:start position:0% +so i think it's a relevant lesson that + + + align:start position:0% +so i think it's a relevant lesson that +people can take with them after this + + align:start position:0% +people can take with them after this + + + align:start position:0% +people can take with them after this +class is over + + align:start position:0% +class is over + + + align:start position:0% +class is over +i'm definitely rambling at this point + + align:start position:0% +i'm definitely rambling at this point + + + align:start position:0% +i'm definitely rambling at this point +maybe it's because george said most of + + align:start position:0% +maybe it's because george said most of + + + align:start position:0% +maybe it's because george said most of +the talking today + + align:start position:0% +the talking today + + + align:start position:0% +the talking today +um + + align:start position:0% +um + + + align:start position:0% +um +but i think it went + + align:start position:0% +but i think it went + + + align:start position:0% +but i think it went +i think it went okay \ No newline at end of file diff --git a/xuAD_a1OuNo.txt b/xuAD_a1OuNo.txt new file mode 100644 index 0000000000000000000000000000000000000000..26751b2243b0e9672d274d63698a6d9307421cff --- /dev/null +++ b/xuAD_a1OuNo.txt @@ -0,0 +1,3672 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality, educational + +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: We're going to talk +about something we've sort of + +touched on, in many different +contexts, but more head on + +this time, and that's +entrepreneurship. + +And sort of the starting point +of that, I think, there's a + +story that somebody once told +me, which, I thought, kind of + +frames one side of the +debate very well. + +I was on the plane with a man, +who was clearly sort of a + +rich, Indian businessman. + +And he was quizzing me +about what I did. + +And I said, I study economics +and poor people. + +And he was very much +of the view. + +He said, look, you know, there's +all this stuff about + +poor people. + +You guys don't understand +poor people. + +They have an entrepreneurial +genius in them. + +You think I'm a successful +entrepreneur. + +The way I learned +entrepreneurship + +was from the poor. + +So I was kind of saying, yeah, +yeah, yeah, right. + +Well then he told me a story +that was actually quite + +compelling. + +And mostly people-- + +whatever this means, it's +never clear to me. + +So I was being slightly +skeptical. + +But then he told me a story +that was very compelling. + +So he said that he had +an MBA from the US. + +I think from Kellogg. + +And he went back to India +after doing his MBA. + +And when he arrived in India, +his uncle, who was a + +businessman in Bombay, said +look, you want to be an + +entrepreneur. + +Let me show you what +entrepreneurship is. + +So basically, they got +in his uncle's car. + +The uncle drove him +all the way to the + +Bombay stock exchange. + +The Bombay stock exchange, well, +he thought that they + +would just go inside +the stock exchange. + +But in fact, he parked his car +in front of the exchange and + +pointed to four women who were +sitting on the side of the + +street that goes in front +of the exchange. + +And he said, you know, can you +figure out what those women's + +business model is? + +So he says, well, I +looked and looked. + +And they would just get +up, from time to time. + +They'll scrape something off the +street, then they'll come + +and sit down. + +And then they'll be sitting +and talking to each other. + +It's early in the morning, like +8:30 in the morning or + +9:00 in the morning. + +Cars were driving by. + +People were showing up to work +at the stock exchange. + +But what does it have anything +to do with entrepreneurship? + +So he kind of tried to come up +with some answer, completely + +didn't manage, and finally +told his uncle, + +look, I have no idea. + +Why don't you tell me? + +His uncle said, these women get +up at 5:30 in the morning. + +They go to the beach. + +In the morning, the tide has +receded, so there's wet sand + +on the beach. + +They collect the wet sand and +then they put it in a bag. + +They come to the +stock exchange. + +This is one place where +lots of cars go by. + +And there's a nice +sidewalk to sit. + +Before the traffic starts, +they lay the + +sand out on the street. + +And then they sit there. + +And as people drive on the +stand, the heat from the tires + +dries the sand. + +So the sand gets heated and +eventually dried by the tires. + +Once the sand is fully dry, they +scrape off the sand and + +put it in a bag and take +it back to the + +slums where they live. + +Women use this dry sand +as like a scrubber. + +To clean dishes, you use +this dry sand as a + +scrubber for that. + +And so they use this +dry sand to scrub + +off their dirty dishes. + +And that's all dirty-- + +I don't know, whatever-- + +cook pot and pans. + +And that's how these people +make a living. + +They dry the sand, +and they sell it. + +So this was his example of how +infinitely creative poor + +people are. + +And my reaction to that was, +you know, isn't that saying + +much more about how creative +you have to be to make a + +living if you are poor then +how creative the poor are? + +So it's the same proposition, +in a sense. + +You could say that this +shows that the + +poor are very creative. + +Or you could show that the +poor have no business + +opportunities so they have to +do this completely bizarre + +thing to make a living. + +And those are just two sides +of the same coin. + +And I don't know. + +So what I want to talk about +today is a bit on this + +implicit and often +explicit debate-- + +So before we get there-- + +on whether the poor are +entrepreneurial in some + +meaningful sense of +the word or not. + +So let's start at +the beginning. + +Who's an entrepreneur? + +How do you define +an entrepreneur? + +AUDIENCE: I guess I would define +an entrepreneur as + +someone who goes about creating +a new venture that + +often involves a greater than +average amount of risk. + +PROFESSOR: So if I am someone +who works for Toyota and + +designs a slightly different +car, am I an entrepreneur? + +AUDIENCE: I would say not. + +PROFESSOR: Why not? + +It's risk. + +I could fail. + +I would look really, really +stupid to my bosses. + +AUDIENCE: But it creates +a new venture. + +I mean, right there, you're +developing a product inside. + +PROFESSOR: New venture? + +So it has to be a new, +separate company. + +Is that the definition? + +AUDIENCE: No, but I'd say a +venture not a design, right? + +PROFESSOR: But I haven't +got what that means. + +AUDIENCE: Like a venture in +the sense that it doesn't + +necessarily have to be entirely +its own company, but + +it's more than just a design. + +In the sense of a design, but +then you're not taking into + +account the other things that +would actually go into making + +it a car and then +selling that. + +Like let's say Toyota decides +to launch a new line, where + +they're going to do a new +dealership agreement, new + +factory, all that, then that +would be a new venture. + +If I was running that, then I +could be classified, under my + +definition, as an +entrepreneur. + +PROFESSOR: OK. + +So you would-- + +OK, go ahead. + +No, you should go ahead. + +AUDIENCE: I think the term, that +we'd have to go into the + +definition. + +Besides just creating a new +venture, it would be create a + +new venture that is, somehow, +innovative and + +unique in it's own. + +So I think, whether not, +necessarily, the business idea + +or the business strategy of the +product, but maybe even in + +how the person operates the +company, they can be + +entrepreneurs in that way. + +PROFESSOR: So you don't think +that if I have a set of taxis + +I'm an entrepreneur? + +I just bought a set of taxis. + +I rent them out. + +AUDIENCE: I would imagine if you +were the person who took + +the initiative to-- + +PROFESSOR: But this was after +there had been 500,000 taxi + +companies in the world. + +If I go tomorrow, quit my job, +and I start a taxi company, I + +would not be an entrepreneur? + +AUDIENCE: Well, to some +degree, you could + +that's still unique. + +You're starting a taxi company, +in a particular city, + +with a particular +set of drivers. + +PROFESSOR: But then everything's +unique. + +Once I go down that road, I +don's see how anything. + +I can't have a taxi company +which has the same set of + +drivers as theirs, +everybody else. + +So this is unique +by definition. + +Somebody else from +that side, yeah? + +AUDIENCE: I think someone was +actually saying before that + +created a normal +amount of risk. + +But it's like the financial +risk, as well, absorbing that + +yourself, as opposed to being +responsible for it underneath + +an organization. + +PROFESSOR: Right. + +I think that's actually one +key piece of what I would + +consider the definition. + +The fact that you a lot +of the risk comes + +from raising capital. + +The risk is a significant +part of the reason why. + +If I work for Toyota +there would not be. + +It could be career +risk for me. + +But it would not be risk that +is driven by my having to + +raise capital. + +So I think you're making one of +the key points, which is, I + +think, exactly as you said. + +Risk is a big piece of it. + +The next piece of it +is the risk comes + +from raising capital. + +I would not say that it has to +be a new product, because I + +think that's too narrow +a definition. + +I mean you could define it. + +But I think that would mean no +poor people are, essentially, + +entrepreneurs. + +But I think raising capital, +the financing side of it. + +So do you take the risk? + +And a lot of the risk comes from +owning the asset that's + +generating the output. + +That, I think, is a key part +of being an entrepreneur. + +The risk comes from putting +money or your own + +assets on the line. + +It's not just that you're +putting your career or your + +name on the line. + +When I write a book, I also +take a risk in that sense. + +People could say, my god, +what a stupid book. + +That's a risk, but I wouldn't +call myself an entrepreneur. + +So I think that I want to +emphasize that I think the + +poor are entrepreneurial. + +When we talk about somebody who +is an entrepreneur, I'm + +going to emphasize the fact that +they bear a lot of the + +risk, from production, and that +risk is closely tied to + +the ownership of the asset. + +So it is that they have to +finance the asset and hold on + +to the risk generated +by that asset. + +So they could be a farmer. + +They must have to own +the land and then + +take the farming risk. + +Yeah? + +AUDIENCE: But in the US, don't +a lot of the people, who we + +think of as entrepreneurs, they +get venture capital or + +somebody else to take on +the financial risk. + +AUDIENCE: But it kind of defers +the financial risk. + +They're still taking on +financial risk of their own. + +PROFESSOR: But first, I think, +nobody gets 100% venture + +capital funding. + +Even to get to the venture +capital stage, you typically + +spend a fair amount of money. + +And nobody gets 100% +funding even then. + +And second, in some ways, you +still take financial risk, in + +the sense that the upside on +the venture capital is + +precisely your earnings +in the future. + +So you, basically, dock +your earnings. + +You are an owner. + +You have arranged a particular +form of financing, which says + +that I don't make any payments +for the time + +being, on this financing. + +But it's exactly like any +other form of financing. + +I have an obligation +to pay you. + +That obligation, in venture +capital, is + +maybe in five years. + +If the company goes public, +then I will + +pay you $100 million. + +That's a venture capital +contract. + +It's still, basically, +a sharing of risk. + +And I'm taking ownership +of the asset. + +It's just a different +contract. + +Yeah. + +AUDIENCE: It's also the +opportunity cost of actually + +putting all of your energy into +this venture to see it + +come to fruition, like all the +earnings that you could have + +earned in that time working +[INAUDIBLE]. + +PROFESSOR: But that's a bit +like I could have spent my + +time consulting or I +could write a book. + +I mean that's not +that different. + +I think the key is that my +earnings are significantly + +connected to the outcome +of the project. + +I was just adding to the cost of +what of entrepreneur takes + +on [INAUDIBLE]. + +AUDIENCE: I mean, if you wrote +a book that sold 10 million + +copies or something, then your +future earnings would be + +significantly. + +PROFESSOR: Yeah, but mostly, I +think the first order risk, + +sadly, for me is that people +will just think I'm stupid. + +I think the risk, in my case. + +You could imagine everybody has +a small chance of being an + +entrepreneur, but I think that +mostly, most of my risk has + +something to do with my ability +to convince other + +people that I have not lost my +marbles and very little of my + +risk comes from money. + +AUDIENCE: Yeah, but at the same +time, there's some people + +who are like full-time +authors. + +And they take out loans. + +And they write this book. + +PROFESSOR: Oh, they are +entrepreneurial. + +I'm not saying they are +not entrepreneurs. + +I think I am not an +entrepreneur, to first + +approximation, because my risk +is mostly reputational risk, + +very little of it is +financial risk. + +AUDIENCE: Even though you're +sort of doing a similar thing? + +PROFESSOR: Yes. + +My lifetime earnings are, +essentially, with a 99% + +probability, are unaffected by +this decision, or almost + +unaffected. + +So who is and isn't +an entrepreneur? + +So we've sort of been +talking about that. + +I'm not, but who is? + +So clearly, Larry Page and +Sergey Brin are entrepreneurs. + +Now let's take something +less obvious. + +What are other forms of +entrepreneurship, like in the + +US, less obvious ones then +starting a software company? + +AUDIENCE: I mean someone who +owns and rents a foodtruck. + +So + +PROFESSOR: That's an +entrepreneur, sure. + +AUDIENCE: Someone who +starts a laundromat. + +PROFESSOR: That's +an entrepreneur. + +AUDIENCE: So I kind of disagree +with the fact that + +you've got to have some +sort of earnings + +attached to your venture. + +I think if somebody starts a +business that focused on + +community service but is very +unique, entrepreneurial, I + +think that is still. + +If it is innovative in some way, +I still think it should + +be considered as +entrepreneurship. + +PROFESSOR: I think they say, +sometimes, somebody is a + +political entrepreneur. + +But I think that gets the term +to be a little bit too hard to + +understand. + +I mean, I think you could make +the case that you're making. + +I'm going to sort of resist +that a little bit. + +Because I think, then, +I don't know what + +the limits are anymore. + +Who's not a political +entrepreneur? + +If I go and claim that President +Obama was born in + +Kenya, am I a political +entrepreneur or not? + +Is that entrepreneurial? + +Yes, it's entrepreneurial. + +It's innovative. + +I feel like that's making +it too easy. + +AUDIENCE: So were the people +collecting sand entrepreneurs? + +PROFESSOR: Sure. + +They owned this enterprise. + +Their entire earnings +was subject to that. + +They had financed whatever +needed to be financed. + +They had paid for the +plastic bucket. + +They collected the +sand, the spade. + +They had paid the bus fare to +get from the beach to the + +Bombay stock exchange. + +They had done all +of the financial + +investment that was involved. + +It just happens to a small +amount of money. + +But that doesn't mean that +they hadn't done-- + +they had put in 100% of +the capital in there. + +But another example, just to +not get too stuck on it. + +Lawyers, for example, most +lawyers are, effectively, + +entrepreneurs. + +Because most lawyers actually +have a two-person, + +three-person partnership. + +They're bearing a lot of risk. + +They pay for the staff. + +They pay for the office. + +They pay for the whatever, +the furniture. + +And so, in that sense, they +would, under this definition, + +also count. + +AUDIENCE: I was going to say +you could also say that for + +doctors as well. + +PROFESSOR: Doctors the same, +a lot of doctors. + +I think that's relevant, because +the typical way-- + +there's no measurement of +entrepreneurship in the data. + +Because nobody knows who's an +entrepreneur, for the same + +reason as we were having +trouble with it. + +What is measured in the data +is whether you describe + +yourself as self-employed. + +That's described in the data. + +So if you look at most +countries, one of the + +employment categories +is self-employed. + +And that number, which includes +lawyers, doctors, + +consultants, many other such +people, and not just + +laundromat owners and Google +owners, but lots of other + +people, that category turns +out to be about 12% of the + +population. + +So 12% of the population, +under a very generous + +definition of entrepreneur, +which is self-employed, are + +entrepreneurs. + +That's for the OECD. + +The OECD is like all the rich +countries in the world. + +In the rich countries, roughly +12% of the population would + +call themselves self-employed. + +That number is much +higher among the + +poor in poor countries. + +And I'm going to show +you some numbers. + +So here's some numbers. + +So self-employed in agriculture, +rural population, + +you can see that, in many +countries, over 75 to even + +100%, nearly, are self-employed +in agriculture. + +Take Panama or Pakistan, like +70% of these people are + +self-employed in agriculture. + +Meaning that they, basically, +exactly using the equivalent + +definition to the one that's +used in the OECD, which is + +that they describe themselves +as self-employed. + +Meaning that, typically, they +are putting up the capital, + +usually the land and the inputs, +and they're getting + +the returns. + +So they are risk taking. + +And they're betting a lot of +risk, and they own the assets + +that are generating that risk. + +So that's a number +that's high. + +As you will see, that number +is, in a sense, an + +underestimate of how +many people are + +self-employed overall. + +So this is just in +agriculture. + +This is how many people who +have somebody who's + +self-employed in +non-agricultural work. + +In Brazil, rural Brazil, +60-something-percent are + +self-employed in +non-agricultural work. + +So who are these people? + +They're like somebody who +provides any services, a + +barber, carpenters, somebody +who builds, a bricklayer. + +Instead of a working as a part +of a company, most of these + +people just work as +single-person enterprises. + +So bricklayers are +bricklayers. + +They have a brick laying +company, which is themselves. + +And they, typically, will do the +brick laying for somebody. + +In many ways, this is another. + +So if you have to take the +fraction of people who are + +self-employed, either in +agricultural or not, or + +somebody in their family is +self-employed in either + +agriculture or outside +agriculture, that's and even + +higher fraction. + +That's like 70% of most poor +people have somebody in the + +family who is self-employed. + +So this is a combination of +these two sets of numbers. + +And some of them are both. + +Some of them have one family +member who is self-employed in + +agriculture, one family member +who is self-employed outside + +agriculture. + +But even if you take +the average, it's + +quite a high number. + +So most poor people, in our +definition, are at least + +self-employed. + +Well, why is this? + +Yeah? + +AUDIENCE: What would we consider +sharecroppers, who + +have to bear a lot +of the risk? + +PROFESSOR: I think, here, they +are considered self-employed. + +But that's a good question. + +I don't know the answer to +whether they should be or not. + +So why should we think +there is anything + +interesting about this? + +Why would it be at all +surprising if a lot of poor + +people were entrepreneurs? + +Why would it be even worth +commenting on? + +AUDIENCE: I don't understand +the question? + +PROFESSOR: I said that 12% of +the people in rich countries + +are entrepreneurs. + +Maybe 70% of the poor, in poor +countries, are entrepreneurs. + +Is that something that +has anything + +interesting about that fact? + +And there I want to get you +to these two questions. + +Is it the case that the poor +have specific advantages being + +an entrepreneur? + +Do they have specific +disadvantages in being + +entrepreneurs? + +So let's start with +the disadvantages. + +Is that clear? + +AUDIENCE: The risk is higher, +because the overall capital + +they have is less. + +PROFESSOR: So risk is at least +relatively higher, because + +they have-- + +I don't know where this came +from, but I kind of know where + +it should go. + +So one thing that's +clear is that + +entrepreneurship is risky. + +If you're at the margin of not +having enough money for + +something really essential, +then the same + +risk hurts you more. + +Because you're really +in danger of + +something awful happening. + +Like you couldn't pay for your +mother's hospital stay if your + +business collapses. + +So the risk is much +more important. + +We talked about this +some few weeks ago. + +Other reasons, other +disadvantages? + +AUDIENCE: It's harder +to raise capital. + +PROFESSOR: Sure. + +It's harder to raise capital. + +If you don't have a bank +account, if you don't have + +assets that you can pledge, if +you don't have contact among + +financials, it's harder to +raise capital, surely. + +Yeah? + +AUDIENCE: You have to rely on +your business more, because + +it's harder for you to get a +steady paying job at some + +other company. + +PROFESSOR: Is that a +disadvantage or an advantage? + +AUDIENCE: I think it's a +disadvantage, because then you + +bear a lot of the risk +of the business. + +PROFESSOR: I see. + +So you may not have skills +that you would get you an + +alternative job, so if your +business fails, then it + +really hurts you. + +I see. + +Yeah. + +AUDIENCE: Particularly, if +you're really poor, in a rural + +area or a slum, it's really +hard to get the resources. + +I mean, I feel like in America +today, we have a whole lot of + +resources to encourage +entrepreneurship and help + +entrepreneurs. + +I would imagine, based on what +I've read, that that really + +doesn't exist. + +PROFESSOR: So you may not have +the know-how to be an + +entrepreneur. + +You may not know what market +opportunities are available, + +because you're not that well +connected to the media. + +You may not know, even, what the +best prices are for what + +you will buy and the best prices +are for what you will + +sell, where to sell, all the +information that you need. + +Presumably, that's correlated +with being educated. + +And so if you are poor in a +poor country, you are less + +likely to have all +that information. + +AUDIENCE: This is something +that applies to all + +entreprenuers. + +But I think it would affect the +poor more, specifically. + +I was thinking about the +benefits you get from working + +for a corporation. + +Sometimes you get health +care, things like that. + +And so being an entrepreneur +is like taking a risk with + +respect to that. + +And then for the poor, depending +on where they live, + +or what atmosphere is around, +it might disproportionately + +affect them. + +PROFESSOR: Yeah, that's also +possible that there's some + +additional benefits to +having a steady job. + +That's particularly important +if you have no + +other source of support. + +Yeah? + +AUDIENCE: On the advantages +side, couldn't you say-- + +PROFESSOR: Let's do +the disadvantages. + +Hold that. + +AUDIENCE: Wouldn't your +income not be regular. + +It would be really uncertain. + +PROFESSOR: Yeah. + +So that's related to, I think, +the first point that was made. + +AUDIENCE: Chances are, +you're not going to + +have an original idea. + +You're going to be copying what +other people are doing. + +PROFESSOR: Yeah. + +But why would it be less true +of the poor than the rich. + +AUDIENCE: The rich might have +access to educational + +resources that will allow them +to come up with better ideas. + +AUDIENCE: You could also make +the converse argument that + +since the rich have access to +more stuff, they're more + +likely to copy other ideas. + +PROFESSOR: Good. + +AUDIENCE: But that would also +mean they might not be as + +likely to make a lot of money. + +So those would be the bad, +rich entrepreneurs. + +AUDIENCE: Not necessarily. + +Microsoft copied Apple's +architecture [INAUDIBLE]. + +AUDIENCE: Well, that's +a different story. + +AUDIENCE: I mean this was +already said before. + +But just thinking about like, +if you're poor, you're going + +to have to use-- + +an entrepreneur, let's say you +had some savings or you had + +family that was helping +support you. + +You have support system that has +some sort of capital, even + +if it's not that much. + +But when you're poor, you have +to use everything that you + +have to put into +that business. + +And that takes away from just +living, even things like that. + +PROFESSOR: So the risk is +higher, and your ability to + +self-finance is lower. + +Anything else? + +Yeah? + +AUDIENCE: You could say, if +other people copied your idea, + +it would hurt you more, because +then they'd just + +increase the supply and decrease +your overall-- + +PROFESSOR: But why would +it be any different + +from anybody else? + +If I'm rich and you copy my +idea, that still hurts me. + +It is not clear, especially in +the sense if the poor use + +ideas that are particularly-- + +they've already copied +from somebody. + +They're less hurt by copying. + +Yeah? + +AUDIENCE: Perhaps, if you +think about the social + +infrastructure, people are +more able to copy ideas, + +because of the lack of legal +support or an ability to check + +or to enforce that people are +not copying your ideas. + +PROFESSOR: Right, so you might +thing that they have less + +access to lawyers +and things like. + +They may not understand +the law well. + +So they may not be able to use +the legal system to protect + +themselves as effectively. + +What's another thing that helps +an entrepreneurs other + +than money and ideas? + +What's the third thing that? + +AUDIENCE: Sort of broadly +speaking, a social safety net. + +In the sense that, let's say, +in American, you're + +entrepreneur and you absolutely +fail, there's still + +a social safety net that you +could at least rely upon. + +And that doesn't +exist in poor-- + +PROFESSOR: Right. + +That's true of poor countries, +but not necessarily more of + +poor people. + +That's a point about +poor countries, + +less about poor people. + +One other thing that I think +matters a lot is contacts. + +I think that, if you know +somebody, if your uncle is the + +CEO of a company, they +may be more willing + +to give you a try. + +If you're starting up, you're +making widgets, somebody has + +to buy them. + +It's much easier if you know +somebody than if you don't. + +I mean, why would anybody +trust you? + +So you often get your first +breaks by having some + +connection to somebody else, +who will do the buying. + +And I think that's a very big +piece of what makes it very + +difficult for the poor to be +effective entrepreneurs is + +that they actually don't +know anybody. + +And so it's much harder +for them to + +break in with a products. + +So I think contacts are a +very big piece of it. + +The other part of it is that it +might be that, in order to + +be in business, for example-- + +take the venture capital +example. + +Typically, the way a lot of +start-ups work is that you + +know that you're going to +lose money for a while. + +Because you have to build +a reputation. + +And the way you build a +reputation is by going to + +someone and saying, look, you're +buying from him for $5. + +I'll sell it to you for $3. + +And you know you lose money at +$3, but you're willing to lose + +money for a while, because that +way he'll see that you're + +really good at doing it. + +And then, maybe, you could +charge $4 and get the market. + +So a lot of way new businesses +start is by actually + +undercutting other businesses +and losing money. + +So if you can't lose money, +effectively-- + +so if you're poor and you can't +afford to lose money, + +it's often very difficult +to enter a new product. + +Because part of the way you +enter the new product is by + +actually selling +it very cheap. + +And it's very difficult to +sell it very cheap if you + +can't afford to lose money. + +So those are all the +disadvantages. + +Are there advantages? + +So I don't know how many of you +know, but there's a very + +famous book called The Fortune +at the Bottom of the Pyramid. + +If you've read that book, it +makes the case that there's + +actually lots of entrepreneurial +opportunities + +for the poor. + +And that, in some sense, they +might have an advantage. + +What are potential advantages? + +Yeah? + +AUDIENCE: Because you have +access to a unique market that + +the rich don't even know +about, like the + +women who sell sand. + +PROFESSOR: So they might know +about things which are + +underserved. + +So maybe the way capitalism has +developed, it's better at + +serving the demands of +the middle classes. + +The poor might demand certain +products which are not + +supplied by the market. + +So at this point, it might be +easier to find a new product + +to supply if you know +what the poor want . + +That's one of the cases +that's being made. + +We'll see to what extent +that's true. + +Any others? + +You were going to mention +something? + +AUDIENCE: Maybe it's easier to +make use of some resources + +than it would be if you were a +richer person trying to start + +a [INAUDIBLE]. + +Like, for example, the women +with the sand, they can go to + +the beach and dig up some +sand and carry it away. + +No one's going to say +anything to them. + +But if someone was trying to do +this on larger scale, then + +there would be issues. + +PROFESSOR: That's +exactly right. + +So it may well be that, if I'm +the person who comes and-- + +imagine that I'm rich. + +Let's say, I can either take +a job or I can be an + +entrepreneur. + +To compensate me for my job, I +would need to be able to do + +the business at a particular +scale. + +Imagine I'm in the business of +sorting through garbage and + +finding things which +are sellable. + +Just doing that, physically, if +I started to use that much + +garbage, I'll need +a lot of space. + +Whereas a poor person may be +able to cover her daily wage, + +which is very low, by just +sorting through the garbage + +she finds in the neighborhood +or something. + +Another advantage of being poor +might be that you may be + +less considered or less easily +monitored, so you may be able + +to bend the rules more +effectively. + +So you might be able to make +products, which somebody else + +would not want to do, because +it would too easy to + +scrutinize. + +So you may be involved in-- + +I'm not saying illegal products, +but you might use + +techniques which are possibly +less hygienic or something. + +So if I setup a big factory +dyeing garments, that pollutes + +the water supply. + +And the city will +shut me down. + +If I have a very small operation +inside my house, + +dyeing garments, nobody +will notice. + +And I could use the city's water +supply and pollute it. + +This doesn't mean that I'm +doing a good thing. + +But it means that it might +be easier for me to be an + +entrepreneur, the producing +and dyeing garments than + +somebody who's richer than me. + +So there's some potential +advantages. + +Still, I think my sense is that +everybody would think + +that, basically, it's easier +for the rich to be + +entrepreneurs than the poor. + +So that's on balance. + +And we'll look at this +a little bit, in + +the data, in a bit. + +So then why are the poor +entrepreneurs? + +That's the question +that comes back. + +If we say it's easier for the +rich to be entrepreneurs, but + +the rich are less likely to be +entrepreneurs than the poor, + +then we have a kind +of a puzzle. + +Why are the poor +entrepreneurs? + +What is it that? + +So one view of this is sort +of Muhammad Yunus's view. + +Muhammad Yunus is the guy who +started Grameen Bank. + +And he's on record saying that +the poor are natural born + +entrepreneurs. + +So there's one view, which is +to say that something about + +the poor, which, by being +poor, they learn to be + +entrepreneurial. + +They can't really survive on +anything else, so they become + +like these women we were talking +about. they become + +very clever at finding +opportunities. + +They are natural +entrepreneurs. + +That's one way to think about it +is that, when you are poor, + +you're just better at thinking +about opportunities. + +Now, one way we can kind of +address this is by looking at + +the businesses of the poor. + +What do you know about +these businesses? + +So these are people who +are under $1 a day. + +And if you take the business of +people, who live under $1 a + +day, I think the striking fact +is that, in most countries for + +which we have data, let's say, +10%, so the average number of + +employees in a business +is 0.15. + +It's one in seven businesses +have an + +employee, a paid employee. + +They took two countries where +it's different, but even in + +those countries, they don't +have one employee. + +They have 0.6 employees. + +So these are very small +businesses. + +The first thing to note is that +the businesses of the + +poor are kind of very, very +small businesses. + +This includes your unpaid +employees, which is like your + +son or your wife or +you, yourself. + +And that number is +just over one. + +So the average number of +employees is just over one, + +meaning that it's you plus +somebody who works, maybe, + +part of the time. + +Or alternatively, it's you and +no one or you plus one person, + +but not much more than that, +so very few employees. + +Second, what fraction of the +businesses own a vehicle? + +Just to measure some other +measure of the size of the + +business, it's only a vehicle. + +And Pakistan is the +one country where + +many people own cycles. + +They might be delivering stuff, +but then, all the other + +countries, it's really, +really small, like 5%. + +If you look at an even more +obvious question, what + +fraction own machines, +any machine? + +The answer is not +100% even there. + +60% in the Ivory Coast +own any machine. + +What's the average machine +that they own? + +They own a weighing scale or +sort of a piece of metal for + +digging something, but +no more than that. + +So it's really like these +businesses have no assets + +whatsoever. + +So the first point about the +businesses of the poor, they + +are very small, by all +of these measures. + +They have no employees, no +machines, no vehicles. + +The second, related point, I +wanted to make is that the + +fact that they don't have any +machines is telling you + +something quite important, which +is that these are not + +very sophisticated businesses. + +You're not surprised +to hear that. + +But it is very, very clear that +the average business has + +very little skill involved. + +And to be honest, there's +not a lot of diversity. + +If we look at the top five +businesses, they are things + +like tailoring, a small corner +store, selling snacks on the + +street, embroidering or +stitching clothes and selling + +them as a retail sale, not a +tailor, but someone who retail + +sells garments. + +And I think the last one is-- + +I forget-- carpentry, I think. + +It's like none of these +businesses, except, I think, + +carpentry, possibly, require +huge amounts of skill. + +So they tend to be very low +skilled businesses. + +And this is most businesses. + +So these are not people +who are creating + +very original ideas. + +Indeed, the usual problem that +people write about is most + +people, in the same +neighborhood, + +have the same business. + +They're also selling snacks. + +They're all delivering loads. + +They're all tailors, rather +than a lot of innovation. + +There's no evidence that they're +very creative in what + +business they go into. + +On the other hand, many, many +people own multiple + +businesses. + +That's the other very, +very common fact. + +This is the fraction of +people who get incomes + +from multiple sectors. + +So that's like somebody who was +has farming business but + +also has income from, let's say, +he does some bricklaying + +on the side. + +That's somebody who has +multiple sources. + +And the striking fact +is how common it is. + +In most countries, it's close to +50% of the population have + +income from multiple sources. + +So in other words, they're not +putting all their time, + +available time, into +their own business. + +Why would they not do that? + +If you have a business, in +your family, why aren't + +putting all of your +effort into it? + +Why would we observe this fact, +that most people, many + +people, have multiple business +or multiple occupations? + +AUDIENCE: It might be +comparable, then, to + +[INAUDIBLE]. + +PROFESSOR: Right. + +So, for example, you might +be only able to + +sell one kind of snack. + +And people might want snacks +only, maybe, in + +the evening or something. + +In the morning, you +go to work. + +There's no demand for snacks. + +Or you might sell breakfast, +and you can only sell + +breakfast till 10:00 AM. + +After that, breakfast is over. + +And so you have to find +something to do. + +So one thing could be there's a +natural capacity constraint. + +There's not much demand +for the product. + +And so you can do it for two +hours a day but not for eight + +hours a day. + +Yeah? + +AUDIENCE: There might be +seasonal variations. + +You might be able to a certain +type of business only during + +certain times of the +year, [INAUDIBLE]. + +PROFESSOR: Absolutely. + +So agriculture is one classic +business, where you can work a + +few months of the year, but the +then the rest of the time, + +you don't have irrigation. + +There's nothing to do. + +So you work on something else. + +Yeah? + +AUDIENCE: You might diversify +your portfolio as part of + +[INAUDIBLE]. + +PROFESSOR: Right. + +So you may bear less risk by +having multiple businesses. + +Yeah? + +AUDIENCE: It might be the return +for business is so low, + +that even if you invested more +time and energy into it, it + +wouldn't be worth it. + +PROFESSOR: But why don't you +take the one which is the + +highest return and put all +your time into it? + +AUDIENCE: Maybe I don't +want to [INAUDIBLE]. + +PROFESSOR: Why? + +AUDIENCE: Because even if that +was the highest return, + +[INAUDIBLE]. + +PROFESSOR: But why would you +ever start a second, even + +lower return business? + +If there's one business that +has the highest return, why + +won't you put all your eggs +into that basket? + +AUDIENCE: Diversity. + +PROFESSOR: Yeah, so that's what +she said, which is that + +want to diversify risk. + +What other reason could +you imagine? + +AUDIENCE: It could also be +that you might have one + +business that's really +profitable, let's say, you're + +selling something in the morning +for breakfast, but it + +might be the time-- + +PROFESSOR: Right, that's, +I think, also + +someone brought up. + +AUDIENCE: I think there are like +some businesses which are + +like needlepoint, which +physically hurt you if you do + +it too much. + +People like become blind. + +PROFESSOR: Right, so maybe, just +you don't want to do it + +for too long? + +Another obvious reason. + +AUDIENCE: Didn't they say in the +book that a lot of people + +don't like running their own +businesses, and so they don't + +want to put time into it. + +PROFESSOR: But why would you +do three different ones? + +I'm Asking a simpler question +than the one you're answering, + +which is people seem to do +two or three different + +occupations. + +Why would do two or +three rather than? + +Say I want to work +eight hours. + +Why wouldn't I put all +eight hours into one? + +We've gone through a bunch +of reasons for that. + +AUDIENCE: Is that the marginal +returns decline, especially + +for this type of a business? + +PROFESSOR: So it could be that +the marginal returns on the + +extra piece of effort is low. + +Another possibility that +I think is even more + +straightforward. + +Maybe some businesses +require capital + +and others less capital. + +So you have a certain +amount of capital. + +You put into the capital +intensive business. + +And then use still don't +have some time left. + +So you work in the other one. + +For example, to do needlepoint, +you'll have to + +buy fabric first. + +And you can only afford fabric +that covers half your day. + +And you buy fabric for +half your day. + +You work half your day +on needlepoint. + +The rest of the half of your +day, you have to find + +something else to do. + +So it may just be that you don't +have enough capital to + +make it possible to spend your +whole day working on it. + +So in any case, we do see this +evidence that people don't + +seem to be excessively +committed + +to any single business. + +That has the cost, obviously, +that they're not getting a lot + +of benefits from +specialization. + +They're not learning or +improving very fast, because + +they're doing many, many +things at the same. + +What is striking about this +picture is says, in even rural + +households, a lot of them have +a non-agricultural business. + +So they'll actually, if you look +at how many people have a + +non-agricultural business, like +about a third of them + +have a non-agricultural +business, + +even if they're rural. + +So these are people who +live in rural areas. + +They do farming as one of their +businesses, probably. + +But they also have a second +business, which is + +non-agricultural. + +And that's sort of striking. + +We think of, often, rural areas +in developing countries + +as farmers kind of living +in isolation. + +In fact, most of these +people are in a + +second business as well. + +So the next fact about +businesses of the poor is that + +these businesses are +very fragile. + +So if you look at Mexico, in +85% of the people, the poor + +didn't have a business +in 2002. + +15% had a business. + +By 2005, out of those 15%, only +6% still had a business. + +So 60% of all businesses +just closed. + +So the they're also going +in and out of + +business all the time. + +On the other hand, many other +people started new businesses. + +And you look at the fraction +of the people who retained + +their existing labor force. + +They're just 1.8%. + +So most people either grow their +business or shrink it or + +shut it down. + +So businesses are very, +very fragile. + +It's not that you set up a +business and it lasts forever. + +It's quite a high +risk outcome. + +And this is sort of the answer +to the question, do the poor + +feel entrepreneurial? + +And this is a survey we've done +in many countries, now. + +We always find the say answer. + +You ask people, you have a +child, what occupation do you + +hope for your child to be? + +And we ask it two ways. + +One, we ask them, what +occupation do you hope for + +your child? + +Then you might worry if +you ask that question. + +They might be conditioning +on their condition. + +And so they'd look, you know, +my child he'll never be able + +to do the right kind of +business, because he doesn't + +have enough money +or something. + +So we asked them, if you won a +lottery and you would invest + +in something, what occupation +would your + +child want to be in? + +It doesn't make a difference. + +They always give you the same +answer, which is that they + +don't want to be in business. + +The answer is very, +very clear. + +18% want them to be a private +firm employee, 41% to be a + +non-teaching government +job, and 34% to be + +a government teacher. + +So that's 93% don't want them +to be an entrepreneur. + +So basically, the poor don't +like the idea, at least, of + +their children being +entrepreneurs. + +And it's consistent with +everything else we see, which + +is that they don't seem to +invest all their time in a + +single business. + +Even if they have a business, +they'll put only a part of + +their time into it. + +We saw, earlier, that they don't +try very hard to save + +their way out of debt. + +We saw that when we looked at +the fruit vendors, that they + +were not saving a lot and tried +to get out of debt. + +So it seems like they don't seem +to be hugely committed to + +growing their business. + +There's no evidence. + +And we see the businesses +don't grow. + +Many of them shrink +or shut down. + +Very few of them actually +add an employee. + +At best, these business +are always small. + +They stay small or +they shutdown. + +They rarely grow. + +So there is no evidence that the +poor are actually dynamic + +entrepreneurs, in the sense +that they are looking for + +opportunities to grow their +business all the time. + +Now, that doesn't mean that +there are not a million + +dynamic entrepreneurs +among the poor. + +One should not confuse the +statement that the average + +poor person is not a dynamic +entrepreneur with the + +statement that there +are no dynamic + +entrepreneurs among the poor. + +There may be exactly the same +fraction of dynamic + +entrepreneurs among the poor +as there are among MIT + +students, for all I know. + +It's just most people are +not cut out to dynamic + +entrepreneurs. + +And the poor, maybe, just +like everybody else, + +they don't like risk. + +They don't like the idea of +worrying about all of the + +problems that running +business has. + +They like a steady job. + +And then a few people really +like being an entrepreneur. + +I don't know that this makes +them any different from + +anybody else. + +It just says that they're not. + +You see a huge +over-representation of the + +poor among entrepreneurs. + +That doesn't mean that this is +what the poor want to be. + +It's not that they're +entrepreneurial in some + +natural sense. + +They're not that they want +to be an entrepreneur. + +They're an entrepreneur for some +other reason we'll come + +to in a minute. + +None of this evidence seems to +suggest that they're dying to + +be entrepreneurs and to +grow their businesses. + +That doesn't mean that there +aren't some who are. + +There's this story that you saw +in the microfinance movie + +of some woman who started +as hair collector. + +Remember this person? + +And she's now a hair tycoon. + +And they exist, people like +that, everywhere in the world. + +I'm even willing to believe +that there are as many + +genuinely entrepreneurial people +among the poor as there + +are among anybody else. + +But that's a very different +sentence from saying that most + +poor people have businesses +because they're + +entrepreneurial. + +Because they're so massively +overrepresented. + +They're really unlikely people +to be entrepreneurs. + +So if they are entrepreneurs, +it's not because + +they want to be. + +This is all consistent with the +fact that, if you look at + +these businesses, they're +not really attractive + +economically. + +So one place where we have +detailed data, we could + +actually calculate how much +revenues these businesses were + +making, calculate profits. + +Now a key part of the +profit calculation-- + +remember, almost none of these +firms have employees. + +So you have to evaluate the +time spent by the owner in + +running the business. + +Somehow, how do you +price that? + +So you price that +at minimum wage. + +These businesses lose money. + +So if I went out and worked at +minimum wage, I would make + +more money than if I did this +business and spent all the + +time I'm spending +in the business. + +Now, I'm not necessarily +working as hard in the + +business as I would be working +in other things. + +But it isn't the case that +I'm making lots of money. + +I think this is a pattern that +people have noticed. + +Now, here's a puzzle. + +I just said they don't +make a lot of money. + +They're not very profitable, +these business. + +Before, I've also told +you that they + +pay very high interest. + +So they must be generating +an extra $1. + +They must be generating +at least that much. + +So if I'm paying 60% interest, +$1 must be generating more + +than $0.60. + +If I'm investing $1 and then +paying 60% interest, that $1 + +must be generating +more than $0.60. + +How do those two facts +fit with each other? + +I said, A, they're not +very profitable. + +B, the marginal $1 must be +making a high return, because + +otherwise they wouldn't be +investing their marginal $1. + +You won't borrow money at 60% +unless you can cover 60%. + +So we know that they're +making lots of money. + +Yeah? + +AUDIENCE: This talked a +lot about in the book. + +But basically, there's two +different types of return. + +One is marginal returns, +[INAUDIBLE] + +where an extra $1 spent, +what's their return. + +The other's the total return. + +For a lot of these businesses, +there is a point, early on, + +with this very high, marginal +return, and then it really + +levels off. + +So that's what you run into, +where it's possible that, if + +you have a very small +business, like the + +example in the book. + +Let's say you have a shop, but +you really can't put anything + +on the shelves. + +If you spend an extra $20, you +can actually have some candy + +on the shelves, then that +will produce very + +high marginal returns. + +But if you spend $300 and have +a lot of inventory, you might + +have to hire another employee. + +There's risk of stuff spoiling, + +et cetera, et cetera. + +PROFESSOR: So I think that's +absolutely right. + +But I was making an even simpler +point, here, which is + +that think of that business. + +The person who set up a shop. + +You invest your time +into the shop. + +And you invest the space. + +You invest the shelves. + +You invest the inventory. + +Then you start selling. + +So in particular, your time +is a fixed investment. + +Because you have now decided +that instead of working + +outside, I'm going to +stay in the shop. + +So you need to cover. + +To become profitable, you need +to cover your own daily wage. + +Let's say you make $2 a day. + +Then even if you made a total +of $2 a day by selling, you + +would have just covered +your wage. + +Then you recover your +inventory, your + +capital cost, et cetera. + +So unless you operate at a high +enough scale, you're not + +going to cover your time. + +And so one of the problems +is these people are often + +operating at a very +small scale. + +So they rarely manage +to cover their cost. + +But then why don't these +people just grow their + +businesses? + +Maybe if they're not making a +lot of money, because they + +have to cover their fixed cost, +then why not just keep + +investing till you make +a lot of money. + +Your marginal returns are high, +so you could invest more + +and make more money. + +And then the answer is, your +marginal are high, but not + +high for a very wide range. + +So they start falling +fast as well. + +So this is the picture +that is in the book. + +And it's worth, probably, +understanding that picture. + +So that picture, it tells a +story of two technologies. + +There's one technology which is +gives you a high return but + +quickly flattens off. + +And if that was the only +technology in the world, then + +we would not observe +any large funds. + +Because that's a technology +which stops becoming + +profitable after a point, +very quickly. + +But there's another technology, +which starts way + +to the right of that. + +And that technology is only +profitable if you invest. + +So what that curve says +is that there is two + +technologies. + +Production from technology two +is lower than production for + +technology one until you cross +a particular point. + +So you need to make enough +investment to make that + +profitable. + +So you're going to buy a machine +which produces a lot + +of garments. + +But if you can't buy the cloth +that goes with the machine, + +there's no point in buying +the machine. + +You're going to lose money for +sure, because you have nothing + +to use the machine with. + +Garments need a machine +and they need cloth. + +And you have only money for the +machine, then you should + +not buy the machine. + +You should buy the machine +only if you can buy the + +machine and buy the cloth. + +So there that are more +profitable technologies and + +less profitable technologies. + +But the disadvantage of the +more profitable technology + +turns out to be that you need +to invest enough in them to + +make money. + +So the problem is that the poor +are caught between a kind + +of a rock and a hard place, +which is that they can't + +really get up to the +level at which they + +would make real money. + +Because that technology is just +too expensive for them. + +They don't have that +much money. + +The technology that they can +access has very fast + +diminishing returns. + +So that one also is not +worth growing a lot. + +So that's the sense in which +they're between a rock and a + +hard place. + +They can't grow the technology +fast enough. + +The one that they have, +they can't grow. + +And the one that can grow, +they can't have. + +And that's what this +picture is about. + +If this is what the world looks +like, then the poor are + +stuck at a point, like M, and +the rich are stuck at point + +like that second +ball up there. + +So the poor are stuck, because +the technology that has growth + +is not available to them. + +And the one that's available +to them does not + +have growth in it. + +So there's no point in their +putting a lot of effort into + +growing their technology, +because they're really not + +going to make a lot of +money either way. + +That would explain why they +don't really want to be + +entrepreneurs, because they know +that they're never going + +to get very far in +this process. + +So then that leaves us with +the last slide, well, + +actually, one slide +that suggests that + +this picture is right. + +There was this experiment in Sri +Lanka, where people were + +given, randomly, either $250 +or $500 for investing. + +And this was just a gift. + +The World Bank, basically, did +this experiment, where it went + +to people and said, +here's $250. + +These were all small +businessmen. + +Use it in your business or +do something with it. + +And some people, they +offered $500. + +It's kind of nice experiment +to do, because you can find + +out what's the effect on getting +money on people's + +investment. + +And strikingly, if you +give $250, you get + +high marginal returns. + +So these people who get $250, +they invest $250, and they + +make about 60% a year on that. + +So that's pretty good returns. + +On the other hand, if you give +them $500, they don't invest + +the second $250. + +They just use it for repairing +their home. + +So they don't believe that the +second $500 are going to grow + +their business that much more. + +They believe that there's +diminishing returns. + +That's why they don't +invest it. + +So basically, the poor seem to +be acting as if they also + +believe exactly that picture, +that they have high returns on + +the first $250 but not +on the second $250. + +Yeah? + +AUDIENCE: So [INAUDIBLE] + +they just save up enough money +or take a loan out so that you + +can achieve or you can jump +the curve and buy the + +technology. + +PROFESSOR: Absolutely. + +AUDIENCE: So it's like, +technically, giving loans to + +small businesses should work. + +PROFESSOR: Well, it depends +on how big the loan is. + +I think the problem is that +the jump is not at $500. + +The jump is at $10,000. + +So none of the loans they are +being offered allow them to + +make that jump. + +That's the problem. + +AUDIENCE: And they're +still too small to + +go to a normal bank? + +PROFESSOR: Yeah. + +that then brings us to the final +question, which is, if + +this is all not such +a great deal, + +why are they in business? + +Yeah, go ahead. + +AUDIENCE: Because +they have to be. + +PROFESSOR: Yeah. + +One is that they have to be. + +There's a vicious cycle, here. + +Suppose no one can create a +business that's big enough to + +hire employees. + +Then I can never be +an employee in + +somebody else's firm. + +What else can I do? + +I can start my own business, +which can't hire anybody. + +So if nobody is creating +businesses which have + +employees, then, in a +sense, I'm stuck. + +I can't get a job, because +nobody else is + +creating those jobs. + +But if nobody else is creating +those jobs, then I can't + +really work for anybody else. + +But I still have to earn a +living, so I go and find my + +own thing to do. + +So I think the primary reason +why you have a lot of + +entrepreneurs is because no +entrepreneur is big enough to + +hire the others. + +So everybody's an +entrepreneur, a + +mini-entrepreneur. + +Nobody gets to the scale where +they can hire others. + +And therefore, everybody's +kind of stuck. + +So if I start a business that +hires 10 people, then that + +stops 9 other people from +being an entrepreneur. + +That's one reason. + +A second reason has to +do with flexibility. + +I think a lot of poor +people don't have + +access to social services. + +So if I have to have childcare, +pay for childcare, + +I'm never going to able to +afford my business, because + +childcare is too expensive. + +So if I have to go out and get +a job, which is 9-to-5, and I + +have to work all +the time, who's + +going to provide childcare? + +So often, they choose businesses +which are designed + +to work well with childcare. + +Like I took a snack +making business. + +Why? + +Because I can do it at home. + +I make the snacks at home. + +And then I go out to +sell for two hours. + +At that time, I take +my child with me. + +And then I bring +the child back. + +And that way, I don't ever +have to deal with the + +childcare issue. + +So flexibility is +a second one. + +The third and most +worrying one-- + +and microcredit makes me +worry about this most-- + +is whether or not a lot of men +are very enthusiastic for the + +wives to work even harder. + +So they feel that, you know, +I'm working at a job. + +I would like my wife +to work harder. + +And the way they get their wives +to work harder is by + +making them start a business. + +So I don't know whether +microcredit is necessarily + +wonderful for all +of these women. + +I think that, historically, men +have found it difficult to + +understand that women, even +though they don't go out to + +work, actually have to work. + +They have like cooking +and cleaning + +dishes and washing up. + +They're all hard work. + +And if you think that that's a +problem in the US, now, then + +you can imagine in a lot of +developing countries, it's + +even more of a problem. + +So it may well be that a lot of +men are under the illusion + +that their wives are idle. + +And that they are very willing, +therefore, to start a + +business for them, so they can +work a little harder and add + +to the family pie. + +So I don't know how much of +these businesses are a result + +of that, rather than any desire +to start a business. + +Comments, questions? + +So just to close this whole +thing, I think the key policy + +question, that we don't know the +answer to, is how to not + +get more businesses, +but more businesses + +that hire other people. + +That's the key policy +question we haven't + +managed to solve yet. + +And it's an absolutely central +policy question for most + +developing countries to figure +out how to get not + +micro-businesses but +small businesses. + +And this is often called the +missing middle problem. + +In many countries, in poor +countries, you'll find that + +there are many micro-businesses +and some + +large businesses, but not +enough middle-sized + +businesses. + +So that's the policy problem +that many, many countries are + +wrestling with. + +And it's one that, I think, +we haven't yet got a + +very good handle on. + +But it's something to think +about is how to + +generate those jobs. + +Yeah? + +AUDIENCE: So specifically in +developed countries, then, + +what provides the capital for +the middle businesses? + +PROFESSOR: So for one, +the state does a lot. + +Like in the US, for example, +there's a Community + +Reinvestment Act, which means +that banks are required to + +provide a certain fraction of +their loans to the community + +where they are raising +the savings. + +So the CRA forces them, then, +to finance local businesses. + +And so there is a lot of +intervention, even in a + +country as uninterventionist +as the US, to help small + +businesses set up. + +This CRA is a very +good example. + +The Small Business +Administration is huge in the + +US, by the way. + +And they provide all kinds of +help to small businesses, + +including capital, including +guarantees. + +They give a lot of +loan guarantees. + +Even the US, which is one +of the world's least + +interventionist countries, +tends to be very + +interventionist when it comes to +promoting small businesses. + +That's probably the direction +that policy needs to go in + +developing countries. + +But it's something we +know less about. + +OK. + +Thank you. \ No newline at end of file diff --git a/yHzpj_MDOdk.txt b/yHzpj_MDOdk.txt new file mode 100644 index 0000000000000000000000000000000000000000..5dcc3a8bc527f35e9087eece301377586e0e7f5c --- /dev/null +++ b/yHzpj_MDOdk.txt @@ -0,0 +1,12283 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so I'm going to describe the basic + + align:start position:0% +so I'm going to describe the basic + + + align:start position:0% +so I'm going to describe the basic +classification of solar cell + + align:start position:0% +classification of solar cell + + + align:start position:0% +classification of solar cell +characterization methods and then I'll + + align:start position:0% +characterization methods and then I'll + + + align:start position:0% +characterization methods and then I'll +describe some of the characterization + + align:start position:0% +describe some of the characterization + + + align:start position:0% +describe some of the characterization +tools that are used to measure JSC + + align:start position:0% +tools that are used to measure JSC + + + align:start position:0% +tools that are used to measure JSC +losses and other tools that are used to + + align:start position:0% +losses and other tools that are used to + + + align:start position:0% +losses and other tools that are used to +measure vo C and fill factor losses + + align:start position:0% +measure vo C and fill factor losses + + + align:start position:0% +measure vo C and fill factor losses +right so getting a sense of the lay of + + align:start position:0% +right so getting a sense of the lay of + + + align:start position:0% +right so getting a sense of the lay of +the land let me ask you how would you + + align:start position:0% +the land let me ask you how would you + + + align:start position:0% +the land let me ask you how would you +characterize how would you create a + + align:start position:0% +characterize how would you create a + + + align:start position:0% +characterize how would you create a +taxonomy of solar cell characterization + + align:start position:0% +taxonomy of solar cell characterization + + + align:start position:0% +taxonomy of solar cell characterization +techniques those of you who might have a + + align:start position:0% +techniques those of you who might have a + + + align:start position:0% +techniques those of you who might have a +little bit more experience might + + align:start position:0% +little bit more experience might + + + align:start position:0% +little bit more experience might +actually have used a few + + align:start position:0% +actually have used a few + + + align:start position:0% +actually have used a few +characterization techniques in your + + align:start position:0% +characterization techniques in your + + + align:start position:0% +characterization techniques in your +laboratories what taxonomy would you use + + align:start position:0% +laboratories what taxonomy would you use + + + align:start position:0% +laboratories what taxonomy would you use +how would you slice the pie of all of + + align:start position:0% +how would you slice the pie of all of + + + align:start position:0% +how would you slice the pie of all of +these characterization techniques go + + align:start position:0% + + + + align:start position:0% + +what are what are ways to divide the + + align:start position:0% +what are what are ways to divide the + + + align:start position:0% +what are what are ways to divide the +characterization universe into distinct + + align:start position:0% +characterization universe into distinct + + + align:start position:0% +characterization universe into distinct +groupings how about we start overhead + + align:start position:0% +groupings how about we start overhead + + + align:start position:0% +groupings how about we start overhead +yeah yeah okay so we can describe based + + align:start position:0% +yeah yeah okay so we can describe based + + + align:start position:0% +yeah yeah okay so we can describe based +on the economic variables right like + + align:start position:0% +on the economic variables right like + + + align:start position:0% +on the economic variables right like +efficiency and then with an efficiency + + align:start position:0% +efficiency and then with an efficiency + + + align:start position:0% +efficiency and then with an efficiency +JSC vo C fill factor mechanical yield + + align:start position:0% +JSC vo C fill factor mechanical yield + + + align:start position:0% +JSC vo C fill factor mechanical yield +reliability right these are all + + align:start position:0% +reliability right these are all + + + align:start position:0% +reliability right these are all +parameters that can lump into a cost + + align:start position:0% +parameters that can lump into a cost + + + align:start position:0% +parameters that can lump into a cost +model and ultimately impact the the cost + + align:start position:0% +model and ultimately impact the the cost + + + align:start position:0% +model and ultimately impact the the cost +dollars per watt let's say if a PV panel + + align:start position:0% +dollars per watt let's say if a PV panel + + + align:start position:0% +dollars per watt let's say if a PV panel +excellent so we can describe it based on + + align:start position:0% +excellent so we can describe it based on + + + align:start position:0% +excellent so we can describe it based on +performance if we dive into performance + + align:start position:0% +performance if we dive into performance + + + align:start position:0% +performance if we dive into performance +a little more what are some of the + + align:start position:0% +a little more what are some of the + + + align:start position:0% +a little more what are some of the +properties that affect performance we + + align:start position:0% +properties that affect performance we + + + align:start position:0% +properties that affect performance we +have electrical properties optical + + align:start position:0% +have electrical properties optical + + + align:start position:0% +have electrical properties optical +properties mechanical right thermal and + + align:start position:0% +properties mechanical right thermal and + + + align:start position:0% +properties mechanical right thermal and +so forth so we can break up + + align:start position:0% +so forth so we can break up + + + align:start position:0% +so forth so we can break up +characterization techniques space in the + + align:start position:0% +characterization techniques space in the + + + align:start position:0% +characterization techniques space in the +properties that they probe and we can + + align:start position:0% +properties that they probe and we can + + + align:start position:0% +properties that they probe and we can +also character right where you can + + align:start position:0% +also character right where you can + + + align:start position:0% +also character right where you can +create a taxonomy of characterization + + align:start position:0% +create a taxonomy of characterization + + + align:start position:0% +create a taxonomy of characterization +techniques based on how fast they are + + align:start position:0% +techniques based on how fast they are + + + align:start position:0% +techniques based on how fast they are +whether it's something that you have to + + align:start position:0% +whether it's something that you have to + + + align:start position:0% +whether it's something that you have to +sit around and twiddle your thumbs for a + + align:start position:0% +sit around and twiddle your thumbs for a + + + align:start position:0% +sit around and twiddle your thumbs for a +half hour two hours to get done or + + align:start position:0% +half hour two hours to get done or + + + align:start position:0% +half hour two hours to get done or +whether it's something that gets done in + + align:start position:0% +whether it's something that gets done in + + + align:start position:0% +whether it's something that gets done in +ten milliseconds of which there are + + align:start position:0% +ten milliseconds of which there are + + + align:start position:0% +ten milliseconds of which there are +several characterization techniques what + + align:start position:0% +several characterization techniques what + + + align:start position:0% +several characterization techniques what +would the 10 millisecond variety enable + + align:start position:0% +would the 10 millisecond variety enable + + + align:start position:0% +would the 10 millisecond variety enable +you to do in a manufacturing environment + + align:start position:0% +you to do in a manufacturing environment + + + align:start position:0% +you to do in a manufacturing environment +yeah sort them test them measure them + + align:start position:0% +yeah sort them test them measure them + + + align:start position:0% +yeah sort them test them measure them +every single cell coming through so you + + align:start position:0% +every single cell coming through so you + + + align:start position:0% +every single cell coming through so you +might have a barcode like one of those + + align:start position:0% +might have a barcode like one of those + + + align:start position:0% +might have a barcode like one of those +fancy two-dimensional barcodes laser + + align:start position:0% +fancy two-dimensional barcodes laser + + + align:start position:0% +fancy two-dimensional barcodes laser +marked on each single wafer going + + align:start position:0% +marked on each single wafer going + + + align:start position:0% +marked on each single wafer going +through your line so you can trace it + + align:start position:0% +through your line so you can trace it + + + align:start position:0% +through your line so you can trace it +back in your mes system all the way back + + align:start position:0% +back in your mes system all the way back + + + align:start position:0% +back in your mes system all the way back +to the crystal that will + + align:start position:0% +to the crystal that will + + + align:start position:0% +to the crystal that will +groan or from the thin film growth + + align:start position:0% +groan or from the thin film growth + + + align:start position:0% +groan or from the thin film growth +chamber where it was deposited so yes + + align:start position:0% +chamber where it was deposited so yes + + + align:start position:0% +chamber where it was deposited so yes +you have in line and shall we say say + + align:start position:0% +you have in line and shall we say say + + + align:start position:0% +you have in line and shall we say say +the the in line characterization + + align:start position:0% +the the in line characterization + + + align:start position:0% +the the in line characterization +techniques and what are called off line + + align:start position:0% +techniques and what are called off line + + + align:start position:0% +techniques and what are called off line +characterization techniques which tend + + align:start position:0% +characterization techniques which tend + + + align:start position:0% +characterization techniques which tend +to be lower throughput you can think of + + align:start position:0% +to be lower throughput you can think of + + + align:start position:0% +to be lower throughput you can think of +the in line characterization techniques + + align:start position:0% +the in line characterization techniques + + + align:start position:0% +the in line characterization techniques +as as being in the line of the + + align:start position:0% +as as being in the line of the + + + align:start position:0% +as as being in the line of the +manufacturing environment and the off + + align:start position:0% +manufacturing environment and the off + + + align:start position:0% +manufacturing environment and the off +line is being those techniques that are + + align:start position:0% +line is being those techniques that are + + + align:start position:0% +line is being those techniques that are +sitting in your laboratory right waiting + + align:start position:0% +sitting in your laboratory right waiting + + + align:start position:0% +sitting in your laboratory right waiting +to be used in in the R&D lab which might + + align:start position:0% +to be used in in the R&D lab which might + + + align:start position:0% +to be used in in the R&D lab which might +be next door to the to the manufacturing + + align:start position:0% +be next door to the to the manufacturing + + + align:start position:0% +be next door to the to the manufacturing +line device performance metric affected + + align:start position:0% +line device performance metric affected + + + align:start position:0% +line device performance metric affected +that addresses the efficiency point up + + align:start position:0% +that addresses the efficiency point up + + + align:start position:0% +that addresses the efficiency point up +here and then buy property tests at + + align:start position:0% +here and then buy property tests at + + + align:start position:0% +here and then buy property tests at +electrical structural optical mechanical + + align:start position:0% +electrical structural optical mechanical + + + align:start position:0% +electrical structural optical mechanical +so if you talk to somebody who works in + + align:start position:0% +so if you talk to somebody who works in + + + align:start position:0% +so if you talk to somebody who works in +a PV company she will likely give you a + + align:start position:0% +a PV company she will likely give you a + + + align:start position:0% +a PV company she will likely give you a +breakdown based on number three right + + align:start position:0% +breakdown based on number three right + + + align:start position:0% +breakdown based on number three right +here okay these are the techniques that + + align:start position:0% +here okay these are the techniques that + + + align:start position:0% +here okay these are the techniques that +we have in our inspection system and + + align:start position:0% +we have in our inspection system and + + + align:start position:0% +we have in our inspection system and +those are the techniques that I have + + align:start position:0% +those are the techniques that I have + + + align:start position:0% +those are the techniques that I have +over there in the R&D lab if you talk to + + align:start position:0% +over there in the R&D lab if you talk to + + + align:start position:0% +over there in the R&D lab if you talk to +somebody who is giving a fundamental + + align:start position:0% +somebody who is giving a fundamental + + + align:start position:0% +somebody who is giving a fundamental +course of material science they're + + align:start position:0% +course of material science they're + + + align:start position:0% +course of material science they're +likely to pick part number one way up + + align:start position:0% +likely to pick part number one way up + + + align:start position:0% +likely to pick part number one way up +there and give you the breakdown based + + align:start position:0% +there and give you the breakdown based + + + align:start position:0% +there and give you the breakdown based +on the properties that are probed I'm + + align:start position:0% +on the properties that are probed I'm + + + align:start position:0% +on the properties that are probed I'm +going to opt for number two today in + + align:start position:0% +going to opt for number two today in + + + align:start position:0% +going to opt for number two today in +lecture not because it's any better or + + align:start position:0% +lecture not because it's any better or + + + align:start position:0% +lecture not because it's any better or +worse than all the others but just + + align:start position:0% +worse than all the others but just + + + align:start position:0% +worse than all the others but just +because that's the metric that we care + + align:start position:0% +because that's the metric that we care + + + align:start position:0% +because that's the metric that we care +about right now is we're trying to probe + + align:start position:0% +about right now is we're trying to probe + + + align:start position:0% +about right now is we're trying to probe +dollars per watt + + align:start position:0% +dollars per watt + + + align:start position:0% +dollars per watt +that's relates to our quiz and our + + align:start position:0% +that's relates to our quiz and our + + + align:start position:0% +that's relates to our quiz and our +homework but also relates to the + + align:start position:0% +homework but also relates to the + + + align:start position:0% +homework but also relates to the +ultimate economic driver solar so we + + align:start position:0% +ultimate economic driver solar so we + + + align:start position:0% +ultimate economic driver solar so we +have will keep this in mind that we + + align:start position:0% +have will keep this in mind that we + + + align:start position:0% +have will keep this in mind that we +might need to ferret out references for + + align:start position:0% +might need to ferret out references for + + + align:start position:0% +might need to ferret out references for +the different techniques in different + + align:start position:0% +the different techniques in different + + + align:start position:0% +the different techniques in different +textbooks or different papers based on + + align:start position:0% +textbooks or different papers based on + + + align:start position:0% +textbooks or different papers based on +whether they're probing electrical + + align:start position:0% +whether they're probing electrical + + + align:start position:0% +whether they're probing electrical +structural optical mechanical properties + + align:start position:0% +structural optical mechanical properties + + + align:start position:0% +structural optical mechanical properties +of our solar cells but we're going to be + + align:start position:0% +of our solar cells but we're going to be + + + align:start position:0% +of our solar cells but we're going to be +focused on efficiency short circuit + + align:start position:0% +focused on efficiency short circuit + + + align:start position:0% +focused on efficiency short circuit +current open circuit voltage fill factor + + align:start position:0% +current open circuit voltage fill factor + + + align:start position:0% +current open circuit voltage fill factor +so let's go ahead and dive into that we + + align:start position:0% +so let's go ahead and dive into that we + + + align:start position:0% +so let's go ahead and dive into that we +are going to first start with techniques + + align:start position:0% +are going to first start with techniques + + + align:start position:0% +are going to first start with techniques +to measure JSC or short-circuit current + + align:start position:0% +to measure JSC or short-circuit current + + + align:start position:0% +to measure JSC or short-circuit current +losses and some of these slides are + + align:start position:0% +losses and some of these slides are + + + align:start position:0% +losses and some of these slides are +going to be repeats and the reason + + align:start position:0% +going to be repeats and the reason + + + align:start position:0% +going to be repeats and the reason +they're repeats is because the first + + align:start position:0% +they're repeats is because the first + + + align:start position:0% +they're repeats is because the first +time you saw it okay you sort of kind of + + align:start position:0% +time you saw it okay you sort of kind of + + + align:start position:0% +time you saw it okay you sort of kind of +got it you went into the lab made your + + align:start position:0% +got it you went into the lab made your + + + align:start position:0% +got it you went into the lab made your +devices tested them and now all of a + + align:start position:0% +devices tested them and now all of a + + + align:start position:0% +devices tested them and now all of a +sudden you have a much I would say much + + align:start position:0% +sudden you have a much I would say much + + + align:start position:0% +sudden you have a much I would say much +stronger background with which to + + align:start position:0% +stronger background with which to + + + align:start position:0% +stronger background with which to +understand we're going to start by + + align:start position:0% +understand we're going to start by + + + align:start position:0% +understand we're going to start by +discussing the optical components just + + align:start position:0% +discussing the optical components just + + + align:start position:0% +discussing the optical components just +very briefly + + align:start position:0% +very briefly + + + align:start position:0% +very briefly +in spectral response minority carrier + + align:start position:0% +in spectral response minority carrier + + + align:start position:0% +in spectral response minority carrier +diffusion length revisiting some of + + align:start position:0% +diffusion length revisiting some of + + + align:start position:0% +diffusion length revisiting some of +these concepts that we already seen but + + align:start position:0% +these concepts that we already seen but + + + align:start position:0% +these concepts that we already seen but +now with the benefit of having all of + + align:start position:0% +now with the benefit of having all of + + + align:start position:0% +now with the benefit of having all of +our background knowledge + + align:start position:0% +our background knowledge + + + align:start position:0% +our background knowledge +spectrophotometer majors specular and + + align:start position:0% +spectrophotometer majors specular and + + + align:start position:0% +spectrophotometer majors specular and +diffuse reflectance and transmission + + align:start position:0% +diffuse reflectance and transmission + + + align:start position:0% +diffuse reflectance and transmission +alright let's let's break that down + + align:start position:0% +alright let's let's break that down + + + align:start position:0% +alright let's let's break that down +specular reflectance spec your mirror + + align:start position:0% +specular reflectance spec your mirror + + + align:start position:0% +specular reflectance spec your mirror +Latin right so specular reflectance + + align:start position:0% +Latin right so specular reflectance + + + align:start position:0% +Latin right so specular reflectance +means light comes in and out pretty much + + align:start position:0% +means light comes in and out pretty much + + + align:start position:0% +means light comes in and out pretty much +at the same angle relative to the + + align:start position:0% +at the same angle relative to the + + + align:start position:0% +at the same angle relative to the +surface normal so if you come in from + + align:start position:0% +surface normal so if you come in from + + + align:start position:0% +surface normal so if you come in from +here it's going to bounce out like there + + align:start position:0% +here it's going to bounce out like there + + + align:start position:0% +here it's going to bounce out like there +right the same angle relative to the + + align:start position:0% +right the same angle relative to the + + + align:start position:0% +right the same angle relative to the +surface normal diffuse reflectance means + + align:start position:0% +surface normal diffuse reflectance means + + + align:start position:0% +surface normal diffuse reflectance means +that if you shine light in a certain + + align:start position:0% +that if you shine light in a certain + + + align:start position:0% +that if you shine light in a certain +angle it's going to reflect back not + + align:start position:0% +angle it's going to reflect back not + + + align:start position:0% +angle it's going to reflect back not +necessarily at that angle I could have a + + align:start position:0% +necessarily at that angle I could have a + + + align:start position:0% +necessarily at that angle I could have a +distribution limbering scatterer might + + align:start position:0% +distribution limbering scatterer might + + + align:start position:0% +distribution limbering scatterer might +qualify and reflecting some transmission + + align:start position:0% +qualify and reflecting some transmission + + + align:start position:0% +qualify and reflecting some transmission +okay we talked about the different + + align:start position:0% +okay we talked about the different + + + align:start position:0% +okay we talked about the different +optical losses of a solar cell material + + align:start position:0% +optical losses of a solar cell material + + + align:start position:0% +optical losses of a solar cell material +reflectance means that light comes back + + align:start position:0% +reflectance means that light comes back + + + align:start position:0% +reflectance means that light comes back +off the surface transmission means that + + align:start position:0% +off the surface transmission means that + + + align:start position:0% +off the surface transmission means that +light did not get absorbed so it went + + align:start position:0% +light did not get absorbed so it went + + + align:start position:0% +light did not get absorbed so it went +through the material and didn't get + + align:start position:0% +through the material and didn't get + + + align:start position:0% +through the material and didn't get +absorbed that is an optical loss as well + + align:start position:0% +absorbed that is an optical loss as well + + + align:start position:0% +absorbed that is an optical loss as well +so the spectrophotometer is useful for + + align:start position:0% +so the spectrophotometer is useful for + + + align:start position:0% +so the spectrophotometer is useful for +measuring these different loss + + align:start position:0% +measuring these different loss + + + align:start position:0% +measuring these different loss +mechanisms and it can tease apart the + + align:start position:0% +mechanisms and it can tease apart the + + + align:start position:0% +mechanisms and it can tease apart the +specular from the diffuse reflectance + + align:start position:0% +specular from the diffuse reflectance + + + align:start position:0% +specular from the diffuse reflectance +giving you some indication some idea of + + align:start position:0% +giving you some indication some idea of + + + align:start position:0% +giving you some indication some idea of +how the surface is behaving and what you + + align:start position:0% +how the surface is behaving and what you + + + align:start position:0% +how the surface is behaving and what you +might do to improve it so the + + align:start position:0% +might do to improve it so the + + + align:start position:0% +might do to improve it so the +spectrophotometer is useful in that + + align:start position:0% +spectrophotometer is useful in that + + + align:start position:0% +spectrophotometer is useful in that +regard in terms of increasing absorption + + align:start position:0% +regard in terms of increasing absorption + + + align:start position:0% +regard in terms of increasing absorption +we talked about various methods to + + align:start position:0% +we talked about various methods to + + + align:start position:0% +we talked about various methods to +increase absorption those who attended + + align:start position:0% +increase absorption those who attended + + + align:start position:0% +increase absorption those who attended +the Eloi a bloody talk heard + + align:start position:0% +the Eloi a bloody talk heard + + + align:start position:0% +the Eloi a bloody talk heard +about many more the goal here is + + align:start position:0% +about many more the goal here is + + + align:start position:0% +about many more the goal here is +essentially to increase the optical path + + align:start position:0% +essentially to increase the optical path + + + align:start position:0% +essentially to increase the optical path +length by texturing your surface for + + align:start position:0% +length by texturing your surface for + + + align:start position:0% +length by texturing your surface for +instance the physical thickness can + + align:start position:0% +instance the physical thickness can + + + align:start position:0% +instance the physical thickness can +remain very low and again just to + + align:start position:0% +remain very low and again just to + + + align:start position:0% +remain very low and again just to +refresh ourselves if we decrease the + + align:start position:0% +refresh ourselves if we decrease the + + + align:start position:0% +refresh ourselves if we decrease the +thickness of our devices but managed to + + align:start position:0% +thickness of our devices but managed to + + + align:start position:0% +thickness of our devices but managed to +have very good light trapping what + + align:start position:0% +have very good light trapping what + + + align:start position:0% +have very good light trapping what +happens to our excess carrier density it + + align:start position:0% +happens to our excess carrier density it + + + align:start position:0% +happens to our excess carrier density it +goes up right because now we have more + + align:start position:0% +goes up right because now we have more + + + align:start position:0% +goes up right because now we have more +carriers being generated in a smaller + + align:start position:0% +carriers being generated in a smaller + + + align:start position:0% +carriers being generated in a smaller +volume so the carrier density increases + + align:start position:0% +volume so the carrier density increases + + + align:start position:0% +volume so the carrier density increases +and as the carrier density goes up that + + align:start position:0% +and as the carrier density goes up that + + + align:start position:0% +and as the carrier density goes up that +means the separation of the quasi Fermi + + align:start position:0% +means the separation of the quasi Fermi + + + align:start position:0% +means the separation of the quasi Fermi +energies increases which means the + + align:start position:0% +energies increases which means the + + + align:start position:0% +energies increases which means the +maximum voltage extractable from our + + align:start position:0% +maximum voltage extractable from our + + + align:start position:0% +maximum voltage extractable from our +device increases as well so there's a + + align:start position:0% +device increases as well so there's a + + + align:start position:0% +device increases as well so there's a +strong push right now in the field to go + + align:start position:0% +strong push right now in the field to go + + + align:start position:0% +strong push right now in the field to go +to thinner and thinner devices that also + + align:start position:0% +to thinner and thinner devices that also + + + align:start position:0% +to thinner and thinner devices that also +has the added benefit economically of + + align:start position:0% +has the added benefit economically of + + + align:start position:0% +has the added benefit economically of +using + + align:start position:0% +using + + + align:start position:0% +using +material so we want to decrease the + + align:start position:0% +material so we want to decrease the + + + align:start position:0% +material so we want to decrease the +thickness by improving our optical + + align:start position:0% +thickness by improving our optical + + + align:start position:0% +thickness by improving our optical +trapping our light trapping the another + + align:start position:0% +trapping our light trapping the another + + + align:start position:0% +trapping our light trapping the another +benefit is that allows carriers to be + + align:start position:0% +benefit is that allows carriers to be + + + align:start position:0% +benefit is that allows carriers to be +absorbed closer to the junction which + + align:start position:0% +absorbed closer to the junction which + + + align:start position:0% +absorbed closer to the junction which +increases their probability of + + align:start position:0% +increases their probability of + + + align:start position:0% +increases their probability of +collection and we talked about this + + align:start position:0% +collection and we talked about this + + + align:start position:0% +collection and we talked about this +during the very beginning of class how + + align:start position:0% +during the very beginning of class how + + + align:start position:0% +during the very beginning of class how +you might texture your surface but now + + align:start position:0% +you might texture your surface but now + + + align:start position:0% +you might texture your surface but now +we actually saw it in producing + + align:start position:0% +we actually saw it in producing + + + align:start position:0% +we actually saw it in producing +ourselves so this is an example an SEM + + align:start position:0% +ourselves so this is an example an SEM + + + align:start position:0% +ourselves so this is an example an SEM +image of textured silicon in that + + align:start position:0% +image of textured silicon in that + + + align:start position:0% +image of textured silicon in that +particular case this was an alkali edge + + align:start position:0% +particular case this was an alkali edge + + + align:start position:0% +particular case this was an alkali edge +on a single crystalline sample probably + + align:start position:0% +on a single crystalline sample probably + + + align:start position:0% +on a single crystalline sample probably +of 1 0-0 orientation so that these edges + + align:start position:0% +of 1 0-0 orientation so that these edges + + + align:start position:0% +of 1 0-0 orientation so that these edges +of the pyramids are 1 1 1 planes you + + align:start position:0% +of the pyramids are 1 1 1 planes you + + + align:start position:0% +of the pyramids are 1 1 1 planes you +could also achieve a similar although + + align:start position:0% +could also achieve a similar although + + + align:start position:0% +could also achieve a similar although +not identically looking result if you + + align:start position:0% +not identically looking result if you + + + align:start position:0% +not identically looking result if you +performed an acidic etch which would be + + align:start position:0% +performed an acidic etch which would be + + + align:start position:0% +performed an acidic etch which would be +an isotropic in nature so the light + + align:start position:0% +an isotropic in nature so the light + + + align:start position:0% +an isotropic in nature so the light +comes in for the textured surface some + + align:start position:0% +comes in for the textured surface some + + + align:start position:0% +comes in for the textured surface some +of it goes in to the device + + align:start position:0% +of it goes in to the device + + + align:start position:0% +of it goes in to the device +notice that Snell's laws in effect so + + align:start position:0% +notice that Snell's laws in effect so + + + align:start position:0% +notice that Snell's laws in effect so +the light bent or was refracted and some + + align:start position:0% +the light bent or was refracted and some + + + align:start position:0% +the light bent or was refracted and some +of the light is reflected off the + + align:start position:0% +of the light is reflected off the + + + align:start position:0% +of the light is reflected off the +surface now because of the texturization + + align:start position:0% +surface now because of the texturization + + + align:start position:0% +surface now because of the texturization +you get that second chance absorption so + + align:start position:0% +you get that second chance absorption so + + + align:start position:0% +you get that second chance absorption so +the light has to bounces before leaving + + align:start position:0% +the light has to bounces before leaving + + + align:start position:0% +the light has to bounces before leaving +which means that the probability of the + + align:start position:0% +which means that the probability of the + + + align:start position:0% +which means that the probability of the +light getting absorbed is 1 minus our + + align:start position:0% +light getting absorbed is 1 minus our + + + align:start position:0% +light getting absorbed is 1 minus our +quantity squared right and so you get an + + align:start position:0% +quantity squared right and so you get an + + + align:start position:0% +quantity squared right and so you get an +enhanced absorption and for those who + + align:start position:0% +enhanced absorption and for those who + + + align:start position:0% +enhanced absorption and for those who +looked at the samples before and after + + align:start position:0% +looked at the samples before and after + + + align:start position:0% +looked at the samples before and after +texturization you could visibly see that + + align:start position:0% +texturization you could visibly see that + + + align:start position:0% +texturization you could visibly see that +they looked darker the reflectivity had + + align:start position:0% +they looked darker the reflectivity had + + + align:start position:0% +they looked darker the reflectivity had +gone down I see some smiles over here + + align:start position:0% +gone down I see some smiles over here + + + align:start position:0% +gone down I see some smiles over here +there were probably some initial itching + + align:start position:0% +there were probably some initial itching + + + align:start position:0% +there were probably some initial itching +processes that didn't quite work out but + + align:start position:0% +processes that didn't quite work out but + + + align:start position:0% +processes that didn't quite work out but +eventually the process was controlled in + + align:start position:0% +eventually the process was controlled in + + + align:start position:0% +eventually the process was controlled in +and worked out fine so we have as well + + align:start position:0% +and worked out fine so we have as well + + + align:start position:0% +and worked out fine so we have as well +other mechanisms to trap the light + + align:start position:0% +other mechanisms to trap the light + + + align:start position:0% +other mechanisms to trap the light +besides just texturing our front surface + + align:start position:0% +besides just texturing our front surface + + + align:start position:0% +besides just texturing our front surface +these we didn't get to in to do an + + align:start position:0% +these we didn't get to in to do an + + + align:start position:0% +these we didn't get to in to do an +actual cell fab but we could envision + + align:start position:0% +actual cell fab but we could envision + + + align:start position:0% +actual cell fab but we could envision +putting a reflective or diffuse scatter + + align:start position:0% +putting a reflective or diffuse scatter + + + align:start position:0% +putting a reflective or diffuse scatter +on the back and a reflective layer so + + align:start position:0% +on the back and a reflective layer so + + + align:start position:0% +on the back and a reflective layer so +that the light that goes all the way + + align:start position:0% +that the light that goes all the way + + + align:start position:0% +that the light that goes all the way +through the material once gets bounced + + align:start position:0% +through the material once gets bounced + + + align:start position:0% +through the material once gets bounced +back in perhaps at an angle right to + + align:start position:0% +back in perhaps at an angle right to + + + align:start position:0% +back in perhaps at an angle right to +increase the light trapping in the back + + align:start position:0% +increase the light trapping in the back + + + align:start position:0% +increase the light trapping in the back +and that I think is represented on the + + align:start position:0% +and that I think is represented on the + + + align:start position:0% +and that I think is represented on the +previous slide it is indeed so we have a + + align:start position:0% +previous slide it is indeed so we have a + + + align:start position:0% +previous slide it is indeed so we have a +textured back surface and we also have + + align:start position:0% +textured back surface and we also have + + + align:start position:0% +textured back surface and we also have +this layer probably in this case it + + align:start position:0% +this layer probably in this case it + + + align:start position:0% +this layer probably in this case it +would most likely be a dielectric + + align:start position:0% +would most likely be a dielectric + + + align:start position:0% +would most likely be a dielectric +material + + align:start position:0% +material + + + align:start position:0% +material +with a refractive index that is + + align:start position:0% +with a refractive index that is + + + align:start position:0% +with a refractive index that is +significantly different than the + + align:start position:0% +significantly different than the + + + align:start position:0% +significantly different than the +absorber itself so if your absorber + + align:start position:0% +absorber itself so if your absorber + + + align:start position:0% +absorber itself so if your absorber +material is inorganic you might have a + + align:start position:0% +material is inorganic you might have a + + + align:start position:0% +material is inorganic you might have a +refractive index somewhere between 1.5 + + align:start position:0% +refractive index somewhere between 1.5 + + + align:start position:0% +refractive index somewhere between 1.5 +and 2 maybe on the high end and if you + + align:start position:0% +and 2 maybe on the high end and if you + + + align:start position:0% +and 2 maybe on the high end and if you +have an inorganic material you could + + align:start position:0% +have an inorganic material you could + + + align:start position:0% +have an inorganic material you could +have refractive indices as high as 3 3 + + align:start position:0% +have refractive indices as high as 3 3 + + + align:start position:0% +have refractive indices as high as 3 3 +and 1/2 and the material you put on the + + align:start position:0% +and 1/2 and the material you put on the + + + align:start position:0% +and 1/2 and the material you put on the +back would probably be as close as you + + align:start position:0% +back would probably be as close as you + + + align:start position:0% +back would probably be as close as you +could possibly get to air right to get a + + align:start position:0% +could possibly get to air right to get a + + + align:start position:0% +could possibly get to air right to get a +large reflection off the back as + + align:start position:0% +large reflection off the back as + + + align:start position:0% +large reflection off the back as +possible in the case of silicon devices + + align:start position:0% +possible in the case of silicon devices + + + align:start position:0% +possible in the case of silicon devices +oftentimes you have a dielectric + + align:start position:0% +oftentimes you have a dielectric + + + align:start position:0% +oftentimes you have a dielectric +material with a refractive index + + align:start position:0% +material with a refractive index + + + align:start position:0% +material with a refractive index +somewhere between 1.5 and 2 and that + + align:start position:0% +somewhere between 1.5 and 2 and that + + + align:start position:0% +somewhere between 1.5 and 2 and that +serves also to passivate the surface to + + align:start position:0% +serves also to passivate the surface to + + + align:start position:0% +serves also to passivate the surface to +prevent carriers from recombining on + + align:start position:0% +prevent carriers from recombining on + + + align:start position:0% +prevent carriers from recombining on +that back side so collection probability + + align:start position:0% +that back side so collection probability + + + align:start position:0% +that back side so collection probability +we talked about this earlier now that + + align:start position:0% +we talked about this earlier now that + + + align:start position:0% +we talked about this earlier now that +we've performed quantum efficiency and + + align:start position:0% +we've performed quantum efficiency and + + + align:start position:0% +we've performed quantum efficiency and +we've tested our own devices we want to + + align:start position:0% +we've tested our own devices we want to + + + align:start position:0% +we've tested our own devices we want to +walk through it again it's an important + + align:start position:0% +walk through it again it's an important + + + align:start position:0% +walk through it again it's an important +concept to really grasp I want to make + + align:start position:0% +concept to really grasp I want to make + + + align:start position:0% +concept to really grasp I want to make +sure that everybody got it we have here + + align:start position:0% +sure that everybody got it we have here + + + align:start position:0% +sure that everybody got it we have here +a PN Junction here's our p-type material + + align:start position:0% +a PN Junction here's our p-type material + + + align:start position:0% +a PN Junction here's our p-type material +here's our n-type material shown at the + + align:start position:0% +here's our n-type material shown at the + + + align:start position:0% +here's our n-type material shown at the +blue little dots those are our holes + + align:start position:0% +blue little dots those are our holes + + + align:start position:0% +blue little dots those are our holes +free holes mobile holes able to move + + align:start position:0% +free holes mobile holes able to move + + + align:start position:0% +free holes mobile holes able to move +around the material and then the n-type + + align:start position:0% +around the material and then the n-type + + + align:start position:0% +around the material and then the n-type +side we have here the red dots those are + + align:start position:0% +side we have here the red dots those are + + + align:start position:0% +side we have here the red dots those are +also free to move around the materials + + align:start position:0% +also free to move around the materials + + + align:start position:0% +also free to move around the materials +or electrons negative charge carriers + + align:start position:0% +or electrons negative charge carriers + + + align:start position:0% +or electrons negative charge carriers +omitted from this diagram omitted from + + align:start position:0% +omitted from this diagram omitted from + + + align:start position:0% +omitted from this diagram omitted from +this diagram is the fixed charge + + align:start position:0% +this diagram is the fixed charge + + + align:start position:0% +this diagram is the fixed charge +associated with each connectivity type + + align:start position:0% +associated with each connectivity type + + + align:start position:0% +associated with each connectivity type +we have for example fixed negative + + align:start position:0% +we have for example fixed negative + + + align:start position:0% +we have for example fixed negative +charge from the ionized acceptors from + + align:start position:0% +charge from the ionized acceptors from + + + align:start position:0% +charge from the ionized acceptors from +the p-type and fixed positive charge + + align:start position:0% +the p-type and fixed positive charge + + + align:start position:0% +the p-type and fixed positive charge +from the ionized donors in the n-type + + align:start position:0% +from the ionized donors in the n-type + + + align:start position:0% +from the ionized donors in the n-type +but we've emitted it for clarity we note + + align:start position:0% +but we've emitted it for clarity we note + + + align:start position:0% +but we've emitted it for clarity we note +that an electric field builds up here at + + align:start position:0% +that an electric field builds up here at + + + align:start position:0% +that an electric field builds up here at +the junction between and that sweeps + + align:start position:0% +the junction between and that sweeps + + + align:start position:0% +the junction between and that sweeps +carriers into one side or another so + + align:start position:0% +carriers into one side or another so + + + align:start position:0% +carriers into one side or another so +that if light comes in and generates a + + align:start position:0% +that if light comes in and generates a + + + align:start position:0% +that if light comes in and generates a +pair of charges due to charge neutrality + + align:start position:0% +pair of charges due to charge neutrality + + + align:start position:0% +pair of charges due to charge neutrality +it generates a pair positive in a + + align:start position:0% +it generates a pair positive in a + + + align:start position:0% +it generates a pair positive in a +negative the 1 1 charge carrier type + + align:start position:0% +negative the 1 1 charge carrier type + + + align:start position:0% +negative the 1 1 charge carrier type +will be swept across the junction and + + align:start position:0% +will be swept across the junction and + + + align:start position:0% +will be swept across the junction and +the other will remain inside of the + + align:start position:0% +the other will remain inside of the + + + align:start position:0% +the other will remain inside of the +material and so to be more precise about + + align:start position:0% +material and so to be more precise about + + + align:start position:0% +material and so to be more precise about +the exact motion that occurs with the + + align:start position:0% +the exact motion that occurs with the + + + align:start position:0% +the exact motion that occurs with the +carriers we have at first a diffusion + + align:start position:0% +carriers we have at first a diffusion + + + align:start position:0% +carriers we have at first a diffusion +process until the electric field starts + + align:start position:0% +process until the electric field starts + + + align:start position:0% +process until the electric field starts +becoming large and then finally drift + + align:start position:0% +becoming large and then finally drift + + + align:start position:0% +becoming large and then finally drift +across that Junction + + align:start position:0% +across that Junction + + + align:start position:0% +across that Junction +that's what generates the current inside + + align:start position:0% +that's what generates the current inside + + + align:start position:0% +that's what generates the current inside +of the solar cell device so collection + + align:start position:0% +of the solar cell device so collection + + + align:start position:0% +of the solar cell device so collection +probability means that light alike + + align:start position:0% +probability means that light alike + + + align:start position:0% +probability means that light alike +generated a photo generated minority + + align:start position:0% +generated a photo generated minority + + + align:start position:0% +generated a photo generated minority +carrier can readily recombine but if the + + align:start position:0% +carrier can readily recombine but if the + + + align:start position:0% +carrier can readily recombine but if the +carrier reaches the edge of this of the + + align:start position:0% +carrier reaches the edge of this of the + + + align:start position:0% +carrier reaches the edge of this of the +space charge region the minority carrier + + align:start position:0% +space charge region the minority carrier + + + align:start position:0% +space charge region the minority carrier +it can be swept across and collected so + + align:start position:0% +it can be swept across and collected so + + + align:start position:0% +it can be swept across and collected so +the probability of collection means for + + align:start position:0% +the probability of collection means for + + + align:start position:0% +the probability of collection means for +every electron hole pair that I generate + + align:start position:0% +every electron hole pair that I generate + + + align:start position:0% +every electron hole pair that I generate +at a certain depth what is a probability + + align:start position:0% +at a certain depth what is a probability + + + align:start position:0% +at a certain depth what is a probability +that the minority carrier will make it + + align:start position:0% +that the minority carrier will make it + + + align:start position:0% +that the minority carrier will make it +across a junction and this is what we're + + align:start position:0% +across a junction and this is what we're + + + align:start position:0% +across a junction and this is what we're +probing in spectral response yes + + align:start position:0% + + + + align:start position:0% + +okay so great question the exit on in + + align:start position:0% +okay so great question the exit on in + + + align:start position:0% +okay so great question the exit on in +silicon has a binding energy less than + + align:start position:0% +silicon has a binding energy less than + + + align:start position:0% +silicon has a binding energy less than +KT which means at room temperature the + + align:start position:0% +KT which means at room temperature the + + + align:start position:0% +KT which means at room temperature the +exit on readily dissociates so we so the + + align:start position:0% +exit on readily dissociates so we so the + + + align:start position:0% +exit on readily dissociates so we so the +exit on diffusion length can only be + + align:start position:0% +exit on diffusion length can only be + + + align:start position:0% +exit on diffusion length can only be +measured at lower temperatures the at + + align:start position:0% +measured at lower temperatures the at + + + align:start position:0% +measured at lower temperatures the at +room temperature you essentially just + + align:start position:0% +room temperature you essentially just + + + align:start position:0% +room temperature you essentially just +discussed minority carriers and the + + align:start position:0% +discussed minority carriers and the + + + align:start position:0% +discussed minority carriers and the +minority carrier diffusion length let's + + align:start position:0% +minority carrier diffusion length let's + + + align:start position:0% +minority carrier diffusion length let's +let's revert it in terms of lifetime and + + align:start position:0% +let's revert it in terms of lifetime and + + + align:start position:0% +let's revert it in terms of lifetime and +then do the translation to diffusion + + align:start position:0% +then do the translation to diffusion + + + align:start position:0% +then do the translation to diffusion +length in terms of lifetimes one + + align:start position:0% +length in terms of lifetimes one + + + align:start position:0% +length in terms of lifetimes one +typically has a range between a + + align:start position:0% +typically has a range between a + + + align:start position:0% +typically has a range between a +microsecond to a millisecond millisecond + + align:start position:0% +microsecond to a millisecond millisecond + + + align:start position:0% +microsecond to a millisecond millisecond +being in the high end it can go as high + + align:start position:0% +being in the high end it can go as high + + + align:start position:0% +being in the high end it can go as high +as five milliseconds even and so if you + + align:start position:0% +as five milliseconds even and so if you + + + align:start position:0% +as five milliseconds even and so if you +revert that into a diffusion length one + + align:start position:0% +revert that into a diffusion length one + + + align:start position:0% +revert that into a diffusion length one +microsecond lifetime would correspond to + + align:start position:0% +microsecond lifetime would correspond to + + + align:start position:0% +microsecond lifetime would correspond to +a 50 micron diffusion length and then + + align:start position:0% +a 50 micron diffusion length and then + + + align:start position:0% +a 50 micron diffusion length and then +you can do the rest of the conversion + + align:start position:0% +you can do the rest of the conversion + + + align:start position:0% +you can do the rest of the conversion +from there just taking the square root + + align:start position:0% +from there just taking the square root + + + align:start position:0% +from there just taking the square root +sign into account so it can be rather + + align:start position:0% +sign into account so it can be rather + + + align:start position:0% +sign into account so it can be rather +long on the order of the thickness of + + align:start position:0% +long on the order of the thickness of + + + align:start position:0% +long on the order of the thickness of +these solar cell devices now that's + + align:start position:0% +these solar cell devices now that's + + + align:start position:0% +these solar cell devices now that's +those length scales which we're talking + + align:start position:0% +those length scales which we're talking + + + align:start position:0% +those length scales which we're talking +about hundreds of microns maybe even a + + align:start position:0% +about hundreds of microns maybe even a + + + align:start position:0% +about hundreds of microns maybe even a +thousand microns compare that now to ten + + align:start position:0% +thousand microns compare that now to ten + + + align:start position:0% +thousand microns compare that now to ten +nanometer diffusion length say for an + + align:start position:0% +nanometer diffusion length say for an + + + align:start position:0% +nanometer diffusion length say for an +exit on in a polymer blend material then + + align:start position:0% +exit on in a polymer blend material then + + + align:start position:0% +exit on in a polymer blend material then +you have to reconsider your device + + align:start position:0% +you have to reconsider your device + + + align:start position:0% +you have to reconsider your device +architecture how you're going to + + align:start position:0% +architecture how you're going to + + + align:start position:0% +architecture how you're going to +actually collect them so this is a very + + align:start position:0% +actually collect them so this is a very + + + align:start position:0% +actually collect them so this is a very +generic picture which could easily be + + align:start position:0% +generic picture which could easily be + + + align:start position:0% +generic picture which could easily be +substituted instead of n type P type it + + align:start position:0% +substituted instead of n type P type it + + + align:start position:0% +substituted instead of n type P type it +can be easily substituted by say polymer + + align:start position:0% +can be easily substituted by say polymer + + + align:start position:0% +can be easily substituted by say polymer +1 and polymer 2 that just have the right + + align:start position:0% +1 and polymer 2 that just have the right + + + align:start position:0% +1 and polymer 2 that just have the right +band alignment two separate charge then + + align:start position:0% +band alignment two separate charge then + + + align:start position:0% +band alignment two separate charge then +it gets a little more complicated as + + align:start position:0% +it gets a little more complicated as + + + align:start position:0% +it gets a little more complicated as +well here we're assuming that the + + align:start position:0% +well here we're assuming that the + + + align:start position:0% +well here we're assuming that the +carriers that are swept across the + + align:start position:0% +carriers that are swept across the + + + align:start position:0% +carriers that are swept across the +junction can move easily away from the + + align:start position:0% +junction can move easily away from the + + + align:start position:0% +junction can move easily away from the +junction in a polymer not always so you + + align:start position:0% +junction in a polymer not always so you + + + align:start position:0% +junction in a polymer not always so you +might have charge accumulation right at + + align:start position:0% +might have charge accumulation right at + + + align:start position:0% +might have charge accumulation right at +the edge of the space charge region + + align:start position:0% +the edge of the space charge region + + + align:start position:0% +the edge of the space charge region +which creates his own field which + + align:start position:0% +which creates his own field which + + + align:start position:0% +which creates his own field which +counteracts the built-in field here and + + align:start position:0% +counteracts the built-in field here and + + + align:start position:0% +counteracts the built-in field here and +also inhibits current flow so things get + + align:start position:0% +also inhibits current flow so things get + + + align:start position:0% +also inhibits current flow so things get +a lot more complicated as you venture + + align:start position:0% +a lot more complicated as you venture + + + align:start position:0% +a lot more complicated as you venture +away from the simple case of say a well + + align:start position:0% +away from the simple case of say a well + + + align:start position:0% +away from the simple case of say a well +behaved + + align:start position:0% +behaved + + + align:start position:0% +behaved +what I call what is called in this case + + align:start position:0% +what I call what is called in this case + + + align:start position:0% +what I call what is called in this case +a homo Junction meaning a PN Junction + + align:start position:0% +a homo Junction meaning a PN Junction + + + align:start position:0% +a homo Junction meaning a PN Junction +created from the same material on both + + align:start position:0% +created from the same material on both + + + align:start position:0% +created from the same material on both +sides silicon just doped N and p-type if + + align:start position:0% +sides silicon just doped N and p-type if + + + align:start position:0% +sides silicon just doped N and p-type if +you have a hetero Junction comprised of + + align:start position:0% +you have a hetero Junction comprised of + + + align:start position:0% +you have a hetero Junction comprised of +two different materials you may have + + align:start position:0% +two different materials you may have + + + align:start position:0% +two different materials you may have +even I say additional effects occurring + + align:start position:0% +even I say additional effects occurring + + + align:start position:0% +even I say additional effects occurring +but it's always helpful to think about + + align:start position:0% +but it's always helpful to think about + + + align:start position:0% +but it's always helpful to think about +the motion of carriers from the + + align:start position:0% +the motion of carriers from the + + + align:start position:0% +the motion of carriers from the +perspective of drift and diffusion and + + align:start position:0% +perspective of drift and diffusion and + + + align:start position:0% +perspective of drift and diffusion and +if you're ever in doubt you can begin + + align:start position:0% +if you're ever in doubt you can begin + + + align:start position:0% +if you're ever in doubt you can begin +thinking about + + align:start position:0% +thinking about + + + align:start position:0% +thinking about +in terms of Delta T's small increments + + align:start position:0% +in terms of Delta T's small increments + + + align:start position:0% +in terms of Delta T's small increments +of time where you imagine light coming + + align:start position:0% +of time where you imagine light coming + + + align:start position:0% +of time where you imagine light coming +in generating an electron hole pair + + align:start position:0% +in generating an electron hole pair + + + align:start position:0% +in generating an electron hole pair +imagining what happens is that carrier + + align:start position:0% +imagining what happens is that carrier + + + align:start position:0% +imagining what happens is that carrier +moves across the general moves to the + + align:start position:0% +moves across the general moves to the + + + align:start position:0% +moves across the general moves to the +junction then moves across the junction + + align:start position:0% +junction then moves across the junction + + + align:start position:0% +junction then moves across the junction +and then what happens does it + + align:start position:0% +and then what happens does it + + + align:start position:0% +and then what happens does it +immediately get collected does it stay + + align:start position:0% +immediately get collected does it stay + + + align:start position:0% +immediately get collected does it stay +there what is the what what happens next + + align:start position:0% +there what is the what what happens next + + + align:start position:0% +there what is the what what happens next +is there a potential + + align:start position:0% +is there a potential + + + align:start position:0% +is there a potential +an attractive potential between the + + align:start position:0% +an attractive potential between the + + + align:start position:0% +an attractive potential between the +carriers on either side of that Junction + + align:start position:0% +carriers on either side of that Junction + + + align:start position:0% +carriers on either side of that Junction +so asking those sorts of questions can + + align:start position:0% +so asking those sorts of questions can + + + align:start position:0% +so asking those sorts of questions can +help you walk through and troubleshoot + + align:start position:0% +help you walk through and troubleshoot + + + align:start position:0% +help you walk through and troubleshoot +what exactly is going wrong with your + + align:start position:0% +what exactly is going wrong with your + + + align:start position:0% +what exactly is going wrong with your +device collection probability so we take + + align:start position:0% +device collection probability so we take + + + align:start position:0% +device collection probability so we take +this this diagram that we just saw on + + align:start position:0% +this this diagram that we just saw on + + + align:start position:0% +this this diagram that we just saw on +the previous slide this one right here + + align:start position:0% +the previous slide this one right here + + + align:start position:0% +the previous slide this one right here +and we say hmm if light were to come in + + align:start position:0% +and we say hmm if light were to come in + + + align:start position:0% +and we say hmm if light were to come in +and generate an electron hole pair right + + align:start position:0% +and generate an electron hole pair right + + + align:start position:0% +and generate an electron hole pair right +here then I would expect very high + + align:start position:0% +here then I would expect very high + + + align:start position:0% +here then I would expect very high +probability of collection meaning the + + align:start position:0% +probability of collection meaning the + + + align:start position:0% +probability of collection meaning the +one what the minority carrier be swept + + align:start position:0% +one what the minority carrier be swept + + + align:start position:0% +one what the minority carrier be swept +across the majority care would stay on + + align:start position:0% +across the majority care would stay on + + + align:start position:0% +across the majority care would stay on +this side and presuming that they can + + align:start position:0% +this side and presuming that they can + + + align:start position:0% +this side and presuming that they can +get from here to the contacts big + + align:start position:0% +get from here to the contacts big + + + align:start position:0% +get from here to the contacts big +assumption but assuming that they can + + align:start position:0% +assumption but assuming that they can + + + align:start position:0% +assumption but assuming that they can +then the probability of collection of + + align:start position:0% +then the probability of collection of + + + align:start position:0% +then the probability of collection of +those carriers will be very very high + + align:start position:0% +those carriers will be very very high + + + align:start position:0% +those carriers will be very very high +but if my light comes in deep within the + + align:start position:0% +but if my light comes in deep within the + + + align:start position:0% +but if my light comes in deep within the +device and generates an electron hole + + align:start position:0% +device and generates an electron hole + + + align:start position:0% +device and generates an electron hole +pair the minority carrier will have to + + align:start position:0% +pair the minority carrier will have to + + + align:start position:0% +pair the minority carrier will have to +cruise through it can think about it + + align:start position:0% +cruise through it can think about it + + + align:start position:0% +cruise through it can think about it +maybe a nice tasty chicken in the + + align:start position:0% +maybe a nice tasty chicken in the + + + align:start position:0% +maybe a nice tasty chicken in the +Everglades National Park trying to make + + align:start position:0% +Everglades National Park trying to make + + + align:start position:0% +Everglades National Park trying to make +its way over from that side all the way + + align:start position:0% +its way over from that side all the way + + + align:start position:0% +its way over from that side all the way +over to the junction in across the + + align:start position:0% +over to the junction in across the + + + align:start position:0% +over to the junction in across the +minority carriers at risk of recombining + + align:start position:0% +minority carriers at risk of recombining + + + align:start position:0% +minority carriers at risk of recombining +and many of them don't make it so we + + align:start position:0% +and many of them don't make it so we + + + align:start position:0% +and many of them don't make it so we +have the following graph the collection + + align:start position:0% +have the following graph the collection + + + align:start position:0% +have the following graph the collection +probability versus distance into the + + align:start position:0% +probability versus distance into the + + + align:start position:0% +probability versus distance into the +device where this yellow region + + align:start position:0% +device where this yellow region + + + align:start position:0% +device where this yellow region +represents the space charge region where + + align:start position:0% +represents the space charge region where + + + align:start position:0% +represents the space charge region where +the probability of collection is very + + align:start position:0% +the probability of collection is very + + + align:start position:0% +the probability of collection is very +high and as you move away from the space + + align:start position:0% +high and as you move away from the space + + + align:start position:0% +high and as you move away from the space +charge region the probability of + + align:start position:0% +charge region the probability of + + + align:start position:0% +charge region the probability of +collection decreases and you can see it + + align:start position:0% +collection decreases and you can see it + + + align:start position:0% +collection decreases and you can see it +decreases exponentially as a function of + + align:start position:0% +decreases exponentially as a function of + + + align:start position:0% +decreases exponentially as a function of +distance from the space charge region + + align:start position:0% +distance from the space charge region + + + align:start position:0% +distance from the space charge region +the reason you have almost not exactly + + align:start position:0% +the reason you have almost not exactly + + + align:start position:0% +the reason you have almost not exactly +symmetric these are two different decay + + align:start position:0% +symmetric these are two different decay + + + align:start position:0% +symmetric these are two different decay +constants but they're both exponential + + align:start position:0% +constants but they're both exponential + + + align:start position:0% +constants but they're both exponential +functions on either side is because over + + align:start position:0% +functions on either side is because over + + + align:start position:0% +functions on either side is because over +here on the what ostensibly would be the + + align:start position:0% +here on the what ostensibly would be the + + + align:start position:0% +here on the what ostensibly would be the +what did we call it the p-type side the + + align:start position:0% +what did we call it the p-type side the + + + align:start position:0% +what did we call it the p-type side the +electrons would be the minority carriers + + align:start position:0% +electrons would be the minority carriers + + + align:start position:0% +electrons would be the minority carriers +and over on the n-type side the holes of + + align:start position:0% +and over on the n-type side the holes of + + + align:start position:0% +and over on the n-type side the holes of +the minority carriers and each one is + + align:start position:0% +the minority carriers and each one is + + + align:start position:0% +the minority carriers and each one is +trying to get to the other side so the + + align:start position:0% +trying to get to the other side so the + + + align:start position:0% +trying to get to the other side so the +collection probability is actually the + + align:start position:0% +collection probability is actually the + + + align:start position:0% +collection probability is actually the +collection probability of minority + + align:start position:0% +collection probability of minority + + + align:start position:0% +collection probability of minority +carriers the precise definition of which + + align:start position:0% +carriers the precise definition of which + + + align:start position:0% +carriers the precise definition of which +is chain + + align:start position:0% +is chain + + + align:start position:0% +is chain +from one side of the junction to the + + align:start position:0% +from one side of the junction to the + + + align:start position:0% +from one side of the junction to the +other I on one side of the junction the + + align:start position:0% +other I on one side of the junction the + + + align:start position:0% +other I on one side of the junction the +electrons and minority carriers on the + + align:start position:0% +electrons and minority carriers on the + + + align:start position:0% +electrons and minority carriers on the +other side of the holes in the minority + + align:start position:0% +other side of the holes in the minority + + + align:start position:0% +other side of the holes in the minority +carriers all right so by probing at + + align:start position:0% +carriers all right so by probing at + + + align:start position:0% +carriers all right so by probing at +different wavelengths of light + + align:start position:0% +different wavelengths of light + + + align:start position:0% +different wavelengths of light +we essentially change the optical + + align:start position:0% +we essentially change the optical + + + align:start position:0% +we essentially change the optical +absorption coefficient of the material + + align:start position:0% +absorption coefficient of the material + + + align:start position:0% +absorption coefficient of the material +which means that the light will get + + align:start position:0% +which means that the light will get + + + align:start position:0% +which means that the light will get +absorbed at different depths so we might + + align:start position:0% +absorbed at different depths so we might + + + align:start position:0% +absorbed at different depths so we might +have a very short wavelength light that + + align:start position:0% +have a very short wavelength light that + + + align:start position:0% +have a very short wavelength light that +probes up here and then say light is + + align:start position:0% +probes up here and then say light is + + + align:start position:0% +probes up here and then say light is +coming in from this side right so short + + align:start position:0% +coming in from this side right so short + + + align:start position:0% +coming in from this side right so short +wavelength light is absorbed near the + + align:start position:0% +wavelength light is absorbed near the + + + align:start position:0% +wavelength light is absorbed near the +front surface and then longer longer + + align:start position:0% +front surface and then longer longer + + + align:start position:0% +front surface and then longer longer +longer and longer and longer and longer + + align:start position:0% +longer and longer and longer and longer + + + align:start position:0% +longer and longer and longer and longer +wavelengths until we're deep within the + + align:start position:0% +wavelengths until we're deep within the + + + align:start position:0% +wavelengths until we're deep within the +material and we can flesh out exactly + + align:start position:0% +material and we can flesh out exactly + + + align:start position:0% +material and we can flesh out exactly +what the current collection probability + + align:start position:0% +what the current collection probability + + + align:start position:0% +what the current collection probability +would be as a function of depth then we + + align:start position:0% +would be as a function of depth then we + + + align:start position:0% +would be as a function of depth then we +essentially take that data + + align:start position:0% +essentially take that data + + + align:start position:0% +essentially take that data +knowing the generation rate and the + + align:start position:0% +knowing the generation rate and the + + + align:start position:0% +knowing the generation rate and the +collection probability we can tease out + + align:start position:0% +collection probability we can tease out + + + align:start position:0% +collection probability we can tease out +the minority carrier diffusion length + + align:start position:0% +the minority carrier diffusion length + + + align:start position:0% +the minority carrier diffusion length +using the spectrophotometer so let me + + align:start position:0% +using the spectrophotometer so let me + + + align:start position:0% +using the spectrophotometer so let me +show you examples of good and bad cells + + align:start position:0% +show you examples of good and bad cells + + + align:start position:0% +show you examples of good and bad cells +this would be a bad solar cell and a + + align:start position:0% +this would be a bad solar cell and a + + + align:start position:0% +this would be a bad solar cell and a +good solar cell device right over here + + align:start position:0% +good solar cell device right over here + + + align:start position:0% +good solar cell device right over here +the good solar cell has a high internal + + align:start position:0% +the good solar cell has a high internal + + + align:start position:0% +the good solar cell has a high internal +quantum efficiency out to longer + + align:start position:0% +quantum efficiency out to longer + + + align:start position:0% +quantum efficiency out to longer +wavelengths and as we know from the very + + align:start position:0% +wavelengths and as we know from the very + + + align:start position:0% +wavelengths and as we know from the very +second lecture of our class the longer + + align:start position:0% +second lecture of our class the longer + + + align:start position:0% +second lecture of our class the longer +wavelengths get absorbed deeper into the + + align:start position:0% +wavelengths get absorbed deeper into the + + + align:start position:0% +wavelengths get absorbed deeper into the +device further from the junction and so + + align:start position:0% +device further from the junction and so + + + align:start position:0% +device further from the junction and so +you can see this tail off occurring + + align:start position:0% +you can see this tail off occurring + + + align:start position:0% +you can see this tail off occurring +actually the tail off somewhere in this + + align:start position:0% +actually the tail off somewhere in this + + + align:start position:0% +actually the tail off somewhere in this +region right here for this device is + + align:start position:0% +region right here for this device is + + + align:start position:0% +region right here for this device is +occurring within the bulk at some point + + align:start position:0% +occurring within the bulk at some point + + + align:start position:0% +occurring within the bulk at some point +the device just isn't thick enough to + + align:start position:0% +the device just isn't thick enough to + + + align:start position:0% +the device just isn't thick enough to +absorb all the light so there is an + + align:start position:0% +absorb all the light so there is an + + + align:start position:0% +absorb all the light so there is an +inevitable drop toward longer + + align:start position:0% +inevitable drop toward longer + + + align:start position:0% +inevitable drop toward longer +wavelengths but the bad cell doesn't + + align:start position:0% +wavelengths but the bad cell doesn't + + + align:start position:0% +wavelengths but the bad cell doesn't +even pour a job of collecting these + + align:start position:0% +even pour a job of collecting these + + + align:start position:0% +even pour a job of collecting these +longer wavelengths and thus in part + + align:start position:0% +longer wavelengths and thus in part + + + align:start position:0% +longer wavelengths and thus in part +because the minority carrier diffusion + + align:start position:0% +because the minority carrier diffusion + + + align:start position:0% +because the minority carrier diffusion +length of that particular cell was much + + align:start position:0% +length of that particular cell was much + + + align:start position:0% +length of that particular cell was much +lower or say the minority carrier + + align:start position:0% +lower or say the minority carrier + + + align:start position:0% +lower or say the minority carrier +diffusion length of the material which + + align:start position:0% +diffusion length of the material which + + + align:start position:0% +diffusion length of the material which +comprised the cell is much lower than + + align:start position:0% +comprised the cell is much lower than + + + align:start position:0% +comprised the cell is much lower than +the good cell so if you come in with a + + align:start position:0% +the good cell so if you come in with a + + + align:start position:0% +the good cell so if you come in with a +longer wavelength of light let's say oh + + align:start position:0% +longer wavelength of light let's say oh + + + align:start position:0% +longer wavelength of light let's say oh +maybe 933 nanometers in silicon that + + align:start position:0% +maybe 933 nanometers in silicon that + + + align:start position:0% +maybe 933 nanometers in silicon that +would give an absorption depth of around + + align:start position:0% +would give an absorption depth of around + + + align:start position:0% +would give an absorption depth of around +100 microns that's pretty far from the + + align:start position:0% +100 microns that's pretty far from the + + + align:start position:0% +100 microns that's pretty far from the +the junction now you you would have a + + align:start position:0% +the junction now you you would have a + + + align:start position:0% +the junction now you you would have a +much lower probability in the bad cell + + align:start position:0% +much lower probability in the bad cell + + + align:start position:0% +much lower probability in the bad cell +of collecting than the good cell and + + align:start position:0% +of collecting than the good cell and + + + align:start position:0% +of collecting than the good cell and +that's precisely because the diffusion + + align:start position:0% +that's precisely because the diffusion + + + align:start position:0% +that's precisely because the diffusion +length is lower + + align:start position:0% +length is lower + + + align:start position:0% +length is lower +so integrated over all of the + + align:start position:0% +so integrated over all of the + + + align:start position:0% +so integrated over all of the +wavelengths one obtains the + + align:start position:0% +wavelengths one obtains the + + + align:start position:0% +wavelengths one obtains the +short-circuit current and the method of + + align:start position:0% +short-circuit current and the method of + + + align:start position:0% +short-circuit current and the method of +measurement was the spectrophotometer + + align:start position:0% +measurement was the spectrophotometer + + + align:start position:0% +measurement was the spectrophotometer +now I understand most of you opted to + + align:start position:0% +now I understand most of you opted to + + + align:start position:0% +now I understand most of you opted to +choose Suns vo C for your one + + align:start position:0% +choose Suns vo C for your one + + + align:start position:0% +choose Suns vo C for your one +characterization tool to apply to + + align:start position:0% +characterization tool to apply to + + + align:start position:0% +characterization tool to apply to +yourself did anybody choose the + + align:start position:0% +yourself did anybody choose the + + + align:start position:0% +yourself did anybody choose the +spectrophotometer show of hands anybody + + align:start position:0% +spectrophotometer show of hands anybody + + + align:start position:0% +spectrophotometer show of hands anybody +it was broken yeah so the filter wheel + + align:start position:0% +it was broken yeah so the filter wheel + + + align:start position:0% +it was broken yeah so the filter wheel +was down okay that was that was it so + + align:start position:0% +was down okay that was that was it so + + + align:start position:0% +was down okay that was that was it so +let's see the filter wheel the filter + + align:start position:0% +let's see the filter wheel the filter + + + align:start position:0% +let's see the filter wheel the filter +wheel let's go fixing this here it is so + + align:start position:0% +wheel let's go fixing this here it is so + + + align:start position:0% +wheel let's go fixing this here it is so +the filter wheel was it was broken so + + align:start position:0% +the filter wheel was it was broken so + + + align:start position:0% +the filter wheel was it was broken so +essentially the the polychromatic light + + align:start position:0% +essentially the the polychromatic light + + + align:start position:0% +essentially the the polychromatic light +source was shining through a filter + + align:start position:0% +source was shining through a filter + + + align:start position:0% +source was shining through a filter +wheel which is selecting one wavelength + + align:start position:0% +wheel which is selecting one wavelength + + + align:start position:0% +wheel which is selecting one wavelength +of light the monochromator of course was + + align:start position:0% +of light the monochromator of course was + + + align:start position:0% +of light the monochromator of course was +helping as well and and eventually onto + + align:start position:0% +helping as well and and eventually onto + + + align:start position:0% +helping as well and and eventually onto +the solar cell sample which was shown in + + align:start position:0% +the solar cell sample which was shown in + + + align:start position:0% +the solar cell sample which was shown in +front of the light so that's the way in + + align:start position:0% +front of the light so that's the way in + + + align:start position:0% +front of the light so that's the way in +principle inspect response works and one + + align:start position:0% +principle inspect response works and one + + + align:start position:0% +principle inspect response works and one +variant of spectral response that's for + + align:start position:0% +variant of spectral response that's for + + + align:start position:0% +variant of spectral response that's for +the full device you typically have an + + align:start position:0% +the full device you typically have an + + + align:start position:0% +the full device you typically have an +illuminated area of a few millimeters + + align:start position:0% +illuminated area of a few millimeters + + + align:start position:0% +illuminated area of a few millimeters +squared or maybe even a few centimeters + + align:start position:0% +squared or maybe even a few centimeters + + + align:start position:0% +squared or maybe even a few centimeters +squared but let's say you that wasn't + + align:start position:0% +squared but let's say you that wasn't + + + align:start position:0% +squared but let's say you that wasn't +good enough for you you knew you had an + + align:start position:0% +good enough for you you knew you had an + + + align:start position:0% +good enough for you you knew you had an +in homogeneous material and you wanted + + align:start position:0% +in homogeneous material and you wanted + + + align:start position:0% +in homogeneous material and you wanted +to probe the in homogeneity across your + + align:start position:0% +to probe the in homogeneity across your + + + align:start position:0% +to probe the in homogeneity across your +device you got a large device maybe + + align:start position:0% +device you got a large device maybe + + + align:start position:0% +device you got a large device maybe +about that big a few a few tens of + + align:start position:0% +about that big a few a few tens of + + + align:start position:0% +about that big a few a few tens of +centimeters squared and you wanted to + + align:start position:0% +centimeters squared and you wanted to + + + align:start position:0% +centimeters squared and you wanted to +probe the distribution of minority + + align:start position:0% +probe the distribution of minority + + + align:start position:0% +probe the distribution of minority +carrier diffusion lengths across your + + align:start position:0% +carrier diffusion lengths across your + + + align:start position:0% +carrier diffusion lengths across your +device how would you do that well in one + + align:start position:0% +device how would you do that well in one + + + align:start position:0% +device how would you do that well in one +incarnation you would use a much more + + align:start position:0% +incarnation you would use a much more + + + align:start position:0% +incarnation you would use a much more +finely focused beam instead of having + + align:start position:0% +finely focused beam instead of having + + + align:start position:0% +finely focused beam instead of having +something in order of a millimeter you + + align:start position:0% +something in order of a millimeter you + + + align:start position:0% +something in order of a millimeter you +might shrink the beam spot size down to + + align:start position:0% +might shrink the beam spot size down to + + + align:start position:0% +might shrink the beam spot size down to +the range of single microns and then use + + align:start position:0% +the range of single microns and then use + + + align:start position:0% +the range of single microns and then use +an XY stepper motor to scan across your + + align:start position:0% +an XY stepper motor to scan across your + + + align:start position:0% +an XY stepper motor to scan across your +device and that's precisely what this + + align:start position:0% +device and that's precisely what this + + + align:start position:0% +device and that's precisely what this +does right here this white piece is the + + align:start position:0% +does right here this white piece is the + + + align:start position:0% +does right here this white piece is the +XY stage and this black head right here + + align:start position:0% +XY stage and this black head right here + + + align:start position:0% +XY stage and this black head right here +is essentially comprised of several + + align:start position:0% +is essentially comprised of several + + + align:start position:0% +is essentially comprised of several +lasers that will shine onto the sample + + align:start position:0% +lasers that will shine onto the sample + + + align:start position:0% +lasers that will shine onto the sample +now you need a few different wavelengths + + align:start position:0% +now you need a few different wavelengths + + + align:start position:0% +now you need a few different wavelengths +of light to really flesh out this curve + + align:start position:0% +of light to really flesh out this curve + + + align:start position:0% +of light to really flesh out this curve +to determine the minority carrier + + align:start position:0% +to determine the minority carrier + + + align:start position:0% +to determine the minority carrier +diffusion length from this curve and so + + align:start position:0% +diffusion length from this curve and so + + + align:start position:0% +diffusion length from this curve and so +the laser light is typically chosen at + + align:start position:0% +the laser light is typically chosen at + + + align:start position:0% +the laser light is typically chosen at +very auspicious wavelengths to maximize + + align:start position:0% +very auspicious wavelengths to maximize + + + align:start position:0% +very auspicious wavelengths to maximize +utility in this particular type of + + align:start position:0% +utility in this particular type of + + + align:start position:0% +utility in this particular type of +evaluation + + align:start position:0% +evaluation + + + align:start position:0% +evaluation +and so we have usually four you know + + align:start position:0% +and so we have usually four you know + + + align:start position:0% +and so we have usually four you know +minimum three you can always fit a line + + align:start position:0% +minimum three you can always fit a line + + + align:start position:0% +minimum three you can always fit a line +through two data points so minimum three + + align:start position:0% +through two data points so minimum three + + + align:start position:0% +through two data points so minimum three +laser wavelengths and usually about four + + align:start position:0% +laser wavelengths and usually about four + + + align:start position:0% +laser wavelengths and usually about four +or more to process the quantum + + align:start position:0% +or more to process the quantum + + + align:start position:0% +or more to process the quantum +efficiency as a function of position and + + align:start position:0% +efficiency as a function of position and + + + align:start position:0% +efficiency as a function of position and +so we the XY stage moves a sample around + + align:start position:0% +so we the XY stage moves a sample around + + + align:start position:0% +so we the XY stage moves a sample around +and the laser head is or moves the laser + + align:start position:0% +and the laser head is or moves the laser + + + align:start position:0% +and the laser head is or moves the laser +head around while the sample stays fixed + + align:start position:0% +head around while the sample stays fixed + + + align:start position:0% +head around while the sample stays fixed +and you map out the current response at + + align:start position:0% +and you map out the current response at + + + align:start position:0% +and you map out the current response at +each point on the device obtaining a map + + align:start position:0% +each point on the device obtaining a map + + + align:start position:0% +each point on the device obtaining a map +that looks much like this right here + + align:start position:0% +that looks much like this right here + + + align:start position:0% +that looks much like this right here +where this is on the y scale or the Z + + align:start position:0% +where this is on the y scale or the Z + + + align:start position:0% +where this is on the y scale or the Z +scale sorry you have from 0 to 120 + + align:start position:0% +scale sorry you have from 0 to 120 + + + align:start position:0% +scale sorry you have from 0 to 120 +micron diffusion length on that + + align:start position:0% +micron diffusion length on that + + + align:start position:0% +micron diffusion length on that +particular solar cell device and points + + align:start position:0% +particular solar cell device and points + + + align:start position:0% +particular solar cell device and points +3-1 and to represent regions in which + + align:start position:0% +3-1 and to represent regions in which + + + align:start position:0% +3-1 and to represent regions in which +the minority carrier diffusion length + + align:start position:0% +the minority carrier diffusion length + + + align:start position:0% +the minority carrier diffusion length +was calculated using the method that we + + align:start position:0% +was calculated using the method that we + + + align:start position:0% +was calculated using the method that we +have discussed in the previous lectures + + align:start position:0% +have discussed in the previous lectures + + + align:start position:0% +have discussed in the previous lectures +the bazoer Paul bezoar method so we have + + align:start position:0% +the bazoer Paul bezoar method so we have + + + align:start position:0% +the bazoer Paul bezoar method so we have +a map of minority carrier diffusion + + align:start position:0% +a map of minority carrier diffusion + + + align:start position:0% +a map of minority carrier diffusion +length across our device some regions + + align:start position:0% +length across our device some regions + + + align:start position:0% +length across our device some regions +underperforming other regions performing + + align:start position:0% +underperforming other regions performing + + + align:start position:0% +underperforming other regions performing +rather well and we can see that in + + align:start position:0% +rather well and we can see that in + + + align:start position:0% +rather well and we can see that in +general these lower cost materials tend + + align:start position:0% +general these lower cost materials tend + + + align:start position:0% +general these lower cost materials tend +to be fairly in homogeneous in terms of + + align:start position:0% +to be fairly in homogeneous in terms of + + + align:start position:0% +to be fairly in homogeneous in terms of +their performance response right and if + + align:start position:0% +their performance response right and if + + + align:start position:0% +their performance response right and if +you really want to get fancy and say my + + align:start position:0% +you really want to get fancy and say my + + + align:start position:0% +you really want to get fancy and say my +goodness if I spend all this time + + align:start position:0% +goodness if I spend all this time + + + align:start position:0% +goodness if I spend all this time +mapping my device I'm not going to get + + align:start position:0% +mapping my device I'm not going to get + + + align:start position:0% +mapping my device I'm not going to get +through many devices during my PhD I'm + + align:start position:0% +through many devices during my PhD I'm + + + align:start position:0% +through many devices during my PhD I'm +going to have to make do with very poor + + align:start position:0% +going to have to make do with very poor + + + align:start position:0% +going to have to make do with very poor +statistics how do i speed this up some + + align:start position:0% +statistics how do i speed this up some + + + align:start position:0% +statistics how do i speed this up some +very clever people have figured out that + + align:start position:0% +very clever people have figured out that + + + align:start position:0% +very clever people have figured out that +if you fire your laser diode + + align:start position:0% +if you fire your laser diode + + + align:start position:0% +if you fire your laser diode +simultaneously but with different + + align:start position:0% +simultaneously but with different + + + align:start position:0% +simultaneously but with different +frequencies each of them with its own + + align:start position:0% +frequencies each of them with its own + + + align:start position:0% +frequencies each of them with its own +frequency you can D convolute the + + align:start position:0% +frequency you can D convolute the + + + align:start position:0% +frequency you can D convolute the +current response of your device using a + + align:start position:0% +current response of your device using a + + + align:start position:0% +current response of your device using a +Fourier transform to pick out the + + align:start position:0% +Fourier transform to pick out the + + + align:start position:0% +Fourier transform to pick out the +current response at each portion of the + + align:start position:0% +current response at each portion of the + + + align:start position:0% +current response at each portion of the +frequency space and in other words + + align:start position:0% +frequency space and in other words + + + align:start position:0% +frequency space and in other words +decouple the different wavelengths of + + align:start position:0% +decouple the different wavelengths of + + + align:start position:0% +decouple the different wavelengths of +light so it's a little clever method + + align:start position:0% +light so it's a little clever method + + + align:start position:0% +light so it's a little clever method +involving Fourier transforms and lock-in + + align:start position:0% +involving Fourier transforms and lock-in + + + align:start position:0% +involving Fourier transforms and lock-in +method to speed up the measurement a + + align:start position:0% +method to speed up the measurement a + + + align:start position:0% +method to speed up the measurement a +little bit small aside small footnote + + align:start position:0% +little bit small aside small footnote + + + align:start position:0% +little bit small aside small footnote +there okay important minority carrier + + align:start position:0% +there okay important minority carrier + + + align:start position:0% +there okay important minority carrier +diffusion length that's that's a most + + align:start position:0% +diffusion length that's that's a most + + + align:start position:0% +diffusion length that's that's a most +important so we can relate the diffusion + + align:start position:0% +important so we can relate the diffusion + + + align:start position:0% +important so we can relate the diffusion +length directly back to our IV curve via + + align:start position:0% +length directly back to our IV curve via + + + align:start position:0% +length directly back to our IV curve via +the saturation current by the J naught I + + align:start position:0% +the saturation current by the J naught I + + + align:start position:0% +the saturation current by the J naught I +naught depending on whether you're + + align:start position:0% +naught depending on whether you're + + + align:start position:0% +naught depending on whether you're +looking at density or + + align:start position:0% +looking at density or + + + align:start position:0% +looking at density or +Sulaiman let's shift gears a bit I want + + align:start position:0% +Sulaiman let's shift gears a bit I want + + + align:start position:0% +Sulaiman let's shift gears a bit I want +to talk about the vo C measurements and + + align:start position:0% +to talk about the vo C measurements and + + + align:start position:0% +to talk about the vo C measurements and +fill factor loss measurements so how do + + align:start position:0% +fill factor loss measurements so how do + + + align:start position:0% +fill factor loss measurements so how do +you determine losses in vo C and fill + + align:start position:0% +you determine losses in vo C and fill + + + align:start position:0% +you determine losses in vo C and fill +factor before I jump into this does + + align:start position:0% +factor before I jump into this does + + + align:start position:0% +factor before I jump into this does +anybody have any questions about DSC + + align:start position:0% +anybody have any questions about DSC + + + align:start position:0% +anybody have any questions about DSC +loss mechanisms so sad that the + + align:start position:0% +loss mechanisms so sad that the + + + align:start position:0% +loss mechanisms so sad that the +spectrophotometer wasn't up and running + + align:start position:0% +spectrophotometer wasn't up and running + + + align:start position:0% +spectrophotometer wasn't up and running +sniff that's a it should be fixed + + align:start position:0% +sniff that's a it should be fixed + + + align:start position:0% +sniff that's a it should be fixed +relatively soon right Joe it's fixed now + + align:start position:0% +relatively soon right Joe it's fixed now + + + align:start position:0% +relatively soon right Joe it's fixed now +all right so we have I think David Barry + + align:start position:0% +all right so we have I think David Barry + + + align:start position:0% +all right so we have I think David Barry +Needleman is back on board right hey + + align:start position:0% +Needleman is back on board right hey + + + align:start position:0% +Needleman is back on board right hey +over the route back as well yeah so if + + align:start position:0% +over the route back as well yeah so if + + + align:start position:0% +over the route back as well yeah so if +we have folks who still want to measure + + align:start position:0% +we have folks who still want to measure + + + align:start position:0% +we have folks who still want to measure +their devices using spectrophotometer + + align:start position:0% +their devices using spectrophotometer + + + align:start position:0% +their devices using spectrophotometer +measurement we can probably make + + align:start position:0% +measurement we can probably make + + + align:start position:0% +measurement we can probably make +arrangements for say what 10 10 cells to + + align:start position:0% +arrangements for say what 10 10 cells to + + + align:start position:0% +arrangements for say what 10 10 cells to +be measured something that means okay + + align:start position:0% + + + + align:start position:0% + +okay yeah let's let's let's fitmin the + + align:start position:0% +okay yeah let's let's let's fitmin the + + + align:start position:0% +okay yeah let's let's let's fitmin the +three people who wanted to do them and + + align:start position:0% +three people who wanted to do them and + + + align:start position:0% +three people who wanted to do them and +we'll have our full data set good so + + align:start position:0% +we'll have our full data set good so + + + align:start position:0% +we'll have our full data set good so +let's describe fill factor in vo C + + align:start position:0% +let's describe fill factor in vo C + + + align:start position:0% +let's describe fill factor in vo C +losses and this is essentially generate + + align:start position:0% +losses and this is essentially generate + + + align:start position:0% +losses and this is essentially generate +venturing into operating conditions + + align:start position:0% +venturing into operating conditions + + + align:start position:0% +venturing into operating conditions +under short circuit conditions how much + + align:start position:0% +under short circuit conditions how much + + + align:start position:0% +under short circuit conditions how much +power is running through the solar cell + + align:start position:0% +power is running through the solar cell + + + align:start position:0% +power is running through the solar cell +device power defined as current voltage + + align:start position:0% +device power defined as current voltage + + + align:start position:0% +device power defined as current voltage +product zero why is that no voltage + + align:start position:0% +product zero why is that no voltage + + + align:start position:0% +product zero why is that no voltage +right so you're not testing your solar + + align:start position:0% +right so you're not testing your solar + + + align:start position:0% +right so you're not testing your solar +cell under ideal operating conditions + + align:start position:0% +cell under ideal operating conditions + + + align:start position:0% +cell under ideal operating conditions +it's a sense an artificial operating + + align:start position:0% +it's a sense an artificial operating + + + align:start position:0% +it's a sense an artificial operating +condition simply to probe a bulk + + align:start position:0% +condition simply to probe a bulk + + + align:start position:0% +condition simply to probe a bulk +property characteristics right to + + align:start position:0% +property characteristics right to + + + align:start position:0% +property characteristics right to +minimize the effect of the junction now + + align:start position:0% +minimize the effect of the junction now + + + align:start position:0% +minimize the effect of the junction now +if you really want to see how is the + + align:start position:0% +if you really want to see how is the + + + align:start position:0% +if you really want to see how is the +junction behaving how is that charge + + align:start position:0% +junction behaving how is that charge + + + align:start position:0% +junction behaving how is that charge +separation going you might want to + + align:start position:0% +separation going you might want to + + + align:start position:0% +separation going you might want to +venture into forward bias conditions and + + align:start position:0% +venture into forward bias conditions and + + + align:start position:0% +venture into forward bias conditions and +eventually into open circuit voltage + + align:start position:0% +eventually into open circuit voltage + + + align:start position:0% +eventually into open circuit voltage +conditions to really test what the + + align:start position:0% +conditions to really test what the + + + align:start position:0% +conditions to really test what the +junction quality is instead of just + + align:start position:0% +junction quality is instead of just + + + align:start position:0% +junction quality is instead of just +probing bulk properties so let's talk + + align:start position:0% +probing bulk properties so let's talk + + + align:start position:0% +probing bulk properties so let's talk +about some of the measurement techniques + + align:start position:0% +about some of the measurement techniques + + + align:start position:0% +about some of the measurement techniques +to really get the heart of how a solar + + align:start position:0% +to really get the heart of how a solar + + + align:start position:0% +to really get the heart of how a solar +cell is performing it's helpful to do + + align:start position:0% +cell is performing it's helpful to do + + + align:start position:0% +cell is performing it's helpful to do +the JSC measurements helps you predict + + align:start position:0% +the JSC measurements helps you predict + + + align:start position:0% +the JSC measurements helps you predict +what might be some of the lost + + align:start position:0% +what might be some of the lost + + + align:start position:0% +what might be some of the lost +mechanisms later on but but this really + + align:start position:0% +mechanisms later on but but this really + + + align:start position:0% +mechanisms later on but but this really +gets at the meat of it IV curve + + align:start position:0% +gets at the meat of it IV curve + + + align:start position:0% +gets at the meat of it IV curve +measurements check we we study that we + + align:start position:0% +measurements check we we study that we + + + align:start position:0% +measurements check we we study that we +did that in the laboratory and I think + + align:start position:0% +did that in the laboratory and I think + + + align:start position:0% +did that in the laboratory and I think +we have a pretty good sense of what's + + align:start position:0% +we have a pretty good sense of what's + + + align:start position:0% +we have a pretty good sense of what's +going on there now series resistance + + align:start position:0% +going on there now series resistance + + + align:start position:0% +going on there now series resistance +losses we talked earlier in the class + + align:start position:0% +losses we talked earlier in the class + + + align:start position:0% +losses we talked earlier in the class +about contact and sheet resistance + + align:start position:0% +about contact and sheet resistance + + + align:start position:0% +about contact and sheet resistance +losses now we'll go back to it again + + align:start position:0% +losses now we'll go back to it again + + + align:start position:0% +losses now we'll go back to it again +just to revisit so we have the materials + + align:start position:0% +just to revisit so we have the materials + + + align:start position:0% +just to revisit so we have the materials +necessary to write up the report here on + + align:start position:0% +necessary to write up the report here on + + + align:start position:0% +necessary to write up the report here on +this project shunt resistance + + align:start position:0% +this project shunt resistance + + + align:start position:0% +this project shunt resistance +specifically in shunt resistance will + + align:start position:0% +specifically in shunt resistance will + + + align:start position:0% +specifically in shunt resistance will +talk about lock-in thermography and + + align:start position:0% +talk about lock-in thermography and + + + align:start position:0% +talk about lock-in thermography and +electroluminescence and finally we'll + + align:start position:0% +electroluminescence and finally we'll + + + align:start position:0% +electroluminescence and finally we'll +have a small slide on Sun's vo C and + + align:start position:0% +have a small slide on Sun's vo C and + + + align:start position:0% +have a small slide on Sun's vo C and +talk about that as well since I know the + + align:start position:0% +talk about that as well since I know the + + + align:start position:0% +talk about that as well since I know the +majority of you selected that as your + + align:start position:0% +majority of you selected that as your + + + align:start position:0% +majority of you selected that as your +measurement tool all right + + align:start position:0% +measurement tool all right + + + align:start position:0% +measurement tool all right +so open circuit voltage so reading + + align:start position:0% +so open circuit voltage so reading + + + align:start position:0% +so open circuit voltage so reading +straight off of the slide here if the + + align:start position:0% +straight off of the slide here if the + + + align:start position:0% +straight off of the slide here if the +collected light generated carriers are + + align:start position:0% +collected light generated carriers are + + + align:start position:0% +collected light generated carriers are +not extracted in the solar cell but + + align:start position:0% +not extracted in the solar cell but + + + align:start position:0% +not extracted in the solar cell but +instead remain that then a charge + + align:start position:0% +instead remain that then a charge + + + align:start position:0% +instead remain that then a charge +separation exists across meaning there's + + align:start position:0% +separation exists across meaning there's + + + align:start position:0% +separation exists across meaning there's +a buildup of charge + + align:start position:0% +a buildup of charge + + + align:start position:0% +a buildup of charge +and the charge separation reduces the + + align:start position:0% +and the charge separation reduces the + + + align:start position:0% +and the charge separation reduces the +electric field in the depletion region + + align:start position:0% +electric field in the depletion region + + + align:start position:0% +electric field in the depletion region +which reduces the barrier to diffusion + + align:start position:0% +which reduces the barrier to diffusion + + + align:start position:0% +which reduces the barrier to diffusion +current and causes the diffusion current + + align:start position:0% +current and causes the diffusion current + + + align:start position:0% +current and causes the diffusion current +to flow in other words if you have light + + align:start position:0% +to flow in other words if you have light + + + align:start position:0% +to flow in other words if you have light +coming into your device but you're not + + align:start position:0% +coming into your device but you're not + + + align:start position:0% +coming into your device but you're not +able to extract the charges from either + + align:start position:0% +able to extract the charges from either + + + align:start position:0% +able to extract the charges from either +side to make sure that the chemical + + align:start position:0% +side to make sure that the chemical + + + align:start position:0% +side to make sure that the chemical +potential is equal on both sides the + + align:start position:0% +potential is equal on both sides the + + + align:start position:0% +potential is equal on both sides the +chemical potential will change on either + + align:start position:0% +chemical potential will change on either + + + align:start position:0% +chemical potential will change on either +side you'll have a buildup of one charge + + align:start position:0% +side you'll have a buildup of one charge + + + align:start position:0% +side you'll have a buildup of one charge +type on one side of the junction and + + align:start position:0% +type on one side of the junction and + + + align:start position:0% +type on one side of the junction and +buildup of the opposite charge type on + + align:start position:0% +buildup of the opposite charge type on + + + align:start position:0% +buildup of the opposite charge type on +the other side of the junction so that + + align:start position:0% +the other side of the junction so that + + + align:start position:0% +the other side of the junction so that +will shift the the quasi shift the the + + align:start position:0% +will shift the the quasi shift the the + + + align:start position:0% +will shift the the quasi shift the the +Fermi energy on either side of the + + align:start position:0% +Fermi energy on either side of the + + + align:start position:0% +Fermi energy on either side of the +junction result in a bias of your device + + align:start position:0% +junction result in a bias of your device + + + align:start position:0% +junction result in a bias of your device +and eventually counteract the built-in + + align:start position:0% +and eventually counteract the built-in + + + align:start position:0% +and eventually counteract the built-in +electric field to the point where the + + align:start position:0% +electric field to the point where the + + + align:start position:0% +electric field to the point where the +diffusion current is now enabled to flow + + align:start position:0% +diffusion current is now enabled to flow + + + align:start position:0% +diffusion current is now enabled to flow +all the sound familiar to folks might be + + align:start position:0% +all the sound familiar to folks might be + + + align:start position:0% +all the sound familiar to folks might be +a little rusty but it's all there + + align:start position:0% +a little rusty but it's all there + + + align:start position:0% +a little rusty but it's all there +so the idea now is to begin probing that + + align:start position:0% +so the idea now is to begin probing that + + + align:start position:0% +so the idea now is to begin probing that +that Junction condition we talked about + + align:start position:0% +that Junction condition we talked about + + + align:start position:0% +that Junction condition we talked about +the ideal diode equation and now we're + + align:start position:0% +the ideal diode equation and now we're + + + align:start position:0% +the ideal diode equation and now we're +going to piece through it once again + + align:start position:0% +going to piece through it once again + + + align:start position:0% +going to piece through it once again +this is your current density here and I + + align:start position:0% +this is your current density here and I + + + align:start position:0% +this is your current density here and I +believe if you really want to be precise + + align:start position:0% +believe if you really want to be precise + + + align:start position:0% +believe if you really want to be precise +about this you should use straight + + align:start position:0% +about this you should use straight + + + align:start position:0% +about this you should use straight +current and not current density reason + + align:start position:0% +current and not current density reason + + + align:start position:0% +current and not current density reason +being if you look at current resistance + + align:start position:0% +being if you look at current resistance + + + align:start position:0% +being if you look at current resistance +product that gives you voltage but + + align:start position:0% +product that gives you voltage but + + + align:start position:0% +product that gives you voltage but +current density resistance product gives + + align:start position:0% +current density resistance product gives + + + align:start position:0% +current density resistance product gives +you essentially a voltage density which + + align:start position:0% +you essentially a voltage density which + + + align:start position:0% +you essentially a voltage density which +is not a unit that we typically use so + + align:start position:0% +is not a unit that we typically use so + + + align:start position:0% +is not a unit that we typically use so +just keep that in mind as small little + + align:start position:0% +just keep that in mind as small little + + + align:start position:0% +just keep that in mind as small little +asterisks this equation is often used in + + align:start position:0% +asterisks this equation is often used in + + + align:start position:0% +asterisks this equation is often used in +PV that little unit conversion issues + + align:start position:0% +PV that little unit conversion issues + + + align:start position:0% +PV that little unit conversion issues +generally ignored but but you might want + + align:start position:0% +generally ignored but but you might want + + + align:start position:0% +generally ignored but but you might want +to flag it for your own benefit so we + + align:start position:0% +to flag it for your own benefit so we + + + align:start position:0% +to flag it for your own benefit so we +have the current output of our device as + + align:start position:0% +have the current output of our device as + + + align:start position:0% +have the current output of our device as +a function of voltage and this is a + + align:start position:0% +a function of voltage and this is a + + + align:start position:0% +a function of voltage and this is a +rather complicated expression going well + + align:start position:0% +rather complicated expression going well + + + align:start position:0% +rather complicated expression going well +beyond the ideal diode equation the + + align:start position:0% +beyond the ideal diode equation the + + + align:start position:0% +beyond the ideal diode equation the +ideal diode equation which would consist + + align:start position:0% +ideal diode equation which would consist + + + align:start position:0% +ideal diode equation which would consist +of the J sub L the illumination current + + align:start position:0% +of the J sub L the illumination current + + + align:start position:0% +of the J sub L the illumination current +this is the light coming in creating the + + align:start position:0% +this is the light coming in creating the + + + align:start position:0% +this is the light coming in creating the +carriers that are then swept across the + + align:start position:0% +carriers that are then swept across the + + + align:start position:0% +carriers that are then swept across the +junction the J sub L is going to be the + + align:start position:0% +junction the J sub L is going to be the + + + align:start position:0% +junction the J sub L is going to be the +integral current under a spectral + + align:start position:0% +integral current under a spectral + + + align:start position:0% +integral current under a spectral +response curve right at each wavelength + + align:start position:0% +response curve right at each wavelength + + + align:start position:0% +response curve right at each wavelength +waited for the wavelength of the + + align:start position:0% +waited for the wavelength of the + + + align:start position:0% +waited for the wavelength of the +incoming light are the intensity at that + + align:start position:0% +incoming light are the intensity at that + + + align:start position:0% +incoming light are the intensity at that +particular bandwidth of the incoming + + align:start position:0% +particular bandwidth of the incoming + + + align:start position:0% +particular bandwidth of the incoming +light think of it this way + + align:start position:0% +light think of it this way + + + align:start position:0% +light think of it this way +you're measuring the spectral response + + align:start position:0% +you're measuring the spectral response + + + align:start position:0% +you're measuring the spectral response +at each particular wavelength what the + + align:start position:0% +at each particular wavelength what the + + + align:start position:0% +at each particular wavelength what the +collection probability is then if you + + align:start position:0% +collection probability is then if you + + + align:start position:0% +collection probability is then if you +multiplied by the total number photons + + align:start position:0% +multiplied by the total number photons + + + align:start position:0% +multiplied by the total number photons +in that wavelength range you're + + align:start position:0% +in that wavelength range you're + + + align:start position:0% +in that wavelength range you're +determining the total number of carriers + + align:start position:0% +determining the total number of carriers + + + align:start position:0% +determining the total number of carriers +generated within that frequency range of + + align:start position:0% +generated within that frequency range of + + + align:start position:0% +generated within that frequency range of +light and if you add up all of the + + align:start position:0% +light and if you add up all of the + + + align:start position:0% +light and if you add up all of the +little bins you get all of the carriers + + align:start position:0% +little bins you get all of the carriers + + + align:start position:0% +little bins you get all of the carriers +generated by all of the light right and + + align:start position:0% +generated by all of the light right and + + + align:start position:0% +generated by all of the light right and +you can adjust depending what spectral + + align:start position:0% +you can adjust depending what spectral + + + align:start position:0% +you can adjust depending what spectral +conditions you have say a 1.5 spectrum + + align:start position:0% +conditions you have say a 1.5 spectrum + + + align:start position:0% +conditions you have say a 1.5 spectrum +so the J sub L here this one is our + + align:start position:0% +so the J sub L here this one is our + + + align:start position:0% +so the J sub L here this one is our +short circuit current effectively and + + align:start position:0% +short circuit current effectively and + + + align:start position:0% +short circuit current effectively and +what is derived from a spectral response + + align:start position:0% +what is derived from a spectral response + + + align:start position:0% +what is derived from a spectral response +measurement the rest of these terms here + + align:start position:0% +measurement the rest of these terms here + + + align:start position:0% +measurement the rest of these terms here +are are of interest so that J let's + + align:start position:0% +are are of interest so that J let's + + + align:start position:0% +are are of interest so that J let's +break it on two pieces here this term + + align:start position:0% +break it on two pieces here this term + + + align:start position:0% +break it on two pieces here this term +over here is essentially to take into + + align:start position:0% +over here is essentially to take into + + + align:start position:0% +over here is essentially to take into +account shunt resistance losses if we + + align:start position:0% +account shunt resistance losses if we + + + align:start position:0% +account shunt resistance losses if we +have shunts in our device we're going to + + align:start position:0% +have shunts in our device we're going to + + + align:start position:0% +have shunts in our device we're going to +be reducing the total power output these + + align:start position:0% +be reducing the total power output these + + + align:start position:0% +be reducing the total power output these +two components what are usually called + + align:start position:0% +two components what are usually called + + + align:start position:0% +two components what are usually called +diffusion current and recombination + + align:start position:0% +diffusion current and recombination + + + align:start position:0% +diffusion current and recombination +current this one you have to take me for + + align:start position:0% +current this one you have to take me for + + + align:start position:0% +current this one you have to take me for +my word at it right now this is the + + align:start position:0% +my word at it right now this is the + + + align:start position:0% +my word at it right now this is the +recombination within the space charge + + align:start position:0% +recombination within the space charge + + + align:start position:0% +recombination within the space charge +region and this over here is a + + align:start position:0% +region and this over here is a + + + align:start position:0% +region and this over here is a +recombination within the bulk of the + + align:start position:0% +recombination within the bulk of the + + + align:start position:0% +recombination within the bulk of the +solar cell here's a good way to think + + align:start position:0% +solar cell here's a good way to think + + + align:start position:0% +solar cell here's a good way to think +about it if our solar cell is not + + align:start position:0% +about it if our solar cell is not + + + align:start position:0% +about it if our solar cell is not +forward biased if it's very very + + align:start position:0% +forward biased if it's very very + + + align:start position:0% +forward biased if it's very very +slightly forward by it's just a little + + align:start position:0% +slightly forward by it's just a little + + + align:start position:0% +slightly forward by it's just a little +bit there's going to be a large barrier + + align:start position:0% +bit there's going to be a large barrier + + + align:start position:0% +bit there's going to be a large barrier +for care effort for majority carriers on + + align:start position:0% +for care effort for majority carriers on + + + align:start position:0% +for care effort for majority carriers on +one side of the junction to overcome to + + align:start position:0% +one side of the junction to overcome to + + + align:start position:0% +one side of the junction to overcome to +drive a drift current right side + + align:start position:0% +drive a drift current right side + + + align:start position:0% +drive a drift current right side +diffusion current very large barrier to + + align:start position:0% +diffusion current very large barrier to + + + align:start position:0% +diffusion current very large barrier to +overcome and hence the recombination is + + align:start position:0% +overcome and hence the recombination is + + + align:start position:0% +overcome and hence the recombination is +most likely to occur within the space + + align:start position:0% +most likely to occur within the space + + + align:start position:0% +most likely to occur within the space +charge region the carriers aren't likely + + align:start position:0% +charge region the carriers aren't likely + + + align:start position:0% +charge region the carriers aren't likely +to overcome that barrier get into the + + align:start position:0% +to overcome that barrier get into the + + + align:start position:0% +to overcome that barrier get into the +bulk and recombine there whereas if + + align:start position:0% +bulk and recombine there whereas if + + + align:start position:0% +bulk and recombine there whereas if +we're under large forward bias + + align:start position:0% +we're under large forward bias + + + align:start position:0% +we're under large forward bias +conditions now the carrier's can very + + align:start position:0% +conditions now the carrier's can very + + + align:start position:0% +conditions now the carrier's can very +easily go over that barrier and + + align:start position:0% +easily go over that barrier and + + + align:start position:0% +easily go over that barrier and +recombine in the bulk so this term right + + align:start position:0% +recombine in the bulk so this term right + + + align:start position:0% +recombine in the bulk so this term right +here dominates under low forward bias + + align:start position:0% +here dominates under low forward bias + + + align:start position:0% +here dominates under low forward bias +conditions and this term over here + + align:start position:0% +conditions and this term over here + + + align:start position:0% +conditions and this term over here +dominates under larger forward bias + + align:start position:0% +dominates under larger forward bias + + + align:start position:0% +dominates under larger forward bias +conditions and that's why you see when + + align:start position:0% +conditions and that's why you see when + + + align:start position:0% +conditions and that's why you see when +you plot your IV curve on log linear + + align:start position:0% +you plot your IV curve on log linear + + + align:start position:0% +you plot your IV curve on log linear +scale you see essentially two flat + + align:start position:0% +scale you see essentially two flat + + + align:start position:0% +scale you see essentially two flat +points on your IV curve let me for that + + align:start position:0% +points on your IV curve let me for that + + + align:start position:0% +points on your IV curve let me for that +to the next slide right here here we go + + align:start position:0% +to the next slide right here here we go + + + align:start position:0% +to the next slide right here here we go +so this is log of current versus linear + + align:start position:0% +so this is log of current versus linear + + + align:start position:0% +so this is log of current versus linear +voltage and you see one flat portion + + align:start position:0% +voltage and you see one flat portion + + + align:start position:0% +voltage and you see one flat portion +right here and another flat portion + + align:start position:0% +right here and another flat portion + + + align:start position:0% +right here and another flat portion +right here before the series resistance + + align:start position:0% +right here before the series resistance + + + align:start position:0% +right here before the series resistance +begins to dominate at two high voltage + + align:start position:0% +begins to dominate at two high voltage + + + align:start position:0% +begins to dominate at two high voltage +and your shunt resistance dominates at + + align:start position:0% +and your shunt resistance dominates at + + + align:start position:0% +and your shunt resistance dominates at +two low-voltage this flat portion right + + align:start position:0% +two low-voltage this flat portion right + + + align:start position:0% +two low-voltage this flat portion right +there is being driven by three common + + align:start position:0% +there is being driven by three common + + + align:start position:0% +there is being driven by three common +within the space charge region why well + + align:start position:0% +within the space charge region why well + + + align:start position:0% +within the space charge region why well +the forward bias voltage isn't enough to + + align:start position:0% +the forward bias voltage isn't enough to + + + align:start position:0% +the forward bias voltage isn't enough to +really lower that barrier enough to + + align:start position:0% +really lower that barrier enough to + + + align:start position:0% +really lower that barrier enough to +allow the carrier's deep within the bulk + + align:start position:0% +allow the carrier's deep within the bulk + + + align:start position:0% +allow the carrier's deep within the bulk +to recombine so the carriers are + + align:start position:0% +to recombine so the carriers are + + + align:start position:0% +to recombine so the carriers are +recombining in the space charge region + + align:start position:0% +recombining in the space charge region + + + align:start position:0% +recombining in the space charge region +whereas here they're recombining within + + align:start position:0% +whereas here they're recombining within + + + align:start position:0% +whereas here they're recombining within +the bulk all right + + align:start position:0% +the bulk all right + + + align:start position:0% +the bulk all right +so this is a more complicated expression + + align:start position:0% +so this is a more complicated expression + + + align:start position:0% +so this is a more complicated expression +for the IV characteristics of a solar + + align:start position:0% +for the IV characteristics of a solar + + + align:start position:0% +for the IV characteristics of a solar +cell device not always are these precise + + align:start position:0% +cell device not always are these precise + + + align:start position:0% +cell device not always are these precise +mechanisms at work if you have a new + + align:start position:0% +mechanisms at work if you have a new + + + align:start position:0% +mechanisms at work if you have a new +material system that you're working with + + align:start position:0% +material system that you're working with + + + align:start position:0% +material system that you're working with +there might be different recombination + + align:start position:0% +there might be different recombination + + + align:start position:0% +there might be different recombination +mechanisms at work there might be charge + + align:start position:0% +mechanisms at work there might be charge + + + align:start position:0% +mechanisms at work there might be charge +accumulation effects at work but they + + align:start position:0% +accumulation effects at work but they + + + align:start position:0% +accumulation effects at work but they +can all be encapsulated in some form of + + align:start position:0% +can all be encapsulated in some form of + + + align:start position:0% +can all be encapsulated in some form of +current voltage expression think of the + + align:start position:0% +current voltage expression think of the + + + align:start position:0% +current voltage expression think of the +IV characteristics of the solar cell + + align:start position:0% +IV characteristics of the solar cell + + + align:start position:0% +IV characteristics of the solar cell +similar to say the constitutive + + align:start position:0% +similar to say the constitutive + + + align:start position:0% +similar to say the constitutive +relations of a complex of viscoelastic + + align:start position:0% +relations of a complex of viscoelastic + + + align:start position:0% +relations of a complex of viscoelastic +material where you have say a nice + + align:start position:0% +material where you have say a nice + + + align:start position:0% +material where you have say a nice +linear elastic component a dashpot + + align:start position:0% +linear elastic component a dashpot + + + align:start position:0% +linear elastic component a dashpot +component right so you have a very + + align:start position:0% +component right so you have a very + + + align:start position:0% +component right so you have a very +complex expression describing the + + align:start position:0% +complex expression describing the + + + align:start position:0% +complex expression describing the +stress-strain relationship in material a + + align:start position:0% +stress-strain relationship in material a + + + align:start position:0% +stress-strain relationship in material a +similar thing goes on here with the + + align:start position:0% +similar thing goes on here with the + + + align:start position:0% +similar thing goes on here with the +solar cell where you're describing the + + align:start position:0% +solar cell where you're describing the + + + align:start position:0% +solar cell where you're describing the +current voltage relationship if you + + align:start position:0% +current voltage relationship if you + + + align:start position:0% +current voltage relationship if you +understand all of the mechanisms driving + + align:start position:0% +understand all of the mechanisms driving + + + align:start position:0% +understand all of the mechanisms driving +carry recombination in your material and + + align:start position:0% +carry recombination in your material and + + + align:start position:0% +carry recombination in your material and +charge separation you can come up with + + align:start position:0% +charge separation you can come up with + + + align:start position:0% +charge separation you can come up with +an expression that describes very + + align:start position:0% +an expression that describes very + + + align:start position:0% +an expression that describes very +precisely the IV characteristics but if + + align:start position:0% +precisely the IV characteristics but if + + + align:start position:0% +precisely the IV characteristics but if +you change material systems you may not + + align:start position:0% +you change material systems you may not + + + align:start position:0% +you change material systems you may not +necessarily be able to transition the + + align:start position:0% +necessarily be able to transition the + + + align:start position:0% +necessarily be able to transition the +same models over it's helpful to start + + align:start position:0% +same models over it's helpful to start + + + align:start position:0% +same models over it's helpful to start +with them but sooner or later you might + + align:start position:0% +with them but sooner or later you might + + + align:start position:0% +with them but sooner or later you might +decide well gee I have to I have to make + + align:start position:0% +decide well gee I have to I have to make + + + align:start position:0% +decide well gee I have to I have to make +some modifications all right + + align:start position:0% +some modifications all right + + + align:start position:0% +some modifications all right +okay series resistance we already + + align:start position:0% +okay series resistance we already + + + align:start position:0% +okay series resistance we already +studied this before but just a quick + + align:start position:0% +studied this before but just a quick + + + align:start position:0% +studied this before but just a quick +refresher we have the series resistance + + align:start position:0% +refresher we have the series resistance + + + align:start position:0% +refresher we have the series resistance +of the bulk we have the series + + align:start position:0% +of the bulk we have the series + + + align:start position:0% +of the bulk we have the series +resistance of the emitter and then we + + align:start position:0% +resistance of the emitter and then we + + + align:start position:0% +resistance of the emitter and then we +have the series resistance of our of the + + align:start position:0% +have the series resistance of our of the + + + align:start position:0% +have the series resistance of our of the +contacts as we contact the device and in + + align:start position:0% +contacts as we contact the device and in + + + align:start position:0% +contacts as we contact the device and in +the series resistance within the contact + + align:start position:0% +the series resistance within the contact + + + align:start position:0% +the series resistance within the contact +itself so at least four different + + align:start position:0% +itself so at least four different + + + align:start position:0% +itself so at least four different +components of series resistance in our + + align:start position:0% +components of series resistance in our + + + align:start position:0% +components of series resistance in our +device that are all lumped together when + + align:start position:0% +device that are all lumped together when + + + align:start position:0% +device that are all lumped together when +we take these when we express our IV + + align:start position:0% +we take these when we express our IV + + + align:start position:0% +we take these when we express our IV +curve in this manner we all lump them + + align:start position:0% +curve in this manner we all lump them + + + align:start position:0% +curve in this manner we all lump them +together and that R sub s yeah question + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% +to + + + align:start position:0% +to +ah yeah so um simple explanation if you + + align:start position:0% +ah yeah so um simple explanation if you + + + align:start position:0% +ah yeah so um simple explanation if you +would like is mostly where the Fermi + + align:start position:0% +would like is mostly where the Fermi + + + align:start position:0% +would like is mostly where the Fermi +energy is sitting relative to the + + align:start position:0% +energy is sitting relative to the + + + align:start position:0% +energy is sitting relative to the +conduction or valence band in the space + + align:start position:0% +conduction or valence band in the space + + + align:start position:0% +conduction or valence band in the space +charge region the quasi neutral region + + align:start position:0% +charge region the quasi neutral region + + + align:start position:0% +charge region the quasi neutral region +is closer to mid gap as opposed to + + align:start position:0% +is closer to mid gap as opposed to + + + align:start position:0% +is closer to mid gap as opposed to +closer to bandage hand-wavy + + align:start position:0% +closer to bandage hand-wavy + + + align:start position:0% +closer to bandage hand-wavy +if you really want to get into it I + + align:start position:0% +if you really want to get into it I + + + align:start position:0% +if you really want to get into it I +spent about three months studying this + + align:start position:0% +spent about three months studying this + + + align:start position:0% +spent about three months studying this +as a graduate student the the one in the + + align:start position:0% +as a graduate student the the one in the + + + align:start position:0% +as a graduate student the the one in the +to the ideology factor which is to show + + align:start position:0% +to the ideology factor which is to show + + + align:start position:0% +to the ideology factor which is to show +more precisely it's the number that + + align:start position:0% +more precisely it's the number that + + + align:start position:0% +more precisely it's the number that +comes before the KT right for each of + + align:start position:0% +comes before the KT right for each of + + + align:start position:0% +comes before the KT right for each of +these that's called the ideology factor + + align:start position:0% +these that's called the ideology factor + + + align:start position:0% +these that's called the ideology factor +it's typically expressed as n sub 1 or n + + align:start position:0% +it's typically expressed as n sub 1 or n + + + align:start position:0% +it's typically expressed as n sub 1 or n +sub 2 in this case I just substituted it + + align:start position:0% +sub 2 in this case I just substituted it + + + align:start position:0% +sub 2 in this case I just substituted it +straight out for a 1 and a 2 those + + align:start position:0% +straight out for a 1 and a 2 those + + + align:start position:0% +straight out for a 1 and a 2 those +numbers aren't always 1 and 2 as a + + align:start position:0% +numbers aren't always 1 and 2 as a + + + align:start position:0% +numbers aren't always 1 and 2 as a +matter of fact especially the G naught 1 + + align:start position:0% +matter of fact especially the G naught 1 + + + align:start position:0% +matter of fact especially the G naught 1 +the bulk recombination current depending + + align:start position:0% +the bulk recombination current depending + + + align:start position:0% +the bulk recombination current depending +on where the defect levels lie it can be + + align:start position:0% +on where the defect levels lie it can be + + + align:start position:0% +on where the defect levels lie it can be +somewhere between say a 1.1 and a 1.4 + + align:start position:0% +somewhere between say a 1.1 and a 1.4 + + + align:start position:0% +somewhere between say a 1.1 and a 1.4 +typically and beautiful thesis work done + + align:start position:0% +typically and beautiful thesis work done + + + align:start position:0% +typically and beautiful thesis work done +by fellow in in Australia hold on Keith + + align:start position:0% +by fellow in in Australia hold on Keith + + + align:start position:0% +by fellow in in Australia hold on Keith +McIntosh and the title of the thesis is + + align:start position:0% +McIntosh and the title of the thesis is + + + align:start position:0% +McIntosh and the title of the thesis is +called humps bumps and lumps it's all + + align:start position:0% +called humps bumps and lumps it's all + + + align:start position:0% +called humps bumps and lumps it's all +about non idealities within an IV curve + + align:start position:0% +about non idealities within an IV curve + + + align:start position:0% +about non idealities within an IV curve +so if you really curious about that + + align:start position:0% +so if you really curious about that + + + align:start position:0% +so if you really curious about that +humps bumps and lumps bye-bye McIntosh I + + align:start position:0% +humps bumps and lumps bye-bye McIntosh I + + + align:start position:0% +humps bumps and lumps bye-bye McIntosh I +believe was the name okay so we talked + + align:start position:0% +believe was the name okay so we talked + + + align:start position:0% +believe was the name okay so we talked +about series resistance already hold + + align:start position:0% +about series resistance already hold + + + align:start position:0% +about series resistance already hold +that put that in your RAM that's our R + + align:start position:0% +that put that in your RAM that's our R + + + align:start position:0% +that put that in your RAM that's our R +sub s right over here that's our R sub s + + align:start position:0% +sub s right over here that's our R sub s + + + align:start position:0% +sub s right over here that's our R sub s +and our our shunt you want to hold this + + align:start position:0% +and our our shunt you want to hold this + + + align:start position:0% +and our our shunt you want to hold this +other component near ram so that's the + + align:start position:0% +other component near ram so that's the + + + align:start position:0% +other component near ram so that's the +picture to have our series this is our + + align:start position:0% +picture to have our series this is our + + + align:start position:0% +picture to have our series this is our +shunt this is an IV sorry a pn-junction + + align:start position:0% +shunt this is an IV sorry a pn-junction + + + align:start position:0% +shunt this is an IV sorry a pn-junction +this is your n plus region and this is + + align:start position:0% +this is your n plus region and this is + + + align:start position:0% +this is your n plus region and this is +your p and this is looking at the + + align:start position:0% +your p and this is looking at the + + + align:start position:0% +your p and this is looking at the +electron energy in 3d so we typically + + align:start position:0% +electron energy in 3d so we typically + + + align:start position:0% +electron energy in 3d so we typically +take a slice out like that right just + + align:start position:0% +take a slice out like that right just + + + align:start position:0% +take a slice out like that right just +like this and we draw the electron + + align:start position:0% +like this and we draw the electron + + + align:start position:0% +like this and we draw the electron +energy as a function of position in a + + align:start position:0% +energy as a function of position in a + + + align:start position:0% +energy as a function of position in a +nice little wavy form that we typically + + align:start position:0% +nice little wavy form that we typically + + + align:start position:0% +nice little wavy form that we typically +do to create describe the PN Junction + + align:start position:0% +do to create describe the PN Junction + + + align:start position:0% +do to create describe the PN Junction +what's being described right here is + + align:start position:0% +what's being described right here is + + + align:start position:0% +what's being described right here is +adding a leaner dimension a spatial + + align:start position:0% +adding a leaner dimension a spatial + + + align:start position:0% +adding a leaner dimension a spatial +dimension in what's shown as the + + align:start position:0% +dimension in what's shown as the + + + align:start position:0% +dimension in what's shown as the +abscissa and this plot and showing what + + align:start position:0% +abscissa and this plot and showing what + + + align:start position:0% +abscissa and this plot and showing what +is a weakness in the PN Junction it + + align:start position:0% +is a weakness in the PN Junction it + + + align:start position:0% +is a weakness in the PN Junction it +could be a localized defect this could + + align:start position:0% +could be a localized defect this could + + + align:start position:0% +could be a localized defect this could +be a + + align:start position:0% +be a + + + align:start position:0% +be a +art of metal that happened to lie on the + + align:start position:0% +art of metal that happened to lie on the + + + align:start position:0% +art of metal that happened to lie on the +wrong place in your device and poke and + + align:start position:0% +wrong place in your device and poke and + + + align:start position:0% +wrong place in your device and poke and +fire through essentially when you did + + align:start position:0% +fire through essentially when you did + + + align:start position:0% +fire through essentially when you did +the firing step to adhere the metal to + + align:start position:0% +the firing step to adhere the metal to + + + align:start position:0% +the firing step to adhere the metal to +create the contact it could have gone + + align:start position:0% +create the contact it could have gone + + + align:start position:0% +create the contact it could have gone +straight through the pn-junction contact + + align:start position:0% +straight through the pn-junction contact + + + align:start position:0% +straight through the pn-junction contact +to the other side it could be a charge + + align:start position:0% +to the other side it could be a charge + + + align:start position:0% +to the other side it could be a charge +dislocation it could be a structural + + align:start position:0% +dislocation it could be a structural + + + align:start position:0% +dislocation it could be a structural +defect and so forth but a local + + align:start position:0% +defect and so forth but a local + + + align:start position:0% +defect and so forth but a local +reduction in the barrier height now + + align:start position:0% +reduction in the barrier height now + + + align:start position:0% +reduction in the barrier height now +where the SI electron going to go if you + + align:start position:0% +where the SI electron going to go if you + + + align:start position:0% +where the SI electron going to go if you +have a diffusion current it's going to + + align:start position:0% +have a diffusion current it's going to + + + align:start position:0% +have a diffusion current it's going to +be crowding through that little + + align:start position:0% +be crowding through that little + + + align:start position:0% +be crowding through that little +localized reduction in the energy + + align:start position:0% +localized reduction in the energy + + + align:start position:0% +localized reduction in the energy +barrier and you're going to have a + + align:start position:0% +barrier and you're going to have a + + + align:start position:0% +barrier and you're going to have a +higher current flowing through the + + align:start position:0% +higher current flowing through the + + + align:start position:0% +higher current flowing through the +specific region so how to measure that + + align:start position:0% +specific region so how to measure that + + + align:start position:0% +specific region so how to measure that +well if I measure my full IV curve like + + align:start position:0% +well if I measure my full IV curve like + + + align:start position:0% +well if I measure my full IV curve like +this might manifest itself as some + + align:start position:0% +this might manifest itself as some + + + align:start position:0% +this might manifest itself as some +reduced shunt resistance so you have a + + align:start position:0% +reduced shunt resistance so you have a + + + align:start position:0% +reduced shunt resistance so you have a +larger current flowing through it at + + align:start position:0% +larger current flowing through it at + + + align:start position:0% +larger current flowing through it at +lower bias voltages but but how do I + + align:start position:0% +lower bias voltages but but how do I + + + align:start position:0% +lower bias voltages but but how do I +know what's going on without some + + align:start position:0% +know what's going on without some + + + align:start position:0% +know what's going on without some +spatial a spatially resolved measurement + + align:start position:0% +spatial a spatially resolved measurement + + + align:start position:0% +spatial a spatially resolved measurement +tool I'm in the dark no pun intended + + align:start position:0% +tool I'm in the dark no pun intended + + + align:start position:0% +tool I'm in the dark no pun intended +so I have to figure out how to measure + + align:start position:0% +so I have to figure out how to measure + + + align:start position:0% +so I have to figure out how to measure +the current flow as a function of + + align:start position:0% +the current flow as a function of + + + align:start position:0% +the current flow as a function of +position now somebody thought about this + + align:start position:0% +position now somebody thought about this + + + align:start position:0% +position now somebody thought about this +a while they said huh well let me get + + align:start position:0% +a while they said huh well let me get + + + align:start position:0% +a while they said huh well let me get +this straight if I apply a known bias + + align:start position:0% +this straight if I apply a known bias + + + align:start position:0% +this straight if I apply a known bias +voltage to my device I'm going to get + + align:start position:0% +voltage to my device I'm going to get + + + align:start position:0% +voltage to my device I'm going to get +some current flowing through it and that + + align:start position:0% +some current flowing through it and that + + + align:start position:0% +some current flowing through it and that +current what I read out of the whole + + align:start position:0% +current what I read out of the whole + + + align:start position:0% +current what I read out of the whole +device macroscopically has some spatial + + align:start position:0% +device macroscopically has some spatial + + + align:start position:0% +device macroscopically has some spatial +distribution to it let me think about + + align:start position:0% +distribution to it let me think about + + + align:start position:0% +distribution to it let me think about +this + + align:start position:0% +this + + + align:start position:0% +this +okay so current times voltage is power + + align:start position:0% +okay so current times voltage is power + + + align:start position:0% +okay so current times voltage is power +right and power generates Heat so if I + + align:start position:0% +right and power generates Heat so if I + + + align:start position:0% +right and power generates Heat so if I +have a current crowding at some portion + + align:start position:0% +have a current crowding at some portion + + + align:start position:0% +have a current crowding at some portion +of my device I'm going to be generating + + align:start position:0% +of my device I'm going to be generating + + + align:start position:0% +of my device I'm going to be generating +a large amount of heat as the carriers + + align:start position:0% +a large amount of heat as the carriers + + + align:start position:0% +a large amount of heat as the carriers +flow through that specific region so if + + align:start position:0% +flow through that specific region so if + + + align:start position:0% +flow through that specific region so if +I have some method of measuring the heat + + align:start position:0% +I have some method of measuring the heat + + + align:start position:0% +I have some method of measuring the heat +heat distribution across my device is + + align:start position:0% +heat distribution across my device is + + + align:start position:0% +heat distribution across my device is +very very sensitive I might be able to + + align:start position:0% +very very sensitive I might be able to + + + align:start position:0% +very very sensitive I might be able to +divide that heat measurement if + + align:start position:0% +divide that heat measurement if + + + align:start position:0% +divide that heat measurement if +calibrated properly to determine total + + align:start position:0% +calibrated properly to determine total + + + align:start position:0% +calibrated properly to determine total +power I might be able to divide that + + align:start position:0% +power I might be able to divide that + + + align:start position:0% +power I might be able to divide that +heat measurement by current sorry by + + align:start position:0% +heat measurement by current sorry by + + + align:start position:0% +heat measurement by current sorry by +voltage by voltage so I know the applied + + align:start position:0% +voltage by voltage so I know the applied + + + align:start position:0% +voltage by voltage so I know the applied +bias voltage to my device I take my + + align:start position:0% +bias voltage to my device I take my + + + align:start position:0% +bias voltage to my device I take my +power divided by the voltage and I get + + align:start position:0% +power divided by the voltage and I get + + + align:start position:0% +power divided by the voltage and I get +the current as a function of X Y + + align:start position:0% +the current as a function of X Y + + + align:start position:0% +the current as a function of X Y +position so I can map out my dark IV + + align:start position:0% +position so I can map out my dark IV + + + align:start position:0% +position so I can map out my dark IV +curve at any arbitrary bias voltage + + align:start position:0% +curve at any arbitrary bias voltage + + + align:start position:0% +curve at any arbitrary bias voltage +condition let's say I want to do the + + align:start position:0% +condition let's say I want to do the + + + align:start position:0% +condition let's say I want to do the +measurement at point 4 volts for bias I + + align:start position:0% +measurement at point 4 volts for bias I + + + align:start position:0% +measurement at point 4 volts for bias I +apply point 4 volts across my device and + + align:start position:0% +apply point 4 volts across my device and + + + align:start position:0% +apply point 4 volts across my device and +I just measure the heat distribution and + + align:start position:0% +I just measure the heat distribution and + + + align:start position:0% +I just measure the heat distribution and +in a calibrated measurement you can see + + align:start position:0% +in a calibrated measurement you can see + + + align:start position:0% +in a calibrated measurement you can see +how the dark current is distributed + + align:start position:0% +how the dark current is distributed + + + align:start position:0% +how the dark current is distributed +and how the diffusion current is + + align:start position:0% +and how the diffusion current is + + + align:start position:0% +and how the diffusion current is +distributed and that's what lock-in + + align:start position:0% +distributed and that's what lock-in + + + align:start position:0% +distributed and that's what lock-in +thermography is all about this is a say + + align:start position:0% +thermography is all about this is a say + + + align:start position:0% +thermography is all about this is a say +a somewhat typical image not it's still + + align:start position:0% +a somewhat typical image not it's still + + + align:start position:0% +a somewhat typical image not it's still +very noisy because it was a very fast + + align:start position:0% +very noisy because it was a very fast + + + align:start position:0% +very noisy because it was a very fast +image but you have your solar cell + + align:start position:0% +image but you have your solar cell + + + align:start position:0% +image but you have your solar cell +device you can barely make out the + + align:start position:0% +device you can barely make out the + + + align:start position:0% +device you can barely make out the +contact grid right here and then the + + align:start position:0% +contact grid right here and then the + + + align:start position:0% +contact grid right here and then the +fingers are moving down separated by + + align:start position:0% +fingers are moving down separated by + + + align:start position:0% +fingers are moving down separated by +about this much on this particular image + + align:start position:0% +about this much on this particular image + + + align:start position:0% +about this much on this particular image +you can see the fingers or the dark + + align:start position:0% +you can see the fingers or the dark + + + align:start position:0% +you can see the fingers or the dark +shadow of the fingers right here and you + + align:start position:0% +shadow of the fingers right here and you + + + align:start position:0% +shadow of the fingers right here and you +see bright spots 1 2 3 4 5 6 7 and so + + align:start position:0% +see bright spots 1 2 3 4 5 6 7 and so + + + align:start position:0% +see bright spots 1 2 3 4 5 6 7 and so +forth across the device indicating + + align:start position:0% +forth across the device indicating + + + align:start position:0% +forth across the device indicating +regions were more current is flowing aha + + align:start position:0% +regions were more current is flowing aha + + + align:start position:0% +regions were more current is flowing aha +so I'm beginning to figure out that well + + align:start position:0% +so I'm beginning to figure out that well + + + align:start position:0% +so I'm beginning to figure out that well +this dark IV curve that I have right + + align:start position:0% +this dark IV curve that I have right + + + align:start position:0% +this dark IV curve that I have right +here this large amount of current + + align:start position:0% +here this large amount of current + + + align:start position:0% +here this large amount of current +flowing through my device at lower bias + + align:start position:0% +flowing through my device at lower bias + + + align:start position:0% +flowing through my device at lower bias +voltages that's not all uniformly + + align:start position:0% +voltages that's not all uniformly + + + align:start position:0% +voltages that's not all uniformly +distributed but it's rather concentrated + + align:start position:0% +distributed but it's rather concentrated + + + align:start position:0% +distributed but it's rather concentrated +in specific areas where I have + + align:start position:0% +in specific areas where I have + + + align:start position:0% +in specific areas where I have +weaknesses in my PN Junction under low + + align:start position:0% +weaknesses in my PN Junction under low + + + align:start position:0% +weaknesses in my PN Junction under low +forward bias voltages and at larger + + align:start position:0% +forward bias voltages and at larger + + + align:start position:0% +forward bias voltages and at larger +forward bias voltages once this barrier + + align:start position:0% +forward bias voltages once this barrier + + + align:start position:0% +forward bias voltages once this barrier +significantly reduced I may have more + + align:start position:0% +significantly reduced I may have more + + + align:start position:0% +significantly reduced I may have more +carriers going through in regions of + + align:start position:0% +carriers going through in regions of + + + align:start position:0% +carriers going through in regions of +smaller minority carrier diffusion + + align:start position:0% +smaller minority carrier diffusion + + + align:start position:0% +smaller minority carrier diffusion +length why well because if a carrier + + align:start position:0% +length why well because if a carrier + + + align:start position:0% +length why well because if a carrier +goes in and recombines quickly because + + align:start position:0% +goes in and recombines quickly because + + + align:start position:0% +goes in and recombines quickly because +the diffusion length is very short that + + align:start position:0% +the diffusion length is very short that + + + align:start position:0% +the diffusion length is very short that +means there's one less carrier in there + + align:start position:0% +means there's one less carrier in there + + + align:start position:0% +means there's one less carrier in there +which means that now there's a greater + + align:start position:0% +which means that now there's a greater + + + align:start position:0% +which means that now there's a greater +driving force for diffusion and another + + align:start position:0% +driving force for diffusion and another + + + align:start position:0% +driving force for diffusion and another +carrier is going to come in and + + align:start position:0% +carrier is going to come in and + + + align:start position:0% +carrier is going to come in and +recombine too and another carrier and + + align:start position:0% +recombine too and another carrier and + + + align:start position:0% +recombine too and another carrier and +recombine too right so now you have a + + align:start position:0% +recombine too right so now you have a + + + align:start position:0% +recombine too right so now you have a +larger diffusion current going into the + + align:start position:0% +larger diffusion current going into the + + + align:start position:0% +larger diffusion current going into the +regions of lower minority carrier + + align:start position:0% +regions of lower minority carrier + + + align:start position:0% +regions of lower minority carrier +diffusion length let's look at a few + + align:start position:0% +diffusion length let's look at a few + + + align:start position:0% +diffusion length let's look at a few +lock-in thermography images and see how + + align:start position:0% +lock-in thermography images and see how + + + align:start position:0% +lock-in thermography images and see how +this this this plays out so under low + + align:start position:0% +this this this plays out so under low + + + align:start position:0% +this this this plays out so under low +bias conditions so I'm still still have + + align:start position:0% +bias conditions so I'm still still have + + + align:start position:0% +bias conditions so I'm still still have +a very large barrier there in the in the + + align:start position:0% +a very large barrier there in the in the + + + align:start position:0% +a very large barrier there in the in the +PN Junction region I'm typically going + + align:start position:0% +PN Junction region I'm typically going + + + align:start position:0% +PN Junction region I'm typically going +to see isolated hot spots not always but + + align:start position:0% +to see isolated hot spots not always but + + + align:start position:0% +to see isolated hot spots not always but +but typically isolated hot spots and + + align:start position:0% +but typically isolated hot spots and + + + align:start position:0% +but typically isolated hot spots and +these most often are defects within the + + align:start position:0% +these most often are defects within the + + + align:start position:0% +these most often are defects within the +PN Junction somebody might scratch the + + align:start position:0% +PN Junction somebody might scratch the + + + align:start position:0% +PN Junction somebody might scratch the +junction or maybe drop their tweezer on + + align:start position:0% +junction or maybe drop their tweezer on + + + align:start position:0% +junction or maybe drop their tweezer on +it or maybe a piece of metal during the + + align:start position:0% +it or maybe a piece of metal during the + + + align:start position:0% +it or maybe a piece of metal during the +contact metallization fired through at + + align:start position:0% +contact metallization fired through at + + + align:start position:0% +contact metallization fired through at +that particular region and so we have + + align:start position:0% +that particular region and so we have + + + align:start position:0% +that particular region and so we have +what are typically these point shunts + + align:start position:0% +what are typically these point shunts + + + align:start position:0% +what are typically these point shunts +sometimes you see shunts around the edge + + align:start position:0% +sometimes you see shunts around the edge + + + align:start position:0% +sometimes you see shunts around the edge +as well if you didn't isolate the edge + + align:start position:0% +as well if you didn't isolate the edge + + + align:start position:0% +as well if you didn't isolate the edge +well and it now as we forward bias + + align:start position:0% +well and it now as we forward bias + + + align:start position:0% +well and it now as we forward bias +forward biased forward bias those + + align:start position:0% +forward biased forward bias those + + + align:start position:0% +forward biased forward bias those +barriers become less + + align:start position:0% +barriers become less + + + align:start position:0% +barriers become less +and now what's driving the current the + + align:start position:0% +and now what's driving the current the + + + align:start position:0% +and now what's driving the current the +dark current in the device is a + + align:start position:0% +dark current in the device is a + + + align:start position:0% +dark current in the device is a +recombination in the bulk so the regions + + align:start position:0% +recombination in the bulk so the regions + + + align:start position:0% +recombination in the bulk so the regions +of higher recombination will be regions + + align:start position:0% +of higher recombination will be regions + + + align:start position:0% +of higher recombination will be regions +of higher current flow they'll drive + + align:start position:0% +of higher current flow they'll drive + + + align:start position:0% +of higher current flow they'll drive +more recombination current so this is a + + align:start position:0% +more recombination current so this is a + + + align:start position:0% +more recombination current so this is a +higher bias voltage 560 millivolts or + + align:start position:0% +higher bias voltage 560 millivolts or + + + align:start position:0% +higher bias voltage 560 millivolts or +0.5 6 volts as opposed to 0.36 volts we + + align:start position:0% +0.5 6 volts as opposed to 0.36 volts we + + + align:start position:0% +0.5 6 volts as opposed to 0.36 volts we +can still see the shadow of the big 3 + + align:start position:0% +can still see the shadow of the big 3 + + + align:start position:0% +can still see the shadow of the big 3 +right here but they're they're much + + align:start position:0% +right here but they're they're much + + + align:start position:0% +right here but they're they're much +diminished now instead what we see are + + align:start position:0% +diminished now instead what we see are + + + align:start position:0% +diminished now instead what we see are +these wispier features right here now I + + align:start position:0% +these wispier features right here now I + + + align:start position:0% +these wispier features right here now I +think gee if that really is if those + + align:start position:0% +think gee if that really is if those + + + align:start position:0% +think gee if that really is if those +really are regions of lower minority + + align:start position:0% +really are regions of lower minority + + + align:start position:0% +really are regions of lower minority +carrier diffusion life I just learned + + align:start position:0% +carrier diffusion life I just learned + + + align:start position:0% +carrier diffusion life I just learned +about a method to measure might already + + align:start position:0% +about a method to measure might already + + + align:start position:0% +about a method to measure might already +care diffusion length didn't I what was + + align:start position:0% +care diffusion length didn't I what was + + + align:start position:0% +care diffusion length didn't I what was +that laser beam induced current method + + align:start position:0% +that laser beam induced current method + + + align:start position:0% +that laser beam induced current method +right spatially resolved laser beam + + align:start position:0% +right spatially resolved laser beam + + + align:start position:0% +right spatially resolved laser beam +discard so I have at least one method of + + align:start position:0% +discard so I have at least one method of + + + align:start position:0% +discard so I have at least one method of +measuring minority carrier diffusion + + align:start position:0% +measuring minority carrier diffusion + + + align:start position:0% +measuring minority carrier diffusion +length let's put one and one together + + align:start position:0% +length let's put one and one together + + + align:start position:0% +length let's put one and one together +and see what we get so we'll take this + + align:start position:0% +and see what we get so we'll take this + + + align:start position:0% +and see what we get so we'll take this +image right here and put it aside rotate + + align:start position:0% +image right here and put it aside rotate + + + align:start position:0% +image right here and put it aside rotate +it and put it right beside the minority + + align:start position:0% +it and put it right beside the minority + + + align:start position:0% +it and put it right beside the minority +carrier diffusion length and voila you + + align:start position:0% +carrier diffusion length and voila you + + + align:start position:0% +carrier diffusion length and voila you +see how those wispier features are + + align:start position:0% +see how those wispier features are + + + align:start position:0% +see how those wispier features are +corresponding to regions of lower + + align:start position:0% +corresponding to regions of lower + + + align:start position:0% +corresponding to regions of lower +minority carrier diffusion length once + + align:start position:0% +minority carrier diffusion length once + + + align:start position:0% +minority carrier diffusion length once +again the explanation if you have large + + align:start position:0% +again the explanation if you have large + + + align:start position:0% +again the explanation if you have large +forward bias condition the barrier is + + align:start position:0% +forward bias condition the barrier is + + + align:start position:0% +forward bias condition the barrier is +lower carriers can easily diffuse into + + align:start position:0% +lower carriers can easily diffuse into + + + align:start position:0% +lower carriers can easily diffuse into +the bulk the carrier's diffusing into + + align:start position:0% +the bulk the carrier's diffusing into + + + align:start position:0% +the bulk the carrier's diffusing into +the bulk will go a certain distance + + align:start position:0% +the bulk will go a certain distance + + + align:start position:0% +the bulk will go a certain distance +before recombining if the diffusion + + align:start position:0% +before recombining if the diffusion + + + align:start position:0% +before recombining if the diffusion +length is short the recombine quickly + + align:start position:0% +length is short the recombine quickly + + + align:start position:0% +length is short the recombine quickly +which means now there's no more carrier + + align:start position:0% +which means now there's no more carrier + + + align:start position:0% +which means now there's no more carrier +which means that the diffusion current + + align:start position:0% +which means that the diffusion current + + + align:start position:0% +which means that the diffusion current +will push another carrier into that spot + + align:start position:0% +will push another carrier into that spot + + + align:start position:0% +will push another carrier into that spot +right which means will recombine + + align:start position:0% +right which means will recombine + + + align:start position:0% +right which means will recombine +recombine more current is flowing + + align:start position:0% +recombine more current is flowing + + + align:start position:0% +recombine more current is flowing +through if the diffusion length is + + align:start position:0% +through if the diffusion length is + + + align:start position:0% +through if the diffusion length is +shorter the alternative is a diffusion + + align:start position:0% +shorter the alternative is a diffusion + + + align:start position:0% +shorter the alternative is a diffusion +length is long and one carrier makes it + + align:start position:0% +length is long and one carrier makes it + + + align:start position:0% +length is long and one carrier makes it +over and then takes its time getting all + + align:start position:0% +over and then takes its time getting all + + + align:start position:0% +over and then takes its time getting all +the way across before recombination + + align:start position:0% +the way across before recombination + + + align:start position:0% +the way across before recombination +occurs so what you're seeing here is + + align:start position:0% +occurs so what you're seeing here is + + + align:start position:0% +occurs so what you're seeing here is +essentially in effect the current the + + align:start position:0% +essentially in effect the current the + + + align:start position:0% +essentially in effect the current the +the dark forward current meaning you're + + align:start position:0% +the dark forward current meaning you're + + + align:start position:0% +the dark forward current meaning you're +measuring the IV curve in the dark + + align:start position:0% +measuring the IV curve in the dark + + + align:start position:0% +measuring the IV curve in the dark +you're obtaining an IV curve here it is + + align:start position:0% +you're obtaining an IV curve here it is + + + align:start position:0% +you're obtaining an IV curve here it is +you're obtaining an IV curve for your + + align:start position:0% +you're obtaining an IV curve for your + + + align:start position:0% +you're obtaining an IV curve for your +device you're measuring in the dark + + align:start position:0% +device you're measuring in the dark + + + align:start position:0% +device you're measuring in the dark +under larger forward bias conditions + + align:start position:0% +under larger forward bias conditions + + + align:start position:0% +under larger forward bias conditions +somewhere out here where bulk + + align:start position:0% +somewhere out here where bulk + + + align:start position:0% +somewhere out here where bulk +recombination is dominating and you're + + align:start position:0% +recombination is dominating and you're + + + align:start position:0% +recombination is dominating and you're +able to visualize the current loss + + align:start position:0% +able to visualize the current loss + + + align:start position:0% +able to visualize the current loss +mechanisms in your device so you say + + align:start position:0% +mechanisms in your device so you say + + + align:start position:0% +mechanisms in your device so you say +well gee if I want in the dark if I want + + align:start position:0% +well gee if I want in the dark if I want + + + align:start position:0% +well gee if I want in the dark if I want +this to be as small as possible so that + + align:start position:0% +this to be as small as possible so that + + + align:start position:0% +this to be as small as possible so that +when I transpose this + + align:start position:0% +when I transpose this + + + align:start position:0% +when I transpose this +delight and I shift everything into + + align:start position:0% +delight and I shift everything into + + + align:start position:0% +delight and I shift everything into +negative into fourth quadrant territory + + align:start position:0% +negative into fourth quadrant territory + + + align:start position:0% +negative into fourth quadrant territory +because I illuminate it now if I want + + align:start position:0% +because I illuminate it now if I want + + + align:start position:0% +because I illuminate it now if I want +there to be a small dark forward current + + align:start position:0% +there to be a small dark forward current + + + align:start position:0% +there to be a small dark forward current +as possible so as I maximize my fill + + align:start position:0% +as possible so as I maximize my fill + + + align:start position:0% +as possible so as I maximize my fill +factor when I illuminate my device I + + align:start position:0% +factor when I illuminate my device I + + + align:start position:0% +factor when I illuminate my device I +want all of these current loss + + align:start position:0% +want all of these current loss + + + align:start position:0% +want all of these current loss +mechanisms to go away let me let me + + align:start position:0% +mechanisms to go away let me let me + + + align:start position:0% +mechanisms to go away let me let me +repeat that one more time so people get + + align:start position:0% +repeat that one more time so people get + + + align:start position:0% +repeat that one more time so people get +it if so what I'm doing right now is I'm + + align:start position:0% +it if so what I'm doing right now is I'm + + + align:start position:0% +it if so what I'm doing right now is I'm +measuring this device in the dark and + + align:start position:0% +measuring this device in the dark and + + + align:start position:0% +measuring this device in the dark and +this is my IV curve right here and I + + align:start position:0% +this is my IV curve right here and I + + + align:start position:0% +this is my IV curve right here and I +have example of bad device good device + + align:start position:0% +have example of bad device good device + + + align:start position:0% +have example of bad device good device +the bad device has so bad and good the + + align:start position:0% +the bad device has so bad and good the + + + align:start position:0% +the bad device has so bad and good the +reason this is bad and good is because + + align:start position:0% +reason this is bad and good is because + + + align:start position:0% +reason this is bad and good is because +when I transpose this curve under + + align:start position:0% +when I transpose this curve under + + + align:start position:0% +when I transpose this curve under +illumination this is now under + + align:start position:0% +illumination this is now under + + + align:start position:0% +illumination this is now under +illumination my good and bad right here + + align:start position:0% +illumination my good and bad right here + + + align:start position:0% +illumination my good and bad right here +you'll see that the bad has a lower vo C + + align:start position:0% +you'll see that the bad has a lower vo C + + + align:start position:0% +you'll see that the bad has a lower vo C +right so the intersection between these + + align:start position:0% +right so the intersection between these + + + align:start position:0% +right so the intersection between these +illuminated curves this is now + + align:start position:0% +illuminated curves this is now + + + align:start position:0% +illuminated curves this is now +illuminated and this is dark right over + + align:start position:0% +illuminated and this is dark right over + + + align:start position:0% +illuminated and this is dark right over +here these are dark curves these here + + align:start position:0% +here these are dark curves these here + + + align:start position:0% +here these are dark curves these here +are illuminated curves the intersection + + align:start position:0% +are illuminated curves the intersection + + + align:start position:0% +are illuminated curves the intersection +between the illuminated curve and the + + align:start position:0% +between the illuminated curve and the + + + align:start position:0% +between the illuminated curve and the +x-axis denotes the open circuit voltage + + align:start position:0% +x-axis denotes the open circuit voltage + + + align:start position:0% +x-axis denotes the open circuit voltage +and you see that the larger this current + + align:start position:0% +and you see that the larger this current + + + align:start position:0% +and you see that the larger this current +is in the dark the earlier you're going + + align:start position:0% +is in the dark the earlier you're going + + + align:start position:0% +is in the dark the earlier you're going +to intersect with your x-axis the lower + + align:start position:0% +to intersect with your x-axis the lower + + + align:start position:0% +to intersect with your x-axis the lower +the voltage output of your device will + + align:start position:0% +the voltage output of your device will + + + align:start position:0% +the voltage output of your device will +be the lower the maximum power point + + align:start position:0% +be the lower the maximum power point + + + align:start position:0% +be the lower the maximum power point +will be right so you want in in the dark + + align:start position:0% +will be right so you want in in the dark + + + align:start position:0% +will be right so you want in in the dark +when you measure the IV curve you want + + align:start position:0% +when you measure the IV curve you want + + + align:start position:0% +when you measure the IV curve you want +that current to be as small as possible + + align:start position:0% +that current to be as small as possible + + + align:start position:0% +that current to be as small as possible +in the dark and obviously when you + + align:start position:0% +in the dark and obviously when you + + + align:start position:0% +in the dark and obviously when you +illuminate it you want this jump to be + + align:start position:0% +illuminate it you want this jump to be + + + align:start position:0% +illuminate it you want this jump to be +as large as possible and you want this + + align:start position:0% +as large as possible and you want this + + + align:start position:0% +as large as possible and you want this +to almost look like a box that a large + + align:start position:0% +to almost look like a box that a large + + + align:start position:0% +to almost look like a box that a large +fill factor so if we say okay we want + + align:start position:0% +fill factor so if we say okay we want + + + align:start position:0% +fill factor so if we say okay we want +this to be small because we want a large + + align:start position:0% +this to be small because we want a large + + + align:start position:0% +this to be small because we want a large +fill factor somehow we have to know + + align:start position:0% +fill factor somehow we have to know + + + align:start position:0% +fill factor somehow we have to know +where the current loss mechanisms are + + align:start position:0% +where the current loss mechanisms are + + + align:start position:0% +where the current loss mechanisms are +occurring and that's where we have our + + align:start position:0% +occurring and that's where we have our + + + align:start position:0% +occurring and that's where we have our +lock-in thermography available to us we + + align:start position:0% +lock-in thermography available to us we + + + align:start position:0% +lock-in thermography available to us we +can visualize it you say well you know + + align:start position:0% +can visualize it you say well you know + + + align:start position:0% +can visualize it you say well you know +to do lock-in thermography well I'm + + align:start position:0% +to do lock-in thermography well I'm + + + align:start position:0% +to do lock-in thermography well I'm +going to need in indium antimonide sorry + + align:start position:0% +going to need in indium antimonide sorry + + + align:start position:0% +going to need in indium antimonide sorry +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +that would be it would be a in indium + + align:start position:0% +that would be it would be a in indium + + + align:start position:0% +that would be it would be a in indium +antimonide camera sensitive to the 3 to + + align:start position:0% +antimonide camera sensitive to the 3 to + + + align:start position:0% +antimonide camera sensitive to the 3 to +5 micron wavelength range that might + + align:start position:0% +5 micron wavelength range that might + + + align:start position:0% +5 micron wavelength range that might +cost $70,000 to get a good one high + + align:start position:0% +cost $70,000 to get a good one high + + + align:start position:0% +cost $70,000 to get a good one high +frame rate the locking systems so forth + + align:start position:0% +frame rate the locking systems so forth + + + align:start position:0% +frame rate the locking systems so forth +that money I can go over and borrow + + align:start position:0% +that money I can go over and borrow + + + align:start position:0% +that money I can go over and borrow +professor blown a cc system and use it + + align:start position:0% +professor blown a cc system and use it + + + align:start position:0% +professor blown a cc system and use it +there or if my shunts are big enough I + + align:start position:0% +there or if my shunts are big enough I + + + align:start position:0% +there or if my shunts are big enough I +can just use straight-out liquid crystal + + align:start position:0% +can just use straight-out liquid crystal + + + align:start position:0% +can just use straight-out liquid crystal +thermionic sheets or thermochromic + + align:start position:0% +thermionic sheets or thermochromic + + + align:start position:0% +thermionic sheets or thermochromic +sheets rather sorry so you can take + + align:start position:0% +sheets rather sorry so you can take + + + align:start position:0% +sheets rather sorry so you can take +these liquid crystals and slap them + + align:start position:0% +these liquid crystals and slap them + + + align:start position:0% +these liquid crystals and slap them +against your device and measure the heat + + align:start position:0% +against your device and measure the heat + + + align:start position:0% +against your device and measure the heat +distribution straight up just by making + + align:start position:0% +distribution straight up just by making + + + align:start position:0% +distribution straight up just by making +sure you have good thermal contact + + align:start position:0% +sure you have good thermal contact + + + align:start position:0% +sure you have good thermal contact +between yourself and your thermochromic + + align:start position:0% +between yourself and your thermochromic + + + align:start position:0% +between yourself and your thermochromic +sheets which cost about a hundred + + align:start position:0% +sheets which cost about a hundred + + + align:start position:0% +sheets which cost about a hundred +dollars now the reason we use the + + align:start position:0% +dollars now the reason we use the + + + align:start position:0% +dollars now the reason we use the +lock-in thermography and not these + + align:start position:0% +lock-in thermography and not these + + + align:start position:0% +lock-in thermography and not these +thermochromic sheets is this curve right + + align:start position:0% +thermochromic sheets is this curve right + + + align:start position:0% +thermochromic sheets is this curve right +here this is lock-in thermography + + align:start position:0% +here this is lock-in thermography + + + align:start position:0% +here this is lock-in thermography +sensitivity versus integration time and + + align:start position:0% +sensitivity versus integration time and + + + align:start position:0% +sensitivity versus integration time and +we're getting into the 10 micro Kelvin + + align:start position:0% +we're getting into the 10 micro Kelvin + + + align:start position:0% +we're getting into the 10 micro Kelvin +range which is rattlesnake territory all + + align:start position:0% +range which is rattlesnake territory all + + + align:start position:0% +range which is rattlesnake territory all +right that's how the rattlesnakes are + + align:start position:0% +right that's how the rattlesnakes are + + + align:start position:0% +right that's how the rattlesnakes are +able to sense heat and reach out to you + + align:start position:0% +able to sense heat and reach out to you + + + align:start position:0% +able to sense heat and reach out to you +is because they have those little organs + + align:start position:0% +is because they have those little organs + + + align:start position:0% +is because they have those little organs +that look like a little black they're + + align:start position:0% +that look like a little black they're + + + align:start position:0% +that look like a little black they're +kind of like integrating spheres to be + + align:start position:0% +kind of like integrating spheres to be + + + align:start position:0% +kind of like integrating spheres to be +honest small little spot to open up + + align:start position:0% +honest small little spot to open up + + + align:start position:0% +honest small little spot to open up +rattlesnake that's why the Sidewinder + + align:start position:0% +rattlesnake that's why the Sidewinder + + + align:start position:0% +rattlesnake that's why the Sidewinder +missile anybody f-16s Hornets know okay + + align:start position:0% +missile anybody f-16s Hornets know okay + + + align:start position:0% +missile anybody f-16s Hornets know okay +if you're into aviation + + align:start position:0% +if you're into aviation + + + align:start position:0% +if you're into aviation +there's a special type of heat-seeking + + align:start position:0% +there's a special type of heat-seeking + + + align:start position:0% +there's a special type of heat-seeking +missile developed I think in the 1950s + + align:start position:0% +missile developed I think in the 1950s + + + align:start position:0% +missile developed I think in the 1950s +that uses a device not dissimilar from + + align:start position:0% +that uses a device not dissimilar from + + + align:start position:0% +that uses a device not dissimilar from +the rattlesnakes heat sensing organs + + align:start position:0% +the rattlesnakes heat sensing organs + + + align:start position:0% +the rattlesnakes heat sensing organs +regardless I digress we're looking at a + + align:start position:0% +regardless I digress we're looking at a + + + align:start position:0% +regardless I digress we're looking at a +about a 10 micro Kelvin sensitivity in + + align:start position:0% +about a 10 micro Kelvin sensitivity in + + + align:start position:0% +about a 10 micro Kelvin sensitivity in +this lock-in thermography technique + + align:start position:0% +this lock-in thermography technique + + + align:start position:0% +this lock-in thermography technique +which is very sensitive can measure + + align:start position:0% +which is very sensitive can measure + + + align:start position:0% +which is very sensitive can measure +under low forward bias conditions and + + align:start position:0% +under low forward bias conditions and + + + align:start position:0% +under low forward bias conditions and +hence useful okay so that pretty much + + align:start position:0% +hence useful okay so that pretty much + + + align:start position:0% +hence useful okay so that pretty much +sums up lock-in thermography it is a + + align:start position:0% +sums up lock-in thermography it is a + + + align:start position:0% +sums up lock-in thermography it is a +difficult technique to wrap your brain + + align:start position:0% +difficult technique to wrap your brain + + + align:start position:0% +difficult technique to wrap your brain +around right so for those of you who got + + align:start position:0% +around right so for those of you who got + + + align:start position:0% +around right so for those of you who got +75% of it congratulations that was + + align:start position:0% +75% of it congratulations that was + + + align:start position:0% +75% of it congratulations that was +really really well done for those who + + align:start position:0% +really really well done for those who + + + align:start position:0% +really really well done for those who +got about 25 percent of my explanations + + align:start position:0% +got about 25 percent of my explanations + + + align:start position:0% +got about 25 percent of my explanations +today don't worry you're not you're not + + align:start position:0% +today don't worry you're not you're not + + + align:start position:0% +today don't worry you're not you're not +alone it just takes a lot of thinking it + + align:start position:0% +alone it just takes a lot of thinking it + + + align:start position:0% +alone it just takes a lot of thinking it +through exactly okay whereas the current + + align:start position:0% +through exactly okay whereas the current + + + align:start position:0% +through exactly okay whereas the current +flowing as a function bias condition + + align:start position:0% +flowing as a function bias condition + + + align:start position:0% +flowing as a function bias condition +what does that do to my V curve and then + + align:start position:0% +what does that do to my V curve and then + + + align:start position:0% +what does that do to my V curve and then +what is it doing this two dimensional + + align:start position:0% +what is it doing this two dimensional + + + align:start position:0% +what is it doing this two dimensional +regime when i measuring heat output it's + + align:start position:0% +regime when i measuring heat output it's + + + align:start position:0% +regime when i measuring heat output it's +a very complicated thing thankfully + + align:start position:0% +a very complicated thing thankfully + + + align:start position:0% +a very complicated thing thankfully +there is an entire book on lock-in + + align:start position:0% +there is an entire book on lock-in + + + align:start position:0% +there is an entire book on lock-in +thermography written by Othman baikin + + align:start position:0% +thermography written by Othman baikin + + + align:start position:0% +thermography written by Othman baikin +Stein I gave to you today a paper one of + + align:start position:0% +Stein I gave to you today a paper one of + + + align:start position:0% +Stein I gave to you today a paper one of +the papers that I distributed today + + align:start position:0% +the papers that I distributed today + + + align:start position:0% +the papers that I distributed today +the one that has the PSS a written on it + + align:start position:0% +the one that has the PSS a written on it + + + align:start position:0% +the one that has the PSS a written on it +this one that paper is by Othman + + align:start position:0% +this one that paper is by Othman + + + align:start position:0% +this one that paper is by Othman +brightenstein + + align:start position:0% +brightenstein + + + align:start position:0% +brightenstein +from the Max Planck Institute of + + align:start position:0% +from the Max Planck Institute of + + + align:start position:0% +from the Max Planck Institute of +microstructure physics in Halle Germany + + align:start position:0% +microstructure physics in Halle Germany + + + align:start position:0% +microstructure physics in Halle Germany +about two and a half hours south of + + align:start position:0% +about two and a half hours south of + + + align:start position:0% +about two and a half hours south of +Berlin and this describes in more detail + + align:start position:0% +Berlin and this describes in more detail + + + align:start position:0% +Berlin and this describes in more detail +that which I attempted to get across in + + align:start position:0% +that which I attempted to get across in + + + align:start position:0% +that which I attempted to get across in +class today he with Martin Langenkamp + + align:start position:0% +class today he with Martin Langenkamp + + + align:start position:0% +class today he with Martin Langenkamp +have also written the book on lock-in + + align:start position:0% +have also written the book on lock-in + + + align:start position:0% +have also written the book on lock-in +thermography so if you're more + + align:start position:0% +thermography so if you're more + + + align:start position:0% +thermography so if you're more +interested more information that's where + + align:start position:0% +interested more information that's where + + + align:start position:0% +interested more information that's where +to go in your handout set today we also + + align:start position:0% +to go in your handout set today we also + + + align:start position:0% +to go in your handout set today we also +have a classic paper on series + + align:start position:0% +have a classic paper on series + + + align:start position:0% +have a classic paper on series +resistance effects of solar cell + + align:start position:0% +resistance effects of solar cell + + + align:start position:0% +resistance effects of solar cell +measurements this one is from 63 yes + + align:start position:0% +measurements this one is from 63 yes + + + align:start position:0% +measurements this one is from 63 yes +1963 classic paper worth the read if + + align:start position:0% +1963 classic paper worth the read if + + + align:start position:0% +1963 classic paper worth the read if +you're in that regime making devices + + align:start position:0% +you're in that regime making devices + + + align:start position:0% +you're in that regime making devices +that are series is series resistance + + align:start position:0% +that are series is series resistance + + + align:start position:0% +that are series is series resistance +limited it's more optional reading for + + align:start position:0% +limited it's more optional reading for + + + align:start position:0% +limited it's more optional reading for +folks and let's venture forward folks + + align:start position:0% +folks and let's venture forward folks + + + align:start position:0% +folks and let's venture forward folks +who did these scanning albick techniques + + align:start position:0% +who did these scanning albick techniques + + + align:start position:0% +who did these scanning albick techniques +for a while really found value in + + align:start position:0% +for a while really found value in + + + align:start position:0% +for a while really found value in +measuring as a function of spatial + + align:start position:0% +measuring as a function of spatial + + + align:start position:0% +measuring as a function of spatial +spatial resolve manner down to a micron + + align:start position:0% +spatial resolve manner down to a micron + + + align:start position:0% +spatial resolve manner down to a micron +in spatial resolution the electric + + align:start position:0% +in spatial resolution the electric + + + align:start position:0% +in spatial resolution the electric +electrical output of a solar cell device + + align:start position:0% +electrical output of a solar cell device + + + align:start position:0% +electrical output of a solar cell device +and then they thought to themselves well + + align:start position:0% +and then they thought to themselves well + + + align:start position:0% +and then they thought to themselves well +goodness if we measure with one micron + + align:start position:0% +goodness if we measure with one micron + + + align:start position:0% +goodness if we measure with one micron +spot size it's going to take us a week + + align:start position:0% +spot size it's going to take us a week + + + align:start position:0% +spot size it's going to take us a week +to get a measurement across the full + + align:start position:0% +to get a measurement across the full + + + align:start position:0% +to get a measurement across the full +area solar cell device if not longer and + + align:start position:0% +area solar cell device if not longer and + + + align:start position:0% +area solar cell device if not longer and +if we measure say with the 200 nano + + align:start position:0% +if we measure say with the 200 nano + + + align:start position:0% +if we measure say with the 200 nano +meter spot size using some sort of x-ray + + align:start position:0% +meter spot size using some sort of x-ray + + + align:start position:0% +meter spot size using some sort of x-ray +technique and we accumulated for say two + + align:start position:0% +technique and we accumulated for say two + + + align:start position:0% +technique and we accumulated for say two +seconds of point it can take 10,000 + + align:start position:0% +seconds of point it can take 10,000 + + + align:start position:0% +seconds of point it can take 10,000 +years to map out a full sized solar cell + + align:start position:0% +years to map out a full sized solar cell + + + align:start position:0% +years to map out a full sized solar cell +device literally do the math and they + + align:start position:0% +device literally do the math and they + + + align:start position:0% +device literally do the math and they +said is there an easier way for us to + + align:start position:0% +said is there an easier way for us to + + + align:start position:0% +said is there an easier way for us to +acquire information that does not rely + + align:start position:0% +acquire information that does not rely + + + align:start position:0% +acquire information that does not rely +on scanning on point by point step by + + align:start position:0% +on scanning on point by point step by + + + align:start position:0% +on scanning on point by point step by +step measurements and they thought about + + align:start position:0% +step measurements and they thought about + + + align:start position:0% +step measurements and they thought about +it long and hard and they said well gee + + align:start position:0% +it long and hard and they said well gee + + + align:start position:0% +it long and hard and they said well gee +these these new handheld digital cameras + + align:start position:0% +these these new handheld digital cameras + + + align:start position:0% +these these new handheld digital cameras +coming out in the market are pretty cool + + align:start position:0% +coming out in the market are pretty cool + + + align:start position:0% +coming out in the market are pretty cool +what technology do they rely on oh it's + + align:start position:0% +what technology do they rely on oh it's + + + align:start position:0% +what technology do they rely on oh it's +a CCD charge couple display that + + align:start position:0% +a CCD charge couple display that + + + align:start position:0% +a CCD charge couple display that +visualizes our images over a large area + + align:start position:0% +visualizes our images over a large area + + + align:start position:0% +visualizes our images over a large area +the the output of a device and that's + + align:start position:0% +the the output of a device and that's + + + align:start position:0% +the the output of a device and that's +exactly how the lock-in thermography + + align:start position:0% +exactly how the lock-in thermography + + + align:start position:0% +exactly how the lock-in thermography +techniques were developed here with this + + align:start position:0% +techniques were developed here with this + + + align:start position:0% +techniques were developed here with this +this imaging camera in that case an + + align:start position:0% +this imaging camera in that case an + + + align:start position:0% +this imaging camera in that case an +indium antimonide CCD and they said well + + align:start position:0% +indium antimonide CCD and they said well + + + align:start position:0% +indium antimonide CCD and they said well +what other wavelengths admit what in + + align:start position:0% +what other wavelengths admit what in + + + align:start position:0% +what other wavelengths admit what in +what + + align:start position:0% +what + + + align:start position:0% +what +the wavelength does a solar cell emit we + + align:start position:0% +the wavelength does a solar cell emit we + + + align:start position:0% +the wavelength does a solar cell emit we +know that it emits heat right and heat + + align:start position:0% +know that it emits heat right and heat + + + align:start position:0% +know that it emits heat right and heat +is typically in the three to five micron + + align:start position:0% +is typically in the three to five micron + + + align:start position:0% +is typically in the three to five micron +wavelength regime maybe even as high as + + align:start position:0% +wavelength regime maybe even as high as + + + align:start position:0% +wavelength regime maybe even as high as +10 microns depending on what temperature + + align:start position:0% +10 microns depending on what temperature + + + align:start position:0% +10 microns depending on what temperature +and we know that as well we can have + + align:start position:0% +and we know that as well we can have + + + align:start position:0% +and we know that as well we can have +band-to-band emission inside of a solar + + align:start position:0% +band-to-band emission inside of a solar + + + align:start position:0% +band-to-band emission inside of a solar +cell that would emit around the bandgap + + align:start position:0% +cell that would emit around the bandgap + + + align:start position:0% +cell that would emit around the bandgap +energy so let's set up a camera to image + + align:start position:0% +energy so let's set up a camera to image + + + align:start position:0% +energy so let's set up a camera to image +the band to band recombination in + + align:start position:0% +the band to band recombination in + + + align:start position:0% +the band to band recombination in +intensity or the band to band + + align:start position:0% +intensity or the band to band + + + align:start position:0% +intensity or the band to band +illumination intensity and that's what + + align:start position:0% +illumination intensity and that's what + + + align:start position:0% +illumination intensity and that's what +this paper is about + + align:start position:0% + + + + align:start position:0% + +this is wavelength this is intensity + + align:start position:0% +this is wavelength this is intensity + + + align:start position:0% +this is wavelength this is intensity +this is the emission spectrum of a solar + + align:start position:0% +this is the emission spectrum of a solar + + + align:start position:0% +this is the emission spectrum of a solar +cell so if you were to measure what + + align:start position:0% +cell so if you were to measure what + + + align:start position:0% +cell so if you were to measure what +colors what color light does a solar + + align:start position:0% +colors what color light does a solar + + + align:start position:0% +colors what color light does a solar +cell emit after you pump current into it + + align:start position:0% +cell emit after you pump current into it + + + align:start position:0% +cell emit after you pump current into it +this isn't more or less a spectrum so we + + align:start position:0% +this isn't more or less a spectrum so we + + + align:start position:0% +this isn't more or less a spectrum so we +have the the thermal radiation shown + + align:start position:0% +have the the thermal radiation shown + + + align:start position:0% +have the the thermal radiation shown +over here so this is longer wavelength + + align:start position:0% +over here so this is longer wavelength + + + align:start position:0% +over here so this is longer wavelength +light that's the heat that it gives off + + align:start position:0% +light that's the heat that it gives off + + + align:start position:0% +light that's the heat that it gives off +that's what indicates current flow + + align:start position:0% +that's what indicates current flow + + + align:start position:0% +that's what indicates current flow +inside of the device there's the band to + + align:start position:0% +inside of the device there's the band to + + + align:start position:0% +inside of the device there's the band to +band luminescence right here and we'll + + align:start position:0% +band luminescence right here and we'll + + + align:start position:0% +band luminescence right here and we'll +neglect the other two for now those are + + align:start position:0% +neglect the other two for now those are + + + align:start position:0% +neglect the other two for now those are +more advanced constants but the bantha + + align:start position:0% +more advanced constants but the bantha + + + align:start position:0% +more advanced constants but the bantha +band luminescence is essentially just a + + align:start position:0% +band luminescence is essentially just a + + + align:start position:0% +band luminescence is essentially just a +recombination of a carrier from the + + align:start position:0% +recombination of a carrier from the + + + align:start position:0% +recombination of a carrier from the +conduction band to the valence band + + align:start position:0% +conduction band to the valence band + + + align:start position:0% +conduction band to the valence band +right recombination current very + + align:start position:0% +right recombination current very + + + align:start position:0% +right recombination current very +straightforward and the recombination + + align:start position:0% +straightforward and the recombination + + + align:start position:0% +straightforward and the recombination +intensity is inversely proportional to + + align:start position:0% +intensity is inversely proportional to + + + align:start position:0% +intensity is inversely proportional to +the minority carrier lifetime why is + + align:start position:0% +the minority carrier lifetime why is + + + align:start position:0% +the minority carrier lifetime why is +that this was that that quote that I + + align:start position:0% +that this was that that quote that I + + + align:start position:0% +that this was that that quote that I +remember who attended a light one of + + align:start position:0% +remember who attended a light one of + + + align:start position:0% +remember who attended a light one of +itches talk he was saying it's + + align:start position:0% +itches talk he was saying it's + + + align:start position:0% +itches talk he was saying it's +completely counterintuitive + + align:start position:0% +completely counterintuitive + + + align:start position:0% +completely counterintuitive +do you remember specifically what he was + + align:start position:0% +do you remember specifically what he was + + + align:start position:0% +do you remember specifically what he was +referring to in this me show you an + + align:start position:0% +referring to in this me show you an + + + align:start position:0% +referring to in this me show you an +image here hmm + + align:start position:0% + + + + align:start position:0% + +exactly yeah so so why is why what what + + align:start position:0% +exactly yeah so so why is why what what + + + align:start position:0% +exactly yeah so so why is why what what +is going on here we have our towel 1 + + align:start position:0% +is going on here we have our towel 1 + + + align:start position:0% +is going on here we have our towel 1 +over tau effective R 1 over our lifetime + + align:start position:0% +over tau effective R 1 over our lifetime + + + align:start position:0% +over tau effective R 1 over our lifetime +what we're measuring this is our + + align:start position:0% +what we're measuring this is our + + + align:start position:0% +what we're measuring this is our +effective lifetime what we're measuring + + align:start position:0% +effective lifetime what we're measuring + + + align:start position:0% +effective lifetime what we're measuring +and we have 1 over tau let's call it non + + align:start position:0% +and we have 1 over tau let's call it non + + + align:start position:0% +and we have 1 over tau let's call it non +radiative so we have non radiative + + align:start position:0% +radiative so we have non radiative + + + align:start position:0% +radiative so we have non radiative +recombination mechanisms this comprises + + align:start position:0% +recombination mechanisms this comprises + + + align:start position:0% +recombination mechanisms this comprises +shockley-read-hall recombination no J + + align:start position:0% +shockley-read-hall recombination no J + + + align:start position:0% +shockley-read-hall recombination no J +recombination a bunch of different + + align:start position:0% +recombination a bunch of different + + + align:start position:0% +recombination a bunch of different +recombination mechanisms and then we + + align:start position:0% +recombination mechanisms and then we + + + align:start position:0% +recombination mechanisms and then we +have 1 over tau radiative which is + + align:start position:0% +have 1 over tau radiative which is + + + align:start position:0% +have 1 over tau radiative which is +essentially this recombination mechanism + + align:start position:0% +essentially this recombination mechanism + + + align:start position:0% +essentially this recombination mechanism +shown right here which is just the band + + align:start position:0% +shown right here which is just the band + + + align:start position:0% +shown right here which is just the band +to band recombination so if you have + + align:start position:0% +to band recombination so if you have + + + align:start position:0% +to band recombination so if you have +defects around that will lower the + + align:start position:0% +defects around that will lower the + + + align:start position:0% +defects around that will lower the +lifetime the non radiative lifetime if + + align:start position:0% +lifetime the non radiative lifetime if + + + align:start position:0% +lifetime the non radiative lifetime if +you have tons and tons of defects the + + align:start position:0% +you have tons and tons of defects the + + + align:start position:0% +you have tons and tons of defects the +carriers will most likely recombine + + align:start position:0% +carriers will most likely recombine + + + align:start position:0% +carriers will most likely recombine +through the defects and not through the + + align:start position:0% +through the defects and not through the + + + align:start position:0% +through the defects and not through the +bantha band they will only recombine + + align:start position:0% +bantha band they will only recombine + + + align:start position:0% +bantha band they will only recombine +with band to band if there is nothing no + + align:start position:0% +with band to band if there is nothing no + + + align:start position:0% +with band to band if there is nothing no +other recombination path left available + + align:start position:0% +other recombination path left available + + + align:start position:0% +other recombination path left available +to them right it's a question of + + align:start position:0% +to them right it's a question of + + + align:start position:0% +to them right it's a question of +probability so if this is really really + + align:start position:0% +probability so if this is really really + + + align:start position:0% +probability so if this is really really +short non radiative recombination + + align:start position:0% +short non radiative recombination + + + align:start position:0% +short non radiative recombination +lifetime is really really short because + + align:start position:0% +lifetime is really really short because + + + align:start position:0% +lifetime is really really short because +the defect density is very very large so + + align:start position:0% +the defect density is very very large so + + + align:start position:0% +the defect density is very very large so +the lifetime due to non radiative + + align:start position:0% +the lifetime due to non radiative + + + align:start position:0% +the lifetime due to non radiative +recombination mechanisms very short then + + align:start position:0% +recombination mechanisms very short then + + + align:start position:0% +recombination mechanisms very short then +the tau effective is also going to be + + align:start position:0% +the tau effective is also going to be + + + align:start position:0% +the tau effective is also going to be +very short and very few carriers are + + align:start position:0% +very short and very few carriers are + + + align:start position:0% +very short and very few carriers are +going to recombine radiatively + + align:start position:0% +going to recombine radiatively + + + align:start position:0% +going to recombine radiatively +conversely if we have a very clean + + align:start position:0% +conversely if we have a very clean + + + align:start position:0% +conversely if we have a very clean +material virtually defect free this non + + align:start position:0% +material virtually defect free this non + + + align:start position:0% +material virtually defect free this non +radiative lifetime is then going to be + + align:start position:0% +radiative lifetime is then going to be + + + align:start position:0% +radiative lifetime is then going to be +out the roof and now we're going to be + + align:start position:0% +out the roof and now we're going to be + + + align:start position:0% +out the roof and now we're going to be +limited instead by the radiative + + align:start position:0% +limited instead by the radiative + + + align:start position:0% +limited instead by the radiative +lifetime and so tau effective will be + + align:start position:0% +lifetime and so tau effective will be + + + align:start position:0% +lifetime and so tau effective will be +more similar to rate is it now an + + align:start position:0% +more similar to rate is it now an + + + align:start position:0% +more similar to rate is it now an +interesting thing happens when you have + + align:start position:0% +interesting thing happens when you have + + + align:start position:0% +interesting thing happens when you have +a radiative recombination event as the + + align:start position:0% +a radiative recombination event as the + + + align:start position:0% +a radiative recombination event as the +name would suggest it emits light and + + align:start position:0% +name would suggest it emits light and + + + align:start position:0% +name would suggest it emits light and +that light can be detected by a CCD + + align:start position:0% +that light can be detected by a CCD + + + align:start position:0% +that light can be detected by a CCD +camera nearby so what you Boopsie what + + align:start position:0% +camera nearby so what you Boopsie what + + + align:start position:0% +camera nearby so what you Boopsie what +you have we go what you have right here + + align:start position:0% +you have we go what you have right here + + + align:start position:0% +you have we go what you have right here +is a solar cell device that is being + + align:start position:0% +is a solar cell device that is being + + + align:start position:0% +is a solar cell device that is being +biased so current is flowing into the + + align:start position:0% +biased so current is flowing into the + + + align:start position:0% +biased so current is flowing into the +device and now the the map what you're + + align:start position:0% +device and now the the map what you're + + + align:start position:0% +device and now the the map what you're +seeing is indicative of radiative + + align:start position:0% +seeing is indicative of radiative + + + align:start position:0% +seeing is indicative of radiative +recombination why because nearby the + + align:start position:0% +recombination why because nearby the + + + align:start position:0% +recombination why because nearby the +cell it's essentially very similar + + align:start position:0% +cell it's essentially very similar + + + align:start position:0% +cell it's essentially very similar +mechanism or similar setup to what we + + align:start position:0% +mechanism or similar setup to what we + + + align:start position:0% +mechanism or similar setup to what we +saw right here where we had bias voltage + + align:start position:0% +saw right here where we had bias voltage + + + align:start position:0% +saw right here where we had bias voltage +across the + + align:start position:0% +across the + + + align:start position:0% +across the +and imaging not with an infrared camera + + align:start position:0% +and imaging not with an infrared camera + + + align:start position:0% +and imaging not with an infrared camera +but now with a camera matched to the + + align:start position:0% +but now with a camera matched to the + + + align:start position:0% +but now with a camera matched to the +bandgap energy this could be in indium + + align:start position:0% +bandgap energy this could be in indium + + + align:start position:0% +bandgap energy this could be in indium +gallium arsenide camera or say a silicon + + align:start position:0% +gallium arsenide camera or say a silicon + + + align:start position:0% +gallium arsenide camera or say a silicon +camera depending on the precise bang gap + + align:start position:0% +camera depending on the precise bang gap + + + align:start position:0% +camera depending on the precise bang gap +and your imaging the radiative + + align:start position:0% +and your imaging the radiative + + + align:start position:0% +and your imaging the radiative +recombination as a function of XY + + align:start position:0% +recombination as a function of XY + + + align:start position:0% +recombination as a function of XY +position across your wafer so these + + align:start position:0% +position across your wafer so these + + + align:start position:0% +position across your wafer so these +darker regions here on the bottom and on + + align:start position:0% +darker regions here on the bottom and on + + + align:start position:0% +darker regions here on the bottom and on +the right sorry left the other right + + align:start position:0% +the right sorry left the other right + + + align:start position:0% +the right sorry left the other right +they indicate regions of lower minority + + align:start position:0% +they indicate regions of lower minority + + + align:start position:0% +they indicate regions of lower minority +carrier diffusion length why because + + align:start position:0% +carrier diffusion length why because + + + align:start position:0% +carrier diffusion length why because +there's less radiative recombination + + align:start position:0% +there's less radiative recombination + + + align:start position:0% +there's less radiative recombination +because this term in those regions is + + align:start position:0% +because this term in those regions is + + + align:start position:0% +because this term in those regions is +very very small so that there's not much + + align:start position:0% +very very small so that there's not much + + + align:start position:0% +very very small so that there's not much +radiative recombination going on whereas + + align:start position:0% +radiative recombination going on whereas + + + align:start position:0% +radiative recombination going on whereas +these other regions here that if you're + + align:start position:0% +these other regions here that if you're + + + align:start position:0% +these other regions here that if you're +brighter have a lot more radiative + + align:start position:0% +brighter have a lot more radiative + + + align:start position:0% +brighter have a lot more radiative +recombination going on any questions + + align:start position:0% +recombination going on any questions + + + align:start position:0% +recombination going on any questions +about that yeah + + align:start position:0% + + + + align:start position:0% + +getting hot days + + align:start position:0% +getting hot days + + + align:start position:0% +getting hot days +sure so the question pertains to photon + + align:start position:0% +sure so the question pertains to photon + + + align:start position:0% +sure so the question pertains to photon +recycling and how many photons that are + + align:start position:0% +recycling and how many photons that are + + + align:start position:0% +recycling and how many photons that are +radiatively emitted get reabsorbed by + + align:start position:0% +radiatively emitted get reabsorbed by + + + align:start position:0% +radiatively emitted get reabsorbed by +the material that would depend on the + + align:start position:0% +the material that would depend on the + + + align:start position:0% +the material that would depend on the +optical path length inside of the + + align:start position:0% +optical path length inside of the + + + align:start position:0% +optical path length inside of the +material of carriers being generated in + + align:start position:0% +material of carriers being generated in + + + align:start position:0% +material of carriers being generated in +the material and you can assume that + + align:start position:0% +the material and you can assume that + + + align:start position:0% +the material and you can assume that +carrier generation is fairly isotropic + + align:start position:0% +carrier generation is fairly isotropic + + + align:start position:0% +carrier generation is fairly isotropic +in nature that there's not any preferred + + align:start position:0% +in nature that there's not any preferred + + + align:start position:0% +in nature that there's not any preferred +direction unless you have a dye molecule + + align:start position:0% +direction unless you have a dye molecule + + + align:start position:0% +direction unless you have a dye molecule +that's designed in a certain way to emit + + align:start position:0% +that's designed in a certain way to emit + + + align:start position:0% +that's designed in a certain way to emit +light in a certain orientation so you + + align:start position:0% +light in a certain orientation so you + + + align:start position:0% +light in a certain orientation so you +can assume that the carrier mission in + + align:start position:0% +can assume that the carrier mission in + + + align:start position:0% +can assume that the carrier mission in +most materials is isotropic in nature + + align:start position:0% +most materials is isotropic in nature + + + align:start position:0% +most materials is isotropic in nature +and then it's just a question of ray + + align:start position:0% +and then it's just a question of ray + + + align:start position:0% +and then it's just a question of ray +tracing to figure out what the optical + + align:start position:0% +tracing to figure out what the optical + + + align:start position:0% +tracing to figure out what the optical +path length is compare that to the + + align:start position:0% +path length is compare that to the + + + align:start position:0% +path length is compare that to the +optical absorption coefficients in the + + align:start position:0% +optical absorption coefficients in the + + + align:start position:0% +optical absorption coefficients in the +material and you'll get your answer what + + align:start position:0% +material and you'll get your answer what + + + align:start position:0% +material and you'll get your answer what +fraction of light gets reabsorbed all + + align:start position:0% +fraction of light gets reabsorbed all + + + align:start position:0% +fraction of light gets reabsorbed all +right + + align:start position:0% +right + + + align:start position:0% +right +I can sense where we're reaching + + align:start position:0% +I can sense where we're reaching + + + align:start position:0% +I can sense where we're reaching +threshold here in terms of new + + align:start position:0% +threshold here in terms of new + + + align:start position:0% +threshold here in terms of new +information gathered I'm just going to + + align:start position:0% +information gathered I'm just going to + + + align:start position:0% +information gathered I'm just going to +briefly go over the sun's vo see at the + + align:start position:0% +briefly go over the sun's vo see at the + + + align:start position:0% +briefly go over the sun's vo see at the +very end and the sun's vo see technique + + align:start position:0% +very end and the sun's vo see technique + + + align:start position:0% +very end and the sun's vo see technique +is useful as we saw during class because + + align:start position:0% +is useful as we saw during class because + + + align:start position:0% +is useful as we saw during class because +as this paper right here by Ron Sinton + + align:start position:0% +as this paper right here by Ron Sinton + + + align:start position:0% +as this paper right here by Ron Sinton +and dice Cuevas this one I know you + + align:start position:0% +and dice Cuevas this one I know you + + + align:start position:0% +and dice Cuevas this one I know you +definitely have this one this paper + + align:start position:0% +definitely have this one this paper + + + align:start position:0% +definitely have this one this paper +essentially describes the functioning of + + align:start position:0% +essentially describes the functioning of + + + align:start position:0% +essentially describes the functioning of +the technique on page number two on the + + align:start position:0% +the technique on page number two on the + + + align:start position:0% +the technique on page number two on the +upper left-hand side so figure two we + + align:start position:0% +upper left-hand side so figure two we + + + align:start position:0% +upper left-hand side so figure two we +essentially have the figure that was + + align:start position:0% +essentially have the figure that was + + + align:start position:0% +essentially have the figure that was +determined on the screen during the + + align:start position:0% +determined on the screen during the + + + align:start position:0% +determined on the screen during the +measurements so for those of you are + + align:start position:0% +measurements so for those of you are + + + align:start position:0% +measurements so for those of you are +close enough to the mana to actually + + align:start position:0% +close enough to the mana to actually + + + align:start position:0% +close enough to the mana to actually +watch the the measurement being taken + + align:start position:0% +watch the the measurement being taken + + + align:start position:0% +watch the the measurement being taken +the sun's BOC you saw the light + + align:start position:0% +the sun's BOC you saw the light + + + align:start position:0% +the sun's BOC you saw the light +intensity decaying exponentially right + + align:start position:0% +intensity decaying exponentially right + + + align:start position:0% +intensity decaying exponentially right +so the light intensity was a flash ball + + align:start position:0% +so the light intensity was a flash ball + + + align:start position:0% +so the light intensity was a flash ball +poof and decay exponentially the open + + align:start position:0% +poof and decay exponentially the open + + + align:start position:0% +poof and decay exponentially the open +circuit voltage measured by the device + + align:start position:0% +circuit voltage measured by the device + + + align:start position:0% +circuit voltage measured by the device +so you had this solar cell device + + align:start position:0% +so you had this solar cell device + + + align:start position:0% +so you had this solar cell device +sitting on the platen with a little + + align:start position:0% +sitting on the platen with a little + + + align:start position:0% +sitting on the platen with a little +probe coming in and a 50 mega ohm + + align:start position:0% +probe coming in and a 50 mega ohm + + + align:start position:0% +probe coming in and a 50 mega ohm +resistor connected in series very little + + align:start position:0% +resistor connected in series very little + + + align:start position:0% +resistor connected in series very little +current flowing through that external + + align:start position:0% +current flowing through that external + + + align:start position:0% +current flowing through that external +circuit right but it's measuring the + + align:start position:0% +circuit right but it's measuring the + + + align:start position:0% +circuit right but it's measuring the +voltage so it's essentially maintaining + + align:start position:0% +voltage so it's essentially maintaining + + + align:start position:0% +voltage so it's essentially maintaining +the solar cell in open circuit voltage + + align:start position:0% +the solar cell in open circuit voltage + + + align:start position:0% +the solar cell in open circuit voltage +conditions while the flash is decaying + + align:start position:0% +conditions while the flash is decaying + + + align:start position:0% +conditions while the flash is decaying +and it's measuring the open circuit + + align:start position:0% +and it's measuring the open circuit + + + align:start position:0% +and it's measuring the open circuit +voltage across that device at each + + align:start position:0% +voltage across that device at each + + + align:start position:0% +voltage across that device at each +illumination intensity as the pulse + + align:start position:0% +illumination intensity as the pulse + + + align:start position:0% +illumination intensity as the pulse +decays so you can see the timescale here + + align:start position:0% +decays so you can see the timescale here + + + align:start position:0% +decays so you can see the timescale here +as an eye order of a few tens of + + align:start position:0% +as an eye order of a few tens of + + + align:start position:0% +as an eye order of a few tens of +Ekans so very fast measurement the + + align:start position:0% +Ekans so very fast measurement the + + + align:start position:0% +Ekans so very fast measurement the +electronics response time has to be very + + align:start position:0% +electronics response time has to be very + + + align:start position:0% +electronics response time has to be very +fast that tells you what the RC time + + align:start position:0% +fast that tells you what the RC time + + + align:start position:0% +fast that tells you what the RC time +constant of the circuit is and the you + + align:start position:0% +constant of the circuit is and the you + + + align:start position:0% +constant of the circuit is and the you +can notice that the voltage the open + + align:start position:0% +can notice that the voltage the open + + + align:start position:0% +can notice that the voltage the open +circuit voltage decays linearly when the + + align:start position:0% +circuit voltage decays linearly when the + + + align:start position:0% +circuit voltage decays linearly when the +illumination intensity decays + + align:start position:0% +illumination intensity decays + + + align:start position:0% +illumination intensity decays +exponentially why is that there's a + + align:start position:0% +exponentially why is that there's a + + + align:start position:0% +exponentially why is that there's a +natural log yes this is what we what Joe + + align:start position:0% +natural log yes this is what we what Joe + + + align:start position:0% +natural log yes this is what we what Joe +showed to you yesterday or on Thursday + + align:start position:0% +showed to you yesterday or on Thursday + + + align:start position:0% +showed to you yesterday or on Thursday +in class is how the voltage output of a + + align:start position:0% +in class is how the voltage output of a + + + align:start position:0% +in class is how the voltage output of a +solar cell varies by illumination + + align:start position:0% +solar cell varies by illumination + + + align:start position:0% +solar cell varies by illumination +intensity so there's a logarithmic + + align:start position:0% +intensity so there's a logarithmic + + + align:start position:0% +intensity so there's a logarithmic +dependence there so that's why you take + + align:start position:0% +dependence there so that's why you take + + + align:start position:0% +dependence there so that's why you take +the log of the exponentially decaying + + align:start position:0% +the log of the exponentially decaying + + + align:start position:0% +the log of the exponentially decaying +light intensity and you obtain a linear + + align:start position:0% +light intensity and you obtain a linear + + + align:start position:0% +light intensity and you obtain a linear +relation that's the open circuit voltage + + align:start position:0% +relation that's the open circuit voltage + + + align:start position:0% +relation that's the open circuit voltage +decline as a function of time okay so we + + align:start position:0% +decline as a function of time okay so we + + + align:start position:0% +decline as a function of time okay so we +can derive an IV characteristic by + + align:start position:0% +can derive an IV characteristic by + + + align:start position:0% +can derive an IV characteristic by +translating that open circuit voltage + + align:start position:0% +translating that open circuit voltage + + + align:start position:0% +translating that open circuit voltage +into an implied bias voltage and knowing + + align:start position:0% +into an implied bias voltage and knowing + + + align:start position:0% +into an implied bias voltage and knowing +the short-circuit current density up + + align:start position:0% +the short-circuit current density up + + + align:start position:0% +the short-circuit current density up +front essentially by measuring it using + + align:start position:0% +front essentially by measuring it using + + + align:start position:0% +front essentially by measuring it using +an a by measuring the solar cell device + + align:start position:0% +an a by measuring the solar cell device + + + align:start position:0% +an a by measuring the solar cell device +in a solar simulator we can obtain the + + align:start position:0% +in a solar simulator we can obtain the + + + align:start position:0% +in a solar simulator we can obtain the +short-circuit current density we pin + + align:start position:0% +short-circuit current density we pin + + + align:start position:0% +short-circuit current density we pin +both curves up here at the measured + + align:start position:0% +both curves up here at the measured + + + align:start position:0% +both curves up here at the measured +short-circuit current density and then + + align:start position:0% +short-circuit current density and then + + + align:start position:0% +short-circuit current density and then +we plot both curves out the IV curve and + + align:start position:0% +we plot both curves out the IV curve and + + + align:start position:0% +we plot both curves out the IV curve and +the sun's v OC curve now the sun's V OC + + align:start position:0% +the sun's v OC curve now the sun's V OC + + + align:start position:0% +the sun's v OC curve now the sun's V OC +curve is Union is similar to the IV + + align:start position:0% +curve is Union is similar to the IV + + + align:start position:0% +curve is Union is similar to the IV +curve with only one difference there's + + align:start position:0% +curve with only one difference there's + + + align:start position:0% +curve with only one difference there's +no current or very very little current + + align:start position:0% +no current or very very little current + + + align:start position:0% +no current or very very little current +flowing through the external circuit + + align:start position:0% +flowing through the external circuit + + + align:start position:0% +flowing through the external circuit +which means there isn't any real power + + align:start position:0% +which means there isn't any real power + + + align:start position:0% +which means there isn't any real power +flowing through the external circuit + + align:start position:0% +flowing through the external circuit + + + align:start position:0% +flowing through the external circuit +which means if we go back to our + + align:start position:0% +which means if we go back to our + + + align:start position:0% +which means if we go back to our +expression right here if we have no + + align:start position:0% +expression right here if we have no + + + align:start position:0% +expression right here if we have no +current flowing through that J is equal + + align:start position:0% +current flowing through that J is equal + + + align:start position:0% +current flowing through that J is equal +to zero and now that R sub s term + + align:start position:0% +to zero and now that R sub s term + + + align:start position:0% +to zero and now that R sub s term +disappears so we've come up with a + + align:start position:0% +disappears so we've come up with a + + + align:start position:0% +disappears so we've come up with a +clever way to drop all of our R sub + + align:start position:0% +clever way to drop all of our R sub + + + align:start position:0% +clever way to drop all of our R sub +asses out of that expression and the + + align:start position:0% +asses out of that expression and the + + + align:start position:0% +asses out of that expression and the +only thing that matters essentially is + + align:start position:0% +only thing that matters essentially is + + + align:start position:0% +only thing that matters essentially is +is well some degree shunt but this is + + align:start position:0% +is well some degree shunt but this is + + + align:start position:0% +is well some degree shunt but this is +essentially the highest IV curve that + + align:start position:0% +essentially the highest IV curve that + + + align:start position:0% +essentially the highest IV curve that +one could possibly obtain in the absence + + align:start position:0% +one could possibly obtain in the absence + + + align:start position:0% +one could possibly obtain in the absence +of series resistance and that's what you + + align:start position:0% +of series resistance and that's what you + + + align:start position:0% +of series resistance and that's what you +see right here that's this Delta in + + align:start position:0% +see right here that's this Delta in + + + align:start position:0% +see right here that's this Delta in +between your illuminated IV curve what + + align:start position:0% +between your illuminated IV curve what + + + align:start position:0% +between your illuminated IV curve what +is measured using the solar simulator + + align:start position:0% +is measured using the solar simulator + + + align:start position:0% +is measured using the solar simulator +and your son's V OC curve which is + + align:start position:0% +and your son's V OC curve which is + + + align:start position:0% +and your son's V OC curve which is +measured in the absence of series + + align:start position:0% +measured in the absence of series + + + align:start position:0% +measured in the absence of series +now this works well with most materials + + align:start position:0% +now this works well with most materials + + + align:start position:0% +now this works well with most materials +if you have a very high capacitance in + + align:start position:0% +if you have a very high capacitance in + + + align:start position:0% +if you have a very high capacitance in +your device you'll want to look very + + align:start position:0% +your device you'll want to look very + + + align:start position:0% +your device you'll want to look very +carefully at this at this decay right at + + align:start position:0% +carefully at this at this decay right at + + + align:start position:0% +carefully at this at this decay right at +the light intensity decay if your + + align:start position:0% +the light intensity decay if your + + + align:start position:0% +the light intensity decay if your +capacitance in your device is very large + + align:start position:0% +capacitance in your device is very large + + + align:start position:0% +capacitance in your device is very large +it might actually flatten out the + + align:start position:0% +it might actually flatten out the + + + align:start position:0% +it might actually flatten out the +voltage response so you want to make + + align:start position:0% +voltage response so you want to make + + + align:start position:0% +voltage response so you want to make +sure that the time RC time constant of + + align:start position:0% +sure that the time RC time constant of + + + align:start position:0% +sure that the time RC time constant of +your devices is matched to the the + + align:start position:0% +your devices is matched to the the + + + align:start position:0% +your devices is matched to the the +flashbulb decay time that's just one + + align:start position:0% +flashbulb decay time that's just one + + + align:start position:0% +flashbulb decay time that's just one +word of warning for those working on + + align:start position:0% +word of warning for those working on + + + align:start position:0% +word of warning for those working on +high-voltage or organic materials any + + align:start position:0% +high-voltage or organic materials any + + + align:start position:0% +high-voltage or organic materials any +questions on the Sun vo C measurement + + align:start position:0% +questions on the Sun vo C measurement + + + align:start position:0% +questions on the Sun vo C measurement +this is gives you what's called an + + align:start position:0% +this is gives you what's called an + + + align:start position:0% +this is gives you what's called an +implied IV curve and that is as a would + + align:start position:0% +implied IV curve and that is as a would + + + align:start position:0% +implied IV curve and that is as a would +say in in the best case scenario what + + align:start position:0% +say in in the best case scenario what + + + align:start position:0% +say in in the best case scenario what +you would get from the solar cell in the + + align:start position:0% +you would get from the solar cell in the + + + align:start position:0% +you would get from the solar cell in the +absence of any series resistance losses + + align:start position:0% + + + + align:start position:0% + +No + + align:start position:0% + + + + align:start position:0% + +yeah it is important it would be a + + align:start position:0% +yeah it is important it would be a + + + align:start position:0% +yeah it is important it would be a +different in essence it would be a + + align:start position:0% +different in essence it would be a + + + align:start position:0% +different in essence it would be a +different current response right if you + + align:start position:0% +different current response right if you + + + align:start position:0% +different current response right if you +didn't have the same exact solar + + align:start position:0% +didn't have the same exact solar + + + align:start position:0% +didn't have the same exact solar +spectrum now that's a very important + + align:start position:0% +spectrum now that's a very important + + + align:start position:0% +spectrum now that's a very important +point if you're venturing outside of say + + align:start position:0% +point if you're venturing outside of say + + + align:start position:0% +point if you're venturing outside of say +silicon based devices and you're more + + align:start position:0% +silicon based devices and you're more + + + align:start position:0% +silicon based devices and you're more +sensitive to the infrared or the UV you + + align:start position:0% +sensitive to the infrared or the UV you + + + align:start position:0% +sensitive to the infrared or the UV you +really want to make sure that you + + align:start position:0% +really want to make sure that you + + + align:start position:0% +really want to make sure that you +measure the intensity as a function of + + align:start position:0% +measure the intensity as a function of + + + align:start position:0% +measure the intensity as a function of +wavelength output of that bulb otherwise + + align:start position:0% +wavelength output of that bulb otherwise + + + align:start position:0% +wavelength output of that bulb otherwise +your you might be higher or lower + + align:start position:0% +your you might be higher or lower + + + align:start position:0% +your you might be higher or lower +during the sun's boc measurement for a + + align:start position:0% +during the sun's boc measurement for a + + + align:start position:0% +during the sun's boc measurement for a +silicon-based device majority falls + + align:start position:0% +silicon-based device majority falls + + + align:start position:0% +silicon-based device majority falls +within the specified regime down here + + align:start position:0% +within the specified regime down here + + + align:start position:0% +within the specified regime down here +actually right here sorry on this + + align:start position:0% +actually right here sorry on this + + + align:start position:0% +actually right here sorry on this +diagram that little spot right there + + align:start position:0% +diagram that little spot right there + + + align:start position:0% +diagram that little spot right there +that is a small calibration solar cell + + align:start position:0% +that is a small calibration solar cell + + + align:start position:0% +that is a small calibration solar cell +of known short-circuit current an open + + align:start position:0% +of known short-circuit current an open + + + align:start position:0% +of known short-circuit current an open +circuit voltage so that's used to + + align:start position:0% +circuit voltage so that's used to + + + align:start position:0% +circuit voltage so that's used to +calibrate for other silicon devices if + + align:start position:0% +calibrate for other silicon devices if + + + align:start position:0% +calibrate for other silicon devices if +you're moving away from silicon that + + align:start position:0% +you're moving away from silicon that + + + align:start position:0% +you're moving away from silicon that +becomes an issue + + align:start position:0% + + + + align:start position:0% + +correctible you can measure the spectral + + align:start position:0% +correctible you can measure the spectral + + + align:start position:0% +correctible you can measure the spectral +response of that light source and + + align:start position:0% +response of that light source and + + + align:start position:0% +response of that light source and +compare it to the solar simulator and do + + align:start position:0% +compare it to the solar simulator and do + + + align:start position:0% +compare it to the solar simulator and do +the normalization accordingly here's + + align:start position:0% +the normalization accordingly here's + + + align:start position:0% +the normalization accordingly here's +what I recommend + + align:start position:0% +what I recommend + + + align:start position:0% +what I recommend +with the last 15 minutes of class I + + align:start position:0% +with the last 15 minutes of class I + + + align:start position:0% +with the last 15 minutes of class I +wanted to catch each of the teams and + + align:start position:0% +wanted to catch each of the teams and + + + align:start position:0% +wanted to catch each of the teams and +talk about your class projects to make + + align:start position:0% +talk about your class projects to make + + + align:start position:0% +talk about your class projects to make +sure that things were rolling along + + align:start position:0% +sure that things were rolling along + + + align:start position:0% +sure that things were rolling along +I have feelers out to some of the + + align:start position:0% +I have feelers out to some of the + + + align:start position:0% +I have feelers out to some of the +mentors who haven't responded yet and so + + align:start position:0% +mentors who haven't responded yet and so + + + align:start position:0% +mentors who haven't responded yet and so +I just wanted to touch base with each of + + align:start position:0% +I just wanted to touch base with each of + + + align:start position:0% +I just wanted to touch base with each of +you for about three minutes just to make + + align:start position:0% +you for about three minutes just to make + + + align:start position:0% +you for about three minutes just to make +sure everything is rolling along + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/yjBerM5jWsc.txt b/yjBerM5jWsc.txt new file mode 100644 index 0000000000000000000000000000000000000000..39fd874f0a32cf01d048e9f7440425bf778e4dbd --- /dev/null +++ b/yjBerM5jWsc.txt @@ -0,0 +1,7603 @@ +align:start position:0% + +Okay, this is linear algebra lecture + + align:start position:0% +Okay, this is linear algebra lecture + + + align:start position:0% +Okay, this is linear algebra lecture +nine and this is a key lecture. This is + + align:start position:0% +nine and this is a key lecture. This is + + + align:start position:0% +nine and this is a key lecture. This is +where we get these ideas of + + align:start position:0% +where we get these ideas of + + + align:start position:0% +where we get these ideas of +linear independence. When a bunch of + + align:start position:0% +linear independence. When a bunch of + + + align:start position:0% +linear independence. When a bunch of +vectors are independent + + align:start position:0% +vectors are independent + + + align:start position:0% +vectors are independent +or dependent, that's the opposite. + + align:start position:0% +or dependent, that's the opposite. + + + align:start position:0% +or dependent, that's the opposite. +Uh the space they span, + + align:start position:0% +Uh the space they span, + + + align:start position:0% +Uh the space they span, +a basis for a subspace or a basis for a + + align:start position:0% +a basis for a subspace or a basis for a + + + align:start position:0% +a basis for a subspace or a basis for a +vector space, that's a central idea. And + + align:start position:0% +vector space, that's a central idea. And + + + align:start position:0% +vector space, that's a central idea. And +then the dimension of that subspace. So + + align:start position:0% +then the dimension of that subspace. So + + + align:start position:0% +then the dimension of that subspace. So +this is the day that those words get + + align:start position:0% +this is the day that those words get + + + align:start position:0% +this is the day that those words get +assigned clear meanings and emphasize + + align:start position:0% +assigned clear meanings and emphasize + + + align:start position:0% +assigned clear meanings and emphasize +that we talk about + + align:start position:0% +that we talk about + + + align:start position:0% +that we talk about +a bunch of vectors being independent. + + align:start position:0% +a bunch of vectors being independent. + + + align:start position:0% +a bunch of vectors being independent. +Wouldn't talk about a matrix being + + align:start position:0% +Wouldn't talk about a matrix being + + + align:start position:0% +Wouldn't talk about a matrix being +independent, a bunch of vectors being + + align:start position:0% +independent, a bunch of vectors being + + + align:start position:0% +independent, a bunch of vectors being +independent, a bunch of vectors spanning + + align:start position:0% +independent, a bunch of vectors spanning + + + align:start position:0% +independent, a bunch of vectors spanning +a space, a bunch of vectors being a + + align:start position:0% +a space, a bunch of vectors being a + + + align:start position:0% +a space, a bunch of vectors being a +basis, and the dimension is some number. + + align:start position:0% +basis, and the dimension is some number. + + + align:start position:0% +basis, and the dimension is some number. +Okay. So what are the definitions? Can I + + align:start position:0% +Okay. So what are the definitions? Can I + + + align:start position:0% +Okay. So what are the definitions? Can I +begin with a fact a highly important + + align:start position:0% +begin with a fact a highly important + + + align:start position:0% +begin with a fact a highly important +fact that uh I didn't call directly + + align:start position:0% +fact that uh I didn't call directly + + + align:start position:0% +fact that uh I didn't call directly +attention to earlier. Suppose I have a + + align:start position:0% +attention to earlier. Suppose I have a + + + align:start position:0% +attention to earlier. Suppose I have a +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +and I look at ax equals z. + + align:start position:0% +and I look at ax equals z. + + + align:start position:0% +and I look at ax equals z. +Suppose the matrix has a lot of columns + + align:start position:0% +Suppose the matrix has a lot of columns + + + align:start position:0% +Suppose the matrix has a lot of columns +so that n is bigger than m. So, I'm + + align:start position:0% +so that n is bigger than m. So, I'm + + + align:start position:0% +so that n is bigger than m. So, I'm +looking at n equations. I'm sorry, m + + align:start position:0% +looking at n equations. I'm sorry, m + + + align:start position:0% +looking at n equations. I'm sorry, m +equations. A small number of equations, + + align:start position:0% +equations. A small number of equations, + + + align:start position:0% +equations. A small number of equations, +m and more unknowns. I have more + + align:start position:0% +m and more unknowns. I have more + + + align:start position:0% +m and more unknowns. I have more +unknowns than equations. + + align:start position:0% +unknowns than equations. + + + align:start position:0% +unknowns than equations. +Let me write that down. More unknowns + + align:start position:0% +Let me write that down. More unknowns + + + align:start position:0% +Let me write that down. More unknowns +than equations. + + align:start position:0% +than equations. + + + align:start position:0% +than equations. +More + + align:start position:0% +More + + + align:start position:0% +More +unknown x's + + align:start position:0% + + + + align:start position:0% + +than equations. + + align:start position:0% + + + + align:start position:0% + +Then + + align:start position:0% +Then + + + align:start position:0% +Then +then the conclusion is that there's + + align:start position:0% +then the conclusion is that there's + + + align:start position:0% +then the conclusion is that there's +something in the null space of a + + align:start position:0% +something in the null space of a + + + align:start position:0% +something in the null space of a +other than just the zero vector. The + + align:start position:0% +other than just the zero vector. The + + + align:start position:0% +other than just the zero vector. The +conclusion is there are some nonzero + + align:start position:0% +conclusion is there are some nonzero + + + align:start position:0% +conclusion is there are some nonzero +x's such that ax is zero. There are some + + align:start position:0% +x's such that ax is zero. There are some + + + align:start position:0% +x's such that ax is zero. There are some +special solutions and why we know why. + + align:start position:0% +special solutions and why we know why. + + + align:start position:0% +special solutions and why we know why. +I mean it sort of like seems like a + + align:start position:0% +I mean it sort of like seems like a + + + align:start position:0% +I mean it sort of like seems like a +reasonable thing. more unknowns than + + align:start position:0% +reasonable thing. more unknowns than + + + align:start position:0% +reasonable thing. more unknowns than +equations + + align:start position:0% +equations + + + align:start position:0% +equations +then it seems reasonable that we can + + align:start position:0% +then it seems reasonable that we can + + + align:start position:0% +then it seems reasonable that we can +solve them. But we have a a clear + + align:start position:0% +solve them. But we have a a clear + + + align:start position:0% +solve them. But we have a a clear +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +which starts with a system and does + + align:start position:0% +which starts with a system and does + + + align:start position:0% +which starts with a system and does +elimination + + align:start position:0% +elimination + + + align:start position:0% +elimination +gets the thing into an echelon form with + + align:start position:0% +gets the thing into an echelon form with + + + align:start position:0% +gets the thing into an echelon form with +some pivots and pivot columns + + align:start position:0% +some pivots and pivot columns + + + align:start position:0% +some pivots and pivot columns +and possibly some free columns that + + align:start position:0% +and possibly some free columns that + + + align:start position:0% +and possibly some free columns that +don't have pivots. And the point is here + + align:start position:0% +don't have pivots. And the point is here + + + align:start position:0% +don't have pivots. And the point is here +there will be some free columns. The + + align:start position:0% +there will be some free columns. The + + + align:start position:0% +there will be some free columns. The +reason so the reason is + + align:start position:0% +reason so the reason is + + + align:start position:0% +reason so the reason is +there must there will be + + align:start position:0% +there must there will be + + + align:start position:0% +there must there will be +free variables at least one. + + align:start position:0% + + + + align:start position:0% + +That's the reason + + align:start position:0% +That's the reason + + + align:start position:0% +That's the reason +that we we now have this a complete uh + + align:start position:0% +that we we now have this a complete uh + + + align:start position:0% +that we we now have this a complete uh +algorithm complete systematic way to say + + align:start position:0% +algorithm complete systematic way to say + + + align:start position:0% +algorithm complete systematic way to say +okay we take the system ax equals zero + + align:start position:0% +okay we take the system ax equals zero + + + align:start position:0% +okay we take the system ax equals zero +we row reduce we identify the free + + align:start position:0% +we row reduce we identify the free + + + align:start position:0% +we row reduce we identify the free +variables and since there are n + + align:start position:0% +variables and since there are n + + + align:start position:0% +variables and since there are n +variables + + align:start position:0% +variables + + + align:start position:0% +variables +and at most m pivots there will be some + + align:start position:0% +and at most m pivots there will be some + + + align:start position:0% +and at most m pivots there will be some +free variables at least one at least n + + align:start position:0% +free variables at least one at least n + + + align:start position:0% +free variables at least one at least n +minus m in fact left over and those + + align:start position:0% +minus m in fact left over and those + + + align:start position:0% +minus m in fact left over and those +variables I can assign nonzero values + + align:start position:0% +variables I can assign nonzero values + + + align:start position:0% +variables I can assign nonzero values +to. I don't have to set those to zero. I + + align:start position:0% +to. I don't have to set those to zero. I + + + align:start position:0% +to. I don't have to set those to zero. I +can take them to be one or whatever I + + align:start position:0% +can take them to be one or whatever I + + + align:start position:0% +can take them to be one or whatever I +like and then I can solve for the pivot + + align:start position:0% +like and then I can solve for the pivot + + + align:start position:0% +like and then I can solve for the pivot +variables. So then it gives me a + + align:start position:0% +variables. So then it gives me a + + + align:start position:0% +variables. So then it gives me a +solution to ax equals z and it's a + + align:start position:0% +solution to ax equals z and it's a + + + align:start position:0% +solution to ax equals z and it's a +solution that isn't all zeros. + + align:start position:0% +solution that isn't all zeros. + + + align:start position:0% +solution that isn't all zeros. +So uh that's a c that's a important + + align:start position:0% +So uh that's a c that's a important + + + align:start position:0% +So uh that's a c that's a important +point that we'll use now in this + + align:start position:0% +point that we'll use now in this + + + align:start position:0% +point that we'll use now in this +lecture. + + align:start position:0% +lecture. + + + align:start position:0% +lecture. +So now I want to say what does it mean + + align:start position:0% +So now I want to say what does it mean + + + align:start position:0% +So now I want to say what does it mean +for a bunch of vectors to be + + align:start position:0% +for a bunch of vectors to be + + + align:start position:0% +for a bunch of vectors to be +independent. Okay. So this is like the + + align:start position:0% +independent. Okay. So this is like the + + + align:start position:0% +independent. Okay. So this is like the +background that we know. Now I want to + + align:start position:0% +background that we know. Now I want to + + + align:start position:0% +background that we know. Now I want to +speak about independence. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% + + + + align:start position:0% + +let's see. + + align:start position:0% +let's see. + + + align:start position:0% +let's see. +I can give you the the the + + align:start position:0% +I can give you the the the + + + align:start position:0% +I can give you the the the +uh abstract definition and I will but I + + align:start position:0% +uh abstract definition and I will but I + + + align:start position:0% +uh abstract definition and I will but I +would also like to give you the direct + + align:start position:0% +would also like to give you the direct + + + align:start position:0% +would also like to give you the direct +meaning when + + align:start position:0% +meaning when + + + align:start position:0% +meaning when +my so the question is when vectors + + align:start position:0% + + + + align:start position:0% + +x1 + + align:start position:0% +x1 + + + align:start position:0% +x1 +x2 up to suppose I have n vectors are + + align:start position:0% +x2 up to suppose I have n vectors are + + + align:start position:0% +x2 up to suppose I have n vectors are +independent + + align:start position:0% +independent + + + align:start position:0% +independent +If now I have to give you + + align:start position:0% +If now I have to give you + + + align:start position:0% +If now I have to give you +or linearly independent + + align:start position:0% +or linearly independent + + + align:start position:0% +or linearly independent +I'll I'll often just say and write + + align:start position:0% +I'll I'll often just say and write + + + align:start position:0% +I'll I'll often just say and write +independent for short if okay let I'll + + align:start position:0% +independent for short if okay let I'll + + + align:start position:0% +independent for short if okay let I'll +give you the full definition these are + + align:start position:0% +give you the full definition these are + + + align:start position:0% +give you the full definition these are +just vectors in some vector space I can + + align:start position:0% +just vectors in some vector space I can + + + align:start position:0% +just vectors in some vector space I can +take combinations of them the question + + align:start position:0% +take combinations of them the question + + + align:start position:0% +take combinations of them the question +is do any combinations give zero + + align:start position:0% +is do any combinations give zero + + + align:start position:0% +is do any combinations give zero +if some combination of those vectors + + align:start position:0% +if some combination of those vectors + + + align:start position:0% +if some combination of those vectors +gives the zero vector + + align:start position:0% +gives the zero vector + + + align:start position:0% +gives the zero vector +other than the combination of all zeros. + + align:start position:0% +other than the combination of all zeros. + + + align:start position:0% +other than the combination of all zeros. +Then they're dependent. + + align:start position:0% +Then they're dependent. + + + align:start position:0% +Then they're dependent. +They're independent if no + + align:start position:0% +They're independent if no + + + align:start position:0% +They're independent if no +combination + + align:start position:0% + + + + align:start position:0% + +gives + + align:start position:0% +gives + + + align:start position:0% +gives +the zero vector + + align:start position:0% +the zero vector + + + align:start position:0% +the zero vector +and then I have I'll have to put in and + + align:start position:0% +and then I have I'll have to put in and + + + align:start position:0% +and then I have I'll have to put in and +accept + + align:start position:0% +accept + + + align:start position:0% +accept +the + + align:start position:0% +the + + + align:start position:0% +the +zero + + align:start position:0% +zero + + + align:start position:0% +zero +combination. So what do I mean by that? + + align:start position:0% +combination. So what do I mean by that? + + + align:start position:0% +combination. So what do I mean by that? +No combination gives the zero vector. + + align:start position:0% +No combination gives the zero vector. + + + align:start position:0% +No combination gives the zero vector. +Any combination C1 X1 + C2 X2 + plus C N + + align:start position:0% +Any combination C1 X1 + C2 X2 + plus C N + + + align:start position:0% +Any combination C1 X1 + C2 X2 + plus C N +XN + + align:start position:0% +XN + + + align:start position:0% +XN +is not zero + + align:start position:0% + + + + align:start position:0% + +except for the zero combination. This is + + align:start position:0% +except for the zero combination. This is + + + align:start position:0% +except for the zero combination. This is +when all the C's all the C's are zero. + + align:start position:0% +when all the C's all the C's are zero. + + + align:start position:0% +when all the C's all the C's are zero. +Then of course + + align:start position:0% + + + + align:start position:0% + +that combination I I'm I know I'll get + + align:start position:0% +that combination I I'm I know I'll get + + + align:start position:0% +that combination I I'm I know I'll get +zero. But the the question is does any + + align:start position:0% +zero. But the the question is does any + + + align:start position:0% +zero. But the the question is does any +other combination give zero? If not + + align:start position:0% +other combination give zero? If not + + + align:start position:0% +other combination give zero? If not +then the vectors are independent. If + + align:start position:0% +then the vectors are independent. If + + + align:start position:0% +then the vectors are independent. If +some other combination does give zero + + align:start position:0% +some other combination does give zero + + + align:start position:0% +some other combination does give zero +the vectors are dependent. Okay let's + + align:start position:0% +the vectors are dependent. Okay let's + + + align:start position:0% +the vectors are dependent. Okay let's +just take examples. + + align:start position:0% +just take examples. + + + align:start position:0% +just take examples. +Suppose I'm in + + align:start position:0% +Suppose I'm in + + + align:start position:0% +Suppose I'm in +say in two-dimensional space. + + align:start position:0% +say in two-dimensional space. + + + align:start position:0% +say in two-dimensional space. +Okay I give you I I'd like to first take + + align:start position:0% +Okay I give you I I'd like to first take + + + align:start position:0% +Okay I give you I I'd like to first take +an example. Let me take an example where + + align:start position:0% +an example. Let me take an example where + + + align:start position:0% +an example. Let me take an example where +I have a vector and twice that vector. + + align:start position:0% +I have a vector and twice that vector. + + + align:start position:0% +I have a vector and twice that vector. +So that's two vectors V and 2V. Are + + align:start position:0% +So that's two vectors V and 2V. Are + + + align:start position:0% +So that's two vectors V and 2V. Are +those dependent or independent? + + align:start position:0% +those dependent or independent? + + + align:start position:0% +those dependent or independent? +Those are dependent for sure. Right? + + align:start position:0% +Those are dependent for sure. Right? + + + align:start position:0% +Those are dependent for sure. Right? +There's a combin one vector is twice the + + align:start position:0% +There's a combin one vector is twice the + + + align:start position:0% +There's a combin one vector is twice the +other. One vector is twice as long as + + align:start position:0% +other. One vector is twice as long as + + + align:start position:0% +other. One vector is twice as long as +the other. So if the word dependent + + align:start position:0% +the other. So if the word dependent + + + align:start position:0% +the other. So if the word dependent +means anything, these should be + + align:start position:0% +means anything, these should be + + + align:start position:0% +means anything, these should be +dependent. And they are. And in fact, I + + align:start position:0% +dependent. And they are. And in fact, I + + + align:start position:0% +dependent. And they are. And in fact, I +would take two of the first. So here's + + align:start position:0% +would take two of the first. So here's + + + align:start position:0% +would take two of the first. So here's +here's a vector V and the other guy is a + + align:start position:0% +here's a vector V and the other guy is a + + + align:start position:0% +here's a vector V and the other guy is a +vector 2V. That's my So there's a vector + + align:start position:0% +vector 2V. That's my So there's a vector + + + align:start position:0% +vector 2V. That's my So there's a vector +V1 and my ve my next vector V2 is 2 V1. + + align:start position:0% +V1 and my ve my next vector V2 is 2 V1. + + + align:start position:0% +V1 and my ve my next vector V2 is 2 V1. +Of course, those are dependent because + + align:start position:0% +Of course, those are dependent because + + + align:start position:0% +Of course, those are dependent because +two of these first vectors minus the + + align:start position:0% +two of these first vectors minus the + + + align:start position:0% +two of these first vectors minus the +second vector is zero. That's a + + align:start position:0% +second vector is zero. That's a + + + align:start position:0% +second vector is zero. That's a +combination of these two vectors that + + align:start position:0% +combination of these two vectors that + + + align:start position:0% +combination of these two vectors that +gives the zero vector. Okay, that was + + align:start position:0% +gives the zero vector. Okay, that was + + + align:start position:0% +gives the zero vector. Okay, that was +clear. Suppose suppose I have a vector. + + align:start position:0% +clear. Suppose suppose I have a vector. + + + align:start position:0% +clear. Suppose suppose I have a vector. +Here's another example. It's easy + + align:start position:0% +Here's another example. It's easy + + + align:start position:0% +Here's another example. It's easy +example. Suppose I have a vector and the + + align:start position:0% +example. Suppose I have a vector and the + + + align:start position:0% +example. Suppose I have a vector and the +other guy is the zero vector. Suppose I + + align:start position:0% +other guy is the zero vector. Suppose I + + + align:start position:0% +other guy is the zero vector. Suppose I +have a vector v1 and v2 is the zero + + align:start position:0% +have a vector v1 and v2 is the zero + + + align:start position:0% +have a vector v1 and v2 is the zero +vector. Then are those vectors dependent + + align:start position:0% +vector. Then are those vectors dependent + + + align:start position:0% +vector. Then are those vectors dependent +or independent? + + align:start position:0% +or independent? + + + align:start position:0% +or independent? +They're dependent. Again, + + align:start position:0% +They're dependent. Again, + + + align:start position:0% +They're dependent. Again, +you could say, well, this guy is zero + + align:start position:0% +you could say, well, this guy is zero + + + align:start position:0% +you could say, well, this guy is zero +times that one. This one is some + + align:start position:0% +times that one. This one is some + + + align:start position:0% +times that one. This one is some +combination of those. But let me write + + align:start position:0% +combination of those. But let me write + + + align:start position:0% +combination of those. But let me write +it the other way. Let me say what what + + align:start position:0% +it the other way. Let me say what what + + + align:start position:0% +it the other way. Let me say what what +combination how many V1s and how many + + align:start position:0% +combination how many V1s and how many + + + align:start position:0% +combination how many V1s and how many +V2s shall I take to get the zero vector? + + align:start position:0% +V2s shall I take to get the zero vector? + + + align:start position:0% +V2s shall I take to get the zero vector? +If if v_sub_1 is like the vector 21 and + + align:start position:0% +If if v_sub_1 is like the vector 21 and + + + align:start position:0% +If if v_sub_1 is like the vector 21 and +v2 is the zero vector 0 0 then I would + + align:start position:0% +v2 is the zero vector 0 0 then I would + + + align:start position:0% +v2 is the zero vector 0 0 then I would +like to show that some combination of + + align:start position:0% +like to show that some combination of + + + align:start position:0% +like to show that some combination of +those gives the zero vector. What shall + + align:start position:0% +those gives the zero vector. What shall + + + align:start position:0% +those gives the zero vector. What shall +I take? How many v1's shall I take? + + align:start position:0% +I take? How many v1's shall I take? + + + align:start position:0% +I take? How many v1's shall I take? +Zero of them. Yeah. No. Take no v1s. But + + align:start position:0% +Zero of them. Yeah. No. Take no v1s. But + + + align:start position:0% +Zero of them. Yeah. No. Take no v1s. But +how many v2s? + + align:start position:0% +how many v2s? + + + align:start position:0% +how many v2s? +Six. Okay. + + align:start position:0% +Six. Okay. + + + align:start position:0% +Six. Okay. +or five. + + align:start position:0% +or five. + + + align:start position:0% +or five. +Then in other words, the point is if the + + align:start position:0% +Then in other words, the point is if the + + + align:start position:0% +Then in other words, the point is if the +zero vectors in there, if the zero if if + + align:start position:0% +zero vectors in there, if the zero if if + + + align:start position:0% +zero vectors in there, if the zero if if +one of these vectors is the zero vector, + + align:start position:0% +one of these vectors is the zero vector, + + + align:start position:0% +one of these vectors is the zero vector, +independence is dead, right? If one of + + align:start position:0% +independence is dead, right? If one of + + + align:start position:0% +independence is dead, right? If one of +those vectors is the zero vector, then I + + align:start position:0% +those vectors is the zero vector, then I + + + align:start position:0% +those vectors is the zero vector, then I +could always take + + align:start position:0% +could always take + + + align:start position:0% +could always take +include that one and none of the others + + align:start position:0% +include that one and none of the others + + + align:start position:0% +include that one and none of the others +and I would get the zero answer and I + + align:start position:0% +and I would get the zero answer and I + + + align:start position:0% +and I would get the zero answer and I +would show dependence. Okay. Now uh let + + align:start position:0% +would show dependence. Okay. Now uh let + + + align:start position:0% +would show dependence. Okay. Now uh let +me let me finally draw an example where + + align:start position:0% +me let me finally draw an example where + + + align:start position:0% +me let me finally draw an example where +they will be independent. Suppose that's + + align:start position:0% +they will be independent. Suppose that's + + + align:start position:0% +they will be independent. Suppose that's +v1 and that's v2. + + align:start position:0% +v1 and that's v2. + + + align:start position:0% +v1 and that's v2. +Those are surely independent right. Any + + align:start position:0% +Those are surely independent right. Any + + + align:start position:0% +Those are surely independent right. Any +combination of v_sub_1 and v2 uh will + + align:start position:0% +combination of v_sub_1 and v2 uh will + + + align:start position:0% +combination of v_sub_1 and v2 uh will +not be zero except uh the zero + + align:start position:0% +not be zero except uh the zero + + + align:start position:0% +not be zero except uh the zero +combination. So those would be + + align:start position:0% +combination. So those would be + + + align:start position:0% +combination. So those would be +independent. But now let me let me stick + + align:start position:0% +independent. But now let me let me stick + + + align:start position:0% +independent. But now let me let me stick +in a third vector v3. + + align:start position:0% + + + + align:start position:0% + +independent or dependent. Now those + + align:start position:0% +independent or dependent. Now those + + + align:start position:0% +independent or dependent. Now those +three vectors. So now n is three. Here + + align:start position:0% +three vectors. So now n is three. Here + + + align:start position:0% +three vectors. So now n is three. Here +I'm in two-dimensional space. Whatever + + align:start position:0% +I'm in two-dimensional space. Whatever + + + align:start position:0% +I'm in two-dimensional space. Whatever +I'm in the plane I have three vectors + + align:start position:0% +I'm in the plane I have three vectors + + + align:start position:0% +I'm in the plane I have three vectors +that I didn't draw so carefully. I + + align:start position:0% +that I didn't draw so carefully. I + + + align:start position:0% +that I didn't draw so carefully. I +didn't even tell you what exactly they + + align:start position:0% +didn't even tell you what exactly they + + + align:start position:0% +didn't even tell you what exactly they +were. But what's this answer on + + align:start position:0% +were. But what's this answer on + + + align:start position:0% +were. But what's this answer on +dependent or independent? + + align:start position:0% +dependent or independent? + + + align:start position:0% +dependent or independent? +Dependent. Why? How do I know the those + + align:start position:0% +Dependent. Why? How do I know the those + + + align:start position:0% +Dependent. Why? How do I know the those +are dependent? + + align:start position:0% +are dependent? + + + align:start position:0% +are dependent? +How do I know that some combination of + + align:start position:0% +How do I know that some combination of + + + align:start position:0% +How do I know that some combination of +vub1, v2 and v3 gives me the zero + + align:start position:0% +vub1, v2 and v3 gives me the zero + + + align:start position:0% +vub1, v2 and v3 gives me the zero +vector? + + align:start position:0% +vector? + + + align:start position:0% +vector? +I know because of that that's the that's + + align:start position:0% +I know because of that that's the that's + + + align:start position:0% +I know because of that that's the that's +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +key fact + + align:start position:0% +key fact + + + align:start position:0% +key fact +that tells me that three vectors in the + + align:start position:0% +that tells me that three vectors in the + + + align:start position:0% +that tells me that three vectors in the +plane have to be dependent. Why is that? + + align:start position:0% +plane have to be dependent. Why is that? + + + align:start position:0% +plane have to be dependent. Why is that? +What's the connection between the + + align:start position:0% +What's the connection between the + + + align:start position:0% +What's the connection between the +dependence of these three vectors and + + align:start position:0% +dependence of these three vectors and + + + align:start position:0% +dependence of these three vectors and +that fact? Okay, so here's the + + align:start position:0% +that fact? Okay, so here's the + + + align:start position:0% +that fact? Okay, so here's the +connection. I take the matrix A + + align:start position:0% +connection. I take the matrix A + + + align:start position:0% +connection. I take the matrix A +that has V1 in its first column, + + align:start position:0% +that has V1 in its first column, + + + align:start position:0% +that has V1 in its first column, +V2 in its second column, V3 in its third + + align:start position:0% +V2 in its second column, V3 in its third + + + align:start position:0% +V2 in its second column, V3 in its third +column. + + align:start position:0% +column. + + + align:start position:0% +column. +So it's got three columns. And V1, I + + align:start position:0% +So it's got three columns. And V1, I + + + align:start position:0% +So it's got three columns. And V1, I +don't know, that looks like about 21 to + + align:start position:0% +don't know, that looks like about 21 to + + + align:start position:0% +don't know, that looks like about 21 to +me. V2 looks like it might be one two. + + align:start position:0% +me. V2 looks like it might be one two. + + + align:start position:0% +me. V2 looks like it might be one two. +V3 looks like it might be maybe two + + align:start position:0% +V3 looks like it might be maybe two + + + align:start position:0% +V3 looks like it might be maybe two +maybe two and a half + + align:start position:0% +maybe two and a half + + + align:start position:0% +maybe two and a half +minus one. + + align:start position:0% + + + + align:start position:0% + +Okay, those are three. Those are my + + align:start position:0% +Okay, those are three. Those are my + + + align:start position:0% +Okay, those are three. Those are my +three vectors and I put them in the + + align:start position:0% +three vectors and I put them in the + + + align:start position:0% +three vectors and I put them in the +columns of A. + + align:start position:0% +columns of A. + + + align:start position:0% +columns of A. +Now that matrix A is 2x3. It fits this + + align:start position:0% +Now that matrix A is 2x3. It fits this + + + align:start position:0% +Now that matrix A is 2x3. It fits this +pattern that where we know we've got + + align:start position:0% +pattern that where we know we've got + + + align:start position:0% +pattern that where we know we've got +extra variables. We know we have some + + align:start position:0% +extra variables. We know we have some + + + align:start position:0% +extra variables. We know we have some +free variables. We know that there's + + align:start position:0% +free variables. We know that there's + + + align:start position:0% +free variables. We know that there's +some combination and let me instead of + + align:start position:0% +some combination and let me instead of + + + align:start position:0% +some combination and let me instead of +X's, let me call them C1, C2, and C3 + + align:start position:0% +X's, let me call them C1, C2, and C3 + + + align:start position:0% +X's, let me call them C1, C2, and C3 +that gives the zero vector. + + align:start position:0% +that gives the zero vector. + + + align:start position:0% +that gives the zero vector. +Sorry that my little bit of art got in + + align:start position:0% +Sorry that my little bit of art got in + + + align:start position:0% +Sorry that my little bit of art got in +the way. Do you see the point? When I + + align:start position:0% +the way. Do you see the point? When I + + + align:start position:0% +the way. Do you see the point? When I +have a matrix, + + align:start position:0% +have a matrix, + + + align:start position:0% +have a matrix, +I'm interested in whether its columns + + align:start position:0% +I'm interested in whether its columns + + + align:start position:0% +I'm interested in whether its columns +are dependent or independent. + + align:start position:0% +are dependent or independent. + + + align:start position:0% +are dependent or independent. +The columns are dependent if there is + + align:start position:0% +The columns are dependent if there is + + + align:start position:0% +The columns are dependent if there is +something in the null space. The columns + + align:start position:0% +something in the null space. The columns + + + align:start position:0% +something in the null space. The columns +are dependent because this this thing in + + align:start position:0% +are dependent because this this thing in + + + align:start position:0% +are dependent because this this thing in +the null space says that C1 of that plus + + align:start position:0% +the null space says that C1 of that plus + + + align:start position:0% +the null space says that C1 of that plus +C2 of that plus C3 of this is zero. So + + align:start position:0% +C2 of that plus C3 of this is zero. So + + + align:start position:0% +C2 of that plus C3 of this is zero. So +in other words, I can go out some V1 out + + align:start position:0% +in other words, I can go out some V1 out + + + align:start position:0% +in other words, I can go out some V1 out +some more V2 back on V3 and end up zero. + + align:start position:0% + + + + align:start position:0% + +Okay. So let + + align:start position:0% +Okay. So let + + + align:start position:0% +Okay. So let +here I've given the general abstract + + align:start position:0% +here I've given the general abstract + + + align:start position:0% +here I've given the general abstract +definition but let me repeat that + + align:start position:0% +definition but let me repeat that + + + align:start position:0% +definition but let me repeat that +definition. So this is like repeat + + align:start position:0% +definition. So this is like repeat + + + align:start position:0% +definition. So this is like repeat +when + + align:start position:0% +when + + + align:start position:0% +when +for + + align:start position:0% +for + + + align:start position:0% +for +when the v1 let me call them v's now v1 + + align:start position:0% +when the v1 let me call them v's now v1 + + + align:start position:0% +when the v1 let me call them v's now v1 +up to vn are the columns + + align:start position:0% +up to vn are the columns + + + align:start position:0% +up to vn are the columns +of a matrix a + + align:start position:0% +of a matrix a + + + align:start position:0% +of a matrix a +in other words this is telling me that + + align:start position:0% +in other words this is telling me that + + + align:start position:0% +in other words this is telling me that +if I'm in if I'm in n if I'm in uh md + + align:start position:0% +if I'm in if I'm in n if I'm in uh md + + + align:start position:0% +if I'm in if I'm in n if I'm in uh md +dimensional space like two-dimensional + + align:start position:0% +dimensional space like two-dimensional + + + align:start position:0% +dimensional space like two-dimensional +space in the example. I can answer the + + align:start position:0% +space in the example. I can answer the + + + align:start position:0% +space in the example. I can answer the +dependence independence question + + align:start position:0% +dependence independence question + + + align:start position:0% +dependence independence question +directly + + align:start position:0% +directly + + + align:start position:0% +directly +by putting those vectors in the columns + + align:start position:0% +by putting those vectors in the columns + + + align:start position:0% +by putting those vectors in the columns +of a matrix. Then they independent. They + + align:start position:0% +of a matrix. Then they independent. They + + + align:start position:0% +of a matrix. Then they independent. They +are independent. + + align:start position:0% + + + + align:start position:0% + +Independent + + align:start position:0% +Independent + + + align:start position:0% +Independent +if + + align:start position:0% +if + + + align:start position:0% +if +the null space of A + + align:start position:0% +the null space of A + + + align:start position:0% +the null space of A +of A is what? + + align:start position:0% + + + + align:start position:0% + +If I have a bunch of columns in a + + align:start position:0% +If I have a bunch of columns in a + + + align:start position:0% +If I have a bunch of columns in a +matrix, + + align:start position:0% +matrix, + + + align:start position:0% +matrix, +I'm looking at their combinations, but + + align:start position:0% +I'm looking at their combinations, but + + + align:start position:0% +I'm looking at their combinations, but +that's just A times + + align:start position:0% +that's just A times + + + align:start position:0% +that's just A times +the vector of C's + + align:start position:0% +the vector of C's + + + align:start position:0% +the vector of C's +and the ve and these columns will be + + align:start position:0% +and the ve and these columns will be + + + align:start position:0% +and the ve and these columns will be +independent if the null space of A is + + align:start position:0% +independent if the null space of A is + + + align:start position:0% +independent if the null space of A is +only the zero vector is only is the zero + + align:start position:0% +only the zero vector is only is the zero + + + align:start position:0% +only the zero vector is only is the zero +vector. + + align:start position:0% + + + + align:start position:0% + +They are dependent + + align:start position:0% + + + + align:start position:0% + +if there's something else in there. If + + align:start position:0% +if there's something else in there. If + + + align:start position:0% +if there's something else in there. If +there's something else in the null + + align:start position:0% +there's something else in the null + + + align:start position:0% +there's something else in the null +space, if a * c gives the zero vector + + align:start position:0% +space, if a * c gives the zero vector + + + align:start position:0% +space, if a * c gives the zero vector +for some nonzero + + align:start position:0% +for some nonzero + + + align:start position:0% +for some nonzero +vector c in the null space, + + align:start position:0% +vector c in the null space, + + + align:start position:0% +vector c in the null space, +then they're dependent because that's + + align:start position:0% +then they're dependent because that's + + + align:start position:0% +then they're dependent because that's +telling me a combination of the columns + + align:start position:0% +telling me a combination of the columns + + + align:start position:0% +telling me a combination of the columns +gives the zero column. I I I think + + align:start position:0% +gives the zero column. I I I think + + + align:start position:0% +gives the zero column. I I I think +you're with me because we've seen like + + align:start position:0% +you're with me because we've seen like + + + align:start position:0% +you're with me because we've seen like +lecture after lecture we're looking at + + align:start position:0% +lecture after lecture we're looking at + + + align:start position:0% +lecture after lecture we're looking at +the combinations of the columns and + + align:start position:0% +the combinations of the columns and + + + align:start position:0% +the combinations of the columns and +asking do we get zero or don't we and + + align:start position:0% +asking do we get zero or don't we and + + + align:start position:0% +asking do we get zero or don't we and +now we're giving the official name + + align:start position:0% +now we're giving the official name + + + align:start position:0% +now we're giving the official name +dependent if we do independent if we + + align:start position:0% +dependent if we do independent if we + + + align:start position:0% +dependent if we do independent if we +don't so I could express this in other + + align:start position:0% +don't so I could express this in other + + + align:start position:0% +don't so I could express this in other +words now I could say the rank what's + + align:start position:0% +words now I could say the rank what's + + + align:start position:0% +words now I could say the rank what's +the rank in this independent case the + + align:start position:0% +the rank in this independent case the + + + align:start position:0% +the rank in this independent case the +rank R of of the matrix in the case of + + align:start position:0% +rank R of of the matrix in the case of + + + align:start position:0% +rank R of of the matrix in the case of +independent columns is + + align:start position:0% + + + + align:start position:0% + +so the columns are independent. + + align:start position:0% +so the columns are independent. + + + align:start position:0% +so the columns are independent. +So how many pivot columns have I got? + + align:start position:0% +So how many pivot columns have I got? + + + align:start position:0% +So how many pivot columns have I got? +All in all the columns would be pivot + + align:start position:0% +All in all the columns would be pivot + + + align:start position:0% +All in all the columns would be pivot +columns + + align:start position:0% +columns + + + align:start position:0% +columns +because free columns are telling me that + + align:start position:0% +because free columns are telling me that + + + align:start position:0% +because free columns are telling me that +they're a combination of earlier + + align:start position:0% +they're a combination of earlier + + + align:start position:0% +they're a combination of earlier +columns. So this would be the case where + + align:start position:0% +columns. So this would be the case where + + + align:start position:0% +columns. So this would be the case where +the rank is n. This would be the case + + align:start position:0% +the rank is n. This would be the case + + + align:start position:0% +the rank is n. This would be the case +where the rank is smaller than n. + + align:start position:0% +where the rank is smaller than n. + + + align:start position:0% +where the rank is smaller than n. +So in this case the rank is n and the + + align:start position:0% +So in this case the rank is n and the + + + align:start position:0% +So in this case the rank is n and the +null space of a is only the zero vector + + align:start position:0% +null space of a is only the zero vector + + + align:start position:0% +null space of a is only the zero vector +and no free variables. No free + + align:start position:0% +and no free variables. No free + + + align:start position:0% +and no free variables. No free +variables. + + align:start position:0% + + + + align:start position:0% + +And this is the case. Yes. free + + align:start position:0% +And this is the case. Yes. free + + + align:start position:0% +And this is the case. Yes. free +variables + + align:start position:0% + + + + align:start position:0% + +if you'll allow me to stretch the + + align:start position:0% +if you'll allow me to stretch the + + + align:start position:0% +if you'll allow me to stretch the +English language that far. Uh that's the + + align:start position:0% +English language that far. Uh that's the + + + align:start position:0% +English language that far. Uh that's the +case where we have + + align:start position:0% +case where we have + + + align:start position:0% +case where we have +um + + align:start position:0% +um + + + align:start position:0% +um +a combination that gives the zero + + align:start position:0% +a combination that gives the zero + + + align:start position:0% +a combination that gives the zero +column. So I I'm often interested in the + + align:start position:0% +column. So I I'm often interested in the + + + align:start position:0% +column. So I I'm often interested in the +case when my vectors are popped into a + + align:start position:0% +case when my vectors are popped into a + + + align:start position:0% +case when my vectors are popped into a +matrix. + + align:start position:0% +matrix. + + + align:start position:0% +matrix. +So the the definition over there of + + align:start position:0% +So the the definition over there of + + + align:start position:0% +So the the definition over there of +independence didn't talk about any + + align:start position:0% +independence didn't talk about any + + + align:start position:0% +independence didn't talk about any +matrix. + + align:start position:0% +matrix. + + + align:start position:0% +matrix. +The vectors didn't have to be vectors in + + align:start position:0% +The vectors didn't have to be vectors in + + + align:start position:0% +The vectors didn't have to be vectors in +n-dimensional space. And I I want to + + align:start position:0% +n-dimensional space. And I I want to + + + align:start position:0% +n-dimensional space. And I I want to +give it some examples of vectors that + + align:start position:0% +give it some examples of vectors that + + + align:start position:0% +give it some examples of vectors that +aren't what you think of immediately as + + align:start position:0% +aren't what you think of immediately as + + + align:start position:0% +aren't what you think of immediately as +vectors. But most of the time this is + + align:start position:0% +vectors. But most of the time this is + + + align:start position:0% +vectors. But most of the time this is +the we the vectors we think of are + + align:start position:0% +the we the vectors we think of are + + + align:start position:0% +the we the vectors we think of are +columns + + align:start position:0% +columns + + + align:start position:0% +columns +and we can put them in a matrix and then + + align:start position:0% +and we can put them in a matrix and then + + + align:start position:0% +and we can put them in a matrix and then +independence or dependence comes back to + + align:start position:0% +independence or dependence comes back to + + + align:start position:0% +independence or dependence comes back to +the null space. + + align:start position:0% +the null space. + + + align:start position:0% +the null space. +Okay. So that's the idea of + + align:start position:0% +Okay. So that's the idea of + + + align:start position:0% +Okay. So that's the idea of +independence. + + align:start position:0% + + + + align:start position:0% + +Can I just uh + + align:start position:0% +Can I just uh + + + align:start position:0% +Can I just uh +yeah let me let me go on to spanning a + + align:start position:0% +yeah let me let me go on to spanning a + + + align:start position:0% +yeah let me let me go on to spanning a +space. + + align:start position:0% +space. + + + align:start position:0% +space. +What does it mean for a bunch of vectors + + align:start position:0% +What does it mean for a bunch of vectors + + + align:start position:0% +What does it mean for a bunch of vectors +to span a space? + + align:start position:0% +to span a space? + + + align:start position:0% +to span a space? +Well, actually, we've seen it already. + + align:start position:0% +Well, actually, we've seen it already. + + + align:start position:0% +Well, actually, we've seen it already. +You remember if if we had a columns in a + + align:start position:0% +You remember if if we had a columns in a + + + align:start position:0% +You remember if if we had a columns in a +matrix, + + align:start position:0% +matrix, + + + align:start position:0% +matrix, +we took all their combinations + + align:start position:0% +we took all their combinations + + + align:start position:0% +we took all their combinations +and that gave us the column space. + + align:start position:0% +and that gave us the column space. + + + align:start position:0% +and that gave us the column space. +Those vectors that we started with span + + align:start position:0% +Those vectors that we started with span + + + align:start position:0% +Those vectors that we started with span +that column space. So spanning a space + + align:start position:0% +that column space. So spanning a space + + + align:start position:0% +that column space. So spanning a space +means + + align:start position:0% +means + + + align:start position:0% +means +so let me move that important stuff + + align:start position:0% +so let me move that important stuff + + + align:start position:0% +so let me move that important stuff +right up. + + align:start position:0% + + + + align:start position:0% + +Okay. So vectors + + align:start position:0% + + + + align:start position:0% + +let me call them say V1 up to I'll use + + align:start position:0% +let me call them say V1 up to I'll use + + + align:start position:0% +let me call them say V1 up to I'll use +some different letter say V L + + align:start position:0% +some different letter say V L + + + align:start position:0% +some different letter say V L +span + + align:start position:0% +span + + + align:start position:0% +span +a space + + align:start position:0% +a space + + + align:start position:0% +a space +a subspace + + align:start position:0% +a subspace + + + align:start position:0% +a subspace +or just a vector space I could say span + + align:start position:0% +or just a vector space I could say span + + + align:start position:0% +or just a vector space I could say span +a space means + + align:start position:0% +a space means + + + align:start position:0% +a space means +means + + align:start position:0% + + + + align:start position:0% + +The space + + align:start position:0% +The space + + + align:start position:0% +The space +consists of + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +combinations + + align:start position:0% + + + + align:start position:0% + +of those vectors. + + align:start position:0% + + + + align:start position:0% + +That that's exactly what we did with the + + align:start position:0% +That that's exactly what we did with the + + + align:start position:0% +That that's exactly what we did with the +column space. + + align:start position:0% +column space. + + + align:start position:0% +column space. +So now I could say in shorthand the + + align:start position:0% +So now I could say in shorthand the + + + align:start position:0% +So now I could say in shorthand the +columns of a matrix span the column + + align:start position:0% +columns of a matrix span the column + + + align:start position:0% +columns of a matrix span the column +space. + + align:start position:0% +space. + + + align:start position:0% +space. +So remember it's a bunch of vectors that + + align:start position:0% +So remember it's a bunch of vectors that + + + align:start position:0% +So remember it's a bunch of vectors that +have this property that they span a + + align:start position:0% +have this property that they span a + + + align:start position:0% +have this property that they span a +space. And actually + + align:start position:0% +space. And actually + + + align:start position:0% +space. And actually +if I give you a bunch of vectors and say + + align:start position:0% +if I give you a bunch of vectors and say + + + align:start position:0% +if I give you a bunch of vectors and say +okay let s be the space that they span. + + align:start position:0% +okay let s be the space that they span. + + + align:start position:0% +okay let s be the space that they span. +In other words let s contain all their + + align:start position:0% +In other words let s contain all their + + + align:start position:0% +In other words let s contain all their +combinations. + + align:start position:0% +combinations. + + + align:start position:0% +combinations. +that space s will be the smallest space + + align:start position:0% +that space s will be the smallest space + + + align:start position:0% +that space s will be the smallest space +with those vectors in it. Right? Because + + align:start position:0% +with those vectors in it. Right? Because + + + align:start position:0% +with those vectors in it. Right? Because +any space with those vectors in it must + + align:start position:0% +any space with those vectors in it must + + + align:start position:0% +any space with those vectors in it must +have all the combinations of those + + align:start position:0% +have all the combinations of those + + + align:start position:0% +have all the combinations of those +vectors in it. And if I stop there, + + align:start position:0% +vectors in it. And if I stop there, + + + align:start position:0% +vectors in it. And if I stop there, +then I've got the smallest space and + + align:start position:0% +then I've got the smallest space and + + + align:start position:0% +then I've got the smallest space and +that's the space that they span. Okay? + + align:start position:0% +that's the space that they span. Okay? + + + align:start position:0% +that's the space that they span. Okay? +So I'm just rather than uh needing to + + align:start position:0% +So I'm just rather than uh needing to + + + align:start position:0% +So I'm just rather than uh needing to +say take all linear combinations and put + + align:start position:0% +say take all linear combinations and put + + + align:start position:0% +say take all linear combinations and put +them in a space, I'm I'm compressing + + align:start position:0% +them in a space, I'm I'm compressing + + + align:start position:0% +them in a space, I'm I'm compressing +that + + align:start position:0% +that + + + align:start position:0% +that +into the word span. + + align:start position:0% + + + + align:start position:0% + +Straightforward. + + align:start position:0% +Straightforward. + + + align:start position:0% +Straightforward. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So if I think of a of the column space + + align:start position:0% +So if I think of a of the column space + + + align:start position:0% +So if I think of a of the column space +of a matrix, + + align:start position:0% +of a matrix, + + + align:start position:0% +of a matrix, +I've got I've got their So I start with + + align:start position:0% +I've got I've got their So I start with + + + align:start position:0% +I've got I've got their So I start with +the columns. I take all their + + align:start position:0% +the columns. I take all their + + + align:start position:0% +the columns. I take all their +combinations that gives me the column + + align:start position:0% +combinations that gives me the column + + + align:start position:0% +combinations that gives me the column +space. They span the column space. Now, + + align:start position:0% +space. They span the column space. Now, + + + align:start position:0% +space. They span the column space. Now, +are they independent? + + align:start position:0% +are they independent? + + + align:start position:0% +are they independent? +Maybe yes, maybe no. + + align:start position:0% +Maybe yes, maybe no. + + + align:start position:0% +Maybe yes, maybe no. +It depends on the particular columns + + align:start position:0% +It depends on the particular columns + + + align:start position:0% +It depends on the particular columns +that went into that matrix. + + align:start position:0% +that went into that matrix. + + + align:start position:0% +that went into that matrix. +But obviously, I'm highly interested in + + align:start position:0% +But obviously, I'm highly interested in + + + align:start position:0% +But obviously, I'm highly interested in +a set of vectors + + align:start position:0% +a set of vectors + + + align:start position:0% +a set of vectors +that spans the space and is independent. + + align:start position:0% +that spans the space and is independent. + + + align:start position:0% +that spans the space and is independent. +That's that means like I've got the + + align:start position:0% +That's that means like I've got the + + + align:start position:0% +That's that means like I've got the +right number of vectors. + + align:start position:0% +right number of vectors. + + + align:start position:0% +right number of vectors. +If I didn't have all of them, I wouldn't + + align:start position:0% +If I didn't have all of them, I wouldn't + + + align:start position:0% +If I didn't have all of them, I wouldn't +have my whole space. + + align:start position:0% +have my whole space. + + + align:start position:0% +have my whole space. +If I had more than that, they probably + + align:start position:0% +If I had more than that, they probably + + + align:start position:0% +If I had more than that, they probably +wouldn't they wouldn't be independent. + + align:start position:0% +wouldn't they wouldn't be independent. + + + align:start position:0% +wouldn't they wouldn't be independent. +So like basis and that's the word that's + + align:start position:0% +So like basis and that's the word that's + + + align:start position:0% +So like basis and that's the word that's +coming is just right. So here let me put + + align:start position:0% +coming is just right. So here let me put + + + align:start position:0% +coming is just right. So here let me put +what that word means. A basis + + align:start position:0% + + + + align:start position:0% + +for a vector for a vector space is + + align:start position:0% +for a vector for a vector space is + + + align:start position:0% +for a vector for a vector space is +is a is a sequence of vectors + + align:start position:0% + + + + align:start position:0% + +shall I call them v1 v2 + + align:start position:0% +shall I call them v1 v2 + + + align:start position:0% +shall I call them v1 v2 +up to let me say v d now I'll stop with + + align:start position:0% +up to let me say v d now I'll stop with + + + align:start position:0% +up to let me say v d now I'll stop with +that letters that has two properties. + + align:start position:0% +that letters that has two properties. + + + align:start position:0% +that letters that has two properties. +I've got enough vectors and not too + + align:start position:0% +I've got enough vectors and not too + + + align:start position:0% +I've got enough vectors and not too +many. It's a natural idea of a basis. So + + align:start position:0% +many. It's a natural idea of a basis. So + + + align:start position:0% +many. It's a natural idea of a basis. So +a basis is a bunch of vectors in the + + align:start position:0% +a basis is a bunch of vectors in the + + + align:start position:0% +a basis is a bunch of vectors in the +space + + align:start position:0% +space + + + align:start position:0% +space +and it's a so it's a sequence of vectors + + align:start position:0% +and it's a so it's a sequence of vectors + + + align:start position:0% +and it's a so it's a sequence of vectors +with two properties with + + align:start position:0% +with two properties with + + + align:start position:0% +with two properties with +two properties. + + align:start position:0% + + + + align:start position:0% + +One, + + align:start position:0% +One, + + + align:start position:0% +One, +they are independent. + + align:start position:0% + + + + align:start position:0% + +And two, + + align:start position:0% +And two, + + + align:start position:0% +And two, +you know what's coming? They span the + + align:start position:0% +you know what's coming? They span the + + + align:start position:0% +you know what's coming? They span the +space. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +let me take + + align:start position:0% +let me take + + + align:start position:0% +let me take +So time for examples of course. + + align:start position:0% +So time for examples of course. + + + align:start position:0% +So time for examples of course. +So I'm asking you now to put definition + + align:start position:0% +So I'm asking you now to put definition + + + align:start position:0% +So I'm asking you now to put definition +one the definition of independence + + align:start position:0% +one the definition of independence + + + align:start position:0% +one the definition of independence +together with definition two and let's + + align:start position:0% +together with definition two and let's + + + align:start position:0% +together with definition two and let's +look at examples because this is this + + align:start position:0% +look at examples because this is this + + + align:start position:0% +look at examples because this is this +combination means the set of of vectors + + align:start position:0% +combination means the set of of vectors + + + align:start position:0% +combination means the set of of vectors +I have is just right and that so that + + align:start position:0% +I have is just right and that so that + + + align:start position:0% +I have is just right and that so that +this idea of a basis will be central. + + align:start position:0% +this idea of a basis will be central. + + + align:start position:0% +this idea of a basis will be central. +I'll always be asking you now for a + + align:start position:0% +I'll always be asking you now for a + + + align:start position:0% +I'll always be asking you now for a +basis. Whenever I look at a subspace, + + align:start position:0% +basis. Whenever I look at a subspace, + + + align:start position:0% +basis. Whenever I look at a subspace, +if I ask you for if you give me a basis + + align:start position:0% +if I ask you for if you give me a basis + + + align:start position:0% +if I ask you for if you give me a basis +for that subspace, you've told me what + + align:start position:0% +for that subspace, you've told me what + + + align:start position:0% +for that subspace, you've told me what +it is. You've told me everything I need + + align:start position:0% +it is. You've told me everything I need + + + align:start position:0% +it is. You've told me everything I need +to know about that subspace. Those I + + align:start position:0% +to know about that subspace. Those I + + + align:start position:0% +to know about that subspace. Those I +take their combinations and I know that + + align:start position:0% +take their combinations and I know that + + + align:start position:0% +take their combinations and I know that +I need all the combinations. Okay. + + align:start position:0% +I need all the combinations. Okay. + + + align:start position:0% +I need all the combinations. Okay. +Examples. + + align:start position:0% +Examples. + + + align:start position:0% +Examples. +Okay. So, examples of a basis. Let me + + align:start position:0% +Okay. So, examples of a basis. Let me + + + align:start position:0% +Okay. So, examples of a basis. Let me +start with two-dimensional space. + + align:start position:0% +start with two-dimensional space. + + + align:start position:0% +start with two-dimensional space. +Suppose the the space say example + + align:start position:0% + + + + align:start position:0% + +the space is + + align:start position:0% +the space is + + + align:start position:0% +the space is +uh let's make it R3 + + align:start position:0% +uh let's make it R3 + + + align:start position:0% +uh let's make it R3 +real threedimensional space + + align:start position:0% +real threedimensional space + + + align:start position:0% +real threedimensional space +give me one basis one basis is + + align:start position:0% + + + + align:start position:0% + +so I want some vectors + + align:start position:0% +so I want some vectors + + + align:start position:0% +so I want some vectors +because if I ask you for a basis I'm + + align:start position:0% +because if I ask you for a basis I'm + + + align:start position:0% +because if I ask you for a basis I'm +asking you for vectors a little list of + + align:start position:0% +asking you for vectors a little list of + + + align:start position:0% +asking you for vectors a little list of +vectors + + align:start position:0% +vectors + + + align:start position:0% +vectors +and + + align:start position:0% +and + + + align:start position:0% +and +it should be just right. So what would + + align:start position:0% +it should be just right. So what would + + + align:start position:0% +it should be just right. So what would +be a basis for three-dimensional space? + + align:start position:0% +be a basis for three-dimensional space? + + + align:start position:0% +be a basis for three-dimensional space? +Well, the first basis that comes to + + align:start position:0% +Well, the first basis that comes to + + + align:start position:0% +Well, the first basis that comes to +mind, why don't we write that down? The + + align:start position:0% +mind, why don't we write that down? The + + + align:start position:0% +mind, why don't we write that down? The +first basis that comes to mind is this + + align:start position:0% +first basis that comes to mind is this + + + align:start position:0% +first basis that comes to mind is this +vector, + + align:start position:0% +vector, + + + align:start position:0% +vector, +this vector, + + align:start position:0% +this vector, + + + align:start position:0% +this vector, +and this vector. + + align:start position:0% +and this vector. + + + align:start position:0% +and this vector. +Okay, that's one basis. + + align:start position:0% +Okay, that's one basis. + + + align:start position:0% +Okay, that's one basis. +Not the only basis. That's going to be + + align:start position:0% +Not the only basis. That's going to be + + + align:start position:0% +Not the only basis. That's going to be +my point. + + align:start position:0% +my point. + + + align:start position:0% +my point. +But let's just see. Yes, that's a basis. + + align:start position:0% +But let's just see. Yes, that's a basis. + + + align:start position:0% +But let's just see. Yes, that's a basis. +Is every are those vectors independent? + + align:start position:0% +Is every are those vectors independent? + + + align:start position:0% +Is every are those vectors independent? +So that's the like the X, Y, and Z axis. + + align:start position:0% +So that's the like the X, Y, and Z axis. + + + align:start position:0% +So that's the like the X, Y, and Z axis. +So if those are not independent, we're + + align:start position:0% +So if those are not independent, we're + + + align:start position:0% +So if those are not independent, we're +in trouble. Certainly they are. Take a + + align:start position:0% +in trouble. Certainly they are. Take a + + + align:start position:0% +in trouble. Certainly they are. Take a +combination C1 of this vector plus C2 of + + align:start position:0% +combination C1 of this vector plus C2 of + + + align:start position:0% +combination C1 of this vector plus C2 of +this vector plus C3 of that vector and + + align:start position:0% +this vector plus C3 of that vector and + + + align:start position:0% +this vector plus C3 of that vector and +try to make it give the zero vector. + + align:start position:0% +try to make it give the zero vector. + + + align:start position:0% +try to make it give the zero vector. +What are the C's? + + align:start position:0% +What are the C's? + + + align:start position:0% +What are the C's? +If C1 of that plus C2 of that plus C3 of + + align:start position:0% +If C1 of that plus C2 of that plus C3 of + + + align:start position:0% +If C1 of that plus C2 of that plus C3 of +that gives me 0 0, then the C's are all + + align:start position:0% +that gives me 0 0, then the C's are all + + + align:start position:0% +that gives me 0 0, then the C's are all +zero. Right? So that's the test for + + align:start position:0% +zero. Right? So that's the test for + + + align:start position:0% +zero. Right? So that's the test for +independence + + align:start position:0% +independence + + + align:start position:0% +independence +in the language of matrices. + + align:start position:0% +in the language of matrices. + + + align:start position:0% +in the language of matrices. +which was under that board. I could make + + align:start position:0% +which was under that board. I could make + + + align:start position:0% +which was under that board. I could make +those the columns of a matrix. Well, it + + align:start position:0% +those the columns of a matrix. Well, it + + + align:start position:0% +those the columns of a matrix. Well, it +would be the identity matrix. + + align:start position:0% +would be the identity matrix. + + + align:start position:0% +would be the identity matrix. +Then I would ask what's the null space + + align:start position:0% +Then I would ask what's the null space + + + align:start position:0% +Then I would ask what's the null space +of the identity matrix. And you would + + align:start position:0% +of the identity matrix. And you would + + + align:start position:0% +of the identity matrix. And you would +say it's only the zero vector. And I + + align:start position:0% +say it's only the zero vector. And I + + + align:start position:0% +say it's only the zero vector. And I +would say fine then the columns are + + align:start position:0% +would say fine then the columns are + + + align:start position:0% +would say fine then the columns are +independent. + + align:start position:0% +independent. + + + align:start position:0% +independent. +The only thing the identity times a + + align:start position:0% +The only thing the identity times a + + + align:start position:0% +The only thing the identity times a +vector giving zero the only ve vector + + align:start position:0% +vector giving zero the only ve vector + + + align:start position:0% +vector giving zero the only ve vector +that does that is zero. Okay. + + align:start position:0% +that does that is zero. Okay. + + + align:start position:0% +that does that is zero. Okay. +Now, that's not the only basis. Far from + + align:start position:0% +Now, that's not the only basis. Far from + + + align:start position:0% +Now, that's not the only basis. Far from +it. Tell me another basis. A second + + align:start position:0% +it. Tell me another basis. A second + + + align:start position:0% +it. Tell me another basis. A second +basis. Another basis. + + align:start position:0% + + + + align:start position:0% + +So, + + align:start position:0% +So, + + + align:start position:0% +So, +uh, give me well, I'll just start it + + align:start position:0% +uh, give me well, I'll just start it + + + align:start position:0% +uh, give me well, I'll just start it +out. One, one, two, + + align:start position:0% +out. One, one, two, + + + align:start position:0% +out. One, one, two, +uh, 225. + + align:start position:0% + + + + align:start position:0% + +Uh suppose I stop there. + + align:start position:0% +Uh suppose I stop there. + + + align:start position:0% +Uh suppose I stop there. +Have has that has that see has that have + + align:start position:0% +Have has that has that see has that have + + + align:start position:0% +Have has that has that see has that have +has that little bunch of vectors got the + + align:start position:0% +has that little bunch of vectors got the + + + align:start position:0% +has that little bunch of vectors got the +properties that I'm asking for in a + + align:start position:0% +properties that I'm asking for in a + + + align:start position:0% +properties that I'm asking for in a +basis for R3? We're we're looking for a + + align:start position:0% +basis for R3? We're we're looking for a + + + align:start position:0% +basis for R3? We're we're looking for a +basis for R3. Are they independent, + + align:start position:0% +basis for R3. Are they independent, + + + align:start position:0% +basis for R3. Are they independent, +those two column vectors? Yes. Do they + + align:start position:0% +those two column vectors? Yes. Do they + + + align:start position:0% +those two column vectors? Yes. Do they +span R3? + + align:start position:0% +span R3? + + + align:start position:0% +span R3? +No. Our feeling is no. Our feeling is + + align:start position:0% +No. Our feeling is no. Our feeling is + + + align:start position:0% +No. Our feeling is no. Our feeling is +no. Our feeling is that there's some + + align:start position:0% +no. Our feeling is that there's some + + + align:start position:0% +no. Our feeling is that there's some +vectors in R3 that are not combinations + + align:start position:0% +vectors in R3 that are not combinations + + + align:start position:0% +vectors in R3 that are not combinations +of those. Okay. So suppose I add in a I + + align:start position:0% +of those. Okay. So suppose I add in a I + + + align:start position:0% +of those. Okay. So suppose I add in a I +need another vector then because they + + align:start position:0% +need another vector then because they + + + align:start position:0% +need another vector then because they +these two don't span the space. Okay. + + align:start position:0% +these two don't span the space. Okay. + + + align:start position:0% +these two don't span the space. Okay. +Now it would be foolish for me to put in + + align:start position:0% +Now it would be foolish for me to put in + + + align:start position:0% +Now it would be foolish for me to put in +337 right as the third vector. + + align:start position:0% +337 right as the third vector. + + + align:start position:0% +337 right as the third vector. +That would be a goof because that if I + + align:start position:0% +That would be a goof because that if I + + + align:start position:0% +That would be a goof because that if I +put in 337, those vectors would be + + align:start position:0% +put in 337, those vectors would be + + + align:start position:0% +put in 337, those vectors would be +dependent, right? If I put in 337, it + + align:start position:0% +dependent, right? If I put in 337, it + + + align:start position:0% +dependent, right? If I put in 337, it +would be the sum of those two. It would + + align:start position:0% +would be the sum of those two. It would + + + align:start position:0% +would be the sum of those two. It would +lie in the same plane as those. It + + align:start position:0% +lie in the same plane as those. It + + + align:start position:0% +lie in the same plane as those. It +wouldn't be independent. I wouldn't I + + align:start position:0% +wouldn't be independent. I wouldn't I + + + align:start position:0% +wouldn't be independent. I wouldn't I +wouldn't I my attempt to create a basis + + align:start position:0% +wouldn't I my attempt to create a basis + + + align:start position:0% +wouldn't I my attempt to create a basis +would be dead. But if I take So what + + align:start position:0% +would be dead. But if I take So what + + + align:start position:0% +would be dead. But if I take So what +vector can I take? + + align:start position:0% +vector can I take? + + + align:start position:0% +vector can I take? +I can take any vector that's not in that + + align:start position:0% +I can take any vector that's not in that + + + align:start position:0% +I can take any vector that's not in that +plane. Let me try. I I hope that 338 + + align:start position:0% +plane. Let me try. I I hope that 338 + + + align:start position:0% +plane. Let me try. I I hope that 338 +would do it. + + align:start position:0% + + + + align:start position:0% + +At least it's not the sum of those two + + align:start position:0% +At least it's not the sum of those two + + + align:start position:0% +At least it's not the sum of those two +vectors. But I believe that's a basis. + + align:start position:0% +vectors. But I believe that's a basis. + + + align:start position:0% +vectors. But I believe that's a basis. +And what's the what's the test then for + + align:start position:0% +And what's the what's the test then for + + + align:start position:0% +And what's the what's the test then for +that to be a basis? What? Because I just + + align:start position:0% +that to be a basis? What? Because I just + + + align:start position:0% +that to be a basis? What? Because I just +picked those numbers. And if I had + + align:start position:0% +picked those numbers. And if I had + + + align:start position:0% +picked those numbers. And if I had +picked uh 57 + + align:start position:0% +picked uh 57 + + + align:start position:0% +picked uh 57 +minus14, + + align:start position:0% +minus14, + + + align:start position:0% +minus14, +how would we know do we have a basis or + + align:start position:0% +how would we know do we have a basis or + + + align:start position:0% +how would we know do we have a basis or +don't we? + + align:start position:0% +don't we? + + + align:start position:0% +don't we? +You would put them in the columns of a + + align:start position:0% +You would put them in the columns of a + + + align:start position:0% +You would put them in the columns of a +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +and you would do elimination row + + align:start position:0% +and you would do elimination row + + + align:start position:0% +and you would do elimination row +reduction and you would see do you get + + align:start position:0% +reduction and you would see do you get + + + align:start position:0% +reduction and you would see do you get +any + + align:start position:0% +any + + + align:start position:0% +any +free variables or are all the columns + + align:start position:0% +free variables or are all the columns + + + align:start position:0% +free variables or are all the columns +pivot columns? Well, now actually we + + align:start position:0% +pivot columns? Well, now actually we + + + align:start position:0% +pivot columns? Well, now actually we +have a square. The matrix would be 3x3. + + align:start position:0% +have a square. The matrix would be 3x3. + + + align:start position:0% +have a square. The matrix would be 3x3. +So, so what's the test on the matrix + + align:start position:0% +So, so what's the test on the matrix + + + align:start position:0% +So, so what's the test on the matrix +then? + + align:start position:0% + + + + align:start position:0% + +The matrix. So, so in this case when I + + align:start position:0% +The matrix. So, so in this case when I + + + align:start position:0% +The matrix. So, so in this case when I +when my space is R3 and I have three + + align:start position:0% +when my space is R3 and I have three + + + align:start position:0% +when my space is R3 and I have three +vectors, + + align:start position:0% +vectors, + + + align:start position:0% +vectors, +my matrix is square. + + align:start position:0% +my matrix is square. + + + align:start position:0% +my matrix is square. +And + + align:start position:0% +And + + + align:start position:0% +And +what am I asking about that matrix in + + align:start position:0% +what am I asking about that matrix in + + + align:start position:0% +what am I asking about that matrix in +order for those columns to be a basis? + + align:start position:0% +order for those columns to be a basis? + + + align:start position:0% +order for those columns to be a basis? +So the so in this in this for Rn + + align:start position:0% +So the so in this in this for Rn + + + align:start position:0% +So the so in this in this for Rn +if I have n vectors + + align:start position:0% + + + + align:start position:0% + +give a basis. + + align:start position:0% + + + + align:start position:0% + +If + + align:start position:0% +If + + + align:start position:0% +If +the n byn matrix + + align:start position:0% + + + + align:start position:0% + +with those columns + + align:start position:0% +with those columns + + + align:start position:0% +with those columns +with + + align:start position:0% +with + + + align:start position:0% +with +those columns + + align:start position:0% +those columns + + + align:start position:0% +those columns +is what + + align:start position:0% +is what + + + align:start position:0% +is what +what's what's the requirement on that + + align:start position:0% +what's what's the requirement on that + + + align:start position:0% +what's what's the requirement on that +matrix? + + align:start position:0% +matrix? + + + align:start position:0% +matrix? +Invertible. Right. Right. The matrix + + align:start position:0% +Invertible. Right. Right. The matrix + + + align:start position:0% +Invertible. Right. Right. The matrix +should be invertible for a square + + align:start position:0% +should be invertible for a square + + + align:start position:0% +should be invertible for a square +matrix. That's the that's the perfect + + align:start position:0% +matrix. That's the that's the perfect + + + align:start position:0% +matrix. That's the that's the perfect +answer is invertible. + + align:start position:0% + + + + align:start position:0% + +So that's when that's when the space is + + align:start position:0% +So that's when that's when the space is + + + align:start position:0% +So that's when that's when the space is +is is the whole space Rn. + + align:start position:0% + + + + align:start position:0% + +Let me let me be sure I I'm with you're + + align:start position:0% +Let me let me be sure I I'm with you're + + + align:start position:0% +Let me let me be sure I I'm with you're +with me here. Let me remove that. + + align:start position:0% +with me here. Let me remove that. + + + align:start position:0% +with me here. Let me remove that. +Are those two vectors a basis for + + align:start position:0% +Are those two vectors a basis for + + + align:start position:0% +Are those two vectors a basis for +any space at all? + + align:start position:0% +any space at all? + + + align:start position:0% +any space at all? +Is there a vector space that those + + align:start position:0% +Is there a vector space that those + + + align:start position:0% +Is there a vector space that those +really are a basis for? Those that pair + + align:start position:0% +really are a basis for? Those that pair + + + align:start position:0% +really are a basis for? Those that pair +of vectors, this guy and this one 112 + + align:start position:0% +of vectors, this guy and this one 112 + + + align:start position:0% +of vectors, this guy and this one 112 +and 225. Is there a space for which + + align:start position:0% +and 225. Is there a space for which + + + align:start position:0% +and 225. Is there a space for which +that's a basis? + + align:start position:0% +that's a basis? + + + align:start position:0% +that's a basis? +Sure, they're independent. + + align:start position:0% +Sure, they're independent. + + + align:start position:0% +Sure, they're independent. +So they satisfy the first requirement. + + align:start position:0% +So they satisfy the first requirement. + + + align:start position:0% +So they satisfy the first requirement. +So what space shall I take for them to + + align:start position:0% +So what space shall I take for them to + + + align:start position:0% +So what space shall I take for them to +be a basis of? What spaces will they be + + align:start position:0% +be a basis of? What spaces will they be + + + align:start position:0% +be a basis of? What spaces will they be +a basis for? + + align:start position:0% +a basis for? + + + align:start position:0% +a basis for? +the one they span they're combinations + + align:start position:0% +the one they span they're combinations + + + align:start position:0% +the one they span they're combinations +if it's a plane right it will be a plane + + align:start position:0% +if it's a plane right it will be a plane + + + align:start position:0% +if it's a plane right it will be a plane +inside R3 so if I take this vector 112 + + align:start position:0% +inside R3 so if I take this vector 112 + + + align:start position:0% +inside R3 so if I take this vector 112 +say it goes there and this vector 225 + + align:start position:0% +say it goes there and this vector 225 + + + align:start position:0% +say it goes there and this vector 225 +say it goes there those are a basis for + + align:start position:0% +say it goes there those are a basis for + + + align:start position:0% +say it goes there those are a basis for +because they span a plane + + align:start position:0% +because they span a plane + + + align:start position:0% +because they span a plane +and they're a basis for the plane + + align:start position:0% +and they're a basis for the plane + + + align:start position:0% +and they're a basis for the plane +because they're independent if I stick + + align:start position:0% +because they're independent if I stick + + + align:start position:0% +because they're independent if I stick +in some third guy like 337 which is in + + align:start position:0% +in some third guy like 337 which is in + + + align:start position:0% +in some third guy like 337 which is in +the plane + + align:start position:0% +the plane + + + align:start position:0% +the plane +Suppose I put in try to put in 337 then + + align:start position:0% +Suppose I put in try to put in 337 then + + + align:start position:0% +Suppose I put in try to put in 337 then +the three vectors would still span the + + align:start position:0% +the three vectors would still span the + + + align:start position:0% +the three vectors would still span the +plane but they wouldn't be a basis + + align:start position:0% +plane but they wouldn't be a basis + + + align:start position:0% +plane but they wouldn't be a basis +anymore because they're not independent + + align:start position:0% +anymore because they're not independent + + + align:start position:0% +anymore because they're not independent +anymore. Okay. So uh we're looking at + + align:start position:0% +anymore. Okay. So uh we're looking at + + + align:start position:0% +anymore. Okay. So uh we're looking at +the question of so again + + align:start position:0% +the question of so again + + + align:start position:0% +the question of so again +a the case with in independent columns + + align:start position:0% +a the case with in independent columns + + + align:start position:0% +a the case with in independent columns +is the case where the column vectors + + align:start position:0% +is the case where the column vectors + + + align:start position:0% +is the case where the column vectors +span the column space. They're + + align:start position:0% +span the column space. They're + + + align:start position:0% +span the column space. They're +independent so they're a basis for the + + align:start position:0% +independent so they're a basis for the + + + align:start position:0% +independent so they're a basis for the +column space. Okay. So now there's one + + align:start position:0% +column space. Okay. So now there's one + + + align:start position:0% +column space. Okay. So now there's one +bit of intuition. + + align:start position:0% +bit of intuition. + + + align:start position:0% +bit of intuition. +Let me go back to all of Rn. + + align:start position:0% +Let me go back to all of Rn. + + + align:start position:0% +Let me go back to all of Rn. +So where I put 338. + + align:start position:0% + + + + align:start position:0% + +Okay. The first message is that the + + align:start position:0% +Okay. The first message is that the + + + align:start position:0% +Okay. The first message is that the +basis is not unique. Right? There's + + align:start position:0% +basis is not unique. Right? There's + + + align:start position:0% +basis is not unique. Right? There's +zillions of bases. I take any invertible + + align:start position:0% +zillions of bases. I take any invertible + + + align:start position:0% +zillions of bases. I take any invertible +3x3 matrix. its columns are a basis for + + align:start position:0% +3x3 matrix. its columns are a basis for + + + align:start position:0% +3x3 matrix. its columns are a basis for +R3. + + align:start position:0% +R3. + + + align:start position:0% +R3. +The column space is R3. And if those if + + align:start position:0% +The column space is R3. And if those if + + + align:start position:0% +The column space is R3. And if those if +that matrix is invertible, those columns + + align:start position:0% +that matrix is invertible, those columns + + + align:start position:0% +that matrix is invertible, those columns +are independent. I've got a basis for + + align:start position:0% +are independent. I've got a basis for + + + align:start position:0% +are independent. I've got a basis for +R3. So there are many many bases, but + + align:start position:0% +R3. So there are many many bases, but + + + align:start position:0% +R3. So there are many many bases, but +there is something + + align:start position:0% +there is something + + + align:start position:0% +there is something +in common for all those bases. + + align:start position:0% +in common for all those bases. + + + align:start position:0% +in common for all those bases. +There's something that this basis shares + + align:start position:0% +There's something that this basis shares + + + align:start position:0% +There's something that this basis shares +with that basis and every other basis + + align:start position:0% +with that basis and every other basis + + + align:start position:0% +with that basis and every other basis +for R3. + + align:start position:0% +for R3. + + + align:start position:0% +for R3. +And what's that? + + align:start position:0% +And what's that? + + + align:start position:0% +And what's that? +Well, you saw it coming because when I + + align:start position:0% +Well, you saw it coming because when I + + + align:start position:0% +Well, you saw it coming because when I +stopped here + + align:start position:0% + + + + align:start position:0% + +and asked if that was a basis for R3, + + align:start position:0% +and asked if that was a basis for R3, + + + align:start position:0% +and asked if that was a basis for R3, +you said no. And I know that you said no + + align:start position:0% +you said no. And I know that you said no + + + align:start position:0% +you said no. And I know that you said no +because you knew there weren't enough + + align:start position:0% +because you knew there weren't enough + + + align:start position:0% +because you knew there weren't enough +vectors there. + + align:start position:0% +vectors there. + + + align:start position:0% +vectors there. +And the great fact is that there are + + align:start position:0% +And the great fact is that there are + + + align:start position:0% +And the great fact is that there are +many, many bases, but let me put in + + align:start position:0% +many, many bases, but let me put in + + + align:start position:0% +many, many bases, but let me put in +somebody else just for + + align:start position:0% + + + + align:start position:0% + +variety. + + align:start position:0% +variety. + + + align:start position:0% +variety. +There are many, many bases, but they all + + align:start position:0% +There are many, many bases, but they all + + + align:start position:0% +There are many, many bases, but they all +have the same number of vectors. + + align:start position:0% +have the same number of vectors. + + + align:start position:0% +have the same number of vectors. +If we're talking about the space R3, + + align:start position:0% +If we're talking about the space R3, + + + align:start position:0% +If we're talking about the space R3, +then that number of vectors is three. + + align:start position:0% +then that number of vectors is three. + + + align:start position:0% +then that number of vectors is three. +If we're talking about the space Rn, + + align:start position:0% +If we're talking about the space Rn, + + + align:start position:0% +If we're talking about the space Rn, +then that number of vectors is N. + + align:start position:0% +then that number of vectors is N. + + + align:start position:0% +then that number of vectors is N. +If we're talking about some other space, + + align:start position:0% + + + + align:start position:0% + +the column space of some matrix + + align:start position:0% +the column space of some matrix + + + align:start position:0% +the column space of some matrix +or the null space of some matrix or some + + align:start position:0% +or the null space of some matrix or some + + + align:start position:0% +or the null space of some matrix or some +other space that we haven't even thought + + align:start position:0% +other space that we haven't even thought + + + align:start position:0% +other space that we haven't even thought +of. + + align:start position:0% + + + + align:start position:0% + +Then that still is true that every basis + + align:start position:0% +Then that still is true that every basis + + + align:start position:0% +Then that still is true that every basis +that there are lots of bases but every + + align:start position:0% +that there are lots of bases but every + + + align:start position:0% +that there are lots of bases but every +basis has the same number of vectors. + + align:start position:0% +basis has the same number of vectors. + + + align:start position:0% +basis has the same number of vectors. +Let me write that great fact down. + + align:start position:0% +Let me write that great fact down. + + + align:start position:0% +Let me write that great fact down. +every + + align:start position:0% +every + + + align:start position:0% +every +basis we're we're given a space given + + align:start position:0% +basis we're we're given a space given + + + align:start position:0% +basis we're we're given a space given +a space + + align:start position:0% + + + + align:start position:0% + +R3 or Rn or some other column space of a + + align:start position:0% +R3 or Rn or some other column space of a + + + align:start position:0% +R3 or Rn or some other column space of a +matrix or the null space of a matrix or + + align:start position:0% +matrix or the null space of a matrix or + + + align:start position:0% +matrix or the null space of a matrix or +some other vector space then the great + + align:start position:0% +some other vector space then the great + + + align:start position:0% +some other vector space then the great +fact is that every basis + + align:start position:0% +fact is that every basis + + + align:start position:0% +fact is that every basis +for the for the space + + align:start position:0% + + + + align:start position:0% + +has + + align:start position:0% + + + + align:start position:0% + +the same + + align:start position:0% +the same + + + align:start position:0% +the same +number + + align:start position:0% +number + + + align:start position:0% +number +of vectors. + + align:start position:0% + + + + align:start position:0% + +If one basis has six vectors, then every + + align:start position:0% +If one basis has six vectors, then every + + + align:start position:0% +If one basis has six vectors, then every +other basis has six vectors. + + align:start position:0% +other basis has six vectors. + + + align:start position:0% +other basis has six vectors. +So that number six is telling me like + + align:start position:0% +So that number six is telling me like + + + align:start position:0% +So that number six is telling me like +it's telling me how big is the space. + + align:start position:0% +it's telling me how big is the space. + + + align:start position:0% +it's telling me how big is the space. +It's telling me how many vectors do I + + align:start position:0% +It's telling me how many vectors do I + + + align:start position:0% +It's telling me how many vectors do I +have to have to have a basis. + + align:start position:0% +have to have to have a basis. + + + align:start position:0% +have to have to have a basis. +And of course, we're seeing it this way. + + align:start position:0% +And of course, we're seeing it this way. + + + align:start position:0% +And of course, we're seeing it this way. +That number six, if we had seven vectors + + align:start position:0% +That number six, if we had seven vectors + + + align:start position:0% +That number six, if we had seven vectors +and we've got too many. If we have five + + align:start position:0% +and we've got too many. If we have five + + + align:start position:0% +and we've got too many. If we have five +vectors, we haven't got enough. + + align:start position:0% +vectors, we haven't got enough. + + + align:start position:0% +vectors, we haven't got enough. +Six is sort of like just right for + + align:start position:0% +Six is sort of like just right for + + + align:start position:0% +Six is sort of like just right for +whatever space that is. And what do we + + align:start position:0% +whatever space that is. And what do we + + + align:start position:0% +whatever space that is. And what do we +call that number? That number is now I'm + + align:start position:0% +call that number? That number is now I'm + + + align:start position:0% +call that number? That number is now I'm +ready for the last definition today. + + align:start position:0% +ready for the last definition today. + + + align:start position:0% +ready for the last definition today. +It's the dimension + + align:start position:0% +It's the dimension + + + align:start position:0% +It's the dimension +of that space. So every basis for a + + align:start position:0% +of that space. So every basis for a + + + align:start position:0% +of that space. So every basis for a +space has the same number of vectors in + + align:start position:0% +space has the same number of vectors in + + + align:start position:0% +space has the same number of vectors in +it. Not the same vectors, + + align:start position:0% +it. Not the same vectors, + + + align:start position:0% +it. Not the same vectors, +all sorts of bases, but the same number + + align:start position:0% +all sorts of bases, but the same number + + + align:start position:0% +all sorts of bases, but the same number +of vectors is always the same. And that + + align:start position:0% +of vectors is always the same. And that + + + align:start position:0% +of vectors is always the same. And that +number is the dimension. This is + + align:start position:0% +number is the dimension. This is + + + align:start position:0% +number is the dimension. This is +definition. + + align:start position:0% + + + + align:start position:0% + +This number is the dimension. + + align:start position:0% + + + + align:start position:0% + +of the space. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +let's do some examples + + align:start position:0% + + + + align:start position:0% + +because now we got definitions. Let me + + align:start position:0% +because now we got definitions. Let me + + + align:start position:0% +because now we got definitions. Let me +repeat the four things, the four words + + align:start position:0% +repeat the four things, the four words + + + align:start position:0% +repeat the four things, the four words +that have now got defined. Independence + + align:start position:0% +that have now got defined. Independence + + + align:start position:0% +that have now got defined. Independence +that looks at combinations not being + + align:start position:0% +that looks at combinations not being + + + align:start position:0% +that looks at combinations not being +zero. + + align:start position:0% +zero. + + + align:start position:0% +zero. +Spanning that looks at all the + + align:start position:0% +Spanning that looks at all the + + + align:start position:0% +Spanning that looks at all the +combinations. Basis that's the one that + + align:start position:0% +combinations. Basis that's the one that + + + align:start position:0% +combinations. Basis that's the one that +combines independence and spanning. And + + align:start position:0% +combines independence and spanning. And + + + align:start position:0% +combines independence and spanning. And +now we've got the idea of the dimension + + align:start position:0% +now we've got the idea of the dimension + + + align:start position:0% +now we've got the idea of the dimension +of a space. It's the number of vectors + + align:start position:0% +of a space. It's the number of vectors + + + align:start position:0% +of a space. It's the number of vectors +in any basis because all bases have the + + align:start position:0% +in any basis because all bases have the + + + align:start position:0% +in any basis because all bases have the +same number. Okay. Let's let's take + + align:start position:0% +same number. Okay. Let's let's take + + + align:start position:0% +same number. Okay. Let's let's take +examples. + + align:start position:0% +examples. + + + align:start position:0% +examples. +Suppose I take + + align:start position:0% +Suppose I take + + + align:start position:0% +Suppose I take +uh my space is examples. Now space is + + align:start position:0% +uh my space is examples. Now space is + + + align:start position:0% +uh my space is examples. Now space is +the say the column space of this matrix. + + align:start position:0% +the say the column space of this matrix. + + + align:start position:0% +the say the column space of this matrix. +Let me let me write down a matrix. + + align:start position:0% +Let me let me write down a matrix. + + + align:start position:0% +Let me let me write down a matrix. +1 one 2 one two and I'll just to make it + + align:start position:0% +1 one 2 one two and I'll just to make it + + + align:start position:0% +1 one 2 one two and I'll just to make it +clear I'll take the sum there 3 2 3 and + + align:start position:0% +clear I'll take the sum there 3 2 3 and + + + align:start position:0% +clear I'll take the sum there 3 2 3 and +let me take the sum of all oh let me put + + align:start position:0% +let me take the sum of all oh let me put + + + align:start position:0% +let me take the sum of all oh let me put +in one yeah I'll put in 11 one again + + align:start position:0% +in one yeah I'll put in 11 one again + + + align:start position:0% +in one yeah I'll put in 11 one again +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's four vectors + + align:start position:0% + + + + align:start position:0% + +okay do they span the column space of + + align:start position:0% +okay do they span the column space of + + + align:start position:0% +okay do they span the column space of +that matrix + + align:start position:0% +that matrix + + + align:start position:0% +that matrix +let me repeat do They span the column + + align:start position:0% +let me repeat do They span the column + + + align:start position:0% +let me repeat do They span the column +space of that matrix. Yes, by definition + + align:start position:0% +space of that matrix. Yes, by definition + + + align:start position:0% +space of that matrix. Yes, by definition +that's what the column space where it + + align:start position:0% +that's what the column space where it + + + align:start position:0% +that's what the column space where it +comes from. Are they a basis for the + + align:start position:0% +comes from. Are they a basis for the + + + align:start position:0% +comes from. Are they a basis for the +column space? Are they independent? + + align:start position:0% +column space? Are they independent? + + + align:start position:0% +column space? Are they independent? +No, they're not independent. There's + + align:start position:0% +No, they're not independent. There's + + + align:start position:0% +No, they're not independent. There's +something in that null space. + + align:start position:0% +something in that null space. + + + align:start position:0% +something in that null space. +Maybe we can. So, let's look at the null + + align:start position:0% +Maybe we can. So, let's look at the null + + + align:start position:0% +Maybe we can. So, let's look at the null +space of the matrix. + + align:start position:0% +space of the matrix. + + + align:start position:0% +space of the matrix. +Tell me a vector that's in the null + + align:start position:0% +Tell me a vector that's in the null + + + align:start position:0% +Tell me a vector that's in the null +space of that matrix. + + align:start position:0% +space of that matrix. + + + align:start position:0% +space of that matrix. +So I'm looking for some vector that + + align:start position:0% +So I'm looking for some vector that + + + align:start position:0% +So I'm looking for some vector that +combines those columns and produces the + + align:start position:0% +combines those columns and produces the + + + align:start position:0% +combines those columns and produces the +zero column. + + align:start position:0% +zero column. + + + align:start position:0% +zero column. +Or in other words, I'm looking for + + align:start position:0% +Or in other words, I'm looking for + + + align:start position:0% +Or in other words, I'm looking for +solutions to ax= z. So so tell me a + + align:start position:0% +solutions to ax= z. So so tell me a + + + align:start position:0% +solutions to ax= z. So so tell me a +vector in the null space. + + align:start position:0% +vector in the null space. + + + align:start position:0% +vector in the null space. +Maybe well this was this column was that + + align:start position:0% +Maybe well this was this column was that + + + align:start position:0% +Maybe well this was this column was that +one plus that one. So maybe if I have + + align:start position:0% +one plus that one. So maybe if I have + + + align:start position:0% +one plus that one. So maybe if I have +one of those and minus one of those that + + align:start position:0% +one of those and minus one of those that + + + align:start position:0% +one of those and minus one of those that +would be a vector in the null space. + + align:start position:0% +would be a vector in the null space. + + + align:start position:0% +would be a vector in the null space. +So you've already told me now are those + + align:start position:0% +So you've already told me now are those + + + align:start position:0% +So you've already told me now are those +vectors independent? The answer is those + + align:start position:0% +vectors independent? The answer is those + + + align:start position:0% +vectors independent? The answer is those +column vectors. The answer is no. Right? + + align:start position:0% +column vectors. The answer is no. Right? + + + align:start position:0% +column vectors. The answer is no. Right? +They're not independent because ah you + + align:start position:0% +They're not independent because ah you + + + align:start position:0% +They're not independent because ah you +knew they weren't independent anyway. + + align:start position:0% +knew they weren't independent anyway. + + + align:start position:0% +knew they weren't independent anyway. +Minus one of this minus one of this plus + + align:start position:0% +Minus one of this minus one of this plus + + + align:start position:0% +Minus one of this minus one of this plus +one of this zero of that is the zero + + align:start position:0% +one of this zero of that is the zero + + + align:start position:0% +one of this zero of that is the zero +vector. Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So they're not independent. They + + align:start position:0% +Okay. So they're not independent. They + + + align:start position:0% +Okay. So they're not independent. They +span but they're not independent. Tell + + align:start position:0% +span but they're not independent. Tell + + + align:start position:0% +span but they're not independent. Tell +me + + align:start position:0% +me + + + align:start position:0% +me +a basis + + align:start position:0% +a basis + + + align:start position:0% +a basis +for that column space. + + align:start position:0% +for that column space. + + + align:start position:0% +for that column space. +What's a basis for the column space? + + align:start position:0% +What's a basis for the column space? + + + align:start position:0% +What's a basis for the column space? +These are all the questions that the + + align:start position:0% +These are all the questions that the + + + align:start position:0% +These are all the questions that the +homework asks, the quizzes asked, the + + align:start position:0% +homework asks, the quizzes asked, the + + + align:start position:0% +homework asks, the quizzes asked, the +final exam will ask. Find a basis for + + align:start position:0% +final exam will ask. Find a basis for + + + align:start position:0% +final exam will ask. Find a basis for +the column space of this matrix. + + align:start position:0% +the column space of this matrix. + + + align:start position:0% +the column space of this matrix. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now, there's many answers, but give me + + align:start position:0% +Now, there's many answers, but give me + + + align:start position:0% +Now, there's many answers, but give me +the most natural answer. + + align:start position:0% +the most natural answer. + + + align:start position:0% +the most natural answer. +columns + + align:start position:0% +columns + + + align:start position:0% +columns +one and two. Columns one and two. That's + + align:start position:0% +one and two. Columns one and two. That's + + + align:start position:0% +one and two. Columns one and two. That's +the natural answer. Those are the pivot + + align:start position:0% +the natural answer. Those are the pivot + + + align:start position:0% +the natural answer. Those are the pivot +columns because I mean we we begin + + align:start position:0% +columns because I mean we we begin + + + align:start position:0% +columns because I mean we we begin +systematically. We look at the first + + align:start position:0% +systematically. We look at the first + + + align:start position:0% +systematically. We look at the first +column. It's okay. We can put that in + + align:start position:0% +column. It's okay. We can put that in + + + align:start position:0% +column. It's okay. We can put that in +the basis. We look at the second column. + + align:start position:0% +the basis. We look at the second column. + + + align:start position:0% +the basis. We look at the second column. +It's okay. We can put that in the basis. + + align:start position:0% +It's okay. We can put that in the basis. + + + align:start position:0% +It's okay. We can put that in the basis. +The third column we can't put in the + + align:start position:0% +The third column we can't put in the + + + align:start position:0% +The third column we can't put in the +basis. The fourth column we + + align:start position:0% +basis. The fourth column we + + + align:start position:0% +basis. The fourth column we +can't again. So the rank of the matrix + + align:start position:0% +can't again. So the rank of the matrix + + + align:start position:0% +can't again. So the rank of the matrix +is + + align:start position:0% +is + + + align:start position:0% +is +what's the rank of our matrix? Two. Two. + + align:start position:0% +what's the rank of our matrix? Two. Two. + + + align:start position:0% +what's the rank of our matrix? Two. Two. +And and now that rank is also we now + + align:start position:0% +And and now that rank is also we now + + + align:start position:0% +And and now that rank is also we now +have another word. We we have a great + + align:start position:0% +have another word. We we have a great + + + align:start position:0% +have another word. We we have a great +theorem here. The rank of A + + align:start position:0% + + + + align:start position:0% + +that rank R + + align:start position:0% +that rank R + + + align:start position:0% +that rank R +is the number of pivot columns + + align:start position:0% + + + + align:start position:0% + +and it's also + + align:start position:0% +and it's also + + + align:start position:0% +and it's also +well so now please use my new word + + align:start position:0% + + + + align:start position:0% + +this it's the number two of course two + + align:start position:0% + + + + align:start position:0% + +is the rank of my matrix. It's the + + align:start position:0% +is the rank of my matrix. It's the + + + align:start position:0% +is the rank of my matrix. It's the +number of pivot columns. Those pivot + + align:start position:0% +number of pivot columns. Those pivot + + + align:start position:0% +number of pivot columns. Those pivot +columns form a basis of course. So + + align:start position:0% +columns form a basis of course. So + + + align:start position:0% +columns form a basis of course. So +what's two? + + align:start position:0% +what's two? + + + align:start position:0% +what's two? +It's the dimension. + + align:start position:0% + + + + align:start position:0% + +The rank of A, the number of pivot + + align:start position:0% +The rank of A, the number of pivot + + + align:start position:0% +The rank of A, the number of pivot +columns is the dimension + + align:start position:0% +columns is the dimension + + + align:start position:0% +columns is the dimension +of + + align:start position:0% +of + + + align:start position:0% +of +the column space. Of + + align:start position:0% + + + + align:start position:0% + +course, you say it had to be right. But + + align:start position:0% +course, you say it had to be right. But + + + align:start position:0% +course, you say it had to be right. But +just watch look for one moment at the + + align:start position:0% +just watch look for one moment at the + + + align:start position:0% +just watch look for one moment at the +the language, the way the English words + + align:start position:0% +the language, the way the English words + + + align:start position:0% +the language, the way the English words +get involved here. I take the rank of a + + align:start position:0% +get involved here. I take the rank of a + + + align:start position:0% +get involved here. I take the rank of a +matrix. + + align:start position:0% +matrix. + + + align:start position:0% +matrix. +the rank of a matrix. + + align:start position:0% +the rank of a matrix. + + + align:start position:0% +the rank of a matrix. +It's a number of columns and it's the + + align:start position:0% +It's a number of columns and it's the + + + align:start position:0% +It's a number of columns and it's the +dimension of + + align:start position:0% +dimension of + + + align:start position:0% +dimension of +not the dimension of the matrix. That's + + align:start position:0% +not the dimension of the matrix. That's + + + align:start position:0% +not the dimension of the matrix. That's +what I want to say. It's the dimension + + align:start position:0% +what I want to say. It's the dimension + + + align:start position:0% +what I want to say. It's the dimension +of a space, a subspace, the column + + align:start position:0% +of a space, a subspace, the column + + + align:start position:0% +of a space, a subspace, the column +space. + + align:start position:0% +space. + + + align:start position:0% +space. +Do do you see I I don't take the + + align:start position:0% +Do do you see I I don't take the + + + align:start position:0% +Do do you see I I don't take the +dimension of A. That's not what I want. + + align:start position:0% +dimension of A. That's not what I want. + + + align:start position:0% +dimension of A. That's not what I want. +I'm looking for the dimension of the + + align:start position:0% +I'm looking for the dimension of the + + + align:start position:0% +I'm looking for the dimension of the +column space of A. If you use those + + align:start position:0% +column space of A. If you use those + + + align:start position:0% +column space of A. If you use those +words right, it shows you got the idea + + align:start position:0% +words right, it shows you got the idea + + + align:start position:0% +words right, it shows you got the idea +right. + + align:start position:0% +right. + + + align:start position:0% +right. +Similarly, here I don't talk about the + + align:start position:0% +Similarly, here I don't talk about the + + + align:start position:0% +Similarly, here I don't talk about the +rank of a subspace. + + align:start position:0% +rank of a subspace. + + + align:start position:0% +rank of a subspace. +It's a matrix that has a rank. I talk + + align:start position:0% +It's a matrix that has a rank. I talk + + + align:start position:0% +It's a matrix that has a rank. I talk +about the rank of a matrix. And it the + + align:start position:0% +about the rank of a matrix. And it the + + + align:start position:0% +about the rank of a matrix. And it the +beauty is that these definitions just + + align:start position:0% +beauty is that these definitions just + + + align:start position:0% +beauty is that these definitions just +merge so that the rank of a matrix is + + align:start position:0% +merge so that the rank of a matrix is + + + align:start position:0% +merge so that the rank of a matrix is +the dimension of its column space. And + + align:start position:0% +the dimension of its column space. And + + + align:start position:0% +the dimension of its column space. And +in this example, it's two. And then the + + align:start position:0% +in this example, it's two. And then the + + + align:start position:0% +in this example, it's two. And then the +further question is what's a basis? And + + align:start position:0% +further question is what's a basis? And + + + align:start position:0% +further question is what's a basis? And +the first two columns are a basis. Tell + + align:start position:0% +the first two columns are a basis. Tell + + + align:start position:0% +the first two columns are a basis. Tell +me another basis. Another basis for the + + align:start position:0% +me another basis. Another basis for the + + + align:start position:0% +me another basis. Another basis for the +column space. You see, I just keep + + align:start position:0% +column space. You see, I just keep + + + align:start position:0% +column space. You see, I just keep +hammering away. I apologize, but it's I + + align:start position:0% +hammering away. I apologize, but it's I + + + align:start position:0% +hammering away. I apologize, but it's I +have to be sure you have the idea of + + align:start position:0% +have to be sure you have the idea of + + + align:start position:0% +have to be sure you have the idea of +basis. Tell me another basis for the + + align:start position:0% +basis. Tell me another basis for the + + + align:start position:0% +basis. Tell me another basis for the +column space. + + align:start position:0% +column space. + + + align:start position:0% +column space. +Well, you could take columns one and + + align:start position:0% +Well, you could take columns one and + + + align:start position:0% +Well, you could take columns one and +three. + + align:start position:0% +three. + + + align:start position:0% +three. +That would be a basis for the column + + align:start position:0% +That would be a basis for the column + + + align:start position:0% +That would be a basis for the column +space. or columns two and three would be + + align:start position:0% +space. or columns two and three would be + + + align:start position:0% +space. or columns two and three would be +a basis or columns two and four or me + + align:start position:0% +a basis or columns two and four or me + + + align:start position:0% +a basis or columns two and four or me +another basis that's not made out of + + align:start position:0% +another basis that's not made out of + + + align:start position:0% +another basis that's not made out of +those columns at all. + + align:start position:0% + + + + align:start position:0% + +So well I guess I'm giving you + + align:start position:0% +So well I guess I'm giving you + + + align:start position:0% +So well I guess I'm giving you +infinitely many possibilities so I can't + + align:start position:0% +infinitely many possibilities so I can't + + + align:start position:0% +infinitely many possibilities so I can't +expect a unanimous answer here. I tell + + align:start position:0% +expect a unanimous answer here. I tell + + + align:start position:0% +expect a unanimous answer here. I tell +you let's look at another basis though. + + align:start position:0% +you let's look at another basis though. + + + align:start position:0% +you let's look at another basis though. +I'll just because it's only one out of + + align:start position:0% +I'll just because it's only one out of + + + align:start position:0% +I'll just because it's only one out of +zillions. I'm going to put it down and + + align:start position:0% +zillions. I'm going to put it down and + + + align:start position:0% +zillions. I'm going to put it down and +I'm going to erase it. Another basis for + + align:start position:0% +I'm going to erase it. Another basis for + + + align:start position:0% +I'm going to erase it. Another basis for +the column space + + align:start position:0% +the column space + + + align:start position:0% +the column space +would be + + align:start position:0% +would be + + + align:start position:0% +would be +uh let's see I'll put in some things + + align:start position:0% +uh let's see I'll put in some things + + + align:start position:0% +uh let's see I'll put in some things +that are not there. say, "Oh, well, just + + align:start position:0% +that are not there. say, "Oh, well, just + + + align:start position:0% +that are not there. say, "Oh, well, just +to make it my life easy, 222. That's in + + align:start position:0% +to make it my life easy, 222. That's in + + + align:start position:0% +to make it my life easy, 222. That's in +the column space." + + align:start position:0% +the column space." + + + align:start position:0% +the column space." +And uh that was sort of obvious. Let me + + align:start position:0% +And uh that was sort of obvious. Let me + + + align:start position:0% +And uh that was sort of obvious. Let me +take the sum of those say 6 46 + + align:start position:0% + + + + align:start position:0% + +or the sum of all the columns 757. Why + + align:start position:0% +or the sum of all the columns 757. Why + + + align:start position:0% +or the sum of all the columns 757. Why +not? That's in the column space. + + align:start position:0% +not? That's in the column space. + + + align:start position:0% +not? That's in the column space. +Those are independent. + + align:start position:0% +Those are independent. + + + align:start position:0% +Those are independent. +And I've got the number right. I've got + + align:start position:0% +And I've got the number right. I've got + + + align:start position:0% +And I've got the number right. I've got +two. Actually, this is a key point. + + align:start position:0% + + + + align:start position:0% + +If you know the dimension of the space + + align:start position:0% +If you know the dimension of the space + + + align:start position:0% +If you know the dimension of the space +you're working with, and we know that + + align:start position:0% +you're working with, and we know that + + + align:start position:0% +you're working with, and we know that +this column, we know that the dimension + + align:start position:0% +this column, we know that the dimension + + + align:start position:0% +this column, we know that the dimension +dime the dimension of the column space + + align:start position:0% +dime the dimension of the column space + + + align:start position:0% +dime the dimension of the column space +is two. + + align:start position:0% + + + + align:start position:0% + +If you know the the dimension then then + + align:start position:0% +If you know the the dimension then then + + + align:start position:0% +If you know the the dimension then then +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and we have a couple of vectors that are + + align:start position:0% +and we have a couple of vectors that are + + + align:start position:0% +and we have a couple of vectors that are +independent + + align:start position:0% +independent + + + align:start position:0% +independent +they'll automatically be a basis. If + + align:start position:0% +they'll automatically be a basis. If + + + align:start position:0% +they'll automatically be a basis. If +we've got the number of vectors right, + + align:start position:0% +we've got the number of vectors right, + + + align:start position:0% +we've got the number of vectors right, +two vectors in this case, then if + + align:start position:0% +two vectors in this case, then if + + + align:start position:0% +two vectors in this case, then if +they're independent, they can't help but + + align:start position:0% +they're independent, they can't help but + + + align:start position:0% +they're independent, they can't help but +span the space because if they didn't + + align:start position:0% +span the space because if they didn't + + + align:start position:0% +span the space because if they didn't +span the space, there'd be a third guy + + align:start position:0% +span the space, there'd be a third guy + + + align:start position:0% +span the space, there'd be a third guy +to help span the space. + + align:start position:0% +to help span the space. + + + align:start position:0% +to help span the space. +But it couldn't be independent. So it it + + align:start position:0% +But it couldn't be independent. So it it + + + align:start position:0% +But it couldn't be independent. So it it +just has to be + + align:start position:0% +just has to be + + + align:start position:0% +just has to be +independent if we've got the numbers + + align:start position:0% +independent if we've got the numbers + + + align:start position:0% +independent if we've got the numbers +right + + align:start position:0% +right + + + align:start position:0% +right +and they span. Okay, very good. So you + + align:start position:0% +and they span. Okay, very good. So you + + + align:start position:0% +and they span. Okay, very good. So you +got the dimension of a space. So this + + align:start position:0% +got the dimension of a space. So this + + + align:start position:0% +got the dimension of a space. So this +was another basis that I just invented. + + align:start position:0% +was another basis that I just invented. + + + align:start position:0% +was another basis that I just invented. +Okay. Now, + + align:start position:0% +Okay. Now, + + + align:start position:0% +Okay. Now, +now I get to ask you about the null + + align:start position:0% +now I get to ask you about the null + + + align:start position:0% +now I get to ask you about the null +space. + + align:start position:0% +space. + + + align:start position:0% +space. +What's the dimension of the null space? + + align:start position:0% +What's the dimension of the null space? + + + align:start position:0% +What's the dimension of the null space? +So we we got a great fact there. The + + align:start position:0% +So we we got a great fact there. The + + + align:start position:0% +So we we got a great fact there. The +dimension + + align:start position:0% +dimension + + + align:start position:0% +dimension +of the column space is the rank. + + align:start position:0% +of the column space is the rank. + + + align:start position:0% +of the column space is the rank. +Now I want to ask you about the null + + align:start position:0% +Now I want to ask you about the null + + + align:start position:0% +Now I want to ask you about the null +space. That's the other + + align:start position:0% +space. That's the other + + + align:start position:0% +space. That's the other +part of the lecture and it'll go on to + + align:start position:0% +part of the lecture and it'll go on to + + + align:start position:0% +part of the lecture and it'll go on to +the next lecture. + + align:start position:0% +the next lecture. + + + align:start position:0% +the next lecture. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So we know the dimension of the column + + align:start position:0% +So we know the dimension of the column + + + align:start position:0% +So we know the dimension of the column +space is two. The rank. What about the + + align:start position:0% +space is two. The rank. What about the + + + align:start position:0% +space is two. The rank. What about the +null space? This is a vector in the null + + align:start position:0% +null space? This is a vector in the null + + + align:start position:0% +null space? This is a vector in the null +space. Are there other vectors in the + + align:start position:0% +space. Are there other vectors in the + + + align:start position:0% +space. Are there other vectors in the +null space? + + align:start position:0% +null space? + + + align:start position:0% +null space? +Yes or no? Yes. So this isn't a basis + + align:start position:0% +Yes or no? Yes. So this isn't a basis + + + align:start position:0% +Yes or no? Yes. So this isn't a basis +because it's doesn't span. Right? + + align:start position:0% +because it's doesn't span. Right? + + + align:start position:0% +because it's doesn't span. Right? +There's more in the null space than + + align:start position:0% +There's more in the null space than + + + align:start position:0% +There's more in the null space than +we've got so far. I need another vector + + align:start position:0% +we've got so far. I need another vector + + + align:start position:0% +we've got so far. I need another vector +at least. So tell me another vector in + + align:start position:0% +at least. So tell me another vector in + + + align:start position:0% +at least. So tell me another vector in +the null space. + + align:start position:0% +the null space. + + + align:start position:0% +the null space. +Well, the natural choice, the choice you + + align:start position:0% +Well, the natural choice, the choice you + + + align:start position:0% +Well, the natural choice, the choice you +naturally think of is I'm going on to + + align:start position:0% +naturally think of is I'm going on to + + + align:start position:0% +naturally think of is I'm going on to +the fourth column. + + align:start position:0% +the fourth column. + + + align:start position:0% +the fourth column. +I'm letting that free variable be a one + + align:start position:0% +I'm letting that free variable be a one + + + align:start position:0% +I'm letting that free variable be a one +and that free variable be a zero. And + + align:start position:0% +and that free variable be a zero. And + + + align:start position:0% +and that free variable be a zero. And +I'm asking, is that fourth column a + + align:start position:0% +I'm asking, is that fourth column a + + + align:start position:0% +I'm asking, is that fourth column a +combination of my pivot columns? Yes, it + + align:start position:0% +combination of my pivot columns? Yes, it + + + align:start position:0% +combination of my pivot columns? Yes, it +is. And it's + + align:start position:0% +is. And it's + + + align:start position:0% +is. And it's +that will do. + + align:start position:0% + + + + align:start position:0% + +So what I've written there are actually + + align:start position:0% +So what I've written there are actually + + + align:start position:0% +So what I've written there are actually +the two special solutions, right? I took + + align:start position:0% +the two special solutions, right? I took + + + align:start position:0% +the two special solutions, right? I took +the two free variables free and free. + + align:start position:0% +the two free variables free and free. + + + align:start position:0% +the two free variables free and free. +I gave them the values one zero or 01. I + + align:start position:0% +I gave them the values one zero or 01. I + + + align:start position:0% +I gave them the values one zero or 01. I +figured out the rest. + + align:start position:0% +figured out the rest. + + + align:start position:0% +figured out the rest. +So do do you see? Let me just say it in + + align:start position:0% +So do do you see? Let me just say it in + + + align:start position:0% +So do do you see? Let me just say it in +words. this vector, these vectors in the + + align:start position:0% +words. this vector, these vectors in the + + + align:start position:0% +words. this vector, these vectors in the +null space are telling me, they're + + align:start position:0% +null space are telling me, they're + + + align:start position:0% +null space are telling me, they're +telling me the combinations of the + + align:start position:0% +telling me the combinations of the + + + align:start position:0% +telling me the combinations of the +columns that give zero. They're telling + + align:start position:0% +columns that give zero. They're telling + + + align:start position:0% +columns that give zero. They're telling +me + + align:start position:0% +me + + + align:start position:0% +me +in what way the the columns are + + align:start position:0% +in what way the the columns are + + + align:start position:0% +in what way the the columns are +dependent. That's what the null space is + + align:start position:0% +dependent. That's what the null space is + + + align:start position:0% +dependent. That's what the null space is +doing. Have I got enough now? + + align:start position:0% +doing. Have I got enough now? + + + align:start position:0% +doing. Have I got enough now? +And what's the null space? Now, we have + + align:start position:0% +And what's the null space? Now, we have + + + align:start position:0% +And what's the null space? Now, we have +to think about the null space. + + align:start position:0% +to think about the null space. + + + align:start position:0% +to think about the null space. +These are two vectors in the null space. + + align:start position:0% +These are two vectors in the null space. + + + align:start position:0% +These are two vectors in the null space. +They're independent. Are they a basis + + align:start position:0% +They're independent. Are they a basis + + + align:start position:0% +They're independent. Are they a basis +for the null space? What's the dimension + + align:start position:0% +for the null space? What's the dimension + + + align:start position:0% +for the null space? What's the dimension +of the null space? You see that those + + align:start position:0% +of the null space? You see that those + + + align:start position:0% +of the null space? You see that those +questions just keep coming up all the + + align:start position:0% +questions just keep coming up all the + + + align:start position:0% +questions just keep coming up all the +time. + + align:start position:0% +time. + + + align:start position:0% +time. +Are they a basis for the null space? You + + align:start position:0% +Are they a basis for the null space? You + + + align:start position:0% +Are they a basis for the null space? You +can tell me the answer even though we + + align:start position:0% +can tell me the answer even though we + + + align:start position:0% +can tell me the answer even though we +haven't written out a proof of that. Can + + align:start position:0% +haven't written out a proof of that. Can + + + align:start position:0% +haven't written out a proof of that. Can +you yes or no? Do these two special + + align:start position:0% +you yes or no? Do these two special + + + align:start position:0% +you yes or no? Do these two special +solutions form a basis for the null + + align:start position:0% +solutions form a basis for the null + + + align:start position:0% +solutions form a basis for the null +space? In other words, does the null + + align:start position:0% +space? In other words, does the null + + + align:start position:0% +space? In other words, does the null +space consist of all combinations of + + align:start position:0% +space consist of all combinations of + + + align:start position:0% +space consist of all combinations of +those two guys? Yes or no? Yes. Yes. + + align:start position:0% +those two guys? Yes or no? Yes. Yes. + + + align:start position:0% +those two guys? Yes or no? Yes. Yes. +The null space is two-dimensional. The + + align:start position:0% +The null space is two-dimensional. The + + + align:start position:0% +The null space is two-dimensional. The +null space, the dimension of the null + + align:start position:0% +null space, the dimension of the null + + + align:start position:0% +null space, the dimension of the null +space is the number of free variables. + + align:start position:0% +space is the number of free variables. + + + align:start position:0% +space is the number of free variables. +So the dimension of the null space + + align:start position:0% + + + + align:start position:0% + +is the number of free variables + + align:start position:0% + + + + align:start position:0% + +and at the last second give me the + + align:start position:0% +and at the last second give me the + + + align:start position:0% +and at the last second give me the +formula. + + align:start position:0% +formula. + + + align:start position:0% +formula. +This is then the key formula that we + + align:start position:0% +This is then the key formula that we + + + align:start position:0% +This is then the key formula that we +know how many free variables are there + + align:start position:0% +know how many free variables are there + + + align:start position:0% +know how many free variables are there +in terms of r the rank m the number of + + align:start position:0% +in terms of r the rank m the number of + + + align:start position:0% +in terms of r the rank m the number of +rows n the number of columns + + align:start position:0% +rows n the number of columns + + + align:start position:0% +rows n the number of columns +what do we get we have n columns + + align:start position:0% +what do we get we have n columns + + + align:start position:0% +what do we get we have n columns +r of them are pivot columns so n minus r + + align:start position:0% +r of them are pivot columns so n minus r + + + align:start position:0% +r of them are pivot columns so n minus r +is the number of free columns free + + align:start position:0% +is the number of free columns free + + + align:start position:0% +is the number of free columns free +variables and now it's the dimension of + + align:start position:0% +variables and now it's the dimension of + + + align:start position:0% +variables and now it's the dimension of +the null space. Okay, that's great. + + align:start position:0% +the null space. Okay, that's great. + + + align:start position:0% +the null space. Okay, that's great. +That's the key spaces, their bases, and + + align:start position:0% +That's the key spaces, their bases, and + + + align:start position:0% +That's the key spaces, their bases, and +their dimensions. Thanks, \ No newline at end of file diff --git a/yvatNaV6Bog.txt b/yvatNaV6Bog.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1524436c706d4adb2f121024c97bf3a672faee1 --- /dev/null +++ b/yvatNaV6Bog.txt @@ -0,0 +1,2566 @@ +PROFESSOR: All +right, so lecture 11 + +was about generic +rigidity of linkages. + +So we've got bars and vertices +connected together in a graph. + +And generically, the +graph is all that matters. + +And we characterize in two +ways, Henneberg construction + +and Laman when graphs +are generically rigid. + +And in particular, there +was this pebble algorithm + +that was supposed to tell +you in polynomial time + +whether you're a graph +was Laman or not. + +And everyone pretty much asked +about this, about the details, + +including myself when +I watched it like, huh, + +that seems a little sketchy. + +So I thought I'd spend +most of today going + +through how that +algorithm works exactly + +and also why it's correct, which +is definitely not obviously. + +It vaguely feels correct, but +we'll see why it actually is. + +Remember Laman's Theorem, +Laman characterization + +is that your graph is +generically rigid if and only + +if every subgraph-- let's +say every k vertices induces + +at most to 2k minus 3 edges. + +That's part one. + +And you also need +that the number + +of edges overall in +the graph is 2n minus 3 + +where n is the total +number vertices. + +So this was just the +degree of freedom count. + +You have 2n degrees of freedom +for every vertex minus 3 + +for the rigid motions, two +translations, one rotation. + +So that's the number of +edges you should have total. + +Sorry. + +This is for minimally +generically rigid. + +And then to make it +balance, you want + +to guarantee that every +k vertices doesn't + +have too many edges. + +Because if it has +too many edges, + +there'd be too few +somewhere else. + +This part would be +overbrace, some other part + +would be underbrace, +and you'd be flexible. + +That's the intuition. + +And so the tricky +part comes down + +to how do you check whether +every k vertices induces + +2k minus 3 edges because they're +exponentially many choices. + +There's 2 to the n different +choices of subsets or vertices. + +For each of them, +you'd have to check. + +That's no good. + +So the algorithm +wants to check this. + +And I'm going to +call this property + +the 2k minus 3 property. + +And we're going to warm up +with a simpler problem, which + +is to check to the 2k +property without the minus 3. + +So 2k property is +just every k vertices + +induce at most 2k edges. + +So this'll be a little +easier to think about, + +more or less the same, a +lot easier to argue about. + +And then we'll see how +to modify the algorithm + +to check the 2k +minus 3 property. + +Was the property clear and +in particular inducing? + +Inducing means that you +have some set of vertices, + +and there's the rest of the +vertices, n minus k of them. + +You only look at edges where +both endpoints are in the set, + +both of them are +among the k vertices. + +So you ignore vertices that have +one end in k and the other end + +outside. + +And you ignore, obviously, edges +that have both ends outside. + +Just count these guys. + +So how do we do this? + +Give you the algorithm. + +Actually, let me first give +you the idea of the algorithm + +before we go to the +actual algorithm. + +And this is review, +but pretty soon we'll + +get to stuff that wasn't +covered in lecture. + +So the idea is every vertex +has two pebbles inside of it. + +I'll draw as two red dots. + +And they can cover +incident edges. + +So they can't move very far. + +They have to stay +basically on the inside + +or on the boundary +of the vertex. + +That's how I'm going to draw it. + +Each pebble can cover +one incident edge. + +So for example, +there's a little graph. + +I could take-- +let's maybe I leave + +one of the pebbles +in the middle. + +I can move one of the pebbles +to cover one of the edges. + +So I'll put it this +intersection to denote + +it's covering this edge, but it +still belongs to this vertex. + +Pebbles cannot change vertices. + +They have to stay local. + +These two pebbles could +just stay where they are. + +Here, we could put +one pebble here, + +another pebble there, one +pebble here, one pebble here. + +This is what I call +a pebble cover cause + +every edge is covered +by some pebble. + +That's the goal in a pebble +cover is to cover every edge. + +You need to cover it once. + +And the pebbles can either cover +an edge or they can be free. + +Free if they're just +hanging out in the inside + +here not being +used for anything. + +So our goal is to +find pebble covers. + +But the first claim, why do +I care about pebble covers, + +I claimed that +having a pebble cover + +is equivalent to +the 2k property. + +So that's what I want to show. + +So let's start with that. + +This is why +everything is working. + +A graph has a 2k property if and +only if it has a pebble cover. + +So that's why we care about +these pebble coverings. + +And this is actually +pretty easy to prove + +and gives a lot of intuition +for why everything works here. + +So let's start with +the left direction. + +So suppose I have +a pebble cover. + +Suppose somehow I've +achieved this property, + +covering all the edges, using +only two pebbles per vertex. + +I claim that we then +satisfy the 2k property. + +2k property says you +take any key vertices, + +you induce at most +two key edges. + +So let's consider k vertices. + +Someone chooses k vertices. + +doesn't matter which. + +It should hold for all +of them, for all choices. + +So we've got a k vertices here. + +n minus k vertices remaining. + +We claim that the number +of edges induced by those k + +vertices is at most 2k. + +So look at one of these +edges that's wholly inside, + +that's induced by +these k vertices. + +I claim, well, that edge +must be covered by a pebble. + +Which pebble? + +Well, either this one or +one on the other side. + +But the point is it +is covered by a pebble + +among these vertices. + +My concern is, well, maybe you +worry about an edge like this. + +Or, maybe you worry +about a pebble + +here that's covering this +edge, but that edge is not + +one of the induced edges. + +So these vertices are relevant. + +It's just the pebbles inside, +just among these 2k pebbles. + +So in here, there +are 2k pebbles. + +They must fully cover +the induced subgraph. + +They must cover all +the edges in here. + +That means they're +at most 2k edges + +because there's one +pebble per edge at least. + +And so there's 2k +pebbles in here. + +This means they're at +must 2k induced edges. + +Clear? + +That's the obvious direction. + +This doesn't really exploit +very much about pebbles. + +The other direction is a +little more interesting. + +Why should these +pebble covers exist? + +Because they seem +pretty constrained. + +Pebbles can't move very far. + +It's not really clearly +the same, but it is. + +So if we have the 2k property-- + +So now we know that every +subgraph of k vertices + +induces at most 2k edges. + +Now, we want to prove that +a pebble cover exists. + +I'm going to wait. + +It will become +obvious momentarily. + +This is fun. + +Sometimes, it's easier +to prove a theorem + +than it is to come +up with an algorithm. + +But in this case, it's easier +to come up with an algorithm + +than it is to prove a theorem. + +And you can use the algorithm +itself to prove the theorem, + +so I'm going to prove +this in a moment. + +Stay tuned. + +Meanwhile, we have an algorithm. + +This algorithm is +an example of what + +we call an incremental style +algorithm where you imagine + +starting with the +empty graph and then + +you put in all the edges +that belong one at a time. + +So add edges one at a time +starting from nothing. + +One detail is we're going to +imagine as edges get added, + +we want to direct them. + +We're going to direct edges +from the pebble that covers them + +to the other side. + +So if we have an edge and +we have a pebble over here, + +than I'm going to imagine +the edge as being directed + +from the pebble +to the other side. + +That's just for convenience +for expressing the algorithm + +in a moment. + +So now this is for +the 2k property. + +We'll get to an algorithm +for 2k minus 3 a little bit. + +So now we have a 4 loop over +the edge is we're going to add. + +And when I immediately add an +edge, it will not be covered, + +so it's not directed, +just some edge v-w. + +I would like to +put a pebble here, + +but it could be +both pebbles at w + +are occupied for +some other edges. + +It could be the +pebbles for v are also + +occupied for some other edges. + +That would be annoying. + +I want to somehow reassign +a pebble to cover this edge, + +so what I'm going to +do inside this 4 loop + +is search for available pebbles. + +And in this case, what +turns out to be right + +is a directed path in +this directed graph + +from either v or w +to a free pebble. + +Either I find one or I don't. + +If I find one, let's +say from v, there's + +some edge and then some other +edge and some other edge. + +And eventually, I +find a free pebble. + +Remember a free pebble is one +that's floating on the inside, + +not being used for anything. + +So what does my +picture look like? + +Remember edges are +directed from the pebbles. + +That means there was a pebble +at v being used for that edge. + +There was a pebble +at this vertex + +being used for that edge. + +There was a pebble +at this vertex + +being used for that edge. + +In this case, what do I do? + +AUDIENCE: Reverse. + +PROFESSOR: Reverse them, yeah. + +Just reverse all the edges. + +So I have this edge, v-w, here. + +I want to put a +pebble here, so I'm + +going to reassign this guy +to be over there, this guy + +to be over there, this guy +to be over there, and so on. + +So I end up with-- +that's in the way. + +Put w over here. + +The new picture +is I have v and w. + +And I'm going to have +left 4 directed edges. + +So now this pebble got +assigned to be here. + +I can't draw left apparently. + +The other left. + +This pebble assigned there. + +This pebble, the free +pebble, gets used up. + +And now we've got a +free pebble over here. + +And now we can assign it +to be on the edge v-w. + +So if I can find such a +path from v or from w, + +I'm happy because +then I can reassign. + +If I find such a path, I just +shift the pebbles like that, + +and I'm done. + +But what if I can't? + +This is the critical +issue, and it is also + +core to this part +of the proof that we + +haven't discover-- +haven't yet done. + +Why would we hope +for pebble covers + +to exist in the first place? + +We don't know. + +I claim if this +algorithm fails to find + +a path in this situation, +then you can immediately + +say you do not satisfy +the 2k property. + +I'd like to say there's +no pebble cover, + +but that's a little harder. + +I'm going to say you do not +satisfy the 2k property. + +And we actually know +already, from this part, + +pebble cover +implies 2k property. + +The contrapositive, which +we've already proved, + +is if you do not +satisfy the 2k property, + +you do not have a pebble cover. + +So that will actually guarantee +correctness of the algorithm. + +If I can prove this part, +that it violates 2k property, + +then I'll know there was no +pebble cover, and I'm done. + +So why is this true. + +I claim if you look at +all the nodes reachable + +by directed paths +from v and w, then + +that is a set of nodes that +induce more than 2k edges. + +So let's say their k +nodes you can reach. + +I claim there will be more +than 2k edges among them. + +Why? + +It's fun to have proof in +the middle of an algorithm. + +So here we've got to +v and w, and these + +are the k nodes that are +reachable from v and w, which + +means all of the other edges +are pointing into this set. + +And then, over here, +we have everybody else. + +I mean it might be everyone. + +But potentially, there's +some vertices over here. + +All the edges are directed +from right to left, + +otherwise we could +reach more stuff. + +So what's the situation? + +v-w is uncovered. + +There's no pebbles +that cover it. + +Every other edge is +covered because there's + +only one uncovered +edge at any moment. + +These edges are all +covered from this end. + +That's what these +directions mean, which + +means all the +pebbles in here are + +used to cover induced edges. + +So all the pebbles in here +are covering induced edges, + +and yet, there's one induced +edge that is not covered. + +Now they're exactly 2k pebbles. + +They're all being used. + +I'm assuming here you never +have two pebbles covering + +the same edge, so that +means-- so there's 2k pebbles. + +They're all used to cover +induced edges, which + +implies you have +exactly 2k plus 1 edges. + +Plus 1 is v-w. + +That means that means the +graph that we've created so far + +violates the 2k property. + +Now, we haven't added +all the edges yet, + +but if we add more +edge, it's going + +to get even worse potentially. + +If we have 2k plus 1 edges +now, in the actual graph, + +we'll have at least +2k plus 1 edges. + +So if this search +fails, you know + +that you violate the +2k property, which + +means you know that +there's no pebble cover. + +So that proves correctness +of the algorithm. + +Now we can come +back to this claim. + +This follows, by correctness +of the algorithm, why. + +We want to prove if we +have the 2k property, + +then you have a pebble copper. + +Well, if I have the 2k property, +this algorithm will work. + +This case can never +happen because it can only + +happen when you violate +the 2k property. + +So if you have the 2k +property, this algorithm, + +you can keep running it. + +You will always find a path. + +You'll be able to +shift the pebbles + +and always cover things, and +so you get a pebble cover + +from the algorithm. + +The end. + +That's how you argue that +if you have the 2k property, + +you get a pebble cover. + +And it's nifty. + +Without this +algorithm, this would + +be quite tricky to specify. + +But the algorithm tells +you where the violation + +would be, tells you where you +would violate the 2k property. + +And that lets you prove +the claim ultimately. + +Any questions about that. + +This, I think, is the +heart of pebble algorithms + +and why they work. + +It's the cleanest part. + +It gets a little bit messier +to do the 2k minus 3 thing, + +so we'll move to that next. + +Maybe before we go there, we +can talk about the running time + +of the algorithm for +those so inclined. + +So the heart of the +algorithm is this step, + +search for directed path +for v or w to a free pebble. + +This is essentially some of +the nodes have free pebbles. + +Those are like good nodes. + +But basically, we've +got a directed graph. + +We want to find all the nodes +that are reachable from v, + +see if there's any good +nodes that have free pebbles, + +search from all +the nodes from w. + +This you could do with a depth +first search or a breadth + +first search or your +favorite search algorithm. + +Takes linear time. + +Order the number of +vertices plus the number + +of edges in the graph. + +We do this search v times. + +Why v times? + +So we add edges one at a time. + +We're hoping that we +have the 2k property. + +The 2k property implies +that, in particular, + +there at most 2v edges. + +So in general, we +do this e times. + +We keep adding edges. + +We would add e edges +to the graph hopefully. + +In general, e can be much +larger than v in a graph. e + +could v squared, the worst case. + +But this algorithm +will fail by the time + +you add 2k plus 1 edges +because then you definitely + +don't satisfy the 2k property +over the entire graph, + +so particularly you +won't satisfy it + +on some subset of vertices. + +So you will only have to +run this loop v times, + +not e times-- or 2v times. + +So this is a little bit +smaller, and so this product + +is v squared plus ve. + +Normally, we write ve, but +this is slightly more precise, + +which is the same +as Bellman Ford + +algorithm if you've +taken algorithms. + +I'll just mention that there is +an algorithm slightly fancier + +that just requires this term. + +This is possible. + +You don't need this ve part. + +but it's beside the point +to our goal, which is just + +to understand when +things are rigid, + +when they're not in an +efficient amount of time. + +So this is polynomial +in any case. + +This also the best known +algorithm, v squared. + +Open problem is whether +you could do better. + +Questions? + +Yeah? + +AUDIENCE: Is there more than 2v +edges instead of, [INAUDIBLE] + +that [INAUDIBLE] problem. + +PROFESSOR: Yes, there +are more than to v edges. + +Oh, right! + +So there's done. + +Great. + +You can just check in the +beginning, are there more + +than to v edges. + +If so, you do not satisfy the 2k +property, and so you can stop. + +So that takes constant time to +check those cases, otherwise e + +is small. + +And then you only +take the square time. + +Thanks. + +That's key. + +So that was the 2k property. + +Let's do 2k minus 3. + +For the 2k minus +3 algorithm, it's + +going to be pretty much +the same as this algorithm. + +So in particular, every +vertex is to attach pebbles. + +Each pebble can cover +when it's in an edge, + +otherwise it's free. + +Our goal is to cover every edge. + +But it's slightly differently. + +We have to deal with +this minus 3 business. + +And for that we need +another claim, which + +is that a graph has a +2k minus 3 property if + +and only if g plus three +copies of an edge e + +has the 2k property for +every edge, e and g. + +Should probably say g has. + +So I want to know whether +my-- ultimately, I + +care whether my graph has +a 2k minus 3 property. + +This is most of the +Laman condition. + +It's the hard part to check. + +And 2k property is what +I know how to check. + +So I claim all you need +to do to check it-- + +this would actually +be an algorithm. + +For every edge, turn +that single edge + +into four copies of the +edge, add three more, + +check whether it +has the 2k property, + +remove those extra three +copies, take the next edge, + +add three copies, +check the 2k property. + +So with another +factor of e, which + +has to be order v, if you're +willing to spend v cubed time, + +you can just run this +algorithm for each edge, + +quadruple it, see whether it +still has the 2k property. + +So that's the connection +between these 2 things. + +Let me prove this claim. + +And then I'll tell +you a better algorithm + +that only takes v squared time. + +Which one's easier? + +In both cases, I want +to take k vertices. + +And then I'll do in +this direction first. + +So how do we prove this? + +First, this is +actually really easy. + +Suppose g has a 2k +minus 3 property. + +So if I have k +vertices here, I know + +that the number of edges in +here is at most 2k minus 3. + +So here's k vertices. + +Looking at the number +of induced edges, + +it's going to be +at most 2k minus 3. + +What I'm claiming is then +if I quadruple an edge, + +if I add three new edges, I have +at most 2k edges afterwards. + +I think that's pretty clear. + +2k minus 3 would be 4 at most. + +If I add three copies of any +edge, could be in this set + +or outside the set +would be even better, + +the number of edges inside +the set will be at most 2k. + +So this is in g. + +This implies there's at +most 2k and g plus thrice e. + +This is non-standard +notation by the way. + +It just means add three +copies of that edge. + +So we would normally +draw that like this, + +four copies of the edge. + +So that was half of the +claim, pretty trivial. + +The other half is +almost as trivial. + +So on the other +direction, we assume + +that g plus 3e has this +property for every edge. + +And now we need to prove +that g has a 2k minus 3 + +property for every +set of k vertices. + +So we're looking at +that set of k vertices. + +We want to argue +that in g, there's + +at most 2k minus 3 edges. + +What we know is that in here, +in g plus 3 e for any e-- + +so it's a little awkward-- +but let me start by drawing g. + +We want to claim that the +number of edges in here + +is at most 2k minus 3, so +I'll put a question mark. + +So there are 2 +possibilities here. + +It could be either this +graph is completely empty. + +If there are no edges in +here, then surely there + +are at most 2k minus +3 of them, assuming k + +is bigger than 1, which +I haven't mentioned. + +But throughout here, I need +the k is bigger than 1. + +You can never have negative +1 edges on subgraphs, + +so the 2k in the 2k +minus 3 property only + +hold for at least 2 vertices. + +K is at least 2. + +So if there are no +edges, find I'm done. + +If there are edges in here, +then I can do this trick. + +So there's some edge. + +Pick your favorite edge. + +Call it e in this subset. + +Produce out of it +g plus 3e, which + +just looks like the +same thing, but now it's + +got four copies of that edge. + +This we know has at +most 2k edges in here. + +The original graph +is exactly the same + +except it lacks those +three edges, therefore, + +there's at most 2k +minus 3 of them. + +So it's really the same +proof in both directions. + +Here, you have to +use your freedom + +in choosing e to +choose an edge that + +is induced in this subgraph. + +You can't choose some +other edge out here. + +Question? + +AUDIENCE: So this seems +kind of cheap because we're + +using the graph as a +linkage in the end, + +so adding these extra edges, +they all collapse into one. + +PROFESSOR: Ah, interesting. + +Right. + +So why this feels +like cheating because, + +from a linkage +perspective, these 2 guys + +have exactly the +same constraints. + +AUDIENCE: Yeah. + +PROFESSOR: I agree. + +It's weird. + +At this point, this is a device. + +You could think of +it as adding edges. + +Another way to think +of it is this edge + +has to be covered +by four pebbles. + +That's probably a +little more intuitive. + +So having to cover an +edge by four pebbles, + +essentially, is +pinning the edge. + +Because on the one hand, you +have a single pebble just + +to say this is an edge. + +And then you have +three more pebbles + +to eat up the translations +and rotations. + +That's intuitively +what's going on. + +I agree this looks weird. + +And at this point, we're just +playing the graph theory game + +and ignoring the linkages. + +That's the short +answer why this is OK. + +But ultimately, +intuitively, what's going on + +is that these three +edges are just + +representing the translations +and rotations being eaten. + +And they have to be +somehow eatable universally + +at every edge. + +That's what this is saying. + +I don't have a great +intuition for that, + +but it is-- pretty +sure you do need + +to say for every edge, +not just some edge. + +So at this point, you have +a polynomial time algorithm, + +so I'm done. + +But let me briefly mention +how you could make it faster + +by modifying this algorithm to +do the 2k minus 3 situation. + +Dare I-- I won't literally +modify the algorithm. + +I'll write a new version. + +But I'm going to use that +as a subroutine basically. + +And so algorithm +2k minus 3 version. + +So it's going to +be the same style. + +We're going to add +edges one at a time. + +We'll direct the edges in the +same way for each added edge + +v-w. + +I'll just write for +each added edge v-w. + +Before I just tried to add the +edge and cover it with pebble. + +Now, I want to cover +it with four pebbles. + +I want to basically add +the edge four times. + +I'm going to write as +above to mean this step. + +So every time I add +the edge, I search + +for a directed path from +v or w for free pebble. + +When I find it, I +do the pebble shift. + +I do that four times. + +Then basically, I have +four pebbles on the edge, + +or you could think of them as +being four copies of the edge, + +each has one pebble. + +Either I succeed and I get all +four, or I don't get all four. + +On success, this is just +a temporary measure. + +At that point, I'm going to +delete three of the copies. + +Put it back to a +regular single edge. + +This frees three +pebbles for future use. + +So I don't want every +edge to be quadrupled. + +I don't want them all to +be quadrupled at once. + +I want to try +quadrupling one edge, + +then try quadrupling +the next edge, + +try quadrupling the next edge. + +But when I'm +quadrupling an edge, + +all the other edges +exist as single edges. + +So I delete the three copies. + +And then this four loop +continues and tries + +the next edge. + +On failure-- here I'm +going to say something + +more interesting-- Normally, +on failure I'd say, + +well, you don't satisfy +the 2k minus 3 property. + +Game over. + +But you can be a little +more sophisticated. + +Just say delete all +the copies of e. + +I guess there's four of them. + +Whatever pebbles you can +acquire, you give them up. + +Delete the edge and +call the edge redundant. + +Basically, in this +case, you could + +argue that edge was superfluous +for rigidity purposes. + +You didn't need it. + +So the algorithm +doesn't just fail. + +It says this was a useless edge. + +And it'll tell you +which edges are useful, + +which ones are non-redundant +from a rigidity standpoint. + +And then when you're done, +you will be rigid if and only + +if the number of non-redundant +edges that remain + +equals 2n minus 3. + +So that's the last part +of the Laman check. + +So this is giving you a +little bit more information + +than just do I satisfy +the 2k minus 3 property. + +To get that, you just check +whether you ever failed. + +But in this case, +you can actually + +see, ah, these are +the useless edges. + +They're those overbracing edges. + +Everything else is useful. + +And if I end up having enough +useful edges to n minus 3 + +of them, then I know I'm rigid. + +Otherwise, I'm going +to be flexible. + +So this gives you all +the information you want. + +With a little bit +more effort, you + +could even figure out if I'm +flexible, which parts are rigid + +and which parts can move +relative to each other. + +This, of course, +generically rigid. + +Finally, let me show you +this thing in action. + +So look over there. + +This is an implementation +by Audrey Lee-Saint John. + +And so here's a simple graph. + +You can probably see this +top part is flexible. + +It's quadrilateral. + +Bottom part is overbraced. + +This is in 2 dimensions, right? + +So just triangles +would be enough, + +but I've added an +extra edge here. + +And this is going to check +the Laman condition one + +step at a time. + +So we start with 2 +pebbles everywhere. + +We start by adding +that top edge. + +Right now, there are four +pebbles on that edge, + +so it's great. + +I can just add the edge. + +Let's say I added it four times. + +There are four pebbles there. + +But then in the end, +I just need one. + +So let's skip that step. + +And now I've got the one +pebble from b, and we're happy. + +So that is its own +rigid component. + +Next, let's add this edge ef. + +So this also has four +pebbles on it, so we're done. + +Next, we have cd. + +That also has-- you +could change the order + +if you think this +one's a little trivial. + +Now is when the action happens. + +Let's add this edge bc. + +So currently, it is only +covered by three pebbles. + +But we need a fourth. + +So we're going to take one +of these free pebbles on a + +and move it along b. + +We found that by starting +from b and searching out + +and finding a free pebble. + +So we just flip that edge. + +Now we've got a +free pebble on b. + +Now we've got four pebbles on +bc, and we can add the edge. + +But we only actually +take one of them. + +So I'm skipping the part +where we add the four copies + +and immediately remove three +of them because that's silly. + +Cool. + +So that's its own rigid +component it turns out. + +Each of these things +is independently-- + +the colors represent +rigid components. + +And right now nothing +is tied together. + +Everything's flexible. + +Flexible at b. + +Flexible at c. + +Let's add this diagonal df. + +So right now, it +only has one pebble, + +which means we +need four pebbles. + +So we're actually going +to have to get one at f, + +and we're going +to have to get one + +at d because there can +only be two at each. + +So first, we'll do I +guess a search from d, + +and we immediately +find a pebble. + +We move it down there. + +Great. + +Then, we search from f. + +We find a pebble there. + +We move it. + +Boom! + +We've got our edge, +added all four pebbles. + +Eventually we're going +to run out of pebbles, + +but right now, we +are very flexible. + +Let's add this other diagonal. + +This should also be possible. + +Right now, there's one +pebble at e, one pebble at c. + +We've got to find +two more pebbles. + +So first, we'll +follow this edge. + +Find a free pebble at f. + +That was easy. + +Next, we'll look at from c. + +There's only one way +we can go from c. + +We can't follow the back edge. + +Got to go forward. + +Got a pebble at d. + +Flip it around. + +Now, we've got four pebbles on +c and e, so we can add the edge. + +Now, let's add ef. + +Right now, we've only got +one pebble, yet we need four. + +So let's start by +searching from a. + +Oh, we found a +pebble immediately. + +In general, we would have +to follow many edges. + +So there's a from f. + +There are two ways we could go. + +Either one of them would +have given us a pebble. + +Let's flip the yellow edge. + +Boom! + +We've got f, one pebble, +but we need another one. + +Now, we cannot get another +pebble from e because we just + +flipped the edge, but we +can get a pebble from d, + +so we flip that edge. + +And now we can add the +edge af to more edges. + +It's a little tedious. + +So next is cf. + +We're running out +of pebbles here. + +There's only five pebbles +total in the system. + +We need four of them +right here because we're + +getting almost rigid. + +So let's see. + +We've got cf. + +Let's start from +searching from f. + +There's only one way we can go. + +We find a pebble. + +We flip it around. + +Now we've got c. + +There's only one +way to go from c. + +We find the pebble at e. + +And we flip it around. + +Now we've got the two pebbles. + +Cool. + +So we've got the +three pebbles here, + +which are representing our +translations and rotations. + +The only other pebble +left is this one, + +which is basically representing +the degree of freedom + +in this quadrilateral. + +So when we go to add the +last edge, which is-- so + +at this point, this is +a ridge it component + +because of the triangles. + +And we go to add +the last edge, we + +will fail to find +enough pebbles. + +Let's see. + +We can find three of them. + +We can grab the one from e. + +Or let's see so-- it's +not going to show us. + +But from e, we can grab +f, the pebble at f. + +From d, we can grab +the pebble at c. + +From d, we can grab +the other pebble at f. + +We've got three +pebbles, but there's + +no way to get to this pebble +because both of these edges + +are directed down. + +So you can never get from the +below part to the above part. + +So it's not obvious +that this is working. + +That's what the proof is for. + +But at least you +see it in action. + +I'll just run it very +quickly for another graph. + +Let's say a big one. + +This one is minimally, +generically rigid. + +So it's fun to +watch for a while. + +You get pebbles moving around. + +In this case, you +have some longer paths + +you have to follow to +get enough pebbles. + +It depends a lot on the +insertion order that you use. + +So in each case, you need four +pebbles, two on each side. + +And if so, you +can add your edge. + +Otherwise, you can't. + +What I haven't described +is this color coding + +which is figuring out when +you have rigid components. + +Roughly speaking, to find +what your rigid component is-- + +if you're an edge, you want to +know what rigid component am + +I in-- you basically just +search for all the vertices + +that are reachable +from your edge. + +Those are all in +your rigid component. + +That's what we saw. + +So this graph happens +to be minimally rigid, + +and it detects that. + +But then it can be +a little bit more + +as in your rigid component. + +Some of the incoming +edges-- let's see. + +Draw a picture. + +So here's everything +you can reach from v-w. + +And say you're following +an incoming edge here + +from some other vertex u. + +And then suppose these +are all the things + +you can reach from you. + +If there are zero +pebbles out here, + +then this whole thing +is a rigid component. + +And you just keep doing that. + +You check an incoming edge. + +If there's zero pebbles +in that reachable piece, + +then you merge. + +And you keep doing that. + +Those are all the things that +are rigidly attached to you. + +So I won't prove that. + +It's a little tricky to +prove, but it's fairly easy + +to compute. + +And you could actually do it +in the same amount of time. + +As you're building +this thing up, + +you can do the color +coding to figure out + +which things are in the +same component, which things + +are in different components. + +Let's see. + +So another fun fact +is this little part. + +This says it's the +2k minus 3 property. + +The same algorithm you could +use to check 5k minus 27, + +or whatever you want, for fixed +numbers like two and three, + +the same pebble +algorithm can detect + +that ak minus b property. + +And that's actually useful +for a lot of different things. + +This is done originally +by Lee and Streinu. + +Same lee, and Streinu +we'll be seeing + +some of her results in a +couple of classes as well. + +For example-- so this is +that-- 3D body and bar. + +So actually let me +show you the kind + +of scenario we're +thinking about. + +So I mentioned 3D. + +If we have vertices +and bars between them, + +we don't know how to +characterize generic rigidity. + +But a slightly different +problem, which is 3D bodies, + +these are polyhedron. + +And they have bars +connected between them. + +This we know how to solve +in 3D and in any dimension. + +And so this is a picture +of not only having-- + +so their bodies can +spin unlike vertices. + +Vertices can't rotate. + +Nothing happens when +you rotate a vertex. + +Bodies have this extra +degree of freedom. + +So there are two things +we're allowing here, + +one is to add a hinge +between two bodies + +and the other is to add +bars connecting them + +from various random points. + +And it's generic, so these +points will never coincide. + +I think that's what makes +this different from a vertex. + +Vertex bars always coincide. + +Here, they all just +attach to generic points. + +So it turns out you can +simulate a hinge by five bars. + +They're equivalent. + +So both of these can be +captured by 6K minus 6 property. + +Turns out these things will +be generically rigid if + +and only if you satisfy +the 6K minus 6 property + +and you have exactly +6K minus 6 bars. + +And this is proved by +two or three people. + +I mean you need to add +two results together, + +one from the '90s and +one from much older, + +I think, in graph theory. + +But in particular, Tae +was involved from 1984. + +And it's funny. + +The paper starts out with, if +you ask any structural engineer + +if you have two +bodies how many bars + +you have to add to rigidify +them, they will say six. + +I'm like, OK, I +didn't know that. + +But six is the right answer. + +And that's why the +6K minus 6 basically. + +And and we can use +this pebble algorithm + +to solve that for +free basically. + +And this is actually +implemented here + +in the same kind of software. + +I'll just run it quickly +because it's a lot of pebbles. + +Every vertex has six pebbles. + +You just keep going. + +You need to cover every +edge with how many pebbles? + +Before it was four, +so now it should be 7, + +I believe, one more +than the six here. + +So 6k minus 6. + +Anyway, this graph, +while it's not obvious, + +is minimally rigid +in this world. + +And it corresponds exactly +to the left example. + +It's hard to see because +we've replaced the hinges here + +by six bars. + +So that's why we got all the +six-- all the duplicated edges. + +Here, you see the duplicated +are different from a rigidity + +standpoint because having three +edges between the same pair + +of objects is no longer just +the same as having one edge + +because they attach +to different points. + +Each one can spin. + +These are universal +joints by the way. + +So these bars can +rotate around the body. + +The body can spin. + +Lots of things can happen. + +But this is enough to rigidify. + +Is there a question? + +Cool. + +I'm not going to prove that. + +You can read the papers +if you're interested. + +But it's interesting. + +Bodies and bars are so much +easier than other things. + +One other thing you can do +is called angular rigidity. + +This is a fairly new +result by same people. + +If you have a bunch of +lines in 3D, and you + +have angular constraints. + +In this case, every +triple of these lines + +has an angular constraint that +it must be equal to alpha. + +That's what's drawn on +this spherical picture. + +Over here, we have two bodies. + +So here we have lines. + +Here, we have bodies. + +And there are three +constraints that + +fix the angles between how the +angles meet at these bodies. + +And they claim is that both +of these are angularly rigid, + +meaning things can +still slide up and down, + +but the angles are all fixed. + +And you can test this again. + +This case actually turns out +it's the 2k minus 3 property + +again, same as Laman. + +This one, I've forgotten. + +I have to check. + +I think it's 3k minus 3. + +Yeah, 3k minus 3. + +So cool things. + +One last question. + +Connected banana. + +So there's this three banana +example-- or two banana + +example. + +I'm getting ahead of +myself-- which was weird. + +You have this one banana on the +left, one banana on the right. + +And there's this implicit, +implied hinge, as they call it, + +between the two points. + +The whole thing is flexible, +but if you check it, + +it satisfies the Lama condition. + +It satisfies 3k +minus 6, which is + +what it should be +for 3D rigidity. + +This is a 3D. + +Now, this graph is-- +seems trivial-- I + +mean it seems easy to figure +out that this is flexible + +because there's a two cut. + +There are two vertices +you can remove + +that disconnect the +graph into two pieces. + +So if you could just subdivide, +do the left part separately + +from the right part, you should +be able to figure this out. + +Unfortunately, this example +can be made more connected, + +and that's what +the question was. + +So this is an old +example by Henry Crapo. + +A modification by +Walter Whiteley + +is that if you add a single +point here and attach it + +to those two points-- +sorry, those three points-- + +this will be three connected, +still be flexible, and still + +satisfy Laman because we added +three edges and one vertex, + +so it still satisfies Laman. + +So that sucks. + +We think, oh, maybe +four connected. + +Well, you can make it +four connected, too, + +by adding a triangle +in the center + +and connecting these six, +adding these 6 connections. + +Well, what about 5 connected? + +Well, five connected, +you can also do. + +And this is an example +called the banana spider. + +Although it seems a +bit of a misnomer. + +It should be-- but I +guess banana spiders + +are actual object-- +actual species. + +This really should +be a banana insect + +because this guy +has six legs, three + +on the left, three on the right. + +So if it is an +octahedron in the center, + +and then you add these +three connections, + +and you can actually prove +that any graph you have, + +any example that's maybe only +one or two or three connected, + +whatever, you can make it five +connected by whenever you have + +two four connected components-- +or five things components + +I guess-- just add a spider +in the middle to bridge them, + +and it will be as +flexible as before. + +And it will still satisfy Laman. + +So five connectivity doesn't +buy you anything unfortunately. + +I guess you could ask +for six connectivity, + +but six connectivity, +I think, is impossible + +because you only have +3n minus 6 edges. + +That's the limit. + +So sadly, connectivity is not +the right-- doesn't buy us + +anything. + +And that's what we know about +vertex and bar structures in 3D + +sadly. + +Tough open problem. + +Any questions? + +That's it for today. \ No newline at end of file diff --git a/ziJc5pSF5aM.txt b/ziJc5pSF5aM.txt new file mode 100644 index 0000000000000000000000000000000000000000..beabe0c297db72d85dfe3bf2d6689c86d3b535d8 --- /dev/null +++ b/ziJc5pSF5aM.txt @@ -0,0 +1,3251 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi welcome back i am dr. bugged alpha + + align:start position:0% +hi welcome back i am dr. bugged alpha + + + align:start position:0% +hi welcome back i am dr. bugged alpha +delish let's solve some more + + align:start position:0% +delish let's solve some more + + + align:start position:0% +delish let's solve some more +biochemistry problems today we're going + + align:start position:0% +biochemistry problems today we're going + + + align:start position:0% +biochemistry problems today we're going +to be talking about problem 3 a problem + + align:start position:0% +to be talking about problem 3 a problem + + + align:start position:0% +to be talking about problem 3 a problem +set 10 now this is a problem about the + + align:start position:0% +set 10 now this is a problem about the + + + align:start position:0% +set 10 now this is a problem about the +spontaneity of gluconeogenesis as you + + align:start position:0% +spontaneity of gluconeogenesis as you + + + align:start position:0% +spontaneity of gluconeogenesis as you +guys have already learned + + align:start position:0% +guys have already learned + + + align:start position:0% +guys have already learned +gluconeogenesis is the process by which + + align:start position:0% +gluconeogenesis is the process by which + + + align:start position:0% +gluconeogenesis is the process by which +non-sugar precursors are used to produce + + align:start position:0% +non-sugar precursors are used to produce + + + align:start position:0% +non-sugar precursors are used to produce +glucose this problem should help you + + align:start position:0% +glucose this problem should help you + + + align:start position:0% +glucose this problem should help you +think of the following conundrum in a + + align:start position:0% +think of the following conundrum in a + + + align:start position:0% +think of the following conundrum in a +Cell when we have glucose we can make + + align:start position:0% +Cell when we have glucose we can make + + + align:start position:0% +Cell when we have glucose we can make +energy by doing glycolysis but at the + + align:start position:0% +energy by doing glycolysis but at the + + + align:start position:0% +energy by doing glycolysis but at the +same time the cell can take for example + + align:start position:0% +same time the cell can take for example + + + align:start position:0% +same time the cell can take for example +the endpoints of glycolysis such as + + align:start position:0% +the endpoints of glycolysis such as + + + align:start position:0% +the endpoints of glycolysis such as +pyruvate or even further metabolites + + align:start position:0% +pyruvate or even further metabolites + + + align:start position:0% +pyruvate or even further metabolites +like amino acids and use the pathway in + + align:start position:0% +like amino acids and use the pathway in + + + align:start position:0% +like amino acids and use the pathway in +Reverse to make glucose now if one + + align:start position:0% +Reverse to make glucose now if one + + + align:start position:0% +Reverse to make glucose now if one +process is spontaneous in terms of time + + align:start position:0% +process is spontaneous in terms of time + + + align:start position:0% +process is spontaneous in terms of time +thermodynamics then how could we run the + + align:start position:0% +thermodynamics then how could we run the + + + align:start position:0% +thermodynamics then how could we run the +reaction in Reverse so here we're going + + align:start position:0% +reaction in Reverse so here we're going + + + align:start position:0% +reaction in Reverse so here we're going +to be looking at a couple of steps of + + align:start position:0% +to be looking at a couple of steps of + + + align:start position:0% +to be looking at a couple of steps of +gluconeogenesis that are the exact + + align:start position:0% +gluconeogenesis that are the exact + + + align:start position:0% +gluconeogenesis that are the exact +reverse of the reactions that you've + + align:start position:0% +reverse of the reactions that you've + + + align:start position:0% +reverse of the reactions that you've +seen already in glycolysis and then in + + align:start position:0% +seen already in glycolysis and then in + + + align:start position:0% +seen already in glycolysis and then in +the end we're going to be talking about + + align:start position:0% +the end we're going to be talking about + + + align:start position:0% +the end we're going to be talking about +the whole pathway level and make some + + align:start position:0% +the whole pathway level and make some + + + align:start position:0% +the whole pathway level and make some +comments on the spontaneity of both + + align:start position:0% +comments on the spontaneity of both + + + align:start position:0% +comments on the spontaneity of both +glycolysis and gluconeogenesis + + align:start position:0% + + + + align:start position:0% + +part a of the problem deals with the + + align:start position:0% +part a of the problem deals with the + + + align:start position:0% +part a of the problem deals with the +aldolase reaction namely going from + + align:start position:0% +aldolase reaction namely going from + + + align:start position:0% +aldolase reaction namely going from +fructose 1 6 bisphosphate to + + align:start position:0% +fructose 1 6 bisphosphate to + + + align:start position:0% +fructose 1 6 bisphosphate to +glyceraldehyde-3-phosphate and by haider + + align:start position:0% +glyceraldehyde-3-phosphate and by haider + + + align:start position:0% +glyceraldehyde-3-phosphate and by haider +acetone phosphate now in gluconeogenesis + + align:start position:0% +acetone phosphate now in gluconeogenesis + + + align:start position:0% +acetone phosphate now in gluconeogenesis +will be going in reverse starting with + + align:start position:0% +will be going in reverse starting with + + + align:start position:0% +will be going in reverse starting with +the Hydra acetone phosphate and + + align:start position:0% +the Hydra acetone phosphate and + + + align:start position:0% +the Hydra acetone phosphate and +glyceraldehyde 3-phosphate to regenerate + + align:start position:0% +glyceraldehyde 3-phosphate to regenerate + + + align:start position:0% +glyceraldehyde 3-phosphate to regenerate +fructose 1 6 bisphosphate let's take a + + align:start position:0% +fructose 1 6 bisphosphate let's take a + + + align:start position:0% +fructose 1 6 bisphosphate let's take a +look at the reaction this is the hydro + + align:start position:0% +look at the reaction this is the hydro + + + align:start position:0% +look at the reaction this is the hydro +acetone phosphate this is + + align:start position:0% +acetone phosphate this is + + + align:start position:0% +acetone phosphate this is +glyceraldehyde-3-phosphate or gap and + + align:start position:0% +glyceraldehyde-3-phosphate or gap and + + + align:start position:0% +glyceraldehyde-3-phosphate or gap and +these two come together in the aldolase + + align:start position:0% +these two come together in the aldolase + + + align:start position:0% +these two come together in the aldolase +reaction to form fructose 1 6 + + align:start position:0% +reaction to form fructose 1 6 + + + align:start position:0% +reaction to form fructose 1 6 +bisphosphate or f 16 BP now the part 1 + + align:start position:0% +bisphosphate or f 16 BP now the part 1 + + + align:start position:0% +bisphosphate or f 16 BP now the part 1 +of the question asked us to write down + + align:start position:0% +of the question asked us to write down + + + align:start position:0% +of the question asked us to write down +the detailed mechanism for this reaction + + align:start position:0% +the detailed mechanism for this reaction + + + align:start position:0% +the detailed mechanism for this reaction +running in reverse so as you guys know + + align:start position:0% +running in reverse so as you guys know + + + align:start position:0% +running in reverse so as you guys know +aldolase specifically the class 1 alder + + align:start position:0% +aldolase specifically the class 1 alder + + + align:start position:0% +aldolase specifically the class 1 alder +lazes use an active site lysine residue + + align:start position:0% +lazes use an active site lysine residue + + + align:start position:0% +lazes use an active site lysine residue +to to covalently bind the substrate + + align:start position:0% +to to covalently bind the substrate + + + align:start position:0% +to to covalently bind the substrate +during the course of the reaction so + + align:start position:0% +during the course of the reaction so + + + align:start position:0% +during the course of the reaction so +this reaction will proceed by dihydrogen + + align:start position:0% +this reaction will proceed by dihydrogen + + + align:start position:0% +this reaction will proceed by dihydrogen +phosphate binding to the exercise lysine + + align:start position:0% +phosphate binding to the exercise lysine + + + align:start position:0% +phosphate binding to the exercise lysine +of the aldolase here we have the + + align:start position:0% +of the aldolase here we have the + + + align:start position:0% +of the aldolase here we have the +dihydrogen phosphate and the lysine in + + align:start position:0% +dihydrogen phosphate and the lysine in + + + align:start position:0% +dihydrogen phosphate and the lysine in +the active site so as the first step of + + align:start position:0% +the active site so as the first step of + + + align:start position:0% +the active site so as the first step of +the mechanism the lysine is going to + + align:start position:0% +the mechanism the lysine is going to + + + align:start position:0% +the mechanism the lysine is going to +react with the carbonyl group in that + + align:start position:0% +react with the carbonyl group in that + + + align:start position:0% +react with the carbonyl group in that +hydrostan phosphate to form a ship space + + align:start position:0% +hydrostan phosphate to form a ship space + + + align:start position:0% +hydrostan phosphate to form a ship space +or an e mean as you can imagine the + + align:start position:0% +or an e mean as you can imagine the + + + align:start position:0% +or an e mean as you can imagine the +reaction is going to be catalyzed by the + + align:start position:0% +reaction is going to be catalyzed by the + + + align:start position:0% +reaction is going to be catalyzed by the +general base which is going to remove + + align:start position:0% +general base which is going to remove + + + align:start position:0% +general base which is going to remove +one of the protons from the lysine which + + align:start position:0% +one of the protons from the lysine which + + + align:start position:0% +one of the protons from the lysine which +then becomes a good nucleophile and can + + align:start position:0% +then becomes a good nucleophile and can + + + align:start position:0% +then becomes a good nucleophile and can +attack the carbonyl which can then will + + align:start position:0% +attack the carbonyl which can then will + + + align:start position:0% +attack the carbonyl which can then will +be protonated by a general acid so this + + align:start position:0% +be protonated by a general acid so this + + + align:start position:0% +be protonated by a general acid so this +way you obtain an intermediate as shown + + align:start position:0% +way you obtain an intermediate as shown + + + align:start position:0% +way you obtain an intermediate as shown +here which can then lose the water + + align:start position:0% +here which can then lose the water + + + align:start position:0% +here which can then lose the water +molecule to form the shift base once + + align:start position:0% +molecule to form the shift base once + + + align:start position:0% +molecule to form the shift base once +again we need a base that will + + align:start position:0% +again we need a base that will + + + align:start position:0% +again we need a base that will +take this proton and then the water will + + align:start position:0% +take this proton and then the water will + + + align:start position:0% +take this proton and then the water will +need another acid molecule to leave so + + align:start position:0% +need another acid molecule to leave so + + + align:start position:0% +need another acid molecule to leave so +what we have formed here this is the + + align:start position:0% +what we have formed here this is the + + + align:start position:0% +what we have formed here this is the +protonated shift base or what we call an + + align:start position:0% +protonated shift base or what we call an + + + align:start position:0% +protonated shift base or what we call an +amine IAM ion and if you look at edit + + align:start position:0% +amine IAM ion and if you look at edit + + + align:start position:0% +amine IAM ion and if you look at edit +from the point of view of where we + + align:start position:0% +from the point of view of where we + + + align:start position:0% +from the point of view of where we +started from which was a carbonyl group + + align:start position:0% +started from which was a carbonyl group + + + align:start position:0% +started from which was a carbonyl group +this is a version of an activated + + align:start position:0% +this is a version of an activated + + + align:start position:0% +this is a version of an activated +carbonyl carbon yo Derwood it's now + + align:start position:0% +carbonyl carbon yo Derwood it's now + + + align:start position:0% +carbonyl carbon yo Derwood it's now +poised to do chemistry once again this + + align:start position:0% +poised to do chemistry once again this + + + align:start position:0% +poised to do chemistry once again this +is this is the iminium ion now as we + + align:start position:0% +is this is the iminium ion now as we + + + align:start position:0% +is this is the iminium ion now as we +talked in the carbonyl video aminium + + align:start position:0% +talked in the carbonyl video aminium + + + align:start position:0% +talked in the carbonyl video aminium +ions are activated carbonyls that can + + align:start position:0% +ions are activated carbonyls that can + + + align:start position:0% +ions are activated carbonyls that can +now undergo some of the carbonyl + + align:start position:0% +now undergo some of the carbonyl + + + align:start position:0% +now undergo some of the carbonyl +reactions which more ease for example + + align:start position:0% +reactions which more ease for example + + + align:start position:0% +reactions which more ease for example +this one is going to do an inhalation so + + align:start position:0% +this one is going to do an inhalation so + + + align:start position:0% +this one is going to do an inhalation so +we have highlighted here the alpha + + align:start position:0% +we have highlighted here the alpha + + + align:start position:0% +we have highlighted here the alpha +hydrogen next to the carbonyl group so + + align:start position:0% +hydrogen next to the carbonyl group so + + + align:start position:0% +hydrogen next to the carbonyl group so +we were going to form the you know by + + align:start position:0% +we were going to form the you know by + + + align:start position:0% +we were going to form the you know by +removing this hydrogen and the carbonyl + + align:start position:0% +removing this hydrogen and the carbonyl + + + align:start position:0% +removing this hydrogen and the carbonyl +with this positive charge on the + + align:start position:0% +with this positive charge on the + + + align:start position:0% +with this positive charge on the +nitrogen so that a very good electron + + align:start position:0% +nitrogen so that a very good electron + + + align:start position:0% +nitrogen so that a very good electron +sink so what we're forming here is a an + + align:start position:0% +sink so what we're forming here is a an + + + align:start position:0% +sink so what we're forming here is a an +amine that's bound to a double bond this + + align:start position:0% +amine that's bound to a double bond this + + + align:start position:0% +amine that's bound to a double bond this +we're going to call and in amin now this + + align:start position:0% +we're going to call and in amin now this + + + align:start position:0% +we're going to call and in amin now this +is the reactive version of the + + align:start position:0% +is the reactive version of the + + + align:start position:0% +is the reactive version of the +dihydrogen phosphate now it's poised to + + align:start position:0% +dihydrogen phosphate now it's poised to + + + align:start position:0% +dihydrogen phosphate now it's poised to +react with the other partner in the + + align:start position:0% +react with the other partner in the + + + align:start position:0% +react with the other partner in the +reaction gap glyceraldehyde-3-phosphate + + align:start position:0% +reaction gap glyceraldehyde-3-phosphate + + + align:start position:0% +reaction gap glyceraldehyde-3-phosphate +which we've shown here now gap is going + + align:start position:0% +which we've shown here now gap is going + + + align:start position:0% +which we've shown here now gap is going +to be the carbonyl component of this + + align:start position:0% +to be the carbonyl component of this + + + align:start position:0% +to be the carbonyl component of this +aldol reaction while the eno mean from + + align:start position:0% +aldol reaction while the eno mean from + + + align:start position:0% +aldol reaction while the eno mean from +the dihydrogen phosphate is going to be + + align:start position:0% +the dihydrogen phosphate is going to be + + + align:start position:0% +the dihydrogen phosphate is going to be +the the enoli component right so the + + align:start position:0% +the the enoli component right so the + + + align:start position:0% +the the enoli component right so the +enol is going to be a very good + + align:start position:0% +enol is going to be a very good + + + align:start position:0% +enol is going to be a very good +nucleophile and it's going to attack the + + align:start position:0% +nucleophile and it's going to attack the + + + align:start position:0% +nucleophile and it's going to attack the +carbonyl the reaction is once again + + align:start position:0% +carbonyl the reaction is once again + + + align:start position:0% +carbonyl the reaction is once again +initiated by this amine group the + + align:start position:0% +initiated by this amine group the + + + align:start position:0% +initiated by this amine group the +electrons move here then this attacks + + align:start position:0% +electrons move here then this attacks + + + align:start position:0% +electrons move here then this attacks +the carbonyl and we can protonate it + + align:start position:0% +the carbonyl and we can protonate it + + + align:start position:0% +the carbonyl and we can protonate it +with a general acid + + align:start position:0% +with a general acid + + + align:start position:0% +with a general acid +so what we obtain here it's now a + + align:start position:0% +so what we obtain here it's now a + + + align:start position:0% +so what we obtain here it's now a +molecule that has from two portions of + + align:start position:0% +molecule that has from two portions of + + + align:start position:0% +molecule that has from two portions of +three it's going to have six carbons and + + align:start position:0% +three it's going to have six carbons and + + + align:start position:0% +three it's going to have six carbons and +if you look closely this is really the + + align:start position:0% +if you look closely this is really the + + + align:start position:0% +if you look closely this is really the +fructose 1 6 bisphosphate bound to the + + align:start position:0% +fructose 1 6 bisphosphate bound to the + + + align:start position:0% +fructose 1 6 bisphosphate bound to the +active site of the enzyme as a shift + + align:start position:0% +active site of the enzyme as a shift + + + align:start position:0% +active site of the enzyme as a shift +space okay so now all that needs to + + align:start position:0% +space okay so now all that needs to + + + align:start position:0% +space okay so now all that needs to +happen now is to hydrolyze the ship + + align:start position:0% +happen now is to hydrolyze the ship + + + align:start position:0% +happen now is to hydrolyze the ship +space and release ours are fructose 1 6 + + align:start position:0% +space and release ours are fructose 1 6 + + + align:start position:0% +space and release ours are fructose 1 6 +bisphosphate product so we're going to + + align:start position:0% +bisphosphate product so we're going to + + + align:start position:0% +bisphosphate product so we're going to +need one water molecule it's going to be + + align:start position:0% +need one water molecule it's going to be + + + align:start position:0% +need one water molecule it's going to be +activated by a general base then it's + + align:start position:0% +activated by a general base then it's + + + align:start position:0% +activated by a general base then it's +going to attack this amine and the + + align:start position:0% +going to attack this amine and the + + + align:start position:0% +going to attack this amine and the +electrons will move to the nitrogen we + + align:start position:0% +electrons will move to the nitrogen we + + + align:start position:0% +electrons will move to the nitrogen we +get to this step and here we need step + + align:start position:0% +get to this step and here we need step + + + align:start position:0% +get to this step and here we need step +in catalysis to regenerate the enzyme to + + align:start position:0% +in catalysis to regenerate the enzyme to + + + align:start position:0% +in catalysis to regenerate the enzyme to +its free lysine form and then release + + align:start position:0% +its free lysine form and then release + + + align:start position:0% +its free lysine form and then release +the fructose 1 6 bisphosphate product of + + align:start position:0% +the fructose 1 6 bisphosphate product of + + + align:start position:0% +the fructose 1 6 bisphosphate product of +the reaction so once again we started + + align:start position:0% +the reaction so once again we started + + + align:start position:0% +the reaction so once again we started +with dihydrogen phosphate and gap and + + align:start position:0% +with dihydrogen phosphate and gap and + + + align:start position:0% +with dihydrogen phosphate and gap and +you use this covalent catalysis where + + align:start position:0% +you use this covalent catalysis where + + + align:start position:0% +you use this covalent catalysis where +the substrate were bound in the active + + align:start position:0% +the substrate were bound in the active + + + align:start position:0% +the substrate were bound in the active +site of the enzyme to form our product + + align:start position:0% +site of the enzyme to form our product + + + align:start position:0% +site of the enzyme to form our product +fructose 1 6 bisphosphate now this as we + + align:start position:0% +fructose 1 6 bisphosphate now this as we + + + align:start position:0% +fructose 1 6 bisphosphate now this as we +discussed in the carbonyl chemistry just + + align:start position:0% +discussed in the carbonyl chemistry just + + + align:start position:0% +discussed in the carbonyl chemistry just +an example of direct aldol reaction and + + align:start position:0% +an example of direct aldol reaction and + + + align:start position:0% +an example of direct aldol reaction and +as the name of the enzyme suggests + + align:start position:0% +as the name of the enzyme suggests + + + align:start position:0% +as the name of the enzyme suggests +aldolase this is the reaction going in + + align:start position:0% +aldolase this is the reaction going in + + + align:start position:0% +aldolase this is the reaction going in +the gluconeogenic mold + + align:start position:0% + + + + align:start position:0% + +and part b of the question we're going + + align:start position:0% +and part b of the question we're going + + + align:start position:0% +and part b of the question we're going +to look in another important reaction + + align:start position:0% +to look in another important reaction + + + align:start position:0% +to look in another important reaction +that can run both ways in glycolysis and + + align:start position:0% +that can run both ways in glycolysis and + + + align:start position:0% +that can run both ways in glycolysis and +gluconeogenesis that will be + + align:start position:0% +gluconeogenesis that will be + + + align:start position:0% +gluconeogenesis that will be +specifically going from + + align:start position:0% +specifically going from + + + align:start position:0% +specifically going from +glyceraldehyde-3-phosphate or gap to 13 + + align:start position:0% +glyceraldehyde-3-phosphate or gap to 13 + + + align:start position:0% +glyceraldehyde-3-phosphate or gap to 13 +bits phosphoglycerate this is the + + align:start position:0% +bits phosphoglycerate this is the + + + align:start position:0% +bits phosphoglycerate this is the +reaction catalyzed by gap dehydrogenase + + align:start position:0% +reaction catalyzed by gap dehydrogenase + + + align:start position:0% +reaction catalyzed by gap dehydrogenase +here is a representation of the reaction + + align:start position:0% +here is a representation of the reaction + + + align:start position:0% +here is a representation of the reaction +we have glyceraldehyde-3-phosphate that + + align:start position:0% +we have glyceraldehyde-3-phosphate that + + + align:start position:0% +we have glyceraldehyde-3-phosphate that +is converted by gap th to the 13 bits + + align:start position:0% +is converted by gap th to the 13 bits + + + align:start position:0% +is converted by gap th to the 13 bits +forceful glyceride now in the glycolysis + + align:start position:0% +forceful glyceride now in the glycolysis + + + align:start position:0% +forceful glyceride now in the glycolysis +step we know we need one nad equivalent + + align:start position:0% +step we know we need one nad equivalent + + + align:start position:0% +step we know we need one nad equivalent +and one phosphate inorganic phosphate to + + align:start position:0% +and one phosphate inorganic phosphate to + + + align:start position:0% +and one phosphate inorganic phosphate to +go into the enzyme to be able to oxidize + + align:start position:0% +go into the enzyme to be able to oxidize + + + align:start position:0% +go into the enzyme to be able to oxidize +our aldehyde to an sitting and hydride + + align:start position:0% +our aldehyde to an sitting and hydride + + + align:start position:0% +our aldehyde to an sitting and hydride +in 13 bits phosphoglycerate now in a + + align:start position:0% +in 13 bits phosphoglycerate now in a + + + align:start position:0% +in 13 bits phosphoglycerate now in a +gluconeogenesis we're going to be going + + align:start position:0% +gluconeogenesis we're going to be going + + + align:start position:0% +gluconeogenesis we're going to be going +from right to left we're starting with + + align:start position:0% +from right to left we're starting with + + + align:start position:0% +from right to left we're starting with +13 bits phosphoglycerate we're going to + + align:start position:0% +13 bits phosphoglycerate we're going to + + + align:start position:0% +13 bits phosphoglycerate we're going to +need nadh and we're going to generate + + align:start position:0% +need nadh and we're going to generate + + + align:start position:0% +need nadh and we're going to generate +gap and inorganic phosphate now let's + + align:start position:0% +gap and inorganic phosphate now let's + + + align:start position:0% +gap and inorganic phosphate now let's +take a closer look at the mechanism of + + align:start position:0% +take a closer look at the mechanism of + + + align:start position:0% +take a closer look at the mechanism of +this reaction as it would run in + + align:start position:0% +this reaction as it would run in + + + align:start position:0% +this reaction as it would run in +gluconeogenesis here we have a + + align:start position:0% +gluconeogenesis here we have a + + + align:start position:0% +gluconeogenesis here we have a +representation of the active side of the + + align:start position:0% +representation of the active side of the + + + align:start position:0% +representation of the active side of the +gap th where we highlighted the Sistine + + align:start position:0% +gap th where we highlighted the Sistine + + + align:start position:0% +gap th where we highlighted the Sistine +group SH right and we also have in + + align:start position:0% +group SH right and we also have in + + + align:start position:0% +group SH right and we also have in +general base in the exercise we're going + + align:start position:0% +general base in the exercise we're going + + + align:start position:0% +general base in the exercise we're going +to call it be and here is our starting + + align:start position:0% +to call it be and here is our starting + + + align:start position:0% +to call it be and here is our starting +material 13 / phosphoglycerate now if + + align:start position:0% +material 13 / phosphoglycerate now if + + + align:start position:0% +material 13 / phosphoglycerate now if +you remember how gap the edge works in + + align:start position:0% +you remember how gap the edge works in + + + align:start position:0% +you remember how gap the edge works in +the direct reaction in the glycolysis + + align:start position:0% +the direct reaction in the glycolysis + + + align:start position:0% +the direct reaction in the glycolysis +we're going to have to form a covalent + + align:start position:0% +we're going to have to form a covalent + + + align:start position:0% +we're going to have to form a covalent +intermediate in which the substrate is + + align:start position:0% +intermediate in which the substrate is + + + align:start position:0% +intermediate in which the substrate is +going to bind to the enzyme that's going + + align:start position:0% +going to bind to the enzyme that's going + + + align:start position:0% +going to bind to the enzyme that's going +to form a a diode ester with that tile + + align:start position:0% +to form a a diode ester with that tile + + + align:start position:0% +to form a a diode ester with that tile +group of the Sistine so this is what's + + align:start position:0% +group of the Sistine so this is what's + + + align:start position:0% +group of the Sistine so this is what's +going to happen here so the base in the + + align:start position:0% +going to happen here so the base in the + + + align:start position:0% +going to happen here so the base in the +active side actually is going to assist + + align:start position:0% +active side actually is going to assist + + + align:start position:0% +active side actually is going to assist +deprotonation of the Sistine then the + + align:start position:0% +deprotonation of the Sistine then the + + + align:start position:0% +deprotonation of the Sistine then the +tile now it's activated and it can + + align:start position:0% +tile now it's activated and it can + + + align:start position:0% +tile now it's activated and it can +attack the first 100 of the 13 + + align:start position:0% +attack the first 100 of the 13 + + + align:start position:0% +attack the first 100 of the 13 +phosphoglycerate and in the first step + + align:start position:0% +phosphoglycerate and in the first step + + + align:start position:0% +phosphoglycerate and in the first step +is just going to form a tetrahedral + + align:start position:0% +is just going to form a tetrahedral + + + align:start position:0% +is just going to form a tetrahedral +intermediate there you have it now we + + align:start position:0% +intermediate there you have it now we + + + align:start position:0% +intermediate there you have it now we +have a negative charge on + + align:start position:0% +have a negative charge on + + + align:start position:0% +have a negative charge on +on the oxygen and we spelled out the + + align:start position:0% +on the oxygen and we spelled out the + + + align:start position:0% +on the oxygen and we spelled out the +phosphate with all the atoms here all + + align:start position:0% +phosphate with all the atoms here all + + + align:start position:0% +phosphate with all the atoms here all +right as you know these tetrahedral + + align:start position:0% +right as you know these tetrahedral + + + align:start position:0% +right as you know these tetrahedral +intermediate is not going to fall apart + + align:start position:0% +intermediate is not going to fall apart + + + align:start position:0% +intermediate is not going to fall apart +releasing like the most the best leaving + + align:start position:0% +releasing like the most the best leaving + + + align:start position:0% +releasing like the most the best leaving +group in this case is going to be the + + align:start position:0% +group in this case is going to be the + + + align:start position:0% +group in this case is going to be the +inorganic phosphate select the electrons + + align:start position:0% +inorganic phosphate select the electrons + + + align:start position:0% +inorganic phosphate select the electrons +come down is going to be transferred + + align:start position:0% +come down is going to be transferred + + + align:start position:0% +come down is going to be transferred +onto the phosphate and presumably + + align:start position:0% +onto the phosphate and presumably + + + align:start position:0% +onto the phosphate and presumably +protonated we can alright so after the + + align:start position:0% +protonated we can alright so after the + + + align:start position:0% +protonated we can alright so after the +phosphate is released now we we have + + align:start position:0% +phosphate is released now we we have + + + align:start position:0% +phosphate is released now we we have +flown finally the tile ester of our + + align:start position:0% +flown finally the tile ester of our + + + align:start position:0% +flown finally the tile ester of our +substrate in the active side of gap th + + align:start position:0% +substrate in the active side of gap th + + + align:start position:0% +substrate in the active side of gap th +as you remember this is a redox + + align:start position:0% +as you remember this is a redox + + + align:start position:0% +as you remember this is a redox +reactions involve the cofactor nad in + + align:start position:0% +reactions involve the cofactor nad in + + + align:start position:0% +reactions involve the cofactor nad in +this case running the reaction from + + align:start position:0% +this case running the reaction from + + + align:start position:0% +this case running the reaction from +right to left we're going to use NADH to + + align:start position:0% +right to left we're going to use NADH to + + + align:start position:0% +right to left we're going to use NADH to +reduce the base phosphoglycerate to the + + align:start position:0% +reduce the base phosphoglycerate to the + + + align:start position:0% +reduce the base phosphoglycerate to the +aldehyde group so here is our + + align:start position:0% +aldehyde group so here is our + + + align:start position:0% +aldehyde group so here is our +representation of the NADH as you + + align:start position:0% +representation of the NADH as you + + + align:start position:0% +representation of the NADH as you +remember one of these hydrogen's + + align:start position:0% +remember one of these hydrogen's + + + align:start position:0% +remember one of these hydrogen's +together with its electron pair it's + + align:start position:0% +together with its electron pair it's + + + align:start position:0% +together with its electron pair it's +going to be donated as a hydride or h- + + align:start position:0% +going to be donated as a hydride or h- + + + align:start position:0% +going to be donated as a hydride or h- +all right so this the reaction proceeds + + align:start position:0% +all right so this the reaction proceeds + + + align:start position:0% +all right so this the reaction proceeds +by rearranging the electrons on the + + align:start position:0% +by rearranging the electrons on the + + + align:start position:0% +by rearranging the electrons on the +pyridine ring of nad and the h minus is + + align:start position:0% +pyridine ring of nad and the h minus is + + + align:start position:0% +pyridine ring of nad and the h minus is +going to be the nucleophile that's + + align:start position:0% +going to be the nucleophile that's + + + align:start position:0% +going to be the nucleophile that's +attacking now but I Lester once again + + align:start position:0% +attacking now but I Lester once again + + + align:start position:0% +attacking now but I Lester once again +I'm going to be forming a tetrahedral + + align:start position:0% +I'm going to be forming a tetrahedral + + + align:start position:0% +I'm going to be forming a tetrahedral +intermediate which is shown here now + + align:start position:0% +intermediate which is shown here now + + + align:start position:0% +intermediate which is shown here now +this hydride here is the one that came + + align:start position:0% +this hydride here is the one that came + + + align:start position:0% +this hydride here is the one that came +from nadh and in the process the NADH + + align:start position:0% +from nadh and in the process the NADH + + + align:start position:0% +from nadh and in the process the NADH +cofactor is converted to NAD+ alright so + + align:start position:0% +cofactor is converted to NAD+ alright so + + + align:start position:0% +cofactor is converted to NAD+ alright so +now we can see we're just one step away + + align:start position:0% +now we can see we're just one step away + + + align:start position:0% +now we can see we're just one step away +this is now a like a hemiacetal like + + align:start position:0% +this is now a like a hemiacetal like + + + align:start position:0% +this is now a like a hemiacetal like +molecule so it's one step away from + + align:start position:0% +molecule so it's one step away from + + + align:start position:0% +molecule so it's one step away from +forming glyceraldehyde-3-phosphate all + + align:start position:0% +forming glyceraldehyde-3-phosphate all + + + align:start position:0% +forming glyceraldehyde-3-phosphate all +we need to do is release the enzyme in + + align:start position:0% +we need to do is release the enzyme in + + + align:start position:0% +we need to do is release the enzyme in +its original confirmation so the + + align:start position:0% +its original confirmation so the + + + align:start position:0% +its original confirmation so the +electrons will flow now to reform the + + align:start position:0% +electrons will flow now to reform the + + + align:start position:0% +electrons will flow now to reform the +carbonyl while the sulfur is going to + + align:start position:0% +carbonyl while the sulfur is going to + + + align:start position:0% +carbonyl while the sulfur is going to +get its electrons from the base and + + align:start position:0% +get its electrons from the base and + + + align:start position:0% +get its electrons from the base and +and this regenerates the enzyme as we + + align:start position:0% +and this regenerates the enzyme as we + + + align:start position:0% +and this regenerates the enzyme as we +had it in the beginning and we're + + align:start position:0% +had it in the beginning and we're + + + align:start position:0% +had it in the beginning and we're +releasing gap the product of the + + align:start position:0% +releasing gap the product of the + + + align:start position:0% +releasing gap the product of the +reaction so with this mechanistic + + align:start position:0% +reaction so with this mechanistic + + + align:start position:0% +reaction so with this mechanistic +insight we have actually addressed how + + align:start position:0% +insight we have actually addressed how + + + align:start position:0% +insight we have actually addressed how +the gap th reaction runs in the + + align:start position:0% +the gap th reaction runs in the + + + align:start position:0% +the gap th reaction runs in the +gluconeogenic mode from 13 bits + + align:start position:0% +gluconeogenic mode from 13 bits + + + align:start position:0% +gluconeogenic mode from 13 bits +phosphoglycerate to gap now part a of + + align:start position:0% +phosphoglycerate to gap now part a of + + + align:start position:0% +phosphoglycerate to gap now part a of +the problem also asked us to look up the + + align:start position:0% +the problem also asked us to look up the + + + align:start position:0% +the problem also asked us to look up the +free energy value for the aldolase + + align:start position:0% +free energy value for the aldolase + + + align:start position:0% +free energy value for the aldolase +reaction that is the Delta G naught + + align:start position:0% +reaction that is the Delta G naught + + + align:start position:0% +reaction that is the Delta G naught +prime now if you're going to look in + + align:start position:0% +prime now if you're going to look in + + + align:start position:0% +prime now if you're going to look in +your favorite chemistry textbook or I + + align:start position:0% +your favorite chemistry textbook or I + + + align:start position:0% +your favorite chemistry textbook or I +have here the fold and vote third + + align:start position:0% +have here the fold and vote third + + + align:start position:0% +have here the fold and vote third +edition the book that we use in in this + + align:start position:0% +edition the book that we use in in this + + + align:start position:0% +edition the book that we use in in this +course now you're going to find in on + + align:start position:0% +course now you're going to find in on + + + align:start position:0% +course now you're going to find in on +page 511 you're going to see a table + + align:start position:0% +page 511 you're going to see a table + + + align:start position:0% +page 511 you're going to see a table +with all the free energies of glycolysis + + align:start position:0% +with all the free energies of glycolysis + + + align:start position:0% +with all the free energies of glycolysis +reactions and for the aldolase tab + + align:start position:0% +reactions and for the aldolase tab + + + align:start position:0% +reactions and for the aldolase tab +you're going to see that it's a positive + + align:start position:0% +you're going to see that it's a positive + + + align:start position:0% +you're going to see that it's a positive +free energy that is the reaction + + align:start position:0% +free energy that is the reaction + + + align:start position:0% +free energy that is the reaction +spontaneous in the reverse in the + + align:start position:0% +spontaneous in the reverse in the + + + align:start position:0% +spontaneous in the reverse in the +gluconeogenic direction so now that that + + align:start position:0% +gluconeogenic direction so now that that + + + align:start position:0% +gluconeogenic direction so now that that +may be a little surprising but keep in + + align:start position:0% +may be a little surprising but keep in + + + align:start position:0% +may be a little surprising but keep in +mind that the reactions in these + + align:start position:0% +mind that the reactions in these + + + align:start position:0% +mind that the reactions in these +pathways are more often than not + + align:start position:0% +pathways are more often than not + + + align:start position:0% +pathways are more often than not +governed by mass action that is if we + + align:start position:0% +governed by mass action that is if we + + + align:start position:0% +governed by mass action that is if we +have an excess of the starting materials + + align:start position:0% +have an excess of the starting materials + + + align:start position:0% +have an excess of the starting materials +the reaction will proceed towards the + + align:start position:0% +the reaction will proceed towards the + + + align:start position:0% +the reaction will proceed towards the +product while if you have an excess of + + align:start position:0% +product while if you have an excess of + + + align:start position:0% +product while if you have an excess of +the products the reaction will proceed + + align:start position:0% +the products the reaction will proceed + + + align:start position:0% +the products the reaction will proceed +backwards towards the starting materials + + align:start position:0% +backwards towards the starting materials + + + align:start position:0% +backwards towards the starting materials +so both the aldolase reaction and the + + align:start position:0% +so both the aldolase reaction and the + + + align:start position:0% +so both the aldolase reaction and the +gap dehydrogenase reactions are very + + align:start position:0% +gap dehydrogenase reactions are very + + + align:start position:0% +gap dehydrogenase reactions are very +susceptible to this mass action so they + + align:start position:0% +susceptible to this mass action so they + + + align:start position:0% +susceptible to this mass action so they +will be controlled the direction the + + align:start position:0% +will be controlled the direction the + + + align:start position:0% +will be controlled the direction the +spontaneity of this reaction will be + + align:start position:0% +spontaneity of this reaction will be + + + align:start position:0% +spontaneity of this reaction will be +controlled by which of the starting + + align:start position:0% +controlled by which of the starting + + + align:start position:0% +controlled by which of the starting +materials or products are in excess + + align:start position:0% + + + + align:start position:0% + +Part C of this problem asked us to + + align:start position:0% +Part C of this problem asked us to + + + align:start position:0% +Part C of this problem asked us to +evaluate the spontaneity of + + align:start position:0% +evaluate the spontaneity of + + + align:start position:0% +evaluate the spontaneity of +gluconeogenesis at the level of the + + align:start position:0% +gluconeogenesis at the level of the + + + align:start position:0% +gluconeogenesis at the level of the +whole pathway now we know glycolysis is + + align:start position:0% +whole pathway now we know glycolysis is + + + align:start position:0% +whole pathway now we know glycolysis is +a spontaneous process not only it it + + align:start position:0% +a spontaneous process not only it it + + + align:start position:0% +a spontaneous process not only it it +occurs from goes from glucose to + + align:start position:0% +occurs from goes from glucose to + + + align:start position:0% +occurs from goes from glucose to +pyruvate but it also it generates some + + align:start position:0% +pyruvate but it also it generates some + + + align:start position:0% +pyruvate but it also it generates some +high-energy intermediates like ATP in + + align:start position:0% +high-energy intermediates like ATP in + + + align:start position:0% +high-energy intermediates like ATP in +the process I will get two molecules of + + align:start position:0% +the process I will get two molecules of + + + align:start position:0% +the process I will get two molecules of +ATP per glucose now if we want to go + + align:start position:0% +ATP per glucose now if we want to go + + + align:start position:0% +ATP per glucose now if we want to go +backwards from pyruvate to glucose in a + + align:start position:0% +backwards from pyruvate to glucose in a + + + align:start position:0% +backwards from pyruvate to glucose in a +gluconeogenesis pathway can this process + + align:start position:0% +gluconeogenesis pathway can this process + + + align:start position:0% +gluconeogenesis pathway can this process +be spontaneous first let's look at + + align:start position:0% +be spontaneous first let's look at + + + align:start position:0% +be spontaneous first let's look at +glycolysis here is a schematic of + + align:start position:0% +glycolysis here is a schematic of + + + align:start position:0% +glycolysis here is a schematic of +glycolysis we're starting here from + + align:start position:0% +glycolysis we're starting here from + + + align:start position:0% +glycolysis we're starting here from +glucose and we're going to need a couple + + align:start position:0% +glucose and we're going to need a couple + + + align:start position:0% +glucose and we're going to need a couple +of molecules of ATP to activate it to + + align:start position:0% +of molecules of ATP to activate it to + + + align:start position:0% +of molecules of ATP to activate it to +get to fructose 1 6 bisphosphate and + + align:start position:0% +get to fructose 1 6 bisphosphate and + + + align:start position:0% +get to fructose 1 6 bisphosphate and +from there on we're going to generate + + align:start position:0% +from there on we're going to generate + + + align:start position:0% +from there on we're going to generate +actually two molecules of ATP at this + + align:start position:0% +actually two molecules of ATP at this + + + align:start position:0% +actually two molecules of ATP at this +step and then two molecules of ATP at + + align:start position:0% +step and then two molecules of ATP at + + + align:start position:0% +step and then two molecules of ATP at +the final part of the kinase step and of + + align:start position:0% +the final part of the kinase step and of + + + align:start position:0% +the final part of the kinase step and of +course we're also going to need an nad + + align:start position:0% +course we're also going to need an nad + + + align:start position:0% +course we're also going to need an nad +plus going to NADH here at the gap step + + align:start position:0% +plus going to NADH here at the gap step + + + align:start position:0% +plus going to NADH here at the gap step +well there's going to be two of these + + align:start position:0% +well there's going to be two of these + + + align:start position:0% +well there's going to be two of these +NAD+ needed to oxidize gap to 1 through + + align:start position:0% +NAD+ needed to oxidize gap to 1 through + + + align:start position:0% +NAD+ needed to oxidize gap to 1 through +peaceful for glycerin all right and as + + align:start position:0% +peaceful for glycerin all right and as + + + align:start position:0% +peaceful for glycerin all right and as +we just said even though we have some + + align:start position:0% +we just said even though we have some + + + align:start position:0% +we just said even though we have some +energy costs in early on we're actually + + align:start position:0% +energy costs in early on we're actually + + + align:start position:0% +energy costs in early on we're actually +generating more ATP by the time we reach + + align:start position:0% +generating more ATP by the time we reach + + + align:start position:0% +generating more ATP by the time we reach +pyruvate so the pathway is in fact + + align:start position:0% +pyruvate so the pathway is in fact + + + align:start position:0% +pyruvate so the pathway is in fact +spontaneous now what about + + align:start position:0% +spontaneous now what about + + + align:start position:0% +spontaneous now what about +gluconeogenesis in google neurogenesis + + align:start position:0% +gluconeogenesis in google neurogenesis + + + align:start position:0% +gluconeogenesis in google neurogenesis +we're starting with pyruvate and we want + + align:start position:0% +we're starting with pyruvate and we want + + + align:start position:0% +we're starting with pyruvate and we want +to go back to glucose now if we were to + + align:start position:0% +to go back to glucose now if we were to + + + align:start position:0% +to go back to glucose now if we were to +reverse exactly every single step in + + align:start position:0% +reverse exactly every single step in + + + align:start position:0% +reverse exactly every single step in +glycolysis that price password is not + + align:start position:0% +glycolysis that price password is not + + + align:start position:0% +glycolysis that price password is not +going to be spontaneous so that for + + align:start position:0% +going to be spontaneous so that for + + + align:start position:0% +going to be spontaneous so that for +gluconeogenesis uses these alternate + + align:start position:0% +gluconeogenesis uses these alternate + + + align:start position:0% +gluconeogenesis uses these alternate +pathways and couple of the steps in + + align:start position:0% +pathways and couple of the steps in + + + align:start position:0% +pathways and couple of the steps in +order to make the process spontaneous + + align:start position:0% +order to make the process spontaneous + + + align:start position:0% +order to make the process spontaneous +for example going from pyruvate to + + align:start position:0% +for example going from pyruvate to + + + align:start position:0% +for example going from pyruvate to +phosphoenolpyruvate in gluconeogenesis + + align:start position:0% +phosphoenolpyruvate in gluconeogenesis + + + align:start position:0% +phosphoenolpyruvate in gluconeogenesis +is not a reverse of the fast part of it + + align:start position:0% +is not a reverse of the fast part of it + + + align:start position:0% +is not a reverse of the fast part of it +kinase reaction and rather occur since + + align:start position:0% +kinase reaction and rather occur since + + + align:start position:0% +kinase reaction and rather occur since +two steps the first step we take part of + + align:start position:0% +two steps the first step we take part of + + + align:start position:0% +two steps the first step we take part of +it and convert it to oxaloacetate using + + align:start position:0% +it and convert it to oxaloacetate using + + + align:start position:0% +it and convert it to oxaloacetate using +pyruvate carboxylase + + align:start position:0% +pyruvate carboxylase + + + align:start position:0% +pyruvate carboxylase +is going to going to need a molecule of + + align:start position:0% +is going to going to need a molecule of + + + align:start position:0% +is going to going to need a molecule of +co2 right oxaloacetate has four carbons + + align:start position:0% +co2 right oxaloacetate has four carbons + + + align:start position:0% +co2 right oxaloacetate has four carbons +and it's also going to need energy so + + align:start position:0% +and it's also going to need energy so + + + align:start position:0% +and it's also going to need energy so +we're going to need a molecule of ATP + + align:start position:0% +we're going to need a molecule of ATP + + + align:start position:0% +we're going to need a molecule of ATP +going to adp now oxaloacetate then can + + align:start position:0% +going to adp now oxaloacetate then can + + + align:start position:0% +going to adp now oxaloacetate then can +now be processed inside the mitochondria + + align:start position:0% +now be processed inside the mitochondria + + + align:start position:0% +now be processed inside the mitochondria +or it can be taken out of the + + align:start position:0% +or it can be taken out of the + + + align:start position:0% +or it can be taken out of the +mitochondria into the cytosol and let's + + align:start position:0% +mitochondria into the cytosol and let's + + + align:start position:0% +mitochondria into the cytosol and let's +say that's the course of the reaction + + align:start position:0% +say that's the course of the reaction + + + align:start position:0% +say that's the course of the reaction +where it's going to find an enzyme + + align:start position:0% +where it's going to find an enzyme + + + align:start position:0% +where it's going to find an enzyme +called PP carboxykinase or Pepsi k that + + align:start position:0% +called PP carboxykinase or Pepsi k that + + + align:start position:0% +called PP carboxykinase or Pepsi k that +can take off cell acetate to PP this + + align:start position:0% +can take off cell acetate to PP this + + + align:start position:0% +can take off cell acetate to PP this +enzyme once again requires energy this + + align:start position:0% +enzyme once again requires energy this + + + align:start position:0% +enzyme once again requires energy this +time the form of GTP goes to gdp and + + align:start position:0% +time the form of GTP goes to gdp and + + + align:start position:0% +time the form of GTP goes to gdp and +here we're going to lose that carboxyl + + align:start position:0% +here we're going to lose that carboxyl + + + align:start position:0% +here we're going to lose that carboxyl +group that we added on earlier now while + + align:start position:0% +group that we added on earlier now while + + + align:start position:0% +group that we added on earlier now while +this might seem like a sort of a + + align:start position:0% +this might seem like a sort of a + + + align:start position:0% +this might seem like a sort of a +cumbersome way to reverse one reaction + + align:start position:0% +cumbersome way to reverse one reaction + + + align:start position:0% +cumbersome way to reverse one reaction +this allows both the part of it kinase + + align:start position:0% +this allows both the part of it kinase + + + align:start position:0% +this allows both the part of it kinase +reaction and going from pyruvate going + + align:start position:0% +reaction and going from pyruvate going + + + align:start position:0% +reaction and going from pyruvate going +back to PP to be controlled in different + + align:start position:0% +back to PP to be controlled in different + + + align:start position:0% +back to PP to be controlled in different +ways and therefore allow both of these + + align:start position:0% +ways and therefore allow both of these + + + align:start position:0% +ways and therefore allow both of these +processes to happen spontaneously the + + align:start position:0% +processes to happen spontaneously the + + + align:start position:0% +processes to happen spontaneously the +rest of gluconeogenesis will have + + align:start position:0% +rest of gluconeogenesis will have + + + align:start position:0% +rest of gluconeogenesis will have +exactly the reverse of these steps in + + align:start position:0% +exactly the reverse of these steps in + + + align:start position:0% +exactly the reverse of these steps in +glycolysis for example PP going to two + + align:start position:0% +glycolysis for example PP going to two + + + align:start position:0% +glycolysis for example PP going to two +phosphoglycerate the Fox will get her + + align:start position:0% +phosphoglycerate the Fox will get her + + + align:start position:0% +phosphoglycerate the Fox will get her +going to 3-phosphoglycerate + + align:start position:0% +going to 3-phosphoglycerate + + + align:start position:0% +going to 3-phosphoglycerate +3-phosphoglycerate going to 13 bits + + align:start position:0% +3-phosphoglycerate going to 13 bits + + + align:start position:0% +3-phosphoglycerate going to 13 bits +phosphoglycerate here since in + + align:start position:0% +phosphoglycerate here since in + + + align:start position:0% +phosphoglycerate here since in +glycolysis which generated ATP here + + align:start position:0% +glycolysis which generated ATP here + + + align:start position:0% +glycolysis which generated ATP here +we're going to need the ATP to come in + + align:start position:0% +we're going to need the ATP to come in + + + align:start position:0% +we're going to need the ATP to come in +and go to adp in order to accomplish the + + align:start position:0% +and go to adp in order to accomplish the + + + align:start position:0% +and go to adp in order to accomplish the +step in gluconeogenesis 13 bits 44 + + align:start position:0% +step in gluconeogenesis 13 bits 44 + + + align:start position:0% +step in gluconeogenesis 13 bits 44 +glyceride going to gap this is the step + + align:start position:0% +glyceride going to gap this is the step + + + align:start position:0% +glyceride going to gap this is the step +we'll just discussed in part two of the + + align:start position:0% +we'll just discussed in part two of the + + + align:start position:0% +we'll just discussed in part two of the +problem as we said we're going to need + + align:start position:0% +problem as we said we're going to need + + + align:start position:0% +problem as we said we're going to need +NADH going to NAD+ then gap and DHAP + + align:start position:0% +NADH going to NAD+ then gap and DHAP + + + align:start position:0% +NADH going to NAD+ then gap and DHAP +going to fructose 1 6 bisphosphate this + + align:start position:0% +going to fructose 1 6 bisphosphate this + + + align:start position:0% +going to fructose 1 6 bisphosphate this +is the step we discussed in part a of + + align:start position:0% +is the step we discussed in part a of + + + align:start position:0% +is the step we discussed in part a of +this problem the reverse of the aldolase + + align:start position:0% +this problem the reverse of the aldolase + + + align:start position:0% +this problem the reverse of the aldolase +reaction no going from fructose 1 6 bit + + align:start position:0% +reaction no going from fructose 1 6 bit + + + align:start position:0% +reaction no going from fructose 1 6 bit +faster + + align:start position:0% +faster + + + align:start position:0% +faster +to glucose we're not going to do these + + align:start position:0% +to glucose we're not going to do these + + + align:start position:0% +to glucose we're not going to do these +kinase reactions in Reverse where would + + align:start position:0% +kinase reactions in Reverse where would + + + align:start position:0% +kinase reactions in Reverse where would +be generating ATP and therefore there + + align:start position:0% +be generating ATP and therefore there + + + align:start position:0% +be generating ATP and therefore there +would be not spontaneous in the reverse + + align:start position:0% +would be not spontaneous in the reverse + + + align:start position:0% +would be not spontaneous in the reverse +direction but rather we're going to use + + align:start position:0% +direction but rather we're going to use + + + align:start position:0% +direction but rather we're going to use +alternate enzymes called phosphatases + + align:start position:0% +alternate enzymes called phosphatases + + + align:start position:0% +alternate enzymes called phosphatases +where we lose the phosphate without + + align:start position:0% +where we lose the phosphate without + + + align:start position:0% +where we lose the phosphate without +regenerating and ATP molecules so + + align:start position:0% +regenerating and ATP molecules so + + + align:start position:0% +regenerating and ATP molecules so +therefore by using these these two + + align:start position:0% +therefore by using these these two + + + align:start position:0% +therefore by using these these two +tricks we can go back to glucose without + + align:start position:0% +tricks we can go back to glucose without + + + align:start position:0% +tricks we can go back to glucose without +regenerating its ATP molecules and + + align:start position:0% +regenerating its ATP molecules and + + + align:start position:0% +regenerating its ATP molecules and +therefore the pathway can be spontaneous + + align:start position:0% +therefore the pathway can be spontaneous + + + align:start position:0% +therefore the pathway can be spontaneous +now the bottom line here is that both + + align:start position:0% +now the bottom line here is that both + + + align:start position:0% +now the bottom line here is that both +glycolysis and gluconeogenesis are + + align:start position:0% +glycolysis and gluconeogenesis are + + + align:start position:0% +glycolysis and gluconeogenesis are +spontaneous but gluconeogenesis uses + + align:start position:0% +spontaneous but gluconeogenesis uses + + + align:start position:0% +spontaneous but gluconeogenesis uses +most but not all of the glycolysis steps + + align:start position:0% +most but not all of the glycolysis steps + + + align:start position:0% +most but not all of the glycolysis steps +to run in reverse and while glycolysis + + align:start position:0% +to run in reverse and while glycolysis + + + align:start position:0% +to run in reverse and while glycolysis +generates energy we'd get a net of two + + align:start position:0% +generates energy we'd get a net of two + + + align:start position:0% +generates energy we'd get a net of two +molecules of ATP per molecule of glucose + + align:start position:0% +molecules of ATP per molecule of glucose + + + align:start position:0% +molecules of ATP per molecule of glucose +used gluconeogenesis as you guys seen + + align:start position:0% +used gluconeogenesis as you guys seen + + + align:start position:0% +used gluconeogenesis as you guys seen +I've seen here actually uses energy to + + align:start position:0% +I've seen here actually uses energy to + + + align:start position:0% +I've seen here actually uses energy to +run if spontaneously that is we need ATP + + align:start position:0% +run if spontaneously that is we need ATP + + + align:start position:0% +run if spontaneously that is we need ATP +molecules now if you look at our diagram + + align:start position:0% +molecules now if you look at our diagram + + + align:start position:0% +molecules now if you look at our diagram +we need ATP molecules to convert + + align:start position:0% +we need ATP molecules to convert + + + align:start position:0% +we need ATP molecules to convert +pyruvate to phosphoenolpyruvate actually + + align:start position:0% +pyruvate to phosphoenolpyruvate actually + + + align:start position:0% +pyruvate to phosphoenolpyruvate actually +two of them and then we're going to need + + align:start position:0% +two of them and then we're going to need + + + align:start position:0% +two of them and then we're going to need +more ATP here to form 13 bits + + align:start position:0% +more ATP here to form 13 bits + + + align:start position:0% +more ATP here to form 13 bits +phosphoglycerate in addition to the + + align:start position:0% +phosphoglycerate in addition to the + + + align:start position:0% +phosphoglycerate in addition to the +redox like NADH cofactor to run the gap + + align:start position:0% +redox like NADH cofactor to run the gap + + + align:start position:0% +redox like NADH cofactor to run the gap +dehydrogenase reaction in Reverse so + + align:start position:0% +dehydrogenase reaction in Reverse so + + + align:start position:0% +dehydrogenase reaction in Reverse so +given these considerations + + align:start position:0% +given these considerations + + + align:start position:0% +given these considerations +gluconeogenesis is in fact spontaneous + + align:start position:0% +gluconeogenesis is in fact spontaneous + + + align:start position:0% +gluconeogenesis is in fact spontaneous +but it's going to cost us several ATP + + align:start position:0% +but it's going to cost us several ATP + + + align:start position:0% +but it's going to cost us several ATP +equivalents while glycolysis are + + align:start position:0% +equivalents while glycolysis are + + + align:start position:0% +equivalents while glycolysis are +spontaneous and generate ATP well that + + align:start position:0% +spontaneous and generate ATP well that + + + align:start position:0% +spontaneous and generate ATP well that +solves problem 3 or problems at 10 here + + align:start position:0% +solves problem 3 or problems at 10 here + + + align:start position:0% +solves problem 3 or problems at 10 here +I hope you've got a better understanding + + align:start position:0% +I hope you've got a better understanding + + + align:start position:0% +I hope you've got a better understanding +of why both glycolysis and + + align:start position:0% +of why both glycolysis and + + + align:start position:0% +of why both glycolysis and +gluconeogenesis are both spontaneous + + align:start position:0% +gluconeogenesis are both spontaneous + + + align:start position:0% +gluconeogenesis are both spontaneous +pathways inside the cell thank you \ No newline at end of file diff --git a/zqks_JcU0cM.txt b/zqks_JcU0cM.txt new file mode 100644 index 0000000000000000000000000000000000000000..763f28a6834cc4ec6b7b4ce0acdde8ac44403a8d --- /dev/null +++ b/zqks_JcU0cM.txt @@ -0,0 +1,1955 @@ +align:start position:0% + +Okay. So today is unforced that means + + align:start position:0% +Okay. So today is unforced that means + + + align:start position:0% +Okay. So today is unforced that means +zero on the right hand side looking for + + align:start position:0% +zero on the right hand side looking for + + + align:start position:0% +zero on the right hand side looking for +null solutions. Damped that means + + align:start position:0% +null solutions. Damped that means + + + align:start position:0% +null solutions. Damped that means +there's a coefficient B in the first + + align:start position:0% +there's a coefficient B in the first + + + align:start position:0% +there's a coefficient B in the first +derivative. And what's the solution? + + align:start position:0% +derivative. And what's the solution? + + + align:start position:0% +derivative. And what's the solution? +This is really a basic basic equation. + + align:start position:0% +This is really a basic basic equation. + + + align:start position:0% +This is really a basic basic equation. +Uh in in many applications a would be + + align:start position:0% +Uh in in many applications a would be + + + align:start position:0% +Uh in in many applications a would be +the mass in in a spring for example. A + + align:start position:0% +the mass in in a spring for example. A + + + align:start position:0% +the mass in in a spring for example. A +would be a mass. B is the damping, the + + align:start position:0% +would be a mass. B is the damping, the + + + align:start position:0% +would be a mass. B is the damping, the +friction. And C is the spring constant, + + align:start position:0% +friction. And C is the spring constant, + + + align:start position:0% +friction. And C is the spring constant, +the force that pulls the mass back. Or + + align:start position:0% +the force that pulls the mass back. Or + + + align:start position:0% +the force that pulls the mass back. Or +in electronics, B would be the + + align:start position:0% +in electronics, B would be the + + + align:start position:0% +in electronics, B would be the +resistance. It's giving some friction, + + align:start position:0% +resistance. It's giving some friction, + + + align:start position:0% +resistance. It's giving some friction, +giving some heat. So that's our + + align:start position:0% +giving some heat. So that's our + + + align:start position:0% +giving some heat. So that's our +equation. Just we have to be able to + + align:start position:0% +equation. Just we have to be able to + + + align:start position:0% +equation. Just we have to be able to +solve it. And we want we want to look + + align:start position:0% +solve it. And we want we want to look + + + align:start position:0% +solve it. And we want we want to look +for exponentials. + + align:start position:0% +for exponentials. + + + align:start position:0% +for exponentials. +A pure exponential is just right for + + align:start position:0% +A pure exponential is just right for + + + align:start position:0% +A pure exponential is just right for +constant coefficient equation like that. + + align:start position:0% +constant coefficient equation like that. + + + align:start position:0% +constant coefficient equation like that. +So I'll substitute y equals e to the s + + align:start position:0% +So I'll substitute y equals e to the s + + + align:start position:0% +So I'll substitute y equals e to the s +t. And what happens? + + align:start position:0% +t. And what happens? + + + align:start position:0% +t. And what happens? +Well, so there's a c e to the s t. + + align:start position:0% +Well, so there's a c e to the s t. + + + align:start position:0% +Well, so there's a c e to the s t. +That's the c y. The derivative brings + + align:start position:0% +That's the c y. The derivative brings + + + align:start position:0% +That's the c y. The derivative brings +down an s. Two derivatives bring down s + + align:start position:0% +down an s. Two derivatives bring down s + + + align:start position:0% +down an s. Two derivatives bring down s +squared. So I simply have a s^2 bs and c + + align:start position:0% +squared. So I simply have a s^2 bs and c + + + align:start position:0% +squared. So I simply have a s^2 bs and c +all together multiplying + + align:start position:0% +all together multiplying + + + align:start position:0% +all together multiplying +e to the s t + + align:start position:0% +e to the s t + + + align:start position:0% +e to the s t +and how do I get zero? Well the zero is + + align:start position:0% +and how do I get zero? Well the zero is + + + align:start position:0% +and how do I get zero? Well the zero is +not going to come from e to the st. So + + align:start position:0% +not going to come from e to the st. So + + + align:start position:0% +not going to come from e to the st. So +it has to come from this. So + + align:start position:0% +it has to come from this. So + + + align:start position:0% +it has to come from this. So +fundamentally the whole video and more + + align:start position:0% +fundamentally the whole video and more + + + align:start position:0% +fundamentally the whole video and more +is about a quadratic equation + + align:start position:0% +is about a quadratic equation + + + align:start position:0% +is about a quadratic equation +a s^2 + b s + c equals z. That's we have + + align:start position:0% +a s^2 + b s + c equals z. That's we have + + + align:start position:0% +a s^2 + b s + c equals z. That's we have +to solve it. We have to understand how + + align:start position:0% +to solve it. We have to understand how + + + align:start position:0% +to solve it. We have to understand how +does the answer depend on these numbers + + align:start position:0% +does the answer depend on these numbers + + + align:start position:0% +does the answer depend on these numbers +a and b and c the constants. + + align:start position:0% +a and b and c the constants. + + + align:start position:0% +a and b and c the constants. +Okay. So we know the root, we know the + + align:start position:0% +Okay. So we know the root, we know the + + + align:start position:0% +Okay. So we know the root, we know the +solutions. The quadratic formula tells + + align:start position:0% +solutions. The quadratic formula tells + + + align:start position:0% +solutions. The quadratic formula tells +us that the two solutions, they're + + align:start position:0% +us that the two solutions, they're + + + align:start position:0% +us that the two solutions, they're +always two, but they could be equal. Uh + + align:start position:0% +always two, but they could be equal. Uh + + + align:start position:0% +always two, but they could be equal. Uh +have this do do you recognize this + + align:start position:0% +have this do do you recognize this + + + align:start position:0% +have this do do you recognize this +expression + + align:start position:0% +expression + + + align:start position:0% +expression +uh the the you see the damping + + align:start position:0% +uh the the you see the damping + + + align:start position:0% +uh the the you see the damping +coefficient coming in. You see this + + align:start position:0% +coefficient coming in. You see this + + + align:start position:0% +coefficient coming in. You see this +allimp important square root which tells + + align:start position:0% +allimp important square root which tells + + + align:start position:0% +allimp important square root which tells +us depending on whether b ^2 is bigger + + align:start position:0% +us depending on whether b ^2 is bigger + + + align:start position:0% +us depending on whether b ^2 is bigger +than 4 a c b ^2 is equal 4 a c b ^2 is + + align:start position:0% +than 4 a c b ^2 is equal 4 a c b ^2 is + + + align:start position:0% +than 4 a c b ^2 is equal 4 a c b ^2 is +smaller so smaller b means less damping + + align:start position:0% +smaller so smaller b means less damping + + + align:start position:0% +smaller so smaller b means less damping +and it would be called under damping. So + + align:start position:0% +and it would be called under damping. So + + + align:start position:0% +and it would be called under damping. So +here's the + + align:start position:0% +here's the + + + align:start position:0% +here's the +here are the possibilities. + + align:start position:0% +here are the possibilities. + + + align:start position:0% +here are the possibilities. +B could be zero. That puts us back in a + + align:start position:0% +B could be zero. That puts us back in a + + + align:start position:0% +B could be zero. That puts us back in a +previous + + align:start position:0% +previous + + + align:start position:0% +previous +video when the solution was a pure + + align:start position:0% +video when the solution was a pure + + + align:start position:0% +video when the solution was a pure +uh + + align:start position:0% +uh + + + align:start position:0% +uh +complex exponential pure sign cosine. + + align:start position:0% +complex exponential pure sign cosine. + + + align:start position:0% +complex exponential pure sign cosine. +There was no damping. It just oscillated + + align:start position:0% +There was no damping. It just oscillated + + + align:start position:0% +There was no damping. It just oscillated +forever. That's the one we know. Now the + + align:start position:0% +forever. That's the one we know. Now the + + + align:start position:0% +forever. That's the one we know. Now the +new ones with a b + + align:start position:0% +new ones with a b + + + align:start position:0% +new ones with a b +or b squared could be smaller than so + + align:start position:0% +or b squared could be smaller than so + + + align:start position:0% +or b squared could be smaller than so +that's only a little damping. + + align:start position:0% +that's only a little damping. + + + align:start position:0% +that's only a little damping. +And in that case, what does the solution + + align:start position:0% +And in that case, what does the solution + + + align:start position:0% +And in that case, what does the solution +look like? If b ^2 is smaller than 4 a + + align:start position:0% +look like? If b ^2 is smaller than 4 a + + + align:start position:0% +look like? If b ^2 is smaller than 4 a +c, I have to always look back here. So I + + align:start position:0% +c, I have to always look back here. So I + + + align:start position:0% +c, I have to always look back here. So I +have something negative, + + align:start position:0% +have something negative, + + + align:start position:0% +have something negative, +something negative, a minus b over 2 a + + align:start position:0% + + + + align:start position:0% + +and then plus or minus. And what's the + + align:start position:0% +and then plus or minus. And what's the + + + align:start position:0% +and then plus or minus. And what's the +important point about this guy? B ^2 is + + align:start position:0% +important point about this guy? B ^2 is + + + align:start position:0% +important point about this guy? B ^2 is +smaller than 4 a c. This is negative + + align:start position:0% +smaller than 4 a c. This is negative + + + align:start position:0% +smaller than 4 a c. This is negative +inside. So it square root is an + + align:start position:0% +inside. So it square root is an + + + align:start position:0% +inside. So it square root is an +imaginary number. So the plus or minus + + align:start position:0% +imaginary number. So the plus or minus + + + align:start position:0% +imaginary number. So the plus or minus +there's an imaginary number a little + + align:start position:0% +there's an imaginary number a little + + + align:start position:0% +there's an imaginary number a little +different from the natural frequency. + + align:start position:0% +different from the natural frequency. + + + align:start position:0% +different from the natural frequency. +It's called the damped frequency. + + align:start position:0% +It's called the damped frequency. + + + align:start position:0% +It's called the damped frequency. +Not quite as frequent. + + align:start position:0% +Not quite as frequent. + + + align:start position:0% +Not quite as frequent. +The damping slows the oscillation down a + + align:start position:0% +The damping slows the oscillation down a + + + align:start position:0% +The damping slows the oscillation down a +little bit but it brings in exponential + + align:start position:0% +little bit but it brings in exponential + + + align:start position:0% +little bit but it brings in exponential +decay. I'll draw a picture this time or + + align:start position:0% +decay. I'll draw a picture this time or + + + align:start position:0% +decay. I'll draw a picture this time or +next time about of the solution e to the + + align:start position:0% +next time about of the solution e to the + + + align:start position:0% +next time about of the solution e to the +minus s. But you see e to the minus s is + + align:start position:0% +minus s. But you see e to the minus s is + + + align:start position:0% +minus s. But you see e to the minus s is +decaying to zero. It's like a spring + + align:start position:0% +decaying to zero. It's like a spring + + + align:start position:0% +decaying to zero. It's like a spring +that's slowly + + align:start position:0% +that's slowly + + + align:start position:0% +that's slowly +winding down to zero, but it's + + align:start position:0% +winding down to zero, but it's + + + align:start position:0% +winding down to zero, but it's +oscillating as it does it. Okay, now + + align:start position:0% +oscillating as it does it. Okay, now + + + align:start position:0% +oscillating as it does it. Okay, now +we've got two more possibilities here. + + align:start position:0% +we've got two more possibilities here. + + + align:start position:0% +we've got two more possibilities here. +And these are just fun to get straight. + + align:start position:0% +And these are just fun to get straight. + + + align:start position:0% +And these are just fun to get straight. +There's the next one. When b ^2 is + + align:start position:0% +There's the next one. When b ^2 is + + + align:start position:0% +There's the next one. When b ^2 is +exactly 4 a c. Exactly 4 a. B ^2 over 4 + + align:start position:0% +exactly 4 a c. Exactly 4 a. B ^2 over 4 + + + align:start position:0% +exactly 4 a c. Exactly 4 a. B ^2 over 4 +a c. That's the going to be the critical + + align:start position:0% +a c. That's the going to be the critical + + + align:start position:0% +a c. That's the going to be the critical +ratio here. And here that ratio is one. + + align:start position:0% +ratio here. And here that ratio is one. + + + align:start position:0% +ratio here. And here that ratio is one. +And in that case that square root is + + align:start position:0% +And in that case that square root is + + + align:start position:0% +And in that case that square root is +nothing. The square root of B ^ 2 - 4 A + + align:start position:0% +nothing. The square root of B ^ 2 - 4 A + + + align:start position:0% +nothing. The square root of B ^ 2 - 4 A +C is zero. So we get S1 and S2 equal + + align:start position:0% +C is zero. So we get S1 and S2 equal + + + align:start position:0% +C is zero. So we get S1 and S2 equal +two equal frequencies real real numbers. + + align:start position:0% +two equal frequencies real real numbers. + + + align:start position:0% +two equal frequencies real real numbers. +The B there the minus B over 2A. So, so + + align:start position:0% +The B there the minus B over 2A. So, so + + + align:start position:0% +The B there the minus B over 2A. So, so +s_sub_1 and sub_2 + + align:start position:0% +s_sub_1 and sub_2 + + + align:start position:0% +s_sub_1 and sub_2 +are both minus b over 2a. + + align:start position:0% + + + + align:start position:0% + +That's a just the edge between x between + + align:start position:0% +That's a just the edge between x between + + + align:start position:0% +That's a just the edge between x between +the decay uh with oscillation from under + + align:start position:0% +the decay uh with oscillation from under + + + align:start position:0% +the decay uh with oscillation from under +damping and the opposite extreme is over + + align:start position:0% +damping and the opposite extreme is over + + + align:start position:0% +damping and the opposite extreme is over +damping. over damping when b ^2 is + + align:start position:0% +damping. over damping when b ^2 is + + + align:start position:0% +damping. over damping when b ^2 is +bigger than 4 a c then our formula we're + + align:start position:0% +bigger than 4 a c then our formula we're + + + align:start position:0% +bigger than 4 a c then our formula we're +always looking back at that quadratic + + align:start position:0% +always looking back at that quadratic + + + align:start position:0% +always looking back at that quadratic +formula b ^2 bigger than 4 a c this is + + align:start position:0% +formula b ^2 bigger than 4 a c this is + + + align:start position:0% +formula b ^2 bigger than 4 a c this is +real + + align:start position:0% +real + + + align:start position:0% +real +square root of a positive number it's + + align:start position:0% +square root of a positive number it's + + + align:start position:0% +square root of a positive number it's +perfectly real so in that case we have + + align:start position:0% +perfectly real so in that case we have + + + align:start position:0% +perfectly real so in that case we have +two s1 and sub_2 oh I let me draw you + + align:start position:0% +two s1 and sub_2 oh I let me draw you + + + align:start position:0% +two s1 and sub_2 oh I let me draw you +some pictures just I'll draw you the + + align:start position:0% +some pictures just I'll draw you the + + + align:start position:0% +some pictures just I'll draw you the +parabola the the the the a s^ squ. So + + align:start position:0% +parabola the the the the a s^ squ. So + + + align:start position:0% +parabola the the the the a s^ squ. So +this is a graph of a s2. + + align:start position:0% +this is a graph of a s2. + + + align:start position:0% +this is a graph of a s2. +Let let me draw + + align:start position:0% + + + + align:start position:0% + +plot a s^2 plus b s + c. So in this + + align:start position:0% +plot a s^2 plus b s + c. So in this + + + align:start position:0% +plot a s^2 plus b s + c. So in this +overdamping case we might have a lot of + + align:start position:0% +overdamping case we might have a lot of + + + align:start position:0% +overdamping case we might have a lot of +damping. B is pretty large and and the + + align:start position:0% +damping. B is pretty large and and the + + + align:start position:0% +damping. B is pretty large and and the +there is that would be a this direction + + align:start position:0% +there is that would be a this direction + + + align:start position:0% +there is that would be a this direction +is S and I'm graphing here + + align:start position:0% +is S and I'm graphing here + + + align:start position:0% +is S and I'm graphing here +S squared + + align:start position:0% +S squared + + + align:start position:0% +S squared +plus well let me see if I + + align:start position:0% +plus well let me see if I + + + align:start position:0% +plus well let me see if I +I think probably plus 2 S and now I'm + + align:start position:0% +I think probably plus 2 S and now I'm + + + align:start position:0% +I think probably plus 2 S and now I'm +going to choose this ah actually + + align:start position:0% +going to choose this ah actually + + + align:start position:0% +going to choose this ah actually +plus zero to get that one. So this has a + + align:start position:0% +plus zero to get that one. So this has a + + + align:start position:0% +plus zero to get that one. So this has a +root at this is over damping over + + align:start position:0% +root at this is over damping over + + + align:start position:0% +root at this is over damping over +damping + + align:start position:0% + + + + align:start position:0% + +a big number there. + + align:start position:0% +a big number there. + + + align:start position:0% +a big number there. +C is zero. No mass at all. No stiffness + + align:start position:0% +C is zero. No mass at all. No stiffness + + + align:start position:0% +C is zero. No mass at all. No stiffness +at all. No stiffness at all. So the the + + align:start position:0% +at all. No stiffness at all. So the the + + + align:start position:0% +at all. No stiffness at all. So the the +this parabola it has a has a root at + + align:start position:0% +this parabola it has a has a root at + + + align:start position:0% +this parabola it has a has a root at +zero and a root at minus2. + + align:start position:0% +zero and a root at minus2. + + + align:start position:0% +zero and a root at minus2. +That would be an extreme case with no + + align:start position:0% +That would be an extreme case with no + + + align:start position:0% +That would be an extreme case with no +stiffness whatever. Now let me add up + + align:start position:0% +stiffness whatever. Now let me add up + + + align:start position:0% +stiffness whatever. Now let me add up +add some stiffness. So what happens if I + + align:start position:0% +add some stiffness. So what happens if I + + + align:start position:0% +add some stiffness. So what happens if I +change the constant term? It lifts the + + align:start position:0% +change the constant term? It lifts the + + + align:start position:0% +change the constant term? It lifts the +graph. It lifts the graph. So let me + + align:start position:0% +graph. It lifts the graph. So let me + + + align:start position:0% +graph. It lifts the graph. So let me +make it one. So so I move the whole + + align:start position:0% +make it one. So so I move the whole + + + align:start position:0% +make it one. So so I move the whole +graph up by one. that moves. So you see + + align:start position:0% +graph up by one. that moves. So you see + + + align:start position:0% +graph up by one. that moves. So you see +that as I move it up, these roots will + + align:start position:0% +that as I move it up, these roots will + + + align:start position:0% +that as I move it up, these roots will +will c come closer and closer and at the + + align:start position:0% +will c come closer and closer and at the + + + align:start position:0% +will c come closer and closer and at the +right point when I move it up to one, + + align:start position:0% +right point when I move it up to one, + + + align:start position:0% +right point when I move it up to one, +what's going on there? + + align:start position:0% +what's going on there? + + + align:start position:0% +what's going on there? +Critical damping. Critical damping. This + + align:start position:0% +Critical damping. Critical damping. This + + + align:start position:0% +Critical damping. Critical damping. This +is the case s 2 + 2 s + 1 + + align:start position:0% + + + + align:start position:0% + +which is exactly s + 1 twice + + align:start position:0% +which is exactly s + 1 twice + + + align:start position:0% +which is exactly s + 1 twice +and it has that repeated root which we + + align:start position:0% +and it has that repeated root which we + + + align:start position:0% +and it has that repeated root which we +always recognize as the marginal case + + align:start position:0% +always recognize as the marginal case + + + align:start position:0% +always recognize as the marginal case +when it doesn't go bel it doesn't go + + align:start position:0% +when it doesn't go bel it doesn't go + + + align:start position:0% +when it doesn't go bel it doesn't go +below but it doesn't stay above either + + align:start position:0% +below but it doesn't stay above either + + + align:start position:0% +below but it doesn't stay above either +it hits here twice. So the root is + + align:start position:0% +it hits here twice. So the root is + + + align:start position:0% +it hits here twice. So the root is +minus1 twice. That's critical. And now + + align:start position:0% +minus1 twice. That's critical. And now + + + align:start position:0% +minus1 twice. That's critical. And now +what? + + align:start position:0% +what? + + + align:start position:0% +what? +Increase this constant C even further. + + align:start position:0% +Increase this constant C even further. + + + align:start position:0% +Increase this constant C even further. +You lift the graph, lift the parabola up + + align:start position:0% +You lift the graph, lift the parabola up + + + align:start position:0% +You lift the graph, lift the parabola up +here. Lift it by one more, let's say. + + align:start position:0% +here. Lift it by one more, let's say. + + + align:start position:0% +here. Lift it by one more, let's say. +And what's going on there? So that would + + align:start position:0% +And what's going on there? So that would + + + align:start position:0% +And what's going on there? So that would +be this would be s^2 + 2 s + 2. + + align:start position:0% +be this would be s^2 + 2 s + 2. + + + align:start position:0% +be this would be s^2 + 2 s + 2. +And you see what + + align:start position:0% +And you see what + + + align:start position:0% +And you see what +that graph is telling us. + + align:start position:0% +that graph is telling us. + + + align:start position:0% +that graph is telling us. +It's telling us there are no roots. No + + align:start position:0% +It's telling us there are no roots. No + + + align:start position:0% +It's telling us there are no roots. No +real roots. This is a real graph in the + + align:start position:0% +real roots. This is a real graph in the + + + align:start position:0% +real roots. This is a real graph in the +real plane and it never it's never zero. + + align:start position:0% +real plane and it never it's never zero. + + + align:start position:0% +real plane and it never it's never zero. +This is s + one. This is the under + + align:start position:0% +This is s + one. This is the under + + + align:start position:0% +This is s + one. This is the under +the uh this is the case when I have s + + align:start position:0% +the uh this is the case when I have s + + + align:start position:0% +the uh this is the case when I have s ++ 1 + + align:start position:0% ++ 1 + + + align:start position:0% ++ 1 +squared + 1 never never can't be zero + + align:start position:0% +squared + 1 never never can't be zero + + + align:start position:0% +squared + 1 never never can't be zero +never zero so this has uh + + align:start position:0% +never zero so this has uh + + + align:start position:0% +never zero so this has uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +sorry with the two there I it has + + align:start position:0% +sorry with the two there I it has + + + align:start position:0% +sorry with the two there I it has +damping + + align:start position:0% +damping + + + align:start position:0% +damping +It has damping but + + align:start position:0% +It has damping but + + + align:start position:0% +It has damping but +it it's under damping. The roots are + + align:start position:0% +it it's under damping. The roots are + + + align:start position:0% +it it's under damping. The roots are +complex. So, so this s S1 + 1^2 is zero. + + align:start position:0% +complex. So, so this s S1 + 1^2 is zero. + + + align:start position:0% +complex. So, so this s S1 + 1^2 is zero. +What are the roots of that? S is -1 + + align:start position:0% +What are the roots of that? S is -1 + + + align:start position:0% +What are the roots of that? S is -1 ++ or minus I. + + align:start position:0% ++ or minus I. + + + align:start position:0% ++ or minus I. +That's the + + align:start position:0% +That's the + + + align:start position:0% +That's the +that's the case of under damping. So, + + align:start position:0% +that's the case of under damping. So, + + + align:start position:0% +that's the case of under damping. So, +let me write that. + + align:start position:0% + + + + align:start position:0% + +we see so much from these graphs. So + + align:start position:0% +we see so much from these graphs. So + + + align:start position:0% +we see so much from these graphs. So +this was a graph in which I changed the + + align:start position:0% +this was a graph in which I changed the + + + align:start position:0% +this was a graph in which I changed the +constant term the capital C the the + + align:start position:0% +constant term the capital C the the + + + align:start position:0% +constant term the capital C the the +stiffness K K K K K K K K K K K K K K K + + align:start position:0% +stiffness K K K K K K K K K K K K K K K + + + align:start position:0% +stiffness K K K K K K K K K K K K K K K +K K K K K K K K K K K K K K K K K K K K + + align:start position:0% +K K K K K K K K K K K K K K K K K K K K + + + align:start position:0% +K K K K K K K K K K K K K K K K K K K K +K K K K K K that. So that lift lifted + + align:start position:0% +K K K K K K that. So that lift lifted + + + align:start position:0% +K K K K K K that. So that lift lifted +the graph and eventually the roots were + + align:start position:0% +the graph and eventually the roots were + + + align:start position:0% +the graph and eventually the roots were +complex. They weren't real anymore + + align:start position:0% +complex. They weren't real anymore + + + align:start position:0% +complex. They weren't real anymore +because the parabola didn't cross the + + align:start position:0% +because the parabola didn't cross the + + + align:start position:0% +because the parabola didn't cross the +axis anymore. + + align:start position:0% +axis anymore. + + + align:start position:0% +axis anymore. +the roots are where it crosses the axis. + + align:start position:0% +the roots are where it crosses the axis. + + + align:start position:0% +the roots are where it crosses the axis. +So that's uh one I'll I'll draw in the + + align:start position:0% +So that's uh one I'll I'll draw in the + + + align:start position:0% +So that's uh one I'll I'll draw in the +next video uh another picture maybe + + align:start position:0% +next video uh another picture maybe + + + align:start position:0% +next video uh another picture maybe +change B change the damping. So what + + align:start position:0% +change B change the damping. So what + + + align:start position:0% +change B change the damping. So what +would happen if I change the damping? If + + align:start position:0% +would happen if I change the damping? If + + + align:start position:0% +would happen if I change the damping? If +there's no damping, the roots are + + align:start position:0% +there's no damping, the roots are + + + align:start position:0% +there's no damping, the roots are +uh pure imaginary. Yeah, let let's just + + align:start position:0% +uh pure imaginary. Yeah, let let's just + + + align:start position:0% +uh pure imaginary. Yeah, let let's just +go back through those four possibilities + + align:start position:0% +go back through those four possibilities + + + align:start position:0% +go back through those four possibilities +because that's what you have to learn. + + align:start position:0% +because that's what you have to learn. + + + align:start position:0% +because that's what you have to learn. +If C if B is zero, there's no damping at + + align:start position:0% +If C if B is zero, there's no damping at + + + align:start position:0% +If C if B is zero, there's no damping at +all and we're back in the pure + + align:start position:0% +all and we're back in the pure + + + align:start position:0% +all and we're back in the pure +oscillation where where S is is pure + + align:start position:0% +oscillation where where S is is pure + + + align:start position:0% +oscillation where where S is is pure +imaginary. We're just seeing cosiness + + align:start position:0% +imaginary. We're just seeing cosiness + + + align:start position:0% +imaginary. We're just seeing cosiness +and signs. Then if we add a little + + align:start position:0% +and signs. Then if we add a little + + + align:start position:0% +and signs. Then if we add a little +damping + + align:start position:0% +damping + + + align:start position:0% +damping +there appears a decay term. If we had + + align:start position:0% +there appears a decay term. If we had + + + align:start position:0% +there appears a decay term. If we had +could let I could even draw the + + align:start position:0% +could let I could even draw the + + + align:start position:0% +could let I could even draw the +the these possibilities that draw draw + + align:start position:0% +the these possibilities that draw draw + + + align:start position:0% +the these possibilities that draw draw +let me draw the solution y of t y of t + + align:start position:0% +let me draw the solution y of t y of t + + + align:start position:0% +let me draw the solution y of t y of t +against t. + + align:start position:0% +against t. + + + align:start position:0% +against t. +Okay. So uh under damping the solution + + align:start position:0% +Okay. So uh under damping the solution + + + align:start position:0% +Okay. So uh under damping the solution +say it starts there will oscillate but + + align:start position:0% +say it starts there will oscillate but + + + align:start position:0% +say it starts there will oscillate but +decay. So this is under damping. + + align:start position:0% + + + + align:start position:0% + +And you remember what that when that h + + align:start position:0% +And you remember what that when that h + + + align:start position:0% +And you remember what that when that h +happens that's when B is present but + + align:start position:0% +happens that's when B is present but + + + align:start position:0% +happens that's when B is present but +smaller B ^2 is smaller than 4 AC + + align:start position:0% +smaller B ^2 is smaller than 4 AC + + + align:start position:0% +smaller B ^2 is smaller than 4 AC +over damping if it starts let's say here + + align:start position:0% +over damping if it starts let's say here + + + align:start position:0% +over damping if it starts let's say here +it will go to zero probably with no + + align:start position:0% +it will go to zero probably with no + + + align:start position:0% +it will go to zero probably with no +oscillation at all it could have one + + align:start position:0% +oscillation at all it could have one + + + align:start position:0% +oscillation at all it could have one +oscillation depends how it starts. So oo + + align:start position:0% +oscillation depends how it starts. So oo + + + align:start position:0% +oscillation depends how it starts. So oo +let me make this picture. So that one is + + align:start position:0% +let me make this picture. So that one is + + + align:start position:0% +let me make this picture. So that one is +the over damping. This guy is the + + align:start position:0% +the over damping. This guy is the + + + align:start position:0% +the over damping. This guy is the +underdamping. + + align:start position:0% +underdamping. + + + align:start position:0% +underdamping. +Under damping still has oscillations. + + align:start position:0% +Under damping still has oscillations. + + + align:start position:0% +Under damping still has oscillations. +Over damping has at most once could it + + align:start position:0% +Over damping has at most once could it + + + align:start position:0% +Over damping has at most once could it +could cross once but over damping is b^2 + + align:start position:0% +could cross once but over damping is b^2 + + + align:start position:0% +could cross once but over damping is b^2 +uh bigger than 4 a. + + align:start position:0% +uh bigger than 4 a. + + + align:start position:0% +uh bigger than 4 a. +Okay there's more to do. This is so + + align:start position:0% +Okay there's more to do. This is so + + + align:start position:0% +Okay there's more to do. This is so +central that that you have to think + + align:start position:0% +central that that you have to think + + + align:start position:0% +central that that you have to think +about the ratio of B^2 to 4 AC that has + + align:start position:0% +about the ratio of B^2 to 4 AC that has + + + align:start position:0% +about the ratio of B^2 to 4 AC that has +its own name and it's a damping fac + + align:start position:0% +its own name and it's a damping fac + + + align:start position:0% +its own name and it's a damping fac +damping ratio or the square of a damping + + align:start position:0% +damping ratio or the square of a damping + + + align:start position:0% +damping ratio or the square of a damping +ratio and and we identify all these + + align:start position:0% +ratio and and we identify all these + + + align:start position:0% +ratio and and we identify all these +solutions. + + align:start position:0% +solutions. + + + align:start position:0% +solutions. +Does everybody know where the solution + + align:start position:0% +Does everybody know where the solution + + + align:start position:0% +Does everybody know where the solution +will be when B is zero? No damping at + + align:start position:0% +will be when B is zero? No damping at + + + align:start position:0% +will be when B is zero? No damping at +all. In that case, it will just + + align:start position:0% +all. In that case, it will just + + + align:start position:0% +all. In that case, it will just +oscillate. + + align:start position:0% + + + + align:start position:0% + +So my picture is getting you could say a + + align:start position:0% +So my picture is getting you could say a + + + align:start position:0% +So my picture is getting you could say a +little messed up. But this pure + + align:start position:0% +little messed up. But this pure + + + align:start position:0% +little messed up. But this pure +oscillation would be the B equals Z with + + align:start position:0% +oscillation would be the B equals Z with + + + align:start position:0% +oscillation would be the B equals Z with +undamped. + + align:start position:0% + + + + align:start position:0% + +Okay, that's a first look at quadratic + + align:start position:0% +Okay, that's a first look at quadratic + + + align:start position:0% +Okay, that's a first look at quadratic +equations. A S^2 + B S + C. It has the + + align:start position:0% +equations. A S^2 + B S + C. It has the + + + align:start position:0% +equations. A S^2 + B S + C. It has the +big name characteristic equation, but + + align:start position:0% +big name characteristic equation, but + + + align:start position:0% +big name characteristic equation, but +you could see it's the fundamental + + align:start position:0% +you could see it's the fundamental + + + align:start position:0% +you could see it's the fundamental +equation for a second order uh + + align:start position:0% +equation for a second order uh + + + align:start position:0% +equation for a second order uh +differential equation. So we'll see more + + align:start position:0% +differential equation. So we'll see more + + + align:start position:0% +differential equation. So we'll see more +of it. Thanks. \ No newline at end of file diff --git a/zreI4HllD80.txt b/zreI4HllD80.txt new file mode 100644 index 0000000000000000000000000000000000000000..f10e9072cf278450d8061366c4e275ca5c06e99b --- /dev/null +++ b/zreI4HllD80.txt @@ -0,0 +1,7856 @@ +align:start position:0% + +we're + + align:start position:0% + + + + align:start position:0% + +going to need a few facts about + + align:start position:0% +going to need a few facts about + + + align:start position:0% +going to need a few facts about +fundamental matrices and I'm worried + + align:start position:0% +fundamental matrices and I'm worried + + + align:start position:0% +fundamental matrices and I'm worried +that over the weekend this spring + + align:start position:0% +that over the weekend this spring + + + align:start position:0% +that over the weekend this spring +activities weekend you might have + + align:start position:0% +activities weekend you might have + + + align:start position:0% +activities weekend you might have +forgotten them so I'll just spend two or + + align:start position:0% +forgotten them so I'll just spend two or + + + align:start position:0% +forgotten them so I'll just spend two or +three minutes reviewing the most + + align:start position:0% +three minutes reviewing the most + + + align:start position:0% +three minutes reviewing the most +essential things that we're going to + + align:start position:0% +essential things that we're going to + + + align:start position:0% +essential things that we're going to +need later in the period so what we're + + align:start position:0% +need later in the period so what we're + + + align:start position:0% +need later in the period so what we're +talking about is I'll try to color code + + align:start position:0% +talking about is I'll try to color code + + + align:start position:0% +talking about is I'll try to color code +things so you'll know what they are + + align:start position:0% +things so you'll know what they are + + + align:start position:0% +things so you'll know what they are +first of all where the basic problem is + + align:start position:0% +first of all where the basic problem is + + + align:start position:0% +first of all where the basic problem is +to solve a system of equations and I'm + + align:start position:0% +to solve a system of equations and I'm + + + align:start position:0% +to solve a system of equations and I'm +going to make that a two-by-two system + + align:start position:0% +going to make that a two-by-two system + + + align:start position:0% +going to make that a two-by-two system +although practically everything I say + + align:start position:0% +although practically everything I say + + + align:start position:0% +although practically everything I say +today will also work for n by n systems + + align:start position:0% +today will also work for n by n systems + + + align:start position:0% +today will also work for n by n systems +your book tries to do with n by n as + + align:start position:0% +your book tries to do with n by n as + + + align:start position:0% +your book tries to do with n by n as +usual but I think it's easier to learn + + align:start position:0% +usual but I think it's easier to learn + + + align:start position:0% +usual but I think it's easier to learn +two by two first and generalize rather + + align:start position:0% +two by two first and generalize rather + + + align:start position:0% +two by two first and generalize rather +than to wade through the complications + + align:start position:0% +than to wade through the complications + + + align:start position:0% +than to wade through the complications +of n by n system so the problem is to + + align:start position:0% +of n by n system so the problem is to + + + align:start position:0% +of n by n system so the problem is to +solve it and the method I used last time + + align:start position:0% +solve it and the method I used last time + + + align:start position:0% +solve it and the method I used last time +was to describe something called a + + align:start position:0% +was to describe something called a + + + align:start position:0% +was to describe something called a +fundamental matrix a fundamental + + align:start position:0% + + + + align:start position:0% + +matrix for the system of Caray whichever + + align:start position:0% +matrix for the system of Caray whichever + + + align:start position:0% +matrix for the system of Caray whichever +you want remember what that was that was + + align:start position:0% +you want remember what that was that was + + + align:start position:0% +you want remember what that was that was +something whose it was a two-by-two + + align:start position:0% +something whose it was a two-by-two + + + align:start position:0% +something whose it was a two-by-two +matrix of functions of T and whose + + align:start position:0% +matrix of functions of T and whose + + + align:start position:0% +matrix of functions of T and whose +columns were two independent solutions X + + align:start position:0% +columns were two independent solutions X + + + align:start position:0% +columns were two independent solutions X +1 X 2 these + + align:start position:0% +1 X 2 these + + + align:start position:0% +1 X 2 these +were two independent solutions in other + + align:start position:0% +were two independent solutions in other + + + align:start position:0% +were two independent solutions in other +words neither was a constant multiple of + + align:start position:0% +words neither was a constant multiple of + + + align:start position:0% +words neither was a constant multiple of +the other now + + align:start position:0% +the other now + + + align:start position:0% +the other now +I spent a fair amount of time showing + + align:start position:0% +I spent a fair amount of time showing + + + align:start position:0% +I spent a fair amount of time showing +you how to how to be essential the two + + align:start position:0% +you how to how to be essential the two + + + align:start position:0% +you how to how to be essential the two +essential properties that a fundamental + + align:start position:0% +essential properties that a fundamental + + + align:start position:0% +essential properties that a fundamental +matrix had so it's we're going to need + + align:start position:0% +matrix had so it's we're going to need + + + align:start position:0% +matrix had so it's we're going to need +those today so let me remind you the + + align:start position:0% +those today so let me remind you the + + + align:start position:0% +those today so let me remind you the +basic properties the + + align:start position:0% + + + + align:start position:0% + +basic properties of X and the properties + + align:start position:0% +basic properties of X and the properties + + + align:start position:0% +basic properties of X and the properties +by which you could recognize one if you + + align:start position:0% +by which you could recognize one if you + + + align:start position:0% +by which you could recognize one if you +were given one is first of all the easy + + align:start position:0% +were given one is first of all the easy + + + align:start position:0% +were given one is first of all the easy +one that its determinant shall not be 0 + + align:start position:0% +one that its determinant shall not be 0 + + + align:start position:0% +one that its determinant shall not be 0 +is not 0 for any for any value of the + + align:start position:0% +is not 0 for any for any value of the + + + align:start position:0% +is not 0 for any for any value of the +variable that simply + + align:start position:0% + + + + align:start position:0% + +expresses the fact that it's two columns + + align:start position:0% +expresses the fact that it's two columns + + + align:start position:0% +expresses the fact that it's two columns +are independent linearly independent not + + align:start position:0% +are independent linearly independent not + + + align:start position:0% +are independent linearly independent not +a multiple of each other the other one + + align:start position:0% +a multiple of each other the other one + + + align:start position:0% +a multiple of each other the other one +was more bizarre so I tried to call a + + align:start position:0% +was more bizarre so I tried to call a + + + align:start position:0% +was more bizarre so I tried to call a +little more attention to it it was that + + align:start position:0% +little more attention to it it was that + + + align:start position:0% +little more attention to it it was that +the matrix satisfies a differential + + align:start position:0% +the matrix satisfies a differential + + + align:start position:0% +the matrix satisfies a differential +equation of its own which looks almost + + align:start position:0% +equation of its own which looks almost + + + align:start position:0% +equation of its own which looks almost +the same except it's a matrix + + align:start position:0% +the same except it's a matrix + + + align:start position:0% +the same except it's a matrix +differential equation it's + + align:start position:0% +differential equation it's + + + align:start position:0% +differential equation it's +not column vectors which are solutions + + align:start position:0% +not column vectors which are solutions + + + align:start position:0% +not column vectors which are solutions +but matrices as a whole which are + + align:start position:0% +but matrices as a whole which are + + + align:start position:0% +but matrices as a whole which are +solutions in other words X if you take + + align:start position:0% +solutions in other words X if you take + + + align:start position:0% +solutions in other words X if you take +that matrix and differentiate every + + align:start position:0% +that matrix and differentiate every + + + align:start position:0% +that matrix and differentiate every +entry what you get is the same as a + + align:start position:0% +entry what you get is the same as a + + + align:start position:0% +entry what you get is the same as a +multiplied by that matrix you started + + align:start position:0% +multiplied by that matrix you started + + + align:start position:0% +multiplied by that matrix you started +with this + + align:start position:0% +with this + + + align:start position:0% +with this +remember expressed the fact it was just + + align:start position:0% +remember expressed the fact it was just + + + align:start position:0% +remember expressed the fact it was just +really formal when you analyze what it + + align:start position:0% +really formal when you analyze what it + + + align:start position:0% +really formal when you analyze what it +was but it expresses the fact that the + + align:start position:0% +was but it expresses the fact that the + + + align:start position:0% +was but it expresses the fact that the +columns it says that the columns are + + align:start position:0% +columns it says that the columns are + + + align:start position:0% +columns it says that the columns are +solve the system so + + align:start position:0% + + + + align:start position:0% + +the first thing says the columns are + + align:start position:0% +the first thing says the columns are + + + align:start position:0% +the first thing says the columns are +independent and the second say to the + + align:start position:0% +independent and the second say to the + + + align:start position:0% +independent and the second say to the +columns each column separately is a + + align:start position:0% +columns each column separately is a + + + align:start position:0% +columns each column separately is a +solution to the system that's + + align:start position:0% +solution to the system that's + + + align:start position:0% +solution to the system that's +as far as more or less so then I went in + + align:start position:0% +as far as more or less so then I went in + + + align:start position:0% +as far as more or less so then I went in +another direction we talked about + + align:start position:0% +another direction we talked about + + + align:start position:0% +another direction we talked about +variation of parameters oh I'm not going + + align:start position:0% +variation of parameters oh I'm not going + + + align:start position:0% +variation of parameters oh I'm not going +to come back to variation of parameters + + align:start position:0% +to come back to variation of parameters + + + align:start position:0% +to come back to variation of parameters +today we're going in a different tack + + align:start position:0% +today we're going in a different tack + + + align:start position:0% +today we're going in a different tack +the tack we're going on is I want to + + align:start position:0% +the tack we're going on is I want to + + + align:start position:0% +the tack we're going on is I want to +first talk a little more about the + + align:start position:0% +first talk a little more about the + + + align:start position:0% +first talk a little more about the +fundamental matrix and then as I said + + align:start position:0% +fundamental matrix and then as I said + + + align:start position:0% +fundamental matrix and then as I said +we'll talk about an entirely different + + align:start position:0% +we'll talk about an entirely different + + + align:start position:0% +we'll talk about an entirely different +method of solving the system one which + + align:start position:0% +method of solving the system one which + + + align:start position:0% +method of solving the system one which +makes no mention of eigenvalues or + + align:start position:0% +makes no mention of eigenvalues or + + + align:start position:0% +makes no mention of eigenvalues or +eigenvectors if you can believe that but + + align:start position:0% +eigenvectors if you can believe that but + + + align:start position:0% +eigenvectors if you can believe that but +first + + align:start position:0% +first + + + align:start position:0% +first +the + + align:start position:0% +the + + + align:start position:0% +the +one confusing thing about the + + align:start position:0% +one confusing thing about the + + + align:start position:0% +one confusing thing about the +fundamental matrix is that it is not + + align:start position:0% +fundamental matrix is that it is not + + + align:start position:0% +fundamental matrix is that it is not +unique I cannot + + align:start position:0% +unique I cannot + + + align:start position:0% +unique I cannot +I've been carefully trying to avoid + + align:start position:0% +I've been carefully trying to avoid + + + align:start position:0% +I've been carefully trying to avoid +talking about the rough fundamental + + align:start position:0% +talking about the rough fundamental + + + align:start position:0% +talking about the rough fundamental +matrix because there is no fundamental + + align:start position:0% +matrix because there is no fundamental + + + align:start position:0% +matrix because there is no fundamental +matrix there is only a fundamental + + align:start position:0% +matrix there is only a fundamental + + + align:start position:0% +matrix there is only a fundamental +matrix why + + align:start position:0% +matrix why + + + align:start position:0% +matrix why +is that well because these two columns + + align:start position:0% +is that well because these two columns + + + align:start position:0% +is that well because these two columns +can be any two independent solutions and + + align:start position:0% +can be any two independent solutions and + + + align:start position:0% +can be any two independent solutions and +there are an infinity of ways of picking + + align:start position:0% +there are an infinity of ways of picking + + + align:start position:0% +there are an infinity of ways of picking +independent solutions that means they're + + align:start position:0% +independent solutions that means they're + + + align:start position:0% +independent solutions that means they're +an infinity of ways affinity of possible + + align:start position:0% +an infinity of ways affinity of possible + + + align:start position:0% +an infinity of ways affinity of possible +fundamental matrices well that's + + align:start position:0% +fundamental matrices well that's + + + align:start position:0% +fundamental matrices well that's +disgusting but uh can + + align:start position:0% + + + + align:start position:0% + +we repair it a little bit I mean maybe + + align:start position:0% +we repair it a little bit I mean maybe + + + align:start position:0% +we repair it a little bit I mean maybe +they're all de Rivel from each other in + + align:start position:0% +they're all de Rivel from each other in + + + align:start position:0% +they're all de Rivel from each other in +some simple way and that's of course + + align:start position:0% +some simple way and that's of course + + + align:start position:0% +some simple way and that's of course +what is true now as a prelude to doing + + align:start position:0% +what is true now as a prelude to doing + + + align:start position:0% +what is true now as a prelude to doing +that I'd like to show you what I should + + align:start position:0% +that I'd like to show you what I should + + + align:start position:0% +that I'd like to show you what I should +have showed you on Friday but again I + + align:start position:0% +have showed you on Friday but again I + + + align:start position:0% +have showed you on Friday but again I +ran out of time how do you write the + + align:start position:0% +ran out of time how do you write the + + + align:start position:0% +ran out of time how do you write the +fundamental + + align:start position:0% +fundamental + + + align:start position:0% +fundamental +solution to the + + align:start position:0% + + + + align:start position:0% + +system the per system I'm talking about + + align:start position:0% +system the per system I'm talking about + + + align:start position:0% +system the per system I'm talking about +is that pink system well of course the + + align:start position:0% +is that pink system well of course the + + + align:start position:0% +is that pink system well of course the +standard naive way of doing it is its x + + align:start position:0% +standard naive way of doing it is its x + + + align:start position:0% +standard naive way of doing it is its x +equals the general solution is an + + align:start position:0% +equals the general solution is an + + + align:start position:0% +equals the general solution is an +arbitrary constant times at first + + align:start position:0% +arbitrary constant times at first + + + align:start position:0% +arbitrary constant times at first +solution you found plus c2 times the + + align:start position:0% +solution you found plus c2 times the + + + align:start position:0% +solution you found plus c2 times the +second another arbitrary constant times + + align:start position:0% +second another arbitrary constant times + + + align:start position:0% +second another arbitrary constant times +the second solution you found okay now + + align:start position:0% +the second solution you found okay now + + + align:start position:0% +the second solution you found okay now +how would you abbreviate that using the + + align:start position:0% +how would you abbreviate that using the + + + align:start position:0% +how would you abbreviate that using the +fundamental matrix well I did something + + align:start position:0% +fundamental matrix well I did something + + + align:start position:0% +fundamental matrix well I did something +very similar to this on Friday except + + align:start position:0% +very similar to this on Friday except + + + align:start position:0% +very similar to this on Friday except +these were called V's it was part of the + + align:start position:0% +these were called V's it was part of the + + + align:start position:0% +these were called V's it was part of the +variation of parameters method but I + + align:start position:0% +variation of parameters method but I + + + align:start position:0% +variation of parameters method but I +promised not to use those words today so + + align:start position:0% +promised not to use those words today so + + + align:start position:0% +promised not to use those words today so +I just said nothing okay what is what is + + align:start position:0% +I just said nothing okay what is what is + + + align:start position:0% +I just said nothing okay what is what is +the answer so it is x equals how + + align:start position:0% +the answer so it is x equals how + + + align:start position:0% +the answer so it is x equals how +do I write this using the fundamental + + align:start position:0% +do I write this using the fundamental + + + align:start position:0% +do I write this using the fundamental +matrix x1 x2 simple its capital x times + + align:start position:0% +matrix x1 x2 simple its capital x times + + + align:start position:0% +matrix x1 x2 simple its capital x times +mu + + align:start position:0% +mu + + + align:start position:0% +mu +times the + + align:start position:0% +times the + + + align:start position:0% +times the +vector whose columns the vector whose + + align:start position:0% +vector whose columns the vector whose + + + align:start position:0% +vector whose columns the vector whose +entry column vector whose entries are c1 + + align:start position:0% +entry column vector whose entries are c1 + + + align:start position:0% +entry column vector whose entries are c1 +and c2 in + + align:start position:0% +and c2 in + + + align:start position:0% +and c2 in +other words it is x1 + + align:start position:0% +other words it is x1 + + + align:start position:0% +other words it is x1 +x2 times + + align:start position:0% + + + + align:start position:0% + +the column vector c1 c2 isn't it yeah + + align:start position:0% +the column vector c1 c2 isn't it yeah + + + align:start position:0% +the column vector c1 c2 isn't it yeah +because if you multiply this think of + + align:start position:0% +because if you multiply this think of + + + align:start position:0% +because if you multiply this think of +think top row top row top row c1 top + + align:start position:0% +think top row top row top row c1 top + + + align:start position:0% +think top row top row top row c1 top +rope plus top row times c2 that exactly + + align:start position:0% +rope plus top row times c2 that exactly + + + align:start position:0% +rope plus top row times c2 that exactly +gives you the top row here and the same + + align:start position:0% +gives you the top row here and the same + + + align:start position:0% +gives you the top row here and the same +way the bottom row here times this + + align:start position:0% +way the bottom row here times this + + + align:start position:0% +way the bottom row here times this +vector gives you the bottom row of that + + align:start position:0% +vector gives you the bottom row of that + + + align:start position:0% +vector gives you the bottom row of that +so it's just another way of right that + + align:start position:0% +so it's just another way of right that + + + align:start position:0% +so it's just another way of right that +but it looks very efficient now + + align:start position:0% +but it looks very efficient now + + + align:start position:0% +but it looks very efficient now +sometimes efficiency isn't the good + + align:start position:0% +sometimes efficiency isn't the good + + + align:start position:0% +sometimes efficiency isn't the good +thing you know you have to watch out for + + align:start position:0% +thing you know you have to watch out for + + + align:start position:0% +thing you know you have to watch out for +it but here it's good so + + align:start position:0% +it but here it's good so + + + align:start position:0% +it but here it's good so +this is the general solution written out + + align:start position:0% +this is the general solution written out + + + align:start position:0% +this is the general solution written out +using a fundamental matrix and you can't + + align:start position:0% +using a fundamental matrix and you can't + + + align:start position:0% +using a fundamental matrix and you can't +use less symbols than that there's just + + align:start position:0% +use less symbols than that there's just + + + align:start position:0% +use less symbols than that there's just +no way well + + align:start position:0% + + + + align:start position:0% + +but that gives us our answer to what do + + align:start position:0% +but that gives us our answer to what do + + + align:start position:0% +but that gives us our answer to what do +all fundamental matrices look like well + + align:start position:0% + + + + align:start position:0% + +they're two columns or solutions so the + + align:start position:0% +they're two columns or solutions so the + + + align:start position:0% +they're two columns or solutions so the +answer is they look like X now the first + + align:start position:0% +answer is they look like X now the first + + + align:start position:0% +answer is they look like X now the first +column is an arbitrary solution how + + align:start position:0% +column is an arbitrary solution how + + + align:start position:0% +column is an arbitrary solution how +do I write an arbitrary solution there's + + align:start position:0% +do I write an arbitrary solution there's + + + align:start position:0% +do I write an arbitrary solution there's +the general solution I make it a + + align:start position:0% +the general solution I make it a + + + align:start position:0% +the general solution I make it a +particular one by giving a particular + + align:start position:0% +particular one by giving a particular + + + align:start position:0% +particular one by giving a particular +value to that column vector of arbitrary + + align:start position:0% +value to that column vector of arbitrary + + + align:start position:0% +value to that column vector of arbitrary +constants like 2 3 or minus 1 pi or + + align:start position:0% +constants like 2 3 or minus 1 pi or + + + align:start position:0% +constants like 2 3 or minus 1 pi or +something like that so if the first guy + + align:start position:0% +something like that so if the first guy + + + align:start position:0% +something like that so if the first guy +is a solution and I've just shown you I + + align:start position:0% +is a solution and I've just shown you I + + + align:start position:0% +is a solution and I've just shown you I +can write such a solution like X C 1 + + align:start position:0% +can write such a solution like X C 1 + + + align:start position:0% +can write such a solution like X C 1 +with a column vector a particular column + + align:start position:0% +with a column vector a particular column + + + align:start position:0% +with a column vector a particular column +vector of numbers this is a solution + + align:start position:0% +vector of numbers this is a solution + + + align:start position:0% +vector of numbers this is a solution +because + + align:start position:0% +because + + + align:start position:0% +because +that the green thing says it is and side + + align:start position:0% +that the green thing says it is and side + + + align:start position:0% +that the green thing says it is and side +by side we'll write another one and + + align:start position:0% +by side we'll write another one and + + + align:start position:0% +by side we'll write another one and +now all I have to do is of + + align:start position:0% +now all I have to do is of + + + align:start position:0% +now all I have to do is of +course there's supposed to be a + + align:start position:0% +course there's supposed to be a + + + align:start position:0% +course there's supposed to be a +dependent we'll + + align:start position:0% +dependent we'll + + + align:start position:0% +dependent we'll +worry about that in just a moment all I + + align:start position:0% +worry about that in just a moment all I + + + align:start position:0% +worry about that in just a moment all I +have to do is make this look better now + + align:start position:0% +have to do is make this look better now + + + align:start position:0% +have to do is make this look better now +I showed you last time by the laws of + + align:start position:0% +I showed you last time by the laws of + + + align:start position:0% +I showed you last time by the laws of +matrix multiplication if the first + + align:start position:0% +matrix multiplication if the first + + + align:start position:0% +matrix multiplication if the first +column is X c1 and the second column is + + align:start position:0% +column is X c1 and the second column is + + + align:start position:0% +column is X c1 and the second column is +x c2 using matrix multiplication that's + + align:start position:0% +x c2 using matrix multiplication that's + + + align:start position:0% +x c2 using matrix multiplication that's +the same as writing it this way this + + align:start position:0% +the same as writing it this way this + + + align:start position:0% +the same as writing it this way this +square matrix times the matrix whose + + align:start position:0% +square matrix times the matrix whose + + + align:start position:0% +square matrix times the matrix whose +entries are the first column vector and + + align:start position:0% +entries are the first column vector and + + + align:start position:0% +entries are the first column vector and +the second column vector now + + align:start position:0% +the second column vector now + + + align:start position:0% +the second column vector now +I'm going to call this C it's + + align:start position:0% +I'm going to call this C it's + + + align:start position:0% +I'm going to call this C it's +a square matrix of constants it's a + + align:start position:0% +a square matrix of constants it's a + + + align:start position:0% +a square matrix of constants it's a +two-by-two matrix of constants + + align:start position:0% +two-by-two matrix of constants + + + align:start position:0% +two-by-two matrix of constants +and so + + align:start position:0% +and so + + + align:start position:0% +and so +the final way of writing it is x times + + align:start position:0% +the final way of writing it is x times + + + align:start position:0% +the final way of writing it is x times +it's what just what corresponds to that + + align:start position:0% +it's what just what corresponds to that + + + align:start position:0% +it's what just what corresponds to that +but X times C and so this is the most + + align:start position:0% +but X times C and so this is the most + + + align:start position:0% +but X times C and so this is the most +general fund so X is a given fundamental + + align:start position:0% +general fund so X is a given fundamental + + + align:start position:0% +general fund so X is a given fundamental +matrix this one that one so the most + + align:start position:0% +matrix this one that one so the most + + + align:start position:0% +matrix this one that one so the most +general fundamental matrix is + + align:start position:0% + + + + align:start position:0% + +then the one you started with and + + align:start position:0% +then the one you started with and + + + align:start position:0% +then the one you started with and +multiply it by an arbitrary square + + align:start position:0% +multiply it by an arbitrary square + + + align:start position:0% +multiply it by an arbitrary square +matrix of constants except you want to + + align:start position:0% +matrix of constants except you want to + + + align:start position:0% +matrix of constants except you want to +keep be sure that the determinant is not + + align:start position:0% +keep be sure that the determinant is not + + + align:start position:0% +keep be sure that the determinant is not +zero well the determinant of this guy + + align:start position:0% +zero well the determinant of this guy + + + align:start position:0% +zero well the determinant of this guy +won't be zero so all you have to do is + + align:start position:0% +won't be zero so all you have to do is + + + align:start position:0% +won't be zero so all you have to do is +make sure that the determinant of C + + align:start position:0% +make sure that the determinant of C + + + align:start position:0% +make sure that the determinant of C +isn't zero either so + + align:start position:0% + + + + align:start position:0% + +in other words the fundamental matrix + + align:start position:0% +in other words the fundamental matrix + + + align:start position:0% +in other words the fundamental matrix +isn't unique but once you've found one + + align:start position:0% +isn't unique but once you've found one + + + align:start position:0% +isn't unique but once you've found one +all the other ones are found by + + align:start position:0% +all the other ones are found by + + + align:start position:0% +all the other ones are found by +multiplying it on the right by an + + align:start position:0% +multiplying it on the right by an + + + align:start position:0% +multiplying it on the right by an +arbitrary square matrix of constants + + align:start position:0% +arbitrary square matrix of constants + + + align:start position:0% +arbitrary square matrix of constants +which is non singular as determinate not + + align:start position:0% +which is non singular as determinate not + + + align:start position:0% +which is non singular as determinate not +zero in other words well + + align:start position:0% +zero in other words well + + + align:start position:0% +zero in other words well +that was all Friday that's Friday + + align:start position:0% +that was all Friday that's Friday + + + align:start position:0% +that was all Friday that's Friday +leaking over into Monday and now we + + align:start position:0% +leaking over into Monday and now we + + + align:start position:0% +leaking over into Monday and now we +begin the true Monday + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +here's the problem once + + align:start position:0% +here's the problem once + + + align:start position:0% +here's the problem once +again we've got to start with we've got + + align:start position:0% +again we've got to start with we've got + + + align:start position:0% +again we've got to start with we've got +our two two-by-two system or n-by-n if + + align:start position:0% +our two two-by-two system or n-by-n if + + + align:start position:0% +our two two-by-two system or n-by-n if +you want to be super general there's + + align:start position:0% +you want to be super general there's + + + align:start position:0% +you want to be super general there's +a system uh what + + align:start position:0% +a system uh what + + + align:start position:0% +a system uh what +have we got so far by way of solving it + + align:start position:0% +have we got so far by way of solving it + + + align:start position:0% +have we got so far by way of solving it +well if + + align:start position:0% + + + + align:start position:0% + +somebody you know your kid brother or + + align:start position:0% +somebody you know your kid brother or + + + align:start position:0% +somebody you know your kid brother or +sister when you go home says okay yeah + + align:start position:0% +sister when you go home says okay yeah + + + align:start position:0% +sister when you go home says okay yeah +precocious kid okay so tell us how I + + align:start position:0% +precocious kid okay so tell us how I + + + align:start position:0% +precocious kid okay so tell us how I +tell you how to solve this thing I think + + align:start position:0% +tell you how to solve this thing I think + + + align:start position:0% +tell you how to solve this thing I think +all the only thing you'll be able to say + + align:start position:0% +all the only thing you'll be able to say + + + align:start position:0% +all the only thing you'll be able to say +well you do this you take the matrix and + + align:start position:0% +well you do this you take the matrix and + + + align:start position:0% +well you do this you take the matrix and +then you calculate something called + + align:start position:0% +then you calculate something called + + + align:start position:0% +then you calculate something called +saiga values and eigenvectors you know + + align:start position:0% +saiga values and eigenvectors you know + + + align:start position:0% +saiga values and eigenvectors you know +what those are yeah I didn't think you + + align:start position:0% +what those are yeah I didn't think you + + + align:start position:0% +what those are yeah I didn't think you +did bla ll show how smart I am as you + + align:start position:0% +did bla ll show how smart I am as you + + + align:start position:0% +did bla ll show how smart I am as you +that explain what the eigenvalues and + + align:start position:0% +that explain what the eigenvalues and + + + align:start position:0% +that explain what the eigenvalues and +eigenvectors are and then you show how + + align:start position:0% +eigenvectors are and then you show how + + + align:start position:0% +eigenvectors are and then you show how +to of those make up special solutions + + align:start position:0% +to of those make up special solutions + + + align:start position:0% +to of those make up special solutions +and then you take a combination of that + + align:start position:0% +and then you take a combination of that + + + align:start position:0% +and then you take a combination of that +and in other words it's an algorithm + + align:start position:0% +and in other words it's an algorithm + + + align:start position:0% +and in other words it's an algorithm +it's something you do a process a method + + align:start position:0% +it's something you do a process a method + + + align:start position:0% +it's something you do a process a method +and when it's all done you have the + + align:start position:0% +and when it's all done you have the + + + align:start position:0% +and when it's all done you have the +general solution now that's fine for + + align:start position:0% +general solution now that's fine for + + + align:start position:0% +general solution now that's fine for +calculating particular problems you know + + align:start position:0% +calculating particular problems you know + + + align:start position:0% +calculating particular problems you know +with definite numbers a definite model + + align:start position:0% +with definite numbers a definite model + + + align:start position:0% +with definite numbers a definite model +with definite numbers in it where you + + align:start position:0% +with definite numbers in it where you + + + align:start position:0% +with definite numbers in it where you +want to definite answer and of course a + + align:start position:0% +want to definite answer and of course a + + + align:start position:0% +want to definite answer and of course a +lot of your work in engineering and + + align:start position:0% +lot of your work in engineering and + + + align:start position:0% +lot of your work in engineering and +science classes is that kind of work but + + align:start position:0% +science classes is that kind of work but + + + align:start position:0% +science classes is that kind of work but +the further you get on well when you + + align:start position:0% +the further you get on well when you + + + align:start position:0% +the further you get on well when you +start reading books for example or god + + align:start position:0% +start reading books for example or god + + + align:start position:0% +start reading books for example or god +forbid start reading papers in which you + + align:start position:0% +forbid start reading papers in which you + + + align:start position:0% +forbid start reading papers in which you +know people are telling you you know + + align:start position:0% +know people are telling you you know + + + align:start position:0% +know people are telling you you know +they're doing engineering or they're + + align:start position:0% +they're doing engineering or they're + + + align:start position:0% +they're doing engineering or they're +doing science they + + align:start position:0% +doing science they + + + align:start position:0% +doing science they +don't want to method what they want is a + + align:start position:0% +don't want to method what they want is a + + + align:start position:0% +don't want to method what they want is a +formula in other words what I the + + align:start position:0% +formula in other words what I the + + + align:start position:0% +formula in other words what I the +problem is to fill in the blank in + + align:start position:0% +problem is to fill in the blank in + + + align:start position:0% +problem is to fill in the blank in +the following you're writing a paper and + + align:start position:0% +the following you're writing a paper and + + + align:start position:0% +the following you're writing a paper and +you just set up some elaborate model and + + align:start position:0% +you just set up some elaborate model and + + + align:start position:0% +you just set up some elaborate model and +a is a matrix derived from that model in + + align:start position:0% +a is a matrix derived from that model in + + + align:start position:0% +a is a matrix derived from that model in +some way you know represents bacteria + + align:start position:0% +some way you know represents bacteria + + + align:start position:0% +some way you know represents bacteria +doing something or bank accounts doing + + align:start position:0% +doing something or bank accounts doing + + + align:start position:0% +doing something or bank accounts doing +something I don't know and you said as + + align:start position:0% +something I don't know and you said as + + + align:start position:0% +something I don't know and you said as +is well known the solution is of course + + align:start position:0% +is well known the solution is of course + + + align:start position:0% +is well known the solution is of course +you've only got letters here no numbers + + align:start position:0% +you've only got letters here no numbers + + + align:start position:0% +you've only got letters here no numbers +this is a general paper the solution is + + align:start position:0% +this is a general paper the solution is + + + align:start position:0% +this is a general paper the solution is +given by the + + align:start position:0% + + + + align:start position:0% + +formula vo + + align:start position:0% + + + + align:start position:0% + +trouble is we don't have a formula well + + align:start position:0% +trouble is we don't have a formula well + + + align:start position:0% +trouble is we don't have a formula well +we have as a method now people don't + + align:start position:0% +we have as a method now people don't + + + align:start position:0% +we have as a method now people don't +like that so + + align:start position:0% +like that so + + + align:start position:0% +like that so +what I'm going to produce for you this + + align:start position:0% +what I'm going to produce for you this + + + align:start position:0% +what I'm going to produce for you this +period is a formula that that + + align:start position:0% +period is a formula that that + + + align:start position:0% +period is a formula that that +formula does not require the calculation + + align:start position:0% +formula does not require the calculation + + + align:start position:0% +formula does not require the calculation +of any eigenvalues eigenvectors doesn't + + align:start position:0% +of any eigenvalues eigenvectors doesn't + + + align:start position:0% +of any eigenvalues eigenvectors doesn't +require any of that it's therefore a + + align:start position:0% +require any of that it's therefore a + + + align:start position:0% +require any of that it's therefore a +very popular way to fill in to finish + + align:start position:0% +very popular way to fill in to finish + + + align:start position:0% +very popular way to fill in to finish +that sentence now + + align:start position:0% +that sentence now + + + align:start position:0% +that sentence now +the question is where is that formula + + align:start position:0% +the question is where is that formula + + + align:start position:0% +the question is where is that formula +going to come from well we are for the + + align:start position:0% +going to come from well we are for the + + + align:start position:0% +going to come from well we are for the +moment clueless oh if + + align:start position:0% +moment clueless oh if + + + align:start position:0% +moment clueless oh if +you're clueless the place to look always + + align:start position:0% +you're clueless the place to look always + + + align:start position:0% +you're clueless the place to look always +is do I know anything about this sort of + + align:start position:0% +is do I know anything about this sort of + + + align:start position:0% +is do I know anything about this sort of +thing I mean is there some special case + + align:start position:0% +thing I mean is there some special case + + + align:start position:0% +thing I mean is there some special case +I could solve it of this problem I could + + align:start position:0% +I could solve it of this problem I could + + + align:start position:0% +I could solve it of this problem I could +solve or that I have solved in the past + + align:start position:0% +solve or that I have solved in the past + + + align:start position:0% +solve or that I have solved in the past +and the answer that is yes ah you + + align:start position:0% +and the answer that is yes ah you + + + align:start position:0% +and the answer that is yes ah you +haven't solved it for 2x2 matrix but you + + align:start position:0% +haven't solved it for 2x2 matrix but you + + + align:start position:0% +haven't solved it for 2x2 matrix but you +have solved it for a one by one matrix a + + align:start position:0% +have solved it for a one by one matrix a + + + align:start position:0% +have solved it for a one by one matrix a +one + + align:start position:0% +one + + + align:start position:0% +one +by one matrix also goes by the name of a + + align:start position:0% +by one matrix also goes by the name of a + + + align:start position:0% +by one matrix also goes by the name of a +constant it's + + align:start position:0% +constant it's + + + align:start position:0% +constant it's +just a thing you know it's a number you + + align:start position:0% +just a thing you know it's a number you + + + align:start position:0% +just a thing you know it's a number you +just putting brackets around it doesn't + + align:start position:0% +just putting brackets around it doesn't + + + align:start position:0% +just putting brackets around it doesn't +conceal the fact that it's just a number + + align:start position:0% +conceal the fact that it's just a number + + + align:start position:0% +conceal the fact that it's just a number +so let's look at what's the solution for + + align:start position:0% +so let's look at what's the solution for + + + align:start position:0% +so let's look at what's the solution for +a one by one matrix one by one case if + + align:start position:0% +a one by one matrix one by one case if + + + align:start position:0% +a one by one matrix one by one case if +we're looking for a general solution for + + align:start position:0% +we're looking for a general solution for + + + align:start position:0% +we're looking for a general solution for +the N by n case it must work for the one + + align:start position:0% +the N by n case it must work for the one + + + align:start position:0% +the N by n case it must work for the one +by one case also that's a good + + align:start position:0% +by one case also that's a good + + + align:start position:0% +by one case also that's a good +motivation a good reason for a starting + + align:start position:0% +motivation a good reason for a starting + + + align:start position:0% +motivation a good reason for a starting +that looks like X doesn't it X inside + + align:start position:0% +that looks like X doesn't it X inside + + + align:start position:0% +that looks like X doesn't it X inside +one + + align:start position:0% +one + + + align:start position:0% +one +one + + align:start position:0% + + + + align:start position:0% + +boy one taste + + align:start position:0% + + + + align:start position:0% + +well in that case I'm trying to solve + + align:start position:0% +well in that case I'm trying to solve + + + align:start position:0% +well in that case I'm trying to solve +the system the system consists of a + + align:start position:0% +the system the system consists of a + + + align:start position:0% +the system the system consists of a +single equation that's + + align:start position:0% +single equation that's + + + align:start position:0% +single equation that's +the way the system looks how + + align:start position:0% +the way the system looks how + + + align:start position:0% +the way the system looks how +do you solve that well you were born + + align:start position:0% +do you solve that well you were born + + + align:start position:0% +do you solve that well you were born +knowing how to solve that or you anyway + + align:start position:0% +knowing how to solve that or you anyway + + + align:start position:0% +knowing how to solve that or you anyway +certainly didn't learn it in this course + + align:start position:0% +certainly didn't learn it in this course + + + align:start position:0% +certainly didn't learn it in this course +solution is well + + align:start position:0% +solution is well + + + align:start position:0% +solution is well +you separate variables blah blah blah + + align:start position:0% +you separate variables blah blah blah + + + align:start position:0% +you separate variables blah blah blah +blah blah blah and the solution is x + + align:start position:0% +blah blah blah and the solution is x + + + align:start position:0% +blah blah blah and the solution is x +equals the + + align:start position:0% +equals the + + + align:start position:0% +equals the +basic solution is e to the eighty and + + align:start position:0% +basic solution is e to the eighty and + + + align:start position:0% +basic solution is e to the eighty and +you multiply that by an arbitrary + + align:start position:0% +you multiply that by an arbitrary + + + align:start position:0% +you multiply that by an arbitrary +constant now + + align:start position:0% + + + + align:start position:0% + +if that's a formula it's a formula for + + align:start position:0% +if that's a formula it's a formula for + + + align:start position:0% +if that's a formula it's a formula for +the solution and it uses the parameter + + align:start position:0% +the solution and it uses the parameter + + + align:start position:0% +the solution and it uses the parameter +in the equation I didn't have to know a + + align:start position:0% +in the equation I didn't have to know a + + + align:start position:0% +in the equation I didn't have to know a +special number I didn't have to put a + + align:start position:0% +special number I didn't have to put a + + + align:start position:0% +special number I didn't have to put a +particular number here to use that well + + align:start position:0% +particular number here to use that well + + + align:start position:0% +particular number here to use that well +the + + align:start position:0% +the + + + align:start position:0% +the +answer is that the same idea whatever + + align:start position:0% +answer is that the same idea whatever + + + align:start position:0% +answer is that the same idea whatever +the answer I give here it's got to work + + align:start position:0% +the answer I give here it's got to work + + + align:start position:0% +the answer I give here it's got to work +in this case too so I'll just let's but + + align:start position:0% +in this case too so I'll just let's but + + + align:start position:0% +in this case too so I'll just let's but +let's take a quick look as to why this + + align:start position:0% +let's take a quick look as to why this + + + align:start position:0% +let's take a quick look as to why this +works of course you know you separate + + align:start position:0% +works of course you know you separate + + + align:start position:0% +works of course you know you separate +variables and use calculus I'm going to + + align:start position:0% +variables and use calculus I'm going to + + + align:start position:0% +variables and use calculus I'm going to +give you a slightly different argument + + align:start position:0% +give you a slightly different argument + + + align:start position:0% +give you a slightly different argument +Oh which has the advantage of + + align:start position:0% +Oh which has the advantage of + + + align:start position:0% +Oh which has the advantage of +generalizing to the N by n case and the + + align:start position:0% +generalizing to the N by n case and the + + + align:start position:0% +generalizing to the N by n case and the +argument goes as follows for that it + + align:start position:0% +argument goes as follows for that it + + + align:start position:0% +argument goes as follows for that it +uses the definition of the exponential + + align:start position:0% +uses the definition of the exponential + + + align:start position:0% +uses the definition of the exponential +function not as the inverse to the + + align:start position:0% +function not as the inverse to the + + + align:start position:0% +function not as the inverse to the +logarithm which is where the fancy + + align:start position:0% +logarithm which is where the fancy + + + align:start position:0% +logarithm which is where the fancy +calculus books get it from nor as the + + align:start position:0% +calculus books get it from nor as the + + + align:start position:0% +calculus books get it from nor as the +hice the naive high school method you + + align:start position:0% +hice the naive high school method you + + + align:start position:0% +hice the naive high school method you +know it's a squared means you multiply e + + align:start position:0% +know it's a squared means you multiply e + + + align:start position:0% +know it's a squared means you multiply e +by itself that e cubed need to do it + + align:start position:0% +by itself that e cubed need to do it + + + align:start position:0% +by itself that e cubed need to do it +three times and so on and either the 1/2 + + align:start position:0% +three times and so on and either the 1/2 + + + align:start position:0% +three times and so on and either the 1/2 +means you do it 1/2 a time or something + + align:start position:0% +means you do it 1/2 a time or something + + + align:start position:0% +means you do it 1/2 a time or something +so + + align:start position:0% +so + + + align:start position:0% +so +the naive definition of the exponential + + align:start position:0% +the naive definition of the exponential + + + align:start position:0% +the naive definition of the exponential +function instead I'll use the definition + + align:start position:0% +function instead I'll use the definition + + + align:start position:0% +function instead I'll use the definition +of the exponential function that comes + + align:start position:0% +of the exponential function that comes + + + align:start position:0% +of the exponential function that comes +from an infinite series so leaving out + + align:start position:0% +from an infinite series so leaving out + + + align:start position:0% +from an infinite series so leaving out +the arbitrary constant which we don't + + align:start position:0% +the arbitrary constant which we don't + + + align:start position:0% +the arbitrary constant which we don't +have to bother with e to the 80 is the + + align:start position:0% +have to bother with e to the 80 is the + + + align:start position:0% +have to bother with e to the 80 is the +series 1 + + align:start position:0% + + + + align:start position:0% + +plus 80 plus a squared T squared over 2 + + align:start position:0% +plus 80 plus a squared T squared over 2 + + + align:start position:0% +plus 80 plus a squared T squared over 2 +factorial I'll put out one more turbine + + align:start position:0% +factorial I'll put out one more turbine + + + align:start position:0% +factorial I'll put out one more turbine +call it quits there if + + align:start position:0% + + + + align:start position:0% + +I take this and then the argument goes + + align:start position:0% +I take this and then the argument goes + + + align:start position:0% +I take this and then the argument goes +let's just differentiate it in + + align:start position:0% +let's just differentiate it in + + + align:start position:0% +let's just differentiate it in +other words what's the derivative of e + + align:start position:0% +other words what's the derivative of e + + + align:start position:0% +other words what's the derivative of e +to the a T with + + align:start position:0% + + + + align:start position:0% + +respect to T well just differentiating + + align:start position:0% +respect to T well just differentiating + + + align:start position:0% +respect to T well just differentiating +term by term it's zero plus the first + + align:start position:0% +term by term it's zero plus the first + + + align:start position:0% +term by term it's zero plus the first +term is a the next term is a squared + + align:start position:0% +term is a the next term is a squared + + + align:start position:0% +term is a the next term is a squared +times T this differentiates to T squared + + align:start position:0% +times T this differentiates to T squared + + + align:start position:0% +times T this differentiates to T squared +over two factorial and + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +answer is that this is equal to a times + + align:start position:0% + + + + align:start position:0% + +if you factor out the a what's left is 1 + + align:start position:0% +if you factor out the a what's left is 1 + + + align:start position:0% +if you factor out the a what's left is 1 +plus 80 plus a squared T squared over 2 + + align:start position:0% +plus 80 plus a squared T squared over 2 + + + align:start position:0% +plus 80 plus a squared T squared over 2 +factorial in other words it's simply a e + + align:start position:0% +factorial in other words it's simply a e + + + align:start position:0% +factorial in other words it's simply a e +to the a T in other words by + + align:start position:0% +to the a T in other words by + + + align:start position:0% +to the a T in other words by +differentiating the series using the + + align:start position:0% +differentiating the series using the + + + align:start position:0% +differentiating the series using the +series definition of the exponential and + + align:start position:0% +series definition of the exponential and + + + align:start position:0% +series definition of the exponential and +by differentiating a term by term I can + + align:start position:0% +by differentiating a term by term I can + + + align:start position:0% +by differentiating a term by term I can +immediately see that it satisfies this + + align:start position:0% +immediately see that it satisfies this + + + align:start position:0% +immediately see that it satisfies this +differential equation what + + align:start position:0% + + + + align:start position:0% + +about the arbitrary constant well you if + + align:start position:0% +about the arbitrary constant well you if + + + align:start position:0% +about the arbitrary constant well you if +you like you can include it here but + + align:start position:0% +you like you can include it here but + + + align:start position:0% +you like you can include it here but +it's easier to observe that by linearity + + align:start position:0% +it's easier to observe that by linearity + + + align:start position:0% +it's easier to observe that by linearity +if e to the a T solves the equation so + + align:start position:0% +if e to the a T solves the equation so + + + align:start position:0% +if e to the a T solves the equation so +does a constant times it because it's + + align:start position:0% +does a constant times it because it's + + + align:start position:0% +does a constant times it because it's +Lidia the equation is linear now that's + + align:start position:0% +Lidia the equation is linear now that's + + + align:start position:0% +Lidia the equation is linear now that's +the idea that I'm going to use to solve + + align:start position:0% +the idea that I'm going to use to solve + + + align:start position:0% +the idea that I'm going to use to solve +the system in general what are we going + + align:start position:0% +the system in general what are we going + + + align:start position:0% +the system in general what are we going +to say well what could we say + + align:start position:0% + + + + align:start position:0% + +solution + + align:start position:0% + + + + align:start position:0% + +to the + + align:start position:0% +to the + + + align:start position:0% +to the +solution to well it's better let's let's + + align:start position:0% +solution to well it's better let's let's + + + align:start position:0% +solution to well it's better let's let's +get two solutions at once by writing an + + align:start position:0% +get two solutions at once by writing an + + + align:start position:0% +get two solutions at once by writing an +X writing a fundamental matrix so a + + align:start position:0% +X writing a fundamental matrix so a + + + align:start position:0% +X writing a fundamental matrix so a +fundamental matrix a fundamental matrix + + align:start position:0% +fundamental matrix a fundamental matrix + + + align:start position:0% +fundamental matrix a fundamental matrix +I don't claim it's V 1 or a fundamental + + align:start position:0% +I don't claim it's V 1 or a fundamental + + + align:start position:0% +I don't claim it's V 1 or a fundamental +matrix for the system X prime equals ax + + align:start position:0% +matrix for the system X prime equals ax + + + align:start position:0% +matrix for the system X prime equals ax +so + + align:start position:0% +so + + + align:start position:0% +so +that's what we're trying to solve and + + align:start position:0% +that's what we're trying to solve and + + + align:start position:0% +that's what we're trying to solve and +we're going to get two solutions by + + align:start position:0% +we're going to get two solutions by + + + align:start position:0% +we're going to get two solutions by +getting a fundamental matrix for it + + align:start position:0% +getting a fundamental matrix for it + + + align:start position:0% +getting a fundamental matrix for it +there the answer is is + + align:start position:0% + + + + align:start position:0% + +e + + align:start position:0% +e + + + align:start position:0% +e +to + + align:start position:0% +to + + + align:start position:0% +to +the a T is + + align:start position:0% +the a T is + + + align:start position:0% +the a T is +that what it should be that + + align:start position:0% +that what it should be that + + + align:start position:0% +that what it should be that +little guy I had a little a now we've + + align:start position:0% +little guy I had a little a now we've + + + align:start position:0% +little guy I had a little a now we've +got a matrix ok just put the matrix up + + align:start position:0% +got a matrix ok just put the matrix up + + + align:start position:0% +got a matrix ok just put the matrix up +there now what on earth this first + + align:start position:0% +there now what on earth this first + + + align:start position:0% +there now what on earth this first +person who still must've thought of this + + align:start position:0% +person who still must've thought of this + + + align:start position:0% +person who still must've thought of this +it happens about a hundred years ago oh + + align:start position:0% +it happens about a hundred years ago oh + + + align:start position:0% +it happens about a hundred years ago oh +you know what meeting should be given to + + align:start position:0% +you know what meeting should be given to + + + align:start position:0% +you know what meeting should be given to +e to a matrix power well clearly the too + + align:start position:0% +e to a matrix power well clearly the too + + + align:start position:0% +e to a matrix power well clearly the too +naive definitions won't work are the + + align:start position:0% +naive definitions won't work are the + + + align:start position:0% +naive definitions won't work are the +only possible being you could try for is + + align:start position:0% +only possible being you could try for is + + + align:start position:0% +only possible being you could try for is +using the infinite series but that does + + align:start position:0% +using the infinite series but that does + + + align:start position:0% +using the infinite series but that does +work so + + align:start position:0% + + + + align:start position:0% + +this is a definition I'm giving you the + + align:start position:0% +this is a definition I'm giving you the + + + align:start position:0% +this is a definition I'm giving you the +exponential matrix it is Oh + + align:start position:0% +exponential matrix it is Oh + + + align:start position:0% +exponential matrix it is Oh +now notice the a is a 2 by 2 matrix + + align:start position:0% +now notice the a is a 2 by 2 matrix + + + align:start position:0% +now notice the a is a 2 by 2 matrix +multiplying it by T what I have up here + + align:start position:0% +multiplying it by T what I have up here + + + align:start position:0% +multiplying it by T what I have up here +is that basically a 2 by 2 matrix + + align:start position:0% +is that basically a 2 by 2 matrix + + + align:start position:0% +is that basically a 2 by 2 matrix +it's entries involve T but it's a 2 by 2 + + align:start position:0% +it's entries involve T but it's a 2 by 2 + + + align:start position:0% +it's entries involve T but it's a 2 by 2 +matrix ok + + align:start position:0% +matrix ok + + + align:start position:0% +matrix ok +it's going to be leave out so we're + + align:start position:0% +it's going to be leave out so we're + + + align:start position:0% +it's going to be leave out so we're +trying to get the analog of that formula + + align:start position:0% +trying to get the analog of that formula + + + align:start position:0% +trying to get the analog of that formula +over there well it's going to be leave + + align:start position:0% +over there well it's going to be leave + + + align:start position:0% +over there well it's going to be leave +the first term out just for the moment + + align:start position:0% +the first term out just for the moment + + + align:start position:0% +the first term out just for the moment +the next term is going to early be a + + align:start position:0% +the next term is going to early be a + + + align:start position:0% +the next term is going to early be a +times T this is a 2 by 2 matrix right + + align:start position:0% +times T this is a 2 by 2 matrix right + + + align:start position:0% +times T this is a 2 by 2 matrix right +what's your the next term B well a + + align:start position:0% +what's your the next term B well a + + + align:start position:0% +what's your the next term B well a +squared times T squared over 2 factorial + + align:start position:0% +squared times T squared over 2 factorial + + + align:start position:0% +squared times T squared over 2 factorial +what kind of a guy is that well if a is + + align:start position:0% +what kind of a guy is that well if a is + + + align:start position:0% +what kind of a guy is that well if a is +a 2 by 2 matrix so is a squared how + + align:start position:0% +a 2 by 2 matrix so is a squared how + + + align:start position:0% +a 2 by 2 matrix so is a squared how +about this this is just a scalar which + + align:start position:0% +about this this is just a scalar which + + + align:start position:0% +about this this is just a scalar which +multiplies every entry of a weird and + + align:start position:0% +multiplies every entry of a weird and + + + align:start position:0% +multiplies every entry of a weird and +therefore this is still a two-by-two + + align:start position:0% +therefore this is still a two-by-two + + + align:start position:0% +therefore this is still a two-by-two +matrix that's a two-by-two matrix this + + align:start position:0% +matrix that's a two-by-two matrix this + + + align:start position:0% +matrix that's a two-by-two matrix this +is a 2 by 2 matrix no matter how many + + align:start position:0% +is a 2 by 2 matrix no matter how many + + + align:start position:0% +is a 2 by 2 matrix no matter how many +times you multiply a by itself it stays + + align:start position:0% +times you multiply a by itself it stays + + + align:start position:0% +times you multiply a by itself it stays +a 2 by 2 matrix it gets more and more + + align:start position:0% +a 2 by 2 matrix it gets more and more + + + align:start position:0% +a 2 by 2 matrix it gets more and more +complicated looking but it's always a 2 + + align:start position:0% +complicated looking but it's always a 2 + + + align:start position:0% +complicated looking but it's always a 2 +by 2 matrix and now I'm multiplying + + align:start position:0% +by 2 matrix and now I'm multiplying + + + align:start position:0% +by 2 matrix and now I'm multiplying +every entry of that by T to the scale or + + align:start position:0% +every entry of that by T to the scale or + + + align:start position:0% +every entry of that by T to the scale or +T cubed over 3 factorial and continuing + + align:start position:0% +T cubed over 3 factorial and continuing + + + align:start position:0% +T cubed over 3 factorial and continuing +on in that way what + + align:start position:0% +on in that way what + + + align:start position:0% +on in that way what +I get therefore is the sum of 2 by 2 + + align:start position:0% +I get therefore is the sum of 2 by 2 + + + align:start position:0% +I get therefore is the sum of 2 by 2 +matrices well you can add 2 by 2 + + align:start position:0% +matrices well you can add 2 by 2 + + + align:start position:0% +matrices well you can add 2 by 2 +matrices to each other we've never made + + align:start position:0% +matrices to each other we've never made + + + align:start position:0% +matrices to each other we've never made +an infinite series of them but in fact + + align:start position:0% +an infinite series of them but in fact + + + align:start position:0% +an infinite series of them but in fact +we haven't done it but others have and + + align:start position:0% +we haven't done it but others have and + + + align:start position:0% +we haven't done it but others have and +this is what they wrote the only + + align:start position:0% +this is what they wrote the only + + + align:start position:0% +this is what they wrote the only +question is what should we put at the + + align:start position:0% +question is what should we put at the + + + align:start position:0% +question is what should we put at the +beginning over there I have one the + + align:start position:0% +beginning over there I have one the + + + align:start position:0% +beginning over there I have one the +number 1 but I of course cannot add the + + align:start position:0% +number 1 but I of course cannot add the + + + align:start position:0% +number 1 but I of course cannot add the +number 1 to 2 by 2 matrices what goes + + align:start position:0% +number 1 to 2 by 2 matrices what goes + + + align:start position:0% +number 1 to 2 by 2 matrices what goes +here must be a 2 by 2 matrix which is + + align:start position:0% +here must be a 2 by 2 matrix which is + + + align:start position:0% +here must be a 2 by 2 matrix which is +the closest thing to one I can think of + + align:start position:0% +the closest thing to one I can think of + + + align:start position:0% +the closest thing to one I can think of +what should it be the I 2 by 2 I the 2 + + align:start position:0% +what should it be the I 2 by 2 I the 2 + + + align:start position:0% +what should it be the I 2 by 2 I the 2 +by 2 identity matrix looks like the + + align:start position:0% +by 2 identity matrix looks like the + + + align:start position:0% +by 2 identity matrix looks like the +natural candidate for what to put there + + align:start position:0% +natural candidate for what to put there + + + align:start position:0% +natural candidate for what to put there +and in fact it's the right thing to put + + align:start position:0% +and in fact it's the right thing to put + + + align:start position:0% +and in fact it's the right thing to put +there okay + + align:start position:0% + + + + align:start position:0% + +now I have a conjecture you + + align:start position:0% +now I have a conjecture you + + + align:start position:0% +now I have a conjecture you +know purely formally changing all the + + align:start position:0% +know purely formally changing all the + + + align:start position:0% +know purely formally changing all the +with a keystroke of the computer all the + + align:start position:0% +with a keystroke of the computer all the + + + align:start position:0% +with a keystroke of the computer all the +little a's have been changed to capital + + align:start position:0% +little a's have been changed to capital + + + align:start position:0% +little a's have been changed to capital +a's and now all i have to do is wonder + + align:start position:0% +a's and now all i have to do is wonder + + + align:start position:0% +a's and now all i have to do is wonder +if is this going to work well what do i + + align:start position:0% +if is this going to work well what do i + + + align:start position:0% +if is this going to work well what do i +what's the basic thing I have to check + + align:start position:0% +what's the basic thing I have to check + + + align:start position:0% +what's the basic thing I have to check +to see that it's a fundamental matrix so + + align:start position:0% +to see that it's a fundamental matrix so + + + align:start position:0% +to see that it's a fundamental matrix so +the question is is this is this I wrote + + align:start position:0% +the question is is this is this I wrote + + + align:start position:0% +the question is is this is this I wrote +it down all right but is this a + + align:start position:0% +it down all right but is this a + + + align:start position:0% +it down all right but is this a +fundamental matrix for the system well I + + align:start position:0% +fundamental matrix for the system well I + + + align:start position:0% +fundamental matrix for the system well I +have a way of recognizing a fundamental + + align:start position:0% +have a way of recognizing a fundamental + + + align:start position:0% +have a way of recognizing a fundamental +matrix when I see one the critical thing + + align:start position:0% +matrix when I see one the critical thing + + + align:start position:0% +matrix when I see one the critical thing +is that it should satisfy this matrix + + align:start position:0% +is that it should satisfy this matrix + + + align:start position:0% +is that it should satisfy this matrix +differential equation so + + align:start position:0% +differential equation so + + + align:start position:0% +differential equation so +that's what I should verify does this + + align:start position:0% +that's what I should verify does this + + + align:start position:0% +that's what I should verify does this +guy that I've written down satisfy that + + align:start position:0% +guy that I've written down satisfy that + + + align:start position:0% +guy that I've written down satisfy that +equation and the answer is it satisfies + + align:start position:0% +equation and the answer is it satisfies + + + align:start position:0% +equation and the answer is it satisfies +so + + align:start position:0% +so + + + align:start position:0% +so +number two is it satisfies X Prime + + align:start position:0% +number two is it satisfies X Prime + + + align:start position:0% +number two is it satisfies X Prime +equals + + align:start position:0% +equals + + + align:start position:0% +equals +a X + + align:start position:0% +a X + + + align:start position:0% +a X +in other words plugging in x equals this + + align:start position:0% +in other words plugging in x equals this + + + align:start position:0% +in other words plugging in x equals this +e to the 8e whose definition I just gave + + align:start position:0% +e to the 8e whose definition I just gave + + + align:start position:0% +e to the 8e whose definition I just gave +you if I substitute that in does it + + align:start position:0% +you if I substitute that in does it + + + align:start position:0% +you if I substitute that in does it +satisfy that matrix differential + + align:start position:0% +satisfy that matrix differential + + + align:start position:0% +satisfy that matrix differential +equation the answer is yes I'm not going + + align:start position:0% +equation the answer is yes I'm not going + + + align:start position:0% +equation the answer is yes I'm not going +to calculate it out because the + + align:start position:0% +to calculate it out because the + + + align:start position:0% +to calculate it out because the +calculation is absolutely identical to + + align:start position:0% +calculation is absolutely identical to + + + align:start position:0% +calculation is absolutely identical to +what I did there the + + align:start position:0% +what I did there the + + + align:start position:0% +what I did there the +only difference is when I differentiated + + align:start position:0% +only difference is when I differentiated + + + align:start position:0% +only difference is when I differentiated +a term by term how do you differentiate + + align:start position:0% +a term by term how do you differentiate + + + align:start position:0% +a term by term how do you differentiate +something like this well you + + align:start position:0% +something like this well you + + + align:start position:0% +something like this well you +differentiate it every term in it but + + align:start position:0% +differentiate it every term in it but + + + align:start position:0% +differentiate it every term in it but +this if you work it out it's simply this + + align:start position:0% +this if you work it out it's simply this + + + align:start position:0% +this if you work it out it's simply this +is a constant matrix every term of which + + align:start position:0% +is a constant matrix every term of which + + + align:start position:0% +is a constant matrix every term of which +is multiplied by T squared over 2 + + align:start position:0% +is multiplied by T squared over 2 + + + align:start position:0% +is multiplied by T squared over 2 +factorial well if you differentiate + + align:start position:0% +factorial well if you differentiate + + + align:start position:0% +factorial well if you differentiate +every term every entry of that constant + + align:start position:0% +every term every entry of that constant + + + align:start position:0% +every term every entry of that constant +of that matrix what you're going to get + + align:start position:0% +of that matrix what you're going to get + + + align:start position:0% +of that matrix what you're going to get +is a squared times just the derivative + + align:start position:0% +is a squared times just the derivative + + + align:start position:0% +is a squared times just the derivative +of that part which is simply T and the + + align:start position:0% +of that part which is simply T and the + + + align:start position:0% +of that part which is simply T and the +same way in other words calculate the + + align:start position:0% +same way in other words calculate the + + + align:start position:0% +same way in other words calculate the +formal calculations looks absolutely + + align:start position:0% +formal calculations looks absolutely + + + align:start position:0% +formal calculations looks absolutely +identical to that so the answer to this + + align:start position:0% +identical to that so the answer to this + + + align:start position:0% +identical to that so the answer to this +is yes by + + align:start position:0% + + + + align:start position:0% + +the same calculation as before as + + align:start position:0% + + + + align:start position:0% + +for the 1 by 1 case and + + align:start position:0% + + + + align:start position:0% + +now the only other thing to check is + + align:start position:0% +now the only other thing to check is + + + align:start position:0% +now the only other thing to check is +that the determinant is not 0 in fact + + align:start position:0% +that the determinant is not 0 in fact + + + align:start position:0% +that the determinant is not 0 in fact +the determinant is not 0 at one point + + align:start position:0% +the determinant is not 0 at one point + + + align:start position:0% +the determinant is not 0 at one point +that's all you have to check what's X of + + align:start position:0% +that's all you have to check what's X of + + + align:start position:0% +that's all you have to check what's X of +0 what's + + align:start position:0% +0 what's + + + align:start position:0% +0 what's +the determinant at the value of the + + align:start position:0% +the determinant at the value of the + + + align:start position:0% +the determinant at the value of the +determinant of X is e to the a T what's + + align:start position:0% +determinant of X is e to the a T what's + + + align:start position:0% +determinant of X is e to the a T what's +the value of it's this thing at 0 here's + + align:start position:0% +the value of it's this thing at 0 here's + + + align:start position:0% +the value of it's this thing at 0 here's +my function if I plug in T equals 0 + + align:start position:0% +my function if I plug in T equals 0 + + + align:start position:0% +my function if I plug in T equals 0 +what's it equal to all + + align:start position:0% +what's it equal to all + + + align:start position:0% +what's it equal to all +right what's + + align:start position:0% +right what's + + + align:start position:0% +right what's +the determinant of I 1 it is certainly + + align:start position:0% +the determinant of I 1 it is certainly + + + align:start position:0% +the determinant of I 1 it is certainly +not 0 + + align:start position:0% + + + + align:start position:0% + +so by writing down this infinite series + + align:start position:0% +so by writing down this infinite series + + + align:start position:0% +so by writing down this infinite series +I've got my two solutions its columns + + align:start position:0% +I've got my two solutions its columns + + + align:start position:0% +I've got my two solutions its columns +give me two solutions to the original + + align:start position:0% +give me two solutions to the original + + + align:start position:0% +give me two solutions to the original +system there + + align:start position:0% +system there + + + align:start position:0% +system there +were no eigenvalues no eigenvectors I + + align:start position:0% +were no eigenvalues no eigenvectors I + + + align:start position:0% +were no eigenvalues no eigenvectors I +have a formula for the answer what's the + + align:start position:0% +have a formula for the answer what's the + + + align:start position:0% +have a formula for the answer what's the +formula it's e to the a T and of course + + align:start position:0% +formula it's e to the a T and of course + + + align:start position:0% +formula it's e to the a T and of course +anybody reading the paper is supposed to + + align:start position:0% +anybody reading the paper is supposed to + + + align:start position:0% +anybody reading the paper is supposed to +go into the a T is it means that this + + align:start position:0% + + + + align:start position:0% + +is just marvelous there must be a fly in + + align:start position:0% +is just marvelous there must be a fly in + + + align:start position:0% +is just marvelous there must be a fly in +the ointment somewhere only + + align:start position:0% +the ointment somewhere only + + + align:start position:0% +the ointment somewhere only +a teeny they'll fly the T they'll fly if + + align:start position:0% +a teeny they'll fly the T they'll fly if + + + align:start position:0% +a teeny they'll fly the T they'll fly if +it's almost impossible to calculate that + + align:start position:0% +it's almost impossible to calculate that + + + align:start position:0% +it's almost impossible to calculate that +series for all reasonable times however + + align:start position:0% +series for all reasonable times however + + + align:start position:0% +series for all reasonable times however +once in a while it is so let me give you + + align:start position:0% +once in a while it is so let me give you + + + align:start position:0% +once in a while it is so let me give you +an example where it is possible to + + align:start position:0% +an example where it is possible to + + + align:start position:0% +an example where it is possible to +calculate the series and we get a nice + + align:start position:0% +calculate the series and we get a nice + + + align:start position:0% +calculate the series and we get a nice +answer so + + align:start position:0% +answer so + + + align:start position:0% +answer so +let's work out an example + + align:start position:0% + + + + align:start position:0% + +by the way I should you + + align:start position:0% + + + + align:start position:0% + +know nowadays we're + + align:start position:0% +know nowadays we're + + + align:start position:0% +know nowadays we're +not back 50 years the + + align:start position:0% +not back 50 years the + + + align:start position:0% +not back 50 years the +exponential matrix has the same status + + align:start position:0% +exponential matrix has the same status + + + align:start position:0% +exponential matrix has the same status +on say a MATLAB or maple or Mathematica + + align:start position:0% +on say a MATLAB or maple or Mathematica + + + align:start position:0% +on say a MATLAB or maple or Mathematica +as the ordinary exponential function + + align:start position:0% +as the ordinary exponential function + + + align:start position:0% +as the ordinary exponential function +does it's just a command you type in you + + align:start position:0% +does it's just a command you type in you + + + align:start position:0% +does it's just a command you type in you +type in your matrix and use now say X X + + align:start position:0% +type in your matrix and use now say X X + + + align:start position:0% +type in your matrix and use now say X X +exp of that matrix and out comes the + + align:start position:0% +exp of that matrix and out comes the + + + align:start position:0% +exp of that matrix and out comes the +answer to as many decimal places as you + + align:start position:0% +answer to as many decimal places as you + + + align:start position:0% +answer to as many decimal places as you +want it'll be a square matrix with + + align:start position:0% +want it'll be a square matrix with + + + align:start position:0% +want it'll be a square matrix with +entries carefully + + align:start position:0% +entries carefully + + + align:start position:0% +entries carefully +written out so in + + align:start position:0% +written out so in + + + align:start position:0% +written out so in +that sense you know the fact that we + + align:start position:0% +that sense you know the fact that we + + + align:start position:0% +that sense you know the fact that we +can't calculate it shouldn't bother us + + align:start position:0% +can't calculate it shouldn't bother us + + + align:start position:0% +can't calculate it shouldn't bother us +you know there are machines to do the + + align:start position:0% +you know there are machines to do the + + + align:start position:0% +you know there are machines to do the +calculations but we're interested in is + + align:start position:0% +calculations but we're interested in is + + + align:start position:0% +calculations but we're interested in is +it as a theoretical tool but let's in + + align:start position:0% +it as a theoretical tool but let's in + + + align:start position:0% +it as a theoretical tool but let's in +order to get any feeling for this at all + + align:start position:0% +order to get any feeling for this at all + + + align:start position:0% +order to get any feeling for this at all +you we certainly have to do a few + + align:start position:0% +you we certainly have to do a few + + + align:start position:0% +you we certainly have to do a few +calculations so let's do it easy one + + align:start position:0% +calculations so let's do it easy one + + + align:start position:0% +calculations so let's do it easy one +let's consider the system X prime equals + + align:start position:0% +let's consider the system X prime equals + + + align:start position:0% +let's consider the system X prime equals +y y prime equals x this + + align:start position:0% +y y prime equals x this + + + align:start position:0% +y y prime equals x this +is very easily done by elimination but + + align:start position:0% +is very easily done by elimination but + + + align:start position:0% +is very easily done by elimination but +that's forbidden so + + align:start position:0% +that's forbidden so + + + align:start position:0% +that's forbidden so +first of all we write it as a matrix so + + align:start position:0% +first of all we write it as a matrix so + + + align:start position:0% +first of all we write it as a matrix so +X prime it's the system X prime equals 0 + + align:start position:0% +X prime it's the system X prime equals 0 + + + align:start position:0% +X prime it's the system X prime equals 0 +1 1 0 X so here's my egg and so + + align:start position:0% +1 1 0 X so here's my egg and so + + + align:start position:0% +1 1 0 X so here's my egg and so +e to the a T is going + + align:start position:0% +e to the a T is going + + + align:start position:0% +e to the a T is going +to be so a is 0 1 1 0 so what we want to + + align:start position:0% +to be so a is 0 1 1 0 so what we want to + + + align:start position:0% +to be so a is 0 1 1 0 so what we want to +calculate is we're going to get both + + align:start position:0% +calculate is we're going to get both + + + align:start position:0% +calculate is we're going to get both +solutions at once by calculating it one + + align:start position:0% +solutions at once by calculating it one + + + align:start position:0% +solutions at once by calculating it one +fell swoop e to the 18 ok e to the 80 + + align:start position:0% +fell swoop e to the 18 ok e to the 80 + + + align:start position:0% +fell swoop e to the 18 ok e to the 80 +equals ok + + align:start position:0% +equals ok + + + align:start position:0% +equals ok +I'm going to actually write out these + + align:start position:0% +I'm going to actually write out these + + + align:start position:0% +I'm going to actually write out these +guys well obviously the hard part at the + + align:start position:0% +guys well obviously the hard part at the + + + align:start position:0% +guys well obviously the hard part at the +part which is normally going to prevent + + align:start position:0% +part which is normally going to prevent + + + align:start position:0% +part which is normally going to prevent +us from calculating this series + + align:start position:0% +us from calculating this series + + + align:start position:0% +us from calculating this series +explicitly by hand anyway thus I say the + + align:start position:0% +explicitly by hand anyway thus I say the + + + align:start position:0% +explicitly by hand anyway thus I say the +computer can always do it is the value + + align:start position:0% +computer can always do it is the value + + + align:start position:0% +computer can always do it is the value +how do we raise a matrix to a high power + + align:start position:0% +how do we raise a matrix to a high power + + + align:start position:0% +how do we raise a matrix to a high power +you just keep multiplying and + + align:start position:0% +you just keep multiplying and + + + align:start position:0% +you just keep multiplying and +multiplying and multiplying that looks + + align:start position:0% +multiplying and multiplying that looks + + + align:start position:0% +multiplying and multiplying that looks +like a rather forbidding an done + + align:start position:0% +like a rather forbidding an done + + + align:start position:0% +like a rather forbidding an done +promising activity well here it's easy + + align:start position:0% +promising activity well here it's easy + + + align:start position:0% +promising activity well here it's easy +let's see what happens what is a if + + align:start position:0% +let's see what happens what is a if + + + align:start position:0% +let's see what happens what is a if +that's a what's a squared I'm going to + + align:start position:0% +that's a what's a squared I'm going to + + + align:start position:0% +that's a what's a squared I'm going to +have to count like that as part of the + + align:start position:0% +have to count like that as part of the + + + align:start position:0% +have to count like that as part of the +series so that's going to be 0 1 1 0 + + align:start position:0% +series so that's going to be 0 1 1 0 + + + align:start position:0% +series so that's going to be 0 1 1 0 +times 0 1 1 0 which is Dada so 1 but 0 0 + + align:start position:0% +times 0 1 1 0 which is Dada so 1 but 0 0 + + + align:start position:0% +times 0 1 1 0 which is Dada so 1 but 0 0 +3 0 1 4 0 we + + align:start position:0% +3 0 1 4 0 we + + + align:start position:0% +3 0 1 4 0 we +are saved it is the identity now + + align:start position:0% +are saved it is the identity now + + + align:start position:0% +are saved it is the identity now +for this point on we don't have to do + + align:start position:0% +for this point on we don't have to do + + + align:start position:0% +for this point on we don't have to do +any more calculations but I'll do them + + align:start position:0% +any more calculations but I'll do them + + + align:start position:0% +any more calculations but I'll do them +anyway or just - what's + + align:start position:0% +anyway or just - what's + + + align:start position:0% +anyway or just - what's +a cubed don't start from scratch again + + align:start position:0% +a cubed don't start from scratch again + + + align:start position:0% +a cubed don't start from scratch again +God from what time's one from no no no + + align:start position:0% +God from what time's one from no no no + + + align:start position:0% +God from what time's one from no no no +no no 8 8 a cubed is a squared times a + + align:start position:0% +no no 8 8 a cubed is a squared times a + + + align:start position:0% +no no 8 8 a cubed is a squared times a +and a squared is in real life the + + align:start position:0% +and a squared is in real life the + + + align:start position:0% +and a squared is in real life the +identity of course you would do all this + + align:start position:0% +identity of course you would do all this + + + align:start position:0% +identity of course you would do all this +in your head but I'm being a good boy + + align:start position:0% +in your head but I'm being a good boy + + + align:start position:0% +in your head but I'm being a good boy +writing in a lot so this is I the + + align:start position:0% +writing in a lot so this is I the + + + align:start position:0% +writing in a lot so this is I the +identity times a which is a I'll + + align:start position:0% +identity times a which is a I'll + + + align:start position:0% +identity times a which is a I'll +do one more what's a to the fourth now + + align:start position:0% +do one more what's a to the fourth now + + + align:start position:0% +do one more what's a to the fourth now +you would be tempted to say a to the + + align:start position:0% +you would be tempted to say a to the + + + align:start position:0% +you would be tempted to say a to the +fourth is a squared which is I times I + + align:start position:0% +fourth is a squared which is I times I + + + align:start position:0% +fourth is a squared which is I times I +which is I but that would be wrong a to + + align:start position:0% +which is I but that would be wrong a to + + + align:start position:0% +which is I but that would be wrong a to +the fourth is a cubed times a which + + align:start position:0% + + + + align:start position:0% + +is a cubed I've just calculated his a + + align:start position:0% +is a cubed I've just calculated his a + + + align:start position:0% +is a cubed I've just calculated his a +times a a cubed I just calculated with a + + align:start position:0% +times a a cubed I just calculated with a + + + align:start position:0% +times a a cubed I just calculated with a +right and now that is a squared which is + + align:start position:0% +right and now that is a squared which is + + + align:start position:0% +right and now that is a squared which is +the identity it's + + align:start position:0% +the identity it's + + + align:start position:0% +the identity it's +clear this is by this argument it's + + align:start position:0% +clear this is by this argument it's + + + align:start position:0% +clear this is by this argument it's +going to continue in the same way each + + align:start position:0% +going to continue in the same way each + + + align:start position:0% +going to continue in the same way each +time you add an A on the right hand side + + align:start position:0% +time you add an A on the right hand side + + + align:start position:0% +time you add an A on the right hand side +you're going to keep alternating between + + align:start position:0% +you're going to keep alternating between + + + align:start position:0% +you're going to keep alternating between +the identity a the next one will leave + + align:start position:0% +the identity a the next one will leave + + + align:start position:0% +the identity a the next one will leave +the identity the next will be a so the + + align:start position:0% +the identity the next will be a so the + + + align:start position:0% +the identity the next will be a so the +end result is that the first term of the + + align:start position:0% +end result is that the first term of the + + + align:start position:0% +end result is that the first term of the +series is simply the identity the + + align:start position:0% +series is simply the identity the + + + align:start position:0% +series is simply the identity the +next term of the series is a but it's + + align:start position:0% +next term of the series is a but it's + + + align:start position:0% +next term of the series is a but it's +multiplied by T so that is zero should I + + align:start position:0% +multiplied by T so that is zero should I + + + align:start position:0% +multiplied by T so that is zero should I +put it I'll keep the T on the outside + + align:start position:0% +put it I'll keep the T on the outside + + + align:start position:0% +put it I'll keep the T on the outside +remember + + align:start position:0% + + + + align:start position:0% + +when you multiply a matrix by scalar + + align:start position:0% +when you multiply a matrix by scalar + + + align:start position:0% +when you multiply a matrix by scalar +that means multiply every entry by that + + align:start position:0% +that means multiply every entry by that + + + align:start position:0% +that means multiply every entry by that +scalar so this is the matrix 0 T t0 I'll + + align:start position:0% +scalar so this is the matrix 0 T t0 I'll + + + align:start position:0% +scalar so this is the matrix 0 T t0 I'll +do a couple more terms the next term + + align:start position:0% +do a couple more terms the next term + + + align:start position:0% +do a couple more terms the next term +would be well a squared we just + + align:start position:0% +would be well a squared we just + + + align:start position:0% +would be well a squared we just +calculated is the identity so that looks + + align:start position:0% +calculated is the identity so that looks + + + align:start position:0% +calculated is the identity so that looks +like this except now I multiply every + + align:start position:0% +like this except now I multiply every + + + align:start position:0% +like this except now I multiply every +term by T squared over 2 factorial all + + align:start position:0% +term by T squared over 2 factorial all + + + align:start position:0% +term by T squared over 2 factorial all +right what go for broke the + + align:start position:0% +right what go for broke the + + + align:start position:0% +right what go for broke the +next one will be this times + + align:start position:0% +next one will be this times + + + align:start position:0% +next one will be this times +T cubed over 3 factorial and fortunately + + align:start position:0% +T cubed over 3 factorial and fortunately + + + align:start position:0% +T cubed over 3 factorial and fortunately +I run out of room ok + + align:start position:0% + + + + align:start position:0% + +let's calculate that oh maybe + + align:start position:0% + + + + align:start position:0% + +I should do it well + + align:start position:0% +I should do it well + + + align:start position:0% +I should do it well +no we're gonna need that ok + + align:start position:0% +no we're gonna need that ok + + + align:start position:0% +no we're gonna need that ok +let's do it here + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +what's the final answer for e to the 80 + + align:start position:0% +what's the final answer for e to the 80 + + + align:start position:0% +what's the final answer for e to the 80 +it is I have + + align:start position:0% +it is I have + + + align:start position:0% +it is I have +an infinite series of two-by-two + + align:start position:0% +an infinite series of two-by-two + + + align:start position:0% +an infinite series of two-by-two +matrices let's let's look at the term in + + align:start position:0% +matrices let's let's look at the term in + + + align:start position:0% +matrices let's let's look at the term in +the upper left hand corner it's 1 plus + + align:start position:0% +the upper left hand corner it's 1 plus + + + align:start position:0% +the upper left hand corner it's 1 plus + + align:start position:0% + + + align:start position:0% +times T plus 1 times T squared over 2 + + align:start position:0% +times T plus 1 times T squared over 2 + + + align:start position:0% +times T plus 1 times T squared over 2 +factorial plus 0 times T it's going to + + align:start position:0% +factorial plus 0 times T it's going to + + + align:start position:0% +factorial plus 0 times T it's going to +in other words be 1 plus T squared over + + align:start position:0% +in other words be 1 plus T squared over + + + align:start position:0% +in other words be 1 plus T squared over +2 factorial plus the next term I it's + + align:start position:0% +2 factorial plus the next term I it's + + + align:start position:0% +2 factorial plus the next term I it's +not on the board but I think you can see + + align:start position:0% +not on the board but I think you can see + + + align:start position:0% +not on the board but I think you can see +it's this and it continues on in the + + align:start position:0% +it's this and it continues on in the + + + align:start position:0% +it's this and it continues on in the +same way how about the lower left term + + align:start position:0% +same way how about the lower left term + + + align:start position:0% +same way how about the lower left term +well that's 0 plus + + align:start position:0% +well that's 0 plus + + + align:start position:0% +well that's 0 plus +T plus 0 + + align:start position:0% +T plus 0 + + + align:start position:0% +T plus 0 +plus T cubed over 3 factorial and so on + + align:start position:0% +plus T cubed over 3 factorial and so on + + + align:start position:0% +plus T cubed over 3 factorial and so on +so it's T plus T cubed over 3 factorial + + align:start position:0% +so it's T plus T cubed over 3 factorial + + + align:start position:0% +so it's T plus T cubed over 3 factorial +plus T to the fifth over 5 factorial the + + align:start position:0% +plus T to the fifth over 5 factorial the + + + align:start position:0% +plus T to the fifth over 5 factorial the +other terms and the other two corners + + align:start position:0% +other terms and the other two corners + + + align:start position:0% +other terms and the other two corners +are just the same as these this one for + + align:start position:0% +are just the same as these this one for + + + align:start position:0% +are just the same as these this one for +example is 0 plus T plus 0 plus T cubed + + align:start position:0% +example is 0 plus T plus 0 plus T cubed + + + align:start position:0% +example is 0 plus T plus 0 plus T cubed +over 3 factorial and the lower one is 1 + + align:start position:0% +over 3 factorial and the lower one is 1 + + + align:start position:0% +over 3 factorial and the lower one is 1 +plus 0 plus T squared and so on so it's + + align:start position:0% +plus 0 plus T squared and so on so it's + + + align:start position:0% +plus 0 plus T squared and so on so it's +this it's the same as 1 + + align:start position:0% +this it's the same as 1 + + + align:start position:0% +this it's the same as 1 +plus T squared over 2 factorial and so + + align:start position:0% +plus T squared over 2 factorial and so + + + align:start position:0% +plus T squared over 2 factorial and so +on and up here we have T plus T cubed + + align:start position:0% +on and up here we have T plus T cubed + + + align:start position:0% +on and up here we have T plus T cubed +over 3 factorial and so on well + + align:start position:0% + + + + align:start position:0% + +that matrix doesn't look very square but + + align:start position:0% +that matrix doesn't look very square but + + + align:start position:0% +that matrix doesn't look very square but +it is it looks it's infinitely long + + align:start position:0% +it is it looks it's infinitely long + + + align:start position:0% +it is it looks it's infinitely long +physically but it isn't it's got one + + align:start position:0% +physically but it isn't it's got one + + + align:start position:0% +physically but it isn't it's got one +term here one term here one term here + + align:start position:0% +term here one term here one term here + + + align:start position:0% +term here one term here one term here +one term there now all we have to do is + + align:start position:0% +one term there now all we have to do is + + + align:start position:0% +one term there now all we have to do is +make those terms look a little better + + align:start position:0% +make those terms look a little better + + + align:start position:0% +make those terms look a little better +for + + align:start position:0% +for + + + align:start position:0% +for +here I have to rely on the culture which + + align:start position:0% +here I have to rely on the culture which + + + align:start position:0% +here I have to rely on the culture which +you may or may not possess you + + align:start position:0% + + + + align:start position:0% + +would know what these series were if + + align:start position:0% +would know what these series were if + + + align:start position:0% +would know what these series were if +only they alternated their signs if + + align:start position:0% +only they alternated their signs if + + + align:start position:0% +only they alternated their signs if +this were a negative negative negative + + align:start position:0% +this were a negative negative negative + + + align:start position:0% +this were a negative negative negative +that the top would be cosine T and this + + align:start position:0% +that the top would be cosine T and this + + + align:start position:0% +that the top would be cosine T and this +would be sine T but they don't so + + align:start position:0% +would be sine T but they don't so + + + align:start position:0% +would be sine T but they don't so +they are the next best thing they are + + align:start position:0% +they are the next best thing they are + + + align:start position:0% +they are the next best thing they are +hyperbolic + + align:start position:0% +hyperbolic + + + align:start position:0% +hyperbolic +right the top is not costs cosine T but + + align:start position:0% +right the top is not costs cosine T but + + + align:start position:0% +right the top is not costs cosine T but +cosh T the bottom is 60 and + + align:start position:0% + + + + align:start position:0% + +how do we know this because you remember + + align:start position:0% +how do we know this because you remember + + + align:start position:0% +how do we know this because you remember +and what if I don't remember well + + align:start position:0% +and what if I don't remember well + + + align:start position:0% +and what if I don't remember well +you don't now that's + + align:start position:0% +you don't now that's + + + align:start position:0% +you don't now that's +why you come to class well + + align:start position:0% + + + + align:start position:0% + +for those of you who don't and in fact + + align:start position:0% +for those of you who don't and in fact + + + align:start position:0% +for those of you who don't and in fact +remember the nice way to so this is e to + + align:start position:0% +remember the nice way to so this is e to + + + align:start position:0% +remember the nice way to so this is e to +the T plus e to the negative T it should + + align:start position:0% +the T plus e to the negative T it should + + + align:start position:0% +the T plus e to the negative T it should +be over two but I don't have room to put + + align:start position:0% +be over two but I don't have room to put + + + align:start position:0% +be over two but I don't have room to put +in the two this + + align:start position:0% +in the two this + + + align:start position:0% +in the two this +doesn't mean I will omit it it just + + align:start position:0% +doesn't mean I will omit it it just + + + align:start position:0% +doesn't mean I will omit it it just +means I will put + + align:start position:0% +means I will put + + + align:start position:0% +means I will put +it in at the end by + + align:start position:0% +it in at the end by + + + align:start position:0% +it in at the end by +multiplying every entry of this matrix + + align:start position:0% +multiplying every entry of this matrix + + + align:start position:0% +multiplying every entry of this matrix +by one-half so + + align:start position:0% + + + + align:start position:0% + +if you've forgotten what cosh T is it's + + align:start position:0% +if you've forgotten what cosh T is it's + + + align:start position:0% +if you've forgotten what cosh T is it's +e to the T plus e to the negative T + + align:start position:0% +e to the T plus e to the negative T + + + align:start position:0% +e to the T plus e to the negative T +divided by two and the same similar + + align:start position:0% +divided by two and the same similar + + + align:start position:0% +divided by two and the same similar +thing for sin T so there + + align:start position:0% + + + + align:start position:0% + +is your first explicit exponential + + align:start position:0% +is your first explicit exponential + + + align:start position:0% +is your first explicit exponential +matrix calculated according to the + + align:start position:0% +matrix calculated according to the + + + align:start position:0% +matrix calculated according to the +definition and what we have found is the + + align:start position:0% +definition and what we have found is the + + + align:start position:0% +definition and what we have found is the +solution to the system X prime equals y + + align:start position:0% +solution to the system X prime equals y + + + align:start position:0% +solution to the system X prime equals y +Y prime equals x a fundamental matrix in + + align:start position:0% +Y prime equals x a fundamental matrix in + + + align:start position:0% +Y prime equals x a fundamental matrix in +other words our cosh T and since T + + align:start position:0% +other words our cosh T and since T + + + align:start position:0% +other words our cosh T and since T +satisfy both of those satisfy our both + + align:start position:0% +satisfy both of those satisfy our both + + + align:start position:0% +satisfy both of those satisfy our both +solutions for that system now there's + + align:start position:0% +solutions for that system now there's + + + align:start position:0% +solutions for that system now there's +one thing people love the exponential + + align:start position:0% +one thing people love the exponential + + + align:start position:0% +one thing people love the exponential +matrix in particular for and that is the + + align:start position:0% +matrix in particular for and that is the + + + align:start position:0% +matrix in particular for and that is the +ease with which it solves the initial + + align:start position:0% +ease with which it solves the initial + + + align:start position:0% +ease with which it solves the initial +value problem it's exactly what happens + + align:start position:0% +value problem it's exactly what happens + + + align:start position:0% +value problem it's exactly what happens +in studying the single system the single + + align:start position:0% +in studying the single system the single + + + align:start position:0% +in studying the single system the single +equation X prime equals ax but we'll + + align:start position:0% +equation X prime equals ax but we'll + + + align:start position:0% +equation X prime equals ax but we'll +let's do it in general let's + + align:start position:0% + + + + align:start position:0% + +do it in general what's + + align:start position:0% +do it in general what's + + + align:start position:0% +do it in general what's +the initial value problem well the + + align:start position:0% +the initial value problem well the + + + align:start position:0% +the initial value problem well the +initial value problem is we start with + + align:start position:0% +initial value problem is we start with + + + align:start position:0% +initial value problem is we start with +our old system but now I want to put it + + align:start position:0% +our old system but now I want to put it + + + align:start position:0% +our old system but now I want to put it +plug in initial conditions I want the + + align:start position:0% +plug in initial conditions I want the + + + align:start position:0% +plug in initial conditions I want the +particular solution which satisfies the + + align:start position:0% +particular solution which satisfies the + + + align:start position:0% +particular solution which satisfies the +initial in addition let's let's make it + + align:start position:0% +initial in addition let's let's make it + + + align:start position:0% +initial in addition let's let's make it +at zero so to avoid complications to + + align:start position:0% +at zero so to avoid complications to + + + align:start position:0% +at zero so to avoid complications to +avoid a lot of notation this is to be + + align:start position:0% +avoid a lot of notation this is to be + + + align:start position:0% +avoid a lot of notation this is to be +some starting value so this is a + + align:start position:0% +some starting value so this is a + + + align:start position:0% +some starting value so this is a +constant certain constant vector is to + + align:start position:0% +constant certain constant vector is to + + + align:start position:0% +constant certain constant vector is to +be the value of the solution at zero and + + align:start position:0% +be the value of the solution at zero and + + + align:start position:0% +be the value of the solution at zero and +the problem is find what X of T is well + + align:start position:0% + + + + align:start position:0% + +if you're using X the experiential + + align:start position:0% +if you're using X the experiential + + + align:start position:0% +if you're using X the experiential +matrix it's a joke it's a joke so + + align:start position:0% +matrix it's a joke it's a joke so + + + align:start position:0% +matrix it's a joke it's a joke so +I derive it or just do it all right + + align:start position:0% +I derive it or just do it all right + + + align:start position:0% +I derive it or just do it all right +the general solution let's + + align:start position:0% +the general solution let's + + + align:start position:0% +the general solution let's +derive it and then I'll put up the final + + align:start position:0% +derive it and then I'll put up the final + + + align:start position:0% +derive it and then I'll put up the final +formula in a box so that you'll know + + align:start position:0% +formula in a box so that you'll know + + + align:start position:0% +formula in a box so that you'll know +it's important what's the general + + align:start position:0% +it's important what's the general + + + align:start position:0% +it's important what's the general +solution well I did that for you at the + + align:start position:0% +solution well I did that for you at the + + + align:start position:0% +solution well I did that for you at the +beginning of the period once you have an + + align:start position:0% +beginning of the period once you have an + + + align:start position:0% +beginning of the period once you have an +X once you have a fundamental matrix you + + align:start position:0% +X once you have a fundamental matrix you + + + align:start position:0% +X once you have a fundamental matrix you +get the general solution by multiplying + + align:start position:0% +get the general solution by multiplying + + + align:start position:0% +get the general solution by multiplying +it on the right by an arbitrary constant + + align:start position:0% +it on the right by an arbitrary constant + + + align:start position:0% +it on the right by an arbitrary constant +vector so the general solution is going + + align:start position:0% +vector so the general solution is going + + + align:start position:0% +vector so the general solution is going +to be x equals e to the 80 that's my + + align:start position:0% +to be x equals e to the 80 that's my + + + align:start position:0% +to be x equals e to the 80 that's my +super fundamental matrix found without + + align:start position:0% +super fundamental matrix found without + + + align:start position:0% +super fundamental matrix found without +eigenvalues and eigenvectors and this + + align:start position:0% +eigenvalues and eigenvectors and this + + + align:start position:0% +eigenvalues and eigenvectors and this +should be multiplied by some unknown + + align:start position:0% +should be multiplied by some unknown + + + align:start position:0% +should be multiplied by some unknown +constant vector C so the only question + + align:start position:0% +constant vector C so the only question + + + align:start position:0% +constant vector C so the only question +is what should the constant vector C be + + align:start position:0% +is what should the constant vector C be + + + align:start position:0% +is what should the constant vector C be +so we'll plug in to find C I'll plug in + + align:start position:0% +so we'll plug in to find C I'll plug in + + + align:start position:0% +so we'll plug in to find C I'll plug in +0 when T is 0 here I get x is 0 here I + + align:start position:0% +0 when T is 0 here I get x is 0 here I + + + align:start position:0% +0 when T is 0 here I get x is 0 here I +get e to the a times 0 times C now + + align:start position:0% +get e to the a times 0 times C now + + + align:start position:0% +get e to the a times 0 times C now +what's this this is the vector of + + align:start position:0% +what's this this is the vector of + + + align:start position:0% +what's this this is the vector of +initial conditions what's e to the a + + align:start position:0% +initial conditions what's e to the a + + + align:start position:0% +initial conditions what's e to the a +times 0 e to the a times 0 plug + + align:start position:0% +times 0 e to the a times 0 plug + + + align:start position:0% +times 0 e to the a times 0 plug +in T equals 0 what do you get by + + align:start position:0% +in T equals 0 what do you get by + + + align:start position:0% +in T equals 0 what do you get by +I therefore + + align:start position:0% + + + + align:start position:0% + +C + + align:start position:0% +C + + + align:start position:0% +C +is what C is X 0 it's a total joke it's + + align:start position:0% +is what C is X 0 it's a total joke it's + + + align:start position:0% +is what C is X 0 it's a total joke it's +a total joke and the solution is the + + align:start position:0% +a total joke and the solution is the + + + align:start position:0% +a total joke and the solution is the +initial + + align:start position:0% +initial + + + align:start position:0% +initial +value problem is x equals e to + + align:start position:0% +value problem is x equals e to + + + align:start position:0% +value problem is x equals e to +the 80 times + + align:start position:0% +the 80 times + + + align:start position:0% +the 80 times +X + + align:start position:0% +X + + + align:start position:0% +X +it's + + align:start position:0% +it's + + + align:start position:0% +it's +just what it would have been it one + + align:start position:0% +just what it would have been it one + + + align:start position:0% +just what it would have been it one +variable the only difference is that + + align:start position:0% +variable the only difference is that + + + align:start position:0% +variable the only difference is that +here we're allowed to put the C out + + align:start position:0% +here we're allowed to put the C out + + + align:start position:0% +here we're allowed to put the C out +front in other words if I asked you to + + align:start position:0% +front in other words if I asked you to + + + align:start position:0% +front in other words if I asked you to +put in the initial condition you + + align:start position:0% +put in the initial condition you + + + align:start position:0% +put in the initial condition you +probably write x equals little x 0 times + + align:start position:0% +probably write x equals little x 0 times + + + align:start position:0% +probably write x equals little x 0 times +e to the a T and you would be tempted to + + align:start position:0% +e to the a T and you would be tempted to + + + align:start position:0% +e to the a T and you would be tempted to +do the same thing here x equals vector X + + align:start position:0% +do the same thing here x equals vector X + + + align:start position:0% +do the same thing here x equals vector X +equals vector X 0 times e to the a T now + + align:start position:0% +equals vector X 0 times e to the a T now + + + align:start position:0% +equals vector X 0 times e to the a T now +you can't do that and if you try to you + + align:start position:0% +you can't do that and if you try to you + + + align:start position:0% +you can't do that and if you try to you +know MATLAB will hiccup and say illegal + + align:start position:0% +know MATLAB will hiccup and say illegal + + + align:start position:0% +know MATLAB will hiccup and say illegal +operation what's the illegal operation + + align:start position:0% +operation what's the illegal operation + + + align:start position:0% +operation what's the illegal operation +well X is a column vector from + + align:start position:0% +well X is a column vector from + + + align:start position:0% +well X is a column vector from +the system it's a column vector that + + align:start position:0% +the system it's a column vector that + + + align:start position:0% +the system it's a column vector that +means the initial conditions are also a + + align:start position:0% +means the initial conditions are also a + + + align:start position:0% +means the initial conditions are also a +column vector you cannot multiply a + + align:start position:0% +column vector you cannot multiply a + + + align:start position:0% +column vector you cannot multiply a +column vector out front and the square + + align:start position:0% +column vector out front and the square + + + align:start position:0% +column vector out front and the square +matrix afterwards you you can't if + + align:start position:0% +matrix afterwards you you can't if + + + align:start position:0% +matrix afterwards you you can't if +you want to multiply a matrix by a + + align:start position:0% +you want to multiply a matrix by a + + + align:start position:0% +you want to multiply a matrix by a +column vector it has to come afterwards + + align:start position:0% +column vector it has to come afterwards + + + align:start position:0% +column vector it has to come afterwards +so you can do zing-zing there is no zing + + align:start position:0% +so you can do zing-zing there is no zing + + + align:start position:0% +so you can do zing-zing there is no zing +you see there is no you can't put it in + + align:start position:0% +you see there is no you can't put it in + + + align:start position:0% +you see there is no you can't put it in +front it doesn't work so + + align:start position:0% +front it doesn't work so + + + align:start position:0% +front it doesn't work so +it must go behind that's the only place + + align:start position:0% +it must go behind that's the only place + + + align:start position:0% +it must go behind that's the only place +you might get tripped up and as I say if + + align:start position:0% +you might get tripped up and as I say if + + + align:start position:0% +you might get tripped up and as I say if +you try to type that in using MATLAB you + + align:start position:0% +you try to type that in using MATLAB you + + + align:start position:0% +you try to type that in using MATLAB you +will immediately get error messages that + + align:start position:0% +will immediately get error messages that + + + align:start position:0% +will immediately get error messages that +you it's illegal can't do that so anyway + + align:start position:0% +you it's illegal can't do that so anyway + + + align:start position:0% +you it's illegal can't do that so anyway +we've got our solution so + + align:start position:0% +we've got our solution so + + + align:start position:0% +we've got our solution so +here's our there's our system let's say + + align:start position:0% +here's our there's our system let's say + + + align:start position:0% +here's our there's our system let's say +it's our + + align:start position:0% +it's our + + + align:start position:0% +it's our +initial value problem anyway is in pink + + align:start position:0% +initial value problem anyway is in pink + + + align:start position:0% +initial value problem anyway is in pink +and it's solution using the exponential + + align:start position:0% +and it's solution using the exponential + + + align:start position:0% +and it's solution using the exponential +matrix is in green now the + + align:start position:0% +matrix is in green now the + + + align:start position:0% +matrix is in green now the +only problem is we still have to talk a + + align:start position:0% +only problem is we still have to talk a + + + align:start position:0% +only problem is we still have to talk a +little bit more about calculating this + + align:start position:0% +little bit more about calculating this + + + align:start position:0% +little bit more about calculating this +now + + align:start position:0% + + + + align:start position:0% + +the principle warning + + align:start position:0% +the principle warning + + + align:start position:0% +the principle warning +with + + align:start position:0% +with + + + align:start position:0% +with +an exponential matrix is that once + + align:start position:0% +an exponential matrix is that once + + + align:start position:0% +an exponential matrix is that once +you've gotten by the simplest things + + align:start position:0% +you've gotten by the simplest things + + + align:start position:0% +you've gotten by the simplest things +involving it the fact that it solves + + align:start position:0% +involving it the fact that it solves + + + align:start position:0% +involving it the fact that it solves +systems gives you the fundamental matrix + + align:start position:0% +systems gives you the fundamental matrix + + + align:start position:0% +systems gives you the fundamental matrix +for a system then you start flexing your + + align:start position:0% +for a system then you start flexing your + + + align:start position:0% +for a system then you start flexing your +muscles and say oh well I see what else + + align:start position:0% +muscles and say oh well I see what else + + + align:start position:0% +muscles and say oh well I see what else +we can do with this for example the + + align:start position:0% +we can do with this for example the + + + align:start position:0% +we can do with this for example the +reason Exponential's came into being in + + align:start position:0% +reason Exponential's came into being in + + + align:start position:0% +reason Exponential's came into being in +the first place is because of the + + align:start position:0% +the first place is because of the + + + align:start position:0% +the first place is because of the +exponential law right I'll kill anybody + + align:start position:0% +exponential law right I'll kill anybody + + + align:start position:0% +exponential law right I'll kill anybody +types who sends me email say Gary what's + + align:start position:0% +types who sends me email say Gary what's + + + align:start position:0% +types who sends me email say Gary what's +the exponential law alright okay the + + align:start position:0% +the exponential law alright okay the + + + align:start position:0% +the exponential law alright okay the +exponential law would say that e to the + + align:start position:0% +exponential law would say that e to the + + + align:start position:0% +exponential law would say that e to the +a plus B is equal to e to the a times e + + align:start position:0% +a plus B is equal to e to the a times e + + + align:start position:0% +a plus B is equal to e to the a times e +to be the + + align:start position:0% + + + + align:start position:0% + +law of exponents in other words it's the + + align:start position:0% +law of exponents in other words it's the + + + align:start position:0% +law of exponents in other words it's the +thing which makes the exponential + + align:start position:0% +thing which makes the exponential + + + align:start position:0% +thing which makes the exponential +function different from all other + + align:start position:0% +function different from all other + + + align:start position:0% +function different from all other +functions they do satisfy something like + + align:start position:0% +functions they do satisfy something like + + + align:start position:0% +functions they do satisfy something like +that now first of all does this make + + align:start position:0% +that now first of all does this make + + + align:start position:0% +that now first of all does this make +sense that is a other symbols compatible + + align:start position:0% +sense that is a other symbols compatible + + + align:start position:0% +sense that is a other symbols compatible +let's see this is a 2 by 2 matrix this + + align:start position:0% +let's see this is a 2 by 2 matrix this + + + align:start position:0% +let's see this is a 2 by 2 matrix this +is a 2 by 2 matrix so it does make sense + + align:start position:0% +is a 2 by 2 matrix so it does make sense + + + align:start position:0% +is a 2 by 2 matrix so it does make sense +to multiply them and the answer will be + + align:start position:0% +to multiply them and the answer will be + + + align:start position:0% +to multiply them and the answer will be +a 2 by 2 matrix how about here this is a + + align:start position:0% +a 2 by 2 matrix how about here this is a + + + align:start position:0% +a 2 by 2 matrix how about here this is a +2 by 2 matrix add this to it it's still + + align:start position:0% +2 by 2 matrix add this to it it's still + + + align:start position:0% +2 by 2 matrix add this to it it's still +a 2 by 2 matrix e to a 2 by 2 matrix + + align:start position:0% +a 2 by 2 matrix e to a 2 by 2 matrix + + + align:start position:0% +a 2 by 2 matrix e to a 2 by 2 matrix +still comes out to be a 2 by 2 matrix so + + align:start position:0% +still comes out to be a 2 by 2 matrix so + + + align:start position:0% +still comes out to be a 2 by 2 matrix so +both sides are legitimate 2 by 2 + + align:start position:0% +both sides are legitimate 2 by 2 + + + align:start position:0% +both sides are legitimate 2 by 2 +matrices the only question is are they + + align:start position:0% +matrices the only question is are they + + + align:start position:0% +matrices the only question is are they +equal and the answer is not in a pig's + + align:start position:0% +equal and the answer is not in a pig's + + + align:start position:0% +equal and the answer is not in a pig's +eye how + + align:start position:0% + + + + align:start position:0% + +could this be well I didn't make up + + align:start position:0% +could this be well I didn't make up + + + align:start position:0% +could this be well I didn't make up +these laws I just obey them it's + + align:start position:0% +these laws I just obey them it's + + + align:start position:0% +these laws I just obey them it's +all I wish + + align:start position:0% + + + + align:start position:0% + +I had time to do a little calculation to + + align:start position:0% +I had time to do a little calculation to + + + align:start position:0% +I had time to do a little calculation to +show you that it's not true but I can it + + align:start position:0% +show you that it's not true but I can it + + + align:start position:0% +show you that it's not true but I can it +is true in a certain special cases it's + + align:start position:0% +is true in a certain special cases it's + + + align:start position:0% +is true in a certain special cases it's +true in the special case and + + align:start position:0% +true in the special case and + + + align:start position:0% +true in the special case and +this is pretty much if and only if + + align:start position:0% +this is pretty much if and only if + + + align:start position:0% +this is pretty much if and only if +statement the + + align:start position:0% +statement the + + + align:start position:0% +statement the +only case in which it's true is if a and + + align:start position:0% +only case in which it's true is if a and + + + align:start position:0% +only case in which it's true is if a and +B are not arbitrary square matrices but + + align:start position:0% +B are not arbitrary square matrices but + + + align:start position:0% +B are not arbitrary square matrices but +commute with each other you + + align:start position:0% +commute with each other you + + + align:start position:0% +commute with each other you +see if you if you start writing out the + + align:start position:0% +see if you if you start writing out the + + + align:start position:0% +see if you if you start writing out the +series to try to check whether that law + + align:start position:0% +series to try to check whether that law + + + align:start position:0% +series to try to check whether that law +is true you'll get a bunch of terms here + + align:start position:0% +is true you'll get a bunch of terms here + + + align:start position:0% +is true you'll get a bunch of terms here +a bunch of terms here - you'll find that + + align:start position:0% +a bunch of terms here - you'll find that + + + align:start position:0% +a bunch of terms here - you'll find that +those terms are pairwise equal only if + + align:start position:0% +those terms are pairwise equal only if + + + align:start position:0% +those terms are pairwise equal only if +you're allowed to let the bait receipts + + align:start position:0% +you're allowed to let the bait receipts + + + align:start position:0% +you're allowed to let the bait receipts +commute with each other in other words + + align:start position:0% +commute with each other in other words + + + align:start position:0% +commute with each other in other words +if you can't earn a B plus ba into twice + + align:start position:0% +if you can't earn a B plus ba into twice + + + align:start position:0% +if you can't earn a B plus ba into twice +a B then everything will work fine but + + align:start position:0% +a B then everything will work fine but + + + align:start position:0% +a B then everything will work fine but +if you can't do that it will not now + + align:start position:0% +if you can't do that it will not now + + + align:start position:0% +if you can't do that it will not now +when + + align:start position:0% +when + + + align:start position:0% +when +do two square matrices commute with each + + align:start position:0% +do two square matrices commute with each + + + align:start position:0% +do two square matrices commute with each +other the answer is almost never it's + + align:start position:0% +other the answer is almost never it's + + + align:start position:0% +other the answer is almost never it's +just a lucky accident if they do oh but + + align:start position:0% +just a lucky accident if they do oh but + + + align:start position:0% +just a lucky accident if they do oh but +there are three cases of the lucky + + align:start position:0% +there are three cases of the lucky + + + align:start position:0% +there are three cases of the lucky +accident which you have which you should + + align:start position:0% +accident which you have which you should + + + align:start position:0% +accident which you have which you should +know so + + align:start position:0% + + + + align:start position:0% + +the three cases I feel justified calling + + align:start position:0% +the three cases I feel justified calling + + + align:start position:0% +the three cases I feel justified calling +it luck three cases the + + align:start position:0% +it luck three cases the + + + align:start position:0% +it luck three cases the +three oh + + align:start position:0% +three oh + + + align:start position:0% +three oh +well I don't know if again shouldn't do + + align:start position:0% +well I don't know if again shouldn't do + + + align:start position:0% +well I don't know if again shouldn't do +that so + + align:start position:0% + + + + align:start position:0% + +the three most significant there + + align:start position:0% +the three most significant there + + + align:start position:0% +the three most significant there +examples are example number one when a + + align:start position:0% +examples are example number one when a + + + align:start position:0% +examples are example number one when a +is a constant times the identity matrix + + align:start position:0% +is a constant times the identity matrix + + + align:start position:0% +is a constant times the identity matrix +in other words when a is a matrix which + + align:start position:0% +in other words when a is a matrix which + + + align:start position:0% +in other words when a is a matrix which +looks like this that matrix commutes + + align:start position:0% +looks like this that matrix commutes + + + align:start position:0% +looks like this that matrix commutes +with every other square matrix if that's + + align:start position:0% +with every other square matrix if that's + + + align:start position:0% +with every other square matrix if that's +a then this will a be B a is always true + + align:start position:0% +a then this will a be B a is always true + + + align:start position:0% +a then this will a be B a is always true +and you're allowed to use this okay + + align:start position:0% + + + + align:start position:0% + +so that's one case another case when a + + align:start position:0% +so that's one case another case when a + + + align:start position:0% +so that's one case another case when a +is more general is when B is equal to + + align:start position:0% +is more general is when B is equal to + + + align:start position:0% +is more general is when B is equal to +negative a I think you can see that + + align:start position:0% +negative a I think you can see that + + + align:start position:0% +negative a I think you can see that +that's going to work because a times + + align:start position:0% +that's going to work because a times + + + align:start position:0% +that's going to work because a times +minus a is equal to minus a times a yeah + + align:start position:0% +minus a is equal to minus a times a yeah + + + align:start position:0% +minus a is equal to minus a times a yeah +they're both equal to a squared except + + align:start position:0% +they're both equal to a squared except + + + align:start position:0% +they're both equal to a squared except +with a negative sign in front Oh + + align:start position:0% +with a negative sign in front Oh + + + align:start position:0% +with a negative sign in front Oh +the third case is when B is equal to the + + align:start position:0% +the third case is when B is equal to the + + + align:start position:0% +the third case is when B is equal to the +inverse of a because + + align:start position:0% + + + + align:start position:0% + +a a inverse is the same as a inverse a + + align:start position:0% +a a inverse is the same as a inverse a + + + align:start position:0% +a a inverse is the same as a inverse a +they're both the identity of course + + align:start position:0% +they're both the identity of course + + + align:start position:0% +they're both the identity of course +they must have an adverse okay + + align:start position:0% +they must have an adverse okay + + + align:start position:0% +they must have an adverse okay +let's suppose it does now of them this + + align:start position:0% +let's suppose it does now of them this + + + align:start position:0% +let's suppose it does now of them this +is the I think the most important one + + align:start position:0% +is the I think the most important one + + + align:start position:0% +is the I think the most important one +because it leads to this law which is is + + align:start position:0% +because it leads to this law which is is + + + align:start position:0% +because it leads to this law which is is +the form in which you shouldn't that's + + align:start position:0% +the form in which you shouldn't that's + + + align:start position:0% +the form in which you shouldn't that's +forbidden but there's one case of it + + align:start position:0% +forbidden but there's one case of it + + + align:start position:0% +forbidden but there's one case of it +which is forbidden which is not + + align:start position:0% +which is forbidden which is not + + + align:start position:0% +which is forbidden which is not +forbidden and that's here what will it + + align:start position:0% +forbidden and that's here what will it + + + align:start position:0% +forbidden and that's here what will it +say well that will say that e to the a + + align:start position:0% +say well that will say that e to the a + + + align:start position:0% +say well that will say that e to the a +minus + + align:start position:0% +minus + + + align:start position:0% +minus +a is equal to e to the a times e to the + + align:start position:0% +a is equal to e to the a times e to the + + + align:start position:0% +a is equal to e to the a times e to the +negative a so + + align:start position:0% +negative a so + + + align:start position:0% +negative a so +this is true even though the general law + + align:start position:0% +this is true even though the general law + + + align:start position:0% +this is true even though the general law +is false it's because a and negative a + + align:start position:0% +is false it's because a and negative a + + + align:start position:0% +is false it's because a and negative a +commute with each other but now what + + align:start position:0% +commute with each other but now what + + + align:start position:0% +commute with each other but now what +does this say what's e to the 0 matrix + + align:start position:0% +does this say what's e to the 0 matrix + + + align:start position:0% +does this say what's e to the 0 matrix +in other words suppose I take the matrix + + align:start position:0% +in other words suppose I take the matrix + + + align:start position:0% +in other words suppose I take the matrix +that's 0 and plug it into the formula + + align:start position:0% +that's 0 and plug it into the formula + + + align:start position:0% +that's 0 and plug it into the formula +for e what do you get e to the 0 times T + + align:start position:0% +for e what do you get e to the 0 times T + + + align:start position:0% +for e what do you get e to the 0 times T +is I it + + align:start position:0% + + + + align:start position:0% + +has to be a 2 by 2 matrix if it's going + + align:start position:0% +has to be a 2 by 2 matrix if it's going + + + align:start position:0% +has to be a 2 by 2 matrix if it's going +to be anything it's the matrix I so this + + align:start position:0% +to be anything it's the matrix I so this + + + align:start position:0% +to be anything it's the matrix I so this +side is I this + + align:start position:0% +side is I this + + + align:start position:0% +side is I this +side is the exponential matrix and what + + align:start position:0% + + + + align:start position:0% + +does that show it shows that the inverse + + align:start position:0% +does that show it shows that the inverse + + + align:start position:0% +does that show it shows that the inverse +matrix to e to the a is e to the + + align:start position:0% +matrix to e to the a is e to the + + + align:start position:0% +matrix to e to the a is e to the +negative a that's + + align:start position:0% + + + + align:start position:0% + +a very useful fact that the inverse - + + align:start position:0% +a very useful fact that the inverse - + + + align:start position:0% +a very useful fact that the inverse - +this + + align:start position:0% +this + + + align:start position:0% +this +is the main survivor of the exponential + + align:start position:0% +is the main survivor of the exponential + + + align:start position:0% +is the main survivor of the exponential +law general it's false but this standard + + align:start position:0% +law general it's false but this standard + + + align:start position:0% +law general it's false but this standard +corollary the exponential law is true is + + align:start position:0% +corollary the exponential law is true is + + + align:start position:0% +corollary the exponential law is true is +equal to e to the minus a just what you + + align:start position:0% +equal to e to the minus a just what you + + + align:start position:0% +equal to e to the minus a just what you +would dream and hope would be true okay + + align:start position:0% +would dream and hope would be true okay + + + align:start position:0% +would dream and hope would be true okay +I've got exactly two and a half minutes + + align:start position:0% +I've got exactly two and a half minutes + + + align:start position:0% +I've got exactly two and a half minutes +left which to do the impossible all + + align:start position:0% +left which to do the impossible all + + + align:start position:0% +left which to do the impossible all +right the + + align:start position:0% + + + + align:start position:0% + +question is how do you to calculate e to + + align:start position:0% +question is how do you to calculate e to + + + align:start position:0% +question is how do you to calculate e to +the 18 you + + align:start position:0% +the 18 you + + + align:start position:0% +the 18 you +can use series but + + align:start position:0% +can use series but + + + align:start position:0% +can use series but +rarely works it's too hard you know + + align:start position:0% +rarely works it's too hard you know + + + align:start position:0% +rarely works it's too hard you know +there are a few examples you'll have + + align:start position:0% +there are a few examples you'll have + + + align:start position:0% +there are a few examples you'll have +some more for homework but in general + + align:start position:0% +some more for homework but in general + + + align:start position:0% +some more for homework but in general +it's too hard because it's too hard to + + align:start position:0% +it's too hard because it's too hard to + + + align:start position:0% +it's too hard because it's too hard to +calculate the powers of a general matrix + + align:start position:0% +calculate the powers of a general matrix + + + align:start position:0% +calculate the powers of a general matrix +a there's another method which depends + + align:start position:0% +a there's another method which depends + + + align:start position:0% +a there's another method which depends +is useful only for matrices which are + + align:start position:0% +is useful only for matrices which are + + + align:start position:0% +is useful only for matrices which are +symmetric but + + align:start position:0% +symmetric but + + + align:start position:0% +symmetric but +like that + + align:start position:0% +like that + + + align:start position:0% +like that +well it's more than symmetric these two + + align:start position:0% +well it's more than symmetric these two + + + align:start position:0% +well it's more than symmetric these two +have to be the same but you can handle + + align:start position:0% +have to be the same but you can handle + + + align:start position:0% +have to be the same but you can handle +those as you'll see from the homework + + align:start position:0% +those as you'll see from the homework + + + align:start position:0% +those as you'll see from the homework +problems by breaking it up this way and + + align:start position:0% +problems by breaking it up this way and + + + align:start position:0% +problems by breaking it up this way and +using the exponential law so this would + + align:start position:0% +using the exponential law so this would + + + align:start position:0% +using the exponential law so this would +be 0 b b0 see these two matrices commute + + align:start position:0% +be 0 b b0 see these two matrices commute + + + align:start position:0% +be 0 b b0 see these two matrices commute +with each other and therefore I can use + + align:start position:0% +with each other and therefore I can use + + + align:start position:0% +with each other and therefore I can use +the exponential law this + + align:start position:0% + + + + align:start position:0% + +leaves all other cases and here's the + + align:start position:0% +leaves all other cases and here's the + + + align:start position:0% +leaves all other cases and here's the +way to handle all other cases all + + align:start position:0% +way to handle all other cases all + + + align:start position:0% +way to handle all other cases all +other cases in other words if you can't + + align:start position:0% +other cases in other words if you can't + + + align:start position:0% +other cases in other words if you can't +calculate the series of the this trick + + align:start position:0% +calculate the series of the this trick + + + align:start position:0% +calculate the series of the this trick +doesn't work I've + + align:start position:0% +doesn't work I've + + + align:start position:0% +doesn't work I've +done as follows + + align:start position:0% +done as follows + + + align:start position:0% +done as follows +you start with an X an arbitrary + + align:start position:0% +you start with an X an arbitrary + + + align:start position:0% +you start with an X an arbitrary +fundamental matrix not the exponential + + align:start position:0% +fundamental matrix not the exponential + + + align:start position:0% +fundamental matrix not the exponential +matrix you + + align:start position:0% +matrix you + + + align:start position:0% +matrix you +multiply it by its + + align:start position:0% +multiply it by its + + + align:start position:0% +multiply it by its +value at 0 that's a constant matrix and + + align:start position:0% +value at 0 that's a constant matrix and + + + align:start position:0% +value at 0 that's a constant matrix and +you take the inverse of that constant + + align:start position:0% +you take the inverse of that constant + + + align:start position:0% +you take the inverse of that constant +matrix it will have 1 because remember + + align:start position:0% +matrix it will have 1 because remember + + + align:start position:0% +matrix it will have 1 because remember +the fundamental matrix never has + + align:start position:0% +the fundamental matrix never has + + + align:start position:0% +the fundamental matrix never has +determinant 0 so you can always take its + + align:start position:0% +determinant 0 so you can always take its + + + align:start position:0% +determinant 0 so you can always take its +inverse Fredi value of T now what + + align:start position:0% +inverse Fredi value of T now what + + + align:start position:0% +inverse Fredi value of T now what +property does this have it's + + align:start position:0% +property does this have it's + + + align:start position:0% +property does this have it's +a fundamental matrix how + + align:start position:0% +a fundamental matrix how + + + align:start position:0% +a fundamental matrix how +do I know that well because I found all + + align:start position:0% +do I know that well because I found all + + + align:start position:0% +do I know that well because I found all +fundamental matrices for you take any 1 + + align:start position:0% +fundamental matrices for you take any 1 + + + align:start position:0% +fundamental matrices for you take any 1 +multiply it by a square matrix on the + + align:start position:0% +multiply it by a square matrix on the + + + align:start position:0% +multiply it by a square matrix on the +right hand side and you get still a + + align:start position:0% +right hand side and you get still a + + + align:start position:0% +right hand side and you get still a +fundamental matrix and + + align:start position:0% +fundamental matrix and + + + align:start position:0% +fundamental matrix and +what's + + align:start position:0% +what's + + + align:start position:0% +what's +its value at 0 well + + align:start position:0% + + + + align:start position:0% + +it is X of 0 times X of 0 inverse so its + + align:start position:0% +it is X of 0 times X of 0 inverse so its + + + align:start position:0% +it is X of 0 times X of 0 inverse so its +value at 0 is the identity now + + align:start position:0% + + + + align:start position:0% + +e to the 80 has these same two + + align:start position:0% +e to the 80 has these same two + + + align:start position:0% +e to the 80 has these same two +properties namely + + align:start position:0% + + + + align:start position:0% + +it's a fundamental matrix and its value + + align:start position:0% +it's a fundamental matrix and its value + + + align:start position:0% +it's a fundamental matrix and its value +at 0 is the identity conclusion + + align:start position:0% +at 0 is the identity conclusion + + + align:start position:0% +at 0 is the identity conclusion +this is e to the 80 in + + align:start position:0% +this is e to the 80 in + + + align:start position:0% +this is e to the 80 in +other words and that's the + + align:start position:0% +other words and that's the + + + align:start position:0% +other words and that's the +garden-variety method of calculating the + + align:start position:0% +garden-variety method of calculating the + + + align:start position:0% +garden-variety method of calculating the +exponential matrix if you want to give + + align:start position:0% +exponential matrix if you want to give + + + align:start position:0% +exponential matrix if you want to give +it explicitly start with any fundamental + + align:start position:0% +it explicitly start with any fundamental + + + align:start position:0% +it explicitly start with any fundamental +matrix calculated you should forget the + + align:start position:0% +matrix calculated you should forget the + + + align:start position:0% +matrix calculated you should forget the +expression using eigenvalues and + + align:start position:0% +expression using eigenvalues and + + + align:start position:0% +expression using eigenvalues and +eigenvectors and putting the solutions + + align:start position:0% +eigenvectors and putting the solutions + + + align:start position:0% +eigenvectors and putting the solutions +into the columns evaluated + + align:start position:0% +into the columns evaluated + + + align:start position:0% +into the columns evaluated +at zero take its inverse multiply the + + align:start position:0% +at zero take its inverse multiply the + + + align:start position:0% +at zero take its inverse multiply the +two and what you end up with has to be + + align:start position:0% +two and what you end up with has to be + + + align:start position:0% +two and what you end up with has to be +the same as the thing calculated without + + align:start position:0% +the same as the thing calculated without + + + align:start position:0% +the same as the thing calculated without +infinite series okay you'll get lots of + + align:start position:0% +infinite series okay you'll get lots of + + + align:start position:0% +infinite series okay you'll get lots of +practice for homework and tomorrow \ No newline at end of file diff --git a/zzKSn1Y80F4.txt b/zzKSn1Y80F4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7989a1cd365298661fc9b60ed70db34fe041cc9a --- /dev/null +++ b/zzKSn1Y80F4.txt @@ -0,0 +1,7715 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +I also had a couple of students asking + + align:start position:0% +I also had a couple of students asking + + + align:start position:0% +I also had a couple of students asking +me about what do you do after this class + + align:start position:0% +me about what do you do after this class + + + align:start position:0% +me about what do you do after this class +if you want to take more classes and + + align:start position:0% +if you want to take more classes and + + + align:start position:0% +if you want to take more classes and +games if you want to take more classes + + align:start position:0% +games if you want to take more classes + + + align:start position:0% +games if you want to take more classes +in game design if you're thinking about + + align:start position:0% +in game design if you're thinking about + + + align:start position:0% +in game design if you're thinking about +the the spring semester I just wanted to + + align:start position:0% +the the spring semester I just wanted to + + + align:start position:0% +the the spring semester I just wanted to +throw some course numbers up here so + + align:start position:0% +throw some course numbers up here so + + + align:start position:0% +throw some course numbers up here so +there's CMS 301 is introduction to game + + align:start position:0% +there's CMS 301 is introduction to game + + + align:start position:0% +there's CMS 301 is introduction to game +design methods if you're interested in + + align:start position:0% +design methods if you're interested in + + + align:start position:0% +design methods if you're interested in +design research if you're interested in + + align:start position:0% +design research if you're interested in + + + align:start position:0% +design research if you're interested in +design methods and you happen to also be + + align:start position:0% +design methods and you happen to also be + + + align:start position:0% +design methods and you happen to also be +interested in games but you're likely + + align:start position:0% +interested in games but you're likely + + + align:start position:0% +interested in games but you're likely +going to be doing things in design + + align:start position:0% +going to be doing things in design + + + align:start position:0% +going to be doing things in design +elsewhere so that might be application + + align:start position:0% +elsewhere so that might be application + + + align:start position:0% +elsewhere so that might be application +design toy design anything physical + + align:start position:0% +design toy design anything physical + + + align:start position:0% +design toy design anything physical +anything game like whatever the methods + + align:start position:0% +anything game like whatever the methods + + + align:start position:0% +anything game like whatever the methods +are going to teach them there are going + + align:start position:0% +are going to teach them there are going + + + align:start position:0% +are going to teach them there are going +to be useful for all those things but + + align:start position:0% +to be useful for all those things but + + + align:start position:0% +to be useful for all those things but +the class is focused on as using game + + align:start position:0% +the class is focused on as using game + + + align:start position:0% +the class is focused on as using game +design as a way to talk about design + + align:start position:0% +design as a way to talk about design + + + align:start position:0% +design as a way to talk about design +methods so CMS 301 CMS 608 the class + + align:start position:0% +methods so CMS 301 CMS 608 the class + + + align:start position:0% +methods so CMS 301 CMS 608 the class +Philip teaches and I co-teach with them + + align:start position:0% +Philip teaches and I co-teach with them + + + align:start position:0% +Philip teaches and I co-teach with them +on game design so if you want to know + + align:start position:0% +on game design so if you want to know + + + align:start position:0% +on game design so if you want to know +more about how games are designed some + + align:start position:0% +more about how games are designed some + + + align:start position:0% +more about how games are designed some +topics we talk about are things like + + align:start position:0% +topics we talk about are things like + + + align:start position:0% +topics we talk about are things like +game balance seems tuning the projects + + align:start position:0% +game balance seems tuning the projects + + + align:start position:0% +game balance seems tuning the projects +are all board games and card games so + + align:start position:0% +are all board games and card games so + + + align:start position:0% +are all board games and card games so +the entire class is done with analog + + align:start position:0% +the entire class is done with analog + + + align:start position:0% +the entire class is done with analog +game design so we can actually get more + + align:start position:0% +game design so we can actually get more + + + align:start position:0% +game design so we can actually get more +more detail into how rules work how + + align:start position:0% +more detail into how rules work how + + + align:start position:0% +more detail into how rules work how +rules mix together we play a bunch of + + align:start position:0% +rules mix together we play a bunch of + + + align:start position:0% +rules mix together we play a bunch of +board games we analyze them and then we + + align:start position:0% +board games we analyze them and then we + + + align:start position:0% +board games we analyze them and then we +make board games it's very similarly + + align:start position:0% +make board games it's very similarly + + + align:start position:0% +make board games it's very similarly +structured in this class it's team-based + + align:start position:0% +structured in this class it's team-based + + + align:start position:0% +structured in this class it's team-based +you'll do for game design projects in + + align:start position:0% +you'll do for game design projects in + + + align:start position:0% +you'll do for game design projects in +that class there is CMS 610 that is + + align:start position:0% +that class there is CMS 610 that is + + + align:start position:0% +that class there is CMS 610 that is +media industries and systems the art + + align:start position:0% +media industries and systems the art + + + align:start position:0% +media industries and systems the art +science and business of games as topic + + align:start position:0% +science and business of games as topic + + + align:start position:0% +science and business of games as topic +Chris Weaver from Bethesda Softworks he + + align:start position:0% +Chris Weaver from Bethesda Softworks he + + + align:start position:0% +Chris Weaver from Bethesda Softworks he +worked on the Elder Scrolls series for a + + align:start position:0% +worked on the Elder Scrolls series for a + + + align:start position:0% +worked on the Elder Scrolls series for a +while his class is focused on the + + align:start position:0% +while his class is focused on the + + + align:start position:0% +while his class is focused on the +business and publish your side of the + + align:start position:0% +business and publish your side of the + + + align:start position:0% +business and publish your side of the +equation of game development so if + + align:start position:0% +equation of game development so if + + + align:start position:0% +equation of game development so if +you're thinking about doing this as a + + align:start position:0% +you're thinking about doing this as a + + + align:start position:0% +you're thinking about doing this as a +professional career at some point you're + + align:start position:0% +professional career at some point you're + + + align:start position:0% +professional career at some point you're +likely gonna have to deal with + + align:start position:0% +likely gonna have to deal with + + + align:start position:0% +likely gonna have to deal with +publishers either you're going to be + + align:start position:0% +publishers either you're going to be + + + align:start position:0% +publishers either you're going to be +working for one you're the studio will + + align:start position:0% +working for one you're the studio will + + + align:start position:0% +working for one you're the studio will +be working for one or you will be + + align:start position:0% +be working for one or you will be + + + align:start position:0% +be working for one or you will be +pitching one to one yourself so the big + + align:start position:0% +pitching one to one yourself so the big + + + align:start position:0% +pitching one to one yourself so the big +focus of that class is the pitch how do + + align:start position:0% +focus of that class is the pitch how do + + + align:start position:0% +focus of that class is the pitch how do +you pitch your ideas to another group + + align:start position:0% +you pitch your ideas to another group + + + align:start position:0% +you pitch your ideas to another group +and it's also focused on the demo so if + + align:start position:0% +and it's also focused on the demo so if + + + align:start position:0% +and it's also focused on the demo so if +anybody's heard of the term e3 demo + + align:start position:0% +anybody's heard of the term e3 demo + + + align:start position:0% +anybody's heard of the term e3 demo +basically how to make your game look + + align:start position:0% +basically how to make your game look + + + align:start position:0% +basically how to make your game look +good even though it doesn't work + + align:start position:0% +good even though it doesn't work + + + align:start position:0% +good even though it doesn't work +hopefully the game works at the end but + + align:start position:0% +hopefully the game works at the end but + + + align:start position:0% +hopefully the game works at the end but +it's really focused on what do you need + + align:start position:0% +it's really focused on what do you need + + + align:start position:0% +it's really focused on what do you need +in your game in order to communicate + + align:start position:0% +in your game in order to communicate + + + align:start position:0% +in your game in order to communicate +that game to another person in order to + + align:start position:0% +that game to another person in order to + + + align:start position:0% +that game to another person in order to +fit to order to provide funding for your + + align:start position:0% +fit to order to provide funding for your + + + align:start position:0% +fit to order to provide funding for your +game so that's CMS 610 really great + + align:start position:0% +game so that's CMS 610 really great + + + align:start position:0% +game so that's CMS 610 really great +course he has a lot of really good war + + align:start position:0% +course he has a lot of really good war + + + align:start position:0% +course he has a lot of really good war +stories from what the game development + + align:start position:0% +stories from what the game development + + + align:start position:0% +stories from what the game development +process was like from the 80s on up and + + align:start position:0% +process was like from the 80s on up and + + + align:start position:0% +process was like from the 80s on up and +then lastly see ms 617 Sarah and I teach + + align:start position:0% +then lastly see ms 617 Sarah and I teach + + + align:start position:0% +then lastly see ms 617 Sarah and I teach +that course it's called advanced game + + align:start position:0% +that course it's called advanced game + + + align:start position:0% +that course it's called advanced game +studio it's basically an independent + + align:start position:0% +studio it's basically an independent + + + align:start position:0% +studio it's basically an independent +study but with teams to make games you + + align:start position:0% +study but with teams to make games you + + + align:start position:0% +study but with teams to make games you +spend the entire semester making a + + align:start position:0% +spend the entire semester making a + + + align:start position:0% +spend the entire semester making a +single game Sarah and I act kind of as + + align:start position:0% +single game Sarah and I act kind of as + + + align:start position:0% +single game Sarah and I act kind of as +your publisher kind of as your mom and + + align:start position:0% +your publisher kind of as your mom and + + + align:start position:0% +your publisher kind of as your mom and +dad kind of as your mentor basically we + + align:start position:0% +dad kind of as your mentor basically we + + + align:start position:0% +dad kind of as your mentor basically we +are there to help you make your game to + + align:start position:0% +are there to help you make your game to + + + align:start position:0% +are there to help you make your game to +help your game from start to finish on + + align:start position:0% +help your game from start to finish on + + + align:start position:0% +help your game from start to finish on +behalf something that you can you could + + align:start position:0% +behalf something that you can you could + + + align:start position:0% +behalf something that you can you could +either submit to a festival you could + + align:start position:0% +either submit to a festival you could + + + align:start position:0% +either submit to a festival you could +show to another person put in a + + align:start position:0% +show to another person put in a + + + align:start position:0% +show to another person put in a +portfolio before you start this class + + align:start position:0% +portfolio before you start this class + + + align:start position:0% +portfolio before you start this class +you should be in a team already so we'll + + align:start position:0% +you should be in a team already so we'll + + + align:start position:0% +you should be in a team already so we'll +be sending emails out out about this we + + align:start position:0% +be sending emails out out about this we + + + align:start position:0% +be sending emails out out about this we +try to do a few events in January for + + align:start position:0% +try to do a few events in January for + + + align:start position:0% +try to do a few events in January for +networking and for people to meet each + + align:start position:0% +networking and for people to meet each + + + align:start position:0% +networking and for people to meet each +other to form teams but you can form + + align:start position:0% +other to form teams but you can form + + + align:start position:0% +other to form teams but you can form +teams with people you've met in this + + align:start position:0% +teams with people you've met in this + + + align:start position:0% +teams with people you've met in this +class in other classes I have a feeling + + align:start position:0% +class in other classes I have a feeling + + + align:start position:0% +class in other classes I have a feeling +that people who took this class last + + align:start position:0% +that people who took this class last + + + align:start position:0% +that people who took this class last +year are going to be looking for teams + + align:start position:0% +year are going to be looking for teams + + + align:start position:0% +year are going to be looking for teams +for this year so there'll be there'll be + + align:start position:0% +for this year so there'll be there'll be + + + align:start position:0% +for this year so there'll be there'll be +some emails going out around December + + align:start position:0% +some emails going out around December + + + align:start position:0% +some emails going out around December +and January and hopefully a one or two + + align:start position:0% +and January and hopefully a one or two + + + align:start position:0% +and January and hopefully a one or two +events going on at the lab in January + + align:start position:0% +events going on at the lab in January + + + align:start position:0% +events going on at the lab in January +about that um yeah and then if anybody + + align:start position:0% +about that um yeah and then if anybody + + + align:start position:0% +about that um yeah and then if anybody +has any questions about if you want a + + align:start position:0% +has any questions about if you want a + + + align:start position:0% +has any questions about if you want a +minor in in games I'm at MIT if you want + + align:start position:0% +minor in in games I'm at MIT if you want + + + align:start position:0% +minor in in games I'm at MIT if you want +to do a concentration in games at MIT + + align:start position:0% +to do a concentration in games at MIT + + + align:start position:0% +to do a concentration in games at MIT +you can do that through comparative + + align:start position:0% +you can do that through comparative + + + align:start position:0% +you can do that through comparative +Media Studies and writing you can talk + + align:start position:0% +Media Studies and writing you can talk + + + align:start position:0% +Media Studies and writing you can talk +to me about that after class you can + + align:start position:0% +to me about that after class you can + + + align:start position:0% +to me about that after class you can +also go to the CMS w website and talk to + + align:start position:0% +also go to the CMS w website and talk to + + + align:start position:0% +also go to the CMS w website and talk to +Rebecca Shepherdson about that about + + align:start position:0% +Rebecca Shepherdson about that about + + + align:start position:0% +Rebecca Shepherdson about that about +what the requirements are for that but + + align:start position:0% +what the requirements are for that but + + + align:start position:0% +what the requirements are for that but +say full its comparative Media Studies + + align:start position:0% +say full its comparative Media Studies + + + align:start position:0% +say full its comparative Media Studies +it's multiple media but you can also + + align:start position:0% +it's multiple media but you can also + + + align:start position:0% +it's multiple media but you can also +gains is one of those media that you can + + align:start position:0% +gains is one of those media that you can + + + align:start position:0% +gains is one of those media that you can +focus on and concentrate in okay so that + + align:start position:0% +focus on and concentrate in okay so that + + + align:start position:0% +focus on and concentrate in okay so that +is the advertisement part of this class + + align:start position:0% +is the advertisement part of this class + + + align:start position:0% +is the advertisement part of this class +so today we're going to finish up team + + align:start position:0% +so today we're going to finish up team + + + align:start position:0% +so today we're going to finish up team +formation we're going to i'm going to + + align:start position:0% +formation we're going to i'm going to + + + align:start position:0% +formation we're going to i'm going to +introduce the project for deadlines + + align:start position:0% +introduce the project for deadlines + + + align:start position:0% +introduce the project for deadlines +which i briefly mentioned last week and + + align:start position:0% +which i briefly mentioned last week and + + + align:start position:0% +which i briefly mentioned last week and +then we're going to start project for + + align:start position:0% +then we're going to start project for + + + align:start position:0% +then we're going to start project for +today you've got a lot of time today to + + align:start position:0% +today you've got a lot of time today to + + + align:start position:0% +today you've got a lot of time today to +do brainstorming and to do prototyping + + align:start position:0% +do brainstorming and to do prototyping + + + align:start position:0% +do brainstorming and to do prototyping +in your team's recommend we're + + align:start position:0% +in your team's recommend we're + + + align:start position:0% +in your team's recommend we're +recommending that if you're gonna have + + align:start position:0% +recommending that if you're gonna have + + + align:start position:0% +recommending that if you're gonna have +you're going to have eight person teams + + align:start position:0% +you're going to have eight person teams + + + align:start position:0% +you're going to have eight person teams +breaking up into smaller groups to do + + align:start position:0% +breaking up into smaller groups to do + + + align:start position:0% +breaking up into smaller groups to do +some initial prototyping you want + + align:start position:0% +some initial prototyping you want + + + align:start position:0% +some initial prototyping you want +basically think of this as prototyping + + align:start position:0% +basically think of this as prototyping + + + align:start position:0% +basically think of this as prototyping +as a means of brainstorming to come up + + align:start position:0% +as a means of brainstorming to come up + + + align:start position:0% +as a means of brainstorming to come up +with lots of different kinds of + + align:start position:0% +with lots of different kinds of + + + align:start position:0% +with lots of different kinds of +mechanics actually try those mechanics + + align:start position:0% +mechanics actually try those mechanics + + + align:start position:0% +mechanics actually try those mechanics +out and play with them a little bit + + align:start position:0% +out and play with them a little bit + + + align:start position:0% +out and play with them a little bit +before you before you decide on one + + align:start position:0% +before you before you decide on one + + + align:start position:0% +before you before you decide on one +we're giving you a lot of time to do + + align:start position:0% +we're giving you a lot of time to do + + + align:start position:0% +we're giving you a lot of time to do +this this week because you want we want + + align:start position:0% +this this week because you want we want + + + align:start position:0% +this this week because you want we want +to you to have something playable by + + align:start position:0% +to you to have something playable by + + + align:start position:0% +to you to have something playable by +next Monday that's that four teams we've + + align:start position:0% +next Monday that's that four teams we've + + + align:start position:0% +next Monday that's that four teams we've +got it sounds to me like we had five + + align:start position:0% +got it sounds to me like we had five + + + align:start position:0% +got it sounds to me like we had five +topics that were interesting to folks + + align:start position:0% +topics that were interesting to folks + + + align:start position:0% +topics that were interesting to folks +where does anybody still interested in + + align:start position:0% +where does anybody still interested in + + + align:start position:0% +where does anybody still interested in +the malaria topic okay na malaria why do + + align:start position:0% +the malaria topic okay na malaria why do + + + align:start position:0% +the malaria topic okay na malaria why do +you let me come up here and talk to you + + align:start position:0% +you let me come up here and talk to you + + + align:start position:0% +you let me come up here and talk to you +what was it Ebola Ebola yeah so nobody + + align:start position:0% +what was it Ebola Ebola yeah so nobody + + + align:start position:0% +what was it Ebola Ebola yeah so nobody +was interesting that all right so um + + align:start position:0% +was interesting that all right so um + + + align:start position:0% +was interesting that all right so um +I've got early warning leading to early + + align:start position:0% +I've got early warning leading to early + + + align:start position:0% +I've got early warning leading to early +action for heat waves color prevention + + align:start position:0% +action for heat waves color prevention + + + align:start position:0% +action for heat waves color prevention +and hygiene forecast based funding snap + + align:start position:0% +and hygiene forecast based funding snap + + + align:start position:0% +and hygiene forecast based funding snap +and adapting to climate change even + + align:start position:0% +and adapting to climate change even + + + align:start position:0% +and adapting to climate change even +though we've got five topics that does + + align:start position:0% +though we've got five topics that does + + + align:start position:0% +though we've got five topics that does +not mean we need to have one team per + + align:start position:0% +not mean we need to have one team per + + + align:start position:0% +not mean we need to have one team per +topic some of these some teams we can + + align:start position:0% +topic some of these some teams we can + + + align:start position:0% +topic some of these some teams we can +have multiple teams doing welcome the + + align:start position:0% +have multiple teams doing welcome the + + + align:start position:0% +have multiple teams doing welcome the +same topic and that's okay so raise your + + align:start position:0% +same topic and that's okay so raise your + + + align:start position:0% +same topic and that's okay so raise your +hand if you don't think you're on a team + + align:start position:0% +hand if you don't think you're on a team + + + align:start position:0% +hand if you don't think you're on a team +right now okay it's a good portion of + + align:start position:0% +right now okay it's a good portion of + + + align:start position:0% +right now okay it's a good portion of +you so what we're going to do is just + + align:start position:0% +you so what we're going to do is just + + + align:start position:0% +you so what we're going to do is just +like last time we're going to break up + + align:start position:0% +like last time we're going to break up + + + align:start position:0% +like last time we're going to break up +into groups based in the room if you're + + align:start position:0% +into groups based in the room if you're + + + align:start position:0% +into groups based in the room if you're +interested in the topic go to that group + + align:start position:0% +interested in the topic go to that group + + + align:start position:0% +interested in the topic go to that group +talk with those folks if you are in that + + align:start position:0% +talk with those folks if you are in that + + + align:start position:0% +talk with those folks if you are in that +group and you signed off you said that + + align:start position:0% +group and you signed off you said that + + + align:start position:0% +group and you signed off you said that +you are definitely on this team um + + align:start position:0% +you are definitely on this team um + + + align:start position:0% +you are definitely on this team um +through the mailing list identify + + align:start position:0% +through the mailing list identify + + + align:start position:0% +through the mailing list identify +yourself to the group as yes I signed up + + align:start position:0% +yourself to the group as yes I signed up + + + align:start position:0% +yourself to the group as yes I signed up +for this on the mailing list this is + + align:start position:0% +for this on the mailing list this is + + + align:start position:0% +for this on the mailing list this is +what the team is so far here that people + + align:start position:0% +what the team is so far here that people + + + align:start position:0% +what the team is so far here that people +on this team right now and actually to + + align:start position:0% +on this team right now and actually to + + + align:start position:0% +on this team right now and actually to +help that through what I'm going to do + + align:start position:0% +help that through what I'm going to do + + + align:start position:0% +help that through what I'm going to do +is put these on the board they'd have + + align:start position:0% +is put these on the board they'd have + + + align:start position:0% +is put these on the board they'd have +people who signed up for that team come + + align:start position:0% +people who signed up for that team come + + + align:start position:0% +people who signed up for that team come +down first and then everyone else come + + align:start position:0% +down first and then everyone else come + + + align:start position:0% +down first and then everyone else come +down so over here let's do + + align:start position:0% +down so over here let's do + + + align:start position:0% +down so over here let's do +he weighs over here let's do cholera + + align:start position:0% + + + + align:start position:0% + +snap climate change and forecast base + + align:start position:0% +snap climate change and forecast base + + + align:start position:0% +snap climate change and forecast base +funding so if you are already on one of + + align:start position:0% +funding so if you are already on one of + + + align:start position:0% +funding so if you are already on one of +these teams and you said this is the + + align:start position:0% +these teams and you said this is the + + + align:start position:0% +these teams and you said this is the +team I want to be on go to that go to + + align:start position:0% +team I want to be on go to that go to + + + align:start position:0% +team I want to be on go to that go to +that area right now yeah whatever that's + + align:start position:0% +that area right now yeah whatever that's + + + align:start position:0% +that area right now yeah whatever that's +guy all right so heat waves one two + + align:start position:0% +guy all right so heat waves one two + + + align:start position:0% +guy all right so heat waves one two +three four five cholera one two three + + align:start position:0% +three four five cholera one two three + + + align:start position:0% +three four five cholera one two three +four five color six cholera seven are + + align:start position:0% +four five color six cholera seven are + + + align:start position:0% +four five color six cholera seven are +you standing up are you anybody here on + + align:start position:0% +you standing up are you anybody here on + + + align:start position:0% +you standing up are you anybody here on +snap one two three four five six seven + + align:start position:0% +snap one two three four five six seven + + + align:start position:0% +snap one two three four five six seven +cool come on if you're on snap come on + + align:start position:0% +cool come on if you're on snap come on + + + align:start position:0% +cool come on if you're on snap come on +down with the rest of the group adapting + + align:start position:0% +down with the rest of the group adapting + + + align:start position:0% +down with the rest of the group adapting +the climate change if you're on the team + + align:start position:0% +the climate change if you're on the team + + + align:start position:0% +the climate change if you're on the team +if you think you're on that team okay + + align:start position:0% +if you think you're on that team okay + + + align:start position:0% +if you think you're on that team okay +and then forecast based funding if you + + align:start position:0% +and then forecast based funding if you + + + align:start position:0% +and then forecast based funding if you +think you're on that team 12 so far okay + + align:start position:0% +think you're on that team 12 so far okay + + + align:start position:0% +think you're on that team 12 so far okay +all right um so if we're going to one + + align:start position:0% +all right um so if we're going to one + + + align:start position:0% +all right um so if we're going to one +two three four five six was only six + + align:start position:0% +two three four five six was only six + + + align:start position:0% +two three four five six was only six +okay so um move to whatever team that + + align:start position:0% +okay so um move to whatever team that + + + align:start position:0% +okay so um move to whatever team that +you're interested in right now talk with + + align:start position:0% +you're interested in right now talk with + + + align:start position:0% +you're interested in right now talk with +some folks talk about if you're on the + + align:start position:0% +some folks talk about if you're on the + + + align:start position:0% +some folks talk about if you're on the +team already talked about some of the + + align:start position:0% +team already talked about some of the + + + align:start position:0% +team already talked about some of the +things that even talk that you talked + + align:start position:0% +things that even talk that you talked + + + align:start position:0% +things that even talk that you talked +about last week brainstorming wives if + + align:start position:0% +about last week brainstorming wives if + + + align:start position:0% +about last week brainstorming wives if +you want to be on that team talk with + + align:start position:0% +you want to be on that team talk with + + + align:start position:0% +you want to be on that team talk with +the members and ask if you can be on + + align:start position:0% +the members and ask if you can be on + + + align:start position:0% +the members and ask if you can be on +that team basically I'm going to check + + align:start position:0% +that team basically I'm going to check + + + align:start position:0% +that team basically I'm going to check +in any o arm in 10 minutes to see what + + align:start position:0% +in any o arm in 10 minutes to see what + + + align:start position:0% +in any o arm in 10 minutes to see what +we look what it looks like + + align:start position:0% + + + + align:start position:0% + +also wins + + align:start position:0% + + + + align:start position:0% + +Oh + + align:start position:0% + + + + align:start position:0% + +right after this amount of discussion + + align:start position:0% +right after this amount of discussion + + + align:start position:0% +right after this amount of discussion +how many people are still undecided + + align:start position:0% +how many people are still undecided + + + align:start position:0% +how many people are still undecided +about what team they want to be on a + + align:start position:0% +about what team they want to be on a + + + align:start position:0% +about what team they want to be on a +kind of a decided anybody else kind of + + align:start position:0% +kind of a decided anybody else kind of + + + align:start position:0% +kind of a decided anybody else kind of +undecided all right so if you are one + + align:start position:0% +undecided all right so if you are one + + + align:start position:0% +undecided all right so if you are one +hundred percent decided put your name on + + align:start position:0% +hundred percent decided put your name on + + + align:start position:0% +hundred percent decided put your name on +your post it put it up on one of these + + align:start position:0% +your post it put it up on one of these + + + align:start position:0% +your post it put it up on one of these +things do it really really quick come up + + align:start position:0% +things do it really really quick come up + + + align:start position:0% +things do it really really quick come up +put it up sit back down please alright + + align:start position:0% +put it up sit back down please alright + + + align:start position:0% +put it up sit back down please alright +so the dangers of having more than than + + align:start position:0% +so the dangers of having more than than + + + align:start position:0% +so the dangers of having more than than +10 people yeah so I in fact just in fact + + align:start position:0% +10 people yeah so I in fact just in fact + + + align:start position:0% +10 people yeah so I in fact just in fact +that there is already dangers of having + + align:start position:0% +that there is already dangers of having + + + align:start position:0% +that there is already dangers of having +eight people or more but this class was + + align:start position:0% +eight people or more but this class was + + + align:start position:0% +eight people or more but this class was +actually intended for you to actually + + align:start position:0% +actually intended for you to actually + + + align:start position:0% +actually intended for you to actually +feel that pressure right we've got a + + align:start position:0% +feel that pressure right we've got a + + + align:start position:0% +feel that pressure right we've got a +person team you're going to have + + align:start position:0% +person team you're going to have + + + align:start position:0% +person team you're going to have +communication problems of the wazoo that + + align:start position:0% +communication problems of the wazoo that + + + align:start position:0% +communication problems of the wazoo that +tables might be careful um yeah your + + align:start position:0% +tables might be careful um yeah your + + + align:start position:0% +tables might be careful um yeah your +laptop's on it the the and once you get + + align:start position:0% +laptop's on it the the and once you get + + + align:start position:0% +laptop's on it the the and once you get +to a 10-person team what we've seen from + + align:start position:0% +to a 10-person team what we've seen from + + + align:start position:0% +to a 10-person team what we've seen from +previous years is that 10 people teens + + align:start position:0% +previous years is that 10 people teens + + + align:start position:0% +previous years is that 10 people teens +don't act 10 people and larger teams + + align:start position:0% +don't act 10 people and larger teams + + + align:start position:0% +don't act 10 people and larger teams +don't actually outperform six person + + align:start position:0% +don't actually outperform six person + + + align:start position:0% +don't actually outperform six person +teams they actually get about the same + + align:start position:0% +teams they actually get about the same + + + align:start position:0% +teams they actually get about the same +amount done or sometimes less because + + align:start position:0% +amount done or sometimes less because + + + align:start position:0% +amount done or sometimes less because +the communication overhead actually + + align:start position:0% +the communication overhead actually + + + align:start position:0% +the communication overhead actually +breaks down further you might get a lot + + align:start position:0% +breaks down further you might get a lot + + + align:start position:0% +breaks down further you might get a lot +of content done and it turns out to be + + align:start position:0% +of content done and it turns out to be + + + align:start position:0% +of content done and it turns out to be +very uneven in quality because you're + + align:start position:0% +very uneven in quality because you're + + + align:start position:0% +very uneven in quality because you're +multiple people doing content now you + + align:start position:0% +multiple people doing content now you + + + align:start position:0% +multiple people doing content now you +could succeed in breaking your team up + + align:start position:0% +could succeed in breaking your team up + + + align:start position:0% +could succeed in breaking your team up +into little subgroups and be able to + + align:start position:0% +into little subgroups and be able to + + + align:start position:0% +into little subgroups and be able to +organize yourselves that way but we've + + align:start position:0% +organize yourselves that way but we've + + + align:start position:0% +organize yourselves that way but we've +never seen it done successfully in this + + align:start position:0% +never seen it done successfully in this + + + align:start position:0% +never seen it done successfully in this +class with students you know with your + + align:start position:0% +class with students you know with your + + + align:start position:0% +class with students you know with your +level of experience so what we won't + + align:start position:0% +level of experience so what we won't + + + align:start position:0% +level of experience so what we won't +recommend is that for a team well if + + align:start position:0% +recommend is that for a team well if + + + align:start position:0% +recommend is that for a team well if +you've got something like 12 people in + + align:start position:0% +you've got something like 12 people in + + + align:start position:0% +you've got something like 12 people in +all 13 people now in a pile 13 yeah you + + align:start position:0% +all 13 people now in a pile 13 yeah you + + + align:start position:0% +all 13 people now in a pile 13 yeah you +will probably get more done by splitting + + align:start position:0% +will probably get more done by splitting + + + align:start position:0% +will probably get more done by splitting +into two groups if you are deliberately + + align:start position:0% +into two groups if you are deliberately + + + align:start position:0% +into two groups if you are deliberately +brainstorming in order to take advantage + + align:start position:0% +brainstorming in order to take advantage + + + align:start position:0% +brainstorming in order to take advantage +of 30 people that of course they are + + align:start position:0% +of 30 people that of course they are + + + align:start position:0% +of 30 people that of course they are +going to come up with a game that can + + align:start position:0% +going to come up with a game that can + + + align:start position:0% +going to come up with a game that can +only be executed by a very large number + + align:start position:0% +only be executed by a very large number + + + align:start position:0% +only be executed by a very large number +of people well we're just saying is that + + align:start position:0% +of people well we're just saying is that + + + align:start position:0% +of people well we're just saying is that +those games have traditionally not done + + align:start position:0% +those games have traditionally not done + + + align:start position:0% +those games have traditionally not done +very very well in in our class they may + + align:start position:0% +very very well in in our class they may + + + align:start position:0% +very very well in in our class they may +be functional they + + align:start position:0% +be functional they + + + align:start position:0% +be functional they +may actually deliver on the thing that + + align:start position:0% +may actually deliver on the thing that + + + align:start position:0% +may actually deliver on the thing that +you intended to make but we've seen six + + align:start position:0% +you intended to make but we've seen six + + + align:start position:0% +you intended to make but we've seen six +person teams too much more partly + + align:start position:0% +person teams too much more partly + + + align:start position:0% +person teams too much more partly +because the iterator whole lot faster + + align:start position:0% +because the iterator whole lot faster + + + align:start position:0% +because the iterator whole lot faster +and they may have smaller ideas but the + + align:start position:0% +and they may have smaller ideas but the + + + align:start position:0% +and they may have smaller ideas but the +ideas end up being a whole lot more + + align:start position:0% +ideas end up being a whole lot more + + + align:start position:0% +ideas end up being a whole lot more +polished so that's our advice to you it + + align:start position:0% +polished so that's our advice to you it + + + align:start position:0% +polished so that's our advice to you it +is I if they really want to do thirteen + + align:start position:0% +is I if they really want to do thirteen + + + align:start position:0% +is I if they really want to do thirteen +percent team are we going to let them um + + align:start position:0% +percent team are we going to let them um + + + align:start position:0% +percent team are we going to let them um +wow yeah judgment against our better + + align:start position:0% +wow yeah judgment against our better + + + align:start position:0% +wow yeah judgment against our better +judgment we might but we're going to + + align:start position:0% +judgment we might but we're going to + + + align:start position:0% +judgment we might but we're going to +really what we're going to ask I think + + align:start position:0% +really what we're going to ask I think + + + align:start position:0% +really what we're going to ask I think +today is to break up into small into two + + align:start position:0% +today is to break up into small into two + + + align:start position:0% +today is to break up into small into two +smaller teams for brainstorming we + + align:start position:0% +smaller teams for brainstorming we + + + align:start position:0% +smaller teams for brainstorming we +actually we want all the big all the big + + align:start position:0% +actually we want all the big all the big + + + align:start position:0% +actually we want all the big all the big +teams to even break up into smaller + + align:start position:0% +teams to even break up into smaller + + + align:start position:0% +teams to even break up into smaller +teams anyway to do some brainstorming + + align:start position:0% +teams anyway to do some brainstorming + + + align:start position:0% +teams anyway to do some brainstorming +and to do some prototyping once you have + + align:start position:0% +and to do some prototyping once you have + + + align:start position:0% +and to do some prototyping once you have +all that figured out in class today by + + align:start position:0% +all that figured out in class today by + + + align:start position:0% +all that figured out in class today by +the end of class today you can decide + + align:start position:0% +the end of class today you can decide + + + align:start position:0% +the end of class today you can decide +how big you want the team to really be + + align:start position:0% +how big you want the team to really be + + + align:start position:0% +how big you want the team to really be +they were the one issue but we have + + align:start position:0% +they were the one issue but we have + + + align:start position:0% +they were the one issue but we have +those we've got some people who are not + + align:start position:0% +those we've got some people who are not + + + align:start position:0% +those we've got some people who are not +in class today who will be coming in the + + align:start position:0% +in class today who will be coming in the + + + align:start position:0% +in class today who will be coming in the +class about the three that we talked + + align:start position:0% +class about the three that we talked + + + align:start position:0% +class about the three that we talked +about there might be one or two more if + + align:start position:0% +about there might be one or two more if + + + align:start position:0% +about there might be one or two more if +there are any other people like that + + align:start position:0% +there are any other people like that + + + align:start position:0% +there are any other people like that +they will be automatically put on the + + align:start position:0% +they will be automatically put on the + + + align:start position:0% +they will be automatically put on the +smallest of these teams so I'd rather + + align:start position:0% +smallest of these teams so I'd rather + + + align:start position:0% +smallest of these teams so I'd rather +them turn into a six person in cholera + + align:start position:0% +them turn into a six person in cholera + + + align:start position:0% +them turn into a six person in cholera +turn 27 rather than an eighth turned in + + align:start position:0% +turn 27 rather than an eighth turned in + + + align:start position:0% +turn 27 rather than an eighth turned in +a night because he's a person teams are + + align:start position:0% +a night because he's a person teams are + + + align:start position:0% +a night because he's a person teams are +actually just good enough yeah the a + + align:start position:0% +actually just good enough yeah the a + + + align:start position:0% +actually just good enough yeah the a +person teams are just about the size + + align:start position:0% +person teams are just about the size + + + align:start position:0% +person teams are just about the size +that we were hoping for six person teams + + align:start position:0% +that we were hoping for six person teams + + + align:start position:0% +that we were hoping for six person teams +actually to be perfectly honest I think + + align:start position:0% +actually to be perfectly honest I think + + + align:start position:0% +actually to be perfectly honest I think +the sixth person teams have an advantage + + align:start position:0% +the sixth person teams have an advantage + + + align:start position:0% +the sixth person teams have an advantage +but you know that's that's just numbers + + align:start position:0% +but you know that's that's just numbers + + + align:start position:0% +but you know that's that's just numbers +that has that just hard that was + + align:start position:0% +that has that just hard that was + + + align:start position:0% +that has that just hard that was +breakdown yeah the when we have seen a + + align:start position:0% +breakdown yeah the when we have seen a + + + align:start position:0% +breakdown yeah the when we have seen a +10-person team actually work what really + + align:start position:0% +10-person team actually work what really + + + align:start position:0% +10-person team actually work what really +happened was it was ten people eight of + + align:start position:0% +happened was it was ten people eight of + + + align:start position:0% +happened was it was ten people eight of +them worked on the game to have worked + + align:start position:0% +them worked on the game to have worked + + + align:start position:0% +them worked on the game to have worked +on the networking component the + + align:start position:0% +on the networking component the + + + align:start position:0% +on the networking component the +networking component did not work yet + + align:start position:0% +networking component did not work yet + + + align:start position:0% +networking component did not work yet +the game was still as feature complete + + align:start position:0% +the game was still as feature complete + + + align:start position:0% +the game was still as feature complete +as it could be without networking it + + align:start position:0% +as it could be without networking it + + + align:start position:0% +as it could be without networking it +could it could work without the + + align:start position:0% +could it could work without the + + + align:start position:0% +could it could work without the +networking that's not what we're looking + + align:start position:0% +networking that's not what we're looking + + + align:start position:0% +networking that's not what we're looking +for we want the the game that you are + + align:start position:0% +for we want the the game that you are + + + align:start position:0% +for we want the the game that you are +submitting the game that you're creating + + align:start position:0% +submitting the game that you're creating + + + align:start position:0% +submitting the game that you're creating +the design document that you're + + align:start position:0% +the design document that you're + + + align:start position:0% +the design document that you're +submitting to us on wednesday and the + + align:start position:0% +submitting to us on wednesday and the + + + align:start position:0% +submitting to us on wednesday and the +game that you're play testing on monday + + align:start position:0% +game that you're play testing on monday + + + align:start position:0% +game that you're play testing on monday +to be the actual game all those features + + align:start position:0% +to be the actual game all those features + + + align:start position:0% +to be the actual game all those features +that you're saying are going to be in + + align:start position:0% +that you're saying are going to be in + + + align:start position:0% +that you're saying are going to be in +that game to be the actual game that you + + align:start position:0% +that game to be the actual game that you + + + align:start position:0% +that game to be the actual game that you +submit at the end of the semester so + + align:start position:0% +submit at the end of the semester so + + + align:start position:0% +submit at the end of the semester so +don't think of it as well if two people + + align:start position:0% +don't think of it as well if two people + + + align:start position:0% +don't think of it as well if two people +flake then it's back up not do people if + + align:start position:0% +flake then it's back up not do people if + + + align:start position:0% +flake then it's back up not do people if +two people flake if you're too big and + + align:start position:0% +two people flake if you're too big and + + + align:start position:0% +two people flake if you're too big and +you've got to people who don't know + + align:start position:0% +you've got to people who don't know + + + align:start position:0% +you've got to people who don't know +what's going on and they caused some + + align:start position:0% +what's going on and they caused some + + + align:start position:0% +what's going on and they caused some +issues + + align:start position:0% +issues + + + align:start position:0% +issues +it's is going to be a disaster for the + + align:start position:0% +it's is going to be a disaster for the + + + align:start position:0% +it's is going to be a disaster for the +entire team did anybody in previous so + + align:start position:0% +entire team did anybody in previous so + + + align:start position:0% +entire team did anybody in previous so +this year all of the projects to and + + align:start position:0% +this year all of the projects to and + + + align:start position:0% +this year all of the projects to and +private three teams were actually bigger + + align:start position:0% +private three teams were actually bigger + + + align:start position:0% +private three teams were actually bigger +than we've done them in LA in previous + + align:start position:0% +than we've done them in LA in previous + + + align:start position:0% +than we've done them in LA in previous +years previous years we were there about + + align:start position:0% +years previous years we were there about + + + align:start position:0% +years previous years we were there about +four people maybe five tops I me how do + + align:start position:0% +four people maybe five tops I me how do + + + align:start position:0% +four people maybe five tops I me how do +you do six and seven I think right did + + align:start position:0% +you do six and seven I think right did + + + align:start position:0% +you do six and seven I think right did +anybody feel like with seven people they + + align:start position:0% +anybody feel like with seven people they + + + align:start position:0% +anybody feel like with seven people they +got a communication method that worked + + align:start position:0% +got a communication method that worked + + + align:start position:0% +got a communication method that worked +really well like already like okay I see + + align:start position:0% +really well like already like okay I see + + + align:start position:0% +really well like already like okay I see +what what was that what was the method + + align:start position:0% + + + + align:start position:0% + +yeah I mean it's the sort of thing they + + align:start position:0% +yeah I mean it's the sort of thing they + + + align:start position:0% +yeah I mean it's the sort of thing they +could what whatever method you use will + + align:start position:0% +could what whatever method you use will + + + align:start position:0% +could what whatever method you use will +definitely improve with practice right + + align:start position:0% +definitely improve with practice right + + + align:start position:0% +definitely improve with practice right +so so so if you got something that sort + + align:start position:0% +so so so if you got something that sort + + + align:start position:0% +so so so if you got something that sort +of worked well something to try again + + align:start position:0% +of worked well something to try again + + + align:start position:0% +of worked well something to try again +but the fact that most people didn't you + + align:start position:0% +but the fact that most people didn't you + + + align:start position:0% +but the fact that most people didn't you +know gives us and it should already give + + align:start position:0% +know gives us and it should already give + + + align:start position:0% +know gives us and it should already give +you some warning of what a large team is + + align:start position:0% +you some warning of what a large team is + + + align:start position:0% +you some warning of what a large team is +going to feel like it's going to be + + align:start position:0% +going to feel like it's going to be + + + align:start position:0% +going to feel like it's going to be +tough for the structure of the class on + + align:start position:0% +tough for the structure of the class on + + + align:start position:0% +tough for the structure of the class on +Wednesday we're going to be talking + + align:start position:0% +Wednesday we're going to be talking + + + align:start position:0% +Wednesday we're going to be talking +about more of the requirements the + + align:start position:0% +about more of the requirements the + + + align:start position:0% +about more of the requirements the +aesthetic requirements for project floor + + align:start position:0% +aesthetic requirements for project floor + + + align:start position:0% +aesthetic requirements for project floor +we talking a little bit well we have + + align:start position:0% +we talking a little bit well we have + + + align:start position:0% +we talking a little bit well we have +another basically another design + + align:start position:0% +another basically another design + + + align:start position:0% +another basically another design +discussion next wednesday on monday + + align:start position:0% +discussion next wednesday on monday + + + align:start position:0% +discussion next wednesday on monday +we're having a short design discussion + + align:start position:0% +we're having a short design discussion + + + align:start position:0% +we're having a short design discussion +about educational games and then we'll + + align:start position:0% +about educational games and then we'll + + + align:start position:0% +about educational games and then we'll +have a one of our first discussions + + align:start position:0% +have a one of our first discussions + + + align:start position:0% +have a one of our first discussions +trying to talk about some of the person + + align:start position:0% +trying to talk about some of the person + + + align:start position:0% +trying to talk about some of the person +the person person issues we see in + + align:start position:0% +the person person issues we see in + + + align:start position:0% +the person person issues we see in +making games but in this case it's team + + align:start position:0% +making games but in this case it's team + + + align:start position:0% +making games but in this case it's team +dynamics and how to identify team + + align:start position:0% +dynamics and how to identify team + + + align:start position:0% +dynamics and how to identify team +dynamics I'll have a couple more talks + + align:start position:0% +dynamics I'll have a couple more talks + + + align:start position:0% +dynamics I'll have a couple more talks +like that to kind of help you get used + + align:start position:0% +like that to kind of help you get used + + + align:start position:0% +like that to kind of help you get used +to running in a bigger team but between + + align:start position:0% +to running in a bigger team but between + + + align:start position:0% +to running in a bigger team but between +now and next monday we're hoping in + + align:start position:0% +now and next monday we're hoping in + + + align:start position:0% +now and next monday we're hoping in +class to give you a plenty of time to + + align:start position:0% +class to give you a plenty of time to + + + align:start position:0% +class to give you a plenty of time to +actually work on some of the send one of + + align:start position:0% +actually work on some of the send one of + + + align:start position:0% +actually work on some of the send one of +the biggest issues with working in a big + + align:start position:0% +the biggest issues with working in a big + + + align:start position:0% +the biggest issues with working in a big +team is just figuring out what is what + + align:start position:0% +team is just figuring out what is what + + + align:start position:0% +team is just figuring out what is what +is that core thing that you're actually + + align:start position:0% +is that core thing that you're actually + + + align:start position:0% +is that core thing that you're actually +making what's the thing you're trying to + + align:start position:0% +making what's the thing you're trying to + + + align:start position:0% +making what's the thing you're trying to +communicate to each other we've talked + + align:start position:0% +communicate to each other we've talked + + + align:start position:0% +communicate to each other we've talked +to talked about how you can use the + + align:start position:0% +to talked about how you can use the + + + align:start position:0% +to talked about how you can use the +division document for that and I you can + + align:start position:0% +division document for that and I you can + + + align:start position:0% +division document for that and I you can +use the prototyping the actual prototype + + align:start position:0% +use the prototyping the actual prototype + + + align:start position:0% +use the prototyping the actual prototype +you make for that but often it is just + + align:start position:0% +you make for that but often it is just + + + align:start position:0% +you make for that but often it is just +having everybody in the same room at the + + align:start position:0% +having everybody in the same room at the + + + align:start position:0% +having everybody in the same room at the +same time talking and just working + + align:start position:0% +same time talking and just working + + + align:start position:0% +same time talking and just working +together so we're trying to give you as + + align:start position:0% +together so we're trying to give you as + + + align:start position:0% +together so we're trying to give you as +much time as you can in class because + + align:start position:0% +much time as you can in class because + + + align:start position:0% +much time as you can in class because +you know hard enough to get six people + + align:start position:0% +you know hard enough to get six people + + + align:start position:0% +you know hard enough to get six people +outside of class to me to let let let + + align:start position:0% +outside of class to me to let let let + + + align:start position:0% +outside of class to me to let let let +alone a a person team right so we're + + align:start position:0% +alone a a person team right so we're + + + align:start position:0% +alone a a person team right so we're +going to give you more time inc + + align:start position:0% +going to give you more time inc + + + align:start position:0% +going to give you more time inc +to meet up with with each other that + + align:start position:0% +to meet up with with each other that + + + align:start position:0% +to meet up with with each other that +does not mean that you should be + + align:start position:0% +does not mean that you should be + + + align:start position:0% +does not mean that you should be +spending all your time and class + + align:start position:0% +spending all your time and class + + + align:start position:0% +spending all your time and class +planning on getting your face to face + + align:start position:0% +planning on getting your face to face + + + align:start position:0% +planning on getting your face to face +coding done that's actually a waste of + + align:start position:0% +coding done that's actually a waste of + + + align:start position:0% +coding done that's actually a waste of +time because you could be talking to + + align:start position:0% +time because you could be talking to + + + align:start position:0% +time because you could be talking to +each other you can do that but things + + align:start position:0% +each other you can do that but things + + + align:start position:0% +each other you can do that but things +like code reviews code reviews stand-up + + align:start position:0% +like code reviews code reviews stand-up + + + align:start position:0% +like code reviews code reviews stand-up +meetings on things like that okay all + + align:start position:0% +meetings on things like that okay all + + + align:start position:0% +meetings on things like that okay all +right so we're going to put this on hold + + align:start position:0% +right so we're going to put this on hold + + + align:start position:0% +right so we're going to put this on hold +for a second I'm going to go over the + + align:start position:0% + + + + align:start position:0% + +very quickly the deadlines and then + + align:start position:0% +very quickly the deadlines and then + + + align:start position:0% +very quickly the deadlines and then +we're going to take a break and come + + align:start position:0% +we're going to take a break and come + + + align:start position:0% +we're going to take a break and come +back so if this will move forward all + + align:start position:0% +back so if this will move forward all + + + align:start position:0% +back so if this will move forward all +right so why did I react so strongly + + align:start position:0% +right so why did I react so strongly + + + align:start position:0% +right so why did I react so strongly +about the animal crossing all these + + align:start position:0% +about the animal crossing all these + + + align:start position:0% +about the animal crossing all these +sorts of minigames because what we're + + align:start position:0% +sorts of minigames because what we're + + + align:start position:0% +sorts of minigames because what we're +asking you to do whoa don't do that all + + align:start position:0% +asking you to do whoa don't do that all + + + align:start position:0% +asking you to do whoa don't do that all +right so what we're asking to do is + + align:start position:0% +right so what we're asking to do is + + + align:start position:0% +right so what we're asking to do is +create a small fully functional polished + + align:start position:0% +create a small fully functional polished + + + align:start position:0% +create a small fully functional polished +browser game one of those mini games + + align:start position:0% +browser game one of those mini games + + + align:start position:0% +browser game one of those mini games +would count as a small fully functional + + align:start position:0% +would count as a small fully functional + + + align:start position:0% +would count as a small fully functional +well-polished browser game we're asking + + align:start position:0% +well-polished browser game we're asking + + + align:start position:0% +well-polished browser game we're asking +you to use the design iteration + + align:start position:0% +you to use the design iteration + + + align:start position:0% +you to use the design iteration +techniques you've used in the past what + + align:start position:0% +techniques you've used in the past what + + + align:start position:0% +techniques you've used in the past what +does that mean we're actually talking + + align:start position:0% +does that mean we're actually talking + + + align:start position:0% +does that mean we're actually talking +about the same design scope as the + + align:start position:0% +about the same design scope as the + + + align:start position:0% +about the same design scope as the +previous two projects is just you spent + + align:start position:0% +previous two projects is just you spent + + + align:start position:0% +previous two projects is just you spent +more time on it to actually get it + + align:start position:0% +more time on it to actually get it + + + align:start position:0% +more time on it to actually get it +working exactly the way you'd want it to + + align:start position:0% +working exactly the way you'd want it to + + + align:start position:0% +working exactly the way you'd want it to +work if you had maybe slightly larger so + + align:start position:0% +work if you had maybe slightly larger so + + + align:start position:0% +work if you had maybe slightly larger so +if your previous two projects had maybe + + align:start position:0% +if your previous two projects had maybe + + + align:start position:0% +if your previous two projects had maybe +one core mechanic and one supplementary + + align:start position:0% +one core mechanic and one supplementary + + + align:start position:0% +one core mechanic and one supplementary +there might be two supplementary + + align:start position:0% +there might be two supplementary + + + align:start position:0% +there might be two supplementary +mechanics to that core but that's about + + align:start position:0% +mechanics to that core but that's about + + + align:start position:0% +mechanics to that core but that's about +it if you've got a game that has an + + align:start position:0% +it if you've got a game that has an + + + align:start position:0% +it if you've got a game that has an +overworld then the overworld should be + + align:start position:0% +overworld then the overworld should be + + + align:start position:0% +overworld then the overworld should be +the bulk of your game if you're spinning + + align:start position:0% +the bulk of your game if you're spinning + + + align:start position:0% +the bulk of your game if you're spinning +if the minigames that you decided to + + align:start position:0% +if the minigames that you decided to + + + align:start position:0% +if the minigames that you decided to +make are the same size is that overworld + + align:start position:0% +make are the same size is that overworld + + + align:start position:0% +make are the same size is that overworld +in scope that's already way too over + + align:start position:0% +in scope that's already way too over + + + align:start position:0% +in scope that's already way too over +scoped that make sense it's an eight + + align:start position:0% +scoped that make sense it's an eight + + + align:start position:0% +scoped that make sense it's an eight +week project we're giving you you've got + + align:start position:0% +week project we're giving you you've got + + + align:start position:0% +week project we're giving you you've got +about two weeks to concept and prototype + + align:start position:0% +about two weeks to concept and prototype + + + align:start position:0% +about two weeks to concept and prototype +multiple game like multiple game + + align:start position:0% +multiple game like multiple game + + + align:start position:0% +multiple game like multiple game +experiences so we're asking for today + + align:start position:0% +experiences so we're asking for today + + + align:start position:0% +experiences so we're asking for today +and tomorrow on Wednesday is you're not + + align:start position:0% +and tomorrow on Wednesday is you're not + + + align:start position:0% +and tomorrow on Wednesday is you're not +just prototyping one game you're + + align:start position:0% +just prototyping one game you're + + + align:start position:0% +just prototyping one game you're +prototyping lots and lots of different + + align:start position:0% +prototyping lots and lots of different + + + align:start position:0% +prototyping lots and lots of different +little games looking at all those games + + align:start position:0% +little games looking at all those games + + + align:start position:0% +little games looking at all those games +you actually have time to spend you're + + align:start position:0% +you actually have time to spend you're + + + align:start position:0% +you actually have time to spend you're +gonna have time to spend on multiple + + align:start position:0% +gonna have time to spend on multiple + + + align:start position:0% +gonna have time to spend on multiple +different prototypes rather than just a + + align:start position:0% +different prototypes rather than just a + + + align:start position:0% +different prototypes rather than just a +single prototype that you iterate on so + + align:start position:0% +single prototype that you iterate on so + + + align:start position:0% +single prototype that you iterate on so +we're asking is if you got an eight + + align:start position:0% +we're asking is if you got an eight + + + align:start position:0% +we're asking is if you got an eight +person team + + align:start position:0% +person team + + + align:start position:0% +person team +break yourself into two groups of four + + align:start position:0% +break yourself into two groups of four + + + align:start position:0% +break yourself into two groups of four +four groups of to create some really + + align:start position:0% +four groups of to create some really + + + align:start position:0% +four groups of to create some really +small bord gáis me looking things some + + align:start position:0% +small bord gáis me looking things some + + + align:start position:0% +small bord gáis me looking things some +very small interactions maybe they're + + align:start position:0% +very small interactions maybe they're + + + align:start position:0% +very small interactions maybe they're +playable maybe there's something you + + align:start position:0% +playable maybe there's something you + + + align:start position:0% +playable maybe there's something you +just described but really go big blue + + align:start position:0% +just described but really go big blue + + + align:start position:0% +just described but really go big blue +sky and try to think of all the + + align:start position:0% +sky and try to think of all the + + + align:start position:0% +sky and try to think of all the +different things that can happen with + + align:start position:0% +different things that can happen with + + + align:start position:0% +different things that can happen with +with these topics that you're dealing + + align:start position:0% +with these topics that you're dealing + + + align:start position:0% +with these topics that you're dealing +with are very large and we make sure + + align:start position:0% +with are very large and we make sure + + + align:start position:0% +with are very large and we make sure +that your design is grounded very very + + align:start position:0% +that your design is grounded very very + + + align:start position:0% +that your design is grounded very very +well granted in the sources that we've + + align:start position:0% +well granted in the sources that we've + + + align:start position:0% +well granted in the sources that we've +been given by the client there's gonna + + align:start position:0% +been given by the client there's gonna + + + align:start position:0% +been given by the client there's gonna +be multiple times when they'll be here + + align:start position:0% +be multiple times when they'll be here + + + align:start position:0% +be multiple times when they'll be here +to see your games and talk about your + + align:start position:0% +to see your games and talk about your + + + align:start position:0% +to see your games and talk about your +games they'll be on your email so that + + align:start position:0% +games they'll be on your email so that + + + align:start position:0% +games they'll be on your email so that +you can ask some questions about that as + + align:start position:0% +you can ask some questions about that as + + + align:start position:0% +you can ask some questions about that as +well so design constraints use all the + + align:start position:0% +well so design constraints use all the + + + align:start position:0% +well so design constraints use all the +mechanics that we've been practicing in + + align:start position:0% +mechanics that we've been practicing in + + + align:start position:0% +mechanics that we've been practicing in +class on with your previous projects not + + align:start position:0% +class on with your previous projects not + + + align:start position:0% +class on with your previous projects not +all not all the mechanics simultaneously + + align:start position:0% +all not all the mechanics simultaneously + + + align:start position:0% +all not all the mechanics simultaneously +use any of those make any of those + + align:start position:0% +use any of those make any of those + + + align:start position:0% +use any of those make any of those +mechanics so it could have trade-offs it + + align:start position:0% +mechanics so it could have trade-offs it + + + align:start position:0% +mechanics so it could have trade-offs it +could have randomest it is not required + + align:start position:0% +could have randomest it is not required + + + align:start position:0% +could have randomest it is not required +to have both it's required to have + + align:start position:0% +to have both it's required to have + + + align:start position:0% +to have both it's required to have +whatever it takes for the project that + + align:start position:0% +whatever it takes for the project that + + + align:start position:0% +whatever it takes for the project that +you're for the topic that you're working + + align:start position:0% +you're for the topic that you're working + + + align:start position:0% +you're for the topic that you're working +on whatever makes sense for the topic + + align:start position:0% +on whatever makes sense for the topic + + + align:start position:0% +on whatever makes sense for the topic +that you're working on those top to tend + + align:start position:0% +that you're working on those top to tend + + + align:start position:0% +that you're working on those top to tend +to be in the realm of what those topics + + align:start position:0% +to be in the realm of what those topics + + + align:start position:0% +to be in the realm of what those topics +kind of lean themselves towards but if + + align:start position:0% +kind of lean themselves towards but if + + + align:start position:0% +kind of lean themselves towards but if +you find something else and you want to + + align:start position:0% +you find something else and you want to + + + align:start position:0% +you find something else and you want to +use that something else great spend some + + align:start position:0% +use that something else great spend some + + + align:start position:0% +use that something else great spend some +time really working on it I spent a + + align:start position:0% +time really working on it I spent a + + + align:start position:0% +time really working on it I spent a +couple weeks working on it before you + + align:start position:0% +couple weeks working on it before you + + + align:start position:0% +couple weeks working on it before you +make a full commitment so your target + + align:start position:0% +make a full commitment so your target + + + align:start position:0% +make a full commitment so your target +audience since each of those topics has + + align:start position:0% +audience since each of those topics has + + + align:start position:0% +audience since each of those topics has +on their own target audiences which they + + align:start position:0% +on their own target audiences which they + + + align:start position:0% +on their own target audiences which they +talked about the top three are the ones + + align:start position:0% +talked about the top three are the ones + + + align:start position:0% +talked about the top three are the ones +to really focus on on depending on your + + align:start position:0% +to really focus on on depending on your + + + align:start position:0% +to really focus on on depending on your +topic so Red Cross staff and volunteers + + align:start position:0% +topic so Red Cross staff and volunteers + + + align:start position:0% +topic so Red Cross staff and volunteers +so people who are knowledgeable and + + align:start position:0% +so people who are knowledgeable and + + + align:start position:0% +so people who are knowledgeable and +motivated about the topic already who + + align:start position:0% +motivated about the topic already who + + + align:start position:0% +motivated about the topic already who +just need a little bit extra information + + align:start position:0% +just need a little bit extra information + + + align:start position:0% +just need a little bit extra information +community organizers arm and then youth + + align:start position:0% +community organizers arm and then youth + + + align:start position:0% +community organizers arm and then youth +people who are motivated but maybe not + + align:start position:0% +people who are motivated but maybe not + + + align:start position:0% +people who are motivated but maybe not +knowledgeable about the topic again the + + align:start position:0% +knowledgeable about the topic again the + + + align:start position:0% +knowledgeable about the topic again the +other requirements these are we are + + align:start position:0% +other requirements these are we are + + + align:start position:0% +other requirements these are we are +holding you to these maximum play length + + align:start position:0% +holding you to these maximum play length + + + align:start position:0% +holding you to these maximum play length +to ten minutes single or multiplayer + + align:start position:0% +to ten minutes single or multiplayer + + + align:start position:0% +to ten minutes single or multiplayer +game test your user interface well it + + align:start position:0% +game test your user interface well it + + + align:start position:0% +game test your user interface well it +must use and play audio for the player + + align:start position:0% +must use and play audio for the player + + + align:start position:0% +must use and play audio for the player +unless audio is absolutely not required + + align:start position:0% +unless audio is absolutely not required + + + align:start position:0% +unless audio is absolutely not required +for your design if your design really + + align:start position:0% +for your design if your design really + + + align:start position:0% +for your design if your design really +does not need audio then don't use audio + + align:start position:0% +does not need audio then don't use audio + + + align:start position:0% +does not need audio then don't use audio +but if it has if it's a it's a web + + align:start position:0% +but if it has if it's a it's a web + + + align:start position:0% +but if it has if it's a it's a web +browser experience there's probably + + align:start position:0% +browser experience there's probably + + + align:start position:0% +browser experience there's probably +should be some way to use audio as a + + align:start position:0% +should be some way to use audio as a + + + align:start position:0% +should be some way to use audio as a +method of getting feedback to the player + + align:start position:0% +method of getting feedback to the player + + + align:start position:0% +method of getting feedback to the player +so it could be as very simple as a ding + + align:start position:0% +so it could be as very simple as a ding + + + align:start position:0% +so it could be as very simple as a ding +when something happens + + align:start position:0% +when something happens + + + align:start position:0% +when something happens +that's okay for this project what + + align:start position:0% +that's okay for this project what + + + align:start position:0% +that's okay for this project what +matters to us is that you have a unified + + align:start position:0% +matters to us is that you have a unified + + + align:start position:0% +matters to us is that you have a unified +aesthetic which we'll talk about on + + align:start position:0% +aesthetic which we'll talk about on + + + align:start position:0% +aesthetic which we'll talk about on +Wednesday what exactly we mean by that + + align:start position:0% +Wednesday what exactly we mean by that + + + align:start position:0% +Wednesday what exactly we mean by that +and then also we're asking to give + + align:start position:0% +and then also we're asking to give + + + align:start position:0% +and then also we're asking to give +design thought to spectating users in + + align:start position:0% +design thought to spectating users in + + + align:start position:0% +design thought to spectating users in +the final presentation you're going to + + align:start position:0% +the final presentation you're going to + + + align:start position:0% +the final presentation you're going to +be presenting the games on the projector + + align:start position:0% +be presenting the games on the projector + + + align:start position:0% +be presenting the games on the projector +people going to be watching the games + + align:start position:0% +people going to be watching the games + + + align:start position:0% +people going to be watching the games +being played they should be able to + + align:start position:0% +being played they should be able to + + + align:start position:0% +being played they should be able to +understand how the game has worked just + + align:start position:0% +understand how the game has worked just + + + align:start position:0% +understand how the game has worked just +by watching it maybe they might need to + + align:start position:0% +by watching it maybe they might need to + + + align:start position:0% +by watching it maybe they might need to +watch it one or two times to figure it + + align:start position:0% +watch it one or two times to figure it + + + align:start position:0% +watch it one or two times to figure it +out but they should be able to figure + + align:start position:0% +out but they should be able to figure + + + align:start position:0% +out but they should be able to figure +out what are the things that are going + + align:start position:0% +out what are the things that are going + + + align:start position:0% +out what are the things that are going +on in the game and how are those how all + + align:start position:0% +on in the game and how are those how all + + + align:start position:0% +on in the game and how are those how all +those interactions happening so your + + align:start position:0% +those interactions happening so your + + + align:start position:0% +those interactions happening so your +deliverables that was from up till now + + align:start position:0% +deliverables that was from up till now + + + align:start position:0% +deliverables that was from up till now +so on Wednesday turn into stellar a high + + align:start position:0% +so on Wednesday turn into stellar a high + + + align:start position:0% +so on Wednesday turn into stellar a high +level design doc or back to box copy the + + align:start position:0% +level design doc or back to box copy the + + + align:start position:0% +level design doc or back to box copy the +same form we've been using on previously + + align:start position:0% +same form we've been using on previously + + + align:start position:0% +same form we've been using on previously +some kind of vision statement that says + + align:start position:0% +some kind of vision statement that says + + + align:start position:0% +some kind of vision statement that says +at this point these are what we think + + align:start position:0% +at this point these are what we think + + + align:start position:0% +at this point these are what we think +this the the features are going to be if + + align:start position:0% +this the the features are going to be if + + + align:start position:0% +this the the features are going to be if +at any point you make a significant + + align:start position:0% +at any point you make a significant + + + align:start position:0% +at any point you make a significant +design change that says our feature list + + align:start position:0% +design change that says our feature list + + + align:start position:0% +design change that says our feature list +is going to change our game is going to + + align:start position:0% +is going to change our game is going to + + + align:start position:0% +is going to change our game is going to +look different update that document you + + align:start position:0% +look different update that document you + + + align:start position:0% +look different update that document you +have up until the end of the semester to + + align:start position:0% +have up until the end of the semester to + + + align:start position:0% +have up until the end of the semester to +do that and whatever you turn in + + align:start position:0% +do that and whatever you turn in + + + align:start position:0% +do that and whatever you turn in +whatever that document is on the last + + align:start position:0% +whatever that document is on the last + + + align:start position:0% +whatever that document is on the last +day of class should be what game you're + + align:start position:0% +day of class should be what game you're + + + align:start position:0% +day of class should be what game you're +turning in so that the that document and + + align:start position:0% +turning in so that the that document and + + + align:start position:0% +turning in so that the that document and +the game should have the same features + + align:start position:0% +the game should have the same features + + + align:start position:0% +the game should have the same features +in there but we would like to see the + + align:start position:0% +in there but we would like to see the + + + align:start position:0% +in there but we would like to see the +the vert the any changes that happen + + align:start position:0% +the vert the any changes that happen + + + align:start position:0% +the vert the any changes that happen +between now and then we'd like to see + + align:start position:0% +between now and then we'd like to see + + + align:start position:0% +between now and then we'd like to see +how those changes happen and why I'm so + + align:start position:0% +how those changes happen and why I'm so + + + align:start position:0% +how those changes happen and why I'm so +reflect them in that on Monday turn in a + + align:start position:0% +reflect them in that on Monday turn in a + + + align:start position:0% +reflect them in that on Monday turn in a +product backlog you're going to do a + + align:start position:0% +product backlog you're going to do a + + + align:start position:0% +product backlog you're going to do a +two-minute presentation the core of your + + align:start position:0% +two-minute presentation the core of your + + + align:start position:0% +two-minute presentation the core of your +game design idea and then we're going to + + align:start position:0% +game design idea and then we're going to + + + align:start position:0% +game design idea and then we're going to +do a play test on the twenty-seventh we + + align:start position:0% +do a play test on the twenty-seventh we + + + align:start position:0% +do a play test on the twenty-seventh we +are going to have at least one possibly + + align:start position:0% +are going to have at least one possibly + + + align:start position:0% +are going to have at least one possibly +two of our clients in on that data to + + align:start position:0% +two of our clients in on that data to + + + align:start position:0% +two of our clients in on that data to +play those games jano and Jared both of + + align:start position:0% +play those games jano and Jared both of + + + align:start position:0% +play those games jano and Jared both of +them came in for the first day of class + + align:start position:0% +them came in for the first day of class + + + align:start position:0% +them came in for the first day of class +they were not in class on when the when + + align:start position:0% +they were not in class on when the when + + + align:start position:0% +they were not in class on when the when +the intro when when Pablo was on we are + + align:start position:0% +the intro when when Pablo was on we are + + + align:start position:0% +the intro when when Pablo was on we are +asking for some kind of sprint task list + + align:start position:0% +asking for some kind of sprint task list + + + align:start position:0% +asking for some kind of sprint task list +be submitted to stellar weekly what + + align:start position:0% +be submitted to stellar weekly what + + + align:start position:0% +be submitted to stellar weekly what +exactly that is is completely up to you + + align:start position:0% +exactly that is is completely up to you + + + align:start position:0% +exactly that is is completely up to you +we've given you a format that we like + + align:start position:0% +we've given you a format that we like + + + align:start position:0% +we've given you a format that we like +we've given you a method that we know + + align:start position:0% +we've given you a method that we know + + + align:start position:0% +we've given you a method that we know +works if you decide to change that + + align:start position:0% +works if you decide to change that + + + align:start position:0% +works if you decide to change that +method let us know what you decided to + + align:start position:0% +method let us know what you decided to + + + align:start position:0% +method let us know what you decided to +change it to and why but whatever you + + align:start position:0% +change it to and why but whatever you + + + align:start position:0% +change it to and why but whatever you +have at every week I should be able to + + align:start position:0% +have at every week I should be able to + + + align:start position:0% +have at every week I should be able to +go to stellar and see what tasks you + + align:start position:0% +go to stellar and see what tasks you + + + align:start position:0% +go to stellar and see what tasks you +have to do + + align:start position:0% +have to do + + + align:start position:0% +have to do +for the next week's worth of work we are + + align:start position:0% +for the next week's worth of work we are + + + align:start position:0% +for the next week's worth of work we are +asking for product backlogs that's + + align:start position:0% +asking for product backlogs that's + + + align:start position:0% +asking for product backlogs that's +actually a concrete please turn give us + + align:start position:0% +actually a concrete please turn give us + + + align:start position:0% +actually a concrete please turn give us +a product backlog the format used for + + align:start position:0% +a product backlog the format used for + + + align:start position:0% +a product backlog the format used for +the product backlog doesn't matter to us + + align:start position:0% +the product backlog doesn't matter to us + + + align:start position:0% +the product backlog doesn't matter to us +for the feature list if it's a list of + + align:start position:0% +for the feature list if it's a list of + + + align:start position:0% +for the feature list if it's a list of +user stories what matters is that all + + align:start position:0% +user stories what matters is that all + + + align:start position:0% +user stories what matters is that all +the features that you think are going to + + align:start position:0% +the features that you think are going to + + + align:start position:0% +the features that you think are going to +be in the game are listed all the + + align:start position:0% +be in the game are listed all the + + + align:start position:0% +be in the game are listed all the +features that are done are listed is + + align:start position:0% +features that are done are listed is + + + align:start position:0% +features that are done are listed is +done on and you've done some kind of + + align:start position:0% +done on and you've done some kind of + + + align:start position:0% +done on and you've done some kind of +estimation on what size those features + + align:start position:0% +estimation on what size those features + + + align:start position:0% +estimation on what size those features +are and then we're gonna have you do 22 + + align:start position:0% +are and then we're gonna have you do 22 + + + align:start position:0% +are and then we're gonna have you do 22 +minute presentations in class all these + + align:start position:0% +minute presentations in class all these + + + align:start position:0% +minute presentations in class all these +should all these dates are in stellar in + + align:start position:0% +should all these dates are in stellar in + + + align:start position:0% +should all these dates are in stellar in +the Stella Stella calendar so the next + + align:start position:0% +the Stella Stella calendar so the next + + + align:start position:0% +the Stella Stella calendar so the next +to two minute presentations are also on + + align:start position:0% +to two minute presentations are also on + + + align:start position:0% +to two minute presentations are also on +November's 12 and then November 26th any + + align:start position:0% +November's 12 and then November 26th any + + + align:start position:0% +November's 12 and then November 26th any +questions so far about any of this stuff + + align:start position:0% +questions so far about any of this stuff + + + align:start position:0% +questions so far about any of this stuff +all right so project is due on wednesday + + align:start position:0% +all right so project is due on wednesday + + + align:start position:0% +all right so project is due on wednesday +december 10th on stellar turn in all of + + align:start position:0% +december 10th on stellar turn in all of + + + align:start position:0% +december 10th on stellar turn in all of +your previous builds on your written + + align:start position:0% +your previous builds on your written + + + align:start position:0% +your previous builds on your written +post mortems your design change logs + + align:start position:0% +post mortems your design change logs + + + align:start position:0% +post mortems your design change logs +your updated document and this time + + align:start position:0% +your updated document and this time + + + align:start position:0% +your updated document and this time +we're asking you for four focus test + + align:start position:0% +we're asking you for four focus test + + + align:start position:0% +we're asking you for four focus test +reports there are in class play tests on + + align:start position:0% +reports there are in class play tests on + + + align:start position:0% +reports there are in class play tests on +the twenty-seventh the fifth and the + + align:start position:0% +the twenty-seventh the fifth and the + + + align:start position:0% +the twenty-seventh the fifth and the +24th two of those could be used for + + align:start position:0% +24th two of those could be used for + + + align:start position:0% +24th two of those could be used for +focus test reports the other two must be + + align:start position:0% +focus test reports the other two must be + + + align:start position:0% +focus test reports the other two must be +external know and then yeah we're going + + align:start position:0% +external know and then yeah we're going + + + align:start position:0% +external know and then yeah we're going +to have on postmortem presentations so a + + align:start position:0% +to have on postmortem presentations so a + + + align:start position:0% +to have on postmortem presentations so a +portion of presentations instead of five + + align:start position:0% +portion of presentations instead of five + + + align:start position:0% +portion of presentations instead of five +minutes you could have 20 minutes we're + + align:start position:0% +minutes you could have 20 minutes we're + + + align:start position:0% +minutes you could have 20 minutes we're +asking for a polished presentation of + + align:start position:0% +asking for a polished presentation of + + + align:start position:0% +asking for a polished presentation of +the work that's been gatha's that went + + align:start position:0% +the work that's been gatha's that went + + + align:start position:0% +the work that's been gatha's that went +into developing the project all the + + align:start position:0% +into developing the project all the + + + align:start position:0% +into developing the project all the +iterations that you made within it so we + + align:start position:0% +iterations that you made within it so we + + + align:start position:0% +iterations that you made within it so we +want to know about your design + + align:start position:0% +want to know about your design + + + align:start position:0% +want to know about your design +iterations in this presentation we also + + align:start position:0% +iterations in this presentation we also + + + align:start position:0% +iterations in this presentation we also +want to know those five what went right + + align:start position:0% +want to know those five what went right + + + align:start position:0% +want to know those five what went right +what went wrong what was interesting I'm + + align:start position:0% +what went wrong what was interesting I'm + + + align:start position:0% +what went wrong what was interesting I'm +in the project so that's about 10 to 15 + + align:start position:0% +in the project so that's about 10 to 15 + + + align:start position:0% +in the project so that's about 10 to 15 +minutes given on process right so and + + align:start position:0% +minutes given on process right so and + + + align:start position:0% +minutes given on process right so and +and team management too for all of your + + align:start position:0% +and team management too for all of your + + + align:start position:0% +and team management too for all of your +games someone who hasn't played the game + + align:start position:0% +games someone who hasn't played the game + + + align:start position:0% +games someone who hasn't played the game +before will play the game live on stage + + align:start position:0% +before will play the game live on stage + + + align:start position:0% +before will play the game live on stage +so that's basically a this is a one way + + align:start position:0% +so that's basically a this is a one way + + + align:start position:0% +so that's basically a this is a one way +for us to see somebody who hasn't played + + align:start position:0% +for us to see somebody who hasn't played + + + align:start position:0% +for us to see somebody who hasn't played +the game before try it out and see how + + align:start position:0% +the game before try it out and see how + + + align:start position:0% +the game before try it out and see how +it works + + align:start position:0% + + + + align:start position:0% + +it's a little bit of you and a little + + align:start position:0% +it's a little bit of you and a little + + + align:start position:0% +it's a little bit of you and a little +bit of us will do the best we can so + + align:start position:0% +bit of us will do the best we can so + + + align:start position:0% +bit of us will do the best we can so +we're asking guests to come in we're + + align:start position:0% +we're asking guests to come in we're + + + align:start position:0% +we're asking guests to come in we're +hoping our clients are going to be in + + align:start position:0% +hoping our clients are going to be in + + + align:start position:0% +hoping our clients are going to be in +we're hoping some of them might have + + align:start position:0% +we're hoping some of them might have + + + align:start position:0% +we're hoping some of them might have +already seen your games before some of + + align:start position:0% +already seen your games before some of + + + align:start position:0% +already seen your games before some of +them haven't if you have friends we + + align:start position:0% +them haven't if you have friends we + + + align:start position:0% +them haven't if you have friends we +actually some suggest you bring in + + align:start position:0% +actually some suggest you bring in + + + align:start position:0% +actually some suggest you bring in +friends to play to come in I'm in to + + align:start position:0% +friends to play to come in I'm in to + + + align:start position:0% +friends to play to come in I'm in to +watch the presentations maybe not play + + align:start position:0% +watch the presentations maybe not play + + + align:start position:0% +watch the presentations maybe not play +your game play somebody else's game but + + align:start position:0% +your game play somebody else's game but + + + align:start position:0% +your game play somebody else's game but +will we open the final presentation to + + align:start position:0% +will we open the final presentation to + + + align:start position:0% +will we open the final presentation to +the public we have a rehearsal on Monday + + align:start position:0% +the public we have a rehearsal on Monday + + + align:start position:0% +the public we have a rehearsal on Monday +the eighth and we have the final on on + + align:start position:0% +the eighth and we have the final on on + + + align:start position:0% +the eighth and we have the final on on +Wednesday the tenth so on monday the + + align:start position:0% +Wednesday the tenth so on monday the + + + align:start position:0% +Wednesday the tenth so on monday the +eighth you don't need to do the play the + + align:start position:0% +eighth you don't need to do the play the + + + align:start position:0% +eighth you don't need to do the play the +game part of the rehearsal but you do + + align:start position:0% +game part of the rehearsal but you do + + + align:start position:0% +game part of the rehearsal but you do +need to do a full dress rehearsal of the + + align:start position:0% +need to do a full dress rehearsal of the + + + align:start position:0% +need to do a full dress rehearsal of the +entire presentation and the reason why + + align:start position:0% +entire presentation and the reason why + + + align:start position:0% +entire presentation and the reason why +we're doing that is um we're going to + + align:start position:0% +we're doing that is um we're going to + + + align:start position:0% +we're doing that is um we're going to +give you feedback on that on what you + + align:start position:0% +give you feedback on that on what you + + + align:start position:0% +give you feedback on that on what you +might have missed what you would like + + align:start position:0% +might have missed what you would like + + + align:start position:0% +might have missed what you would like +you to see in the presentation and + + align:start position:0% +you to see in the presentation and + + + align:start position:0% +you to see in the presentation and +you've got a couple days to apply that + + align:start position:0% +you've got a couple days to apply that + + + align:start position:0% +you've got a couple days to apply that +feedback to your presentation to make it + + align:start position:0% +feedback to your presentation to make it + + + align:start position:0% +feedback to your presentation to make it +better basically I think that's it yeah + + align:start position:0% +better basically I think that's it yeah + + + align:start position:0% +better basically I think that's it yeah +that's all from the other day so any + + align:start position:0% +that's all from the other day so any + + + align:start position:0% +that's all from the other day so any +questions about to post mortem + + align:start position:0% +questions about to post mortem + + + align:start position:0% +questions about to post mortem +presentations previous years i'll send + + align:start position:0% +presentations previous years i'll send + + + align:start position:0% +presentations previous years i'll send +out the link to previous year so you can + + align:start position:0% +out the link to previous year so you can + + + align:start position:0% +out the link to previous year so you can +see what we what these on tend to be + + align:start position:0% +see what we what these on tend to be + + + align:start position:0% +see what we what these on tend to be +like but we've recorded them in the past + + align:start position:0% +like but we've recorded them in the past + + + align:start position:0% +like but we've recorded them in the past +so you can see what other people have + + align:start position:0% +so you can see what other people have + + + align:start position:0% +so you can see what other people have +done and that will go to the + + align:start position:0% +done and that will go to the + + + align:start position:0% +done and that will go to the +announcements page on stellar all right + + align:start position:0% +announcements page on stellar all right + + + align:start position:0% +announcements page on stellar all right +um it's 150 take a 10-minute break come + + align:start position:0% +um it's 150 take a 10-minute break come + + + align:start position:0% +um it's 150 take a 10-minute break come +back at two and work in your teams so + + align:start position:0% +back at two and work in your teams so + + + align:start position:0% +back at two and work in your teams so +the rest of class today is pretty much + + align:start position:0% +the rest of class today is pretty much + + + align:start position:0% +the rest of class today is pretty much +for you to figure out what is this + + align:start position:0% +for you to figure out what is this + + + align:start position:0% +for you to figure out what is this +project are you working on who you're + + align:start position:0% +project are you working on who you're + + + align:start position:0% +project are you working on who you're +going to be working with and things like + + align:start position:0% +going to be working with and things like + + + align:start position:0% +going to be working with and things like +that so what we're going to do is the + + align:start position:0% +that so what we're going to do is the + + + align:start position:0% +that so what we're going to do is the +typical brainstorming process we're not + + align:start position:0% +typical brainstorming process we're not + + + align:start position:0% +typical brainstorming process we're not +going to guide it so much this time just + + align:start position:0% +going to guide it so much this time just + + + align:start position:0% +going to guide it so much this time just +a quick reminder you want somebody who + + align:start position:0% +a quick reminder you want somebody who + + + align:start position:0% +a quick reminder you want somebody who +is in charge of facilitating it which + + align:start position:0% +is in charge of facilitating it which + + + align:start position:0% +is in charge of facilitating it which +means reminding everybody what is the + + align:start position:0% +means reminding everybody what is the + + + align:start position:0% +means reminding everybody what is the +problem and also calling out people who + + align:start position:0% +problem and also calling out people who + + + align:start position:0% +problem and also calling out people who +may have trouble getting the getting + + align:start position:0% +may have trouble getting the getting + + + align:start position:0% +may have trouble getting the getting +their words in front of the group like + + align:start position:0% +their words in front of the group like + + + align:start position:0% +their words in front of the group like +people who are trying to get into words + + align:start position:0% +people who are trying to get into words + + + align:start position:0% +people who are trying to get into words +edgewise so basically moderating their + + align:start position:0% +edgewise so basically moderating their + + + align:start position:0% +edgewise so basically moderating their +discussion and someone of course taking + + align:start position:0% +discussion and someone of course taking + + + align:start position:0% +discussion and someone of course taking +notes we have our sheets of our giant + + align:start position:0% +notes we have our sheets of our giant + + + align:start position:0% +notes we have our sheets of our giant +pads of paper in front you can use chalk + + align:start position:0% +pads of paper in front you can use chalk + + + align:start position:0% +pads of paper in front you can use chalk +boards for the cholera team we suggest + + align:start position:0% +boards for the cholera team we suggest + + + align:start position:0% +boards for the cholera team we suggest +splitting in half but + + align:start position:0% +splitting in half but + + + align:start position:0% +splitting in half but +well that doesn't necessarily mean that + + align:start position:0% +well that doesn't necessarily mean that + + + align:start position:0% +well that doesn't necessarily mean that +that your brainstorming team is + + align:start position:0% +that your brainstorming team is + + + align:start position:0% +that your brainstorming team is +necessarily your game team what we are + + align:start position:0% +necessarily your game team what we are + + + align:start position:0% +necessarily your game team what we are +thinking is that after brainstorming you + + align:start position:0% +thinking is that after brainstorming you + + + align:start position:0% +thinking is that after brainstorming you +will better know whether your ideas can + + align:start position:0% +will better know whether your ideas can + + + align:start position:0% +will better know whether your ideas can +be split into two projects or not right + + align:start position:0% +be split into two projects or not right + + + align:start position:0% +be split into two projects or not right +given how many cards just appeared on + + align:start position:0% +given how many cards just appeared on + + + align:start position:0% +given how many cards just appeared on +there we really really really + + align:start position:0% +there we really really really + + + align:start position:0% +there we really really really +recommended you split into groups but + + align:start position:0% +recommended you split into groups but + + + align:start position:0% +recommended you split into groups but +there may be a more organic way to split + + align:start position:0% +there may be a more organic way to split + + + align:start position:0% +there may be a more organic way to split +that because your eye your ideas may + + align:start position:0% +that because your eye your ideas may + + + align:start position:0% +that because your eye your ideas may +actually fall down on or more clearly + + align:start position:0% +actually fall down on or more clearly + + + align:start position:0% +actually fall down on or more clearly +defined lines I don't understand you + + align:start position:0% +defined lines I don't understand you + + + align:start position:0% +defined lines I don't understand you +already did some brainstorming up there + + align:start position:0% +already did some brainstorming up there + + + align:start position:0% +already did some brainstorming up there +but think what would you do with a you + + align:start position:0% +but think what would you do with a you + + + align:start position:0% +but think what would you do with a you +know half the size of of the team then + + align:start position:0% +know half the size of of the team then + + + align:start position:0% +know half the size of of the team then +after that have the discussion about you + + align:start position:0% +after that have the discussion about you + + + align:start position:0% +after that have the discussion about you +know which who is on which team by the + + align:start position:0% +know which who is on which team by the + + + align:start position:0% +know which who is on which team by the +end of class today you should know + + align:start position:0% +end of class today you should know + + + align:start position:0% +end of class today you should know +exactly who is on your team how to get + + align:start position:0% +exactly who is on your team how to get + + + align:start position:0% +exactly who is on your team how to get +in touch with each other what your email + + align:start position:0% +in touch with each other what your email + + + align:start position:0% +in touch with each other what your email +addresses are what your phone numbers + + align:start position:0% +addresses are what your phone numbers + + + align:start position:0% +addresses are what your phone numbers +are or instant messaging handles or + + align:start position:0% +are or instant messaging handles or + + + align:start position:0% +are or instant messaging handles or +whatever and make sure that that you + + align:start position:0% +whatever and make sure that that you + + + align:start position:0% +whatever and make sure that that you +figured that that out let's see one + + align:start position:0% +figured that that out let's see one + + + align:start position:0% +figured that that out let's see one +thing that I want to tack on to Rick's + + align:start position:0% +thing that I want to tack on to Rick's + + + align:start position:0% +thing that I want to tack on to Rick's +presentation earlier about the + + align:start position:0% +presentation earlier about the + + + align:start position:0% +presentation earlier about the +expectations for the post more than we + + align:start position:0% +expectations for the post more than we + + + align:start position:0% +expectations for the post more than we +brought up the person who has not played + + align:start position:0% +brought up the person who has not played + + + align:start position:0% +brought up the person who has not played +your game before coming up and actually + + align:start position:0% +your game before coming up and actually + + + align:start position:0% +your game before coming up and actually +playing your game and I know some of you + + align:start position:0% +playing your game and I know some of you + + + align:start position:0% +playing your game and I know some of you +might be worried about that do be aware + + align:start position:0% +might be worried about that do be aware + + + align:start position:0% +might be worried about that do be aware +that however that well or badly that + + align:start position:0% +that however that well or badly that + + + align:start position:0% +that however that well or badly that +person performs it no matter how how + + align:start position:0% +person performs it no matter how how + + + align:start position:0% +person performs it no matter how how +much do you like the game or like + + align:start position:0% +much do you like the game or like + + + align:start position:0% +much do you like the game or like +completely misunderstand what what your + + align:start position:0% +completely misunderstand what what your + + + align:start position:0% +completely misunderstand what what your +games about that is going to be at best + + align:start position:0% +games about that is going to be at best + + + align:start position:0% +games about that is going to be at best +one-point-five percent of your total + + align:start position:0% +one-point-five percent of your total + + + align:start position:0% +one-point-five percent of your total +total semester grade that's not really + + align:start position:0% +total semester grade that's not really + + + align:start position:0% +total semester grade that's not really +significant it's not going to really + + align:start position:0% +significant it's not going to really + + + align:start position:0% +significant it's not going to really +swing anything so don't worry about it + + align:start position:0% +swing anything so don't worry about it + + + align:start position:0% +swing anything so don't worry about it +but we are actually good using those + + align:start position:0% +but we are actually good using those + + + align:start position:0% +but we are actually good using those +sessions to gauge usability right you + + align:start position:0% +sessions to gauge usability right you + + + align:start position:0% +sessions to gauge usability right you +know to what extent have you actually + + align:start position:0% +know to what extent have you actually + + + align:start position:0% +know to what extent have you actually +designed the game to sort of make your + + align:start position:0% +designed the game to sort of make your + + + align:start position:0% +designed the game to sort of make your +game easy for people who've never seen + + align:start position:0% +game easy for people who've never seen + + + align:start position:0% +game easy for people who've never seen +your game to get into it this is this + + align:start position:0% +your game to get into it this is this + + + align:start position:0% +your game to get into it this is this +these are the things that we want you to + + align:start position:0% +these are the things that we want you to + + + align:start position:0% +these are the things that we want you to +be iterating on these are the things + + align:start position:0% +be iterating on these are the things + + + align:start position:0% +be iterating on these are the things +that we want you to be catching for and + + align:start position:0% +that we want you to be catching for and + + + align:start position:0% +that we want you to be catching for and +without having like a real life + + align:start position:0% +without having like a real life + + + align:start position:0% +without having like a real life +high-stakes there is going to be a + + align:start position:0% +high-stakes there is going to be a + + + align:start position:0% +high-stakes there is going to be a +person who hasn't played your game in + + align:start position:0% +person who hasn't played your game in + + + align:start position:0% +person who hasn't played your game in +front playing your game you know you may + + align:start position:0% +front playing your game you know you may + + + align:start position:0% +front playing your game you know you may +not take it so seriously so we want you + + align:start position:0% +not take it so seriously so we want you + + + align:start position:0% +not take it so seriously so we want you +to be taking usability really really + + align:start position:0% +to be taking usability really really + + + align:start position:0% +to be taking usability really really +seriously that's why Rick said the scope + + align:start position:0% +seriously that's why Rick said the scope + + + align:start position:0% +seriously that's why Rick said the scope +of the game doesn't necessarily need to + + align:start position:0% +of the game doesn't necessarily need to + + + align:start position:0% +of the game doesn't necessarily need to +be + + align:start position:0% +be + + + align:start position:0% +be +all that different from the past but the + + align:start position:0% +all that different from the past but the + + + align:start position:0% +all that different from the past but the +amount of polish the amount of time + + align:start position:0% +amount of polish the amount of time + + + align:start position:0% +amount of polish the amount of time +amount of time that you've taught + + align:start position:0% +amount of time that you've taught + + + align:start position:0% +amount of time that you've taught +through your UI you know it's what you + + align:start position:0% +through your UI you know it's what you + + + align:start position:0% +through your UI you know it's what you +should be spending all your time on + + align:start position:0% +should be spending all your time on + + + align:start position:0% +should be spending all your time on +finally we're going to go a little bit + + align:start position:0% +finally we're going to go a little bit + + + align:start position:0% +finally we're going to go a little bit +more into games for learning and the in + + align:start position:0% +more into games for learning and the in + + + align:start position:0% +more into games for learning and the in +the next couple of in the next week but + + align:start position:0% +the next couple of in the next week but + + + align:start position:0% +the next couple of in the next week but +one thing that we want you to be + + align:start position:0% +one thing that we want you to be + + + align:start position:0% +one thing that we want you to be +thinking about while you're + + align:start position:0% +thinking about while you're + + + align:start position:0% +thinking about while you're +brainstorming is of course what is the + + align:start position:0% +brainstorming is of course what is the + + + align:start position:0% +brainstorming is of course what is the +player doing now you're trying to teach + + align:start position:0% +player doing now you're trying to teach + + + align:start position:0% +player doing now you're trying to teach +something to someone you're trying to + + align:start position:0% +something to someone you're trying to + + + align:start position:0% +something to someone you're trying to +get them in a situation where they're + + align:start position:0% +get them in a situation where they're + + + align:start position:0% +get them in a situation where they're +learning about a certain concept it is + + align:start position:0% +learning about a certain concept it is + + + align:start position:0% +learning about a certain concept it is +ideal if the thing that you are trying + + align:start position:0% +ideal if the thing that you are trying + + + align:start position:0% +ideal if the thing that you are trying +to teach them is actually the thing that + + align:start position:0% +to teach them is actually the thing that + + + align:start position:0% +to teach them is actually the thing that +they are doing now there's a way that's + + align:start position:0% +they are doing now there's a way that's + + + align:start position:0% +they are doing now there's a way that's +a couple of other ways actually um can + + align:start position:0% +a couple of other ways actually um can + + + align:start position:0% +a couple of other ways actually um can +we break Constantine's that's like yep + + align:start position:0% +we break Constantine's that's like yep + + + align:start position:0% +we break Constantine's that's like yep +sorry the jungles there to there are a + + align:start position:0% +sorry the jungles there to there are a + + + align:start position:0% +sorry the jungles there to there are a +couple of other things that you probably + + align:start position:0% +couple of other things that you probably + + + align:start position:0% +couple of other things that you probably +are already considering putting into + + align:start position:0% +are already considering putting into + + + align:start position:0% +are already considering putting into +your game ah you know things like what + + align:start position:0% +your game ah you know things like what + + + align:start position:0% +your game ah you know things like what +is the theme and I notice you know the + + align:start position:0% +is the theme and I notice you know the + + + align:start position:0% +is the theme and I notice you know the +brainstorming for the cholera already + + align:start position:0% +brainstorming for the cholera already + + + align:start position:0% +brainstorming for the cholera already +started talking about the exact story + + align:start position:0% +started talking about the exact story + + + align:start position:0% +started talking about the exact story +line right so that's the theme of the + + align:start position:0% +line right so that's the theme of the + + + align:start position:0% +line right so that's the theme of the +game actually match not just the topic + + align:start position:0% +game actually match not just the topic + + + align:start position:0% +game actually match not just the topic +that you're trying to teach but also the + + align:start position:0% +that you're trying to teach but also the + + + align:start position:0% +that you're trying to teach but also the +mechanics that you are designed that + + align:start position:0% +mechanics that you are designed that + + + align:start position:0% +mechanics that you are designed that +you're designing for it you want to be + + align:start position:0% +you're designing for it you want to be + + + align:start position:0% +you're designing for it you want to be +thinking and a couple of you have + + align:start position:0% +thinking and a couple of you have + + + align:start position:0% +thinking and a couple of you have +already been asking about things like + + align:start position:0% +already been asking about things like + + + align:start position:0% +already been asking about things like +who's going to be playing your game + + align:start position:0% +who's going to be playing your game + + + align:start position:0% +who's going to be playing your game +what's a demographic I'll also be + + align:start position:0% +what's a demographic I'll also be + + + align:start position:0% +what's a demographic I'll also be +thinking what situation are they likely + + align:start position:0% +thinking what situation are they likely + + + align:start position:0% +thinking what situation are they likely +to be playing in are they likely to be + + align:start position:0% +to be playing in are they likely to be + + + align:start position:0% +to be playing in are they likely to be +playing it on their own at home is that + + align:start position:0% +playing it on their own at home is that + + + align:start position:0% +playing it on their own at home is that +what you want to design for and you can + + align:start position:0% +what you want to design for and you can + + + align:start position:0% +what you want to design for and you can +specify this you can say that this is a + + align:start position:0% +specify this you can say that this is a + + + align:start position:0% +specify this you can say that this is a +game that's meant to be played you know + + align:start position:0% +game that's meant to be played you know + + + align:start position:0% +game that's meant to be played you know +by an individual person with an + + align:start position:0% +by an individual person with an + + + align:start position:0% +by an individual person with an +individual computer on your own time or + + align:start position:0% +individual computer on your own time or + + + align:start position:0% +individual computer on your own time or +this is meant to be played like in a + + align:start position:0% +this is meant to be played like in a + + + align:start position:0% +this is meant to be played like in a +group with a where you know like the + + align:start position:0% +group with a where you know like the + + + align:start position:0% +group with a where you know like the +snack game was played in a group right + + align:start position:0% +snack game was played in a group right + + + align:start position:0% +snack game was played in a group right +in front of in front of everybody else + + align:start position:0% +in front of in front of everybody else + + + align:start position:0% +in front of in front of everybody else +of course the things like you know that + + align:start position:0% +of course the things like you know that + + + align:start position:0% +of course the things like you know that +that by the way falls into the frame it + + align:start position:0% +that by the way falls into the frame it + + + align:start position:0% +that by the way falls into the frame it +the framing I idea what what is the + + align:start position:0% +the framing I idea what what is the + + + align:start position:0% +the framing I idea what what is the +context in which someone's actually + + align:start position:0% +context in which someone's actually + + + align:start position:0% +context in which someone's actually +going to be playing game to what extent + + align:start position:0% +going to be playing game to what extent + + + align:start position:0% +going to be playing game to what extent +have they played games like what you are + + align:start position:0% +have they played games like what you are + + + align:start position:0% +have they played games like what you are +describing you know if you are making + + align:start position:0% +describing you know if you are making + + + align:start position:0% +describing you know if you are making +something like a hard core strategy game + + align:start position:0% +something like a hard core strategy game + + + align:start position:0% +something like a hard core strategy game +to what extent do people need to be + + align:start position:0% +to what extent do people need to be + + + align:start position:0% +to what extent do people need to be +familiar with strategy games in order to + + align:start position:0% +familiar with strategy games in order to + + + align:start position:0% +familiar with strategy games in order to +be able to play a game or you know do + + align:start position:0% +be able to play a game or you know do + + + align:start position:0% +be able to play a game or you know do +they just need to be familiar with + + align:start position:0% +they just need to be familiar with + + + align:start position:0% +they just need to be familiar with +things like Facebook games for instance + + align:start position:0% +things like Facebook games for instance + + + align:start position:0% +things like Facebook games for instance +or do you really want to make a game + + align:start position:0% +or do you really want to make a game + + + align:start position:0% +or do you really want to make a game +that that doesn't assume much play + + align:start position:0% +that that doesn't assume much play + + + align:start position:0% +that that doesn't assume much play +literacy at all you want to be looking + + align:start position:0% +literacy at all you want to be looking + + + align:start position:0% +literacy at all you want to be looking +of course at the data and that means all + + align:start position:0% +of course at the data and that means all + + + align:start position:0% +of course at the data and that means all +of the material that we provided you as + + align:start position:0% +of the material that we provided you as + + + align:start position:0% +of the material that we provided you as +well as any information that you're + + align:start position:0% +well as any information that you're + + + align:start position:0% +well as any information that you're +looking at in in Google searches or + + align:start position:0% +looking at in in Google searches or + + + align:start position:0% +looking at in in Google searches or +academic research or information that + + align:start position:0% +academic research or information that + + + align:start position:0% +academic research or information that +you're getting from the domain experts + + align:start position:0% +you're getting from the domain experts + + + align:start position:0% +you're getting from the domain experts +from either the human that humanitarian + + align:start position:0% +from either the human that humanitarian + + + align:start position:0% +from either the human that humanitarian +response lab or all the climate or the + + align:start position:0% +response lab or all the climate or the + + + align:start position:0% +response lab or all the climate or the +client the climate Center is it right + + align:start position:0% +client the climate Center is it right + + + align:start position:0% +client the climate Center is it right +claimant yeah so make sure that you know + + align:start position:0% +claimant yeah so make sure that you know + + + align:start position:0% +claimant yeah so make sure that you know +yeah we are representing that as fairly + + align:start position:0% +yeah we are representing that as fairly + + + align:start position:0% +yeah we are representing that as fairly +as you can because this is a game you + + align:start position:0% +as you can because this is a game you + + + align:start position:0% +as you can because this is a game you +know you do have liberties to at which + + align:start position:0% +know you do have liberties to at which + + + align:start position:0% +know you do have liberties to at which +point you can sort of abstract out those + + align:start position:0% +point you can sort of abstract out those + + + align:start position:0% +point you can sort of abstract out those +numbers you know maybe are not + + align:start position:0% +numbers you know maybe are not + + + align:start position:0% +numbers you know maybe are not +mathematically very very precise because + + align:start position:0% +mathematically very very precise because + + + align:start position:0% +mathematically very very precise because +you're trying to get a sudden feel of + + align:start position:0% +you're trying to get a sudden feel of + + + align:start position:0% +you're trying to get a sudden feel of +the game and that of course goes into + + align:start position:0% +the game and that of course goes into + + + align:start position:0% +the game and that of course goes into +the aesthetics part not just the + + align:start position:0% +the aesthetics part not just the + + + align:start position:0% +the aesthetics part not just the +graphical aesthetics but the way how + + align:start position:0% +graphical aesthetics but the way how + + + align:start position:0% +graphical aesthetics but the way how +your game feels if you're trying to + + align:start position:0% +your game feels if you're trying to + + + align:start position:0% +your game feels if you're trying to +represent you know a really really tense + + align:start position:0% +represent you know a really really tense + + + align:start position:0% +represent you know a really really tense +situation on the ground and the way how + + align:start position:0% +situation on the ground and the way how + + + align:start position:0% +situation on the ground and the way how +your data model makes it resolve makes + + align:start position:0% +your data model makes it resolve makes + + + align:start position:0% +your data model makes it resolve makes +it feel like your game is really + + align:start position:0% +it feel like your game is really + + + align:start position:0% +it feel like your game is really +clinical and very very easy to deal with + + align:start position:0% +clinical and very very easy to deal with + + + align:start position:0% +clinical and very very easy to deal with +the situation as long as you know as you + + align:start position:0% +the situation as long as you know as you + + + align:start position:0% +the situation as long as you know as you +know the tried and true formula then + + align:start position:0% +know the tried and true formula then + + + align:start position:0% +know the tried and true formula then +you're not accurately representing the + + align:start position:0% +you're not accurately representing the + + + align:start position:0% +you're not accurately representing the +situation even though you might be + + align:start position:0% +situation even though you might be + + + align:start position:0% +situation even though you might be +accurately using data so make sure that + + align:start position:0% +accurately using data so make sure that + + + align:start position:0% +accurately using data so make sure that +you're balancing that aesthetic feel + + align:start position:0% +you're balancing that aesthetic feel + + + align:start position:0% +you're balancing that aesthetic feel +together with the content you know + + align:start position:0% +together with the content you know + + + align:start position:0% +together with the content you know +whatever real-world facts that you're + + align:start position:0% +whatever real-world facts that you're + + + align:start position:0% +whatever real-world facts that you're +putting into your game because these + + align:start position:0% +putting into your game because these + + + align:start position:0% +putting into your game because these +games are all really about real-world + + align:start position:0% +games are all really about real-world + + + align:start position:0% +games are all really about real-world +things you might want to make sure that + + align:start position:0% +things you might want to make sure that + + + align:start position:0% +things you might want to make sure that +your fiction and narrative is something + + align:start position:0% +your fiction and narrative is something + + + align:start position:0% +your fiction and narrative is something +that's not too fantastical or at least + + align:start position:0% +that's not too fantastical or at least + + + align:start position:0% +that's not too fantastical or at least +if it there is a fantasy element of it + + align:start position:0% +if it there is a fantasy element of it + + + align:start position:0% +if it there is a fantasy element of it +it is the part that has leased to do + + align:start position:0% +it is the part that has leased to do + + + align:start position:0% +it is the part that has leased to do +with the believability of the things + + align:start position:0% +with the believability of the things + + + align:start position:0% +with the believability of the things +that you're trying to do communicate you + + align:start position:0% +that you're trying to do communicate you + + + align:start position:0% +that you're trying to do communicate you +know you can say that there is a village + + align:start position:0% +know you can say that there is a village + + + align:start position:0% +know you can say that there is a village +or a city that's dealing with a cholera + + align:start position:0% +or a city that's dealing with a cholera + + + align:start position:0% +or a city that's dealing with a cholera +epidemic + + align:start position:0% +epidemic + + + align:start position:0% +epidemic +something and that's not a real city + + align:start position:0% +something and that's not a real city + + + align:start position:0% +something and that's not a real city +anywhere on the map of the world but you + + align:start position:0% +anywhere on the map of the world but you + + + align:start position:0% +anywhere on the map of the world but you +can look at that city and imagine this + + align:start position:0% +can look at that city and imagine this + + + align:start position:0% +can look at that city and imagine this +could be a real city somewhere in in the + + align:start position:0% +could be a real city somewhere in in the + + + align:start position:0% +could be a real city somewhere in in the +world you could you know go as far and + + align:start position:0% +world you could you know go as far and + + + align:start position:0% +world you could you know go as far and +say okay this is like a you know Dark + + align:start position:0% +say okay this is like a you know Dark + + + align:start position:0% +say okay this is like a you know Dark +Ages or something like like that because + + align:start position:0% +Ages or something like like that because + + + align:start position:0% +Ages or something like like that because +the disease has certainly been around + + align:start position:0% +the disease has certainly been around + + + align:start position:0% +the disease has certainly been around +for a long time but you you know you + + align:start position:0% +for a long time but you you know you + + + align:start position:0% +for a long time but you you know you +want to be able to keep reminding people + + align:start position:0% +want to be able to keep reminding people + + + align:start position:0% +want to be able to keep reminding people +that this is a real thing you know if + + align:start position:0% +that this is a real thing you know if + + + align:start position:0% +that this is a real thing you know if +you say that this is a science-fiction + + align:start position:0% +you say that this is a science-fiction + + + align:start position:0% +you say that this is a science-fiction +thing where you're on a different planet + + align:start position:0% +thing where you're on a different planet + + + align:start position:0% +thing where you're on a different planet +and it's a completely different kind of + + align:start position:0% +and it's a completely different kind of + + + align:start position:0% +and it's a completely different kind of +bug that behaves exactly the same as + + align:start position:0% +bug that behaves exactly the same as + + + align:start position:0% +bug that behaves exactly the same as +Colorado and us I'm trying to feel that + + align:start position:0% +Colorado and us I'm trying to feel that + + + align:start position:0% +Colorado and us I'm trying to feel that +maybe the fiction that you're creating + + align:start position:0% +maybe the fiction that you're creating + + + align:start position:0% +maybe the fiction that you're creating +video game is undercutting what you're + + align:start position:0% +video game is undercutting what you're + + + align:start position:0% +video game is undercutting what you're +trying to get this game to do we just + + align:start position:0% +trying to get this game to do we just + + + align:start position:0% +trying to get this game to do we just +actually teach people about something + + align:start position:0% +actually teach people about something + + + align:start position:0% +actually teach people about something +real so jump in on the fiction narrative + + align:start position:0% +real so jump in on the fiction narrative + + + align:start position:0% +real so jump in on the fiction narrative +so things to think about your games are + + align:start position:0% +so things to think about your games are + + + align:start position:0% +so things to think about your games are +being played by specific culture people + + align:start position:0% +being played by specific culture people + + + align:start position:0% +being played by specific culture people +with a specific cultural background + + align:start position:0% +with a specific cultural background + + + align:start position:0% +with a specific cultural background +especially the cholera game will will + + align:start position:0% +especially the cholera game will will + + + align:start position:0% +especially the cholera game will will +likely be played by I believe it was + + align:start position:0% +likely be played by I believe it was + + + align:start position:0% +likely be played by I believe it was +it's Ghana so students who are in Ghana + + align:start position:0% +it's Ghana so students who are in Ghana + + + align:start position:0% +it's Ghana so students who are in Ghana +so what kind of culture do they have + + align:start position:0% +so what kind of culture do they have + + + align:start position:0% +so what kind of culture do they have +you're gonna have to research that and + + align:start position:0% +you're gonna have to research that and + + + align:start position:0% +you're gonna have to research that and +figure that out for those games to + + align:start position:0% +figure that out for those games to + + + align:start position:0% +figure that out for those games to +figure out what kinds of common + + align:start position:0% +figure out what kinds of common + + + align:start position:0% +figure out what kinds of common +backgrounds might they have that you + + align:start position:0% +backgrounds might they have that you + + + align:start position:0% +backgrounds might they have that you +could talk about for the heat waves game + + align:start position:0% +could talk about for the heat waves game + + + align:start position:0% +could talk about for the heat waves game +that actually has more of a focus on Red + + align:start position:0% +that actually has more of a focus on Red + + + align:start position:0% +that actually has more of a focus on Red +Cross volunteers and university students + + align:start position:0% +Cross volunteers and university students + + + align:start position:0% +Cross volunteers and university students +you can specify we understand that + + align:start position:0% +you can specify we understand that + + + align:start position:0% +you can specify we understand that +people who are playing this game are + + align:start position:0% +people who are playing this game are + + + align:start position:0% +people who are playing this game are +likely going to be from from Europe and + + align:start position:0% +likely going to be from from Europe and + + + align:start position:0% +likely going to be from from Europe and +they're likely going to have this kind + + align:start position:0% +they're likely going to have this kind + + + align:start position:0% +they're likely going to have this kind +of background like when you're creating + + align:start position:0% +of background like when you're creating + + + align:start position:0% +of background like when you're creating +your high level game design document + + align:start position:0% +your high level game design document + + + align:start position:0% +your high level game design document +come up with what you think you're what + + align:start position:0% +come up with what you think you're what + + + align:start position:0% +come up with what you think you're what +you imagine your target audience to be + + align:start position:0% +you imagine your target audience to be + + + align:start position:0% +you imagine your target audience to be +so you have this some kind of cultural + + align:start position:0% +so you have this some kind of cultural + + + align:start position:0% +so you have this some kind of cultural +background to go to to use and so that + + align:start position:0% +background to go to to use and so that + + + align:start position:0% +background to go to to use and so that +you're not again you're choosing fiction + + align:start position:0% +you're not again you're choosing fiction + + + align:start position:0% +you're not again you're choosing fiction +that is going to be supportive and + + align:start position:0% +that is going to be supportive and + + + align:start position:0% +that is going to be supportive and +helpful and not fiction that might be + + align:start position:0% +helpful and not fiction that might be + + + align:start position:0% +helpful and not fiction that might be +not known or might undermine the idea + + align:start position:0% +not known or might undermine the idea + + + align:start position:0% +not known or might undermine the idea +one thing to keep in mind with Finn with + + align:start position:0% +one thing to keep in mind with Finn with + + + align:start position:0% +one thing to keep in mind with Finn with +the fantastical studies have found that + + align:start position:0% +the fantastical studies have found that + + + align:start position:0% +the fantastical studies have found that +some games that have when it comes to + + align:start position:0% +some games that have when it comes to + + + align:start position:0% +some games that have when it comes to +pandemics and outbreaks using the zombie + + align:start position:0% +pandemics and outbreaks using the zombie + + + align:start position:0% +pandemics and outbreaks using the zombie +fiction actually can work sometimes + + align:start position:0% +fiction actually can work sometimes + + + align:start position:0% +fiction actually can work sometimes +there is something to be said about + + align:start position:0% +there is something to be said about + + + align:start position:0% +there is something to be said about +using a common fiction that people know + + align:start position:0% +using a common fiction that people know + + + align:start position:0% +using a common fiction that people know +that people can say all right I + + align:start position:0% +that people can say all right I + + + align:start position:0% +that people can say all right I +understand I understand how zombie work + + align:start position:0% +understand I understand how zombie work + + + align:start position:0% +understand I understand how zombie work +hossam be on panel epics work because + + align:start position:0% +hossam be on panel epics work because + + + align:start position:0% +hossam be on panel epics work because +I've seen all these films about it + + align:start position:0% +I've seen all these films about it + + + align:start position:0% +I've seen all these films about it +whereas if he just told me it was a + + align:start position:0% +whereas if he just told me it was a + + + align:start position:0% +whereas if he just told me it was a +disease + + align:start position:0% +disease + + + align:start position:0% +disease +might not have seen enough films that + + align:start position:0% +might not have seen enough films that + + + align:start position:0% +might not have seen enough films that +had anything about how that how a + + align:start position:0% +had anything about how that how a + + + align:start position:0% +had anything about how that how a +disease is actually I'm spread so really + + align:start position:0% +disease is actually I'm spread so really + + + align:start position:0% +disease is actually I'm spread so really +think about what is your problem what + + align:start position:0% +think about what is your problem what + + + align:start position:0% +think about what is your problem what +fictions might be useful what narratives + + align:start position:0% +fictions might be useful what narratives + + + align:start position:0% +fictions might be useful what narratives +might be useful for you for the problem + + align:start position:0% +might be useful for you for the problem + + + align:start position:0% +might be useful for you for the problem +is right you use fiction to keep the + + align:start position:0% +is right you use fiction to keep the + + + align:start position:0% +is right you use fiction to keep the +topics relatable and you know if that + + align:start position:0% +topics relatable and you know if that + + + align:start position:0% +topics relatable and you know if that +means drawing on things on public land + + align:start position:0% +means drawing on things on public land + + + align:start position:0% +means drawing on things on public land +popular culture you know that's great + + align:start position:0% +popular culture you know that's great + + + align:start position:0% +popular culture you know that's great +that's a tool in your hand don't use + + align:start position:0% +that's a tool in your hand don't use + + + align:start position:0% +that's a tool in your hand don't use +fiction as a way to paper over design + + align:start position:0% +fiction as a way to paper over design + + + align:start position:0% +fiction as a way to paper over design +problems which I've often seen you know + + align:start position:0% +problems which I've often seen you know + + + align:start position:0% +problems which I've often seen you know +if you set this game in space then we + + align:start position:0% +if you set this game in space then we + + + align:start position:0% +if you set this game in space then we +can sort of like skip over all reality + + align:start position:0% +can sort of like skip over all reality + + + align:start position:0% +can sort of like skip over all reality +something like that when you're + + align:start position:0% +something like that when you're + + + align:start position:0% +something like that when you're +brainstorming make sure you know what + + align:start position:0% +brainstorming make sure you know what + + + align:start position:0% +brainstorming make sure you know what +you're brainstorming about are you + + align:start position:0% +you're brainstorming about are you + + + align:start position:0% +you're brainstorming about are you +brainstorming mechanics so about what + + align:start position:0% +brainstorming mechanics so about what + + + align:start position:0% +brainstorming mechanics so about what +people are going to be doing or you're + + align:start position:0% +people are going to be doing or you're + + + align:start position:0% +people are going to be doing or you're +brainstorming you know what the fiction + + align:start position:0% +brainstorming you know what the fiction + + + align:start position:0% +brainstorming you know what the fiction +is going to be I would say do a separate + + align:start position:0% +is going to be I would say do a separate + + + align:start position:0% +is going to be I would say do a separate +brainstorming session for each one of + + align:start position:0% +brainstorming session for each one of + + + align:start position:0% +brainstorming session for each one of +these things maybe you know just spend + + align:start position:0% +these things maybe you know just spend + + + align:start position:0% +these things maybe you know just spend +ten ten minutes you don't have to bring + + align:start position:0% +ten ten minutes you don't have to bring + + + align:start position:0% +ten ten minutes you don't have to bring +some every single thing that we're + + align:start position:0% +some every single thing that we're + + + align:start position:0% +some every single thing that we're +showing you here you could brainstorm + + align:start position:0% +showing you here you could brainstorm + + + align:start position:0% +showing you here you could brainstorm +what is the aim and impact that you want + + align:start position:0% +what is the aim and impact that you want + + + align:start position:0% +what is the aim and impact that you want +to achieve in this game how are you + + align:start position:0% +to achieve in this game how are you + + + align:start position:0% +to achieve in this game how are you +going to all of you even on the same + + align:start position:0% +going to all of you even on the same + + + align:start position:0% +going to all of you even on the same +page about what you want your game the + + align:start position:0% +page about what you want your game the + + + align:start position:0% +page about what you want your game the +kind of change you want to see in a + + align:start position:0% +kind of change you want to see in a + + + align:start position:0% +kind of change you want to see in a +world right and that's that's going to + + align:start position:0% +world right and that's that's going to + + + align:start position:0% +world right and that's that's going to +be your purpose that's that that is + + align:start position:0% +be your purpose that's that that is + + + align:start position:0% +be your purpose that's that that is +going what do you all understand what + + align:start position:0% +going what do you all understand what + + + align:start position:0% +going what do you all understand what +this thing is a lot of it has been + + align:start position:0% +this thing is a lot of it has been + + + align:start position:0% +this thing is a lot of it has been +defined for you but I'm not guaranteeing + + align:start position:0% +defined for you but I'm not guaranteeing + + + align:start position:0% +defined for you but I'm not guaranteeing +that everybody on your team necessarily + + align:start position:0% +that everybody on your team necessarily + + + align:start position:0% +that everybody on your team necessarily +shares the same idea so brainstorming + + align:start position:0% +shares the same idea so brainstorming + + + align:start position:0% +shares the same idea so brainstorming +process might be able to get that out + + align:start position:0% +process might be able to get that out + + + align:start position:0% +process might be able to get that out +and at some point of time within the + + align:start position:0% +and at some point of time within the + + + align:start position:0% +and at some point of time within the +next couple of weeks you should have a + + align:start position:0% +next couple of weeks you should have a + + + align:start position:0% +next couple of weeks you should have a +pretty good idea or you should have had + + align:start position:0% +pretty good idea or you should have had + + + align:start position:0% +pretty good idea or you should have had +a chance to at least talk with your team + + align:start position:0% +a chance to at least talk with your team + + + align:start position:0% +a chance to at least talk with your team +about every one of these elements this + + align:start position:0% +about every one of these elements this + + + align:start position:0% +about every one of these elements this +is a research framework that's been put + + align:start position:0% +is a research framework that's been put + + + align:start position:0% +is a research framework that's been put +together by one of our colleagues + + align:start position:0% +together by one of our colleagues + + + align:start position:0% +together by one of our colleagues +Constantine mikich I think we can put a + + align:start position:0% +Constantine mikich I think we can put a + + + align:start position:0% +Constantine mikich I think we can put a +link to it yeah almost worse the slides + + align:start position:0% +link to it yeah almost worse the slides + + + align:start position:0% +link to it yeah almost worse the slides +in this particular arm slide stellar I + + align:start position:0% +in this particular arm slide stellar I + + + align:start position:0% +in this particular arm slide stellar I +will get back to we might get back to + + align:start position:0% +will get back to we might get back to + + + align:start position:0% +will get back to we might get back to +elements of this later in a week but + + align:start position:0% +elements of this later in a week but + + + align:start position:0% +elements of this later in a week but +right now this is just basically + + align:start position:0% +right now this is just basically + + + align:start position:0% +right now this is just basically +something to help guide your + + align:start position:0% +something to help guide your + + + align:start position:0% +something to help guide your +brainstorming yeah aesthetics were + + align:start position:0% +brainstorming yeah aesthetics were + + + align:start position:0% +brainstorming yeah aesthetics were +recovering on Wednesday on fiction we're + + align:start position:0% +recovering on Wednesday on fiction we're + + + align:start position:0% +recovering on Wednesday on fiction we're +covering in a couple weeks finally one + + align:start position:0% +covering in a couple weeks finally one + + + align:start position:0% +covering in a couple weeks finally one +reminder about brainstorming if you do + + align:start position:0% +reminder about brainstorming if you do + + + align:start position:0% +reminder about brainstorming if you do +have if you're brainstorming session + + align:start position:0% +have if you're brainstorming session + + + align:start position:0% +have if you're brainstorming session +runs more than ten ten + + align:start position:0% +runs more than ten ten + + + align:start position:0% +runs more than ten ten +minutes you want to flip your + + align:start position:0% +minutes you want to flip your + + + align:start position:0% +minutes you want to flip your +Secretary's around so that somebody else + + align:start position:0% +Secretary's around so that somebody else + + + align:start position:0% +Secretary's around so that somebody else +is taking notes and let the person who's + + align:start position:0% +is taking notes and let the person who's + + + align:start position:0% +is taking notes and let the person who's +been frantically writing things down + + align:start position:0% +been frantically writing things down + + + align:start position:0% +been frantically writing things down +actually get their ideas into okay we're + + align:start position:0% +actually get their ideas into okay we're + + + align:start position:0% +actually get their ideas into okay we're +not going to time that for you that's + + align:start position:0% +not going to time that for you that's + + + align:start position:0% +not going to time that for you that's +going to be something for you and once + + align:start position:0% +going to be something for you and once + + + align:start position:0% +going to be something for you and once +they've got their team's email video + + align:start position:0% +they've got their team's email video + + + align:start position:0% +they've got their team's email video +game buzzes that's put your your vision + + align:start position:0% +game buzzes that's put your your vision + + + align:start position:0% +game buzzes that's put your your vision +statement should have all your team your + + align:start position:0% +statement should have all your team your + + + align:start position:0% +statement should have all your team your +team and all your member names in it and + + align:start position:0% +team and all your member names in it and + + + align:start position:0% +team and all your member names in it and +that's due on stellar on the date that + + align:start position:0% +that's due on stellar on the date that + + + align:start position:0% +that's due on stellar on the date that +it says so put all your names in + + align:start position:0% +it says so put all your names in + + + align:start position:0% +it says so put all your names in +Division statement yeah rest of class is + + align:start position:0% +Division statement yeah rest of class is + + + align:start position:0% +Division statement yeah rest of class is +yours \ No newline at end of file